JPS60190476A - Aqueous baking coating compound composition of resin power dispersion type - Google Patents

Abstract

PURPOSE:The titled composition for steel plate, etc., storable for a short time, having improved storage stability, by blending a basic substance and a thermosetting resin of base neutralization type with resin powder containing no carboxyl group under heating in a molten state so that the powder is dispersed into them. CONSTITUTION:An aqueous mixture of (A) a basic substance and (B) a thermosetting resin of base neutralization type (e.g., one selected from alkyd type, polyester type, maleic oil type, maleic polyalkadiene type, and acrylic type) is blended with (C) resin powder containing no carboxyl group (e.g., thermosetting resin powder) in a weight ratio of solid content of the component B:C of 2:98-98:2 under heating in a molten state, and, if necessary, (D) a crosslinking reactive substance dissolved in an aqueous medium and/or blended with the component C in a molten state, to give the desired composition.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a resin powder dispersed water-based paint composition. More specifically, the present invention relates to a water-based coating composition containing Ijl fat powder dispersed therein, which can be produced in a short period of time and has excellent texture and storage stability.

Water-based baking paints, which are made by stably dissolving or dispersing thermosetting resins in water through neutralization treatment with basic substances such as amines, are conventionally known. The paint made by dispersing is the 7th grade of water-based baking paint.
It has a good balance between zero-strength and the thick film properties of the powder coating, eliminating the poor sagging properties that are a common drawback of curved paints, and maintaining the high pinhole properties of the latter. It is a paint with good paint workability. By the way, dispersion of resin powder in water-based paint in the production of darning resin powder dispersion type water-based firing (=1 paint) has the drawback that it takes a very long time when using the usual dispersion method. The storage stability of the paint produced by this method is also poor, and the resin powder tends to settle and agglomerate during storage.

As a result of intensive research in order to solve the problem described in L, the present inventors have found that if the melting temperature of the resin powder or a temperature of -1- higher than the melting temperature of the resin powder is applied during the dispersion treatment of the resin powder in the water-based coating 11. As a result of melting, the resin powder becomes more uniform and finer, increasing its dispersibility, and the resin of the water-based paint is adsorbed to the resin powder, acting like a protective colloid, resulting in a stable dispersion being obtained in a short period of time. This discovery led to the completion of the present invention.

That is, the gist of the present invention is to provide a basic substance (T), a basic substance (T), and a basic substance (T).
) Base-neutralized thermosetting resin (11) dissolved and dispersed in an aqueous medium by J'11, 1B fat powder (ill) having no carboxyl group, and if necessary the above (11)
) and/or a substance (IV) that crosslinks with (III)
), and the water JI of (I) and (11)
A resin powder characterized in that (Ill) is heated, melt-mixed and dispersed in I+III, and (IV) is dissolved in an aqueous medium and/or melt-mixed with (III). Existing in dispersion type water-based baking coating i, l el+bomono.

The base-neutralized thermosetting resin (II) in the present invention is dissolved or dispersed in an aqueous medium to form a stable aqueous resin varnish by neutralization treatment with a basic substance (T) according to a conventional method. For example, alkyd type, polyester type, maleated oil type, maleated polyalkadiene type, epoxy type, acrylic type, and urethane type can be mentioned.

Specifically, in the case of an alkyd type and a polyester type, a carboxyl group may be introduced in the reaction step of a polybasic acid and a polyhydric alcohol, and the carboxyl group may be dissolved/dispersed in water by neutralization. In the case of maleated oils, carboxyl groups are introduced by treating drying oils (e.g. linseed oil, castor oil, soybean oil, tung oil) with maleic anhydride, which is then dissolved or dispersed in water by neutralization. Anything you do is fine. For maleated polyalkanenes, examples include polybutadiene (e.g. 1,2-polybutadiene, 1,4-polybutanoene, 1,2- and 1,4-copolybutadiene), polyisoprene or polycyclopentadiene. For example, when the double bond is unsaturated with a 3-carboxylic acid (e.g. maleic anhydride, hymic anhydride,
A carboxyl group may be introduced by adding 7-maric acid or itaconic acid, and the carboxyl group may be dissolved or dispersed in water by neutralization thereof. In the epoxy system, there are various epoxy lj represented by the reaction of bisphenol A and epichlorohydrin (in addition to fats, various compounds having other epoxy groups, acidic groups (e.g. carboxyl groups,
It is a resin that has an epoxy skeleton and an acidic group obtained by reacting a polyfunctional polyester, alkyd, or acrylic compound or resin that has a sulfonic acid group or a phosphoric acid group. It may be one that can be dissolved and dispersed. In the case of acrylics, α, β-i; saturated carboxylic acids (e.g. diacrylic acid, methacrylic acid, cinnamic acid, crotonic acid, fumaric acid, citraconic acid, maleic anhydride) and acrylic esters (e.g. methyl ester, ethyl esters, propyl esters, butyl esters, hexyl esters, lauryl esters) and/or methacrylic esters (e.g. methyl esters, ethyl esters, propyl esters, butyl esters, hexyl esters, lauryl esters), as required. Any polymer may be used as long as it is obtained by polymerizing other polymerizable monomers and can be dissolved or dispersed in water by neutralizing the carboxyl group. In the urethane type, neuecyanate compounds (e.g. hexamethylene diisocyanate, tolylene diisocyanate, 4.4'-diphenylmethane diisocyanate, xylene diisocyanate), 4.4'-
methylene bis(cyclohexyl isocyanate), isophorone diisocyanate), etc., a polyfunctional polyester system having acidic groups (e.g. carboxyl group, sulfonic acid group, phosphoric acid group) and, if necessary, other functional groups (e.g. hydroxyl group), A resin having a urethane skeleton and an acidic group obtained by reacting with an alkyd-based compound, an acrylic-based compound, or a resin, and which is dissolved or dispersed in water by neutralization of the acidic group may be used.

