IMPROVED, LOW VISCOSITY, SHELF STABLE, ENERGY-ACTIIVATED COMPOSITIONS, EQUIPMENT, SYTEMS AND METHODS FOR PRODUCING SAME

- H.B. Fuller Company

The present invention provides low viscosity energy-activated room temperature polymer compositions, equipment, systems and methods for handling, activating and dispensing the thermodynamically unstable, high solids, activatable liquid compositions.

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Description
PRIORITY CLAIM

This application claims priority to U.S. App. Ser. No. 61/285,816, filed Dec. 11, 2009, U.S. App. Ser No. 61/294,679, filed Jan. 13, 2010, and U.S. App. Ser. No. 61/309,181, filed Mar. 1, 2010, each of which is hereby incorporated by reference in its entirety.

BACKGROUND OF INVENTION

1. Field of Invention

The present invention provides low viscosity energy-activated room temperature polymer compositions, equipment, systems and methods for handling, activating and dispensing the thermodynamically unstable, high solids, activatable liquid compositions.

2. Description of Related Art

Hot melt adhesives are routinely used in various applications where a stable surface-to-surface bond must be formed. Further, hot melt adhesives are used in securing a variety of both similar and dissimilar materials (e.g., cellulosic substrates such as wood, corrugated paper, cardboard, paper, carton stock, and other substrate materials such as plastics, metals, fabric and other textiles, leather etc.) together in a mating relationship. These adhesives are especially useful in applications where it is desirable to have the adhesive solidify rapidly after being dispensed. There are several drawbacks with the use of conventional hot melt dispensing systems including handling solids, high energy consumption, polymer decomposition, expensive equipment, safety concerns and the like.

Stumphauzer, WO/2001/53389 A1, describes a heat-activated thermoplastic material for forming an adhesive formed from an admixture of a thermoplastic resin (typically polyvinyl chloride) in a liquid carrier (typically a phthalate-based plasticizer). The admixture is a liquid slurry at room temperature that undergoes a change in which the slurry becomes pasty upon heating to a fusion temperature and liquefies upon further heating to form a pumpable molten liquid. The molten liquid hardens as it cools to form an adhesive.

Stumphauzer et al., U.S. Pat. Nos. 7,221,859, 7,285,583, 7,501,468, and 7,772,312, each of which is hereby incorporated by reference in its entirety, disclose a multiple component polymer compositions that are pumpable at room temperature and form a molten hot melt material when heated above about 300° F. and mixed and equipment for activating and dispensing such composition. The molten hot melt material can be dispensed to form a solid adhesive material upon cooling.

Jorgenson et. al., WO/2009/108685 A1, which is hereby incorporated by reference in its entirety, discloses methods and compositions including a foamed adhesive that utilizes relatively small amounts of blowing agents such as water at temperatures heated above about 140° F. and equipment capable of processing these compositions. Upon dispensing of the heated polymeric adhesive, the vapor from the heated water aids in the performance of the foamed solid adhesive. Subsequent research has shown that optimization of this foam to create uniformly dispersed, stable, fine cells sometimes requires the use of various complex processing additives.

The compositions and equipment described by Stumphauzer et. al. and Jorgenson et. al. overcame many of the problems facing conventional adhesives, sealant and gasket systems by eliminating the unpleasant odors and smoke associated with remote kettles, the high energy costs, the safety hazards and the thermal degradation of the adhesive compositions. Such compositions need only to be energy-activated at the point of dispensing, which thus confers many of the advantages of cold glue applications, but has the advantage over cold glue systems of much more rapid speed due to the high solids, the ability to use materials that would normally degrade under extended and repeated exposure to high temperatures and cleaner, faster applications at the elevated temperatures of the point of dispensing.

Jorgenson et. al. further teach that a combination of the micro-structure and the resultant macro-structure can affect the stability, viscosity, rheological properties, and the like, of the liquid emulsions, dispersion and/or suspensions below 140° F. Jorgenson et al. teach that lower viscosity materials can be obtained using a relatively complex emulsion polymerized ethyl vinyl acetate product and ground poly-alkylene polymers mixed at room temperature.

Although the technology described by Stumphauzer et al. and Jorgenson et al. provides significant advances over the prior art, improvements can still be made to address practical process and equipment limitations in the industrial setting associated with waste and product separation in the low pressure delivery systems, separation in the high pressure delivery systems, frequent problems with shut-down and start-ups. Compositions such as disclosed by Stumphauzer et al. and Jorgenson et al. tend to be thermodynamically unstable, meaning that pressure, shear forces or polymer hysteresis, chemical induced differentials on the composition tend to cause the various components of the composition to separate (e.g., the liquid carrier can separate from the polymer solids). While the prior art gives pumpable, liquid, polymer compositions that are reasonably stable to separation, they suffer from being high viscosity requiring complicated equipment solutions to satisfactorily transfer and dispense the compositions. Alternatively, pumpable, liquid polymer compositions that are low viscosities can be prepared but have limited resistance to separation of the polymer and the liquid phases which creates consistency problems in storage, separation in hoses and/or in a heat break and inconsistent processing of the pumpable, liquid polymer compositions.

BRIEF SUMMARY OF THE INVENTION

In view of the foregoing, the present invention provides compositions, processes, equipment and methods that provide substantial advantages over the prior art in the form of less waste, improved shelf life stability, improved system stability, consistent start-up processing, no pack outs and ultimate performance advantages.

The compositions according to the invention are low viscosity, shelf life stable products at room temperature that can be activated to form substantially homogeneous molten material capable of bonding two components when dispensed and cooled as a cellular or solid non-cellular polymeric substantially non-exuding material. The compositions according to the invention comprise:

    • solid particles comprising one or more polymers (sometimes hereinafter referred to as the “first component”), which are emulsified, dispersed and/or suspended at temperatures substantially below the melting point or below the temperature where the solid particles are soluble with a second liquid component;
    • a second liquid component comprising one or more polymers processed in a liquid carrier at temperatures exceeding 100° F. and substantially below the melting point or below the temperature where the liquid plasticizes the bulk (about 75% or greater by weight) of the polymers creating a high viscosity intermediate component, which can be used to form a lower solids, lower viscosity liquid emulsion, dispersion and/or suspension; and
    • a liquid carrier that is selected based upon the ability of the first and/or second component to substantially resist absorption of the liquid carrier at the storage and pre-processing temperatures and is absorbed when the material is activated to form a substantially homogeneous molten material capable of bonding two components when dispensed and cooled as a cellular or solid non-cellular polymeric substantially non-exuding solid.

Unless otherwise expressly stated, the term “room temperature” is hereby defined as being 72±5° F. and at other ambient temperatures from about 32° F. to 140° F., preferably 50° F. to 120° F., most preferably 60° F. to 110° F.

The present invention is also directed towards a delivery system for handling and delivering low viscosity, shelf life stable, room temperature compositions that can be activated to form substantially homogeneous molten material capable of bonding two components when dispensed and cooled as a cellular or solid non-cellular polymeric substantially non-exuding material in a stable, homogeneous room temperature emulsion, dispersion and/or suspension from a low pressure side to a high pressure side. The low pressure side comprises a shipping container, which is capable of being evacuated via gravity feed or with vacuum created by a hydraulic pump, and a reservoir capable of:

    • delivering greater than 10 pounds per hour, preferably greater than 20 pounds per hour and most preferably greater than 40 pounds per hour via gravity feed or vacuum assist, and
    • delivering first in-first out with minimal polymer separation from the liquid carrier.

The high pressure side of the delivery system comprises a pump capable of delivering low viscosity, shelf life stable, room temperature compositions that can be activated to form substantially homogeneous molten material capable of bonding two components when dispensed and cooled as a cellular or solid non-cellular polymeric substantially non-exuding material that is connected to:

    • a heat break device designed to insure maintenance free start ups after temporary interruptions; and/or
    • a heat break in combination with a “friction loss” component and timed shut down protocol, which continuously and gradually reduces the pressure on the composition inducing back-flowing heat-activatable material to solidify at a point in the system where it can be easily reheated, thereby preventing irreversible plugging of the unheated portion of the system as pressure differentials are relieved; and/or
    • a three component “chemical heat break check” which induces back-flowing heat-activatable material to solidify at a point in the system where it can be easily reheated, thereby preventing irreversible plugging of the unheated portion of the system as pressure differentials are relieved.

The foregoing and other features of the invention are hereinafter more fully described and particularly pointed out in the claims, the following description setting forth in detail certain illustrative embodiments of the invention, these being indicative, however, of but a few of the various ways in which the principles of the present invention may be employed.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic representation of a delivery system according to an embodiment of the invention.

FIG. 2a is a perspective view of an embodiment of a reservoir and associated conduits for a delivery system according to the invention.

FIG. 2b is a cross-sectional view taken through the middle of a reservoir design that did not perform as desired.

FIG. 2c is a cross-sectional view taken through the middle of a reservoir design that did perform as desired.

FIG. 3 is an assembled view of a heat break according to an embodiment of the invention.

FIG. 4 is an exploded view of the heat break shown in FIG. 3.

