JPS582978B2 - Hifukusabutsu - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to coating compositions comprising a film-forming polymer that is stably dispersed in an organic liquid.

More particularly, the present invention relates to coating compositions suitable for providing excellent visual quality in so-called metallic coatings.

Recently, so-called metallic coatings have been increasingly used mainly as top coats for automobile bodies, and there is a demand for the development of paints suitable for this purpose.

In particular, improving the appearance quality is an important issue, and many studies have been made in the industry.

Important aspects of appearance quality include so-called metal retention, solidity, image clarity, etc., and various methods have been studied to improve these, but none of them can be said to be sufficient.

As a result of intensive study on this problem, the present inventors have arrived at the present invention, which will be described in detail below.

That is, the present invention is a coating composition comprising the following components (A), (B), and (c).

(A) A polymer-containing dispersion obtained by polymerizing an ester of methacrylic acid or acrylic acid of an alcohol having 8 to 20 carbon atoms using a peroxide catalyst in a cellulose acetate butyrate solution.

(B) Hydroxyl group-containing acrylic polymer (C) Polyisocyanate compound Here, the dispersion of component (A) is dissolved in a solvent that can dissolve or heat dissolve cellulose acetate butyrate,
It is obtained by polymerizing a higher alcohol ester of acrylic acid or methacrylic acid using a peroxide catalyst in this solution.

Cellulose acetate butyrate is manufactured by Eastman
Products with various characteristic values, such as those found in Kodak Co.'s products, are used.

Products with various characteristic values can be produced depending on the degree of acetylation and butylation.

Among these, those with a degree of butyrylation of 30% or more are suitable from the viewpoint of solubility in ordinary paint solvents, and Eastman Ko is a product that meets these conditions.
dak's "EAB-381", "EAB-500",
"EAB-550", "EAB551-0.2", etc., among which "EAB-550" and "EA
B551-0.2'' is particularly preferred.

Solvents capable of dissolving such cellulose acetate butyrate vary depending on the degree of acetylation and butyrylation, and details thereof can be found, for example, in Eastman Kod.
ak's technical data "Cellulose Acetat"
e Butyrate For Protective
Coatings And Edition (Bul
Letin No. E-101)" etc.

Selection of a suitable solvent is determined by polymerizing a monomer system based on a high R alcohol ester of acrylic acid or methacrylic acid using a peroxide catalyst in a cellulose acetate butyrate solution, so that the solution obtained is more cloudy. The selection criterion is to give good results.

This standard varies depending on the type of cellulose acetate butyrate and the type of monomer.

Of course, a solution that does not become cloudy has some effect, but the effect of the present invention is fully exhibited when the solution becomes cloudy and opaque, and the composition of the present invention becomes cloudy.

Examples of solvents include methyl ethyl ketone, methylene chloride, ethyl acetate, butyl acetate, amyl acetate, ethylene chloride, cellosolve acetate, ethyl acetate, cyclohexanone, and mixtures thereof.

Among these, particularly suitable solvents include cellosolve acetate-ethyl acetate, methyl ethyl ketone, ethyl acetate, and cellosolve acetate.

Various types of peroxide catalysts can be used.

The reason why the effect is observed when polymerization is carried out using a peroxide catalyst is thought to be that the monomer used here causes graft polymerization to a greater or lesser extent with respect to the existing cellulose acetate butyrate.

Suitable examples of peroxide catalysts include the following.

methyl ethyl ketone peroxide methyl isobutyl ketone peroxide cyclohexanone peroxide acetyl peroxide lauroyl peroxide penzoyl peroxide P-chlorobenzoyl peroxide isobutyryl peroxide t-butyl hydroperoxide documene hydroperoxide di-t-butyl peroxide dicumyl peroxide 2,5-dimethyl-2,5-di(t-butylperoxy)monohexane-3 t-butyl peracetate t-butyl perpipalate t-butyl permaleate isopropyl percarbonate di3-methoxybutyl peroxy As the higher alcohol ester of carbonate succinic acid peroxide acrylic acid or methacrylic acid, those having a carbon number of 8 or more and 20 or less are suitable.

Preferred examples include octyl acrylate, ethylhexyl acrylate, inodecyl acrylate, lauryl acrylate, stearyl acrylate, octyl methacrylate, ethylhexyl methacrylate, isodecyl methacrylate, lauryl methacrylate, and stearyl C methacrylate.
Methacrylic acid of a mixture of higher alcohols from I2 to Cl4 (
Examples include acrylic acid) ester.

