JPS63206368A - Foaming formation for inorganic material and forming mold therefor - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to foam molding of an inorganic foam molding material, and more specifically, the present invention relates to foam molding of an inorganic foam molding material. This invention relates to a method for molding a foam molded product and a mold used for the molding.

The inorganic foam molded product produced by the molding method of the present invention can be used for soundproofing materials, heat insulating materials, and other ml! ! material,
interior materials, or efsteria materials, packaging materials,
Can be used as cushioning materials and in a wide variety of other foam-like applications.

[Technical background and explanation of conventional technology]

To date, porous lightweight concrete products have been made by hardening lightweight aggregates such as pumice and volcanic gravel with cement and are widely used, and sodium silicate water glass has been used as an inorganic adhesive. Zn, AI, in water glass
It is known that water resistance can be improved by adding metal oxides such as Mg or Ca (Kanamaru, “Adhesives and Adhesives”).
p, 123-124).

It has also been proposed to foam-mold silica sand powder or other aggregates together with metal aluminum powder, silicon powder or ferro-silicon powder, and water glass to produce inorganic foam molded products (Japanese Patent Application Laid-Open No. 1983-1996-1). 77684
However, since inorganic foam molding using this method is foam molding using an open mold method, it is extremely difficult to create foam molded products with complicated shapes.
It is also difficult to produce foam molded products with uniform dimensions.

Furthermore, since the water glass adhesive has extremely high adhesion to inorganic materials, the mold used for molding it has been disposable, or the molding method has been based on an open mold method.

The present inventors have been conducting research on water glass-based materials for many years, and in their research, they found that pores with a diameter of 10 microns or less can pass air, water vapor, and other gas molecules, but water It was discovered that liquid materials such as glass are not allowed to pass through, and the present invention was achieved based on this finding.

[Object of the invention and summary of the invention]

An object of the present invention is to provide a method for molding an inorganic molding material that can produce an inorganic foam molded product that has a complex shape and grows independent cells, and a mold for use in the molding method.

In the foam molding of an inorganic foam molding material consisting of aggregate, water glass, and a blowing agent, the present invention provides a method for forming an inner wall surface with a diameter of 1 mm on the inner wall surface.
A closed mold having a pore size of 0 μ to 3.5 A and a large number of pores communicating with the outer surface is used as the mold, thereby preventing the liquid phase component of the inorganic foaming component from flowing out.
This is a method for foam molding an inorganic material, which is characterized in that only the outflow of gas within the mold caused by the volume expansion due to foaming of the inorganic foam molding material is smoothly performed.

In the foam molding of the inorganic material of the present invention, silica sand powder can be used as the aggregate, and metal aluminum powder, silicon powder, or ferrosilicon powder can be used as the foaming agent, but the metal aluminum powder is stearin. A material coated with a solid fatty acid such as an acid can be used, thereby retaining the activity of metallic aluminum.

In the foam molding of the inorganic material of the present invention, a water-repellent film with a water-repellent structure and a lll-type structure is interposed between the inorganic foam molding material and the inner wall surface of the mold, and foam molding is performed, thereby making it possible to demold the molded product. Porous films of tetrafluoroethylene, polypropylene or polyethylene can be used as films with water resistance and mold release properties.
A material having a large number of pores having a pore diameter of A is used, thereby allowing the gas in the mold to be smoothly discharged.

The mold used in the foam molding of the inorganic material of the present invention has a water-repellent mold release agent layer formed on its inner wall surface, which enables smooth demolding of the molded product and resists resistance. The aqueous mold release agent layer is a coating layer of tetrafluoroethylene,
A polypropylene covering layer or a polyethylene covering layer can be used, but it is also possible for the entire inner wall surface of the mold to be composed of a polypropylene, polyethylene or tetrafluoroethylene polymer.

Furthermore, in the foam molding of the inorganic material of the present invention, the mixed liquid of the inorganic foam molding material is filled into a mold leaving a space corresponding to the volume expansion due to foaming of the inorganic foam molding material, and foam molding is performed. A foam molded article having closed cells can be produced by this method, and the volume expansion due to foaming of the inorganic foam molding material can be detected by pre-foam molding in an open mold.

The present invention also has a large number of pores having a diameter of 10 μm to 3.5 A and communicating with the outer surface on the inner wall surface of at least the cover plate and the bottom plate, thereby forming an inorganic foam molding material in foam molding. This mold is characterized by being able to discharge only the gas inside the mold to the outside of the mold without causing the liquid phase to flow out.

