TW201819538A - Temperature sensitive resin, temperature sensitive adhesive and temperature sensitive adhesive composition - Google Patents

Abstract

The present invention provides a temperature sensitive resin having excellent heat resistance and chemical resistance, a temperature sensitive adhesive and a temperature sensitive adhesive composition containing the same. The temperature sensitive resin of the present invention is represented by the following formula (I), which crystallizes at a temperature lower than the melting point and shows fluidity at a temperature higher than the melting point. In formula (I), R1 represents the same or different hydrocarbon group having 1 to 10 carbon atoms, R2 represents a group having an alkenyl group, R3 represents a polymethylene group having 2 to 11 carbon atoms, R4 represents a mesogen group having a structure represented by the following formula (II), m represents an integer of 2 to 10, n represents an integer of 1 to 100, x represents an integer from 0 to 2000, y represents an integer of 100 to 2000, z represents an integer of 2 to 1000. In the formula (II), R5 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.

Description

   Temperature-sensitive resin, temperature-sensitive adhesive, and temperature-sensitive adhesive composition   

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

A thermosensitive resin having a thermosensitive property that reversibly exhibits a crystal state and a fluid state in response to a temperature change is known (for example, Patent Documents 1 and 2). Since thermosensitive resins are often used as adhesives, thermosensitive resins are required to have excellent heat resistance and chemical resistance.

    [Prior Art Literature]         [Patent Literature]    

Patent Document 1: Japanese Patent Laid-Open No. 2001-290138

Patent Document 2: Japanese Patent Application Laid-Open No. 2008-179744

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

The present inventors made intensive research in order to solve the above problems, and as a result, found a solution including the following configuration, and completed the present invention.

(1) A thermosensitive resin represented by the following formula (I), which crystallizes at a temperature lower than the melting point, and exhibits fluidity at a temperature higher than the melting point, In formula (I), R ₁ represents a hydrocarbon group having 1 to 10 carbon atoms which may be 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 mesogen group having a structure represented by the following formula (II). m represents an integer from 2 to 10. n represents an integer from 1 to 100. x represents an integer from 0 to 2000. y represents an integer from 100 to 2000. z represents an integer from 2 to 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 thermosensitive resin according to the above (1), wherein the mesogenic group has a structure represented by the following formula (II) 'or (II) ".

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

(4) A temperature-sensitive adhesive containing the temperature-sensitive resin according to any one of (1) to (3) above, and the adhesive force decreases at a temperature lower than the melting point of the resin.

(5) The temperature-sensitive adhesive according to (4) above, which has a melting point of 0 ° C or higher.

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

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

(8) A thermosensitive adhesive tape obtained by laminating an adhesive layer containing the thermosensitive adhesive according to any one of (4) to (6) on at least one surface of a substrate.

(9) A thermosensitive adhesive composition containing the thermosensitive resin according to any one of (1) to (3) above, a polysiloxane having a Si-H group, and silanol-trimethylol Silicon-based modified MQ resin, and Karstedt catalyst.

The thermosensitive resin according to the present invention exhibits excellent heat resistance and chemical resistance. This type of thermosensitive resin is suitable for use as a raw material of a thermosensitive adhesive and a thermosensitive adhesive composition.

    <Thermoplastic resin>    

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

In formula (I), R ₁ represents a hydrocarbon group having 1 to 10 carbon atoms which may be 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, ethyl, propyl, butyl, pentyl, and hexyl, and alkenyl groups such as vinyl, allyl, and butenyl. , Phenyl, benzyl, phenethyl, tolyl, and other aryl groups. The alkyl and alkenyl systems 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 has a reactive portion in the thermosensitive resin according to the embodiment. Preferred examples of R ₂ include alkenyl groups having 2 to 10 carbon atoms. Specific examples of R ₂ include vinyl, allyl, butenyl, pentenyl, hexenyl, heptenyl, octenyl, nonenyl, and decenyl.

In the formula (I), R ₃ represents a polymethylene group having 2 to 11 carbon atoms. The side chain portion containing this 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 embodiment. The thermosensitive resin according to this embodiment is crystallized by adjusting the side chain derived from the compound represented by the following formula (III) to an ordered arrangement by using an intermolecular force or the like. Specific examples of the polymethylene group having 2 to 11 carbon atoms include dimethylene, trimethylene, tetramethylene, pentamethylene, and hexamethylene.

