WO2000069983A1

WO2000069983A1 - Thermosetting powder coating composition

Info

Publication number: WO2000069983A1
Application number: PCT/JP2000/003010
Authority: WO
Inventors: Nobuhiko Tsuda; Masaru Nagato; Ryoichi Fukagawa; Go Nagai; Keisuke Tano; Daisuke Tanizawa; Ryuji Iwakiri
Original assignee: Daikin Industries, Ltd.; IWAKIRI, Miyuki
Priority date: 1999-05-13
Filing date: 2000-05-11
Publication date: 2000-11-23
Also published as: JP2000319586A

Abstract

A thermosetting powder coating composition which is improved in flow properties at baking and thereby can form a smooth coating surface and give a coating which is free from surface clouding even in the early stages and excellent in gloss. This coating composition is one comprising a fluorocopolymer (A) bearing a cross-linking functional group and a curing agent (B), characterized in that the fluorocopolymer (A) contains perfluoroolefin units, has a fluorine content of 10 wt% or above, and is substantially insoluble in tetrahydrofuran, and that the curing agent (B) is a compound prepared by blocking a polyisocyanate compound modified with a polyhydric alcohol.

Description

Akira Itoda Thermosetting powder coating composition technology

The present invention relates to a thermosetting powder coating composition. More specifically, it is possible to improve the flowability of the paint at the time of baking, and to reduce the fogging of the resulting coating film, especially the initial fogging. The present invention relates to thermosetting powder coating compositions that can be used. Background technology

Powder coatings containing fluororesin are disclosed in Japanese Patent Publication No. 6-104792 and Japanese Patent Publication No.

It is known in various publications, such as No. 4111, and gives painted materials excellent in weather resistance and coating film appearance.

Further, a thermosetting powder coating composition in which an isocyanate compound is used as a curing agent in a fluorine resin containing a hydroxyl group is also known. (Japanese Patent Publication No. 6-1049472,

6-3 4 5 8 2 2 Public Bulletin, Japanese Laid-Open Patent Publication No.

As an isocyanate-based hardening agent to be used in these thermosetting fluororesin powder coatings, for example, Isophorone Sociane Compounds obtained by blocking the trimer of the target with a blocking agent such as an ε-force program or an isophorone soci Normally, linear polymer uretdione compounds derived from polyisocyanate cards such as nets are commonly used.

Toro, these general-purpose hardeners were added to tetrahydrofurano. When used for functional group-containing fluororesins that do not dissolve in THF (THF), the flowability at the time of baking is not sufficient, and the resulting coating film There are problems such as fogging on the surface.

In other words, a trimer of isophorone isocyanate is used as a stiffening agent with a blocking agent such as an ε-force program. When the compound obtained by the heat treatment is used, a low molecular weight content in the bridge and the fluorine resin produced by the curing reaction of the fluorine resin and the hardener is used. The compatibility with the fluorine polymer is poor, and the low molecular weight polymer will bleed out on the surface of the coating film during baking, and the surface of the coating film will be clouded. And

In addition, when a uretdione compound is used as a curing agent, the isophorone sorbent acts as a two-function curing agent. Therefore, the compatibility between the bridge formed by the hardening reaction of the fluorine resin and the hardener and the low molecular weight fluorine-containing polymer in the fluorine resin is good. The bridge reaction does not occur even at low temperatures because the sol- nate is not blocked, and the flowability of the coating film is sufficient at the time of baking. Not available.

The present invention provides a thermosetting fluororesin powder that imparts sufficient flowability of the coating film during baking and does not cause fogging on the surface of the baking coating film. The aim is to provide paint. Disclosure of the invention

That is, the present invention includes a fluorine-containing copolymer having a bridging functional group (Α) and a hardening agent (Β), and comprises the fluorine-containing copolymer (（). Α) contains a perfluoroolefin unit, has a fluorine content of 10% by weight or more, and has a tetrahedral opening flank. That it does not dissolve qualitatively, and that the curing agent (Β) is a polyisocyanate that has been modified with a polyhydric alcohol. The present invention relates to a thermosetting powder coating composition characterized by being a compound obtained by blocking an object with a blocking agent.

Fluorine copolymers (Α) containing bridging functional groups are from 35 to

It is preferable to have a glass transition point of 80 ° C, and it is recommended that the melt be measured at a temperature of 100 ° C and under a load of 2.1 kg. The rate (MFR) is 1 to: It is preferable that the rate is LOOOgZ10.

As the fluorine-containing copolymer containing a bridging functional group (A), tetrafluoroethylene (TFE), hexafluoropropyl pyrene (TFE) HFP), Ethylene (ET) and those containing monomer units containing bridging functional groups that can be copolymerized with them.

(Τ HE-based fluororesin) or TFE, HFP, isobutylene (IB) and a monomer unit containing a bridging functional group capable of co-polymerizing with them. It is preferable to include the resin, especially the THE fluororesin.

