CN115066476A

CN115066476A - Silicone adhesive composition

Info

Publication number: CN115066476A
Application number: CN202080095822.6A
Authority: CN
Inventors: 土田理
Original assignee: Shin Etsu Chemical Co Ltd
Current assignee: Shin Etsu Chemical Co Ltd
Priority date: 2020-02-25
Filing date: 2020-12-10
Publication date: 2022-09-16
Also published as: KR20220146433A; JP2021134244A; JP7321954B2; WO2021171734A1

Abstract

The present invention is a silicone adhesive composition comprising: (A) an organopolysiloxane having two or more alkenyl-containing organic groups in one molecule and containing 0.0002 to 0.05 mol of alkenyl groups in 100 g; (B) containing R ² ₃ SiO _1/2 Unit andSiO _4/2 units and in terms of mole ratio (R) ² ₃ SiO _1/2 Unit)/(SiO _4/2 Unit) 0.6 to 1.0 of polyorganosiloxane; (C) r ³ _e H _f SiO _{(4‑e‑f)/2} A polyorganohydrogensiloxane having three or more Si-H groups in one molecule; (D) a platinum group metal-based catalyst for hydrosilylation addition of an alkenyl group in the composition and the Si — H group of the component (C) to cure the composition; (E) a silicone-free thermoplastic resin. Thus, a silicone adhesive composition is provided which has both high adhesion and high tackiness while controlling the adhesion properties by adding components other than silicone resin.

Description

Silicone adhesive composition

Technical Field

The invention relates to an organic silicon adhesive with a novel composition.

Background

The adhesive is one of adhesives, and is often used in the form of an adhesive tape or an adhesive label obtained by coating an adhesive on a substrate and curing the adhesive, and the adhesive tape is a typical article among articles using an adhesive in general. These items are used in a variety of applications, such as labels for identifying items, for packaging goods, or for connecting multiple items, etc.

There are several types of base materials for constituting the adhesive, and they are roughly classified into rubbers, acrylics, silicones, and the like. Rubber adhesives are common base materials, have low prices, and are used in products such as general-purpose tapes. Acrylic adhesives use polyacrylate as a substrate, and are superior to rubbers in chemical properties and the like, and therefore are more suitable for high-functional adhesive products than rubbers. The silicone adhesive is composed of a silicone raw rubber (gum) and a silicone resin having high viscosity, and has various excellent characteristics because the main chain has a plurality of siloxane bonds, and specifically, heat resistance, cold resistance, weather resistance, chemical resistance, electrical insulation, and the like can be mentioned.

The silicone adhesive is used for industrial high-performance tapes such as heat-resistant tapes, masking tapes for engineering, and mica tapes having flame retardancy, because of the excellent properties described above, and is used in cases where the properties can be exhibited even under severe use conditions.

As described above, the main components of the silicone adhesive are gum and silicone resin, but the adhesion characteristics can be controlled by changing the blend of these two components (patent documents 1 to 3). Gums are base polymers which are soft and exhibit easy wetting properties on the surface, and silicone resins are used as tackifiers, which function to impart tackiness by being blended in the base polymers. Although the adhesion of the silicone adhesive composition can be certainly improved by adding the silicone resin, the increase in adhesion by adding the silicone resin is limited at present, and the characteristics of the adhesive obtained by merely changing the blend are limited. However, it is difficult to control the tack characteristics simply by ingredients other than the silicone resin, and it is difficult to perform compatibility with the base gum.

Documents of the prior art

Patent document

Patent document 1: japanese patent No. 5117713

Patent document 2: japanese patent No. 6091518

Patent document 3: japanese patent No. 6348434

Disclosure of Invention

Technical problem to be solved by the invention

Accordingly, an object of the present invention is to provide a silicone adhesive composition that can control the adhesive properties by adding components other than a silicone resin and that can achieve both high adhesion and high tack (tack).

Means for solving the problems

In order to solve the above-mentioned technical problems, the present invention provides a silicone adhesive composition comprising the following components:

(A) an organopolysiloxane having two or more alkenyl-containing organic groups in one molecule and containing 0.0002 to 0.05 mol of alkenyl groups per 100g, represented by the average compositional formula (1), in an amount of 60 to 30 parts by mass,

[ chemical formula 1]

In the formula (1), R ¹ Is a monovalent hydrocarbon group having 1 to 10 carbon atoms, R is the same or different ¹ Two or more of the organic groups contain an alkenyl group having 2 to 10 carbon atoms. 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 a + b + c + d is not less than 50 and not more than 15000;

