JP2000204313A - Coating for polyvinyl chloride - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a coating for polyvinyl chloride, capable of being well adhered to the surface of the polyvinyl chloride to give excellent weather resistance to the surface of the polyvinyl chloride by adding an aromatic alcohol to an acrylic resin emulsion. SOLUTION: This coating for polyvinyl chloride is obtained by mixing (A) an acrylic resin emulsion with (B) an aromatic alcohol (for example, benzyl alcohol) in an amount of preferably 10-25 pts.wt., more preferably 15-20 pts.wt., per 100 pts.wt. of the component A. The component A is preferably the emulsion of a copolymer comprising (i) 20-60 wt.% of styrene, (ii) 5-50 wt.% of butyl acrylate and/or 2-ethylhexyl acrylate, and (iii) 0-5 wt.% of an α,β-unsaturated carboxylic acid. The emulsion is preferably further mixed with (iv) a dialkylsulfosuccinate alkali metal salt.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coating agent for polyvinyl chloride used, for example, for waterproof sheets.

[0002]

2. Description of the Related Art Conventionally, an acrylic resin emulsion is coated on a polyvinyl chloride sheet used for a waterproof sheet or the like in order to improve the weather resistance of the polyvinyl chloride sheet. Emulsions such as rosin and petroleum resin are added to improve the adhesion to vinyl chloride.

[0003]

However, the above-mentioned conventional rosin, petroleum resin and the like have poor weather resistance and are liable to yellow, and may deteriorate the weather resistance of the acrylic resin coating film.

[0004]

The present invention, as a means for solving the above-mentioned problems, provides a coating agent for polyvinyl chloride obtained by mixing an aromatic alcohol with an acrylic resin emulsion. The acrylic resin emulsion is composed of 20 to 60% by weight of styrene, 2 to 50% of butyl acrylate and / or 2-ethylhexyl acrylate.
It is desirable that the emulsion be a copolymer of 0 to 5% by weight of an α, β-unsaturated carboxylic acid, and that an alkali metal salt of dialkyl sulfosuccinate is further added to the emulsion.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail. [Acrylic resin emulsion] The acrylic resin emulsion of the present invention is a homopolymer emulsion of acrylic ester or a copolymer emulsion of two or more acrylic esters, or copolymerizable with the acrylic ester alone or two or more acrylic esters. This is a copolymer emulsion of another vinyl monomer alone or with two or more thereof. Examples of the acrylic ester used in the present invention include methyl acrylate and methyl methacrylate (both acrylate and methacrylate are abbreviated as (meth) acrylate), ethyl (meth) acrylate, n-propyl (meth) acrylate, and n-butyl. (Meth) acrylate, iso-propyl (meth) acrylate, iso-butyl (meth) acrylate, t-butyl (meth) acrylate, cyclohexyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, 2-ethylhexyl (meth) acrylate , 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, stearyl (meth) acrylate, lauryl (meth) acrylate, dimethylaminoethyl (meth) acrylate, dimethylaminopropyl (Meth) acrylate and the like, and other vinyl monomers copolymerizable with the acrylic ester include, for example, α such as acrylic acid, methacrylic acid, itaconic acid, maleic acid, crotonic acid, atropic acid and citraconic acid. , Β-unsaturated carboxylic acid, styrene, α-methylstyrene, methyl vinyl ether, ethyl vinyl ether, n-propyl vinyl ether, n-butyl vinyl ether, iso-butyl vinyl ether, acrylonitrile, methacrylonitrile, vinyl acetate, vinyl propionate, chloride Vinyl, vinylidene chloride, allyl alcohol, (meth) acrylamide, diacetone acrylamide, glycidyl (meth) acrylate, glycidyl allyl ether, vinylpyrrolidone, vinylpyridine, vinylcarbazole and the like. The acrylic ester monomer alone or two or more or a monomer mixture of acrylic ester and another vinyl monomer copolymerizable with the acrylic ester is dispersed in water in the presence of a surfactant. Emulsion polymerization is performed by adding a polymerization initiator and stirring with heating to produce an acrylic resin emulsion. The surfactant used in the emulsion polymerization is usually an anionic surfactant and / or a nonionic surfactant, but a cationic surfactant may be used. Examples of the anionic surfactant include higher alcohol sulfate (Na salt or amine salt), alkyl allyl sulfonate (Na salt or amine salt), alkyl naphthalene sulfonate (Na salt or amine salt), and alkyl naphthalene sulfonate. Acid condensates, alkyl phosphates, dialkyl sulfosuccinates, rosin soaps, fatty acid salts (Na salts or amine salts), and the like. Examples of the nonionic surfactant include polyoxyethylene alkyl ether and polyoxyethylene alkyl phenol ether. , Polyoxyethylene alkyl ester, polyoxyethylene alkylamine, polyoxyethylene alkylolamine, polyoxyethylene alkyl amide, sorbitan alkyl ester,
There are polyoxyethylene sorbitan alkyl esters and the like, and as the above-mentioned cationic surfactant, there are trimethylaminoethylalkylamide halogenide, alkylpyridinium sulfate, alkyltrimethylammonium halogenide and the like. Examples of the polymerization initiator used in the emulsion polymerization include water-soluble inorganic polymerization initiators such as ammonium persulfate, potassium persulfate, sodium persulfate, and sodium perborate; and 2,2′-azobis (2-methylpropionamidine) dihydro. Chloride, 2,2'-azobis (2
Water-soluble organic polymerization initiator such as -methyl-N-phenylpropionamidine) dihydrochloride, or the above-mentioned inorganic or organic polymerization initiator and a reducing agent such as sodium sulfite, sodium bisulfite, sodium hyposulfite, and ascorbic acid in combination Redox polymerization initiator systems are exemplified. The above-mentioned vinyl monomer or vinyl monomer mixture is set at about 30 to 70% by weight based on the whole acrylic resin emulsion usually produced. The surfactant is used in an amount of 1.0 to 4.0 parts by weight based on 100 parts by weight of the vinyl monomer or the vinyl monomer mixture. The polymerization initiator is used in an amount of 0.1 to 0.5 part by weight based on 100 parts by weight of the vinyl monomer or the vinyl monomer mixture. The temperature applied in the emulsion polymerization is usually 30 to
It is about 90 ° C., and the polymerization time is usually about 4 to 10 hours. If desired, the emulsion polymerization may be performed in an inert gas atmosphere such as nitrogen. After the polymerization, if necessary, the pH may be adjusted by adding an alkali such as sodium hydroxide, potassium hydroxide or ammonia. In this way, an acrylic resin emulsion is produced. In the present invention, a desirable vinyl monomer formulation is 20 to 60% by weight of styrene, 5 to 50% by weight of butyl acrylate and / or 2-ethylhexyl acrylate, and α, β- 0-5% by weight of saturated carboxylic acid.

