JP4520137B2 - One-part organopolysiloxane gel composition - Google Patents

Description

  The present invention relates to a one-component organopolysiloxane gel composition, and more particularly to a one-component organopolysiloxane gel composition having good long-term storage stability at room temperature.

  Conventionally, an organohydrogenpolysiloxane having a hydrogen atom (SiH) bonded to a silicon atom, an organopolysiloxane having an alkenyl group such as a vinyl group bonded to a silicon atom, and a platinum-based catalyst, etc. Various addition reaction inhibitors are added to the addition reaction curable organopolysiloxane composition (hereinafter simply referred to as “composition”) to obtain a cured product by addition reaction (hydrosilylation reaction) with a platinum-based catalyst, It is well known that the progress of curing due to an addition reaction at room temperature is suppressed to improve long-term storage stability, and that the addition reaction is accelerated by heating at the time of use to cure. For example, it is known to blend an acetylene compound (Patent Document 1), a sulfoxide compound (Patent Document 2), or a hydroperoxide compound (Patent Document 3) as an addition reaction inhibitor.

However, for example, when using an organohydrogenpolysiloxane having a monofunctional unit represented by the formula: H (CH ₃ ) ₂ SiO _0.5 , that is, having SiH at the molecular chain end, the above reaction inhibitor is used. Even if it mix | blends, since the progress of hardening by the addition reaction in the room temperature of a composition cannot be suppressed effectively, the storage stability of the composition was not enough. Furthermore, in the case of a composition which is a combination of the above-described organohydrogenpolysiloxane having SiH at the molecular chain end and an alkenyl group-containing organopolysiloxane having a branched structure, long-term storage stability at room temperature can be achieved. It was even more difficult.

  In order to solve these problems, as an addition reaction inhibitor at room temperature for a composition containing a vinyl group-containing branched organopolysiloxane and an organohydrogenpolysiloxane having SiH at the molecular chain end, n-butylamine, N, It has been proposed to use amine compounds such as N-dibutylaminopropylamine and N, N, N ′, N′-tetramethylethylenediamine (Patent Document 4). However, since these amine compounds have a low boiling point, they are inferior in storage stability in an open system, and when an inorganic filler is blended in the composition, they are adsorbed on the surface of the inorganic filler. Since it has a drawback that the effect of suppressing the addition reaction is remarkably lowered, it has not been effective yet.

  On the other hand, the composition which mix | blended phosphite as an addition reaction inhibitor is well-known (patent document 5, patent document 6, patent document 7), and also contains a phosphorus compound and an organic peroxide as an addition reaction inhibitor. It is also known to use (Patent Document 8). However, in any of the above-mentioned patent documents, when a phosphite is used as an addition reaction inhibitor, an addition reaction at room temperature is effective in a composition containing an organohydrogenpolysiloxane having SiH at the molecular chain end. It is not described that it can be suppressed. Further, in the case of a composition containing a combination of an organohydrogenpolysiloxane having SiH at the molecular chain terminal and an alkenyl group-containing organopolysiloxane having a branched structure, a phosphite ester, or a phosphite ester and an organic peroxide. No mention is made that the addition reaction at room temperature can be suppressed by a combination with an oxide.

U.S. Pat. No. 3,445,420 U.S. Pat. No. 3,453,234 U.S. Pat. No. 4,061,609 U.S. Pat.No. 4,584,361, U.S. Pat.No. 3,188,300, JP-T-2001-508096 JP-T-2001-527111 JP-A-56-20051

  Therefore, even if the subject of the present invention is a composition containing a combination of an organohydrogenpolysiloxane having SiH at the molecular chain terminal and an alkenyl group-containing organopolysiloxane having a branched structure, An object of the present invention is to provide a one-component organopolysiloxane gel composition in which an addition reaction at room temperature is effectively suppressed even when an inorganic filler is blended therein, and the storage stability is maintained over a long period of time.

As a result of intensive studies aimed at solving the above problems, the present inventors have completed the present invention.
That is, the present invention
_{(A) R (CH 3)} SiO unit: 80.0 to 97.0 mol%, RSiO _1.5 unit: 1.0 to 10.0 _{mol%, (CH 3) 2 (} CH 2 = CH) SiO 0.5 units: 0.1 to 4.0 mol%, and ( CH ₃ ) ₃ SiO _0.5 unit: 0.5 to 10 mol%
[However, the total of these units is 100 mol%, in each unit formula representing these units, R represents a methyl group, a phenyl group, or a group of the _{formula,: RfCH 2 CH 2 - (} Rf is an ether in the chain A perfluoroalkyl group having or not having a bonding oxygen atom)]
A plurality of R contained in one molecule is the same or different, organopolysiloxane: 100 parts by weight,
(B) Formula: H (R ¹ ) ₂ SiO _0.5
[Wherein, R ¹ is independently an unsubstituted or substituted monovalent hydrocarbon group other than an alkenyl group]
An organohydrogenpolysiloxane having at least two units represented by the following formula: A vinyl atom in which the number of hydrogen atoms bonded to silicon atoms contained in this component is contained in the organopolysiloxane of component (A) An amount of 0.5 to 4.0 per base,
(C) platinum-based catalyst: effective amount,
(D) Phosphorous acid triester: the amount of phosphorus atom in the component is 2 mol or more with respect to 1 mol of platinum metal atom contained in the component (C), and (E) organic peroxidation. Product: One-component organo, characterized in that the amount of —OO— bond in the component is 2 mol or more per mol of phosphorus atom contained in the component (D) A siloxane gel composition is provided.

