JPH0753262B2 - Painting method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an amine permeable curing coating method,
More specifically, the present invention relates to an amine permeable curing coating method using a polyurethane resin paint capable of obtaining a coating film in which physical properties of the coating film, particularly flexibility and tensile strength are well balanced.

[Conventional technology]

Conventionally, there is a known coating method in which an object to be coated is coated with a urethane resin coating, and then the coating film is cured in an amine atmosphere in a vapor phase state. JP-A-60-31533 and 58-5345, which are also known to be used for suppression, and JP-A-58-78737 are known as coatings for RIM.

[Problems to be solved by the invention]

However, in the conventional amine permeable curing method, a polyurethane resin paint is rapidly cured by an amine catalyst to obtain a coating film, and thus the obtained coating film has the same characteristics as a general polyurethane coating film. As for the relationship between tensile strength and elongation, the tensile strength decreased when the elongation was increased, and the elongation decreased when the tensile strength was increased.

Therefore, if it is applied to a material such as SMC that has relatively large holes, it has insufficient elongation or insufficient tensile strength to suppress foaming, or RIM is reinforced with glass fiber such as R-RIM. When coated on a material or the like, if the tensile strength is large, the image clarity is improved, but the low temperature properties are remarkably inferior due to insufficient elongation and there is a problem of lack of practicality.

[Means for solving problems]

The present inventors have conducted extensive studies for the purpose of balancing these film strengths, and as a result, by blending whiskers or glass fibers into a polyurethane resin coating which is curable in the amine vapor phase state, the amine vapor phase after coating can be improved. It was found that the conventional problems can be solved by curing with.

The present invention is a coating method in which an object to be coated is coated with a urethane resin coating, and then the coating film is cured in an amine atmosphere in a gas phase state, wherein the urethane resin coating has a length of 100 parts by weight of a resin component. Is 2 to 30 .mu.m and 5 to 70 parts by weight of glass fibers or whiskers having a diameter of 1/3 or less of the length are contained.

The present invention is capable of being cured at room temperature for a short time, and the obtained coating film is a coating film having a well-balanced tensile strength and elongation due to the reinforcing effect of whiskers or glass fibers. It exerts a great effect on suppressing foaming of a relatively large porous material or suppressing thermal fluctuation of a material such as R-RIM which causes a deterioration in appearance due to heat. This means that the field to which the conventional amine permeable curing coating method is applied can be applied as a matter of course, and the target material can be widely spread to take advantage of the low temperature and short time curing.

In the amine resin curable urethane resin coating used in the present invention, a polyol such as acrylic, polyester, alkyd, polyolefin or polyether is used as a polyol, and a combination resin system of two or more of these polyols can also be used. .

Polyisocyanates suitable for use in the present invention also include toluylene diisocyanate (TDI) diphenylmethane diisocyanate (MDI), methylene diisocyanate, xylelline diisocyanate (XDI), hexamethylene diisocyanate (HMDI), isophorone diisocyanate (IPDI), triphenylmethane. Triisocyanate, phenylene diisocyanate, limine diisocyanate,
And the above-mentioned methylol adducts, trimers and pentamers, and further mixtures thereof.

The amine used in the present invention in the vapor phase is preferably a tertiary amine, for example, an aliphatic tertiary amine such as trimethylamine, triethylamine, tripropylamine, tributylamine, triamylamine, dimethylaniline, diethyltriamine, triamine Aromatic amines such as Ribenzylamine, N-methylmorpholine, N-ethylmorpholine, or triethanolamine, methyldiethanolamine, dimethylethanolamine, diethylethanolamine, dibutylethanolamine, di (2-ethylhexyl) ethanolamine, ethyl Alkanol amines such as diethanolamine, triisopropanolamine, dibutylisopropanolamine, triisopropanolamine and dibutylisopropanolamine. There dimethylethanolamine even during use, preferably triethylamine.

