JPH0671726B2 - Water-permeable resin type for inorganic products - Google Patents

Description

Description: TECHNICAL FIELD 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.

[Prior art] For cement boards with patterns and ceramics boards, a molding tool made of gypsum has been used so far, the raw material slurry is filled in the molding tool, and the water permeability of the gypsum mold is used to drain the molded product. It is manufactured by curing and curing it. However, the above-mentioned plaster mold has a drawback that its water passage is clogged immediately, and recently,
Instead of the plaster mold as described above, a resin-made mold having continuous ventilation holes has been used. The resin material used for this type of synthetic resin mold has a water-permeable passage formed by continuous pores, and various methods have been proposed for forming continuous pores. As a first method, a gaseous substance (steam,
There is a method (Japanese Patent Publication No. 49-8006) of forming with formaldehyde, ammonia, etc. As a second method,
A method in which a foaming gaseous substance is mixed with a synthetic resin molding material and the communicating gas is formed by the foaming gas (JP-A-48-17811).
Issue gazette). As a third method, a method in which a synthetic resin powder and an inorganic powder are mixed to form a predetermined shape, and then the synthetic resin powder is melted, and the melting trace is formed in the continuous air vent (Japanese Patent Laid-Open No. 5038787). ).

[Problems to be solved by the invention]

However, each of the above methods has its own drawbacks.
It has not been put to practical use. That is, in the first method, the elastic modulus of the synthetic resin itself is lowered and softened due to the formation of the communicating holes, and the mechanical strength of the molding die is not good. An example of such a material is a urethane foam type. Further, there are problems that the generated pores are unlikely to be continuous pores only with the above-mentioned gaseous substance, and the pore diameter cannot be properly controlled. In the second method, since the gaseous substance must be mixed uniformly,
Although it is possible to stabilize the gaseous substance until the synthetic resin is cured, it is extremely difficult to control the pore diameter, and it is difficult to keep the pore diameter within an appropriate range. Further, according to the third method, when the synthetic resin is heated and melted, the plastic flow causes clogging, and the generated pores do not become continuous pores but become independent bubbles.

The present invention has been made in view of the above circumstances, and provides a water-permeable resin mold for inorganic products, which has continuous pores, an appropriate pore diameter, and sufficient mechanical strength as a molding die. Is its purpose.

[Means for solving problems]

In order to achieve the above-mentioned object, the water-permeable resin mold for an inorganic product of the present invention has a space filled with a raw material slurry for an inorganic product, and a continuous ventilation hole for draining extending from the internal space to an outer peripheral portion. A water-permeable resin type that is distributed and formed, and is mainly composed of a synthetic resin, an inorganic filler, and a natural plant resin, and the communication holes are voids formed by the inorganic filler particles and natural plant fibers. It is formed by.

[Action]

That is, the present invention is that the natural vegetable fiber is hollow, the outer peripheral surface thereof is pleated, and the outer peripheral surface of the filler particles is pleated, and the filler in the resin mold is It is a technique to form open pores by skillfully combining the fact that voids are created between particles, and as a result, the generated open pores have a physically constant pore size range depending on the filler particles and the fiber diameter of the fibers. It will fit inside. Moreover, since the filler particles and the natural vegetable fibers have a reinforcing effect by themselves, the effect improves the overall strength and provides a sufficient water-permeable mechanical strength.

The water-permeable resin type for inorganic products of the present invention (hereinafter abbreviated as “water-permeable resin type”) is mainly composed of a synthetic resin, a filler, and a natural plant fiber. Here, the term “subject” is intended to include a case where the entire subject consists of only the subject.

The synthetic fiber is not particularly limited,
From the viewpoint of water-permeable mechanical strength, it is preferable to use a thermosetting resin such as an epoxy resin or a phenol resin.

Also, the filler is not particularly limited, and examples thereof include silica stone, feldspar, alumina, calcium carbonate, and the like, and the average particle diameter is preferably about 5 to 300 μm, and preferably 30 to 150 μm. These inorganic filler particles have a pleated outer peripheral surface due to crushing or the like.

Examples of the natural plant fiber used together with the synthetic resin and the inorganic filler include cotton fiber, hemp fiber, pulp fiber and the like. These plant fibers are hollow and the outer peripheral surface is formed in a pleated shape. These natural vegetable fibers have an average fiber length of about 10 to 500 μm and preferably 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 1
It is in the range of 0 to 50 μm.

The mixing ratio of the inorganic filler and the natural vegetable fiber is, on a weight basis, the inorganic filler (A) and the natural vegetable fiber (B) = 1:
It is preferable to set it within the range of 1.5 to 1: 3.0. Further, the ratio of the inorganic filler to the synthetic resin and the natural vegetable fiber is 500 to 2000 parts, preferably 700 to 1700, of the inorganic filler with respect to 100 parts by weight of the synthetic resin (hereinafter abbreviated as "part"). It is desirable to set it so that it is a ratio of 10 parts to 100 parts per 100 parts of synthetic resin.
Part, preferably 30 to 100 parts. By setting the above raw materials in the above proportions, it becomes possible to obtain a water-permeable resin mold in which the pore diameters and distribution states of the continuous air vents are within appropriate ranges.

