JP6645823B2 - Addition-curable polyfluoroorganosiloxane composition - Google Patents

Description

  The present invention relates to a cured product of an addition-curable polyfluoroorganosiloxane composition.

  2. Description of the Related Art In a display device such as a mobile phone provided with a display component such as a liquid crystal module, a glass or resin screen is installed on the front surface of the display device for the purpose of protecting the display device and improving design. The screen and the display device are generally bonded together using an adhesive.

  As such an adhesive, Patent Documents 1 and 2 disclose a two-component addition reaction type fluorosilicone rubber composition which is cured by heating.

JP-A-1-204569 JP 2004-272059 A

  The flexibility of the cured product obtained using the compositions described in Patent Documents 1 and 2 decreases over time. In particular, when the cured product is subjected to heat treatment, the flexibility of the cured product becomes extremely low. When the flexibility of the cured product decreases, the cured product becomes harder. Therefore, the cured product of the composition bonded to the PMMA (polymethyl methacrylate) panel and the LCD (liquid crystal display) panel cannot reduce the warping stress of the PMMA. Therefore, there is a problem that the resin cracks or peels off from the panel.

  An object of the present invention is to provide a polyorganosiloxane composition which gives a cured product having a small rate of change in flexibility even when the cured product is subjected to heat treatment.

（式中、
Ｒ^ｄ１は、水素原子であり、
Ｒ^ｅ２は、独立して、Ｃ_１−Ｃ_６フルオロアルキル基、Ｃ_１−Ｃ_６アルキル基又はＣ_６−Ｃ_２０アリール基であり、少なくとも１つのＲ^ｅ２は、Ｃ_１−Ｃ_６フルオロアルキル基であり、
ｍ３は、２３℃における粘度を１〜１０，０００ｃＰとする数である）である、直鎖状ポリオルガノハイドロジェンシロキサンを含む、ポリオルガノハイドロジェンシロキサン；及び
（Ｃ）白金系触媒
を含み、
（Ａ）のアルケニル基の個数Ｖｉ_Ａに対する、（Ｂ）のケイ素原子に結合した水素原子の個数Ｈ_Ｂの比が０．８０以下であり、
（Ｃ）が、白金系金属原子として、０．５〜１，０００ｐｐｍである、
硬化性ポリオルガノシロキサン組成物。
［２］（Ｂ）が、（Ｂ２）Ｒ^ｄ３Ｒ^ｆ１ＳｉＯ_２／２単位（式中、Ｒ^ｄ３は、水素原子であり、Ｒ^ｆ１は、水素原子、Ｃ_１−Ｃ_６アルキル基、Ｃ_１−Ｃ_６フルオロアルキル基又はＣ_６−Ｃ_２０アリール基である）、及び、場合によりＲ^ｅ４ _２ＳｉＯ_２／２単位（式中、Ｒ^ｅ４は、独立して、Ｃ_１−Ｃ_６アルキル基、Ｃ_１−Ｃ_６フルオロアルキル基又はＣ_６−Ｃ_２０アリール基である）からなり、一分子中に、ケイ素原子に結合した水素原子を２個以上有し、２３℃における粘度が１〜１０，０００ｃＰである、環状ポリオルガノハイドロジェンシロキサン；及び
（Ｂ３）Ｒ^ｄ４Ｒ^ｆ２ _２ＳｉＯ_１／２単位（式中、Ｒ^ｄ４は、水素原子であり、Ｒ^ｆ２は、独立して、水素原子、Ｃ_１−Ｃ_６アルキル基、Ｃ_１−Ｃ_６フルオロアルキル基又はＣ_６−Ｃ_２０アリール基である）及びＳｉＯ_４／２単位からなり、一分子中に、ケイ素原子に結合した水素原子を２個以上有し、２３℃における粘度が１〜１０，０００ｃＰである、環状ポリオルガノハイドロジェンシロキサンからなる群より選択される１以上を含む、［１］の硬化性ポリオルガノシロキサン組成物。
［３］（Ｂ）が、（Ｂ４）両末端がＲ^ｅ５ _３ＳｉＯ_１／２単位で閉塞され、中間単位がＲ^ｄ５Ｒ^ｅ６ＳｉＯ_２／２単位及びＲ^ｅ７ _２ＳｉＯ_２／２単位（式中、Ｒ^ｄ５は、水素原子であり、Ｒ^ｅ５、Ｒ^ｅ６及びＲ^ｅ７は、それぞれ独立して、Ｃ_１−Ｃ_６アルキル基、Ｃ_１−Ｃ_６フルオロアルキル基又はＣ_６−Ｃ_２０アリール基である）からなり、２３℃における粘度が１〜１０，０００ｃＰである、直鎖状ポリオルガノハイドロジェンシロキサン；及び
（Ｂ５）両末端がＲ^ｄ６Ｒ^ｅ８ _２ＳｉＯ_１／２単位で閉塞され、中間単位がＲ^ｄ７Ｒ^ｅ９ＳｉＯ_２／２単位及びＲ^ｅ１０ _２ＳｉＯ_２／２単位（式中、Ｒ^ｄ６及びＲ^ｄ７は、水素原子であり、Ｒ^ｅ８、Ｒ^ｅ９及びＲ^ｅ１０は、それぞれ独立して、Ｃ_１−Ｃ_６アルキル基、Ｃ_１−Ｃ_６フルオロアルキル基又はＣ_６−Ｃ_２０アリール基である）からなり、２３℃における粘度が１〜１０，０００ｃＰとする数である）である、直鎖状ポリオルガノハイドロジェンシロキサンからなる群より選択される１以上を含む、［１］又は［２］の硬化性ポリオルガノシロキサン組成物。
［４］（Ｂ）が、（Ｂ６）Ｒ^ｄ８Ｒ^ｆ３ _２ＳｉＯ_１／２単位（式中、Ｒ^ｄ８は、水素原子であり、Ｒ^ｆ３は、独立して、水素原子、Ｃ_１−Ｃ_６アルキル基、Ｃ_１−Ｃ_６フルオロアルキル基又はＣ_６−Ｃ_２０アリール基である）及びＳｉＯ_４／２単位からなり、一分子中に、ケイ素原子に結合した水素原子を３個以上有する分岐状ポリオルガノハイドロジェンシロキサン；及び
（Ｂ７）Ｒ^ｆ４ _３ＳｉＯ_１／２単位、Ｒ^ｆ５ＳｉＯ_３／２単位、及び、場合によりＲ^ｆ６ _２ＳｉＯ_２／２単位（式中、Ｒ^ｆ４、Ｒ^ｆ５及びＲ^ｆ６は、それぞれ独立して、水素原子、Ｃ_１−Ｃ_６アルキル基、Ｃ_１−Ｃ_６フルオロアルキル基又はＣ_６−Ｃ_２０アリール基を表す）からなり、一分子中に、ケイ素原子に結合した水素原子を２個以上有する分岐状ポリオルガノハイドロジェンシロキサンからなる群より選択される１以上を含む、［１］〜［３］のいずれかの硬化性ポリオルガノシロキサン組成物。
［５］（Ａ）が、式（ａ３）：

