JPH08283671A - Adhesive film for surface protection - Google Patents

Abstract

PURPOSE: To obtain an adhesive film for surface protection excellent in cutting performance with a cutter and workability when applied on a base material made of an olefinic resin. CONSTITUTION: This adhesive film for surface protection has an adhesive layer on one face of a base material. The base material is composed of A layer and B layer, and the A layer contains hard segments and soft segments, whose compositions are shown below, and the B layer contains a polyolefinic resin. The hard segment consists of a polypropylene. The soft segment is a resin consisting of at least one selected from among (1) a propylene-ethylene copolymer, (2) a copolymer of propylene with α-olefin expressed by the formula CH2 =CHR (R is a 2-8C aliphatic group or an aromatic group) and (3) a copolymer of propylene with a diene compound.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to an adhesive film (adhesive film for surface protection) used for protecting the surface of a metal plate such as a stainless plate, an aluminum plate, a steel plate, a plastic plate or a coated plate of these. More specifically, the present invention relates to an adhesive film for surface protection, which has good workability by a cutter and excellent workability.

[0002]

2. Description of the Related Art When transporting or storing a member such as a metal plate such as a stainless steel plate, an aluminum plate, a steel plate, a plastic plate or a coated plate thereof, or cutting, punching, punching, bending or roll forming the member. When processing such as drawing, an adhesive film for surface protection is attached to the surface to prevent the surface from being soiled or scratched.

[0003]

As the above-mentioned adhesive film for surface protection, one using soft vinyl chloride as a base material is often used. Adhesive film for surface protection using soft vinyl chloride is less likely to cause film tearing, galling, floating, contamination of the protected object during processing of the object to be protected, and it is also difficult to tear when peeled and cut by a cutter. Good workability and excellent workability.

However, since the adhesive film for surface protection using soft vinyl chloride generates chlorine gas when it is incinerated when it is discarded after use, it can be discarded without incineration or, for example, for removing chlorine gas in an incinerator. However, there is a problem that it is necessary to install the device for incineration. Under these circumstances, it has recently been desired to convert the material of the base material of the surface protection adhesive film into an olefin resin.

Therefore, for example, it has been proposed to use a resin containing polypropylene and an olefin elastomer as the base material of the adhesive film for surface protection (see JP-A-6-220412).

However, the above-mentioned conventional adhesive film for surface protection using an olefin resin has a problem that workability is poor because it is difficult to cut with a cutter.

An object of the present invention is to solve the above problems and to provide an adhesive film for surface protection using an olefin resin as a base material, which has good cutting performance by a cutter and excellent workability. To provide.

[0008]

The present inventors have found that the above-mentioned problems can be achieved by the present invention described below. That is, the adhesive film for surface protection of the present invention has a pressure-sensitive adhesive layer on one surface of a base material, the base material has an A layer and a B layer, and the A layer is the following resin. Containing a hard segment and a soft segment, and the layer B contains a polyolefin resin. Hard segment: Polypropylene Soft segment: (1) Copolymer of propylene and ethylene, (2) Propylene and formula CH ₂ = CHR (however,
R represents an aliphatic group or an aromatic group having 2 to 8 carbon atoms), and one or more selected from copolymers with α-olefins and (3) copolymers of propylene and a diene compound. resin

Α- in the soft segment of the A layer
Preferred examples of the olefin include butene-1, pentene-1, 4-methylpentene-1, hexene-1, octene-1, and styrene.

Preferred examples of the diene compound include butadiene, 1,4-hexadiene, 1,5-hexadiene, ethylidene, norbornenediene and the like.

It is preferable that the hard segment and the soft segment in the resin exist in a state of good compatibility with each other, whereby the tearability and the stress relaxation property of the film are improved and the processability and the peelability are improved. It is preferable in terms. As a state of good compatibility as described above, a state in which a hard segment and a soft segment are bound by block copolymerization and exist in the same molecule, or IPN (interpenetrating network; in
An example is a state in which a structure such as a terpenetrating polymer network) is formed and the compatibility is good.

