JP2709521B2 - Method for producing inorganic hydraulic plate material - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for producing an inorganic hydraulic plate material having good production efficiency, which is applied to building materials such as a plate roof tile and a plate outer wall plate. is there.

<Conventional technology and problems to be solved> In general, plate-like inorganic building materials such as roof tiles and exterior wall materials are formed by shaping an inorganic hydraulic material into a raw plate and curing it. Curing in an array requires a huge floor area, so curing is usually done by stacking raw base plates.

By the way, when the uncured raw sheets are cured in a stacked state, the obtained sheet materials adhere to each other and are integrated, and thus the following method has been conventionally employed as a method for preventing such a situation.

(A) A method in which after pre-stacking raw plates, a long pre-heating time is required until curing, making it difficult to adhere and curing.

(B) A method in which a plastic film such as polyester is inserted between raw plates to cure the raw plates stacked.

(C) A method of applying a synthetic resin paint to the surface of a raw plate, and then curing the stacked raw plates.

(D) A method in which a synthetic resin-based paint having releasability is applied to the surface of a raw plate, and then the stacked raw plates are cured.

(E) A method in which raw plates are vertically stacked and cured basically without any load.

However, in the method (a), the production time is long, the production efficiency is very poor, and efflorescence powder is generated on the surface after curing. In addition, there is a problem that an extra eflorescence powder removal process is required.

In addition, the method (b) dissolves the film by heating during curing, which causes stains and the like, the appearance is poor, and it takes time and effort to insert the film.
There was a problem that the cost was high.

Further, in the method (c), when cured in an autoclave, the coating is easily softened because an organic binder is used. However, there is a problem that the function as an undercoat paint is often not sufficiently exhibited.

In the method (d), since a synthetic resin-based paint having releasability is applied, after curing, after applying a topcoat paint,
There was a problem that the interlayer adhesion with the overcoat film deteriorated.

In addition, the method (e) requires a complicated apparatus for vertically arranging the raw plates running horizontally on the conveyor, and has a problem that the raw plates are easily deformed. .

In view of this situation, the present inventors have conducted intensive studies to solve the above-mentioned problems, and as a result, prevent adhesion and integration between plate materials, and prevent precipitation of efflorescent powder, plate materials and overcoating films. The present invention has found a coating material having a function as an undercoating film having good adhesion to the coating, and has developed a method for producing an inorganic hydraulic plate material of the present invention.

<Means for Solving the Problems> That is, the present invention provides an alkali silicate, an acrylic resin or an epoxy resin on a surface of an uncured inorganic hydraulic plate material (hereinafter, referred to as a “raw plate”) formed into a plate shape. With a mixture of the above and a binder, and apply a water-based undercoat paint containing a pigment, then after stacking the resulting coated plate material,
The present invention relates to a method for producing an inorganic hydraulic plate material that is cured and cured.

 Hereinafter, the present invention will be described in detail.

In the present invention, as the inorganic water-curable plate material, various cements, calcium silicate, gypsum, a material obtained by compounding a fine aggregate, a lightweight aggregate, a reinforcing fiber and the like with a material which is hardened by a hydration reaction such as lime. It is formed into a plate shape, and includes those conventionally used for ordinary building materials.

The water-based undercoat paint used in the present invention contains a water-dilutable binder (binder) composed of a mixture of an alkali silicate and an acrylic resin or an epoxy resin, a pigment and water as a diluent as essential components. In which various additives, modifiers, small amounts of organic solvents and the like are blended in accordance with the requirements.

As the alkali silicate, an alkali silicate used in ordinary inorganic paints such as lithium silicate, sodium silicate, potassium silicate, cesium silicate, triethanolamine silicate and ammonium silicate can be used without any particular limitation.

The molar ratio between silicic acid and the alkali substance varies depending on the type of the alkali component.
~ 8.0, for sodium silicate 2.4 ~ 4.0, for potassium silicate 3.0 ~ 4.0, for ammonium silicate 4.0 ~ 2
1.0 (in terms of Na ₂ O) is desirable, but not limited to these.

In particular, in the present invention, sodium silicate, lithium silicate, and potassium silicate are preferable because they have excellent effects of preventing the precipitation of the efflorescence powder after curing of the plate material and the effect of preventing integration between the plate materials.