FIG. 5 is a section view taken longitudinally through the center of the heat break shown in FIG. 4.

FIG. 6 schematically illustrates a controlled plug in the section view of FIG. 5.

 DETAILED DESCRIPTION OF THE INVENTION

As noted above, compositions according to the invention are low viscosity, shelf life stable products at room temperature that can be activated to form substantially homogeneous molten material capable of bonding two components when dispensed and cooled as a cellular or solid non-cellular polymeric substantially non-exuding material. The compositions according to the invention comprise:

    • solid particles comprising one or more polymers (sometimes hereinafter referred to as the “first component”), which are emulsified, dispersed and/or suspended at temperatures substantially below the melting point or below the temperature where the solid particles are soluble with a second liquid component;
    • a second liquid component comprising one or more polymers processed in a liquid carrier at temperatures exceeding 100° F. and substantially below the melting point or below the temperature where the bulk of the polymers in the liquid carrier become soluble creating a high viscosity, homogeneous liquid component; thereby creating a lower solids, lower viscosity liquid emulsion, dispersion and/or suspension; and
    • a liquid carrier that is selected based upon the ability of the first and/or second component to substantially resist absorption of the liquid carrier at the storage and pre-processing temperatures and is absorbed when the material is activated to form a substantially homogeneous molten material capable of bonding two components when dispensed and cooled as a cellular or solid non-cellular polymeric substantially non-exuding solid.

A. The First Component Monomers/Starters

The first component of the compositions according to the invention comprises solid particles of one or more polymers that can be derived from polymerizing any combination of ethylene, propylene, butylene, higher α-olefins or isomers thereof, styrene and its isomers, isoprene, butadiene, higher α-dienes or isomers thereof, norbornene, dicyclopentadiene, acrylic acid and its derivatives thereof, methacrylic acid and its derivatives thereof, olefinically unsaturated dicarboxylic acid and its derivatives thereof, acrylonitrile, vinyl chloride, vinylidene chloride, vinyl ester, vinyl ethers, vinyl silanes and the like. Additional polymers can be constructed with combinations of starter molecules with reactive hydrogen such as water, sorbitol, glycerol, sucrose, multifunctional amines, and the like, together with or, optionally the monomers by themselves or in combination with themselves such as oxides, for example, ethylene oxide, propylene oxide, tetrahydrofuran, and the like, various multifunctional acids or anhydrides, for example terephthalic acid, phthalic anhydride, adipic acid, succinic anhydride and the like, glycols such as ethylene glycol, propylene glycols, butlyene glycol, and the like, and/or various multi-function amines, for example, urea, ethylene diamine, hexamethylene diamine, and the like. These chemicals in various combinations result in polyethers, polyesters, polyamides, polyether amines which can result in high performance finished products. Highly specialized polymers could include silicones formulated for adhesion similar to those used in room temperature vulcanization (RTV's) processes where the silanols condense at high temperatures. Natural polymers such as proteins and their derivatives, starches and their derivatives, cellulosics and their derivatives, fats and oils their derivatives, for example natural and synthetic rubbers, lignins, terpene resins, rosin esters, derivatives of wood, gum, and tall oil rosin can be used in any combination with the above fossil fuel polymers that permits them to be emulsified, dispersed or suspended as solids in the second liquid component at room temperature up to temperatures substantially below the melting point or below the temperature where the solid particles are soluble with the second liquid component.

Polymerization Conditions

The first component may include combinations of polymers that can range from homo-polymers to multi-feedstock polymers, copolymerized, step-polymerized, or any combination of the above in the gas or liquid phase. The processes can include addition, condensation, free radical, anion or cation, gas, liquid or solid state, and the like, catalyzed polymerizations. The choice of polymer process and compositions can lead to polymers with random, block, branched, tipped or any combination of these leading to various distributions along the chain or chains. In addition, polymers that have grafted monomers on the polymer chain can lead to further enhancements. Judicious choice of these parameters ultimately lead to various macrostructures that could include standard structure polymeric materials capable of being ground, higher or lower crystallinity polymers, spherical or jagged particles, core and shell particles, and the like.

Particle Size

The polymers used in the first component may be obtained as virgin, recycled or scrap material in the form of pellets, sheets, tubes, rods, films, formed materials, bottles, or the like. However, in order to achieve the proper plastisol viscosity, stability, pumpability and over-all delivery characteristics, such materials should be reduced to an average particle size (diameter) of less than about 5000 microns, preferably less than about 1,500 microns and most preferably below about 1000 microns. Thus, it may be advantageous to purchase the material in the form of a powder or other granular forms.

The first component in the invention is selected based upon the ability of the first and second component to:

    • substantially resist absorption of the liquid carrier at the storage and pre-processing temperatures;
    • the ability of the first and second component to irreversibly absorb substantially a majority of the liquid carrier when the composition is subjected to elevated processing temperatures where the materials are fused, and;
    • the ability of the first component to prevent exudation of the liquid carrier from the fused solid material that is formed when the composition is dispensed and cooled from the elevated processing and activation temperature.

The levels of the actual polymer or combination of polymers used as the first component is a function of the beginning viscosity of the second component which is dependent on the actual polymer or combination of polymers used as part of the second liquid component and any other ancillary additives. Depending on the composition and characteristics of the first component and the viscosity of the second component, the first component ranges from 2.5% to 45%, preferably 5% to 40%, most preferably 10% to 35%.

The ultimate choice of polymer(s) for the first component will be a function of many criteria discussed above in addition to the stability to oxidation and radiation such as light, micro-waves, costs, degree of transparency to radiation, the tack time which is that time when the energized polymer is no longer sticky, process hygiene, set time which is the time the application is workable, bond time described below, open time which is the time the application can me moved without damaging the finished product characteristics, stiffness, hardness, density which is a function of both the polymer and blowing agent, volume, flexibility, conformability, resilience, creep, elongation, strength modulus elongation, chemical resistance, temperature resistance, environmental resistance and compressibility and the like.

B. The Second Component

Key factors influencing the selection of polymers and liquid carriers include the impact on the viscosity and shelf life stability of the composition in its pumpable, pre-activated state. Lowering the viscosity of the composition while maintaining the shelf life stability in its pre-activated room temperature state is highly desirable as it allows the material to be transferred by gravity, pneumatics, peristaltic pumps, gear pumps, piston pumps and the like and stored in a variety of containers for extended periods of time. It has surprisingly been found that high levels of polymers can be emulsified, dispersed and/or suspended in the liquid carrier at elevated temperatures below the melting point of the polymers or below the temperature where the liquid is substantially soluble in the polymer to produce a second liquid component with relatively high solids and when combined with the first component simultaneously creates a low viscosity and shelf life stabile composition in the pre-activated state.

The actual polymer or combination of polymers used as part of the second liquid component is selected from the first component based upon the majority of the polymers ability to substantially resist absorption of the liquid carrier at the storage and pre-processing temperatures. Advantageously, the performance of the final composition is enhanced if the majority of the polymers in the second liquid,

    • preferably absorbs substantially a majority of the liquid carrier when the composition is subjected to elevated processing temperatures where the materials are fused, and;
    • most preferably, prevents exudation of the liquid carrier from the fused solid material that is formed when the composition is dispensed and cooled from the elevated processing and activation temperatures.

Mixing the polymer in the liquid carrier at temperatures above or nearing the melting point or temperatures where the polymer is highly plasticized creates higher viscosity liquids, paste or solid when cooled to room temperature; thereby, creating a stable, pumpable, material with unacceptably high viscosity. As anticipated, this behavior is highly dependent on the solids used in the process, i.e., higher solids give higher viscosity second component liquids.

Unexpectedly, it was discovered that a low viscosity, high solids second component could be produced adding and mixing a high level of the solids to a carrier heated greater than 100° F. and more than 25° F. below, preferably more than 50° F. below, most preferably more than 75° F. below the melting point or temperatures where substantial plasticization for a majority of the polymer added to the heated carrier occurs, where a majority is greater than 60%, preferably greater than 80%, and most preferably greater than 90% of the polymer composition.

Generally speaking, higher concentrations of the polymers can be used in the second component if the melting point, solubility and plasticization characteristics of the polymers are balanced against the conditions and temperatures at which the second component is processed. The percentage of solids in the second component ranges up to 60%, preferably up to 50%, most preferably up to 40%. The percentage of the second component of the final composition can be up to 95%, preferably up to 80%, most preferably up to 70%.

While not being bound to any particular theory, the compositions created are thought to be liquid carrier stabilized particles. This is not expected since the carrier would not be classified as a classical stabilizer such as a surfactant, reactive grafted polymer, compatibilizer, or the like. In addition, the low viscosities should actually increase since it is well know that any absorption or loss of the liquid phase creates higher viscosity end products. In another aspect of the theory, it is speculated that the liquid carrier stabilized particles must have other qualities of smoother, more pliable surfaces that have a slip agent qualities in the liquid phase resulting in the low viscosity and shelf life stable products.

