TW201842107A - Heat-melt adhesive tape and method for manufacturing the same capable of enhancing the curing of an adhesion layer during heating - Google Patents

Abstract

An object of the present invention is to provide a substrate-free heat-melt adhesive tape or the like, which enhances the curing of an adhesion layer during heating and hardly cures the adhesion layer when not being heated such as during storage. To solve the problem, there is no substrate provided in the heat-melt adhesive tape (1), and the heat-melt adhesive tape (1) is bonded to an object by heat-bonding, and is provided with an adhesion layer (3) containing an acrylonitrile-butadiene rubber, a phenol resin, a peroxide capable of producing acid by hydrolysis, and a phenol resin crosslinking agent. In addition, when the half-life temperature of the peroxide is 130 DEG C or more and 170 DEG C or less and the acrylonitrile-butadiene rubber is taken as 100 parts by mass, the adhesion layer (3) contains 0.5 parts by mass or more and 5 parts by mass or less of the peroxide.

Description

Thermal adhesive tape and manufacturing method of thermal adhesive tape

The present invention relates to heat-adhesive tapes and the like. In more detail, in a use form, that is, a form in which an adherend is bonded, a base material is not provided, and a heat-adhesive tape or the like attached to a glass cloth is used.

Conventionally, it has been known that the adhesive layer is hardened by heat and pressure bonding, and a thermal adhesive tape that joins an adherend is known. This heat-adhesive tape is used, for example, for the purpose of joining an adherend, such as a glass cloth, and joining an adherend by heat and pressure bonding to one side and the other side of an adhesive layer.

Patent Document 1 discloses that an adhesive tape for a semiconductor device contains an acrylonitrile-butadiene copolymer, a novolac-type phenol resin, and an epoxy resin in an adhesive layer, and contains NBR for self-crosslinking during heating of NBR. Alkyl peroxides and the like. Patent Document 2 discloses a curable resin composition comprising an organic peroxide such as vinyl benzyl etherified novolac resin, novolac type or soluble phenol resin, dicumyl peroxide, and hexamethylene. Composed of tetramine. Patent Document 3 discloses a sealant for a liquid crystal display unit, which includes an organic peroxide such as a partially esterified epoxy (meth) acrylate resin, an octyl peroxide, a phenol resin, and an organic silicon compound. [Prior Art Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open No. 5-291360 [Patent Document 2] Japanese Patent Laid-Open No. 6-329875 [Patent Document 3] Japanese Patent Laid-Open No. 9-194567

[Problems to be Solved by the Invention]

In order to achieve the adhesion of the heat-adhesive tape to the adherend in a short time, an acid is contained in the adhesive layer, and the heat and pressure of the heat-adhesive tape is used to promote the adhesion of the phenol resin and the phenol resin contained in the adhesive layer. The reaction of the cross-linking agent (hardener) will promote the hardening of the adhesive layer. However, if an acid is contained in the adhesive layer, the reaction between the phenol resin and the cross-linking agent is gradually promoted by the acid even when the thermal adhesive tape is not heated, such as during storage of the thermal adhesive tape, and the curing of the adhesive layer proceeds. Situation. Before the heat-bonding of the heat-adhesive tape and the curing of the adhesive layer has proceeded, even if the adherend is heat-pressed to the heat-adhesive tape, there is a possibility that the adhesion of the heat-adhesive tape to the adherence may not be sufficiently obtained.之 An object of the present invention is to provide a substrate-free thermal adhesive tape or the like, which promotes curing of the adhesive layer during heating, and does not easily cure the adhesive layer during non-heating such as storage. [Means for solving problems]

The heat-adhesive tape of the present invention is a so-called non-base-material heat-adhesive tape which is not provided with a base material and is bonded to an adherend by heating and pressure bonding. Decomposition of acid peroxide and adhesive layer of phenol resin crosslinker.

Here, it is preferable that the heat-adhesive tape further includes a release liner which is provided on at least one side of the adhesive layer and can be peeled from the adhesive layer.

The peroxide-based half-life temperature is preferably 130 ° C or higher and 170 ° C or lower.

When the acrylonitrile-butadiene rubber is used as 100 parts by mass of the subsequent layer system, it may contain 0.5 to 5 parts by mass of a peroxide.

