SURFACE DEFECT TREATMENT COMPOSITIONS

A surface defect treatment composition for repairing defects in coated substrates comprising: abrasive consisting essentially of inorganic particles having an average particle size of from about 0.1 to about 12.0 microns and a surface area of from about 6 to about 17 m2/g; and, an emulsion comprising one or more organopolysiloxanes

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Description

The present application claims the benefit of pending U.S. Provisional Patent Application Ser. No. 60/731,827, filed Oct. 31, 2005 the entire disclosure of which is hereby incorporated by reference.

FIELD OF THE INVENTION

The present application relates to surface defect treatment compositions, and to methods of using such compositions to treat defects at the surface of coated substrates.

BACKGROUND OF THE INVENTION

Defects that arise in the surface of a coated substrate, such as scratches, not only greatly reduce the surface aesthetics of the coated substrate but can lead to premature failure of the coated substrate. Compositions used to treat surface defects often comprise inorganic abrasive particles, which may damage the surface surrounding the defect, thereby reducing the gloss of the surrounding surface.

Compositions are needed to repair surface defects without damaging the surrounding surface.

SUMMARY OF THE INVENTION

The present application provides a surface defect treatment composition for repairing defects in coated substrates comprising: abrasive consisting essentially of inorganic particles having an average particle size of from about 0.1 to about 12.0 microns and a surface area of from about 6 to about 17 m2/g; and, an emulsion comprising one or more organopolysiloxanes.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1-2 represent scratch measurements using Confocal Laser Scanning Microscopy of the black panel of Example 1, before and after treatment, respectively.

FIGS. 3-4 represent scratch measurements using Confocal Laser Scanning Microscopy of the red panel of Example 1, before and after treatment, respectively.

FIGS. 5-6 represent scratch measurements using Confocal Laser Scanning Microscopy of the white panel of Example 1, before and after treatment, respectively.

DETAILED DESCRIPTION

The present application provides a composition useful for treating defects in the surface of coated substrates. As used herein, the phrase “coated substrates” refers to substrates comprising a coating formed using a paint system. Coatings formed using paint systems typically comprise one or more of the following coatings: primer; base coat; and, clear coat. A “primer” is a surfacer that fills in imperfections in the substrate. The primer also typically provides a conductive layer to facilitate the electrostatic application of subsequently applied coating layers. A “base coat” is a coating layer, for example a pigmented enamel layer, that provides color and aesthetic effects. A “clear coat,” if present, generally interfaces with the environment. Typical clear coats include acrylic melamine and acrylic urethane polymers. A “top coat” refers to the combination of a base coat and a clear coat.

The substrate may comprise substantially any solid material, In one embodiment, the solid material is, for example, metal, metal oxide, plastic, or fiber reinforced plastic. In one embodiment, the coated substrate is a component of an automobile, for example, a bumper or an automobile body.

The surface defect treatment composition repairs defects in coated substrates. The word “defect” refers to the absence of paint or coating which has been filled with air instead of primer and/or top coat and includes, for example, scratches, mars, abrasions, scuffs, and writing effects. The surface defect treatment composition repairs defects while minimizing damage to the surrounding coating surface. In particular, the present composition works to repair defects without significantly changing the glossiness of the surrounding coated substrate.

Gloss or glossiness is an optical phenomenon caused when evaluating the appearance of a surface. The evaluation of gloss describes the capacity of a surface to reflect directed light. In the case of glossy surfaces, light reflection from the surface follows the reflection law (i.e., the angle of illumination=angle of reflection). The intensity of the reflected light is dependent on the angle of illumination and the surface property. Generally, a decrease in glossiness is a relative indication of the severity of damage to a coated substrate.

The present surface defect treatment composition repairs defects at a coated surface with minimal damage to the surrounding coated substrate, as demonstrated by one or more of: (a) an increase in scratch diminishment after treatment; (b) an increase in gloss after treatment; and/or (c) a decrease in scratch width and/or depth. The surface defect treatment composition comprises a combination of polyorganosiloxane and relatively non-aggressive inorganic particles as abrasive.

The surface defect treatment composition performs a number of functions, for example, enhancing of the appearance of defects, increasing the durability of the repaired region, minimizing damage to the surrounding coated substrate (i.e., minimizing the change in glossiness to the surrounding top coat). The surface defect treatment composition may be applied in any suitable manner, such as by rubbing or spraying onto the surface. In one embodiment, the surface defect treatment composition is applied by rubbing the composition directly onto the defect. In another embodiment, the surface defect treatment composition is applied to the defect using a scratch pen.

The Abrasive

The abrasive essentially smoothes out the defect. In one embodiment, the abrasive consists essentially of inorganic particles. The constitution of the inorganic particles may vary depending on the method of application, the defect, the coating involved, and the level of aggressiveness desired.

The aggressiveness of the abrasive is determined, among other things, by the average particle size of the inorganic particles and the hardness of the inorganic particles. The hardness of the inorganic particles is a function of the particle surface area.

The desired average particle size will depend on a number of factors, for example, the desired workability of the surface defect treatment composition and the method of application. In one embodiment, the average particle size of the inorganic particles is from about 0.1 to about 12.0 microns. In one embodiment, the average particle size of the inorganic particles is from about 2 to about 5 microns. In another embodiment, the inorganic particles have an average particle size of from about 2.0 to about 3.2 microns.

