JPH04292677A - Coating composition - Google Patents

Abstract

PURPOSE:To obtain a coating composition containing a polyol resin, functional fluororesin, specific binder, inorganic organosol and solvent and having excellent weather resistance and simultaneously improved surface hardness. CONSTITUTION:A coating composition containing (A) a polyester resin and/or a polyol resin consisting of a polyol acrylate resin, (B) a functional fluororesin, (C) a binder consisting of an isocyanate compound, blocked isocyanate compound and/or melamine compound having >=2 functional groups, (D) a metal oxide sol (salt) consisting of a metal of the group II to VIII in periodic table of long- period type and an inorganic organosol consisting a (metalo)siloxane and/or a (metalo)silazane and (E) a solvent such as xylene or toluene, having excellent scratch resistance and stainproof property and useful for building, engineering work and household appliance fields and transportation and vehicle field, etc.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coating composition having excellent weather resistance and scratch resistance.

The coating composition of the present invention can be applied to inorganic materials (steel plates, aluminum plates, glass, tiles, slate boards, etc.) and organic materials (wood, paper, cellophane, plastics, organic paint films, etc.).
Useful as a paint or coating agent for surfaces.

[0003] The steel sheets targeted in the present invention include, for example, hot-rolled steel sheets, cold-rolled steel sheets, electrogalvanized steel sheets, hot-dip galvanized steel sheets, alloy-plated steel sheets, or those treated with chemical conversion treatment such as chromic acid or phosphoric acid. It is also made of tin plate, chin-free steel, stainless steel plate, etc.

[0004] Particularly in the fields of home appliances, architecture and civil engineering (buildings,
It is useful in the fields of housing, curtain walls, tanks, plants, offshore structures, bridges, etc.), transportation vehicles (automobiles, train cars, aircraft, etc.), etc.

[0005]

BACKGROUND OF THE INVENTION Conventionally, polyester resins, acrylic resins (including acrylic silicone resins), or mixtures of two or more of these resins have been used as paint resins with good processability.

[0006]

[Problems to be Solved by the Invention] Conventionally used paint resins with good workability have a problem of being easily scratched and worn due to their low hardness. In addition, since it has low weather resistance, it has the disadvantage of being prone to discoloration, cracks, rust, chalking, etc. when exposed outdoors for a long time.

[0007]

[Means for Solving the Problems] As a result of intensive research in order to solve the above problems, the present inventors have developed a solution containing a polyol resin, a functional fluororesin, a binder, an inorganic organosol, and a solvent. After applying the composition to the base material, when the composition is cured at room temperature or baked, fluororesin and inorganic organosol are introduced into the polyol resin via a binder, resulting in a coating with improved weather resistance and hardness compared to polyol resin. The present invention was completed based on the discovery that the following was formed.

That is, the present invention is comprised of one or more polyol resins (A) selected from polyester resins and acrylic polyol resins, a functional fluororesin (B), an isocyanate having two or more functional groups, a blocked isocyanate, and a melamine. one or more selected binders (C);
Group II metals (Mg,
Group III metals (B, Al, Ga)
, In, Tl, Sc, Y, La, Ac), group IV metals (
Si, Ge, Sn, Pb, Ti, Zr, Hf), Group V metals (As, Sb, Bi, V, Nb, Ta), Group VI metals (Te, Po, Cr, Mo, W), Group VII metals (A
t, Mn, Tc, Re) and group VIII metals (Fe, C
one or more metal oxide sols selected from metal oxide sol and salts of metal oxide sol, siloxane, metallosiloxane, silazane, metallosilazane, and mixtures thereof; The present invention provides a coating composition containing an inorganic organosol (D) and a solvent (E).

