JPH0585796A - Manufacture of fiber-reinforced inorganic material body - Google Patents

Abstract

PURPOSE:To improve the strength by preparing an emulsion incorporating a water-insoluble vinyl monomer containing a water hardened material, a specific reinforcing fiber, water, a polymerization initiator and an emulsifier, forming it and then hardening and curing it. CONSTITUTION:The water hardened material including cement of 100 parts wt. and the water-insoluble vinyl monomers of 1-150 parts wt. of styrene, etc., including the reinforcing fibers of 1-20mm of an average length of acrylic fibers, etc., stuck with a surface active agent less than 13 in the HLB, of 0.4-40 parts wt., water of 20-500 parts wt., the polymerization initiator of 0.5-5wt.% and the emulsifier of 3-50wt.%, are mixed with a kneader, etc., to prepare the emulsion. Next a molded body formed and obtained with an extruder, etc., is hardened by leaving it in vacuum and later it is cured in steam, an then the fiber reinforced inorganic material body being superior to the strength and tenacity is obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a fiber-reinforced inorganic material suitable as a building material such as a wall material, a roof material and a floor material, and a civil engineering material such as a pipe, a panel and a trough.

[0002]

2. Description of the Related Art Conventionally, asbestos has been widely used to reinforce hydraulic substances such as cement and gypsum.

[0003] However, asbestos is a natural material and its price fluctuates greatly, and since it has become clear that asbestos dust is harmful to health and hygiene in recent years, its use is being repelled or restricted. Therefore, the development of a fiber material that replaces asbestos is being studied on a global scale including Japan.

[0004] As fiber materials that have replaced asbestos so far, for example, glass fiber, rock wool, carbon fiber,
Many fibers have been proposed, such as steel fibers, aramids, olefinic fibers, vinylon and acrylic fibers. Among these alternative fibers, acrylic fiber, which is inexpensive and has excellent alkali resistance and adhesiveness to hydraulic substances such as cement, has attracted attention and has begun to be used for reinforcing materials such as siding boards, slate and roofing materials. It was

By the way, in JP-A-1-176258, an emulsion containing cement, short fibers of synthetic fiber, water, and a water-insoluble vinyl monomer containing a polymerization initiator and an emulsifier is extrusion-molded, A method for producing an inorganic body by curing and drying the obtained molded body is described.

According to this method, the emulsion has high fluidity because the slurry composed of cement and water forms the emulsion in the water-insoluble vinyl monomer, and
It has excellent thixotropy and enables extrusion at low pressure without impairing the shape retention.

However, in an emulsion containing the above cement, water and a water-insoluble vinyl monomer,
There is a problem that it is difficult to uniformly disperse the synthetic short fibers without breaking the emulsion.

[0008]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems of the conventional method, that is, the molding pressure can be lowered, and the stability of the emulsion and the dispersibility of the reinforcing fiber can be improved. It is an object of the present invention to provide a method capable of obtaining an inorganic material having high strength and excellent toughness because it can be improved.

[0009]

In order to achieve the above-mentioned object, the present invention provides a hydraulic material containing cement and H
A step of preparing an emulsion containing a reinforcing fiber to which a surfactant having an LB of 13 or less is attached, water, and a water-insoluble vinyl monomer containing a polymerization initiator and an emulsifier; and a step of molding the emulsion, And a step of curing and curing the formed body, the method for producing a fiber-reinforced inorganic body is provided.

In the present invention, first, a hydraulic material containing cement, a reinforcing fiber to which a surfactant having an HLB of 13 or less is attached, water, and a water-insoluble vinyl monomer containing a polymerization initiator and an emulsifier. Prepare the containing emulsion.

Cement is a main raw material of the inorganic material, and for example, plain cement such as Portland cement and alumina cement, mixed cement such as blast furnace cement, and special cement such as expansion cement can be used. Among these, a non-shrinkable cement that is a kind of expanded cement and is composed of calcium silicate, which is a compositional compound of Portland cement, and hain, gypsum, and blast furnace slag (such as Chichibu High Aculus manufactured by Chichibu Cement Co., Ltd.) Is preferably used because ordinary steam curing gives dimensional stability equivalent to that of autoclave curing.

