GB2335660A - High viscosity diluent gum for heat cured alkenyl-siloxanes - Google Patents
High viscosity diluent gum for heat cured alkenyl-siloxanes Download PDFInfo
- Publication number
- GB2335660A GB2335660A GB9916039A GB9916039A GB2335660A GB 2335660 A GB2335660 A GB 2335660A GB 9916039 A GB9916039 A GB 9916039A GB 9916039 A GB9916039 A GB 9916039A GB 2335660 A GB2335660 A GB 2335660A
- Authority
- GB
- United Kingdom
- Prior art keywords
- weight
- parts
- vinyl
- gum
- alkenyl
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 239000003085 diluting agent Substances 0.000 title claims abstract description 11
- 125000000391 vinyl group Chemical group [H]C([*])=C([H])[H] 0.000 claims abstract description 99
- 229920002554 vinyl polymer Polymers 0.000 claims abstract description 97
- 239000000203 mixture Substances 0.000 claims abstract description 74
- 125000003342 alkenyl group Chemical group 0.000 claims abstract description 49
- 229920001296 polysiloxane Polymers 0.000 claims abstract description 36
- 150000002978 peroxides Chemical class 0.000 claims abstract description 16
- 239000003795 chemical substances by application Substances 0.000 claims abstract description 13
- 229920002379 silicone rubber Polymers 0.000 claims abstract description 13
- 229910052799 carbon Inorganic materials 0.000 claims description 23
- 125000001997 phenyl group Chemical group [H]C1=C([H])C([H])=C(*)C([H])=C1[H] 0.000 claims description 19
- 125000000217 alkyl group Chemical group 0.000 claims description 18
- 125000000725 trifluoropropyl group Chemical group [H]C([H])(*)C([H])([H])C(F)(F)F 0.000 claims description 18
- 125000004122 cyclic group Chemical group 0.000 claims description 8
- 239000004945 silicone rubber Substances 0.000 claims description 5
- 125000004432 carbon atom Chemical group C* 0.000 claims 4
- -1 polysiloxane Polymers 0.000 abstract description 22
- 229920001971 elastomer Polymers 0.000 description 41
- 239000005060 rubber Substances 0.000 description 41
- 239000000945 filler Substances 0.000 description 37
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 36
- 238000002156 mixing Methods 0.000 description 35
- 229910021485 fumed silica Inorganic materials 0.000 description 26
- 230000000704 physical effect Effects 0.000 description 26
- XLOMVQKBTHCTTD-UHFFFAOYSA-N Zinc monoxide Chemical compound [Zn]=O XLOMVQKBTHCTTD-UHFFFAOYSA-N 0.000 description 22
- 238000007906 compression Methods 0.000 description 22
- 230000006835 compression Effects 0.000 description 22
- 125000002887 hydroxy group Chemical group [H]O* 0.000 description 21
- 150000001721 carbon Chemical group 0.000 description 19
- 238000001723 curing Methods 0.000 description 18
- 239000003054 catalyst Substances 0.000 description 16
- 150000003254 radicals Chemical class 0.000 description 16
- 238000009472 formulation Methods 0.000 description 15
- 229920005989 resin Polymers 0.000 description 15
- 239000011347 resin Substances 0.000 description 15
- 229920001577 copolymer Polymers 0.000 description 13
- VLKZOEOYAKHREP-UHFFFAOYSA-N n-Hexane Chemical compound CCCCCC VLKZOEOYAKHREP-UHFFFAOYSA-N 0.000 description 13
- 238000011282 treatment Methods 0.000 description 13
- 239000000395 magnesium oxide Substances 0.000 description 11
- CPLXHLVBOLITMK-UHFFFAOYSA-N magnesium oxide Inorganic materials [Mg]=O CPLXHLVBOLITMK-UHFFFAOYSA-N 0.000 description 11
- AXZKOIWUVFPNLO-UHFFFAOYSA-N magnesium;oxygen(2-) Chemical compound [O-2].[Mg+2] AXZKOIWUVFPNLO-UHFFFAOYSA-N 0.000 description 11
- 125000002496 methyl group Chemical group [H]C([H])([H])* 0.000 description 11
- 239000011787 zinc oxide Substances 0.000 description 11
- 239000000654 additive Substances 0.000 description 10
- UNJPQTDTZAKTFK-UHFFFAOYSA-K cerium(iii) hydroxide Chemical compound [OH-].[OH-].[OH-].[Ce+3] UNJPQTDTZAKTFK-UHFFFAOYSA-K 0.000 description 10
- 239000004205 dimethyl polysiloxane Substances 0.000 description 10
- 239000012530 fluid Substances 0.000 description 10
- WTFXARWRTYJXII-UHFFFAOYSA-N iron(2+);iron(3+);oxygen(2-) Chemical compound [O-2].[O-2].[O-2].[O-2].[Fe+2].[Fe+3].[Fe+3] WTFXARWRTYJXII-UHFFFAOYSA-N 0.000 description 10
- SZVJSHCCFOBDDC-UHFFFAOYSA-N iron(II,III) oxide Inorganic materials O=[Fe]O[Fe]O[Fe]=O SZVJSHCCFOBDDC-UHFFFAOYSA-N 0.000 description 10
- 229920000435 poly(dimethylsiloxane) Polymers 0.000 description 10
- KPUWHANPEXNPJT-UHFFFAOYSA-N disiloxane Chemical class [SiH3]O[SiH3] KPUWHANPEXNPJT-UHFFFAOYSA-N 0.000 description 9
- 238000000034 method Methods 0.000 description 9
- DMWVYCCGCQPJEA-UHFFFAOYSA-N 2,5-bis(tert-butylperoxy)-2,5-dimethylhexane Chemical compound CC(C)(C)OOC(C)(C)CCC(C)(C)OOC(C)(C)C DMWVYCCGCQPJEA-UHFFFAOYSA-N 0.000 description 7
- 239000004614 Process Aid Substances 0.000 description 7
- 238000007789 sealing Methods 0.000 description 7
- 239000000126 substance Substances 0.000 description 7
- 230000014759 maintenance of location Effects 0.000 description 6
- 239000000463 material Substances 0.000 description 6
- 239000012763 reinforcing filler Substances 0.000 description 6
- UQSXHKLRYXJYBZ-UHFFFAOYSA-N Iron oxide Chemical compound [Fe]=O UQSXHKLRYXJYBZ-UHFFFAOYSA-N 0.000 description 5
- 230000000694 effects Effects 0.000 description 5
- FFUAGWLWBBFQJT-UHFFFAOYSA-N hexamethyldisilazane Chemical compound C[Si](C)(C)N[Si](C)(C)C FFUAGWLWBBFQJT-UHFFFAOYSA-N 0.000 description 5
- 239000003921 oil Substances 0.000 description 5
- 125000005372 silanol group Chemical group 0.000 description 5
- 239000000377 silicon dioxide Substances 0.000 description 5
- GWEVSGVZZGPLCZ-UHFFFAOYSA-N Titan oxide Chemical compound O=[Ti]=O GWEVSGVZZGPLCZ-UHFFFAOYSA-N 0.000 description 4
- 238000011065 in-situ storage Methods 0.000 description 4
- 238000004519 manufacturing process Methods 0.000 description 4
- 239000006082 mold release agent Substances 0.000 description 4
- SCPYDCQAZCOKTP-UHFFFAOYSA-N silanol Chemical compound [SiH3]O SCPYDCQAZCOKTP-UHFFFAOYSA-N 0.000 description 4
- 238000005004 MAS NMR spectroscopy Methods 0.000 description 3
- 150000001875 compounds Chemical class 0.000 description 3
- 238000011161 development Methods 0.000 description 3
- 230000018109 developmental process Effects 0.000 description 3
- 238000006459 hydrosilylation reaction Methods 0.000 description 3
- 239000003999 initiator Substances 0.000 description 3
- 230000000977 initiatory effect Effects 0.000 description 3
- QJGQUHMNIGDVPM-UHFFFAOYSA-N nitrogen group Chemical group [N] QJGQUHMNIGDVPM-UHFFFAOYSA-N 0.000 description 3
- HMMGMWAXVFQUOA-UHFFFAOYSA-N octamethylcyclotetrasiloxane Chemical compound C[Si]1(C)O[Si](C)(C)O[Si](C)(C)O[Si](C)(C)O1 HMMGMWAXVFQUOA-UHFFFAOYSA-N 0.000 description 3
- 238000006116 polymerization reaction Methods 0.000 description 3
- 239000002243 precursor Substances 0.000 description 3
- 239000000047 product Substances 0.000 description 3
- 230000005855 radiation Effects 0.000 description 3
- 238000010058 rubber compounding Methods 0.000 description 3
- 239000002904 solvent Substances 0.000 description 3
- 238000012360 testing method Methods 0.000 description 3
- QXQOIUZWCJIMEY-UHFFFAOYSA-N 2,2-bis(tert-butylperoxy)-3-methylheptane Chemical compound CCCCC(C)C(C)(OOC(C)(C)C)OOC(C)(C)C QXQOIUZWCJIMEY-UHFFFAOYSA-N 0.000 description 2
- OMPJBNCRMGITSC-UHFFFAOYSA-N Benzoylperoxide Chemical compound C=1C=CC=CC=1C(=O)OOC(=O)C1=CC=CC=C1 OMPJBNCRMGITSC-UHFFFAOYSA-N 0.000 description 2
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 2
- 239000004606 Fillers/Extenders Substances 0.000 description 2
- 238000006482 condensation reaction Methods 0.000 description 2
- 230000007812 deficiency Effects 0.000 description 2
- 238000010894 electron beam technology Methods 0.000 description 2
- 230000008030 elimination Effects 0.000 description 2
- 238000003379 elimination reaction Methods 0.000 description 2
- 238000013007 heat curing Methods 0.000 description 2
- 238000010438 heat treatment Methods 0.000 description 2
- 239000003112 inhibitor Substances 0.000 description 2
- 238000005259 measurement Methods 0.000 description 2
- 229910052751 metal Inorganic materials 0.000 description 2
- 239000002184 metal Substances 0.000 description 2
- 125000000956 methoxy group Chemical group [H]C([H])([H])O* 0.000 description 2
- 239000002245 particle Substances 0.000 description 2
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Chemical compound [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 description 2
- 229920000642 polymer Polymers 0.000 description 2
- 238000012545 processing Methods 0.000 description 2
- 230000001698 pyrogenic effect Effects 0.000 description 2
