JP2012211232A - Silicone rubber-based curing composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a silicone rubber-based curing composition exhibiting high strength and stable physical properties as a silicone rubber-based curing composition for a medical device material.SOLUTION: Use of a first mixed component containing a crosslinking agent and a vinyl group-containing linear organopolysiloxane improves production economy, and can provide the silicone rubber-based curing composition exhibiting excellent mechanical strength such as tensile strength and tear strength, and stable mechanical strength as a medical device material.

Description

  The present invention relates to a silicone rubber-based curable composition using a first mixed component containing a crosslinking agent and a vinyl group-containing linear organopolysiloxane.

In general, most of the rubber chemicals are finely powdered or liquid, so that the accuracy of chemical injection may be deteriorated due to scattering or adhesion, or the skin adheres to the worker and stimulates or inhales the skin. It is not preferable for hygiene. In addition, when mixing liquid chemicals having vastly different viscosities, the accuracy of the chemicals is deteriorated, and it is not preferable from the viewpoint of workability and work time. That is, the economic efficiency during production deteriorates. Therefore, in the rubber product manufacturing industry, a so-called master batch method is employed in which rubber chemicals are kneaded in advance and predispersed in rubber. This product not only has no scattering property, but also has excellent dispersibility in rubber, and can be easily mixed between master batches and compounded in rubber.

  On the other hand, silicone rubber is excellent in heat resistance, flame retardancy, chemical stability, weather resistance, radiation resistance, electrical properties, and the like, and thus is used for various applications in a wide range of fields. In particular, silicone rubber is physiologically inactive and has little reaction to body tissue when touched by a living body. Therefore, silicone rubber is also used as a material for medical instruments such as various medical catheters.

Silicone rubber is excellent in terms of biocompatibility and flexibility as a medical device material, but it is required to improve strength such as tear strength and tensile strength, particularly tear strength. Furthermore, as a medical device material, it is a silicone rubber excellent in strength and yet requires stable physical properties.

Various methods have been proposed to increase the tear strength and tensile strength of silicone rubber. For example, in Patent Document 1, an organopolysiloxane having a high viscosity and a low vinyl group content (raw rubber (A)) is mainly used, and an organopolysiloxane having a low viscosity and a high vinyl group content (silicone oil (B)). ), Vinyl group-containing organopolysiloxane copolymer (vinyl group-containing silicone resin (C)), organohydrogensiloxane (crosslinking agent (D)), platinum or platinum compound (curing catalyst (E)), and finely divided silica ( A curable silicone rubber composition containing a filler (F)) is disclosed.
However, the prior literature does not describe the merit of masterbatch and the stability of strength, and a silicone rubber-based curable composition exhibiting high strength and stable physical properties is required as a medical material.

JP 7-331079 A Japanese Patent Laid-Open No. 7-228782 JP-A-7-258551

An object of the present invention is to provide a silicone rubber-based cured composition that exhibits high strength and stable physical properties as a silicone rubber-based cured composition for medical device materials.

（式（１）中、ｍは１〜１０００の整数、ｎは３０００〜１００００の整数であり、Ｒ^１は炭素数１〜１０の置換又は非置換のアルキル基、アルケニル基、アリール基、又はこれらを組み合わせた炭化水素基、Ｒ^２は炭素数１〜１０の置換又は非置換のアルキル基、アルケニル基、アリール基、又はこれらを組み合わせた炭化水素基、Ｒ^３は炭素数１〜８の置換又は非置換のアルキル基、アリール基、又はこれらを組み合わせた炭化水素基であり、複数あるＲ^１及びＲ^２の少なくとも１つ以上がアルケニル基である。）
（５） 前記直鎖状オルガノハイドロジェンポリシロキサン（Ｂ）は、下記式（２）で示されるものである（２）または（３）に記載のシリコーンゴム系硬化性組成物。

（式（２）中、ｍは０〜３００の整数、ｎは（３００−ｍ）の整数である。Ｒ^４は炭素数１〜１０の置換又は非置換のアルキル基、アルケニル基、アリール基、これらを組み合わせた炭化水素基、又はヒドリド基である。Ｒ^５は炭素数１〜１０の置換又は非置換のアルキル基、アルケニル基、アリール基、これらを組み合わせた炭化水素基、又はヒドリド基である。ただし、Ｒ^４及びＲ^５のうち、少なくとも２つ以上がヒドリド基である。Ｒ^６は炭素数１〜８の置換又は非置換のアルキル基、アリール基、又はこれらを組み合わせた炭化水素基である。）
（６）前記第１混合成分は、ビニル基含有直鎖状オルガノポリシロキサン（Ａ）１００重量部に対し、無機ケイ素フィラー（Ｃ）を０〜１５０重量部含む、（３）記載のシリコーンゴム系硬化性樹脂組成物。
（７） 前記無機ケイ素フィラー（Ｃ）は、疎水性官能基を少なくとも一種含む、（３）または（６）記載のシリコーンゴム系硬化性樹脂組成物。
（８）前記表面に疎水性官能基を有する無機ケイ素フィラー（Ｃ）は、比表面積が３０〜５００ｍ^２／ｇ、平均１次粒子径が１００ｎｍ以下である、（３）、（６）、（７）のいずれか１項に記載のシリコーンゴム系硬化性樹脂組成物。
（９）（１）ないし（８）のいずれか１項に記載の第１混合成分と、触媒（Ｄ）とビニル基含有直鎖状オルガノポリシロキサン（Ａ）とを含む第２混合成分とを用いるシリコーンゴム系硬化性樹脂組成物。
（１０）前記第２混合成分は、（４）記載のビニル基含有直鎖状オルガノポリシロキサン（Ａ）と、触媒（Ｄ）と、を含む（９）記載のシリコーンゴム系硬化性樹脂組成物。
（１１）前記第２混合成分は、（４）記載のビニル基含有直鎖状オルガノポリシロキサン（Ａ）と、（８）記載の無機ケイ素フィラー（Ｃ）と、触媒（Ｄ）と、を含む（９）記載のシリコーンゴム系硬化性樹脂組成物。
（１２）前記第２混合成分は、ビニル基含有直鎖状オルガノポリシロキサン（Ａ）１００重量部に対し、無機ケイ素フィラー（Ｃ）を０〜１５０重量部含む、（９）ないし（１１）のいずれか１項に記載のシリコーンゴム系硬化性樹脂組成物。
（１３）前記触媒が白金化合物である（９）ないし（１２）のいずれか１項に記載のシリコーンゴム系硬化性樹脂組成物。 Such an object is achieved by the present invention described in the following (1) to (13).
(1) A silicone rubber-based curable resin composition comprising a first mixed component containing a crosslinking agent and a vinyl group-containing linear organopolysiloxane (A).
(2) The silicone rubber-based curable resin composition according to (1), wherein the second crosslinking agent is a linear organohydrogenpolysiloxane (B).
(3) The first mixed component includes a vinyl group-containing linear organopolysiloxane (A), a linear organohydrogenpolysiloxane (B), and an inorganic silicon filler having a hydrophobic functional group on the surface (C And the silicone rubber-based curable resin composition according to (1) or (2).
(4) The silicone rubber-based curable composition according to any one of (1) to (3), wherein the vinyl group-containing linear organopolysiloxane (A) is represented by the following formula (1): object.

