TWI773675B - 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

Thermosensitive resin, thermosensitive adhesive and thermosensitive adhesive composition

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

Temperature-sensitive resins having temperature-sensitive properties that reversibly exhibit a crystalline state and a fluid state in response to temperature changes are known (for example, Patent Documents 1 and 2). Since temperature-sensitive resins are often used as adhesives, they are expected to have excellent heat resistance and chemical resistance, and high cohesion is also required.

[Prior Art Literature] [Patent Literature]

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

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

The subject of the present invention is to provide a temperature-sensitive resin having excellent heat resistance and chemical resistance and high cohesion, and a temperature-sensitive adhesive and a temperature-sensitive adhesive composition containing the temperature-sensitive resin.

The inventors of the present invention have made intensive studies in order to solve the above-mentioned problems, and as a result, they have found a solution including the following technical means, and have completed the present invention.

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

式(I)中，R₁表示相同或不同之碳數1至10的烴基。R₂表示具有烯基的基。R₃表示碳數12至50的直鏈狀烷基。m表示2至10的整數。n表示1至100的整數。x表示0至2000的整數。y表示100至2000的整數。z表示1至1000的整數。

In formula (I), R ₁ represents the same or different hydrocarbon groups having 1 to 10 carbon atoms. R ₂ represents a group having an alkenyl group. R ₃ represents a straight-chain alkyl group having 12 to 50 carbon atoms. m represents an integer of 2 to 10. n represents an integer from 1 to 100. x 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 temperature-sensitive resin according to (1) above, wherein the melting point is 0°C or higher.

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

(4) The temperature-sensitive adhesive according to (3) above, wherein the melting point is 0°C or higher.

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

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

(7) A temperature-sensitive adhesive tape obtained by laminating an adhesive layer containing the temperature-sensitive adhesive according to any one of (3) to (5) above on at least one surface of a base material.

(8) A temperature-sensitive adhesive composition comprising the temperature-sensitive resin described in (1) or (2) above, a polysiloxane having a Si-H group, a silanol-trimethylsilyl modified MQ resin, and Karstedt catalyst.

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

<Temperature Sensitive Resin>

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

In formula (I), R ₁ represents the same or different hydrocarbon groups having 1 to 10 carbon atoms. The hydrocarbon group having 1 to 10 carbon atoms is not particularly limited, and 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 the alkenyl group may have a linear structure or a branched structure.

In formula (I), R ₂ represents a group having an alkenyl group. The group having the alkenyl group is a reactive site in the temperature-sensitive resin of this 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 formula (I), R ₃ represents a linear alkyl group having 12 to 50 carbon atoms. The side chain moiety containing this R ₃ , that is, the side chain moiety derived from the compound represented by the following formula (II) is a moiety having crystallinity in the temperature-sensitive resin of the present embodiment. The temperature-sensitive resin of the present embodiment is crystallized by adjusting the orderly arrangement of the side chains derived from the compound represented by the following formula (II) by intermolecular force or the like. The preferred one for R ₃ is a straight-chain alkyl group having 14 to 30 carbon atoms, more preferably a straight-chain alkyl group having 18 to 30 carbon atoms. Specific examples of such an alkyl group include dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, octadecyl, eicosyl, eicosyl Dialkyl, tetracosyl, behenyl, octadecyl, triaconyl, tetradecyl, pentadecyl, and the like.

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

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

The weight average molecular weight of the temperature-sensitive resin of the present embodiment is not particularly limited. The weight average molecular weight of the temperature-sensitive resin of this embodiment is preferably 100,000 or more, more preferably 150,000 or more, preferably 2 million or less, and more preferably 1.5 million or less. The "weight average molecular weight" is a value obtained by measuring the 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 in association with crystallization. "Melting point" refers to the temperature at which a specific part of the polymer, which was initially adjusted into an ordered arrangement and integrated, becomes a disordered state by some equilibrium process. The obtained value was measured under the condition of 10°C/min. The temperature-sensitive resin of this embodiment preferably has a melting point of 0°C or higher, more preferably 10°C or higher, preferably 120°C or lower, and more preferably 100°C or lower.

The temperature-sensitive resin of this embodiment is crystallized at a temperature lower than the melting point, and at a temperature higher than the melting point, phase shift occurs and fluidity is exhibited. That is, the temperature-sensitive resin of the present embodiment has a temperature-sensitive property that reversibly exhibits a crystalline state and a fluid state in response to a temperature change.

