Crosslinkable materials based on organyl oxysilane-terminated polymers

Abstract

Moisture curing alkoxysilyl-functional polymer compositions containing a high phenyl-content silicone resin and carbon black exhibit high adhesion to substrates, high tensile strength, very high elongation, and high tear strength without becoming unduly hard.

Claims

1. A crosslinkable composition, comprising: (A) 100 parts by weight of one or more compounds of the formula
Y[(CR.sup.1.sub.2).sub.b-SiR.sub.a(OR.sup.2).sub.3-a].sub.x (I), where Y denotes an x-valent polymer radical bonded to a carbon of the (CR.sup.1.sub.2).sub.b group via nitrogen, oxygen, sulfur or carbon, R are identical or different and represent monovalent, optionally substituted hydrocarbyl radicals, R.sup.1 are identical or different and represent hydrogen or monovalent, optionally substituted hydrocarbyl radicals which are optionally attached to the carbon atom of (CR.sup.1).sub.b via nitrogen, phosphorus, oxygen, sulfur or a carbonyl group, R.sup.2 are identical or different and represent hydrogen or a monovalent, optionally substituted hydrocarbyl radical, x is an integer from 1 to 10, a is identical or different and is 0, 1 or 2, and b is identical or different and is an integer from 1 to 10, (B) at least 5 parts by weight of at least one silicone resin comprising units of the formula
R.sup.3.sub.c(R.sup.4O).sub.dR.sup.5.sub.eSiO.sub.(4-c-d-e)/2 (II), where R.sup.3 are identical or different and denote hydrogen, a monovalent, SiC-bonded, optionally substituted aliphatic hydrocarbyl radical or a divalent, optionally substituted, aliphatic hydrocarbyl radical which bridges two units of the formula (II), R.sup.4 are identical or different and represent hydrogen or a monovalent, optionally substituted hydrocarbyl radical, R.sup.5 are identical or different and represents a monovalent, SiC-bonded, optionally substituted aromatic hydrocarbyl radical, c is 0, 1, 2 or 3, d is 0, 1, 2 or 3, and e is 0, 1 or 2, with the proviso that the sum of c+d+e is less than or equal to 3 and in at least 40% of the units of the formula (II) the sum c+e is 0 or 1, and (C) at least 10 parts by weight of carbon black.

2. The crosslinkable composition of claim 1, comprising: (A) 100 parts by weight of compounds of the formula
Y[(CR.sup.1.sub.2).sub.b-SiR.sub.a(OR.sup.2).sub.3-a].sub.x (I), where Y denotes an x-valent polymer radical bonded via nitrogen, oxygen, sulfur or carbon and comprising polyurethanes or polyoxyalkylenes as its polymer chain, R are identical or different and represent a monovalent, optionally substituted hydrocarbyl radical, R.sup.1 are identical or different and represent hydrogen or a monovalent, optionally substituted hydrocarbyl radical optionally attached to carbon via nitrogen, phosphorus, oxygen, sulfur or a carbonyl group, R.sup.2 are identical or different and represent hydrogen atom or a monovalent, optionally substituted hydrocarbyl radical, x is an integer from 1 to 10, a is identical or different and is 0, 1 or 2, and b is identical or different and is an integer from 1 to 10, (B) at least 5 parts by weight of silicone resin(s) comprising units of the formula
R.sup.3.sub.c(R.sup.4O).sub.dR.sup.5.sub.eSiO.sub.(4-c-d-e)/2 (II), where R.sup.3 are identical or different and denote hydrogen, a monovalent, SiC-bonded, optionally substituted aliphatic hydrocarbyl radical or a divalent, optionally substituted, aliphatic hydrocarbyl radical which bridges two units of the formula (II), R.sup.4 are identical or different and represent hydrogen or a monovalent, optionally substituted hydrocarbyl radical, R.sup.5 are identical or different and represent a monovalent, SiC-bonded, optionally substituted aromatic hydrocarbyl radical, c is 0, 1, 2 or 3, d is 0, 1, 2 or 3, and e is 0, 1 or 2, with the proviso that the sum of c+d+e is less than or equal to 3 and in at least 40% of the units of the formula (II) the sum c+e is 0 or 1, and (C) at least 10 parts by weight of carbon black.

3. The crosslinkable composition of claim 2, wherein component (B) comprises silicone resins (B1) which, based on the total number of units of the formula (II), have at least 30% of units of the formula (II) in which the value of e is 1 and the value of c is 0.