- 150000004819 silanols Chemical class 0.000 description 2
- 229920002050 silicone resin Polymers 0.000 description 2
- 239000007787 solid Substances 0.000 description 2
- SRVJKTDHMYAMHA-WUXMJOGZSA-N thioacetazone Chemical compound CC(=O)NC1=CC=C(\C=N\NC(N)=S)C=C1 SRVJKTDHMYAMHA-WUXMJOGZSA-N 0.000 description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 2
- IMGVXSGKBGOBPV-UHFFFAOYSA-N 1,1-bis(tert-butylperoxy)-2,2,3-trimethylcyclohexane Chemical compound CC1CCCC(OOC(C)(C)C)(OOC(C)(C)C)C1(C)C IMGVXSGKBGOBPV-UHFFFAOYSA-N 0.000 description 1
- QPLDLSVMHZLSFG-UHFFFAOYSA-N Copper oxide Chemical compound [Cu]=O QPLDLSVMHZLSFG-UHFFFAOYSA-N 0.000 description 1
- 239000005751 Copper oxide Substances 0.000 description 1
- XDTMQSROBMDMFD-UHFFFAOYSA-N Cyclohexane Chemical compound C1CCCCC1 XDTMQSROBMDMFD-UHFFFAOYSA-N 0.000 description 1
- 239000005977 Ethylene Substances 0.000 description 1
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 1
- 239000005909 Kieselgur Substances 0.000 description 1
- 229910020447 SiO2/2 Inorganic materials 0.000 description 1
- 229910020485 SiO4/2 Inorganic materials 0.000 description 1
- BLRPTPMANUNPDV-UHFFFAOYSA-N Silane Chemical compound [SiH4] BLRPTPMANUNPDV-UHFFFAOYSA-N 0.000 description 1
- 229910002808 Si–O–Si Inorganic materials 0.000 description 1
- NINIDFKCEFEMDL-UHFFFAOYSA-N Sulfur Chemical compound [S] NINIDFKCEFEMDL-UHFFFAOYSA-N 0.000 description 1
- 230000000996 additive effect Effects 0.000 description 1
- 229910052915 alkaline earth metal silicate Inorganic materials 0.000 description 1
- 125000003545 alkoxy group Chemical group 0.000 description 1
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 1
- 150000001450 anions Chemical class 0.000 description 1
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 1
- 125000003236 benzoyl group Chemical group [H]C1=C([H])C([H])=C(C([H])=C1[H])C(*)=O 0.000 description 1
- 150000001639 boron compounds Chemical class 0.000 description 1
- 150000001768 cations Chemical class 0.000 description 1
- CETPSERCERDGAM-UHFFFAOYSA-N ceric oxide Chemical compound O=[Ce]=O CETPSERCERDGAM-UHFFFAOYSA-N 0.000 description 1
- 229940044927 ceric oxide Drugs 0.000 description 1
- 229910000422 cerium(IV) oxide Inorganic materials 0.000 description 1
- DPUCLPLBKVSJIB-UHFFFAOYSA-N cerium;tetrahydrate Chemical compound O.O.O.O.[Ce] DPUCLPLBKVSJIB-UHFFFAOYSA-N 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 239000007809 chemical reaction catalyst Substances 0.000 description 1
- 229910052681 coesite Inorganic materials 0.000 description 1
- 239000002131 composite material Substances 0.000 description 1
- 239000000470 constituent Substances 0.000 description 1
- 229910000431 copper oxide Inorganic materials 0.000 description 1
- 229910052906 cristobalite Inorganic materials 0.000 description 1
- 238000004132 cross linking Methods 0.000 description 1
- 239000003431 cross linking reagent Substances 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000006356 dehydrogenation reaction Methods 0.000 description 1
- 230000001419 dependent effect Effects 0.000 description 1
- OLLFKUHHDPMQFR-UHFFFAOYSA-N dihydroxy(diphenyl)silane Chemical compound C=1C=CC=CC=1[Si](O)(O)C1=CC=CC=C1 OLLFKUHHDPMQFR-UHFFFAOYSA-N 0.000 description 1
- 239000006185 dispersion Substances 0.000 description 1
- 230000009189 diving Effects 0.000 description 1
- 230000009977 dual effect Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000011066 ex-situ storage Methods 0.000 description 1
- 239000012467 final product Substances 0.000 description 1
- 239000007789 gas Substances 0.000 description 1
- 239000000499 gel Substances 0.000 description 1
- 229920006158 high molecular weight polymer Polymers 0.000 description 1
- 239000001257 hydrogen Substances 0.000 description 1
- 229910052739 hydrogen Inorganic materials 0.000 description 1
- 230000002209 hydrophobic effect Effects 0.000 description 1
- 230000005764 inhibitory process Effects 0.000 description 1
- 229910052909 inorganic silicate Inorganic materials 0.000 description 1
- 230000002045 lasting effect Effects 0.000 description 1
- 150000004668 long chain fatty acids Chemical class 0.000 description 1
- 239000011159 matrix material Substances 0.000 description 1
- 229910052976 metal sulfide Inorganic materials 0.000 description 1
- WCYWZMWISLQXQU-UHFFFAOYSA-N methyl Chemical compound [CH3] WCYWZMWISLQXQU-UHFFFAOYSA-N 0.000 description 1
- 239000010445 mica Substances 0.000 description 1
- 229910052618 mica group Inorganic materials 0.000 description 1
- 238000003801 milling Methods 0.000 description 1
- 238000000465 moulding Methods 0.000 description 1
- 210000002445 nipple Anatomy 0.000 description 1
- VIKNJXKGJWUCNN-XGXHKTLJSA-N norethisterone Chemical compound O=C1CC[C@@H]2[C@H]3CC[C@](C)([C@](CC4)(O)C#C)[C@@H]4[C@@H]3CCC2=C1 VIKNJXKGJWUCNN-XGXHKTLJSA-N 0.000 description 1
- 125000005474 octanoate group Chemical group 0.000 description 1
- 150000002894 organic compounds Chemical class 0.000 description 1
- 230000003647 oxidation Effects 0.000 description 1
- 238000007254 oxidation reaction Methods 0.000 description 1
- TWNQGVIAIRXVLR-UHFFFAOYSA-N oxo(oxoalumanyloxy)alumane Chemical compound O=[Al]O[Al]=O TWNQGVIAIRXVLR-UHFFFAOYSA-N 0.000 description 1
- NDLPOXTZKUMGOV-UHFFFAOYSA-N oxo(oxoferriooxy)iron hydrate Chemical compound O.O=[Fe]O[Fe]=O NDLPOXTZKUMGOV-UHFFFAOYSA-N 0.000 description 1
- 229910052760 oxygen Inorganic materials 0.000 description 1
- 239000001301 oxygen Substances 0.000 description 1
- 239000003208 petroleum Substances 0.000 description 1
- 239000004033 plastic Substances 0.000 description 1
- 229920003023 plastic Polymers 0.000 description 1
- 229910052697 platinum Inorganic materials 0.000 description 1
- 239000002685 polymerization catalyst Substances 0.000 description 1
- 230000002028 premature Effects 0.000 description 1
- 239000010453 quartz Substances 0.000 description 1
- 230000003014 reinforcing effect Effects 0.000 description 1
- 150000003839 salts Chemical class 0.000 description 1
- 238000007086 side reaction Methods 0.000 description 1
- 229910000077 silane Inorganic materials 0.000 description 1
- 235000012239 silicon dioxide Nutrition 0.000 description 1
- 229920005573 silicon-containing polymer Polymers 0.000 description 1
- 238000000371 solid-state nuclear magnetic resonance spectroscopy Methods 0.000 description 1
- 241000894007 species Species 0.000 description 1
- 229910052566 spinel group Inorganic materials 0.000 description 1
- 229910052682 stishovite Inorganic materials 0.000 description 1
- 238000003860 storage Methods 0.000 description 1
- 229910052717 sulfur Inorganic materials 0.000 description 1
- 239000011593 sulfur Substances 0.000 description 1
- GJBRNHKUVLOCEB-UHFFFAOYSA-N tert-butyl benzenecarboperoxoate Chemical compound CC(C)(C)OOC(=O)C1=CC=CC=C1 GJBRNHKUVLOCEB-UHFFFAOYSA-N 0.000 description 1
- 238000010998 test method Methods 0.000 description 1
- VZGDMQKNWNREIO-UHFFFAOYSA-N tetrachloromethane Chemical compound ClC(Cl)(Cl)Cl VZGDMQKNWNREIO-UHFFFAOYSA-N 0.000 description 1
- 239000004408 titanium dioxide Substances 0.000 description 1
- 229910052905 tridymite Inorganic materials 0.000 description 1
- 238000004073 vulcanization Methods 0.000 description 1
- 238000009736 wetting Methods 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
- C08K5/00—Use of organic ingredients
- C08K5/04—Oxygen-containing compounds
- C08K5/14—Peroxides
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
- C08L83/00—Compositions of macromolecular compounds obtained by reactions forming in the main chain of the macromolecule a linkage containing silicon with or without sulfur, nitrogen, oxygen or carbon only; Compositions of derivatives of such polymers
- C08L83/04—Polysiloxanes
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
- C08G77/00—Macromolecular compounds obtained by reactions forming a linkage containing silicon with or without sulfur, nitrogen, oxygen or carbon in the main chain of the macromolecule
- C08G77/04—Polysiloxanes
- C08G77/20—Polysiloxanes containing silicon bound to unsaturated aliphatic groups
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
- C08G77/00—Macromolecular compounds obtained by reactions forming a linkage containing silicon with or without sulfur, nitrogen, oxygen or carbon in the main chain of the macromolecule
- C08G77/04—Polysiloxanes
- C08G77/22—Polysiloxanes containing silicon bound to organic groups containing atoms other than carbon, hydrogen and oxygen
- C08G77/24—Polysiloxanes containing silicon bound to organic groups containing atoms other than carbon, hydrogen and oxygen halogen-containing groups
