JP2580588B2 - Method for producing graft-modified alkyd resin - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial application field) The present invention relates to an alkyd resin for paint, and more specifically,
The present invention relates to a method for producing an alkyd resin for coatings which can be used substantially without adding a pigment dispersant and has extremely excellent pigment dispersibility.

(Prior art) Conventionally, there is no perfect pigment dispersibility of a coating resin, and a method of adding a surfactant, a silicone compound, or the like as a pigment dispersant has been used for improving the pigment dispersibility.

Paints using an alkyd resin as a vehicle are generally superior in dispersibility of organic pigments, carbon black, etc., to other vehicles such as acrylic resins, but still have insufficient pigment dispersibility, and are not suitable for color mixing. At present, satisfactory products have not been obtained in terms of color separation and the like.

(Problems to be Solved by the Invention) The inventors of the present invention have conducted intensive studies to improve the above-mentioned disadvantages such as pigment dispersibility and color separation at the time of color mixing, and as a result, the alkyd resin contained a phosphorus atom-containing vinyl monomer. It has been found that the graft dispersibility of the alkyd resin itself can be drastically improved without adding a surfactant and a pigment dispersant of a silicone compound content by graft polymerization of the alkyd resin itself. Was completed.

[Constitution of the Invention] (Means for Solving the Problems) In summary of the present invention, the present invention is characterized in that an alkyd resin is subjected to a 0.01 to 5.0% by weight graft reaction of a phosphorus atom-containing vinyl monomer, The present invention relates to a method for producing a graft-modified alkyd resin having excellent pigment dispersibility.

 Hereinafter, the configuration of the present invention will be described in detail.

The alkyd resin component which is a graft base used in the present invention may be any one having an unsaturated point for graft copolymerization with a phosphorus atom-containing vinyl monomer component described below, and is not particularly limited. Absent.

That is, the alkyd resin component as the graft base used in the present invention includes all alkyd resins such as short oil alkyd resin, medium oil alkyd resin, long oil alkyd resin, phenol resin modified alkyd resin, epoxy modified alkyd resin, oil-free alkyd resin, and the like. Is targeted.

Pigments used in the production of such alkyd resins generally include fats and oils and fats and oils, mono- or polybasic acids, polyhydric alcohols, and modifiers.

For example, as oils and fats and oil fatty acids, linseed oil,
Oils and fats such as soybean oil, tung oil, rice bran oil, coconut oil, palm oil, safflower oil, fishing oil, hydrogenated fishing oil, castor oil, dehydrated castor oil, polymerized oils such as dehydrated castor oil, linseed oil, tung oil, and alkyd resin When is manufactured by the fatty acid method, fatty acids of the above fats and oils or tall oil fatty acids are used.

Phthalic anhydride, as monobasic or polybasic acids
Phthalic acid, isophthalic acid, terephthalic acid, head acid, trimellitic acid, pyromellitic acid, succinic anhydride, succinic acid, oxalic acid, adipic acid, sebacic acid, benzoic acid paratertiary benzoic acid, parahydrobenzoic acid, rosin, Further, monovalent carboxylic acids and polyvalent carboxylic acids such as hydrogenated products and methyl ester products thereof are used.

As polyhydric alcohols, ethylene glycol, propylene glycol, neopentyl glycol,
1,6-hexanediol, 1,3-butylene glycol, hydrogenated bisphenol A, trimethylolpropane, trimethylolethane, glycerin, pentaerythritol, 1,4
Polyhydric alcohols such as cyclohexane dimethanol,
Further, these alkylene oxide adducts, Cardura E, or bisphenol-based, alicyclic-based, and phenol-based epoxy adducts can be used in any desired ratio.

The alkyd resin component used in the present invention desirably has an unsaturated point derived from an oil or the like subjected to a graft reaction with a phosphorus atom-containing vinyl monomer component described below.

In addition, in the present invention, an unsaturated point to be subjected to the graft reaction may be secured in the alkyd resin component as described below.

(I) An unsaturated dicarboxylic acid such as maleic acid, fumaric acid, itaconic acid or the like is used in advance as a raw material in the production of an alkyd resin to carry out a condensation reaction, or an unsaturated group is formed by reacting a dicarboxylic anhydride with a hydroxyl group of an alkyd resin. How to introduce.

