JP7058405B2 - Temperature Sensitive Resin, Temperature Sensitive Adhesive and Thermosensitive Adhesive Composition - Google Patents

Description

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

There are known temperature-sensitive resins having a temperature-sensitive property that reversibly show a crystalline state and a flowing state in response to a temperature change (for example, Patent Documents 1 and 2). Since the temperature-sensitive resin is often used as an adhesive, it is desirable that it has excellent heat resistance and chemical resistance, and high cohesive force is also required.

Japanese Unexamined Patent Publication No. 2001-290138 Japanese Unexamined Patent Publication No. 2008-179744

An object of the present invention is to provide a temperature-sensitive resin having excellent heat resistance and chemical resistance and having a high cohesive force, and a temperature-sensitive pressure-sensitive adhesive and a temperature-sensitive pressure-sensitive adhesive composition containing the same. That is.

式（Ｉ）中、Ｒ₁は同一または異なって炭素数１～１０の炭化水素基を示す。Ｒ₂はアルケニル基を有する基を示す。Ｒ₃は炭素数１２～５０の直鎖状アルキル基を示す。ｍは２～１０の整数を示す。ｎは１～１００の整数を示す。ｘは０～２０００の整数を示す。ｙは１００～２０００の整数を示す。ｚは１～１０００の整数を示す。
（２）融点が０℃以上である、上記（１）に記載の感温性樹脂。
（３）上記（１）または（２）に記載の感温性樹脂を含有し、該樹脂の融点未満の温度で粘着力が低下する、感温性粘着剤。
（４）融点が０℃以上である、上記（３）に記載の感温性粘着剤。
（５）Ｓｉ－Ｈ基を有するポリシロキサンおよびシラノール－トリメチルシリル修飾ＭＱレジンをさらに含有する、上記（３）または（４）に記載の感温性粘着剤。
（６）上記（３）～（５）のいずれかに記載の感温性粘着剤を含む、感温性粘着シート。
（７）上記（３）～（５）のいずれかに記載の感温性粘着剤を含む粘着剤層が、基材の少なくとも一方の面に積層された、感温性粘着テープ。
（８）上記（１）または（２）に記載の感温性樹脂、Ｓｉ－Ｈ基を有するポリシロキサン、シラノール－トリメチルシリル修飾ＭＱレジン、およびＫａｒｓｔｅｄｔ触媒を含有する、感温性粘着剤組成物。 As a result of diligent studies to solve the above problems, the present inventors have found a solution means having the following configuration, and have completed the present invention.
(1) A temperature-sensitive resin represented by the following formula (I), which crystallizes at a temperature below the melting point and exhibits fluidity at a temperature above the melting point.

In formula (I), R ₁ represents the same or different hydrocarbon groups having 1 to 10 carbon atoms. R ₂ indicates a group having an alkenyl group. R ₃ represents a linear alkyl group having 12 to 50 carbon atoms. m represents an integer of 2 to 10. n represents an integer from 1 to 100. x indicates an integer from 0 to 2000. y represents an integer from 100 to 2000. z represents an integer from 1 to 1000.
(2) The temperature-sensitive resin according to (1) above, which has a melting point of 0 ° C. or higher.
(3) A temperature-sensitive pressure-sensitive adhesive containing the temperature-sensitive resin according to (1) or (2) above, the adhesive strength of which is lowered at a temperature lower than the melting point of the resin.
(4) The temperature-sensitive adhesive according to (3) above, which has a melting point of 0 ° C. or higher.
(5) The temperature-sensitive pressure-sensitive adhesive according to (3) or (4) above, further containing a polysiloxane having a Si—H group and a silanol-trimethylsilyl modified MQ resin.
(6) A temperature-sensitive adhesive sheet containing the temperature-sensitive adhesive according to any one of (3) to (5) above.
(7) A temperature-sensitive adhesive tape in which a pressure-sensitive adhesive layer containing the temperature-sensitive adhesive according to any one of (3) to (5) above is laminated on at least one surface of a base material.
(8) A temperature-sensitive pressure-sensitive adhesive composition containing the temperature-sensitive resin according to (1) or (2) above, a polysiloxane having a Si—H group, a silanol-trimethylsilyl modified MQ resin, and a Karstedt catalyst.

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

<Temperature sensitive resin>
The temperature-sensitive resin according to the embodiment of the present invention will be described in detail. The temperature-sensitive resin of the present embodiment has a structure represented by the formula (I).

In formula (I), R ₁ represents the same or different hydrocarbon groups having 1 to 10 carbon atoms. The hydrocarbon group having 1 to 10 carbon atoms is not particularly limited, and for example, an alkyl group such as a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group and a hexyl group, a vinyl group, an allyl group, a butenyl group and the like. Examples thereof include an aryl group such as an alkenyl group, a phenyl group, a benzyl group, a phenethyl group and a trill group. The alkyl group or alkenyl group may have a linear structure or a branched structure.

