WO2011039318A1

WO2011039318A1 - A silicone rubber composition and a silicone rubber

Info

Publication number: WO2011039318A1
Application number: PCT/EP2010/064580
Authority: WO
Inventors: Yuhai Sun; Yong Zhang
Original assignee: Henkel Ag & Co. Kgaa
Priority date: 2009-09-30
Filing date: 2010-09-30
Publication date: 2011-04-07
Also published as: CN102030993A

Abstract

The invention discloses a silicone rubber composition, comprising a silicone oil having an acetoacetylamino or acetoacetoxy group, and a curing agent, wherein the curing agent is one or more compounds selected from the group consisting of an isocyanate compound, an amino compound, an acrylate compound and an ionic organic compound. The invention also discloses a silicone rubber. The silicone rubber is obtained by a novel curing method wherein a silicone oil having an acetoacetylamino or acetoacetoxy group is used as starting material, and the acetoacetyl group of the silicone oil reacts with other reactive compound. The curing method is environment-friendly by overcoming the problems of catalyst poisoning and release of small organic molecules. In addition, the silicone rubber according to the invention can be widely used in the aspects of sealant, adhesive, coatings, potting material, and coating.

Description

A silicone rubber composition and a silicone rubber

The present invention relates to a silicone rubber composition and a silicone rubber.

Silicone rubber has good properties in terms of resistance to high and low temperature, electrical insulation, weather resistance, ozone resistance, gas permeability, transparency, tearing strength, heat dissipation, adhesion, flowing property and mold releasing, and is widely used in a variety of applications including electrical, transportation, aviation, medical, construction applications.

Nowadays, the commonly used silicone rubber is typically cured by means of either addition or condensation. The addition curing method is carried out by hydrosilylation, and the condensation curing method is carried out by hydrolysis and condensation of alkoxyl group. The condensation curing method is generally believed to be not very environment-friendly, due to small organic molecules released in the hydrolysis of alkoxyl group. The addition curing method usually requires the use of an organic metallic compound such as platinum, tin or platinum complex as a catalyst, which not only increases the cost of the system, but may also cause problems in certain applications, such as catalyst poisoning, incomplete catalyzing, sometimes incomplete or even no curing. Furthermore, the organic metallic compound used as the catalyst is not much satisfactory from the viewpoint of environmental protection.

The object of the invention is to provide a silicone rubber composition and a silicone rubber, in order to overcome the drawbacks of the conventional curing methods of silicone rubber, including being non-environment-friendly, susceptibility of catalyst to poisoning, incomplete or even no curing. The present invention is based on the idea that a cured silicone rubber is obtainable via a novel curing method wherein a silicone oil containing one or more acetoacetyl groups is crosslinked by reaction with an appropriate reactive compound.

The inventors have found that various crosslinking mechanisms can be effected by incorporation of one or more acetoacetyl group into the backbone chain of a silicone oil. Specifically, an amide structure can be produced from the acetoacetyl group and an isocyanate (reaction scheme-1 ); the acetoacetyl group can undergo a Michael addition reaction with an acrylate group in the presence of a base catalyst (reaction scheme-2); the acetoacetyl group can undergo chelation with an ion (reaction scheme-3); the acetoacetyl group can undergo a keto-enol tautomerism (reaction scheme-4) to produce an enol structure which is reactive with an amino group (reaction scheme-5). By utilizing these chemical reactions, room temperature addition curing of a silicone oil having at least one acetoacetylamino or acetoacetoxy group can be achieved, during which no small molecules and no VOCs are released and by which the aim of environmental protection can be reached; and high temperature addition curing of a silicone oil having at least one acetoacetylamino or acetoacetoxy group can also be achieved, in which no expensive noble metal catalyst is required, and thus the problems associated with the catalyst, such as catalyst poisoning, will not occur. In addition, curing by means of complexation can introduce an ion into the curing system, thereby improving electrical and thermal properties of the system. Therefore, the silicone rubber obtained according to the invention can be widely used in the aspects of sealants, adhesives, coatings and/or potting materials.

Reaction scheme-1:

Reaction scheme-2:

Reaction scheme-4:

Reaction scheme-5

The present invention relates to a silicone rubber composition comprising a silicone oil having at least one acetoacetylamino or acetoacetoxy group, and a curing agent, wherein the curing agent is one or more compounds selected from the group consisting of an isocyanate compound, an amino compound, an acrylate compound and an ionic organic compound. The curing of such composition can be carried out in an environment-friendly way simultaniuously overcoming the problems of catalyst poisoning and release of small organic molecules. In addition, the present invention relates to the use of the silicone rubber composition according to the invention as a sealant, adhesive, coating and/or potting material. The silicone rubber composition of the present invention may comprise a silicone oil having an acetoacetylamino or acetoacetoxy group, and a curing agent, wherein the curing agent is one or more compounds selected from the group consisting of an isocyanate compound, an amino compound, an acrylate compound and an ionic organic compound.

