JPH04209736A - Production of fiber-reinforced inorganic cured form - Google Patents

Abstract

PURPOSE:To obtain the title cured form excellent in mechanical strength, processability, etc., by disaggregating pulp of long fiber length and reinforcing fibers either long in fiber length or small in fiber diameter in a large quantity of water, followed by addition of a specified amount of a thickening agent and water, and then kneading with an inorganic hydraulic material followed by molding and curing. CONSTITUTION:First, pulp of long fiber length and reinforcing fibers (e.g. Vinylon fiber) either long in fiber length or small in fiber diameter are disaggregated in a large quantity of water to regulate the moisture content of both the pulp and fibers to >=75wt.%. The resulting product is then incorporated with (A)>=1 pt.wt. (based on 100 pts.wt. of said pulp)of a thickening agent (e.g. methyl cellulose) and (B) such an amount of water as to be no lower than the water content in said product but not more than that in the inorganic curable composition to be obtained. The resultant mixture is then mixed and kneaded with another material predominant in an inorganic hydraulic material (e.g. Portland cement). The kneaded product is then molded and cured, thus obtaining the objective cured form.

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to a method for manufacturing a fiber-reinforced inorganic cured body that can be used as a building material.

[Conventional technology]

Inorganic cured bodies in which pulp and reinforcing fibers are dispersed and reinforced with fibers are generally widely used as building materials and other products. Conventionally, this fiber-reinforced inorganic cured product is produced as a molding material by dry-mixing materials mainly consisting of an inorganic hydraulic substance, pulp, reinforcing fibers, and thickener, then adding water and further wet-mixing and kneading. An inorganic curable composition is obtained. Then, this inorganic curable composition is molded into a desired shape by an appropriate method such as extrusion molding or press molding, and the molded product is cured and cured to produce a product.

[Problem to be solved by the invention]

By the way, pulp dispersed in an inorganic curable composition in a conventional manufacturing process is generally dry-fibrillated using a device such as a hammer mill. this is,
This is because dry-fibrillated pulp is generally easy to disperse, but even when this pulp is used, it may contain some un-fibrillated material, or the defibrated pulp may become beaded and have a different composition. It may remain as lumps in things. In particular, in the extrusion molding method, inorganic hydraulic substances,
After dry mixing materials such as pulp, reinforcing fibers and thickener,
The composition is obtained by adding water to the mixture and further performing wet mixing and kneading. However, in the case of this method, since the mixing is done in a relatively small amount of water, long-fiber pulp with an average fiber length of 211ff1 or more or a fiber length of 5W is used.
It is difficult to unravel thin reinforcing fibers with a fiber diameter of 15 mm or less, and fiber balls are likely to form, which causes defects in the strength of the product and spoils the appearance. On the other hand, even if wet defibrated pulp is used, the pulp remains in small clumps when mixed using the mixing methods normally used to produce such compositions. This tendency is particularly noticeable when the fiber length of the pulp becomes long. In addition, a similar tendency can be seen with other reinforcing fibers, and there is a problem in that the thinner or longer the fibers become, the more difficult it becomes to disperse them, which worsens the surface properties of the product. Conventionally, both pulp and reinforcing fibers have been made using short fibers with good dispersibility, avoiding the mixing of long fibers, or adding long fibers in small amounts to the extent that they do not deteriorate the quality of the product. However, if the amount of long fibers added is small, the strength of the obtained inorganic cured product is slightly weak. Another object of the present invention is to provide a method for producing a fiber-reinforced inorganic cured product with good dispersion of relatively long or thin reinforcing fibers and excellent strength, workability, and surface smoothness.

