JPS61113663A - Aqueous dispersion composition with high water repellency - Google Patents

Abstract

PURPOSE:To obtain the titled composition for coating on paper, knits, leathers, etc., capable of forming dry film of high water repellency by incorporating specific aqueous polymer dispersion with an alkali salt aqueous solution of specific copolymer and a small amount of water repellant. CONSTITUTION:The objective composition can be obtained by incorporating (A) 100pts.wt., on a dry basis, of an aqueous polymer dispersion capable of forming water-resistant dry film with (B) 0.5-10pts.wt., on a dry basis, of an alkali salt aqueous solution of a carboxyl group-contg. copolymer with [eta]<=0.3 (measured at 25 deg.C in the form of dimethylformamide solution) capable of forming water-repellent dry coating film (e.g., a copolymer made up of 6-30pts. wt. of unsaturated carboxylic acid consisting mainly of <=10C monobasic acid and 94-70pts.wt. of a monomer consisting mainly of hydrophobic radically polymerizable unsaturated compound) and (C) 0.5-10pts.wt. of a nonvolatile water repellant.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an aqueous coating dispersion composition with excellent water repellency, and more particularly, to an aqueous aqueous dispersion of a specific polymer and an aqueous alkali salt solution of a specific copolymer and a small amount of The present invention relates to an aqueous dispersion composition for coating that forms a dry film with excellent water repellency and contains a water repellent.

Generally, in order to create an aqueous dispersion composition that forms a dry film with excellent water repellency from an aqueous polymer dispersion, a water repellent, and other additives, a large amount of the water repellent is mixed into the composition. Must. However, when various objects are coated with an aqueous dispersion composition containing a large amount of water repellent, problems often arise such as the water repellent coming out on the surface of the coating film and spoiling its appearance. In order to solve this problem, the inventors of the present invention made efforts to produce an aqueous dispersion composition that exhibits excellent water repellency even with a small content of water repellent agent.

By using an aqueous dispersion of a specific polymer and an aqueous alkali salt solution of a specific copolymer, an aqueous dispersion composition that forms a dry film with excellent water repellency can be obtained even if the content of the water repellent is small. We discovered this and arrived at the present invention.

That is, the present invention provides an aqueous solution of an alkali salt of a carboxyl group-containing copolymer that forms a dry coating film with good water repellency, based on 100 parts by dry weight of an aqueous polymer dispersion that forms a dry coating film with good water repellency. An object of the present invention is to provide an aqueous dispersion composition having excellent water repellency, characterized in that it contains 0.5 to 10 parts by dry weight and 0.5 to 10 parts by weight of a nonvolatile water repellent.

The aqueous polymer dispersion that forms a dry film with good water resistance used in the present invention is a film formed by pouring the aqueous dispersion thinly onto a glass plate and thoroughly drying it at about 20°C. When a drop of water is placed on a glass, covered with a watch glass, and left to stand at about 20°C, it does not turn white even after one hour has passed.

It goes without saying that the longer the time required for whitening, the better.

The monomers constituting the aqueous polymer dispersion include, for example,
Various acrylic acid esters, methacrylic acid esters, maleic acid diesters, fumaric acid diesters, itaconic acid diesters and other unsaturated carboxylic acid esters, α-olefins such as ethylene and isobutylene, and chloride. Vinyl, vinyl halides such as vinylidene chloride or vinylidene, styrene,
Aromatic vinyl compounds such as vinyltoluene, divinylbenzene, α-methylstyrene, conjugated diolefins such as butadiene, isoprene, and dimethylbutadiene, vinyl esters such as vinyl acetate, vinyl propionate, and vinyl versatate, (meth)acrylonitrile, ) Acrylamide, hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, glycidyl (meth)acrylate, N-methylol (meth)acrylate
Acrylamide, N-butoxymethylol (meth)acrylamide, dimethylaminoethyl (meth)acrylate, diacetone (meth)acrylamide, maleic acid,
Examples include dibasic unsaturated carboxylic acids such as fumaric acid and itaconic acid and their monoesters, and monobasic unsaturated carboxylic acids such as acrylic acid, methacrylic acid, crotonic acid, vinylbenzoic acid, and cinnamic acid.