According to the invention, the ratio of the silicone oil having at least one acetoacetylamino or acetoacetoxy group and the curing agent is calculated on the basis of the molar ratio of the entirety of the acetoacetyl groups of the silicone oil having at least one acetoacetylamino or acetoacetoxy group and the entirety of the reactive groups of the curing agent in the reaction therebetween. Preferably, the molar ratio of the reactive groups of the curing agent to the acetoacetyl groups of the silicone oil having at least one acetoacetylamino or acetoacetoxy group is 1 : 10 - 2: 1 , more preferably 1 :5 - 1.5: 1. The reactive group varies with the curing agent. For example, the reactive group of an isocyanate compound is an isocyanate group; the reactive group of an acrylate compound is an acrylate group; the reactive group of an amino compound is an amino group; and the reactive group of an ionic organic compound is a metal ion or boron ion.

If the curing agent is an isocyanate compound, the molar ratio of the isocyanate groups of the isocyanate compound to the acetoacetyl groups of the silicone oil having at least one acetoacetylamino or acetoacetoxy group is preferably 1 :2 - 1 .5: 1 , more preferably 0.8: 1 - 1.2:1.

If the curing agent is an acrylate compound, the molar ratio of the acrylate groups of the acrylate compound to the acetoacetyl groups of the silicone oil having at least one acetoacetylamino or acetoacetoxy group is preferably 1 :5 - 1 .7: 1 , more preferably 0.4: 1 - 1.5:1.

If the curing agent is an amino compound, the molar ratio of the amino groups of the amino compound to the acetoacetyl groups of the silicone oil having at least one acetoacetylamino or acetoacetoxy group is preferably 1 :2 - 1.5: 1 , more preferably 0.8: 1 - 1.2: 1.

If the curing agent is an ionic organic compound, the molar ratio of the ions of the ionic organic compound to the acetoacetyl groups of the silicone oil having at least one acetoacetylamino or acetoacetoxy group is preferably 1 :10 - 1.5: 1 , more preferably 1 :5 - 1.2: 1.

According to the invention, the silicone oil having at least one acetoacetylamino or acetoacetoxy group is preferably a homopolymer or copolymer having the following structural formula (I) or (II): Formula (I)

wherein, p is an integer of from 0 to 2000, q is an integer of from 0 to 500, the sum of p and q is greater than 0; r and s may be identical or different, and are both an integer of from 0 to 3, and the sum of q, s and r is greater than 1 ;

R-i , R₆ and R₈ each independently represent a divalent radical selected from a C-1-C12 hydrocarbylene radical, a C₄-C₂o cyclohydrocarbylene radical, a C₆-C₂o arylene radical, a C7-C20 hydrocarbylene aryl radical, a C₅-C₂o hydrocarbylene amino radical, a C₅-C₂₀ amino hydrocarbylene radical, -R₉COOR₁₀-, -R-1-1OR15-, or any combination thereof, wherein R₉, R₁₀, Rn and R₁₅ each represent a hydrocarbylene radical, the total number of carbon atoms of each of R₉ and R ₀, or of each of R and R ₅ being 5-20. R-i , R₆ and R₈ each independently preferably represent a Ci-Ci₂ hydrocarbylene radical, more preferably a propylene radical.

R₃, R₄ and R₅ each independently represent a Ci-Ci₂ alkyl radical, a C₆-C₂₀ cycloalkyl radical, a C₆-C₂₀ aryl radical, a C₆-C₂₀ aralkyl radical, a C₆-C₂₀ alkaryl radical, C₂-C₁₂ alkenyl radical, or any combination thereof, preference being given to a Ci-Ci₂ alkyl radical or a C₆-C₂₀ aryl radical, more preferably to a methyl radical. R₂ and R₇ each independently represent a Ci-Ci₂ alkyl radical, a C₆-C₂o cycloalkyl radical, a C₆-C₂o aryl radical, a C₆-C₂o aralkyl radical, a C₆-C₂o alkaryl radical, Ci-Ci₂ alkoxyl radical, R₁₃COORi₄-,

having in total 1 -12 carbon atoms, C₂-C₁₂ alkenyl radical, or any combination thereof, wherein R ₃, R ₄ and R₁₆ each represent a hydrocarbon radical, and the total number of carbon atoms of each of R₁₃ and R₁₄ is 5-12; preference being given to a hydrocarbon radical having 1-12 carbon atoms or a C₆-C₂₀ aryl radical, more preferably to a methyl radical.

