JPH0292850A - Water-penetrable resinous mold for inorganic product - Google Patents

Abstract

PURPOSE:To provide the title resinous mold made the size of voids included adequate and improved in mechanical strength, comprising a synthetic resin, inorganic filler and natural vegetable fiber, so designed that the voids are formed by the latter two components. CONSTITUTION:The objective resinous mold has a space in its interior to be filled with raw material slurry for an inorganic product, includes communicating voids extending from this space to the outer peripheral part, and is comprised of a synthetic resin, inorganic filler and natural vegetable fiber with said communicating voids formed by both the inorganic filler and the natural vegetable fiber. Within this mold, voids are formed among the granules of said filler, mainly defining the communicating voids; furthermore, said hollow fiber with its outer peripheral surface ribbed is present among the granules, communicating the voids; thus resulting in proper diameter of said communication voids. In addition, said fiber and filler serve as reinforcing agents, improving the mechanical strength of the mold.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a water-permeable resin mold for inorganic products, which is used as a mold for inorganic products such as concrete parts and ceramic parts.

[Conventional technology]

Until now, patterned cement boards and ceramic boards have been made using plaster molds.The inside of this mold is filled with raw material slurry, and water is drained using the water permeability of the plaster mold to create a molded product, which is then cured and hardened. It is manufactured by drying or firing. However, the above-mentioned plaster mold has the disadvantage that its permeable channel easily gets clogged, and recently,
Instead of the above-mentioned plaster molds, resin molds having communicating holes are now being used. The resin material used in this type of synthetic resin mold has a permeable channel formed by continuous pores, and various methods have been proposed for forming the continuous pores. The first method is to use gaseous substances (water vapor,
Formaldehyde, ammonia, etc.) (Japanese Patent Publication No. 49-8006). The second method is to mix a foaming gaseous substance into a synthetic resin molding material and form continuous pores with the foaming gas (Japanese Unexamined Patent Publication No. 48
-17811). A third method is to mix synthetic resin powder and inorganic powder to form a predetermined shape, then melt the synthetic resin powder, and form the melted traces of the can into continuous holes (Japanese Patent Laid-Open No. 50-38710). There is a public notice).

[Problem that the invention seeks to solve]

However, each of the above methods has its own drawbacks.
It has not yet been put into practical use. That is, in the first method, the elastic modulus of the synthetic resin itself decreases and becomes soft due to the formation of the communicating holes, and the mechanical strength as a mold is lost. An example of this type is a urethane foam type.

In addition, when the gaseous substance is used alone, the pores that are generated are difficult to form continuous pores, and the pore diameter cannot be properly controlled. In the second method, the gaseous substance must be mixed uniformly, so although it is possible to stabilize the gaseous substance until the synthetic resin hardens, it is extremely difficult to control the pore size. It is difficult to keep it within an appropriate range. According to the third method,
When a synthetic resin is heated and melted, clogging occurs due to plastic flow, and the pores formed become closed cells instead of continuous pores.

The present invention was made in view of the above circumstances, and an object of the present invention is to provide a water-permeable resin mold for inorganic products, which has continuous pores, an appropriate pore diameter, and sufficient mechanical strength as a mold. That purpose.

[Means for solving problems]

In order to achieve the above object, the water-permeable resin mold for inorganic products of the present invention has an interior space filled with a raw material slurry for inorganic products, and a communication hole for drainage extending from the interior space to the outer periphery. It is a water-permeable resin type that is distributed and formed mainly of synthetic resin, inorganic filler, and natural vegetable fiber, and the communicating pores are voids created by the inorganic filler particles and natural vegetable fiber. It takes the structure that it is formed by.

[Function] That is, the present invention requires that the natural vegetable fiber is hollow and has a pleated outer circumferential surface, and that the outer circumferential surface of the filler particles is pleated and that the outer circumferential surface of the natural vegetable fiber is hollow, and that the outer circumferential surface of the filler particles is pleated and In this method, continuous pores are formed by skillfully combining the voids formed between the filler particles, and as a result, the continuous pores formed have a physically constant pore size depending on the filler particles and the fiber diameter of the fiber. It will fall within the range. Furthermore, since the filler particles and natural vegetable fibers themselves have a reinforcing effect, this effect improves the overall strength and provides sufficient mechanical strength as a water-permeable type.

