JPS6054913B2 - Surface coating agent for ceramics - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a surface coating agent for ceramics, and more specifically, it is used for overcoating, painting, marking, printing marks, etc. on the surface of ceramics such as glass products, ceramics, and enamel products. The present invention relates to a suitable surface coating agent for ceramics.

Conventionally, surface coating agents for ceramics used for such purposes include metals, metal salts, organic compounds of metals, or various metal resin salts, organic solvents, Rosmarin oil,
Paints containing lavender oil and the like are commonly used.

This paint is generally heated at 500°C after being applied or painted on the ceramic surface. While heating to a higher temperature, sufficient air is supplied to completely burn in an oxidizing atmosphere, and the desired topcoat is applied.
This includes painting, markings, markings, etc. However, if the air supply is insufficient, it will greatly affect the color tone and adhesion after firing. It is not possible to obtain the desired color tone or adhesion. On the other hand, the adhesion will be stronger if the baking temperature is as close as possible to the softening point of ceramics such as glass products and chinaware, but rapid heating will cause distortions, cracks, and damage to the container, so It is necessary to raise the temperature to the desired maximum temperature range while heating it. Therefore, the firing time is long and a large-scale firing furnace is required. This also applies to the cooling operation after firing. For this reason, until now, many troubles have been observed that occur with the control of firing temperature and firing time, and at the same time, there has been a strong demand for labor-saving heat sources.

Therefore, the purpose of the present invention is to eliminate the above-mentioned problems of the conventional surface coating agents for ceramics, save labor on heat sources, improve workability, increase productivity, shorten baking time, and improve product quality. An object of the present invention is to provide a surface coating agent for ceramics that eliminates the troubles described above.

The surface coating agent for ceramics according to the present invention has the formula (1) (
acrylic acid or methacrylic acid or an ester thereof of the formula (wherein R1 is H and CH3 and R2 is H and an alkyl group) and an ester thereof of the formula (wherein R1 is as defined above and R3 is an alkylene group); containing at least 8% by weight of acrylic acid or methacrylic acid hydroxyalkyl ester of
00 to 5,000 and a hydroxyl value of 80 to 400 (hereinafter sometimes simply referred to as copolymer (1)), and (Ii) at least one selected from the group of amino resins and polyfunctional isocyanates. .

The surface coating agent for ceramics of the present invention can significantly lower the baking temperature compared to conventional ones, so it can save labor on heat sources, shorten baking time (and cooling time), and prevent troubles on ceramic products. This makes it possible to improve productivity and improve operability. Furthermore, topcoating, painting, graduation, mark printing, etc. obtained by baking the surface coating agent of the present invention have adhesive strength equivalent to conventional ones, and have excellent gloss and high hardness. The above (1) to be blended into the surface coating agent for ceramics of the present invention
The copolymer is a copolymer of acrylic acid or methacrylic acid or its ester of formula [1] and a hydroxyalkyl ester of acrylic acid or methacrylic acid of formula [■], or 8% by weight of these as monomer units. Vinyl monomers including the above and copolymerizable with these monomers, such as vinyl acetate, vinyl propionate, vinyl versatility, vinyl chloride, vinylidene chloride, styrene, α-methylstyrene, acrylonitrile, ethylene, propylene, methacrylamide , N-methylolmethacrylamide, acrylamide, itaconic acid, butadiene, methyl vinyl ether, diallyl phthalate, and mixtures thereof as monomer units in an amount of 2% or less.

The compound of formula [1] is preferably one in which R2 is H or a linear or branched alkyl group having 1 to 8 carbon atoms, such as acrylic acid, methyl acrylate, etc. , ethyl acrylate, propyl acrylate, butyl acrylate, pentyl acrylate, hexyl acrylate, heptyl acrylate, octyl acrylate, methacrylic acid, methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, methacrylic acid Examples include pentyl, hexyl methacrylate, heptyl methacrylate, octyl methacrylate, and arbitrary mixtures thereof.

