JPS58196238A - Electroless plating process - Google Patents

Abstract

PURPOSE:A radically polymerizable compound which is brought into contact with a plastic base material is irradiated with active rays to effect grafting for smoothing the surfaces of the base material, then electroless plating is effected on the improved surfaces, thus smoothing the surfaces without any adverse effect on its properties. CONSTITUTION:A plastic base material is brought into contact with a radically polymerizable compound such as acrylic acid, e.g., by coating, irradiated with active rays such as ultraviolet or electron rays to effect grafting, thus resulting in surface improvement of the base material. Then, electroless plating is carried out. EFFECT:Process simplification.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a glass substrate whose surface has been modified by grafting a radically polymerizable compound in contact with the glass substrate by irradiating it with actinic rays such as ultraviolet rays or electron beams. It relates to a method of electroless plating on materials.

The present invention aims to improve the efficiency and physical and chemical performance of electroless plating by simplifying electroless plating. Conventional electroless plating on polymeric compounds such as plastics involves ■degreasing, ■etching (immersion in a chromic acid mixture),
■Water washing (sufficiently), ■Neutralization, ■Water washing, ■Sensitization, ■Water washing, ■Activation, ■Water washing, ■Chemical plating, and zero water washing are the long steps taken, and the conditions are complicated. , there was a problem that control was difficult. In particular, in step (2), etching is applied to suit the object to be plated, and the surface of the object to be plated is activated to have a chemical bonding force, while the unevenness and shape of the surface increase adhesion, and further plating is performed. The objective is to improve the water wettability of the object to be plated. However, in the case of plastic plating, this etching is most rate-limiting and makes the underlying surface uneven, making the roughness of the plating film more noticeable. In general, glass tiles have poor hydrophilicity, and when metal ions precipitate to form a metal film, it is difficult to obtain adhesion to the metal film. 70 to 9 as an etching agent in this solution.
The adhesive strength is increased by roughening the surface by treating it at a high temperature of about 5°C. Even when relatively harsh etching conditions are not required, it takes several minutes or more and the etching process becomes long. If the conditions are made stricter in order to shorten the time, the surface roughness will increase and the applications will be limited.

As a result of various studies to solve the above-mentioned problems, the present inventor has made the following invention which is different from the conventional method. That is, the present invention provides graft bonding of a radically polymerizable compound brought into contact with a plastic substrate by irradiating it with actinic rays such as ultraviolet rays or electron beams, thereby forming an inorganic material on the surface of the modified substrate. This is an electrolytic plating method.

Various surface treatment methods such as corona discharge treatment, oxidation treatment, flame treatment, actinic ray graft bonding, and film coating have been attempted as methods for surface modification of plastic substrates.

The corona discharge treatment, oxidation treatment, and flame treatment methods have the disadvantage of impairing the chemical properties, mechanical properties, etc. of the substrate.

Furthermore, corona discharge treatment has the disadvantage that the treatment effect itself is small and its uniformity and sustainability are poor. On the other hand, film coating not only has problems with adhesion to the polymeric substrate, but also has a two-layer structure in which the properties of the turastic substrate and the coating layer are different, so the treated substrate has its own unique characteristics. It has the disadvantage of considerably losing its mechanical and chemical properties. Incidentally, actinic ray graft bonding itself has been known for a long time, but this method generally causes less loss of properties of the treated base material and is therefore a good method.

The present invention is characterized in that the physical properties of the surface are completely changed by surface modification by graft bonding, but the surface is smooth while maintaining the chemical and mechanical properties of the base material. Further, it does not become rate-limiting like an etch knob and can perform efficient ICIIf and electrolytic plating.

Plastic substrates according to the present invention include films, sheets, plates, and other molded products made of polyethylene, polypropylene, ethylene-propylene copolymer, polyester, polycarbonate, polyimide, epoxy resin, etc., and two or more types of 7 plastics. A base material using Furthermore, dimensionally stabilized substrates reinforced with glass fibers, carbon fibers, etc. may also be used. In the present invention, since active energy ray irradiation is performed for surface modification, the shape of the substrate is preferably a film, sheet, or plate. The plated tapes, sheets, discs, etc. obtained by the present invention are superior in terms of productivity and uniformity of quality.