The neutralization rate of resin (II) by the above neutralization treatment may be appropriately selected within a range that allows a stable aqueous resin varnish to be obtained, and may generally be 30 to 120%. In addition, the content of resin (It) in the obtained aqueous resin varnish is 5 = it
(1% per width is sufficient. For this water-based varnish, as with normal water-based baking paints, add a core material (m is water-soluble amyl fat, water-soluble 7 A crosslinking agent such as a 7-l resin may be added.

The basic substance (T) in the present invention is the above-mentioned 11 (fat (1)
Neutralize 1)! For example, lithium hydroxide, potassium hydroxide 2, sodium hydroxide 1, ammonia, monomethylamine, dimethylamine, trimethylamine, monomethylamine, diethylamine, triethylamine, monoisopropylamine, monoisopropylamine, etc. , triethylenetetramine, monoethanolamine, jetanolamine, )・liethanolamine, monoisopropaalamine, diisopropaalamine,
Dimethylethanolamine, diethylethanolamine, 2-amino-2-methylpropanol, 2-dimethylamino-2-methylpropatol, dimethylaminoethoxyethanol, morpholine, -methylmorpholine,
Examples include n-ethylmorpholine and piperanone. Among these, it is an organic basic compound with a boiling point of 40°C or higher.
1- Later is preferred. If the boiling point is too low, resin powder (III
) It volatilizes due to heating during dispersion, making it impossible to achieve the intended purpose.

The resin powder (Tll) in the present invention is a water-insoluble resin powder that does not have a carboxyl group and is solid at room temperature. The resin does not have a carboxyl group! It goes without saying that it does not have any functional group in view of the II content, but it also means that it may exist in a small amount to the extent that the properties of this functional group are not reflected in the properties of the resin.

Such ti1 fat is heated under the heating conditions (approximately 35 to It may be either thermosetting or thermoplastic as long as it has the property of melting at 95°C.

For example, thermosetting or thermoplastic acrylics, alkyds, thermosetting or thermoplastic polyesters, phenolics, amide/plasts, epoxies, 7-polyolefins, vinyl chloride, polyethers, polydienes, polystyrenes. Examples include thread and petroleum-based materials.

Among these resins, thermosetting resins are 1A, which has reactivity with the resin as required, as with ordinary powder coatings.
(A fat or a compound may be melt-mixed as the substance (IV). For example, in the case of a thermosetting acrylic system, depending on the type of functional No. Isocyanate or polycarboxylic acid may be selectively blended.

In the case of epoxy systems, crosslinking agents such as dicyandiamide, acid anhydride agct, BF3 complex, etc. may be blended. In addition, among these crosslinking agents, the above (k1 fat (
11) or its crosslinking agent may be omitted. Moreover, the reverse may be sufficient. In addition, for thermoplastic resins whose melting temperature is higher than the temperature of the heating conditions described in -, known plasticizers (e.g., heptalic acid derivatives such as butyl phthalate, tricresyl phosphate, etc.) may be used. It can be used by adding phosphoric acid derivatives to substantially lower the melting temperature.

The powder containing the resin and, if necessary, a crosslinking agent, a plasticizer, etc., may be produced in accordance with ordinary powder coatings. The size of the powder depends on the storage stability and coating workability of the intended coating composition,
Since it affects the appearance of the coating film, the thickness may be 3 to 60μ, preferably 5 to 25μ.

