JP2010144063A - Pressure-sensitive adhesive laminate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pressure-sensitive adhesive laminate 10 which is produced by extrusion molding, can be stuck to an adherend with good adhesion and can easily be peeled off if necessary. <P>SOLUTION: The pressure-sensitive adhesive laminate 10 is formed by multilayer coextrusion molding and comprises a back layer 11, a foamed layer 13 and a pressure-sensitive adhesive layer 19. The pressure-sensitive adhesive layer 19 comprises a mixture of a soft propylene polymer and isotactic polypropylene, wherein the soft propylene polymer has an ethylene component content of 0.1-30 mol% and an α-olefin component content of 0.1-30 mol%, and has a melting point of <120°C or no melting point as measured by differential scanning calorimetric analysis. The foamed layer 13 has an expansion ratio of 1.1-3.0, the pressure-sensitive adhesive laminate 10 has a total thickness of 200-500 μm, and the pressure-sensitive adhesive layer 19 has a thickness corresponding 5-40% of the total thickness. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a pressure-sensitive adhesive laminate, and more specifically, a bonded surface by adhering to a bonded surface having a low surface roughness, such as a molded product such as metal, glass, and plastic, a processed product, and a coated product. It is related with the adhesive laminated body which protects the damage | wound and dirt of this, and can be easily peeled off at the time of use.

  In the present specification, “ratio”, “part”, “%” and the like indicating the composition are based on mass unless otherwise specified, and the “/” mark indicates that they are integrally laminated. “LDPE” is an abbreviation, functional expression, common name, or industry term for “low density polyethylene” and “MFR” for “melt flow rate”.

  (Main use) The main use of the adhesive laminate of the present invention is to adhere to the surface of products such as building materials, daily necessities, stationery, home appliances, automobiles, various displays, packaging materials, cushioning materials, heat insulating materials, It is used as a soundproofing material. However, it is not particularly limited as long as it is used as a packaging material, a cushioning material, a heat insulating material, a soundproofing material, etc., in close contact with the surface of the product.

(Background Art) Conventionally, foams have a wide variety of uses such as packaging materials, cushioning materials, heat insulating materials, and soundproofing materials. Adhesive is applied to the surface of the foam to make an adhesive-processed foam product, or a foamed layer and an adhesive layer are laminated by coextrusion to make an adhesive laminate. It is also used for surface protection of metal plates and glass plates. However, in the production of the adhesive laminate, the conventional production method in which it is applied after being dissolved in an organic solvent has a large fire risk and environmental burden. Therefore, it is preferable that the production can be performed by extrusion molding without using a solvent and having few production steps, excellent molding processability and excellent economic efficiency. Moreover, since it is consumed in large quantities and is peeled off and discarded after use, it can be manufactured at a low cost, and it is also required to have a low environmental load even if it is incinerated after use. Furthermore, if an adhesive layer with good adhesion is used, it is usually manufactured and used in a wound state, so that wrinkles are generated at the time of manufacture, or it is rewound from the wound state at the time of use, so that it is wound and in contact with the adhesive layer. Difficult to peel off from the back layer (referred to as blocking phenomenon), difficult to unwind, and in severe cases, transfer to the surface on the back layer side where the adhesive layer contacts and remain, or the adhesive laminate breaks or supplies Becomes unstable, and there is a problem that workability and machine suitability deteriorate. Furthermore, although the adhesive and the adhesive layer have good adhesion to the surface, there are problems in that the heat resistance (heat aging resistance), weather resistance, etc. are poor and the adhesive force varies.
Therefore, the pressure-sensitive adhesive laminate can be manufactured by extrusion molding which does not use a solvent, has few manufacturing processes, is excellent in molding processability and is excellent in economic efficiency, and can be manufactured and post-processed in a wound state, and can be stored and stored. It can be easily rewound even after being distributed, can be attached to adherends with good adhesion, has excellent workability and mechanical suitability during use, and can be easily peeled off when there is little change in adhesive strength over time. Is required.