(B) containing R ² ₃ SiO _1/2 Units and SiO _4/2 Units and in terms of mole ratio (R) ² ₃ SiO _1/2 Unit)/(SiO _4/2 Unit) 0.6 to 1.0, 40 to 70 parts by mass of a polyorganosiloxane, wherein R is ² Each independently represents a C1-10 monovalent hydrocarbon group or a C2-6 alkenyl group having no aliphatic unsaturated bond;

(C) a polyorganohydrogensiloxane having three or more Si-H groups in one molecule represented by the average compositional formula (2) in an amount such that the Si-H groups are in a molar ratio of 0.2 to 20 with respect to the alkenyl groups in the composition,

R ³ _e H _f SiO _(4-e-f)/2 average composition formula (2)

In the formula (2), R ³ Represents an unsubstituted or substituted monovalent hydrocarbon group having 1 to 10 carbon atoms except for an aliphatic unsaturated group, e > 0, f > 0, and e + f is more than 0 and less than or equal to 3;

(D) a platinum group metal-based catalyst for curing the alkenyl group in the composition and the Si-H group of the component (C) by hydrosilylation addition, the amount of the metal being 1 to 500ppm relative to the total amount of the components (A) to (C);

(E) and (C) a silicon-free thermoplastic resin in an amount of 0.1 to 3 parts by mass based on the total amount of the components (A) to (C).

In such a composition, the adhesion properties can be controlled by adding components other than the silicone resin, and a high adhesion force and a high viscosity can be achieved at the same time.

In the present invention, the composition may further contain (F) a control agent, and the amount of the control agent (F) is 0.01 to 5 parts by mass relative to the total amount of the components (a) to (C).

Such a composition can further improve the effect of the present invention.

In the present invention, the component (E) may be a compound represented by the following formula (3).

[ chemical formula 2]

In the formula (3), R ⁴ 、R ⁵ 、R ⁶ Is a monovalent hydrocarbon group having 1 to 5 carbon atoms, m and n are integers of 1 or more, m is 1 or more and 20 or less, and n is 1 or less and 20 or less.

Such a component can control the tack property by adjusting the amount of addition and utilizing components other than the silicone resin, and can exhibit performance while being compatible with the base gum.

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

Such a component can further improve the effect of the present invention.

Further, the present invention provides an adhesive article having a cured product of the silicone adhesive composition on one or both surfaces of a substrate.

With such a component, an adhesive article having both higher adhesive force and higher adhesive force than before can be obtained.

Effects of the invention

The silicone adhesive composition of the present invention can achieve both higher adhesive force and higher viscosity than conventional ones, and by using the composition, an adhesive article can be obtained that achieves both higher adhesive force and higher viscosity than conventional ones.

Detailed Description

As described above, development of a silicone adhesive composition having both high adhesion and high tackiness has been attempted.

The present inventors have conducted extensive studies to solve the above-mentioned problems, and as a result, have found that a silicone adhesive composition having both high adhesion and high tackiness can be obtained while controlling the tackiness characteristics by adding a silicon-free thermoplastic resin, and have completed the present invention.

That is, the present invention is a silicone adhesive composition characterized by containing the following components:

(A) an organopolysiloxane represented by the average compositional formula (1), having at least two alkenyl-containing organic groups in one molecule and containing 0.0002 to 0.05 mol of alkenyl groups per 100g, in an amount of 60 to 30 parts by mass,

[ chemical formula 3]

In the formula (1), R ¹ Is a monovalent hydrocarbon group having 1 to 10 carbon atoms, which may be the same or different, and at least 2R ¹ An alkenyl-containing organic group having 2 to 10 carbon atoms. 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 a + b + c + d is not less than 50 and not more than 15000;

(C) a polyorganohydrogensiloxane having at least three Si-H groups in one molecule represented by the average compositional formula (2) in an amount such that the Si-H groups are in a molar ratio of 0.2 to 20 with respect to the alkenyl groups in the composition,

R ³ _e H _f SiO _(4-e-f)/2 average composition formula (2)

(D) a platinum group metal-based catalyst for curing the alkenyl group in the composition by hydrosilylation addition to the Si-H group of the component (C), in which the amount of the metal is 1 to 500ppm based on the total amount of the components (A) to (C),

The present invention will be described in detail below, but the present invention is not limited to these contents.

[ (A) component ]

(A) The component (A) is an organopolysiloxane represented by the following average composition formula (1), having at least two alkenyl-containing organic groups in one molecule, and containing 0.0002-0.05 mol of alkenyl groups in 100 g.

[ chemical formula 4]

In the formula (1), R ¹ Optionally, the monovalent hydrocarbon groups are the same or different and each has 1 to 10 carbon atoms, R ¹ At least two of the organic groups contain an alkenyl group having 2 to 10 carbon atoms. 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 a + b + c + d is 50 or more and 15000 or less.

