JPH11124541A - Resin composition for powder coating material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resin compsn. for a powder coating material which can form a coating film excellent in weatherability without detriment to flexibility by compounding a hydroxylated polyester resin with a hydroxyl-reactive curing agent and a specific surface modifier. SOLUTION: A polyester resin formed mainly from an arom. dicarboxylic acid component and an aliph. glycol component and having a hydroxyl value of 13-100 mgKOH/g, pref. 20-60 mgKOH/g, a number average mol.wt. of 3,000-10,000, pref. 4,000-7,000, and a glass transition temp. of 50-80 deg.C, pref. 55-70 deg.C, is compounded with at least one hydroxyl-reactive curing agent selected from among aminoplasts, blocked isocyanates, and polybasic acid anhydrides and 1-15 pts.wt. (based on 100 pts.wt. sum of the resin and the curing agent) surface modifier comprising an acrylic copolymer having surface-modifying capability and ultraviolet-absorbing groups at the molecular ends or on the side chains.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a novel and useful resin composition for powder coatings. More specifically, the present invention comprises, as essential components, a hydroxyl group-containing polyester resin, a curing agent having reactivity with the hydroxyl group, and a surface conditioner comprising an acrylic copolymer having a surface conditioner. The present invention relates to a resin composition for a powder coating mainly used for coating a building material, a metal product and an automobile.

[0002]

2. Description of the Related Art By the way, polyester powder coatings are
Compared to conventional solvent-based resins, home appliances are mainly used because of their advantages such as low pollution, excellent flexibility, and relatively low cost. For protecting various components such as products or building materials or automobile parts, and as decorative paint,
Demand is growing.

[0003] However, such a polyester resin having excellent flexibility has a problem that, in a very short time, whitening or chalking is caused and glossiness is remarkably reduced, and in particular, the weather resistance is poor.

In order to solve such a problem, studies have been made on improving the weather resistance from the viewpoint of the composition of the polyester resin, and a technique disclosed in Japanese Patent Application Laid-Open No. Hei 9-71728 has been proposed. There is.

[0005] However, these can be applied only to specific applications because the weather resistance is dramatically improved, but the flexibility is extremely reduced. In other words, this type of polyester resin is used in the process of producing a paint.
Since the resin is mixed with the curing agent and various additives and melt-kneaded, it must be kneadable at a temperature that does not react with the curing agent. The kneading temperature of the resin is 150 ° C.
Is the upper limit. Further, in order to impart flexibility to the coating film after heat curing, it is desirable to appropriately include an aromatic component and an aliphatic component.

For these reasons, as a polyester resin for thermosetting powder coatings, generally, ethylene glycol, terephthalic acid, and a third component are further copolymerized to lower the softening point temperature. Shapes are widely used. And, as such a third component, various ones can be used, but when weather resistance is required,
Neopentyl glycol and isophthalic acid are mainly used.

[0007] However, copolymerization of polyethylene terephthalate with neopentyl glycol improves the weather resistance to some extent, but is still insufficient for applications requiring high weather resistance. Is the actual situation.

[0008] Also, by replacing the terephthalic acid in polyethylene terephthalate with isophthalic acid, the weather resistance is just the place to be improved. However, since the flexibility is remarkably reduced, a polyester resin for a thermosetting powder coating, which at the same time has both flexibility and weather resistance, is still not obtained. The fact is that it has not been done.

[0009]

SUMMARY OF THE INVENTION However, in view of the above-mentioned various drawbacks or defects in the conventional technology, the present inventors have hitherto proposed a thermosetting powder mainly composed of a polyester resin. In the field of paints, we have begun to study the compatibility of mechanical properties and weather resistance, which have been difficult in polyester-block isocyanate-cured powder paints.

Accordingly, an object of the present invention is to provide a thermosetting material having extremely high practicality in which both mechanical properties and weather resistance are compatible. An object of the present invention is to provide a resin composition for a powder coating.

