KR20180000693A - Thermosensitive resin, thermosensitive adhesive and thermosensitive adhesive composition - Google Patents

Abstract

The present invention provides a thermosensitive resin having excellent thermal resistance and chemical resistance; and a thermosensitive adhesive and a thermosensitive adhesive composition, comprising the same. According to the present invention, the thermosensitive resin is represented by chemical formula (I), crystallizes at temperatures under a melting point, exhibits flowability at temperatures equal to or greater than the melting point, and is appropriately used as a material for a thermosensitive adhesive and a thermosensitive adhesive composition. In the chemical formula (I): R_1s are identical or different, and represent hydrocarbon groups having 1-10 carbon atoms; R_2 is a group having an alkenyl group; and R_3 represents a polymethylene group having 2-11 carbon atoms.

Description

[0001] THERMOSENSITIVE RESIN, THERMOSENSITIVE ADHESIVE AND THERMOSENSITIVE ADHESIVE COMPOSITION [0002] This invention relates to a thermosensitive resin, a thermosensitive adhesive,

The present invention relates to a thermosensitive resin, a thermosensitive pressure-sensitive adhesive and a thermosensitive pressure-sensitive adhesive composition.

A thermosensitive resin having a thermosensitive property reversibly showing a crystalline state and a flow state in response to a temperature change is known (for example, Patent Documents 1 and 2). Since the thermosensitive resin is often used as a pressure-sensitive adhesive, it is preferable that the thermosensitive resin has excellent heat resistance and chemical resistance.

Japanese Patent Application Laid-Open No. 2001-290138 Japanese Patent Application Laid-Open No. 2008-179744

A problem to be solved by the present invention is to provide a thermosensitive resin having excellent heat resistance and chemical resistance, and a thermosensitive pressure sensitive adhesive and a thermosensitive pressure sensitive adhesive composition containing the same.

Means for Solving the Problems As a result of intensive studies to solve the above problems, the present inventors have found a solution having the following constitution, and have completed the present invention.

(1) A thermosensitive resin represented by the following formula (I), which crystallizes at a temperature lower than the melting point and exhibits fluidity at a temperature higher than the melting point.

In the formula (I), R ₁ is the same or different and represents a hydrocarbon group of 1 to 10 carbon atoms. R ₂ represents a group having an alkenyl group. R ₃ represents a polymethylene group having 2 to 11 carbon atoms. R ₄ represents a mesogen group having a structure represented by the following formula (II). m represents an integer of 2 to 10; n represents an integer of 1 to 100; x represents an integer of 0 to 2,000. y represents an integer of 100 to 2000. and z represents an integer of 2 to 1000.

In formula (II), R ₅ represents hydrogen, an aliphatic hydrocarbon group of 1 to 10 carbon atoms, an aromatic hydrocarbon group of 6 to 18 carbon atoms, an alkoxy group of 1 to 10 carbon atoms, or a cyano group.

(2) The thermosensitive resin according to the above (1), wherein the thermosensitive resin has a structure in which the mesogen group is represented by the following formula (II) 'or (II)' '.

(3) The thermosensitive resin according to the above (1) or (2), wherein the melting point is 0 占 폚 or higher.

(4) A thermosensitive pressure-sensitive adhesive containing the thermosensitive resin according to any one of (1) to (3), wherein the adhesive strength is lowered at a temperature lower than the melting point of the resin.

(5) The thermosensitive adhesive according to (4), wherein the melting point is 0 占 폚 or higher.

(6) The thermosensitive adhesive according to (4) or (5), further comprising a polysiloxane having a Si-H group and a silanol-trimethylsilyl-modified MQ resin.

(7) A thermosensitive pressure-sensitive adhesive sheet comprising the thermosensitive adhesive according to any one of (4) to (6).

(8) A pressure sensitive adhesive tape comprising the pressure sensitive adhesive layer according to any one of (4) to (6) above laminated on at least one side of a substrate.

(9) A thermosensitive pressure-sensitive adhesive composition comprising the thermosensitive resin according to any one of (1) to (3), polysiloxane having Si-H group, silanol-trimethylsilyl-modified MQ resin, and Karstedt catalyst.

(Effects of the Invention)

According to the thermosensitive resin of the present invention, excellent heat resistance and chemical resistance are exhibited. Such a thermosensitive resin is suitably used as a raw material for a thermosensitive pressure-sensitive adhesive and a thermosensitive pressure-sensitive adhesive composition.

<Thermosensitive Resin>

The thermosensitive resin according to one embodiment of the present invention will be described in detail. The thermosensitive resin of the present embodiment has a structure represented by formula (I).

In the formula (I), R ₁ is the same or different and represents a hydrocarbon group of 1 to 10 carbon atoms. The hydrocarbon group having 1 to 10 carbon atoms is not particularly limited and examples thereof include alkyl groups such as methyl group, ethyl group, propyl group, butyl group, pentyl group and hexyl group, alkenyl groups such as vinyl group, allyl group and butenyl group, , An aryl group such as a benzyl group, a phenethyl group, and a tolyl group. The alkyl group and the alkenyl group may have a straight chain structure or may have a branched structure.

In the formula (I), R ₂ represents a group having an alkenyl group. The group having an alkenyl group is a moiety having reactivity in the thermosensitive resin of the present embodiment. R ₂ is preferably a group having an alkenyl group having 2 to 10 carbon atoms. Specific examples of R ₂ include vinyl, allyl, butenyl, pentenyl, hexenyl, heptenyl, octenyl, nonenyl and decenyl.