R ¹ Is a monovalent hydrocarbon group having 1 to 10 carbon atoms, wherein 2 or more of the monovalent hydrocarbon groups are alkenyl-containing organic groups having 2 to 10 carbon atoms. R ¹ The number of the alkenyl group-containing organic group having 2 to 10 carbon atoms of (A) is not particularly limited as long as it is 2 or more, and all R's may be ¹ Is an alkenyl-containing organic group having 2 to 10 carbon atoms.

Specific examples of the monovalent hydrocarbon group include alkyl groups such as methyl, ethyl, propyl, and butyl; cycloalkyl groups such as cyclohexyl; examples of the "aryl" group include phenyl and the like, and some or all of the hydrogen atoms bonded to carbon atoms 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. Among the above groups, saturated aliphatic groups or aromatic groups are preferable, and methyl groups and phenyl groups are particularly preferable.

The alkenyl-containing organic group is a group having 2 to 10 carbon atoms, and examples thereof include alkenyl groups such as vinyl, allyl, hexenyl, and octenyl; acryloylalkyl groups and methacryloylalkyl groups such as acryloylpropyl, acryloylmethyl and methacryloylpropyl groups; cycloalkenylalkyl groups such as cyclohexenylethyl; alkenyloxyalkyl such as vinyloxypropyl, and the like. Among these groups, vinyl groups are particularly preferable.

The amount of alkenyl groups contained in the component (A) is 0.0002 to 0.05 mol, preferably 0.0004 to 0.04 mol, and more preferably 0.0005 to 0.03 mol per 100g of organopolysiloxane. When the amount is less than 0.0002 mol, the crosslinking density is decreased, and cohesive failure of the adhesive layer may occur, and when the amount is more than 0.05 mol, the adhesive layer becomes hard, and appropriate adhesive force or tackiness may not be obtained.

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, 50. ltoreq. a + b + c + d. ltoreq.15000, preferably 200. ltoreq. a + b + c + d. ltoreq.12000. When a + b + c + d is less than 50, the crosslinking point becomes too much to slow the reaction, and when a + b + c + d is more than 15000, the viscosity of the composition becomes very high, and thus the workability becomes poor.

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

Examples of the component (a) include, but are not limited to, compounds represented by the following general formula.

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 above formula, R ^1-1 Each being a same or different species of organic group containing an alkenyl group, R ^1-2 Respectively are the same or different monovalent hydrocarbon groups with 1-10 carbon atoms and no aliphatic unsaturated bonds, p is not less than 47, q is not less than 1, wherein when the molecule does not have a substituent (R) ^1-1 R ^1-2 SiO) _q R other than R ^1-1 When q is more than or equal to 2.

As R ^1-1 、R ^1-2 Examples thereof include the above-mentioned groups R ¹ The groups exemplified in (1). In addition, 47. ltoreq. p.ltoreq. 11,998 is preferable, 1. ltoreq. q.ltoreq.1,000 is preferable, and 2. ltoreq. q.ltoreq.800 is more preferable.

The component (a) is more specifically a compound represented by the following general formula, but is not limited thereto. In the following formulae, Me, Vi and Ph represent a methyl group, a vinyl group and a phenyl group, respectively.

[ chemical formula 5]

[ chemical formula 6]

[ chemical formula 7]

[ chemical formula 8]

[ chemical formula 9]

[ (B) component ]

(B) Component (A) contains R ² ₃ SiO _1/2 Unit (R) ² Independently represents a C1-10 monovalent hydrocarbon group or a C2-6 alkenyl group having no aliphatic unsaturated bond) and SiO _4/2 Units and in terms of mole ratio (R) ² ₃ SiO _1/2 Unit)/(SiO _4/2 Unit) of 0.6 to 1.0, preferably 0.65 to 0.9. If the molar ratio is less than 0.6, the adhesive force or tackiness may decrease, and if the molar ratio is more than 1.0, the adhesive force or holding power may decrease.

R ² Each independently represents a C1-10 monovalent hydrocarbon group or C2-6 alkenyl group having no aliphatic unsaturated bond, and R is ² Examples of the monovalent hydrocarbon group having 1 to 10 carbon atoms include alkyl groups such as methyl, ethyl, propyl and butyl groups, and alkyl groups having 2 to 6 carbon atoms are preferable; aryl groups such as phenyl and tolyl, preferably aryl groups having 6 to 10 carbon atoms. Examples of the alkenyl group having 2 to 6 carbon atoms include a vinyl group, an allyl group, and a butenyl group.

Two or more components (B) may be used simultaneously. Further, R may be contained in the component (B) as required ² SiO _3/2 Unit, R ² ₂ SiO _2/2 And (4) units.

