JPS63264638A - Surface protection of plastic sheet - Google Patents

Abstract

PURPOSE:To perform the surface protection of the title sheet so that it may retain its antistatic performance even after peeling a masking paper, by laminating a masking paper having an adhesive layer containing a specified antistatic agent to the surface of the plastic sheet. CONSTITUTION:100pts.wt. adhesive (a) (e.g., an aqueous solution of a partial saponificate of polyvinyl acetate as a water-soluble paste) is mixed with 5-30pts.wt. mixture (b) (weight ratio of 100:5-20, preferably, about 10:1) of a nonionic antistatic agent (i) with an anionic, cationic or amphoteric antistatic agent (ii), and the obtained mixture is applied to a paper base (e.g., unbleached unglazed kraft paper of a basis weight of 20-150g/m<2>) to a thickness of 2-20mum to obtain a masking paper (B) for surface protection. Component B is laminated to a plastic sheet (A).

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for protecting the surface of a plastic plate by pasting masking paper for surface protection on the plastic plate. The present invention relates to a method for protecting the surface of a plastic plate, which allows the stuck plastic plate to maintain its antistatic ability even after the surface protection masking paper is peeled off and removed.

Conventional technology and the problem that Ming aims to solve Conventionally, plastic plates made of synthetic resins such as acrylic resin, polyester, polyvinyl chloride, and polycarbonate have been subject to problems such as surface damage during transportation, cutting, bending, etc. To prevent scratches on the plastic plate, masking paper coated with a water-soluble adhesive such as polyvinyl alcohol is pasted on one side of the paper base material to protect the surface of the plastic plate.

However, the above-mentioned masking paper for surface protection is usually not treated with antistatic treatment, and therefore, when the masking paper for surface protection is peeled off from the plastic plate, static electricity is generated on the plastic plate, resulting in cutting, etc. During processing, they often adsorb cutting chips and surrounding dust, often damaging and contaminating the surface of the plastic plate.

For this reason, it has been proposed to add surfactants to adhesives such as water-soluble glue when manufacturing masking paper (
(Japanese Unexamined Patent Publication No. 58-191777), it is known that this provides an antistatic effect to masking paper, but the conventional method of protecting the surface of a plastic plate using this type of masking paper is The antistatic effect on the plastic plate after peeling and removal is weak, and it still adsorbs cutting chips, dust, etc. during processing such as cutting, and the plastic plate may be damaged or contaminated by these adsorbed cutting chips, dust, etc. However, after the masking paper was peeled off, the surface of the plastic plate was not sufficiently protected.

The present invention was made in view of the above circumstances, and is a method for protecting the surface of a plastic plate using a masking paper for surface protection, which is capable of imparting and maintaining antistatic properties to the plastic plate even after the masking paper is peeled off and removed. The purpose is to provide

In order to achieve the above object, the inventors of the present invention have made intensive studies and found that a specific composition, that is, a nonionic adhesive layer, is used in the adhesive layer attached to the plastic plate of the masking paper. When an antistatic agent consisting of an antistatic agent and one or more selected from anionic antistatic agents, cationic antistatic agents, and amphoteric ionic antistatic agents is mixed, the adhesive layer of the masking paper causes the masking paper to become plastic. It protects the surface of the plastic plate by attaching it to the board, and at least part of the antistatic agent contained in the adhesive layer transfers and remains on the surface of the plastic board when the masking paper is peeled off and removed. , It is possible to impart and maintain antistatic ability to the plastic plate even after the masking paper is peeled off and removed, and in addition, in this way, a nonionic antistatic agent and a cationic, anionic, or amphoteric antistatic agent are used in combination. The inventors have discovered that by doing so, the amount of antistatic agent added to the adhesive can be reduced as much as possible, and that a relatively small amount of antistatic agent can effectively prevent static electricity on a plastic plate, and have developed the present invention. It has been completed.

