JP2021038352A - Millable silicone rubber composition and cured product thereof - Google Patents

Abstract

To provide a millable silicone rubber composition that has its plasticity to rise by an economical method without requiring the addition of an expensive compound or a long-term heat treatment at high temperature.SOLUTION: A millable silicone rubber composition contains (A) an organopolysiloxane free of a hydroxy group and having a degree of polymerization of 100 or more of 100 pts.mass, (B) a linear organopolysiloxane with one terminal of a molecular chain being an aliphatic unsaturated group and the other terminal being a silanol group of 1-50 pts.mass, (C) a reinforcing silica of 5-100 pts.mass, (D) a nitrogen atom-containing organic silicon compound having two or more substituted aminoxy groups on average per molecule of 0.001-15 pts.mass, and (E) a curing agent.SELECTED DRAWING: None

Description

The present invention relates to a miraculous silicone rubber composition and a cured product thereof.

Silicone rubber has excellent weather resistance, electrical properties, low compression set, heat resistance, cold resistance, etc., so it is widely used in various fields such as electrical equipment, automobiles, construction, medical care, and food. It is used. For example, rubber contacts used as rubber contacts for remote controllers, typewriters, word processors, computer terminals, musical instruments, etc .; construction gaskets; various rolls such as copier rolls, development rolls, transfer rolls, charging rolls, and paper feed rolls. Anti-vibration rubber for audio equipment, etc .; Applications such as packing for compact discs used in computers can be mentioned. At present, the demand for silicone rubber is increasing more and more, and the development of silicone rubber having excellent properties is desired. These silicone rubbers are generally hardeners (ie, non-liquid raw rubber-like organopolysiloxanes that do not self-fluid at room temperature) and a reinforcing filler. A mirable silicone rubber compound (that is, a compound that can be kneaded with a kneader such as a roll mill) before blending (vulcanizing agent), and a mirable silicone rubber composition (that is, a roll mill, etc.) in which a curing agent is blended with this compound. It is used in the form of a composition that can be kneaded with a kneader. In this miraculous silicone rubber compound and silicone rubber composition, a reinforcing filler and various dispersants are mixed with a raw material polymer (raw rubber-like organopolysiloxane) by using a mixing device such as a kneader or a double roll (roll mill). It is prepared by

In order to produce a miraculous silicone rubber compound and a silicone rubber composition, as described above, it is necessary to knead a reinforcing filler such as fumed silica into the organopolysiloxane, and at that time, a dispersant (dispersant ( A surface treatment agent of a reinforcing filler called Wetter) is used. Usually, when a reinforcing filler such as silica is dispersed in an organopolysiloxane, an organosilane or a siloxane having a silanol group is used. By using a large amount of this surface treatment agent, crepe curing (return to plasticity) can be suppressed, but the plasticity of the silicone rubber compound or silicone rubber composition decreases, and it adheres to the surface of the silicone rubber compound or silicone rubber composition. There was a drawback that a feeling was generated and the workability was deteriorated. On the other hand, if the amount of the surface treatment agent added is not sufficient, the plasticity is increased, but there is a problem that the crepe curing (return to plasticization) is increased.

A resin is added to JP-A-6-256658 (Patent Document 1), and a polycyclic aromatic compound having two or more phenyl groups is added to JP-A-5-065415 (Patent Document 2). Although it is stated that the plasticity can be increased by doing so, there is no description about the plastic return and it is expensive. Further, Japanese Patent Application Laid-Open No. 7-133356 (Patent Document 3) describes that the plasticization return can be suppressed by heating the silicone rubber compound at 200 to 250 ° C. for 4 to 12 hours, but it is not economical. .. Japanese Unexamined Patent Publication No. 2015-214635 (Patent Document 4) describes that the plasticity is increased by adding a condensation reaction catalyst such as an organosilane with both ends silanol groups and / or a siloxane and an organic titanium compound. However, it is necessary to add it at the time of compounding silica and heat it after adding the condensation catalyst.

Japanese Unexamined Patent Publication No. 6-256658 Japanese Unexamined Patent Publication No. 5-055451 Japanese Unexamined Patent Publication No. 7-133356 Japanese Unexamined Patent Publication No. 2015-214635

The present invention has been made in view of the above circumstances, and is a miraculous silicone rubber composition whose plasticity is increased by an economical method without the need for addition of an expensive compound or heat treatment at a high temperature for a long time, and its curing. The purpose is to provide things.

As a result of diligent studies to achieve the above object, the present inventor uniformly kneads using an organopolysiloxane raw rubber (base polymer) having a degree of polymerization of 100 or more (particularly 1,000 or more) and reinforcing silica. When (mixing) to prepare a silicone rubber compound, and / or after preparation, an organopolysiloxane having one end of the molecular chain having an aliphatic unsaturated group and the other end having a silanol group was used to obtain an aminoxi group. It has been found that a miraculous silicone rubber compound having an increased degree of plasticity can be obtained by adding an organosilicon compound containing an average of two or more nitrogen atoms per molecule, and the present invention has been completed.

（式中、Ｒ²は脂肪族不飽和基であり、Ｒ³は同一又は異種の非置換若しくは置換の１価炭化水素基であり、ｎは１００以上の正数である。）
で表されるオルガノポリシロキサン １〜５０質量部、
（Ｃ）ＢＥＴ吸着法による比表面積が５０ｍ²／ｇ以上の補強性シリカ
５〜１００質量部、
（Ｄ）ケイ素原子に結合した下記式（３）及び（４）で表される置換アミノキシ基から選ばれる１種又は２種以上の基を１分子あたり平均２個以上有する窒素原子含有有機ケイ素化合物 ０．００１〜１５質量部、

（式中、Ｒ⁴及びＲ⁵は互いに同一又は異種の１価炭化水素基である。Ｒ⁶は２価の有機基である。）
（Ｅ）硬化剤 有効量
を含有することを特徴とするミラブル型シリコーンゴム組成物。
２．
（Ｄ）成分が、下記式（５）〜（８）で表される有機ケイ素化合物から選ばれる１種又は２種以上である上記１記載のミラブル型シリコーンゴム組成物。