Depending on the average particle size, the inorganic particles have a surface area of from about 6 to about 17 m2/g. In one embodiment, the inorganic particles have a surface area of from about 6 to about 15 m2/g. In another embodiment, the inorganic particles have a surface area of from about 8 to about 15 m2/g. In an advantageous embodiment, the inorganic particles have a surface area of from about 8 to about 11 m2/g.

In a particularly advantageous embodiment, the inorganic particles have an average particle size of from about 2.0 to about 3.2 microns and a surface area of from about 8 to about 11 m2/g. In an advantageous embodiment, the inorganic particles have an average particle size of about 3 microns and a surface area of from about 8 to about 11 m2/g. These embodiments are particularly advantageous for direct manual application, for example, using a scratch pen.

The inorganic particles may be any inorganic particles having the required average particle size and surface area. Suitable inorganic particles include, for example, aluminas, aluminates, silicas, silicates, and derivatives thereof. Specific examples of suitable particulates include, for example, aluminum oxide, silica, alpha-alumina, amorphous alumina silicate, amorphous silica, and crystalline silica. In one embodiment, the inorganic particles comprises an aluminum complex powder, In a particularly advantageous embodiment, the aluminum complex powder comprises alpha-alumina. Suitable inorganic abrasive particles are commercially available from a variety of sources. One example of such source is Bernatex Corporation, 63 Middlesex Street, North Chelmsford, Mass. Another exemplary source of inorganic particulates is World Minerals, Inc., Lompoc, Calif.

In one embodiment, the surface defect treatment composition comprises from about 3 wt. % to about 7 wt. % abrasive. In a second embodiment, the surface defect treatment composition comprises from about 4.5 wt. % to about 5.5 wt. % abrasive. In a particularly advantageous embodiment, the surface defect treatment composition comprises about 5.0 wt. % abrasive.

The Gloss Enhancer

The surface defect treatment composition also comprises a gloss enhancer In one embodiment, the gloss enhancer is organopolysiloxane. Organopolysiloxanes enhance surface wettability and adhesion of the surface defect treatment composition to the surface of the coated substrate. In one embodiment, the gloss enhancer is an emulsion comprising one or more organopolysiloxanes.

Suitable organopolysiloxanes are described in US. Pat. No. 6,206,956, incorporated herein by reference. The organopolysiloxanes include, for example, poly(dialkyl)siloxanes and organopolysiloxanes comprising functional groups such as aminoallyl groups and ethylenically unsaturated groups. In general, suitable organopolysiloxanes have the formula
[RaSiO(4−a)/2]n
wherein:

  • R independently is selected from the group consisting of monovalent hydrocarbon radicals, hydroxy radicals, and hydrocarbonoxy radicals having from 1 to 18 carbon atoms, wherein the radicals may comprise one or more functional group including, for example, amino groups, mercapto groupers olefinic groups, and aromatic groups;
  • a is on average from 0.7 to 2.6 per unit of the organopolysiloxane, and
  • n is from 10 to 10,000.

Both branched and linear organopolysiloxanes are suitable. In one embodiment, the organopolysiloxane comprises repeating units having the following general structure:
wherein R1 and R2 individually are selected from the group consisting of phenyl groups, alkyl groups having from about 1 to 18 carbon atoms which are either saturated or comprise one or more unsaturated carbon-carbon bond. In one embodiment, R1 and R2 are methyl groups. In other embodiments, R1 and R2 are aminoalkyl groups and salts thereof. Suitable amino alkyl groups include, for example, ω-amino-C1-8 alkyl and polyaminopolyalkyl groups. Suitable polyaminoalkyl groups include, for example, aminoethylaminopropyl groups, and salts thereof. Suitable unsaturated groups include, for example, vinyl groups, allyl groups, propenyl groups, isopropenyl groups, terminal C4-18 alkenyl groups, alkynyl groups, vinyl ether groups, and allyl ether groups. The organopolysiloxanes also may comprise C1-8 alkoxy groups. Suitable alkoxy groups include, for example, methoxy groups and ethoxy groups. The organopolysiloxanes may be terminated with end groups including, for example, trialkylsilyl groups, dialkylsilanolyl groups, dialkylalkoxysilyl groups, alkyldialkoxysilyl groups, and dialkylvinylsilyl groups. In one embodiment, the organopolysiloxanes are polydimethylsiloxanes end-capped with dimethylsilanolyl groups, or more preferably, trimethylsilyl groups. This list of organopolysiloxane fluids is illustrative and not limiting.

More generally, the organopolysiloxanes are those which can be readily dispersed to form aqueous emulsions, and which are stable to gellation in the aqueous composition. Mixtures of various organopolysiloxanes may be used as well, particularly mixtures of organopolysiloxanes of differing viscosities, for example, mixtures of low and high viscosity siloxanes. Such mixtures include, for example, mixtures of siloxanes having viscosities in the ranges of 10 cSt to 10,000 cSt and 1000 cSt to 1,000,000 cSt, with the siloxane in latter range being of higher viscosity than that in the former range, as measured at 25° C. according to ASTM D2983 (-93). The organosiloxane, whether a single organosiloxane or a mixture, suitably has a Brookfield viscosity of 10 to 60,000 cSt, In one embodiment, the Brookfield viscosity is from 100 to 3000 cSt. In another embodiment, the Brookfield viscosity is from 300 to 500 cSt.

