CN102827479A - Liquid silicone rubber - Google Patents

Abstract

The present invention relates to a liquid silicone rubber, which is composed of (i) organopolysiloxane containing aliphatic unsaturated groups, (ii) organopolysiloxane containing silicon-bonded hydrogen atoms, (iii) white carbon black, (iv) Platinum catalyst and (v) alkyne group-containing inhibitor, mixed uniformly and then heated and cured at 130-200°C. The liquid silicone rubber provided by the invention adopts white carbon black treated with hexamethyldisilazane and silane coupling agent on the surface as a reinforcing filler, which can be well mixed with other components and changes the network structure of silicone rubber , the obtained liquid silicone rubber product has high tear resistance, which expands the application range of the liquid silicone rubber material, and is not easy to deteriorate after long-term storage, which improves the service life of the silicone rubber.

Description

A liquid silicone rubber

technical field

The invention relates to the field of silicone rubber, in particular to an addition-type high tear-resistant liquid silicone rubber.

Background technique

Addition type liquid high tear resistance silicone rubber (can be called LSR or LSE) is a kind of high-grade silicone rubber. First of all, compared with the condensation type silicone rubber, the addition type silicone rubber has the advantages of no by-products during the vulcanization process, extremely small shrinkage, and deep vulcanization, and the sealing performance at high temperatures is also better than the condensation type. Secondly, addition-type liquid silicone rubber has another outstanding advantage: simple process and low cost. This is due to the small molecular weight of liquid silicone rubber, low viscosity, convenient processing and molding, which can save the mixing, preforming, finishing and other processes, easy to realize automation, save energy and labor, short production cycle and high efficiency. Therefore, although the raw material price of addition-type liquid silicone rubber is slightly higher than that of ordinary silicone rubber, the total cost is lower than that of ordinary silicone rubber, especially when manufacturing small products. Moreover, in the preparation of insulators, cold-shrinkable tubes, wire and cable sheaths, etc., the addition-type liquid high-tear-resistant silicone rubber has a higher tear-resistant strength than ordinary liquid silicone rubber, effectively improving the service life of the product.

Contents of the invention

In order to further improve the tear resistance of the existing liquid silicone rubber, the object of the present invention is to provide an addition type high tear resistance liquid silicone rubber.

The liquid silicone rubber provided by the present invention is prepared by mixing the following components uniformly and then heating and curing at 130-200°C in parts by weight:

(i) 50-300 parts by weight of organopolysiloxane containing two or more aliphatic unsaturated groups;

(ii) 0.1 to 20 parts by weight of organopolysiloxane containing silicon-bonded hydrogen atoms;

(Ⅲ) 1 to 100 parts by weight of white carbon black;

(iv) 0.001 to 0.1 parts by weight of platinum catalyst;

(v) Alkyne-containing inhibitors, the content of which is 1-100 mol of alkynyl groups for each Pt atom in the platinum catalyst.

The white carbon black described in component (iii) can be precipitated white carbon black or fumed white carbon black or a mixture of the two, and the surface of the white carbon black filler is determined by the BET method, and the specific surface area of these white carbon blacks is at least 50m ² /g, preferably 50-500m ² /g, more preferably 200-400m ² /g.

When the silica is hydrophobic, it is easy to mix with component (i) and the viscosity does not increase too much during storage. Therefore, the white carbon black is preferably white carbon black treated with hexamethyldisilazane, and the amount of said hexamethyldisilazane is 10-50% of the weight of the white carbon black.

Si-NH-Si in (CH ₃ ) ₃ SiNHSi(CH ₃ ) ₃ can be hydrolyzed to form Si-OH under appropriate conditions, and then condense with -OH on the surface of silica, so that the liquid silicone rubber component can be improved. Compatibility of organic and inorganic materials.

In order to further improve the performance of silicone rubber, the white carbon black is also treated with a vinyl-containing silane coupling agent, and the amount of the vinyl-containing silane coupling agent is 0.1 to 15% of the weight of the white carbon black, preferably 1~10%.

