JP2012144595A - Thermally conductive silicone composition and cured product excellent in transparency - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thermally conductive silicone composition that provides a cured product simultaneously having thermal conductivity, transparency, and flame retardancy, and to provide the cured product thereof.SOLUTION: The thermally conductive silicone composition includes surface-hydrophobized silica comprising a substrate silica comprising an SiOunit (unit Q) and a surface treatment agent applied and bonded to the surface of the substrate silica. The surface treatment agent is an organosilicon compound represented by general formula (X), wherein Ris either a monovalent organosiloxane group which may have a trifunctional branch but not a tetrafunctional branch and whose terminal bonded to a silicon atom is terminated by an oxygen atom, or a substituted or unsubstituted monovalent hydrocarbon group; Ris an alkyl group; and x is an integer of 1-3. The molar ratio (p/q) of the number (p) of the silicon atom constituting the surface treatment agent bonded to the surface of the substrate silica to the number (q) of the unit Q is in the range of 0.01-0.3.

Description

  The present invention generally relates to a heat-conductive silicone material having excellent transparency that can be interposed in a heat generation interface where transparency is required.

  LSI chips such as CPUs, driver ICs, and memories used in electronic devices such as personal computers, digital video discs, and mobile phones are becoming more and more themselves as performance, speed, size, and integration increase. Heat is generated, and the temperature rise of the chip due to the heat causes malfunction and destruction of the chip. Therefore, many heat dissipating methods for suppressing the temperature rise of the chip during operation and heat dissipating members used therefor have been proposed. However, the heat dissipating member that has been proposed so far is a composition in which a heat conductive inorganic filler is blended with a resin, or a cured product thereof, and is opaque. After being mounted on an electronic component as being opaque, it was necessary to remove it from the electronic component in order to confirm the name and part number of the component. In order to solve this problem, Japanese Utility Model Publication No. 62-28769 (Patent Document 1) has proposed a case-like heat dissipation member in which a notch or a window is provided on one surface of the case. However, there is a problem that the electrical insulation of the cut-out portion cannot be obtained, and Japanese Patent Application Laid-Open No. 8-17977 (Patent Document 2) proposes an electronic component case that achieves both transparency and electrical insulation. This is made of transparent silicone rubber in the cutout window. However, in this case, the transparent silicone rubber portion has a drawback that the heat conductivity is remarkably lower than that of other portions, and a heat spot is generated in that portion. In addition, if a window is provided in a part of the case, when attaching the case, the part with the window must be matched with the part on which the part number or the like of the part is written, and the efficiency of the attaching work is poor. If the entire case is transparent and has thermal conductivity, the part number can be confirmed no matter how it is attached, and no heat spot is generated.

  On the other hand, in recent years, the development of liquid crystal panel displays (LCDs) and light emitting diodes (LEDs) has been tremendous. Liquid crystal panel displays are becoming thinner and LEDs are becoming brighter. Even in these fields, there is a problem of heat generation, and the current situation is that the heat generated from the LCD and LED is released to the back side of the substrate. In addition, although a number of protective films are laminated on the LCD screen, there is no layer with heat dissipation performance. If a layer having heat dissipation performance can be laminated, heat can be radiated from the display portion, so that the temperature rise of the panel can be further suppressed. However, for that purpose, transparency is required while having heat dissipation performance. Moreover, if heat dissipation performance can be imparted to the sealing material and reflector material of the LED element, it can contribute to longer life without lowering the brightness. Therefore, transparency is still necessary while having heat dissipation performance.

Japanese Utility Model Publication No.62-28769 Japanese Patent Laid-Open No. 8-17977

  Then, in view of the said problem, this invention aims at providing the heat conductive silicone composition which gives the hardened | cured material which has heat conductivity, transparency, and a flame retardance, and its hardened | cured material.

  The inventors of the present invention are capable of high filling by using silica having a specific hydrophobized surface treatment, and have excellent thermal conductivity and flame retardancy while maintaining transparency, and curing thereof. It came to develop a thing.

That is, the present invention solves the above problems as follows:
(Α) Hydrophobized surface-treated silica composed of a base silica composed of SiO _1/2 units (Q units) and a surface treatment agent treated and bonded to the surface, and
(Β) A thermally conductive silicone composition containing a polyorganosiloxane component,
The surface treatment agent has the general formula (X):

(In the formula, R ¹ may have a trifunctional branch but does not have a tetrafunctional branch, is a monovalent organosiloxane group whose terminal bonded to a silicon atom is terminated with an oxygen atom, or Or a substituted or unsubstituted monovalent hydrocarbon group, R ² is an alkyl group, and x is an integer of 1 to ^3. )
An organosilicon compound represented by
The molar ratio (p / q) of the number (p) of silicon atoms constituting the surface treatment agent bonded to the surface of the base silica with respect to the number (q) of Q units is in the range of 0.01 to 0.3. A thermally conductive silicone composition is provided.

  The thermally conductive silicone composition of the present invention can provide a cured product having both thermal conductivity, transparency and flame retardancy. Therefore, it can be used as a heat radiating member even in a heat generating portion that requires transparency.

-About M, D, T, Q units-
Organopolysiloxane is composed of inorganic Si-O-Si bonds and organic groups bonded to silicon atoms. By changing the structure of the skeleton, the degree of polymerization, the type of organic groups, etc., each has various characteristics. Things are obtained. Therefore, in order to simplify the structure of the organopolysiloxane and the description of the present invention, the following symbols that are well known and commonly used by those skilled in the art are used. In each unit, the oxygen atom bonded adjacent to the silicon atom is assumed to be an oxygen atom that forms a siloxane bond (Si—O—Si), and ½ is shared by two silicon atoms sandwiching the oxygen atom. I think it has been.
M units:

D unit:

T unit:

Q unit:

  However, in these units, R represents a monovalent substituent.

-(Α) surface-treated silica-
-Base silica:
Base silica, that is, untreated silica consists essentially of Q units, but usually has many hydroxyl groups (silanol groups) on the surface, and the surface is hydrophilic.

・ Surface treatment agent:
The surface-treated silica used in the present invention is obtained by treating the base silica with the specific surface treatment agent represented by the general formula (X) to make the surface hydrophobic. The hydroxyl group inherent to the base silica reacts with the surface treatment agent to make the surface hydrophobic. Accordingly, the surface-treated silica exists in a state where the surface treatment agent is bonded to the surface of the base silica.

In the general formula (X), R ¹ may be a monovalent organosiloxane group which may have a trifunctional branch but does not have a tetrafunctional branch, and the terminal bonded to the silicon atom is terminated with an oxygen atom. Or a substituted or unsubstituted monovalent hydrocarbon group. Here, the trifunctional branch is a T-shaped branch formed in the main chain of the polyorganosiloxane by the presence of the T unit, and the tetrafunctional branch is formed in the main chain by the presence of the Q unit. Cruciform branch.

When R ¹ is the monovalent polyorganosiloxane group, the polyorganosiloxane chain is composed of M units, D units, T units, or a combination of two or more thereof.
Specifically, the organosilicon compound represented by the general formula (X) can be represented by the following general formulas (1) to (3).

式（１）〜（３）において、Ｒ^１及びＲ^２は一般式（Ｘ）について述べた通りである。

In the formulas (1) to (3), R ¹ and R ² are as described for the general formula (X).

In the case where R ¹ is an organopolysiloxane group, the main chain portion is usually basically composed of repetition of the D unit (where R is a monovalent organic group). The portion may contain the T unit (where R is a monovalent organic group) and a T-shaped branched structure.

When R ¹ is a monovalent organopolysiloxane group, the number of repeating siloxane units (degree of polymerization) is preferably 3-50. The lower limit of the degree of polymerization is preferably 3 or more, and the upper limit is more preferably 20 or less. If the number of repeating units exceeds 50, the surface of the base silica is covered with silicone, and dehydration condensation with silanol groups present on the surface of the base silica is difficult to proceed. Moreover, the particle diameter of the surface-treated silica obtained tends to be excessive.

