JP2767375B2 - Mortar composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention is suitable for producing a mortar composition containing a resin aqueous emulsion, particularly a mortar sheet or a mortar casting used for producing a false wood, a pseudo stone, a waterproofing material for a roof and the like. A mortar composition.

[0002]

2. Description of the Related Art Conventionally, a mortar composition containing a hydraulic inorganic cement such as Portland cement is formed into a sheet having irregularities on a surface or poured into a mold, and then heated and cured and dried to form a mortar sheet. And manufacture of mortar moldings.

However, conventional mortars mainly composed of cement cannot be heated to a high temperature under the open atmosphere in the curing and drying step by heating in the process of manufacturing mortar sheets and mortar molded articles therefrom. If the mortar is heated under high temperature, the water in the mortar volatilizes and the water required for hydraulic setting becomes insufficient, and the resulting molded product cannot be cured.) However, if the composition is rapidly cured by heating at a relatively high temperature, the strength of the cured molded article is reduced.)

Conventionally, a resin mortar containing a resin emulsion has also been known. However, a conventional resin mortar has a thickness of a molded product to be molded, for example, a molded product such as a mortar sheet or a mortar cast product. If it becomes thicker, only the surface layer will be cured and dried at an early stage to form a film, which will hinder the evaporation of moisture inside and not only take a long time to dry, but also cause deformation of the molded product (poor appearance of the molded product). Despite its drawbacks, it can still be used in spite of its drawbacks, as it gives a molded article with a characteristic performance compared to ordinary mortars.

[0005]

An object of the present invention is to provide a mortar composition in which the above-mentioned disadvantages of the conventional resin mortar have been improved, that is, a hardening and drying process during molding can be performed in a short time, and a reduction in strength is achieved. An object of the present invention is to provide a mortar composition capable of obtaining a molded article having an excellent appearance without causing the mortar composition.

[0006]

The mortar composition of the present invention is obtained by polymerizing 100 parts by weight of hydraulic mineral cement with a nonionic surfactant to obtain a resin aqueous emulsion having a resin solid content of 25%. A composition comprising 0.8 to 15 parts by weight, and 0.8 to 15 parts by weight of a silicone-based surfactant based on 100 parts by weight of the resin solid content of the aqueous resin emulsion.

The hydraulic mineral cement constituting the composition of the present invention is referred to as Portland cement (for example, ordinary cement, white cement, high-strength cement, ultra-high-strength cement, etc.) and mixed cement. (Eg, blast furnace cement, silica cement, fly ash cement, etc.), alumina cement, hydraulic gypsum powder, and the like. Generally, Portland cement, particularly ordinary cement, and white cement are preferred.

[0008] The aqueous resin emulsion constituting the composition of the present invention is obtained by polymerizing an unsaturated monomer in an aqueous medium using a nonionic surfactant, preferably by emulsion polymerization.

There are various unsaturated monomers used in the production of the resin aqueous emulsion. For example, 2-ethylhexyl acrylate (Tg-85 ° C)
[Note: The description in parentheses is an abbreviation that the glass transition point of a homopolymer of 2-ethylhexyl acrylate is -85 ° C. The same applies hereinafter), n-butyl acrylate (Tg
-54 ° C), ethyl acrylate (Tg-22 ° C), vinylidene chloride (Tg-18 ° C), isopropyl acrylate (Tg-5 ° C), 2-ethylhexyl methacrylate (Tg-5 ° C), n-propyl acrylate (Tg 8
° C), n-butyl methacrylate (Tg 20 ° C), vinyl acetate (Tg 30 ° C), acrylic acid (Tg 87
° C), n-propyl methacrylate (Tg 81 ° C), styrene (Tg 100 ° C), acrylonitrile (Tg 1
00 ° C), methyl methacrylate (Tg 105 ° C), methacrylic acid (Tg 130 ° C), maleic anhydride, itaconic acid (Tg 130 ° C), acrylamide (Tg 1
53 ° C.), ethyl methacrylate (Tg 65 ° C.), vinyl chloride (Tg 79 ° C.), ethylene and butadiene.