（式中、
Ｒ^ａ２は、独立して、Ｃ_２−Ｃ_６アルケニル基であり、
Ｒ^ｂ３は、独立して、Ｃ_１−Ｃ_６フルオロアルキル基であり、
Ｒ^ｃ３は、独立して、Ｃ_１−Ｃ_６アルキル基又はＣ_６−Ｃ_２０アリール基であり、
Ｒ^ｅ１は、独立して、Ｃ_１−Ｃ_６フルオロアルキル基、Ｃ_１−Ｃ_６アルキル基又はＣ_６−Ｃ_２０アリール基であり、
ｍ１＋ｍ２は２３℃における粘度を１以上１００，０００ｃＰ未満とする値である）
で示されるアルケニル基含有ポリオルガノシロキサンである、［１］〜［４］のいずれかの硬化性ポリオルガノシロキサン組成物。
［６］［１］〜［５］のいずれかの硬化性ポリオルガノシロキサン組成物からなる画像表示装置用シール剤。 The present invention includes the following.
[1] (A) an alkenyl group-containing polyorganosiloxane having a viscosity of 1 to 100,000 cP at 23 ° C. and containing two or more alkenyl groups and one or more fluorine-containing groups in a molecule;
(B) A polyorganohydrogensiloxane having two or more hydrogen atoms bonded to a silicon atom in a molecule, wherein (B) is a compound represented by the following formula (B1):

(Where
R ^d1 is a hydrogen atom,
R ^e2 is independently a C ₁ -C ₆ fluoroalkyl group, a C ₁ -C ₆ alkyl group or a C ₆ -C ₂₀ aryl group, and at least one ^{Re 2} is a C ₁ -C ₆ fluoroalkyl group. And
m3 is a number having a viscosity of 1 to 10,000 cP at 23 ° C.), including a polyorganohydrogensiloxane including a linear polyorganohydrogensiloxane; and (C) a platinum-based catalyst,
To the number Vi _A alkenyl group (A), or less the ratio of the number _{H B} of hydrogen atoms bonded to silicon atoms is 0.80 (B),
(C) is 0.5 to 1,000 ppm as a platinum-based metal atom;
A curable polyorganosiloxane composition.
[2] (B) is (B2) R ^d3 R ^f1 SiO _2/2 unit (where R ^d3 is a hydrogen atom, and R ^f1 is a hydrogen atom, a C ₁ -C ₆ alkyl group, C ₁ -C ₆ fluoroalkyl group or a _C 6 _{-C 20} aryl group), and, ^R _e4 2 _{SiO 2/2} units (wherein ^{optionally, R e4} are _{independently,} C 1 -C ₆ alkyl, A C ₁ -C ₆ fluoroalkyl group or a C ₆ -C ₂₀ aryl group), has two or more hydrogen atoms bonded to a silicon atom in one molecule, and has a viscosity of 1 to 10 at 23 ° C. is 000 cP, cyclic polyorganohydrogensiloxane; and ^(B3) in _R d4 _R f2 _{2 SiO 1/2} units ^{(wherein, R d4} is a hydrogen ^{atom, R f2} is independently a hydrogen atom, C ₁ -C ₆ alkyl _groups, C 1 -C Is a fluoroalkyl group or a _C 6 _{-C 20} aryl group) and consists _{SiO 4/2} units, in a molecule, the hydrogen atoms bonded to silicon atoms have two or more, a viscosity at 23 ° C. 1 to 10 [1] The curable polyorganosiloxane composition according to [1], which comprises at least one selected from the group consisting of cyclic polyorganohydrogensiloxanes having a molecular weight of 2,000 cP.
[3] (B) is, (B4) both terminals blocked with ^R _e5 3 _{SiO 1/2} units, intermediate units ^R d5 ^R e6 _{SiO 2/2} units and ^R _e7 2 _{SiO 2/2} units (wherein , R ^d5 is a hydrogen atom, and R ^e5 , R ^e6 and R ^e7 are each independently a C ₁ -C ₆ alkyl group, a C ₁ -C ₆ fluoroalkyl group or a C ₆ -C ₂₀ aryl group. made from one), a viscosity at 23 ° C. is 1～10,000CP, linear polyorganohydrogensiloxane; and (B5) at both ends is closed by the ^R d6 ^R _e8 2 _{SiO 1/2} units, an intermediate unit There ^R d7 ^R e9 _{SiO 2/2} units and ^R _e10 2 _{SiO 2/2} units ^{(wherein, R d6} and ^{R d7} are hydrogen ^atom, R ^{e8, R e9} and ^{R e10} are each independently C ₁ -C ₆ Alkyl group _consists C 1 -C ₆ fluoroalkyl group or a _C 6 _{-C 20} aryl group), a viscosity of several to 1～10,000CP) at 23 ° C., linear polyorganohydrogen The curable polyorganosiloxane composition according to [1] or [2], comprising at least one selected from the group consisting of gensiloxanes.
[4] (B) _{^{is, (B6) R d8 R f3}} 2 SiO 1/2 units ^{(wherein, R d8} is a hydrogen ^{atom, R f3} is independently hydrogen _atom, C 1 -C ₆ An alkyl group, a C ₁ -C ₆ fluoroalkyl group or a C ₆ -C ₂₀ aryl group) and a SiO _4/2 unit, and each molecule has at least three hydrogen atoms bonded to a silicon atom. polyorganohydrogensiloxane; and _^(B7) R f4 _{3 SiO 1/2} ^units, R f5 _{SiO 3/2} units, and, ^R _f6 2 _{SiO 2/2} units (wherein ^optionally, R ^{f4, R f5} and R ^f6 are each independently a hydrogen _atom, C 1 -C ₆ alkyl _groups, C 1 -C represents a ₆ fluoroalkyl group or a _C 6 _{-C 20} aryl group) consists, in one molecule, bonded to the silicon atom Two hydrogen atoms Containing one or more selected from the group consisting of branched polyorganohydrogensiloxane having above [1] to either of the curable polyorganosiloxane composition of [3].
[5] (A) is the formula (a3):

(Where
R ^a2 is independently a C ₂ -C ₆ alkenyl group;
R ^b3 is independently a C ₁ -C ₆ fluoroalkyl group,
R ^c3 is independently a C ₁ -C ₆ alkyl group or a C ₆ -C ₂₀ aryl group;
R ^e1 is independently a C ₁ -C ₆ fluoroalkyl group, a C ₁ -C ₆ alkyl group or a C ₆ -C ₂₀ aryl group;
m1 + m2 is a value at which the viscosity at 23 ° C. is 1 or more and less than 100,000 cP)
The curable polyorganosiloxane composition according to any one of [1] to [4], which is an alkenyl group-containing polyorganosiloxane represented by the following formula:
[6] A sealant for an image display device comprising the curable polyorganosiloxane composition according to any one of [1] to [5].

  According to the present invention, there is provided a polyorganosiloxane composition which gives a cured product having a small rate of change in flexibility even when the cured product is subjected to heat treatment. As a result, even when the composition is cured and then further heated, a cured product capable of appropriately relaxing external stress and securing deformability can be obtained.

<Definition of terms>
The definitions of the terms used in this specification are as follows.
C ₂ -C ₆ alkenyl group, a linear or branched, for example, vinyl, allyl, 3-butenyl, 5-hexenyl. As the C ₂ -C ₆ alkenyl group, vinyl is preferable because it is easy to synthesize and does not impair the fluidity before curing or the heat resistance of the cured product.
The C ₁ -C ₆ fluoroalkyl group is linear or branched and includes, for example, trifluoromethyl, 3,3,3-trifluoropropyl (CF ₃ CH ₂ CH ₂ —) and the like. As the C ₁ -C ₆ fluoroalkyl group, 3,3,3-trifluoropropyl is preferable in terms of easy synthesis and excellent transparency.
The C ₁ -C ₆ alkyl group is linear or branched, and includes, for example, methyl, ethyl, propyl, butyl, pentyl, and hexyl. As the C ₁ -C ₆ alkyl group, methyl is preferable because it is easy to synthesize and has an excellent balance between fluidity and mechanical strength after curing.
The C ₆ -C ₂₀ aryl group is a monocyclic or polycyclic aromatic group, and includes, for example, phenyl, naphthyl, and anthracyl. The C ₆ -C ₂₀ aryl group is preferably a phenyl group in terms of easy synthesis, and excellent balance of fluidity and mechanical strength after curing.
The viscosity is a value measured at 23 ° C. using a rotational viscometer.

