Abstract: The present invention is directed to multireactivity polymercaptans, star-shaped copolymers and methods of preparing wherein the polymer comprises a polyvalent mercaptan core and three or more polymeric arms which extend radially from the core. The polyvalent mercaptan core comprises three or more thiol groups, wherein at least two of the thiol groups are of different reactivities, such that the core is of differential reactivity. These multifunctional thiols, which will be referred to as cores of differential reactivity, act as chain transfer agents in a free radical polymerization process.

Abstract: This invention relates to pressure sensitive adhesives, and processes of preparing such adhesives, comprising random star polymers which are crosslinked by reaction with multifunctional crosslinking agent. These adhesives can be used in coated articles.

Abstract: The present invention is directed to amphiphilic star polymers and their use as emulsion stabilizers in emulsion polymerization.

Abstract: Polylactide or polyglycolide graft copolymers, prepared with grafts comprising up to 40% by total polymer weight, but not 0%, of glycolide or the D- or L-isomer of lactide in an enantiomeric excess of 84% on a saturated polymer backbone, are suitable for use as the thermoplastic elastomeric component of hot melt adhesives.

Abstract: Polylactide or polyglycolide graft copolymers are prepared by a process comprising preparing a backbone polymer from acrylate and/or methacrylate monomers and from one or more polymerizable monomers that contain a functional group unreactive in a free-radical polymerization, the backbone polymer being compatible with lactide monomer or lactide polymer; adding to the resulting polymer up to 40% by total polymer weight, but not 0%, of the D- or L-isomer of lactide in an enantiomeric excess of 84%; heating the mixture of lactide and polymer to a temperature of 80.degree.-175.degree. C. in the presence of a tin catalyst for a period of time effective to polymerize the lactide and react the lactide with the functional group on the backbone polymer.

Abstract: Polyamide graft-modified rubbery block copolymer compositions are provided by reaction of maleated rubbery block copolymers with polymeric dimer fatty acid based polyamide wherein the molar ratio of maleated rubbery block copolymer to the dimer fatty acid polyamide is greater than 2 to 1. The compositions find use as hot melt adhesive components.

Abstract: A process for preparing methyl .alpha.-cyanoacrylate in which methyl cyanoacetate is reacted with formaldehyde to form a polymer, which is subsequently depolymerized to the monomeric product, comprises using an ester of poly(ethylene glycol) as the solvent for the polymerization and depolymerization reactions.

Abstract: Hot melt adhesive compositions are prepared from 20 to 98% by weight of a polylactide homo- or copolymer containing at least 20 molar percent of the lactide component; 2 to 80% by weight of a polar tackifier having a Ring and Ball softening point (as described by ASTM E-26) greater than about 60.degree. C.; 0 to 50% by weight of a plasticizer; 0 to 30% by weight of a wax diluent; 0-3% by weight of a stabilizer; and 0-20% of starch. By utilizing a naturally occurring, thermoplastic, biodegradable copolymer as the base polymer, these adhesives advance the state of the art of hot melt adhesives by alleviating the dependence on petroleum based materials and by allowing for the development of hot melt adhesives which either degrade naturally after coming in contact with the soil or which can be composted.

Abstract: Hot melt adhesive compositions are prepared from 20 to 98% by weight of a polylactide homo- or copolymer containing at least 20 molar percent of the lactide component; 2 to 80% by weight of a polar tackifier having a Ring and Ball softening point (as described by ASTM E-26) greater than about 60.degree. C.; 0 to 50% by weight of a plasticizer; 0 to 30% by weight of a wax diluent; 0-3% by weight of a stabilizer; and 0-20% of a polymer. By utilizing a naturally occurring, thermoplastic, biodegradable copolymer as the base polymer, these adhesives advance the state of the art of hot melt adhesives by alleviating the dependence on petroleum based materials and by allowing for the development of hot melt adhesives which either degrade naturally after coming in contact with the soil or which can be composted.

Abstract: A crosslinking additive for imparting water resistance to starch-based alkaline corrugating adhesive compositions is prepared by reacting acetone and formaldehyde under aqueous alkaline conditions at 20.degree.-80.degree. C. in a molar ratio of from 2 to 5 moles of formaldehyde per mole of acetone. The condensate is thereafter treated with from 1.0 to 2.0 moles of hydrogen peroxide per mole of unreacted formaldehyde which oxidizes the residual formaldehyde to formic acid. The treated crosslinking additive will contain less than 0.4% unreacted formaldehyde and may be added directly to a starch-based corrugating adhesive.

Abstract: A carbinol-containing polyimide oligomer terminated with epoxide-reactive end groups has the structure ##STR1## wherein Ar is ##STR2## R.sup.1 and R.sup.2 are independently divalent organic radicals; R.sup.3 is a trivalent organic radical; Y is an epoxide-reactive group (e.g.); m is 0 or 1 and n is 0-10. Suitable epoxide-reactive groups include a phenol, thiol, amine, or carboxyl group. Polyimide-polyepoxide adducts are prepared by reacting the polyimides with a polyepoxide, preferably a diepoxide used in excess. The polyimide oligomers are useful as coatings or adhesives. The adducts are useful as adhesives, for composites, and particularly for impregnating the fiberglass sheets which are used to form circuit boards.

Abstract: This invention presents improved epoxy-based die attach adhesives which are of low viscosity, high ionic purity, and stable toward thermal cycling. This improvement is obtained by including in the formulation carboxy terminated polymers which are the reaction products of polyether diols with cyclic dianhydrides.