[0011]

Means for Solving the Problems Accordingly, the present inventors have:
Focusing on the problem to be solved by the invention as described above, as a result of diligent and repeated studies, a specific surface conditioner in the form of having an ultraviolet absorbing ability, a hydroxyl group-containing polyester resin, and a hydroxyl group-containing polyester resin A resin composition for a powder coating obtained by using a curing system comprising a curing agent having a reactivity with a resin, in fact, finds that weather resistance can be drastically improved without impairing flexibility. Now, the present invention has been completed.

That is, the present invention basically relates to a polyester resin (a) having a hydroxyl group as an essential component.
And a curing agent (b) having reactivity with the hydroxyl group, and a surface conditioner (c) comprising an acrylic copolymer having a surface conditioner. To provide the composition,

In addition, the above-mentioned surface conditioner (c) is used in a total amount of 10% of the polyester resin (a) and the curing agent (b).
An object of the present invention is to provide a resin composition for powder coatings, which is contained in an amount of 1 to 15 parts by weight based on 0 part by weight.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail.

That is, first, the most important component among the components constituting the resin composition for powder coating according to the present invention, the above-mentioned surface conditioner comprising an acrylic copolymer having an ultraviolet absorbing ability ( In the case of c), it is an acrylic copolymer itself having a surface adjusting ability, preferably in a form in which a terminal or side chain is provided with a special structure having an ultraviolet absorbing group. is there.

If only a typical structure having an ultraviolet absorbing ability is exemplified, it may be a structure having a benzotriazole skeleton or a structure having a benzophenone skeleton. As a method for introducing such a structure having various skeletons into the terminal or side chain of the acrylic copolymer, a method of polymerizing a polymerizable monomer having a benzotriazole skeleton, or A common method is to copolymerize a polymerizable monomer having a benzophenone skeleton with another polymerizable monomer copolymerizable with the monomer.

If only a typical example of such an introduction method can be described, 2- (2 ′
-Hydroxy-5'-methacryloxyethylphenyl)
-2H-benzotriazole [R made by Otsuka Chemical Co., Ltd.
UVA-93 ”] and the like, and such a method of polymerizing such a“ RUVA-93 ”and other copolymerizable monomers. , It can be easily introduced.

As the copolymerizable monomers mentioned here, only typical ones are exemplified, and examples thereof include alkyl esters of acrylic acid or methacrylic acid.
If only typical examples of such alkyl esters of (meth) acrylic acid are given as examples, (meth)
Methyl acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, iso (-meth) acrylate
so) butyl, (meth) acrylic acid tertiary (t
-, Tert- or tert-) butyl, 2-ethylhexyl (meth) acrylate or cyclohexyl (meth) acrylate, and furthermore, for example, styrene, vinyltoluene or α-methylstyrene is also used. I can do it.

Various hydroxyl group-containing monomers such as hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate or hydroxybutyl (meth) acrylate; half of methacrylic acid or acrylic acid or maleic acid; Various carboxyl group-containing monomers such as ester (semi) ester can be used, and furthermore, a macromonomer having a polymerizable group at a terminal (however, the number average molecular weight is up to 6,000. ) Also has a large surface modification effect and can be used moderately.

As a method for producing a surface conditioner, which is different from the above-mentioned method, an acrylic copolymer having a specific functional group and an ultraviolet absorber having a functional group reactive with the functional group are used. Examples of such a method include reacting.

As a typical example of such a production method, a copolymer of isocyanateethyl methacrylate and a copolymerizable monomer as described above may be added to a copolymer of "Sumisorb400" [Sumitomo]. And a method of reacting a so-called benzophenone-based ultraviolet absorber having a hydroxyl group.

The difference between the solubility parameter of the surface modifier (c) used in the present invention and the solubility parameter of the polyester resin is desirably 1 or more. That is, the surface conditioning ability means having a difference of one or more solubility parameters.