The temperature-sensitive resin of this embodiment is a polysiloxane having a siloxane bond in the main chain, as represented by formula (I). Specifically, the temperature-sensitive resin of the present embodiment is a polyorganic organic silicon skeleton having R ₂ as a reactive moiety and a side chain derived from the compound represented by formula (II) as a crystalline moiety and having an organosilicon skeleton Siloxane. With such a configuration, excellent heat resistance and chemical resistance are exhibited. That is, conventional temperature-sensitive resins generally have an acrylic skeleton, and are therefore vigorously hydrolyzed in an environment of chemicals such as alkalis or in a high-temperature environment of 200° C. or higher. Therefore, the conventional temperature-sensitive resin cannot be used in the above-mentioned environment.

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

Next, an example of the manufacturing method of the temperature-sensitive resin of this embodiment is demonstrated. The temperature-sensitive resin of this embodiment is obtained, for example, by obtaining a chain polysiloxane by ring-opening polymerization of cyclosiloxane, and introducing it into the chain polysiloxane by an addition reaction. The side chain (side chain derived from the compound represented by the said formula (II)) which consists of a linear alpha-olefin and the polysiloxane which has a Si-H group. Hereinafter, one embodiment of the production method will be described by taking a specific compound as an example.

Cyclosiloxane 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 formulae (III) and (III)' will be described as examples.

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

R ₁ in the formula (IV) is as described above and represents the same or different hydrocarbon groups having 1 to 10 carbon atoms. The hydrocarbon group having 1 to 10 carbon atoms is not particularly limited, and 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 the alkenyl group may have a linear structure or a branched structure. a represents an integer of 0 to 1000, and examples of the compound represented by the formula (IV) include compounds represented by the following formulae (IV)' and (IV)". As the compound represented by the formula (IV)', For example, "DMS-V21" manufactured by Gelest. Inc. is commercially available. Examples of compounds represented by "(IV)" include "KF-96" manufactured by Shin-Etsu Chemical Co., Ltd., and "KF-96" manufactured by Tokyo Chemical Industry Co., Ltd. "Hexamethyldisiloxane" and "Octamethyltrisiloxane" are commercially available.

In the compound represented by the following formula (V) used as a base catalyst, b represents an integer of 1 to 8. 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 the formula (V), and other base catalysts can be used. Examples of other base catalysts include tetrabutylammonium siliconate, tetramethylphosphonium siliconate, tetrabutylphosphonium siliconate, tetramethylantimonium siliconate, and tetrabutylantimonium siliconate , silicon alkoxides of basic organic compounds such as tetrabutyl arsonium silicon alkoxide, trimethyl silinium alkoxide, triethyl silinium alkoxide, etc.; potassium silicon alkoxide, cesium silicon alkoxide, etc. Silicon alkoxides of strong alkaline alkali metal hydroxides, etc.

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

The mixing ratio of octamethylcyclotetrasiloxane represented by formula (III) and tetramethyltetravinylcyclotetrasiloxane represented by formula (III)' is not particularly limited. For example, the siloxane represented by the formula (III) and the siloxane represented by the formula (III)' are mixed in a molar ratio of 0:1 to 5:1, preferably 0:1 to 2:1 . The blocking agent is added in a ratio of 0.00001 to 30 parts by mass relative to 100 parts by mass of the mixture of siloxanes represented by formula (III) and formula (III)', preferably 0.00001 to 30 parts by mass. The base catalyst is added in a ratio of 0.0000001 to 1 part by mass relative to 100 parts by mass of the mixture of siloxanes represented by formula (III) and formula (III)', preferably 0.0000001 to 1 part by mass. Thereby, the chain polysiloxane represented by the following formula (VI) can be obtained. c in formula (VI) represents an integer of 0 to 2000, and d represents an integer of 101 to 3000. The chain polysiloxane represented by the formula (VI) uses the compound represented by the formula (IV)' as a capping agent.

Next, the addition reaction will be described. First, a linear α-olefin and a polysiloxane having Si—H groups at both ends are reacted in the presence of a Karstedt catalyst represented by the following formula (VII). Then, the obtained reactant (the compound represented by the above formula (II)) and the chain polysiloxane represented by the formula (VI) are reacted in the presence of the Karstedt catalyst represented by the formula (VII). Commercially available Karstedt catalysts, such as "Platinum (0)-1,3-Divinyltetramethyldisiloxane Complex" manufactured by Tokyo Chemical Industry Co., Ltd., "SIP6831. 2" and "SIP6831.2LC" are commercially available.

