JP2936360B2 - Water-dilutable coating composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water-dilutable coating composition and, more particularly, to a low-odor aqueous coating composition which generates very little odor during coating or drying of a coating film.

[0002]

2. Description of the Related Art Water-based paints are non-polluting and excellent in work safety, have less pungent odor than organic solvent-based paints, and are widely used for interior coating of buildings. However, while the water-based paint is said to have a low irritating odor, it still generates an irritating odor, an unpleasant odor, a bad odor, an unpleasant odor, etc. at the time of painting or drying. Not good for health. Such an odor is a particularly serious problem in the interior coating of a building having a small opening, and there is a strong demand for reducing the odor of the coating.

[0003]

[Means for Solving the Problems] The present inventors have conducted intensive studies to solve the above problems, and as a result, the odor of the water-based paint is largely caused by the composition of the water-based resin and the volatile film-forming agent. As a result, by polymerizing a monomer component having a specific composition in the presence of a reactive emulsifier, and reducing the content of unreacted components to an emulsion resin, by using a specific plasticizer, The defect was eliminated, and the object of the present invention was achieved.

That is, the present invention relates to (A) acrylic acid 2
-Ethylhexyl, alkyl methacrylate (C1-4)
One or two selected from styrene, n-butyl acrylate, and a vinyl monomer having two or more polymerizable double bonds in one molecule, as essential components, an ester and (meth) acrylic acid. A monomer component comprising at least one species is emulsion-polymerized in the presence of an emulsifier having a radical (co) polymerizable carbon-carbon double bond, and the unreacted monomer content is 0.06% by weight or less. One or more selected from emulsion resins and (B) dialkyl phthalate (C6-10) esters and alkyl (C2-6) esters of 2,2,4-trimethyl-1,3-pentanediol monoisobutyrate And a low-odor water-dilutable coating composition (hereinafter sometimes abbreviated as “the present composition”) containing a plasticizer as a main component.

Hereinafter, the present invention will be described in detail.

The alkyl methacrylate used for the synthesis of the component (A) is an esterified product of methacrylic acid and an alcohol having 1 to 4 carbon atoms, and has one polymerizable double bond in one molecule. Is a monomer. Specific examples include methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, i-propyl methacrylate, n-butyl methacrylate, i-butyl methacrylate, t-butyl methacrylate and the like. Further, a hydroxyl group, a glycidyl group and the like may coexist in the molecule.

The proportion of the above monomer in the component (A) is not particularly limited. For example, 25 to 80% by weight of 2-ethylhexyl acrylate, 10 to 75% by weight of an alkyl (C1 to 4) methacrylate ester and (meth)
Acrylic acid is preferably in the range of 0.1 to 10% by weight. Styrene and n-butyl acrylate are suitably used in an amount of 50 parts by weight or less per 100 parts by weight of these monomers. Polyfunctional vinyl monomers are those monomers 10
10 parts by weight or less per 0 parts by weight is suitable.

The polyfunctional vinyl monomer has two or more polymerizable double bonds in one molecule. Examples thereof include ethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, and 1,6-hexane. Examples thereof include diol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, and divinylbenzene.

The reactive emulsifier used for the preparation of the component (A) has a radical (co) polymerizable carbon-carbon double bond in the molecule of the emulsifier, and is a nonionic reactive emulsifier or an anionic reactive emulsifier. And so on.

Examples of the nonionic type include anionic type such as α, β-unsaturated carboxylic acid monoester, alkylene oxide adduct of (meth) acrylic acid, and (meth) acrylic acid ester of polyoxyalkylene monoallyl ether. Examples thereof include ammonium sulfonate having a polymerizable unsaturated group in the molecule, alkali metal sulfonate, ammonium sulfate, and alkali metal sulfate. Examples of these commercially available products include Latemul S-120A, Latemul S-180A, Latemul S-180 manufactured by Kao Corporation, Eleminol JS-2 manufactured by Sanyo Chemical Co., Ltd., and Aqualon HS manufactured by Daiichi Kogyo Seiyaku Co., Ltd. -10, Newcol 707SF and Antox MS-60 manufactured by Nippon Emulsifier Co., Ltd.

The use amount of these reactive emulsifiers is 0.01 to 10% by weight, preferably 0.05 to 5% by weight, based on the total weight of the polymerizable monomer.

The reactive emulsifier is chemically bonded to the emulsion particles, has low volatility, and is used in a relatively small amount, so that the odor caused by the emulsifier is extremely small.

