JP2011148676A - Raw material for foamed lightweight tile, foamed lightweight tile and method for producing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a foamed lightweight tile having excellent dimensional accuracy, a method for producing the same and a raw material for the foamed lightweight tile. <P>SOLUTION: The raw material for foamed lightweight tile contains 100 pts.wt non-foamable raw material containing at least a plastic raw material and an orientational raw material, and 0.01-1 pt.wt. foaming agent. When total of the components except ignition loss is defined by 100 wt.%, the non-foamable raw material contains 80-100 wt.% in total of three components of SiO<SB>2</SB>, Al<SB>2</SB>O<SB>3</SB>and MgO and when total of the three component of SiO<SB>2</SB>, Al<SB>2</SB>O<SB>3</SB>and MgO is defined by 100 wt.%, the composition ratio (SiO<SB>2</SB>, Al<SB>2</SB>O<SB>3</SB>and MgO) by weight is present in a region A or a region B in a ternary composition diagram. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a tile used for a wall surface or the like as a building material, and particularly to a foamed lightweight tile reduced in weight by foaming in a manufacturing process, a raw material thereof, and a manufacturing method thereof. Specifically, the present invention relates to a foamed lightweight tile having good dimensional accuracy, a method for producing the same, and a raw material for the foamed lightweight tile.

  As a method for reducing the weight of a tile, there is a method in which a foaming agent, a lightweight aggregate, or a lost material is added to a tile raw material. Among these, the method of adding a foaming agent has an advantage that the production cost can be suppressed as compared with the method of adding a lightweight aggregate or a lost article. Various types of lightweight foam tiles that are fired by adding a foaming agent and foamed are known.

  For example, paragraph 0017 of JP 2007-246323 consists of 40 to 60 parts by weight of clay, 10 to 15 parts by weight of glass, 25 to 50 parts by weight of feldspar, and 0.01 to 5 parts by weight of SiC as a foaming agent. A lightweight foam tile obtained by molding and firing a tile material is described.

  In JP-A-4-2676, page 1, right column, line 16 to page 2, upper left column, line 1 contains 40 to 10 parts by weight of clay, 60 to 90 parts by weight of feldspar, and 1 weight of silicon carbide as a foaming agent. A foamed exterior material formed by molding and firing a raw material composed of parts or less is described.

  In paragraph 0025 of JP-A-7-247181, limestone is further added to the foamable raw material comprising 10 to 60 parts by weight of clay, 40 to 90 parts by weight of feldspar, and 0.01 to 2 parts by weight of a gas generating component. A foam tile using a raw material blended with alkali metal oxides such as dolomite, glass, talc, or alkaline earth metal oxides is described.

  Conventional foamed lightweight tiles have a problem in that the size of the tiles varies due to variations in the degree of foaming associated with variations in temperature in the kiln during firing, and the dimensional accuracy is reduced.

  Although not related to foamed lightweight tiles, Japanese Patent Application Laid-Open No. 6-40760 discloses that in the production of a low water absorption ceramic plate having a water absorption of 2% or less, in order to reduce drying and firing shrinkage of the molded body, The addition of anisotropic crystals such as mica, β-wollastonite, and talc is described.

  In the same publication, as a substrate composition for producing a ceramic plate, glass and / or frit powder 15 to 60% by weight, plastic clay 15 to 40% by weight, mica 3 to 40% by weight, β wollastonite 0 to 40% by weight %, Talc 0 to 20% by weight, and prepared so that the total of mica, β-wollastonite and talc is 3 to 60% by weight (Claim 3). These mica, β wollastonite, and talc are anisotropic crystalline substances that are more easily oriented in the plane direction than in the thickness direction in press molding, extrusion molding, and the like (paragraph 0005). In the paragraph 0006 of the same publication, during the firing of the molded body of the raw material, the shrinkage in the plane direction is suppressed by the pulling effect of the anisotropic crystal substance, and the ceramic plate is shrunk in the thickness direction by shrinking in the thickness direction. It is described that the dimensional accuracy is improved.

