JP5605925B2 - Organopolysilmethylene and organopolysilmethylene composition - Google Patents

Description

  The present invention relates to an addition-curing organopolysilmethylene having excellent heat resistance, mechanical strength, electrical insulation, electrical properties, and water resistance, a composition comprising the organopolysilmethylene, and a cured product thereof.

  Conventionally, curable silicone rubber compositions that cure to become silicone rubber elastic bodies are well known, and gasket materials for electrical and electronic parts utilizing its excellent properties such as weather resistance, heat resistance, and electrical insulation, It is widely used as molding materials such as potting materials, coating materials and molding materials, wire coating materials, and automobile parts. However, since the curable silicone rubber composition has a siloxane bond peculiar to silicone, its ionic bond makes it resistant to chemicals such as acid resistance and alkali resistance, water resistance, gas permeability, and use under high temperature humidification. In extremely severe usage environments, the excellent properties of silicone cannot be demonstrated.

As countermeasures, a polymer in which part of the siloxane bond is a silethylene bond (Patent Document 1) and a polymer in which a silphenylene bond is bonded (Patent Document 2) are known. However, these polymers have problems such as being difficult to synthesize and poor in mass productivity, and expensive polymers, and are not commercialized except for special uses or special fields.

A polydiarylsilmethylene composed of a silmethylene bond is known as a precursor of silicon carbide ceramics (Patent Documents 3 to 5). This polymer is a crystalline thermoplastic silicon-based polymer having a high melting point, and is excellent in heat resistance, insulation, electrical properties, chemical resistance, and water resistance, but is not practically used due to poor molding processability. Various attempts have been made to improve the moldability, and a mixture of polydiarylsilmethylene and silicone polymer (Patent Document 6) and a mixture of polydiarylsilmethylene and polyalkylsilmethylene (Patent Documents 7 to 8) have been reported. Yes. In addition, a method of forming a polydiarylsilmethylene on a substrate by ring-opening polymerization of a disilacyclobutane film with a metal fine particle film is known (Patent Document 9). However, since the diaryl silmethylene polymer is a highly crystalline thermoplastic polymer, it is difficult to synthesize and is expensive and has poor processability. For this reason, the use of silicon carbide ceramics as a precursor has been studied, but there is no thermosetting composition that takes advantage of the characteristics of a polymer.

No. 01/030887 JP-A-5-320350 JP-A-8-109264 JP-A-8-109265 JP-A-8-109266 Japanese Patent Laid-Open No. 9-227781 Japanese Patent Laid-Open No. 9-227782 Japanese Patent Laid-Open No. 9-227783 Japanese Patent No. 3069655

  An object of the present invention is to provide an addition-curing organopolysilmethylene comprising a silicon-based polymer having a silmethylene bond, and to contain the addition-curing organopolysilmethylene, and when cured, heat resistance, electrical insulation properties, An object of the present invention is to provide an organopolysilmethylene composition that is excellent in water resistance and moldability and gives a cured product with little gas permeability, and a cured product thereof.

  As a result of intensive studies to achieve the above object, the present inventor succeeded in synthesizing an organopolysilmethylene having at least two alkenyl groups, which are addition reaction groups bonded to a silicon atom, in one molecule, and It comprises an organopolysilmethylene, a crosslinking agent having at least two hydrogen atoms bonded to silicon atoms, selected from organohydrogenpolysilmethylene or organohydrogenpolysiloxane, and a platinum group metal catalyst. It has been found that an addition-curable organopolysilmethylene composition gives a cured product having excellent properties.