C. The Liquid Carrier

The liquid carrier must be a flowable material at room temperature. The liquid carrier enables the composition to be pumpable at room temperatures up to 110° F., preferably up to 120° F. and most preferably up to about 140° F. and contributes to the quality and unique properties of the fused matrix on cooling. The liquid carrier may be chosen by optimizing several factors including cost, reactivity at storage conditions and dispensing temperatures, compatibility with the first component and second component at various temperatures, volatility, safety considerations, regulatory approvals, and the like. Suitable materials for use as the liquid carrier include low volatility solvents, tall oils, liquid plasticizers, aliphatic hydrocarbons, hydrocarbon esters, vegetable oils and their derivatives, glycerol and its derivatives, glycols and their derivatives, polyols and alkoxylates. Such liquids must be substantially stable with the first and second components, processing aids and optional liquid or solid components at temperatures less than about 85° F., preferably less than about 100° F. and most preferably less than about 140° F.

The choice and level of liquid carrier and any material that is liquid or soluble at room temperature is a key determinant in obtaining a low viscosity finished product. The levels in the end use product range up to 65%, preferably up to 55%, most preferably up to 45%.

Liquid natural products such as vegetable oils and their derivatives and by products, fats, carbohydrates and their derivatives or other natural materials derived from renewable sources are preferred for the second component. The most preferred choices for the second component are soybean oil and its derivatives (e.g., epoxidized soybean oil), biodiesel, glycerol and the like.

D. End Use Products

The compositions according to the invention are low viscosity, shelf life stable products at room temperature that can be activated to form substantially homogeneous molten material capable of bonding two components when dispensed and cooled as a cellular or solid non-cellular polymeric substantially non-exuding material.

The compositions according to the invention comprise:

    • solid particles comprising one or more polymers (sometimes hereinafter referred to as the “first component”), which are emulsified, dispersed and/or suspended at temperatures substantially below the melting point or below the temperature where the solid particles are soluble with a second liquid component;
    • a second liquid component comprising one or more polymers processed in a liquid carrier at temperatures exceeding 100° F. and substantially below the melting point or below the temperature where the liquid plasticizes the bulk (about 75% or greater by weight) of the polymers creating a high viscosity intermediate component, which can be used to form a lower solids, lower viscosity liquid emulsion, dispersion and/or suspension; and
    • a liquid carrier that is selected based upon the ability of the first and/or second component to substantially resist absorption of the liquid carrier at the storage and pre-processing temperatures and is absorbed when the material is activated to form a substantially homogeneous molten material capable of bonding two components when dispensed and cooled as a cellular or solid non-cellular polymeric substantially non-exuding solid.

The compositions according to the invention, before being energy-activated, can be characterized as liquid emulsions, dispersions and/or suspensions in which the first component and any other optional additional solids or liquids, are emulsified, dispersed or suspended as distinct or composite particles in the second component. Alternatively, the optional liquid or solid components can be soluble in the second component. For example, solid tackifiers and soybean oil can be combined in various ratios to create a higher proportion of liquid carrier and lower viscosity liquid polymer compositions.

These optional components can also include thermoset polymers, natural by-products such as lignin derivatives, intractable animal and plant proteins, initiators, curing agents, cure accelerators, catalysts, crosslinking agents, tackifiers, plasticizers, dyes, flame retardants, coupling agents, pigments, impact modifiers, flow control agents, foaming agents, fillers, glass treated and untreated microspheres, inorganic and organic polymer microparticles, other particles including electrically conductive particles, thermally conductive particles, synthetic, plant and animal fibers, antistatic agents, antioxidants, and UV absorbers, biocides, rheology modifiers, film formers, tackifying resin dispersions, soluble tackfiers and their derivatives.

Thus, the low viscosity intermediate composition is an emulsion, dispersion or suspension or combination of the above that can be used advantageously to produce a low viscosity, pumpable, pre-activated polymer composition.

Ethylvinyl acetate polymers are advantageously used as the first component to absorb the second component during processing. A fused homogenous blend comprising such polymers exhibits excellent bonding to a broad range of substrates upon cooling to a temperature below about 140° F.

In another embodiment of the invention, combinations of high levels of low surface energy, unreactive homopolymers that are not normally considered adhesives by themselves, such as polypropylene or polyethylene homopolymers, are used in combination with ethylvinylacetate polymers to create room temperature-pumpable compositions that do not need activators such as sebacic acid. The amount of polypropylene preferably comprises up to about 40% by weight of the total composition, and more preferably less than about 30% by weight and most preferably less than about 20% by weight of the total composition. The amount of polyethylene preferably comprises up to about 20% by weight of the total composition, and more preferably less than about 15% by weight and most preferably less than about 10% by weight of the total composition. It is possible to produce room temperature-pumpable compositions according to the invention that have viscosities less than about 15,000 cps, preferably less than about 10,000 cps and most preferably less than 8,000 cps.

Thus, compositions according to the invention can exist in four different states, depending upon conditions:

    • (i) a liquid emulsion, dispersion or suspension when stored at temperatures from about 32° F. up to about 140° F.;
    • (ii) a substantially homogeneous, fused molten blend when first heated above about 140° F. (and more preferably above about 212° F.) and mixed;
    • (iii) a substantially homogeneous, fused molten blend capable of being applied directly or expanded with the aid of a blowing agent when dispensed above about 140° F. (and more preferably above about 212° F.); and
    • (iv) a thermoplastic cellular or solid non-cellular polymeric solid material, which may be capable of bonding one or more substrates when the dispensed substantially homogeneous, fused molten blend cools to a temperature below about 140° F.

E. Method of Bonding Two Substrates Together

In yet another embodiment of the invention, the composition is activated in a reactor and dispensed between two substrates. Upon cooling, the material forms an adhesive bond between the two substrates.

F. Products

The invention includes cases or cartons comprising one or more flaps that have been sealed using the compositions and methods of the invention, and adhesives, sealants, coatings and gaskets formed using the compositions and methods of the invention.

G. Delivery System

It is well known that chemical and/or physical means can be used to influence the stability of emulsions, dispersions or suspension. As noted above and in the examples, the present invention provides a product that has greatly improved static stability as exemplified by the viscosity and centrifuge tests. In spite of this improved stability, it has been found that shear and pressure differentials can still lead to minor inconsistencies in the composition of the low viscosity, shelf life stable products as they transition through the various components of the system. The present invention thus also provides a delivery system for dispensing such a product that ensures that the:

    • material can be continuously and reliably delivered to the dispensing apparatus with minimal waste,
    • destabilizing differentials are avoided on the material that could lead to the separation of the components thereby requiring unwanted maintenance, and
    • activated material does not flow backwards in the delivery system, thereby solidifying within the portions unactivated material in the intended cool portions of the system creating the need for unwanted maintenance.

A delivery system 10 according to the invention is schematically illustrated in FIG. 1. The system 10 includes a low pressure side 20, which comprises a shipping container 30 and a reservoir 40, and a high pressure side 50, which comprises a pump 60, an insulator 80, a heat exchanger 90 and a dispenser 100. In the preferred embodiment, the insulator 80 is part of a heat break 110. The system 10 also preferably comprises a “T” 70 and a friction loss coil 120, which is in fluid communication between the high pressure side 50 and the low pressure side 20.

1. Low Pressure Side

The reservoir 40 is disposed between the shipping container 30 and the components of high pressure side 50 of the system 10. The shipping container can be a small container (e.g., a bag-in-box, a drum, a tote or other container) or a larger bulk container. The reservoir 40 is adapted to receive, store and supply unheated material to the pump 60 with minimal waste and product deterioration. The reservoir 40 can be formed of any material that does not react with or degrade the product to be dispensed. In one embodiment, the reservoir 40 is formed of polyvinyl chloride (PVC). In a more preferred embodiment, the reservoir 40 is made of polyalkylene materials. Preferably, the reservoir 40 comprises a vessel to which a vacuum or gas, which could be air or an inert material, could be alternately applied to substantially empty the shipping container 30 while simultaneously delivering an uninterrupted flow of pumpable composition through a conduit to the pump 60. The volume of the reservoir and its associated conduits is sufficient to allow an operator to replace an emptied shipping container with a shipping container containing a new supply of material without introducing debris, entraining gas in the material or destabilizing the material.

This reservoir insures consistent delivery and allows the user to easily manage the replacement of the shipping container without disruption. It was unexpectedly discovered that this low pressure reservoir system could not be constructed in the simple, cost effective manner such as is conventional for other liquid handling systems.

It was desirable to have a gravity feed and/or vacuum assist provided by the high pressure pump delivering material to the activation portion of the delivery system. A five gallon bag-in-box system with a one inch port was selected as the preferred shipping vessel to evaluate low pressure reservoir configurations. To insure consistent performance over time for pumpable materials with viscosities ranging from 5,000 to 60,000 cps, preferably 6,000 to 30,000 cps, and most preferably from 7.500 to 20,000 cps the reservoir must be able to:

    • deliver greater than 10 pounds per hour, preferably greater than 20 pounds per hour and most preferably greater than 40 pounds per hour via gravity feed or vacuum assist, and
    • be capable of delivering first in-first out with minimal polymer separation from the liquid carrier.