<Curable polyorganosiloxane composition>
Each component contained in the curable polyorganosiloxane composition (hereinafter, also simply referred to as “composition”) will be described.

1. (A) Alkenyl Group-Containing Polyorganosiloxane (A) The alkenyl group-containing polyorganosiloxane is a component serving as a base polymer in the composition. By blending (A), it is possible to secure a stable three-dimensional structure due to a crosslinking reaction during curing, control curing shrinkage, and secure good visibility. (A) has an average of two or more alkenyl groups bonded to a silicon atom in a molecule, and has an average of one or more fluorine-containing groups bonded to a silicon atom in the molecule. There is no particular limitation as long as a network structure can be formed by an addition reaction with.

Alkenyl group, a carbon - is not particularly limited as long as the hydrocarbon group containing a carbon double bond, C ₂ -C ₆ alkenyl groups are preferred. The fluorine-containing group is not particularly limited as long as it is a hydrocarbon group containing a fluorine atom, but is preferably a C ₁ -C ₆ fluoroalkyl group.

(A) is typically represented by the general formula (a1):
(R ^a1 ) _n1 (R ^b1 ) _n2 (R ^c1 ) _n3 SiO _{(4-n1-n2-n3) / 2} (a1)
(Where
R ^a1 is independently a C ₂ -C ₆ alkenyl group;
R ^b1 is independently a C ₁ -C ₆ fluoroalkyl group;
R ^c1 is independently a C ₁ -C ₆ alkyl group or a C ₆ -C ₂₀ aryl group;
n1 is 1 or 2;
n2 is an integer from 0 to 2;
n3 is an integer of 0 to 2, provided that n1 + n2 + n3 is 1 to 3)
Is an alkenyl group-containing polyorganosiloxane having an average of at least two alkenyl group-containing siloxane units in the molecule.

When (A) has, as an alkenyl group-containing siloxane unit, only a unit represented by the formula (a1) in which n2 is 0, this (A) is further converted to the formula (a2):
(R ^b2 ) _n4 (R ^c2 ) _n5 SiO _{(4-n4-n5) / 2} (a2)
(Where
R ^b2 is independently a C ₁ -C ₆ fluoroalkyl group;
R ^c2 is independently a C ₁ -C ₆ alkyl group or a C ₆ -C ₂₀ aryl group;
n4 is 1-3;
n5 is an integer of 0 to 2, provided that n4 + n5 is 1 to 3)
Has at least one fluoroalkyl group-containing siloxane unit in the molecule on average.

  The siloxane skeleton of (A) may be linear, branched, or a combination thereof. (A) is preferably straight-chain because synthesis and control of the average degree of polymerization are easy.

R ^a1 may be present at the terminal or in the middle of the polyorganosiloxane molecular chain of (A), or may be present at both. In order to impart excellent mechanical properties to the composition after curing, ^Ra1 is preferably present at both ends of the polyorganosiloxane molecular chain of (A).

  In the formula (a1), it is preferable that n1 is 1, n2 is 0, and n3 is 2 because of easy synthesis. Further, in the formula (a2), n4 is preferably 1 and n5 is preferably 1, because the synthesis is easy.

（式中、
Ｒ^ａ２は、独立して、Ｃ_２−Ｃ_６アルケニル基であり、
Ｒ^ｂ３は、独立して、Ｃ_１−Ｃ_６フルオロアルキル基であり、
Ｒ^ｃ３は、独立して、Ｃ_１−Ｃ_６アルキル基又はＣ_６−Ｃ_２０アリール基であり、
Ｒ^ｅ１は、独立して、Ｃ_１−Ｃ_６フルオロアルキル基、Ｃ_１−Ｃ_６アルキル基又はＣ_６−Ｃ_２０アリール基であり、
ｍ１＋ｍ２は２３℃における粘度を１以上１００，０００ｃＰ未満とする値である） (A) is preferably composed of an alkenyl group-containing polyorganosiloxane represented by the following formula (a3).

(Where
R ^a2 is independently a C ₂ -C ₆ alkenyl group;
R ^b3 is independently a C ₁ -C ₆ fluoroalkyl group,
R ^c3 is independently a C ₁ -C ₆ alkyl group or a C ₆ -C ₂₀ aryl group;
R ^e1 is independently a C ₁ -C ₆ fluoroalkyl group, a C ₁ -C ₆ alkyl group or a C ₆ -C ₂₀ aryl group;
m1 + m2 is a value at which the viscosity at 23 ° C. is 1 or more and less than 100,000 cP)

  The polyorganosiloxane represented by the formula (a3) may be a random copolymer or a block copolymer. That is, in the formula (a3), m1 and m2 indicate the number of the units defined by m1 and m2. In the formula (a3), the units defined by m1 and m2 may be the same or different.

In the formula (a3), R ^a2 is vinyl, R ^b3 is 3,3,3-trifluoropropyl, R ^c3 is methyl, R ^e1 is a C ₁ -C ₆ alkyl group (particularly methyl). Preferably it is. Therefore, (A) has (a4) both ends closed with a dimethylvinylsiloxane unit, an intermediate unit composed of a dimethylsiloxane unit and a 3,3,3-trifluoropropylmethylsiloxane unit, and a viscosity at 23 ° C. of 1 or more. More preferably, it comprises an alkenyl group-containing polyorganosiloxane having a viscosity of less than 100,000 cP.

  When (A) comprises (a3) or (a4), the composition does not include an alkenyl group-containing polyorganosiloxane other than (a3) or (a4), for example, a branched alkenyl group-containing polyorganosiloxane.

  The number of alkenyl groups bonded to silicon atoms in (A) is preferably 2 to 100 on average and more preferably 2 to 50 in one molecule.

  (A) has a viscosity at 23 ° C. of preferably 1 or more and less than 100,000 cP, more preferably 10 to 50,000 cP, and more preferably 100 to 25,000 cP, from the viewpoint of workability. Particularly preferred. It is preferable to adjust the weight average molecular weight of (A) so as to fall within these viscosity ranges.

2. (B) Polyorganohydrogensiloxane (B) The polyorganohydrogensiloxane is obtained by subjecting a hydrosilyl group contained in the molecule to an addition reaction with ^Ra1 in (A), whereby the chain extender of (A) is obtained. And / or function as a crosslinking agent.

（式中、
Ｒ^ｄ１は、水素原子であり、
Ｒ^ｅ２は、独立して、Ｃ_１−Ｃ_６フルオロアルキル基、Ｃ_１−Ｃ_６アルキル基又はＣ_６−Ｃ_２０アリール基であり、少なくとも１つのＲ^ｅ２は、Ｃ_１−Ｃ_６フルオロアルキル基であり、
ｍ３は、２３℃における粘度を１〜１０，０００ｃＰとする数である）である、直鎖状ポリオルガノハイドロジェンシロキサンを含む。 (B) is a formula (B1) of (B1)

(Where
R ^d1 is a hydrogen atom,
R ^e2 is independently a C ₁ -C ₆ fluoroalkyl group, a C ₁ -C ₆ alkyl group or a C ₆ -C ₂₀ aryl group, and at least one ^{Re 2} is a C ₁ -C ₆ fluoroalkyl group. And
m3 is a number having a viscosity of 1 to 10,000 cP at 23 ° C.).

  The polyorganosiloxane represented by the formula (b1) may be a random copolymer or a block copolymer. That is, in the formula (b1), m3 indicates the number of the units defined by m3. In the formula (b1), the units defined by m3 may be the same or different.

