JPH09324145A - Coating composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a coating composition having a more rapid curing performance and a more excellent luster than those of conventional compositions. SOLUTION: This coating composition comprises an anionically stabilized synthetic resin emulsion, a water-soluble or dispersible polymer formed from a monomer mixture containing an amino functional group-containing monomer in an amount of at least 20wt.%, a volatile base in an amount sufficient for raising the pH of the composition to a point at which all multifunctional amines are substantially are nonionic, an anionic pigment-dispersing agent neutralized with the volatile base, and a pigment. Therein, the coating composition contains PVC in an amount of <=30%, and has a total solid content concentration of 40-80wt.%.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a water-based paint which is excellent in quick-drying and initial water resistance, has high gloss, and has excellent manufacturing and storage stability and coating workability at room temperature or below, particularly at low temperature or high humidity. It relates to a composition.

[0002]

2. Description of the Related Art Conventionally, quick-drying water-based coating compositions have a high total solid content and a minimum amount of water-soluble components such as surfactants and thickeners, and a large amount of low boiling alcohol such as methanol. A method of speeding up the drying is known.
Further, those containing an emulsion polymer, a polyfunctional amine and a volatile base as described in JP-A-3-157463 have been known.

However, in the former method, the quick-drying property cannot be sufficiently enhanced, and performances such as coating workability and storage stability tend to be impaired. Also, when low boiling point alcohols such as methanol are added in an amount until the effect is exhibited,
I came into contact with the Fire Defense Law and the Industrial Safety and Health Law. In the latter method, the gloss is insufficient but the gloss is insufficient, and a coating composition having a quick-drying property and an excellent gloss has been desired.

[0004]

The present invention is excellent in gloss,
It is intended to provide a water-based coating composition which is excellent in quick-drying property, especially in low temperature and high humidity.

[0005]

SUMMARY OF THE INVENTION The present invention is an anionic synthetic resin emulsion, a water-soluble or water-dispersible polymer formed from a monomer mixture containing at least 20% by weight of amine functional group-containing monomers, essentially all of the various polymers. A coating composition comprising a volatile base in an amount sufficient to raise the pH of the composition to the point where the functional amine is in the nonionic state, the anionic pigment dispersant neutralized with the volatile base and the pigment. Thus, the present invention relates to a coating composition having a PVC content of 30% or less and a total solid content concentration of 40 to 80% by weight.

In the present specification, "quick-drying" refers to the property of drying more quickly than conventional compositions.
"Synthetic resin emulsion" used in this specification
By means is meant a water-insoluble polymer that can be prepared by conventional polymerization techniques such as emulsion polymerization. The synthetic resin emulsion forms a film under application conditions,
Polymerized from any monomer or mixture of monomers that produces a water insoluble polymer.

The synthetic resin emulsion used in the aqueous coating composition of the present invention needs to be anionically stabilized. They also mean water-insoluble polymers which can be prepared by conventional polymerization techniques such as emulsion polymerization. The present invention can also be practiced with more complex forms, for example polymers of core-shell particles.

The anionic character of the synthetic resin emulsion can be obtained by several methods, but the most general method is to use an anionic surfactant in the emulsion polymerization, or to use the anionic surfactant after the polymerization. Is added to the emulsion.

Nonionic surfactants can also be present in the synthetic resin emulsion during or after the polymerization of these anionically stabilized synthetic resin emulsions. Useful surfactants include: condensation products of naphthenic sulfonic acid with low molecular weight formaldehyde, carboxylic acid polymers and copolymers with a proper hydrophilic-lipophilic balance, higher alkyl sulphates such as sodium lauryl sulphate, dodecyl. Alkyl aryl sulfonates such as benzene sulfonate, sodium or potassium salts of isopropyl benzene sulfonic acid or isopropyl naphthalene sulfonic acid, sulfosuccinates such as sodium dioctyl sulfo succinate, alkali metal salts of higher alkyl sulfosuccinates such as octyl Sodium sulfosuccinate, sodium N-methyl-N-pummityl taurate (palmitoyltaura)
te), sodium oleyl isethionate, alkylaryl polyethoxyethanol sulphate or alkali metal salts of said sulphonic acid, such as sodium t-octylphenoxy-polyethoxyethanol sulphate having 1 to 5 oxyethylene units. There are various known anionic surfactants.

Another type of synthetic resin emulsion having anionic properties is the result of including a small amount of acidic groups in the polymer. Here, the acidic groups can be in salt form, for example alkali metal or ammonium salts. Examples of such acidic groups are incorporated initiator fragments, maleic acid, vinyl sulfonic acid,
It is derived from crotonic acid, acrylic acid, methacrylic acid, itaconic acid and the like.