The aqueous polymer dispersion described above is produced by emulsion polymerization of one or more of these monomers. At this time, hydrophilic monomers and low molecular weight emulsifiers (
For example, the smaller the amount of anionic and nonionic surfactants used, the better the water resistance of the dried film formed from the resulting aqueous polymer dispersion.

When the aqueous polymer dispersion after emulsion polymerization is acidic, a volatile basic substance is added to adjust the pH to 6 to 10 to improve the stability of the dispersion and to improve the dry film formation. Minimize the decline in water resistance.

Volatile basic substances include, for example, ammonia (water)
, triethylamine, diethylamine, monoethylamine, dimethylethanolamine, monoethanolamine, etc., but ammonia (water) is the cheapest and preferred.

In addition, some of these volatile basic substances can be replaced with non-volatile basic substances such as sodium hydroxide, potassium hydroxide,
It is also possible to substitute with sodium carbonate, potassium carbonate, etc.

In the present invention, the aqueous polymer dispersion may be a mixture of two or more. In this case, the water resistance of the dry film formed from the liquid mixture must be good as described above.

The aqueous solution of an alkali salt of a carboxyl group-containing copolymer that forms a dry coating film with good water repellency used in the present invention refers to the aqueous solution (approximately 20% by weight) that is applied to a concrete slab (
30 x 30 x 5.5 cm) on a fresh surface, approx.
After sufficiently drying at 0°C, when water is poured onto the coated surface, it exhibits good water repellency. At this time, a coating film that is not water repellent swells or dissolves with water.

This carboxyl group-containing copolymer includes, for example, acrylic acid, methacrylic acid, crotonic acid, vinylbenzoic acid,
From 6 to 30% by weight of an unsaturated carboxylic acid whose main component is a monobasic acid having 10 or less carbon atoms, such as isopropenylbenzoic acid and cinnamic acid, and 94 to 70% by weight of other monomers. There are things that are made up of.

Examples of monomers other than unsaturated carboxylic acids include unsaturated carboxylic esters such as various acrylic esters and methacrylic esters having an alkyl group having 1 to 18 carbon atoms, acrylonitrile, methacrylonitrile, etc. These include vinyl cyanide compounds, α-olefins such as ethylene and isoptylene, aromatic vinyl compounds such as styrene, vinyltoluene, and α-methylstyrene, and conjugated diolefins such as butadiene, isoprene, and dimethylbutadiene, which have particularly low solubility in water. Preferably.

These monomers may be used alone or in a mixture of two or more.

Hydrophilic monomers having functional groups other than carboxyl groups may be included in the components of this carboxyl group-containing copolymer, but as their content increases, the water repellency of the dried coating film decreases.

This carboxyl group-containing copolymer reacts with the aforementioned volatile basic substance, particularly ammonia (water), to form an aqueous alkali salt solution.

In order to improve the dissolution state of this aqueous solution, the [η] (value measured at 25°C using dimethylformamide as a solvent) of the carboxyl group-containing copolymer must be 0.3 or less, especially 0.
It is preferably 2 or less, and the unsaturated carboxylic acid content is preferably 6% by weight or more, particularly 8% by weight or more.

If this content exceeds 30% by weight, the water repellency of the dried coating film formed from the aqueous alkali salt solution tends to decrease.

This aqueous solution of an alkaline salt of a carboxyl group-containing copolymer is useful as a dispersion stabilizer for aqueous polymer dispersions and various compositions made therefrom. For example, the stability of the aqueous polymer dispersion at the final stage of polymerization or after polymerization is significantly improved by adding this aqueous alkali salt solution.

Further, when fillers, pigments, plasticizers, other additives, etc. are directly mixed with the aqueous polymer dispersion used in the present invention to form a dry film with good water resistance, coagulation often occurs.