The component (B) may be one obtained by condensing a hydrolyzable group present on the surface thereof in the presence of a catalyst. Thus, the effect of improving the adhesive force of the adhesive composition can be expected as long as the reaction is carried out at room temperature to reflux using a basic catalyst and the reaction is neutralized as necessary.

Examples of the basic catalyst include metal hydroxides such as lithium hydroxide, sodium hydroxide, potassium hydroxide, and calcium hydroxide; carbonates such as sodium carbonate and potassium carbonate; bicarbonates such as sodium bicarbonate and potassium bicarbonate; metal alkoxides such as sodium methoxide and potassium butoxide; organic metals such as butyl lithium; potassium silanolate; and nitrogen compounds such as ammonia, ammonia water, methylamine, trimethylamine, and triethylamine, and the like, preferably ammonia or ammonia water. The condensation reaction may be carried out at a temperature ranging from room temperature to the reflux temperature of the organic solvent. The reaction time is not particularly limited, and may be 0.5 to 20 hours, preferably 1 to 16 hours.

Further, after the completion of the reaction, a neutralizing agent for neutralizing the basic catalyst may be added as needed. Examples of the neutralizing agent include acidic gases such as hydrogen chloride and carbon dioxide; organic acids such as acetic acid, octanoic acid, and citric acid; and inorganic acids such as hydrochloric acid, sulfuric acid, and phosphoric acid. When ammonia gas, ammonia water or a low-boiling amine compound is used as the basic catalyst, an inert gas such as nitrogen gas may be introduced for distillation.

(A) The amount of the component (A) is 60 to 30 parts by mass, the amount of the component (B) is 40 to 70 parts by mass, and the ratio of the components (A) and (B) is 60/40 to 30/70 by mass, more preferably 55/45 to 35/65 by mass. When the total of the components (a) and (B) is 100, the compatibility with the component (E) described later may be poor if the proportion of the component (B) is less than 40, and the heat resistance of the composition may be poor if the proportion of the component (B) is more than 70.

[ (C) ingredient ]

(C) The component (A) is a polyorganohydrogensiloxane having at least three Si-H groups in one molecule represented by the average compositional formula (2).

R ³ _e H _f SiO _(4-e-f)/2 Average composition formula (2)

In the formula (2), R ³ Represents an unsubstituted or substituted monovalent hydrocarbon group having 1 to 10 carbon atoms except for an 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 an aliphatic unsaturated group. Specifically, examples thereof include alkyl groups such as methyl, ethyl, propyl and butyl; cycloalkyl groups such as cyclohexyl; aryl groups such as phenyl, and the like, and further, some or all of the hydrogen atoms bonded to carbon atoms of these groups may be substituted with halogen atoms or other groups, and trifluoromethyl, 33-trifluoropropyl, and the like. The monovalent hydrocarbon group is preferably a saturated aliphatic group or aromatic group, and particularly preferably a methyl group or a phenyl group.

In the average composition formula (2), e and f are numbers satisfying e > 0, f > 0 and 0 < e + f.ltoreq.3, and preferably numbers satisfying e > 0, f > 0 and 0 < e + f < 3.

(C) The component (b) may be a compound represented by the following general formula (4), but is not limited thereto.

R ⁷ ₃ Si-O-(SiR ⁸ ₂ -O) _r -(SiR ⁹ H-O) _s -O-SiR ¹⁰ ₃ General formula (4)

In the general formula (4), R ⁷ 、R ¹⁰ Each represents a monovalent hydrocarbon group having 1 to 10 carbon atoms or a hydrogen atom other than an aliphatic unsaturated group, R ⁸ 、R ⁹ Each represents a monovalent hydrocarbon group having 1 to 10 carbon atoms excluding an aliphatic unsaturated group, r is 0. ltoreq. r.ltoreq.100, and s is 3. ltoreq. s.ltoreq.80.

R ⁸ 、R ⁹ Each represents a monovalent hydrocarbon group having 1 to 10 carbon atoms other than the aliphatic unsaturated group, and examples thereof include alkyl groups such as methyl, ethyl, propyl, and butyl; cycloalkyl groups such as cyclohexyl; aryl groups such as phenyl and the like. Further, in these groups, some or all of hydrogen atoms bonded to carbon atoms may be substituted with a halogen atom or other groups, and examples thereof include a trifluoromethyl group, a 3,3, 3-trifluoropropyl group and the like. As R ⁸ 、R ⁹ Saturated aliphatic groups or aromatic groups are preferable, and methyl groups or phenyl groups are particularly preferable.

R ⁷ 、R ¹⁰ Each is a monovalent hydrocarbon group having 1 to 10 carbon atoms or a hydrogen atom other than the aliphatic unsaturated group. As R ⁷ 、R ¹⁰ The monovalent hydrocarbon group having 1 to 10 carbon atoms is exemplified by the same groups as those described above, r is 0. ltoreq. r.ltoreq.100, preferably 0. ltoreq. r.ltoreq.80 or 0 < r.ltoreq.80, s is 3. ltoreq. s.ltoreq.80, preferably 4. ltoreq. s.ltoreq.70.