When R ¹ is an unsubstituted or substituted monovalent hydrocarbon group, the organosilicon compound represented by the general formula (X) is an alkoxysilane. Examples of the unsubstituted or substituted monovalent hydrocarbon group include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a tert-butyl group, a pentyl group, a neopentyl group, a hexyl group, a heptyl group, and an octyl group. Group, nonyl group, decyl group, dodecyl group and other alkyl groups, cyclopentyl group, cyclohexyl group, cycloheptyl group and other cycloalkyl groups, phenyl group, tolyl group, xylyl group, xylyl group, naphthyl group, biphenylyl group and other aryl groups, benzyl A hydrocarbon group such as an aralkyl group such as a group, phenylethyl group, phenylpropyl group or methylbenzyl group; and a part or all of the hydrogen atoms to which the carbon atoms of these hydrocarbon groups are bonded are fluorine, chlorine, Substituted hydrocarbon groups substituted by halogen atoms such as bromine, cyano groups, etc., for example, chloromethyl groups 2-bromoethyl group, 3-chloropropyl group, 3,3,3-trifluoropropyl group, chlorophenyl group, fluorophenyl group, cyanoethyl group, 3,3,4,4,5,5,6,6,6- Nonafluorohexyl group etc. are mentioned. Among these, a typical one has 1 to 10 carbon atoms, and a particularly typical one has 1 to 6 carbon atoms, preferably a methyl group, an ethyl group, a propyl group, or a chloromethyl group. Group, bromoethyl group, 3,3,3-trifluoropropyl group, cyanoethyl group, etc., unsubstituted or substituted alkyl group having 1 to 3 carbon atoms and phenyl group, chlorophenyl group, fluorophenyl group, etc., unsubstituted or substituted Of the phenyl group.

R ² of the alkoxy group (OR ² ) is an alkyl group having 1 to 6 carbon atoms, preferably an alkyl group having 1 or 2 carbon atoms, such as a methyl group, an ethyl group, a propyl group, or an isopropyl group. Butyl group, isobutyl group, tert-butyl group, pentyl group, neopentyl group, and hexyl group.

There may be one or more alkoxy groups (OR ² ) bonded to the terminal silicon. The type of alkoxysilane can be selected from one or more. Further, when an alkoxysilane having two or more alkoxy groups at the terminal is used, it can be further treated with another alkoxysilane, and a surface-treated silica having high hydrophobicity can be obtained. The extent of the treatment can be calculated from the area ratio of gas chromatography by, for example, applying potassium hydroxide to the surface-treated silica to cleave the siloxane bond and all ethoxysilanize. (Calculated by this method in the examples of the present application).

  Specific examples of the surface treatment agent represented by the general formulas (1) to (3) include the following compounds.

The surface treating agent represented by the general formula (X) described above can be used alone or in combination of two or more.
・ Surface treatment silica:
The ratio of the base silica composed of Q units and the surface treatment agent present on the surface is the surface treatment agent bonded to the surface of the base silica with respect to the number (q) of Q units constituting the base silica. The molar ratio (p / q) of the number (p) of the silicon atoms constituting is in the range of 0.01 to 0.3. The larger the value of p / q, the more surface treatment agent is present on the silica surface, and it can be said that the silica has a higher degree of treatment. When p / q is smaller than 0.01, the degree of processing becomes insufficient, the filling property and dispersibility are poor, and the transparency cannot be maintained. Further, since the T unit is bulkier than the M unit, the silica surface can be protected more when the T unit is larger. For example, even if silanol groups remain on the surface of the surface-treated silica, the T unit is covered with the silanol groups, so that a hydrophobic effect can be obtained. On the other hand, when the molar ratio exceeds 0.3, the particle size of silica increases, and transparency cannot be ensured.

  The average particle diameter of the surface-treated silica is a value measured using a microtrack method. The average particle size needs to be 20 nm or more and 200 nm or less, preferably 20 nm or more and 150 μm or less, more preferably 20 nm or more and 120 nm or less. This is because if the average particle size is too large, transparency cannot be ensured even if it is well dispersed in silicone. On the other hand, when the average particle size is small, the transparency is increased, but the surface area of the silica is increased, the filling property is lowered, and it is difficult to achieve good thermal conductivity.

  As a typical production method of surface-treated silica, hydrocarbyloxysilane, typically, hydrophilic sol-gel silica fine particles obtained by hydrolytic condensation of tetramethoxysilane, the above-mentioned general formula of surface treatment agent is used. It is obtained by acting an organosilicon compound represented by (X).

-Silicone composition-
The thermally conductive silicone composition of the present invention is
(Α) Hydrophobized surface-treated silica composed of a base silica composed of SiO _1/2 units (Q units) and a surface treatment agent treated and bonded to the surface, and
(Β) A thermally conductive silicone composition containing a polyorganosiloxane component,
The surface treatment agent has the general formula (X):

(In the formula, R ¹ may have a trifunctional branch but does not have a tetrafunctional branch, is a monovalent organosiloxane group whose terminal bonded to a silicon atom is terminated with an oxygen atom, or Or a substituted or unsubstituted monovalent hydrocarbon group, R ² is an alkyl group, and x is an integer of 1 to ^3. )
An organosilicon compound represented by
The molar ratio (p / q) of the number (p) of silicon atoms constituting the surface treatment agent bonded to the surface of the base silica with respect to the number (q) of Q units is in the range of 0.01 to 0.3. It is a heat conductive silicone composition characterized by the above-mentioned.

The silicone composition contains (β) an organopolysiloxane component as another essential component in addition to the surface-treated silica as the component (α). Addition of the surface-treated silica of the component (α) to 100 parts by weight of the total organopolysiloxane component (not containing the surface-treating agent constituting the component (α)) contained in the composition The amount is preferably 100 to 500 parts by mass in terms of good transparency, thermal conductivity and flame retardancy. The lower limit of the addition amount is more preferably 200 parts by mass or more, and still more preferably 300 parts by mass or more. Further, the upper limit of the addition amount is more preferably 400 parts by mass or less, and further preferably 350 parts by mass or less. Moreover, when too large, the viscosity of a composition will become high too much and it will become poor in a moldability.
The thermally conductive silicone composition of the present invention is curable, and a polyorganosiloxane component (β) is selected according to the type of curing reaction, and a curing agent and a catalyst are blended as necessary. Hereinafter, each type of curing reaction of the composition will be described in detail.

-Kind by the hardening type of a silicone composition The hardening type of the heat conductive silicone composition of this invention is not specifically limited. A well-known thing can be used. Specific examples thereof include organic peroxide curable, addition curable, radiation curable, and condensation curable silicone compositions. Addition curability is preferred.

Examples of the radiation curable silicone composition include an ultraviolet curable silicone composition and an electron beam curable silicone composition.
Examples of the addition curing reactive silicone composition include a reaction (hydrosilylation addition reaction) in the presence of the above-mentioned linear organopolysiloxane having an alkenyl group, an organohydrogenpolysiloxane, and a platinum group metal catalyst. Mention may be made of silicone compositions that cure.

  Examples of organic peroxide-curable silicone compositions include linear organopolysiloxanes having an alkenyl group such as a vinyl group at one or both of the molecular chain terminal (one terminal or both terminals) and the molecular chain non-terminal. Mention may be made of a silicone composition which cures by radical polymerization of siloxane in the presence of an organic peroxide.

  As an ultraviolet curable silicone composition, the silicone composition hardened | cured with the energy of the ultraviolet-ray with a wavelength of 200-400 nm is mentioned, for example. In this case, the curing mechanism is not particularly limited. Specific examples thereof include an acrylic silicone composition containing an organopolysiloxane having an acrylic group or a methacryl group and a photopolymerization initiator, an organopolysiloxane having a mercapto group-containing organopolysiloxane and an alkenyl group such as a vinyl group, and light. A mercapto-vinyl addition polymerization silicone composition containing a polymerization initiator, an addition reaction silicone composition using the same platinum group metal catalyst as the thermosetting addition reaction type, an organopolysiloxane containing an epoxy group, and Examples thereof include a cationic polymerization type silicone composition containing an onium salt catalyst, and any of them can be used as an ultraviolet curable reactive silicone composition.

