JPH11310480A - Lightweight inorganic plate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lightweight inorganic plate having uniformly dispersed foams by equally dispersing a raw material containing a hydraulic substance and a reinforcing fiber into water, adding a water-absorbing substance and synthetic resin foam small pieces to the dispersion and forming a hardened mat from the obtained slurry. SOLUTION: A hydraulic substance such as various kinds of cements, or the like, and a reinforcing fiber such as wood fiber, or the like, are added to water, stirred and uniformly dispersed to give a raw material slurry. A water absorbing substance and synthetic resin foam small pieces are added to the raw material slurry, stirred and blended. Perlite, baked pumicious sand, diatomaceous earth, or the like, are used as the water absorbing substance and the amount of it added is about 5-60 wt.%. Expanded polystyrene beads, expanded polyethylene beads, or the like, are used as the synthetic resin foam small pieces and the amount of them added is about 1-15 wt.%. The raw material mixture comprising the uniformly mixed and dispersed synthetic resin foam small pieces is formed into a desired shape, the formed material (mat) is cured and hardened, optionally trimmed and coated to give the objective lightweight inorganic plate.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lightweight inorganic plate mainly used as a heat insulating material for a building or a base material for an outer wall material.

[0002]

2. Description of the Related Art In order to produce a lightweight inorganic plate used as a heat insulating material for a building or a base material of an outer wall material by a wet method, generally, a hydraulic material such as various cements and a reinforcing material such as a wood fiber are used. Fibers, fine silica powder such as silica sand, and synthetic resin foam small pieces such as expanded polystyrene beads are added to water, stirred to form a slurry, and the mixed slurry is allowed to flow down onto a porous band such as felt and sucked. Paper forming is continuously performed by dehydration, and the obtained paper mat is cured and cured.

[0003]

However, since the specific gravity of the synthetic resin foam such as the expanded polystyrene beads is very low, about 0.1 or less, and especially 0.05 or less in the case of a high expansion ratio, the foam is small in raw material. The slurry rises in the stirring step, and a uniform slurry cannot be prepared. In particular, in order to uniformly disperse the hydraulic substance, the reinforcing fibers, and the silica fine powder, it is necessary to lower the solids concentration. However, when the solids concentration is lowered in this way, the floating of the foam pieces is more remarkable. Become. for that reason,
In the obtained lightweight inorganic plate, especially in a lightweight inorganic plate having a large thickness such as a heat insulating material, the synthetic resin foam pieces in the plate are not uniformly dispersed, and the strength of the lightweight inorganic plate is reduced or the heat insulating performance is reduced. There is a problem that variation occurs.

[0004] In order to prevent floating of the synthetic resin foam pieces in the slurry, there is a method in which the synthetic resin foam pieces are sprayed on a porous belt of a conveyor in advance, and the slurry is supplied thereon to form a paper. Proposed (Japanese Unexamined Patent Publication No. 1-226305)
issue). However, when the foam pieces and the slurry are separately sprayed and supplied on the porous band as described above, there is a problem that a manufacturing apparatus becomes complicated, and in such a method, the foam is uniformly dispersed in the slurry. It was difficult to do.

Accordingly, an object of the present invention is to prepare a raw material mixture in which small pieces of a synthetic resin foam are uniformly dispersed together with a hydraulic substance and reinforcing fibers, and the small pieces of the synthetic resin are melted or formed. An object of the present invention is to provide a lightweight inorganic plate in which bubbles are uniformly dispersed.

[0006]

In order to solve the above-mentioned problems, the present invention is to uniformly disperse a raw material containing a hydraulic material and a reinforcing fiber in water, then add a water-absorbing substance, and The present invention provides a lightweight inorganic plate comprising a cured product of a mat formed from a slurry to which a small piece of synthetic resin foam is added at the point of time.