Using these unsaturated monomers, the resulting resin preferably has a glass transition temperature (Tg) of 30 to -50 ° C,
More preferably, they are appropriately combined and polymerized (copolymerized) so that the temperature is 5 to -40C. If the Tg of the resin is too high, the film-forming properties deteriorate, and the molded body becomes brittle.
If the g is too low, the molded article becomes soft, and the stain resistance and the blocking resistance are inferior.

The approximate value of the Tg of the copolymer can be easily estimated from the Tg of the homopolymer of the monomer and the copolymerization ratio of the monomer. By appropriately adjusting the monomers to be used and their copolymerization ratio by polymer design, the desired T
An aqueous emulsion of a resin having a g value can be easily produced.

The nonionic surfactant used in the polymerization of the unsaturated monomer is 10 ° C. below the cloud point of the silicone surfactant incorporated in the mortar composition of the present invention.
As described above, those having a cloud point higher by 15 ° C. or more (for example, those having a cloud point of 80 to 170 ° C.) are desirable (the reason will be described later). Nonionic surfactants suitable for use in the polymerization of the resin aqueous emulsion of the present invention include, for example, polyoxyethylene glycol,
Propylene oxide / ethylene oxide copolymer, ethylene oxide adduct of aliphatic alcohol (for example, polyoxyethylene higher alcohol ether such as polyoxyethylene lauryl ether, polyoxyethylene methyl ether, polyoxyethylene stearyl ether, polyoxyethylene oleyl ether) And polyoxyethylene nonyl phenyl ether.

The amount of the nonionic surfactant is 0.1 to 7 parts by weight based on 100 parts by weight of the monomer to be polymerized. If the amount of the nonionic surfactant is too small, the stability of the emulsion polymerization system is not sufficient, a stable resin emulsion cannot be obtained, and the molded product of the mortar composition obtained by using the resin emulsion is heated. When cured and dried, a sufficient heat-sensitive effect cannot be exerted (the heat-sensitive effect will be described later). Also, if the amount of the nonionic surfactant is too large, the water resistance of the molded product of the mortar composition deteriorates, and the mortar composition is used in order to exhibit a sufficient heat-sensitive effect at the time of curing and drying by heating the molded product. There is a disadvantage that the amount of the silicone surfactant to be blended is increased.

The nonionic surfactant may be used in combination with an anionic surfactant in some cases. The combined amount of the anionic surfactant is usually 0.2 to 5 parts by weight based on 100 parts by weight of the monomer to be polymerized.

[0015] An aqueous resin emulsion obtained by emulsion polymerization using, for example, only an anionic surfactant without using any nonionic surfactant is used. Other components are the same as those of the mortar composition of the present invention. When a mortar composition of the present invention is prepared, regardless of whether the silicone-based surfactant is blended in the mortar composition, a heat-sensitive material such as the mortar composition of the present invention is used when heating the molded article during curing and drying. The effect cannot be exhibited, and therefore, an excellent effect as in the present invention cannot be obtained.

The amount of the aqueous resin emulsion used in the present invention is 25 to 85 parts by weight as a resin solid content based on 100 parts by weight of hydraulic inorganic cement. If the amount of the resin aqueous emulsion is too small, the drying speed is increased, but the water required for hydraulic hardening is insufficient and the hardening of the cement becomes insufficient, the water resistance is poor, and the brittleness is liable to cause chipping. In addition, the molded article is generally hard, has a rough surface, and has a poor appearance. On the other hand, if the amount of the aqueous resin emulsion is too large, the drying speed becomes slow, and particularly in the case of a resin having a low glass transition point, the water resistance tends to deteriorate.

The silicone surfactant in the present invention not only acts to disperse the hydraulic inorganic cement incorporated in the mortar composition of the present invention, but also various additives that may be incorporated as optional components, and acts to disperse the silicone surfactant. The present invention exerts a heat-sensitive effect at the time of heating when curing and drying the molded article of the mortar composition of the present invention, that is, an effect of destroying the resin emulsion in the molded article by heating.

