JPS6336876A - Method for checking thoroughness of plasma treatment - Google Patents

Abstract

PURPOSE:To evaluate the change of dye tones and to check the thoroughness of a plasma treatment by disposing a sample piece which has a porous surface and is stuck with an indophenol dye in said pores together with the surface of a base material to be subjected to the plasma treatment and subjecting the base material and sample piece to plasma treatment. CONSTITUTION:The plastic base material is subjected to the plasma treatment prior to painting to said material in order to assure the adhesiveness between said base material and the coated film by painting. The sample piece which has the porous surface and is stuck with the indophenol dye in said dyes is disposed together with the surface of the base material to be subjected to the plasma treatment and the plasma treatment is executed, then the change of the color tones of the dye after the treatment is evaluated. Namely, the thoroughness of the plasma treatment can be checked by the way how the changes take place. The sample piece obviates the splashing of the material sticking thereon on progressing of the plasma treatment and has the larger area to be subjected to the plasma treatment than in the case of sticking the material to the smooth plastic base material. The change of the color tones is thus increased and the change thereof is easily checkable.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for confirming the sufficiency of plasma treatment for plastic substrates, and in particular for ensuring the adhesion of a coating film on a plastic substrate. The present invention relates to a method for accurately and easily confirming whether or not plasma treatment, which is performed as a treatment before painting, has been sufficiently performed.

[Prior art]

In recent years, in response to social demands for resource and energy conservation, the automobile manufacturing industry, for example, has been considering various measures to improve the fuel efficiency of automobiles, one of which is changing the materials that make up automobiles. It is considered to do. In fact, instead of steel, parts are made of lightweight materials such as high-strength steel, aluminum, and plastic to make the car body as light as possible. For example, steel materials have traditionally been used for exterior parts such as pans and ξ- of automobiles, which are painted to prevent rust and look good.However, when this is replaced with plastic materials, plastic Although it is an insoluble material in itself, it is inferior to painted steel parts in terms of appearance. Therefore, coloring of plastics is currently being considered. However, since plastic inherently has a lower heat distortion temperature than steel, there is a fee to select a paint that is compatible with plastic materials for this coloring. In addition, metals generally have high surface energy, so they are unstable as they are, but they absorb moisture and acidic gases from the air, forming an oxide film on their surfaces, which lowers their surface energy and stabilizes them. On the other hand, plastics have a low surface energy and therefore have poor paint adhesion.Among plastics, polypropylene has a high degree of crystallinity, has a large contact angle with water, has a low surface energy, and is extremely non-polar. Because of this, the adhesion of paint to the surface is extremely low. Therefore, in order to improve adhesion and adhesion with the paint film, special surface treatment is required before painting.

Such pretreatment methods include conventional primer method, plasma method, ultraviolet irradiation method, chromic acid mixture method, flame method, electric discharge method,
Many methods have been considered, including radiation methods, but only the primer method has been put into practical use. However, this primer method has the problem that there are few manufacturers of primer paints to be used, and that the manufacturing cost and selling price are high. Therefore, research on the plasma method is currently underway in place of this primer method, and JP-A-Sho! ! −
/Hiro 74112 publication and the same! ! As described in Publication No. -/μ7≠33, research into practical application is currently underway, particularly focusing on surface modification of polyolefin resins such as polyethylene and polypropylene. The plasma method is a dry method;
Plasma treatment with oxygen (plasma treatment by surface oxidation) and plasma treatment with inert gas (CASING method)
There is.

Unlike the primer method, this method can pre-treat plastic substrates at low cost, but requires a method to confirm whether or not the substrate has been sufficiently plasma-treated. Conventional methods for confirming this include, for example, performing a peeling test (or adhesion test) (JIS K4rλ5P) on the paint film after painting, or checking changes in surface tension on the surface of the plastic substrate using a wetting reagent. Ta. However, with these conventional confirmation methods, the work is complicated, and the product samples are pulled out for each lot for confirmation, or the line is stopped for confirmation, which results in the line having to be stopped each time confirmation work is performed. There were many problems, including that even if the product was defective, the product had already been sent to the subsequent process, the results were not quantitative, and the confirmation work required skill.

