JPH07289988A - Method for coating and article coated thereby - Google Patents

Abstract

PURPOSE:To improve the safety and durability by using respectively a coating wherein an aqueous acrylate resin emulsion is an essential ingredient as an undercoating material and a coating wherein an aqueous fluoro-olefin-based resin emulsion is an essential ingredient as a topcoating material. CONSTITUTION:When coating is performed on a substrate, firstly, an under coating material is applied and then, a top coating material is applied thereon. In this case, a coating wherein an aqueous acrylic resin emulsion is an essential ingredient is used as an undercoating material. Then, a coating wherein an aqueous fluoro-olefin-based resin emulsion is an essential ingredient is used as a topcoating material. In addition, in an article wherein after an undercoating material is applied at first, a topcoating material is then applied, as the undercoating material and the topcoating material, the same coatings as the above-mentioned coating are respectively used. In addition, as the topcoating material, an aqueous resin emulsion prepd. by copolymerizing copolymerizable monomers consisting of fluoro-olefin, a carboxylic acid vinyl ester monomer and ethylene is incorporated as the essential ingredient.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a novel and useful coating method and an article coated by the coating method. More specifically, the present invention relates to a substrate in sequence,
Each of them comprises applying an undercoat material (A) containing an acrylic acid ester-based aqueous resin emulsion as an essential component, and further applying an overcoat material (B) containing a fluoroolefin-based aqueous resin emulsion as an essential component. The present invention relates to a highly practical coating method and an article coated with the coating method.

That is, the present invention is safe by sequentially coating an undercoat material containing a specific resin as an essential component and an overcoat material containing a specific fluoroolefin resin as an essential component, Moreover, it relates to a coating method and an article coated with the coating method, which can provide a coating film excellent in durability and substrate adhesion, and the like, which is extremely highly practical.

[0003]

2. Description of the Related Art In the field of exterior coatings, in recent years, coatings that are water-based, have excellent safety, and have extremely durable coatings that do not deteriorate or discolor over a long period of time. There are great demands on materials and construction methods.

With these applications as the main focus, in recent years,
The use of aqueous coating compositions based on aqueous emulsions of fluoroolefin copolymers has been extensively investigated.

However, the fluoroolefin-based copolymer emulsion is different from conventional acrylic styrene-based emulsions, vinyl ester-based emulsions, and the like in various exterior base materials such as cement-based base materials. It had a drawback of being poor in adhesion to.

Furthermore, when the surface of a base material such as such a cement-based base material is porous or coated on a base material with conspicuous unevenness, the coating material soaks into the base material and It has also been pointed out that there is a tendency that a defective appearance is apt to occur because a film is not formed.

Therefore, as a result, it becomes difficult to obtain a coating film having excellent durability, which is a characteristic of fluoroolefin resins, due to such poor adhesion to the substrate and poor appearance.

In order to improve the adhesion of the topcoat material to the base material and to improve the appearance of the coating, a method of interposing a basecoat material between the base material and the topcoat material has hitherto been a topcoat material. Although it has been widely used regardless of the type of material, the combination of an overcoating material and an undercoating material containing a fluoroolefin copolymer emulsion as an essential component provides sufficient adhesion. At present, the one with extremely high practicality, which has the appearance, has not been obtained yet.

As described above, as long as the conventional technique is followed, the water-based top coating material containing the highly durable fluoroolefin copolymer emulsion as an essential component has its own problems, especially, in the adhesion to the substrate. In reality, it is impossible to obtain a coating film or an article having adhesiveness and high appearance, which is possessed by conventional acrylic styrene emulsions and vinyl ester emulsions.

[0010]

Therefore, in the adhesion of the base material and in the final coating film, the performance of the fluoroolefin-based aqueous coating composition known in the prior art is not impaired, and It is a very problem to be solved by the present invention to provide an article coated by such a novel coating method and a coating method having extremely high practicality, such as one having a high appearance.
It is also the main object of the present invention.

[0011]

Therefore, the present inventors have
In view of such a current situation, as a result of earnestly and repeatedly studying, in particular, in order to obtain a coating film having excellent base material adhesion and a high appearance, an undercoating material containing a specific resin as an essential component, The above-mentioned problems can be satisfactorily solved by successively coating the above-mentioned top-coating material containing a fluoroolefin resin as an essential component, and the above-mentioned object can be achieved brilliantly. Upon finding the above, the present invention has been completed here.