The measurement of the solubility parameter value employed in the present invention is described in Suh, Clarke, J .; Poly
m. , Sci. , A-1, 5, 1671-1681 (1
967), according to the method based on the measurement of a turbidity point. The measurement temperature at that time is 20 ° C
And the solvent is tetrahydrofuran (TH
F).

In the case where the difference in the solubility parameter is less than 1, the surface controllability tends to be low, and the weather resistance cannot be sufficiently improved. The number average molecular weight of the surface conditioner (c) is 2,500 to 25,0.
00 is appropriate, preferably 3,000 to
A range of 15,000 is appropriate. If this molecular weight is too low, by all means, especially, the blocking resistance tends to decrease, and it is difficult to sufficiently exert the surface conditioning effect. Either case is not preferable because the smoothness is impaired.

The surface conditioner (c) is used in an amount of 1 to 1 with respect to 100 parts by weight of the total amount of the polyester resin (a) having a hydroxyl group and the curing agent (b) reactive with the hydroxyl group.
The range of 5 parts by weight is more preferably 2.5 to 10 parts by weight.
A range of parts by weight is appropriate. If the amount is less than 1 part by weight, the surface conditioning effect tends to be low, while
If it is too much more than 15 parts by weight,
In any case, the glossiness and the like of the coating film are reduced, so that either case is not preferable.

Next, the above-mentioned hydroxyl group-containing polyester resin (a) constituting the resin composition for powder coating according to the present invention is mainly composed of an aromatic dicarboxylic acid component and an aliphatic glycol component. A compound having a form as a constituent component is designated. If only particularly typical examples of the aromatic dicarboxylic acid referred to here are exemplified,
Various aromatic dicarboxylic acids represented by terephthalic acid, isophthalic acid, phthalic anhydride, phthalic acid or naphthalenedicarboxylic acid; or succinic acid, adipic acid, suberic acid, sebacic acid or 1,10-decanedicarboxylic acid And various aliphatic dicarboxylic acids represented by

Further, tetrahydrophthalic anhydride,
Various alicyclic dicarboxylic acids represented by 1,4 cyclohexanedicarboxylic acid or 1,2-hexahydrophthalic anhydride can be used in combination, and the polyester obtained together with the dicarboxylic acid component can be used. Various trivalent or higher carboxylic acid components such as trimellitic acid or pimellitic acid can be used in combination as long as the resin is not gelled.

On the other hand, in the preparation of the polyester resin (a), neopentyl glycol, ethylene glycol,
1,2-propanediol, 1,3-propanediol, 1,3-butanediol, diethylene glycol,
Propylene glycol, 1,4-butanediol, 1,
Various aliphatic glycols represented by 6-hexanediol, 1,4-cyclohexanedimethanol and the like.

Further, diols having various aromatic groups, such as ethylene oxide adducts of bisphenol A and ethylene oxide adducts of bisphenol S, can be used in combination in a small amount.

Further, together with the above-mentioned glycol component, various tri- or higher-valent alcohol components such as glycerin, trimethylolpropane, pentaerythritol and the like may be added to the extent that the resulting polyester resin is not gelled. Can be used together.

Further, if necessary, various oxycarboxylic acid components such as 4-hydroxybenzoic acid and ω-caprolactone may be used in combination, with a limitation of a small amount. Of course.

Among the polyester resin compositions listed above, the powder coating itself, in particular,
In order to simultaneously satisfy curability, good mechanical properties and storage stability, it is common to use terephthalic acid as the main component as the acid component.

The polyester resin to be used in the present invention is a polyester resin whose terminal is mainly a hydroxyl group, and the hydroxyl group has a hydroxyl group of 10 to 100 mg KOH.
/ G, preferably 20 to 60 mgK
OH / g is desirable.

When the hydroxyl value is less than 10 mgKOH / g, the crosslink density tends to be reduced, and thus, sufficient curability cannot be obtained. As a result, it is difficult to obtain a product having sufficient performance, and on the other hand, 100 mg KO
In the case of exceeding H / g and exceedingly high, the mechanical strength of the coating film tends to decrease, so that it is not preferable in any case.

