POLYETHER-SILOXANE BLOCK COPOLYMERS FOR PRODUCING POLYURETHANE FOAMS

Abstract

A process for preparing polyether-siloxane block copolymers by hydrosilylation of alpha, omega-modified hydrosiloxanes with alpha,omega-modified di(meth)allyl polyethers in the presence of a hydrosilylation catalyst, wherein the reaction is performed in a solvent mixture comprising aromatic solvents and alkoxylated alcohol, is described.

Claims

1-15. (canceled)

16. A process for preparing polyether-siloxane block copolymers of formula 1: ##STR00023## wherein: a=0 to 100, b=0 to 100, c=0 to 100, and a+b+c>3, d=1 to 100, n=5 to 200, wherein R.sup.1 radicals are independently identical or different monovalent aliphatic or aromatic hydrocarbon radicals having 1 to 20 carbon atoms, wherein R.sup.2 radicals are independently identical or different monovalent aliphatic, saturated or unsaturated hydrocarbon radicals having 1 to 20 carbon atoms or OH, wherein R.sup.3 radicals are independently identical or different monovalent aliphatic or aromatic hydrocarbon radicals having 1 to 20 carbon atoms, wherein R.sup.4 radicals are independently selected from one of R.sup.5, R.sup.6, R.sup.7 radicals and H, wherein R.sup.5 radicals conform to formula 2: ##STR00024## wherein R.sup.6 radicals conform to formula 3: ##STR00025## and where R.sup.7 radicals conform to the formula 4: ##STR00026## wherein the indices a, b and c and R.sup.2 and R.sup.3 radicals are as defined above, by hydrosilylation of alpha,omega-modified hydrosiloxanes with alpha,omega-modified di(meth)allyl polyethers in the presence of a hydrosilylation catalyst capable of catalysing the formation of an SiC bond by addition of an SiH group to a (meth)allylic double bond, wherein the reaction is conducted in a solvent mixture comprising at least one aromatic solvent of formula 5: ##STR00027## wherein: x=0-20, y=0-20, x+y=6-20, and at least one alkoxylated alcohol of formula 6: ##STR00028## wherein: j=0 to 30, k=0 to 20, l=1 to 20, wherein the R.sup.9 radical is a monovalent aliphatic saturated or unsaturated, linear or branched hydrocarbon radical having 6-40 carbon atoms, and wherein R.sup.8 radicals are independently identical or different monovalent aliphatic or aromatic hydrocarbon radicals having 1 to 20 carbon atoms.

17. The process of claim 16, wherein: in formula 1: a=5 to 75, b=5 to 75, c=5 to 75, d=5 to 50, n=10 to 100, and wherein the R.sup.1 radicals are methyl radicals, wherein the R.sup.2 radicals are methyl radicals, in formula 5: x=0-16, y=0-16, x+y=8-16, in formula 6: j=0 to 10, k=0 to 10, l=2 to 10, and wherein the R.sup.9 radical is a monovalent aliphatic saturated or unsaturated, linear or branched hydrocarbon radical having 10-22, carbon atoms.

18. The process of claim 16, wherein: in formula 1: a=10 to 50, b=5 to 25, c=5 to 25, d=7 to 40, and n=15 to 50.

19. The process of claim 16, wherein: in formula 1: d=12 to 30, and n=15 to 50.

20. The process of claim 16, wherein: in formula 6: j=0 to 10, k=0 to 10, l=2 to 10.

21. The process of claim 16, wherein the aromatic solvent of formula 5 and the alkoxylated alcohol of formula 6 are used in a mass ratio of 1:2 to 15:1.

22. The process of claim 16, wherein the aromatic solvent of formula 5 and the alkoxylated alcohol of formula 6 are used in a mass ratio of 3:2 to 12:1.

23. The process of claim 16, wherein the sum total of the masses of aromatic solvent of formula 5 and of the alkoxylated alcohol of formula 6 is in a ratio of 8:2 to 1:4 to the sum total of the masses of the reactants.