This method is the most preferred in view of the pigment dispersibility, which is the object of the present invention, and the amount of unsaturated dicarboxylic acid used is 0.01 to 5% by weight, particularly preferably 0.05 to 3% by weight. If it is less than 0.01% by weight, the effect is hard to expect,
On the other hand, if it exceeds 5% by weight, it becomes a resin having a remarkably high viscosity, which causes a problem in the stability as a paint.

(Ii) General formula (R ₁ : hydrogen atom or methylol group, R ₂ : C ₁ -C ₅ alkyl group) A vinyl monomer containing an isocyanate group represented by the following formula: is added to the residual hydroxyl group of the alkyd resin.

(Iii) A method of adding glycidyl (meth) acrylate to the remaining carboxy groups of the alkyd resin.

The above is a typical example of introducing an unsaturated group into an alkyd resin, which allows the alkyd resin component to be graft-copolymerized with a phosphorus atom-containing vinyl monomer described below. It goes without saying that the method is not limited to the method described above.

Next, as a typical example of the phosphorus atom-containing vinyl monomer to be graft-reacted to the alkyd resin component, which is an essential condition of the present invention, a general formula: Among them, mono (2-methacryloyloxyethyl) acid phosphate, diphenyl (2-methacryloyloxyethyl) phosphate, dioctyl (2-methacryloyloxyethyl) phosphate, etc. are typical examples. It is. The amount used is 0.01 to 5% by weight, more preferably 0.05 to 3% by weight, based on the alkyd resin. If the content is less than 0.01% by weight, the effect cannot be expected, and if it exceeds 5% by weight, the stability of the coating composition is disadvantageously deteriorated. The graft reaction of the phosphorus atom-containing vinyl monomer to the alkyd resin may be performed according to a usual graft reaction. Most simply, the above-mentioned vinyl monomer containing a phosphorus atom may be subjected to a graft reaction in the presence or absence of a radical polymerization initiator in the presence of an alkyd resin having an unsaturated group that can undergo a graft reaction.

In the present invention, at the time of graft copolymerization, other vinyl monomers can be used in addition to the phosphorus atom-containing vinyl monomer component. For example, styrene such as styrene and P-tert-butylstyrene and derivatives thereof; alkyl acrylates such as methyl acrylate, ethyl acrylate and butyl acrylate; alkyl methacrylates such as methyl methacrylate, ethyl methacrylate and butyl methacrylate; acids such as acrylic acid and methacrylic acid Monomer; hydroxy (meth) acrylate such as 2-hydroxy (meth) acrylate; N, N-dialkylaminoalkyl (meth) acrylate, N, N-dialkylaminoalkyl (meth) acrylamide, (meth) acrylamide, N-methylol ( (Meth) acrylamide, N, N
-Dialkyl (meth) acrylamide, diacetone (meth) acrylamide, acryloyl, N-vinylmorpholine, N-alkoxymethyl (meth) acrylamide,
Nitrogen atom-containing vinyl monomers such as N-vinylpyrrolidone, acrylonitrile, N, N-dialkylaminoalkylmaleimide and vinylimidazole can be used in combination.

The present invention is characterized in that a phosphorus atom-containing vinyl monomer is grafted to an alkyd resin.However, when the nitrogen atom-containing vinyl monomer is used in combination with the phosphorus atom-containing vinyl monomer to modify the alkyd resin, Even when a large number of pigments are used, they exhibit excellent pigment dispersing ability, which is preferable.

Further, in the graft copolymerization of the present invention, a polymerization initiator such as azobisisobutyronitrile, benzoyl peroxide, tertiary butyl perbenzoate, tertiary butyl hydroxide, ditertiary butyl hydroxide, cumene hydroxide or the like is used. Can be done.

The graft copolymerization reaction can be carried out without diluting the alkyd resin with an organic solvent. However, generally, the graft copolymerization reaction is performed in a solution diluted with an organic solvent. Organic solvents used include aromatic solvents such as xylene, toluene, swazole 1000, swazole 1500 (manufactured by Cosmo Oil); ethyl acetate, butyl acetate,
Esters such as cellosolve acetate; ketones such as methyl ethyl ketone and methyl isobutyl ketone; alcohols such as 1-butanol and 2-butanol cellosolve; aromatics, aliphatics and fatty acids such as mineral spirits and swazol 310 A mixture of cyclic mixed systems can be used alone or as a mixture.