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
- C08G77/00—Macromolecular compounds obtained by reactions forming a linkage containing silicon with or without sulfur, nitrogen, oxygen or carbon in the main chain of the macromolecule
- C08G77/70—Siloxanes defined by use of the MDTQ nomenclature
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
- C08G77/00—Macromolecular compounds obtained by reactions forming a linkage containing silicon with or without sulfur, nitrogen, oxygen or carbon in the main chain of the macromolecule
- C08G77/80—Siloxanes having aromatic substituents, e.g. phenyl side groups
Landscapes
- Chemical & Material Sciences (AREA)
- Health & Medical Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Medicinal Chemistry (AREA)
- Polymers & Plastics (AREA)
- Organic Chemistry (AREA)
- Compositions Of Macromolecular Compounds (AREA)
Abstract
Cold processable heat curable alkenyl silicone rubbers comprise an alkenyl silicone gum or mixture of alkenyl silicone gums selected from the group of alkenyl silicone gums having the formula: (MaM<vi>1-a)(D<vi>)x(D)x(D)y(MaM<vi>1-a) and having a viscosity of 200,000 to 200,000,000 centipoises a vinyl specific peroxide curing agent and a diluent gum, which is an MDM polysiloxane of viscosity 200,000 to 200,000,000 centipoises.
Description
1 IMPROVED HEAT CURED RUBBERS 60SI-01745BI 2335660 The present invention
relates to heat curable alkenyl silicone rubber formulations suitable for use as gaskets wherein low compression set and an improved sealing force retention are achieved by the use of high vinyl content gums and fumed silica fillers that have been treated 5 wherein the surface hydroxyl content is below a given threshold- value.
BackMund of the Invention Most heat-curing silicone rubbers are based on high molecular weight silicone polymer gums. Gums, fillers, and additives are mixed indough mixers or Banbury type mixers or raills to produce the heat curable formulation. Curing catalysts are added on water cooled rubber mills, to avoid premature heat cure, which can sometimes be used for the entire formulation in small-scale processes Silicone rubbers are commercially available as gums, fillerreinforced gums, dispersions, and uncatalyzed and ready-to-use catalyzed mixtures. The following types of gums are commercially available:
1).general purpose gums based on methyl and vinyl gums, 2) high and low temperature gums based on phenyl, vi nvI, and methyl gums, 3) low compression set gums based on methyl and vinyl gums, 4) low shrink gums, i.e. gums which have been devolatilized, and 5) solvent resistant gums, based on fluorosilicone gums.
The consistency of uncured rubber mixtures ranges from a tough putty to a hard deformable plastic. Those rubbers containing reinforcing fillers tend to stiffen on storage due to the development of structuse in the filler. Low viscosity fluids added to the rubber, such as water, 2 diphenylsilanediol-, or silicone fluids inhibit stiffening and the development of structure.
1 The properties of fabricated rubber depend not only on the chemical nature of the gum but also on the properties of the filler, additives, and " of curing catalyst Consequently, the resultant property profile of a given heat cured silicone rubber is highly dependent on the chemical nature of the various constituent components as well as the relative proportions of those components. For example, a high filler content increases hardness and solvent resistance of the resulting rubber.
Such increased hardness and solvent resistance however, comes at the price of a reduced elongation.
Not only do the properties of heat cured silicone rubber vary with the nature of the silicone gum and the various additives as wdU as their respective proportions but the properties also vary as a result of the various procedures used to compound the rubber. Properties of a heat cured rubber may therefore vary as a function of the thoroughness of the mixing and the degree of wetting of the filler by the gum. All other factors being equal, a hydrophilic filler as opposed to a hydrophobic filler will impart significantly different properties to a finished rubber.
Further, properties of heat cured rubbers change with time. This is particularly true during the initial periods of the curing reaction. Since silicone rubbers are complex chemical mixtures, the cure reactions and associated side reactions n ever completely stop although they may slow down considerably after the initial cure. The properties of a heat cured rubber change slowly with age.
Silicone rubbers may be cured by one of three general curing techniques:
1) hydrosilylation, 2) free radical initiation, and 3) high energy radiation initiation.
For a hydrosilylation cure, high molecular weight polymers, i.e. gums, possessing a vinyl functionality are reacted with low molecular weight hydride-functional cross-linking agents. A stable platinum complex, functioning as a catalyst is added along with an inhibitor to prevent cure initiation prior to heating.
3 Free radical- curing of silicone rubbers is effected by heating the rubber precursor in the presence of a free radical initiatorsuch as benzovl peroxide. The predominant mechanism operating involves hydrogen abstraction from the methyl groups of the dimethylsiloxane moiety followed by radical attack on another methyl group creating a cross linking ethylene bridge. If a small percentage of vinyl groups are present, the methyl radical can add to the vinylic double bond. In addition to benzovl peroxide, other radical cure initiators include bis(2,4 d ichloro benzoyl) peroxide, tert-butyl peroxybenzoate, dicurnyl peroxide, 2,5-dimethyl-di-(tert-butylperoxy)hexane, and 1,1-di-(tert-butylperoxy) trimethyleyclohexane. Both 2,5-dimethvl-di-(tert-butylperoxv)hexane, and 1,1-di-(tert-butylperoxy)-trimethylcyclohexane are particularly useful and specific as free radical cure initiators for vinyl silicone heat cured rubbers.
High energy radiation, either as gamma rays or as an electron beam, can also effect cures. This type of cure causes a wide variety of bonds to be broken, thus cross-links occur between a variety of different atomic centers as the radicals created by the high energy recombine to form new chemical bonds.
When a heat cured rubber formulation is used to manufacture products such as gaskets, the particular end use and the environment of that end use govern how the material is formulated and processed. In the case of gaskets, compression set, sealing force, and retention of sealing force are important measure s of performance. Compression set has.been a significant factor in heat cured rubber technology for many years.
U. 5. patent 2,803,619 discloses a polydimethylsiloxane gum filled with fumed silica and diatomaceous earth having a low compression set The heat cured rubber of the'619 patent was cured by a peroxide initiated vulcanization lasting five minutes at 150 OC followed by a twenty-four hour cure at 250 OC Subsequently after an additional twenty-two hours at 150 OC, the compression set of the finished rubber was measured.
Curing of a heat cured rubber begins when the cure is initiated during the molding process. The cure must be sufficiently rapid that the article can be removed from the mold without deformation. Yet the requirement that the finished product possess elastomeric properties in 4 some degree mean's that the cure cannot proceed to the extent that the initially elastomeric heat cured rubber is no long& deformable. Thus the kinetics of the cure reaction must be carefully balanced for a, rapid initial cure.
Subsequent developments have focused on three technical issues:
1) in-situ filler treatment, 2) post-reaction catalyst inhibition, and 3) additives.
In-situ filler treatment mav be divided into two broad classes: 1) vinyl silazane treatment of the filler, and 2) vinyl alkoxy silane treatments.
In the case of free-radical cures, generally peroxide initiated, the initiator is consumed. Use of gamma radiation or high energy electron beams also leaves -no reactive residues in the rubber. -When a hydrosilylation catalyst is used to effect a cure in a vinyl-hvdride compound rubber, the cure must be controlled because the catalyst is not destroyed by the cure reaction. Thus a large variety of inhibitor compounds have been used: alkaline earth metal silicates (U. 5. patent 3,817,910), metal sulfides (U. S. patent 5,219,922), boron compounds (U. 5.
patent 4,690,967), and various organic compounds (U. S. patent 5,153,244).