It was discovered that any barrier or dead spot in the reservoir system would lead to areas where “dry” material would lodge at the barrier or dead spot creating an inhomogeneous material to continuously build up eventually leading to failure of the system reservoir capability. The term “dry” as used herein describes a material in which the liquid has separated sufficiently from the solid particles to become an unflowable, inhomogeneous mass. A barrier leading to the formation of a “dry” material could be a ledge or a sharp bend representing a corner.

FIG. 2a is a perspective view of an embodiment of a reservoir 40 and associated conduits for a delivery system 10 according to the invention. The shipping container 30 (not shown) is adapted to couple to a conduit 410 via a coupling 420. Product flows from the shipping container through the conduit 410 and into the reservoir 40. Intermediate the coupling 420 and the reservoir 40, the conduit 410 includes a port 430, which as described in greater detail below, receives material flowing from the high pressure side 50 to the low pressure side 20 through a friction loss coil 120. Product from the shipping container flows into the reservoir 40 and exits the reservoir 40 through a conduit 440, which supplies the material to the pump 60 (not shown).

In order to monitor the amount of product in the reservoir 40, product exiting the reservoir can optionally also be directed to flow through a conduit 450, which includes a portion that rises vertically substantially parallel to the reservoir and includes a sight glass portion 460 that allows for visual determination of the amount of product in the reservoir 40. An electronically controlled vent valve 470 can be provided at the end of the conduit 450 and above the reservoir 40 to permit air to escape and relieve pressure within the low pressure side. A low level sensor 480 can be installed in conduit 450. And, an empty cutoff sensor 490 can be installed in conduit 440. It will be appreciated that the configuration of the reservoir 40 and its associated conduits can be varied, as required, to meet the needs of the particular application.

FIG. 2b shows a cross-sectional view of a reservoir 40′, which includes sharp corners 500 and horizontal flat areas 510. A reservoir 40′ having this configuration did not function as desired. It was found that a one inch right angle PVC joint resulted in the formation of a “dry” mass, which restricted the flow to the point that the desired delivery rate could not be met.

FIG. 2c shows a cross-sectional view of a reservoir 40 that does function as desired. The reservoir 40 shown in FIG. 2c does not include any sharp (e.g., 90°) angles. Surprisingly, the elimination of sharp angles and flat (horizontal) areas appears to be very important. Instead, the reservoir 40 shown in FIG. 2c includes non-horizontal ramp portions 520 and angles 530 greater than 90°.

A reservoir 40 according to the present invention thus preferably comprises:

    • a container having greater than 1 liter, preferably greater than 3 liters and most preferably greater than 5 liter capacity,
    • no restriction in the primary flow path of greater than 0.75 inch, preferably less than 1.0 inch, most preferably less than 1.5 inch,
    • no barriers greater than 0.5″ in depth, preferably greater than 0.25″, most preferably greater than 0.1″,
    • no turns in the primary flow pattern where the obtuse angle measured on the outside of the respective turn formed by two tangential lines on the outside of the turn has a combined measurement of one inch and the measured obtuse angle is not less than 120 degrees,
    • the ability to hold vacuum or accept pressures up to 120 PSIG, and
    • a mechanical or automated vent capable of sufficiently releasing trapped gas as the material flows into the reservoir.

Optionally, the reservoir component further comprises:

    • a sight glass or tubing capable of allowing for a measurement device that has greater than 1.00 times the diameter of the diameter of the connector to the shipping container, and
    • other connections capable of returning material from the high pressure side of system such as an inlet from a friction loss coil and the like.

Variations can be made in the arrangement of the parts in the storage container and reservoir without departing from the scope of the invention so long as the low pressure side of the system performs the following functions: substantially empties the shipping container of a material; substantially maintains the thermodynamically unstable, high solids, activatable liquid compositions in the same condition and performance as the material in the shipping container; and allows for continuous, uninterrupted operation of the system for supplying the material to the high pressure side.

2. High Pressure Side

Developing a high pressure delivery system that is stable during routine running, shut down and start up poses unexpected challenges associated with the movement of the liquid in the pump 60, connecting hoses or lines and in the heat break 110 as the pressure is applied or released and/or as temperature is applied or released. It has been surprisingly discovered that obstacles faced in the low pressure system are also present in the high pressure system as pressure differentials, restrictions, barriers and turns can induce the liquid carrier to separate from the polymer. Failure of the equipment to properly manage this flow results in the system slowly starting up or not starting up at all, can lead to weak and/or inconsistent bead dispensing, and/or production disruptions.

a. Hydraulic Pump System

A key element of the high pressure delivery system is a hydraulic pumping system 60 that does not lead to discontinuous pressure differentials as the system experiences planned or unplanned disruptions or is shut down over an extended period of time. With reference to FIG. 1, it has been found that separation of the polymer from the liquid carrier can be eliminated in the hydraulic pump 60 by connecting the high pressure output of the hydraulic pump to a “T” 70 having two parallel channels:

    • a primary channel 130 designed to deliver the liquid to the components required to activate the composition and dispense the composition when the dispenser is opened for dispensing, and
    • a secondary channel 140, which includes the “friction loss component” 120 that constantly returns a small quantity of liquid back to the low pressure reservoir 40 or the input side of the pump 60.

The system according to the invention preferably comprises a tubular friction loss coil 120, which is in fluid communication between a friction loss outlet (i.e., the port in the “T” 70 to which the secondary channel 140 is connected) on the high pressure side of the system and an inlet in the reservoir on the low pressure side of the system. The term “coil” is used only to describe a preferred embodiment of the invention. It will be appreciated that the tubular friction loss conduit need not actually be coiled in order to perform its desired function, which is to gradually reduce pressure on the material as it passes from the high pressure side of the system to the low pressure side of the system.

The term “friction loss” refers to that portion of pressure lost by fluids while moving through a pipe, hose or other limited space. The friction loss coil according to the invention ensures that the pump can remain on and can cycle when material is not being dispensed or it slowly diminishes the pressure when the pump is stopped. In both instances, material will flow through the friction loss coil and back into the reservoir 40. The pressure at the pump will remain high, but due to “friction loss” the pressure at the reservoir will be low. Friction loss causes a gradual diminishment of pressure on the material, rather than an abrupt pressure differential in the pumping system. This prevents the material from separating in the system.

The length and diameter of friction loss coil is sufficient to gradually reduce the pressure on the material from the high pressure side which is >300 psi hydraulic pressure to the low pressure side which is equal to or less than atmospheric pressure. The length, diameter and pressure differentials of the friction loss coil will be selected in view of the viscosity, flow characteristics, thermodynamic stability, inherent particle sizes, and the like of the material to insure that the pumps and flow patterns do not stop flowing or seize up creating unwanted pressure differentials.

The “friction loss” component must:

    • continuously deliver less than 5%, preferably less than 2.5% and most preferably less than 1% of the weight capacity of the hydraulic pump, and
    • gradually reduce the pressure from the hydraulic head pressure to less than 50 psig, preferably less than 25 psig and most preferably less than 10 psig at the return to reservoir or input of the pump
      b. Heat Break System

The heat break prevents thermal energy from migrating from a heat exchanger 90, which heats and activates the product to be dispensed through the dispenser 100, into unheated portions of the system. This is critical to insure that the material is not prematurely activated. Normal dispensing conditions allow for an equilibrium to be established where the cold incoming liquid material meets the heated material from the heat exchanger 90 and no deleterious plugs or “dry” material are formed causing the dispensing unit 100 to stop or lose pressure. However, relief of the pressure used to pump the material to the heat break and through the heat exchanger and dispenser generally leads to the heated material reversing direction towards the pump, where it can cool thereby creating a plug or form “dry” material in the heat break 110, hose or both. This can lead to an irreversible situation as the heat exchanger 90 can no longer provide enough energy to cause the plug to be substantially liquefied to flow or the pressure in the system is not powerful enough to push the plug through the hose, heat break or both.

Complex systems involving check valves, dump valves, timing sequences and the like have been used to overcome this key deficiency. However, separation can occur when conventional check valves are used, because the liquid phase, for example oils, will leak through to the low pressure side of small openings such as a check valves, constrictions, or poor O-ring seals, fittings, and the like. Due to this phenomenon associated with thermodynamically unstable, high solids liquids, separation of the material can occur leaving dry material on one side of the pressure differential and liquid on the other side. This creates undesirable consequences which include plugs, creates poor performance, causes disruption in production, and the like.

The heat break systems described by Stumphauzer et. al. and Jorgenson et. al. function according to their intended purpose of suppressing heat from activating the glue in the hydraulic hose as long as the adhesive is dispensed on substantially uninterrupted basis in the high pressure system. However, the present invention provides improvements, which are particularly advantageous in manufacturing environments where frequent disruptions and shut downs occur. In order to provide the most efficient dispensing system the heat break design must be optimized bringing the following benefits:

    • it should be able to re-activate cured material after short term interruptions, short and long term shut downs, and unplanned disruptions in the dispensing process,
    • it should prevent thermal energy from traveling from the heat exchanger/dispenser to other areas in the system where thermal energy inappropriately activates the liquid, and
    • it should be designed to insure that the carrier and polymer do not separate in the device to form a dry plug, which would will prevent flow of material to the dispenser 100.