On one or both sides of the cured product of the mat,
Furthermore, after uniformly dispersing the raw material containing the hydraulic substance and the reinforcing fiber in water, the water-absorbing substance is added, and the diameter of the synthetic resin foam small piece mixed with the mat at any time is reduced. A cured product of a mat formed from a slurry to which a synthetic resin foam piece is added, and / or a mat formed from a slurry in which a raw material containing a hydraulic substance and a reinforcing fiber and not containing a synthetic resin foam piece is dispersed in water. A cured product may be laminated. The water-absorbing substance is preferably at least one selected from the group consisting of perlite, calcined shirasu, deformed fly ash, diatomaceous earth, and pulverized waste of inorganic plate waste.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail.
Raw materials for the lightweight inorganic plate in the present invention include, for example, hydraulic materials such as Portland cement, alumina cement, blast furnace cement, and wood reinforcing fibers such as wood flour, wood wool, wood chips, wood fiber, wood pulp, wood fiber bundle, A mixture of reinforcing fibers such as inorganic reinforcing fibers such as sepiolite, wollastonite, glass fiber and rock wool, and, if desired, fine silica powder such as silica powder, silica powder (silica sand), silica fume, and clay. used. In the above raw materials, the hydraulic substance is usually 28 to 55% by weight, the reinforcing fiber is 3 to 15% by weight, and when silica fine powder is used, the silica fine powder is used in an amount of 28 to 55% by weight. .

The above raw materials are added to water and stirred to form a raw material slurry. The solid content concentration of the raw material slurry is 17
%, Preferably 9% to 17%. By lowering the solid content concentration in this way,
Along with improving the dispersibility of the reinforcing fibers,
Entanglement between the reinforcing fibers and the inorganic powder (hydraulic substance) can be improved.

Next, a water-absorbing substance and small pieces of synthetic resin foam are added to the raw slurry and mixed with stirring. The order of addition may be any order, and if the hydraulic substance and the reinforcing fibers can be uniformly dispersed in the raw material slurry, the synthetic resin foam pieces are added at the stage of preparing the slurry. Is also good.

Examples of the synthetic resin foam pieces include foamed synthetic resin beads such as foamed polystyrene beads, foamed polyethylene beads, and foamed polypropylene beads, and pulverized synthetic resin foams such as foamed polystyrene, foamed polyethylene, foamed polypropylene, and foamed polyurethane. Can be used. The particle size of the synthetic resin foam piece is usually 0.5 to
It is 10 mm, but preferably 3.5-6.0 mm. Further, the expansion ratio of the foam is usually 10 to 100 times,
Preferably it is 60 to 80 times. Note that, as the synthetic resin foam piece, a piece of prefoamed material having a low expansion ratio, for example, a 5 to 20-fold foam may be used, and the prefoamed piece and the foam piece are mixed. It can also be used. The amount of the synthetic resin foam pieces added is preferably 1 to 15% by weight based on the raw material slurry, and more preferably 2 to 15% by weight.
It is preferably about 5% by weight.

As the water-absorbing substance, it is preferable to use pearlite, calcined shirasu, deformed fly ash, diatomaceous earth, pulverized material of inorganic plate waste, and the like, and if desired, two or more kinds can be used in combination. As perlite, perlite obtained by crushing and heating and foaming can be used. And baking Silas refers to those in porous by sintering the Shirasu. Unlike the fly ash of the JIS standard, the irregular fly ash is a porous ash in which quartz grains remain, have an irregular shape such as a distorted shape or a perforated shape, and are porous.

[0013] The crushed waste of inorganic plate refers to a crushed waste of inorganic plate produced mainly with hydraulic material and reinforcing fiber, and the inorganic plate can be obtained by a wet method, a dry method or a semi-dry method. It may be manufactured by any method.
The specific gravity of a normal inorganic plate (waste material) is around 1.2, but the crushed material has a bulk specific gravity of 0.5 or less because the fiber material portion is exposed. The pulverized product is preferably pulverized until the particle size becomes 1.0 mm or less. If a pulverized waste material of the inorganic plate is used as the water-absorbing substance, the waste material can be effectively used. Other water-absorbing substances include, for example, so-called newspaper waste paper which has not yet been pulped, pulp obtained by dry-milling magazines and the like.