The component (A) can be obtained by subjecting the above components to a usual emulsion polymerization method, for example, a batch charging method, a monomer addition method, a pre-emulsion addition method, a split addition method, or the like.

[0014] The content of the unreacted monomer component in the component (A) is defined as 50% by weight of the resin solid content of the component (A).
Prepared by gas chromatography mass spectrometry (GC
-MC), G Column,
G-300 and G-100, column temperature 11
It can be measured under the condition of 0 ° C. If the unreacted monomer content is more than 0.06% by weight, the odor is undesirably increased. The unreacted monomer component content is the above monomer component, polymerization time, polymerization temperature, type of catalyst, additional catalyst,
It can be adjusted by appropriately selecting vacuum distillation or the like.

The component (B), a dialkyl phthalate (C
Examples of the 6-C10) ester include dihexyl phthalate, diheptyl phthalate, dinormal octyl phthalate, di-2-ethylhexyl phthalate, dioctyl phthalate (2-ethylhexyl), dinonyl phthalate, and didecyl phthalate. Can be

Texanol alkyl (C2-C
6) The ester is an alkyl ester having 2 to 6 carbon atoms of texanol (2,2,4 trimethyl 1,3 pentanediol monoisobutyrate), for example, texanol ethylate, texanol propylate, texanol Butyrate, texanol isobutyrate, texanol pentylate, texanol hexylate and the like.

The amount of the component (B) can be arbitrarily selected according to the purpose, but is preferably 2 to 60 parts by weight, particularly preferably 5 to 40 parts by weight, per 100 parts by weight of the resin solid content of the component (A). When the amount is less than 2 parts by weight, the film-forming property is deteriorated, and when the amount is more than 60 parts by weight, the coating property becomes insufficient.

As the component (B), a dialkyl phthalate and / or a texanol alkyl ester are used. Of these, it is preferable that the latter contains 50% by weight or more based on the total weight of the former.

The present composition contains the above-mentioned components (A) and (B) as main components, and further contains ordinary pigments, fillers, lubricants, dispersants, wetting agents, thickeners, rheology control agents, Antifoaming agent, film-forming aid, antifreezing agent, preservative, fungicide,
A pH adjuster, a rust inhibitor and the like can be appropriately compounded within a range that does not inhibit the reduction of odor. It is preferable that all of them have low odor.

[0020]

According to the present composition, an emulsion resin (A) component in which a specific monomer component is polymerized in the presence of a reactive emulsifier and the content of an unreacted monomer component is minimized, and a component (B) having a low odor. As a main component, compared to conventional water-based paints, it is possible to significantly reduce the irritating odor during paint production, painting and film formation, resulting in a cleaner painting environment and safer Its effects, such as improvement of hygiene and prevention of contamination, are extremely large. Moreover, it has excellent paintability and film forming properties.

[0021]

The present invention will be described in more detail with reference to the following Examples and Comparative Examples, in which "parts" means "parts by weight" and "%" means "% by weight". .

Production Example 1 of Component (A) Production of Component (A-1): Deionized into a reaction vessel (2 liter flask) equipped with a stirrer, thermometer, reflux condenser and nitrogen gas inlet tube. Water 72
8 parts and reactive emulsifier latemul S-180A (manufactured by Kao Corporation, anionic reactive emulsifier, solid content 50
%), And the inside of the vessel was replaced with nitrogen gas, and then heated to a temperature of 80 ° C. Then, 546 parts of 2-ethylhexyl acrylate, 234 parts of methyl methacrylate,
80 parts of a monomer mixture consisting of 16 parts of methacrylic acid and 4 parts of 1,6-hexanediol diacrylate and 8 parts of a 5% aqueous potassium persulfate solution were charged into a reaction vessel, and stirring was continued for 1 hour while maintaining the temperature at 80 ° C. Was. Thereafter, volatile components other than water were sufficiently removed under reduced pressure.
Then, the reaction product was heated to 80 ° C., and 720 parts of the remaining monomer mixture and 24 parts of a 5% aqueous potassium persulfate solution were dropped into the reaction vessel at a constant rate over 4 hours.

During these operations, the temperature of the reaction vessel was raised to about 80
Stirring was continued while maintaining the temperature. After completion of the dropwise addition, stirring was continued for 1 hour while maintaining the reaction vessel at 80 ° C. Thereafter, 16 parts of a 5% aqueous potassium persulfate solution was added as an additional catalyst, and the mixture was stirred at 80 ° C. for 2 hours. Thereafter, the reaction vessel was cooled, 7.6 parts of a 25% aqueous ammonia solution was added, and the contents of the vessel were filtered with a 100-mesh wire mesh.
(A) The component (A-1) was obtained. Resin solid content is 50
%, And the unreacted monomer content was 0.05%.