Additives to heat cured rubbers to control compression set most frequently involve the addition of substituted silicone resim Recently, in sharp contrast, spinels have been used to control compression set (U. S.
patent 5,260,364). Since the silicone resins added to the heat cured rubber formulation for compression set control are highly branched silicone resins, depending on when these resins are added can sometimes lead to the conclusion that these materials form part of the elastomeric matrix of the heat cured rubber.
A current problem not yet solved by the art deals with the incompletely reacted surface silanol groups of the various silica fillers currently in use. The presence of reactive, i.e. unreacted, surface hydroxyl or silanol groups in a silica filler leads to condensation reactions and structuring of the filler. One solution currently in use is to use silanot or methoxy stopped silicone fluids as blending agents to assist in dispersing the filler into the gum and also provide a reaction center that does not lead to structuring of the filler. In a sense, these blending agents are reactive diluents as they react with the filler surface hydroxyl or silanol groups preventing the condensation reactions between filler particles or filler and gum molecules that lead to stiffening and a loss of elastomeric properties.
S=mAly of the- Invention The present invention provides for a class of cold processable heat curable alkenyl silicone rubbers that comprise:
(1) an alkenyl silicone gum or mixture of alkenyl silicone gums selected from the group of alkenyl silicone gums having the formula:
(MaMY'I-a)(Dvl)x(D)y(MaM"1-a) where a is zero or one and x and y are zero or integers whereby the sum of x+v Yields a gum having a viscosity ranging from about 200,000 to about 200,000,000 centipoise at 25 OC and whereby the sum -of a+x+v yields a gum having an alkenyl content ranging from.' 0.20 to 14.00 weight percent subject to the limitation that x must be greater than zero when a is one, where M = R135i01/2 with RI - selected from the group consisting of 1 to 8 carbona'tom alkyl groups, phenyl, and trifluoropropyl; Mvi = R2(R1)25i01/2 with R1 selected from the group consisting of 1 to 8 carbon atom alkyl groups, phenyl, and trifluoropropyl and R2 selected from the group of 2 to 10 carbon atom linear or cyclic alkenyl groups; Dvi = R2(R1)5i02/2 where R1 and R2 are as previously defined; D = (R3)2SiO2/2 where each R3 is independently selected from the group consisting of 1 to 8 carbon atom alkyl groups, phenyl, and trifluoropropyl; and (2) a vinyl specific peroxide curing agent When a mixture of gums is used, a preferred mixture comprises at least three gums defined by the formulas: (1) MvirDviDMvI; (2) MviDMvis; and (3)MDviM, The gums of the present invention are amenable to incorporating various additives, fillers, extenders and diluents. - For example when a 6 diluent gum is usd in conjunction with the alkenyl silicones of the present invention, a gum having the formula:
MDM, and having a viscosity ranging from 200,000 to 200,000,000 centipoise at OC is particularly preferred. - A particularly useful specific embodiment of the present invention comprises:
(a) from -, 5 parts by weight to 100 parts by weight of a vinyl on chain vinyl stopped gum having the formula:
MvI DvIxDY MVI where x and y are different integers greater than zero and the sum -of x and y have values whereby the viscosity of (a) is between 200,000 and 200,000,000 cps and the alkenyl level varies from percent to 14.00 weight percent, (b) from 0.2 parts by weight to.
vinyl stopped gum having the following formula:
W1 DZ W1 where z is an integer greater than zero having a value whereby the viscosity of (b) is between 200,000 and 200,000,000 cps and the alkertyl level varies from about 150 to - ' ---. 350 weight parts per miWon; (c) from 0.2 parts by weight to - ' 75 parts by weight of a vinyl on chain gum having non-reactive end groups with the following formula:
M DvIqM 0.20 weight parts by weight of a where q is an integer greater than zero whereby the viscosity of (c) is between 200,000 and 200,000,000 cps and the alkenyl level varies from 14.00 weight percent; 0.10 weight per cent to.
(d) from '.-: 0.0001 parts by weight to 30 parts by weight of a diluent gum having the following formula:
MDwM where w is an integer greater than zero whereby the viscosity of (d) is between 200,000 and 200,000,000 cps; whereby the quantities present of the components (a), (b), (c), and (d) add to 100 parts by weight; 7 (e) fro m 0.1 parts by weight to 1 5 parts by weight of an MQ resin, as a mold release agent, having a viscosity between 500 and 50,000 centipoise, where the M:Q ratio between 0.8A.0 and 0.8A.5; whereby the quantities present of the components (a), (b), (c), (d), and (e) add to between.. 100.1 parts by weight to - - '. 105 parts by weight; (f) from 15 to 80 parts by weight of a fumed silica filler functioning as a reinforcing filler, having a BET surface area in the range of 90 - 400 m2/gm where the residual level of surface hydroxyl groups determined by nitrogenous base chernisorption and magic angle spinning solid state nmr is below a threshold value of 3.1 hydroxyl groups / nm2.
whereby the quantities present of the components (a), (b), (c), (d), (e) and (f) add to between 115.1 parts by weight and 185 parts by weight; 1 is (g) from -, 0.01 to 1.5 parts by weight of a vinyl specific peroxide curing agent; whereby the quantities present of the components (a), (b), (c), (d), (e), (0 and (g) add to between 115.11 parts by weight and 186.5 parts by weight where:
M = R135i01/2 with RI selected from the group consisting'of 1 to 8 carbon atom alkyl groups, phenyl, and trifluoropropyl; Mvi = R2(R1)2Si01/2 with R1 selected from the group consisting of 1 to 8 carbon atom alkyl groups, phenyl, and trifluoropropyl and R2 selected from the group of 2 to 10 carbon atom linear or cyclic alkenyl groups; Dvi = R2(R1)5i02/2 where RI and R2 are as previously defined; D = (R3)2SiO2/2 where each R3 is independently selected from the group consisting of 1 to 8 carbon atom alkyl groups, phenyl, and trifluoropropyl; and Q = SiO4/2.
The curable rubbers of the present invention may be made by a cold mixing process comprising the steps of' (a) mixing a curable component selected from the group of alkenyl silicone gums having the formula:
8 (MaN"1-a)(Dll)x(D)Y('Ma'M-vll-a) with a vinyl specific peroxide curing agent., and (b) controlling the temperature of the mixing whereby the temperature of the mixture does not exceed 80 OC during the process of 5 mixing.
Further, the heat cured rubbers and articles of manufacture made from the composition of the present invention exhibit improved Compression set and have markedly improved heat age properties.
Detailed Description of the Invention
The present invention provides for a class of cold processable heat curable alkenyl silicone rubbers that comprise:
(1) an alkenyl silicone gum or mixture of alkenyl silicone gums selected from the group of alkenyl silicone gums having the formula:
(MaM'I-a)(Dvl)x(D)V(MaMv'l-a) where a is zero or one and x and y are zero or in"ers whereby the sum of x+v yields a gum having a viscosity ranging from 200,000 to.
-- 200,000,000 centipoise at 25 OC and whereby the sum of a+x+v yields a gum having an alkenyl content ranging from 0.20 to 14.00 weight percent subject to the limitation that x must be greater than zero when a is one, where M = R13Si01/2 with R1 selected from the group consisting of 1 to 8 carbon atom alkyl groups, phenyl, and trifluoropropyl; Nfvi = R2(R1)25i01/2 with RI selected from the group consisting of 1 to 8 carbon atom alkyl groups, phenyl, and trifluoropropyl and R2 selected from the group of 2 to 10 carbon atom linear or cyclic alkenyl groups; Dvi = R2m lxl)SiO2/2 where RI and R2 are as previously defined; D = (R3)2SiO2/2 where each R3 is independently selected from the group consisting of 1 to 8 carbon atom alkyl groups, phenyl, and trifluoropropyl; and (2) a vinyl specific peroxide curing agent When a mixture of gums is used, a preferred mixture comprises at least duee gums defined by the formulas:
(1) MmDvIDMvI; (2) NIVIDWI; and 9 (3)MWIM.- The gums of the present invention are amenable to incorporating various additives, fillers, extenders and diluents. For example when a diluent gum is used in conjunction with the alkenyl silicones of the 5 present invention, a gum having the formula:
MDM, and having a viscosity ranging from 200,000 to 200,000,000 centipoise at 25 OC is particularly preferred.