The silicone oil having at least one acetoacetylamino or acetoacetoxy group preferably has a

weight-average molecular weight of 500-500000. According to the invention, the weight-average molecular weight is determined by gel permeation chromatography (GPC) on a Perkin-Elmer-200 series GPC-device equipped with binary pump, autosampler and refractive index detector. THF is used as the solvent, the flow rate is 0.8 l/min. 3 PIgel Mixed-D columns in series (Polymer laboratories, 7.5x300mm; particle size of packing material: 5μιη; linear range to M_w of 400,000) are used. The column/RI temperature is 35°C; the samples are prepared as 2.5 mg/ml THF. The injection volume is 100 μΙ. PS is used as narrow standard.

According to the invention, the isocyanate compound is preferably one or more common isocyanates selected from the group consisting of methylene diphenyl diisocyanate (MDI), toluene diisocyanate (TDI), hexamethylene diisocyanate (HDI), isophorone diisocyanate (IPDI), dicyclohexylmethane diisocyanate, naphthalene diisocyanate, p-phenylene diisocyanate, cyclohexane diisocyanate, tetramethyl m-xylylene diisocyanate, 2,5-bis(isocyanatomethyl)bicyclo[2,2,1 ] heptane, 2,6-bis(isocyanatomethyl)

bicycle[2,2, 1]heptane, norbornane diisocyanate, 4,4'-methylene diphenyl diisocyanate, toluene diisocyanate, 1 ,6-hexane diisocyanate, tetramethyl xylylene diisocyanate, triphenyl methane diisocyanate, methylcyclohexyl diisocyanate, and crude MDI, most preferably is crude MDI.

According to the invention, the amino compound preferably is a compound having two or more amino groups (the amino group including NH₂, secondary amino group and tertiary amino group), and more preferably is one or more of amino silicone oil, polyether amine, vinylamine and polyamide, the example being one or more of amino-terminated silicone oil having various molecular weight, polyamino silicone oil having various molecular weight, amino-terminated polyether having various molecular weight, and polyaminopolyether amine having various molecular weight.

The acrylate compound preferably is a compound having two or more acrylate groups,

more preferably one or more of a diacrylate, a triacrylate and a tetraacrylate. The diacrylate is preferably one or more of (octahydro-4,7-methano-1 H-indene-1 ,5-diyl) bis(methylene) diacrylate, diethylene glycol diacrylate, ethoxylated bisphenol A diacrylate, 1 ,6-hexanediol diacrylate and polyethylene glycol diacrylate. The triacrylate is preferably one or more of trimethylolpropane triacrylate, ethoxylated trimethylolpropane triacrylate, propoxylated glycerin triacrylate, tris(2-hydroxyethyl) isocyanate triacrylate, and pentaerythritol triacrylate, etc. The tetraacrylate is preferably pentaerythritol tetraacrylate, etc. If the acrylate compound is used as the curing agent, a suitable amount of a catalyst may be added to accelerate the reaction, the catalyst being suitably one commonly used in Michael addition reaction, preferably one or more of triethylamine, piperidine, hydroxide, sodium ethylate and benzyl triethyl ammonium chloride.

The ionic organic compound preferably is an organic compound containing a metal element or boron, more preferably a titanate and/or a borate. The titanate is preferably one or more of isopropyl titanate, tetrabutyl titanate, isopropyl triisostearoyltitanate, isopropyl trioleoyl titanate, diisopropoxylated

bis(trimethyl siloxy) titanate and titanium bis(triethanolamine) diisopropoxide. The borate is preferably one or more of trimethyl borate, triethyl borate, tri-n-propyl borate, triisopropyl borate, tri-n-butyl borate and tricyclohexyl borate.

Depending on the types of the curing reaction occurring between the mixed components, in addition to the silicone oil having at least one acetoacetylamino or acetoacetoxy group and the curing agent, the silicone rubber composition according to the invention may comprise a small amount of a catalyst, in order to facilitate the proceeding of the reaction.

The silicone rubber composition may further comprise reinforcing particles such as inorganic particles, for example silicon dioxide, calcium carbonate or titanium dioxide, in order to enhance the mechanical strength of the cured silicone rubber.