Among these, stearyl acrylate, lauryl acrylate, stearyl methacrylate, lauryl methacrylate, and the like are particularly preferred.

It is also possible to use small amounts of other vinyl monomers together with these esters.

When polymerization as in the present invention is carried out in the presence of cellulose acetate butyrate using a solvent that can form a solution when cellulose acetate butyrate alone or polymers of the various monomers mentioned above are dissolved individually. Although the resulting systems are often opaque, such systems give particularly good results.

The ratio of acrylic acid or methacrylic acid ester to cellulose acetate butyrate is useful in a fairly wide range, but it is usually in the range of cellulose acetate butyrate/unsaturated monomer 5/1 to 1/5,
In particular, it is preferable for this value to be in the range of 3/1 to 1/3.

The polymerization temperature is determined by the type of peroxide catalyst and solvent used, but is usually between 50°C and 200°C, with a particularly suitable range between 60°C and 150°C.

Next, the hydroxyl group-containing acrylic polymer of component (B) is an acrylic polymer containing two or more hydroxyl groups at the terminal or side chain, and can be produced by various methods.

The most common method is to polymerize a mixture of acrylic monomers, one of which is a hydroxyl group-containing monomer (eg, hydroxyethyl methacrylate).

The meaning of acrylic polymer is that at least 30% of the monomers constituting the polymer are acrylic acid and/or methacrylic acid and/or derivatives thereof.

In particular, it is preferable that the amount of these monomers is 50% or more.

Examples of these monomers include acrylic acid, methyl acrylate, ethyl acrylate, butyl acrylate, ethylhexyl acrylate, acrylamide, hydroxyethyl acrylate, methylolacrylamide, butoxymethylacrylamide, methacrylic acid, methyl methacrylate, butyl methacrylate. , isobutyl methacrylate,
Examples include ethylhexyl methacrylate, methacrylamide, hydroxyethyl methacrylate, hydroxyglobil methacrylate, methylolmethacrylamide, butoxymethylmethacrylamide.

Although various methods can be used to produce the acrylic polymer of component (B) using these monomers, solution polymerization is usually carried out.

Another suitable method is to polymerize component (B) in a solution of component (3).

Various types of polyisocyanate compounds can be used as component (C).

Examples include hexamethylene diisocyanate, xylitene diisocyanate, lysine diisocyanate, 4
・Diisocyanates such as 4'-dicyclohexylmethane diisocyanate, and 3 of these diisocyanates
triisocyanate compounds obtained by addition of 3 moles of these diisocyanates with 1 mole of a polyol such as trimethylolpropane.

Also used are so-called blocked polyisocyanate compounds in which the NCO groups of the above polyisocyanate compounds are blocked with various blocking agents.

Various known blocking agents can be used, examples of which include phenols, ethers containing a hydroxyl group, esters containing a hydroxyl group, alcohols, and alcohols containing a hydroxyl group.

Among these compounds, it is preferable to use a blocked polyisocyanate compound for <<, and thereby a composition with good storage stability can be obtained.

The proportions of components (A), (B) and (c) can vary over a fairly wide range.

On a solid basis (A)/(B)/(C)=o. 02~0.
50/1/0.05 to 0.50 and (A) and (B
) OH group in (C)/NCO group in (C) is a suitable range of 0.3 to 2.0, especially when these values are 0.05 to 0.30/1/0.10 to 0.25 and 0
．． A suitable range is 5 to 1.3.

Various methods can be used to mix components (A), (B) and (C).

The present compositions can also be made by simply mixing each component made separately, or by first forming component (A), then polymerizing component (B) in the presence of (A), and then It can also be produced by mixing component (C) therewith.

This composition can particularly exhibit its characteristics when used for automotive metallic coatings, and is therefore suitable for use as an automotive metallic paint by forming it into a paint as a formulation for metallic coatings.

In addition, it is also possible to use it in various paint formulations for other uses.

Furthermore, it is possible to provide thick film coating properties by using the coating as it is without adding pigments or fillers, and by performing so-called clear coating.

The effects obtained by the present invention include the following features.

A. A system of higher concentration and lower viscosity is obtained compared to conventional solution-type coating compositions.

Therefore, when a paint having a viscosity suitable for painting is prepared using this composition, the solid content during painting is higher than that of conventional paints.

For example, when preparing a paint for automotive metallic coatings, when adjusted to a viscosity of 16 seconds using Ford Cup #4, the solid content is approximately 20-25% in the conventional system, whereas the solid content in the system of the present invention is approximately 20-25%. is about 24-30%.