The water-permeable resin mold for inorganic products (hereinafter abbreviated as "water-permeable resin mold") of the present invention is mainly composed of synthetic resin, filler, and natural vegetable fiber. Here, the term "subject" is intended to include cases where the whole consists only of the subject.

The above synthetic resins are not particularly limited, but include:
From the viewpoint of water-permeable mechanical strength, it is preferable to use thermosetting resins such as epoxy resins and phenol resins.

Further, the filler is not particularly limited, and examples include silica, feldspar, alumina, calcium carbonate, etc., and the average particle size is preferably about 5 to 300 μm, preferably 30 to 150 μm.

These inorganic filler particles have a pleated outer peripheral surface due to crushing or the like.

Natural plant fibers used together with the synthetic resin and inorganic filler include fibers such as cotton fibers, hemp fibers, and bulb fibers. These vegetable fibers are hollow and have pleated outer peripheral surfaces. These natural plant fibers preferably have an average fiber length of about 10 to 500 μm and an outer diameter of about 5 to 90 μm. Most preferably, the average fiber length is about 40 to 250 μm and the outer diameter is in the range of 10 to 50 μm.

The blending ratio of the above inorganic filler and natural plant fiber is based on weight, inorganic filler (A) and natural plant fiber (B) = 1
:1.5 to i:a, o. In addition, the ratio of the inorganic filler and natural vegetable fiber to the synthetic resin is 100 parts by weight of the synthetic resin (
(hereinafter abbreviated as "parts"), the inorganic filler is 500~
It is desirable to set the ratio to be 2000 parts, preferably 700 to 1700 parts, and the natural vegetable fiber is 10 to 150 parts, preferably 30 to 1 part, to 100 parts of the synthetic resin.
It is desirable to set it to 00 copies. By setting each of the above raw materials in the proportions shown above, the pore diameter of the continuous pores can be reduced to 1
A water-permeable resin mold whose distribution state falls within an appropriate range can now be obtained.

The water-permeable resin mold of the present invention is manufactured using the above-mentioned raw materials, for example, in the following manner. That is, the thermosetting resin (base resin + curing agent) as described above, an inorganic filler such as silica particles, and a natural vegetable fiber such as cotton fiber are blended in a predetermined ratio. Since this compound is powder-like and lacks viscosity, it cannot be mixed sufficiently even with a normal mixer. Therefore, using a Banbury mixer or kneader in which two shaft mixing blades rotate in opposite directions,
Alternatively, mixing may be performed using a super mixer. When using a super mixer, 50
Mixing is performed at 0 rpm for about 15 minutes. Next, the mixture obtained in this way is poured into a predetermined mold,
The resin is heated and cured at a temperature of 50 to 200°C, preferably 80 to 120°C, which is less likely to cause distortion in the water-permeable resin mold, for 4 to 40 hours. In this case, two-stage heating may be performed. Then, by taking out the molded product obtained after heating from the mold, the water-permeable resin mold of the present invention can be obtained.