The silicone rubber composition may further comprise such a filler and/or an auxiliary agent as to impart the composition certain particular properties such as thermal or electrical property after the components are mixed and cured. For example, inorganic particles such as aluminium oxide, magnesium oxide, silicon nitride may be added to improve the thermal conductivity of the system, and carbon fiber, aluminium powder or Ag-powder may further be added to improve the electrical conductivity of the system, thereby obtaining an electrically conductive silicone rubber.

The silicone rubber composition may further comprise one or more auxiliary agents for improving properties, such as a viscosity increaser or a viscosity reducer. The preferred auxiliary agent should have good compatibility with the silicone rubber composition and will not affect the practice of the invention. According to the invention, the silicone rubber composition may be packaged as a multi-component kit with the individual ingredients separately stored or grouped into several parts, or as a mixture wherein the mixed ingredients undergo no curing or an incomplete curing. If the silicone rubber composition is packaged as a multi-component kit, the silicone oil having at least one acetoacetylamino or acetoacetoxy group and the curing agent are not contained in one component simultaneously. As an example, the silicone rubber composition may be packaged as a two-component kit comprising a silicone oil having at least one acetoacetylamino or acetoacetoxy group and a curing agent. As a further example, the silicone rubber composition may be packaged as a three-component kit comprising a silicone oil having at least one acetoacetylamino or acetoacetoxy group, a curing agent, and a catalyst.

The present invention further relates to a silicone rubber, which is a mixture obtained by mixing and curing the ingredients of the aforementioned silicone rubber composition.

According to the invention, the silicone rubber is prepared by mixing the individual ingredients of the silicone rubber composition, and allowing the curing to proceed at room temperature or a specific curing temperature for a period of time. The specific curing temperature and time can be determined according to the conventional knowledge in the art, depending on the reaction type.

The procedure for the preparation of the silicone rubber is described in detail as follows: the silicone oil having at least one acetoacetylamino or acetoacetoxy group, the curing agent and additional desired components (for example a catalyst, reinforcing particles or conductive particles) are thoroughly mixed, and the resulting mixture can be cured under a specific condition, thereby obtaining the silicone rubber. According to different requirements, the silicone rubber thus obtained may be used as a sealant, an adhesive, a coating, a potting material or an elastomer, preferably as an adhesive. When used as a coating, the silicone rubber is preferably applied in a way that the individual ingredients of the silicone rubber composition are homogeneously mixed, applied to a substrate, and then cured to form a silicone rubber without contact with other substrates.

Unless otherwise indicated, the following terms used in the description and claims have the following definitions:

The term "hydrocarbylene radical" means a branched or linear, saturated or unsaturated aliphatic hydrocarbon radical having the specified number of carbon atoms, which is connected to the backbone molecule via two suitable atoms.

The term "cyclohydrocarbylene radical" means a saturated or unsaturated cycloaliphatic hydrocarbon radical having the specified number of carbon atoms, which is connected to the backbone molecule via two suitable atoms.

The term "alkyl radical" means a branched or linear saturated aliphatic hydrocarbon radical having the specified number of carbon atoms. For example, "C-rC-io alkyl radical" means a saturated aliphatic hydrocarbon radical having 1 , 2, 3, 4, 5, 6, 7, 8, 9 or 10 carbon atoms in the linear or branched structure, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, t-butyl, isobutyl, pentyl, hexyl, heptyl, octyl, nonyl and decyl etc.

The term "cycloalkyl radical" means a saturated or partially unsaturated monocyclic, polycyclic or bridged carbon ring substituent. For example, "C3-C10 cycloalkyl radical" means a ring having 3-10 carbon atoms, such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl,

1 ,2,3,4-tetrahydro-naphthyl, and bicyclo[2.2.2] octyl. The cycloalkyl radical is connected to the backbone molecule via a saturated carbon atom.

The term "aryl radical" means any stable monocyclic or polycyclic carbon ring having up to 7 carbon atoms in the individual ring(s), wherein at least one ring is an aromatic ring, such as phenyl, naphthyl, tetrahydronaphthyl, 2,3-dihydroindenyl, biphenyl, phenanthryl, anthranyl, or acenaphthenyl. In the case of a polycyclic aryl radical in which a ring is non-aromatic, it is connected to the backbone molecule via a carbon atom of an aromatic ring.

The term "aralkyl radical" means a radical consisting of an alkyl radical bearing an aryl radical as a substituent which is connected to the backbone molecule via a carbon atom of the alkyl-part of the radical. The term "alkaryl radical" means a radical consisting of an aryl radical bearing an alkyl radical as asubstituent, which is connected to the backbone molecule via a carbon atom of the aryl-part of the radical.

The phrase "any combination thereof means a new radical formed by connection of two or more of the mentioned radicals.