（式中、Ｒ^１は互いに独立に、非置換または置換の炭素原子数１〜１０の１価炭化水素基、アルコキシ基、水酸基、（Ｒ）_３ＳｉＣＨ_２−、または（Ｒ）_３ＳｉＯ−より選ばれる基であり、Ｒ ^１ の少なくとも２つはアルケニル基であり、前記式中Ｒは、互いに独立に、非置換または置換の炭素原子数１〜１０の１価炭化水素基、アルコキシ基、または水酸基より選ばれる基であり、ｍは１〜１００、ｎは１〜１００の整数である。）で表され、ケイ素原子に結合したアルケニル基を１分子中に少なくとも２個有するオルガノポリシルメチレンシロキサン（本明細書中においてオルガノポリシルメチレンともいう）を提供する。 That is, the present invention provides the following general formula (1):

(In the formula, R ¹ is independently of each other an unsubstituted or substituted monovalent hydrocarbon group having 1 to 10 carbon atoms, an alkoxy group, a hydroxyl group, (R) ₃ SiCH ₂ —, or (R) ₃ SiO—). At least two of R ¹ are alkenyl groups, and in the above formulas, R are independently of each other an unsubstituted or substituted monovalent hydrocarbon group having 1 to 10 carbon atoms, an alkoxy group, or And an organopolysilmethylenesiloxane having at least two alkenyl groups bonded to a silicon atom in one molecule, wherein m is a group selected from hydroxyl groups, m is 1 to 100, and n is an integer of 1 to 100. (Also referred to herein as organopolysilmethylene).

The present invention also provides
The following average composition formula (2):
[Chemical 2]
R ⁴ _e Cl _f Si (CH ₂ ) _{(4-ef) / 2} (2)
(R ⁴ is a group independently selected from an unsubstituted or substituted monovalent hydrocarbon group having 1 to 10 carbon atoms, and e and f are numbers satisfying e + f = 1.5 to 2.8. Yes, provided that the organopolysilmethylene represented by 0.001 ≦ f / (e + f) ≦ 0.9) and the following general formula (3):
[Chemical 3]
R ⁵ _g R ⁶ _h SiCl _{4- (g + h)} (3)
(R ⁵ is independently selected from an unsubstituted or substituted monovalent hydrocarbon group having 1 to 10 carbon atoms, R ⁶ is an alkenyl group having 2 to 10 carbon atoms, and g is 0 to 2, h is an integer of 1 to 3, where g + h is 1 to 3.) A method for producing an organopolysilmethylene of the above general formula (1) by reaction with an alkenyl group-containing silane represented by formula (1). provide.

Furthermore, the present invention provides
(A) Organopolysilmethylene of the above general formula (1),
(C) The above-mentioned (A) organopolysilmethylene as a crosslinking agent selected from organohydrogenpolysilmethylene or organohydrogenpolysiloxane having two or more hydrogen atoms (SiH groups) bonded to silicon atoms in one molecule An organopolysil containing an amount of SiH groups in the cross-linking agent in an amount of 0.1 to 5.0 mol and a catalyst amount of (D) a platinum group metal catalyst per mol of alkenyl groups of A methylene composition and a cured product thereof are provided.

  The composition containing the organopolysilmethylene of the present invention has excellent heat resistance, electrical insulation, mechanical strength, and optical properties, and has the gas permeability and severe use conditions which are disadvantages of silicone rubber. Provided is a cured product having excellent properties such as water resistance and hydrolysis resistance. Moreover, since the composition containing the organopolysilmethylene of the present invention has molding processability similar to that of conventional silicone rubber, a conventional processing machine such as a molding apparatus can be used as it is. The molded product obtained from the organopolysilmethylene composition of the present invention can be suitably used for electrical and electronic parts such as insulating materials, sealing materials, cables, packings, connectors, etc., automotive parts, semiconductor devices and the like, similar to silicone rubber. It is done. In addition, it is used for applications such as lenses and transparent sealing materials by taking advantage of its optical characteristics.

FIG. 1 is an NMR of the compound prepared in Example 1.

Hereinafter, the present invention will be described in detail.

式中、ｍは１〜１００、好ましくは１〜５０の整数であり、ｎは１〜１００、好ましくは１〜５０、さらに好ましくは1〜２０の整数である。 (A) The organopolysilmethylene (A) component is an organopolysilmethylene represented by the following general formula (1) and having at least two alkenyl groups bonded to silicon atoms in one molecule.