  The present invention has an organohydrogenpolysiloxane having a hydrogen atom at the end of a molecular chain bonded to a silicon atom and an aliphatic unsaturated group bonded to a silicon atom, which could not be stored for a long time at room temperature. Long-term storage even in the case of a one-pack type organopolysiloxane gel composition containing a branched organopolysiloxane and a platinum-based catalyst that promotes the addition reaction, and even when an inorganic filler is further added to the composition. While giving stability, there exists an outstanding effect that there is no influence on the heat-hardening property at the time of use.

Hereinafter, the present invention will be described in more detail.
-(A) Vinyl group-containing branched organopolysiloxane-
The organopolysiloxane of component (A) is used as the main agent (base polymer) of the composition of the present invention. As described above, R (CH ₃ ) SiO units: 80.0 to 97.0 mol%, RSIO _1.5 units: 1.0 ˜10.0 mol%, (CH ₃ ) ₂ (CH ₂ ═CH) SiO _0.5 unit: 0.1 to 4.0 mol%, and (CH ₃ ) ₃ SiO _0.5 unit: 0.5 to 10 mol% (the total of these units is 100 mol) %)).

Wherein R may be the same or different, a methyl group, a phenyl group, or a group of the _{formula,: RfCH 2 CH 2 - (} Rf has an etheric oxygen atom in the chain, or in no perfluoroalkyl group ).

The perfluoroalkyl group for Rf preferably has 1 to 12 carbon atoms, more preferably 1 to 8 carbon atoms when it does not have an etheric oxygen atom in the chain. Examples include groups represented by the formula: CF _3- , C ₄ F _9- , C ₈ F _17-, and the like.

Further, when Rf has an etheric oxygen atom in the chain, for example, the following general formula (1):
R'O- (R "O-) _p R"'-(1)
[Wherein, R ′ is a perfluoroalkyl group having 1 to 4 carbon atoms, R ″ and R ″ ′ are independently a perfluoroalkylene group having 1 to 3 carbon atoms, and p is 0 to 10 Is an integer. ]
It is group represented by these. Specifically, what is represented by a following formula is mentioned.
C ₂ F ₅ O- (CF ₂ CF ₂ O-) _s CF _2-
C ₃ F ₇ O- (CF ₂ CF ₂ CF ₂ O-) _t CF ₂ CF _2-
C ₃ F ₇ O— [CF (CF ₃ ) CF ₂ O—] _t CF (CF ₃ ) —
[In the above formula, s is an integer of 0 to 4, and t is an integer of 0 to 10]

The present (A) the above formula in the component: trifunctional unit represented by RSiO _1.5, the organopolysiloxane of the component (A) and that of the branched structure, and low-temperature characteristics and speed to the compositions of the present invention It is an important unit for imparting curing performance. As described above, the content of this unit is 1.0 to 10.0 mol%, preferably 1.5 to 10.0 mol%, and if the content is less than 1.0 mol%, the linear structure of component (A) increases. For this reason, the above-mentioned properties and performance are insufficiently imparted, and conversely, if it exceeds 10.0 mol%, there is a problem that it is difficult to control the viscosity.

The monofunctional unit represented by the above formula: (CH ₃ ) ₂ (CH ₂ ═CH) SiO _0.5 and the formula: (CH ₃ ) ₃ SiO _0.5 is a unit that becomes a terminal group. The former content is 0.1 to 4.0 mol%, preferably 0.5 to 3.0 mol%. If the content is less than 0.1 mol%, the curing characteristics due to the addition reaction are poor, and conversely if it exceeds 4.0 mol%. There arises a problem that the heat resistance of the cured product is poor. The latter of content from 0.5 to 10 mol%, preferably from 0.8 to 8 mol%, the total content of the former and the latter, the formula: the content of the trifunctional units represented by RSiO _1.5 (Ie, the proportion of the branched structure in the component (A)) is naturally determined.

  The organopolysiloxane of component (A) can be produced by a known method. For example, by a method in which chlorosilanes corresponding to each unit are mixed at a required molar ratio and subjected to cohydrolysis and condensation, or by an equilibration reaction of a polysiloxane and / or a cyclic siloxane compound having the structure of each unit. Manufactured.

  The organopolysiloxane of component (A) preferably has a viscosity at 25 ° C. in the range of usually 300 to 10,000 mPa · s.