Unless specifically stated, all materials and reagents involved in the invention are commercially available. The invention is advantageous in that a silicone rubber is obtained by a novel curing method wherein a silicone oil having at least one acetoacetylamino or acetoacetoxy group is used as starting material, and the acetoacetyl group of the silicone oil reacts with another reactive compound. The curing method is environment-friendly by overcoming the problems of catalyst poisoning and release of small organic molecules. In addition, the silicone rubber according to the invention can be widely used in the aspects of a sealant, an adhesive, a coating and/or a potting material.

Reference Examples 1-4 illustrate the preparation of a silicone oil having an acetoacetylamino or acetoacetoxy group.

Reference Example 1 : Preparation of 4SDA-A

In a 500ml three-necked flask equipped with a stirrer, a vent stopper and a constant pressure funnel, 7.9g (50mmol) t-butyl acetoacetate was dissolved in 200ml toluene, heated to the temperature of 105°C, and sparged with nitrogen. With stirring, a solution of 70g 4SDA (mole amount of amino group: 35mmol, weight-average molecular weight Mw: 4000, nitrogen content: 7.0%, product from Henkel Corporation), an amino-containing silicone oil, in 100ml toluene was added dropwise. After the completion of the dropwise addition, the temperature was maintained for 1 hour, to ensure the reaction went to completion. After the completion of the reaction, the solvent and residual starting materials were removed by distilling the reaction mixture under a reduced pressure at the temperature of 140°C, and 72.5g target product, 4SDA-A silicone oil, was obtained, with the yield being 96%.

Reference Example 2: Preparation of 8136-A

In a 500ml three-necked flask equipped with a stirrer, a vent stopper and a constant pressure funnel, 7.9g (50mmol) t-butyl acetoacetate was dissolved in 100ml toluene, heated to the temperature of 105°C, and sparged with nitrogen. With stirring, a solution of 92g 2-8136A (mole amount of amino group: 20mmol, weight-average molecular weight Mw: 12000, nitrogen content: 0.3%, product from Dow Corning Corporation), an amino-containing silicone oil, in 100ml toluene was added dropwise. After the completion of the dropwise addition, the temperature was maintained for 1 hour, to ensure the reaction went to completion. After the completion of the reaction, the solvent and residual starting materials were removed by distilling the reaction mixture under a reduced pressure at the temperature of 140°C, and 92. Og target product, 8136-A silicone oil, was obtained, with the yield being 97%. Reference Example 3: Preparation of 2311-A

In a 250ml three-necked flask equipped with a stirrer, a vent stopper and a constant pressure funnel, 6.32g (40mmol) t-butyl acetoacetate was dissolved in 100ml toluene, heated to the temperature of 105°C, and sparged with nitrogen. With stirring, a solution of 5g H-Si 2311 (mole amount of hydroxy group: 4mmol, weight-average molecular weight Mw: 2500, hydroxy content: 1.36%, product from Evonik Corporation), an alkylhydroxy-containing silicone oil, in 80ml toluene was added dropwise. After the completion of the dropwise addition, the temperature was maintained for 1 hour, to ensure the reaction went to completion. After the completion of the reaction, the solvent and residual starting materials were removed by distilling the reaction mixture under a reduced pressure at the temperature of 140°C, and 5.2g target product, 2311-A silicone oil, was obtained, with the yield being 96%.

Reference Example 4: Preparation of 209Z-A

In a 250ml three-necked flask equipped with a stirrer, a vent stopper and a constant pressure funnel, 7.0g (43mmol) t-butyl acetoacetate was dissolved in 50ml toluene, heated to the temperature of 105°C, and sparged with nitrogen. With stirring, a solution of 100g 209Z (mole amount of amino group: 30mmol, hydroxy content: 0.49%, product from United Chemical Company), an amino-containing silicone oil, in 60ml toluene was added dropwise. After the completion of the dropwise addition, the temperature was maintained for 1 hour, to ensure the reaction went to completion. After the completion of the reaction, the solvent and residual starting materials were removed by distilling the reaction mixture under a reduced pressure at the temperature of 140°C, and 97.3g target product, 209Z-A silicone oil, was obtained, with the yield being 92%.

Examples 1-5 illustrate the preparation of a silicone rubber.

The stress-strain analysis of the specimen is performed at room temperature using Diamond DMA Instrument from PerkinElmer Corporation, at a stretching rate of 5μΝ/ιτπη.

