JPS6176560A - Water-soluble coating composition and coating film formation - Google Patents

Abstract

PURPOSE:The titled composition that contains a water-soluble coating resin, solvents and mountain wood, thus giving coating films with good drying properties, luster, hardness, acid resistance, alkali resistance, further water resistance and water-resistant adhesion. CONSTITUTION:The objective composition contains (A) a water-soluble coating resin, (B) a solvent and (C) 0.5-50pts.wt. based on component A, of mountain wood which is made into fibers and uniformly dispersed in amorphous three- dimensional directions. The mountain wood has preferably 0.002-0.1mu diameter in fibrous state. The resultant composition is coated on a substrate, baked at 60-180 deg.C for 10-60min to reduce the water content in the coating film to less than 5wt% after curing and drying.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a water-soluble paint composition in which a baking-type water-soluble paint and an acid-curing water-soluble paint, which are a type of water-based paint, contain mountain skin, and a method for forming a coating film thereof. be.

(Prior art and its problems) To prevent metal corrosion and give a beautiful appearance to the metal surfaces of automobiles, electrical equipment, and their parts.

It has been painted. Water-based paint is a type of paint for painting.

Water-based paint is the general name for water-soluble paint) and is made using water-soluble or water-dispersible film-forming elements (JI8
Paint terminology [5500-1068L This water-based paint is broadly classified into powdered water-based paint, synthetic resin emulsion, paint, baking type water-soluble paint, and acid-curing type water-soluble paint.

In other words, when it is painted, there are wrinkles, blisters, etc. on the coating film.
It has the advantage of having fewer defects such as pinholes and sagging that occur between the time of painting and drying, and also has the advantage of excellent gloss.

But water soluble? Depending on the object, the coating obtained by baking 4' cloth has low water resistance and water resistant adhesion, and has a short coating life.

Among these, various attempts have been made to solve y='A, a. One of the concrete methods is to add strontium chromate to the paint to make the surface of the object to be coated M'-free.
There is a way to make it +9. However, this method has the drawback of using strontium chromate, which poses problems in terms of environmental hygiene. As another solution,
There is also a method (JP-A-57-21462) in which an amino resin is used in combination with a resin containing a small amount of a hydrophilic component. However, the water resistance and water adhesion of the bulk film obtained by applying and baking the water-soluble paint obtained by this method still do not satisfy market demands.

In order to solve the above-mentioned problems of the prior art, the inventors of the present invention conducted extensive research and as a result, they came up with the present invention.

The object of the present invention is the conventional advantages of water-soluble paints. Water-soluble coating compositions that not only re-maintain dryness, gloss, hardness, acid resistance, 1Itit alkali properties, etc., but also have improved water resistance and water-resistant adhesion, and the use of water-soluble coating compositions based on these compositions. An object of the present invention is to provide a coating film forming method.

(Structure and operation of the present invention) The '1st invention (hereinafter referred to as the first invention) in the present application is:
It is a water-soluble paint composition mainly composed of a water-soluble m@ resin, a solvent, and a mountain coat, and contains 0.5 to 50 parts by weight of a mountain coat per 100 parts by weight of the water-soluble paint resin. The water-soluble method is characterized in that mountain bark is made into a fiber state and uniformly dispersed in an amorphous three-dimensional direction. This is a method for forming a coating film of a water-soluble coating composition, characterized by comprising a coating step of adding an appropriate amount of solvent to the resin and then reducing the weight of the O coating film to 0.5% or less.

First, the first invention will be explained.

The water-soluble coating resin in the first invention is made of an alkyd resin, an acrylic resin, an epoxy ester resin, an oil-free alkyd resin, and an amino resin as a curing agent.

In addition, the mountain bark used in the present invention is a magnesium-containing clay mineral, which has a highly reactive hydroxyl group on its surface, and specifically, sepiolite (5epiolite) whose main component is hydrated magnesium silicate.
+ Attapulgite whose main component is hydrated magnesium aluminum silicate
and one or more of these are used.

The mountain bark in the present invention is commonly referred to as mountain cork (Mou
ntain cork), mountain leather (Moun
tainleather), mountain wood (Δ
Fountain wood is a mineral that is also called 91 Meerschaum in Japan is also one of these minerals. The magnesium-containing clay mineral itself has the property of absorbing a large amount of water.