In the formula (I), R ₄ represents a mesogenic group having a structure represented by the following formula (II). The mesogenic group refers to a group that contributes to the rigidity and high orientation 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 methyl, ethyl, propyl, butyl, octyl, and decyl. 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, ethoxy, butoxy, octyloxy, decoxy, diethoxy, triethoxy, and tetraethoxy. . R ₅ is preferably n-butyl or methoxy. Mesogenic groups having a structure represented by formula (II) in which R ₅ is n-butyl or methoxy are shown in the following formulae (II) 'and (II) ".

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

In formula (I), m represents an integer of 2 to 10, an integer of 2 to 6 is preferable, and an integer of 2 to 3 is more preferable. n represents an integer from 1 to 100, an integer from 2 to 40 is preferable, and an integer from 2 to 10 is more preferable.

The weight-average molecular weight of the thermosensitive resin of the embodiment is not particularly limited. The weight-average molecular weight of the thermosensitive resin of this embodiment is preferably 100,000 or more, more preferably 150,000 or more, 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 thermosensitive 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 in association with crystallization. "Melting point" means the temperature at which a particular part of the polymer that is initially integrated into an ordered arrangement becomes disordered by some equilibrium process, which means that by differential scanning calorimetry (DSC), A value measured under the condition of ° C / minute. The temperature-sensitive resin of this embodiment has a melting point of preferably 0 ° C or higher, more preferably 10 ° C or higher, more preferably 120 ° C or lower, and more preferably 100 ° C or lower.

The temperature-sensitive resin of this embodiment crystallizes at a temperature lower than the melting point, and undergoes a phase change at a temperature higher than the melting point to exhibit fluidity. That is, the temperature-sensitive resin of the embodiment has temperature-sensitivity that reversibly shows a crystalline state and a flowing state in response to a temperature change.

As shown in formula (I), the thermosensitive resin according to this embodiment has a polysiloxane having a siloxane bond in the main chain. Specifically, the thermosensitive resin according to this embodiment is a polyorganic compound having R ₂ as a reactive site and a side chain derived from a compound represented by formula (III) as a crystalline site and having a silicone skeleton. Siloxane. With such a structure, excellent heat resistance and chemical resistance are exhibited. That is, since conventional thermosensitive resins generally have an acrylic skeleton, they have undergone severe hydrolysis under a chemical environment such as an alkali or a high-temperature environment of 200 ° C. or higher. Therefore, conventional thermosensitive resins cannot be used in the above-mentioned environment.

On the other hand, as described above, the temperature-sensitive resin of the embodiment has a silicone skeleton. As a result, it exhibits better heat resistance and chemical resistance than conventional thermosensitive resins having an acrylic skeleton. The thermosensitive resin of this embodiment can be used even in a high temperature environment such as 250 ° C or higher.

Next, an example of the method of manufacturing the thermosensitive resin of this embodiment is demonstrated. The temperature-sensitive resin of this embodiment is obtained, for example, by the following method: a chain-type polysiloxane is obtained by ring-opening polymerization of a cyclic siloxane, and the chain-type polysiloxane is obtained by an addition reaction A side chain (a side chain derived from the compound represented by the formula (III)) derived from a siloxane and a mesogen group is introduced. A specific compound is exemplified below to describe one embodiment of the production method.

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 this embodiment, the compounds represented by the following formulae (IV) and (IV) 'will be described as examples.

An octamethylcyclotetrasiloxane represented by the formula (IV), a tetramethyltetravinylcyclotetrasiloxane represented by the formula (IV) ′, and the following formula (V) as a capping agent The shown chain siloxane may react in the presence of a base catalyst represented by the following formula (VI).

R ₁ in formula (V) is the same or different hydrocarbon group having 1 to 10 carbon atoms as described above. The hydrocarbon group having 1 to 10 carbon atoms is not particularly limited, and examples thereof include alkyl groups such as methyl, ethyl, propyl, butyl, pentyl, and hexyl, and alkenyl groups such as vinyl, allyl, and butenyl. , Phenyl, benzyl, phenethyl, tolyl, and other aryl groups. The alkyl group and alkenyl group may have a linear structure or a branched structure. a represents an integer of 0 to 1000. Examples of the compound represented by the formula (V) include compounds represented by the following formulae (V) 'and (V) ". As the compound represented by the formula (V)', For example, "1,1,4,4-tetramethyl-1,1,4,4-tetravinyldisiloxane" manufactured by Tokyo Chemical Industry Co., Ltd., and "DMS-V21" manufactured by Gelest. Inc. Commercially available. As compounds represented by (V), for example, "KF-96" manufactured by Shin-Etsu Chemical Industry Co., Ltd., "hexamethyldisilazane" manufactured by Tokyo Chemical Industry Co., Ltd., and "Octamethyltrisiloxane" and others are commercially available.

