JPH0798913B2 - Manufacturing method of resin for matte paint - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for producing a paint resin for matting by a specific polymerization method.

[Prior Art] Matting paint is a matting agent such as fine powder silica,
It is made by adding polyethylene fine powder and the like to generate microscopic unevenness on the surface of the coating film, and lower the gloss by irregular reflection of light. However, in such a treatment method, the delusterant is liable to be adversely affected, and for example, when the coating film is rubbed, the portion is glossed and the appearance becomes unbalanced.

[Problems to be Solved by the Invention] Therefore, it can be said that if a practical delustering paint can be produced without using such a delustering agent, its industrial usefulness will be extremely great. The purpose of the present invention is to obtain a practical matte paint without blending an eraser.

[Means for Solving the Problems] In the present invention, (a) a styrene compound is 10 to 50% by weight, and (b) an alkyl group (meth) acrylic acid alkyl ester having 5 or more carbon atoms is 10 to 30% by weight. % (C) In the production of a resin comprising 20 to 80% by weight of (meth) acrylic acid alkyl ester having 1 to 4 carbon atoms in the alkyl group, the polymerization rate of (a) and (b) is 70 to When 90% is reached, by adding (c) and further proceeding the polymerization, the above-mentioned object can be achieved and a resin useful as a resin for a matte coating can be obtained. In the component constituting the resin, the styrene compound (a) 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. Alkyl (meth) acrylate having 5 or more carbon atoms in the alkyl group (b) has 10 to
It is 30% by weight, preferably 15 to 25% by weight. If it is 10% by weight or less, the matte effect is insufficient, while if it is 30% by weight or more, the matte effect is insufficient.

The (meth) acrylic acid alkyl ester having 1 to 4 carbon atoms in the alkyl group (c) is 20 to 80% by weight, preferably 30 to
60% by weight. If it is 20% by weight or less, the matte effect is insufficient, and if it is 80% by weight or more, the resin solution separates into layers.

In producing the resin of the present invention, solution polymerization using an organic solvent is usually carried out. First, a predetermined amount of (a) and (b) is dissolved in an organic solvent and the radical polymerization catalyst is used to polymerize (a) and (b). The polymerization rate of (a) and (b) (C) was added to the system when
The polymerization is further advanced to obtain the desired resin solution.

The polymerization rate is measured as a percentage of the heating residue and the theoretical heating residue in the sample by sampling the resin solution during the polymerization.

When (c) is added when the polymerization rate is less than 70% and the polymerization is further advanced, the matting effect is insufficient, and when (c) is exceeded and 90% is exceeded, further polymerization is obtained. The resin solution thus obtained is not preferable because the defects such as layer separation become remarkable.

Examples of the styrene compound (a) include styrene and vinyltoluene.

Examples of the (meth) acrylic acid alkyl ester in which the alkyl group of (b) has 5 or more carbon atoms 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 can be used alone or in combination of two or more. As another monomer, a small amount of a hydroxy group-containing alkyl (meth) acrylate such as 2-hydroxyethyl (meth) acrylate or 2-hydroxypropyl (meth) acrylate may be used in combination.

Examples of the (meth) acrylic acid alkyl ester having 1 to 4 carbon atoms of the alkyl group of (c) include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, and isopropyl (meth) acrylate. , Butyl (meth) acrylate, isobutyl (meth) acrylate, sec-butyl (meth) acrylate, t- (meth) acrylate
Butyl etc. are mentioned, and they are used individually or in combination of 2 or more types.

If necessary, as another monomer, a hydroxyl group-containing alkyl (meth) acrylate such as 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, a polymerizable amide such as (meth) acrylamide, acetic acid Vinyl, vinyl compounds such as vinyl propionate, unsaturated carboxylic acids such as (meth) acrylic acid, crotonic acid, itaconic acid, (anhydrous) maleic acid and fumaric acid, basic monomers such as dimethylaminoethyl acrylate and diethylaminoethyl methacrylate A small amount of (meth) acrylic acid alkyl ester having an alkyl group having 5 or more carbon atoms may be used together.