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

In formula (I), R ₃ represents a linear alkyl group having 12 to 50 carbon atoms. The side chain portion containing R ₃ , that is, the side chain portion derived from the compound represented by the following formula (II) is a portion having crystallinity in the temperature-sensitive resin of the present embodiment. The temperature-sensitive resin of the present embodiment crystallizes when the side chains derived from the compound represented by the following formula (II) are aligned with an ordered sequence by an intramolecular force or the like. R ₃ is preferably a linear alkyl group having 14 to 30 carbon atoms, and more preferably a linear alkyl group having 18 to 30 carbon atoms. Specific examples of such an alkyl group include a dodecyl group, a tridecylic group, a tetradecyl group, a pentadecyl group, a hexadecyl group, an octadecyl group, an icosyl group, a docosyl group, a tetracosyl group, a hexacosyl group, an octacosyl group, a triacontyl group, and a tetracontyl group. , Pentacontyl group and the like.

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

Further, in the formula (I), m represents an integer of 2 to 10, preferably an integer of 2 to 6, and more preferably an integer of 2 or 3. n indicates an integer of 1 to 100, preferably an integer of 1 to 40, and more preferably an integer of 1 to 10.

The weight average molecular weight of the temperature-sensitive resin of the present embodiment is not particularly limited. The temperature-sensitive resin of the present embodiment has a weight average molecular weight of preferably 100,000 or more, more preferably 150,000 or more, preferably 2 million or less, and more preferably 1.5 million or less. The "weight average molecular weight" is a value obtained by measuring a temperature-sensitive resin by gel permeation chromatography (GPC) and converting the obtained measured value into polystyrene.

The temperature sensitive resin of the present embodiment has a melting point in relation to crystallization. "Melting point" means the temperature at which a particular portion of a polymer initially matched to an ordered sequence becomes disordered by a certain equilibrium process, at 10 ° C./min by a differential thermal scanning calorimeter (DSC). It means the value obtained by measuring under the conditions. The temperature-sensitive resin of the present embodiment preferably has a melting point of 0 ° C. or higher, more preferably 10 ° C. or higher, preferably 120 ° C. or lower, and more preferably 100 ° C. or lower.

The temperature-sensitive resin of the present embodiment crystallizes at a temperature below the melting point and undergoes a phase transition at a temperature above the melting point to exhibit fluidity. That is, the temperature-sensitive resin of the present embodiment has a temperature-sensitive property that reversibly indicates a crystalline state and a flowing state in response to a temperature change.

The temperature-sensitive resin of the present embodiment is a polysiloxane having a siloxane bond in the main chain, as represented by the formula (I). Specifically, the temperature-sensitive resin of the present embodiment has R ₂ which is a reactive moiety and a side chain derived from a compound represented by the formula (II) which is a crystalline moiety, and has a silicone skeleton. It is a polyorganosiloxane having. With such a configuration, excellent heat resistance and chemical resistance are exhibited. That is, since the conventional temperature-sensitive resin usually has an acrylic skeleton, it is violently hydrolyzed in a chemical environment such as alkali or in a high temperature environment of 200 ° C. or higher. Therefore, the conventional temperature-sensitive resin cannot be used in the above environment.

On the other hand, the temperature-sensitive resin of the present embodiment has a silicone skeleton as described above. As a result, heat resistance and chemical resistance superior to those of the conventional temperature-sensitive resin having an acrylic skeleton are exhibited. Further, in the temperature-sensitive resin of the present embodiment, the average degree of polymerization of the main chain siloxane is high and exceeds 100 (that is, x + y + z of the formula (I) exceeds 100). Therefore, the temperature-sensitive resin of the present embodiment has a higher molecular weight than the conventional temperature-sensitive resin, and exhibits high cohesive force.

Next, an example of the method for producing the temperature-sensitive resin of the present embodiment will be described. In the temperature-sensitive resin of the present embodiment, for example, a chain polysiloxane is obtained by ring-opening polymerization of a cyclic siloxane, and a poly having a linear α-olefin and a Si—H group is added to the chain polysiloxane by an addition reaction. It is obtained by introducing a side chain formed from siloxane (a side chain derived from the compound represented by the above formula (II)). Hereinafter, one embodiment of the production method will be described by taking a specific compound as an example.

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

Octamethylcyclotetrasiloxane represented by the formula (III), tetramethyltetravinylcyclotetrasiloxane represented by the formula (III)', and a chain siloxane represented by the following formula (IV) as a terminal encapsulant. And may be reacted in the presence of a base catalyst represented by the following formula (V).

