JPH10205054A - Hard cemented chip board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hard cemented chip board, which has a short hardening time and excellent high-early strength and in which breaking and collapse are difficult to be generated in a butt end section. SOLUTION: The hard cemented chip board 1 is obtained by heating and pressing a material, in which fractionated chips and water are mixed with a cement composition consisting of Portland cement, alumina cement, anhydrous gypsum or hemihydrate gyprum and the alkaline metallic salts of an organic carboxylic acid. The chamfering of C 0.5-5.0 is executed to at least one of both side edges of all butt end sections 11 at that time.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hard wood cement board mainly used as a building material.

[0002]

2. Description of the Related Art Conventionally, a wood cement molded article, which is a composite molded article of a wood material such as a wool cement board, a wood chip cement board, and a cement, is mainly used as a building material. In the case of using cements mainly composed of inexpensive Portland cement as a main component, it takes a long time to cure, and various measures such as addition of a curing accelerator have been made. Nevertheless, it takes at least one day and night from molding to demolding, which is a cause of high costs.

[0003] In view of this point, as a cement, a heat-curable cement composition comprising a component selected from Portland cement, alumina cement, anhydrous gypsum or hemihydrate gypsum, and lime is used. There is known a method in which flaked wood material and water are mixed, the mixture is formed into a predetermined shape, and the mixture is heated and cured (for example, Japanese Patent Publication No. 59-18339).

[0004]

However, the wood cement molded product obtained by such a conventional method is as follows.
At the time of handling during transportation and construction, it is easy for chipping or collapsing due to bumping or rubbing to occur at the wooden mouth that plays an important role in connection with other members, which may hinder construction. There is a problem that there is.

SUMMARY OF THE INVENTION An object of the present invention is to provide a hard wood chip cement board which solves the above-mentioned conventional problems, has a short curing time, has excellent early strength, and is hardly chipped or collapsed at a wood opening. It was done as.

[0006]

The present invention according to claim 1 (the present invention 1) provides a cement composition comprising Portland cement, alumina cement, gypsum anhydrite or hemihydrate gypsum, and an alkali metal salt of an organic carboxylic acid. A hard wood chip cement board obtained by hot-pressing a mixture obtained by mixing finely divided wood chips and water, wherein at least one side edge of both side edges of all wood ends has C0.5. ~
It is a hard wood cement board with a 5.0 chamfer.

The present invention according to claim 2 (invention 2) provides a cement composition comprising Portland cement, alumina cement, anhydrite or hemihydrate gypsum, an alkali metal salt of an organic carboxylic acid, and a piece of wood fragmented into a cement composition. A coating layer having a strengthening function is provided on all the lips of the hard wood chip cement board substrate obtained by hot pressing the mixture obtained by mixing the water, and a coating layer having a waterproof function is provided thereon. Hard wood chip cement board.

The present invention according to claim 3 (invention 3) is characterized in that the cement composition comprises 50 to 96 parts by weight of Portland cement, 2.0 to 25 parts by weight of alumina cement, and 0 to 25 parts by weight of slaked lime.
The present invention 1 which is obtained by mixing 0.2 to 2.0 parts by weight of an alkali metal salt of an organic carboxylic acid with 100 parts by weight of a mixture consisting of 10 parts by weight, 1.5 to 15 parts by weight of anhydrous gypsum or gypsum hemihydrate. Or a hard wood chip cement board according to the second aspect of the present invention.

In the present invention, as the fragmented wood pieces, for example, cedar, cypress, pine, toga, straw, birch, beech, oak, lauan, hiba, chestnut, keyaki, shii, willow, bamboo, etc. A piece of wood made of wood chips made from a material is used. The wood piece may be only a wood piece made of wood chips made from new wood, or may contain a wood piece made of wood chips made from construction waste.

[0010] As a method for producing a wood chip, a known method can be used, and examples thereof include a method of pressing with a press or a rotating roll, and a method of cutting with a slitter or a cutting machine. The size, length, and shape of the wood chip pieces can be arbitrarily determined according to the application, strength, and the like.