Among the compounds represented by the following formula (VI) used as a base catalyst, b represents an integer of 1 to 8. As a compound represented by formula (VI), for example, "TETRAMETHYLAMMONIUM SILOXANOLATE" (tetramethylammonium silanol) manufactured by Gelest. Inc. is commercially available.

The base catalyst is not limited to the compound represented by the formula (VI), and other base catalysts may be used. Examples of other base catalysts include tetrabutylammonium silanol, tetramethylphosphonium silanol, tetrabutylphosphonium silanol, tetramethylantimonyl silanol, tetrabutylantimonyl silanol, tetrabutyl Silanes such as silanols, trimethylphosphosilanols, triethylphosphoranyl alcohols, and other basic organic compounds, such as silanols, potassium silanols, cesium silanols, etc. Alcohol and so on.

The ring-opening polymerization is performed by making octamethylcyclotetrasiloxane represented by formula (IV), tetramethyltetravinylcyclotetrasiloxane represented by formula (IV) ', and formula (V) The mixture of the capping agent and the base catalyst represented by formula (VI) is, for example, about 0 to 120 ° C, preferably about 70 to 120 ° C, and the reaction is about 0.1 to 48 hours, and about 0.5 to 24 hours. good. If necessary, the reaction may be carried out in a solvent such as toluene.

The mixing ratio of the octamethylcyclotetrasiloxane represented by the formula (IV) and the tetramethyltetravinylcyclotetrasiloxane represented by the formula (IV) 'is not particularly limited. For example, the silicone represented by the formula (IV) and the silicone represented by the formula (IV) 'are preferably mixed at a molar ratio of 0: 1 to 5: 1 and 0: 1 to 2: 1. The capping agent is added in a proportion of 0.00001 to 30 parts by mass based on 100 parts by mass of the mixture of the siloxanes represented by formula (IV) and formula (IV) '. The base catalyst is added at a ratio of 0.0000001 to 1 part by mass based on 100 parts by mass of the mixture of the siloxanes represented by the formula (IV) and the formula (IV) '. Thus, a chain polysiloxane represented by the following formula (VII) was obtained. C in formula (VII) represents an integer from 0 to 2000, and d represents an integer from 0 to 3000. The chain-type polysiloxane represented by the formula (VII) uses a compound represented by the formula (V) 'as an end-capping agent.

Next, an addition reaction is demonstrated. First, a compound generating a mesogenic group having a structure represented by the formula (II) and a polysiloxane having Si-H groups at both ends are reacted in the presence of a Karstedt catalyst represented by the following formula (VIII). Thereafter, the obtained reactant (the compound represented by the above formula (III)) and the chain polysiloxane represented by the formula (VII) are reacted in the presence of a Karstedt catalyst represented by the formula (VIII). As the Karstedt catalyst, commercially available products such as "platinum (0) -1,3-divinyltetramethyldisilaxane complex" manufactured by Tokyo Chemical Industry Co., Ltd., and "SIP6831 manufactured by Gelest. .2 "," SIP6831.2LC "and other 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 description thereof is omitted. R ₆ represents an alkenyl group having 2 to 11 carbon atoms. Among 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 preferred.

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

The addition reaction specifically proceeds through the following two-stage reaction. First, with respect to the compound represented by the formula (IX) with a molar ratio of 1, the polysiloxane having the Si-H group at both ends (formula (X)) has a molar ratio of, for example, 1 to 20, and preferably 4 to 10. The ratio of the ratio of addition is Karstedt's catalyst, for example, 10 to 100 ppm, preferably 10 to 50 ppm. Thereafter, the reaction is carried out at about 40 to 110 ° C, preferably about 50 to 70 ° C, for about 1 to 48 hours, and preferably about 3 to 12 hours. If necessary, the reaction may be performed in a solvent such as toluene. Thus, in the reaction at the first stage, a compound represented by the formula (III) is obtained.

