JP2855451B2 - Manufacturing method of ceramics - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Object of the Invention (Industrial Application Field) The present invention is to perform glazing and firing without going through a sintering step, and to simultaneously perform firing of at least green body and firing of glaze. The present invention relates to a method for manufacturing a ceramic, or a method for manufacturing a ceramic in which a pattern is transferred, fired after glazing without passing through a unglazing step, and firing of a green body, firing of a glaze, and firing of a pattern are performed simultaneously.

(Prior art) Conventionally, in the manufacture of ceramics, a green body powder for ceramics was kneaded with water to obtain a slurry, but an appropriate water-containing state was formed using molding methods such as cast molding, extrusion molding, and potter's wheel molding. A green sheet may be formed by molding to form a green body, or a green sheet may be formed from a mixture of the above-mentioned slurry and a resin aqueous emulsion, and the sheet may be dried and then formed by pressing, punching, or the like. A ceramic body was manufactured from the green body through the following steps.

Green body molded body → unglazed (sintered) → glazed → firing → ceramic products In order to manufacture painted ceramics, the unsintered (sintered) molded body is glazed with an aqueous dispersion of glaze, then 1000
After firing at ~ 1400 ° C, the pattern layer formed on the transfer paper is transferred onto it, and further fired at a temperature of 500 ~ 1400 ° C to decompose and volatilize the synthetic resin contained in the pattern layer. Except, they had painted ceramics.

The reason why the green body is fired once is that if the green body is glazed and fired as it is on the green body surface, cracks or chipping of the green body will occur during firing.

In the conventional method of manufacturing the painted ceramics described above, in addition to unglazing, two firing steps of firing a glaze and firing a pattern layer are required, which is complicated, has low thermal efficiency, and is economically disadvantageous. There was a disadvantage. As a method of improving this, after glazing on the unbaked surface of the green body molded body, a primer mainly composed of a synthetic resin emulsion or an aqueous solution of a water-soluble polymer or a mixture thereof is applied to the surface of the glaze layer, Then, there has been proposed a method in which a transfer pattern is transferred thereon, brought into close contact therewith, fired, and simultaneously firing the glaze and firing the pattern layer (Japanese Patent Publication No. 60-45073).
Although this method can omit the firing step once, the number of primer application steps increases, and the glaze layer may be damaged because a primer containing a large amount of water is applied on the glaze layer.

Also, the method of painting directly on the glaze layer before firing has the disadvantage of weakening the adhesion between the glaze layer and the pattern, and in order to improve this, a resin binder is mixed in the raw glaze And improved methods of applying a primer on the glaze layer have been proposed, but these methods also have insufficient adhesion (adhesion) between the glaze layer and the picture layer, causing the picture to float during pre-drying, resulting in pinholes. There is a drawback that the defective rate increases due to the occurrence of shrinkage or shrinkage. In addition, the method of mixing the resin binder into the raw glaze has a problem that the glaze composition mixed with the resin binder has poor storage stability.

In order to improve these drawbacks of the conventional method, the present inventors previously added a carboxyl group (-COOH) based on an α, β-unsaturated carboxylic acid to 1.4 × 10 ⁻³ to a ceramic green body.
A glaze composition blended with an anionic copolymer resin emulsion containing at a ratio of ~ 1.8 × 10 ^-2 mol is glazed, and the glaze layer is dried and solidified. Alternatively, a method has been proposed in which a glaze composition is further applied on the transfer layer and painted, followed by firing to simultaneously perform firing of the glaze and firing of the pattern (Japanese Patent Laid-Open No. 63-100094). . However, this method has a drawback that it is not easy to apply the glaze composition to the green body, and in order to improve this, the glaze composition containing the aqueous emulsion of the anionic copolymer resin is washed with a large amount of water. When diluted and glazed, the adhesion between the raw material and the glaze is reduced, and the water resistance of the glaze is reduced.

(Problems of the Invention) The present invention makes it possible to simultaneously perform at least firing of a green body and a glaze layer to reduce the occurrence of a defect rate such as breakage of the green body and to improve the adhesion between the green body and the glaze. It is an object of the present invention to provide a method for manufacturing ceramics from which excellent ceramic products can be easily obtained.

In addition, the present invention allows the firing of the green body and the firing of the glaze layer and the firing of the pattern layer at the same time, thereby reducing the occurrence of a defect rate such as breakage of the base, and, furthermore, reducing the occurrence of the base and the glaze layer or the pattern layer. It is an object of the present invention to provide a method for manufacturing a ceramic product from which a ceramic product having excellent adhesion to the ceramic can be easily obtained.

(B) Configuration of the Invention (Means for Solving the Problems) The present inventors have made various studies to solve the above-mentioned problems, and as a result, have reached the present invention.