In the present invention, a cement composition comprising portland cement, alumina cement, anhydrite or hemihydrate gypsum, and an alkali metal salt of an organic carboxylic acid is used. Lime may be contained in the cement composition. In addition, hemihydrate gypsum may be used together with anhydrous gypsum.

As the Portland cement, for example,
Ordinary Portland cement, early-strength Portland cement, ultra-high-strength Portland cement, white Portland cement and the like are used.

As the alkali metal salts of organic carboxylic acids, for example, organic carboxylic acids include citric acid, malic acid,
Gluconic acid, glutaric acid, glycolic acid and the like, and alkali metal salts such as sodium salt and potassium salt are used.

In the present invention, the cement composition comprises 50 to 96 (80 to 96) parts by weight of Portland cement, 2.0 to 25 (2.0 to 10) parts by weight of alumina cement,
100 parts by weight of a mixture consisting of 0 to 10 (0 to 5) parts by weight of slaked lime, 1.5 to 15 (1.5 to 5) parts by weight of anhydrous gypsum or (and) hemihydrate gypsum, and an alkali metal salt of an organic carboxylic acid A mixture of 0.2 to 2.0 parts by weight is preferable (a more preferable range is in parentheses).

If the amount of Portland cement component is too small, not only is it economically disadvantageous, but also the durability after curing, such as drying shrinkage at 50 ° C. or higher, tends to increase.
If it is too large, early strength tends to be insufficient. When the amount of the alkali metal salt component of the organic carboxylic acid is within the above range, the pot life of the cement paste is extended, and the strength immediately after heat-curing is improved, so that early demolding can be performed without any trouble.

In the present invention, the mixing ratio of the finely divided wood pieces and the cement composition is preferably 5 to 30% by weight of the wood pieces and 70 to 95% by weight of the cement composition. Less than 5% by weight of wood chips and 95% by weight of cement composition
When the amount exceeds 70%, the advantage of mixing wood chips is reduced and the raw material cost is increased. When the cement composition is less than 70% by weight and the amount of wood particles is more than 30% by weight, it is difficult to increase the product strength.

In the present invention, the wood opening means the side surface and the end surface of the hard wood chip cement board. In the present invention 1,
At least one of the two side edges of all the lip portions is chamfered, i.e., all the lip portions of the hard wood chip cement board, that is, of all the side edges of the side and end surfaces. At least one side edge must be chamfered.

The degree of chamfering is C0.5-5.
Must be in the range of 0. Here, C is a unit of chamfering, and the length (mm) of the chamfered portion in the direction of the cut edge portion of the portion to be chamfered by 45 ° cut, and the direction perpendicular to the cut edge portion surface, that is, The length (mm) in the front or back direction of a hard wood chip cement board, for example, C
1.0, as shown in FIG. 1, the length of the chamfered portion in the direction of the apex surface a of the chamfered portion, as shown in FIG. Both the lengths in the direction of the surface b of the cement board are 1.0 mm.

If C is less than 0.5, it is difficult to work, and in addition, during handling during transportation or construction, the part is bumped or rubbed against other members, causing chipping or collapse. Conversely, if C exceeds 5.0, it is not possible to secure the thickness of the chamfered portion and the edge of the lip, and in an extreme case, a ridge line near a right angle is formed on the edge of the lip, so that At the time of handling at the time of transportation or construction, the part is bumped or rubbed against another member, so that chipping or breaking easily occurs.

In the present invention 2, as a coating liquid for forming a film material layer having a strengthening function, for example, a so-called impregnated sealer such as an epoxy emulsion or an acrylic emulsion, or an epoxy adhesive is cured to form a film. And those that solidify.

As a coating liquid for forming a coating layer having a waterproof function, any liquid-repellent coating liquid can be suitably used. For example, paraffin, rubber, polyvinyl chloride or the like is dissolved in a solvent. Or an emulsion.

