JPH03275549A - Lightweight composition - Google Patents

Abstract

PURPOSE:To reduce weight and to improve fire resistance, heat insulating property and dryability by incorporating hydraulic cement, specified lightweight aggregate and ethylhydroxyethylcellulose. CONSTITUTION:Ethylhydroxyethylcellulose is added to hydraulic cement by 0.1-10kg per 100kg of the cement, they are kneaded with water and then lightweight aggregate having <=0.6g/cm<3> bulk density and <=10mm diameter, e.g. expanded perlite is added by 0.3-1.5m<3> to obtain a lightweight compsn. An org. acid such as citric acid, a synthetic resin emulsion such as an ethylene vinyl acetate resin emulsion and a filler such as fireproof clay are further added as required.

Description

Detailed Description of the Invention (Industrial Application Field) The present application provides a composition that hardens with water and dries quickly, and provides a lightweight body with excellent fire resistance, heat insulation, water resistance, etc., and the composition. The present invention relates to a method for manufacturing a lightweight body suitable for use as a fireproof material or heat insulating material for lining various materials such as wall materials in the construction field.

(Prior art) Various lightweight materials have been used in various industrial fields. For example, in the construction field, ALC panels, perlite mortar lath wool, foamed urethane, foam glass, and other lightweight panels have been used in various industries. It is used as appropriate depending on the purpose. In particular, rock wool and urethane foam are commonly used as fireproof lining materials for non-load-bearing external walls (curtain walls), and as lining materials and core materials for metal siding. Examples include materials with fixed foam particles, such as foaming granules, and room-temperature foaming materials such as foaming mortar.

(Problem to be solved by the invention) However, among the current lightweight bodies, the bulk density is 0.6g.
/cm3 or less, compressive strength of 5 kgf/c4 or more, fireproofing and fire resistance, excellent workability, especially on-site workability and drying, does not require special manufacturing equipment, and is inexpensive. The material has not yet been developed, and its development is desired.

In other words, perlite mortar has a high bulk specific gravity, rock wool and glass wool have problems with their strength, urethane foam and styrene foam have problems with fire protection, and molded plates such as foam glass, ALC panels, and skeletal boards are difficult to manufacture. Requires special equipment.

In general, the following methods can be considered for making lightweight materials.

The first method is to foam the material itself to make it lighter.

However, with this method, it is difficult to control the thickness and it is also difficult to make the surface smooth. In addition, since it is a foam material, it has drawbacks such as pot life problems and difficulty in applying thickness.

The second method is to make the material porous to reduce weight by adding a foaming agent or increasing the amount of kneading water, but increasing the amount of kneading water causes a decrease in the drying speed.

Furthermore, there is a limit to how much weight can be reduced by using internal air bubbles alone.

Thirdly, there is a method of adding lightweight aggregate, but if a large amount of lightweight aggregate is added, some of it may absorb water by itself, which may increase the amount of water required for mixing. If too much is added, it may become impossible to knead, or when pumping, the material and water may easily separate in the hose, resulting in a material that is difficult to pump.

In this way, with conventional methods, it is necessary to solve the mutually contradictory problems of being lightweight, having strength above a certain level, and drying quickly, and the development of materials that solve these problems is awaited. It was.

(Method for Solving the Problems) The present inventor has conducted extensive research to solve the above problems, and has found that a lightweight body that satisfies the above conditions can be obtained by using hydraulic cement and lightweight aggregate with a bulk density of 0.6 g/cj or less. As a result of further investigation, we found that by using a specific water-soluble resin, even if the amount of lightweight aggregate is very large, it is possible to mix lightweight aggregate with a normal mixer using a small amount of binder and a small amount of water (kneading water amount). It was discovered that it can be kneaded and constructed without damaging it.

That is, (a) hydraulic cement, (b) lightweight aggregate with a bulk density of 0.6 g/cm3 or less, (c
) Contains ethyl hydroxyethyl cellulose as an active ingredient, (a) per 100 kg, (b) 0.3 to 1.5, (c) 0. 1=10kg.