Furthermore, in order to eliminate the problems in the above-mentioned method, it is possible to treat the plastic base material with plasma treatment to change the physical properties or color tone, such as phthalocyanine-based reactive dyes, triphenylmethane threads, or to change the degree of color tone change on the needle side. Accordingly, a method for confirming the sufficiency of plasma treatment has been proposed in Japanese Patent Laid-Open Publication No. 6/2/1410. In this method, substances that change color, such as phthalocyanine dyes, become excited during oxygen plasma treatment and exhibit a pink color, and continue to exhibit that color for about 10 minutes after being removed from the treatment tank. The color changes from reddish-purple to bluish-purple to blue. Therefore, this color change is used to confirm the sufficiency of the plasma treatment.

[Problem that the invention seeks to solve]

However, simply attaching the above substances to the plastic substrate in this way sometimes causes the attached substances to scatter during plasma treatment, making it impossible to perform satisfactory confirmation. . In addition, even if the plastic base material has good dye adhesion properties and the surface is smooth, even if the dye is applied to a thickness sufficient to prevent it from scattering, it is important to carefully check for changes in color tone. The problem was that it was not possible. This is because even if there is a large amount of dye attached to the surface of the substrate, only the dye on the surface of the dye layer changes color due to plasma treatment, and the color tone of the unchanged dye in the dye layer is actually transparent. There was a problem in that it was very difficult to confirm the changed color tone of the dye on the surface layer. In addition, phthalocyanine-based reactive dyes, triphenylmethane-based dyes, and stilbene-based dyes, which have been proposed as substances that change color tone during plasma treatment, have virtually minimal color changes, making it difficult to confirm the sufficiency of plasma treatment. There was a problem.

[Failure to solve the problem]

The present invention solves the problems of the prior art as described above, and its structure is such that the plastic base material is coated with plasma before being coated in order to ensure the immersion properties of the paint film on the plastic base material. When performing the treatment, a sample piece having a porous surface and indophenol dye adhered to the pores is placed along with the surface of the plastic base material to be subjected to plasma treatment, and plasma treatment is performed, and after treatment, This is a method for confirming the sufficiency of plasma treatment, which is characterized by evaluating changes in color tone of test specimens.

The present invention will be explained in detail below.

First, plastic base materials in the present invention include thermosetting plastics, thermosoftening plastics, natural plastics, etc. Specifically, for example, phenolic resin,
Melamine resin, epoxy resin, alkyd resin, unsaturated polyester resin, polyethylene, polypropylene, polystyrene, polyacrylic acid, polyurethane, polycarbonate, polyamide, polysulfone, silicone resin,
There are molded products such as cellulose plastic, painted products, composite molded products made of laminate, etc.For example, as explained in the conventional technology, machines such as automobile parts,
They are used as exterior parts for equipment, construction exterior parts, daily necessities, and various other products.

As explained in Section 1, these exterior parts will need to be colored later.

The paints for painting these plastic base materials include aqueous paint, oil-based paint, and emulsion-type raw material, as well as @l11M resin paint, cellulose derivative paint, and alcohol thread for each building. There are 4 different departments, including 5th grade.

The present invention is a method for confirming that the plasma treatment performed in advance is sufficient when mounting on the above-mentioned plastic base material. plate-like object,
Materials for each pillar include film, sheet, paper, and cloth.

For example, there are paper filters, cloth filters, sweet acid resin membranes with many micro-diameter pores [such as microfilters (product name)], ultrafiltration membranes, reverse osmosis membranes, reverse osmosis membranes, etc. Specific examples include filter paper, cellulose membrane filters, nylon membrane filters, polypropylene membrane filters, polyethylene membrane filters, polysulfone membrane filters, and polyvinylidene fluoride membrane filters. The indophenol dye is deposited within the pores of these porous surface specimens.

