JPS63137841A - Support base material - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention is made of a polyvinyl chloride thin film having a polyolefin laminate layer, and is used for surface protection materials, adhesive tapes, etc. with excellent adhesive properties, or as a peelable material with excellent release properties. The present invention relates to a supporting base material from which tapes and the like can be obtained.

Conventional technology and problems Focusing on its properties such as weather resistance, oil resistance, and, in the case of metal plates processed by metal forming, strength and short stress relaxation time, A thin film or sheet made of polyvinyl chloride is often used as a supporting base material.

These surface protection materials and adhesive tapes are stored as rolls, and it is common practice to store them during the distribution process. In order to facilitate return, the back surface is subjected to a !II l property treatment.A silicone-based release agent or a polyvinyl alcohol/long-chain alkyl isocyanate-based release agent is generally used for the removal.

However, in polyvinyl chloride, 4Thll
Since the adhesive strength with the fi-resistant treated film is essentially poor, the releasable treated film is transferred and transferred to the adhesive surface during rolling, reducing the adhesive strength of the adhesive layer and contaminating the adherend. There was a problem. This problem causes a decrease in the quality of the adherend and additional problems in the cleaning process.

In addition, the plasticizer in polyvinyl chloride migrates and penetrates into the adhesive layer through blooming, etc., which plasticizes the adhesive layer and reduces its cohesive strength, resulting in the problem of contaminating the adherend as adhesive residue. there were.

These problems become particularly noticeable at high temperatures. For example, although the rate of transfer of plasticizer to the adhesive layer varies depending on the type and content of the plasticizer, it is so fast that it reaches a steady state in a few days under high temperature (60° C. ladle). There are many cases where the storage period of a rolled product such as a surface protection material is one year, and the product is exposed to a high temperature atmosphere during the summer. Therefore, the above-mentioned problems often occur in a fatal state, and overcoming them has been an important and long-standing problem.

However, it has not been overcome yet.

Means for Solving the Problem The inventors of the present invention have conducted extensive research to overcome this problem, and have discovered that the objective can be achieved by laminating polyvinyl chloride with polyolefin plastic. The present invention has been accomplished.

That is, the present invention provides a supporting base material made of a polyvinyl chloride thin film having a polyolefin laminate layer on one or both sides.

'f, ll for the working polyolefin laminate layer
Release-treated membranes exhibit excellent adhesion. Furthermore, the barrier effect of the polyolefin laminate layer prevents the plasticizer in the polyvinyl chloride from migrating to the adhesive layer and effectively prevents its plasticization.

Examples of Constituent Elements of the Invention In the present invention, the laminate layer 7 made of polyvinyl chloride provided on one or both sides of the leaf is formed of polyolefin plastic. The polyolefin plastics include polyethylene, polypropylene,
Typical examples include mixtures of these, ethylene-propylene copolymers, ethylene-vinyl acetate copolymers, and the like.

There are no limitations on the method of forming the laminate layer.

Typical examples include a method in which a film is pasted through an adhesive or the like, a method in which a resin solution using a solvent is applied and dried, and a method in which a molten resin is applied. Particularly, a method of applying a molten resin using a T-die extruder or the like is preferable in terms of manufacturing efficiency and quality of the supporting base material obtained.

The thickness of the laminate layer is suitably 1I O'6 or less, preferably 5 to 30'6, the thickness of the thin film made of polyvinyl chloride. If the thickness exceeds 1026, the properties of polyvinyl chloride will be impaired, and for example, during the drawing process in the sheet metal processing process, the adhesive layer will partially peel off (lift) and droplets may occur, making it difficult for the subsequent processing to proceed smoothly. may be harmed. On the other hand, if it is too thin, the barrier effect of the plasticizer may be poor, which is undesirable.

The support base material of the present invention is preferably used as a release tape made by subjecting it to 411 female treatment, as well as a form in which an adhesive layer is attached on the support base material, such as a surface protection material or an adhesive tape. It will be done.