In addition, the method for producing a substrate-free heat-adhesive tape of the present invention that does not include a substrate and joins an adherend by heating and pressure bonding is characterized by including: a release liner preparation step for preparing a release liner; and, it will include acrylic A solution for the adhesive layer of a nitrile-butadiene rubber, a phenol resin, a peroxide generated by decomposition and a phenol resin cross-linking agent is applied to a release liner to form an adhesive layer forming step. [Effect of the invention]

According to the present invention, a substrate-free thermal adhesive tape or the like can be provided, which promotes the curing of the adhesive layer when heated. Adhesive layer is not easily hardened when not heated during storage, etc.

[Mode for Carrying Out the Invention]

Hereinafter, embodiments of the present invention will be described in detail. The present invention is not limited to the following embodiments. In addition, various modifications can be implemented within the scope of the gist. It should be noted that the drawings used are for explaining this embodiment, and do not show actual sizes.

<Explanation of the overall structure of a heat-adhesive tape> FIG. 1 is a cross-sectional view showing a heat-adhesive tape 1 according to this embodiment. The heat-adhesive tape 1 shown in the figure includes an adhesive layer 3 and a release liner 2 provided on one side of the adhesive layer 3. After the heat-adhesive tape 1 is attached to the adherend, the release liner 2 can be peeled off. Although not shown, in FIG. 1, another release liner or the like may be provided on the surface side of the adhesive layer 3 opposite to the release liner 2.

The heat-adhesive tape 1 is bonded to an adherend by thermal compression bonding. Specifically, for example, when the adherend is a glass cloth, in the manufacturing step of manufacturing the glass cloth, it is used for joining the ends of a roll-shaped raw material in which a long glass cloth is wound, and the like. At this time, between the ends of the roll-shaped raw material, the adhesive layer 3 of the peeled release liner 2 was sandwiched, and then this place was pressed while heating. Thereby, the adhesive layer 3 is hardened, and the ends of the roll-shaped raw material are joined to each other with the adhesive tape 1 interposed therebetween. That is, the thermal adhesive tape 1 of this embodiment cannot be bonded to an adherend unless it is heated and pressure-bonded, and is different from an adhesive tape that adheres to an adherend by an adhesive force.

<Release Liner> Release Liner 2 is used in the production of the heat-adhesive tape 1, and it is required to suppress adhesion of dust and the like to the adhesive layer 3 and maintain the adhesiveness of the adhesive layer 3. There are no particular restrictions on the user who can use it as a release liner. Examples include synthetic resins such as polyethylene, polypropylene, and polyethylene terephthalate, paper, etc. on the surface of the release liner in order to improve the adhesion layer. The peelability of 3 may be a peeling treatment by a silicone-based peeling treatment agent, a long-chain alkyl-based peeling treatment agent, a fluorine-based peeling treatment agent, or the like. The thickness of the release liner is not particularly limited, and a thickness of 10 μm to 200 μm can be suitably used.

<Adhesive layer> The adhesive layer 3 is a functional layer that is hardened by heating and exerts an adhesive force between the thermal adhesive tape 1 and the adherend at the time when it is pressed. (2) The thickness of the heat-adhesive tape 1 of this embodiment is preferably 25 μm or more and 200 μm or less. If the thickness of the adhesive layer 3 is less than 25 μm, it is difficult to maintain the strength against the shear force. Here, the so-called shearing force is a force in a direction of thermally bonding the surface of the tape. In addition, if the thickness of the adhesive layer 3 exceeds 200 μm, when the thermal adhesive tape 1 is wound into a roll-shaped product, the diameter of the roll becomes too large, or wrinkles are easily introduced. In addition, in the manufacturing step of the heat-adhesive tape 1, the solvent tends to remain, or unevenness is easily formed on the surface of the adhesive layer 3, and the appearance is liable to deteriorate.

In the present embodiment, the adhesive layer 3 includes an acrylonitrile-butadiene rubber, a phenol resin, a peroxide, and a phenol resin crosslinking agent.

The structure of the acrylonitrile-butadiene rubber is not particularly limited. For example, either a linear acrylonitrile-butadiene rubber or an acrylonitrile-butadiene rubber having a branched structure can be used. However, in this embodiment, it is more preferable to use an acrylonitrile-butadiene rubber having a branched structure.的 Acrylonitrile-butadiene rubber having a branched structure can impart moderate softness to the adhesive layer 3, and at the same time can provide extremely high cohesion. The acrylonitrile-butadiene rubber having a branched structure used in this embodiment is among acrylonitrile-butadiene rubbers, and is classified as a hot rubber produced at a polymerization temperature of 25 ° C to 50 ° C. For example, the following Said formula 1 expression.