  As the electron beam curing reactive silicone composition, any silicone composition that cures by radical polymerization that is initiated by irradiating an electron beam to an organopolysiloxane having a radical polymerizable group can be used.

  Examples of the condensation-curing reactive silicone composition include a silanol-blocked organopolysiloxane and an organohydrogenpolysiloxane or a hydrolyzable silane such as tetraalkoxysilane or organotrialkoxysilane and / or a partially hydrolyzed condensate thereof. Is a silicone composition that cures by reacting in the presence of a condensation reaction catalyst such as an organotin catalyst, or both ends are trialkoxy groups, dialkoxyorgano groups, trialkoxysiloxyethyl groups, dialkoxyorganosiloxyethyl groups, etc. Examples thereof include a silicone composition that is cured by reacting the organopolysiloxane blocked with the above in the presence of a condensation reaction such as an organotin catalyst.

  Hereinafter, typical examples of each reactive silicone composition will be described in detail.

Organic peroxide curing reaction type silicone composition:
Specifically, as the organic peroxide curing reaction type silicone composition, for example, in addition to the surface treatment agent,
(A) an organopolysiloxane containing at least two alkenyl groups bonded to silicon atoms,
(B) an organic peroxide and, as an optional component, (c) an organohydrogenpolysiloxane containing at least two hydrogen atoms bonded to silicon atoms (ie, SiH groups), an alkenyl group in the fully curable silicone composition An amount in which the amount of hydrogen atoms bonded to silicon atoms in the component (c) is 0.1 to 2 mol per mol;
An organic peroxide curing reaction type silicone composition containing

-(A) component The organopolysiloxane of the (a) component is a base polymer of an organic peroxide curing reaction type silicone composition. The degree of polymerization of the organopolysiloxane of component (a) is not particularly limited, and as component (a), liquid organopolysiloxanes at 25 ° C. to raw rubber-like organopolysiloxane can be used, but the average degree of polymerization is preferred. An organopolysiloxane of 50 to 20,000, more preferably 100 to 10,000, and still more preferably about 100 to 2,000 is preferably used. The organopolysiloxane of component (a) is basically composed of repeating diorganosiloxane units (R ⁴ ₂ SiO _2/2 units) from the viewpoint of easy availability of raw materials, A linear structure having no branching, in which both ends of the molecular chain are blocked with a triorganosiloxy group (R ⁴ ₃ SiO _1/2 ) or a hydroxydiorganosiloxy group ((HO) R ⁴ ₂ SiO _1/2 unit), Alternatively, the molecular chain has a cyclic structure having no branch, consisting of repeating diorganosiloxane units, but may partially contain a branched structure such as a trifunctional siloxane unit or SiO ₂ unit. Here, R ⁴ is as defined in formula (4) described below.

As the component (a), for example, the following average composition formula (4):
R ⁴ _a SiO _{(4-a) / 2} (4)
Wherein R ⁴ represents the same or different unsubstituted or substituted monovalent hydrocarbon group having 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, and 50 to 99 mol% of R ⁴ is alkenyl. A is a positive number in the range of 1.5 to 2.8, more preferably 1.8 to 2.5, and even more preferably 1.95 to 2.05. Organopolysiloxanes having at least two alkenyl groups in the molecule are used.

Specific examples of R ⁴ include methyl groups, ethyl groups, propyl groups, butyl groups, pentyl groups, hexyl groups and other alkyl groups; phenyl groups, tolyl groups, xylyl groups, naphthyl groups and other aryl groups; cyclopentyl groups. A cycloalkyl group such as a cyclohexyl group; an alkenyl group such as a vinyl group, an allyl group, a propenyl group, an isopropenyl group, and a butenyl group; a part or all of the hydrogen atoms of these hydrocarbon groups are halogens such as fluorine, bromine, and chlorine A group substituted with an atom, a cyano group or the like, for example, a chloromethyl group, a chloropropyl group, a bromoethyl group, a trifluoropropyl group, a cyanoethyl group, and the like can be mentioned. From the viewpoint of high purity, it is preferably composed only of a hydrocarbon group.

In this case, at least two of R ⁴ are alkenyl groups (particularly alkenyl groups having preferably 2 to 8, more preferably 2 to 6 carbon atoms). The content of the alkenyl group is in the total organic group bonded to the silicon atom (that is, in the unsubstituted or substituted all monovalent hydrocarbon group represented by R ⁴ in the average composition formula (4)), preferably 50. It is -99 mol%, Most preferably, it is 75-95 mol%. When the organopolysiloxane of component (a) has a linear structure, the alkenyl group is bonded to a silicon atom only in one of the molecular chain terminal and the non-molecular chain terminal, and both of them are silicon. It may be bonded to an atom.

.. (b) component (b) component is an organic peroxide used as a catalyst for accelerating the crosslinking reaction of component (a) in the organic peroxide curing reaction type organopolysiloxane composition. As the component (b), conventionally known organic peroxides can be used as long as the crosslinking reaction of the component (a) can be promoted. Specific examples thereof include benzoyl peroxide, 2,4-dichlorobenzoyl peroxide, p-methylbenzoyl peroxide, o-methylbenzoyl peroxide, 2,4-dicumyl peroxide, 2,5- Dimethyl-bis (2,5-t-butylperoxy) hexane, di-t-butylperoxide, t-butylperbenzoate, 1,1-bis (t-butylperoxycarboxy) hexane, etc. However, it is not limited to these.

  The amount of component (b) added is an effective amount as a catalyst for promoting the crosslinking reaction of component (a). (A) Preferably it is 0.1-10 mass parts with respect to 100 mass parts of components, More preferably, it can be set as the range of 0.2-2 mass parts. When the added amount is less than 0.1 parts by mass with respect to 100 parts by mass of component (a), it takes a long time to cure, which is economically disadvantageous. Further, if the amount added is more than 10 parts by mass with respect to 100 parts by mass of component (a), foaming derived from component (b) occurs, and the strength and heat resistance of the cured reaction product are adversely affected. Receive.

.. (c) Component (c), which is an optional component, is an organohydrogenpolysiloxane having at least two hydrogen atoms (SiH groups) bonded to silicon atoms (usually 2 to 200), preferably 3 or more (Usually 3 to 100). (A) The component alone can be cured by adding the component (b) and heating, but by adding the component (c), compared to the case of the component (a) alone, ) Since it easily reacts with the component, it can be cured at a lower temperature and in a shorter time. The molecular structure of the component (c) is not particularly limited. For example, any conventionally produced organohydrogenpolysiloxane such as linear, cyclic, branched, and three-dimensional network (resinous) can be used as the component (c). Can be used as When the component (c) has a linear structure, the SiH group is bonded to the silicon atom only in one of the molecular chain terminal and the non-molecular chain terminal, or both. Also good. The number of silicon atoms in one molecule (or the degree of polymerization) is usually 2 to 300, preferably about 4 to 150, and the organohydrogenpolysiloxane that is liquid at room temperature (25 ° C.) (C) It can use preferably as a component.

As the component (c), for example, the following average composition formula (5):
R ⁵ _b H _c SiO _{(4-b-c) / 2} (5)
(In the formula, R ⁵ is a monovalent hydrocarbon group having 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, which does not contain the same or different unsubstituted or substituted aliphatic unsaturated bond, and b And c are preferably 0.7 ≦ b ≦ 2.1, 0.001 ≦ c ≦ 1.0, and 0.8 ≦ b + c ≦ 3.0, more preferably 1.0 ≦ b ≦ 2.0, (It is a positive number satisfying 0.01 ≦ c ≦ 1.0 and 1.5 ≦ b + c ≦ 2.5.)
The organohydrogenpolysiloxane shown by these is used. Examples of R ⁵ include the same groups as R ⁴ in the average composition formula (4) (excluding alkenyl groups).