4. The crosslinkable composition of claim 2, wherein component (C) comprises furnace blacks.

5. The crosslinkable composition of claim 2, wherein component (C) comprises furnace blacks having a BET surface area of 30 to 600 m.sup.2/g and an oil number of between 40 and 180 ml/100 g.

6. A method for producing a composition of claim 2, comprising mixing the individual components in any order.

7. A shaped article produced by crosslinking a composition of claim 2.

8. A method for producing an assembly of materials, comprising applying a composition of claim 2 to at least one substrate, and subsequently crosslinking the composition.

9. The crosslinkable composition of claim 1, wherein component (B) comprises silicone resins (B1) which, based on the total number of units of the formula (II), have at least 30% of units of the formula (II) in which the value of e is 1 and the value of c is 0.

10. The crosslinkable composition of claim 1, wherein component (C) comprises furnace blacks.

11. The crosslinkable composition of claim 1, wherein component (C) comprises furnace blacks having a BET surface area of 30 to 600 m.sup.2/g and an oil number of between 40 and 180 ml/100 g.

12. The crosslinkable composition of claim 1, comprising: (A) 100 parts by weight of compound(s) of the formula (I), (B) 5-300 parts by weight of silicone resin(s) comprising units of the formula (II), (C) 10-200 parts by weight of carbon black, (D) 0.1-25 parts by weight of organosilicon compound(s) comprising units of the formula
D.sub.hSi(OR.sup.7).sub.gR.sup.6.sub.fO.sub.(4-f-g-h)/2 (III), in which R.sup.6 are identical or different and denote a monovalent, optionally substituted, SiC-bonded, nitrogen-free organic radical, R.sup.7 are identical or different and denote hydrogen or an optionally substituted hydrocarbyl radical, D are identical or different and denote a monovalent, SiC bonded radical having at least one nitrogen atom not bonded to a carbonyl group (CO) f is 0, 1, 2 or 3, g is 0, 1, 2 or 3, and h is 0, 1, 2, 3 or 4, with the proviso that the sum of f+g+h is less than or equal to 4 and there is at least one radical D present per molecule, (E) 10-1000 parts by weight of fillers, optionally (F) plasticizers, optionally (G) catalysts, optionally (H) adhesion promoters, optionally (I) water scavengers, optionally (J) additives, and optionally (K) adjuvants.

13. A method for producing a composition of claim 12, comprising mixing the individual components in any order.

14. A shaped article produced by crosslinking a composition of claim 12.

15. A method for producing an assembly of materials, comprising applying a composition of claim 12 to at least one substrate, and subsequently crosslinking the composition.

16. The crosslinkable composition of claim 12, comprising: (A) 100 parts by weight of compounds of the formula (I) where Y is an x-valent polymer radical which is bonded via nitrogen, oxygen, sulfur or carbon and which comprises polyurethanes or polyoxyalkylenes as its polymer chain, (B) 10-200 parts by weight of silicone resins comprising units of the formula (II) in which R.sup.5 is a phenyl radical, and which, based in each case on the total number of units of the formula (II), have at least 70% of units of the formula (II) in which e has a value of 1, (C) 20-200 parts by weight of furnace black, (D) 0.1-25 parts by weight of silanes of the formula (III), (E1) 10-900 parts by weight of calcium carbonate, magnesium carbonate and/or mixed calcium magnesium carbonates, optionally (E2) fillers differing from components (C) and (E1), optionally (F) plasticizers, optionally (G) catalysts, optionally (H) adhesion promoters, optionally (I) water scavengers, optionally (J) additives, and optionally (K) adjuvants.

17. A method for producing a composition of claim 1, comprising mixing the individual components in any order.

18. A shaped article produced by crosslinking a composition of claim 1.

19. A method for producing an assembly of materials, comprising applying a composition of claim 1 to at least one substrate, and subsequently crosslinking the composition.

Description

EXAMPLES

(1) Polymer 1: Silane-terminated polypropylene glycol having an average molar mass (M.sub.e) of 18,000 g/mol and end groups of the formula OC(O)NH(CH.sub.2).sub.3-Si(OCH.sub.3).sub.3 (available commercially under the name GENIOSIL STP-E35 from Wacker Chemie AG, Munich, DE);

(2) Carbon black 1: carbon black having a BET surface area of around 105 m.sup.2/g, an average particle size of around 25 nm, and an oil number of around 49 ml/100 g (available commercially under the name Printex 55 from Orion, Frankfurt am Main, DE);

(3) Carbon black 2: carbon black having a BET surface area of around 120 m.sup.2/g, an average particle size of around 21 nm and an oil number of around 118 ml/100 g (available commercially under the name Printex 60 from Orion, Frankfurt am Main, DE).