That is, the present invention basically uses a coating material (paint) having an acrylic ester-based aqueous resin emulsion as an essential component as an undercoating material for each of the base materials, It is intended to provide a novel and useful coating method, which comprises sequentially coating a coating material (paint) containing a fluoroolefin-based aqueous resin emulsion as an essential component as an overcoat material.

More specifically, this topcoat material is obtained by copolymerizing a fluoroolefin, a vinyl carboxylic acid ester monomer and a copolymerizable monomer containing ethylene as an essential component. It is intended to provide a novel coating method that contains an aqueous resin emulsion as an essential component.

In addition, the present invention is an article coated by such a novel coating method, that is, an article which is first coated with an undercoat material and then with an overcoat material, wherein the undercoat material is acrylic. A new and useful coated article, which comprises using a coating material containing an acid ester-based aqueous resin emulsion as an essential component, while using a coating material containing a fluoroolefin-based aqueous resin emulsion as an essential component as the top coating material. Is also intended to be provided.

Here, first, the above-mentioned undercoat material constituting the coating method of the present invention [hereinafter, the component is also referred to as an undercoat material (A). ] Contains an aqueous resin centering on an acrylic ester-based aqueous resin emulsion as a binder component, and further, if necessary, various additive components such as a film-forming aid or a pigment. A coating material containing also is referred to.

Acrylic ester-based aqueous resin emulsion, which is an essential component of the undercoat material (A), refers to a carboxyl group in various carboxyl group-containing compounds such as (meth) acrylic acid as a monomer. for,
The so-called (meth) acrylic acid ester in a form in which various alkyl groups are bonded is an essential component,

Further, it refers to an aqueous resin emulsion in which other copolymerizable monomers are also copolymerized, if necessary, and, for example, polymerization initiators are added in the presence of emulsifiers. Is obtained by a known and conventional emulsion polymerization method.

As the acrylic acid esters mentioned here, only typical ones are exemplified, methyl (meth) acrylate, ethyl (meth) acrylate, (normal-, iso- or tertiary) butyl. (Meth) acrylate, 2-ethylhexyl (meth)
Various alkyl esters of (meth) acrylic acid having a linear, branched or cyclic C ₁ -C ₁₂ alkyl group such as acrylate or cyclohexyl (meth) acrylate, or benzyl (meth) Examples include various (substituted) aromatic nucleus-containing (meth) acrylic acid esters such as acrylates.

On the other hand, if only representative examples of other copolymerizable monomers are given, vinyl acetate, vinyl propionate, vinyl stearate and the like, and further "Veova" ( Vinyl ester monomers such as vinyl ester manufactured by Shell Co. of Netherlands);

Alkyl vinyl ethers having various linear or branched alkyl groups or various (alkyl-substituted) cyclic alkyl groups,

Various aromatic vinyl compounds such as styrene and other derivatives of styrene,
Various unsaturated dibasic acids (unsaturated dicarboxylic acids) such as maleic acid, and esters (half esters) of various unsaturated dibasic acids with monohydric alcohols,

Alternatively, represented by (meth) acrylic acid or crotonic acid, maleic acid, fumaric acid, itaconic acid or citraconic acid, etc., various acid anhydride group-containing units such as maleic anhydride or itaconic anhydride Of various carboxyl group-containing monomers or dicarboxylic acids represented by various unsaturated bond-containing hydroxyalkyl ester monocarboxylic acids, such as adducts with various monohydric alcohols. Examples thereof include basic acids (dicarboxylic acids).

In particular, in order to improve the stability of the aqueous dispersion and to improve the adhesiveness to the base material in the final use situation, various types of the above-mentioned various materials are used. The introduction of the acid group-containing monomers of is desirable.

Furthermore, various hydroxyl group-containing monomers, such as various (meth) acrylic acid hydroxyalkyl esters, can also be mentioned as typical ones.

Further, as the monomer having another active group or functional group, an amide group, an amino group, a cyano group, a phosphoric acid ester group or a sulfonic acid group, respectively,
Various monomers can also be mentioned.

In addition, as the crosslinkable monomers, various kinds of monomers each having two or more polymerizable unsaturated bonds in the molecule, such as butadiene or decadiene, or vinyltriene is used. Various hydrolyzable silyl group-containing monomers such as ethoxysilane or trimethoxysilyl vinyl ether may also be mentioned.

Acrylic ester-based aqueous resin emulsions, which are the essential components of the undercoating material, are used in the method of the present invention or in obtaining the coated article of the present invention. It is a main raw material component that constitutes

In the present invention, in order to prepare the acrylic ester type aqueous resin emulsion, various monomers as described above are added to the polymerization initiator in an aqueous medium and in the presence of emulsifiers. The radical polymerization reaction may be performed depending on the type.