(Prior Art) Conventionally, a pressure-sensitive adhesive layer is provided on one surface of a porous substrate, and a specific polyalkylene-based laminate material (a), a laminate material (b), and a release agent are sequentially laminated on the other surface. An adhesive tape is known (see, for example, Patent Document 1). However, adhesive coating uses a solvent at the time of manufacture, so there are environmental problems, and there are many manufacturing processes, so the cost is high. In coating type adhesive products, the adhesive remains on the adherend, etc. There is also a problem that there is a problem of contamination.
Further, a conjugated diene of a polymer mainly composed of a conjugated diene compound having a vinyl bond content of 65 to 85% is formed on the smooth surface of the base material layer (c) having a smooth layer (b) on at least one surface of the foam (a). There is known a pressure-sensitive adhesive laminate obtained by laminating a pressure-sensitive adhesive layer (e) made of a hydrogenated diene polymer (d) in which a partial double bond is saturated by 80% or more (see, for example, Patent Document 2). ). However, those obtained by laminating an adhesive layer consisting of a foamed layer and a hydrogenated diene copolymer by coextrusion technology have problems in heat resistance stability, weather resistance, etc., and the adhesive strength increases with time, making peeling difficult. There is a drawback of becoming.

JP-A-63-33485 JP-A-11-61066

  In order to solve the above-described problems, the present inventors have made extensive studies and have completed the present invention. Its purpose is that it does not use a solvent, has few manufacturing processes, is excellent in molding processability, and can be manufactured by extrusion molding, and can be manufactured and post-processed in a wound state, stored and distributed. Adhesive laminate that can be easily rewound later and can be adhered to an adherend with excellent adhesion, excellent workability and mechanical suitability during use, and can be easily peeled off when there is little change in adhesive strength over time Is to provide.

In order to solve the above-mentioned problems, the pressure-sensitive adhesive laminate according to the invention of claim 1 is a pressure-sensitive adhesive laminate in which a back layer, a foam layer and an adhesive layer are sequentially laminated. And the adhesive layer contains an ethylene component content of 0.1 to 30 mol%, an α-olefin component content of 0.1 to 30 mol%, and has a melting point of 120 measured by differential scanning calorimetry. A soft propylene polymer having a melting point of less than 0 ° C. or a melting point is not observed.
In the pressure-sensitive adhesive laminate according to the invention of claim 2, the foamed layer is formed by foaming a composition comprising a thermoplastic resin and a chemical foaming agent simultaneously with the film formation by the multilayer coextrusion method, and the foaming ratio is 1.1 to 3.0 times.
The pressure-sensitive adhesive laminate according to the invention of claim 3 is such that the total thickness of the pressure-sensitive adhesive laminate is 200 to 500 μm, and the thickness of the pressure-sensitive adhesive layer is 5 to 40% of the total thickness of the pressure-sensitive adhesive laminate. It is a thing.

According to the first aspect of the present invention, no solvent is used, the number of manufacturing steps is small, the molding processability is excellent, and it is possible to manufacture by extrusion molding that is also excellent in economic efficiency. Can be easily rewound after storage and distribution, can be attached to the adherend with good adhesion, has excellent workability and mechanical suitability during use, and is easy to peel when there is little change in adhesive strength over time An adhesive laminate that can be peeled is provided.
According to the second aspect of the present invention, in addition to the effect of the first aspect, a pressure-sensitive adhesive laminate having more excellent buffering properties is provided.
According to this invention of Claim 3, in addition to the effect of Claims 1-2, the adhesion laminated body which has moderate rigidity is provided.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a cross-sectional view of an adhesive laminate showing one embodiment of the present invention.

  (Adhesive Laminate) As shown in FIG. 1, the adhesive laminate 10 of the present invention has a back layer 11, a foam layer 13 and an adhesive layer 19 laminated in this order. The pressure-sensitive adhesive laminate 10 is formed by a multilayer coextrusion molding method. The adhesive layer 19 is a soft propylene polymer.