The vinyl-containing silane coupling agent is selected from one or more of vinyltrimethoxysilane, vinyltriethoxysilane and tetramethyldivinyldisilazane.

The surface hydroxyl groups of silica are replaced by vinyl-containing silane coupling agents, vinyl and hydrogen-containing siloxanes are added, and vinyl-containing siloxanes can also be cross-linked with hydrogen-containing siloxanes, thereby making white Carbon black is not only a reinforcing filler, but also participates in the network structure of silicone rubber, so that the cured silicone rubber has better tear resistance.

The surface treatment method of white carbon black is: mix white carbon black with hexamethyldisilazane and/or vinyl-containing silane coupling agent, stir for 1-5 hours, it can be carried out at normal temperature and normal pressure, for To speed up the processing process, it can also be properly heated and pressurized.

Component (i) is a linear, cyclic or branched organopolysiloxane composed of structural units represented by the following formula, with a molar mass of 10 ² to 10 ⁵ g/mol:

R _a R ¹ _b SiO _(4-ab)/2

Wherein, R is a halogen, -CN, -SCN, -NCO or a C1-C18 substituted or unsubstituted hydrocarbon group;

R ¹ is a Si-C bonded C2-C10 substituted or unsubstituted alkenyl or alkyne group;

a is an integer of 0 to 3, b is an integer of 0 to 2, and a+b≦3.

Specifically, R can be the same or different, and the hydrocarbon groups include aliphatic hydrocarbon groups and aromatic hydrocarbon groups, and the aliphatic hydrocarbon groups can be methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl base, n-butyl, isobutyl, isopentyl, neopentyl, tert-pentyl, hexyl, heptyl, octyl, nonyl, decyl, etc.; the aromatic hydrocarbon group can be phenyl, benzyl, etc.; A preferred hydrocarbon group is a C1-C6 aliphatic hydrocarbon group or a phenyl group; more preferably a methyl group or a phenyl group.

R ¹ is preferably vinyl, propenyl, methallyl, 1-propenyl, ethynyl, butadienyl, hexadienyl, vinylphenyl or styryl and the like.

The organopolysiloxane of component (i) can be olefin-based polysiloxane with relatively low molecular weight, or highly polymerized polydimethylsiloxane with at least two silicon-bonded vinyl groups on the chain or at the end of the chain. Siloxane: The structure of oligomeric or highly polymerized siloxane can be linear, cyclic or branched, and can also be similar to dendritic or network structures. Linear or cyclic polysiloxane is mainly composed of structural units of formula R ₃ SiO _1/2 , R ₂ R ¹ SiO _1/2 , R ¹ RSiO _2/2 or R ₂ SiO _2/2 ; where R ¹ , R defined above. Branched or networked polysiloxanes also contain trifunctional or tetrafunctional units, such as structural units of the formula RSiO _3/2 , R ¹ SiO _3/2 or SiO _4/2 ; wherein R ¹ , R define As above. It is of course also possible to use any mixtures of different siloxanes which meet the stated criteria for component (i).

Component (i) is most preferably a polydiorganosiloxane having a linear polysiloxane viscosity of 1 mPa·s to 10 ⁵ mPa·s (at a temperature of 25°C).

Component (ii) is an organopolysiloxane composed of structural units represented by the following formula:

R _c H _d SiO _(4-cd)/2

Wherein, R is halogen, -CN, -SCN, -NCO, phenyl, benzyl, or a C1-C18 substituted or unsubstituted saturated hydrocarbon group;

c is an integer from 0 to 3, d is an integer from 0 to 2, and c+d≤3;

Each molecule contains an average of at least 3 silicon-bonded hydrogen atoms; its molar mass is 10 ² to 10 ⁵ g/mol;

The organopolysiloxane preferably contains 0.1 to 1.6% by weight of silicon-bonded hydrogen atoms.