The amount of the component (C) is preferably 0.2 to 20, particularly preferably 0.5 to 15, in terms of the molar ratio of the Si-H groups in the component (C) to the alkenyl groups in the composition. When the crosslinking density is less than 0.2, the cohesive force and holding force may be low. If the amount is more than 20, the crosslinking density increases, and appropriate adhesive force and tackiness may not be obtained.

(C) The component (b) is usually produced by ring-opening polymerization of a cyclic low-molecular siloxane such as octamethylcyclotetrasiloxane and a siloxane having Si — H such as tetramethylcyclotetrasiloxane using an acid catalyst, but since the cyclic low-molecular siloxane is contained as a raw material after the polymerization, it is preferable to use a compound obtained by distilling off the cyclic low-molecular siloxane while passing an inert gas into a reaction product under heating and reduced pressure.

Examples of the general formula representing the specific structure of component (C) include, but are not limited to, chemical formulas represented by the following general formulae. In addition, Me in the following general formula represents a methyl group.

[ chemical formula 10]

[ (D) component ]

(D) The component (C) is a platinum group metal-based catalyst for curing by hydrosilylation addition of the alkenyl group in the composition and the Si — H group in the component (C), and examples of the central metal include platinum, palladium, iridium, rhodium, osmium, ruthenium, and the like, and platinum is preferable. Examples of the platinum catalyst include chloroplatinic acid, an alcohol solution of chloroplatinic acid, a reactant of chloroplatinic acid and an alcohol, a reactant of chloroplatinic acid and an olefin compound, and a reactant of chloroplatinic acid and a vinyl group-containing siloxane.

The content of the component (D) is preferably 1 to 500ppm, more preferably 2 to 450ppm, in terms of mass, of the metal relative to the total amount of the components (A), (B) and (C). If the amount is less than 1ppm, the reaction is retarded and curing is insufficient, and thus various properties such as adhesive force and holding force may not be exhibited. If the amount exceeds 500ppm, the cured product may have poor flexibility.

[ (E) ingredient ]

(E) The component is a silicon-free thermoplastic resin. The thermoplastic resin is not particularly limited as long as it is a silicon-free thermoplastic resin, and specific examples thereof include those represented by the following formula (3).

[ chemical formula 11]

In the formula (3), R ⁴ 、R ⁵ 、R ⁶ The monovalent hydrocarbon groups have 1 to 5 carbon atoms, m and n are integers of 1 or more, m is 1 or more and 20 or less, and n is 1 or less and 20 or less.

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

R ⁴ 、R ⁵ 、R ⁶ And optionally, the monovalent hydrocarbon groups are the same or different and each has 1 to 5 carbon atoms. Specific examples of the monovalent hydrocarbon group include alkyl groups such as methyl, ethyl, propyl, isopropyl, butyl, and pentyl, and some or all of hydrogen atoms bonded to carbon atoms of these groups may be substituted with halogen atoms or other groups, and examples thereof include trifluoromethyl and 3,3, 3-trifluoropropyl. The monovalent hydrocarbon group is preferably a saturated aliphatic group, and particularly preferably a methyl group.

Wherein m and n are integers of 1 or more, 1. ltoreq. m.ltoreq.20, 1. ltoreq. n.ltoreq.20, preferably 2. ltoreq. m.ltoreq.15, 2. ltoreq. n.ltoreq.15, more preferably 2. ltoreq. m.ltoreq.10, 2. ltoreq. n.ltoreq.10.

(E) The hydroxyl value of the component (A) may be 10 to 300mgOH/g, preferably 15 to 280mgOH/g, and more preferably 20 to 250 mgOH/g. When the hydroxyl value is not less than 10mgOH/g, suitable adhesive properties can be obtained, and when the hydroxyl value is not more than 300mgOH/g, the adhesive is sufficiently compatible with the silicone adhesive composition as a base.

The content of the component (E) is 0.1 to 3 parts by mass, preferably 0.2 to 2.8 parts by mass, and more preferably 0.3 to 2.5 parts by mass, relative to the total amount of the components (A) to (C). If the amount is less than 0.1 parts by mass, the adhesive properties may not be sufficiently changed, and if the amount is more than 3 parts by mass, the function as a silicone adhesive may be adversely impaired, specifically, the heat resistance may be impaired.