The coating resin of the present invention is preferably produced by a solution polymerization method using an organic solvent, as described above, but as the organic solvent, toluene, an aromatic hydrocarbon such as xylene, ethyl acetate, Examples include esters such as butyl acetate, ketones such as methyl ethyl ketone and methyl isobutyl ketone, isopropyl alcohol, aliphatic alcohols such as n-butanol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, and the like, which may be used alone or in combination. Aromatic hydrocarbons such as, and xylene are preferably used alone or in combination.

As the polymerization catalyst, known radical polymerization catalysts such as azobisisobutyronitrile, benzoyl peroxide, ditertiary butyl peroxide and cumene hydroperoxide are used.

A suitable temperature for the polymerization is 60 to 150 ° C., and a practical polymerization time is about 6 to 20 hours.

The coating resin of the present invention can be put to practical use as a coating resin in a state where the organic solvent used during the polymerization is directly used as a solvent as described above, but if necessary, it may be replaced with any solvent. You can use it.

Examples of pigments used when preparing coating materials using the coating resin of the present invention include titanium oxide, calcium carbonate, talc, lithobon, barium sulfate, calcium sulfate, alumina, white pigments such as clay, carbon black, iron black. Such as black pigments, phthalocyanine blue, navy blue, ultramarine blue pigments, lake yellow, yellow lead, oak yellow, hansa yellow, etc. yellow pigments, red iron oxide such as red iron oxide, lake red, chrome vermilion, etc., phthalocyanine Examples include green pigments and green pigments such as chromium oxide.

In addition, if necessary, a plasticizer, an anti-sagging agent, an anti-settling agent, an antifoaming agent and the like are appropriately added.

A sand mill, a disper, a ball mill and the like which are usually used are used for preparing the paint. As a coating method of the obtained coating material, a method such as iron coating, brush coating, roller coating, spray coating or the like is adopted.

When this paint is used as a top coat paint for exterior materials such as concrete, mortar buildings, roof tiles and siding boards, and as a paint for interiors and floors of buildings, it gives a calm finish.

[Operation] In the present invention, the components (a), (b), and (c) are polymerized in two stages to produce a practical matting paint without using a matting agent. I can.

EXAMPLES Next, the present invention will be described in more detail by way of examples.

Example 1 A 4-liter four-necked flask equipped with a stirrer, a thermometer, and a condenser, 325 parts of styrene, 260 parts of 2-ethylhexyl acrylate, 320 parts of toluene, and benzoyl peroxide 1.
5 parts were charged, the polymerization was started at a temperature of 90 ° C., benzoyl peroxide was added on the way, and the polymerization rate reached 90% within 6 hours from the start of the polymerization, so 715 parts of methyl methacrylate was gradually charged. After continuing the reaction for an additional 4 hours, add toluene and cool to a solid content concentration of 45% and a viscosity of 3500 cps / 25 ° C.
To obtain a resin solution (A-1). The composition of (A-1) was 25% by weight of styrene, 20% by weight of 2-ethylhexyl acrylate and 55% by weight of methyl methacrylate.

Example 2 The same flask as in Example 1 was charged with 390 parts of styrene, 195 parts of 2-ethylhexyl acrylate, 320 parts of toluene, and 1.5 parts of benzoyl peroxide, polymerization was initiated at a temperature of 90 ° C., and benzoyl peroxide was added on the way. Then, after the polymerization rate reached 90% within 6 hours from the initiation of polymerization, 715 parts of n-butyl methacrylate was gradually charged. After continuing the reaction for another 4 hours, add toluene and cool to obtain a solid content concentration.
A resin solution (A-2) having 45% and a viscosity of 3000 cps / 25 ° C. was obtained.
The composition of (A-2) is 30% by weight of styrene and 2-acrylic acid.
It was 15% by weight of ethylhexyl and 55% by weight of n-butyl methacrylate.

