JPS63175088A - Film substrate for protecting synthetic resin board and protective film - Google Patents

Abstract

PURPOSE:To obtain a film substrate, capable of protecting the surfaces of synthetic resin boards, e.g. acrylic plates, etc., by applying thereto, by forming a film from a blend of high-density PE with a low crystalline elastomer of ethylene-alpha.olefin copolymer at a specific ratio. CONSTITUTION:The aimed film substrate obtained by melt forming a film from a blend of (A) 70-90wt.% high-density PE having particularly preferably a density within the range of 0.945-0.960 with (B) 30-10wt.% low crystalline elastomer of ethylene-alpha.olefin copolymer having preferably about 0.87-0.89 density by an inflation, T-die method, etc. The thickness of the above-mentioned film substrate is preferably about 15-80mum. If a pressure-sensitive or heat- sensitive adhesive layer is provided on the afore-mentioned substrate, a film for protecting synthetic resin boards is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a surface protection film base material for attaching to the surface of a synthetic resin board such as an acrylic board to protect the surface thereof;
The present invention also relates to a surface protection film using the film base material.

Prior Art For acrylic boards, vinyl chloride boards, polycarbonate boards, polystyrene boards, ABS boards, and various decorative boards, it is important for the product value that the surface be smooth and beautiful.

Therefore, in order to prevent the surface of the synthetic resin board from being damaged during storage or transportation, a surface protection film is attached to one or both sides of the synthetic resin board.

Conventionally used surface protection films are based on films made of polyethylene, polypropylene, polyvinyl chloride, etc., and one side is coated with a hot-melt pressure-sensitive adhesive such as ethylene-vinyl acetate copolymer or a rubber-based pressure-sensitive film. A protective film coated with an adhesive or an acrylic pressure-sensitive adhesive is known.

Synthetic resin plates are often subjected to cutting with a protective film still attached to their surfaces. In such cases, it is required that the attached protective film does not adversely affect the machinability, but it is best to use high-density polyethylene film as the base film for the protective film. It is said to have excellent suitability for cutting.

Problems to be Solved by the Invention However, the above-mentioned polyethylene, polypropylene,
When a protective film based on polyvinyl chloride or other film is attached to a synthetic resin board.

There is a problem in that synthetic resin boards tend to slip when stacked, and especially when these protective films are pasted on both sides of synthetic resin boards and then piled up for storage or transportation, the surfaces of the protective films overlap each other. Therefore, it becomes extremely slippery, and as a result, the load may collapse, posing a danger to workers and causing damage to the product.

When a high-density polyethylene film was used as the base film in consideration of suitability for cutting, the above-mentioned slippage phenomenon was particularly significant.

In order to avoid such troubles, attempts have been made to reduce slipperiness by using a matte film with fine irregularities on the surface of the protective film, but this has not provided a fundamental solution.

In view of these circumstances, the present invention aims to improve the excessive slipperiness caused by using high-density polyethylene by improving the polymer composition, while ensuring suitability for cutting by using high-density polyethylene. be.

Means for Solving the Problems The synthetic resin board protective film base material of the present invention is a blend of 70 to 90% by weight of high-density polyethylene and 30 to 10% by weight of an ethylene-alpha olefin copolymerized low-crystalline elastomer. It is made by forming a film.

Moreover, the synthetic resin board protective film of the present invention has a structure in which a pressure-sensitive or heat-sensitive adhesive layer is provided on one side of this specific film base material.

The present invention will be explained in detail below.

The synthetic resin board in the present invention refers to a board whose at least the surface is made of synthetic resin, such as polyacrylic board,
PVC board, polycarbonate board, polystyrene board,
Single-layer synthetic resin boards manufactured by extrusion or cast molding such as ABS boards, phenolic resin laminates,
Mainly industrial A-laminates such as epoxy resin laminates, melamine resin laminates, urea resin laminates, unsaturated polyester resin laminates, silicone resin laminates, furan resin laminates, diallyl phthalate resin laminates, l-melamine Resin decorative phenolic resin laminate, melamine resin decorative amine resin A-layer board, melamine resin decorative plywood,
Epoxy resin decorative phenolic resin laminate, unsaturated polyester resin decorative plywood, unsaturated polyester resin decorative board,
Decorative boards such as diallyl phthalate resin decorative plywood, vinyl chloride resin decorative plywood, and various painted boards.

Acrylic plates (ie polymethyl methacrylate plates) are particularly important.