The crystals of the above-mentioned clay mineral are aggregates of long fibers 7) having a quadrilateral cross section of approximately Q17zm on one side, and the aggregates contain 0.00
It has a length of about 2 to 0.1 m and a length of about 0.1 to several 11 m, and is uniformly dispersed in an irregular three-dimensional direction in the water-soluble paint resin.

Mountain bark is usually mined from a mine and crushed using a crusher or other conventional methods.
The particles are 5 to 200 μm in size. That is, the fibrous mountain bark according to the present invention has a fiber shape that is different from the conventional mountain bark particles, which are finer and have a large slenderness ratio.

The mixing amount of the fibrous mountain bark and resin is 0.5 to 50 parts by weight of the mountain bark per 100 parts by weight of the water-soluble paint composition, and within this range, the advantages of the water-soluble paint can be maximized. The blot resistance and water-resistant adhesion of the resulting coating film to the metal plate are improved without any damage. In order to obtain even better effects, the amount of mountain bark mixed is most preferably 3 to 20 parts by weight.

If the amount of mountain bark mixed is less than 0.5 parts by weight, the effect of water resistance and water resistant adhesion to the coating film will not be obtained;
If the amount exceeds 1 part by weight, the viscosity of the water-soluble paint composition will become too high, and painting workability will decrease! After application, the resulting paint film is baked and loses its luster, ruining its aesthetic appearance.

The water-soluble coating composition in the first invention may contain pigments and additives. As a pigment.

Inorganic pigments such as carbon black, Ben Gaff, titanium white, etc.
Phthalosyaene. Organic pigments such as quinacridone and extender pigments such as calcium carbonate, talc, clay, magnesium carbonate, barium sulfate, etc. can be used. As additives, a dryer, an antifoaming agent, a leveling agent, an anti-color separation agent, etc. can be used as appropriate.

In addition to water, butylcellosolve, ethylcellosolve, isopropyl alcohol, butylcarpitol, and the like can be used as the solvent.

In this case, fibrous mountain bark containing pigments and additives is uniformly dispersed in an amorphous three-dimensional direction in the tree manure, and the viscosity of these is adjusted by the above-mentioned solvent to be suitable for painting work.

The water-soluble coating composition according to the first invention is applied to the surface of an object to be coated by a well-known coating method, such as electrostatic coating, air spray coating, dip coating, etc., and is dried to form a coating film. FIG. 1 shows the results of applying the paint obtained according to the present invention to a test plate and observing the O coating film using a transmission electron microscope. In the figure, it can be seen that ρ indicates that the fibrous mountain skin 1 is uniformly dispersed in an amorphous three-dimensional direction.

Next, the second invention will be explained.

The second invention is a method for forming a coating film using the water-soluble coating composition of the first invention.

In the crushing and mixing step in the second invention, a water-soluble paint resin is first prepared, and a
Mountain bark is added to the resin in the proportion of parts by weight, and the mountain bark is loosened in the presence of the resin to form a fiber, which is then dispersed in the resin. At this time.

Add an appropriate amount of solvent to the resin so that the resin content is 15% in the resin solution.
It is desirable that it be 65%. The mountain bark to be added to the 'C7J fat for water-soluble paints may be ground by a conventional method, and its particle size may be about 0.5 to 2007 zm. 0.577
It may be less than m or more than 2 0 Q /Zm, but if one particle is large, the workability in the crushing and mixing step will be poor and a long time will be required.

Normally, the water-soluble paint resin and the mountain bark are mixed with each other.
<1 It is difficult to uniformly disperse mountain bark using normal mixing methods.

Therefore, the crushing and mixing in one step is a method of dispersing by so-called rheological mixing, in which shearing force is applied to the mixture of resin and mountain bark. This crushing and mixing can be carried out using a dispersing machine such as a sand grinder, paint shaker, or Paul Mill. As an example, if you use a sand grinder, the volume is 11!
Glass peas with a diameter of 1 cod in a container with a closest packing ratio of 45 ~
55%, then add mountain bark, resin, and activating agent if necessary; rotate the disk set in the container at a speed of 6 per rotation.
m/see or higher (i.e., the shear rate is 3 m/see or higher)
It is best to crush and mix by rotating at a speed higher than 1000 ml (sea or higher). The fibers do not form into a fiber state, and some portions are not dispersed.

