JPS6236056A - Additive for extrusion forming - 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] [Industrial application field] The present invention relates to additives for cementitious extrusion molding.

[Prior Art] A particular problem when extruding a water-kneaded product containing cement as a main component, for example, a water-kneaded product of asbestos and cement, is that the extrusion pressure applied to the die causes poor water retention of the water-kneaded product. Water separates and only water comes out from the die outlet, causing solid matter to clog the extruder, resulting in a dehydration phenomenon.

Conventionally, hydro-transforming agents such as cellulose derivatives, polyvinyl alcohol, polyethylene oxide, and polyacrylamide have been known to prevent this dehydration phenomenon (
For example, Japanese Patent Publication No. 43-7134).

[Problems to be solved by the invention] However, even if the above-mentioned hydro-transforming agent is used, dehydration of the water-kneaded product mainly composed of cement may occur during the extrusion molding process, or the torque of the screw of the extruder may be reduced. There was a problem with the size.

[Means for Solving the Invention] The present inventors have arrived at the present invention as a result of extensive studies aimed at obtaining an extrusion molding additive that does not cause dehydration and has low torque.

That is, the present invention provides polyethylene oxide (A) and (
alkyl) consisting of a salt of a naphthalene sulfonic acid formalin condensate and/or a salt of a melamine sulfonic acid formalin condensate (B), and the amount of (A) is 90 to 90% based on the total weight of (A) and (8). 50%, the amount of (B) is 10
This is an additive for cement-based extrusion molding characterized by a content of ~50%.

In the present invention, the (alkyl)naphthalene sulfonic acid-based formalin condensate salt is obtained by highly formalin condensing naphthalene sulfonic acid and/or alkylnaphthalene sulfonic acid, and the remaining amount of unreacted naphthalene sulfonic acid is, for example, 8% by weight. For example, products obtained by neutralizing formalin condensed with caustic soda, calcium hydroxide, etc. until
No. 1737, Japanese Patent Publication No. 48-9564, Japanese Patent Publication No. 58-6
No. 2153, Japanese Unexamined Patent Publication No. 58-74713, etc.).

Examples of (alkyl) naphthalene sulfonic acid (referring to naphthalene sulfonic acid and/or alkylnaphthalene sulfonic acid; the same description will be used hereinafter) include naphthalene sulfonic acid, alkylnaphthalene sulfonic acid having an alkyl group having 1 to 18 carbon atoms, such as methylnaphthalene. Examples include sulfonic acid, ethylnaphthalene sulfonic acid, and butylnaphthalene sulfonic acid. Among these, naphthalene sulfonic acid is preferred.

Naphthalenesulfonic acids include α-naphthalenesulfonic acid and β-naphthalenesulfonic acid, and β-naphthalenesulfonic acid is preferred.

(Alkyl) Naphthalene sulfonic acid-based formalin condensate salts include alkali metal salts (sodium salts, lithium salts, potassium salts, etc.), divalent metal salts (calcium salts, magnesium salts, zinc salts).

iron salts, etc.), trivalent metal salts (aluminum salts, iron salts, etc.), ammonium salts, amine salts [lower alkylamine salts (methylamine salts, etc.), alkanolamine salts (tri,
di- or monoethanolamine salts, etc.) and salts of two or more of these. Among these, preferred are alkali metal salts and ammonium salts, and particularly preferred are alkali metal salts.

The salt of the (alkyl)naphthalene sulfonic acid-based formalin condensate may be a salt of the formalin cocondensate of (alkyl) naphthalene sulfonic acid and other aromatic compounds and/or this sulfonic acid, as long as it does not impair performance. You can.

Other aromatic compounds and their sulfonic acids include aromatic compounds (naphthalene, anthracene, etc.), aromatic sulfones M (benzenesulfonic acid, etc.).

anthracenesulfonic acid, etc.), alkyl-substituted aromatic sulfonic acids (such as toluenesulfonic acid, dodecylbenzenesulfonic acid), alkoxy-substituted benzenesulfonic acids (such as methoxybenzenesulfonic acid), hydroxy-substituted benzenesulfonic acids (such as phenolsulfonic acid), alkoxy-substituted benzenesulfonic acids (such as phenolsulfonic acid), and hydroxy-substituted benzenesulfonic acids (such as cresolsulfonic acid), alkyl- and alkoxy-substituted benzenesulfonic acids (such as ligninsulfonic acid), and the like.