The general formula (1) of the following formula 2 is a structural formula of a linear acrylonitrile-butadiene rubber. Here, m and n are integers of 1 or more. The acrylonitrile-butadiene rubber having a branched structure represented by the formula (1) is a double bond of butadiene in the general formula (1) is cleaved, and further a compound represented by the general formula (1) is bonded there. structure. That is, each line system shown by a curve in Formula 1 has a structure represented by General formula (1). In this embodiment, as the acrylonitrile-butadiene rubber having a branched structure, for example, a weight average molecular weight (Mw) of 300,000 can be used.

A phenol resin system provides thermosetting, heat resistance, and adhesiveness to the adhesive layer 3. The phenol resin used in this embodiment is not particularly limited, and a novolak resin that synthesizes phenols and formaldehyde under an acid catalyst can be suitably used. Examples of the phenols include phenol, cresol, xylenol, alkylphenol, halogenated phenol, arylphenol, aminophenol, nitrophenol, bisphenol A, polyphenol, and derivatives thereof. . In addition, these can be used individually or in mixture of 2 or more types.

The peroxide is thermally decomposed when the adhesive tape 1 is heated, and the acrylonitrile-butadiene rubber is crosslinked by the generated free radicals. Here, in this embodiment, a peroxide that generates an acid due to decomposition can be suitably used. That is, if this peroxide is contained in the adhesive layer 3, when the adhesive tape 1 is heated and heated, the curing speed of the adhesive layer 3 increases. Specifically, when the heat-adhesive tape 1 of this embodiment is heated, as described above, the peroxide is first thermally decomposed, and the acrylonitrile-butadiene rubber is crosslinked by the generated free radicals. At this time, the free radical system reacts with hydrogen drawn from the acrylonitrile-butadiene rubber to generate an acid. Then, by this acid, the reaction between the phenol resin and the phenol resin cross-linking agent is promoted, crosslinking of the phenol resin occurs, the hardening of the phenol resin is promoted, and then the hardening speed of the layer 3 is increased.

On the other hand, the peroxide contained in the adhesive layer 3 of the present embodiment is hard to decompose when the adhesive tape 1 is heated without heating under room temperature environment, and it is difficult to generate acid. The peroxide itself does not directly affect the reaction of the phenol resin. Therefore, when the adhesive tape 1 is bonded without heating, the phenol resin is hardly hardened.

The peroxide-based half-life temperature is preferably 130 ° C or higher and 170 ° C or lower. Here, the so-called half-life temperature is the temperature at which the peroxide concentration is reduced by half from the concentration immediately before heating due to peroxide decomposition when the peroxide is heated for 1 minute.

When the half-life temperature of the peroxide is higher than 170 ° C, when the peroxide is heated, the peroxide decomposes slowly and it is difficult to generate acid. In this case, it is difficult to promote hardening of the phenol resin when the thermal adhesive tape 1 is heated. When the half-life temperature of gadolinium peroxide is lower than 130 ° C, even when the peroxide is not heated, the peroxide is decomposed and an acid is easily generated. In this case, even when the heat-adhesive tape 1 is not heated during storage of the heat-adhesive tape 1 or the like, the curing of the phenol resin is easy.

When the acrylonitrile-butadiene rubber is taken as 100 parts by mass, the adhesive layer 3 preferably contains 0.5 to 5 parts by mass of a peroxide. If the peroxide is less than 0.5 parts by mass, the amount of acid generated by the peroxide is small, and it is difficult to promote hardening of the phenol resin when the heat-adhesive tape 1 is heated. In addition, when the peroxide exceeds 5 parts by mass, when the peroxide is not heated, the peroxide is slowly decomposed, and the amount of acid generated is increased. In this case, even when the heat-adhesive tape 1 is not heated during storage of the heat-adhesive tape 1 or the like, the curing of the phenol resin is easy.