As the atmosphere of the above amines, the amine concentration in the gas phase is suitably about 10 to 3000 ppm, preferably 300 to 1200 ppm, and the temperature is suitably 0 to 80 ° C, preferably 20 to 40 ° C. The passage time in the amine gas phase varies depending on the resin composition, film thickness, kind of amine, temperature and concentration, etc., but is generally 1 to 10 minutes, preferably 2 to 4 minutes.

After the treatment in the amine gas phase after coating, it may be further heated at a temperature of 100 ° C. or lower for 3 to 20 minutes if necessary.

Whiskers or glass fibers used in the present invention,
Even if the size is not limited so much, the effect of the present invention can be obtained, but since the effect is further produced, the length 2 to
Those having a diameter in the range of 30 μm and not more than 1/3 of the length, preferably 5 to 20 μm and having a diameter of not more than 1/3 of the length are used. The rice car here is a whisker-like crystalline compound, and examples thereof include silicon carbide, silicon nitride, potassium titanate, magnesium silicate, and calcium sulfate.

Here, if the length exceeds 30μ, the appearance of the coating film deteriorates and 2μ
In the following, the balance between tensile strength and elongation is lost, the effect is halved, and when the diameter is more than 1/3 of the length, the effect of the present invention tends to be deteriorated and it is more preferable to limit the range of the length and the diameter. This produces a further effect.

The amount of whiskers or glass fibers mixed with the resin component in the urethane resin coating is 5 to 70 parts by weight, preferably 8 to 50 parts by weight, based on 100 parts by weight of the resin component.

If the blending amount of whiskers or glass fibers is less than 5 PHR (PHR indicates the amount by weight relative to 100 parts by weight of resin), a coating film having a good balance of tensile strength and elongation cannot be obtained as the obtained coating film, or If it exceeds 70 PHR, the appearance of the coating film is inferior and the cost of the coating material increases, which is not preferable.

The amine vapor phase urethane resin coating used in the present invention is, of course, known pigments such as various coloring pigments (extensive pigments), surfactants, defoaming agents, additives such as leveling agents, esters, It may contain a ketone, an aliphatic or aromatic hydrocarbon solvent or the like.

When the urethane resin paint according to the method of the present invention is applied and then the coating film is cured in an amine atmosphere, even if the coating film formed at this time is not completely cured in the amine gas phase, it is exposed to high temperature thereafter. However, it was found that no abnormalities occurred.

A known coating method such as air spraying, airless spraying, electrostatic spraying is applied as a method of applying the amine vapor phase urethane resin paint used in the present invention.

Further, it is also possible to further coat a thermosetting resin paint or a urethane resin paint on the urethane coating film formed in the present invention.

〔Example〕

 The present invention will be described below with reference to examples.

Example 1 Urethane resin paint for amine vapor phase curing (acrylic resin made by Shinto Paint # 30: S pigment component / resin component (hereinafter referred to as P / B) =
0.7 / 1 solid content 58%)-Comparative paint No. 1-100 parts by weight Tesmo D (Otsuka Chemical potassium titanate whiskers)
8.3 parts by weight (20 PHR) was added to obtain a paint, and this paint 108.
To 3 parts by weight, 10 parts by weight of Takenate D-1110N (xylylene diisocyanate manufactured by Takeda Pharmaceutical Co., Ltd.) was used as a curing agent.

After degreasing the SMC with IPA, spray paint the above paint to a film thickness of 35μ, set at 2 minutes / 20 ° C, and set the wind speed to 0.8m / sec in the gas phase of dimethylethanolamine 600ppm for 2 minutes / It was left at 30 ° C. After that, a cured coating film was obtained after drying at 30 ° C for 10 minutes. Example 2 A melamine alkyd paint (Glymine # 100 manufactured by Shinto Paint Co., Ltd.) white was applied onto the cured coating film obtained in Example 1, and 140 ° C x 40 The coating film was baked for a total of 65μ to obtain a coating film.

Example 3 Polyolefin-based amine vapor phase curing urethane resin coating material (Shinto Paint Co., Ltd. Bepon # 2012: P / B = 0.8 / 1 solid content 57%)-
Comparative paint No. 2 -100 parts by weight DENTOL WK-100
4.4 parts by weight (10 PHR) of potassium titanate whisker (Otsuka Chemical Co., Ltd.) was added to obtain a paint, and 16 parts by weight of Takenate D-110N was used as a curing agent for 104.4 parts by weight of the paint.

