WO2021171734A1

WO2021171734A1 - Pressure-sensitive silicone adhesive composition

Info

Publication number: WO2021171734A1
Application number: PCT/JP2020/045947
Authority: WO
Inventors: 土田　理
Original assignee: 信越化学工業株式会社
Priority date: 2020-02-25
Filing date: 2020-12-10
Publication date: 2021-09-02
Also published as: JP7321954B2; CN115066476A; KR20220146433A; JP2021134244A

Abstract

This pressure-sensitive silicone adhesive composition comprises (A) an organopolysiloxane having two or more alkenyl-group-containing organic groups in the molecule and containing alkenyl groups in an amount of 0.0002-0.05 mol per 100 g of the organopolysiloxane, (B) a polyorganosiloxane comprising an R² ₃SiO_1/2 unit and an SiO_4/2 unit, the (R² ₃SiO_1/2 unit)/(SiO_4/2 unit) molar ratio being 0.6-1.0, (C) a polyorganohydrogensiloxane represented by R³ _eH_fSiO_(4-e-f)/2 and having three or more Si-H groups in the molecule, (D) a platinum-group metal catalyst for curing the composition by causing the alkenyl groups of the composition to undergo hydrosilylation addition with the Si-H groups of the (C) ingredient, and (E) a silicon-free thermoplastic resin. Due to this, provided is a pressure-sensitive silicone adhesive composition which has controlled tackiness due to the addition of an ingredient which is not a silicone resin and which combines high adhesive force with high tack.

Description

Silicone adhesive composition

The present invention relates to a silicone pressure-sensitive adhesive having a novel composition.

Adhesives are a type of adhesive, and are often used in the form of adhesive tapes and adhesive labels that are hardened by applying an adhesive to the base material, and adhesive tapes are the adhesives that we usually see. It is a typical article that uses an agent. These items have a wide range of uses, such as being used as labels to identify things, being used for packing luggage, or for joining multiple items together.

There are several types of base materials for forming adhesives, which are roughly classified into rubber-based, acrylic-based, and silicone-based. Rubber-based adhesives are general-purpose base materials that have been used for a long time, and are used in products such as general-purpose tapes at low prices. Acrylic adhesives are based on polyacrylates and have better chemical properties than rubber adhesives, so they can also be applied to adhesive products with higher functionality than rubber adhesives. The silicone-based adhesive is composed of high-viscosity silicone raw rubber (gum) and silicone resin, and has various excellent characteristics because the main chain has a large number of siloxane bonds. Specifically, it has heat resistance, cold resistance, and weather resistance. Properties, chemical resistance, electrical insulation, etc. can be mentioned.

Silicone adhesives are used in high-performance industrial tapes such as heat-resistant tapes, masking tapes for processes, and flame-retardant mica tapes, taking advantage of the excellent properties described above, and are used in harsh environments. It is used in situations where it can exhibit its characteristics even underneath.

As described above, the main components of the silicone adhesive are gum and silicone resin, but the adhesive properties are controlled by changing the composition of these two components (Patent Documents 1 to 3). Gum is a base polymer, which is soft and easily wets the surface. Silicone resin is used as a tackifier and plays a role of imparting tackiness by blending with the base polymer. It is true that the addition of silicone resin can increase the adhesive strength of the silicone adhesive composition, but there is a limit to the amount of increase in adhesive strength due to the addition of silicone resin. The current situation is that the characteristics themselves are limited. However, it is difficult to simply control the adhesive properties with components other than the silicone resin, and it is difficult to bring out the performance while being compatible with the base gum.

Japanese Patent No. 5117713 Japanese Patent No. 6091518 Japanese Patent No. 6348434

Therefore, an object of the present invention is to provide a silicone pressure-sensitive adhesive composition having both high adhesive strength and high tack by controlling the adhesive properties by adding a component other than the silicone resin.

In order to solve the above problems, in the present invention, the silicone pressure-sensitive adhesive composition is used.
(A) Organopolysiloxane represented by the average composition formula (1), which has two or more alkenyl group-containing organic groups in one molecule and contains 0.0002 to 0.05 mol of alkenyl groups in 100 g. : 60 to 30 parts by mass,

(R ¹ is a monovalent hydrocarbon group having 1 to 10 carbon atoms, which may be the same or different, and ^{two or more of R 1} contain an alkenyl group-containing organic group having 2 to 10 carbon atoms. An integer of 2 or more, b is an integer of 1 or more, c and d are integers of 0 or more, and 50 ≦ a + b + c + d ≦ 15000.)
(B) ^{Includes R 2} ₃ SiO _1/2 unit and SiO _4/2 unit, and (R ² ₃ SiO _1/2 unit) / (SiO _4/2 unit) is 0.6 to 1.0 in molar ratio. A polyorganosiloxane (R ² represents a monovalent hydrocarbon group having 1 to 10 carbon atoms or an alkenyl group having 2 to 6 carbon atoms, each independently having no aliphatic unsaturated bond): 40 to 70 parts by mass. ,
(C) Polyorganohydrogensiloxane represented by the following average composition formula (2) and having 3 or more Si—H groups in one molecule: Si—H groups are molar relative to the alkenyl groups in the composition. Amount of 0.2 to 20 in ratio,
R ³ _e H _f SiO _{(4-ef) / 2} Average composition formula (2)
(R ³ represents an unsubstituted or substituted monovalent hydrocarbon group having 1 to 10 carbon atoms excluding the aliphatic unsaturated group, e> 0, f> 0, and 0 <e + f ≦ 3).
(D) Platinum group metal-based catalyst for hydrosilylating and adding the alkenyl group in the composition and the Si—H group of the component (C) to cure: the total amount of the components (A) to (C) On the other hand, the amount of metal is 1 to 500 ppm,
(E) Silicon-free thermoplastic resin: 0.1 to 3 parts by mass with respect to the total amount of the components (A) to (C).
Provided is a silicone pressure-sensitive adhesive composition comprising.

