JPH05287184A - Alkyd resin composition dispersed in water - Google Patents

Abstract

PURPOSE:To obtain the subject composition useful as a varnish or coating, low in viscosity and stable even in the range of high nonvolatile content by addition/condensation reaction between specific two kinds of alkyd resins and an epoxy group-contg. alkoxysilane compound followed by neutralizing the product and dispersing the neutralized product in water. CONSTITUTION:A reaction product is first obtained by addition/condensation reaction between (A) an alkyd resin modified with drying oil fatty acid or semi-drying oil fatty acid with an acid value of <=5, hydroxyl value of 1-50 and oil length of 30-80 (hydrophobic alkyd resin), (B) a second alkyd resin modified with drying oil fatty acid or semi-drying oil fatty acid with an acid value of 10-200, hydroxyl value of <=5 and oil length of 30-80 (hydrophilic alkyd resin) and (C) a coupling agent consisting of an alkoxysilane compound containing in the molecule epoxy group in the weight ratios A/B and (A+B)/C of (95:5) to (5:95) and (80:20) to (99.9:0.1), respectively. Thence, this reaction product is neutralized with ammonia or an amine and then dispersed in water, thus providing the objective composition.

Description

Detailed Description of the Invention

[0001] BACKGROUND The present invention relates to a useful water-dispersible alkyd resin composition as the resin component of the air drying of the aqueous alkyd resin paint.

Alkyd resins modified with drying oils or semi-drying oils or fatty acids thereof are oxidatively polymerized by oxygen in the air and hardened, so that they are widely used as vehicle resins for ordinary temperature-drying paints for general use. This paint is generally a solvent type, but there is a demand for conversion to an aqueous type from the viewpoint of environmental protection and resource saving. For this reason, a hydrophilic alkyd resin having a high acid value must be used after being neutralized with ammonia or amines, but if such a hydrophilic alkyd resin is used alone, the coating performance, especially the water resistance, is not satisfied.

Therefore, JP-A-57-200461 discloses that a condensation reaction product of a hydrophilic alkyd resin having a high acid value and a low hydroxyl value and a hydrophobic alkyd resin having a low acid value and a high hydroxyl value is neutralized before use. Is proposed. In addition, JP-A-60-470
No. 55 proposes the use of a condensation reaction product of a hydrophobic alkyd resin to which maleic anhydride is added to impart hydrophilicity to the hydrophobic alkyd resin and a hydrophobic alkyd resin to which maleic anhydride is not added.

[0004] These prior arts aim to improve the water resistance by connecting a hydrophobic alkyd resin to a hydrophilic alkyd resin by an ester bond. However, the hydrophilic alkyd resin and the hydrophobic alkyd resin are simply physical. Although it is superior in storage stability and the like to those that are mechanically blended and dispersed in water, the condensation reaction between the two types of alkyd resins that have already been polymerized is difficult, and the reaction product is dispersed in water. Therefore, an amphipathic organic solvent such as ethylene glycol monobutyl ether must be used in a relatively large amount. Furthermore, the aqueous dispersions and paints containing this reaction product have the drawback that the viscosity decreases with time in the high resin nonvolatile content region of 50% or more.

Therefore, an object of the present invention is that the hydrophilic alkyd resin component and the hydrophobic alkyd resin component of the dispersion resin are chemically bound to each other in a chemically stable form, and are easily dispersed in water. Also, it is to provide a water-dispersible alkyd resin composition and a coating having relatively low viscosity and excellent in storage stability and corrosion resistance.

DISCLOSURE OF THE INVENTION The present invention provides (A) an acid value of 5 or more modified with a dry oil fatty acid or a semi-dry oil fatty acid, a hydroxyl value of 1 to 50, and an oil length of 30 to.
80 alkyd resin, (B) dry oil fatty acid or semi-dry oil fatty acid modified acid value 10-200, hydroxyl value 5 or less, oil length 30-80 alkyd resin, and (C) an epoxy group in the molecule. Addition of alkoxysilane compounds containing /
A water-dispersible alkyd resin composition obtained by neutralizing a condensation reaction product and dispersing it in water.