[Means for Solving the Problem] In order to achieve such an object, the present inventors wet-fibrillated long-fiber pulp and reinforcing fibers with a long fiber length in a large amount of water, and When adjusted to a high level (e.g., 85% or higher) and mixed with other materials containing inorganic hydraulic substances as a main component, the long fibers first become monofilamentous in a large amount of water. . They have also found that by increasing the water content, they can be easily loosened even with a relatively low mixing force. However, it has been found that with this method, the amount of long fibers that can be mixed cannot be increased as much as expected because the water content is as high as, for example, 85% or more. On the other hand, when the moisture content is lowered, the pulp cannot be sufficiently dispersed and lumps occur. To try to solve this problem, increase the mixing speed,
We tried increasing the mixing time to increase the mixing force and forcibly disperse the pulp, but since the pulp would be damaged or broken by mixing, even if long-fiber pulp was used, the strength of the product would be reduced. I couldn't improve it. Therefore, the inventors conducted further intensive studies, and as a result, completed the present invention. That is, the present invention involves mixing and kneading a material containing an inorganic hydraulic substance, pulp, reinforcing fiber, and thickener with water to obtain an inorganic curable composition, and then shaping the inorganic curable composition into a desired shape. A method for producing a fiber-reinforced inorganic cured product, which is molded into a material and cured after curing, wherein pulp with a long fiber length and reinforcing fibers with a long fiber length or a small fiber diameter are disintegrated in a large amount of water to reach a water content of 75% or more. After adjusting the ratio, add 1 part by weight or more of a thickener to 100 parts by weight of pulp in this preparation, and add 1 part by weight or more of a thickener to 100 parts by weight of pulp in this preparation, and the water content of the inorganic curable composition to be obtained should not exceed the water content of this preparation. A fiber characterized in that an inorganic curable composition is obtained by adding and mixing a small amount of water to the preparation, and mixing and kneading this mixture with other materials containing an inorganic hydraulic substance as a main component. The gist of this article is a method for producing a reinforced inorganic cured body. [Function] Pulp with a long fiber length and reinforcing fibers with a long fiber length or a small fiber diameter are disintegrated in a large amount of water and dehydrated to adjust the moisture content to 75% or more, preferably 80% or more. Then, 1 part by weight or more (generally not more than 1 part by weight) of a thickener per 100 parts by weight of pulp in this preparation and the water content of the inorganic curable composition to be obtained by adding more than the water content of this preparation. By mixing this preparation in a viscous solution state with the addition of water in an amount not exceeding , it is possible to effectively apply shear to loosen and disperse the pulp and reinforcing fibers. In this way, the mixture in which the pulp and reinforcing fibers are sufficiently loosened and dispersed is mixed and kneaded with the inorganic hydraulic substance and other compounds, so the fiber length is 2 or more (- In general, long fiber pulp (20 aun or less) and fiber length of 5 mm or more or fiber diameter of 15-
This means that the reinforcing fibers below (generally 2p or more) can be completely dispersed and mixed in a relatively large amount. In addition, this method prevents the pulp and reinforcing fibers from scattering, which occurs when only water and the above-mentioned preparations are mixed using an Eirich mixer or super mixer, which are commonly used in extrusion molding or press molding. can do.