With such a composition, the adhesive properties can be controlled by adding a component other than the silicone resin, and both high adhesive strength and high tack can be achieved at the same time.

Further, in the present invention, the (F) control agent can further contain 0.01 to 5 parts by mass with respect to the total amount of the components (A) to (C).

With such a composition, the effect of the present invention can be further improved.

Further, in the present invention, the component (E) can be represented by the following formula (3).

(R ⁴ , R ⁵ , and R ⁶ are monovalent hydrocarbon groups having 1 to 5 carbon atoms, which may be the same or different, respectively, and m and n are integers of 1 or more, and 1 ≦ m ≦ 20, 1 ≦. n ≦ 20.)

If it is such a thing, the adhesive property can be controlled by the components other than the silicone resin by adjusting the addition amount, and the performance can be brought out while being compatible with the base gum.

Further, in the present invention, the hydroxyl value of the component (E) can be 10 to 300 mgOH / g.

With such a thing, the effect of the present invention can be further improved.

Further, the present invention provides an adhesive article having a cured product of the above silicone pressure-sensitive adhesive composition on one side or both sides of a base material.

If it is such a thing, it can be made into an adhesive article having both higher adhesive strength and higher tack than before.

The silicone pressure-sensitive adhesive composition of the present invention can achieve both higher adhesive strength and higher tack than conventional ones, and by using this, it is possible to obtain an adhesive article having both higher adhesive strength and higher tack than conventional ones. Can be done.

As mentioned above, there has been a demand for the development of a silicone pressure-sensitive adhesive composition that has both high adhesive strength and high tack.

As a result of diligent studies on the above problems, the present inventors have obtained a silicone pressure-sensitive adhesive composition having both high adhesive strength and high tack by controlling the adhesive properties by adding a thermoplastic resin containing no silicon. The present invention has been completed.

That is, the present invention is a silicone pressure-sensitive adhesive composition.
(A) Organopolysiloxane represented by the average composition formula (1), which has at least two alkenyl group-containing organic groups in one molecule and contains 0.0002 to 0.05 mol of alkenyl groups in 100 g. 60 to 30 parts by mass,

(R ¹ is a monovalent hydrocarbon group having 1 to 10 carbon atoms, which may be the same or different, and ^{at least two of R 1} contain an alkenyl group-containing organic group having 2 to 10 carbon atoms. An integer of 2 or more, b is an integer of 1 or more, c and d are integers of 0 or more, and 50 ≦ a + b + c + d ≦ 15000.)
(B) ^{Includes R 2} ₃ SiO _1/2 unit and SiO _4/2 unit, and (R ² ₃ SiO _1/2 unit) / (SiO _4/2 unit) is 0.6 to 1.0 in molar ratio. A polyorganosiloxane (R ² represents a monovalent hydrocarbon group having 1 to 10 carbon atoms or an alkenyl group having 2 to 6 carbon atoms, each independently having no aliphatic unsaturated bond): 40 to 70 parts by mass. ,
(C) Polyorganohydrogensiloxane represented by the following average composition formula (2) and having at least 3 Si—H groups in one molecule: Si—H groups are molar relative to the alkenyl groups in the composition. Amount of 0.2 to 20 in ratio,
R ³ _e H _f SiO _{(4-ef) / 2} Average composition formula (2)
(R ³ represents an unsubstituted or substituted monovalent hydrocarbon group having 1 to 10 carbon atoms excluding the aliphatic unsaturated group, e> 0, f> 0, and 0 <e + f ≦ 3).
(D) Platinum group metal-based catalyst for hydrosilylating and adding the alkenyl group in the composition and the Si—H group of the component (C) to cure: the total amount of the components (A) to (C) On the other hand, the amount of metal is 1 to 500 ppm,
(E) Silicon-free thermoplastic resin: 0.1 to 3 parts by mass with respect to the total amount of the components (A) to (C).
It is a silicone pressure-sensitive adhesive composition comprising.

Hereinafter, the present invention will be described in detail, but the present invention is not limited thereto.

[(A) component]
The component (A) is an organopoly having at least two alkenyl group-containing organic groups in one molecule represented by the following average composition formula (1) and containing 0.0002 to 0.05 mol of alkenyl groups in 100 g. It is a siloxane.

(R ¹ is a monovalent hydrocarbon group having 1 to 10 carbon atoms, which may be the same or different, and ^{at least two of R 1} contain an alkenyl group-containing organic group having 2 to 10 carbon atoms. An integer of 2 or more, b is an integer of 1 or more, c and d are integers of 0 or more, and 50 ≦ a + b + c + d ≦ 15000.)