It is a composition that is blended in such a ratio that

To blend these components, first, a mixture of the components excluding the lightweight aggregate is kneaded with water, and then the lightweight aggregate is added and kneaded. This can be sprayed, troweled, filled, or otherwise used to cover areas that require fire resistance and heat insulation, and then dried and used as is, or poured into a mold, dried, hardened, and then removed from the mold to form a plate. , lightweight body.

Here, the hydraulic cement used in the present invention is
It includes commonly known cements such as portland cement, alumina cement, lime mixed cement, blast furnace cement, silica cement, fly ash cement, masonry cement, high sulfate slag cement, etc. These provide strength to lightweight bodies.

Next, the term "lightweight aggregate" refers to a material formed by foaming or expanding natural minerals or synthetic materials, and here indicates one having a bulk density of 0.6 g/cj or less. The particle size is not particularly limited, but when used for spraying, it is preferably about 10 mm or less so as not to clog the spray nozzle.

Specifically, it refers to expanded pearlite, expanded shale, expanded vermiculite, pumice, etc., as well as foamed silica gel and granulated and foamed clay. Particularly preferably, the material consists of many bubbles and has a small bulk density (0.3 g/(d or less)), such as expanded pearlite of pearlite type, shirasu balloon, and expanded vermiculite. The proportion of the material in the composition is 0.3 to 1.5 M per 100 kg of hydraulic cement. If it is less than 0.3 M, the weight reduction that is the objective of the present invention cannot be achieved. l, 5t
If it exceeds d, the mechanical strength of the obtained lightweight body becomes brittle, and peeling and breakage occur due to poor adhesion and insufficient surface strength, which is not preferable.

The ethyl hydroxyethyl cellulose used in the present invention is
Ethyl hydroxyethyl cellulose is effective if it has structural viscosity when made into an aqueous solution, and more preferably, it should form bubbles when mixed with water and be difficult to break for a relatively long time even after being left to stand.The amount of ethylhydroxyethyl cellulose to be added is Hydraulic cement 1
0.00 kg, 0.1 to 10 kg, particularly preferably 0.5 to 5 kg. If it is less than 0.1 kg, the lightweight aggregate will break during kneading and the bulk density will increase, and if it is more than 10 kg, uniform kneading will not be possible.

In the present invention, various components may be further added in addition to the above components.

Examples include gluconic acid, citric acid, lactic acid, malic acid, succinic acid, tannic acid, and salicylic acid. The purpose of these is to prevent aluminum from being corroded by the alkali content of the hydraulic cement when the lightweight body composition of the present invention is used as a fireproof material for lining an aluminum curtain wall.

In addition, the composition of the present invention may contain a synthetic resin emulsion or
Synthetic resin emulsion powder can be further added within a range that does not impair fireproofing properties and fire resistance. Representative examples of synthetic resin emulsions include acrylic esters, versatinic acid esters, styrene, vinyl chloride, vinyl acetate, etc. Among them, ethylene-vinyl acetate-based and vinyl acetate-vinyl persatate-based resins are It is most preferred because of its good affinity with hydraulic cement and because it is difficult to obtain as an industrial product. In the present invention, the addition of a synthetic resin emulsion improves adhesion to the substrate, improves surface strength, and provides various advantages such as maintaining finish stability for a long period of time.

Furthermore, if necessary, powders such as fireclay, fireproof oxide, silica sand, and lime can be used as additional materials, and fibrous materials such as glass fiber, rock wool, and pulp fiber can be used as crack prevention materials for the hardened coating layer. A suitable amount of a surfactant as a flow regulating agent can be added within a range that does not impede fire resistance or reduce mechanical strength or adhesion.

The lightweight body composition of the present invention is made of the above-mentioned components.The manufacturing method thereof is to first knead each of these components except for the lightweight aggregate with water, and then add the lightweight aggregate. This is done through a step of kneading. This is because if lightweight aggregates are mixed and kneaded from the beginning, these lightweight aggregates absorb water, which increases the amount of water added, resulting in problems such as slow drying. Because it happens.