In the mold of the present invention, a large number of pores having a diameter of 10 μm to 3.5 A and communicating with the outer surface are provided on the inner wall surface of the side wall form of the mold, thereby allowing the foaming of the inorganic foam molding material to occur. It is also possible to more smoothly discharge air within the mold due to volume expansion.

In the mold of the present invention, a water-repellent coating layer is provided on the entire inner wall surface of the mold, so that the mold can be repeatedly removed without forming a water-repellent mold release agent layer after demolding the molded product. The water-repellent coating layer can be formed by tetrafluoroethylene, polypropylene or polyethylene.

[Detailed description of the invention]

To produce an inorganic foam molded article by the molding method of the present invention, a sodium hydroxide solution W# is added to water glass to prepare an aqueous solution of water glass (sodium silicate) 11i.

Separately, a blowing agent mixture is prepared by mixing silicon powder and/or ferrosilicon powder with metal aluminum powder coated with higher fatty acids in order to maintain its activity.

Furthermore, a mold having a large number of pores communicating with the outer surface on the inner wall surface, and a lid plate having a large number of pores communicating with the outer surface on the inner wall surface thereof are also prepared, and further, a mold with a pore diameter of 10 μ to 3·sX is prepared. Prepare a water-resistant porous film with pores,
The entire inner wall surface of the mold is covered with this air-permeable, water-repellent porous film.

An inorganic aggregate such as silica sand grains is mixed into the water glass aqueous solution prepared previously, and the blowing agent mixture prepared previously is further mixed therein to form an inorganic foam molding material liquid.

The inorganic foam molding material liquid is put into a cylindrical mold with an open top, heated to a predetermined temperature, and the inorganic foam molding material liquid is pre-foamed in an open mold method to foam the inorganic foam molding material liquid. Measure the volumetric expansion due to and record this volumetric expansion.

Next, the inorganic foam molding material liquid is poured into the body of the mold prepared in advance, leaving a space at the top corresponding to the volume expansion due to foaming of the inorganic foam molding material liquid measured in the pre-foaming molding. The upper surface is covered with a porous film made of sansui, the above-mentioned lid plate is placed on top of it, the mold is sealed, and the sealed mold is heated to foam and solidify the inorganic foam molding material liquid. . Due to the foaming of the inorganic foam molding material liquid, its volume expands, and the air in the space left on the upper surface inside the mold is discharged to the outside through the pores that communicate with the inner wall surface and the outer surface of the mold, and the mold is sealed. The inside of the molded mold is filled with a foam molded body made from the inorganic foam molding material liquid, and the foam molding is completed. After completion of the process, remove the lid plate of the mold and the water-repellent porous film, remove the foam molded product from the mold body, and remove the water-repellent porous film if it adheres to its surface. , obtain an inorganic foam molded product.

The mold used in the molding method of the present invention is a mold having a pore size of 1 OIJ to 3.5 A in diameter on its inner wall surface and a large number of pores communicating with the outer surface.

In foam molding of an inorganic foam molding material, the volume of the inorganic foam molding material expands due to foaming, so the air in the mold must be exhausted to the outside in an amount equivalent to the volume expansion. Air is discharged from the mold through a large number of pores with diameters of 10μ to 3.5A, which are provided on the inner wall surface of the mold and communicate with the outer surface, and the inside of the mold is It is filled with foam and molded into a predetermined shape. If these pores have a diameter of 10μ or more, the liquid part of the inorganic foam molding material will flow out through the pores, causing the molded product to adhere or stick to the mold material of the mold, preventing demolding. Moreover, it becomes impossible to form the mold into a predetermined shape. In addition, if the pore diameter of these pores becomes smaller than 3.5A, it becomes difficult for air and foaming gas to circulate, and the volume of the space inside the mold decreases, making it impossible for the foam molded product to assume the prescribed shape of the mold. ,
Moreover, the moisture inside the foam molded product cannot be removed, and the molded product may not solidify.

In order to ensure that the volume of the inorganic foam molding material expands inside the mold due to foaming, the inorganic foam molding material leaves a space inside the mold to allow the volume to expand during foaming. and inject it into the mold. The volume of the space required for this can be calculated from the expansion of the volume of the inorganic foam molding material in an open mold by pre-foaming.

When injecting an inorganic foam molding material liquid into a mold, the entire inner wall surface of the mold is made 4 tl aqueous or coated with a water-repellent mold release agent layer, thereby making it easier to release the foam molded product. need to be made possible.

