JP2640558B2 - Lightweight body composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present application relates to a composition which can be cured by water and dried at an early stage to obtain a lightweight body excellent in fire resistance, heat insulation, water resistance and the like, and the composition More particularly, the present invention relates to a method for manufacturing a lightweight body suitably used as a lining refractory material or a heat insulating material for various materials such as wall materials in the field of construction.

(Prior Art) Conventionally, various lightweight materials have been used in various industrial fields. For example, in the construction field, ALC panels, perlite mortar, rock wool, glass wool, urethane foam, foam glass, other lightweight panels, and the like are used as appropriate according to the intended use. In particular, rock wool or foamed urethane is generally used as a backing refractory material for non-bearing walls (curtain walls) of outer walls, a backing material for metal siding, and a core material. As a special example, water glass is used as an adhesive and pearlite is used. Fixed foam particles such as
A room temperature foaming type material such as foaming mortar may be used.

(Problems to be solved by the invention) However, among the current lightweight bodies, the bulk density is 0.6 g / c.
m ³ or less, the compression strength of 5 kgf / cm ² or more, a fireproof, fire resistance, workability, especially excellent in workability and drying of the in situ, without the need for special manufacturing equipment, and inexpensive The material has not yet been developed and its development is desired.

That is, pearlite mortar has a high bulk specific gravity, and rock wool and glass wool have a problem in strength. Urethane foam and styrene foam have a problem in fire resistance, and molded plates such as foam glass, ALC panels, and silica plates require special equipment for production.

In general, the following methods are conceivable for producing a lightweight material.

The first is a method of foaming the material itself to reduce its weight. However, in this method, it is difficult to control the thickness, and it is also difficult to make the surface flat. Further, since it is a foamed material, there are drawbacks such as a problem of pot life and difficulty in thickening.

Secondly, the material is made porous by adding a foaming agent or increasing the amount of kneading water to reduce the weight. However, an increase in the amount of kneading water causes a decrease in the drying speed. In addition, there is a natural limit to weight reduction by using only internal air bubbles.

Thirdly, the method of adding lightweight aggregate, but if a large amount of lightweight aggregate is added, some of itself absorb water,
In some cases, the required amount of kneading water may increase, or if too little lightweight aggregate is added, kneading may not be possible, or if pumping is used for pumping, the material is easily separated from water in the hose, making it difficult to pump. It may be.

As described above, according to the conventional method, it is necessary to solve the conflicting problems of being lightweight, having a strength equal to or higher than a certain level, and drying quickly, and development of a material for solving those problems has been awaited. Had been.

(Method of Solving the Problems) The inventor of the present invention has intensively studied to solve the above problems, and a lightweight body satisfying the above conditions can be obtained with hydraulic cement and a lightweight aggregate having a bulk density of 0.6 g / cm ³ or less. As a result of further investigation, it was found that if a specific water-soluble resin is used, even if the amount of the lightweight aggregate is very large, the amount of the binder and the amount of water added (mixing water amount) can be reduced with a normal mixer. We found that we could knead and work without breaking.

That is, (a) hydraulic cement, (b) a lightweight aggregate having a bulk density of 0.6 g / cm ³ or less, (c) ethylhydroxyethylcellulose as an active ingredient, (a) 100 kg, (b) 0.3 to 1.5 m ³ , (c) 0.1 to 10 kg.

To mix these components, first, a mixture of components excluding the lightweight aggregate is kneaded with water, and then the lightweight aggregate is added and kneaded. This is sprayed onto the parts that require fire resistance and heat insulation, coated with ironing, filling, etc., and then dried and used as it is. , Light body.

Here, hydraulic cement used in the present invention is generally known cement such as Portland cement, alumina cement, lime mixed cement, blast furnace cement, silica cement, fly ash cement, masonry cement and high sulfate slag cement. Include.
These provide strength to the lightweight body.