  Note that the above publication relates to a low water absorption ceramic plate having a water absorption rate of 2% or less as described above, and does not have a foaming agent in the raw material of the low absorption ceramic plate. The invention of this publication is intended to improve the dimensional accuracy during the firing shrinkage process, and does not have the problem of preventing the dimensional accuracy from being lowered due to variations in the foaming degree of the foaming agent.

JP 2007-246323 A JP-A-4-2676 JP-A-7-247181 JP-A-6-40760

  As described above, the foamed lightweight tiles as disclosed in Patent Documents 1 to 3 have a problem that the dimensional accuracy is lowered due to the variation in the degree of foaming accompanying the variation in temperature in the kiln during firing.

  An object of this invention is to provide the foaming lightweight tile with favorable dimensional accuracy, its manufacturing method, and the raw material for manufacture of this foaming lightweight tile.

The foamed lightweight tile raw material of the present invention (Claim 1) is a foamed lightweight tile comprising 100 parts by weight of a non-foamable raw material containing at least a plastic raw material and an orientation raw material, and 0.01 to 1 part by weight of a foaming agent. The non-foaming raw material has a total of 80 to 100% by weight of the three components of SiO ₂ , Al ₂ O ₃ and MgO, where the total of components excluding loss on ignition is 100% by weight. When the total of the three components of SiO ₂ , Al ₂ O ₃ and MgO in the non-foaming raw material is 100% by weight, the weight composition ratio (SiO ₂ , Al ₂ O ₃ , MgO) is 3 of these three components. In the original composition diagram, A ₁ (66.5, 8.5, 25.0), A ₂ (72.0, 6.5, 21.5), A ₃ (74.5, 12.0, 13. 5) and _a 4 (66.5,20.0,13.5) square connecting the Within the area A or _{B 1 (67.6,24.9,7.5), B 2} (72.2,22.2,5.6), B 3 (74.2,23.8,2. 0) and B ₄ (68.9, 29.0, 2.1).

  According to a second aspect of the present invention, there is provided a raw material for foamed lightweight tile according to the first aspect, wherein the plastic raw material is a clay mineral.

  A raw material for foamed lightweight tile according to claim 3 is characterized in that, in claim 1 or 2, the orientation raw material is composed of at least one of talc, mica, plate-like alumina, antigolite and resoldite. is there.

  A raw material for foamed lightweight tile according to claim 4 is the raw material for foamed lightweight tile according to any one of claims 1 to 3, wherein the foamable raw material is at least one of silicon carbide, silicon nitride, aluminum nitride, carbonate, dolomite, and cerium oxide. It is characterized by being.

  The foamed lightweight tile manufacturing method of the present invention (invention 5) is characterized in that the foamed lightweight tile raw material according to any one of claims 1 to 4 is molded and fired.

  The method for producing a lightweight foam tile according to claim 6 is characterized in that, in claim 5, the molding method is press molding or extrusion molding.

  The method for producing a lightweight foam tile according to claim 7 is characterized in that, in claim 5 or 6, the firing temperature is 1130 to 1310 ° C.

  The foamed lightweight tile of the present invention (invention 8) is produced by the method for producing a foamed lightweight tile raw material according to any one of claims 5 to 7.

  The foamed lightweight tile according to claim 9 is characterized in that, in claim 8, the specific gravity is 0.7 to 2.0.

  According to the present invention, a foamed lightweight tile with good dimensional accuracy can be obtained.

  That is, when a foamed lightweight tile is produced by molding and firing a foamed lightweight tile raw material, the degree of foaming of the tile varies depending on the firing temperature. Therefore, in the conventional example, when the distribution of the firing temperature is widened due to the temperature distribution in the furnace or the like, the foamed lightweight tile from which the tile size can be varied becomes low in dimensional accuracy.