As described above, R ₁ in the formula (IV) represents a hydrocarbon group having 1 to 10 carbon atoms, which is the same or different. The hydrocarbon group having 1 to 10 carbon atoms is not particularly limited, and for example, an alkyl group such as a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group and a hexyl group, a vinyl group, an allyl group, a butenyl group and the like. Examples thereof include an aryl group such as an alkenyl group, a phenyl group, a benzyl group, a phenethyl group and a trill group. The alkyl group or alkenyl group may have a linear structure or a branched structure. a represents an integer of 0 to 1000, and examples of the compound represented by the formula (IV) include compounds represented by the following formulas (IV)'and (IV)''. Examples of the compound represented by the formula (IV)' include Gelest . Inc's "DMS-V21" and the like are commercially available. Examples of the compound represented by (IV)'' include "KF-96" manufactured by Shin-Etsu Chemical Co., Ltd., "hexamethyldisiloxane" and "octamethyltrisiloxane" manufactured by Tokyo Chemical Industry Co., Ltd. Etc. are commercially available.

In the compound represented by the following formula (V) used as a base catalyst, b represents an integer of 1 to 8. Examples of the compound represented by the formula (V) include Gelest. Inc's "TETRAMETHYLAMMONIUM SILOXANOLATE" and the like are commercially available.

The base catalyst is not limited to the compound represented by the formula (V), and other base catalysts may be used. Other base catalysts include, for example, tetrabutylammonium silanolate, tetramethylphosphonium silanolate, tetrabutylphosphonium silanolate, tetramethylstiponium silanolate, tetrabutylstiponium silanolate, tetrabutylarsonium silanolate, and the like. Examples thereof include silanolates of basic organic compounds such as trimethylsulfonium silanolate and triethylsulfonium silanolate, and silanolates of strongly basic alkali metal hydroxides such as potassium silanolate and cesium silanolate.

The ring-opening polymerization is carried out by the octamethylcyclotetrasiloxane represented by the formula (III), the tetramethyltetravinylcyclotetrasiloxane represented by the formula (III)', and the terminal encapsulant represented by the formula (IV). And the mixture with the base catalyst represented by the formula (V), for example, about 0 to 120 ° C., preferably about 70 to 120 ° C., about 0.1 to 48 hours, preferably about 0.5 to 24 hours. It is done by reacting. The reaction may be carried out in a solvent such as toluene, if necessary.

The mixing ratio of the octamethylcyclotetrasiloxane represented by the formula (III) and the tetramethyltetravinylcyclotetrasiloxane represented by the formula (III)'is not particularly limited. For example, the siloxane represented by the formula (III) and the siloxane represented by the formula (III)'are mixed in a molar ratio of 0: 1 to 5: 1, preferably 0: 1 to 2: 1. The end-capping agent is preferably added in a proportion of 0.00001 to 30 parts by mass with respect to 100 parts by mass of the mixture of siloxanes represented by the formulas (III) and (III)'. The base catalyst is preferably added at a ratio of 0.000000001 to 1 part by mass with respect to 100 parts by mass of the mixture of siloxane represented by the formula (III) and the formula (III)'. In this way, a chain polysiloxane represented by the following formula (VI) can be obtained. In the formula (VI), c represents an integer of 0 to 2000, and d represents an integer of 101 to 3000. The chain polysiloxane represented by the formula (VI) uses a compound represented by the formula (IV)'as an end-capping agent.

Next, the addition reaction will be described. First, a linear α-olefin and a polysiloxane having Si—H groups at both ends are reacted in the presence of a Karstedt catalyst represented by the following formula (VII). Then, the obtained reactant (compound represented by the above formula (II)) and the chain polysiloxane represented by the formula (VI) are combined with each other in the presence of a Karstedt catalyst represented by the formula (VII). React. A commercially available product may be used as the Karstedt catalyst, for example, "Platinum (0) -1,3-divinyltetramethyldisiloxane complex" manufactured by Tokyo Chemical Industry Co., Ltd., Gelest. Inc's "SIP6831.2", "SIP6831.2LC", etc. are commercially available.

Examples of the linear α-olefin include linear α-olefins having 12 to 50 carbon atoms. Among these, a linear α-olefin having 14 to 30 carbon atoms is preferable, and a linear α-olefin having 18 to 30 carbon atoms is more preferable. Specific examples of such a linear α-olefin include 1-octadecene represented by the following formula (VIII) and 1-docosen represented by the formula (VIII)'. Commercially available products may be used as the linear α-olefin, for example, "Linearene 18 (1-octadecene)" and "Linearene 2024 (linear α-olefin having 18 to 26 carbon atoms) manufactured by Idemitsu Kosan Co., Ltd. Mixture of) ”is commercially available.

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

Specifically, the addition reaction is carried out in the following two-step reaction. First, polysiloxane (formula (IX)) having Si—H groups at both ends is added at a molar ratio of, for example, 1 to 20, preferably 4 to 10, with respect to a linear α-olefin molar ratio of 1. , Karstedt catalyst is added at a rate of, for example, 10 to 100 ppm, preferably 10 to 50 ppm. Then, 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. In this way, in the first-step reaction, the compound represented by the above formula (II) is obtained.