In addition, the combination of two types of resins (II) and (III) is
It may be selected as appropriate depending on the required performance for the formed coating film. Of course, two or more types of resins (II) and (III) may be used in combination based on the same viewpoint.

In the coating composition of the present invention, resin (II): (Ill
) may be blended in a solid weight ratio of 98:2 to 2:98, preferably 98:2 to 4.0:60.

If the amount of the latter (r+r) is too small, the painting work will be inferior;
On the other hand, if it is in excess, the 70-quality of the coating film will be poor. Preferably, when the ratio of the former (II) is 40 or more, the coating workability of the paint and the appearance and gloss of the coating film will be good.

The Kine-1 composition of the present invention is a system in which water (preferably deionized water) is used as a medium.
'l+Solution Wl (Example: ethylene glycol monoethyl ether, ethylene glycol monoethyl ether, ethylene glycol moabutyl ether, methanol, ethanol, isopropyl alcohol, 11-butyl alcohol, sec-butyl alcohol, 1-butyl alcohol, 2゛methylforno, amide) may be blended. In addition, as with ordinary paints, various pigments and additives (e.g. modifiers, powders, surface conditioners) may be blended as necessary. The agent may be incorporated into the aqueous medium or the resin (III) or both.

The coating 1°II 411 composition of the present invention is prepared by first treating resin (II) with a basic substance (1) according to a conventional method and dissolving and dispersing the resin in an aqueous medium to produce an aqueous 8 (fatty varnish). Next, the varnish and resin powder (III) are mixed by a conventional dispersion method (
For example, it can be produced by subjecting it to a partial mixing treatment in a laboratory mixer, sand grind mill, paint shaker) under the heating conditions described above for about 5 minutes to 1 hour. If the heating temperature is too low, it will take a long time for dispersion, and the storage stability of the manufactured paint will also be poor. IkekataIf the temperature is too high, the resin powder (I
II) Particle association and fusion occur, making it impossible to disperse particles with a desired particle size.

Alternatively, the desired coating composition may be produced by simultaneously mixing the basic substance (I), the resin (It), and the resin powder (III) into an aqueous medium and performing a heating dispersion treatment in the same manner as described above.

In addition, when producing a pigmented colored paint composition, a pigment paste is produced using a part of the water-based resin varnish according to a conventional method, and the remaining water-based resin varnish is used in the same manner as described above. Producing a mixed dispersion of resin powder (III),
Thereafter, the pigment pellet and mixed dispersion are mixed according to a conventional method, and if necessary, the crosslinking agent of the resin (11) is added to the substance (IV).
When blending as a compound, it is practical to mix the crosslinking agent last.

The coating composition of the present invention having the following configuration 11 has the advantages mentioned in -I- of the resin powder-dispersed water-based sintered coating (in other words, it enables the coating to be highly non-volatile and reduces the sagging film thickness limit. The value increases, and the foaming of the formed coating film decreases, and the pin film 1 (l limit value also increases, and the coating workability improves.
Not only can it be produced in a short time (1. ,
It is further refined. Therefore, by using a target coating product containing finely divided particles, the thickness of the formed coating film is improved by -1.

The coated 111-year-old article of the present invention may be subjected to painting according to conventional methods. For example, if necessary, dilute with water to an appropriate viscosity and apply air spray, airless spray, electrostatic coating,
Conventional coating methods such as roll coating, brush coating, and dip coating may be employed.1 Next, the present invention will be specifically explained with reference to Examples, Comparative Examples, and Reference Examples. Part means heavy part.

Example 1 (1) Production of aqueous resin varnish Butyl cellosolve solution of alkyd resin with acid value 55, hydroxyl value 80, number average molecule: *J100 (solid content 80 @ fine%)
I f'+ (in 1 part) methylethanolamide 12
- Add 25.8 parts and 150 parts of water and mix for 15 minutes at room temperature in a lab mixer to obtain a water resin varnish with a neutralization rate of 80%.

(2) Dispersion of resin powder in aqueous resin varnish, hydroxyl value 80,
Add 34 parts of polyester resin powder (size 5 to 50μ, amorphous) with an acid value of 3 and a melting temperature of 65°C to 70 parts of L water distributing resin varnish, and perform a dispersion treatment at 70°C for 15 minutes in a lab mixer. A mixture in which resin particles having a spherical shape and an average size of 3.7 μm (measured using CAPA500 manufactured by Horiba, Ltd.) are dispersed is obtained.