[0009] The polyol resin (A
) include polyester resins, acrylic polyol resins, and mixtures thereof. Examples of polyester resins include phthalic acid, isophthalic acid,
Polybasic acids such as terephthalic acid, maleic acid, fumaric acid, succinic acid, adipic acid, sebacic acid, azelaic acid, trimellitic acid, etc. and ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, neopentyl glycol, hexamethylene glycol, decamethylene glycol, hydroquinone bis(hydroxyethyl ether), 2,2,4-trimethyl-1,3-pentanediol, water Added bisphenol A, trimethylolethane,
Obtained by condensing polyols such as trimethylolpropane, hexanetriol, glycerin, pentaerythritol, tris(hydroxyethyl)isocyanurate, cyclohexanediol, cyclohexanedimethanol, xylylene glycol, and quadrol using a conventional method under conditions with an excess of hydroxyl groups. It will be done. In this case, it is also possible to use two or more types of acids or polyols in combination. Also, castor oil, higher fatty acids, etc. may be used in combination to form a so-called oil-modified polyester polyol.

[0010] The polyester resin obtained by combining the above raw materials has a molecular weight of about 500 to 300,000.
, preferably about 2,000 to 100,000, and a hydroxyl value of about 5 to 300, preferably about 10 to 200. Examples of the acrylic polyol resin include (1) 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, allyl alcohol, cinnamon alcohol, crotonyl alcohol, or, for example, acrylic acid, unsaturated carboxylic acids such as methacrylic acid, maleic acid, fumaric acid, crotonic acid, itaconic acid, etc. and unsaturated carboxylic acids such as ethylene glycol, ethylene oxide, propylene glycol, propylene oxide, butylene glycol, 1,4-cyclohexyl dimethanol, phenyl glycidyl ether , glycidyl decanoate, etc., and (2) a hydroxyl group-containing monomer, such as methyl acrylate,
Ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, t acrylate
Acrylic esters such as ert-butyl, 2-ethylhexyl acrylate, methyl methacrylate,
Methacrylic acid esters such as ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, tert-butyl methacrylate, and 2-ethylhexyl methacrylate, such as styrene, vinyltoluene, α-methylstyrene, etc. Styrenic monomers; other acrylic acid, methacrylic acid, vinyl acetate, vinyl propionate, acrylonitrile, vinyl stearate, allyl acetate, diallyl adipate, dimethyl itaconate, diethyl maleate, vinyl chloride, vinylidene chloride, ethylene, methacrylate Obtained by copolymerizing one or more copolymerizable α, β-ethylenically unsaturated monomers such as glycidyl acid, N-methylolacrylamide, N-butoxymethylacrylamide, acrylamide, diacetone acrylamide, etc. What can be given can be given.

The acrylic polyol resin obtained by combining the above raw materials has a molecular weight of about 1,000 to 500.
,000, preferably about 5,000 to 100,00
0, hydroxyl value about 5-300, preferably about 10-300
200 is preferably used.

Examples of commercially available polyester resins include "Desmophen 670, 680, 850" manufactured by Sumitomo Bayer Urethane Co., Ltd., and "Burnock D161, D6" manufactured by Dainippon Ink and Chemicals Co., Ltd.
-439, D220'', and ``Nipporan 136'' manufactured by Nippon Polyurethane Industries, Ltd., and the like. Also,
As a commercially available acrylic polyol resin, for example, "Alotane UW281" manufactured by Nippon Shokubai Chemical Industry Co., Ltd.
8”, “Acridic A801, A811, A808” manufactured by Dainippon Ink and Chemicals, Ltd., Hitachi Chemical (
“Hitaroid 2462A, 2405” manufactured by Sumitomo Bayer Urethane Co., Ltd., “Desmophen A160,” manufactured by Sumitomo Bayer Urethane Co., Ltd.
A165, A260'', etc.

[0013] The functional group in the functional fluororesin used in the present invention may include a hydroxyl group, a carboxyl group, an amino group, etc., but a hydroxyl group is particularly preferred. Therefore, the functional fluororesin (B) includes a binary copolymer of a fluorine-containing vinyl monomer and a functional group-containing vinyl monomer, a fluorine-containing vinyl monomer, a functional group-containing vinyl monomer, and other copolymerizable vinyl monomers. A tertiary copolymer made of monomers can be used.