In the formula (I), R ₃ represents a polymethylene group having 2 to 11 carbon atoms. The side chain moiety including the R ₃ , that is, the side chain moiety derived from the compound represented by the following formula (III) is a moiety having crystallinity in the thermosensitive resin of the present embodiment. The thermosensitive resin of the present embodiment is crystallized by aligning the side chains derived from the compound represented by the following formula (III) in an ordered sequence by molecular force or the like. Specific examples of the polymethylene group having 2 to 11 carbon atoms include a dimethylene group, a trimethylene group, a tetramethylene group, a pentamethylene group, and a hexamethylene group.

In the formula (I), R ₄ represents a mesogen group having a structure represented by the following formula (II). The mesogen group means a rigid and highly oriented group which contributes to the liquid crystalline expression. In formula (II), R ₅ represents hydrogen, an aliphatic hydrocarbon group of 1 to 10 carbon atoms, an aromatic hydrocarbon group of 6 to 18 carbon atoms, an alkoxy group of 1 to 10 carbon atoms, or a cyano group.

Examples of the aliphatic hydrocarbon group having 1 to 10 carbon atoms include a methyl group, an ethyl group, a propyl group, a butyl group, an octyl group and a decyl group. Examples of the aromatic hydrocarbon group having 6 to 18 carbon atoms include a phenyl group, a benzyl group, a biphenyl group, and a terphenyl group. Examples of the alkoxy group having 1 to 10 carbon atoms include a methoxy group, an ethoxy group, a butoxy group, an octyloxy group, a decyloxy group, a diethoxy group, a triethoxy group and a tetraethoxy group. As R _{5, an} n-butyl group or a methoxy group is preferable. The mesogen group having a structure represented by the formula (II) wherein R ₅ is an n-butyl group or a methoxy group is represented by the following formulas (II) 'and (II)'.

In the formula (I), x represents an integer of 0 to 2000, preferably an integer of 0 to 1500, more preferably an integer of 0 to 1000. y represents an integer of 100 to 2,000, preferably an integer of 100 to 1,500, and more preferably an integer of 200 to 1,500. z represents an integer of 2 to 1000, preferably an integer of 2 to 1000, more preferably an integer of 2 to 800.

In the formula (I), m represents an integer of 2 to 10, preferably an integer of 2 to 6, more preferably an integer of 2 to 3. n represents an integer of 1 to 100, preferably an integer of 2 to 40, more preferably an integer of 2 to 10.

The weight average molecular weight of the thermosensitive resin of the present embodiment is not particularly limited. The thermosensitive resin of the present embodiment preferably has a weight average molecular weight of 100,000 or more, more preferably 150,000 or more, preferably 2,000,000 or less, and more preferably 1,500,000 or less. The &quot; weight average molecular weight &quot; is a value obtained by measuring the thermosensitive resin by gel permeation chromatography (GPC) and converting the measured value into polystyrene.

The thermosensitive resin of the present embodiment has a melting point with respect to crystallization. Melting point &quot; means a temperature at which a specific portion of the polymer that has been initially aligned in an orderly arrangement is disordered by a predetermined equilibrium process, and is measured by a differential scanning calorimeter (DSC) under the condition of 10 ° C / min Quot ;. &lt; / RTI &gt; The thermosensitive resin of the present embodiment preferably has a melting point of 0 ° C or higher, more preferably 10 ° C or higher, and preferably has a melting point of 120 ° C or lower, more preferably 100 ° C or lower.

The thermosensitive resin of the present embodiment crystallizes at a temperature lower than the melting point and shows fluidity at the temperature higher than the melting point. That is, the thermosensitive resin of the present embodiment has a thermosensitive property reversibly showing the crystalline state and the flow state in response to the temperature change.

The thermosensitive resin of the present embodiment is a polysiloxane having a siloxane bond in its main chain, as shown by the formula (I). Specifically, the thermosensitive resin of the present embodiment is a polyorganosiloxane having a reactive site R ₂ and a side chain derived from a compound represented by the formula (III) which is a crystalline site and having a silicon skeleton. By such a constitution, excellent heat resistance and chemical resistance are exhibited. That is, since the conventional thermosensitive resin usually has an acrylic skeleton, it is hydrolyzed violently under a chemical environment such as alkali or a high temperature environment of 200 ° C or higher. Therefore, the conventional thermosensitive resin can not be used under the circumstances described above.

On the other hand, the thermosensitive resin of this embodiment has a silicon skeleton as described above. As a result, excellent heat resistance and chemical resistance are exhibited as compared with the conventional thermosensitive resin having an acrylic skeleton. The thermosensitive resin of the present embodiment can be used under a high temperature environment of, for example, 250 캜 or more.

Next, an example of a method of manufacturing the thermosensitive resin of the present embodiment will be described. The thermosensitive resin of the present embodiment can be produced by, for example, obtaining a chain polysiloxane by ring-opening polymerization of cyclic siloxane, and adding a side chain (a compound represented by the above formula (III)) to a siloxane and a mesogen- Derived side chain). Hereinafter, one embodiment of the production method will be described by taking specific compounds as an example.

The cyclic siloxane is not particularly limited as long as it is a compound having a cyclic molecular structure formed by a siloxane bond. In the present embodiment, the compounds represented by the following formulas (IV) and (IV) 'will be described as an example.