The amount of the water-absorbing substance to be added to the raw material slurry may be such that the floating of the synthetic resin foam pieces is prevented and the foam pieces can be uniformly dispersed in the slurry. It varies depending on the water absorption performance of the substance and the specific gravity of the foam piece, but is usually 5 to 60% by weight. By the addition of the water-absorbing substance, the water in the slurry is absorbed by the water-absorbing substance, and the apparent solid content of the slurry is reduced to about 17%.
Up to 35% to prevent the floating of the foam pieces,
The foam pieces can be uniformly dispersed. Also,
By adding the water-absorbing substance, the weight of the obtained inorganic plate can be promoted, and the synthetic resin foam pieces can be held independently of each other. In addition to the strength of the obtained inorganic plate, heat insulation and water absorption can be obtained. Can also be improved. The apparent solid content concentration of the slurry is defined as the moisture and solid content (hydraulic substance + reinforcing fiber + silica fine powder + water absorbent substance + synthetic resin foam piece) in the slurry that has not been absorbed by the water absorbent substance. And the weight percentage of solids relative to the sum of When expressed by the formula, apparent solid concentration (%) = [solid content / {(moisture + solid content) −moisture absorbed by water-absorbing substance}] × 100.

When a raw material mixture in which small pieces of synthetic resin foam are uniformly dispersed is obtained as described above, the raw material mixture is formed into a desired shape. The molding is a papermaking method, a casting method,
It may be carried out by a usual method such as an extrusion method, but preferably, the raw material mixture is poured onto a porous sheet provided with a weir around it, and vacuum suction dehydration is performed from the back side of the porous sheet, and the mixture is continuously or batch-wise. It is formed by a casting method in which a sheet is formed by a batch method.

When the above-mentioned molding is completed, the obtained molded body (mat) is cured and cured. The curing is usually performed in two stages of primary curing and autoclave curing. The primary curing is usually carried out for 20 to 40 hours without heating or at a heating normal pressure of 60 to 90 ° C. In addition, the autoclave curing is usually performed at 130 to 180 ° C.
For 6-15 hours. With this autoclave curing,
The synthetic resin foam piece may or may not be melted. When melted, the portion where the foam small pieces were present becomes bubbles, and the synthetic resin constituting the foam small pieces is dispersed, so that the obtained inorganic plate has excellent fire resistance. Become. On the other hand, when not melted, the synthetic resin foam pieces maintain an independent state from each other and form closed cells, so that the heat insulating property is excellent. After curing and curing, trimming and painting are performed as necessary to obtain a lightweight inorganic plate of the present invention.

In the lightweight inorganic plate of the present invention obtained as described above, air bubbles (small pieces of synthetic resin foam) are uniformly dispersed, and a decrease in strength and a variation in heat insulation performance are prevented.

The lightweight inorganic plate of the present invention described above is a single layer containing a small piece of synthetic resin foam. However, the lightweight inorganic plate of the present invention comprises a small piece of synthetic resin foam (bubbles) having a large particle size. A core layer having a two-layer structure including a layer containing a synthetic resin foam piece (bubbles) having a small particle size, or a layer containing a synthetic resin foam piece (bubbles) having a large particle size;
It may have a three-layer structure in which a layer containing small pieces (bubbles) of synthetic resin foam having a small particle size is a front and back layer. Here, the synthetic resin foam small piece having a large particle size means a particle having a particle size of 2 mm or more, and preferably a particle having a particle size of 4 to 6 mm.
On the other hand, a synthetic resin foam small piece having a small particle size
It means those having a particle size of less than mm, preferably those having a particle size of 0.5 to 1 mm.