Specific examples of the organohydrogenpolysiloxane represented by the above average composition formula (5) include 1,1,3,3-tetramethyldisiloxane, 1,3,5,7-tetramethylcyclotetrasiloxane, tris ( Hydrogendimethylsiloxy) methylsilane, tris (hydrogendimethylsiloxy) phenylsilane, methylhydrogencyclopolysiloxane, methylhydrogensiloxane-dimethylsiloxane cyclic copolymer, both ends trimethylsiloxy group-blocked methylhydrogenpolysiloxane, both ends Trimethylsiloxy group-blocked methylhydrogensiloxane / dimethylsiloxane copolymer, both ends methylhydrogensiloxy group-blocked dimethylpolysiloxane, both ends methylhydrogensiloxy group-blocked methylhydro Polysiloxane / dimethylsiloxane copolymer, trimethylsiloxy group-blocked methylhydrogensiloxane / diphenylsiloxane copolymer, trimethylsiloxy group-blocked methylhydrogensiloxane / diphenylsiloxane / dimethylsiloxane copolymer, trimethylsiloxy group at both ends Blocked methylhydrogensiloxane / methylphenylsiloxane / dimethylsiloxane copolymer, both-end methylhydrogensiloxy group-blocked methylhydrogensiloxane / diphenylsiloxane / dimethylsiloxane copolymer, both-end methylhydrogensiloxy group-blocked methylhydrogensiloxane methylphenylsiloxane-dimethylsiloxane _{copolymer, (CH} 3) 2 _{HSiO 1/2} units and _{(CH 3)} 2 S O _2/2 consisting of units and _{SiO 4/2} units, and _copolymers, copolymers consisting of _(CH 3) 2 _{HSiO 1/2} units and _{SiO 4/2 units, (CH} 3) 2 _{HSiO 1/2 Examples} thereof include a copolymer composed of a unit, a SiO _4/2 unit, and a (C ₆ H ₅ ) ₃ SiO _1/2 unit.

Although the addition amount of (c) component is arbitrary quantity, Preferably it is 0-100 mass parts with respect to 100 mass parts of (a) component, More preferably, it can be set as the range of 0-50 mass parts. When the added amount is more than 100 parts by mass with respect to 100 parts by mass of component (a), foaming derived from component (c) occurs, and the strength and heat resistance of the cured reaction product are adversely affected. .

-UV curable reactive silicone composition:
As an ultraviolet curing reactive silicone composition, specifically, for example, in addition to the surface treatment agent,
(D) UV-reactive organopolysiloxane, and (e) UV-curable reactive silicone composition containing a photopolymerization initiator.

-(D) component The ultraviolet-reactive organopolysiloxane of (d) component normally acts as a base polymer in an ultraviolet curing reactive silicone composition. The component (d) is not particularly limited, and is preferably an organopolysiloxane having at least 2, more preferably 2 to 20, particularly preferably 2 to 10 ultraviolet-reactive groups in one molecule. A plurality of the ultraviolet curing reactive groups present in the organopolysiloxane may be the same or different.

From the viewpoint of easy availability of raw materials, the organopolysiloxane of component (d) is basically composed of repeating diorganosiloxane units (R ⁴ ₂ SiO _2/2 units) in the molecular chain (main chain). A straight chain structure in which both ends of the molecular chain are blocked with a triorganosiloxy group (R ⁴ ₃ SiO _1/2 ), without branching, or the molecular chain is composed of repeating diorganosiloxane units. Although it has a cyclic structure that it does not have, it may partially contain a branched structure such as a trifunctional siloxane unit or SiO ₂ unit. Here, R ⁴ is as described regarding the formula (4). When the organopolysiloxane of component (d) has a linear structure, it has an ultraviolet-reactive group only at one of the molecular chain terminal and the part that is not the molecular chain terminal. However, it is preferable to have UV reactive groups at least at both ends of the molecular chain.

  Examples of the ultraviolet reactive group include alkenyl groups such as vinyl group, allyl group and propenyl group; alkenyloxy groups such as vinyloxy group, allyloxy group, propenyloxy group and isopropenyloxy group; acryloyl group and methacryloyl group. Aliphatic unsaturated groups other than alkenyl groups; epoxy groups; hydrosilyl groups and the like, preferably acryloyl groups, methacryloyl groups, mercapto groups, epoxy groups, and hydrosilyl groups, more preferably acryloyl groups and methacryloyl groups. Can be mentioned.

  The viscosity of the organopolysiloxane is not particularly limited, but is 100 mPa.s at 25 ° C. s to 1,000,000 mPa.s s, preferably 200 to 500,000 mPa.s. s, more preferably 200 to 100,000 mPa.s. Particularly preferred is s.

  As a preferred form of the component (d), for example, the following general formula (6a);

[Wherein R ⁶ is the same or different, unsubstituted or substituted monovalent hydrocarbon group having no UV-reactive group, and R ⁷ is the same or different group having an UV-reactive group; R ⁸ is the same or different group having an ultraviolet reactive group, m is an integer of 5 to 1,000, n is an integer of 0 to 100, f is an integer of 0 to 3, g is an integer of 0 to 3, provided that f + g + n ≧ 2]
Or the following general formula (6b);

[Wherein R ⁶ , R ⁷ , R ⁸ , m, n, f, g are as defined in the general formula (6a), h is an integer of 2-4, and i and j are each 1 Is an integer of ~ 3, where fi + gj + n ≧ 2]
And an organopolysiloxane having at least two ultraviolet-reactive groups represented by the formula:

In the above general formulas (6a) and (6b), R ⁶ is preferably the same or different, unsubstituted or substituted monovalent, monovalent carbon atoms having no UV-reactive group, preferably 1 to 20, more preferably 1-10 is still more preferably a monovalent hydrocarbon group of 1-8. Examples of the monovalent hydrocarbon group represented by R ⁶ include alkyl groups such as methyl group, ethyl group, propyl group, butyl group, pentyl group and hexyl group; aryl groups such as phenyl group, tolyl group, xylyl group and naphthyl group. A cycloalkyl group such as a cyclopentyl group, a cyclohexyl group or a cyclopentyl group; an aralkyl group such as a benzyl group or a phenylethyl group; a part or all of the hydrogen atoms bonded to these hydrocarbon groups are halogen atoms or cyano groups A group substituted with a carboxyl group, such as a chloromethyl group, a chloropropyl group, a bromoethyl group, a trifluoropropyl group, a cyanoethyl group, a 3-cyanopropyl group, preferably a methyl group and a phenyl group, More preferably, a methyl group is mentioned. The monovalent hydrocarbon group represented by R ³ may have one or more sulfonyl groups, ether bonds (—O—), carbonyl groups, and the like in its skeleton.

In the general formulas (6a) and (6b), examples of the ultraviolet-reactive group contained in R ⁷ and R ⁸ include alkenyl groups such as vinyl group, allyl group, propenyl group; vinyloxy group, allyloxy group, propenyloxy Group, alkenyloxy group such as isopropenyloxy group; aliphatic unsaturated group other than alkenyl group such as acryloyl group and methacryloyl group; mercapto group; epoxy group; hydrosilyl group and the like, preferably acryloyl group, methacryloyl group, An epoxy group and a hydrosilyl group are mentioned, More preferably, an acryloyl group and a methacryloyl group are mentioned. Therefore, the group having an ultraviolet reactive group represented by R ⁷ and R ⁸ is, for example, a monovalent group having the ultraviolet reactive group exemplified above. Specific examples thereof include a vinyl group, an allyl group, 3 -Glycidoxypropyl group, 2- (3,4-epoxycyclohexyl) ethyl group, 3-methacryloxypropyl group, 3-acryloxypropyl group, 3-mercaptopropyl group, 2- {bis (2-methacryloxyethoxy) ) Methylsilyl} ethyl group, 2- {bis (2-acryloxyethoxy) methylsilyl} ethyl group, 2-{(2-acryloxyethoxy) dimethylsilyl} ethyl group, 2- {bis (1,3-dimethacryloxy-2) -Propoxy) methylsilyl} ethyl group, 2-{(1,3-dimethacryloxy-2-propoxy) dimethylsilyl} ethyl group, 2- {bis (1 Acryloxy-3-methacryloxy-2-propoxy) methylsilyl} ethyl group, 2- {bis (1-acryloxy-3-methacryloxy-2-propoxy) dimethylsilyl} ethyl group, and the like, preferably 3-methacryloxypropyl Group, 3-acryloxypropyl group, 2- {bis (2-methacryloxyethoxy) methylsilyl} ethyl group, 2- {bis (2-acryloxyethoxy) methylsilyl} ethyl group, 2-{(2-acryloxyethoxy) ) Dimethylsilyl} ethyl group, 2-{(1,3-dimethacryloxy-2-propoxy) dimethylsilyl} ethyl group, 2- {bis (1-acryloxy-3-methacryloxy-2-propoxy) methylsilyl} ethyl group, and 2- {Bis (1-acryloxy-3-methacryloxy-2-propoxy) A dimethylsilyl} ethyl group. R ⁷ and R ⁸ may be the same or different, and R ⁷ and R ⁸ may be the same or different.