Example 3 The same flask as in Example 1 was charged with 260 parts of styrene, 195 parts of lauryl methacrylate, 320 parts of toluene, and 1.5 parts of benzoyl peroxide, and polymerization was started at a temperature of 90 ° C.
Benzoyl peroxide was added on the way, and after the polymerization rate reached 85% within 7 hours from the start of polymerization, 845 parts of methyl methacrylate was gradually charged. After continuing the reaction for another 4 hours, add toluene and cool to obtain a solid content concentration of 45% and a viscosity.
A resin solution (A-3) of 4000 cps / 25 ° C was obtained. (A-3)
The composition was 20% by weight of styrene, 30% by weight of lauryl methacrylate and 65% by weight of methyl methacrylate.

Example 4 260 parts of styrene, 390 parts of lauryl acrylate, 320 parts of toluene, and 1.5 parts of benzoyl peroxide were charged in the same flask as in Example 1, polymerization was started at a temperature of 90 ° C., and benzoyl peroxide was added on the way. After the polymerization rate reached 80% within 6 hours from the start of polymerization, ethyl methacrylate 65
0 copies were gradually added. After continuing the reaction for another 4 hours,
Toluene is added and cooled, solid content concentration 45%, viscosity 3800
A resin solution (A-4) of cps / 25 ° C was obtained. The composition of (A-4) is 20% by weight of styrene, 30% by weight of lauryl acrylate,
It was 50% by weight of ethyl methacrylate.

Comparative Example 1 325 parts of styrene, 2-ethylhexyl acrylate 2 in a 4 l four-necked flask equipped with a stirrer, a thermometer, and a condenser.
60 parts, 715 parts of methyl methacrylate, 520 parts of toluene and 1.2 parts of benzoyl peroxide were charged, and polymerization was started at a temperature of 90 ° C. Add benzoyl peroxide on the way,
After continuing the polymerization and reacting for 9 hours, toluene was additionally added and cooled to obtain a resin solution (B-1) having a solid content concentration of 45% and a viscosity of 3300 cps / 25 ° C. The composition of (B-1) was the same as that of (A-1).

Comparative Example 2 A resin (B-2) having a solid content concentration of 45% by weight was obtained by the same method as in Example 1 except that the polymerization rate of (a) and (b) was changed to 65%. It was

Comparative Example 3 A resin (B-3) having a solid content concentration of 45% by weight was obtained by the same method as in Example 1 except that the polymerization rate of (a) and (b) was changed to 95%. However, the resin solution was unstable and the layers were separated.

Preparation of paint and measurement of coating appearance 30 parts of resin solution with 40 parts of titanium oxide and 100 parts of glass beads 2
Place in a 50 ml glass bottle, shake with a paint conditioner for 30 minutes to disperse, and then add the same resin solution to 60 ml.
Parts were added and shaken with a paint conditioner for 10 minutes to obtain a white paint.

A white paint was obtained in the same manner as above for the resin solution of the control example.

To 100 parts of the white paint obtained, 40 parts of toluene / xylene (= 1/1) was added to dilute it, and then it was applied to a tin plate with a bar coater # 50 and dried, and then the specular gloss at 60 degrees was measured with a gloss meter. After that, white paints (A-1), (A-2), (A
-3) and (A-4) have a gloss of 35, 30, 25 and 20, respectively, and the white paints (B-1) and (B-2) have a gloss of 7 respectively.
It was 5, 60.

[Effect] In 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)

[Claims] (A) 10 to 50% by weight of a styrene compound (b) 10 to 30% by weight of (meth) acrylic acid alkyl ester having 5 or more carbon atoms in an alkyl group (c) Number of carbon atoms in an alkyl group In producing a resin for a matte coating containing 20 to 80% by weight of (meth) acrylic acid alkyl ester of 1 to 4,
A method for producing a resin for a matte coating, which comprises first polymerizing (a) and (b) and then further polymerizing (c) after the polymerization rate reaches 70 to 90%.