JPH0153310B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to an emulsion coating composition that exhibits good thick coating properties and leveling properties on painted surfaces. In recent years, there has been a strong demand for non-polluting, safe and hygienic paints from the standpoint of environmental protection and health and safety, and the uses of emulsion paints are expanding, and applications for which solvent-based paints have traditionally been used, such as mastic bases, are expanding. Fields such as top coating of wood and top coating of metal are also attracting attention. However, emulsion paints mainly consist of vinyl acetate-based, acrylic-based, or acrylic-styrene-based vehicle particles dispersed in water. Since it is a dispersion type resin containing additives, preservatives, etc., it has thixotropic properties, and has problems such as poor coating ability and leveling properties on painted surfaces compared to solvent-based paints. As one method to solve these problems with emulsion paints, attempts have been made to use protective colloids such as hydroxyethyl cellulose, methyl cellulose, polyvinyl alcohol, etc. in the emulsion. In this method,
It is true that the coating properties and leveling properties are better than those using a colloid-free emulsion, but the use of a small amount of protective colloid does not provide a significant improvement. In addition, the use of a large amount of protective colloid is also important from the viewpoint of emulsion synthesis.
There are problems such as an increase in emulsion viscosity and gelation due to accelerated grafting, and even if an emulsion that can be made into a paint is obtained, the resulting emulsion paint has disadvantages such as poor water resistance and alkali resistance. be. Also, attempts have been made to change the thickener used in emulsion paints from conventional fiber derivatives to synthetic polymer thickeners. In this method, it is true that an emulsion paint with good leveling properties can be obtained, but there is a problem with the storage stability of the emulsion paint, and even if an emulsion paint with good storage stability is obtained, it is difficult to apply with a brush. However, it has the drawback that only a painted surface with poor thick coating properties and poor texture can be obtained. Furthermore, attempts have also been made to create emulsion paints by mixing emulsions with water-soluble resins. It is true that emulsion paints mixed with water-soluble resins provide painted surfaces with good fogging and leveling properties, but water-soluble resins are difficult to become water-soluble unless the acid value is increased, and emulsion paints mixed with this resin are The water resistance and alkali resistance of the coating film are poor,
Use is limited. Therefore, a water-soluble resin using an oxidation-hardened oil component is mixed with an emulsion,
Attempts have been made to improve the durability of the coating film, but there are problems with compatibility with synthetic resin emulsions, and there are also disadvantages in that they impair drying properties, which is an advantage of emulsion coatings. The present invention was completed as a result of intensive research into eliminating the above-mentioned drawbacks. That is,
According to the present invention, an emulsion coating composition comprising an emulsion coating and a specific water-soluble resin, more particularly, an alkyl ester of an α,β-monoethylenically unsaturated carboxylic acid and an alkenylbenzene in the presence of a water-soluble solvent. 70 to 99% by weight of at least one monomer selected from the following, 0.5 to 15% by weight of α,β-monoethylenically unsaturated carboxylic acid, and a hydrophilic nonionic α,β-monoethylenically unsaturated monomer. body
A water-soluble resin () obtained by polymerizing 0.5 to 15% by weight and then making it water-soluble with amine or ammonia is added to an emulsion paint () with a resin solid content of 100 parts by weight, and a resin solid content of 2 to 65 parts by weight. Provided is an emulsion coating composition with good thick coating properties and good leveling properties on a painted surface, which is characterized by containing the following: In addition, when creating the emulsion paint composition of the present invention, even if the emulsion paint () is added to the water-soluble resin (),
There is no problem. The emulsion paint used in the present invention is obtained by a conventional method and composition, and
For example, it refers to commercially available synthetic resin emulsions such as acrylic resins, acrylic-styrene resins, vinyl acetate resins, and the like. The above α used to produce the amine- or ammonia-neutralized water-soluble resin used in the present invention,
Examples of β-monoethylenically unsaturated carboxylic acid alkyl esters include esters of acrylic acid and alkanols having 1 to 18 carbon atoms, esters of methacrylic acid and alkanols having 1 to 18 carbon atoms, etc. Examples of the alkenylbenzene include styrene, vinyltoluene, α-methylstyrene, and the like. Examples of α,β-monoethylenically unsaturated carboxylic acids include acrylic acid, methacrylic acid, crotonic acid,
Examples include itaconic acid, maleic acid, fumaric acid, and the like. Hydrophilic nonionic α,β-monoethylenically unsaturated monomers include acrylate or methacrylate of methoxypolyethylene glycol, acrylate or methacrylate of polyethylene glycol, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 2-