The first method for producing ceramics according to the present invention comprises: (A) 100 parts by weight of a ceramic base powder, (B) an unsaturated monomer mixture using an anionic surfactant which forms a chelate compound with a polyvalent metal ion. Is an aqueous emulsion of a copolymer having a minimum film-forming temperature or glass transition temperature (T ¹ ) obtained by emulsion polymerization satisfying the following formula (I) and having a carboxyl group content of 0 to 0.3% by weight. And an aqueous anionic copolymer emulsion (B ¹ ) containing the anionic surfactant in a solid content ratio of 0.6 to 2.5% by weight with respect to the copolymer, a polyvalent metal ion and a chelate The film forming temperature (T ² ) obtained by emulsion polymerization of the unsaturated monomer mixture using an anionic surfactant forming a compound satisfies the following formula (II),
And an aqueous emulsion of a copolymer having a carboxyl group content of 0 to 0.3% by weight, wherein the anionic surfactant has a solid content ratio of 0.6 to 2.5 based on the copolymer.
It is a mixed emulsion with an anionic copolymer aqueous emulsion (B ² ) containing the copolymer aqueous emulsion (B ¹ ) / copolymer aqueous emulsion (B ² ) by weight. By polymer solid content weight ratio (10-45)
/ (90-55) 10 to 50 parts by weight in terms of the total solid content of the copolymer, and (C) 10 to 10 parts of an inorganic compound which forms a polyvalent metal ion in water.
100 parts by weight of the copolymer aqueous emulsion (B ¹ ) at a temperature higher than the minimum film-forming temperature or glass transition temperature (T ¹ ) of the copolymer of the copolymer aqueous emulsion (B ¹ ) Is mixed at a temperature lower than the minimum film-forming temperature (T ² ) of the copolymer to form a slurry, and the resulting slurry is filtered and dehydrated under the above temperature conditions to obtain a green body for hydrated ceramics. Forming the aquatic green body to form a ceramic molded body and then drying at a temperature exceeding the minimum film forming temperature (T ² ) of the copolymer of the aqueous copolymer emulsion, or drying the above-mentioned green ceramic body for a hydrous ceramic Is formed by heating or pressing under a temperature exceeding the minimum film forming temperature (T ² ) of the copolymer of the copolymer aqueous emulsion (B ² ), and then drying On the surface of the ceramic green body in the state, glaze and Glaze aqueous dispersion containing anion resin aqueous emulsion was calcined After glazed, a method characterized by causing at the same time the firing of the firing and glaze least greenware.

Formula (I): (Sludge temperature -45 ° C.) <T ¹ <(Sludge temperature) (I) In the formula (I), T ¹ is a copolymer emulsion (B ¹ )
When the minimum film-forming temperature of the copolymer or the minimum film-forming temperature of the copolymer is lower than the freezing temperature of the slurry, it is the glass transition temperature of the copolymer.

Formula (II): (sludge temperature) <T ² ... (II) In the formula (II), T ² is the minimum film-forming temperature of the copolymer of the copolymer aqueous emulsion (B ² ).

Further, in the second method for producing ceramics of the present invention, after the glaze aqueous dispersion layer after glazing in the first method for producing ceramics is dried and solidified, the surface is then transferred by a water slide method. A method of transferring a pattern or further applying the glaze aqueous dispersion again on the transfer surface of the pattern, followed by firing to simultaneously perform firing of the green body, firing of the glaze, and firing of the pattern. is there.

The ceramic base powder (i.e., porcelain) of the component (A) in the present invention is not essentially different from the porcelain used in the conventional porcelain manufacture. For example, SiO ₂ · Al ₂ O ₃
Is prepared by appropriately blending kaolin, clay, feldspar, mica, bentonite, talc, quartzite, etc., containing as a main component. Also, such as fired ceramic crushed products or Al ₂ O ₃
So-called new ceramic raw materials can also be used.

The aqueous anionic copolymer emulsion as the component (B) in the present invention is obtained by emulsion-polymerizing an unsaturated monomer mixture using an anionic surfactant that forms a chelate compound with a polyvalent metal ion. The minimum film formation temperature or glass transition temperature (T ¹ ) satisfies the formula (I),
And an aqueous emulsion of a copolymer having a carboxyl group content of 0 to 0.3% by weight, wherein the anionic surfactant has a solid content ratio of 0.6 to 2.5 based on the copolymer.
% By weight of an aqueous emulsion of anionic copolymer (B ¹ ) and an anionic surfactant which forms a chelate compound with a polyvalent metal ion. The film forming temperature (T ² ) is determined by the above formula (I
Satisfying (I) and having a carboxyl group content of 0 to 0.3
Aqueous emulsion of a copolymer having a solid content ratio of 0.6 to 2.5% by weight based on the weight of the copolymer, wherein B ²⁾ and a mixed emulsion, further copolymer aqueous emulsion (B ¹⁾ / copolymer aqueous emulsion (B ²⁾ mixing ratio is in the copolymer solids weight ratio of (10-45) / (90-55).

Examples of the unsaturated monomers used for producing the aqueous anionic copolymer emulsions (B ¹ ) and (B ² ) include, for example, alkyl acrylates, alkyl methacrylates (alkyl groups of these alkyl esters). Has 1 to 8), 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 2-
Hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, acrylamide, methacrylamide, methylol acrylamide, vinyl chloride, vinylidene chloride, ethylene, acrylonitrile, vinyl acetate, styrene, acrylic acid, methacrylic acid, itaconic acid, fumaric acid, crotonic acid, anhydride Maleic acid, sodium vinyl sulfonate and the like can be mentioned.

These unsaturated monomers are appropriately selected and used in combination of two or more and copolymerized to produce the aqueous anionic copolymer emulsions (B ¹ ) and (B ² ) used in the present invention.
Combined amount of the unsaturated carboxylic acid in that case, both the case of aqueous emulsion (B ¹⁾ and (B ^2), carboxyl group concentration of the formed copolymer is the ratio comprised within the range of 0 to 0.3 wt% . Further, the selection and combination of the unsaturated monomers can satisfy the above-mentioned formula (I) so that the minimum film forming temperature or glass transition temperature (T ¹ ) of the copolymer in the aqueous emulsion (B ¹ ) is satisfied. And the minimum film forming temperature (T ² ) of the copolymer of the aqueous emulsion (B ² ) can satisfy the above-mentioned formula (II).