In this case, various emulsifiers such as known and commonly used anionic emulsifiers and nonionic emulsifiers can be used.

Further, in combination with these emulsifiers, various kinds such as so-called water-soluble oligomers composed of polycarboxylic acids or sulfonates, polyvinyl alcohol or hydroxyethyl cellulose are used. The water-soluble polymer substance can be used as a protective colloid.

It is needless to say that a so-called soap-free emulsion type polymerization method in which the polymerization is carried out using water-soluble oligomers without using an emulsifier at all.

As the above-mentioned polymerization initiators, only representative ones are known and commonly used ones such as peroxides, persulfates or azo compounds. The emulsion polymerization method is not particularly limited as long as it is generally used.

In addition, these polymerization initiators and various metal ions represented by copper sulfate and the like,
Further, there is no problem even by a so-called redox polymerization method such as a combined use with various reducing agents represented by sodium sulfite and the like.

The radical polymerization reaction is carried out at about 40 ° C.
It may be carried out at a reaction temperature within the range of about 90 ° C. to about 90 ° C. However, depending on the case, there is no problem even if the polymerization is carried out under a temperature condition lower than that.

The acrylic ester-based aqueous resin emulsion thus obtained has a suitable minimum film-forming temperature in the range of about -20 ° C to 50 ° C. The particle diameter of the acrylic ester-based aqueous resin emulsion is generally in the range of 0.05 to 0.5 micron (μm).

Next, used in the method of the present invention,
Alternatively, the above-mentioned topcoat material used in obtaining the coated article of the present invention [hereinafter, the component is also referred to as a topcoat material (B). ] Will be described.

That is, the overcoat material (B) contains a water-based resin centering on a fluoroolefin-based water-based resin emulsion as a binder component, and further, if necessary, a film-forming aid or a pigment, etc., respectively. And other types of additive components and the like.

The fluoroolefin-based aqueous resin emulsion, which is an essential component of the overcoat material (B), is a carbon that forms a polymerizable carbon-carbon double bond (polymerizable unsaturated double bond) as a monomer. An essential component is a so-called fluoroolefin, which is a monomer in which at least one fluorine atom is directly bonded to an atom.

Furthermore, it means an aqueous resin emulsion in a form in which other copolymerizable monomers are also copolymerized, if necessary. For example, polymerization initiators are present in the presence of emulsifiers. As obtained by a well-known and conventional emulsion polymerization method.

Examples of the above-mentioned fluoroolefins which are particularly representative are vinyl fluoride, vinylidene fluoride, tetrafluoroethylene, hexafluoropropylene and chlorotrifluoroethylene.

Among these, particularly desirable are hexafluoropropylene, chlorotrifluoroethylene and / or vinylidene fluoride, and more preferably chlorotrifluoroethylene from the viewpoint of controlling the reaction during polymerization. Is appropriate to use.

As the other copolymerizable monomers, only representative ones will be exemplified. The acrylic ester type aqueous resin emulsion, which is the main component of the undercoat material (A) as described above, is prepared. All the raw materials that can be used in this case are exemplified, and above all, the following compounds can be exemplified as preferable monomers.

That is, for example, vinyl acetate, vinyl propionate, vinyl butyrate, vinyl isobutyrate, vinyl pivalate, vinyl caproate, vinyl 2-ethylhexanoate, vinyl versatate, vinyl laurate, vinyl stearate,

Vinyl salicylate, monochlorovinyl acetate, vinyl cyclohexanecarboxylate or p-ter
In addition to t-butyl vinyl benzoate, etc.,
"Beoba" (Vinyl ester manufactured by Shell in the Netherlands)
First, various vinyl carboxylate-based monomers such as those listed above can be listed.

Among these monomers, vinyl pivalate, vinyl caproate, vinyl 2-ethylhexanoate, vinyl versaticate (vinyl neononanoate or vinyl neodecanoate), vinyl laurate, vinyl stearate, cyclohexane. Have 5 or more carbon atoms, such as vinyl carboxylate or "Veova",

A vinyl ester of a carboxylic acid having a linear, branched or cyclic alkyl structure is more preferable because it improves the weather resistance of the final coating. More preferably, the use of one having 6 or more carbon atoms is suitable.

Further, various (halogenated) olefins such as vinyl chloride or vinylidene chloride or ethylene, propylene, butene-1, iso-butylene (isobutylene), heptene or hexene are typical examples of those which can be copolymerized. is there. Among these, ethylene is a preferred copolymerizable monomer.