Examples of the fluorine-containing vinyl monomer include vinyl fluoride, vinylidene fluoride, trifluoroethylene, tetrafluoroethylene, bromotrifluoroethylene,
Examples include chlorotrifluoroethylene, pentafluoropropylene, hexafluoropropylene, (per)fluoroalkyl trifluorovinyl ether, and the like. Particularly preferred are those having a large proportion of fluorine atoms in the molecule.

Among the functional group-containing vinyl monomers, the hydroxyl group-containing vinyl monomers include hydroxyalkyl vinyl ethers such as hydroxyethyl vinyl ether, hydroxypropyl vinyl ether, and hydroxybutyl vinyl ether; 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl acrylate, Examples include hydroxyalkyl (meth)acrylates such as diethylene glycol mono(meth)acrylate. Examples of carboxyl group-containing vinyl monomers include acrylic acid,
Examples include methacrylic acid, maleic acid, maleic anhydride, itaconic acid, itaconic anhydride, and fumaric acid. Examples of the amino group-containing vinyl monomer include dimethylaminoethyl vinyl ether, dimethylaminopropyl vinyl ether, N,N-dimethylaminopropyl (meth)acrylamide, dimethylaminoethyl (meth)acrylate, and the like.

Other copolymerizable vinyl monomers include ethyl vinyl ether, n-butyl vinyl ether,
Alkyl vinyl ethers such as isobutyl vinyl ether and cyclohexyl vinyl ether; vinyl acetate, vinyl propionate, vinyl butyrate, vinyl pivalate, vinyl caproate, vinyl caprate, vinyl caprylate,
Vinyl esters of linear or branched aliphatic carboxylic acids such as vinyl versatate, vinyl laurate, and vinyl stearate; vinyl esters of alicyclic carboxylic acids such as vinyl cyclohexanecarboxylate; vinyl benzoate esters , pt-butylbenzoic acid vinyl ester, aromatic carboxylic acid vinyl ester such as salicylic acid vinyl ester; vinyl monomers having epoxy groups such as glycidyl vinyl ether, glycidyl methacrylate; acrylic acid, methacrylic acid, maleic acid,
Vinyl monomers containing carboxyl groups such as maleic anhydride, itaconic acid, itaconic anhydride, fumaric acid, monoethyl maleate, monobutyl maleate, monobutyl fumarate, monobutyl itaconate, monovinyl adipate, monovinyl sebacate; dimethylaminoethyl vinyl ether, dimethylaminopropyl vinyl ether,
Vinyl monomers containing amino groups such as N,N-dimethylaminopropyl (meth)acrylamide and dimethylaminoethyl (meth)acrylate; Halogen-containing vinyl monomers excluding fluorine such as vinyl chloride and vinylidene chloride; styrene, α-methyl Aromatic vinyl monomers such as styrene, vinyltoluene, vinylpyridine; methyl (meth)acrylate, ethyl (meth)acrylate,
(meth)acrylic acid esters such as butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, lauryl (meth)acrylate, cyclohexyl (meth)acrylate, β-hydroxyethyl (meth)acrylate; (meth)acrylonitrile, (meth)acrylate; ) acrylamide, N-methylol (meth)acrylamide, N-
Examples include butoxymethyl (meth)acrylamide, maleic acid diamide, and the like.

Two or more of the fluorine-containing vinyl monomers, functional group-containing vinyl monomers, and copolymerizable vinyl monomers may be used in combination.

Examples of fluororesins that can be used commercially include "Lumiflon" manufactured by Asahi Glass Co., Ltd., "Cepural Coat" manufactured by Central Glass Co., Ltd., "Fluonate" manufactured by Dainippon Ink and Chemicals Co., Ltd., and the United States. Examples include "Kyner" manufactured by Pennwalt, "Neoflon" manufactured by Daikin Industries, Ltd., and "Vidal" manufactured by Hoechst of West Germany.