A particularly useful specific embodiment of the present invention comprises:
(a) from 5 parts by weight to 100 parts by weight of a vinyl on chain vinyl stopped gum having the formula:
MV1 W1xDV Mvi where x and v are different integers greater than zero and the sum of x and y have values whereby the viscosity of (a) is between 200,000 and 200,000,000 cps and the alkenyl level varies from 0.20 weight percent to 14.00 weight percent; (b) from - - 0.2 partsby weight to 95 parts by weight of a vinyl stopped gum having the following formula:
M-vi Dz Mvi where z is an integer greater than zero having a value whereby the viscosity of (b) is between 200,000 and 200,000,000 cps and the alkenyl level varies from--- 150 to - - 350 weight parts per million; (c) from 0.2 parts by weight to about 75 parts by weight of a vinyl on chain gum having non-reactive end groups with the following formula:
M DviqM where q is an integer greater than zero whereby the viscosity of (c) is between 200,000 and 200,000,000 cps and the alkenyl level varies from -1 - 0.10 weight per cent to - 14.00 weight percent; (d) from 0.0001 parts by weight to of a diluent gum having the following formula:
N4DwM parts by weight where w is an integer greater than zero whereby the viscosity of (d) is between 200,000 and 200,000,000 cps; whereby th quantities present of the components (a), (b), (c), and (d) add to 100 parts by weight, (e) from 0.1 parts by weight to 5 parts by weight of an MQ resin, as a mold release agent, having a viscosity between 500 and 50,000 centipoise, where the M:Q ratio between 0.8A.0 and 0.81.5; whereby the quantities present of the components (a), (b), (c), (d), and (e) add to between. 100.1 parts by weight to weight, (f) from 15 to parts by parts by weight of a fumed silica filler functioning as a reinforcing filler, having a BET surface area in the range of 90 - 400 m2/gm where the residual level of surface hydroxyl groups determined by nitrogenous base chemisorption and magic angle spinning solid state rumr is below a threshold value of 3.1 hydroxyl groups / nm2; whereby the quantities present of the components (a), (b), (c), (d), (e) and (f) add to between 115.1 parts by weight and 185 parts by weight, (g) from - - - 0.01 to 1.5 parts by weight of a vinyl specific peroxide curing agent; whereby the quantities present of the components (a), (b), (c), (d), (e), (f) and (g) add to between 115.11 parts by weight and 186.5 parts by weight; where:
M = R13Si01/2 with R1 selected from the group consisting of 1 to 8 carbon atom alkyl groups, phenyl, and trifluoropropyl; Mvi'= R2(R1)25i01/2 with RI selected from the group consisting of 1 to 8 carbon atom alkyl groups, phenyl, and trifluoropropyl and R2 selected from the group of 2 to 10 carbon atom linear or cyclic alkenyl groups; Dvi = R2(R1)Si02/2 where RI and R2 are as previously defined; D = (R3)2SiO2/2 where each R3 is independently selected from the 30 group consisting of 1 to 8 carbon atom alkyl groups, phenyl, and trifluoropropyl; and Q = Si04/. The curable rubbers of the present invention may be made by a cold mixing process comprising the steps of 11 (a) mixing a curable component selected from the group of alkenyl silicone gums having the formula:
(MaMv'l-a)(Dvi)x(D)V(MaMv'l-a) with a vinyl specific peroxide curing agent, and (b) controlling the temperature of the mixing whereby the temperature of the mixture does not exceed 100 OC, preferably 90 oc, more preferably 80 OC and most preferably 65 OC during the process of mixing.
Further, the heat cured rubbers and articles of manufacture made from the composition of the present invention exhibit improved compression set and have markedly improved heat age properties. The heat cured rubbers made with the composition of the present invention are useful for gaskets, bushings, o-rings, tubin& medical tubin& gas masks, catheters, windshield wiper blades, spatula blades, automobile radiator hoses, spark plug boots, keyboard keypads, baby bottle nipples, electrical connectors, grommets, seals, diving masks, snorkels, earplugs, mouthguards, and foamed heat cured rubber products.
One very specific embodiment of the present invention relates to a heat curable silicone rubber composition that is cold processable consisting essentially of a mixture of the following components:
(a) a vinyl on chain vinyl stopped gum having the formula:
Mvi DvixID, Nfvi where x and y are different integers greater than zero and the sum of x and v have values whereby the viscosity of (a) is between 200,000 and 200,000,000 cps and the alkenyl level varies from 0.20 weight percent to - 14.00 weight percent; (b) a vinyl stopped gum having the following formula:
W1 DZ MY' where z is an integer greater than zero having a value whereby the viscosity of (b) is between 200,000 and 200,000,000 cps and the alkenyl level varies from - ' 150 to - 350 weight parts per milli on; (c) a vinvLon chain gum having non-reactive end groups with the following formula:
N4 DviclM 12 where q is an intdger greater than zero whereby the viscosity of (c) is between 200,000 and 200,000,000 cps and the alkenyl level varies from 0.10 weight per cent to 14.00 weight percent; (d) an optional diluent gum having the following formula:
MDwM where w is an integer greater than zero wherebv the viscosity of (d) is between 200,000 and 200,000,000 Cps; (e) an MQ resin, as a mold release agent, having a viscosity between 500 and 50,000 centipoise, where the ratio M: Q varies between 0.8A.0 and -. 0.8: 1.8; (f) a fumed silica filler functioning as a reinforcing filler, having a BET surface area in the range of 90 - 400 m2/gm where the residual level of surface hydroxyl groups determined by nitrogenous base chemisorption or magic angle spinning solid state n-mr is- below a threshold value of 3. 1 hydroxyl groups / nm2.. and (g) any of several vinyl specific peroxide curing agents. The formulation may also contain extending. fillers and other additivesdesigned to impart specific performance properties.
In the components of the present invention, applicants define the following structures:
M = R135i01/2 where R1 is selected from the group consisting of 1 to 8 carbon atom alkyl groups, phenyl, and trifluoropropyl; Mvi = R2(R1)25iCh/2 where RI is selected from the group consisting of 1 to 8 carbon atom alkyl groups, phenyl, and trifluoropropyl and R2 is selected from the group of 2 to 10 carbon atom linear or cyclic alkenyl groups; Dvix = R2(R1)5i02/2 where the R groups are a s pr. eviously defined; D = (R3)25i02/2 where each R3 group is independently selected from the group consisting of 1 to 8 carbon atom alkyl groups, phenyl, and trifluoropropyl; and Q = 5i04/2. All of the gum components utilized by the present invention have a viscosity ranging from 200,000 to 200,000,000 centipoise at 25 OC- 13 The amoudts of the above components may be varied in a wide ranging fashion to produce rubbers of the prese n't invention. Each of the components of the present invention are present in amounts as follows:
Component Lower Limit Upper Limit parts by weight parts by weight (a) 5 100 (b) 0.2 95 (c) 0.2 75 (d) 0.0001 30 (e) (0 is 80 (g) 0.01 1.5 Extending fillers 0 80 Other Additives 0 10 The first four components (a) + (b) + (c) + (d) must sum to 100 parts by weight and the total alkenyl level of the. mixture of the four component gums (a), (b), (c) and (d) ranges between 0.20 weight percent and 14.00 weight percent.
Applicants note that it is a standard chemical shorthand in the field of silicone chemistry to refer to various fluids, resins and gums by such general designations as MIDM for an M-stopped polydiorganosiloxane where the degree of polymerization of the repeating D units is unspecified except as to viscosity of the resulting polymer. Thus more particularly, M1DXM, where x is a stoichiometric coefficient indicating a degree of polymerization would vary and low values of x. produce pourable fluids, intermediate values of x produce more viscous fluids, and high values produce gums and that as x increases so does viscosity. Thus in terms of notation and equivalence, MIDviDM is exemplary of a chemical shorthand where the structure of the polymer more properly possesses stoichiometric subscripts, Le. MIDYIxIDY M, and these relate directly to degree of polymerization and vt,,cosity. By stipulating a viscosity for a given polymeric silicone, these stoichiometric subscripts are defined, even if their presence must be inferred from the chemical shorthand used.
0.1 14 The vinyl specific peroxide curing agent (9) may be any one of several known in the art as taught in U. 5. patent 4,539.357 at column 9 lines 1 et seq. Applicants specifically prefer the use of 2,5-dimethyl-ter-tbutvl- peroxy-hexane; 2,4-d ic hi o ro-benzov 1 peroxide, di-curnyl-peroxide, and 1,1-di(tert-butvlperoxvtrimethvl)cyclohexane or mixtures thereof.
The formulation of the present invention is unique insofar as the elimination of process aids is now possible. Heretofore it has been necessary to add some small quantity of very low viscosity silanol or methoxy stopped fluids to prevent structuring of the filler when the mixture of gums and fumed silica filler is mixed together to form the precursor mixture to the composite and also to lower the viscosity of the very high viscosity gums used to make the precursor mixture since the lower viscosity aids in processing the mixture in milling equipment U. S. patent 4, 539,357 discusses the necessary use of process aids in the manufacture of heat cured rubbers from gums at column 10 line 53 et seq. The addition of such process aids has several serious drawbacks in the art of heat curable rubber compositions. At temperatures below about 150 oc the presence of a very low viscosity silicone fluid decreases heat stability and compression set of the final product rubber. At temperatures above about 150 OC, the process aids tend to act as de-polymerization catalysts.