In formula, m is an integer of 1-100, Preferably it is 1-50, n is 1-100, Preferably it is 1-50, More preferably, it is an integer of 1-20.

In the formula, R ¹ is independently selected from an unsubstituted or substituted monovalent hydrocarbon group having 1 to 10 carbon atoms, an alkoxy group, a hydroxyl group, (R) ₃ SiCH ₂ —, and (R) ₃ SiO—. R is a group independently selected from an unsubstituted or substituted monovalent hydrocarbon group having 1 to 10 carbon atoms, an alkoxy group, or a hydroxyl group. Examples of the monovalent hydrocarbon group include alkyl groups such as methyl group, ethyl group, propyl group, isopropyl group and butyl group; cycloalkyl groups such as cyclohexyl group; vinyl group, allyl group, 1-propenyl group and 1-butenyl. An alkenyl group such as a 1-hexenyl group or a cyclohexenyl group; an aryl group such as a phenyl group or a tolyl group; an aralkyl group such as a benzyl group or a 2-phenylethyl group; and a carbon atom of these groups For example, a chloromethyl group, a 3-chloropropyl group, a 3,3,3-trifluoropropyl group, and a 2-cyanoethyl group may be mentioned in which some or all of the hydrogen atoms are substituted with a halogen atom, a cyano group, or the like. At least 2 of R ¹ is an alkenyl group such as a vinyl group or an allyl group, and among them, a vinyl group is preferable from the viewpoint of ease of synthesis and heat resistance. As R ¹ other than the alkenyl group, a methyl group and a phenyl group are preferable. In particular, a methyl group is preferable from the viewpoint of the curing characteristics of the composition and the flexibility of the cured product, and 50% or more of R ¹ is preferably a methyl group.

  The organopolysilmethylene represented by the above formula (1) is produced by reacting the organopolysilmethylene represented by the following average composition formula (2) with the alkenyl group-containing silane represented by the following formula (3). can do.

[Chemical 5]
R ⁴ _e Cl _f Si (CH ₂ ) _{(4-ef) / 2} (2)
Wherein R ⁴ is a group independently selected from an unsubstituted or substituted monovalent hydrocarbon group having 1 to 10 carbon atoms, and e and f are e + f = 1.5 to 2.8. , Preferably 1.8 to 2.5, more preferably 1.95 to 2.05, provided that 0.001 ≦ f / (e + f) ≦ 0.9, preferably 0.005 ≦ f. /(E+f)≦0.5, more preferably 0.005 ≦ f / (e + f) ≦ 0.1.)

[Chemical 6]
R ⁵ _g R ⁶ _h SiCl _{4- (g + h)} (3)
(R ⁵ is independently selected from an unsubstituted or substituted monovalent hydrocarbon group having 1 to 10 carbon atoms, R ⁶ is an alkenyl group having 2 to 10 carbon atoms, and g is 0 to 0. 2, h is an integer of 1 to 3, where g + h is 1 to 3)

R ⁴ and R ⁵ are, for example, an alkyl group such as a methyl group, an ethyl group, a propyl group, an isopropyl group, or a butyl group; a cycloalkyl group such as a cyclohexyl group; an aryl group such as a phenyl group or a tolyl group; a benzyl group, 2- An aralkyl group such as a phenylethyl group; and a part or all of hydrogen atoms bonded to carbon atoms of these groups are substituted with a halogen atom, a cyano group, or the like, for example, a chloromethyl group, a 3-chloropropyl group, Examples include 3,3,3-trifluoropropyl group and 2-cyanoethyl group. R ⁶ is an alkenyl group such as a vinyl group, an allyl group, a 1-propenyl group, a 1-butenyl group, a 1-hexenyl group, or a cyclohexenyl group. Examples of the alkenyl group-containing silane represented by the formula (3) include dimethylvinylmonochlorosilane, methyldivinylmonochlorosilane, trivinylmonochlorosilane, methylphenylvinylmonochlorosilane, methylvinyldichlorosilane, phenylvinyldichlorosilane, vinyltrichlorosilane, and the like. Is exemplified.