The binder (C) is selected from isocyanate compounds having two or more functional groups, blocked isocyanate compounds, and melamine compounds. These alone,
Alternatively, two or more types can be mixed and added to the functional fluororesin.

[0020] As the isocyanate compound, aliphatic,
Alicyclic, aromatic, and other polyisocyanate compounds and modified products thereof may be used. However, the weather resistance of the coating film,
In particular, in order to prevent yellowing, so-called non-yellowing polyisocyanate compounds that do not contain isocyanate groups directly bonded to aromatic nuclei are preferred. Non-yellowing polyisocyanate compounds include, for example, hexamethylene diisocyanate, 1,4-cyclohexane bis(methyl isocyanate), methylene bis(cyclohexyl isocyanate), cyclohexylmethane diisocyanate, isophorone diisocyanate, 2-isocyanate ethyl 2,6-diisocyanate hexanoate. ate, 2,6-diisocyanate methyl caproate, dimeryl diisocyanate, dianisidine diisocyanate, cyanuric acid, isocyanuric acid, and modified products thereof. Examples of modified products include trimer type, dimer type, prepolymer type, biuret type, urea type, and other modified types.In particular, trimer type, prepolymer type such as trimethylolpropane modified, biuret type, etc. Modified products are suitable. In some cases, aromatic yellowing polyisocyanate compounds may be used in place of or in addition to these non-yellowing polyisocyanate compounds.

[0021] In this specification, the term "blocked isocyanate compound" refers to a blocked isocyanate compound that can be deblocked under the following curing conditions to produce an isocyanate group, and can be produced by blocking the above polyisocyanate compound. Can be done. The blocking agent used for this blocking can be appropriately selected from various known blocking agents depending on the application and curing conditions. For example, lactam blocking agents such as ε-caprolactam, acetoxime, methyl ethyl ketoxime, methyl isoamyl ketoxime, methyl isobutyl ketoxime, other oxime blocking agents, phenol, cresol, catechol, nitrophenol, and other phenolic blocks. blocking agents, isopropanol, trimethylolpropane, other alcohol-based blocking agents, malonic acid esters,
Examples include, but are not limited to, acetoacetate and other active methylene blocking agents. Preferred blocking agents are, for example, lactam blocking agents and oxime blocking agents.

Generally, it is preferable to contain an isocyanate compound when the composition is used as a room temperature curable hard coat composition, and a blocked isocyanate compound when used as a bake-on hard coat composition. However, it may contain a combination of two or more types of binders.

Commercially available isocyanate type binders include, for example, "Coronate 2515" manufactured by Nippon Polyurethane Industries, Ltd., and "Coronate 2515" manufactured by Sumitomo Bayer Urethane Co., Ltd.
"Desmodule BL3175" and the like.

Examples of the melamine compound include dimethylolmelamine, trimethylolmelamine, tetramethylolmelamine, pentamethylolmelamine, hexamethylolmelamine, isobutyl ether type melamine, n-butyl ether type melamine, and butylated benzoguanamine.