The organopolysiloxane of the component (ii) can be a relatively low molecular weight SiH functional oligosiloxane, such as tetramethyldisiloxane; it can also have SiH groups on the chain or at the end of the chain The highly polymerized polydimethylsiloxane, of course, can also use any existing different silicone mixtures that can meet the performance standards after curing. The organopolysiloxane of component (ii) must be used in an amount such that the molar ratio of SiH groups to all aliphatic unsaturated groups in the silicone rubber component is between 1 and 10.

Component (ii) is most preferably an organopolysiloxane having a linear polysiloxane viscosity of 1 mPa·s to 10 ⁴ mPa·s (at a temperature of 25°C).

The platinum catalyst described in component (iv) is preferably a platinum compound that is compatible in the polyorganosiloxane, examples of soluble platinum compounds that can be used are platinum of the formula (PtCl.alkene) ₂ and H(PtCl.alkene) - olefin complexes. As the olefin, it is preferable to use an olefin having 2 to 8 carbon atoms, such as ethylene, propylene, butene, and octene, etc., and isomers thereof; or a cycloolefin having 5 to 7 carbon atoms. Examples include cyclopentene, cyclohexene and cycloheptene. Other soluble platinum catalysts are platinum-cyclopropane complexes of formula (PtCl ₂ C ₃ H ₆ ) ₂ ; reactants of hexachloroplatinic acid with alcohols, ethers, aldehydes and mixtures thereof; or hexachloroplatinum in ethanol solution Acid reacts with methylvinylcyclotetrasiloxane in the presence of sodium bicarbonate. Especially preferred are platinum complexes with vinylsiloxanes, such as 1,3-divinyl-1,1,3,3-tetramethyldisiloxane platinum complex or 1,3,5,7-tetra The complex of vinyl-1,3,5,7,-tetramethylcyclosiloxane has good compatibility in silicone rubber components, high hydrosilation reactivity, and good preservation stability.

Preferably, component (iv) is selected from 1,3-divinyl-1,1,3,3-tetramethyldisiloxane platinum complex, bis(alkynyl)(1,5-cyclooctadi ene) platinum complex, bis(alkynyl)(bicyclo[2.2.1]hepta-2,5-diene)platinum complex, bis(alkynyl)(1,5-dimethyl-1,5- cyclooctadiene) platinum complex or bis(alkynyl)(1,6-dimethyl-1,5-cyclooctadiene) platinum complex.

The amount of platinum catalyst used depends on factors such as crosslinking speed and economy and the use of each component. The amount of platinum catalyst per 100 parts by weight of curable organopolysiloxane is usually between 2 to 5000 ppm by weight ( ppm=one part by weight per million parts by weight).

The alkyne-containing inhibitor described in component (v) is used to control and adjust the processing time, initial temperature and crosslinking speed of the silicone rubber of the present invention. Commonly used inhibitors are acetylenic alcohol inhibitors such as 1-ethynyl-1-cyclohexanol, 2-methyl-3-butyn-2-ol or 3,5-dimethyl-1-hexyne- 3-alcohols; polymethylvinylcyclosiloxanes such as 1,3,5,7-tetravinyltetramethylcyclosiloxane; with methylvinyl SiO _2/2 groups and or _R vinyl SiO _1/2- terminated low molecular weight silicone oils such as divinyltetramethyldisiloxane, tetravinyldimethyldisiloxane; organic hydroperoxides such as cumene Peroxide; Organic peroxide; Organic sulfone; Organic amine; Amide; Phosphate; Eye; Diaziridine, etc.

Preferably, component (v) is selected from 1-ethynyl-1-cyclohexanol, 2-methyl-3-butyn-2-ol, 3,5-dimethyl-1-hexyn-3- alcohol or polymethylvinylcyclosiloxane.

