Curable silicone rubber compounds

Abstract

Compositions of curable silicone rubber compounds containing at least one metal siloxane-silanol(-ate) compound, a method for preparing curable silicone rubber compounds containing at least one metal siloxane-silanol(-ate) compound, as well as the use of curable silicone rubber compounds containing at least one metal siloxane-silanol(-ate) compound as a sealant, an adhesive material, a potting compound and/or a coating agent.

Claims

1. A composition obtained by mixing the following components: a. at least one silicone compound having the general formula HO—(SiR.sup.lR.sup.mO).sub.o—H, wherein R.sup.l and R.sup.m denote independently of one another an optionally substituted hydrocarbon radical having 1 to 20 carbon atoms and o is an integer of from 5 to 4,000, b. a catalyst, wherein the catalyst contains at least one metal siloxane-silanol(-ate) compound, and c. at least one crosslinker having the general formula Si(R).sub.m(R.sup.a).sub.4-m, wherein each R denotes independently of one another an optionally substituted hydrocarbon radical having 1 to 20 carbon atoms, m is an integer of from 0 to 2, each R.sup.a is selected independently of one another from the group consisting of a hydroxycarboxylic acid ester radical having the general structural formula (I): ##STR00018## wherein each R.sup.b denotes independently of one another H or an optionally substituted hydrocarbon radical having 1 to 20 carbon atoms, each R.sup.c denotes independently of one another H or an optionally substituted hydrocarbon radical having 1 to 20 carbon atoms, R.sup.d denotes an optionally substituted hydrocarbon radical having 1 to 20 carbon atoms, R.sup.e denotes C or an optionally substituted hydrocarbon radical having 1 to 20 carbon atoms, and n is an integer of from 1 to 10, a hydroxycarboxylic acid amide radical having the general structural formula (II): ##STR00019## wherein each R.sup.n denotes independently of one another H or an optionally substituted hydrocarbon radical having 1 to 20 carbon atoms, each R.sup.o denotes independently of one another H or an optionally substituted hydrocarbon radical having 1 to 20 carbon atoms, R.sup.p and R.sup.q denote independently of one another H or an optionally substituted hydrocarbon radical having 1 to 20 carbon atoms, R.sup.r denotes C or an optionally substituted hydrocarbon radical having 1 to 20 carbon atoms, and p is an integer of from 1 to 10, a carboxylic acid radical —O—C(O)—R.sup.f, wherein R.sup.f denotes H or an optionally substituted hydrocarbon radical having 1 to 20 carbon atoms, an oxime radical —O—N═CR.sup.gR.sup.h, wherein R.sup.g and R.sup.h denote independently of one another H or an optionally substituted hydrocarbon radical having 1 to 20 carbon atoms, and a carboxylic acid amide radical —N—(R.sup.i)—C(O)—R.sup.j, wherein R.sup.i denotes H or an optionally substituted hydrocarbon radical having 1 to 20 carbon atoms, and R.sup.j denotes H or an optionally substituted hydrocarbon radical having 1 to 20 carbon atoms.

2. The composition of claim 1, wherein the metal siloxane-silanol(-ate) compound is in a molar concentration in the range of from 0.00001 to 0.01 mol/kg, based on the total weight of the composition.

3. The composition of claim 2, wherein the metal siloxane-silanol(-ate) compound is in a molar concentration in the range of from 0.00005 to 0.005 mol/kg, based on the total weight of the composition.

4. The composition of claim 1, wherein the metal siloxane-silanol(-ate) compound is present at a proportion by weight of from 0.001 to 0.5%.

5. The composition of claim 1, wherein the molar ratio of crosslinker of the general formula Si(R).sub.m(R.sup.a).sub.4-m, wherein the crosslinker may also be present as a crosslinker mixture, to M3S catalyst is 20 to 2,000.

6. The composition of claim 1, wherein the metal siloxane-silanol(-ate) compound is present as a monomer, oligomer and/or polymer, and wherein the metal or metals is/are present terminally and/or within the chain.

7. The composition of claim 1, wherein the metal siloxane-silanol(-ate) compound contains an oligomeric metal silsesquioxane.

8. The composition of claim 7, wherein the metal silsesquioxane has the general formula R*.sub.qSi.sub.rO.sub.sM.sub.t, wherein each R* is selected independently of one another from the group consisting of optionally substituted C1 to C20 alkyl, optionally substituted C3 to C6 cycloalkyl, optionally substituted C2 to C20 alkenyl, optionally substituted C6 to C10 aryl, —OH and —O—(C1 to C10 alkyl), each M is selected independently of one another from the group consisting of s and p block metals, d and f block transition metals, lanthanide and actinide metals and semimetals, q is an integer of from 4 to 19, r is an integer of from 4 to 10, s is an integer of from 8 to 30, and t is an integer of from 1 to 8.

9. The composition of claim 8, wherein each M is selected independently of one another from the group consisting of metals of the 1st, 2nd, 3rd, 4th, 5th, 8th, 10th and 11th subgroup and metals of the 1st, 2nd, 3rd, 4th and 5th main group.

10. The composition of claim 7, wherein the metal silsesquioxane has the general formula (III) ##STR00020## wherein X.sup.1, X.sup.2 and X.sup.3 are selected independently of one another from Si or M.sup.1, wherein M.sup.1 is selected from the group consisting of Zn, Ti, Zr, Hf, V, Fe, Sn and Bi, Z.sup.1, Z.sup.2 and Z.sup.3 are selected independently of one another from the group consisting of L.sup.2, R.sup.5, R.sup.6 and R.sup.7, wherein L.sup.2 is selected from the group consisting of —OH and —O—(C1 to C10 alkyl), or wherein L.sup.2 is selected from the group consisting of —OH, —O-methyl, —O-ethyl, —O-propyl, —O-butyl, —O-octyl, —O-isopropyl, and —O-isobutyl; R.sup.1, R.sup.2, R.sup.3, R.sup.4, R.sup.5, R.sup.6 and R.sup.7 are selected independently of one another from the group consisting of optionally substituted C1 to C20 alkyl, optionally substituted C3 to C8 cycloalkyl, optionally substituted C2 to C20 alkenyl and optionally substituted C5 to C10 aryl; Y.sup.1 and Y.sup.2 denote independently of one another —O-M.sup.2-L.sup.3.sub.Δ, or Y.sup.1 and Y.sup.2 are taken together and together denote —O-M.sup.2(L.sup.3.sub.Δ)-O— or —O—, wherein L.sup.3 is selected from the group consisting of —OH and —O—(C1 to C10 alkyl), or wherein L.sup.3 is selected from the group consisting of —OH, —O-methyl, —O-ethyl, —O-propyl, —O-butyl, —O-octyl, —O-isopropyl, and —O-isobutyl, and wherein M.sup.2 is selected from the group consisting of s and p block metals, d and f block transition metals, lanthanide and actinide metals and semimetals, and X.sup.4 denotes -M.sup.3L.sup.1.sub.Δ or M.sup.3, and Q.sup.1 and Q.sup.2 denote H or in each case a single bond linked to M.sup.3, wherein L.sup.1 is selected from the group consisting of —OH and —O—(C1 to C10 alkyl), or wherein L.sup.1 is selected from the group consisting of —OH, —O-methyl, —O-ethyl, —O-propyl, —O-butyl, —O-octyl, —O-isopropyl, and —O-isobutyl, and wherein M.sup.3 is selected from the group consisting of s and p block metals, d and f block transition metals, lanthanide and actinide metals and semimetals, or X.sup.4 denotes -M.sup.3L.sup.1.sub.Δ and Q.sup.2 denotes H or a single bond linked to M.sup.3, and Q.sup.1 denotes H, M.sup.4L.sup.4.sub.Δ or —SiR.sup.8, wherein M.sup.4 is selected from the group consisting of s and p block metals, d and f block transition metals, lanthanide and actinide metals and semimetals, and wherein L.sup.4 is selected from the group consisting of —OH and —O—(C1 to C10 alkyl), or wherein L.sup.4 is selected from the group consisting of —OH, —O-methyl, —O-ethyl, —O-propyl, —O-butyl, —O-octyl, —O-isopropyl, and —O-isobutyl, and wherein R.sup.8 is selected from the group consisting of optionally substituted C1 to C20 alkyl, optionally substituted C3 to C8 cycloalkyl, optionally substituted C2 to C20 alkenyl and optionally substituted C5 to C10 aryl, or X.sup.4, Q.sup.1 and Q.sup.2 denote independently of one another -M.sup.3L.sup.1.sub.Δ.

