JPS6039292B2 - Paint for protecting the surface of plastic molded products - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a surface protective coating for temporarily protecting the surface of a plastic molded article, particularly a thermoplastic molded article.

Various paints have been proposed to temporarily protect the surface of plastic molded products such as decorative boards.
These have problems such as erosion of the surface of the molded product and occurrence of poor peeling.

The present invention improves these drawbacks, and has [a
l A resin component whose main component is polypynylbutyral with a degree of polymerization of 250 to 800; [b' one or more solvent components selected from alcohol solvents and ethylene glycol monoalkyl ethers; One or more plasticizer components selected from plasticizers and fatty acid plasticizers;
,' are each independently an alkyl group having 4 to 10 carbon atoms, R
The present invention relates to a paint for protecting the surface of a plastic molded article, characterized in that it contains a release agent component represented by (2 and R2' each independently represents an alkyl group having 8 to 15 carbon atoms).

In the present invention, the reason why the degree of polymerization of the polyvinyl butyral used is limited to 250 to 800 is that if it is less than 250, it is difficult to peel it off continuously after forming a coating film on the surface of the plastic molded product. This is because the viscosity of the paint becomes too high.

Furthermore, if it is diluted to lower the viscosity, the coating film will become thinner and will be difficult to peel off as a continuous coating. As the alcoholic solvent, alcohols having a carbon number of 6 or less, such as methyl alcohol, ethyl alcohol, propyl alcohol, inpropyl alcohol, butyl alcohol, and amyl alcohol, particularly monohydric alcohols are suitable.

As the ethylene glycol monoalkyl ether, methyl cellosolve, ethyl cellosolve, butyl cellosolve, inpropyl cellosolve, etc. in which the alkyl group has 4 or less carbon atoms can be suitably used. Examples of the phthalic acid plasticizer include dibutyl phthalate, dihexyl phthalate, dioctyl phthalate, diisodecyl phthalate, butylbenzyl phthalate, ditridecyl phthalate, and the like. In addition, examples of aliphatic plasticizers include dioctyl adibate, dioctyl sebacate, dibutyl sebacate,
Examples include triacetylglycerin. Further, specific examples of the release agent represented by the above general formula include dibutyltin dilaurate, dioctyltin dilaurate,
Examples include dibutyltin malate, dibutyltin laurate malate, and dibutyltin dilaurate phthalate.

In the present invention, polyvinyl alcohol is used as the resin component, but other resin components (resins that can be naturally dried, such as Alkit resin,
Nitrocellulose, etc.) can also be used. The quantitative relationship of each component in the present invention is as follows.

The quantitative ratio of the plasticizer component to 10 parts by weight of the resin component is usually 10 to 5 parts by weight, preferably 15 to 3 parts by weight.

If the amount is less than 1 part by weight, the effect of using the plasticizer will be poor, and if it is used more than 5 parts by weight, there will be a problem of tackiness at the coating edge.

The proportion of the solvent component used is usually 2 parts by weight per 10 parts by weight of the resin component.
00-200 parts by weight.

This is because if it is outside this range, it will be difficult to form a good peelable coating film on the surface of the plastic molded product.

The ratio of the release agent component used is usually 0.1 to 5 parts by weight per 100 parts by weight of the resin component. If it is too low or too low, the coating film will peel off and become thick, while if it is too high, it will tend to exhibit a blooming phenomenon, which may contaminate the surface of the plastic molded product. In some cases, silicone-based additives may be added to the coating material of the present invention in order to improve the finished appearance of the coating surface. Specific examples include silicone oil manufactured by Toshiba Silicone Co., Ltd., trade name YF-3842, TSF-
401, KP341, KP361 manufactured by Shin-Etsu Silicone Co., Ltd., etc., and the amount added is usually 0.01 to 1.0 parts per 10 parts by weight of the resin component. parts by weight.

The paint obtained by the present invention is as described above,
When this is applied to the surface of plastic moldings such as acrylic-nitrile-styrene copolymer, polyvinyl chloride, acrylonitrile styrene-butadiene copolymer, polypropylene, and polyester to form a temporary protective coating, the surface of the plastic molding is contaminated. There is no
Moreover, it could be easily peeled off when necessary.

In addition, in the present invention, the peel strength of the obtained coating film is 10
Practically desirable is less than 0g/, preferably 10 to 5 female c/o vertebrae (Tensilon manufactured by Toyo Saiki Co., Ltd. is 30 g/p).
mjn, measurements carried out at room temperature). The present invention will be specifically explained below using examples. Note that parts in the examples are parts by weight. Example 1 Polyvinyl butyral 10 anchors (manufactured by Sekisui Chemical Co., Ltd., trade name Eslec BLS) dibutyl phthalate 2 dibutyltin laurate 2 parts ethanol
35 Dark part The above components were mixed at room temperature until uniform, and a surface coating was prepared.

The obtained coating material was applied to the surface of the acrylonitrile butadiene styrene molded article and dried at 2000 to form a coating consistency.

This product was stored for - months, and the adhesion strength (peelability, tensile strength, and elongation) of the coating film was measured using a Tensilon manufactured by Toyo Keikki Co., Ltd. (2
5 qo, 30 strips/min), the weight was 140% (2 females/ground, 160 kg/min), and peeling was possible easily.

In addition, the plastic surface has not lost its optical properties before coating.
No contamination of the plastic surface due to film formation was observed.

The adhesive strength, tensile strength, and elongation of the coating film immediately after the coating film was formed were 2 thighs, 150k9/c fin, and 150% (the measurement conditions were the same as above).

Example 2 Polyvinyl butyral 10 Dark B (manufactured by Denki Kagaku Kogyo Co., Ltd., trade name Decylated Butyral 2000-D) Diisodecyl phthalate 23 parts Dibutyl tin maleate 3 parts Silicone oil
0.2 parts (trade name KS-708, manufactured by Shin-Etsu Silicone Co., Ltd.) Ethanol 60 parts Butanol 20 parts Ethylcetate.

Solve 20 Ikari The above ingredients were sealed at room temperature until uniform, and a protective paint was prepared. The resulting paint was aerosolized using dimethyl ether and liquefied petroleum gas as propellant gases, and applied to an alkyd resin board to form a coating film.

After being stored for a month, the coating could be easily peeled off, and there was no contamination on the surface of the board.

Example 3 Polyvinyl butyral 10 parts (manufactured by Sekisui Chemical Co., Ltd., trade name Eslec BM-1) Dioctyl phthalate 15 parts Cyoctyl adibate 5 parts Ethyl cellosolp
35 foundation butyl cellosolve
5. Recognized dibutyltin malate
3 parts silicone oil 0.
1 part (manufactured by Toshiba Silicone Co., Ltd., trade name: YF-3842) Each of the above components was mixed at room temperature until uniform, and a protective paint was prepared.

The obtained paint was applied to the surface of the molded product used in Example 1.
000 to form a coated finish.

Claims (1)

[Scope of Claims] 1 (a) a resin component whose main component is polyvinyl butyral having a degree of polymerization of 250 to 800, and (b) one or more solvent components selected from alcohol solvents and ethylene glycol monoalkyl ethers. , (c) one or more plasticizer components selected from phthalic acid plasticizers, and (d) general formula ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (In the formula, R_1 and R_1' are each independently Carbon number 4
~10 alkyl groups, R_2 and R_2' are each independently an alkyl group having 8 to 15 carbon atoms, or a release agent component represented by ▲a numerical formula, a chemical formula, a table, etc.) Paint for protecting the surface of molded objects.