JP6800522B2 - UV curable silicone resin composition - Google Patents

Description

The present invention relates to an ultraviolet curable silicone resin composition.

Among the silicone resin compositions, the ultraviolet curable silicone resin composition is cured in a short time by irradiation with ultraviolet rays to form a cured product having excellent heat resistance, weather resistance, electrical insulation, and flexibility. For example, it is used as a transformer high-voltage circuit, various electronic control devices for automobiles, a semiconductor pressure sensor, a hybrid IC for automobiles and home appliances, a sealing material for various electronic parts such as semiconductor parts, and a protective material.

Japanese Unexamined Patent Publication No. 2014-1341

However, the cured product of the silicone resin composition is easily deformed due to its flexibility, but when it is compressed for a long period of time, it is difficult to restore it, it is difficult to maintain its shape, and the usable part is limited. There was a tendency.

Therefore, it is an object of the present invention to provide an ultraviolet curable silicone resin composition which can exhibit good curability by irradiation with ultraviolet rays and gives a cured product having a small compression set.

The present inventors have discovered that an ultraviolet curable silicone resin composition containing an aerosol silica surface-treated with a specific surface treatment agent solves the above-mentioned problems, and has reached the present invention.

〔式（Ｉ）中、
Ｒは、独立して、Ｃ１〜Ｃ６アルキル基、Ｃ６〜Ｃ１２アリール基、Ｃ１〜Ｃ６アルコキシ基又は式（ａ）：

（ここで、Ｒ_ａは、独立して、水素原子又はメチルであり、
Ｑ_１は、独立して、Ｃ１〜Ｃ５アルキレン基（好ましくは、トリメチレン基）である）で示される基であるが、
少なくとも１個のＲは、式（ａ）で示される基であり、
ｎは、（Ａ１）の粘度を、１００〜１００，０００ｍＰａ・ｓとする値である〕
で示される直鎖状ポリオルガノシロキサンである、［１］のシリコーン樹脂組成物。
［３］少なくとも１個のＲが、Ｃ１〜Ｃ６アルコキシ基である、［２］のシリコーン樹脂組成物。
［４］（Ｂ）が、（メタ）アクリロイル基を有する有機ケイ素化合物及び（メタ）アクリロイル基を有さない有機ケイ素化合物で表面処理された煙霧質シリカである、［１］〜［３］のいずれか１つのシリコーン樹脂組成物。
［５］（Ｂ）のＢＥＴ比表面積が、５０〜４００ｍ^２／ｇである、［１］〜［４］のいずれか１つのシリコーン樹脂組成物。
［６］（Ｃ）の含有量が、（Ａ）及び（Ｂ）の合計１００重量部に対し、０．０１〜５重量部である、［１］〜［５］のいずれか１つのシリコーン樹脂組成物。
［７］更に、有機スズ化合物及び有機チタン化合物からなる群より選択される１種以上の（Ｄ）金属触媒を含む、［１］〜［６］のいずれか１つのシリコーン樹脂組成物。
［８］ポッティング剤、接着剤、パッキン剤又は液状ガスケット剤である、［１］〜［７］のいずれか１つに記載の樹脂組成物。 The gist of the present invention is as follows.
[1] (A) (Meta) Polyorganosiloxane containing an acryloyloxy group;
An ultraviolet curable silicone resin composition comprising (B) an aerosol silica surface-treated with an organosilicon compound having a (meth) acryloyl group; and (C) a photoreaction initiator.
[2] (A) is the formula (I) of (A1):

[In formula (I),
R is independently a C1-C6 alkyl group, a C6-C12 aryl group, a C1-C6 alkoxy group or formula (a):

(Here, _Ra is independently a hydrogen atom or methyl, and
Q ₁ is a group independently represented by a C1-C5 alkylene group (preferably a trimethylene group).
At least one R is a group represented by the formula (a).
n is a value that makes the viscosity of (A1) 100 to 100,000 mPa · s]
The silicone resin composition of [1], which is a linear polyorganosiloxane represented by.
[3] The silicone resin composition of [2], wherein at least one R is a C1 to C6 alkoxy group.
[4] (B) are fumigant silica surface-treated with an organosilicon compound having a (meth) acryloyl group and an organosilicon compound having no (meth) acryloyl group, according to [1] to [3]. Any one silicone resin composition.
[5] The silicone resin composition according to any one of [1] to [4], wherein the BET specific surface area of (B) is 50 to 400 m ² / g.
[6] The silicone resin according to any one of [1] to [5], wherein the content of (C) is 0.01 to 5 parts by weight with respect to 100 parts by weight in total of (A) and (B). Composition.
[7] The silicone resin composition according to any one of [1] to [6], further comprising one or more (D) metal catalysts selected from the group consisting of an organic tin compound and an organic titanium compound.
[8] The resin composition according to any one of [1] to [7], which is a potting agent, an adhesive, a packing agent or a liquid gasket agent.

According to the present invention, it is possible to provide an ultraviolet curable silicone resin composition which can exhibit good curability by irradiation with ultraviolet rays and gives a cured product having a small compression set.

[UV curable silicone resin composition]
The ultraviolet curable silicone resin composition (hereinafter, also simply referred to as “composition”) is a polyorganosiloxane containing (A) (meth) acryloyloxy group, and an organosilicon compound having (B) (meth) acryloyl group. Includes fuming silica surface-treated with (C) photoinitiator. The (meth) acryloyloxy group means at least one of an acryloyloxy group and a methacryloyloxy group. The (meth) acryloyl group means at least one of an acryloyl group and a methacryloyl group.

The resin composition preferably gives a cured product having a small compression set even in a heated state. Here, the heating temperature is preferably 40 ° C. or higher, more preferably 120 ° C. or higher, which causes softening and deterioration of ordinary organic resins, and even more preferably 120 ° C. to 200 ° C. It is particularly preferable that the resin composition gives a cured product having a small compression set at 120 ° C.

