JPS5950061A - Manufacture of cement product - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention uses a thermosetting cementura base material that does not harden during the time required for molding at room temperature, but hardens rapidly when heated. This invention relates to a process for manufacturing cement products with excellent mechanical molding efficiency, in which a hybrid material containing organic or inorganic fibers, casein or its salts, and water as essential raw materials, mixed with a dispersant as necessary, is molded and cured by heating. .

Traditionally, cement molded bodies made by mixing alkali-resistant organic or inorganic fibers with cement have higher bending strength and toughness than those without fibers, so they can be used, for example, as slate boards and GRC boards. It is used as a plate-shaped molded body for various purposes.

However, in order to manufacture molded bodies containing such fibers, special molding methods such as paper making and hand spraying methods are required, and the molding efficiency is low, and flat molded bodies have complicated shapes. It was impossible to manufacture 7 things.

The present inventor aims to solve these drawbacks,
Furthermore, as a result of researching ways to easily and efficiently manufacture molded objects with complex shapes, we developed thermosetting cement, water retention agents,
As a general water-retaining agent, it is effective to mold a kneaded product 7 of alkali-resistant fibers and water using mechanical molding methods such as injection molding, extrusion molding, and press molding, and then heat and harden the mixture. Examples include methylcellulose, pre-treated vinyl alcohol, polyacrylic acid or its salts, polyethylene oxide, etc.
As the shape becomes more complex, it is necessary to add an ice preservative to the eyelids or increase the molding pressure in order to optimize the fluidity of the kneaded product. Therefore, problems such as delayed water utilization reaction of cement and generation of IJ-song remain unresolved.

As a result of further research, the present inventor found that in order to solve this drawback, it is sufficient to make casein or salt present in the mixed product, and the present invention has been completed.

That is, the present invention provides a method for producing a molded product in which a mixed material containing thermosetting cement, alkali-resistant fiber, and water as essential raw materials is molded and cured by heating (in C, casein or its salt is present in the kneaded material). This is a manufacturing method for cement products that is characterized by:

Thermosetting cement as used in the present invention means that even if mixed with water, it will not harden at room temperature for the time required for molding, but at a temperature of about 50'
It is a cement that lacks the property of rapidly hardening and developing strength when heated to a temperature above 0.

Although the hardening of ordinary Portland cement is accelerated by heating and its strength gradually develops, this level of cement is not useful for improving molding efficiency, which is one of the objectives of the present invention.

To produce the thermosetting cement bee of the present invention, a fast-setting 7
This can be obtained by adding a hardening retarder to the cement, which suppresses its rapid hardening but lacks the property of being deactivated by heating.

The fast-setting cement used in the present invention is a cement containing a fast-setting component consisting of calcium aluminate and stone wax, and the calcium aluminate contains C
A, CL2A, C11A7CaF2, C3A
3 Ca5O4, C3A3 CaF2, C3A, etc., and crystalline or amorphous materials of these minerals are used, with amorphous materials being particularly preferred from the viewpoint of rapid hardening. The abbreviations for calcium aluminate are C for CaO and A for Ae.
203.

Examples of the stone wax include dihydrate wax, semi-aquatic wax, and anhydrite wax, and among these, anhydrite wax is preferred.

The ratio of calcium aluminate to gypsum wax is about 0.6 to 3 gypsum wax based on the weight ratio of calcium aluminate. In addition, if it is necessary to further improve quick hardening properties, add CaO or Ca(OH)2 as a third component.
You can add something like that.

When 5 to 40 of these quick-hardening components are added to cement, a quick-hardening cement can be obtained.

Alternatively, a material containing C11A7CaF2, which is commercially available from Onoda Cement Co., Ltd. under the part name "Jet Cement" and stone wax, in the amount of one quick hardening agent, can also be used.

When such a fast-setting cement is mixed with water, it immediately starts to harden, so if the hardening is delayed for a certain period of time and heated at the same time, the hardening retarding effect is deactivated in a short period of time, and the quick-hardening effect is lost. It is necessary to use a curing retarder with a restoring effect.

Specific examples of such retardants include citric acid, lactic acid,
Hydrocarbons such as tartaric acid, gelconic acid, succinic acid, maleic acid, etc.
Roxylic acids include organic acids such as phosphoric acid, dicarpic acid, unsaturated fatty acids, salts thereof, alkali carbonates, phosphoric acids or salts thereof, boric acid, silicofluorides, and mixtures thereof.

The alkali-resistant fibers used in the present invention include organic fibers such as polyethylene, polypropylene, vinyl chloride, and polyvinyl alcohol, asbestos, alkali-resistant glass fibers,
Are inorganic fibers such as carbon fibers degraded by the alkali in cement? It is difficult to accept. The amount of these alkali-resistant fibers mixed into the thermosetting cement depends on the type of fiber, required bending strength, molding method, etc.
An appropriate amount is set as appropriate. For example, when hot press molding, the amount of alkali-resistant glass fiber mixed is 2 to the solid content.
~10%, and when extrusion molding, the asbestos content is 5~1
5 inches is preferable.

The main feature of the present invention is the use of casein or a salt thereof as a moldability improving agent, which produces the following effects.

The fluidity of the mixed material becomes appropriate, which improves the flow inside the molding machine and improves efficiency, and even when molded at high pressure, no precipitating water is generated, making it possible to manufacture more complex molded objects. The strength development of the cured product is not impaired in any way.