Hydroxyalkyl esters of α,β-monoethylenic carboxylic acids such as hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, acrylamide, methacrylamide, methylolated products and alkyl etherified products thereof, N,N-dimethylaminoethyl acrylate, Examples include N,N-dimethylaminoethyl methacrylate, and methoxypolyethylene glycol acrylate or methacrylate, and polyethylene glycol acrylate or methacrylate are particularly preferred. The water-soluble resin used in the present invention includes at least one monomer selected from α,β-monoethylenically unsaturated carboxylic acid alkyl ester and alkenylbenzene, α,β-monoethylenically unsaturated carboxylic acid, and a hydrophilic The three essential components are nonionic α,β-monoethylenically unsaturated monomers. At least one monomer selected from α-β-monoethylenically unsaturated carboxylic acid alkyl esters and alkenylbenzenes is effective for compatibility with the emulsion paint and durability of the paint film. The combination of α,β-monoethylenically unsaturated carboxylic acid and hydrophilic nonionic α,β-monoethylenically unsaturated monomer is important for its compatibility with emulsion paints and the thick coating properties of the resulting paints. Involved in leveling and durability. In conventional emulsion coating compositions containing water-soluble resins, in order to make water-soluble resins that are sufficiently water-soluble and have good compatibility with emulsion coatings, it is necessary to add α,β-monomers. A large amount of ethylenically unsaturated carboxylic acid is required, and in this case, the durability of the coating film of the prepared emulsion paint becomes extremely poor, and the field of use is extremely limited. In contrast, in the present invention, by adding a hydrophilic nonionic α,β-monoethylenically unsaturated monomer to make the three components, α,β - Not only was it possible to suppress the deterioration of the paint film by reducing the amount of monoethylenically unsaturated carboxylic acid used, but it was also possible to obtain, for the first time, a paint composition with significantly improved thick coating and leveling properties. be. This effect is unexpected from the properties of conventional emulsion coating compositions containing water-soluble resins, and is a synergistic effect achieved by creating a three-component water-soluble resin. Thus, the water-soluble resin used in the present invention requires the above-mentioned three components, and if even one of these components is missing, the object of the present invention cannot be achieved. α,β-monoethylenically unsaturated carboxylic acid is
0.5-15% by weight, preferably 1-10% by weight are used. If the amount is less than 0.5% by weight, the compatibility between the emulsion paint and the water-soluble resin will be poor, and the emulsion paint created will undergo phase separation.
If the amount exceeds the amount, the durability of the coating film will be affected, especially on base materials containing alkaline substances such as slate boards and flexible boards, which will be affected by the material and will cause deterioration of the coating film. The hydrophilic nonionic α,β-monoethylenically unsaturated monomer is present in an amount of 0.5 to 15% by weight, preferably 1 to 10% by weight.
Weight percentages are used. If it is less than 0.5% by weight, it will not be effective in reducing the amount of acid group monomer used and improving thick coating properties and leveling properties, and if it is more than 15% by weight, the durability of the coating film will deteriorate. The proportion of the water-soluble resin component in the present invention is based on 100 parts by weight of the resin solid content of the emulsion paint.
The resin solid content is 2 to 65 parts by weight, preferably 4 to 40 parts by weight, and only when used within this range can an emulsion coating composition with good thick coating and leveling properties be obtained. If it deviates from this range, there is a risk that the durability of the paint film will be significantly impaired and it will no longer be able to be used as a paint, or that it will not work effectively in significantly improving thick coating properties and leveling properties, making it difficult to expect the effects of the present invention. I won't be able to do that. Examples of water-soluble solvents include cellosolve solvents such as ethyl cellosolve and butyl cellosolve, carbitol solvents such as carbitol and butyl carbitol, cellosolve acetate solvents such as diethylene glycol dimethyl ether, and alcohol solvents such as isopropyl alcohol. etc. can be used as appropriate. The emulsion coating composition of the present invention can be applied to slate boards, stone, paper, metal, etc. by brushing, spraying, roller coating, etc., but it has better thick coating and leveling properties than conventional emulsion coatings. It is particularly excellent in that it can be applied to top coats of mastic base materials, metal top coats, etc., for which solvent-based paints have traditionally been used, as the coated surface condition has been significantly improved. Next, the present invention will be specifically explained based on examples. In the following, parts and percentages are by weight. Example 1 (1) Production of emulsion paint Polymerization was carried out in a conventional manner using the following formulation. Deionized water 105 parts Methyl methacrylate 58 parts 2-ethylhexyl acrylate 40 parts Acrylic acid 2 parts Polyoxyethylene glycol nonyl phenyl ether 5 parts Potassium persulfate 0.5 parts After the polymerization reaction, add a small amount of ammonia to adjust the pH.
