Modified epoxy resins, processes for making and using same and substrates coated therewith

A polymeric blend that is dispersible in a basic aqueous vehicle, and that has an oxirane content of no more than 3%, that is the reaction product of:

• (a) from about 10 to about 90% by weight of said blend of an aromatic 1,2-epoxy resin consisting of a glycidyl ether of polynuclear polyhydric phenol that has an average molecular weight of from about 350 to about 20,000 and aliphatic backbone carbon chains,
• (b) from about 10% to about 90% by weight of said blend of addition polymerizable monomer containing ethylenic unsaturation and comprising an acrylic acid,
• reacted in the presence of at least 3% by weight of benzoyl peroxide by weight based on said monomer, at a temperature in the range from about 110.degree. C. to about 130.degree., or under equivalent free radical initiating conditions for the reaction using a peroxide initiator, to effect the simultaneous addition polymerization of the monomer through its ethylenic unsaturation and to produce an acid-functional reaction product composition that comprises a graft polymer of addition polymer grafted on the epoxy resin to the extent of at least about 11/2 weight parts of said addition polymer component per 100 weight parts of said epoxy resin equivalent in the blend, the graft polymer being characterized by the substantial absence of hydrolyzable functional groups other than terminal epoxy groups,
• the acid-functionality of the reaction product composition being sufficiently high to establish the reaction product as a dispersion in an aqueous medium containing a base that ionizes the acid-functional polymers.

A polymeric blend that is dispersible in a basic aqueous vehicle and that has an oxirane oxygen content of no more than 3%, that is the reaction product of:

• (a) from about 60 parts to about 90 parts by weight of an aromatic 1,2-epoxy diepoxide resin consisting of a diglycidyl ether of a polynuclear polyhydric phenol, that has a molecular weight in the range from about 4,000 to about 10,000 and that has aliphatic backbone carbon chains, and
• (b) from about 10 to about 40 parts by weight of a mixture of addition polymerizable monomers comprising a major amount of an acrylic acid and a minor amount of styrene, the quantity of the acrylic acid being sufficient to impart to the blend an Acid Number of from 80 to 90;
• the addition polymerization of said monomer mixture being conducted in the presence of said epoxy resin and in the presence of benzoyl peroxide at from about 110.degree. C. to about 130.degree. C., in an amount of at least 3% by weight based on the weight of the monomer, or under equivalent free radical initiating conditions for the reaction using a peroxide initiator, simultaneously to effect the addition polymerization of the monomer through its ethylenic unsaturation and to produce an acid-functional reaction product composition that comprises a graft polymer of addition copolymer on the epoxy resin that is characterized by the substantial absence of hydrolyzable functional groups other than terminal epoxy groups,
• the addition copolymer being grafted onto aliphatic backbone carbon atoms of the initial epoxy resin that have either one or two hydrogens bonded thereto in the ungrafted state, to the extent of at least about 11/2 weight parts of said addition polymer component per 100 weight parts of said epoxy resin equivalent in the blend,
• said reaction product also including associatively-formed, ungrafted addition copolymer in addition to ungrafted initial epoxy resin,
• said graft polymer and said ungrafted addition copolymer being acid-functional, the acid-functionality of the reaction product composition being sufficiently high to establish and to maintain the product composition as a dispersion in an aqueous medium containing a base that ionizes the acid-functional polymers.

A coating composition comprising a dispersion in an aqueous vehicle which comprises a major amount of water and a minor amount of water-miscible organic solvent material of a blend of film-forming polymeric constituents, together with a base that is fugitive under curing conditions for the coating, wherein the polymeric blend is an associatively-formed mixture having an oxirane oxygen content of no more than 3% of:

• (a) carboxylic acid-functional graft polymer,
• (b) carboxylic acid-functional addition copolymer, and
• (c) ungrafted aromatic 1,2-epoxy diepoxide resin consisting of a glycidyl ether of a polynuclear polyhydric phenol;
• said graft polymer being an aromatic 1,2-epoxy diepoxide resin component in its ungrafted state consisting of a glycidyl ether of a polynuclear polyhydric phenol, having a molecular weight of from about 350 to about 20,000 and having aliphatic backbone carbon chains onto which is grafted at aliphatic backbone carbons thereof carboxylic acid-functional addition copolymer comprising addition copolymerized units of an acrylic acid and of a styrenic monomer, to the extent of at least about 21/2 weight parts of said addition polymer component per 100 weight parts of said epoxy resin equivalent in the blend, which acid furnishes carboxyl groups that consitute at least 5% by weight of said blend, said graft polymer being formed by the reaction of a 1,2-epoxy diepoxide resin and ethylenically unsaturated monomer in the presence of at least 3% of benzoyl peroxide by weight based on monomer, or under equivalent free radical initiating conditions for the reaction including the use of a peroxide initiator, at a temperature in the range from about 80.degree. C. to 200.degree. C.,
• the epoxy resin component of said graft polymer and the ungrafted epoxy resin together constituting at least about 10 and up to 90% by weight of said blend by weight,
• the Acid Number of said blend being in the range from about 45 to about 150,
• the acid functional polymers being ionized by said base, the ionization of the acid-functional polymers being sufficient to establish and to maintain the dispersion of the blend in the aqueous vehicle.