As for the inorganic organosol (D), the metal is group II in the periodic table of long-period elements (Mg, Ca,
Sr, Ba), III group (B, Al, Ga, In, T
l, Sc, Y, La, Ac), IV group (Si, Ge, S
n, Pb, Ti, Zr, Hf), V group (As, Sb, B
i, V, Nb, Ta), VI group (Te, Po, Cr, M
o, W), group VII (At, Mn, Tc, Re) and group VIII (Fe, Co, Ni, Ru, Rh, Pd, O
One or more inorganic organosols selected from metal oxide sols selected from metals (S, Ir, Pt), salts of metal oxide sol, siloxanes, metallosiloxanes, silazane, metallosilazanes, and mixtures thereof are used. In the preferred inorganic organosol (D), the metal is a group III group in the periodic table of long-period elements (B, Al, Ga,
In, Tl, Sc, Y, La, Ac), IV group (Si,
Ge, Sn, Pb, Ti, Zr, Hf) and group V (As
, Sb, Bi, V, Nb, Ta), particularly preferably when the metal is Si, Al
, Sn, Ti and Zr. Note that the salt of metal oxide sol refers to the salt of metal oxide sol and cations (Li+, K+, Na+, Mg2+
, Zn2+, Al3+, Ca2+, etc.) or anions (S2-, PO43-, SO4 2-, CH3
COO − , NO3 − , Cl − , F − , etc.).

Polyol resin (A), functional fluororesin (B), binder (C), and inorganic organosol (D
) The blending ratio of (A) is 10 to 80% by weight,
(B) 2-80%, (C) 2-50%, and (D)
It is preferably 5 to 60%, more preferably,
(A) 20-60%, (B) 5-60%, (C) 5
-30%, and (D) 10-50%.

[0027] As the solvent (E), a suitable amount of a solvent capable of dissolving each of the above ingredients may be used. In particular, organic solvents with high solubility in the functional fluororesin (B) and the inorganic organosol (D) are suitable, such as xylene, toluene, other aromatic hydrocarbon solvents, butyl acetate, and other ester-based solvents. Solvents include methyl isobutyl ketone, cyclohexanone, other ketone solvents, ethyl cellosolve, other glycol ether solvents, carbitol acetate, other diethylene glycol ester solvents, and various thinners. Of course, the solvent is not limited to these, and other hydrocarbon-based, halogenated hydrocarbon-based, alcohol-based, phenol-based, acetal-based, ester-based, ether-based, ketone-based, and other solvents may be used. These solvents can be appropriately selected in consideration of the type and condition of the object to be coated, evaporation rate, working environment, and other conditions, but ketone solvents are particularly preferred since they provide a particularly good coating film.

The composition of the present invention preferably contains a catalyst (F) for accelerating the reaction, since curing is accelerated and workability is improved.

As the catalyst (F), a basic or acidic curing catalyst can be used. Typical basic catalysts include dibutyltin dilaurate, dibutyltin diacetate, stannath octoate, other organotin compounds, methylimidazole, acridine, triethylamine, hexadecyltrimethylammonium stearate, and other amine catalysts. It is a chemical compound. Typical examples of acidic catalysts include organic sulfonic acids such as methanesulfonic acid, dodecylbenzenesulfonic acid, and toluenesulfonic acid. As the catalyst (F), at least one of these basic catalysts and acidic catalysts is used, but a promoter or the like may also be used in combination.

The coating composition of the present invention contains the above (A)
In addition to the essential components (E) to (E) and the catalyst (F), other components may be optionally blended depending on the purpose. For example, when used as a paint, a pigment (G) can be added as necessary.

Pigments (G) include yellow lead, molybdate orange, navy blue, cadmium pigments, titanium white, complex oxide pigments, inorganic pigments such as transparent iron oxide, cyclic higher pigments, soluble azo pigments, and insoluble azo pigments. pigment, copper phthalocyanine pigment,
Examples include organic pigments such as dyeing pigments and pigment intermediates.

Further, colorants, thixotropic agents, fillers, thickeners, leveling agents, antifoaming agents, stabilizers, and other additives may be added.

The coating composition of the present invention can be produced by mixing the above components by a conventional method.

The coating composition of the present invention can be used for spray coating,
It is applied onto a substrate by a known and commonly used method such as brush coating or roll coater, and left to harden at room temperature for about 1 to 10 days, or at 60 to 250 °C for 1 minute to 250 °C.
Bake for 30 minutes to harden.