Preferred bridging functional groups include at least one of a hydroxyl group or an epoxy group.

,

構成 As a constituent unit of the copolymer (A), a vinylester compound unit, for example, benzoic acid vinyl unit, and / or It is preferable to introduce vinyl valinate units

硬化 As the hardener (B), a polyvalent alcohol in the hardener, although the block agent component in the hardener is an ε-force pro-tamer. The polyol component is a diole compound, and the polyisocyanate component in the curing agent is a polyisophorone sorbitan. Compounds that are preferred are preferred.

Particularly preferred combinations of the fluororesin (A) and the curing agent (B) include tetrafluoroethylene and hexafluoro. It is a copolymer of propylene, ethylene, and a monomer having a bridging functional group capable of being copolymerized with these, and containing fluorine. A fluorine-containing copolymer having a weight of 10% by weight or more and having a bridging functional group that is not practically dissolved in hot tetrahydrofuran. Block the polymer (A) and the polyisoholone isoformate denatured with the diole compound using a £ 1 force program. The resulting hardener (B) is the same.

The present invention also relates to a coated article obtained by applying the above-mentioned thermosetting powder coating composition to a substrate and baking it. Not only the best mode for carrying out the invention but also the fluorine-containing copolymer (A) having a crosslinkable functional group used in the present invention will be explained. .

The fluorine-containing copolymer containing a crosslinkable functional group (A) has at least the following properties (1) to (4).

(1) It has a unit of perfollow-refin.

For example, TRF, HFP, ZO, and ° —perfluoro liters, such as fluorovinyl ethers. At least one of the fins has been selected, and TFE and HFP are particularly preferred. By having a perfluororefin unit, a coating film having excellent weather resistance, water resistance, and stain resistance can be obtained. It is preferred that the perfluoroolefin unit be contained in the copolymer in an amount of 5 mol% or more, particularly 10 to 95 mol%.

(2) The fluorine content is 10% by weight or more.

This is the fluorine content derived from the perfluoroolefin unit or other fluorine-containing monomer, and is the same as the reason in (1) above. The reason is 10% by weight or more, preferably 20% or more. 75% by weight.

Other fluorine-containing monomers include, for example, vinyl fluoride τ, trifluoroethylene, monofluoroethylene, and chlorofluoroethylene. □ □ Trifluorofluoroethylene, etc. can be used. These other fluorine-containing monomer units are arbitrary units, and the content thereof is 30 mol% or less, usually 0 to 10 mol%.

(3) Does not substantially dissolve in THF.

Insoluble in THF results in poor compatibility with the resin soluble in THF. That is, when a powder coating using a resin that dissolves in THF is applied, and then the powder coating of the present invention is applied using the same coating line, or In the reverse order, the fluorine-containing copolymer (A) is less susceptible to the effects of other resins, and may have an effect on other powder coatings. The effect of the incorporation of the fluorine-containing copolymer (A) can be reduced.

The term “substantially insoluble” includes those that need to be dissolved in THF at a concentration of less than 0.5%. When measuring the intrinsic viscosity [? 7] of a resin in a THF solution practically, it is reliable if the solubility is not more than about 0.5% by weight. Inherent viscosity

[T)] is not possible to measure

Among resins soluble in THF, those used for powder coatings include, for example, acrylic resins, polyester resins, epoxy resins, and the like. Resin, fluorine resin, etc. described in the Japanese Patent Publication No. 6-1049472.

(4) It has a crosslinkable functional group.

The crosslinkable functional group has a function of giving a hardening site to the fluorine-containing copolymer (A), and giving a high-hardness coating film which is thermoset by reacting with the hardener. Surface hardness while maintaining good flexibility. You can raise and force S.

In the present invention, the bridging function is, for example, a chemical formula group (i):

O H, C 〇〇 H C H C H N H

O

O i S i 〇 R, C N H S 〇 H O S 0, H

(In the formula, R is an alkyl group having 13 carbon atoms.)

Even among the above-mentioned government functions, chemical formula groups (ii)

- OH, C 〇 OH, CHCH ₂ 〇 is good or Shi Le.

Monomers for introducing such bridging functional groups include, for example, perfluorobutenoic acid (PFBA), and Japanese Patent Laid-Open Publication No. In addition to the fluoromonomer having an ether unit described in the No. 5 public bulletin, it has a carilebonate group such as anhydrous maleic acid (MAL) Non-fluorinated monomer; a monomer containing a hydroxyl group such as hydroxybutyral vinyl ether (HBVE), arylyl alcohol, etc. Monomers containing epoxy groups such as Darcy Vinyl Vinyl (GVE); vinyl metoxirane, vinyl ethoxylate Monomers containing water-decomposable silyl groups described in the official gazette of JP-A No. 8-122021, and aminoproboxes Including Etc. single-mer it can Ru are examples shown.

