JPH0464547B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a maleated alkyd resin emulsion composition, and more specifically, it has excellent water dispersibility and storage stability, and its coating film has little coloring and has excellent properties such as water resistance and corrosion resistance. The present invention relates to a maleated alkyd resin emulsion composition. In recent years, water-soluble alkyd resins have been widely used as vehicle components for general and industrial paints due to their low cost and non-polluting properties. Conventionally, water-soluble alkyd resins have generally been half-esterified using phthalic anhydride, trimellitic anhydride, etc. as a method of introducing the acid necessary to make the alkyd resin water-soluble. The water-soluble alkyd resin thus obtained is easily hydrolyzed by the anchimeric effect,
Storage stability is poor because the water-soluble alkyd resin becomes insolubilized. Furthermore, since the main chain of the water-soluble alkyd resin also has an ester bond, it is hydrolyzed in water and a neutralizing agent, and the main chain of the water-soluble alkyd resin is severed, resulting in poor storage stability. As an attempt to improve these drawbacks, there is a method of introducing acid through maleation. The maleated alkyd resin emulsion obtained by this method has acid groups constituting a hydrophilic part on the particle surface, and the particle interface is composed of a highly lipophilic oily component, so it is difficult to absorb water and neutralizing agents. It is stable against Furthermore, in order to facilitate water dispersion of the maleated alkyd resin, it has been common practice to use a large amount of an amphipathic organic solvent in the maleated alkyd resin. However, the aqueous dispersion obtained by this method is close to the level of an aqueous solution and has poor storage stability because it is hydrolyzed and the maleated alkyd resin becomes insolubilized due to increased contact with the medium or neutralizing agent. Furthermore, even if the aqueous dispersion is in the emulsion range, the amphiphilic organic solvent will swell the maleated alkyd resin emulsion particles during storage, and furthermore, water and a hydrating agent may be trapped inside the maleated alkyd resin emulsion particles. Poor storage stability due to straining. In addition, when maleating alkyd resins, alkyd resins modified with linseed oil fatty acids containing a large amount of unsaturated fatty acids (especially linoleic acid) that have three active double bonds in one molecule are easily maleated. The obtained linseed oil fatty acid-modified maleated alkyd resin has excellent water dispersibility, but the coating film obtained from this aqueous dispersion is colored, which limits its use. Ta. Therefore, the present inventors conducted extensive research with the aim of obtaining a maleated alkyd resin emulsion composition with excellent water dispersibility, little coloring of the coating film formed therefrom, and excellent water resistance. The invention was completed. That is, the present invention is modified with an oil or fat and/or fatty acid having an iodine value of 135 to 175 (hereinafter, this may be simply referred to as "drying (semi-) fatty acid"), and which has an iodine value of 135 to 175. A maleated alkyd resin with an acid value of 10 to 70 obtained by reacting maleic anhydride to an alkyd resin with an oil length of 35 to 80 containing 30% by weight or less of linoleic acid is neutralized and then dispersed in water. The present invention relates to an alkyd resin emulsion composition. The maleated alkyd resin used in the present invention is obtained mainly by reacting a dry (semi) oil fatty acid, a polybasic acid, a monobasic acid, and a polyhydric alcohol, and further by reacting maleic anhydride. Typical dry (semi) oil fatty acids used include, for example, linseed oil, safflower oil, soybean oil,
corn oil, cottonseed oil, grape kernel oil, hempseed oil,
Eno oil, poppy seed oil, sugarcane oil, rice bran oil and other fatty acids, tall oil fatty acids, etc.
