JP2002294027A - Aqueous resin composition and aqueous paint - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an aqueous resin composition excellent in hardening property, water resistance, processability, hardness, etc., using a commercially available less expensive material and containing an amino resin having high generality as an essential component, and an aqueous paint. SOLUTION: The aqueous resin composition containing an amino resin (A) obtained by condensing (a) a triazine compound with (b) an aldehyde carboxylic acid and/or hydroxybenzaldehyde as an aldehyde compound. An aqueous paint containing the composition.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an aqueous resin composition and an aqueous paint containing a specific amino resin whose aldehyde component is aldehyde carboxylic acid and / or hydroxybenzaldehyde. The present invention relates to an aqueous resin composition and an aqueous paint further containing a water-soluble or water-dispersible resin. The aqueous resin composition and aqueous paint of the present invention are particularly useful as binders or additives for paints, paper processing, fiber processing, adhesion, ink, and other coating applications.

[0002]

2. Description of the Related Art From the viewpoint of environmental protection and the like, it is required to reduce the amount of organic solvent discharged during a coating process, and a conventional solvent type paint is being converted to a water-based paint. For such an aqueous coating, for example, an aqueous resin composition containing a methylated amino resin or an alkyl etherified amino resin as an amino resin having thermal crosslinking properties is generally used. Since these amino resins are generally insoluble in water, U.S. Pat. Nos. 3,464,946 and 3,444,114 disclose alkyl ethers which are made aqueous with oxycarboxylic acids. Amino resins are disclosed.

[0003] However, these resins are water-resistant,
It has the drawback that processability and hardness are insufficient, and it is not possible to obtain a highly practical paint having satisfactory performance, that is, a cured coating film. Therefore, in order to solve the above-described problems, aqueous alkylation of a low molecular weight benzoguanamine resin or the like as an alkyl etherified amino resin has been attempted, and practical use of an aqueous paint for a can outer surface has been attempted.
Since these low molecular weight alkyl etherified amino resins are inferior in water dilutability, the combined use of an organic solvent is inevitable, and it is difficult to reduce the amount of the organic solvent.

It is known that the dispersion state of an aqueous resin composition comprising an aqueous resin dispersion is destroyed by the addition of an organic solvent, and the aqueous resin composition is prepared by an emulsion polymerization method using water as a dispersion medium. It is difficult to produce an aqueous resin composition by combining the body with an aqueous low-molecular-weight benzoguanamine resin containing the above organic solvent. Accordingly, there is a disadvantage that it is impossible to mix a sufficient amount of the alkyl etherified amino resin with the aqueous resin dispersion in order to exhibit various properties of the aqueous resin composition. Like this
In the prior art, there was naturally a limitation in developing an aqueous resin composition containing an alkyl etherified amino resin into an aqueous paint.

[0005] The inventors of the present invention have proposed, as disclosed in Japanese Patent Application Laid-Open No. 9-208821, to improve the performance of various coatings required for such an aqueous resin composition, especially an aqueous coating. 3- or 4- (4,6-diamino-1,
A water-based resin composition and a water-based paint containing an amino resin composed of 3,5-triazin-2-yl) -benzoic acid as an essential component have been proposed. However, 2-, 3- or 4- (4,6-diamino-1,3,5-triazine-
2-yl) -benzoic acid is expensive in price and is difficult to use for general-purpose applications. Therefore, melamine and benzoguanamine are used in combination at the expense of water solubility and physical properties to reduce cost and use for general-purpose applications. Had disadvantages.

[0006]

The problem to be solved by the present invention is to use a commercially available inexpensive material which is excellent in curability, water resistance, workability and hardness.
An object of the present invention is to provide an aqueous resin composition and an aqueous paint containing a highly versatile amino resin as an essential component.

[0007]

Means for Solving the Problems As a result of intensive studies, the present inventors have found that a specific amino resin whose aldehyde component is aldehyde carboxylic acid and / or hydroxybenzaldehyde is a desirable water-soluble substance or water-dispersed substance. To complete the present invention.
That is, the present invention further provides an aqueous resin composition containing an amino resin whose aldehyde component is aldehyde carboxylic acid and / or hydroxybenzaldehyde, and a water-soluble or water-dispersible resin containing a group reactive with the amino resin. It is an object of the present invention to provide an aqueous resin composition containing the same, and an aqueous paint using the same.

Specifically, the present invention comprises (1) an amino resin (A) obtained by condensing (a) a triazine compound with (b) an aldehyde carboxylic acid and / or hydroxybenzaldehyde as an aldehyde compound. An aqueous resin composition is provided.

The present invention also provides (2) an aqueous paint containing the aqueous resin composition of the above (1).

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in more detail. The amino resin (A) used in the aqueous resin composition of the present invention comprises (a) a triazine compound,
(B) It can be obtained by condensing an aldehyde compound with an aldehyde carboxylic acid and / or hydroxybenzaldehyde.

The triazine compound (a) used in the present invention is not particularly limited as long as it is an amino compound having a triazine skeleton. Guanamine, 2-, 3- or 4- (4,6-diamino-1,
3,5-triazin-2-yl) benzoic acid, 2-, 3-
Or 4- (4,6-diamino-1,3,5-triazin-2-yl) -phenol. Among them,
Melamine, benzoguanamine, 2-, 3- or 4-
(4,6-Diamino-1,3,5-triazin-2-yl) benzoic acid is preferred, and melamine and benzoguanamine are particularly recommended in terms of price.