[ (F) ingredient ]

(F) The component (A) is a control agent which is added for preventing the thickening or gelling of the treatment liquid by inducing an addition reaction before heat curing when the silicone adhesive composition is prepared or applied to a substrate. The control agent inhibits addition reaction by coordinating with a platinum group metal as an addition reaction catalyst, and exhibits catalytic activity by breaking the coordination when heat curing is performed thereon. The control agents conventionally used in addition reaction-curable silicone compositions can be used. Specific examples thereof include 3-methyl-1-butyn-3-ol, 3-methyl-1-pentyn-3-ol, 3, 5-dimethyl-1-hexyn-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-butynyloxy) dimethylsilane, 1,3,5, 7-tetramethyl-1, 3,5, 7-tetravinylcyclotetrasiloxane, 1,3, 3-tetramethyl-1, 3-divinyldisiloxane, maleate, adipate, and the like.

The content of component (F) may be 0.01 to 5 parts by mass, preferably 0.02 to 4 parts by mass, and more preferably 0.03 to 3 parts by mass, relative to the total amount of components (A) to (C). When the amount is 0.01 parts by mass or more, a sufficient pot life (pot life) can be obtained, and when the amount is 5 parts by mass or less, reactivity is not deteriorated due to too strong controllability.

[ organic solvent ]

When all the components are mixed, the viscosity may be increased to make handling difficult, and therefore, 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 (isoparaffine); hydrocarbon solvents such as industrial gasoline, petroleum ether, solvent naphtha (solvent naphtha); ketone solvents such as acetone, methyl ethyl ketone, 2-pentanone, 3-pentanone, 2-hexanone, 2-heptanone, 4-heptanone, methyl isobutyl ketone, diisobutyl ketone, diacetone, and cyclohexanone; ester solvents such as ethyl acetate, propyl acetate, isopropyl acetate, butyl acetate, isobutyl acetate, and the like; ether solvents such as diethyl ether, dipropyl ether, diisopropyl ether, dibutyl ether, 1, 2-dimethoxyethane, and 1, 4-dioxane; solvents having an ester moiety and an ether moiety, such as ethyl 2-methoxyacetate, ethyl 2-ethoxyacetate, propylene glycol monomethyl ether acetate, and ethyl 2-butoxyacetate; siloxane-based solvents such as hexamethyldisiloxane, octamethyltrisiloxane, octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane, tris (trimethylsiloxy) methylsilane, and tetrakis (trimethylsiloxy) silane; or a mixed solvent of these solvents.

[ method of Using Silicone adhesive composition ]

In general, a catalyst is not mixed with the silicone adhesive composition in many cases, but in the present invention, the catalyst is uniformly mixed and used before actual use.

As the substrate to which the silicone adhesive composition is applied, paper, a plastic film, glass, or metal can be selected. Examples of the paper include coated paper, glassine paper, polyethylene laminated paper, and kraft paper. Examples of the plastic film include a polyethylene film, a polypropylene film, a polyester film, a polyimide film, a polyvinyl chloride film, a polyvinylidene chloride film, a polyvinyl alcohol film, a polycarbonate film, a polytetrafluoroethylene film, a polystyrene film, an ethylene-vinyl acetate copolymer film, an ethylene-vinyl alcohol copolymer film, a triacetyl cellulose film, a polyether ether ketone film, and a polyphenylene sulfide film. The thickness, type, and the like of the glass are not particularly limited, and the glass may be chemically strengthened or the like. Glass fibers can be used as appropriate, and 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, and nickel foil. Among these substrates, the silicone adhesive composition is particularly used mostly as a substrate for a plastic film.

The coating method may be any known coating method, and examples thereof include comma coating, lip coating, roll coating, die coating, blade coating, bar coating, kiss coating, gravure coating, screen coating, dip coating, and cast coating.

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

The curing conditions are not limited thereto, as long as the curing is carried out at 80 to 150 ℃ for 20 seconds to 10 minutes.

[ adhesive article ]

In this way, an adhesive article having a cured product of the silicone adhesive composition on at least one surface of a substrate can be produced.

Examples

The present invention will be specifically described below with reference to examples and comparative examples, but the present invention is not limited to these examples and comparative examples. In addition, Me and Vi below represent methyl and vinyl, respectively.

[ example 1]

A silicone adhesive composition was prepared by adding the following components (in terms of molar ratio, the Si-H group in component (C) was 10.5 times as large as the vinyl group in the composition):

35 parts by mass of a component (A) which is a polysiloxane (a-1) represented by the following average composition formula (A-1),

[ chemical formula 12]

A component (B) containing Me in an amount of 65 parts by mass based on the nonvolatile matter ₃ SiO _1/2 Unit and SiO _4/2 Units and in terms of mole ratio (Me) ₃ SiO _1/2 Unit)/(SiO _4/2 Unit) was 0.85 of a 60 mass% toluene solution of methylpolysiloxane (b-1),

0.35 parts by mass of a component (C) which is methylhydrogenpolysiloxane (C-1) represented by the following average compositional formula (C-1),

[ chemical formula 13]

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

[ chemical formula 14]

0.25 part by mass of a component (F) which is ethynylcyclohexanol,

0.5 part by mass of component (D), which is a platinum component toluene solution (D-1) containing 0.5% by mass of 1, 3-divinyl-1, 1,3, 3-tetramethyldisiloxane platinum (0) complex.

