JP2018058950A - Curable polyorganosiloxane composition and electric/electronic apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a curable polyorganosiloxane composition for forming a cured coating film having a low viscosity, good coating properties without a solvent, high hardness, excellent scratch resistance or the like.SOLUTION: There is provided a curable polyorganosiloxane composition which comprises (A) 100 pts.mass of an alkoxy group-containing polyorganosiloxane mixture containing (A1) an alkoxy group-containing polyorganosiloxane having a three-dimensional network structure having a (meth)acryloxy alkyl group and two or more alkoxy groups and containing a polymer unit in which 5 or more and 100 or less bifunctional siloxane units are bound linearly in the three-dimensional network structure and an Mw of 2000 to 100000, (B1) 0.0001 to 20 pts.mass of a condensation reaction curing catalyst and (B2) 0.001 to 20 pts.mass of a photoreaction initiator as an ultraviolet-curing catalyst.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a curable polyorganosiloxane composition and electrical / electronic equipment, and in particular, forms a cured film excellent in scratch resistance and adhesion durability, and is useful as a coating material for electrical / electronic equipment. The present invention relates to a polyorganosiloxane composition and an electric / electronic device having a cured film of the curable polyorganosiloxane composition.

  Conventionally, various polyorganosiloxane compositions that are cured at room temperature to produce a rubber-like cured product are known. Among them, for applications such as coating materials and potting materials for electrical and electronic parts, it is a type that causes a curing reaction by contact with moisture in the air, and releases alcohol, acetone, etc. during curing Is commonly used. Such a type of polyorganosiloxane composition has good workability, and since alcohol and acetone released during curing are less corrosive to metals, there is little risk of corroding electrodes and wiring, Moreover, it has the advantage that it is excellent also in adhesiveness etc.

  In particular, as a conformal coating agent applied to protect the surface of an electric / electronic component or a circuit board on which the electric / electronic component is mounted from a use environment, a coating material made of a low-viscosity room temperature-curable polyorganosiloxane composition (for example, , And Patent Documents 1 and 2) and a coating material in which a silicone resin is dissolved in a solvent is used.

However, a coating material made of a low-viscosity room temperature-curable polyorganosiloxane composition has a cured film that is brittle and has low hardness, and scratch strength such as scratch resistance is not sufficient.
In addition, solvent-type coating materials containing silicone resins require a solvent removal process by heating during curing, so the volatilization of the solvent can lead to deterioration of the work environment and the electrical / electronic components and circuit boards on which they are mounted. There was a risk of causing corrosion and deterioration. Furthermore, in order to improve the working environment, a high investment was required to recover the solvent without releasing it into the atmosphere.

  Furthermore, a coating material (for example, see Patent Document 3) made of an ultraviolet curable polyorganosiloxane composition is also used, but not only is the portion that is shaded when irradiated with ultraviolet rays cured insufficiently. There were problems such as bleeding out after curing. In addition, there was a problem of oxygen curing inhibition, and there were many points lacking in practicality. That is, the ultraviolet curable photocuring material that cures by radical polymerization has a problem that oxygen causes inactivation of radical species generated from the photoinitiator and stops the growth of monomers during the radical reaction. .

JP-A-7-173435 JP 7-238259 A Japanese National Patent Publication No. 8-9656

  The present invention has been made to solve these problems, and is a curable polyorganosiloxane that forms a cured film having low viscosity, no solvent, good coatability, high hardness, and excellent scratch resistance. An object is to provide a composition.

The curable polyorganosiloxane composition of the present invention is
A polyorganosiloxane having one or more (meth) acryloxyalkyl groups bonded to a silicon atom and two or more alkoxy groups and having a three-dimensional network structure, and having 5 or more and 100 or less bifunctional siloxanes (A1) three-dimensional network structure alkoxy group-containing polyorganosiloxane having a weight average molecular weight (Mw) of 2,000 to 100,000, comprising polymer units in which the units are linearly bonded in the three-dimensional network structure. Containing (A) 100 parts by mass of an alkoxy group-containing polyorganosiloxane mixture,
(B1) condensation reaction curing catalyst 0.0001-20 parts by mass;
(B2) It contains 0.001 to 20 parts by mass of a photoreaction initiator that is an ultraviolet curing catalyst.

  The electrical / electronic device of the present invention is characterized in that it has a film made of a cured product of the curable polyorganosiloxane composition of the present invention on the surface of the electrode and / or wiring.

In the present invention, an “alkoxy group bonded to a silicon atom” is sometimes simply referred to as an “alkoxy group”. Further, the “(meth) acryloxyalkyl group bonded to a silicon atom” means a (meth) acryloxy group bonded to a silicon atom via an alkylene group, and may be simply referred to as “(meth) acryloxy group”. . The “(meth) acryloxy group” represents an acryloxy group and / or a methacryloxy group, and the “methacryloxy group” is also referred to as a “methacryloxy group”.
Furthermore, in this specification, the polyorganosiloxane represented by the formula (x) is also referred to as polyorganosiloxane (x). As described above, an abbreviation including a symbol indicating the formula may be used for the compound represented by the formula.

  The curable polyorganosiloxane composition of the present invention has a low viscosity and good applicability, and can be applied as it is by a normal application method without being diluted with a solvent. And a coating film hardens | cures rapidly, forms a hardened film with high hardness, excellent scratch resistance, and good adhesion durability. Therefore, it is useful for applications such as coating materials and potting materials for electric / electronic devices, and is particularly suitable for applications for coating electric / electronic components such as conformal coating agents.

It is sectional drawing which shows an example of the electric / electronic device of this invention.

Embodiments of the present invention will be described below.
The curable polyorganosiloxane composition of the embodiment includes (A) 100 parts by mass of an alkoxy group-containing polyorganosiloxane mixture, (B1) 0.0001 to 20 parts by mass of a condensation reaction curing catalyst, and (B2) a photoreaction initiator. Contains 0.001-20 parts by weight. (A) The alkoxy group-containing polyorganosiloxane mixture is a polyorganosiloxane having one or more (meth) acryloxyalkyl groups and two or more alkoxy groups in the molecule and having a three-dimensional network structure. (A1) three-dimensional, having a weight average molecular weight (Mw) of 2,000 to 100,000, comprising in a three-dimensional network structure a polymer unit in which from 1 to 100 bifunctional siloxane units are linearly bonded It contains a polyorganosiloxane having a network structure alkoxy group.

  In the curable polyorganosiloxane composition of the embodiment, the (A) alkoxy group-containing polyorganosiloxane mixture has an alkoxy group and / or a (meth) acryloxyalkyl group, is liquid at room temperature, and has a viscosity at 23 ° C. of 3 to 3. Polyorganosiloxane (A2) which is 500 mPa · s can be included. In the present specification, “normal temperature” means a normal temperature at which neither heating nor cooling is performed, for example, 23 ° C. Hereinafter, the polyorganosiloxane that is the component (A2) may be referred to as a second polyorganosiloxane.

In addition, the curable polyorganosiloxane composition of the embodiment further includes (C) Formula: R ¹ _c Si (OR ² ) _{4 -c} (R ¹ is independently an alkyl group having 1 to 6 carbon atoms. , An alkenyl group having 2 to 6 carbon atoms, an aryl group having 6 to 12 carbon atoms, or a (meth) acryloxyalkyl group, and R ² is independently an alkyl group having 1 to 6 carbon atoms. And c is 0, 1 or 2.) and / or a partial hydrolysis-condensation product thereof.
Hereinafter, each component which comprises the curable polyorganosiloxane composition of embodiment, a content rate, etc. are demonstrated.

[(A) Alkoxy group-containing polyorganosiloxane mixture]
In the embodiment, the alkoxy group-containing polyorganosiloxane mixture as the component (A) is a component that serves as a base of the curable composition. The component (A) contains (A1) an alkoxy group-containing polyorganosiloxane having a three-dimensional network structure. In addition, in the present specification, the component (A) includes only (A1) an alkoxy group-containing polyorganosiloxane having a three-dimensional network structure and (A2) does not contain a second polyorganosiloxane. It is called “mixture”.

[(A1) Alkoxy group-containing polyorganosiloxane having a three-dimensional network structure]
In an embodiment of the present invention, (A1) an alkoxy group-containing polyorganosiloxane having a three-dimensional network structure that constitutes at least part of the component (A) has one or more (meth) acryloxyalkyl groups in the molecule. It has 2 or more alkoxy groups.
The component (A1) is a unit in which 5 or more and 100 or less of bifunctional siloxane units (hereinafter referred to as D1 units) represented by the formula: R ⁰ ₂ SiO _2/2 are bonded in a linear form (hereinafter referred to as “A1”). And a poly-D1 unit) and a trifunctional siloxane unit represented by the formula: R ⁰ SiO _3/2 (hereinafter referred to as T1 unit).