  (Back layer) As the back layer 11, a thermoplastic resin, that is, a resin that reversibly softens at a high temperature can be applied. The thermoplastic resin is not particularly limited, and specific examples include, for example, polyolefin resins such as polyethylene and polypropylene, polyamide resins, polyester resins such as polybutylene terephthalate and polyethylene terephthalate, vinyl chloride, polyphenylene ether, Examples thereof include polyphenylene ether resins such as modified polyphenylene ether, styrene resins such as polystyrene and heat-resistant polystyrene, acrylic resins, acrylonitrile / butadiene / styrene resins, and polycarbonate. These resins may be used alone or in combination of two or more. Preferably, polyethylene resins such as low density polyethylene and ethylene copolymer having extrudability and moderate rigidity are preferable. Moreover, it is preferable also from the point of the prevention of a spear which will be described later.

  (Foaming layer) The foaming layer 13 is formed by foaming a composition comprising a thermoplastic resin and a foaming agent, preferably a chemical foaming agent, simultaneously with the film formation by the multilayer coextrusion method, and the foaming ratio is 1.1. ˜3.0 times.

  (MFR of foam layer) The foam layer 13 in the pressure-sensitive adhesive laminate of the present invention is constituted by adding a foaming agent to a base resin made of a thermoplastic resin. The base resin preferably has a low MFR exhibiting high melt strength and melt elasticity, and preferably has an MFR of 0.5 to 10.0 g / 10 min. If the MFR is less than this range, the expansion ratio cannot be obtained, and if it exceeds this range, the bubble shape becomes poor.

  (Foaming agent) The chemical foaming agent is preferably an inorganic foaming agent. Organic foaming agents are not preferred because they generate decomposition gases such as ammonia gas, nitrogen gas, and carbon monoxide gas, and decomposition residues and sublimation substances cause contamination and corrosion of processing machines and metal products. . As the inorganic foaming agent used in the present invention, a foaming agent composed of sodium hydrogen carbonate whose generated gas is carbon dioxide and water vapor is suitable.

  (Addition amount) In the present invention, the above foaming agent is added in the range of 0.1 to 2.0% by mass. More preferably, it is 0.2 to 1.0 mass% addition. If the amount is less than 0.1% by mass, the dispersion is poor and sufficient foaming cannot be obtained. If the amount exceeds 2.0% by mass, fine foaming cannot be realized, and may not easily occur during production. By adding 0.1 to 2.0% by mass of a foaming agent to the above base resin, a foamed layer having a foaming ratio of 1.1 to 3.0 times can be obtained. If the expansion ratio exceeds this range, closed cells are difficult to obtain, and the surface state becomes poor. By setting the expansion ratio to 1.1 to 3.0 times, a buffer function, handling suitability, and strength can be realized.

  (Meani) Extrusion molding method has a defect that when it is extruded from a die, resinous deposits (Mayani) such as extruded resin composition and its oxide are generated at the outlet (die lip) of the die. Must. By providing the back surface layer 11, it is possible to prevent the occurrence of resinous deposits on the die lip at the time of molding, and the productivity can be improved.

  The foaming agent is generally added to a desired concentration by mixing with the base resin using a high concentration master batch. What is necessary is just to determine the density | concentration of a masterbatch suitably so that the foaming agent density | concentration in the foaming layer 13 may become the range of 0.1-2.0 mass%. In addition, any of the back layer 11, the foam layer 13 and the adhesive layer 19 may be used as long as it does not affect the function. Additives such as ultraviolet absorbers, light stabilizers, colorants such as dyes and pigments, and the like may also be added.

  (Adhesive layer) The adhesive layer 19 is a soft propylene polymer.

