JPS6254771A - Water-dispersible paint - Google Patents

Abstract

PURPOSE:To provide a water-dispersible paint which has excellent adhesion to substrates and topcoat, flame retardance and water resistance and is freed from the problem of blistering, by emulsifying an org. solvent soln. of a chlorinate high-molecular compd. in the presence of a surfactant. CONSTITUTION:100pts.wt. chlorinated high-molecular compd. having an MW of 3,000-100,000, a chlorine content of 50-71wt% and a Tg of 60 deg.C or above (e.g., vinyl chloride/vinyl propionate copolymer) is dissolved in 25-200pts.wt. org. solvent having a b.p. of 80-200 deg.C (e.g., n-hexane), If desired, plasticizer (e.g., di-2-ethylhexyl phthalate), stabilizer (e.g., epoxidized soybean oil), etc. are added thereto to obtain an org. solvent soln. 1-20pts.wt. nonionic surfactant having an HLB of 10-18 (e.g., polyoxyethylene nonylphenyl ether) or anionic surfactant (e.g., sodium laurate) is added to 100pts.wt. said soln. Water is gradu ally added thereto while stirring to emulsify the soln.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a water-dispersible paint used as an undercoat resealer for porous substrates.

[Background technology]

When painting the surfaces of base materials such as mortar and concrete, such as painting boards for building materials manufactured in factories or painting building materials at construction sites, these surfaces are porous and highly absorbent. When a top coat is applied, the vehicle in the paint is absorbed, which impairs the durability of the paint, making it impossible to form a film with sufficient physical properties, and not only requiring repeated recoating.
There were also problems with the durability of the paint film. Conventionally, when painting the surface of these porous substrates, a solvent-based paint is used as a sealer to prepare the base, and then
A top coat of paint was applied.

In these solvent-based sealers, the resin dissolved in the solvent penetrates deep into the porous substrate, so an undercoat film with sufficient adhesion to the porous substrate can be obtained.

However, this solvent-based sealer contains a large amount of volatile organic solvent, which poses problems such as air pollution and fire hazards during painting operations.

Therefore, in recent years, attempts have been made to use water-soluble resins and emulsion polymerization emulsions as sealers for the surface of porous substrates. However, water-soluble resins have problems with water resistance, chemical resistance, etc., and may be compromised by top coats.
Moreover, sufficient adhesion with the top coat film cannot be obtained.

In addition, emulsion polymerization emulsions have poor permeability to porous substrates, making it impossible to obtain an undercoat film with sufficient adhesion to the substrate.

Among them, in the case of room temperature drying paints, low pigment volume concentration emulsion paints (hereinafter referred to as "low PvC emulsion paints") such as water-based paints, single-layer elastic paints, and multi-layer elastic intermediate coatings can be applied. Water-based primer resealer is not supplied.

This is because in order for a low PvC emulsion paint to adhere, the resin used in the base coat resealer must have a high glass transition point (hereinafter referred to as rTgJ). This is because a film cannot be formed in this form.

[Purpose of the invention]

The present invention relates to a water-dispersible paint that is used as an undercoat resealer for porous substrates and has little risk of air pollution or fire. That is, by converting the resin into an organic solvent solution and emulsifying and dispersing it with the help of a small amount of surfactant, it provides nearly the same adhesion to the substrate and topcoat as conventional solvent-based sealers. In the case of room-temperature drying paints, the water absorption and moisture permeability of the sealer paint film are moderately increased by the action of the surfactant added to make it water-based, and the overall paint film is improved when a low PVc emulsion paint is applied as a top coat. The objective is to provide water-dispersed paints with significantly improved water resistance, especially blister resistance, compared to conventional solvent-based sealers. The objective is to provide a water-dispersible paint that can form a film.

[Disclosure of the invention]

The present invention is a water-dispersible paint used as a sealer for porous substrates, and has a molecular weight of 3000 to 1 o o o o.
o. The gist of the invention is a water-dispersed paint characterized by emulsifying an organic solvent solution containing a chlorinated polymer compound with a chlorine content of 50 to 71% by weight in the presence of a surfactant.