With reference to FIG. 3, it was discovered that a heat break 110 comprising the following components and/or features overcomes these problems, and performs well during short term disruptions:

    • a first insulator 80 made of a non-conductive material, most preferably constructed from PEEK, and
    • a heat dissipater 150 made of a conductive material, most preferably aluminum, wherein
    • a channel is provided between the first insulator 80 and the heat dissipater 150 greater than 0.100 inch, preferably greater than 0.125 inch and most preferably greater than 0.200 inch, and optionally
    • a second insulator 160, preferably made of PEEK,

The first insulator 80 is coupled between the heat exchanger 90 and the heat dissipater 150. The first insulator 80 prevents heat from migrating from the heat exchanger 90 toward the unheated portion of the delivery system connection 130 and beyond. The heat dissipater 150, in this particular embodiment includes a channel through which material supplied from the cold end 170 can be supplied. The outer surface of the heat dissipater 150 preferably includes a plurality of heat sink fins 210 shown in FIGS. 5 and 6, which allow heat to escape to the atmosphere. Heat can reach the first heat dissipater 150 when heated material flows back into the heat break 110 after it has been heated in the heat exchanger 90. Material flowing back from the heat exchanger 90 enters the hot end 180 of the insulator 80 and then makes contact with the heat dissipater 150. The second insulator 160 helps isolate the heat break 110 from the remaining cold portions of the delivery system 10.

While not wishing to be held to any particular theory, the heat dissipater 150 functions to cool the activated material in a region adjacent to the heat exchanger/dispenser 90/100 (these units can be combined) to form a short “chemical plug” that is capable of being reversibly pushed back into the heat exchanger/dispenser 90/100 via pressure supplied by the pump 60. This chemical plug serves as pseudo check valve stopping the pressurized, activated material in the heat exchanger/dispenser 90/100 from pushing back into regions of the delivery system that are designed to be at or near room temperature. Eliminating irreversible plugs enables the dispensing process to be temporarily disrupted and have the dispensing process restarted with no manual maintenance of the system. The chemical plug forms between the heat dissipater which has a mix of activated and heated material and the heat break, which has cool unactivated material in a substantial portion of the heat break. The design of the region where it is desirable to form this chemical plug in the heat dissipater 150 and heat break consists of:

    • no barriers greater than 0.100″ in depth, preferably greater than 0.050″, most preferably greater than 0.025″, and
    • no constrictions in the forward flow pattern before the glue is subjected to melting temperatures in the heat dissipater.

The subject of this invention solved the problems associated with short term disruption as long as the pressure was maintained. However, a complete disruption of the temperature and a pressure caused other unanticipated pressure differentials associated with activated glue cooling down, creating a vacuum in the heat exchanger/dispenser unit. This unanticipated pressure differential led to the liquid carrier being separated from the polymer which then required maintenance to satisfactorily dispense the activated liquid on restarting the system.

c. Friction Loss/Thermal Break Process

Thus, to avoid this problem, in a preferred embodiment of the invention, it is desirable to combine the hydraulic pump system disclosed above, or a comparable hydraulic pumping system capable releasing the pressure in a controlled manner, with the heat break in a process where the temperature is first shut down followed by shutting down of the pressure of greater than 5 minutes later, preferably greater than 15 minutes later and most preferably greater than 30 minutes later.

d. Chemical Heat Break Check

It is sometimes desirable to be able to simultaneously shut down the temperature and pressure on the system without any time delays. In order to achieve this desire, a heat break system was developed that could allow for:

    • separation of heated and cold material via a heat break,
    • temporary disruptions in dispensing activated material,
    • long term shut down and start up scenarios, and
    • immediate disruption in temperate and/or pressure.

The present invention thus provides an alternative embodiment of a chemical heat break check 110 and methods utilizing the same for preventing the activatable material from flowing back into the non-heated portions of the system when the pressure is relieved. The heat break check 110 prevents irreversible plugs from forming and eliminates the need for complex systems. The heat break check 110 according to the invention is suitable for systems that have both heated and room temperature components. It keeps hot and cool material separate in the system when pressure is relieved on the system.

The heat break check 110 has the same external attributes and features as previously described. However, with reference to FIG. 4, which shows an exploded perspective view of this embodiment of the heat break 110, the heat break 110 further comprises an internal dissipater 190, which as described below, improves the performance of the heat break 110 when pressure on the system is relieved. FIGS. 4 and 5 show cross-sectional views of the fully assembled heat break 110 shown in FIG. 4.

A cold end 170 of the heat break 110 is in fluid communication with an unheated a supply conduit and a hot end 180 of the heat break 110 is in fluid communication with the heated material in the heat exchanger/dispenser. The second heat dissipater 190 in the heat break check 110 induces solidification of heated material within the heat break check when the pressure is relieved and the system is cooled down by allowing the heated material to flow back through a high surface area fitting that is adapted to rapidly heat and/or cool, depending upon whether the system is operating or not. Upon start-up, the novel design of heat break check allows the plug 200 (see FIG. 6) that was formed in the heat break check upon shutdown to be reheated, plastified and/or liquefied sufficiently to allow the pressure of the system to reversibly push it in the heat exchanger thereby eliminating unwanted irreversible drops in pressure or stoppage of the dispensing system. The subject of this invention contained an external heat dissipater 150 and an internal heat dissipater 190. The external heat dissipater served the conventional purpose described above. The internal heat dissipater 190 includes a high surface area pin 220 and a groove portion 230, which is cooled by the incoming glue during normal operation. When the pressure is disrupted or rapidly turned off, the activated material pushes back toward the pin 220, where it undergoes rapid cooling and thereby creates a solid plug 200, which acts a chemical check allowing the system to begin normal dispensing even after an abnormal disruption in dispensing. This plug 200 can be dislodged via pressure supplied by the pump 60, when normal operations resume.

Thus, a heat break 110 according to this embodiment of the invention comprises:

    • a first insulator 80 made of a non-conductive material, most preferably constructed from PEEK, and
    • a heat dissipater 150 made of a conductive material, most preferably aluminum,
    • an internal heat dissipater 190 made of conductive material, most preferably constructed of aluminum, and optionally
    • a second insulator 160, preferably made of PEEK,

Most preferably, the combination of the friction loss coil and heat break check allows for a system that experience gradual pressure loss on shutdown and cooling that result in a system that is substantially pressure equalized from the reservoir to the heat break check. This unique combination avoids unwanted pressure differentials thereby eliminating areas of separated dry and liquid components, cooled activatable material in undesirable locations in the cool areas, and results in clean start-ups and production sequences.

The following examples are intended only to illustrate the invention and should not be construed as imposing limitations upon the claims.

Test Procedures Standard Test Procedure 1: Viscosity

The viscosities were measured with a Brookfield viscometer after the spindle had equilibrated for 10 minutes.

Standard Test Procedure 2: Centrifuge Stability

Centrifuge tubes were loaded with the pumpable liquids and centrifuged for greater than 30 minutes. The tubes were compared for separation into the various components and rated on a scale of good to poor.

Standard Test Procedure 3: Bond Time

Bond time testing was carried out by pumping the liquid emulsion, dispersion or suspension at a specified pressure on a hydraulic pump with a 15:1 pumping ratio to a reactor set at a variable temperature generally described in the '859 patent. The heating and any resultant chemical reactions occurred in the period of time defined as being the moment the Liquid Polymer Composition sample entered the heated reaction zone in the reactor to the moment that the dispensed material solidified on as a foamed solid material on a substrate.

To determine the weight of adhesive composition applied, a 1.5 inch strip of adhesive was dispensed onto a piece of masking tape. After the adhesive cooled, the 1.5 inch adhesive strip was removed from the masking tape and weighed. This was done three times and the average of the weights was registered as the Average Weight of Bead to normalize the data taken on the adhesive performance.

To determine adhesive performance, a corrugated cardboard substrate was first attached to a 656 g base plate and then a 1.5 inch strip of the adhesive composition was dispensed on the substrate while the substrate (attached to said plate) was passed under a liquid hot melt dispenser (specifically a Hydromatic™ from Liquid Polymer Corporation, Lorain, Ohio) at a conveying speed of 75′ per minute. After dispensing the adhesive, and after waiting for a variable period of pre-lamination time (t1), a second corrugated substrate of equal dimensions was laminated to the top of the first substrate under constant pressure for a variable period of time under pressure (t2). Next, the second substrate was vertically lifted to test the laminated structure's ability to support the weight of the base plate without delaminating. The shortest period of time under pressure (t2) that can be tolerated without leading to delamination was defined as the Bond Time (three consecutive passing tests of separate laminates are required before a process condition was deemed to yield a Bond Time). The Normalized Bond Time was then derived at by taking the (Bond Time t2)*Average Weight of Bead)/0.10 grams. A shorter Bond Time correlates with faster and more effective adhesives.