  (Soft Propylene Polymer) The soft propylene polymer means a propylene polymer having a melting point of less than 120 ° C. or no melting point measured by differential scanning calorimetry. Here, the fact that the melting point is not observed means that a crystal melting peak having a heat of crystal melting of 1 J / g or more is not observed in the range of −40 ° C. to 200 ° C.

  As the soft propylene polymer, when the total of the propylene component, the ethylene component, and the α-olefin component is 100 mol%, the propylene-derived structural unit is 40 to 100 mol%, and the ethylene-derived structural unit is 0.1 to 30. The structural unit derived from mol% and α-olefin is contained in an amount of 0.1 to 30 mol%. Moreover, as an alpha olefin component, a C4-C20 alpha olefin is preferable at the following points.

  A soft propylene polymer containing a propylene component, an ethylene component, and an α-olefin component (preferably an α-olefin having 4 to 20 carbon atoms) with such a content is transparent, flexible, heat resistant, and compressive strain resistant. Sex can be obtained. Further, it is presumed that flexibility, heat resistance, and compression strain resistance prevent an increase in adhesive strength over time under high temperature storage.

  Further, preferably, in terms of transparency, flexibility, heat resistance, compression strain resistance, and tackiness, the constituent unit derived from propylene is 60 to 80 mol%, the constituent unit derived from ethylene is 12 to 23 mol%, and carbon. The structural unit derived from α-olefin of several 4 to 20 is in the range of 0 to 20 mol%.

  The soft propylene polymer of the present invention can be produced using a metallocene catalyst for the production of isotactic polypropylene. For example, Mitsui Chemical's Notio has been promoted, and one grade is selected as appropriate. Or it can blend and use.

  (Additives) The tacky layer 19 may be added with known tackifiers such as rosin and rosin derivatives, polyterpene resins, terpene phenol resins, petroleum resins, polyethylene waxes and the like within a range not affecting the function of the present invention. Good.

  (Manufacturing method) As a manufacturing method of the adhesion laminated body 10, there exist an inflation film forming method, a T-die film forming method, etc. If multilayer coextrusion molding is possible, it will not specifically limit. Furthermore, a multilayer coextrusion molding method in which three layers can be formed simultaneously is preferable, and an air-cooled top blown inflation film forming method is used.

(Thickness) The pressure-sensitive adhesive laminate 10 has a three-layer structure of a back layer 11 / a foam layer 13 / an adhesive layer 19, and a thickness of 200 μm to 500 μm is suitable. If it is less than 200 μm, the amount of bubbles contained is small, and the foaming feeling is insufficient.
The thickness of the adhesive layer 19 is preferably in the range of 5 to 40% of the total thickness of the adhesive laminate 10. If the thickness of the pressure-sensitive adhesive layer 19 is less than 5% of the total thickness, the pressure-sensitive adhesiveness may be insufficient and the back layer 11 / foamed layer 13 may not be supported, which is not preferable. On the other hand, if it exceeds 30%, the rigidity of the pressure-sensitive adhesive laminate is insufficient.

  EXAMPLES Hereinafter, although an Example and a comparative example demonstrate this invention further in detail, it is not limited to this. In addition, except a solvent, each composition of each layer is a mass part of solid content conversion.