Production Example 2 of Component (A) Production of Component (A-2): In a reaction vessel similar to that of Production Example 1, 300 parts of deionized water and Newcol 707SF (anion manufactured by Nippon Emulsifier Co., Ltd.) 2.7 parts of a system-reactive emulsifier solid content 30%),
After the inside of the vessel was replaced with nitrogen gas, the vessel was heated to a temperature of 80 ° C. Meanwhile, an emulsion of a monomer having the following composition was prepared in a container having a capacity of 2 liters. Deionized water 460 parts Antox MS-60 Note 1) 21.3 2-Ethylhexyl acrylate 490 Styrene 78 Methyl methacrylate 20 Methacrylic acid 12 (1081.3 in total) Note 1) Anionic reaction by Nippon Emulsifier Co., Ltd. Emulsifier,
90% solids content. Before use, the odor was sufficiently removed by degassing under reduced pressure.

After charging 8 parts of a 5% aqueous potassium persulfate solution into the reaction vessel, the mixture is stirred for 15 minutes, and then 1081.3 parts of the above monomer emulsion and 18 parts of the 5% aqueous potassium persulfate solution are respectively added at a constant rate over 3 hours. It was dropped into the reaction vessel. During these operations, the temperature of the reaction vessel was raised to 80
C. and kept stirring. After completion of the dropwise addition of the monomer emulsion and the aqueous solution of potassium persulfate, an additional 3
After stirring for 0 minutes, methyl methacrylate 137 was added.
Parts, a monomer mixture consisting of 59 parts of 2-ethylhexyl acrylate and 4 parts of methacrylic acid (200 parts in total)
And 6 parts of a 5% aqueous potassium persulfate solution were added dropwise to the reaction vessel at a constant rate over time. During these operations, the temperature of the reaction vessel was maintained at 80 ° C., and stirring was continued. After completion of the dropwise addition, stirring was continued for 1 hour while maintaining the reaction vessel at 80 ° C. Thereafter, 16 parts of a 5% aqueous potassium persulfate solution was added to the reaction vessel as an additional catalyst, and
For 2 hours. Then, the reaction vessel is cooled and 2
7.6 parts of 5% aqueous ammonia was added, and the contents of the reaction vessel were filtered through a 100-mesh wire mesh to obtain component (A) (A-2).
I got The resin solid content was 50.3% and the unreacted monomer content was 0.02%.

Production Example 3 of Component (A) Production of Component (A-3) In a reaction vessel similar to that of Production Example 1, 718 parts of deionized water and 32 parts of a reactive emulsifier Latemul S-180A are placed. After charging and replacing the inside of the vessel with nitrogen gas, the vessel was heated to a temperature of 80 ° C. Then, 78 parts of styrene, 274 parts of 2-ethylhexyl acrylate, 431 parts of methyl methacrylate,
80 parts of a monomer mixture consisting of 16 parts of methacrylic acid and 1 part of 1,6-hexanediol diacrylate and 8 parts of a 5% aqueous potassium persulfate solution were charged into a reaction vessel, and stirring was continued for 1 hour while maintaining the temperature at 80 ° C. Was. Thereafter, volatile components other than water were sufficiently removed under reduced pressure.
The reaction was then heated to 80 ° C. and the remaining monomer mixture 7
20 parts and 24 parts of a 5% aqueous potassium persulfate solution were dropped into the reaction vessel at a constant rate over 4 hours.

During these operations, the temperature of the reaction vessel was raised to about 80
Stirring was continued while maintaining the temperature. After completion of the dropwise addition, stirring was continued for 1 hour while maintaining the reaction vessel at 80 ° C. Thereafter, 16 parts of a 5% aqueous potassium persulfate solution was added as an additional catalyst, and the mixture was stirred at 80 ° C. for 2 hours. Thereafter, the reaction vessel was cooled, 25 parts of a 10% aqueous sodium hydroxide solution was added, and the contents of the vessel were filtered through a 100-mesh wire net to obtain component (A) (A-3). The resin solid content was 50%, and the unreacted monomer content was 0.01%.