Standard Test Procedure 4: Hand Gun Test

Processability was measured by pumping the liquid emulsion, dispersion or suspension at a specified pressure on a hydraulic pump with a 15:1 pumping ratio to a reactor set at a variable temperature generally described in the '859 patent. The heating and any resultant chemical reactions occurred in the period of time defined as being the moment the liquid sample entered the heated reaction zone in the reactor to the moment that the dispensed material solidified on as a foamed solid material on a substrate. The test was run at 50 psi using a TurboActivator (equipment available from Liquamelt Corp.) at 350° F. and hand gun at 350° F. A simple protocol for pass/fail was developed. If the equipment was able to dispense for 20 seconds it was considered a pass. Anything less than this was considered a failure.

Standard Test Procedure 4: Plastic Bond Test

Plastic Bonding was measured by pumping the liquid emulsion, dispersion or suspension at a specified pressure on a hydraulic pump with a 15:1 pumping ratio to a reactor set at a variable temperature generally described in the '859 patent. The heating and any resultant chemical reactions occurred in the period of time defined as being the moment the liquid sample entered the heated reaction zone in the reactor to the moment that the dispensed material solidified on as a foamed solid material on a substrate. The test was run a 60 psig, TurboActivator at 350° F. and hand gun at 350° F. A simple protocol for pass/fail was developed. A bead was applied to a polyester plastic film, followed by the application of urethane foam and fiber strap. If the foam the foam tore, it was considered a pass-if it did not tear, it was a failure. If the fiber strap held upon pulling by hand, it was considered a pass-if it did not hold, it was a failure. To pass the test, both the foam and strap evaluations had to pass.

Standard Test Procedure 5: Equipment Configuration Test Protocol:

A reservoir or container containing the unactivated liquid material is fluidly connected to the high pressure hydraulic system consisted of a Graco Fireball Pneumatic Piston Pump 15:1 which pumps the unheated material from the low pressure side to the high pressure side of the system. The standard material used in this test is LM1250, available from Liquamelt Corp. Upon exiting the pump, it is connected to a brass ½″ inside diameter check valve which hooked up a manifold. A 10 foot hydraulic hose is fluidly connected to the manifold. The standard pressure for testing the performance of the heat break system was 60 psig which translates to approximately 900 psi hydraulic pressure on the hydraulic hose.

Optionally, a friction loss outlet is also fluidly connected to the manifold depending on the particular testing to be carried out.

The outlet of the hydraulic hose was fluidly connected with various heat break configurations for testing.

Pressurized unheated material flows sequentially through the heat break or heat break check and then a heat exchanger. The heat exchanger heat-activates and mixes and activates the material, which can be selectively dispensed through a dispenser nozzle. Pressurized unheated material flows sequentially into the heat break configuration to a TurboActivator as described in Jorgenson, et. al. The outlet of the TurboActivator was connected to a standard automatic dispensing device consisting of a standard manifold and gun module with 0.016 inch opening. Both the TurboActivator and manifold temperature were controlled to 350° F.

Raw Material Identification Raw Material Chemicals

The materials and abbreviations listed below are referenced in the following examples:

    • MICROTHENE® FE532 EVA [24937-78-8], 9% vinyl acetate, melt index=9, from Equistar; average particle size=20 microns with a particle size distribution 5-50 microns
    • ATEVA® 1820; poly(ethylene-co-vinyl acetate), 18% vinyl acetate, melt index=3 g/10 min., from Celanese
    • ATEVA® 1941; poly(ethylene-co-vinyl acetate), 19% vinyl acetate, melt index=30 g/10 min., from Celanese
    • ATEVA® 2830; poly(ethylene-co-vinyl acetate), 28% vinyl acetate, melt index=150 g/10 min., from Celanese
    • MAPP-1, Licocene 6252 maleated polypropylene, from Clariant
    • MAPP-2, E-43 maleated polypropylene, from Westlake Chemical Corporation
    • MAPP-3, A-C925 maleated polypropylene, A-C Performance Products, a division of Honeywell Corporation
    • Polypropylene 1, Licocene 6102 polypropylene, from Clariant
    • Polypropylene 2, A-C1660 polypropylene, A-C Performance Products, a division of Honeywell Corporation
    • Polyethylene 1, AC-8 polyethylene, from A-C Performance Products, a division of Honeywell Corporation
    • Polyethylene 2, Licocene 5301 polyethylene, from Clariant
    • Soy Bean Oil RBD (Refined, Bleached, Deodorized), from Archer Daniels Midland Company
    • Water
    • HI-SIL™ T-700 Silica, Silica Thickener, synthetic amorphous silicon dioxide, PPG Industries, Inc.
    • LoVel™ 29 Non-Treated Silica Flatting Agent, synthetic amorphous precipitated silicas, PPG Industries, Inc.
    • Pluronic F-127, surfactant, from BASF
    • Sodium bicarbonate, Industrial grade, from Solvay Chemicals
    • Irganox B225; Tetrakis(methylene(3,5-di-tertbutyl-4-hydroxyhydrocinnamate))methane and Tris(2,4-ditert-butylphenyl) phosphate, Antioxidant, from BASF

Draw Material Chemical Sample Preparation Standard Preparation Procedure 1: Ground Ethylvinyl Acetate Polymers.

While the precise values for the particle size distribution are not critical to the invention, the ethylene vinyl acetate polymers used in the examples were mechanically ground to the size distribution set forth in Table 1 below:

TABLE 1 Rotap Information (U.S. Standard Sieves) % of polymer on screen 35 Mesh Screen (500 microns) <0.5%  40 Mesh Screen (425 microns) <35% 60 Mesh Screen (250 microns) <45% 80 Mesh Screen (180 microns) <45% 100 Mesh Screen (150 microns)  <15% 140 Mesh Screen (106 microns)  <15% Pan (<140 Mesh Screen) <15%

Standard Preparation Procedure 2: Ground Polypropylene.

While the precise values for the particle size distribution are not critical to the invention, the polypropylene polymers used in the examples were mechanically ground to the size distribution set forth in Table 2 below:

TABLE 2 Rotap Information (U.S. Standard Sieves) % of polymer on screen 40 Mesh Screen (425 microns)  <0.5% 60 Mesh Screen (250 microns) <15-35% 80 Mesh Screen (180 microns) <15-25% 100 Mesh Screen (150 microns)   <5-10% 140 Mesh Screen (106 microns)  <10-15% Pan (<140 Mesh Screen) <20-75%

Standard Preparation Procedure 3: Ground Maleated Polypropylene.

While the precise values for the particle size distribution are not critical to the invention, the polypropylene polymers used in the examples were mechanically ground to the size distribution set forth in Table 2 below:

TABLE 3 Rotap Information (U.S. Standard Sieves) % of polymer on screen 40 Mesh Screen (425 microns) <0.5-10%  60 Mesh Screen (250 microns) <15-35% 80 Mesh Screen (180 microns) <15-25% 100 Mesh Screen (150 microns)   <5-10% 140 Mesh Screen (106 microns)  <10-15% Pan (<140 Mesh Screen) <20-75%

PREPARATION OF COMPONENT TWO EXAMPLES Comparative Intermediate Examples 1A-1E

In preparing the comparative examples for intermediates, the polypropylene, polyethylene, oil and/or silica and/or surfactant were heated to >250° F. to create a molten homogeneous liquid. The molten material was allowed to cool to create the first set of comparative Intermediate Examples 1A-1E. This set of examples represents one extreme where the polymers are above the melting point and/or solubility point in the carrier component.

TABLE 4 Comparative Comparative Comparative Comparative Comparative Intermediate Intermediate Intermediate Intermediate Intermediate Ingredient ID 1A 1B 1C 1D 1E Soybean Oil 41.5 41.5 14 13.5 13.5 Polypropylene-1 16.5 0 8 2 2 Polyethylene-1 0 3 0 1.9 1.9 Silica 0.5 0.5 0.5 0 0 Pluronic F-127 0 0 0 0.2 0

Exemplary Intermediate Examples 2A-2B

In preparing the exemplary examples for intermediates, the polypropylene, polyethylene and silica were heated to approximately 260° F. to create a molten homogeneous liquid. The molten material was dispensed using a standard hot melt unit with a module fitted with a spray pattern nozzle to dispense the molten liquid into the room temperature soybean oil to create the first set of exemplary Intermediate Examples 2A-2B. In this example, the intermediate was dispersed in oil that created domains where the oil was well below the melting or solubility temperatures but above the room temperature in the regions where the molten homogeneous liquid enters the carrier.

TABLE 5 Exemplary Intermediate Exemplary Intermediate Ingredient ID 2A 2B Soybean Oil 41.5 41.5 Polypropylene-1 16.5 16.5 Polyethylene-1 0 0.25 Silica 0.5 0.5

Exemplary Intermediate Examples 3A-3C

In another embodiment of the invention the oil and silica were heated to approximately 200 to 230° F. and the highest melting polymers which had melting points of about 300° F., polypropylene and maleated polypropylene, were added, stirred and allowed to bring the temperature down to less than 190° F. where the polymer having lower melting points of about 200° F., polyethylene, was added stirred and allowed to cool.

