JP5825738B2 - Silicone pressure-sensitive adhesive composition, laminate and silicone pressure-sensitive adhesive tape - Google Patents

Description

The present invention relates to a silicone-based pressure-sensitive adhesive composition, a laminate, and a silicone pressure-sensitive adhesive tape. Specifically, a silicone-based pressure-sensitive adhesive composition having good adhesion to a sheet-like substrate such as a plastic film, and a cured product of the silicone-based pressure-sensitive adhesive composition are laminated on the sheet-like substrate. The present invention relates to a silicone pressure-sensitive adhesive tape obtained by laminating a cured product of a silicone-based pressure-sensitive adhesive composition on a laminate and a plastic film tape.

The silicone-based pressure-sensitive adhesive composition has characteristics that it is excellent in electrical insulation, heat resistance, cold resistance, and adhesiveness to various adherends as compared with an acrylic or rubber-based pressure-sensitive adhesive composition. For this reason, it is used in the manufacture of heat-resistant tapes, electrical insulating tapes, heat seal tapes, plating masking tapes and the like. These silicone-based pressure-sensitive adhesive compositions are classified into an addition reaction curing type, a condensation reaction curing type, and a peroxide curing type depending on the curing mechanism. Addition reaction curable, that is, hydrosilylation reaction curable silicone-based pressure-sensitive adhesive compositions have been widely used in recent years because they have a rapid curing rate upon heating and no by-products are generated. Such a hydrosilylation reaction-curable silicone-based pressure-sensitive adhesive composition is disclosed in, for example, Japanese Patent Publication No. 6-84494 (Patent Document 1).

In recent years, hydrosilylation reaction-curable silicone-based pressure-sensitive adhesive compositions that have no adhesive residue on the adherend when it is applied to an adherend such as metal and then peeled off after high temperature exposure have attracted attention. JP-A-2005-298550 (Patent Document 2), JP-A-2006-213810 (Patent Document 3), JP-A-2008-156497 (Patent Document 4), JP-A-2009-51916 (Patent Document) 5). However, these silicone-based pressure-sensitive adhesive compositions and pressure-sensitive adhesive silicone compositions often have insufficient adhesion to the plastic film as the sheet-like substrate, and the plastic film is preliminarily treated with a primer. Often necessary.

（式中、Ｒは一価炭化水素基、R¹は低級アルケニル基であり、ｎは整数である。）で示されるジオルガノポリシロキサン ３０〜７０重量部、
（Ｂ）R² ₃SiO_1/2単位（式中、R²はアルキル基、アルケニル基および水酸基から選択され、全R²基の少なくとも９５モル％はメチル基である。）とSiO₂単位から成りそのモル比が（0.6:1）〜（0.9:1）の範囲内にあり、ケイ素原子結合水酸基含有量が０〜１重量％の範囲内にある、オルガノポリシロキサン ７０〜３０重量部、
（Ｃ）１分子中に少なくとも２個のケイ素原子結合水素原子を有するオルガノハイドロジェンポリシロキサン（Ａ）成分中のアルケニル基１個あたり、１〜４０個のケイ素原子結合水素原子を与えるに充分な量および（Ｄ）白金系触媒（Ａ）〜（Ｃ）成分の合計量１００万重量部に対して白金金属として０.１〜１０００重量部から成る。
実施例と比較例では、成分（Ｃ）として粘度10センチポイズの両末端トリメチルシロキシ基封鎖ジメチルシロキサン・メチルハイドロジェンシロキサン共重合体（ケイ素原子結合水素原子とケイ素原子結合メチル基のモル比１:３）のみが使用されており、シート状基材であるプラスチックフィルムへの密着性が十分とは言えない。 The solvent-free silicone pressure-sensitive adhesive composition disclosed in JP-B-6-84494 (Patent Document 1)
(A) General formula

(Wherein R is a monovalent hydrocarbon group, R ¹ is a lower alkenyl group, and n is an integer) 30 to 70 parts by weight of a diorganopolysiloxane
(B) From R ² ₃ SiO _1/2 unit (wherein R ² is selected from an alkyl group, an alkenyl group and a hydroxyl group, and at least 95 mol% of all R ² groups are methyl groups) and SiO ₂ unit 70 to 30 parts by weight of an organopolysiloxane having a molar ratio of (0.6: 1) to (0.9: 1) and a silicon atom-bonded hydroxyl group content of 0 to 1% by weight,
(C) Sufficient to give 1 to 40 silicon-bonded hydrogen atoms per alkenyl group in the organohydrogenpolysiloxane (A) component having at least two silicon-bonded hydrogen atoms in one molecule It consists of 0.1 to 1000 parts by weight as platinum metal with respect to the amount and (D) 1 million parts by weight of the total amount of the platinum-based catalyst (A) to (C).
In Examples and Comparative Examples, as component (C), a trimethylsiloxy group-blocked dimethylsiloxane / methylhydrogensiloxane copolymer having a viscosity of 10 centipoise (a molar ratio of silicon atom-bonded hydrogen atoms to silicon atom-bonded methyl groups is 1: 3). ) Is used, and it cannot be said that the adhesiveness to the plastic film as the sheet-like substrate is sufficient.

The silicone composition for pressure-sensitive adhesives disclosed in JP-A-2005-298550 (Patent Document 2)
(A) 20 to 95 parts by mass of a polyorganosiloxane having at least two alkenyl groups in one molecule and having an alkenyl group content of 0.0015 to 0.06 mol / 100 g,
(B) a polyorganosiloxane containing R ¹ ₃ SiO _0.5 units and SiO ₂ units, wherein the ratio of the number of moles of R ¹ ₃ SiO _0.5 units to the number of moles of SiO ₂ units is 0.6 to 1.7 (provided that R ¹ May be different from each other, 80 to 5 parts by mass of a monovalent hydrocarbon group having 1 to 10 carbon atoms),
(C) A polyorganosiloxane containing 3 or more SiH groups in one molecule has a ratio of the number of moles of SiH groups in the component (C) to the number of moles of alkenyl groups in the component (A) of 0.5 to 20. The amount of
(D) 0 to 8.0 parts by mass of the control agent with respect to 100 parts by mass in total of (A) and (B), and
(E) The platinum catalyst is characterized by containing 1 to 5000 ppm as a platinum content with respect to 100 parts by mass in total of (A) and (B).
As the component (C), methylhydrogenpolysiloxane represented by the formula Me ₃ SiO— [MeHSiO] ₄₅ — [Me ₂ SiO] ₁₇ —SiMe ₃ is used in the examples, and in the comparative example, the formula Me ₃ SiO— Methyl hydrogen polysiloxane represented by [MeHSiO] ₄₀ -SiMe ₃ is used, and it cannot be said that the adhesiveness to the plastic film as the sheet-like substrate is sufficient.

The silicone composition for pressure-sensitive adhesives disclosed in JP-A-2006-213810 (Patent Document 3)
(A) a mixture obtained by reacting a polyorganosiloxane having at least two alkenyl groups in one molecule with (B) a polyorganosiloxane having R ¹ ₃ SiO _0.5 units and SiO ₂ units, (C) SiH It consists of a polyorganosiloxane having a group, (D) a control agent, and (E) a platinum-based catalyst, and there is a problem that it takes time to produce the reaction mixture. In the example, only Me ₃ SiO— [MeHSiO] ₄₅ — [Me ₂ SiO] ₁₇ —SiMe ₃ is used as the component (C), and Me ₃ SiO— [MeHSiO] ₄₀ —SiMe ₃ is used in the comparative example. Therefore, it cannot be said that the adhesiveness to the plastic film as the sheet-like substrate is sufficient.

