JP2018003008A - Temperature-sensitive resin, temperature-sensitive adhesive and temperature-sensitive adhesive composition - Google Patents

Abstract

A temperature-sensitive resin having excellent heat resistance and chemical resistance, and a temperature-sensitive adhesive and a temperature-sensitive adhesive composition containing the same. A thermosensitive resin represented by the formula (I), which crystallizes at a temperature lower than the melting point and exhibits fluidity at a temperature higher than the melting point. (R4 is a mesogen group having a liquid crystal molecular structure) [Selection] None

Description

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

  Thermosensitive resins having temperature sensitivity that reversibly show a crystalline state and a fluid state corresponding to a temperature change are known (for example, Patent Documents 1 and 2). Since the temperature sensitive resin is often used as an adhesive, it is desirable to have excellent heat resistance and chemical resistance.

JP 2001-290138 A JP 2008-179744 A

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

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２〜１１のポリメチレン基を示す。Ｒ₄は下記式（ＩＩ）で表される構造を有するメソゲン基を示す。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２〜１０００の整数を示す。

式（ＩＩ）中、Ｒ₅は水素、炭素数１〜１０の脂肪族炭化水素基、炭素数６〜１８の芳香族炭化水素基、炭素数１〜１０のアルコキシ基、またはシアノ基を示す。
（２）メソゲン基が下記式（ＩＩ）’または（ＩＩ）’’で表される構造を有している、上記（１）に記載の感温性樹脂。

（３）融点が０℃以上である、上記（１）または（２）に記載の感温性樹脂。
（４）上記（１）〜（３）のいずれか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。
（５）融点が０℃以上である、上記（４）に記載の感温性粘着剤。
（６）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（４）または（５）に記載の感温性粘着剤。
（７）上記（４）〜（６）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。
（８）上記（４）〜（６）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。
（９）上記（１）〜（３）のいずれか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 intensive 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), crystallized at a temperature lower than the melting point, and exhibits fluidity at a temperature higher than the melting point.

In formula (I), R ₁ represents a hydrocarbon group having 1 to 10 carbon atoms the same or different. 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 mesogenic group having a structure represented by the following formula (II). m represents an integer of 2 to 10. n shows the integer of 1-100. x shows the integer of 0-2000. y shows the integer of 100-2000. z shows the integer of 2-1000.

In formula (II), R ₅ represents hydrogen, an aliphatic hydrocarbon group having 1 to 10 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, or a cyano group.
(2) The temperature-sensitive resin according to (1) above, wherein the mesogenic group has a structure represented by the following formula (II) ′ or (II) ″.

(3) The temperature-sensitive resin according to (1) or (2), wherein the melting point is 0 ° C. or higher.
(4) A temperature-sensitive adhesive comprising the temperature-sensitive resin according to any one of (1) to (3), wherein the adhesive strength is reduced at a temperature lower than the melting point of the resin.
(5) The temperature-sensitive adhesive according to (4), wherein the melting point is 0 ° C. or higher.
(6) The temperature-sensitive adhesive according to (4) or (5), further comprising a polysiloxane having a Si—H group and a silanol-trimethylsilyl modified MQ resin.
(7) A temperature-sensitive adhesive sheet containing the temperature-sensitive adhesive according to any one of (4) to (6) above.
(8) A temperature-sensitive adhesive tape in which an adhesive layer containing the temperature-sensitive adhesive according to any one of (4) to (6) is laminated on at least one surface of a substrate.
(9) A temperature-sensitive adhesive containing the temperature-sensitive resin according to any one of (1) to (3) above, a polysiloxane having a Si-H group, a silanol-trimethylsilyl-modified MQ resin, and a Karstedt catalyst Composition.

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

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

In formula (I), R ₁ represents a hydrocarbon group having 1 to 10 carbon atoms the same or different. 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, vinyl group, allyl group, and butenyl group. Examples thereof include aryl groups such as alkenyl group, phenyl group, benzyl group, phenethyl group and tolyl group. The alkyl group or alkenyl group may have a linear structure or a branched structure.

In the formula (I), R ₂ represents a group having an alkenyl group. The group having an alkenyl group is a reactive site in the temperature-sensitive 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 group, allyl group, butenyl group, pentenyl group, hexenyl group, heptenyl group, octenyl group, nonenyl group, and decenyl group.