As the fluoroolefin-based aqueous resin emulsion, copolymerizable monomers (comonomer) of fluoroolefin, vinyl carboxylic acid ester-based monomer and ethylene are essential components.
An aqueous resin emulsion obtained by copolymerizing the above-mentioned by a known and common emulsion polymerization method is the most desirable one from the viewpoints of the copolymerizability of monomers, durability and adhesion.

This is because the fluoroolefin improves the durability, the carboxylic acid vinyl ester-based monomer improves the adhesion and the appearance, and the ethylene, especially This is because it can be used for the purpose of adjusting and adjusting the glass transition temperature (Tg) and copolymerizability of the resulting copolymer.

Among the monomers capable of copolymerization, it is particularly preferable to use crotonic acid or itaconic acid among the acid group-containing monomers from the viewpoint of copolymerizability. In order to improve the stability of the aqueous dispersion, and in order to improve the adhesion to the substrate in the final use, the introduction of the acid group-containing monomers, This is a particularly desirable place.

In addition, the use of various crosslinkable monomers as described above is desirable.

The reason for introducing the crosslinkable monomers is as follows.
In particular, it is also for the purpose of improving the so-called durability such as water resistance, alkali resistance and solvent resistance, or is a polymer having a low glass transition point and a film obtained from the polymer. On the other hand, it is also to provide toughness.

The above listed monomers are appropriately selected and used in consideration of various physical properties of the finally obtained copolymer, glass transition temperature, minimum film forming temperature and the like. .
Preferably, any combination of fluoroolefin, carboxylic acid vinyl ester-based monomers, olefins, carboxyl group-containing monomers and crosslinkable monomers,

Particularly preferably, from the viewpoint of adhesion when used as a topcoat material, among the above combinations, fluoroolefin, vinyl carboxylate carboxylic acid monomers, and ethylene are essential components. Is a combination of.

The above-mentioned substances, which are used in the method of the present invention or used in obtaining the coated article of the present invention, are the essential components of the overcoat material (B), the fluoroolefin-based aqueous solution. It is the main raw material component that constitutes the resin emulsion.

In the present invention, in order to prepare the fluoroolefin-based aqueous resin emulsion, the above-mentioned various monomers are added to the acrylic ester-based aqueous resin emulsion used as the undercoat material (A). Similarly to the case, the radical polymerization reaction may be carried out with the polymerization initiators in the aqueous medium and in the presence of the emulsifiers.

Therefore, the emulsifiers, protective colloids, polymerization initiators or reducing agents, etc., as described above, can be similarly used.

As the emulsifiers, preferably used are anionic emulsifiers having no fluorine atom and / or nonionic emulsifiers having no fluorine atom.

However, even the combined use of fluorine atom-containing emulsifiers represented by perfluorooctanoate and the like is by no means hindered.

Such a radical polymerization reaction can be carried out within a gauge pressure range of about 1 to about 100 kg / cm ² and a reaction temperature range of about 50 ° C. to about 150 ° C. Good. In some cases, there is no problem even if the polymerization is carried out under a higher pressure or under a temperature condition lower than that.

The amount of fluoroolefin-based monomers contained in the total monomers (total amount of monomers) is about
It should be 30% by weight or more. If it is less than that, the durability of the finally obtained coating film will be unsatisfactory.

The fluoroolefin-based water-based resin emulsion thus obtained has a number average molecular weight of about 5,0 in terms of no crosslinkable monomers.
Within the range of 0 to 1,000,000, and the weight average molecular weight is generally 10,000 to 3,000,000.
And the minimum film forming temperature is about −
A range of 30 ° C to + 60 ° C is suitable.

The particle diameter of the fluoroolefin aqueous resin emulsion is generally 0.02 to 0.
The range of 5 μm is suitable.

Next, the undercoat material (A) and the overcoat material (B)
The composition of each of these coating materials will be described below.

Such a coating material (paint) may be used as a resin alone depending on its intended use and target performance, or may be blended with a film-forming aid or pigments. It may also be used in various forms, such as a stick.

In the preparation of the coating material used in the present invention, if necessary, only representative examples of the film-forming aids that can be used are given below. 2,2,4-Trimethylpentane-1,3-, made by Eastman Chemical Company
Diol isobutyrate), (mono- or di-) ethylene glycol- (mono- or di-) alkyl ether,

(Mono-, di- or tri-) propylene glycol- (mono- or di-) alkyl ether, (mono- or di-) ethylene glycol- (mono- or di-) alkyl ester, (mono-, The-
Or tri-) propylene glycol- (mono- or di-) alkyl ester, phthalic acid dialkyl ester or benzyl alcohol.