In the present invention, an aldehyde compound (b) having a carboxyl group or a phenolic hydroxyl group is an essential component. Although there is no particular limitation on these aldehyde compounds, glyoxylic acid,
Aldehyde carboxylic acids, such as succin semialdehyde, hydroxybenzaldehyde are recommended. These can also be used in the form of an aqueous solution.

The amino resin of the present invention can be used not only by the condensation of a single amino compound and a single aldehyde compound but also by mixing several kinds of each.
In this case, it is sufficient that at least one of the aldehyde compounds used contains at least one carboxyl group or phenolic hydroxyl group. For example, benzoguanamine and melamine can be mixed in a desired ratio and condensed with a mixture of glyoxylic acid and formaldehyde in a desired ratio. By using a plurality of amino compounds and / or aldehyde compounds as raw materials, the acid value of the obtained amino resin can be adjusted, which is preferable.

The amino resin of the present invention is obtained by condensing (a) a triazine compound with (b) an aldehyde carboxylic acid and / or hydroxybenzaldehyde as an aldehyde compound, and simultaneously performing an etherification reaction using a monohydric alcohol for etherification. Can also be obtained.

The alcohol for etherification used herein is useful for improving the storage stability of the aqueous resin composition containing the amino resin of the present invention. These one
Although it does not specifically limit as a valent alcohol, For example, methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, sec-butanol, tert-butanol, cyclohexanol, n-pentanol, isopentanol, methyl isobutyl Various alcohols having 1 to 8 carbon atoms such as carbinol, benzyl alcohol, furfuryl alcohol, n-octanol, sec-octanol, 2-ethylhexyl alcohol or allyl alcohol;

Or ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, ethylene glycol monoisobutyl ether, ethylene glycol mono-te
rt-butyl ether, ethylene glycol mono-is
o-propyl ether, ethylene glycol monohexyl ether, 3-methoxybutanol, 3-methyl-3
Various ether alcohols, such as methoxybutanol, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, propylene glycol monomethyl ether or dipropylene glycol monomethyl ether;

Alternatively, various ketone alcohols such as ketobutanol, diacetone alcohol and acetoin can be mentioned. These can be used alone,
It goes without saying that two or more kinds may be used in combination. Among them, methanol, ethanol, n-propanol, isopropanol, n-butanol and isobutanol are particularly preferably used in view of reactivity, cost, crosslinkability of the obtained amino resin, and the like.

In order to obtain the amino resin (A) used in the present invention, for example, JP-A-9-143169, JP-A-8-176249, JP-A-9-20
No. 8821, JP-A-10-140015, etc., the aldehyde compound (b) is used in an amount of 1.5 to 1.5 mol per (a) triazine compound.
These raw materials may be reacted at a ratio of 8 moles and a ratio of the monohydric alcohol for etherification of 3 to 20 moles. At this time, a known and commonly used solvent can be used.

In order to prepare the component (A), various known and common production methods can be used. That is, for example, (1) a triazine compound is added to a solution obtained by adding an aldehyde compound to a monohydric alcohol for etherification to about 50 to 1 in the presence of an acidic catalyst, if necessary.
A method of reacting at a temperature of 40 ° C. for 20 minutes to 7 hours to simultaneously carry out a condensation reaction and an etherification reaction;

(2) The solution obtained by adding the aldehyde compound and the triazine compound is methylolated in a pH range of about 8 to 10, and then in the presence of a monohydric alcohol for etherification in a pH range of about 2 to 6. Alkyl etherification within

(3) A solution obtained by adding an aldehyde compound to a monohydric alcohol for etherification is first added to at least one selected from the group consisting of melamine, benzoguanamine, acetoguanamine, cyclohexanecarboguanamine, phthaloguanamine, steroganamin and spiroguanamine. A method of adding one compound and adding (4,6-diamino-1,3,5-triazin-2-yl) benzoic acid during the condensation reaction and the etherification reaction;

(4) The monohydric alcohol for etherification includes at least glyoxylic acid, succin semialdehyde,
One compound selected from the group consisting of 2-, 3- or 4-hydroxybenzaldehyde and formaldehyde,
At least one compound selected from the group consisting of paraformaldehyde, acetaldehyde, propionaldehyde, butyraldehyde, and glyoxal is added, and then melamine, benzoguanamine, acetoguanamine, cyclohexanecarboguanamine, phthaloguanamine, steloguanamine, spiroguanamine, ( 4,6-
A method of adding at least one compound selected from the group consisting of diamino-1,3,5-triazin-2-yl) benzoic acid and performing a condensation reaction and an etherification reaction. Etc. can be applied.

When two or more triazine compounds and / or aldehyde compounds are used in combination, the ratio is not particularly limited, but the acid value of the amino resin is 20 to 250 mg KO.
It is preferable to adjust the composition so as to be in the range of H / g.

The amino resin (A) of the present invention can be used as it is, but when it contains the water-soluble or water-dispersible resin (B), it may be better to make it aqueous. . In this case, the carboxyl group and / or phenolic hydroxyl group introduced into the amino resin can be replaced with various volatile bases such as ammonia or an aliphatic amine.
It is completely neutralized or partially neutralized and dissolved or dispersed in water or a mixture of water and a water-soluble solvent for use.

The aliphatic amine used here is not particularly limited, but typical examples thereof include, for example, monomethylamine, dimethylamine, monoethylamine, diethylamine and triethylamine.
Various alkylamines; various such as typified by N-methylaminoethanol, N, N-dimethylaminoethanol, N, N-diethylaminoethanol, 2-amino-2-methylpropanol, diethanolamine or triethanolamine; Hydroxylamines; and various polyamines represented by ethylenediamine or diethylenetriamine. These may be used alone or in combination of two or more.