The organopolysilmethylene of the present invention is a method of synthesizing the organopolysilmethylene of the above average composition formula (2) and the alkenyl group-containing silane of the formula (3) by synthesizing, and the organopolysilmethylene of the average composition formula (2). The polysilmethylene is hydrolyzed to introduce a hydroxyl group bonded to a silicon atom, and then synthesized by a dehydrochlorination reaction with a silane of the general formula (3). Further, together with silanes of the general formula (3) can be used in combination of silane that does not contain an alkenyl group ^{_{(R 5 g SiCl 4-g}} ).

（式中、Ｖｉはビニル、Ｍｅはメチルを意味する。ｎは１〜１００、好ましくは１〜５０、さらに好ましくは1〜２０の整数。） The organopolysilmethylene of the present invention has, for example, the following structure.

(In the formula, Vi means vinyl and Me means methyl. N is an integer of 1 to 100, preferably 1 to 50, more preferably 1 to 20.)

  The present invention also provides (A) an organopolysilmethylene of the above general formula (1), (C) an organohydrogenpolysilmethylene having two or more hydrogen atoms (SiH groups) bonded to a silicon atom in one molecule, or An organopolysilmethylene composition comprising a crosslinking agent selected from organohydrogenpolysiloxanes and (D) a platinum group metal catalyst. The organopolysilmethylene composition of the present invention is represented by the following general formula (4), and may further contain (B) an organopolysiloxane having at least two alkenyl groups bonded to silicon atoms in one molecule. Good.

The (B) organopolysiloxane (B) component is an optional component that replaces part of the main component (A) organopolysilmethylene, and is represented by the following general formula (4), and is an alkenyl group bonded to a silicon atom. Is an organopolysiloxane having at least two per molecule.
[Chemical 8]
R ² _b SiO _{(4-b) / 2} (4)
(In the formula, R ² independently of each other is an unsubstituted or substituted monovalent hydrocarbon group having 1 to 10 carbon atoms, an alkoxy group, a hydroxyl group, or a group selected from (R) ₃ SiO—). At least two of the hydrocarbon groups are alkenyl groups, and R in the above formula is independently selected from an unsubstituted or substituted monovalent hydrocarbon group having 1 to 10 carbon atoms, an alkoxy group, or a hydroxyl group. And b is a number of 1.5 to 2.8, preferably 1.8 to 2.5, more preferably 1.95 to 2.05.)

Examples of the monovalent hydrocarbon group include an alkyl group such as a methyl group, an ethyl group, a propyl group, an isopropyl group, and a butyl group; a cycloalkyl group such as a cyclohexyl group; an alkenyl group such as a vinyl group and an allyl group; a phenyl group; Aryl groups such as tolyl groups; aralkyl groups such as benzyl groups and 2-phenylethyl groups; and some or all of hydrogen atoms bonded to carbon atoms of these groups are substituted with halogen atoms, cyano groups, For example, chloromethyl group, 3-chloropropyl group, 3,3,3-trifluoropropyl group, 2-cyanoethyl group and the like can be mentioned. At least 2 of R ² is an alkenyl group such as vinyl group, allyl group, 1-propenyl group, 1-butenyl group, 1-hexenyl group, cyclohexenyl group and the like. Is preferred. R ² other than an alkenyl group is preferably a methyl group or a phenyl group. In particular, the methyl group is excellent in compatibility with the component (A) and is preferable from the viewpoint of the curing characteristics of the composition and the flexibility of the cured product, and 50% or more of R ² is preferably a methyl group. Further, the heat resistance, it is preferable that part in view of the optical properties of the R ² is a phenyl group.