Examples 1 to 5 The components and mixing amounts shown in Table 1 were mixed and dispersed according to a conventional method to obtain the present composition. Further, 2 parts of a color paste (black) was blended with 100 parts of the composition to give a gray color.

[0029]

[Table 1]

Note 1) Product name manufactured by Rohm and Haas Inc. Note 2) Product name manufactured by Fuji Chemical Co., Ltd. Note 3) Product name manufactured by Asahi Denka Kogyo Co., Ltd. Note 4) Product name manufactured by Takeda Pharmaceutical Co., Ltd.

Comparative Example 1 An aqueous coating composition was prepared by removing the plasticizer (component B) from the composition of Example 1.

Comparative Example 2 A plasticizer was prepared by changing the plasticizer used in Example 1 to 3.0 parts of Texanol, which is conventionally used generally.

Comparative Example 3 As a conventional water-based paint, Vinylex 300 manufactured by Kansai Paint Co., Ltd. was used.

Table 2 shows the test results of the above Examples and Comparative Examples.
It was shown to. As is clear from these results, the water-dilutable coating material of the present invention has extremely low odor and excellent coating properties and film-forming properties.

The test methods used in the above Examples and Comparative Examples are as follows.

Odor (1): Each composition was 0.6 m in a test chamber (0.9 m width, 0.9 m depth and 1.2 m height) sealed with a polyester film.
× coating weight gypsum board of 0.6m is 130g / m ^2/1
Coating was performed twice with a roller so that the number of coatings became one. Painting temperature is 1
It is a result of qualitatively examining the degree of odor inside the test chamber 15 minutes after painting at 5 to 20 ° C. Specifically, the intensity of the odor was evaluated in three levels: weak, strong and intense. In addition, non-discomfort, discomfort and very discomfort were also assessed.

[0037] Odor (2): odor sensor indicated value, each composition Odor (1) coating the gypsum board in the chamber in the same manner as in (coating weight 200 g / m ^2/1 times), the generated odor This is a result measured by an odor sensor. An odor sensor XP-329 (trade name, manufactured by New Cosmos Electric, portable type) was used as the sensor, and the odor sensor indicated value before the measurement was started was adjusted to 100. Then, the odor in the test chamber was drawn and measured for 10 minutes. The indication value becomes high when there is much odor substance. The odor concentration was measured by a three-point comparative odor bag method.

Film forming property: In the state of being released on the above plaster board,
Each composition coating amount was coated twice by a roller so as to 130 g / m ^2/1 times to observe the presence or absence of crack in the coating film after drying for 24 hours at room temperature, it was evaluated as follows . Good: No cracking, inferior: Cracking is observed.

Coatability: Coat the entire surface in the same manner as in the film-forming property described above, and after drying at room temperature for 24 hours, apply a portion of the same with a brush (touch-up), and after drying for 24 hours, touch-up The difference in color development of the coating film between the part and the other part was examined and evaluated as follows. Good: no difference between the two parts, inferior: color difference is noticeable in both parts.

[0040]

[Table 2]

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Kazuo Nomoto 4-17-1, Higashi-Hachiman, Hiratsuka-shi, Kanagawa Pref. Kansai Paint Co., Ltd. (72) Inventor Yasuyoshi Tsuchida 74, Otana-cho, Kohoku-ku, Yokohama, Kanagawa Prefecture In Fujita (72) Inventor Yasuko Kumano 74 in Otana-cho, Kohoku-ku, Yokohama, Kanagawa Prefecture Fujita Incorporated (56) References JP-A-2-284964 (JP, A) JP-A-59-161405 (JP, A) JP-B-56-39393 (JP, B2) U.S. Pat. No. 4,545,402 (US, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) C09D 133/02 C09D 5/02 C09D 133/08

Claims (1)

(57) [Claims] (A) 2-ethylhexyl acrylate,
Alkyl methacrylate (C1-4) ester and (meth) acrylic acid are essential components, and if necessary,
Polymerized in styrene, n-butyl acrylate and one molecule
One or monomer component comprising using two or more selected from a vinyl monomer having sex two or more double bonds, Raj
An emulsion resin obtained by emulsion polymerization in the presence of an emulsifier having a cal (co) polymerizable carbon-carbon double bond and having an unreacted monomer content of 0.06% by weight or less; and (B) a dialkyl phthalate ( C6-10) Ester and 2,2,4-trimethyl 1,3-pentanediol
Alkyl (C2-6) 1 kind selected from esters or two or more plasticizers composed mainly low Nioigata water-dilutable coating composition Noisobuchireto.