JPS5845467B2 - Sugreta Seinoouoyuusuru Soseibutsu - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a composition capable of providing products such as plaster, board, tile, and block having excellent physical and chemical properties. By using a mixture with a specific polymer emulsion that is chemically and mechanically extremely stable, which is difficult to easily achieve through polymerization, as a binder and mixing it with various aggregates, physical and chemical performance can be improved. The present invention relates to providing an extremely superior composition.

Since gypsum products have advantages such as fire resistance, excellent heat insulation and sound permeability, demand for them as building materials has been increasing in recent years, and production has been increasing year by year.

However, it has drawbacks such as low mechanical strength, such as low bending strength and impact strength, and high water absorption and air permeability, so even though it is certified as a noncombustible building material, it is widely used. Limited.

For example, their poor water resistance makes it completely impossible to use them outdoors where they are exposed to wind and rain, or in areas that are easily affected by water.

In order to improve the mechanical strength and water resistance of such gypsum products, a method is known in which an aqueous emulsion of a synthetic resin is mixed into raw gypsum.

However, when an aqueous emulsion of synthetic resin is mixed with raw gypsum, the emulsion is destroyed by Ca + 10 etc. eluted from the gypsum, causing aggregation and coalescence of particles, making it extremely difficult to mix uniformly with gypsum particles. .

In order to prevent these emulsion particles from agglomerating and coalescing, large amounts of emulsifiers and stabilizers are usually used, but this can lead to foaming when mixed with gypsum, leading to a decrease in the strength of the resulting gypsum product. This results in impeding work efficiency.

Therefore, in order to prevent such foaming at the time of crosstalk, a larger amount of antifoaming agent has conventionally been added to emulsions.

However, such emulsifiers and antifoaming agents, which are low-molecular substances, not only inhibit the hardening of gypsum through the hydration reaction, but also deteriorate the properties of the polymer film to be produced from emulsion particles due to water evaporation and volatilization. This is a major hindrance to demonstrating the excellent performance of polymer gypsum products.

The main purpose of using emulsions to improve the performance of such gypsum products is to utilize the film-forming properties of emulsions, but it is known that such film-forming properties are not significantly affected by the composition of the polymer particles. Of course, it also depends on the particle size, and in order to improve the film-forming properties of the emulsion, it is necessary to use a polymer emulsion with a fine particle size.

On the other hand, when coarse particle emulsion and gypsum are kneaded,
Due to non-uniform dispersion of the polymer and insufficient contact between emulsion particles that occurs as the gypsum hardens and water evaporates, anti-film forming properties are significantly inhibited, and the mechanical strength of the resulting hardened gypsum product is impaired. is extremely low.

In order to eliminate this drawback, in Japanese Patent Publication No. 43-30069, an emulsion of a water-insoluble thermoplastic synthetic resin and/or rubber and water are mixed and kneaded with hydraulic cement, and after molding and drying, the resin is Alternatively, heating to the melt flow temperature of rubber is proposed, but in order to fluidize the polymer in the hardened gypsum and make it uniformly mixed with the gypsum, high temperature and long-term treatment is required. Because it itself undergoes oxidative decomposition and becomes colored, it was difficult to obtain the desired effect.

In addition, in Japanese Patent Publication No. 44-14236, a mixed resin liquid of a thermosetting resin and a thermoplastic resin is added to calcined gypsum alone or to a mixture of calcined gypsum, mineral powder, and inorganic fibers, and the mixture is molded, heated, and cured. However, since a mixture of resins with contradictory rheological properties during heating is used, the conditions for obtaining a molded product with the desired performance, especially the mixing ratio of both resins, heating temperature, and heating time, must be adjusted. No matter which method is adopted, there are serious problems inherent in industrial production, such as the addition of large restrictions.

In order to improve the above-mentioned drawbacks, the present inventor has made various studies and found that a water-soluble polymer having a specific composition, which is a portion of the binder, can be used in place of the emulsifier. In addition, by using emulsions consisting of chemically and mechanically stable fine polymer particles that do not contain conventional emulsifiers, compositions with very significantly improved mechanical and chemical properties can be produced. We discovered this fact and arrived at the present invention.