(In the formula (1), m is an integer, n represents an integer of 3000 to 10000 of 1 to 1000, ^{R 1} is a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, an alkenyl group, an aryl group, or their R ² is a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, an alkenyl group, an aryl group, or a hydrocarbon group combining these, R ³ is a substituted or unsubstituted group having 1 to 8 carbon atoms An unsubstituted alkyl group, an aryl group, or a hydrocarbon group that is a combination thereof, and at least one of a plurality of R ¹ and R ² is an alkenyl group.)
(5) The silicone rubber-based curable composition according to (2) or (3), wherein the linear organohydrogenpolysiloxane (B) is represented by the following formula (2).

(In Formula (2), m is an integer of 0-300, n is an integer of (300-m). R ⁴ is a substituted or unsubstituted alkyl group, alkenyl group, aryl group having 1 to 10 carbon atoms, R ⁵ is a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, an alkenyl group, an aryl group, a combined hydrocarbon group, or a hydride group. However, at least two of R ⁴ and R ⁵ are hydride groups, and R ⁶ is a substituted or unsubstituted alkyl group having 1 to 8 carbon atoms, an aryl group, or a hydrocarbon group that is a combination thereof. is there.)
(6) The silicone rubber system according to (3), wherein the first mixed component contains 0 to 150 parts by weight of an inorganic silicon filler (C) with respect to 100 parts by weight of the vinyl group-containing linear organopolysiloxane (A). Curable resin composition.
(7) The silicone rubber-based curable resin composition according to (3) or (6), wherein the inorganic silicon filler (C) includes at least one hydrophobic functional group.
(8) The inorganic silicon filler (C) having a hydrophobic functional group on the surface has a specific surface area of 30 to 500 m ² / g and an average primary particle size of 100 nm or less, (3), (6), ( The silicone rubber-based curable resin composition according to any one of 7).
(9) The first mixed component according to any one of (1) to (8), and the second mixed component containing the catalyst (D) and the vinyl group-containing linear organopolysiloxane (A). Silicone rubber-based curable resin composition to be used.
(10) The silicone rubber-based curable resin composition according to (9), wherein the second mixed component includes the vinyl group-containing linear organopolysiloxane (A) according to (4) and a catalyst (D). .
(11) The second mixed component includes a vinyl group-containing linear organopolysiloxane (A) described in (4), an inorganic silicon filler (C) described in (8), and a catalyst (D). (9) The silicone rubber-based curable resin composition according to (9).
(12) The second mixed component contains 0 to 150 parts by weight of the inorganic silicon filler (C) with respect to 100 parts by weight of the vinyl group-containing linear organopolysiloxane (A), (9) to (11) The silicone rubber-based curable resin composition according to any one of the above.
(13) The silicone rubber curable resin composition according to any one of (9) to (12), wherein the catalyst is a platinum compound.

  The present invention is characterized by excellent mechanical strength such as tensile strength and tear strength and stable mechanical strength by using a first mixed component containing a crosslinking agent and a vinyl group-containing linear organopolysiloxane. In addition, a silicone rubber-based curable composition with improved production economics could be provided.

Hereinafter, the silicone rubber-based curable composition of the present invention will be described in detail. The silicone rubber-based curable composition of the present invention is provided using a first mixed component containing a crosslinking agent and a vinyl group-containing linear organopolysiloxane.

  The first mixed component of the present application is characterized in that a linear organohydrogenpolysiloxane (B) used as a crosslinking agent in at least a vinyl group-containing linear organopolysiloxane (A) is kneaded in advance, usually a master What is called a batch.

First, the vinyl group-containing linear organopolysiloxane (A) constituting the first mixed component will be described.
(A) Vinyl group-containing linear organopolysiloxane Vinyl group-containing linear organopolysiloxane (A) is the main component of the silicone rubber-based curable composition of the present invention and is a polymer having a linear structure. is there. It contains a vinyl group, and the vinyl group serves as a crosslinking point during vulcanization.

  The vinyl group content of the vinyl group-containing linear organopolysiloxane (A) is not particularly limited, but is preferably 0.01 to 15 mol%, more preferably 0.05 to 12 mol%. Here, the vinyl group content is the mol% of the vinyl group-containing siloxane unit when the total unit constituting the vinyl group-containing linear organopolysiloxane (A) is 100 mol%. However, one vinyl group is considered for one vinyl group-containing siloxane unit.

The degree of polymerization of the vinyl group-containing linear organopolysiloxane (A) is not particularly limited, but is usually in the range of 3000 to 10000, preferably in the range of 4000 to 8000.
The specific gravity of the vinyl group-containing linear organopolysiloxane (A) is usually in the range of 0.9 to 1.1.
When it is lower than 3000, the viscosity becomes low, and the handleability decreases. Moreover, since it becomes high viscosity when it exceeds 10,000, a handleability falls.
By using a vinyl group-containing linear organopolysiloxane (A) having a polymerization degree and specific gravity within the above ranges, the resulting silicone rubber has heat resistance, flame retardancy, chemical stability, etc. Can be improved.

  As the vinyl group-containing linear organopolysiloxane (A), those having a structure represented by the following formula (1) are preferable.

(In the formula (1), m is an integer, n represents an integer of 3000 to 10000 of 1 to 1000, ^{R 1} is a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, an alkenyl group, an aryl group, or their R ² is a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, an alkenyl group, an aryl group, or a hydrocarbon group combining these, R ³ is a substituted or unsubstituted group having 1 to 8 carbon atoms (It is an unsubstituted alkyl group, an aryl group, or a hydrocarbon group obtained by combining these, and at least one of the plurality of R ¹ and R ² is an alkenyl group.)

In Formula (1), R ¹ is a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, an alkenyl group, an aryl group, or a hydrocarbon group obtained by combining these. As a C1-C10 alkyl group, a methyl group, an ethyl group, a propyl group etc. are mentioned, for example, Among these, a methyl group is preferable. As a C1-C10 alkenyl group, a vinyl group, an allyl group, a butenyl group etc. are mentioned, for example, Among these, a vinyl group is preferable. Examples of the aryl group having 1 to 10 carbon atoms include a phenyl group.

R ² is a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, an alkenyl group, an aryl group, or a hydrocarbon group obtained by combining these. As a C1-C10 alkyl group, a methyl group, an ethyl group, a propyl group etc. are mentioned, for example, Among these, a methyl group is preferable. Examples of the alkenyl group having 1 to 10 carbon atoms include a vinyl group, an allyl group, and a butenyl group. Examples of the aryl group having 1 to 10 carbon atoms include a phenyl group.

R ³ is a substituted or unsubstituted alkyl group having 1 to 8 carbon atoms, an aryl group, or a hydrocarbon group obtained by combining these. As a C1-C8 alkyl group, a methyl group, an ethyl group, a propyl group etc. are mentioned, for example, Among these, a methyl group is preferable. Examples of the aryl group having 1 to 8 carbon atoms include a phenyl group.