(Function) In the lightweight body composition of the present invention, a large amount of lightweight aggregate that is not normally used can be kneaded with a small amount of binder. Although the reason for this is not clearly known, it is thought that it may be due to the viscosity of ethylhydroxyethylcellulose and its ability to retain air bubbles. In other words, normally, since there is a large amount of lightweight aggregate, when it is stirred with a mixer, the aggregate is crushed and the bulk density increases, but in the present invention, the air bubbles are retained by ethyl hydroxyethyl cellulose, so the shear stress is reduced. It is difficult to add to the aggregate, and since it has structural viscosity, -e shear stress is large (this is thought to be because the viscosity decreases and it becomes easier to mix. In the present invention, such ethyl hydroxy This becomes possible for the first time when ethylcellulose is used within a specific numerical range.

(Example) The present invention will be described below with reference to Examples and Comparative Examples.

■Production method of test specimen After weighing the blended powder excluding the lightweight aggregate, dry knead it with a mortar mixer to prepare a uniform mixed powder, and add an appropriate amount of water to this. If liquid additives are present at this time, they are added at the same time and then kneaded. Light aggregate is put into a mortar mixer, and the previously kneaded mixture is poured into the mortar mixer and stirred.

A part of the prepared material was placed in a mold (40s
+mX 40m5X 160mm), temperature 2
After curing in a curing room at 0°C and 65% humidity for 2 days, the mold was removed, and then cured in the same manner for 26 days, for a total of 28 days, to form a test specimen.

On the other hand, hot rolled steel plate (300mm x 300 plow m x 5)
The sample coated to a thickness of 20 mm was used as a test piece for tracking drying speed.

■Bulk Density The bulk density of the test specimen is determined by measuring the external dimensions of the bulk density test specimen cured under the above conditions with calipers, determining the volume 11 (V), and measuring the weight (W), and calculating the bulk density as shown below. Calculated using the formula.

Measurement is carried out by compressing the test specimen described in Section 2 of "Compressive Strength" with a 405m x 40cm pressure plate.As a general rule, the compression speed is 1 to 2 kg for 17 seconds. Calculate using the following formula from the maximum load at that time.

■Drying rate The test specimen prepared in the above (■) was kept in a curing chamber at 20°C and 165%, and the weight loss was followed until the weight stopped changing.

The weight reduction rate was determined from the following formula.

Table 1 shows each component used in each example. Comparative examples are shown in Table 2, and examples of blending using these are shown in Table 2.
Shown in 3. Furthermore, the drying rate is shown in Figure 1.

(Example 1) 0.3 kg of ethyl hydroxyethyl cellulose was mixed in powder form with 10 kg of Portland cement.
The mixture was kneaded with 8 kg of water using a hand mixer to form a uniform slurry. Pre-expanded vermiculite 10
The mixture was kneaded for 1 minute using a pan-shaped mortar mixer containing 0.01. The kneaded material was prepared into test specimens as described above, and the physical properties were measured under the aforementioned conditions. As a result, the bulk density was 0.
．． 25g/cj, compressive strength is 5. 7kgf/c
- A lightweight body was obtained. JIS A with this lightweight body
When base material tests and surface tests were conducted in accordance with ``1321r Flame Retardant Test Methods for Building Interior Materials and Construction Methods'', data equivalent to Class 1 flame retardant were obtained. Further, the thermal conductivity was 0.085 (kcal/mhr'C).

(Example 2) Expanded vermiculite 1OO, which is the lightweight aggregate of Example 1
1 was replaced with expanded pearlite 75N, and after kneading for 5 minutes, various physical properties were measured, and the bulk density was 0.
．． A lightweight body with a compressive strength of 35 g/cm3 and a compressive strength of 12.1 kgf/c- was obtained. JIS A 132 with this lightweight body
When a base material test and a surface test were conducted according to the flame retardant test method J of 1R Building Interior Materials and Method 2, data equivalent to class 1 flame retardant was obtained. Also, the thermal conductivity is 0.
It was 070 (kcal/餉hr 'C).

(Example 3) Expanded barley of Example 2) 7! M! expanded perlite 5
01 and ethylhydroxyethylcellulose to 0.01.
When the same procedure was carried out except that the weight was changed from 3 kg to 0.1 kg, the bulk density was 0.40 g/C-1 compressive strength was 15.
A lightweight body of 0 kgf/c- was obtained. When this lightweight body was subjected to a base material test and a surface test in accordance with JIS A 1321r Flame Retardant Test Method for Building Interior Materials and Construction Methods, data equivalent to class 1 flame retardant was obtained.