(3) Manufacture of pigment paste - Add 70 parts of rutin-type titanium oxide pigment to 70 parts of water-distributing resin varnish, and after pre-mixing, disperse the pigment paste in glass beads medium with conditioner for 400 minutes at room temperature. get.

(4) Manufacture of coating composition - 140 parts of the pigment base was added to 104 parts of the dispersion mixture obtained in (2), mixed in a lab mixer at room temperature for 15 minutes, and then water-soluble melamine resin (Hyoi Bundle 1)-
Add 2 ( ) parts of Old Cymel+ ((1: solid content 98% market weight) and further treat the portions for IO minutes until the viscosity is 7 f'l.
Ku (stormer, 25°C) coating composition:
).

In this coating composition, the solid content weight ratio of water-based cedar (alkyd resin of fat varnish: polyester + 31 fat powder) is 56:
-1,4.

Example 2 (1) Aqueous (b) production of fat varnish Same as Example 1.

(2) Dispersion of resin powder in aqueous (Jf fat varnish) Hydroxy value 5
0, Acrylic 134 fat powder (size 3
・-60μ, fixed size) 44 parts of the above water-based resin varnish 60
The mixture was then dispersed in a sand grind mill at 70° C. for 20 minutes to obtain a mixture in which spherical resin particles with an average size of 6.3 μm were dispersed.

(3) Production of pigment paste 1 Same as Example 1.

(4) Production of coating composition The dispersion mixture 1 obtained in (2) above was prepared in the same manner as in Example 1 except that 0 part was used, and the viscosity was 70 Kk.
A coating composition of 1 is obtained.

In this coating composition, the solid content weight ratio of the aqueous resin varnish to the alkyd resin and acrylic resin powder was 50:50.

Example 3 (1) Production of water-based resin varnish Acid value 60, hydroxyl value 50, number average molecule z39o.

6.3 parts of dimethylethanolamine and 150 parts of water were added to 100 parts of an ethyl cellosolve solution of acrylic resin (solid content: SO weight Z%) and mixed in the same manner as in Example 1 to obtain an aqueous solution with a neutralization rate of 80%. Obtain a resin varnish.

(2) Dispersion of resin powder into aqueous resin varnish 34 parts of the acrylic resin powder used in Example 2 was added to the above aqueous resin varnish.
0 parts, and was subjected to a dispersion treatment at 80° C. for 20 minutes in a lab mixer to obtain a mixture in which U (fat particles) were dispersed in a spherical shape with an average size of 1.2 μm.

=15- (3) Production of pigment base - 1 unit of pigment base was prepared in the same manner as in Example 1, except that 70 parts of 1 unit water distributing 11 fat varnish was used.

(4) Production of coating composition A coating composition with a viscosity of 75 Ku was prepared in the same manner as in Example 1, except that 114 parts of the dispersion mixture obtained in (2) above and 4.0 parts of the pigment pigment were used. 11).

In this coating composition, the solid content weight ratio of the aqueous 13 (fat varnish) acrylic resin powder is 56:44.
It is.

Example 4 (1) Production of Suiken fat varnish Acid value 33, hydroxyl value 35, number average molecular weight + 36 ('1
100 parts of isopropanol of polyester resin (solid content: 90% by weight) and 2 parts of dimethylethanolamine
．． 2 parts and 150 parts of water were added and mixed in the same manner as in Example 1 to obtain an aqueous resin varnish with a neutralization rate of 50%.

(2) Water-based? Polyester resin powder used in Example 1 (however = 16-), blocked isocyanate (Fleran L manufactured by Bayer AG)
JI) containing 20% by weight) was added to 80 parts of two-distribution resin varnish and dispersed in a lab mixer at 90°C for 20 minutes to form spherical resin particles with an average diameter of 6.8μ. A dispersed mixture is obtained.

(3) Production of pigment paste" Example 1 except that 70 parts of the dihydric resin containing alligator was used.
A pigment paste is obtained in the same manner.

(4) Production of coating composition A coating composition with a viscosity of 68 Kkl is obtained in the same manner as in Example 1 except that 110 parts of the dispersion mixture obtained in (2) above and 1 part of the pigment base) are used. .

In this coating composition, the solid weight ratio of polyester resin to polyester resin powder in the aqueous resin varnish is 60:4.
It is 0.

Example 5 (1) Aqueous O (Production of fat varnish) 100 parts of an ethyl cellosolve solution (solid content 70% by weight) of an acrylic resin with an acid value of 60 and a number average molecular weight of 9800, 5.2 parts of dimethylethylamine and 2 + 'l f1 part was added and treated in the same manner as in Example 1, resulting in a neutralization rate of 60.
% of aqueous Ih (to obtain a fat varnish.