11. The composition of claim 10, wherein the metal silsesquioxane has the structural formula (V) ##STR00021##

12. The composition of claim 10, wherein M.sup.1, M.sup.2, M.sup.3 and M.sup.4 are each independently selected from the group consisting of metals of the 1st, 2nd, 3rd, 4th, 5th, 8th, 10th and 11th subgroup and metals of the 1st, 2nd, 3rd, 4th and 5th main group.

13. The composition of claim 10, wherein L.sup.1, L.sup.2, L.sup.3 and L.sup.4 are each independently selected from —O—(C1 to C8 alkyl) and —O—(C1 to C6 alkyl).

14. The composition of claim 7, wherein the metal silsesquioxane has the structural formula (VI) ##STR00022## wherein titanium is linked to OR, wherein R is selected from the group consisting of —H, -methyl, -ethyl, -propyl, -butyl, -octyl, -isopropyl, and -isobutyl, Z.sup.1, Z.sup.2 and Z.sup.3 denote each independently of one another C1 to C20 alkyl, C3 to C8 cycloalkyl, C2 to C20 alkenyl or C5 to C10 aryl, and R.sup.1, R.sup.2, R.sup.3 and R.sup.4 denote each independently of one another C1 to C20 alkyl, C3 to C8 cycloalkyl, C2 to C20 alkenyl, or C5 to C10 aryl.

15. The composition of claim 14, wherein Z.sup.1, Z.sup.2, Z.sup.3, R.sup.1, R.sup.2, R.sup.3 and R.sup.4 denote each independently of one another methyl, ethyl, propyl, isopropyl, butyl, isobutyl, hexyl, heptyl, octyl, vinyl, allyl, butenyl and phenyl, or benzyl.

16. The composition of claim 7, wherein the metal silsesquioxane has the structure (VII) ##STR00023## wherein each Si is linked to an isobutyl radical, and titanium carries an ethanolate ligand.

17. The composition of claim 7, wherein the oligomeric metal silsesquioxane is a polyhedral metal silsesquioxane.

18. The composition of claim 1, wherein in the silicone compound having the general formula HO—(SiR.sup.lR.sup.mO).sub.o—H, R.sup.l and R.sup.m denote independently of one another an optionally substituted, straight chain or branched C1 to C16 alkyl group, an optionally substituted, straight chain or branched C2 to C16 alkenyl group, or an optionally substituted C4 to C14 aryl group.

19. The composition of claim 18, wherein R.sup.l and R.sup.m denote independently of one another an optionally substituted, straight chain or branched C1 to C12 alkyl group, an optionally substituted, straight chain or branched C2 to C12 alkenyl group, or an optionally substituted C4 to C10 aryl group.

20. The composition of claim 1, wherein in the crosslinker having the general formula Si(R).sub.m(R.sup.a).sub.4-m, each R denotes independently of one another an optionally substituted, straight chain or branched C1 to C12 alkyl group, or an optionally substituted, straight chain or branched C2 to C12 alkenyl group, or an optionally substituted C4 to C10 aryl group, each R.sup.a is selected independently of one another from the group consisting of a hydroxycarboxylic acid ester radical having the general structural formula (I): ##STR00024## a hydroxycarboxylic acid amide radical having the general structural formula (II): ##STR00025## a carboxylic acid radical —O—C(O)—R.sup.f, an oxime radical —O—N═CR.sup.gR.sup.h, a carboxylic acid amide radical —N—(R.sup.i)—C(O)—R.sup.j, wherein each R.sup.b and R.sup.c denotes independently of one another an optionally substituted, straight chain or branched C1 to C12 alkyl group, R.sup.d denotes an optionally substituted, straight chain or branched C1 to C12 alkyl group, a C4 to C10 cycloalkyl group, a C5 to C11 aralkyl group or a C4 to C10 aryl group, R.sup.e is a divalent benzene radical, or R.sup.e denotes C, and R.sup.b and R.sup.c denote H, or R.sup.e denotes C, and R.sup.b denotes H, and R.sup.c denotes methyl, n is an integer of from 1 to 5, wherein each R.sup.a and R.sup.o denotes independently of one another H or an optionally substituted, straight chain or branched C1 to C12 alkyl group, R.sup.p and R.sup.q denote independently of one another H or an optionally substituted, straight chain or branched C1 to C12 alkyl group, or an optionally substituted C4 to C14 cycloalkyl group or a C5 to C11 aralkyl group or a C4 to C10 aryl group, R.sup.r is a divalent benzene radical, or R.sup.r denotes C, and R.sup.n and R.sup.o denote H, or R.sup.r denotes C, and R.sup.n denotes H, and R.sup.o denotes methyl, p is an integer of from 1 to 5, wherein R.sup.f denotes H or an optionally substituted, straight chain or branched C1 to C12 alkyl group, an optionally substituted C4 to C10 cycloalkyl group or an optionally substituted C4 to C10 aryl group or an optionally substituted C5 to C11 aralkyl group, wherein R.sup.g and R.sup.h denote independently of one another H or an optionally substituted, straight chain or branched C1 to C12 alkyl group, an optionally substituted C4 to C10 cycloalkyl group or an optionally substituted C4 to C10 aryl group or an optionally substituted C5 to C11 aralkyl group, and wherein R.sup.i and R.sup.j denote independently of one another H or an optionally substituted, straight chain or branched C1 to C12 alkyl group, an optionally substituted C4 to C10 cycloalkyl group or an optionally substituted C4 to C10 aryl group or an optionally substituted C5 to C11 aralkyl group.

21. The composition of claim 20, wherein in the crosslinker having the general formula Si(R).sub.m(R.sup.a).sub.4-m, each R denotes independently of one another an optionally substituted, straight chain or branched C1 to C8 alkyl group, an optionally substituted straight chain or branched C2 to C8 alkenyl group, or an optionally substituted C4 to C10 aryl group.

22. The composition of claim 20, wherein each R.sup.b and R.sup.c denotes independently of one another an optionally substituted, straight chain or branched C1 to C8 alkyl group.

23. The composition of claim 20, wherein R.sup.d denotes an optionally substituted, straight chain or branched C1 to C8 alkyl group, a C4 to C10 cycloalkyl group, a C5 to C11 aralkyl group or a C4 to C10 aryl group.

