JPH01301762A - Aqueous coating agent composition - Google Patents

Abstract

PURPOSE:To obtain the subject composition having elasticity, abrasion, weather resistance and toughness, by polymerizing a radically polymerizable acrylic monomer containing a carbonyl group- or amide group-containing monomer in the presence of a specific aqueous polyurethane resin. CONSTITUTION:The objective composition obtained by polymerizing (B) a radically polymerizable acrylic monomer containing a carbonyl group- or amide group-containing monomer in an amount of >=0.5pt.wt. based on 100pts.wt. total polymerizable monomers in the presence of (A) an aqueous polyurethane resin prepared by reacting diisocyanates with glycols containing carboxylic acid group-containing glycols, neutralizing the resultant urethane prepolymer and extending the chain with a hydrazine catalyst at 100/5-5/100 solid weight ratio of the components (A)/(B).

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to aqueous coating compositions. For more details,
This relates to an aqueous coating composition obtained by polymerizing a radically polymerizable acrylic monomer in the presence of an aqueous polyurethane resin, which has the elasticity and abrasion resistance of the urethane resin,
It is a composition that functionally combines the weather resistance and toughness of acrylic resin, and is suitable for cement, concrete, metal,
It is widely used as a coating for paper, leather, wood, etc.

[Prior art and its problems] Conventionally, aqueous acrylic copolymer dispersions have been used as aqueous coating compositions for coating interiors and exteriors of buildings, leather, metals, wooden floors, etc. due to their excellent weather resistance and toughness. It has been used in a wide variety of applications such as impregnating fibers or as a binder, adhesives, and glues.

However, in recent years, quality has improved, coating base materials have changed,
As they are used in new applications, the performance requirements for coating compositions are becoming more sophisticated, and in addition to conventional weather resistance, the number of applications that require film elasticity and abrasion resistance comparable to that of urethane resins is increasing. It's coming.

In order to obtain such physical properties, various acrylic functional monomers are being considered as a method for improving aqueous acrylic copolymer dispersions, and it is difficult to obtain acrylic resins with elasticity comparable to urethane resins. Therefore, consideration was desired.

On the other hand, water-based polyurethane resin as a water-based coating composition is developed by focusing on the elasticity and abrasion resistance that are the characteristics of this resin.
Traditionally, it has been used to cover textiles, paper, leather, plus deck, wooden floors, etc., but when used in an air-dry condition, water resistance and Due to poor alkalinity and weather resistance, and poor film-forming properties between particles in urethane dispersion, which is thought to be caused by the strength of the cohesive force within the particles, it is only used indoors. Ta. In addition, in most cases, in practice, a crosslinking agent is used in combination and a high-temperature heat drying process is used, and the elasticity unique to urethane resins can only be obtained under these conditions.

In order to develop an aqueous coating composition that has the weather resistance and toughness of an acrylic resin in addition to the elasticity and abrasion resistance of a urethane resin, we developed a combination of an aqueous polyurethane resin and an aqueous acrylic copolymer dispersion. Is mixing etc. being considered? Mere mixing may actually lead to a combination of the disadvantages of each resin, namely the weak elasticity of the aqueous acrylic copolymer dispersion and the poor weather resistance of the aqueous polyurethane resin. In many cases, only one resin can be obtained, and there has been a strong desire to develop a resin that combines the characteristics of both.

[Means for Solving the Problems 1] The present inventors conducted research in order to develop an aqueous coating composition that has both the elasticity and abrasion resistance of urethane resins, as well as the weather resistance and toughness of acrylic resins. As a result of repeated efforts, the present invention was completed by solving the above problems by not simply mixing the aqueous polyurethane resin and the aqueous acrylic copolymer dispersion, but by functionally linking the two. reached.

That is, the present invention provides an aqueous urethane prepolymer obtained by neutralizing a urethane prepolymer obtained by reacting diisocyanes 1 to 1 with glycols containing carboxylic acid group-containing glycols and extending the chain with a hydrazine derivative. A radically polymerizable acrylic resin containing at least 0.5 parts by weight of a carbonyl group-containing monomer or an amide group-containing monomer based on 100 parts by weight of the total polymerizable monomers in the presence of the polyurethane resin (A). The present invention is an aqueous coating composition obtained by polymerizing polymer (B) and having a solid content weight ratio of (A)/(B) -10015 to 5/100.