The main object of the present invention is to provide a composition with extremely excellent physical and chemical properties.

The object of the present invention is to use a mixture of gypsum and a specific polymer emulsion as a binder, and mix various solid materials as aggregates with the binder, thereby creating a material that can be used in tiles, flooring, exterior materials, fittings, furniture, and industrial applications. The object of the present invention is to produce a composition that can be used for materials etc. at low cost and with industrial advantage.

Furthermore, other objects of the invention will become apparent from the detailed description of the invention provided below.

The object of the present invention is to obtain a radical polymerizable polymer in the presence of a water-soluble polymer containing a monomer unit consisting essentially of (1) gypsum and (2) an ethylenically unsaturated sulfonic acid or a salt thereof. Along with a polymer emulsion obtained by polymerizing a monomer having an unsaturated bond in an aqueous medium, (3)
This is achieved by mixing various aggregates at a gypsum/aggregate weight ratio of 0.1 to 5.0.

As described above, the present invention is to obtain an excellent composition by mixing an aqueous emulsion of a specific polymer with gypsum and aggregate, and which has far superior mechanical and chemical performance compared to conventional compositions. This makes it possible to industrially manufacture products with great ease and at low cost.

That is, when the polymer emulsion, gypsum, and aggregate are kneaded according to the present invention, the flow start point of the mixed material is significantly accelerated, and there is no foaming during kneading, and the viscosity of the kneaded material is also extremely low. Moreover, it has the characteristic that it does not have any adverse effect on the curing time of plaster.

In other words, the water/gypsum ratio is lower when preparing various desired products from the polymer emulsion of the present invention, gypsum and aggregates than the usual method of blending polymer emulsions obtained by conventional methods. As a result, the mechanical strength of the product can be further increased.

Moreover, the kneaded material (composition) according to the present invention has a lower viscosity and is easier to flow at the same water/gypsum ratio than conventional mixed materials, making it extremely easy to handle and suitable for use in the production of molded products or as plaster. It also has significant advantages.

In addition, since the polymer emulsion particles used in the present invention are so fine that they sufficiently fill the gaps between gypsum particles, they can be evenly interposed with gypsum, and there is no adverse effect on the water use reaction of gypsum, and water The formation of a film from the emulsion particles that occurs with the evaporation and volatilization of the emulsion is also not substantially affected in any way.

Therefore, the formed film sufficiently envelops the gypsum particles and aggregate, and the film is continuous and strong without holes or other cut-off parts.

Furthermore, since the polymer emulsion produced according to the present invention has various characteristics as described above, the mixture obtained by mixing the emulsion with gypsum and aggregate becomes extremely easy to handle, and production efficiency and In addition to improving work efficiency, the molded products obtained through processes such as molding and drying have high mechanical strength, chemical resistance, and water resistance, which are superior to conventional plaster products. This results in a molded product with additional characteristics.

Thus, by incorporating a specific polymer emulsion and using a gypsum mixture as an aggregate binder in accordance with the present invention, various products can be manufactured very easily by conventional methods, and yet have high mechanical strength and durability. This made it possible to manufacture products with characteristics such as excellent chemical resistance and water resistance.

In particular, by using the composition according to the present invention, it is possible to impart excellent mechanical and chemical performance to products obtained from the composition, and the use thereof can be extended to conventional materials such as exterior materials, flooring materials, and building materials. One of the major features of the present invention is that it can be extended to a range that was unimaginable for gypsum products.
Its industrial significance is extremely significant.

Here, the water-soluble polymer used in the production of the polymer emulsion used in the present invention refers to a monomer unit (component A) consisting of an ethylenically unsaturated sulfonic acid or a salt thereof as a constituent unit of the polymer. A water-soluble polymer containing component A can be effectively used in the present invention, but in general, component A can be polymerized by a well-known method. (Particularly suitable is solution polymerization using water as a polymerization medium).