(4) Preparation of Phenylsilicone Resin

(5) A 2 l four-neck flask with dropping funnel, Liebig condenser, KPG stirrer, and thermometer is charged at room temperature with 1000 g of phenyltrimethoxysilane and admixed, while stirring, with 20 g of 20% strength aqueous hydrochloric acid. This initial charge is subsequently heated to a temperature of 65-68 C. until the onset of a gentle reflux. Then, under reflux, a mixture of 74 g of water and 40 g of methanol is added at a uniform rate over the course of 30 minutes. After the end of the addition, stirring is continued under reflux for 10 minutes more, after which the mixture is cooled to room temperature.

(6) The reaction mixture is left to stand at room temperature for around 16 hours, then 60 g of sodium hydrogencarbonate are added with stirring, and stirring is continued for 30 minutes, after which the resulting solid is removed by filtration. Lastly the low boilers (essentially methanol) are removed by distillation. In this procedure, initially around 80-90% of the quantity of distillate to be removed is removed at 1013 mbar and a temperature of 120 C., and then the pressure is reduced to 10 mbar and the remaining low-boiling residuals are removed by distillation over the following 15-20 minutes.

(7) The product is a phenylsilicone resin having an average molar mass Mn of 1200 g/mol, a viscosity of 90 mPas at 23 C. and a methoxy group content of 18%, based on the overall resin mass.

Inventive Example 1

(8) 143.6 g of polymer 1 are homogenized in a laboratory planetary mixer from PC-Laborsysteme, equipped with two bar mixers, at about 25 C. with 50.4 g of the above-prepared phenylsilicone resin, 72.4 g of diisodecyl phthalate as plasticizer, and 4.8 g of vinyltrimethoxysilane at 200 rpm for 2 minutes. Then 60.8 g of a chalk having a BET surface area of 15 m.sup.2/g and a d50 of 0.45 m (available commercially under the name Socal U1S2 from Solvay) and 62.8 g of carbon black 1 are incorporated with stirring at 600 rpm for one minute. Following the incorporation of carbon black and chalk, 4.8 g of N-(2-aminoethyl)aminopropyltrimethoxysilane and 0.4 g of dioctyltin dilaurate are mixed in at 200 rpm for 1 minute. Finally, under the pressure of around 100 mbar, the mixture is homogenized and stirred until free of bubbles, at 600 rpm for 2 minutes and at 200 rpm for 1 minute.

(9) The resulting composition is dispensed into 310 ml PE cartridges, provided with airtight closures, and stored at 20 C. over 24 hours prior to analysis.

Comparative Example 1 (C1)

(10) The procedure followed is as for inventive example 1 but using 194 g of polymer 1 instead of 143.6 g of polymer 1 and 50.4 g of phenylsilicone resin.

Inventive Example 2

(11) The procedure followed is as for example 1 but using 62.8 g of carbon black 2 instead of the same amount of carbon black 1.

Comparative Example 2 (C2)

(12) The procedure followed is as for inventive example 2 but using 194 g of polymer 1 instead of 143.6 g of polymer 1 and 50.4 g of phenylsilicone resin.

Inventive Example 3

(13) The compositions obtained in inventive examples 1 and 2 and in comparative examples 1 and 2 (C1 and C2) are allowed to crosslink and are analyzed for their skin formation and their mechanical properties. The results are given in Table 1.

(14) Skin Formation Time (SFT)

(15) For determination of the skin formation time, the crosslinkable compositions obtained in the examples are applied in a layer 2 mm thick to PE film and stored under standard conditions (23 C. and 50% relative humidity). In the course of the curing process, the formation of a skin is tested every 5 minutes. This is done by carefully placing a dry laboratory spatula on to the surface of the sample and pulling it in an upward direction. If the sample sticks to the spatula, a skin is yet to form. If the sample no longer sticks to the spatula, a skin has formed and the time is recorded.

(16) Mechanical Properties

(17) The compositions were each coated out onto milled Teflon plates to a depth of 2 mm and cured at 23 C., relative humidity 50, for 2 weeks.

(18) The Shore A hardness is determined according to DIN EN 53505. The tensile strength is determined according to DIN EN 53504-S1.

(19) The elongation at break is determined according to DIN EN 53504-S1.

(20) The 100% modulus is determined according to DIN EN 53504-S1. The tear resistance is determined according to ASTM D 624 B.

