JP4914513B2 - Tile glaze - Google Patents

Description

  The present invention relates to a glaze used for roof tiles, and is excellent in fluidity and viscosity stability of a liquid as a glaze, and further excellent in adhesion to a roof tile base material, adhesion amount stability, drying property, and the like. It relates to glaze for tiles.

  When manufacturing tiles, tiles, ceramics, etc., by covering the surface with glaze, the surface of the substrate is made impermeable to liquids and gases, and by covering the surface of the substrate and acting as a film, it gives aesthetics. At the same time, the strength can be improved.

  In general, glaze is a mixture of a glaze material such as frit, feldspar, clay and calcium carbonate with additives such as glue and water. In order to increase the fluidity of the liquid and the adhesion to the substrate, Carboxymethylcellulose (hereinafter referred to as CMC) is used as a paste. However, since the CMC rots and storage stability deteriorates when the outside air temperature rises, it is necessary to use a preservative in combination. However, since the preservative used at that time is a chlorine-based or bromine-based organic compound, there are concerns about the effects on the human body and the environment. Furthermore, since germs that can be applied to preservatives grow in the long term, it is difficult to use the preservatives on a regular basis.

  For this reason, from the viewpoint that it is not necessary to use a preservative in combination, various synthetic polymers have been investigated as glaze pastes as alternatives to CMC. For example, Patent Document 1 discloses a copolymer composed of (meth) acrylamide and (meth) acrylate, such as 2-acrylamido-2-methylpropanesulfonic acid (salt) and alkyl (meth) acrylate. The copolymerization of esters is also described. However, there is no disclosure of the specific composition ratio or the like, and when a copolymer composed of (meth) acrylamide and (meth) acrylate is used, the fluidity of the liquid as a glaze is insufficient.

  Patent Document 2 discloses a glaze agent using a combination of a saccharide and an acrylamide polymer, and also describes 2-acrylamido-2-methylpropanesulfonic acid (salt) as a monomer of the acrylamide polymer. However, since the combined use of saccharides is essential, there is a problem that the application range is limited. In addition, when an acrylamide homopolymer is used, the fluidity of the liquid as a glaze is insufficient.

  Furthermore, Patent Document 3 discloses a modified polyvinyl alcohol based on polyvinyl alcohol, and a glaze agent in which 2-acrylamido-2-methylpropanesulfonic acid (salt) is introduced by Michael addition. Although it is improved as compared with the dispersants of Patent Document 1 and Patent Document 2, the long-term fluidity of the liquid as a glaze is still insufficient.

  As described above, glazes using the synthetic polymers described in Patent Documents 1, 2, and 3 as glazes are not sufficient in fluidity and viscosity stability of the liquid, and have adhesion and adhesion to the substrate. It is difficult to achieve a balance between quantity stability and drying property, which is not sufficiently satisfactory for practical use.

JP-A-52-139111 Japanese Patent Laid-Open No. 54-73812 JP-A-9-225284

  The present invention is excellent for fluidity and viscosity stability of a liquid as a glaze, excellent in adhesiveness to a base material, adhesion amount stability and drying property, and for roof tiles having little surface condition after firing. The purpose is to provide glaze. In addition, the glaze in this invention has the characteristics in the water-soluble polymer which is contained in a glaze and expresses the function as a paste.

  As a result of intensive studies to solve the above problems, the present inventors have found that a water-soluble polymer containing (meth) acrylamide and 2-acrylamido-2-methylpropanesulfonic acid and / or a salt thereof is a glaze paste. As a result, it was found that an excellent function was exhibited, and the present invention was completed.

  That is, the roofing glaze according to claim 1 is (meth) acrylamide: 50 to 95 mass%, 2-acrylamido-2-methylpropanesulfonic acid and Or a salt glaze formed by mixing a water-soluble polymer obtained by polymerizing a monomer mixture containing 5 to 50% by mass of a salt thereof and a glaze raw material.

  The glaze glaze according to claim 2 is the glaze glaze according to claim 1, wherein the ratio of the water-soluble polymer in the glaze is 0.1 to 2.0 mass%.