The organopolysiloxanes are employed in the form of an aqueous emulsion. In one embodiment, the emulsion is an oil-in-water emulsion of the polydimethylsiloxane. In a particularly advantageous embodiment, the oil-in-water emulsion comprises polydimethylsiloxane having a viscosity of about 350 cSt. A commercially available emulsion is 350 cSt Silicone Emulsion, available from Wacker Silicones Corporation, which comprises about 60 wt. % polydimethylsiloxane.

In one embodiment, the surface defect treatment composition comprises from about 3 wt. % to about 7 wt. % organopolysiloxane emulsion, resulting in a total concentration of organopolysiloxane of from about 1.8 wt. % to about 4.2 wt. %, based on the total weight of the surface defect composition. In another embodiment, the surface defect treatment composition comprises from about 4 wt. % to about 6 wt. % organosiloxane emulsion, resulting in a total concentration of organopolysiloxane of from about 2.4 wt. % to about 3.6 wt. %, based on the total weight of the surface defect composition. In an advantageous embodiment, the surface defect treatment composition comprises about 5.0 wt. % polydimethylsiloxane, resulting in a concentration of polydimethylsiloxane of from about 3 wt. %, based on the total weight of the surface defect composition.

Other Components

The surface defect treatment composition also may comprise additional components. Suitable additional components include, for example, water, preservative, lubricant, and dispersant.

Aqueous Base

In one embodiment, the surface defect treatment composition comprises an aqueous base. Suitable aqueous bases include, for example, tap water and purified water. Purified water includes, for example, distilled water, deionized water, and water purified by reverse osmosis. Suitably, the aqueous base does not contain ions that may adversely affect the performance of the other components of the surface defect composition and/or encourage microbial growth in the treated region of the coated substrate.

A particularly advantageous aqueous base is deionized water. In one embodiment, the surface defect treatment composition comprises from about 78 wt. % to 88 wt. % aqueous base. In a second embodiment, the surface defect treatment composition comprises from about 82 wt. % to about 84 wt. % aqueous base. In one embodiment, the defect treatement composition comprises about 83 wt. % aqueous base.

Preservative

The surface defect treatment composition may comprise one or more preservatives. Preservatives are useful (1) to prevent spoilage of the composition during storage, and (2) to prevent discoloration and microbial deterioration of the treated surface. A variety of preservatives may be used.

In one embodiment, the surface defect treatment composition comprises preservative comprising, as active ingredients, 5-chloro-2-methyl-4-isothiazolin-3-one (CAS # 26172-55-4) and 2-methyl-4-isothiazolin-3-one (CAS # 2682-20-4), which are commercially available from Rohm & Haas Company. The active ingredient typically is about 1.5 wt. % or less of the total preservative, with the remainder comprising inactive ingredients. Examples of inactive ingredients include, for example, metal salts, water, and/or solvent. Metal salts include, for example, copper salts and magnesium salts. Specific examples of metal salts include, for example, magnesium chloride (CAS # 7786-30-3), magnesium nitrate (CAS#01377-60-3), and cupric nitrate (CAS #10031-43-3).

In a first embodiment, the surface defect treatment composition comprises preservative comprising as active ingredients from about 1.1 wt. % to about 1.2 wt. % 5-chloro-2-methyl-4-isothiazolin-3-one, and from about 0.3 wt. % to about 0.4 wt. % 2-methyl-4-isothiazolin-3-one. In one embodiment, the preservative further comprises, as inactive ingredients, from about 20 wt. % to about 28.5 wt. % magnesium salt and from about 70 wt. % to about 78.5 wt. % water.

In an advantageous embodiment, the surface defect treatment composition comprises preservative comprising about 1.15 wt. % 5-chloro-2-methyl-4-isothiazolin-3-one and about 0.35 wt. % 2-methyl-4-isothiazolin-3-one. In one embodiment, the preservative further comprises about 23 wt. % magnesium salt and about 75.5 wt. % water.

In one embodiment, the surface defect treatment composition comprises from about 0.06 wt. % to about 0.10 wt. % preservative. In a second embodiment, the surface defect treatment composition comprises from about 0.075 wt. % to about 0.085 wt. % preservative. In a particularly advantageous embodiment, the surface defect treatment composition comprises about 0.08 wt. % preservative.

Lubricant

In one embodiment, the surface defect treatment composition further comprises lubricant. Lubricant aids in lubrication and handling of the surface defect treatment composition during application. Lubricant also retains moisture and avoids accumulation of difficult to remove dried residue on the coated substrate. Lubricant also avoids the generation and accumulation of excessive powder or dust on the coated substrate, which can generate static electricity and cause the surface defect treatment composition to adhere to the surface.

Substantially any hydrophilic lubricant may be used. Examples of suitable lubricants include, for example, lubricants comprising hydroxyl groups. In one embodiment, the lubricant comprises trihydric alcohol. In an advantageous embodiment, the lubricant is one or more glycerin and/or other glycerol based lubricants. In a particularly advantageous embodiment, the lubricant comprises glycerine, which is commercially available from a number of commercial sources.

In one embodiment, the surface defect treatment composition comprises from about 3 wt. % to about 7 wt. % lubricant. In a second embodiment, the surface defect treatment composition comprises from about 4.5 wt. % to about 5.5 wt. % lubricant. In a particularly advantageous embodiment, the surface defect treatment composition comprises about 5.0 wt. % lubricant.