Next, lightweight aggregates are foams of natural minerals or synthetics,
Alternatively, a substance formed by expansion and having a bulk density of 0.6 g / cm ³ or less is shown here. The particle size is not particularly limited, but when used for spraying, it is preferably about 10 mm or less to the extent that the spray nozzle is not clogged. Specifically, it refers to expanded perlite, expanded shale, expanded vermiculite, pumice, and the like, as well as expanded silica gel and granulated and expanded clay. It is particularly desirable that the foam is composed of many bubbles and has a low bulk density (0.3 g / cm ³ or less), and examples thereof include expanded perlite, shirasu balloon, and expanded vermiculite of perlite. The proportion of these lightweight aggregates in the composition is 0.3 to 100 kg of hydraulic cement.
It is a 1.5m ^3. If it is less than 0.3 m ^3, the object of the present invention cannot be reduced in weight, and if it exceeds 1.5 m ³ , the mechanical strength of the obtained lightweight body becomes brittle, poor adhesion, insufficient surface strength. For example, peeling and breakage occur, which is not preferable.

Ethylhydroxyethylcellulose used in the present invention is effective when it is made into an aqueous solution and has a structural viscosity, and more desirably, it forms bubbles during water-kneading and does not break easily for a relatively long time after standing. . The addition amount of this ethyl hydroxyethyl cellulose is 0.1 to 10 kg, and particularly preferably 0.1 to 10 kg, per 100 kg of hydraulic cement.
5 to 5 kg. If the weight is less than 0.1 kg, the lightweight aggregate is broken during kneading, and the bulk density increases. If the weight is more than 10 kg, uniform kneading cannot be performed.

In the present invention, various components other than the above components may be further added.

For example, gluconic acid, citric acid, lactic acid, malic acid, succinic acid, tannic acid, salicylic acid and the like can be mentioned. These are intended to prevent aluminum from being corroded by alkali components of hydraulic cement in the components when the lightweight body composition of the present invention is used as a refractory material for lining aluminum curtain walls.

Further, a synthetic resin emulsion or a synthetic resin emulsion powder can be further added to the composition of the present invention as long as the fire resistance and the fire resistance are not impaired. Synthetic resin emulsion, acrylic acid ester, versatic acid ester, styrene, vinyl chloride, vinyl acetate and the like can be exemplified as typical substances, among which ethylene-vinyl acetate-based and vinyl acetate-vinyl versatate-based resins, It is most preferable because of its good affinity with hydraulic cement and because it is easily available as an industrial product. In the present invention, by adding a synthetic resin emulsion to improve the adhesion to the substrate, and also to improve the surface strength,
Various advantages such as maintaining the finish stability over a long period of time are provided.

In addition, if necessary, fillers such as refractory clay, refractory oxides, silica sand, lime, etc., powders such as glass fiber, rock wool, pulp fiber, etc. An appropriate amount of a surfactant such as a surfactant as an adjusting material can be added as long as the fire resistance is not impaired and the mechanical strength and adhesion are not reduced.

The lightweight body composition of the present invention comprises the above-mentioned components. In the manufacturing method, first, among these components, each component except the lightweight aggregate is kneaded with water, and then the lightweight aggregate is added. And kneading. This is because if the lightweight aggregates are mixed and kneaded from the beginning, these lightweight aggregates absorb water, so that the amount of added water increases, resulting in problems such as slow drying.

(Effect) The lightweight body composition of the present invention can knead a large amount of unusually large amount of lightweight aggregate with a small amount of binder. Although the reason for this is not clearly understood, it is thought to be due to the viscosity of ethyl hydroxyethyl cellulose and the property of retaining bubbles. That is,
Normally, there are many lightweight aggregates, and the aggregates are crushed when agitated by a mixer or the like, and the bulk density becomes large.In the present invention, however, the shear stress is applied to the aggregates because the ethyl hydroxyethyl cellulose holds the air bubbles. It is considered that when the shear stress increases due to the structural viscosity, the viscosity decreases and the mixing becomes easy. In the present invention, when using such ethyl hydroxyethyl cellulose in a specific numerical range,
This is possible for the first time.