  In this invention, the orientation raw material is mix | blended with the raw material for foaming lightweight tiles. This orientation raw material consists of flat particles oriented in the biaxial direction or needle-like particles oriented in the uniaxial direction. When a raw material containing such an orientation raw material is formed into a plate-like tile shape, the orientation raw material particles are oriented in the plane direction of the plate-like molded body. This orientation raw material has a characteristic that a coefficient of expansion in the orientation axis direction is small during firing. Therefore, when the molded body containing this orientation raw material is fired, foam expansion in the tile surface direction (perpendicular to the tile thickness direction) is suppressed during firing, and the foam expansion easily occurs in the tile thickness direction. As a result, even when the firing temperature distribution is wide, the deviation of the expansion coefficient in the surface direction (deviation from the expected expansion coefficient) is reduced, and a foamed lightweight tile with high dimensional accuracy can be obtained.

Further, in the present invention, the weight composition ratio of the three components of SiO ₂ , Al ₂ O ₃ and MgO is within the region A or region B away from the eutectic line of cristobalite and mullite in the ternary composition diagram of these three components. Therefore, it is possible to prevent the melt viscosity from rapidly decreasing during firing. This also improves the dimensional accuracy of the resulting foamed lightweight tile.

  In the present invention, a clay mineral is suitable as the plastic raw material.

  As the orientation raw material, at least one of talc, mica, plate-like alumina, antigolite and resoldite is preferable. These orientation raw materials are flat, and are well oriented so that the orientation axis direction (thickness direction and perpendicular direction) of the orientation raw material becomes the plane direction (perpendicular to the thickness direction) of the plate-like molded body.

  As the foaming agent, at least one of silicon carbide, silicon nitride, aluminum nitride, carbonate compound, dolomite and cerium oxide is suitable.

  The firing temperature during firing of the foamed lightweight tile is preferably 1130 to 1310 ° C. The specific gravity of the foamed lightweight tile is preferably 0.7 to 2.0.

It is a ternary composition diagram showing the range of the weight composition ratio of three components of SiO ₂ , Al ₂ O ₃ and MgO in the raw material for foamed lightweight tile of the present invention. Sample No. of Example It illustrates a _SiO 2, _Al 2 _{O 3} and the weight composition ratio of the three components of MgO in 1-28. Sample No. It is a graph which shows the relationship between the baking temperature of 3, 12, 17, and 27 and the baking shrinkage rate of a long side direction. Sample No. It is a graph which shows the relationship between the calcination temperature of 3, 12, 17, and 27 and a volume change rate. Sample No. It is a graph which shows the relationship between the calcination temperature of 3, 12, 17, and 27 and the foaming contribution rate to a long side direction. Sample No. It is a graph which shows the relationship between the calcination temperature of 3, 12, 17, and 27 and the foaming contribution rate to the thickness direction.

  Hereinafter, the present invention will be described in more detail.

  The foamed lightweight tile raw material of the present invention contains 100 parts by weight of a non-foamable raw material containing at least a plastic raw material and an orientation raw material, and 0.01 to 1 part by weight of a foaming agent.

  The non-foaming raw material preferably contains a raw material for tiles such as feldspar, quartz sand, chamotte, porcelain stone, and wax stone in addition to the plastic raw material and the orientation raw material.

  As the plastic raw material, clay minerals are suitable, and specific examples include kaolin, sericite, kibushi clay, and cocoon clay.

  The orientation raw material may be any of flat particles oriented in biaxial directions and acicular particles oriented in uniaxial directions, but talc, mica, plate-like alumina, antigolite, A raw material made of flat particles oriented in the biaxial direction, such as resoldite, is preferred. The orientation raw material composed of such flat particles has a higher effect of suppressing the expansion of foam in the tile surface direction as compared to the orientation raw material composed of needle-like particles oriented only in the uniaxial direction. The average particle size of the orientation raw material is preferably about 1 to 75 μm. This average particle diameter is a value measured by a laser diffraction particle size distribution meter.

  The ratio of feldspar, plastic raw material and orientation raw material in 100 parts by weight of non-foaming raw material (including ignition loss) is 0-40 parts by weight of feldspar, 20-60 parts by weight of plastic raw material, and orientation for region A. It is preferable that it is 40-60 weight part (100 parts by weight in total of 3 persons) of a raw material. In the case of the region B, it is preferably 0 to 35 parts by weight of feldspar, 60 to 90 parts by weight of a plastic raw material, and 5 to 20 parts by weight of an orientation raw material (100 parts by weight in total for the three members).