The amino resin (A) may be converted to an aqueous solution by a known and common means such as heating or distillation under reduced pressure.
The remaining unreacted monohydric alcohol for etherification and various organic solvents used for the synthesis or aqueousization of the amino resin (A) are
After azeotropic removal with water, the carboxyl group and / or phenolic hydroxyl group introduced into the amino resin (A) is completely or partially neutralized with ammonia or an aliphatic amine to obtain water or It may be dissolved or dispersed in a mixture of water and a water-soluble solvent.

As the water-soluble solvent used herein, known and commonly used solvents can be used. For example, various ketones such as dimethyl ketone, methyl ethyl ketone and diacetone alcohol; ethylene glycol monomethyl ether, ethylene glycol dimethyl ether, ethylene glycol Glycol monoethyl ether, ethylene glycol diethyl ether, ethylene glycol mono (iso) propyl ether, ethylene glycol mono (iso) butyl ether, ethylene glycol mono-tert-butyl ether, ethylene glycol mono (iso) propyl ether, ethylene glycol monohexyl ether,
1,3-butylene glycol-3-monomethyl ether or 3-methyl-3-methoxybutanol, diethylene glycol monomethyl ether, diethylene glycol dimethyl ether,

Various ether alcohols or ethers such as diethylene glycol monoethyl ether, diethylene glycol diethyl ether, diethylene glycol monobutyl ether, triethylene glycol dimethyl ether, propylene glycol monomethyl ether, propylene glycol dimethyl ether or dipropylene glycol monomethyl ether or dipropylene glycol dimethyl ether Various esters or ether esters such as ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate or 1-methoxy-2-propyl acetate; methanol, ethanol,
(Iso) propanol, sec-butanol, tert
-Various alcohols, such as butanol or furfuryl alcohol. These may be used alone or in combination of two or more.

Depending on the composition and the amount of the water-soluble or water-dispersible resin (B) to be combined, the resin or the water-soluble solvent may be further dissolved or dispersed using a hardly water-soluble solvent or a water-insoluble solvent in addition to water. Sometimes it is better.

The poorly water-soluble or water-insoluble solvent used at this time includes methyl isobutyl ketone, 2,6-dimethyl-4-heptanone, 2-octanone, methyl amyl ketone, cyclohexanone or 3,5,5-trimethyl-2- Various ketones such as cyclohexen-1-one; n-butanol, isobutanol, 1-pentanol, isoamyl alcohol, 2-ethylhexanol,
Various alcohols such as 4-methyl-2-propanol, benzyl alcohol or furfuryl alcohol;

Methyl acetate, ethyl acetate, n-propyl acetate, isopropyl acetate, n-butyl acetate, isobutyl acetate, isoamyl acetate, ethylene glycol monobutyl ether acetate, methyl-1,3-butylene glycol acetate, diethylene glycol monobutyl ether acetate, -Methyl-3-methoxybutyl acetate or ethyl 3-ethoxypropionate, propylene glycol monomethyl ether acetate, propylene glycol monobutyl ether, propylene glycol mono (iso) propyl ether, dipropylene glycol monobutyl ether or tripropylene glycol monobutyl ether or propylene glycol Various esters, ethers and ethers, such as phenyl ether Ester compounds; or toluene, xylene, cyclohexane, n- hexane, octane, such as mineral spirits or petroleum-based mixed solvent, such as various hydrocarbon-based solvent.

The aqueous solution is prepared by completely or partially neutralizing a carboxyl group and / or a phenolic hydroxyl group introduced into the amino resin (A) with ammonia or an organic amine or the like, followed by stirring. A method in which water is gradually dropped to dissolve or disperse in water, and a method in which fully neutralized or partially neutralized amino resin (A) is gradually dropped into water under stirring. Can be Usually, a method of dissolving or dispersing in water by gradually dropping water while stirring the fully neutralized or partially neutralized amino resin (A) at a temperature of about 60 ° C. or less at a high speed. desirable.

In addition, when making the aqueous solution, it is possible to use a known and commonly used homomixer or homogenizer and to use a method of giving a mechanical shearing force in combination, which is desirable for obtaining a stable aqueous amino resin. Method. In addition, a method of making water-based by applying ultrasonic waves is also a desirable method. The water-soluble amino resin (A) thus obtained has good water dilutability, and furthermore, a water-insoluble amino resin (A) can be obtained.

The water-soluble or water-dispersible resin (B) used in the present invention is not particularly limited, and various known and commonly used resins can be used. Specific examples thereof include an aqueous acrylic resin, an aqueous polyester resin, an aqueous alkyd resin, an aqueous epoxy ester resin and an aqueous urethane resin. Such a water-soluble or water-dispersible resin can be appropriately selected and used according to the purpose of use and the required performance of the aqueous resin composition of the present invention.

Above all, a water-soluble or water-dispersible resin (B) containing a group reactive with the amino resin (A) is preferred from the viewpoints of curability of the coating film, water resistance and hardness of the cured coating film, and the like. Such resins include carboxyl groups on the side chains,
Having a hydrophilic group such as a carboxylate, sulfonic acid group, sulfonic acid salt, hydroxyl group or polyether group;
Aqueous acrylic resins which also have a so-called cross-linking functional group such as an alkoxyalkyl-substituted amide group. It is particularly desirable that the hydrophilic group has at least a carboxyl group or a carboxylate.