Then, the obtained compound represented by the formula (II) and the chain polysiloxane represented by the formula (VI) are reacted in the presence of a Karstedt catalyst represented by the formula (VII). The chain polysiloxane represented by the formula (VI) is added, for example, at a molar ratio of, for example, 0.1 to 1, preferably 0.2 to 1, with respect to the compound molar ratio 1 represented by the formula (II). , Karstedt catalyst is added at a rate of, for example, 10 to 100 ppm, preferably 10 to 50 ppm. Then, 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 second-step reaction may be carried out by isolating the compound represented by the formula (II), and after the completion of the first-step reaction, the compound represented by the formula (II) is not isolated and the formula is added to the reaction mixture. A chain polysiloxane represented by (VI) may be added.

In this way, for example, when 1-octadecene represented by the formula (VIII) is used as the linear α-olefin and tetramethyldisiloxane represented by the formula (IX)'is used as the siloxane, the following formula is used. A side-chain crystalline polysiloxane represented by (X) (an example of a temperature-sensitive resin according to the present embodiment) can be obtained. The x, y and z of the formula (X) are as described above, and the description thereof will be omitted.

After the reaction, the reaction product may be used as it is as a temperature-sensitive resin, or the reaction product may be purified and used as a temperature-sensitive resin. Examples of the purification method include a method of removing impurities such as asymmetric olefins by solvent washing or reprecipitation. The solvent is not particularly limited, and examples thereof include acetone and a mixed solvent of toluene and acetone. Whether or not the impurities have been removed may be confirmed by, for example, GPC, ¹ H-NMR, or the like.

<Temperature sensitive adhesive>
Next, the temperature-sensitive pressure-sensitive adhesive according to the embodiment of the present invention will be described in detail. The temperature-sensitive pressure-sensitive adhesive of the present embodiment contains the temperature-sensitive resin according to the above-mentioned embodiment, and the adhesive strength decreases at a temperature lower than the melting point of the temperature-sensitive resin. The temperature-sensitive pressure-sensitive adhesive of the present embodiment contains a temperature-sensitive adhesive whose adhesive strength is reduced by crystallizing the temperature-sensitive resin at a temperature below the melting point. Therefore, when the temperature-sensitive adhesive is peeled off from the adherend, when the temperature-sensitive adhesive is cooled to a temperature lower than the melting point of the temperature-sensitive resin, the temperature-sensitive resin crystallizes and the adhesive strength is lowered. On the other hand, when the temperature-sensitive adhesive is heated to a temperature equal to or higher than the melting point of the temperature-sensitive resin, the temperature-sensitive resin exhibits fluidity and the adhesive strength is restored. As a result, the temperature-sensitive adhesive of the present embodiment can be used repeatedly.

The temperature-sensitive pressure-sensitive adhesive of the present embodiment preferably contains a polysiloxane having a Si—H group and a silanol-trimethylsilyl modified MQ resin (hereinafter, may be simply referred to as “MQ resin”).

The polysiloxane having a Si—H group undergoes a cross-linking reaction with the temperature-sensitive resin to make it three-dimensional, and can impart cohesive force to the temperature-sensitive resin. As a result, the adhesiveness of the temperature-sensitive 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 (XI) to (XI) ″. In equation (XI), f represents an integer from 0 to 2000. G in the formula (XI)'represents an integer from 2 to 200. In equation (XI) ″, h represents an integer of 0 to 5000, and i represents an integer of 2 to 2000. Commercially available products may be used as the polysiloxane having a Si—H group, and for example, “HMS-991”, “HMS-501”, “HMS-013”, “HMS-031”, “HMS-064”, “ HMS-071 ”,“ HMS-064 ”,“ HMS-082 ”,“ HMS-151 ”,“ DMS-H11 ”,“ DMS-H21 ”,“ DMS-H31 ”,“ DMS-H41 ” .Inc) etc. are commercially available.

The MQ resin functions as a cohesive component in the temperature-sensitive pressure-sensitive adhesive of the present embodiment. The MQ resin has a structure represented by the following formula (XII), formula (XII)'and the like, and usually has good compatibility with the above-mentioned temperature-sensitive resin. As the MQ resin, a commercially available product may be used, for example, Gelest. Inc's "SQO-299", "VQX-221", Silicon Corporation's "Silmer VQ20", "Silmer VQ2012", "Silmer VQ122XYL", "Silmer VQ9XYL", etc. are commercially available.

When the temperature-sensitive pressure-sensitive adhesive of the present embodiment contains a polysiloxane having a Si—H group and an MQ resin, the content of each component is not particularly limited. For example, the polysiloxane having a Si—H group is contained in a proportion of preferably 0.001 to 1000 parts by mass, more preferably 0.01 to 500 parts by mass with respect to 100 parts by mass of the temperature sensitive 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 temperature-sensitive resin.

