JPH0535193B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to an oxidation-curable water-dispersible resin composition, and more specifically, an acid-curable water-dispersible resin composition containing as a main component a reaction product of a maleated addition polymer having an oxidation-curable group and a water-insoluble addition polymer containing a hydroxyl group. The present invention relates to a water-dispersible resin composition. Conventionally, maleated addition polymers having drying oil fatty acid residues and/or semi-drying oil fatty acid residues connected to the main chain by ester bonds as side chains have been known to have a carbon-based main chain that is resistant to hydrolysis. Because it is a carbon bond, it has excellent storage stability.
Furthermore, when used as a resin for water-based paints, the coating film formed therefrom has advantages such as excellent water resistance, so it is widely put into practical use. However, on the other hand, because the main chain has many carbon-carbon bonds, it is highly oily, and when this polymer is made into an aqueous solution, it tends to have a high viscosity, so it is difficult to increase the solid content, which is a drawback that severely limits its use. There is. Therefore, the present inventors conducted extensive research with the aim of improving the drawback of high viscosity when making the maleated product of the conventional addition polymerized polymer solubilized in water. When a hydroxyl group-containing water-insoluble addition polymer is reacted, the resulting resin tends to become an aqueous dispersion rather than a water-soluble one when neutralized to make it water-soluble, resulting in low viscosity and high solidity. The present invention has been completed based on the discovery that the above-mentioned problems can be solved in just a few minutes. Thus, according to the present invention, (A) a maleated product of an addition polymer having as a side chain a drying oil fatty acid residue and/or a semi-drying oil fatty acid residue connected to the main chain by an ester bond [hereinafter, this ``Addition polymerization polymer (A)''
] and (B) a hydroxyl group-containing water-insoluble addition polymer [hereinafter, this may be abbreviated as "addition polymer (B)"] by neutralizing the reaction product. ,
An oxidation-curable water-dispersible resin composition obtained by dispersing in water is provided. The addition polymerization polymer having a drying oil fatty acid residue and/or a semi-drying oil fatty acid residue as a side chain, which forms the addition polymerization polymer (A) in the present invention, can be obtained, for example, as follows. One example is the esterification reaction of a homopolymer of a vinyl monomer containing a hydrous acid group or a glycidine group or a copolymer with a vinyl monomer containing no hydroxyl group or glycidyl group and a drying oil fatty acid and/or a semi-drying oil fatty acid. This is the way to do it. When the above-mentioned copolymer is used here, it is preferable that the copolymer contains 5% by weight or more of a hydrous acid group-containing or glycidyl group-containing vinyl monomer component. Another method is to add a drying oil fatty acid and/or a semi-drying fatty acid to glycidyl methacrylate or glycidyl acrylate to form a homopolymer of the monomer or a copolymer with the above-mentioned vinyl monomer. Also in this method, when a copolymer is produced, it is preferable that the copolymer contains 5% by weight or more of the above-mentioned additional monomer component. Here, the hydrous acid group-containing or glycidine group-containing vinyl monomer is, for example, allyl alcohol, 2
-Hydroxyethyl methacrylate, 2-hydroxyethyl acrylate, hydroxypropyl methacrylate, hydroxypropyl acrylate, glycidyl methacrylate, glycidyl acrylate, Metatsuku P (manufactured by NOF Chemical Co., Ltd., trade name)
etc. can be mentioned. Examples of the vinyl monomers mentioned above include styrene, vinyltoluene, α-methylstyrene, acrylonitrile, methacrylonitrile, esters of alcohols having 1 to 26 carbon atoms, preferably 1 to 18 carbon atoms, and acrylic acid or methacrylic acid, ethylene Ester of glycol monoalkyl ether or diethylene glycol monoalkyl ether (alkyl group has 1 to 8 carbon atoms) and acrylic acid or methacrylic acid, propylene glycol monoalkyl ether or dipropylene glycol monoalkyl ether (alkyl group has 1 to 8 carbon atoms) ) and acrylic acid or methacrylic acid, addition monomers of monocarboxylic acids having 4 to 26 carbon atoms other than drying oil fatty acids and semi-drying oil fatty acids, and glycidyl methacrylate or glycidyl acrylate, etc. It is desirable to use a monomer that has excellent copolymerizability with the glycidyl group vinyl monomer, glycidyl methacrylate-added fatty acid monomer, and glycidyl acrylate-added fatty acid monomer, and the resulting polymer is stable at high temperatures. Other monomers commonly used in radical polymerization such as butadiene, isoprene, chloroprene, pentadiene, vinyl acetate, vinyl chloride, and Beoba monomer (manufactured by Shell Chemical Co., USA, trade name) can also be used. In addition, as drying oil fatty acids and semi-drying oil fatty acids, fatty acid oil lengths can be used in the range of 5 to 90.