This invention will be explained in detail below.

The chlorinated polymer compound that can be used in this invention is a compound represented by chlorinated rubber, and the following are preferred for this invention.

Chlorinated polyolefins such as polybutadiene, polyisoprene, polyethylene, and polypropylene; copolymers of vinyl chloride and vinyl isobutyl ether; copolymers of vinyl chloride and vinyl propionate; copolymers of vinyl chloride and acrylic and vinyl acetate; Copolymer of vinylidene chloride and acrylic.

The above compounds can be used alone or in combination.

In the present invention, the above-mentioned chlorinated polymer compound needs to have a molecular weight within the range of 3,000 to 100,000. This is because the chlorinated polymer compound is dissolved in an organic solvent and emulsified, and it is necessary to form a solution with as low a viscosity as possible using a small amount of organic solvent. In addition, the molecular weight of the chlorinated polymer compound is 3
If it is less than 100,000, the film-forming properties will be poor, and a paint with sufficient topcoat adhesion will not be obtained. Problems similar to those described above arise, and the advantages of water-based production are diminished. For this reason as well, the molecular weight of the chlorinated polymer compound is limited to the above range.

The chlorinated polymer compound also has a chlorine content of 5
It needs to be 0 to 71% by weight (hereinafter referred to as "%"). When the chlorine content of the chlorinated polymer compound is less than 50%,
Due to poor cohesive force, a coating film with sufficient physical properties cannot be formed, and if it exceeds 71%, vinylidene-type chlorine substitution occurs in the case of chlorinated rubber or chlorinated polypropylene, resulting in a decrease in physical properties. . In the case of chlorinated polyethylene, if the chlorine content exceeds 71%, the solubility will decrease. When using so-called highly chlorinated products with a chlorine content of 61 to 71%, a small amount of plasticizer may also be used.
By doing so, the cohesive force and film-forming properties can also be adjusted.

When the water-dispersed paint of the present invention is used as a bake-dry type, it is preferable that the Tg of the chlorinated polymer compound is 60° C. or higher in order to maintain the blocking resistance of the paint film.

After the above-described chlorinated polymer compound is dissolved in an organic solvent, a plasticizer, a stabilizer, etc. are added as necessary to form an organic solvent solution. Water is gradually added to this organic solvent solution while stirring it with a homomixer or the like to form an emulsion, thereby producing the water-dispersed paint of the present invention. A surfactant is blended into at least one of the organic solvent solution and the aqueous layer.

Various plasticizers can be used in this invention, and examples include the following.

Di2-ethylhexyl phthalate, dihepsyl phthalate,
Phthalate esters such as dibutyl phthalate or phthalate mixed group ester plasticizers, trioctyl trimetate,
Aromatic carboxylic acid esters such as diethylene glycol dibenzoate, aliphatic dibasic acid esters such as dioctyl sebacate, phosphate ester plasticizers, fatty acid ester derivatives such as butyl oleate, epoxidized soybean oil, epoxidized Epoxy plasticizers such as linseed oil,
Chlorinated plasticizers such as chlorinated paraffin, chlorinated diphenyl, and chlorinated fatty acid methyl.

Among the above plasticizers, chlorinated paraffin, chlorinated diphenyl, and chlorinated Chlorine-containing plasticizers such as methyl fatty acids,
Di2-ethylhexyl phthalate, dihepsyl phthalate,
Phthalate esters such as diptyl phthalate are preferred for this invention.

Stabilizers are added to prevent destabilization of the emulsion system due to dechlorination of chlorinated polymer compounds. For example,
Preferred examples include epoxy resins such as bisphenol A type epoxy resin and bisphenol F type epoxy resin, and epoxy plasticizers such as the above-mentioned epoxidized soybean oil and epoxidized linseed oil.

