JPS63137930A - Selective modification of surface - Google Patents

Abstract

PURPOSE:To selectively modify surface and improve hydrophilicity as well as printability of screen printing, by irradiating a molded polyarylene sulfide article with light at a specific wavelength. CONSTITUTION:A molded article consisting of a polyarylene sulfide or a composition thereof is irradiated with light at 0.1-600nm wavelength. Poly-p-phenylene sulfide and phenylene sulfide block copolymer containing >=90mol% p-phenylene sulfide units are cited as the polyarylene sulfide. The irradiation of light is preferably carried out for >=0.01sec-<=1,000hr using light at 190-436mn wavelength. Thereby the wetting index is increased to >=40 (dyne/cm).

Description

Detailed Description of the Invention [Background of the Invention] Industrial Field of Application The present invention relates to polyarylene sulfide (hereinafter abbreviated as PAS) or molded articles made of the same composition (hereinafter abbreviated as PAS).
The present invention relates to a method of selectively modifying the surface of a (abbreviated as "S molded product") by irradiating it with light of 0.1 to 600 nm to improve its hydrophilicity.

In one embodiment, the present invention relates to a method for improving the printability of screen printing on the surface of a molded article.

BACKGROUND OF THE INVENTION PAS and its compositions have recently attracted attention as new engineering plastics with excellent heat resistance, chemical resistance, flame retardance, mechanical properties, and electrical properties.

A technique for modifying and utilizing the surface of PAS is a technique to change the crystallinity of the surface by irradiating it with a laser (heat rays with a longer wavelength and more energy than visible light) (Japanese Unexamined Patent Publication No. 60-110).
No. 729), and a technique of irradiating a strong laser of 1 x 108 to 5 x 109 Joule/sec/c& to make the surface of PAS immersive (Japanese Patent Application Laid-Open No. 127867/1986). ing.

However, although these methods have excellent surface modification effects, they require high equipment and energy costs;
Another problem was that it was difficult to adjust the energy.

[Summary of the invention]

The present inventors previously proposed a method of selectively chemically plating PAS molded products (Japanese Patent Application No. 60-28524).
No. 2). This is based on the fact that the surface of PAS that has been irradiated with light is difficult to be plated (this was the invention), but as a result of studying the modification of this surface, it was found that this surface had undergone a chemical change and had become hydrophilic. The inventors have discovered that this increases the printability of screen printing, leading to the present invention.

That is, the method for selective surface modification of a polyarylene sulfide molded product according to the present invention can be applied to a molded product made of polyarylene sulfide or the same composition with a surface modification of 0.1 to 600N.
The present invention is characterized in that by irradiating light with a wavelength of m, the surface of the light-irradiated portion of the molded article is selectively modified to improve its hydrophilicity.

Effects According to the present invention, it is possible to selectively modify a portion of the surface of a PAS molded product easily and inexpensively, using simple equipment and low energy consumption, which has been difficult to achieve with conventional surface modification methods for PAS molded products. can do.

Therefore, the present invention provides means suitable for screen printing, for example.

In other words, when screen printing a PAS molded product, in order to ensure ink adhesion, pretreatment such as etching treatment with chromic acid or special ink with improved adhesion to the PAS molded product is required. is necessary. Furthermore, if only a portion of the molded article is to be treated by etching with chromic acid, many steps are required. On the other hand, if the method of the present invention is used, the surface of the desired portion can be modified easily and selectively by using a negative mask, a method using a negative resist, or a method of scanning converged light. The hydrophilicity of the PAS molded product can be improved, and screen printing can be easily performed on the PAS molded product.

It is surprising that specific wavelengths of light with low energy levels can improve hydrophilicity, at least to the extent necessary for screen printing.

[Detailed description of the invention]

PAS molded product PAS and the same composition Polyarylene sulfide (PAS) used in the present invention
) is a homopolymer or copolymer whose main constituent unit is a repeating unit of the formula +Ar-8+. This repeating unit may be used as a main structural unit and may include a bond or a crosslink.

preferable.

Particularly preferably used PAS includes p-phenylene sulfide units as the three structural units of the polymer. to S
Examples include polyparaphenylene sulfide (PPS) and phenylene sulfide block copolymers in which ν←S) is 90 mol% or more.

