TW201821542A - Temperature sensitive resin, temperature sensitive adhesive and temperature sensitive adhesive composition - Google Patents

Abstract

The present invention provides a sensitive thermosensitive resin having excellent heat resistance, excellent hemical resistance and high cohesive strength, and a temperature sensitive adhesive and a temperature sensitive adhesive composition having the same. The temperature-sensitive resin according to 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 equal to or higher than the melting point. In the 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 linear alkyl group having 12 to 50 carbon atoms. m represents an integer of 2 to 10. n represents an integer of 1 to 100. x represents an integer of 0 to 2000. y represents an integer of 100 to 2000. z represents an integer of 1 to 1000.

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.

Thermosensitive resins are known that have thermosensitive properties that reversibly display crystal states and fluid states in response to temperature changes (for example, Patent Documents 1 and 2). Since thermosensitive resins are mostly used as adhesives, they are expected to have excellent heat resistance and chemical resistance, and high cohesion is also required.

    [Prior technical 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 high cohesive force, and a thermosensitive adhesive and a thermosensitive adhesive composition containing the thermosensitive resin.

The present inventors devoted themselves to research in order to solve the above-mentioned problems, and as a result, found a solution including the following technical solutions, 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 linear alkyl group having 12 to 50 carbon atoms. 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 1 to 1000.

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

(3) A temperature-sensitive adhesive containing the temperature-sensitive resin according to (1) or (2) above, and the adhesive force is reduced at a temperature lower than the melting point of the resin.

(4) The temperature-sensitive adhesive according to (3) above, which has a melting point of 0 ° C or higher.

(5) The temperature-sensitive adhesive according to the above (3) or (4), further comprising a polysiloxane having a Si-H group and a silanol-trimethylsilyl-modified MQ resin.

(6) A thermosensitive adhesive sheet comprising the thermosensitive adhesive according to any one of (3) to (5) above.

(7) A thermosensitive adhesive tape obtained by laminating an adhesive layer containing the thermosensitive adhesive according to any one of (3) to (5) on at least one surface of a substrate.

(8) A thermosensitive adhesive composition containing the thermosensitive resin according to the above (1) or (2), a polysiloxane having a Si-H group, and a silanol-trimethylsilyl group Performance MQ resin, and Karstedt catalyst.

According to the thermosensitive resin of the present invention, excellent heat resistance and chemical resistance can be exhibited, and high cohesion can be exhibited. Such a thermosensitive resin can be suitably used 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; alkenyl groups such as vinyl, allyl, and butenyl ; Aryl groups such as phenyl, benzyl, phenethyl, tolyl, etc .; The alkyl group and 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 thermosensitive resin according to the embodiment. Preferred examples of R ₂ include a group having an alkenyl group having 2 to 10 carbon atoms. Specific examples of R ₂ include vinyl, allyl, butenyl, pentenyl, hexenyl, heptenyl, octenyl, nonenyl, and decenyl.

In the formula (I), R ₃ represents a linear alkyl group having 12 to 50 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 (II) 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 chains derived from the compound represented by the following formula (II) into an ordered arrangement by intermolecular force or the like. R ₃ is more preferably a linear alkyl group having 14 to 30 carbon atoms, and a linear alkyl group having 18 to 30 carbon atoms is more preferred. Specific examples of such an alkyl group include dodecyl, tridecyl, tetradecyl, pentadecyl, cetyl, octadecyl, eicosyl, and icosyl. Dialkyl, behenyl, hexacosyl, octacosyl, icosyl, tetradecyl, pentadecyl and the like.

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

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

The weight average molecular weight of the thermosensitive resin of this embodiment is not specifically limited. The weight-average molecular weight of the thermosensitive resin in 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" refers to the temperature at which a particular part of the polymer integrated into an ordered arrangement becomes disordered through an equilibrium process, and is referred to as a differential scanning calorimeter (DSC), The value obtained was measured under the condition of 10 ° C / minute. The temperature-sensitive resin of the embodiment is preferably a melting point of 0 ° C or higher, more preferably 10 ° C or higher, more preferably a melting point of 120 ° C or lower, and more preferably 100 ° C or lower.