In addition, in order to obtain a fine polymer emulsion that is particularly preferably used in the present invention, it is necessary to use a monomer unit consisting of an ethylenically unsaturated carboxylic acid or a salt thereof together with the component A as the water-soluble polymer constitutional unit. It is desirable to use a water-soluble polymer in which (component B) is bonded, and such a water-soluble polymer may be obtained by any method; Any water-soluble polymer having a certain proportion of the components can be effectively used, but in general, component A and component B are copolymerized by a well-known method (solution polymerization using water as a polymerization medium is particularly preferred).
It can be manufactured by letting it grow.

In addition, as a method of introducing component A or component B, component A may be introduced by sulfonation of the polymer, or a copolymer in which component A is copolymerized with unsaturated carboxylic acid esters such as acrylic esters. Of course, methods such as hydrolysis can also be employed.

In addition, copolymers or derivatives thereof in which component A is copolymerized with one or more monomers consisting of ethylenically unsaturated compounds or salts thereof other than component B, such as those described in JP-A No. 49-64687. Sulfonic acid group-containing polyvinyl alcohol and its derivatives obtained by hydrolyzing a copolymer obtained by copolymerizing component A and vinyl acetate, or in addition to component A and component B, a hydrophobic material such as vinylidene chloride. Water-soluble polymers obtained by copolymerizing or graft-polymerizing small amounts of monomers are also included in the water-soluble polymers of the present invention.

In addition, as the A component introduced into such a water-soluble polymer, sulfonated unsaturated hydrocarbons such as sulfonated styrene, allylsulfonic acid, vinylsulfonic acid, methallylsulfonic acid, and salts thereof; methacrylic acid Examples include sulfoalkyl esters of acrylic acid or methacrylic acid, such as sulfoethyl ester and sulfopropyl methacrylate, and salts thereof.

In addition, the B component preferably introduced into the water-soluble polymer includes unsaturated carboxylic acids such as acrylic acid, methacrylic acid, and crotonic acid, and salts thereof: maleic acid, fumaric acid, itaconic acid, and aconitic acid. , unsaturated polyhydric carboxylic acids such as citraconic acid and mesaconic acid, and their salts, etc., but from the viewpoint of emulsion stability and emulsion particle size, monomers consisting of methacrylic acid and its salts are particularly suitable. Introduction of body units is recommended.

The polymer emulsion used in the present invention is produced in the same manner as conventional emulsion polymerization methods, except that the water-soluble polymer described above is used instead of the emulsifier.

That is, the monomer to be polymerized, water in which 0.5 to 10% by weight of the water-soluble polymer and a predetermined amount of the water-soluble catalyst are dissolved are supplied to the polymerization system. , After adding a chain transfer agent, a polymerization system pH adjuster, etc. as necessary,
Polymerization is carried out at a predetermined temperature by batch polymerization or continuous polymerization.

In addition, in the present invention, particularly when producing an extremely fine and stable polymer emulsion using a water-soluble polymer containing the above-mentioned A component and B component, the polymerization pE (
If a polymerization pH of more than 4 is used, the particle size of the resulting polymer will become large.
The stability of the emulsion also deteriorates.

In addition, when using a water-soluble polymer containing A component and B component as a water-soluble polymer, the composition ratio of A component and B component is determined so that the radically polymerizable unsaturated bonds to be polymerized are It varies depending on the type of monomer it has, and it is difficult to define it uniquely, but generally the A component is 30
~80 weight.

A composition ratio such that component B has a weight of 70 to 20 ★ is preferably adopted.

Further, there is no particular restriction on the degree of polymerization of such water-soluble polymers, but within a practical molecular weight range, it seems that using a polymer with a small molecular weight can yield a polymer emulsion with finer particle diameters.

The monomer having a radically polymerizable unsaturated bond that can be used in such polymerization may be any monomer that can normally be subjected to emulsion polymerization, and may vary depending on the degree of performance of the target composition. Although selected as appropriate, for example, butadiene,
Conjugated diene monomers such as isoprene; Aromatic vinyl monomers such as styrene, α-methylstyrene, and chlorostyrene; Vinyl cyanide monomers such as acrylonitrile and methacrylonitrile; Methyl acrylate, acrylic acid Acrylic esters and methacrylic esters such as ethyl, butyl acrylate, methyl methacrylate, ethyl methacrylate, and butyl methacrylate; Vinyl halides and vinylidenes such as vinyl chloride, vinyl bromide, vinylidene chloride, and vinylidene bromide; Vinyl esters such as vinyl acetate and vinyl propionate are used singly or in mixtures, and particularly good results have been obtained in the polymerization of hydrophobic monomers such as aromatic vinyl monomers, vinyl halides, and vinylidenes. can get.