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). With respect to the compound represented by the formula (III) with a molar ratio of 1, the chain-like polysiloxane represented by the formula (VII) is added at a molar ratio of, for example, 0.1 to 1, and the Karstedt catalyst is, for example, 10 to 100 ppm is added at a ratio of 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, and preferably about 3 to 6 hours. If necessary, the reaction may be performed in a solvent such as toluene.

The second-stage reaction can be performed by separating the compound represented by the formula (III), or after the completion of the first-stage reaction, the compound represented by the formula (VII) can be added to the reaction mixture without isolating the compound represented by the formula (III). Polysiloxane.

Thus, for example, when a compound represented by the formula (IX) 'is used as the compound represented by the formula (IX) and a tetramethyldisilaxane represented by the formula (X)' is used as the siloxane, the following is obtained The side chain crystalline polysiloxane represented by the formula (XI) (an example of the thermosensitive resin according to the embodiment) is described. X, y, and z of the formula (XI) are as described above, and descriptions thereof are omitted.

After the reaction, the reactant may be used directly as a thermosensitive resin, or the reactant may be purified and then used as a thermosensitive resin. Examples of the purification method include a method of removing an asymmetric olefin as an impurity by washing with a solvent and reprecipitation. The solvent is not particularly limited, and examples thereof include acetone, a mixed solvent of toluene, and acetone. Whether or not impurities have been removed can be confirmed by, for example, GPC, ¹ H-NMR, or the like.

    <Thermal adhesive>    

Next, a temperature-sensitive adhesive according to an embodiment of the present invention will be described in detail. The temperature-sensitive adhesive of this embodiment contains the temperature-sensitive resin of the above-mentioned one embodiment, and the adhesive force decreases at a temperature lower than the melting point of the temperature-sensitive resin. The temperature-sensitive adhesive according to the embodiment includes a temperature-sensitive resin that crystallizes at a temperature lower than the melting point, thereby reducing the adhesive force. Therefore, when the temperature-sensitive adhesive is peeled 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 is crystallized to reduce the adhesive force. On the other hand, when the temperature-sensitive adhesive is heated to a temperature above the melting point of the temperature-sensitive resin, the temperature-sensitive resin exhibits fluidity to restore the adhesive force. As a result, the temperature-sensitive adhesive of this embodiment can be repeatedly used.

In the temperature-sensitive adhesive of the present embodiment, a modified silicone resin (hereinafter, sometimes simply referred to as "MQ resin") containing a polysiloxane containing Si-H group and a silanol-trimethylsilyl group is used as good.

The polysiloxane having a Si-H group can undergo a cross-linking reaction with the thermosensitive resin to three-dimensionally, and can provide cohesive force to the thermosensitive resin. As a result, it is possible to further improve the adhesiveness of the thermosensitive adhesive. The polysiloxane having a Si-H group is not particularly limited, and examples thereof include compounds represented by the following formulae (XII) to (XII) ". F in the formula (XII) represents an integer of 0 to 2000. G in the formula (XII) 'represents an integer from 2 to 200. h in the formula (XII) "represents an integer from 0 to 5000, and i represents an integer from 2 to 2000. Commercial products such as "HMS-991", "HMS-013", "HMS-031", "HMS-064", "HMS-071", "HMS" can be used as the polysiloxane having a Si-H group. -064 "," HMS-082 "," HMS-151 "," HMS-501 "," DMS-H11 "," DMS-H21 "," DMS-H31 "," DMS-H41 "(all are Gelest. Inc.) and other commercially available.

The MQ resin functions as a cohesive component in the temperature-sensitive adhesive of the embodiment. The MQ resin has a structure represented by the following formula (XIII), formula (XIII) 'and the like, and generally has good compatibility with the above-mentioned thermosensitive resin. As the MQ resin, commercially available products such as "SQO-299", "VQX-221" manufactured by Gelest.Inc, "Silmer VQ20", "Silmer VQ2012", "Silmer VQ122XYL", "Silmer VQ9XYL" manufactured by Siltech Corpration can be used. , Etc. are commercially available.

In the case where the temperature-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 content of the polysiloxane having a Si-H group is preferably 0.001 to 1,000 parts by mass, and more preferably 0.01 to 500 parts by mass with respect to 100 parts by mass of the thermosensitive resin. The content of the MQ resin relative to 100 parts by mass of the thermosensitive resin is preferably 10 to 1,000 parts by mass, and more preferably 20 to 500 parts by mass.

