JPH01221462A - Resin composition for water-based paint - Google Patents

Abstract

PURPOSE:To obtain the title composition which can be easily made water-soluble and can give a paint film excellent in adhesion, flexibility, impact resistance, etc., by adding a curing agent to a cationized water-based resin formed by adding an acid and water to a specified polyol resin. CONSTITUTION:A curing agent (e.g., blocked isocyanate) is added to a cationized water-based resin formed by adding an acid and water (e.g., aqueous acetic acid solution) to a polyol resin obtained by reacting a high-MW epoxy resin obtained by reacting a (substituted) glycidyl ether compound of a dihydric phenol /alkylene oxide adduct (e.g., a product obtained by effecting an addition reaction of a bisphenol A with ethylene oxide and glycidyl-etherifying the product) with a dihydric phenol with a compound reactive with the epoxy group and capable of being cationized (e.g., diethanolamine). A water-based resin composition for paint which is excellent in solubility in water and can give a paint film markedly excellent in adhesion, flexibility and impact resistance can be obtained.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a cationized resin composition for water-based paints.In particular, the present invention relates to a cationized resin composition for water-based paints. The present invention relates to a coating resin composition having adhesive properties.

[Problems to be solved by conventional techniques and inventions] Conventionally,
The resin composition for water-based paints is based on an epoxy resin obtained from dihydric phenol, especially 2,2-bis(4-hydroxyphenyl)propane (hereinafter referred to as bisphenol A) and epichlorohydrin, and is reacted with a cationizable compound. It is known that the resulting resin is neutralized with acid and made water-soluble with a curing agent and used as a paint, but it has poor solubility in water and the physical properties of the resulting paint film are poor in adhesion. However, it cannot be said that it is possible to form a coating film that is fully satisfactory in terms of flexibility, impact resistance, etc.

[Means to solve the problem]

The present inventors have focused on this point and have conducted intensive research to produce a cationized water-based paint resin from epoxy resin that is easily water-soluble and has improved adhesion, flexibility, impact resistance, etc. As a result, we have arrived at the present invention.

The resin composition for water-based paints of the present invention has a high molecular weight epoxy resin obtained by reacting a substituted or unsubstituted glycidyl ether of an alkylene oxide adduct of dihydric phenol with dihydric phenol, and a high molecular weight epoxy resin that is reactive with epoxy groups. It is characterized by containing a cationized water-based resin obtained by adding an acid and water to a polyol resin obtained by reacting a compound having a cationizable group and a curing agent.

The dihydric phenol mentioned in item 1 refers to a phenol that has one or more aromatic nuclei in its molecule, and the aromatic nucleus is substituted with two hydroxyl groups, and includes mononuclear dihydric phenols and Examples include polynuclear dihydric phenols.

Examples of such mononuclear dihydric phenols include, for example, resorcinol, hydroquinone, pyrocatechol, phloroglucinol, 1,5-dihydroxylnaphthalene, 2
, 7-dihydroxylnaphthalene, 2,6-dihydroxonaphthalene, and the like.

Further, examples of polynuclear dihydric phenols include - formula: (wherein Ar is an aromatic divalent hydrocarbon such as a naphthylene group and a phenylene group, and a phenylene group is preferred for the purpose of the present invention. Y' and Y, may be the same or different and include an alkyl group preferably having up to 4 carbon atoms, such as methyl, n-propyl, n-butyl, n-hexyl, n-octyl; Halogen atoms i.e. chlorine, bromine, iodine or fluorine atoms or alkoxy groups such as methoxy, methoxymethyl, ethoxy, ethoxyethyl, n-butoxy, amyloxy, preferably up to 4 carbon atoms. It is an alkoxy group with