  In the general formulas (6a) and (6b), m is usually an integer of 5 to 1,000, preferably 10 to 800, more preferably 50 to 500, and n is usually 0 to 100, preferably Is an integer of 0-50, more preferably 0-20, f is an integer of 0-3, preferably 0-2, more preferably 1-2, g is 0-3, preferably 0-2. An integer of 1, more preferably 1 or 2. In said formula (6b), h is an integer of 2-4 normally, Preferably it is 2 or 3. i and j are each an integer of 1 to 3, preferably 1 or 2. Furthermore, since the organopolysiloxane represented by the general formulas (6a) and (6b) has at least two UV-reactive groups as described above, f + g + n ≧ 2 in the formula (6a), and in the formula (6b) fi + gj + n ≧ 2.

    Specific examples of the organopolysiloxane represented by the above formulas (6a) and (6b) include those shown below.

[In the above formula, R ⁹ is 90% methyl group and 10% phenyl group]

.. (e) Component The photopolymerization initiator of the component (e) has an action of promoting photopolymerization of the ultraviolet reactive group in the component (d). The component (e) is not particularly limited, and specific examples thereof include acetophenone, propiophenone, benzophenone, xanthol, fluorin, benzaldehyde, anthraquinone, triphenylamine, 4-methylacetophenone, 3-pentylacetophenone, 4- Methoxyacetophenone, 3-bromoacetophenone, 4-allylacetophenone, p-diacetylbenzene, 3-methoxybenzophenone, 4-methylbenzophenone, 4-chlorobenzophenone, 4,4'-dimethoxybenzophenone, 4-chloro-4'-benzylbenzophenone 3-chloroxanthone, 3,9-dichloroxanthone, 3-chloro-8-nonylxanthone, benzoin, benzoin methyl ether, benzoin butyl ether, bis (4-dimethylamino) Phenyl) ketone, benzylmethoxyacetal, 2-chlorothioxanthone, diethylacetophenone, 1-hydroxychlorophenyl ketone, 1-hydroxycyclohexyl phenyl ketone, 2-methyl- (4- (methylthio) phenyl) -2-morpholino-1-propane, 2,2-dimethoxy-2-phenylacetophenone, diethoxyacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one and the like are preferable. From the viewpoint of high purity, benzophenone, 4-methoxyacetophenone, 4-methylbenzophenone, diethoxyacetophenone, 1-hydroxycyclohexyl phenyl ketone and 2-hydroxy-2-methyl-1-phenylpropan-1-one are preferable, and diethoxyacetate is more preferable. Tophenone, 1-hydroxycyclohexyl phenyl ketone and 2-hydroxy-2-methyl-1-phenylpropan-1-one. These photopolymerization initiators may be used alone or in combination of two or more.

  Although the addition amount of (e) component is not specifically limited, Preferably it is 0.01-10 mass parts with respect to 100 mass parts of (d) component, More preferably, it is 0.1-3 mass parts, More preferably Is 0.5-3 parts by mass. When this addition amount is within this range, it is easy to control the curing of the silicone composition.

Addition-curing reactive silicone composition:
As the addition curing reactive silicone composition, specifically, for example, in addition to the surface treatment agent,
(F) an organopolysiloxane containing at least two alkenyl groups bonded to silicon atoms,
(G) Organohydrogenpolysiloxane containing at least two hydrogen atoms bonded to silicon atoms (i.e., SiH groups) The silicon atoms in component (g) per mole of alkenyl groups in the total curable silicone composition And an addition curing reactive silicone composition containing an amount of 0.1 to 5 moles of hydrogen atoms bonded to and (h) an effective amount of a platinum group metal catalyst.

.. (f) Component The organopolysiloxane of the component (f) is a base polymer of the addition-curing reactive silicone composition and contains at least two alkenyl groups bonded to silicon atoms. As the component (f), a known organopolysiloxane can be used. The weight average molecular weight of the organopolysiloxane of component (f) measured by gel permeation chromatography (hereinafter referred to as “GPC”) is preferably about 3,000 to 300,000 in terms of polystyrene. Furthermore, the viscosity of the organopolysiloxane of component (f) at 25 ° C. is 100 to 1,000,000 mPa.s. s, preferably 1,000 to 100,000 mPa.s. Particularly preferred is about s. 100 mPa. s or less, the spinnability is low and it is difficult to reduce the diameter of the fiber, and 1,000,000 mPa.s. Handling is difficult at s and above. From the viewpoint of easy availability of raw materials, the organopolysiloxane of component (f) is basically composed of repeating diorganosiloxane units (R ¹⁰ ₂ SiO _2/2 units) in terms of molecular chain (main chain). A linear structure having no branching, in which both ends of the molecular chain are blocked with a triorganosiloxy group (R ¹⁰ ₃ SiO _1/2 ), or a molecular chain consisting of repeating diorganosiloxane units. Although it has a cyclic structure that does not have, it may partially have a branched structure containing R ¹⁰ SiO _3/2 units or SiO _4/2 units. Here, R ¹⁰ is as described in relation to equation (7) described below.

As the component (f), for example, the following average composition formula (7):
R ¹⁰ _l SiO _{(4-1) / 2} (7)
(In the formula, R ¹⁰ is the same or different unsubstituted or substituted monovalent hydrocarbon group having 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, and l is preferably 1.5 as described above. -2.8, more preferably 1.8 to 2.5, and even more preferably a positive number in the range of 1.95 to 2.05), and at least two alkenyl groups in one molecule. An organopolysiloxane having the following formula is used. Examples of R ¹⁰ include the groups exemplified for R ⁴ in the average composition formula (4).

In this case, at least two of R ¹⁰ are alkenyl groups (particularly alkenyl groups having preferably 2 to 8, more preferably 2 to 6 carbon atoms). The content of the alkenyl group is in the total organic group bonded to the silicon atom (that is, in the unsubstituted or substituted all monovalent hydrocarbon group represented by R ¹⁰ in the average composition formula (7)), preferably 50. It is -99 mol%, Most preferably, it is 75-95 mol%. When the organopolysiloxane of component (f) has a linear structure, the alkenyl group is bonded to a silicon atom only in one of the molecular chain terminal and the non-molecular chain terminal, but both of them are silicon. Although it may be bonded to an atom, it is desirable that at least one alkenyl group is bonded to a silicon atom at the end of the molecular chain in view of the curing speed of the composition, the physical properties of the cured product, and the like.

.. (g) Component (g) The organohydrogenpolysiloxane of component (g) has at least two hydrogen atoms (SiH groups) bonded to silicon atoms (usually 2 to 200), preferably 3 or more (usually 3 to 3). 100). The component (g) reacts with the component (f) and acts as a crosslinking agent. The molecular structure of the component (g) is not particularly limited. For example, any conventionally produced organohydrogenpolysiloxane such as linear, cyclic, branched, and three-dimensional network (resinous) can be used as the component (b). Can be used as (G) When the component has a linear structure, the SiH group is bonded to the silicon atom only in one of the molecular chain terminal and the non-molecular chain terminal, but is bonded to the silicon atom in both of them. Also good. The number of silicon atoms in one molecule (or the degree of polymerization) is usually 2 to 300, preferably about 4 to 150, and the organohydrogenpolysiloxane that is liquid at room temperature (25 ° C.) (G) It can use preferably as a component.