However, if the aqueous alkali salt solution is added to stabilize the aqueous polymer dispersion before directly mixing them, the formation of coagulates will be prevented or the amount thereof will be significantly reduced.

The amount of the aqueous alkali salt solution of the carboxyl group-containing copolymer to be used should be determined depending on the stability of the aqueous polymer dispersion and the types and amounts of fillers and various additives. 0.5 to 10 parts by dry weight per 100 parts by dry weight are suitable. If the amount used is less than 0.5 parts by dry weight, stabilization will be insufficient. Also, 10
It is economically unfavorable to use more than part by dry weight.

The use of this aqueous alkaline salt solution allows the use of low molecular weight surfactants and low degree of polymerization water-soluble polymers (e.g., polyvinyl alcohol,
Discontinue use of sodium polyacrylate) or
Or their usage can be reduced.

When a large amount of these water-soluble substances is contained in the aqueous dispersion composition, the water repellency of the dried film of the composition decreases.

The filler (extender pigment) used in the present invention is preferably hydrophobic. A typical example is calcium carbonate. Hydrophilic fillers such as bentonite clay and hydrous silicic acid should not be used.

Pigments, like fillers, must also be selected to be hydrophobic. As the white pigment, rutile-type titanium oxide is suitable.

The amount of these fillers and pigments to be used must be appropriately selected depending on the purpose of use of the aqueous dispersion composition, but the total amount should be 800 parts by weight per 100 parts by dry weight of the aqueous polymer dispersion. If it exceeds this amount, the water permeability of the dried film of the aqueous dispersion composition will increase undesirably.

Non-volatile water repellents used in the present invention include, for example:
Examples include paraffin type, olefin type, heavy metal salt type of higher fatty acid, silicon compound base, fluorine compound type, and zirconium compound type. The amounts used must be appropriately determined depending on the types and amounts of water-soluble substances, hydrophilic substances, fillers, pigments, etc. contained in the aqueous dispersion composition.
0.5 to 1 per 100 parts by dry weight of the aqueous polymer dispersion
0 weight parts are suitable, and 1 to 5 weight parts are particularly preferred.

If this amount is less than 0.5 part by weight, water repellency will be insufficient. Moreover, if the amount is more than 10 parts by weight, the appearance of the dried coating film will deteriorate and it is not economically preferable.

The composition of the present invention may further contain a plasticizer, a film-forming aid, a light stabilizer, a crosslinking agent, an antifoaming agent, a thickener, a preservative, a fungicide, a rust preventive, etc., depending on the intended use. Ru. Among these, the amount of water-soluble substances and hydrophilic substances added must be as small as possible.

The aqueous dispersion composition of the present invention exhibits excellent water repellency despite having a small content of water repellent.

For this reason, various molded products made from concrete, mortar, cement, etc., calcium silicate plates, magnesium carbonate plates, iron plates, sub-plated iron plates, aluminum plates,
It is useful as a coating material for other building materials, roofs of building boards, walls, ceilings, fittings, furniture, and other emulsion paints, and as a waterproofing material, anticorrosion material, rustproofing material, and sealing material. Further, by blending sand, granular foamed resin, foamed rubber, various hydrophobic fibers, etc. with the composition of the present invention, a composite paint with excellent water repellency can be obtained. Furthermore, the composition of the present invention can also be used as a coating material for paper, nonwoven fabrics, woven fabrics, knitted fabrics, leather, and the like.

When applying the composition of the present invention to these uses, the composition may be applied using a roller, doctor knife, spray, dipping, brush, trowel,
A commonly used method such as painting with a spatula or the like can be applied.

Next, the present invention will be explained in more detail with reference to Examples. In addition, in the following, parts and % are parts by weight and weight %, respectively.
shows.