24. The composition of claim 20, wherein n and p are each independently an integer from 1 to 3.

25. A method for crosslinking a composition, wherein said method comprises contacting a composition with a catalyst, wherein said catalyst contains a metal siloxane-silanol(-ate) compound, and wherein said composition has been obtained by mixing a silicone compound having the general formula HO—(SiR.sup.lR.sup.mO).sub.o—H with a crosslinker having the general formula Si(R).sub.m(R.sup.a).sub.4-m, wherein m and the radicals R and R.sup.a, o and the radicals R.sup.l and R.sup.m, and the catalyst, are all defined in accordance with claim 1.

26. The composition of claim 1, wherein the silicone compound having the general formula HO—(SiR.sup.lR.sup.mO).sub.o—H and the crosslinker having the general formula Si(R).sub.m(R.sup.a).sub.4-m is present in the form of a prepolymer, wherein the prepolymer is obtainable by reacting the silicone compound and the crosslinker having the general formula Si(R).sub.m(R.sup.a).sub.4-m.

27. A method for preparing a composition, wherein said method comprises the following steps: a. providing a composition containing i. at least one silicone compound having the general formula HO—(SiR.sup.lR.sup.mO).sub.o—H, ii. a catalyst, wherein the catalyst contains at least one metal siloxane-silanol(-ate) compound, iii. at least one crosslinker having the general formula Si(R).sub.m(R.sup.a).sub.4-m, b. mixing the composition, provided in a., using mechanical and/or thermal energy, wherein o and the radicals R.sup.l and R.sup.m in (i.), and m and the radicals R and R.sup.a in (iii.), are defined in accordance with claim 1.

28. A composition obtained by the method of claim 27.

29. A method for sealing materials obtained by curing a composition containing i. at least one silicone compound having the general formula HO—(SiR.sup.lR.sup.mO).sub.o—H, ii. a catalyst, wherein the catalyst contains at least one M3S compound, and iii. at least one crosslinker having the general formula Si(R).sub.m(R.sup.a).sub.4-m, wherein o and the radicals R.sup.l and R.sup.m in (i.), and m and the radicals R and R.sup.a in (iii.), are defined in accordance with claim 1.

30. The composition of claim 1, wherein said composition is formulated as a sealant, adhesive material, potting compound, or a coating agent.

31. The composition of claim 1, wherein said at least one metal siloxane-silanol(-ate) compound comprises a metal selected from the group consisting of s and p block metals, d and f block transition metals, lanthanide and actinide metals and semimetals.

32. The composition of claim 1, wherein in said at least one crosslinker having the general formula Si(R).sub.m(R.sup.a).sub.4-m, each R denotes independently of one another an optionally substituted, straight chain or branched C1 to C16 alkyl group, an optionally substituted, straight chain or branched C2 to C16 alkenyl group, or an optionally substituted C4 to C14 aryl group.

33. The composition of claim 1, wherein each R.sup.b, R.sup.c, R.sup.n, R.sup.o denotes independently of one another H or an optionally substituted, straight chain or branched C1 to C16 alkyl group or an optionally substituted C4 to C14 aryl group.

34. The composition of claim 1, wherein R.sup.d denotes an optionally substituted, straight chain or branched C1 to C16 alkyl group, an optionally substituted C4 to C14 cycloalkyl group, an optionally substituted C5 to C15 aralkyl group or an optionally substituted C4 to C14 aryl group.

35. The composition of claim 1, wherein R.sup.e and R.sup.r each independently denotes C or an optionally substituted saturated or partially unsaturated cyclic ring system having 4 to 14 C atoms or an optionally substituted aromatic group having 4 to 14 C atoms.

36. The composition of claim 1, wherein R.sup.p and R.sup.q denote independently of one another H or an optionally substituted, straight chain or branched C1 to C16 alkyl group, an optionally substituted C4 to C14 cycloalkyl group, an optionally substituted C5 to C15 aralkyl group or an optionally substituted C4 to C14 aryl group.

37. The composition of claim 1, wherein R.sup.f, R.sup.g, R.sup.h, R.sup.i and R.sup.j denote independently of one another H or an optionally substituted, straight chain or branched C1 to C16 alkyl group, an optionally substituted C4 to C14 cycloalkyl group or an optionally substituted C4 to C14 aryl group or an optionally substituted C5 to C15 aralkyl group.

Description

EXAMPLE 1

(1) α,ω-dihydroxypolyorganosiloxane (30 to 70% by wt.), which is selected from α,ω-dihydroxyl-terminated polydimethylsiloxanes, α,ω-dihydroxyl-terminated polydiethylsiloxanes or α,ω-dihydroxyl-terminated polydivinylsiloxanes, as well as α,ω-dihydroxyl-terminated polydiarylsiloxanes, such as, for example, α,ω-dihydroxyl-terminated polydiphenylsiloxanes. In this case preference is given to polyorganosiloxanes that have a kinematic viscosity of from 5,000 to 120,000 cSt (at 25° C.), in particular, those having a viscosity of from 20,000 to 100,000 cSt, and more preferably those having a viscosity of from 40,000 to 90,000 cSt. It is also possible to use mixtures of polydiorganosiloxanes having different viscosities, polydialkylsiloxane 50 to 150 cSt (15 to 45% by wt.); a crosslinker containing at least one silane (0.5 to 4.5% by wt.) and/or a mixture of at least two silanes (0.5 to 9% by wt.), of the general formula Si(R).sub.m(R.sup.a).sub.4-m were mixed under vacuum. Thereafter, a filler, preferably silica (5 to 15% by wt.), was optionally dispersed therein and stirred under vacuum until the mass is smooth. Then 0.001 to 0.5% by wt. of a metal silsesquioxane, according to claim 10, and optionally an adhesion promoter (0.5 to 2% by wt.), as described above, were incorporated by mixing under vacuum.

(2) TABLE-US-00001 Component % by wt. 1 α,ω-dihydroxypolyorganosiloxane 30 to 70 20,000 to 80,000 cSt 2 polyalkylsiloxanes 50 to 150 cSt 15 to 45 3 crosslinker 1 0.5 to 4.5 4 crosslinker 2 0.5 to 4.5 5 filler  5 to 15 6 adhesion promoter 0.5 to 2.sup.  7 M3S catalyst 0.001 to 0.5 

EXAMPLE 2

(3) α,ω-dihydroxydimethyl-polysiloxane 80,000 cSt (30 to 70% by wt.), polydimethylsiloxane 100 cSt (15 to 45% by wt.), a crosslinker containing at least one silane (0.5 to 4.5% by wt.) and/or a mixture of at least two silanes (0.5 to 9% by wt.) of the general formula Si(R).sub.m(R.sup.a).sub.4-m, where each R.sup.a is selected independently of one another from the group consisting of a hydroxycarboxylic acid ester radical having the general structural formula (I):

(4) ##STR00016##

(5) where

(6) each R.sup.b denotes independently of one another H or an optionally substituted hydrocarbon radical having 1 to 20 carbon atoms, in particular, an optionally substituted, straight chain or branched C1 to C16 alkyl group or an optionally substituted C4 to C14 aryl group,

(7) each R.sup.c denotes independently of one another H or an optionally substituted hydrocarbon radical having 1 to 20 carbon atoms, in particular, an optionally substituted, straight chain or branched C1 to C16 alkyl group or an optionally substituted C4 to C14 aryl group,