PPS may contain less than 10 mol 26 of other copolymerized units, such as metaphenylene sulfide units, diphenyl ether sulfide units, and preferably 1 mol % or less of trifunctional units.

As such PPS, one synthesized by a known method can be used. Examples of the synthesis method include the method disclosed in US Pat. No. 3,354,129. This method is, for example, a method in which p-dichlorobenzene and sodium sulfide are reacted in N-methylpyrrolidone (NMP) to produce PPS. As stated in Japanese Patent Publication No. 52-12240,
Higher molecular weight PP by coexisting an alkali metal salt of an organic acid such as lithium acetate or sodium acetate during the reaction of dichlorobenzene and sodium sulfide in NMP.
A method for obtaining S is also suitable.

Other methods used to obtain higher molecular weight PPS,
For example, a method in which an inorganic salt such as lithium carbonate or calcium hydroxide is allowed to coexist during the polymerization reaction in NMP, or a method in which the amount of coexisting H2O and the polymerization temperature are controlled (
Japanese Patent Application No. 126725 (1982) may also be used. Also,
It is also possible to use a powdered polymer prepared by heating it in the presence of oxygen (preferably in air) at a temperature below its melting point to increase its melt viscosity.

As the phenylene sulfide block copolymer, a block copolymer of paraphenylene sulfide and metaphenylene sulfide is suitable. This block copolymer is a block copolymer that is substantially composed of repeating units (A) and exists in the molecular chain as a block in which 20 to 5000 repeating units (A) are bonded on average. The mole fraction (X) is 0.50 to 0.
Those within the range of 98 are preferably used.

The structure of the block copolymer with the repeating unit (A) is 90
100% by mole, and other structural units other than this repeating unit include one or more of the following.

This block copolymer can be produced by any method that allows formation of each block and bonding of both blocks, as long as it consists of repeating unit (A) blocks. For example, the method disclosed in Japanese Patent Application No. 59-134633 may be used. Specific manufacturing methods include forming one block and then forming the other block to simultaneously realize the combination of both blocks, and forming both blocks separately and then combining them. can be mentioned. Apart from taking into consideration the formation and bonding of blocks and the type of phenylene sulfide repeating units as described above, and other than modifications to be made as necessary, the method for producing the block copolymer used in the present invention is similar to that of conventional phenylene sulfide polymers. It can be said that it is not essentially different from the manufacturing method of . That is, the method for producing the block polymer of the present invention uses an alkali metal sulfide and a dihaloaromatic compound (mainly p- and m-
- dihalobenzene) by heating in an aprotic polar organic solvent (for example NMP) (dealalkali metal halide). Note that this block copolymer has a temperature of 310°C/shear rate of 200 (
The melt viscosity measured under the conditions of -1 seconds) is 1000 to 50,
It is desirable that it be in the range of 000 poise.

PAS is essentially a thermoplastic resin, and therefore, the PAS that can be used in the present invention can be used as a PAS composition by blending various additives according to the methods commonly used for thermoplastic resins. Specifically, for example, mica, TiOS t O2, Al2O3, Ca
CO3,2ゝCarbon black, talc, Ca Si O2, MgCO3
Powdered inorganic fillers such as glass, carbon, graphite,
It can be dissolved and mixed with a fibrous filler made of a material such as aramid to form a composition.

In addition, polyimide, polyamide, polyetheretherketone, polysulfone, polyethersulfone, polyetherimide, polyarylene, polyphenylene ether, polycarbonate, polyethylene terephthalate,
Blend with polybutylene terephthalate, polyacetal, polypropylene, polyethylene, ABS, polyvinyl chloride, polymethyl methacrylate, polystyrene, polyvinylidene fluoride, polytetrafluoroethylene, etrafluoroethylene copolymer, etc. to form a composition. You can also do that.

In addition to these fillers, small amounts of coupling agents, antioxidants, colorants, photosensitizers, and the like may also be used.

Manufacture of Molded Articles PAS and PAS compositions can be made into molded articles by any method that takes advantage of their properties as thermoplastic resins and goes through their melting or plastic state.