As the peroxide that generates an acid due to decomposition, a difluorenyl peroxide or a peroxyester can be suitably used. Moreover, in this embodiment, these can be used individually or in mixture of 2 or more types. Examples of the difluorenyl peroxide include Nyper (registered trademark) BMT or Peroyl (registered trademark) L manufactured by Nippon Oil Co., Ltd. Examples of the peroxyester include Perbutyl (registered trademark) O or Perbutyl Z manufactured by Nippon Oil Corporation.

The phenol resin cross-linking agent undergoes an addition condensation reaction with the phenol resin when the adhesive tape 1 is heated and heated, so that the phenol resin hardens in a shorter time. The phenol resin cross-linking agent is also called a phenol resin cross-linking accelerator and a hardener. Examples of the phenol resin crosslinking agent include hexamine tetramethylamine (hexamine), methylolmelamine, and methylolurea. These can be used individually or in mixture of 2 or more types. In this embodiment, hexamine can be suitably used among them.

The adhesive layer 3 is within the scope of the gist of this embodiment, and may further include other resins, rubbers, and the like. In addition, when applying the solution for an adhesive layer of a coating liquid described later, in order to improve the coatability, a thickener or an antifoaming agent for suppressing foaming and cracking of appearance may be further included.

<The manufacturing method of a heat-adhesive tape> FIG. 2 is a flowchart explaining the manufacturing method of a heat-adhesive tape 1. First, prepare the release liner 2 (step 101: release liner preparation step).

Next, a solution for an adhesive layer for applying the adhesive layer 3 is prepared (step 102: a solution for an adhesive layer production step). This solution for the adhesive layer contains the acrylonitrile-butadiene rubber, phenol resin, peroxide, and phenol resin cross-linking agent described above, and after adding these to a predetermined solvent, stirring is performed. A commercially available product may be used as the solution for the adhesive layer.

Then, a solution for an adhesive layer is applied on the release liner 2 to form a coating film (step 103). Furthermore, this coating film is dried, and the adhesive layer 3 is formed on the release liner 2 (step: 104). The steps of step 103 and step 104 are to apply a solution for an adhesive layer on the release liner 2 and can be regarded as an adhesive layer forming step of forming the adhesive layer 3.

By the above steps, the thickness of the adhesive layer 3 is 25 μm or more and 200 μm or less, and the thermal adhesive tape 1 of this embodiment can be manufactured. According to the aspect detailed above, a baseless heat-adhesive tape 1 without a base material can be provided.

In addition, when the adherend is heated and pressure-bonded to the heat-adhesive tape 1, the peroxide system contained in the adhesive layer 3 is decomposed to generate an acid, and this acid system promotes the hardening of the phenol resin and the phenol resin crosslinking agent. Therefore, the curing speed of the adhesive layer 3 is increased, and the thermal adhesive tape 1 is adhered to the adherend in a short time. On the other hand, when the adhesive tape 1 is adhered without heating, the decomposition of the peroxide is unlikely to occur, and it is difficult to generate an acid, and the curing of the adhesive layer 3 is not easily performed. Therefore, during storage without using the heat-adhesive tape 1, the heat-adhesive tape 1 does not easily lose the adhesive force. [Example]

Hereinafter, the present invention will be described in more detail using examples. The present invention is not limited to these examples as long as the gist is not exceeded.

The heat-adhesive tape 1 shown in FIG. 1 was produced and evaluated. The conditions and evaluation results are shown in Table 1 below. [Production of Thermal Adhesive Tape 1] (Example 1) In this example, as the release liner 2, a thickness of 120 μm was used. Then, on one surface side of the release liner 2, an adhesive layer 3 was formed as follows. First, ethyl acetate is used as a solvent, and acrylonitrile-butadiene rubber having a branched structure, a phenol resin, a peroxide, and a phenol resin cross-linking agent are added to the solvent, and they are stirred and dissolved to prepare a solid content concentration. 40% by mass of a solution for an adhesive layer. At this time, as the acrylonitrile-butadiene rubber having a branched structure, Nipol (registered trademark) 1001LG manufactured by Japan Zeon Corporation was used. As the phenol resin, Tamanol (registered trademark) 531 manufactured by Arakawa Chemical Industries, Ltd. was used. In addition, Tamanol 531 contains 9% by mass of hexamine as a phenol resin crosslinking agent. In addition, the mass ratio of the acrylonitrile-butadiene rubber having a branched structure to the phenol resin was 100/120. As the peroxide, Nyper BMT manufactured by Nippon Oil Co., Ltd. was used.

