JPH059432A - Resin composition for water-based coating material - Google Patents

Abstract

PURPOSE:To provide the title composition which is excellent in stability and can give a coating film excellent in water resistance, humidity resistance and corrosion resistance. CONSTITUTION:A resin composition for a water-based coating material containing a resin of an acid value of 30 or below, obtained by condensing 0-60 pts.wt. oil or fatty acid (a) with 10-50 pts.wt. polyalcohol (b), 0-25 pts.wt. monobasic acid (c), 10-60 pts.wt. polybasic acid or its anhydride (d), 0-40 pts.wt. phenolic resin (e), 0-40 pts.wt. epoxy compound (f) [the total of components (a) to (f) is 100 pts.wt., the ratio of the number of the hydroxyl groups to that of the carboxyl groups is 1/1-1.6/1], and 1-10 pts.wt., per 100 pts.wt. total of components (a) to (f), polyoxyethylenediglycolic acid (g) of general formula: HOOC-CH2-(OCH2CH2)n-O-CH-COOH [wherein n is an integer of 6 or greater].

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a resin composition for water-based paint.

[0002]

2. Description of the Related Art Since a large amount of organic solvent is usually used for paint, the organic solvent is discharged into the atmosphere during painting, which causes air pollution, and there is a high risk of fire. In recent years, various efforts have been made to reduce the amount of organic solvent, and high solid paints, powder paints, electron beam / ultraviolet curable paints, water-based paints, etc. have been developed for that purpose. In particular, water-based paints have attracted attention because they use water that is non-hazardous and highly economical, and can be easily converted from conventional coating equipment. However, in conventional water-based paint,
It has drawbacks such as slow drying of paint and poor water resistance and corrosion resistance.

In order to improve such a defect, various methods have been considered so far, for example, a method of incorporating a phenol resin, a petroleum resin, an epoxy resin, etc. in a resin component in an aqueous alkyd resin coating, a polymerizable monomer. Examples thereof include a method of polymerizing the monomer.

As one of these, a resin synthesized by using polyoxyethylene glycol as one component of an alkyd resin is known. This is because by introducing polyoxyethylene glycol into the resin, it is possible to impart self-emulsifying properties, so compared to conventional water-soluble alkyds or water-dispersed alkyds using a dispersant, organic solvents and amines. There is an advantage that the usage amount of can be suppressed.

Since this polyoxyethylene glycol-modified alkyd resin can reduce the acid value as an aqueous resin,
It is possible to provide a coating film having a high heating residue and excellent corrosion resistance and water resistance. However, polyoxyethylene glycol, which is a dihydric alcohol, undergoes a condensation reaction with an acid. However, in the usual alkyd resin formulation, the number of hydroxyl groups / the number of carboxyl groups is 1.1 to 1.6, which is an excessive number of hydroxyl groups. In order to react, most of the alkyd resin is in an oligomer state in a relatively low molecular weight portion,
Alternatively, some remain unreacted. Therefore, for example, in water resistance and moisture resistance, sufficient performance is not obtained as compared with the solvent type.

[0006]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a resin composition for water-based coatings, which is capable of forming a coating film having excellent coating stability, water resistance, moisture resistance and corrosion resistance.

[0007]

According to the present invention, a polyoxyethylene group can be easily introduced into an alkyd resin by using polyoxyethylene diglycolic acid instead of polyoxyethylene glycol, and it remains unreacted. The above objectives have been achieved based on the finding that there is no such thing.

The present invention comprises (a) oil or fatty acid 0 to 60 parts by weight, (b) polyhydric alcohol 10 to 50 parts by weight, (c) monobasic acid 0 to 25 parts by weight, (d) polybasic acid or Anhydrous 10 to 60 parts by weight, (e) Phenolic resin 0 to 40 parts by weight, (f) Epoxy compound 0 to 40 parts by weight and (however, (a) to (f) are 100 parts by weight in total, and hydroxyl group number / carboxyl groups is 1/1 to 1.6 / 1] (g) the general formula _{(I) HOOC-CH 2 -} (OCH 2 CH 2) n -O-CH 2 -COOH (I) wherein , N is an integer of 6 or more] an acid obtained by condensation reaction of 1 to 10 parts by weight of polyoxyethylene diglycolic acid [based on 100 parts by weight of the total of (a) to (f)] The present invention relates to a resin composition for water-based coating material containing a resin having a value of 30 or less.