TABLE 6 Comparative Comparative Comparative Intermediate Intermediate Intermediate Ingredient ID 3A 3B 3C Soybean Oil 41.5 41.5 40.5 Polypropylene-1 16.5 16.5 16.5 Maleated PP-1 0 0 4 Polyethylene-1 0 3 3 Silica 0.5 0.5 0.5 % Premix Total 58.5 61.5 64.5

Exemplary Intermediate Examples 4A-4E

In another embodiment of the invention the oil and silica was heated to approximately 130° F. and the highest melting polymers which had melting points of about 300° F., polypropylene and maleated polypropylene, were added, at which time the polymer having lower melting points of about 200° F., polyethylene, was added stirred and then the entire mixture was heat to 145° F. and the temperature is maintained for 20 minutes and then allowed to cool. Examples 4A and 4C.

Example 4B follows the same process as described for example 4A except for that at 100° F., the EVA is added to the formulation and mixed for 5 minutes. The mixture is then allowed to cool.

Example 4D follows the same process as described for example 4A except that instead of Silica, Pluronic F-127 surfactant is added to the oil at the start of the process.

Example 4E follows the same process as described for example 4A except that Irganox B225 is added to the oil silica mixture at the start of the process.

TABLE 7 Exemplary Exemplary Exemplary Exemplary Exemplary Intermediate Intermediate Intermediate Intermediate Intermediate Ingredient ID 4A 4B 4C 4D 4E Soybean Oil 41.5 41.5 41.5 41.5 41.5 Polypropylene-1 16.5 16.5 — 2 16.5 Polypropylene-2 — — 16.5 14.8 — Maleated PP-1 4.1 4.1 4.1 4 4.1 Polyethylene-1 3 3 3 3 3 Silica 0.5 0.5 0.5 0 0.5 Pluronic F-127 0 0 0 0.2 0 Ateva 1820 0 24.3 0 0 0 Irganox B225 0 0.1 0 0 0.1 % Premix Total 65.6 90 65.6 65.5 65.7

Exemplary Intermediate Examples 5A-5B

In another embodiment of the invention the oil was heated to approximately 100° F. at which point the Ateva 2830 EVA is added to the mixing, heated oil. Once the Ateva 2830 EVA is dispersed into the oil, Pluronic F-127 (surfactant) is added followed immediately by the Irganox B225 (antioxidant) and the Sodium Bicarbonate. As the temperature reached 110° F., the mixture is charged with polypropylene. As the temperature reached 115° F., the mixture is charged with maleated polypropylene. The temperature is then increased to 130° F., at which point the heat is turned off and the mixture was then allowed to cool. Example 5A.

Example 5B follows the same process except for the fact that once all the dry raw materials were charge to the heated oil, the formulation was heated to a maximum temperature of 125° F. for a period of 15 minutes prior to removing the heat and allowing the mixture to cool.

Example 5C follows the same process as 5A except for the fact that once all the dry raw materials were charge to the heated oil, the formulation was heated to a maximum temperature of 125° F. at which point the heat was removed allowing the mixture to cool.

Example 5D follows the same process as 5C except for the fact that it does not contain Sodium Bicarbonate.

Example 5E follows the same process as 5C except for the fact that it does not contain either Sodium Bicarbonate or Pluronic F-127 surfactant.

TABLE 8 Comparative Comparative Comparative Comparative Comparative Intermediate Intermediate Intermediate Intermediate Intermediate Ingredient ID 5A 5B 5C 5D 5E Soybean Oil 30 43 43 41.92 42.56 Polypropylene-1 3 3 2.92 2 Polypropylene-2 7.85 7.85 7.85 7.65 10.02 Maleated PP-1 2.5 2.5 2.44 4.5 Maleated PP-2 4 4 4 3.9 — Polyethylene-2 — — 2.25 2.19 2.26 Pluronic F-127 0.2 0.2 0.2 0.2 — Ateva 2830 EVA 2.5 2.5 2.5 2.44 2.51 Irganox B225 0.15 0.15 0.15 0.15 0.15 Sodium Bicarbonate 0.1 0.1 0.1 — — % Premix Total 44.8 63.3 65.55 63.81 64

COMPARATIVE EXAMPLES Low Viscosity Shelf Stable Materials Viscosity/Stability Results

In each case the Intermediate was cooled close to room temperature and the additional ingredients were blended up to make the final room temperature pumpable emulsion, dispersion or suspension. 1A shows the expected results of a solid as with the liquid carrier no longer being effective in providing a pumpable liquid. The products provided utilizing 2A and 3A show remarkably low viscosity and stability when compared to 1A. In the preferable process, 3A and 3B demonstrates that very high solids content, low viscosity and shelf life stability can be simultaneously obtained. In the even more preferable process, 4A demonstrates that even higher solids content, low viscosity and shelf life stability can be simultaneously obtained.

TABLE 9 Intermediate ID 1A 2A 3A 1B 2B 3B 4A % % % % % % % Intermediate 58.5 58.5 58.5 45 58.75 61.5 65.6 Soybean Oil — — — — — — — Water 1 1 1 1 1 1 1 Polypropylene-1 0 0 0 16.5 0 0 — Polypropylene-2 — — — — — — — Polyethylene-1 3 3 3 0 2.75 0 — MAPP-1 4.2 4.2 4.2 4.2 4.2 4.2 — FE 532 (EVA) 9 9 9 9 9 9 9 ATEVA 1820 24.3 24.3 24.3 24.3 24.3 24.3 24.3 Pluronic F-127 — — — — — — — Irganox B225 — — — — — — 0.1 Viscosity (cps) Solid 14,675 8,225 13,600 16,075 7,050 11,300 Stability NA Good Good Good Good Good Good

Bond Time Testing

Bond time testing was carried according to the test procedures. Results are reported in Table 10 below:

TABLE 10 Ingredient ID 2A 2C 3C 4A FE532 9 9 9 9 1820 EVA 24.3 24.3 24.3 24.3 Soy 41.5 41.5 41.5 41.5 (MAPP) 4.2 4 4.2 4.1 (PP) 16.5 16.5 16.5 16.5 Water 1 1 1 1 AC 8 (PE) 3 3 3 3 Pluronic F-127 0 0 0 0 LoVel 29 0.5 0.5 0.5 0.5 Irganox B 225 — — — 0.1 Viscosity (cP) 14675 15750 7000 11300 Stability Good Good Good Good 320° F./50 PSI (sec) 0.7 0.7 0.6 0.5 Bead Weight (g) 0.07 0.06 0.08 0.07 320° F./90 PSI (sec) 0.6 0.4 0.6 0.4 Bead Weight (g) 0.24 0.25 0.19 0.22 350° F./70 PSI (sec) 0.5 0.5 0.5 0.5 Bead Weight (g) 0.21 0.20 0.18 0.18 380° F./90 PSI (sec) 0.7 0.6 0.6 0.5 Bead Weight (g) 0.1 0.12 0.11 0.13 380° F./90 PSI (sec) 0.7 0.8 0.5 NA Bead Weight (g) 0.35 0.39 0.31 0.33 NA = Material too low, viscosity causing bounce off.

The foregoing examples demonstrate the criticality of oil temperature relative to the temperature of the polymers in the formation of a low-viscosity intermediate. When the temperature of the oil is near, but below, the melting point of the polymers used in the composition, intermediates (Examples 3A-3C, 4A) can be obtained that have lower viscosity as compared to intermediates obtained when the oil is at a temperature above the melting point of the polymers (Examples 1A-1C). The methods of the invention can be utilized to prepare compositions that exhibit long-term stability and low viscosity.

Unique Bonding and Application in Plastic Assembly Example

TABLE 11 Hand Gun Test Results Intermediate ID None 4C 4E 1D 1E 4D 5A 5B % % % % % % % % Intermediate % 0 65.6 65.7 17.6 17.4 65.5 44.8 63.3 Soybean Oil 41.5 — — 28 28 — 13 — Water 1 1 1 1 1 1 1.25 1.25 Polypropylene- 16.5 0 0 — — — 3 — 1 Polypropylene- — — — 14.8 14.8 — — — 2 Polyethylene-1 3 3 3 1.1 1.1 — — — Polyethylene-2 — — — — — — 2.25 2.25 MAPP-1 4.1 4.2 4.2 4 4 — 2.5 — FE 532 (EVA) 9 9 9 8.95 8.95 8.95 9.2 9.2 ATEVA 1820 24.3 24.3 24.3 24.3 24.3 24.3 12 12 (EVA) Ateva 1941 — — — — — — 12 12 (EVA) Pluronic F-127 — — — — — — — — Irganox B225 0.1 — — 0.15 0.15 0.15 — — Silica 0.5 — — — — — — — Sodium — — — 0.1 0.1 0.1 — — Bicarbonate Hand Gun Test Fail Pass Pass Fail Fail Pass Fail Fail Plastic Bond — — Pass Fail — — — Fail Test

The foregoing examples demonstrate the inherent benefit of improved processing in the Turbo Activator® as it relates to the processing of the intermediate. Utilizing the Hand Gun Test protocol, a distinctive relationship between the intermediate process and the ability to pass the test is demonstrated. Intermediates 4C, 4D and 4E all demonstrate the enhanced processability of their final formulation as it relates to the passage of the Hand Gun Test protocol. While the remaining examples in table 11 further support the evidence of the unique benefits of Intermediate Process group 4.