The present invention will be described in detail below.

The aqueous polyurethane resin used in the present invention is produced, for example, as follows. That is, first, a diisocyanate, a glycol, and a glycol having a carboxylic acid group are subjected to a urethanization reaction to obtain a urethane prepolymer.

Diisocyanates used at this time include aliphatic, alicyclic or aromatic diisocyanates, examples of which include 2,4-tolylene diisocyanate, 2,4-tolylene diisocyanate,
．． 6-tolylene diisocyanate, 4.4°-diphenylmethane diisocyanate, ■-non-technical diisocyanate, xylylene diisocyanate, tel-ramethylene diisocyanate, lysine diisocyanate, 1,4
-cyclohexylene diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, 3,3"-dimethyl-4,4'-biphenylene diisocyanate, 3,
3°-dimethoxy-4,4″-biphenylene diisocyanate, 3,3′-dichloro-4,4°-biphenylene diisocyanate, 1,5-naphthalene diisocyanate, 1,5-te1-rahydronaphthalene diisocyanate, isophorone diisocyanate, etc. can be mentioned.

Glycols used in preparing urethane prepolymers include low molecular weight glycols, high molecular weight glycols,
Polyester polyols, polycarbonate polyols, etc. may be used alone, or, as is well known in urethane technology, low molecular weight glycols may be used in combination with polyester polyols and high molecular weight glycols.

Examples of low molecular weight glycols include ethylene glycol,
Diethylene glycol, 1 - diethylene glycol, 1
, 2-propylene glycol, 1,3-butylene glycol, tetramethylene glycol, hexamethylene glycol, deoxymethylene glycol, octanediol, tricyclodecane dimethylol, hydrogenated bisphenol A1 cyclohexane dimetatool, etc. Two or more types may be mixed.

Examples of high molecular weight glycols include polyethylene glycol, polypropylene glycol, polytetramethylene glycol, and the like.

The polyester polyols may be those obtained by reacting a glycol component and a dicarboxylic acid component, and can be easily produced by a known method. That is, the reaction is not limited to an esterification reaction, but may also be an ester exchange reaction. That is, the polyester polyol of the present invention can also be produced by transesterification using glycol and lower alkyl ester of dicarboxylic acid.

If the polyester polyol used in the present invention is one in which a glycol component and an unsaturated dicarboxylic acid are reacted, the functional bond with the radically polymerizable acrylic monomer will be stronger, and the resulting aqueous coating will be The agent composition becomes more preferable.

Examples of unsaturated dicarboxylic acids that can be used at this time include itaconic acid, maleic acid, and phthalic acid. Examples of other dicarboxylic acids include isophthalic acid, terephthalic acid, succinic acid, adipic acid, malonic acid, cepatic acid, and azelaic acid. Furthermore, lower alkyl esters of these dicarboxylic acids may also be mentioned. These dicarboxylic acids may be used alone or in combination.

Which glycols have carboxylic acid groups? , 2-
Dimethylolpropionic acid, 2,2-dimethylolacetic acid, ? , 2-dimethylolvaleric acid and the like.

The reaction involves dioxane, acetone, methyl ethyl ketone,
It is preferable to conduct the reaction in an organic solvent that is inert to isocyanate groups and has a high affinity for water, such as N-methylpyro-1-nodone or tetrahydrofuran.

Next, the prepolymer is neutralized and chain-extended, and distilled water is added to obtain an aqueous polyurethane resin.

The organic solvent used in the reaction may be removed by a known method if necessary.

Examples of the neutralizing agent include amines such as trimethylamine, triethylamine, tri-n-propylamine, tributylamine, and 1-heliethanolamine; sodium hydroxide, sodium hydroxide, and ammonia.