Unless stated otherwise, all tests are carried out at ambient pressure, and at ambient temperature and a relative humidity of 50%. Example 1 :

20g 4SDA-A (mole amount of acetoacetylamino group: 10mmol, weight-average molecular weight Mw: 4000), 2g crude MDI and 4g triethylamine were mixed by using a speed mixer at 3000 rmp for 1 min, poured into a mold, and left to stand at room temperature for 30 min, allowing to cure. The cured specimen had a Shore hardness of 7°, tensile strength of 0.15 MPa, and elongation at break of 42%.

Example 2:

20g 4SDA-A (mole amount of acetoacetylamino group: 10mmol, weight-average molecular weight Mw: 4000) and 1 .5g SR-386 (tris(2-hydroxyethyl) isocyanate triacrylate, product from Sartomer Company) were stirred homogenously, poured into a mold, and cured at the temperature of 150°C for 4 hours. The cured specimen had a Shore hardness of 17°, tensile strength of 0.22 MPa, and elongation at break of 130%.

Example 3:

20g 209Z-A (mole amount of acetoacetylamino group: 17.5mmol, weight-average molecular weight Mw: 35000), 4g crude MDI and 2g triethylamine were mixed by using speed mixer at 2000 rmp for 3 min, poured into a mold, and left to stand at room temperature for 7 hours, allowing to cure. The cured specimen had a Shore hardness of 18°, tensile strength of 0.24 MPa, and elongation at break of 80%.

Example 4:

20g 209Z-A (mole amount of acetoacetylamino group: 17.5mmol, weight-average molecular weight Mw: 35000) and 2.5g SR-833 ((octahydro-4,7-methano-1 H-indene-1 ,5-diyl)bis(methylene)) diacrylate, product from Sartomer Company) were stirred homogeneously, poured into a mold, and cured at the temperature of 150°C for 4 hours. The cured specimen had a Shore hardness of 8°, tensile strength of 0.06 MPa, and elongation at break of 260%.

Example 5:

6g 4SDA-A (mole amount of acetoacetylamino group: 3mmol, weight-average molecular weight Mw: 4000) and 4.6g 209C (an amino silicone oil having an amino content of 0.9%, product from JiaXing United Chemical Company) were mixed homogeneously by using speed mixer, and cured at room temperature for 1 min. The cured specimen had a Shore hardness of 12°, tensile strength of 0.037 MPa, and elongation at break of 212%.

Example 6:

5g 209Z-A (mole amount of acetoacetylamino group: 1.5mmol, weight-average molecular weight Mw: 35000) and 5g 209C (an amino silicone oil having an amino content of 0.9%, product from JiaXing United Chemical Company) were mixed homogeneously, and cured at room temperature for 3min. The cured specimen had a Shore hardness of 34°, tensile strength of 0.008 MPa, and elongation at break of 8%.

Example 7:

3g 8136-A (mole amount of acetoacetylamino group: 0.5mmol, weight-average molecular weight Mw: 12000) and 0.11g tetrabutyl titanate were mixed homogeneously, and cured at room temperature for 1 min. The cured specimen had a Shore hardness of 17°, tensile strength of 0.003 MPa, and elongation at break of 35%.

Example 8:

1g 4SDA-A (mole amount of acetoacetylamino group: 0.5mmol, weight-average molecular weight Mw: 4000) and 0.04g tetrabutyl titanate were mixed homogeneously, and cured at room temperature for 1 min. The cured specimen had a Shore hardness of 10°, tensile strength of 0.002 MPa, and elongation at break of 22%.

Example 9:

1g 4SDA-A (mole amount of acetoacetylamino group: 0.5mmol, weight-average molecular weight Mw: 4000) and 1.4g UC209-51 AM (an amino silicone oil having an amino content of 0.5%, product from JiaXing United Chemical Company) were mixed homogeneously, and cured at room temperature for 5min. The cured specimen had a Shore hardness of 9°, tensile strength of 0.078 MPa, and elongation at break of 12%.

Example 10:

2g 4SDA-A (mole amount of acetoacetylamino group: 1 mmol, weight-average molecular weight Mw: 4000) and 2.8g UC209-51AM (an amino silicone oil having an amino content of 0.5%, product from JiaXing United Chemical Company) were mixed homogeneously with 1g R-8200 fumed silica (from Evonik Degussa Company), and cured at room temperature for 3min. The cured specimen had a Shore hardness of 15°, tensile strength of 0.279 MPa, and elongation at break of 145%.