A third useful type of synthetic resin emulsion having anionic character is a latex polymer containing neutralized basic monomers such as acrylamide, methacrylamide and the like. The anionic character of the synthetic resin emulsion may be more than one type.

The synthetic resin emulsion having an anionic property can be produced by a known method. Such a known method is disclosed by Wiley in 1975, D.W. C. Black Ray (DC Blackl
ey), "Emulsion Polymerization: Theory and Practice (Emulsion
Polymerization: Theory an
d Practice ”and InterScience Publishers (Interscience Publ)
F. Ishers) published in 1965. A. F. A. Bovey et al., "Emulsion Polymerization (Emuls
Ion Polymerization).

Synthetic resin emulsions are generally polymers or copolymers prepared, for example, from the following monomers: methyl acrylate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, decyl acrylate, methyl methacrylate. , Ethyl methacrylate,
Butyl methacrylate, styrene, butadiene, ethylene, vinyl acetate, "Versati (Versati
c) ”vinyl esters of acids (tertiary monocarboxylic acids of chain length C ₉ , C ₁₀ and C ₁₁ ) (the vinyl esters being“ vinyl versatates ”).
e))), vinyl chloride, vinyl pyridine, vinylidene chloride, acrylonitrile, chloroprene, acrylic acid, methacrylic acid, itaconic acid, maleic acid and fumaric acid, α, β-ethylenically unsaturated monomers and them. Polymers and copolymers of acrylic acid esters and methacrylic acid esters are preferred. They are "Emulsion Polymerization of Acrylic Monomers (Emulsio, published by Rohm and Haas Company, Philadelphia, PA, USA, May 1966.
n Polymerization of Acryl
ic Monomers) ”.

Copolymers using butyl acrylate, methyl methacrylate and 2-ethylhexyl acrylate as acrylic acid esters, acrylic acid and methacrylic acid as acrylic acid, and further using styrene are preferably used. The Tg of the synthetic resin emulsion is preferably in the range of 0 ° C to 70 ° C.

The coating composition of the present invention comprises a water-soluble or water-dispersible polymer formed from a monomer mixture containing at least 20% by weight of amine functional group-containing monomer.

Monomers containing amine functional groups include, for example: 1. The alkyl group may be linear or branched and has 2 to 3 carbon atoms, and the nitrogen atom may be a primary nitrogen atom, a secondary nitrogen atom or a tertiary nitrogen atom. Aminoalkyl vinyl ether or its sulfide (US Pat. No. 2,879,178).

Specific examples include: β-aminoethyl vinyl ether; β-aminoethyl vinyl sulfide; N-monomethyl-β-aminoethyl vinyl ether or its sulfide; N-monoethyl-β-aminoethyl vinyl ether or The same sulfide; N-monobutyl-β-aminoethyl vinyl ether or the same sulfide; and N-monomethyl-3-aminopropyl vinyl ether or the same sulfide.

2. Acrylamide or acrylic ester such as dimethylaminoethyl acrylate or methacrylate; β-aminoethyl acrylate or methacrylate; N-β-aminoethyl acrylamide or methacrylamide; N- (monomethylaminoethyl) -acrylamide or methacrylamide, etc. There is.

3. N-acryloxyalkyl-oxazolidine and N-acryloxyalkyltetrahydro-
1,3-Oxazines, and compounds corresponding to the above oxazolidines and oxazines, wherein the "alkyl" bond is substituted with alkoxyalkyl and poly (alkoxy-alkyl).

Examples of this compound are: oxazolidinyl ethyl methacrylate; oxazolidinyl ethyl acrylate; 3- (γ-methacryl-oxypropyl) -tetrahydro-1,3-oxazine; 3- ( β
-Methacryloxyethyl) -2,2-pentamethylene-oxazolidine; 3-β-methacryloxyethyl-
2-Methyl-2-propyloxazolidine; N-2-
(2-acryloxyethoxy) ethyl-oxazolidine; N-2- (2-methacryloxyethoxy) ethyl-oxazolidine; N-2- (2-methacryloxyethoxy) ethyl-5-methyl-oxazolidine; N-2
-(2-acryloxyethoxy) ethyl-5-methyl-
Oxazolidine; 3- [2- (2-methacryloxyethoxy) ethyl] -2,2pentamethylene-oxazolidine; 3- [2- (2-methacryloxyethoxy) ethyl] -2,2-dimethyl-oxazolidine; And 3-
[2- (2-methacryloxyethoxy) ethyl] -2
-Phenyl-oxazolidine.