In the present invention, it is necessary to use a hydrazine derivative as a chain extender. Hydrazine derivatives include hydrazine, ethylene-1,2-dihydrazine, propylene-
Examples include 1,3-dihydrazine and butylene-1,4-dihydrazine.

Chain extenders for urethane prepolymers generally include polyols such as ethylene glycol and propylene glycol; ethylene diamine, propylene diamine, hexamethylene diamine, toridine diamine, xylylene diamine, diphenyl diamine, diaminodiphenylmethane, and diaminocyclohexylmethane. , piperazine, 2-
Aliphatic, cycloaliphatic and aromatic diamines such as methylpiperazine and isophorone diamine are well known, but in the present invention, such compounds can be combined with urethane resins when radically polymerizable acrylic monomers are emulsion polymerized. No effect was observed on the functional bonding of acrylic resin.

In other words, when chain elongation of the urethane prepolymer is carried out, it is necessary that the chemical structure of -NHNH2 is retained at the polymer molecule end of the aqueous polyurethane resin, and by retaining this chemical structure, For the first time, it can be functionally combined with the carbonyl group-containing monomer or amide group-containing monomer in the radically polymerizable acrylic monomer.

In the present invention, the acid value in the aqueous polyurethane resin is preferably 10 to 200 per resin solid content. If the acid value is less than 10, i.
In some cases, the storage stability of the obtained aqueous polyurethane resin may be poor. On the other hand, if the acid value exceeds 200, desirable physical properties such as durability and water resistance may not be obtained when the acrylic resin is functionally bound.

The radically polymerizable acrylic monomer used to obtain the aqueous coating composition of the present invention includes a carbonyl group-containing monomer or an amide group-containing monomer based on 100 parts by weight of the total radically polymerizable acrylic monomer. It is required that the content be at least 0.5 parts by weight, or conventionally known surfactants, protective "loids, and polymerization initiators used in emulsion polymerization can be used.

As the carbonyl group-containing monomer, aldo group or carbonyl group-containing monomer may be used.
It refers to a monomer containing a ~ group, and a nistyl bond (-
Compounds having only C-O-) or carboxyl groups (-C-01) are not included in this monomer.

Examples of carbonyl group-containing monomers applicable to the present invention include acrolein, diacetone acrylamide, vinyl toluene, vinyl acetate, vinyl butyl ketone, diaze 1 hene acrylate 1, acetonyl acrylate 1, etc. It will be done.

Examples of the amide group-containing monomer include monoolefinically unsaturated carboxylic acid amides, 11-alkyl derivatives of monoolefinically unsaturated carboxylic acid amides, and 1tl-alkylol derivatives of monoolefinically unsaturated carboxylic acid amides. . Examples of suitable monomers include amides of acrylic acid, methacrylic acid, itaconic acid or maleic acid: N-methylacrylamide, N-isobutylacrylamide, N-methylacrylamide, N-methylolacrylamide, N- Examples include methylolmethacrylamide, N-ethoxymethylacrylamide, Nn-butoxymethylacrylamide, toisobroboxymethacrylamide, and the like.

These carbonyl group-containing monomers or amide group-containing monomers may be used alone or in combination, but
At least 0.5 parts per 100 parts by weight of total polymerizable monomers
Parts by weight are necessary, and a particularly preferable range is 1.0 to 10
．． It is 0 parts by weight. When the amount is less than 0.5 parts by weight, the functional effects of water-based polyurethane resin and acrylic resin are observed, and significant improvements in physical properties such as weather resistance, water resistance, alkali resistance, elasticity, and abrasion resistance are observed. Hard to get.

Acrylic monomers other than those mentioned above that can be used in emulsion polymerization in the present invention include acrylic esters such as methyl acrylate, ethyl acrylate, butyl acrylate, and 2-ethylhexyl acrylate; methyl methacrylate, and methacrylate. Examples include methacrylic acid esters such as ethyl acid.

In the present invention, other polymerizable unsaturated monomers that can be copolymerized with the above-mentioned acrylic monomers can also be used.