（式中、Ｒ⁷は同一又は異種の置換若しくは非置換１価炭化水素基であり、ＯＹは上記式（３）又は（４）で示される基、ｂは０、１又は２、ｃは０又は１０以下の正数である。ｌは１〜２０の正数、ｍは２〜２０の正数であり、且つｌ＋ｍは３以上の正数である。Ｒ’はＲ⁷又はＯＹであり、ｐ、ｑはそれぞれ独立に０又は１００以下の正数であり、ｑが０以上１未満の場合は２つのＲ’はＯＹであり、ｑが１以上２未満の場合はＲ’の少なくとも１つはＯＹである。Ｑは炭素数１〜２０の２価炭化水素基である。）
３．
（Ｅ）成分の硬化剤が、オルガノハイドロジェンポリシロキサンとヒドロシリル化触媒との組み合せからなる付加反応硬化型である上記１又は２に記載のミラブル型シリコーンゴム組成物。
４．
（Ｅ）成分の硬化剤が有機過酸化物である上記１又は２に記載のミラブル型シリコーンゴム組成物。
５．
上記１〜４のいずれかに記載のミラブル型シリコーンゴム組成物を硬化してなるシリコーンゴム硬化物。 Therefore, the present invention provides the following miraculous silicone rubber composition and a cured silicone rubber composition obtained by curing the composition.
1. 1.
(A) The following average composition formula (1)
R ¹ _a SiO _{(4-a) / 2} (1)
(In the formula, R ¹ is the same or different unsubstituted or substituted monovalent hydrocarbon group, and a is a positive number of 1.95 to 2.05.)
100 parts by mass of organopolysiloxane having a degree of polymerization of 100 or more, represented by
(B) The following formula (2)

(In the formula, R ² is an aliphatic unsaturated group, R ³ is the same or different unsubstituted or substituted monovalent hydrocarbon group, and n is a positive number of 100 or more.)
Organopolysiloxane represented by 1 to 50 parts by mass,
(C) Reinforcing silica with a specific surface area of 50 m ² / g or more by the BET adsorption method
5 to 100 parts by mass,
(D) A nitrogen atom-containing organosilicon compound having one or more groups selected from the substituted aminoxy groups represented by the following formulas (3) and (4) bonded to a silicon atom on average at least two per molecule. 0.001 to 15 parts by mass,

(In the formula, R ⁴ and R ⁵ are monovalent hydrocarbon groups that are the same as or different from each other. R ⁶ is a divalent organic group.)
(E) A miraculous silicone rubber composition containing an effective amount of a curing agent.
2.
The mirable silicone rubber composition according to 1 above, wherein the component (D) is one or more selected from the organosilicon compounds represented by the following formulas (5) to (8).

(In the formula, R ⁷ is the same or different substituted or unsubstituted monovalent hydrocarbon group, OY is the group represented by the above formula (3) or (4), b is 0, 1 or 2, and c is 0. Or a positive number of 10 or less. L is a positive number of 1 to 20, m is a positive number of 2 to 20, and l + m is a positive number of 3 or more. R'is R ⁷ or OY. p and q are independently positive numbers of 0 or 100, respectively. When q is 0 or more and less than 1, two R'are OY, and when q is 1 or more and less than 2, at least one of R'. Is OY. Q is a divalent hydrocarbon group having 1 to 20 carbon atoms.)
3. 3.
The miraculous silicone rubber composition according to 1 or 2 above, wherein the curing agent for the component (E) is an addition reaction curing type comprising a combination of an organohydrogenpolysiloxane and a hydrosilylation catalyst.
4.
The miraculous silicone rubber composition according to 1 or 2 above, wherein the curing agent of the component (E) is an organic peroxide.
5.
A silicone rubber cured product obtained by curing the miraculous silicone rubber composition according to any one of 1 to 4 above.

In the present invention, the mixture obtained by blending the above components (A) to (D) and before blending the curing agent is referred to as a (mirable type) silicone rubber compound, and the compound blended with the curing agent is (mirable). Type) Silicone rubber composition.

According to the mirable type silicone rubber composition of the present invention, one end of the molecular chain is an aliphatic unsaturated group and the other end is a silanol group without adding an expensive compound or heat-treating at a high temperature for a long time. The plasticity can be economically increased by adding an organopolysiloxane and a nitrogen atom-containing organosilicon compound having a predetermined substituted aminoxi group, and by curing this, a silicone rubber cured product can be given. ..

Hereinafter, the present invention will be described in more detail.

-(A) component-
In the present invention, the component (A) is a main agent (base polymer) in the migrable silicone rubber composition, and is an organopolysiloxane having a degree of polymerization of 100 or more represented by the following average composition formula (1).
R ¹ _a SiO _{(4-a) / 2} (1)
(In the formula, R ¹ is the same or different unsubstituted or substituted monovalent hydrocarbon group, and a is a positive number of 1.95 to 2.05.)

In the above average composition formula (1), R ¹ is the same or different unsubstituted or substituted monovalent hydrocarbon group. The monovalent hydrocarbon group usually preferably has 1 to 12 carbon atoms, particularly preferably 1 to 8 carbon atoms, and specifically, a methyl group, an ethyl group, a propyl group, a butyl group, a hexyl group, an octyl group and the like. Cycloalkyl group such as alkyl group, cyclopentyl group, cyclohexyl group, alkenyl group such as vinyl group, allyl group, propenyl group, butenyl group, hexenyl group, cycloalkenyl group such as cyclohexenyl group, aryl such as phenyl group and tolyl group. An aralkyl group such as a group, a benzyl group or a 2-phenylethyl group, or a part or all of the hydrogen atom of these groups is replaced with a halogen atom such as fluorine or chlorine or a cyano group, for example, a chloromethyl group or a trifluoro group. Examples thereof include a propyl group and a cyanoethyl group. Among the above, a methyl group, a vinyl group, a phenyl group and a trifluoropropyl group are preferable, and a methyl group and a vinyl group are particularly preferable.

In particular, the organopolysiloxane as the component (A) has two or more, usually 2 to 50, particularly about 2 to 20 alkenyl groups, cycloalkenyl groups and other aliphatic unsaturated groups in one molecule. Those having a vinyl group are preferable, and those having a vinyl group are particularly preferable. In this case, it is preferable that 0.01 to 20 mol%, particularly 0.02 to 10 mol% of ^{the total R 1 is an aliphatic unsaturated group.} The aliphatic unsaturated group may be bonded to a silicon atom at the end of the molecular chain, to a silicon atom in the middle of the molecular chain (non-terminal of the molecular chain), or both. However, it is preferable that it is bonded to at least a silicon atom at the end of the molecular chain.
The total R ¹ in 80 mol% or more, preferably 90 mol% or more, more preferably 95 mol% or more, more preferably all of R ¹ is an alkyl group other than an aliphatic unsaturated group, especially a methyl group Is desirable.

a is a positive number of 1.95 to 2.05, preferably 1.98 to 2.02, and more preferably 1.99 to 2.01.

