JPH0680904A - Emulsified film-forming assistant - Google Patents

Abstract

PURPOSE:To obtain a resin emulsion excellent in safety, miscibility with water, film-forming properties and freeze-thaw stability. CONSTITUTION:The assistant comprises an aqueous resin emulsion comprising a compound of the general formula: R<1>-(AO)nH wherein R<1> is 1-6C alkyl or alkenyl; AO groups are 2-4C alkylene oxide groups and may be bonded together in a manner of block addition or random addition; and n is an integer of 1-10.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a film-forming aid which improves the film-forming property of an aqueous resin emulsion.

[0002]

2. Description of the Related Art A resin emulsion is used as a coating composition for paper, metal, concrete, etc., but in recent years, an aqueous emulsion has been used from the viewpoint of safety and pollution problems. However, there is a problem in the adhesiveness and releasability of the coating film at the time of application, and organic solvents, phthalic acid ester-based plasticizers and the like have hitherto been used to improve such defects. However, the organic solvent has a low flash point and is highly toxic, which causes a problem in safety such as working environment. Further, when a plasticizer such as a phthalate ester type is used, it is oil-soluble and therefore has a drawback of poor compatibility with an aqueous emulsion.

[0003]

SUMMARY OF THE INVENTION The present invention solves the conventional drawbacks, and an object of the present invention is to provide a film-forming auxiliary having high safety and excellent compatibility with an aqueous emulsion. .

[0004]

According to the present invention, by using a reaction product of an aliphatic lower alcohol or a derivative thereof and an alkylene oxide, the flash point is higher than that of the solvent and the safety is high. And a film forming aid having excellent compatibility with an aqueous resin emulsion. Also, by adjusting the addition amount of the film-forming auxiliary,
It also has a feature that the film forming temperature of the resin emulsion can be easily adjusted.

That is, an object of the present invention is to provide a film-forming aid characterized by containing the compound represented by Chemical formula 1 as an essential component.

Embedded image R1- (AO) nH (R1: alkyl group or alkenyl group having 1 to 6 carbon atoms AO: alkylene oxide having 2 to 4 carbon atoms, which may be block-added or random-added May be n: integer of 1 to 10)

The present invention will be described in detail below.

The compound of formula 1 used in the present invention is an aliphatic alcohol having a branched or linear alkyl group or alkenyl group having 1 to 6 carbon atoms, or similar polyalkylene having 1 to 6 carbon atoms. It can be prepared by adding an alkylene oxide to a glycol monoalkyl (alkenyl) ether.

Specific examples of the aliphatic lower alcohol include
Methanol, ethanol, 1-propanol, 1-butanol, 2-butanol isobutyl alcohol, ter
t-butyl alcohol, 1-pentanol, 2-pentanol, 3-pentanol, 2-methyl-1-butanol, isopentyl alcohol, tert-pentyl alcohol, 3-methyl-2-butanol, neopentyl alcohol, 1 -Hexanol, 2-methyl-1-pentanol, 4-methyl-2-pentanol, 2-ethyl-
1-Butanol, allyl alcohol and the like can be mentioned.

Specific examples of the polyalkylene glycol monoalkyl (alkenyl) ether include diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, triethylene glycol monomethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, Examples include tripropylene glycol monomethyl ether and the like. Of the above compounds, those having an alkyl group or alkenyl having 2 to 4 carbon atoms are preferable.

These alcohols may be used alone or in combination of two or more.

Specific examples of the alkylene oxide include ethylene oxide, propylene oxide, butylene oxide, styrene oxide, glycidol, tetrahydrofuran, epichlorohydrin and the like, but ethylene oxide and propylene oxide are preferably used.

The alkylene oxides may be used alone or in combination of two or more kinds, and in the latter case, they may be blocks, random addition, or a mixed system of both.

The total number of moles of alkylene oxide added is 1 to 10 moles, more preferably 2 to 6 moles. Among them, those obtained by adding 1 to 4 mol of ethylene oxide and 1 to 4 mol of propylene oxide are preferable.

The film-forming aid of the present invention has 1 to 6 carbon atoms and 1 to 10 moles of alkylene oxide added, and outside this range, it is oil-soluble or solid at room temperature. , The solubility in water tends to be poor.