R ¹ is a monovalent hydrocarbon group having 1 to 10 carbon atoms, and two or more of them are alkenyl group-containing organic groups having 2 to 10 carbon atoms. The number of alkenyl group-containing organic group having 2 to 10 carbon atoms for R ¹ is not particularly limited as long as it is two or more, all of R ¹ may be an alkenyl group-containing organic group having 2 to 10 carbon atoms.

Specific examples of the monovalent hydrocarbon group include an alkyl group such as a methyl group, an ethyl group, a propyl group and a butyl group, a cycloalkyl group such as a cyclohexyl group, an aryl group such as a phenyl group, and the like. , A part or all of the hydrogen atom bonded to the carbon atom of these groups may be substituted with a halogen atom or another group, and examples thereof include a trifluoromethyl group, a 3,3,3-trifluoropropyl group and the like. Will be done. Among the above, a saturated aliphatic group or aromatic group is preferable, and a methyl group and a phenyl group are particularly preferable.

The alkenyl group-containing organic group has 2 to 10 carbon atoms, and examples thereof include an alkenyl group such as a vinyl group, an allyl group, a hexenyl group and an octenyl group, an acryloylpropyl group, an acryloylmethyl group and a methacryloylpropyl group. Examples thereof include a cycloalkenylalkyl group such as an acryloylalkyl group and a methacryloylalkyl group, a cyclohexenylethyl group, and an alkenyloxyalkyl group such as a vinyloxypropyl group. Of these, a vinyl group is particularly preferable.

The amount of the alkenyl group contained in the component (A) is 0.0002 to 0.05 mol, preferably 0.0004 to 0.04 mol, and 0.0005 to 0.03 mol per 100 g of the organopolysiloxane. Mol is more preferred. If it is less than 0.0002 mol, the crosslink density becomes small and the adhesive layer may be coagulated and broken. If it is more than 0.05 mol, the adhesive layer becomes hard and appropriate adhesive strength and tack may not be obtained. ..

Regarding a to d in the average composition formula (1), a is an integer of 2 or more, b is an integer of 1 or more, c and d are integers of 0 or more, and 50 ≦ a + b + c + d ≦ 15000, preferably 200 ≦ a + b + c + d ≦. It is 12000. When a + b + c + d is smaller than 50, the reaction is delayed due to too many cross-linking points, and when it is larger than 15000, the viscosity of the composition becomes very high and the handleability deteriorates.

The component (A) is usually produced by ring-opening polymerization of a cyclic small molecule siloxane such as octamethylcyclotetrasiloxane using a catalyst, but after the polymerization, it contains a cyclic small molecule siloxane as a raw material. It is preferable to use the one obtained by distilling off the inert gas under heating and reduced pressure while aerating an inert gas through the reaction product.

Examples of the component (A) include, but are not limited to, those represented by the following general formulas.
R ^1-1 R ^1-2 ₂ SiO (R ^1-2 ₂ SiO) _p SiR ^1-2 ₂ R ^1-1
R ^1-1 R ^1-2 ₂ SiO (R ^1-2 ₂ SiO) _p (R ^1-1 R ^1-2 SiO) _q SiR ^1-2 ₂ R ^1-1
R ^1-1 ₃ SiO (R ^1-2 ₂ SiO) _p (R ^1-1 R ^1-2 SiO) _q SiR ^1-1 ₃
R ^1-2 ₃ SiO (R ^1-2 ₂ SiO) _p (R ^1-1 R ^1-2 SiO) _q SiR ^1-2 ₃
(In the formula, R ^1-1 is the same or different alkenyl group-containing organic group, and R ^1-2 is a monovalent hydrocarbon having 1 to 10 carbon atoms which does not have the same or different aliphatic unsaturated bonds. It is a hydrogen group, and p ≧ 47 and q ≧ 1 (however, if the molecule ^{does not have R 1-1} other than ^{(R 1-1} R ^1-2 SiO) _q , q ≧ 2). )

Examples of R ^1-1 and R ^1-2 include those exemplified in ^{R 1 above.} It should be noted that 47 ≦ p ≦ 11,998 is preferable, 1 ≦ q ≦ 1,000 is preferable, and 2 ≦ q ≦ 800 is more preferable.

More specific component (A) includes, but is not limited to, those represented by the following general formula. Me, Vi, and Ph in the following formula represent a methyl group, a vinyl group, and a phenyl group, respectively.

[(B) component]
The component (B) is R ² ₃ SiO _1/2 unit (R ² is a monovalent hydrocarbon group having 1 to 10 carbon atoms or an alkenyl having 2 to 6 carbon atoms, each of which does not independently have an aliphatic unsaturated bond. The group is included.) And SiO _4/2 units, and (R ² ₃ SiO _1/2 units) / (SiO _4/2 units) has a molar ratio of 0.6 to 1.0, preferably 0. It is a polyorganosiloxane of 65 to 0.9. If this molar ratio is less than 0.6, the adhesive strength and tack may decrease, and if it exceeds 1.0, the adhesive strength and holding power may decrease.

R ² represents a monovalent hydrocarbon group having 1 to 10 carbon atoms or an alkenyl group having 2 to 6 carbon atoms, which do not independently have an aliphatic unsaturated bond, and R ² has 1 to 10 carbon atoms. The monovalent hydrocarbon group includes an alkyl group such as a methyl group, an ethyl group, a propyl group and a butyl group, preferably an alkyl group having 2 to 6 carbon atoms, an aryl group such as a phenyl group and a trill group, and preferably a carbon atom. The number 6 to 10 aryl groups can be mentioned. Examples of the alkenyl group having 2 to 6 carbon atoms include a vinyl group, an allyl group, a butenyl group and the like.