The general formula (2) of the following formula 3 is a structural formula of Nyper BMT. In addition, the general formula (3) of the following formula 4 is a reaction formula when Nyper BMT is heated and decomposed, and is a reaction formula when benzamidine peroxide having a part of the structure of Nyper BMT is decomposed. When benzophenazine peroxide in the general formula (3) is heated, the oxygen-oxygen bond system is cleaved, and 2 equivalents of phenyl radicals are generated relative to benzophenazine peroxide, and each phenyl radical system becomes benzoic acid . That is, if benzophenazine peroxide is thermally decomposed, 2 equivalents of acid will be generated with respect to this benzophenazine peroxide. In addition, if the benzamyl m-toluenyl peroxide structure of another part of Nyper BMT in the general formula (2) is thermally decomposed, the benzamyl m-toluenyl peroxide Radical peroxide, yielding 2 equivalents of acid. In addition, if the toluenyl peroxide of another structure of Nyper BMT in the general formula (2) is thermally decomposed, 2 equivalents of acid are generated relative to the toluenyl peroxide. That is, when Nyper BMT is thermally decomposed, 2 equivalents of acid are generated relative to this Nyper BMT. In addition, the half-life temperature of Nyper BMT is 131 ° C. When acrylonitrile-butadiene rubber is taken as 100 parts by mass, the adhesive layer 3 contains 3 parts by mass of Nyper BMT.

Then, the adhesive layer solution was applied on the release liner 2 and dried to form an adhesive layer 3. The thickness of the adhesive layer 3 was set to 50 mm. Through the above steps, the heat-adhesive tape 1 of this embodiment is produced.

(Examples 2 to 8) 热 A heat-adhesive tape 1 was produced in the same manner as in Example 1 except that Example 1 was changed as shown in Table 1. That is, in Examples 2, 3, and 6, the type of the peroxide contained in the bonding layer 3 was changed. Specifically, in Example 2, Perbutyl O manufactured by Nippon Oil Co., Ltd. was used. The general formula (4) of the following formula 5 is a structural formula of 2-ethylhexyltributyltributyl peroxide which is Perbutyl O. When the 2-ethylhexyltributyltributyl peroxide in the general formula (4) is heated, the oxygen-oxygen bond system is cleaved. One equivalent of free radicals is generated, and this free radical system becomes a carboxylic acid. That is, when Perbutyl O is thermally decomposed, 1 equivalent of acid is generated with respect to this Perbutyl O. The half-life temperature of Perbutyl O was 134 ° C. When acrylonitrile-butadiene rubber is taken as 100 parts by mass, the adhesive layer 3 contains 3 parts by mass of Perbutyl O.

In Example 3, Perbutyl Z manufactured by Nippon Oil Co., Ltd. was used. The general formula (5) of the following formula 6 is a structural formula of a third butylbenzylhydrazine peroxide as Perbutyl Z. When the third butylbenzylfluorenyl peroxide in the general formula (5) is heated, the oxygen-oxygen bond system is cleaved, and 1 equivalent of a radical is generated relative to the third butylbenzylfluorenyl peroxide. This free radical becomes a carboxylic acid. That is, when Perbutyl Z is thermally decomposed, 1 equivalent of acid is generated with respect to this Perbutyl Z. The half-life temperature of Perbutyl Z is 167 ° C. When acrylonitrile-butadiene rubber is taken as 100 parts by mass, the adhesive layer 3 contains 3 parts by mass of Perbutyl Z.

In Example 6, Peroyl L manufactured by Nippon Oil Co., Ltd. was used. The general formula (6) of the following formula 7 is a structural formula of a dodecylfluorene peroxide of Peroyl L. When the dodecylfluorenyl peroxide in the general formula (6) is heated, the oxygen-oxygen bond system is cleaved, and 2 equivalents of free radicals are generated relative to the dodecylfluorenyl peroxide, and each radical system becomes carboxylic acid. That is, when Peroyl L is thermally decomposed, 2 equivalents of acid are generated with respect to this Peroyl L. The half-life temperature of Peroyl L was 116 ° C. When the acrylonitrile-butadiene rubber is taken as 100 parts by mass, the adhesive layer 3 contains 3 parts by mass of Peroyl L.