The molecular structure of the organopolysiloxane as the component (A) is preferably a linear structure or a linear structure having a partially branched structure. ^{Specifically, the repeating structure of the diorganosiloxane units (R 1} ₂ SiO _2/2 , R ¹ is the same as above, the same applies hereinafter) constituting the main chain of the organopolysiloxane is based on the repetition of only the dimethylsiloxane unit. Diphenylsiloxane having a phenyl group, a vinyl group, a 3,3,3-trifluoropropyl group or the like as a substituent as a part of the dimethylpolysiloxane structure composed of repeating dimethylsiloxane units constituting the main chain. It is preferable to introduce a diorganosiloxane unit such as a unit, a methylphenylsiloxane unit, a methylvinylsiloxane unit, or a methyl-3,3,3-trifluoropropylsiloxane unit.

Further, the both ends of the molecular chain, for example, trimethylsiloxy groups, dimethylphenylsiloxy groups, vinyldimethylsiloxy group, divinyl trimethylsiloxy groups, triorganosiloxy groups such as tri-siloxy group (R ¹ ₃ SiO _1/2), etc. It is preferably blocked.

Such an organopolysiloxane can be obtained, for example, by (co) hydrolyzing and condensing one or more of organohalogenosilanes, or by making cyclic polysiloxanes (trimers of siloxanes, tetramers, etc.) alkaline or It can be obtained by ring-opening polymerization using an acidic catalyst.

The degree of polymerization of the organopolysiloxane is 100 or more (usually 100 to 100,000), preferably 1,000 to 100,000, more preferably 2,000 to 50,000, and particularly preferably 3,000 to. It is preferably 20,000, so-called raw rubber (non-liquid) having no self-fluidity at room temperature (25 ° C.). If the degree of polymerization is too small, problems such as roll adhesion will occur when the compound is formed, and the roll workability will deteriorate. The degree of polymerization can be measured as a polystyrene-equivalent weight average degree of polymerization by gel permeation chromatography (GPC) analysis (hereinafter, the same).

The component (A) may be used alone or as a mixture of two or three or more having different molecular weights (degrees of polymerization) and molecular structures.

（式中、Ｒ²は脂肪族不飽和基であり、Ｒ³は同一又は異種の非置換若しくは置換の１価炭化水素基であり、ｎは１００以上の正数である。） -(B) component-
The component (B) is an organopolysiloxane having a degree of polymerization of 100 or more represented by the following formula (2). It reacts with the component (D) to form a raw rubber having a large molecular weight, and it is possible to increase the plasticity.

(In the formula, R ² is an aliphatic unsaturated group, R ³ is the same or different unsubstituted or substituted monovalent hydrocarbon group, and n is a positive number of 100 or more.)

In the above average composition formula (2), R ² is an aliphatic unsaturated group having 1 to 8 carbon atoms, and specifically, an alkenyl group such as a vinyl group, an allyl group, a propenyl group, a butenyl group or a hexenyl group, or a cyclo. It has a cycloalkenyl group such as a hexenyl group, and is particularly preferably a vinyl group.

In the above average composition formula (2), R ³ is an unsubstituted or substituted monovalent hydrocarbon group having the same or different kinds, and usually has 1 to 12 carbon atoms, particularly preferably 1 to 8 carbon atoms, and is specific. Includes alkyl groups such as methyl group, ethyl group, propyl group, butyl group, hexyl group and octyl group, cycloalkyl group such as cyclopentyl group and cyclohexyl group, alkenyl group such as vinyl group, allyl group and propenyl group, and cyclo. An aryl group such as an alkenyl group, a phenyl group or a trill group, an aralkyl group such as a benzyl group or a 2-phenylethyl group, or a halogen atom such as fluorine or chlorine or a cyano group in part or all of the hydrogen atoms of these groups. Examples thereof include a chloromethyl group, a trifluoropropyl group, a cyanoethyl group and the like substituted with, and a methyl group, a vinyl group, a phenyl group and a trifluoropropyl group are preferable, and a methyl group and a vinyl group are particularly preferable.

n indicates the degree of polymerization of (B) organopolysiloxane, which is a positive number of 100 or more, preferably 2,000 to 50,000, and more preferably 3,000 to 20,000. If n is less than 100, the plasticity may not increase.

The molecular structure of the organopolysiloxane of the component (B) is a linear structure in which one end of the molecular chain is an aliphatic unsaturated group and the other end is a silanol group. Specifically, of both ends of the molecular chain, one is ^{sealed with a diorganohydroxysiloxy group such as a dimethylhydroxysiloxy group (R 3} ₂ (HO) SiO _1/2 ), and the other is a vinyldimethylsiloxy group or divinylmethyl. It is sealed with a syroxy group and a trivinyl syroxy group. ^{Further, the repeating structure of the diorganosiloxane units (R 3} ₂ SiO _2/2 and R ³ are the same as above) constituting the main chain of the organopolysiloxane consists of repeating only the dimethylsiloxane unit, or the main body thereof. A diphenylsiloxane unit or methylphenylsiloxane unit having a phenyl group, a vinyl group, a 3,3,3-trifluoropropyl group or the like as a substituent as a part of a dimethylpolysiloxane structure composed of repeating dimethylsiloxane units constituting a chain. , Methylvinylsiloxane unit, methyl-3,3,3-trifluoropropylsiloxane unit and other diorganosiloxane units introduced are suitable.

The blending amount of the component (B) is 1 to 50 parts by mass and preferably 5 to 30 parts by mass with respect to 100 parts by mass of the organopolysiloxane of the component (A). If the amount of the component (B) is too small, the plasticity may not increase, and if it is too large, the physical properties of the cured silicone rubber may decrease.

-(C) component-
The reinforcing silica of the component (C) is a filler added to obtain a cured silicone rubber product having excellent mechanical strength, and for this purpose, the specific surface area (BET adsorption method) is 50 m ² / g. The above is necessary, ^{preferably 100 to 450 m 2} / g, and more preferably 100 to 300 m ² / g. If the specific surface area is ^{less than 50 m 2} / g, the mechanical strength of the cured product will be low.

Examples of such reinforcing silica include fuming silica (fumed silica), precipitated silica (wet silica), and the like, and the surfaces thereof are made of an organosilane compound such as methylchlorosilane, hexamethyldisilazane, and the like. Those treated with a hydrophobic treatment such as a silazane compound are also preferably used. Of these, fumes silica is preferable because it has excellent dynamic fatigue characteristics.
The component (C) may be used alone or in combination of two or more.