The adhesive force and rolling ball tack were evaluated using the composition in the manner described below.

Comparative example 1

A silicone adhesive composition containing no component (E) relative to the composition of example 1 was prepared, and using this composition, the adhesive force and the rolling ball tackiness were evaluated.

Comparative example 2

A silicone adhesive composition in which the component (B) was added in an amount equivalent to and in place of the component (E) in the composition of example 1 was prepared, and the adhesive force and the rolling ball tack were evaluated using this composition.

[ example 2]

A silicone 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 using this composition, the adhesive force and the rolling ball tackiness were evaluated.

Comparative example 3

A silicone adhesive composition in which the component (B) was added in an amount equivalent to and in place of the component (E) in the composition of example 2 was prepared, and the adhesive force and the rolling ball tack were evaluated using this composition.

[ example 3]

A silicone 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 using this composition, the adhesive force and the rolling ball tackiness were evaluated.

Comparative example 4

A silicone adhesive composition in which the component (B) was added in an amount equivalent to and in place of the component (E) in the composition of example 3 was prepared, and the adhesive force and the rolling ball tack were evaluated using this composition.

[ example 4]

A silicone 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 using this composition, the adhesive force and the rolling ball tackiness were evaluated.

Comparative example 5

A silicone adhesive composition in which the component (B) was added in an amount equivalent to and in place of the component (E) in the composition of example 4 was prepared, and the adhesive force and the rolling ball tack were evaluated using this composition.

Comparative example 6

A silicone adhesive composition in which component (B) was added in an amount of 4.0 parts by mass based on the composition of comparative example 1 was prepared, and the adhesive force and the rolling ball tackiness were evaluated using the composition.

[ example 5]

A silicone adhesive composition was prepared in the same manner as in example 1, except that the component (E) was changed to 1.0 part by mass of the thermoplastic resin (E-2) (hydroxyl value: 163mgOH/g) represented by the following formula (E-2), and using this composition, the adhesive force and the rolling ball tackiness were evaluated.

[ chemical formula 15]

[ example 6]

A silicone adhesive composition was prepared in the same manner as in example 2, except that the amount of component (a-1) was 50 parts by mass, the amount of component (B-1) was 50 parts by mass, and the amount of component (C-1) was 0.50 parts by mass, and using this composition, the adhesive force and the rolling ball tack were evaluated (in terms of molar ratio, the Si-H group in component (C) was 10.5 times the vinyl group in the composition).

Comparative example 7

A silicone adhesive composition containing no component (E) relative to the composition of example 6 was prepared, and using this composition, the adhesive force and the rolling ball tackiness were evaluated.

[ example 7]

A silicone adhesive composition was prepared in the same manner as in example 2 except that 50 parts by mass of polysiloxane (a-2) represented by the following formula (A-2) was used in place of (a-1) of component (A), the amount of (B-1) of component (B) was 50 parts by mass, and the amount of (C-1) of component (C) was 0.37 parts by mass, and using this composition, the adhesive force and the rolling ball tack were evaluated (in terms of molar ratio, the Si-H group in component (C) was 5.6 times the vinyl group in the composition).

[ chemical formula 16]

Comparative example 8

A silicone adhesive composition containing no component (E) relative to the composition of example 7 was prepared, and using this composition, the adhesive force and the rolling ball tackiness were evaluated.

[ example 8]

Except that Me was used in an amount of 50 parts by mass in terms of nonvolatile matter ₃ SiO _1/2 Unit and SiO _4/2 Units and in terms of mole ratio (Me) ₃ SiO _1/2 Unit)/(SiO _4/2 Unit) a 60 mass% toluene solution of methylpolysiloxane (B-2) of 0.75 instead of component (B-1) of component (B), the amount of component (C-1) of component (C) was made 0.50 parts by mass, and 1.0 part by mass of thermoplastic resin (E-1) (hydroxyl value: 54mgOH/g) was prepared in the same manner as in comparative example 7, and using this composition, the adhesive force and the rolling ball tackiness were evaluated.

Comparative example 9

A silicone adhesive composition containing no component (E) relative to the composition of the example 8 was prepared, and using this composition, the adhesive force and the rolling ball tackiness were evaluated.