Moreover, in Examples 4 and 5, the amount of the peroxide contained in the adhesion layer 3 was changed. Specifically, in Example 4, when acrylonitrile-butadiene rubber was taken as 100 parts by mass, 0.4 parts by mass of Nyper BMT was included. In addition, in Example 5, when acrylonitrile-butadiene rubber was taken as 100 parts by mass, 6 parts by mass of Nyper BMT was included.

In Examples 7 and 8, the thickness of the adhesive layer 3 was changed. Specifically, in Example 7, the thickness of the adhesive layer 3 was set to 25 μm. In Example 8, the thickness of the adhesive layer 3 was set to 200 μm.

(Comparative Examples 1 to 3) 热 A heat-adhesive tape 1 was produced in the same manner as in Example 1 except that Example 1 was changed as shown in Table 1. That is, in Comparative Example 1, no peroxide was contained in the adhesive layer 3. In addition, in Comparative Example 2, benzoic acid as a substitute for peroxide is contained in the adhesive layer 3. Specifically, when 100 parts by mass of acrylonitrile-butadiene rubber is used, 3 parts by mass of benzoic acid is included. In Comparative Example 3, as a peroxide, Perhexyl (registered trademark) I manufactured by Nippon Oil Co., Ltd. was used. The general formula (7) of the following formula 8 is a structural formula of the third hexylperoxyisopropyl monocarbonate as Perhexyl I. When the third hexylperoxyisopropyl monocarbonate in the general formula (7) is heated, radicals and carbon dioxide are generated, but no acid is generated. The half-life temperature of Perhexyl I was 155 ° C. When the acrylonitrile-butadiene rubber is taken as 100 parts by mass, the adhesive layer 3 contains 3 parts by mass of Perhexyl I.

As the evaluations of Examples 1 to 8 and Comparative Examples 1 to 3, the evaluation of the adhesive strength of the thermal adhesive tape before storage (evaluation of the adhesive strength before storage) and the evaluation of the insoluble content of the thermal adhesive tape before storage (before storage) Evaluation of insoluble content). Further, the evaluation of the adhesive strength of the thermal adhesive tape after storage (evaluation of the adhesive strength after storage) and the evaluation of the insoluble content of the thermal adhesive tape after storage (evaluation of the insoluble content after storage) were performed.

[Method for evaluating adhesive force before storage] As an evaluation of the adhesive force of the thermal adhesive tapes of Examples 1 to 8 and Comparative Examples 1 to 3, a shearing force was applied to the thermal adhesive tape, and the adhesive force was evaluated. Specifically, two glass cloths were prepared, and the two glass cloths were sandwiched with the heat-adhesive tape, and the two glass cloths were bonded with the heat-adhesive tape by heating and pressure bonding. The thickness of the glass cloth used in the evaluation was 0.17 mm, and the breaking strength was about 300 N / 10 mm. In addition, it is prepared to join glass cloths by heat-adhesive tape under two kinds of conditions of thermocompression bonding. Specifically, it is prepared to press for 20 seconds at a temperature of 160 ° C and a pressure of 1.47 × 10 ⁵ N / m ² , while bonding the glass cloth with a heat-adhesive tape, and a temperature of 170 ° C and 1.47 × 10 ⁵ N / m ² . The pressure was applied for 10 seconds, and the glass cloth was joined by heat-adhesive tape.

Then, the produced two glass cloths as an adherend were stretched at a stretching speed of 200 mm / minute. Under this condition, before the glass cloth was peeled from the heat-adhesive tape, whether the glass cloth was broken or not was performed. Evaluation of the shear force for the shear force. That is, regarding the adhesive force, before the glass cloth and the heat-adhesive tape are peeled off, when the glass cloth is broken, it means that the shearing force is greater than the breaking strength of the glass cloth. , Evaluated as unqualified.

[Method for evaluating insolubilized content before storage] Also, as the heat-bonding of the heat-adhesive tapes of Examples 1 to 8 and Comparative Examples 1 to 3, the evaluation of the curing speed of the adhesive layer was evaluated to evaluate the heat-adhesive tapes after heat-compression. Its insoluble content. Here, the insoluble content of the heat-adhesive tape refers to the weight ratio of the solvent-insoluble portion of the heat-adhesive tape relative to the total weight of the heat-adhesive tape. The product produced by the reaction of osmic acid and a phenol resin is insoluble in a solvent. Therefore, it is considered that the more the insoluble content of the heat-adhesive tape after the heat-compression bonding, the more acid is generated during the heat-compression bonding, and the reaction proceeds. The more acid is generated during thermal compression, the faster the layer hardens.