The acrylic resin is an alkyl ester monomer having 1 to 8 carbon atoms of acrylic acid, a copolymer of an alkyl ester monomer having 1 to 8 carbon atoms of methacrylic acid or a monomer copolymerizable with these monomers, for example, (meth) acrylic acid; Functional monomers such as itaconic acid, 2-hydroxyethyl (meth) acrylate, glycidyl (meth) acrylate, (meth) acrylamide, N-methylol (meth) acrylamide, or styrene, vinyltoluene,
An emulsion resin obtained by appropriately combining monomers such as (meth) acrylonitrile, vinyl chloride, and butadiene and polymerizing in the presence of an emulsifier according to a conventional method is preferred.

The molecular weight of these acrylic emulsion resins is about 50,000-
Advantageously, it is 300,000, preferably 100,000 to 200,000.

The glass transition temperature (hereinafter referred to as Tg) of acrylic resin
Those having a temperature of 20 ° C. or higher, preferably 40 ° C. or higher, are advantageous because they hardly block.

The acrylic resin may be a normal dry type or a baked type, and may be a self-crosslinking type resin in which zinc oxide, a metal complex salt, a hydrazide compound and the like are used in combination.

The epoxy resin is preferably an epoxy emulsion resin in which an epoxy resin such as a bisphenol A type epoxy resin, a phenol novolak type epoxy resin, an orthocresol novolak type epoxy resin, a cycloaliphatic epoxy resin or the like is dispersed in water using an emulsifier. . The epoxy equivalent is preferably about 180 to 400.

As a curing agent for an epoxy resin, a polyamide resin obtained by polycondensation of a diamine or a diamine derivative or the like with a dibasic acid, or an aliphatic polyamine such as ethylenediamine, diethylenetriamine, or triethylenetetramine, or a phenol-formalin resin or a phenol formalin resin or an epoxy resin is used. An aliphatic polyamine or the like is used.

Also, a latent curing agent such as dicyandiamide can be used.

The amount of the curing agent used is 0.8 to the epoxy group of the epoxy resin.
A suitable amount is 1.2 equivalents.

Further, the acrylic resin may be provided with a reactive functional group so as to be crosslinked with the epoxy resin without using or in combination with a curing agent.

Since the binder composed of the above mixture of the undercoat paint used in the present invention uses a mixture of an inorganic binder and an organic binder, a synergistic effect of the both, that is, an effect of preventing the unification by adhesion between the plate shapes by the alkali silicate. In addition, the effect of improving the adhesion to the plate material, the effect of preventing efflorescence powder by the acrylic resin or the epoxy resin, the effect of improving the adhesion to the top coat, and the like are exhibited, and an excellent undercoat film is formed.

The mixing ratio (solid content) of the alkali silicate and the acrylic resin and / or the epoxy resin is desirably (20 to 50:80 to 50) (by weight) in order to exert the above-mentioned effect.

The pigment may be either an inorganic pigment or an organic pigment, but is preferably an inorganic pigment from the viewpoint of heat resistance, hot water resistance, alkali resistance and the like.

Specific examples include color pigments such as titanium oxide, iron oxide, and carbon black, and extenders such as calcium carbonate, talc, and barium sulfate, but are not limited thereto.

Pigment is effective in preventing integration due to adhesion between plate materials, preventing precipitation of efflorescent powder, and improving adhesion to plate materials.
The mixing amount is suitably about 30 to 200 parts by weight with respect to 100 parts by weight of the binder (solid content).

The water as the diluent is suitably blended so that the solid content of the undercoat paint is 25 to 65% by weight, preferably 30 to 55% by weight.

As the additive, various dispersants, thickeners, defoamers,
Examples include a preservative, a fungicide, and a film-forming aid.

Next, a method for producing the inorganic hydraulic plate material of the present invention will be described.

A raw raw sheet or natural curing (for example, 1) formed by molding an inorganic hydraulic substance into a plate shape by an ordinary method such as an extrusion molding method, a press molding method, an integral molding method, a dry molding method, a cast molding method, and a papermaking method. Air-spraying the undercoat paint on the surface of the raw plate which has been primarily cured by means of heat curing (for example, heating at 50 to 100 ° C. for 5 to 15 hours).
It is applied by means such as airless spray, shower coat, and flow coat. In addition, the wet application amount is 25 to 180 g
/ m ² , preferably 50 to 150 g / m ² . Next, the painted raw plates are stacked. It is to be noted that the time for stacking the coated raw plates is to apply the undercoat paint, and to apply the undercoat paint in a wet state (preferably within 2 minutes after the application) or to at least the extent that the paint film is not damaged when being stacked (half the coat). ) When in a cured state (eg 13
(At 0 ° C for about 3 minutes or more).