Example 1 (1) Aqueous solution of alkaline salt of carboxyl group-containing copolymer Composition of carboxyl group-containing copolymer and PH, P- of [η] (value measured at 25°C using dimethylformamide as a solvent) and ammonium salt aqueous solution 1 P-2 P-3
P-4 P-5 P-6 methacrylic acid 13
8 10 15 25 40
% Methyl methacrylate 67 12
10 15 60 Styrene 20 20 20 2
0 25 Butyl acrylate 60 60 50 50
〃[η] 0.12
0.10 0.11 0.12 0.15 0.13N
H4 salt aqueous solution PH 10.2 10.1 10.3
10.2 10.0 9.8 Solid content 2
0.1 20.2 20.3 20.2 20.3 2
Displayed as 0.1% solids.

These ammonium salt aqueous solutions were poured onto concrete flat plates (3
0 x 30 x 5.5 cm) on a fresh surface, approx.
After drying at ℃ for 20 days, water was poured on the painted surface, and P
-1, P-2, P-3, P-4, and P-5 all showed good water repellency, but P-6 did not repel water and swelled.

(2) Polymer aqueous dispersion polymer L-1 L-2
Composition and polymer composition Butyl acrylate 60 60 parts Polymer methyl methacrylate 39 37
100 parts acrylic acid 1
3 DBS-Na for 〃
1.5 3 〃 After neutralization with dodecyl ammonia PH 7.4 7.5
Benzene solid content
48.8 49.2% Sulfone drying
1 hour 1 hour
White even after the acid sodium film
Within um (D water resistance
No bleaching Whitening BS-Na
)normal
The content of water, the pH of the aqueous polymer dispersion neutralized with aqueous ammonia, and the solid content were displayed. The aqueous polymer dispersions L-1 and L-2 were thinly poured onto a glass plate and heated for about 20 minutes.
A transparent dry film was formed by standing at ℃ for 20 days. Place a drop of water on the surface of this film and cover it with a watch glass for about 2
The film was left standing at 0°C and the whitening state of the film was observed. The dried film of L-1 had good water resistance, but that of L-2 had poor water resistance.

(3) Manufacturer of an ammonium salt water formulation of the carboxyl group-containing copolymer that forms a dry coating film with good water repellency from an aqueous dispersion composition 4. Sannopco Co., Ltd. 5. Dow Chemical Co., Ltd. 6. Mitsubishi Petrochemical Co., Ltd. BTX mixed residue 7. Toyo Soda Co., Ltd. Chlorinated paraffin 8. Daiichi Kigenso Kagaku Kogyo Co., Ltd. Zirconium-based9. Ishihara Sangyo Co., Ltd. 10. Sankyo Seifun Co., Ltd. 11. Daiichi Kogyo Seiyaku Co., Ltd. Combination prescription (1) 1. L-1 1002.
P-1 1.53.
Sodium tripolyphosphate 0.54. Nopco DF・122 (defoaming agent) 0.55. Dow Seal 75 (Fungicide) 0.26. Supersol 1500 57. toyoparatucus
150 108. Zircoper RP
(Water repellent) 1.59. Titanium oxide (rutile type)
4510. Escalon 100 (charcoal) 13511. Celogen WSA (CMC)
0.8 solution (P-1) and a polymer aqueous dispersion (L-1) that forms a dry film with good water resistance, the formulation (
An aqueous dispersion composition (solid content = 65.3%) was prepared by 1). This was applied onto the smooth surface of a flexible board and plywood and dried at about 20° C. for 20 days. When water was run over the surface, both showed good water repellency.

Also, instead of P-1, the above P-2, P-3, P-4, P
When similar experiments were conducted using -5, all showed good water repellency.

As a comparative experiment, P-6 was used instead of P-1 in formulation (1).
When a similar experiment was conducted using , it did not show good water repellency.

Also, instead of P-1, sodium salt of naphthalene sulfonic acid formalin condensate (Demol N, Kao Atlas Co., Ltd.)
When a similar experiment was carried out using a water repellent (manufactured by J.D. Co., Ltd.), it did not show good water repellency.

In addition, when a similar experiment was conducted using a polymer aqueous dispersion (L-2) in which the dry film did not have good water resistance in place of L-1 in formulation (1), it did not show good water repellency. Ta.