Two or more kinds of the component (B) may be used in combination. Further, if necessary, R ² SiO _3/4 unit and R ² ₂ SiO _2/2 unit can be contained in the component (B).

The component (B) may condense hydrolyzable groups present on its surface in the presence of a catalyst. This is expected to have the effect of improving the adhesive strength of the pressure-sensitive adhesive composition, and may be reacted at room temperature to reflux using an alkaline catalyst and neutralized if necessary.

As alkaline catalysts, metal hydroxides such as lithium hydroxide, sodium hydroxide, potassium hydroxide and calcium hydroxide; carbonates such as sodium carbonate and potassium carbonate; hydrogen carbonates such as sodium hydrogen carbonate and potassium hydrogen carbonate; Metal alkoxides such as sodium methoxydo and potassium butoxide; Organic metals such as butyl lithium; Potassium silanolate; Nitrogen compounds such as ammonia gas, aqueous ammonia, methylamine, trimethylamine and triethylamine, but ammonia gas or aqueous ammonia preferable. The temperature of the condensation reaction may be from room temperature to the reflux temperature of the organic solvent. The reaction time is not particularly limited, but may be 0.5 to 20 hours, preferably 1 to 16 hours.

Furthermore, after the reaction is completed, a neutralizing agent that neutralizes the alkaline catalyst may be added, if necessary. Examples of the neutralizing agent include acidic gases such as hydrogen chloride and carbon dioxide; organic acids such as acetic acid, octyl acid and citric acid; and mineral acids such as hydrochloric acid, sulfuric acid and phosphoric acid. When ammonia gas or aqueous ammonia or an amine compound having a low boiling point is used as the alkaline catalyst, an inert gas such as nitrogen may be aerated and distilled off.

The compounding amount of the component (A) is 60 to 30 parts by mass, the compounding amount of the component (B) is 40 to 70 parts by mass, and the compounding mass ratio of the components (A) and (B) is (A) / (. B) = 60/40 to 30/70, more preferably 55/45 to 35/65. When the total of the components (A) and (B) is 100, if the ratio of the component (B) is less than 40, the compatibility of the component (E) described later may deteriorate, and if it exceeds 70, the composition Heat resistance may deteriorate.

[(C) component]
The component (C) is a polyorganohydrogensiloxane represented by the following average composition formula (2) and having at least 3 Si—H groups in one molecule.
R ³ _e H _f SiO _{(4-ef) / 2} Average composition formula (2)
(R ³ represents an unsubstituted or substituted monovalent hydrocarbon group having 1 to 10 carbon atoms excluding the aliphatic unsaturated group, e> 0, f> 0, and 0 <e + f ≦ 3).

R ³ is a monovalent hydrocarbon group having 1 to 10 carbon atoms excluding the aliphatic unsaturated group. Specifically, for example, it is an alkyl group such as a methyl group, an ethyl group, a propyl group or a butyl group, a cycloalkyl group such as a cyclohexyl group, an aryl group such as a phenyl group, or the like, and is further bonded to a carbon atom of these groups. A part or all of the hydrogen atom may be substituted with a halogen atom or another group, and a trifluoromethyl group, a 3,3,3-trifluoropropyl group and the like are exemplified. As the monovalent hydrocarbon group, a saturated aliphatic group or aromatic group is preferable, and a methyl group and a phenyl group are particularly preferable.

E and f in the average composition formula (2) are numbers satisfying e> 0, f> 0 and 0 <e + f ≦ 3, preferably e> 0, f> 0 and 0 <e + f <3. be.

The component (C) can be exemplified by the following general formula (4), but is not limited thereto.
R ⁷ ₃ Si-O- (SiR ⁸ _2- O) _r- (SiR ⁹ HO) _s- O-SiR ¹⁰ ₃ General formula (4)
(R ⁷ and R ¹⁰ represent monovalent hydrocarbon groups or hydrogen atoms having 1 to 10 carbon atoms excluding aliphatic unsaturated groups, respectively, and R ⁸ and R ⁹ have 1 to 10 carbon atoms excluding aliphatic unsaturated groups, respectively. It represents 10 monovalent hydrocarbon groups, where r is 0 ≦ r ≦ 100 and s is 3 ≦ s ≦ 80).

R ⁸ and R ⁹ each represent a monovalent hydrocarbon group having 1 to 10 carbon atoms excluding an aliphatic unsaturated group, and for example, an alkyl group such as a methyl group, an ethyl group, a propyl group or a butyl group, a cyclohexyl group or the like. Examples thereof include an aryl group such as a cycloalkyl group and a phenyl group. Further, a part or all of the hydrogen atoms bonded to the carbon atoms of these groups may be substituted with halogen atoms or other groups, and trifluoromethyl groups, 3,3,3-trifluoropropyl groups and the like may be substituted. Can be mentioned. As R ⁸ and R ⁹ , saturated aliphatic groups or aromatic groups are preferable, and methyl groups and phenyl groups are particularly preferable.