（Ｒ_ａは、独立して、水素原子またはメチル基であり、Ｑ_１は、独立して、炭素数１〜５個のアルキレン基である。）で表される（メタ）アクリロキシアルキル基が挙げられる。なお、Ｑ_１としては、トリメチレン基（プロピレン基）が好ましい。
置換の一価炭化水素基としては、炭素数１〜６個のアルキル基の水素原子の一部がハロゲン原子またはシアノアルキル基で置換された基が挙げられる。 In the formulas representing the D1 unit and the T1 unit, R ⁰ is independently a substituted or unsubstituted monovalent hydrocarbon group.
The unsubstituted monovalent hydrocarbon group includes an alkyl group having 1 to 6 carbon atoms (preferably a methyl group), an aryl group having 6 to 12 carbon atoms (preferably a phenyl group), and 1 to 6 carbon atoms. Alkoxy groups (preferably, methoxy group, ethoxy group), and formula (a):

(R _a is independently a hydrogen atom or a methyl group, and Q ₁ is independently an alkylene group having 1 to 5 carbon atoms.) A (meth) acryloxyalkyl group represented by Can be mentioned. Q ₁ is preferably a trimethylene group (propylene group).
Examples of the substituted monovalent hydrocarbon group include groups in which a part of hydrogen atoms of an alkyl group having 1 to 6 carbon atoms is substituted with a halogen atom or a cyanoalkyl group.

In the D1 unit constituting the poly D1 unit, the plurality of R ⁰ are preferably methyl groups. Moreover, it is preferable that at least 1 of several ^R0 which all T1 units have is a (meth) acryloxyalkyl group represented by the said Formula (a).

  In the poly D1 unit contained in the component (A1), the number of bonds of the D1 unit is 5 or more and 100 or less. When the number of bonds in the D1 unit is less than 5, the flexibility and flexibility of the cured film are insufficient. On the other hand, if the number of bonds in the D1 unit exceeds 100, the scratch resistance of the cured film is lowered, which is not preferable. When the number of bonds in the D1 unit is 5 or more and 100 or less, a cured film having high hardness, excellent scratch resistance, heat resistance and adhesion durability, and excellent flexibility and flexibility can be obtained. . The number of bonds in the D1 unit is preferably 10 or more and 100 or less, and particularly preferably 12 or more and 60 or less.

(A1) In addition to the poly D1 unit and the T1 unit, the alkoxy group-containing polyorganosiloxane having a three-dimensional network structure has less than 5 D1 units (hereinafter referred to as non-poly D1 units) and / or. A monofunctional siloxane unit represented by the formula: R ¹⁰ ₃ SiO _1/2 (hereinafter referred to as M1 unit) may be contained. In the formula representing the M1 unit, R ¹⁰ are each independently a monovalent hydrocarbon group. Examples of the monovalent hydrocarbon group include a group similar to R ⁰ in the D1 unit and the T1 unit, and a silicon oligomer group containing a poly D1 unit. When it has M1 unit, it is preferable that at least 1, preferably 2 or more of a plurality of R ¹⁰ possessed by all M1 units is an alkoxy group or a silicon oligomer group containing an alkoxy group.

  (A1) The alkoxy group-containing polyorganosiloxane having a three-dimensional network structure contains the poly D1 unit in the three-dimensional network structure. Here, “containing the poly D1 unit in the three-dimensional network structure” means that the poly D1 unit forms part of the three-dimensional network structure formed by the T1 unit and the non-poly D1 unit. Since the M1 unit does not form the main body of the three-dimensional network structure, when the poly D1 unit is present in the M1 unit, it is not included in the three-dimensional network structure.

  The alkoxy group-containing polyorganosiloxane having a three-dimensional network structure as component (A1) is an alkoxylation reaction involving dealcoholization of a silanol group-containing polyorganosiloxane (A1a) having a silanol group at the terminal and having a three-dimensional network structure. Can be obtained. The “silanol group” refers to a group in which a hydroxyl group is bonded to a silicon atom.

  The silanol group-containing polyorganosiloxane (A1a) having a three-dimensional network structure for obtaining (A1) by alkoxylation has a poly D1 unit and a T1 unit, and optionally includes a non-poly D1 unit and an M1 unit. It is a polyorganosiloxane. The hydroxyl group constituting the silanol group is preferably bonded to at least one of a silicon atom constituting the non-poly D1 unit, a silicon atom constituting the M1 unit, and a silicon atom constituting the T1 unit. It is particularly preferable that the hydroxyl group constituting the silanol group is bonded to the silicon atom constituting the T1 unit.

  The silanol group-containing polyorganosiloxane (A1a) is, for example, an α, ω-dihydroxypolyalkyl having silanol groups at both ends, which is one or more of silane compounds that are T1 unit sources, and a poly D1 unit source. Siloxane can be obtained by hydrolysis and condensation by a known method. The “T1 unit source” means that T1 units in the silanol group-containing polyorganosiloxane (A1a) are formed by hydrolysis and condensation. Similarly, “D1 unit source” means that D1 units in the silanol group-containing polyorganosiloxane (A1a) are formed by hydrolysis and condensation, and “poly D1 unit source” means hydrolysis and condensation. It means that the poly D1 unit in the silanol group-containing polyorganosiloxane (A1a) is formed by condensation.

  Here, α, ω-dihydroxypolyalkylsiloxane which is a poly D1 unit source is a polymer having a structure in which 5 or more and 100 or less D1 units are linearly bonded and hydroxyl groups are bonded to silicon atoms at both ends. Is used. In the preparation of the silanol group-containing polyorganosiloxane (A1a), as starting materials for hydrolysis and condensation, a silane compound as a T1 unit source and an α, ω-dihydroxypolyalkylsiloxane as a poly D1 unit source together with a D1 unit One kind or two or more kinds of silane compounds as a source can also be used.

  Examples of silane compounds that are T1 unit sources include trialkoxysilanes such as methyltrimethoxysilane, methyltriethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, phenyltrimethoxysilane, and phenyltriethoxysilane, and methyltrimethoxysilane. Mention may be made of trichlorosilanes such as chlorosilane, vinyltrichlorosilane and phenyltrichlorosilane. One or more of these silane compounds can be used as the T1 unit source. Further, trialkoxysilanes such as acryloxypropyltrimethoxysilane, methacryloxypropyltrimethoxysilane, acryloxypropyltriethoxysilane, and methacryloxypropyltriethoxysilane having a (meth) acryloxyalkyl group are used. Silane can also be used in combination.

  From the viewpoint of the reactivity of hydrolysis and condensation reaction, the T1 unit source includes methyltrimethoxysilane, vinyltrimethoxysilane, methyltrichlorosilane, vinyltrichlorosilane, phenyltrichlorosilane, acryloxypropyltrimethoxysilane, methacryloxypropyl. The use of trimethoxysilane is preferred. Moreover, methyltrimethoxysilane and methyltrichlorosilane are preferable from the viewpoint of economy and flexibility of the cured film.

  Examples of silane compounds that are D1 unit sources include dimethyldimethoxysilane, dimethyldiethoxysilane, phenylmethyldimethoxysilane, phenylmethyldiethoxysilane, diphenyldimethoxysilane, diphenyldiethoxysilane, vinylmethyldimethoxysilane, and vinylmethyldiethoxysilane. And dialkoxysilanes such as dimethyldichlorosilane, phenylmethyldichlorosilane, phenylethyldichlorosilane, diphenyldichlorosilane, vinylmethyldichlorosilane, and vinylethyldichlorosilane.

  The weight average molecular weight (Mw) of the silanol group-containing polyorganosiloxane as the component (A1a) is preferably from 2,000 to 100,000, more preferably from 3,000 to 70,000. Mw is a value obtained by GPC (gel permeation chromatograph) based on polystyrene.

  (A1a) Preparation of an alkoxy group-containing polyorganosiloxane having a (A1) three-dimensional network structure by alkoxylation of a silanol group-containing polyorganosiloxane can be performed, for example, by the following method.

<First method>
A silane compound (A1b) having two or more alkoxy groups is added to and reacted with the silanol group-containing polyorganosiloxane having a three-dimensional network structure (A1a).

  Examples of the silane compound (A1b) include methyltrimethoxysilane, methyltriethoxysilane, acryloxypropyltrimethoxysilane, methacryloxypropyltrimethoxysilane, acryloxypropyltriethoxysilane, and methacryloxypropyltriethoxysilane. Dialkoxy such as dimethyldimethoxysilane, dimethyldiethoxysilane, acryloxypropylmethyldimethoxysilane, methacryloxypropylmethyldimethoxysilane, acryloxypropylmethyldiethoxysilane, methacryloxypropylmethyldiethoxysilane Silanes can be mentioned. The use of trialkoxysilanes is preferred.

  (A1a) When the silanol group-containing polyorganosiloxane having a three-dimensional network structure has a (meth) acryloxyalkyl group, any of the above-described silane compounds may be used as the component (A1b). When the (A1a) component does not have a (meth) acryloxyalkyl group, as the (A1b) component, a silane compound having a (meth) acryloxyalkyl group and having two or more alkoxy groups is added and reacted. .

  Examples of the silane compound having a (meth) acryloxyalkyl group and having two or more alkoxy groups include the aforementioned acryloxypropyltrimethoxysilane, methacryloxypropyltrimethoxysilane, acryloxypropyltriethoxysilane, and methacryloxy. Examples include propyltriethoxysilane, acryloxypropylmethyldimethoxysilane, methacryloxypropylmethyldimethoxysilane, acryloxypropylmethyldiethoxysilane, methacryloxypropylmethyldiethoxysilane, and the like. Among these, acryloxypropyltrimethoxysilane and methacryloxypropyltrimethoxysilane are particularly preferable from the viewpoints of reactivity, ease of handling, high reactivity after alkoxylation, safety and economy.