Preferably, the weight ratio of component (A) / component (B) of the addition / condensation reaction product is 95/5 to 5/9.
5, more preferably 80/20 to 20/80,
The weight ratio of component (A) + component (B) / component (C) is 80 /
It is 20-99.9 / 0.1. The addition / condensation reaction product preferably has an acid value of 5 or more.

Detailed Discussion Component (A) (hydrophobic alkyd resin) This component may be essentially the same as the resin component of the solvent-type room temperature drying alkyd resin coating composition. That is, it can be produced by polycondensing a polybasic acid component, a polyhydric alcohol component, and a fatty acid component according to a conventional method.

Examples of polybasic acid components include phthalic acid, isophthalic acid, terephthalic acid, trimellitic acid, tetrahydrophthalic acid, succinic acid, maleic acid, fumaric acid, adipic acid, itaconic acid, azelaic acid, pyromellitic acid and the like. The acid anhydrides and the like are generally used.

As the polyhydric alcohol component, ethylene glycol, propylene glycol, butanediol, decanediol, diethylene glycol, pentanediol, neopentyl glycol, glycerin, trimethylolethane, trimethylolpropane, pentaerythritol and the like are generally used.

Examples of the fatty acid component include linseed oil, safflower oil, soybean oil, sesame oil, poppy oil, eno oil, corn oil, tall oil, sunflower oil, cottonseed oil, tung oil, dehydrated castor oil, and other drying oils and semi-drying oils. Synthetic unsaturated fatty acids represented by oil fatty acids and hydiene fatty acids are common.

In addition to the above components, a small proportion of a monobasic acid such as benzoic acid and a hydroxycarboxylic acid such as p-hydroxybenzoic acid may be contained.

The component (A) can be produced by dehydration condensation of these components in an inert gas atmosphere at about 200 to 240 ° C. until the acid value becomes 5 or less. The hydroxyl value must be in the range of 1 to 50 and the oil length must be in the range of 30 to 80.

Component (B) (Hydrophilic Alkyd Resin) The component (B) is obtained by imparting hydrophilicity by introducing a pendant carboxyl group into the component (B) described above. There are generally two methods of introducing a pendant carboxyl group, one of which is a method of reacting a terminal hydroxyl group of a hydrophobic alkyd resin with a polybasic acid anhydride such as phthalic anhydride, tetrahydrophthalic anhydride, or trimellitic anhydride. is there. This method can be performed by reacting both at a temperature of 180 ° C. or higher. Preference is given to using the anhydride of trimellitic acid, which is a tribasic acid.

Another method is a method in which maleic anhydride is added to the double bond of the unsaturated fatty acid used and then the acid anhydride ring is hydrolyzed with approximately equivalent amount of water to open the ring. In the addition reaction, the hydrophobic alkyd resin and maleic anhydride are mixed in the range of 120-200.
It can be carried out by heating at ℃ for 1 to 3 hours. The ring-opening reaction with water can be carried out before the coupling reaction with the component (A), but is preferably carried out after the coupling reaction with the component (A) in order to preserve the introduced pendant carboxy group as much as possible.

The component (B) must have an actual or theoretical acid value of 10 to 200, a hydroxyl value of 5 or less, and the oil length must be in the same range as the component (A).

Component (C) (Coupling Agent) The present invention is characterized by using a silane coupling agent for coupling the components (A) and (B). This coupling method consists of (A) component and (B)
It is easier to synthesize than the partial condensate obtained by ester bond of the component, and the linkage is chemically stable. Besides (A)
Since the component (C) is interposed between the component and the component (B), the resin form is more stable than the reaction product of the prior art in which both components are directly linked by an ester bond, so that it is easier to form particles and the dispersion The stability over time is improved.