Thickener

The surface defect treatment composition suitably comprises one or more thickener. Suitable thickeners include, for example, hydrophilic non-ionic water soluble polymers. Suitable thickeners are effective to perform one or more function selected from the group consisting of thickening, suspending, emulsifying, forming films, dispersing, and retaining water. The thickener also may provide protective colloidal action for the abrasive in the compositions.

In one embodiment, the surface defect treatment composition comprises water-soluble cellulose ethers. In one embodiment, the thickener is hydroxyethyl cellulose (HEC), which is commercially available from a variety of sources including, for example, The Dow Chemical Company.

A sufficient amount of thickener is used to provide the surface defect treatment composition with a desired dynamic viscosity. Suitable dynamic viscosities are from about 20,000 cP to about 50,000 cP, as determined using Brookfield viscosity Measurement including a #4 Spindle at 12 RPM at room temperature (about 20° C.), according to ASTM D-2983(-93). In one embodiment, the dynamic viscosity of the surface defect treatment composition is about 31,200 cP.

In one embodiment, the surface defect treatment composition comprises from about 1.0 wt. % to about 6 wt. % thickener. In a particularly advantageous embodiment, the surface defect treatment composition comprises about 5.0 wt. % thickener.

Additional Components

The surface defect treatment composition also may comprise a variety of other components as long as those components do not interfere with the ability to treat, repair or otherwise improve the appearance of defects without damaging, altering or diminishing the performance of the surrounding surface. Suitable additional components include, for example, pigments, dyes, fragrances, viscosity modification agents, foaming agents, waxes, and propellants.

The surface defect treatment composition is produced simply by mixing the components together. A typical order of addition comprises first adding the aqueous base followed by adding the remaining components in no particular order. Alternately, the other components can be added prior to adding the aqueous base, or all of the components can be added simultaneously with mixing. In one embodiment, the mixture is continuously agitated as each of the components is added.

Surface Defect Treatment

Once a defect is identified in a coated substrate, the composition is applied to the region on the coated substrate comprising the defect. The surface defect treatment composition can be applied to the defect by any suitable method, for example, by spraying, pouring, and/or using a hand held applicator. In one embodiment, the surface defect treatment composition is applied using a scratch pen.

The surface defect treatment composition smoothes out defects without significantly damaging the surface surrounding the defect. One measure of improvement is an increase in scratch diminishment (subjective). Improvement also is indicated objectively by: an increase in mean gloss after treatment of the defect, as measured by an increase in gloss units (GU) using a suitable glossometer, for example, a Byk Gardner micro-Trigloss; and, a decrease in depth and/or width of the defect, as measured by Confocal Laser Scanning Microscopy. A suitable Confocal Laser Scanning Microscope may be obtained, for example, from Leica Microsystems, 410 Eagleview Blvd., Exton, Pa.

The application will be better understood with reference to the following examples, which are illustrative only:

EXAMPLE 1

A surface defect treatment composition having the following formula was prepared. The numerical values in Table 1 represent weight percent based on the weight of the total composition.

TABLE 1 Components Wt. % Deionized Water 83.62% Water based preservative 0.08% 5-chloro-2-methyl-4-isothiazolin-3-one1 (1.15%) 2-methyl-4-isothiazolin-3-one2 (0.35%) Magnesium Salts (23%) Water (75.5%) Abrasive 5.00% Glycerin 5.00% Hydroxyethyl Cellulose 1.30% 3350 cSt Silicone Emulsion3 5.00%
1Obtained from Rohm & Haas Company.

2Obtained from Rohm & Haas Company.

3Obtained from Wacker Silicone Corporation.

The abrasive was MIR-100 3 Micron (100% alpha alumina) having an average particle size of about 3 microns with a surface area of from 8 to 11 m2/g, obtained from Bernatex Corporation.

EXAMPLE 2

One each of black, red, and white colored panels were inflicted with scratches by rubbing each of the panels using cloth or paper towel against ISO 12103-1 A1 Ultrafine Test Dust. In each of the three panels, 10 randomly located scratches were made to eliminate location dependence. Next, each panel was cleaned with a towel to remove dirt and other contaminants.

Initial readings for each of the scratches on all three panels were taken prior to treatment with the composition described in Table 1 by visual means. Once initial readings for each scratch were recorded, the composition was applied to each scratch as discussed above. Following application of the composition, readings were once again taken for each scratch by visual means.

A subjective scratch diminishment scale was used for rating the visual scratch removal effectiveness of the composition—from 1 to 7, (i.e., 1 being the worst—scratch not removed to 7 being the best—scratch completely removed). Visual inspection included evaluation conducted by human eye and was subject to several factors including the surface characteristics of the panel, the quality of the observer's eyesight, and the observer's perceptions. These factors were influenced by both physics and physiology.

Tables 2-4 below represent subjective scratch diminishment scale results for each scratch of the black, red, and white panels.

TABLE 2 BLACK COLOR PANEL Location on Scratch Diminish Scale Scratch Diminish Scale Panel before Treatment after Treatment 1 1 6 2 1 7 3 1 7 4 1 6 5 1 6 6 1 6 7 1 6 8 1 7 9 1 7 10 1 7

TABLE 3 RED COLOR PANEL Location on Scratch Diminish Scale Scratch Diminish Scale Panel before Treatment after Treatment 1 1 7 2 1 7 3 1 7 4 1 7 5 1 7 6 1 7 7 1 7 8 1 7 9 1 7 10 1 7

TABLE 4 WHITE COLOR PANEL Location on Scratch Diminish Scale Scratch Diminish Scale Panel before Treatment after Treatment 1 1 7 2 1 7 3 1 7 4 1 7 5 1 7 6 1 7 7 1 7 8 1 7 9 1 7 10 1 7

The above results demonstrate a scratch removal efficiency based on the overall scratch diminishment scale of better than 95% confidence level. The white and red panels showed greater scratch removal than the black panel.