These aqueous acrylic resins can be prepared by, for example, subjecting a monomer mixture comprising a carboxyl group-containing vinyl monomer, a functional group-containing vinyl monomer for crosslinking, and other vinyl monomers copolymerizable therewith to a radical mixture in an organic solvent. Due to the polymerization reaction, the number average molecular weight is about 1,000.
To obtain a copolymer in the range of 0 to 30,000;
If necessary, excess organic solvent is distilled off from the copolymer solution under reduced pressure, and then the carboxyl group is completely or partially neutralized with a volatile basic compound such as ammonia or an aliphatic amine. And a mixture with the above-mentioned water-soluble solvent.

An aqueous acrylic resin having a low organic solvent content is prepared by distilling the organic solvent together with water from the aqueous acrylic resin containing an organic solvent, ie, the aqueous acrylic resin solution prepared as described above. Resin can also be obtained.

As the carboxyl group-containing vinyl monomer used at this time, for example, acrylic acid, methacrylic acid, maleic acid, fumaric acid and the like can be mentioned, and among them, acrylic acid or methacrylic acid is preferable. The amount of the carboxyl group-containing vinyl monomer used is in the range of 1 to 25% by weight, preferably 2 to 20% by weight of the total amount of the monomers.

The vinyl monomer having a functional group for crosslinking used at this time includes N-methoxymethyl (meth) acrylamide, N-ethoxymethyl (meth) acrylamide, N-isobutoxymethyl (meth) acrylamide or N-methoxymethyl (meth) acrylamide. N-alkoxyalkyl-substituted amide group-containing vinyl monomers such as -n-butoxymethyl (meth) acrylamide, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, Examples include hydroxyl group-containing vinyl monomers such as hydroxypentyl (meth) acrylate and hydroxyhexyl (meth) acrylate. The amount of the N-alkoxyalkyl-substituted amide group-containing vinyl monomer is from 2 to 6
0% by weight, preferably 5 to 50% by weight.

Examples of other vinyl monomers copolymerizable with the carboxyl group-containing vinyl monomer and the functional group-containing vinyl monomer for crosslinking include:
Methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, tert-butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate,
Lauryl (meth) acrylate, stearyl (meth) acrylate, methoxypolyethylene glycol (meth)
Acrylate, cyclohexyl (meth) acrylate,
Various (meth) acrylates, such as tetrahydrofurfuryl (meth) acrylate, isobornyl (meth) acrylate, 2- (meth) acryloyloxyethyl acid phosphate or benzyl (meth) acrylate;

Various aromatic vinyl monomers such as styrene, vinyltoluene or α-methylstyrene; various aromatic vinyl monomers such as dimethyl maleate, dibutyl maleate, dimethyl fumarate, dibutyl fumarate, dimethyl itaconate or dibutyl itaconate; And divinyl esters of unsaturated dibasic acids; or various vinyl carboxylate esters such as vinyl acetate, vinyl propionate, vinyl pivalate or vinyl versatate.

As the water-soluble or water-dispersible resin (B), the above acrylic resin such as an acrylic resin-modified alkyd resin, an acrylic resin-modified epoxy resin, an acrylic resin-modified urethane resin or an acrylic resin-modified polyester resin is modified. A modified acrylic resin can also be used.

In order to prepare these modified acrylic resins, various known and commonly used production methods can be employed. For example, as a method for preparing an acrylic resin-modified alkyd resin, (1) a method of radically polymerizing the vinyl monomer described above in the presence of an alkyd resin using tetrahydrophthalic anhydride to carry out acryl grafting,
(2) A method of adding a monomer having a glycidyl group and a vinyl group such as glycidyl methacrylate to a carboxyl group of an alkyd resin synthesized in advance, and radically polymerizing the above-described vinyl monomer in the presence thereof.

For example, as a method for preparing an acrylic resin-modified epoxy resin, (1) a method of radically polymerizing the above-described vinyl monomer in the presence of an epoxy resin and grafting an acrylic copolymer to an epoxy resin skeleton. Or (2) a high acid value acrylic resin is synthesized in advance, and then, in the presence of a tertiary amine, the epoxy group of the epoxy resin and a part of the carboxyl group of the acrylic resin are reacted to obtain a graft polymer. And a method of making aqueous with a residual carboxyl group.

The water-soluble or water-dispersible resin (B) used in the present invention has a solid content acid value of 10 to 200.
Used in When the acid value is less than 10, it is difficult to form an aqueous solution, while when the acid value exceeds 200, the water resistance tends to be poor.

The use ratio of the amino resin (A) of the present invention and the water-soluble or water-dispersible resin (B) may be in any range as long as the effects of the present invention are exhibited. Usually, the weight ratio of (A) / (B) is from 5/95 to 7 based on the resin solid content of the obtained aqueous resin composition.
The range of 0/30 is preferred, and the range of 10/90 to 60/40 is most preferred. Within this range, the effects of the present invention can be further exhibited. (A) is 5
When the amount is less than% by weight, the crosslink density becomes low, and thus the hardness and water resistance of the resulting coating film, particularly the retort resistance, are likely to be inferior. On the other hand, when the content of (A) is higher than 70% by weight, the flexibility and the like of the coating film are likely to be inferior, so that any case is not preferable.

The aqueous resin composition of the present invention can be suitably used as an aqueous paint. At this time, a general-purpose catalyst,
Various additives commonly used for paints, such as pigments, leveling agents, antifoaming agents, lubricants, pigment dispersants, anti-sagging agents, anti-segregation agents, matting agents, ultraviolet absorbers or anti-aging agents are compounded. be able to. When these additives are used, they can be applied by using various known or common mixing or milling methods. For example, roll mill, sand mill,
A ball mill or paint mixer can be used.