The present invention also includes (a) oil or fatty acid 0 to 60 parts by weight, (b) polyhydric alcohol 10 to 50 parts by weight, (c) monobasic acid 0 to 25 parts by weight, and (d) polybasic. Acid or its anhydride 10-60 weight part, (e) Phenolic resin 0-40 weight part and (f) Epoxy compound 0-40 weight part are 100 weight parts in total, and hydroxyl group number / carboxyl group number is 1 / 1-. 1.6 / 1 to become so by blending against alkyd resin 100 parts by weight obtained by condensation reaction, (g) the general formula _{(I) HOOC-CH 2 -} (OCH 2 CH 2) n -O- CH ₂ —COOH (I) [wherein, n is an integer of 6 or more] 1 to 10 parts by weight of a polyoxyethylene diglycolic acid represented by the formula is blended,
Further, the present invention relates to a resin composition for water-based coatings, which contains a resin having an acid value of 30 or less obtained by a condensation reaction.

The component (a) used in the present invention includes drying oil, semi-drying oil, non-drying oil, and fatty acids derived from these and synthetic fatty acids. For example, tung oil, soybean oil, linseed oil, castor oil. , Dehydrated castor oil, safflower oil, cottonseed oil, coconut oil, palm oil and fatty acids obtained from them,
For example, versatic acid obtained by synthesis.

These components (a) may be optionally used alone or in combination of two or more depending on the desired coating performance. The amount used is 0 to 60 parts by weight, preferably 25 to 55 parts by weight, based on 100 parts by weight of the total amount of the components (a) to (f). If the amount of component (a) used exceeds 60 parts by weight, the hardness and corrosion resistance of the coating film will decrease.

As the component (b), ethylene glycol, propylene glycol, diethylene glycol, neopentyl glycol, 1,4-butanediol, 1,
6-hexanediol, glycerin, dipropylene glycol, trimethylolpropane, trimethylolethane, tris (2-hydroxyethyl) isocyanurate, tris (hydroxymethyl) isocyanurate, pentaerythritol, 1,4-methylpentanediol, butylethyl Glycol and the like can be used.

These components (b) can be optionally used alone or in combination of two or more depending on the desired coating performance. The amount used is 10 to 50 parts by weight, preferably 15 to 40 parts by weight, based on 100 parts by weight of the total amount of the components (a) to (f). When the amount of the component (b) used is less than 10 parts by weight, the acid value of the resin is too high and the water resistance and the like decrease.
On the other hand, if it exceeds 50 parts by weight, the molecular weight of the resin is too small, and the drying property, water resistance and the like are deteriorated.

The monobasic acid which is the component (c) used in the present invention is aromatic or fatty acid such as benzoic acid, methylbenzoic acid, p-tert-butyl-benzoic acid, isodecanoic acid, cyclohexanoic acid, isooctanoic acid. Group carboxylic acids can be used.

These components (c) may be optionally used alone or in combination of two or more depending on the desired coating performance. The amount used is 0 to 25 parts by weight, preferably 0 to 10 parts by weight, based on 100 parts by weight of the total amount of the components (a) to (f). When the amount of the component (c) used exceeds 25 parts by weight, the molecular weight of the resin is too small, and the drying property, water resistance and the like are deteriorated.

Examples of the polybasic acid or its anhydride which is the component (d) used in the present invention include phthalic acid, isophthalic acid,
Terephthalic acid, tetrahydrophthalic acid, hymic acid,
Examples thereof include maleic acid, fumaric acid, adipic acid, sebacic acid, dimer acid, trimellitic acid, het acid, dodecanedioic acid, and acid anhydrides thereof.

These components (d) can be optionally used alone or in combination of two or more depending on the desired coating performance. The amount used is 10 to 60 parts by weight, and preferably 15 to 50 parts by weight, based on 100 parts by weight of the total amount of the components (a) to (f). When the amount of the component (d) used is less than 10 parts by weight, the molecular weight of the resin is too small, and the drying property and water resistance are deteriorated. On the other hand, when it exceeds 60 parts by weight, the acid value of the resin is too high and the water resistance and the like decrease.