The silicone-based pressure-sensitive adhesive composition disclosed in JP-A-2008-156497 (A): (A): (a) a silanol group at both ends of a molecular chain and two or more silicon atom-bonded alkenyls at a side chain A diorganopolysiloxane having a high degree of polymerization having a group and (b) an organopolysiloxane resin having at least one hydrolyzable group in one molecule and consisting essentially of M units and Q units. (B): organohydrogenpolysiloxane (C): diorganopolysiloxane having a high degree of polymerization having silicon-bonded alkenyl groups at both ends of the molecular chain, (D): M Organopolysiloxane resin consisting essentially of units and Q units and (E): a platinum-based catalyst, and there is a problem that the production of component (A) is not easy.
In Examples and Comparative Examples, the average structural formula Me ₃ SiO (Me ₂ SiO) ₂₄ (MeHSiO) ₅₀ SiMe ₃ is used as the component (B).
Only a methylhydrogen / dimethylsiloxane copolymer having both ends of a molecular chain with a viscosity of 55 mPa · s blocked with a trimethylsiloxy group is used, and the adhesiveness to a plastic film as a sheet-like substrate is sufficient. I can't say that.

The silicone-based pressure-sensitive adhesive composition disclosed in JP-A-2009-51916 (Patent Document 5)
(A) Molecular formula: (R ₃ SiO _1/2 ) _4-p (R ¹ R ₂ SiO _1/2 ) _p (R ₂ SiO) _m (RR ¹ SiO) _n (SiO _4/2 )
(R is a monovalent hydrocarbon group, R ¹ is an alkenyl group, p is an average of 2 to 4, m is 1500 to 10,000, n is 0 or more, m> n, m + n is 1500 to 10,000), Branched organopolysiloxane having an average of at least two alkenyl groups in: 100 parts, (B) R ³ R ² ₂ SiO _1/2 unit (R ² is an alkyl group, R ³ is an alkyl group, an alkenyl group, Aryl group or hydroxyl group) and SiO _4/2 units, and the molar ratio is 0.6 to 1.7, the organopolysiloxane resin is 10 to 400 parts, (C) the organohydrogenpolysiloxane is the molar ratio of HSi to the alkenyl group. Is an amount of 1.0 to 60, and (D) a platinum-based catalyst: a catalyst amount, and the branched organopolysiloxane is not easy to produce. In the examples and comparative examples, as the component (C), a methylhydrogensiloxane / dimethylsiloxane copolymer (silicon atom-bonded hydrogen) having a viscosity of 100 cSt (about 100 mPa · s) and having both molecular chain ends blocked with trimethylsiloxy groups. Only an atomic content of 1.0% by weight) is used, and it cannot be said that the adhesion to a plastic film as a sheet-like substrate is sufficient.

Japanese Patent Publication No. 6-84494 JP 2005-298550 A JP 2006-213810 A JP 2008-156497 A JP 2009-51916 A

Therefore, the present inventors have _prepared an organopolysiloxane resin comprising R ₃ SiO _1/2 units (R is an unsubstituted or substituted monovalent hydrocarbon group having 1 to 10 carbon atoms) and SiO _4/2 units and 1 A linear diorganopolysiloxane having at least two alkenyl groups in the molecule as a main agent, a linear or branched organohydrogenpolysiloxane as a crosslinking agent, and a sheet-like substrate such as a plastic film, particularly Has intensively studied to develop a hydrosilylation reaction-curable silicone-based pressure-sensitive adhesive composition having good adhesion to a heat-resistant plastic film substrate, and as a result, the present invention has been achieved.

That is, the present invention is based on the above-mentioned organopolysiloxane resin and a linear diorganopolysiloxane having at least two alkenyl groups in one molecule, and a linear or branched organohydrogenpolysiloxane. Hydrosilylation reaction curable silicone-based pressure-sensitive adhesive composition and hydrosilylation reaction curable silicone having good adhesion to a sheet-like substrate such as a plastic film, particularly a heat-resistant plastic film substrate, as a crosslinking agent Laminates in which pressure sensitive adhesives are well adhered to sheet-like substrates such as plastic films, particularly heat resistant plastic film substrates, and hydrosilylation reaction curable silicone pressure sensitive adhesives are plastic film tapes , Especially good for heat-resistant plastic film tape And to provide an adhesive tape which are in close contact.

As a result of intensive studies, the present inventors have found that the above problems can be solved by a hydrosilylation reaction curable silicone-based pressure-sensitive adhesive composition comprising the following components (A) to (D): The present invention has been reached.
(A) (a) R ₃ SiO _1/2 unit (wherein R is an unsubstituted monovalent hydrocarbon group or substituted monovalent hydrocarbon group having 1 to 10 carbon atoms) and (b) SiO _{4 /} Organopolysiloxane resin consisting essentially of ₂ units and having a molar ratio of (a) units to (b) units in the range of 0.6: 1 to 1.2: 1; 10 to 70 parts by weight;
(B) The following average structural formula (1):
R ² R ³ ₂ SiO (R ³ ₂ SiO) _p (R ³ R ⁴ SiO) _q SiR ³ ₂ R ² (1)
(In the formula, R ² is a group selected from an alkenyl group having 2 to 10 carbon atoms and a hydroxyl group, and R ³ is an unsubstituted monovalent hydrocarbon having no aliphatic unsaturated bond having 1 to 10 carbon atoms. A group or a substituted monovalent hydrocarbon group, R ⁴ is an alkenyl group having 2 to 10 carbon atoms, p is a positive number, q is a number of 0 or more, and satisfies the relationship of ( p + q) ≧ 200 Provided that when q is 1, at least one of R ² is the alkenyl group, and when q is 0, R ² is any of the alkenyl groups.) Linear diorganopolysiloxane having 2 to 10 silicon atom-bonded alkenyl groups; 30 to 90 parts by mass (the total of component (A) and component (B) is 100 parts by mass) ),
(C) The following average siloxane unit formula (2):
(R ¹ ₃ SiO _1/2 ) _k (R ¹ HSiO _2/2 ) _l (R ¹ ₂ SiO _2/2 ) _m (R ¹ SiO _3/2 ) _n (2)
(Wherein R ¹ is an unsubstituted monovalent hydrocarbon group or a substituted monovalent hydrocarbon group having no aliphatic unsaturated bond having 1 to 10 carbon atoms, k is the number of ( 2 + n) , and l Is an average number in the range of 100 to 500, m and n are average numbers of 0 or more, and 0.8 ≦ l / (k + l + m + n) ≦ 1 and 100 ≦ (k + l + m + n) ≦ 500) An amount such that the molar ratio of silicon-bonded hydrogen atoms in the component (C) to the alkenyl group in the component (B) is in the range of 1 to 100, and (D) a hydrosilylation reaction catalyst Catalyst amount

In addition, since the present inventors have good adhesion to a sheet-like substrate such as a plastic film, particularly a heat-resistant plastic film substrate, the organohydrogenpolysiloxane has the following average siloxane unit formula: (3):
(R ¹ ₃ SiO _1/2 ) _k1 (R ¹ HSiO _2/2 ) ₁₁ (R ¹ ₂ SiO _2/2 ) _m1 (R ¹ SiO _3/2 ) _n1 (3)
Wherein R ¹ is as described above, l1 is an average number in the range of 100 to 500, m1 is an average number in the range of 0 to 95, n1 is a number of 0 or 1, and k1 is n1 is 2 when 0, n1 is 3 when 1 .k1, l1, m1 and n1 satisfies 0 .8 ≦ l1 / (k1 + l1 + m1 + n1) ≦ 1 and 100 ≦ (k1 + l1 + m1 + n1) ≦ 500 relationship The present inventors have found that the above-mentioned problems can be better solved by the hydrosilylation reaction-curable silicone-based pressure-sensitive adhesive composition that is a linear or branched organohydrogenpolysiloxane represented by the following formula.

