JPS6176535A - Composite treatment of surface - Google Patents

Abstract

PURPOSE:To carry out the activation treatment for improving the adhesivity of the surface of a polyolefin resin molded article, by contacting the surface with a mixture of a halogenated hydrocarbon compound and an aromatic hydrocarbon compound, and irradiating with ultraviolet radiation having short wavelength, thereby inducing the chemical reaction at the surface. CONSTITUTION:The surface of a molded article of a polyolefin such as polyethylene, polypropylene, etc. is brought into contact with a mixture of a halogenated hydrocarbon compound and an aromatic hydrocarbon compound. 5min after removing the mixture, the surface is irradiated with ultraviolet radiation having the principal wavelength of <=2,550Angstrom . The activation treatment of the surface of the molded article for improving the adhesivity in the painting, printing or bonding operation can be carried out by this process.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a surface treatment method using short wavelength ultraviolet light.

Posoolefine resin moldings such as polyethylene and polypropylene have low activity on their surfaces, so paints, printing inks, adhesives, etc. are difficult to adhere to. Therefore, in order to perform painting, printing, or adhesion on the surface of a polyolefin resin molded product, it is necessary to activate the surface of the molded product.

For this purpose, chromic acid mixture treatment, flame treatment, corona discharge treatment, plasma treatment, etc. have been conventionally performed. However, these methods have major drawbacks. Chromic acid mixture treatment has not been carried out due to pollution problems, and flame treatment tends to melt the surface of the molded product. Corona discharge treatment can only treat extremely thin objects. Plasma treatment requires high equipment costs.

Therefore, the development of new treatment methods is eagerly awaited.

In order to solve the above-mentioned problems encountered in surface treatment of polyolefin resin moldings, while conducting research, the present inventors applied polyolefin resin moldings to a mixture of a halogenated hydrocarbon compound and an aromatic hydrocarbon compound. After contacting the surface of the molded body, irradiate it with short-wavelength ultraviolet light whose main wavelength is ultraviolet light with a wavelength of 2580 cm or less. The present invention was developed based on the discovery that the adhesive strongly adheres to the adhesive.

The polyolefin resin used in the present invention refers to a resin whose main component is polyolefin, and includes polyethylene, polypropylene, and the like. In addition, the light used for processing has a wavelength of 25
Ultraviolet rays of 50 μm or less are preferred. The stronger the intensity of the ultraviolet rays, the better.

Next, the present invention will be explained in detail by way of examples.

Example 1 Low density polyethylene plate and polypropylene plate (3c
m x 6 cm x 2 mm) was prepared and brought into contact with a mixture of a halogenated hydrocarbon compound and an aromatic hydrocarbon compound,
Short-wavelength ultraviolet rays were irradiated after 5 minutes had passed after the contact was broken, and 24 hours after irradiation, acrylic resin paint was sprayed with a spray gun to perform painting. After drying in the air for 48 hours, the surface of the coating was cross-cut into 1 mm squares, cellophane tape was applied to the cross-cuts, and a peel test was conducted. The results are summarized in the table below.

table

Claims (1)

[Claims] (1) After bringing a mixture of a halogenated hydrocarbon compound and an aromatic hydrocarbon compound into contact with the surface of a polyolefin resin molding, it is irradiated with light whose main wavelength is ultraviolet rays with a wavelength of 2550 Å or less to cause chemical changes on the surface. A processing method characterized by causing