A coating composition comprising a dispersion in an aqueous vehicle which comprises a major amount of water and a minor amount of water-miscible organic solvent material of a blend of film-forming polymeric constituents together with a base that is fugitive under curing conditions for the coating, wherein the polymeric blend is an associatively-formed mixture formed by reacting together an initial reaction mixture of from 50% to 90% by weight of an aromatic 1,2-epoxy diepoxide resin consisting of a glycidyl ether of a polynuclear polyhydric phenol that has aliphatic backbone carbon chains, and addition polymerizable monomer, in the presence of at least 4% by weight of the monomer of benzoyl peroxide at a temperature in the range from about 110.degree. C. to about 130.degree. C., or under equivalent peroxide-type initiation, said blend having an oxirane oxygen content of no more than 3% and comprising:

• (a) carboxylic acid-functional graft polymer,
• (b) ungrafted carboxylic acid-functional addition copolymer, and
• (c) ungrafted aromatic 1,2-epoxy diepoxide resin;
• said graft polymer having an aromatic 1,2-epoxy diepoxide resin component formed from the reaction of epichlorohydrin with bisphenol A and having aliphatic backbone carbon chains, the diepoxide resin having a molecular weight in the range from about 4,000 to about 10,000 and an oxirane oxygen content not substantially above about 8%, onto which epoxy resin component is grafted at aliphatic backbone carbons thereof to the extent of at least about 21/2 weight parts of said addition polymer component per 100 weight parts of said epoxy resin equivalent in the blend, an addition copolymer component formed from copolymerized units of methacrylic acid and of styrene in the relative ratios to each other of from 60 to 39, to about 80 to 19.5, the methacrylic acid furnishing carboxyl units consisting at least 5% by weight of said blend,
• the Acid Number of said blend being in the range from about 80 to about 90,
• the acid-functional polymers being ionized by said base, the ionization of the acid-functional polymers being sufficient to establish and to maintain the blend dispersed in the aqueous vehicle.

A water-based coating composition comprising, in percentage by weight of the composition,

• (a) from about 60% to about 90% of a liquid vehicle and
• (b) from about 10% to about 40% by weight of the composition of solids;
• said solids comprising a blend of film-forming polymeric constituents having an oxirane content of no more than 3%, and being an associatively-formed mixture of:
• (a) carboxylic acid-functional graft polymer,
• (b) carboxylic acid-functional addition copolymer, and
• (c) ungrafted aromatic 1,2-epoxy diepoxide resin consisting of a glycidyl ether of a polynuclear polyhydric phenol;
• said graft polymer being an aromatic 1,2-epoxy diepoxide resin component in its ungrafted state consisting of a glycidyl ether of a polynuclear polyhydric phenol having a molecular weight of from about 4,000 to about 10,000 and having aliphatic backbone carbons onto which is grafted at aliphatic backbone carbons thereof carboxylic acid-functional addition copolymer component to the extent of at least about 21/2 weight parts of said addition polymer component per 100 weight parts of said epoxy resin equivalent in the blend, said copolymer component comprising copolymerized untis of an acrylic acid and of a second ethylenically unsaturated monomer, which acid furnishes carboxyl groups that constitute at least 5% by weight of said blend, said graft polymer being formed by the reaction of a 1,2-epoxy diepoxide resin and ethylenically unsaturated monomer in the presence of at least 3% of benzoyl peroxide by weight based on monomer, or under equivalent free radical initiating conditions for the reaction including the use of a peroxide initiator, at a temperature in the range from about 110.degree. C. to 130.degree. C.,
• the epoxy resin component of said graft polymer and the ungrafted epoxy resin together constituting from 50% to 90% of said blend by weight, the Acid Number of said blend being in the range from about 30 to about 220, on a solids basis,
• said solids comprising from 6% to 39.9% of said blend and from 0.1% to 16% of a cross-linking resin;
• said liquid vehicle consisting of from 6% to 35% by weight of the composition of organic solvent, and from 25% to 80% of water, together with a sufficient quantity of a base that is fugitive at curing temperature for the composition to ionize the acid-functional polymers, the ionization being sufficient to establish the blend in the aqueous vehicle as a dispersion.