As the linear α-olefin, for example, a linear α-olefin having 12 to 50 carbon atoms is exemplified. Among these, linear α-olefins having 14 to 30 carbon atoms are preferable, and linear α-olefins having 18 to 30 carbon atoms are more preferable. Specific examples of such linear α-olefins include 1-octadecene represented by the following formula (VIII), 1-dodecene represented by the formula (VIII)', and the like. Commercially available linear α-olefins, for example, "LINEALENE 18 (1-octadecene)", "LINEALENE 2024 (linear α-olefin having 18 to 26 carbon atoms)" manufactured by Idemitsu Kosan Co., Ltd. Mixtures of olefins)" etc. are commercially available.

As a siloxane, the siloxane represented by following formula (IX) is mentioned, for example. R ₁ and n in the formula (IX) are as described above, and their description is omitted. As a siloxane represented by formula (IX), the tetramethyldisiloxane etc. which are represented by following formula (IX)' are mentioned specifically,.

The addition reaction is specifically carried out by the following two-stage reaction. First, a polysiloxane having Si—H groups at both ends (formula ( IX)), for example the Karstedt catalyst is added in 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 at about 50 to 70° C. for about 1 to 48 hours, and more preferably at about 3 to 12 hours. The reaction can be carried out in a solvent such as toluene if necessary. Thereby, the compound represented by the said formula (II) can be obtained in the reaction of a 1st stage.

Next, the compound represented by the obtained formula (II) and the chain polysiloxane represented by the formula (VI) are reacted in the presence of the Karstedt catalyst represented by the formula (VII). With respect to the compound represented by the formula (II), the molar ratio of 1, for example, the chain polysiloxane represented by the formula (VI) is added at a molar ratio of 0.1 to 1, preferably 0.2 to 1, such as 10 to 1. Karstedt catalyst is added at 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 can be carried out in a solvent such as toluene if necessary.

The reaction of the second stage can be carried out by isolating the compound represented by the formula (II), or it can be carried out by adding the chain polysiloxane represented by the formula (VI) to the reaction mixture after the completion of the reaction in the first stage. , without isolating the compound represented by formula (II).

Thus, for example, when 1-octadecene represented by the formula (VIII) is used as the linear α-olefin and tetramethyldisiloxane represented by the formula (IX)′ is used as the siloxane, it is possible to The side chain crystalline polysiloxane represented by the following formula (X) (an example of the temperature-sensitive resin of this embodiment) was obtained. x, y, and z of formula (X) are as described above, and their descriptions are omitted.

After the reaction, the reactant may be directly used as a temperature-sensitive resin, or the reactant may be purified and used as a temperature-sensitive resin. As a purification method, the method of removing the asymmetric olefin etc. which are an impurity by solvent washing, reprecipitation, etc. are mentioned, for example. Although it does not specifically limit as a solvent, For example, acetone, a mixed solvent of toluene and acetone, etc. are mentioned. Whether or not impurities are removed can be confirmed by, for example, GPC, ¹ H-NMR, or the like.

<Temperature-sensitive adhesive>

Next, the temperature-sensitive adhesive of one 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 of the present embodiment contains a temperature-sensitive resin that is crystallized at a temperature lower than the melting point to reduce the adhesive force. Therefore, when the temperature-sensitive adhesive is peeled off from the adherend, when the temperature-sensitive adhesive is cooled to a temperature lower than the melting point of the temperature-sensitive resin, the temperature-sensitive resin crystallizes and the adhesive force decreases. On the other hand, when the temperature-sensitive adhesive is heated to a temperature equal to or higher than the melting point of the temperature-sensitive resin, the temperature-sensitive resin exhibits fluidity and recovers the adhesive force. As a result, the temperature-sensitive adhesive of this embodiment can be used repeatedly.

Among the temperature-sensitive adhesives of the present embodiment, the preferred ones include polysiloxane with Si-H group and silanol-trimethylsilyl modified MQ resin (hereinafter sometimes abbreviated as "MQ resin"). ).