R ⁷ and R ¹⁰ are monovalent hydrocarbon groups or hydrogen atoms having 1 to 10 carbon atoms excluding aliphatic unsaturated groups, respectively. As the ^{monovalent hydrocarbon group having 1 to 10 carbon atoms of R 7} and R ^10, the same as above is exemplified, r is 0 ≦ r ≦ 100, and 0 ≦ r ≦ 80 or 0 <r ≦ 80. Is preferable, s is 3 ≦ s ≦ 80, and 4 ≦ s ≦ 70 is preferable.

The amount of the component (C) used is such that the molar ratio of the Si—H group in the component (C) to the alkenyl group in the composition is 0.2 to 20, and particularly in the range of 0.5 to 15. It is preferable to do so. If it is less than 0.2, the cross-linking density becomes low, which may result in low cohesive force and holding power. If it exceeds 20, the crosslink density becomes high, and appropriate adhesive strength and tack may not be obtained.

The component (C) is usually produced by ring-opening polymerization of a cyclic low molecular weight siloxane such as octamethylcyclotetrasiloxane and a Si—H-containing siloxane such as tetramethylcyclotetrasiloxane using an acid catalyst. After that, since it contains cyclic low-molecular-weight siloxane as a raw material, it is preferable to use the one obtained by distilling it under heating and reduced pressure while aerating an inert gas through the reaction product.

Examples of the concrete structure of the component (C) include those shown in the following general formulas, but are not limited thereto. In addition, Me in the following general formula represents a methyl group.

[(D) component]
The component (D) is a platinum group metal-based catalyst for hydrosilylating and adding an alkenyl group in the composition and a Si—H group in the component (C) to cure them, and the central metals are platinum, palladium, and iridium. , Rhodium, osmium, ruthenium and the like are given as examples, and platinum is particularly preferable. Examples of the platinum catalyst include platinum chloride, an alcohol solution of platinum chloride, a reaction product of platinum chloride acid and alcohol, a reaction product of platinum chloride acid and an olefin compound, and a reaction product of platinum chloride acid and a vinyl group-containing siloxane. Can be mentioned.

The content of the component (D) is preferably such that the amount of metal is 1 to 500 ppm in terms of mass with respect to the total amount of the components (A), (B) and (C), and more preferably 2 to 450 ppm. .. If it is less than 1 ppm, the reaction is slow and the curing is insufficient, so that various characteristics of adhesive strength and holding power may not be exhibited. If it exceeds 500 ppm, the flexibility of the cured product may become poor.

[(E) component]
The component (E) is a silicon-free thermoplastic resin. The thermoplastic resin does not contain silicon, and is not particularly limited, but specific structures include those represented by the following formula (3).

With such a structure, the adhesive properties can be controlled by components other than the silicone resin by adjusting the addition amount, and the performance can be brought out while being compatible with the base gum. Twice

R ⁴ , R ⁵ , and R ⁶ are monovalent hydrocarbon groups having 1 to 5 carbon atoms, which may be the same or different from each other. Specific examples of the monovalent hydrocarbon group include an alkyl group such as a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group and a pentyl group, and further, a bond is attached to a carbon atom of these groups. A part or all of the hydrogen atom may be substituted with a halogen atom or another group, and a trifluoromethyl group, a 3,3,3-trifluoropropyl group and the like are exemplified. As the monovalent hydrocarbon group, a saturated aliphatic group is preferable, and a methyl group is particularly preferable.

In the formula, m and n are integers of 1 or more, 1 ≦ m ≦ 20, 1 ≦ n ≦ 20, preferably 2 ≦ m ≦ 15, 2 ≦ n ≦ 15, and more preferably 2 ≦ m ≦. 10, 2 ≦ n ≦ 10.

The hydroxyl value of the component (E) may be 10 to 300 mgOH / g, preferably 15 to 280 mgOH / g, and more preferably 20 to 250 mgOH / g. When it is 10 mgOH / g or more, appropriate adhesive properties are obtained, and when it is 300 mgOH / g or less, it is sufficiently compatible with the base silicone pressure-sensitive adhesive composition.

The content of the component (E) is 0.1 to 3 parts by mass, preferably 0.2 to 2.8 parts by mass, more preferably with respect to the total amount of the components (A) to (C). Is 0.3 to 2.5 parts by mass. If it is less than 0.1 parts by mass, the adhesive properties may not be sufficiently changed, and if it is more than 3 parts by mass, it functions as a silicone adhesive, specifically, heat resistance, etc. May damage.

[(F) component]
The component (F) is a control agent, which causes an addition reaction to start before heat curing when the silicone pressure-sensitive adhesive composition is prepared or applied to a base material, causing the treatment liquid to thicken or gel. It is added to prevent it from occurring. The control agent is coordinated to a platinum group metal which is an addition reaction catalyst to suppress the addition reaction, and when it is heat-cured, the coordination is deviated and catalytic activity is exhibited. Any of the controls conventionally used in the addition reaction curable silicone composition can be used. Specific examples include 3-methyl-1-butyne-3-ol, 3-methyl-1-pentyne-3-ol, 3,5-dimethyl-1-hexin-3-ol, 1-ethynylcyclohexanol, 3 -Methyl-3-trimethylsiloxy-1-butyne, 3-methyl-3-trimethylsiloxy-1-pentyne, 3,5-dimethyl-3-trimethylsiloxy-1-hexyne, 1-ethynyl-1-trimethylsiloxycyclohexane, Bis (2,2-dimethyl-3-butynoxy) dimethylsilane, 1,3,5,7-tetramethyl-1,3,5,7-tetravinylcyclotetrasiloxane, 1,1,3,3-tetramethyl -1,3-Divinyldisiloxane, maleic acid ester, adipic acid ester and the like can be mentioned.