An example of a method for producing such a lightweight inorganic plate (cast casting method) will be described. First, a raw material mixture prepared by a method similar to the method for preparing the raw material mixture in the single-layer lightweight inorganic plate, wherein the particle size of the synthetic resin foam pieces included is 2 mm or more (first raw material mixture) ) And a second raw material mixture comprising a hydraulic substance, reinforcing fibers and small pieces of synthetic resin foam having a particle size of less than 2 mm, and optionally further silica fine powder. In order to uniformly disperse the synthetic resin foam pieces having a particle size of less than 2 mm in the second raw material mixture, the second raw material mixture is prepared by the same method as that for preparing the first raw material mixture. Is preferred.

Next, the second raw material mixture is poured onto the first raw material mixture while the first raw material mixture is poured onto a porous sheet provided with a weir around the first raw material mixture. Or the second raw material mixture is poured onto a porous sheet to form a paper while the first raw material mixture is poured onto the second raw material mixture to form a paper, or the second raw material mixture is formed. While pouring into a porous sheet and making paper,
The first raw material mixture is poured onto the second raw material mixture to form a paper, and the second raw material mixture is poured onto the first raw material mixture to form a paper. The obtained two-layer or three-layer papermaking mat may be cured and cured by the method described above. Alternatively, the first raw material mixture is formed by an extrusion method or the like into a first mat, and similarly, the second raw material mixture is formed into a second mat, and one or both surfaces of the first mat are formed. The second mat can be laminated and cured by curing.

In this way, an extremely lightweight back (front) layer containing small pieces of synthetic resin foam (bubbles) having a large particle size, and large irregularities caused by the small pieces of synthetic resin foam having a large particle size appear on the surface. A lightweight inorganic plate having a two-layer structure with a substantially smooth and lightweight front (back) layer, or an extremely lightweight core layer containing small pieces of synthetic resin foam (bubbles) having a large particle size, and a synthetic resin having a large particle size A lightweight inorganic plate having a three-layer structure of a substantially smooth and lightweight front and back layer in which large irregularities due to the foam pieces do not appear on the surface is obtained.

Further, the inorganic plate of the present invention comprises a layer containing synthetic resin foam pieces (cells) and a layer containing synthetic resin foam pieces (cells).
Or a three-layer structure having a layer containing synthetic resin foam pieces (bubbles) as a core layer and a layer containing no synthetic resin foam pieces (bubbles) as front and back layers. May be used.

In order to manufacture such a lightweight inorganic plate,
The first raw material mixture prepared by the same method as the method for preparing the raw material mixture in the single-layer lightweight inorganic plate, a hydraulic substance and reinforcing fibers, optionally further containing fine silica powder, and a synthetic resin foam piece A second raw material mixture containing no raw material is prepared, and a two-layer or three-layer papermaking mat is manufactured by a method similar to the above-described two-layer or three-layer lightweight inorganic plate, or a two-layer or three-layer papermaking mat is prepared. The layers are laminated and cured.

In this way, the light-weight back (front) layer containing the synthetic resin foam pieces (air bubbles) and the smooth front (back) layer in which the irregularities due to the synthetic resin foam pieces do not appear on the surface. 2
A light-weight inorganic plate having a layer structure or a light-weight core layer containing small pieces of synthetic resin foam (bubbles); and a smooth front and back layer in which large irregularities due to the small pieces of synthetic resin foam do not appear on the surface.
A lightweight inorganic plate having a layer structure is obtained. In addition, the lightweight inorganic plate of the present invention has a layer containing synthetic resin foam small pieces (bubbles) having a large particle size as a core layer, a layer not containing synthetic resin foam pieces as a front (back) layer, and It may have a three-layer structure in which a layer containing small synthetic resin foam pieces (bubbles) is a back (front) layer.

[0025]

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to Examples, but the scope of the present invention is not limited to these Examples.