[ adhesion force ]

The silicone adhesive composition solution was coated on a PET film having a thickness of 23 μm and a width of 25mm using a coater so that the thickness after curing was 30 μm, and then heated and cured under a condition of 130 ℃/1 minute, thereby preparing an adhesive tape. The adhesive tape was adhered to a glass plate, and pressure-bonded by reciprocating twice using a roller having a weight of 2kg and covered with a rubber layer. The glass plate to which the adhesive tape was applied was put in a constant temperature bath in which a certain humidity and temperature were set and taken out after a prescribed number of days, and the force (N/25mm) required to peel the adhesive tape from the glass plate at a speed of 300 mm/min at an angle of 180 ° was measured using a tensile tester.

[ Rolling ball tack ]

The silicone adhesive composition solution was coated on a PET film having a thickness of 23 μm and a width of 25mm using a coater so that the thickness after curing was 30 μm, and then heated and cured under a condition of 130 ℃/1 minute, thereby preparing an adhesive tape. The steel ball was placed on a slope with an inclination angle of 30 ° with the adhesive surface of the tape facing upward, and was rolled from a position with a run-up distance of 10cm, and the maximum value of the steel ball stopped in the range of the adhesive layer was evaluated. The size of the rolling ball is 32 for a steel ball with a diameter of 1 inch and 1 for a steel ball with a diameter of 1/32 inches, and a steel ball with a larger stop value indicates a larger viscosity value.

The results of examples 1 to 8 and comparative examples 1 to 9 are shown together in Table 1.

It is understood from example 1 and comparative example 1 that the adhesion was improved by adding component (E), while in comparative example 2, component (B) was added in an amount equal to that of component (E), but the increase in adhesion was not as great as in example 1. Similarly, in examples 2 to 4 and comparative examples 3 to 5, it was found that the adhesion of the composition containing the component (E) was improved when the adhesion was increased by the amount of the component (E) compared with the adhesion when the component (E) was replaced by the same amount of the component (B). In comparative example 6, component (B) was further added for the purpose of providing an adhesive force comparable to those of examples 2 and 3, but the value of the adhesive force was lowered. From this, it is found that the addition of the component (E) can control the tack properties, which have been difficult to achieve in silicone adhesive compositions so far, i.e., can achieve both high tack and high rolling ball tack.

In example 5, although the component (E) having a different structure was added, the increase in the adhesive force was confirmed as in the other examples. In examples 6 to 8 and comparative examples 7 to 9, although the composition of the silicone adhesive composition was changed as the base, in any case, it was confirmed that the adhesive force was increased by the addition of the component (E).

Thus, according to the present invention, a silicone adhesive composition having both high adhesion and high viscosity, which has been difficult to obtain, can be obtained.

The present invention is not limited to the above embodiments. The above embodiments are illustrative, and any embodiments having substantially the same composition as the technical idea described in the claims of the present invention and exhibiting the same operational effects are included in the technical scope of the present invention.

Claims

1. A silicone adhesive composition characterized by comprising the following components:

[ chemical formula 1]

In the formula (1), R ¹ Is a monovalent hydrocarbon group having 1 to 10 carbon atoms, R is the same or different ¹ Wherein 2 or more of the alkenyl-containing organic groups have 2 to 10 carbon atoms, 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. ltoreq. a + b + c + d. ltoreq.15000;

(B) containing R ² ₃ SiO _1/2 Units and SiO _4/2 Units and in terms of mole ratio (R) ² ₃ SiO _1/2 Unit)/(SiO _4/2 Unit) 0.6 to 1.0, 40 to 70 parts by mass of a polyorganosiloxane, R ² Each independently represents a C1-10 monovalent hydrocarbon group or a C2-6 alkenyl group having no aliphatic unsaturated bond;

R ³ _e H _f SiO _(4-e-f)/2 average composition formula (2)

(D) a platinum group metal catalyst for curing by hydrosilylation addition of alkenyl groups in the composition and Si-H groups of the component (C), in which the amount of the metal is 1 to 500ppm relative to the total amount of the components (A) to (C);

2. The silicone adhesive composition according to claim 1, further comprising (F) a control agent, wherein the control agent (F) is 0.01 to 5 parts by mass relative to the total amount of the components (A) to (C).

3. The silicone adhesive composition according to claim 1 or 2, wherein the component (E) is a compound represented by the following formula (3),

[ chemical formula 2]

In the formula (3), R ⁴ 、R ⁵ 、R ⁶ Is a monovalent hydrocarbon group having 1 to 5 carbon atoms, m and n are integers of 1 or more, m is 1. ltoreq. m.ltoreq.20, and n is 1. ltoreq. n.ltoreq.20.

4. The silicone 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.

5. An adhesive article characterized by having a cured product of the silicone adhesive composition according to any one of claims 1 to 4 on one or both surfaces of a substrate.