B. The coating efficiency in spray painting is good, and if spray painting is performed with the same discharge rate as conventional spray painting, the coating amount will be on the order of about 1.5 times.

C. It is possible to apply thick coats at one time, so the number of coats needed to obtain a constant coating thickness can be reduced compared to conventional methods.

For example, when baking is performed after painting, the limit at which pinholes appear is 30μ at most in conventional systems, but with paints based on the composition of the present invention, pinholes do not often occur even at a film thickness of 40μ.

D. When used as an automotive metallic paint, it exhibits very good so-called metal adhesion, which is a significant improvement over conventional paints.

E. A paint can be obtained that has significantly improved so-called sharpness and texture compared to conventional systems.

F. Compared to conventional solution types, there is less ``sagging'' and ``foaming''.

Next, the present invention will be explained by examples.

Example 1 Cellulose acetate butyrate (EAB551-0.2 Eastman Kodak) 20 parts cellosolve acetate 80 parts ethyl acetate
5. 3 parts (manufactured by Seiko Co., Ltd.) was dissolved, 21.0 parts of stearyl methacrylate, 2.6 parts of hydroxypropyl methacrylate, and 0.44 parts of benzoyl peroxide were added, and the mixture was heated to reflux temperature (approximately 83°C) to perform polymerization. Ta.

After heating for about 5 hours, styrene
13 parts butyl methacrylate
27 parts butyl acrylate 1
4 parts hydroxyglopyl methacrylate 14 parts acrylic acid 0.5 parts azobisisobutyronitrile o. 9 parts were added dropwise over 2 hours, and the mixture was further heated for 1 hour.

Further add 0.5 part of azobisisobutyronitrile,
Heating was continued for an additional 2 hours to increase the polymerization rate.

The obtained liquid was a milky white liquid, and the Gardna bubble viscosity at 30°C was ST.

82 parts of this festival, aluminum pigment "Alpaste 1700"
A paint was prepared by mixing 3 parts of "NAL" (manufactured by Toyo Aluminum Co., Ltd.) using a shaking type paint blending machine, and further blending 18 parts of "Coronate HL" (manufactured by Nippon Polyurethane Co., Ltd.) consisting of an adduct of hexamethylene diisocyanate.

Add this to acetone 10 parts ethyl acetate 40 parts toluene 15 parts naphtha #5
Diluted with thinner consisting of 15 parts cellosolve acetate and 20 parts and adjusted to 16 seconds in a Ford Cup #4.

The solid content at this time was 29%.

This paint was spray-coated onto a tin plate so that the dry film thickness was 30 μm.

This was set for 10 minutes and then heated and cured at 140° C. for 30 minutes.

The resulting coating film was free of foaming and pinholes, and had excellent metal retention, sharpness, and texture.

Example 2 Cellulose acetate butyrate (EAB550 manufactured by Eastman Kodak) was added to 40 parts of cellosolve acetate and 60 parts of butyl acetate.
Dissolve 6 parts isotesyl methacrylate 15 parts hydroxyglopyl methacrylate 2.0 parts acrylic acid
0.12 parts benzoyl peroxide
0.2 part was added and heated to about 90°C to carry out polymerization.

After heating for about 5 hours, lauryl methacrylate 23 parts methyl methacrylate 28 parts butyl methacrylate 25 parts hydroxyethyl methacrylate 16 parts methacrylic acid
1 part Azobisisobutyronitrile
0.9 part was added dropwise over 2 hours, and the mixture was further heated for 1 hour.

Next, 0.4 part of azobisisobutyronitrile was added,
It was heated for an additional 2 hours.

The obtained liquid was a milky white stable liquid, and the Gardna bubble viscosity at 30°C was QR.

This solution was stored at 50°C for one month, but no change was observed.

85 parts of this festival, aluminum pigment "Alpaste 1700"
A paint was prepared by mixing 4 parts of ``NAL'' (manufactured by Toyo Aluminum Co., Ltd.) using a shaking type paint blending machine, and further blending 15 parts of ``Dismodule N'' (manufactured by Sumitomo Bayer Urethane Co., Ltd.).

Add this to 50 ethyl acetate
Part toluene 25 parts Naphtha #5 15 parts Cellosolve acetate 10 parts Diluted with thinner and adjusted to 17 seconds in a Ford Cup #4.

The solid content at this time was 29%.

This paint was spray-coated onto a tin plate so that the dry film thickness was 30 μm.

This was set for 10 minutes and then heated and cured at 140° C. for 30 minutes.

The resulting coating film was free of foaming and pinholes, and had excellent metal adhesion, sharpness, and texture.