  The glaze glaze according to claim 3, wherein the Brookfield viscosity of a 10% by mass aqueous solution of the water-soluble copolymer is 100 to 50,000 mPa · s. The glaze for roof tiles.

  The glaze glaze of the present invention has a stable fluidity even when stored for a long period of time, and is also excellent in adhesion to the roof tile, stability of adhesion amount, and drying properties.

  This invention is a glaze for tiles which mixes a specific water-soluble polymer and a glaze raw material.

  The essential monomer constituting the water-soluble polymer used in the present invention is (meth) acrylamide and 2-acrylamido-2-methylpropanesulfonic acid and / or a salt thereof.

  2-Acrylamido-2-methylpropanesulfonic acid may be used in an unneutralized state as a sulfonic acid group, but it can be used with sodium hydroxide, potassium hydroxide, sodium carbonate, alkylamine, alkanolamine, etc. It may be used in a combined form. Further, after the polymerization in the sulfonic acid state, the sulfonic acid group may be neutralized with the alkali or the like. In addition, it is preferable to neutralize using sodium hydroxide from the point which can be used universally and the simplicity of handling.

  The ratio of (meth) acrylamide and 2-acrylamido-2-methylpropanesulfonic acid and / or salt thereof is in the range of 50 to 95: 5 to 50, preferably 60 to 90:10 to 40, More preferably, it is 75-85: 15-25.

  If the proportion of (meth) acrylamide is less than 50% by mass, a polymer having a high degree of polymerization may not be obtained, which is not preferable. Conversely, if the amount of (meth) acrylamide exceeds 95% by mass, it tends to be affected by expensive metals contained in the glaze raw material, which may be inferior in storage stability.

  On the other hand, when the ratio of 2-acrylamido-2-methylpropanesulfonic acid and / or a salt thereof exceeds 50% by mass, excellent characteristics such as drying property and adhesiveness may be lost, which is not preferable.

  In the water-soluble copolymer in the present invention, a vinyl monomer other than (meth) acrylamide and 2-acrylamido-2-methylpropanesulfonic acid and / or a salt thereof is used as long as the water solubility is not impaired. It may be used in the range of less than 30% by mass of the whole.

Examples of other vinyl monomers include (meth) acrylic acid, styrene, alkyl vinyl ether, vinylidene chloride, (meth) acrylic acid esters, N-vinylformamide, N-vinylacetamide, vinyl acetate, vinylpyrrolidone, ( Examples include meth) acrylonitrile, maleic acid, fumaric acid, itaconic acid, and esters thereof.
Among these, (meth) acrylic acid alkyl ester having 1 to 8 carbon atoms of alkyl) has the effect of imparting oily properties to the water-soluble polymer in the present invention and improving the stability of the glaze. Therefore, it is preferable to use them together.
When the amount of the other vinyl monomer exceeds 30% by mass, it is not preferable because the water solubility of the polymer may be inhibited.

In the water-soluble polymer of the present invention, a crosslinkable monomer can be used as another monomer. Examples of the crosslinkable monomer include polyalkenyl polyether monomers and polyvalent vinyl monomers. Specifically, tetraallyloxyethane, pentaerythritol tetraallyl ether, pentaerythritol triallyl ether, Pentaerythritol diallyl ether, allyl saccharose, trimethylolpropane diallyl ether, trimethylolpropane triallyl ether, ethylene glycol diallyl ether, glyceryl diallyl ether, glyceryl triallyl ether, triallyl isocyanurate, allyl acrylate, allyl methacrylate, diallyl phthalate , Ethylene glycol diacrylate, polyethylene glycol diacrylate, ethylene glycol dimethacrylate and polyethylene glycol di Methacrylate and the like.
When a crosslinkable water-soluble polymer using a crosslinkable monomer is used, thixotropy is developed, so that precipitation of the glaze raw material is suppressed, and improvement in the fluidity and stability of the glaze can be expected.