The acetylenic alcohol inhibitor has the disadvantage of being volatile during use, especially during the mixing and defoaming process of the two components before use, because the acetylenic alcohol is volatile, and the surface with the crosslinking agent is vulcanized first, which will cause wrinkles and unevenness, which will affect the appearance . When it is used in a single component that requires long-term stability, due to the increase of the compounding amount, there are problems of poor compatibility with the rubber compound and poor vulcanization. The structure of the acetylenic alcohol inhibitor can be improved by introducing the siloxane group into the siloxane structure, or combining with other inhibitors, so as to improve its performance. The method can adopt any existing method in this field.

Based on the above considerations, the liquid silicone rubber provided by the present invention preferably consists of the following components in parts by weight:

(i) 100-300 parts by weight of organopolysiloxane containing two or more aliphatic unsaturated groups;

(ii) 1 to 10 parts by weight of organopolysiloxane containing silicon-bonded hydrogen atoms;

(iii) 10-100 parts by weight of white carbon black, with a specific surface area of 50-500m ² /g, preferably 200-400m ² /g;

(iv) 0.001 to 0.1 parts by weight of platinum catalyst;

(v) 0.01 to 0.1 parts by weight of an alkyne group-containing inhibitor.

Preferably, the process of heating and curing at 130-200°C after mixing uniformly in the present invention is: mixing components (i) and (iii) uniformly to obtain a base compound; taking 40-60% of the Add component (ⅳ) to the base rubber, stir well to prepare component (A) for later use; add components (ii) and (v) to the remaining base rubber, and stir evenly to prepare component (B) for later use ; Mix component (A) and component (B) evenly, heat and cure at 130-200°C.

Process steps such as mixing, stirring, and heating and curing in the above heating and curing process all adopt existing technologies in the art.

The liquid silicone rubber provided by the present invention adopts white carbon black, especially white carbon black whose surface is treated with hexamethyldisilazane and silane coupling agent as a reinforcing filler, which can be well mixed with other components , Changed the network structure of silicone rubber, the liquid silicone rubber product obtained has high tear strength, which can reach more than 30KN/m. The increase in tear strength can expand the application range of liquid silicone rubber materials. Moreover, the liquid silicone rubber product provided by the invention is not easy to deteriorate when stored for a long time, and the service life of the rubber is improved. In addition, the source of various additive ingredients is easy to obtain, the preparation method is simple and convenient, and has excellent industrial application prospect.

Detailed ways

The following examples are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

Example 1

Add 20wt% hexamethyldisilazane and 1.5wt% vinyltriethoxysilane to the white carbon black, stir and mix for 2-3 hours at normal temperature and pressure.

Add 200 parts by weight of α, ε-vinyl dimethyl polydimethylsiloxane (viscosity 10000mPa·s, 25°C) into the vacuum kneader, add 60 parts with 20wt% (calculated as white carbon black) six Methyldisilazane and 1.5wt% (calculated as white carbon black) vinyltriethoxysilane-treated white carbon black (specific surface area 300m ² /g) were mixed uniformly, heated to 150°C, heated and kneaded for 2 hours, The low molecular weight was removed by vacuum for 2 hours, and after cooling, it was ground by a three-roller machine and filtered to obtain a liquid silicone rubber base compound.

In 130 parts by weight of liquid silicone rubber base compound, add 0.01 part by weight of 1,3-divinyl-1,1,3,3-tetramethyldisiloxane platinum complex, stir evenly, remove air bubbles, and filter , to obtain component (A).

In 130 parts by weight of liquid silicone rubber base compound, add 2.0 parts by weight of polymethyl hydrogen siloxane (viscosity 50mPa s, 25°C, H%=0.8%) to react with 1-ethynyl-1-cyclohexanol Inhibitor 0.04 parts by weight, mixed uniformly at room temperature, degassed, filtered to obtain component (B).

Mix component (A) and component (B) uniformly according to the mass ratio of 1:1, inject into the mold, heat and cure at 160°C to form a liquid silicone rubber material, mold at 160°C for 10 minutes, and make a 6mm and 2mm thick film.