That is, the purpose is
“[1] Hydrosilylation reaction-curable silicone-based pressure-sensitive adhesive composition comprising the following components (A) to (D):
(A) (a) R ₃ SiO _1/2 unit (wherein R is an unsubstituted monovalent hydrocarbon group or substituted monovalent hydrocarbon group having 1 to 10 carbon atoms) and (b) SiO _{4 / An} organopolysiloxane resin consisting essentially of ₂ units and having a molar ratio of (a) units to (b) units in the range of 0.6: 1 to 1.2: 1; 10 to 70 parts by weight;
(B) The following average structural formula (1):
R ² R ³ ₂ SiO (R ³ ₂ SiO) _p (R ³ R ⁴ SiO) _q SiR ³ ₂ R ² (1)
(In the formula, R ² is a group selected from an alkenyl group having 2 to 10 carbon atoms and a hydroxyl group, and R ³ is an unsubstituted monovalent hydrocarbon having no aliphatic unsaturated bond having 1 to 10 carbon atoms. A group or a substituted monovalent hydrocarbon group, R ⁴ is an alkenyl group having 2 to 10 carbon atoms, p is a positive number, q is a number of 0 or more, and satisfies the relationship of ( p + q) ≧ 200 Provided that when q is 1, at least one of R ² is the alkenyl group, and when q is 0, R ² is any of the alkenyl groups.) Linear diorganopolysiloxane having 2 to 10 silicon atom-bonded alkenyl groups; 30 to 90 parts by mass (the total of component (A) and component (B) is 100 parts by mass) ),
(C) The following average siloxane unit formula (2):
(R ¹ ₃ SiO _1/2 ) _k (R ¹ HSiO _2/2 ) _l (R ¹ ₂ SiO _2/2 ) _m (R ¹ SiO _3/2 ) _n (2)
(Wherein R ¹ is an unsubstituted monovalent hydrocarbon group or a substituted monovalent hydrocarbon group having no aliphatic unsaturated bond having 1 to 10 carbon atoms, k is the number of ( 2 + n) , and l Is an average number in the range of 100 to 500, m and n are average numbers of 0 or more, and 0.8 ≦ l / (k + l + m + n) ≦ 1 and 100 ≦ (k + l + m + n) ≦ 500) (B) an amount such that the molar ratio of silicon-bonded hydrogen atoms in the component (C) to the alkenyl group in the component is in the range of 1 to 100, and (D) a hydrosilylation reaction catalyst Catalyst amount
[2] The component (C) is the following average siloxane unit formula (3):
(R ¹ ₃ SiO _1/2 ) _k1 (R ¹ HSiO _2/2 ) ₁₁ (R ¹ ₂ SiO _2/2 ) _m1 (R ¹ SiO _3/2 ) _n1 (3)
Wherein R ¹ is as described above, l1 is an average number in the range of 100 to 500, m1 is an average number in the range of 0 to 95, n1 is a number of 0 or 1, and k1 is n1 is 2 when 0, n1 is 3 when 1 .k1, l1, m1 and n1 satisfies 0 .8 ≦ l1 / (k1 + l1 + m1 + n1) ≦ 1 and 100 ≦ (k1 + l1 + m1 + n1) ≦ 500 relationship The hydrosilylation reaction curable silicone-based pressure-sensitive adhesive composition according to [1], which is a linear or branched organohydrogenpolysiloxane represented by the formula:
[3] The component (C) has the following average structural formula (4):
R ¹ ₃ SiO (R ¹ HSiO _2/2 ) _l2 (R ¹ ₂ SiO _2/2 ) _m2 SiR ¹ ₃ (4)
(Wherein R ¹ is as described above, l2 is an average number in the range of 100 to 400, m2 is an average number in the range of 0 to 95, and l2 and m2 are 100 ≦ l2 + m2 + 2 ≦ 400 and 0 The hydrosilylation reaction-curable silicone-based pressure-sensitive adhesive assembly according to claim 1, which is a linear organohydrogenpolysiloxane represented by the following relationship: .95 ≦ l2 / (l2 + m2 + 2) ≦ 1).
[4] The component (B) is represented by the above average structural formula (1), and further satisfies the relationship of ( p + q) ≧ 3000 and 0 ≦ q / (p + q) ≦ 0.05 The hydrosilylation reaction-curable silicone-based pressure-sensitive adhesive composition according to any one of [1] to [3] .
[5] A silicone-based pressure-sensitive adhesive obtained by curing the hydrosilylation reaction-curable silicone-based pressure-sensitive adhesive composition according to any one of [1] to [4] on a sheet-like substrate and the sheet-like substrate Laminate with layers.
[6] The laminate according to [5], wherein the sheet-like substrate is a heat-resistant plastic film substrate.
[7] A silicone pressure-sensitive adhesive tape comprising the laminate according to [5], wherein the sheet-like substrate is a plastic tape.
[8] The silicone adhesive tape according to [7], wherein the plastic tape is a heat-resistant plastic tape.

The silicone-based pressure-sensitive adhesive composition of the present invention has good adhesion to a sheet-like substrate such as a plastic film, particularly a heat-resistant plastic film such as a polyester film and a polyimide film.
In the laminate of the present invention, the hydrosilylation reaction curable silicone-based pressure-sensitive adhesive is in good contact with a sheet-like substrate such as a plastic film, particularly a heat-resistant plastic film substrate. In the silicone pressure-sensitive adhesive tape of the present invention, the hydrosilylation reaction-curable silicone pressure-sensitive adhesive is in good contact with a plastic film tape, particularly a heat-resistant plastic film tape.

The component (A) constituting the hydrosilylation reaction-curable silicone-based pressure-sensitive adhesive composition of the present invention has a pressure-sensitive adhesive that is a cured product of the pressure-sensitive adhesive composition and has an adhesive force to the sheet-like substrate. (A) R ₃ SiO _1/2 unit (wherein R is an unsubstituted monovalent hydrocarbon group or substituted monovalent hydrocarbon group having 1 to 10 carbon atoms) and (b) An organopolysiloxane resin consisting essentially of SiO _4/2 units and having a molar ratio of (a) units to (b) units ranging from 0.6: 1 to 1.2: 1. This organopolysiloxane resin is preferably soluble in component (B).

Examples of the unsubstituted monovalent hydrocarbon group having 1 to 10 carbon atoms as R include an alkyl group such as a methyl group, an ethyl group, a propyl group, a pentyl group, a hexyl group, and an octyl group; a cycloalkyl group such as a cyclohexyl group , Cycloheptyl group; aryl group such as phenyl group, tolyl group, xylyl group; aralkyl group such as benzyl group, α-methylstyryl group and 2-phenylethyl group; alkenyl group such as vinyl group, allyl group, propenyl group, A butenyl group, a pentenyl group, and a hexenyl group are exemplified.

Examples of the substituted monovalent hydrocarbon group having 1 to 10 carbon atoms as R include a fluorinated monovalent hydrocarbon group such as 3,3,3-trifluoropropyl group, 4,4,5,5,5- Perfluoroalkyl groups such as pentafluorobutyl, 3,3,4,4,5,5,6,6,6-nonafluorohexyl; chlorinated monovalent hydrocarbon groups such as 3-chloropropyl And a chlorophenyl group such as a dichlorophenyl group.