The thus obtained graft-modified alkyd resin of the present invention can also be used as a lacquer coating by using another vinyl resin or nitrocellulose in combination, and a crosslinking agent component such as polyisocyanate, amino resin, or epoxy resin. It can be used as a curable coating by containing it.

Furthermore, in the case of a graft-modified alkyd resin using a drying oil or a semi-drying oil, a dryer (cobalt-based, zirconium-based, lead-based, manganese-based organic metal salt) should be added to use as an air-curable coating. Can be done.

It goes without saying that the above-mentioned graft-modified alkyd resin of the present invention can be used by adding a well-known and commonly used coating additive or a curing accelerator effective for the crosslinking agent component.

(Examples) Hereinafter, the present invention will be described in more detail based on examples, but the present invention is not limited to these examples unless it departs from the technical idea thereof. Unless otherwise specified, all components used are on a weight basis.

<Production Example 1> 370 parts of rice bran fatty acid and phthalic anhydride 4 were placed in a four-necked flask equipped with a stirring rod, a thermometer, a cooling tube, a nitrogen introduction tube, and a heating device.
25 parts, 100 parts of pentaeristol, 150 parts of glycerin, and 50 parts of ethylene glycol were heated to 180 ° C. in a nitrogen atmosphere and maintained for 2 hours, and then heated to 230 ° C. over 1.5 hours and maintained there. The reaction was allowed to proceed until the acid value reached 8.5, and after the reaction was completed, 530 parts of xylene was added.

The resin solution thus obtained had a nonvolatile content of 65.0%, a viscosity (Gardner at 25 ° C.) of Z ₈ , and an acid value of 5.0. Hereinafter, this is referred to as (resin solution A).

<Production Example 2> In a four-necked flask equipped with a stirrer, a thermometer, a cooling tube, a nitrogen introduction tube, and a heating device, 1000 parts of (Resin Solution A) of <Production Example 1>, 2-methacryloyloxyethyl acid phosphate 5.0 Then, 88.0 parts of 1-butanol and 5.0 parts of ditertiary butyl peroxide were added, and the mixture was stirred well, heated to 118 ° C., and kept as it was for 4 hours to carry out a graft copolymerization reaction. After the reaction, the mixture was cooled to obtain a resin solution.

The resin solution thus obtained had a nonvolatile content of 60.0%, a viscosity (Gardner at 25 ° C.) of Z ₁ -Z ₂ , and an acid value of 4.5. Less than,
This is called (resin solution B).

<Production Example 3> 1000 parts of (Resin Solution A) and 3.0 parts of maleic anhydride were added to a four-necked flask equipped with a stirring rod, a thermometer, a cooling tube, a nitrogen introduction tube, and a heating device, and the mixture was stirred and heated to 135 ° C. After heating for 1 hour, cool to below 80 ° C and add 1-butanol
100 parts, 2-methacryloyloxyethyl acid phosphate 3.0 parts, dimethylaminoethyl methacrylate
3.0 parts and 5.0 parts of ditertiary butyl peroxide were added, and the mixture was stirred well, heated to 118 ° C., and held for 6 hours to carry out a graft copolymerization reaction. After completion of the reaction, the mixture was cooled to obtain a resin solution.

The resin solution thus obtained had a nonvolatile content of 60.0%, a viscosity (Gardner at 25 ° C.) of Z ₂ , and an acid value of 6.0. Hereinafter, this is referred to as (resin solution C).

<Production Example 4> 250 parts of isophthalic acid and adipic acid 3 were placed in a four-necked flask equipped with a stirring rod, a thermometer, a cooling tube, a nitrogen introduction tube, and a heating device.
80 parts, 150 parts of trimethylolpropane, 170 parts of neopentyl glycol and 200 parts of 1.6-hexanediol were added, the temperature was raised to 160 ° C. in a nitrogen atmosphere, and 220
The temperature was raised to ° C. and kept as it was. The reaction was proceeded until the acid value reached 7, and after the reaction was completed, the mixture was cooled to 180 ° C., and 830 parts of xylene and 150 parts of cellosolve acetate were added.

The resin solution thus obtained had a nonvolatile content of 50%, a viscosity (Gardner of 250 ° C.) X, and an acid value of 3.0. Hereinafter, this is referred to as (resin solution D).