  (A1a) When the (A1b) silane compound is added to and reacted with a silanol group-containing polyorganosiloxane having a three-dimensional network structure, the (A1a) component silanol group and (A1b) the alkoxy group of the silane compound In this case, a dealcoholization reaction occurs, and a polyorganosiloxane having a terminal blocked with an alkoxysilyl group is obtained. Thus, an alkoxy group-containing polyorganosiloxane having a three-dimensional network structure as component (A1) is obtained.

<Second method>
A linear silanol group-containing polyorganosiloxane (A1c) having a silanol group at the terminal is mixed with the above-described (A1a) silanol group-containing polyorganosiloxane having a three-dimensional network structure. (A1b) A silane compound having two or more alkoxy groups is added and reacted.

  Here, as the (A1c) linear silanol group-containing polyorganosiloxane, it is preferable to use α, ω-dihydroxypolydialkylsiloxane having silanol groups at both ends. (A1c) As a linear silanol group-containing polyorganosiloxane, 5 to 100 D1 which are poly D1 unit sources used in the preparation of the (A1a) three-dimensional network silanol group-containing polyorganosiloxane It is also possible to use α, ω-dihydroxypolydialkylsiloxanes whose units are linearly bonded. (A1c) The Mw of the linear silanol group-containing polyorganosiloxane is preferably in the range of 200 to 200,000, more preferably in the range of 300 to 100,000.

  (A1b) Examples of the silane compound having two or more alkoxy groups include the same silane compounds as those described in the first method. As in the first method, when (A1a) the silanol group-containing polyorganosiloxane having a three-dimensional network structure has a (meth) acryloxyalkyl group, (A1b) as the component, Any of these may be used, but when the component (A1a) does not have a (meth) acryloxyalkyl group, the component (A1b) has a (meth) acryloxyalkyl group and two alkoxy groups. The silane compound having the above is added and reacted.

(A1a) A mixture of a silanol group-containing polyorganosiloxane having a three-dimensional network structure and (A1c) a linear silanol group-containing polyorganosiloxane, (A1b) adding a silane compound having two or more alkoxy groups to react. As a result, a dealcoholization reaction occurs between the silanol group of the component (A1a) and the silanol group of the component (A1c) and the alkoxy group of the (A1b) silane compound, and the end is blocked with an alkoxysilyl group. Organosiloxane is obtained. At this time, a part of the silanol group of the component (A1a) and a part of the silanol group of the component (A1c) are dehydrated and condensed, resulting in a siloxane bond, resulting in an increase in molecular weight.
Thus, an alkoxy group-containing polyorganosiloxane having a three-dimensional network structure as component (A1) is obtained.

<Third method>
(A1a) A linear alkoxy group-containing polyorganosiloxane (A1d) having an alkoxy group and a (meth) acryloxyalkyl group is added to the silanol group-containing polyorganosiloxane having a three-dimensional network structure and reacted.

  Here, as the (A1d) linear alkoxy group-containing polyorganosiloxane, an α, ω- (meth) acryloxyalkylalkoxysilyl group-containing polysiloxane having an alkoxy group and a (meth) acryloxyalkyl group at both ends respectively. It is preferable to use a dialkylsiloxane, and it is more preferable to use an α, ω- (meth) acryloxyalkyldialkoxysilyl group-containing polydialkylsiloxane having two alkoxy groups at both ends. The Mw of the (A1d) alkoxy group-containing polyorganosiloxane is preferably in the range of 2,000 to 150,000.

(A1a) When a (A1d) linear alkoxy group-containing polyorganosiloxane is added to and reacted with a silanol group-containing polyorganosiloxane having a three-dimensional network structure, the (A1a) component silanol group and the (A1d) component A dealcoholization reaction with an alkoxy group occurs. Then, (A1a) a three-dimensional network silanol group-containing polyorganosiloxane and (A1d) a straight-chain alkoxy group-containing polyorganosiloxane are bonded via a siloxane bond generated by a dealcoholization reaction.
Thus, a terminal alkoxy group-containing polyorganosiloxane having a three-dimensional network structure as component (A1) is obtained.

  The (A1) alkoxy group-containing polyorganosiloxane thus obtained is a polyorganosiloxane having a three-dimensional network structure containing a poly D1 unit in which 5 to 100 D1 units are linearly bonded and a T1 unit. is there.

  The weight average molecular weight (Mw) of the component (A1) is preferably 2,000 to 50,000, and more preferably 3,000 to 30,000. The component (A1) is composed of one or more of the alkoxy group-containing polyorganosiloxanes having the above-described three-dimensional network structure. When the component (A1) is composed of two or more types of three-dimensional network structure alkoxy group-containing polyorganosiloxane, if the Mw as the whole component (A1) is 2,000 to 100,000, the Mw of each polyorganosiloxane is Although it does not necessarily need to be 2,000-100,000, it is preferable to exist in this range.

[(A2) Second polyorganosiloxane]
In the curable composition of the embodiment, the (A) polyorganosiloxane mixture as the base component contains (A2) an alkoxy group and / or (A) in addition to the (A1) alkoxy group-containing polyorganosiloxane having a three-dimensional network structure. A polyorganosiloxane having a (meth) acryloxyalkyl group and having a viscosity of 3 to 500 mPa · s at 23 ° C. (second polyorganosiloxane) can be included.

  The second polyorganosiloxane that is the component (A2) has at least one of an alkoxy group and a (meth) acryloxyalkyl group in the molecule, is liquid at room temperature, and has a viscosity (23 ° C.) of 3 to 500 mPa · s. For example, the molecular structure is not particularly limited. It may be a straight chain or a structure having a branched chain (hereinafter referred to as “branched”). A linear polyorganosiloxane is preferred because the viscosity is easily set in the above range. In addition, when using branched polyorganosiloxane, in order to maintain the said viscosity as the whole (A2) component, it is preferable to use together with a linear polyorganosiloxane.

  When the viscosity of the component (A2) is less than 3 mPa · s, the resulting cured product has poor rubber elasticity, and when it exceeds 500 mPa · s, the compatibility with the component (A1) is deteriorated and the composition is uniform. Cannot be obtained. The viscosity of the component (A2) is preferably in the range of 5 to 300 mPa · s, more preferably in the range of 5 to 100 mPa · s.

  The component (A2) is composed of one or more polyorganosiloxanes. When the component (A2) is composed of one kind of polyorganosiloxane, the polyorganosiloxane has an alkoxy group and / or a (meth) acryloxyalkyl group in the molecule and has a viscosity of 3 to 500 mPa · s. It is. When the component (A2) is composed of a mixture of two or more polyorganosiloxanes, each of the polyorganosiloxanes constituting the component (A2) has an alkoxy group and / or a (meth) acryloxyalkyl group in the molecule. And the mixture only has to satisfy the above-mentioned viscosity specification. Therefore, in this case, the viscosity of the individual polyorganosiloxanes constituting the component (A2) does not necessarily satisfy the above definition, but the viscosity of each polyorganosiloxane preferably satisfies the above definition.

  When the component (A2) is a linear polyorganosiloxane, the alkoxy group and / or the (meth) acryloxyalkyl group may be bonded to the silicon atom at the molecular end, or may be bonded to the silicon atom in the middle part. It may be bonded. When it has an alkoxy group, it is preferable that at least one is bonded to the silicon atom at the molecular end. In that case, all of the alkoxy groups may be bonded to the silicon atom at the molecular end, or at least one alkoxy group may be bonded to the silicon atom in the middle part. Moreover, when it has a (meth) acryloxyalkyl group, it is preferable that at least one is bonded to the silicon atom at the molecular end. In that case, all of the (meth) acryloxyalkyl group may be bonded to the silicon atom at the molecular end, or at least one (meth) acryloxyalkyl group is bonded to the middle silicon atom. Also good.

As the linear polyorganosiloxane which is the component (A2), the both-end alkoxysilyl group-capped polyorganosiloxane represented by the formula (a21) is preferable.

In formula (a21), R ³ represents an alkyl group or an alkoxy-substituted alkyl group in which a part of hydrogen atoms of the alkyl group is substituted with an alkoxy group. R ³ is preferably a methyl group.

R ⁴ is an alkyl group having 1 to 6 carbon atoms (preferably a methyl group), an aryl group having 6 to 12 carbon atoms (preferably a phenyl group), and a (meth) acryloxyalkyl group. R ⁵ is an alkyl group having 1 to 6 carbon atoms (preferably a methyl group), an aryl group having 6 to 12 carbon atoms (preferably a phenyl group), or a part of hydrogen atoms of the alkyl group is a halogen atom. Or a monovalent hydrocarbon group substituted with a cyanoalkyl group. Several R < ⁵ > may mutually be same or different.

R ³ and R ⁵ are preferably methyl groups because they are easy to synthesize, have a low viscosity relative to the molecular weight, and give good physical properties to the cured product (cured coating). However, when it is necessary to impart heat resistance or cold resistance to the cured film, it is preferable that a part of R ⁵ is an aryl group such as a phenyl group. At least one of R ⁴ is preferably a (meth) acryloxypropyl group.

  In formula (a21), X represents a divalent oxygen (oxy group) or a divalent hydrocarbon group. Two Xs may be the same or different. Examples of the divalent hydrocarbon group include alkylene groups such as methylene group, ethylene group, propylene group and trimethylene group, and arylene groups such as phenylene group. In view of ease of synthesis, a divalent oxygen atom (oxy group) or an ethylene group is preferable, and an oxy group is particularly preferable.