Microscopic topographical readings were used to measure the dimension change of each scratch in terms of length, width and depth. In the testing:

  • (1) Five gloss measurements were taken before and after treatment to obtain average gloss values and to establish the repeatability of the test.
  • (2) The repeatability of the test was used to determine whether the signal to noise (experimental error) ratio was high enough to obtain statistical significance.
  • (3) Samples were tested in two stages: (a) scratched part; and (b) treated part.
  • (4) Statistical analyses were performed to determine the statistical significance between the pre-treatment parts vs. the treated parts.

FIGS. 1-6 represent scratch measurements using Confocal Laser Scanning Microscopy for one random scratch on each of the black, red, and white panels—both prior to treatment and after treatment. At 100 times magnification, the cross-sectional pictures showed clear improvement in the appearance of each scratch, as well as reduction in the size of scratches. The results are as follows:

Black Panel Cross-section Profile Analysis (FIGS. 1 and 2):

    • The width of the groove reduced from about 30 microns to about 0 microns
    • The depth of the groove reduced from about 2 microns to about 0 microns.
      Red Panel Cross-section Profile Analysis (FIGS. 3 and 4):
    • The width of the groove reduced from about 140 microns to about 30 microns.
    • Depth measurements were undeterminable.
      White Panel Cross-section Profile Analysis (FIGS. 5 and 6):
    • The width of the groove reduced from about 250 microns to about 160 microns.
    • The depth of the groove reduced from about 41 microns to about 36 microns.

The results demonstrate insignificant gloss changes to the area of the coated substrate surrounding the defect at a 95% confidence level.

EXAMPLE 3

Glossiness was evaluated for the scratched surfaces and the surfaces treated with the surface defect treatment composition of Example 1. Before any gloss measurements were taken, each panel was buffed with towels. Five measurements of gloss were taken at 60° for each scratch location and the average values before and after treatment with the composition described in Table 1 were used to determine the magnitude of gloss improvement.

Before use, the measuring unit was calibrated. The calibration cycle of three geometries is automatically performed. First the zero calibration is checked (dark calibration), then the gloss calibration for 20°, 60° and 85° is performed. Calibration is completed after approximately 10 seconds. The measuring unit is removed from the holder.

Five readings were taken at 60° on a 3 by 6-in (75 by 150-mm) area of the test specimen. The statistical capability of the BYK-Gardner GmbH micro-TRI-gloss; 20° 60° 85°″ instrument, cat. no. 4520, was used to obtain a mean value and standard deviation.

The procedures generally are described in ASTM D-523(-89) “Standard Test Method for Specular Gloss.” The standard deviation was calculated according to: s = √ ( 1 / n - 1 ) ⁢ ∑ i = 1 n ⁢ ( x i - x ) 2

Tables 5-7 below list the results of the glossiness measurements at each scratch location:

TABLE 5 BLACK COLOR PANEL Loca- tion Mean/ on Std Gloss before Treatment Gloss after Treatment Panel Dev (GU) (GU) 1 88.7, 88.6, 88.7, 88.6, 88.6 89.7, 89.7, 89.7, 89.7, 89.6 Mean 88.6 89.7 Std Dev  0.1  0.1 2 88.9, 88.9, 88.9, 88.9, 88.9 89.4, 89.5, 89.4, 89.4, 89.4 Mean 88.9 89.4 Std Dev  0.1  0.1 3 88.5, 88.4, 88.5, 88.6, 88.6 89.2, 89.3, 89.2, 89.2, 89.2 Mean 88.5 89.2 Std Dev  0.1  0.1 4 85.5, 85.5, 85.5, 85.5, 85.4 89.0, 89.1, 89.0, 89.0, 89.1 Mean 85.5 89.0 Std Dev  0.1  0.1 5 82.5, 82.6, 82.5, 82.5, 82.5 84.3, 84.3, 84.3, 84.2, 84.2 Mean 82.5 84.3 Std Dev  0.1  0.1 6 81.2, 81.1, 81.2, 81.1, 81.1 84.9, 84.9, 84.9, 84.8, 84.8 Mean 81.1 84.9 Std Dev  0.1  0.1 7 84.6, 84.7, 84.7, 84.7, 84.7 86.8, 86.9, 86.9, 86.9, 86.8 Mean 84.7 86.9 Std Dev  0.1  0.1 8 80.4, 80.5, 80.6, 80.6, 80.6 87.0, 86.8, 86.7, 86.7, 86.7 Mean 80.5 86.8 Std Dev  0.2  0.2 9 85.0, 85.0, 85.0, 84.8, 84.8 88.9, 89.0, 89.0, 89.0, 89.0 Mean 84.9 89.0 Std Dev  0.2  0.1 10 86.2, 86.1, 86.1, 86.1, 86.1 86.9, 86.8, 86.7, 86.7, 86.7 Mean 86.1 86.8 Std Dev  0.1  0.2