<Production Example 5> In a four-necked flask equipped with a stir bar, a thermometer, a cooling tube, a nitrogen introduction tube, and a heating device, 1000 parts of (Resin Solution D) of Production Example 4, 2 parts of glycidyl methacrylate, and styrene
10 parts, 5 parts of methyl methacrylate, 3 parts of diphenyl (2-methacryloyloxyethyl) phosphate, 12 parts of xylene, and 15 parts of ditertiary butyl methacrylate, are stirred well, and then heated to 140 ° C.
The graft copolymerization reaction was performed while maintaining the same temperature for 5 hours. After the reaction, the solution was cooled to obtain a resin solution.

The solution of the graft-modified alkyd resin obtained here is
A nonvolatile content of 50.0%, viscosity at Z-Z _1, and an acid value of 3.
Was 3. Hereinafter, this is abbreviated as (resin solution E).

<Production Example 6> 1000 parts of the above (resin solution D), 5.0 parts of isocyanateethyl methacrylate, and 2.5 parts of 2-methacryloyloxyethyl acid phosphate in a four-necked flask equipped with a stirring rod, a thermometer, a nitrogen inlet tube, a condenser tube, and a heating device. Parts, 1.5 parts of dimethylaminopropyl acrylate, 5.0 parts of ditertiary butyl peroxide, and 8 parts of xylene. The mixture was stirred well, heated to 135 ° C., and kept at that temperature for 5 hours to carry out a graft copolymerization reaction. After the reaction, the mixture was cooled to obtain a resin solution.

The resin solution thus obtained has a nonvolatile content of 50.0% and a viscosity of 5%.
Z ₁ -Z ₂ and the acid value were 3.3. Hereinafter, this is referred to as (resin solution F).

<Example 7> 1000 parts of the above (resin solution D), 2.0 parts of maleic anhydride, and 2.5 parts of 2-methacryloyloxyethyl acid phosphate in a four-necked flask equipped with a stirrer, a thermometer, a nitrogen inlet tube, a condenser tube, and a heating device. Parts, styrene 4.5 parts, xylene 6
And 3.0 parts of ditertiary butyl peroxide, and the mixture was stirred well, heated to 135 ° C., and held for 5 hours to carry out a graft copolymerization reaction. After the reaction, the mixture was cooled to obtain a resin solution.

The resin solution thus obtained has a nonvolatile content of 50%, a viscosity Y,
The acid value was 4.2. Hereinafter, this is referred to as (resin solution G).

<Production Example 8> 400 parts of coconut oil, 80 parts of trimethylpropane, and 0.2 parts of lithium hydroxide were added to a four-necked flask equipped with a stirring rod, a thermometer, a cooling tube, a nitrogen introduction tube, and a heating device.
The temperature was raised to ° C. and maintained for 1 hour. After cooling to 180 ° C., 190 parts of isophthalic acid, 180 parts of phthalic anhydride, 100 parts of trimethylolpropane, 100 parts of pentaerythritol, 15 parts of fumaric acid
The temperature was raised to 230 ° C., and the reaction was continued until the acid value reached 11. After completion of the reaction, the mixture was cooled to 180 ° C., and 650 parts of xylene was added.

The resin solution thus obtained had a nonvolatile content of 60.0%, a viscosity (Gardner at 25 ° C.) T, and an acid value of 6.0. Hereinafter, this is referred to as (resin solution H).

<Production Example 9> 1000 parts of the above (resin solution H), 3.0 parts of styrene, 2.5 parts of 2-methacryloyloxyethyl acid phosphate were placed in a four-necked flask equipped with a stirring rod, a thermometer, a nitrogen inlet tube, a cooling tube, and a heating device. 5 parts of butyl cellosolve and 3.0 parts of ditertiary butyl peroxide were added, and the mixture was stirred well, heated to 135 ° C., and held for 5 hours to carry out a graft copolymerization reaction. After the reaction, the mixture was cooled to obtain a resin solution.

The resin solution thus obtained had a nonvolatile content of 50%, a viscosity (Gardner at 25 ° C.) of VW, and an acid value of 6.5. Hereinafter, this is referred to as (resin solution I).