As the component (g), for example, the following average composition formula (8):
R ¹¹ _{pH q} SiO _{(4-pq) / 2} (8)
(In the formula, R ¹¹ is a monovalent hydrocarbon group having 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, having the same or different unsubstituted or substituted, aliphatic unsaturated bonds, and p And q are preferably 0.7 ≦ p ≦ 2.1, 0.001 ≦ q ≦ 1.0, and 0.8 ≦ p + q ≦ 3.0, more preferably 1.0 ≦ p ≦ 2.0, (It is a positive number satisfying 0.01 ≦ q ≦ 1.0 and 1.5 ≦ p + q ≦ 2.5.)
The organohydrogenpolysiloxane shown by these is used. Examples of R ¹¹ include the groups exemplified for R ⁴ in the average composition formula (4) (excluding alkenyl groups).

Specific examples of the organohydrogenpolysiloxane represented by the above average composition formula (8) include 1,1,3,3-tetramethyldisiloxane, 1,3,5,7-tetramethylcyclotetrasiloxane, tris ( Hydrogendimethylsiloxy) methylsilane, tris (hydrogendimethylsiloxy) phenylsilane, methylhydrogencyclopolysiloxane, methylhydrogensiloxane-dimethylsiloxane cyclic copolymer, both ends trimethylsiloxy group-blocked methylhydrogenpolysiloxane, both ends Trimethylsiloxy group-blocked methylhydrogensiloxane / dimethylsiloxane copolymer, both ends methylhydrogensiloxy group-blocked dimethylpolysiloxane, both ends methylhydrogensiloxy group-blocked methylhydro Polysiloxane / dimethylsiloxane copolymer, trimethylsiloxy group-blocked methylhydrogensiloxane / diphenylsiloxane copolymer, trimethylsiloxy group-blocked methylhydrogensiloxane / diphenylsiloxane / dimethylsiloxane copolymer, trimethylsiloxy group at both ends Blocked methylhydrogensiloxane / methylphenylsiloxane / dimethylsiloxane copolymer, both-end methylhydrogensiloxy group-blocked methylhydrogensiloxane / diphenylsiloxane / dimethylsiloxane copolymer, both-end methylhydrogensiloxy group-blocked methylhydrogensiloxane methylphenylsiloxane-dimethylsiloxane _{copolymer, (CH} 3) 2 _{HSiO 1/2} units and _{(CH 3)} 2 S O _2/2 consisting of units and _{SiO 4/2} units, and _copolymers, copolymers consisting of _(CH 3) 2 _{HSiO 1/2} units and _{SiO 4/2 units, (CH} 3) 2 _{HSiO 1/2 Examples} thereof include a copolymer composed of a unit, a SiO _4/2 unit, and a (C ₆ H ₅ ) ₃ SiO _1/2 unit.

The amount of component (g) added is, in particular, per mole of alkenyl groups in the total curable silicone composition, in particular per mole of alkenyl groups bonded to silicon atoms in the total curable silicone composition. The amount of SiH group in the component (g) is 0.1 to 5.0 mol, preferably 0.5 to 3.0 mol, more preferably 0.8 mol per mol of alkenyl group bonded to the silicon atom. The amount is 8 to 2.0 mol. At this time, the ratio of the alkenyl group bonded to the silicon atom in the component (f) to the alkenyl group present in the total curable silicone composition is preferably 80 to 100 mol%, and more preferably 90 to 100 mol%. When only the component (f) is present as the component having an alkenyl group in the total curable silicone composition, the amount of SiH in the component (g) is about 0.1 per mole of the alkenyl group in the component (f). The amount is 1 to 5.0 mol, preferably 0.5 to 3.0 mol, more preferably 0.8 to 2.0 mol. When the added amount is such that the amount of SiH is less than 0.1 mol, it takes a long time to cure, which is economically disadvantageous.
Further, if the amount of SiH added is more than 5.0 mol, foaming due to dehydrogenation reaction occurs in the cured reaction product, and the strength and heat resistance of the cured reaction product are adversely affected. Receive.

.. (h) Component The platinum group metal catalyst of the (h) component is used as a catalyst for promoting an addition curing reaction (hydrosilylation reaction) between the (f) component and the (g) component. As the component (h), a known platinum group metal catalyst can be used, but it is preferable to use platinum or a platinum compound. Specific examples of the component (h) include platinum black, platinum chloride, chloroplatinic acid, alcohol-modified chloroplatinic acid, and complexes of chloroplatinic acid with olefins, aldehydes, vinyl siloxanes, or acetylene alcohols. .

  The amount of component (h) added is an effective amount as a catalyst, and may be increased or decreased in a timely manner according to the desired curing reaction rate. Is in the range of 0.1 to 1,000 ppm, more preferably 0.2 to 100 ppm.

・ Condensation curing type silicone composition:
As the condensation curing reaction type silicone composition, specifically, for example, in addition to the surface treatment agent,
(I) an organopolysiloxane containing at least two silanol groups (that is, silicon atom-bonded hydroxyl groups) or silicon atom-bonded hydrolyzable groups, preferably at both ends of the molecular chain;
(J) As an optional component, a hydrolyzable silane and / or a partially hydrolyzed condensate thereof, and (k) As an optional component, a condensation curing reaction type silicone composition containing a condensation reaction catalyst can be mentioned.

.. (i) Component (i) The component is an organopolysiloxane containing at least two silanol groups or silicon atom-bonded hydrolyzable groups, and is a base polymer of a condensation curing reaction type silicone composition. From the viewpoint of easy availability of raw materials, the organopolysiloxane of component (i) is basically composed of repeating diorganosiloxane units (R ¹¹ ₂ SiO _2/2 units) in the molecular chain (main chain). A straight chain structure in which both ends of the molecular chain are blocked with a triorganosiloxy group (R ¹¹ ₃ SiO _1/2 ), without a branch, or the molecular chain is composed of repeating diorganosiloxane units. Although it has a cyclic structure that it does not have, it may partially contain a branched structure. Here, R ¹¹ represents an unsubstituted or substituted monovalent hydrocarbon group having 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms.

  In the organopolysiloxane of component (i), examples of hydrolyzable groups other than silanol groups include acyl groups such as acetoxy group, octanoyloxy group, benzoyloxy group; dimethyl ketoxime group, methyl ethyl ketoxime group, diethyl Ketoxime groups such as ketoxime groups (ie, iminoxy groups); alkoxy groups such as methoxy groups, ethoxy groups, and propoxy groups; alkoxyalkoxy groups such as methoxyethoxy groups, ethoxyethoxy groups, and methoxypropoxy groups; vinyloxy groups, isopropenyloxy Groups, alkenyloxy groups such as 1-ethyl-2-methylvinyloxy group; amino groups such as dimethylamino group, diethylamino group, butylamino group and cyclohexylamino group; aminoxy groups such as dimethylaminoxy group and diethylaminoxy group N- methylacetamide, N- ethylacetamide group, and amide groups such as N- methylbenzamide group.

  These hydrolyzable groups include, for example, trialkoxysiloxy groups, dialkoxyorganosiloxy groups, triacyloxysiloxy groups, diacyloxyorganosiloxy groups, triiminoxysiloxy groups (ie, triketoxime siloxy groups), diiminoxy groups Siloxy groups containing two or three hydrolyzable groups, such as organosiloxy groups, trialkenoxysiloxy groups, dialkenoxy tsuganosiloxy groups, trialkoxysiloxyethyl groups, dialkoxyorganosiloxyethyl groups, or two Alternatively, it is desirable to be located at both ends of the molecular chain of the linear diorganopolysiloxane in the form of a siloxyalkyl group containing three hydrolyzable groups.

Examples of the other monovalent hydrocarbon group bonded to the silicon atom include the same unsubstituted or substituted monovalent hydrocarbon groups as those exemplified for R ⁴ in the average composition formula (4).

  As the component (i), for example,

[In the above formula, X is a hydrolyzable group other than the silanol group, a is 1, 2 or 3, and n and m are each an integer of 1 to 1,000]
Is mentioned.