Examples of such polymerizable unsaturated monomers include maleic acid,
Esters of fumaric acid and itaconic acid: vinyl acetate,
Vinyl esters such as vinyl propionate and vinyl tertiary carboxylate; Aromatic vinyl esters such as styrene and vinyltoluene; Heterocyclic vinyl compounds such as vinylpyrrolidone; Vinyl chloride, acrylonitriyl, vinyl ether, and vinyl ketone , vinylamide, etc.; halogenated vinylidene compounds such as vinylizone chloride and vinylidene fluoride; α-olefins such as ethylene and propylene;
Examples include dienes such as butadiene.

Examples of the polymerizable unsaturated monomer having a reactive polar group include glycidyl-based compounds such as glycidyl acrylate-1, glycidyl methacrylate, and allyl glycidyl ether; vinyltrichlorosilane, vinyltrichlorosilane,
Vinyltris(β-me]~xyethoxy)silane, γ-
Silane compounds such as methacryloxypropyl trime-1 hexysilane; acrylic acid, methacrylic acid, maleic acid or its half ester, fumaric acid or its half ester,
Carboxyl compounds such as itaconic acid or its half ester, crotonic acid; Hydroxyl compounds such as β-hydroxyethyl acrylate and β-hydroxyethyl methacrylate; -14= amine compounds such as alkylaminoacrylate and alkylaminomethacrylate. Can be mentioned.

In the present invention, in the presence of an aqueous polyurethane resin,
By emulsion polymerizing radically polymerizable acrylic monomers,
A surfactant (emulsifier) is not absolutely necessary, but it can serve as a reaction site for the aqueous polyurethane resin or the radically polymerizable acrylic monomer. ) monomer 10
(> parts by weight, and a surfactant (emulsifier) may be used in the range of 0 to 10 parts by weight. As the surfactant (emulsifier) at this time, conventionally known surfactants can be used.

Examples of surfactants include anionic emulsifiers such as sodium dodecylbenzene sulfate, sodium dodecylbenzene sulfonate, alkylar polyether sulfate, and the like;
Nonionic emulsifiers such as polyoxyethylene lauryl ester, polyoxyethylene nonylphenyl ether, polyoxyethylene-polyoxypropylene block copolymer, etc.; cedyl trimethyl ammonium bromide,
A cationic emulsifier such as laurylpyridinium chloride can be appropriately selected and used. In addition, it is also possible to use a water-soluble oligomer as a dispersant instead of the emulsifier as mentioned above, or by using an emulsifier (jf).Furthermore, water-soluble polymer substances such as polyvinyl alcohol, hydroxyethyl cellulose, etc. It is also effective to use the above-mentioned emulsifier together with the emulsifier, or to add it to the emulsion after polymerization.

The total amount of the emulsifier, water-soluble oligomer, and water-soluble polymer substance used is preferably in the range of 0 to 10 parts by weight based on 100 parts by weight of the radically polymerizable acrylic monomer. If the amount exceeds this range, the water resistance of the final aqueous coating composition may be significantly reduced, which is not preferable.

The radical polymerization initiator used in the emulsion polymerization to obtain the aqueous coating composition of the present invention may be one that is used in ordinary emulsion polymerization or may be used. Examples thereof include persulfuric acid and Examples include ammonium persulfate, azobisisobutyronitol and its hydrochloride, and organic peroxides such as cumene hydroperoxide and tert-butyl hydroperoxonoid may also be used as necessary. I can do it. Furthermore, these persulfates or peroxides and metal ions such as iron ions and sulfur helium sulfoxylate formaldehyde,
Known redox initiators that are used in combination with reducing agents such as sodium pyrosulfite and L-ascorbic acid may also be used.

From a practical standpoint, the concentration during emulsion polymerization is preferably such that the final composition has a solid content concentration of 25 to 65% by weight, and the concentration of ethylenically unsaturated monomers and radical polymerization in the reaction system is preferably 25 to 65% by weight. The initiator can be added by any known method such as batch charging, continuous dropwise addition, and divided addition.