The blending amount of the reinforcing silica of the component (C) is 5 to 100 parts by mass, preferably 10 to 50 parts by mass with respect to 100 parts by mass of the organopolysiloxane of the component (A). If the amount of the component (C) is too small, the reinforcing effect cannot be obtained, and if it is too large, the workability is deteriorated, the mechanical strength is lowered, and the dynamic fatigue durability is also deteriorated. It ends up.

In the present invention, (C) a dispersant (wetter) of reinforcing silica can be blended as an optional component, if necessary. Examples of this wetter include a silanol group-containing (that is, a silicon atom-bonded hydroxyl group) -containing silane compound that does not contain an aliphatic unsaturated group and is distinguished from the component (B), and both ends of the molecular chain. From a silanol group-containing organosiloxane oligomer such as a linear dimethylsiloxane oligomer having a silanol group blockage (for example, a low-polymerization polymer having a degree of polymerization or the number of silicon atoms in the molecule of about 2 to 30, particularly about 3 to 20). One or more selected species are used. In the mirrorable silicone rubber composition of the present invention, when blending this wetter, the wetter is added after mixing the component (B) and the component (D) described later, or (C) reinforcing silica and the wetter are mixed in advance. It is preferable that the reaction is carried out.
The blending amount of the wetter is preferably 0 to 25 parts by mass, more preferably 3 to 20 parts by mass with respect to 100 parts by mass of the base polymer (component (A)). ..

（式中、Ｒ⁴及びＲ⁵は互いに同一又は異種の１価炭化水素基である。Ｒ⁶は２価の有機基である。） -(D) component-
The component (D) is a nitrogen atom-containing organosilicon compound, which acts on the component (B) to liberate and react with the hydroxyamino compound. Each molecule has one or more groups selected from the substituted aminoxy groups represented by the following general formulas (3) and (4) bonded to a silicon atom on average.

(In the formula, R ⁴ and R ⁵ are monovalent hydrocarbon groups that are the same as or different from each other. R ⁶ is a divalent organic group.)

In the above general formula (3), the ^{monovalent hydrocarbon groups of R 4} and R ⁵ include methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, tert-butyl group, pentyl group and hexyl group. , Octyl group, 2-ethylhexyl group, nonyl group, alkyl group such as decyl group, cycloalkyl group such as cyclohexyl group, aryl group such as phenyl group, aralkyl group such as benzyl group, etc. In particular, those having 1 to 6 carbon atoms which do not have an aliphatic unsaturated bond can be mentioned.

Further, in the above general formula (4), the ^{divalent organic group of R 6} may contain a nitrogen atom or an oxygen atom, or may have an aromatic ring in the structure 5 to 10. Examples thereof include a divalent hydrocarbon group having 3 to 10 carbon atoms, particularly a divalent hydrocarbon group having 4 to 8 carbon atoms, such as a divalent residue of a member ring, and specifically, the following divalent organic group and the like. Illustrated.

（式中、Ｒ⁷は同一又は異種の置換若しくは非置換１価炭化水素基であり、ＯＹは上記式（３）又は（４）で示される基、ｂは０、１又は２、ｃは０又は１０以下の正数である。ｌは１〜２０の正数、好ましくは１〜１０の正数であり、ｍは２〜２０の正数、好ましくは２〜１０の正数であり、且つｌ＋ｍは３以上の正数である。Ｒ’はＲ⁷又はＯＹであり、ｐ、ｑはそれぞれ独立に０又は１００以下の正数、好ましくは２〜５０の正数であり、ｑが０以上１未満の場合は２つのＲ’はＯＹであり、ｑが１以上２未満の場合はＲ’の少なくとも１つはＯＹである。Ｑは炭素数１〜２０の２価単価水素基である。） The nitrogen atom-containing organosilicon compound is represented by the following formulas (5) to (8) (for example, a sylalkylene compound such as a silane compound, a siloxane compound, or a sylethylene compound, or a sylarylene compound such as a sylphenylene compound. Etc.), and one or more selected from these is used.

(In the formula, R ⁷ is the same or different substituted or unsubstituted monovalent hydrocarbon group, OY is the group represented by the above formula (3) or (4), b is 0, 1 or 2, and c is 0. Or a positive number of 10 or less. L is a positive number of 1 to 20, preferably a positive number of 1 to 10, and m is a positive number of 2 to 20, preferably a positive number of 2 to 10. l + m is a positive number of 3 or more. R'is R ⁷ or OY, p and q are independently 0 or 100 or less positive numbers, preferably 2 to 50 positive numbers, and q is 0 or more. If it is less than 1, two R's are OY, and if q is 1 or more and less than 2, at least one of R'is OY. Q is a divalent unit-valent hydrogen group having 1 to 20 carbon atoms. )

Here ^{, examples of R 7} include those having 1 to 10 carbon atoms such as an alkyl group, an alkenyl group, a cycloalkyl group, an aryl group, an aralkyl group, a halogenated hydrocarbon group and a cyanohydrocarbon group, particularly 1 to 8. Be done. Further, as Q, a divalent hydrocarbon having 1 to 20 carbon atoms, particularly 1 to 10 carbon atoms, such as an alkylene group such as a methylene group, an ethylene group, a propylene group and a tetramethylene group, and an arylene group such as a phenylene group. The group is mentioned.

Specific examples of the component (D) include those shown below.

Since the nitrogen atom-containing organosilicon compound of the component (D) used in the composition of the present invention is a cross-linking agent that causes a cross-linking reaction with the organopolysiloxane of the component (B), the above-mentioned formulas (3) and (4) are used. ), An average of 2 or more groups selected from the substituted aminoxy groups bonded to the silicon atom in the molecule, preferably 2.05 to 10, more preferably 2.1 to 5, still more preferably 2.2. It is necessary to have about 4 pieces. When the number of aminoxic groups is less than this (that is, when a nitrogen atom-containing organosilicon compound containing the substituted aminoxic group in the molecule on an average value of less than 2 is used), the cross-linking reaction (polymerization) is insufficient. It becomes. The average value in this case means the number average value of the substituted aminoxy groups contained in one molecule of the component (D).

The component (D) is preferably 0.01 to 10 parts by mass, particularly 0.01 to 5 parts by mass, with respect to 100 parts by mass of the organopolysiloxane of the component (B).