The heat-sensitive effect of the mortar composition of the present invention will be described in detail. In the curing and drying step of heating the molded product of the mortar composition of the present invention, the heating temperature of the molded product is set to the cloud point of the silicone surfactant. , The surfactant activity of the silicone surfactant is lost and the dispersion of the mortar composition is destroyed. At that time, it is presumed that the silicone surfactant is taken into the nonionic surfactant side in the aqueous resin emulsion contained in the molded article, and that the hydrophobic silicone group covers the surface, As a result, the resin emulsion in the molded body is destroyed. Also, as a result, the resin in the molded body can no longer freely move as a resin emulsion,
it is conceivable that.

As described above, the mortar composition of the present invention comprises:
When the nonionic surfactant contained in the resin aqueous emulsion and the silicone surfactant incorporated in the mortar composition are combined, when the mortar composition is heated, the silicone surfactant When the cloud point of the agent is reached, the aqueous resin emulsion will be destroyed. In the present specification, when the mortar composition of the present invention is heated, this phenomenon in which the aqueous resin emulsion is destroyed when the cloud point of the silicone-based surfactant is reached is abbreviated as “thermal effect” for convenience. It shall be.

The mortar composition of the present invention has an aqueous resin emulsion (hereinafter, the aqueous resin emulsion may be abbreviated as “resin emulsion” in some cases).
Using a nonionic surfactant as a surfactant for
In addition, since the combination of the mortar composition and the silicone-based surfactant can exhibit an excellent heat-sensitive effect, the resin emulsion contained in the molded article can be easily formed during the curing and drying process of the molded article of the mortar composition. It will be destroyed. Therefore, the mortar composition of the present invention, like a conventional resin mortar, the resin emulsion floats up on the surface of the molded article during drying during heat curing and drying of the molded article to form a dry film, Since the evaporation of water is not hindered, not only can the curing and drying be carried out smoothly in a short time, but also the effect of obtaining a uniformly cured and dried molded article having excellent appearance and strength can be obtained. .

The silicone-based surfactant used in the present invention reaches a cloud point at a relatively low heating temperature during curing and drying by heating a molded product of the mortar composition, ie, 4
Those having a cloud point of 5-85 ° C are preferred. On the other hand, as described above, the nonionic surfactant used in the polymerization of the resin emulsion needs to be capable of effectively exhibiting an emulsifying action at the polymerization temperature, and the cloud point of the silicone surfactant is required. Those having a cloud point higher than 10 ° C., preferably higher than 15 ° C.
Those having a cloud point of 170 ° C.) are desirable.

The silicone-based surfactant in the present invention is a surfactant having a silicone chain and a hydrophilic group in a molecule. As the hydrophilic group, a polyoxyalkylene glycol unit (for example, a polyoxyethylene glycol unit, a polyoxypropylene glycol unit, etc.)
And nonionic hydrophilic groups such as

Since this type of silicone surfactant is widely marketed under various trade names, the present invention can be carried out using such commercially available products. For example, commercially available silicone surfactants that can be used in the present invention include:
For example, Toshiba Silicone product name SH-3771 (cloud point 73 ° C, hydrophilic group polyglycol), SH-37
46 (cloud point 73 ° C, hydrophilic group polyglycol), S
H-3748 (cloud point 40 ° C, hydrophilic group polyglycol), SH-3748 (cloud point 38 ° C, hydrophilic group polyglycol), and Nippon Unicar product name NUC Silicone FZ2107 (cloud point 53.5 ° C, Hydrophilic group polyoxyalkylene glycol).

The amount of the silicone surfactant used in the present invention is 0.8 to 15 parts by weight based on 100 parts by weight of the resin solid content of the aqueous resin emulsion. If the amount of the silicone-based surfactant is too small, the heat-sensitive effect cannot be sufficiently exerted, and not only a long time is required for curing and drying the molded article, but also the physical properties of the molded article are deteriorated. If the amount is too large, not only is it disadvantageous in terms of cost, but also
Due to the silicone surfactant, the water resistance of the molded product is deteriorated, the molded product is repelled, bubbles are mixed in the molded product due to the generation of bubbles, and the appearance of the molded product is deteriorated, and the strength is reduced. Or cause a decline.