As a specific evaluation method of the insoluble content of the heat-adhesive tape after heat compression bonding, first prepare two pieces of release liners composed of polyethylene terephthalate, and sandwich the heat-adhesive tapes with the two pieces of release liners. The two release liners were bonded by heat and pressure bonding with heat-adhesive tape. In addition, the conditions of thermocompression bonding are the same as the conditions of thermocompression bonding in the force evaluation before storage. That is, a person who is ready to press at 160 ° C. and a pressure of 1.47 × 10 ⁵ N / m ² for 20 seconds, and is bonded to the release liner with a heat-adhesive tape, and a pressure of 170 ° C. and 1.47 × 10 ⁵ N / m ² , The pressing was performed for 10 seconds, and the release liner was bonded with heat-adhesive tape.

Next, the release liner was peeled from the heat-adhesive tape, and the weight of the heat-adhesive tape with the peeled release liner was measured, and the measured value was taken as W1. The weight of the heat-adhesive tape is about 0.1 g to 0.2 g. Then, this hot-adhesive tape was immersed in 10 g to 20 g of methyl ethyl ketone as a solvent, and stirred with a mix rotor for 24 hours. Next, the solution was filtered using a stainless steel mesh to extract the insoluble content of the heat-adhesive tape. The stainless steel mesh system uses 100 meshes. The weight of this screen when not in use is taken as the weight W2. Then, the remaining mesh of the insoluble component of the heat-adhesive tape was dried in an environment of 80 ° C. with an explosion-proof dryer, and then left to cool. Next, the weight of this screen was measured, and the measured value was made into W3. Then, the insoluble content calculated from ((W3-W2) / W1) was evaluated. In addition, with respect to the heat-adhesive tapes of Examples 1 to 8 and Comparative Examples 1 to 3, the insoluble content before thermal compression bonding was 0%.

[Method of Evaluating Adhesion After Storage] Also, the adhesion of the thermal adhesive tapes of Examples 1 to 8 and Comparative Examples 1 to 3 after storage for a certain period of time were evaluated. Specifically, regarding the heat-adhesive tapes of Examples 1 to 8 and Comparative Examples 1 to 3, after the production of these heat-adhesive tapes, they were stored in an environment at 80 ° C. for one week. Then, the two glass cloths were bonded with adhesive tape by the heat and pressure bonding under the same conditions as in the method of evaluating the adhesion force before storage, and then a shear force was applied to the two glass cloths as an adherend. An evaluation of this adhesion was performed.

[Method for evaluating insoluble content after storage] Furthermore, in order to evaluate the degree of hardening of the adhesive layer when the thermal adhesive tape was stored without thermal compression bonding, the thermal adhesive tapes of Examples 1 to 8 and Comparative Examples 1 to 3 were evaluated. Insoluble content after storage for a certain period of time. It is believed that the more insoluble content after thermal adhesive tape storage, the more acid is generated from the peroxide contained in the adhesive layer during storage, and the reaction proceeds. The more acid is generated during storage, the greater the degree of hardening of the adhesive layer before thermal compression bonding.

As a specific evaluation method of the insoluble content after storage of the heat-adhesive tape, regarding the heat-adhesive tapes of Examples 1 to 8 and Comparative Examples 1 to 3, after the production of these heat-adhesive tapes, the environment was 80 ° C. Store for one week, and consider the weight of the heat-adhesive tape after storage as W4. Then, by the same method as the method of evaluating the insoluble matter before storage, the insoluble matter of the heat-adhesive tape was extracted using a stainless steel mesh. However, in the evaluation of the insoluble content after storage, in order to evaluate the amount of acid generated during storage, the evaluation of the insoluble content before storage is different from the evaluation of the insoluble content before storage, and the insoluble content of the heat-adhesive tape that has not been heat-pressed is extracted. The weight of the sieve when it was not used was taken as the weight W5, and the weight of the sieve remaining after the insoluble content of the hot-adhesive tape was taken as the weight W6. Dissolved points.