Examples of the anionic surfactant which forms a chelate compound with a polyvalent metal ion used for producing the aqueous anionic copolymer emulsions (B ¹ ) and (B ² ) of the present invention include sodium laurate. , Organic acids such as fatty acid soda (soda soap) such as sodium stearate, sodium polyoxyethylene alkyl ether sulfate, sodium polyoxyethylene alkyl phenyl ether sulfonate, sodium alkane sulfonate, sodium alkyl benzene sulfonate, sodium alkyl diphenyl ether disulfonate Examples thereof include sodium sulfonic acid, fatty acid sarcoside, sodium rosin acid, and the like, and potassium salt, ammonium salt, alkanolamine salt and the like in place of the above various soda salts.

The anionic surfactant which forms a chelate compound with the polyvalent metal used in the production of the aqueous emulsions (B ¹ ) and (B ² ) of the present invention includes other surfactants (emulsifiers) such as Nonionic surfactants such as ethylene alkyl ether, polyoxyethylene alkyl phenyl ether, and polyoxyethylated castor oil can be used in relatively small amounts. When a small amount of these nonionic surfactants is used in combination, it is effective for stabilization during polymerization.

Examples of the inorganic compound that forms a polyvalent metal ion in water as the component (C) in the present invention include oxides, hydroxides, sulfates, carbonates, and the like of polyvalent metals such as calcium, magnesium, iron, aluminum, and strontium. Salt and the like. Specific examples thereof include inorganic compounds that dissolve in water to generate polyvalent metal ions, preferably dissolve in water little by little to slowly generate polyvalent metal ions,
Examples include gypsum, quicklime, magnesium oxide, magnesium carbonate, strontium carbonate, and the like. Among these, a calcium compound and a magnesium compound are preferable from the viewpoint of solubility and a reaction rate with an anionic surfactant.

In the present invention, the copolymer aqueous emulsion (B ¹ )
At a temperature higher than the minimum film-forming temperature or glass transition temperature (T ¹ ) of the copolymer (A) and lower than the minimum film-forming temperature of the copolymer aqueous emulsion (B ² ), The component, the component (B) and the component (C) are mixed to form a slurry, and the slurry is filtered and dehydrated under the above-mentioned temperature conditions, for example, using a method such as a filter press method or a papermaking method to obtain a water-containing state. The earthenware will be used.

In general, in the manufacture of ceramics, water is added to a ceramic base powder to make a so-called slurry having a water content of 50 to 60% by weight, which is then filtered and dewatered by a filter press or papermaking. A green body for ceramics of 20 to 30% by weight is formed and dried to obtain a green body for ceramics in a dry state. However, the drying process takes several days and the work is not efficient.

In order to perform this drying step in a short time, it has been attempted to heat and mold a dried green body for ceramic at 100 to 180 ° C., but the strength of the obtained dry molded body is weak,
There were drawbacks such as chipping or cracking, poor workability, and large shrinkage of the dried product, and the utility was poor.

In the present invention, as described above, (A) a ceramic base powder as a component, and (B) a mixed emulsion obtained by mixing two kinds of anionic copolymer aqueous emulsions (B ¹ ) and (B ² ) as a component, And an inorganic compound that forms polyvalent metal ions in water as component (C) is mixed to form a slurry. At this time, the polyvalent metal ion generated by dissolving component (C) in water is (B) ) The component acts on the anionic surfactant contained in the emulsion to form a chelate compound, inactivates the surfactant, and destroys the emulsion. The coalesced (resin) particles adhere to the ceramic powder of the component (A).

By the way, in the present invention, a mixed emulsion of two kinds of aqueous anionic copolymer emulsions (B ¹ ) and (B ² ) is used as the copolymer emulsion as the component (B), and The preparation of the slurry in the present invention is carried out at a temperature higher than the minimum film forming temperature or the glass transition temperature (T ¹ ) of the copolymer of the copolymer emulsion (B ¹ ), and the copolymer emulsion (B ² ) Temperature lower than the minimum film formation temperature (T ² ) of the copolymer (usually 0 to 40 ° C.)
In the above, the components (A) to (C) are mixed, so that the prepared slurry does not cause mutual sticking of the base powders depending on the copolymer derived from the emulsion (B ² ). . Moreover, the copolymer emulsion (B ¹ ) /
The mixing ratio of (B ² ) is (10-45) /
A (90-55), who copolymer derived from emulsion (B ²⁾ is in the amount than often copolymer derived from emulsion (B ^1).

For this purpose, in the present invention, the slurry prepared by mixing the components (A) to (C) with an appropriate amount of water under the above-mentioned temperature conditions is prepared by adding the copolymers (B ¹ ) and (B ² ) to the base powder. ) Does not coagulate into a large mass as a whole, and has an appropriate particle size (for example, several + μ or more). It can be easily filtered and dewatered by a filter press or papermaking without causing clogging. In addition, the same temperature conditions as in the above-described preparation of the slurry are used for the filtration and dehydration of the slurry. Moreover, in the present invention, the filtration and dehydration by the above-described filter press or papermaking are performed after the copolymer emulsion is destroyed by the component (C) and the copolymer is agglomerated. In addition, operations such as filtration and dehydration can be performed by using a large amount of water to lower the viscosity, and the effect that these operations can be performed efficiently can be obtained.