  The amount of the crosslinkable monomer used depends on the thickening properties of the resulting water-soluble crosslinkable copolymer, but is preferably 2.0 parts by mass or less based on 100 parts by mass of the total monomers. Preferably it is 1.0 mass part or less. If the crosslinkable monomer exceeds 2.0 parts by mass, the resulting polymer may not be water-soluble, or in some cases, the aqueous solution may not thicken even when dissolved in water.

The water-soluble polymer in the present invention is produced by polymerizing the monomer with a general radical polymerization initiator. As the radical polymerization initiator, a compound selected from peroxides and azo initiators or a mixture thereof can be used. Examples of the radical initiator include benzoyl peroxide, lauroyl peroxide, and t-butyl hydroperoxide. , Organic peroxides such as di (2-ethylhexyl) peroxydicarbonate, sodium persulfate, potassium persulfate, and ammonium persulfate.
Examples of the azo initiator include 2,2′-azobisisobutyronitrile, 4,4′-azobis-4-cyanovaleric acid, 2,2′-azobis (2-amidinopropane) dihydrochloride, and the like. These can be used alone or in combination of two or more.

It is preferable that the usage-amount of a radical polymerization initiator is 0.001-2.0 mass parts with respect to 100 mass parts of all the monomers, More preferably, it is 0.02-1.0 mass part.
If the radical polymerization initiator is less than 0.001 part by weight, the polymerization reaction may not proceed and a large amount of unreacted monomer may remain.
On the other hand, if the radical polymerization initiator is used in an amount of more than 2.0 parts by mass, the polymerization proceeds rapidly, so that the polymerization reaction is difficult to control, and in some cases, the control may not be possible. Even if the polymerization reaction can be controlled, since the polymer chain is shortened, the viscosity of the thickened aqueous solution tends to be low.

The water-soluble polymer in the present invention is preferably obtained by aqueous solution polymerization or precipitation polymerization in a water-soluble organic solvent.
Aqueous solution polymerization is a method in which water is used as a medium. Polymerization heat is easy to control, chain transfer does not occur, the degree of polymerization tends to increase, and the use of a chain transfer agent such as isopropyl alcohol increases the degree of polymerization. There are advantages such as easy adjustment.

  On the other hand, in the case of precipitation polymerization, the control of polymerization is complicated, but there is an advantage that a powdery polymer can be easily obtained by filtration and drying after the completion of the polymerization step.

  In the case of precipitation polymerization in a water-soluble organic solvent, a solvent that dissolves the monomer but does not dissolve the polymer is used. A known organic solvent can be used as the water-soluble organic solvent, and examples thereof include ketones, esters, alcohols, and the like, and an organic solvent composed of at least one of these is used.

  In addition, it is preferable to use one kind of organic solvent from the viewpoint of recovering and reusing the used organic solvent, and methanol is preferable from the viewpoint of availability from the market and relatively little chain transfer. The use of a solvent with less chain transfer makes the polymer chain longer, and generally a high-viscosity water-soluble polymer can be produced.

In the case of precipitation polymerization in a water-soluble organic solvent, after removing the water-soluble organic solvent by filtration or centrifugation, the water-soluble organic solvent is further removed by heat to obtain a powder.
In the case of aqueous solution polymerization, the polymerization solution can be easily obtained by spray drying, drum dryer drying or the like.

  When the water-soluble polymer is supplied as an aqueous solution, it is preferable to use a powder state since the amount of the water-soluble polymer must be determined in terms of solid content when blended. On the contrary, since it is necessary to redissolve in the powder state, it may be preferable to supply it in a water-soluble type. Depending on the actual manufacturing conditions of the glaze composition, You can choose whether to use in the state.

  The Brookfield viscosity of a 10% by mass aqueous solution of the water-soluble polymer in the present invention is preferably 100 to 50,000 mPa · s. More preferably, it is 1,000-20,000 mPa * s. In a water-soluble polymer having a Brookfield viscosity of less than 100 mPa · s in a 10% by mass aqueous solution, the viscosity of the resulting glaze is low, so that the fluidity of the liquid is difficult to obtain. On the other hand, in the case of a water-soluble polymer exceeding 50,000 mPa · s, the viscosity of the glaze composition becomes too high, and there is a possibility that it cannot be uniformly applied to the roof tile base material.