Example 11 :

4g 8136-A (mole amount of acetoacetylamino group: 0.5mmol, weight-average molecular weight Mw: 12000) and 0.81 g D2000 (a polyether amine having a molecular weight of 2000 and an amino content of

I .4%, product from Huntsman Chemical Corporation) were mixed homogeneously, and cured at room temperature for 2 days. The cured specimen had a Shore hardness of 8°, tensile strength of 0.012 MPa, and elongation at break of 147%.

Example 12:

4g 8136-A (mole amount of acetoacetylamino group: 0.5mmol, weight-average molecular weight Mw: 12000), 0.08g pentaerythritol tetraacrylate, and 0.02g benzyl triethyl ammonium chloride were mixed homogeneously, and cured at the temperature of 60°C for 8 hours. The cured specimen had a Shore hardness of 12°, tensile strength of 0.002 MPa, and elongation at break of 20%.

Example 13:

4g 8136-A (mole amount of acetoacetylamino group: 0.5mmol, weight-average molecular weight Mw: 12000) and 0.12g T403 (a polyether amine having a molecular weight of 403 and an amino content of

I I .9%, product from Huntsman Chemical Corporation) were mixed homogeneously, and cured at room temperature for 3 hours. The cured specimen had a Shore hardness of 6°, tensile strength of 0.006 MPa, and elongation at break of 112%.

Example 14:

3g 2311-A (mole amount of acetoacetoxy group: 2.4mmol, weight-average molecular weight Mw: 2500) and 6.11g UC209-06 (an amino silicone oil having an amino content of 0.55%, product from JiaXing United Chemical Company) were mixed homogeneously, and cured at room temperature for 10min. The cured specimen had a Shore hardness of 17°, tensile strength of 0.012 MPa, and elongation at break of 9%. Example 15:

6g 2311-A (mole amount of acetoacetoxy group: 4.8mmol, weight-average molecular weight Mw: 2500) and 7.6g 209C (an amino silicone oil having an amino content of 0.9%, product from JiaXing United Chemical Company) were mixed homogeneously, and cured at room temperature for 7min. The cured specimen had a Shore hardness of 7°, tensile strength of 0.03 MPa, and elongation at break of 40%.

Claims

What is claimed is:

1. A silicone rubber composition, characterized in that the composition comprises a silicone oil having at least one acetoacetylamino or acetoacetoxy group and a curing agent, wherein the curing agent is one or more compounds selected from the group consisting of an isocyanate compound, an amino compound, an acrylate compound and an ionic organic compound.

2. The silicone rubber composition according to claim 1 , characterized in that the molar ratio of reactive groups of the curing agent to the acetoacetyl groups of the silicone oil having at least one

acetoacetylamino or acetoacetoxy group is 1 : 10 - 2: 1.

3. The silicone rubber composition according to claim 1 , characterized in that

if the curing agent is an isocyanate compound, the molar ratio of the isocyanate groups of the isocyanate compound to the acetoacetyl groups of the silicone oil having at least one acetoacetylamino or acetoacetoxy group is 1 :2 - 1.5:1 ;

if the curing agent is an acrylate compound, the molar ratio of the acrylate groups of the acrylate compound to the acetoacetyl groups of the silicone oil having at least one acetoacetylamino or acetoacetoxy group is 1 :5 - 1.7: 1 ;

if the curing agent is an amino compound, the molar ratio of the amino groups of the amino compound to the acetoacetyl groups of the silicone oil having at least one acetoacetylamino or acetoacetoxy group is 1 :2 - 1.5: 1 ; and

if the curing agent is an ionic organic compound, the molar ratio of the ions of the ionic organic compound to the acetoacetyl groups of the silicone oil having at least one acetoacetylamino or acetoacetoxy group is 1 :10 - 1.5: 1.

4. The silicone rubber composition according to any of the preceding claims, characterized in that the silicone oil having at least one acetoacetylamino or acetoacetoxy group is a homopolymer or copolymer having the following structural formula (I) or (II):

Formula (I)

wherein p is an integer of from 0 to 2000, q is an integer of from 0 to 500, the sum of p and q is greater than 0; r and s may be identical or different, and are both an integer of from 0 to 3, and the sum of q, s and r is greater than 1 ;

R-i , R₆ and R₈ each independently represent a divalent radical selected from a C1-C12 hydrocarbylene radical, a C₄-C₂o cyclohydrocarbylene radical, a C₆-C₂o arylene radical, a C7-C20 hydrocarbylene aryl radical, a C₅-C₂o hydrocarbylene amino radical, a C₅-C₂₀ amino hydrocarbylene radical, -R9COOR10-, -R-1-1OR15-, or any combination thereof, wherein R₉, R₁₀, Rn and R₁₅ each represent a hydrocarbylene radical, the total number of carbon atoms of R₉ and R₁₀, or Rn and R₁₅ being 5-20;