(IV), tetramethyltetravinylcyclotetrasiloxane represented by the formula (IV) ', and a chain siloxane represented by the following formula (V) as a terminal endblock, VI) in the presence of a base catalyst.

R ₁ in the formula (V) is the same or different and represents a hydrocarbon group of 1 to 10 carbon atoms, as described above. The hydrocarbon group having 1 to 10 carbon atoms is not particularly limited and examples thereof include alkyl groups such as methyl group, ethyl group, propyl group, butyl group, pentyl group and hexyl group, alkenyl groups such as vinyl group, allyl group and butenyl group, , An aryl group such as a benzyl group, a phenethyl group, and a tolyl group. The alkyl group and the alkenyl group may have a straight chain structure or may have a branched structure. and a represents an integer of 0 to 1000. Examples of the compound represented by the formula (V) include compounds represented by the following formulas (V) 'and (V) As the compound to be shown, for example, "1,1,4,4-tetramethyl-1,1,4,4-tetravinyldisiloxane" manufactured by Tokyo Kasei Kogyo Co., Ltd. or "DMS- (KF-96) manufactured by Shin-Etsu Chemical Co., Ltd., "hexamethyldisiloxane" manufactured by Tokyo Kasei Kogyo Co., Ltd., and the like, And &quot; octamethyltrisiloxane &quot; are commercially available.

In the compound represented by the following formula (VI) used as a base catalyst, b represents an integer of 1 to 8. As the compound represented by the formula (VI), for example, Gelest. &Quot; TETRAMETHYLAMMONIUM SILOXANOLATE &quot;

The base catalyst is not limited to the compound represented by the formula (V), but other base catalysts may be used. Examples of other base catalysts include tetrabutylammonium silanolate, tetramethylphosphonium silanolate, tetrabutylphosphonium silanolate, tetramethylstionium silanolate, tetrabutylstionium silanolate, tetrabutylaryl Silanolates of basic organic compounds such as sodium silanolate, trimethylsulfonium silanolate, triethylsulfonium silanolate and the like, silanolates of strongly basic alkali metal hydroxides such as potassium silanolate, cesium silanolate and the like .

The ring-opening polymerization is carried out by reacting octamethylcyclotetrasiloxane represented by the formula (IV), tetramethyltetravinylcyclotetrasiloxane represented by the formula (IV) ', a terminal sealing agent represented by the formula (V) ) At a temperature of, for example, about 0 to 120 DEG C, preferably about 70 to 120 DEG C for about 0.1 to 48 hours, preferably about 0.5 to 24 hours. The reaction may be carried out in a solvent such as toluene, if necessary.

The mixing ratio of the octamethylcyclotetrasiloxane represented by the formula (IV) and the tetramethyltetravinylcyclotetrasiloxane represented by the formula (IV) 'is not particularly limited. For example, the siloxane represented by the formula (IV) and the siloxane represented by the formula (IV) 'are mixed at a molar ratio of 0: 1 to 5: 1, preferably 0: 1 to 2: 1. The end sealant is preferably added in a proportion of 0.00001 to 30 parts by mass based on 100 parts by mass of the mixture of the siloxane represented by the formula (IV) and the formula (IV) '. The base catalyst is preferably added in a proportion of 0.0000001 to 1 part by mass based on 100 parts by mass of the mixture of the siloxane represented by the formula (IV) and the formula (IV) '. Thus, a chain-like polysiloxane represented by the following formula (VII) is obtained. C in the formula (VII) represents an integer of 0 to 2,000, and d represents an integer of 0 to 3,000. The chain polysiloxane represented by the formula (VII) uses a compound represented by the formula (V) 'as a terminal sealing agent.

Next, the addition reaction will be described. First, a compound generating a mesogen group having a structure represented by the above-mentioned formula (II) and a polysiloxane having Si-H groups at both terminals are reacted in the presence of a Karstedt catalyst represented by the following formula (VII). The obtained reaction product (the compound represented by the above formula (III)) and the chain polysiloxane represented by the formula (VII) are reacted in the presence of a Karstedt catalyst represented by the formula (VIII). The Karstedt catalyst may be a commercially available product, for example, &quot; Platinum (0) -1,3-divinyltetramethyldisiloxane complex &quot;, Gelest. SIP6831.2 &quot;, &quot; SIP6831.2LC &quot; and the like are commercially available.

Examples of the compound capable of generating a mesogen group having a structure represented by the formula (II) include a compound represented by the following formula (IX). In formula (IX), R ₅ is as described above, and a description thereof will be omitted. R ₆ represents an alkenyl group having 2 to 11 carbon atoms. Among the compounds capable of generating a mesogen group having the structure represented by the formula (II), compounds represented by the following formula (IX) 'or (IX)' are preferable.

Examples of the siloxane include a siloxane represented by the following formula (X). R ₁ and n in the formula (X) are as described above, and a description thereof will be omitted. Specific examples of the siloxane represented by the formula (X) include tetramethyldisiloxane represented by the following formula (X) '.