Instead of the method of the present invention, when a copolymer emulsion is prepared using a surfactant other than an anionic surfactant that forms a chelate compound with a polyvalent metal ion, or when a polyvalent metal ion and a chelate are used. Even when prepared using an anionic surfactant that forms a compound, when the component (C) is not mixed, the copolymer emulsion does not break during the preparation of the slurry. The slurry that is used is filtered during filtration and dewatering by filter press or papermaking, and the copolymer particles (particle size) of the emulsion
(0.05 to 3 microns) to cause clogging of the filter cloth, etc., or the particles ooze out onto the surface of the filter cloth, etc., and form a dry film on the surface, so that filtration and dewatering can be performed smoothly. Can not.

Also, if the carboxyl group content of the copolymers of the copolymer emulsions (B ¹ ) and (B ² ) is too large, the polyvalent metal ions generated from the component (C) during the preparation of the slurry may be reduced. It is consumed by the carboxyl group, and it takes a long time to break down the copolymer emulsion and agglomerate and coagulate the copolymer particles, thereby increasing the working time. Therefore, the copolymer of the copolymer emulsion (B ¹ ) or (B ² ) in the present invention has a carboxyl group content of 0%.
It should be about 0.3% by weight.

Further, the copolymer copolymer emulsion of the present invention (B ¹ )
And (B ² ) each contain an anionic surfactant in an amount of 0.6 to 2.5% by weight based on the copolymer. This is because if the proportion of the anionic surfactant is too large, the emulsion cannot be sufficiently destroyed by the component (C) during the preparation of the slurry. That is, when the proportion of the anionic surfactant exceeds 2.5% by weight, it takes a long time to coagulate and coagulate the copolymer particles due to the destruction of the emulsion during the preparation of the slurry, and depending on the constituents of the copolymer, When the slurry thus obtained is allowed to stand, a part of the copolymer emulsion separates on the precipitated hydrous ceramic green body. Since the copolymer particles contained in the emulsion separated in the upper layer are of the order of 0.03 to 3 microns, the copolymer particles are removed from the filter cloth or the like during filtration or dehydration by a filter press or the like. Cause clogging,
Oozing on the filter cloth surface and drying to form a film,
It prevents smooth filtration and dehydration.

Conversely, if the proportion of the anionic surfactant is too small, the polymerization stability at the time of preparing the copolymer emulsion becomes poor, the storage stability of the produced copolymer emulsion becomes poor, This is because, during the preparation of the soy sauce, the copolymer emulsion is rapidly destroyed, which prevents the agglomerated copolymer particles from uniformly adhering to the base powder.

In the present invention, the mixing ratio of the copolymer emulsion (B ¹ ) / copolymer emulsion (B ² ) is (10-45) / (90-55) in terms of copolymer solid content weight ratio. .
This is because if the amount of the copolymer in the copolymer emulsion (B ¹ ) becomes too large, the copolymer particles that are coagulated and precipitated during the preparation of the slurry will be degraded from the copolymer emulsion (B ¹ ). The copolymer becomes more abundant, and this copolymer shows stickiness at the temperature of slurry preparation, filtration and dehydration, so that the sludge solidifies as a large lump, and further the lump solidifies. Makes it difficult to filter and dehydrate the slurry by sticking to filter cloth and the like. Conversely, if the copolymer amount of the copolymer emulsion (B ¹ ) is too small, the green body molded product obtained by molding the dewatered slurry after filtration or papermaking will have a reduced strength and water resistance before drying. It is inferior.

Component (A) at the time of preparing the slurry in the present invention, (B)
The component and the component (C) are mixed at a ratio of 100 parts by weight of the component (A) to component (B) as a copolymer solid content of 10 parts by weight.
-50 parts by weight, and component (C) is 10-100 parts by weight.
If the amount of the component (B) is too small, the strength of the green ceramic body becomes weak, and chipping or cracking of the molded body is likely to occur. If the amount of the component (B) is too large, the emulsion may be broken. (C) A large amount of components is required, and the destruction of the emulsion is inadequate, which hinders filtration and dewatering operations of the slurry. It also causes a reduction in product strength. The component (C) is used in an amount necessary to destroy the emulsion of the component (B) and within a range that does not impair the necessary physical properties of the resulting green ceramic body. The amount thereof is in the range of 10 to 100 parts by weight per 100 parts by weight of the component (A), and preferably 0.5 to 2.5 times the amount of the emulsion of the component (B).

In preparing the slurry of the present invention, a pulverizer such as a ball mill is used in order to pulverize the ceramic body powder and mix the components (A), (B) and (C) in a sufficient and uniform manner. Can be used. In addition, a large amount of water can be added to facilitate transportation of the mixed slurry, filtration and dehydration. In addition, if necessary, a coloring agent, a dispersant,
Wetting agents, water reducing agents and the like can be added.

Next, in the present invention, the slurry prepared as described above, in which the copolymer emulsion is destroyed by the component (C), is filtered and dehydrated by a filter-less method, a papermaking method, or the like, to thereby form a water-containing ceramic. It is a bare ground. The temperature of the slurry at the time of filtration and dehydration is the same as the temperature condition at the time of preparing the slurry, that is, from the minimum film forming temperature or glass transition temperature (T ¹ ) of the copolymer of the copolymer emulsion (B ¹ ). Is maintained at a temperature lower than the minimum film formation temperature of the copolymer emulsion (B ² ).

This is to facilitate filtration of the slurry for the same reason as in the preparation of the slurry.

