JP2011231287A - Pressure-sensitive adhesive laminate exhibiting excellent releasability - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a laminate comprising a release layer, a substrate layer and a pressure-sensitive adhesive layer, which can be manufactured in a single step, exhibits releasing performances of an equal or superior level to conventional laminates obtained by applying a release agent and can be well unwound while hardly causing abnormality such as noise or the like.SOLUTION: The laminate having a "layer constitution" below is manufactured by a (T die) co-extrusion method having only one production step: a release layer as an outermost layer comprising a resin (POM) mainly composed of polyacetal; a substrate layer as an intermediate layer comprising a polyolefin resin mainly composed of polypropylene or polyethylene, a modified polyolefin resin, or (modified polyolefin resin/polyolefin resin); and a pressure-sensitive adhesive layer, as an innermost layer, comprising a pressure-sensitive adhesive resin based on a thermoplastic soft resin (plastomer or elastomer).

Description

Surface protective film or adhesive tape used for the purpose of protecting the surface of the product from scratches, dirt, corrosion, etc. by attaching it to a product (sheet, film) such as resin plastic, metal, glass, etc.

Conventional adhesive laminates (surface protective films, adhesive tapes, etc.) are composed of a release layer, a base film layer, and an adhesive layer, and these laminates are commercialized through a plurality of production steps. "First, base film is formed, then release agent (eg silicone) is coated on base film, and finally adhesive (eg acrylic) is applied and commercialized." Unnecessary raw material products, time loss, or waste of labor will occur before commercialization. As a result, the production price of conventional adhesive laminates (surface protective films or adhesive tapes) is expensive.

Conventional adhesive surface protective films or adhesive tapes are commercialized through multiple production processes as described in the above “Background Technology”, so unnecessary raw materials are used and wasteful labor and time are consumed. is doing. Therefore, the challenge is to eliminate the use of unnecessary raw materials, wasted labor, and wasted time during production. That is, the production process of the adhesive laminate is changed from a plurality of processes to a single process. In addition, unwinding of the obtained adhesive laminate should not cause any abnormalities such as noise and cause no practical problems.

Since the basic structure of the adhesive laminate is [peeling layer / adhesive substrate film layer / adhesive layer], in order to achieve this in a single step, the following summary of the invention “co-extrusion method of simultaneous lamination” is used. Is optimal. The gist of the present invention consists of a laminate including the following release layer (A), adhesive layer (B), base material layer (C), and adhesive layer (D), and the release layer (A) is a polyacetal resin ( POM) is positioned as the outermost layer, adhesive layer (B) is a polyolefin-based modified resin or olefin-based copolymer, and base material layer (C) is a polyolefin-based resin or polyester-based resin. As the adhesive layer (D), an adhesive resin containing a tackifier based on a thermoplastic soft resin (plastomer, elastomer) is disposed as the innermost layer, and this laminate is a single layer of T-die coextrusion method. It can be obtained directly in the process.
(A): a polyoxymethylene polymer (homopolymer or copolymer) having 80% or more formaldehyde
(B): polyolefin-based modified resin or olefin-based copolymer (C): thermoplastic polyolefin-based resin or polyester-based resin (D): adhesive resin based on thermoplastic soft resin (plastomer, elastomer), Or a mixture containing a tackifier or the like (layer structure): The ratio of the base layer (C) to the total laminate thickness is 40% or more, but the release layer, the adhesive layer, the base layer, and the adhesive layer The configuration is not limited to three layers or four layers, but may be a multilayer having more layers.

In the pressure-sensitive adhesive laminate of the present invention, a thermoplastic polyacetal resin is selected for the release layer, and a thermoplastic pressure-sensitive adhesive resin is selected for the pressure-sensitive adhesive layer. A laminate comprising an adhesive layer, and particularly a laminate excellent in the peelability of the outermost layer (back surface), can be realized by only a single step.

The adhesive laminate excellent in peelability of the present invention comprises a laminate comprising the following release layer (A), adhesive layer (B), base film layer (C) and adhesive layer (D), The release layer (A) is located on the outside with a polyacetal resin (POM) as the outermost layer, the adhesive layer (B) is a polyolefin-based modified resin or olefin copolymer, and the substrate layer (C) is a polyolefin-based resin. Alternatively, the polyester resin is positioned as an intermediate layer, and the adhesive layer (D) is disposed as an innermost layer of an adhesive resin containing a tackifier based on a thermoplastic soft resin (plastomer, elastomer). The laminate is obtained directly by a T-die coextrusion method.
(A): a polyoxymethylene polymer (homopolymer or copolymer) having 80% or more formaldehyde
(B): Polyolefin modified resin or olefin copolymer (C): Thermoplastic polyolefin resin or polyester resin (D): Adhesive resin based on thermoplastic soft resin (plastomer, elastomer) or Is a mixture containing a tackifier, and the present invention will be described in detail below. However, the present invention is not limited to the following examples unless it exceeds the gist.