Another other unique aspect of the present invention regards the surface properties of the fumed silica filler used as a reinforcing filler in the heat curable compositions of the present invention. Various forms of untreated and treated pyrogenic or fumed silica fillers have been employed. Frequently the treatments of choice involve treating with low molecular weight cyclic oligomeric silicones such as octamethyleydotetrasiloxane or silazane species such as hexamethyldisilazane. The art of such treated fillers has even involved double treating of such materials, first with a silazane followed by a finishing treatment with a low molecular weight cyclic oligomer. Usually these treatments are conducted in situ and on an ad hoc basis. Frequently, the techniques have been such that process aids are selected for their ability to fulfill a dual function, that is to reduce the viscosity of the gum blend and treat the surface of the fumed silica reinforcing filler, simultaneously. Applicants have discovered that it is immaterial whether the pyrogenic or fumed silica is treated once or twice, in situ or ex situ, and the critical properties of the treated filler are not so much an extensive property such as surface area but an intensive property, the surface density of unreacted hydroxyl terminations.
Ln amorphous materials high surface area materials such as silicas, aluminas, and silica-alurnina co-gels, the high frequency of crystallographic stacking faults, Schottkey and Frenkel defects that give rie to very low crystallite size and thus high surface area, lead to deficiencies in satisfying the oxidation state of the primary cations involved in the structure. Whether the structure is inorganic and thus relies on the presence of oxygen or sulfur for the anions or organic as in the case of activated carbon, the valence deficiencies that occur as a consequence of the phase boundary where the structure te=inates are satisfied by hydrogen. With oxides this leads to surface hydroxyl groups.
In the case of silicas, these surface hydroxyl or silanol groups readily inter-condense forming Si-O-Si bonds between adjacent particles that lead to structuring of the silica particles. Irrespective of how this intensive property is controlled, when the surface hydroxyl or silanol density of a fumed silica is below a threshold value of roughly 3.1 hydroxyls / nm2,structuring either does not occur or is minimized to a point where it does not appreciably interfere with processing of the gum filler mixture. Prior art treatments may have accomplished this control to a greater or lesser degree, however it is not the treatment per se that is important but reducing the surface concentration of hvdroxyl or silanol groups on the silica surface that is critical.
The elimination of process aids and the control of surface intensive properties of the silica filler leads to significant advantages. Mixtures of these particular gums are cold processable and the resulting heat curable rubbers apparently do not require the presence of additives thatstabilize the cured rubber to the effects of petroleum derived oils.
The essential components of the heat curable rubbers of the present invention are the vinyl silicone gums which may be any of (a), (b), or (c); the mold release agent, the vinyl specific peroxide curing agent, and the reinforcing fumed or pyrogenic silica filler. To this mixture, mav be added extending fillers such as precipitated silica, finely divided quartz, I 1 16 % mica, alumina and titania. AdditionallY, additive materials which impart specific- performance features the, finished cured rubber composition may also be incorporated such as zinc oxide, magnesium oxide, copper oxide, ferrous oxide, ferric oxide, aluminum oxide, titanium dioxide, ceric oxide, ceric hydroxide, and the various metal salts of long chain fatty acids such as the metal octoates.
The cold processable or mixable heat curable rubbers of the present invention have improved compression set, improved oil resistance, and improved compression stress relaxation, i.e. sealing force retention. By cold processable or mixable Applicants define a mixing process conducted below about 100 OC The following examples are illustrative of the invention and serve as demonstrative examples only. BY being set forth as examples of the invention, the following examples are not intended to limit the scope of the invention as conceived by the Applicants. All U. S. patent referenced herein are herewith specifically included by reference.
Enerimental 2-5 ExamRle 1:
An organopolvsitoxane composition containing 0.2 male % alken.vl as vinyl was prepared by blending in a non-heated mixer such as a Banbury mixer, a mixture composed of 67 parts by weight of a vinyl stopped polydimethysitoxane gum having a vinyl content of 225 wppm vinyl and a viscosity of 77.55,000 poise, 33 parts by weight of. methyl stopped dimethysiloxane, vinvlrnethylsiloxane copolymer gum having a vinyl content of 0-2 weight percent and a viscosity of 400,000 poise, 0.5 parts by weight of an MQ siloxane resin, 40 parts by weight of a fumed silica having a surface hydroxyl concentration below 3.1 hydroxyls or silanols per square nano-meter (nrn)wherein the surface hydroxyl concentiration was reduced to below this level by treatment with octamethylcyclo tetras iloxane followed by treatment with hexamethyldisilazane having a surface area of 200 m2/g; 20 parts by weight of 5 [im Minusil @, 1.0 parts by weight zinc oxide, 0.25 parts by weight magnesium oxide, 0.45 parts by weight cerium hydroxide, and 0.12 parts by weight black iron oxide (ferrous oxide). This composition was thoroughly mixed while keeping the temperature below about 65 C)C- 17 Following the addition of the foregoing components, 0.65 parts by weight of 2,5-dimethyl-di(tertiary-butvl-peroxy) hexane was added as a free radical cure catalyst and after two minutes of mixing the batch was discharged, extruded through a 150 mesh screen, press cured at 177 OC for 17 minutes and tested for physical properties. The physical properties are summarized in Table 1.
Example I-
An organopolysiloxane composition containing 0.2 mole % alkenyl as vinyl was prepared and cured as described in Example 1 except that the gum was a vinyl stopped dimethylsiloxane vinylmethyisiloxane copolymer gum having 800 wppm vinyl and a viscosity of 225,000 poise.
The physical properties of this composition are listed in Table 1.
Example 3:
An organopolysiloxane composition contairdng 0.4 mole % alkenyl as vinyl was prepared by blending in a non-heated mixer, i.e. a Banbury mixer, a mixture composed of 90 parts by weight of a vinyl stopped polydimethylsiloxane gum having a vinyl content of 225 wppm vinyl, and a viscosity of 225,000 pois'p-, 10 parts by weight of a vinyl stopped dimethylsiloxane vinylmethylsiloxane copolymer gum having 4.o weight per cent vinyl and a viscosity of 580,000 poise, 0.5 parts by weight of an MQ siloxane resin, 35 parts by weight of a fumed silica as in Example 1; 15 parts by weight of 5 gm Minusil @, 1.0 part by weight of zinc oxide, 0.25 parts by weight of magnesium oxide, 0.45 parts by weight of cerium hydroxide, and 0.12 parts by weight of black iron oxide. The formulation was thoroughly mixed while keeping the temperature under 65 OC.
Following the addition of the foregoing components, 0.61 parts by weight of 2,5-dimethyl-di-(tertiary-butvl-peroxy) hexane was added as a free radical cure catalyst and after two minutes of mixing the batch was discharged, extruded through a 150 mesh screen, press cured at 177 OC for 17 minutes and tested for physical properties. The physical properties are summarized in Table 1.
ExampIc 4:
An organopolysiloxane composition containing 0.4 mole % alkenyl as vinyl was prepared by blending in a non-heated mixer, i.e. a Banbury mixer, a mixture composed of 80 parts by weight of a vinyl stopped 18 polydimethylsiloxane gum having a vinyl content of 225 wppm vinyl, and a viscosity of 225,000 poise, 10 parts by weight of vinyl stopped dimethylsiloxane vinvimethylsiloxane copolymer gum having a vinyl content of 4.0 weight per cent and viscosity of 580,000 poise, 10 parts by weight of a methyl stopped polydirnethvisiloxane gum having a viscosity of 225, 000 poise, 0.5 parts by weight of an MQ resin, 40 parts by weight of a fumed silica as in Example 1, 20 parts by weight of 5 pirn Minusil 0, 1.0 parts by weight zinc oxide, 0.25 parts by weight magnesium oxide,, 0.45 parts by weight of cerium hydroxide, and 0.12 parts by weight of black iron oxide. The formulation was thoroughly mixed while keeping the temperature under 65 OC. Following the addition of the foregoing components, 0.65 parts by weight of 2,5-dimethyl-di-(tertiarybutvlperoxy) hexane was added as a free radical cure catalyst and after two minutes of mixing the batch was discharged, extruded through a 150 mesh screen, press cured at 177 OC for 17 minutes and tested for physical properties. The physical properties are summarized in Table 1.
Example 5:
An organopolysiloxanecomposition containing 0.6 mole % alkenyl as vinyl was prepared by blending in a non-heated mixer, i.e. a Banbury mixer, a mixture composed of 80 parts by weight of a vinyl; stopped polydimethylsiloxane gum having 225 wppm vinyl and a viscosity of 225,000 poise, 20 parts by weight of a vinyl stopped dimethylsiloxane vinvlmethylsiloxane copolymer gum having 4.0 weight per cent vinyl and a viscosity of 580,000 poise, 0.5 parts by weight of an MQ siloxane resin, parts by weight of a fumed silica as in Example 1, 10 parts by weight of 5 pirn tyfinusil ID, 1.0 parts by weight of zinc oxide, 0.25 parts by weight magnesium oxide, 0.45 Parts by weight of cerium hydroxide, and 0.12 parts by weight of black iron oxide. The formulation was thoroughly mixed while keeping the temperature under 65 OC. Following the addition of the foregoing components, 0.57 parts by weight of 25 dimethyl-di-(tertiary-butyl-peroxy) hexane was added as a free radical cure catalyst and, after two minutes of mixing the batch was discharged, extruded through a 150 mesh screen, press cured at 177 OC for 17 minutes and tested for physical properties. The physical properties are summarized in Table 1.