Examples of organic solvents include aliphatic hydrocarbons such as n-hexane, n-octane, cyclohexane, petroleum ether, petroleum benzene, and ligroin; aromatic hydrocarbons such as benzene, toluene, xylene, ethylbenzene, diethylbenzene, and isopropylbenzene; Halogenated hydrocarbons such as methylene chloride, chloroform, carbon tetrachloride, and tetrachloroethylene; ketones such as methyl isobutyl ketone, diethyl ketone, and ethyl-n-butyl ketone; ethyl acetate, isopropyl acetate, and isobutyl acetate.

Esters such as n-amyl acetate, butanol.

Examples include alcohols or polyhydric alcohols such as amyl alcohol, fusel oil, and cellosolve acetate, and derivatives thereof.

Among the organic solvents mentioned above, those with a boiling point range of 80~
A temperature of 200° C. is preferred for this invention. When the organic solvent is a mixed solvent, 10
The boiling point of the % fraction is within the above range, i.e. 80 to 200°C
And the boiling point of the 90% fraction is also within the above range, that is,
Preferably, the temperature is 80 to 200°C. If we were to represent this relationship between boiling point and distillate in a diagram, it would be as shown in Figure 1.
The boiling point of all fractions between 10 and 90% is 80 to 200°C
The area in between (the shaded area in the figure) corresponds to this.

The boiling point range of the organic solvent is within the above range if the boiling point is 8.
At temperatures below 0°C, the solvent scatters too quickly and becomes inconvenient to handle; when it exceeds 200°C, the solvent scatters too slowly.
This is because the solvent tends to remain in the coating film and prevent the topcoat from adhering to it.

When the water-dispersed paint of this invention is used as a bake-drying paint used as an undercoat for factory-produced building boards, if the boiling point of the organic solvent is too high, when the building boards are stacked after painting, Therefore, blocking may occur. Therefore, in order to prevent such blocking, it is more preferable that the boiling point of the solvent is within the range of 80 to 150°C. Further, in this case, it is preferable to use a hydrophobic solvent having a solubility in water of 1 or less as the organic solvent.

When the water-dispersed paint of this invention is used as a room temperature drying paint in on-site construction, the boiling point of the solvent is 1.
It is more preferable that the temperature is within the range of 00 to 200°C. This is because when a water-dispersed paint is applied to a porous substrate, the emulsion coagulates on the surface of the porous substrate, and even though the water is absorbed by the porous substrate, the solvent does not evaporate and remains. This is because the chlorinated polymer compound can be kept as a solution and penetrate deep into the porous base material.

In addition, among the above-mentioned organic solvents, halogenated hydrocarbons are
Generally, they are not preferred because they are toxic, and alcohols, esters, ketones, etc. are not preferred because they have high compatibility with water and impair emulsion stability. However, in order to improve the solubility of chlorinated polymer compounds and adjust the emulsification state,
If necessary, it is an advantageous method to use such a solvent in combination.

The amount of the organic solvent as described above is not particularly limited in the present invention, but it is preferably 25 to 200 parts per 100 parts by weight (hereinafter referred to as "parts") of the chlorinated polymer compound. If the amount of the organic solvent is less than 25 parts, it will be difficult to emulsify the emulsion, and even if emulsification is possible, sufficient permeability to the porous substrate will not be obtained. In addition, if the amount of organic solvent added to 100 parts of the chlorinated polymer compound exceeds 200 parts, the amount of organic solvent will be too large and problems similar to those of solvent-based sealers will occur.
Not only does the advantage of making it aqueous disappear, but the viscosity of the organic solvent solution decreases too much, which tends to worsen the stability of the emulsion. Therefore, the amount of solvent to be added to 100 parts of chlorinated polymer compound is 25 parts.
The amount is preferably 200 parts.

As the surfactant used for emulsification, it is preferable to use at least one of anionic and nonionic surfactants. Preferred examples of the anionic surfactant include the following compounds.