<(A) (Meta) polyorganosiloxane containing acryloyloxy group>
The composition comprises a (A) (meth) acryloyloxy group-containing polyorganosiloxane. From the viewpoint of increasing the curability and hardness of the surface, (A) is preferably a polyorganosiloxane containing an acryloyloxy group. Further, it is preferable that (A) further has an alkoxy group from the viewpoint that the composition has moisture curability, which enhances the surface curability of the cured product. (A) may be linear or branched chain, but linear is preferable.

〔式（Ｉ）中、
Ｒは、独立して、Ｃ１〜Ｃ６アルキル基、Ｃ６〜Ｃ１２アリール基、Ｃ１〜Ｃ６アルコキシ基又は式（ａ）：

（ここで、Ｒ_ａは、独立して、水素原子又はメチルであり、
Ｑ_１は、独立して、Ｃ１〜Ｃ５アルキレン基である）で示される基であるが、
少なくとも１個のＲは、式（ａ）で示される基であり、
ｎは、（Ａ１）の粘度を、１００〜１００，０００ｍＰａ・ｓとする値である〕
で示されるポリオルガノシロキサンが好ましい。 As the linear (A), the formula (A1) (I):

[In formula (I),
R is independently a C1-C6 alkyl group, a C6-C12 aryl group, a C1-C6 alkoxy group or formula (a):

(Here, _Ra is independently a hydrogen atom or methyl, and
Q ₁ is, independently is a group represented by a is) C1 to C5 alkylene group,
At least one R is a group represented by the formula (a).
n is a value that makes the viscosity of (A1) 100 to 100,000 mPa · s]
The polyorganosiloxane represented by is preferred.

In the formula (I), the number of Rs, which is the group represented by the formula (a), is preferably 1 to 10, and more preferably 2 to 5 from the viewpoint of ease of synthesis, reactivity and obtained properties. It is an individual.

R, which is a group represented by the formula (a), may be bonded to any silicon atom in the formula (I), but is preferably bonded to the terminal silicon atom. From the viewpoint of the flexibility of the obtained cured product, it is more preferably bonded to the silicon atoms at both ends, further preferably bonded only to the silicon atoms at both ends, and particularly preferably the silicon atoms at both ends. Only one R is bonded to each of the groups represented by the formula (a).

R _a is, from the viewpoint of surface curability and hardness increases, hydrogen atom is preferable.

Q ₁ is a C1 to C5 alkylene group, which may be linear or branched. Q ₁ is, from the viewpoint of the reactivity of the (meth) acrylic functional group, preferably has a number 3 or more chain length carbon atoms, durability of the cured product obtained from the viewpoint of transparency, more preferably a trimethylene group (-(CH ₂ ) _3- ).

In the formula (I), R other than the group represented by the formula (a) is a C1-C6 alkyl group (for example, a methyl group, an ethyl group, a propyl group, an n-butyl group, an isobutyl group, an s-butyl group, tert. -Butyl group or the like, preferably a methyl group), C6-C12 aryl group (for example, a phenyl group, a trill group or the like, preferably a phenyl group), a C1-C6 alkoxy group (for example, a phenyl group). It is a methoxy group, an ethoxy group, etc., preferably a methoxy group). A methyl group is preferable from the viewpoint of ease of synthesis and economy. Further, since the composition has room temperature curability, which increases the hardness of the cured product, at least one R is preferably a C1 to C6 alkoxy group.

n is a value that sets the viscosity of (A1) to 100 to 100,000 mPa · s, and the increased flexibility of the cured product causes compression set (preferably compression set in a heated state). From the viewpoint of becoming smaller, a value of 300 to 75,000 mPa · s is preferable, a value of 500 to 50,000 mPa · s is more preferable, and a value of 700 to 30,000 mPa · s is further preferable, and 1,500. A value of about 20,000 mPa · s is particularly preferable.

〔式中、
Ｒ^１は、水素原子又はメチル基であり、
Ｒ^２は、トリメチレン基であり、
Ｒ^３は、Ｃ１〜Ｃ４アルキル基（例えば、メチル基、エチル基、プロピル基等であり、メチル基が好ましい）又はＣ１〜Ｃ４アルコキシ基（例えば、メトキシ基、エトキシ基、プロポキシ基等であり、メトキシ基が好ましい）であり、
Ｒ^４は、Ｃ１〜Ｃ４アルキル基（例えば、メチル基、エチル基、プロピル基等であり、メチル基が好ましい）であり、
ｎは、（Ａ１’）の粘度を１００〜１００，０００ｍＰａ・ｓとする値である）
で示されるポリオルガノシロキサンが特に好ましい。 From the viewpoint of obtaining good curability, (A) is a formula (A1'): formula (I'):

[In the formula,
R ¹ is a hydrogen atom or a methyl group and
R ² is a trimethylene group
R ³ is a C1-C4 alkyl group (for example, a methyl group, an ethyl group, a propyl group, etc., preferably a methyl group) or a C1-C4 alkoxy group (for example, a methoxy group, an ethoxy group, a propoxy group, etc.). A methoxy group is preferred)
R ⁴ is, C1 -C4 alkyl group (e.g., methyl group, an ethyl group, a propyl group, a methyl group is preferred), and
n is a value that makes the viscosity of (A1') 100 to 100,000 mPa · s)
The polyorganosiloxane represented by is particularly preferable.

Composition has a moisture curable, the increases viewpoint surface curability of the cured product which, at least one of R ³ is preferably a C1~C6 alkoxy group, all R ^3, C1 to It is particularly preferably a C6 alkoxy group.

In formula (I'), R ¹ is a methyl group or a hydrogen atom, R ² is a trimethylene group, R ³ is a methoxy group or a methyl group, R ⁴ is a methyl group, and n is (A1'). ) Is a value having a viscosity of 100 to 100,000 mPa · s, and polyorganosiloxane is preferable.