(8) R.sup.d denotes an optionally substituted hydrocarbon radical having 1 to 20 carbon atoms, in particular, an optionally substituted, straight chain or branched C1 to C16 alkyl group, an optionally substituted C4 to C14 cycloalkyl group, an optionally substituted C5 to C15 aralkyl group or an optionally substituted C4 to C14 aryl group, Re denotes C or an optionally substituted hydrocarbon radical having 1 to 20 carbon atoms, in particular, an optionally substituted saturated or partially unsaturated cyclic ring system having 4 to 14 C atoms or an optionally substituted aromatic group having 4 to 14 C atoms, and

(9) n is an integer of from 1 to 10, a hydroxycarboxylic acid amide radical having the general structural formula (II):

(10) ##STR00017##

(11) where

(12) each R.sup.n denotes independently of one another H or an optionally substituted hydrocarbon radical having 1 to 20 carbon atoms, in particular, an optionally substituted, straight chain or branched C1 to C16 alkyl group or an optionally substituted C4 to C14 aryl group,

(13) each R.sup.o denotes independently of one another H or an optionally substituted hydrocarbon radical having 1 to 20 carbon atoms, in particular, an optionally substituted, straight chain or branched C1 to C16 alkyl group or an optionally substituted C4 to C14 aryl group,

(14) R.sup.p and R.sup.q denote independently of one another H or an optionally substituted hydrocarbon radical having 1 to 20 carbon atoms, in particular, an optionally substituted, straight chain or branched C1 to C16 alkyl group, an optionally substituted C4 to C14 cycloalkyl group, an optionally substituted C5 to C15 aralkyl group or an optionally substituted C4 to C14 aryl group,

(15) R.sup.r denotes C or an optionally substituted hydrocarbon radical having 1 to 20 carbon atoms, in particular, an optionally substituted saturated or partially unsaturated cyclic ring system having 4 to 14 C atoms or an optionally substituted aromatic group having 4 to 14 C atoms, and

(16) p is an integer of from 1 to 10, a carboxylic acid radical —O—C(O)—R.sup.f, where R.sup.f denotes H or an optionally substituted hydrocarbon radical having 1 to 20 carbon atoms,

(17) in particular, an optionally substituted, straight chain or branched C1 to C16 alkyl group, an optionally substituted C4 to C14 cycloalkyl group or an optionally substituted C4 to C14 aryl group or an optionally substituted C5 to C15 aralkyl group, an oxime radical —O—N═CR.sup.gR.sup.h, where R.sup.g and R.sup.h denote independently of one another H or an optionally substituted hydrocarbon radical having 1 to 20 carbon atoms, in particular, an optionally substituted, straight chain or branched C1 to C16 alkyl group, an optionally substituted C4 to C14 cycloalkyl group or an optionally substituted C4 to C14 aryl group or an optionally substituted C5 to C15 aralkyl group, a carboxylic acid amide radical —N—(R.sup.i)—C(O)—R.sup.j, where R.sup.i denotes H or an optionally substituted hydrocarbon radical having 1 to 20 carbon atoms, in particular, an optionally substituted, straight chain or branched C1 to C16 alkyl group, an optionally substituted C4 to C14 cycloalkyl group or an optionally substituted C4 to C14 aryl group or an optionally substituted C5 to C15 aralkyl group, and RJ denotes H or an optionally substituted hydrocarbon radical having 1 to 20 carbon atoms, in particular, an optionally substituted, straight chain or branched C1 to C16 alkyl group, an optionally substituted C4 to C14 cycloalkyl group or an optionally substituted C4 to C14 aryl group or an optionally substituted C5 to C15 aralkyl group, and an alkoxy radical —OR.sup.k, where R.sup.k denotes an optionally substituted hydrocarbon radical having 1 to 20 carbon atoms, in particular, an optionally substituted, straight chain or branched C1 to C16 alkyl group, an optionally substituted C4 to C14 cycloalkyl group or an optionally substituted C4 to C14 aryl group or an optionally substituted C5 to C15 aralkyl group, were mixed under vacuum. Thereafter, a filler, preferably silica (5 to 15% by wt.), was optionally dispersed therein and stirred under vacuum until the mass was smooth. Then 0.006 to 0.17% by wt. of the catalyst IBU-POSS-Ti-OEt and optionally an adhesion promoter (0.5 to 2% by wt.) were incorporated by mixing under vacuum.

(18) TABLE-US-00002 Component % by wt. 1 α,ω-dihydroxydimethyl-polysiloxane 30 to 70 80,000 cSt 2 polydimethylsiloxane 100 cSt 15 to 45 3 crosslinker 1 0.5 to 4.5 4 crosslinker 2 0.5 to 4.5 5 silica  5 to 15 6 adhesion promoter 0.5 to 2.sup.  7 metal silsesquioxane 0.001 to 0.5 

(19) All of the constituents of the silicone rubber compounds, described above, can be mixed together in one step.

(20) In a preferred embodiment the silicone rubber compounds of the present invention are obtained in one step by way of the intermediately formed prepolymer in only one step. The formation of the prepolymer as well as the subsequent formation of the silicone rubber compounds can be formed in the presence of the catalyst of the invention without an additional purification or intermediate step.

(21) In the case of the examples, described below, all of the parameters were determined by the test methods described below. All of the sealing materials, described below, were transparent and colorless and exhibited proper stability and notch resistance after 24 hours. Furthermore, the following sealing materials of all three test specimens passed in accordance with DIN EN ISO 8340, the conditioning method A on glass at an elongation of 100% of the initial length, with the elongation being maintained for 24 hours.

(22) Comparison of the Tear Strength when Using Catalysts of the Invention (Examples 3 and 4) with Conventional Catalysts (Reference Example):

EXAMPLE 3

(23) Crosslinker Mixture with Oxime Leaving Group

(24) TABLE-US-00003 Component % by wt. 1 α,ω-dihydroxydimethyl-polysiloxane 53.5 80,000 cSt 2 polydimethylsiloxane 100 cSt 30.4 3 vinyl-tris(2-pentanonoximo)silane 2.2 4 methyl-tris(2-pentanonoximo)silane 2.2 5 pyrogenic silica, untreated BET surface 130 to 150 m.sup.2/g 10.6 6 adhesion promoter based on N (2 aminoethyl)-3- 1.0 aminopropyltrimethoxysilane (DAMO) 7 catalyst IBU-POSS-Ti—OEt 0.08

(25) α,ω-dihydroxydimethyl-polysiloxane 80,000 cSt, PDMS 100 cSt and vinyl-tris(2-pentanonoximo)silane were mixed under vacuum. Then methyl-tris(2-pentanonoximo)silane was admixed thereto under vacuum. Thereafter, the silica was dispersed therein and stirred under vacuum until the mass was smooth. Then the catalyst IBU-POSS-Ti-OEt (VII) and the oligomeric adhesion promoter based on N-(2-aminoethyl)-3-aminopropyltrimethoxysilane (DAMO) were incorporated by mixing under vacuum. The product was characterized by a skinning time of 8 minutes and a tack-free time of 20 minutes. The sealing material had good adhesion on all tested materials, i.e., glass, aluminum, PVC, sheet metal, steel, concrete, wood, painted wood, varnished wood, polyamide and Al/Mg alloy.