(Example 1) As the back layer 11, the foam layer 13, and the adhesive layer 19, the following compositions were used, respectively, by a three-layer multilayer coextrusion molding, an air-cooled top blown film forming method, and a film forming temperature of 230 ° C. The adhesive layered product 10 of Example 1 in which the total thickness of the back layer 11 is 20 μm / the foam layer 13 is 230 μm / the adhesive layer 19 is a total thickness of 300 μm and the foam layer 13 has an expansion ratio of 2.0 times. Manufactured.
As the (back layer 11), 100 parts by mass of a low density polyethylene resin, Sumikasen G201F manufactured by Sumitomo Chemical Co., Ltd. (density = 0.919 g / cm ³ , MFR = 2.0 g / 10 min) was adjusted.
(Foamed layer 13) 97 parts by mass of low density polyethylene resin, Sumikasen G201F manufactured by Sumitomo Chemical Co., Ltd. (density = 0.919 g / cm ³ , MFR = 2.0 g / 10 min), manufactured by Nitto Chemical Industries, Ltd. 3 parts by mass of a blowing agent master batch and fine blow S-20N (20% master batch) were prepared.
As (adhesive layer 19), 100 mass parts of polyolefin elastomer, Notio PN-2060 (density = 0.868 g / cm ³ , MFR = 6 g / 10 min (230 ° C.)) manufactured by Mitsui Chemicals, Inc. was adjusted.
The adhesive strength of the pressure-sensitive adhesive laminate 10 of Example 1 to the methacrylic resin surface was 0.05 N / 25 mm, the unwinding force was very weak, and measurement was impossible due to peeling.

(Example 2) The pressure-sensitive adhesive laminate 10 of Example 2 was produced in the same manner as in Example 1 except that the following compositions were used as the back layer 11, the foam layer 13, and the pressure-sensitive adhesive layer 19, respectively.
As the (back layer 11), 100 parts by mass of a low density polyethylene resin, Sumikasen G201F manufactured by Sumitomo Chemical Co., Ltd. (density = 0.919 g / cm ³ , MFR = 2.0 g / 10 min) was adjusted.
(Foamed layer 13) 97 parts by mass of low density polyethylene resin, Sumikasen G201F manufactured by Sumitomo Chemical Co., Ltd. (density = 0.919 g / cm ³ , MFR = 2.0 g / 10 min), manufactured by Nitto Chemical Industries, Ltd. 3 parts by mass of a blowing agent master batch and fine blow S-20N (20% master batch) were prepared.
As (adhesive layer 19), 100 parts by mass of polyolefin elastomer, Notio PN-3560 (density = 0.866 g / cm ³ , MFR = 6 g / 10 min (230 ° C.)) manufactured by Mitsui Chemicals, Inc. was adjusted.
The adhesive strength of the pressure-sensitive adhesive laminate 10 of Example 2 to the methacrylic resin surface was 0.09 N / 25 mm, the unwinding force was very weak, and measurement was impossible due to peeling.

(Comparative Example 1) The back layer 11 is not used, and the foaming layer 13 and the adhesive layer 19 are respectively formed by the following composition using three-layer multi-layer coextrusion molding, an air-cooling top blown inflation film forming method, and a film forming temperature. At 230 ° C., the pressure-sensitive adhesive laminate 10 of Comparative Example 1 having a total thickness of 280 μm including three layers of the foam layer 13 of 230 μm and the pressure-sensitive adhesive layer 19 of 50 μm and the foam layer 13 having an expansion ratio of 2.0 was manufactured.
None (back layer 11).
As the (foaming layer 13), 97 parts by mass of low density polyethylene resin, Sumikasen G201F (density = 0.919 g / cm ³ , MFR = 2.0 g / 10 min) manufactured by Sumitomo Chemical Co., Ltd., manufactured by Nitto Chemical Industries, Ltd. 3 parts by mass of a blowing agent master batch and fine blow S-20N (20% master batch) were prepared.
As (adhesive layer 19), 100 mass parts of polyolefin elastomer, Notio PN-2060 (density = 0.868 g / cm ³ , MFR = 6 g / 10 min (230 ° C.)) manufactured by Mitsui Chemicals, Inc. was adjusted.
Since the laminated body does not have a back layer and a foamed layer appears on the surface, a large amount of burrs are generated on the die lip during production, resulting in roughening of the laminated body surface.
The adhesive strength of the pressure-sensitive adhesive laminate 10 of Comparative Example 1 to the methacrylic resin surface was 0.07 N / 25 mm, the unwinding force was very weak, and measurement was impossible due to peeling.