The content of the component (F) may be 0.01 to 5 parts by mass, preferably 0.02 to 4 parts by mass, and more preferably 0, based on the total amount of the components (A) to (C). It is .03 to 3 parts by mass. If it is 0.01 part by mass or more, a sufficient pot life can be obtained, and if it is 5 parts by mass or less, the controllability is not too strong and the reactivity does not deteriorate.

[Organic solvent]
If all of the above components are mixed, the viscosity may increase and handling may become difficult, so a solvent may be optionally added for dilution. Examples of the solvent include aromatic hydrocarbon solvents such as toluene and xylene, aliphatic hydrocarbon solvents such as hexane, heptane, octane, isooctane, decane, cyclohexane, methylcyclohexane and isoparaffin, industrial gasoline and petroleum benzine. Carbohydrate-based solvents such as solvent naphtha, acetone, methyl ethyl ketone, 2-pentanone, 3-pentanone, 2-hexanone, 2-heptanone, 4-heptanone, methylisobutylketone, diisobutylketone, acetonylacetone, cyclohexanone and other ketones. Solvents, ester solvents such as ethyl acetate, propyl acetate, isopropyl acetate, butyl acetate, isobutyl acetate, ethers such as diethyl ether, dipropyl ether, diisopropyl ether, dibutyl ether, 1,2-dimethoxyethane, 1,4 dioxane Solvents with esters and ether moieties such as based solvents, 2-methoxyethyl acetylate, 2-ethoxyethyl acetylate, propylene glycol monomethyl ether acetylate, 2-butoxyethyl acetylate, hexamethyldisiloxane, octamethyltrisiloxane, etc. , Octamethylcyclotetrasiloxane, Decamethylcyclopentasiloxane, Tris (trimethylsiloxy) methylsilane, Tetrax (trimethylsiloxy) silane, and other siloxane-based solvents, or mixed solvents thereof.

[How to use silicone adhesive composition]
In general, the silicone pressure-sensitive adhesive composition is often not mixed with a catalyst, but in the present invention, the catalyst is uniformly mixed and used before actual use.

Paper, plastic film, glass, and metal are selected as the base material on which the silicone pressure-sensitive adhesive composition is applied. Examples of the paper include high-quality paper, coated paper, art paper, glassin paper, polyethylene laminated paper, kraft paper and the like. Plastic films include polyethylene film, polypropylene film, polyester film, polyimide film, polyvinyl chloride film, polyvinylidene chloride film, polyvinyl alcohol film, polycarbonate film, polytetrafluoroethylene film, polystyrene film, ethylene-vinyl acetate copolymer. Examples thereof include films, ethylene-vinyl alcohol copolymer films, triacetyl cellulose films, polyether ether ketone films, and polyphenylene sulfide films. The thickness and type of glass are not particularly limited, and may be chemically strengthened. It can also be applied to glass fibers, and the glass fibers can be used alone or in combination with other resins. Examples of the metal include aluminum foil, copper foil, gold foil, silver foil, nickel foil and the like. Among these base materials, the silicone pressure-sensitive adhesive composition is often used using a plastic film as a base material.

The coating method may be a known coating method, for example, comma coater, lip coater, roll coater, die coater, knife coater, blade coater, rod coater, kiss coater, gravure coater, screen coating, etc. Immersion coating, cast coating and the like can be mentioned.

The amount of coating is not particularly limited, but can be 0.1 to 300 μm, preferably 0.5 to 200 μm.

The curing conditions may be 80 to 150 ° C. for 20 seconds to 10 minutes, but this is not the case.

[Adhesive articles]
In this way, an adhesive article having the cured product of the silicone adhesive composition as described above on at least one side of the base material can be produced.

Hereinafter, the present invention will be specifically described with reference to Examples and Comparative Examples, but the present invention is not limited thereto. In the following, Me represents a methyl group and Vi represents a vinyl group.

[Example 1]
35 parts by mass of polysiloxane (a-1) represented by the following average composition formula (A-1) as a component (A).

_{(B) Methyl containing 1/2} unit of _{Me 3} SiO _{and 4/2} units of SiO as a component, and having a molar ratio of _{(Me 3} SiO _1/2 unit) / (SiO _{4/2 unit) of 0.85.} An amount of 65 parts by mass of a 60% by mass toluene solution of polysiloxane (b-1) as a non-volatile content.
0.35 parts by mass of methylhydrogenpolysiloxane (c-1) represented by the following average composition formula (C-1) as a component (C).

0.5 parts by mass of a thermoplastic resin (e-1) (hydroxyl value: 54 mgOH / g) represented by the following formula (E-1) as a component (E).

0.25 parts by mass of ethynylcyclohexanol as a component (F),
0.5 mass by mass of a toluene solution (d-1) containing 0.5 mass% of the platinum content of the 1,3-divinyl-1,1,3,3-tetramethyldisiloxane platinum (0) complex as a component (D). Department,
Each was added to prepare a silicone pressure-sensitive adhesive composition (the Si—H group in the component (C) was 10.5 times the molar ratio of the vinyl group in the composition).
Using this composition, the adhesive strength and ball tack were evaluated as described below.

