JPH1149932A - Water-soluble resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a resin composition which has high water solubility and can give a cured film excellent in water resistance, adhesion and flexibility by including an etherified benzoguanamine formaldehyde resin having methylol groups etherified with an alcohol having a bisphenol skeleton and a resin reactive therewith. SOLUTION: The etherified benzoguanamine formaldehyde resin (A) having methylol groups etherified with an alcohol having a bisphenol skeleton is obtained by addition-condensing benzoguanamine with formaldehyde and reacting the obtained product with a 1-4C alcohol and a bisphenol-skeleton-containing alcohol. It is desirable that 0.1-0.4 on the average methylol group of the bisphenol-skeleton-containing alcohol is present per benzoguanamine nucleus. The resin (B) reactive with component A is exemplified by an alkyd resin or an acrylic resin. It is desirable that the ratio A/B is 10/90 to 70/30. This is used after dilution with a mixed solvent comprising a water-soluble solvent and water.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water-soluble resin composition suitable for a paint, an adhesive, a treatment agent for impregnating paper, and the like.

[0002]

2. Description of the Related Art In recent years, it has been desired to reduce the amount of organic solvent discharged when coating films for automobiles, industrial machines, steel furniture, and the like, and the conventional solvent-based paints are shifting to aqueous. .

In a water-based paint containing an amino resin as a curing agent, a water-based paint using a conventional alkyl etherified melamine resin or the like as an amino resin has good solubility in water or a water-miscible solvent, but water resistance in a cured coating film. There is a problem of inferiority.

On the other hand, conventional water-based paints using an alkyl etherified benzoguanamine resin have poor solubility in water or a water-miscible solvent and have a problem in paint stability.

[0005] In order to solve the above problems, there has been proposed an aqueous paint using an amino resin obtained by co-condensing melamine and benzoguanamine and alkylating them. However, there is much fuming, and sufficient performance has not yet been obtained in water-resistant paints.

[0006]

The invention according to claim 1 has high water solubility and low fuming properties, and its cured coating film has excellent water resistance, adhesion, and flexibility. The present invention provides a resin composition.

[0007]

The present invention provides (A) an etherified benzoguanamine formaldehyde resin having a methylol group etherified with an alcohol having a bisphenol skeleton and (B) a resin capable of reacting with the resin of the component (A). The present invention relates to a water-soluble resin composition contained therein.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The etherified benzoguanamine resin as the component (A) in the present invention is obtained by adding benzoguanamine and formaldehyde and subjecting it to a condensation reaction, and further reacting an alcohol having 1 to 4 carbon atoms with an alcohol having a bisphenol skeleton. It is a resin obtained by: This resin preferably has an average of 0.1 to 0.4 methylol groups etherified with an alcohol having a bisphenol skeleton per benzoguanamine nucleus, and preferably less than 0.1 or more than 0.4 Tends to have poor water resistance of the cured coating film. The etherified benzoguanamine formaldehyde resin of the component (A) has a bond formaldehyde content of 1.5 to 3.2 and a carbon number of 1 per benzoguanamine nucleus in terms of curability, water resistance, adhesion, and flexibility.
It is preferable that the compound has 1.1 to 2.8 alkoxy groups and 0.1 to 0.5 methylol groups.

The above addition, condensation and reaction with an alcohol are carried out, for example, as follows. That is,
A mixture of benzoguanamine, alcohol and formaldehyde is added under alkaline conditions (preferably at pH 9 to 11).
Heated to 0 to 65 ° C. to cause a methylolation reaction,
The mixture is heated to 50 to 65 ° C. under acidity (preferably pH 3 to 4) to cause addition and condensation reactions, and then to alkaline (preferably pH 3 to 4).
The target resin is obtained by a method of removing the solvent under reduced pressure under pH 9 to 11). Here, for 1 mole of benzoguanamine,
Formaldehyde 1.5-5.0 mol, carbon number 1-4
8 to 50 mol of alcohol, preferably 8 to 40 mol,
Alcohol having bisphenol skeleton 0.1 to 1.0
Mole, preferably 0.1 to 0.4 mole.

The alcohol having a bisphenol skeleton used in the component (A) of the present invention is represented by the following general formula (I) in which an alkylene oxide such as ethylene oxide or propylene oxide is added to a bisphenol compound such as bisphenol A or bisphenol F. Polyether diol.

