JP3204468B2 - 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,
Acrylic that does not use styrene monomer as a copolymer component
TECHNICAL FIELD The present invention relates to a method for producing a matte coating resin by a specific polymerization method.

[0002]

2. Description of the Related Art A matting paint is prepared by adding a matting agent, for example, fine powder silica, polyethylene fine powder, etc. to the paint to generate micro unevenness on the coating film surface and to reduce the gloss by irregular reflection of light. Things. However, in such a treatment method, there is a disadvantage that the matting agent is likely to have an adverse effect, for example, when the coating film is rubbed, the portion becomes glossy and the appearance becomes unbalanced. In order to solve such a drawback, the present applicant has previously filed an application for a method for producing a matte coating resin using a special polymerization method (Japanese Patent Application Laid-Open No. 3-81371 and Japanese Patent Application No. 4-109001). This means that a copolymer of a styrene monomer and an alkyl (meth) acrylate having 5 or more carbon atoms in the alkyl group and an alkyl (meth) acrylate having 1 to 4 carbon atoms in the alkyl group are used.
This is to produce a matte coating resin by step polymerization.

[0003]

However, although the resin produced by such a production method can sufficiently be put to practical use, it has a problem in weather resistance because a styrene monomer is contained in the compounded composition. For outdoor use, the possibility of yellowing due to ultraviolet light is very large and there is room for improvement.

[0004]

Means for Solving the Problems Accordingly, the present inventors have
In order to solve this problem, as a result of diligent research on a formulation that does not use a styrene monomer as a copolymer component, the formulation does not contain a matting agent and contains a styrene monomer.
Acrylic matte coating resin that is not used as a polymerization component.
Te, (a) (meth) acrylic acid alkyl ester having a carbon number of 1 to 4 alkyl groups, (b) the number (a) Unlike carbon atoms in the alkyl group having 1 to 4 carbon (meth) acrylic acid Alkyl ester and (c) alkyl group having 5 carbon atoms
Consisting of the above alkyl (meth) acrylate,
It is a resin in which the content of (a) and (b) is 20 to 90% by weight and the content of (c) is 80 to 10% by weight. polymerizing a) and then polymerizing (b) and (c) in the second stage,
In the first stage, (a) and (c) are polymerized, and then in the second stage, (b) is polymerized.
In the case described above, it has been found that the weather resistance (yellowing) of the matte coating resin can be significantly improved, and the present invention has been completed.

A feature of the present invention is that, as described above, instead of not using a styrene monomer, two different alkyl groups having 1 to 4 carbon atoms (alkyl) (meth) acrylate and an alkyl group having 5 or more carbon atoms are used. In that two-stage polymerization is performed using the three components of the alkyl (meth) acrylate. This makes it possible to produce a matte coating resin having good weather resistance.

Hereinafter, the present invention will be described in detail. The alkyl groups (a) and (b) used in the present invention have 1 to 1 carbon atoms.
(4) alkyl (meth) acrylate means methyl (meth) acrylate, ethyl (meth) acrylate,
Propyl (meth) acrylate, isopropyl (meth) acrylate, butyl (meth) acrylate, isobutyl (meth) acrylate, sec-butyl (meth) acrylate,
T-butyl (meth) acrylate and the like can be mentioned, and two or more kinds are used in combination.

It is particularly preferable to use methyl (meth) acrylate as the component (a) or (b) from the viewpoint of matting effect. Further, (c) alkyl (meth) acrylates having 5 or more carbon atoms in the alkyl group include amyl (meth) acrylate, hexyl (meth) acrylate, heptyl (meth) acrylate, and (meth) acrylic acid. Octyl acid, 2-ethylhexyl (meth) acrylate, decyl (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate and the like are used alone or in combination of two or more.