In addition, when the raw paint sheets are stacked when cured halfway to the extent that the coating film is damaged when stacked, the coating film adheres to the other adjacent raw paint sheet, and as a result, the plate material is easily integrated, which is not preferable. .

Next, the stacked raw plates are autoclaved,
The coated raw plate is cured by a normal curing method such as heat curing, steam curing, or natural curing.

The cured inorganic hydraulic plate material having an undercoating film obtained in this way is applied according to an ordinary method, if necessary, by applying an intermediate coating material, and then applying a topcoating material to produce a product. The paint is not particularly limited, but an aqueous paint such as an acrylic resin emulsion paint is suitable.

<Effects of the Invention> In the method of the present invention, a specific water-based undercoat is applied to the surface of an uncured inorganic hydraulic plate, so that even if the coated plates are stacked and cured, the plates adhere to each other. In addition, the coating of the water-based undercoat paint prevents the efflorescence powder from being precipitated from the surface of the plate material as it is formed on the surface of the plate material, and adheres to the plate material and the overcoat film. Thus, a plate product having good durability, high production efficiency, and excellent durability without peeling of the coating film can be obtained.

Hereinafter, the present invention will be described in more detail with reference to Examples. In the examples, "parts" and "%" are shown on a weight basis.

Example 1 Portland cement 36 parts, quartz sand 58 parts, fly ash 4 parts, polypropylene fiber 1 part, methyl cellulose 1
Part and a composition consisting of 67 parts of water were extruded into a plate shape,
After inserting into the frame pallet, primary curing (steam blowing; 70 ℃,
8 hours). The primary cured plate was taken out of the frame pallet, and the undercoat paint I shown in Table 1 was applied to the surface of the uncured plate by air spray so as to have a coating amount of 75 g / m ² . Then
After drying at 140 ° C. for 3 minutes, the coated plate was loaded, cured in an autoclave (heated to 180 ° C. over 2 hours, and cured at the same temperature for 8 hours), and cured.

Next, the top coat I shown in Table 1 was applied by airless spray so as to have a coating amount of 120 g / m ^{2, and} was dried with hot air at 110 ° C. for 13 minutes to harden the top coat.

Tests were conducted on the occurrence of efflorescence powder after autoclaving, the blocking property of the plate material, the adhesion of the coating film after the top coating, and the freeze-thaw property. The results are shown in Table 2.

Example 2 A plate was produced in the same manner as in Example 1 except that II was used in place of the undercoat paint I, and a top coat was finished.
In addition, the same test as in Example 1 was performed, and the results are shown in Table 2.

Example 3 A plate material was produced in the same manner as in Example 1 except that III was used instead of the undercoat paint I, and a top coat was finished. In addition, the same test as in Example 1 was performed, and the results are shown in Table 2.

Example 4 A plate was produced in the same manner as in Example 1 except that VII was used instead of the undercoat paint I, and a top coat was finished.
In addition, the same test as in Example 1 was performed, and the results are shown in Table 2.

Comparative Example 1 A plate material was produced in the same manner as in Example 1 except that IX was used instead of the undercoat paint I, and a top coat was finished. In addition, the same test as in Example 1 was performed, and the results are shown in Table 2.

Comparative Example 2 A plate material was produced in the same manner as in Example 1 except that X was used in place of the undercoat paint I, and a top coat was finished. In addition, the same test as in Example 1 was performed, and the results are shown in Table 2.

Comparative Example 3 A plate material was produced in the same manner as in Example 1 except that VIII was used instead of the undercoat paint I, and a top coat was finished.
In addition, the same test as in Example 1 was performed, and the results are shown in Table 2.

Comparative Example 4 A plate material was loaded and autoclaved in the same manner as in Example 1 except that the undercoat paint was not applied after the primary curing, and the plate material was cured.

Next, the undercoat paint X was applied by airless spray at a coating amount of 80 g /
m ² , dried with hot air at 90 ° C for 5 minutes, and further coated with 120 g of Topcoat I by airless spray
/ m ² and dried with hot air at 110 ° C. for 10 minutes.

The same test as in Example 1 was performed, and the result was
It is shown in the table.

