JP2000128608A - Flame resistant cement formed product reinforced by modified pulp - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve lightness, flexibility and nailing properties by using a flame-resistant modified pulp having one or more kinds of compounds selected from a metal oxide, metal hydroxide and metal oxyhydroxide fixed thereto, as a reinforcing material. SOLUTION: The metal oxides have activities for accelerating carbonization of the pulp. The pulp are generally used without drying, and the many metal oxides having crystal water also can be used. When a halogen is used as a counter ion of the metal salt in the production of the metal oxides, the halogen is taken in the metal oxides by partial adsorption or the like, and the effect of the flame resistance is improved because the chain reaction in flaming is inhibited by the halogen. Especially, copper oxides having the formula CuCl2.3Cu(OH)2 are excellent in the effect, hardly dissolved even if washed with water, and stable in the cement. A linter pulp, a hemp pulp or the like can be used as the pulp.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a modified aggregate obtained by fixing a metal oxide, a metal hydroxide, or a metal oxyhydroxide to a lightweight aggregate to make it a flame-retardant pulp as a reinforcing material. The present invention relates to a flame-retardant cement molding by pulp reinforcement.

[0002]

2. Description of the Related Art Conventionally, pulp has been widely used as a reinforcing material for cement materials in a wide range of fields such as civil engineering and construction. Further, in recent years, as the harmfulness of asbestos has become apparent, it has been used as an alternative fiber such as asbestos in protecting and improving environmental hygiene. In particular, it is suitable for molding a material that can be nailed as a building material, and is also effective as a reinforcing material for a lightweight material. Therefore, in the molding of cement-based materials, when lightweight, enhanced flexibility, nailing is required,
It was effective to use pulp as a reinforcing material.

[0003] However, pulp has a drawback that it is easily burned, and in order to enhance the flame retardancy and fire resistance of cement-based materials, the amount of pulp blended has been reduced or the cement molded product has been made thicker. Therefore, when flammable pulp is used as a filler (reinforcing material) of a fixed-form cement-based material, the amount of pulp must be limited in order to maintain incombustibility. In such a background, Japanese Patent Application Laid-Open No. 3-146766 discloses a pulp fiber containing an insoluble and non-flammable inorganic substance having improved flame retardancy by reducing the calorific value.

[0004]

However, in the above case,
After infiltrating one of the cation-containing treatment liquid and the anion-containing treatment liquid to produce an insoluble incombustible inorganic substance,
The other must be immersed, which is complicated. Moreover, according to the embodiment of the disclosed technique, it is not practical because it takes a long time (one day) because it is immersed in each of the embedding liquids. The present invention has been made in view of the above circumstances, and obtained by fixing a metal compound to pulp, by using a non-combustible modified pulp as a reinforcing material, light weight, flexibility, excellent nailing properties. It is an object of the present invention to provide a flame-retardant cement molded product.

[0005]

In order to achieve the above object, a flame-retardant cement molding obtained by reinforcing a modified pulp according to claim 1 comprises a metal oxide, a metal hydroxide and a metal oxyhydroxide. It is characterized in that the flame-retardant modified pulp to which at least one metal compound is fixed is used as a reinforcing material.

According to a second aspect of the present invention, there is provided a flame-retardant cement molded product obtained by reinforcing a modified pulp, wherein the cement molded product is used for civil engineering and / or construction. It is characterized by being used.

The flame-retardant cement molded product obtained by reinforcing the modified pulp according to claim 3 is the flame-retardant cement molded product obtained by reinforcing the modified pulp according to claim 1 or 2, wherein the metal compound is a halide. It is characterized by having.

A flame-retardant cement molded product obtained by reinforcing a modified pulp according to claim 4 is the flame-retardant cement molded product obtained by reinforcing a modified pulp according to any one of claims 1 to 3, wherein the metal compound is It is characterized by being CuCl ₂ .3Cu (OH) ₂ .

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, an embodiment of a flame-retardant cement molded product by reinforcing a modified pulp of the present invention will be described. A technique for fixing a metal compound to pulp has already been disclosed in JP-A-5-8
Although it is disclosed in Japanese Patent No. 01143, the fact that pulp to which these metal compounds are fixed has flame retardancy has been clarified.

[0010] The present invention relates to a flame-retardant cement molding utilizing the above characteristics. That is, dissolve the metal salt,
The particle size of metal oxides precipitated in a colloidal state in a floating state by controlling the heating, pH adjustment, etc. and hydrolyzing is a treatment liquid when penetrating into pulp generally used for civil engineering and construction. Is smaller than the narrowest gap in the path to be passed, and is considered to penetrate between the pulp. By using colloidal metal oxides, they are fixed to pulp in a short time. Materials for civil engineering and construction using this modified pulp
It was confirmed that the flame retardancy was improved, and the present invention was completed.