The content of the soft segment is 30 to 300 parts by weight, preferably 40 to 200 parts by weight, based on 100 parts by weight of the hard segment. When the soft segment is 30 parts by weight or more, the workability and tearability are good, while when it is 300 parts by weight or less, the influence of rubber elasticity is not excessive, and the workability and workability at the time of peeling are good. .

Examples of the polyolefin resin for the layer B include those containing polypropylene, polyethylene and the like. Among them, those containing polypropylene are particularly preferable from the viewpoint of cutting property by a cutter, and further, In this case, the content of polypropylene is 30 parts by weight or more, preferably 50 parts by weight or more.
If the content of polypropylene is 30 parts by weight or more, A
Adhesion between the layer and the B layer is good, and delamination between layers is unlikely to occur.

The thickness of the layer B is preferably greater than 0% and 25% or less of the substrate thickness. When the thickness of the B layer is 25% or less of the thickness of the base material, the workability of the film can be maintained at a good level, and the effect of the A layer is rarely impaired. The thickness of the layer B is preferably about 5 μm or more in terms of manufacturing stability.

As the method for producing the base material having the above-mentioned A layer and B layer, the resin material constituting each layer is melt-coextruded to form a laminate, or each layer is separately formed into a film by extrusion or the like. A method of adhering these with an adhesive or the like is exemplified, but a method of melt coextrusion is preferable in order to improve the adhesion between the respective layers and to simplify the process.

The polypropylene that can be used as the material for the hard segment and the soft segment in the A layer and the B layer is exemplified by homo, block and random polypropylenes.

The above resin may be titanium oxide, if necessary,
Inorganic fillers such as zinc oxide and calcium carbonate, amine-based, quinoline-based, hydroquinone-based, phenol-based, antioxidants and antioxidants such as phosphite-based, salicylic acid derivatives, benzophenone-based, benzotriazole-based,
One or more of hindered amine-based UV absorbers, lubricants, plasticizers and the like may be blended within a range not deviating from the gist of the present invention.

From the standpoint of workability, it is appropriate that the thickness of the above-mentioned substrate is usually about 30 to 200 μm. That is, the thickness of the base material is 30 in order to maintain proper strength during processing.
It is suitable that the thickness is about μm or more, and that the thickness is about 200 μm or less to make the residual stress moderate.

The pressure-sensitive adhesive forming the pressure-sensitive adhesive layer is as follows:
Adhesives known in the art such as acrylic adhesives and rubber adhesives can be used.

The thickness of the pressure-sensitive adhesive layer is usually preferably about 1 to 20 μm. The adhesive strength of the pressure-sensitive adhesive layer is 50 to 30.
About 0g / 20mm is suitable. The adhesive force of this pressure-sensitive adhesive layer was obtained by measuring at a temperature of 23 ° C. and a pulling speed of 300 mm / min.

The above-mentioned pressure-sensitive adhesive layer may be provided, for example, on the B layer 2 side of the substrate as shown in FIG. 1 or on the A layer 3 side as shown in FIG.

[0022]

EXAMPLES The present invention will be described in more detail with reference to the following examples. It should be noted that the present invention is not limited to these examples as a matter of course.

Example 1 As a resin constituting the layer A, a resin having 100 parts by weight of a hard segment made of polypropylene and 80 parts by weight of a soft segment made of ethylene-propylene rubber (trade name: KS-021P; manufactured by Highmont). , Homopolypropylene is used as the resin forming the B layer, and these resin materials are molded by melt coextrusion,
A two-layer film was obtained in which the A and B layers had a thickness of 100 μm and 8 μm, respectively. B of this two-layer film
Corona treatment was applied to the layer side surface. Then, using this two-layer film as a base material, an acrylic pressure-sensitive adhesive layer having a thickness of 5 μm was provided on the B layer side thereof to obtain an adhesive film for surface protection.