Embedded image (Here, R ¹ and R ² each independently represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and R ³ and R ⁴ each independently represent an alkylene group having 1 to 6 carbon atoms. , M and n
Is each independently an integer of 1 to 50)

Such compounds are, for example, bisol 2EN-6 (R ¹ and R ² in the general formula (I) are methyl groups, and R ³ and R ⁴ are as bisol EOA series from Toho Chemical Industry Co., Ltd.). An ethylene group, m and n are compounds of 1.3), bisol 4EN (R ¹ and R ^{2 in the} general formula (I))
Is a methyl group, R ³ and R ⁴ are ethylene groups, m and n are compounds of 2, and bisol 6EN (R ^{1 in the} general formula (I))
And R ² are methyl groups, R ³ and R ⁴ are ethylene groups, m
And n are compounds of 3), bisol 10EN (in the general formula (I), R ¹ and R ² are methyl groups, R ³ and R ⁴ are ethylene groups, and m and n are compounds of 5), bisol 18EN
(In the general formula (I), R ¹ and R ² are methyl groups, and R ³ and R ⁴
Is an ethylene group, m and n are compounds of 9), bisol 30EN (in the general formula (I), R ¹ and R ² are methyl groups,
³ and R ⁴ are ethylene groups, m and n are commercially available under trade names such as 15 compounds), and bisol 2P (R ¹ and R ^{2 in the} general formula (I)) as a bisol POA series.
Is a methyl group, R ³ and R ⁴ are isopropylene groups, m and n are compounds of 1), bisol 2PN (general formula (I)
Wherein R ¹ and R ² are methyl groups, R ³ and R ⁴ are isopropylene groups, and m and n are compounds of 1), bisol 3PN
(In the general formula (I), R ¹ and R ² are methyl groups, and R ³ and R ⁴
Is an isopropylene group, m and n are compounds of 1.5),
Bisol 4PN (In the general formula (I), R ¹ and R ² are methyl groups, R ³ and R ⁴ are isopropylene groups, and m and n are 2
And bisol 6PN (compound of general formula (I) wherein R ¹ and R ² are methyl groups, R ³ and R ⁴ are isopropylene groups, and m and n are 3), and bisol 10PN (general formula (I ), R ¹ and R ² are methyl groups, R ³ and R ⁴ are isopropylene groups, m and n are compounds of 5, and bisol 20PN (in the general formula (I), R ¹ and R ² are methyl groups). ,
R ³ and R ⁴ are isopropylene groups, m and n are compounds of 10), bisol 30PN (in the general formula (I), R ¹ and R ² are methyl groups, R ³ and R ⁴ are isopropylene groups,
(m and n are 15 compounds).

The resin capable of reacting with the component (A) of the component (B) in the present invention is not particularly limited as long as it is cured by reacting with the component (A), and examples thereof include alkyd resins and acrylic resins. No.

The alkyd resin is, for example, a resin obtained by reacting a polycarboxylic acid, a polyhydric alcohol and, if necessary, an oil or these fatty acids. here,
Examples of polycarboxylic acids include phthalic acid, isophthalic acid, terephthalic acid, tetraphthalic acid, tetrahydrophthalic acid,
Maleic acid, fumaric acid, succinic acid, adipic acid, sebacic acid, trimellitic acid, pyromellitic acid and the like can be mentioned. These may be ester-forming derivatives such as the acid anhydride methyl ester. Examples of polyhydric alcohols include ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, neopentyl glycol, 1,4-butanediol, 1,6-hexanediol, trimethylene glycol, glycerin, trimethylolpropane, Trimethylolethane, pentaerythritol and the like can be mentioned. Examples of the oil include linseed oil, soybean oil, dehydrated castor oil, safflower oil, castor oil, coconut oil, tall oil and the like.

The alkyd resin can be produced by a known method. For example, when an oil is used, the oil is reacted with a polyhydric alcohol at 200 to 260 ° C. in the presence of a transesterification catalyst such as lithium hydroxide. After that, a polybasic acid and the remaining polyhydric alcohol are added and reacted at 180 to 250 ° C. When no oil is used, the raw materials are mixed and mixed.
There is a method of reacting at ~ 250 ° C.