  In the formula (a21), d is 0 or 1. It is preferable that at least one of the two ds at both ends of the molecule is 1. n is an integer with which the viscosity of the polyorganosiloxane (a21) is 3 to 500 mPa · s, and specifically an integer of 1 ≦ n <250. The viscosity of the polyorganosiloxane (a21) is preferably in the range of 5 to 100 mPa · s, and the value of n is preferably an integer of 3 to 100.

  Such polyorganosiloxane (a21) is obtained, for example, by ring-opening polymerization or ring-opening copolymerization of a cyclic diorganosiloxane low monomer such as octamethylsiloxane with an acidic catalyst or an alkaline catalyst in the presence of water. The obtained both-end hydroxyl group-containing dioliganopolysiloxane can be obtained by encapping with methyltrimethoxysilane, acryloxypropyltrimethoxysilane, methacryloxypropyltrimethoxysilane or the like.

  The component (A), which is the base component of the curable polyorganosiloxane composition of the present invention, includes (A2) an alkoxy group containing (A2) an alkoxy group-containing polyorganosiloxane having a three-dimensional network structure, if necessary. And / or a polyorganosiloxane having a (meth) acryloxyalkyl group and being liquid at room temperature and having a viscosity of 3 to 500 mPa · s. Moreover, (A) component does not contain (A2) component, but can also be comprised only from (A1) alkoxy group containing polyorganosiloxane which has a three-dimensional network structure.

  The mixing ratio of the component (A1) and the component (A2) is that the entire component (A) is 100 parts by mass, the component (A1) is 20 to 100 parts by mass, and the component (A2) is 80 parts by mass or less. Is preferred. When the compounding amount of the component (A1) is less than 20 parts by mass and the compounding amount of the component (A2) exceeds 80 parts by mass, a cured film having good scratch resistance cannot be obtained. The blending ratio of the component (A1) and the component (A2) is preferably such that the component (A1) is 30 to 90 parts by mass and the component (A2) is 70 to 10 parts by mass, and the component (A1) is 40 to 80 parts by mass. More preferably, the component (A2) is in the range of 60 to 20 parts by mass.

[(B1) condensation reaction curing catalyst]
In the curable polyorganosiloxane composition of the embodiment, the condensation reaction curing catalyst as the component (B1) is composed of the alkoxy groups of the (A) polyorganosiloxane mixture comprising the components (A1) and (A2), and / or It is a curing catalyst for reacting an alkoxy group of component (A) and an alkoxy group of (C) a crosslinking agent described later in the presence of moisture to form a crosslinked structure.

(B1) Examples of the condensation reaction curing catalyst include the following organometallic compounds.
Carboxylic acid metal salts such as iron octoate, cobalt octoate, manganese octoate, zinc octoate, tin naphthenate, tin caprylate, tin oleate; dibutyltin diacetate, dibutyltin dioctoate, dibutyltin dilaurate, dibutyltin oleate, diphenyltin diacetate, Organotin compounds such as dibutyltin oxide, dibutyltin dimethoxide, dibutylbis (triethoxysiloxy) tin, dioctyltin dilaurate; tetraethoxy titanium, tetrapropoxy titanium, tetrabutoxy titanium, diisopropoxy-bis (ethyl acetoacetate) titanium, diiso Propoxy-bis (methyl acetoacetate) titanium, diisopropoxy-bis (acetylacetone) titanium, dibutoxy-bis (acetate) Organic titanium compounds such as ethyl acid) titanium and dimethoxy-bis (ethyl acetoacetate) titanium; tetrapropoxyzirconium, tetrabutoxyzirconium, tetra (acetylacetic acid) zirconium, tributoxy (acetylacetic acid) zirconium, dibutoxy-bis (ethylacetoacetate) ) Organic zirconium compounds such as zirconium, zirconium 2-ethylhexanoate, zirconium tributoxystearate; triethoxyaluminum, triisopropoxyaluminum, diisopropoxy-monosecondary butoxyaluminum, trisecondary butoxyaluminum, diisopropoxy-acetoacetic acid Ethyl aluminum, tris (ethyl acetoacetate) aluminum, aluminum oxide isopropoxide trimer, aluminum Um oxide octylate trimer, aluminum compounds cyclic oligomers, such as aluminum oxide stearate trimer is exemplified.
These organometallic compounds may be used individually by 1 type, and 2 or more types may be mixed and used for them.

  Conventionally, in a room temperature curable polyorganosiloxane composition, an organotin compound such as dibutyltin dioctoate or dibutyltin dilaurate may be used as a curing catalyst, but in the present invention, the curability of the composition ( From the viewpoint of both the speed of curing and the scratch resistance of the cured coating, an organic titanium compound is preferred as the curing catalyst. The use of the organic titanium compound is preferable because a composition having a high catalytic ability and a small amount of impurities can be obtained in the presence of a small amount. Of the organic titanium compounds, titanium chelates such as diisopropoxy-bis (ethylacetylacetate) titanium are particularly preferable.

  The blending amount of the condensation reaction curing catalyst (B1) is 0.0001 to 20 parts by mass, preferably 0.001 to 10 parts by mass with respect to 100 parts by mass of the component (A). If it is less than 0.0001 parts by mass, it does not function sufficiently as a curing catalyst, and not only takes a long time for curing, but also curing at a deep part far from the contact surface with air becomes insufficient. On the other hand, if it exceeds 20 parts by mass, there is no effect corresponding to the blending amount, and it is meaningless and uneconomical. In addition, the storage stability is lowered.

[(B2) Photoinitiator]
(B2) The photoreaction initiator that is an ultraviolet curing catalyst is further provided when the (A1) component has a (meth) acryloxy group, and the (A2) component and the later-described (C) crosslinking agent have a (meth) acryloxy group. This component functions as a radical reaction initiator or a sensitizer when the unsaturated bond of the (meth) acryloxy group of these components is subjected to a radical reaction by ultraviolet irradiation for crosslinking.

  (B2) As a photoinitiator, from the viewpoint of reactivity, aromatic hydrocarbons, acetophenone and derivatives thereof, benzophenone and derivatives thereof, o-benzoylbenzoic acid ester, benzoin and benzoin ether and derivatives thereof, xanthone and derivatives thereof , Disulfide compounds, quinone compounds, halogenated hydrocarbons and amines, and organic peroxides. From the viewpoint of compatibility with the polyorganosiloxane component and stability, a compound containing a substituted or unsubstituted benzoyl group or an organic peroxide is preferred.

Examples of the photoreaction initiator include acetophenone, propiophenone, 2-hydroxy-2-methylpropiophenone, 2,2-dimethoxy-1,2-diphenylethane-1-one (IRUGACURE 651: manufactured by BASF). 2-hydroxy-2-methyl-1-phenyl-propan-1-one (DAROCUR 1173: manufactured by BASF), 1-hydroxy-cyclohexyl-phenyl-ketone (IRUGACURE 184: manufactured by BASF), 1- [4- (2-hydroxyethoxy) -phenyl] -2-hydroxy-2-methyl-1-propan-1-one (IRUGACURE 2959: manufactured by BASF), 2-hydroxy-1- {4- [4- (2-hydroxy -2-methyl-propionyl) -benzyl] phenyl} -2-methyl-propane- 1-one (IRUGACURE 127: manufactured by BASF), 2-methyl-1- (4-methylthiophenyl) -2-morpholinopropan-1-one (IRUGACURE 907: manufactured by BASF), 2-benzyl-2-dimethyl Amino- (4-morpholinophenyl) -butanone-1 (IRUGACURE 369: manufactured by BASF), 2- (dimethylamino) -2-[(4-methylphenyl) methyl] -1- [4- (4-morpholinyl) ) Phenyl] -1-butanone (IRUGACURE 379: manufactured by BASF); 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide (LUCIRIN TPO: manufactured by BASF), bis (2,4,6-trimethylbenzoyl) -Phenylphosphine oxide (IRUGACURE 819: Manufactured by ASF); 1,2-octanedione, 1- [4- (phenylthio)-, 2- (O-benzoyloxime)] (IRUGACURE OXE 01: manufactured by BASF), ethanone, 1- [9-ethyl- 6- (2-methylbenzoyl) -9H-carbazol-3-yl]-, 1- (O-acetyloxime) (IRUGACURE OXE 02: manufactured by BASF); oxyphenylacetic acid, 2- [2-oxo-2- Phenylacetoxyethoxy] ethyl ester and oxyphenylacetic acid, 2- (2-hydroxyethoxy) ethyl ester mixture (IRUGACURE 754: manufactured by BASF), phenylglyoxylic acid methyl ester (DAROCUR MBF: manufactured by BASF), ethyl- 4-Dimethylaminobenzoate (DAROCUR E B: manufactured by BASF), 2-ethylhexyl-4-dimethylaminobenzoate (DAROCUR EHA: manufactured by BASF), bis (2,6-dimethoxybenzoyl) -2,4,4-trimethyl-pentylphosphine oxide (CGI 403) : Manufactured by BASF), benzoyl peroxide, cumene peroxide and the like.
A photoinitiator may be used individually or may use 2 or more types together.