Examples 2 to 14 and Comparative Example 1 A substrate was prepared in the same manner as in Example 1 except that the resins and the thicknesses of the layers A and B were changed as shown in Tables 1 and 2, respectively. It produced and produced the adhesive film for surface protection. In the table, EPR indicates ethylene-propylene rubber, MFR indicates melt flow rate, and parts are parts by weight.

[0025]

[Table 1]

[0026]

[Table 2]

Example 15 A base material was prepared in the same manner as in Example 2 except that the surface of the two-layer film on the side of the A layer was subjected to corona treatment and the pressure-sensitive adhesive layer was provided on the side of the A layer, and the surface protection was performed. An adhesive film for use was produced.

(Evaluation of Surface Protective Adhesive Film) Each of the surface protective adhesive films prepared in Examples 1 to 15 was evaluated in the following points.
The result shown in FIG. [Workability] A 0.7 mm thick stainless steel plate (SUS-304BA) is pasted with an adhesive film for surface protection, pressure is applied with a 2 kg roller, and the diameter is 20 mm using a press machine (AIDA 60t press machine). Punching was performed at a pitch of 22 mm. At that time, the presence or absence of tearing, galling, and floating of the film was examined, and one in which none of these occurred was rated as ◯ and one in which at least one occurred. [Tearability] Measurement by Elemendorff according to JIS P 8116 (measurement conditions: substrate thickness 100 μm, 23
C.). [Cutability by Cutter] As shown in FIG. 3, the surface-protecting adhesive film wound in a roll is unrolled, and at that time, the blade (N
The T replaceable blade A) was installed so as to form an angle of 30 ° with respect to the film, and was cut when the film passed through the installation part of the cutter. The feeding speed of the film was 5 m / min, and a new blade was replaced each time the sample film was changed to another one.
In this operation, the length of the cut film was measured by the time when the cutting of the film started to deteriorate (when the cut surface of the film began to become rough).

[0029]

[Table 3]

The surface protection adhesive film prepared in Comparative Example 1 was evaluated for cuttability by a cutter in the same manner as above, and the film was about 100.
At the time of cutting, the cutting started to deteriorate.

[0031]

The adhesive film for surface protection of the present invention has a pressure-sensitive adhesive layer on one surface of a base material, the base material has an A layer and a B layer, and each A layer has the following structure. It contains a hard segment and a soft segment having a resin, and the layer B contains a polyolefin resin. Hard segment: Polypropylene Soft segment: (1) Copolymer of propylene and ethylene, (2) Propylene and formula CH ₂ = CHR (however,
R represents an aliphatic group or an aromatic group having 2 to 8 carbon atoms), and one or more selected from copolymers with α-olefins and (3) copolymers of propylene and a diene compound. resin

With the above-mentioned constitution, it is possible to obtain an adhesive film for surface protection using an olefin resin as a base material, which has good cutting performance by a cutter and excellent workability.

[Brief description of drawings]

FIG. 1 is a schematic view showing an example of a laminated structure of an adhesive film for surface protection of the present invention.

FIG. 2 is a schematic view showing another example of the laminated structure of the surface protective adhesive film of the present invention.

FIG. 3 is a schematic diagram showing a test method for cutting property of a surface protection adhesive film with a cutter.

[Explanation of symbols]

 1 Adhesive Layer 2 B Layer 3 A Layer S Adhesive Film for Surface Protection

Claims (2)

[Claims] 1. A hard segment and a soft segment each having a pressure-sensitive adhesive layer on one surface of a base material, the base material having an A layer and a B layer, each of the A layer having the following resin. And an adhesive film for surface protection, wherein the layer B contains a polyolefin resin. Hard segment: Polypropylene Soft segment: (1) Copolymer of propylene and ethylene, (2) Propylene and formula CH ₂ = CHR (however,
R represents an aliphatic group or an aromatic group having 2 to 8 carbon atoms), and one or more selected from copolymers with α-olefins and (3) copolymers of propylene and a diene compound. resin 2. The adhesive film for surface protection according to claim 1, wherein the soft segment is contained in an amount of 30 to 300 parts by weight based on 100 parts by weight of the hard segment.