(2) Water +11. Dispersion of resin powder in resin varnish Styrene-ethylhexyl acrylate copolymer (polymerization degree 500
, melting temperature 90 °C) powder (size 3 f) it,
, T: Regular shape) 20 parts 7 water distributing cedar (fat varnish 1 ()
In addition to 1 part of f', dispersion treatment was performed at 95°C for 200 minutes in a sand grind mill to form a sphere with an average size of 7.5μ.
11. The mixture in which the +jl fat particles are dispersed.

(3) Production of pigment paste - A pigment paste is obtained in the same manner as in Example 1, except that 150 parts of water-distributing TJ4 fat varnish is used.

(4) Production of coating composition 220 parts of pigment paste was added to 120 parts of the dispersion mixture obtained in (2) above, and the mixture was partially treated for 10 minutes at room temperature in a lab mixer to obtain a coating composition for old cars with a viscosity of 85. get.

In this coating composition, the solid weight ratio of aqueous 174-fat acrylic resin to styrene-ethylhexyl acrylate copolymer powder was 74:26.

Example 6 (1) Production of aqueous (31 fatty acids) acid value 95, number average molecular weight 1120 (ethyl cellosolve solution (solid content 80% by weight) of maleated polybutadiene resin of 1) 10 (1 part dimethylethanolamine 7.2
and 150 parts of water to obtain an aqueous resin varnish with a neutralization rate of 80%.

(2) Dispersion of resin powder in water-based resin varnish 30 parts of the polyester resin powder used in Example 4 was added to 70 parts of water-distributing resin varnish, and dispersed at 90°C for 15 minutes in a lab mixer. A mixture is obtained in which spherical resin particles having an average size of 3.8 μm are dispersed.

(3) Production of pigment paste A pigment paste is obtained in the same manner as in Example 1 except that 70 parts of the above water-based resin varnish is used.

(4) Production of coating composition 100 parts of the dispersion mixture obtained in (2) above and pigment = 19
A coating composition with a viscosity of 8(') Ku is obtained in the same manner as in Example 1, except that 14 r) parts of 14 r) parts of 14 r) of 100% of the total amount of 14 r) of the viscosity of 8(') Ku are used.

In this coating composition, the solid content weight ratio of aqueous O(fat varnish + maleated polybutadiene + 64 fat:polyester resin powder) was 56:44.

Example 7 0 (As a fat powder, polyethylene resin (7
0-sen LJ F, melting temperature 1 (-15°C) 1 part of tricresyl phosphate was melted and kneaded with 29 parts (1) except that 30 parts of powder (size 5 to 50μ, amorphous) was used. , Coating *'11 composition was applied for 1μ in the same manner as in Example 6. The dispersed resin particles were almost spherical and had an average weight of 9μ, the viscosity of the coating composition was 80Ku, and the maleated polybutadiene resin was a solid polyethylene resin powder. The weight ratio is 56:4'l.

Comparative Examples 1 to 7 Coating compositions were obtained in the same manner as in Examples 1 to 7, except that the resin powder was dispersed in the aqueous resin varnish at room temperature for the time shown in Table 1.

Reference Example 1 20-1 The coating compositions obtained in each of the above Examples and Comparative Examples were
Its stability was tested by storing it at 0°C for 10 days. The results are shown in Table 1. Furthermore, the coating workability (limit of pin film thickness, limit of sagging film thickness) and gloss of the formed coating film on a satin steel plate of each coating composition were evaluated, and the results shown in Table 1 were obtained.

In addition, the coating *) stability in the table is -23- Table 1 Patent applicant: Nippon Paint Co., Ltd. Representatives: Patent attorney 111, Haga 1 person, 24-

Claims (1)

[Claims] 1. A basic substance (N), a base-neutralized thermosetting 184 resin (I
I), 131 fat powder without carboxyl group (Ill
) and, if necessary, the above (II) and/or (11)
It is a system consisting of a substance ()V) that crosslinks with (1), in which (III) is heated and melted and dispersed in an aqueous mixture of (N and (10), and (1v) A resin powder-dispersed water-based baking coating composition characterized in that it is dissolved in an aqueous medium and/or melt-mixed with (III).2.The solid weight ratio of (II):(III) is 2. :9
8-98:2 is the introduction of the precepts in the first section of 1-ki. 3. The composition according to item 1, wherein (l I ) is selected from alkyds, polyesters, maleated oils, maleated polyalkanoenes, and acrylics. 4. The composition of Item 2 @ Item 1, in which DI (DI) is a thermosetting resin powder or a thermoplastic resin powder.