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

As shown in formula (I), the thermosensitive resin of this embodiment is a polysiloxane having a siloxane bond in the main chain. Specifically, the temperature-sensitive 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 (II) as a crystalline site and having a silicone skeleton. Siloxane. With such a structure, excellent heat resistance and chemical resistance are exhibited. That is, the conventional temperature-sensitive resin usually has an acrylic skeleton, and therefore, it has undergone severe hydrolysis under the environment of chemicals such as alkali or a high-temperature environment of 200 ° C or higher. Therefore, the conventional thermosensitive resin 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 more excellent heat resistance and chemical resistance than a conventional thermosensitive resin having an acrylic skeleton. In addition, the average degree of polymerization of the main chain siloxane in the temperature-sensitive resin of the embodiment is higher than 100 (that is, x + y + z of the formula (I) exceeds 100). Therefore, the thermosensitive resin according to this embodiment has a higher molecular weight than the conventional thermosensitive resin, and exhibits high cohesive force.

Next, an example of the manufacturing method of the thermosensitive resin of this embodiment is demonstrated. The temperature-sensitive resin of the present embodiment is obtained, for example, as follows: a chain-type polysiloxane is obtained by ring-opening polymerization of a cyclic siloxane and introduced into the chain-type polysiloxane by an addition reaction; A side chain (a side chain derived from a compound represented by the above formula (II)) formed of a linear α-olefin and a polysiloxane having a Si-H group. In the following, a specific compound is taken as an example to explain 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 (III) and (III) 'will be described as examples.

The octamethylcyclotetrasiloxane represented by formula (III) and the tetramethyltetravinylcyclotetrasiloxane represented by formula (III) 'and the following formula (IV) as a capping agent are shown. The chain siloxane may be reacted in the presence of a base catalyst represented by the following formula (V).

R ₁ in formula (IV) is as described above, and represents the same or different hydrocarbon group having 1 to 10 carbon atoms. The hydrocarbon group having 1 to 10 carbon atoms is not particularly limited, and examples thereof include alkyl groups such as methyl, ethyl, propyl, butyl, pentyl, and hexyl; alkenyl groups such as vinyl, allyl, and butenyl ; Aryl groups such as phenyl, benzyl, phenethyl, tolyl, etc .; 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 (IV) include compounds represented by the following formulae (IV) 'and (IV) ". As the compound represented by the formula (IV)', For example, "1,1,4,4-tetramethyl-1,1,4,4-tetravinyldisilazane" manufactured by Tokyo Chemical Industry Co., Ltd., "DMS-V21" manufactured by Gelest.Inc, etc. Commercially available. As compounds represented by (IV), for example, "KF-96" manufactured by Shin-Etsu Chemical Industry Co., Ltd., "hexamethyldisilazane" and "Hachi""Methyltrisiloxane" and others are commercially available.

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

The base catalyst is not limited to the compound represented by formula (V), and other base catalysts can be used. Examples of the other base catalyst include tetrabutylammonium silanolate, tetramethylphosphonium silanolate, tetrabutylphosphonium silanolate, tetramethylantimonium silanolate, and tetrabutylantimonium silanolate. , Tetrabutylphosphonium silanolate, trimethylphosphonium silanolate, triethylphosphonium silanolate, etc .; silanolates of basic organic compounds; potassium silanolate, cesium silanolate, etc. Silicone alkoxides of strongly alkaline alkali metal hydroxides, etc.

In the ring-opening polymerization, the octamethylcyclotetrasiloxane represented by formula (III) and the tetramethyltetravinylcyclotetrasiloxane represented by formula (III) 'and the The mixture of the terminal agent and the base catalyst represented by the formula (V) is preferably performed at about 0 to 120 ° C, preferably at about 70 to 120 ° C, for about 0.1 to 48 hours, and for about 0.5 to 24 hours. The reaction can be performed in a solvent such as toluene, if necessary.

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

Next, an addition reaction is demonstrated. First, a linear α-olefin and a polysiloxane having Si-H groups at both ends are reacted in the presence of a Karstedt catalyst represented by the following formula (VII). Thereafter, the obtained reactant (the compound represented by the above formula (II)) and the chain polysiloxane represented by the formula (VI) are reacted in the presence of a Karstedt catalyst represented by the formula (VII). 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. Inc. can be used. 2 "," SIP6831.2LC ", etc. are commercially available.