The shape of the molded product may be any shape determined by the molding method employed or the intended use of the molded product. Considering that the method of the present invention is effective in imparting hydrophilicity necessary for screen printing, it is preferable that the shape of the molded product is a film, sheet, or other object to be screen printed. You can do it.

Surface Modification The method of the present invention is a method of selectively modifying the surface of the irradiated portion by irradiating the PAS molded article with light.

The light to be irradiated in the present invention has a wavelength of 0.1 to 600 nm, preferably 190 to 43 Q nm. The irradiation time depends on the distance between the PAS molded product and the light source and the intensity of the light source, but if it is less than 0.01 seconds, it is difficult to obtain a light irradiation effect, and if it exceeds 1000 hours, productivity will be poor.
．． It is desirable that the time is 01 seconds or more and 1000 hours or less.

At this time, it goes without saying that by adding a photosensitizer or by coexisting or enriching the irradiation atmosphere with molecular oxygen, it is possible to shorten the irradiation time and thereby improve productivity.

The degree of improvement in hydrophilicity is arbitrary, but the necessary or desirable level for screen printing is a wettability index of 40 dyne/c.
It is desirable that it is more than m.

EXPERIMENTAL EXAMPLES The following examples are provided to specifically illustrate the present invention. The present invention is not limited to the following examples unless it exceeds the gist thereof.

Synthesis Example 10 NMP 4,5 in a liter autoclave
kg, and Na containing 46.02% by weight Na S
1,696 kg of 2S.5HO (10 mol as Na 2 S) was charged, and 202
683 g of water, 417 g of SNMP and 0.31 mol of H2S were distilled out while increasing the temperature to .degree. In this case, the amount of water in the system is approximately 1.33 per mole of Na 2 S.
It is a mole. After cooling to 130°C, baladichlorobenzene (PDCB 1.439 kg (PD CB /
Na2S molar ratio 1.01/1.00) and NMP
0.75 kg was added, and polymerization was carried out at 210° C. for 10 hours. Next, 466 g of water was added to this polymerization slurry with N.
The total amount of water was 4 mol per 1 mol of Na 2 S), the temperature was raised to 260° C., and polymerization was continued for 10 hours. After cooling, pearl-like polyparaphenylene sulfide (PPPS) was sieved from NMPSPPS oligomer and the like. It is then washed repeatedly with deionized water and
Drying at ℃ for 3 hours gave ppps. The yield of this polymer was 88% and the melt viscosity at 310° C./200 sec −1 was 4000 poise.

The polymer obtained by the above method is referred to as Polymer A.

EXAMPLE This is a graph showing the thickness of the polymer A described above in a single screw extruder.

A T-die sheet with a thickness of approximately 150 μm was prepared.

Cover about half of the above T-die sheet with an aluminum mask, and use a 450W high-pressure mercury lamp UM-452 manufactured by Ushio Inc.
0 minutes to 4 minutes at a distance of 28 cm from the light source to the sample.
Irradiated for hours. The wettability index of the irradiated surface and the non-irradiated surface at that time was measured by the wettability index test method of JIS K6768.

The results obtained are as shown in the attached drawings.

It is clear from the drawings that the surface wettability was selectively improved by light irradiation, and the surface was selectively modified.

Note that the representative wavelengths of the high-pressure mercury lamp UM-452 manufactured by Ushio Inc. are 302.2 nm and 313.2 nm.

334, lnm, 365.0nm, 404.7nm, 4
35.8nms 546.1nm.

It was 577.0 nm, etc.

[Brief explanation of the drawing]

The drawing shows a PAS 450W high pressure mercury lamp from a distance of 28cm.
The changes in the wettability index when the sheet is irradiated by the applicant's attorney, Sato-Osho, written amendment to the procedure, January n, 1985.

Claims (1)

[Claims] 1. By irradiating a molded product made of polyarylene sulfide or the same composition with light having a wavelength of 0.1 to 600 nm, the surface of the light-irradiated portion of the molded product is selectively A method for selectively modifying the surface of a polyarylene sulfide molded product, which is characterized by improving hydrophilicity through modification. 2. The method according to claim 1, wherein the wavelength of the irradiated light is 190 to 430 nm. 3. The method according to claim 1 or 2, wherein light is irradiated until the wetting index becomes 40 (dyn/cm) or more.