When a substituent other than a hydroxyl group is present on either or both of the above-mentioned aromatic divalent hydrocarbon groups, these substituents may be the same or different. ``and Z is 0 (corresponding to the number of hydrogen atoms in the aromatic ring (^r) that can be substituted by a substituent)
An integer with a value from zero) to a maximum value, which can be the same or different. R8 is, for example, -C-1-〇-1
-S-1j -3O-8-SO2-, or an alkylene group such as a methylene group, an ethylene group, a trimethylene group, a tetramethylene group, a pentamethylene group, a hexamethylene group, a 2-ethylhexamethylene group, an octamethylene group, a nonamethylene group ,
Decamethylene group or alkylidene group such as ethylidene group, propylidene group, isopropylidene group, isobutylidene group, amylidene group, isobutylidene group, 1-phenylethylidene group or cycloaliphatic group such as 1,4-cyclohexylene group, 1, 3-cyclo Hexolef group, cyclohexylidene group, ihahalogenated alkylene group, halogenated alkylidene group, halogenated cycloaliphatic group, alkoxy- and aryloxy-substituted alkylidene group, or alkoxy-
and aryloxy-substituted alkylene groups or alkoxy- and aryloxy-substituted cycloaliphatic groups such as methoxymethylene, ethoxymethylene, ethoxyethyl, 2-ethoxytrimethylene, 3-ethoxypentamethylene, 1.4-(2-methoxycyclohexane) group, phenoxyethylene group, 2-phenoxytrimethylene group, L3-(2-phenoxycyclohexane) group or alkylene group such as phenylethylene group, 2-phenyltrimethylene group, 1-phenyl group Pentamethylene group, 2-phenyldecamethylene group or aromatic group such as phenylene group, naphthylene group or halogenated aromatic group such as 1,4-(2-chlorophenylene)
L 1,4- (2-promphenyle7) group, 1.4
- (2-fluorophenylene) group or alkoxy- and aryloxy-substituted aromatic groups such as L4- (
2-methoxyphenylene) group, 1. ．． 4-(2-ethoxyphenylene) group, ], 4-(2-n-propylphenylene) group, R4-(2-phenoxyphenylene) group or an alkyl-substituted aromatic group such as 1,4-(2-
methylphenylene) group, 1. ．． 4-(2-ethylphenylene) group, 1.4-(2-n-propylphenylene) group, 1.4-(2-n-butylphenylene) group, R4-(
2-n-dodesolphenylene) group, or R is a divalent group such as a divalent hydrocarbon group such as It can be a fused ring, or R1 can be a polyalkoxy group, such as a polyethoxy group, a polypropoxy group, a polythioethyl-giso group, a polybutoxy group, a polyphenylethoxy group, or R1 can be a group containing a silicon atom, such as a polydimethylsiloxy group, a polydiphenylsiloxy group, a polymethylphenylsiloxy group, or R1 can be an aromatic ring, a tertiary-amino group, an ether bond, a carbonyl group, or There are polynuclear dihydric phenols represented by sulfur or two or more alkylene or alkylidene groups separated by a sulfur-containing bond such as a sulfoxide.

Among these polynuclear dihydric phenols, particularly preferred are those of the general formula (wherein Y' and Yl have the same meanings as above, m and 2
is a polynuclear dihydric phenol having a value of 0 to 4, and R5 is preferably an alkylene or alkylidene group having 1 to 3 carbon atoms or a saturated group of the formula %.