(B1) has one or more C ₁ -C ₆ fluoroalkyl groups bonded to a silicon atom in one molecule, and has two H groups bonded to silicon atoms at both ends. The hydrosilyl group contained in (B1) undergoes an addition reaction with ^Ra1 in (A) to function as a chain extender in (A). If (B1) contains only a polyorganohydrogensiloxane having three or more H groups bonded to a silicon atom in one molecule, the cured product is reticulated, and the crosslink density becomes too high. Thereby, after the composition is thermally cured, the resistance to deformation when further heated is inferior. When (B1) is a linear polyorganohydrogensiloxane having no C ₁ -C ₆ fluoroalkyl group, it is not compatible with (A), which is a base polymer containing a fluorine-containing group.

R ^e2, since synthesis is _easy, C 1 -C ₆ fluoroalkyl group and a _C 1 -C ₆ alkyl group, and more preferably methyl and 3,3,3-trifluoropropyl. _Also, ^{R e2} is C 1 -C ₆ fluoroalkyl group is preferably present in the unit defined in m3.

(B1) is, both ends are closed by ^R d1 ^R _e2 2 _{SiO 1/2} units, in the intermediate unit ^R b4 ^R c4 _{SiO 2/2} units ^{(wherein, R d1} is a hydrogen ^{atom, R e2} is Is independently a C ₁ -C ₆ fluoroalkyl group, a C ₁ -C ₆ alkyl group or a C ₆ -C ₂₀ aryl group, and R ^b4 is independently a C ₁ -C ₆ fluoroalkyl group. , R ^c4 is independently a C ₁ -C ₆ alkyl group or a C ₆ -C ₂₀ aryl group), and has a viscosity at 23 ° C. of 1 to 10,000 cP, a linear polyorganohydrogen. Preferably it is a siloxane. (B1) has both ends capped with a dimethylhydrogensiloxane unit, an intermediate unit comprising a 3,3,3-trifluoropropylmethylsiloxane unit, and a viscosity at 23 ° C. of 1 to 10,000 cP. More preferably, it is a linear polyorganohydrogensiloxane.

  In (B1), the lower limit of the viscosity at 23 ° C. may be 10 cP or more, or 200 cP or more. In (B1), the upper limit of the viscosity at 23 ° C. may be 1,000 cP or less, or may be 500 cP. The range of the viscosity of (B1) may be 1 to 1,000 cP, 1 to 500 cP, 10 to 1,000 cP, 200 to 10,000 cP, and 200 to 500 cP. When the viscosity of (B1) is from 200 to 10,000 cP, a cured product having a smaller rate of change in flexibility of the heat treatment tends to be obtained. When the viscosity of (B1) is from 1 to 500 cP, the quick-curing property is increased, and a more flexible cured product tends to be obtained. When the viscosity of (B1) is from 200 to 500 cP, a cured product having a smaller rate of change in the flexibility of the heat treatment is obtained, the rapid curability is increased, and a more flexible cured product tends to be obtained.

2-1. Further polyorganohydrogensiloxanes other than (B1) further have two or more (for example, three or more) H groups bonded to silicon atoms other than (B1) in a molecule. Polyorganohydrogensiloxane (hereinafter, also referred to as “further (B)”) may be included. However, (B) may consist of (B1).

  When the further (B) is a polyorganohydrogensiloxane having more than two H groups bonded to a silicon atom in one molecule, the cured product can be reticulated. Further, when (B) is a polyorganohydrogensiloxane having two H groups bonded to a silicon atom in one molecule, it functions as a chain extender similarly to (B1). A cured product having better flexibility is obtained later.

Such further (B) is typically represented by the general formula (b1 ′):
( ^Rd2 ) _n6 ( ^Re3 ) _{n7SiO (4-n6-n7) / 2} (b1 ')
(Where
R ^d2 is a hydrogen atom,
R ^e3 is independently a C ₁ -C ₆ alkyl group, a C ₁ -C ₆ fluoroalkyl group or a C ₆ -C ₂₀ aryl group;
n6 is 1 or 2;
n7 is an integer of 0 to 2, provided that n6 + n7 is 1 to 3)
Has two or more units in the molecule. However, further (B) does not include (B1).

  In the formula (b1 ′), n6 is preferably 1 because synthesis is easy.

  Such further (B) includes one or more selected from the group consisting of cyclic polyorganohydrogensiloxanes, linear polyorganohydrogensiloxanes, and branched polyorganohydrogensiloxanes. One or more selected from the group consisting of an organohydrogensiloxane and a cyclic polyorganohydrogensiloxane is preferred, and a linear polyorganohydrogensiloxane is more preferred.

2-2 (1). Annular further (B): (B2) and (B3)
If further (B) is annular,
(B2) R ^d3 R ^f1 SiO _2/2 unit (where R ^d3 is a hydrogen atom, and R ^f1 is a hydrogen atom, a C ₁ -C ₆ alkyl group, a C ₁ -C ₆ fluoroalkyl group or a C ₁ -C ₆ fluoroalkyl group) ₆ -C ₂₀ aryl group), and, ^R _e4 2 _{SiO 2/2} units (wherein ^{optionally, R e4} are _{independently,} C 1 -C _{6 alkyl,} C 1 -C ₆ fluoroalkyl group Or a C ₆ -C ₂₀ aryl group), having two or more hydrogen atoms bonded to a silicon atom in one molecule and having a viscosity at 23 ° C. of 1 to 10,000 cP. siloxane; and ^(B3) in _R d4 _R f2 _{2 SiO 1/2} units ^{(wherein, R d4} is a hydrogen ^{atom, R f2} is independently a hydrogen _atom, C 1 -C ₆ alkyl, C ₁ -C ₆ fluoroalkyl Is a group or a _C 6 _{-C 20} aryl group) and consists _{SiO 4/2} units, in a molecule, the hydrogen atoms bonded to silicon atoms have two or more, a viscosity at 23 ℃ 1~10,000cP And at least one selected from the group consisting of cyclic polyorganohydrogensiloxanes.

(B2) ^consists either R ^d3 R f1 _{SiO 2/2} ^units, consisting of R ^d3 R f1 _{SiO 2/2} units and ^R _e4 2 _{SiO 2/2} units. The number of hydrogen atoms in (B2) is preferably from 3 to 100, more preferably from 3 to 50, per molecule. R ^f1 as the C ₁ -C ₆ alkyl group is preferably methyl from the viewpoint of ease of synthesis and the like. C ₁ -C ₆ fluoroalkyl ^{R f1} as a base, from the viewpoint of ease of synthesis, 3,3,3-trifluoropropyl are preferred.

  The viscosity of (B2) is preferably from 1 to 100 cP, more preferably from 1 to 50 cP. (B3) may be a single compound or a combination of plural compounds.

The number of hydrogen atoms in (B3) is preferably 3 to 100, more preferably 3 to 50 in one molecule. R ^f2 as a C ₁ -C ₆ alkyl group is preferably methyl from the viewpoint of ease of synthesis and the like. C ₁ -C ₆ fluoroalkyl ^{R f2} as the base, from the viewpoint of ease of synthesis, 3,3,3-trifluoropropyl are preferred.

The ^(B3), the ratio of _R ^d4 R f2 _{2 SiO 1/2} units and _{SiO 4/2 units,} ^R d4 ^R _f2 2 _{SiO 1/2} unit 1.5 relative to _{SiO 4/2} units 1 mole 2.2 mol is preferable, and 1.8 to 2.1 mol is more preferable. ^Typically, as _{^{[R d4 R f2 2 SiO 1/2}} ] 8 [SiO 4/2] 4 or _{^{[R d4 R f2 2 SiO 1/2}} ] 10 [SiO 4/2] 5, 3~ five _{SiO 4/2} units form a cyclic siloxane skeleton, which each _{SiO 4/2} unit two ^R d4 ^R _f2 2 _{SiO 1/2} units combined is preferably, particularly preferably, Two (CH ₃ ) ₂ HSiO _1/2 units are bonded to each SiO _4/2 unit.