Examples of the substituent for R ¹ and R ² in the formula (1) include a methyl group and a vinyl group, and examples of the substituent for R ³ include a methyl group.
In the formula (1), a plurality of R ¹ are independent from each other and may be different from each other or the same. The same applies to R ² and R ³ .
However, at least one of the plurality of R ¹ and R ² has a vinyl group, that is, at least one of the plurality of R ¹ and R ² is an alkenyl group.

m and n are the number of repeating units constituting the vinyl group-containing linear organopolysiloxane (A) represented by the formula (1), m is an integer of 1 to 1000, and n is an integer of 3000 to 10,000. It is. m is preferably 40 to 700, and n is preferably 3600 to 8000.
Specific examples of the vinyl group-containing linear organopolysiloxane (A) represented by the formula (1) include those represented by the following formula (1-1).

In formula (1-1), R ¹ and R ² are each independently a methyl group or a vinyl group, and at least one is a vinyl group.

In the present invention, in order to increase the tear strength of the silicone rubber, it is preferable to use two types of (A) vinyl group-containing linear organopolysiloxanes having different vinyl group contents. That is, by combining a first vinyl group-containing linear organopolysiloxane having a general vinyl group content and a second vinyl group-containing linear organopolysiloxane having a high vinyl group content, By making the vinyl groups unevenly distributed and effectively forming a crosslink density in the crosslinked network of silicone rubber, the tear strength can be increased. Hereinafter, the first vinyl group-containing linear organopolysiloxane is described as (A1), and the second vinyl group-containing linear organopolysiloxane silicone rubber is described as (A2). For example, a first vinyl group-containing linear organopolysiloxane (A1) having a vinyl group content of 0.05 to 0.2 mol% and a vinyl group content of 0.5 to 12 mol%. 2 vinyl group-containing linear organopolysiloxane. Specifically, as the vinyl group-containing linear organopolysiloxane (A), for example, in the above formula (1-1), R ¹ is a vinyl group and / or R ² is a vinyl group. 0.05 to 0.2 mol% of the first vinyl group-containing linear organopolysiloxane (A1), R ¹ is a vinyl group and / or R ² is a vinyl group. It is preferable to use the second vinyl group-containing linear organopolysiloxane (A2) containing 5 to 12 mol%.

The first vinyl group-containing linear organopolysiloxane (A1) preferably has a vinyl group content of 0.1 to 0.15 mol%. The second vinyl group-containing linear organopolysiloxane (A2) preferably has a vinyl group content of 0.8 to 8.0 mol%.
When the first vinyl group-containing linear organopolysiloxane (A1) and the second vinyl group-containing linear organopolysiloxane (A2) are combined in combination, the ratio of (A1) and (A2) is particularly Although it is not limited, it is preferable that A1: A2 is usually 1: 0.05 to 1: 0.6, particularly 1: 0.08 to 1: 0.5 by weight ratio.
Each of the first and second vinyl group-containing linear organopolysiloxanes (A1) and (A2) may be used alone or in combination of two or more.

Next, the linear organohydrogenpolysiloxane that is the crosslinking agent of the first mixed component will be described.

(B) Linear organohydrogenpolysiloxane The linear organohydrogenpolysiloxane (B) has a linear structure and a structure in which hydrogen is directly bonded to Si (≡Si—H). In addition to the vinyl group of the vinyl group-containing linear organopolysiloxane (A), the vinyl group of the component blended in the silicone rubber-based curable composition undergoes a hydrosilylation reaction to crosslink these components.

In the linear organohydrogenpolysiloxane (B), the amount of hydrogen atoms (hydride groups) directly bonded to Si is not particularly limited. In the silicone rubber-based curable composition, the amount of hydride groups of the linear organohydrogenpolysiloxane (B) is 0.5 with respect to 1 mol of vinyl groups in the vinyl group-containing linear organopolysiloxane (A). An amount of ˜5 mol is preferred, and an amount of 1˜3.5 mol is more preferred.
The molecular weight of the linear organohydrogenpolysiloxane (B) is not particularly limited, but the weight average molecular weight is preferably 20000 or less, and the weight average molecular weight is particularly preferably 7000 or less. The weight average molecular weight of the linear organohydrogenpolysiloxane (B) can be measured by GPC (gel permeation chromatography).

  Usually, the linear organohydrogenpolysiloxane (B) preferably has no vinyl group. This is because the intramolecular crosslinking reaction may proceed.

  As linear organohydrogenpolysiloxane (B), what has a structure represented by following formula (2) is preferable.

(In Formula (2), m is an integer of 0-300, n is an integer of (300-m). R ⁴ is a substituted or unsubstituted alkyl group, alkenyl group, aryl group having 1 to 10 carbon atoms, R ⁵ is a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, an alkenyl group, an aryl group, a combined hydrocarbon group, or a hydride group. However, at least two of the plurality of R ⁴ and R ⁵ are hydride groups, and R ⁶ is a substituted or unsubstituted alkyl group having 1 to 8 carbon atoms, an aryl group, or a hydrocarbon obtained by combining these. Group.)

In the formula (2), R ⁴ is a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, an alkenyl group, an aryl group, a hydrocarbon group combining these, or a hydride group. As a C1-C10 alkyl group, a methyl group, an ethyl group, a propyl group etc. are mentioned, for example, Among these, a methyl group is preferable. As a C1-C10 alkenyl group, a vinyl group, an allyl group, a butenyl group etc. are mentioned, for example, Among these, a vinyl group is preferable. Examples of the aryl group having 1 to 10 carbon atoms include a phenyl group.

R ⁵ is a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, an alkenyl group, an aryl group, a hydrocarbon group combining these, or a hydride group. Examples of the alkyl group having 1 to 10 carbon atoms include a methyl group, an ethyl group, and a propyl group, and among them, a methyl group is preferable. As a C1-C10 alkenyl group, a vinyl group, an allyl group, a butenyl group etc. are mentioned, for example, Among these, a vinyl group is preferable. Examples of the aryl group having 1 to 10 carbon atoms include a phenyl group.

In the formula (2), the plurality of R ⁴ are independent from each other and may be different from each other or the same. The same is true for R ^5. However, at least two of the plurality of R ⁴ and R ⁵ are hydride groups.

R ⁶ is a substituted or unsubstituted alkyl group having 1 to 8 carbon atoms, an aryl group, or a hydrocarbon group obtained by combining these. As a C1-C8 alkyl group, a methyl group, an ethyl group, a propyl group etc. are mentioned, for example, Among these, a methyl group is preferable. Examples of the aryl group having 1 to 8 carbon atoms include a phenyl group. The plurality of R ⁶ are independent from each other and may be different from each other or the same.

Examples of the substituent for R ⁴ , R ⁵ , and R ^{6 in} the formula (1) include a methyl group and a vinyl group, and a methyl group is preferable from the viewpoint of preventing an intramolecular crosslinking reaction.

  m and n are the number of repeating units constituting the linear organohydrogenpolysiloxane (B) represented by the formula (2), m is an integer of 0 to 300, and n is (300-m). It is an integer. Preferably, m is an integer of 0 to 150, and n is an integer of (150-m).

  (B) One type of linear organohydrogenpolysiloxane may be used alone, or two or more types may be used in combination.