In formula (I), R ₃ represents a polymethylene group having 2 to 11 carbon atoms. The side chain portion containing R ₃ , that is, the side chain portion derived from the compound represented by the following formula (III) is a site having crystallinity in the thermosensitive resin of the present embodiment. The temperature-sensitive resin of this embodiment is crystallized by aligning side chains derived from the compound represented by the following formula (III) in an ordered arrangement by intermolecular 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 mesogenic group having a structure represented by the following formula (II). A mesogenic group means a rigid and highly oriented group that contributes to the development of liquid crystallinity. In formula (II), R ₅ represents hydrogen, an aliphatic hydrocarbon group having 1 to 10 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, an alkoxy group having 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 methoxy group, ethoxy group, butoxy group, octyloxy group, decyloxy group, diethoxy group, triethoxy group, and tetraethoxy group. R ₅ is preferably an n-butyl group or a methoxy group. Mesogenic groups having a structure represented by the formula (II) in which R ₅ is an n-butyl group or a methoxy group are shown in the following formulas (II) ′ and (II) ″.

  In 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 represents an integer of 100 to 2000, preferably an integer of 100 to 1500, and more preferably an integer of 200 to 1500. z shows the integer of 2-1000, Preferably the integer of 2-1000 is shown, More preferably, the integer of 2-800 is shown.

  Furthermore, in formula (I), m represents an integer of 2 to 10, preferably an integer of 2 to 6, and more preferably an integer of 2 to 3. n shows the integer of 1-100, Preferably the integer of 2-40 is shown, More preferably, the integer of 2-10 is shown.

  The weight average molecular weight of the temperature sensitive resin of this embodiment is not particularly limited. The temperature-sensitive 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 million or less, 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 measurement value into polystyrene.

  The temperature-sensitive resin of this embodiment has a melting point related to crystallization. “Melting point” refers to the temperature at which a particular portion of the polymer that was initially aligned in an ordered sequence becomes disordered by an equilibrium process and is measured by differential thermal scanning calorimetry (DSC) at 10 ° C./min. It means the value obtained by measuring under 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, more preferably 100 ° C. or lower.

  The temperature-sensitive resin of this embodiment is crystallized at a temperature lower than the melting point, and undergoes phase transition and exhibits fluidity at a temperature higher than the melting point. That is, the temperature-sensitive resin of the present embodiment has temperature sensitivity that reversibly shows a crystalline state and a fluid state corresponding 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 thermosensitive resin of the present embodiment has a reactive site R ₂ and a side chain derived from the compound represented by the formula (III) which is a crystalline site, 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 conventional temperature-sensitive resins usually have an acrylic skeleton, they are vigorously 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 conventional temperature-sensitive resins having an acrylic skeleton are exhibited. The temperature sensitive resin of this embodiment can be used even in a high temperature environment of, for example, 250 ° C. or higher.

  Next, an example of a method for producing the temperature sensitive resin of the present embodiment will be described. The temperature-sensitive resin of the present embodiment is obtained by, for example, obtaining a chain polysiloxane by ring-opening polymerization of a cyclic siloxane, and adding a side chain formed from a siloxane and a mesogenic group to the chain polysiloxane by an addition reaction (the above formula) It is obtained by introducing a side chain derived from the compound represented by (III). Hereinafter, an embodiment of the production method will be described by taking specific compounds as examples.

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

  Octamethylcyclotetrasiloxane represented by the formula (IV), tetramethyltetravinylcyclotetrasiloxane represented by the formula (IV) ′, and a chain siloxane represented by the following formula (V) as a terminal blocking agent May be reacted in the presence of a base catalyst represented by the following formula (VI).