From the viewpoint of ease of production and compatibility with other siloxane components, the R group in the molecule of component (A) is a monovalent saturated aliphatic hydrocarbon group having 1 to 10 carbon atoms (provided that at least 50 mol% is present) It is preferably a methyl group, and among them, at least 85 mol% is preferably a methyl group, and most preferably all methyl groups. Or it consists of a methyl group and a phenyl group, and it is preferable that those at least 50 mol% is a methyl group, and it is more preferable that at least 85 mol% is a methyl group.
From the viewpoint of pressure-sensitive adhesive strength, the alkenyl group content in all R groups is preferably 0.5 mol% or less, more preferably 0 mol%.

In order to increase the solubility of component (A) in component (B), preferably at least one third of the R groups in component (A), more preferably substantially all R groups are present. An alkyl group having 1 to 10 carbon atoms, particularly a methyl group.
As siloxane units represented by the formula R ₃ SiO _1/2 , Me ₃ SiO _1/2 , Me ₂ HeSiO _1/2 , MeHePhSiO _1/2 , PhMe ₂ SiO _1/2 and Ph ₂ MeSiO _1/2 (where, Me is methyl, He is hexyl, and Ph is phenyl.).

In component (A), R ₃ SiO _1/2 unit (M unit) is bonded to SiO _4/2 unit (Q unit), and the SiO _4/2 unit is bonded to at least one other SiO _4/2 unit. doing. Some SiO _4/2 units, also to some that bound to the hydroxy group has become _{HOSiO 3/2} units ^{(T OH} units), some are bonded only to other _{SiO 4/2} units is there. In addition to the R ₃ SiO _1/2 unit (M unit) and the SiO _4/2 unit (Q unit), the component (A) is a small amount (for example, 10 mol% or less), and has a pressure-sensitive adhesive property. As long as no adverse effect is exerted, any of a siloxane unit represented by the formula R ₂ SiO _2/2 , a siloxane unit represented by the formula RSiO _3/2 , a unit in which R in these siloxane units is substituted with a hydroxyl group, or a plurality thereof May be contained.

Component (A) has a molar ratio of RSiO _1/2 units (M units) to SiO _4/2 units (Q units) of 0.6 to 1.2, preferably 0.7 to 1.0. is there. This is because when the molar ratio is less than 0.6, the pressure-sensitive adhesive force is lowered, and when it exceeds 1.2, the cohesive force is lowered. The molar ratio can be easily measured by ²⁹ Si nuclear magnetic resonance.

The component (A) may be prepared by a conventionally known method. Preferably, it is prepared by the silica hydrosol capping method of US Pat. No. 2,676,182, the method described in US Pat. No. 3,627,851 and US Pat. No. 3,772,247, which are modified versions thereof. The

The amount of silicon atom-bonded hydroxyl group in component (A) is preferably 1% by weight or less. The silicon atom-bonded hydroxyl group content in component (A) is an organopolysiloxane resin comprising RSiO _1/2 units (M units) and SiO _4/2 (Q units) prepared by a conventionally known synthesis method (for example, (See U.S. Pat. No. 2,676,182), the silicon-bonded hydroxyl groups remaining therein can be easily reduced by silylation treatment with a silylating agent represented by hexamethylsilazane. The silylation treatment can be catalyzed, for example, with trifluoroacetic acid. Alternatively, trimethylchlorosilane or trimethylsilylacetamide may be reacted with an organoopolysiloxane resin, in which case no catalyst is required.

The component (B) constituting the hydrosilylation reaction-curable silicone-based pressure-sensitive adhesive composition of the present invention has the following average structural formula (1):
R ² R ³ ₂ SiO (R ³ ₂ SiO) _p (R ³ R ⁴ SiO) _q SiR ³ ₂ R ² (1)
It is a linear diorganopolysiloxane having at least two silicon-bonded alkenyl groups having 2 to 10 carbon atoms in one molecule, and is cured by a hydrosilylation reaction with the component (C). Component (B) is one of the main ingredients of the silicone-based pressure-sensitive adhesive composition of the present invention, and may be composed of a single diorganopolysiloxane or from two or more different diorganopolysiloxanes. It may be.

Preferably, the component (B) is a linear diorganopolysiloxane having a silicon atom-bonded alkenyl group represented by the above average structural formula (1), which has a somewhat long chain length, Those having a small content are preferred. By using this component (B) in combination with the component (C) described later, a sheet-like substrate such as a plastic film, in particular, a heat-resistant plastic film substrate, and the hydrosilylation reaction curable silicone pressure-sensitive adhesive of the present invention are used. Adhesiveness with the silicone pressure sensitive adhesive layer formed by curing the agent composition can be significantly improved.

In the average structural formula (1), R ² is a group selected from an alkenyl group having 2 to 10 carbon atoms and a hydroxyl group (—OH). In the average structural formula (1) and the average structural formula (1-1), R ³ is an unsubstituted monovalent hydrocarbon group or a substituted monovalent hydrocarbon group having no aliphatic unsaturated bond having 1 to 10 carbon atoms. R ⁴ is an alkenyl group having 2 to 10 carbon atoms.

Examples of the alkenyl group having 2 to 10 carbon atoms as R ² and R ⁴ include a vinyl group, an allyl group, a propenyl group, a butenyl group, a pentenyl group, and a hexenyl group.

Examples of the unsubstituted monovalent hydrocarbon group having no aliphatic unsaturated bond having 1 to 10 carbon atoms as R ³ include alkyl groups such as methyl group, ethyl group, propyl group, pentyl group, hexyl group, octyl group A cycloalkyl group such as a cyclohexyl group and a cycloheptyl group; an aryl group such as a phenyl group, a tolyl group and a xylyl group; an aralkyl group such as a benzyl group, an α-methylstyryl group and a 2-phenylethyl group. Examples of the substituted monovalent hydrocarbon group having no aliphatic unsaturated bond having 1 to 10 carbon atoms include fluorinated monovalent hydrocarbon groups such as 3,3,3-trifluoropropyl group, 4,4,5 , 5,5-pentafluorobutyl group, 3,3,4,4,5,5,6,6,6-nonafluorohexyl group and the like; chlorinated monovalent hydrocarbon group such as 3 -There are chloroalkyl groups such as chloropropyl groups and chlorophenyl groups such as dichlorophenyl groups.

From the viewpoint of ease of production and compatibility with other siloxane components, the R ³ group in the component (B) molecule is a monovalent saturated aliphatic hydrocarbon group having 1 to 10 carbon atoms (however, at least 50 mol%). Is preferably a methyl group, and of these, at least 85 mol% is preferably a methyl group, and most preferably all methyl groups. Or it consists of a methyl group and a phenyl group, and it is preferable that those at least 50 mol% is a methyl group, and it is more preferable that at least 85 mol% is a methyl group.

The R ² and R ⁴ groups are preferably a vinyl group or a hexenyl group in terms of ease of production and hydrosilylation reactivity.

As preferred components (B), specifically, dimethylpolysiloxane blocked with dimethylvinylsiloxy groups at both ends, methylalkylpolysiloxane blocked with dimethylvinylsiloxy groups at both ends (wherein the alkyl group has 2 to 10 carbon atoms), both Terminal methylphenylvinylsiloxy group-capped dimethylpolysiloxane, both terminal dimethylvinylsiloxy group-capped dimethylsiloxane / methylalkylsiloxane copolymer (wherein the alkyl group has 2 to 10 carbon atoms), both terminal dimethylvinylsiloxy group-capped dimethylsiloxane Examples include methylphenylsiloxane copolymers. The component (B) may be a liquid at normal temperature or a gum that can measure the plasticity, and is particularly preferably a gum that has a degree of polymerization exceeding 3000 as described later.