Next, a preferable ratio of the three components of SiO ₂ , Al ₂ O ₃ and MgO in the non-foaming raw material will be described.

In the non-foaming raw material, when the total of the components excluding ignition loss is 100% by weight, the total of the three components of SiO ₂ , Al ₂ O ₃ and MgO is 80 to 100% by weight, preferably 90% ~ 98 wt%. In these _SiO 2, _Al 2 _{O 3} and the weight composition ratio of the three components of MgO _{(SiO 2, Al} 2 O 3, MgO) is ternary composition diagram of the three components shown in FIG. _1, A 1 (66. 5, 8.5, 25.0), A ₂ (72.0, 6.5, 21.5), A ₃ (74.5, 12.0, 13.5) and A ₄ (66.5). 20.0, 13.5) in a rectangular area A or B ₁ (67.6, 24.9, 7.5), B ₂ (72.2, 22.2, 5.6), B ₃ (74.2, 23.8, 2.0) and B ₄ (68.9, 29.0, 2.1). The A region is preferably A ₅ (67.0, 12.0, 21.0), A ₆ (70.4, 8.9, 20.7), A ₇ (74.1, 11.9, 14). .0), and A ₈ (67.2, 18.4, 14.4).

The A region is, in particular, A ₉ (68.7, 10.4, 20.9), A ₁₀ (72.3, 10.3, 17.4), A ₁₁ (74.2, 11.8, 14). .0) and A ₁₂ (70.8, 15.0, 14.2). The B region is notably B ₅ (67.6, 24.9, 7.5), B ₆ (72.2, 22.2, 5.6), B ₇ (69.5, 24.8, ₅ ). .7) and B ₈ (72.3, 23.9, 3.8).

  In FIG. 1, a eutectic line L is a eutectic line of cristobalite and mullite.

In the ternary composition diagram of SiO ₂ , Al ₂ O ₃ and MgO in FIG. 1, typical compositions of talc, feldspar and clay are plotted, and a triangle connecting these three points is drawn. In this triangular region, there is a eutectic line of cristobalite and mullite. If the weight composition ratio of the three components of SiO ₂ , Al ₂ O ₃ and MgO is close to this eutectic line L, the melt viscosity rapidly decreases when the furnace temperature rises during firing and approaches the eutectic point. The to-be-fired body (tile that is being fired) is greatly deformed, and the dimensional accuracy of the tile is lowered. On the other hand, the foamed lightweight tile raw material of the present invention has a three-component weight composition ratio within the region A or region B and is separated from the eutectic line L to some extent. Thereby, the rapid fall of the melt viscosity at the time of baking is prevented, and the dimensional accuracy of a tile becomes high.

If the raw material composition deviates from the regions A and B in the direction away from the eutectic line L, or deviates from the region A to the Al ₂ O ₃ rich side, the firing temperature becomes excessively high. When the raw material composition deviates from the region B to the feldspar rich side, the increase in the amount of foaming due to the increase in the firing temperature increases rapidly, and the dimensional accuracy deteriorates.

When the total of the components excluding the ignition loss of the non-foaming raw material is 100% by weight, the total of the three components of SiO ₂ , Al ₂ O ₃ and MgO is 80% by weight or more. The influence by components other than the three components is small.

  As the foaming agent, silicon carbide, silicon nitride, aluminum nitride, carbonic acid compound, dolomite, cerium oxide and the like are preferable, and silicon carbide is particularly preferable.

  The foaming agent is blended in an amount of 0.01 to 1 part by weight, preferably 0.05 to 0.7 part by weight, particularly preferably 0.07 to 0.1 part by weight, based on 100 parts by weight of the total amount of the non-foaming raw material including ignition loss. Is done.

  The raw material for foamed lightweight tile of the present invention may contain silica sand, chamotte, porcelain stone, wax, etc. in the range of 20% by weight or less of the whole in addition to the above raw materials.