Furthermore, as the polymerization catalyst used for polymerization, any known radical-generating water-soluble polymerization catalyst such as persulfate can be used, but in particular, persulfate and reducing sulfoxy compounds (and/or It is desirable to use a redox catalyst consisting of a combination of ferrous ion), a combination of chlorate and a reducing sulfoxy compound, etc.

Thus, the polymer emulsion obtained according to the present invention is an emulsion with an extremely fine particle size, and has excellent stability against electrolytes, freezing stability, mechanical stability, etc.

Examples of gypsum that can be mixed into various aggregates together with the polymer emulsion thus obtained include anhydrite, hemihydrate gypsum, and trihydrate gypsum. It is preferable to use anhydrite or hemihydrate, which can be cured by oxidation.

Of course, there is no problem even if these gypsums with different water usage conditions are mixed and used in an appropriate ratio.

In addition, in order to produce a composition with excellent performance according to the present invention, the amount of polymer that should be coexisting in the composition is 0.05 or more, preferably 0.1 to 0.1 in terms of polymer/gypsum weight ratio.
A value of 1.0 is preferably adopted.

Note that when the polymer/gypsum ratio is less than 0.10, no significant improvement in the performance of gypsum-containing products is observed, and when a value exceeding 1°0 is adopted, the weight on the 70-weight board is In addition to the difficulty of producing a polymer emulsion containing coalesced particles, it is economically disadvantageous to mix a large amount of polymer with gypsum, and the inherent fire resistance of gypsum In fact, this results in disadvantageous results, such as making it difficult to exhibit excellent performance such as heat resistance, sound insulation, and low cost.

Furthermore, the aggregate used in the present invention refers to solid materials that are used for the same purpose as pebbles and sand used in general concrete.For example, in addition to the pebbles and sand mentioned above, stone powder, slag,
Inorganic materials such as pumice, pearlite, and other minerals, blast furnace slag, rolling sludge, ceramics, red mud, and shellfish; Organic materials such as wood chips, plastic scraps, and waste tires; Fibrous inorganic materials such as glass wool and asbestos; Nylon filaments , fibrous organic materials such as polyester fibers, and mixtures thereof may be used, but any solid material may be used as long as the purpose of the present invention is achieved.

Therefore, one of the excellent advantages of the present invention is that most of the solid industrial wastes can be used as aggregates in the present invention.
It is one.

Furthermore, the amount of aggregate that should coexist in the composition should be within the range of 0.1 to 5.0 in terms of gypsum/aggregate weight ratio, taking into account the type, shape, physical properties, and purpose of molding of the aggregate used. It is necessary to select it appropriately, and in particular, it is desirable to mix wires so that the proportion of aggregate in the final product obtained from the composition is 30% or more.

In addition, if the amount of aggregate used is too small, the effect of using aggregate, especially the effect of improving physical properties, cannot be expected, and if the amount used is too large, gypsum and polymer emulsion will not be sufficient as a binder. This is undesirable because it does not work well and results in a product with inferior physical properties.

According to the present invention, a method of operation for obtaining a desired composition in which a mixture of a polymer emulsion and gypsum is kneaded as a binder with various aggregates includes, for example, thoroughly mixing gypsum and the polymer emulsion in advance, and then A method in which the aggregate is mixed with the aggregate afterwards, or a method in which the aggregate and the polymer emulsion are sufficiently mixed in advance and then kneaded with the gypsum, and a method in which the gypsum and the aggregate are mixed in advance and then kneaded with the polymer emulsion. Various methods may be adopted, such as a method of mixing the polymer emulsion and gypsum, but they may be mixed and kneaded in any order and method as long as the polymer emulsion and gypsum essentially act as a binder. Because of its excellent properties, it can be advantageously used as a base coat and top coat material for interior or exterior applications, and products such as boards, blocks, and tiles can be produced by pouring the composition into the desired formwork. It can be easily produced by molding and curing, followed by releasing and drying.