The temperature-sensitive adhesive of this embodiment can be directly applied to an adherend, for example, and can also be used in the form of a sheet without a substrate, and the use form is not particularly limited. For example, when the temperature-sensitive adhesive of the embodiment is used as a temperature-sensitive adhesive sheet, the thickness of the temperature-sensitive adhesive sheet is preferably 10 to 500 μm, and more preferably 10 to 200 μm.

The temperature-sensitive adhesive of this embodiment can be used in the form of a tape. 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 at least one surface of a base material. The substrate is preferably a film, and the film also includes a sheet.

Examples of the constituent material of the substrate include polyethylene, polyethylene terephthalate, polyethylene naphthalate, polypropylene, polyester, polyamide, polyimide, polycarbonate, Synthetic resins such as ethylene vinyl acetate copolymer, ethylene ethyl acrylate copolymer, ethylene polypropylene copolymer, polyvinyl chloride, and polyetheretherketone.

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

A method of laminating an adhesive layer on at least one surface of the substrate is not particularly limited. Examples thereof include a method in which a coating liquid obtained by adding a solvent to a thermosensitive 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 bar coater.

In the coating solution, a Karstedt catalyst for a crosslinking reaction may be generally added, and an inhibitor for suppressing a reaction before coating may be added. Thereby, the inhibitor forms a complex with the Karstedt catalyst, and the occurrence of a cross-linking reaction in the adhesive layer can be suppressed. When the inhibitor is heated above the boiling point of the inhibitor to volatilize the inhibitor, a cross-linking reaction via a Karstedt catalyst occurs. 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-penten-3-ol, phenylbutynol, 1-acetylene-1-cyclohexanol, and the like.

The Karstedt catalyst is added to the thermosensitive resin so that the concentration of platinum is preferably a concentration of 1 to 1000 ppm. On the other hand, the inhibitor is added in a proportion of 1 to 5 parts by mass relative to 100 parts by mass of the thermosensitive resin. The configuration of the coating liquid is the same in the case of using the thermosensitive adhesive directly on the adherend and using it, or the case of using it in the form of a sheet without a substrate.

The adhesive layer has a thickness of preferably 1 to 100 μm, more preferably 5 to 80 μm, and even more preferably 10 to 60 μm. When the adhesive layer is laminated on both sides of the substrate, the thickness of the adhesive layer may be the same or different, and the composition of the thermosensitive adhesive forming the adhesive layer may be the same or different.

In addition, as long as the adhesive containing the temperature-sensitive adhesive of the embodiment is laminated on one surface of the substrate, another 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 side. The pressure-sensitive adhesive contains a polymer having adhesiveness. Examples of such adhesive polymers include natural rubber adhesives, synthetic rubber adhesives, styrene / butadiene latex-based adhesives, and acrylic adhesives.

Preferably, the release film is laminated 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 having a surface coated with a release agent such as fluorosilane.

    <Thermal adhesive composition>    

Next, a temperature-sensitive adhesive composition according to an embodiment of the present invention will be described in detail. The temperature-sensitive adhesive of this embodiment contains the temperature-sensitive resin of the above-mentioned one embodiment, a polysiloxane having a Si-H group, a silanol-trimethylsilyl-modified MQ resin, and a Karstedt catalyst. . If necessary, the above-mentioned inhibitors can be added. The details of each component are as described above, and descriptions thereof are omitted.

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

The present invention is not limited to the above-mentioned embodiments, and various changes can be made without departing from the gist of the present invention. For example, in one embodiment described above, a temperature-sensitive adhesive containing a temperature-sensitive resin, a polysiloxane having a Si-H group, and an MQ resin will be described as an example. However, as long as the temperature-sensitive adhesive contains the above-mentioned temperature-sensitive resin, it is not limited to a structure containing a polysiloxane having an Si-H group and an MQ resin, and may also be used in a so-called silicone-based adhesive. Composition of general materials.