Specific examples of the organopolysiloxane of component (A) are shown below, but are not limited thereto.
[(CH ₃ ) ₂ (CH ₂ = CH) SiO _0.5 ] _a [(CH ₃ ) ₃ SiO _0.5 ] _b [(CH ₃ ) ₂ SiO] _c [CH ₃ SiO _1.5 ] _d
[(CH ₃ ) ₂ (CH ₂ = CH) SiO _0.5 ] _a [(CH ₃ ) ₃ SiO _0.5 ] _b [(CH ₃ ) ₂ SiO] _c [CH ₃ SiO _1.5 ] _d [Ph ₂ SiO] _e
[(CH ₃ ) ₂ (CH ₂ = CH) SiO _0.5 ] _a [(CH ₃ ) ₃ SiO _0.5 ] _b [(CH ₃ ) ₂ SiO] _c [CH ₃ SiO _1.5 ] _d [(CH ₃ ) PhSiO] _f
[(CH ₃ ) ₂ (CH ₂ = CH) SiO _0.5 ] _a [(CH ₃ ) ₃ SiO _0.5 ] _b [(CH ₃ ) ₂ SiO] _c [PhSiO _1.5 ] _g
[(CH ₃ ) ₂ (CH ₂ = CH) SiO _0.5 ] _a [(CH ₃ ) ₃ SiO _0.5 ] _b [CH ₃ SiO _1.5 ] _d [(CH ₃ ) CF ₃ CH ₂ CH ₂ SiO] _h
[(CH ₃ ) ₂ (CH ₂ = CH) SiO _0.5 ] _a [(CH ₃ ) ₃ SiO _0.5 ] _b [CH ₃ SiO _1.5 ] _d [(CH ₃ ) C ₃ F ₇ O- {CF (CF ₃ ) _{CF 2 O-} iCF (CF 3} ) CH 2 CH 2 SiO] j
[(CH ₃ ) ₂ (CH ₂ = CH) SiO _0.5 ] _a [(CH ₃ ) ₃ SiO _0.5 ] _b [(CH ₃ ) ₂ SiO] _c [PhSiO _1.5 ] _k
(In the above formulas, a, b, c, d, e, f, g, h, i, j and k are each a positive integer selected so as to satisfy the above viscosity, and Ph is a phenyl group (C ₆ H ₅ -) shows a).
These organopolysiloxanes can be used singly or in combination of two or more.

-(B) Organohydrogenpolysiloxane-
The organohydrogenpolysiloxane as component (B)
Formula: H (R ¹ ) ₂ SiO _0.5
[Wherein, R ¹ is independently an unsubstituted or substituted monovalent hydrocarbon group other than an alkenyl group]
The compound contains at least two monofunctional diorganohydrogensiloxy units represented by the following formula. That is, in this organohydrogenpolysiloxane, hydrogen atoms are bonded to at least two molecular end silicon atoms.

R ¹ is an unsubstituted or substituted monovalent hydrocarbon group having 1 to 12 carbon atoms, more preferably 1 to 8 carbon atoms, and specifically includes, for example, a methyl group, an ethyl group, a propyl group. Bonded to carbon atoms of these groups; alkyl groups such as butyl groups; cycloalkyl groups such as cyclohexyl groups; aryl groups such as phenyl groups and tolyl groups; aralkyl groups such as benzyl groups and β-phenylpropyl groups; Chloromethyl group, 3,3,3-trifluoropropyl group, 2-cyanoethyl group, etc., in which some or all of the hydrogen atoms are substituted with halogen atoms, cyano groups, etc., among them methyl groups, phenyl groups, A 3,3,3-trifluoropropyl group is preferred.

Examples of the organohydrogenpolysiloxane include the following average composition formula (2):
(H) _a (R ⁶ ) _b SiO _{(4-ab) / 2} (2)
And at least two units represented by the formula: H (R ¹ ) ₂ SiO _0.5 (R ¹ is as described above) in one molecule.
In this average composition formula (2), a plurality of R ⁶ are independently the same unsubstituted or substituted monovalent hydrocarbon group as defined for R ¹ . Or two R < ⁶ > may form together and a lower alkylene group may be formed.

When R ⁶ is an unsubstituted or substituted monovalent hydrocarbon group, examples thereof include the same groups as R ¹ above. Among them, a methyl group, a phenyl group, and a 3,3,3-trifluoropropyl group are preferable.
Examples of the lower alkylene group formed by combining two R ⁶ groups include an ethylene group, a trimethylene group, a methylmethylene group, a tetramethylene group, and a hexamethylene group.
A is a number of 0 <a ≦ 2, b is a number of 0 <b ≦ 3, and 0 <a + b ≦ 3, and preferably 0.001 ≦ a ≦ 0.5, 0.8 ≦ b ≦ 2.2, 1 ≦ a + b ≦ 2.4.

The organohydrogenpolysiloxane represented by the above average composition formula (2) is as long as it contains at least two units represented by the formula: H (R ¹ ) ₂ SiO _0.5 in one molecule as described above. However, it is not particularly limited, and may be a linear or branched structure.

In addition, the organohydrogenpolysiloxane of component (B) has a viscosity at 25 ° C. of 1,000 mPa · s or less, usually 0.1 to 1000 mPa · s, particularly 0.5 to 500 mPa · s, particularly in that synthesis is easy. s is preferred.
When the component (B) is a linear organohydrogenpolysiloxane, for example, the following general formula (3):

（式中、Ｒ¹およびＲ⁶は上記のとおりであり、ｃおよびｄは同一または異なる０または正数であり、ｃ＋ｄは上記粘度を満足する数である）
で表すことができる。

(Wherein R ¹ and R ⁶ are as described above, c and d are the same or different 0 or a positive number, and c + d is a number satisfying the above viscosity)
Can be expressed as

Further, as the branched organohydrogenpolysiloxane, as a branching source, a unit represented by the formula: R ⁶ SiO _1.5 (R ⁶ is as described above), a unit represented by the formula: SiO ₂ , or The following structural formula (4):

（式中、Ｒ⁶は上記のとおりである）
で表される単位等を有するものを挙げることができる。

(Wherein R ⁶ is as described above)
What has a unit etc. which are represented by these can be mentioned.