Example 2

Add 200 parts by weight of α, ε-vinyl dimethyl polydimethylsiloxane (viscosity 15000mPa·s, 25°C) into the vacuum kneader, add 70 parts with 20% (calculated as white carbon black) six Methyldisilazane and 2.5% (calculated as white carbon black) vinyltriethoxysilane-treated white carbon black (specific surface area 300m ² /g) (treatment method is the same as in Example 1) are mixed uniformly, and the temperature is raised to 150 ℃, heated and kneaded for 2 hours, delowed molecular weight by vacuum for 2 hours, cooled and ground by three-roll machine, and filtered. Finally, the liquid silicone rubber base compound is obtained.

In 135 parts by weight of liquid silicone rubber base compound, add 0.01 part by weight of 1,3-divinyl-1,1,3,3-tetramethyldisiloxane platinum complex, stir evenly, remove air bubbles, and filter , to obtain component (A).

In 135 parts by weight of liquid silicone rubber base compound, add 3.0 parts by weight of polymethylhydrogensiloxane (viscosity 50mPa s, 25°C, H%=0.9%) to react with 1-ethynyl-1-cyclohexanol Inhibitor 0.04 parts by mass, mixed uniformly at room temperature, degassed, and filtered to obtain component (B).

Mix component (A) and component (B) evenly according to the mass ratio of 1:1, inject into the mold, heat and cure at 170°C to form a liquid silicone rubber material, mold at 170°C for 10 minutes, and make a 6mm and 2mm thick film.

Example 3

Add 200 parts by weight of α, ε-vinyl dimethyl polydimethylsiloxane (viscosity 8000mPa·s, 25°C) into the vacuum kneader, add 70 parts with 20% (calculated as white carbon black) six Methyldisilazane and 3.0% (calculated as white carbon black) vinyltriethoxysilane-treated white carbon black (specific surface area 300m ² /g) (treatment method is the same as in Example 1) are mixed uniformly, and the temperature is raised to 150 ℃, heated and kneaded for 2 hours, delowed molecular weight by vacuum for 2 hours, cooled and ground by three-roll machine, and filtered. Finally, the liquid silicone rubber base compound is obtained.

In 130 parts by weight of liquid silicone rubber base compound, add 0.01 part by weight of 1,3-divinyl-1,1,3,3-tetramethyldisiloxane platinum complex, stir evenly, remove air bubbles, and filter , to obtain component (A).

In 140 parts by weight of liquid silicone rubber base compound, add 3.2 parts by weight of polymethylhydrogensiloxane (viscosity 50mPa s, 25°C, H%=1.0%) to react with 1-ethynyl-1-cyclohexanol Inhibitor 0.04 parts by weight, mixed uniformly at room temperature, degassed, and filtered to obtain component (B).

Mix component (A) and component (B) according to the mass ratio of 1:1, inject it into the mold, heat and cure at 190°C to form a liquid silicone rubber material, and mold it at 190°C for 10 minutes to make a 6mm and 2mm thick film.

Example 4

Add 200 parts by weight of α, ε-vinyl dimethyl polydimethylsiloxane (viscosity 10000mPa·s, 25°C) into the vacuum kneader, add 60 parts with 20wt% (calculated as white carbon black) six Methyldisilazane and 1.5wt% (calculated as white carbon black) vinyltriethoxysilane-treated white carbon black (specific surface area 300m ² /g) (treatment method is the same as in Example 1) are mixed uniformly, and the temperature is raised to Heating and kneading at 150°C for 2 hours, vacuum delowering for 2 hours, cooling, grinding with a three-roller machine, and filtering to obtain a liquid silicone rubber base compound.

In 120 parts by weight of liquid silicone rubber base compound, add 5 parts by weight of polysiloxane {its molecular structure is [(CH ₃ ) ₃ SiO _1/2 ] _m [(CH ₃ ) ₂ (CH ₂ =CH)SiO _1/2 ] _n [SiO _4/2 ] _z (where (m+n)/z=0.7, z=30) the vinyl content is 0.36%} add 1,3-divinyl-1,1,3, 0.01 parts by weight of 3-tetramethyldisiloxane platinum complex, stirred evenly, degassed, and filtered to obtain component (A).