  (B2) The compounding quantity of the photoinitiator which is a component is 0.001-20 mass parts with respect to 100 mass parts of said (A) component, Preferably it is 0.01-10 mass parts. If it is less than 0.001 part by mass, it will not function sufficiently as a curing catalyst, and it will not only take a long time to cure, but in particular, curing at a deep part far from the contact surface with air will be insufficient. On the other hand, if it exceeds 20 parts by mass, there is no effect corresponding to the blending amount, and it is meaningless and uneconomical. Moreover, it causes discoloration and storage stability also decreases.

[Other ingredients]
The curable polyorganosiloxane composition of the embodiment contains a silane compound represented by the formula (C): R ¹ _c Si (OR ² ) _4-c (c1) and / or a partial hydrolysis condensate thereof. be able to. The silane compound (c1) serves as a crosslinking agent for the base polymer that is the component (A).

In the formula (c1), R ¹ is independently an alkyl group having 1 to 6 carbon atoms, an alkenyl group having 2 to 6 carbon atoms, an aryl group having 6 to 12 carbon atoms, or (meth) acryloxy. An alkyl group, and R ² is independently an alkyl group having 1 to 6 carbon atoms. c is 0, 1 or 2. R ¹ is preferably a methyl group, a vinyl group, a phenyl group, an acryloxyalkyl group, or a methacryloxyalkyl group. R ² is preferably a methyl group or an ethyl group.

  Examples of the silane compound (c1) include tetramethoxysilane, tetraethoxysilane, methyltrimethoxysilane, vinyltrimethoxysilane, phenyltrimethoxysilane, methyltriethoxysilane, vinyltriethoxysilane, phenyltriethoxysilane, tetra Propoxysilane, tetraisopropoxysilane, dimethyldimethoxysilane, diphenyldimethoxysilane, methylvinyldimethoxysilane, dimethyldiethoxysilane, acryloxypropyltrimethoxysilane, methacryloxypropyltrimethoxysilane, acryloxypropyltriethoxysilane, methacryloxypropyl Triethoxysilane, methylacryloxypropyldimethoxysilane, methylmethacryloxypropyldimethoxysilane, methyl Methacryloxypropyl diethoxy silane, methyl methacryloxypropyl diethoxy silane and the like. These silane compounds may be used individually by 1 type, and 2 or more types may be mixed and used for them.

  As a silane compound (c1) which is a crosslinking agent, it is easy to synthesize, does not impair the storage stability of the composition, has little corrosiveness to metals, and provides a high crosslinking reaction rate, that is, a curing rate. Is preferably tetramethoxysilane, tetraethoxysilane, methyltrimethoxysilane, vinyltrimethoxysilane, dimethyldimethoxysilane, vinylmethyldimethoxysilane, dimethyldiethoxysilane, (meth) acryloxypropyltrimethoxysilane, , Methyltrimethoxysilane, methylvinyldimethoxysilane, acryloxypropyltrimethoxysilane, and methacryloxypropyltrimethoxysilane are preferably used.

  (C) The partial hydrolysis-condensation product of the silane compound as the component is obtained by converting the silane compound (for example, methyltrimethoxysilane, (meth) acryloxypropyltrimethoxysilane) into water, acid catalyst or alkaline catalyst. Obtained by partial hydrolysis. As for the Si number in the partial hydrolysis-condensation product of a silane compound, 2-20 are preferable. The viscosity (23 ° C.) is preferably 1 to 100 mPa · s.

  (C) When mix | blending a silane compound and / or its partial hydrolysis-condensation product, the compounding quantity is 15 mass parts or less with respect to 100 mass parts of said (A) component, Preferably it is 1-10 mass parts. is there. When the compounding quantity of (C) component exceeds 15 mass parts, the shrinkage rate in the case of hardening will become large, and the physical property after hardening will fall. In addition, the curing rate is remarkably slow, which is economically disadvantageous.

  An isocyanurate compound can be mix | blended with the curable polyorganosiloxane composition of embodiment as an adhesive provision agent. Examples of the isocyanurate compound include 1,3,5-tris (N-trimethoxysilylpropyl) isocyanurate. From the viewpoint of compatibility with the composition, the amount of such an adhesion-imparting agent is preferably 0.01 to 5 parts by mass with respect to 100 parts by mass of component (A).

  Further, the curable polyorganosiloxane composition of the embodiment includes an inorganic filler, a pigment, a thixotropy imparting agent, a viscosity modifier for improving extrusion workability, Various additives such as fungicides, heat resistance improvers, flame retardants and the like can be blended as necessary within a range not impairing the effects of the present invention.

  Examples of inorganic fillers include fumed silica, calcined silica, precipitated silica, fumed titanium, and those whose surfaces have been hydrophobized with organochlorosilanes, polyorganosiloxanes, hexamethyldisilazane, etc. . In addition, calcium carbonate, organic acid surface-treated calcium carbonate, diatomaceous earth, ground silica, aluminosilicate, magnesia, alumina, and the like can be used. When mix | blending an inorganic filler, 100 mass parts or less are preferable with respect to 100 mass parts of (A) component, and, as for the compounding quantity, 50 mass parts or less are more preferable.

  In the curable polyorganosiloxane composition of the embodiment, the component (A), the component (B1), the component (B2), the component (C) that is blended as necessary, and the optional components described above are shielded from moisture. It is obtained by mixing in the state. The obtained composition has a viscosity of 20 to 1,000 mPa · s at 23 ° C. The viscosity is preferably 20 to 500 mPa · s. In addition, the curable polyorganosiloxane composition of the embodiment does not contain a solvent. Therefore, a solvent removal step is not required at the time of forming the cured film, and volatilization of the solvent does not cause deterioration of the working environment, and corrosion / deterioration of electric / electronic components and circuit boards on which they are mounted.

  The curable polyorganosiloxane composition obtained above can be used as a so-called one-packaging curable composition that is stored as it is in a closed container and is cured only by exposure to moisture in the air during use. . In addition, the curable polyorganosiloxane composition of the embodiment includes, for example, a main component mainly composed of component (A), (B1) a condensation reaction curing catalyst, (B2) a photoreaction initiator, and (C) a crosslinking component. It can also be used as a so-called multi-packaging curable composition, which is prepared by dividing into a curing agent containing an agent, appropriately divided into two or three separate containers, and stored in use. In addition, the order of mixing of each component is not specifically limited.

  Since the curable polyorganosiloxane composition of the present invention has a sufficiently low viscosity of 20 to 1,000 mPa · s at 23 ° C. as described above, the coating property is good and it is usually as it is without being diluted with a solvent. The coating method can be used. The coating film is rapidly cured at room temperature by coming into contact with moisture in the air. In addition, since the component (A1) and the like contained in the composition have a (meth) acryloxyalkyl group, the composition can be further cured by irradiation with ultraviolet rays having a wavelength capable of causing a radical reaction. it can. For example, after irradiating with ultraviolet rays having a predetermined wavelength, it is preferable to use a method such as contacting with moisture in the air at room temperature, and curing by using both ultraviolet irradiation and standing at room temperature.

  As a device (lamp) for irradiating ultraviolet rays having a wavelength capable of causing radical reaction on a (meth) acryloxyalkyl group, for example, a high pressure mercury lamp (UV-7000), a metal halide lamp (MHL-250) manufactured by USHIO INC. , MHL-450, MHL-150, MHL-70), metal halide lamp (JM-MTL 2KW) manufactured by Korea JM tech, ultraviolet irradiation lamp (OSBL360) manufactured by Mitsubishi Electric Corporation, ultraviolet irradiation manufactured by Nippon Battery Co., Ltd. Machine (UD-20-2), Toshiba Corporation fluorescent lamp (FL-20BLB)], Fusion H valve, H plus valve, D valve, Q valve, M valve and the like.

The composition of the present invention has good curability. That is, a cured film having excellent hardness is formed with a small amount of ultraviolet irradiation. The amount of ultraviolet irradiation may be a 500 mJ / cm ² or more, preferably 500~15000mJ / cm ^2, more preferably 1000~5000mJ / cm ^2, even more preferably at 1500~3500mJ / cm ² .

  The hardness (TYPE A) of the cured film obtained from the composition of the present invention is as high as 50 or more, and is excellent in electrical and mechanical properties, particularly scratch resistance. Further, even in a long-term test under severe conditions, the cured coating formed on the substrate is free from cracks, blisters, peeling, etc., and the adhesion durability is good.

  Therefore, the curable polyorganosiloxane composition of the present invention is useful for applications such as coating materials and potting materials for electric and electronic devices, and particularly, electric and electronic parts such as conformal coating agents and the like mounted thereon. Suitable for protecting the surface of the circuit board. Specifically, for example, a wiring board in which electrodes and wirings made of ITO, copper, aluminum, silver, gold, etc. are formed on a board made of epoxy resin, phenol resin, polyimide resin, etc. or a board made of ceramic such as alumina. In addition, it is suitably used as a coating material for electrodes, wiring, and the like in electrical and electronic equipment equipped with semiconductor devices such as ICs, electronic components such as resistors and capacitors.

  When the curable polyorganosiloxane composition of the present invention is used as an electrode for a wiring board or a coating material for a wiring, a dipping method, a brush coating method, a spray method, a dispensing method, or the like can be used as a coating method. The thickness of the layer is usually 0.01 to 3 mm, preferably 0.05 to 2 mm. If the thickness is less than 0.01 mm, scratch resistance may not be sufficiently obtained. On the other hand, if the thickness exceeds 3 mm, not only the effect can be obtained, but also it takes time to harden the inside, which is uneconomical.