Specific examples of the organohydrogenpolysiloxane of component (B) of the present invention are shown below, but are not limited thereto.
Dimethylpolysiloxane terminated with a dimethylhydrogensiloxy group at both ends of the molecular chain, methylphenylpolysiloxane terminated with a dimethylhydrosiloxy group at both ends of the molecular chain, and terminated with a dimethylhydrogensiloxy group at both ends of the molecular chain Dimethylsiloxane / methylphenylsiloxane copolymer, dimethylsiloxane / methylhydrogensiloxane copolymer terminated with dimethylhydrogensiloxy groups at both ends of the molecular chain, and terminated with dimethylhydrogensiloxy groups at both ends of the molecular chain Dimethylsiloxane / methylhydrogensiloxane / methylphenylsiloxane copolymer, dimethylsiloxane / methyltrifluoropropylsiloxane copolymer terminated with dimethylhydrogensiloxy groups at both ends of the molecular chain Formula siloxane units of the formula R ¹ ₃ SiO _0.5: siloxane units represented by the formula R ¹ ₂ HSiO _0.5: organopolysiloxane copolymers composed of siloxane units represented by SiO _2, wherein: R ¹ ₂ HSiO _An organopolysiloxane copolymer comprising a siloxane unit represented by _0.5 and a siloxane unit represented by the formula: SiO ₂ , a siloxane unit represented by the formula: R ¹ ₂ HSiO _0.5 and a siloxane unit represented by the formula: R ¹ SiO _1.5 An organopolysiloxane copolymer comprising: a siloxane unit represented by the formula: R ¹ ₂ HSiO _0.5 ; a siloxane unit represented by the formula: R ¹ ₂ SiO; and a siloxane unit represented by the formula: R ¹ SiO _1.5 Polymer (in the above formulas, R ¹ is as described above).
These organohydrogenpolysiloxanes can be used singly or in combination of two or more.

  The blending ratio of the component (B) in the composition of the present invention is such that the obtained cured product has good physical properties such as heat resistance and mechanical strength, and is required not to foam during curing. The number of hydrogen atoms bonded to silicon atoms contained in the component (B) is O.5-4.O, particularly 0.8-, per vinyl group contained in the organopolysiloxane of the component (A). The ratio is preferably 3.0.

-(C) Platinum-based catalyst-
The platinum-based catalyst of component (C) is blended in order to promote the addition reaction between the vinyl group in component (A) and SiH in component (B) and obtain a cured product of the composition of the present invention. It is a well-known component.

  As the component (C), for example, the following general formula (5):

、下記一般式(6)：

The following general formula (6):

［上記各式中、Ｒ⁷は独立に非置換または置換の１価炭化水素基であり、ｍは０〜３、ｎは３〜６、ｍ＋ｎの和は３〜９の整数である］
等で表されるビニル基含有オルガノポリシロキサンを配位子とする白金錯体が好適に用いられる。

[In the above formulas, R ⁷ is independently an unsubstituted or substituted monovalent hydrocarbon group, m is 0 to 3, n is 3 to 6, and the sum of m + n is an integer of 3 to 9.]
A platinum complex having a vinyl group-containing organopolysiloxane represented by the above formula as a ligand is preferably used.

R ⁷ is an unsubstituted or substituted monovalent hydrocarbon group having 1 to 12 carbon atoms, more preferably 1 to 8 carbon atoms, such as a methyl group, an ethyl group, a propyl group, or a butyl group. An alkenyl group such as a vinyl group, an allyl group or a propenyl group; a cycloalkyl group such as a cyclohexyl group; an aryl group such as a phenyl group or a tolyl group; an aralkyl group such as a benzyl group or a β-phenylpropyl group; A chloromethyl group, a 3,3,3-trifluoropropyl group, a 2-cyanoethyl group, etc. in which a part or all of the hydrogen atoms bonded to the carbon atoms of these groups are substituted with a halogen atom, a cyano group, etc. Of these, a methyl group, a vinyl group, a phenyl group, and a 3,3,3-trifluoropropyl group are preferable.

  (C) component which is this platinum complex is well-known, For example, as described in Japanese Patent Publication No. 47-23679, it is represented by chloroplatinic acid and the above general formulas (5), (6), etc. It can be produced by subjecting a low molecular siloxane to a heat reaction in the presence of a basic salt.

Specific examples of the platinum-based catalyst of the component (C) of the present invention include, for example, platinum / 1,3-divinyl-1,1,3,3-tetramethyldisiloxane complex, platinum / 2,4,6,8. Examples include, but are not limited to, tetramethyl-2,4,6,8-tetravinylcyclotetrasiloxane complex.
The platinum-based catalyst can be used alone or in combination of two or more.