A water-based, sprayable coating composition for use for application as an internal sanitary liner for metal containers for beverages, comprising in percentages by weight of the composition,

• (a) from about 60% to about 90% of a liquid vehicle,
• (b) from about 9% to 29% of acidic resinous reaction product solids dispersed in the vehicle,
• (c) from about 1% to 10% of an added cross-linking agent, and
• (d) from about 2% to about 6% of a fugitive base that ionizes the resinous reaction product;
• said resinous reaction product being prepared by reacting together an initial reaction mixture of from 60% to 90% by weight of an aromatic 1,2-epoxy diepoxide resin consisting of a glycidyl ether of a polynuclear polyhydric phenol that has a molecular weight from about 4,000 to about 10,000, and ethylenically unsaturated addition polymerizable monomer comprising an acrylic acid, and benzoyl peroxide at a temperature from 110.degree. C. to about 130.degree. C. in an amount of at least 3% by weight based on the weight of the monomer, or under equivalent free radical initiating conditions for the reaction using a peroxide initiator, simultaneously to initiate the addition polymerization of said monomer through its ethylenic unsaturation and to produce an acidic graft polymer of addition polymer grafted to the epoxy resin that is characterized by the substantial absence of hydrolyzable functional groups other than terminal epoxy groups on the epoxy resin component of the graft polymer, the grafting being to the extent of at least about 21/2 weight parts of said addition polymer component per 100 weight parts of said epoxy resin equivalent in the blend, the acrylic acid being present in the initial reaction mixture in sufficient quantity to impart an Acid Number to the resinous reaction product in the range from about 80 to about 90;
• said liquid vehicle consisting of water and up to 35% by weight of the coating composition of organic solvent,
• the ionization being sufficient to establish the solids in the liquid vehicle in dispersed form.

A process for producing a water-reducible curable sanitary coating composition which comprises:

• reacting together an aromatic diepoxide wherein the epoxide groups are 1,2-epoxy groups and addition polymerizable monomers containing ethylenic unsaturation and comprising an acrylic acid,
• said acrylic acid comprising a proportion of said monomers of from 10% to 80% by weight thereof,
• said epoxy resin having a molecular weight of from about 4,000 to 10,000 and providing from 50% to 90% of the initial reaction mixture,
• in the presence of benzoyl peroxide at a temperature between about 110.degree. C. and 130.degree. C. in an amount of at least 3% by weight based on the weight of monomer, or under equivalent free radical initiating conditions for the reaction using a peroxide initiator, simultaneously to effect addition polymerization of the monomer through its ethylenic unsaturation, and to produce a resinous reaction product comprising a graft polymer of addition polymer on the diepoxide that is characterized by the substantial absence of hydrolyzable functional groups other than terminal epoxy groups, and
• thereafter dispersing the resinous reaction product in water with a base that is fugitive under curing conditions for the coating.

A process for modifying a 1,2-epoxy resin with addition polymerizable monomer, to form a water-dispersible reaction product, comprising reacting together:

• (a) an aromatic 1,2-epoxy diepoxide resin consisting of a glycidyl ether of a polynuclear polyhydric phenol that has aliphatic backbone carbons, and that has a molecular weight in the range from about 4,000 to about 10,000 and
• (b) addition polymerizable monomer containing ethylenic unsaturation and comprising an unsaturated carboxylic acid;
• the epoxy resin constituting at least 60% by weight of the solids of the reaction mixture and up to 90% by weight thereof;
• in the presence of benzoyl peroxide at an elevated temperature from 110.degree. C. to 120.degree. C. in an amount of at least 3% by weight based on the weight of monomer, or under equivalent free radical initiating conditions for the reaction using a peroxide initiator, to effect simultaneous addition polymerization of the monomer through its ethylenic unsaturation and to promote graft formation and grafting at aliphatic backbone carbon atoms of the epoxy resin that have either one or two hydrogens in the ungrafted state, to form graft polymer with addition polymer grafted to such aliphatic backbone carbons of the epoxy resin to the extent of at least about 21/2 weight parts of said addition polymer component per 100 weight parts of said epoxy resin equivalent in the blend, and with ionizable carboxyl groups constituting at least 5% by weight of the reaction product solids, the acid functionality of the reaction product composition being sufficiently high to establish the product composition as a dispersion in an aqueous medium containing a base that ionizes the acid-functional composition, the product having an oxirane content of no more than 3%.