TABLE 6 RED COLOR PANEL Loca- tion Mean/ on Std Gloss before Treatment Gloss after Treatment Panel Dev (GU) (GU) 1 80.4, 80.5, 80.4, 80.4, 80.4 85.6, 85.7, 85.8, 85.8, 85.8 Mean 80.4 85.7 Std Dev  0.1  0.2 2 79.9, 79.9, 79.8, 79.8, 79.8 86.9, 86.9, 86.9, 86.9, 86.9 Mean 79.8 86.9 Std Dev  0.1  0.1 3 80.7, 80.6, 80.7, 80.6, 80.6 84.1, 84.3, 84.3, 84.3, 84.3 Mean 80.6 84.3 Std Dev  0.1  0.2 4 67.6, 67.6, 67.5, 67.6, 67.6 87.2, 87.2, 87.3, 87.3, 87.3 Mean 67.6 87.3 Std Dev 1   0.1 5 79.1, 78.4, 78.8, 79.0, 79.1 84.5, 84.9, 84.8, 84.8, 84.8 Mean 78.9 84.8 Std Dev  0.2  0.2 6 83.6, 83.7, 83.7, 83.7, 83.7 86.6, 86.7, 86.7, 86.7, 86.7 Mean 83.7 86.7 Std Dev  0.1  0.1 7 81.2, 81.3, 81.3, 81.2, 81.2 84.6, 84.8, 84.7, 84.7, 84.7 Mean 81.2 84.7 Std Dev  0.1  0.1 8 74.3, 74.2, 74.3, 74.2, 74.3 86.0, 86.2, 86.0, 86.0, 85.9 Mean 74.3 86.0 Std Dev  0.1  0.2 9 78.7, 78.8, 78.8, 78.8, 78.7 89.2, 89.2, 89.2, 89.2, 89.1 Mean 78.8 89.2 Std Dev  0.1  0.1 10 83.5, 83.5, 83.5, 83.5, 83.5 86.6, 86.7, 86.7, 86.7, 86.6 Mean 83.5 86.7 Std Dev  0.1  0.1

TABLE 7 WHITE COLOR PANEL Loca- tion Mean/ on Std Gloss before Treatment Gloss after Treatment Panel Dev (GU) (GU) 1 83.0, 83.1, 83.1, 83.1, 83.1 90.0, 90.0, 90.1, 90.0, 90.0 Mean 83.1 90.0 Std Dev  0.1  0.1 2 73.7, 73.6, 73.6, 73.7, 73.6 89.0, 89.1, 89.1, 89.1, 89.0 Mean 73.6 89.1 Std Dev  0.1  0.1 3 68.7, 68.8, 68.9, 68.9, 68.9 89.7, 89.9, 90.0, 90.0, 90.0 Mean 68.8 89.9 Std Dev  0.2  0.2 4 72.1, 72.2, 72.3, 72.3, 72.4 87.2, 87.2, 87.1, 87.0, 87.0 Mean 72.3 87.1 Std Dev  0.2  0.2 5 70.9, 71.0, 70.9, 70.9, 70.9 88.0, 88.2, 88.7, 88.7, 88.7 Mean 70.9 88.5 Std Dev  0.1  0.4 6 77.8, 77.3, 77.3, 77.3, 77.2 89.2, 89.3, 89.3, 89.3, 89.3 Mean 77.4 89.3 Std Dev  0.2  0.1 7 68.9, 68.9, 69.0, 69.0, 69.0 89.6, 89.7, 89.6, 89.5, 89.5 Mean 69.0 89.6 Std Dev  0.1  0.1 8 73.1, 73.1, 73.1, 73.2, 73.2 88.9, 88.8, 88.9, 88.9, 88.8 Mean 73.1 88.9 Std Dev  0.1  0.1 9 70.9, 71.0, 70.9, 71.0, 71.0 88.9, 89.1, 89.1, 89.0, 89.0 Mean 71.0 89.0 Std Dev  0.1  0.1 10 79.8, 79.9, 79.9, 79.9, 79.9 88.7, 88.8, 88.8, 88.9, 88.8 Mean 79.9 88.8 Std Dev  0.1  0.1

The above results indicate gloss improvement at each scratch location.

EXAMPLE 3

Tests were conducted on each panel to assess damage to surfaces surrounding each scratch after treatment with the composition described in Table 1. Base line gloss readings and after treatment gloss readings for all panels were accomplished in the same manner as described in Example 2. Again, before any gloss measurements were taken, the panels were buffed with a towel to take off dirt or contaminants.

Four randomly selected locations were chosen for each color panel, and the gloss measurements of both the treated and untreated panels were determined based on ASTM D 523(-89) “Standard Test Method for Specular Gloss.” Five measurements of gloss were taken at each location both prior to and following treatment with the composition. The average values before treatment and after treatment were used to determine the magnitude of gloss change at the areas surrounding the scratches.

Tables 8-10 below list the results of the glossiness measurements for the surrounding areas before and after treatment.