(21) TABLE-US-00001 TABLE 1 Composition from example 1 C1 2 C2 Carbon black [wt %] 15.7 15.7 15.7 15.7 Phenylsilicone resin [wt %] 12.6 0.0 12.6 0.0 SFT [min] 150 22 55 11 Shore A hardness 57 52 66 57 Tensile strength [N/mm.sup.2] 4.6 3.0 6.8 4.8 Elongation at break [%] 362 213 406 238 100% modulus [MPa] 1.9 1.4 2.6 2.1 Tear resistance [N/mm] 26.6 13.0 29.4 17.9

Inventive Example 4

(22) 103.6 g of polymer 1 are homogenized in a laboratory planetary mixer from PC-Laborsysteme, equipped with two bar mixers, at about 25 C. with 36.4 g of the above-prepared phenylsilicone resin, 59.2 g of a polypropylene glycol having an average molar mass M.sub.n of 2000 g/mol, 8.0 g of vinyltrimethoxysilane, and 2.0 g of a stabilizer mixture (mixture, available commercially under the name TINUVIN B 75 from BASF AG (Germany), composed of 20% Irganox 1135 (CAS No. 125643-61-0), 40% Tinuvin 571 (CAS No. 23328-53-2) and 40% Tinuvin 765 (CAS No. 41556-26-7)) at 200 rpm for 2 minutes. Then 120.0 g of a precipitated chalk coated with fatty acid and having an average particle diameter (D50%) of around 0.77 pm (available commercially under the name Hakuenka CCR S10 from Shiraishi Omya GmbH, Gummern, AT) and 66.0 g of carbon black 1 are incorporated with stirring at 600 rpm for one minute. Following the incorporation of carbon black and chalk, 4.0 g of N-(2-aminoethyl)aminopropyl-trimethoxysilane and 0.8 g of dioctyltin dilaurate are mixed in at 200 rpm for 1 minute. Finally, under the pressure of around 100 mbar, the mixture is homogenized and stirred until free of bubbles, at 600 rpm for 2 minutes and at 200 rpm for 1 minute.

(23) The resulting composition is dispensed into 310 ml PE cartridges, provided with airtight closures, and stored at 20 C. over 24 hours prior to analysis.

Inventive Example 5

(24) The procedure followed is as for inventive example 4 but using 66.0 g carbon black 2 instead of the same amount of carbon black 1.

Inventive Example 6

(25) 81.8 g of polymer 1 are homogenized in a laboratory planetary mixer from PC-Laborsysteme, equipped with two bar mixers, at about 25 C. with 18.2 g of the above-prepared phenylsilicone resin, 99.2 g of a polypropylene glycol having an average molar mass M.sub.n of 2000 g/mol, 8.0 g of vinyltrimethoxysilane, and 2.0 g of a stabilizer mixture (mixture, available commercially under the name TINUVIN B 75 from BASF AG (Germany), composed of 20% Irganox 1135 (CAS No. 125643-61-0), 40% Tinuvin 571 (CAS No. 23328-53-2) and 40% Tinuvin 765 (CAS No. 41556-26-7)) at 200 rpm for 2 minutes. Then 120.0 g of a precipitated chalk coated with fatty acid and having an average particle diameter (D50%) of around 0.77 pm (available commercially under the name Hakuenka CCR S10 from Shiraishi Omya GmbH, Gummern, AT) and 66.0 g of carbon black 1 are incorporated with stirring at 600 rpm for one minute. Following the incorporation of carbon black and chalk, 4.0 g of N-(2-aminoethyl)aminopropyl-trimethoxysilane and 0.8 g of dioctyltin dilaurate are mixed in at 200 rpm for 1 minute. Finally, under the pressure of around 100 mbar, the mixture is homogenized and stirred until free of bubbles, at 600 rpm for 2 minutes and at 200 rpm for 1 minute.

(26) The resulting composition is dispensed into 310 ml PE cartridges, provided with airtight closures, and stored at 20 C. over 24 hours prior to analysis.

Inventive Example 7

(27) The procedure followed is as for inventive example 6 but using 66.0 g carbon black 2 instead of the same amount of carbon black 1.

Inventive Example 8

(28) The compositions obtained in inventive examples 4 to 7 are allowed to crosslink and are analyzed for their skin formation and their mechanical properties in accordance with the methods specified in example 3. The results are given in Table 2.

(29) TABLE-US-00002 TABLE 2 Composition from example 4 5 6 7 SFT [min] 58 25 106 62 Shore A hardness 67 74 54 62 Elongation at break [%] 502 285 549 434 Tensile strength [N/mm.sup.2] 5.9 5.6 4.3 4.9 100% modulus [MPa] 2.4 3.5 1.3 2.1 Tear resistance [N/mm] 42.9 28.5 31.2 36.5