Next, in the present invention, a water-containing green body obtained by filtration and dehydration is formed into a water-containing ceramic green body molded body, and the water-containing green body is subjected to the minimum production of a copolymer of a copolymer emulsion (B ² ). The dried green body obtained by drying at a temperature higher than the membrane temperature (T ² ) or by drying the wet green body obtained as described above is copolymerized with the copolymer aqueous emulsion (B ² ). Using a method of heat molding at a temperature exceeding the minimum film forming temperature (T ² ) of the coalescing, a dried ceramic green body is formed.

The formation of a water-containing green body can be performed by using a suitable water-containing ceramic green body obtained by filtration and dehydration by a potter's wheel method, an extrusion molding method, a casting molding method, a room temperature press molding method, or the like. It can be carried out by press forming, punching or the like from a hydrous green sheet obtained by filtration or papermaking.

The heating and pressing molding method using the above-mentioned temperature conditions is used for forming the dried green body.

The molded body obtained by molding the above-mentioned green body in a water-containing state is based on the adhesive force (adhesive force) of the copolymer derived from the copolymer emulsion (B ¹ ) and the plasticity of the ceramic body powder itself, It has moderate initial strength and water resistance, and prevents breakage and breakage of the molded body before drying. Further, by heating the water-containing molded body using hot air, far-infrared rays, high frequency, or the like, at a temperature higher than the minimum film-forming temperature of the copolymer of the copolymer emulsion (B ² ), the resulting dried product is obtained. The strength of the molded body is increased by the adhesive force (fusion force) of the copolymer whose base particles are derived from the copolymer emulsion (B ² ), so that the strength and water resistance of the dried molded body are further improved. . Further, a dry molded product obtained by heating and pressing the dried green body under the above-mentioned temperature conditions also has excellent strength and water resistance for the same reason.

Next, in the present invention, an aqueous glaze dispersion containing a glaze and an aqueous anionic resin emulsion is applied to the surface of the dried ceramic green body molded body obtained as described above. The aqueous dispersion of the glaze is preferably one obtained by mixing 4 to 20 parts by weight of an aqueous anionic resin emulsion as a resin solid content with 100 parts by weight of the glaze.

As the glaze, various glazes such as transparent glaze, color glaze, crystal glaze according to property classification, lead glaze, flint glaze, Bristol glaze according to component classification, or pottery glaze or porcelain glaze according to use classification can be used.

As an example, the composition of the porcelain glaze of SK13 is as follows.

Feldspar 73.57% by weight Magnesite 5.35 〃 Limestone 0.87 〃 Kaolin 5.68 〃ishi E. 14.53 Total 100% by weight Also, the preferred aqueous anionic resin emulsion used for preparing the aqueous glaze dispersion has the following composition: 100 parts by weight of the unsaturated monomer mixture, anionic emulsifier 0.1
It is a copolymer resin emulsion obtained by emulsion polymerization in the presence of up to 5 parts by weight and 0 to 5 parts by weight of a nonionic emulsifier.

(A) 0.3 to 10% by weight of a hydroxyl group-containing unsaturated monomer (b) Alkyl acrylate (alkyl group having 2 to 8 carbon atoms) 40 to 55〃 (c) Monomer selected from methyl methacrylate and acrylonitrile (D) Monomer selected from N-phenylmaleimide, N-methylolacrylamide, acrylamide and methacrylamide 1 to 10〃 (e) Other monomer 0 to 20〃 The above (a) ) As monomers, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate,
Examples include acrylates such as pentaerythritol tetraacrylate and diethylene glycol monoacrylate, methacrylates thereof, and allyl alcohol. These are used in an amount of 0.3 to 10% by weight based on the monomer mixture from the viewpoints of storability, dispersibility, adhesion, and water resistance.

Further, the acrylic alkyl ester of the monomer (b) is
Soft monomers that impart flexibility to the film, such as ethyl acrylate, isopropyl acrylate, n-butyl acrylate, t-butyl acrylate, n-propyl acrylate, 2-ethylhexyl acrylate, and the like.

The monomer (c) is a hard monomer that gives the film a toughness. Some of this monomer can be replaced by ethyl methacrylate, isopropyl methacrylate, isobutyl methacrylate.

Further, (d) the monomer has an adhesive property with a ceramic base powder,
And for imparting dispersibility.

Examples of the monomer (e) include unsaturated carboxylic acids such as acrylic acid, methacrylic acid, itaconic acid, and maleic anhydride, styrene, ethylene, and butadiene.
The amount of the unsaturated carboxylic acid used is 8 × in the copolymer.
The ratio is 10 ^-3 to 8 × 10 ^-4 mol or less.

The copolymer emulsions (B ¹ ) and (B ² ) used for the component (B) in the present invention, and mixtures thereof,
It can be used as an aqueous emulsion of anionic resin for the aqueous glaze dispersion of the present invention.

The aqueous anionic resin emulsion for the aqueous glaze dispersion of the present invention has a minimum film forming temperature of 10 from the viewpoints of good film formation of the glaze layer, hardness of the film, and prevention of contamination due to stickiness of the film. Emulsions of resins above ℃ are preferred.
In addition, this aqueous anionic resin emulsion is added with a water-soluble pyrophosphate and / or tripolyphosphate in an amount of 0.05 to 100 parts by weight of the resin solid content of the emulsion in order to increase the viscosity and prevent gelation when mixing the glaze. It is desirable to incorporate them in a proportion of up to 5 parts by weight. It is desirable that each of these phosphates is added to the polymerization system during emulsion polymerization for producing an aqueous anionic resin emulsion and emulsion polymerization is carried out, but may be added later to the emulsion after polymerization. Specific examples of the phosphate include a soda salt, a potassium salt, and an anmonium salt of pyrophosphoric acid or tripolyphosphoric acid.