Examples of such dihydric phenols include 2,2-bis-(P-hydroxyphenyl)-propane, commonly referred to by the trade name bisphenol A, 2,4'-dihydroxodiphenylmethane, bis-(2-hydroxyphenyl)- methane,
Bis-(4-hydroxyphenyl)-methane, bis-(
4=Hydroxy-2,6-dimethyl-3-methoxyphenyl)-methane, 1.1-bis-(4-hydroxyphenyl)-ethane, 1,2-bis-(4-hydroxyphenyl)-ethane, 1.1- bis-(4-hydroxy-2
-chlorophenyl)-ethane, 1,1-bis-(3,5
-dimethyl-4-hydroxyphenyl)-ethane, 1,
3-bis-=8-(3-methyl-4-hydroxyphenyl)-propane,
2.2-bis-(3,5-dichloro-4-hydroxyphenyl)-propane, 2,2-bis-(3-phenyl-
4-Hydroquinphenyl)-propane, 2,2-bis-
(3-isopropyl-4-hydroxyphenyl)-propane, 2,2-his-(2-isopropyl-4-hydroxyphenyl)-propane, 2.2-bis-(4-hydroxynaphthyl)-propane, 2.2 -bis-(4-hydroxyphenyl)-pentane, 3,3-bis-(4-
hydroxyphenyl)-pentane, 2,2-bis-(4
-hydroxyphenyl)-hebutane, bis-(4-hydroxyphenyl)-methane, bis-(4-hydroxyphenyl)-sochlorohexylmethane, 1,2-bis-(4
-Hydroxyphenyl)-R2-bis-(phenyl)-
Propane, 2,2-bis-(4-hydroxyphenyl)
-bis-(hydroxyphenyl)alkanes such as 1-phenylpropane or 4゜4'-dihydroxybiphenyl, 2,2゛-sich)-roxybiphenyl, 2,4゛-
dihydroxybiphenyl or bis-(4-hydroxyphenyl)-sulfone, such as dihydroxobiphenyl;
2,4'-dihydroxydiphenyl sulpon, chloro-
2,4-'; Hydroxydiphenylsulfone, 5-chloro-4, I'-dihydroxydiphenylsulfone,
Di(hydroxyphenyl)-sulfone or bis-(4-hydroxyphenyl)-ether such as 3'-chloro to 4,4"-dihydroxydiphenylsulfone, 4.
3'-(or 4,2゛- or 2゜2゛-dihydroxo-
diphenyl)ether, 4゜4'-dihydroxy-2,
6-Simethyldiphenyl ether, bis-(4-hydroxy-3-isobutylphenyl)-ether, bis-(
4-Hydroxo-3-isopropylphenyl)-ether, bis-(4-hydroxy-3-chlorophenyl)-
Ether, bis-(4-hydroxy-3-fluorophenyl)-ether, bis-(4-hydroxy-3-bromphenyl)-ether, bis-(4-hydroxynaphthyl)-ether, bis-(4-hydroxy -3-chlornaphthyl)-ether, bis=(2-hydroxybiphenyl)-ether, 4,4″-dihydroxy-2,6
-di(hydroxyphenyl)-ethers such as -cymethoxydiphenyl ether, 4.4"-dihydroxy-2,5-jethoxydiphenyl ether, and 1
, 1-bis-(4-hydroxyphenyl)=2-phenylethane, 1.3.3-)limethyl-1-(4-hydroxyphenyl)-6-hydroxyhensyl, 2,4-
Bis-(p-hydroxyphenyl)-4-methylpentane is also suitable.

Furthermore, another preferred group of polynuclear dihydric phenols has the general formula:
9 alkylidene groups or other alkylene groups, p is 0 to 4), such as 1,4-bis-(4-hydroxyhensyl)-henzene, 1,4-bis-(4-hydroxo hensyl)-tetramethylhensen, 1,4-bis-(4-hydroxyhensyl)-teI-laethylhensen, 1,4-bis-(P-hydroquincumyl)-hensen,],,]3- Examples include bis-ρ-hydroxycumyl)-Hensen.

Other polynuclear dihydric phenols include, for example, initial condensates of phenols and carbonyl compounds (e.g., phenol resin initial condensates, condensation reaction products of phenol and acrolein, phenol and glyogyzal condensation reaction products, phenol condensation reaction products of condensation products with chloromethylxylene), etc.

Further, the alkylene oxide to be subjected to the reaction with the dihydric phenol is, for example, an alkylene oxide having 2 to 4 carbon atoms, and preferable examples include ethylene oxide F, propylene oxide, butylene oxide, and mixtures thereof. can be mentioned.

Thus, the alkylene oxide adduct of dihydric phenol is produced by reacting the dihydric phenol and alkylene oxide in the presence of an alkaline or acidic catalyst.

The ratio of the dihydric phenol to the alkylene oxide is preferably 1 to 10, preferably 1 to 3, per hydroxyl group of the dihydric phenol.