  Next, the electric / electronic device of the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view showing an example of an electric / electronic device according to the present invention.

  The electric / electronic device 1 according to the embodiment includes a wiring board 2 in which a wiring 2b made of a conductor such as a copper foil is formed on an insulating board 2a such as a glass epoxy board. An electrical / electronic component such as an IC package 3 or a capacitor 4 is mounted at a predetermined position on one main surface of the wiring board 2 and is electrically connected to the wiring 2b. The connection between the IC package 3 or the capacitor 4 and the wiring 2b is such that the lead terminals 3a and 4a of these components are inserted into the component holes (not shown) of the wiring substrate 2 and are joined via solder or the like. It is done by doing.

  A cured film 5 made of a cured product of the curable polyorganosiloxane composition of the present invention is formed on the component mounting surface of the wiring board 2 so as to cover the upper surfaces of the IC package 3 and the capacitor 4. .

  In the electrical / electronic device 1 of such an embodiment, the wiring board 2 and the electrical / electronic components mounted on the main surface thereof are covered with the cured coating 5 that has excellent scratch resistance and is less likely to be peeled off or turned up due to friction. So it is highly reliable.

  EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples, but these examples do not limit the scope of the present invention.

Each of the following units represents a siloxane unit represented by each formula.
[D] unit ………… (CH ₃ ) ₂ SiO _2/2
[T] unit ………… (CH ₃ ) SiO _3/2
[T ^ac ] unit …… CH ₂ ═CH—C (═O) —O— (CH ₂ ) ₃ SiO _3/2
[D ₁₂ ] unit ………… [(CH ₃ ) ₂ SiO _2/2 ] ₁₂
[D ₃₀ ] unit ………… [(CH ₃ ) ₂ SiO _2/2 ] ₃₀
[D ₆₀ ] unit ………… [(CH ₃ ) ₂ SiO _2/2 ] ₆₀
[M ^OM ] unit ………… (CH ₃ ) (CH ₃ O) ₂ SiO _1/2
[ ^Mac units] …………
Si (OCH ₃ ) ₂ [(CH ₂ ) ₃ —O—C (O) CH═CH ₂ ] O _1/2
[M ^mac units] …………
Si (OCH ₃ ) ₂ [(CH ₂ ) ₃ —O—C (O) C (CH ₃ ) ═CH ₂ ] O _1/2
[M ^D12 ] Unit …………
_{(CH 3 O) (CH 3} ) SiO - [(CH 3) 2 SiO 2/2] 12 -Si (OCH 3) 2 (CH 3)
[M ^{(ac) (D12)} ] unit …………
_{(CH 3 O) [CH 2} = CHC (O) -O- (CH 2) 3] SiO - [(CH 3) 2 SiO 2/2] 12 -Si (OCH 3) 2 [(CH 2) 3 - O—C (O) CH═CH ₂ ]
[M ^{(ac) (D30)} ] unit …………
_{(CH 3 O) [CH 2} = CHC (O) -O- (CH 2) 3] SiO - [(CH 3) 2 SiO 2/2] 30 -Si (OCH 3) 2 [(CH 2) 3 - O—C (O) CH═CH ₂ ]
[M ^{(ac) (D60)} ] unit …………
_{(CH 3 O) [CH 2} = CHC (O) -O- (CH 2) 3] SiO - [(CH 3) 2 SiO 2/2] 60 -Si (OCH 3) 2 [(CH 2) 3 - O—C (O) CH═CH ₂ ]

  “Parts” means “parts by mass”, “%” means “% by mass”, and all viscosities are values at 23 ° C. and 50% RH (relative humidity). . Moreover, a weight average molecular weight (Mw) is the value which measured and measured polystyrene using the gel permeation chromatography (GPC) apparatus (Tosoh Corporation make, apparatus name; HLC-8220 GPC) which uses toluene as a solvent.

  As the component (A1) used in Examples and Comparative Examples, polyorganosiloxanes (A1-1) to (A1-12) having a three-dimensional network structure having an alkoxy group at the terminal were synthesized as follows.

Synthesis Example 1 (Synthesis of (A1-1))
Into a 5 L separable flask, 1410 g of toluene and 135 g of methanol were charged, and while stirring, 40 g of methyltrichlorosilane, 850 g of methyltrimethoxysilane, 352 g of acryloxypropyltrimethoxysilane, α, ω-dihydroxydimethylpolysiloxane (D ₁₂ ) (Mw: 917) 153 g of the mixture was added.
“Α, ω-dihydroxydimethylpolysiloxane (D ₁₂ )” is a structure in which one hydroxyl group is bonded to each silicon atom at both ends of a polymer molecule in which 12 D units are linearly bonded. Of polysiloxane. Hereinafter, similarly, a polysiloxane having hydroxyl groups at both ends and having p bonds of D units is denoted as α, ω-dihydroxydimethylpolysiloxane (D _p ).

  Subsequently, after raising the temperature in a flask to 35 degreeC using a mantle heater, 510 g of city water was dripped in the flask. The liquid temperature after completion of the dropwise addition was raised to 60 ° C. After heating and refluxing for 2 hours, 510 g of city water was further added for liquid separation, and the upper water / methanol / HCL layer was discarded.

  After dehydrating the lower resin / toluene layer at normal pressure, excess toluene was distilled off by stripping under reduced pressure. Thus, polyorganosiloxane (A1-1a) having a silanol group at the terminal and a three-dimensional network structure was obtained. Mw of the polyorganosiloxane (A1-1a) was 4860.

  Next, 210 g of polyorganosiloxane (A1-1a) having a three-dimensional network structure having a silanol group at the terminal obtained above was charged into a 1 L separable flask, 90 g of methyltrimethoxysilane was added, and the mixture was stirred at room temperature for 5 minutes. After stirring, 2.1 g of diisobutylamine was added while stirring and stirring was performed for 5 minutes at room temperature. Then, 0.76 g of formic acid was added and stirring was performed for 5 minutes at room temperature, and then the temperature in the flask was adjusted. The temperature was raised to 80 ° C., and stirring was performed for 30 minutes.

  A methanol removal reaction occurred between the silanol group of the polyorganosiloxane (A1-1a) and the methoxy group of methyltrimethoxysilane, and methanol was by-produced. By-product methanol was removed from the flask using a drain tube. After stirring with heating at 80 ° C. for 6 hours, the mixture was cooled to room temperature. And it was confirmed by IR spectrum measurement that the absorption peak of the silanol group disappeared. Subsequently, excess methyltrimethoxysilane was distilled out of the system by distillation under reduced pressure to obtain polyorganosiloxane (A1-1) having a terminal blocked with a methoxysilyl group.

When the composition and structure of the polyorganosiloxane (A1-1) thus obtained were examined by ¹ H-NMR and ²⁹ Si-NMR, the average composition formula: (CH ₃ ) _1.05 (OCH ₃ ) _{0.09 (CH 2 = CHC (O)} O (CH 2) 3) was found to be polyorganosiloxane three-dimensional network structure having a 0.14 SiO _.1.36. Moreover, Mw of polyorganosiloxane (A1-1) was 5530.
From these data, it is estimated that polyorganosiloxane (A1-1) has an average unit formula: [T] _40.91 [T ^ac ] _9.44 [D ₁₂ ] _1.05 [M ^OM ] _3.125. Is done.

Synthesis Example 2 (Synthesis of (A1-2))
155 g of acryloxypropyltrimethoxysilane was added to 210 g of the three-dimensional network structure polyorganosiloxane (A1-1a) having a silanol group at the terminal obtained in Synthesis Example 1, and reacted in the same manner as in Synthesis Example 1 to produce polyorganosiloxane. Siloxane (A1-2) was obtained.
Note that “obtained in Synthesis Example 1” means “obtained by performing the same operation as in Synthesis Example 1.” Hereinafter, “obtained by performing the same operation as in synthesis example x” will be referred to as “obtained in synthesis example x”.
Mw and average unit formula of the obtained polyorganosiloxane (A1-2) are shown below.
Mw: 5980
Average unit formula: [T] _40.91 [T ^ac ] _9.44 [D ₁₂ ] _1.05 [M ^ac ] _3.87

Synthesis Example 3 (Synthesis of (A1-3))
To 210 g of the polyorganosiloxane (A1-1a) having a silanol group at the terminal obtained in Synthesis Example 1, 90 g of α, ω-dihydroxydimethylpolysiloxane (D ₁₂ ) (Mw: 917) and methyltri 90 g of methoxysilane was added and reacted in the same manner as in Synthesis Example 1 to obtain polyorganosiloxane (A1-3).
Mw and average unit formula of the obtained polyorganosiloxane (A1-3) are shown below.
Mw: 6330
Average unit formula: [T] _40.91 [T ^ac ] _9.44 [D ₁₂ ] _1.05 [M ^D12 ] _0.995

Synthesis Example 4 (Synthesis of (A1-4))
The polyorganosiloxane (A1-1a) having a three-dimensional network structure having a silanol group at the terminal obtained in Synthesis Example 1 is added to 90 g of α, ω-dihydroxydimethylpolysiloxane (D ₁₂ ) (Mw: 917) and acryloxy. 155 g of propyltrimethoxysilane was added and reacted in the same manner as in Synthesis Example 1 to obtain polyorganosiloxane (A1-4).
Mw and average unit formula of the obtained polyorganosiloxane (A1-4) are shown below.
Mw: 6580
Average unit ^{_{formula: [T] 40.91 [T ac}} ] 9.44 [D 12] 1.05 [M (ac) (D12)] 1.024