  The foamed lightweight tile raw material of the present invention is produced by adding water at 50 to 200% of the raw material weight and mixing using a mill or the like so that these raw materials become a suspension at the above ratio. . The average particle size of the foamed lightweight tile raw material is preferably about 5 to 15 μm.

A foamed lightweight tile is manufactured by molding and firing the foamed lightweight tile raw material. As the molding method, any method in which the orientation raw material is oriented in the molded body at the time of molding can be applied, and press molding, extrusion molding, and the like are suitably employed. For example, when the orientation raw material is flat, when the dry mold for foaming lightweight tile is filled in the lower mold, the upper mold is clamped from above, and dry pressing is performed in the vertical direction, the flat mold The orientation raw material is oriented in a substantially horizontal direction in the flat plane direction. Thereby, the molded object for lightweight foam tiles in which the flat surface direction of the orientation raw material is aligned in the plate surface direction of the plate-shaped molded body is obtained. In the case of dry press molding, the molding pressure is preferably about 50 to 500 kgf / cm ² . The bulk density of the molded body is preferably about 1.5 to 2.0 g / cm ^3, particularly about 1.7 to 1.9 g / cm ³ .

  The firing temperature is preferably 1130 to 1310 ° C, particularly 1180 to 1280 ° C. As the firing furnace, RHK, TK, SK, a ceramic furnace or the like can be used. When a ceramic furnace is used, the firing time (the time for maintaining the firing temperature) is preferably about 1 to 10 hours.

  The specific gravity of the foamed lightweight tile thus obtained is preferably about 0.7 to 2, particularly about 1.2 to 1.8.

  Since the raw material for foamed lightweight tile of the present invention has an orientational raw material, when it is molded into a plate shape and fired, a foamed lightweight tile having good dimensional accuracy in the surface direction is obtained as described above. The reason will be described in detail below.

  In general, the amount of gas generated from the foaming agent varies depending on the firing temperature. Therefore, when foamed lightweight tiles are molded and fired to produce foamed lightweight tiles, the foamed lightweight tiles obtained when the firing temperature varies greatly in the kiln due to fluctuations in furnace temperature distribution and furnace control conditions, etc. The dimensions of vary widely.

  When a foamed lightweight tile raw material containing an orientation raw material is molded, the orientation raw material is oriented in the molded body. For example, when a foamed lightweight tile raw material containing a flat orientation raw material is filled in a mold and pressed in the thickness direction of the tile to form a plate-shaped body, the flat orientation raw material particles are aligned. Orientation is such that the axial direction (the direction of the flat surface) is oriented in the plate surface direction (that is, the direction perpendicular to the pressing direction) of the plate-like molded body. Since this orientation raw material has an effect of suppressing expansion in the flat plane direction during firing, when this molded body is fired, the fired material easily expands in the thickness direction of the tile, but in the tile surface direction. Expansion of the foam is suppressed. Thereby, even if the firing temperature deviates from the planned temperature, the variation in dimensions in the tile surface direction is reduced, and a foamed lightweight tile with high dimensional accuracy can be obtained.

  Hereinafter, the present invention will be described in more detail using examples and comparative examples.

<Manufacture of raw materials for foamed lightweight tiles>
The raw materials for foamed lightweight tiles were manufactured by mixing talc, glazed clay and feldspar shown in Table 1 with silicon carbide. As silicon carbide, silicon carbide “GP3000” manufactured by Nippon Ceramic Industry Co., Ltd. was used with an average particle size of 6 μm.

The talc, clay, feldspar, and silicon carbide were added in the same amount as the raw material weight so as to be a suspension at a ratio shown in Table 2 and mixed by a mill. 1-28 were produced. In addition, No. The _SiO 2, the proportion of _Al 2 _{O 3} and MgO when the _SiO 2, _Al 2 _{O 3} and MgO in the 1 to 32 was 100 wt% are shown in Table 3 and 4, the ternary composition diagram of FIG. 2 Plotted. In order to clarify the drawing, “No” is omitted in FIG. For “1”, only “1” is entered.