Specifically, the addition reaction is carried out in the following two-step reaction. First, the polysiloxane having a Si-H group at both terminals (formula (X)) is added to a molar ratio of 1 to 20, preferably 4 to 10, And Karstedt catalyst is added at a ratio of, for example, 10 to 100 ppm, preferably 10 to 50 ppm. Thereafter, the reaction is carried out at about 40 to 110 ° C, preferably about 50 to 70 ° C, for about 1 to 48 hours, preferably about 3 to 12 hours. The reaction may be carried out in a solvent such as toluene, if necessary. Thus, a compound represented by the above-mentioned formula (III) is obtained in the first-step reaction.

Next, the obtained compound represented by the formula (III) and the chain polysiloxane represented by the formula (VII) are reacted in the presence of a Karstedt catalyst represented by the formula (VIII). The chain polysiloxane represented by the formula (VII) is added in a molar ratio of, for example, 0.1 to 1, preferably 0.2 to 1, to the molar ratio of the compound represented by the formula (III), and the Karstedt catalyst is, 10 to 100 ppm, preferably 10 to 50 ppm. Thereafter, the reaction is carried out at about 40 to 110 ° C, preferably about 50 to 100 ° C, for about 1 to 48 hours, preferably about 3 to 6 hours. The reaction may be carried out in a solvent such as toluene, if necessary.

The reaction of the second step may be carried out by isolating the compound represented by the formula (III). After the completion of the reaction of the first step, the compound represented by the formula (III) Or by adding a chain-like polysiloxane to be represented.

Thus, when a compound represented by the formula (IX) 'is used as the compound represented by the formula (IX) and tetramethyldisiloxane represented by the formula (X)' is used as the siloxane, (An example of the thermosensitive resin according to the present embodiment) represented by the following formula (XI) can be obtained. X, y and z in the formula (XI) are the same as those described above, and a description thereof will be omitted.

After the reaction, the reactant may be used as a thermosensitive resin as it is, or the reaction product may be purified and used as a thermosensitive resin. As the purification method, there can be mentioned, for example, a method of removing an asymmetric olefin or the like which is an impurity by solvent washing or re-precipitation. The solvent is not particularly limited, and examples thereof include acetone, a mixed solvent of toluene and acetone, and the like. Whether or not the impurities are removed can be confirmed by, for example, GPC or ¹ H-NMR.

&Lt; Temperature Sensitive Adhesive >

Next, the thermosensitive adhesive according to one embodiment of the present invention will be described in detail. The thermosensitive adhesive of the present embodiment contains the thermosensitive resin according to one embodiment described above and the adhesive strength is lowered at a temperature lower than the melting point of the thermosensitive resin. The thermosensitive pressure-sensitive adhesive of the present embodiment contains a thermosensitive resin in which the thermosensitive resin crystallizes at a temperature lower than the melting point and the adhesive force is lowered. Therefore, when the thermosensitive adhesive is peeled off from the adherend, the thermosensitive adhesive is crystallized by cooling the thermosensitive adhesive to a temperature lower than the melting point of the thermosensitive resin, and the adhesive force is lowered. On the other hand, when the thermosensitive adhesive is heated to a temperature higher than the melting point of the thermosensitive resin, the thermosensitive resin exhibits fluidity, thereby restoring the adhesive force. As a result, the thermosensitive adhesive of the present embodiment can be used repeatedly.

The thermosensitive adhesive of the present embodiment preferably includes a polysiloxane having a Si-H group and a silanol-trimethylsilyl-modified MQ resin (hereinafter sometimes simply referred to as &quot; MQ resin &quot;).

The polysiloxane having an Si-H group can be cross-linked with the thermosensitive resin to three-dimensionally form a cohesive force to the thermosensitive resin. As a result, the adhesiveness of the thermosensitive adhesive can be further improved. The polysiloxane having a Si-H group is not particularly limited, and examples thereof include compounds represented by the following formulas (XII) to (XII) ". f in the formula (XII) represents an integer of 0 to 2000 G in the formula (XII) 'represents an integer of 2 to 200. h in the formula (XII) " represents an integer of 0 to 5000, and i represents an integer of 2 to 2000. HMS-013 "," HMS-031 "," HMS-064 "," HMS-071 ", and" HMS-013 " DMS-H31 "," DMS-H41 "(all manufactured by Gelest. Inc.)," HMS-082 "," HMS-151 "," HMS-501 "," DMS-H11 " ) Are commercially available.

The MQ resin functions as a cohesive force component in the thermosensitive adhesive of the present embodiment. The MQ resin has a structure represented by the following formulas (XIII), (XIII) 'and the like, and usually has good compatibility with the above-mentioned thermosensitive resin. MQ resins may be commercially available, for example Gelest. Silmer VQ2012 "," Silmer VQ122XYL "and" Silmer VQ9XYL "manufactured by Siltech Corp. are available on the market such as" SQO-299 "and" VQX-221 "

When the thermosensitive adhesive of the present embodiment contains a polysiloxane having an Si-H group and an MQ resin, the content of each component is not particularly limited. For example, the polysiloxane having an Si-H group is contained in an amount of preferably 0.001 to 1000 parts by mass, more preferably 0.01 to 500 parts by mass, based on 100 parts by mass of the thermosensitive resin. The MQ resin is contained in an amount of preferably 10 to 1000 parts by mass, more preferably 20 to 500 parts by mass, based on 100 parts by mass of the thermosensitive resin.

The thermosensitive adhesive of the present embodiment may be applied directly to an adherend, or may be used in the form of a sheet of a base-less sheet, and the mode of use is not particularly limited. For example, when the thermosensitive adhesive of the present embodiment is used as the thermosensitive adhesive sheet, the thickness of the thermosensitive adhesive sheet is preferably 10 to 500 mu m, more preferably 10 to 200 mu m.