The temperature-sensitive pressure-sensitive adhesive of the present embodiment may be applied directly to the adherend, for example, or may be used in the form of a sheet without a base material, and the form of use is not particularly limited. For example, when the temperature-sensitive pressure-sensitive adhesive of the present embodiment is used as the temperature-sensitive pressure-sensitive adhesive sheet, the thickness of the temperature-sensitive pressure-sensitive adhesive sheet is preferably 10 to 500 μm, more preferably 10 to 200 μm.

The temperature-sensitive adhesive of the present embodiment may be used in the form of a tape. When the temperature-sensitive adhesive of the present embodiment is used as the temperature-sensitive adhesive tape, the pressure-sensitive adhesive layer containing the temperature-sensitive adhesive of the present embodiment is laminated on at least one surface of the base material. The base material is preferably in the form of a film, and the form of a film also includes a form of a sheet.

Examples of the constituent materials of the base material include polyethylene, polyethylene terephthalate, polyethylene naphthalate, polypropylene, polyester, polyamide, polyimide, polyamideimide, polycarbonate, ethylene vinyl acetate copolymer, ethylene ethyl acrylate copolymer, and ethylene polypropylene copolymer weight. Examples thereof include synthetic resins such as coalesced, polyvinyl chloride, and polyether ether ketone.

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

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

Usually, a Karstedt catalyst for carrying out a cross-linking reaction is added to the coating liquid, and a banning agent for suppressing the reaction before coating may be added. As a result, it is possible to suppress the formation of a complex between the inhibitor and the Karstedt catalyst and the occurrence of a cross-linking reaction in the pressure-sensitive adhesive layer. When the inhibitor is volatilized by heating above the boiling point of the inhibitor, the cross-linking reaction mediated by the Karstedt catalyst proceeds. Examples of the banning agent include 1-butyne-2-ol, 2-methyl-3-butyne-2-ol, 3,5-dimethyl-1-hexin-3-ol, 3-methyl-1-pentene-3. -Ol, phenylbutynol, 1-ethynyl-1-cyclohexanol and the like can be mentioned.

The Karstedt catalyst is added to the temperature sensitive resin so that the concentration of platinum is preferably 1 to 1000 ppm. On the other hand, the prohibitive agent is preferably added at a ratio of 1 to 5 parts by mass with respect to 100 parts by mass of the temperature sensitive resin. The composition of the coating liquid is the same when the temperature-sensitive adhesive is directly applied to the adherend and used, or when it is used in the form of a base material-less sheet.

The pressure-sensitive adhesive layer preferably has a thickness of 1 to 100 μm, more preferably 5 to 80 μm, and even more preferably 10 to 60 μm. When the pressure-sensitive adhesive layers are 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 temperature-sensitive pressure-sensitive adhesive forming the pressure-sensitive adhesive layer may be the same or different. May be.

Further, as long as the pressure-sensitive adhesive containing the temperature-sensitive pressure-sensitive adhesive of the present embodiment is laminated on one surface of the base material, another pressure-sensitive adhesive layer may be laminated on the other surface. For example, an adhesive layer containing a pressure sensitive adhesive may be laminated on the other surface. The pressure sensitive adhesive comprises a polymer having adhesiveness. Examples of the polymer having such adhesiveness include natural rubber adhesives, synthetic rubber adhesives, styrene / butadiene latex-based adhesives, acrylic adhesives and the like.

It is preferable to laminate a release film on the surfaces of the temperature-sensitive adhesive sheet and the temperature-sensitive adhesive tape of the present embodiment. Examples of the release film include a polyethylene terephthalate film having a release agent such as fluorosilicone coated on the surface thereof.

<Temperature Sensitive Adhesive Composition>
Next, the temperature-sensitive pressure-sensitive adhesive composition according to the embodiment of the present invention will be described in detail. The temperature-sensitive pressure-sensitive adhesive of the present embodiment contains the temperature-sensitive resin according to the above-mentioned embodiment, polysiloxane having a Si—H group, silanol-trimethylsilyl modified MQ resin, and Karstedt catalyst. If necessary, the above-mentioned banning agent may be added. The details of each component are as described above, and the description thereof will be omitted.

As described above, the temperature-sensitive resin according to the embodiment of the present invention has excellent heat resistance and chemical resistance, and has a high cohesive force. The use of the temperature-sensitive pressure-sensitive adhesive containing such a temperature-sensitive resin is not particularly limited, and for example, it is suitably used as a pressure-sensitive adhesive in a field where heat resistance and chemical resistance are required.

The present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the gist of the present invention. For example, in the above-mentioned embodiment, a temperature-sensitive adhesive containing a temperature-sensitive resin, a polysiloxane having a Si—H group, and an MQ resin has been described as an example. However, the temperature-sensitive pressure-sensitive adhesive is not limited to the configuration containing a polysiloxane having a Si—H group and an MQ resin as long as it contains the above-mentioned temperature-sensitive adhesive, and is a so-called silicone-based pressure-sensitive adhesive. It can be made of common materials used.