Examples of the linear α-olefin include a linear α-olefin having 12 to 50 carbon atoms. Among these, a linear α-olefin having 14 to 30 carbons is preferable, and a linear α-olefin having 18 to 30 carbons is more preferable. Specific examples of such a linear α-olefin include 1-octadecene represented by the following formula (VIII), and 1-docosaene represented by the formula (VIII) '. As the linear α-olefin, commercially available products such as “LINEALENE 18 (1-octadecene)” and “LINEALENE 2024 (carbon number 18 to 26)” manufactured by Idemitsu Kosan Co., Ltd. can be used. Mixtures of olefins) "and the like are commercially available.

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

The addition reaction is specifically performed by the following two-stage reaction. First, a polysiloxane having Si-H groups at both ends is added at a molar ratio of 1 to the linear α-olefin, for example, from 1 to 20, and more preferably from 4 to 10 (formula ( IX)), for example, the Karstedt catalyst is added at a ratio 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 70 ° C, for about 1 to 48 hours, and more preferably about 3 to 12 hours. The reaction can be performed in a solvent such as toluene, if necessary. Thereby, the compound represented by the said Formula (II) can be obtained by the reaction of a 1st stage.

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

The second-stage reaction can be performed by isolating the compound represented by the formula (II), or after the first-stage reaction is completed, a chain polysiloxane represented by the formula (VI) can be added to the reaction mixture. Without isolating the compound represented by formula (II).

Therefore, for example, when 1-octadecene represented by the formula (VIII) is used as the linear α-olefin and tetramethyldisilaxane represented by the formula (IX) 'is used as the siloxane, A side chain crystalline polysiloxane represented by the following formula (X) was obtained (an example of the thermosensitive resin in the embodiment). X, y, and z of the formula (X) 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 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, and the like. The solvent is not particularly limited, and examples thereof include acetone, a mixed solvent of toluene and acetone, and the like. Whether the impurities are 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 according to this embodiment contains the temperature-sensitive resin according to 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 of this embodiment type includes a temperature-sensitive resin, and the temperature-sensitive resin is crystallized at a temperature lower than the melting point to reduce 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 crystallizes and the adhesive force decreases. On the other hand, when the temperature-sensitive adhesive is heated to a temperature higher than the melting point of the temperature-sensitive resin, the temperature-sensitive resin exhibits fluidity and restores the adhesive force. As a result, the temperature-sensitive adhesive of this embodiment can be used repeatedly.

Among the temperature-sensitive adhesives of this embodiment, it is preferred that they include a polysiloxane having a Si-H group and a silanol-trimethylsilyl-modified MQ resin (hereinafter sometimes referred to simply as "MQ resin" ).

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

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 (XII), formula (XII) 'and the like, and generally has good compatibility with the above-mentioned thermosensitive resin. Commercially available MQ resins such as "SQO-299", "VQX-221" manufactured by Gelest.Inc, "Silmer VQ20", "Silmer VQ2012", "Silmer VQ122XYL", "Silmer VQ9XYL", etc. manufactured by Siltech Corpration Commercially available.

When the temperature-sensitive adhesive of this embodiment type includes 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 is preferably 10 to 1,000 parts by mass, and 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 can be directly applied to an adherend, for example, and can also be used in the form of a sheet without a substrate. The use form is not particularly limited. For example, when the temperature-sensitive adhesive of this embodiment is used as the 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, and polyfluorene. Synthetic resins such as imine, polycarbonate, 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, in order to improve 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. For example, the method of apply | coating the coating liquid obtained by adding a solvent to a thermosensitive adhesive to the one or both surfaces of a base material with a coater, etc., and drying it is mentioned. Examples of the coater include a knife coater, a roll coater, a calender coater, a comma coater, a gravure coater, and a bar coater.

In the coating liquid, a Karstedt catalyst for causing a cross-linking reaction may generally be added, and an inhibitor for suppressing the 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 crosslinking reaction based on a Karstedt catalyst proceeds. Examples of the inhibitor include 1-butyne-2-ol, 2-methyl-3-butyne-2-ol, 3,5-dimethyl-1-hexyn-3-ol, and 3- Methyl-1-penten-3-ol, phenylbutynol, 1-ethynyl-1-cyclohexanol, and the like.