In the average structural formula (1), the subscript p is a positive number, q is a number of 0 or more, and average (p + q) ≧ 200. (P + q) is preferably in an average range of 200 to 10,000, and more preferably in a range of 450 to 8000. In particular, the average (p + q) ≧ 3000 is preferable, the average (p + q) is in the range of 3000 to 8000, and the component (B) is particularly preferably gum-like at room temperature. On the other hand, when (p + q) is smaller than 200 on average, the degree of cross-linking of the cured product of the pressure-sensitive adhesive composition is too high, and the pressure-sensitive adhesive layer easily falls off from the surface of the sheet-like substrate such as a plastic film. In addition, cohesive failure may be observed during a heat resistance test at a high temperature, and pressure-sensitive adhesiveness may be insufficient. Even if (p + q) exceeds 10,000 on average, it is not impossible to use it due to solvent dilution or the like.

The degree of polymerization p, q is a number satisfying 0 ≦ q / (p + q) ≦ 0.05, and when q / (p + q) exceeds the upper limit, the degree of crosslinking of the cured product of the pressure-sensitive adhesive composition is Too high and pressure-sensitive adhesion may be insufficient. Those having a low alkenyl group content are particularly suitable as the component (B) of the present invention. Most preferably, the component (B) is a diorganopolysiloxane having an average (p + q) ≧ 3000 and a gum and low alkenyl content at room temperature where 0 ≦ q / (p + q) ≦ 0.05. Siloxane. In addition, when q = 0, q / (p + q) = 0, and the component (B) has an alkenyl group only at both ends.

When the total amount of component (A) and component (B) is 100 parts by weight, the amount of component (A) is in the range of 10 to 70 parts by weight, and the amount of component (B) is 90 to 90 parts by weight. Although it is the range of 30 weight part, the compounding quantity of a component (A) is the range of 20-50 weight part, and the compounding quantity of a component (B) is the range of 80-50 weight part. This is because when the component (B) is less than 30 parts by weight, the component (A) tends to remain on the adherend when the pressure-sensitive adhesive is exposed to a high temperature such as 250 ° C. Further, when the component (B) is more than 90 parts by weight, the tackiness is lost and the pressure-sensitive adhesive is not obtained.

Component (C) constituting the hydrosilylation reaction-curable silicone-based pressure-sensitive adhesive composition of the present invention is composed of a number of silicon-bonded hydrogen atoms in the side chain portion of the chain structure represented by the siloxane unit formula (2). It is a linear or branched organohydrogenpolysiloxane having atoms and is a characteristic component of the pressure-sensitive adhesive composition of the present invention.

More specifically, the component (C) is a linear or branched organohydrogenpolysiloxane represented by the average siloxane unit formula (2), and a large number of side chain portions of the linear structure Since it has a silicon atom-bonded hydrogen atom and has a polymerization degree of 100 to 500, when used in the hydrosilylation reaction curable silicone-based pressure-sensitive adhesive composition together with the above component (B), it is a sheet shape such as a plastic film. The adhesion between the substrate, particularly the heat-resistant plastic film substrate and the silicone pressure-sensitive adhesive layer, is significantly improved. The component (C) preferably has a viscosity at 25 ° C. of 80 to 1000 mPa · s in terms of the effect of improving adhesion.

The component (C) is represented by the following siloxane unit formula (2).
(R ¹ ₃ SiO _1/2 ) _k (R ¹ HSiO _2/2 ) _l (R ¹ ₂ SiO _2/2 ) _m (R ¹ SiO _3/2 ) _n (2)
In the formula, R ¹ ₃ SiO _1/2 is a triorganosiloxy unit (M unit) which is a structural unit at the end of the molecular chain,
R ¹ HSiO _2/2 is an organohydrogensiloxy unit ( ^DH unit) that is a structural unit of a polysiloxane chain,
R ¹ ₂ SiO _2/2 is a diorganosiloxy unit (D unit) that is a constituent unit of a polysiloxane chain,
R ¹ SiO _3/2 is an organosiloxy unit (T unit) which is a branch unit.

Examples of the unsubstituted monovalent hydrocarbon group having no C1-C10 aliphatic unsaturated bond as R ¹ in the formula include an alkyl group such as a methyl group, an ethyl group, a propyl group, a pentyl group, Hexyl group, octyl group; cycloalkyl group such as cyclohexyl group and cycloheptyl group; aryl group such as phenyl group, tolyl group and xylyl group; aralkyl group such as benzyl group, α-methylstyryl group and 2-phenylethyl group is there. Examples of the substituted monovalent hydrocarbon group having no aliphatic unsaturated bond having 1 to 10 carbon atoms include fluorinated monovalent hydrocarbon groups such as 3,3,3-trifluoropropyl group, 4,4,5 , 5,5-pentafluorobutyl group, 3,3,4,4,5,5,6,6,6-nonafluorohexyl group and the like; chlorinated monovalent hydrocarbon group such as 3 -There are chloroalkyl groups such as chloropropyl groups and chlorophenyl groups such as dichlorophenyl groups.

From the viewpoint of ease of production and compatibility with other siloxane components, R ¹ group in the molecule of component (C) is a monovalent saturated aliphatic hydrocarbon group having 1 to 10 carbon atoms (however, at least 50 mol%) Is preferably a methyl group, and of these, at least 85 mol% is preferably a methyl group, and most preferably all methyl groups. Or it consists of a methyl group and a phenyl group, and it is preferable that those at least 50 mol% is a methyl group, and it is more preferable that at least 85 mol% is a methyl group.

In the average siloxane unit formula (2), the subscript k is the number of ( 2 + n), l is an average number in the range of 100 to 500, m and n are average 0 or more, and 0.8 ≦ l / ( k + l + m + n) ≦ 1 and 100 ≦ (k + l + m + n) ≦ 500 are satisfied, but (k + l + m + n) is preferably a number such that the viscosity at 25 ° C. is 80 to 1000 mPa · s. When l / (k + l + m + n) is outside the above range (<0.8), the content of organohydrogensiloxy units ( ^DH units) in the molecule is insufficient, and the cured silicone-based pressure-sensitive adhesive layer Adhesiveness to a sheet-like substrate such as a plastic film is deteriorated such as dropping off from the surface of the sheet-like substrate such as a plastic film, and the technical effect of the present invention becomes insufficient. From the viewpoint of the effect of improving the adhesion between a sheet-like substrate such as a plastic film, in particular, a heat-resistant plastic film substrate and a cured silicone pressure-sensitive adhesive layer, k, l, m, and n are 0.00 . 85 ≦ l / (k + l + m + n) ≦ 1.0 is preferably satisfied, 0.90 ≦ l / (k + l + m + n) ≦ 1.0 is more preferable, and 0.95 ≦ l / (k + l + m + n) ≦ 1. Is particularly preferred.

In the average siloxane unit formula (2), k, l, m, and n are preferably k1, l1, m1, and n1 in the average siloxane unit formula (3) shown below.
(R ¹ ₃ SiO _1/2 ) _k1 (R ¹ HSiO _2/2 ) ₁₁ (R ¹ ₂ SiO _2/2 ) _m1 (R ¹ SiO _3/2 ) _n1 (3)

l1 is an average number in the range of 100 to 500, m1 is an average number in the range of 0 to 95, n1 is a number of 0 or 1, k1 is 2 when n1 is 0, and n1 is 1 Is 3. Further, k, l, m, similarly to the n, k1, l1, m1, n1 is, 0 .8 ≦ l1 / (k1 + l1 + m1 + n1) meets ≦ 1 and 100 ≦ (k1 + l1 + m1 + n1) ≦ 500 relationships, (k1 + l1 + m1 + n1) is 25 The number is preferably such that the viscosity at 80 ° C. is 80 to 1,000 mPa · s. The range of “l1 / (k1 + l1 + m1 + n1)” is preferably an average of 0.85 to 1.0, and an average of 0.90 to 1.0 is the same as “l / (k + 1 + m + n)”. More preferred is an average range of 0.95 to 1.0.