<Production Example 10> 400 parts of linseed oil, 100 parts of dehydrated castor oil in a four-necked flask equipped with a stirring rod, a thermometer, a nitrogen inlet tube, a cooling tube, and a heating device.
, 50 parts of benzoic acid, 90 parts of pentaerythritol and 0.5 part of lithium hydroxide were added, the temperature was raised to 240 ° C in a nitrogen atmosphere, and the temperature was maintained for 1 hour. Next, the mixture was cooled to 180 ° C., 300 parts of phthalic anhydride and 100 parts of pentaerythritol were added, the temperature was raised to 230 ° C., the temperature was maintained as it was, and the reaction was allowed to proceed until the acid value reached 8.0. After the completion of the reaction, the mixture was cooled to 180 ° C., and 650 parts of Swazole 310 (manufactured by Cosmo Oil) was added.

The resin solution thus obtained had a nonvolatile content of 60.0%, a viscosity (Gardner at 25 ° C.) of VW and an acid value of 4.4. Less than,
This is called (resin solution J).

<Production Example 11> In a four-necked flask equipped with a stirring rod, a thermometer, a nitrogen inlet tube, a cooling tube, and a heating device, 1000 parts of the above (resin solution J), 2-
Methacryloyloxyethyl acid phosphate 2.5
Then, 3.0 parts of xylene and 3.0 parts of ditertiary butyl peroxide were added, and the mixture was stirred well, heated to 145 ° C., and kept as it was for 5 hours to carry out a graft copolymerization reaction. After the reaction, the mixture was cooled to obtain a resin solution.

The resin solution thus obtained had a nonvolatile content of 50.0%, a viscosity (Gardner of 25 ° C.) W, and an acid value of 4.0. Hereinafter, this is referred to as (resin solution K).

The dispersibility of the pigment was evaluated for the resin solutions obtained in each of the above Production Examples. In order to evaluate the pigment dispersibility, the pigment content (PW
C) Add a pigment so that it becomes as follows, and add 30 parts of xylene,
100 parts of glass beads were added, and the mixture was kneaded with a sand mill for 1 hour, and then the glass beads were filtered to obtain a color base. The pigment was ground on the basis of this color, and the presence or absence of aggregation of the pigment was examined. Thereafter, for Comparative Examples 1-2 and Examples 1-5, 30 parts of thinner (xylene: 1-butanol = 7: 3)
Diluted. Further, Comparative Examples 3 and 4 and Examples 6 and 7 were diluted with 30 parts of xylene.

The diluted paint was applied to a tin plate and allowed to stand at room temperature for 24 hours, and then the gloss of the paint film was compared.

Each result is used as primary color
These are summarized in the table.

Furthermore, 30% of melamine resin (solid content) is compared with 70% of resin solid content in the diluted paints of Comparative Examples 1-2 and Examples 1-5.
Super Beckamine G-821-60 (an isobutyl etherified melamine resin manufactured by Dainippon Ink and Chemicals, Inc.) was added to prepare a baking-type paint.

In Comparative Example 3 and Example 6, 30% of nitrocellulose (solid content) is 60% of the resin solid content in the diluted paint.
[1/2 "nitrocellulose (Asahi Kasei KK) 20% solution (thinner composition; xylene / toluene / ethyl acetate / butyl acetate / cellsolve / 1-butanol = 30/20/10/30/5 /
5)] A lacquer type paint was prepared by adding 10% of a plasticizer dioctyl phthalate (Dainippon Ink and Chemicals KK).

For Comparative Example 4 and Example 7, 6% cobalt naphthenate 1.0%, lead naphthenate 2.0%, and MEK ketoxime 1.0% were added to the resin solid content in the diluted paint, and an air-curable cold curing paint was added. Was prepared. To 80% of each white paint prepared in this way, 20% of each color paint was added, spray-coated, and further flow-coated thereon, and then Comparative Examples 1 to 2 and Examples 1 to 5 After baking at 20 ° C. for 20 minutes, the color difference between the spray-coated portion and the flow-coated portion was determined. For Comparative Examples 3 and 4, and Examples 6 and 7, the color difference was determined after standing for one day. The results are summarized in Table 1.

[Effects of the Invention] A graft-modified alkyd resin obtained by graft-copolymerizing a phosphorus atom-containing vinyl monomer to the alkyd resin of the present invention is excellent in millability and dispersibility for various pigments.
Therefore, the graft-modified alkyd resin of the present invention can form an excellent coating film with little difference in color tone due to differences in the coating method when glossing or mixing colors without using a pigment dispersant.

Claims (1)

(57) [Claims] 1. A method for producing a graft-modified alkyd resin, which comprises subjecting an alkyd resin to a graft reaction of 0.01 to 5.0% by weight of a phosphorus atom-containing vinyl monomer.