In addition, the thermal conductivity is 0.075 (kcal/mhr
'C).

(Comparative Example I) When various physical properties were measured in the same manner as in Example 2 except that the ethyl hydroxyethyl cellulose was changed to sodium polyacrylate, the bulk density was 1.00 g / cd,
Expanded perlite was severely crushed. Compressive strength is 4
It was 3.4 kgf/c-.

(Comparative Example 2) Except for reducing the amount of expanded pearlite added in Example 2,
When various physical properties were measured in the same manner, the bulk density was 0.86.
The compressive strength of something as heavy as g/cm3 is
It was 30.7 kgf/c-.

(Comparative Example 3) Kneading was attempted in the same manner as in Example 2 except that the amount of expanded pearlite added was 200 strain, but uniform kneading was not possible. A test specimen was prepared by pouring the mixture into a mold in this non-uniform state, but it was too brittle and collapsed, making it impossible to measure it.

(Comparative Example 4) When various physical properties were measured in the same manner as in Example 2 except that ethylhydroxyethylcellulose was removed, the expanded pearlite was crushed and the bulk density was 1.15 g/cj.
I made something heavy. The compressive strength is 51.5kg
It was f/c-.

(Comparative Example 5) When various physical properties were measured using a general formulation of a wet-type wool fireproof coating material, the bulk density was 0.53 g/cj, and the compressive strength was 4.0 kgf/c-.

(Comparative Example 6) Various 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/cj, and the compressive strength was lo, 9 kgf/(-). there were.

(Comparative Example 7) The same procedure as in Example 8 was performed except that the ethyl hydroxyethyl cellulose in Example 3 was changed to polyvinyl alcohol.
Due to its low viscosity during kneading, it became dry and easily crushed, making it difficult to form into a molded product.

(Comparative Example 8) When the same procedure as in Example 3 was carried out except that the ethyl hydroxyethyl cellulose was changed to carboxymethyl cellulose, it became dry due to the low viscosity during kneading, and it was difficult to form a molded product (Comparative Example 9) ) fruit! Physical properties were measured in the same manner as in Example 3 except that methyl cellulose was used instead of ethyl hydroxyethyl cellulose. The bulk density was 0.83 gZC-, and the compressive strength was 11.6 kgf/cm3.

(Effect) In order to show the difference in drying speed, Figure 1 shows the relationship between the number of days elapsed and the weight loss rate. As can be seen from this, since the amount of kneading water in a given volume is smaller than that of wet rock wool, the drying speed is faster, and the crushing of the lightweight aggregate due to stirring in the mixer causes problems outside the specific scope of the present invention. Whereas the method produces a high bulk density, the present invention produces a molded body with a low bulk density.

On the other hand, Comparative Example 3 is thought to have a smaller bulk density, but
Crosstalk was impossible.

As described above, the present invention is an excellent composition that is lightweight, has fire resistance and heat insulation properties, and dries quickly during construction, thereby shortening the construction period. Due to these characteristics, it is also used as lining materials for non-load-bearing walls (curtain walls) in buildings, fireproof coatings for steel frames, external insulation methods for exterior walls, other insulation fields, core materials for fire doors, and sunscreens. It is an extremely useful composition that can be widely applied to the core material of i' panels, the fireproof insulation layer of fireproof safes, the fireproof insulation filler of various plants, the soyon material for packaging, etc.

(Margin below) table ■ table

[Brief explanation of drawings]

Figure 1 shows a comparison of drying rates. A---Number of days that have passed (days) B--1 Weight reduction rate (%) C---1 Example I D ----- Example 2 E --- Comparative example 5

Claims (2)

[Claims] (1) (a) Hydraulic cement, (b) Lightweight aggregate with a bulk density of 0.6 g/cm^3 or less, (
c) Use ethyl hydroxyethyl cellulose as an active ingredient, and mix it in a ratio such that (a) 100 kg, (b) 0.3 to 1.5 m^2, (c) 0.1 to 10 kg. Features a lightweight body composition. (2) A method for manufacturing a lightweight body, which comprises: adding water to the composition of the composition according to claim 1, excluding the lightweight aggregate; and then kneading the composition with the addition of the lightweight aggregate.