Add a solvent and, if necessary, a pigment to the mountain bark dispersion resin, which is made by turning the mountain bark into a fiber state and uniformly dispersing it.
Even if a coating film is obtained by baking for ~60 minutes, the water content in the dried coating film must be 5% or less of the weight of the coating film. If the temperature is less than 60°C, the coating film will not dry sufficiently, and the moisture adsorbed on the mountain skin will not be sufficiently removed. If it exceeds 180°C, the temperature is too high and the water evaporates rapidly, causing the paint film to become rough. If the drying time is less than 10 minutes, the temperature must be increased and the coating will become rough. Also, drying becomes uneven. If the drying time exceeds 180 minutes, workability decreases and the resin hardens before the moisture adsorbed on the mountain bark is sufficiently removed, which is disadvantageous.

If the moisture content in the paint film after curing and drying of the water-soluble paint composition is 5% or more of the weight of the paint film after curing and drying, the mountain skin absorbs some of the water remaining in the paint film. Even if it is adsorbed and newly penetrates into the coating film from the outside of the φ film, the desired effects of the present invention, such as water resistance and water resistant adhesion, cannot be expected.

The water-soluble coating composition of the present invention can also be used by appropriately mixing it with a colloidal emulsion layer coating or an emulgene coating. In addition, when mountain bark is added to the resin solution for colloidal emulsion μ-gin paints or the resin solution for emulsion paints, the particles of the resin for fiber paints and the resin for emulsion paints will fuse together, resulting in gelation. . Therefore, it is advisable to directly incorporate the scallops into the resin solution for colloidal emulsion paints or the resin solution for emulsion paints to form the fibrous fibrous material and uniformly disperse it in an amorphous three-dimensional direction. Therefore, by mixing a water-soluble paint composition in which the mountain bark is made into fibers and uniformly dispersed in an amorphous three-dimensional direction, and a colloidal emulsion paint composition, each paint composition is prepared.
It can also be used as an intermediate type coating composition.

(Effects of the Invention) The water-soluble coating composition according to the first invention exhibits appropriate thixotropy and has good coating workability because the fibrous skin is uniformly dispersed. Furthermore, in the dried coating film obtained from the composition, the mountain skin becomes fibrous and is dispersed in an amorphous three-dimensional direction.

Has water-repellent properties and water-resistant adhesion. That is, the coating film will not peel off from the object to be coated even if it is immersed in water for a long period of time, and it will not peel off even if a certain amount of force is applied.

In addition, the water content in the paint film after curing and drying absorbs moisture that enters the paint film, prevents moisture from reaching the interface between the coated object and the paint film, and improves water resistance. , exhibits excellent effects on water-resistant adhesion.

(Example) Examples will be described below.

First, each example was tested. The following is a method for confirming the water resistance and water resistant adhesion of a coating film.

That is, the size of the plate to be painted is 150ff x 7011f.

It is a mild steel plate (8PCD) with a thickness of 0.8 nm, and its surface is degreased with an organic solvent before painting. After coating these to form a coating film, they were immersed in pure water at 40°C, and the time in which blisters were generated was determined, and this was used as a criterion for water resistance judgment.

Water-resistant adhesion is determined by soaking the coating film in replenishing water at 40"C for 240 hours, then making 11 cuts in the coating film at 14 intervals vertically and 11 in each direction, making 100 squares on each side. Then, cellophane tape was directly pasted on the squares, and then the cellophane tape was peeled off at a constant speed from the end of the cellophane tape, and the number of squares that remained without being peeled off was counted. The more squares remaining, the better the water-resistant adhesion.

To explain in detail the manufacturing method of the water-soluble paint adopted in the examples of the present invention, we have adopted and reproduced the typical manufacturing method of the water-soluble paint currently on the market. I purchased a commercially available resin and selected it to see the effect of placing mountain bark on it.