[0008] In the above components constituting the matte coating resin of the present invention, the content of (a) and (b) is 20 to 90% by weight, preferably 30 to 80% by weight. 20% by weight
If it is less than 90%, the matting effect becomes insufficient, and if it exceeds 90% by weight, the resin solution undergoes layer separation. The content of (c) is 8
It is 0 to 10% by weight, preferably 70 to 15% by weight.
If the content is less than 10% by weight, the resin solution is in a layer separation state,
If the amount is more than 10% by weight, the matting effect becomes insufficient.

In producing the resin of the present invention, solution polymerization using an organic solvent is usually carried out. First, a predetermined amount of (a) or (a) and (c) is dissolved in an organic solvent,
(A) or about 0.3 to 3.5% by weight based on the total weight of (a) and (a) and (c),
Or the copolymerization of (a) and (c) (first stage). After the polymerization rate of the polymerization reaches 70% or more, (b) and (c) or (b) are added as a second stage, and at the same time, a polymerization catalyst is added in the same manner as described above, and the polymerization (2)
Step 2) to obtain the target resin solution. The polymerization rate is
During the polymerization, the resin solution is sampled and measured as a percentage of the heating residue and the theoretical heating residue in the sample.

In the above polymerization, if the polymerization rate of the first stage (a) or (a) and (c) is less than 70%, the matting effect is insufficient and the resin solution undergoes layer separation, The object of the present invention cannot be achieved.

In the present invention, the above (a) and (b)
Other monomers besides (c) and (c) may be used as needed. As an example, (meth) acrylic acid 2-
Hydroxyl group-containing alkyl (meth) acrylates such as hydroxyethyl and 2-hydroxypropyl (meth) acrylate, polymerizable amides such as (meth) acrylamide, vinyl compounds such as vinyl acetate and vinyl propionate, and (meth) acrylic acid , Crotonic acid, itaconic acid,
(Anhydride) unsaturated carboxylic acids such as maleic acid and fumaric acid; and basic monomers such as dimethylaminoethyl acrylate and diethylaminoethyl methacrylate.

As described above, the coating resin of the present invention is preferably produced by a solution polymerization method using an organic solvent. As the organic solvent, aromatic hydrocarbons such as toluene and xylene; Ester such as ethyl acetate and butyl acetate; ketone such as methyl ethyl ketone and methyl isobutyl ketone; aliphatic alcohol such as isopropyl alcohol and n-butanol; ethylene glycol monomethyl ether; ethylene glycol monoethyl ether; Used together.

As the polymerization catalyst, known radical polymerization catalysts such as azobisisobutyronitrile, benzoyl peroxide, di-tert-butyl peroxide, cumene hydroperoxide and the like are used.
The temperature during the polymerization is suitably from 60 to 150 ° C, and the polymerization time is practically from about 2 to 15 hours. The polymerization time of the first stage at this time varies depending on the amount of the catalyst added, the types of the components (a) and (c), and the mixing ratio thereof.
It is about an hour. The coating resin of the present invention, in the state where the organic solvent used at the time of polymerization as the solvent as it is,
It is practically used as a paint resin, but if necessary,
It can be used by replacing it with any solvent.

Examples of the pigment used when preparing a coating using the coating resin of the present invention include white pigments such as titanium oxide, calcium carbonate, talc, lithobon, barium sulfate, calcium sulfate, alumina and clay, and carbon black. , Black pigments such as iron black, phthalocyanine blue, navy blue,
Blue pigments such as ultramarine blue, yellow pigments such as lake yellow, graphite, Oka yellow and Hansa yellow, red pigments such as red bengala and lake red, orange pigments such as chrome vermillion, and green pigments such as phthalocyanine green and chromium oxide. No. 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. This paint can be used as a top coating for exterior materials such as concrete, mortar buildings, roof tiles, and sideboards, and can also be used as a paint for building interiors and floors. Can be used as matte paint.