R ₁ in formula (V) as described above, a hydrocarbon group having 1 to 10 carbon atoms the same or different. 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, vinyl group, allyl group, and butenyl group. Examples thereof include aryl groups such as alkenyl group, phenyl group, benzyl group, phenethyl group and tolyl 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 (V) include compounds represented by the following formulas (V) ′ and (V) ″. Examples of the compound represented by the formula (V) ′ include “1,1,4,4-tetramethyl-1,1,4,4-tetravinyldisiloxane” manufactured by Tokyo Chemical Industry Co., Ltd. and Gelest. . Inc. “DMS-V21” is commercially available. Examples of the compound represented by (V) '' include “KF-96” manufactured by Shin-Etsu Chemical Co., Ltd., “hexamethyldisiloxane” and “octamethyltrisiloxane” manufactured by Tokyo Chemical Industry Co., Ltd. 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. Examples of the compound represented by the formula (VI) include Gelest. “TETRAMETHYLAMMONIUM SILOX ANOLATE” manufactured by Inc. is commercially available.

  A base catalyst is not limited to the compound represented by Formula (V), You may use another base catalyst. Examples of other base catalysts include tetrabutylammonium silanolate, tetramethylphosphonium silanolate, tetrabutylphosphonium silanolate, tetramethylstiponium silanolate, tetrabutylstiponium silanolate, tetrabutylarsonium silanolate, 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.

  Ring-opening polymerization includes octamethylcyclotetrasiloxane represented by the formula (IV), tetramethyltetravinylcyclotetrasiloxane represented by the formula (IV) ′, and an end-capping agent represented by the formula (V). And a base catalyst represented by the formula (VI) is, 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. This is done by reacting. The reaction may be performed in a solvent such as toluene as necessary.

  The mixing ratio of octamethylcyclotetrasiloxane represented by the formula (IV) and 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 in a molar ratio of 0: 1 to 5: 1, preferably 0: 1 to 2: 1. The terminal blocking agent is preferably added at a ratio of 0.00001 to 30 parts by mass with respect to 100 parts by mass of the mixture of siloxanes represented by the formula (IV) and the formula (IV) ′. The base catalyst is preferably added at a ratio of 0.0000001 to 1 part by mass with respect to 100 parts by mass of the mixture of siloxanes represented by the formula (IV) and the formula (IV) ′. In this way, a chain polysiloxane represented by the following formula (VII) is obtained. C in the formula (VII) represents an integer of 0 to 2000, and d represents an integer of 0 to 3000. The chain polysiloxane represented by the formula (VII) uses a compound represented by the formula (V) ′ as a terminal blocking agent.

  Next, the addition reaction will be described. First, in the presence of a Karstedt catalyst represented by the following formula (VII), a compound that generates a mesogen group having a structure represented by the above-described formula (II) and a polysiloxane having Si-H groups at both ends are combined. React with. Thereafter, the obtained reaction product (compound represented by the above formula (III)) and the chain polysiloxane represented by the formula (VII) are reacted in the presence of the Karstedt catalyst represented by the formula (VIII). React. As the Karstedt catalyst, a commercially available product may be used. For example, “Platinum (0) -1,3-divinyltetramethyldisiloxane complex” manufactured by Tokyo Chemical Industry Co., Ltd., Gelest. Inc. “SIP6831.2”, “SIP6831.2LC”, and the like are commercially available.

Examples of the compound that generates a mesogenic 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 is omitted. R ₆ represents an alkenyl group having 2 to 11 carbon atoms. Of the compounds that generate a mesogenic group having a structure represented by the formula (II), a compound represented by the following formula (IX) ′ or (IX) ″ is preferable.

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

  Specifically, the addition reaction is performed by the following two-stage reaction. First, with respect to the compound molar ratio 1 represented by the formula (IX), a polysiloxane having a Si—H group at both ends (formula (X)) is, for example, 1 to 20, preferably 4 to 10. The Karstedt catalyst is added at a rate of, for example, 10 to 100 ppm, preferably 10 to 50 ppm. Thereafter, the reaction is performed 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 performed in a solvent such as toluene as necessary. In this way, the compound represented by the above formula (III) is obtained by the first-stage 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). For example, the chain polysiloxane represented by the formula (VII) is added at a molar ratio of 0.1 to 1, preferably 0.2 to 1 with respect to the compound molar ratio 1 represented by the formula (III). The Karstedt catalyst is added, for example, in a proportion of 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 performed in a solvent such as toluene as necessary.

  The reaction in the second step may be carried out by isolating the compound represented by the formula (III), and after completion of the reaction in the first step, the compound represented by the formula (III) is not isolated and is added to the reaction mixture. The chain polysiloxane represented by (VII) may be added.