（式中、
Ｒ_ｂは、独立して、水素原子又はメチル基であり、
Ｑ_２は、独立して、Ｃ１〜Ｃ５アルキレン基であり、
Ｒ^１１は、独立して、Ｃ１〜Ｃ６アルキル基又はＣ６〜Ｃ１２アリール基であり、
Ｒ^１２は、独立して、Ｃ１〜Ｃ６アルキル基又はＣ６〜Ｃ１２アリール基であり、
Ｒ^１３は、独立して、Ｃ１〜Ｃ６アルキル基又はＣ６〜Ｃ１２アリール基であり、
ｐは、１〜１０であり、
ｑは、０〜１０であり、
ｒは、０〜１００であり、
ｓは、０〜１０であり、
ｐ／（ｐ＋ｑ＋ｒ＋ｓ）≧０．０２である）
で示される分岐状ポリオルガノシロキサンが好ましい。 As the branched (A), (A2) the following average formula:

(During the ceremony,
R _b is independently a hydrogen atom or a methyl group and
Q ₂ is independently a C1~C5 alkylene group,
R ¹¹ is independently a C1-C6 alkyl group or a C6-C12 aryl group.
R ¹² is independently a C1-C6 alkyl group or a C6-C12 aryl group.
R ¹³ is independently a C1-C6 alkyl group or a C6-C12 aryl group.
p is 1 to 10
q is 0 to 10,
r is 0 to 100,
s is 0 to 10
p / (p + q + r + s) ≧ 0.02)
The branched polyorganosiloxane represented by is preferred.

R _b is preferably a methyl group from the viewpoint of ease of synthesis and storage stability.
Q ₂ is synonymous with Q ₁ and the preferred range is also the same.

R ¹¹ is a C1-C6 alkyl group (for example, a methyl group, an ethyl group, a propyl group, an n-butyl group, an isobutyl group, an s-butyl group, a tert-butyl group, etc., preferably a methyl group). , Or a C6-C12 aryl group (for example, a phenyl group, a tolyl group, etc., preferably a phenyl group). A methyl group is preferable from the viewpoint of easiness of synthesis and economy, and a phenyl group is preferable from the viewpoint of obtaining an optical viewpoint and a high refractive index.
R ¹² and R ¹³ are synonymous with R ¹¹ and have the same preferred range.

p is preferably 1 to 8, and particularly preferably 1 to 5.
q is preferably 0 to 8, particularly preferably 0 to 5.
r is preferably 1 to 80, and particularly preferably 2 to 70.
s is preferably 0 to 8, particularly preferably 0 to 6.
From the viewpoint of obtaining good curability, p / (p + q + r + s) ≧ 0.06 is preferable, and p / (p + q + r + s) ≧ 0.10.

Examples of (A2) include branched polyorganosiloxane represented by the following average formula. However, if it exists in the average formula, it is assumed that q, r, and s are not 0.
{CH ₂ = C (CH ₃ ) -C (= O) -O- (CH ₂ ) ₃ SiO _3/2 } p {CH ₃ SiO _3/2 } q {(CH ₃ ) ₂ SiO} r {(CH ₃ ) ₃ ) ₃ SiO _1/2 } s
{CH ₂ = C (CH ₃ ) -C (= O) -O- (CH ₂ ) ₃ SiO _3/2 } p {(CH ₃ ) ₂ SiO} r {(CH ₃ ) ₃ SiO _1/2 } s
{CH ₂ = C (CH ₃ ) -C (= O) -O- (CH ₂ ) ₃ SiO _3/2 } p {CH ₃ SiO _3/2 } q {(CH ₃ ) ₃ SiO _1/2 } s
{CH ₂ = C (CH ₃ ) -C (= O) -O- (CH ₂ ) ₃ SiO _3/2 } p {CH ₃ SiO _3/2 } q {(CH ₃ ) ₂ SiO} r
{CH ₂ = C (CH ₃ ) -C (= O) -O- (CH ₂ ) ₃ SiO _3/2 } p {(CH ₃ ) ₃ SiO _1/2 } s
{CH ₂ = C (CH ₃ ) -C (= O) -O- (CH ₂ ) ₃ SiO _3/2 } p {CH ₃ SiO _3/2 } q
{CH ₂ = C (CH ₃ ) -C (= O) -O- (CH ₂ ) ₃ SiO _3/2 } p {(CH ₃ ) ₂ SiO} r
{CH ₂ = C (CH ₃ ) -C (= O) -O- (CH ₂ ) ₃ SiO _3/2 } p {Ph ₃ SiO _3/2 } q {(CH ₃ ) ₂ SiO} r {(CH ₃ ) ₃ ) ₃ SiO _1/2 } s
{CH ₂ = C (CH ₃ ) -C (= O) -O- (CH ₂ ) ₃ SiO _3/2 } p {Ph ₃ SiO _3/2 } q {(CH ₃ ) ₂ SiO} r
{CH ₂ = C (CH ₃ ) -C (= O) -O- (CH ₂ ) ₃ SiO _3/2 } p {Ph ₃ SiO _3/2 } q {(CH ₃ ) ₃ SiO _1/2 } s
{CH ₂ = C (CH ₃ ) -C (= O) -O- (CH ₂ ) ₃ SiO _3/2 } p {Ph ₃ SiO _3/2 } q
{CH ₂ = C (CH ₃ ) -C (= O) -O- (CH ₂ ) ₃ SiO _3/2 } p {CH ₃ SiO _3/2 } q {Ph ₂ SiO} r {(CH ₃ ) ₃ SiO _1/2 } s
{CH ₂ = C (CH ₃ ) -C (= O) -O- (CH ₂ ) ₃ SiO _3/2 } p {CH ₃ SiO _3/2 } q {Ph ₂ SiO} r
{CH ₂ = C (CH ₃ ) -C (= O) -O- (CH ₂ ) ₃ SiO _3/2 } p {Ph ₂ SiO} r {(CH ₃ ) ₃ SiO _1/2 } s
{CH ₂ = C (CH ₃ ) -C (= O) -O- (CH ₂ ) ₃ SiO _3/2 } p {Ph ₂ SiO} r
{CH ₂ = C (CH ₃ ) -C (= O) -O- (CH ₂ ) ₃ SiO _3/2 } p {CH ₃ SiO _3/2 } q {(CH ₃ ) ₂ SiO} r {Ph ₃ SiO _1/2 } s
{CH ₂ = C (CH ₃ ) -C (= O) -O- (CH ₂ ) ₃ SiO _3/2 } p {CH ₃ SiO _3/2 } q {Ph ₃ SiO _1/2 } s
{CH ₂ = C (CH ₃ ) -C (= O) -O- (CH ₂ ) ₃ SiO _3/2 } p {(CH ₃ ) ₂ SiO} r {Ph ₃ SiO _1/2 } s
{CH ₂ = C (CH ₃ ) -C (= O) -O- (CH ₂ ) ₃ SiO _3/2 } p {Ph ₃ SiO _1/2 } s
{CH ₂ = C (CH ₃ ) -C (= O) -O- (CH ₂ ) ₃ SiO _3/2 } p {PhSiO _3/2 } q {Ph ₂ SiO} r {(CH ₃ ) ₃ SiO _{1 / 2} } s
{CH ₂ = C (CH ₃ ) -C (= O) -O- (CH ₂ ) ₃ SiO _3/2 } p {PhSiO _3/2 } q {Ph ₂ SiO} r
{CH ₂ = C (CH ₃ ) -C (= O) -O- (CH ₂ ) ₃ SiO _3/2 } p {PhSiO _3/2 } q {(CH ₃ ) ₂ SiO} r {Ph ₃ SiO _{1 / 2} } s
{CH ₂ = C (CH ₃ ) -C (= O) -O- (CH ₂ ) ₃ SiO _3/2 } p {PhSiO _3/2 } q {Ph ₃ SiO _1/2 } s
{CH ₂ = C (CH ₃ ) -C (= O) -O- (CH ₂ ) ₃ SiO _3/2 } p {PhSiO _3/2 } q {Ph ₂ SiO} r {Ph ₃ SiO _1/2 } s