Synthesis Example 5 (Synthesis of (A1-5))
Charge amounts of starting materials methyltrichlorosilane, methyltrimethoxysilane, acryloxypropyltrimethoxysilane, and α, ω-dihydroxydimethylpolysiloxane (D ₁₂ ) (Mw: 917), and the obtained terminal silanol groups A polyorganosiloxane (A1-5) was obtained in the same manner as in Synthesis Example 1 except that the amount of methyltrimethoxysilane reacted with the polyorganosiloxane having a three-dimensional network structure was changed.
Mw and average unit formula of the obtained polyorganosiloxane (A1-5) are shown below.
Mw: 5390
Average unit ^{_{formula: [T] 33.14 [T ac}} ] 9.04 [D 12] 1.507 [M OM] 3.542

Synthesis Example 6 (Synthesis of (A1-6))
155 g of acryloxypropyltrimethoxysilane is added to 210 g of the three-dimensional network structure polyorganosiloxane having a silanol group at the terminal obtained in Synthesis Example 5, and reacted in the same manner as in Synthesis Example 1 to react with polyorganosiloxane (A1-6). )
Mw and average unit formula of the obtained polyorganosiloxane (A1-6) are shown below.
Mw: 5710
Average unit ^{_{formula: [T] 33.14 [T ac}} ] 9.04 [D 12] 1.507 [M ac] 3.402

Synthesis Example 7 (Synthesis of (A1-7))
Hydrolysis and condensation of 714 g of methyltrimethoxysilane, 40 g of methyltrichlorosilane, 350 g of acryloxypropyltrimethoxysilane, and 230 g of α, ω-dihydroxydimethylpolysiloxane (D ₁₂ ) (Mw: 917) in the same manner as in Synthesis Example 1. Thus, a polyorganosiloxane having a three-dimensional network structure having a silanol group at the terminal was synthesized.

Then, 210 g of polyorganosiloxane having a three-dimensional network structure having a silanol group at the terminal obtained was added 90 g of α, ω-dihydroxydimethylpolysiloxane (D ₁₂ ) (Mw: 917) and 155 g of acryloxypropyltrimethoxysilane. In addition, the reaction was conducted in the same manner as in Synthesis Example 1 to obtain polyorganosiloxane (A1-7).
Mw and average unit formula of the obtained polyorganosiloxane (A1-7) are shown below.
Mw: 5910
Average unit ^{_{formula: [T] 34.06 [T ac}} ] 9.3 [D 12] 1.55 [M (ac) (D12)] 0.546

Synthesis Example 8 (Synthesis of (A1-8))
Hydrolysis and condensation of 713 g of methyltrimethoxysilane, 40 g of methyltrichlorosilane, 350 g of acryloxypropyltrimethoxysilane, and 243 g of α, ω-dihydroxydimethylpolysiloxane (D ₃₀ ) (Mw: 2430) in the same manner as in Synthesis Example 1. Thus, a polyorganosiloxane having a three-dimensional network structure having a silanol group at the terminal was synthesized.

Next, 243 g of α, ω-dihydroxydimethylpolysiloxane (D ₃₀ ) (Mw: 2430) and 155 g of acryloxypropyltrimethoxysilane were added to 210 g of the polyorganosiloxane having a three-dimensional network structure having a silanol group at the terminal. In the same manner as in Synthesis Example 1, polyorganosiloxane (A1-8) was obtained.
Mw and average unit formula of the obtained polyorganosiloxane (A1-8) are shown below.
Mw: 6370
Average unit ^{_{formula: [T] 34.2 [T ac}} ] 9.33 [D 30] 0.62 [M (ac) (D30)] 0.336

Synthesis Example 9 (Synthesis of (A1-9))
713 g of methyltrimethoxysilane, 40 g of methyltrichlorosilane, 350 g of acryloxypropyltrimethoxysilane, and 233 g of α, ω-dihydroxydimethylpolysiloxane (D ₆₀ ) (Mw: 4660) were hydrolyzed and condensed in the same manner as in Synthesis Example 1. Thus, a polyorganosiloxane having a three-dimensional network structure having a silanol group at the terminal was synthesized.

Next, 450 g of α, ω-dihydroxydimethylpolysiloxane (D ₆₀ ) (Mw: 4660) and 155 g of acryloxypropyltrimethoxysilane were added to 210 g of the resulting polyorganosiloxane having a silanol group at the terminal. In the same manner as in Synthesis Example 1, polyorganosiloxane (A1-9) was obtained.
Mw and average unit formula of the obtained polyorganosiloxane (A1-9) are shown below.
Mw: 7210
Average unit ^{_{formula: [T] 36.9 [T ac}} ] 10.06 [D 60] 0.335 [M (ac) (D60)] 0.33

Synthesis Example 10 (Synthesis of (A1-10))
40 g of methyltrimethoxysilane and 1600 g of methyltrichlorosilane were hydrolyzed and condensed in the same manner as in Synthesis Example 1 to synthesize a polyorganosiloxane having a three-dimensional network structure having a silanol group at the terminal.

Next, 165 g of methacryloxypropyltrimethoxysilane was added to 210 g of the polyorganosiloxane having a three-dimensional network structure having a silanol group at the terminal obtained, and reacted in the same manner as in Synthesis Example 1 to obtain polyorganosiloxane (A1-10). Obtained.
Mw and average unit formula of the obtained polyorganosiloxane (A1-10) are shown below.
Mw: 7860
Average unit formula: [T] _78.4 [M ^mac ] _9.9

Synthesis Example 11 (Synthesis of (A1-11))
155 g of acryloxypropyltrimethoxysilane is added to 210 g of a three-dimensional network structure polyorganosiloxane having a silanol group at the terminal obtained in Synthesis Example 10 and reacted in the same manner as in Synthesis Example 1 to react with polyorganosiloxane (A1-11). )
Mw and average unit formula of the obtained polyorganosiloxane (A1-11) are shown below.
Mw: 7230
Average unit formula: [T] _78.4 [M ^ac ] _9.78

Synthesis Example 12 (Synthesis of (A1-12))
1376 g of acryloxypropyltrimethoxysilane was hydrolyzed and condensed in the same manner as in Synthesis Example 1 to synthesize a polyorganosiloxane having a three-dimensional network structure having a silanol group at the terminal.
Next, 45 g of methyltrimethoxysilane was added to 210 g of the three-dimensional network structure polyorganosiloxane having a silanol group at the terminal thus obtained, and reacted in the same manner as in Synthesis Example 1 to obtain polyorganosiloxane (A1-12). . Mw and average unit formula of the obtained polyorganosiloxane (A1-12) are shown below.
Mw: 6910
Average unit formula: [T ^ac ] _37.7 [M ^OM ] _4.59

From the average unit formula, the polyorganosiloxane of (A1-1) to (A1-9) is one polymer unit (poly D1) selected from [D ₁₂ ] unit, [D ₃₀ ] unit and [D ₆₀ ] unit. It is understood that the unit is contained in the three-dimensional network structure. (A1-10) to (A1-12) are terminal organomethoxysilyl group-containing polyorganosiloxanes having a three-dimensional network structure having an acryloxypropyl group or a methacryloxypropyl group, but having the polymer unit in the molecule However, the polymer unit does not form a part of a three-dimensional network structure.

[Example 1]
Linear polydimethylsiloxane (viscosity: 15 mPa · s) in which (A2-1) both molecular chain ends are blocked with trimethoxysilyl groups on 60 parts of the polyorganosiloxane (A1-1) obtained in Synthesis Example 1 40 parts, (C-1) 2 parts of methyltrimethoxysilane, (C-4) 3 parts of acryloxypropyltrimethoxysilane, (B1) 2 parts of diisopropoxy-bis (ethylacetylacetate) titanium, 1, 3 , 5-tris (N-trimethoxysilylpropyl) isocyanurate 0.2 part, (B2-1) IRUGACURE 819 0.1 part, (B2-2) IRUGACURE 184 0.4 part, respectively, under moisture blocking Were mixed uniformly in a dark place to obtain a polyorganosiloxane composition.

[Examples 2 to 10]
Each component shown in Table 1 was blended in the composition shown in the same table and mixed in the same manner as in Example 1 to obtain a polyorganosiloxane composition.

[Comparative Examples 1-8]
Each component shown in Table 2 was blended in the composition shown in the same table and mixed in the same manner as in Example 1 to obtain a polyorganosiloxane composition.