Hereinafter, the present invention will be specifically described with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples.

(Synthesis Example 1: Synthesis of chain polysiloxane)
To a three-necked flask equipped with a stirring blade and a nitrogen introduction tube, 20 g of cyclic siloxane and 400 mg of terminal sealant were added. As the cyclic siloxane, "tetravinyltetramethylcyclotetrasiloxane (manufactured by Tokyo Chemical Industry Co., Ltd.)" was used, and as the terminal encapsulant, "DMS-21 (manufactured by Gelest. Inc)" was used. Nitrogen was introduced into the mixture of the cyclic siloxane and the terminal encapsulant from the nitrogen introduction tube, and nitrogen bubbling was performed for 30 minutes with stirring. The nitrogen inlet tube was then separated from the mixture and the three-necked flask was placed in an oil bath. 7 mg of "TETRAMETHYLAMMONIUM SILOXANOLATE" (manufactured by Tokyo Chemical Industry Co., Ltd.) was added to a three-necked flask as a base catalyst, and the mixture was stirred at 100 ° C. for 6 hours. Then, 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 mixture was cooled to room temperature to obtain a chain polysiloxane (A) represented by the formula (VI). The chain polysiloxane (A) obtained from the GPC measurement had a number average molecular weight of 55,000 and a weight average molecular weight of 137,000. The number average molecule and the weight average molecular weight were obtained by measuring the obtained chain polysiloxane with GPC and converting the obtained measured value into polystyrene.

(Synthesis Example 2: Synthesis of chain polysiloxane)
A chain polysiloxane (B) was obtained in the same procedure as in Synthesis Example 1 except that the amount of the terminal sealant (DMS-21) used was changed to 100 mg. The chain polysiloxane (B) obtained from GPC measurements had a number average molecular weight of 77,000 and a weight average molecular weight of 218,000.

(Synthesis Example 3: Synthesis of chain polysiloxane)
16 g of "tetravinyltetramethylcyclotetrasiloxane" and 4 g of "hexamethylcyclotetrasiloxane (manufactured by Tokyo Chemical Industry Co., Ltd.)" are used as the cyclic siloxane, and 200 mg of "hexamethyldisiloxane" is used as the terminal encapsulant. A chain polysiloxane (C) was obtained by the same procedure as in Synthesis Example 1 except that the change was made to Tokyo Chemical Industry Co., Ltd.). The chain polysiloxane (C) obtained from GPC measurements had a number average molecular weight of 60,000 and a weight average molecular weight of 126,000.

(Synthesis Example 4: Synthesis of long-chain alkyl unit)
108.8 g of "Tetramethyldisiloxane (manufactured by Tokyo Chemical Industry Co., Ltd.)" and 50 g of "1-docosen (manufactured by Tokyo Chemical Industry Co., Ltd.)" in a three-necked flask equipped with a stirring blade and a thermometer. And 240 g of dehydrated toluene was added. The three-necked flask was placed in an oil bath and heated to 70 ° C. with stirring. When the temperature reached 70 ° C., 50 mg of a 20% by mass toluene solution of "platinum (0) -1,3-divinyltetramethyldisiloxane complex (manufactured by Tokyo Chemical Industry Co., Ltd.)" was added. Then, the mixture was stirred at 70 ° C. for 24 hours. Next, a Dean-Stark apparatus was attached to the three-necked flask and heated at 100 ° C. for 3 hours to recover unreacted tetramethyldisiloxane. Then, the reaction mixture in the three-necked flask was added dropwise to ethanol for precipitation purification. The precipitate was collected by suction filtration and dried under reduced pressure at 80 ° C. to obtain a one-ended reactive long-chain alkyl unit represented by the formula (II).

(Example 1)
<Synthesis of side chain crystalline polysiloxane (temperature sensitive resin)>
In a three-necked flask containing a stirrer, 3 g of the chain polysiloxane (A) obtained in Synthesis Example 1, 14.3 g of the long-chain alkyl unit obtained in Synthesis Example 4, and 40 g of dehydrated toluene were placed. Added. The three-necked flask was placed in an oil bath and heated to 100 ° C. with stirring using a magnetic stirrer. At 100 ° C., 60 mg of a 20 mass% toluene solution of "platinum (0) -1,3-divinyltetramethyldisiloxane complex" was added. Then, the mixture was stirred at 100 ° C. for 24 hours. Then, 100 g of a mixed solvent of toluene and acetone (mass ratio 3: 7) was heated to 60 ° C., added to the obtained reaction mixture, and stirred. The operation of removing the solvent by decantation was repeated three times to obtain a precipitate. The obtained precipitate was dried under reduced pressure at 80 ° C. to obtain a side chain crystalline polysiloxane (1).