4. Polymers of monomers that readily generate amines upon hydrolysis are useful as amine-containing components or to form polymers of amine-containing components of the binder composition. Examples of such monomers are such as acryloxy-ketimine and -aldimine.

Illustrative compounds are as follows: 2- [4-
(2,6-Dimethylheptylidene) -amino] -ethyl methacrylate; 3- [2- (4-methylpentyridine) -amino] -propyl methacrylate; β- (benzylideneamino-ethyl methacrylate; 3- [2-
(4-Methylpentylidene) -amino] -ethyl methacrylate; 2- [4- (2,6-Dimethylheptylidene) -amino] -ethyl acrylate; 12- (Cyclopentylidene-amino) -dodecyl methacrylate; N
-(1,3-Dimethylbutylidene) -2- (2-methacryloxyethoxy) -ethylamine; N- (benzylidene) -methacryloxyethoxyethylamine; N-
(1,3-Dimethylbutylidene) -2- (2-acryloxyethoxy) -ethylamine; and N- (benzylidene) -2- (2-acryloxyethoxy) ethylamine.

Generally, at least 20% by weight of the amine-containing polymer of the above-mentioned category 1, 2, 3 and 4 monomer is present in a neutral, alkaline or acidic aqueous medium, depending on the particular polymer sought. It can be obtained by solution polymerization. Generally speaking, this polymerization is carried out in an aqueous medium containing small amounts of organic or inorganic acids, such as acetic acid or hydrochloric acid. Amine-containing polymers are copolymers with up to 80% by weight of one or more monomers, such as methyl acrylate, acrylamide, methacrylamide and quaternary ammonium salts derived from amine monomers, such as 2-methacryloxyethyltrimethylammonium chloride. Includes. Small amounts of relatively insoluble comonomers can also be used to obtain water soluble polymers. The insoluble polymer may contain higher amounts of these comonomers. Such monomers include, for example, (C ₁
~ C ₁₈ ) Acrylic ester with alcohol and 1
Alcohols having 18 carbon atoms, especially (C ₁ -C
₄ ) Methacrylic acid ester with alkanol, styrene, vinyltoluene, vinyl acetate, vinyl chloride, vinylidene chloride, substituted styrene, butadiene, substituted butadiene, ethylene, and nitriles and amides of acrylic acid or methacrylic acid. The particular monomer or monomers used in making a given amine-containing polymer will depend on the proportion of amine-containing monomers used in making this copolymer. Preferably, comonomers having a relatively high solubility in water are used exclusively to prepare the water-soluble polymer. These polymers are therefore polymers and copolymers of cationic and optionally nonionic vinyl monomers. Examples of cationic monomers are amines, imines and quaternary ammonium salts; the other monomers mentioned are nonionic. Therefore, these water-soluble copolymers are free of traces of acid groups that may be present due to impurities in the monomers used or due to some hydrolysis that occurs during synthesis, storage or use. For example, it does not contain other acid groups.

The viscosity average molecular weight of the insoluble amine-containing polymer is from about 5,000 to about 100,000, and the range of about 15,000 to 90,000 is preferred. The molecular weight of the water soluble polymer can range over a wide range. Typically, the viscosity average molecular weight is from about 5,000 to about 30.
10,000, and from about 40,000 to about 100,
A range of 000 is preferred. The amount of amine-containing polymer ranges from about 0.1 to about 20% by weight of the total weight of the anionic synthetic resin emulsion and amine-containing polymer.

The amine-containing polymers are generally as generally known in the art, for example as taught in US Pat. No. 4,119,600,
Depending on the particular polymer sought, it can be obtained by solution polymerization in neutral, alkaline or acidic aqueous media. Generally speaking, this polymerization is carried out in an aqueous medium containing small amounts of organic or inorganic acids, such as acetic acid or hydrochloric acid. Amine-containing polymers include copolymers with up to 80% by weight of one or more monoethylenically unsaturated monomers such as methyl acrylate, acrylamide and methacrylamide. Small amounts of relatively insoluble comonomers can also be used to obtain water soluble polymers. The insoluble polymer may contain higher amounts of these comonomers. Such monomers include, by way of example, acrylic esters with (C ₁ -C ₁₈ ) alcohols and alcohols with ₁ to ₁₈ carbon atoms, especially methacrylic acid esters with (C ₁ -C ₄ ) alkanols. , Styrene, vinyltoluene, vinyl acetate, vinyl chloride, vinylidene chloride, substituted styrene,
There are butadienes, substituted butadienes, ethylene, and nitriles and amides of acrylic or methacrylic acid. The particular comonomer or comonomers used in making a given amine-containing polymer will depend on the proportion of amine-containing monomers used in making the copolymer. These polymers are therefore cationic,
And optionally polymers or copolymers of nonionic vinyl monomers. Examples of cationic monomers are amines and imines; the other monomers mentioned are nonionic. Therefore, these water-soluble copolymers may be derived from impurities in the monomers used, or from synthetic,
It contains no other acid groups except the traces of acid groups that may be present due to some hydrolysis that occurs during storage or use.