Adjusted to 8.0. This emulsion paint had a non-volatile content of 50% and a viscosity of 200 centipoise. (2) Production of water-soluble resin Charge 90 parts of ethyl cellosolve into a flask equipped with a reflux condenser, stirrer, thermometer, dropping funnel, and inert gas inlet. The flask temperature was heated to 80°C, and a mixed monomer consisting of 40 parts of butyl acrylate, 49 parts of methyl methacrylate, 3 parts of styrene, 6 parts of acrylic acid, and 2 parts of methoxypolyethylene glycol methacrylate (9 moles of ethylene glycol added) and perbutyl-O were added. A solution of 10 parts of ethyl cellosolve in which 1 part of t-butyl peroxyoctoate (manufactured by NOF) was dissolved was separately added dropwise over 4 hours. After the reaction was completed, 5 parts of aqueous ammonia (28%) and water were added to obtain a water-soluble resin. The obtained water-soluble resin has a solid content of 30%, and its pH is 9.0.
The viscosity was 1000 cps. (3) An emulsion coating composition was produced with the following formulation. Titanium oxide (Tiepeke R-630, manufactured by Ishihara Sangyo)
25 parts ethylene glycol 5 parts Emulsion paint obtained in (1) (50% solids) 43 parts Water-soluble resin obtained in (2) (30% solids) 8 parts Distilled water 5 parts Pigment, ethylene glycol, water-soluble The resin and distilled water were placed in a porcelain ball mill to disperse the pigment, and then the emulsion was added to the pigment dispersion and mixed by thorough stirring. Example 2 (1) A water-soluble resin was produced using the same method as shown in Example 1 using the following formulation. The obtained water-soluble resin has a solid content of 30%, a pH of 9.0, and a viscosity of
It was 1100cps. Butyl acrylate 40 parts Methyl methacrylate 49 parts Styrene 3 parts Acrylic acid 6 parts Polyethylene glycol methacrylate (EG9
molar addition) 2 parts perbutyl-O 1 part (2) An emulsion coating composition was prepared with the following formulation:
It was manufactured using the same method as in Example 1. Coordination titanium (Tiepeque R-630) 25 parts Ethylene glycol 5 parts Emulsion paint obtained in Example 1 (1) 43 parts Above water-soluble resin 8 parts Distilled water 5 parts Example 3 (1) With the following formulation A water-soluble resin was produced by the same method as shown in Example 1. The resulting water-soluble resin has a solid content of 30%, a pH of 9.0, and a viscosity of
It was 1500cps. Butyl acrylate 40 parts Methyl methacrylate 49 parts Styrene 3 parts Acrylic acid 4 parts N-methylolacrylamide 4 parts Perbutyl-O 1 part (2) An emulsion coating composition was prepared using the following formulation.
It was manufactured using the same method as in Example 1. Titanium oxide (Tiepeque R-630) 25 parts Ethylene glycol 5 parts VONCOAT EC-818 (acrylic resin emulsion manufactured by Dainippon Ink Chemical Co., Ltd.) (solid content 50%)
43 parts of the above water-soluble resin 8 parts Distilled water 5 parts Comparative Example 1 (1) A water-soluble resin was produced in the same manner as shown in Example 1 using the following formulation. The resulting water-soluble resin has a solid content of 30%, a pH of 9.0, and a viscosity of
It was 3000cps. Butyl acrylate 40 parts Methyl methacrylate 49 parts Styrene 3 parts Acrylic acid 8 parts Perbutyl-O 1 part (2) An emulsion coating composition was prepared using the following formulation.