    [Example]    

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

    (Synthesis Example 1: Synthesis of Chain Polysiloxane)    

In a three-necked flask equipped with a stirring blade and a nitrogen introduction tube, 20 g of cyclic siloxane and 5 mg of a blocking agent were added. "Tetravinyltetramethylcyclotetrasiloxane (manufactured by Tokyo Chemical Industry Co., Ltd.)" was used as the cyclic siloxane system, and "hexamethyldisiloxane (Tokyo Chemical Industry Co., Ltd. ( Share) system) ". Nitrogen was introduced into the mixture of the cyclic siloxane and the capping agent from the nitrogen introduction tube, and nitrogen bubbling was performed for 30 minutes while stirring. Next, the nitrogen introduction tube was removed from the mixture, and the three-necked flask was placed in an oil bath. As a base catalyst, 7 mg of "tetramethylammonium silanol (manufactured by Tokyo Chemical Industry Co., Ltd.)" was added to a three-necked flask and stirred at 100 ° C for 6 hours. Next, the temperature was raised to 150 ° C. to decompose the catalyst, and the mixture was stirred for another 3 hours. After completion of the reaction, it was cooled to room temperature to obtain a chain-type polysiloxane represented by the formula (VII). From the GPC measurement, it was found that the obtained chain polysiloxane has a number average molecular weight of 55,000 and a weight average molecular weight of 137,000. The number-average molecular weight and the weight-average molecular weight are obtained by measuring the obtained linear polysiloxane with GPC, and converting the obtained measurement values into polystyrene.

    (Synthesis Example 2: Synthesis of Liquid Crystal Molecules (Compounds Forming Mesogenic Groups))    

To a flask equipped with a stir bar and a cooling tube, 20 g of "4-allyloxybenzaldehyde (manufactured by Tokyo Chemical Industry Co., Ltd.)" and 18.4 g of "4-butylaniline (Tokyo Chemical Industry Co., Ltd. )) And 40g of ethanol. The flask was placed in an oil bath, and the temperature was raised to 80 ° C. with stirring using a magnetic stirrer, and the reaction was carried out for 24 hours. Next, the reaction mixture was allowed to stand, cooled to room temperature, purified by recrystallization, and yellow crystals were recovered by suction filtration. The recovered crystal was dried under reduced pressure at 100 ° C for 4 hours to obtain a mesogenic group-forming compound (A) represented by the formula (IX) '. It was found from DSC measurement (10 ° C / min) that 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 (Mesogenic Compounds))    

To a flask equipped with a stir bar and a cooling tube, 20 g of "4-allyloxybenzaldehyde (manufactured by Tokyo Chemical Industry Co., Ltd.)" and 15.2 g of "p-aminoanisole (Tokyo Chemical Industry Co., Ltd.) (Product)) "and 40 g of toluene. The flask was placed in an oil bath, and the temperature was raised to 100 ° C. with stirring using a magnetic stirrer, and the reaction was performed for 12 hours. Next, the reaction mixture was allowed to stand, cooled to room temperature, purified by recrystallization, and yellow crystals were recovered by suction filtration. The recovered crystals were dried under reduced pressure at 120 ° C for 4 hours to obtain a mesogen-forming compound (B) represented by the formula (IX). According to DSC measurement (10 ° C / min), it was found that the obtained compound (B) Has a melting point of about 112 ° C.

    (Synthesis Example 4: Synthesis of Mesogenic Unit)    

In a three-necked flask equipped with a stirring blade and a thermometer, 45.8 g of "tetramethyldisilazane (manufactured by Tokyo Chemical Industry Co., Ltd.)", 10 g of the compound (A) obtained in Synthesis Example 2, and 82 g were added. Of dehydrated toluene. The three-necked flask was placed in an oil bath and heated to 70 ° C while stirring. When it reached 70 ° C., 10 mg of a 20% by mass toluene solution of “platinum (0) -1,3-divinyltetramethyldisilaxane complex (manufactured by Tokyo Chemical Industry Co., Ltd.)” was added. Then, it stirred at 70 degreeC for 24 hours. Next, a three-necked flask was equipped with a Dean Starke device, and heated at 100 ° C for 3 hours to recover unreacted tetramethyldisilazane. Next, the reaction mixture in the three-necked flask was added dropwise to ethanol to carry out precipitation purification. The precipitate was recovered by suction filtration and dried under reduced pressure at 80 ° C to obtain a single-terminal reactive mesogen unit (A) 'represented by the formula (III).

    (Synthesis Example 5: Synthesis of Mesogenic Unit)    

50.2 g of "tetramethyldisilazane (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. The same procedure as in Synthesis Example 4 gave a single-terminal reactive mesogen unit (B) '.