The water glass adhesive has a strong adhesive force, and the volume expansion caused by the foaming of the inorganic foam molding material causes the inorganic foam molding material to be pressed against the inner wall surface of the mold, thereby causing the foam molded product to move inside the mold. This prevents the foam from adhering to the wall surface and facilitates demolding of the foam molded product. This water-repellent mold release layer is formed by being fixed to the entire inner wall surface of the mold, thereby making it possible to use the mold repeatedly.
It is also possible to coat the inner wall surface of the mold with .mu.~3.5A). In the case of forming a mold release agent layer using this water-repellent porous film, the mold release layer is often removed from the inner wall surface of the mold together with the foamed molded product, which makes it difficult to use the mold repeatedly. In this case, it is necessary to form the R-type layer again. The coating of the water-repellent mold agent layer on the inner wall surface of the mold can be formed by coating the inner wall surface of the mold with a dispersion of fine particles of the Il agent and drying. In this case, the voids between the fine particles of the mu agent form pores for air passage inside the mold.

The range of choices for the shape of the foamed molded product can be expanded by using a split mold that can be sealed and by using the split mold.

The pores in the mold can be formed by molding and sintering fine metal or ceramic particles in the mold. In this sintering process, fine metal or ceramic particles are partially fused at their mutual contact areas to form a mold, but the voids between the fine particles remain even when the metal or ceramic particles are closest packed. , exists inside the body of the mold, and these voids remain even after sintering to form pores in the inner wall surface of the mold.

The IW type agent layer can be formed on the inner wall surface of the mold by applying tetrafluoroethylene. A film of tetrafluoroethylene polymer, a polyethylene film or a polypropylene film can also be used as the inner wall surface of the mold.

In the following, the invention will be explained in more detail by means of examples.

Example 1 (1) Production of a mold Spherical particles of gunmetal with an average particle diameter of 25 μm were mixed with an aqueous methyl cellulose solution (binder) to make a paste material, and this was used as a mold (90 sul (long) x 65 B (11
) x 10fl (deep)] and move it vertically.
It was pressurized at MPa and formed into a plate shape. This plate-shaped molded body was placed in an electric furnace and sintered at 785°C to form a gunmetal particle sintered plate (90su+(length)×65as+(1m)).
x 10 m (thickness)] was obtained. This gunmetal particle tattoo sintered plate has a large number of diameters of 10 μm that communicate with the top surface of the plate.
A communication hole was formed.

In addition to this, side wall formwork made of gunmetal (90M (outer wall length)
65su* (outer wall width) x 75m (height), 70 decoys (inner wall length) x 45m 111 (inner wall width)] were manufactured.

On the entire surface of the gunmetal particle sintered plate, a mold release agent [Mold Spud MR-520 (trade name) manufactured by Asahi Glass Co., Ltd.] was sprayed to a thickness of 5 μm, and then A side wall form spray-coated with the above-mentioned tetrafluoroethylene fine particle W type agent to a thickness of 511 mm was placed on the entire wall surface of the above-mentioned gunmetal side wall form to form a mold body.

Separately, the above-mentioned 4
A fluorinated polyethylene fine particle mold release agent was spray applied to a thickness of 5 μm, and this was used as a mold lid plate.

(2) Preparation of molding material mixture Dissolve 8.5 Il of sodium hydroxide in 50 g of water, add water glass (Jl, No. 53 product, StO content = 29.1%)
(weight)] to prepare a water glass solution, and to this, silica sand powder [200-325 mesh: 56% (weight), 3
25 mesh bath = 44% (weight)] 300 g and aluminum hydroxide powder (300 mesh bath) 50Ii
Add admixture and add 3g of metallic aluminum powder (average particle size: 32μ, coated with stearic acid)
and silicon powder [100 mesh bath, purity: 98%
(weight)] 159 of a blowing agent was added to prepare a molding material mixture.

(3) Pre-foaming molding of the molding material mixture After thoroughly stirring the molding material mixture, mold it into a cylindrical mold made of cardboard (30 + Im (inner diameter) xttom (height)).
was injected to a depth of 50 m + 11 m, heated to 40°C without covering the mold, and allowed to foam freely, and then
After curing in an oven at 0° C., the mold was broken and the height of the molded product was measured.

The height of the molded product was 65 mm, and its volume had expanded 1.3 times.

(4) Foam molding of stamp material mixture The molding material mixture was injected into the body of the mold to a depth of 60 mm, and the lid plate of the mold was placed on top of it. The inside of the mold has a height due to volume expansion due to foaming of the molding material mixture! A space of 01111 was left. Aluminum perforated plates above and below the mold [hole diameter: 3
90 m (length) x 65 m (width) I did it.

After the molded product has foamed and solidified, loosen the vise and remove it. After removing the perforated aluminum plate, the lid plate and the bottom plate of the mold, the silica sand powder aggregate is extracted from the inner space of the side wall formwork of the mold. took out the foamed molded product adhered with water glass.