[Evaluation Results] Table 1 shows the evaluation results of the adhesion. As shown in Table 1, the thermal adhesive tapes 1 of Examples 1 to 8 were produced by thermal compression bonding under any conditions, and all of them were acceptable for the adhesive force before storage and the adhesive force after one week of storage. In addition, the thermal adhesive tapes 1 of Examples 1 to 8 were produced by thermal compression bonding under any conditions, and the insoluble fraction before storage was greatly increased. It is considered that the curing system of the adhesive layer 3 during thermal compression bonding was promote. In addition, the increase in insolubilization of the heat-adhesive tape 1 after storage for one week is suppressed, and it is considered that the curing of the adhesive layer 3 during storage becomes difficult.

In contrast, in Comparative Examples 1 and 3, the thermal adhesive tape before storage was subjected to cohesive failure in the adhesive layer, and peeling of the thermal adhesive tape occurred. In addition, in Comparative Examples 1 and 3, regarding the heat-adhesive tape before storage, the insoluble fraction after heat-compression bonding hardly increased. In this regard, in Comparative Example 1, no peroxide was used at all, and in Comparative Example 3, although a peroxide was used, this peroxide did not generate an acid due to decomposition. Therefore, in both Comparative Example 1 and Comparative Example 3, no acid was generated during the thermal compression bonding of the heat-adhesive tape, the crosslinking of the phenol resin did not proceed sufficiently, and the curing of the adhesive layer was insufficient, so it was considered to be insufficient. Adhesion of the heat-adhesive tape to the adherend.

In Comparative Example 2, although the adhesive force of the thermal adhesive tape before storage was acceptable, the thermal adhesive tape after one week of storage was damaged at the interface of the adherend, and the thermal adhesive tape was peeled off. In addition, in Comparative Example 2, although the insoluble content of the heat-adhesive tape before storage was greatly increased after compression and compression, the insoluble content of the heat-adhesive tape after storage for one week increased significantly. It is believed that this is because during the storage of the heat-adhesive tape for one week, benzoic acid reacts with the phenol resin, the crosslinking of the phenol resin proceeds, and the curing of the layer proceeds. In addition, it is considered that after the curing of the adhesive layer has sufficiently progressed, even if the adherend is heated and pressure-bonded to the thermal adhesive tape, the adhesive force of the thermal adhesive tape to the adherend is not sufficiently obtained.

From the results of Examples 1 to 8 and Comparative Examples 1 to 3, it was confirmed that the adhesive layer 3 of the thermal adhesive tape 1 must contain a peroxide that generates an acid due to decomposition.

1‧‧‧Heat Adhesive Tape

2‧‧‧ peel liner

3‧‧‧ Adjacent layer

FIG. 1 is a cross-sectional view showing a heat-adhesive tape using this embodiment. FIG. 2 is a flowchart illustrating a manufacturing method of the adhesive tape.

Claims (5)

A thermal adhesive tape without a substrate, which is a thermal adhesive tape without a substrate, and is bonded to an adherent by heating and pressure bonding. The thermal adhesive tape includes an acrylonitrile-butadiene rubber, a phenol resin, and an acid produced by decomposition. Adhesive layer of peroxide and phenol resin crosslinking agent. For example, the baseless heat-adhesive tape of claim 1 further includes a release liner, which is provided on at least one side of the aforementioned adhesive layer and can be peeled from the adhesive layer. For example, the baseless thermal adhesive tape of claim 1 or 2, wherein the aforementioned peroxide-based half-life temperature is 130 ° C or higher and 170 ° C or lower. The substrate-free hot-adhesive tape according to any one of claims 1 to 3, wherein when the acrylonitrile-butadiene rubber is used as 100 parts by mass, the adhesive layer contains 0.5 to 5 parts by mass of the aforementioned peroxide. A method for manufacturing a substrate-free thermal adhesive tape, which is a method for manufacturing a thermal adhesive tape without a substrate and joining an adherent by heating and pressure bonding, comprising: (1) a step of preparing a release liner for preparing a release liner, and A solution for an adhesive layer containing acrylonitrile-butadiene rubber, a phenol resin, a peroxide that generates an acid due to decomposition, and a phenol resin cross-linking agent is applied to the release liner to form an adhesive layer forming step.