Of these, if combined with a known hardener, firing Responsiveness in the range of the attachment temperature range PFBA, carboxyl group-containing monomer such as anhydrous maleic acid, and hydroxy such as HBVE Glycidyl group-containing monomers such as glycerol-containing monomers and GVE are preferred, and especially hydroxyl or daricidyl groups (epoxy groups). Monomers containing (S) are preferred.

The bridging functional group forms a hardened site, and its amount varies depending on the reactivity of the functional group and the type of hardening agent. The acid value is 1 to 300 mg KOH / g, or the hydroxyl value is 1 to 200 mg K 〇 HZg, or the epoxy equivalent is 5 to Preferably, it contains 150 000 equivalents.

In addition, it is preferable to have the following characteristics.

(5) The glass transition point is 35 to 80 ° C.

Within this range, even at a relatively low baking temperature, a film having excellent repelling properties and excellent appearance can be provided.

(6) MFR (measurement conditions are the same as below) when measured at 2.1 kg load and 100 to 140 ° C. ~ 100 g g Z 10 min.

MFR is a factor that is suitable for melting and kneading, baking, and especially baking. If the MFR is large, the flowability of the molten resin becomes large, and it is easy to form a smooth and uniform coating film.However, on the other hand, it is easy to produce a dull spot. In addition, when kneading, there is a drawback that the shear is not uniform and the kneading becomes difficult, and the water resistance and m-impact of the coating film are reduced. Occurs. If too small, the fluidity at the time of baking will be insufficient, and the coating film will not be smooth and uniform. The preferred MFR is between 5 and 100 g / 10 minutes.

From the above points, the unit that gives the bridging functional group is fluorine-containing unit. It may be selected within the range of 0.1 to 30 mol%, especially 1 to 20 mol% of the copolymer.

Further, when the fluorine-containing copolymer (A) contains a vinyl ester compound unit as a constituent unit, the obtained coating film may be used as a base material. The adhesion is improved, and the compatibility with a curing agent and the like is improved, so that a coating film of Takamitsuzawa can be provided. Non-fluorinated vinyl esters such as vinyl benzoate (VBz) and vinyl pivalate include vinyl ester compounds. Rile (VP i) or a mixture of these is clarified and contained in the copolymer (A) in an amount of 0.1 to 25 mol%, preferably 0.5 to 0.5 mol%. It is desirable to introduce 20 mol%.

A fluorine-containing copolymer having a bridging functional group can be obtained by copolymerizing each monomer described above. The polymerization method may be a usual polymerization method such as emulsification polymerization, suspension polymerization, or solution polymerization. In addition, a monomer having a bridging functional group in the copolymer may be subjected to a graft polymerization.

As for the fluorine-containing copolymer containing bridging functional groups of the present invention, the above-mentioned requirements (1) to (4) of the combination of monomers, for example, It is more preferable to satisfy the conditions (5) to (6). However, it is not limited to these combinations.

(I) ① Perfluoro-refin 5 mol% or more

(2) Other fluorine-containing monomers 0 to 95 mol%

③ Other non-fluorine monomer 0 to 95 mol%

Crosslinkable functional group-containing monomer 0.1 mol% or more

(I I) ① Fe / H FP

More than 5 mol% per species

(2) Other fluorine-containing monomers 0 to 95 mol% ③ Non-fluorinated olefins 0 to 95 mol%

Government function of the above-mentioned chemical formula group (i)

Monomer containing group 0.1 mol% or more

(I I I) ① T F E, H F P

Each is 10 mol% or more of each species ② Other fluorine-containing monomer 0 to 20 mol%

③Non-fluorinated olefins 10 ~ 70mol% 官 Government function of the above-mentioned group (i)

Monomer containing group 0.1 mol% or more (IV) ① Less TFE and HFP

At least 20 mol% or more per species

②Other fluorine-containing monomer 0 to 5 mol% ③Ethylene (ET) 20 to 50 mol% ④Government function of the above-mentioned group (ィ)

Group-containing monomer 0.1 mol% or more (V) ① Low in TFE and HFP

At least 20 mol% or more per species

(2) Other fluorine-containing monomer 0 to 5 mol%

③ Isobutylene (IB) 20 to 50 mol%

官 Government function of the above-mentioned chemical formula group (ii)

Group-containing monomer 0 mole% or more

(V I) ① T FE and H FP

Both 110 mol% or more

(2) Other fluorine-containing monomer 0 to 20 mol%

③ Non-fluorinated fins 10 to 70 mol.%

Government function of chemical formula group (i)

Monomer containing group 0.1 mol% or more

⑤ Vinyl ester compound 1 to 15 mol% (VI I) ① Less TFE and HFP

Both of them are more than 20 molile%

(2) Other fluorine-containing monomer 0 to 5 mol%

③ At least ET and IB

1 type 20 to 50 mol%

Government function of the chemical formula group (ii)

Monomer containing group 0.1 mol% or more

⑤ V B z and V P i

And also one kind :! More specifically, the following copolymers are to be ex- tracted, but not limited to these.

