JP2002086639A5 - - Google Patents

Description

[0007]
[Problems to be solved by the invention]
An object of the present invention is to provide a transparent styrene-based resin anti-fog sheet having improved anti-fogging properties, especially practical low-fogging properties, while maintaining mold release properties during molding, that is, forming a styrene-based resin sheet. container, among others draw ratio of greater formed molded article (e.g., drawing ratio 0.3 or more moldings) excellent in improving its sustainability initial antifogging property level at low temperatures in, away from the mold of the molding machine An object of the present invention is to provide a styrene resin antifogging sheet having good moldability and a molded article having antifogging property.

That is, the present invention provides the following 1. ~ 6 . It has the feature of.
1. In a styrene resin antifogging sheet having one surface coated with an antifogging agent and the other surface coated with a release agent, the antifogging agent comprises the following components (A), (B) and (C) A styrene-based resin antifogging sheet, wherein the release agent contains the following (B).
(A) at least one fatty acid ester selected from sucrose fatty acid esters or polyglycerin fatty acid esters (B) ether-based multimer (C) polyvinyl alcohol

The antifogging agent composition comprising (A), (B) and (C) is preferably coated on one surface of the sheet in a total amount of 7 to 50 mg / m ² , more preferably 9 to 40 mg / m ^2. m ² , more preferably 12 to 35 mg / m ² . These coating amounts are particularly effective ranges from the viewpoint of imparting low-temperature antifogging property and high-temperature antifogging property, suppressing stickiness and blocking of the sheet, preventing whitening, and maintaining a good appearance of the sheet. Also, when using the sheet of the present invention as a packaging sheet for HiNaru form, since there is no stretching of the anti-fogging agent coating film by secondary molding, a sufficient effect can be obtained with a small amount of anti-fogging agent. Therefore, when used as a packaging sheet 7 mg / ^{m 2} or more 25 mg / ^{m 2} or less of coverage for HiNaru forms are preferred.

From the viewpoint of improving the uniformity of the coating film, in particular, after performing corona treatment on the sheet surface, the antifogging agent composition (A) + (B) + (C) or the release agent (B ) Or (B) + (D) . For example, when the composition is applied to a styrene resin sheet, the surface of the sheet is subjected to a corona treatment so that the contact angle with water becomes 80 to 30 °, and then the antifogging agent composition (A) is obtained by the above method or the like. + (B) + (C) or the release agent (B) or (B) + (D) composition is often preferred because the coating film becomes uniform. The upper limit of the contact angle with water is a value particularly effective for improving the uniformity of the coating film, and the lower limit of the contact angle is a value particularly effective for preventing blocking when the sheet is wound into a roll. It is. In particular, the surface on which the antifogging agent composition (A) + (B) + (C) is applied preferably has a contact angle with water of 50 to 30 ° from the viewpoint of imparting a high antifogging property. Preferably it is 35 to 50 °. The surface coated with the release agent (B) or (B) + (D) composition has a contact angle with water of 80 to 50 ° from the viewpoint of preventing blocking of the sheet and forming a uniform coating film. Is more preferable, and more preferably 75 to 50 °.