JP2008213308A - Surface protective film - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To control and prevent the occurrence of appearance abnormality phenomena by the use of surface protective film to be adhered to a molding before printing processing in manufacturing moldings of polycarbonate(PC) or polystyrene(PS), because the moldings are sensitive to and are easily eroded by organic solvents, often resulting in appearance abnormality phenomena on the surface of the moldings, e.g. cracking and whitening surface roughening, in e.g. screen printing. <P>SOLUTION: The surface protective film is a laminate having a substrate layer and an adhesive layer and is produced with a T- or circle-die multi-layer coextrusion film-forming apparatus having a single production process, and the adhesive resin in the adhesive layer contains at least one breeding ingredients selected from 12C or higher fatty acid compounds, derivatives of the fatty acid compounds, e.g. their salts, amides and esters, and higher alcohols. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

A surface protective film that is attached to a molded product (plate, film) such as a synthetic resin to protect the surface of the molded product from scratches, dirt, etc., and further molded using an organic solvent such as screen printing A functional film that also has the effect of preventing poor surface appearance.

Conventional surface protection films are mostly attached to the surface of molded articles that are adherends, and then peeled off and discarded every time the molded articles are processed. And unnecessary components that cause adverse effects are eliminated as much as possible and are not contained.
As a result, there is no transfer deposit from the surface protective film even if it is affixed to a molded product of polycarbonate (PC) or polystyrene (PS). On the surface of sensitive molded products, cracks, whitening, and other appearance defects are likely to occur.

Conventional surface protection films are ineffective when processing into PC or PS molded products that are sensitive to organic solvents, as described in the above "Background Technology", and are formed when processing using organic solvents such as screen printing is performed. Appearance defects easily occur on the surface of products.
Prevent and resolve the appearance defect phenomenon from the surface protective film surface applied to the molded product.

Blending the bleeding component, which was strictly prohibited with conventional surface protection films, into the adhesive layer of the surface protection film, which is a laminate, and transferring (adhering) it to the surface of the adherend. Thus, the surface of a molded product sensitive to an organic solvent is coated and the occurrence of the “appearance defect” phenomenon is suppressed and prevented.
That is, the gist of the present invention is as follows.
-A laminate consisting of a base layer and an adhesive layer obtained from a multi-layer coextrusion film-forming apparatus of T-die or round die, which has only one production process, and the following bleeding components in the adhesive layer: At least one kind is blended to obtain a surface protective film.
(Bleeding component of blending): Higher fatty acid compound having 12 or more carbon atoms, or derivatives thereof (salts, amides, esters, etc.) or higher alcohol (blending amount): 50 ppm or more with respect to the resin amount of the adhesive layer

When the surface protective film of the present invention is affixed to a molded product sensitive to an organic solvent (such as a PC board), the appearance of the molded product after processing, such as screen printing, is "whitening skin rough and other abnormal phenomena. It was confirmed that it was “good” with no occurrence.
As a result, it can be greatly expected that the quality of printed products will be improved.

The surface protective film of the present invention is a laminate comprising a base material layer (A) and an adhesive layer (B) described below, and a bleeding (leaching) component (1) is blended in the adhesive layer to produce a production process. Is obtained directly from a multi-layer coextrusion film forming apparatus of a T die or a round die having only one process.
Laminate (A): formed from an olefin polymer having an olefin of 70% or more (B): formed from a thermoplastic adhesive resin Compound (1): a higher fatty acid compound having 12 or more carbon atoms, or a derivative thereof Salt, amides, esters, etc.) or higher alcohol content: 50 ppm or more based on the resin amount of the adhesive layer, the present invention will be described in detail. It is not limited to examples.

A laminate (surface protective film) having the following constitution obtained by a T-die coextrusion film forming apparatus was stuck on a polycarbonate (PC) plate having a thickness of 0.5 mm and left indoors for 2 days.
After that, the surface protective film is peeled off from the PC board, a predetermined ink with a coating thickness of 60 μm is applied, and then naturally dried, and the surface state of the PC board is visually observed. The results obtained are shown in Table-1.
-Structure of laminate body layer: Propylene polymer PP (MFR 7.0, density 0.90)
Adhesive layer: Ethylene vinyl acetate copolymer resin EVA (MFR 2.0, density 0.92)
Blending agent: erucic acid amide (blending amount: 500 ppm)
-Application printing ink Teikoku ink (13-000) and solvent (G004)
Mixing ratio [medium: solvent = 100: 30]

The same as Example 1 except that only the resin for the adhesive layer was changed to the following.
Adhesive layer resin: [1: 1] mixture of hydrogenated styrene butadiene rubber HSBR and PP
[Comparative Example 1]

In Example 1, except that “no blending” was used for the bleeding agent in the adhesive layer, all other layers were subjected to printing evaluation by obtaining a laminate by the same method.
[Comparative Example 2]

In Example 2, except for “no blending” of the bleeding agent and the AB agent in the adhesive layer, all other layers were obtained by the same method, and printing evaluation was performed.

Claims (2)

A laminate comprising a base layer (A) and an adhesive layer (B) obtained from a multi-layer coextrusion film forming apparatus of a T die or a round die, wherein the bleeding component of the following (1) is at least in the adhesive layer (B) One or more types of surface protective film (A): base layer formed from an olefin polymer having an olefin of 70% or more (B): adhesive layer (1) formed from a thermoplastic adhesive resin: Higher fatty acid compounds having 12 or more carbon atoms, or derivatives thereof (salts, amides, esters, etc.) or higher alcohol content: 50 ppm or more The surface protective film according to claim 1, which is attached to a molded article (plate, film, etc.) of polycarbonate (PC) or polystyrene (PS) and peeled off before processing using an organic solvent such as screen printing.