  Thus, for example, when the compound represented by the formula (IX) ′ is used as the compound represented by the formula (IX) and the tetramethyldisiloxane represented by the formula (X) ′ is used as the siloxane, A side-chain crystalline polysiloxane represented by the following formula (XI) (an example of a temperature-sensitive resin according to this embodiment) is obtained. X, y and z in formula (XI) are as described above, and a 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 an asymmetric olefin as an impurity 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 GPC, ¹ H-NMR, or the like, for example.

<Temperature sensitive adhesive>
Next, the temperature-sensitive adhesive according to one embodiment of the present invention will be described in detail. The temperature-sensitive adhesive of this embodiment contains the temperature-sensitive resin according to the above-described embodiment, and the adhesive strength is reduced at a temperature lower than the melting point of the temperature-sensitive resin. The temperature-sensitive adhesive of this embodiment contains a temperature-sensitive resin in which the temperature-sensitive resin is crystallized at a temperature lower than the melting point and the adhesive force is reduced. Therefore, when the temperature-sensitive adhesive is peeled from the adherend, if the temperature-sensitive adhesive is cooled to a temperature lower than the melting point of the temperature-sensitive resin, the temperature-sensitive resin is crystallized and the adhesive force is reduced. 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 pressure-sensitive adhesive force is restored by the fluidity of the temperature-sensitive resin. As a result, the temperature-sensitive adhesive of this embodiment can be used repeatedly.

  The temperature-sensitive adhesive of this embodiment preferably includes a polysiloxane having a Si—H group and a silanol-trimethylsilyl-modified MQ resin (hereinafter sometimes simply referred to as “MQ resin”).

  The polysiloxane having a Si—H group can be cross-linked with the temperature-sensitive resin to form a three-dimensional structure, 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 (XII) to (XII) ″. F in Formula (XII) represents an integer of 0 to 2000. G in Formula (XII) 'represents an integer of 2 to 200. In formula (XII) ″, h represents an integer of 0 to 5000, and i represents an integer of 2 to 2000. As the polysiloxane having a Si—H group, a commercially available product may be used. For example, “HMS-991”, “HMS-013”, “HMS-031”, “HMS-064”, “HMS-071”, “ HMS-064, HMS-082, HMS-151, HMS-501, DMS-H11, DMS-H21, DMS-H31, DMS-H41 (all of which are Gelest Etc.) are commercially available.

  The MQ resin functions as a cohesive force component in the temperature-sensitive adhesive of this embodiment. MQ resin has a structure represented by the following formula (XIII), formula (XIII) ', etc., and usually has good compatibility with the above-mentioned temperature-sensitive resin. A commercially available MQ resin may be used, for example, Gelest. “SQO-299”, “VQX-221” manufactured by Inc., “Silmer VQ20”, “Silmer VQ2012”, “Silmer VQ122XYL”, “Silmer VQ9XYL” manufactured by Siltech Corporation are commercially available.

  When the temperature sensitive adhesive of this embodiment contains the polysiloxane and Si resin which have Si-H group, content of each component is not specifically limited. For example, the polysiloxane having a 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 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 with respect to 100 parts by mass of the thermosensitive resin.

  The temperature-sensitive adhesive of this embodiment may be applied directly to an adherend, for example, or may be used in the form of a substrate-less sheet, and the usage form is not particularly limited. For example, when using the thermosensitive adhesive of this embodiment as a thermosensitive adhesive sheet, the thickness of the thermosensitive adhesive sheet is preferably 10 to 500 μm, more preferably 10 to 200 μm.

  The thermosensitive adhesive of this embodiment may be used in a tape form. When using the temperature sensitive adhesive of this embodiment as a temperature sensitive adhesive tape, the adhesive layer containing the temperature sensitive adhesive of this embodiment is laminated | stacked on the at least one surface of a base material. The substrate is preferably a film, and the film includes a sheet.

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

  The base material may have a single layer structure or a multilayer structure. The substrate usually has a thickness of about 5 to 500 μm. Furthermore, the substrate may be subjected to surface treatment such as corona discharge treatment, plasma treatment, blast treatment, chemical etching treatment, primer treatment, etc. for the purpose of improving the adhesion to the adhesive layer.

