JPH0357144B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a modified synthetic resin molded article whose surface is subjected to pulse irradiation treatment with an excimer laser, and particularly aims to provide a polyethylene terephthalate or polysulfone molded article with significantly improved adhesive properties. Synthetic resin molded products, such as films and sheets, may be used as they are in the molded state without any printing, painting, or other secondary processing. It is often used by laminating or bonding composites with inorganic materials such as metals and glass. However, in these cases, the adhesiveness of the surface of the synthetic resin molded product is poor, resulting in poor adhesion of printing ink, and the quality performance of the composite product is impaired, so there is a strong desire to improve the adhesion. Conventional methods for improving the adhesion of synthetic resin molded products include wet treatments such as acid/alkali treatment, primer coating, and corona treatment, but wet treatment methods such as acid/alkali treatment require the use of powerful chemicals and It is not welcomed because it is a liquid treatment, and primer treatment has the disadvantage of adding extra steps of primer application and drying. Furthermore, corona treatment has shortcomings in that the durability of the effect is poor, and the adhesiveness, printability, etc. imparted to it disappear over time, and the modification effect itself is low. On the other hand, it is known that continuous irradiation treatment of the surface of synthetic resin molded products with short-wavelength ultraviolet light improves adhesion (industrial materials,
Vol.29, No.1, p124), in order to achieve the desired improvement in adhesion using this method, it takes 10 to 30 minutes for the irradiation process, and in order to shorten this process time, it is necessary to This poses a problem in practical application because it requires a large size and high output, and is difficult to adopt from an industrial standpoint, where a sufficient effect must be obtained in a processing time of 10 seconds or less. Another reason why adhesion cannot be improved by using conventional discharge tubes or lamp-like ultraviolet light sources is that, for example, low-pressure mercury lamp light sources contain various bright lines (185, 254, 313, 365 nm). 185n
All ultraviolet light other than m and 254 nm does not cause the surface modification reaction to improve the adhesion of polyethylene terephthalate or polysulfone molded products, which is the object of the present invention, and has the opposite effect, in that ultraviolet light deteriorates and promotes adhesive deterioration. This is thought to be due to the fact that some substances exhibit effects. Recently, excimer laser oscillation has been confirmed, which utilizes an excimer created by the bond between an excited state atom (molecule) and a ground state atom (molecule), and is attracting attention as a new photochemical reaction light source. The present inventors particularly focused on the monochromaticity (single wavelength light) and high light intensity of lasers, which cannot be obtained with conventional discharge tubes and lamp light sources, and used these characteristics to create synthetic resin molded products with the aim of improving adhesive properties. As a result of considering the use of polyethylene terephthalate or polysulfone molded products in surface modification reactions, we found that by short-time pulse irradiation treatment of the surface of polyethylene terephthalate or polysulfone molded products with an excimer laser in the wavelength range of 95 to 200 nm, we were able to significantly improve the adhesion of the surface layer of the molded products. The present invention was completed by discovering that an extremely thin modified layer that can be improved can be reliably formed without impairing the inherent mechanical properties of the molded article. The present invention will be explained in detail below. The polyethylene terephthalate or polysulfone used in the molded article of the present invention may have any molecular structure, molecular weight, etc., such as homopolymers, copolymers, block copolymers, graft copolymers, and mixtures of different synthetic resins. In obtaining molded products from these synthetic resins,
Various compounding agents, additives, or processing aids may be added, such as plasticizers, stabilizers, lubricants, fillers, extenders, pigments, dyes, heat resistance improvers, flame retardants, and antiseptics. Even if an oxidizing agent, a weathering agent, a light absorbing agent, a surfactant, a crosslinking agent, a cloud-proofing agent, a moisture-proofing agent, an elasticity improver, etc. are added and blended, the effects of the present invention are not affected. The present invention targets films, sheets, and other molded products of various shapes, including the casting method,
It is manufactured by conventionally known molding methods such as melt extrusion, calendering, stretching, and compression. The surface of the molded product obtained in this way is
Pulse irradiation treatment is performed using an excimer laser in the 200nm wavelength range, and examples of this laser include Ar2 (126nm), Kr2 (146nm), and Xe2 (172nm).
m), ArCl (175 nm), ArF (193 nm), etc., and it is also possible to use harmonics of these waves, and it is also possible to use them by performing wavelength conversion with a Raman shifter. Laser beams with wavelengths exceeding 200 nm only have the effect of photodegrading and thermally deteriorating the molded product, and although laser beams with wavelengths of 95 nm or less are not yet known, they are presumed to be quite large and expensive, and therefore the present invention It is not suitable for the purpose of Pulse irradiation treatment using an excimer laser applied to the surface of a molded product can be performed under conditions of an average output of several watts to several tens of watts and a repetition frequency of 1Hz to 100Hz, thereby creating a thickness on the surface of the molded product.
An extremely thin modified layer of 1 μm or less is formed, resulting in significant improvements in adhesion, printability, and paintability. Note that since the modified layer is extremely thin, the inherent physical properties of the molded article, such as mechanical strength, are not impaired in any way. Next, specific examples will be given. Example 1 Polyethylene terephthalate films (manufactured by Mitsubishi Plastics Co., Ltd., Diafoil) were prepared, and their surfaces were irradiated with 20 pulses (10Hz2) using an ArF (wavelength 193nm) laser under conditions of pulse energy 80mJ and pulse width 10nsec. (equivalent to 2 seconds processing) was performed. The film treated with pulse irradiation in this way was divided into two parts, and the treated sides of each were glued together using a vinyl acetate emulsion adhesive (Cemedine White, manufactured by Cemedine), and after curing at room temperature for 48 hours.
T-type peel strength (adhesion strength) based on JISK6854
was measured. The results were as shown in Table 1.

[Table] Untreated: No pulse irradiation treatment Treated: Pulse irradiation treatment Example 2 On the surface of polysulfone sheet (manufactured by Nissan Chemical Co., Ltd.)
Using an Ar2 (126 nm) laser, 10 pulse irradiation (equivalent to 1 second processing at 10 Hz) was performed under conditions of pulse energy of 50 mJ and pulse width of 10 nsec. The sheet treated with pulse irradiation in this way was
Divide and apply synthetic rubber adhesive (Cemedine High Contact, manufactured by Cemedine) to each treated side.
After curing at room temperature for 48 hours, the T-peel strength (adhesive strength) was measured based on JISK6854. The results were as shown in Table 2.

[Table] Example 3 ArCl (175n
m) Using a laser, pulse energy 50mJ,
20 pulses irradiated under the condition of pulse width 10nsec (10Hz2
(equivalent to 2 seconds processing) was performed. The film that has undergone laser surface modification in this way is divided into two parts, and each treated surface is glued with an epoxy adhesive (manufactured by Konishi Co., Ltd.).
After curing for 48 hours at room temperature, the T-peel strength (adhesion strength) was measured based on JISK6854. The results were as shown in Table 3.

【table】

Claims (1)

[Claims] 1. A surface-modified synthetic resin molded product obtained by pulse-irradiating the surface of a polyethylene terephthalate or polysulfone molded product with an excimer laser having a wavelength range of 95 to 200 nm.