(26) The determined Shore A hardness was 23. Even after 4 weeks of storage at 60° C., the sealing material was stable (Shore A: 21) and colorless. The extrusion using a 2 mm diameter die at 5 bar and 30 seconds was 14.0. Furthermore the sealing material showed superb properties:

(27) TABLE-US-00004 Property Sealing Material early load bearing capacity .sup. 60 min. complete curing on glass (9 mm) 3 d DIN EN ISO 8339 0.33 tensile stress value at 100% elongation (N/mm.sup.2) DIN EN ISO 8339 0.63 secant modulus at elongation at break (N/mm.sup.2) DIN EN ISO 8339 385% elongation at break DIN EN ISO 7389  92% average elastic recovery DIN 53504 0.89 tear strength (N/mm.sup.2) DIN EN ISO 53504 790% elongation at break

EXAMPLE 4

(28) Crosslinker Mixture with Oxine Leaving Group

(29) TABLE-US-00005 Component % by wt. 1 α.ω dihydroxydimethyl-polysiloxane 53.5 80,000 cSt 2 polydimethylsiloxane 100 cSt 30.4 3 vinyl-tris(2-pentanonoximo)silane 2.2 4 methyl-tris(2-pentanonoximo)silane 2.2 5 pyrogenic silica, untreated BET surface 130 to 150 m.sup.2/g 10.6 6 adhesion promoter based on N (2 aminoethyl)-3- 1.0 aminopropyltrimethoxysilane (DAMO) 7 catalyst IBU-POSS-Ti—OEt 0.08

(30) α,ω-dihydroxydimethyl-polysiloxane 80,000 cSt, PDMS 100 cSt and vinyl-tris(2-pentanonoximo)silane were mixed under vacuum. Then methyl-tris(2-pentanonoximo)silane was admixed thereto under vacuum. Thereafter, the silica was dispersed therein and stirred under vacuum until the mass was smooth. Then the catalyst octyl-POSS-Ti-OEt and the oligomeric adhesion promoter based on N-(2-aminoethyl)-3-aminopropyltrimethoxysilane (DAMO) were incorporated by mixing under vacuum. The product was characterized by a skinning time of 8 minutes and a tack-free time of 20 minutes. The sealing material had good adhesion on all tested materials, i.e., glass, aluminum, PVC, sheet metal, steel, concrete, wood, painted wood, varnished wood, polyamide and Al/Mg alloy.

(31) The determined Shore A hardness was 24. Even after 4 weeks of storage at 60° C., the sealing material was stable (Shore A: 21) and colorless. The extrusion using a 2 mm diameter die at 5 bar and 30 seconds was 12.0 g. Furthermore, the sealing material showed superb properties:

(32) TABLE-US-00006 Property Sealing Material early load bearing capacity 60 min. complete curing on glass (9 mm) 4 d DIN EN ISO 8339 0.38 tensile stress value at 100% elongation (N/mm.sup.2) DIN EN ISO 8339 0.71 secant modulus at elongation at break (N/mm.sup.2) DIN EN ISO 8339 350% elongation at break DIN EN ISO 7389  94% average elastic recovery DIN 53504 0.97 tear strength (N/mm.sup.2) DIN EN ISO 53504 730% elongation at break

REFERENCE EXAMPLE A

(33) Crosslinker Mixture with Oxime Leaving Groups

(34) TABLE-US-00007 Component % by wt. 1 α,ω-dihydroxydimethyl-polysiloxane 53.0 80,000 cSt 2 polydimethylsiloxane 100 cSt 31.4 3 vinyl-tris(2-pentanonoximo)silane 1.3 4 methyl-tris(2-pentanonoximo)silane 3.0 5 pyrogenic silica, untreated BET surface 130 to 150 m.sup.2/g 10.5 6 adhesion promoter based on N (2 aminoethyl)-3- 0.65 aminopropyltrimethoxysilane (DAMO) 7 octyl tin catalyst 0.12
α,ω-dihydroxydimethyl-polysiloxane 80,000 cSt, PDMS 100 cSt and vinyl-tris(2-pentanonoximo)silane were mixed under vacuum. Then methyl-tris(2-acetonoximo)silane was also admixed thereto under vacuum. Thereafter, the silica was dispersed therein and stirred under vacuum until the mass was smooth. Then the octyl tin catalyst and the oligomeric adhesion promoter based on N-(2-aminoethyl)-3-aminopropyltrimethoxysilane (DAMO) were incorporated by mixing under vacuum. The product was characterized by a skinning time of 9 minutes and a tack-free time of 23 minutes. The sealing material had good adhesion on all of the tested materials, i.e., glass, aluminum, PVC, sheet metal, steel, concrete, wood, painted wood, varnished wood, polyamide and Al/Mg alloy.

(35) The determined Shore A hardness was 26. Even after 4 weeks of storage at 60° C., the sealing material was stable (Shore A: 23) and colorless. The extrusion using a 2 mm diameter die at 5 bar and 30 seconds was 18.0 g. Furthermore, the sealing material showed the following properties:

(36) TABLE-US-00008 Property Sealing Material early load bearing capacity 170 min. complete curing on glass (9 mm) 5 d DIN EN ISO 8339 0.38 tensile stress value at 100% elongation (N/mm.sup.2) DIN EN ISO 8339 0.57 secant modulus at elongation at break (N/mm.sup.2) DIN EN ISO 8339 280% elongation at break DIN EN ISO 7389  96% average elastic recovery DIN 53504 0.93 tear strength (N/mm.sup.2) DIN EN ISO 53504 660% elongation at break

(37) Preparation of Individual Silicone Rubber Compounds

EXAMPLE 5

(38) Crosslinker Mixture with Oxime Leaving Group

(39) TABLE-US-00009 Component % by wt. 1 α,ω-dihydroxydimethyl-polysiloxane 53.5 80,000 cSt 2 polydimethylsiloxane 100 cSt 30.4 3 vinyl-tris(2-pentanonoximo)silane 0.85 4 ethyl-tris(acetonoximo)silane 3.55 5 pyrogenic silica, untreated BET surface 130 to 150 m.sup.2/g 10.6 6 oligomeric adhesion promoter based on DAMO 1.0 7 catalyst IBU-POSS-Ti-OEt 0.08

(40) α,ω-dihydroxydimethyl-polysiloxane 80,000 cSt, PDMS 100 cSt, ethyl-tris(acetonoximo)silane and vinyl-tris(2-pentanonoximo)silane were mixed under vacuum. Thereafter, the silica was dispersed therein and stirred under vacuum until the mass was smooth. Then the catalyst IBU-POSS-Ti-Et (VII) and the oligomeric adhesion promoter based on N-(2-aminoethyl)-3-aminopropyltrimethoxysilane (DAMO) were incorporated by mixing under vacuum. The product was transparent and colorless. It was characterized by a skinning time of 10 minutes and a tack-free time of 40 minutes. The sealing material had good adhesion on all of the tested materials, i.e., glass, aluminum, PVC, sheet metal, steel, concrete, wood, painted wood, varnished wood, polyamide and Al/Mg alloy.