R₃, R₄ and R₅ each independently represent a Ci-Ci₂ alkyl radical, a C₆-C₂₀ cycloalkyl radical, a C₆-C₂₀ aryl radical, a C₆-C₂₀ aralkyl radical, a C₆-C₂₀ alkaryl radical, C₂-Ci₂ alkenyl radical, or any combination thereof;

R₂ and R₇ each independently represent a C-|-Ci₂ alkyl radical, a C₆-C₂₀ cycloalkyl radical, a C₆-C₂₀ aryl radical, a C₆-C₂o aralkyl radical, a C₆-C₂o alkaryl radical, C₁-C₁₂ alkoxyl radical, R₁₃COORi₄-,

having 1-12 carbon atoms in total, C₂-Ci₂ alkenyl radical, or any combination thereof, wherein R₁₃, R₁₄ and R₁₆ each represent a hydrocarbon radical, and the total number of carbon atoms of R₁₃ and R₁₄ is 5-12.

5. The silicone rubber composition according to claim 4, characterized in that R-i , R₆ and R₈ each independently represent a C₁-C₁₂ hydrocarbylene radical.

6. The silicone rubber composition according to claim 4 or 5, characterized in that R₃, R₄ and R₅ each independently represent a C₁-C₁₂ alkyl radical or a C₆-C₂o aryl radical.

7. The silicone rubber composition according to any of claims 4-6, characterized in that R₂ and R₇ each independently represent a hydrocarbon radical having 1-12 carbon atoms or a C₆-C₂o aryl radical.

8. The silicone rubber composition according to any of claims 1 to 7, characterized in that the silicone oil having at least one acetoacetylamino or acetoacetoxy group has a weight-average molecular weight of 500-500000.

9. The silicone rubber composition according to any of the preceding claims, characterized in that the isocyanate compound is one or more of methylene diphenyl diisocyanate, toluene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, dicyclohexylmethane diisocyanate, naphthalene diisocyanate, p-phenylene diisocyanate, cyclohexane diisocyanate, tetramethyl m-xylylene diisocyanate, 2,5-bis(isocyanatomethyl)bicyclo[2,2,1]heptane, 2,6-bis (isocyanatomethyl) bicyclo[2,2, 1]heptane, norbornane diisocyanate, 4,4'-methylene diphenyl diisocyanate, toluene diisocyanate, 1 ,6-hexane diisocyanate, tetramethyl xylylene diisocyanate, triphenyl methane diisocyanate, methylcyclohexyl diisocyanate, and crude methylene diphenyl diisocyanate.

10. The silicone rubber composition according to any of the preceding claims, characterized in that the amino compound is one or more of amino silicone oil, polyether amine, vinylamine and polyamide.

11. The silicone rubber composition according to any of the preceding claims, characterized in that the acrylate compound is one or more of a diacrylate, a triacrylate and a tetraacrylate.

12. The silicone rubber composition according to claim 11 , characterized in that the diacrylate is one or more of (octahydro-4,7-methano-1 H-indene-1 ,5-diyl) bis(methylene) diacrylate, diethylene glycol diacrylate, ethoxylated bisphenol A diacrylate, 1 ,6-hexanediol diacrylate and polyethylene glycol diacrylate; the triacrylate is one or more of trimethylolpropane triacrylate, ethoxylated

trimethylolpropane triacrylate, propoxylated glycerin triacrylate, tris(2-hydroxyethyl) isocyanate triacrylate, and pentaerythritol triacrylate; and the tetraacrylate is pentaerythritol tetraacrylate.

13. The silicone rubber composition according to any of the preceding claims, characterized in that the curing agent comprises an acrylate compound and the silicone rubber composition further comprises a catalyst commonly used in a Michael addition reaction.

14. The silicone rubber composition according to any of the preceding claims, characterized in that the ionic organic compound is a titanate and/or a borate.

15. The silicone rubber composition according to claim 14, characterized in that the titanate is one or more of isopropyl titanate, tetrabutyl titanate, isopropyl triisostearoyltitanate, isopropyl trioleoyl titanate, diisopropoxylated bis(trimethyl siloxy) titanate, and titanium bis(triethanolamine) diisopropoxide; and the borate is one or more of trimethyl borate, triethyl borate, tri-n-propyl borate, triisopropyl borate, tri-n-butyl borate, and tricyclohexyl borate.

16. A silicone rubber, characterized in that the silicone rubber is a mixture obtained by mixing and curing all the ingredients of a silicone rubber composition according to any of the preceding claims.