(A2) preferably has a weight average molecular weight of 500 to 100,000, more preferably 1,000 to 80,000, and particularly preferably 1,000 to 60,000. Here, the weight average molecular weight is set to a value using polystyrene as a calibration curve by gel permeation chromatography analysis (GPC).

(A) can be used alone or in combination of two or more. The composition preferably comprises only (A1) in (A), and particularly preferably comprises only (A1'). Further, from the viewpoint of increasing curability, (A) may be a combination of a linear polyorganosiloxane and a branched polyorganosiloxane.

<(B) (meth) fuzzy silica surface-treated with an organosilicon compound having an acryloyl group>
The composition comprises fumes silica surface-treated with an organosilicon compound having (B) (meth) acryloyl groups. (B) is a component that imparts low compression set to the cured product of the composition. Further, (B) is also a component that imparts compatibility and / or thixotropy improvement of the resin composition. The organosilicon compound having a (meth) acryloyl group is a surface treatment agent for fumes silica. (Meta) acryloyl groups are present on the surface of fumes silica surface-treated with this surface treatment agent.

Examples of the organic silicon compound having a (meth) acryloyl group include 3-acryloxypropyltrimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 2-acryloxyethyltrimethoxysilane, and 2-methacryloxyethyltrimethoxysilane. , 3-Acryloxypropyltriethoxysilane, 3-Methacryloxypropyltriethoxysilane, 2-Acryloxyethyltriethoxysilane, 2-Methacryloxyethyltriethoxysilane, 3-Acryloxypropylmethyldimethoxysilane, 3-Methyloxyloxy Examples thereof include propylmethyldimethoxysilane, 3-acryloxypropylmethyldiethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, and 3-acryloxypropyltrimethoxysilane and 3-methacryloxypropyltrimethoxysilane are preferable. The organosilicon compound having a (meth) acryloyl group can be used alone or in combination of two or more.

(B) may be fumigant silica surface-treated with an organosilicon compound having a (meth) acryloyl group and an organosilicon compound having no (meth) acryloyl group. When (B) is surface-treated with an organosilicon compound having no (meth) acryloyl group in addition to the organosilicon compound having a (meth) acryloyl group, a silanol group present on the surface of fumigant silica The amount of is very small. As a result, the compression set of the cured product (preferably the compression set in the heated state) becomes smaller, and the surface curability is enhanced. Examples of the organic silicon compound having no (meth) acryloyl group include organosilazanes such as hexamethyldisilazane, octamethyltrisilazane, and diphenyltetramethyldisilazane; methyltrimethoxysilane, methyltriethoxysilane, and ethyltrimethoxy. Organoalkoxysilanes such as silane, ethyltriethoxysilane, phenyltrimethoxysilane, dimethyldimethoxysilane; organochlorosilanes such as methyltrichlorosilane, dimethyldichlorosilane, trimethylchlorosilane, phenyltrichlorosilane; and partial hydrolysates thereof. Organosilazans and organochlorosilanes are preferred. The organosilicon compound having no (meth) acryloyl group can be used alone or in combination of two or more.

The BET specific surface area of (B) is not particularly limited, but is preferably 50 to 400 m ² / g. When the BET specific surface area is 50 m ² / g or more, a cured product having a smaller compression set tends to be obtained. The BET specific surface area is more preferably 100 to 350 m ² / g, and particularly preferably 140 to 300 m ² / g.

The pH of (B) is not particularly limited, but is preferably 5.0 to 9.0. The pH of (B) refers to the pH of a silica dispersion prepared at a concentration of 40 g / L using a 50% by volume methanol / ion exchange aqueous solution at 23 ° C. Normally, untreated silica has many silanol groups remaining on the surface, and the pH of the aqueous dispersion is acidic. Therefore, by chemically treating the silica surface, reducing the number of silanol groups, and setting the pH of the aqueous dispersion of silica to 5.0 to 9.0, it contributes to the development of thixotropy in the resin composition, and after coating, It is considered that it works effectively to suppress the flow out of the range. The pH is more preferably 5.5 to 9.0, and particularly preferably 6.0 to 9.0.