-(E) component-
The curing agent is not particularly limited as long as it can cure the component (A), and examples thereof include the following (E-1) addition reaction curing agent and (E-2) organic peroxide curing agent.

(E-1) Addition reaction curing agent (E-1) As the addition reaction curing agent, an organohydrogenpolysiloxane and a hydrosilylation catalyst are used in combination.

As the organohydrogenpolysiloxane, hydrogen atoms bonded to 2 or more, preferably 3 or more, more preferably 3 to 200, and further preferably about 4 to 100 hydrogen atoms in one molecule (that is, SiH). As long as it contains a group), it may have a linear, cyclic, branched, or three-dimensional network structure, and a known organohydrogenpolysiloxane is used as a cross-linking agent for the addition reaction curable silicone rubber composition. For example, an organohydrogenpolysiloxane represented by the following average composition formula (9) can be used.
R ⁸ _r H _s SiO _{(4-rs) / 2} (9)

In the above average composition formula (9), R ⁸ represents an unsubstituted or substituted monovalent hydrocarbon group, which may be the same or different, and preferably excludes an aliphatic unsaturated bond. .. Usually, those having 1 to 12 carbon atoms, particularly 1 to 8 carbon atoms are preferable, and specific examples thereof include alkyl groups such as methyl group, ethyl group and propyl group, cycloalkyl groups such as cyclohexyl group, phenyl group and trill group. Alkyl groups such as aryl groups, benzyl groups, 2-phenylethyl groups and 2-phenylpropyl groups, and groups in which some or all of the hydrogen atoms of these groups are substituted with halogen atoms or the like, for example, 3,3,3. -Trifluoropropyl group and the like can be mentioned.

In addition, r, s is 0 <r <3, preferably 0.5 ≦ r ≦ 2.2, more preferably 1.0 ≦ r ≦ 2.0, 0 <s ≦ 3, preferably 0.002 ≦ s. It is a positive number satisfying ≦ 1.1, more preferably 0.005 ≦ s ≦ 1, 0 <r + s ≦ 3, preferably 1 ≦ r + s ≦ 3, and more preferably 1.002 ≦ r + s ≦ 2.7.

Organohydrogenpolysiloxane has two or more, preferably three or more SiH groups in one molecule, both at the end of the molecular chain and in the middle of the molecular chain. May be good. Further, the organohydrogenpolysiloxane preferably has a viscosity at 25 ° C. of 0.5 to 10,000 mPa · s, particularly preferably 1 to 300 mPa · s. The viscosity is a value measured by a rotational viscometer at 25 ° C. (hereinafter, the same applies).

Specific examples of such organohydrogenpolysiloxane include 1,1,3,3-tetramethyldisiloxane, 1,3,5,7-tetramethylcyclotetrasiloxane, and tris (hydrogendimethylsiloxy). ) Methylsilane, Tris (hydrogendimethylsiloxy) phenylsilane, methylhydrogencyclopolysiloxane, methylhydrogensiloxane / dimethylsiloxane cyclic copolymer, both-terminal trimethylsiloxy group blockage methylhydrogenpolysiloxane, both-terminal trimethylsiloxy group blockade Dimethylsiloxane / methylhydrogensiloxane copolymer, both-terminal dimethylhydrogensiloxy group-blocking dimethylpolysiloxane, both-terminal dimethylhydrogensiloxy group-blocking dimethylsiloxane / methylhydrogensiloxane copolymer, both-terminal trimethylsiloxy group-blocking methylhydro Gensiloxane / diphenylsiloxane copolymer, both-terminal trimethylsiloxy group-blocked methylhydrogensiloxane / diphenylsiloxane / dimethylsiloxane copolymer, both-terminal trimethylsiloxy group-blocked methylhydrogensiloxane / methylphenylsiloxane / dimethylsiloxane copolymer, Both-terminal dimethylhydrogensiloxy group-blocked methylhydrogensiloxane / dimethylsiloxane / diphenylsiloxane copolymer, both-terminal dimethylhydrogensiloxy group-blocked methylhydrogensiloxane / dimethylsiloxane / methylphenylsiloxane copolymer, (CH ₃ ) ₂ HSiO _1/2 unit and (CH ₃ ) ₃ Siloxane _1/2 unit and SiO _4/2 unit, (CH ₃ ) ₂ HSiO _1/2 unit and SiO _4/2 unit Combined, a _{copolymer consisting of (CH 3} ) ₂ HSiO _1/2 units, SiO _4/2 units and (C ₆ H ₅ ) ₃ SiO _1/2 units, etc., and some of the methyl groups in the above-exemplified compounds. Alternatively, those in which all of them are replaced with other alkyl groups, phenyl groups, or the like can be mentioned.

The blending amount of the organohydrogenpolysiloxane is preferably 0.1 to 40 parts by mass with respect to 100 parts by mass of the component (A). Further, it is appropriate that the ratio of hydrogen atoms (≡SiH groups) bonded to silicon atoms to one aliphatic unsaturated bond (alkenyl group, diene group, etc.) of component (A) is in the range of 0.5 to 10. Yes, preferably a range of 0.7 to 5 is suitable. If the number is less than 0.5, the cross-linking may not be sufficient and sufficient mechanical strength may not be obtained, and if the number exceeds 10, the physical characteristics after curing are deteriorated, and the heat resistance is particularly deteriorated. The compression set may become large.

The hydrosilylation catalyst is a catalyst in which the alkenyl group of the component (A) and the silicon atom-bonded hydrogen atom (SiH group) of the organohydrogenpolysiloxane are hydrosilylated and added. Examples of the hydrosilylation catalyst include platinum group metal-based catalysts, which include a single platinum group metal and a compound thereof, and conventionally known catalysts for addition reaction curable silicone rubber compositions can be used. For example, a platinum catalyst such as a particulate platinum metal adsorbed on a carrier such as silica gel, alumina or silica gel, a second platinum chloride, a platinum chloride acid, an alcohol solution of a hexahydrate of platinum chloride acid, a palladium catalyst, a rhodium catalyst and the like can be used. Although mentioned, platinum or a platinum compound (platinum catalyst) is preferable.

The amount of the catalyst added is only required to promote the addition reaction, and is usually used in the range of 1 mass ppm to 1 mass% in terms of the amount of platinum group metal with respect to the organopolysiloxane of the component (A). The range of ~ 500 mass ppm is preferable. If the addition amount is less than 1% by mass, the addition reaction may not be sufficiently promoted and the curing may be insufficient, while if it exceeds 1% by mass, even if a larger amount is added, the reactivity is also affected. It is small and may be uneconomical.