Next, referring to the molecular weight of the polyester resin (a), the number average molecular weight is suitably in the range of 3,000 to 10,000, and when the number average molecular weight is less than 3,000, Inevitably leads to a decrease in the crosslink density, which is not desirable in terms of the performance of the coating film. On the other hand, if it exceeds 10,000 and becomes too high, the grindability of the coating material itself is inevitable. In any case, it cannot be said to be a preferable source, since it becomes significantly lower. Preferably, 4,000-
A range of 7,000 is appropriate.

If the glass transition temperature of the resin (a) is to be referred to, the range of 50 to 80 ° C. is appropriate. , Or causes a decrease in grindability, etc. On the other hand, if the temperature exceeds 80 ° C. and becomes too high, inevitably, the smoothness of the coating film tends to decrease. Because it is in
Neither case is a preferred source. Preferably,
A range of 55 ° C to 70 ° C is appropriate.

On the other hand, the curing agent (b) capable of reacting with the hydroxyl group in the polyester resin (a), that is, the curing agent (b) having a functional group capable of reacting with the hydroxyl group, is represented by A compound having a functional group that reacts with a hydroxyl group of the compound. The curing agent may be, for example, an aminoplast, a polyisocyanate compound, a block copolymer or a polyisocyanate compound. Isocyanate compounds or polyanhydride compounds.

First, as the above-mentioned aminoplasts, only typical ones may be mentioned.
Various amino-containing compounds, such as urea, acetoguanamine, benzoguanamine, steroganamin or spiroguanamine,

A condensate in a form obtained by reacting various aldehyde compounds, such as formaldehyde, paraformaldehyde, acetaldehyde or glyoxal, with various known and conventional methods;

Alternatively, a compound obtained by etherifying each of these condensates with alcohols may be used. Of course, any compound can be used as long as it is usually used for paints.

Of these, only typical ones are exemplified, and it is desirable to use a compound which is partially or completely etherified with alcohols of C1 to C4. If only typical representative examples of such aminoplasts are given, hexamethyletherified methylolmelamine, hexabutyletherified methylolmelamine, methylbutyl mixed etherified methylolmelamine, methyletherified methylolmelamine, butyletherified methylolmelamine or isobutyl Etherified methylolmelamine or condensates thereof;

Next, various typical aliphatic diisocyanates, such as hexamethylene diisocyanate, trimethylhexamethylene diisocyanate or isophorone diisocyanate, may be mentioned only as typical examples of the above-mentioned polyisocyanate compounds.

Various cyclic aliphatic (alicyclic) diisocyanates such as xylylene diisocyanate or isophorone diisocyanate; and various aromatic diisocyanates such as tolylene diisocyanate or 4,4'-diphenylmethane diisocyanate. Such as various organic diisocyanate compounds,

Further, an adduct of each of these organic diisocyanate compounds with a polyhydric alcohol, a low molecular weight polyester resin (polyester polyol), water, or the like, or a combination of each of the organic diisocyanate compounds described above. Polymers (including isocyanate-type polyisocyanate compounds) and isocyanates
Bullet body and the like.

Furthermore, if only typical representative examples of the above-mentioned block polyisocyanate compounds are given as examples, various polyisocyanate compounds as described above may be used in combination with ε-caprolactam, methyl ethyl ketoxime or monohydric alcohol. Such as a compound in a form that can be obtained by blocking by a conventional method using various known and commonly used blocking agents,

If only typical commercially available products of these types are to be exemplified,
"VESTANAT B-1358 / 100", "VE
STAGON B1065 or B1530 "(both are trade names of block polyisocyanate compounds manufactured by Huls, Germany) and" Cleran UI or PLS2151 "(block polyisocyanate compounds manufactured by Sumitomo Bayer Urethane Co., Ltd.) Product name)
And so on.