  The method for laminating the pressure-sensitive adhesive layer on at least one surface of the substrate is not particularly limited. For example, a method in which a coating solution obtained by adding a solvent to a temperature-sensitive adhesive is applied to one or both sides of a substrate by a coater or the like and dried. 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 causing a crosslinking reaction is usually added to the coating solution, and an inhibitor for suppressing the reaction before coating may be added. Thereby, an inhibitor and a Karstedt catalyst form a complex, and it can suppress that a crosslinking reaction arises in an adhesive layer. When the inhibitor is volatilized by heating above the boiling point of the inhibitor, a crosslinking reaction through the Karstedt catalyst proceeds. Examples of the inhibitor include 1-butyn-2-ol, 2-methyl-3-butyn-2-ol, 3,5-dimethyl-1-hexyn-3-ol, and 3-methyl-1-pentene-3. -Ol, phenylbutynol, 1-ethynyl-1-cyclohexanol and the like.

  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 inhibitor 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 configuration of the coating liquid is the same when the thermosensitive adhesive is directly applied to the adherend or used in the form of a substrate-less sheet.

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

  Furthermore, if the adhesive containing the temperature-sensitive adhesive of this embodiment is laminated | stacked on the one surface of a base material, another adhesive layer may be laminated | stacked 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 includes a polymer having tackiness. Examples of such a tacky polymer include natural rubber adhesives, synthetic rubber adhesives, styrene / butadiene latex-based adhesives, and acrylic adhesives.

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

<Temperature sensitive adhesive composition>
Next, the temperature-sensitive adhesive composition according to one embodiment of the present invention will be described in detail. The temperature-sensitive adhesive of this embodiment contains the temperature-sensitive resin according to one embodiment described above, a polysiloxane having a Si—H group, a silanol-trimethylsilyl-modified MQ resin, and a Karstedt catalyst. The above-mentioned inhibitor may be added as needed. Details of each component are as described above, and a description thereof will be omitted.

  As described above, the temperature-sensitive resin according to one embodiment of the present invention has excellent heat resistance and chemical resistance. The use of the temperature-sensitive adhesive containing such a temperature-sensitive resin is not particularly limited, and for example, it is suitably used as an 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-described embodiment, the 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 adhesive is not limited to the configuration containing the polysiloxane having an Si—H group and the MQ resin as long as it contains the above-mentioned temperature-sensitive resin. It can be composed of common materials used.

  EXAMPLES Hereinafter, although an Example and a comparative example are given and this invention is demonstrated concretely, this invention is not limited to these Examples.

(Synthesis Example 1: Synthesis of linear polysiloxane)
To a three-necked flask equipped with a stirring blade and a nitrogen inlet tube, 20 g of cyclic siloxane and 5 mg of end-capping agent were added. “Tetravinyltetramethylcyclotetrasiloxane (manufactured by Tokyo Chemical Industry Co., Ltd.)” was used as the cyclic siloxane, and “hexamethyldisiloxane (manufactured by Tokyo Chemical Industry Co., Ltd.)” was used as the end-capping agent. . Nitrogen was introduced into the mixture of cyclic siloxane and end-capping agent from a nitrogen introduction tube, and nitrogen bubbling was performed for 30 minutes with stirring. The nitrogen inlet tube was then removed from the mixture and the three neck flask was placed in an oil bath. As a base catalyst, 7 mg of “TETRAMETHYLAMMONIUM SILOX ANOLATE (manufactured by Tokyo Chemical Industry Co., Ltd.)” was added to a three-necked flask and stirred at 100 ° C. for 6 hours. Subsequently, in order to decompose | disassemble a catalyst, it heated up to 150 degreeC and stirred for further 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 55000 and a weight average molecular weight of 137000. The number average molecule and the weight average molecular weight were obtained by measuring the obtained chain polysiloxane by GPC and converting the obtained measured value into polystyrene.