Example 1 43.90 parts of safflower oil was placed in a Sdenless whip reaction vessel equipped with a flow cooler, a thermometer, and heating equipment, heated to 150°C, and 16 parts of trimethylo-I repropane was added.
After adding 44 parts by weight and increasing the temperature to 220°C,
Further, 0.02 parts by weight of Resurge was added to react.

Nine reactions were continued at this temperature until 1 part by weight of the product obtained was dissolved in 15 parts by weight of methanol/I. After the reaction was completed, the product was cooled to 166°C, and the bunalcarbito/
L'12.54 Market weight part Kinnae The mixture was stirred until uniformly dispersed. The reaction mixture to which 23.60 parts by weight of gold was added was again heated to 166°C and held at this temperature for 20 minutes, and then further heated to 190°C for 4 hours to react. When the acid value of the reaction product reached 55, the temperature was lowered to 170°C, and 6.5 parts by weight of phthalic anhydride was added thereto, and the reaction was continued until the acid value reached 45. 100 parts by weight of the obtained reaction product, 55 parts by weight of pure water, isoglopi
Diluted with a mixture of 6 parts by weight of alcohol/L/5 parts by weight of 28% aqueous ammonia and a resin bath for water-soluble paints 8! I got it. The water-soluble paint resin content was 60%, the viscosity (Gardner) was Z4°PR was 8.

100 parts by weight of this obtained resin and methylated methylo-μmehumine resin (Sumimar pM 40W,
Sumitomo Chemical Co., Ltd., non-volatile content: 80%) per 10 parts by weight of mountain bark with a particle size of approximately 0.1 to 150/Z m.
0 parts by weight were added and mixed using a sand grinder which is a dispersion machine. Then, a mountain bark dispersion resin was obtained. The sand grinder used had a capacity of 1 g, and had a diameter of 80 f during sanding.
Six pieces of Dinuk of 1 mm were loaded, and glass beads of 1 mm in diameter were placed so that the closest packing ratio was 50%. The mixing was carried out for 2 hours at a disk peripheral speed of 4 In/SeG. After the start of dispersion, immediately add 4 parts by weight of carbon black as a pigment, 6 parts by weight of calcium carbonate, 0.5 parts by weight of an antifoaming agent, and 40 parts by weight of Ingropil alcohol/I to 1 part by weight of resin content. and 29 parts by weight of pure water were sequentially mixed in to obtain a water-soluble coating composition according to the first invention.

This water-soluble coating composition contains fibers with a diameter of 0.
．． 002 to 0.1'tl'' + a large number of mountain skins with lengths of 01 to several 1 tm were uniformly dispersed in an amorphous three-dimensional direction.

Next, the coating composition was applied to a plate to be coated by air spraying, and after drying, water resistance and water resistant adhesion were investigated. The results are shown in the Example 1 column of Table 1.
Cold film hardness (JIS K5400) As shown in Figure 1, the mountain skin was in the form of fibers and dispersed in an amorphous three-dimensional direction.

Furthermore, 100 parts by weight of the same water-soluble paint resin was investigated. The results are shown in Examples 2 to 10 in Table 1. In addition, as comparative examples, we also investigated motsu to which 60 parts by weight of mountain bark was added and motsu to which no mountain bark was added.

The results are shown in Comparative Examples 1 and 2.

In addition, the above-mentioned mixing using the sand grinder was carried out for 30 minutes, and otherwise the dispersion was carried out in the same manner as in Example 1, to obtain a water-soluble coating composition in which the mountain bark remained granular without turning it into a fiber state. The water resistance and water resistant adhesion of the coating film obtained by baking after application were investigated. The results are shown in Table 1 for comparative meetings.

As is clear from Table 1, the two books of the present invention have significantly improved water resistance and water resistant adhesion compared to Comparative Examples 2 and 3.

In addition, a composition in which 60 parts by weight of mountain bark was added to 100 parts by weight of water-soluble paint resin and mixed rheologically (Comparative Example 1) was effective as a result of water resistance and water resistant adhesion tests. The appearance of the coating was poor, and the gloss test result was 35, making it inferior to conventional coatings and unable to meet the needs of the market.

Furthermore, water-soluble paint resin! Considering the hardness and gloss of the coating film, based on the test results of the examples in which the amount of mountain bark was added at approximately equal intervals from 0.5 parts by weight to 50 parts by weight to 100 parts by weight, The most preferable range of the amount of mountain bark mixed is 3 to 20 parts by weight.