As the salts of these formalin cocondensates, the same salts as the above (alkyl) naphthalene sulfonic acid formalin condensates are used, and among these, alkali metal salts and ammonium salts are particularly preferred. is an alkali metal salt.

Examples of the salts of melamine sulfonic acid formalin condensates include salts of melamine sulfonic acid formalin condensates.

Salt of melamine sulfonic acid formalin condensate.

Generally, melamine, formaldehyde or paraformaldehyde, and sulfites (sodium sulfite, ammonium sulfite, sodium bisulfite, ammonium bisulfite, etc.) are subjected to an addition reaction in water under alkaline conditions (for example, about 119-12).

Addition reaction under alkaline conditions is condensed under weak acidity (e.g. pH 4 to 6), and addition reaction under alkaline conditions is condensed under strong acidity (for example, pH 4 to 6).
Examples include those highly condensed with DH2-4). Among these, preferred are those obtained by addition reaction under alkaline conditions and highly condensed under strongly acidic conditions. Examples of this salt include salts of (alkyl)naphthalene sulfonic acid formalin condensates similar to those listed above.

Salts of melamine sulfonic acid formalin condensates are commercially available, such as Melmento manufactured by Showa Denko ■ and Kiba-4000 and NP-20 manufactured by Hozoris Bussan.

Among the salts of (alkyl) naphthalene sulfonic acid formalin condensates and the salts of melamine sulfonic acid formalin condensates, salts of (alkyl) naphthalene sulfonic acid formalin condensates are preferred.

As polyethylene oxide (A), one having an average molecular weight of 2 million to 5 million is usually used.

Preferably, the average molecule i is 4 million to 5 million. If the average molecular weight is less than 2,000,000, the water-retaining property of the water-kneaded product is poor and dehydration occurs.

Furthermore, water-soluble or water-dispersible ether cellulose such as methylcellulose, hydroxypropylmethylcellulose, hydroxyethylmethylcellulose, ethylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, etc. can be used in combination with polyethylene oxide, if necessary.

The content of polyethylene oxide and water-soluble ether cellulose is based on the total weight of polyethylene oxide and water-soluble ether cellulose. It is 99%.

The content of (A) and (B) is usually 90-50%, preferably 8%, based on the total weight of (A) and (B).
0-60%, the amount of (B) is usually 10-50%, preferably.

It is 20-40%.

If the contents of (A) and (B) are outside the above range, torque may increase or dehydration may occur.

Cement materials for which the additive of the present invention is used include:
Hydraulic cements include, for example, ordinary Portland cement, blast furnace cement, fly ash cement and colored cement.

It is also possible to add fibrous materials for reinforcement, such as inorganic fibers (asbestos, rock wool, glass fibers, etc.) and organic fibers (polyamide fibers, polyester fibers, polypropylene fibers, etc.). Further, aggregates such as river sand, silica sand, lightweight aggregates, borazone, etc. may be used.

The blending ratio of the additive of the present invention to the cement material is as follows:
Cement-based materials, 1! Mixing ratio of fibrous materials, aggregates, etc.
Although it can be changed in various ways depending on the extrusion speed of the molded product, the shape of the die, etc., the total weight of (A) and (8) for 100 parts of cement material (parts refer to parts by weight, hereinafter the same) is usually 0. .1 to 5 parts, preferably 0.2 to 2 parts.

In addition, for 100 parts of cement material, the amount of fibrous material is usually 20 to 50 parts, preferably 2 to 40 parts, the amount of aggregate is usually 0 to 50 parts, preferably 0 to 40 parts, and the amount of water. is usually 20 to 80 parts, preferably 20 to 70 parts.