Anionic synthetic resin emulsion, a water-soluble or water-dispersible polymer formed from a monomer mixture containing at least 20% by weight of amine functional monomers.
Compositions containing a sufficient amount of a volatile base to raise the pH of the composition to the point that essentially all polyfunctional amines are in the non-ionic state, such as tradename E-2706.
(Made by Rohm and Haas) can be exemplified.

Volatile Base The coating composition of the present invention requires a volatile base. The type and amount of volatile base used is such that the PH of the composition is up to the point where the amine functionality of the amine-containing polymer is deionized (deprotonated), typically at least PH5,
It should preferably be sufficient to raise the pH to 7-9 so as to avoid interaction with the anionically stabilized synthetic resin emulsion and other anionic components in the fast-drying coating composition. I have to.

After application, the volatile base evaporates, lowering the PH of the composition. When the PH of the composition drops to the point where protonation of the amine functionality begins to occur, the amine functionality becomes cationic. This rapid drying is believed to be initiated by this conversion of the amine functionality to the cationic state in the presence of the anionically stabilized emulsion polymer, but the exact mechanism that produces this fast drying is It has not been established and, therefore, the inventor does not constrain its fast-drying property by the exact mechanics theory.

Suitable bases include, but are not limited to:
There are ammonia, morpholine, alkylamines, 2-dimethylaminoethanol, N-methylmonophorine, ethylenediamine and mixtures thereof, the preferred base being ammonia. The equivalent ratio of amine to acid in the synthetic resin emulsion is preferably amine / acid = 0.5 to 1.0.
It is.

The coating composition of the present invention contains a volatile base-neutralized anionic surfactant as a pigment dispersant. The amount of the surfactant added is an amount sufficient to disperse the pigment, and is generally 0.1% of the effective component of the pigment.
It is 2 to 1.0% by weight. Widely known are surfactants neutralized with metal salts such as sodium and potassium instead of volatile bases, but these are the pH of the coating composition after coating.
Of the amine functional group is delayed, resulting in impaired drying properties, which is not preferable.

As the anionic surfactant neutralized with a volatile base, trade name Orotan 901 (produced by Rohm and Haas Co.) and trade name Poise 532A (produced by Kao Co.)
Can be exemplified.

Preferably, the coating composition of the present invention contains 0.5 to 3.0% by weight of a higher fatty acid amide condensate type nonionic surfactant in the coating composition. The higher fatty acid amide condensate-based nonionic surfactant acts as a wetting agent, improves the storage stability and manufacturing stability of the paint, and has a high gloss (6
A 0 degree specular gloss of 85 or more and a 20 degree specular gloss of 60 or more are obtained, and the quick-drying property is not impaired. If the amount added is less than 0.5% by weight, there is no effect on storage stability,
If it is more than 3.0% by weight, the physical properties such as water resistance of the coating film are deteriorated. Further, when a polyethylene oxide condensation type nonionic surfactant such as higher alcohol condensate (polyethylene oxide / alkyl ether) or higher fatty acid condensate, which is widely used in this field, is used, quick drying property is poor. Become.

The coating composition of the present invention further contains a pigment. The pigments include the following. Titanium dioxide, calcium carbonate, and clay are used as white pigments, and iron oxide and known organic pigments can be used as coloring pigments. Further, there is no problem in using titanium dioxide alone or in combination with other inorganic or organic pigments.

The coating composition of the present invention has a pigment volume concentration (P
VC) is 30% or less, and the total solid content concentration is 40 to 80.
Must be wt%. Preferably PVC is 10
-25%, most preferably 15-22%, and the total solids concentration is preferably 50-65% by weight, most preferably 55-60% by weight. If the PVC is too high, the gloss will be impaired, and if it is too low, the hiding power will decrease. On the other hand, if the total solid content is too high, the workability is deteriorated and it becomes difficult to produce and apply the coating. If it is too low, the quick drying property and gloss cannot be obtained. The combined use with calcium carbonate is preferable to titanium dioxide alone in terms of quick drying. At this time, the mixing ratio of titanium dioxide and calcium carbonate was 9 by weight.
It is preferable to select from 5: 5 to 70:30.