[Example 1] 37 parts by weight of cement, pulp 5
Parts by weight and 37 parts by weight of silica sand were added to 400 parts by weight of water and stirred to obtain a raw material slurry (solid content concentration: 16.5%). At this time, each raw material could be uniformly dispersed in the slurry. next,
19 parts by weight of pearlite and 2 parts by weight of expanded polystyrene beads (particle diameter: 6 mm, expansion ratio: 60 times) were added to the raw material slurry and stirred. At this time, the apparent solid content of the slurry was 25%, and the expanded polystyrene beads could be uniformly dispersed. Here, the slump degree of the obtained raw material mixture was 18.

The raw material mixture was cast to a thickness of 5
After forming the mat into a cm-size mat, the mat was primarily cured at 80 ° C for 20 hours, and then autoclaved at 165 ° C for 8 hours to obtain a lightweight inorganic plate. The bending strength of the obtained lightweight inorganic plate was 28.4 kg / cm ² , and the compressive strength was 21.6 kg / cm ² .

Example 2 19 parts by weight of pearlite and expanded polystyrene beads (particles) were added to a raw material slurry (solid content concentration: 13.6%) prepared in the same manner as in Example 1 except that the amount of water was changed to 500 parts by weight. (Diameter: 6 mm, expansion ratio: 60 times) and 2 parts by weight. At this time, the apparent solid content of the slurry was 20%, and the foamed polystyrene beads could be dispersed substantially uniformly, although slight floating was observed. Here, the slump degree of the obtained raw material mixture was 94.
The raw material mixture was molded and cured in the same manner as in Example 1. The bending strength of the obtained lightweight inorganic plate is 30.5 kg / cm ²
And the compressive strength was 16.7 kg / cm ² .

Example 3 24 parts by weight of Portland cement, 5 parts by weight of pulp and 24 parts by weight of silica sand were added to 467 parts by weight of water and stirred to obtain a raw material slurry (solid content: 1
0.2%). At this time, each raw material could be uniformly dispersed in the slurry. Next, 45 parts by weight of a crushed inorganic plate waste material (specific gravity: 0.55, particle size: 0.2 mm) and 2 parts by weight of expanded polystyrene beads (particle size: 5 mm, expansion ratio: 80 times) were added to the raw material slurry. And stirred. At this time, the apparent solid content of the slurry was 25%, and the expanded polystyrene beads could be uniformly dispersed. Here, the slump degree of the obtained raw material mixture was 51.

The raw material mixture is cast to a thickness of 4
After molding into a mat of cm, the mat was primarily cured at 80 ° C. for 25 hours, and then autoclaved at 180 ° C. for 7 hours to obtain a lightweight inorganic plate. The bending strength of the obtained lightweight inorganic plate was 38.4 kg / cm ² , and the compressive strength was 22.0 kg / cm ² .

Example 4 A raw material slurry (solids concentration: 9.7%) prepared in the same manner as in Example 3 except that the amount of water was changed to 496 parts by weight, a pulverized inorganic plate waste material (specific gravity: 0) .
55, particle size: 0.2 mm) 26 parts by weight, perlite 19 parts by weight and expanded polystyrene beads (particle diameter: 5 mm, expansion ratio: 80)
2 times) and added with stirring. At this time, the apparent solid content of the slurry was 25%, and the expanded polystyrene beads could be uniformly dispersed. Here, the slump degree of the obtained raw material mixture was 24. The raw material mixture was molded and cured in the same manner as in Example 3. The bending strength of the obtained lightweight inorganic plate is 31.4 kg / cm ² and the compressive strength is 2
It was 3.6 kg / cm ² .