T F E Z H F P Z E T Z P F B A Copolymer (mol ratio

25 〜 40/10-20 3 5 4 8 0. 10) T F E / H F P / E T / H B V E copolymer (mol ratio

2 5 4 0 1 0-2 0 3 5 4 8 0 1 0)

T F E Z H F P Z E T Z G V E Copolymer (mol ratio. 25

~ 4 0 Z 1 0 2 0 3 5 4 8 0 0)

T F E / H F P Z E T Z H B V E Z V B z Copolymer (Mole ratio: 25 4 0 1 0 2 0 3 5 4 8 0 1 1 0/3 to 8), T F E / H F P Z E T Z H B V E

A THE-containing fluorine-containing copolymer such as a VBz / VPi copolymer (molar ratio: 25 to 4010 to 20 / 35,480,111,388); TFEZHFP / IB

/ H B VE copolymer (mol ratio. 25 to 40/10 to 20

Z35-48 / 0.1-: L0).

In addition, it is described in the official bulletin of Japanese Patent Publication No. 8 — 4 1 1 3 1

Requirement for TFE / HFP / ET copolymers without any functional groups

(4) is not satisfied, and vinylidene fluoride (Vd The fluorine-containing copolymer mainly composed of F) (Japanese Patent Publication No. 191655/35) meets the above-mentioned THF insolubility (requirement (3)). Not in .

The fluorine-containing copolymer containing a bridging functional group used in the present invention preferably has the following further physical properties.

Melting point (Tm): It is preferable that the melting point (measured by DSC) be below 160 ° C, which gives good flow characteristics during baking.

Such a crosslinkable fluorine-containing functional polymer-containing functional group imparts excellent weatherability, chemical resistance, and stain removal to the obtained coating film. In addition, the shock resistance and the bending resistance are improved.

Next, the curing agent, which is the other component of the thermosetting powder coating composition of the present invention, will be described.

The curing agent used is a compound obtained by blocking a polyisocyanate compound modified with a polyhydric alcohol with a blocking agent. It is a thing.

First of all, the polyisocyanate component is isophorone, tri-range isocyanate, Range Associate, 4,4'-G-phenylene Methane Associate, Hexa Methyl-range Associate These dimers and the like are exfoliated, and in particular, the smoothness and the weather resistance of the coating film are excellent, and the isophorone isocyanate Is preferred.

Is alcohol that denatures polyisocyanate components required multiple reaction sites in order to act as a crosslinker? Must be polyvalent alcohol. Polyvalent alcohols include, for example, 1,2—ethanediol, 1,31-propanediol, and 1,2—pronounce. Ole Or the difference between blue, yellow, hexagonal, hexagonal, and yellow. Sexual body, 1,2-six-mouthed xanthole, 1,4-six-mouthed xanthyl ^ I, 1,1,4-cyclohexene No

—, 4, 4 '1 (11-methylidene)-chemicals to the mouth of the vissik or chemicals of these jars

Reactions with lesser amounts of dicarboxylic acid or dicarboxylic acid anhydrides, such as diesters containing ester groups, can be obtained. All; Trimethyl mouth-Loop mouth or less than stoichiometric amount of dicarbonic acid or dicarbonic acid Polyols such as polyester containing polyester obtained by reacting with waterless materials can be extinguished, but especially fluorine resin and From the viewpoint of the excellent compatibility of the above, a diol, particularly, a diol containing an ester group is preferred.

As a blocking agent for blocking a polyvalent alcohol-modified polyso- lent, for example, a one-sided pro- gram. Enol, benzyl alcohol, methyl ketoxim, etc., which give a coating film with excellent smoothness. It is preferable to use the ε-power program.

In particular, when used for fluorinated fluororesin, the ester group containing ester group is preferred because of its excellent compatibility with fluororesin, excellent smoothness of coating film and weatherability. Particularly preferred is a compound obtained by blocking the isomorphous isoform, which has been altered by a small amount, with an ε-capacitive opening lactam.

In the present invention, in addition to the above-mentioned specific hardening agent (Β), it is a polymer of an isocyanate compound having a uretdione ring. Any curing agent may be used in combination.

The amount of hardener used is included in the fluorine-containing copolymer (A) It is preferred that the amount be 0.1 to 1.2 equivalents, particularly 0.5 to 1.0 equivalent, based on the amount of the functional group. If it is less than 0.1 equivalent, the effect of improving the crack resistance and impact resistance when bending by a bridge is not sufficient, and the water resistance is also low. However, if it is more than 1.2 equivalents, the appearance may be deteriorated during coating.