The polysiloxane having a Si—H group undergoes a cross-linking reaction with the temperature-sensitive resin to be three-dimensionalized, and can impart a 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 formulae (XI) to (XI)”, and the like. f in the formula (XI) represents an integer of 0 to 2000. The formula g in (XI)' represents an integer of 2 to 200. h in formula (XI)" represents an integer of 0 to 5000, and i represents an integer of 2 to 2000. Commercially available polysiloxanes having Si-H groups, 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), 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 (XII), formula (XII)', etc., and generally has good compatibility with the above-mentioned temperature-sensitive resin. As 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, etc. can be used Commercially available.

When the temperature-sensitive adhesive of the present embodiment contains the Si—H group-containing polysiloxane and the MQ resin, the content of each component is not particularly limited. For example, the content of the Si—H group-containing polysiloxane is preferably 0.001 to 1000 parts by mass, more preferably 0.01 to 500 parts by mass, relative to 100 parts by mass of the temperature-sensitive resin. The content of the MQ resin is preferably 10 to 1000 parts by mass, and more preferably 20 to 500 parts by mass relative to 100 parts by mass of the temperature-sensitive resin.

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

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

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

The base material may have a single-layer structure or a multilayer structure. The substrate typically has a thickness of around 5 to 500 μm. In addition, in order to improve the adhesiveness to the adhesive layer, a surface treatment such as corona discharge treatment, plasma treatment, sand blast treatment, chemical etching treatment, and primer treatment may be performed on the base material.

The method of laminating the adhesive layer on at least one surface of the base material is not particularly limited. For example, the method of apply|coating the coating liquid obtained by adding a solvent to a temperature-sensitive adhesive to one side or both sides of a base material with a coater etc., and drying, etc. are mentioned. As a coater, a knife coater, a roll coater, a calender coater, a comma coater, a gravure coater, a bar coater, etc. are mentioned, for example.

In the coating liquid, a Karstedt catalyst for generating a crosslinking reaction may be usually 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 the crosslinking reaction in the adhesive layer can be suppressed. When the inhibitor is volatilized by heating above the boiling point of the inhibitor, a crosslinking reaction by 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, 3- Methyl-1-penten-3-ol, phenylbutynol, 1-ethynyl-1-cyclohexanol, etc.

The Karstedt catalyst is added to the temperature-sensitive resin such that the platinum concentration is preferably 1 to 1000 ppm. On the other hand, the inhibitor is preferably added in a ratio of 1 to 5 parts by mass with respect to 100 parts by mass of the temperature-sensitive resin. The composition of the coating liquid is the same when the temperature-sensitive adhesive is directly applied to the adherend and used, or when it is used in the form of a sheet without a substrate.

The thickness of the adhesive layer is preferably 1 to 100 μm, more preferably 5 to 80 μm, and still more preferably 10 to 60 μm. When the adhesive layers are laminated on both sides of the substrate, the thicknesses of the adhesive layers may be the same or different, and the composition of the temperature-sensitive adhesive forming the adhesive layers may be the same or different.

Moreover, as long as the adhesive containing the temperature-sensitive adhesive of this embodiment is laminated|stacked on 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 contains an adhesive polymer. Examples of such adhesive polymers include natural rubber adhesives, synthetic rubber adhesives, styrene/butadiene latex-based adhesives, acrylic adhesives, and the like.

It is preferable to laminate a release film on the surface of the temperature-sensitive adhesive sheet and the temperature-sensitive adhesive tape of the present embodiment. As a mold release film, the polyethylene terephthalate film etc. which apply|coat the mold release agent like fluorosiloxane on the surface, etc. are mentioned, for example.

<The temperature-sensitive adhesive composition>

Next, the temperature-sensitive adhesive composition of one 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, polysiloxane having Si-H group, silanol-trimethylsilyl modified MQ resin, and Karstedt catalyst. The above-mentioned inhibitors may be added as needed. The details of each component are as described above, and the description is omitted.

As described above, the temperature-sensitive resin of one 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 for example, it can be suitably used as an adhesive in the fields where heat resistance and chemical resistance are required.

The present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the gist of the present invention. For example, in the above-mentioned one embodiment, the temperature-sensitive adhesive containing a temperature-sensitive resin, a polysiloxane having a Si—H group, and an MQ resin was described as an example. However, under the condition that the temperature-sensitive adhesive contains the above-mentioned temperature-sensitive resin, it is not limited to the composition including polysiloxane and MQ resin having Si—H group, and can be made of so-called silicone-based adhesives. Constructed of conventional materials.