The phenol resin used as the component (e) is a resin obtained by reacting phenols with formaldehyde in an acidic or alkaline manner, for example, Hitanol 2300, 1501, 1133, 1140 (all are products of Hitachi Chemical Co., Ltd. And the like, and further include rosin-modified phenol resin, terpene-modified phenol resin, xylene-modified phenol resin, and the like. The above-mentioned phenols refer to o-, m- and p-substituted compounds such as carboxylic acid, cresol, xylenol, propylphenol, butylphenol, amylphenol, octylphenol, nonylphenol and dodecylphenol, and their isomers. Further, phenylphenol, cumylphenol, bisphenol A, etc. are also included in the phenols.

These components (e) can be optionally used alone or in combination of two or more depending on the desired coating performance. The amount used is 0 to 40 parts by weight, preferably 0 to 20 parts by weight, based on 100 parts by weight of the total amount of the components (a) to (f). If the amount of component (e) used exceeds 40 parts by weight, the stability of the water-based paint over time will be poor and water will be easily separated.

As the epoxy compound as the component (f), a bisphenol type epoxy resin obtained by reaction of bisphenols such as bisphenol A and F with epichlorohydrin, for example, Epicoat 828, 1001,
Commercially available products such as 1004, 1007 and 1009 (all are trade names of Shell Chemical Co.) can be used. Furthermore, an aliphatic epoxy compound having one or more glycidyl groups in the molecule can also be used. Examples of the compound include lauryl alcohol, glycidyl ether of monohydric aliphatic alcohol such as allyl alcohol, alkylene glycol such as ethylene glycol, propylene glycol and butylene glycol, diethylene glycol, polyethylene glycol, dipropylene glycol, poly (tetramethylene glycol), 1,6
-Glycidyl ethers of dihydric aliphatic alcohols such as hexanediol and neopentyl glycol, di- or tri-glycidyl ethers of trihydric aliphatic alcohols such as trimethylolpropane and glycerin, pentaerythritol, sorbitol, glycerin dimer, glycerin There are di-, tri- or tetra-glycidyl ethers of tetrahydric or higher aliphatic alcohols such as multimers, glycidyl esters of versatic acid, diglycidyl esters of aliphatic dicarboxylic acids such as adipic acid and tetramethylene dicarboxylic acid.

These components (f) may be optionally used alone or in combination of two or more depending on the desired coating performance. The amount used is 0 to 40 parts by weight, preferably 0 to 30 parts by weight, based on 100 parts by weight of the total amount of the components (a) to (f). When the amount of the component (f) used exceeds 40 parts by weight, weather resistance and the like deteriorate.

In the present invention, the components (a) to (f) are blended so that the total amount is 100 parts by weight and the number of hydroxyl groups / the number of carboxyl groups is 1/1 to 1.6 / 1,
React to give an alkyd resin. If the number of hydroxyl groups / the number of carboxyl groups is less than 1/1, the acid value of the resin will be too high, and the water resistance will decrease. On the other hand, when it exceeds 1.6 / 1, the molecular weight of the resin is too small, and the drying property, water resistance and the like decrease.

The alkyd resin is obtained by subjecting the components (a) to (f) to an addition / condensation reaction by a known method. For example, components (a) to (f) are blended at the same time,
It may be heated to 210 to 230 ° C. This reaction may be carried out in an organic solvent which does not react with the components (a) to (f) such as xylene and toluene. Further, the component (g) described below may be blended at the same time as the components (a) to (f) and reacted together, and further after reacting the components (a) to (d),
You may add and react components (e), (f), and (g). However, during the reaction of (g) component (particularly (a)-
From the viewpoint of characteristics, it is preferable to add and react the component (f) after first condensing it.

The component (g) used in the present invention is represented by the above general formula (I), in which n is an integer of 6 or more.
If it is less than 6, the miscibility with the pigment or the like is lowered, the pigment or the like is apt to aggregate, and the storage stability is deteriorated.

The component (g) has a molecular weight of 400 to 20.
000 polyoxyethylene diglycolic acid can be used. If this molecular weight is too small or too large, storage stability tends to decrease. The amount of the component (g) used is 1 to 10 parts by weight based on 100 parts by weight of the components (a) to (f). If the amount used is less than 1 part by weight, a stable aqueous resin cannot be obtained, and if it exceeds 10 parts by weight, the water resistance, moisture resistance, corrosion resistance, and further drying property of the coating film,
Inferior hardness.