COMPARATIVE EXAMPLE 1 37 parts by weight of cement, 5 parts by weight of pulp, and 37 parts of silica sand so as to have the same weight ratio as in Example 1.
Parts by weight, 19 parts by weight of perlite and 2 parts by weight of expanded polystyrene beads (particle diameter: 6 mm, expansion ratio: 60 times) were simultaneously added to 400 parts by weight of water, and stirred to prepare a raw material slurry. At this time, the apparent solid content concentration was about 25%, and the floating of the expanded polystyrene beads was not observed, but the pulp was formed into fiber balls, and the fiber reinforcing effect of the pulp was not obtained. Here, the slump degree of the obtained raw material mixture was 31. The raw material mixture was molded and cured in the same manner as in Example 1. The bending strength of the obtained lightweight inorganic plate was 14.1 kg / cm ² , and the compressive strength was 9.3 kg / cm ² .

Comparative Example 2 A raw material slurry was prepared in the same manner as in Comparative Example 1, except that the amount of water was changed to 667 parts by weight. At this time, the apparent solid content concentration was about 15%, and the expanded polystyrene beads floated. Here, the slump degree of the obtained raw material mixture was 136. The raw material mixture was molded and cured in the same manner as in Example 1. The bending strength of the obtained lightweight inorganic plate was 25.7 kg / cm ² , and the compressive strength was 12.4 kg / cm ² .

As is apparent from the above Examples and Comparative Examples, after mixing and stirring the hydraulic substance, the reinforcing fibers and the silica fine powder, the apparent water slurry was added by adding the water absorbing substance and the synthetic resin foam pieces. , The solid content of the foam becomes high and the foam pieces are uniformly dispersed, and the strength of the obtained lightweight inorganic plate is increased.

[Embodiment 5] In the same manner as in Embodiment 1, the first
Was prepared. Further, 10 parts by weight of pearlite and 1 part by weight of expanded polystyrene beads (particle diameter: 1 mm, expansion ratio: 60 times) were added to the raw material slurry prepared in the same manner as in Example 1, and the mixture was stirred. did. The second
The raw material mixture is poured onto a porous sheet provided with a weir around it, and while the paper is being formed, the first raw material mixture is poured over the second raw material mixture, and further over the first raw material mixture. The second raw material mixture was poured and subjected to papermaking.
Curing and curing were performed in the same manner as described above. As a result, a lightweight inorganic plate having a three-layer structure of a core layer containing uniformly large bubbles and a substantially smooth front and back layer was obtained.

Example 6 A raw material mixture prepared in the same manner as in Example 1 was prepared by pouring the raw material slurry prepared in the same manner as in Example 1 onto a porous sheet provided with a weir around the same. Pour over the raw material slurry, and further pour the raw material slurry over the raw material mixture to form a paper,
Curing and curing were performed in the same manner as in Example 1. As a result, a lightweight inorganic plate having a three-layer structure of a core layer containing large bubbles uniformly and a smooth front and back layer was obtained.

[0037]

According to the present invention, the synthetic resin foam small pieces are uniformly dispersed in the raw material mixture, thereby obtaining a lightweight inorganic plate in which the synthetic resin foam small pieces or bubbles are uniformly dispersed.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI C04B 24:26 16:08)

Claims (3)

[Claims] 1. A mat formed from a slurry in which a raw material containing a hydraulic substance and a reinforcing fiber is uniformly dispersed in water, a water-absorbing substance is added, and a synthetic resin foam piece is added at an arbitrary time. A lightweight inorganic plate comprising a cured product of: 2. After uniformly dispersing a raw material containing a hydraulic material and a reinforcing fiber in water on one or both surfaces of the cured product of the mat according to claim 1, a water-absorbing substance is added, and A cured product of a mat formed from a slurry to which a synthetic resin foam piece smaller in diameter than the synthetic resin foam piece mixed with the mat according to claim 1 at the time, and / or a hydraulic material and reinforcing fibers are contained. A lightweight inorganic plate obtained by laminating a cured product of a mat formed from a slurry in which a raw material containing no synthetic resin foam pieces is dispersed in water. 3. The lightweight inorganic plate according to claim 1, wherein the water-absorbing substance is at least one selected from the group consisting of perlite, calcined shirasu, deformed fly ash, diatomaceous earth, and pulverized inorganic plate waste. .