[0022]

The hard wood chip cement board of the present invention is obtained by mixing a finely divided wood chip and water with a cement composition comprising Portland cement, alumina cement, anhydrous gypsum or hemihydrate gypsum, and an alkali metal salt of an organic carboxylic acid. Since the mixture is obtained by hot pressing, the curing time is short, the early strength is excellent, and at least one side edge of both side edges of all the wood ends has C.
Since the chamfer of 0.5 to 5.0 is provided, the edge of the chamfered edge of the opening does not have a corner, so that it may be bumped or rubbed during transportation or handling during construction. Even if it does, chipping, collapse and the like are unlikely to occur.

The hard wood chip cement board of the present invention 2 is obtained by subdividing the hard wood chip cement board substrate into a cement composition comprising Portland cement, alumina cement, anhydrous gypsum or hemihydrate gypsum, and an alkali metal salt of an organic carboxylic acid. A mixture obtained by hot pressing a mixture of wood chips and water has a short curing time, is excellent in early strength, and has a coating function having a strengthening function on all wood ends of a hard wood chip cement board substrate. The membrane layer is provided, and by providing the coating layer having a waterproof function thereon, the kiguchi portion is reinforced by the coating layer having the reinforcing function, and the coating layer having the waterproof function is provided by the coating layer having the waterproof function. Since moisture does not penetrate, chipping or collapse is unlikely to occur even if bumped or rubbed during handling during transportation or construction.

The hard wood chip cement board according to the third aspect of the present invention is the cement board according to the first or second aspect, wherein the cement composition comprises 50 to 96 parts by weight of portland cement, 2 parts by weight of alumina cement.
0 to 25 parts by weight, 0 to 10 parts by weight of slaked lime, 100 to 100 parts by weight of a mixture consisting of anhydrous gypsum or 1.5 to 15 parts by weight of gypsum, 0.2 to 2.0 parts of an alkali metal salt of an organic carboxylic acid
By mixing the parts by weight, the curing time is short, the early strength is excellent, the pot life of the mixture (cement paste) is extended, and the strength immediately after heat curing is further improved. Early demolding can be performed without using.

[0025]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 2 is a sectional view showing an example of the hard wood chip cement board of the present invention. Hard wood chip cement board 1
Is obtained by hot-pressing a mixture of Portland cement, alumina cement, anhydrous gypsum or hemihydrate gypsum, and a cement composition comprising an alkali metal salt of an organic carboxylic acid, mixed with finely divided wood chips and water. It is. Chamfers 11a, 11 of C0.5-5.0 are provided on the side edges on the front side of the cut ends 11, 11 of the hard wood chip cement board 1.
a is given.

FIG. 3 is a sectional view showing another example of the hard wood chip cement board of the present invention. The hard wood chip cement board 2 is obtained by hot pressing the same mixture as described with reference to FIG. On both side edges of the wood ends 21, 21 of the hard wood chip cement board 2, C0.
5 to 5.0 chamfers 21a, 21a, 21a, 21a are provided.

FIG. 4 is a plan view showing another example of the hard wood cement board of the present invention. The hard wood chip cement board 3 is made of all the wood ends 31 of the base material 31 obtained by hot pressing the same mixture as described with reference to FIG.
1, 311, 311 and 311 are provided with a coating layer 32 having a reinforcing function, on which a coating layer 33 having a waterproof function is provided.
Is provided.

[0028]

EXAMPLE 1 Mixture 1 of early strength Portland cement: alumina cement: slaked lime: calcined gypsum = 80: 10: 4: 6 (weight ratio)
0.2 parts by weight of sodium citrate was mixed with 00 parts by weight to prepare a cement composition. To 100 parts by weight of the obtained cement composition, 35 parts by weight of flaked wood pieces and 60 parts by weight of water were mixed to prepare a cement slurry.