In the present invention, the resin obtained by reacting the components (a) to (g) in the above-mentioned blending ratio needs to have an acid value of 30 or less. When the acid value exceeds 30, the water resistance, moisture resistance, corrosion resistance and alkali resistance of the coating film deteriorate.

It is preferable to neutralize the above alkyd resin and add a water-soluble solvent before dispersing it in the emulsified water in order to improve the water dispersibility of the resin. Examples of such a water-soluble solvent include 3-methyl-3-methoxybutanol, methyl cellosolve, ethyl cellosolve,
Butyl cellosolve, tert-butyl cellosolve, isopropyl cellosolve, isopropyl alcohol, n-butyl alcohol, tert-butyl alcohol, isobutyl alcohol and other alcohols, tetrahydrofuran and other ethers, acetone and other ketones, and methyl acetate and other ester solvents. Can be used.

The neutralization is carried out by neutralizing a part or all of the carboxyl groups in the resin with a neutralizing agent so that the pH is preferably 6-9. Examples of the neutralizing agent include amines such as ammonia, triethylamine and dimethylethanolamine, alkali metal hydroxides such as sodium hydroxide and potassium hydroxide, alkali metal carbonates such as sodium carbonate, and bicarbonates such as sodium bicarbonate. Can be used.

The resin composition for water-based coating thus obtained can be used as it is as a water-based coating after dilution, but as other components, pigment, plasticizer, solvent,
A colorant or the like may be added, or a wide range of water-soluble or water-dispersible resins such as modified amino resin, epoxy resin, polyester resin and acrylic resin may be blended. For example, by combining with a modified amino resin, an epoxy resin or the like, it can be used as a paint for baking. In particular, among the aqueous resins obtained by the present invention, a drying oil or a semi-drying oil, or a fatty acid derived therefrom can be used. When used, the one to which a metal desiccant is added is useful as a room temperature curable paint. These can be made into a coating material by adding a pigment, a surface treatment agent, an organic solvent and the like which are usually used.

The coating composition can be applied by a method such as a dipping method, brush coating, spray coating or roll coating, and can be applied to wood, paper, fibers, plastics, ceramics, iron,
It can be painted on the surface of non-ferrous metals.

[0031]

EXAMPLES Next, the present invention will be described in detail with reference to examples, but the present invention is not limited to these.

Example 1 Soybean oil fatty acid 12 in a 1 liter flask equipped with a stirrer, thermometer, reflux dehydrator and inert gas inlet tube.
0 g, dehydrated castor oil fatty acid 115 g, tris (2-hydroxyethyl) isocyanurate 164 g, glycerin
7.8 g, pentaerythritol 24.3 g, isophthalic acid 140 g, Epicoat 1007 (trade name of epoxy resin manufactured by Shell Chemical Co.) 60 g, and Hitanol 1140
(Hitachi Chemical Co., Ltd. phenolic resin product name) 60 g was added, the temperature was kept at 230 ° C., the condensation was advanced until the acid value reached 40, and then 25 g of polyoxyethylene diglycolic acid (molecular weight 4000) was added, and 230 The temperature was kept at 0 ° C. and the condensation proceeded until the acid value reached 14. 30 g of 3-methyl-3-methoxybutanol and 1.9 g of triethylamine were added to 100 g of the obtained resin, and water of 118 was added at 50-60 ° C.
g was added to obtain an aqueous dispersion having a heating residue of 40% by weight.

Example 2 Soybean oil fatty acid 12 in a 1 liter flask equipped with a stirrer, a thermometer, a reflux dehydrator and an inert gas inlet tube.
0 g, dehydrated castor oil fatty acid 115 g, tris (2-hydroxyethyl) isocyanurate 164 g, glycerin
After adding 7.8 g, pentaerythritol 24.3 g, isophthalic acid 140 g and hitanol 1140 (trade name of phenol resin manufactured by Hitachi Chemical Co., Ltd.) and keeping the temperature at 230 ° C. and proceeding to condensation until the acid value becomes 30, Polyoxyethylene diglycolic acid (molecular weight 1000) 48g
Was added and the temperature was maintained at 230 ° C., and the condensation was advanced until the acid value became 10. 30 g of 3-methyl-3-methoxybutanol and 100 g of triethylamine were added to 100 g of the obtained resin.
Then, 118.5 g of water was added at 50 to 60 ° C. to obtain an aqueous dispersion having a heating residue of 40% by weight.