24. The process of claim 16, wherein the alpha,omega-modified di(meth)allyl polyether is used at a concentration such that the molar ratio of polyether-bound double bonds to siloxane-bound SiH groups is in the range from 0.95:1.05 to 1.05:0.95.

25. The process of claim 16, wherein the hydrosilylation catalyst used for the reaction is a platinum catalyst.

26. A formulation suitable as an additive for the production of polyurethane foams, comprising the following components: (a) polyether-siloxane block copolymers of formula 1: ##STR00029## wherein: a=0 to 100, b=0 to 100, c=0 to 100, d=1 to 100, n=5-200, wherein R.sup.1 radicals are each independently identical or different monovalent aliphatic or aromatic hydrocarbon radicals having 1 to 20 carbon atoms, wherein R.sup.2 radicals are independently identical or different monovalent aliphatic, saturated or unsaturated hydrocarbon radicals having 1 to 20 carbon atoms or OH, wherein R.sup.3 radicals are independently identical or different monovalent aliphatic or aromatic hydrocarbon radicals having 1 to 20 carbon atoms, wherein R.sup.4 radicals are independently selected from R.sup.5, R.sup.6, R.sup.7 radicals and H, where R.sup.5 radicals conform to formula 2: ##STR00030## wherein R.sup.6 radicals conform to formula 3: ##STR00031## wherein R.sup.7 radicals conform to formula 4: ##STR00032## wherein the indices a, b and c and the R.sup.2 and R.sup.3 radicals are as defined above, (b) an aromatic solvent of formula 5: ##STR00033## wherein: x=0-20, y=0-20, x+y=6-20, and (c) an alkoxylated alcohol of the formula 6: ##STR00034## wherein: j=0 to 30, k=1 to 20, l=1 to 20, and wherein the R.sup.9 radical is a monovalent aliphatic saturated or unsaturated, linear or branched hydrocarbon radical having 6-40, carbon atoms, and wherein R.sup.8 radicals are independently identical or different monovalent aliphatic or aromatic hydrocarbon radicals having 1 to 20 carbon atoms.

27. The formulation of claim 26, wherein in formula 1: a=0 to 100, b=0 to 100, c=0 to 100, d=1 to 100, n=5-200, and wherein the R.sup.1 radicals are each independently identical or different monovalent aliphatic or aromatic hydrocarbon radicals having 1 to 10 carbon atoms; wherein the R.sup.2 radicals are independently identical or different monovalent aliphatic, saturated or unsaturated hydrocarbon radicals having 1 to 20 carbon atoms OH; and wherein the R.sup.3 radicals are independently identical or different monovalent aliphatic or aromatic hydrocarbon radicals having 1 to 20 carbon atoms.

28. The formulation of claim 27, wherein R.sup.2 and R.sup.3 are methyl radicals.

29. The formulation of claim 26, wherein, in formula 5: x=0-16; y=0-16; and x+y=8-16.

30. The formulation of claim 26, wherein, in formula 6: j=0 to 10, k=2 to 10, l=2 to 10, wherein the R.sup.9 radical is a monovalent aliphatic saturated or unsaturated, linear or branched hydrocarbon radical having 10-22, carbon atoms, and wherein the R.sup.8 radicals are methyl radicals.

31. The formulation of claim 26, wherein the ratio of the sum total of the masses of (b) and (c) to (a) is 8:2 to 1:4.

32. The formulation of claim 26, wherein the polyether-siloxane block copolymer of formula 1 has a M.sub.w (g/mol) of 60 000, where M.sub.w/M.sub.n<4.5.

33. The formulation of claim 26, further comprising at least one pendent polyethersiloxane-based stabilizer having a siloxane chain bearing pendent and/or terminal polyether chains, where the polyether chains may be bonded to the silicone chain via either a silicon-carbon bond (SiC) or a silicon-oxygen-carbon bond (SiOC).