(41) The determined Shore A hardness was 22. Even after 4 weeks of storage at 60° C., the scaling material was stable (Shore A: 21) and colorless. The extrusion using a 2 mm diameter die at 5 bar and 30 seconds was 12.0 g. Furthermore, the sealing material showed superb properties:

(42) TABLE-US-00010 Property Sealing Material early load bearing capacity 70 min. complete curing on glass (9 mm) 4 d DIN EN ISO 8339 0.35 tensile stress value at 100% elongation (N/mm.sup.2) DIN EN ISO 8339 0.69 secant modulus at elongation at break (N/mm.sup.2) DIN EN ISO 8339 435% elongation at break DIN EN ISO 7389  93% average elastic recovery DIN 53504 0.83 tear strength (N/mm.sup.2) DIN EN ISO 53504 835% elongation at break

EXAMPLE 6

(43) Crosslinker Mixture with Oxime Leaving Group

(44) TABLE-US-00011 Component % by wt. 1 α,ω-dihydroxydimethyl-polysiloxane 53.5 80,000 cSt 2 polydimethylsiloxane 100 cSt 30.4 3 vinyl-tris(2-pentanonoximo)silane 2.2 4 methyl-tris(2-pentanonoximo)silane 2.2 5 pyrogenic silica, untreated BET surface 130 to 150 m.sup.2/g 10.6 6 oligomeric adhesion promoter based on DAMO 1.0 7 catalyst IBU-POSS-Ti-OEt 0.006

(45) α,ω-dihydroxydimethyl-polysiloxane 80,000 cSt, PDMS 100 cSt and vinyl-tris(2-pentanonoximo)silane were mixed under vacuum. Then methyl-tris(2-pentanonoximo)silane was admixed thereto under vacuum. Thereafter, the silica was dispersed therein and stirred under vacuum until the mass was smooth. Then the catalyst IBU-POSS-Ti-OEt (VII) and the oligomeric adhesion promoter based on N-(2-aminoethyl)-3-aminopropyltrimethoxysilane (DAMO) were incorporated by mixing under vacuum. The product was transparent and colorless. It was characterized by a skinning time of 8 minutes and a tack-free time of 30 minutes. The sealing material had good adhesion on all of the tested materials, i.e., glass, aluminum, PVC, sheet metal, steel, concrete, wood, painted wood, varnished wood, polyamide and Al/Mg alloy.

(46) The determined Shore A hardness was 26. Even after 4 weeks of storage at 60° C., the sealing material was stable (Shore A: 24) and colorless. The extrusion using a 2 mm diameter die at 5 bar and 30 seconds was 12.0 g. Furthermore, the sealing material showed superb properties:

(47) TABLE-US-00012 Property Sealing Material Early load bearing capacity 60 min. Complete curing on glass (9 mm) 3 d DIN EN ISO 8339 0.38 Tensile stress value at 100% elongation (N/mm.sup.2) DIN EN ISO 8339 0.68 secant modulus at elongation at break (N/mm.sup.2) DIN EN ISO 8339 340% elongation at break DIN EN ISO 7389  95% average elastic recovery DIN 53504 0.68 Tear strength (N/mm.sup.2) DIN EN ISO 53504 555% elongation at break

EXAMPLE 7

(48) Crosslinker with Carboxylic Acid Leaving Group

(49) TABLE-US-00013 Component % by wt. 1 α,ω-dihydroxydimethyl-polysiloxane 55.4 80,000 cSt 2 polydimethylsiloxane 100 cSt 31.1 3 propyltriacetoxysilane 4.5 4 di-tertbutoxy-diacetoxysilane BDAC 0.25 5 pyrogenic silica, untreated BET surface 130 to 150 m.sup.2/g 8.5 6 catalyst IBU-POSS-Ti-OEt 0.04

(50) Polymer 80,000 cSt, PDMS 100 cSt and propyltriacetoxysilane were mixed under vacuum. Then the adhesion promoter BDAC was also admixed thereto under vacuum. Thereafter, the silica was dispersed therein and stirred under vacuum until the mass was smooth. Then the catalyst IBU-POSS-Ti-OEt (VII) was incorporated by mixing under vacuum. The product was transparent and colorless. It was characterized by a skinning time of minutes and a tack-free time of 40 minutes. The scaling material had good adhesion on all of the tested materials, i.e., glass, aluminum, PVC, sheet metal, steel, [sic] wood, painted wood, varnished wood, polyamide and Al/Mg alloy.

(51) The determined Shore A hardness was 23. Even after 4 weeks of storage at 60° C., the sealing material was stable (Shore A: 23) and colorless. The extrusion using a 2 mm diameter die at 5 bar and 30 seconds was 25.0 g. Furthermore, the sealing material showed superb properties:

(52) TABLE-US-00014 Property Sealing Material early load bearing capacity 40 min. complete curing on glass (9 mm) 3 d DIN EN ISO 8339 0.37 tensile stress value at 100% elongation (N/mm.sup.2) DIN EN ISO 8339 0.49 secant modulus at elongation at break (N/mm.sup.2) DIN EN ISO 8339 210% elongation at break DIN EN ISO 8340 24 h/100% elongation at break, conditioning method A on glass all 3 test specimens passed DIN EN ISO 7389  97% average elastic recovery DIN 53504 1.24 tear strength (N/mm.sup.2) DIN EN ISO 53504 1150%  elongation at break

EXAMPLE 8

(53) Crosslinker with Carboxylic Acid Leaving Group

(54) TABLE-US-00015 Component % by wt. 1 α,ω-dihydroxydimethyl-polysiloxane 55.4 80,000 cSt 2 polydimethylsiloxane 100 cSt 31.1 3 propyltriacetoxysilane 4.5 4 di-tertbutoxy-diacetoxysilane BDAC 0.25 5 pyrogenic silica, untreated BET surface 130 to 150 m.sup.2/g 8.5 6 catalyst IBU-POSS-Ti-OEt 0.0125

(55) α,ω-dihydroxydimethyl-polysiloxane 80,000 cSt, PDMS 100 cSt and propyltriacetoxysilane were mixed under vacuum. Then the adhesion promoter BDAC was also admixed thereto under vacuum. Thereafter, the silica was dispersed therein and stirred under vacuum until the mass was smooth. Then the catalyst IBU-POSS-Ti-OEt (VII) was incorporated by mixing under vacuum. The product was transparent and colorless. It was characterized by a skinning time of 8 minutes and a tack-free time of 40 minutes. The sealing material had good adhesion on all of the tested materials, i.e., glass, aluminum, PVC, sheet metal, steel, wood, painted wood, varnished wood, polyamide and Al/Mg alloy.

(56) The determined Shore A hardness was 23. Even after 4 weeks of storage at 60° C., the sealing material was stable (Shore A: 23) and colorless. The extrusion using a 2 mm diameter die at 5 bar and 30 seconds was 25.0 g. Furthermore, the sealing material showed superb properties:

(57) TABLE-US-00016 Property Sealing Material early load bearing capacity 40 min. complete curing on glass (9 mm) 3 d DIN EN ISO 8339 0.37 Tensile stress value at 100% elongation (N/mm.sup.2) DIN EN ISO 8339 0.49 secant modulus at elongation at break (N/mm.sup.2) DIN EN ISO 8339 210% elongation at break DIN EN ISO 7389  97% average elastic recovery DIN 53504 1.24 tear strength (N/mm.sup.2) DIN EN ISO 53504 1150%  elongation at break

EXAMPLE 9

(58) Crosslinker with Hydroxycarboxylic Acid Leaving Groups

(59) TABLE-US-00017 Component % by wt. 1 α,ω-dihydroxydimethyl-polysiloxane 55.0 80,000 cSt 2 polydimethylsiloxane 100 cSt 26.7 3 methyl-tris salicylic acid ethylhexyl ester silane 4.0 4 propyl-tris salicylic acid ethylhexyl ester silane 4.0 5 3 aminopropyltriethoxysilane (AMEO) 0.1 6 pyrogenic silica, untreated BET surface 130 to 150 m.sup.2/g 8.5 7 catalyst IBU-POSS-Ti-OEt 0.07 8 tris(3 trimethoxysilylpropyl)isocyanurate 1.2 9 DMAPTMS 0.4

(60) α,ω-dihydroxydimethyl-polysiloxane 80,000 cSt, PDMS 100 cSt, methyl-tris-salicylic acid ethylhexyl ester silane and propyl-tris-salicylic acid ethylhexyl ester silane were mixed under vacuum. Then AMEO was also admixed thereto under vacuum. Thereafter, the silica was dispersed therein and stirred under vacuum until the mass was smooth. Then the catalyst IBU-POSS-Ti-OEt (VII) and the adhesion promoter tris(3-trimethoxysilylpropyl)isocyanurate and the adhesion promoter dimethylaminopropyltrimethoxysilane (DMAPTMS) were incorporated by mixing under vacuum.