  Specific examples of the component (i) include molecular chain both ends silanol-blocked dimethylpolysiloxane, molecular chain both ends silanol-blocked dimethylsiloxane / methylphenylsiloxane copolymer, molecular chain both ends silanol-blocked dimethylsiloxane / diphenylpolysiloxane. Siloxane copolymer, trimethoxysiloxy group-capped dimethylpolysiloxane with molecular chain at both ends, trimethoxysiloxy group-capped dimethylsiloxane / methylphenylsiloxane copolymer with molecular chain at both ends, trimethoxysiloxy group-capped dimethylsiloxane / diphenyl Examples thereof include polysiloxane copolymers and 2-trimethoxysiloxyethyl group-blocked dimethylpolysiloxane having both molecular chain terminals. These can be used singly or in combination of two or more.

.. (j) Component The hydrolyzable silane and / or partial hydrolysis condensate thereof as the component (j) are optional components and act as a curing agent. When component (i) which is a base polymer is an organopolysiloxane containing at least two silicon atom-bonded hydrolyzable groups other than silanol groups in one molecule, component (j) is a condensation-curing reaction type silicone composition. Adding to the product can be omitted. As the component (j), a silane containing at least three silicon atom-bonded hydrolyzable groups in one molecule and / or a partial hydrolysis condensate thereof (that is, at least one, preferably two or more hydrolysis products) An organopolysiloxane in which a functional group remains is preferably used.

Examples of the silane include a formula (9):
R ¹² _r SiX _4-r (9)
(In the formula, R ¹² is an unsubstituted or substituted monovalent hydrocarbon group having 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, X is a hydrolyzable group, and r is 0 or 1.) What is represented by these is used preferably. R ¹² is particularly preferably an alkyl group such as a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group or a hexyl group; an aryl group such as a phenyl group or a tolyl group; an alkenyl group such as a vinyl group or an allyl group. can give.

  Specific examples of the component (j) include methyltriethoxysilane, vinyltriethoxysilane, vinyltriacetoxysilane, ethyl orthosilicate and the like, and partial hydrolysis condensates thereof. These can be used singly or in combination of two or more.

  (J) When using the component hydrolyzable silane and / or the partial hydrolysis condensate thereof, the amount added is preferably 0.01 to 20 parts by weight, particularly preferably 0 with respect to 100 parts by weight of component (i). .1 to 10 parts by mass. When the component (j) is used, the storage stability and curing reaction rate of the composition of the present invention are particularly good when the amount added is within the above range.

.. (j) Component (j) The condensation reaction catalyst of component (component) is an optional component, and the hydrolyzable silane and / or partial hydrolysis condensate thereof of component (j) is, for example, an aminoxy group, amino group, ketoxime If it has a group, it may not be used. Examples of the condensation reaction catalyst for component (k) include organic titanates such as tetrabutyl titanate and tetraisobropyrutitanate; diisopropoxybis (acetylacetonato) titanium, diisopropoxybis (ethylacetoacetate) titanium and the like. Organic titanium chelate compounds; organoaluminum compounds such as aluminum tris (acetylacetonate) and aluminum tris (ethylacetoacetate); organozirconium compounds such as zirconium tetra (acetylacetonate) and zirconium tetrabutyrate; dibutyltin dioctoate, Organotin compounds such as dibutyltin dilaurate and dibutyltin di (2-ethylhexanoate); tin naphthenate, tin oleate, tin butyrate, cobalt naphthenate, stearic acid Metal salts of organic carboxylic acids such as: amine compounds such as hexylamine and dodecylamine phosphate, and salts thereof; quaternary ammonium salts such as benzyltriethylammonium acetate; lower fatty acid salts of alkali metals such as potassium acetate and lithium nitrate; Examples include dialkylhydroxylamine such as dimethylhydroxylamine and diethylhydroxylamine: guanidyl group-containing organosilicon compounds. These can be used singly or in combination of two or more.

  When the condensation reaction catalyst of component (k) is used, the amount added is not particularly limited and may be an effective amount as a catalyst, but is preferably 0.01 to 20 parts by mass with respect to 100 parts by mass of component (i). Especially preferably, it is 0.1-10 mass parts. When the component (k) is used, it is economically advantageous from the viewpoint of curing time and curing temperature when the amount added is within the above range.

-Curing of organic peroxide curing reactive silicone composition:
By heating the organic peroxide curing reaction type silicone composition, the radical reaction proceeds, the curing reaction proceeds, and the organic peroxide silicone composition is cured. The temperature condition for curing the organic peroxide silicone composition is not particularly limited because the curing reaction depends on the coating thickness, that is, the coating amount, but preferably 80 ° C. It is 150-250 degreeC more preferably -300 degreeC. Moreover, you may perform a secondary cure as needed, As temperature conditions in that case, Preferably it is 120 degreeC or more, More preferably, it is 150 to 250 degreeC. The curing time at this time is preferably 10 minutes to 48 hours, more preferably 30 minutes to 24 hours.

-Curing of UV curable reactive silicone composition:
By irradiating the ultraviolet curable reactive silicone composition with ultraviolet rays, the photopolymerization initiator reacts, the curing reaction proceeds, and the ultraviolet curable reactive silicone composition is cured. The ultraviolet irradiation conditions are not particularly limited because the curing reaction depends on the coating thickness, that is, the coating amount, but an ultraviolet light emitting diode having an emission wavelength of 365 nm is used, and an illuminance of 5 to 500 mW / cm ² , Preferably 10-200 mW / cm ² , light quantity 0.5-100 J / cm ² , preferably. It can be hardened by irradiating with ultraviolet rays under conditions of 10-50 J / cm ² . Moreover, you may perform a secondary cure as needed, As temperature conditions in that case, Preferably it is 120 degreeC or more, More preferably, it is 150 to 250 degreeC. The curing time at this time is preferably 10 minutes to 48 hours, more preferably 30 minutes to 24 hours.

Curing of addition curing reactive silicone composition:
By heating the addition-curing reactive silicone composition, the hydrosilylation reaction proceeds and the addition-curing reactive silicone composition is cured. The heating temperature at this time is not particularly limited because the curing reaction depends on the coating, that is, depends on the coating amount, but is preferably 80 to 300 ° C, more preferably 100 to 200 ° C. Moreover, you may perform a secondary cure as needed, As temperature conditions in that case, Preferably it is 120 degreeC or more, More preferably, it is 150 to 250 degreeC. The curing time at this time is preferably 10 minutes to 48 hours, more preferably 30 minutes to 24 hours.

-Curing of condensation curing reaction type silicone composition:
The condensation reaction proceeds by heating the condensation curing reaction type silicone composition, and the condensation curing reaction silicone composition is cured. The temperature condition for curing the condensation-curing reaction type silicone composition is not particularly limited as the heating temperature in this case, since the curing reaction depends on the coating thickness, that is, depends on the coating amount, preferably 80 ° C. It is more preferably 100 ° C to 200 ° C. Moreover, you may perform a secondary cure as needed, As temperature conditions in that case, Preferably it is 120 degreeC or more, More preferably, it is 150 to 250 degreeC. The curing time at this time is preferably 10 minutes to 48 hours, more preferably 30 minutes to 24 hours.

・ Other ingredients:
Regardless of the type of curing mechanism, other components can be blended in the composition of the present invention as necessary, and examples thereof include a dispersibility improver.

  The dispersibility improver has the function of increasing the dispersibility of the surface-treated silica and improving the fluidity of the composition by being added to the composition. Specifically, organos such as hexamethyldisilazane, 1,3-divinyl-1,1,3,3-tetramethyldisilazane, 1,1,3,5,5,5-heptamethyl-3-vinyltrisilazane, etc. Examples thereof include organosilicon compounds such as silazane, organoaminosilanes such as dimethylaminotrimethylsilazane and dimethylaminodimethylvinylsilane, and organosilanes such as organochlorosilane and organoalkoxysilane.

  When the composition is an addition-curable type, ethynylmethylidenecarbinol, 1-ethynyl-1-hexyl-3-butyne, or the like can be added as an addition reaction control agent.