The Karstedt catalyst is added to the thermosensitive resin so that the platinum concentration reaches a preferred concentration of 1 to 1000 ppm. On the other hand, the inhibitor is preferably added at a ratio of 1 to 5 parts by mass relative to 100 parts by mass of the thermosensitive resin. The composition of the coating liquid is the same when the thermosensitive adhesive is directly applied to the adherend and used, or when it is used in the form of a sheet without a substrate.

The thickness of the adhesive layer is 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 temperature-sensitive 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 base material, another adhesive layer may be laminated on the other surface. For example, an adhesive layer containing a pressure-sensitive adhesive may be laminated on another surface. The pressure-sensitive adhesive contains a polymer having adhesiveness. Examples of such an adhesive polymer include a natural rubber adhesive, a synthetic rubber adhesive, a styrene / butadiene latex-based adhesive, and an acrylic adhesive.

The release film is preferably 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 includes the temperature-sensitive resin of the above-mentioned one embodiment, a polysiloxane having a Si-H group, a silanol-trimethylsilyl-modified MQ resin, and Karstedt. catalyst. The above inhibitors can be added as needed. The details of each component are as described above, and descriptions thereof are omitted.

As described above, the temperature-sensitive resin according to an embodiment of the present invention has excellent heat resistance and chemical resistance, and has high cohesion. The use of the temperature-sensitive adhesive containing such a temperature-sensitive resin is not particularly limited, and it can be suitably used as, for example, 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 spirit 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 has been described as an example. However, the temperature-sensitive adhesive is not limited to a composition containing a polysiloxane having an Si-H group and an MQ resin under the condition that the temperature-sensitive resin is contained, and may be used in a so-called silicone-based adhesive. Consisting of conventional materials.

    [Example]    

Examples and comparative examples are given below to describe the present invention in detail, but the present invention is not limited to these examples.

(Synthesis Example 1: Synthesis of Chain Polysiloxane)

To a three-necked flask equipped with a stirring blade and a nitrogen introduction tube, 20 g of cyclic siloxane and 400 mg of a blocking agent were added. "Tetravinyltetramethylcyclotetrasiloxane (manufactured by Tokyo Chemical Industry Co., Ltd.)" was used as the cyclic siloxane, and "DMS-21 (manufactured by Gelest. Inc.)" was used as a blocking agent. Nitrogen was introduced into the mixture of the cyclic siloxane and the capping agent from a nitrogen introduction tube, and nitrogen gas was bubbled 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. 7 mg of "TETRAMETHYLAMMONIUM SILOXANOLATE (manufactured by Tokyo Chemical Industry Co., Ltd.)" as a base catalyst was added to a three-necked flask and stirred at 100 ° C for 6 hours. Next, in order to decompose the catalyst, the temperature was raised to 150 ° C., and the mixture was stirred for another 3 hours. After completion of the reaction, it was cooled to room temperature to obtain a chain-shaped polysiloxane (A) represented by the formula (VI). According to GPC measurement, the obtained chain-type polysiloxane (A) had a number average molecular weight of 55,000 and a weight average molecular weight of 137,000. The number-average molecular weight and the weight-average molecular weight can be obtained by measuring the obtained polysiloxane with a GPC, and converting the obtained measurement values into polystyrene.

(Synthesis Example 2: Synthesis of Chain Polysiloxane)

A chain-shaped polysiloxane (B) was obtained by the same procedure as in Synthesis Example 1 except that the amount of the blocking agent (DMS-21) was changed to 100 mg. According to GPC measurement, the obtained chain-type polysiloxane (B) had a number average molecular weight of 77,000 and a weight average molecular weight of 218,000.

(Synthesis Example 3: Synthesis of Chain Polysiloxane)

16 g of "tetravinyltetramethylcyclotetrasiloxane" and 4 g of "hexamethylcyclotetrasiloxane (manufactured by Tokyo Chemical Industry Co., Ltd.)" were used as the cyclic siloxane, and the blocking agent was changed to Except for 200 mg of "hexamethyldisilazane (manufactured by Tokyo Chemical Industry Co., Ltd.)", a chain polysiloxane (C) was obtained by the same procedure as in Synthesis Example 1. According to GPC measurement, the obtained chain polysiloxane (C) had a number average molecular weight of 60,000 and a weight average molecular weight of 126,000.