The carbon content of (B) is not particularly limited, but is preferably 2.0 to 10.0% by mass. When the carbon content of (B) is in the above range, the pH of the aqueous dispersion of silica tends to be in a desired range. The carbon content of (B) is more preferably 2.5 to 8.0% by mass. The carbon content of (B) is a value calculated by completely burning (B) at 800 ° C. and then detecting and quantifying carbon dioxide in the combustion gas component by a TCD gas chromatograph.

(Meth) As a method for surface treatment of the fumed silica powder with an organosilicon compound having an acryloyl group, BET specific surface area of preferably ^{50 m} 2 / g or more, particularly preferably fumed untreated 50 to 400 m ² / g There is a method in which silica powder and an organic silicon compound having a (meth) aerosol group are placed in a closed container, chemically reacted or physically adsorbed at a temperature of room temperature to 400 ° C., and then the decomposition products and the like are volatilized. In addition to this method, (A), the above-mentioned untreated aerosol silica powder, and an organosilicon compound having a (meth) acryloyl group are mixed with a kneader, a Banbury mixer, a double roll, a gate mixer, a planetary mixer, or the like. It is also possible to use a method of mixing and kneading, and then heat-treating at 50 ° C. to 200 ° C. for 1 to 20 hours at normal pressure or reduced pressure, if necessary, using the above-mentioned kneader, dryer or the like. When (B) is fumes silica further surface-treated with an organosilicon compound having no (meth) acryloyl group, the fumes silica is surface-treated with an organosilicon compound having no (meth) acryloyl group. As a method, silica powder treated with a treatment agent having a (meth) acryloyl group and an organosilicon compound having no (meth) acryloyl group are mixed and surface-treated, or untreated fumigant silica powder. A compound having a (meth) acryloyl group and an organosilicon compound having no (meth) acryloyl group may be mixed and surface-treated, but the treatment is performed with a treatment agent having a (meth) acryloyl group. It is preferable to perform surface treatment by mixing with silica powder. Further, as the (B) and the untreated aerosol silica powder, a commercially available material may be used.

(B) can be used alone or in combination of two or more.

<(C) Photoreactive initiator>
(C) Contains a photoreaction initiator. (C) is a component that functions as a radical initiator or a sensitizer when photocrosslinking (A) and (B). (C) is an aromatic hydrocarbon, acetophenone and its derivative, benzophenone and its derivative, o-benzoylbenzoic acid ester, benzoin and benzoin ether and its derivative, xanthone and its derivative, disfilled compound and quinone. Examples include compounds, halogenated hydrocarbons and amines, and organic peroxides. From the viewpoint of compatibility with silicone and stability, a compound containing a substituted or unsubstituted benzoyl group or an organic peroxide is more preferable.

Examples of (C) include acetophenone, propiophenone, 2-hydroxy-2-methylpropiophenone, 2,2-dimethoxy-1,2-diphenylethane-1-one (IRGACURE 651: manufactured by BASF), and the like. 2-Hydroxy-2-methyl-1-phenyl-propane-1-one (DAROCUR 1173: manufactured by BASF), 1-hydroxy-cyclohexyl-phenyl-ketone (IRGACURE 184: manufactured by BASF), 1- [4- (4) 2-Hydroxyethoxy) -phenyl] -2-hydroxy-2-methyl-1-propane-1-one (IRGACURE 2959: manufactured by BASF), 2-hirodoxy-1- {4- [4- (2-hydroxy-) 2-Methyl-propionyl) -benzyl] phenyl} -2-methyl-propane-1-one (IRGACURE 127: manufactured by BASF), 2-methyl-1- (4-methylthiophenyl) -2-morpholinopropane-1 -On (IRGACURE 907: manufactured by BASF), 2-benzyl-2-dimethylamino- (4-morpholinophenyl) -butanone-1 (IRGACURE 369: manufactured by BASF), 2- (dimethylamino) -2- [ (4-Methylphenyl) Methyl] -1- [4- (4-morpholinyl) phenyl] -1-butanone (IRGACURE 379: manufactured by BASF); 2,4,6-trimethylbenzoyl-diphenyl-phosphenyl oxide (LUCIRIN) TPO: manufactured by BASF), bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide (IRGACURE 819: manufactured by BASF); 1,2-octanedione, 1- [4- (phenylthio)-, 2 -(O-benzoyl oxime)] (IRGACURE OXE 01: manufactured by BASF), Etanone, 1- [9-ethyl-6- (2-methylbenzoyl) -9H-carbazole-3-yl]-, 1- (O) -Acetyloxym) (IRGACURE OXE 02: manufactured by BASF); Mixture of oxyphenylacetic acid, 2- [2-oxo-2-phenylacetoxyethoxy] ethyl ester and oxyphenylacetic acid, 2- (2-hydroxyethoxy) ethyl ester (IRGACURE 754: manufactured by BASF), Phenylglycolic acid methyl ester (DAROCUR MBF: manufactured by BASF), Ethyl-4-dimethylaminobenzoate (DAROCUR ED) B: BASF), 2-ethylhexyl-4-dimethylaminobenzoate (DAROCUR EHA: BASF), bis (2,6-dimethoxybenzoyl) -2,4,4-trimethyl-pentylphosphine oxide (CGI 403) : Made by BASF), benzoyl peroxide, cumene peroxide and the like.

From the viewpoint of compatibility and photoreactivity, acetophenone, propiophenone, 2-hydroxy-2-methylpropiophenone, 2,2-dimethoxy-1,2-diphenylethane-1-one (IRGACURE 651: manufactured by BASF) ), 2-Hydroxy-2-methyl-1-phenyl-propane-1-one (DAROCUR 1173: manufactured by BASF), 1-hydroxy-cyclohexyl-phenyl-ketone (IRGACURE 184: manufactured by BASF), 2-methyl- 1- (4-Methylthiophenyl) -2-morpholinopropane-1-one (IRGACURE 907: manufactured by BASF), 2-benzyl-2-dimethylamino- (4-morpholinophenyl) -butanone-1 (IRGACURE 369) : BASF), 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide (LUCIRIN TPO: BASF), bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide (IRGACURE 819: BASF) (Manufactured by the company) is preferable.