Based on these results, an aqueous dispersion composition was prepared using an aqueous copolymer dispersion that forms a dry film with good water resistance and an aqueous alkaline salt solution of a carboxyl group-containing copolymer that forms a dry film with good water repellency. It is clear that if produced, a composition can be obtained that forms a dry coating film with good water repellency even if the content of the water repellent agent is small.

Example 2 (1) Composition of aqueous polymer dispersion polymer, content of sodium dodecylbenzenesulfonate (DBS-Na) based on 100 parts of polymer, and PH and solid content of aqueous polymer dispersion neutralized with aqueous ammonia was displayed.

L-3 L-4 Also, polymerized butyl acrylate 60 60
Part Aqueous dispersion methyl methacrylate 9
9 〃 Liquid L-3, L-styrene
29 27 4 is glass methacrylic acid
1 3 〃 Pour a thin layer of hydroxyl acrylate onto a plate, approximately DBS-Na 1.9 3 〃 2
PH at 0℃ 7.6 7.5
Static solid content for 20 days 50.1 50
．． 3%. Leave to dry transparent for 1 hour. Dry film for 1 hour.
Water resistance that remains within the white range
No bleaching Whitening Normal condition of this film Yes Water droplets were placed on the surface, covered with a watch glass, and left to stand at about 20°C to observe the whitening state of the film. The dried film of L-3 had good water resistance, but the dried film of L-4 had poor water resistance.

(2) Aqueous dispersion composition formulation (2) Dry weight part 1
．． L-3 1002.
P-1 23. Sodium tripolyphosphate 0.54. Nopco DF 122 0.55. Dow Seal 75 0.26. Toyoparachus 150 107. Escalon 100 1458. Titanium oxide (
Rutile type) 359. Supersol 1500 510. Barium stearate 211. Zircoper R
P212. Celogen WSA
0.513. Vissurf S (manufactured by Kao Atlas Co., Ltd.) 0.3 Ammonium salt aqueous solution (P-1) of a carboxyl group-containing copolymer that forms a dry film with good water repellency and a polymer that forms a dry film with good water resistance Using the aqueous dispersion (L-3), an aqueous dispersion composition (solid content = 65.5%) was prepared according to the formulation (2). When this was applied to the smooth surface of a flexible board and plywood and dried at about 20° C. for 20 days, water was run over the coated surface, and it showed good water repellency.

The above P-2, P-3, P-4, P-5 instead of P-1
When similar experiments were conducted using , all showed good water repellency.

As a comparative experiment, P-6 was used instead of P-1 in formulation (2).
When a similar experiment was conducted using , it did not show good water repellency.

Further, when a similar experiment was conducted using a sodium salt of naphthalene sulfonic acid formalin condensate instead of P-1, good water repellency was not exhibited.

In addition, when a similar experiment was conducted using a polymer aqueous dispersion (L-4) whose dry film had poor water resistance in place of L-3 in formulation (2), it showed good water repellency. Nakatsuta.

Based on these results, an aqueous dispersion composition was manufactured using an aqueous polymer dispersion that forms a dry film with good water resistance and an aqueous alkaline salt solution of a carboxyl group-containing copolymer that forms a dry film with good water repellency. It is clear that a composition that forms a dry coating film with good water repellency can be obtained even if the water repellent content is small.

Claims (2)

[Claims] (1) Forming a dry film with good water repellency [η] = 0.3 or less (using dimethylformamide as a solvent) 0.5 to 10 parts by dry weight of an aqueous solution of an alkali salt of the carboxyl group-containing copolymer (A) (measured at 25°C) and 0.5 to 10 parts by weight of a nonvolatile water repellent. Aqueous dispersion composition with excellent water repellency (2) Carboxyl group-containing copolymer (A) has 10 carbon atoms
Unsaturated carboxylic acid 6~ whose main component is the following monobasic acid
30% by weight and 94 to 70% by weight of a monomer containing a hydrophobic radically polymerizable unsaturated compound as a main component. body composition