Therefore, the present invention provides a method for protecting the surface of a plastic plate by attaching an adhesive layer of masking paper for surface protection to the surface of the plastic plate. A nonionic antistatic agent and an anionic, cationic, or amphoteric ionic antistatic agent are combined as an inhibitor, and the adhesive layer of this masking paper is attached to the plastic plate to protect the surface of the plastic plate. In addition, when the masking paper is peeled off and removed, at least a portion of the antistatic agent contained in the adhesive layer is transferred and remains on the surface of the plastic plate, thereby preventing the plastic plate from being charged. The present invention provides a method for protecting the surface of a plastic plate.

It has already been proposed to incorporate an antistatic agent into the adhesive layer in a similar plastic surface protection method;
A relatively large amount of antistatic agent of up to 300 parts by weight was required (Japanese Patent Application No. 60-297789). In contrast,
The present invention uses an antistatic agent having a specific composition as described above, and as described below, 5 parts by weight of the adhesive is used.
A sufficient antistatic effect can be obtained by using a relatively small amount of antistatic agent, such as 30 parts by weight, and antistatic effect can be achieved economically.

Hereinafter, the method for protecting the surface of a plastic plate according to the present invention will be explained in more detail.

The masking paper for surface protection used in the method for protecting the surface of a plastic plate of the present invention has an adhesive layer formed on one side of a paper base material.

Here, the paper base material is unbleached double-page kraft paper or single-gloss kraft paper with a weight of about 20 to 150 g/rrr.

Stretchable kraft paper, semi-bleached or bleached kraft paper, crepe paper, high-quality paper, etc. can be used, but the weight per square meter is 30 to 50 g.
It is most preferable to use single-gloss kraft paper of about /rd from the viewpoint of performance as a masking paper such as flexibility and smoothness, and from the viewpoint of price.

In addition, as adhesives forming the adhesive layer, partially saponified polyvinyl acetate and polyvinyl ether are used.

Vinyl resin adhesives such as polyvinylpyrrolidone, methylcellulose, hydroxymethylcellulose.

Cellulose adhesives such as carboxymethyl cellulose,
Natural water-soluble adhesives such as starch and dextrin, protein-based adhesives such as glue, gelatin, and casein can be used, but among them, water-soluble glues such as saponified polyvinyl acetate, starch, dextrin, and carboxymethyl cellulose can be used. This method is preferable because the masking paper for surface protection is adhered to the surface of the plastic plate and the masking paper has excellent removability after being peeled off, and the surface properties of the plastic plate are excellent.

Furthermore, as the antistatic agent blended into the adhesive layer, a nonionic antistatic agent and one or more types selected from anionic, cationic, and nonionic antistatic agents are used in combination.

Here, the blending ratio of both is not particularly limited, but 5 to 20 parts by weight, especially 7 to 15 parts by weight of anionic, cationic, or nonionic antistatic agent is added to 100 parts by weight of nonionic antistatic agent. It is preferable to use the antistatic agent in combination in the same proportion, and by using a nonionic agent as the main agent in this way, it is possible to reliably prevent static electricity on the plastic plate and to reduce the amount of antistatic agent used as much as possible. . Among anionic, cationic, and nonionic antistatic agents, it is preferable to use anionic antistatic agents in terms of antistatic effect and reduction in the amount of antistatic agent used. When the blending ratio is about 10=1 by weight, excellent antistatic properties can be obtained.

Specifically, the anionic antistatic agent has 3 carbon atoms.
Phosphates such as pentaalkyl tripolyphosphate and hexaalkyl tetrapolyphosphate having ~5 alkyl groups.

One or more types of ester total salts such as dialkyl phosphate metal salts, alkylmethylammonium chloride as a cationic antistatic agent, N-cyclohexylamine butyrate or phosphate, monoethanolamine butyrate, etc. Butyrate or phosphates such as phosphate
species or two or more nonionic antistatic agents such as ethylene oxide adducts such as alkylphenol ethylene oxide adducts, aliphatic esters of polyhydric alcohols such as glycerol, pentaerythritol, and sorbitol;
1 such as ester salts such as alkyl phosphate ester salts
Examples of the amphoteric antistatic agent or two or more amphoteric antistatic agents include betaine antistatic agents such as stearyl dimethyl betaine.