The alkylene oxide adduct of dihydric phenol thus obtained is then subjected to a reaction with one selected from epihalogenohydrin, methyl epihalogenohydrin, and dihalogenohydrin in the presence of an alkali hydroxide catalyst. , to give a substituted or unsubstituted glycidyl ether compound.

Examples of epihalogenohydrin, methylepihalogenohydrin, and dihalogenohydrin include epichlorohydrin, shrimp bromohydrin, methylepichlorohydrin,
Examples include methylebibromohydrin, dibromohydrin, and dibromohydrin, among which epichlorohydrin, ebibromohydrin, and methylepichlorohydrin are preferably used.

Here, the alkylene oxide adduct of dihydric phenol, epihalogenohydrin, methyl epihalogenohydrin,
The reaction rate with one type selected from dihalogenohydrins is
The latter is preferably 1 to 20 moles per 1 mole of the former, and the epoxy equivalent of the substituted or unsubstituted glycidyl ether compound obtained is preferably 200 to 600.

Furthermore, a high molecular weight epoxy resin can be obtained by reacting a substituted or unsubstituted glycidyl etherified product with a dihydric phenol at a temperature of 80 to 250'C in the presence of a catalyst. The epoxy equivalent of the obtained high molecular weight epoxy resin is 10
00-4000 is preferable.

Here, the dihydric phenol mentioned above may be any of the dihydric phenols exemplified as the dihydric phenol that can be used in the production of the alkylene oxide adduct of the dihydric phenol.

In addition, the catalysts used for this reaction include caustic soda,
Inorganic alkalis such as caustic potash and soda carbonate, tertiary amines such as triethylamine, triethanolamine, dimethylamine, and pyridine, imidazoles, quaternary ammonium salts such as tetramethylammonium chloride, boron trifluoride, and aluminum chloride. , Lewis acids such as tin tetrachloride, titanium tetrachloride, and the like.

Further, the reaction ratio between the substituted or unsubstituted glycidyl etherified product and the dihydric phenol is arbitrarily determined so that the high molecular weight epoxy resin has a preferable epoxy equivalent.

The compound used in the present invention that is reactive with an epoxy group and has a cationizable group is -15=, which is a compound that has a group that is reactive with an epoxy group and a cationizable group. Any primary amines such as methylamine, ethylamine, propylamine, butylamine, dimethylamine, diethylamine, dipropylamine, dibutylamine, methylbutylamine or secondary amines such as ethanolamine, propylamine, etc. can be used. Hydroxylamines such as toolamine, jetanolamine, diisoproptoolamine, other amine compounds such as piperazine, N-methylbiperazine, etc., such as diethyl sulfide, dipropyl sulfide, dibutyl sulfide, diphenyl sulfide, synclohexyl sulfide, tetramethylene sulfide , thiogentanol, thiodibrobanol, sulfides such as succinic anhydride, phthalic anhydride,
Amines containing a carboxyl group such as those obtained by reacting an acid anhydride such as maleic anhydride with an alkanolamine such as dimethylethanolamine or methyljetanolamine, for example, at least one of the organic groups is substituted with an amino group. Examples include phosphine compounds such as trimethylphosphine, triethylphosphine, diphenylmethylphosphine, etc. Among these, preferred are water-soluble amine compounds, and particularly preferred are hydroxylamine containing a hydroxyl group. be.

The reaction between a high molecular weight epoxy resin and a compound that is reactive with epoxy groups and has a cationizable group can occur even if they are mixed at room temperature, but in order to complete the reaction, it is necessary to Preferably, heating is performed at 70 to 100°C.

A compound that is reactive with an epoxy group and has a cationizable group has a ratio of groups that are reactive with an epoxy group to epoxy groups in the reaction product of 0.
．． It is preferable to use an amount of 2 to 1.0, preferably 0.5 to 1.0, and it is preferable to add it gradually to the reaction product to prevent sudden heat generation. In order to facilitate the reaction, a solvent may be used, and examples of such solvents include alcohols such as isopropanol, isobutanol, and ethyl cellosolve; In addition to the solvent-based solvents, various solvents can be used.