（式中、ｍは０〜３００、好ましくは１０〜２００、さらに好ましくは５０〜１５０、ｐ＋ｑは１〜３００、好ましくは１０〜２００、さらに好ましくは５０〜１５０の整数である。） Examples of such organopolysiloxanes include both-end vinyl group polydimethylsiloxane, both-end vinyl group polydimethylsiloxane-methylphenylsiloxane copolymer, and both-end vinyl group polydimethylsiloxane-diphenylsiloxane copolymer as shown in the following formula. Polymers are preferred.

(In the formula, m is 0 to 300, preferably 10 to 200, more preferably 50 to 150, and p + q is an integer of 1 to 300, preferably 10 to 200, more preferably 50 to 150.)

The organopolysilmethylene composition of the present invention comprises (A) component 1-100 parts by weight, (B) component 0-99 parts by weight, preferably (A) component 30-100 parts by weight, and (B) component 0-70. Containing parts by weight (total 100 parts by weight of component (A) and component (B)). When the component (A) is less than the lower limit, the characteristics of organopolysilmethylene such as water resistance and optical properties are not exhibited.

(C) Cross-linking agent (C) The cross-linking agent undergoes an addition reaction with (A) component organopolysilmethylene and (B) component organopoly to form a cross-linking bond to give a rubber elastic body having a three-dimensional network structure. The crosslinking agent of the present invention is selected from organohydrogenpolysylmethylene or organohydrogenpolysiloxane having two or more hydrogen atoms bonded to silicon atoms (hereinafter referred to as SiH groups) in one molecule.

The crosslinking agent of the present invention contains at least 2, preferably 3 or more SiH groups in one molecule. The molecular structure of the crosslinking agent is not particularly limited, and may be any of linear, cyclic, branched, three-dimensional network (resin-like), for example. As such a crosslinking agent, organohydrogenpolysilmethylene or organohydrogenpolysiloxane having 2 to 200 silicon atoms in one molecule, preferably 3 to 100, and being liquid at 25 ° C. is preferable. . In particular, an organohydrogenpolysiloxane that is easy to synthesize and has a selectable molecular structure is preferable.

In particular, an organohydrogenpolysiloxane represented by the following average composition formula (5) is preferable.
[Chemical Formula 10]
R ³ _c H _d SiO _{(4-cd) / 2} (5)
(R ³ is independently of each other an unsubstituted or substituted monovalent hydrocarbon group having 1 to 10 carbon atoms, a hydrogen atom, an alkoxy group, a group selected from a hydroxyl group, and c and d are 0.7 ≦ c ≦ 2.1, 0.001 ≦ d ≦ 1.0, and 0.8 ≦ c + d ≦ 3.0, preferably 1.0 ≦ c ≦ 2.0, 0.01 ≦ d ≦ 1.0, and 1. (The number satisfies 5 ≦ c + d ≦ 2.5.)
Of these, organohydrogenpolysiloxanes having 2 to 200 repeating siloxane units are preferred.