(Synthesis Example 4: Synthesis of a long-chain alkyl unit)

To a three-necked flask equipped with a stirring blade and a thermometer, 108.8 g of "tetramethyldisilazane (manufactured by Tokyo Chemical Industry Co., Ltd.)" and 50 g of "1-docosaene (Tokyo Chemical Industry Co., Ltd.) Made) "and 240 g of dehydrated toluene. The three-necked flask was placed in an oil bath, and the temperature was raised to 70 ° C while stirring. When it reached 70 ° C, 50 mg of a 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 Stark apparatus 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 long-chain alkyl unit represented by formula (II).

(Example 1)

<Synthesis of Side Chain Crystalline Polysiloxane (Thermal Resin)>

A three-necked flask equipped with a stirrer was charged with 3 g of the linear polysiloxane (A) obtained in Synthesis Example 1, 14.3 g of the long-chain alkyl unit obtained in Synthesis Example 4, and 40 g of dehydrated toluene. The three-necked flask was placed in an oil bath, and the temperature was raised to 100 ° C while stirring with a magnetic stirrer. When it reached 100 ° C., 60 mg of a 20% by mass toluene solution of “platinum (0) -1,3-divinyltetramethyldisilaxane complex” was added. Then, it stirred at 100 degreeC for 24 hours. Next, 100 g of a mixed solvent of toluene and acetone (mass ratio of 3: 7) was heated to 60 ° C., added to the obtained reaction mixture, and stirred. The operation of removing the solvent by decantation was repeated 3 times to obtain a precipitate. The obtained precipitate was dried under reduced pressure at 80 ° C. to obtain a side chain crystalline polysiloxane (1).

According to GPC measurement, the obtained side chain crystalline polysiloxane (1) had a number average molecular weight of 103,000 and a weight average molecular weight of 503,000. 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. Based on the integral ratio of ¹ H-NMR, the obtained side chain crystalline polysiloxane (1) contained a vinylmethylsiloxane unit in a proportion of about 3%. In addition, according to DSC measurement (10 ° C / minute), the obtained side chain crystalline polysiloxane (1) had a melting point of about 37 ° C.

<Preparation of Thermosensitive Adhesive>

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

Polysiloxane having Si-H group: "HMS-064" and "HMS-082" (both manufactured by Gelest.inc) represented by the above formula (XI) ''

MQ resin: "VQX-221" (manufactured by Gelest.inc) shown by the above formula (XII) '

<Production of Thermosensitive Adhesive Tape>

To 100 parts by mass of the obtained thermosensitive adhesive was added toluene so that the solid content concentration reached 70% by mass. The above-mentioned "platinum (0) -1,3-divinyltetramethyldisilaxane complex" is added in a proportion of 0.5 parts by mass in terms of solid content, and is 1 part by mass in terms of solid content. 2-methyl-3-butyn-2-ol was added as an inhibitor 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 fluorosilane treatment. Next, it heated at 120 degreeC for 10 minutes, and made the reactive part (vinyl group) of a side chain crystalline polysiloxane, and the reactive part (vinyl group) of MQ resin, and the functional group of the polysiloxane containing Si-H group (Si-H group) is crosslinked. Thus, a temperature-sensitive adhesive tape having an adhesive layer (thickness: 30 μm) was obtained.

(Example 2)

The same procedure as in Example 1 was used except that 3 g of the chain polysiloxane (B) obtained in Synthesis Example 2, 15 g of the long-chain alkyl unit obtained in Synthesis Example 4, and 42 g of dehydrated toluene were used. A side chain crystalline polysiloxane (2) was obtained. By 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: 124000

Weight average molecular weight: 513000

Proportion of vinyl methylsiloxane unit: about 10%

Melting point: about 39 ° C

A thermosensitive adhesive was prepared by the same procedure as in Example 1 except that a side chain crystalline polysiloxane (2) was used. A thermosensitive adhesive tape was produced by the same procedure as in Example 1 except that the thermosensitive adhesive was used.

(Example 3: Synthesis of side chain crystalline polysiloxane)

A side chain crystalline polysiloxane (3) was obtained by the same procedure as in Example 1 except that 3 g of the chain polysiloxane (C) obtained in Synthesis Example 3 was used. By 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 (3) were measured. The results are shown below.