In addition, there is no particular limitation on the amount of antistatic agent added to the adhesive, and good antistatic properties can be achieved by providing a surface resistance value of about 10" to 1012 Ω/Cm2 to the surface of the plastic plate to be adhered after the masking paper has been removed. Although the masking paper has the above-mentioned properties, even after the masking paper is peeled off from the surface of the plastic plate, the above-mentioned surface resistance value is given to the adhered surface, and the masking paper can be attached to a plastic plate made of synthetic resin etc. using an adhesive layer. In order to reliably attach the masking paper and protect the plastic plate without interfering with the process, a total of 5 to 30 parts by weight, especially 7 to 25 parts by weight of both antistatic agents should be added to 100 parts by weight of the adhesive. Since the antistatic agent of the present invention has a high antistatic effect, a sufficient effect can be obtained with a relatively small amount.In this case, the antistatic agent may be added to the adhesive. If the blending amount is less than 3 parts by weight, the antistatic agent will be sufficiently transferred to the surface to be adhered after the masking paper is peeled off, and the antistatic agent will not remain, and the surface resistance value will be 1013 Ω/d or more, so the antistatic performance will be sufficient. In addition, if it exceeds 40 parts by weight, the surface resistance value will be less than 10 gΩ/■2.
Although the antistatic performance is sufficient, on the other hand, the transferred antistatic agent may cause problems such as adsorption of dust or a strong feeling of adhesive residue, which are both undesirable. In addition, as mentioned above, when a nonionic antistatic agent and an anionic antistatic agent are used together, the total blending amount of both antistatic agents can be 20 parts by weight or less with respect to 100 parts by weight of the adhesive, especially 10 parts by weight. ; When used in combination at a weight ratio of 1, an extremely high antistatic effect can be obtained by setting the total blending amount to 15 to 20 parts by weight.

In addition, other components such as antistatic agents other than those used in combination with the above may be added to the adhesive layer as necessary. In addition, the thickness of the adhesive layer is not necessarily limited, but 2
~201m, particularly preferably 4~101m.

The method for protecting the surface of a plastic plate of the present invention uses the above-mentioned masking paper for surface protection, and by attaching and peeling this to the plastic plate, when the masking paper is peeled off and removed, the adhesive layer contained in the masking paper is removed. At least a part of the antistatic agent is transferred and remains on the surface of the plastic plate,
Even after the masking paper is peeled off and removed, the antistatic ability is imparted to the plastic plate and lasts for a long time, but there are no special restrictions on how to handle the masking paper, such as peeling it off or removing it. can be handled.

Masu J1 Summer 1 Loss As explained above, the present invention incorporates an antistatic agent of a specific composition that exhibits an antistatic effect in a relatively small amount into the adhesive layer that is attached to the plastic plate of the masking paper for surface protection. The adhesive layer of this masking paper is applied to a plastic plate to protect the surface of the plastic plate, and at least part of the antistatic agent contained in the adhesive layer is then removed when peeling and removing the masking paper. By adhering and remaining on the surface of the plastic plate, the plastic plate is prevented from being charged after the masking paper is peeled off and removed, and cutting chips, dust, etc. are not adsorbed to the plastic plate during secondary processing. It is suitable for protecting various synthetic resin boards, decorative boards, etc.

EXAMPLES Hereinafter, the present invention will be specifically explained with reference to examples, but the present invention is not limited to the following examples.