Further, as the polyisocyanate compound,
If only a commercial product which is particularly typical as a so-called self-block type block polyisocyanate compound having a uretdione bond in a molecule is to be exemplified, "VESTAGON B
1540 "(trade name of a compound having a uretdione bond manufactured by Huls AG, Germany).

Further, if only typical representative examples of the above-mentioned polyhydric anhydride compounds are given, only
As represented by maleic anhydride or itaconic anhydride, various, so-called acid anhydride group-containing unsaturated monomers,
Examples thereof include copolymers with various known and commonly used vinyl monomers which can be copolymerized with the acid anhydride group-containing unsaturated monomers.

In addition to such copolymers, examples of the polyhydric anhydride compounds include pyromellitic anhydride, benzophenonetetracarboxylic anhydride, ethylene glycol bis (anhydrotrimellitate) and glycerol (anhydrotrimeritate). Of course, various compounds having a relatively low molecular weight such as (hydrotrimellitate) can also be used.

A surface conditioner (c) composed of an acrylic copolymer having an ultraviolet absorbing ability, a hydroxyl group-containing polyester resin (a) and a curing agent (b) thereof, as described above, are used. In order to prepare a target powder coating using the resin composition for a powder coating according to the present invention, which comprises an essential film-forming component, various known and common methods can be used as they are. And can be applied.

That is, generally, the polyester resin (a), the curing agent (b) and the surface conditioner are mixed, and if necessary, a known material such as a pigment or a curing accelerator is mixed. A so-called mechanical pulverization method, in which various conventional additive components are mixed, melt-kneaded, and then pulverized, may be recommended because it is particularly simple.

The resin composition for a powder coating according to the present invention thus obtained, and the powder coating obtained from the resin composition for a powder coating can be prepared by various known and common methods. Electrostatic powder coating on the material, then
By being baked, the desired cured coating film,
It means that it is formed on the substrate to be coated.

Here, only typical representative examples of the above-mentioned substrate to be coated are various metals such as aluminum, stainless steel, steel, chromium plating, galvanized steel plate and tin plate. Materials or metal products; or roof tiles: glass; or various inorganic building materials,

More specifically, various kinds of building materials such as automobile bodies or automobile (for) parts; motorcycles or motorcycle (for) parts; gates or fences; aluminum sashes; And various kinds of materials and products of various ferrous and non-ferrous metals such as aluminum foil and the like.

[0055]

EXAMPLES Next, the present invention will be described specifically with reference examples, examples and comparative examples.
In no way is the invention limited to these examples. In the following, all parts and percentages are by weight unless otherwise specified.

Reference Example 1 [Preparation Example of Hydroxyl-Containing Polyester Resin (a) Used in the Present Invention] In a reaction vessel equipped with a stirrer, a thermometer, a rectification tower and a nitrogen gas inlet, 431 parts of neopentyl glycol and 35 parts of trimethylolpropane was charged, and the temperature was raised to 150 ° C. while stirring under a nitrogen atmosphere, 682 parts of terephthalic acid and 0.5 part of dibutyltin oxide were added, and the temperature was raised to 240 ° C. The temperature rose.

Thereafter, by continuing the dehydration condensation reaction at the same temperature, the hydroxyl value becomes 30 (mg KO).
H / g) and the desired polyester resin having an acid value of 4.5 was obtained. Hereinafter, polyester resin (a-
Abbreviated as 1).

Reference Example 2 (same as above) In the same reaction vessel as in Reference Example 1, 520.
5 parts, 130.1 parts of isophthalic acid, 243.1 parts of neopentyl glycol, 96.5 parts of ethylene glycol
And a mixture consisting of 9.8 parts of glycerin and 1.0 part of di-n-butyltin oxide, and
An acid value of 3 and a hydroxyl value of 2 were obtained in the same manner as in Reference Example 1 except that these raw materials were changed to be charged.
The desired polyester resin (a) having a molecular weight of 0 and a number average molecular weight of 5,000 was obtained. Hereinafter, this is referred to as (a-
Abbreviated as 2).