In the present invention, a film made of a mixture of high-density polyethylene and an ethylene-α/olefin copolymerized low-crystalline elastomer is used as a base material for a protective film that is attached to one or both sides of such a synthetic resin board. Use.

The reason why high-density polyethylene is used as the main polymer component is that the cutting processability of the synthetic resin plate to which the high-density polyethylene film is attached is superior to that of other films, such as protective films with base films such as polyethylene, polypropylene, and polyvinyl chloride. This is because the performance is better than when the paper is pasted.

Here, high density polyethylene has a density of 0.930
~0.965 is suitable, and considering the above-mentioned suitability for cutting, especially 0.945 ~ 0.980
It is preferable that it is in the range of .

The density of the ethylene-α/olefin copolymer low crystalline elastomer blended into high-density polyethylene is 0.8.
Commercially available ethylene-α/olefin copolymerized low-crystalline elastomers, which are preferably about 7 to 0.88, include, for example, "Tafmer" manufactured by Mitsui Petrochemical Industries, Ltd.; Examples include ``Urtzex'' manufactured by Petrochemical Industry Co., Ltd.

The blending ratio of i1 degree polyethylene and ethylene-α/olefin copolymer low crystalline elastomer is 1
00% by weight, the former needs to be 70 to 90% by weight and the latter needs to be 30 to 10% by weight; if the latter is less than 10% by weight, the slipperiness cannot be sufficiently improved. On the other hand, if the proportion of the contact exceeds 30% by weight, the cutting workability of the synthetic resin plate to which the protective film is attached will be poor.

! When a blend of dense polyethylene and an ethylene-α/olefin copolymerized low-crystalline elastomer is subjected to melt film formation, the desired film base material can be obtained. As the melt film forming method, an inflation method, a T-die method, etc. are adopted.

The thickness of the film base material is not particularly limited, but in consideration of suitability for use and economic efficiency, it is appropriate to set it to about 15 to 80 gm.

By providing a pressure-sensitive or heat-sensitive adhesive layer on this film base material, a synthetic resin board protective film can be obtained.

The pressure-sensitive adhesive layer can be installed by dissolving the pressure-sensitive adhesive in a suitable solvent, applying it to the film substrate, and drying it, or by coating the film substrate with the pressure-sensitive adhesive in a molten state. can also be achieved.

As the pressure-sensitive adhesive, any of the hot-melt pressure-sensitive adhesives, rubber-based pressure-sensitive adhesives, acrylic pressure-sensitive adhesives, etc. that have been conventionally used for this purpose can be used.

The amount of pressure sensitive adhesive applied to the film base material is based on dry standard Te2.
Although it is often set in the range of ~25 g/m', particularly 3~20 g/m'', it is not necessarily limited to this range.

When forming a heat-sensitive adhesive layer, it can be achieved, for example, by melting the heat-sensitive adhesive and extrusion coating it on the film base material.

Examples of heat-sensitive adhesives include ethylene-vinyl acetate copolymer resins containing 10 to 20% vinyl acetate, ethylene-vinyl acetate hot melt adhesives, and styrene-butadiene-based adhesives.
One or more of styrene copolymers, styrene-isoprene-styrene copolymers, and ethylene-propylene terpolymers can be suitably used, but it is easier to use ethylene-vinyl acetate copolymer resins. Most preferable considering.

The amount of heat-sensitive adhesive applied to the film base is 5 to 50 g/
Although the thickness is often set in a range of about 5 to 607 tm, it is not necessarily limited to this range.

Function: To adhere the protective film obtained as described above to a synthetic resin plate, the protective film may be applied to the synthetic resin plate and pressed with a roll.

The protective film base material of the present invention maintains the excellent machinability of high-density polyethylene, while
The blended ethylene-α/olefin copolymerized low-crystalline elastomer reduces slipperiness to an appropriate level.

Moreover, the transparency of the film base material is not significantly reduced by blending the ethylene-α/olefin copolymerized low-crystalline elastomer, and the observation of the surface of the synthetic resin plate is not hindered.

Example Next, the present invention will be further explained with reference to Examples.

Hereinafter, "parts" refer to parts by weight.

Example 1 85 parts of high-density polyethylene with a density of 0.953 (Santic S-3EIOJ, manufactured by Asahi Kasei Industries, Ltd.) and an ethylene-α/olefin copolymerized low crystalline elastomer with a density of 0.880 (manufactured by Mitsui Petrochemical Industries, Ltd.) "Tafmer A4058J)" was mixed with 15 parts, and a film with a thickness of 30 pm was produced by an inflation method, and used as a film base material.