The aqueous anionic resin emulsion added to the aqueous glaze dispersion of the present invention adjusts the viscosity of the aqueous glaze dispersion, improves the water resistance of the glaze layer, and transfers the pattern to the glaze layer by the water slide method. Prevents glaze layer collapse when overlaying glaze onto the transferred picture layer, controls the penetration of glaze components into the green body by emulsion particles, improves the strength of glaze layer by emulsion resin film, molding after glazing It has various functions and effects such as protection of the glaze layer such as prevention of the glaze surface from being scratched or peeled off during body movement and work, and improvement in adhesion between the glaze layer and the picture layer.

Various methods can be used for preparing the glaze aqueous dispersion of the present invention. A typical preparation method is to add an appropriate amount of water and a dispersant to 100 parts by weight of a glaze, mix with a ball mill, then blend 4 to 20 parts by weight of an anionic resin aqueous emulsion (resin solid content), If the aqueous resin emulsion does not contain pyrophosphate or tripolyphosphate, add 0.05 to 5% by weight of pyrophosphate or tripolyphosphate to the solid content of the resin, and further add an antifoaming agent if necessary. And a dispersant are added and mixed to form an aqueous glaze dispersion having a water content of 25 to 65% by weight.

The glazing in the present invention is performed by applying the above-mentioned aqueous dispersion of glaze on the surface of the dried green ceramic body obtained as described above. As the glaze method, there are methods such as spraying, dipping, and pouring. If the glaze is applied by such a method, a raw glaze layer is formed on the surface of the green body.

If the raw glaze layer after glazing is dried and solidified and then fired without painting, firing of the green body and firing of the glaze are performed at the same time to obtain a glazed ceramic. In addition, after the raw glaze layer is dried and solidified, it is painted by an appropriate method, and if necessary, reglazed on the pattern surface, and the raw glaze layer is dried and solidified, and then fired. The firing of the base, the firing of the glaze, and the firing of the pattern are performed simultaneously, and the desired painted ceramic is obtained.

A particularly preferred painting method in the present invention is to dry and solidify a raw glaze layer after glazing, and then transfer a transfer pattern thereon by a water slide method, or again to the glaze on the transfer surface of the pattern. This is a method in which the aqueous dispersion is overcoated.

The transfer paper used in this case is formed by applying a water-soluble polymer on the paper surface, forming a pattern layer on which a pattern is printed with an ink obtained by mixing a pigment with a synthetic resin, and further reinforcing the synthetic resin thereon. It is provided with a layer. When such transfer paper is immersed in water, the water-soluble polymer dissolves and the pattern layer is peeled off from the paper together with the reinforcing layer. This is transferred to the dried and solidified glaze layer. This method is generally called a water slide method. At this time, the picture layer is transferred onto the glaze layer surface with a large amount of water attached thereto, but the glaze layer is distorted because the resin component of the synthetic resin emulsion imparts water resistance. It can be reliably prevented. This effect can also be obtained when a picture glaze is applied directly on the glaze layer instead of transferring the picture by the water slide method. As the synthetic resin for reinforcing the pigment of the transfer paper for painting, the same anionic resin aqueous emulsion as used in the aqueous glaze dispersion can be used.

After the painting, firing is performed at a temperature equal to or higher than the melting temperature of the glaze after drawing or adding a pattern in order to enhance the finish of the ceramic as required. During the firing, all of the resin and the surfactant in the emulsion are decomposed and volatilized, and the firing of the green body, the firing of the glaze, and the firing of the pattern are performed at the same time, and a ceramic with a picture is obtained.

(Examples, etc.) Hereinafter, the production examples, examples, and comparative examples of the anionic copolymer emulsion will be described in more detail. In these examples, parts and% described mean parts by weight and% by weight unless otherwise specified.

Production Example 1 of Anionic Copolymer Emulsion A mixture of the following water and emulsifier was charged into a reaction vessel equipped with a temperature controller, an immersion type stirrer, a reflux condenser, a supply vessel, a thermometer, and a nitrogen inlet tube.

200 parts of water 30% aqueous solution of sodium salt of sulfuric acid half ester of p-nonylphenol (anionic emulsifier) reacted with 20 moles of ethylene oxide 5 parts of p-nonylphenol (nonionic emulsifier) reacted with 25 moles of ethylene oxide 20 parts of a 20% solution Then, after replacing the inside of the reaction vessel with nitrogen gas, 10% of the following feed I was added and heated to 90 ° C.

Feed I: water 200 parts 30% aqueous solution of the anionic emulsifier described above 25 parts Methyl methacrylate 195 parts N-butyl acrylate 189 parts 2-hydroxypropyl acrylate 8 parts Acrylamide 8 parts Further, 2.5 parts in 85 parts of water After charging 10% of the solution of potassium persulfate (Feed II) into the reaction vessel, all of the remaining Feed I and all the remaining Feed II were treated with 3.5%.
Supply into the reaction vessel over a period of time
Feed I was polymerized at a temperature of 0 ° C. to obtain an aqueous emulsion of anionic copolymer.

Production Example 2 of Anionic Copolymer Emulsion In the same reaction vessel as in Production Example 1, the same mixture of water and emulsifier as used in Production Example 1 was supplied.

Next, after the inside of the reaction vessel was replaced with nitrogen gas, 10% of the following feed I was added, and the mixture was heated to 90 ° C.