The temperature during emulsion polymerization may be within a range that can be carried out in known emulsion polymerizations, and the emulsion polymerization is carried out under normal conditions or, when using a dregs-like ethylenically unsaturated monomer, under 1 hour.

In the present invention, a radically polymerizable acrylic monomer containing a carbonyl group or an amide group is subjected to emulsion polymerization in the presence of an aqueous polyurethane resin whose chain has been extended using a hydrazine derivative. , strong functional connections within and between particles are developed.

This bond is thought to be caused by an organic reaction between the chemical structure of the hydrazine group at the end of the polymer molecule of the water-based polyurethane resin and the carbonyl group or amide group in the acrylic polymer during dehydration.
This is an aqueous coating composition that organically combines the functions of a condensation resin and a radical polymerization resin.

Furthermore, the aqueous coating composition of the present invention not only has the characteristics of combining the elasticity and abrasion resistance of urethane resins with the weather resistance and toughness of acrylic resins, but also
The solvent resistance and other properties are also significantly improved compared to each resin alone. For example, a coating film obtained from an aqueous polyurethane resin is easily dissolved in ketones such as methyl ethyl ketone, and a coating film obtained from an acrylic emulsion synthesized without the aqueous polyurethane resin is -
18 = 1 ~ Easily dissolved in toluene, etc. However, aqueous coating compositions that meet the requirements of the present invention include methyl ethyl ketone,
Insoluble in both solvents, toluene.

On the other hand, water-based polyurethane resins lacking the requirements of the present invention
The acrylic resin composite has the elasticity of urethane resin,
The abrasion resistance, weather resistance and toughness of acrylic resin (
jf I can't help but be impatient. Regarding solvent resistance,
No compounding effect was observed, and it became easily soluble in both solvents.

The blending ratio of the water-based polyurethane resin and the radically polymerizable acrylic monomer is 10015 to 5 in solid weight ratio.
/100 is a requirement of the present invention, and 10
More preferably, it is in the range of 0/10 to 10/100. If this range is exceeded, it will be difficult to combine the characteristics of urethane resin and acrylic resin.
It is difficult to obtain a coating film with the characteristics described above. By adjusting the blending ratio of the aqueous polyurethane resin and the radically polymerizable acrylic monomer within the range of the present invention, the characteristics of the urethane resin or the characteristics of the acrylic resin can be emphasized.

The aqueous coating composition of the present invention can be produced in the same manner as conventional aqueous coating compositions using aqueous dispersions of Acjnor-based copolymers, and can be used in clears, pigments added, and paints. used as. That is, pigments, fillers, aggregates, dispersants, wetting agents, thickeners and/or rheology control agents, antifoaming agents, plasticizers, coalescence agents, organic solvents, preservatives,
Antifungal agents, pH adjusters, rust inhibitors, etc. are selected and combined according to their respective purposes, and are made into paints using normal methods.

The present invention will be explained in more detail with reference to Examples below.
The present invention is not limited only to the following examples.

In addition, in the following, both parts and % are values based on weight.

Production Example 1 Production of water-based polyurethane resin (A) 1.6-
By mixing 1,780 g of hexanediol, 2,545 q of adipic acid, and 567 g of 2,2-dimethylolpropionic acid, warming the mixture to 170'C, and reacting at this temperature for 23 hours, 08 valence 60. A boroester polyol with an acid value of 60 was obtained.

This polyester polyol was diluted by adding 1815 g of methyl ethyl ketone. This polyester polyol solution (King) 240, I and methyl ethyl ketone 2
20g? , 30 g of 2-dimethylolpropionic acid and 27 g of cyclohexane dimetatool were sufficiently stirred and mixed at 70°C, and then 236q of 4,4'-dicyclohexylmethane diincyanate was added and the temperature was raised to 80°C. After reacting for a period of time, the mixture was cooled to 30°C to obtain a urethane prepolymer solution.