The mixing ratio of these film-forming aids is as follows:
It is appropriately selected depending on the coating conditions and drying conditions, but is generally within a range such that the amount of the film-forming aid does not exceed about 60 parts by weight with respect to 100 parts by weight of the resin component. Is appropriate.

Further, in preparing the coating material used in the present invention, if necessary, only typical examples of the pigments used are exemplified, and titanium oxide, mica, talc, clay, Precipitated barium sulfate,
Various inorganic pigments such as silica powder, calcium carbonate, iron oxide, zinc oxide, aluminum powder or carbon black, or

Various organic pigments such as azo type, phthalocyanine type and quinacridone type, and further various plastic pigments are used. It is appropriately selected and used according to each final purpose.

A suitable blending ratio of such pigments is a solid content ratio within a range such that the amount of the pigments does not exceed about 200 parts by weight with respect to 100 parts by weight of the resin component. .

Further, in preparing the coating material used in the present invention, if necessary, only representative examples of the pigment dispersants that can be used are exemplified. Sodium tripolyphosphate or potassium tripolyphosphate. Or naphthalene sulfonate,

Further, anionic emulsifiers, nonionic emulsifiers, poly (meth) acrylic acid type dispersants and the like are used, and further, styrene-maleic acid type copolymers and the like are used.

Next, when preparing the coating material used in the present invention, if necessary, only representative examples of usable thickeners will be given.
In addition to polyvinylpyrrolidone-based thickeners or polycarboxylic acid-based thickeners, various cellulose-based thickeners represented by hydroxyethyl cellulose or carboxymethyl cellulose; or urethane-based thickeners is there.

Among these, the use of polycarboxylic acid-based thickeners is advantageous in terms of stability when compounded with the above-mentioned fluoroolefin-based aqueous resin emulsion, which is used in the preparation of the overcoat material (B). From the above, it is particularly desirable for the overcoat material (B).

The amount of each of the various types of pigment dispersants or thickeners as mentioned above may be an appropriate amount within a known and commonly used range.

In addition to these, various additives necessary for preparing a coating material, that is, for forming a coating material, for example, wetting agents, thixotropic agents, ultraviolet absorbers, antioxidants, etc. The water-repellent agents, anti-freezing agents, antiseptic / antifungal agents, antifoaming agents and the like can also be appropriately selected and used in consideration of various properties of the obtained coating film.

The amount of each of the various additives as mentioned above may be used in an appropriate amount within the known and commonly used range.

As the coating material used in the present invention, other water-based resins such as amino resins, epoxy resins and acrylic resins can be used as long as they do not deviate from the object of the present invention or do not impair the effects of the present invention. It is also possible to compound various resins, such as resins or urethane resins.

The compounding method is not particularly limited, but particularly when pigments are used, the pigments are dispersed in advance by using a part or all of the pigment dispersant,
The method of adding the resin component or the resin component and various additives such as film-forming aids and thickeners is particularly desirable.

Thus, the undercoating material (A) and the overcoating material (B) used in the method of the present invention or used in obtaining the coated article of the present invention can be obtained. When applying or coating various base materials, the application method is as follows:

These undercoat materials (A) and overcoat materials (B)
Although not particularly limited in the case of sequentially coating and coating with and, as the coating time of the overcoat material (B), the undercoat material and the overcoat material are sequentially applied to the base material. It is said that this undercoat material was dried to such an extent that the undercoat material would not be redissolved when
Above all, it is desirable in terms of appearance.

The coating method is not particularly limited, but a particularly desirable example thereof is brush coating, roller coating, spray coating or roll coater coating, or showering coating. It is particularly desirable to use such a method.

In this case, particularly for construction site construction, it is desirable to use a paint having a minimum film-forming temperature of about 0 ° C. or less with the film-forming auxiliary added, and as a coating method. It is particularly desirable to use a method such as brush coating, roller coating or spray coating.

For so-called factory line coating of various roofing materials such as roof tiles and wall materials, a generally-used forced heating drying method is used, and a film-forming aid is prepared according to the drying conditions. The minimum film formation temperature in the state of adding
Generally, it is desirable to select and use a coating material having a temperature of 60 ° C or lower, preferably 50 ° C or lower,

As the coating method at that time, roll coater coating, roller coating, spray coating or showering coating is used, and further, flow coater coating or dipping coating such as dipping is particularly preferable. desirable.