This indophenol dye has the following general formula N)
It is a compound represented by, and also includes indoaniline dyes and indamine dyes.

General formula (1) (wherein, Z represents an oxygen atom or NRIO, R1,
R2, R3, R4, R5, R6, R7, R8, RIO represent a hydrogen atom or a group capable of substituting this, and R3 and R4 or R7 and R8 may be connected to each other to form a t-membered ring. good. R9 represents a substituted or unsubstituted amino group or OM, and M represents a hydrogen atom or an alkali metal atom (eg, Na, K, etc.). ) R1, R2, R3, R4, R5, R6, R7, R8, R
Examples of the "group J that can substitute a hydrogen atom represented by 10 include a water M group, a carboxylic acid group, a sulfonic acid group, a cyan group, a hydroxyl group, a halogen atom (for example, α, Br, etc.), a nitro group, or a direct or monovalent group. linking group (e.g. -0-1-S
-1-N R1l-1-CO-1-COO-1-SO2
-1-SO3-1-NHCO-1-NH8O2-1-N
tT C00-1-N II CON H-1 etc.

Rlf represents a hydrogen atom or an alkyl group. ) Substituted or non-In-substituted alkyl group having 20 carbon atoms (e.g., methyl group, ethyl group, octyl group,
(hexabyl group, isopropyl group, hydroxyethyl group, λ-phenoxyethyl group, co(2,r-di-t-amylphenoxy)ethyl group, etc.) or an aryl group having 2 to 10 carbon atoms (e.g., phenyl group, naphthyl group) , Hiro-methoxyphenyl group, λ-hydroxyphenyl group, cochlorophenyl, f, 4'-sulfophenyl group, co, ≠-dinitrophenyl group, ≠-cyanophenyl group, λ, j-di-t-7 milphenyl group, etc. ) or heterocycle (e.g. l, 3
-thiazole ring, l, 3. ≠-triazole ring, benzothiazole ring, benzoxazole ring, benzimidazole ring, /, 3. (Hiro-thiadiazole ring, etc.).

The amine group represented by R9 is, for example, an unsubstituted amine group,
dimethylamino group, diethylamino group, N-ethyl-N
-(comethanesulfonamitoethyl)amine group, N-
Ethyl-N-(2-hydroxyethyl)amino group, N-
Represents an ethyl-N-(u-cyanoethyl)amine group, etc.

Indophenol dyes useful in the present invention are listed below.

Indofur dyes represented by the general formula (I)K of CH3 are produced by oxidative condensation of p-amine phenols or phenylene diamines with fers or anilines having a vacant p position, and are produced by, for example, Yutaka Hosoda. "Dye Chemistry" (Technical Report/Published in 937), page 719 and "Journal
e Organic ChemistryJm4AI
Vol. 77, S. Fujita (7913), to deposit these indophenol dyes into the pores of a sample piece with a porous surface, e.g. Dye, methanol, ethanol, acetone, methylketone, methine chloride/ethyl acetate, etc., are bath-dissolved and applied to the base material of the sample piece, immersing the base material of the sample piece in a bath solution in which the dye is dissolved, etc. I do. A sample piece coated with the above substance by VC is cut into a desired size and placed in the vicinity of the plastic base material when plasma treatment is performed, and as the plasma treatment progresses, the color tone of the dye changes. We look at the changes in The sufficiency of the plasma treatment can be confirmed by the state of the change.

[Action of the invention]

According to the method of the present invention, when a plastic substrate is subjected to plasma treatment, the sample piece placed in the vicinity to confirm the sufficiency of the plasma treatment is free from the adhering substances being scattered as the plasma treatment progresses. , and compared to the case of adhesion to a smooth plastic substrate, the area subjected to plasma treatment is larger, and the change in color tone is significantly increased, and the change can be observed very easily.

Next, the present invention will be explained more specifically and in detail based on examples thereof.