[0035]

Effects of the Invention The coating composition of the present invention has superior weather resistance and improved surface hardness compared to conventional polyester and acrylic resin coatings that have good processability. It also has excellent scratch resistance and stain resistance, and is suitable for pre-coated metal used in architectural exterior panels and home appliances, construction and civil engineering of plants, marine structures, etc.
It can be used in the field of home appliances and transportation vehicles such as automobiles and train cars.

[0036]

Examples Examples 1 to 9 and Comparative Examples 1 to 2 Coating compositions were prepared by mixing the following formulations in the compositions shown in Table 1. The blending amount is shown in weight (g). The material is 0.3mm
The above coating composition was applied to a thick stainless steel plate (SUS 304) to a thickness of about 20μ after baking, and the baking temperature was 1.
It was cured by treating at 60° C. for 20 minutes. The physical properties of the resulting coating film were measured and the results are shown in Table 1.

(1) Polyol resin ○ Acrylic polyol resin Alotane UW2818 (non-volatile content 60 wt%) ○ Polyester resin Desmophen 850 (non-volatile content 100 wt%)
(2) Functional fluororesin ○Cefralcoat A-101B (non-volatile content 55 wt
%)○ Lumiflon LF 200 (non-volatile content 60 wt
%) (3) Isocyanate Coronate 2515 (non-volatile content 80 wt%) (4)
Organosol ○Organotitani sol (C-1) (Non-volatile content 3
0 wt%) ○Organosilica sol (C-2) (non-volatile content
(30 wt%) (5) Solvent Cyclohexanone solvent (6) Curing catalyst Butyltin dilaurate Coating film physical property test method ■ Gloss: 60° reflectance specified by JIS K 5400 ■ Hardness: JIS
Pencil hardness according to K 5400 ■ Bending:
Bending tester φ2mm.

[0038] "○" indicates passing.

■ Xylene: Xylene wiping test.

■ Weather resistance: Sunshine Weather-Ometer accelerated weather resistance test 3000 hours ◎ Initial gloss retention rate 90% or more ○ Initial gloss retention rate 85% or more

[0041]

[Table 1]

Claims (6)

[Claims] Claim 1: One or more polyol resins (A) selected from polyester resins and acrylic polyol resins, a functional fluororesin (B), an isocyanate compound having two or more functional groups, a blocked isocyanate compound, and a melamine compound. one or more selected binders (C);
Group II metals (Mg,
Group III metals (B, Al, Ga)
, In, Tl, Sc, Y, La, Ac), group IV metals (
Si, Ge, Sn, Pb, Ti, Zr, Hf), Group V metals (As, Sb, Bi, V, Nb, Ta), Group VI metals (Te, Po, Cr, Mo, W), Group VII metals (A
t, Mn, Tc, Re) and group VIII metals (Fe, C
one or more metal oxide sols selected from metal oxide sol and salts of metal oxide sol, siloxane, metallosiloxane, silazane, metallosilazane, and mixtures thereof; A coating composition comprising an inorganic organosol (D) and a solvent (E). 2. The composition according to claim 1, further comprising a reaction promoting catalyst (F). Claim 3: The inorganic organosol (D) contains metals belonging to group III of the periodic table of long-period elements (B, Al,
Ga, In, Tl, Sc, Y, La, Ac), group IV (
The composition according to claim 1 or 2, wherein a metal oxide sol selected from group V (As, Sb, Bi, V, Nb, Ta) metals is used. thing. 4. The composition according to claim 1, wherein the inorganic organosol (D) is a metal oxide sol in which the metal is selected from Si, Al, Sn, Ti, and Zr. Claim 5: Polyol resin (A), functional fluororesin (B), binder (C), and inorganic organosol (D)
The blending ratio is (A) 10 to 80% by weight,
(B) 2-80%, (C) 2-50% and (D)
5. A composition according to any one of claims 1 to 4, which has a content of 5 to 60%. Claim 6: Claim 1 wherein the composition further comprises a pigment (G).
6. The composition according to any one of .