Whether it is for such on-site construction or for factory line painting or heating forced drying line painting, approximately 60
In order to carry out in an atmosphere at a temperature of ℃ or more, substantially at a temperature of about 200 ℃ or less, after coating, if necessary, after setting time, by heat drying,

Especially, the film forming property or film forming property is
In order to make it even stronger, and in order to secure the long-term durability of the coating film, and to further reduce blocking as much as possible, and in particular to secure stain resistance, etc. Is also particularly desirable.

In any of these various coating systems, in the coating method according to the present invention,
As the dry film thickness of the water-based coating composition, first, in the case of the undercoat material (A), about 1 μm or more is suitable. This is because if the undercoat material has a thickness of less than about 1 μm, the adhesion of the base material is likely to be poor, or the appearance is likely to be poor.

On the other hand, in the case of the overcoat material (B), it is about 5
It is appropriate that the thickness is μm or more. This is because if the thickness of the overcoat material is less than about 5 μm, the long-term durability of the coating is likely to be insufficient.

According to the invention, inter alia, as a result,
In addition to being excellent in adhesion, it is also possible to obtain a coating having a high appearance.

In the present invention, particularly preferable and highly practical base materials are cement base materials, metal plates or wood base materials.

As typical examples of the above-mentioned cement-based base material, only representative ones such as cement mortar, cement concrete, ALC (lightweight concrete), asbestos concrete, wood cement board or calcium silicate board can be used. Examples include so-called hardened concrete skeletons and cement molded products prepared by hydrating and crystallizing a substance.

Further, only representative examples of the above-mentioned metal plate are exemplified, including various steel plates such as mild steel plate, zinc-treated steel plate or tin plate, and further aluminum, copper. Alternatively, it is various non-ferrous metal plates such as titanium.

Further, only representative examples of the wood base material are cedar, pine or cypress, and further, lauan wood and the like.

In addition to these base materials, it can be applied to and utilized for plastics, glasses, papers, fibers and the like.

In the present invention, the undercoat material (A) and the overcoat material (B), which are used in the method of the present invention or used for obtaining the coated article of the present invention, are sequentially coated. Such a coating method is, among other things, that it is possible to form a coating having excellent durability and substrate adhesion, and a high appearance.

As a coating method for exterior or interior: cement-based substrates, metal plates, wood substrates, plastics, or inorganic substrates other than cement-based substrates, papers or fibers, etc. It can also be used as a method for coating medium-based cement-based substrates, metal plates or wood substrates;

[0099]

EXAMPLES Next, the present invention will be explained more concretely by reference examples, examples and comparative examples, but the present invention is by no means limited to these examples. Absent. In the following, all parts and% are based on weight unless otherwise specified.

Reference Example 1 [Preparation Example of Fluoroolefin-Based Aqueous Resin Emulsion (B)] A 2 liter stainless steel pressure-resistant reaction vessel (autoclave) system equipped with a stirrer, a nitrogen inlet tube, a thermometer and a temperature controller. After thoroughly replacing the inside with nitrogen gas,

800 parts of ion-exchanged water, 20 parts of sodium dodecylbenzenesulfonate and 20 parts of polyoxyethylene nonylphenyl ether, and 10 parts of borax (borax) as a pH buffer were charged and dissolved. .

Then, 200 parts of vinyl acetate and 10 parts of hexadiene were added thereto, and further 280 parts of vinyl neononanoate, 10 parts of crotonic acid and 500 parts of liquefied and collected chlorotrifluoroethylene were added. It was

Thereafter, ethylene gas was added at 15 kg /
It was pressed in until it reached cm ² . The internal temperature of the autoclave was raised to 80 ° C. At this time, ethylene gas was adjusted so that the pressure in the system during the reaction was about 30 kg / cm ² .

Subsequently, at the same temperature, an aqueous catalyst solution in which 5 parts of potassium persulfate was dissolved in 200 parts of ion-exchanged water was injected into the reaction vessel under pressure for 3 hours. After the addition of the aqueous catalyst solution, the temperature was maintained at the same temperature for 10 hours to allow the polymerization reaction to proceed to obtain the desired fluoroolefin-based aqueous resin emulsion.

The pH during the reaction proceeded at 3.5. During the reaction, the pressure in the system was lowered as the monomers were consumed, and the pressure of the reaction system was kept at 30 kg / cm ² by introducing ethylene each time.

After completion of the reaction, after cooling to room temperature,
14% aqueous ammonia was added until the pH reached about 7.5, and a silicon-based defoaming agent was also added, followed by thorough stirring.