Preferably, it is in the range of 10 to 80, more preferably 15 to 60. Particularly preferred are those that contain a large number of double bonds, easily undergo maleation and polymerization reactions without gelation, and have good curability. In addition, corn oil fatty acids, cottonseed oil fatty acids, mustard oil fatty acids, oiticica oil fatty acids, peanut oil fatty acids, eno oil fatty acids, poppy oil fatty acids, rubber seed oil fatty acids, sesame oil fatty acids, tall oil fatty acids, tung oil fatty acids, dehydrated castor oil fatty acids, and hygienic oil fatty acids. Fatty acids etc. can also be used. The addition polymerization polymer (A) of the present invention is synthesized by maleating the addition polymerization polymer having a drying oil fatty acid residue and/or a semi-drying oil fatty acid residue connected to the main chain by an ester bond as a side chain. Ru.
Maleation may be carried out by a conventional method, and maleic anhydride may be reacted at about 120 to 250°C. In particular, when many hydroxyl groups remain in the polymer, it is preferable to esterify with a low-molecular or high-molecular acid such as acetic acid, propionic acid, or stearic acid to remove excess hydroxyl groups, and then maleate the polymer. The amount of maleation in the addition polymerization polymer (A) is such that the total acid value is from 5 to 300, preferably from 10 to 150, and more preferably from 20 to 100. If the acid value is too low than 5, the resulting water-dispersible resin composition will be difficult to form a stable water dispersion, while if the acid value is too high than 300, coating film performance such as water resistance will deteriorate. In addition, if the molecular weight is too low, it will not be possible to form a stable aqueous dispersion, and if it is too high, dispersion will be difficult, so the number average molecular weight is usually 800 to 500,000.
Preferably, it is in the range of 1,000 to 100,000. Additionally, addition polymerization polymer (B) used in the present invention
has a hydroxyl group and is substantially water-insoluble,
For example, it can be an addition polymerization polymer before maleation of the addition polymerization polymer (A). Since this product does not require a maleation reaction, drying oil fatty acids or semi-drying oil fatty acids having a conjugated double bond, which are not particularly suitable for the addition polymerization polymer (A), can also be freely used as a constituent thereof. However, since the addition polymerization polymer (B) is reacted with the addition polymerization polymer (A), it is not necessarily necessary to introduce a drying oil fatty acid or a semi-drying oil fatty acid that participates in the crosslinking reaction into the addition polymerization polymer (B). However, in order to ensure the crosslinking reaction of the reaction product, it is preferable to introduce the above-mentioned fatty acid.
That is, the oil length is in the range of 0 to 90, preferably 10 to 70, more preferably 20 to 60 in terms of coating film performance.
It is. Further, the amount of hydroxyl groups in the addition polymerization polymer (B) does not need to be large because the reaction between the hydroxyl groups and the acid anhydride groups in the addition polymerization polymer (A) is ensured.
The hydroxyl value can range from 0.5 to 300, more preferably from 1 to 50. If the amount of hydroxyl groups is too large, gelation tends to occur during the reaction. The reaction between the addition polymerization polymer (A) and the addition polymerization polymer (B) described above is carried out by the reaction between the acid anhydride group of the former and the hydroxyl group of the latter, and since they are reliably bonded, there is no need to worry about poor compatibility. Even with a combination of resins, a transparent and glossy coating film can be formed. The mixing ratio of addition polymerization polymer (A) and addition polymerization polymer (B) is 97/3 to 3/97, preferably 10/90 to 90/10, and more preferably 20/80 to 3/97 by weight.
It's 80/20. As the proportion of addition polymerization polymer (A) increases, the resulting dispersion tends to have a smaller particle size and a higher viscosity. The overall acid value is in the range of 3 to 150, preferably 5 to 100, more preferably 10 to 50. The higher the acid value, the more likely it is to be water-soluble, while the lower the acid value, the less water-dispersible it becomes. The reaction between addition polymerization polymer (A) and addition polymerization polymer (B) is carried out by mixing the two and then heating at 50 to 250°C for 0.5 to 4 hours. After the reaction, the remaining acid anhydride group is ring-opened with water, alcohol, amine, ammonia, etc., and then neutralized with a neutralizing agent such as an alkali metal, ammonia, amine, etc., and used after being dispersed in water. When using the water-dispersible resin composition obtained by the present invention as a paint binder, pigments, pigment dispersants, thickeners, dryers, other organic solvents, etc. may be added to it as necessary. used. The water-dispersible resin composition obtained according to the present invention is used as a cold-curable coating forming agent, but can also be used as a bake-drying coating forming agent. In this case, a hardening agent such as melamine can also be added. Furthermore, it can also be used for other applications such as resin processing agents. Although the water-dispersible resin composition of the present invention exhibits excellent performance by itself, it may be used in combination with other water-based resins for a wider range of applications. Next, the present invention will be explained in more detail with reference to Examples and Comparative Examples. Further, parts and percentages used below indicate parts by weight and percentages by weight unless otherwise specified. Example 1 RJ-100 (number average molecular weight 1600, OH content 7.7%
305 g of styrene/allylic alcohol copolymer (manufactured by Monsanto, USA), 302 g of linseed oil fatty acid, and 0.6 g of dibutyltin oxide were placed in a 4-necked flask, and a dehydration reaction was carried out at 240°C for 6 hours under xylene reflux. A resin with an acid value of 0.5 was obtained. To this, 37 g of maleic anhydride was added and an addition reaction was carried out at 200°C for 4 hours, and then the solvent was removed by vacuum distillation to obtain a maleated resin. In another 2 four-necked flasks, put RJ-101 (styrene/allylic alcohol copolymer with number average molecular weight 1150 and OH content 7.7%, manufactured by Monsanto Company, USA).