  In order to suppress the viscosity of the first mixed component, an inorganic silicon filler silica filler (C) having a hydrophobic functional group on the surface [hereinafter sometimes simply referred to as silica filler (C)] is added to the first mixed component. May be. The silica filler (C) is 0 to 150 parts by weight, preferably 20 to 100 parts by weight, more preferably 35 to 80 parts by weight, most preferably 100 parts by weight of the vinyl group-containing linear organopolysiloxane (A). Is 45 to 75 parts by weight. When the silica filler (C) exceeds 150 parts by weight, the first mixed component becomes extremely hard, workability is poor, and it is difficult to obtain a uniform first mixed component.

The silica filler (C) has a hydrophobic functional group and is obtained by surface treatment with a silane coupling agent. The surface may be treated in advance using a silane coupling agent, or the surface may be treated in the process of producing the silicone curable composition. That is, the surface treatment is not particularly limited, but the treatment of the surface in the process of producing the silicone curable composition may be excellent in terms of cost such as material cost and production economy.

  In the silica filler (C), all hydroxyl groups of silanol groups present on the surface of the silica filler are substituted with at least one hydrophobic functional group-containing functional group derived from at least one hydrophobic functional group-containing silane coupling agent. It is preferred that

  Examples of the silica filler to be surface-treated include dry silica and wet silica. Among them, dry silica is preferable from the viewpoint of extrusion molding property and workability of silicone rubber, and fumed silica is particularly preferable.

In the silica filler (C), the hydroxyl group of the silanol group present on the surface of the silica filler is substituted with at least one hydrophobic functional group-containing functional group derived from at least one hydrophobic functional group-containing silane coupling agent. It is preferable.
In the present invention, the silane coupling agent has a hydrolyzable group, and reacts with a hydroxyl group provided on the surface of the silica filler (C), thereby performing surface treatment of the silica filler (C).

By imparting this hydrophobic group to the surface of the silica filler (C) with this silane coupling agent, the dispersibility of the silica filler (C) in the silicone rubber-based curable composition and thus in the silicone rubber is improved. Can do. As a result, the uniformity of strength (particularly, tensile strength and tear strength) in the silicone rubber and improvement of strength are achieved.
Further, it is preferable to use a silane coupling agent having a vinyl group or a silane coupling agent having a vinyl group. Thereby, a vinyl group is introduced into the surface of the silica filler (C). Therefore, when the silicone rubber-based curable composition is cured, that is, the vinyl group that the vinyl group-containing linear organopolysiloxane (A) has, and the hydride group that the linear organohydrogenpolysiloxane (B) has When the hydrosilylation reaction forms a network (crosslinked structure), the vinyl group of the silica filler (C) is also hydrosilylated with the hydride group of the linear organohydrogenpolysiloxane (B). Since it is involved in the crystallization reaction, the silica filler (C) is also taken into the network. Thereby, it is possible to increase the hardness and modulus of the formed silicone rubber.

Ｙ_ｎ−Ｓｉ−（ＯＲ）_４−ｎ ・・・ （３）

上記式（３）中、ｎは１〜３の整数を表わす。Ｙは、疎水性基、親水性基またはビニル基を有するもののうちのいずれかの官能基を表わし、ｎが１の時は疎水性基であり、ｎが２または３の時はその少なくとも１つが疎水性基である。ＯＲは、加水分解性基を表わす。
疎水性基は、炭素数１〜６のアルキル基、アリール基、またはこれらを組み合わせた炭化水素基であり、例えば、メチル基、エチル基、プロピル基、フェニル基等が挙げられ、中でも、特に、メチル基が好ましい。 As such a silane coupling agent, what is represented by following formula (3) is mentioned, for example.

Y _n —Si— (OR) _4-n (3)

In said formula (3), n represents the integer of 1-3. Y represents a functional group of any one having a hydrophobic group, a hydrophilic group or a vinyl group. When n is 1, it is a hydrophobic group, and when n is 2 or 3, at least one of them is a hydrophobic group. It is a hydrophobic group. OR represents a hydrolyzable group.
The hydrophobic group is an alkyl group having 1 to 6 carbon atoms, an aryl group, or a hydrocarbon group that is a combination thereof, and examples thereof include a methyl group, an ethyl group, a propyl group, and a phenyl group. A methyl group is preferred.

  Examples of the hydrophilic group include a hydroxyl group, a sulfonic acid group, a carboxyl group, and a carbonyl group. Among these, a hydroxyl group is particularly preferable. The hydrophilic group may be included as a functional group, but is preferably not included from the viewpoint of imparting hydrophobicity to the silane coupling agent (D).

Furthermore, examples of the hydrolyzable group include an alkoxy group such as a methoxy group and an ethoxy group, a chloro group, and a silazane group. Among them, a silazane group is preferable because of its high reactivity with the silica filler (C). Incidentally, those having a silazane group as hydrolyzable groups, the characteristics of its structure the formula (3) in the structure of (Y _n -Si-) comes to have two.

  Examples of the silane coupling agent (D) represented by the above formula (3) include those having a hydrophobic group as a functional group such as methyltrimethoxysilane, dimethyldimethoxysilane, phenyltrimethoxysilane, and methyltriethoxysilane. Alkoxysilanes such as dimethyldiethoxysilane, phenyltriethoxysilane, n-propyltrimethoxysilane, n-propyltriethoxysilane, hexyltrimethoxysilane, hexyltriethoxysilane, decyltrimethoxysilane; methyltrichlorosilane, dimethyl Chlorosilanes such as dichlorosilane, trimethylchlorosilane, phenyltrichlorosilane; hexamethyldisilazane, and methacryloxypropyltriethoxysila having a vinyl group as a functional group , Alkoxysilanes such as methacryloxypropyltrimethoxysilane, methacryloxypropylmethyldiethoxysilane, methacryloxypropylmethyldimethoxysilane, vinyltriethoxysilane, vinyltrimethoxysilane, vinylmethyldimethoxysilane; vinyltrichlorosilane, vinylmethyldi Examples include chlorosilanes such as chlorosilane; divinyltetramethyldisilazane. Among these, in view of the above description, hexamethyldisilazane having a hydrophobic group and divinyltetramethyldisilazane having a vinyl group are particularly preferable. Silazane is preferred.

When the surface of silica filler (C) is treated in the process of producing a silicone curable composition, the surface treatment process and the surface treatment method are not limited. For example, vinyl group-containing linear organopolysiloxane (A The surface can be treated by reaction by adding both the silane coupling agent and the silica filler (C) and mixing in rubber.
Moreover, when surface-treating with a silane coupling agent in the process of producing the silicone curable composition, water may be contained.
Water is a component that contributes to the reaction between the silica filler (C) and the silane coupling agent while functioning as a dispersion medium for dispersing each component contained in the silicone rubber-based curable composition.

  When using a silica filler (C) whose surface has been previously treated with a silane coupling agent, for example, the surface treatment of the silica filler with a trimethylsilyl group-containing silane coupling agent is not particularly limited. The method described in 2007-526373 can be adopted.