The effects of the present invention are achieved when all of the above requirements are satisfied. However, the inclusion of a higher fatty acid amide condensate type nonionic surfactant, or the combined use of titanium dioxide and calcium carbonate as pigments is a means for obtaining further effects and is an absolute requirement. is not. In addition to the above, the coating composition of the present invention includes low-boiling alcohols, thickeners, viscosity modifiers, defoamers,
Conventional paint components such as preservatives, solvents, etc. can also be used.

The coating formulation is shown in Table 1.

[Table 1] Comparative Example 1 An example of coating with an anionic surfactant neutralized with a substance other than a volatile base. Comparative Example 2 Example of coating with a polymer not containing a polyfunctional amine. Comparative Example 3 An example in which a nonionic surfactant other than the higher fatty acid amide condensate type was used to form a paint.

In Table 1, Orotan 901 is an anionic surfactant neutralized with a volatile base manufactured by Rohm and Haas Company. Nopco Santo RFA is a volatile base neutralized anionic surfactant from San Nopco. Poise 532A is an anionic surfactant neutralized with a volatile base from Kao Corporation. Nopco Santo 44C is a sodium salt type anionic surfactant from San Nopco. Dehydran 1620 is a defoamer from Henkel. JR-600A is Tyca's titanium dioxide. Luminous is fine calcium carbonate from Maruo Calcium. E-2706 is the above-mentioned synthetic resin emulsion. Movinyl M75 is a synthetic resin emulsion containing no multifunctional amine from Hoechst Synthetics. Modicol N is a higher fatty acid amide condensate type nonionic surfactant manufactured by San Nopco. Emulgen L4
0S is a nonionic surfactant from Kao Corporation. Texanol is a film-forming aid from Eastman Kodak Company.
RM2020 is a viscosity modifier from Rohm and Haas.

The measurement results are shown in Table 2.

[Table 2]

Evaluation Method of Thickening with Time: 50
The sample was allowed to stand for 1 week in a constant temperature bath at ℃, and the change in viscosity was confirmed. The ⊚ mark in the evaluation column indicates that there is no abnormal thickening and the adjusted viscosity (25 p
The change is less than 10% with respect to s to 45 ps), and the ∘ mark shows a viscosity increase of 10 to 20% with respect to the adjusted viscosity, and
The mark had a viscosity increase of more than 20% with respect to the adjusted viscosity. Gloss measurement method: The adjusted paint was applied onto a glass plate using a 6 mil applicator and dried at room temperature for 1 week, and the reflectance was measured with a gloss meter at entrance angles of 60 degrees and 20 degrees. did. Evaluation of drying property: After the adjusted paint is left to stand in a thermostat / humidity bath at 5 ° C and 85% RH for 24 hours or more, an applicator of 6 mil is used. Was applied to and evaluated according to the following criteria. Finger touch, semi-curing, and curing / drying conformed to the evaluation method of JIS K5400. For water-resistant drying, the coating film was immersed in water for 30 minutes so that the coating film would not be washed away.

[0040]

EFFECTS OF THE INVENTION The coating composition of the invention of claim 1 of the present application has high gloss (76 or more at 60 degree specular gloss and 44 or more at 20 degree specular gloss) and is at room temperature (20 ° C.) or less. ,
In particular, it has excellent quick-drying properties under low temperature (up to 5 ° C) or high humidity (up to 85% RH) conditions, and there is no problem in manufacturing stability.
Good coating workability. Similarly, the coating composition according to the second aspect of the present invention has a higher gloss (85 or more at 60 degree specular gloss and 50 or more at 20 degree specular gloss), and has excellent storage stability. . Further, the coating composition of the invention of claim 3 is a composition which is more excellent in quick-drying property than the composition of claim 1.

Claims (3)

[Claims] 1. Anionic synthetic resin emulsion, a polymer formed from a monomer mixture containing at least 20% by weight of amine functional group-containing monomers, to the point that essentially all polyfunctional amines are in the nonionic state. Of P
A coating composition comprising a volatile base in an amount sufficient to increase H, an anionic pigment dispersant neutralized with the volatile base, and a pigment, wherein the PVC is 30% or less, and the total solid content concentration is Is 40 to 80% by weight, a coating composition. 2. The coating composition according to claim 1, further comprising a higher fatty acid amide condensate type nonionic surfactant. 3. The coating composition according to claim 1, wherein the pigment is titanium dioxide and calcium carbonate.