  The viscosity of (B3) is preferably from 1 to 100 cP, more preferably from 1 to 50 cP. (B3) may be a single compound or a combination of plural compounds.

2-2 (2). Further linear (B): (B4) and (B5)
When further (B) is linear, for example:
(B4) at both ends is closed by the ^R _e5 3 _{SiO 1/2} units, intermediate units ^R d5 ^R e6 _{SiO 2/2} units and ^R _e7 2 _{SiO 2/2} units ^{(wherein, R d5} is a hydrogen atom And each of R ^e5 , R ^e6 and R ^e7 is independently a C ₁ -C ₆ alkyl group, a C ₁ -C ₆ fluoroalkyl group or a C ₆ -C ₂₀ aryl group) at 23 ° C. viscosity of 1～10,000CP, linear polyorganohydrogensiloxane; and (B5) at both ends is closed by the ^R d6 ^R _e8 2 _{SiO 1/2} units, intermediate units ^R d7 ^R e9 SiO _{2 / 2} units and ^R _e10 2 _{SiO 2/2} units ^{(wherein, R d6} and ^{R d7} are hydrogen ^atom, R ^{e8, R e9} and ^{R e10} are each _{independently,} C 1 -C ₆ alkyl, C ₁ A C ₆ -fluoroalkyl group or a C ₆ -C ₂₀ aryl group having a viscosity at 23 ° C. of 1 to 10,000 cP). One or more selected from the following.

In (B4), R ^e5 , R ^e6 and R ^e7 are each independently defined. That is, the three ^Re5's may be the same or different. The two ^Re7's may be the same or different. Further, three ^Re5 , one ^Re6 , and two ^Re7 may be the same or different, respectively. The same applies to independently defined groups in the present specification.

R ^d5 in (B4) is preferably from 2 to 5,000, more preferably from 3 to 5,000, even more preferably from 20 to 1,000 in one molecule.

^{Re 5} , ^{Re 6} and ^Re 7 as the C ₁ -C ₆ alkyl group in (B4) are easy to synthesize and have excellent balance between properties such as mechanical strength and fluidity before curing. A methyl group is preferred. _C 1 -C ₆ fluoroalkyl as group ^R e5 in ^{(B4), R e6} and ^{R e7} are terms of easy synthesis, 3,3,3-trifluoropropyl are preferred. The ^(B4), the ratio of R ^d5 R e6 _{SiO 2/2} units and ^R _e7 2 _{SiO 2/2} ^units, with respect to _R e7 _{2 SiO 2/2} units to 1 ^mol, R ^d5 R e6 _{SiO 2/2} Those having a unit of 0.1 to 2.0 mol are preferred, and those having a unit of 0.5 to 1.5 mol are more preferred. Therefore, as (B4), both ends are blocked with trimethylsiloxane units, the intermediate unit is composed of dimethylsiloxane units and methylhydrogensiloxane units, and the amount of methylhydrogensiloxane units is 0.1 mol per 1 mol of dimethylsiloxane units. Polymethylhydrogensiloxane having a concentration of .about.2.0 mol is preferred.

  The viscosity of (B4) is 1 to 10,000 cP, preferably 1 to 5,000 cP, and more preferably 1 to 1,000 cP. (B4) may be a single compound or a combination of plural compounds.

The total of R ^d6 and R ^d7 in (B5) is preferably 2 to 5,000, more preferably 3 to 5,000, and still more preferably 3 to 1,000 in one molecule. It is.

^{R e8, R e9} and ^{R e10} as _C 1 -C ₆ alkyl group in (B5) are synthesized readily from the viewpoint of excellent balance of properties such as mechanical strength and uncured fluidity, A methyl group is preferred. As _C 1 -C ₆ fluoroalkyl group in (B5) The ^{R e7, R e8} and ^{R e9,} from the viewpoint of easy synthesis, 3,3,3-trifluoropropyl are preferred.

The ^(B5), the ratio of R ^d7 R e9 _{SiO 2/2} units and ^R _e10 2 _{SiO 2/2} ^units, with respect to _R e10 _{2 SiO 2/2} units to 1 ^mole, R ^d7 R e9 _{SiO 2/2} Those having a unit of 0.01 to 2.0 mol are preferable, and 0.05 to 1.5 mol are more preferable. Therefore, as (B5), both terminals are blocked with a dimethylhydrogensiloxane unit, and the intermediate unit is composed of a 3,3,3-trifluoropropylmethylsiloxane unit and a methylhydrogensiloxane unit. Polymethyl hydrogen siloxane in which methyl hydrogen siloxane unit is 0.01 to 2.0 mol per 1 mol of fluoropropyl methyl siloxane unit is preferable. When the composition contains (B1) and (B5) as (B), a cured product having excellent transparency tends to be obtained.

  The viscosity of (B5) is 1 to 10,000 cP, preferably 1 to 5,000 cP, more preferably 1 to 1,000 cP. (B5) may be a single compound or a combination of plural compounds.

2-2 (3). Branched (B): (B6) and (B7)
If further (B) is branched, for example:
^(B6) in ^R _d8 ^R f3 _{2 SiO 1/2} units ^{(wherein, R d8} is a hydrogen ^{atom, R f3} is independently hydrogen _atom, C 1 -C _{6 alkyl,} C 1 -C ₆ (A fluoroalkyl group or a C ₆ -C ₂₀ aryl group) and SiO _4/2 units, and a branched polyorganohydrogensiloxane having three or more hydrogen atoms bonded to a silicon atom in one molecule; and ^B7) _R f4 _{3 SiO 1/2} ^units, R f5 _{SiO 3/2} units, and, ^R _f6 2 _{SiO 2/2} units (wherein ^optionally, R ^{f4, R f5} and ^{R f6} are each independently, A hydrogen atom, a C ₁ -C ₆ alkyl group, a C ₁ -C ₆ fluoroalkyl group or a C ₆ -C ₂₀ aryl group), and has two or more hydrogen atoms bonded to a silicon atom in one molecule. Branched One or more selected from the group consisting of Li organohydrogen siloxanes.

As R ^f3 in (B6), a methyl group is preferable in terms of easy synthesis. Therefore, (B6) is composed of a dimethyl hydrogen siloxane unit and a SiO _4/2 unit, and the dimethyl hydrogen siloxane unit is 0.5 to 4 mol per 1 mol of the SiO _4/2 unit; More preferred is ~ 3 moles of polymethylhydrogensiloxane.

  The viscosity of (B6) is from 1 to 10,000 cP, preferably from 1 to 5,000 cP, more preferably from 1 to 1,000 cP. (B6) may be a single compound or a combination of plural compounds.

The ^R _f4 3 _{SiO 1/2} units in (B7), from the viewpoint of easy synthesis, dimethyl hydrogen siloxane units are preferred. Further, as R ^f5 , a C ₆ -C ₂₀ aryl group (particularly, a phenyl group) is preferable in terms of easy synthesis.

  The viscosity of (B7) is 1 to 10,000 cP, preferably 1 to 5,000 cP, more preferably 1 to 1,000 cP. (B7) may be a single compound or a combination of plural compounds.

  (B) includes (B1) alone; a combination of (B1) and (B2); a combination of (B1) and (B3); a combination of (B1) and (B5); and a combination of (B1) and (B7). Is preferred.

Of the cyclic further (B) and the linear further (B), the cyclic further (B) is preferred. The cyclic further (B) tends to give a cured product having a smaller rate of change in flexibility after the heat treatment than the linear further (B). Further, the cyclic further (B) tends to obtain a cured product having higher flexibility than the linear further (B).
Of the further cyclic (B) and the further branched (B), the further cyclic (B) is preferred. The cyclic further (B) cures faster than the branched further (B), and a cured product having excellent transparency tends to be obtained.
Of (B2) and (B3), which are cyclic further (B), (B2) is preferred. In the case of (B2), a cured product having a smaller rate of change in flexibility after heat treatment tends to be obtained as compared with the case of (B3). Further, (B2) tends to obtain a cured product having higher flexibility than (B3).