The product was taken out smoothly, and the shape of the foamed product conformed to that of the mold.

Example 2 (1) Production of mold Soft! 1lls: Board [Insulation board A grade (product name), 90 chu (length) X 65B (@) X
t.

Two schools were prepared. This soft m-joint plate had a large number of holes communicating from its upper surface to its lower surface.

In addition to this, side wall formwork made of gunmetal (90su + (outer wall length) x 65fi (external 12W) x 75 m (height),
701 (inner wall length) x 45su+ (inner wall width)] was manufactured.

A polytetrafluoroethylene porous film [Boretex Film (trade name) manufactured by Japan Boretex Co., Ltd., pore size: 0.4μ] was placed on the top surface of the above-mentioned soft l@fiber joint plate, and the inner wall surface was covered with the above-mentioned The aforementioned gun metal side wall form coated with a porous film of tetrafluoroethylene was placed to serve as the main body of the mold.

(2) Foam molding of the molding material mixture The molding material mixture of Example 1 was added to the body of the mold.
Inject to a depth of 60 mm and place the above 4 on the main body of the mold.
A fluorinated ethylene porous film was covered, and the above-mentioned soft fiberboard was placed thereon. Inside the mold there is a height of 1011111 for volume expansion due to foaming of the molding material mixture.
space was left.

This mold was inserted into two aluminum perforated plates [pore diameter 3”
90su+ (length) x 65fl (width) xtosoa (
After fixing the upper and lower surfaces between the vises, place the mold in a 70°C oven and heat it.
Foam molding was performed.

After the molded product has foamed and solidified, loosen the vise and remove it. After removing the perforated aluminum plate, mold mounting plate, and bottom plate, silica sand powder is removed from the inner space of the side wall formwork of the mold by water glass. The adhered foam molded product was taken out.

Although the polytetrafluoroethylene porous film was attached to the foamed molded product, it was removed smoothly. The material was exactly as shown in the mold.

〔Effect of the invention〕

A closed mold can be used for foam molding of an inorganic foam molding material, thereby making it possible to produce a foam molded product with accurate dimensions.

The foamed molded article can be easily and easily released from the mold.

Claims (12)

[Claims] (1) In foam molding of an inorganic foam molding material consisting of aggregate, water glass, and a foaming agent, the inner wall surface has a pore size of 10 μ to 3.5 Å in diameter, and the closed mold has a large number of pores communicating with the outer surface. A method for foam molding an inorganic material, characterized by using a mold as a mold. (2) A method for foam molding an inorganic material according to claim 1, wherein the aggregate is silica sand powder, and the foaming agent is metal aluminum powder, silicon powder, or ferrosilicon powder. . (3) The foam molding is performed with a water-repellent and mold-releasing film interposed between the inorganic foam molding material and the inner wall surface of the mold. The method for foam molding an inorganic material according to item 2. (4) The water-repellent and mold-releasing film has a diameter of 10 μm or more.
4. The method of foam molding an inorganic material according to claim 3, wherein the film is a porous film of tetrafluoroethylene, polypropylene, or polyethylene having air holes with a pore diameter of 3.5 Å. (5) The method for foam molding an inorganic material according to claim 1 or 2, wherein the mold has a water-repellent mold release agent layer formed on its inner wall surface. (6) The method for foam molding an inorganic material according to claim 5, wherein the water-repellent mold release agent layer is a porous coating layer of tetrafluoroethylene. (7) A claim characterized in that the foam molding is performed while filling the mold with an inorganic foam molding material that leaves a space corresponding to the volume expansion due to foaming of the inorganic foam molding material. A method for foam molding an inorganic material according to any one of items 1 to 6. (8) Volume expansion due to foaming of the inorganic foam molding material
Claim 7, characterized in that the detection is performed by pre-foam molding in an open mold of an inorganic foam molding material.
A method for foam molding an inorganic material as described in Section 1. (9) A closed mold, characterized in that at least its lid plate and inner wall surface have a large number of pores having a diameter of 10 μm to 3.5 Å and communicating with the outer surface. (10) Claim 9, characterized in that a large number of pores having a diameter of 10 μm to 3.5 Å and communicating with the outer surface are provided on the inner wall surface of the side wall formwork of the mold. The mold described in section. (11) Claim 9, characterized in that the entire inner wall of the mold is coated with a water-repellent mold release agent layer.
The mold according to item 1 or item 10. (12) The mold according to claim 11, wherein the water-repellent mold release agent layer is made of tetrafluoroethylene.