A curing catalyst may be combined in addition to the curing agent. Hardening catalysts include, for example, tetrabutylammonium chloride, tetrabutylammonium bromide, and tetrabutylammonium bromide. Quaternary ammonium salts such as butyl ammonium hydroxide; etc .; ethyl triphenyl ammonium phosphate; etc. Quaternary phosphine salt; phosphine, such as triphenyl phosphine; 2—imidazo, such as methylimidazole Organic tin compounds such as dibutyltin dilaurate and stannous octoate; methyltrisulfurimid, methansul For example, tin borate is required. The curing catalyst may be blended in an amount of about 0.1 to 3 parts with respect to 100 parts (weight part; hereinafter the same) of the fluorine-containing copolymer (A).

In the powder coating composition of the present invention, in addition to these additives, various kinds of additives which are usually mixed in the field of the coating material may impair the effect of the present invention. You may mix in an unsuitable amount. Such other additives include pigments, extenders, flow regulators, antioxidants, thermal degradation inhibitors, ultraviolet absorbers, foam suppressors, and foam inhibitors. (E) Adjusters, defoamers, charge control agents, antistatic agents, etc. are used.

Since the coating film formed by the fluorine-containing copolymer (A) in the present invention is transparent, various kinds of pigments can be used. it can . For example, condensed azo compounds, isoindolinones, quinacridones, dike pyrrolopyrroles, antracaki Organic pigments such as non-, oxazine, and various metal-organic complexes; titanium oxides (preferably in the form of aluminum, more preferably in the form of aluminum Oxidized titanium that has been treated with U-force or zirconia is preferred), red iron oxide, yellow iron oxide, black iron oxide, Boron, oxidized chromium, lead chromate, graphite, molybdenum oren, zinc oxide, antimony oxide, oxidized iron oxide, oxidized magnesium Inorganic cosmetics such as single or multiple oxides such as magnesium, aluminum oxide, nickel oxide; aluminum powder, steel Metal powders such as stainless steel powders are required. Among these, the resin retains light and suppresses fading even in the weather resistance, which is a characteristic of this resin: inorganic paints are preferred, and good pigment concentration is preferred. Is preferably not more than 80 parts with respect to 100 parts of resin.

Also, as a facial composition, for example, evening silk, silica, calcium carbonate, barium sulfate, myrgic, keratinous soil, and asbestos , Basic silicates, etc.

Examples of the flow regulator include polyacrylic acrylate, polyacrylic acrylate, polyethyl acrylate, and polyacrylic acrylate. Acrylate ester polymers such as polyester; polyester and perfluorocarboxylic acid esters and Vd

Fluoropolymers containing low melting point such as F / TFE / UFP copolymers (excluding VdF-based polymers containing bridging functional groups); polymethylsilyl It can be used for X-cone polymers such as xan, polymethylsiloxyxan, etc.

Next, the method for preparing the powder coating composition of the present invention will be described. However, the composition of the present invention is characterized in that it is difficult to be mixed with other coating resins. It also has excellent properties.

The process consists of a pre-grinding process, a dry blending process, and a melting process. It consists of a melting and kneading process, a pulverizing process and a classification process.

(Preliminary crushing process)

As described above, the fluorine-containing copolymer containing a bridging functional group can be obtained in various forms such as powder, flake, and valley. . To improve mixing in the drive end process of the next process, form a pellet of 5 mm or less or about 50% or less. Grind to an average particle size of ~ 100 m.

(Dry blend process)

The above-mentioned additives such as powdery or pellet-like crosslinkable functional group-containing fluorine-containing copolymers, hardeners, hardening catalysts, and other pigments Drive. The mixers used are generally high-speed mixers, low-speed mixers, and hen-shell mixers. If the temperature inside the mixer rises too high at this time, the reaction between the bridging functional group and the hardener proceeds, and the temperature of the mixer increases over time. Due to the control, it is preferable to keep the temperature in the mixer at about 80 ° C or less.

(Melting and kneading process)

The above-mentioned dry blend is put into a melt kneading machine and melted at a melting point of the fluorine-containing copolymer (A) or above the glass transition point (Tg) or higher. The mixture is extruded in a sheet form. In this case, a continuous relay with high productivity is preferably used. As the melting and kneading machine, a single-screw extruder and kneader, a twin-screw extruder and kneader, a heating kneader, a heating roll, and the like are generally used. Melt kneading is carried out at a temperature of 80 to 120 ° C and usually for several tens of hours so that the reaction between the functional groups in the resin and the hardener does not proceed too much. Seconds.

(Crushing process)

The sheet extruded and melted into the specified shape was cooled and solidified. After that, it is roughly crushed into a chip of about 5 to 15 mm and then finely crushed. In this case, it is preferable to maintain the crusher at a constant temperature by means of extremely low temperature crushing, air cooling, or water cooling. Pulverizers such as a high-speed impact type pulverizer and a high-speed pin type pulverizer are preferably used.