Comparative Example 1 Using the same apparatus as in Example 1, the same amount of polyethylene glycol (molecular weight 4000) was used in place of the polyoxyethylene diglycolic acid in Example 1, but otherwise the acid value was 14 Was obtained. When the obtained resin was emulsified, the viscosity became abnormally high during the emulsification process and the resin could not be dispersed. Further, a resin obtained in the same manner by initially charging polyethylene glycol could not be emulsified.

Comparative Example 2 Using the same apparatus as in Example 1, 50 g of polyethylene glycol (molecular weight 4000) was charged from the beginning in place of polyoxyethylene diglycolic acid in Example 1.
Other than that, a resin having an acid value of 14 was obtained by the same composition and process. The obtained resin was emulsified in the same manner as in Example 1 to obtain an aqueous dispersion having a heating residue of 40% by weight.

The resins obtained in the above Examples and Comparative Examples were made into paints as described below and tested. White enamel paint formulation Titanium white (rutile type) 50 g Butyl cellosolve 5 g Water 5 g Water dispersion of resin obtained in Examples or Comparative Examples 125 g Defoamer (BYK022) 0.1 g 6% Cobalt naphthenate 0.5 g 12% Naphthene Zirconate 0.5g

The above composition was dispersed in the presence of glass beads using a sand grinder at 1250 rpm for 60 minutes, and the glass beads were removed to obtain white enamel.

The white enamel thus obtained was diluted with an appropriate amount of water and prepared in a Ford cup # 4 for 30 to 35 seconds. Table 1 shows the test results of the stability of the paint and the characteristics of the coating film.
Shown in.

Test plate preparation conditions Base material: Bonderite # 1077 treated steel plate (Nihon Test Panel Co., thickness 0.8 mm) Painting: Air spray (Iwata Weider 61, caliber 1.5 mm),
Pneumatic 4 kg / cm ² dry; 22 to 24 ° C. for 3 days

Evaluation criteria Curing time: Time (min) at which fingerprint marks are no longer left after pressing the coating film with finger pressure Gloss; 60 degree specular reflectance hardness; Pencil hardness that does not destroy the coating film Paint stability; 7 days at 50 ° C. A paint composition in which the paint components were uniformly dissolved or dispersed even after standing was regarded as good. Corrosion resistance: Performed according to the salt spray test of JIS-K5400. A rust width of 1 mm or less was considered good. Water resistance: After immersing in water at 40 ° C. for 7 days, those without blister generation were evaluated as good.

[0041]

[Table 1]

Example 3 Using the same apparatus as in Example 1, 35 g of Cardular E10 (glycidyl ester of versatic acid, trade name of Shell Chemical Co.), 112 g of trimethylolpropane, 183.6 g of neopentyl glycol, 264.4 g of isophthalic acid.
And 140 g of adipic acid were added and kept at 220 ° C,
After the condensation proceeded until the acid value reached 40, 18 g of polyoxyethylene diglycolic acid (molecular weight 4000) was added, the temperature was kept at 210 ° C., and the condensation proceeded until the acid value reached 20. 3-methyl-3 was added to 100 g of the resin thus obtained.
-Methoxybutanol (30 g) and triethylamine (2.2 g) were added, and water (118 g) was added at 50-60 ° C to obtain an aqueous dispersion having a heating residue of 40% by weight.

Comparative Example 3 Using the same apparatus as in Example 1, the same amount of polyethylene glycol (molecular weight 4000) was used in place of the polyoxyethylene diglycolic acid in Example 3, and the acid value was 20 with exactly the same formulation and process. Was obtained. When the resin was emulsified, it became abnormally high in viscosity during the emulsification process and could not be dispersed. Further, a resin obtained by first charging polyethylene glycol and carrying out the same operation could not be emulsified.