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

In a three-necked flask equipped with a stirrer, 1 g of the chain polysiloxane obtained in Synthesis Example 1, 4.72 g of the mesogenic unit (A) 'obtained in Synthesis Example 4, and 13.4 g of dehydrated toluene were added. . The three-necked flask was placed in an oil bath, and the temperature was raised to 100 ° C while stirring using a magnetic stirrer. When it reached 100 ° C, 6 mg of a "platinum (0) -1,3-divinyltetramethyldisilaxane complex" in 20% by mass of a toluene solution was added. Then, it stirred at 100 degreeC for 24 hours. Next, 50 g of acetone heated to 60 ° C. was added to the obtained reaction mixture and stirred. The solvent was removed by decantation, and the operation 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).

GPC measurement revealed that the obtained side chain crystalline polysiloxane (1) had a number average molecular weight of 109,000 and a weight average molecular weight of 281,000. The number average molecular weight and the weight average molecular weight are obtained by measuring the obtained side chain crystalline polysiloxane with GPC, and converting the obtained measurement values into polystyrene conversion. From the integral ratio of ¹ H-NMR, it was found that the obtained side chain crystalline polysiloxane (1) contained a vinyl methylsiloxane unit in a proportion of about 10%. In addition, it was found from DSC measurement (10 ° C / min) that the obtained side chain crystalline polysiloxane (1) had a melting point of about 40 ° C.

About the obtained side chain crystalline polysiloxane (1), the heat resistance was evaluated by thermogravimetric analysis (TGA). Specifically, using a thermogravimetric analysis device "TG / DTA 6200" manufactured by Seiko Instruments Inc., the temperature was increased from 25 ° C to 500 ° C (10 ° C / min) in a nitrogen atmosphere, and the side chain crystalline polymerization in the process was measured. Changes in the mass of the siloxane (1). Next, the temperature at which the mass reached 98% relative to the mass at 25 ° C was measured, that is, the temperature at which the mass was reduced by 2%. The higher the temperature, the better the heat resistance. The results are shown in Table 1.

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

Except that 4.43 g of the mesogenic unit (B) 'obtained in Synthesis Example 5 and 12.7 g of dehydrated toluene were used, the same procedure as in Example 1 was used to obtain a side chain crystalline polysiloxane (2 ). In the same procedure as in Example 1, the number average molecular weight, the weight average molecular weight, the ratio of the vinylmethylsiloxane unit, and the melting point of the obtained side chain crystalline polysiloxane (2) were measured. The results are shown below.

Number average molecular weight: 970000

Weight average molecular weight: 270,000

Proportion of vinyl methylsiloxane unit: about 12%

Melting point: about 66 ° C

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

    (Comparative example 1)    

About the thermosensitive resin containing the acrylic skeleton which has the following monomer composition, the heat resistance was evaluated by the same procedure as 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 (thermosensitive resin) obtained in Examples 1 and 2 has a high temperature at which the mass is reduced by 2% and has excellent heat resistance. On the other hand, it can be seen that the temperature of the 2% mass reduction of the temperature-sensitive resin containing an acrylic skeleton obtained in Comparative Example 1 was low, and the heat resistance was poor.

    (Example 3: Production of a temperature-sensitive adhesive sheet)    

The obtained side chain crystalline polysiloxane (1), a polysiloxane having a Si-H group, and an MQ resin were mixed at a ratio shown in Table 2 to prepare a thermosensitive adhesive. The Si-H group-containing polysiloxane and MQ resin used are shown below.

Polysiloxane having a Si-H group: "HMS-064" (manufactured by Gelest.inc) represented by the above formula (XII) "

MQ resin: "SQO-299" (manufactured by Gelest.inc) shown by the above formula (XIII)

To 100 parts by mass of the obtained thermosensitive adhesive, toluene was added so that the solid content concentration was 70% by mass. The above-mentioned "platinum (0) -1,3-divinyltetramethyldisilaxane complex" in a ratio of 0.5 parts by mass in terms of solid content was added thereto, and the content was converted into solid content as an inhibitor 2-methyl-3-butyn-2-ol was used in a proportion of 1 part by mass to prepare a coating liquid. The obtained coating liquid was applied to one side of a polyethylene terephthalate film (thickness: 75 μm), that is, the side subjected to the fluorosiloxane treatment. Next, it heated at 120 degreeC for 10 minutes, and the reactive part (vinyl group) of the side chain crystalline polysiloxane was crosslinked with the functional group (Si-H group) of the polysiloxane containing Si-H group. Thus, a temperature-sensitive adhesive sheet having an adhesive layer (thickness: 30 μm) was obtained.