(61) The product was characterized by a skinning time of 7 minutes and a tack-free time of 120 minutes. The sealing material had good adhesion on all tested materials, i.e., glass, aluminum, PVC, sheet metal, steel, wood, painted wood, varnished wood, polyamide and Al/Mg alloy.

(62) The determined Shore A hardness was 27. Even after 4 weeks of storage at 60° C., the sealing material was stable (Shore A: 24) and colorless. The extrusion using a 2 mm diameter die at 5 bar and 30 seconds was 12.0 g. Furthermore, the sealing material showed superb properties:

(63) TABLE-US-00018 Property Sealing Material early load bearing capacity 20 min. complete curing on glass (9 mm) 5 d DIN EN ISO 8339 0.33 tensile stress value at 100% elongation (N/mm.sup.2) DIN EN ISO 8339 0.52 secant modulus at elongation at break (N/mm.sup.2) DIN EN ISO 8339 285% elongation at break DIN EN ISO 7389  96% average elastic recovery DIN 53504 0.57 tear strength (N/mm.sup.2) DIN EN ISO 53504 460% elongation at break

REFERENCE EXAMPLE B

(64) I) Starting Materials:

(65) TABLE-US-00019 Substance Amount (g) 1 Polymer 20,000 cSt 380 (α,ω-dihydroxy-dimethyl-polysiloxane) 2 Crosslinker: tetra(glycolic acid n-butyl ester)silane* 5 7 Catalyst: amberlite IRA-67 (weak anion exchange 0.4 resin with a gel type acrylic matrix *Synthesis of Tetra(glycolic acid n-butyl ester)silane A 1,000 ml three-necked flask is filled with 222 g of toluene, 67.6 g of triethylamine and 90.6 g of glycolic acid n-butyl ester under a nitrogen atmosphere. Then 26.8 g of tetrachlorosilane are metered in with stirring. In this case the reaction temperature is maintained at <35° C. by cooling with a water bath. Upon metering, the mixture is stirred for an additional 30 min. at 30° C., and then the hydrochloride that was formed is removed by filtration. Then lastly the solvent toluene is separated by distillation in vacuo. 86 g (98.5% of the theoretical value) of a yellowish liquid, which consists largely of Si(OCH2COO-n-C4H9)4, are obtained.

(66) II) Preparation:

(67) Polymer 80,000, crosslinker and catalyst are mixed under vacuum. The resulting mixture is then tapped under exclusion of atmospheric moisture.

(68) Properties of the Sealing Material after Exposure to Air.

(69) TABLE-US-00020 Optical characteristics Colorless, transparent Skinning time 40 min. Tack-free time more than 7 days

(70) More in-depth studies could not be conducted, since the mixture does not cure completely.

(71) General Implementation of the Test Methods:

(72) 1. Determining the Tack-Free Time of Silicone Sealing Materials

(73) In order to determine the tack-free time, the temperature as well as the atmospheric moisture when dispensing the sealing material must be determined by means of a suitable device and recorded in the appropriate protocol. A filled and sealed cartridge that is ready for use (service life of the sealing material after compounding for at least 24 hours) is inserted into a gun for silicone cartridges. Then an appropriate amount of silicone is sprayed on a clean glass plate. The silicone is spread promptly with the trowel, so that a continuous silicone strip is formed. The current time is read. At appropriate intervals the tack-free time of the sealing material to be determined is determined by gently touching the silicone surface with a clean finger. If the sealing material is tack-free, then the current time is read again.

(74) 2. Determining the Extrusion of Silicone Sealing Materials

(75) A filled and sealed cartridge that is ready for use (service life of the sealing material after compounding for at least 24 hours) is inserted into a compressed air gun for silicone cartridges, and a suitable cartridge tip is screwed on. The compressed air gun is connected to the compressed air supply; and the pressure gauge is set to a pressure of 5 bar. Then a small amount of silicone is sprayed on a wiping paper from the silicone cartridge, so that the cartridge tip is filled completely with silicone. Then an aluminum bowl is placed on the top-loading balance and tared. Now silicone is sprayed on the bowl for exactly 30 seconds, and then lastly the weight is read on the top-loading balance.

(76) 3. Determining the Stability of Silicone Sealing Materials

(77) In order to determine the stability, the temperature as well as the atmospheric moisture when dispensing the sealing material must be determined by means of a suitable device and recorded in the appropriate protocol. A filled and sealed cartridge that is ready for use (service life of the sealing material after compounding for at least 24 hours) is inserted into a gun for silicone cartridges. Then a worm shape is sprayed on a cardboard (diameter approx. 3 cm) in a circular manner. The cardboard with the silicone worm is now placed vertically, and the current time is read.

(78) After 30 minutes, it is observed whether the silicone worm has the original shape or whether the worm has flowed downwards. If the worm shape has not changed, then the silicone sealing material is stable.

(79) 4. Determining the Complete Curing of Silicone Sealing Materials

(80) In order to determine the complete curing, the temperature as well as the atmospheric moisture when dispensing the sealing material must be determined by means of a suitable device and recorded in the appropriate protocol. A filled and sealed cartridge that is ready for use (service life of the sealing material after compounding for at least 24 hours) is inserted into a gun for silicone cartridges. Then an appropriate amount of silicone is sprayed on a clean glass plate. The silicone is spread promptly with the trowel, so that a continuous silicone strip is formed. At appropriate intervals (days) a small crosspiece is carefully cut off from the silicone with a knife, and the curing of the sealing material is assessed. If the inner portion of the body of the sealing material is still sticky and gel-like, then the sealing material has still not cured completely, and the determination procedure is repeated. If the sealing material has cured completely, then the curing time is recorded in days. If the sealing material is still sticky after 7 days after dispensing, then the criterion regarding the complete curing shall be judged to be deficient.

(81) 5. Determining the Adhesion of Silicone Sealing Materials

(82) In order to determine the adhesion, the temperature as well as the atmospheric moisture when dispensing the sealing material must be determined by means of a suitable device and recorded in the appropriate protocol. A filled and sealed cartridge that is ready for use (service life of the sealing material after compounding for at least 24 hours) is inserted into a gun for silicone cartridges. Then a silicone button is sprayed on a suitably cleaned carrier material (for example, glass, aluminum, wood, plastic, concrete, natural stone, etc.). After the sealing material has cured completely (about 48 h), the silicone button is pulled with the fingers to see whether the silicone has peeled off again from the carrier material or whether the silicone has formed an intimate bond with the carrier material. If the silicone button can be easily peeled off or can be pulled off only with difficulty or not at all from the carrier material, then the adhesive property shall be rated as bad, average or good.