In addition to the above catalyst, an addition reaction control agent may be used in an amount within a range that does not impair the object of the present invention for the purpose of adjusting the curing rate. Specific examples thereof include acetylene alcohol-based control agents such as ethynylcyclohexanol, tetracyclomethylvinyl polysiloxane, and the like. The addition reaction control agent may be used alone or in combination of two or more.

(E-2) Organic Peroxide Hardener (E-2) Examples of the organic peroxide curing agent include benzoyl peroxide, 2,4-dichlorobenzoyl peroxide, p-methylbenzoyl peroxide, and o-methyl. Benzoyl peroxide, 2,4-dicumyl peroxide, 2,5-dimethyl-2,5-bis (t-butylperoxy) hexane, di-t-butyl peroxide, t-butylperbenzoate, 1,6 -Hexanediol-bis-t-butylperoxycarbonate and the like can be mentioned.

The amount of the organic peroxide added is preferably 0.1 to 10 parts by mass, particularly 0.2 to 5 parts by mass, based on 100 parts by mass of the component (A). If the amount is too small, the curing may be insufficient, and if the amount is too large, the cured silicone rubber may turn yellow due to the decomposition residue of the organic peroxide. In addition, addition reaction curing and organic peroxide curing, in which the component (E-1) and the component (E-2) were combined and blended in the above-mentioned blending amount, were used in combination with the component (A). It can also be a co-vulcanized type silicone rubber composition.

[Other ingredients]
In addition to the above components, the silicone rubber composition of the present invention contains, if necessary, a filler such as pulverized quartz, crystalline silica, diatomaceous earth, calcium carbonate, a colorant, and tear strength. Various alkoxysilanes as improvers, acid receivers, thermal conductivity improvers such as alumina and boron nitride, mold release agents, and dispersants for fillers, especially phenyl group-containing alkoxysilanes and their hydrolysates, diphenylsilanediol, and carbon. It is optional to add known fillers and additives in thermocurable silicone rubber compositions such as functional silane, silanol group-containing low molecular weight siloxanes that are distinct from component (B). Of these, when a component that reacts with component (D), such as alkoxysilane and its hydrolyzate or silanol group-containing low-molecular-weight siloxane, is added, that component is added before component (D). The component (D) may be added after reacting with a component other than the component (D), or the component (B) and the component (D) may be mixed and then added. Alternatively, the amount of the component (D) added may be increased.

The order of blending the components (A) to (E) is not particularly limited, but a method of blending the component (E) in a compound in which the components (i) (A) to (D) are mixed, or (ii) (A). ), (B), and (C) are mixed, the component (D) is added to the compound, and then the component (E) is blended. The method (ii) is preferable because the plasticity tends to increase more easily.

According to the mirrorable silicone rubber composition of the present invention, in a silicone rubber base compound containing an organopolysiloxane raw rubber (base polymer) having a degree of polymerization of 100 or more (particularly 1,000 or more) and reinforcing silica, (B) A combination of an organopolysiloxane having an aliphatic unsaturated group at one end of the molecular chain and a silanol group at the other end and a nitrogen atom-containing organic silicon compound having an average of two or more (D) aminoxy groups per molecule is added. Therefore, the plasticity can be improved as compared with the silicone rubber compound without these additions (for example, the plasticity can be improved by preferably + 5% or more, more preferably + 10% or more than the silicone rubber compound without these additions). It will be possible.

As a molding and curing method of this silicone rubber composition, a conventional method can be adopted, but as a molding method, an optimum means suitable for the purpose can be selected from injection molding, transfer molding, injection molding, compression molding and the like. It is possible. As the curing conditions, heat treatment (primary vulcanization) conditions of about 3 seconds to 160 minutes at 40 to 230 ° C. can be adopted. Further, if necessary, secondary vulcanization (post-cure) at 40 to 230 ° C. for about 10 minutes to 24 hours may be performed.

[Silicone rubber cured product]
The cured silicone rubber product according to the present invention is obtained by curing the above-mentioned millable silicone rubber composition of the present invention. At this time, the hardness (type A durometer hardness) of the cured silicone rubber of the present invention measured by the method described in JIS K 6249: 2003 is, for example, 50 or less, preferably 30 or more and 50 or less. Is.

Hereinafter, the present invention will be specifically described with reference to Examples and Comparative Examples, but the present invention is not limited to the following Examples. As the plasticity, Williams plasticity was measured according to JIS K 6249: 2003. The hardness is the hardness by a durometer A hardness tester (type A durometer hardness) measured by the method described in JIS K 6249: 2003.

[Example 1]
80 parts by mass of linear dimethylpolysiloxane raw rubber having an average degree of polymerization of about 8,000 consisting of 99.975 mol% of dimethylsiloxane unit and 0.025 mol% of dimethylvinylsiloxy unit, 90.000 mol% of dimethylsiloxane unit, 10 parts by mass of linear dimethylpolysiloxane raw rubber having an average degree of polymerization of about 8,000 consisting of 9.975 mol% of methylvinylsiloxane unit and 0.025 mol% of dimethylvinylsiloxy unit, 99.975 mol% of dimethylsiloxane unit. , 13 parts by mass of linear dimethylpolysiloxane raw rubber having an average degree of polymerization of about 8,000 consisting of 0.0125 mol% of dimethylhydroxysiloxy unit and 0.0125 mol% of dimethylvinylsiloxy unit, represented by the following formula (D1). 0.1 part by mass of the nitrogen atom-containing organic silicon compound D1 to be prepared, 25 parts by mass of fumed silica (Aerozil 200, manufactured by Nippon Aerozil Co., Ltd.) ^{having a BET method specific surface area of 200 m 2 / g, and having silanol groups at both ends.} Then, 4 parts by mass of dimethylpolysiloxane having a viscosity of 15 mPa · s at an average degree of polymerization of 4, 25 ° C. was added, and the mixture was heated at 170 ° C. for 2 hours under mixing with a kneader to prepare the base compound (1). .. The plasticity was evaluated using this compound. The results are shown in Table 1.
Methylhydrogenpolysiloxane having an average of 20 SiH groups in the side chain as a curing agent with respect to 100 parts by mass of the compound (1) (polymerization degree 38, bi-terminal trimethylsiloxy group sealing with SiH group of 0.0074 mol / g) 2 parts by mass of dimethylsiloxane / methylhydrogensiloxane copolymer), 0.05 part by mass of ethynylcyclohexanol as a reaction control agent, and 0.1 part by mass of platinum catalyst (Pt concentration 1% by mass) are added by two rolls. After uniformly mixing to produce a raw rubber-like silicone rubber composition, the composition was ^{press-cured at 120 ° C. and 70 kgf / cm 2} for 10 minutes to prepare a 2 mm-thick sheet. Then, the prepared sheet was post-cured in an oven at 200 ° C. for 4 hours, and the hardness was measured. The results are shown in Table 1.