Reference Examples 3 to 7 (same as above) Various target hydroxyl group-containing polyester resins (a) were prepared in the same manner as in Reference Example 1 except that the starting materials shown in Table 1 were used. ) As well as various control polyester resins. Hereinafter, the names of the respective resins are as shown in the table.

In the series of Reference Examples 3 to 7, Reference Examples 3 to 5 are preparation examples of the hydroxyl group-containing polyester resin (a) to be used in the present invention. 6 and 7 are preparation examples of a polyester resin for control.

[0061]

[Table 1]

[0062]

[Table 2]

[0063]

[Table 3]

[0064]

[Table 4]

[0065]

[Table 5]

[0066]

[Table 6]

Reference Example 8 [Preparation Example of Surface Conditioning Agent (c)] In a four-necked flask equipped with a stirrer, a thermometer, a reflux condenser and a nitrogen inlet tube, 600 parts of xylene was charged and heated to 135 ° C. Warmed.

Thereafter, here, a monomer mixture as shown in Table 2 and a solution of 15 parts of azobisisobutyronitrile as a polymerization initiator in 67 parts of xylene were added, respectively. The solution was added dropwise over 5 hours, and then 100 ° C
And the polymerization reaction was carried out for 5 hours.

By removing the solvent in the copolymer solution thus obtained, the intended surface modifier (c) as an acrylic copolymer was obtained. Hereinafter, this is referred to as (c
Abbreviated as -1).

Reference Example 9 (same as above) A copolymer solution was obtained in the same manner as in Reference Example 8, except that the monomer mixture shown in Table 2 was used. Then, by removing the solvent, various surface conditioners (c), which are acrylic copolymers, were obtained. Hereinafter, the names of the respective surface conditioners are as shown in the table.

[0071]

[Table 7]

<< Footnotes to Table 2 >> * 1) Trade name of a radical polymerizable ultraviolet absorber manufactured by Otsuka Chemical Co., Ltd. as represented by the following structural formula * 2) Represented by the following structural formula Name of a hindered amine light stabilizer capable of radical polymerization manufactured by Asahi Denka Kogyo Co., Ltd.

<< Chemical Formula 1 >> * 1)

[0074]

Embedded image

<< Chemical Formula 2 >> * 2)

[0076]

Embedded image

Reference Examples 10 and 11 (same as above) A copolymer solution was prepared in the same manner as in Reference Example 8, except that a monomer mixture as shown in Table 2 was used. Then, the solvent was removed to obtain various surface conditioners (c) as acrylic copolymers. Hereinafter, the names of the respective surface conditioners are as shown in the table.

[0078]

[Table 8]

Examples 1 to 8

All of these examples show preparation examples of the resin composition for powder coating according to the present invention, that is, preparation examples of powder coating.

The various hydroxyl group-containing polyester resins (a) obtained in Reference Examples 1 to 5, the various surface preparation agents (c) obtained in Reference Examples 8 to 11, and "IPDI-addu"
ctB-1530 "(manufactured by Huls AG, Germany,
It is a trade name of a blocked isocyanate compound, where IPDI is an abbreviation for isophorone diisocyanate. ) In the proportions shown in Table 3,

Further, rutile-type titanium oxide as a pigment and di-n-butyltin dilaurate were blended in a blending ratio as shown in the same table, and after blending,
Various desired resin compositions for powder coatings were obtained by pulverizing and mixing with a Henschel mixer.

Then, using a uniaxial melt-kneading machine manufactured by Buss, Switzerland, each of the resin compositions for powder coating was mixed with 1
After melting and kneading at a temperature of 00 to 110 ° C,
After cooling, a pulverizer [Bantham Mill manufactured by Hosokawa Micron Co., Ltd.] was used. ], And passed through a 150-mesh sieve, thereby obtaining various powder coatings of interest.