Aliphatic sodium salts such as sodium laurate, sodium stearate, and sodium oleate; aliphatic potassium salts such as potassium laurate, potassium stearate, and potassium oleate; and fats such as ammonium laurate, ammonium stearate, and ammonium oleate. group ammonium salts, alkylbenzene sulfonates such as nonylbenzene sulfonate and dodecylbenzene sulfonate, and higher alkyl ether sulfate ester salts.

As the nonionic surfactant, the following compounds are preferred for this invention.

Polyoxyethylene nonylphenyl ether.

Polyoxyethylene gelicol type nonionic surfactants such as polyoxyethylene lauryl ether and polyoxyethylene oleyl ether, higher aliphatic amines, ethylene oxide adducts of aliphatic amides, copolymerization of polyoxyethylene and polyoxypropylene Polyhydric alcohol type and its ester type nonionic surfactants such as Pluronic type nonionic surfactants, Tween, and Spar 7.

The anionic surfactants and nonionic surfactants mentioned above can be used alone or in combination.

In general, anionic surfactants have strong emulsifying power (and have fewer problems with cloud point and PIT (phase transition temperature)), but they have drawbacks such as high foaming and poor chemical stability of the resulting emulsion. On the other hand, nonionic surfactants generally have low foaming properties, and by using indicators such as HLB, it is easy to select those with the required properties. Nonionic surfactants have problems such as cloud point and PIT.

Therefore, in the present invention, it is preferable to mix a plurality of the anionic surfactants and nonionic surfactants to compensate for their respective drawbacks and obtain a good and stable emulsion. .

In addition, when the water-dispersed paint of this invention is used as a bake-dry type, it is preferable to use a nonionic surfactant of HLBIO to 18 as the surfactant.

The amount of the surfactant to be used is not particularly limited in the present invention, but the amount of the surfactant to be blended is preferably within the range of 1 to 20 parts per 100 parts of the organic solvent solution. Within this range, the smaller the amount is, the more preferable it is, as long as the stability of the emulsion is not impaired. However, if the amount of the surfactant is less than 1 part, no effect can be obtained by adding the surfactant, and conversely, if the amount exceeds 20 parts, the remaining surfactant will form on the undercoat after the coating is formed. There is a risk that adhesion may be inhibited.

In the water-dispersed paint of this invention as described above, the resin dispersed in water is an organic solvent solution in which a chlorinated polymer compound is dissolved in an organic solvent, so it penetrates deep into the porous base material. It is possible to form an undercoat film with sufficient adhesion to the substrate.

The water-dispersed paint of this invention includes cases in which pigments are blended as necessary, and even in such cases, the examples of component blends and preferred examples of each component as explained above can be applied as is. It goes without saying that you can do it. Further, the water-dispersed paint of the present invention can be used as an intermediate coat or a top coat depending on the case.

As described above, since the water-dispersed paint of the present invention has a chlorinated polymer compound as its main component, it can be used as a sealer for room-temperature drying paints and baking paints, such as low PVC emulsion paints, and is water-based and can be used in small quantities. Since it contains only 100% of organic solvent, there is no risk of pollution or fire caused by the volatilization of organic solvents, and since it does not contain a large amount of solvent, which is a flying component, it can also reduce costs.

Porous substrates to which the water-dispersible paint of this invention can be applied include lightweight concrete, precast concrete, lightweight cellular concrete, and mortar.

Concrete, asbestos cement board, calcium silicate board and molded product thereof, magnesium carbonate board and molded product thereof, pulp cement board, wood wool cement board 2 gypsum board,
Examples include hardboard, plasterboard, dolomite plaster, slate board, and wood.

Next, examples of the present invention will be described together with comparative examples.

(Examples 1 and 2) Commercially available chlorinated polyethylene (
Molecular weight 4000. (66% chlorine content) was dissolved in xylene (boiling point 144°C), and a plasticizer (chlorinated paraffin), a dechlorination stabilizer (liquid epibis type epoxy resin) and a nonionic surfactant of HLB 12 were added. (polyoxyethylene nonylphenyl ether, a mixture of HLB 7 and 16) to form an organic solvent solution. While mixing this organic solvent solution with a homomixer, water was added to form an emulsion to obtain a water-dispersible paint.