(C) can be used alone or in combination of two or more.

<Additional ingredients>
If necessary, the composition contains additional components such as a metal catalyst, a reaction inhibitor, reinforcing silica, a flame retardant-imparting agent, a heat resistance improver, a plasticizer, a colorant, an adhesive-imparting material, and a diluent. It can be contained within a range that does not impair the object of the present invention. The additional components may be used alone or in combination of two or more. The composition preferably further contains (D) a metal catalyst. When the composition further contains (D), the surface curability is enhanced.

<< (D) Metal catalyst >>
(D) is one or more metal catalysts selected from the group consisting of an organic tin compound and an organic titanium compound. (D) is preferably a component that serves as a curing catalyst for the condensation reaction of the alkoxy group of (A). (D) is such as dimethyltin dioleate, dimethyltin dilaurate, dibutyltin dilaurate, diphenyltin diacetate, dibutyltin oxide, dibutyltin dimethoxydo, dibutylbis (triethoxysiloxy) tin, dioctyltin dilaurate, dibutyltin diacetylacetonate Organic tin compounds; and organic titanium compounds such as tetrapropoxytitanium, tetrabutoxytitanium, tetraoctyl titanate, diisopropoxybis (ethylacetylacetonato) titanium. (D) can be used alone or in combination of two or more.

<Preferable composition, etc.>
The content of (B) in the composition is preferably 1 to 40 parts by weight , more preferably 2 to 35 parts by weight , based on 100 parts by weight of the total of (A) and (B). When the content of (B) in the composition is 1 part by weight or more, the compression set of the cured product of the composition tends to be further reduced, and when it is 40 parts by weight or less, the workability tends to be improved. There is.
The content of (C) in the composition is 100 parts by weight in total of (A) and (B) from the viewpoint of photoreaction initiation action, heat resistance at the time of curing and visibility (high transmittance and low fogging property). On the other hand, 0.01 to 5 parts by weight is preferable, and more preferably 0.05 to 3 parts by weight.
When the composition contains (D), the content of (D) in the composition is 0 with respect to a total of 100 parts by weight of (A) and (B) having an alkoxy group from the viewpoint of enhancing curability. It is preferably 0.01 to 5 parts by weight, more preferably 0.05 to 3 parts by weight.
When the composition contains additional components, the total content of the additional components in the composition is preferably 0.01-10 parts by weight relative to a total of 100 parts by weight of (A) and (B).
The composition can be obtained by blending (A) to (C) and any component.

<Curing method>
The composition can be cured by irradiating with ultraviolet rays. Examples of lamps in the reactive range of (C) include high-pressure mercury lamps (UV-7000) and metal halide lamps (MHL-250, MHL-450, MHL-150, MHL-) manufactured by Ushio, Inc. 70), Korea: Metal halide lamp (JM-MTL 2KW) manufactured by JM tech, UV irradiation lamp (OSBL360) manufactured by Mitsubishi Electric Corporation, UV irradiation machine (UD-20-2) manufactured by Nippon Battery Co., Ltd., Co., Ltd. Examples thereof include a fluorescent lamp (FL-20BLB) manufactured by Toshiba, an H valve, an H plus valve, a D valve, a Q valve, and an M valve manufactured by Fusion. Irradiation dose is preferably 100~10,000mJ / cm ^2, more preferably 300~5,000mJ / cm ^2, more preferably from 500~3,500mJ / cm ^2.

<Use>
The resin composition can be used as a potting agent, an adhesive, a packing agent, a liquid gasket agent and the like. The resin composition is preferably a potting agent or a liquid gasket agent for protecting electrical / electronic parts from dirt, water, moisture and the like. As a method of using the resin composition as a potting agent, an adhesive, a packing agent or a liquid gasket, a conventionally known method can be used. For example, a method can be used in which the resin composition is potted on a portion where protection of electrical / electronic parts is required, dried if necessary, and further irradiated with ultraviolet rays to cure the resin composition. Examples of electrical / electronic components include semiconductor devices, printed circuit boards, battery materials, and the like.

<Characteristics>
The composition and its cured product have the following suitable physical properties.

[E hardness after curing]
Since the E hardness of the composition after curing can be 3 to 80, the composition is preferable in that it can easily moderately relieve stress from the outside and suppress the permeation of water even under high temperature and high humidity. .. The E hardness is preferably 5 to 70.

[Elongation after curing]
Since the composition can have an elongation of 30% or more after curing, it is preferable in that it is excellent in stress relaxation from the outside and can secure deformation resistance. The elongation after curing is preferably 60% or more, and 90% or more is particularly preferable.

〔Strength〕
The composition has a high strength because the tensile strength after curing can be 0.3 or more. The tensile strength after curing is preferably 0.4 or more, and particularly preferably 0.5 to or more.

[Dischargeability]
The resin composition is used, for example, by using a discharge nozzle of a dispensing machine (for example, 18G or the like, which can be appropriately selected according to a discharge amount) and applying the resin composition within a specific range such as a substrate. The larger the discharge amount when the discharge nozzle is used, the faster the processing speed is preferable. The discharge property is evaluated by the discharge amount when a needle of 18 G is used and the needle is discharged for 10 seconds. The discharge amount is preferably 0.4 g or more, more preferably 0.5 g or more, and further preferably 0.7 g or more.

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples. Parts and% represent parts by mass and% by mass unless otherwise specified. The present invention is not limited to these examples. Curing of each composition prepared in Examples and Comparative Examples was carried out using Ushio, Inc.: UVL-4001M at an ultraviolet energy irradiation amount of 120 w / cm ² and an integrated light amount of 3,000 mJ / cm ² . ..

[Evaluation conditions for physical properties]

(1) Compressive permanent strain The compressive permanent strain was measured according to JIS K 6262. The test condition temperature is three conditions of room temperature (23 ° C.), 120 ° C., and 180 ° C., and the curing time is a value of 24 hours.