  Specifically, water is first sprayed on a silica filler that has not been surface-treated with a trimethylsilyl group-containing silane coupling agent (untreated silica filler), followed by a trimethylsilyl group-containing silane coupling agent, and then heat treatment. The method of doing is mentioned. Here, water acidified with an acid such as hydrochloric acid (for example, pH 1 to 7) may be used. The silane coupling agent may be dissolved in an appropriate solvent and sprayed as necessary. Spraying water or a silane coupling agent can be performed using, for example, a one-fluid nozzle, a two-fluid nozzle, an ultrasonic nozzle, or the like. The spraying is preferably carried out while stirring the silica filler in a container having a mixing means. After spraying water or a silane coupling agent, a silica filler and water and / or a silane coupling agent may be mixed as necessary. Although the temperature and time of heat processing can be set suitably, for example, it can heat at 20-400 degreeC for 0.1 to 6 hours. The heat treatment can also be performed in an inert atmosphere such as a nitrogen gas atmosphere.

  Or the method of exposing an untreated silica filler to the vapor | steam of a silane coupling agent, and then heating (for example, 50-800 degreeC) is mentioned. The heat treatment can also be performed in an inert atmosphere.

The silica filler (C) has a specific surface area of 30 m ² / g or more, particularly preferably 100 m ² / g or more, and preferably 500 m ² / g or less, particularly preferably 300 m ² / g or less. The specific surface area is particularly preferably in the range of 30 to 500 m ² / g.

Silica filler (C) is a component that improves the hardness and mechanical strength of the silicone rubber to be formed, especially the tensile strength. The function as the filler (C) can be remarkably exhibited. When the specific surface area is 500 m ² / g or more, the fillers are strongly aggregated so that the dispersibility is deteriorated. When the specific surface area is 30 m ² / g or less, a sufficient effect for improving the mechanical strength cannot be obtained.
The specific surface area of the silica filler (C) can be measured by a conventional method, for example, the BET specific surface area method.

The silica filler (C) preferably has an average primary particle size of 100 nm or less, particularly 20 nm or less.
By using the silica filler (C) that is within the range of the average primary particle diameter, the function as the silica filler (C) described above can be remarkably exhibited. When the average primary particle size is 100 nm or more, a sufficient effect for improving the mechanical strength cannot be obtained.
The average primary particle diameter of the silica filler (C) can be measured by a conventional method. For example, on a transmission electron microscope image, a particle diameter of 2500 or more random particles can be measured from a silica fine particle sample, and an average primary particle diameter can be obtained by number average.

  A silica filler (C) may be used individually by 1 type, and may be used in combination of 2 or more type. For example, silica fillers (C) that have been surface-treated using different hydrophobic functional group-containing silane coupling agents may be combined.

The 1st mixing component of this invention may contain the well-known component mix | blended with a silicone rubber-type curable composition other than said (A)-(C) component. Examples thereof include diatomaceous earth, iron oxide, zinc oxide, titanium oxide, barium oxide, magnesium oxide, cerium oxide, calcium carbonate, magnesium carbonate, zinc carbonate, glass wool, and mica. In addition, reaction inhibitors, dispersants, pigments, dyes, antistatic agents, antioxidants, flame retardants, thermal conductivity improvers, and the like can be appropriately blended.

Next, the second mixed component of the present invention will be described.

The second mixed component includes at least a vinyl group-containing linear organopolysiloxane (A) and a catalyst (D).

The catalyst (D) is a component that acts as a catalyst for vulcanization, and the amount added is a catalytic amount. Any component may be used as long as it can be vulcanized, but a platinum-based catalyst is generally preferred from the viewpoint of curing characteristics, and examples thereof include the following platinum or platinum compounds.
As platinum or a platinum compound, known components can be used as specific components. For example, platinum black, platinum supported on silica or carbon black, chloroplatinic acid or chloroplatinic acid alcohol solution, chloroplatinic acid and olefin complex, chloroplatinic acid and vinylsiloxane complex, etc. . Platinum or platinum compound (E) which is a catalyst component may be used alone or in combination of two or more.

  The content of the catalyst (D) is a catalyst amount and can be appropriately set. Specifically, the content is 0.001 to 5 parts by weight with respect to 100 parts by weight of the total amount of (A) to (C). In particular, the range of 0.01 to 0.5 parts by weight is preferable. Thereby, reaction with vinyl group containing organopolysiloxane (A) and organohydrogenpolysiloxane (B) can be advanced more reliably.

  For the second mixed component, the amount of the crosslinking agent and the amount of the catalyst are set in order to improve the handleability during work, to make the viscosity close to be easily mixed with the first mixed component, or without changing the composition ratio of the filler. In order to change the amount, the silica filler (C) may be added. The silica filler (C) is 0 to 150 parts by weight, preferably 20 to 100 parts by weight, more preferably 35 to 80 parts by weight, most preferably 100 parts by weight of the vinyl group-containing linear organopolysiloxane (A). Is 45 to 75 parts by weight. When the silica filler (C) exceeds 150 parts by weight, the second mixed component becomes extremely hard, workability is poor, and it is difficult to obtain a uniform second mixed component.

The 2nd mixing component of this invention may contain the well-known component mix | blended with a silicone rubber-type curable composition other than said (A) and (C) and (D) component. Examples thereof include diatomaceous earth, iron oxide, zinc oxide, titanium oxide, barium oxide, magnesium oxide, cerium oxide, calcium carbonate, magnesium carbonate, zinc carbonate, glass wool, and mica. In addition, reaction inhibitors, dispersants, pigments, dyes, antistatic agents, antioxidants, flame retardants, thermal conductivity improvers, and the like can be appropriately blended.

Next, preparation of a silicone rubber-based curable composition using the first mixed component will be described.

In the silicone rubber-based curable composition using the first mixed component of the present invention, the content ratio of each component is not particularly limited, but the linear organohydrogenpolysiloxane (B) is a vinyl group-containing linear organopolysiloxane. The linear organohydrogenpolysiloxane (B) is preferably contained at a ratio of 0.05 to 5.0 parts by weight with respect to 100 parts by weight of the siloxane (A). It is more preferable to contain it in a proportion. Thereby, since the crosslinked network of silicone rubber is formed more accurately and the density of the crosslinked density is formed in a more appropriate range, the tear strength of the silicone rubber can be increased more effectively.
The silica filler (C) is preferably contained in a proportion of 20 to 100 parts by weight of the silica filler (C) with respect to 100 parts by weight of the vinyl group-containing linear organopolysiloxane (A). It is more preferably contained in a proportion of 35 to 80 parts by weight, and most preferably contained in a proportion of 45 to 75 parts by weight. Thereby, the tensile strength of the silicone rubber can be reliably improved to the target range.

  The silicone rubber-based curable composition using the first mixed component of the present invention may contain known components blended in the silicone rubber-based curable composition in addition to the components (A) to (D). Good. Examples thereof include diatomaceous earth, iron oxide, zinc oxide, titanium oxide, barium oxide, magnesium oxide, cerium oxide, calcium carbonate, magnesium carbonate, zinc carbonate, glass wool, and mica. In addition, reaction inhibitors, dispersants, pigments, dyes, antistatic agents, antioxidants, flame retardants, thermal conductivity improvers, and the like can be appropriately blended.

  The 1st mixing component and 2nd mixing component which are the silicone resin composition masterbatch used for this invention are obtained by mixing the said component uniformly by arbitrary kneading apparatuses. Examples of the kneader include a kneader, two rolls, a Banbury mixer (continuous kneader), a pressure kneader, and the like, and the mixing conditions are not particularly limited.