The thus obtained polyol resin of the present invention can be mixed with an aqueous liquid containing an organic acid such as formic acid, acetic acid, propionic acid, or lactic acid, or an inorganic acid such as phosphoric acid, hydrochloric acid, boric acid, or sulfuric acid. It can be made into an aqueous emulsion or an aqueous solution of a coating resin, and can be a cationized water-based resin.

In addition, when reacting a compound that is reactive with the above-mentioned epoxy group and has a cationizable group, the above-mentioned acid is added at the same time, and after the reaction is completed, water is added to react in the same manner. It can also be an aqueous emulsion or solution of a coating resin. The amount of acid is preferably at least the amount necessary for solubilizing or dispersing the resin in water, and less than the equivalent of the cationizable group contained in the resin.

The cationized water-based resin of the present invention obtained in this way can be used in combination with various curing agents to coat the object to be coated by coating, dipping, electrodeposition, etc., and then cured, resulting in excellent adhesion. , provides a coating film with flexibility and corrosion resistance.

As curing agents, for example blocked isocyanates and partially capped organic polyisocyanamino resins can be used, with blocked isocyanates and partially capped organic polyisocyanamino resins being particularly preferred.

The above-mentioned pronoquisocyanate is a product obtained by reacting a hydroxyl group-containing compound with an isocyanate monomer such as tolylene diisocyanate, xylylene diisocyanate, and isophorone diisocyanate. Isocyanate of compounds with more isocyanate groups
Examples include those in which the - group is blocked with phenol, methyl ethyl ketone, oxime, methanol, etc.

In addition, the amine resins used in the present invention include, for example, urea resins obtained by a condensation reaction of urea and formaldehydes (mainly formaldehyde), thiourea resins using thiourea instead of urea, and melamine and formaldehyde resins. Examples include melamine resins obtained by reacting guanamine with formaldehydes, guanamine resins obtained by reacting guanamine with formaldehydes, and/or co-condensed resins thereof. Furthermore, those obtained by methylating or butylating these with an aliphatic alcohol such as evaporated methyl alcohol or butyl alcohol can also be used.

The blending amount of the curing agent is 2 to 100 parts by weight of the water-based resin.
50 parts by weight is preferred.

The polyol resin of the present invention can be solubilized or dispersed in water without the need for a surfactant, but a surfactant may be used in some cases, and a solvent can be used as long as it has an affinity for water. You may. When the aqueous resin of the present invention is used with various curing agents, for example, tertiary amines, alkyl metal salts, etc. can be used as curing accelerators in order to achieve more rapid and complete curing.

Further, the composition of the present invention may be used with a pigment added thereto, and the pigment is preferably one that does not have reactivity with acids.

It is also possible to mix other neutral or cationic resins within a range that is compatible with the composition of the present invention.

The water-based paint resin composition obtained by the present invention has excellent solubility in water compared to conventional cationizable paint resins, and provides coatings with excellent adhesion, flexibility, and impact resistance. Give a membrane.

[Examples] The present invention will be explained below with reference to production examples and examples, but the present invention is not limited to these examples. In addition, "part" in an example means 1 part by weight.

Production Example 1 Liquid epoxy resin obtained by adding ethylene oxide to bisphenol A and converting it into glycidyl ether (epoxy equivalent -
510) Add 150 parts of bisphenol A, 15 parts of bisphenol A, and dimethylamine as a catalyst, and continue heating and stirring at 180°C for 15 hours.

The obtained high molecular weight epoxy resin has an epoxy equivalent of 105
It was 0. Furthermore, 740 parts of Methyl Isobutyl Ke I and 12 parts of jetanolamine were added and stirred at 80°C for 33 hours to obtain polyol resin (1).

After that, lower the temperature to 50'C, gradually add 110 parts of 10% acetic acid, stir, and when it becomes homogeneous, add 30 parts of distilled water.
0 parts was added to obtain a cationized water-based resin (1-A).