〔Example〕

Example / Indophenol dye 2F was mixed with the bath medium listed in Table 7 /
000mlFJJ was dissolved to prepare a dye bath solution. C, 1, Reactive Blue, as a comparative dye;
2/(7 talocyanine-based reactive dye) 2y with water i, ooo
ml and used as a comparison dye bath solution. Cellulose-based "micro filter" used as a base material for sample pieces to confirm plasma treatment (Note: Product name: manufactured by Fuji Photo Film ■)
A polyester film (Note 2, manufactured by the same company) was used as a comparison base material, and the above dye bath solution was applied onto each film by dip coating.

Note: A filtration membrane with an asymmetric structure manufactured by dissolving recycled cellulose in a mixed bath medium and casting method.

Note 2: A film with a smooth surface made of polyethylene terephthalate processed into a film using a bath melt film forming method.

After drying, each piece was cut into a size of 20 mm x j 0 m thick and subjected to plasma treatment under the following conditions.

Processing conditions Equipment: Microwave plasma processing equipment rTMW-74
tθ7” (Product name: Toshiba ■) Vacuum degree: / to
rr.

Oxygen flow i: Kooocx:, 7 minutes treatment time = 3Q second output Crab /After the so-called treatment, the changes in color tone of these sample pieces were visually evaluated by comparing them with untreated sample pieces.The results are listed in Table /. . The results ranged from l (there was no change in color tone at all compared to before plasma treatment) to yo (there was a significant change in color tone compared to before plasma treatment)! Evaluated in stages.

As shown in Table 1, indophenol dyes show the largest change in color tone when combined with porous substrates (Samples A/, 3, !, 7), and when combined with a substrate with a smooth surface (Samples A/, 3, !, 7). λ, Hiroshi, Otsu, and r), it can be seen that it is possible to confirm the plasma treatment more reliably. Furthermore, it can be seen that the change in color tone after plasma treatment is greater than that of known dyes (Sample Shop, IO).

Example λ Exemplary indophenol dye (2) or 06) and known dye C, 1, Ba5ic Violet J for comparison
(Triphenylmethane-based basic dye) was dissolved in methanol/000 nl to prepare a dye solution. The test was carried out in the same manner as in Example 2, using the base materials shown in Table 2 as the base materials of the sample pieces for confirmation. After the plasma treatment, the changes in color of these sample pieces were visually evaluated by comparing them with untreated sample pieces, and the results are listed in Table λ. Evaluation is the same as the example/! Displayed in stages.

(Note-j) A filtration membrane with a molecularly asymmetric structure (made by Boriboa M F
filter).

(Note-Ilt) Water lyamide filter manufactured by Enka ■.

(Note) A film with a smooth surface manufactured by dissolving cellulose triacetate into methylene chloride and casting it (tack film manufactured by Fuji Photo Film ■).

As shown in Table 2, in this example as well, when the indophenol dye was combined with a porous substrate (sample AI, 2, Hiro,
! , 71. r), when combined with a substrate with a smooth surface (sample A/(7, //), the degree of discoloration after plasma treatment is much greater than that of sample A/(7, //), making it possible to confirm plasma treatment more reliably. It was also found that the change in color tone after plasma treatment was greater than that of known dyes (sample cup 3.6, D).

〔Effect of the invention〕

According to the present invention, when treating the surface of a plastic base material with plasma treatment before painting, it is possible to reliably check the sufficiency of the treatment in an extremely simple way, so that each product can be inspected one by one on site. It is possible to make a check, there is no need to stop the line, the result of the judgment is clear, and the cost of coloring can be significantly reduced.

Claims (1)

[Claims] In order to ensure the adhesion between the plastic base material and the paint film, when plasma treatment is applied to the base material before painting, the base material has a porous surface along with the surface to be plasma treated. A method for confirming the sufficiency of plasma treatment, characterized in that a sample piece to which an indophenol dye is attached is placed in the hole, subjected to plasma treatment, and a change in color tone of the dye is evaluated after treatment.