These may be used alone or in combination of two or more so that the iodine value falls within the range of 135 to 175. The iodine value of the dry (semi-) fatty acid is 135~
175, preferably 140-170, more preferably 145
-165, and if the iodine value is lower than 135, it will be difficult to maleate and water dispersion will be difficult, and the coating film obtained from the aqueous dispersion will be insufficiently cured and the coating performance will be poor. inferior to the other 175
Those with an iodine value higher than 20% have the disadvantage that the resulting coating film is significantly colored. Furthermore, the amount of linoleic acid that can be contained as a component of the dry (semi-) fatty acid is 0 to 30% by weight,
Preferably about 1.5 to about 25% by weight in terms of water dispersibility
It is. The content of linoleic acid can be changed as required, but if the amount of linoleic acid exceeds 30% by weight, there is a drawback that the resulting coating film will be significantly colored. In addition, the content of the 9,11-linoleic acid component having a conjugated double bond in the drying (semi-) fatty acid must be 10% by weight or less, and if it exceeds 10% by weight, it will be subject to the maleation reaction. There is a risk of gelation during resin synthesis. The polybasic acid is a compound having 2 to 4 carboxyl groups in one molecule. in particular,
For example, phthalic acid, isophthalic acid, terephthalic acid, trimellitic acid, tetrahydrophthalic acid, succinic acid, maleic acid, adipic acid, sebacic acid,
azelaic acid, hymic acid, itaconic acid, methylcyclohexentricarboxylic acid, crotonic acid,
Pyromellitic acid and anhydrides thereof, etc. can be used. Among these, phthalic acid, isophthalic acid, and terephthalic acid are preferred. Examples of the monobasic acid include benzoic acid, paratertiary butylbenzoic acid, methylbenzoic acid, non-drying oil fatty acids, synthetic fatty acids, etc., which do not contain the above-mentioned fatty acids and are generally used in the production of alkyd resins. Among these, benzoic acid is preferred because it is low cost and has high coating film hardness. The polyhydric alcohol is an alcohol having 2 to 6 hydroxyl groups in one molecule, and specifically includes, for example, ethylene glycol, polyethylene glycol, propylene glycol, polypropylene glycol, butanediol, decanediol, diethylene glycol, and pentanediol. ,
Examples include neopentyl glycol, glycerin, trimethylolethane, trimethylolpropane, pentaerythritol, sorbitol, 1,4 cyclohexanedimethanol, tricyclodecane dimethanol, tris isocyanurate, and the like.
Furthermore, in addition to polyhydric alcohols, epoxy resins can also be used in the alkyd resin component. The alkyd resin components described above can be used alone or in combination of two or more. The alkyd resin can be produced by subjecting the above-mentioned components to a dehydration condensation reaction at about 150 to 250°C for about 3 to 10 hours in an inert gas atmosphere according to a known synthesis method. . Next, the synthesis of maleated alkyd resin is carried out using a mixture of the above-mentioned alkyd resin and maleic anhydride.
The reaction is carried out at 150 to about 230°C for about 1 to about 5 hours. The acid value of the maleated alkyd resin thus obtained is required to be in the range of 10 to 70, preferably in the range of 20 to 55. When the acid value is less than 10, water dispersion becomes difficult, and when it is more than 70, the water resistance of the coating film is impaired. The oil length of the maleated alkyd resin used in the present invention is in the range of 35 to 80, preferably in the range of 40 to 65. If the oil length is less than 35, the amount of maleic anhydride added will be small, making it impossible to obtain a stable maleated alkyd resin emulsion composition, and the number of active double bonds required for curing the coating will be small, resulting in insufficient curing. No coating film can be obtained. 80 on the contrary
Naturally, when the amount is larger, the amount of maleic anhydride necessary for water solubilization increases, so the acid value of the maleated alkyd resin increases, and the water resistance of the coating film obtained from it becomes poor. The viscosity of the maleic alkyd resin used in the present invention is not limited, but the Gardner foam viscometer value in a diluted solution of 60% by weight of butylcellulosolve is O~ _Z5.
preferably in the range of Q to _Z3 , more preferably in the range of T to _Z2 . When the Gardner foam viscometer value is smaller than O, water dispersion becomes easy, but the stability of the emulsion deteriorates and it is difficult to balance the two, and the water resistance of the coating film is also poor. Conversely, if the value is larger than _Z5 , water dispersion becomes difficult. Neutralizing agents used in the present invention include ammonia and organic amines for water dispersing the maleated alkyd resin, such as primary, secondary, or tertiary alkyl amines, and representative ones. Methylamine, ethylamine, propylamine, butylamine, amylamine, dimethylamine, diethylamine, dipropylamine, dibutylamine, trimethylamine, triethylamine, tripropylamine, morpholine; primary;
Secondary or tertiary alkanolamines, typical examples include monoethanolamine, diethanolamine, dimethylethanolamine, diethylethanolamine, and the like. Among these neutralizing agents, ammonia diethylamine has good dispersibility and is highly volatile and does not easily remain in the coating film.
