JP7249825B2 - Resin composition for thermal adhesive sheet, thermal adhesive sheet using the same, and method for producing the same - Google Patents

Description

TECHNICAL FIELD The present invention relates to a resin composition for thermal adhesive sheets that exhibits high adhesiveness when heated, a thermal adhesive sheet using the resin composition, and a method for producing the same.

In recent years, hot-melt adhesives have come to be widely used because of their high work efficiency, solvent-free nature, environmental friendliness, and beautiful finish. The resin used can be selected according to the adherend, such as EVA, olefin, or rubber. Various shapes are supplied according to the application, including sheet shapes that are easy to bond.

As a sheet-shaped hot melt, there has been proposed a heat adhesive tape provided with an adhesive layer composed mainly of an elastomer, a tackifier and a softening agent, which is suitable for bonding cloth substrates together (Patent Reference 1). However, the adhesive tapes blended in the examples of this document do not have sufficient weather resistance. When the transmittance and the transmittance are controlled, the values may not be stable, and there is room for improvement.

JP-A-2002-241717

The present invention has excellent weather resistance and heat resistance, can easily disperse pigments such as titanium oxide and carbon black, and has initial adhesiveness. The object of the present invention is to provide a thermoadhesive sheet resin composition that exhibits high adhesiveness, a thermoadhesive sheet using the same, and a method for producing the same.

The invention according to claim 1 comprises a hydrogenated styrene-butadiene block copolymer (A), a hydrogenated petroleum resin (B), and a plasticizer (C) having an alicyclic skeleton, wherein (A) is A heat-adhesive sheet characterized in that it is amine-modified or maleic anhydride-modified, and the ratio of (A) to the total solid content of the composition (excluding pigment (D)) is 40 to 58% by weight. A resin composition is provided.

The invention according to claim 2 comprises a hydrogenated styrene-butadiene block copolymer (A), a hydrogenated petroleum resin (B), and a plasticizer (C) having an alicyclic skeleton, wherein (A) is Provided is a resin composition for thermal adhesive sheets, wherein the resin composition is amine-modified or maleic anhydride-modified, and the (C) is 1,2-cyclohexanedicarboxylic acid diisononyl ester .

The invention according to claim 3 further provides the resin composition for thermal adhesive sheets according to claim 1 or 2, further comprising titanium oxide and/or carbon black as the pigment (D).

The invention according to claim 4 provides an adhesive sheet comprising the resin composition for thermal adhesive sheets according to any one of claims 1 to 3.

Further, the invention according to claim 5 is a heat adhesive sheet, wherein the heat adhesive sheet resin composition according to any one of claims 1 to 3 is dissolved in a solvent, applied to a substrate, dried and processed into a sheet. A manufacturing method is provided.

The resin composition of the present invention has excellent weather resistance and heat resistance, can easily disperse pigments such as titanium oxide and carbon black, has initial adhesiveness, and can be used to bond adherends. It is useful as a heat-adhesive sheet because it develops high adhesiveness by heating after drying.

The present invention will be described in detail below.

The sheet resin composition of the present invention comprises a hydrogenated (hereinafter referred to as hydrogenated) styrene-butadiene block copolymer (A), a hydrogenated petroleum resin (B), and a plasticizer (C) having an alicyclic skeleton. be.

The hydrogenated styrene-butadiene block copolymer (A) used in the present invention is obtained by hydrogenating a block copolymer consisting of a hard segment polystyrene block and a soft segment polybutadiene and further modifying it with an amine or maleic anhydride. It is a thermoplastic polymer that exhibits rubber elasticity over a wide range of temperatures. Compared to non-hydrogenated styrene-butadiene block copolymer (hereinafter referred to as SBS), it is particularly superior in weather resistance, heat aging resistance, and low-temperature processability.

The above (A) may be partially hydrogenated, but a completely hydrogenated one is preferred because of its excellent weather resistance and heat resistance. Further, by modifying with amine or maleic anhydride, the compatibility with various fillers is improved, and the tackiness and adhesive strength when formed into a sheet are improved. Unhydrogenated SBS is unacceptable because the initial adhesiveness may be insufficient, and when a translucent adherend is adhered, the adhesive strength may decrease over time. Commercially available products include the Tuftec MP series (product name: hydrogenated amine-modified SEBS manufactured by Asahi Kasei Corporation) and the same M series (hydrogenated maleic anhydride-modified SEBS).

The styrene ratio of (A) is preferably 15 to 70% by weight, more preferably 18 to 40% by weight, particularly preferably 20 to 35% by weight. Sufficient tensile strength can be secured at 18% by weight or more, and sufficient elastic force can be secured at 70% by weight or less.

The ratio of (A) to the total solid content of the composition (excluding pigment (D)) is preferably 40 to 58% by weight, more preferably 45 to 55% by weight. By making it 40% by weight or more, it is possible to ensure sufficient cohesive strength when formed into a sheet, and by making it 58% by weight or less, it is possible to ensure sufficient adhesive strength and shear adhesive strength.