The molding and curing operation is preferably carried out at room temperature and under normal pressure, but it may also be carried out under heating and pressure, taking into account the film-forming temperature of the polymer latex used or the properties of the kneaded product.

However, if the molded product is released from the mold and immediately dried at a high temperature after the plaster has hardened, rapid evaporation of water will occur, and the mechanical strength of the resulting molded product will not increase.

Therefore, to obtain a product with high mechanical strength, it is best to dry at a relatively low temperature, with the drying temperature ranging from room temperature to about 60°C, and the drying time depending on the drying temperature, but about A range of 0.1 to 240 hours is preferably adopted.

In addition, if necessary, further about 80 to 150℃, about 1 to 1
Secondary drying is performed under drying conditions of 0 hours.

Further, the molding operation can be carried out batchwise or continuously.

Products obtained from the composition according to the present invention have extremely excellent water resistance and mechanical strength, so they can be used in tiles, flooring materials, exterior materials, building materials, etc., which cannot be used with conventional plaster products. It can also be used for furniture, industrial materials, etc.

Note that water may be added to the polymer emulsion according to the present invention for the purpose of adjusting the water/gypsum ratio and the polymer/gypsum ratio, or
In addition, the composition according to the present invention may contain a gypsum setting retardant, a foaming agent, an antioxidant, a light stabilizer, a thickener, etc., as well as a coloring agent, a decorative agent (for example, marble pieces, mica, metal powder, etc.), etc. Various additives may be added to improve the quality or aesthetics of the final product.

It goes without saying that the polymer emulsion used in the present invention may be a mixture of two or more types of polymer emulsions produced according to the present invention.

The examples described below are intended to better explain the invention and are not intended to limit the scope of the invention.

It should be noted that all percentages and parts shown in the examples are based on weight unless otherwise specified.

Example 1 Three types of water-soluble copolymers of methacrylic acid (MAA) and sodium p-styrene sulfonate (SPSS) were obtained with the following polymerization compositions.

For polymerization, 2 parts of ammonium persulfate, 1.8 parts of acidic sulfite, 0.0015 parts of ferrous chloride, and 230 parts of ion-exchanged water were added to 100 parts of these mixed monomers, and the mixture was stirred at 70°C for 1 hour. carried out.

The water-soluble polymers thus obtained (I, II, I
40 parts of the aqueous solution of I) and 0.014 part of ferrous chloride in 46
After dissolving in 0 parts of ion-exchanged water and charging this solution to a fifth flask equipped with a stirrer, 2 dropping funnels, and a Dimroth condenser, and further charging 320 parts of vinylidene chloride and 40 parts of butyl acrylate, Stirring was started.

Next, a solution of 1.2 parts of ammonium persulfate dissolved in 50 parts of ion-exchanged water and acidic sulfite were added.
．． A solution prepared by dissolving 0 part in 20 parts of ion-exchanged water was placed in a separate dropping funnel and added dropwise to initiate polymerization.

The dropping rate of these catalyst liquids was controlled so that the dropping was completed in one hour.

Note that the pH of the polymerization system was 3 or less when using any of the water-soluble polymers I, II, and H, so no special control was performed.

The polymerization reaction was carried out at 30°C under atmospheric pressure for 2 hours, and the resulting polymer emulsion was observed under a microscope to confirm that no unreacted monomer remained.

The average particle diameter of the emulsion polymer obtained here was extremely fine, 0.05 μm or less in all cases.

To 100 parts each of the three types of emulsions thus obtained, 120 parts of hemihydrate gypsum (polymer/gypsum ratio 0.33, water/gypsum ratio 0 .50) and stir,
Furthermore, 120 parts of slag was added, quickly kneaded, and charged into a metal mold, then left to harden under pressure (50 Kq/criL) at room temperature for 30 minutes, and then the mold was removed.
It was dried at room temperature for 12 hours and then kept at 90° C. for 2 hours in an electric constant temperature dryer.

The three types of cured products obtained did not undergo volumetric shrinkage during curing and maintained the same dimensions as the mold.