34. The formulation of claim 33, wherein polyether chains are bonded to the silicone by a SiC-based polyethersiloxanes that conform to formula 7: ##STR00035## wherein: x=0 to 50, y=0 to 250, and where R.sup.9 radicals are independently identical or different monovalent aliphatic or aromatic hydrocarbon radicals having 1 to 20 carbon atoms, and wherein R.sup.10 radicals are independently identical or different OH-functional or-terminated, and wherein R.sup.11 radicals correspond either to R.sup.9 or R.sup.10.

35. A polyether-siloxane block copolymer, prepared by the process of claim 16.

Description

EXAMPLES

[0176] The examples which follow serve solely for elucidation of this invention to the person skilled in the art and do not constitute any kind of restriction of the subject-matter claimed.

Materials

a) SiH siloxane A

[0177] In the syntheses that follow, a siloxane of the general formula a was used.

##STR00021##

b) Bismethallyl polyether A

[0178] In the syntheses that follow, a bismethallyl polyether of the general formula b was used.

##STR00022##

Synthesis examples

Example 1: Synthesis in Toluene (Comparative Example)

[0179] A 500 ml three-neck flask with precision glass stirrer and reflux condenser was initially charged with 73 g of bismethallyl polyether A. Subsequently, 103 g of toluene and 30 g of SiH siloxane A were added. The reaction mixture was heated to 80 C. Thereafter, 10 ppm of Pt was added in the form of the Karstedt catalyst solution. The reaction mixture was heated to 95 C. and stirred at that temperature for 3 hours. The result was a gel-like product that was intermediately diluted with a further 103 g of toluene in order to keep it stirrable. A clear gel-like product was obtained. Because viscosity was very high, it was not possible to remove the solvent by distillation.

Example 2: Synthesis in toluene/alkoxylated Alcohol (Comparative Example)

[0180] A 1000 ml three-neck flask with precision glass stirrer and reflux condenser was initially charged with 73 g of bismethallyl polyether A. Subsequently, 103 g of toluene, 103 g of Varonic APM T (myristyl alcohol propoxylate) and 30 g of the SiH siloxane A were added. The reaction mixture was heated to 80 C. Thereafter, 10 ppm of Pt was added in the form of the Karstedt catalyst solution. The reaction mixture was heated to 95 C. and stirred at that temperature for 3 hours. The volatile constituents were then removed under reduced pressure at 130 C. and 1 mbar. A cloudy product was obtained.

Example 3: Synthesis in dodecylbenzene/alkoxylated Alcohol

[0181] A 1000 ml three-neck flask with precision glass stirrer and reflux condenser was initially charged with 73 g of bismethallyl polyether A. Subsequently, 103 g of dodecylbenzene (CAS number: 123-01-3), 103 g of Varonic APM T (myristyl alcohol propoxylate) and 30 g of the SiH siloxane A. The reaction mixture was heated to 80 C. Thereafter, 10 ppm of Pt was added in the form of the Karstedt catalyst solution. The reaction mixture was heated to 95 C. and stirred at that temperature for 3 hours. The volatile constituents were then removed under reduced pressure at 130 C. and 1 mbar. A clear product of high viscosity was obtained.

TABLE-US-00001 TABLE 1 Overview of experiments w (SiH siloxane + bismethallyl w (aromatic W (Varonic Ex. polyether) Aromatic solvent solvent) APM T) Mw / (g/mol) Appearance 1 50% toluene 50% 0% 164254 gel-like 2 33.34% toluene 33.33% 33.33% 96000 cloudy 3 33.34% dodecylbenzene 33.33% 33.33% 115807 clear

[0182] Comparison of examples 2 and 3 shows that the use of dodecylbenzene in conjunction with an alkoxylated alcohol enables the production of clear products. Moreover, dodecylbenzene is not an inflammable solvent. Because of these two points, the product has better suitability as foam stabilizer.