  The cured product obtained by curing the composition of the present invention has good thermal conductivity, and the thermal conductivity is preferably a measured value at 25 ° C. by a hot disk method of 0.3 W / mK or more. It is desirable that it is 0.4 or more. When the thermal conductivity is less than 0.3 W / mK, application to a heating element having a large calorific value is not suitable. Further, the cured product is excellent in transparency, but when measured at 20 ° C. in a layer state of 1 mm in thickness, the light transmittance at a wavelength of 800 nm is preferably 60% or more, and 70% or more. Is more preferable. Further, the cured product has flame retardancy that meets UL94V-1 standards when measured in a layer state of 1 mm thickness.

-Preparation Example 1:
-Synthesis of surface-treated silica (C-1)-
To a mixed solution of 50 g of ammonia water (28% by mass), 42 g of water and 625 g of methanol, 1165 g of tetramethoxysilane was added and stirred for 6 hours. Subsequently, 400 g of ammonia water (5.4% by mass) was added and stirred for 4 hours to obtain sol-gel silica. Further, 1200 g of water was added, 12 g of trimethoxymethylsilane was added and stirred for 12 hours, 450 g of methyl isobutyl ketone was added, and water was distilled off. Thereafter, 150 g of hexamethyldisilazane was added and stirred at 100 ° C. for 3 hours, and then the solvent was distilled off and dried to obtain surface-treated silica (C-1).

-Measurement of surface treatment degree-
Surface-treated silica (C-1) (0.3 g), tetraethoxysilane (3 g) and potassium hydroxide (0.085 g) were collected and heat-treated at 120 ° C. for 3 hours. As a standard sample at this time, tris (trimethylsiloxy) methylsilane was used. The M unit was determined from a calibration curve obtained by adding correction values of triethoxymethylsilane and dimers of triethoxymethylsilane and tetraethoxysilane. The T unit was obtained by multiplying the area ratio of gas chromatography based on the M unit amount by the mol ratio coefficient.

The results measured as described above are shown below.
M unit: 0.0093 (mol / 100g)
T unit: 0.015 (mol / 100g)

Since sol-gel silica is composed of Q units, the amount of Q units can be determined by subtracting the amount of M units and T units obtained from the measurement. In this case, the M unit is SiMe ₃ O _1/2 and the formula weight is 81.19, and the T unit is SiMeO _3/2 and the formula weight is 67.12. Therefore, in 100 g of the surface-treated silica, the M unit is 0.76 g and the T unit. Contains 1.00g. That is, 98.24 g obtained by subtracting the M unit amount and the T unit amount from 100 g is the Q unit amount contained in 100 g of the treated silica. Since this is 1.64 mol in terms of the number of moles, p / q = 0.015 on a molar basis.

-Average particle size-
It was 130 nm when measured by the microtrack method.

-Preparation Example 2:
-Synthesis of surface-treated silica (C-2)-
Surface treated silica (C-2) was synthesized in the same procedure as in Preparation Example 1, and p / q = 0.03 was calculated in the same manner. The average particle size was measured as 150 nm.

-Preparation Example 3:
-Synthesis of surface-treated silica (C-3)-
Surface-treated silica (C-3) was synthesized in the same procedure as in Preparation Example 1, and p / q = 0.008 was calculated in the same manner. The average particle size was measured as 160 nm.

-Preparation Example 4:
-Synthesis of surface-treated silica (C-4)-
Surface-treated silica (C-4) was synthesized in the same procedure as in Preparation Example 1, and p / q = 0.04 was calculated in the same manner. The average particle size was measured as 150 nm.

-Examples 1-5, Comparative Examples 1-4
Materials used:
<(A) component>
formula:

(In the formula, X is a vinyl group, and n is a number having the following viscosity (25 ° C.).)
(A-1) Viscosity: 100 mm ² / s
(A-2) Viscosity: 600 mm ² / s

<(B) component>
formula:

(Where, o is the average value 28, p is the average value 10)
Organohydrogenpolysiloxane represented by

<(C) component>
silica
(C-1) p / q = 0.015 (average particle size 130 nm)
(C-2) p / q = 0.03 (average particle size 150 nm)
(C-3) p / q = 0.008 (average particle size 160 nm)
(C-4) p / q = 0.004 (average particle size 150 nm)
(C-5) Untreated silica (Aerosil 130)

<(D) component>
Addition curing catalyst
5 mass% chloroplatinic acid 2-ethylhexanol solution (component (E))
Ethynylmethylidenecarbinol as an addition reaction control agent.
Component (F) Hexamethyldisilazane

..Preparation of composition:
In each example and each comparative example, the components (A) and (C) were kneaded for 60 minutes in a predetermined amount shown in Table 1 using a planetary mixer. Thereafter, the components (D) and (E) are added to the obtained kneaded material in predetermined amounts as shown in Table 1, and an effective amount of an internal release agent that promotes release from the separator is added, and then kneaded for 30 minutes. did. Further, a predetermined amount of component (B) shown in Table 1 was added and kneaded for 30 minutes to obtain a composition.
-Molding and curing The compositions of each Example and Comparative Example were poured into a 100 mm x 100 mm x 1 mm (depth) mold and processed at 110 ° C for 10 minutes using a press molding machine. Unless otherwise specified, the following evaluation was performed using the 1 mm thick sheet thus obtained.
-Characteristic evaluation The following characteristics were measured and evaluated. The results are shown in Table 1.

··Thermal conductivity:
Thermal conductivity was measured with a thermal conductivity meter (TPA-501, trade name of Kyoto Electronics Industry Co., Ltd.) using two 6mm thick sheets prepared using a 60mm x 60mm x 60mm (depth) mold. It was measured.

··Optical transparency:
A 1 mm thick sheet was measured using a spectrophotometer (manufactured by Hitachi, Ltd.).

··Flame retardance:
The test was conducted in accordance with UL94 flame retardancy test method.

・ Evaluation:
When the p / q value of the surface-treated silica is smaller than 0.01 as in Comparative Example 1, the dispersibility is lowered despite the fact that the same mass parts of silica as in Example 1 are filled, so that light transmittance is reduced. Declined. When the degree of surface treatment was further reduced as in Comparative Example 2, the dispersibility was worsened and the light transmittance was lowered. When untreated silica was used as in Comparative Example 3, the filling property was remarkably lowered, and even 20 parts by mass could not be filled.

  The thermally conductive silicone composition of the present invention can be used in places where transparency is required in addition to thermal conductivity or heat dissipation and flame retardancy. For example, it is useful as a transparent heat dissipation protective film for liquid crystal panel displays (LCD), as a transparent sealing material for transparent light emitting diode (LED) elements, and as a transparent reflector material.

Claims (8)

(Α) Hydrophobized surface-treated silica composed of a base silica composed of SiO _1/2 units (Q units) and a surface treatment agent treated and bonded to the surface, and
(Β) A thermally conductive silicone composition containing a polyorganosiloxane component,
The surface treatment agent has the general formula (X):

(In the formula, R ¹ may have a trifunctional branch but does not have a tetrafunctional branch, is a monovalent organosiloxane group whose terminal bonded to a silicon atom is terminated with an oxygen atom, or Or a substituted or unsubstituted monovalent hydrocarbon group, R ² is an alkyl group, and x is an integer of 1 to ^3. )
An organosilicon compound represented by
The molar ratio (p / q) of the number (p) of silicon atoms constituting the surface treatment agent bonded to the surface of the base silica with respect to the number (q) of Q units is in the range of 0.01 to 0.3. A thermally conductive silicone composition characterized by that.
  The silicone composition according to claim 1, comprising 100 to 500 parts by mass of the surface-treated silica with respect to 100 parts by mass of the organopolysiloxane component in the composition.   The silicone composition according to claim 1 or 2, wherein the surface-treated silica has an average particle size of 20 nm to 200 nm.   The silicone composition according to any one of claims 1 to 3, which is an addition reaction curable type.   The silicone hardened | cured material obtained by hardening the composition of any one of Claims 1-4.   The cured silicone according to claim 5, which has a thermal conductivity of 0.3 W / mK or more.   The cured silicone product according to claim 5 or 6, wherein when measured at 20 ° C in a layer state having a thickness of 1 mm, the transmittance of light having a wavelength of 800 nm is 60% or more and the transparency is high. The cured silicone according to any one of claims 5 to 7, which has flame retardancy that satisfies UL94V-1 standards when measured in a layer state having a thickness of 1 mm.