A cured coating film was obtained in the same manner as in Example 1 except that R-RIM was used as the material.

Example 4 On the cured coating film obtained in Example 3, a polyurethane resin paint (Porin # 1 manufactured by Shinto Paint Co., Ltd.) white was applied and dried at 80 ° C. for 30 minutes to obtain a coating film of 65 μm in total.

Example 5 A cured coating film was obtained in the same manner as in Example 1 except that 24.9 parts by weight (60 PHR) of glass fiber having a length of 20 μm and a diameter of 3 μm was used instead of Teismo D in Example 1.

Example 6 Glymine # 100 white was applied onto the cured coating film obtained in Example 5 and baked at 140 ° C. for 40 minutes to obtain a coating film of 65 μm in total.

Examples 7 to 10 A coating film having a thickness of 35 μm was obtained in the same manner as in Example 5 except that the glass fiber in the proportion shown in Table 3 was added to the comparative paint No. 1.

Comparative Example 1 100 parts by weight of comparative paint No. 1 was used as a curing agent of 100 parts by weight of Takenate D-110N and cured under the same curing conditions as in Example 1 to obtain a 35 μm cured coating film.

Comparative Example 2 Using the cured coating film obtained in Comparative Example 1, Glymine white was coated on the cured coating film and baked at 140 ° C. for 80 minutes to obtain a coating film of 65 μm in total.

Comparative Example 3 100 parts by weight of the comparative paint No. 2 and 16 parts by weight of Takenate D-110N were used as a curing agent, and R-RIM was used as a raw material to obtain a cured coating film of 35μ under the same curing conditions as in Example 1. .

Comparative Example 4 Porin # 1 white was applied on the cured coating film obtained in Comparative Example 3,
It was dried at 80 ° C for 30 minutes to obtain a coating film of 65μ in total.

Comparative Example 5 Example 1 except that 1.6 parts by weight (4 PHR) of Tismo D was used.
A 35 μm cured coating film was obtained in the same manner as in.

Comparative Example 6 Glymine # 100 white was applied on the cured coating film obtained in Comparative Example 5 and baked at 180 ° C. for 80 minutes to give a total coating thickness of 65 μ to obtain a coating film.

Comparative Example 7 A 55 μm cured coating film was obtained in the same manner as in Example 1 except that 31.1 parts by weight (75 PHR) of Teismo D was used.

Comparative Example 8 Glymine # 100 white was applied onto the cured coating film obtained in Comparative Example 7 and baked at 140 ° C. for 40 minutes to obtain a coating film of 65 μm in total.

The results of coating performance tests performed on Examples 1 to 10 and Comparative Examples 1 to 8 are shown in Tables 1 and 2, and Tables 3 to 4 show the glass fibers and whiskers used.

Test method Tensile strength-Coatings are cut into lengths of 20 m / m and tested in a tension tensile tester.

Elongation rate-Same as above Appearance of coating-Visual check Pinhole-Visual check Image quality-Measured by PGD ○ -Good △ -Slightly bad × -Poor [Effect of the invention] According to the method of the present invention, the urethane resin coating is a whisker. Alternatively, since it is reinforced with glass fiber, a coating film with a balanced tensile strength-elongation rate can be formed by rapid curing at room temperature, and thus it has the effect of suppressing foaming of the thermosetting plastic and improving the appearance. A new type of coating that is extremely strong and flexible, and can be widely applied to other materials.

Claims (1)

[Claims] 1. A urethane resin paint is applied to an object to be coated,
Next, a coating method of curing a coating film in an amine atmosphere in a gas phase, wherein the urethane resin coating composition is a resin component 10
A coating method characterized by containing 5 to 70 parts by weight of whiskers or glass fibers having a length of 2 to 30 μm and a diameter of 1/3 or less of 0 parts by weight.