(Synthesis Example 2: Synthesis of liquid crystal molecules (compounds that generate mesogenic groups))
In a flask equipped with a stir bar and fitted with a condenser, 20 g of “4-Allyloxybenzaldehyde (manufactured by Tokyo Chemical Industry Co., Ltd.)”, 18.4 g of “4-Butyllineline (manufactured by Tokyo Chemical Industry Co., Ltd.)”, and 40 g of ethanol was added. The flask was placed in an oil bath, heated to 80 ° C. with stirring using a magnetic stirrer, and reacted for 24 hours. The reaction mixture was then allowed to stand and cooled to room temperature, purified by recrystallization, and yellow crystals were collected by suction filtration. The recovered crystals were dried under reduced pressure at 100 ° C. for 4 hours to obtain a compound (A) that generates a mesogenic group represented by the formula (IX) ′. From the DSC measurement (10 ° C./min), the obtained compound (A) had a melting point of about 69 ° C. and a clearing point of about 53 ° C.

(Synthesis Example 3: Synthesis of liquid crystal molecules (compounds that generate mesogenic groups))
In a flask containing a stir bar and fitted with a condenser, 20 g of “4-Allyloxybenzaldehyde (manufactured by Tokyo Chemical Industry Co., Ltd.)”, 15.2 g of “p-Anisidine (manufactured by Tokyo Chemical Industry Co., Ltd.)”, and 40 g of toluene was added. The flask was placed in an oil bath, heated to 100 ° C. with stirring using a magnetic stirrer, and reacted for 12 hours. The reaction mixture was then allowed to stand and cooled to room temperature, purified by recrystallization, and yellow crystals were collected by suction filtration. The recovered crystals were dried under reduced pressure at 120 ° C. for 4 hours to obtain a compound (B) that generates a mesogenic group represented by the formula (IX) ″. From the DSC measurement (10 ° C./min), the obtained compound (B) had a melting point of about 112 ° C.

(Synthesis Example 4: Synthesis of mesogen unit)
In a three-necked flask equipped with a stirring blade and a thermometer, 45.8 g of “tetramethyldisiloxane (manufactured by Tokyo Chemical Industry Co., Ltd.)”, 10 g of the compound (A) obtained in Synthesis Example 2 and 82 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., 10 mg of a 20 mass% toluene solution of “platinum (0) -1,3-divinyltetramethyldisiloxane complex (manufactured by Tokyo Chemical Industry Co., Ltd.)” was added. Then, it stirred at 70 degreeC 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. Next, the reaction mixture in the three-necked flask was dropped into ethanol for purification by precipitation. The precipitate was collected by suction filtration and dried under reduced pressure at 80 ° C. to obtain a one-end reactive mesogen unit (A) ′ represented by the formula (III).

(Synthesis Example 5: Synthesis of mesogen unit)
Synthesis Example 4 except that 50.2 g of “tetramethyldisiloxane (manufactured by Tokyo Chemical Industry Co., Ltd.)”, 10 g of the compound (B) obtained in Synthesis Example 3 and 90.3 g of dehydrated toluene were used. A single-terminal reactive mesogen unit (B) ′ was obtained by the same procedure.

(Example 1: Synthesis of side-chain crystalline polysiloxane (temperature-sensitive resin))
In a three-necked flask containing a stirrer, 1 g of the chain polysiloxane obtained in Synthesis Example 1, 4.72 g of the mesogenic unit (A) ′ obtained in Synthesis Example 4, and 13.4 g of dehydrated toluene Was added. The three-necked flask was put in an oil bath and heated to 100 ° C. while stirring using a magnetic stirrer. When the temperature reached 100 ° C., 6 mg of a 20 mass% toluene solution of “platinum (0) -1,3-divinyltetramethyldisiloxane complex” was added. Then, it stirred at 100 degreeC for 24 hours. Next, 50 g of acetone heated to 60 ° C. was added to the resulting 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).

From the GPC measurement, the obtained side chain crystalline polysiloxane (1) had a number average molecular weight of 109000 and a weight average molecular weight of 281,000. The number average molecular weight and the weight average molecular weight were obtained by measuring the obtained side chain crystalline polysiloxane by GPC and converting the obtained measured values into polystyrene. ^From the integration ratio of ¹ H-NMR, the obtained side chain crystalline polysiloxane (1) contained vinylmethylsiloxane units at a ratio of about 10%. Further, from the DSC measurement (10 ° C./min), the obtained side chain crystalline polysiloxane (1) had a melting point of about 40 ° C.