To the total number Vi _A of bonded alkenyl groups to silicon atoms (A), the ratio between the total number H _B of the hydrogen atoms bonded to silicon atoms in _{(B) (H B / Vi} A), 0. 80 or less, more preferably less than 0.75, further preferably 0.3 to 0.74, particularly preferably 0.3 to 0.72. If _(H B / Vi _A) is 0.80 greater, the cured product flexibility variation after heat treatment is large is obtained. _(H B / Vi _A) is, if it is 0.3 or more, to improve the curability, is less than 0.75, the flexibility of the variation after heat treatment is less than the cured product is obtained.

Further, the ratio (H _B1 / Vi _A ) of the total number of hydrogen atoms bonded to silicon atoms H _B1 in (B1) with respect to the total number Vi _A of alkenyl groups bonded to silicon atoms in ( _A ) is: It is not particularly limited as long as satisfying the above the _(H B / Vi _a), 0.80 or less, and more preferably less than 0.75, more preferably 0.3 to 0.74, 0.3 to 0. 72 is particularly preferred.

The amount of (B) in (B1) is not particularly limited as long as satisfying the above _(H B / Vi _A), the amount of hydrogen (B) of the total amount of hydrogen _{(B1) (H B1 / (} H _B )) is preferably from 0.1 to 1, more preferably from 0.2 to 1, and particularly preferably from 0.5 to 1. When H _B1 / (H _B ) is 0.1 or more, the effect of (B1) is more exerted, and a cured product having a smaller change rate of flexibility after heat treatment can be obtained.

3. (C) Platinum catalyst (C) is a catalyst for accelerating the addition reaction between the alkenyl group of (A) and the Si-H group of (B). From the viewpoint of good catalytic activity, compounds of platinum-based metals (platinum group elements) such as platinum, rhodium and palladium are preferably used, and chloroplatinic acid, a reaction product of chloroplatinic acid and an alcohol, a platinum-olefin complex Platinum compounds such as platinum-vinylsiloxane complexes, platinum-ketone complexes, platinum-phosphine complexes, rhodium compounds such as rhodium-phosphine complexes and rhodium-sulfide complexes, and palladium compounds such as palladium-phosphine complexes are preferable. Compounds are more preferred, and platinum-vinylsiloxane complexes are even more preferred.

  The content of (C) is 0.5% in terms of platinum-based metal atom with respect to the total weight of (A) to (C) from the viewpoint of securing the transparency of the cured product and securing an appropriate curing speed. １，1,000 ppm, preferably 0.5-500 ppm, more preferably 0.5-200 ppm. If the amount of (C) is less than 0.5 ppm, curing is slow. When the amount of (C) is more than 1,000 ppm, the discoloration of the cured product becomes remarkable and the cured product becomes black in addition to the remarkable decrease in the transparency.

4. The additive composition is selected from the group consisting of (D) a stabilizer having a nitrogen atom, (E) a diluent, (F) an adhesion-imparting agent, and (G) an inorganic filler as long as the effects of the present invention are not impaired. It may include one or more additives selected. Preferably, the composition does not contain the component (G). Further, it is preferable that the composition does not contain an inhibitor for the platinum catalyst (H).

The composition may include (D) a stabilizer having a nitrogen atom. (D) can stabilize the (C) platinum-based catalyst. As (D), for example, a general formula: (R ¹ ) ₂ N—R ³ —N (R ² ) ₂ (wherein R ¹ is each independently a C ₁ -C ₆ alkyl group (for example, Methyl, ethyl, propyl, butyl, pentyl, hexyl), R ² has the same meaning as R ¹ or is a hydrogen atom, and R ³ is a C ₂ -C ₄ alkylene group (eg, ethylene, Trimethylene, tetramethylene).).

  As (D), specifically, N, N, N ', N'-tetramethylethylenediamine, N, N-dimethylethylenediamine, N, N-diethylethylenediamine, N, N-dibutylethylenediamine, N, N-dibutyl -1,3-propanediamine, N, N-dimethyl-1,3-propanediamine, N, N, N ′, N′-tetraethylethylenediamine, N, N-dibutyl-1,4-butanediamine, N, N, N ', N'-tetramethylethylenediamine is preferred. (D) can be used alone or in combination of two or more.

  The compounding amount of (D) is preferably from 0.001 to 0.5 mol, more preferably from 0.01 to 0.1 mol, per 1 mol of the platinum-based metal atom in (C). Within such a range, it is possible to prevent the appearance of the resulting catalyst from deteriorating over time, suppress discoloration, and achieve curing in a desired time without extremely lowering the catalytic activity of (C). .

  The composition may include (E) a diluent. When the composition contains (E), the viscosity is adjusted. (E) is a silicone oil that does not contain an alkenyl group involved in the curing reaction, and is preferably a polymethylsiloxane in which both ends are blocked with a trimethylsiloxane unit and an intermediate unit is a dimethylsiloxane unit. (E) has a viscosity at 23 ° C. of preferably 1 to 5,000 cP, more preferably 5 to 1,000 cP. The blending amount of (E) is preferably 50 parts by weight or less, more preferably 30 parts by weight or less, and more preferably 20 parts by weight, based on 100 parts by weight of the total of (A) to (C) in the composition. Parts or less is more preferable.

  The composition may include (F) an adhesion-imparting agent. (F) As an adhesion-imparting agent, di, tri, tetra, and the like such as tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, tetrabutoxysilane, methyltrimethoxysilane, dimethyldimethoxysilane, methyltriethoxysilane, and dimethyldiethoxysilane Alkoxysilanes; such as 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropyl (methyl) dimethoxysilane, and 3-glycidoxypropyl (methyl) diethoxysilane 3-glycidoxypropyl group-containing alkoxysilanes; 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltriethoxysilane, 2- (3,4- Epoxy cyclohe 2- (3,4-epoxycyclohexyl) ethyl-containing alkoxysilanes such as sil) ethyl (methyl) dimethoxysilane; vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris (2-methoxyethoxy) silane, methylvinyldimethoxy Alkenylalkoxysilanes such as silane, allyltrimethoxysilane, allyltriethoxysilane, methylallyldimethoxysilane; 3-acryloxypropyltrimethoxysilane, 3-acryloxypropyltriethoxysilane, 3-acryloxypropyl (methyl) (Meth) acrylates such as dimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropyltriethoxysilane, and 3-methacryloxypropyl (methyl) dimethoxysilane B propyl alkoxysilanes; 1,1,3,5,7- organosilicon compounds such as reaction products of pentamethyl cyclotetrasiloxane and 3-methacryloxypropyl trimethoxy silane.

（式中、Ｑ^１及びＱ^２は、互いに独立して、アルキレン基、好ましくはＣ_１−Ｃ_４アルキレン基を表し、Ｒ^３は、Ｃ_１−Ｃ_４アルキル基を表す）で示される側鎖を有する有機ケイ素化合物が挙げられる。 As the organosilicon compound, for example, specifically, the following formula:

(Wherein Q ¹ and Q ² independently represent an alkylene group, preferably a C ₁ -C ₄ alkylene group, and R ³ represents a C ₁ -C ₄ alkyl group) And an organosilicon compound having the formula:

As such organosilicon compounds, the following compounds are preferred.

(H) inhibitor of the platinum catalyst, acetylenic silane, 3-hydroxy-1-propenyl _{(OH-C (CH 3)} 2 -CH = CH-) olefinic siloxanes and vinyl organosiloxanes having group. Such platinum catalyst inhibitors are described in JP-A-52-47053.