The first mixed component may be kneaded simultaneously with the above (A) to (D) and other components, or may be kneaded separately. For example, after mixing (A) and (C) and other components, the first mixed component can be prepared by adding (B) and other components. By using the first mixed component, it is possible to obtain an effect that the workability before curing is excellent and the production economy is excellent because it can be stored for a long time. Then, the silicone rubber-type curable composition of this invention is obtained by mixing a 1st mixing component, a catalyst, and arbitrary other components.

The silicone rubber-based curable composition of the present invention may be prepared using a first mixed component, and may be prepared using a plurality of master batches within that range, or may be prepared separately from one or more master batches. It may be prepared by mixing with a silicone resin composition. However, when the catalyst and the crosslinking agent are present in the rubber, the physical properties and storage stability may be affected by the progress of curing. Therefore, it is preferable to add the catalyst last or use the second mixed component.

When using the first mixed component and the second mixed component, for example, (A) and (C), and the other components are mixed in an arbitrary kneading apparatus and then divided into two, and one is (B), The first mixed component is prepared by adding any other component, and the second mixed component is prepared by adding (D) and any other component to the other. By using the first mixed component and the second mixed component, it is possible to obtain an effect that the workability before curing is excellent and the production economy is excellent because it can be stored for a long time. Then, the silicone rubber-based curable composition of the present invention is obtained by mixing the first mixed component, the second mixed component, and any other components.
When the first mixed component and the second mixed component include all necessary components, it is only necessary to mix the first mixed component and the second mixed component at the time of production.

  The silicone rubber-based curable composition of the present invention thus obtained is heated (primary curing) at 140 to 180 ° C. for 5 to 15 minutes, and then post-baked (secondary) at 200 ° C. for 4 hours. A silicone rubber can be obtained by curing.

By curing the silicone rubber-based curable composition of the present invention, the strength of the dumbbell-shaped No. 3 test piece according to JIS K6251 (2004) and the tear strength of the crescent-type test piece according to JIS K6252 (2001) It is possible to obtain a silicone rubber having excellent strength and stability.
By using the silicone rubber having excellent strength as described above, a molded article having excellent mechanical strength can be obtained. By using such a molded body, a silicone rubber medical tube (for example, a catheter) excellent in kink resistance, scratch resistance and insertability can be obtained.

Here, the tear strength is determined using a test piece prepared by curing the silicone-based curable composition of the present invention in accordance with JIS K6252 (2001) except that the thickness of the test piece is 1 mm. Can be measured.
The tensile strength and elongation at break are the test pieces prepared by curing the silicone-based curable composition of the present invention in accordance with JIS K6251 (2004) except that the thickness of the test piece is 1 mm. Can be measured.

  Hereinafter, although an example explains one form of a silicone rubber system curable composition of the present invention, the present invention is not limited to these examples.

The raw materials used in the examples and comparative examples are as follows.
(A1): first vinyl group-containing linear organopolysiloxane, vinyl group content of 0.13 mol%, synthesized by the following synthesis scheme.
(A2): second vinyl group-containing linear organopolysiloxane, vinyl group content 0.92 mol%: synthesized by the following synthesis scheme.
(B): Linear organohydrogenpolysiloxane, "88466" manufactured by Momentive
(C): Untreated silica fine particles (“Aerosil 300” manufactured by Nippon Aerosil Co., Ltd., specific surface area 300 m ² / g, primary average particle diameter 7 nm)
(D): Platinum: “SIPS6831.2” manufactured by Gerest
(E): Hexamethyl group-containing silane coupling agent (“HMDS-EG” manufactured by Chisso Corporation)
(F) Vinyl group-containing silane coupling agent (“1,3-divinyl-1,1,3,3-tetramethyldisilazane” manufactured by Tokyo Chemical Industry Co., Ltd.)
(G) Reaction inhibitor: “1-ethynylcyclohexanol” manufactured by Tokyo Chemical Industry Co., Ltd.
(H) Wetting agent: “XC96-723” manufactured by Momentive
(I) Water

[Synthesis of first vinyl group-containing linear organopolysiloxane (A1)]
A first vinyl group-containing linear organopolysiloxane (A1) was synthesized according to the following formula (6).
Specifically, 74.7 g (252 mmol) of octamethylcyclotetrasiloxane, 2,4,6,8-tetramethyl 2,4,6 was placed in a 300 mL separable flask having a cooling tube and a stirring blade that was purged with Ar gas. , 8-tetravinylcyclotetrasiloxane 0.086 g (0.25 mmol) and potassium siliconate 0.1 g were added, the temperature was raised, and the mixture was stirred at 120 ° C. for 30 minutes. An increase in viscosity was confirmed.
Thereafter, the temperature was raised to 155 ° C., and stirring was continued for 3 hours. After 3 hours, 0.1 g (0.6 mmol) of 1,3-divinyltetramethyldisiloxane was added, and the mixture was further stirred at 155 ° C. for 4 hours.
After 4 hours, the mixture was diluted with 250 mL of toluene and then washed with water three times. The washed organic layer was washed several times with 1.5 L of methanol, and purified by reprecipitation to separate the oligomer and polymer. The obtained polymer was dried under reduced pressure at 60 ° C. overnight to obtain a second vinyl group-containing linear organopolysiloxane (Mn = 277,734, Mw = 573,906, IV value (dl / g) = 0.89).

[Synthesis of second vinyl group-containing linear organopolysiloxane (A2)]
In the synthesis of (A1) above, except that 0.86 g (2.5 mmol) of 2,4,6,8-tetramethyl 2,4,6,8-tetravinylcyclotetrasiloxane was used A second vinyl group-containing linear organopolysiloxane (A2) was synthesized.

[Example 1]
(Preparation of silicone resin composition rubber compound)
First, 100 parts by weight of vinyl group-containing linear organopolysiloxane (A) [(A1) :( A2) = 80 parts by weight: 20 parts by weight], 10 parts by weight of hexamethyldisilazane (E), and divinyltetra A kneaded product (silicone rubber) is prepared by previously kneading 0.5 parts by weight of methyldisilazane (F) and 5.25 parts by weight of water (I) and then kneading by adding 62 parts by weight of silica filler (C). Compound).
The kneading after the addition of the silica filler (C) is performed for the first step of kneading for 1 hour under a nitrogen atmosphere at 60 to 90 ° C. for the coupling reaction, and for the removal of the by-product (ammonia). And a second step of kneading for 2 hours under conditions of 160 to 180 ° C. in a reduced pressure atmosphere. Thereafter, 2 parts by weight of a wetting agent (H) was added and kneaded for 20 minutes.
Moreover, the obtained kneaded material was cooled to room temperature.
The obtained kneaded material is called a silicone resin composition rubber compound.
(Preparation of first mixed component)
With respect to 100 parts by weight of the obtained silicone resin composition rubber compound, using a mixer, (B) 0.55 part by weight of a linear organohydrogenpolysiloxane and (G) 0.1 part by weight of a reaction inhibitor In addition, the mixture was kneaded until uniform.
(Preparation of silicone rubber-based curable composition)
Two rolls were used for the first mixed component, and 0.05 parts by weight of (D) platinum was added and mixed until uniform to prepare a silicone rubber-based curable composition. Table 1 shows the weight ratio of each raw material. The silicone rubber-based curable composition was repeatedly prepared three times by the same operation.
Table 1 shows the working time of each step after the preparation of the silicone resin composition rubber compound.