Thereafter, each of these powder coatings was applied on a zinc phosphate-treated steel sheet having a thickness of 0.8 m using an electrostatic coating machine so that the film thickness became 60 μm (μm). Thereafter, baking was performed at a temperature of 180 ° C. for 20 minutes to obtain a so-called test panel in which various cured coating films were formed on various types of zinc phosphate-treated steel sheets.

The cured coating film obtained as described above was evaluated for various properties. The results are summarized in Table 4.

[0086]

[Table 9]

[0087]

[Table 10]

<< Footnotes to Table 4 >> The procedure of evaluation judgment is as follows.

Smoothness: Evaluation was visually evaluated.

60 degree gloss: Numerical evaluation judgment test based on 60 degree specular reflectance (%).

Impact resistance ·········································································· Evaluated with DuPont impact tester 50
The height (cm) at a stage where no defects such as cracks were generated in the coating film when a load of 0 g was dropped was indicated. The larger this value is, the better the impact resistance is.

Erichsen value: An evaluation judgment test using an Erichsen tester. The higher the value, the better the flexibility of the coating film.

Weather resistance: Using a sunshine weatherometer, after 1,000 hours,
The gloss retention (%) of each coating film after 1,500 hours was calculated and displayed. Note that “SWOM” in the table is
This is the abbreviation for Sunshine Weather Ometer.

Outdoor exposure: In the suburbs of Miyazaki city, sunlight is applied at an angle of 45 degrees with respect to the horizontal plane of the test panel, and extends for one year and two years, respectively. The gloss retention (%) after exposure was calculated and displayed.

[0095]

[Table 11]

[0096]

[Table 12]

[0097]

[Table 13]

[0098]

[Table 14]

Comparative Examples 1 to 3 The control hydroxyl group-containing polyester resins obtained in Reference Examples 6 and 7 were used, and "Modaflow P-III" (Monsanto, USA) was used instead of the surface preparation agent (c). Various control powder coatings were obtained in the same manner as in Examples 1 to 5, except that the change was made to use a flow control agent (trade name, manufactured by the company). Thereafter, various test panels for control were obtained in the same manner. (See Table 3)

The cured coating film obtained as described above was evaluated for various properties. The results are summarized in Table 4.

[0101]

[Table 15]

[0102]

[Table 16]

[0103]

According to the details described above,
As has been clarified, the coating film obtained using the resin composition for powder coating according to the present invention, in particular, achieves compatibility between various coating film physical properties and weather resistance without fail. Can be reasonably understood.

Therefore, it can be easily understood that the resin composition for powder coating according to the present invention is extremely practical.

Continued on the front page (51) Int.Cl. ⁶ Identification code FI C09D 175/06 C09D 175/06 // C08G 18/80 C08G 18/80

Claims (6)

[Claims] 1. A polyester resin having a hydroxyl group (a)
And a curing agent (b) having reactivity with a hydroxyl group and a surface conditioner (c) comprising an acrylic copolymer having a surface conditioner as essential components. Resin composition for paint. 2. A polyester resin having a hydroxyl group (a)
And a curing agent (b) having reactivity with a hydroxyl group, and a surface conditioner (c) made of an acrylic copolymer having a surface conditioner as essential components. (C) a powder containing the polyester resin (a) and the curing agent (b) in an amount of 1 to 15 parts by weight based on 100 parts in total. Resin composition for paint. 3. The composition according to claim 1, wherein the polyester resin having a hydroxyl group (a) has a hydroxyl value in a range of 13 to 100 mgKOH / g. 4. The at least one compound, wherein the curing agent (b) having reactivity with a hydroxyl group is selected from the group consisting of aminoplasts, blocked isocyanate compounds and polyanhydride compounds. Claim 1.
Or the composition according to 2. 5. The surface conditioner (c) is an acrylic copolymer having an ultraviolet absorbing ability, or an acrylic copolymer having both an ultraviolet absorbing ability and a light stabilizing ability. The composition according to claim 1. 6. The composition according to claim 1, wherein the surface conditioner (c) is an acrylic copolymer having a hydroxyl group.