Triethylamine and dimethylethanolamine are preferred. Further, the above neutralizing agents can be used alone or in combination of two or more. Generally, the amount of neutralizing agent used is based on the carboxyl group in the resin.
The amount is 0.1 to 2.0 equivalents, preferably 0.3 to 1.0 equivalents. Further, in the present invention, an alcohol-based organic solvent can be used as a water dispersion aid. The alcoholic organic solvent has the following formulas (1), (2) and (3) HO−R ₁ (1) HO−C _o H _2o −O R ₂ (2) HO−C _o H _2o −O C _o H _2o -O (3) In each of the above formulas, R ₁ represents an alkyl group having 2 to 6 carbon atoms, R ₂ represents an alkyl group having 1 to 4 carbon atoms, and n is an integer of 2 to 5. represents. These are alcohol-based solvents, cellosolve-based solvents, and carbitol-based solvents. Such an organic solvent is an organic solvent for dispersing the maleated alkyd resin in water, and has a polar group that has an affinity for the maleated alkyd resin and also has an affinity for water, and the balance between the two is maintained. An appropriate one is preferred. For example, the alcoholic organic solvents include ethyl alcohol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, isobutyl alcohol, sec-butyl alcohol, tert-butyl alcohol, isoamyl alcohol, sec-amyl alcohol, tert-amyl alcohol , propylene glycol monomethyl ether, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, propylene glycol monomethyl ether, propylene glycol ethyl ether, propylene glycol monopropyl ether, propylene glycol monobutyl ether, 3 -methoxy-3-methylbutanol, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether,
These include diethylene glycol monobutyl ether, dipropylene glycol monoethyl ether, dipropylene glycol monoethyl ether, and dipropylene glycol monobutyl ether.
Among the above alcohol-based organic solvents, alcohols having a _C2 to _C5 alkyl group are preferred. The alcoholic organic solvent is used in an amount of 25% by weight or less, preferably 10% by weight or less, more preferably 5% by weight or less, based on the solid content of the maleated alkyd resin. If the amount of the alcohol-based organic solvent is more than 25% by weight, as the temperature changes during storage of the maleated alkyd resin emulsion, the resin constituting the hydrophilic part on the particle surface will be redissolved, and the particle surface and particles will be further dissolved. The barrier of fatty acid groups constituting the interior is destroyed, and as a result, the hydrolysis of the emulsion is promoted, resulting in poor storage stability, and the coating film formed from the maleated alkyd resin emulsion has poor water resistance and corrosion resistance. It has a bad quality and is not satisfactory.
Furthermore, in the method of using the alcoholic organic solvent in the present invention, it is particularly preferable to use the alcoholic organic solvent in an amount of 25% based on the solid content of the maleated alkyd resin.
By using more than % by weight, water dispersion of the maleated alkyd resin becomes easier,
Furthermore, this is a method in which the alcohol-based organic solvent is removed to 25% by weight or less based on the solid content of the resin. The maleated alkyd resin emulsion composition thus obtained has a small particle size and good storage stability, and the coating film formed therefrom has good properties such as water resistance and corrosion resistance. In addition, the alcoholic organic solvent may be used alone or in combination.
Can be used in combination of more than one species. In addition, organic solvents and plasticizers other than those mentioned above may be used for purposes such as improving film-forming properties. To prepare the maleated alkyd resin emulsion composition of the present invention, the maleated alkyd resin is neutralized with a neutralizing agent, and if necessary, the alcoholic organic solvent is added at 25% by weight based on the solid content of the maleated alkyd resin. % or less, or if the amount of the alcohol-based organic solvent is more than 25% by weight based on the resin solid content, it is dissolved under reduced pressure after water dispersion to meet the scope of the present invention. do
It is sufficient to remove it to 25% by weight or less. Further, it is preferable that the temperature at which this product is water-dispersed is in the range of 20 to 60°C. The solids content of the resulting maleated alkyd resin emulsion composition ranges, but is not limited to, from 10 to 65% by weight, preferably from 25 to 60% by weight. Further, the average particle size measured by turbidity method is 0.6μ or less, preferably 0.3μ or less. If the average particle size is larger than 0.6μ, the sedimentation stability of the maleated alkyd resin emulsion will be poor, and the particles will not be stable, resulting in poor hydrolysis resistance, and the water resistance and corrosion resistance of the coating film will also be poor. Become. The turbidity method referred to here is based on the literature [Bull.Industrial.