[Example 2]
In Example 1, the base compound (2) was prepared by the same method as in Example 1 except that the amount of the nitrogen atom-containing organosilicon compound D1 was 0.2 parts by mass. The plasticity was evaluated using this compound. The results are shown in Table 1.
Methylhydrogenpolysiloxane having an average of 20 SiH groups in the side chain as a curing agent with respect to 100 parts by mass of the compound (2) (polymerization degree 38, bi-terminal trimethylsiloxy group sealing with SiH group of 0.0074 mol / g) Add 2 parts by mass of dimethylsiloxane / methylhydrogensiloxane copolymer), 0.05 part by mass of ethynylcyclohexanol as a reaction control agent, and 0.1 part by mass of platinum catalyst (Pt concentration 1% by mass) with two rolls. After uniformly mixing to produce a raw rubber-like silicone rubber composition, the composition was ^{press-cured at 120 ° C. and 70 kgf / cm 2} for 10 minutes to prepare a 2 mm-thick sheet. Then, the prepared sheet was post-cured in an oven at 200 ° C. for 4 hours, and the hardness was measured. The results are shown in Table 1.

[Example 3]
80 parts by mass of linear dimethylpolysiloxane raw rubber having an average degree of polymerization of about 8,000 consisting of 99.975 mol% of dimethylsiloxane unit and 0.025 mol% of dimethylvinylsiloxy unit, 90.000 mol% of dimethylsiloxane unit, 10 parts by mass of linear dimethylpolysiloxane raw rubber having an average degree of polymerization of about 8,000 consisting of 9.975 mol% of methylvinylsiloxane unit and 0.025 mol% of dimethylvinylsiloxy unit, 99.975 mol% of dimethylsiloxane unit. , Dimethylhydroxysiloxy unit 0.0125 mol%, dimethylvinylsiloxy unit 0.0125 mol%, linear dimethylpolysiloxane raw rubber with an average degree of polymerization of about 8,000, 13 parts by mass, BET method relative surface area 200 m ² 25 parts by mass of fumed silica (Aerozil 200, manufactured by Nippon Aerozil Co., Ltd.), 4 parts by mass of dimethylpolysiloxane having both terminal silanol groups and a viscosity of 15 mPa · s at an average degree of polymerization of 4, 25 ° C. Was added and heated at 170 ° C. for 2 hours under mixing with a kneader, and then the base compound (3) was prepared.
Next, 0.01 part by mass of the nitrogen atom-containing organosilicon compound D1 was added to 100 parts by mass of the compound (3) to prepare the base compound (4). The plasticity was evaluated using this compound. The results are shown in Table 1.
Next, with respect to 100 parts by mass of the base compound (4), methylhydrogenpolysiloxane having an average of 20 SiH groups in the side chain as a curing agent (polymerization degree 38, both ends of SiH groups 0.0074 mol / g). Two rolls of 2 parts by mass of trimethylsiloxy group-blocking dimethylsiloxane / methylhydrogensiloxane copolymer), 0.05 parts by mass of ethynylcyclohexanol as a reaction control agent, and 0.1 parts by mass of platinum catalyst (Pt concentration 1% by mass) To prepare a raw rubber-like silicone rubber composition, the composition was ^{press-cured at 120 ° C. and 70 kgf / cm 2} for 10 minutes to prepare a 2 mm-thick sheet. Then, the prepared sheet was post-cured in an oven at 200 ° C. for 4 hours, and the hardness was measured. The results are shown in Table 1.

[Comparative Example 1]
In Example 1, the nitrogen atom-containing organosilicon compound D1 was not added, and the base compound (5) was prepared by the same method as in Example 1 except that the base compound (5) was prepared in the same manner as in Example 1. The degree of plasticity and the hardness of the cured silicone rubber were measured. These results are shown in Table 1.

[Comparative Example 2]
93 parts by mass of linear dimethylpolysiloxane raw rubber having an average degree of polymerization of about 8,000 consisting of 99.975 mol% of dimethylsiloxane unit and 0.025 mol% of dimethylvinylsiloxy unit, 90.000 mol% of dimethylsiloxane unit, 10 parts by mass of linear dimethylpolysiloxane raw rubber having an average degree of polymerization of about 8,000 consisting of 9.975 mol% of methylvinylsiloxane unit and 0.025 mol% of dimethylvinylsiloxy unit, represented by the above formula (D1). It has 0.2 parts by mass of the nitrogen atom-containing organic silicon compound D1, 25 parts by mass of fumed silica (Aerozil 200, manufactured by Nippon Aerozil Co., Ltd.) with ^{a BET method specific surface area of 200 m 2 / g, and silanol groups at both ends.} , 4 parts by mass of dimethylpolysiloxane having a viscosity of 15 mPa · s at an average degree of polymerization of 4, 25 ° C. was added, and the mixture was heated at 170 ° C. for 2 hours under mixing with a kneader to prepare a base compound (6). The plasticity was evaluated using this compound. The results are shown in Table 1.
Methylhydrogenpolysiloxane having an average of 20 SiH groups in the side chain as a curing agent with respect to 100 parts by mass of the compound (6) (polymerization degree 38, bi-terminal trimethylsiloxy group sealing with SiH group of 0.0074 mol / g) Add 2 parts by mass of dimethylsiloxane / methylhydrogensiloxane copolymer), 0.05 part by mass of ethynylcyclohexanol as a reaction control agent, and 0.1 part by mass of platinum catalyst (Pt concentration 1% by mass) with two rolls. After uniformly mixing to produce a raw rubber-like silicone rubber composition, the composition was ^{press-cured at 120 ° C. and 70 kgf / cm 2} for 10 minutes to prepare a 2 mm-thick sheet. Then, the prepared sheet was post-cured in an oven at 200 ° C. for 4 hours, and the hardness was measured. The results are shown in Table 1.