The side chain crystalline polysiloxane (1) obtained from the GPC measurement had a number average molecular weight of 103000 and a weight average molecular weight of 503000. The number average molecule 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. The side chain crystalline polysiloxane (1) obtained from the integral ratio of ¹ H-NMR contained vinylmethylsiloxane units in a proportion of about 3 mol% . Specifically, before the reaction between the chain polysiloxane represented by the formula (VI) obtained in Synthesis Example 1 and the long-chain alkyl unit obtained in Synthesis Example 4, y / z = 0 / Since "y" does not exist in 100, that is, "d (y + z)" of the chain polysiloxane represented by the formula (VI), it is substantially only "z". By the reaction of the chain polysiloxane represented by the formula (VI) with the long-chain alkyl unit, 97 mol% of the unit related to d reacts with the long-chain alkyl unit to become the unit related to y, and 3 mol% of the unit related to d. A side-chain crystalline polysiloxane (temperature-sensitive resin) was obtained, which remained unreacted and became a unit related to z. Further, the side chain crystalline polysiloxane (1) obtained from DSC measurement (10 ° C./min) had a melting point of about 37 ° C.

<Preparation of temperature sensitive adhesive>
The obtained side chain crystalline polysiloxane (1), MQ resin and polysiloxane having a Si—H group were mixed at the ratios shown in Table 1 to prepare a temperature-sensitive pressure-sensitive adhesive. The polysiloxanes and MQ resins with Si—H groups used are as follows.
Polysiloxane having Si—H group: “HMS-064” and “HMS-082” represented by the above formula (XI) ″ (both manufactured by Gelest Inc).
MQ resin: "VQX-221" represented by the above formula (XII)'(manufactured by Gelest Inc)

<Making temperature-sensitive adhesive tape>
Toluene was added to 100 parts by mass of the obtained temperature-sensitive pressure-sensitive adhesive so that the solid content concentration was 70% by mass. There, 0.5 parts by mass of the above "platinum (0) -1,3-divinyltetramethyldisiloxane complex" in terms of solid content, and 2-methyl-3-butyne-2-ol as a banning agent are solid. A coating solution was prepared by adding 1 part by mass in terms of minutes. The obtained coating liquid was applied to one side of a polyethylene terephthalate film (thickness 75 μm), that is, a surface treated with fluorosilicone. Then, it is heated at 120 ° C. for 10 minutes, and the functional group (Si-) of the polysiloxane having the reactive moiety (vinyl group) of the side chain crystalline polysiloxane and the reactive moiety (vinyl group) of the MQ resin and the Si—H group. H group) was crosslinked. In this way, a temperature-sensitive adhesive tape on which the adhesive layer (thickness 30 μm) was formed was obtained.

(Example 2)
The procedure was the same as in Example 1 except that the chain polysiloxane (B) obtained in 3 g of Synthesis Example 2, the long chain alkyl unit obtained in 15 g of Synthesis Example 4, and 42 g of dehydrated toluene were used. A side chain crystalline polysiloxane (2) was obtained. The number average molecular weight, weight average molecular weight, ratio of vinylmethylsiloxane unit, and melting point of the obtained side chain crystalline polysiloxane (2) were measured by the same procedure as in Example 1. The results are shown below.
Number average molecular weight: 124000
Weight average molecular weight: 513000
Percentage of vinyl methyl siloxane units: approx. 10 mol%
Melting point: Approximately 39 ° C

A temperature-sensitive pressure-sensitive adhesive was prepared in the same procedure as in Example 1 except that the side-chain crystalline polysiloxane (2) was used. A temperature-sensitive adhesive tape was produced in the same procedure as in Example 1 except that this temperature-sensitive adhesive was used.

(Example 3: Synthesis of side chain crystalline polysiloxane)
A side chain crystalline polysiloxane (3) was obtained in the same procedure as in Example 1 except that the chain polysiloxane (C) obtained in 3 g of Synthesis Example 3 was used. The number average molecular weight, weight average molecular weight, ratio of vinylmethylsiloxane unit, and melting point of the obtained side chain crystalline polysiloxane (3) were measured by the same procedure as in Example 1. The results are shown below.
Number average molecular weight: 102000
Weight average molecular weight: 322000
Percentage of vinyl methyl siloxane units: approx. 25 mol%
Melting point: Approximately 31 ° C

A temperature-sensitive pressure-sensitive adhesive was prepared in the same procedure as in Example 1 except that the side-chain crystalline polysiloxane (3) was used. A temperature-sensitive adhesive tape was produced in the same procedure as in Example 1 except that this temperature-sensitive adhesive was used.