A three-layer laminate having the structure shown in Table 1 was obtained by a T-die coextrusion method. Table 2 shows the peel test results of the obtained laminate.

The outer layer (compression bonding) cooling roll was replaced with the following, and a three-layer laminate was obtained in the same manner as in Example 1. The peel test results are shown in Table 2.
Surface roughness of cooling (crimping) roll: R0.1

A three-layer laminate was obtained in the same manner as in Example 1, except that the release layer resin was replaced with the following. The peel test results are shown in Table 2.
Polyacetal resin (11J): (MFR50, density 1.41, thickness 10)

A three-layer laminate was obtained in the same manner as in Example 3, except that the release layer resin was changed to the following. The peel test results are shown in Table 2.
Adhesive resin (SIS synthetic rubber): (MFR5.0, density 0.90, thickness 10)

The outer layer cooling roll was replaced with the following to obtain a three-layer laminate in the same manner as in Example 4. The peel test results are shown in Table 2.
Surface roughness of cooling roll: R0.1
[Comparative Example 1]

A three-layer laminate was obtained in the same manner as in Example 1 except that the following was used as the resin for the outer layer. The peel test results are shown in Table 2.
Outer layer resin: Polycarbonate (MFR 7.0, density 1.20, thickness 10)
[Comparative Example 2]

Table 2 shows the peel test results of the pressure-sensitive adhesive tape obtained by the conventional three-step method.
Adhesive layer: SIS synthetic rubber-1
Release layer: UV curable polyorganosiloxane release agent [Comparative Example 3]

Table 2 shows the peel test results of the pressure-sensitive adhesive tape obtained by the conventional three-step method.
Adhesive layer: SIS synthetic rubber-2
Release layer: UV curable polyorganosiloxane release agent

Claims (2)

It is obtained by a T-die coextrusion method, and is composed of a laminate including at least a release layer (A), an adhesive layer (B), a base material layer (C) and an adhesive layer (D) described below. ) Is the outermost layer with polyacetal resin (POM) positioned on the outside, the adhesive layer (B) is a polyolefin-based modified resin or olefin-based copolymer, and the base layer (C) is a polyolefin-based resin such as polyethylene or polypropylene Alternatively, a polyester resin such as polyethylene terephthalate is positioned as an intermediate layer, and the adhesive layer (D) is an innermost layer of an adhesive resin (including a tackifier) based on a thermoplastic soft resin (plastomer, elastomer). Surface protective film (A) arranged as: Formed from polyoxymethylene polymer with 80% or more, excellent peelability and heat resistance of 160 ° C or more Delamination. A polyoxymethylene polymer is a homopolymer of formaldehyde, a copolymer (copolymer) with a cyclic ether such as ethylene oxide, or a mixture thereof, and has a specific gravity of 1.30 or more and a melting temperature. Crystalline thermoplastic resin (B) with less branching at 160 ° C. or higher: acid-modified polyolefin resin based on thermoplastic polyolefin resin (polyethylene, polypropylene, etc.), or a combination of ethylene and vinyl acetate Adhesive layer (C) formed of a polymer (EVA, EMMA, etc.) for the purpose of preventing delamination between the outermost release layer (A) and the intermediate substrate layer (C): a thermoplastic polyolefin resin or Base film layer formed from polyester resin (D): Adhesive layer formed from thermoplastic resin (1), (2) or a mixture of these adhesive resins 1) synthetic rubber styrene-butadiene rubber, nitrile-butadiene rubber, butadiene rubber, isoprene rubber, butyl rubber, chloroprene rubber, silicone rubber ... etc., or their hydrogenated products.
(2) Mixture of soft resin (plastomer, elastomer) and tackifier: plastomer: polyolefin resin elastomer having a density of 0.93 gr / cm ³ or less: (olefin) ethylene propylene rubber, ethylene propylene rubber, etc. (styrene System) Styrene isoprene styrene block copolymer, etc., or hydrogenated products thereof.
Tackifier: terpene resin, rosin resin, etc. The surface protection film according to claim 1, wherein the outermost release layer (A) may be a smooth surface, but the surface protection film according to claim 1, which has been subjected to roughening such as satin or embossing, Or adhesive tape.