  The composition can be obtained by blending (A) to (C) and optional components. In preparation, a mixture containing (A) and (C) is prepared from the viewpoint that the composition can easily be made uniform and a transparent cured product can be obtained, and (A) and (B) It is preferable to prepare a mixture containing, and mix these to obtain a uniform composition. Optional components can be added as appropriate.

  The composition can be cured by heating. The heating temperature can be, for example, 50 to 80 ° C, preferably 60 to 70 ° C. The heating time can be, for example, 0.5 to 10 hours, preferably 0.5 to 2 hours.

  The composition can be used as a sealant for an image display device comprising the composition. The sealant for the image display device is interposed between the image display unit and the protection unit, and is cured by heating to seal the image display unit and the protection unit.

  The composition can be suitably used in an image display device, and is particularly preferable as a resin interposed between a protective portion and an image display portion of a flat panel type image display device. Therefore, the present invention relates to an image display device using the composition. Specifically, the method includes a step of applying the composition on a protective panel constituting a transparent protective portion formed of an optical plastic or the like, thereafter bonding an image display panel constituting an image display portion, and heating. The present invention relates to an image display device manufactured by a method for manufacturing an image display device.

  The compositions shown in Tables 1 to 6 were mixed with each other to prepare compositions comprising (A) and (B) of Examples and Comparative Examples. In Tables 1 to 6, “MIX” means an amount relative to the sum of “(A)” and “(B)”.

The components used are as follows. Here, the symbols mean the following.
^MH : H (CH ₃ ) ₂ SiO _{1/2
^{M V: CH 2 = CH 2}} (CH 3) 2 SiO 1/2
D: (CH ₃ ) ₂ SiO _2/2
^DH : H (CH ₃ ) SiO _2/2
D ^F : CF ₃ CH ₂ CH ₂ (CH ₃ ) SiO _2/2
T ^Ph : C ₆ H ₅ SiO _3/2
Q: SiO _4/2 (tetrafunctional)
(1) (A) Component a1: both ends are closed by M ^V unit, an intermediate unit consists of D units and D ^F unit, containing two or more alkenyl groups and one or more fluorine-containing groups in the molecule Polyorganosiloxane (viscosity at 23 ° C, 17,000 cP)
(2) (B) component (2-1) (B1) Component ^b1-1: (380cP viscosity at _{^{23 ℃) M H D F 15}} M H
_{^{b1-2: M H D F 8 M}} H ( viscosity at 23 ° C. 70 cP)
(2-2) further component (B) b2: average unit formula ^D _{H 3} D cyclics (hydrogen content 1.18 wt%) (viscosity at 23 ° C. 4 cP)
b3: cyclic substance having an average unit formula of ^MH ₈ Q ₄ (hydrogen content 1.05% by weight) (viscosity at 23 ° C. ₂₀ cP) b5: ^{MH DF} ₂₀ ^DH ₂ ^MH (viscosity at 23 ° C. 600 cP) ) Linear product b7: a branched product b ′ having an average unit formula of ^MH ₃ T ^Ph (hydrogen content 0.94% by weight) (viscosity 6 cP at 23 ° C.): both ends blocked with ^MH units , A linear polymethylhydrogensiloxane having an intermediate unit composed of D units (viscosity at 23 ° C of 20 cP)
(3) (c) Component c1: Obtained by heating chloroplatinic acid to 1,3-divinyl-1,1,3,3-tetramethyldisiloxane at a molar ratio of 1: 4 and having a platinum content of 5 A complex that is 0.0% by weight.

<Examples 1 to 14, Comparative Examples 1 to 7>
Evaluation of physical properties was performed as follows.
(1) Viscosity The viscosity at 23 ° C. was measured using a rotational viscometer (Vismetron VDA-L) (manufactured by Shibaura System Co., Ltd.).
(2) Tack free time The composition of (A) and the composition of (B) are extruded at a volume ratio of 1: 1 and 5 g is taken out on a flat plate while being mixed with a mixing nozzle, and the two liquids come into contact with each other. The time taken was 0, and the surface was lightly touched with a fingertip cleaned with ethyl alcohol, and the time until the sample did not adhere to the fingertip was regarded as tack-free. This measurement method conforms to the tack-free time measurement in JIS-K6249.
(3) Yellow index (YI)
Two glass plates (5 cm × 5 cm × 1 mm thick) were used as substrates. The thickness of the composition was adjusted to 200 μm by a spacer previously arranged on the substrate. Two glass plates were bonded via the composition so that the dimensions of the composition were 50 mm × 50 mm and the thickness was 200 μm, to obtain a bonded body. The bonded body was subjected to a heat treatment at 25 ° C. for 30 minutes and at 70 ° C. for 30 minutes to obtain a bonded body in which two substrates were bonded via a cured product of the composition. After returning the bonded body to a temperature of 25 ° C., a yellow index as an index of the degree of discoloration was measured. The yellow index was measured using a spectrophotometer (CM-3500d, manufactured by Minolta Co., Ltd.).
(4) Haze
A sample was prepared in the same manner as in "(3) Yellow Index". The haze of the prepared sample was measured using a haze meter NDH5000 (manufactured by Nippon Denshoku Industries Co., Ltd.) in accordance with JIS K 7105.
(5) Penetration A 40 ml uncured silicone gel composition was placed in a heat-resistant glass beaker having a capacity of 100 ml, and heated at 60 ° C. for 30 minutes to cure, thereby obtaining a silicone gel. After cooling to room temperature, the penetration was measured using a 1/4 cone according to JIS K6249. Further, 40 ml of the uncured silicone gel composition was placed in a heat-resistant glass beaker having a capacity of 100 ml, and cured by heating at 60 ° C. for 30 minutes to obtain a silicone gel before heat treatment. Next, by performing a heat treatment at 150 ° C. for 1 hour, a silicone gel after the heat treatment was obtained. After cooling to room temperature, the penetration was measured using a 1/4 cone according to JIS K6249. The penetration change rate by the heat treatment was determined by the following equation (1). A small rate of change in penetration means that the rate of change in flexibility of the cured product after the heat treatment is small.
Penetration change rate = (Penetration before heat treatment (1)-Penetration after heat treatment (2)) ÷ Penetration before heat treatment (1) ... Equation (1)
(6) Refractive index The refractive index was measured according to JIS K0062.
(7) b * (D65)
A sample was prepared in the same manner as in "(3) Yellow Index". About the produced sample, b * (D65) was measured.

The results are shown in Tables 1 to 6.

The rate of change in penetration of the cured products obtained in Examples 1 to 14 was small, and the rate of change in flexibility of the cured product after the heat treatment was small.
Comparison of Example 1 with Example 6 shows that Example 6 using the cyclic additional (B) is more flexible after the heat treatment than Example 1 using the linear additional (B). A cured product having a lower rate of change in properties and a higher flexibility was obtained.
Comparison of Example 11 with Example 12 shows that Example 11 with the additional ring (B) cures faster and is more transparent than Example 12 with the additional ring (B). A cured product having excellent properties was obtained.
By comparing Example 11 and Example 13, Example 11 using (B2) has a smaller rate of change in flexibility after heat treatment and more flexibility than Example 13 using (B3). A highly cured product was obtained.

Comparative Example _1, since the H B / Vi _A ratio exceeds 0.80, penetration rate of change of the cured product obtained in Comparative Example 1 were large. The same applies to Comparative Examples 2 to 4.
Comparative Examples 5 to 7 have hydrogen at both ends and do not have a linear chain extender having a fluorine-containing group.
Comparative Example 5 uses only b ′ which is a linear polyorganohydrogensiloxane having no C ₁ -C ₆ fluoroalkyl group as (B). b ′ did not mix with (A), and a uniform composition could not be obtained.
Comparative Example 6 uses a combination of b ′ and b3 that is compatible with a1 as (B). However, b ′ did not mix with (A), and a uniform composition could not be obtained as a whole.
In Comparative Example 7, since only b5 having hydrogen as an intermediate unit was used as (B), Comparative Example 7 had a high penetration change rate of the cured product after the heat treatment.