As a glaze raw material which is a main component of the glaze glaze of the present invention, a commonly used glaze raw material can be applied.
For example, a glaze material comprising leaded frit, silica powder, kaolin, alumina powder, titanium oxide, zirconium silicate, vanadium oxide, manganese dioxide, iron oxide, etc., as described in the examples of JP-A-7-242477 Is exemplified.
There is no restriction | limiting about the mixture ratio of these glaze raw materials, and it mix | blends timely according to the color tone, gloss, etc. of the tile which is a final product.

In the glaze in this invention, it is preferable that the addition part of a water-soluble polymer is 0.01-5.0 mass parts with respect to 100 mass parts of glaze raw materials, More preferably, it is 0.1-2.0 mass parts. It is.
If the added amount of the water-soluble polymer is less than 0.01 parts by weight, the fluidity of the liquid as a glaze, the prevention of sedimentation, the adhesiveness, the stability of the adhesion amount, etc. may not be sufficiently expressed, 5.0 mass If it exceeds the part, the viscosity may be too high.

  In the roofing glaze of the present invention, other pastes can be used in combination, such as (meth) acrylic acid polymer, (meth) acrylamide polymer, polyethylene oxide, sodium alginate, CMC, HEC (hydroxyethyl cellulose), etc. It is possible to use the dispersing material used in the above.

  In addition, as a method of mixing the glaze raw material and the paste in the present invention, a method of mixing and pulverizing with a ball mill and a plunger generally used for glaze production can be applied, and there is no particular limitation.

Hereinafter, the present invention will be described more specifically with reference to Examples and Comparative Examples.
<Production of water-soluble polymer>
<Production Example 1>
800 g of ion-exchanged water was added to a 2-liter four-necked flask equipped with a Mr. Dibroth cooler, a thermometer, a nitrogen gas blowing tube and a stirring blade, and the temperature was raised to 82 ° C. Nitrogen was blown from the bottom at a flow rate of 2 L / hour for 1 hour, and then 0.6 g of 2,2′-azobis (2-amidinopropane) dihydrochloride was added, and acrylamide was immediately added to 300 g of ion-exchanged water in advance. 275 g of 2-acrylamido-2-methylpropanesulfonic acid (referred to as ATBS) in an aqueous monomer solution and 2.4 g of 2,2′-azobis (2-amidinopropane) in 30 g of ion-exchanged water in advance. ) The catalyst aqueous solution in which the dihydrochloride was dissolved was continuously added over 4 hours.
During the polymerization, nitrogen blowing at 0.2 L / hour was continued. After completion of continuous charging, the mixture was aged at 82 ° C. for 2 hours. Further, 0.1 g of 2,2′-azobis (2-amidinopropane) dihydrochloride was added as an additional catalyst, and then aged at 82 ° C. for 3 hours. After cooling to 30 ° C. or lower, sodium hydroxide in the same molar amount as ATBS was slowly added so that the internal temperature did not exceed 40 ° C. to obtain a water-soluble copolymer aqueous solution.
The obtained copolymer is a copolymer of 91% by mass of acrylamide and 9% by mass of sodium 2-acrylamido-2-methylpropanesulfonate.
The obtained water-soluble copolymer aqueous solution was dried with a 4 inch φ small drum dryer (surface temperature 150 ° C.) and further pulverized to obtain a water-soluble copolymer powder.

<Production Example 2>
Polymerization was carried out in the same manner as in Production Example 1 except that 240 g of acrylamide and 60 g of 2-acrylamido-2-methylpropanesulfonic acid were used as monomers, and 78% by mass of acrylamide and 2-acrylamido-2-methylpropanesulfone were obtained. A copolymer of 22% by mass of sodium acid salt was obtained.