  The blending amount of the component (C) in the composition of the present invention is not particularly limited as long as it is an effective amount as a catalyst, but the weight of the platinum metal atom with respect to the total amount of the components (A) and (B). As a general rule, it may be blended in the range of 0.5 to 500 ppm, preferably 1 to 100 ppm, more preferably about 5 to 50 ppm. If the amount is too small, the addition reaction is remarkably slow or does not cure, while if too large, the heat resistance of the polysiloxane composition after curing is reduced, and platinum is expensive because of its high cost. Is disadvantageous.

-(D) Phosphite triester-
The component (D) is preferably represented by the general formula: P (OR ² ) ₃
[Wherein R ² is independently an unsubstituted or substituted monovalent hydrocarbon group and the formula: —R ⁴ [—O—P (OR ³ ) ₂ ] _x (wherein R ³ is independently unsubstituted or substituted) And x is an integer of 1 to 3, and R ⁴ is a divalent to tetravalent hydrocarbon having 2 to 20 carbon atoms having or not having an etheric oxygen atom in the chain. Is at least one group selected from the group consisting of groups represented by:
Or phosphorous acid triester represented by the following general formula:

［式中、Ｒ³は前記と同じであり、Ｒ⁵は鎖中にエーテル結合性酸素原子を有する、または有しない炭素原子数１〜20の４価の炭化水素基である］
で表される亜リン酸トリエステルである。この(D)成分は、上記(C)成分の白金系触媒の室温における付加反応に対する触媒能を抑制する機能を有する

[Wherein, R ³ is the same as defined above, and R ⁵ is a tetravalent hydrocarbon group having 1 to 20 carbon atoms having or not having an etheric oxygen atom in the chain]
It is a phosphorous acid triester represented by these. This component (D) has a function of suppressing the catalytic ability of the platinum catalyst of the above component (C) for the addition reaction at room temperature.

R ² is an unsubstituted or substituted monovalent hydrocarbon group having 1 to 20 carbon atoms, more preferably 1 to 15 carbon atoms, such as a methyl group, an ethyl group, a propyl group, or a butyl group. , Pentyl group, hexyl group, octyl group, isopropyl group, isobutyl group, tert-butyl group, neopentyl group, 2-ethylhexyl group and other alkyl groups; vinyl group, allyl group, propenyl group and other alkenyl groups; cyclohexyl group and the like A cycloalkyl group; an aryl group such as a phenyl group and a tolyl group; an aralkyl group such as a benzyl group and a β-phenylpropyl group; and a part or all of the hydrogen atoms bonded to the carbon atoms of these groups are halogen atoms, cyano And a chloromethyl group, a 3,3,3-trifluoropropyl group, a 2-cyanoethyl group and the like substituted with a group.

R ³ is an unsubstituted or substituted monovalent hydrocarbon group independently may be, for example, those same as those exemplified as unsubstituted or substituted monovalent hydrocarbon group for R ² mentioned above.
R ⁴ is a divalent to tetravalent hydrocarbon group having 2 to 20 carbon atoms, preferably 2 to 12 carbon atoms, having or not having an etheric oxygen atom in the chain.
R ⁵ have an etheric oxygen atom in the chain or with 1 to 20 carbon atoms having no, preferably 5 to 20, the tetravalent hydrocarbon group.

Specific examples of the phosphorous acid triester of component (D) of the present invention are shown below, but are not limited thereto.
Triethyl phosphite: (EtO) ₃ P, trioctyl phosphite: [Me (CH ₂ ) ₇ O] ₃ P, tris (2-ethylhexyl) phosphite: [MeC ₃ H ₆ CH (Et) CH ₂ O] ₃ P, triphenyl phosphite: (PhO) ₃ P, diphenyl mono (2-ethylhexyl) phosphite: (PhO) ₂ (MeC ₃ H ₆ CH (Et) CH ₂ O) P, tris (2,4-di- tert-Butylphenyl) phosphite:

、テトラフェニルジプロピレングリコールジフォスファイト：(ＰｈＯ)₂ＰＯ-[ＣＨ(Ｍｅ)-ＣＨ₂Ｏ]₂-Ｐ(ＯＰｈ)₂、テトラフェニルテトラ(トリデシル)ペンタエリスリト−ルテトラホスファイト：[(ＰｈＯ)(Ｃ₁₃Ｈ₂₇Ｏ)Ｐ-ＯＣＨ₂]₄Ｃ、テトラ(トリデシル)-4,4'-イソプロピリデンジフェニルジホスファイト：(Ｃ₁₃Ｈ₂₇Ｏ)₂ＰＯ-Ｐｈ-Ｃ(Ｍｅ)₂-Ｐｈ-ＯＰ(ＯＣ₁₃Ｈ₂₇)₂、ビス(トリデシル)ペンタエリスリトールジホスファイト：

Tetraphenyldipropylene glycol diphosphite: (PhO) ₂ PO— [CH (Me) —CH ₂ O] ₂ —P (OPh) ₂ , tetraphenyltetra (tridecyl) pentaerythritol tetraphosphite: [ _{(PhO) (C 13 H 27} O) P-OCH 2] 4 C, tetra (tridecyl) -4,4'-isopropylidene diphenyl _{diphosphite: (C 13 H 27 O)} 2 PO-Ph-C (Me ) ₂ -Ph-OP (OC ₁₃ H ₂₇ ) ₂ , bis (tridecyl) pentaerythritol diphosphite:

（上記式中、Ｍｅ、Ｅｔ、Ｂｕは、それぞれ、メチル基、エチル基、ブチル基を示し、Ｐｈは、フェニル基またはフェニレン基を示す。）
これらの亜リン酸トリエステルは、１種単独でも２種以上組み合わせても使用することができる。

(In the above formulas, Me, Et, and Bu represent a methyl group, an ethyl group, and a butyl group, respectively, and Ph represents a phenyl group or a phenylene group.)
These phosphorous acid triesters can be used singly or in combination of two or more.

  The blending amount of the phosphorous acid triester of the component (D) is such that the amount of phosphorus atoms in the component (D) is 2 moles or more per mole of platinum metal atoms contained in the component (C). The amount is preferably 3 mol or more. If the amount is less than 2 mol, the catalytic ability for the addition reaction of the platinum-based catalyst at room temperature cannot be completely suppressed. The upper limit of the amount of the phosphite triester is not particularly limited because it varies depending on the coordination ability of the phosphite triester to the platinum metal atom and the oxidation ability of the component (E), but the heating of the composition Since it is necessary not to impair the curability, the blending amount may be about 2 to 10 mol.

− (E) Organic peroxide−
The organic peroxide of the component (E) has a function of effectively suppressing the catalytic ability for the addition reaction of the platinum catalyst together with the component (D) in the long-term storage of the composition at room temperature. Moreover, in the heat curing stage, it decomposes at its decomposition temperature and loses its own inhibitory action, and also oxidizes the above (D) component, thereby deactivating the inhibitory action of the (D) component. The composition can be quickly and reliably cured by the platinum-based catalyst.

  Examples of the organic peroxide include ketone peroxides such as methyl ethyl ketone peroxide, cyclohexane nonperoxide, methyl acetoacetate peroxide, and acetylacetone peroxide; 1,1-bis (t-butylperoxy) -3,3 Peroxyketals such as 1,5-trimethylcyclohexane and 2,2-bis (t-butylperoxy) butane; 1,1,3,3-tetramethylbutyl hydroperoxide, cumene hydroperoxide, t-butyl hydroper Hydroperoxides such as oxides; Dialkyl peroxides such as 2,5-dimethyl-2,5-bis (t-butylperoxy) hexane and di-t-butyl peroxide; 3,5,5-trimethylhexanoyl peroxide Diacyl peroxides such as oxide and m-toluyl peroxide; diisopropyl peroxydica Peroxycarbonates such as bonate and di-2-ethylhexylperoxydicarbonate; t-butylperoxy-3,5,5-trimethylhexanoate, t-butylperoxyisopropylmonocarbonate, t-butylperoxy And peroxyesters such as 2-ethylhexyl monocarbonate and t-butylperoxybenzoate. These can be used singly or in combination of two or more.

  The amount of component (E) is such that the amount of —OO— bonds in component (E) is 2 mols or more, preferably 3 mols or more per mol of phosphorus atoms contained in component (D). This is the amount. If the blending amount is less than 2 mol, the catalytic ability for the addition reaction of the platinum-based catalyst at room temperature cannot be completely suppressed, and the catalytic ability suppressing action of the component (D) is completely deactivated in the heat curing stage. I can't. The upper limit of the amount of the organic peroxide is not particularly limited, but the amount of the organic peroxide may be about 15 mol because the decomposition residue has an effect on the curing characteristics.

-Other ingredients-
In the composition of the present invention, as optional components to be blended in addition to the above components (A) to (E), for example, fumed silica, crystalline silica, precipitated silica, hollow filler, silsesquioxane, fumed titanium dioxide Inorganic fillers such as magnesium oxide, zinc oxide, iron oxide, aluminum hydroxide, magnesium carbonate, calcium carbonate, zinc carbonate, layered mica, carbon black, diatomaceous earth, and glass fiber; and organoalkoxy for these fillers You may mix | blend the filler surface-treated with organosilicon compounds, such as a silane compound, an organochlorosilane compound, an organosilazane compound, and a low molecular weight siloxane compound. Silicone rubber powder, silicone resin powder, and the like may also be blended.

  Furthermore, the composition of the present invention does not contain, as an optional component, for example, a linear organopolysiloxane containing an alkenyl group, a silicon atom-bonded hydrogen atom, and an alkenyl group, as long as the object of the present invention is not impaired. Organopolysiloxane, heat resistance imparting agent, flame retardancy imparting agent, thixotropic property imparting agent, pigment, dye and the like may be blended.