  About the obtained side chain crystalline polysiloxane (1), heat resistance was evaluated by thermogravimetric analysis (TGA). Specifically, using a thermogravimetric analyzer “TG / DTA 6200” manufactured by Seiko Instruments Inc., the temperature was raised from 25 ° C. to 500 ° C. (10 ° C./min) under a nitrogen gas atmosphere, The mass change of the side chain crystalline polysiloxane (1) during the process was measured. Next, the temperature at which the mass became 98% with respect to the mass at 25 ° C., that is, the 2% mass decrease temperature was measured. It shows that it is excellent in heat resistance, so that this temperature is high. The results are shown in Table 1.

(Example 2: Synthesis of side chain crystalline polysiloxane (temperature-sensitive resin))
Side chain crystalline polysiloxane (2) is obtained in the same procedure as in Example 1 except that 4.43 g of mesogen unit (B) ′ obtained in Synthesis Example 5 and 12.7 g of dehydrated toluene are used. It was. In the same procedure as in Example 1, the number average molecular weight, the weight average molecular weight, the proportion of vinylmethylsiloxane units, and the melting point of the obtained side chain crystalline polysiloxane (2) were measured. The results are shown below.
Number average molecular weight: 97000
Weight average molecular weight: 270000
Percentage of vinylmethylsiloxane units: about 12%
Melting point: about 66 ° C

  The obtained side chain crystalline polysiloxane (2) was evaluated for heat resistance in the same procedure as in Example 1. The results are shown in Table 1.

(Comparative Example 1)
The heat resistance of the acrylic skeleton-containing thermosensitive resin having the following monomer composition was evaluated in the same procedure as in Example 1. 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 ° C.
Weight average molecular weight: 540000

  As shown in Table 1, it can be seen that the side-chain crystalline polysiloxane (temperature-sensitive resin) obtained in Examples 1 and 2 has a high 2% mass reduction temperature and has excellent heat resistance. On the other hand, it can be seen that the acrylic skeleton-containing temperature-sensitive resin obtained in Comparative Example 1 has a low 2% mass reduction temperature and poor heat resistance.

(Example 3: Production of temperature-sensitive adhesive sheet)
The obtained side chain crystalline polysiloxane (1), polysiloxane having a Si—H group, and MQ resin were mixed at a ratio shown in Table 2 to prepare a temperature-sensitive adhesive. The polysiloxane having an Si—H group and the MQ resin used are as follows.
Polysiloxane having Si—H group: “HMS-064” represented by the above formula (XII) ″ (manufactured by Gelest. Inc.)
MQ resin: “SQO-299” represented by the above formula (XIII) (manufactured by Gelest. Inc.)

  Toluene was added to 100 parts by mass of the obtained temperature-sensitive adhesive so that the solid content concentration would be 70% by mass. There, 0.5 parts by mass of the above-mentioned “platinum (0) -1,3-divinyltetramethyldisiloxane complex” in terms of solid content, and solid 2-methyl-3-butyn-2-ol as an inhibitor A coating solution was prepared by adding 1 part by mass in terms of minutes. The obtained coating solution was applied to one side of a polyethylene terephthalate film (thickness 75 μm), that is, the side subjected to fluorosilicone treatment. Subsequently, it heated at 120 degreeC for 10 minute (s), and the reactive site (vinyl group) of side chain crystalline polysiloxane and the functional group (Si-H group) of polysiloxane which has Si-H group were bridge | crosslinked. Thus, the temperature sensitive adhesive sheet in which the adhesive layer (thickness 30 micrometers) was formed was obtained.

(Example 4: Production of temperature-sensitive adhesive sheet)
As shown in Table 2, a temperature-sensitive adhesive sheet was obtained in the same procedure as in Example 3 except that the side chain crystalline polysiloxane (2) was used instead of the side chain crystalline polysiloxane (1). .