Examples of the organohydrogenpolysiloxane represented by the above average composition formula (5) include 1,1,3,3-tetramethyldisiloxane, 1,3,5,7-tetramethylcyclotetrasiloxane, tris (hydrogen Dimethylsiloxy) methylsilane, tris (hydrogendimethylsiloxy) phenylsilane, methylhydrogencyclopolysiloxane, methylhydrogensiloxane / dimethylsiloxane cyclic copolymer, trimethylsiloxy group-blocked methylhydrogenpolysiloxane, trimethylsiloxy at both ends Group-blocked dimethylsiloxane / methylhydrogensiloxane copolymer, both ends dimethylhydrogensiloxy group-blocked dimethylpolysiloxane, both ends dimethylhydrogensiloxy group-blocked dimethylsiloxa・ Methyl hydrogen siloxane copolymer, both ends trimethylsiloxy group-blocked methyl hydrogen siloxane ・ Diphenyl siloxane copolymer, both ends trimethyl siloxy group-blocked methyl hydrogen siloxane ・ Diphenyl siloxane ・ dimethyl siloxane copolymer, both ends trimethylsiloxy Blocked methylhydrogensiloxane / methylphenylsiloxane / dimethylsiloxane copolymer, both ends dimethylhydrogensiloxy group-blocked methylhydrogensiloxane / dimethylsiloxane / diphenylsiloxane copolymer, both ends dimethylhydrogensiloxy group-blocked methylhydrogen dimethylsiloxane-methylphenylsiloxane _{copolymer, (CH} 3) 2 _{HSiO 1/2} units, _{(CH 3) 3} iO copolymer _1/2 units · _{SiO 4/2 units, (CH} 3) a copolymer of 2 _{HSiO 1/2} units · _{SiO 4/2 units, (CH} 3) 2 _{HSiO 1/2} units · SiO _{4 / 2} unit. (C ₆ H ₅ ) ₃ SiO _1/2 unit copolymer and the like.

The amount of SiH groups in component (C) is 0.1 per mole of alkenyl groups in component (A) or per mole of alkenyl groups in components (A) and (B). It is good to mix | blend in the quantity used as -5.0 mol, Preferably it is 0.5-4.0 mol, More preferably, it is 0.8-3.0 mol. If it is less than the said lower limit, the crosslinked density of the hardened | cured material obtained from the composition of this invention will become low too much, and mechanical strength will run short. Moreover, since it has a bad influence on heat resistance, it is not preferable. Above the upper limit, foaming due to dehydrogenation occurs in the cured product. In addition, since changes in physical properties over time due to residual SiH groups may be manifested, the heat resistance of the cured product is further adversely affected, which is not preferable. In addition, with respect to the alkenyl group derived from the component (A) and the component (B) present in the composition, the alkenyl group derived from the component (A) is present in an amount of 50 to 100 mol%, preferably 80 to 100 mol%. It is good.

(D) Platinum group metal catalyst
(D) The platinum group metal catalyst is a catalyst for promoting the addition reaction (hydrosilylation) of the component (A) and the component (B) with the component (C). As such a catalyst, a known platinum group metal catalyst can be used, and it is preferable to use platinum or a platinum compound. Such platinum group metal catalysts include platinum black, platinous chloride, chloroplatinic acid, chloroplatinic acid-modified products, and complexes of chloroplatinic acid with olefins, aldehydes, vinyl siloxanes or acetylene alcohols. Can be mentioned.

  The compounding amount of the platinum group metal catalyst is an effective amount as a catalyst and is not particularly limited as long as it is appropriately increased or decreased depending on the desired curing rate. However, the component (A) or the component (A) and the component (B) ) The total amount of the components is preferably in the range of 0.1 to 1,000 ppm, more preferably 1 to 200 ppm on a mass basis in terms of the mass of the platinum group metal in terms of 100 parts by weight.

Other compounding components In addition to the above components (A) to (D), the organopolysilmethylene composition of the present invention includes a reinforcing filler, a heat stabilizer, and the like within a range not to impair the purpose and effect of the present invention. You may mix | blend various functional additives, such as antioxidant, a ultraviolet absorber, a light stabilizer, electroconductivity imparting agent, adhesiveness imparting agent, a coloring agent, a lubricant, a plasticizer, an antistatic agent, and a flame retardant. For example, reinforcing fillers such as fumed silica and precipitated silica, diatomaceous earth, graphite, aluminum oxide, mica, clay, carbon, titanium oxide, fillers such as glass beads, conductive materials, pigments, lubricants, mold release Polydimethylsiloxane as an agent can be added.