A process for preparing a curable resinous composition having an oxirane content of no more than 3% that is useful as a binder in a coating composition comprising reacting together a momomer mixture consisting of a major amount of methacrylic acid, a minor amount of styrene, and a lesser amount of a lower alkyl ester of acrylic acid or methacrylic acid, in the presence of an aromatic 1,2-epoxy diepoxide resin consisting of a glycidyl ether of a polynuclear polyhydric phenol, that has aliphatic backbone carbons, that furnishes a major portion and up to 90% of the solids content of the reactants, and that has a molecular weight of from about 350 to about 20,000, in the presence of benzoyl peroxide at 110.degree. C. to 130.degree. C. in an amount of at least 3% by weight based on the weight of monomer, or under equivalent free radical initiating conditions for the reaction using a peroxide initiator, to effect the simultaneous addition polymerization of the monomer through its ethylenic unsaturation and to produce an acid-functional reaction product composition that comprises a graft polymer of addition polymer on the epoxy resin that is characterized by the substantial absence of hydrolyzable functional groups other than terminal epoxy groups, the acid functionality of the reaction product composition being sufficiently high to establish the reaction product composition as a dispersion in an aqueous medium that contains a base that ionizes the acid-functional composition.

A process for making a curable resinous composition having an oxirane content of no more than 3% that is useful as a binder in a coating composition comprising reacting together;

• (a) an aromatic 1,2-epoxy diepoxide resin that is a reaction product of epichlorohydrin and bisphenol A, that has an average molecular weight in the range from about 4,000 to about 10,000, and that has aliphatic backbone carbon chains, and
• (b) a mixture of monomers that contain ethylenic unsaturation and that are copolymerizable to form an addition polymer, said mixture consisting of a major amount of methacrylic acid, a minor amount of styrene, and a lesser amount of a lower alkyl ester of acrylic acid or methacrylic acid,
• the epoxy resin constituting at least 50% by weight of the solids of the reaction mixture and up to 90% by weight thereof,
• in the presence of benzoyl peroxide at a temperature in the range from about 110.degree. C. to about 130.degree. C. in an amount of at least 3% by weight based on the weight of monomer, or under equivalent free radical initiating conditions for the reaction using a peroxide initiator, simultaneously to effect addition polymerization of the monomer through its ethylenic unsaturation, and to promote graft formation and grafting at aliphatic backbone carbon atoms of the epoxy resin to form graft polymer with addition polymer grafted to such aliphatic backbone carbons of the epoxy resin;
• by gradually adding the monomer mixture to the diepoxide resin with mixing and while maintaining the mixture of the reaction above about 110.degree. C. up to about 130.degree. C. in the presence of the free radical initiator;
• the reaction being conducted in the presence of a water-miscible solvent system and
• recovering from the reaction an associatively-formed reaction product mixture of a graft polymer in which an addition copolymer component formed from the copolymerization of the ethylenically unsaturated monomers is grafted onto aliphatic backbone carbons of the diepoxide resin that have either one or two hydrogens bonded thereto in the ungrafted state, and associatively-formed ungrafted addition polymer formed by the copolymerization of the ethylenically unsaturated monomers, said reaction product mixture also including ungrafted diepoxide resin, and having on a non-volatiles basis an Acid Number of 45 to 150,
• the acid-functionality of the reaction product composition being sufficiently high to establish and to maintain the product composition as a dispersion in an aqueous medium that contains a base that ionizes the acid-functional reaction product.

A resinous blend reaction product that is dispersible in an aqueous ionizing medium, said blend comprising ionizable graft polymer substantially free from hydrolyzable functional groups other than terminal epoxy groups, ungrafted addition polymer, and ungrafted epoxy resin, said graft polymer having an epoxy resin component, the epoxy resin in its ungrafted state consisting of an aromatic or aliphatic 1,2-epoxy diepoxide resin having a molecular weight of from about 350 to about 20,000, said epoxy resin component having an aliphatic backbone carbon chain onto which is grafted an addition polymer side chain component comprising polymerized units of ethylenically unsaturated monomer, said graft polymer and said ungrafted addition polymer being ionizable by reason of the presence of ionizable units incorporated in each of the addition polymer side chain component and in the ungrafted addition polymer, the ionizability being sufficient for establishment of the reaction product as a dispersion in an aqueous medium containing an ionizing agent, said graft polymer being formed by the reaction of the 1,2-epoxy diepoxide resin and ethylenically unsaturated monomer in the presence of at least 3% of benzoyl peroxide by weight based on monomer, or under equivalent free radical initiating conditions for the reaction including the use of a peroxide initiator, at a temperature in the range from about 80.degree. C. to 200.degree. C.