Branched low profile additives and methods of production
The invention pertains to low profile additives (“LPA”) comprising branched polymers having a weight average molecular weight (Mw) of at least about 20,000 grams/mole and a number average molecular weight (Mn) of at least about 3,000 grams/mole and methods for making the LPAs. The invention further concerns compositions comprising LPAs synthesized from one or more difunctional monomers and one or more branching agents. Also, disclosed are thermosettable resinous compositions and molded articles comprising the LPAs.
1 . A low profile additive comprising a branched polyester resin wherein the low profile additive has a weight average molecular weight (Mw) of at least about 20,000 grams/mol and a number average molecular weight (Mn) of at least about 3,000 grams/mol.
2 . The low profile additive of claim 1 having a polydispersity of at least about 4.
3 . The low profile additive of claim 1 wherein the branched polyester resin is in admixture with at least one copolymerizable monomer.
4 . A composition comprising a low profile additive synthesized from one or more difunctional monomers and one or more branching agents.
5 . The composition of claim 4 wherein the difunctional monomer is a saturated aliphatic diacid or an anhydride thereof.
6 . The composition of claim 5 wherein the saturated aliphatic diacid is selected from the group consisting of succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, undecanedionic acid, dodecanedionic acid, cyclohexane dicarboxylic acid, a dimer acid, and combinations thereof.
7 . The composition of claim 4 wherein the difunctional monomer is a saturated aromatic diacid or an anhydride thereof.
8 . The composition of claim 7 wherein the saturated aromatic diacid is selected from the group consisting of phthalic acid, isophthalic acid, terephthalic acid, bisphenyl-4,4′-docarboxylic acid, diphenic acid, 2,6-naphthalene dicarboxylic acid, and combinations thereof.
9 . The composition of claim 4 wherein the difunctional monomer is a glycol.
10 . The composition of claim 9 wherein the glycol is selected from the group consisting of HO—(CH 2 ) n —OH, where n is 2 to 10; HO—(CH 2 —CH 2 —O—CH 2 —CH 2 ) n —OH, where n is 1 to 10; HO—(CH 2 —CH(CH 3 )—O—CH 2 —CH(CH 3 )) n —OH, where n is 1 to 10, cyclic glycol, bicyclic glycol and combinations thereof
11 . The composition of claim 9 wherein the glycol is selected from the group consisting of ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, butanediol, hexane diol, 2-methyl 1,3-propanediol, dipropylene glycol, neopentyl glycol, diethylene glycol, dipropylene glycol, cyclohexane diol, isosorbide and combinations thereof.
12 . The composition of claim 4 wherein branching agent comprises two or more functional groups.
13 . The composition of claim 12 wherein the functional groups are selected from the group consisting of anhydride, hydroxy, carboxy, epoxy, esters and combinations thereof.
14 . The composition of claim 4 wherein the branching agent is selected from the group consisting of polyacids, polyols, epoxy resins, polyhydroxyacids and combinations thereof.
15 . The composition of claim 4 wherein the branching agent is selected from the group consisting of glycerol, pentaerythritol, trimethylolpropane, polyetherpolyols, polyester polyols, vegetable oil-based polyols, polyepoxides, epoxidized vegetable oils, hydroxy-containing vegetable oils, polyfunctional monomers containing more than one type of functional group and combinations thereof.
16 . The composition of claim 15 wherein the polyepoxides are selected from the group consisting of polyglycidyl ethers of polyphenols, 1,5-dihydroxy naphthalene, modified epoxy resins with acrylate or urethane moieties, glycidylamine epoxy resins, novolac epoxy resins and combinations thereof.
17 . The composition of claim 16 wherein the polyglycidyl ethers of polyphenols are selected from the group consisting of bisphenol A, bisphenol-F, 1,1-bis(4-hydroxy phenyl)ethane, 1,1-bis(4-hydroxy phenyl)isobutene and combinations thereof.
18 . The composition of claim 15 wherein the polyfunctional monomers containing more than one type of functional group are selected from the group consisting of glycidol, 2,2-bis-(hydroxymethyl)propionic acid, citric acid, malic acid, tartaric acid, and combinations thereof.
19 . The composition of claim 15 wherein the epoxidized vegetable oil is selected from the group consisting of epoxidized soybean oil and epoxidized linseed oil.
20 . The composition of claim 15 wherein the hydroxy-containing vegetable oil is castor oil.
21 . The composition of claim 4 wherein the low profile additive is synthesized with about 0.1 mole % to about 10 mole % of one or more branching agents.
22 . A composite material comprising the low profile additive of claim 1 .
23 . The composite material of claim 22 further comprising an unsaturated polyester resin, vinyl ester resin, or mixtures thereof, one or more unsaturated monomers copolymerizable with the unsaturated polyester or vinyl ester resin, and reinforcing fibers.
24 . The composite material of claim 23 further wherein the amount of low profile additive is between about 5 to about 35 parts solid per 100 weight parts of the total amount of resin, the low profile additive and the unsaturated monomer.
25 . The composite material of claim 22 further comprising an other low profile additive.
26 . The composite material of claim 25 wherein the other low profile additive is selected from the group consisting of polyvinyl acetate, polystyrene, polymethyl methacrylate and combinations thereof.
27 . The composite material of claim 22 further comprising one or more enhancers.
28 . The composite material of claim 27 wherein the enhancer is selected from the group consisting of tall oil fatty acid capped adipic acid diethylene glycol oligomers, octyl epoxy tallate, epoxidized linseed oil, tall oil fatty acid capped multi functional epoxy, fatty acid capped multi functional polyols and combinations thereof.
29 . A molded article comprising the composite material of claim 22 .
30 . A method of making a branched low profile additive comprising the step of reacting one or more branching agents with one or more monomers resulting in a branched polymeric low profile additive having a weight average molecular weight (Mw) of at least about 20,000 grams/mol and a number average molecular weight (Mn) of at least about 3,000 grams/mol.
31 . The method of claim 30 wherein the branching agent is a generative type and the method comprises the additional steps of mixing the branching agent with an esterification catalyst and the monomer and then heating the mixture.
32 . The method of claim 31 wherein the esterification catalyst is selected from the group consisting of titanium tetrachloride, zinc acetate, zinc oxide, stannous oxalate, dibutyl tin oxide, phosphoric acid and combinations thereof.
33 . The method of claim 31 wherein the mixture is heated to a temperature of about 120° C. and about 230° C.
34 . The method of claim 30 wherein the branching agent is selected from the group consisting of a non-generative type, a generative/non-generative type, and combinations thereof comprising the additional steps of simultaneously mixing the branching agent, an esterification catalyst and the monomer and then allowing the mixture to react under esterification conditions.
35 . The method of claim 34 wherein the esterification catalyst is selected from the group consisting of titanium tetrachloride, zinc acetate, zinc oxide, stannous oxalate, dibutyl tin oxide, phosphoric acid and combinations thereof.
36 . The method of claim 30 wherein the branching agent is selected from the group consisting of a generative type, a non-generative, a generative/non-generative type, and combinations thereof.