The component (C) has an alkoxysilyl group that can be bonded to the hydroxyl group of the hydrophobic alkyd resin by a dealcohol reaction to the terminal hydroxyl group of the hydrophobic alkyd resin of the component (A) or after being hydrolyzed to a silanol group. There must be. Furthermore, the component (C) must have an epoxy group (oxirane ring) to which the carboxyl group of the component (B) is bonded by an addition reaction in the molecule.

Such an alkoxysilane compound having an epoxy group in the molecule is known as a kind of silane coupling agent and is commercially available. Examples thereof include γ-glycidoxypropyltrimethoxysilane (KBM403 manufactured by Shin-Etsu Chemical and SH6040 manufactured by Toray Dow Corning Silicone), γ-glycidoxypropylmethyldiethoxysilane (KBE402 manufactured by Shin-Etsu Chemical),
β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane (KBM303 manufactured by Shin-Etsu Chemical Co., Ltd.) and the like.

Coupling of components (A) and (B) First, the component (C) is reacted with the component (A). This reaction can be carried out by heating both at about 120 ° C. for 3 hours. Next, the component (B) was added to this reaction product to obtain about 150
The coupling is completed by heating at 0 ° C for 2 hours. After that, when the component (B) is a maleic anhydride adduct, the acid anhydride ring is opened by hydrolysis.

Weight ratio of component (A) and component (B) (A) /
(B) is 95/5 to 5/95, preferably 80/20 to
It can be in the range of 20/80. The component (C) has a weight ratio of (A) + (B) / (C) of 80/20 to 99.
The range of 9 / 0.1 is preferable. If this ratio is too large, the dispersibility of the product and the membrane performance will be adversely affected, and if it is too small, the coupling will be incomplete and the stability of the dispersion and the coating will be poor.

The acid value of the entire coupling product must be 5 or more. Otherwise, it will be difficult to disperse in water after neutralizing with ammonia or amine.

Dispersion of Coupling Product in Water The coupling product of the component (A) and the component (C) of the component (B) thus obtained can be neutralized and then dispersed in water. .. Therefore, if necessary, an amphipathic solvent soluble in water is added to the coupling product, neutralized with ammonia or amine, and then water is added to disperse the product.

Amphiphilic solvents added as required include alcohols such as ethanol, n-propyl alcohol, isopropyl alcohol, butanol, and glycol monoethers such as ethylene glycol monomethyl-, ethyl-, propyl-, butyl ether. , A glycol ether such as diethyl glycol, a mixture thereof and the like. The amount is 100 parts by weight or less, preferably 20 parts by weight or less, per 100 parts by weight of the coupling resin.

As the neutralizing agent, in addition to ammonia, amines such as trimethylamine, triethylamine, tripropylamine, dimethylamine, diethylamine, 2
-Dimethylaminoethanol, 2-diethylaminoethanol and the like can be used.

The neutralized coupling resin is generally dispersed in a nonvolatile matter of 50% or more by adding water. This water-based alkyd resin varnish can be used for producing a room-temperature-drying water-based alkyd resin coating by adding a conventional additive such as a pigment, a surfactant, an antifoaming agent and a drier. The paint thus obtained has a lower viscosity than the conventional product even at a non-volatile content of 60%, has a low solvent content, is excellent in storage stability, and has a coating film performance (salt spray test) better than that of the conventional product. It is excellent.

The present invention will be described in detail below with reference to examples. In the examples, "parts" and "%" are based on weight.

Example 1 Preparation of Hydrophobic Alkyd Resin A Soybean oil fatty acid 674 parts Pentaerythritol 190 parts Phthalic anhydride 174 parts Tetrahydrophthalic anhydride 19 parts Trimellitic anhydride 9 parts Dibutyltin oxide 2 parts Xylene 20 parts

The above raw materials were placed in a flask equipped with a reflux condenser and stirred at 240 ° C. in a nitrogen gas atmosphere for about 8 hours.
The mixture was heated for an hour and reacted until the resin acid value became 5. The theoretical OH number of this alkyd resin is 18.5.