The thermosensitive adhesive of the present embodiment may be used in the form of a tape. When the thermosensitive adhesive of the present embodiment is used as the thermosensitive adhesive tape, the pressure sensitive adhesive layer containing the thermosensitive adhesive of this embodiment is laminated on at least one side of the substrate. The substrate is preferably film-shaped, and the film-like shape includes a sheet-like shape.

Examples of the constituent material of the substrate include polyethylene, polyethylene terephthalate, polyethylene naphthalate, polypropylene, polyester, polyamide, polyimide, polycarbonate, ethylene vinyl acetate copolymer, ethylene ethyl acrylate copolymer, ethylene polypropylene A copolymer, a polyvinyl chloride, and a polyether ether ketone.

The base material may have a single-layer structure or a multi-layer structure. The substrate usually has a thickness of about 5 to 500 mu m. The substrate may be subjected to surface treatment such as corona discharge treatment, plasma treatment, blast treatment, chemical etching treatment, primer treatment or the like for the purpose of improving adhesion to the pressure-sensitive adhesive layer.

The method of laminating the pressure-sensitive adhesive layer on at least one surface of the substrate is not particularly limited. For example, a method of applying a coating liquid prepared by adding a solvent to a thermosensitive pressure-sensitive adhesive on one side or both sides of a substrate with a coater or the like and drying the coating liquid can be mentioned. Examples of the coater include a knife coater, a roll coater, a calendar coater, a comma coater, a gravure coater, and a rod coater.

A Karstedt catalyst for carrying out a crosslinking reaction is usually added to the coating liquid, and a prohibiting agent for suppressing the reaction before coating may be added. As a result, the inhibitor and the Karstedt catalyst form a complex to prevent the crosslinking reaction from occurring in the pressure-sensitive adhesive layer. If the inhibitor is volatilized by heating above the boiling point of the inhibitor, the crosslinking reaction proceeds through the Karstedt catalyst. Examples of the inhibitor include 1-butyne-2-ol, 2-methyl-3-butyne-2-ol, 3,5-dimethyl- Phenylbutynol, 1-ethynyl-1-cyclohexanol, and the like.

The Karstedt catalyst is added to the thermosensitive resin so that the concentration of platinum is preferably in the range of 1 to 1000 ppm. On the other hand, the inhibitor is added in a proportion of preferably 1 to 5 parts by mass based on 100 parts by mass of the thermosensitive resin. The constitution of the coating liquid is the same when the thermosensitive adhesive is applied directly to an adherend or when it is used in the form of a sheet of base-less lease.

The pressure-sensitive adhesive layer preferably has a thickness of 1 to 100 占 퐉, more preferably 5 to 80 占 퐉, and still more preferably 10 to 60 占 퐉. When the pressure-sensitive adhesive layer is laminated on both sides of the substrate, the thickness of the pressure-sensitive adhesive layer may be the same or different, and the composition of the pressure-sensitive adhesive forming the pressure-sensitive adhesive layer may be the same or different.

If a pressure-sensitive adhesive containing the thermosensitive adhesive of the present embodiment is laminated on one side of the substrate, another pressure-sensitive adhesive layer may be laminated on the other side. For example, an adhesive layer containing a pressure-sensitive adhesive may be laminated on the other side. The pressure-sensitive adhesive includes a polymer having adhesiveness. Examples of such a polymer having adhesiveness include natural rubber adhesives, synthetic rubber adhesives, styrene / butadiene latex base adhesives, acrylic adhesives, and the like.

It is preferable to laminate a release film on the surface of the thermosensitive adhesive sheet and the thermosensitive adhesive tape of the present embodiment. As the release film, for example, a film made of polyethylene terephthalate coated on the surface of a releasing agent such as fluorosilicone and the like can be given.

<Temperature Sensitive Adhesive Composition>

Next, the thermosensitive adhesive composition according to one embodiment of the present invention will be described in detail. The thermosensitive pressure-sensitive adhesive of the present embodiment contains a thermosensitive resin according to one embodiment, a polysiloxane having Si-H group, a silanol-trimethylsilyl-modified MQ resin, and a Karstedt catalyst. If necessary, the aforementioned inhibiting agent may be added. Details of each component are as described above, and a description thereof will be omitted.

As described above, the thermosensitive resin according to one embodiment of the present invention has excellent heat resistance and chemical resistance. The use of a thermosensitive pressure-sensitive adhesive containing such a thermosensitive resin is not particularly limited, and is suitably used as a pressure-sensitive adhesive in a field requiring heat resistance and chemical resistance, for example.

The present invention is not limited to the above-described embodiments, and various modifications are possible without departing from the gist of the present invention. For example, in the above-described embodiment, the thermosensitive adhesive containing the thermosensitive resin, the polysiloxane having the Si-H group, and the MQ resin has been described as an example. However, as long as the thermosensitive pressure-sensitive adhesive contains the above-mentioned thermosensitive resin, it is not limited to the composition containing the polysiloxane having the Si-H group and the MQ resin, and may be constituted of a general material used in a so-

(Example)

Hereinafter, the present invention will be described in detail with reference to examples and comparative examples, but the present invention is not limited to these examples.