Example 5 A composition consisting of 20 parts of Portland cement, 45 parts of slag, 22 parts of calcium carbonate, 7 parts of gypsum dihydrate, 4 parts of rock wool, 1 part of polypropylene fiber, 1 part of methylcellulose and 72 parts of water is extruded into a plate shape. Then, after being inserted into the frame pallet, the undercoat paint IV shown in Table 1 was applied by airless spray so as to have a coating amount of 60 g / m ² , and the uncured coated plate material was subjected to primary curing (steam blowing; 70 ° C., 8 hours) )did.

Then take out the painted plate from the frame pallet, load it,
The autoclave was cured (heated to 160 ° C. over 2 hours and cured at the same temperature for 8 hours), further heated at 120 ° C. for 45 minutes, and cured.

Next, the top coat II shown in Table 1 was applied by airless spray so as to have a coating amount of 80 g / m ^{2, and} was dried with hot air at 110 ° C. for 8 minutes to harden the top coat.

The same test as in Example 1 was performed, and the result was
It is shown in the table.

Example 6 Portland cement 17 parts, slag 44 parts, calcium carbonate 21 parts, calcium silicate 8 parts, perlite 5
Parts, 2 parts of glass fiber, 3 parts of pulp, and 122 parts of water were formed into a plate by an integral molding method and subjected to primary curing (steam blowing; 70 ° C., 4 hours). Next, the undercoat paint V was applied to the uncured plate material surface by airless spray so as to have a coating amount of 60 g / m ² , and the coated plate material was immediately loaded and steam cured (steam blowing; 85 ° C., 6 hours). The mixture was heated for 2 hours and cured.

Next, the top coat II was applied by airless spray at a coating amount of 80 g /
m ² and dried with hot air at 110 ° C. for 8 minutes to harden the top coat.

The same test as in Example 1 was performed, and the result was
It is shown in the table.

Comparative Example 5 After the primary curing in Example 6, except that the undercoat was not applied, the board was loaded in the same manner, and the secondary curing (steam curing) was performed.
Then, the plate material was cured.

Next, primer coat XI was applied by airless spray at a coating amount of 60 g /
m applied 90 ° C. ² to become so, 5 minutes air drying, the coating weight 80 g / m ^2, further topcoating II in airless spray thereon
And dried at 110 ° C. for 10 minutes.

The same test as in Example 1 was performed, and the result was
It is shown in the table.

Example 7 Lime 33 parts, calcium silicate 26 parts, diatomaceous earth 22 parts, silica sand 13
Parts, 6 parts of pulp and 133 parts of water are formed into a plate by a papermaking method, and the primary curing (steam blowing; 70 ° C., 6 parts)
Time). Next, the undercoat paint VI was applied to the surface of the uncured plate material by airless spray so as to have a coating amount of 55 g / m ² , immediately loaded with the coated plate material, and cured in an autoclave (heated to 160 ° C. for 2 hours, and heated at the same temperature). Cured for 8 hours) and 12 more
It was heated at 0 ° C. for 40 minutes to be cured. Then coated so that the top coating II in coating weight 80 g / m ² by airless spray,
The coating was dried with hot air at 110 ° C. for 8 minutes to cure the top coat.

The same test as in Example 1 was performed, and the result was
It is shown in the table.

As is clear from Table 2, the coated plate of Example 1 obtained by the method of the present invention was excellent in the efflorescence method, adhesion, and freeze-thaw resistance without integration between the plates. .

On the other hand, a comparative example in which an acrylic resin or an epoxy resin was not blended as the undercoat paint was efflorescence-resistant,
The freeze-thaw resistance was poor.

Further, in Comparative Examples 2 and 3, in which no alkali silicate was blended as the undercoat paint, the plate materials were integrated.

Further, in Comparative Examples 4 and 5, in which the undercoating and the topcoating were applied after the board was cured, not only the board was integrated, but also the adhesion and freeze-thaw resistance of the coating were poor.

Claims (2)

(57) [Claims] An aqueous undercoat paint containing a mixture of an alkali silicate and an acrylic resin or an epoxy resin as a binder and containing a pigment is applied to the surface of an uncured inorganic hydraulic plate material formed into a plate shape. Then, a method for producing an inorganic hydraulic plate material in which the obtained coated plate materials are stacked and cured and cured. 2. The method for producing an inorganic hydraulic plate material according to claim 1, wherein a top coat finish is applied with an aqueous top coat.