TABLE 8 Gloss Gloss Gloss Gloss Gloss Location Reading 1 Reading 2 Reading 3 Reading 4 Reading 5 Standard on Panel (GU) (GU) (GU) (GU) (GU) Mean Deviation Black Panel Before Treatment 1 89.1 89.1 89.0 88.9 88.9 89.0 0.2 2 89.8 89.7 89.7 89.9 89.9 89.8 0.2 3 88.7 88.7 88.7 88.7 88.7 88.7 0.1 4 88.1 87.9 87.5 87.5 87.5 87.7 0.2 Black Panel After Treatment 1 89.1 89.0 89.0 88.9 88.9 89.0 0.1 2 89.4 89.5 89.4 89.4 89.4 89.4 0.1 3 88.3 88.3 88.3 88.3 88.3 88.3 0.1 4 88.2 88.3 88.1 88.1 88.1 88.2 0.2

TABLE 9 Gloss Gloss Gloss Gloss Gloss Location Reading 1 Reading 2 Reading 3 Reading 4 Reading 5 Standard on Panel (GU) (GU) (GU) (GU) (GU) Mean Deviation Red Panel Before Treatment 1 88.8 88.8 88.8 88.8 88.6 88.8 0.2 2 88.2 88.1 88.1 88.1 88.1 88.1 0.1 3 88.3 88.5 88.5 88.5 88.6 88.5 0.2 4 87.6 87.7 87.6 87.6 87.6 87.6 0.1 Red Panel After Treatment 1 88.4 88.5 88.5 88.5 88.5 88.5 0.1 2 87.9 88.0 88.0 88.0 88.0 88.0 0.1 3 88.6 88.7 88.7 88.6 88.6 88.6 0.1 4 87.8 87.9 87.9 87.9 87.9 87.9 0.1

TABLE 10 Gloss Gloss Gloss Gloss Gloss Location Reading 1 Reading 2 Reading 3 Reading 4 Reading 5 Standard on Panel (GU) (GU) (GU) (GU) (GU) Mean Deviation White Panel Before Treatment 1 90.0 90.0 90.0 89.9 89.9 90.0 0.1 2 89.1 89.1 88.9 88.8 88.8 88.9 0.2 3 89.2 89.2 89.1 89.2 89.1 89.2 0.1 4 89.0 89.0 88.9 88.9 88.9 88.9 0.1 White Panel After Treatment 1 89.7 89.8 89.8 89.8 89.8 89.8 0.1 2 89.0 89.1 89.1 89.1 89.0 89.1 0.1 3 89.5 89.6 89.6 89.6 89.6 89.6 0.1 4 88.8 88.9 88.9 88.9 88.9 88.9 0.1

The above results indicate 95% confidence level that there were no significant gloss changes to the top coat surrounding the scratches.

EXAMPLE 4

A surface defect treatment composition was prepared substituting Abrasive MIR-100 as the abrasive in the formula shown in Table 1 and the panels were scratched and treated as described in Example 2. MIR-100 is an alpha alumina from Bernatex Corporation having an average particle size of 2.2 microns and a surface are of from 12 to 15 m2/g.

The surface defect treatment composition produced adequate visual results, but the scratch remained more visible using MIR-100 than using the same composition comprising MIR-100 3 Micron (Examples 1-3).

EXAMPLE 5

The formula shown in Table 1 was used substituting a variety of abrasives having larger particle sizes, as follows:

Particle Abrasive Material Supplier Chemistry Size Perlite Acrylux 1000 World Alpha Alumina (D10) 27 Minerals Microns World Amorphous Alumino- (D50) 64 Minerals silicate Microns World Amorphous Alumino- D(90) 121 Minerals silicate Microns Perlite Arylux 150 World Amorphous Alumino- (D10) 87 Minerals silicate Microns World Amorphous Alumino- (D50) 138 Minerals silicate Microns World Amorphous Alumino- (D90) 214 Minerals silicate Microns Perlite Harborlite World Amorphous Alumino- Median 17.0 Minerals silicate Microns

The formulas all produced a substantial amount of damage to the surrounding surface of the coating, indicating that the abrasive was too aggressive for efficient use.

As will be understood by those of skill in the art, and others, additional ingredients and components can also be included within the composition of this application. The above discussion illustrates some embodiments of the composition, but is not intended to limit the scope of possible formulations of the composition. The embodiments described herein are meant to be illustrative only and should not be taken as limiting the invention, which is defined in the following claims.

Claims

1. A surface defect treatment composition for repairing defects in coated substrates comprising:

abrasive consisting essentially of inorganic particles having an average particle size of from about 0.1 to about 12.0 microns and a surface area of from about 6 to about 17 m2/g; and,
an emulsion comprising one or more organopolysiloxanes.

2. The surface defect treatment composition of claim 1 wherein the organopolysiloxanes are branched or linear organopolysiloxanes comprising groups having the following formula [RaSiO(4−a)/2]n wherein:

R is a radical independently selected from the group consisting of monovalent hydrocarbon radicals, hydroxy radicals, and hydrocarbonoxy radicals having from 1 to 18 carbon atoms, said radicals being unsubstituted or comprising a substituent selected from the group consisting of amino, mercapto, olefinic, and aromatic groups;
a is on average from 0.7 to 2.6 per unit of the organopolysiloxane, and
n is from 10 to 10,000.

3. The surface defect treatment composition of claim 2 wherein the organopolysiloxane comprises repeating units having the following structure: wherein R1 and R2 individually are selected from the group consisting of: phenyl groups; unsubstituted and substituted alkyl groups having from about 1 to 18 carbon atoms, optionally comprising one or more substituent selected from the group consisting of amino groups, aminoalkyl groups and salts thereof, and groups comprising one or more unsaturated carbon-carbon bond.

4. The surface defect treatment composition of claim 3 wherein the organopolysiloxane comprises one or more substituent selected from the group consisting of C1-8 alkoxy groups, trialkylsilyl groups, dialkylsilanolyl groups, dialkylalkoxysilyl groups, alkyldialkoxysilyl groups, and dialkylvinylsilyl groups.