Examples of the catalyst include various sulfonic acid catalysts such as p-toluenesulfonic acid, dodecylbenzenesulfonic acid and dinonylnaphthalenedisulfonic acid;
Various phosphoric acid-based catalysts such as phosphoric acid, phosphoric acid methyl ester, phosphoric acid ethyl ester or butyl phosphate ester; or amine salts thereof blocked with a volatile basic compound such as ammonia or an aliphatic amine. The curing catalyst can be blended within a range of usually 0.1 to 1.0 part by weight based on 100 parts by weight of the resin solid content.

The aqueous paint of the present invention can be prepared by, for example, a dipping method,
It can be applied by various known and common methods such as brushing, spray coating or roll coating, and
It can be coated on the surface of various base materials such as wood, paper, fiber, plastic, ceramics, inorganic cement base, iron or non-ferrous metal, etc. to give excellent various performances.

The water-based coating composition of the present invention is usually used in an amount of about 80 to 30.
By performing the baking treatment in a temperature range of 0 ° C. for about 5 seconds to 30 minutes, it is possible to form a cured film having excellent various properties and extremely high practicality.

The water-based paint of the present invention thus obtained is
In particular, it can be used for coating general metal materials, metal products, or PCM (pre-coated metal). In particular, it is useful for beverage cans or food cans such as metal cans or film-laminated cans.

[0052]

Next, the present invention will be described specifically with reference to Synthesis Examples, Examples and Comparative Examples, but the present invention is not limited to only these illustrative examples. In the following,%
Are based on weight unless otherwise noted.

Synthesis Example 1 [Preparation Example of Amino Resin (A) Having Carboxyl Group] Benzoguanamine was placed in a four-necked flask equipped with a stirrer, thermometer, Dean Stark, and nitrogen gas inlet tube.
4 g (0.2 mol), 118.4 g (0.8 mol) of glyoxylic acid (50 wt% aqueous solution) and 88.8 g (1.2 mol) of n-butanol were charged, and the temperature was raised to 115 ° C. while stirring. did. After reaching the same temperature, the reaction solution became homogeneous within 10 minutes. One hour after reaching the reaction temperature, the reaction was continued for another 4 hours while distilling off water under a reduced pressure of 5.33 × 10 ⁴ Pascal.

Thereafter, ethylene glycol monobutyl ether was added thereto, and n-butanol was distilled off under reduced pressure. After cooling, ethylene glycol monobutyl ether was added to reduce the nonvolatile content to 60% to obtain a butyl etherified amino resin solution. . Hereinafter, this is abbreviated as amino resin (A-1). The acid value of the amino resin solid is 136 mgKOH /
g, number average molecular weight in terms of polystyrene; Mn is 1
624, the degree of dispersion; Mw / Mn was 1.28.

Synthesis Example 2 [Preparation Example of Amino Resin (A) Having Carboxyl Group] Benzoguanamine was placed in a four-necked flask equipped with a stirrer, a thermometer, a Dean Stark, and a nitrogen gas inlet tube.
4 g (0.2 mol), 118.4 g (0.8 mol) of glyoxylic acid (50 wt% aqueous solution) and 88.8 g (1.2 mol) of n-butanol were charged, and the temperature was raised to 115 ° C. while stirring. did. After reaching the same temperature, the reaction solution became homogeneous within 10 minutes. One hour after reaching the reaction temperature, the reaction was continued for another 4 hours while distilling off water under a reduced pressure of 5.33 × 10 ⁴ Pascal.

Thereafter, the pH was adjusted to 8.0 with N, N-dimethylethanolamine. Next, ethylene glycol monobutyl ether was added thereto, and n-butanol was distilled off under reduced pressure. After cooling, ethylene glycol monobutyl ether was added to reduce the nonvolatile content to 60%, thereby obtaining a butyl etherified amino resin solution. Hereinafter, this is abbreviated as amino resin (A-2). The acid value of the amino resin solid is
138 m before neutralization with N, N-dimethylethanolamine
gKOH / g, polystyrene-equivalent number average molecular weight; Mn was 1,645, and dispersity: Mw / Mn was 1.30.

Synthesis Example 3 [Preparation Example of Amino Resin (A) Having Phenolic Hydroxyl Group] Benzoguanamine was placed in a four-necked flask equipped with a stirrer, a thermometer, a Dean Stark, and a nitrogen gas inlet tube.
7 g (0.1 mol), 48.8 g (0.4 mol) of p-hydroxybenzaldehyde and 88.8 g (1.2 mol) of n-butanol were charged, and the reaction temperature was raised to 125 ° C. while stirring. After reaching the same temperature,
The reaction solution became homogeneous in 20 minutes. 2 at the same temperature
The reaction was continued for 4 hours.

After the reaction, n-butanol was distilled off under a reduced pressure of 5.33 × 10 ⁴ pascals.
Washing with a mixed solution of hexane / ethyl acetate (2/1) removed excess p-hydroxybenzaldehyde. Add ethylene glycol monobutyl ether,
The non-volatile content was adjusted to 60%, and the acid value of the resin solid was 85.2.
An amino resin (A-3) having a phenolic hydroxyl group of mg KOH / g was obtained. The number average molecular weight in terms of polystyrene; Mn was 4000, and the degree of dispersion; Mw / Mn was 3.26.

