JP3204462B2 - Manufacturing method of resin for matte paint - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention does not contain a matting agent
The present invention relates to a method for producing a matting coating resin by a specific polymerization method.

[0002]

2. Description of the Related Art A matting paint is made by adding a matting agent, for example, fine powder silica, polyethylene fine powder, or the like to a paint to generate microscopic irregularities on the surface of the coating film and to reduce gloss by irregular reflection of light. Things. However, in such a treatment method, there is a disadvantage that the matting agent is apt to have an adverse effect, for example, when the coating film is rubbed, the portion becomes glossy and the appearance becomes unbalanced.

[0003]

Therefore, if a practical matte paint can be produced without using such a matting agent, it can be said that its industrial utility is extremely large. An object of the present invention is to obtain a practical matte paint without blending a matting agent.

[0004]

According to the present invention, a matte is provided.
A matting coating resin containing no shampoo, wherein (a) alkyl (meth) acrylate having 1 to 4 carbon atoms in the alkyl group is 20 to 80% by weight, and (b) styrene compound is 10 to 50% by weight. % By weight (c) In the production of a resin having a ratio of 10 to 30% by weight of an alkyl (meth) acrylate having an alkyl group having 5 or more carbon atoms, when the polymerization rate of (a) reaches 80% or more By adding (b) and (c) in the above and further promoting the polymerization, the above object can be achieved, and a resin useful as a matte coating resin can be obtained.

In the constituents of the resin, the alkyl (meth) acrylate having an alkyl group of (a) having 1 to 4 carbon atoms is 20 to 80% by weight, preferably 30 to 70% by weight. If it is less than 20% by weight, the matting effect is insufficient, and if it is more than 80% by weight, the resin solution undergoes layer separation. The styrene compound of (b) is 10 to 50% by weight, preferably 20 to 40% by weight. If it is less than 10% by weight, the matting effect is insufficient, and if it exceeds 50% by weight , the weather resistance becomes poor. The alkyl group (c) having 5 or more carbon atoms in the alkyl group is 10 to 30% by weight, preferably 15 to 25% by weight. If it is less than 10% by weight, the matting effect becomes insufficient, while if it is more than 30% by weight, the matting effect becomes insufficient.

[0006] In producing the resin of the present invention, solution polymerization using an organic solvent is usually carried out. First, a predetermined amount of (a) is dissolved in an organic solvent, and the polymerization of (a) is carried out using a radical polymerization catalyst. When the polymerization rate of (a) reaches 80% or more, (b) is added to the system. And (c) are added, and the polymerization is further advanced to obtain a target resin solution. The polymerization rate is measured as a percentage of the heating residue and the theoretical heating residue in the sample of the resin solution during the polymerization. When the polymerization rate is less than 80%, (b) and (c) are added and the polymerization is further advanced, the matting effect is insufficient, and
If (c) or (b) is added after previously polymerizing (a) and (b) or (a) and (c), the coating film tends to be stained, which is not preferable.

The alkyl (meth) acrylate having 1 to 4 carbon atoms in the alkyl group (a) includes methyl (meth) acrylate, ethyl (meth) acrylate and (meth) acrylate.
Propyl acrylate, isopropyl (meth) acrylate, butyl (meth) acrylate, isobutyl (meth) acrylate, sec-butyl (meth) acrylate, (meth)
T-butyl acrylate; and the like, alone or in combination of two or more. Examples of the styrene compound (b) include styrene and vinyl toluene. Examples of the alkyl (meth) acrylate having 5 or more carbon atoms in the alkyl group (c) include amyl (meth) acrylate, hexyl (meth) acrylate, heptyl (meth) acrylate, and octyl (meth) acrylate. , 2-ethylhexyl (meth) acrylate, decyl (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate and the like, alone or in combination of two or more.

[0008] If necessary, other monomers such as hydroxyl-containing alkyl (meth) acrylates such as 2-hydroxyethyl (meth) acrylate and 2-hydroxypropyl (meth) acrylate, and polymerizable polymers such as (meth) acrylamide. Vinyl compounds such as amide, vinyl acetate and vinyl propionate; unsaturated carboxylic acids such as (meth) acrylic acid, crotonic acid, itaconic acid, (maleic anhydride) and fumaric acid; dimethylaminoethyl acrylate, diethylaminoethyl methacrylate Basic monomers can also be used in small amounts.

The coating resin of the present invention is preferably produced by a solution polymerization method using an organic solvent, as described above. Examples of the organic solvent include aromatic hydrocarbons such as toluene and xylene. Esters such as ethyl acetate and butyl acetate; ketones such as methyl ethyl ketone and methyl isobutyl ketone; aliphatic alcohols such as isopropyl alcohol and n-butanol; ethylene glycol monomethyl ether; ethylene glycol monoethyl ether; and the like, used alone or in combination. . As the polymerization catalyst, known radical polymerization catalysts such as azobisisobutyronitrile, benzoyl peroxide, di-tert-butyl peroxide, cumene hydroperoxide and the like are used. Temperature during polymerization is 60-150 ° C
And the polymerization time is practically about 6 to 20 hours.