(83) 6. Determining the Odor of Silicone Sealing Materials

(84) A filled and sealed cartridge that is ready for use (service life of the sealing material after compounding for at least 24 hours) is inserted into a gun for silicone cartridges. Then an appropriate amount of silicone is sprayed on a clean glass plate. The silicone is spread promptly with the trowel, so that a continuous silicone strip is formed. Then the silicone sealing material is assessed with respect to its odor.

(85) 7. Determining the Aspect of Silicone Sealing Materials

(86) A filled and sealed cartridge that is ready for use (service life of the sealing material after compounding for at least 24 hours) is inserted into a gun for silicone cartridges. Then an appropriate amount of silicone is sprayed on a clean glass plate. The silicone is spread promptly with the trowel, so that a continuous silicone strip is formed. Then the silicone sealing material is assessed by visual inspection for appearance, color and smoothness.

(87) 8. Determining the Skinning Time of Silicone Sealing Materials

(88) In order to determine the skinning time, the temperature as well as the atmospheric moisture when dispensing the sealing material must be determined by means of a suitable device and recorded in the appropriate protocol. A filled and sealed cartridge that is ready for use (service life of the sealing material after compounding for at least 24 hours) is inserted into a gun for silicone cartridges. Then an appropriate amount of silicone is sprayed on a clean glass plate. The silicone is spread promptly with the trowel, so that a continuous silicone strip is formed. At appropriate intervals the skinning of the sealing material to be determined is determined with a clean finger by applying a slight pressure on the silicone surface. If the sealing material forms a skin on its surface, so that no silicone residues will stick to the finger, then the measured time is read on the stopwatch.

(89) 9. Tensile Test with Dumbbell Specimen S1 in Accordance with DIN 53504

(90) In order to determine the silicone to be tested, the associated test number of the silicone cartridge and the test date must be recorded in the protocol. The service life of the sealing material after compounding must be at least 24 hours in the cartridge. The mold is wetted with detergent to prevent silicone buildup on the metal. A filled and sealed cartridge that is ready for use is inserted into a gun for silicone cartridges. The tip of the cartridge is removed. Then the silicone is sprayed on the die for the dumbbell specimen S 1 over the length and height of the milled mold and immediately smoothed out with a trowel. After at least 24 hours the curing of the silicone is checked by lifting the test specimen from the die. The surface must no longer be sticky. The dumbbell specimen has to be visually flawless without air pockets or inclusions of foreign matter and without cracks. After removal from die, the test specimen is marked with the test number. In the tensile tester T 300, the tension clamps have to be used for the dumbbell specimen S 1. The testable dumbbell specimen is clamped between the upper and lower clamps in such a way that the bar indicates exactly 26 mm of initial length to be measured. The measured data or, more specifically, the measuring marks are reset to zero in the relaxed state. By pressing the start button, the elongation of the test specimens or, more specifically, the display of their measured value begins. The device shuts off automatically after the test specimen tears. The measured values remain displayed and can be read directly.

(91) 10. Tensile Test with H Test Specimen in Accordance with DIN 8339

(92) In order to determine the silicone to be tested, the associated test number of the silicone cartridge and the test date must be recorded in the protocol. The service life of the sealing material after compounding must be at least 24 hours in the cartridge.

(93) A filled and sealed cartridge that is ready for use is inserted into a gun for silicone cartridges. The tip of the cartridge is removed. Then the silicone is sprayed on the die over the length and height of the milled mold and immediately smoothed out with a trowel. Thereafter the test specimen is stored for 28 days under standard conditions. Before the tensile test, the test specimen is checked by visual inspection. The test specimen may not show any air pockets or cracks.

(94) In the tensile tester MFC T 300, the tension clamps have to be used for the H test specimen. The test piece is clamped between the upper and lower clamps in such a way that the distance is 12 mm. The measured data or, more specifically, the measuring marks are reset to zero in the relaxed state. By pressing the start button, the elongation of the test specimens or, more specifically, the display of their measured value begins.

(95) The device shuts off automatically after the test specimen tears. The measured values remain displayed and can be read directly.

(96) 11. Tensile Test with H Test Specimen in accordance with DIN 8340

(97) In order to determine the silicone to be tested, the associated test number of the silicone cartridge and the test date must be recorded in the protocol. The service life of the sealing material after compounding must be at least 24 hours in the cartridge. A filled and sealed cartridge that is ready for use is inserted into a gun for silicone cartridges. The tip of the cartridge is removed. Then the silicone is sprayed on the die over the length and height of the mold and immediately smoothed out with a trowel. Thereafter the test specimen is stored for 28 days under standard conditions. Before the tensile test, the test specimen is checked by visual inspection. The test specimen may not show any air pockets or cracks.

(98) In the tensile tester MFC T 300, the tension clamps have to be used for the H test specimen. The test piece is clamped between the upper and lower clamps in such a way that the distance is 12 mm. The measured data or, more specifically, the measuring marks are reset to zero in the relaxed state. By pressing the start button, the elongation of the test specimens or, more specifically, the display of their measured value begins. The device shuts off automatically after the test specimen tears. The measured values remain displayed and can be read directly.

(99) 12. Determining the Storage Stability of Silicone Sealing Materials

(100) A filled and sealed cartridge that is ready for use is placed in the heated drying oven. According to the test method protocol, the silicone sealing material is stored in the heated drying oven at a suitable temperature for a specified period of several weeks. When the storage time has elapsed, the cartridge is inserted into a gun for silicone cartridges. Then an appropriate amount of silicone is sprayed on an absorbent pad that has been laid out. The silicone is spread promptly with the trowel, so that a continuous silicone strip is formed. The silicone sealing material is then assessed for PA-E0002 and PA-E0010.

(101) 13. Determining the Early Load Bearing Capacity of Silicone Sealing Materials

(102) In order to determine the early load bearing capacity, the temperature as well as the atmospheric moisture when dispensing the sealing material must be determined by means of a suitable device and recorded in the appropriate protocol. A filled and sealed cartridge that is ready for use (service life of the sealing material after compounding for at least 24 hours) is inserted into a gun for silicone cartridges. Then horizontal lines are drawn on the cardboard at intervals of 3 cm and then cut. Then an appropriate amount of silicone is sprayed on the cardboard. The silicone is spread promptly with the trowel, so that a continuous silicone strip is formed. The current time is read. At equal intervals of 15 minutes the cardboard is bent to form a right angle, starting at the first line; and the surface of the silicone is evaluated at the kink point. If the silicone is completely or only partially cracked at the kink point, the determination procedure is repeated at the next 3 cm line after 15 more minutes. If the silicone is elastic at the kink point and no crack is detectable, then the silicone can be subjected to a load at an early stage. The current time is read again.

(103) 14. Determining the Shore Hardness of Silicone Sealing Materials

(104) A filled and sealed cartridge that is ready for use (service life of the sealing material after compounding for at least 24 hours) is inserted into a gun for silicone cartridges. Then an appropriate amount of silicone is sprayed on a clean glass plate. The silicone is spread promptly with the trowel, so that a continuous silicone strip is formed. In the case of a fully cured sealing material (see PA-E0008), the Shore hardness determination device is placed with both hands totally flat on the silicone surface, and the maximum value of the Shore hardness is read. The measurement is repeated at least 5 times at various points on the silicone surface, and an average of the individual measurements is formed.