The water-permeable resin mold of the present invention is manufactured using the above-mentioned raw materials, for example, as follows. That is, the thermosetting resin (main agent + curing agent) as described above, an inorganic filler such as silica stone particles, and a natural plant fiber such as cotton fiber are blended at a predetermined ratio. Since this blend is in the form of powder and lacks in viscosity, it cannot be sufficiently mixed even in an ordinary mixer. Therefore, using a Banbury mixer or nider whose biaxial mixing blades rotate in opposite directions,
Alternatively, mixing is performed by using a super mixer. When using a super mixer, 500r
Mixing is done for about 15 minutes at pm. Next, the mixture thus obtained is put into a predetermined mold, and 50 to 200
80 ° C, preferably 80% water resistant resin
Harden by heating at a temperature of ~ 120 ° C for 4-40 hours. In this case, two-stage heating may be performed. Then, by removing the molded product obtained after heating from the mold,
The water-permeable resin mold of this invention can be obtained.

The water-permeable resin mold thus obtained has continuous pores, the pore diameter is within an appropriate range, and the mechanical strength of the molding die is sufficiently maintained. The reason why the water-permeable resin mold mainly composed of the synthetic resin, the inorganic filler, and the natural vegetable fiber has the above-mentioned excellent properties is considered as follows. That is, voids are formed between the particles of the inorganic filler, the voids are the main constituent parts of the communicating pores, and the hollow natural vegetable fibers therein form the communicating passages between the voids. It intervenes between the filler particles and the particles to make voids communicate with each other. Therefore, it is considered that the voids formed between the inorganic filler particles and the particles are wholly continuous and in the form of continuous air holes. In this case, since there are folds on the outer peripheral surface of the natural vegetable fiber and also folds between the particles of the inorganic filler, voids are also formed between the folds and the pleats are in communication with each other. It is thought to be useful for forming pores. In particular, natural plant fibers have flexibility, and can be interposed between the inorganic filler and the filler by following the shape of the particles and flexibly deforming. Therefore, it is considered that the voids formed between the inorganic filler particles can be smoothly communicated with each other. In addition, since the hollow of the natural plant fiber is extremely fine, the matrix resin does not get stuck in the hollow. In the water-permeable resin type in which such natural vegetable fiber is a constituent component, since the natural vegetable fiber itself has good compatibility with water, it is considered that this acts to improve the drainability of the raw material slurry. To be

〔The invention's effect〕

As described above, the water-permeable resin mold of the present invention is mainly composed of a synthetic resin, an inorganic filler and a natural plant fiber,
Since the continuous pores are formed by the voids formed by the inorganic filler particles and the natural plant fibers, the pore diameter is appropriate, and the natural plant fibers forming the pores, the inorganic filler itself, Since it functions as a reinforcing agent, it has sufficient mechanical strength as a molding die.

Next, examples will be described.

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

Next, put the above mixture in a super mixer, 500 rpm
Mix for 15 minutes. After putting the resulting mixture into a mold, 80
The resin was cured by heating at ℃ for 10 hours and at 120 ℃ for 10 hours to obtain the desired water-permeable resin mold.

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

Next, the water permeation performance of the water permeable resin mold obtained as described above was examined and shown in Table 3 below.

The water permeability was measured as follows. Second
Using a test piece (outer diameter 100 mm, thickness 20 mm) 20 shown in the figure, hang it on the measuring device shown in FIG. 3, connect it to a vacuum pump (not shown) from below, and suction at 60 mmHg with a pipe 21 ( The pressure was reduced), and the time until 100 ml of water 22 permeated and disappeared from the upper surface of the test piece was measured. This measurement is 10 ~
After repeating 20 times, the water permeation rate became constant within ± 5 seconds, and the test was repeated 5 times, and the average value was used as the data of water permeation rate. The number of test pieces was five. In FIG. 3, reference numeral 23 is a transparent resin cylinder, 24 is a base part to which they are attached, 25 is an O-ring for sealing, and 26 is a supporting leg.

As is clear from Tables 2 and 3, the products of Examples all have excellent performance. On the other hand, in the conventional example, the mechanical strength represented by bending strength is low, and the variation in pore diameter is large, so that it cannot be practically used as a water-permeable resin type.

BRIEF DESCRIPTION OF THE 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 performance test, and FIG. 3 is a sectional view of a water permeability performance measuring device. 1 ... Mold (upper mold), 2 ... Mold (lower mold), 3, 4 ...
… Frame, 5,6 …… Non-permeable resin, 7,8 …… Vacuum suction pipe, 9 …… Material slurry, 10 …… Molded body, 11 …… Pressure inlet

Claims (1)

[Claims] 1. A water-permeable resin type having a space filled with a raw material slurry for an inorganic product and having distributed ventilation holes for draining extending from the internal space to an outer peripheral portion, which is a synthetic resin. And an inorganic filler and a natural vegetable fiber as a main component, wherein the continuous air holes are formed by the voids formed by the inorganic filler particles and the natural vegetable fiber. Water-permeable resin type.