(Classification process)

The powder obtained by pulverization is classified using a centrifugal classifier, a blower type sieve or a vibrating sieve. The narrower the particle size distribution, the better. The average particle size of the powder coating composition is preferably from 1 to 100 m, particularly preferably from 10 to 50 m. If the particle size is less than lm, the particles are subject to electrostatic repulsion, making it difficult to control the coating film thickness.In addition, collection by recycling at the time of recovery and reuse Problems such as low efficiency of coating due to low efficiency and reduction of safety workability due to penetration of protective mask will occur. If it exceeds 100 ^ m, there arises a problem that the repelling property is deteriorated, the coating film appearance is inferior, and the thin coating cannot be performed. The average particle size is determined by the thickness of the target coating film. For example, if the film thickness is approximately 40 to 50 Atm, the average particle size is 25 to A value of 30 um is preferred. The smaller the average particle size, the better the appearance of the coating and the possibility of thin coating.However, the workability due to clogging during spray coating is increased. With the decrease, the paint adhesion rate also decreases.

In this way, the thermosetting powder coating composition of the present invention can be prepared.

The thermosetting powder coating composition of the present invention can be applied to various kinds of base materials by a conventionally known coating method, and then obtained by baking treatment. The coating film has an appearance such as smoothness of the coating film, surface hardness, mechanical characteristics such as flexibility and impact resistance, and adhesion to the substrate. It has excellent properties such as heat resistance, weather resistance, stain resistance, and water resistance.Especially, the surface of the coating film after baking has little fogging and excellent light emission. can get .

That is, the present invention also relates to a coated material obtained by applying the thermosetting powder coating composition to a base material and then baking and hardening the composition.

As the coating method, a conventionally known method can be used. At the time of this baking, the composition of the present invention has a good flow property at the time of baking of the coating film, as described above.

As a coating method, for example, an electrostatic powder spraying method, a fluid immersion method, and an electrostatic flow immersion method are used. The coating thickness is usually in the range of 20 to 100 x m.

Then bake the paint film. The baking temperature is below 200 ° C., usually above 150 ° C., preferably between 160 and 200 ° C. The baking time is between 10 and 30 minutes, usually between 15 and 20 minutes. The powder coating composition of the present invention exhibits excellent flowability at this baking temperature, and gives a smooth and uniform baking coating film.

The powder coating composition of the present invention is also excellent in adhesion to a substrate. The substrate is preferably electrically conductive in order to allow for electrostatic painting. The base material may be various metals such as stainless steel, aluminum, steel plate, zinc-treated steel plate, etc. Polycarbonate, polyphenylene oxide, polyethylene tereffe with electrical conductivity added by dispersing the electric power Heat-resistant engineers such as turrets, polyether sulfones, polyamide imids, and polyethertelketones It can also be used to make long plastic sticks. These substrates can be used to remove 、 by sand blasting, acid cleaning, etc., bake, bum, solvent wash, emulsifier Degreasing with ion cleaners, alkaline, etc., zinc phosphite, zinc phosphite calcium, iron phosphite, etc. Chemical treatments such as acid salt treatment, chromic acid salt treatment, aluminite treatment, chromate treatment, and chromic acid phosphate treatment are performed. This is preferred. At this time, the coating composition of the present invention alone has a sufficient adhesion to these base materials by itself, but depending on the purpose, it can be used as a paint filler. It is also possible to use a combination of various primers such as primers, epoxy resin, and acrylic resin. These middle coats may be applied in any form such as a solvent-based paint, a water-based paint, or a powder paint, but the workability of the present invention is not affected. If considered, it is preferable to apply it in the form of a powder coating.

In addition, the painted material of the present invention is used for various purposes, and includes civil engineering construction materials, electric communication devices, vehicles, road materials, waterways and gas materials, Metal products, household goods, machinery, tools, instruments, medical care, security equipment, agricultural materials, ships, sports registrars, etc. Application Guide for Body Coatings ", Japan Powder Coatings Industry Association (1994), pp. 169-173, pp. 169-173. What you can do.

In the following, the present invention will be described more specifically on the basis of embodiments, but the present invention is not limited to only these examples.

Synthesis example 1

Pour 100 ml of deionized water into a pressure-resistant reaction vessel with a stirrer with a capacity of 4 liters, repeat nitrogen injection and degassing, and dissolve dissolved oxygen. After removal of, 507 g of chlorofluoroethylene (HCFC-141b) and hydroxybutyryl vinyl ether (HBVE) 3. LG, Hexa-flexio mouth proppan (HFP) 340 g was sequentially charged. Tetrafluoroethylene (TFE) 8.7 kgf at 35 ° C, based on a mixed monomer with a ratio of 82/18 mole% of Z ethylene (ET). / cm ² . Then 3 g of cyclohexane and 23 g of a 25% solution of isochlorobutyrolpaxide in dichlorotetrafluoropropane (HCFC-22). The mixed monomer is continuously supplied so that the inside pressure of the tank is constant at 8.7 kgf Z cm ² , and the isobutane is supplied every three hours from the start of the reaction. The reaction was carried out for 8 hours while purging twice with 11.5 g of a 25% solution of HCFC-225 of lilpoxide, and then the inside of the tank was cooled. The temperature was returned to normal temperature and normal pressure, and the reaction was completed. The obtained solid is washed, dehydrated, and dried in a vacuum at 80 ° C to obtain a TFEZHFP / ETZHBVE copolymer (white colored powder).