In the average siloxane unit formula (2), k, l, m, and n are preferably in the range of 150 ≦ (k + l + m + n) ≦ 300, more preferably 185 ≦ (k + l + m + n) ≦ 215. Similarly, k1, l1, m1, and n1 in the average siloxane unit formula (3) are preferably in the range of 150 ≦ (k1 + l1 + m1 + n1) ≦ 300, more preferably 185 ≦ (k1 + l1 + m1 + n1) ≦ 215.

In the average siloxane unit formula (2) or the average siloxane unit formula (3), l or l1 representing the number of ^DH units is preferably an average number in the range of 150 to 300, and an average range of 185 to 215. It is particularly preferred that In addition, k, l, m, n or k1, l1, m1, n1 are preferably numbers such that the total viscosity of the component (C) at 25 ° C. is 80 to 1,000 mPa · s. When the viscosity is less than 80 mPa · s, the adhesion to a sheet-like substrate such as a plastic film, particularly a heat-resistant plastic film substrate may be inferior. In consideration of ease of production, the viscosity is preferably 1000 mPa · s or less, more preferably a number such that the viscosity of the component (C) is 80 to 500 mPa · s.

In the present invention, the most preferred component (C) is the following average structural formula (4):
R ¹ ₃ SiO (R ¹ HSiO _2/2 ) _l2 (R ¹ ₂ SiO _2/2 ) _m2 SiR ¹ ₃ (4)

Wherein, ^{R 1} is as above, l2 is a number in the range of average 100 to 400, preferably a number in the range of average 150 to 300, particularly preferably in the range of average 185-215 . m2 is a number in the range of average 0 to 95, l2 and m2 satisfies 1 00 ≦ l2 + m2 + 2 ≦ 400 and 0.95 ≦ l2 / (l2 + m2 + 2) ≦ 1 relationship, (l2 + m2 + 2) has a viscosity at 25 ° C. The number is preferably 80 to 500 mPa · s. l2 and m2, more preferably, 1 52 ≦ (l2 + m2 + 2) ≦ 302, particularly preferably satisfies the relation 187 ≦ (l2 + m2 + 2 ) ≦ 217. Furthermore, it is particularly preferable that 0.95 ≦ l2 / (l2 + m2 + 2) ≦ 1.0.

The amount of component (C) is such that the ratio of the number of moles of silicon-bonded hydrogen atoms (SiH groups) in component (C) to the number of moles of alkenyl groups in component (B) is 1 to 100. When this molar ratio is less than 1, the pressure-sensitive adhesive composition may be insufficiently cured. On the other hand, when the molar ratio is larger than 100, there is a concern that a large amount of hydrogen gas is generated from SiH groups remaining without reacting, which is not preferable in terms of product safety.

Component (C) has a ratio of the total number of moles of silicon-bonded hydrogen atoms contained in component (C) to the number of moles of alkenyl groups contained in component (A) (hereinafter referred to as H / Vi) of 1 to 50. In particular, it is desirable to blend such that H / Vi is 8-20.

Component (D) is a hydrosilylation reaction catalyst, preferably a platinum group metal-containing catalyst. The hydrosilylation reaction between the alkenyl group in component (B) and the silicon-bonded hydrogen atom in component (C) is promoted. This hydrosilylation reaction promoting catalyst includes chloroplatinic acid, alcohol solution of chloroplatinic acid, complex of chloroplatinic acid and olefin, complex of chloroplatinic acid and vinylsiloxane, complex of chloroplatinic acid and ketones, platinum Examples thereof include silica powder carrying platinum and platinum black. (C) Although the compounding quantity of a component will not be specifically limited if it is a catalyst amount, the quantity which platinum metal becomes 1-1000 mass ppm with respect to the total amount of a component (A) and a component (B) is preferable. If it is less than 1 ppm by mass, curing may be insufficient. On the other hand, when the amount is more than 1000 ppm by mass, the usable time of the composition may be shortened, and the catalyst is expensive, which is economically disadvantageous.

The hydrosilylation reaction curable silicone-based pressure-sensitive adhesive composition of the present invention comprises the above components (A) to (D), but contains a hydrosilylation reaction inhibitor to improve storage stability at room temperature. It is preferable to do. Specific examples of the hydrosilylation reaction inhibitor include 3-methyl-1-butyn-3-ol, 3,5-dimethyl-1-hexyn-3-ol, 3-methyl-1-penten-3-ol, and phenyl. Alkynyl alcohols such as butynol and 1-ethynyl-1-cyclohexanol; 3-methyl-3-penten-1-yne, 3-methyl-3-hexen-1-yne, 3,5-dimethyl-3-hexene Enyne compounds such as 1-yne, benzotriazole, methylvinylsiloxane cyclic, benzyl alcohol; maleates and fumarate, such as the well-known dialkyl maleates, dialkenyl maleates and dialkoxyalkyl fumarates and dialkyl fumarate, dialkenyl A fumarate is illustrated. The amount of the hydrosilylation reaction inhibitor is usually in the range of 0.001 to 5 parts by weight with respect to 100 parts by weight as the total of the component (A), the component (B), and the component (C).

The hydrosilylation reaction curable silicone-based pressure-sensitive adhesive composition of the present invention comprises the above components (A) to (D), and preferably further contains a hydrosilylation reaction inhibitor, but further to a sheet-like substrate. In order to improve the adhesion of the resin, at least one trialkoxysilane having at least one epoxy group-containing organic group directly bonded to a silicon atom in one molecule or at least one epoxy group-containing organic group directly bonded to a silicon atom in one molecule An organooligosiloxane having at least three alkoxy groups directly bonded to silicon atoms may be blended. Two or more trialkoxysilanes or organooligosiloxanes having an epoxy group-containing organic group may be combined. As a whole compounding quantity of this component, 10 mass parts or less, especially 2 mass parts or less are preferable with respect to 100 mass parts of total amounts of a component (A)-a component (C). When it exceeds 10 mass parts, it will become disadvantageous for hardening of a silicone type pressure sensitive adhesive composition.

Furthermore, the hydrosilylation reaction curable silicone-based pressure-sensitive adhesive composition of the present invention can contain optional components in addition to the above components as long as the properties are not impaired. For example, non-reactive polyorganosiloxanes such as polydimethylsiloxane and polymethylphenylsiloxane; antioxidants such as phenols, quinones and thioethers; light stabilizers such as triazoles and benzophenones; phosphate esters; Halogen-based and antimony-based flame retardants; cationic surfactants, anionic surfactants, nonionic surfactants and other antistatic agents; aromatic hydrocarbon solvents such as toluene and xylene to lower the viscosity during coating , Aliphatic hydrocarbon solvents such as hexane, heptane, octane, isoparaffin, ketone solvents such as methyl ethyl ketone and methyl isobutyl ketone, ester solvents such as ethyl acetate and isobutyl acetate, diisopropyl ether, 1,4-dioxane, etc. Ether solvents or mixed solutions of these ; It may be incorporated dyes, pigments and the like.