(Comparative Example 2: Production of temperature-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 content concentration was 30% by mass. A coating solution was prepared by mixing 5 parts by mass of tritylamine as an inhibitor and 1 part by mass of “PZ-33” (manufactured by Nippon Shokubai Co., Ltd.) as a crosslinking agent. The obtained coating solution was applied to one side of a polyethylene terephthalate film (thickness 50 μm), that is, the surface subjected to silicone treatment. Subsequently, it heated at 100 degreeC for 10 minute (s), and the temperature sensitive adhesive sheet in which the crosslinked adhesive layer (thickness 30 micrometers) was formed was obtained.

  About the temperature-sensitive adhesive sheet obtained in Examples 3 and 4 and Comparative Example 2, 180 ° peel strength and chemical resistance were evaluated by the following methods. The results are shown in Table 3.

<180 ° peel strength>
180 ° peel strength against polyimide in an atmosphere at 80 ° C. and 5 ° C. was measured in accordance with JIS Z0237. Specifically, the temperature-sensitive adhesive sheet was attached to non-alkali glass under the following conditions, and then peeled 180 ° using a load cell at a rate of 300 mm / min.
(80 ° C)
The temperature-sensitive adhesive sheet was attached to non-alkali glass in an 80 ° C. atmosphere, and the polyethylene terephthalate film was peeled off. Thereafter, a strip-shaped polyimide film (thickness 25 μm and width 25 mm) was stuck, left at 80 ° C. for 20 minutes, and peeled 180 °.
(5 ° C)
The temperature-sensitive adhesive sheet was attached to non-alkali glass in an 80 ° C. atmosphere, and the polyethylene terephthalate film was peeled off. Thereafter, a strip-shaped polyimide film (thickness 25 μm and width 25 mm) was stuck and allowed to stand at 80 ° C. for 20 minutes. Subsequently, after cooling to 5 degreeC and leaving still for 20 minutes, it peeled 180 degrees.

<Chemical resistance>
The temperature-sensitive adhesive sheets obtained in Examples 3 and 4 and Comparative Example 2 were cut into strips to obtain test pieces (2 cm × 5 cm). The obtained test piece was immersed in a chemical mixed solution containing 55% by mass of phosphoric acid, 25% by mass of acetic acid and 20% by mass of water, and allowed to stand at 70 ° C. for 15 minutes. After 15 minutes, the test piece was taken out from the chemical mixed solution and washed with water, and it was visually observed whether or not a whitened portion or a discolored portion was present on the thermosensitive adhesive sheet.

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

  Further, it can be seen that the temperature-sensitive adhesive sheets obtained in Examples 3 and 4 are excellent in chemical resistance, with no whitened portions or discolored portions even when immersed in a chemical mixed solution. On the other hand, when the thermosensitive adhesive sheet obtained in Comparative Example 2 is immersed in a chemical mixed solution, a whitened portion is generated, which indicates that the chemical resistance is poor.

Claims (9)

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 a hydrocarbon group having 1 to 10 carbon atoms the same or different. 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 mesogenic group having a structure represented by the following formula (II). m represents an integer of 2 to 10. n shows the integer of 1-100. x shows the integer of 0-2000. y shows the integer of 100-2000. z shows the integer of 1-1000.

In formula (II), R ₅ represents hydrogen, an aliphatic hydrocarbon group having 1 to 10 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, or a cyano group. The temperature-sensitive resin according to claim 1, wherein the mesogenic group has a structure represented by the following formula (II) ′ or (II) ″.

  The temperature-sensitive resin according to claim 1 or 2, wherein the melting point is 0 ° C or higher.   The temperature sensitive adhesive which contains the temperature sensitive resin in any one of Claims 1-3, and adhesive force falls at the temperature below melting | fusing point of this resin.   The temperature-sensitive adhesive according to claim 4, wherein the melting point is 0 ° C or higher.   The temperature-sensitive adhesive according to claim 4 or 5, further comprising a polysiloxane having a Si-H group and a silanol-trimethylsilyl modified MQ resin.   A temperature-sensitive adhesive sheet comprising the temperature-sensitive adhesive according to claim 4.   A temperature-sensitive adhesive tape, wherein an adhesive layer comprising the temperature-sensitive adhesive according to claim 4 is laminated on at least one surface of a substrate.   A temperature-sensitive adhesive composition comprising the temperature-sensitive resin according to claim 1, a polysiloxane having a Si—H group, a silanol-trimethylsilyl-modified MQ resin, and a Karstedt catalyst.