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

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

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

To 100 parts by mass of the acrylic skeleton-containing thermosensitive resin obtained in Comparative Example 1, toluene was added so that the solid content concentration was 30% by mass. 5 parts by mass of trityl amine as an inhibitor and 1 part by mass of "PZ-33" (manufactured by Nippon Catalysts) were mixed as a crosslinking agent to prepare a coating solution. The obtained coating liquid was applied to one side of a polyethylene terephthalate film (thickness: 50 μm), that is, the side subjected to the siloxane treatment. Next, it heated at 100 degreeC for 10 minutes, and obtained the thermosensitive adhesive sheet which formed the crosslinked adhesive layer (thickness 30 micrometers).

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

    <180 ° peeling strength>    

The 180 ° peeling strength to polyimide in an environment of 80 ° C. and 5 ° C. was measured according to JIS Z0237. Specifically, the temperature-sensitive adhesive sheet was bonded to an alkali-free glass under the following conditions, and then peeled 180 ° at a speed of 300 mm / minute using a load sensor.

    (80 ℃)    

The thermosensitive adhesive sheet was bonded to an alkali-free glass at 80 ° C, and the polyethylene terephthalate film was peeled off. Then, a short strip-shaped polyfluorene imide film (25 μm in thickness and 25 mm in width) was bonded, and it was left to stand at 80 ° C. for 20 minutes and peeled at 180 °.

    (5 ℃)    

The thermosensitive adhesive sheet was bonded to an alkali-free glass at 80 ° C, and the polyethylene terephthalate film was peeled off. Then, a short strip-shaped polyimide film (thickness: 25 μm and width: 25 mm) was attached, and left at 80 ° C. for 20 minutes. Next, it cooled to 5 degreeC, and left it for 20 minutes, and peeled at 180 degree.

    <Drug resistance>    

The thermosensitive adhesive sheets obtained in Examples 3 and 4 and Comparative Example 2 were cut into short strips to obtain test pieces (2 cm × 5 cm). The obtained test piece was immersed in a medicine mixed solution containing 55% by mass of phosphoric acid, 25% by mass of acetic acid, and 20% by mass of water, and left at 70 ° C for 15 minutes. After 15 minutes, the test piece was taken out from the drug mixture solution and washed with water, and visual inspection was performed to observe whether there was a whitened part or a discolored part on the thermosensitive adhesive sheet.

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

In addition, it was found that the temperature-sensitive adhesive sheets obtained in Examples 3 and 4 did not cause whitening or discoloration even when immersed in a drug solution mixture, and had excellent chemical resistance. On the other hand, it was found that the temperature-sensitive adhesive sheet obtained in Comparative Example 2 had a whitened portion when immersed in a drug solution, and had poor chemical resistance.

Claims (9)

A thermosensitive resin represented by the following formula (I), which crystallizes at a temperature lower than the melting point, and exhibits fluidity at a temperature higher than the melting point, In formula (I), R ₁ represents the same or different hydrocarbon group having 1 to 10 carbon atoms, R ₂ represents a group having an alkenyl group, R ₃ represents a polymethylene group having 2 to 11 carbon atoms, and R ₄ represents having the following The mesogenic group of the structure represented by formula (II), m represents an integer from 2 to 10, n represents an integer from 1 to 100, x represents an integer from 0 to 2000, y represents an integer from 100 to 2000, and z represents 1 to 1000. Integer 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 thermosensitive resin according to item 1 of the scope of patent application, wherein the mesogenic group has a structure represented by the following formula (II) 'or (II) ",     The temperature-sensitive resin according to item 1 or 2 of the patent application scope, wherein the melting point is 0 ° C or higher.         A temperature-sensitive adhesive containing the temperature-sensitive resin according to any one of claims 1 to 3 of the patent application scope, and the adhesive force is reduced at a temperature lower than the melting point of the resin.         The temperature-sensitive adhesive according to item 4 of the scope of patent application, wherein the melting point is 0 ° C or higher.         The temperature-sensitive adhesive according to item 4 or 5 of the patent application scope, 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 described in any one of claims 4 to 6 of the scope of patent application.         A temperature-sensitive adhesive tape is formed by laminating an adhesive layer containing the temperature-sensitive adhesive described in any one of claims 4 to 6 on the at least one surface of a substrate.         A temperature-sensitive adhesive composition containing the temperature-sensitive resin according to any one of claims 1 to 3, a polysiloxane having a Si-H group, and a silanol-trimethylsilyl group. Modified MQ resin and Karstedt catalyst.