In particular, when the hydrosilylation reaction-curable silicone-based pressure-sensitive adhesive composition of the present invention is used for a silicone pressure-sensitive adhesive tape for electronic materials, an antistatic agent is preferably blended.

The method for preparing the hydrosilylation reaction-curable silicone-based pressure-sensitive adhesive composition of the present invention is not particularly limited, and 10 to 70 parts by weight of component (A), 90 to 30 parts by weight of component (B) ( The total of component (A) and component (B) is 100 parts by weight), and if necessary, the solvent is homogeneously mixed. Next, the component (C) is mixed with the mixture, and a hydrosilylation reaction inhibitor is added to the mixture and mixed. Component (D) is preferably added and mixed at the end or just before use.

The hydrosilylation reaction-curable silicone-based pressure-sensitive adhesive composition prepared as described above is applied to various sheet-like substrates and cured under predetermined conditions to form a pressure-sensitive adhesive layer. The sheet-like substrate is preferably a plastic film substrate, particularly a heat-resistant plastic film substrate, from the viewpoint of improving adhesion.

Materials for the sheet-like substrate include polyester, polytetrafluoroethylene, polyimide, polyphenylene sulfide, polyamide, polycarbonate, polystyrene, polypropylene, polyethylene, polyvinyl chloride and other plastic films, aluminum foil, copper foil and other metal foil, Japanese paper And paper such as synthetic paper and polyethylene laminated paper, cloth, glass fiber, and composite base materials formed by laminating a plurality of these. As a material of a plastic film having high heat resistance, for example, polyethylene terephthalate, polyimide, polyether ether ketone (PEEK), polyethylene naphthalate (PEN), liquid crystal polyarylate, polyamide imide (PAI), polyether sulfone (PES), etc. It is a heat-resistant plastic.

The hydrosilylation reaction-curable silicone-based pressure-sensitive adhesive composition of the present invention has a pressure-sensitive adhesive layer that is a cured product layer, that is, the pressure-sensitive adhesive layer has good adhesion to a sheet-like substrate such as a plastic film. In order to further improve the adhesion, a sheet-like substrate such as a plastic film subjected to primer treatment, corona treatment, etching treatment, plasma treatment, or the like may be used.

The coating method for a sheet-like substrate such as a plastic film may be a known coating method, such as a comma coater, a lip coater, a roll coater, a die coater, a knife coater, a blade coater, a rod coater, a xy rotater, and a gravure. Examples include coater, screen coating, dip coating, and cast coating. Moreover, although the coating amount is set according to a use, typically, the thickness of the pressure-sensitive adhesive agent layer after hardening is 2-300 micrometers normally.

The curing conditions of the applied hydrosilylation reaction curable silicone-based pressure-sensitive adhesive composition are appropriately adjusted according to the composition, coating amount, etc., but the temperature is up to 300 ° C., preferably 80 to 150 ° C. Temperature is 30 seconds to 5 minutes.

Useful articles that can be prepared with the hydrosilylation reaction curable silicone pressure sensitive adhesive composition of the present invention include pressure sensitive tapes, pressure sensitive labels, insignia with silicone pressure sensitive adhesive layers on the back and other decorative Alternatively, a transmission label (for example, a decoration label for a storefront display) may be included. In particular, the laminate obtained using the hydrosilylation reaction curable silicone-based pressure-sensitive adhesive composition of the present invention is suitable for electronic material applications, such as heat-resistant tape, electrical insulating tape, heat seal tape, plating masking tape, etc. It is useful and preferred to be a silicone pressure-sensitive adhesive tape used in the above-mentioned applications.

EXAMPLES Hereinafter, although an Example and a comparative example are shown and this invention is demonstrated concretely, this invention is not limited to the following Example. In each example, the viscosity (kinematic viscosity) is a measured value at 25 ° C. “Parts” in the blending amount means “parts by mass”, and “%” in the content means% by mass. ppm means ppm by mass. “Me” in the formula means a methyl group. The “platinum-based catalyst” is a complex of chloroplatinic acid and 1,3-divinyl-1,1,3,3-tetramethyldisiloxane.
In the following Examples and Comparative Examples, adhesion to a plastic film substrate that is a sheet-like substrate was measured and evaluated by the following method.

(Evaluation method: Tear method)
After coating the silicone pressure-sensitive adhesive composition on a support (sheet-like substrate) made of a polyethylene terephthalate (PET) resin film so that the cured pressure-sensitive adhesive layer has a thickness of about 30 μm. The adhesive sheet was prepared by heating at 120 ° C. for 2 minutes. Next, this adhesive sheet was aged at 25 ° C. and 60% RH for 1 day. A slit was made by cutting to a width of 20 mm, and a length of 1-2 mm was cut in the width direction. The elongation of the silicone pressure-sensitive adhesive layer from the notch to the slit in the slit length direction until complete tearing was measured.
Further, if the elongation of the silicone pressure-sensitive adhesive layer is 20 mm or less, the adhesion is “◯ (good)”, 20 to 50 mm is “x (defect)”, and if it exceeds 50 mm, “xx (particularly poor). ) ”.

[Example 1]
(A) A methyl polysiloxane resin _{composed of} Me ₃ SiO _1/2 units and SiO _4/2 units and having a molar ratio of Me ₃ SiO _1/2 units / SiO _4/2 units = 0.8 is obtained as a solid content. 57.3 parts of xylene solution containing 65.0% in terms of conversion, (B) dimethylpolysiloxane having both ends of the molecular chain blocked with dimethylvinylsiloxy groups and having a vinyl group only at the end of the molecular chain (vinyl group content is 0.00. 26.0% by mole, average polymerization degree is 3600, and gum is formed at 25 ° C.) 26.0 parts, (C) Average siloxane unit formula is the following formula (5)
Me ₃ SiO (MeHSiO _2/2 ) ₁₉₈ SiMe ₃ (5)
Represented by the formula, 0.2 parts of trimethylsiloxy group-blocked methylhydrogenpolysiloxane having a viscosity of 200 mPa · s, (D) platinum-based catalyst, based on the total amount of component (A) and component (B) Then, an amount of platinum metal of 100 ppm, 66.6 parts of toluene and 0.2 part of methylbutynol are mixed at room temperature to prepare a silicone-based pressure-sensitive adhesive composition having an organopolysiloxane component of about 40%. did.
Next, an adhesive tape was prepared by applying an applicator to this silicone pressure-sensitive adhesive on a film made of polyethylene terephthalate resin so that the coating thickness was 40 μm, and the adhesion was evaluated by the above method.

[Example 2]
In Example 1, as component (C), the average siloxane unit formula (6)
(Me ₃ SiO _1/2 ) ₃ (MeHSiO _2/2 ) ₂₀₀ (Me ₂ SiO _3/2 ) ₁ (6)
A silicone-based pressure-sensitive adhesive composition was prepared in the same manner as in Example 1 except that 0.2 parts of trimethylsiloxy group-blocked methylhydrogenpolysiloxane having a viscosity of 200 mPa · s was used. Prepared and evaluated for adhesion.

[Comparative Example 1]
In Example 1, as component (C), the average siloxane unit formula (7)
Me ₃ SiO (MeHSiO _2/2 ) ₁₄₀ (Me ₂ SiO _2/2 ) ₆₀ SiMe ₃ (7)
In the same manner as in Example 1, a silicone-based pressure-sensitive adhesive was used except that 0.2 parts of a trimethylsiloxy group-blocked dimethylsiloxane / methylhydrogensiloxane copolymer having a molecular chain having a viscosity of 200 mPa · s was used. Compositions were prepared and evaluated for adhesion.