(Synthesis Example 1: Synthesis of chain-like polysiloxane)

20 g of cyclic siloxane and 5 mg of end sealant were added to a three-necked flask equipped with a stirring blade and a nitrogen introduction tube. Tetramethylcyclotetrasiloxane (manufactured by Tokyo Kasei Kogyo Co., Ltd.) was used as the cyclic siloxane, and hexamethyldisiloxane (manufactured by Tokyo Kasei Kogyo Co., Ltd.) was used as the end sealer. Nitrogen was introduced into the mixture of the cyclic siloxane and the end sealant from a nitrogen introduction tube and subjected to nitrogen bubbling for 30 minutes while stirring. Then, the nitrogen introduction tube was separated from the mixture, and the three-necked flask was placed in an oil bath. 7 mg of "TETRAMETHYLAMMONIUM SILOXANOLATE (manufactured by Tokyo Kasei Kogyo Co., Ltd.)" as a base catalyst was added to a three-necked flask, and the mixture was stirred at 100 ° C for 6 hours. Subsequently, the temperature was raised to 150 ° C to decompose the catalyst, and the mixture was further stirred for 3 hours. After completion of the reaction, the reaction mixture was cooled to room temperature to obtain a chain polysiloxane represented by the formula (VII). From the GPC measurement, the obtained chain polysiloxane had a number average molecular weight of 55,000 and a weight average molecular weight of 137,000. The number average molecular weight and the weight average molecular weight were obtained by measuring the obtained chain polysiloxane with GPC and converting the measured value into polystyrene.

(Synthesis Example 2: Synthesis of liquid crystal molecules (compound generating a mesogen group)

20 g of 4-Allyloxybenzaidehyde (manufactured by Tokyo Kasei Kogyo K.K.), 18.4 g of 4-Butylaniline (manufactured by Tokyo Kasei Kogyo K.K.) and 40 g of ethanol were added to a flask equipped with a stirrer and a cooling tube Was added. The flask was placed in an oil bath and heated to 80 DEG C with stirring using a magnetic stirrer, and the reaction was carried out for 24 hours. Subsequently, the reaction mixture was allowed to stand, cooled to room temperature, purified by recrystallization, and yellow crystals were recovered by suction filtration. The recovered crystals were dried under reduced pressure at 100 ° C for 4 hours to obtain a compound (A) capable of generating a mesogen group represented by the formula (IX) '. From the DSC measurement (10 占 폚 / min), the obtained compound (A) had a melting point of about 69 占 폚 and had a clearing point of about 53 占 폚.

(Synthesis Example 3: Synthesis of liquid crystal molecules (compounds generating mesogenic groups)

20 g of 4-Allyloxybenzaidehyde (manufactured by Tokyo Kasei Kogyo K.K.), 15.2 g of p-Anisidine (manufactured by Tokyo Kasei Kogyo K.K.) and 40 g of toluene were placed in a flask equipped with a stirrer and a cooling tube, Was added. The flask was placed in an oil bath and heated to 100 DEG C with stirring using a magnetic stirrer, and the reaction was carried out for 12 hours. Subsequently, the reaction mixture was allowed to stand, cooled to room temperature, purified by recrystallization, and yellow crystals were recovered by suction filtration. The recovered crystals were dried under reduced pressure at 120 DEG C for 4 hours to obtain a compound (B) that generates a mesogen group represented by the formula (IX) ". From the DSC measurement (10 DEG C / And had a melting point of 112 ° C.

(Synthesis Example 4: Synthesis of mesogen unit)

45.8 g of "tetramethyldisiloxane (manufactured by Tokyo Kasei Kogyo Co., Ltd.)", 10 g of the compound (A) obtained in Synthesis Example 2 and 82 g of dehydrated toluene were added to a three-necked flask equipped with a stirrer and a thermometer . The three-necked flask was placed in an oil bath and heated to 70 캜 while stirring. When the temperature reached 70 占 폚, 10 mg of a 20 mass% toluene solution of "platinum (0) -1,3-divinyltetramethyldisiloxane complex (manufactured by Tokyo Kasei Kogyo Co., Ltd.)" was added. Then, the mixture was stirred at 70 占 폚 for 24 hours. Then, a Dean-Stark apparatus was attached to the three-necked flask, and the unreacted tetramethyldisiloxane was recovered by heating at 100 DEG C for 3 hours. Subsequently, the reaction mixture in the three-necked flask was dropped into ethanol and subjected to precipitation purification. The precipitate was recovered by suction filtration and dried under reduced pressure at 80 캜 to obtain a mesogenic unit (A) 'having one end reactive group represented by the formula (III).

(Synthesis Example 5: Synthesis of mesogen unit)

Except that 50.2 g of "tetramethyldisiloxane (manufactured by Tokyo Kasei Kogyo Co., Ltd.)", 10 g of the compound (B) obtained in Synthesis Example 3 and 90.3 g of dehydrated toluene were used, To obtain a reactive mesogenic unit (B) '.

Example 1: Synthesis of side chain crystalline polysiloxane (thermosensitive resin)

In a three-necked flask equipped with a stirrer, 1 g of the chain polysiloxane obtained in Synthesis Example 1, 4.72 g of the mesogen unit (A) 'obtained in Synthesis Example 4, and 13.4 g of dehydrated toluene were added. The three-necked flask was placed in an oil bath and heated to 100 DEG C with stirring using a magnetic stirrer. When the temperature reached 100 占 폚, 6 mg of a 20 mass% toluene solution of "platinum (0) -1,3-divinyltetramethyldisiloxane complex" was added. Thereafter, the mixture was stirred at 100 占 폚 for 24 hours. Subsequently, 50 g of acetone heated to 60 DEG C was added to the reaction mixture obtained and stirred. The work of removing the solvent by decantation was repeated three times to obtain a precipitate. The resulting precipitate was dried under reduced pressure at 80 캜 to obtain a side chain crystalline polysiloxane (1).