[Example, comparative example]

As a paper base, a partially saponified polyvinyl acetate (polymerization degree 1700, saponification degree 88.0
%), 1.5 parts by weight of a nonionic antistatic agent (Emulgen 910 manufactured by Kao Atlas Co., Ltd.) and 1.5 parts by weight of an anionic antistatic agent (Kao Atlas Co., Ltd.) as an antistatic agent. Co., Ltd.'jl! Electron Stripper K) 0.15 parts by weight is mixed with about 6
．． A masking paper for surface protection was manufactured by coating with a roll coater so that the coating amount was 0 g/rrr.

This masking paper was pasted on a 2.0 m thick acrylic board while spraying steam, and after being left at room temperature for 7 days, the masking paper was peeled off and removed, and the surface resistance value of the acrylic board was measured. The resistance value is 8X10”Ω/
ail, and even if it was left for a while, it did not attract dust, and even when this acrylic plate was cut, it did not attract cutting waste.

On the other hand, for comparison, two types of masking paper were produced in the same manner as the above masking paper, except that only the nonionic antistatic agent or only the anionic antistatic agent was used. The surface resistance value was measured, and the dust and cutting debris adsorption properties were evaluated.

As a result, the surface resistance value of the comparative example after peeling off the masking paper was 3XIO"Ω/d for the one with only nonionic antistatic agent
5 x 10 for those containing only anionic antistatic agent
"Ω/a was about 12, and adsorption of dust, cuttings, etc. was observed in both cases.

From the above results, when the surface of a plastic plate is protected by the method of the present invention, the surface protection performance is excellent without attracting dust or cutting chips even after the masking paper is peeled off and removed. In the comparison method for protecting the surface of a plastic plate, dust and cutting debris were adsorbed after the masking paper was peeled off and removed.
It was found that the surface protection performance after removal was poor.

Applicant Fujimori Kogyo Co., Ltd. Agent Patent attorney Takashi Kojima Procedural amendment (voluntary) April 20, 1988 Commissioner of the Japan Patent Office Kunio Ogawa 1, Indication of case Patent Application No. 99068 of 1988 2. Name of the invention Method for protecting the surface of plastic plates 3. Person making the amendment Relationship to the case Patent applicant address 1-4-16 Nihonbashi Bakuro-cho, Chuo-ku, Tokyo
Name: Fujimori Kogyo Co., Ltd. Representative: Toshihiko Fujimori 4, Agent: 104 Address: 5th floor, Dapa Create Building, 3-11-14 Ginza, Chuo-ku, Tokyo Telephone: (545) 64546 Contents of amendment (1) Insert "1 part" after "vinyl" on page 7, line 18 of the specification.

(2) Insert "protection" after "surface" in the second line of page 8.

(3) On page 8, line 5, the word ``non'' is corrected to ``bisexual.''

(4) In the 8th line of page 8, the word ``non'' is corrected to ``bisexual.''

(5) On page 8, line 14, the word ``non'' is corrected to ``bisexual.''

(6) On page 9, line 10, “noni” is replaced with “noni”.
I am corrected.

that's all

Claims (1)

[Claims] 1. In a method for protecting the surface of a plastic plate by applying an adhesive layer of masking paper for surface protection to the surface of the plastic plate, the adhesive layer of masking paper applied to the plastic plate A nonionic antistatic agent and an anionic, cationic, or amphoteric ionic antistatic agent are mixed as antistatic agents in the masking paper, and the adhesive layer of this masking paper is attached to the plastic plate, so that the surface of the plastic plate is In addition to protecting the plastic plate, when the masking paper is peeled off, at least a portion of the antistatic agent contained in the adhesive layer is transferred and remains on the surface of the plastic plate, thereby preventing the plastic plate from becoming static. A distinctive method for protecting the surface of plastic plates. 2. The surface protection method according to claim 1, wherein the adhesive is a water-soluble glue. 3. The weight ratio of the nonionic antistatic agent to the anionic, cationic, or amphoteric antistatic agent is 100.
:5-20. The surface protection method according to claim 1 or 2. 4. The surface protection method according to any one of claims 1 to 3, wherein the total amount of the antistatic agent is 5 to 30 parts by weight based on 100 parts by weight of the adhesive.