Number average molecular weight: 102000

Weight average molecular weight: 322000

Proportion of vinyl methylsiloxane unit: about 25%

Melting point: about 31 ° C

A thermosensitive adhesive was prepared by the same procedure as in Example 1 except that a side chain crystalline polysiloxane (3) was used. A thermosensitive adhesive tape was produced by the same procedure as in Example 1 except that the thermosensitive adhesive was used.

(Comparative example 1)

A temperature-sensitive adhesive tape was prepared in the same manner as in Example 1 except that a temperature-sensitive adhesive containing a temperature-sensitive resin containing an acrylic skeleton was used instead of the temperature-sensitive adhesive obtained in Example 1. . The monomer composition, melting point, and weight average molecular weight of the temperature-sensitive resin containing an acrylic skeleton are as follows.

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

Melting point: about 55 ° C

Weight average molecular weight: 540000

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

<180 ° peeling strength>

The 180 ° peel strength with respect to polyimide in an environment of 80 ° C. and 5 ° C. was measured in accordance with JIS Z0237. Specifically, the temperature-sensitive adhesive tape was adhered to the alkali-free glass under the following conditions, and then peeled at a rate of 300 mm / min using a load sensor at 180 °.

(80 ℃)

The temperature-sensitive adhesive tape was adhered to the alkali-free glass at 80 ° C, and the polyethylene terephthalate film was peeled off. Then, a short polyimide film (thickness: 25 μm and width: 25 mm) was pasted, and it was left at 80 ° C. for 20 minutes and peeled at 180 °.

(5 ℃)

The temperature-sensitive adhesive tape was adhered to the alkali-free glass at 80 ° C, and the polyethylene terephthalate film was peeled off. Then, a short polyimide film (thickness: 25 μm and width: 25 mm) was pasted, and left to stand at 80 ° C. for 20 minutes. Next, it cooled to 5 degreeC, and after standing still for 20 minutes, it peeled at 180 degree.

<Heat resistance>

Evaluation was performed 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 / minute) in a nitrogen atmosphere, and the side chain crystalline polymerization in the process was measured. Changes in the quality of siloxane. Next, the temperature at which the mass reached 98% with respect to the mass at 25 ° C., that is, the temperature at which the mass was reduced by 2% was measured. The higher the temperature, the better the heat resistance.

<Drug resistance>

The temperature-sensitive adhesive tape was immersed in a 10% by mass sodium hydroxide aqueous solution at 23 ° C. for 10 minutes. Thereafter, the state of the thermosensitive adhesive tape was evaluated according to the following criteria.

(Evaluation criteria)

○: Swelling does not occur in the temperature-sensitive adhesive tape.

×: Swelling occurred in the thermosensitive adhesive tape.

As shown in Table 2, it can be seen that the thermosensitive adhesive tapes obtained in Examples 1 to 3 have excellent chemical resistance and excellent 180 ° peel strength. In addition, it was found that the side chain crystalline polysiloxane (thermosensitive resin) obtained in Examples 1 to 3 had a high temperature reduction of 2% by weight, and had excellent heat resistance.

Claims (8)

A thermosensitive resin represented by the following formula (I), crystallized at a temperature lower than the melting point, and exhibiting fluidity at a temperature higher than the melting point, In the 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 linear alkyl group having 12 to 50 carbon atoms; and m represents 2 to 10 Is an integer of 1 to 100; x is an integer of 0 to 2000; y is an integer of 100 to 2000; z is an integer of 1 to 1000.     The thermosensitive resin according to item 1 of the scope of patent application, wherein the melting point is 0 ° C or higher.         A temperature-sensitive adhesive containing the temperature-sensitive resin described in item 1 or 2 of the scope of patent application, and the adhesive force is reduced at a temperature lower than the melting point of the resin.         The temperature-sensitive adhesive according to item 3 of the scope of patent application, wherein the melting point is 0 ° C or higher.         The temperature-sensitive adhesive according to item 3 or 4 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 3 to 5 of the scope of patent application.         A temperature-sensitive adhesive tape obtained by laminating an adhesive layer containing the temperature-sensitive adhesive described in any one of claims 3 to 5 on at least one surface of a substrate.         A temperature-sensitive adhesive composition containing the temperature-sensitive resin described in item 1 or 2 of the patent application scope, a polysiloxane having a Si-H group, and a silanol-trimethylsilyl-modified MQ resin. And Karstedt catalysts.