[Preparation of Coating Agent] A predetermined amount of aromatic alcohol is mixed with the acrylic resin emulsion of the present invention to form a coating agent. Examples of the aromatic alcohol include benzene methanol (benzyl alcohol), benzene ethanol, diphenyl methanol,
-Naphthalenemethanol, 1,2-benzenedimethanol and the like, and benzyl alcohol is particularly desirable. The aromatic alcohol slightly swells the surface of the polyvinyl chloride to enhance the adhesion to the acrylic resin emulsion film, and the aromatic alcohol is usually 10 to 10 parts by weight of the acrylic resin emulsion.
25 parts by weight, more preferably 15 to 20 parts by weight, is added. If the amount of the aromatic alcohol is less than 10 parts by weight, the adhesion of the acrylic resin emulsion film to polyvinyl chloride is reduced. If the amount exceeds 25 parts by weight, the surface of the polyvinyl chloride excessively swells and the acrylic resin emulsion There is a problem that a plasticizer contained in polyvinyl chloride is transferred to the coating. It is desirable to add an alkali metal salt such as a sodium salt, potassium salt, lithium salt or ammonium salt of a dialkyl sulfosuccinate as a wetting improver to the above-mentioned anionic or nonionic acrylic resin emulsion. The sodium salt of fosuccinate is preferred. The amount of the alkali metal salt of the dialkyl sulfosuccinate is usually about 1 to 5 parts by weight based on 100 parts by weight of the acrylic resin emulsion. The alkali metal salt of dialkyl sulfosuccinate contributes to the improvement of the wettability of the acrylic resin emulsion to polyvinyl chloride. However, if the amount of the alkali metal salt of dialkyl sulfosuccinate is less than 1 part by weight, the acrylic resin emulsion may have an acrylic resin emulsion. The wettability of the resin emulsion to polyvinyl chloride decreases, and if it exceeds 5 parts by weight, the water resistance of the coating film decreases. In the coating agent of the present invention, water is further added to the above composition to adjust the concentration of the acrylic resin resin suitable for coating.

[Application of Coating Agent] The polyvinyl chloride (PVC) which is the object of the present invention is usually a semi-hard or soft material to which a plasticizer such as dioctyl phthalate, dibutyl phthalate or tricresyl phosphate is added in an amount of 50 to 100% by weight. It is a PVC sheet. The coating agent of the present invention is coated on the PVC sheet by a knife coater, a flow coater, a spray or the like so as to have a predetermined thickness. When the PVC sheet is used as a waterproof sheet, the surface of the PVC sheet is coated with the acrylic resin of the present invention as an undercoat, and then a top coat agent is applied. Examples of the top coat agent include an asphalt emulsifier, a silicone resin emulsion, a fluorine resin emulsion, and a mixture of these with an acrylic resin emulsion.