Examples of the acrylic resin include β-monoethylenically unsaturated carboxylic acids such as acrylic acid, methacrylic acid, maleic acid, and itaconic acid;
Α, β-ethylenically unsaturated monomers having a hydroxyl group such as -hydroxyethyl, 2-hydroxypropyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, methyl acrylate,
Alkyl esters of α, β-monoethylenically unsaturated carboxylic acids such as ethyl acrylate, n-butyl acrylate, 2-ethylhexyl acrylate, methyl methacrylate, n-butyl methacrylate, acrylamide, methacrylamide, N- Acrylamide derivatives such as methylol acrylamide, N-methylol methacrylamide, and diacetone acrylamide; α, β-monoethylenically unsaturated carboxylic acid glycidyl esters such as glycidyl acrylate and glycidyl methacrylate; and aromatic fatty acids such as propionic acid and vinyl. Resins obtained by copolymerizing a saturated monomer or the like are included.

The above copolymerization is carried out in the presence of a radical catalyst such as azobisisobutylnitrile, benzoyl peroxide, dibutyl peroxide and cumene hydroperoxide in the range of 130 to 16
It can be carried out by heating to 0 ° C.

The alkyd resin and the acrylic resin are preferably adjusted to have an acid value of 30 to 100 and a hydroxyl value of 15 to 180. The resin thus adjusted is neutralized before use. be able to. If the acid value is too small, the water solubility or water dispersibility after neutralization is poor, and if the acid value is too large, the properties of the coating film tend to deteriorate. On the other hand, if the hydroxyl value is too small, the curability is poor, and if the hydroxyl value is too large, the water resistance of the coating film is poor.

The neutralization can impart water solubility or water dispersibility to the alkyd resin and the acrylic resin. The neutralization may be performed by neutralizing the acid groups of the resin with a base such as ammonia or amine. Examples of the amine include monopropylamine, monobutylamine, monoethanolamine, dimethylamine, diethylamine, triethylamine, triethanolamine, dimethylethanolamine, monophorin, and piperidi. Ammonia and amine are preferably used in an amount of 0.3 to 1.2 mol per equivalent of acid group.

In the water-soluble resin composition of the present invention,
(A) of the usage ratio (weight ratio) of the component (A) and the component (B)
/ (B) is preferably from 10/90 to 70/30. If it is less than 10/90, the curability tends to be inferior, and if it exceeds 70/30, the flexibility tends to be inferior.

The water-soluble resin composition of the present invention comprises isopropyl cellosolve, ethyl cellosolve, butyl cellosolve,
Diluted with a mixed solvent of water and a water-soluble solvent such as diacetone alcohol, 3-methoxy-3-methylbutan-1-ol and 3-methoxy-1-butanol so that the solid content becomes 10 to 90% by weight. it can.

The water-soluble resin composition of the present invention may contain an acid catalyst such as phosphoric acid or p-toluenesulfonic acid dodecylbenzenesulfonic acid for the purpose of improving curability. The amount of the acid catalyst used is preferably 1% by weight or less based on the component (A) from the viewpoint of stability. A pigment such as titanium white and other additives can be further added to the aqueous resin composition of the present invention according to the purpose. Also,
As a coating method, spray coating, coating with a roll coater, dip coating, spin coating, or the like can be employed.

[0022]

The present invention will be described below with reference to examples.

Production Example 1 80 flasks equipped with a stirrer, reflux condenser and thermometer
112.5 g (3 mol) of paraformaldehyde by weight,
960.0 g (30 mol) of methanol and 2.0 g of a 50% by weight aqueous sodium hydroxide solution were added to dissolve paraformaldehyde, and then 187.0 g of benzoguanamine.
(1 mol) and reacted at 60 ° C. for 3 hours. Thereafter, 4.0 g of 62% by weight nitric acid was added, and then bisol 4
EN (manufactured by Toho Chemical Industry Co., Ltd .; R ¹ and R ² in the general formula (I))
Is a methyl group, R ³ and R ⁴ are ethylene groups, and m and n are compounds of 2).
For 2 hours. Thereafter, 2.0 g of a 50% by weight aqueous sodium hydroxide solution was added, and then triethylamine 45% was added.
g, make the reaction solution alkaline, and add
rr). The end point was when the temperature in the flask reached 110 ° C. At the same time as the end point, 125 g of isopropyl cellosolve was added to adjust the solid content to 70% by weight. The amount of the formed etherified benzoguanamine resin is 4
30 g, and the viscosity was Z ₃ in Gardner viscosity.