The mortar composition of the present invention may contain various additives as optional components in addition to the above-mentioned essential components. For example, inorganic extender pigments such as calcium carbonate, silica sand, silica stone powder, talc, clay, and aluminum hydroxide; lightweight aggregates such as shirasu and foamed glass; coloring pigments such as titanium oxide, zinc oxide, and iron oxide; dyes; Fiber powder, defoamer, plasticizer, thickener, fungicide, water reducer,
A flow agent, a curing regulator, a wetting agent, and an antifreezing agent can be blended. Further, when producing a molded article of the mortar composition of the present invention, a glass net or a resin net can be used as a reinforcing material.

The amount of the inorganic extender, the lightweight aggregate, and the color pigment varies depending on the specific gravity. For example, in the case of calcium carbonate (specific gravity of 2.7), cement 100 is used.
600 parts by weight or less, preferably 70 to 100 parts by weight,
500 parts by weight.

Next, a method of manufacturing a mortar molded article using the mortar composition of the present invention will be described in detail by taking a case of manufacturing a mortar sheet as an example. Bar, coater, roll, curtain coater, spray, iron, etc. on the surface of the plate, film, sheet, etc. having
Or cast it into a casting mold with mold release properties to make a cast product,
The resulting sheet or cast is heated to a temperature above the cloud point of the silicone surfactant to cure and dry. Examples of the material of the plate or the like having releasability include those treated with fluorine or silicone resin, those coated with release oil, hydrophobic materials such as synthetic resins, and glass. The heating is usually performed under open air, and the heating temperature is usually 80 to 170 ° C.
Is within the range. If the heating temperature is too low, a sufficient heat-sensitive effect cannot be exerted, and a dried film of the resin emulsion is formed on the sheet surface to prevent the evaporation of water inside, so that a long time is required for drying. On the other hand, if the heating temperature is too high, moisture is rapidly evaporated and lost, and the moisture required for hydraulic setting is insufficient, and the strength of the dried sheet is reduced. It is preferable that the sheet after the heat curing and drying is removed from the mold, left to cure at room temperature, preferably under high humidity for 12 to 48 hours, and the sheet is saturated with moisture.

The mortar composition of the present invention contains an aqueous resin emulsion obtained by polymerization using a nonionic surfactant and a silicone surfactant. High-strength molded products can be easily obtained by short-time curing and drying using heating.

Since the resin emulsion is blended, moisture is not rapidly lost even when heating is performed at a relatively high temperature during curing and drying by heating the molded article, so that the molded article becomes brittle or the strength is reduced. Nothing.

Since the mortar composition contains a silicone-based surfactant and the resin emulsion contains a nonionic surfactant, both surfactants work together to heat the molded article during curing and drying. It exhibits an excellent heat-sensitive effect and can easily break the resin emulsion in the molded product, so it can effectively prevent the formation of a resin film that prevents the evaporation of moisture on the surface of the molded product during curing and drying.
As a result, the drying time of the molded article can be shortened, and the appearance of the molded article can be improved.

[0031]

EXAMPLES The present invention will be described in more detail with reference to resin emulsion production examples, examples and comparative examples. The parts and percentages given in these examples are on a weight basis.

Production Example of Resin Emulsion Temperature controller, anchor type stirrer, reflux condenser, supply device,
After replacing the inside of a reaction vessel equipped with a thermometer and a nitrogen gas inlet tube with nitrogen gas, an emulsifier solution having the following composition was charged.

Water 160 parts 35% aqueous solution of sulfuric acid half-ester sodium salt of ethylene oxide 20 mol added p-nonylphenol (referred to as “anionic emulsifier A”) 5 parts ethylene oxide 25 mol added p-nonylphenol (“nonionic emulsifier B 40 parts of a 20% aqueous solution (Note: The cloud point of the nonionic emulsifier B is 100 ° C. or higher.)