In addition, the results of Comparative Example 3 show that even if the coating is added, which is said to be more effective, due to differences in the process and mixing technology, the coating may be irregularly shaped. This indicates that the effect of water resistance and water resistant adhesion was not achieved because the dispersion was not uniform in the three-dimensional direction.The reason for this is that the mixing process of the water-soluble paint resin solution and the mountain bark was delayed due to the mixing time. This is because it was short.

FIG. 2 shows the results of transmission electron microscope observation of the coating film.

This result shows that the particulate mountain skin 2 is dispersed almost as it is. In other words, this indicates that the mountain bark in the water-soluble coating composition must be in the form of fibers and uniformly dispersed.

Example 11 3.55 parts by weight of acrylic acid and 7.53 parts by weight of N-methylolacrylamide were placed in a galanu-lined reaction vessel equipped with a stirrer, a reflux condenser, and a heating facility.

Ethyl acrylate A/16.6 parts by weight, Methyl methacrylate IL' 16.6 parts by weight, I'/7''0 pi/L/7A/
:I-A155.5 parts by weight, peroxidation power ~0.2
Add 2 parts by weight.

Heated under reflux for 16 hours. Thereafter, 230 parts by weight of pure water and 10 parts by weight of 28% aqueous ammonia were added.

A water-soluble paint resin solution was obtained. The non-volatile content is 30% viscosity (
Gardner) was V-W, PR was 8.8. The resin content of the obtained resin solution was 100 parts by weight, and a methylated methylo-p melamine resin (sujimer) v M4 was added as a curing agent.
0 W e Mixing was performed using a sand grinder of a Sumitomo Chemical Co., Ltd. dispersing machine. Then, a mountain bark dispersion resin was obtained. The sand grain 1 yoke used had a volume of 4 ILL, in which three disks with a diameter of 80 mm were mounted, and gaff beads with a diameter of 1 N were placed so that the closest packing ratio was 50%. The mixing was carried out for 2.5 hours at a disk circumferential speed of 4 m/see. After the start of dispersion, immediately add 4 parts by weight of carbon black as a pigment, 6 parts by weight of μsium carbonate, 0.5 parts by weight of an antifoaming agent, 40 parts by weight of isopropyl alcohol-1v, and A water-soluble coating composition according to the present application was obtained by sequentially mixing 29 parts by weight of pure water.

This water-soluble coating composition contains fibers with a diameter of 0.
0.002 to 0.1 pn1, and a large number of mountain skins having a length of 0.1 to several μm were uniformly dispersed in an amorphous three-dimensional direction.

Next, the coating composition was applied to a plate to be coated by air spray, and after drying, water resistance and water adhesion were investigated. The results are shown in the column of Example 11 in Table 2 for baking under drying conditions, coating film hardness (JIS K5400), and baking using a coating film testing device (ADP-341, manufactured by Kyoto Electronics Industry Co., Ltd.) with various drying conditions. ) equipped with a Karl Fischer moisture meter (manufactured by Kyoto Denshi Kogyo Co., Ltd.).

Example 14 46.5 parts by weight of pure water, 0.0425 parts by weight of sodium bisulfite, and 0.0 parts by weight of sodium lauryl sulfate were placed in a stainless steel reaction vessel equipped with a stirrer, reflux condenser, and heating equipment.
0A 25 parts by weight were added and heated to 180°C, followed by 23.4 parts by weight of styrene, 2.12 parts by weight of methacrylic acid, and 170 parts by weight of ethyl acrylic acid.

0.17 parts by weight of potassium persulfate and 7.45 parts by weight of pure water were sequentially added dropwise and mixed. The mixture was heated to 66°C for 50 minutes, and the reaction was continued at 65-66°C for an additional 2.5 hours to obtain an emulsion paint resin solution. The obtained emulsion
3 parts by weight of carbon black, 4.5 parts by weight of calcium carbonate,
0.7 parts by weight of an antifoaming agent and butyl cellosolve were sequentially blended to obtain emulsion paint Rinrinrin.