[Comparative Example 2]
In Example 1, as component (C), the average siloxane unit formula (8)
Me ₃ SiO (MeHSiO _2/2 ) ₅₀ SiMe ₃ (8)
A silicone-based pressure-sensitive adhesive composition was prepared in the same manner as in Example 1 except that 0.2 parts of a trimethylsiloxy group-blocked methylhydrogenpolysiloxane having a viscosity of 30 mPa · s was used. Prepared and evaluated for adhesion.

[Comparative Example 3]
In Example 1, as component (C), the average siloxane unit formula (9)
Me ₃ SiO (MeHSiO _2/2 ) ₅₅ (Me ₂ SiO _2/2 ) ₂₇ SiMe ₃ (9)
In the same manner as in Example 1, a silicone-based pressure-sensitive adhesive was used except that 0.2 parts of a trimethylsiloxy group-blocked dimethylsiloxane / methylhydrogensiloxane copolymer having a molecular chain viscosity of 55 mPa · s was used. Compositions were prepared and evaluated for adhesion.

Table 1 shows the structure of each component used in each silicone-based pressure-sensitive adhesive composition, the SiH / Vi ratio, and the adhesion evaluation results of each silicone-based pressure-sensitive adhesive composition.

As can be seen from the above examples and comparative examples, the silicone pressure-sensitive adhesive layer obtained by curing the hydrosilylation reaction-curable silicone pressure-sensitive adhesive composition of the present invention is a sheet-like substrate such as a plastic film, particularly Was excellent in adhesion to a heat-resistant plastic film substrate represented by polyethylene terephthalate. Specifically, in the examples of the present invention, the elongation of the silicone pressure-sensitive adhesive layer measured by the above-described tearing method is 5 mm or 15 mm, and the adhesiveness to the film substrate is high. In the comparative example in which the adhesive layer is cut without being greatly deformed as the film is torn but the value of l / (k + l + m + n), the degree of polymerization, etc. are different, the silicone pressure-sensitive adhesive layer As a result, the film was deformed as the film was torn, and the elongation of the silicone pressure-sensitive adhesive layer reached 45 mm or more.

The hydrosilylation reaction-curable silicone pressure-sensitive adhesive composition of the present invention is useful for forming a pressure-sensitive adhesive layer such as a heat-resistant tape, an electrical insulating tape, a heat seal tape, and a plating masking tape.
The laminate of the present invention is useful as an adhesive tape, a heat resistant adhesive tape, an electrical insulating adhesive tape, a heat seal adhesive tape, a masking adhesive tape, and the like.
The silicone adhesive tape of the present invention is useful as a heat-resistant adhesive tape, an electrical insulating adhesive tape, a heat seal adhesive tape, a masking adhesive tape, and the like.

Claims (8)

A hydrosilylation reaction-curable silicone-based pressure-sensitive adhesive composition comprising the following components (A) to (D).
(A) (a) R ₃ SiO _1/2 unit (wherein R is an unsubstituted monovalent hydrocarbon group or substituted monovalent hydrocarbon group having 1 to 10 carbon atoms) and (b) SiO _{4 / An} organopolysiloxane resin consisting essentially of ₂ units, the molar ratio of (a) units to (b) units being in the range of 0.6: 1 to 1.2: 1; 10 to 70 parts by weight;
(B) The following average structural formula (1):
R ² R ³ ₂ SiO (R ³ ₂ SiO) _p (R ³ R ⁴ SiO) _q SiR ³ ₂ R ² (1)
(In the formula, R ² is a group selected from an alkenyl group having 2 to 10 carbon atoms and a hydroxyl group, and R ³ is an unsubstituted monovalent hydrocarbon having no aliphatic unsaturated bond having 1 to 10 carbon atoms. A group or a substituted monovalent hydrocarbon group, R ⁴ is an alkenyl group having 2 to 10 carbon atoms, p is a positive number, q is a number of 0 or more, and satisfies the relationship of ( p + q) ≧ 200 Provided that when q is 1, at least one of R ² is the alkenyl group, and when q is 0, R ² is any of the alkenyl groups.) Linear diorganopolysiloxane having 2 to 10 silicon atom-bonded alkenyl groups; 30 to 90 parts by mass (the total of component (A) and component (B) is 100 parts by mass) ),
(C) The following average siloxane unit formula (2):
(R ¹ ₃ SiO _1/2 ) _k (R ¹ HSiO _2/2 ) _l (R ¹ ₂ SiO _2/2 ) _m (R ¹ SiO _3/2 ) _n (2)
(Wherein R ¹ is an unsubstituted monovalent hydrocarbon group or a substituted monovalent hydrocarbon group having no aliphatic unsaturated bond having 1 to 10 carbon atoms, k is the number of ( 2 + n) , and l Is an average number in the range of 100 to 500, m and n are average numbers of 0 or more, and 0.8 ≦ l / (k + l + m + n) ≦ 1 and 100 ≦ (k + l + m + n) ≦ 500) An amount such that the molar ratio of silicon-bonded hydrogen atoms in component (C) to the alkenyl group in component (B) ranges from 1 to 100, and (D) hydrosilylation Reaction catalyst; catalyst amount The component (C) is represented by the following average siloxane unit formula (3) :
(R ¹ ₃ SiO _1/2 ) _k1 (R ¹ HSiO _2/2 ) ₁₁ (R ¹ ₂ SiO _2/2 ) _m1 (R ¹ SiO _3/2 ) _n1 (3)
Wherein R ¹ is as described above, l1 is an average number in the range of 100 to 500, m1 is an average number in the range of 0 to 95, n1 is a number of 0 or 1, and k1 is n1 is 2 when 0, n1 is 3 when 1 .k1, l1, m1 and n1 satisfies 0 .8 ≦ l1 / (k1 + l1 + m1 + n1) ≦ 1 and 100 ≦ (k1 + l1 + m1 + n1) ≦ 500 relationship The hydrosilylation reaction-curable silicone-based pressure-sensitive adhesive composition according to claim 1, which is a linear or branched organohydrogenpolysiloxane represented by the formula: The component (C) has the following average structural formula (4):
R ¹ ₃ SiO (R ¹ HSiO _2/2 ) _l2 (R ¹ ₂ SiO _2/2 ) _m2 SiR ¹ ₃ (4)
(Wherein R ¹ is as described above, l2 is an average number in the range of 100 to 400, m2 is an average number in the range of 0 to 95, and l2 and m2 are 100 ≦ l2 + m2 + 2 ≦ 400 and 0 The hydrosilylation reaction-curable silicone-based pressure-sensitive adhesive composition according to claim 1, which is a linear organohydrogenpolysiloxane represented by the following relationship: .95 ≦ l2 / (l2 + m2 + 2) ≦ 1). The component (B) is shown by the above average structural formula (1), to further satisfy the relationship (p + q) ≧ 3000 and 0 ≦ q / (p + q ) ≦ 0.05, claims 1 4. The hydrosilylation reaction-curable silicone pressure-sensitive adhesive composition according to any one of 3 above. A silicone-based pressure-sensitive adhesive obtained by curing the hydrosilylation reaction-curable silicone-based pressure-sensitive adhesive composition according to any one of claims 1 to 4 on a sheet-like substrate and a sheet-like substrate. Laminate with layers. The laminate according to claim 5, wherein the sheet-like substrate is a heat-resistant plastic film substrate. The silicone adhesive tape which consists of a laminated body of Claim 5 whose sheet-like base material is a plastic film tape. The silicone adhesive tape according to claim 7, wherein the plastic film tape is a heat-resistant plastic film tape.