(2) Surface hardening The surface of the composition after irradiation with ultraviolet rays under the above conditions was observed and evaluated according to the following criteria. “0” means that the surface curability is inferior, and as the number increases to “8”, the surface curability becomes excellent.
0: Surface uncured, a lot of liquids 1: Surface uncured, slightly liquid 2: Very adhesive 3: Adhesive 4: Adhesive, tacky feeling 5: Tacky feeling 6: Somewhat tacky feeling 7: Rubbery 8: Tucky No feeling (3) E hardness after curing After curing the composition under the above conditions, a dumbbell-shaped test piece (dumbbell-shaped No. 2 type) was prepared in accordance with JIS K 6250. Using the test piece thus obtained, the E hardness after curing at 23 ° C. was measured according to JIS K 6253 E.

(4) Strength and elongation after curing A dumbbell-shaped test piece (dumbbell-shaped No. 2 type) was prepared in the same manner as in “(3) E hardness after curing”. Using the test piece thus obtained, the tensile strength and elongation after curing at 23 ° C. were measured with a shopper tensile tester (manufactured by Toyo Seiki Seisakusho Co., Ltd.) in accordance with JIS K 6251.

(5) Discharge amount Using a double-threaded screw plastic needle (manufactured by Musashi Engineering Co., Ltd .: needle length 12.7 mm, gauge: 18 G (inner diameter 0.84 mm, outer diameter 1.27 mm), the resin composition is discharged for 10 seconds. The mass (g) at the time of production was taken as the discharge amount. If the discharge amount is 0.4 g or more, it is practical, preferably 0.5 g or more, more preferably 0.7 g or more, immediately after production and at room temperature. The discharge amount of the resin composition after storage for 4 weeks was measured.

(6) The discharge amount of the resin composition after being left at 50 ° C. for 10 days was measured according to "(5) Discharge amount".

[Ingredients used]
Each component in Examples and Comparative Examples is as follows.
(1) (A) (Meta) Polyorganosiloxane (a-1) containing an acryloyloxy group A linear polydimethylsiloxane (viscosity 1,020 mPa · s) in which both ends are clogged with a methacryloxypropyl dimethoxysilyl group. )
(A-2) Linear polydimethylsiloxane (viscosity 5,120 mPa · s) in which both ends are closed with a methacryloxypropyl dimethoxysilyl group.
(A-3) Linear polydimethylsiloxane (viscosity 2,200 mPa · s) in which both ends are closed with a metachloroxypropyldimethylsilyl group.
(A-4) Linear polydimethylsiloxane (viscosity 10,580 mPa · s) in which both ends are closed with a methacryloxypropyldimethylsilyl group.
(A-5) Linear polydimethylsiloxane (viscosity 980 mPa · s) in which both ends are closed with an acryloxypropyl dimethoxysilyl group.
(A-6) Linear polydimethylsiloxane (viscosity 5,090 mPa · s) in which both ends are closed with an acryloxypropyl dimethoxysilyl group.
(A-7) Linear polydimethylsiloxane (viscosity 9,780 mPa · s) in which both ends are closed with an acryloxypropyl dimethoxysilyl group.

(2) (B) (Meta) fumic silica surface-treated with an organosilicon compound having an acryloyl group The pH of (B) is 40 g / L using a 50% by volume methanol / ion exchange aqueous solution. It is a pH value at 23 ° C. of the silica dispersion prepared to the concentration.
(B-1) 3-methacryloxypropyltrimethoxysilane-treated fumed silica: BET specific surface area 144 m ² / g (AEROSIL R7200, manufactured by Nippon Aerosil), pH 4.6, carbon content 5.6 mass%
(B-2) BET specific surface area of 200 meters ² / g of fumed silica (AEROSIL 200, manufactured by Nippon Aerosil), and 3-methacryloxypropyl trimethoxy silane, then fumed silica treated with di methyldichlorosilane: BET ratio Surface area 158 m ^{2 /} g, pH 6.1, carbon content 4.4 mass%
(B-3) BET specific surface area of 200 meters ² / g of fumed silica (AEROSIL 200, manufactured by Nippon Aerosil), and 3-methacryloxypropyl trimethoxy silane, then fumed silica treated with di methyldichlorosilane: BET ratio Surface area 161 m ^{2 /} g, pH 6.1, carbon content 4.1 mass%
(B-4) BET specific surface area 200 m ² / g aerosol silica (AEROSIL 200, manufactured by Nippon Aerosil) treated with 3-methacryloxypropyltrimethoxysilane and then trimethylchlorosilane: fumes silica: BET specific surface area 142 m ^{2 /} g, pH 6.1, carbon content 4.9% by mass
(B-5) BET specific surface area 200 m ² / g of aerosol silica (AEROSIL 200, manufactured by Nippon Aerosil) treated with 3-methacryloxypropyltrimethoxysilane and trimethylchlorosilane: fumes silica: BET specific surface area 143 m ² / g, pH 6.2, carbon content 4.7% by mass
(B-6) BET specific surface area 200 m ² / g aerosol silica (AEROSIL 200, manufactured by Nippon Aerosil) treated with 3-methacryloxypropyltrimethoxysilane and hexamethyldisilazane: BET specific surface area 142 m ^{2 /} g, pH 5.3, carbon content 5.2% by mass
(B-7) BET specific surface area 130 m ² / g aerosol silica (AEROSIL 130, manufactured by Nippon Aerosil) treated with 3-methacryloxypropyltrimethoxysilane and hexamethyldisilazane: BET specific surface area 102 m ^{2 /} g, pH 5.6, carbon content 2.9% by mass
(B-8) BET specific surface area 300 m ² / g aerosol silica (AEROSIL 300, manufactured by Nippon Aerosil) treated with 3-methacryloxypropyltrimethoxysilane and hexamethyldisilazane: BET specific surface area 187 m ^{2 /} g, pH 6.0, carbon content 6.5% by mass
(3) Fumed silica other than (B') and (B) (b'-1) Fumed silica treated with dimethyldichlorosilane: BET specific surface area 170 m ² / g (AEROSIL R974, manufactured by Nippon Aerosil), pH 4.7 , Carbon content 1.1% by mass
(B'-2) BET specific surface area of 200 meters ² / g of fumed silica (AEROSIL 200, manufactured by Nippon Aerosil), and fumed silica treated with hexamethyldisilazane: BET specific surface area 135m ² /g,pH6.8, Carbon content 3.9% by mass

(4) (C) Photoreactive initiator (c-1) Bis (2,4,6-trimethylbenzoyl) -Phenylphosphine oxide (Irgacure 819)
(C-2) 2-Hydroxy-methylpropiophenone (DaroCure 1173)

(5) (D) Metal catalyst (d-1) Organic titanium compound: Tetraoctyl titanate (Organics TA-30: manufactured by Matsumoto Fine Chemical Co., Ltd.)
(D-2) Organic tin compound: Dibutyl tin diacetylacetonate (Neostan U-220: manufactured by Nitto Kasei Co., Ltd.)