[Example]

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

(Synthesis Example 1: Synthesis of Chain Polysiloxane)

20 g of cyclosiloxane and 400 mg of end-capping agent were added to a three-necked flask equipped with a stirring blade and a nitrogen introduction tube. "Tetravinyltetramethylcyclotetrasiloxane (manufactured by Tokyo Chemical Industry Co., Ltd.)" was used as the cyclosiloxane, and "DMS-21 (manufactured by Gelest. Inc.)" was used as a blocking agent. Nitrogen gas was introduced into the mixture of the cyclosiloxane and the blocking agent from a nitrogen gas introduction pipe, and nitrogen gas 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. 7 mg of "TETRAMETHYLAMMONIUM SILOXANOLATE (manufactured by Tokyo Chemical Industry Co., Ltd.)" as a base catalyst was added to the three-necked flask, and the mixture was 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 further stirred for 3 hours. After completion of the reaction, it was cooled to room temperature to obtain the chain polysiloxane (A) represented by the formula (VI). The obtained chain polysiloxane (A) had a number average molecular weight of 55,000 and a weight average molecular weight of 137,000 as measured by GPC. The number average molecular weight and the weight average molecular weight can be obtained by measuring the obtained chain polysiloxane by GPC, and converting the obtained measured value into polystyrene.

(Synthesis Example 2: Synthesis of Chain Polysiloxane)

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

(Synthesis Example 3: Synthesis of Chain Polysiloxane)

16g of "tetravinyltetramethylcyclotetrasiloxane" and 4g of "hexamethylcyclotetrasiloxane (manufactured by Tokyo Chemical Industry Co., Ltd.)" were used as cyclosiloxanes, and the capping agent system was changed to A chain polysiloxane (C) was obtained by the same procedure as in Synthesis Example 1, except for 200 mg of "hexamethyldisiloxane (manufactured by Tokyo Chemical Industry Co., Ltd.)". The obtained chain polysiloxane (C) had a number average molecular weight of 60,000 and a weight average molecular weight of 126,000 according to GPC measurement.

(Synthesis Example 4: Synthesis of Long Chain Alkyl Unit)

108.8 g of "tetramethyldisiloxane (manufactured by Tokyo Chemical Industry Co., Ltd.)" and 50 g of "1-docosene (Tokyo Chemical Industry Co., Ltd.)" were added to a three-necked flask equipped with a stirring blade and a thermometer. system)” 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 degreeC, the 20 mass % toluene solution of 50 mg of "platinum (0)-1,3-divinyltetramethyldisiloxane complex (made 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 the unreacted tetramethyldisiloxane was recovered by heating at 100° C. for 3 hours. Next, the reaction mixture in the three-necked flask was dropped into ethanol to carry out precipitation purification. The precipitate was collected 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 (temperature-sensitive resin)>

3 g of the chain polysiloxane (A) obtained in Synthesis Example 1, 14.3 g of the long-chain alkyl units obtained in Synthesis Example 4, and 40 g of dehydrated toluene were added to a three-necked flask equipped with a stirring bar. 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 degreeC, the 20 mass % toluene solution of 60 mg of "platinum (0)-1,3-divinyltetramethyldisiloxane complex" was added. Then, it stirred at 100 degreeC for 24 hours. Next, 100 g of a mixed solvent (mass ratio of 3:7) of toluene and acetone was heated to 60° C., added to the obtained reaction mixture, and stirred. The operation of removing the solvent by decantation was repeated three times to obtain a precipitate. The obtained precipitate was dried under reduced pressure at 80°C to obtain 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 by GPC, and converting the obtained measured value into polystyrene. According to the integral ratio of ¹ H-NMR, vinylmethylsiloxane units were contained in the obtained side chain crystalline polysiloxane (1) in a ratio of about 3%. Further, the obtained side chain crystalline polysiloxane (1) had a melting point of about 37°C according to DSC measurement (10°C/min).

<Preparation of temperature-sensitive adhesive>

The obtained side-chain crystalline polysiloxane (1), the MQ resin, and the polysiloxane having a Si—H group were mixed at the ratio shown in Table 1 to prepare a temperature-sensitive adhesive. The polysiloxanes and MQ resins having Si-H groups used are shown below.