Production Example 2 Sodium hydroxide was added as a catalyst to 150 parts of a liquid epoxy resin (epoxy equivalent: -360) obtained by adding propylene oxide to bisphenol F and glycidyl etherification and 33 parts of bisphenol F, and the mixture was heated and stirred at 150°C for 18 hours. .

The obtained high molecular weight epoxy resin has an epoxy equivalent of 180
It was 0. Further, 40 parts of methyl ethyl ketone and 13 parts of dibutylamine were added and stirred at 100°C for 2 hours to obtain polyol resin (II). Thereafter, the temperature was lowered to 50'C, 105 parts of 10% acetic acid was gradually added and stirred, and when the mixture became homogeneous, 450 parts of distilled water was added to obtain a cationized water-based resin (Il-A).

Production Example 3 Sodium hydroxide was added as a catalyst to 150 parts of a liquid epoxy resin (epoxy equivalent -410) obtained by adding propylene oxide to bisphenol A and glycidyl etherification (epoxy equivalent: -410) and 35 parts of bisphenol A, and the mixture was heated and stirred at 200°C for 10 hours. .

The obtained epoxy resin had an epoxy equivalent weight of 3,400. Furthermore, 72,740 parts and 6 parts of diisopropanolamine were added and stirred at 110°C for 2 hours to obtain a polyol resin (
III) was obtained. Then lower the temperature to 50°C for 10
% acetic acid was gradually added and stirred, and when the mixture became homogeneous, 450 parts of distilled water was added to obtain a cationized water-based resin (TI[-A).

Production Example 4 Sodium hydroxide was added as a catalyst to 150 parts of Asahi Denka Kogyo's Adeka Resin EP-4100 (epoxy equivalent: -190) obtained from bisphenol A and epichlorohydrin and 65 parts of bisphenol A, and the mixture was heated and stirred at 180°C for 5 hours. .

The obtained epoxy resin had an epoxy equivalent weight of 980. Further, 200 parts of methyl isobutyl ketone and 23 parts of jetanolamine were added and stirred at 80°C for 3 hours to obtain polyol resin (IV). Thereafter, the temperature was lowered to 50'C, 220 parts of 10% acetic acid was gradually added and stirred, and when the mixture became homogeneous, 295 parts of distilled water was added to obtain a cationized water-based resin (■-A).

Production Example 5 Dimethylamine was added as a catalyst to 150 parts of Asahi Denka Kogyo's Adeka Resin EP-4900 (epoxy equivalent: -180) obtained from bisphenol F and epichlorohydrin and 70 parts of bisphenol F, and the mixture was heated and stirred at 200°C for 10 hours.

The obtained epoxy resin had an epoxy equivalent weight of 1,700. Additionally, 727,200 parts and 1 part of diisopropanolamine
8 parts were added and stirred at 100°C for 2 hours to obtain polyol resin (V). Then lower the temperature to 50°C for 10
% acetic acid was gradually added and stirred, and when the mixture became homogeneous, 315 parts of distilled water was added to obtain a cationized water-based resin (VA).

Examples 1 to 4, Comparative Examples 1 to 3 Various water-based resins and curing agents obtained in the above production examples were mixed in the formulations shown in Table 1, and cured under the conditions shown below. The coating performance is shown in Table 1.

Baking conditions: 200°C for 5 minutes Film thickness: 8~10μ

Claims (1)

[Claims] 1. Alkylene oxide adduct of dihydric phenol,
A high molecular weight epoxy resin obtained by reacting a dihydric phenol with a substituted or unsubstituted glycidyl ether compound, and a polyol resin obtained by reacting a compound having a cationizable group that is reactive with an epoxy group. , a cationized water-based resin prepared by adding an acid and water, and a curing agent. 2. The resin composition for water-based coatings according to claim 1, wherein the curing agent is a curing agent consisting of one compound selected from blocked isocyanates, partially capped organic polyisocyanates, and amino resins.