Hereinafter, the present invention will be described in detail. First, the mechanism for improving the flame retardancy will be described. There are several possible mechanisms for improving flame retardancy. The metal oxides promote the carbonization of the pulp. The formed carbonized layer works with the heat insulating layer to produce a flame retardant effect. Decomposition of metal oxides,
Endothermic due to release of water of crystallization is also conceivable. It is also conceivable to inhibit the chain reaction and generate nonflammable gas in the flame combustion of halogen. Organic fibers are also combustibles used for civil engineering materials, but pulp generates more heat than organic fibers. Therefore, making pulp flame-retardant is extremely effective.

Next, the manufacturing method will be described. Pulp to which metal oxides are fixed is a step of mixing at least one metal salt and a solvent, a step of immersing the pulp in the mixture obtained in the above step, and the addition of energy to the mixture and Alternatively, it can be produced by combining the pH adjustment step and the dehydration step.

The metal oxides fixed in the present invention are Fe
A mixture containing one or more metal oxides, metal oxyhydroxides, metal hydroxides and the like, such as ₂ O ₃ , FeOOH, and Fe (OH) ₃ . Further, two or more metal oxides may be fixed. Although there is no particular limitation on the particle size, the particle size is generally 1 nm to 1000 nm depending on the type of metal.

The metal species of the metal oxides used to enhance the flame retardancy may be any metal species that adheres to the pulp by the present production method. For example, iron, copper, manganese, molybdenum, silicon, titanium, vanadium, chromium, cobalt, nickel, aluminum, zinc and the like can be mentioned. The valence of the metal species may be any. It is preferable to select metal oxides having a large effect of the above-described mechanism of improving the flame retardancy.

The metal oxides mentioned here have the effect of accelerating the carbonization of the pulp. In general, pulp is often used without drying, and most of the metal oxides easily have water of crystallization. When halogen is used as the counter ion of the metal salt used in the production of metal oxides, it is partially absorbed into the metal oxides and taken in, thereby inhibiting the chain reaction in the flaming combustion of the halogen and causing flame retardancy. Enhance the effect of

In particular, when CuCl ₂ · 2H ₂ O is used as a raw material, a colloidal CuCl ₂ · 3C at pH <4.5 is used.
Copper oxides having the structural formula of u (OH) ₂ are obtained. It inhibits the chain reaction in flaming combustion of halogen and enhances the effect of flame retardancy. CuCl ₂ .3Cu (OH) ₂ does not dissolve even when washed with water, and is stable in cement and is suitable. In addition, the pulp to CuCl ₂ · 3Cu (OH) ₂
An antimicrobial function can be imparted by fixing the particles.

The pulp of the present invention is thoroughly washed with a suitable method. Thereafter, it is appropriately dehydrated and used. The pulp that can be used in the present invention may be wood pulp, linder pulp, or hemp pulp that has been bleached or unbleached. The metal oxides may be fixed to the pulp beaten to a predetermined beating degree, or may be beaten to a predetermined beating degree after fixing the metal oxides.

The time of immersion in the solution containing metal oxides varies depending on the degree of beating of the pulp. The fixation starts instantaneously and the amount of fixation reaches saturation when it is fixed on the entire pulp surface. If it is cottony, it will reach saturation if immersed for 10 minutes.

Next, a method for producing a civil engineering building material as a flame-retardant cement molded product using the pulp of the present invention will be described. The pulp in which the metal oxides of the present invention are fixed to a cement, a filler, or an aggregate can be formed into a civil engineering building material. Pulp to which metal oxides are fixed and pulp to which metal oxides are not fixed may be mixed and used. Usually, about 2% to 10% is added.

Various fibers can be added for the purpose of reinforcing other strengths such as bending strength and impact performance. When organic fibers such as polyolefin, polyvinyl alcohol, and acrylic are used, they are usually added in an amount of about 0.1% to 3%. These fibers generate less heat than pulp, but are flammable fibers, so it is possible to increase the amount of pulp and organic fibers added by using those fibers that have metal oxides fixed. And a material for civil engineering and construction, which is a flame-retardant cement molded product having excellent fire protection properties and reinforcement properties.

Usually, Portland cement is used as the cement. Any of simple boltland cement such as early-strength portland cement and moderate portland cement, mixed portland cement, and special cement such as alumina cement and magnesia cement can be used. Silica sand, silica stone powder, and the like can be used as fillers and aggregates. This flame-retardant cement molded material for civil engineering and construction is manufactured by a premix method, an extrusion method,
It can be produced by any method such as a papermaking method.

The material for civil engineering and construction thus formed is:
Since pulp with a small calorific value is used, even if this pulp is added in a larger amount than usual in order to enhance the reinforcing effect, the fire protection performance of the material for civil engineering and construction is not reduced. Therefore, it is possible to produce a material for civil engineering and building having excellent fire prevention properties and reinforcement properties.