As a compound of the above formula [■], R3 in the formula has 1 to 6 carbon atoms.
A linear or branched alkylene group is preferred, and examples of such compounds include hydroxymethyl ester, hydroxyethyl ester, hydroxypropyl ester, hydroxybutyl ester, hydroxypentyl ester and hydroxyhexyl ester of acrylic acid, and hydroxyhexyl ester of methacrylic acid. Hydroxymethyl ester, hydroxyethyl ester, hydroxypropyl ester, hydroxypentyl ester and hydroxyhexyl ester, and any mixtures thereof.

These monomers can be copolymerized using any conventionally known polymerization method, such as bulk polymerization, suspension polymerization, solution polymerization, etc., under normal pressure or increased pressure.

Number average molecular weight of copolymer (1) (vapor pressure osmosis method VapO
rPressureOsmOmetryMethOd)
is preferably about 500 to 5000, and preferably about 700 to 5
More preferably, it is within the range of 000.

This is because when the number average molecular weight is 500 or more, the stickiness becomes even smaller, and the hardness and chemical resistance are also significantly superior.
00 or less, the composition becomes even harder and less brittle than the film, and the dispersibility of the pigment becomes even greater. Furthermore, within the above molecular weight range, the adhesion to ceramic substrates is extremely excellent. The composition ratio of the monomers [1] and [■] is such that the hydroxyl value of the resulting copolymer is preferably 80 to 400.
1, more preferably within the range of 100 to 300.

This is because when the number of hydroxyl groups is 80 or more, more sufficient hardness can be obtained, and various physical properties such as chemical resistance are also better. The amount of amino resin and/or polyfunctional isocyanate added can be reduced within
This is because it becomes easier to control the hardness, and at the same time, it also becomes more excellent in flexibility. In addition, the hydroxyl value is JIS・33
42 (1961) (acetic anhydride-pyridine method). The surface coating agent for ceramics of the present invention contains an amino resin and/or a polyfunctional isocyanate as a crosslinking agent in addition to the copolymer (1).

The amino resins used in the present invention include etherified methylol melamine resins, such as methylated methylol melamine, ethylated methylol melamine, butylated methylol melamine, isopropylated methylol melamine, etc.; etherified methylol urea resins, such as methylated methylol melamine; Urea, ethylated methylol urea, butylated methylol urea, etc.; etherified methylol urea melamine cocondensates, such as methylated methylol urea melamine, ethylated methylol urea melamine, butylated methylol urea melamine, etc., and any mixtures thereof, etc. can be given.

These amino resins are preferably blended in a proportion of 0.2 to 1.0 reaction equivalent per equivalent of hydroxyl group in the copolymer. This is because when the amount of amino resin blended is 0.2 reaction equivalent or more, sticking (tank) is eliminated and physical properties such as hardness and chemical resistance are excellent, whereas when the blended amount is 1.0 When it is less than the reaction equivalent, the film becomes hard, has excellent flexibility, and has good adhesion to the substrate, which is preferable. After coating, the ceramic surface coating agent of the present invention containing an amino resin is baked at a temperature of 80 to 250°C, preferably 100 to 220°C, for 2 to 120 minutes, preferably for 5 to 6 minutes. Examples of polyfunctional isocyanates include tolylene diisocyanate and its hydrogenated products and adducts, triphenylmethane triisocyanate, methylene bis-diphenyl isocyanate and its hydrogenated products, hexamethylene diisocyanate,
Xylene diisocyanate and its hydrogenated product, 4,4″
-dicyclohexylmethane diisocyanate, isophorone diisocyanate, dianisidine diisocyanate,
Examples include tridene diisocyanate, metaxylylene diisocyanate triallyl isocyanate, blocked polyisocyanate in which a functional group is blocked, and any mixture thereof.

These polyfunctional isocyanates are preferably blended in a proportion of 0.7 to 1.5 reaction equivalents per equivalent of hydroxyl group in the copolymer. This is because when the amount of polyfunctional isocyanate blended is 0.7 reaction equivalent or more, sticking (tank) is eliminated and physical properties such as hardness and chemical resistance are excellent. When the reaction equivalent is 1.5 or less, the film becomes hard, has excellent flexibility, and has good wettability and adhesion to the substrate, which is preferable. The ceramic surface coating agent of the present invention containing a polyfunctional isocyanate has a zero
Curing is carried out at a temperature of ~150°C1, preferably 10-100°C.