<Forming raw materials for foamed lightweight tiles>
The above-mentioned raw material No. for foamed lightweight tile 1 to 32 are subjected to dry press molding (pressure: 50 to 500 kg / m ² ), so that the molded body has a bulk density of about 1.7 g / cm ² (long side 100 mm × short side 30 mm × thickness). About 5 mm).

<Baking>
This molded body was fired in a ceramic furnace for 1 hour at each temperature plotted in FIGS. 3 to 6 to produce a foamed lightweight tile. Hereinafter, no. No. 1 for tiles produced from the raw material No. 1 regardless of the firing temperature. This is called 1 tile. No. The same applies to 2 to 32 tiles.

<Measurement of Specific Temperature Dimensional Change Rate A _L (% / ° C.) in Long Side Direction>
No. About 1-32 tiles, measuring the length L ₁ in the long side direction, substitutes and the length L ₁ and the length of the long side of the shaped body L _{0 (100} mm) in the following equation that Thus, the dimensional change rate a _L (%) in the long side direction was calculated.
Dimensional change rate in the long side direction a _L (%) = (L ₁ −L ₀ ) / L ₀ × 100

Since the foaming degree of the foaming raw material varies depending on the firing temperature, the dimensional change rate a _{L in the} long side direction varies depending on the firing temperature. Therefore, no. For each of tiles 1 to 32, create a graph with the horizontal axis as the firing temperature and the vertical axis as the dimensional change rate a _L (%) as illustrated in FIG. The specific temperature dimensional change rate A _L (% / ° C.) in the long side direction was determined from the slope of the dimensional change rate line, and shown in Tables 3 and 4. The specific temperature dimensional change rate A _L (% / ° C.) in the long side direction indicates how much the dimensional change rate a _L (%) in the long side direction changes when the firing temperature changes by 1 ° C.

<Measurement of specific temperature volume change rate B (% / ° C.)>
The thicknesses of the molded body to which SiC is added and the molded body to which SiC is not added are measured, and the volumes V ₁ and V ₂ are calculated in advance. Also, the long sides of the resulting tiles, the size of the short sides and the thickness direction were measured to calculate the volume V _3, V _4. Then, according to the following calculation formula, For the tiles 1 to 32, the volume change rate (%) was calculated by the following formula.

Volume change rate b (%) = (V ₃ / V ₁ −V ₄ / V ₂ ) × 100

  Since the degree of foaming of the foaming raw material varies depending on the firing temperature, the volume change rate b (%) varies depending on the firing temperature. Therefore, no. For the tiles 1 to 32, create a graph with the horizontal axis representing the firing temperature and the vertical axis representing the firing shrinkage b (%), as shown in FIG. The specific temperature volume change rate B (% / ° C.) was determined from the slope of the values shown in Tables 3 and 4. This specific temperature volume change rate B (% / ° C.) indicates how much the volume change rate changes when the firing temperature changes by 1 ° C.

<Measurement of foaming contribution ratio (%) in long side direction and thickness direction>
No. For the tiles 3, 12, 17, and 27, the foaming contribution ratio (%) in the long side direction and the thickness direction was determined by the following procedure. As shown in FIG. In the tiles 17 and 27, the blending ratio of clay and feldspar is almost the same, and the blending amount of talc is different.

First, by measuring the length W ₁ in the short side direction for each tile, and substituting this length W ₁ and the length W ₀ (30 mm) in the short side direction of the molded body into the following calculation formula: The dimensional change rate a _W (%) in the short side direction was calculated.

Dimensional change rate in the short side direction a _W (%) = (W ₁ −W ₀ ) / W ₀ × 100

Similarly, by measuring the thickness d ₁ for each tile and substituting the thickness d ₁ and the thickness d ₀ (100 mm) of the molded body into the following calculation formula, the dimensional change rate a _d (% ) Was calculated.

Dimensional change rate in the thickness direction a _d (%) = (d ₁ −d ₀ ) / d ₀ × 100

Next, the foaming contribution rate C _L (%) in the long side direction and the foaming contribution rate C _d (%) in the thickness direction were calculated by the following calculation formulas. The results are shown in Tables 5 and 6, respectively.