In 140 parts by weight of liquid silicone rubber base compound, add 3.2 parts by weight of polymethylhydrogensiloxane (viscosity 50mPa s, 25°C, H%=1.0%), and 1-ethynyl-1-cyclohexanol 0.04 parts by weight of the reaction inhibitor, mixed uniformly at room temperature, degassed, and filtered to obtain component (B).

Mix component (A) and component (B) evenly according to the mass ratio of 1:1, inject into the mold, heat and cure at 170°C to form a liquid silicone rubber material, mold at 170°C for 10 minutes, and make a 6mm and 2mm thick film.

Example 5

Add 200 parts by weight of α, ε-vinyl dimethyl polydimethylsiloxane (viscosity 10000mPa·s, 25°C) into the vacuum kneader, add 60 parts with 20wt% (calculated as white carbon black) six Methyldisilazane and 1.5wt% (calculated as white carbon black) vinyltriethoxysilane-treated white carbon black (specific surface area 300m ² /g) (treatment method is the same as in Example 1) are mixed uniformly, and the temperature is raised to Heating and kneading at 150°C for 2 hours, vacuum delowering for 2 hours, cooling, grinding with a three-roller machine, and filtering to obtain a liquid silicone rubber base compound.

In 130 parts by weight of liquid silicone rubber base compound, add 3 parts by weight of polysiloxane {its molecular structure is [(CH ₃ ) ₃ SiO _1/2 ] _m [(CH ₃ ) ₂ (CH ₂ =CH)SiO _1/2 ] _n [SiO _4/2 ] _z (where (m+n)/z=0.7, z=30) the vinyl content is 0.36%} add 1,3-divinyl-1,1,3, 0.01 parts by weight of 3-tetramethyldisiloxane platinum complex, stirred evenly, degassed, and filtered to obtain component (A).

In 130 parts by weight of liquid silicone rubber base compound, add 3.0g polysiloxane {its molecular structure is [(CH ₃ ) ₂ HSiO _1/2 ] _m [SiO _4/2 ] _z , where m/z= 1.8, z=35) H% is 0.99%} parts by weight, and 0.04 parts by weight of 1-ethynyl-1-cyclohexanol reaction inhibitor, mix uniformly at room temperature, degassing, and filter to obtain the component ( B).

Mix component (A) and component (B) evenly according to the mass ratio of 1:1, inject into the mold, heat and cure at 170°C to form a liquid silicone rubber material, mold at 170°C for 10 minutes, and make a 6mm and 2mm thick film.

The 6mm thick film in Examples 1-5 was used to test the hardness test (standard GB/T531.1-2008), and the 2mm thick film was used to measure the physical and mechanical properties. The experimental results are shown in Table 1.

Table 1 physical and mechanical properties test results

Although the present invention has been described in detail with general descriptions and specific embodiments above, it is obvious to those skilled in the art that some modifications or improvements can be made on the basis of the present invention. Therefore, the modifications or improvements made on the basis of not departing from the spirit of the present invention all belong to the protection scope of the present invention.

Claims (10)

1. a liquid silastic is characterized in that, under 130～200 ℃, being heating and curing after being mixed by following component by weight makes:

(ⅰ) contain organopolysiloxane 50～300 weight parts of two or more unsaturated group of aliphatic series;

(ⅱ) contain organopolysiloxane 0.1～20 weight part of silicon keyed jointing Wasserstoffatoms;

(ⅲ) WHITE CARBON BLACK 1～100 weight part;

(ⅳ) platinum catalyst 0.001～0.1 weight part;

(ⅴ) contain the alkynyl suppressor factor, its content is the alkynyl group that each Pt atom pairs is answered 1～100mol in the said platinum catalyst.

2. liquid silastic according to claim 1 is characterized in that, component (ⅲ) is for carrying out the WHITE CARBON BLACK after the surface treatment with hexamethyldisilazane, and the consumption of said hexamethyldisilazane is 10～50% of a WHITE CARBON BLACK weight.