The blending amount of the alkylene oxide adduct is 0.5 with respect to 100 parts by weight of the resin aqueous emulsion.
10 to 10 parts by weight, preferably 1 to 7 parts by weight. 0.5
If it is less than 10 parts by weight, no sufficient effect is observed, and if it is more than 10 parts by weight, the glass transition point of the resin is lowered and the coating surface becomes sticky.

[0016]

[Method of use] The resin aqueous emulsion in which the film-forming auxiliary of the present invention is used is an emulsion-dispersion product of a vinyl-based monomer and a powder resin in an aqueous medium consisting of water or a mixture with a small amount of aqueous alcohol. The resin concentration is generally 30 to 60% by weight. Among them, those obtained by emulsion-polymerizing vinyl monomers are preferable.

Examples of vinyl monomers used in emulsion polymerization include acrylic monomers such as acrylic acid ester, methacrylic acid ester, acrylic acid, methacrylic acid and acrylonitrile, and styrene monomer such as styrene and α-methylstyrene. , Vinyl acetate, acrylamide, maleic acid, fumaric acid, itaconic acid, etc.,
One kind or a mixture of two or more kinds is used. The above resin aqueous emulsion is produced by emulsion polymerization of these monomers by a conventional method.

The resin aqueous emulsion contains inorganic pigments such as clay, calcium carbonate, titanium oxide and talc, which are added when used as a coating composition, color pigments, thickeners, plasticizers and defoamers. It does not matter even if a preservative or a release agent is added.

[0019]

EFFECTS OF THE INVENTION By using the film-forming aid of the present invention, a resin film free from cracks during film formation and having a smooth surface is formed, and at the same time, the freeze-thaw stability of the resin aqueous emulsion is improved. Become.

[0020]

EXAMPLES The present invention will be specifically described with reference to Examples.
The present invention is not limited to these. The "parts" and "%" shown in the examples are based on weight.

Reference Example 1 (Production Method of Aqueous Resin Emulsion) A monomer mixture consisting of 52 parts of methyl methacrylate, 27 parts of styrene, 18 parts of n-butyl acrylate and 3 parts of methacrylic acid was mixed with an emulsifier in the presence of an emulsifier. Emulsion polymerization was performed in water using potassium sulfate as an initiator to obtain an emulsion having a resin content of 40% (emulsion 1).

Reference Example 2 (Production Method of Resin Aqueous Emulsion) In the same manner as in Reference Example 1, 25 parts of methyl methacrylate,
A monomer mixture consisting of 30 parts of styrene, 20 parts of ethyl acrylate, 22 parts of n-butyl acrylate and 3 parts of acrylic acid was emulsion polymerized to obtain an emulsion having a resin content of 40% (emulsion 2).

Example 1 (No. 1 to 5), Comparative example (N
o. 6) To the resin emulsions obtained in Reference Examples 1 and 2, the compounds shown in Table 1 were added to 100 parts of the resin emulsion in a predetermined amount (in terms of active ingredient), and then the presence or absence of cracks in the film was measured by the following method. The freeze stability of the emulsion was evaluated. The evaluation results are shown in Table 1.

[Crack of film] The emulsion was applied on a glass plate and dried at room temperature to form a film having a thickness of 0.2 mm, and the appearance was judged. ○: There is no crack. X: Cracks do not form a film.

[Freezing Stability of Emulsion] The emulsion was placed in a plastic bottle, allowed to stand in a constant temperature bath at -30 ° C. for 16 hours, and then the appearance of the emulsion when observed at room temperature was observed. ◯: A substance that returned to an emulsion state after being frozen and thawed. X: Those that did not solidify into a liquid even after returning to room temperature after freezing.

[0026]

[Table 1]

Claims (2)

[Claims] 1. A film-forming aid for an aqueous resin emulsion, which comprises the compound represented by Chemical formula 1 as an essential component. Embedded image R1- (AO) nH (R1: alkyl group or alkenyl group having 1 to 6 carbon atoms AO: alkylene oxide having 2 to 4 carbon atoms, which may be block-added or random-added May be n: integer of 1 to 10) 2. The resin aqueous emulsion is obtained by emulsion-polymerizing a vinyl-based monomer.
The film-forming aid described.