[ Reference Example 1]
(A) CH ₂ = CH (CH ₃ ) ₂ SiO _0.5 unit / (CH ₃ ) ₃ SiO _0.5 unit / (CH ₃ ) ₂ SiO unit / CH ₃ SiO _1.5 unit = 0.7 mol% / 7 mol% / 83.2 mol% / The content of hydrogen atoms (SiH) bonded to silicon atoms is 0.068% by weight in 100 parts of an organopolysiloxane having a molar ratio of 9.1 mol% and a viscosity of 2,000 mPa · s at 25 ° C. , 10 parts of dimethylpolysiloxane terminated with a dimethylhydrogensiloxy group (number of SiHs / number of vinyl groups in component (A) = 0.7), (C) chloroplatinic acid / 1,3-divinyltetramethyl Disiloxane complex (platinum metal atom content: 1% by weight) 0.05 parts (as platinum metal atom weight, 5 ppm with respect to the total amount of (A) + (B)), (D) trioctyl phosphite 0.0032 parts ( Phosphorus atom in the component / platinum metal atom in the component (C) (molar ratio) = 3), and (E) t-butylperoxy · 3 , 5,5-Trimethylhexanoate 0.012 parts (-OO-bond in the component / phosphorus atom in the component (D) (molar ratio) = 6.5) were uniformly mixed to obtain a composition. The resulting composition was allowed to stand at 40 ° C. for 1 month in a closed system in the container, but the composition did not thicken at all.

  Next, the composition was cured by heating at 130 ° C. for 30 minutes to obtain a transparent gel. As a result of measuring the hardness of this gel-like material according to the JIS K 2220 (1/4 cone) consistency test method, it was 20. Further, the hardness of the gel-like product obtained by immediately heating and curing the composition obtained by mixing the components (A) to (E) under the same conditions as described above was 20.

[ Reference Example 2]
(A) CH ₂ = CH (CH ₃ ) ₂ SiO _0.5 unit / (CH ₃ ) ₃ SiO _0.5 unit / (C ₆ H ₅ ) ₂ SiO unit / (CH ₃ ) ₂ SiO unit / CH ₃ SiO _1.5 unit = 0.85 100 parts of an organopolysiloxane having a molar ratio of mol% / 0.9 mol% / 2.1 mol% / 94.65 mol% / 1.5 mol% and a viscosity at 25 ° C. of 1,000 mPa · s, which is blocked with a trimethylsiloxy group 60 parts of a dimethylsiloxane-diphenylsiloxane copolymer having a viscosity of 700 mPa · s at 25 ° C. and containing 3 mol% of diphenylsiloxane units, and (B1) the content of hydrogen atoms bonded to silicon atoms is 0.068% by weight 6.9 parts of dimethylpolysiloxane terminated with dimethylhydrogensiloxy group, (B2) the content of hydrogen atom bonded to silicon atom is 0.04% by weight, and 50% of the terminal is dimethylhydrogensiloxy group Stopped and left 12 parts of dimethylpolysiloxane blocked with a trimethylsiloxy group (number of SiH in (B1) + (B2) / number of vinyl groups in (A) = 0.9), (C) chloroplatinic acid / 1 , 3-divinyltetramethyldisiloxane complex (platinum metal atom content: 1% by weight) 0.05 parts (as platinum metal atom weight, 5 ppm with respect to the total amount of (A) + (B1) + (B2)), (D) Triphenyl phosphite 0.00235 parts (phosphorus atom in the component / platinum metal atom (molar ratio) in the component (C) = 3), (E) 1,1-bis (t-butylperoxy)- 0.0075 part of 3,3,5-trimethylcyclohexane (-OO-bond in the component / phosphorus atom in component (D) (molar ratio) = 6.5) was uniformly mixed to obtain a composition.

The resulting composition was allowed to stand at 40 ° C. for 1 month in a closed system in the container, but the composition did not thicken at all.
Next, the composition was cured by heating at 130 ° C. for 30 minutes to obtain a transparent gel. As a result of measuring the hardness of this gel-like material according to the JIS K 2220 (1/4 cone) consistency test method, it was 115. Further, the hardness of the gel-like product obtained by immediately heating and curing the composition obtained by mixing the components (A) to (E) under the same conditions as described above was 115.

[ Reference Example 3]
(A) CH ₂ = CH (CH ₃ ) ₂ SiO _0.5 unit / (CH ₃ ) ₃ SiO _0.5 unit / (CH ₃ ) ₂ SiO unit / CH ₃ SiO _1.5 unit = 1.24 mol% / 2.7 mol% / 92.86 mol% / Mole ratio of 3.2 mol%, 100 parts of organopolysiloxane having a viscosity at 25 ° C. of 400 mPa · s, (B) The content of hydrogen atoms bonded to silicon atoms is 0.13% by weight, and the terminal is dimethylhydro 8 parts of dimethylpolysiloxane terminated with gensiloxy group (number of SiH / number of vinyl groups in component (A) = 0.6), (C) chloroplatinic acid / 1,3-divinyltetramethyldisiloxane complex (platinum) Metal atom content: 1% by weight) 0.05 parts (as platinum metal atom weight, 5 ppm with respect to the total amount of (A) + (B)), (D) trioctyl phosphite 0.0032 parts (phosphorus in the component) Atoms / platinum metal atoms in (C) component (molar ratio) = 3), (E1) 1,1-bis (t-butylperoxy) -3,3,5-tri 0.0064 parts of tilcyclohexane (-OO-bond in the component / phosphorus atom (molar ratio) in component (D) = 5.5), (E2) 0.0024 part of methyl acetoacetate peroxide (-OO-bond in the component / The phosphorus atom (molar ratio) = 1) in component (D) was uniformly mixed to obtain a composition.