In addition, all of them had high surface hardness and were significantly superior to any of the conventional gypsum products in terms of mechanical properties such as abrasion resistance, impact resistance, bending strength, and compressive strength.

Regarding water resistance, the molded product produced according to this example showed no change in shape or mechanical strength even when boiled in hot water for 15 minutes.

On the other hand, 60 parts of water was mixed with 120 parts of gypsum hemihydrate, and the mixture was further kneaded with 120 parts of slag to produce a molded product according to a conventional method.

When the obtained molded product was boiled in water for 15 minutes, it developed many cracks and could not maintain its original shape.

Furthermore, mechanical properties such as surface hardness, compressive strength, tensile strength, and bending strength were also significantly inferior to the products produced by the method of the present invention.

Example 2 100 parts of the emulsion obtained using ■ as the water-soluble copolymer in Example 1 was preliminarily mixed with 120 parts of gypsum hemihydrate,
0.6 parts of hardening retarder, granite powder (maximum particle size 13 mm)
A mixture containing 120 parts was kneaded and a molded product was produced in the same manner as in Example 1.

This molded product had surface hardness, abrasion resistance, water resistance, bending strength, compressive strength, and impact resistance, etc., of gypsum-granite powder produced by the same method as the manufacturing method of the gypsum-slag molded product shown in Example 1. It was also superior to moldings made from commercially available emulsions and gypsum and granite powders described below.

Further, in this molding operation, no foaming was observed during stirring, and no residual air bubbles were observed in the molded product.

Furthermore, in order to examine water resistance, the obtained molded product was treated in boiling water for 15 minutes, and it was confirmed that the molded product had excellent water resistance, with no change in shape or decrease in strength.

On the other hand, for comparison, Aron 110 was used as a commercially available emulsion.
0 (Polyvinylidene chloride latex manufactured by Toagosei Chemical Co., Ltd.)
100 parts and 160 parts of gypsum hemihydrate (polymer/gypsum ratio is 0.2
5), add 2 parts of water (water/gypsum ratio becomes 0.50) and stir, then add 120 parts of granite powder and knead.
When a molded product was produced by curing using the same method as the method according to the present invention described above, extremely significant foaming was observed when the emulsion and plaster were stirred, and many air bubbles remained in the resulting molded product. The mechanical properties such as surface hardness, tensile strength, and bending strength were also significantly inferior to those obtained by the method according to the present invention.

It was also revealed that when the obtained molded product was boiled in water for 15 minutes, the molded product itself became significantly softened and its strength decreased.

Example 3 Three types of emulsions (water-soluble copolymer I used,
Three types of emulsions are obtained according to
A molded article was obtained in the same manner as in Example 1 except that the diameter was changed to 1 mm).

These molded products are the molded products made only of gypsum, aggregate, and water that were prepared for comparison in Examples 1 and 2;
Compared to molded products obtained using commercially available emulsions,
It had far superior mechanical properties and water resistance.

In addition, a gypsum-containing molded article was prepared in the same manner as in Example 1 using DasSeal F (vinyl acetate emulsion manufactured by NOF Corporation) as a commercially available emulsion, but it took about 2 hours to harden at room temperature.
It took 4 hours, and the molded product thus obtained was only immersed in water at room temperature, and the surface gradually leached out, resulting in completely poor water resistance.

Example 4 In Example 1, the emulsion obtained using the water-soluble copolymer (■) was used, and the various aggregates and gypsum hemihydrate shown in the table below were blended in the proportions shown in the table. Various gypsum-containing molded products were obtained by the same operation as in Example 1.

It was confirmed that the thus obtained molded product had superior properties in terms of collapse as compared to molded products that did not use the emulsion according to the present invention.

Claims (1)

[Claims] 1 (1) gypsum and (2) a monomer having an unsaturated bond that can be radically polymerized in the presence of a water-soluble polymer containing a monomer unit consisting essentially of an ethylenically unsaturated sulfonic acid or a salt thereof It has excellent performance and is made by kneading (3 types of aggregate) at a gypsum/aggregate weight ratio of 0.1 to 5.0 with a polymer emulsion obtained by polymerizing it in an aqueous medium. Composition.