<Production Example 3>
As monomers, 180 g of acrylamide and 120 g of 2-acrylamido-2-methylpropane sulfonic acid were used, and 0.15 g of initial 2,2′-azobis (2-amidinopropane) dihydrochloride was used. , 2′-azobis (2-amidinopropane) dihydrochloride was used in the same manner as in Production Example 1 except that 0.45 g was used, and acrylamide 58% by mass and sodium 2-acrylamido-2-methylpropanesulfonate 42 A mass% copolymer was obtained.

<Production Example 4>
As monomers, 165 g of acrylamide, 60 g of 2-acrylamido-2-methylpropane sulfonic acid and 75 g of methyl acrylate were used, and the initial 2,2′-azobis (2-amidinopropane) dihydrochloride was added in an amount of 0.001. 1 g, 0.4 g of 2,2′-azobis (2-amidinopropane) dihydrochloride continuously added, and methyl acrylate is insoluble in water. Polymerization was carried out in the same manner as in Production Example 1 to obtain a copolymer of 54% by mass of acrylamide, 22% by mass of sodium 2-acrylamido-2-methylpropanesulfonate, and 24% by mass of methyl acrylate.

<Production Example 5>
As a monomer, only 300 g of acrylamide is used, 0.1 g of initial 2,2′-azobis (2-amidinopropane) dihydrochloride is continuously added, 2,2′-azobis (2-amidinopropane) Polymerization was carried out in the same manner as in Production Example 1 except that 0.4 g of dihydrochloride was used to obtain a polymer of 100% by mass of acrylamide.

<Production Example 6>
As a monomer, 180 g of acrylamide and 120 g of acrylic acid were used, 0.1 g of initial 2,2′-azobis (2-amidinopropane) dihydrochloride, and 2,2′-azobis (2- Polymerization was carried out in the same manner as in Production Example 1 except that 0.25 g of (amidinopropane) dihydrochloride was used to obtain a copolymer of 53% by mass of acrylamide and 47% by mass of sodium acrylate.

<Production Example 7>
As monomers, 290 g of acrylamide and 10 g of 2-acrylamido-2-methylpropanesulfonic acid were used, and 0.1 g of initial 2,2′-azobis (2-amidinopropane) dihydrochloride was used. , 2′-azobis (2-amidinopropane) dihydrochloride was used in the same manner as in Production Example 1 except that 0.3 g was used, and acrylamide 96% by mass and sodium 2-acrylamido-2-methylpropanesulfonate 4 A mass% copolymer was obtained.

<Production Example 8>
As monomers, 140 g of acrylamide and 150 g of 2-acrylamido-2-methylpropane sulfonic acid were used, and 0.1 g of the initial 2,2′-azobis (2-amidinopropane) dihydrochloride was used. , 2′-azobis (2-amidinopropane) dihydrochloride was used in the same manner as in Production Example 1 except that 0.45 g was used, and acrylamide was 46% by mass and sodium 2-acrylamido-2-methylpropanesulfonate 54 A mass% copolymer was obtained.

<Production Example 9>
As a monomer, 70 g of 2-acrylamido-2-methylpropanesulfonic acid and 230 g of acrylic acid were used, and 0.15 g of initial 2,2′-azobis (2-amidinopropane) dihydrochloride was added continuously. Polymerization was carried out in the same manner as in Production Example 1, except that 0.45 g of 2,2′-azobis (2-amidinopropane) dihydrochloride was used, and 20% by mass of sodium 2-acrylamido-2-methylpropanesulfonate and acrylic A copolymer of 80% by mass of sodium acid was obtained.

<Production Example 10>
As a monomer, only 300 g of acrylic acid is used, 0.1 g of initial 2,2′-azobis (2-amidinopropane) dihydrochloride is continuously added, 2,2′-azobis (2-amidinopropane) Polymerization was carried out in the same manner as in Production Example 1 except that 0.35 g of dihydrochloride was used to obtain a polymer having a sodium acrylate content of 100% by mass.