[0029] The obtained cement slurry is vertically
The product was heated and pressed at 30 kgf / cm ² for 15 minutes on a heating board at 97 ° C., and then removed from the mold. The length was 2710 mm × width 910.
A hard wood chip cement board substrate A having a size of 15 mm × 15 mm was obtained. The hard wood chip as shown in FIG. 3 is subjected to C1.0 chamfering as shown in FIG. Cement board 2 was obtained.

Example 2 A hard wood chip cement plate 2 as shown in FIG. 3 was prepared in the same manner as in Example 1 except that pressure molding was performed using a heating plate having a molding portion corresponding to chamfering. I got

Example 3 An epoxy-based emulsion was applied to all the openings of the hard wood chip board A obtained in Example 1 and then dried to form a coating layer 32 having a reinforcing function. A styrene-butadiene rubber-based emulsion was applied thereto, followed by drying and application of a coating having a waterproof function to obtain a hard wood chip cement plate 3 as shown in FIG.

The outer wall was constructed using 100 pieces of each of the evaluation examples 1 to 3 and the hard wood chip cement board substrate A. At that time, chipping or breaking of the wood opening caused troubles in the construction. Was evaluated. As a result, in the case of Examples 1 to 3,
While there was no chipping or collapse of the wood opening that would hinder construction, in the case of the hard wood chip cement board substrate A, five chips of the wood opening that hindered construction occurred.

[0033]

As described above, the hardened wood chip cement board of the present invention 1 has a short hardening time, is excellent in early strength, and can be used for handling at the time of transportation or construction. Even if the chamfered portion is bumped or rubbed, chipping or collapse is unlikely to occur and does not hinder construction.

Since the hardened wood chip cement board of the present invention 2 is constructed as described above, it has a short hardening time, is excellent in early strength, and has two layers at the wood opening at the time of handling during transportation and construction. Even if the portion provided with the coating film layer is hit or rubbed, chipping or collapsing hardly occurs, and there is no trouble in construction.

[0035] The hardened wood chip cement board of the third aspect of the present invention is constructed as described above, so that the hardening time is short, the early strength is excellent, and the pot life of the mixture (cement paste) is extended. Further, the strength immediately after the heat curing is further improved, and the early demolding can be performed without using.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a chamfering unit C according to the present invention.

FIG. 2 is a sectional view showing an example of a hard wood chip cement board of the present invention.

FIG. 3 is a cross-sectional view showing another example of the hard wood chip cement board of the present invention.

FIG. 4 is a plan view showing still another example of the hard wood chip cement board of the present invention.

[Explanation of symbols]

 1,2,3 Hard wood chip cement board 11,21,311 Kiguchi 11a, 21a Chamfering 32 Coating layer with reinforcing function 33 Coating layer with waterproofing function

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI C04B 7:32 22:06 22:14 24:04 18:26)

Claims (3)

[Claims] 1. A hot-pressed mixture of portland cement, alumina cement, anhydrite or hemihydrate gypsum, and a cement composition comprising an alkali metal salt of an organic carboxylic acid, mixed with finely divided wood chips and water. A hard wood chip cement board, wherein at least one side edge of both side edges of all of the wood mouths, C0.5 ~
A hard wood chip cement board characterized by a chamfer of 5.0. 2. A mixture obtained by mixing a fragment of wood and water with a cement composition comprising Portland cement, alumina cement, anhydrous gypsum or hemihydrate gypsum, and an alkali metal salt of an organic carboxylic acid. A hard wood chip cement board comprising: a hard wood chip cement board; and a coating layer having a reinforcing function provided on all of the wood ends of the obtained hard wood chip cement board substrate, and a coating layer having a waterproof function provided thereon. 3. The cement composition comprises 50 to 96 parts by weight of Portland cement, 2.0 to 25 parts by weight of alumina cement, 0 to 10 parts by weight of slaked lime, 1.5 to 15 parts by weight of gypsum anhydrite or hemihydrate gypsum. The hard wood chip cement board according to claim 1 or 2, wherein 0.2 to 2.0 parts by weight of an alkali metal salt of an organic carboxylic acid is mixed with 100 parts by weight of the mixture.