From the GPC measurement, the obtained side chain crystalline polysiloxane (1) had a number average molecular weight of 109,000 and a weight average molecular weight of 281000. The number average molecular weight and the weight average molecular weight were obtained by measuring the obtained side chain crystalline polysiloxane with GPC and converting the obtained measured value into polystyrene. ^From the integral ratio of ¹ H-NMR, the obtained side chain crystalline polysiloxane (1) contained a vinylmethylsiloxane unit at a ratio of about 10%. From the DSC measurement (10 占 폚 / min), the obtained side chain crystalline polysiloxane (1) had a melting point of about 40 占 폚.

The heat resistance of the resulting side chain crystalline polysiloxane (1) was evaluated by thermogravimetric analysis (TGA). More specifically, the temperature was raised from 25 ° C to 500 ° C (10 ° C / min) under a nitrogen gas atmosphere using a thermogravimetric analyzer "TG / DTA 6200" manufactured by Seiko Instruments Inc. Of the side chain crystalline polysiloxane (1) was measured. Subsequently, the temperature at the time when the mass became 98% with respect to the mass at 25 캜, that is, the 2% mass reduction temperature was measured. The higher the temperature, the better the heat resistance. The results are shown in Table 1.

(Example 2: Synthesis of side chain crystalline polysiloxane (thermosensitive resin)

Side chain crystalline polysiloxane (2) was obtained in the same manner as in Example 1 except that 4.43 g of the mesogen unit (B) 'obtained in Synthesis Example 5 and 12.7 g of dehydrated toluene were used. The number average molecular weight, the weight average molecular weight, the proportion of the vinyl methyl siloxane unit, and the melting point of the obtained side chain crystalline polysiloxane (2) were measured in the same manner as in Example 1. The results are shown below.

Number average molecular weight: 97000

Weight average molecular weight: 270000

Vinyl methyl siloxane unit ratio: about 12%

Melting point: about 66 DEG C

The heat resistance of the resulting side chain crystalline polysiloxane (2) was evaluated in the same manner as in Example 1. The results are shown in Table 1.

(Comparative Example 1)

Heat resistance was evaluated in the same manner as in Example 1 for the acrylic skeleton-containing thermosensitive resin having the following monomer composition. The results are shown in Table 1.

Monomer composition: behenyl acrylate / methyl acrylate / acrylic acid = 45 parts by mass / 50 parts by mass / 5 parts by mass

Melting point: about 55 캜

Weight average molecular weight: 540000

As shown in Table 1, the side chain crystalline polysiloxane (thermosensitive resin) obtained in Examples 1 and 2 has a high 2% mass reduction temperature and excellent heat resistance. On the other hand, the acrylic skeleton-containing thermosensitive resin obtained in Comparative Example 1 had a low 2% mass reduction temperature and insufficient heat resistance.

(Example 3: Production of pressure-sensitive adhesive sheet)

The obtained side chain crystalline polysiloxane (1), polysiloxane having Si-H group and MQ resin were mixed in the ratios shown in Table 2 to prepare a thermosensitive pressure-sensitive adhesive. The polysiloxane and MQ resin having Si-H group used are as follows.

Polysiloxane having Si-H group: " HMS-064 &quot; (Gelest. Inc) represented by the above formula (XII)

MQ resin: &quot; SQO-299 &quot; (manufactured by Gelest. Inc.) Represented by the above formula (XIII)

Toluene was added to 100 parts by mass of the obtained thermosensitive pressure-sensitive adhesive so as to have a solid content concentration of 70% by mass. Thereafter, 0.5 part by mass of the above-mentioned "platinum (0) -1,3-divinyltetramethyldisiloxane complex" in terms of solid content, and 2-methyl-3-butyn-2- Parts by mass to prepare a coating liquid. The obtained coating liquid was applied to one side of a polyethylene terephthalate film (thickness 75 mu m), that is, the side subjected to the fluorosilicon treatment. Subsequently, the resultant was heated at 120 占 폚 for 10 minutes to crosslink the reactive site (vinyl group) of the side chain crystalline polysiloxane with the functional group (Si-H group) of the polysiloxane having Si-H group. Thus, a heat-sensitive adhesive sheet having a pressure-sensitive adhesive layer (thickness of 30 mu m) was obtained.

(Example 4: Production of a pressure-sensitive adhesive sheet)

Sensitive adhesive sheet was obtained in the same manner as in Example 3 except that the side chain crystalline polysiloxane (2) was used instead of the side chain crystalline polysiloxane (1) as shown in Table 2.