In the latter case, the adhesive layer may be attached to the polyvinyl chloride surface or the polyolefin laminate surface. In other words, an adhesive layer is attached to the polyvinyl chloride surface,
The other laminated surface may be subjected to XII i treatment, or the laminated surface may be provided with an adhesive layer. When attaching an adhesive layer to the laminate surface, it is preferable to perform a surface treatment such as a corona discharge treatment method to increase the surface tension of the laminate layer in terms of adhesive strength with the adhesive layer. The desired surface tension of the laminate layer in this case is 40 dyn/cm or more. The method of attaching an adhesive layer to the laminate surface is particularly advantageous when the amount of blooming of the plasticizer in the polyvinyl chloride is large.

The amount of blooming of plasticizer in polyvinyl chloride is extremely large.
If it is necessary to treat the back of the base material for releasability due to the adhesive used, use a support base material with polyolefin laminate layers on both sides of a thin film made of polyvinyl chloride, and apply surface treatment to the back surface of the base material. It is preferable that an adhesive layer is attached to the laminated surface, and the other laminated surface is subjected to surface treatment as necessary to make it pH female. As a result, even in the rolled state, the laminate layer is interposed between the adhesive layer or releasable treated film and the polyvinyl chloride layer, and the plasticizer in the polyvinyl chloride increases the adhesive strength of the releasable treated layer 1. or the plasticizer is stuck to the adherend of the adhesive layer (migration and penetration from III+ is prevented).

Note that there are no particular limitations on the adhesive used.

The smell of the present invention is peeled off through the laminate layer! Since the #-treated film is strongly bonded, it is possible to use an adhesive having excellent adhesive strength with polyvinyl chloride, such as an acrylic adhesive.

Effects of the Invention Since the supporting base material of the present invention is made of a polyolefin laminate and a thin film of polyvinyl chloride having kidneys, Th1l female treatment with excellent adhesive strength can be applied through the laminate layer. Furthermore, migration of the plasticizer in polyvinyl chloride to the adhesive layer can be effectively prevented.

As a result, adhesive strength is maintained and adherends are not contaminated.
j1. Surface protection materials and adhesive tapes with excellent properties can be obtained. Further, even when exposed to high temperatures, it is possible to obtain a surface protection material or adhesive tape that is excellent in preventing transfer of a releasable treated film onto the adhesive surface and contamination of the adherend due to adhesive residue.

Examples Example 1 Low-density polyethylene (melt index: rvi I 22 g y' 10 A laminate layer having a thickness of 1Ovm was formed by extruding the laminate layer (softening point: 95°C), and the laminate surface was treated with a silicone release agent to obtain a support base material.

Example 2 A support base material was obtained according to Example 1 except that the thickness of the laminate layer was 25 μm.

Example 3 A supporting base material was prepared in the same manner as in Example 1, except that a polyvinyl chloride film with a thickness of 100 μm was used and the thickness of the laminate layer was 30 μm.

Example 4 Polypropylene (M122
A support base material was obtained in accordance with Example 1, except that 155°C) was used.

Comparative Example 1 A support base material was obtained by directly subjecting a polyvinyl chloride film to a releasability treatment according to Example 1 without adding a laminate layer.

Comparative Example 2 A support base material was obtained in accordance with Example 1, except that the thickness of the laminate layer was 30 νm.

Comparative Example 3 Ethylene-vinyl acetate copolymer (vinyl acetate content 19 weight 06, ~1115 g/1
0 minutes, softening point (VICAT) 59℃) 1 weight? 6. A toluene solution was applied to one side of the same polyvinyl chloride film as in Example 1 so that the solid content was 0.2 g/nt (thickness: 0.2 pm), dried, and subjected to releasability treatment according to Example 1. A supporting base material was obtained.

Evaluation Test An acrylic adhesive was applied to the polyvinyl chloride film surface of the support substrate obtained in the above Examples and Comparative Examples, and dried to form an adhesive layer with a thickness of 10 μm. An adhesive tape (surface protection material) was obtained by attaching 50 m'J to a ball core with a wall thickness of 3 mm and winding it into a roll.

Then, the following test was conducted on the obtained wound adhesive tape.