1 19 Example 6:
An organopolysiloxane composition containing 0.8 mole % alkenyl as vinyl was prepared by blending in a non-heated mixer, i.e. a Banbury mixer, a mixture composed of 75 parts by weight of a vinyl stopped dimethylsiloxane vinyimethyisiloxane copolymer gum having 800 wppm vinyl and a viscosity of 225,000, 15 parts by weight of a vinyl stopped dimethylsiloxane vinylmethyisilaxane copolymer gum having a vinyl content of 4.0 weight percent and a viscosity of 580,000 poise, 15 parts by weight a methyl stopped polydimethyisiloxane gum having a viscosity of 225,000 poise, 35 parts by weight of a fumed silica as in Example 1, 15 parts by weight of 5 pim Minusit @, 1.0 parts by weight of zinc oxide, 0. 25 parts by weight magnesium oxide, 0.45 parts by weight of cerium hydroxide, and 0.12 parts by weight of black iron oxide. The formulation was thorougWY mixed while keeping the temperature under 65 OC.
Following the addition of the foregoing components, 0.61 parts by weight of 2,5-dimethvl-di-(tertiary-butvl-peroxy) hexane was added as a free radical cure catalyst and after two minutes of mixing the batch was discharged, extruded through a 150 mesh screen, press cured at 177 OC for 17 minutes and tested for physical properties. The physical properties are summarized in Table 1.
ExamRle 7 An organopolysiloxane composition containing 0.6 mole % alkenyl as vinyl was prepared by blending in a non-heated mixer, i.e. a Banbury mixer, a mixture composed of 80 parts by weight of a vinyl stopped polydimethylsiloxane gum having a vinyl content o f 225 wppm vinyl and a viscosity of 225,000 poise, 20 parts by weight of a vinyl stopped dimethylsiloxane vinyimethyisiloxane copolymer gum having a vinyl content of 4.0 weight per cent and a viscosity of 580,000 poise, 0.5 parts by weight of an MQ siloxane resin, 35 parts by weight of a fumed silica as in Example 1, 19 parts by weight of 5 4m Minusil 8, 1.0 parts by weight of zinc oxide, 0.25 parts by weight magnesium oxide, 0.45 parts by weight of cerium hydroxide, and 0.12 parts by weight of black iron oxide. The formulation was thoroughly mixed while keeping the temperature under OC Following the addition of the foregoing components, 0.57 parts by weight of 2,5-dimethvl-di-(tertiarv-butvl-peroxv) hexane was added as a free radical cure catalyst and after two minutes of mixing the batch was discharged, extruded through a 150 mesh screen, press cured at 177 OC for 17 minutes and tested for physical properties. The physical properties are summarized in Table 1.
1 1 ExamRle 8:
An organopolysiloxane composition containing 0.5 mole % alkenvI as vinyl was prepared by blending in a non-heated mixer, i.e. a Banbury mixer, a mixture composed of 75 parts by weight of a vinyl stopped polydimethylsiloxane gum having a vinyl content of 225 wppm and a' viscosity of 225,000 poise, 15 parts by weight of a vinyl stopped dimethylsiloxane vinyl methylsiloxane copolymer gum having a vinyl content of 4.0 weight percent and a viscosity of 580,000 poise, 10 parts by weight of a methyl stopped polydirnethylsiloxane gum having a viscosity of 225,000 poise, 0.5 parts by of an MQ siloxane resin, 45 parts by weight of a fumed silica as in Example 1, 25 parts by weight of 5 gm Minusil 0, 1.0 parts by weight of zinc oxide. 0.25 parts by weight magnesium oxide,.
0.45 parts by weight of cerium hydroxide, and 0.12 parts by weight of black iron oxide. The formulation was thoroughly mixed while keeping the temperature under 65 OC. Following the addition of the foregoing components, 0.65 parts by weight of 2,5-dimethyl-di-(tertiary-butvlperoxy) hexane was added as a free radical cure catalyst and after two minutes of mixing the batch was discharged, extruded through a 150 mesh screen, press cured at 177 OC for 17 minutes and tested for physical properties. The physical properties are summarized in Table 1.
Example 9:
An organopolysiloxane composition containing 0.6 mole % aLkenyl as vinyl was prepared by blending in a non-heated mixer, i.e. a Banbury mixer, a mixture composed of 70 parts by weight of a vinyl stopped polydimethylsiloxane gum having a vinyl content of 225 wppm and a viscosity of 225,000 poise, 20 parts by weight of a vinyl stopped vinyl stopped dimethylsiloxane vinvimethylsiloxane copolymer gum having a vinyl content of 4.0 weight per cent and a viscosity of 580,000 poise, 10 parts by weight of a methyl stopped polvdimethyisiloxane gum having a viscosity of 225,000 poise, 0.5 parts by weight of an MQ siloxane resin, 39 parts by weight of a fumed silica as in Example 1, 15 parts by weight of 5 21 im Minusil 8, 1.0 parts by weight of zinc oxide, 0.25 parts by weight magnesium oxide, 0.45) parts by weight of cerium hydroxide, and 0.12 parts by weight of black iron oxide. The formulation was thoroughly mixed while keeping the temperature under 65 OC. Following the 5 addition of the foregoing components, 0.65 parts by weight of 25dimethvl-di-(tertiarybutvi-peroxy) hexane was added as a free radical cure catalyst and after two minutes of mixing the batch was discharged, extruded through a 150 mesh screen, press cured at 177 OC for 17 minutes and tested for physical properties. The physical properties are summarized in Table 1. Example 10: Compression Stress relaxation (CSR) Test Method An "0" ring test piece having an inner diameter of 12-7 mm and an outer diameter of 19.0 mm is cut from an ASTM slab of a press cured composition. The thickness of the "0" ring is measured at four places on the rin& with each measurement offset by a radial angle 900 relative to the previous measurement The "0" ring is placed between parallel plates of a Shawbury-Wa 1 lace test device or jig that has been freshly cleaned and lightly oiled with IRM-903 'Oil as test fluid. The sample is thencompressed 25% based on the initial average of the 4 four thicknessmeasurements and after about 30 minutes of compression at ambient- temperature, an initial, counter force was determined by measuring the counter force on a Shawbury-Wa 1 lace compression stress relaxometer and subtracting the jig break force. The jig is then immersed in IRM-903 oil at 150+2 OC to a depth covering the top parallel plate of the jig. At 168 hour intervals the jig is removed from the oil bath and the counter force measured after 4 hours at ambient temperature. The percent sealing force retention is then calculated by dividing the interval counter force by the initial counter force and multiplying by 100.
1- 22 Table 1: Physical Properties of Alkenyl Gum Heat Curable Rubbers Exa.mple 1 2 3 4 5 6 7 8 9 Property Shore A Tensile (psi) 1059 980 1033 1112 993 800 1002 1084 1084 Elongation W - 101 100% Modulus (psi) 135 121 178 198 315 Compression Set 22 Hours at 177 OC 9.7 8.4 10.0 12-2 6.3 7.8 C5R, % Sealing Force Retention 46 47 50 50 53 59 59 59 560 524 584 642 318 298 274 444 330 251 439 405 425 12-3 13.610.7 168 hrs 43 41 38 41 55 47 49 44 41 1000 hrs 23 25 33 34 30 27 27 2000 hrs 19 26 18 17 18 Notes: One week data only Data at 1000 hours Example 11:
In order to show the effect of different fillers on compression set an organopolysiloxane composition containing 0.6 mole 5 alkenyl as vinyl was prepared by blending in a non-heated mixer, i.e. a Banburymixer, a mixture composed of 80 parts by weight of a vinyl stopped polydimethylsiloxane gum having a vinyl content of 225 wppm vinyl and a viscosity of 225,000 poise, 20 parts by weight of a vinyl stopped dimethylsiloxane vinyImethylsiloxane copolymer gum having a weight percent vinyl content of 4.0 weight percent vinyl and viscosity of 580, 000 poise, 0.5 parts by. weight of an MQ siloxane resin, 30 parts by weight of an octamethylcyclotetrasiloxane treated fumed silica having a surface area of 200 m2/g and a surface hydroxyl content in excess of 2-75 x 109 hydroxyls / m2/ 10 parts by weight of 5 gm Minusil @, 1.0 parts by 1 23 weight of zinc oxide, 0.25 parts by weight magnesium oxide, 0.45 parts by weight of cerium hydroxide, and 0.12 parts by weight of black iron oxide.
The formulation was thoroughly mixed while keeping the temperature under 65 OC. Following the addition of the foregoing components, 0.60 parts by weight of 2,5-dimethyl-di-(tertiary-butyl-peroxy) hexane was added as a free radical cure catalyst and after two minutes of mixing the batch was discharged, extruded through a 150 mesh screen, press.cured at 177 OC for 17 minutes and tested for physical properties. The physical properties are summarized in Table 2.
Example 12_.