[Comparative Example 1]
A silicone pressure-sensitive adhesive composition containing no component (E) was prepared with respect to the composition of Example 1, and the adhesive strength and ball tack were evaluated using this composition.

[Comparative Example 2]
A silicone pressure-sensitive adhesive composition was prepared by adding the same amount of the component (B) instead of the component (E) to the composition of Example 1, and the adhesive strength and ball tack were evaluated using this composition. bottom.

[Example 2]
A silicone pressure-sensitive adhesive composition was prepared in the same manner as in Example 1 except that the amount of the component (E) added was 1.0 part by mass, and the adhesive strength and ball tack were evaluated using this composition.

[Comparative Example 3]
A silicone pressure-sensitive adhesive composition was prepared by adding the same amount of the component (B) instead of the component (E) to the composition of Example 2, and the adhesive strength and ball tack were evaluated using this composition. bottom.

[Example 3]
A silicone pressure-sensitive adhesive composition was prepared in the same manner as in Example 1 except that the amount of the component (E) added was 1.5 parts by mass, and the adhesive strength and ball tack were evaluated using this composition.

[Comparative Example 4]
A silicone pressure-sensitive adhesive composition was prepared by adding the same amount of the component (B) instead of the component (E) to the composition of Example 3, and the adhesive strength and ball tack were evaluated using this composition. bottom.

[Example 4]
A silicone pressure-sensitive adhesive composition was prepared in the same manner as in Example 1 except that the amount of the component (E) added was 2.0 parts by mass, and the adhesive strength and ball tack were evaluated using this composition.

[Comparative Example 5]
A silicone pressure-sensitive adhesive composition was prepared by adding the same amount of the component (B) instead of the component (E) to the composition of Example 4, and the adhesive strength and ball tack were evaluated using this composition. bottom.

[Comparative Example 6]
A silicone pressure-sensitive adhesive composition was prepared by further adding 4.0 parts by mass of the component (B) to the composition of Comparative Example 1, and the adhesive strength and ball tack were evaluated using this composition.

[Example 5]
Silicone in the same manner as in Example 1 except that the component (E) is 1.0 part by mass of the thermoplastic resin (e-2) (hydroxyl value: 163 mgOH / g) represented by the following formula (E-2). A pressure-sensitive adhesive composition was prepared, and the pressure-sensitive adhesive strength and ball tack were evaluated using this composition.

[Example 6]
The amount of the component (a-1) of the component (A) is 50 parts by mass, the amount of the component (b-1) of the component (B) is 50 parts by mass, and the amount of the component (c-1) of the component (C) is 0.50. A silicone pressure-sensitive adhesive composition was prepared in the same manner as in Example 2 except that it was made by mass, and the adhesive strength and ball tack were evaluated using this composition (the Si—H group in the component (C) has a composition. 10.5 times the molar ratio of vinyl groups in the product).

[Comparative Example 7]
A silicone pressure-sensitive adhesive composition containing no component (E) was prepared with respect to the composition of Example 6, and the adhesive strength and ball tack were evaluated using this composition.

[Example 7]
Instead of the component (a-1) of the component (A), 50 parts by mass of the polysiloxane (a-2) represented by the following formula (A-2) is used.

The silicone pressure-sensitive adhesive composition is the same as in Example 2 except that the amount of the component (b-1) of the component (B) is 50 parts by mass and the amount of the component (c-1) of the component (C) is 0.37 parts by mass. A product was prepared, and the adhesive strength and ball tack were evaluated using this composition (the Si—H group in the component (C) was 5.6 times the molar ratio of the vinyl group in the composition).

[Comparative Example 8]
A silicone pressure-sensitive adhesive composition containing no component (E) was prepared with respect to the composition of Example 7, and the adhesive strength and ball tack were evaluated using this composition.

[Example 8]
_{(B) Contains} _{Me 3} SiO _1/2 unit and SiO 4/2 unit instead of component (b-1), and has a molar ratio of (Me ₃ SiO _1/2 unit) / (SiO _{4/2 unit).} A 60% by mass toluene solution of methylpolysiloxane (b-2) having a value of 0.75 is 50 parts by mass as a non-volatile content, and the amount of (c-1) of the component (C) is 0.50 parts by mass. A silicone pressure-sensitive adhesive composition was prepared in the same manner as in Comparative Example 7 except that 1.0 part by mass of a thermoplastic resin (e-1) (hydroxyl value: 54 mgOH / g) was added as a component (E), and this composition was prepared. Was used to evaluate the adhesive strength and ball tack.

[Comparative Example 9]
A silicone pressure-sensitive adhesive composition containing no component (E) was prepared with respect to the composition of Example 8, and the adhesive strength and ball tack were evaluated using this composition.

[Adhesive force]
The silicone pressure-sensitive adhesive composition solution is applied to a PET film having a thickness of 23 μm and a width of 25 mm using an applicator so that the thickness after curing is 30 μm, and then heated and cured at 130 ° C./1 minute to adhere. A tape was made. This adhesive tape was attached to a glass plate and crimped by reciprocating a roller covered with a rubber layer weighing 2 kg twice. The glass plate to which the adhesive tape is attached is placed in a constant temperature bath where constant humidity and temperature are applied for a predetermined number of days, then taken out, and the tape is peeled off from the glass plate at an angle of 180 ° at a speed of 300 mm / min using a tensile tester. The force required for this (N / 25 mm) was measured.