  (Evaluation Method) Using the adhesive laminates 10 of Examples 1 and 2 and Comparative Example 1, the buffer function was evaluated from the adhesive force, the unwinding force, and the expansion ratio.

  (Measurement method) Foaming magnification was determined by forming the pressure-sensitive adhesive laminates 10 of Examples and Comparative Examples and allowing them to stand at 23 ° C. for 1 day, then cutting in the thickness direction, photographing the cut surface with an optical microscope, and foaming. The expansion ratio was calculated from the area ratio of the foamed portion and the unfoamed portion of the layer 13. An expansion ratio of 1.1 to 3.0 is considered acceptable.

  Adhesive strength is a rubber roll (weight 2 kg, width 45 mm, roll diameter 95 mm) defined in JIS-Z-0237, with the adhesive layer 19 of the adhesive laminate 10 of Examples and Comparative Examples superimposed on a methacryl plate having a thickness of 3 mm. Using a rubber hardness of 80 ± 5 Hs), one reciprocal pressure bonding was conducted, and after 1 hour, the peel strength at 180 ° peeling was measured at a tensile speed of 300 mm / min to obtain the adhesive strength.

The unwinding force was cut out from the adhesive laminate 10 of Examples 1 and 2 with a width of 25 mm, and the two back layers 11 and the second adhesive layer 19 were overlapped. -With the test method based on -Z-0237 pressure-sensitive adhesive tape / pressure-sensitive adhesive sheet test method, the peel strength of 180 ° peel was measured at a tensile speed of 300 mm / min, and the unwinding force between the back layer 11 and the pressure-sensitive adhesive layer 19 was did. The unwinding force is an index of the unwinding property at the time of use. In order to draw out easily, it is necessary to set it as the rewinding force of 0.5 N / 25mm or less, Preferably it is 0.1 N / 25mm or less.
MFR in the specification is JIS-K-7210 (load 21.2 N, outflow amount for 10 minutes), and is a value at 190 ° C. except for what is indicated as 230 ° C.

(Evaluation results) In the pressure-sensitive adhesive laminates 10 of Examples 1 and 2, the production was satisfactory, the foaming ratio indicating buffering was also acceptable, and the adhesive strength was 0.05 and 0.09 N / 25 mm, respectively. All the forces were very weak and could not be measured due to peeling, and there were no problems in manufacturing, processing, and use in a wound form.
In Comparative Example 1, the adhesive force to the methacrylic resin surface was 0.07 N / 25 mm, the unwinding force was very weak, and measurement was impossible due to peeling. However, since there is no back layer, the foam layer is exposed on the surface, a large amount of burrs are generated on the die lip, continuous film formation is not possible, the adhesive laminate surface is extremely rough, and a practical product cannot be obtained. .

It is sectional drawing of the adhesion laminated body which shows one Example of this invention.

Explanation of symbols

11: Back layer 13: Foam layer 19: Adhesive layer

Claims (3)

In the pressure-sensitive adhesive laminate in which the back layer, the foam layer and the pressure-sensitive adhesive layer are sequentially laminated, the pressure-sensitive adhesive laminate is formed by a multilayer coextrusion molding method, and the pressure-sensitive adhesive layer has an ethylene component content of 0.1 to 30 mol%, A pressure-sensitive adhesive laminate comprising a soft propylene polymer having an α-olefin component content of 0.1 to 30 mol% and having a melting point of less than 120 ° C. or no melting point measured by differential scanning calorimetry . The foam layer is formed by foaming a composition comprising a thermoplastic resin and a chemical foaming agent simultaneously with the film formation by the multilayer coextrusion method, and the foaming ratio is 1.1 to 3.0 times. The pressure-sensitive adhesive laminate according to claim 1, which is characterized by: The total thickness of the said adhesion laminated body is 200-500 micrometers, and the thickness of the said adhesion layer is 5 to 40% of the total thickness of the said adhesion laminated body, The one in any one of Claims 1-2 characterized by the above-mentioned. Adhesive laminate.

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