It was manufactured using the same method as in Example 1. Titanium oxide 25 parts Ethylene glycol 5 parts Emulsion paint obtained in Example 1 43 parts Above-mentioned water-soluble resin 8 parts Distilled water 5 parts Comparative Example 2 (1) By the same method as shown in Example 1 with the following formulation, A water-soluble resin was produced. The resulting water-soluble resin has a solid content of 30%, a pH of 9.0, and a viscosity of
It was 1100cps. Butyl acrylate 40 parts Methyl methacrylate 47 parts Styrene 3 parts Methoxypolyethylene glycol methacrylate (9 moles of EG added) 10 parts Perbutyl-O 1 part (2) An emulsion coating composition was prepared as follows:
It was manufactured using the same method as in Example 1. Titanium oxide (Tiepeke R-630) 25 parts Ethylene glycol 5 parts Emulsion paint obtained in Example 1 43 parts Above water-soluble resin 8 parts Distilled water 5 parts Comparative example 3 (1) Emulsion paint obtained in Example 1 An emulsion coating composition was produced in the same manner as in Example 1 using the following formulation and water-soluble resin. Titanium oxide 25 parts Ethylene glycol 5 parts Emulsion paint obtained in Example 1 (solid content 50
%) 24 parts Water-soluble resin obtained in Example 1 (solid content 30%) 28 parts Distilled water 5 parts Comparative Example 4 (1) Using the emulsion paint and water-soluble resin obtained in Example 1, emulsion paint was prepared. A composition was manufactured with the following formulation. () Titanium oxide 25 parts () Ethylene glycol 5 parts () Alcohol-based coating aids (Texanol,
2.5 parts (manufactured by Kodatsu) Sodium polyacrylate dispersant (Tamol 731 (25%), manufactured by Rohm and Haas)
1 part () Emulsion paint obtained in Example 1
50 parts () 1 part of the water-soluble resin obtained in Example 1 After sufficiently dispersing the above () to () in a colloid mill, () and () were added and mixed by uniform stirring. Test Example The emulsion coating compositions obtained in Examples 1 to 3 and Comparative Examples 1 to 4 were diluted with water to 70 KU, applied twice with a brush to a slate board, dried for one day at room temperature, and then coated with a paint film. I conducted a test. The test method was as follows. Thick coating property (coating amount): After diluting the emulsion paint composition with water to 70 KU, it was applied twice with a brush to a 250 x 150 mm slate board, and the weight of the paint adhered to the slate board was measured. Thick coating property (visual observation): Visually observe the degree of coverage of the magick (black) when the above emulsion paint composition is applied with a brush two times on a 250 x 150 mm slate board that has been marked with a magick (black) in advance. did.
The results were expressed as 〇 (good) > △ (fair) > × (poor). Leveling property: 250x emulsion paint composition
It was applied twice with a brush to a 150 mm slate board, and after drying for one day at room temperature, the brush marks on the coated surface were visually observed. The results are 〇(good)＞△(fair)＞×
Displayed as (defective). Water resistance: The emulsion paint composition was applied twice with a brush to a 150 x 50 mm slate board, dried for one day at room temperature, then immersed in room temperature water for 14 days, and the presence or absence of abnormalities occurring in the coating film was observed. . Alkali resistance: 5% of the specimen made in the same way
The coating film was immersed in a NaOH aqueous solution for 14 days, and the presence or absence of abnormalities occurring in the coating film was observed. Outdoor background properties: 250x emulsion paint composition
I applied it twice with a brush to a 150mm slate board, let it dry for a day at room temperature, then exposed it outdoors for 6 months.
The presence or absence of abnormalities occurring in the paint film was observed. The test results are shown in the table below. These results show that the emulsion coating composition of the present invention has excellent fogging, leveling properties, and durability.

【table】

【table】

Claims (1)

[Claims] 1 At least one monomer selected from α,β-monoethylenically unsaturated carboxylic acid alkyl ester and alkenylbenzene is added to 100 parts by weight of the emulsion paint (as resin solid content) in the presence of a water-soluble solvent. 99% by weight, 0.5-15% by weight of α,β-monoethylenically unsaturated carboxylic acid and 0.5-15% by weight of hydrophilic nonionic α,β-monoethylenically unsaturated monomer, followed by amine Or water-soluble resin made water-soluble with ammonia ()
An emulsion coating composition having good thick coating properties and leveling properties, characterized in that it contains 2 to 65 parts by weight of solid resin.