[Example 4]
80 parts by mass of linear dimethylpolysiloxane raw rubber having an average degree of polymerization of about 8,000, consisting of 99.850 mol% of dimethylsiloxane unit, 0.125 mol% of methylvinylsiloxane unit, and 0.025 mol% of dimethylvinylsiloxy unit. , Dimethylsiloxane unit 99.975 mol%, dimethylhydroxysiloxy unit 0.0125 mol%, dimethylvinylsiloxy unit 0.0125 mol%, and 20 masses of linear dimethylpolysiloxane raw rubber having an average degree of polymerization of about 8,000. 50 parts by mass of a nitrogen atom-containing organic silicon compound D2 represented by the following formula (D2) and a BET method specific surface area of 200 m ² / g fumed silica (Aerosil R974, manufactured by Nippon Aerosil Co., Ltd.) 30 The base compound (7) was prepared after adding parts by mass and heating at 170 ° C. for 2 hours under mixing with a kneader. The plasticity was evaluated using this compound. The results are shown in Table 2.
To 100 parts by mass of the compound (7), 0.4 parts by mass of 2,5-dimethyl-2,5-bis (t-butylperoxy) hexane was added as a curing agent by two rolls to make it uniform. After mixing to produce a raw rubber-like silicone rubber composition, the composition was ^{press-cured at 165 ° C. and 70 kgf / cm 2} for 10 minutes to prepare a sheet having a thickness of 2 mm. Then, the prepared sheet was post-cured in an oven at 200 ° C. for 4 hours, and the hardness was measured. The results are shown in Table 2.

[Example 5]
In Example 4, the base compound (8) was prepared by the same method as in Example 4 except that the nitrogen atom-containing organosilicon compound D2 was made up to 0.16 parts by mass. The plasticity was evaluated using this compound. The results are shown in Table 2.
To 100 parts by mass of the compound (8), 0.4 parts by mass of 2,5-dimethyl-2,5-bis (t-butylperoxy) hexane was added as a curing agent by two rolls to make it uniform. After mixing to produce a raw rubber-like silicone rubber composition, the composition was ^{press-cured at 165 ° C. and 70 kgf / cm 2} for 10 minutes to prepare a sheet having a thickness of 2 mm. Then, the prepared sheet was post-cured in an oven at 200 ° C. for 4 hours, and the hardness was measured. The results are shown in Table 2.

[Example 6]
80 parts by mass of linear dimethylpolysiloxane raw rubber having an average degree of polymerization of about 8,000, consisting of 99.850 mol% of dimethylsiloxane unit, 0.125 mol% of methylvinylsiloxane unit, and 0.025 mol% of dimethylvinylsiloxy unit. 20 mass of linear dimethylpolysiloxane raw rubber having an average degree of polymerization of about 8,000, consisting of 99.975 mol% of dimethylsiloxane unit, 0.0125 mol% of dimethylhydroxysiloxy unit, and 0.0125 mol% of dimethylvinylsiloxy unit. Part, BET method 30 parts by mass of fumed silica (Aerosil R974, manufactured by Nippon Aerosil Co., Ltd.) having a specific surface area of 200 m ² / g was added, heated at 170 ° C. for 2 hours under mixing with a kneader, and then the base compound. (9) was prepared.
Next, 0.01 part by mass of the nitrogen atom-containing organosilicon compound D2 was added to 100 parts by mass of the compound (9) to prepare the base compound (10). The plasticity was evaluated using this compound. The results are shown in Table 2.
Next, 0.4 parts by mass of 2,5-dimethyl-2,5-bis (t-butylperoxy) hexane was added as a curing agent to 100 parts by mass of the compound (10) in two rolls. After producing a raw rubber-like silicone rubber composition by uniformly mixing, the composition was ^{press-cured at 165 ° C. and 70 kgf / cm 2} for 10 minutes to prepare a sheet having a thickness of 2 mm. Then, the prepared sheet was post-cured in an oven at 200 ° C. for 4 hours, and the hardness was measured. The results are shown in Table 2.

[Comparative Example 3]
In Example 4, the nitrogen atom-containing organosilicon compound D2 was not added, and the base compound (11) was prepared by the same method as in Example 4 except that the base compound (11) was prepared in the same manner as in Example 4. The degree of plasticity and the hardness of the cured silicone rubber were measured. These results are shown in Table 2.

Claims (5)

(A) The following average composition formula (1)
R ¹ _a SiO _{(4-a) / 2} (1)
(In the formula, R ¹ is the same or different unsubstituted or substituted monovalent hydrocarbon group, and a is a positive number of 1.95 to 2.05.)
100 parts by mass of organopolysiloxane having a degree of polymerization of 100 or more, represented by
(B) The following formula (2)

(In the formula, R ² is an aliphatic unsaturated group, R ³ is the same or different unsubstituted or substituted monovalent hydrocarbon group, and n is a positive number of 100 or more.)
Organopolysiloxane represented by 1 to 50 parts by mass,
(C) Reinforcing silica with a specific surface area of 50 m ² / g or more by the BET adsorption method
5 to 100 parts by mass,
(D) A nitrogen atom-containing organosilicon compound having one or more groups selected from the substituted aminoxy groups represented by the following formulas (3) and (4) bonded to a silicon atom on average at least two per molecule. 0.001 to 15 parts by mass,

(In the formula, R ⁴ and R ⁵ are monovalent hydrocarbon groups that are the same as or different from each other. R ⁶ is a divalent organic group.)
(E) A miraculous silicone rubber composition containing an effective amount of a curing agent. The miraculous silicone rubber composition according to claim 1, wherein the component (D) is one or more selected from the organosilicon compounds represented by the following formulas (5) to (8).

(In the formula, R ⁷ is the same or different substituted or unsubstituted monovalent hydrocarbon group, OY is the group represented by the above formula (3) or (4), b is 0, 1 or 2, and c is 0. Or a positive number of 10 or less. L is a positive number of 1 to 20, m is a positive number of 2 to 20, and l + m is a positive number of 3 or more. R'is R ⁷ or OY. p and q are independently positive numbers of 0 or 100, respectively. When q is 0 or more and less than 1, two R'are OY, and when q is 1 or more and less than 2, at least one of R'. Is OY. Q is a divalent hydrocarbon group having 1 to 20 carbon atoms.) The miraculous silicone rubber composition according to claim 1 or 2, wherein the curing agent for the component (E) is an addition reaction curing type comprising a combination of an organohydrogenpolysiloxane and a hydrosilylation catalyst. The miraculous silicone rubber composition according to claim 1 or 2, wherein the curing agent of the component (E) is an organic peroxide. A silicone rubber cured product obtained by curing the miraculous silicone rubber composition according to any one of claims 1 to 4.