This polyurethane prepolymer solution was prepared in advance at 21°C.
80% hydrazine aqueous solution and 1 heliethylamine 40Ω
Ω was gradually poured into an aqueous amine solution prepared by dissolving Ω in 1500 g of ion-exchanged water under high-speed stirring to obtain a viscous and translucent product. After removing the solvent at 55°C under reduced scale, ion exchange water was added to adjust the concentration, non-volatile content was 23.7%, viscosity (B) f viscometer, 60 ppm, 25
A translucent aqueous polyurethane resin (A-1) having a temperature of 23 cPs (°C) and a pH of 8.4 was obtained.

Using the above method and @J's method, using the raw materials shown in Table 1, water-based polyurethane resin (A
-2) was prepared.

(Margin below) -231 Examples 1-5, Comparative Examples 1-5 The following materials were prepared as raw materials.

■Radical polymerizable monomers (B) 2-ethylhexyl acrylate 265g styrene 165g acryloni-1-lyl 50g acrylic acid
10q diacetyl hene acrylamide
10Ω■Surfactants Newcol 707S Solid content 30%) Wood 1) 50Q
■Ion exchange water 360g■Polymerization initiator ammonium persulfate 2.5g*1) Nippon Nyukaza tA wooden, special anion emulsifier 4 Into the flask, add surfactant 30Ω, ion exchange water 210g, and aqueous polyurethane resin (A-1) 1054C1. Stirring was started, the temperature was raised to 80°C in a nitrogen stream, and then a polymerization initiator was added. Next, radically polymerizable monomers (
B) 500g, surfactant 20Q, ion exchange water 150g
g to prepare a monomer pre-emulsion, and this monomer pre-emulsion was dropped into the above flask over 3 hours. The reaction temperature at this time was 80±3°C
I kept it.

After completion of the dropwise addition, the reaction was continued under stirring while maintaining the same temperature range for 2 hours, and then cooled and adjusted to I) H8-9 with 14% ammonia water, with a non-volatile content of 380% and a viscosity of 2.
An aqueous coating composition (Example 1) having a pH of 8.00 cPs and a pH of 8.5 was obtained.

Furthermore, in the same manner as in Example 1, aqueous coating compositions (Examples 2 to 5, Comparative Examples 1 to 5) were obtained using the raw materials shown in Table 2. The results are shown in Table 2.

(Blank below) = 25- Comparative Example 6 Emulsion polymerization was carried out in the same manner as in Example 1, except that the aqueous polyurethane resin (A-1) was not used at all. , an acrylic emulsion was obtained.

This emulsion has a non-volatile content of 55.1% and a viscosity of 330.
0 cPs, pH 8.5.

Comparative Example 7 For a comparative experiment to evaluate the effect of acrylic polymer,
The aqueous polyurethane resin (A-1) was used as Comparative Example 7 as it was.

The aqueous coating composition thus obtained was tested for film properties without any additives added. Table 3 shows the results.

(Left below) -27= Test method (1) Water resistance; A sample was applied to a glass plate using a 3 mil applicator to create a film. After drying at room temperature for 3 days, the film was immersed in water.

After soaking at room temperature for 7 days, the film condition was visually judged.

(○...good, △...fair, ×...poor, the same applies hereafter) (2) Aluminum resistance: A film prepared in the same manner as in (1) was added to a 2% sodium hydroxide aqueous solution. After 7 days of immersion, the film condition was visually judged.

(3) Solvent resistance; a film prepared in the same manner as (1),
The film was immersed in toluene and methyl ethyl ketone for one day, and the film condition was visually determined.

(4) Abrasion resistance: JFPA standard test standard tiles (vinyl asbeth 1 to tile) per square meter of 1 heel, 1
Apply the sample so that the thickness is 0±2.

After drying a test piece coated five times in the same manner at room temperature for 7 days, the degree of wear was measured and evaluated using a Chihe tester (wearing wheel C3-17, load 1000 C; l).

(5) Film strength and elongation; pour the sample onto a glass plate,
It was used after drying for 7 days. The sample was taken so that the film thickness after drying was 0.2 mm.

(6) Flow start temperature: As a sample, a film dried on a glass plate for 7 days was used at a temperature of 1.5 to 2. OC] Use. Heating rate: 3°C/min, load: 30kgf, die: 1m
Measure the flow start temperature at mφX 1mm, f).