Synthesis Example 4 [Preparation Example of Amino Resin Having Carboxyl Group (A)] Benzoguanamine was added to a four-necked flask equipped with a stirrer, a thermometer, a Dean Stark, and a nitrogen gas inlet tube.
1 g (0.3 mol), 44.4 g (0.3 mol) of glyoxylic acid (50 wt% aqueous solution) and 133.2 g (1.8 mol) of n-butanol were charged, and the temperature was raised to 115 ° C. while stirring. did. After reaching the same temperature, the reaction solution became homogeneous after 10 minutes, but became cloudy again after a while. One hour after reaching the reaction temperature, 73.0 g of formaldehyde (37% aqueous solution)
(0.9 mol), the reaction temperature was lowered to 100 ° C., and the reaction was continued for 2 hours. Then, the reaction was further continued for 3 hours while distilling off water under a reduced pressure of 3.33 × 10 ⁴ Pascal.

Thereafter, the pH was adjusted to 8.0 with dimethylethanolamine, and unreacted formaldehyde, n-butanol and water were distilled off under reduced pressure. Finally,
It was diluted with ethylene glycol monobutyl ether to adjust the non-volatile content to 60%, to obtain the desired butyl etherified amino resin solution. The amino resin (A)
Abbreviated as -4). The acid value of the amino resin solid is N,
Before neutralizing N-dimethylethanolamine, 27.6 mg
KOH / g, number average molecular weight in terms of polystyrene;
Mn was 2150 and the degree of dispersion; Mw / Mn was 1.42.

Synthesis Example 5 [Preparation Example of Amino Resin Having Carboxyl Group (A)] In a four-necked flask equipped with a stirrer, a thermometer, a Dean Stark, and a nitrogen gas introducing tube, 2- (4,6-diamino-A) was prepared.
1,3,5-triazin-2-yl) -benzoic acid to 4
6.2 g (0.2 mol), glyoxylic acid (50 wt.
% Aqueous solution) and 88.8 g (1.2 mol) of n-butanol, and the mixture was heated to a reaction temperature of 115 ° C with stirring. After reaching the same temperature, the reaction solution became homogeneous within 10 minutes. One hour after reaching the reaction temperature, the reaction was continued for another 4 hours while distilling off water under reduced pressure of 5.33 × 10 ⁴ Pascal.

Thereafter, the pH was adjusted to 8.0 with N, N-dimethylethanolamine. Next, ethylene glycol monobutyl ether was added thereto, and n-butanol was distilled off under reduced pressure. After cooling, ethylene glycol monobutyl ether was added to reduce the nonvolatile content to 60%, thereby obtaining a butyl etherified amino resin solution. Hereinafter, this is referred to as amino resin (A-5). The acid value of the amino resin solid is
174 m before neutralization with N, N-dimethylethanolamine
gKOH / g, the number average molecular weight in terms of polystyrene; Mn was 1250, and the degree of dispersion; Mw / Mn was 1.34.

Synthesis Example 6 [Reference Example of Preparation of Amino Resin Using 2- (4,6-Diamino-1,3,5-triazin-2-yl) -benzoic acid-formaldehyde] Agitator, thermometer, Dean-Stark and In a four-necked flask equipped with a nitrogen gas inlet tube, 2- (4,6-diamino-1,3,5-triazine-2 containing 12.3% of water was added.
-Yl) 131.7 g of benzoic acid, 202.8 g of a 37% aqueous formaldehyde solution and 222.3 g of n-butanol
Was immersed in an oil bath heated to 115 ° C. with stirring. After 15 minutes, a homogeneous solution was obtained and reflux was started. After continuing the reaction for 2 hours, N, N-dimethylethanolamine was added to adjust the pH to 8.0. Water and excess formaldehyde were distilled off under reduced pressure of 5.33 × 10 ⁴ pascal over 3 hours. Next, after distilling off water and n-butanol, the mixture was diluted with ethylene glycol monobutyl ether to a nonvolatile content of 60%.
A methyl etherified amino resin solution was obtained. Less than,
This is abbreviated as amino resin (R-1). The acid value of the amino resin solid before neutralization with N, N-dimethylethanolamine was 94.6 mgKOH / g, the number average molecular weight in terms of polystyrene; Mn was 2,150, and the degree of dispersion: Mw /
Mn was 5.12.

Synthesis Example 7 (Preparation Example of Butylated Melamine Resin for Comparison) In a four-necked flask equipped with a stirrer, a thermometer, a Dean Stark, and a nitrogen gas inlet tube, 126 g of melamine, a hemi-formal solution [trade name: Hormit NB, 375 g of formaldehyde / n-butanol / water = 4/5/1 (parts by weight) manufactured by Dainippon Ink and Chemicals, Inc.] and 257 g of n-butanol were added, and 0.5 g of formic acid was further added, followed by stirring. Then, the mixture was heated to a reflux state. further,
Water was distilled off over 4 hours while maintaining the reflux state.
Next, excess n-butanol was distilled off under reduced pressure. After the reaction, the mixture was diluted with ethylene glycol monobutyl ether to obtain a resin solution having a nonvolatile content of 60%. Hereinafter, this is abbreviated as butylated melamine resin (C-1).