[Example 1]
(Preparation of composition)
900 g of (a-1) and 100 g of (b-1) were placed in a 3 L universal mixing stirrer (manufactured by Dalton) and mixed uniformly for 30 minutes at room temperature (22 ° C.) under rotating conditions with a low-speed lever. After mixing uniformly, heating and mixing was performed at 120 ° C. for 2 hours. After cooling, a dissolved mixture consisting of 1.0 g of (c-1) and 5.0 g of (c-2) was added under UV blocking, and the mixture was uniformly mixed under cooling and reduced pressure for 30 minutes under rotating conditions with a low-speed lever. Then, foreign matter and the like were removed with a washed 200-mesh wire mesh to obtain a resin composition.

In the same manner as in Example 1, the compositions of Examples and Comparative Examples were prepared with the formulations shown in Tables 1 to 5, and their physical properties were evaluated. The results are shown in Tables 1-5. The addition of (d-1) and (d-2) was carried out at the same stage as the addition of the dissolved mixture consisting of (c-1) and (c-2).

From Tables 1 to 4, all of the compositions of Examples gave a cured product capable of exhibiting good curability by irradiation with ultraviolet rays and having a small compression set.
Example 2 and Example 4 (Example 3 and 5, Example 7 and Example 9, Example 8 and Example 10, Example 12 and Example 14, Example 13 and Example 15, Example Comparing 17 with Example 19 and Example 18 with Example 20), the composition containing a siloxane having an acryloyloxy group has a surface curability as compared with the composition containing a siloxane having a methacryloyloxy group. Has increased and the strength has increased.
By comparison with Examples 2 and 29, Examples 30 and 31, and Examples 4 and 32 and 33, the composition containing the high viscosity (A) was found to have a compression set (particularly at 120 ° C. and 180 ° C.). Compressed permanent strain) gave a smaller cured product.
Comparing Example 31 and Example 33, when the composition further contains a siloxane having an alkoxy group and a curing catalyst, the composition has moisture curability and is therefore more excellent in surface curability.
By comparison with Examples 2 and 17 (Examples 3 and 18), it contains fumigant silica surface-treated with an organosilicon compound having a (meth) acryloyl group and an organosilicon compound having no (meth) acryloyl group. The composition is a cured product having a smaller compression set (particularly, compression set at 120 ° C.) than the composition containing fumigant silica surface-treated only with an organosilicon compound having a (meth) acryloyl group. The surface curability of the composition was enhanced.
By comparison of Examples 1 to 3 (Examples 6 to 8, Examples 11 to 13, and Examples 16 to 18), the surface curability was improved when the composition further contained a metal catalyst.
Since Comparative Examples 1 to 6 are silica-free compositions, the compositions of Comparative Examples 1 to 6 gave a cured product having a large compression set.
Since Comparative Examples 8 to 9 and 11 to 12 are compositions containing an organosilicon compound having no (meth) acryloyl group as the surface treatment compound of silica, the compositions of Comparative Examples 8 to 9 and 11 to 12 are , A cured product having a large compression set was given. Further, by comparing Comparative Example 7 and Comparative Examples 8 to 9 (Comparative Examples 10 and 11 to 12), the surface curability of the composition of Comparative Example was not enhanced by the metal catalyst.

The present invention is an ultraviolet curable silicone resin composition which can exhibit good curability by irradiation with ultraviolet rays and gives a cured product having a small compression set, and in particular, a potting agent, an adhesive, and the like. It can be suitably used as a packing agent, a liquid gasket agent, and the like.

Claims (7)

(A) Polyorganosiloxane containing (meth) acryloyloxy group;
Ultraviolet curable silicone containing (B) an organosilicon compound having a (meth) acryloyl group and an organosilicon compound having no (meth) acryloyl group ; and (C) a photoreaction initiator. A UV-curable silicone resin composition, wherein the content of (B) in the composition is 1 to 40 parts by weight with respect to 100 parts by weight in total of (A) and (B). .. (A) is the formula (I) of (A1):

[In formula (I),
R is independently a C1-C6 alkyl group, a C6-C12 aryl group, a C1-C6 alkoxy group or formula (a):

(Here, _Ra is independently a hydrogen atom or methyl, and
Q ₁ is, independently is a group represented by a is) C1 to C5 alkylene group,
At least one R is a group represented by the formula (a).
n is a value that makes the viscosity of (A1) 100 to 100,000 mPa · s]
The silicone resin composition according to claim 1, which is a linear polyorganosiloxane represented by. The silicone resin composition according to claim 2, wherein at least one R is a C1 to C6 alkoxy group. The silicone resin composition according to any one of claims 1 to 3 , wherein the BET specific surface area of (B) is 50 to 400 m ² / g. The silicone resin composition according to any one of claims 1 to 4 , wherein the content of (C) is 0.01 to 5 parts by weight with respect to a total of 100 parts by weight of (A) and (B). .. The silicone resin composition according to any one of claims 1 to 5 , further comprising one or more (D) metal catalysts selected from the group consisting of an organic tin compound and an organic titanium compound. The silicone resin composition according to any one of claims 1 to 6 , which is a potting agent, an adhesive, a packing agent or a liquid gasket agent.