  The organopolysilmethylene composition of the present invention can be obtained by mixing the above components with a planetary mixer, Shinagawa mixer or the like according to a conventional method. The curing conditions of the organopolysilmethylene composition of the present invention may be the same as those of a known addition reaction curable silicone rubber composition, for example, it is sufficiently cured at room temperature, but may be heated as necessary. It can be cured by heating at 60 to 150 ° C., particularly 80 to 120 ° C., for 5 to 120 minutes, particularly 10 to 60 minutes.

  The organopolysilmethylene composition of the present invention is excellent in mechanical properties, heat resistance, electrical insulation, water resistance, gas permeability, optical properties, and particularly requires LED lenses and LED sealing materials that require transparency. It is the most suitable material for optical materials.

  EXAMPLES Hereinafter, although an Example and a comparative example are shown and this invention is demonstrated in detail, this invention is not restrict | limited to the following Example. In the following, “part” means part by mass, Me means methyl group, and Vi means vinyl group.

[Example 1]
(A1) Synthesis of alkenyl group-containing organopolysilmethylene 1540 g (4.64 mol, 90 mol%) of chloro group-containing silmethylene of the following formula (6) and 54.2 g (0.45) of dimethylvinylmonochlorosilane of the following formula (7) Mol, 10 mol%) was dissolved in 1000 g of xylene, and dropped at 60 ° C. into a mixed solvent system of 600 g of water and 300 g of xylene to cause a hydrolysis reaction. Subsequently, after aging reaction for 3 hours at room temperature, waste acid separation, washing with water, and azeotropic dehydration at 140 ° C. were performed.

0.2 g of KOH was added to this alkenyl group-introduced polysilmethylene and reacted at 140 ° C. for 10 hours for alkali polymerization, then neutralized and filtered, and then stripped at 160 ° C./5 mmHg for 30 minutes. As a result of analysis by 1H-NMR, it was found to be an alkenyl group-containing organopolysilmethylene (A1) having a structure represented by the following formula (8). The measurement result of NMR is shown in FIG. (NMR: JEOL JNM-LA300WB, 300 MHz, 1H-NMR)

[Example 2]
(A2) Synthesis of alkenyl group-containing organopolysilmethylene 260.3 g (0.335 mol, 67 mol%) of chloro group-containing silmethylene of the following formula (9) and 19.9 g (0 of dimethylvinylmonochlorosilane of the above formula (7)) .165 mol, 33 mol%) was dissolved in 200 g of xylene in the same manner as in Example 1, and dropped into a mixed solvent system of 200 g of water and 100 g of xylene at 60 ° C. to cause a hydrolysis reaction. Subsequently, aging reaction was performed at room temperature for 5 hours. Then, waste acid separation, washing with water, and azeotropic dehydration at 140 ° C were performed. To this alkenyl group-introduced polysilmethylene, 0.2 g of KOH was added, reacted at 140 ° C. for 10 hours for alkali polymerization, then neutralized and filtered, then stripped at 160 ° C./5 mmHg for 30 minutes to obtain the following formula (10 ) -Containing alkenyl group-containing organopolysilmethylene (A2).

[Example 3]
100 g of alkenyl group-containing organopolysilmethylene (A1) prepared in Example 1 is 34.7 g of SiH group-containing polysiloxane (C1) represented by the following formula (11) (Si—H / Si—Vi = 0.36). As a platinum catalyst, 0.1 g (20 ppm in terms of platinum metal) of a chloroplatinic acid alcohol solution (D1) having a platinum content of 2% by weight as a platinum catalyst was added and mixed. It was poured into a (mm) mold, placed in a desiccator, defoamed under reduced pressure (10 Torr) for 10 minutes, and then cured by heating at 150 ° C. for 1 hour to form a cured organopolysilmethylene. The physical properties are shown in Table 1.

[Example 4]
To 100 g of the alkenyl group-containing organopolysilmethylene (A2) prepared in Example 2, 25.7 g of SiH group-containing polysiloxane (C1) of the above formula (11) (Si—H / Si—Vi = 3), platinum catalyst (D1) 0.1 g (platinum metal conversion amount 20 ppm) was added and mixed, and heat cured at 150 ° C. for 1 hour in the same manner as in Example 1 to form a cured organopolysilmethylene. The physical properties are shown in Table 1.