[0016]

In the present invention, instead of using no styrene monomer, two different alkyl groups (meth) acrylic acid alkyl esters having 1 to 4 carbon atoms and a (meth) acrylic acid having 5 or more carbon atoms in the alkyl group are used. Since the two-stage polymerization is carried out using three components of the acid alkyl ester, a resin for matte paint having excellent weather resistance can be obtained.

[0017]

Next, the present invention will be described in more detail by way of examples. In the examples, “%” and “parts” mean “weight basis” unless otherwise specified. Example 1 A four-necked flask equipped with a stirrer, a thermometer, and a condenser was charged with 550 parts of methyl methacrylate and 250 parts of toluene. The mixture was heated until the internal temperature reached 90 ° C., and 6 parts of benzoyl peroxide was added. Then, the first-stage polymerization was started. 1.5 hours after the start of the polymerization, the conversion reached 95%, so that 2-ethylhexyl acrylate 2 was used as the second stage.
Then, 5 parts of benzoyl peroxide was added, and the reaction was continued for another 2 hours. Then, toluene was added and cooled, and the solid content was 50% and the viscosity was 4000 cps / 25 ° C. A resin solution (A-1) was obtained. The resin composition of (A-1) was 55% methyl methacrylate, 25% ethyl methacrylate, and 20% 2-ethylhexyl acrylate. After applying and drying the resin solution (A-1) on a glass plate using a bar coater # 60, the gloss value was 12 as measured with a gloss meter at 60 ° specular reflection gloss. In addition, the resin solution (A-
A paint is prepared by adding titanium oxide, a diluting solvent, etc. to 1), and irradiating for 3000 hours in accordance with the accelerated weathering test specified in JIS K 5400, and measuring the degree of yellowing of the coating film surface with a color difference meter (measurement). Was measured by using an instrument). The color tone before irradiation was set to blank before irradiation, and the color difference (ΔE) after irradiation was expressed by the Lab method.

Examples 2 to 4 Using the components (a), (b) and (c) shown in Table 1, resin solutions (A-2 to 4) were obtained in the same manner as in Example 1; , Gloss value and color difference were measured. Example 5 A four-necked flask equipped with a stirrer, a thermometer, and a condenser was charged with 270 parts of ethyl methacrylate, 180 parts of 2-ethylhexyl acrylate, and 300 parts of toluene, and heated until the internal temperature reached 90 ° C. Then, 5 parts of benzoyl peroxide was added, and the first-stage polymerization was started. Polymerization rate is 8
0%, so the second stage was methyl methacrylate 5
Charge 50 parts and add 4 parts of benzoyl peroxide.
After 2 hours, 5 parts of the same catalyst were additionally charged. After continuing the reaction for another 2 hours, toluene was added and the mixture was cooled to obtain a resin solution (A-5) having a solid content of 50% and a viscosity of 2000 cps / 25 ° C. The resin composition of (A-5) was 55% methyl methacrylate, 27% ethyl methacrylate,
18% 2-ethylhexyl acrylate. The gloss value and the color difference of this resin solution (A-5) were measured in the same manner as in Example 1. The gloss value was 10, and the color difference (ΔE) was 10.
Was 3.4.

Examples 6 to 8 Using the components (a), (b) and (c) shown in Table 1, resin solutions (A-6 to 8) were obtained in the same manner as in Example 5, and the viscosity was similarly measured. , Gloss value and color difference were measured. Comparative Example 1 Resin solution (B-1) was obtained by performing the same reaction as in Example 1 except that the polymerization rate in the first stage was changed to 60% in Example 1.
I got The viscosity, gloss value and color difference were measured in the same manner as in Example 1.

Comparative Examples 2 to 11 Using the components (a), (b) and (c) shown in Table 2, resin solutions (B-2) were prepared according to Comparative Examples 2 to 5 in accordance with Examples 1 and 5. To 5), and the viscosity, gloss value and color difference were measured in the same manner. In Comparative Example 4, only the two components shown in Table 2 were polymerized, and in Comparative Example 5, only the component (c) was polymerized in the first stage. The viscosities, gloss values and color differences of the resin solutions obtained from the examples and comparative examples are shown in Tables 3 and 4, respectively.