Production of hydrophilic alkyd resin B-1 Flaxseed oil fatty acid 675 parts Trimethylolpropane 160 parts Neopentyl glycol 60.7 parts Isophthalic acid 189 parts Dibutyltin oxide 2 parts Xylene 20 parts

The above raw materials were placed in a flask equipped with a reflux condenser and stirred at 240 ° C. in a nitrogen gas atmosphere at about 8 ° C.
The mixture was heated for an hour and reacted until the resin acid value became 5. The theoretical OH number of this alkyd resin is zero. Continue to 2
The temperature was lowered to 00 ° C., 55 parts of maleic anhydride was added, and the mixture was reacted at the same temperature for 3 hours. The theoretical acid value of this maleated alkyd resin is 60.

In a separate reaction vessel, add 5 parts of hydrophobic alkyd resin A.
Then, 37.3 parts of KBM403 (γ-glycidoxypropyltrimethoxysilane manufactured by Shin-Etsu Chemical Co., Ltd.) was added to this, and the mixture was reacted at 120 ° C. for 3 hours while stirring in a nitrogen gas atmosphere.

Subsequently, the hydrophilic alkyd resin B-150
0 part was added and reacted at 150 ° C. for 2 hours. 4 parts of water was added to the obtained reaction product, and the mixture was heated at 80 ° C. for 2 hours to carry out the ring-opening reaction of the maleic anhydride ring. The resin acid value at this time was 15.4.

Next, 150 parts of butyl cellosolve was added, neutralized with 1.0 equivalent of triethylamine, and water was added to emulsify to obtain an aqueous varnish having a nonvolatile content of 50%.

Example 2 The same as Example 1 except that the amount of KBM403 used in Example 1 was changed from 37.3 parts to 18.7 parts.

Example 3 250 parts of the hydrophobic alkyd resin A of Example 1 and KBM
18.7 parts of 403 were reacted in a nitrogen gas atmosphere with stirring at 120 ° C. for 3 hours.

Subsequently, the hydrophilic alkyd resin B of Example 1
-1 750 parts was added and reacted at 150 ° C. for 2 hours.
Water (7.5 parts) was added to the obtained reaction product, and the mixture was heated at 80 ° C. for 2 hours to carry out the ring-opening reaction of the maleic anhydride ring. The resin acid value at this time was 35.5.

Next, 150 parts of butyl cellosolve was added, neutralized with 1.0 equivalent of triethylamine, and water was added to emulsify to obtain an aqueous varnish having a nonvolatile content of 50%.

Example 4 Preparation of Hydrophilic Alkyd Resin B-2 Hydrophilic alkyd resin except that the amount of maleic anhydride was increased from 55 parts to 117 parts in the preparation of hydrophilic alkyd resin B-1 of Example 1. Same as B-1. Theoretical acid value of resin = 120

750 parts of hydrophobic alkyd resin A and KB
57.3 parts of M403 was reacted in a nitrogen gas atmosphere with stirring at 120 ° C. for 3 hours.

Subsequently, the hydrophilic alkyd resin B-2 25
0 part was added, and the mixture was reacted at 150 ° C. for 1 hour. 5 parts of water was added to the obtained reaction product, and the mixture was heated at 80 ° C. for 2 hours to carry out the ring-opening reaction of maleic anhydride. The resin acid value was 13.1. Next, 150 parts of butyl cellosolve was added, neutralized with 1.0 equivalent of triethylamine, and water was added to emulsify to obtain an aqueous varnish having a nonvolatile content of 50%.

Example 5 Preparation of hydrophilic resin B-3 Soybean oil fatty acid 394 parts Trimethylolpropane 17.8 parts Neopentyl glycol 298 parts Isophthalic acid 148 parts Dibutyltin oxide 2 parts Xylene 20 parts

The above raw materials were placed in a flask equipped with a reflux condenser and stirred at 240 ° C. in a nitrogen gas atmosphere for 8 hours.
It was heated for an hour and reacted until the acid value became 5 or less. Then, the temperature was lowered to 190 ° C and trimellitic anhydride 227 was added.
Parts were added and reacted at the same temperature for about 4 hours. The resin acid value at this time was 50.