  Curing of the curable polyorganosiloxane composition, even in the case of heat treatment, has a small rate of change in flexibility. Can be secured. Therefore, the curable polyorganosiloxane composition is useful for bonding various substrates, particularly for bonding a base having an image display portion of an image display device such as a cathode ray tube, a liquid crystal, a plasma, and an organic EL to a light-transmitting protective portion. It is.

Claims (7)

(A) an alkenyl group-containing polyorganosiloxane having a viscosity at 23 ° C. of 1 to 100,000 cP and containing two or more alkenyl groups and one or more fluorine-containing groups in a molecule;
(B) A polyorganohydrogensiloxane having two or more hydrogen atoms bonded to a silicon atom in a molecule, wherein (B) is a compound represented by the following formula (B1):

(Where
R ^d1 is a hydrogen atom,
R ^e2 is independently a C ₁ -C ₆ fluoroalkyl group, a C ₁ -C ₆ alkyl group or a C ₆ -C ₂₀ aryl group, and at least one ^{Re 2} is a C ₁ -C ₆ fluoroalkyl group. And
m3 is a number having a viscosity of 1 to 10,000 cP at 23 ° C.), including a polyorganohydrogensiloxane including a linear polyorganohydrogensiloxane; and (C) a platinum-based catalyst,
To the number Vi _A alkenyl group (A), or less the ratio of the number _{H B} of hydrogen atoms bonded to silicon atoms is 0.80 (B),
(C) is 0.5 to 1,000 ppm as a platinum-based metal atom;
A curable polyorganosiloxane composition. (B) is, ^{(B2 -1)} in R d3 R f1 _{SiO 2/2} units ^{(wherein, R d3} is a hydrogen ^{atom, R f1} is hydrogen _atom, C 1 -C ₆ alkyl, _{C 1} - C ₆ fluoroalkyl group or a _C 6 _{-C 20} aryl group) or Rannahli, in one molecule, the hydrogen atoms bonded to silicon atoms has 2 or more, a viscosity at 23 ° C. is at 1~10,000cP Certain cyclic polyorganohydrogensiloxanes ;
(B2-2) R ^d3 R ^f1 SiO _2/2 unit (where R ^d3 is a hydrogen atom, and R ^f1 is a hydrogen atom, a C ₁ -C ₆ alkyl group, a C ₁ -C ₆ fluoroalkyl group) or _C 6 _{-C 20} aryl group) and ^R _e4 2 _{SiO 2/2} units ^{(wherein, R e4} are _{independently,} C 1 -C _{6 alkyl,} C 1 -C ₆ fluoroalkyl group or a C consists ₆ -C ₂₀ aryl group), in one molecule, the hydrogen atoms bonded to silicon atoms has 2 or more, a viscosity at 23 ° C. is 1～10,000CP, cyclic polyorganohydrogensiloxane ; and ^(B3) in ^R _d4 ^R f2 _{2 SiO 1/2} units ^{(wherein, R d4} is a hydrogen ^{atom, R f2} is independently a hydrogen _atom, C 1 -C ₆ alkyl, _{C 1} - C ₆ fluoroalkyl group or ₆ -C ₂₀ aryl group) and consists _{SiO 4/2} units, in a molecule, the hydrogen atoms bonded to silicon atoms has 2 or more, a viscosity at 23 ° C. is 1～10,000CP, The curable polyorganosiloxane composition according to claim 1, comprising one or more selected from the group consisting of cyclic polyorganohydrogensiloxanes. (B) is, (B4) both terminals blocked with ^R _e5 3 _{SiO 1/2} units, intermediate units ^R d5 ^R e6 _{SiO 2/2} units and ^R _e7 2 _{SiO 2/2} units ^{(wherein, R d5} is hydrogen ^atom, R ^{e5, R e6} and ^{R e7} are from _{independently,} C 1 -C ₆ alkyl _group, a C 1 -C ₆ fluoroalkyl group or a _C 6 _{-C 20} aryl group) becomes, a viscosity at 23 ° C. is 1～10,000CP, linear polyorganohydrogensiloxane; and (B5) at both ends is closed by the ^R d6 ^R _e8 2 _{SiO 1/2} units, intermediate units ^{R d7} R ^e9 SiO _2/2 units and ^R _e10 in 2 _{SiO 2/2} units ^{(wherein, R d6} and ^{R d7} are hydrogen ^atom, R ^{e8, R e9} and ^{R e10} are each independently, _{C 1} - C ₆ alkylene Group _consist C 1 -C ₆ fluoroalkyl group or a _C 6 _{-C 20} aryl group), a viscosity of several to 1～10,000CP) at 23 ° C., linear polyorganohydrogen The curable polyorganosiloxane composition according to claim 1, comprising one or more selected from the group consisting of siloxanes. (B) _{^{is, (B6) R d8 R f3}} 2 SiO 1/2 units ^{(wherein, R d8} is a hydrogen ^{atom, R f3} is independently hydrogen _atom, C 1 -C ₆ alkyl, A C ₁ -C ₆ fluoroalkyl group or a C ₆ -C ₂₀ aryl group) and SiO _4/2 units, and in one molecule, a branched polyorganohydro having at least three hydrogen atoms bonded to silicon atoms in one molecule. Gensiloxane ;
_{^{(B7 -1) R f4 3 SiO}} 1/2 units and R ^f5 SiO _3/2 Unit ^{(wherein, R f4} and R ^{f 5} are each independently a hydrogen _atom, C 1 -C ₆ alkyl, C ₁ -C consists ₆ represents a fluoroalkyl group or a C ₆ -C ₂₀ aryl group), in one molecule, branched polyorganohydrogensiloxane having a hydrogen atom bonded to a silicon atom at least two, and
_^(B7-2) R f4 _{3 SiO 1/2} ^units, R f5 _{SiO 3/2} units, ^and, _R f6 _{2 SiO 2/2} units ^(wherein, R ^{f4, R f5} and ^{R f6} are each independently a hydrogen _atom, consist C 1 -C ₆ alkyl _group, a C 1 -C ₆ fluoroalkyl group or a _C 6 _{-C 20} aryl group), in one molecule, the hydrogen atoms bonded to silicon atoms 2 or more branched polyorganohydrogen containing one or more selected from the group consisting of siloxanes, curable polyorganosiloxane composition according to claim 1 having. (A) is represented by the formula (a3):

(Where
R ^a2 is independently a C ₂ -C ₆ alkenyl group;
R ^b3 is independently a C ₁ -C ₆ fluoroalkyl group,
R ^c3 is independently a C ₁ -C ₆ alkyl group or a C ₆ -C ₂₀ aryl group;
R ^e1 is independently a C ₁ -C ₆ fluoroalkyl group, a C ₁ -C ₆ alkyl group or a C ₆ -C ₂₀ aryl group;
m1 + m2 is a value at which the viscosity at 23 ° C. is 1 or more and less than 100,000 cP)
The curable polyorganosiloxane composition according to any one of claims 1 to 4, which is an alkenyl group-containing polyorganosiloxane represented by the following formula: Number (H) of hydrogen atoms bonded to silicon atoms in (B) _B Of hydrogen atoms bonded to silicon atoms in (B1) _B1 Ratio (H _B1 / H _B ) Is 0.1 to 1, and the curable polyorganosiloxane composition according to any one of claims 1 to 5. The image display apparatus for sealant comprising a curable polyorganosiloxane composition according to any one of claims 1-6.