(Evaluation of silicone rubber-based curable composition)
<Tear strength and tear stroke>
The obtained silicone rubber-based curable composition was pressed at 170 ° C. and 10 MPa for 10 minutes, molded into a 1 mm sheet, and primary cured.
Subsequently, it was heated at 200 ° C. for 4 hours and secondarily cured.
Using the obtained sheet-like silicone rubber, a crescent-shaped test piece was prepared according to JIS K6252 (2001), and the tear strength of the crescent-shaped test piece according to JIS K6252 (2001) was measured. However, the thickness of the test piece was 1 mm.
About the silicone rubber type curable composition produced 3 times by the above method, 3 test pieces were measured, respectively, and a total of 9 test pieces were measured. Table 1 shows the results of the average value calculated for evaluating the strength and the standard deviation value calculated for evaluating the dispersion of physical properties of the nine test pieces.

<Tensile strength, tensile elongation, and tensile strength at 100% strain>
The obtained silicone rubber-based curable composition was pressed at 170 ° C. and 10 MPa for 10 minutes, molded into a 1 mm sheet, and primary cured.
Subsequently, it was heated at 200 ° C. for 4 hours and secondarily cured.
Using the obtained sheet-like silicone rubber, a dumbbell-shaped No. 3 test piece was prepared according to JIS K6251 (2004), and the tensile strength of the dumbbell-shaped No. 3 test piece according to JIS K6251 (2004) and The elongation at break (strain) and the tensile strength at 100% strain were measured. The tensile strength at 100% strain is used as a substitute characteristic of hardness, and is hereinafter referred to as 100% modulus. However, the thickness of the test piece was 1 mm.
About the silicone rubber type curable composition produced 3 times by the above method, 3 test pieces were measured, respectively, and a total of 9 test pieces were measured. Table 1 shows the results of the average value calculated for evaluating the strength and the standard deviation value calculated for evaluating the dispersion of physical properties of the nine test pieces. The results are shown in Table 1.

[Example 2]
(Preparation of silicone resin composition rubber compound)
A silicone resin composition rubber compound was prepared in the same procedure as in Example 1.
(Preparation of first mixed component)
Using 100 parts by weight of the obtained silicone resin composition rubber compound, a mixer (TK5-2M type double arm kneader manufactured by Toshin Co., Ltd.) was used, and (B) 1.1 parts by weight of a linear organohydrogenpolysiloxane And (G) 0.2 part by weight of a reaction inhibitor was added and kneaded until uniform.
(Preparation of second mixed component)
To 100 parts by weight of the rubber compound obtained in Example 1, (D) 0.1 part by weight of platinum was added and kneaded until uniform by using a mixer.
(Preparation of silicone rubber-based curable composition)
Using two rolls (6 × 15 test roll manufactured by Kansai Roll Co., Ltd.), the above two kinds of mixed components were mixed for 2 minutes to obtain a uniform state to prepare a silicone rubber-based curable composition. Table 1 shows the weight ratio of each raw material. The silicone rubber-based curable composition of Example 2 was repeatedly produced three times by the same operation. Table 1 shows the working time of each step after the preparation of the silicone resin composition rubber compound.
Moreover, the test piece produced using the obtained silicone rubber-type curable composition was evaluated similarly to Example 1. FIG. The results are shown in Table 1.

（※1）成分(A1) と成分(A2)と成分(C)と成分(E)と成分(F) と成分(H)と成分(I)から得られたシリコーン樹脂組成物ゴムコンパウンド100重量部に対して0.55重量部
（※2）成分(A1) と成分(A2)と成分(C)と成分(E)と成分(F) と成分(H)と成分(I)から得られたシリコーン樹脂組成物ゴムコンパウンド100重量部に対して0.05重量部
（※3）成分(A1) と成分(A2)と成分(C)と成分(E)と成分(F) と成分(H)と成分(I)から得られたシリコーン樹脂組成物ゴムコンパウンド100重量部に対して0.1重量部

(* 1) 100 weight of silicone resin composition rubber compound obtained from component (A1), component (A2), component (C), component (E), component (F), component (H) and component (I) 0.55 parts by weight (* 2) Silicone obtained from component (A1), component (A2), component (C), component (E), component (F), component (H) and component (I) 0.05 parts by weight (* 3) Component (A1), Component (A2), Component (C), Component (E), Component (F), Component (H) and Component (100 parts by weight of the resin composition rubber compound) 0.1 parts by weight per 100 parts by weight of the silicone resin composition rubber compound obtained from I)

[Comparative Example 1]
(Preparation of silicone rubber-based curable composition)
Using 100 parts by weight of the silicone resin composition rubber compound obtained in Example 1, using two rolls, adding 0.55 parts by weight of (B) linear organohydrogenpolysiloxane and mixing until uniform. Subsequently, (G) 0.1 part by weight of reaction inhibitor is added and kneaded until uniform, and (D) 0.05 part by weight of platinum is mixed and kneaded until uniform. A composition was prepared. Table 2 shows the weight ratio of each raw material. The silicone rubber-based curable composition of Comparative Example 1 was also prepared three times by the same operation. Table 2 shows the working time of each step after the preparation of the silicone resin composition rubber compound.
Moreover, the test piece produced using the obtained silicone rubber-type curable composition was evaluated similarly to Example 1. FIG. The results are shown in Table 2.

[Comparative Example 2]
(Preparation of silicone rubber-based curable composition)
Using 100 parts by weight of the silicone resin composition rubber compound obtained in Example 2, using two rolls, (D) adding 0.05 part by weight of platinum and mixing until uniform, then (G) Add 0.1 part by weight of reaction inhibitor and knead until uniform, then add (B) 0.55 part by weight of straight-chain organohydrogenpolysiloxane and mix until uniform. A composition was prepared. Table 2 shows the weight ratio of each raw material. The silicone rubber-based curable composition of Comparative Example 2 was repeatedly produced three times by the same operation. Table 2 shows the working time of each step after the preparation of the silicone resin composition rubber compound.
Moreover, the test piece produced using the obtained silicone rubber-type curable composition was evaluated similarly to Example 1. FIG. The results are shown in Table 2.