Each component described in Table 1 and Table 2 is as follows.
(A2) Component (A2-1) Linear polydimethylsiloxane in which both ends of the molecular chain are blocked with trimethoxysilyl groups (viscosity 15 mPa · s)
(A2-2) Linear polydimethylsiloxane in which both ends of the molecular chain are blocked with methacryloxypropyldimethoxysilyl groups (viscosity: 10 mPa · s)
(A2-3) Linear polydimethylsiloxane in which both molecular chain ends are blocked with methacryloxypropyldimethoxysilyl groups (viscosity 800 mPa · s)
(A2-4) Linear polydimethylsiloxane in which both ends of the molecular chain are blocked with acryloxypropyldimethoxysilyl groups (viscosity: 15 mPa · s)
(A2-5) Linear polydimethylsiloxane in which both ends of the molecular chain are blocked with acryloxypropyldimethoxysilyl groups (viscosity 1000 mPa · s)
(B1) Component (B1) Diisopropoxy-bis (ethylacetylacetate) Titanium (B2) Component (B2-1) IRUGACURE 819
(B2-2) IRUGACURE 184
(C) Component (C-1) Methyltrimethoxysilane (C-2) Methylvinyldimethoxysilane (C-3) Methacryloxypropyltrimethoxysilane (C-4) Acryloxypropyltrimethoxysilane (C-5) Acryloxypropyltrimethoxysilane partial hydrolysis condensate (viscosity 23 mPa · s)

  Next, various characteristics of the polyorganosiloxane compositions obtained in Examples 1 to 10 and Comparative Examples 1 to 8 were measured and evaluated by the methods shown below. The results are shown in Table 3 for Examples 1-10 and in Table 4 for Comparative Examples 1-8.

[viscosity]
The viscosity of the polyorganosiloxane composition was measured according to JIS K6249. A rotational viscometer (manufactured by Shibaura Semtec Co., Ltd., product name: Bismetron VDA-2) was used. Measurements were taken at 2.

[Tack Free Time]
The tack free time of the polyorganosiloxane composition was measured according to JIS K6249. The sample was placed flat in an aluminum petri dish with a thickness of 3 mm so that bubbles would not enter, and then the surface was lightly touched with a fingertip washed with ethyl alcohol. The time at which the sample did not adhere to the fingertip was defined as the tack free time (minutes).

[hardness]
<Hardness of UV curing + moisture curing>
The hardness of the polyorganosiloxane composition was measured as shown below according to JIS K6249. That is, after forming the polyorganosiloxane composition into a sheet having a thickness of 2 mm, the composition was irradiated with ultraviolet rays (irradiation amount: 5000 mJ / cm ² ) by an ultraviolet irradiation device (product name: metal halide UVL-4001M manufactured by Ushio Electric Co., Ltd.). Then, it was left to cure at 23 ° C. and 50% RH for 3 days. Three cured sheets thus obtained were stacked, and the hardness was measured with a durometer (TYPE A) and a micro hardness meter (manufactured by Kobunshi Keiki Co., Ltd., product name: M250).

<Hardness only for UV curing>
After the polyorganosiloxane composition is formed into a sheet having a thickness of 2 mm, it is cured by ultraviolet irradiation (irradiation amount: 5000 mJ / cm ² ) by an ultraviolet irradiation device (product name: metal halide UVL-4001M manufactured by Ushio Electric Co., Ltd.). I let you. Three sheets of the cured sheets thus obtained were stacked, and the hardness was measured with a durometer (TYPE A) and a micro hardness tester.
In addition, the surface state of the sheet after UV curing (such as tackiness and presence / absence of slime) was examined. “OK” was defined as a light touch on the surface with a fingertip and no tack.

<Hardness only for moisture curing>
The polyorganosiloxane composition was molded into a sheet having a thickness of 2 mm and then allowed to cure for 7 days in the dark at 23 ° C. and 50% RH. Three sheets of the cured sheets thus obtained were stacked, and the hardness was measured with a durometer (TYPE A) and a micro hardness tester.

[Hardness change]
The hardness of the sample after UV curing and then moisture curing was measured with a micro hardness tester after standing for 500 hours in an atmosphere of 150 ° C. and after standing for 500 hours in an atmosphere of 85 ° C. and 85% RH.

[Scratch resistance]
The polyorganosiloxane composition was applied to a comb-shaped electrode substrate (copper electrode, pattern width 0.316 mm) defined in JIS Z3197 (ISO 9455) at a thickness of 100 μm, and 2000 mJ / After irradiating with ultraviolet rays at a dose of cm ² , the coating film was cured by leaving it at 23 ° C. and 50% RH for 3 days. Next, a pencil hardness test was performed on the formed cured film according to JIS K5600-5-4 to evaluate scratch resistance. In the pencil hardness test, 2B and 4B pencils were used, a line was drawn with a load of 750 g, the subsequent state of the cured film was visually observed, and when the cured film was not turned up, it was evaluated as “OK”.

[Adhesion durability]
The polyorganosiloxane composition is applied to the surface of a substrate made of glass epoxy so that the length is 50 mm, the width is 10 mm, and the thickness is 1 mm, and the irradiation amount is 2000 mJ / cm ² using the ultraviolet irradiation device. After irradiating with ultraviolet rays, the mixture was allowed to stand at 23 ° C. and 50% RH for 3 days to be cured. The cured product thus formed was subjected to initial and (1) standing at 150 ° C. for 500 hours, (2) standing at 85 ° C. and 85% RH for 500 hours, and (3) a thermal cycle of −40 ° C. to 150 ° C. After applying 100 cycles, and (4) applying a thermal cycle of −40 ° C. to 150 ° C. for 200 cycles, the cured product was scraped from the surface of the substrate with a metal spatula. The state of peeling was examined. And the adhesion durability was evaluated according to the following criteria.

<Evaluation criteria>
OK: The cured product cannot be peeled off from the interface with the substrate, and the cured product is destroyed.
NG: A part of the cured product peels from the interface with the substrate.
Crack: A part of the cured product is peeled off from the interface with the substrate, and a crack or a crack occurs in a part of the cured product.

Tables 1-4 show the following.
The polyorganosiloxane compositions obtained in Examples 1 to 10 have a uniform and suitable viscosity for thin film coating, and also have high hardness (TYPE A and micro hardness) and good scratch resistance. Form a film. In addition, the cured films obtained using the polyorganosiloxane compositions of Examples 1 to 10 were not observed for cracks, cracks, blisters, peeling, etc. even in the observation of adhesiveness and appearance after being loaded. Good adhesion durability.

  On the other hand, in Comparative Examples 6-8, the polyorganosiloxane composition which has a viscosity suitable for thin film application was not obtained. Further, in Comparative Examples 1, 3, and 5, it was not possible to create a sheet capable of measuring hardness and the like. In Comparative Examples 2 and 4, although the sheet could be prepared, the hardness of the cured film was low and the scratch resistance was poor.

  The curable polyorganosiloxane of the present invention is useful for applications such as coating materials and potting materials for electrical and electronic equipment, and particularly as a conformal coating agent for electrical and electronic equipment in which electronic components are mounted on a substrate. Preferred.

  DESCRIPTION OF SYMBOLS 1 ... Electric / electronic device, 2 ... Wiring board, 3 ... IC package, 4 ... Capacitor, 5 ... Hardened film of curable polyorganosiloxane composition.

Claims (8)

A polyorganosiloxane having one or more (meth) acryloxyalkyl groups bonded to a silicon atom and two or more alkoxy groups and having a three-dimensional network structure, and having 5 or more and 100 or less bifunctional siloxanes (A1) three-dimensional network structure alkoxy group-containing polyorganosiloxane having a weight average molecular weight (Mw) of 2,000 to 100,000, comprising polymer units in which the units are linearly bonded in the three-dimensional network structure. Containing (A) 100 parts by mass of an alkoxy group-containing polyorganosiloxane mixture,
(B1) condensation reaction curing catalyst 0.0001-20 parts by mass;
(B2) A curable polyorganosiloxane composition containing 0.001 to 20 parts by mass of a photoreaction initiator that is an ultraviolet curing catalyst.   100 parts by mass of the (A) alkoxy group-containing polyorganosiloxane mixture is composed of 20 to 100 parts by mass of the (A1) three-dimensional network structure alkoxy group-containing polyorganosiloxane, and (A2) an alkoxy group bonded to a silicon atom and / or 2. The curable polyorganosiloxane composition according to claim 1, comprising 80 parts by mass or less of a polyorganosiloxane having a (meth) acryloxyalkyl group and a viscosity at 23 ° C. of 3 to 500 mPa · s.   The curable polyorganosiloxane composition according to claim 1 or 2, wherein the (B1) condensation reaction curing catalyst is an organic titanium compound.   The curable polyorganosiloxane composition according to any one of claims 1 to 3, wherein the (B2) photoreaction initiator is an alkylphenone compound and / or an acylphosphine oxide compound. Furthermore, the formula (C): R ¹ _c Si (OR ² ) _4-c
(R ¹ is independently an alkyl group having 1 to 6 carbon atoms, an alkenyl group having 2 to 6 carbon atoms, an aryl group having 6 to 12 carbon atoms, or a (meth) acryloxyalkyl group, R ² is independently an alkyl group having 1 to 6 carbon atoms, and c is 0, 1 or 2.) and / or a partial hydrolysis condensate thereof 0.1 The curable polyorganosiloxane composition according to any one of claims 1 to 4, which contains -15 parts by mass.   6. The curable polyorganosiloxane composition according to claim 5, wherein the silane compound has two or more alkoxy groups and one or more (meth) acryloxyalkyl groups.   The curable polyorganosiloxane composition according to any one of claims 1 to 6, wherein the composition is a coating composition for electrodes and / or wirings of electric / electronic devices.   An electric / electronic device comprising a film made of a cured product of the curable polyorganosiloxane composition according to any one of claims 1 to 7 on a surface of an electrode and / or a wiring.

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