<Measurement of viscosity of water-soluble copolymer>
A 10% by mass aqueous solution of the powdery water-soluble copolymer is used as much as possible while stirring 10 parts by mass of the water-soluble copolymer with a magnetic stirrer or the like with respect to 90 parts by mass of ion-exchanged water using a normal beaker. A small amount was added and stirred until the copolymer was completely dissolved. The viscosity of a 10% by mass aqueous solution was measured using a Brookfield viscometer at 25 ° C. The results are listed in Table 1.

<Making tile glaze>
The powdery water-soluble copolymer or CMC produced in Production Examples 1 to 10 and the glaze raw material were pulverized with a ball mill at the following ratio for 3 hours to prepare a glaze.
Frit 100g
420g of silica
Kaolin 480g
Girome clay 60g
200g calcium carbonate
740g of black pigment
1000g of water
Water-soluble copolymer or CMC (No. 1260 manufactured by Daicel Funchem Co., Ltd.)
10g

<Evaluation of glaze glaze>
The glaze adjusted as described above was adjusted by adding water so that the adhering amount was 80 g / J type white roof tile, and evaluated by the following procedure. The results are shown in Table 2.
(1) Drying In a room adjusted to 25 ° C, the above glaze was poured on a white J-shaped roof tile, and the time until the surface dried visually was measured simultaneously with the glaze prepared by CMC (Comparative Example 7). Evaluation based on the criteria.
A: Almost the same as Comparative Example 7 (± 5 minutes).
(Triangle | delta): Compared with the comparative example 7, drying time is long for 5 minutes or more.
X: The drying time is 10 minutes or longer as compared with Comparative Example 7.

(2) Adhesion amount The above glaze (adhesion amount 80 g / J-shaped crosspiece) was stirred overnight in a room adjusted to 40 ° C., and the difference in adhesion amount was compared with the glaze prepared by CMC (Comparative Example 7).
A: Almost the same as Comparative Example 7 (± 10 g).
(Triangle | delta): The adhesion amount is 10-30 g less compared with the comparative example 7.
X: The adhesion amount is 30 g or less smaller than that of Comparative Example 7.

(3) Adhesiveness The above-mentioned glaze was poured on a white J-shaped roof tile, left to stand overnight, drawn with a HB 0.5 mm core, and the dry glaze was observed for the following evaluation.
○: There is almost no peeling around the written line.
Δ: Slightly peeled around the written line.
×: The area around the written line also peels off considerably.

(4) Storage stability of glaze (fluidity)
The glaze was kept stationary in a room adjusted to 25 ° C. for 14 days and checked for the presence or absence of clean water. Specifically, 200 ml of glaze was put in a 200 ml beaker (80 mmφ), and the depth of clean water was measured in mm.
A: No water was observed (0 mm)
A: Water of 5 mm or less was observed.
(Triangle | delta): The water of 5-10 mm was observed.
X: Clean water exceeding 10 mm was observed.

As described in Table 2 above, a monomer mixture containing (meth) acrylamide: 50 to 95% by mass and 2-acrylamido-2-methylpropanesulfonic acid and / or a salt thereof: 5 to 50% by mass The tile glaze of the present invention using a water-soluble polymer obtained by polymerization as a paste, compared with a tile glaze containing a conventional CMC paste or other paste, The glaze has excellent fluidity and storage stability and can be widely used as a glaze for various roof tiles.

Claims (3)

(Meth) acrylamide: 50 to 95 mass% and 2-acrylamido-2-methylpropanesulfonic acid and / or salt thereof: 5 to 50 mass% in a weight ratio based on all monomer units A roof tile glaze obtained by mixing a water-soluble polymer obtained by polymerizing a monomer mixture and a glaze raw material. The tile glaze according to claim 1, wherein the ratio of the water-soluble polymer is 0.1 to 2.0 parts by mass with respect to 100 parts by mass of the glaze raw material. The glaze for roof tiles according to claim 1 or 2, wherein a Brookfield viscosity of a 10% by mass aqueous solution of the water-soluble copolymer is 100 to 50,000 mPa · s.