Abstract: A carbinol-containing polyimide oligomer terminated with epoxide-reactive end groups has the structure ##STR1## wherein Ar is ##STR2## R.sup.1 and R.sup.2 are independently divalent organic radicals; R.sup.3 is a trivalent organic radical; Y is an epoxide-reactive group; m is 0 or 1 and n is 0-10. Suitable epoxide-reactive groups include a phenol, thiol, amine, or carboxyl group. Polyimide-polyepoxide adducts are prepared by reacting the polyimides with a polyepoxide, preferably a diepoxide used in excess. The polyimide oligomers are useful as coatings or adhesives. The adducts are useful as adhesives, for composites, and particularly for impregnating the fiberglass sheets which are used to form circuit boards.

Abstract: A hot-melt adhesive especially useful in the construction of disposable diapers contains a vinyl polymer of 40-90% by weight of a C.sub.1 -C.sub.12 alkyl acrylate and 10-60% by weight of an alpha-olefin of C.sub.20 -C.sub.40, wherein the alkyl acrylate may be partially replaced with vinyl acetate or with a C.sub.6 -C.sub.12 olefin or with mixtures thereof, provided that the polymer contain at least 10% by weight of the alkyl acrylate. The adhesive may also contain a tackifying resin, a wax, an oil or a stabilizer depending on the specific end-use desired. In a preferred embodiment the polymer contains 20-45% by weight of the alpha-olefin.

Abstract: A hot-melt adhesive especially useful in the construction of disposable diapers contains a vinyl polymer of 40-90% by weight of a C.sub.1 -C.sub.12 alkyl acrylate and 10-60% by weight of an alpha-olefin of C.sub.20 -C.sub.40, wherein the alkyl acrylate may be partially replaced with vinyl acetate or with a C.sub.6 -C.sub.12 olefin or with mixtures thereof, provided that the polymer contain at least 10% by weight of the alkyl acrylate. The adhesive may also contain a tackifying resin, a wax, an oil or a stabilizer depending on the specific end-use desired. In a preferred embodiment the polymer contains 20-45% by weight of the alpha-olefin.

Abstract: Novel polyimides, optionally end-capped with polymerizable or inert groups, and the polyamic acid or ester intermediates thereof are prepared by reacting a tetracarboxylic acid compound (e.g. pyromellitic dianhydride or 3,3',4,4'-benzophenone tetracarboxylic acid dianhydride or its methyl diester) with diamines having the general formula ##STR1## wherein Z is oxygen or sulfur, X and/or Y are carbonyl or carbinol groups, the amine groups may be in the 2-, 3-, and/or 4-position, and isomerism is present when X and/or Y is a carbinol group. The polyimides may be end-capped by reaction, during or after their formation, with polymerizable groups such as 3-aminophenyl acetylene or 3,6-endomethylene-1,2,3,6-tetrahydrophthalic anhydride. The diamines are novel classes of amines when Z is sulfur and X and/or Y are carbonyl or carbinol groups and when Z is oxygen and X, Y, or X and Y are carbinol groups.

Abstract: Novel carbinol-containing polyimides capable of self-crosslinking at low temperatures are prepared by reacting a molar excess of selected 3,3',4,4'-benzhydrol tetracarboxylic acid compounds (the tetraacid, diester-diacid, or (dianhydride) with polyfunctional polyamines (e.g. 4,4'-methylenedianiline, 1,6-hexanediamine, etc.) in an inert organic solvent at about 100.degree.-150.degree. C. The molar ratio of tetracarboxylic acid compound to diamine must be between 2:1 and 9:8. The polyimides may be crosslinked at less than 200.degree. C. via a reaction between the carbinol group(s) and the end group(s) of the polyimide.

Abstract: Novel polyimides, optionally end-capped with polymerizable or inert groups, and the polyamic acid or ester intermediates thereof are prepared by reacting a tetracarboxylic acid compound (e.g. pyromellitic dianhydride or 3,3',4,4'-benzophenone tetracarboxylic acid dianhydride or its methyl diester) with diamines having the general formula ##STR1## wherein Z is oxygen or sulfur, X and/or Y are carbonyl or carbinol groups, the amine groups may be in the 2-, 3-, and/or 4-position, and isomerism is present when X and/or Y is a carbinol group. The polyimides may be end-capped by reaction, during or after their formation, with polymerizable groups such as 3-aminophenyl acetylene or 3,6-endomethylene-1,2,3,6-tetrahydrophthalic anhydride. The diamines are novel classes of amines when Z is sulfur and when Z is oxygen and X, Y, or X and Y are carbinol groups.

Abstract: A N-substituted piperazine or N-substituted homopiperazine adduct with a polyepoxide is used as a co-curing agent in epoxy resin systems containing a polyepoxide and a known curing agent such as dicyandiamide, a carboxylic acid anhydride, or a dihydrazide. The preferred adducts have a ratio of epoxy groups to secondary amino groups of between 1.2:1 and 3:1. The preferred polyepoxides are polyglycidyl ethers of 4,4'-isopropylidenediphenol (bisphenol A). Suitable adducts are prepared from N-methyl-, N-(2-hydroxyethyl)-, N-octyl-, N-phenyl- and N-benzyl piperazine and N-methyl homopiperazine.

Abstract: An adhesive composition based on 2-cyanoacrylate esters contains as an anionic polymerization inhibitor an acid chelate formed of boric acid or a derivative thereof and a selected polyhydroxy compound. The chelate is conveniently formed in situ in the 2-cyanoacrylate ester, but may also be prepared separately and added to the ester directly. An exemplary acid chelate used as stabilizer is prepared from boric acid and pyrogallol. The resulting stabilized adhesive compositions have a rapid cure rate and may be used on a wide variety of substrates.