Hereinafter, the present invention will be described with reference to examples and comparative examples.

Preparation of Test Specimen After weighing the blended powder excluding the lightweight aggregate, kneading with a mortar mixer to prepare a uniform mixed powder, and adding an appropriate amount of water thereto. At this time, if there is a liquid additive, it is kneaded after the simultaneous addition. The lightweight aggregate is put into a mortar mixer, and the kneaded material previously mixed is poured into a mortar mixer and stirred. Part of the fabricated material is a mold (40m) specified in JIS A 5210 for measuring bulk density and compressive strength.
m × 40mm × 160mm), cured in a curing room at a temperature of 20 ° C. and a humidity of 65% for 2 days, demolded, cured in the same manner for 26 days, cured for a total of 28 days, and did.

Meanwhile, a hot-rolled steel plate (300 mm x 300 mm x 5 mm) with a thickness of 2 mm
The sample applied to 0 mm is used as a test specimen for tracking the drying speed.

Bulk density The bulk density of the test specimen was measured using a caliper to measure the external dimensions of the bulk test specimen cured under the above conditions, determine the volume (V), measure the weight (W), and calculate the bulk density using the following formula. Ask by

Compressive strength The above test specimen is measured by pressing it with a pressure plate of 40 mm × 40 mm. The pressurizing speed was in principle 1-2 kgf / sec. The compression speed is obtained from the maximum load at the time when the test piece breaks, by the following formula.

Drying speed The specimen prepared above was placed in a curing room at 20 ° C and 65%,
Follow the weight loss until the weight does not change. The weight loss rate was determined from the following equation.

Table 1 shows each component used in each example.
Table 2 shows examples in which they were blended, and Table 3 shows comparative examples. The drying speed is shown in FIG.

Example 1 0.3 kg of ethyl hydroxyethyl cellulose was mixed with 10 kg of Portland cement in a powder state, and kneaded with 8 kg of water with a hand mixer to form a uniform slurry.
The mixture was kneaded for 1 minute in a bread mortar mixer in which expanded vermiculite 100 was previously placed. The kneaded materials were prepared in the above-described specimens, and the physical properties were measured after the above-described conditions. As a result, a lightweight body having a bulk density of 0.25 g / cm ³ and a compressive strength of 5.7 kgf / cm ² was obtained. With this lightweight body
When a base material test and a surface test were carried out in accordance with JIS A 1321 "Test method for flame retardancy of building interior materials and construction methods", data equivalent to flame retardant class 1 were obtained. The thermal conductivity was 0.085 (kcal / mhr ° C).

(Example 2) Expanded bomiculite 100 which is the lightweight aggregate of Example 1
Was changed to expanded perlite 75, and after kneading time was 5 minutes, various physical properties were measured.
A lightweight body having a compressive strength of 12.1 kgf / cm ² and a compressive strength of 35 g / cm ³ was obtained. A base material test and a surface test were performed on this lightweight body in accordance with JIS A 1321 “Testing method for flame retardancy of building interior materials and construction methods”, and data equivalent to flame retardant class 1 were obtained.
The thermal conductivity was 0.070 (kcal / mhr ° C).

(Example 3) Expanded perlite 75 of Example 2 was replaced with expanded perlite 50.
In addition, except that the amount of ethyl hydroxyethyl cellulose was changed from 0.3 kg to 0.1 kg, a light body having a bulk density of 0.40 g / cm ³ and a compressive strength of 15.0 kgf / cm ² was obtained. A base material test and a surface test were performed on this lightweight body in accordance with JIS A 1321 “Testing method for flame retardancy of building interior materials and construction methods”, and data equivalent to flame retardant class 1 were obtained. The thermal conductivity was 0.075 (kcal / mhr ° C).

(Comparative Example 1) When physical properties were measured in the same manner as in Example 2 except that ethyl hydroxyethyl cellulose was changed to sodium polyacrylate, the bulk density was 1.00 g / cm ³ , and expanded pearlite was significantly crushed. Compressive strength is 43.4kgf / cm
^{Was 2} .