120 g was obtained. The polymer composition of this fluorine-containing copolymer is TFEZHFPZETZHBVE = 32/13/46 X9 (mol%), and the glass transition point (T g), MFR and The solubility of THF and THF was measured by the method shown below, and it was found to be "insoluble" at 40 ° C and 80 g / 10 minutes, respectively.

Glass transition point: 10 mg of VdF-based polymer was added at 25 to 200 ° C using Therma 1 Ana 1 sis System (manufactured by Parkin Elmer). The heat balance was measured at a heating rate of 10 ° C / min in the above temperature range, and the peak was taken as the melting point. Since the glass transition point is detected as two inflection points, the midpoint method was used. MFR: Measured under the conditions of 140 ° C, 2.1 kg load, 10 minutes, and 230 ° C, 2.1 kg load, 10 minutes. THF Solubility: Add 0.5 g of powdery resin at room temperature to 10 ml of THF, and let stand for 72 hours. Observed.

Example 1

100 g of a fluorine-containing copolymer containing a bridging functional group obtained in Synthesis Example 1 and Clelan cross-linking agent UI

(A bio-modified isophorone isoform manufactured by Sumitomo Bayer Urethane Co., Ltd. is analyzed using an ε-force program. Hardened curing agent) 40 g, titanium oxide 45 g, flow modifier (Moda Flow Powder 2000, manufactured by Monsanto) 3. Dry 5 g and 1.2 g of benzoin with a Henschel mixer at 25 ° C for 15 minutes and mix evenly I got something. This mixture is melted and kneaded at 100 ° C for 1 minute with a Bus Conider (Bus Co., Ltd.), extruded in a sheet form, and then coarsely crushed. did . This coarse powder is finely pulverized for 5 minutes at room temperature (approximately 20 T) at a room temperature (approximately 20 T) with Microno and Nima Milli (made by IKA). The mixture was classified through a slush screen to obtain a powder coating composition having an average particle size of 30 im.

The powder coating composition was applied to a 0.3 mm thick JIS 200 A3114-treated aluminum plate using a corona-type powder coating gun (Onoda, Japan). GX330 (Cement Co., Ltd.) was applied at an applied voltage of 60 kV, and immediately baked at 180 ° C for 20 minutes. (Coating thickness: 75 Xm).

The appearance of this painted product was visually observed, and the following coating film characteristics were examined. The results are shown in Table 1.

(Thickness of coating film)

It is measured using an eddy current film thickness meter EL10D (manufactured by SANKO CORPORATION, Electronic Research Laboratories).

(Coating appearance) When the fluorescent lamp is transferred to a painted object and viewed, the shape of the fluorescent lamp reflected on the surface of the coating film is visually evaluated.

A: There is no distortion.

B: There is some wrinkling.

C: You are working very hard.

(Mitsuzawa)

The degree of specular gloss at 60 degrees of the coating film immediately after baking and after removing the fogging can be determined according to JIS K540-6.7. To remove the fogging, wet the surface of the coating with acetone, and then wipe it off gently with a cloth.

( Pencil hardness )

Check the hardness of the lead brush according to JIS K540. (Impact resistance)

After performing the ball drop test in accordance with A A M A605, perform the tape peeling test and evaluate according to the following criteria.

〇: Cracked on the coating film, no peeling was observed.

X: Cracking or peeling is observed on the coating film.

(Flexibility)

Perform the bending test according to A A M A605. (Adhesiveness)

It can be checked by the gonon test according to A A M A 605.

(Boiling water resistance)

The adhesion after a boiling water immersion test in accordance with A A M A 605 was examined.

(Stain resistance)

Apply oil-based ink (red) to the coating plate, leave it at room temperature for 24 hours, then wipe it off with a cloth soaked with ethanol, and before and after the test. Is evaluated according to the following criteria. A: ΔE is less than 1

B: ΔE is 1 or more and less than 5

C: ΔE is 5 or more

( Weatherability )

Example 2 of examining the retention rate of light after 2 000 hours by using an accelerated weathering tester (Sannonya za omeome). And Comparative Examples 1 to A

As shown in Table 1, except that the curing agent was changed, a powder A daytime coating composition was obtained in the same manner as in Example 1. The amount of the hardening agent () (g) is the amount based on 100 g of the fluorine resin.