C _L (%) = a _L / (a _L + a _W + a _d ) × 100 (%)
C _d (%) = _ad / (a _L + a _W + a _d ) × 100 (%)

<Discussion>
(1) Consideration of specific temperature dimensional change rate A _L (% / ° C.) in the long side direction As shown in Tables 3 and 4, No. does not contain talc in the raw material for lightweight foam tile. The specific temperature dimensional change rate A _L (% / ° C.) in the long side direction of the 27 tiles is 0.048 (% / ° C.). On the other hand, in each of the tiles existing in the region A and the region B, the dimensional change rate A _L (% / ° C.) in the long side direction is less than 0.048 (% / ° C.).

In addition, the specific temperature dimensional change rate A _L (% / ° C.) in the long side direction is not necessarily a small value in descending order of the talc content. The reason for this is assumed to be as follows.

  As above, no. In the tiles 3, 12, 17, and 27, the blending ratio of clay and feldspar is almost the same, and the blending amount of talc is varied. No. 3 exists in the area A, and the other tiles (No. 12, 17, 27) are out of the range of the area A and the area B. No. Twelve tiles have a composition close to the eutectic line L.

Talc is an orientation raw material and has the effect of suppressing foam expansion in the tile surface direction. Therefore, the effect of suppressing the expansion of foam is large in descending order of the talc content. However, no. Since 12 is close to the eutectic line L, the viscosity rapidly decreases during firing. Because of this, these No. If the tiles 3, 12, 17, and 27 are arranged in ascending order of the specific temperature dimensional change rate A _L (% / ° C.) in the long side direction, the tiles are not necessarily in the order of increasing talc.

No. The tile 3 (in the region A) has the highest talc blending ratio and is separated from the eutectic wire L to some extent. As shown in FIG. 3, the firing shrinkage ratio a _L (%) in the long side direction is substantially constant (about 5 to 6%) regardless of the firing temperature, and the firing temperature varies between 1100 ° C. and 1240 ° C. Even so, the size fluctuation range is as small as about 1% (6% -5% = 1%). Therefore, even if the firing temperature distribution is somewhat wide, the dimensional error of the obtained tile is small.

No. No. 27 does not contain any talc as an orientation raw material in the foamed lightweight tile raw material, and therefore does not have an effect of suppressing expansion in the tile surface direction by the orientation raw material. Therefore, as shown in FIG. 3, when the firing temperature is changed by about 70 ° C. from 1230 ° C. to 1300 ° C., the dimensional change rate a _L (%) in the long side direction is remarkably changed from 7% to 4%. The width is a large value of about 3% (7% -4% = 3%). Thus, no. As for the tile of 27, when the firing temperature distribution is widened, the dimensional variation of the obtained tile becomes large.

  No. Since 12 and 17 contain talc as an orientation raw material, an effect of suppressing foam expansion in the tile surface direction by the orientation raw material is expected. However, no. Since No. 12 has a composition close to the eutectic line L, the melt viscosity is lowered during firing, so that a dimensional error due to a change in firing temperature is large.

  As described above, the dimensional accuracy of the tiles existing in the regions A and B is improved by adding talc.

(2) Consideration of foaming contribution ratio (%) in the long side direction and foaming contribution ratio (%) in the thickness direction As shown in FIGS. The tiles 3, 12, and 17 are No. which do not include talc. Compared with 27 tiles, the foaming contribution rate (%) in the long side direction is low and the foaming contribution rate (%) in the thickness direction is high. From this, it is understood that talc (orientation raw material) has an effect of suppressing foam expansion in the tile plane direction.