The curing time depends on the curing temperature, catalyst, etc., but is usually 5 hours or less, preferably about 3 seconds to 8 hours. The copolymer (1) and the amino resin and/or polyfunctional isocyanate can be mixed by any conventionally known method.
The surface coating agent for ceramics of the present invention includes the above-mentioned copolymer and an amino resin and/or a polyfunctional isocarbon. In addition to the cyanate, a curing catalyst is generally included.

As curing catalysts to be added to the surface coating agent for ceramics of the present invention, conventionally, amino resins, blends of amino resins and thermoplastic resins having functional groups (for example, coating resins such as melamine-alkyd, melamine-acrylic, etc.) have been used. ) or the like, or catalysts commonly used for accelerating the reaction of isocyanates, etc. can be used. Typical curing catalysts used in the present invention include organic acids and their salts,
For example, valatoluenesulfonic acid, phthalic anhydride, benzoic acid, benzenesulfonic acid, formic acid, acetic acid, itaconic acid,
Oxalic acid, maleic acid and their ammonium salts, lower amine salts: Inorganic acids and their salts, such as hydrochloric acid, nitric acid,
Sulfuric acid, phosphoric acid and their ammonium salts, lower amine salts, polyvalent metal salts, etc. For polyfunctional isocyanates, amines such as trimethylamine, triethylamine, tripropylamine, tributylamine, phenylamine, triethylenediamine ; Metal compounds, such as stannath octoate, dibutyltin di-2-ethyhexoate, dibutyltin dilaurate, red-2-ethylenehexo'ate, sodium O-phenyl phenate, potassium oleate, bismuth nitrate, tetra(2-ethylhexyl) titanate; , stannic chloride, ferric chloride, iron 2-ethylhexoate, cobalt 2
- ethylhexoate, zinc naphthenate, antimony trichloride, etc. The amount of these catalysts used is 2% by weight or less based on the total resin components, preferably 0.01 to 1% by weight in the case of amino resins, and 10 ppm to 1% by weight in the case of polyfunctional isocyanates. be. The surface coating agent for ceramics of the present invention may further contain a solvent such as xylene, butanol, ethyl acetate, methyl ethyl ketone, methyl isobutyl ketone, paint thinner, titanium white,
White lead, zinc white, aluminum powder, red iron, ocher, pallas,
Pigments such as risol and bolt; phthalate esters, phosphate esters, epoxidized vegetable oils, polyesters,
Plasticizers such as epoxy; stabilizers such as lead salts, metal soaps, organic tins, and epoxy compounds; antioxidants such as amines, phenols, phosphorous acid derivatives, and sulfur compounds;
Ultraviolet absorbers such as phenyl salicylate type, benzophenone type, benzotriazole type, etc. can be blended.

The amounts of these additives are the same as those commonly used in the past. The surface coating agent for ceramics of the present invention can be applied to the surface of ceramics by brush painting, brush painting, spray painting, etc., or by painting, marking, mark printing, etc. in the same manner as conventional ones. I can do it.

According to the present invention, since any pigment can be blended, the color tone of overcoating, painting, graduation, mark printing, etc. can be freely controlled, and there is no need to use toxic heavy metal compounds as in conventional methods. , a finish with high gloss, high hardness and strong adhesion can be obtained.

Hereinafter, the present invention will be explained in more detail with reference to Examples.

Example 1 Synthesis of oligomer The radical generator, solvent, and polymerization degree regulator shown in Table 1 were charged into a reaction apparatus equipped with a dropping device, a stirrer, a thermometer, and a reflux condenser, and while stirring, the radical generator, solvent, and polymerization degree regulator shown in Table 1 were charged. The temperature was raised to the indicated reaction temperature.