Synthesis Example 8 [Preparation Example of Water-Soluble or Water-Dispersible Resin (B)] Ethylene glycol was used as a solvent in a four-necked flask equipped with a stirrer, thermometer, reflux condenser, nitrogen gas inlet tube and dropping funnel. 450 g of monoisopropyl ether was charged, and the temperature was raised to 120 ° C. While maintaining this temperature,
From the dropping funnel, 24.0 g of acrylic acid, 75.0 g of isobutoxymethylacrylamide, and 75.0 of styrene.
g, 66.0 g of ethyl acrylate, 60.0 g of n-butyl acrylate and 12.0 g of azobisisobutyronitrile.
g was continuously added dropwise over 4 hours.
One hour later, from the end of the dropwise addition, 3.0 g of di-tert-butyl peroxide was added, and the reaction was further continued for 2 hours. Then, after distilling off 380.0 g of the solvent under reduced pressure, N, N-dimethylethanolamine, 30.0 g
Neutralized. Diluted with water, 210.0 g, the nonvolatile content is 50%, the organic solvent content (including amine) is 15%,
And the acid value of the resin solution becomes 26.2 mgKOH / g;
An aqueous solution of an acrylic resin was obtained. Hereinafter, this is abbreviated as acrylic resin (B-1).

Synthesis Example 9 [Preparation Example of Water-Soluble or Water-Dispersible Resin (B)] n-Butanol 45 was placed in a four-necked flask equipped with a stirrer, thermometer, reflux condenser, nitrogen gas inlet tube and dropping funnel.
0 g was charged and the temperature was raised to 110 ° C. While maintaining this temperature, a mixture composed of 105 g of methacrylic acid, 105 g of styrene, 90 g of ethyl acrylate and 6 g of benzoyl peroxide was continuously dropped from the dropping funnel over 4 hours. One hour after the completion of dropping, 3 g of benzoyl peroxide
Was added, and the reaction was further continued for 2 hours. The obtained acrylic resin solution had a nonvolatile content of 39.8% and an acid value of the resin solution of 90.9 mgKOH / g.

Subsequently, a stirrer, a thermometer, a reflux condenser,
In a four-necked flask equipped with a nitrogen gas inlet tube and a dropping funnel, 150 g of the obtained acrylic resin solution and 140 g of "Epiclon 7050" (trade name of epoxy resin manufactured by Dainippon Ink and Chemicals, Inc.) were charged at 60 ° C. After the temperature was raised, 10 g of N, N-dimethylethanolamine was added,
The temperature was further raised to the reflux state, and this state was maintained for 2 hours. Then, 5 g of N, N-dimethylethanolamine,
A mixture consisting of water, 300 g and 15 g of ethylene glycol monobutyl ether was added dropwise over 20 minutes, and the mixture was subjected to phase inversion emulsification. Further, stirring was continued at 70 ° C. for 8 hours. Finally, n-butanol and excess water were distilled off under heating and reduced pressure, and the nonvolatile content was 38.2%, the organic solvent content (including amine) was 6%, and the acid value of the resin solution was 23.7 mg KOH. / G of an acrylic resin modified epoxy resin solution. Hereinafter, this is abbreviated as acrylic-modified epoxy resin (B-2).

Example 1 20.0 g of the amino resin (A-1) obtained in Synthesis Example 1, 36.9 g of the acrylic resin (B-1) obtained in Synthesis Example 8, 14.2 g of ethylene glycol monobutyl ether, and triethylamine 3 0.3 g and p-toluenesulfonic acid 0.0
By mixing 6 g, an aqueous resin composition having a nonvolatile content of 42.8% was prepared.

Example 2 20.0 g of the amino resin (A-3) obtained in Synthesis Example 3, 36.9 g of the acrylic resin (B-1) obtained in Synthesis Example 8, 14.2 g of ethylene glycol monobutyl ether, and triethylamine 3 0.3 g and p-toluenesulfonic acid 0.0
By mixing 6 g, an aqueous resin composition having a nonvolatile content of 42.8% was prepared.

Example 3 20.0 g of the amino resin (A-2) obtained in Synthesis Example 2, 17.5 g of ethylene glycol monobutyl ether and p-
Toluenesulfonic acid (0.06 g) was mixed to prepare an aqueous resin composition having a nonvolatile content of 42.8%.

Example 4 20.0 g of the amino resin (A-4) obtained in Synthesis Example 4, 17.5 g of ethylene glycol monobutyl ether and p-
Toluenesulfonic acid (0.06 g) was mixed to prepare an aqueous resin composition having a nonvolatile content of 42.8%.

Example 5 20.0 g of the amino resin (A-5) obtained in Synthesis Example 5, 17.5 g of ethylene glycol monobutyl ether and p-
Toluenesulfonic acid (0.06 g) was mixed to prepare an aqueous resin composition having a nonvolatile content of 42.8%.

Reference Example 1 20.0 g of the amino resin (R-1) obtained in Synthesis Example 6, 36.9 g of the acrylic resin (B-1) obtained in Synthesis Example 8, 17.5 g of ethylene glycol monobutyl ether and p −
Toluenesulfonic acid (0.06 g) was mixed to prepare an aqueous resin composition having a nonvolatile content of 42.8%.

Comparative Example 1 20.0 g of the amino resin (C-1) obtained in Synthesis Example 7, 36.9 g of the acrylic resin (B-1) obtained in Synthesis Example 8, 14.2 g of ethylene glycol monobutyl ether, and triethylamine 3 0.3 g and p-toluenesulfonic acid 0.0
By mixing 6 g, an aqueous resin composition having a nonvolatile content of 42.8% was prepared.

Example 6 20.0 g of the amino resin (A-1) obtained in Synthesis Example 1, 36.9 g of the acrylic resin (B-2) obtained in Synthesis Example 9, 3.1 g of ethylene glycol monobutyl ether, ion exchange 2. 11.1 g of water, N, N-dimethylethanolamine
2 g and 0.06 g of p-toluenesulfonic acid were mixed to prepare an aqueous resin composition having a nonvolatile content of 8.0%.