(3) Consideration of specific temperature volume change rate B (% / ° C.) As shown in FIG. When tiles 3, 12, 17, and 27 are arranged in ascending order of specific temperature volume change rate B (% / ° C.), No. 3 is obtained. The order is 27, 3, 17, and 12. Therefore, when there is a discrepancy between the planned firing temperature and the actual firing temperature, if the difference between the target tile volume and the actual tile volume is arranged in ascending order, No. 27, 3, 17, 12 in this order. As described in the above (1), when the specific temperature dimensional change rate A _L (% / ° C.) in the long side direction is arranged in ascending order, No. Has become the order of 3,27,17,12, it does not completely conform to the order of the specific temperature volume change magnitude order as the ratio temperature dimensional change rate A _L magnitude of B. This is no. This is probably because the expansion of the tile 3 in the tile long side direction was suppressed by talc.

No. In the tiles of No other than 3, 12, 17, and 27, the order of decreasing specific temperature dimensional change rate A _L (% / ° C.) in the long side direction and the order of decreasing specific temperature volume change rate B (% / ° C.) Are not necessarily consistent. These orders are closely related to the effect of suppressing expansion of foaming in the tile surface direction by talc (orientation raw material) and the proximity of the three-component composition ratio (SiO ₂ , Al ₂ O ₃ , MgO) to the eutectic line L. It seems to be related to.

(6) Comparison between Region A and Region B Based on Table 2 and Tables 3 and 4, the blending ratio (% by weight) of the orientation raw material (Todai Mizo Talc) in the regions A and B and the specific temperature volume change rate B (% / ° C.) and the specific temperature dimensional change rate A _L (% / ° C.) in the long side direction, the region A has a larger value of the specific temperature volume change rate B than the region B. (Region A: 0.0120 or less, region B: 0.0080 or less), achieving a specific temperature dimensional change rate A _{L in} the long side direction equivalent to region B (both regions A and B are 0.048 or less) Yes. This is because the blending ratio of the blended raw material (talc) is higher in the region A than in the region B (region A: 40 to 60% by weight, region B: 5 to 20% by weight), depending on the orientation raw material (talc). This is considered to be because the expansion of foaming in the tile long side direction was further suppressed.

Claims (9)

100 parts by weight of a non-foaming raw material containing at least a plastic raw material and an orientation raw material;
A foamed lightweight tile raw material comprising 0.01 to 1 part by weight of a foaming agent,
The non-foaming raw material has a total of 3 components of SiO ₂ , Al ₂ O ₃ and MgO of 80 to 100% by weight, assuming that the total of components excluding ignition loss is 100% by weight,
When the total of the three components of SiO ₂ , Al ₂ O ₃ and MgO in the non-foaming raw material is 100% by weight, the weight composition ratio (SiO ₂ , Al ₂ O ₃ , MgO) is a ternary of these three components In the composition diagram,
A ₁ (66.5, 8.5, 25.0)
A ₂ (72.0, 6.5, 21.5)
A ₃ (74.5, 12.0, 13.5)
A ₄ (66.5, 20.0, 13.5)
In the rectangular area A connecting B1 or B ₁ (67.6, 24.9, 7.5)
B ₂ (72.2, 22.2, 5.6)
B ₃ (74.2, 23.8, 2.0)
B ₄ (68.9, 29.0, 2.1)
A material for foamed lightweight tiles, wherein the raw material is in a rectangular region B connecting the two.   2. The foamed lightweight tile material according to claim 1, wherein the plastic material is a clay mineral.   3. The foamed lightweight tile material according to claim 1, wherein the orientation material comprises at least one of talc, mica, plate-like alumina, antigolite, and soldite.   4. The foam lightweight tile raw material according to claim 1, wherein the foamable raw material is at least one of silicon carbide, silicon nitride, aluminum nitride, carbonate, dolomite, and cerium oxide. .   A method for producing a lightweight foam tile, comprising forming and firing the raw material for a lightweight foam tile according to any one of claims 1 to 4.   6. The method for producing a lightweight foam tile according to claim 5, wherein the molding method is press molding or extrusion molding.   The method for producing a lightweight foam tile according to claim 5 or 6, wherein the firing temperature is 1130 to 1310 ° C.   The foamed lightweight tile manufactured by the manufacturing method of the raw material for foamed lightweight tile of any one of Claim 5 thru | or 7.   The lightweight foam tile according to claim 8, wherein the specific gravity is 0.7 to 2.0.

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