JPH0292849A - 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 hollow synthetic 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 hollow synthetic fiber with said communicating voids formed by both the inorganic filler and the hollow synthetic fiber. Within this mold, voids formed by the filler granules are innumerably distributed, being made communicable through the hollows of said hollow fiber and narrow spaces formed by said fiber and granules; thus resulting in proper diameter and distribution for the communicating voids, furthermore, said fiber and filler serve as reinforcing agent, therefore 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. Raw material slurry is filled inside the mold, 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 Patent Laid-Open 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 trace into a continuous hole (Japanese Patent Laid-Open No. 50-38710). ).

[Problems to be solved by the invention] However, each of the above methods has its own difficulties.
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 hollow synthetic fibers, and the communicating pores are voids created by the inorganic filler particles and hollow synthetic fibers. It takes the structure that it is formed by.

[Effect]

That is, in the water-permeable resin mold for inorganic products of this invention,
In the mold, there are countless voids formed between the filler particles, and these voids are the hollows and hollows of the hollow synthetic fibers sandwiched between the filler particles. The synthetic fibers and the voids formed between the filler particles communicate with each other to form communicating pores. Therefore, the pore size and distribution of the generation communication pores becomes appropriate. Moreover, since the hollow synthetic fibers and inorganic filler particles themselves act as reinforcing agents, their use improves the strength of the water-permeable resin mold itself.

The water-permeable resin mold for inorganic products of the present invention is mainly composed of a synthetic resin, a filler, and a hollow synthetic 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.

The hollow synthetic fiber used together with the synthetic resin and inorganic filler is not particularly limited, and may be made of any material as long as it is hollow. For example, polyester fiber etc. can be mentioned. The hollow synthetic 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 25 to 300 parts m,
The outer diameter is within the range of 10 to 50 μm.

The blending ratio of the above inorganic filler and hollow synthetic fiber is inorganic filler (A) and hollow synthetic fiber (B) = 1:1.5 to 1.
: It is preferable to set it within the range of 3.0. In addition, the ratio of the inorganic filler to the synthetic resin and the hollow synthetic fiber is 500 to 2000 parts of the inorganic filler to 100 parts by weight of the synthetic resin (hereinafter abbreviated as "parts").
It is desirable to set the ratio to be 700 to 1700 parts, and the amount of hollow synthetic fibers is 10 to 150 parts, preferably 30 to 100 parts, based on 100 parts of the synthetic resin. By setting the above-mentioned raw materials in the above proportions, a water-permeable resin mold can be obtained in which the communicating pores are within an appropriate range and are evenly distributed throughout.

The water-permeable resin mold for inorganic products of the present invention is manufactured using the above-mentioned raw materials, for example, in the following manner. The filler and natural vegetable fibers such as cotton fibers 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, mixing is carried out using a Banbury mixer or kneader in which two shaft mixing blades rotate in opposite directions, or a super mixer. When using a super mixer, mixing is performed at 500 rpm for about 15 minutes. Next, the mixture thus obtained is placed in a predetermined mold and heated 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.
Heat and cure for 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 for inorganic products obtained in this way is
The pores are continuous, the pore diameter is within an appropriate range, and it maintains sufficient mechanical strength as a mold. The reason why the water-permeable type mainly composed of synthetic resin, inorganic filler, and hollow synthetic fibers has the above-mentioned excellent properties is considered to be due to the following reasons. In other words, 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 synthetic fibers are filled with the inorganic filler so that the hollow synthetic fibers form a connection path 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 the hollows of the hollow synthetic fiber are extremely fine,
The matrix resin will not enter the pores and cause clogging.

〔Effect of the invention〕

As described above, the water-permeable resin mold for inorganic products of the present invention is mainly composed of a synthetic resin, an inorganic filler, and a hollow synthetic fiber, and the communicating pores are created by the inorganic filler particles and the hollow synthetic fiber. Since it is formed by voids, the pore diameter is appropriate, and the hollow synthetic fibers and inorganic filler that form the pores themselves function as reinforcing agents, so they have sufficient mechanical strength as a mold. ing.

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 resulting mixture was put into a mold and heated at 80°C for 10 hours and at 120°C for 10 hours to harden the resin, thereby obtaining the intended water-permeable resin mold for inorganic products.

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

(The following is a blank space.) Next, the water permeability of the water permeable resin mold for inorganic products obtained as described above was investigated, and the results are 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 100 ml of water 22 to permeate and disappear from the top surface of the test piece was measured. This measurement was repeated 10 to 20 times, and after the water permeation rate became constant at ±5 seconds, the test was repeated 5 more 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,
25 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 example 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 object 11...pressure port

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 hollow synthetic fiber, wherein the communicating pores are formed by voids formed by the inorganic filler particles and the hollow synthetic fiber. Water-permeable resin mold for products.