[0023]

The present invention will be described below with reference to examples. (Example 1) As pulp, cello fiber (highly beaten pulp) manufactured by Hyogo Pulp Industry was used. 10 g /
1000 l of 1-FeCl ₃ aqueous solution was prepared and heated to 70 ° C. With caustic soda, pH 1.
Adjusted to 8. The pulp was packed in a net-like bag, immersed in the liquid containing the iron oxides for 10 minutes, and maintained at 70 ° C. After the liquid was removed by centrifugation, it was sufficiently washed with water until the washing water became transparent, followed by centrifugal dehydration. The pulp was colored reddish. It was confirmed by an electron microscope that a needle crystal of about 15 nm was fixed.

Example 2 As pulp, cello fiber (highly beaten pulp) manufactured by Hyogo Pulp Industry Co., Ltd. was used. An aqueous solution of lg / l-CuCl ₂ was prepared in the reaction vessel and heated to 70 ° C. While sufficiently stirring, add ammonia water dropwise and p
Adjusted to H3.5. The pulp was packed in a net-like bag, immersed in the liquid containing the copper oxides for 10 minutes, and maintained at 70 ° C. After the liquid was removed by centrifugation, it was sufficiently washed with water until the washing water became transparent, followed by centrifugal dehydration. The pulp was colored light blue. It was confirmed by an electron microscope that needle crystals of about 25 nm were fixed.

Comparative Example As pulp, cello fiber (highly beaten pulp) manufactured by Hyogo Pulp Industry Co., Ltd. was used. The pulp was packed in a net-like bag, washed well with water and centrifugally dehydrated as in the examples. Using the pulp of Examples 1 and 2 and Comparative Example, an inorganic board as a cement molded product was manufactured by the following formulation and manufacturing method.

(Formulation 1) Ordinary Portland cement 99
To 1 part of polypropylene fiber (2d * 6 mm), the above pulp was added in an internal proportion as shown in Table 1 below to prepare a cement slurry having a slurry concentration of 8%. Next, this slurry was formed by a Hatschek machine. (Formulation 2) 99 parts of ordinary Portland cement and 1 part of polypropylene fiber (2d * 6m, Showa Denko masky) to which metal oxides were fixed were added with the above pulp in an inner ratio as shown in Table 1 below, and the slurry was added. A cement slurry having a concentration of 8% was prepared.

Next, the slurry was formed into a paper using a Hachiek machine. (Formulation 3) 50 parts of ordinary Portland cement, silica sand 49
To 1 part of polypropylene fiber (2d * 6 mm), the above pulp was added in an internal proportion as shown in Table 1 below to prepare a cement slurry having a slurry concentration of 10%.

Next, this slurry was formed into one layer by a flow-on method and pressed. The evaluation was made based on the temperature rise in the substrate test of JlsA 1321. (If the temperature is 50 ° C. or less, the bending strength was evaluated according to JLSA1408.) Table 1 shows the above results.

[0029]

[Table 1]

The pulp of Examples 1 and 2 has a greater flame-retardant effect than the pulp of Comparative Example, and the pulp of Example 2 is larger than the pulp of Comparative Example. The flexural strength did not differ between the pulp of Examples 1 and 2 and Comparative Example, and increased in proportion to the amount added. Although only a part of the examples can be explained in the examples, it is clear from JP-A-5-801143 that it is easy to fix metal oxides to pulp, and the metal oxides of the present invention were fixed. The effect of improving the flame retardancy of pulp
It is inferred from the mechanism that it is also a different formulation and a different manufacturing method.

[0031]

As described above, according to the flame-retardant cement molded product of the present invention using the modified pulp, the pulp having a small calorific value is used. It can be used as a cement molded product such as a material for use, and pulp can be easily modified, so that complicated work can be eliminated and furthermore, it can be manufactured in a short time. . That is, it is extremely effective in improving the flame retardancy of the cement molded product.

 ──────────────────────────────────────────────────続 き Continued on front page F-term (reference) 4G012 PA04 PA24 PA34 PB03 PB09 PC01 4L031 BA07 BA09 BA13 CA06 DA16 DA21

Claims (4)

[Claims] 1. A reforming method characterized in that a flame-retardant modified pulp to which at least one metal compound selected from a metal oxide, a metal hydroxide and a metal oxyhydroxide is fixed is used as a reinforcing material. Flame-retardant cement molding with pulp reinforcement. 2. The flame-retardant cement molded product as claimed in claim 1, wherein the cement molded product is used for civil engineering and / or construction. 3. The flame-retardant cement molded product as claimed in claim 1, wherein the metal compound is a halide. Wherein said metal compound is CuCl ₂ · 3Cu
The flame-retardant cement molded product according to any one of claims 1 to 3, which is (OH) ₂ .