Example 7 20.0 g of the amino resin (A-2) obtained in Synthesis Example 2, 36.9 g of the acrylic resin (B-2) obtained in Synthesis Example 9, 3.1 g of ethylene glycol monobutyl ether, ion exchange 11.1 g of water and 0.06 of p-toluenesulfonic acid
g was mixed to prepare an aqueous resin composition having a nonvolatile content of 8.0%.

Comparative Example 2 20.0 g of the amino resin (C-1) obtained in Synthesis Example 7, 36.9 g of the acrylic resin (B-2) obtained in Synthesis Example 9, 3.1 g of ethylene glycol monobutyl ether, and ion 11.1 g of exchanged water, 3.2 g of N, N-dimethylethanolamine and 0.06 g of p-toluenesulfonic acid were mixed to prepare an aqueous resin composition having a nonvolatile content of 8.0%.

Examples 1 to 7, Comparative Examples 1 and 2, and Reference Example 1
For each aqueous resin composition obtained in the above, the properties of the aqueous resin composition and various coating film performance tests using these as a clear coating were performed in the manner described below, and the aqueous resin composition and a coating using the same were used. The coating was evaluated. The results are summarized in Tables 1 and 2. As is clear from Tables 1 and 2, the water-soluble resin composition and the water-based paint of the present invention were prepared using the 2- (4,6-diamino-1,3,5-triazine-2-) shown in Reference Example. It is evident that the water-soluble resin composition using an amino resin synthesized with yl) -benzoic acid-formaldehyde and a water-based coating exhibit excellent performance. In addition, it is clear that the water-soluble resin composition and the water-based paint constructed using the conventionally known butylated melamine resin show superior performance.

[0079]

[Table 1] [Table 1]

[0080]

[Table 2] [Table 2]

[Guidelines for Evaluation of Various Performances] The gist of each test is as follows. In addition, the evaluation was indicated by ；: good Δ: acceptable (practical range) ×: unacceptable.

1. Property test of aqueous resin composition 1-1. Miscibility When an amino resin and a water-soluble or water-dispersible resin were mixed to prepare an aqueous resin composition, it was visually determined whether or not they were uniformly mixed. At this time, if they were not mixed, it was impossible to provide them for the following tests.

1-2. Storage stability After storing each of the above aqueous resin compositions at a temperature of 40 ° C. for 30 days, the storage stability was evaluated by observing the appearance of the aqueous resin composition and measuring the change in viscosity.

2. Test of coating film performance 2-1. Preparation of Test Panel The above-mentioned aqueous resin composition was applied on a tin plate having a thickness of 0.23 mm using a bar coater such that the film thickness after drying was 6 to 8 μm. Minutes,
Heat drying was performed. Each of the obtained coated plates was subjected to various tests described below as test panels.

2-2. Water resistance Each test panel was separately immersed in boiling water for 30 minutes, and the state of the coating film was visually evaluated.

2-2. Solvent resistance acetone rubbing test (load 1kg x 200 reciprocations)
, The remaining condition of the coating film remaining without being dissolved was visually evaluated.

2-3. Pencil hardness Evaluation was performed in accordance with JIS K-5400, and the results are shown in Table.

[0088]

According to the present invention, a highly versatile amino resin, which is excellent in curability, water resistance, workability and hardness, and is made of a commercially available inexpensive material, is contained as an essential component. An aqueous resin composition and an aqueous paint can be provided.

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (Reference) C09D 161/26 C09D 161/26 201/08 201/08 (72) Inventor Yoshitomo Yonehara 1-Cenari, Sakura-shi, Chiba 1-1 (72) Inventor Katsuharu Takahashi 5-21-2 Someno, Sakura City, Chiba Pref. DA171 EA012 GA05 GA06 MA08 MA10

Claims (8)

[Claims] An aqueous resin composition comprising an amino resin (A) obtained by condensing (a) a triazine compound and (b) an aldehyde carboxylic acid and / or hydroxybenzaldehyde as an aldehyde compound. 2. The method of claim 1, wherein (a) the triazine compound is melamine, benzoguanamine, or (4,6-diamino-1,3,5).
The aqueous resin composition according to claim 1, wherein the composition is at least one selected from the group consisting of -triazin-2-yl) benzoic acid. 3. The aqueous resin composition according to claim 1, wherein (b) the aldehyde compound is at least one selected from the group consisting of glyoxylic acid, succin semialdehyde, and hydroxybenzaldehyde. . 4. An amino resin (A) comprising (a) melamine, benzoguanamine and (4,6-diamino-1,3,5).
Condensation of at least one triazine compound selected from the group consisting of -triazin-2-yl) benzoic acid and (b) at least one aldehyde compound selected from the group consisting of glyoxylic acid, succin semialdehyde, and hydroxybenzaldehyde The aqueous resin composition according to any one of claims 1 to 3, which is obtained by simultaneously performing an etherification reaction with a monohydric alcohol. 5. A carboxyl group of the amino resin (A) and / or
The aqueous resin composition according to any one of claims 1 to 4, wherein the phenolic hydroxyl group is partially or entirely neutralized with an aliphatic amine. 6. An aqueous resin composition comprising an amino resin (A) and a water-soluble or water-dispersible resin (B) containing a group reactive with the amino resin (A). Item 1
The aqueous resin composition according to any one of Items 1 to 5, wherein 7. The aqueous resin composition according to claim 6, wherein the water-soluble or water-dispersible resin (B) containing a group reactive with the amino resin (A) is a resin having a carboxyl group. 8. An aqueous paint containing the aqueous resin composition according to any one of claims 1 to 7.