Comparative Example 4 In Comparative Example 3, polyethylene glycol (molecular weight 40
The amount of (00) was increased to 25 g, 30 g, 35 g, and 40 g, and the initial charge was made to proceed the condensation reaction to obtain a resin having an acid value of 20. Similarly, when emulsified, when 40 g of polyethylene glycol was charged, emulsification was possible, and an aqueous dispersion having a heating residue of 40% by weight was obtained.

The resins obtained in the above-mentioned Example 3 and Comparative Example 4 were made into paint as follows and tested. White enamel paint formulation Titanium white (rutile type) 50 g Butyl cellosolve 5 g Water 5 g Water dispersion of resin obtained in Examples or Comparative Examples 100 g

The above composition was dispersed in the presence of glass beads using a sand grinder at 1250 rpm for 60 minutes, and the glass beads were removed to obtain white enamel.

Further, 20 g of methylated melamine resin (Melan 620; trade name of Hitachi Chemical Co., Ltd.) was added to the above composition to obtain a white enamel paint.

The white enamel paint thus obtained was diluted with an appropriate amount of water and prepared in a Ford cup # 4 for 30 to 35 seconds. Table 2 shows the test results of the stability of the paint and the characteristics of the coating film.

Test plate preparation conditions Base material: Bonderite # 144-treated steel plate (Nihon Test Panel Co., thickness 0.8 mm) Coating: Air spray (Iwata Weider 61, caliber 1.5 mm),
Air pressure 4kg / cm ² baking; 150 ℃, 20 minutes

Evaluation criteria Hardness: Pencil hardness that does not scratch the coating film Moisture resistance: After leaving at 50 ° C. and 97% relative humidity for 7 days, no blister was generated and evaluated as good. Adhesion: A 1 mm square grid was cut with a cutter, and a peeling test was performed with cellophane tape. Contamination resistance: After applying a magic mark and leaving it for 1 day, it was wiped off with ethanol, and the trace of contamination was visually determined.

[0051]

[Table 2]

[0052]

EFFECTS OF THE INVENTION The resin composition for water-based paints of the present invention is capable of reducing the polyoxyethylene glycol moiety necessary for water solubilization, because the polyoxyethylene diglycolic acid used is uniformly introduced into the alkyd resin. A coating film having excellent paint stability, drying property, water resistance, corrosion resistance, moisture resistance and hardness is obtained.

Claims (2)

[Claims] 1. (a) Oil or fatty acid
0-60 parts by weight, (b) polyhydric alcohol 10-50 parts by weight, (c) monobasic acid 0-25 parts by weight, (d) polybasic acid or its anhydride 10-60 parts by weight, (e) phenol Resin 0 to 40 parts by weight, (f) Epoxy compound 0 to 40 parts by weight and [however, (a) to (f) are 100 parts by weight in total, and the number of hydroxyl groups / the number of carboxyl groups is 1/1 to 1.6 / represented by _{(OCH 2 CH 2) n -O} -CH 2 -COOH (I) [wherein, n is 6 or more integer] - 1 a is] (g) the general formula (I) HOOC-CH ₂ Aqueous paint containing a resin having an acid value of 30 or less obtained by condensation reaction of 1 to 10 parts by weight of polyoxyethylene diglycolic acid [based on 100 parts by weight of the total of (a) to (f)]. Resin composition. 2. (a) Oil or fatty acid
0-60 parts by weight, (b) polyhydric alcohol 10-50 parts by weight, (c) monobasic acid 0-25 parts by weight, (d) polybasic acid or its anhydride 10-60 parts by weight, (e) phenol Resin 0 to 40 parts by weight and (f) epoxy compound 0 to 40 parts by weight are blended in a total amount of 100 parts by weight so that the number of hydroxyl groups / the number of carboxyl groups is 1/1 to 1.6 / 1 and the condensation reaction is carried out. against alkyd resin 100 parts by weight of the resulting Te, (g) the general formula _{(I) HOOC-CH 2 -} (OCH 2 CH 2) n -O-CH 2 -COOH (I) wherein, n represents 6 or more 1 to 10 parts by weight of polyoxyethylene diglycolic acid represented by
Further, a resin composition for an aqueous coating material, which contains a resin having an acid value of 30 or less, which is obtained by a condensation reaction.