[Ball tack]
The silicone pressure-sensitive adhesive composition solution is applied to a PET film having a thickness of 23 μm and a width of 25 mm using an applicator so that the thickness after curing is 30 μm, and then heated and cured at 130 ° C./1 minute to adhere. A tape was made. The tape was placed on a slope with an inclination angle of 30 ° with the adhesive surface facing up, and a hard sphere was rolled from a run-up distance of 10 cm and evaluated by the maximum value of the hard sphere that stopped within the range of the adhesive layer. The size of the ball is 32 for a ball having a diameter of 1 inch and 1 for a ball having a diameter of 1/32 inch, and the larger the value, the larger the hard ball can be stopped, that is, the tack value is higher.

The results of Examples 1 to 8 and Comparative Examples 1 to 9 are also shown in Table 1.

In Example 1 and Comparative Example 1, it was found that the adhesive strength was increased by the addition of the component (E), and in Comparative Example 2, the same amount of the component (B) as the component (E) was added and blended. However, the increase in adhesive strength does not reach that of Example 1. Similarly, in Examples 2 to 4 and Comparative Examples 3 to 5, the adhesive strength when the amount of the component (E) added is increased, and the case where the same amount of the component (B) is added instead of the component (E). Comparing with the adhesive strength of, it can be seen that the adhesive strength is higher when the component (E) is blended. In Comparative Example 6, the component (B) was further added and blended so as to have an adhesive strength of about Examples 2 and 3, but the tack value was low. From this, it can be seen that the addition of the component (E) has made it possible to control the adhesive properties, that is, to achieve both high adhesive strength and high ball tack, which was difficult to achieve with the conventional silicone adhesive composition.

In Example 5, the component (E) having a different structure is added, but an increase in adhesive strength can be confirmed as in the other examples. In Examples 6 to 8 and Comparative Examples 7 to 9, the composition of the base silicone pressure-sensitive adhesive composition was changed, but in any case, an increase in adhesive strength due to the addition of the component (E) was confirmed.

As described above, according to the present invention, it is possible to obtain a silicone pressure-sensitive adhesive composition having both high adhesive strength and high tack, which has been difficult until now.

The present invention is not limited to the above embodiment. The above-described embodiment is an example, and any object having substantially the same configuration as the technical idea described in the claims of the present invention and exhibiting the same effect and effect is the present invention. Is included in the technical scope of.

Claims

Silicone pressure-sensitive adhesive composition
(A) Organopolysiloxane represented by the average composition formula (1), which has two or more alkenyl group-containing organic groups in one molecule and contains 0.0002 to 0.05 mol of alkenyl groups in 100 g. : 60 to 30 parts by mass,

(R 1 is a monovalent hydrocarbon group having 1 to 10 carbon atoms, which may be the same or different, and two or more of R 1 contain an alkenyl group-containing organic group having 2 to 10 carbon atoms. An integer of 2 or more, b is an integer of 1 or more, c and d are integers of 0 or more, and 50 ≦ a + b + c + d ≦ 15000.)
(B) Includes R 2 3 SiO 1/2 unit and SiO 4/2 unit, and (R 2 3 SiO 1/2 unit) / (SiO 4/2 unit) is 0.6 to 1.0 in molar ratio. A polyorganosiloxane (R 2 represents a monovalent hydrocarbon group having 1 to 10 carbon atoms or an alkenyl group having 2 to 6 carbon atoms, each independently having no aliphatic unsaturated bond): 40 to 70 parts by mass. ,
(C) Polyorganohydrogensiloxane represented by the following average composition formula (2) and having 3 or more Si—H groups in one molecule: Si—H groups are molar relative to the alkenyl groups in the composition. Amount of 0.2 to 20 in ratio,
R 3 e H f SiO (4-ef) / 2 Average composition formula (2)
(R 3 represents an unsubstituted or substituted monovalent hydrocarbon group having 1 to 10 carbon atoms excluding the aliphatic unsaturated group, e> 0, f> 0, and 0 <e + f ≦ 3).
(D) Platinum group metal-based catalyst for hydrosilylating and adding the alkenyl group in the composition and the Si—H group of the component (C) to cure: the total amount of the components (A) to (C) On the other hand, the amount of metal is 1 to 500 ppm,
(E) Silicon-free thermoplastic resin: 0.1 to 3 parts by mass with respect to the total amount of the components (A) to (C).
A silicone pressure-sensitive adhesive composition comprising.
The silicone pressure-sensitive adhesive composition according to claim 1, further comprising (F) a control agent in an amount of 0.01 to 5 parts by mass with respect to the total amount of the components (A) to (C).
The silicone pressure-sensitive adhesive composition according to claim 1 or 2, wherein the component (E) is represented by the following formula (3).

(R 4 , R 5 , and R 6 are monovalent hydrocarbon groups having 1 to 5 carbon atoms, which may be the same or different, respectively, and m and n are integers of 1 or more, and 1 ≦ m ≦ 20, 1 ≦. n ≦ 20.)
The silicone pressure-sensitive adhesive composition according to any one of claims 1 to 3, wherein the hydroxyl value of the component (E) is 10 to 300 mgOH / g.
An adhesive article characterized by having a cured product of the silicone pressure-sensitive adhesive composition according to any one of claims 1 to 4 on one side or both sides of a base material.