Cement material, fibrous material, aggregate 1 The blending ratio of the additive of the present invention to the water kneaded material containing the additive of the present invention and water is the blending ratio of the cement material, fibrous material, aggregate, etc. Shape quantity extrusion speed.

It can be changed in various ways depending on the shape of the die, etc.

The ratio of the additive of the present invention to the water kneaded product is usually 0.03~
4 parts, preferably 0.07 to 1.7 parts.

Examples of how to use the additive of the present invention are as follows. That is, a cement material, a fibrous material, an aggregate, and the additive of the present invention are tri-blended using a kneader-type mixer or the like, water is added thereto, and the mixture is processed using a screw-type vacuum extrusion molding machine.
The water kneaded material is extruded into the desired shape through a screw type extruder, plunger type extruder, etc., and a die attached to the tip of the extruder.

The extruded product is cut into desired lengths using a cutting machine or the like, and then cured at room temperature with steam or autoclave to form a product.

[Examples] The present invention will be further explained below with reference to Examples, but the present invention is not limited to these Examples.

Examples 1-4. Comparative Examples 1-5 Table 1 shows the additives of the present invention (Examples 1-4) and comparative additives (Comparative Examples 1-5).

Table 1 (Note 1) PEO: Polyethylene oxide with a 1% by weight aqueous solution viscosity of 1900cp HPMC: 2% by weight hydroxypropyl methyl cellulose with an aqueous solution viscosity of 8300cd NSF: Naphthalene sulfonic acid formalin condensate sodium salt with average degree of condensation ~13 PVA: Polyvinyl alcohol, 2% by weight aqueous solution, viscosity 15CI) The following tests were conducted using the additives shown in Table 1.

(Test) After tri-blending 100 parts of Portland cement, 20 parts of asbestos, and 1 part of additives, 35 parts of water was added and mixed in a mortar mixer for 5 minutes to create a hot kneaded mixture. Extrusion molding was carried out through a screw-type extrusion molding machine with a 10 mm diameter die attached to its tip, and the torque applied to the screw shaft was measured, the presence or absence of dehydration phenomenon was observed, and the surface of the extruded product was observed. Ta.

The test results are shown in Table-2.

Table-2 (Note 2) Good: The surface of the extruded product is smooth.

Defective: The surface of the extruded product is scaly or crack.

Additives with good performance are those that have a small torque applied to the screw shaft, do not cause dehydration from the die outlet, and give extruded products a smooth appearance.

From the test results shown in Table 2, the additive of the present invention lowered the torque of the screw of the extruder, the surface of the extruded product was smooth, and no dehydration phenomenon was observed.

[Effects of the Invention] The additive of the present invention, as an additive for cement extrusion molding, is characterized by superior performance in the following items compared to conventional additives.

(1) The torque applied to the extruder is reduced.

By using the additive of the present invention, the water-kneaded product becomes more slippery within the die and has less stickiness, so that the torque applied to the extrusion molding machine becomes lower.

(2) Dehydration phenomenon inside the extrusion molding machine is eliminated.

By using the additive of the present invention, the water-kneaded product has good water retention and eliminates the dehydration phenomenon in the extrusion molding machine.

(3) The surface of the extrusion molded product becomes good.

By using the additive of the present invention, the water-kneaded product has good water retention and adhesion, and the surface of the extruded product becomes good.

(4) The production amount of extrusion molded products per unit time can be increased. - By using the additive of the present invention, the torque applied to the extrusion molding machine is reduced, making it possible to increase the extrusion speed of the extrusion molded product and increasing the production amount of the extrusion molded product per unit time. can.

Because of the above effects, extrusion molded products using the additive of the present invention are useful for external wall materials, ceiling materials, etc. of buildings.

Claims (1)

[Claims] 1. Consisting of polyethylene oxide (A) and (alkyl)naphthalene sulfonic acid formalin condensate salt and/or melamine sulfonic acid formalin condensate salt (B) and based on the total weight of (A) and (B) An additive for cement extrusion molding, characterized in that the amount of (A) is 90 to 50% and the amount of (B) is 10 to 50%.