5. The surface defect treatment composition of claim 1 wherein the organopolysiloxane has a viscosity of from about 10 to about 60,000 cSt.

6. The surface defect treatment composition of claim 1 wherein the organopolysiloxane has a viscosity of from about 100 to about 3,000 cSt.

7. The surface defect treatment composition of claim 1 wherein the organopolysiloxane has a viscosity of from about 300 to about 500 cSt.

8. The surface defect treatment composition of claim 1 wherein the organopolysiloxane is polydimethylsiloxane.

9. The surface defect treatment composition of claim 7 wherein the organopolysiloxane is polydimethylsiloxane.

10. The surface defect treatment composition of claim 1 wherein the inorganic particles have an average particle size of from about 2.0 to about 5 microns and a surface area of from about 6 to about 15 m2/g.

11. The surface defect treatment composition of claim 1 wherein the inorganic particles have an average particle size of from about 2.0 to about 5 microns and a surface area of from about 6 to about 11 m2/g.

12. The surface defect treatment composition of claim 1 wherein the inorganic particles have an average particle size of from about 2.0 to about 5 microns and a surface area of from about 8 to about 11 m2/g.

13. The surface defect treatment composition of claim 7 wherein the inorganic particles have an average particle size of from about 2.0 to about 3.2 microns and a surface area of from about 8 to about 11 m2/g.

14. The surface defect treatment composition of claim 9 wherein the inorganic particles have an average particle size of from about 2.0 to about 3.2 microns and a surface area of from about 8 to about 11 m2/g.

15. A surface defect treatment composition for repairing defects in coated substrates comprising:

abrasive consisting essentially of inorganic particles having an average particle size of from about 0.1 to about 12.0 microns and a surface area of from about 6 to about 17 m2/g;
an emulsion comprising one or more organopolysiloxanes having a viscosity of from about 100 to about 3,000 cSt; and,
a quantity of thickener comprising hydrophilic non-ionic water soluble polymer sufficient to produce a dynamic viscosity of from about 20,000 cP to about 50,000 cP.

16. The surface defect treatment composition of claim 15 wherein the organopolysiloxane has a viscosity of from about 300 to about 500 cSt.

17. The surface defect treatment composition of claim 15 wherein the organopolysiloxane is polydimethylsiloxane.

18. The surface defect treatment composition of claim 15 wherein the thickener comprises water soluble cellulose ether.

19. The surface defect treatment composition of claim 16 wherein the thickener comprises water soluble cellulose ether.

20. The surface defect treatment composition of claim 17 wherein the thickener comprises hydroxyethyl cellulose.

21. The surface defect treatment composition of claim 19 wherein the inorganic particles have an average particle size of from about 2.0 to about 5 microns and a surface area of from about 6 to about 15 m2/g.

22. The surface defect treatment composition of claim 19 wherein the inorganic particles have an average particle size of from about 2.0 to about 5 microns and a surface area of from about 6 to about 11 m2/g.

23. The surface defect treatment composition of claim 19 wherein the inorganic particles have an average particle size of from about 2.0 to about 5 microns and a surface area of from about 8 to about 11 m2/g.

24. A surface defect treatment composition for repairing defects in coated substrates comprising:

abrasive consisting essentially of inorganic particles having an average particle size of from about 2.0 to about 3.2 microns and a surface area of from about 8 to about 11 m2/g;
an emulsion comprising one or more organopolysiloxanes having a viscosity of from about 300 to about 500 cSt; and,
a quantity of thickener comprising hydrophilic non-ionic water soluble polymer sufficient to produce a dynamic viscosity of from about 20,000 cP to about 50,000 cP.

25. The surface defect treatment composition of claim 25 wherein the organopolysiloxane is polydimethylsiloxane.

26. The surface defect treatment composition of claim 26 wherein the thickener comprises hydroxyethyl cellulose.

27. The surface defect treatment composition of claim 24 wherein the inorganic particles having an average particle size of about 3 microns.

28. The surface defect treatment composition of claim 25 wherein the inorganic particles having an average particle size of about 3 microns.

29. The surface defect treatment composition of claim 27 wherein the inorganic particles comprise alpha alumina.

30. The surface defect treatment composition of claim 28 wherein the inorganic particles comprise alpha alumina.

31. The surface defect treatment composition of claim 27 further comprising:

from about 1.0 wt. % to about 1.6 wt. % hydroxyethylcellulose;
from about 0.06% to about 0.10 wt. % of preservative comprising one or more of 5-chloro-2-methyl-4-isothiazolin-3-one and 2-methyl-4-isothiazolin-3-one; and,
from about 3 wt. % to about 7 wt. % glycerin.

32. The surface defect treatment composition of claim 30 further comprising:

from about 1.0 wt. % to about 1.6 wt. % hydroxyethylcellulose;
from about 0.06% to about 0.10 wt. % of preservative comprising one or more of 5-chloro-2-methyl-4-isothiazolin-3-one and 2-methyl-4-isothiazolin-3-one; and,
from about 3 wt. % to about 7 wt. % glycerin.
Patent History
Publication number: 20070119103
Type: Application
Filed: Oct 30, 2006
Publication Date: May 31, 2007
Inventor: Tsao-Chin HUANG (Katy, TX)
Application Number: 11/554,491
Classifications
Current U.S. Class: 51/298.000; 51/307.000; 51/303.000; 51/309.000
International Classification: B24D 3/02 (20060101);