Table 1 shows the amount of each component.

(Examples 3 and 4) A water-dispersed paint was prepared in the same manner as in Example 1.2, except that a chlorinated polymer compound having a molecular weight of 70,000 and a chlorine content of 52% was used. The blending amounts of each component are also shown in Table 1.

(Comparative Example 1) A water-dispersed paint was prepared in the same manner as in Example 1.2, except that a chlorinated polymer compound with a molecule of 12,000° and a chlorine content of 66% was used. The amount of each ingredient,
Similarly, it is shown in Table 1.

(Comparative Example 2) Examples 1 and 2 except that a chlorinated polymer compound with a molecular weight of 1 tl and a chlorine content of 52% was used.
The same procedure as above was carried out, but the viscosity of the resin solution was too high to emulsify it. The blending amounts of each component are also shown in Table 1.

In addition, as much as 400 parts of xylene was required to make this chlorinated polymer compound into a resin solution with a viscosity that could be emulsified, and such a formulation did not provide sufficient physical properties as a sealer. .

(Comparative example 3) As a chlorinated polymer compound, the molecule is　o　o　o.

Example 1 except that one with a chlorine content of 45% was used.
A water-dispersed paint was prepared in the same manner as in 2. The blending amounts of each component are also shown in Table 1.

(Example 5.6) As an organic solvent, a mixed solvent of Tsurpetz-100 (aromatic hydrocarbon mixed solvent, boiling point 157-175°C) and methyl isobutyl ketone (boiling point 116°C) (compounding ratio is by weight, -100: Methyl isobutyl ketone = 1
A water-dispersed paint was prepared in the same manner as in Example 1.2, except that this mixed solvent was used in the amount shown in Table 1 for 100 parts of the chlorinated polymer compound. Created. The blending amounts of each component are also shown in Table 1 (Example 7) To 275 parts of the organic solvent solution obtained in Example 2,
Add 14 parts of the same nonionic surfactant as in Example 2,
While mixing with a homomixer, 150 parts of water was added to prepare an emulsion. For this emulsion, add 90% water
part, titanium oxide 36 parts, polycarboxylic acid surfactant 1 part
A titanium dispersion paste containing 1 part and 2 parts of hydroxyethyl cellulose was added and mixed to obtain a white enamel undercoat paint. ' The following tests were conducted using the water-dispersed paints prepared in the above Examples and Comparative Examples. The results are shown in Table 2.

Stability after emulsification: The resulting water-dispersed paint was placed in a test tube, sealed with a rubber stopper, and left indoors for one month to observe stability after emulsification.

Initial adhesion: Brush the water-dispersed paint onto the slate board.
After drying for 2 to 3 hours to form an undercoat film, a low PvC emulsion paint (Nippe DAN Uni, manufactured by Nippon Paint Co., Ltd.) was applied as a topcoat to a thickness of about 1 mm and dried to obtain a topcoat film. After the top coat was dried at room temperature for 7 days, a cross-cut tape hatching test and a nail peeling test were conducted to observe initial adhesion.

Water resistance test: A sample similar to the above initial adhesion was prepared, and after immersing it in warm water at 40°C for one week, changes in its appearance were observed, and after drying the coating film after the test for 24 hours, Subsequent adhesion was observed by cross-cut tape hunting test.

Alkali resistance test: A sample similar to the above initial adhesion was prepared, and after immersing it in a 5% NaOH aqueous solution at 40°C for one week, changes in its appearance were observed, and the coating film was dried for 24 hours after the test. Thereafter, the secondary adhesion was observed by a cross-cut tape hatching test.