3. liquid silastic according to claim 2 is characterized in that, said WHITE CARBON BLACK also adopts the silane coupling agent that contains vinyl to carry out surface treatment, and the said dosage of silane coupling agent that contains vinyl is 1～10% of a WHITE CARBON BLACK weight.

4. liquid silastic according to claim 3 is characterized in that, the said silane coupling agent that contains vinyl is selected from one or more in vinyltrimethoxy silane, vinyltriethoxysilane, the tetramethyl divinyl disilazane.

5. liquid silastic according to claim 1 is characterized in that, component (ⅰ) is the organopolysiloxane of linearity, ring-type or collateralization that structural unit constituted shown in the following formula, and its molar mass is 10 ²～10 ⁵G/mol:

R _aR ¹ _bSiO _(4-a-b)/2

Wherein, R be halogen ,-CN ,-SCN ,-replacement or the non-substituted hydrocarbon radical of NCO or C1～C18;

R ¹Replacement or non-substituted olefine base or alkynes base for the C2～C10 of Si-C keyed jointing;

A is that 0～3 integer, b are 0～2 integer, and a+b≤3.

6. liquid silastic according to claim 1 is characterized in that, component (ⅱ) is the organopolysiloxane that structural unit shown in the following formula constitutes:

R _cH _dSiO _(4-c-d)/2

Wherein, R be halogen ,-CN ,-SCN ,-replacement or the non-replacement saturated hydrocarbyl of NCO, phenyl, benzyl or C1～C18;

C is 0～3 integer, and d is 0～2 integer, and c+d≤3;

On average contain 3 silicon keyed jointing Wasserstoffatomss in each molecule at least; Its molar mass is 10 ²～10 ⁵G/mol;

Described organopolysiloxane preferably contains the silicon keyed jointing Wasserstoffatoms of 0.1～1.6 weight %.

7. liquid silastic according to claim 1 is characterized in that, component (ⅳ) is selected from 1,3-divinyl-1; 1,3,3-tetramethyl disiloxane platinum complex, two (alkynyls) (1; The 5-cyclooctadiene) platinum complex, two (alkynyl) (two ring [2.2.1] heptan-2,5-diene) platinum complex, two (alkynyl) (1,5-dimethyl--1; The 5-cyclooctadiene) platinum complex or two (alkynyl) (1,6-dimethyl--1,5-cyclooctadiene) platinum complex.

8. liquid silastic according to claim 1 is characterized in that, component (ⅴ) is selected from 1-ethynyl-1-hexalin, 2-methyl-3-butyne-2-alcohol, 3,5-dimethyl--1-hexin-3-alcohol or gather the methyl ethylene cyclosiloxane.

9. according to each described liquid silastic of claim 1-8, it is characterized in that under 130～200 ℃, being heating and curing after said liquid silastic is mixed by following component by weight makes:

(ⅰ) contain organopolysiloxane 100～300 weight parts of two or more unsaturated group of aliphatic series;

(ⅱ) contain organopolysiloxane 1～10 weight part of silicon keyed jointing Wasserstoffatoms;

(ⅲ) WHITE CARBON BLACK 10～100 weight parts, its specific surface area is 50～500m ²/ g is preferably 200～400m ²/ g;

(ⅳ) platinum catalyst 0.001～0.1 weight part;

(ⅴ) contain alkynyl suppressor factor 0.01～0.1 weight part.

10. according to each described liquid silastic of claim 1-9, it is characterized in that the said process that under 130～200 ℃, is heating and curing of back that mixes is: with component (ⅰ) and (ⅲ) mix and obtain sizing; Get mass percent and be in 30～70% the said sizing and add component (ⅳ), stirring, it is subsequent use to make component (A); Add component (ⅱ) and (ⅴ) in the sizing in residue, it is subsequent use for making component (B) to stir; Component (A) and component (B) are mixed, and under 130～200 ℃, being heating and curing promptly gets.