Abstract: Acyl-ethyleneurea terminated compounds based on the reaction of ethyleneurea with dibasic acids or methyl esters of dibasic acids or cyclic anhydrides are useful as modifying agents, cure accelerators and blocking agents with tertiary amine catalysts for epoxy resins. As epoxy modifiers, they react with epoxy resins at 120 degrees C. without a catalyst to produce modified epoxies having increased viscosity and increased reactivity and solvent power. When combined with a suitable tertiary amine catalyst, they are useful as cure accelerators at a low cure temperature of about 80 degrees C. When combined with a tertiary amine, they form complexes which provide superior latency of the epoxy-hardener mixture at 20 degrees C. Heat-curable epoxy-based compositions treated with the materials of the invention and processes whereby the various novel compositions of the invention are made, are also described.

Abstract: An epoxy-hardener system is provided having relatively long latency periods combined with relatively short cure times at low cure temperatures. The hardeners of the present invention are ureidoamines and their derivatives, which are chelates of ureido compounds and amines. The ureidoamines are prepared by reacting an amine with the ureido compound and aqueous formaldehyde without a catalyst. Complexes of ureidoamine hardeners with various blocking agents are prepared in the melt. The hardener is prevented from curing the epoxy by the reaction between the hardener and the blocking agent. The blocked hardener is then blended with the epoxy, usually by warming the mixture briefly at about 50-60 degrees C.

Abstract: Acyl-ethyleneurea terminated compounds or similar materials suitable for use as a blocking or modifying agent for improving the latency of a mixture of a hardener and a modified epoxy resin composition having increased hydroxy concentration. The compounds or materials of the invention are prepared in accordance with a preferred process by heating a dibasic acid with ethyleneurea in the presence of a basic catalyst. Alternatively, methyl esters or anhydrides of dibasic acids may be used instead of dibasic acids. Curable epoxy-based compositions treated with the compounds or materials of the invention, and processes, whereby the various novel compositions of the invention are made, are also described.

Abstract: Hardeners are provided for curing epoxies at lower temperatures than currently available hardeners while retaining superior mechanical and thermal properties. A first component is selected from imidazole, dicyandiamide, or a mixture of polyamines and tertiary amines. A poiyol mixture is then selected. The first component is combined with the polyol mixture to form a hardener. The hardener is combined with epoxy resin and is cured. A method for selecting a hardener to yield an epoxy-hardener system with good properties after curing at a specified temperature and time includes selecting components for the hardener so the glass transition temperature of the cured epoxy-hardener system is not significantly lower than 45° C. above the cure temperature. The method includes steps for adjusting and controlling the ultimate glass transition temperature to maximize the mechanical properties of the epoxy-hardener system. The method regularly produces hardened epoxy systems having about 90% or more epoxy groups reactect.

Abstract: An epoxy resin hardener having a cure temperature of between about 60° C. and 100° C. comprises a mixture of: a) an imidazole or a trihydric compound having methylol groups at the 2- and 6-positions formed by reacting a 4-alkylphenol with 2 moles of formaldehyde, b) trimethylopropane, and c) tetramethylguanidine or a tetramethylguanidine derived from the reaction of a monepoxide, a diepoxide, a phenol and formaldehyde, or a dihydric phenol and formaldehyde.

Abstract: Hardeners for epoxy resins having the capability of curing epoxies at lower temperatures than currently available hardeners while retaining superior mechanical and thermal properties. The hardeners are formed by selecting methylol and phenolic polyols, polyamines and tertiary amines. A method for selecting a hardener to yield a hardened epoxy system with good properties after curing at a specified temperature and time includes selecting components for the hardener so that the glass transition temperature of the cured epoxy-hardener system is not significantly lower than 45° C. above the cure temperature. The method includes steps for adjusting and controlling the ultimate glass transition temperature to maximize the mechanical properties of the hardened epoxy system. The method regularly produces hardened epoxy systems having about 90% or more epoxy groups reacted.

Abstract: A ball-throwing machine is provided which may be used for throwing baseballs, softballs and the like. The machine includes a power head having at least two and preferably three coacting wheels for propelling a ball toward a batter to simulate a pitch. Three AC motors and companion motor drives are provided for causing the wheels to rotate at predetermined speeds. The motor drives include dynamic braking circuits to permit rapid deceleration of the wheels. A pair of linear actuators is provided to permit the power head to be moved to predetermined horizontal and vertical positions. A programmable controller is included for individually controlling the rotational speed of each individual wheel, the horizontal position of the power head and the vertical position of the power head. A smart card reader may be employed for programming of the controller and the machine is adapted to be used in conjunction with a video display to simulate the actual pitching of a baseball by a pitcher.

Abstract: Hardeners for epoxy resins are disclosed which have the capability of curing at lower temperatures than currently available hardeners while retaining superior mechanical and thermal properties. These novel hardeners include a range of reactivity which results in a range of pot lives from minutes to months. These materials co-cure readily with polyamines and have little or no amine odor. Mixture viscosity can be controlled over a wide range independent of filler concentration which allows a broad range of applications from coating and casting to adhesives. Class I hardeners contain a mixture of polyols, polyamines and tertiary amines and cure at temperatures between 20-50° C., while class II hardeners have the same polyols mixed with one or more tertiary amines and cure between 65-100° C. Class III hardeners contain the same polyols combined with either imadazole or dicyandiamide, and optionally, a tertiary amine and cure at 120° C.

Abstract: Hardeners for epoxy resins are disclosed which have the capability of curing at lower temperatures than currently available hardeners while retaining superior mechanical and thermal properties. An especially useful hardener combines imidazole, tetramethylguanidine or tetramethylguanidine adduct, and trimethylolpropane to produce a hardener having a latency period of up to about 24 hours and which cures at temperatures as low as about 60° C. A second hardener mixture is composed of 2, 6-bis(hydroxymethyl)-p-cresol, tetramethylguanidine and trimethylolpropane. Accelerators and other materials are added as needed to modify the cure time and temperature to suit particular applications. A method for making the hardener is also disclosed.

Abstract: A ball-throwing machine is provided which may be used for throwing baseballs, softballs and the like. The machine includes a power head having at least two and preferably three coacting wheels for propelling a ball toward a batter to simulate a pitch. Three AC motors and companion motor drives are provided for causing the wheels to rotate at predetermined speeds. The motor drives include dynamic braking circuits to permit rapid deceleration of the wheels. A pair of linear actuators is provided to permit the power head to be moved to predetermined horizontal and vertical positions. A programmable controller is included for individually controlling the rotational speed of each individual wheel, the horizontal position of the power head and the vertical position of the power head. A smart card reader may be employed for programming of the controller and the machine is adapted to be used in conjunction with a video display to simulate the actual pitching of a baseball by a pitcher.

Abstract: A ball-throwing machine is provided which may be used for throwing baseballs, softballs and the like. The machine includes a power head having at least two and preferably three coacting wheels for propelling a ball toward a batter to simulate a pitch. Three AC motors and companion motor drives are provided for causing the wheels to rotate at predetermined speeds. The motor drives include dynamic braking circuits to permit rapid deceleration of the wheels. A pair of linear actuators is provided to permit the power head to be moved to predetermined horizontal and vertical positions. A programmable controller is included for individually controlling the rotational speed of each individual wheel, the horizontal position of the power head and the vertical position of the power head. A smart card reader may be employed for programming of the controller and the machine is adapted to be used in conjunction with a video display to simulate the actual pitching of a baseball by a pitcher.