[0010] The coating resin of the present invention can be put to practical use as a coating resin in the state where the organic solvent used at the time of polymerization is used as it is as described above. It can be used by replacing. Examples of the pigment used when preparing a paint using the paint resin of the present invention include titanium oxide, calcium carbonate, talc, lithobon, barium sulfate, calcium sulfate, alumina, white pigments such as clay, carbon black, and iron black. Blue pigments such as black pigments, phthalocyanine blue, navy blue, ultramarine, etc.
Yellow pigments such as lake yellow, yellow lead, Oka yellow, and Hansa yellow; red pigments such as red bengara and lake red; orange pigments such as chrome vermillion; green pigments such as phthalocyanine green and chromium oxide.
In addition, if necessary, a plasticizer, an anti-sagging agent, an anti-settling agent, an antifoaming agent and the like are appropriately compounded.

For the preparation of the paint, a commonly used sand mill, disperser, ball mill or the like is used. As a method of applying the obtained paint, methods such as ironing, brushing, roller coating, and spraying are employed. When this paint is used as a top coat paint for exterior materials such as concrete, mortar buildings, tiles, and sideboards, and further used as a paint for interiors and floors of buildings, a painted surface with a calm finish can be obtained.

[0012]

In the present invention, a practical matte paint can be produced without using a matting agent by polymerizing the components (a), (b) and (c) in two stages. I can do it.

[0013]

Next, the present invention will be described in more detail by way of examples. Example 1 In a 4-liter four-necked flask equipped with a stirrer, a thermometer, and a condenser, 715 parts of methyl methacrylate, 320 parts of toluene, and 1.5 parts of benzoyl peroxide were charged, and polymerization was started at a temperature of 90 ° C. Benzoyl peroxide was added on the way, and the polymerization rate was 90
%, And 325 parts of styrene and 260 parts of 2-ethylhexyl acrylate were gradually charged. After continuing the reaction for another 4 hours, toluene was added and the mixture was cooled, and a resin solution (A-A) having a solid content of 45% and a viscosity of 3000 cps / 25 ° C.
1) was obtained. The composition of (A-1) is methyl methacrylate 5
It was 5% by weight, 25% by weight of styrene, and 20% by weight of 2-ethylhexyl acrylate.

Preparation of Coating and Measurement of Appearance of Coating Film For 30 parts of the resin solution, 40 parts of titanium oxide and 10 parts of glass beads were used.
0 parts were placed in a 250 ml glass bottle, shaken and dispersed with a paint conditioner for 30 minutes, and then 60 parts of the same resin solution was further added, and shaken with a paint conditioner for 10 minutes to obtain a white paint. Obtained white paint 1
Toluene / xylene (= 1/1) thinner 4 in 00 parts
After adding and diluting 0 parts, the mixture was applied to a tin plate with a bar coater # 50 and dried, and then a 60-degree specular reflection gloss was measured with a gloss meter. Next, a line having a width of 2 mm was drawn one by one with red and black oil-based magic on the coating surface of the tin plate coated with the white paint and dried, and after 24 hours, wiped with cotton containing ethanol to contaminate the surface. The properties were measured. The results are shown in Table 1.

Examples 2 to 8 Resins shown in Tables 1 and 2 were produced according to Example 1. The results are shown in Tables 1 and 2.

[0016]

[Table 1]

[0017]

[Table 2]

Control Example 1 In the same flask as in Example 1, 325 parts of styrene, 260 parts of 2-ethylhexyl acrylate, 320 parts of toluene,
1.5 parts of benzoyl peroxide was charged at a temperature of 90.
The polymerization was started at ℃, benzoyl peroxide was added in the middle, and after the polymerization rate reached 90% in 6 hours from the start of polymerization, 715 parts of methyl methacrylate was gradually charged. After continuing the reaction for another 4 hours, toluene was added and cooled,
A resin solution (B-1) having a solid content of 45% and a viscosity of 4000 cps / 25 ° C. was obtained. The composition of (B-1) is styrene 25
% By weight, 20% by weight of 2-ethylhexyl acrylate,
It was 55% by weight. The gloss was 35 and the stain resistance was poor.

Comparative Example 2 325 parts of styrene, 260 parts of 2-ethylhexyl acrylate, 715 parts of methyl methacrylate, 520 parts of toluene and 520 parts of benzoyl peroxide were placed in a 4-liter four-necked flask equipped with a stirrer, a thermometer and a condenser. Two parts were charged, and polymerization was started at a temperature of 90 ° C. Benzoyl peroxide was added on the way, polymerization was continued, and after reacting for 9 hours, toluene was added and cooled to obtain a resin solution (B-2) having a solid content of 45% and a viscosity of 3300 cps / 25 ° C.
The composition of (B-2) was the same as (B-1). The gloss was 75 and the stain resistance was poor.

[0020]

According to the present invention, by adopting a specific polymerization method, a resin useful as a matting paint can be produced by using the resin alone without using a matting agent.

Claims (1)

(57) [Claims] 1. A matting paint resin containing no matting agent.
A is, (a) (meth) acrylic acid alkyl ester having a carbon number of 1 to 4 alkyl groups from 20 to 80 wt% (b) a styrene compound is 10 to 50 wt% (c) the number of carbon atoms in the alkyl group In producing a matte coating resin having a ratio of 10 to 30% by weight of a (meth) acrylic acid alkyl ester having 5 or more, first, (a) is polymerized, and after the polymerization rate becomes 80% or more ( A process for producing a matte coating resin, which further comprises polymerizing b) and (c).