The hydrogenated petroleum resin (B) used in the present invention is colorless and transparent, has excellent weather resistance and heat resistance, and is blended to impart sufficient adhesiveness when formed into a sheet. For example, it can be obtained by hydrogenating dicyclopentadiene (hereinafter referred to as DCPD), aliphatic (C5) and aromatic (C9) raw materials, and can be used alone or in combination of two or more. Among these, those having more excellent weather resistance and heat resistance and having a colorless alicyclic skeleton are preferable, and commercially available products include the Alcon P series (trade name: manufactured by Arakawa Chemical Co., Ltd.) and the T-REZ H series (trade name: JXTG). energy company) and so on.

The ratio of (B) to the total solid content of the composition (excluding pigment (D)) is preferably 30 to 55% by weight, more preferably 35 to 50% by weight. When the amount is 30% by weight or more, sufficient adhesive strength and shear adhesive strength can be secured, and when the amount is 55% by weight or less, sufficient cohesive strength can be secured even when formed into a sheet.

The plasticizer (C) having an alicyclic skeleton used in the present invention has good compatibility with the above (A) and (B), has excellent weather resistance and heat resistance, and has flexibility in the film. It is added to give stickiness. Examples thereof include 1,2-cyclohexanedicarboxylic acid diisononyl ester obtained by hydrogenating isononyl phthalate, and commercially available products such as Hexamoll DINCH (trade name: manufactured by BASF Japan).

The ratio of (C) to the total solid content of the composition (excluding pigment (D)) is preferably 3 to 20% by weight, more preferably 4 to 15% by weight. When the amount is 3% by weight or more, the flexibility of the film can be improved, and when the amount is 20% by weight or less, sufficient cohesive force can be secured even when formed into a sheet.

The configuration of the sheet composition of the present invention preferably further contains a pigment (D). Examples of pigments include titanium oxide and zinc white as white pigments, red lead and iron oxide red as red pigments, yellow lead and zinc yellow as yellow pigments, and carbon black as black pigments. In particular, when bonding translucent materials, depending on the application, low transmittance or high reflectance may be required as optical properties in the laminated state after bonding. When low transmittance is required, carbon black, When high reflectance is required, it is preferable to blend titanium oxide.

When the above (D) is blended, the blending amount is 80 to 110 parts by weight of titanium oxide with respect to 100 parts by weight of the total solid content of the composition excluding (D). In the case of carbon black, a sufficiently low transmittance can be obtained by blending 5 to 15 parts by weight.

The sheet composition of the present invention may optionally contain antioxidants, inorganic fillers, organic fine particles, surfactants, thickeners, coupling agents, ultraviolet absorbers, and light stabilizers, as long as the adhesive performance is not impaired. Additives such as can be blended.

The thermal adhesive sheet of the present invention is obtained by dissolving the composition in a good solvent such as toluene, applying the solution to the base film, drying it, and then laminating a protective film. It is preferable to form a laminated sheet having a three-layer structure of films. Although the thickness of the adhesive layer is exemplified as 30 to 200 μm, it is not particularly limited and can be freely set depending on the application and the type of adherend. The base film and protective film to which the composition is applied are not particularly limited as long as they can be peeled off later, but in terms of availability, cost, and workability during coating and lamination, release-treated polyethylene terephthalate film (hereinafter referred to as release PET) is preferred.

The thermal adhesive sheet of the present invention can be used by peeling off the protective film, applying pressure while preheating, and bonding it to the first adherend, then peeling off the base film and further bonding the second adherend. match. The preheating temperature is exemplified at 40 to 60° C., and the pressurizing method can be conventional methods such as roll lamination, vacuum lamination, autoclave, and heat press. After bonding the two adherends together, heat treatment is further performed to soften the adhesive layer and improve adhesion to the adherend. As the heat treatment temperature, for example, 100° C. for 5 minutes can be exemplified. As a guideline, sufficient adhesive force can be exhibited by softening the adhesive layer to a temperature of 100° C. or higher.

Hereinafter, the present invention will be described in detail based on Examples and Comparative Examples, but these are specific examples and are not particularly limited to these. Unless otherwise specified, the measurement was performed at a room temperature of 25° C. and a relative humidity of 65%. In addition, a compounding quantity shows a weight part.

Example 1
In a container, Tuftec MP10 (trade name: manufactured by Asahi Kasei Corporation, hydrogenated amine-modified SEBS, styrene ratio 30%) as (A), and T-REZ HB125 (trade name: JETG Energy Co., Ltd.) as (B) Hydrogenated DCPD / C9 system), Hexamoll DINCH (trade name: BASF Japan Co., Ltd., 1,2-cyclohexanedicarboxylic acid diisononyl ester) as the (C), and Sumilizer GP (trade name: Sumitomo Chemical) as an antioxidant. , Phenolic phosphorus antioxidant) was added in the amount shown in Table 1, and toluene was added so that the solid content was 40%.