Surprisingly, it was discovered that these compositions not only had the unexpected advantage of being low viscosity and shelf stablility in the preactivation stage; but it performed advantageously on low surface energy plastic substrates. When compositions were prepared according to the invention the resulting product successfully bonded foam to plastic shields and fiber straps to the same shields. The material prepared by conventionally mixing the same raw materials at room temperature failed.

Equipment Stabilization Compositions

TABLE 12 Equipment Stabilizing Compositions Comparative Exemplary Exemplary Exemplary Exemplary Example 6A Example 6B Example 6C Example 6D Example 6E Stabilizer Ingredient Soda Ash Stabilizer Zn(Stearate) ZnO ZnO Package 2 Stabilizer Concentration 0.15 1.24 1 0.1 0.075 Intermediate ID 5C 5C 5C 5D 5E Intermediate % 65.45 64.72 62.98 63.8 64 Soybean Oil — — 0.98 0.99 — Water 1.25 1.24 0.98 0.99 0.99 FF 532 (EVA) 9.19 9.09 8.98 9.11 9.10 ATEVA 1820 (EVA) 23.96 23.72 — — 9.68 Ateva 1941 (EVA) — — 24.65 25.00 16.14 Silica — 0.49 — — — Sodium Bicarbonate — — 0.40 — — Soda Ash 0.15 — — — — Calcium Carbonate — 0.20 — — — Zinc Stearate — 0.20 1.00 — — Zinc Oxide — — — 0.10 0.08 Zinc (Dust) — 0.1 — — — Chemstat HTSA #22-20M — 0.25 — — — Time without Failure (min) — 15500 9,260 20,220 2,640 Time to Failure (min) 3,043 Did not fail Did not fail Did not fail Did not fail Gun Cycles 73,032 372,000 222,240 485,280 63,360 Total module test time 3,043 15,500 9,260 38,210 40,850

The activated material composition in Example 6A failed with a stainless steel needle and seat in a very short period of time which was unexpected. Surprisingly, we found that zinc related materials extended the life of the seat and needle. It was theorized that adding a slip agent, a sacrificial metal ion, or metal stabilizer could interact with the material and equipment to create a stable interface for materials made and used according to the subject invention.

Friction Loss/Process Comparative Examples

TABLE 13 Friction Loss/Process Experiment 7A 7B 7C 7D 7E Resistor NA 30′ aluminum 30′ Aluminum 30′ Aluminum 30′ Aluminum Dispense Time 90 min 50-270 min 10 min  15 min 10 min Variable Changed — Added resistor — Added resistor Left Pressure to 6A in after the check on for 15 between the valve so it can minutes after pump and relieve shutting off check valve pressure temperature Pump Result Fail Pass Pass Pass Pass Product separated in pump Hose Result — NA Fail Pass Pass Dry material plug Heat Break Result — NA Fail Fail Pass Dry material Plug with cured material Start Up Evaluation Fail NA Weak then Fail Fail Pass Temperature Off  0 min 0 min 0 min  0 min  0 min Pressure Off  0 min 0 min 0 min  0 min 15 min Time to Cool NA NA 45 min  45 Min 45 min Turbo

Standard Test Procedure 6 for equipment testing was used in Examples 7A-7E. The heat break configuration is the subject of this invention; peek-aluminum-peek. Test Comparative Example 7A and exemplary Example 7B clearly demonstrate the advantage of a friction loss component (resistor) in ensuring the pressure differentials found in the pump do not lead to unwanted separation of the polymer and carrier which ultimately create unwanted packouts. Examples 7C-7E demonstrate that the location of the friction loss component (resistor) not only insures the smooth operation of the hydraulic pump during interruptions and slow dispensing; but allows for a reversible plug to be formed and allows for the system pressure to be gradually released thereby minimizing pressure differentials which lead to separation which can result in poor start ups to total failure of the system starting.

Chemical Heat Break Examples

TABLE 14 Friction Loss/Process Heat break Experiment # description 8A 8B 8C 8D 8E 8F First Component NA Peek Aluminum Peek Peek Peek Second Component NA NA Peek Aluminum Aluminum Aluminum Third Component NA NA NA NA Peek Peek Chemical Check NA NA NA NA NA Yes Heat break ID NA ⅛″ ¼″ ¼″ ¼″ ¼″ Plug Location 6″ into 2″ into 0.2″ into 0.2″ into Plug stops Plug stops hydraulic hydraulic hydraulic hydraulic half way half way hose hose hose hose through through third second component component Start Up Evaluation Fail Fail Fail Fail Weak Pass

Standard Test Procedure 6 for equipment testing was used in Examples 8A-8F. Test Comparative Example 8A-8C clearly demonstrate the necessity of a heat break in the system and show the advantage of a larger diameter for the activated material move forward and backward as the system experiences different conditions. Examples 8D-8F demonstrate the importance of the chemical check component of the heat break design. The chemical check forces the plug to stop mid way through the aluminum, this allows the plug to be reactivated on a startup and pushed through the system. By reactivating the plug, material can be moved through the system efficiently, providing a clean startup. If the plug is located past the aluminum component, the plug cannot be reactivated and startup will be considered weak or a failure, as demonstrated in examples 8D-8E.

Additional advantages and modifications will readily occur to those skilled in the art. Therefore, the invention in its broader aspects is not limited to the specific details and illustrative examples shown and described herein. Accordingly, various modifications may be made without departing from the spirit or scope of the general inventive concept as defined by the appended claims and their equivalents.

Claims

1-22. (canceled)

22. A delivery system for a thermally activatable composition, the delivery system having:

a low pressure side comprising a reservoir for receiving the thermally activatable composition; and
a high pressure side comprising a pump having an input side for receiving a flow of the thermally activatable composition from the reservoir, wherein the high pressure side further comprises a heat break between the input side and the heat exchanger/dispenser, said heat break comprising: a first insulator, with a first end connected to the heat exchanger/dispenser and; a tubular heat dissipator made of a conductive material,
the first end of said heat dissipator being connected to the second end of the first insulator.

23. (canceled)

24. The delivery system according to claim 22 wherein the heat break further comprises:

a second insulator connected to the second end of the tubular heat dissipater.

25. The delivery system according to claim 24 wherein the heat break further comprises an internal heat dissipater having a pin portion extending into the inner channel of the tubular heat dissipater and grooves that allow the thermally activatable composition to pass through the heat break to the heat exchanger/dispenser.

26. The delivery system according to claim 25 wherein when the pressure is rapidly reduced on the high pressure side, thermally activatable material that has been heated cools to form a chemical plug between the pin portion of the internal heat dissipater and inner walls of the tubular heat dissipater defining the inner channel therethrough, the chemical plug being dislodgeable when pressure is reapplied to the high pressure side of the delivery system.

27. A heat break for use in a high pressure side of delivery system for a thermally activatable composition that includes a heat exchanger/dispenser, the heat break comprising

a first insulator connected to the heat exchanger/dispenser; and
a tubular heat dissipater including an inner channel, said tubular heat dissipater being connected to the first insulator.

28. The heat break according to claim 27 wherein the heat break further comprises a second insulator connected to the tubular heat dissipater.

29. The heat break according to claim 28 wherein the heat break further comprises an internal heat dissipater having a pin portion extending into the inner channel of the tubular heat dissipater and grooves that allow the thermally activatable composition to pass through the heat break to the heat exchanger/dispenser.

30. The heat break according to claim 29 wherein when the pressure is rapidly reduced on the high pressure side of the delivery system, the heat break is adapted to cause thermally activatable material that has been heated to cool to form a chemical plug between the pin portion of the internal heat dissipater and inner walls of the tubular heat dissipater defining the inner channel therethrough, the chemical plug being dislodgeable when pressure is reapplied to the high pressure side of the delivery system.

31. The heat break according to claim 27 wherein the outer surface of the tubular heat dissipator comprises a plurality of heat sink fins.

32. The heat break according to claim 27 wherein the heat dissipator is made of a conductive material.

33. The heat break according to claim 32 wherein the conductive material is aluminum.

34. The delivery system of claim 22 further comprising a friction loss coil.

Patent History
Publication number: 20130186913
Type: Application
Filed: Dec 10, 2010
Publication Date: Jul 25, 2013
Applicant: H.B. Fuller Company (St. Paul, MN)
Inventors: Michael W. Jorgenson (Quincey, IL), Danielle E. Koeth (Cleveland, OH), Jeffrey C. Krotine, JR. (Strongsville, OH)
Application Number: 13/514,835
Classifications
Current U.S. Class: With Heating Or Cooling Means (222/146.1)
International Classification: B65D 83/14 (20060101);