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

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

<Production of temperature-sensitive adhesive tape>

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. However, the above-mentioned "platinum (0)-1,3-divinyltetramethyldisiloxane complex" was added in a ratio of 0.5 part by mass in terms of solid content, and the ratio was 1 part by mass in terms of solid content A coating liquid was prepared by adding 2-methyl-3-butyn-2-ol as an inhibitor in a proportion of The obtained coating liquid was apply|coated to the single side|surface of a polyethylene terephthalate film (thickness 75 micrometers), ie, the surface which performed the fluorosiloxane process. Next, heating at 120° C. for 10 minutes causes the reactive moieties (vinyl groups) of the side-chain crystalline polysiloxane and the reactive moieties (vinyl groups) of the MQ resin to react with the functional groups of the polysiloxane having Si—H groups (Si-H group) for crosslinking. Thereby, the temperature-sensitive adhesive tape in which the adhesive layer (thickness 30 micrometers) was formed was obtained.

(Example 2)

The same procedure as in Example 1 was performed 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. The side chain crystalline polysiloxane (2) was obtained. By the same procedure as in Example 1, the number average molecular weight, weight average molecular weight, ratio of vinylmethylsiloxane units, and 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

Ratio of vinylmethylsiloxane units: about 10%

Melting point: about 39℃

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

(Example 3: Synthesis of side chain crystalline polysiloxane)

A side-chain crystalline polysiloxane (3) was obtained by the same procedure as in Example 1, except that 3 g of the chain-like polysiloxane (C) obtained in Synthesis Example 3 was used. By the same procedure as Example 1, the number average molecular weight, weight average molecular weight, ratio of vinylmethylsiloxane units, and 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

Ratio of vinylmethylsiloxane units: about 25%

Melting point: about 31℃

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

(Comparative Example 1)

A temperature-sensitive adhesive tape was produced by the same procedure as in Example 1, except that a temperature-sensitive adhesive containing an acrylic skeleton-containing temperature-sensitive resin 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℃

Weight average molecular weight: 540000

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

<180° peel strength>

The 180° peel strength with respect to polyimide in an environment of 80°C and 5°C was measured according to JIS Z0237. Specifically, after adhering the temperature-sensitive adhesive tape to the alkali-free glass under the following conditions, 180° peeling was performed at a speed of 300 mm/min using a load cell.

(80℃)

The temperature-sensitive adhesive tape was attached to the alkali-free glass in an environment of 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 it was left to stand at 80° C. for 20 minutes to perform 180° peeling.

(5℃)

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

<heat resistance>

Evaluation was performed by thermogravimetric analysis (TGA). Specifically, using a thermogravimetric analyzer "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 polymer in the process was measured. Mass change of siloxane. Next, the temperature at which the mass reaches 98% of the mass at 25° C., that is, the temperature at which the mass decreases by 2%, is measured. The higher the temperature, the better the heat resistance.

<Resistance>

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

(Evaluation Criteria)

○: The temperature-sensitive adhesive tape is not swollen.

×: The temperature-sensitive adhesive tape is swollen.

As shown in Table 2, it was found that the temperature-sensitive adhesive tapes obtained in Examples 1 to 3 had excellent chemical resistance and were also excellent in 180° peel strength. In addition, it was found that the side-chain crystalline polysiloxanes (temperature-sensitive resins) obtained in Examples 1 to 3 had a high temperature at which 2% by weight was reduced, and had excellent heat resistance.

Claims (8)

A temperature-sensitive 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 groups having 1 to 10 carbon atoms; R ₂ represents a group having an alkenyl group; R ₃ represents a straight-chain alkyl group having 12 to 50 carbon atoms; m represents 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. The temperature-sensitive resin according to claim 1, wherein the melting point is 0°C or higher. A temperature-sensitive adhesive, which contains the temperature-sensitive resin described in claim 1 or 2, and which reduces the adhesive force at a temperature lower than the melting point of the resin. The temperature-sensitive adhesive according to claim 3, wherein the melting point is 0°C or higher. The temperature-sensitive adhesive according to claim 3 or 4 of the claimed scope further comprises polysiloxane with Si-H group and silanol-trimethylsilyl modified MQ resin. A temperature-sensitive adhesive sheet comprising the temperature-sensitive adhesive according to any one of claims 3 to 5 of the patent application scope. A temperature-sensitive adhesive tape obtained by laminating an adhesive layer comprising the temperature-sensitive adhesive described in any one of the claims 3 to 5 on at least one surface of a base material. A temperature-sensitive adhesive composition, which contains the temperature-sensitive resin described in item 1 or 2 of the patent application scope, polysiloxane with Si-H group, and silanol-trimethylsilyl modified MQ resin , and the Karstedt catalyst.