For the hydraulic material, polystyrene beads, polyvinylidene chloride beads, and polyvinylidene chloride beads are used in an amount of 0.5 to 50% by weight in order to reduce the density and obtain a lightweight inorganic material.
Light weight aggregates such as perlite, shirasu balloon, and glass balloon can also be blended. Further, in order to further improve the moldability, wood pulp, acrylic, fibrils of aromatic polyamide, wollastonite, edenite, sepiolite, mica, talc, bentonite and the like are added to the molding aid. May be.

On the other hand, the reinforcing fiber acts as a reinforcing material,
Improves the mechanical properties of the inorganic material. As such reinforcing fibers, it is preferable that it has resistance to alkali, and also has high strength and high elastic modulus, for example, carbon fibers, alkali resistant glass fibers, aromatic polyester fibers, polyethylene fibers, aramid fibers, acrylic fibers, Vinylon fiber or the like is used. Among these, acrylic fiber is most preferably used because it has excellent adhesiveness with cement. Specifically, it is preferable that the acrylic polymer has a high acrylonitrile content and a high degree of polymerization. For example, a tensile strength of 10 g / denier or more and a tensile modulus of 180 g obtained by dry-wet spinning an acrylonitrile-based polymer containing at least 90 mol% acrylonitrile and having an intrinsic viscosity of 2.0 to 5.0.
/ Short fibers obtained by cutting acrylic fibers having a denier or more can be preferably used.

If the reinforcing fiber is too thin, the dispersion in the hydraulic material tends to be insufficient, and if it is too thick, the strength tends to be low, so that it is preferably about 0.1 to 7.0 denier. .. If the average length is too short, the reinforcing effect is insufficient, and if it is too long, the dispersibility tends to deteriorate and the homogeneity of the inorganic material tends to deteriorate, so the average length is preferably in the range of 1 to 20 mm. More preferable range is 4 to 1
It is 0 mm.

Here, the surfactant attached to the reinforcing fiber is HLB (Hydrophile Lipophi).
le Balance) is 13 or less, preferably 3 to 1
It is 0. HLB is a numerical value that represents the hydrophilicity of a surfactant as described in the Handbook of Surfactants (published by Sangyo Tosho) or the Introduction to New Surfactants (issued by Sanyo Kasei Co., Ltd.). In the present invention, Davis HLB that can be applied not only to nonionic surfactants but also to anionic and cationic surfactants is used. This HL
A hydraulic substance as described later when B is greater than 13,
The formation of an emulsion containing water and a water-insoluble vinyl monomer becomes unstable, and the dispersibility of the reinforcing fiber is reduced, so that the reinforcing effect of the reinforcing fiber cannot be sufficiently expressed,
An inorganic material having high strength and high toughness cannot be obtained.

As a surfactant having an HLB of 13 or less, for example, hydrocarbons such as mineral oil, fatty acids such as oleic acid and esters thereof, sorbitan monostearate and sorbitan monostearate ethylene oxide adduct (ethylene oxide 4 mol). Such as polyhydric alcohol ester and its ethylene oxide adduct, polyethylene glycol (molecular weight 400) monooleate and other polyethylene glycol ester, lauryl alcohol ethylene oxide adduct (ethylene oxide 5 mol) and other higher alcohol ethylene oxide adduct, and nonylphenol ethylene oxide Nonionic surfactants such as alkylphenol ethylene oxide adducts such as adducts (6 moles of ethylene oxide) are used, but HLB is 1 by itself. Greater than nonionic, anionic, HLB and cationic and amphoteric surfactants and HLB of 13 or less non-ionic surfactant as a whole a plurality mixed may be set to be 13 or less. Among these,
Anionic surfactants are preferably used because they have excellent adhesiveness to cement.

Although the amount of the surface active agent deposited depends on the size of the HLB, it is preferably 0.01 to 1% by weight, more preferably 0.02 to 0.5% by weight, based on the reinforcing fiber.
Is desirable. If it is out of this range, the emulsion tends to be disintegrated and the dispersibility of the reinforcing fiber tends to be lowered.

The method of depositing the surfactant is not particularly limited, but for example, a dipping method, a spray method, a kiss roll method and the like are used. Further, the surface active agent may be evenly coated or partially adhered to the surface of the reinforcing fiber.