【Example】

The present invention will be explained in detail below with reference to examples thereof. The pulp is not particularly limited to softwood, hardwood, waste paper, synthetic pulp, etc., but softwood is preferred since it can be expected to have increased strength. Furthermore, whether or not this pulp is bleached or beaten is not particularly limited, and may be adjusted as appropriate without causing any problem. The reinforcing fibers are not particularly limited as long as they are fibrous and have a reinforcing effect, but examples include vinylon, polypropylene,
Examples include organic fibers such as acrylic, aramid, polyethylene, and nylon, and inorganic fibers such as carbon fiber, steel fiber, potassium titanate, and glass fiber. The thickener is not particularly limited, but methylcellulose, which is commonly used in extrusion molding, and the like can be used. If a thickener such as methyl cellulose is used, this thickener also acts as a molding aid during molding. If the thickener is less than 1 part by weight per 100 parts by weight of pulp, the thickening effect will be small and the dispersing effect will be small, and depending on the mixer, the pulp and reinforcing fibers may scatter. If the amount of water added to the pulp and reinforcing fibers exceeds the water content of the desired inorganic curable composition, it is difficult to dehydrate this mixture, so do not add more water to the hydraulic material than is necessary. This may result in mixing, making molding difficult, or
Alternatively, the strength of the obtained inorganic cured product becomes insufficient. The inorganic hydraulic substance is a substance that hardens by reacting with water, and includes, but is not particularly limited to, portland cement, slag cement, alumina cement, gypsum, and the like. In addition, other compounds may be added as needed during the overall mixing, such as inorganic lightweighting materials such as perlite, organic lightweight aggregates such as styrene beads, aggregates such as silica sand, fly ash, etc. Other fillers and the like are added as appropriate, but at the same time thickeners such as methyl cellulose, molding aids, other pulps, and reinforcing fibers may also be added. Although the inorganic curable composition obtained by mixing and cross-wiring is not particularly limited, it is usually molded into a desired shape by extrusion molding or press molding and cured by a known method to become an inorganic cured body. Note that the obtained inorganic cured product can be mainly used as a building material. (Example 1) NUKP (softwood unbleached kraft pulp) with a fiber length of 3M and vinylon fibers with a fiber length of 9 mm and a fiber diameter of 14 mm were disintegrated in a large amount of water and then dehydrated to produce a product containing 3 parts by weight of NUKP, A premix product (adjusted product) containing 2 parts by weight of vinylon fiber and a water content of 82% was obtained. Add 2 parts by weight of methyl cellulose as a thickener to this premix product and mix it with an Eirich mixer.
Mixed for 3 minutes on Orpm. The state of the mixture after this mixing was muddy and no lumps of pulp or vinylon fibers were observed. Next, 100 parts by weight of ordinary Portland cement and 50 parts by weight of fly ash were added to this mixture, and the mixture was thoroughly mixed again using an Eirich mixer at 50 rpm, and then kneaded using a mixer. This kneaded material was molded using a vacuum extrusion molding machine (screw diameter 100 mm).
φ) to obtain a molded body. This molded body was cured at 60° C. for 12 hours to obtain a fiber-reinforced inorganic cured body. (Example 2) A fiber-reinforced inorganic cured product was obtained in the same manner as in Example 1, except that 0.4 parts by weight of methylcellulose was added to the premix product and 1.6 parts by weight of methylcellulose was added during total mixing. Ta. (Example 3) A fiber-reinforced inorganic cured product was obtained in the same manner as in Example 1, except that 1 part by weight of vinylon fibers with a fiber length of 3 mm was also added during total mixing. (Example 4) A fiber-reinforced inorganic cured body was obtained in the same manner as in Example 1, except that 8 parts by weight of water was added to the mixture blended as shown in Table 1. Example 5) For the mixture blended as shown in Table 1, 3.
A fiber-reinforced inorganic cured body was obtained in the same manner as in Example 1, except that styrene beads in the weight part were added. (Example 6) A fiber-reinforced inorganic cured body was obtained in the same manner as in Example 1 except that polypropylene non-fibers with a fiber length of 12 mm were used as reinforcing fibers. (Comparative Example 1) 100 parts by weight of ordinary Portland cement, 50 parts by weight of fly ash, 28 parts by weight of water, 2 parts by weight of vinylon fiber,
3 parts by weight of wet defibrated NUKP and 2 parts by weight of methylcellulose were mixed and kneaded in the same manner as in Example 1 to obtain a fiber-reinforced inorganic cured body. (Comparative Example 2) A fiber-reinforced inorganic cured product was obtained in the same manner as in Example 1, except that methylcellulose was not added when the mixture was obtained, and 2 parts by weight of methylcellulose was added during overall mixing. (Comparative Example 3) Example 1 except that the moisture content of the premix product was 70%.
A fiber-reinforced inorganic cured body was obtained in the same manner as above. The fiber-reinforced inorganic cured products obtained in Examples 1 to 6 and Comparative Examples 1 to 3 were left for 3 weeks, and the bending strength after 3 weeks, the surface unevenness of the product, and the pulp mass appearing on the cut surface were evaluated. The results are shown in Table 1 along with the blending ratio of each composition. 19'/ As shown in Table 1, the fiber-reinforced inorganic cured bodies obtained in Examples 1 to 5 all had good surface conditions, good dispersion of pulp and reinforcing fibers, and strong strength. Ta. The size of the lump of pulp that appeared on the cut surface was about 3 InII+, and the shape was elliptical. On the other hand, in all of the fiber-reinforced inorganic cured bodies obtained in Comparative Examples 1 to 3, the pulp and reinforcing fibers were insufficiently dispersed, and there were many lumps of pulp with a size of about 3 to 20 mm, and the surface was uneven. was also severe, and was inferior to the examples in terms of strength.

【Effect of the invention】

Since the method for producing a fiber-reinforced inorganic cured product according to the present invention is configured as described above, the long fiber pulp effective in terms of strength and the reinforcing fibers having a relatively long fiber length or a small fiber diameter can be well dispersed. And the amount of filling can be secured sufficiently,
A fiber-reinforced inorganic cured product with excellent strength, workability, and product appearance can be obtained. Therefore, the inorganic cured product obtained by this manufacturing method can be effectively used as a building material for parts where strength is required.

Claims (1)

[Claims] (1) After mixing and kneading materials containing an inorganic hydraulic substance, pulp, reinforcing fibers, and thickener with water to obtain an inorganic curable composition, mold this inorganic curable composition into a desired shape. A method for producing a fiber-reinforced inorganic cured material by curing and curing, in which pulp with a long fiber length and reinforcing fibers with a long fiber length or a small fiber diameter are disintegrated in a large amount of water and adjusted to a moisture content of 75% or more. After that, 1 part by weight or more of a thickener is added to 100 parts by weight of the pulp in this preparation, and an amount that does not exceed the water content of the inorganic curable composition to be obtained is equal to or greater than the water content of this preparation. Fiber-reinforced inorganic curing characterized by adding water to the preparation and mixing, and mixing and kneading this mixture with other materials containing an inorganic hydraulic substance as a main component to obtain an inorganic curable composition. How the body is manufactured.