Feed I: Water 200 parts 30% aqueous solution of anionic emulsifier used in Production Example 1 25 parts Acrylic acid 2 parts Methyl methacrylate 195 parts N-butyl acrylate 195 parts Acrylamide 8 parts Further, 1.25 parts in 42.5 parts of water Of potassium persulfate and 1 part of sodium pyrophosphate (Feed II)
Is charged into the vessel, and the entire remaining feed I and all the remaining feed II are fed into the vessel over 3.5 hours. After the feed is completed, the feed I is polymerized at 90 ° C. for 2 hours. Thus, an anionic copolymer aqueous emulsion was obtained.

Production Examples 3 to 12 of Anionic Copolymer Emulsions The types and amounts of unsaturated monomers and the types and amounts of emulsifiers were changed as shown in Table 1, and other copolymers were prepared according to Production Example 1 described above. An aqueous emulsion was prepared.

The physical properties of the anionic copolymer emulsion obtained in each of the above Production Examples were as shown in Table 1.

Example 1 1500 parts of water was added to 1000 parts of porcelain clay composed of 60 parts of feldspar, 470 parts of porcelain stone, 100 parts of silica stone, 200 parts of Frogme clay and 170 parts of Kibushi clay, and then the mixture was subjected to a ball mill at a temperature of 20C. And milled for 20 minutes to obtain a mixed slurry, which is further mixed with the anionic copolymer emulsion obtained in Production Example 1 (minimum film forming temperature of 18).
75 ° C.), 175 parts of the anionic copolymer emulsion obtained in Production Example 3 (minimum film-forming temperature 43 ° C.), and β-gypsum 2
50 parts were added, and the mixture was further pulverized with a ball mill for 1 hour to obtain a slurry of porcelain clay particles to which the copolymer particles had adhered. Even when this slurry was allowed to stand, no separation of the copolymer emulsion was observed.

This slurry was filtered under reduced pressure at 25 ° C. under a reduced pressure of 500 mmHg to obtain a green body for ceramics having a water content of about 20%. There was no clogging of the filter cloth when filtering the slurry.

Then, the green body dried at 30 ℃ or less,
It was placed in a press mold and molded by heating and pressing at 100 ° C. under a pressure of 20 kg / cm ² to obtain a 5 mm-thick 150 mm × 150 mm plate-like green body. It was hard, with no cracks or chips and little shrinkage.

Next, 100 parts of water was added to 100 parts of commercially available white glaze, and pulverized by a ball mill (solid content: about 58%, pH 9.3). This dispersion glaze liquid 1
10 parts by weight of the anionic resin emulsion obtained in Production Example 3 (minimum film-forming temperature of 43 ° C.) was mixed with 00 parts by weight to obtain an aqueous glaze dispersion. The aqueous dispersion of the glaze did not show any increase in viscosity or formation of aggregates even when left at room temperature for 24 hours.

Next, the surface of the green body molded body was spray-coated with the aqueous dispersion of the glaze, preliminarily dried at 150 ° C.,
After transferring the picture layer printed on the transfer paper to the surface of the glaze layer by the water slide method, the painted
Firing at ℃ (glaze firing) to obtain a clear ceramic plate with a picture. This ceramic plate had high strength without chipping or cracking.

Comparative Example 1 The temperature of the filtrate at the time of filtration in Example 1 was changed to the minimum film formation temperature of the copolymer of the emulsion obtained in Production Example 3 (43
When the temperature was raised to 55 ° C, which was higher than (° C), the raw green powder for ceramics fused and became a lump. Further, the slurry obtained in Example 1 was gradually heated to 55 ° C.
When the temperature was raised to about 45 ° C., thickening was observed from about 45 ° C.

Example 2 When CaSO ₄ , MgO or MgCO ₃ was used instead of β-gypsum as the emulsion breaking agent used in Example 1,
None of the filter cloths clogged when filtering the slurry.

Examples 3 to 5 Comparative Examples 2 to 3 The total amount of the copolymer emulsion and the amount of β-gypsum relative to 1000 parts of the ceramic base powder in Example 1 were changed as shown in Table 2, and the others were used. In the same manner as in Example 1, a green compact for a ceramic plate was produced. The results were as shown in Table 2.

Example 6 75 parts of the copolymer emulsion obtained in Production Example 4 (minimum film-forming temperature of 19 ° C.) and 75 parts of the copolymer emulsion obtained in Production Example 6 (minimum film-forming) were added to 1000 parts by weight of a tile powder. Temperature 63
275 parts), and water was further added, followed by grinding with a ball mill for 20 hours. Next, 300 parts of MgO was added, and the mixture was further mixed and pulverized at 30 ° C. with a ball mill, and then filtered at 30 ° C. using a filter press to obtain a hydrous green body having a water content of about 22%. Next, this hydrous green body was molded under pressure at a pressure of 20 kg / cm ² , and the molded body was heated and dried at 80 ° C. to obtain a copolymer derived from the emulsion obtained in Production Example 6. A film was formed, and a dried and solid tiled green body was obtained.

Next, 150 parts of water was added to 100 parts of a commercially available frit glaze, and the mixture was crushed with a ball mill. Then, 20 parts of the copolymer emulsion obtained in Production Example 8 (minimum film forming temperature of 18 ° C.) was blended with the mixture. A dispersion was obtained.

The glaze dispersion was spray-coated on the surface of the dried tiled green body, dried at 120 ° C., and fired at 900 ° C. to obtain a crack-free tile.

Example 7 Instead of 300 parts of MgO in Example 6, 100 parts of MgO and β-
A crack-free tile was obtained in the same manner as in Example 6 except that a mixture of 200 parts of gypsum was used.