After raising the temperature, add about 40% of the monomer mixture shown in Table 1 from the dropping device.
The reaction was continued at the reaction temperature shown in Table 1 for an additional 2 hours. The resulting oligomer solution was concentrated in vacuo to obtain a % solids oligomer. In this way, 1 to 9 types of oligomers shown in Table 1 were produced. The abbreviations in the monomer compositions in Table 1 are as follows. AA...acrylic acid, MA...methyl acrylate, EA...ethyl acrylate, BA...butyl acrylate, 2EHA...2ethylhexyl acrylate, MA...methacrylic acid, MMA...・Methyl methacrylate, BMA...butyl methacrylate, 2HEA
...2-hydroxyethyl acrylate, 211EMA
...2-hydroxyethyl methacrylate, HPMA・
...Hydroxypropyl methacrylate, ■Ac...Vinyl acetate.

A surface coating agent was prepared by blending each component. That is, first, oligomer, amino resin, pigment (Tybake R-93
0, Shiraishi Sangyo TiO2) and xylene were placed in a plastic container together with glass beads, and then vibrated for 2 hours using a multipurpose shaker (manufactured by Iwaki Co., Ltd.). A surface coating agent A-N*1 (J-N is a comparative example) was prepared by adding 0.5 parts of toluenesulfonic acid.

In Table 2, Nikaratsuk MW-30 is methylated methylolmelamine manufactured by Sanwa Chemical Co., Ltd., Nikaratsuk MS1001 is butylated methylolmelamine manufactured by Sanwa Chemical Co., Ltd., and Nikaratsuk MX-201 is Sanwa Chemical Co., Ltd. (butylated methylolmelamine). Co., Ltd. methylated methylol urea and Cymel 30
3 is methylated methylolmelamine manufactured by ACC. It was mixed with a polyfunctional isocyanate so that 0H/NCO=1/1, diluted with ethyl acetate so that the blended resin concentration was 75% by weight, and further mixed with 0H/NCO based on the resin content. A surface coating agent 0-W (U-W is a comparative example) was obtained by adding an organic tin catalyst (dibutyltin dilaurate) in an amount of %. Coronate L is Trirundiisocyanate manufactured by Nippon Polyurethane Co., Ltd.
Takenate D-110N is a xylylene diisocyanate made by Takeda Pharmaceutical Co., Ltd., and Takenate D-120N is a hydrogenated xylylene diisocyanate made by Takeda Pharmaceutical Co., Ltd. Example 4 Scratch Resistance Test A commercially available 200cc glass reagent bottle was thoroughly washed and dried, and a 3cm
The surface coating agent A-N prepared in Example 2 was applied with a brush to an area of 7 cm x 7 cm, and two powders were baked in a hot air dryer at 180°C.

Fill a wooden box with two bottles of each surface coating agent.
These were vibrated with a vibrator under the following condition-1, and the extent of scratches generated during the vibration was examined. Similarly, the following condition-2
and tested under condition-3. The results are shown in Table 4. ■
↓Explanation; yA'n) Example 5 Alkali resistance test Glass bottles are usually washed using a 3-4% caustic soda solution at 50-60°C for 5-1 days, so the alkali resistance test of the surface coating agent was carried out under such conditions.

That is, samples obtained by coating and baking the surface coating agent A-N on the surface of a commercially available glass bottle in the same manner as in Example 4 were tested for peelability and gloss after being immersed in 6 powders, 12 powders, and 24 powders under the above conditions. For peelability, those with no peeling were judged to be good with the naked eye, and those with peeling were judged as poor, and the gloss was measured by 60 degree specular gloss according to JIS-K-5400. The results are shown in Table 5. Example 6 Adhesion to glass and various physical properties test 10cm×
The surface coating agent prepared in Examples 2 and 3 was applied to a 10CTn glass plate to a film thickness of 25 to 30μ, and the surface coating agent A-N was heated at 180°C for 20 minutes, and the surface coating agent 0-W5O°C.
6 powders were baked and tested for hardness, adhesion, staining resistance, and chemical resistance.

However, the surface coating agent 0-W was measured after being left for 2 days. The results are shown in Table 6. The measurement method is as follows. (1) Hardness: Pencil scratch test (JIS-K-54
(2) Adhesion: Use a razor to make 100 goblets of 1Tfn x 1Tn on the coating surface to reach the substrate.
After making a cellophane, cellophane tape was pressed onto it, the tape was immediately removed, and the number of remaining gobans was examined.

