JPS5845991B2 - Rikeiyo sheet - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a sheet, and more particularly to a release sheet having appropriate surface activity.

Conventionally, various types of release sheets have been widely used.

However, some of these products are too heavy to peel off, and others are too light. It has been desired to produce a sheet with a mold releasability of .

As a result of intensive studies regarding these points, the present inventor has determined that the surface of the base sheet is made of vinyl fluoride as a release sheet that has appropriate release performance and also has performance that makes the release surface of the molded product suitable for post-processing such as printing. A fluorine-containing copolymer whose main component is hexafluoropropylene and a polymer or copolymer that does not contain fluorine atoms in the molecule is added to 1 part of the fluorine-containing copolymer.
．． The inventors have discovered that a sheet coated with a mixture containing 0.05 to 20 parts is preferable and have arrived at the present invention.

Component 1 used in the coating of the present invention is a copolymer whose main components are vinyl fluoride and hexafluoropropylene.

The vinyl fluoride component in the copolymer is 95 to 60 mol%, preferably 80 to 75 mol%.

Further, the intrinsic viscosity of the copolymer is in the range of 0.1 to 1.0, preferably 0.2 to 0.7.

In addition, other copolymerizable components may be included within a range that does not impair the performance of the copolymer.

Such components include vinyl acetate, styrene, vinyl chloride, and other compounds generally called vinyl compounds, methyl methacrylate, acrylic acid, other acrylic acids, methacrylic acids, and esters thereof.

The amount of these third components added is generally 10% or less by weight.

In addition, the resin used in combination with this fluororesin does not contain fluorine atoms in its structure, and may be a homopolymer or a copolymer, and may be a thermoplastic resin or a thermosetting resin.In general, the transparency and uniformity of the coating From this point of view, acrylic resins such as polyacrylic acid-esters and certain epoxy resins, which have relatively high compatibility with the fluororesin, are preferable.

Other examples include copolymers of vinyl acetate and vinyl chloride, polyester resins, polystyrene, and silicone resins.

However, although silicone resin exhibits sufficient mold release performance, it may cause problems during post-processing such as printing, and this point must be kept in mind.

The mixing ratio of the same components is 0.05 to 20 parts of the non-fluorinated polymer to 1 part of the fluorinated copolymer, and this ratio is 0.05 to 20 parts.
If the amount is less than 0.5 parts, problems may arise in processing the molding surface in subsequent steps, and if it is extremely large, such as 20 parts or more, the mold release performance may deteriorate.

In the present invention, the base sheet includes a film made of a synthetic resin such as polyethylene terephthalate or polyvinyl chloride, paper, or a laminated paper obtained by laminating a thin film of polyolefin resin such as polyethylene on paper.

To create the mold release coating of the present invention on these substrates, it is common to first dissolve a mixture of a fluororesin and a non-fluorine resin in a predetermined proportion in a common solvent for both, and then apply and dry. .

For example, the mixture of the fluororesin and acrylic ester resin of the present invention is dissolved in a mixed solvent consisting of ethyl acetate, methyl ethyl ketone, and diacetone alcohol, and coated using a bar coater or doctor knife in the laboratory, or a gravure coater on a large scale. Apply and dry using a machine.

However, it is also possible to apply a mixture of the fluororesin emulsion of the invention and the acrylic resin emulsion.

Examples are shown below.

※※Example: Three types of vinyl fluoride and hexafluorofluoropylene copolymers were blended with various non-fluorinated polymers, and each of them was mixed in a mixed solvent of methyl ethyl ketone, methyl isobutyl ketone: acetic acid cersolupylene 1:2:1. It was dissolved so that the total amount was a 3% solution.

This solution was applied to a polyethylene terephthalate film (thickness: 38 μm) using a heat coater, dried at room temperature, and heated vigorously at 130° C. for 2 minutes to form a coating layer on the film.

And Shell Chemical's Epicure 828/Epicure Z
Table 1 shows the mold release performance when the epoxy resin was cured on the coating at 180° C. for 4 hours.

Claims (1)

[Claims] 1. The surface of the basic sheet is coated with a fluorine-containing copolymer mainly composed of vinyl fluoride and hexafluoropropylene, and 0.05 to 20 parts by weight of the fluorine-containing copolymer per 1 part by weight of the fluorine-containing copolymer. 1. A release sheet characterized by being coated with a mixture of a polymer or a copolymer containing no fluorine atoms.