Production Example 2 80 was added to a flask equipped with a stirrer, reflux condenser and thermometer.
131.5 g (3.5 mol) of paraformaldehyde, 960.0 g (30 mol) of methanol and 2.0 g of a 50% aqueous sodium hydroxide solution were added to dissolve paraformaldehyde, and then benzoguanamine 18 was added.
7.0 g (1 mol) was added, and the mixture was reacted at 60 ° C. for 3 hours. Then, after adding 4.0 g of 62% by weight nitric acid, bisol 10EN (manufactured by Toho Chemical Industry Co., Ltd .; general formula (I))
, R ¹ and R ² are methyl groups, R ³ and R ⁴ are ethylene groups, and m and n are compounds of 5) (100 g, 0.15 mol), and reacted at 60 ° C. for 2 hours. After this, 50
A 2.0% by weight aqueous sodium hydroxide solution was added, and then 45 g of triethylamine was added to make the reaction solution alkaline, and the mixture was concentrated under reduced pressure (50 torr). The end point was when the temperature in the flask reached 110 ° C. At the same time as the end point, 125 g of isopropyl cellosolve was added and the solid content was 70% by weight.
It was adjusted to become. The amount of the formed etherified benzoguanamine resin was 500 g, and the viscosity was Z _{2 to} Z ₃ in Gardner viscosity.

Production Example 3 In a flask equipped with a stirrer, reflux condenser and thermometer, 80
187.5 g (5 mol) of paraformaldehyde by weight,
960.0 g (30 mol) of methanol and 3.0 g of a 50% by weight aqueous sodium hydroxide solution were added to dissolve paraformaldehyde, and then 187.0 g of benzoguanamine.
(1 mol) and reacted at 60 ° C. for 5 hours. Then, after adding 10.0 g of 62% by weight nitric acid, bisol 2PN (manufactured by Toho Chemical Industry Co., Ltd .; in the general formula (I), R ¹ and R ² are methyl groups, and R ³ and R ⁴ are isopropylene groups). Wherein m and n are the compounds of 1) 30 g (0.09 mol)
It was charged and reacted at 60 ° C. for 2 hours. Thereafter, 8.0 g of a 50% by weight aqueous sodium hydroxide solution was added, and then 45 g of triethylamine was added to make the reaction solution alkaline.
Concentrate under reduced pressure (50 torr). The end point was when the temperature in the flask reached 110 ° C. At the same time as the end point, 140 g of isopropyl cellosolve was added and the solid content was 70% by weight.
It was adjusted to become. The amount of the resulting methyl etherified benzoguanamine resin was 400 g, and the viscosity was Z ₂ in Gardner viscosity.

Comparative Production Example 1 In a flask equipped with a stirrer, reflux condenser and thermometer,
131.5 g (3.5 mol) of paraformaldehyde, 960.0 g (30 mol) of methanol and 2.0 g of a 50% aqueous sodium hydroxide solution were added to dissolve paraformaldehyde, and then benzoguanamine 18 was added.
7.0 g (1 mol) was added, and the mixture was reacted at 60 ° C. for 3 hours. Then, after adding 4.0 g of 62% by weight nitric acid, 60
The reaction was carried out at 2 ° C. for 2 hours. After this, triethylamine 70
g, make the reaction solution alkaline, and add
rr). The end point was when the temperature in the flask reached 110 ° C. At the same time as the end point, 125 g of isopropyl cellosolve was added to adjust the solid content to 80% by weight. The amount of the produced methyl etherified benzoguanamine resin was 390 g, and the viscosity was Z ₄ in Gardner viscosity.