Judgment: The higher the number remaining, the better the adhesion. (3) Stain resistance: After staining the surface with an oil-based black marker, wipe it off with alcohol.

OK, Δ acceptable, × unacceptable. (4) Chemical resistance: 5%HC
1 each in 1, 10% NaCl and toluene.
＠Soak for a while, then check the swelling and peeling state.
Judgment was made in accordance with TM standard D714-56.

No. 2=5Tn! N. ．． No. 4=2wt1N0
．． 6=1 number, NO. 8=0.5w! TOD: Dark, MD: Medium dark, M: Medium,
F: Few things.

Example 7 Adhesion test on unglazed tiles An unglazed tile was cut to a size of 10c1n x 10cm, and the surface coating agent prepared in Examples 2 and 3 was applied to it to a film thickness of 30cm to 30cm.
The coating was applied to a thickness of 35μ, and the one prepared in Example 2 was 18μ.
0 × 20 minutes, the one prepared in Example 3 was 50 °C × 60 minutes,
Each was baked and 100 pieces of 2Tn x 2L were prepared in the same manner as in Example 6, and a tape peeling test was conducted after boiling them in boiling water for 8 hours and after exposing them outdoors for 6 months.

Claims (1)

[Claims] 1 (i) Formula▲There are mathematical formulas, chemical formulas, tables, etc.▼...[
I] (In the formula, R^1 is H and CH_3, R^2 is H and an alkyl group) Acrylic acid or methacrylic acid or its ester and the formula ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼... [II] (wherein R^1 is as defined above and R^3 is an alkylene group) A number average containing at least 80% by weight of a hydroxyalkyl ester of acrylic acid or methacrylic acid as a monomer unit A surface coating agent for ceramics comprising an oligomer having a molecular weight of 500 to 5000 and a hydroxyl value of 80 to 400, and (ii) at least one member selected from the group of amino resins and polyfunctional isocyanates. 2. The surface coating agent according to claim 1, wherein R^2 in the compound of formula [I] is H or an alkyl group having 1 to 8 carbon atoms. 3 In the compound of the above formula [II], R^3 has 1 to 1 carbon atoms
Claim 1 or 2 which is an alkylene group of 6
Surface coating agent described in section. 4 The oligomer (i) is vinyl acetate, vinyl propionate, vinyl versatate, vinyl chloride, vinylidene chloride, styrene, α-methylstyrene, acrylonitrile, ethylene, propylene, methacrylamide, N-
Claims 1 to 3 contain, as a monomer unit, 20% by weight or less of at least one copolymerizable monomer selected from the group of methylolmethacrylamide, acrylamide, itaconic acid, butadiene, methyl vinyl ether, and diallyl phthalate. The surface coating agent according to any one of items 1 to 1. 5. Any one of claims 1 to 4, wherein the amino resin is at least one selected from the group of etherified methylol melamine resins, etherified methylol urea resins, and etherified methylol urea melamine cocondensates.
The surface coating agent described in section. 6 The polyfunctional isocyanate is tolylene diisocyanate and its hydrogenated products and adducts, triphenylmethane triisocyanate, methylene bis-di-phenyl isocyanate and its hydrogenated products, hexamethylene diisocyanate, xylene diisocyanate and its hydrogenated products, 4 , 4'-dicyclohexylmethane diisocyanate, isophorone diisocyanate, dianisidine diisocyanate, tridecine diisocyanate, metaxylylene diisocyanate, triallylisocyanurate, blocked polyisocyanate, and a polymer thereof. The surface coating agent according to any one of the ranges 1 to 5. 7 The composition ratio of the oligomer (i) and the amino resin is 0.2 to 1 amino resin per equivalent of hydroxyl group of the copolymer.
．． The surface coating agent according to claim 1, which has a reaction equivalent of 0. 8. The composition according to claim 1, wherein the composition ratio of the oligomer (i) and the polyfunctional isocyanate is 0.7 to 1.5 reaction equivalents of the polyfunctional isocyanate per equivalent of hydroxyl group of the copolymer. Surface coating agent. 9. The surface coating agent according to any one of claims 1 to 8, wherein the ceramic is a glass product, ceramic, or enamel product.