The water-permeable resin mold thus obtained has continuous pores and a pore diameter within an appropriate range, and also maintains sufficient mechanical strength as a mold. The reason why the water-permeable resin type mainly composed of synthetic resin, inorganic filler, and natural vegetable fiber has the above-mentioned excellent properties is thought to be due to the following reasons. . That is, voids are formed between the particles of the inorganic filler, and these voids become the main constituent parts of the communicating pores, and the hollow natural vegetable fibers are filled with the inorganic filler so that the hollow natural vegetable fibers constitute the communicating paths between the voids. It is interposed between the filler particles and connects the voids. Therefore, it is considered that the voids formed between the inorganic filler particles are continuous as a whole and form continuous pores. In this case, since there are folds on the outer circumferential surface of the natural vegetable fibers and also between the inorganic filler particles, voids are formed between the folds, and this is also due to the continuous pores. It is thought that it is useful for formation. In particular, natural vegetable fibers have flexibility and can be flexibly deformed and interposed between the inorganic filler and the filler to follow the shape of the particles. Therefore, it is considered that the voids formed between the inorganic filler particles can be smoothly communicated. Note that, since the hollow spaces in the natural vegetable fibers are extremely fine, the matrix resin does not enter the hollow spaces and cause clogging. In addition, in the case of water-permeable resin molds in which such natural plant fibers are a constituent component, since the natural plant fibers themselves have good affinity with water, we believe that this also works to improve the drainage properties of the raw material slurry. It will be done.

〔Effect of the invention〕

As described above, the water-permeable resin mold of the present invention is mainly composed of synthetic resin, inorganic filler, and natural vegetable fiber,
Since the communicating pores are formed by the voids created by the inorganic filler particles and natural plant fibers, the pore diameter is appropriate, and the natural plant fibers and inorganic filler that form the pores themselves are effective as reinforcing agents. In order to perform its functions, it has sufficient mechanical strength as a mold.

Next, examples will be described.

[Examples 1 to 3] First, the raw materials shown in Table 1 below were blended in the proportions shown in the table.

(Left below) Next, put the above mixture into a super mixer and add 500
Mixed for 15 minutes at rpm. The obtained mixture was put into a mold, and then heated at 80°C for 10 hours and at 120°C for 10 hours to harden the resin, thereby obtaining the desired water-permeable resin mold.

Table 2 shows the physical properties of the water-permeable resin mold thus obtained. Table 2 also shows, as a conventional example, the physical properties of water-permeable urethane foams in which pores are formed by gaseous substances generated during the curing process of synthetic resins.

(The following is a blank space) Next, the water permeability of the water permeable resin mold obtained as described above was investigated and is shown in Table 3 below.

The water permeability was measured as follows. Second
The test piece shown in the figure (outer diameter 100 mm.

20 (thickness: 20 mm) was hung on the measuring device shown in FIG. 3, and suctioned (depressurized) at 60 mmHg through a pipe 21 connected to a vacuum pump (not shown) from below.
The time required for water 22 of 100/d to permeate and disappear from the upper surface of the test piece was measured. Repeat this measurement 10 to 20 times, and after the water permeation rate becomes constant within ±5 seconds,
The test was repeated several times, and the average value was used as water permeation rate data. The number of test pieces was five. In Fig. 3, 23 is a transparent resin cylinder, 24 is a base to which it is attached, and 2
5 is an O-ring for sealing, and 26 is a support leg.

(The following is a blank space) As is clear from Tables 2 and 3, all of the implementation side holes have excellent performance. On the other hand, the conventional example has a low mechanical strength represented by bending strength and a large variation in pore diameter, making it impossible to put it to practical use as a water-permeable resin type.

[Brief explanation of drawings]

FIG. 1 is a sectional view of an embodiment of the present invention, FIG. 2 is a perspective view of a test piece for a water permeability test, and FIG. 3 is a sectional view of a water permeability measuring device. 1...Molding mold (upper mold) 2...Molding mold (lower mold) 3
4... Frame body 5, 6... Impermeable resin 7.8...
・Vacuum suction vibrator 9... Raw material slurry 10...
Molded body 11...Injection port Patent applicant Tokai Rubber Industries Co., Ltd. Agent Patent attorney Yukihiko Nishifuji Figure

Claims (1)

[Claims] (1) A water-permeable resin type having an interior space filled with a raw material slurry for inorganic products, and in which communicating holes for draining water extending from the interior space to the outer periphery are distributed and formed,
An inorganic material mainly composed of a synthetic resin, an inorganic filler, and a natural vegetable fiber, wherein the communicating pores are formed by voids created by the inorganic filler particles and the natural vegetable fiber. Water-permeable resin mold for products.