Example 3 Solbetsuno #150 70 parts butyl acetate 30 parts, cellulose acetate butyrate (EAB550 manufactured by Eastman Kodak)
7 parts were dissolved, and was added thereto, and the mixture was heated to about 85°C to carry out polymerization.

After heating for about 5 hours, 2 ethylhexyl methacrylate} 20 parts methyl methacrylate 26 parts inbutyl methacrylate 20 parts hydroxypropyl methacrylate 14 parts methacrylic acid
1 part Azobisisobutyronitrile 0.
8 parts were added dropwise over 2 hours, and the mixture was further heated for 1 hour.

Next, 0.4 part of azobisisobutyronitrile was added,
Heating was continued for an additional 2 hours.

The obtained liquid was a milky white stable liquid, and the Gardner bubble viscosity at 30°C was P-Q.

This liquid was stored at 50°C for one month, but no change was observed, indicating that the stability of this liquid was good.

85 parts of this Fes, 11 parts of ``TEIS MODULE AP Stable'' (manufactured by Sumitomo Bayer Urethane), which is a phenol block type polyfunctional polyisocyanate, 4 parts of ``Ebicoat 1001'', an epoxy resin (manufactured by Shell),
A paint was prepared by mixing 20 parts of titanium oxide and 4 parts of butalon animble using a shaking paint blender.

This was coated on a zinc phosphate treated steel plate (Bonderite #37, thickness 0.28mm) to obtain a dry film thickness of 30μ, and after setting for 10 minutes, it was heated to 240℃ for 5 minutes.
Heat cured for a minute.

The resulting coating film was free from foaming and pinholes and had excellent gloss.

Example 4 A white enamel was obtained by kneading.

This was diluted with a thinner consisting of 40 parts of xylene, 20 parts of Solbetuso #100, 30 parts of Solbetuso #150, and 10 parts of cellosolve acetate, and adjusted to 19 seconds using Ford Cnp #4.

The solid content at that time was 32%.

This was spray-coated onto a zinc phosphate-treated steel plate (Bonderite #144, thickness 0.60 mm) to a film thickness of 40 μm, and after being set for 15 minutes, it was heated and cured at 160° C. for 30 minutes.

The resulting coating film was free of foaming and pinholes, and had excellent gloss, sharpness, and texture.

Example 5 Cellulose acetate butyrate (EAB551-0.2 Eastman Kodak) was added to 11 parts of cellosolve acetate and 22 parts of ethyl acetate.
(manufactured by 7bu Co., Ltd.) was dissolved, and was added thereto, and the mixture was heated to about 85 to 90°C to carry out polymerization.

Heating was performed for about 5 hours to obtain a milky white dispersion.

Meanwhile, 60 parts of toluene and 40 parts of butyl acetate were heated to 90°C, and into this solvent were added styrene 20 parts butyl methacrylate 24 parts butyl acrylate 22 parts hydroxyglopyl methacrylate 16 parts acrylic acid
1 part Azobisisobutyronitrile
o. 9 parts were added dropwise over 2 hours, and the mixture was further heated for 1 hour.

0.2 parts of azobisisobutyronitrile was added three times at 1 hour intervals, and heating polymerization was continued.

The polymerization was completed by further heating for 2 hours.

While stirring the above dispersion, the obtained Fes was added and mixed to obtain a milky white dispersion as a whole.

The viscosity was Gardner bubble viscosity R-S at 30°C.

This dispersion was left at 50° C. for one month and was stable.

A paint was prepared by mixing 80 parts of this Fes, 20 parts of "Coronate HL" and 6 parts of aluminum pigment.

Add this to acetone 10 parts ethyl acetate 40 parts toluene
15 part naphtha #5
15 parts cellosolve acetate
Diluted with thinner consisting of 20 parts of Fo
Adjusted to 16 seconds with rd Cup #4.

The solid content at this time was 28%.

This paint was spray coated onto a tin plate so that the dry film thickness was 30 μm.

After setting this for 10 minutes, it was heated and cured at 140° C. for 30 minutes.

The resulting coating film was free of foaming and pinholes, and had excellent metal adhesion, sharpness, and texture.

Claims (1)

[Claims] 1 (A) Contains a polymer obtained by polymerizing an ester of methacrylic acid or acrylic acid of an alcohol having 8 to 20 carbon atoms using a peroxide catalyst in a cellulose acetate butyrate solution. Dispersion liquid (B) hydroxyl group-containing acrylic polymer and (C)
A coating composition comprising a polyisocyanate compound.