Chemical.Research VoL.42 P145-152 (1964)]
The average particle diameter was determined using the calibration curve described in . Formula Absorbance ratio = Absorbance (430mμ) / Absorbance (700m
μ) In addition, a pigment, a pigment dispersant, a dryer, an antifoaming agent, a thickener, an aqueous resin other than those mentioned above, and the like can be optionally blended into the maleated aukid resin emulsion composition of the present invention. The coating film formed from the composition of the present invention is sufficiently crosslinked and cured at room temperature, but when heated in the presence or absence of an amino resin, etc., it cures in a short period of time and exhibits water resistance,
A coating film with good corrosion resistance etc. can be obtained. Next, the present invention will be explained in more detail with reference to Examples and Comparative Examples. Hereinafter, parts and % indicate parts by weight and % by weight. Example 1 Tall oil fatty acid (trade name “Etol FAX” manufactured by Arakawa Forest Products Co., Ltd.) 40% linoleic acid, linolenic acid
3.2%, oleic acid 32%, other 24.8%, iodine value 151) 599 parts, isophthalic acid 218 parts, benzoic acid
263 parts of pentaerythritol and 245 parts of pentaerythritol were placed in a four-necked flask equipped with a stirrer, a thermometer, and a branch condenser, and a dehydration condensation reaction was carried out at about 240°C for about 8 hours while stirring in the presence of an esterification catalyst. Resin acid value 2.7, Gardner viscosity W-X (75%
A butyl cellosolve solution) and an alkyd resin solution with a color number of 7 were obtained. Subsequently, the temperature was lowered to about 200°C, 50 parts of maleic anhydride was added, and the maleation reaction was carried out for about 3 hours. Total acid value 40.6, Gardner viscosity Z (60% butyl cellosolve solution) and color number 11
A maleated alkyd resin was obtained. Next, 126 parts of isopropyl alcohol was added to 420 parts of the maleated alkyd resin, and after neutralization with 1.0 equivalent of triethylamine, 750 parts of deionized water was added dropwise over about 1 hour to emulsify and disperse. Isopropyl alcohol was distilled off from the liquid at about 40°C by vacuum distillation. The properties of the resulting maleated alkyd resin emulsion and its coating film performance are shown in Table 2 below. Examples 2 to 7 Maleated alkyd resins were obtained using the formulations shown in Table 1 under exactly the same conditions as in Example 1. Further obtained maleated alkyd resin
A maleated alkyd resin emulsion was obtained by adding the formulation shown in Table 1 to 420 parts and carrying out production under exactly the same conditions as in Example 1. The properties of the resulting maleated alkyd resin emulsion and its coating film performance are shown in Table 2 below. Comparative Examples 1 to 2 Maleated alkyd resin emulsions were obtained using the formulations shown in Table 1 under exactly the same conditions as in Example 1. Furthermore, the formulation shown in Table 1 was added to 420 parts of the obtained maleated alkyd resin, and production was carried out under exactly the same conditions as in Example 1 to obtain a maleated alkyd resin emulsion. The properties of the resulting maleated alkyd resin emulsion and its coating film performance are shown in Table 2 below.

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Claims (1)

[Claims] 1 Modified with fats and/or fatty acids having an iodine value of 135 to 175, and containing in the fats and/or fatty acids components,
Oil length 35-80 containing 30% by weight or less of linoleic acid
A maleated alkyd resin emulsion composition prepared by neutralizing a maleated alkyd resin having an acid value of 10 to 70 obtained by reacting an alkyd resin with maleic anhydride and dispersing the same in water.