Example 11 was added to 100 parts by weight of this emulgene paint i.
100 parts by weight of the water-soluble coating composition obtained above and 3 parts by weight of a cobalt dryer were added and mixed to obtain a colloidal emulsion type coating composition.

I had a flea. The results are shown in Example 14 in Table 2.

In other words, it exhibited good copper water resistance and watertightness.

Comparative example 3 The same manufacturing method as in Example 11 was used, except for the differences.

A water-soluble paint, Rinkamari, was obtained without incorporating any mountain bark.

100 parts by weight of this water-soluble transfer material and 100 parts by weight of the emulsion resin obtained in Example 14 were added and mixed to form a coro-C emulsion type paint coating. Obtained.

This colloidal emerald type O paint Mh1MIJ was applied in the same manner as in Example 11, and its water resistance and water resistance adhesion were investigated. The results are shown in the Comparative Example section of Table 2. As such, both water resistance and water resistant adhesion were low.

As is clear from Table 2, water-soluble coating composition O is significantly superior to coatings with a water content of 5% or more. A colloidal emul obtained by mixing a water-soluble coating composition obtained by uniformly dispersing 10 parts by weight of Yotayamapi per 100 parts by weight of a water-soluble coating resin, and an emal resin coating composition. Obtained by baking a resin layer type paint composition.
The water resistance of the coating film.

11O! The water retention property was much higher than that of the colloidal emulgene type paint, Linyuan, which does not contain any mountain bark.

Example 15 Water-soluble alkyd resin (Water Sea A/8-123
, manufactured by Dainippon Ink & Chemicals Co., Ltd., non-volatile content 50%)
Add 10 parts by weight of mountain bark to 10 parts by weight and 10 parts by weight of methylated methylolmelamine tree fat as a hardening agent (Sumimar M-40W, manufactured by f+i Yukagaku Kogyo Forest Co., Ltd., non-volatile content 80%), and add 10 parts by weight of mountain bark. m= with a grinder. The sand grinder used had a capacity of 11. Three disks with a diameter of 80 mm were installed in it, and galanupees with a diameter of Im were placed in it so that the closest packing ratio was 50%. Calcium 6 parts by weight Antifoaming agent 0.5
40 parts by weight of Butyl Cellsorg and 29 parts by weight of pure water were sequentially blended to obtain a water-soluble coating composition.

The coating composition was applied in the same manner as in Example 1.

The water resistance and water resistant adhesion of the coating film were investigated, and the results are shown in Table 3 and Example 15. As a comparative example, we also investigated O without adding any mountain bark. The results are shown in Table 6, Comparative Example 4.

Table 3 is based on the test results of Example 15 and Comparative Example 9. It can be confirmed that almost the same effect can be obtained even when a general commercially available resin is used as the resin used in the present invention.

[Brief explanation of drawings]

FIG. 1 is a diagram showing how fibrous ridges are uniformly dispersed in the coating film, and FIG. 2 is a diagram showing how particulate ridges are dispersed in the coating film. 1... Fibrous mountain skin 2... Particulate mountain skin

Claims (3)

[Claims] (1) A water-soluble paint composition mainly composed of a water-soluble paint resin, a solvent, and a mountain skin, which contains 0.5 to 50 parts by weight of a mountain skin based on 100 parts by weight of the water-soluble paint resin, Moreover, the water-soluble coating composition is characterized in that the mountain bark is made into a fiber state and uniformly dispersed in an amorphous three-dimensional direction. (2) Claim (1) characterized in that the mountain skin is in the form of fibers with a diameter of 0.002 to 0.1 μm.
The water-soluble coating composition described in . (3) 0.5 to 100 parts by weight of water-soluble paint resin
Adding 50 parts by weight to turn the mountain bark into a fiber state,
A crushing and mixing step for uniformly dispersing the fibrous mountain bark in the resin, a mixing step for adding and mixing an appropriate amount of solvent to the mountain bark dispersed resin to form a water-soluble coating composition, and a mixing step for applying the composition to the object to be coated. The coating process is characterized by a coating process in which the coating is applied to the surface of the coating and baked for 10 to 60 minutes at a temperature of 60 to 180 degrees Celsius to reduce the moisture content in the coating to 5% or less of the weight of the coating after curing and drying. A method for forming a coating film using a water-soluble coating composition.