The plastic base material according to the present invention is preferably a glass material that is easy to graft-bond with radically polymerizable compounds by actinic rays and is not susceptible to deterioration by irradiation with actinic rays. If easy to do so, it is desirable to use ultraviolet irradiation.

The radically polymerizable compound used in the present invention includes α
, β-ethylenically unsaturated carboxylic acid monomer (α, β-ethylenically unsaturated carboxylic acid ester); examples of α, β-ethylenically unsaturated carboxylic acids include acrylic acid and methacrylic acid. , itaconic acid, fumaric acid, maleic acid, maleic anhydride, etc. In addition, as α,β-ethylenically unsaturated carboxylic acid esters, methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, butyl acrylate, butyl methacrylate, fumaric acid; dimethyl maleate, etc. As the radically polymerizable compound, radically polymerizable compounds other than α,β-ethylenically unsaturated carboxylic acid or α,β-ethylenically unsaturated carboxylic acid ester can be used, but the amount thereof is 50% by weight. less than From the viewpoint of adhesion to metals, acrylic acid,
Carboxylic acids such as methacrylic acid and maleic anhydride are good.

In surface modification, known radical polymerization initiators are used as needed.

For example, there are benzoin ethers, azobisisobutylnitrile, etc. that can be used alone, and benzophenone, acetophenone, etc. that can be used by abstracting active hydrogen from small molecules, but they are not necessarily used in the case of electron beams. In the case of ultraviolet rays, it is not necessary to use ultraviolet rays depending on the combination of the type of radically polymerizable substance and the type of base material.

Although it is possible to bring the radically polymerizable compound used in the present invention into contact with the substrate alone, it is preferable to apply it thinly to the surface of the substrate (in this case, it is preferable to use a solvent. As the solvent,
Known materials that do not melt or deform the surface of the base material may be used alone or in combination. The concentration of the solution is 001
~100% by weight, preferably 0.1~10% by weight
Weight%. Water, a mixture of water and an organic solvent, a water-soluble solvent, etc. are effective from the viewpoints of work safety, economy, and post-treatment. After surface treatment, it is necessary to remove unreacted substances, and if a polymerizable compound or solvent is used, washing with water is possible, and such a compound can be selected.

In the present invention (C), any means such as coating can be used to bring the radically polymerizable compound into contact with the surface of the base material, but when coating, known means such as roll coater 170 to coater, spraying, etc. are used. In the case of coating, the thickness of the film to be contacted is 1 to 50μ.Approximately 10μ
It is desirable to provide a protective layer with a certain thickness, and the protective layer is preferably made of polypropylene, polyester, or the like. Covering with a protective layer has the advantage that volatilization and repelling of the radically polymerizable compound are eliminated. 4. Shuasa Formation - Shikai?
1LIL death, power -′ ′ 叶 す す す す ３ 12c
In the case of rn, the line speed is preferably 0.2 to 20 m/min. If it exceeds 20 m for 7 minutes, sufficient modification will not be obtained, and if it is less than 0.2 m, the base material will deteriorate and the original properties of the base material will be impaired. To give an example of electron beam irradiation,
A dose of 0.1 to 100 Mrad is good, but
It is desirable to appropriately select the base material type from Vc. In the case of a polyester base material, 1 to 5Q Mrad is good;
Sufficient modification can be obtained at less than 1 Mrad f, 50 M
If r a d is exceeded, the line speaker becomes slow, eventually causing deterioration of the base material.

Note that, depending on the case, it is also possible to use X-rays, α-rays, etc. as the actinic light.

In the present invention, (1) the substrate is brought into contact with (1) a radically polymerizable compound, further covered with a protective film, irradiated with actinic rays such as ultraviolet rays or electron beams from the protective film or the substrate side, (1) sensitized, (2) Washing with water, ■ Activation, ■ Washing with water, ■
The process is chemical plating, ■ washing with water, and the following steps are the same as conventional methods. In this step, since etching is not performed, the surface is modified while maintaining the surface smoothness and properties of the base material. The most important feature of the present invention is that it eliminates the etching operation and allows electroless chemical plating to be performed while retaining the properties of the base material and without generating surface irregularities. Furthermore, depending on the type of base material, it is also possible to omit the sensitization operation.