Separately, the following mixture was prepared as Feed I: Water 200 parts 35% aqueous solution of the above-mentioned anionic emulsifier A 25 parts Styrene 103 parts Acrylic acid 10 parts N-butyl acrylate 402 parts

Further, as an aqueous initiator solution, water 85
An aqueous solution in which 2.5 parts of potassium persulfate was dissolved was prepared.

In a reactor charged with the above emulsifier solution,
After adding 10% of Feed I above and heating to 90 ° C., 10% of the initiator aqueous solution was injected. Then
In the reactor, the remainder of the feed I and the remainder of the aqueous initiator solution were allowed to react while gradually and uniformly supplied over 3 to 3.5 hours. After the completion of the supply, the reaction was continued at 90 ° C. for 1.5 hours. The emulsion polymerization was carried out while maintaining the temperature.

After completion of the emulsion polymerization, aqueous ammonia (concentration: 28
%) To adjust the pH to 8, thereby obtaining an aqueous resin emulsion. This resin emulsion has a resin solid content of 50
%, Tg of the resin was −30 ° C. This aqueous resin emulsion is referred to as “resin emulsion”.

Production Example of Resin Emulsion A feed having the following composition was used in place of Feed I used in the above Production Example, and a resin aqueous emulsion was produced in accordance with the other Production Examples.

Water 200 parts 35% aqueous solution of the above-mentioned anionic emulsifier A 25 parts Methyl methacrylate 245 parts Acrylic acid 10 parts N-butyl acrylate 260 parts

The obtained resin aqueous emulsion had a resin solid content of 50% and a Tg of the resin of 4 ° C. This resin emulsion is called “resin emulsion”.

Production Example of Resin Emulsion A resin aqueous emulsion was produced in the same manner as in Production Example, except that Feed I having the following composition was used in place of Feed I used in the above Production Example.

Water 200 parts 35% aqueous solution of the above-mentioned anionic emulsifier A 25 parts Methyl methacrylate 400 parts Butyl acrylate 105 parts Acrylic acid 10 parts

The obtained aqueous resin emulsion had a resin solid content of 50% and a Tg of the resin of 55 ° C. This resin emulsion is called “resin emulsion”.

Examples 1 to 7 Comparative Examples 1 to 6 Resin emulsions, resin emulsions, resin emulsions, and aqueous vinyl acetate-ethylene resin aqueous emulsions manufactured by the above-mentioned manufacturing method (Sumitomo Chemical Industries, Ltd., trade name: Sumikaflex S- 500, a resin solid content of 55%, a resin Tg of 0 ° C., a nonionic and an anionic emulsifier used in combination, and a commercially available ethylene-vinyl chloride resin aqueous emulsion (Sumitomo Chemical Industries, Ltd., trade name Sumilite SE) -1010, the resin solid content is 50%, the Tg of the resin is 0 ° C., and the emulsifier used is an anionic emulsifier) as shown in Tables 1 and 2, respectively.
And ordinary cement,
Commercially available silicone-based nonionic surfactant having a polyoxyalkylene glycol group as a hydrophilic group (NUC Silicone FZ2107, trade name of Nippon Unicar Co., Ltd., cloud point 53.5 ° C), calcium carbonate (trade name KD-1 by Dowa Mining Co., Ltd.) ), Foamed Shirasu (Dichi Kasei Co., Ltd. product name: Rinilite SB9011), iron oxide, and antifoaming agent (San Nopco Co., Ltd. product name: Nopco 8032) are appropriately combined and compounded as shown in Tables 1 and 2, and an appropriate amount is mixed. Various mortar compositions were prepared by kneading with water.

Each of the obtained mortar compositions was tested for the appearance and curing / drying properties of the molded article and the heat-sensitive effect of heating the molded article by using the following test methods. The results were as shown in Tables 1 and 2, respectively.

Test Method (1) Appearance and Curing Drying Test of Molded Product The mortar composition was poured into a 100 × 100 × 50 mm polypropylene box mold, and immediately the air at 120 ° C. was passed. It was placed in a room under atmospheric pressure, and after 20 hours or 72 hours, it was cured and dried. After heating for a predetermined time, the molded body is taken out of the room and visually observed for the appearance of the upper surface of the molded body before demolding, and the entire surface of the molded body after demolding and the cross section of the bent and cut molded body are visually observed and touched. The molded article was evaluated for appearance and cured drying property according to the following criteria.