Hydrophobic alkyd resin A 500 parts, KBM
37.3 parts of 403 were reacted in a nitrogen gas atmosphere with stirring at 120 ° C. for 3 hours.

Subsequently, the hydrophilic alkyd resin B-350
0 part was added and reacted at 150 ° C. for 2 hours. The resin acid value was 12.8. Next, after adding 150 parts of butyl cellosolve and neutralizing with 1.0 equivalent of triethylamine, water was added to emulsify and disperse to obtain an aqueous varnish having a nonvolatile content of 50%.

Comparative Example 1 500 parts of hydrophobic alkyd resin A and 500 parts of hydrophilic alkyd resin B-1 were stirred in a nitrogen gas atmosphere while 2
Direct reaction was carried out at 00 ° C. for 2 hours. 5 parts of water was added to the obtained reaction product, and the mixture was heated at 80 ° C. for 2 hours to carry out the ring-opening reaction of maleic anhydride. The resin acid value at this time was 22.3.

Next, 150 parts of butyl cellosolve was added, neutralized with 1.0 equivalent of triethylamine, and water was added to emulsify to obtain an aqueous varnish having a nonvolatile content of 50%.

Comparative Example 2 163 parts of butyl cellosolve was added to the hydrophilic alkyd resin B-3 of Example 4, neutralized with 1.0 equivalent of triethylamine, and water was added to emulsify the hydrophilic alkyd resin having a nonvolatile content of 66%. An aqueous varnish of B-3 was obtained.

600 parts of this aqueous varnish and 400 parts of the hydrophobic alkyd resin were mixed and then emulsified and dispersed in water to obtain an aqueous varnish having a nonvolatile content of 50%.

Evaluation The aqueous varnishes of Examples and Comparative Examples were made into paints, and the stability (change in viscosity with time) and the corrosion resistance of the coating film (salt spray test) were evaluated.

Titanium dioxide pigment (CR-50) 25 parts Nonionic emulsifier (Newcol 564) 1.5 parts Defoamer (Nopco 8034L) 0.2 parts Aqueous varnish (50% non-volatile content) 20 parts Water 7.0 parts

A pigment paste was prepared by uniformly dispersing the above components, and 53.7 parts of this pigment paste, 23.0 parts of the same aqueous varnish, 0.2 part of a defoaming agent, and a dryer (DICN) were used.
0.75 parts of ATE3111) and 2.35 parts of water were uniformly mixed with a disper to obtain a coating material having a nonvolatile content of 60%.

The initial viscosity of each paint and the viscosity after storage for 1 month at 40 ° C. were measured using an EM type viscometer (1.34 ° cone 5r
pm).

Further, each paint is applied to an iron plate (SPCC-SB) with N
o. Coating was performed using a 75 bar coater and dried at room temperature for 7 days to prepare a coated plate. The coated plate was sprayed with 5% saline at 35 ° C., and the time (SST resistance) until abnormalities such as swelling and peeling of the coating film occurred was measured. The results are shown in Table 1.

[0055]

[Table 1]

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location C09D 167/08 PLJ 8933-4J

Claims (2)

[Claims] 1. (A) An acid value of 5 or less modified with a dry oil fatty acid or a semi-dry oil fatty acid, a hydroxyl value of 1 to 50, and an oil length of 30.
To 80 alkyd resin, (B) alkyd resin having an acid value of 10 to 200 modified with a drying oil fatty acid or a semi-drying oil fatty acid, a hydroxyl value of 5 or less, and an oil length of 30 to 80, and (C) an epoxy group in the molecule. A water-dispersible alkyd resin composition obtained by neutralizing an addition / condensation reaction product of an alkoxysilane compound containing the above and dispersing it in water. 2. A component (A) of the addition / condensation reaction product /
The weight ratio of the component (B) is 95/5 to 5/95,
The weight ratio of component (A) + component (B) / component (C) is 80 /
The water-dispersible alkyd resin composition according to claim 1, which has an acid value of 5 or more and a value of 20 to 99.9 / 0.1.