When the obtained composition was allowed to stand at 40 ° C. in a closed system in the container, the viscosity increased significantly after 20 days.
Next, the composition was cured by heating at 130 ° C. for 30 minutes to obtain a transparent gel. The gel was measured for hardness according to JIS K 2220 (1/4 cone) consistency test method and found to be 87. Further, the hardness of the gel-like product obtained by immediately heating and curing the composition obtained by mixing the components (A) to (E) under the same conditions as described above was 87.

[Example 1 ]
Surface treated with hexamethyldisilazane, except for adding hydrophobic silica 2 parts by weight of the specific surface area of 170m ² / g with a trimethylsilyl group on the surface, the composition was uniformly mixed in the same as in Reference Example 2 Obtained.

The resulting composition was stored for 1 month at 40 ° C. in a closed system in the container, but there was no thickening of the composition.
Next, the composition was cured by heating at 130 ° C. for 30 minutes to obtain a transparent gel. As a result of measuring the hardness of this gel-like material according to the JIS K 2220 (1/4 cone) consistency test method, it was 110. Further, the hardness of the gel-like material obtained by immediately heat-curing the composition obtained by mixing the components (A) to (E) and the hydrophobic silica under the same conditions as described above is 110. Met.

[Comparative Example 1]
(E) A uniform composition was obtained in the same manner as in Reference Example 1 except that 0.0019 part of t-butylperoxy • 3,5,5-trimethylhexanoate was not used. The resulting composition was heated at 130 ° C. for 30 minutes but did not cure.

[Comparative Example 2]
(D) Trioctyl phosphite 0.0011 parts (phosphorus atom in the component / platinum metal atom (molar ratio) in the component (C) = 1) is used, and (E) t-butylperoxy-3,5, except for not using the 0.012 parts of 5-trimethyl hexanoate, to obtain a homogeneous composition the same as example 1.
The resulting composition gelled after 24 hours at 25 ° C., and the resulting gelled product had a penetration of 20.

[Comparative Example 3]
(E) 0.0018 part of t-butylperoxy-3,5,5-trimethylhexanoate (-OO-bond in the component / phosphorus atom (molar ratio) in component (D) = 1) Except for the above, a uniform composition was obtained in the same manner as in Reference Example 1. The resulting composition was heated at 130 ° C. for 30 minutes, but did not cure.

Claims (3)

_{(A) R (CH 3)} SiO unit: 80.0 to 97.0 mol%, RSiO _1.5 unit: 1.0 to 10.0 _{mol%, (CH 3) 2 (} CH 2 = CH) SiO 0.5 units: 0.1 to 4.0 mol%, and ( CH ₃ ) ₃ SiO _0.5 unit: 0.5 to 10 mol%
[However, the total of these units is 100 mol%, in each unit formula representing these units, R represents a methyl group, a phenyl group, or a group of the _{formula,: RfCH 2 CH 2 - (} Rf is an ether in the chain A perfluoroalkyl group having or not having a bonding oxygen atom)]
A plurality of R contained in one molecule is the same or different, organopolysiloxane: 100 parts by weight,
(B) _{^{formula: H (R 1) 2 SiO}} 0.5
[Wherein, R ¹ is independently an unsubstituted or substituted monovalent hydrocarbon group other than an alkenyl group]
An organohydrogenpolysiloxane having at least two units represented by the following formula: A vinyl atom in which the number of hydrogen atoms bonded to silicon atoms contained in this component is contained in the organopolysiloxane of component (A) An amount of 0.5 to 4.0 per base,
(C) platinum-based catalyst: effective amount,
(D) Phosphorous acid triester: An amount such that the amount of phosphorus atoms in the component is 2 mol or more with respect to 1 mol of platinum metal atoms contained in the component (C),
(E) Organic peroxide: an amount in which the amount of —OO— bond in the component is 2 mol or more with respect to 1 mol of phosphorus atoms contained in the component (D), and (F) an inorganic filler. : one-organosiloxane gel composition characterized by comprising a quantity <br/> give gel cured product of the composition. The phosphorous acid triester of the component (D)
General formula: P (OR ² ) ₃
[Wherein R ² is independently an unsubstituted or substituted monovalent hydrocarbon group and the formula: —R ⁴ [—O—P (OR ³ ) ₂ ] _x (wherein R ³ is independently unsubstituted or substituted) And x is an integer of 1 to 3, and R ⁴ is a divalent to tetravalent hydrocarbon having 2 to 20 carbon atoms having or not having an etheric oxygen atom in the chain. Is at least one group selected from the group consisting of groups represented by:
Or phosphorous acid triester represented by the following general formula:

[Wherein, R ³ is the same as defined above, and R ⁵ is a tetravalent hydrocarbon group having 1 to 20 carbon atoms having or not having an etheric oxygen atom in the chain]
The composition of Claim 1 which is a phosphorous acid triester represented by these.   The composition according to claim 1 or 2, wherein the inorganic filler of the component (F) is fumed silica, crystalline silica, precipitated silica, or a filler obtained by surface-treating these with an organosilicon compound.