508g, linseed oil fatty acid 408g and phthalic anhydride 58g
g was added and dehydration was carried out in the same manner as above until the acid value reached 4 to obtain a water-insoluble resin. 427 g of the water-insoluble resin thus obtained was added to the maleated resin and stirred well. The viscosity of the mixture was Z ₅ in 75% butyl cellosolve solution. When this was heated at 150°C for 1 hour, the viscosity increased to _Z7 . 10 g of water was added to this mixture and left at 100°C for 1 hour. Example 2 660 g of RJ-101, 325 g of linseed oil fatty acid, 75 g of phthalic anhydride, and 90 g of benzoic acid were dehydrated and condensed in the same manner as in Example 1 to obtain water-insoluble resin 1 with an acid value of 6. Separately, 1015 g of RJ-101 and 1254 g of high diene fatty acids were dehydrated and condensed using the same method to obtain water-insoluble resin 2 having an acid value of 1.3. Next, 500 g of the former resin (1) and 100 g of the latter resin (2) were added to 400 g of the maleated resin obtained in Example 1, and the mixture was thoroughly stirred. The viscosity of the mixture was Z ₅ in 75% butyl cellosolve solution. When this was heated at 200°C for 1 hour, it became Z ₆ +. 7 g of water was added to the reaction product thus obtained, and the mixture was further reacted at 100° C. for 1 hour. Example 3 660 g of RJ-101, 325 g of high diene fatty acid, 43 g of phthalic anhydride, and 143 g of benzoic acid were condensed in the same manner as in Example 1 to an acid value of 6 to obtain a water-insoluble resin. 417 g of this resin was added to 626 g of the maleated resin obtained in Example 1 and mixed well. The viscosity of the mixture was Z _3-4 in 75% butyl cellosolve solution. This was heated at 200° C. for 2 hours and reacted until the viscosity reached Z ⁺ ₅ . 10 g of water was added to the reaction product thus obtained, and the mixture was further reacted at 100° C. for 1 hour. Example 4 305 g of RJ-101 and 376 g of linseed oil fatty acid were subjected to a dehydration condensation reaction in the same manner as in Example 1, and oxidized.
0.4 of the resin was obtained, 41 g of maleic anhydride was added thereto, and the reaction was carried out at 200° C. for 4 hours to obtain a maleated resin. To this was added 465 g of the water-insoluble resin (2) synthesized in Example 2 using the hydene fatty acid, and the mixture was thoroughly stirred. The viscosity at this time was Z to Z ₁ for a 75% butyl cellosolve solution. This product was heated at 200° C. for 2 hours to react until Z ⁺ ₄ . 11 g of water was added to the reaction product thus obtained, and the mixture was further heated at 100° C. for 1 hour. Comparative Example 1 A composition having the same composition as Example 3, but
The maleated resin was simply mixed after previously ring-opening its acid anhydride groups. Comparative Example 2 A maleated resin synthesized in the same manner as in Example 1 except that the amount of maleic anhydride was changed to 60% (22 g) was used to open the acid anhydride group in the same manner as in Example 1. I made a circle. Comparative Example 3 After performing a dehydration condensation reaction in the same manner as in Example 1 using 508 g of RJ-101, 470 g of linseed oil fatty acid, and 41 g of phthalic anhydride, 38 g of maleic anhydride was added to perform a maleation reaction. Ta. Then, the acid anhydride groups of the maleated resin obtained were ring-opened with water. Comparative Example 4 The same formulation as in Comparative Example 3 was repeated except that the amount of maleic anhydride was changed to 27 g. The compositions obtained in the above Examples and Comparative Examples were neutralized in equivalent amounts with triethylamine, dispersed in water, and their properties and coating performance were examined. The results are shown in Table 1 below.

【table】

[Table] Shows the pencil hardness after hardening.
(Note 2) The state of the coated surface was examined after the coated film had been dried for one week and immersed in water for 5 hours.

Claims (1)

[Scope of Claims] 1 (A) An addition polymer having a hydroxyl group or a glycidyl group and having a number average molecular weight of 800 to 500,000,
Oil length 5 having a drying oil fatty acid residue and/or semi-drying oil fatty acid residue as a side chain connected by an ester bond to the main chain obtained by esterifying a drying oil fatty acid and/or a semi-drying oil fatty acid. ~90
(B) Addition polymer of lysidyl, a hydroxyl group-containing water-insoluble addition polymer with a hydroxyl value of 0.5 to 300. maleide (A)
and addition polymerization polymer (B) in weight ratio.
The reaction product obtained by esterifying the acid anhydride group of (A) and the hydroxyl group of (B) at a ratio of 97/3 to 3/97 is neutralized, and the reaction product is dissolved in water. An oxidation-curable water-dispersible resin composition for paints obtained by dispersing it in.