[Example 5]
70 g of the alkenyl group-containing organopolysilmethylene (A2) prepared in Example 2 was added to 30 g of both terminal vinyl group-containing dimethylpolysiloxane / diphenylpolysiloxane copolymer (B1) represented by the following formula (12), containing SiH groups Polysiloxane (C1) 20.1 g (Si—H / Si—Vi = 3) and platinum catalyst (D1) 0.1 g (platinum metal equivalent 20 ppm) were added and mixed. And cured for 1 hour to form a cured organopolysilmethylene-organopolysiloxane. The physical properties are shown in Table 1.

[Comparative example]
100 g of a vinyl group-containing dimethylpolysiloxane / diphenylpolysiloxane copolymer (B1) represented by the above formula (12), 7 g of SiH group-containing polysiloxane (C1) (Si—H / Si—Vi = 3), Platinum catalyst (D1) 0.1 g (platinum metal conversion amount 20 ppm) was added and mixed, and the mixture was heated and cured at 150 ° C. for 1 hour in the same manner as in Example 1 to form a cured organopolysiloxane. The physical properties are shown in Table 1.

The physical properties of each cured product were evaluated by the following methods. The results are shown in Table 1.
(1) As for the appearance, the appearance of the cured product was visually observed, and the presence / absence of discoloration and transparency were visually evaluated.
(2) Hardness was measured with a JIS K6253 compliant type A durometer.
(3) Tensile strength, elongation, density, volume resistivity, dielectric breakdown strength, relative dielectric constant, and dielectric loss tangent were measured according to JIS K6249.
(4) Water vapor permeability was measured according to JIS Z0208.

  From Table 1, the cured products of Examples 3 to 5 have transparency, excellent mechanical strength, and low water vapor permeability. The cured product of the comparative example has poor mechanical strength and high water vapor permeability.

  The organopolysilmethylene composition of the present invention is excellent in mechanical properties, heat resistance, electrical insulation, water resistance, gas permeability, optical properties, and particularly requires LED lenses and LED sealing materials that require transparency. It is the most suitable material for optical materials.

Claims (2)

The following general formula (1):

(In the formula, R ¹ is independently of each other an unsubstituted or substituted monovalent hydrocarbon group having 1 to 10 carbon atoms, an alkoxy group, a hydroxyl group, (R) ₃ SiCH ₂ —, or (R) ₃ SiO—). At least two of R ¹ are alkenyl groups, and in the above formulas, R are independently of each other an unsubstituted or substituted monovalent hydrocarbon group having 1 to 10 carbon atoms, an alkoxy group, or An organopolysilmethylenesiloxane having at least two alkenyl groups bonded to a silicon atom, each represented by a group selected from a hydroxyl group, wherein m is 1 to 100 and n is an integer of 1 to 100. The following average composition formula (2):
[Chemical 2]
R ⁴ _e Cl _f Si (CH ₂ ) _{(4-ef) / 2} (2)
(R ⁴ is a group independently selected from an unsubstituted or substituted monovalent hydrocarbon group having 1 to 10 carbon atoms, and e and f are numbers satisfying e + f = 1.5 to 2.8. Provided that, however, organopolysilmethylene represented by 0.001 ≦ f / (e + f) ≦ 0.9),
The following general formula (3):
[Chemical 3]
R ⁵ _g R ⁶ _h SiCl _{4- (g + h)} (3)
(R ⁵ is independently selected from an unsubstituted or substituted monovalent hydrocarbon group having 1 to 10 carbon atoms, R ⁶ is an alkenyl group having 2 to 10 carbon atoms, and g is The method for producing an organopolysilmethylenesiloxane according to claim 1 by reaction with an alkenyl group-containing silane represented by 0-2, h is an integer of 1-3, g + h is 1-3.

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