（※1）成分(A1) と成分(A2)と成分(C)と成分(E)と成分(F) と成分(H)と成分(I)から得られたシリコーン樹脂組成物ゴムコンパウンド100重量部に対して0.55重量部
（※2）成分(A1) と成分(A2)と成分(C)と成分(E)と成分(F) と成分(H)と成分(I)から得られたシリコーン樹脂組成物ゴムコンパウンド100重量部に対して0.05重量部
（※3）成分(A1) と成分(A2)と成分(C)と成分(E)と成分(F) と成分(H)と成分(I)から得られたシリコーン樹脂組成物ゴムコンパウンド100重量部に対して0.1重量部

(* 1) 100 weight of silicone resin composition rubber compound obtained from component (A1), component (A2), component (C), component (E), component (F), component (H) and component (I) 0.55 parts by weight (* 2) Silicone obtained from component (A1), component (A2), component (C), component (E), component (F), component (H) and component (I) 0.05 parts by weight (* 3) Component (A1), Component (A2), Component (C), Component (E), Component (F), Component (H) and Component (100 parts by weight of the resin composition rubber compound) 0.1 parts by weight per 100 parts by weight of the silicone resin composition rubber compound obtained from I)

Example 1 and Comparative Example 1 use the same composition and the same lot of the silicone resin composition rubber compound. Example 1 kneads the catalyst after preparing the first mixed component, while Comparative Example 1 uses silicone. A silicone rubber-based curable composition was prepared by kneading a crosslinking agent, a reaction inhibitor, and a catalyst sequentially with the resin composition rubber compound. That is, the effect of preparing the first mixed component in advance can be seen.
As shown in Table 3, in the case of producing a silicone rubber sheet obtained by curing a silicone rubber-based curable composition, in Example 1, since the first mixed component can be produced and stored, only the catalyst is kneaded. On the other hand, Comparative Example 1 can be stored after preparing the silicone resin composition rubber compound, but it was necessary to mix a cross-linking agent and a catalyst having different viscosities thereafter. That is, Example 1 is superior to Comparative Example 1 in that the mixing time required for sheet processing is significantly shortened, so that the actual production economy is excellent.
In terms of physical properties, Example 1 is superior to Comparative Example 1 in terms of tensile strength and tear strength required for medical materials, and also has tensile strength, tensile elongation at break, tear strength, and 100% modulus. Standard deviation is small. That is, it can be seen that there is little variation in various physical properties. It is considered that the variation in physical properties is affected by the accuracy of chemical introduction and the kneading time after the crosslinking agent (B) and catalyst (D) are introduced in the rubber. In Example 1, compared with Comparative Example 1, after adding the crosslinking agent (B) and the catalyst (D) into the rubber, the time required for mixing is shorter, and since it is constant, it is excellent in strength and has variations in physical properties. Was suppressed.

Example 2 and Comparative Example 2 use the same composition and the same lot of silicone resin composition rubber compound. As shown in Table 4, Example 2 is produced by using the first mixed component and the second mixed component. Of course, the mixing time after adding the crosslinking agent and the catalyst can be made constant. On the other hand, the crosslinking agent is finally kneaded in Comparative Example 2, but the viscosity is greatly different and the amount is large, so that the mixing time after adding the crosslinking agent and the catalyst is long, and it is difficult to make it constant. That is, the mixing time after addition of the crosslinking agent and the catalyst is different, and the effect when it is not constant can be seen.

＊１：シリコーン樹脂組成物ゴムコンパウンド及び第１混合成分及び第２混合成分は長期保存が可能であるので、その工程を除いた混合時間。

＊１：シリコーン樹脂組成物ゴムコンパウンド及び第１混合成分及び第２混合成分は長期保存が可能であるので、その工程を除いた混合時間。

As shown in Table 4, as described above, the mixing time required at the time of sheet processing is greatly shortened, and the actual production economy is excellent.
In terms of physical properties, Example 2 is superior to Comparative Example 2 in terms of tensile strength and tear strength required for medical materials. In particular, the tensile strength, the elongation at break, the tear strength, and the standard deviation of 100% modulus of Example 2 are significantly smaller than those of Comparative Example 2. That is, the variation in various physical properties is remarkably improved.
As described above, after the cross-linking agent (B) and the catalyst (D) were introduced into the rubber, the time required for mixing was short and constant, so that the strength was excellent and variations in physical properties were suppressed.

* 1: Since the silicone resin composition rubber compound, the first mixed component and the second mixed component can be stored for a long time, the mixing time excluding the step.

* 1: Since the silicone resin composition rubber compound, the first mixed component and the second mixed component can be stored for a long time, the mixing time excluding the step.

Claims (13)

A silicone rubber-based curable resin composition comprising a first mixed component containing a crosslinking agent and a vinyl group-containing linear organopolysiloxane (A). The silicone rubber-based curable resin composition according to claim 1, wherein the second crosslinking agent is a linear organohydrogenpolysiloxane (B). The first mixed component includes a vinyl group-containing linear organopolysiloxane (A), a linear organohydrogenpolysiloxane (B), an inorganic silicon filler (C) having a hydrophobic functional group on the surface, The silicone rubber-based curable resin composition according to claim 1 or 2, comprising: The silicone rubber-based curable composition according to any one of claims 1 to 3, wherein the vinyl group-containing linear organopolysiloxane (A) is represented by the following formula (1).

(In the formula (1), m is an integer, n represents an integer of 3000 to 10000 of 1 to 1000, ^{R 1} is a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, an alkenyl group, an aryl group, or their R ² is a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, an alkenyl group, an aryl group, or a hydrocarbon group combining these, R ³ is a substituted or unsubstituted group having 1 to 8 carbon atoms An unsubstituted alkyl group, an aryl group, or a hydrocarbon group that is a combination thereof, and at least one of a plurality of R ¹ and R ² is an alkenyl group.)
The silicone rubber-based curable composition according to claim 2 or 3, wherein the linear organohydrogenpolysiloxane (B) is represented by the following formula (2).

(In Formula (2), m is an integer of 0-300, n is an integer of (300-m). R ⁴ is a substituted or unsubstituted alkyl group, alkenyl group, aryl group having 1 to 10 carbon atoms, R ⁵ is a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, an alkenyl group, an aryl group, a combined hydrocarbon group, or a hydride group. However, at least two of R ⁴ and R ⁵ are hydride groups, and R ⁶ is a substituted or unsubstituted alkyl group having 1 to 8 carbon atoms, an aryl group, or a hydrocarbon group that is a combination thereof. is there.) The silicone rubber-based curable resin according to claim 3, wherein the first mixed component contains 0 to 150 parts by weight of an inorganic silicon filler (C) with respect to 100 parts by weight of the vinyl group-containing linear organopolysiloxane (A). Composition.   The silicone rubber-based curable resin composition according to claim 3 or 6, wherein the inorganic silicon filler (C) includes at least one hydrophobic functional group. 8. The inorganic silicon filler (C) having a hydrophobic functional group on the surface has a specific surface area of 30 to 500 m ² / g and an average primary particle diameter of 100 nm or less. The silicone rubber-based curable resin composition described in 1. A silicone rubber system using the first mixed component according to any one of claims 1 to 8, and a second mixed component comprising a catalyst (D) and a vinyl group-containing linear organopolysiloxane (A). Curable resin composition. The silicone rubber-based curable resin composition according to claim 9, wherein the second mixed component according to claim 9 includes the vinyl group-containing linear organopolysiloxane (A) according to claim 4 and a catalyst (D). object. The second mixed component contains the vinyl group-containing linear organopolysiloxane (A) according to claim 4, the inorganic silicon filler (C) according to claim 8, and the catalyst (D). The silicone rubber-based curable resin composition described. 12. The mixed component according to claim 9, wherein the mixed component contains 0 to 150 parts by weight of the inorganic silicon filler (C) with respect to 100 parts by weight of the vinyl group-containing linear organopolysiloxane (A). Silicone rubber-based curable resin composition. The silicone rubber curable resin composition according to any one of claims 9 to 12, wherein the catalyst is a platinum compound.