Comparative Production Example 2 In a flask equipped with a stirrer, reflux condenser and thermometer, 80
187.5 g (5 mol) of paraformaldehyde by weight,
960.0 g (30 mol) of methanol and 5.0 g of a 50% by weight aqueous sodium hydroxide solution were added to dissolve paraformaldehyde, and then 93.5 g of benzoguanamine.
(0.5 mol) and 63.0 g (0.5 mol) of melamine were added and reacted at 60 ° C. for 5 hours. Thereafter, 10.0 g of 62% by weight nitric acid was added, and the mixture was reacted under acidic conditions at 60 ° C. for 2 hours. After completion of the reaction, 8.0 g of a 50% by weight aqueous sodium hydroxide solution was added to make the reaction solution alkaline, and the mixture was concentrated under reduced pressure (50 torr). The end point was when the temperature in the flask reached 110 ° C. At the same time as the end point, 140 g of isopropyl cellosolve was added to adjust the solid content to 80% by weight. The amount of the resulting methyl etherified amino resin was 460 g, and the viscosity was Z ₂ in Gardner viscosity.

The average bond amount of formaldehyde, methoxy group, alcohol having a bisphenol skeleton and methylol group per one triazine nucleus of the resins obtained in Production Examples 1 to 3 and Comparative Production Examples 1 and 2 was ¹ H -NM
Table 1 shows the results of the R analysis and the calculation based on the material balance at the time of synthesis.

[0029]

[Table 1]

Production Example 4 A reaction vessel equipped with a stirrer was charged with 200 g of butyl cellosolve and kept at 120 ° C. under a nitrogen stream. A mixture of 60 g of styrene, 60 g of ethyl acrylate, 30 g of butyl acrylate, 60 g of methyl methacrylate, 60 g of 2-hydroxyethyl methacrylate, 30 g of acrylic acid and 6 g of azobisisobutyronitrile was dropped from the dropping tube over about 2 hours. Every hour, 1 g of azobisisobutyronitrile was added three times, and the mixture was further reacted for 2 hours to obtain an acrylic resin solution having a solid content of 60% by weight. To this acrylic resin solution were added 37 g of dimethylethanolamine and 500 g of ion-exchanged water, and water in the system was distilled off under reduced pressure to obtain an aqueous solution of an acrylic resin having a solid content of 60% by weight.

Examples 1 to 3 and Comparative Examples 1 and 2 The resins and titanium white obtained in Production Examples 1 to 3, Comparative Production Examples 1 and 2 and Production Example 4 were mixed and rolled according to the composition shown in Table 2 below. The mixture was kneaded and the coating was adjusted. Furthermore, thinner (composition;
(Butyl cellosolve / water = 10/90 (weight ratio)) was added to adjust the viscosity of the coating material to 30 seconds with a Ford cup # 4.

[0032]

[Table 2]

The paint was spray-coated on a coated plate (bonded steel plate treated with Bonderite # 144) so as to have a dry film thickness of 25 μm, and left at room temperature for 20 minutes.
Table 3 shows the evaluation results of the coated plates obtained by partial baking.

Each test method of the coating film performance is as follows. (1) Gloss: 60 ° reflection was measured according to JIS K5400. (2) Pencil hardness: determined by Mitsubishi Pencil Uni. (3) Cross cut: 100 squares were cut on the coating surface with a cutter knife at intervals of 1 mm, and the number of remaining squares when peeled off with a cellophane tape was evaluated. (4) Erichsen value: measured with an Erichsen tester. (5) Impact value: Determined in centimeters using a DuPont impact tester with a 1/2 inch-500 g impacting core.

(6) Boiling water resistance: steam (130 ° C., 1.
After treatment at 8 kg / cm ² ) for 30 minutes, the state of the coating film surface was visually judged. ：: no change Δ: slightly affected ×: affected (7) Paint stability: The paint was left at 40 ° C. for 20 days, and the change was visually observed. ：: No change ×: Separation into two layers (8) Fuming: After coating on a tin plate, baking was performed at 200 ° C. for 10 minutes in an oven, and the generated fuming was observed. ：: Almost no fuming ×: Very much fuming

[0036]

[Table 3]

[0037]

The water-soluble resin composition according to claim 1 has high water solubility and low fuming property, and the cured coating film has
It is excellent in water resistance, adhesion, flexibility and the like.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI C09J 201/02 C09J 201/02 // D21H 19/24 D21H 1/34 K

Claims (1)

[Claims] 1. An (A) etherified benzoguanamine formaldehyde resin having a methylol group etherified with an alcohol having a bisphenol skeleton and (B)
(A) A water-soluble resin composition containing a resin capable of reacting with the resin as the component.