Examples 8 to 12 Comparative Examples 4 to 16 Porcelain green body molded articles were produced in the same manner as in Example 1 except that the slurry compositions shown in Table 3 were used and the pressure molding temperatures shown in Table 3 were used.

Next, the surface of the green body was coated with an aqueous glaze dispersion having the composition shown in Table 3, and the glaze layer was dried, painted, and fired in the same manner as in Example 1. The physical properties of the obtained ceramic were as shown in Table 3.

In addition, the stability of the glaze aqueous dispersion described in Table 3 was measured and evaluated by the following method.

The storage stability was evaluated by maintaining the aqueous dispersion of glaze (glaze + copolymer emulsion) at 50 ° C. for 30 days and then returning the solution to 20 ° C. according to the following criteria.

○: No change. Viscosity 500 cps or less. No tsubu content.

×: Gelation. The system solidifies and does not return to its original state even after stirring.

The freeze stability was evaluated by adding the copolymer emulsion to the glaze, sealing the container in a container, keeping it at -5 ° C for 20 hours, and returning it to room temperature for 3 hours. did.

○: No change.

×: Aggregated.

Notes in Table 3: * 1: The copolymer is lacking in the papermaking process because it has no tackiness.
Also, it has low strength and is easy to chip when pressed at 100 ° C.

(C) Effects of the present invention In the present invention, an excellent green body for ceramics can be efficiently produced, and the obtained green body is glazed without undergoing a sintering step. At the same time, or simultaneously firing the raw substrate, firing the glaze, and firing the pattern, damage the substrate, poor adhesion between the substrate and the glaze layer,
The occurrence of defective products such as poor adhesion between the base material, the glaze layer and the picture layer is remarkably reduced, and an excellent ceramic product can be advantageously manufactured with improved efficiency such as thermal efficiency.

Claims (3)

(57) [Claims] 1. An emulsion polymerization of an unsaturated monomer mixture using (A) 100 parts by weight of a ceramic base powder, and (B) an anionic surfactant which forms a chelate compound with a polyvalent metal ion. An aqueous emulsion of a copolymer having a minimum film-forming temperature or glass transition temperature (T ¹ ) satisfying the following formula (I), and having a carboxyl group content of 0 to 0.3% by weight; An aqueous anionic copolymer emulsion (B ¹ ) containing a surfactant in a solid content ratio of 0.6 to 2.5% by weight based on the copolymer, and an anionic interface forming a chelate compound with a polyvalent metal ion The film forming temperature (T ² ) obtained by emulsion polymerization of the unsaturated monomer mixture using an activator satisfies the following formula (II),
And an aqueous emulsion of a copolymer having a carboxyl group content of 0 to 0.3% by weight, wherein the anionic surfactant has a solid content ratio of 0.6 to 2.5 based on the copolymer.
It is a mixed emulsion with an anionic copolymer aqueous emulsion (B ² ) containing the copolymer aqueous emulsion (B ¹ ) / copolymer aqueous emulsion (B ² ) by weight. By polymer solid content weight ratio (10-45)
/ (90-55): 10-50 parts by weight in terms of the total solid content of the copolymer, and (C) an inorganic compound which forms a polyvalent metal ion in water.
100 parts by weight of the copolymer aqueous emulsion (B ¹ ) at a temperature higher than the minimum film-forming temperature or glass transition temperature (T ¹ ) of the copolymer of the copolymer aqueous emulsion (B ¹ ) Is mixed at a temperature lower than the minimum film-forming temperature (T ² ) of the copolymer to form a slurry, and the resulting slurry is filtered and dehydrated under the above temperature conditions to obtain a green body for hydrated ceramics. Forming the aquatic green body to form a ceramic molded body and then drying at a temperature exceeding the minimum film forming temperature (T ² ) of the copolymer of the aqueous copolymer emulsion, or drying the above-mentioned green ceramic body for a hydrous ceramic Is formed by heating or press molding at a temperature exceeding the minimum film forming temperature (T ² ) of the copolymer of the aqueous copolymer emulsion (B ² ), and then drying On the surface of the ceramic green body in the state, glaze and Glaze aqueous dispersion containing anion resin aqueous emulsion by firing After glazing, the manufacturing method of the ceramic, characterized in that to perform simultaneously the firing of firing and glaze least greenware. Formula (I): (Plasma temperature-45 ° C.) <T ¹ <(Plasma temperature) (I) In the formula (I), T ¹ is the minimum of the copolymer of the copolymer emulsion (B ¹ ). When the film forming temperature or the minimum film forming temperature of the copolymer is lower than the freezing temperature of the slurry, it is the glass transition temperature of the copolymer. Formula (II): (sludge temperature) <T ² ... (II) In the formula (II), T ² is the minimum film-forming temperature of the copolymer of the copolymer aqueous emulsion (B ² ). 2. The method according to claim 1, wherein the glaze aqueous dispersion layer after the glaze is dried and solidified, and then a transfer pattern is transferred onto the surface thereof by a water slide method, or further the transfer of the transfer pattern is performed. 2. The production method according to claim 1, wherein said glaze aqueous dispersion is applied again on the transfer surface, followed by firing, whereby firing of the green body, firing of the glaze and firing of the pattern are performed simultaneously. 3. The aqueous dispersion of glaze according to claim 1, wherein the aqueous dispersion of glaze is an aqueous dispersion obtained by mixing 4 to 20 parts by weight of a resin solid content with 100 parts by weight of glaze. Method of manufacturing ceramics.