[Stress at 20% deformation] A sample with a width of 20M and a length of 100M is chucked at a chuck interval of 20mm.
at a speed of 300 mm/min, 20% (4 mm
) The stress when stretched was measured.

[Stress relaxation time at 20% deformation 1 A specimen with a width of 20 mm and a length of 10 mm was chucked at a chuck interval of 20 mm.
4M by pulling at a speed of 1000 mm/min, and then the time required for the stress to decay to 1/e% was measured.

[Rewinding force 1 JIS Z 0237! : Same as above, rewinding speed 300
The measurement was carried out under the condition of 0/min. Note that the initial product was not heat-treated, and the heated product was heat-treated at 60° C. for 7 days.

[Workability 1] Using the Erichsen drawing die shown in FIG. A workpiece having the form shown in the figure is visually observed to see if there is a peeling part (lifting) between the sample 4 and the stainless steel plate 5. It was evaluated as ×.

[Shelling property] After leaving the sample as a roll at 60°C for 7 days, unwind it and observe the adhesive surface with a scanning electron microscope. 1
000 times), and the presence or absence of transfers of the releasable treated film was evaluated, and the presence or absence of transfers was evaluated as ◯, and the presence of them as 8 to × (x means that transfers were significantly present).

The results are shown in Table 1.

In addition, L/P in the table means the thickness ratio of the laminate layer and the polyvinyl chloride layer.

Table 1 Example 5 Low-density polyethylene (melt index: M122 g/10 min, softening point 95 ℃) to form a laminate layer with a thickness of Ihm, and the surface of the laminate layer was treated with corona discharge to have a surface tension of 45 dyn/c.
m supporting base material i! Ta.

Example 6 Polypropylene (M122
A support base material was obtained in accordance with Example 5, except that the temperature was 155°C (g/10 minutes).

Example 7 Did you use ethylene-vinyl acetate copolymer instead of low-density polyethylene? M8 weight containing vinyl acetate? 6, MIL, 7g/10
A support base material was obtained in accordance with Example 5, except that a temperature of 74° C.) was used.

Comparative Example 4 The flexible polyvinyl film of Example 5 was used as it was as a supporting substrate.

Comparative Example 5 A 70 um thick soft polyvinyl chloride film containing 32 parts by weight of a polyester polymer plasticizer was used as it was as a supporting base material.

In the supporting base materials obtained in Evaluation Test Example 51617 and Comparative Examples 4 and 5, an acrylic adhesive was applied to the laminate surface in the example and the polyvinyl chloride film surface in the comparative example, and dried to give a thick A surface protective material was obtained by forming an adhesive layer with a thickness of 10 μm, and the following tests were conducted.

[Adhesive strength 1 Weather Ometer (Sunshine type, Shimabara Seisakusho 9) attached to a stainless steel plate (SUS 304 HA)
For those exposed for 500 hours or 700 hours using the same method (manufactured by JIS Corporation), or those that have been heat-treated at 60°C for 7 days, or those that have not been subjected to these treatments (initial products), according to JIS Z 0237 (tensile speed 300
mm/min> The adhesive force was measured.

The results are shown in Table 2.

Note that the unit of adhesive force in the table is g/20 mm.

Table 2 Book (X): The adhesive layer suffered cohesive failure, and adhesive residue was observed on the stainless steel plate.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of an Erichsen drawing die, and FIG. 2 is a sectional view of a workpiece.

Claims (1)

[Scope of Claims] 1. A supporting base material made of a polyvinyl chloride thin film having a polyolefin laminate layer on one or both sides. 2. The thickness of the laminate layer is 4 times the thickness of the polyvinyl chloride layer.
The supporting base material according to claim 1, which has a content of 0% or less. 3. The support base material according to claim 1, which is provided with an adhesive layer and is in the form of a surface protection material or adhesive tape. 4. The supporting base material according to claim 3, which is obtained by subjecting the surface of the laminate layer to a releasable treatment. 5. Claim 3, in which the laminate layer is surface-treated by a corona discharge method or the like, and an adhesive layer is attached thereon.
Supporting base material as described in section. 6. The support base material according to claim 3, wherein the adhesive layer is made of an acrylic adhesive.