(Example 8) Molecule i13000. A chlorinated polymer compound with a chlorine content of 52% was used.
0 part was dissolved in 50 parts of xylene, and 1 part of a dechlorination stabilizer (liquid epibis type epoxy resin) and 5 parts of a nonionic surfactant of ILB 12 (polyoxyethylene nonylphenyl ether, a mixture of HLB 7 and 16) were added. In addition, an organic solvent solution was formed. While mixing this organic solvent solution with a homomixer, 350 parts of water was added to prepare an emulsion. To 90 parts of this emulsion, a titanium dispersion paste containing 10 parts of water, 20 parts of titanium oxide, 40 parts of calcium carbonate, 1 part of polycarboxylic acid surfactant, and 2 parts of hydroxyethyl cellulose was added and mixed. A white enamel primer paint was obtained. This white enamel undercoat paint was coated and dried in the same manner as in Examples 1 to 7, and Nippe DAN Uni was applied as a topcoat, and the same test was conducted. The results are also shown in Table 2.

Furthermore, when an anti-blocking test was conducted using this white enamel undercoat paint in the following manner, no blocking was observed.

Anti-blocking test: After applying water dispersion paint evenly to a thickness of 4 mils on the surface of black art paper at room temperature,
The sample was immediately placed in a thermostat at 100°C and dried for 10 minutes. Lay these two samples together so that the coating films on the surface of Black Art Gion are in close contact with each other, and place 5
Add a load of kg/cd and place in a thermostat at 50°C for 2 hours.
After holding it for 0 minutes, it was taken out from the thermostat, two pieces of black art paper were peeled off, and the presence or absence of blocking of the coating film was observed.

〔Effect of the invention〕

The water-dispersed paint of this invention has the above-mentioned structure, and since it is made of a chlorinated polymer compound, it has a low PvC.
Suitable for undercoating such as emulsion paints, it has sufficient adhesion as it penetrates into the inside of porous substrates, and is water-based.
The risk of pollution and fire caused by the volatilization of organic solvents is extremely low. Furthermore, the amount of organic solvent used is small, the coating viscosity can be adjusted by diluting with water, and the coating machine can be washed with water.
Painting costs can be significantly reduced.

[Brief explanation of the drawing]

FIG. 1 is a graph showing the preferred range of the relationship between the boiling point and the fraction when the organic solvent used in the present invention is a mixed solvent. Agent: Patent Attorney Takehiko Matsumoto Figure 1 Distillate (°mu)

Claims (7)

[Claims] (1) A water-dispersible paint used as a sealer for porous substrates, in which an organic solvent solution containing a chlorinated polymer compound with a molecular weight of 3,000 to 100,000 and a chlorine content of 50 to 71% by weight is used as a surfactant. A water-dispersed paint characterized by being emulsified in the presence of. (2) The boiling point of the organic solvent is within the range of 80 to 200°C, and the blending ratio of the chlorinated polymer compound and organic solvent in the organic solvent solution is 25 parts by weight of the organic solvent to 100 parts by weight of the chlorinated polymer compound. 200 parts by weight of the water-dispersed paint according to claim 1. (3) The surfactant is at least one of an anionic surfactant and a nonionic surfactant, and the blending ratio is 1 to 2 parts by weight per 100 parts by weight of the organic solvent solution.
The water-dispersed paint according to claim 1 or 2, which contains 0 parts by weight. (4) It is a room temperature drying type, and the boiling point of the organic solvent blended is within the range of 100 to 200°C.
The water-dispersed paint according to any one of Items 1 to 3. (5) Any one of claims 1 to 3, which is a bake-dry type, and the boiling point of the organic solvent blended is within the range of 80 to 150°C and the solubility in water is 1 or less. Water-dispersible paint as described. (6) The water-dispersed paint according to claim 5, wherein the chlorinated polymer compound has a Tg of 60° C. or higher. (7) The surfactant is a nonionic surfactant with an HLB of 10 to 18, and the amount thereof is 1 to 5 parts by weight per 100 parts by weight of the organic solvent solution. The water-dispersible paint according to item 6.