These powder coating compositions are applied to a 0.3 mm thick JIS 2003 A7 14 chemical conversion aluminum plate with a corona-type powder coating gun (small). Using Noda Cement Co., Ltd.'s GX3300) with an applied voltage of 60 kV, the paint was applied immediately. After baking for 20 minutes at C, a coated product (film thickness 75 ^ m) was obtained.

The characteristics of the obtained painted product were examined in the same manner as in Example 1. The results are shown in Table 1. A comparative example

The accelerated weathering test in 4 was performed after removing the fog on the surface of the coating film.

The hardeners in Table 1 are of the respective types.

6 Base Β Β ： 0 6 6 6 を 6 6 6 6 6 をををををををををををThe compound blocked in the evening.

Clelan VΡLS2256: A hardening agent manufactured by Sumitomo Bayer Urethane Co., Ltd. A compound obtained by blocking the trimer of the isophorone isocynate with an ε-force program.

Vestagon 5 153: Hardening agent manufactured by Huels. Ε-force pro-lactone OAVo69 / lio ijf / lud-

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Table 1 Example Comparative example

1 2 1 2 3 4 Curing agent (g)

Cleran Cross Linking Agent UI 40 ― ― ― 1 ― Vesu Gon B 1065 1 44 1 ― 1 1 Cleran VPLS 2256 1 1 31 1 ― 1 Ves Gon B 1 530 ― ― 1 31 ― ― Clelan VPL S 2 147 ― 1 1 1 1 1 3 4 ― Base glass 1 3 1 0 ― 1 1 1 ― 3 3 Appearance AAAABB Gloss Immediately after baking 60 62 25 27 22 25 After fogging removal 61 62 58 60 23 25 Pencil hardness HHHHHH film Impact resistance 〇〇〇〇〇〇 Object Flexible 1 T 1 T 1 T 1 T 1 T 1 T

Adhesion 100/100 100/100 100/100 100/100 100/100 100/100 Boiling water resistant 100/100 100/100 100/100 100/100 100/100 100/100 Metacontamination AAAAAA Weather resistance 97 98 98 98 98 98

Industrial availability

When the powder coating composition of the present invention is used, the flowability of the coating at the time of baking of the coating is improved, and the smooth coating surface is formed. When possible, the surface of the resulting coating film is provided with a coating film that is not cloudy from the beginning and has excellent gloss.

Claims

Scope of demand

1. It contains a fluorine-containing copolymer (A) having a crosslinkable functional group and a hardening agent (B), and the fluorine-containing copolymer (A) is a perfume. It contains an orthoolefin unit, has a fluorine content of 10% by weight or more, and does not substantially dissolve in tetrahydrofuran. And the curing agent (B) is obtained by blocking a polyisocyanate compound modified with a polyhydric alcohol with a blocking agent. A thermosetting powder coating composition characterized by being a compound.

2. The thermosetting powder coating material according to claim 1, wherein the glass transition point of the fluorine-containing copolymer (A) having a crosslinkable functional group is from 35 to 80. Composition.

3. The fluorine-containing copolymer (A) having a crosslinkable functional group is made of tetrafluoroethylene, hexafluoropropylene, ethylene and ethylene. Claim 1 or Claim 2 which is a copolymer of a crosslinkable functional group-containing monomer copolymerizable therewith.

3. The thermosetting powder coating composition according to item 2.

4. Fluorine-containing copolymer (A) having a crosslinkable functional group can be used for tetrafluoroethylene, hexafluoropropylene, and isobutylene. The thermosetting powder coating composition according to claim 1 or 2, wherein the thermosetting powder coating composition is a copolymer of a crosslinkable functional group-containing monomer copolymerizable therewith. .

5. The heat treatment according to any one of claims 1 to 4, wherein the crosslinkable functional group is at least one kind of a hydroxyl group or an epoxy group. Curable powder coating composition.

6. Any one of claims 1 to 5 wherein the fluorine-containing copolymer (A) further comprises a vinyl ester compound unit. 11. The thermosetting powder coating composition according to item 1.

Claim 6 wherein the unit of vinyl ester compound is vinyl benzoate unit and / or vinyl pivalate unit. The thermosetting powder coating composition described above.

The block agent component in the hardener (B) is an ε-force pro-tamer. The heat described in any one of paragraphs 1 to 7 of the claim. Curable powder coating composition.

The thermosetting powder as described in paragraph (1) or (8) of the claim, in which the polyhydric alcohol component in the hardener (Β) is a diol compound. Body paint composition.

Claims 1, 2, and 3, wherein the polyisocyanate component in the stiffening agent (Β) is a polyisophorone isocyanate. The thermosetting powder coating composition according to any one of paragraphs 8 or 9.

A coated article obtained by applying the thermosetting powder coating composition described in any one of paragraphs 1 to 10 to a base material and baking it.