[0021]

[Table 1] First stage Second stage First stage Polymerization rate (a) (c) (b) (c) (%) Amount (%) Amount (%) Amount (%) Amount (%) Example 1 MMA EMA 2EHA 95 55 25 20 〃 2 MMA i-BMA 2EHA 90 30 49 21 〃 3 n-BMA MMA 2EHA 95 55 20 25 〃 4 EMA MMA LA 75 20 30 50 〃 5 EMA 2EHA MMA 80 27 18 55 〃 6 MMA 2EHA EA 90 45 15 40 ７ 7 MMA 2EHA i-PMA 90 40 30 30 ８ 8 EMA LA MMA 80 25 15 60 Note) MMA; methyl methacrylate, EMA; ethyl methacrylate, 2EHA; 2-ethylhexyl acrylate, i-BMA; methacrylic acid Isobutyl, n-BMA; n-butyl methacrylate, LA; lauryl acrylate, EA; Ethyl acrylate, i-PMA; isopropyl methacrylate

[0022]

[Table 2] (Abbreviations are the same as in Table 1.) 1st stage 2nd stage 1st stage polymerization rate (a) (c) (b) (c) (%) Amount (%) Amount (%) Amount (%) ) weight (%) Comparative example 1 MMA EMA 2EHA 60 55 25 20 〃 2 MMA EMA 2EHA 80 55 40 5 〃 3 MMA EMA 2EHA 80 5 5 90 〃 4 MMA 2EHA 90 55 45 〃 5 2EHA EMA 2EHA 80 55 40 5

[0023]

[Table 3] Viscosity * Mitsuzawa value Color difference (ΔE) Resin solution (cps / 25 ° C) (%) (A-1) 4000 12 3.5 (A-2) 4000 10 2.8 (A-3) 3000 3 2 2.8 (A-4) 2500 5 3.0 (A-5) 2000 10 3.4 (A-6) 5000 12 3.0 (A-7) 4000 10 2.8 (A-8) 2500 8 3 * 6 ) * Viscosity is a value measured with a B-type viscometer of a toluene solution having a solid content of 50%.

[0024]

[Table 4] Viscosity * Mitsuzawa value Color difference (EΔ) Resin solution (cps / 25 ° C) (%) (B-1) 100,000 <75 3.6 (B-2) ** 20 3.4 (B-3) 4500 60 4.2 (B-4) ** 25 3.7 (B-5) ** 30 Large surface tackiness and large amount of deposits can not be measured. Note) * Viscosity is B type of toluene solution with 50% solids concentration. Measured value by viscometer. ** Not measured because resin solution caused layer separation.

[0025]

According to the present invention, a specific alkyl acrylate is combined as a monomer to be copolymerized,
In addition, by employing a specific polymerization method, it is possible to produce a resin which is useful alone as a matting paint and has excellent weather resistance without using a matting agent.

Claims (1)

(57) [Claims] 1. A styrene-based resin which does not contain a matting agent.
Acrylic matte paint tree without noomer as a copolymer component
A fat, (meth) acrylic acid alkyl ester having a carbon number 1 to 4 (a) alkyl groups, (b) carbon atoms (a) differs from the number of carbon atoms in the alkyl group is from 1 to 4 (meth ) Alkyl acrylates and (c) alkyl (meth) acrylates having 5 or more carbon atoms in the alkyl group, wherein the content of (a) and (b) is 20 to 90% by weight, and the content of (c) In producing a matte coating resin having a ratio of 80 to 10% by weight, first, (a) is polymerized in the first step, and then (b) and (c) are polymerized in the second step. (A) and (c) are polymerized in the first stage, (b) is then polymerized in the second stage, and the degree of polymerization in the first stage is 70% or more. Manufacturing method of resin for eraser paint.