Appearance: Abnormalities such as cracks, dents, chips, and film rubbing are not observed on the upper surface of the molded body before demolding and on the entire surface of the molded body after demolding. Δ: Abnormality is slightly observed, but is small. ×: The above abnormality is remarkable. Curing and drying properties ・ ・ ・: The molded product is cured and dried, and is not brittle, the inside is soft, and there is no bubble or void in the cross section. Δ: The molded article was somewhat uncured and undried, and was partially brittle, the inside was soft, and there were bubbles or voids in the cross section. ×: The molded product is uncured and undried, brittle, soft inside, or has bubbles or pores in the cross section.

(2) Heat Sensitivity Test 100 ml of the mortar composition was placed in a 150 ml polypropylene cup, heated at 120 ° C. for 1 hour, and 10 ml of water was poured into the upper part. Was visually inspected to see if the liquid (resin emulsion) had exuded, and evaluated according to the following criteria. ○ ・ ・ ・ No milky liquid exuded into injected water (high thermal effect) × ・ ・ ・ Milk white liquid exuded into injected water (no thermal effect)

[0049]

[Table 1]

[0050]

[Table 2]

Notes in Tables 1 and 2 * 1... The amount of resin emulsion added is indicated by the resin solid content. * 2 ・ ・ ・ Resin emulsion produced in the resin emulsion production example * 3 ・ ・ ・ Resin emulsion produced in the resin emulsion production example * 4 ・ ・ ・ Vinyl acetate-ethylene resin aqueous emulsion (Sumitomo Chemical Industries, Ltd. product) Name Sumikaflex S-
500, resin solids content 55%, Tg of resin = 0 ° C, emulsifier used Nonionic and anionic are used together) * 5 ... Resin emulsion produced in resin emulsion production example * 6 ... Ethylene-vinyl chloride system Resin aqueous emulsion (Sumitomo Chemical Co., Ltd. trade name Sumilite SE-1)
010, resin solid content 50%, resin Tg = 0 ° C, emulsifier used Anionic emulsifier) * 7: NUC Silicone F, trade name of Nihon Unicar Company
Z 2107 (cloud point 53.5 ° C, hydrophilic group polyalkylene glycol) * 8: Dowa Mining Co., Ltd. product name KD-1 * 9 ... Ichi Kasei Co., Ltd. product name Linilite S
B9011 * 10 ··· San Nopco's product name Nopco 8032

[0052]

The mortar composition of the present invention can easily cure and dry its sheet molding or cast by heating at a relatively high temperature for a relatively short period of time without deteriorating its appearance and the like. Thus, molded articles such as sheets and cast articles having excellent appearance and strength can be obtained.

────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Hiroki Takao 3-1-2, Bingo-cho, Chuo-ku, Osaka-shi, Osaka Within Senshu Stream Co., Ltd. (58) Field surveyed (Int. Cl. ⁶ , DB name) C04B 28 / 02 C04B 24/26 C04B 24/42 C04B 24:26 C04B 24:42 C04B 103: 40

Claims (3)

(57) [Claims] 1. A resin aqueous emulsion obtained by polymerizing 100 parts by weight of hydraulic inorganic cement with a nonionic surfactant as a resin solid content of 25 to 85 parts by weight, and a silicone-based surfactant. 0.8 to 100 parts by weight of the resin solid content of the aqueous resin emulsion.
A mortar composition comprising 15 parts by weight. 2. The mortar composition according to claim 1, wherein the silicone-based surfactant is a silicone-based nonionic surfactant. 3. The method according to claim 1, wherein the silicone surfactant is 45 to 85.
The mortar composition according to claim 1, wherein the mortar composition has a cloud point of 10 ° C., and the nonionic surfactant has a cloud point higher than the cloud point of the silicone surfactant by 10 ° C. or more. .