After that, the system pressure is returned to normal pressure,
Further, the unreacted gas dissolved in the dispersion was distilled off under reduced pressure. The thus-obtained dispersion is a white fluoroolefin-based aqueous resin having a nonvolatile content of 52%, a pH of 7.2, a minimum film-forming temperature of 38 ° C., and an average particle diameter of 0.08 μm. It was an emulsion. Hereinafter, this is abbreviated as the base resin component (B-1).

The resin component (B-1) had a fluoroolefin content of about 47 wt% as determined by elemental analysis, ion chromatography analysis, infrared absorption spectrum and composition analysis by pyrolysis gas chromatography (GPC). %
It was confirmed that

Reference Example 2 (Same as above) In the same apparatus as in Reference Example 1, 800 parts of ion-exchanged water, 20 parts of sodium dodecylbenzenesulfonate and 20 parts of polyoxyethylene nonylphenyl ether,
10 parts of borax (borax) as a pH buffer was charged and dissolved.

Then, 340 parts of "Veova 9" (vinyl ester of branched saturated aliphatic carboxylic acid manufactured by Shell Co., Netherlands) and 10 parts of hexadiene were added thereto, and further 10 parts of crotonic acid were added. And 640 parts of liquefied and collected chlorotrifluoroethylene were also added.

After that, the internal temperature of the autoclave was set to 8
The temperature was raised to 0 ° C.

Then, while stirring, at the same temperature,
An aqueous catalyst solution in which 5 parts of potassium persulfate was dissolved in 200 parts of ion-exchanged water was pressed into the reaction vessel for 3 hours. Even after the addition of the aqueous catalyst solution, at the same temperature,
By holding for 10 hours to allow the polymerization reaction to proceed, a target fluoroolefin-based aqueous resin emulsion was obtained.

After completion of the reaction, after cooling to room temperature,
14% aqueous ammonia was added until the pH reached about 7.5, and a silicon-based defoaming agent was also added, followed by thorough stirring.

The dispersion thus obtained has a nonvolatile content of 4
It was 6%, the pH was 7.2, the minimum film-forming temperature was 48 ° C., and the average particle size was 0.08 μm, which was a white fluoroolefin-based aqueous resin emulsion. Hereinafter, this is abbreviated as the base resin component (B-2).

The resin component (B-2) had a fluoroolefin content of about 49% by weight as determined by elemental analysis, ion chromatography analysis, infrared absorption spectrum and composition analysis by pyrolysis gas chromatography (GPC). It was confirmed to be a thing.

Examples 1 and 2 and Comparative Examples 1 to 3 Various coating materials prepared as described below were sequentially coated to obtain various coated articles.

Next, an application test was conducted on each coated article. The results are summarized in Table 1.

Pigment dispersants: "DKS-Discote N"
-14 "[styrene-maleic acid copolymer manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.]

Pigments (titanium oxide): "Taipec C
R-50] [Product of Ishihara Sangyo Co., Ltd.]

Thickeners: "Primal TT-935"
(Polycarboxylic acid-based polymer thickeners manufactured by Rohm and Haas, USA)

Film-forming aids: "Texanol" (2,2,4-trimethylpentane-1,3-diol isobutyrate manufactured by Eastman Chemical Company, USA)

Defoaming agents: "SN deformer 373"
[San Nopco Products]

(1) Preparation Example of Undercoat Material (A)

As the aqueous resin emulsion, "Boncoat 5499L" [acrylic ester emulsion manufactured by Dainippon Ink and Chemicals, Inc .; nonvolatile content = 30]
%], And as a control product, "Ebadic EP-11" [ethylene-vinyl acetate emulsion manufactured by Dainippon Ink and Chemicals, Inc .; nonvolatile content = 50%]
Was used to obtain various undercoat materials with the following mixing ratios.

That is, the one using "Boncoat 5499L" is hereinafter abbreviated as the undercoat material I, while
What uses "Ebadic EP-11" is hereafter abbreviated as undercoat material II.

Formulation example of undercoat material (A)

Aqueous resin emulsion 250 parts “Texanol” 15 parts Water (*) Appropriate amount ──────────────────────────────── ──── (The above ingredients were agitated by the usual method.)

(*) The nonvolatile content (solid content) of the paint was adjusted to 15% with an appropriate amount of water.

(2) Preparation Example of Topcoat Material (B)

First, the base resin components (B-1) and (B-2) obtained in Reference Examples 1 and 2, respectively, were adjusted to have a nonvolatile content of 45%, and then, Various topcoat materials were prepared with such a blending ratio.