In order to demonstrate the effect of silanol process aids on compression, an organopolysiloxane composition containing 0.6 mole % alkenyl as vinyl was prepared by blending in a non-heated atixer, i.e. a Banbury, 80 parts by weight of a vinyl stopped polydimethylsiloxane gum having a vinyl content of 225 wppm vinyl and a viscosity of 225,000 poise, 20 parts by weight of a vinyl stopped dimethylsiloxane vinylmethyisiloxane copolymer gum having a vinyl content of 4.0 weight per cent vinyl and a viscosity of 580,000 poise, 0.5 parts by weight of an MQ siloxane resin, and 30 parts by weight of a fumed silica as in Example 1, 2-0 parts by weight of a silanol stopped fluid having 6.0 weight pet cent silanot and a viscosity of 35 centistokes, 10 parts by weight of 5 gm Minusil @, 1.0 parts bv weight of zinc oxide, 0.25 parts by weight magnesium oxide, 0.45 parts by weight of cerium hydroxide, and 0.12 parts by weight of black iron oxide. The formulation was thoroughly mixed while keeping the temperature under 65 OC Following the addition of the foregoing components, 0.60 parts by weight of 25 dimethyl-di-(tertiary-butvl-peroxy) hexane was added as a free radical cure catalyst and after two minutes of mixing the batch was discharged, extruded through a 150 mesh screen, press cured at 177 OC for 17 minutes and tested for physical properties. The physical properties are summarized in Table 2_ 1,,- 1 1 24 Table 2- Physical Properties of Alkenyl Gum Heat Curable Rubbers Example 12
Property Shore A 56 50 Tensile (psi) 1042 1003 Elongation % 267 316 100% Modulus (psi) 449 293 Compression Set at 22 hrs at 177 OC, % 39.7_ 18.4 Example 13:
A.n organopolysiloxane composition containing 0.6 mole % vinyl was prepared by blending in a non-heated mixer, such as a Banbury mixer, a mixture composed of 70 parts by weight of a vinyl stopped_ polydimethylsiloxane gum having a vinyl content of 225 ppm vinyl and a viscosity of 225,000 poise, 20 parts by weight of a vinyl stopped dirnethylsiloxane vinvimethyisiloxane copolymer gum having a vinyl content of 4.0 weight percent vinyl and a viscosity of 580,000 poise, 10 parts by weight of a methyl stopped polydimethyisiloxane gum having a viscosity of 225,000 poise, 0.5 parts by weight of a siloxane MQ resin where M is trimethyisilyl and the M to Q ratio ranges from between 0.8A.0 to about 0.8:15, 39 parts by weight of fumed silica having a surface hydroxyl concentration below 2-75 x 109 hydroxyls or silanols wherein the surface hydrowl concentration was reduced to below this level by treatment with octamethylcyclotetrasiloxane followed by treatment with hexamethyidisilazane having a surface area of 200 m2/g; and 15 parts by weight of 5 gm Minusil 0, the entire formulation totaling 154.5 parts by weight The formulation was thoroughly mixed keeping the temperature of the composition below about 65 OC To the mixing composition was added 0.65 parts by weight, now 155.15 parts by weight total, of 2,5-dimethvl-di-(tertiarv-butylperoxv)hexane cure catalyst After two additional rninutes of mixing the batch was discharged passed through a 150 mesh screen, press cured at 177 oC for 17 minutes and evaluated for physical properties. The physical properties of this composition are listed in Table 3. Table 3: Physical Properties of Alkenyl Gum Heat Curable Rubbers Example 11 12 13 Property Shore A 56 50 45 Tensile (psi) 1042 1003 1059 Elongation % 267 316 560 100% Modulus (psi) 449 293 135 Compression Set at 22 hrs at 177 OC, % 39.7 18.4 9.7 % Sealing Force Retention at 168 hrs valid numbers 43 at 1000 hrs not possible 27 at 2000 hrs with csr > 30 15 26
Claims (1)
- CLAIMS:1 1. A cold processable heat curable alkenyl silicone rubber composition comprising::(1) 100 parts by weight of a mixture of alkenyl silicone gums selected from the group of alkenyl silicone gums having the formula:(MaM"' 1 -.)(Dv)x(D)x(D)y(M.M' 1 -J where a is zero or one and x and y are zero or integers whereby the sum of x+y yields a gum having a viscosity ranging from 200,000 to 200,000,000 centipoise at 25'C and whereby the sum of a+x+y yields a gum 17aing an alkenyl content ranging from 0.20 to 14.00 weight percent subject to the limitation that x must be greater than zero when a is one, where M = R13Si0112 with R' selected from the group consisting of 1 to 8 carbon atom alkyl groups, phenyl, and trifluoropropyl; Mv= R(R1)2SiOl/2with R' selected from the group consisting of 1 to 8 carbon atom alkyl groups, phenyl, and trifluoropropyl and R2 selected from the group of 2 to 10 carbon atom linear or cyclic alkenyl groups; DY'= R2(R)M2,2where R' and R 2 are as previously defined; D= (P'3)2SiO2J2where each R3 is independently selected from the group consisting of 1 to 8 carbon atom alkyl groups, phenyl, and trifluoropropyl; and (2) from 0.01 to 1.5 parts by weight of a vinyl specific peroxide curing agent whereby the total weight of (1) and (2) ranges from 100.01 parts by weight to 101.5 parts by weight; and (3) from 0.0001 to 30 parts by weight of a diluent gum having the formula:MDM, and having a viscosity ranging from 200,000 to 200,000,000 centipoise at 250C.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US08/497,275 US5610213A (en) | 1995-06-30 | 1995-06-30 | Heat cured rubbers |
| GB9613663A GB2302875B (en) | 1995-06-30 | 1996-06-28 | Improved heat cured rubbers |
Publications (3)
| Publication Number | Publication Date |
|---|---|
| GB9916039D0 GB9916039D0 (en) | 1999-09-08 |
| GB2335660A true GB2335660A (en) | 1999-09-29 |
| GB2335660B GB2335660B (en) | 1999-12-01 |
Family
ID=26309595
Family Applications (2)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB9916038A Expired - Fee Related GB2335659B (en) | 1995-06-30 | 1996-06-28 | Improved heat cured rubbers |
| GB9916039A Expired - Fee Related GB2335660B (en) | 1995-06-30 | 1996-06-28 | Improved heat cured rubbers |
Family Applications Before (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB9916038A Expired - Fee Related GB2335659B (en) | 1995-06-30 | 1996-06-28 | Improved heat cured rubbers |
Country Status (1)
| Country | Link |
|---|---|
| GB (2) | GB2335659B (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP3744757A1 (en) * | 2019-05-29 | 2020-12-02 | SMP Technologies Inc. | Silicone mixture and cured product thereof |
| US10954386B2 (en) | 2019-05-29 | 2021-03-23 | Smp Technologies Inc. | Silicone admixture and cured product of the same |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113105862B (en) * | 2021-05-25 | 2022-07-15 | 哈尔滨工业大学 | A kind of preparation method of heat-resistant silicone pressure-sensitive adhesive |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3929704A (en) * | 1973-06-07 | 1975-12-30 | Gen Electric | Silicone pressure sensitive adhesives and tapes |
| EP0057098A1 (en) * | 1981-01-26 | 1982-08-04 | Blasius Industries, Inc. | High-voltage insulated connector |
| GB2096632A (en) * | 1981-04-09 | 1982-10-20 | Gen Electric | High strength heat curable silicone rubber compositions |
Family Cites Families (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR57620E (en) * | 1944-03-14 | 1953-03-20 | ||
| GB620692A (en) * | 1945-06-11 | 1949-03-29 | British Thomson Houston Co Ltd | Improvements in and relating to polymerizable polysiloxane compounds and copolymers thereof |
| GB821395A (en) * | 1956-11-01 | 1959-10-07 | Gen Electric | Improvements in alkyl aryl vinyl silicone elastomers |
| US3629297A (en) * | 1970-02-12 | 1971-12-21 | Dow Corning | Solvent-free liquid organosilicon resins |
| US4647641A (en) * | 1984-12-05 | 1987-03-03 | Pennwalt Corporation | Curable organopolysiloxane compositions |
| US4783289A (en) * | 1986-04-01 | 1988-11-08 | Toray Silicone Co., Ltd. | Process for molding silicone rubber compositions |
| DE3825676A1 (en) * | 1988-07-28 | 1990-02-15 | Wacker Chemie Gmbh | USE OF ELASTOMER HAERTBAREN ORGANOPOLYSILOXAN MASSES AS ADHESIVES |
-
1996
- 1996-06-28 GB GB9916038A patent/GB2335659B/en not_active Expired - Fee Related
- 1996-06-28 GB GB9916039A patent/GB2335660B/en not_active Expired - Fee Related
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3929704A (en) * | 1973-06-07 | 1975-12-30 | Gen Electric | Silicone pressure sensitive adhesives and tapes |
| EP0057098A1 (en) * | 1981-01-26 | 1982-08-04 | Blasius Industries, Inc. | High-voltage insulated connector |
| GB2096632A (en) * | 1981-04-09 | 1982-10-20 | Gen Electric | High strength heat curable silicone rubber compositions |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP3744757A1 (en) * | 2019-05-29 | 2020-12-02 | SMP Technologies Inc. | Silicone mixture and cured product thereof |
| US10954386B2 (en) | 2019-05-29 | 2021-03-23 | Smp Technologies Inc. | Silicone admixture and cured product of the same |
Also Published As
| Publication number | Publication date |
|---|---|
| GB2335660B (en) | 1999-12-01 |
| GB2335659A (en) | 1999-09-29 |
| GB2335659B (en) | 1999-12-01 |
| GB9916039D0 (en) | 1999-09-08 |
| GB9916038D0 (en) | 1999-09-08 |
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