Examples 2-7
In addition to the materials used in Example 1, Tuftec M1913 (trade name: manufactured by Asahi Kasei Corporation, hydrogenated maleic anhydride-modified SEBS, styrene ratio: 30%) and M1943 (trade name: manufactured by Asahi Kasei Corporation) are used as (A). , hydrogenated maleic anhydride-modified SEBS, styrene ratio 20%), Alcon P90 (trade name: Arakawa Chemical, alicyclic saturated hydrocarbon resin) as (B), and MA600 (trade name) as (D). Carbon black, manufactured by Mitsubishi Chemical Corporation) and TIOXIDE TR92 (trade name, titanium oxide manufactured by Huntsman) were added in the amounts shown in Table 1, and toluene was added so that the solid content reached 40%, followed by mixing and stirring. Resin compositions of Examples 2 to 7 were prepared.

Comparative Examples 1-5
In addition to the materials used in the examples, Tuftec H1517X (trade name: manufactured by Asahi Kasei Corporation, hydrogenated non-modified SEBS, styrene ratio 43%) and Tuftec P2000 (trade name: manufactured by Asahi Kasei Corporation, partially hydrogenated SEBS) are used as elastomer components. unmodified SBS, styrene ratio 67%), SBS TR2787 (trade name: JSR, non-hydrogenated unmodified SBS, styrene ratio 30%), Mobital B60H (trade name: Kuraray Co., butyral resin), and APEL6509T ( Trade name: Cycloolefin Polymer manufactured by Mitsui Chemicals, Inc.) is added in the amount shown in Table 1, and toluene is added so that the solid content becomes 40%, and mixed and stirred to prepare resin compositions of Comparative Examples 1-5. bottom.

Preparation of thermal adhesive sheet for evaluation The resin composition obtained above was uniformly coated on a release PET film (50 µm) so that the thickness after drying was 100 µm, and then heated in an oven at 110°C for 5 minutes. It was dried for a minute, and the toluene was volatilized to obtain an evaluation sample.

The evaluation method was as follows.

Mixed solubility: When the composition was dissolved in toluene, all the solids were dissolved and dispersed in a uniform state.

Adhesiveness of the film: Make the above sheet, check the adhesiveness by touch with toluene in a state where toluene is volatilized. The case where there is a sticky feeling but does not stick is evaluated as ◯, and the case where there is no tackiness to the touch is evaluated as x.

Shear adhesive strength: Cut out the sheet to 5 mm × 5 mm, attach it to a plate glass of 60 mm × 25 mm × 2 mm in thickness, further bond the plate glass together using a spacer with a thickness of 100 µm so that the adhesive layer thickness is 100 µm, 100 ° C. × 10 After heating for 1 minute and returning to room temperature, the shear adhesive strength was measured at a tensile speed of 5 mm/minute.

Film transmittance/reflectance: Using a spectrophotometer manufactured by JAFCO, light of 400 to 780 nm was applied to measure the average reflectance and average transmittance for each wavelength.

Evaluation results Evaluation results are shown in Table 2.

The resin compositions of Examples gave good results in all evaluation items of mixing/solubility, film tackiness, shear adhesive strength, film transmittance and reflectance.

On the other hand, Comparative Examples 1 and 2, in which non-modified SEBS was blended instead of (A), and Comparative Example 3, in which non-hydrogenated SBS was used, were inferior in shear adhesive strength. Comparative Example 5, which was insoluble and used a cycloolefin polymer, was inferior in film tack and shear adhesion, both of which were unsuitable for the present invention.

The resin composition of the present invention has excellent moisture resistance and weather resistance, can easily disperse pigments such as titanium oxide and carbon black, and has excellent initial tackiness and adhesiveness after heating. Therefore, it is useful as a resin for thermal adhesive sheets.

Claims (5)

A hydrogenated styrene-butadiene block copolymer (A), a hydrogenated petroleum resin (B), and a plasticizer (C) having an alicyclic skeleton, wherein (A) is amine-modified or maleic anhydride-modified A resin composition for a heat adhesive sheet, wherein the ratio of (A) to the total solid content of the composition (excluding the pigment (D)) is 40 to 58% by weight. A hydrogenated styrene-butadiene block copolymer (A), a hydrogenated petroleum resin (B), and a plasticizer (C) having an alicyclic skeleton, wherein (A) is amine-modified or maleic anhydride-modified and (C) is 1,2-cyclohexanedicarboxylic acid diisononyl ester . 3. The resin composition for a thermal adhesive sheet according to claim 1, further comprising titanium oxide and/or carbon black as a pigment (D). An adhesive sheet comprising the resin composition for thermal adhesive sheets according to any one of claims 1 to 3. A method for producing a thermal adhesive sheet, wherein the thermal adhesive sheet resin composition according to any one of claims 1 to 3 is dissolved in a solvent, applied to a substrate, dried and processed into a sheet.