Low delamination mold release
Methods and combinations of a curing catalyst with a mold release mixture, which is then subsequently applied to the surface of a mold prior to the application of polyurethane reactants to said mold, where the curing catalyst component has the effect of catalyzing the reaction at the surface of the molded part. This catalysis results in greater reactivity at the surface between reacting portions and lower delamination of the surface of the foam, thereby leading to more attractive skins with a more consistent cell structure, and lower de-mold times due to skins whose nature makes them less likely to adhere to the surface of the mold. These foams will be less likely to tear upon opening of the mold, and production quality and output will be improved.
1. A mold release mixture comprising a barrier release coating and a curing catalyst, where the mold release mixture prevents adherence of polyurethane reactants to a mold surface that was coated with the mold release mixture prior to addition of polyurethane reactants to the mold, where the curing catalyst is selected from the group consisting of amides; carbamide; metal catalyst comprising soaps, alcoholates or salts of metals having the formula:
Me(OR′) m X n−m
where Me is a metal having an atomic number in the range of 21 to 83, R′ is selected from the group consisting of aliphatic, cycloaliphatic, and aryl hydrocarbon radicals containing at least six carbon atoms, n is the valence of the metal Me and is at least 3, X is an organic carboxylic acid radical and m is a positive integer selected from the range of 0 to the valence of the metal Me, such that the metal catalyst catalyzes the chemical reaction between polyisocyanate and polyurethane with accompanying foaming of said composition; and combinations thereof.
2. The mold release mixture of claim 1 where the barrier release coating concentration is in the range of about 0.1 to about 99.9% by weight of the mold release mixture and is selected from the group consisting of lubricating oils, solid lubricants, waxes, lipids, esters of fatty acids, polyalphaolefins, polysiloxanes and combinations thereof.
3. The mold release mixture of claim 1 where the curing catalyst concentration is in the range of about 0.01 to about 98% by weight of the mold release mixture.
4. The mold release mixture of claim 3 , where the curing catalyst is an amide, defined here as an organic compound, R, containing the group —C(O)NH 2 , where the R group is either a hydrogen atom or a collection of bonded molecules, at least one of which is carbon and serves as the bonding site for other attached groups in the overall compound.
5. The mold release mixture of claim 3 where the curing catalyst is carbamide.
6. The mold release mixture of claim 1 additionally comprising a solvent that is water.
7. The mold release mixture of claim 1 additionally comprising an organic solvent with a boiling point of less than 200° C. at 760 mmHg.
8. The mold release mixture of claim 1 additionally comprising a semi-volatile organic solvent with a boiling point of between about 200° C. to about 500° C. at 760 mmHg.
9. The mold release mixture of claim 1 where the mold release mixture comprises a liquid, solid, or paste at 25° C. and 760 mmHg.
10. The mold release mixture of claim 1 additionally comprising an emulsifier capable of producing an emulsion of some or all of the barrier release coating and the curing catalyst of the mold release mixture.
11. The mold release mixture of claim 9 , where the emulsifier has a HLB value from about 4 to about 20.
12. The mold release mixture of claim 9 where the emulsifier has a HLB value from about 8 to about 18.
13. The mold release mixture of claim 9 where the emulsifier has a HLB value from about 4 to about 6.
14. A mold release mixture comprising a curing catalyst in a concentration of between about 0.1 to about 98% by weight of the mold release mixture where the curing catalyst is selected from the group consisting of amides; carbamide; a metal catalyst comprising soaps, alcoholates or salts of metals having the formula:
Me(OR′) m X n−m
where Me is a metal having an atomic number in the range of 21 to 83, R′ is selected from the group consisting of aliphatic, cycloaliphatic, and aryl hydrocarbon radicals containing at least six carbon atoms, n is the valence of the metal Me and is at least 3, X is an organic carboxylic acid radical and m is a positive integer selected from the range of 0 to the valence of the metal Me, such that the metal catalyst catalyzes the chemical reaction between polyisocyanate and polyurethane with accompanying foaming of said composition; and combinations thereof; which curing catalyst is suspended in a solvent selected from the group consisting of water, an organic solvent with a boiling point less than or equal to 500° C., and mixtures thereof.
15. The mold release mixture of claim 14 further comprising an emulsifier capable of producing an emulsion of some or all of the barrier release coating and the curing catalyst of the mold release mixture.