(Comparative Example 2) When physical properties were measured in the same manner as in Example 2 except that the amount of expanded pearlite was reduced, the bulk density was 0.86.
g / cm ^3, which was heavy. The compressive strength is 30.
It was 7 kgf / cm ² .

(Comparative Example 3) Kneading was attempted in the same manner as in Example 2 except that the amount of expanded perlite was changed to 200, but uniform kneading was impossible. The test piece was prepared by pouring it into the mold in this non-uniform state, but it was brittle and collapsed, and the measurement could not be performed.

(Comparative Example 4) When properties were measured in the same manner as in Example 2 except that the ethylhydroxyethyl cellulose was removed, the expanded perlite was crushed, and a bulky one having a bulk density of 1.15 g / cm ³ was obtained. . The compressive strength was 51.5 kgf / cm ² .

(Comparative Example 5) When physical properties were measured by a general formulation of a wet rock wool refractory coating material, the bulk density was 0.53 g / cm ³ and the compressive strength was 4.0.
kgf / cm ² .

(Comparative Example 6) When the physical properties were measured in the same manner as in Example 3 except that the ethyl hydroxyethyl cellulose was changed to hydroxyethyl cellulose, the bulk density was 0.96 g / cm ³ ,
The compressive strength was 10.9 kgf / cm ² .

(Comparative Example 7) The same operation was performed except that the ethyl hydroxyethyl cellulose of Example 3 was changed to polyvinyl alcohol. However, the viscosity was low at the time of kneading.

(Comparative Example 8) The same operation was performed except that the ethylhydroxyethylcellulose of Example 3 was changed to carboxymethylcellulose. However, since the viscosity was low at the time of kneading, the mixture became crisp and it was difficult to form a molded article.

(Comparative Example 9) When the physical properties were measured in the same manner as in Example 3 except that the ethyl hydroxyethyl cellulose was changed to methyl cellulose, the bulk density was 0.83 g / cm ³ and the compressive strength was 1
It was 1.6 kgf / cm ² .

(Effect) FIG. 1 shows the relationship between the number of elapsed days and the weight loss rate in order to show the difference in the drying speed. As can be seen, the amount of kneading water occupying a certain volume is smaller than that of wet rock wool, so that the drying speed is high, and because the lightweight aggregate is crushed by stirring with a mixer, it is out of the specific range of the present invention. While the method has a high bulk density, the present invention produces a molded body with a low bulk density.
On the other hand, Comparative Example 3 was considered to have a low bulk density, but kneading was impossible.

Thus, the present invention has light weight, fire resistance, heat insulation,
It is an excellent composition that can be shortened during construction because it dries quickly. In addition, due to such characteristics, in addition to backing materials for non-bearing walls (curtain walls) of buildings, fire-resistant covering materials for steel frames, external insulation methods for outer walls and other heat insulation fields, core materials for fire doors, sand It is a very useful composition that can be widely applied to core materials for panels, fire-resistant insulation layers for fire-resistant safes, fire-resistant insulation fillers for various plants, cushioning materials for packaging, and the like.

[Brief description of the drawings]

 FIG. 1 shows a comparison of drying rates. A: Number of days elapsed (days) B: Weight loss rate (%) C: Example 1 D: Example 2 E: Comparative example 5

Claims (2)

(57) [Claims] (1) Hydraulic cement, (b) lightweight aggregate having a bulk density of 0.6 g / cm ³ or less, (c) ethylhydroxyethylcellulose as an active ingredient, (a) 100 kg, (b) A lightweight body composition characterized by being blended at a ratio of 0.3 to 1.5 m ³ , (c) 0.1 to 10 kg. 2. A method for producing a lightweight body, comprising: kneading and kneading components of the composition according to claim 1 except for a lightweight aggregate, and adding a lightweight aggregate thereto. .