(Comparative Example 2: Production of a pressure-sensitive adhesive sheet)

Toluene was added to 100 parts by mass of the acrylic skeleton-containing thermosensitive resin obtained in Comparative Example 1 so that the solid concentration became 30% by mass. 5 parts by mass of trityl amine as a forbidding agent and 1 part by mass of "PZ-33" (Nippon Shokubai Co., Ltd.) as a crosslinking agent were mixed to prepare a coating liquid. The obtained coating liquid was applied to one side of a polyethylene terephthalate film (thickness 50 占 퐉), that is, the side to which the silicon treatment was applied. Subsequently, the sheet was heated at 100 占 폚 for 10 minutes to obtain a pressure-sensitive adhesive sheet on which a crosslinked pressure-sensitive adhesive layer (thickness: 30 占 퐉) was formed.

The heat sensitive adhesive sheets obtained in Examples 3 and 4 and Comparative Example 2 were evaluated for 180 ° peel strength and chemical resistance by the following methods. The results are shown in Table 3.

<180 ° peel strength>

The 180 占 peeling strength against the polyimide under the atmosphere of 80 占 폚 and 5 占 폚 was measured according to JIS Z0237. Specifically, the thermosensitive adhesive sheet was adhered to the alkali-free glass under the following conditions, and then peeled at 180 ° at a speed of 300 mm / min using a load cell.

(80 DEG C)

Sensitive adhesive sheet was attached to an alkali-free glass under an atmosphere of 80 캜 to peel off the polyethylene terephthalate film. Thereafter, a rectangular polyimide film (having a thickness of 25 mu m and a width of 25 mm) was attached and allowed to stand at 80 DEG C for 20 minutes and peeled at 180 DEG.

(5 DEG C)

Sensitive adhesive sheet was attached to an alkali-free glass under an atmosphere of 80 캜 to peel off the polyethylene terephthalate film. Thereafter, a rectangular polyimide film (25 mu m in thickness and 25 mm in width) was attached and allowed to stand at 80 DEG C for 20 minutes. Subsequently, the substrate was cooled to 5 占 폚, allowed to stand for 20 minutes, and then peeled off at 180 占 폚.

<Chemical resistance>

Sensitive adhesive sheets obtained in Examples 3 and 4 and Comparative Example 2 were cut into a rectangular shape to obtain test pieces (2 cm x 5 cm). The obtained test piece was immersed in a chemical mixture solution containing 55 mass% of phosphoric acid, 25 mass% of acetic acid and 20 mass% of water, and allowed to stand at 70 占 폚 for 15 minutes. After 15 minutes, the test piece was taken out from the drug mixture solution and rinsed with water, and visually observed whether or not a white part or a discolored part existed in the thermosensitive adhesive sheet.

As shown in Table 3, from the results of the 180 ° peel strength test, the thermosensitive pressure sensitive adhesive sheets obtained in Examples 3 and 4 were found to have an acrylic skeleton-containing thermosensitive resin (thermosetting resin) at a temperature of 80 ° C or higher than the melting point of the side chain crystalline polysiloxane , It has a sufficient adhesive force and is excellent in fixability. On the other hand, it can be seen that the adhesive force is lowered to such an extent that it can be readily peeled off at the temperature (5 캜) below the melting point of the side chain crystalline polysiloxane.

Further, the heat-sensitive adhesive sheets obtained in Examples 3 and 4 do not show whitened portions or discolored portions even when they are immersed in a chemical mixture solution, and they are also excellent in chemical resistance. On the other hand, in the case of the heat sensitive adhesive sheet obtained in Comparative Example 2, a white part was formed by immersing in the chemical mixture solution, indicating that the chemical resistance was insufficient.

Claims (9)

A thermosensitive resin represented by the following formula (I), which crystallizes at a temperature lower than the melting point and exhibits fluidity at a temperature higher than the melting point.

In the formula (I), R ₁ is the same or different and represents a hydrocarbon group of 1 to 10 carbon atoms. R ₂ represents a group having an alkenyl group. R ₃ represents a polymethylene group having 2 to 11 carbon atoms. R ₄ represents a mesogen group having a structure represented by the following formula (II). m represents an integer of 2 to 10; n represents an integer of 1 to 100; x represents an integer of 0 to 2,000. y represents an integer of 100 to 2000. and z represents an integer of 1 to 1000.

In formula (II), R ₅ represents hydrogen, an aliphatic hydrocarbon group of 1 to 10 carbon atoms, an aromatic hydrocarbon group of 6 to 18 carbon atoms, an alkoxy group of 1 to 10 carbon atoms, or a cyano group. The method according to claim 1,
Wherein the mesogen group has a structure represented by the following formula (II) 'or (II)''.

3. The method according to claim 1 or 2,
Wherein the melting point is not lower than 0 占 폚. A thermosensitive pressure-sensitive adhesive containing the thermosensitive resin according to any one of claims 1 to 3, wherein the adhesive strength is lowered at a temperature lower than the melting point of the resin. 5. The method of claim 4,
Sensitive adhesive having a melting point of 0 ° C or higher. The method according to claim 4 or 5,
A siloxane-polysiloxane having a Si-H group, and a silanol-trimethylsilyl-modified MQ resin. Sensitive adhesive sheet comprising the thermosensitive adhesive according to any one of claims 4 to 6. Sensitive adhesive tape according to any one of claims 4 to 6, wherein the pressure-sensitive adhesive layer comprising the thermosensitive pressure-sensitive adhesive is laminated on at least one surface of the substrate. A thermosensitive pressure-sensitive adhesive composition comprising a thermosensitive resin according to any one of claims 1 to 3, a polysiloxane having a Si-H group, a silanol-trimethylsilyl-modified MQ resin, and a Karstedt catalyst.