[Example] In a flask equipped with a reflux condenser, a thermometer, an inert gas introduction pipe, a thermometer, etc., 50 parts by weight of water,
Dialkyl sulfosuccinate sodium salt (3 parts by weight) and ammonium persulfate (0.2 parts by weight) were charged at a temperature of 7%.
While heating to 0 ° C., a monomer mixture of 30% by weight of styrene, 18% by weight of butyl acrylate, and 1.5% by weight of acrylic acid was continuously dropped for approximately 6 hours. After completion of the dropwise addition, the mixture was maintained at 80 ° C. for 1 hour, cooled, neutralized with aqueous ammonia, and adjusted to pH 8,
An acrylic resin emulsion having a solid content of 50% by weight, a viscosity of 200 cps and an acrylic resin emulsion was obtained. Acrylic resin emulsion 4
To 00 parts, an emulsion composed of 70 parts by weight of benzyl alcohol, 3 parts by weight of sodium salt of dialkyl sulfosuccinate and 530 parts of ion-exchanged water was added and stirred to prepare a coating agent for polyvinyl chloride. The coating agent is applied to the following three types of PVC sheet surfaces at a coating amount of 0.2.
kg / m ² Apply evenly with a brush, 3 at 20 ° C, 60% RH
It was dried for a day to give a waterproof sheet. PVC sheet * 1: New PVC sheet irradiated by a sunshine carbon arc accelerated weathering tester for 1000 hours PVC sheet * 2: PVC sheet constructed 10 years ago PVC sheet * 3: New PVC sheet Waterproof The sheet was subjected to a weather resistance test, and the adhesion before and after the sheet was measured. As a weather resistance test, JI
SK5400 Paint General Test Method 9.8 A sunshine carbon arc-type accelerated weathering test was performed according to the accelerated weathering test, and irradiation was performed for 1,000 hours with the tester. In addition, the test for the adhesiveness of the squares was performed in accordance with the JIS K 5400 paint general test method 8.5.2. The slit width is set to 2 mm and JIS K
5400 Evaluated according to 8.5.1 (5) and expressed as a score. As the adhesive tape, a cellophane adhesive tape (width 18 mm, adhesive strength 3) specified in JIS Z 1522 is used.
00gf / 10 mm or more). Table 1 shows the results.

[0009]

[Table 1] Note) 10 points: Each cut is thin and both sides are smooth, and the intersection with the cut and the square are not peeled at a glance.

From the results shown in Table 1, the acrylic resin emulsion for a PVC sheet of the present invention has a good adhesion to a PVC sheet.

The coating agent of the present invention can be applied to polyester sheets, FRP, concrete panels, mortars and the like in addition to the above polyvinyl chloride.

[0012]

[Action and Effect] The acrylic resin emulsion of the present invention is
When applied to VC, the aromatic alcohol contained slightly swells the PVC surface, whereby the coating of the acrylic resin emulsion adheres well to the PVC surface. Therefore, it is not necessary to add an adhesion improver having poor weather resistance, such as rosin or petroleum resin, so that it is possible to give extremely excellent weather resistance and durability to the PVC surface, and it is possible to use PVC for a long period of time and to dispose of PVC. The quantity of objects can be greatly reduced.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Minoru Asano, Inventor Minami Nakagawa, Kasamatsu-cho, Hashima-gun, Gifu Prefecture, Japan 1762 Kita-Kaori, Kasamatsu-cho, Hashima-gun, Gifu Prefecture, Japan 1762 Inventor Masayuki Ogawa 3-28-30 Meieki Station, Nakamura-ku, Nagoya City, Aichi Prefecture Inside the Nagoya Branch of Mitsubishi Chemical Industrial Co., Ltd. (72) Inventor Toshihiro Yasuda 6-15-1, Nyoiroshi-cho, Kasugai-shi, Aichi Japan Nippon Parmil F term (reference) 4F006 AA17 AB16 AB24 BA03 CA06 4J002 BB041 BC071 BH011 EV256 GH00 HA07 4J038 CG141 CJ031 CJ131 JA19 JA48 KA06 MA08 MA10 NA04 PC08

Claims (3)

[Claims] 1. A coating agent for polyvinyl chloride, wherein an aromatic alcohol is mixed with an acrylic resin emulsion. 2. An acrylic resin emulsion comprising 20 to 60% by weight of styrene, 5 to 50% by weight of butyl acrylate and / or 2-ethylhexyl acrylate, α,
The coating agent for polyvinyl chloride according to claim 1, which is an emulsion of a copolymer of 0 to 5% by weight of β-unsaturated carboxylic acid. 3. The coating agent for polyvinyl chloride according to claim 1, wherein a dialkyl sulfosuccinate alkali metal salt is further added to said emulsion.