On the other hand, in the present invention, a water-insoluble vinyl monomer containing a polymerization initiator and an emulsifier is prepared.

As the water-insoluble vinyl monomer, styrene, α-methylstyrene, acrylic acid ester, methacrylic acid ester, acrylonitrile, divinylbenzene,
Acrylic acid ester of alkylene glycol, methacrylic acid ester of alkylene glycol, acrylic acid ester of polyhydric alcohol, methacrylic acid ester of polyhydric alcohol and the like can be used, and these can be used alone or in combination of two or more kinds. These are liquids at room temperature. Of these, inexpensive styrene is preferable.

As the polymerization initiator, a radical generator or a redox catalyst such as benzoyl peroxide or t-butyl peroxybenzoate can be used. The blending amount is preferably in the range of 0.5 to 5% by weight.

Furthermore, the emulsifier is not particularly limited, but a nonionic surfactant having an HLB of 3 to 6, such as sorbitan sesquioleate, glycerol monostearate, sorbitan monooleate,
At least one of diethylene glycol monostearate, sorbitan monostearate, diglycerol monooleate, and maleic anhydride adduct of alkylene glycol can be preferably used. Of these, sorbitan monooleate and diglycerol monooleate are preferable. If the blending amount is too small, the stability of the emulsion tends to be low, and if it is too large, the shrinkage at the time of polymerization of the vinyl monomer tends to be large.
It is preferably in the range of 3 to 50% by weight.

The water-insoluble vinyl monomer may be a divinyl compound or a trivinyl compound, such as dimethacrylate of a polyhydric alcohol, ethylene glycol dimethacrylate or trimethylolpropane trichloride, for the purpose of improving the strength and heat resistance of the resulting inorganic material. It is also preferable to add methacrylate or the like.

In the present invention, an emulsion containing the above-mentioned hydraulic material containing cement, reinforcing fibers, water, and a water-insoluble vinyl monomer containing a polymerization initiator and an emulsifier is prepared. It is preferable to carry out as follows.

That is, with respect to 100 parts by weight of the above-mentioned cement-containing hydraulic material, 0.4 to 40 parts by weight of reinforcing fiber, 20 to 500 parts by weight of water, a water-insoluble vinyl containing a polymerization initiator and an emulsifier. Add 1 to 150 parts by weight of the monomer, stir and mix well using a mixer or kneader,
Obtain an emulsion. However, the reinforcing fiber may be added to the obtained emulsion, other raw materials,
For example, it may be added in advance to the water-insoluble vinyl monomer. Alternatively, a mixture of a hydraulic substance, reinforcing fibers, and water may be prepared in advance, and this may be mixed with a water-insoluble vinyl monomer. The order of the mixing operations is not critical to the invention.

In this stirring and mixing operation, the reinforcing fiber content is preferably 0.4 to 40 parts by weight with respect to 100 parts by weight of the hydraulic substance, as described above.
If it is less than 0.4 parts by weight, the reinforcing effect is reduced, and
If it is more than 40 parts by weight, the dispersibility tends to decrease, and the homogeneity of the inorganic material tends to decrease.

The amount of water is preferably 20 to 500 parts by weight. If it is less than 20 parts by weight, the viscosity of the emulsion becomes high and the pressure during molding rises.
If the amount is more than 500 parts by weight, the weight of the resulting inorganic material will be reduced, but the strength tends to be low.

Further, the amount of the water-insoluble vinyl monomer containing the polymerization initiator and the emulsifier is preferably in the range of 1 to 150 parts by weight. If it is less than 1 part by weight, the stability of the emulsion tends to be low, and if it is more than 150 parts by weight, the strength and dimensional stability of the inorganic material tend to be lowered. The content of the polymerization initiator and the emulsifier in the water-insoluble vinyl monomer is preferably 0.5 to 5% by weight of the polymerization initiator and 3 to 50% by weight of the emulsifier.

In the present invention, next, the above-mentioned emulsion is molded into a desired shape, for example, a plate shape, a hollow plate shape, or other complicated three-dimensional shape to obtain a molded body. As the molding method, a method of pouring the emulsion into the released mold, a so-called casting method, an extrusion molding method, a method of press-fitting into a closed mold, a so-called injection molding method, etc. are not particularly limited. Used. Among these, the method of injecting the emulsion into the closed mold under pressure using an extruder or a plunger is preferable because it can be molded into a complicated or large three-dimensional shape.

