JPS6012229B2 - High frequency processing surface protection sheet - Google Patents

Description

[Detailed description of the invention] The present invention relates to a high frequency processed surface protection sheet.

Fibers, films, woven fabrics, knitted fabrics, non-woven fabrics, foam sheets, synthetic leather containing substances that are easily softened and melted by high frequency excitation, such as vinyl chloride, vinyl chloride/vinyl acetate copolymerization, ethylene/vinyl acetate copolymerization, vinylidene chloride, etc. High frequencies are used in processing such as molding, bonding molding, sewing and joining, etc., and methods are being explored to process the workpiece by softening or melting it from the inside. In this way, most of the processing using high frequency is carried out by using a pair of molds as electrodes 5 and 6, and applying pressure to the workpiece 8 between them while generating high frequency waves. In order to prevent cracks on the surface of the electrode mold and adhesion of the molten workpiece to the mold, a sheet 1 made of a high-frequency non- or scale-excited polymer material with a relatively high melting point is placed between the electrode mold and the workpiece. A method of intervening between the two is being explored. A polyester film is used as such a high-frequency processing surface protection sheet 1, but the conventionally used protection sheet is easily torn, especially at the contour corners of the mold 5 and at the contact points with the uneven edges 7, and has a poor durability. It was something lacking.

The present invention aims to solve this problem and provide a high-frequency processed surface protection sheet with excellent durability, and the protection sheet 1 is a flexible sheet laminated with three or more layers,
The gist of this is that the two layers 2 and 3 on the front and back sides are formed of a high-frequency non- or chick-excited polymer material with a relatively high melting point.

The material forming the front and back two layers 2 and 3 is polyester,
A material such as polyamide (nylon) that enables adhesion to the intermediate layer 4, has a high melting point and a trough property that does not melt due to the residual heat of the molds 5 and 6, and is not easily excited by high frequencies is used.

At least one intermediate layer 4 is sufficient, and the protective sheet as a whole can have a multilayer structure of three or more layers.

By creating a multilayer structure like this, even if the thickness of the protective sheet is the same as that of a conventional protective sheet, partial tearing caused by the mold of the protective sheet can be prevented.
In the process of tearing and fracture due to stress acting in the front and back directions of the protective sheet due to the pressure applied by the electrode molds 5 and 6, a submergence phenomenon occurs between the layers 2 and 4, 4 and 3 without crystal rotation, and the adhesion of each layer. This is thought to be because stress is dispersed along the surfaces 21 and 31.

This is because the intermediate layer 4 is made of natural rubber, styrene-butadiene rubber, butadiene-acrylonitrile rubber, nitrile rubber,
It is made of a tacky resin composition composed of chloroprene rubber or the like as a rubber elastic body and rodiso, rodisoester, kumaroso resin, terbene resin, and hydrocarbon resin as tackifiers, thereby forming two layers on the front and back. This is because when the IJester films 2 and 3 are bonded together to form a three-layer structure consisting of the polyester surface layer 2, the adhesive intermediate layer 4, and the polyester back layer 3, a remarkable effect of preventing tearing occurs. In addition to these adhesives, it is desirable to have at least one layer having viscoelasticity such as nitrile comb or ethylene vinyl acetate copolymer resin interposed in the intermediate layer.
It may function to bond the front and back two layers over the entire surface or at points. Such an intermediate layer is applied by applying the doctor method, roll transfer method, curtain flow method, isothermal method, or dry lamination method to the polyester film that will become one of the front and back layers, and then overlaps the polyester film that will become the other layer of either the front or back. They can be laminated by combining them together, or they can be laminated by transferring an adhesive layer that has been laminated in advance onto a release sheet, and the number of laminated intermediate layers and the lamination method are not limited. However, the degree of excitation heating of the workpiece 8 during high-frequency machining depends on the distance between the electrode molds, and the sharpness and delicacy of the contour of the mold applied to the workpiece depend on the thickness of the protective sheet. The thickness of the protective sheet should be set to 3.
00r or less, preferably 100r or less, and for this purpose it is not appropriate to make the intermediate layer a porous layer by using a reinforcing material such as fiber woven or pulp, and in the present invention, it is not appropriate to make the intermediate layer a porous layer by using a reinforcing material such as fiber wafer or pulp. This structure prevents tearing and eliminates the need for reinforcing fibers.

In this way, since the protective sheet can be made extremely thin while preventing the occurrence of tears without using reinforcing fibers, the high-frequency processed surface protective sheet according to the present invention is transparent or semi-transparent, and the protective sheet is protected by the protective sheet. Processing work can be done while checking the high-frequency irradiation position of the workpiece by seeing through it, and the protective sheet is highly flexible and flexible, making it possible to mold clear and delicate mold patterns. arise.

[Brief explanation of the drawing]

FIG. 1 is a partial cross-sectional view of a high-frequency processing apparatus, and FIG. 2 is a cross-sectional view of a high-frequency processing surface protection sheet according to the present invention. DESCRIPTION OF SYMBOLS 1... High-frequency processed surface protection sheet, 2... Surface layer, 3... Back layer, 4... Intermediate layer, 5, 6...
... Mold (electrode), 7 ... Mold contour angle (uneven ridge), 8 ... Workpiece. Fin' diagram 2

Claims (1)

[Scope of Claims] 1. High-frequency processing of a flexible sheet laminated with three or more layers, the front and back two layers of which are formed of a relatively high-melting point, high-frequency non- or difficult-to-excite polymeric material. Face protection sheet. 2. In claim 1, the flexible sheet laminated with three or more layers is transparent or translucent, and does not have a porous layer as an intermediate layer. 3. In claim 2, the thickness of the flexible sheet laminated with three or more layers is 300μ or less. 4. In claim 3, the flexible sheet has at least one viscoelastic layer as an intermediate layer of three or more laminated flexible sheets. 5. In claim 4, the polymeric material on the front and back two layers of the flexible sheet laminated in three or more layers is a polyester or polyamide-based material.