The plating film obtained by the present invention is uniform, has few pinholes, and has strong adhesion.
Plating with Co, Ni, Fe, and alloys and compounds containing these as main components is effective for magnetic tapes, magnetic sheets, magnetic disks, etc. It can also be made into a printed circuit by plating it with copper or the like and later etching it into the required pattern. Furthermore, it can also be made into a pattern and used as an optical mask for printing printed circuits. According to the present invention, only the surface-modified portion is plated, so it is extremely effective in cases where double-sided plating is harmful, and is extremely advantageous for magnetic recording bodies and printed circuits. On the other hand, with conventional etching methods, it is very difficult to pre-process only one side, so this is a significant advantage. Particularly good aspects are that since no etching is performed, the plated film has no irregularities and has good gloss, which is extremely advantageous for magnetic recording materials that require smoothness, so there is no decrease in substrate surface resistance and there are fewer problems with current leakage. Note that it is also possible to treat both sides of the base material in one treatment.

Furthermore, after performing electroless plating on the plastic robe base material according to the present invention, normal electrolytic plating can be performed.

Next, the present invention will be further explained with reference to Examples.

Example 1 Sensitizing was carried out for 2 minutes using a biaxially stretched polyethylene terephthalate film base material (thickness 70 μm) with a width of 140 WrM and a length manufactured by Zen ■. After washing with water, activation is performed at 50° C. for 3 minutes using Red Schumer (manufactured by Nippon Kanizenmai). After washing with water, electroless chemical plating is performed at 60° C. for 1 minute using Blue Schumer (manufactured by Nippon Riki x 3 Zen ■), followed by washing with water. After sufficiently air-drying, the mechanical properties of the plating film were examined by rubbing it 100 times with a cotton cloth, and the condition was observed to be good. Further, the adhesiveness was tested by peeling off cellophane tape, but it did not peel off.

Electron beam irradiation and plating were carried out in the same manner as in Example 1 without using the 0.1% by weight acrylic acid acetone solution. The plated film was peeled off by rubbing once with a cotton cloth, and both the mechanical strength and adhesion of the film were poor.

Example 2 Polyimide film base material (KAPTONH type East)
(manufactured by Manufacturer) was cut to a width of 140fi and a length of 140m1C. Further, the treatment was carried out for 20 minutes while the film was open at 330°C, and although some shrinkage of the film was observed, no peeling from the plating film was observed. Also, JISC6481
The results of soldering heat resistance (260° C., 60 seconds) were also good.

Example 3 The same procedure as in Example 2 was carried out using methacrylate (lyric acid) in place of acrylic acid, and the same results were obtained and the results were good.

Example 4 The ultraviolet irradiation conditions were as follows: seven 2 KW ultraviolet lamps were arranged in parallel in a direction perpendicular to the film movement direction, the film movement speed was 10 m/min, and the distance between the film and the ultraviolet lamp was 12c1n. Polypropylene film (70
A solution of 0.1% by weight acrylic acid in acetone is applied to a thickness of 5μ on top of the film and covered with a polypropylene film of about 10μ. This sample is irradiated under the above conditions.

After washing with water, the same operation as in Example 1 was carried out and the test showed good results in both mechanical properties and adhesive properties.

Example 5 Instead of the 0.1% by weight acrylic acid solution of Example 2, 0
．． When a similar operation and test was performed using a 055% by weight acrylic acid solution, the results were similar to those in Example 2, and almost no influence of concentration was observed.

Comparative Example 2 Electron beam irradiation was performed, plating was performed, and the same operation was performed without using the 0.1% by weight acrylic acid acetone solution of Example 2. Both mechanical strength and adhesion were poor.

Example 6 Similar operations were performed using a polypropylene film base material (70μ) and electron beam irradiation 2Q M r a d in place of the polyethylene terephthalate film base material of Example 1, and tests were conducted. Mechanical strength and adhesion were determined. Both genders were good.

patent applicant Toyo Ink Manufacturing Co., Ltd.

Claims (1)

[Claims] 1. An electroless plating method, which comprises carrying out electroless plating on a plastic base material whose surface has been modified by graft bonding a radically polymerizable compound brought into contact with the base material by irradiation with actinic rays.