(Comparative Example 1)
A temperature-sensitive adhesive tape was applied in the same procedure as in Example 1 except that a temperature-sensitive adhesive made of an acrylic skeleton-containing temperature-sensitive resin was used instead of the temperature-sensitive adhesive obtained in Example 1. Made. The monomer composition, melting point and weight average molecular weight of the acrylic skeleton-containing temperature-sensitive resin are as follows.
Monomer composition: behenyl acrylate / methyl acrylate / acrylic acid = 45 parts by mass / 50 parts by mass / 5 parts by mass Melting point: Approx. 55 ° C.
Weight average molecular weight: 540000

The temperature-sensitive adhesive tapes obtained in Examples 1 to 3 and Comparative Example 1 were evaluated for 180 ° peel strength, heat resistance and chemical resistance by the following methods. The results are shown in Table 2.

<180 ° peel strength>
The 180 ° peel strength with respect to the polyimide under the atmosphere of 80 ° C. and 5 ° C. was measured according to JIS Z0237. Specifically, a temperature-sensitive adhesive tape was attached to non-alkali glass under the following conditions, and then peeled off by 180 ° at a speed of 300 mm / min using a load cell.
(80 ° C)
A temperature-sensitive adhesive tape was attached to non-alkali glass in an atmosphere of 80 ° C., and the polyethylene terephthalate film was peeled off. Then, a strip-shaped polyimide film (thickness 25 μm and width 25 mm) was attached, allowed to stand at 80 ° C. for 20 minutes, and peeled off by 180 °.
(5 ° C)
A temperature-sensitive adhesive tape was attached to non-alkali glass in an atmosphere of 80 ° C., and the polyethylene terephthalate film was peeled off. Then, a strip-shaped polyimide film (thickness 25 μm and width 25 mm) was attached and allowed to stand at 80 ° C. for 20 minutes. Then, it was cooled to 5 ° C., allowed to stand for 20 minutes, and then peeled off by 180 °.

<Heat resistance>
It was evaluated by thermogravimetric analysis (TGA). Specifically, a thermogravimetric analyzer "TG / DTA 6200" manufactured by Seiko Instruments Inc. was used to raise the temperature from 25 ° C to 500 ° C (10 ° C / min) in a nitrogen gas atmosphere. The mass change of the side chain crystalline polysiloxane in the process was measured. Then, the temperature at the time when the mass became 98% with respect to the mass at 25 ° C., that is, the 2% mass reduction temperature was measured. The higher the temperature, the better the heat resistance.

<Chemical resistance>
The temperature-sensitive adhesive tape was immersed in a 10 mass% sodium hydroxide aqueous solution at 23 ° C. for 10 minutes. Then, the state of the temperature-sensitive adhesive tape was evaluated according to the following criteria.
(Evaluation criteria)
◯: When the temperature-sensitive adhesive tape is not swollen.
X: When the temperature-sensitive adhesive tape is swollen.

As shown in Table 2, it can be seen that the temperature-sensitive adhesive tapes obtained in Examples 1 to 3 have excellent chemical resistance and are also excellent in 180 ° peel strength. Further, it can be seen that the side chain crystalline polysiloxanes (temperature sensitive resins) obtained in Examples 1 to 3 have a high 2% weight loss temperature and excellent heat resistance.

Claims (8)

A temperature-sensitive resin represented by the following formula (I)'or (I)', which crystallizes at a temperature below the melting point and exhibits fluidity at a temperature above the melting point.

In formula (I)'or (I)'', R ₁ represents at least one of the same or different alkyl group having 1 to 10 carbon atoms and aryl group having 6 to 10 carbon atoms. R ₂ indicates a group having an alkenyl group. R ₃ represents a linear alkyl group having 12 to 50 carbon atoms. m represents an integer of 2 to 10. n represents an integer from 1 to 100. x indicates an integer from 0 to 2000. y represents an integer from 100 to 2000. z represents an integer from 1 to 1000. The temperature-sensitive resin according to claim 1, wherein the melting point is 0 ° C. or higher. A temperature-sensitive pressure-sensitive adhesive containing the temperature-sensitive resin according to claim 1 or 2, wherein the adhesive strength decreases at a temperature lower than the melting point of the resin. The temperature-sensitive pressure-sensitive adhesive according to claim 3, wherein the melting point is 0 ° C. or higher. The temperature-sensitive pressure-sensitive adhesive according to claim 3 or 4, further comprising a polysiloxane having a Si—H group and a silanol-trimethylsilyl modified MQ resin. A temperature-sensitive adhesive sheet containing the temperature-sensitive adhesive according to any one of claims 3 to 5. A temperature-sensitive adhesive tape in which a pressure-sensitive adhesive layer containing the temperature-sensitive pressure-sensitive adhesive according to any one of claims 3 to 5 is laminated on at least one surface of a base material. A temperature-sensitive pressure-sensitive adhesive composition comprising the temperature-sensitive resin according to claim 1 or 2, a polysiloxane having a Si—H group, a silanol-trimethylsilyl modified MQ resin, and a Karstedt catalyst.