In addition, an acrylic pressure-sensitive adhesive was applied to one side of this film base material, and the drying rate was 8 g/rr? A pressure-sensitive adhesive layer was provided to form a protective film.

Example 2 80 parts of high-density polyethylene with a density of 0.95 (Hyzex 3300FJ, manufactured by Mitsui Petrochemical Industries, Ltd.) and an ethylene-α/olefin copolymerized low crystalline elastomer with a density of 0.88 (manufactured by Mitsui Petrochemical Industries, Ltd.) ``Urtzex 2080CJ)'' was mixed with 20 parts, and a film with a thickness of 307 zm was produced by the inflation method.
It was used as a film base material.

Further, an acrylic pressure-sensitive adhesive was coated on one side of this film base material to provide a pressure-sensitive adhesive layer of 8 g/m'' on a dry basis to form a protective film.

Example 3 The mixed resin used in Example 1 and an ethylene-vinyl acetate copolymer resin having a vinyl acetate content of 14% were coextruded to obtain blown films each having a thickness of 40 pm and 60 JLm, and used as a protective film.

Comparative Example 1 A film with a thickness of 50 gm was produced by an inflation method using only high-density polyethylene (Hisex 3300FJ manufactured by Mitsui Petrochemical Industries, Ltd.) and used as a film base material.

Further, an acrylic pressure-sensitive adhesive was coated on one side of this film base material to provide a pressure-sensitive adhesive layer of 8 g/m'' on a dry basis to form a protective film.

Comparative Example 2 65 parts of high-density polyethylene (Hizex 3300FJ manufactured by Mitsui Petrochemical Industries, Ltd.) and ethylene-α.
Olefin copolymerized low-crystalline elastomer (Mitsui Petrochemical Industries, Ltd. "Urtozex 2080CJ") 3
Pre-mix with 5 parts and use the inflation method to obtain a thickness of 35p.
-m film was produced and used as a film base material.

Further, an acrylic pressure-sensitive adhesive was coated on one side of this film base material to provide a pressure-sensitive adhesive layer of 8 g/m'' on a dry basis to form a protective film.

The sliding angles of the film substrates obtained in Examples 1 to 3 and Comparative Examples 1 to 2 were measured according to ASTM D-1894.

In addition, the protective films obtained in Examples 1 to 3 and Comparative Examples 1 to 2 were applied to an acrylic plate (polymethyl methacrylate plate) with a thickness of 3 cm and affixed by pressing with a roll, and then cut. Workability and depositability were tested.

The results are shown in Table 1.

Table 1 From Table 1, it can be seen that in Examples 1 to 3, the slipperiness was appropriate, the cutting workability was good, and there was no problem with the depositability.

On the other hand, in Comparative Example 1, it is slippery and has poor deposition properties. On the other hand, in Comparative Example 2, although the slipperiness was improved, it was suppressed a little too much, so there was a problem that it was difficult to align the synthetic resin plates during the deposition work.
Poor machinability.

Effects of the invention The protective film base material and protective film of the present invention are as follows:
While the excellent machinability of high-density polyethylene is maintained, the slipperiness is reduced to an appropriate level by the blended ethylene-α/olefin copolymer low crystallinity elastomer.

Therefore, even if the protective film of the present invention is attached to a synthetic resin plate and then piled up for storage or transportation, there will be no risk to workers or damage to the product due to unbalanced items.

In addition, the transparency of the film base material is not significantly reduced by incorporating the ethylene-α/olefin copolymerized low-crystalline elastomer, so the surface observation of the synthetic resin plate is not hindered, and the product value is not reduced.

Therefore, the protective film base material and protective film of the present invention are suitable for the purpose of surface protection of various synthetic resin boards, especially acrylic boards.

Claims (1)

[Claims] 1. 70-90% by weight of high-density polyethylene and ethylene-
α・Olefin copolymerized low crystalline elastomer 30-10
A film base material for protecting synthetic resin boards made by forming a film from a mixture of % by weight. 2. High-density polyethylene 70-90% by weight and ethylene-
α・Olefin copolymerized low crystalline elastomer 30-10
A film for protecting a synthetic resin board, which has a structure in which a pressure-sensitive or heat-sensitive adhesive layer is provided on one side of a film base material formed by forming a film from a blend of % by weight.