Topcoat (B) compounding example

Water 20 parts “DKS-Discoat N-14” 16 parts (nonvolatile content = 28%) 28% ammonia water 0.2 parts “Taipaque CR-50” 129 parts “SN Deformer 373” 1.5 Part Ethylene glycol 9 parts ──────────────────────────────────── (The above components are used for high-speed dispersion. It was dispersed by.)

Fluoroolefin-based aqueous resin emulsion 260 parts (nonvolatile content = 45%) Texanol 25 parts 5% diluted “Primal TT-935” 12 parts Water proper amount ──────────────── ───────────────────── (The above ingredients were agitated by the usual method.)

Non-volatile content of paint = 53-45%

Then, each of the coating materials thus obtained was applied onto a slate plate [base material (1)] or a zinc phosphate-treated steel sheet [base material (2)] by the following coating method. First, an undercoating material and then an overcoating material were sequentially applied and dried to obtain various coated articles.

Thereafter, each coated article was subjected to various performance evaluation tests. The results of those tests are summarized in Table 1.

Coating method: After coating the base material with a brush so that the coating amount of the undercoat material (A) is 100 g / m ² , it is left to stand at room temperature for one day and dried. Then, the top coat material (B) was further applied thereon with a brush so that the coating amount was 140 g / m ^2, and then left at room temperature for 14 days to dry.

[0138]

[Table 1]

<< Footnote in Table 1 >> The topcoat material (B) was compounded so that the pigment volume concentration (PVC) was 15% by volume.

The specific gravity of the solid content of the fluoroolefin copolymer is 1.5, and the specific gravity of titanium oxide is 4.2.

The topcoat material (B) was prepared by adjusting the pH and system viscosity by adjusting the pH to 8 with 14% ammonia water after its formulation.

The gloss value is 60 using a Murakami gloss meter.
It was expressed by the degree gloss value (that is, 60 degree specular reflectance:%).

The substrate adhesion was determined by cutting each coating film with a cutter knife into 5 × 5 crosses at 2 mm intervals, pressing cellophane tape, and then peeling it off. It is visually determined from the state of peeling of the coating film from the material.

The criteria for evaluation and evaluation of the adhesiveness are as follows. ○ ……… No peeling of the coating film △ ………… Slightly peeled coating film × ………… Peeling of the coating film

Further, the accelerated weather resistance was evaluated by visually observing the appearance of each coating film after exposure (accelerated weather resistance test) for 5,000 hours with a due panel light control weather meter. It is a thing.

The criteria for evaluation and judgment of accelerated weather resistance are as follows. ○: Appearance that has no abnormalities in appearance. △: Appearance of glossiness on the coating film. X: Appearance of blistering, peeling, or whitening on the coating film.

As described above, it can be known that the film (coating film) obtained according to the coating method of the present invention has a satisfactory and satisfactory performance in any test.

[0148]

INDUSTRIAL APPLICABILITY As described above, the coating method according to the present invention is superior to the coating film obtained according to the prior art, in particular, in the adhesiveness to the substrate, and therefore, the high durability and It is extremely practical in that a film or a coated article having a high appearance can be produced.

Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display location C09D 5/00 PPF 5/02 127/12 PFG 133/08 PFX

Claims (7)

[Claims] 1. A coating method comprising first coating a base material with an undercoating material (A) and then applying a topcoating material (B), wherein the undercoating material (A) is acrylic. While using a paint containing an acid ester-based aqueous resin emulsion as an essential component, the above-mentioned overcoat material (B)
As a coating method, a coating containing a fluoroolefin-based aqueous resin emulsion as an essential component is used. 2. An aqueous resin emulsion obtained by copolymerizing a fluoroolefin, a carboxylic acid vinyl ester-based monomer and a copolymerizable monomer containing ethylene as an essential component as the above-mentioned topcoat material (B). The coating method according to claim 1, which is contained as an essential component. 3. An article coated with an undercoat material (A) and then with an overcoat material (B), wherein an acrylic ester-based aqueous resin emulsion is essential as the undercoat material (A). A coated article, characterized in that a paint containing a fluoroolefin-based aqueous resin emulsion as an essential component is used as the top coat material (B) while using a paint as a component. 4. An aqueous resin emulsion obtained by copolymerizing a fluoroolefin, a carboxylic acid vinyl ester-based monomer and a copolymerizable monomer containing ethylene as an essential component as the above-mentioned topcoat material (B). The coated article according to claim 3, which is contained as an essential component. 5. The article is a cement-based substrate,
The coated article according to claim 3 or 4. 6. The article according to claim 3, wherein the article is a metal plate.
Or the coated article according to 4. 7. The coated article according to claim 3, wherein the article is a wood-based material.