Any casein or its salt can be used as long as it can be dispersed and dissolved in the mixed substance.

Casein salts include sodium 1π and the like. The amount added is 0 to thermosetting cement.
．． The number is about 1 to 10, preferably 2 to 6. For example, when milk casein is used, a normal molded body (J
Adding about 5% of casein improves fluidity and improves molding efficiency, but if the shape becomes rough, this addition amount cannot prevent the molding from forming, and it is necessary to increase the molding pressure and the amount of casein added. In the present invention, approximately 1-4% of thermosetting cement is suitable, and 10%'
Even if a large amount of tY is added, the effect is almost the same and it is not economically preferable.

Kneadability? To further increase the temperature, it is effective to use solvents such as 1P, triethanolamine, and dispersants such as sodium acrylate and cement water reducers.

In particular, high performance water reducing agents such as sodium acrylate, sulfonated products of melamine formaldehyde condensates, and naphthalene sulfonic acid formaldehyde cocondensates are highly effective and do not impair curing properties, so good results can be obtained. .

For molding, first, the predetermined materials are mixed in a bimortar mixer to create a mixture having a softness (fluidity) of 7 suitable for the molding machine. When mixing, it is preferable to first knead the materials other than the alkali-resistant fibers to form the mortar 7, and then finally disperse them throughout the entire prisoner. The hybrid material obtained in this way is usually in the form of a plastic material such as a paste or mortar, but it can also be produced as a powder depending on the molding method. As the crosstalk machine,
In addition to the mortar mixer, a Nigu type mixer used for mixing plastic raw materials may be used, and there are no restrictions on the mixing means.

The kneaded product usually has a hardness of 10 to 10
It does not harden for 60 minutes and can maintain a taut state during molding. In the present invention, such a kneaded material is molded in the above-mentioned uncured state f and cured by heating. Mold using mold 7. (2) Warm after molding. (3) Molding by any method such as heating the kneaded material to an acceptable level and molding.

11il before molding the mixed wire! As an auxiliary means to prevent the kneaded material from freezing, the kneaded material may be kept in a frozen state below a certain temperature, or in some cases below a temperature of 0'C, but generally it is kept at a temperature below 20°C. By doing so, it is possible to prevent curing for the required time due to the action of the curing retarder.

In order to mold the kneaded product, a molding machine 7 such as an injection molding machine, an extrusion molding machine, or a press may be used, but in this case, heating molding is preferable. That is, in injection molding and press molding, mixed wire injection is performed using a heated mold, and when pressing, molding and heating are performed at the same time. In addition, in the case of extrusion banding, heat the vicinity of the tip of the extrusion die for the mixed wire, or
The molded product immediately after extrusion may be molded by passing it through a heating door.

Heating the mixed material at a temperature of 50 to 100°C1, especially 60 to 80°C
It is preferable to rapidly raise the temperature to .degree. For this purpose,
A simple method is to keep the mold at a predetermined temperature. Also, after extrusion molding of the mixed wire material, it is heated through a heating zone.

In this case, it is preferable to use an atmosphere with a temperature of 100° C. or higher.

The uncured molded body heated to 50 to 100°C begins to harden rapidly, and usually reaches the strength necessary for removing the frame within 10 minutes.

The unframed strength varies depending on the thickness and shape of the molded body, so in order to achieve the required strength, it is adjusted by adjusting the blend of raw materials used, the amount of curing components, the amount of curing retarder, etc.

The molded product that has been removed from the frame mirrors the surface texture of the mold, making it possible to create precise and complex shapes that were impossible with conventional cement product manufacturing methods.

In addition, the mixed material is supplied to the mold in a deaerated state and is cured in a compacted state, making it possible to produce a molded body with low porosity and high strength.0 Post-curing of the molded body is usually As with cement products, air dry,
It can be cured in steam or water. However, in the case of air-dry curing, good results can be obtained by avoiding rapid drying and keeping it moist.

Hereinafter, the present invention will be further explained in detail with reference to Example 7al. Note that all parts and percentages described in this specification are expressed on a weight basis.

Using raw material composition 7 shown in the example table, in a 5/5 mortar mixer,
First of all, is it a material other than alkali-resistant glass fiber? The mortar was made by adding the fibers, and then the mixed wire was made by adding the fibers. The physical property measurement results of the interfering material are shown in the χ table. The measurement method for each physical property is as follows.

(1) Formability: Place between iron plates heated to 70°C and press to a thickness of 5 mm. (2) Pot life at room temperature: Kneaded product (kneading temperature: 21°O) & Time from the start of kneading to the start of hardening when held in an atmosphere of 20°C = When pressed with an iron plate heated to 70°C - Hardening required for mold filling and de-framing (bending strength of approx. 30Qf/Crr
The time it takes to wake up L2).

f3) 28-day bending strength After heating and molding, the cured product was removed from the frame and cured for 7 days while moisturizing in a room at a temperature of 20° C. After air-drying until 28 days, 7 test pieces were cut out and the bending strength was measured.

Margin below (11) (Note) Sodium caseinate.

(16) (12) The product manufactured according to the present invention had a glossy surface, but the product manufactured in the comparative example had six grooves caused by pleating water and needed to be repaired.

Patent applicant Denki Kagaku Kogyo Co., Ltd.

Claims (1)

[Claims] A cement product characterized by the presence of casein or its salt in a method for producing a molded product in which thermosetting cement, alkali-resistant fiber, and a mixed material as essential raw materials are molded and cured by heating. Manufacturing method.