In this molding operation, since the above-mentioned emulsion of the present invention is used, the pressure during molding is 0.1.
It can be as low as ~ ² kg / cm ² .

In the present invention, next, the obtained molded body is cured and cured to improve strength and toughness. The curing and curing are preferably carried out under steam at 100 ° C. or lower, but at this time, the polymerization of the vinyl monomer and the hydration reaction of the hydraulic substance may be carried out simultaneously or separately. For example, a method of curing in steam at 50 to 60 ° C. and then curing in steam at 80 to 100 ° C. is used. Further, in order to improve the dimensional stability, autoclave curing may be carried out after the above curing and curing.

When curing in an autoclave, 100 to 1
It is preferably carried out under steam at 80 ° C. for 3 to 15 hours.

[0033]

【Example】

Examples 1-2, Comparative Examples 1-2 With respect to 100 parts by weight of Portland cement which is a cement, 40 parts by weight of water and 1% by weight of a polymerization initiator t-.
Butyl peroxybenzoate, 33% by weight of emulsifier sorbitan monooleate and crosslinker,
After stirring and mixing with a kneader 10 parts by weight of a styrene monomer containing 7% by weight of trimethylolpropane trimethacrylate, 0.1% by weight of the surfactant shown in Table 1 was adhered thereto. Acrylic short fibers with a fineness of 2 denier, a tensile strength of 11.7 g / denier, a tensile modulus of 200 kg / denier and an average length of 6 mm (Toray Industries, Inc.).
The product "Atlan") was added so as to be 1.5 parts by weight with respect to 100 parts by weight of the above hydraulic material, and similarly stirred and mixed with a kneader.

Next, the above emulsion was extruded and molded using an extruder to obtain a plate-shaped molded product having a thickness of 6 mm. The extrusion pressure at this time was 0.6 kg / cm ² .

The stability of the emulsion was qualitatively evaluated by observing the water separated from the emulsion during extrusion.

Next, the molded body was cured by leaving it in steam at 60 ° C. for 8 hours, and then cured in steam at 80 ° C. for 20 hours. The specific gravity of the plate-like inorganic material thus obtained was about 1.3, and the bending strength in the three-point bending test was as shown in Table 1. It can be seen from Table 1 that the production method of the present invention is excellent in emulsion stability and fiber separability, so that a fiber-reinforced inorganic material having a high reinforcing effect can be obtained.

[0037]

[Table 1]

[0038]

According to the present invention, since the dispersibility of reinforcing fibers can be improved while maintaining good emulsion stability, a fiber-reinforced inorganic material having high strength and excellent toughness can be obtained.

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Claims (5)

[Claims] 1. A hydraulic substance containing cement and HLB of 1
A step of preparing an emulsion containing reinforcing fibers having 3 or less surfactants attached thereto, water, and a water-insoluble vinyl monomer containing a polymerization initiator and an emulsifier, and a step of molding the emulsion were obtained. A method for producing a fiber-reinforced inorganic body, which comprises the steps of curing and curing the molded body. 2. In the step of preparing an emulsion, 0.4 parts by weight or more and 40 parts by weight or less of reinforcing fibers having a surfactant having an HLB of 13 or less attached to 100 parts by weight of a hydraulic material containing cement, 20 parts by weight or more of water, 500
1 part by weight or more and 150 parts by weight or less of a water-insoluble vinyl monomer containing 0.5 parts by weight or less, 0.5% by weight or more and 5% by weight or less of a polymerization initiator and 3% by weight or more and 50% by weight or less of an emulsifier. The method for producing the fiber-reinforced inorganic material according to claim 1. 3. The method for producing a fiber-reinforced inorganic material according to claim 1, wherein the reinforcing fiber has an average length of 1 mm or more and 20 mm or less. 4. The reinforcing fiber is an acrylic fiber.
Alternatively, the method for producing the fiber-reinforced inorganic material according to the item 2. 5. The method for producing a fiber-reinforced inorganic material according to claim 1, 2, 3 or 4, wherein the water-insoluble vinyl monomer is styrene.