As can be seen from Test Results Table 3, the aqueous coating composition of the present invention has significantly better abrasion resistance, solvent resistance, film strength and elongation than other compositions that do not meet the requirements of the invention. become excellent. Furthermore, the flow start temperature is also significantly higher, indicating that there is a functional bond between the water-based urethane resin and the acrylic resin.

Using each of the aqueous coating compositions obtained according to the formulations shown in Table 2, the following coating formulations were carried out to prepare elastic coating agents.

(Composition) Type R-930 *6) 1o0.0 Old-Metrose 90SH-15000 *7) 0.6 Primal 850 *8 No. 1.05% with Ding P
P (to-1-polyphosphoric acid) 2.0 Noigun EA-12
0*9) 1.0 Adekanol 5X
-568*10) 2.5 ethylene glycol 10.0 water
35,228% ammonia water 1.0 Disperse the above formulation in a high speed disperser and add the following formulation.

39% emulsion of each aqueous coating composition) 391.0 Texanol 26.4 Xylene
6.6 Ade'kanol 11 N
-7120*12)/ho 1/2 (adjusted according to paint viscosity) total
! i77.3N, \l (%)
/13.7PVC (%)
15.2PWC (%)
39.6 persimmon) Ludil type titane oxide; Ishihara Sangyo Co., Ltd. *7) Methylcellulose: Shin-Etsu Chemical (
Ltd. *8) Polycarboxylic acid type dispersant; Rohm & Haas Rei (USA) *9) Surfactant: Daiichi Kogyo Seiyaki] *10) Antifoaming agent: Asahi Denka (1 Zhu *11) emulsion Adjusted by non-volatile content (%) *1
2) Thickener; Asahi Denka■ Examples 1 to 5 and Comparative Examples 1 to 7 using the above paint formulations
The applied physical properties of the aqueous coating composition were tested.

The results are not shown in Table-4.

(Left below) Test method Viscosity: BH type Paint viscosity (cps) at 4 rpm Coating film gloss: Coated on a glass plate with a 3 mil applicator, and measured 600 fouling rate after drying for one day (%).

JIS A6910: Elongation rate: A test piece was prepared so that the dry coating thickness was about 1 mm, and then cured according to the JIS elongation test method and punched out using a No. 2 dumbbell.

(Coating → Curing for 7 days → Curing for 7 days on the back side → Punching) Deterioration during elongation: The above specimen was punched out using a No. 1 dumbbell as a test piece.

Adhesion strength: Acrydic 53-4 as a primer
After drying for 3 hours, the sample was applied according to the test method, and after 14 days of curing, the four sides of the test specimen used to test the adhesion strength after being submerged in water were painted with vinyl chloride resin paint 3 days before the end of curing. It was crowded. The adhesive used was a two-component poxy adhesive.

Resistance to repeated heating and cooling: (18Hrs in 20±2°C water → -20±3°C x 3
Hrs-)50±3°CX3HrS)X1
0-! Nokle water permeability...Compliant with JIS elongation test method Impact resistance...
- Weather resistance... Coating film strength: Displays the coating film strength at the time of measuring the JIS A6910 elongation rate.

Accelerated weathering resistance: Measure the elongation of the coating at 20°C and -10°C after irradiating the same coating film for elongation measurement using a standard weather meter for 500 hours.

As can be seen from Test Results Table 4, the aqueous coating composition of the present invention has good weather resistance even when pigments are blended, and exhibits characteristics that the coating film strength does not deteriorate even after being immersed in water.

Representative patent attorney Chieko Tateno

Claims (1)

[Claims] (1) Water-based polyurethane resin (A ), a radically polymerizable acrylic monomer (B) containing at least 0.5 parts by weight of a carbonyl group-containing monomer or an amide group-containing monomer based on 100 parts by weight of the total polymerizable monomers.
obtained by polymerizing the solid content weight ratio of (A)/(B)=100/5 to 5/
100. An aqueous coating composition characterized in that: