JPH01203253A - Production of cement product - Google Patents

Abstract

PURPOSE:To obtain a cement product which is inexpensive, has excellent mechanical strength, wear resistance, watertightness, chemical resistance, mass productivity, etc., and is adequate for a press molding tool, etc., by mixing cement and thermosetting resin, packing the mixture in the molding tool and curing the same. CONSTITUTION:The cement (e.g.: Portland cement, blast furnace cement) which is an inorg. binder adhesive agent and the thermosetting resin (e.g.: epoxy resin, melamine resin) are mixed to produce a material mixture 3. This material mixture 3 is packed into the molding tool 1 and a press plate 4 is put therein and fixed, then the mixture is cured, by which the cement product T is obtd. Since the cement is solidified and cured by the thermosetting resin, the cement product T in which the structure is tightly bonded is obtd. In addition, the curing time which is heretofore dependent only on a hydration reaction is shortened to the curing time of the thermosetting resin and the cement product is produced in a short period of time.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for manufacturing various cement products made from cement as a raw material, such as a cement mold used instead of a mold.

[Conventional technology]

Molding machines such as press molding machines and injection molding machines usually use molds made from various types of mold steel, but the cutting process of these molds is troublesome and they are very expensive. Therefore, as high-mix, low-volume production is progressing these days, the proportion of total mold costs in the total manufacturing price of a product has increased, making it uneconomical, and manufacturing delivery times are long, which has a large impact on product manufacturing. There was a problem.

Therefore, manufacturing costs are lower than traditional metal molds,
Another idea was to use cement molds made of cement concrete, which can be manufactured in a short construction period.

To explain an example of conventional cement mold manufacturing using a sheet metal press mold as an example, the first step in manufacturing is to create a base mold (
model) in a wooden core box, then
After applying a mold release agent to the surface of the base mold and the inner surface of the core box, a cement paste made by dissolving cement in water is poured into the core box, and after solidifying, leveling and squeezing the top surface of the core box, A cement mold made of cement concrete was made by removing the core box and releasing it from the base mold.

In addition, by inserting alkali-resistant glass, various types of inorganic or organic ultrafine particles, or fine aggregates such as metal fibers and reinforcing bars into the above-mentioned cement, or by impregnating it with resin or heat-curing it, Reinforcement of cement molds was also done.

Incidentally, the manufacturing method using cement concrete described above can be similarly carried out when manufacturing other cement products.

Furthermore, instead of this cement concrete, so-called resin concrete, in which rhusium carbonate, sand, and gravel are hardened with a thermosetting resin, is sometimes used.

[Problem to be solved by the invention]

However, products made of cement concrete, including cement molds with one or more configurations, do not have sufficient mechanical strength, abrasion resistance, or chemical resistance due to the cement used, and also have high porosity and fluid resistance. Since the watertightness that prevents the inflow and outflow of water is low, the surface of the product may become deformed and worn if used repeatedly, and the resistance to freezing and thawing is low. Therefore, especially in the case of cement type The number of times it can be used is extremely small, so it can only be used for molding prototypes, etc., and cannot be used as a regular mold in place of a mold, and it takes a long time to manufacture due to the long solidification time. was there.

Furthermore, in the case of the products made of resin concrete mentioned above, various properties such as strength, abrasion resistance, chemical resistance, and watertightness are similarly insufficient, and products with excellent mechanical properties are not provided. Under the current circumstances, it was completely impossible to manufacture a wooden mold to replace the mold.

Therefore, the technical problem of the present invention is to manufacture cement products in a short time that have excellent mechanical strength and wear resistance and can be used as main molds instead of molds in the case of cement molds. There is a particular thing.

[Means to solve the problem]

The measures taken in the present invention to solve the above technical problems are as follows.

Filling a mold with a mixture of cement, which is an inorganic bonding agent, and thermosetting resin and allowing it to harden.

However, cement here means any of various mixed cements such as blast furnace cement or silica cement, in addition to commonly used Portland cement, and thermosetting resin refers to epoxy resin. It refers to various resins such as melamine resin, phenol resin, and unsaturated polyester resin, which have mechanical strength, abrasion resistance, and chemical resistance, and in which a curing agent is mixed in advance.

[Effect]

The above means works as follows.

The above elements are achieved by solidifying and hardening the cement with a thermosetting resin, which creates a tightly bonded structure that provides excellent mechanical strength and abrasion resistance, as well as watertightness and chemical resistance. In addition to being able to manufacture cement products, the curing time that previously depended only on the hydration reaction (approximately 60% in one month) has been reduced to the curing time of thermosetting resin (approximately 1 to 36 hours).
This makes it possible to manufacture the above cement products in a short time.

As described above, the above-mentioned technical problem can be solved by the above-mentioned means, and the problems of the conventional technology can be solved.

〔Example〕

Hereinafter, preferred embodiments of the method for manufacturing cement products according to the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a sectional view showing a state in which a base mold 2 is fixed on a bottom hole 1a of a mold, generally indicated by reference numeral 1, and a second
The figure shows that the inside of the mold 1 shown in FIG. It is a sectional view showing a state where it is covered and fixed.

The cement constituting the mixed material 3 above is as follows.

In addition to general Portland cement, various mixed cements such as blast furnace cement or silica cement are used, and thermosetting resins include epoxy resin, melamine resin, phenol resin, Unsaturated polyester resin etc. are used, and cement 10
Based on 0 parts by weight.

The mixed material 3 is formed by mixing 12 to 35 parts by weight of thermosetting resin at normal temperature (room temperature). Further, a curing agent such as an amine is mixed in advance with the thermosetting resin.

If the mixing ratio of the thermosetting resin is 12 parts by weight or less, the cement will not harden sufficiently and the desired strength, wear resistance, and watertightness will not be obtained unless pressurized. Furthermore, it has been found that when the mixing ratio is 35 parts by weight or more, the proportion occupied by the resin increases, and then it solidifies and cannot exhibit sufficient strength unless heated. Therefore, the mixing amount of the thermosetting resin is 12 to 12, which can be solidified at room temperature and pressure.
It has been found that 35 parts by weight is optimal for work.

Furthermore, the cement and thermosetting resin mixed in the above ratio cause a chemical reaction between the alkaline components of the cement such as potassium oxide and sodium oxide Na2O, and the amines of the thermosetting resin, and further This is because the adhesive reaction of cement is compounded.

It solidifies extremely strongly within the mold 1.

Once the mixed material 3 has hardened (solidified), the mold 1 is removed and released from the base mold 2 as shown in Figure 3, thereby producing a cement product such as a cement mold generally indicated by the symbol T. However, since the curing time of the mixed material 3 is the curing time of the thermosetting resin used (approximately 1 to 36 hours), it is shorter than the curing time of conventional cement products that depend only on hydration reactions. is also much shorter, thus making it possible to produce the cement product T in an extremely short time.

Furthermore, while the compressive strength of the conventional cement product was 415 kgf/cJ after curing for 28 days, the compressive strength of the cement product T manufactured by the above invention was 50 kgf/cJ after curing for 3 days.
It has been found through experiments that a durable product can be manufactured in a short period of time with 0 kg f /ad.

Furthermore, while the bending strength of conventional cement products was 70 kg f /afT after 28 days of curing, the cement product T manufactured by the present invention had a bending strength of 200 kg f /afT after 3 days of curing.
It was found that the cement product T produced according to the present invention has a strength approximately three times as high as g f /d, and is equivalent to the SS material in terms of hardness.

In addition, in the balance machine test and the bending test, the cement product T manufactured by the present invention was approximately 3 times higher than the conventional cement product.
It was also found to be twice as strong and equally excellent in chemical resistance.

〔effect〕

Since the method for producing a cement product according to the present invention is as described above, the cement product produced according to the present invention is produced by hardening cement into a dense structure with a thermosetting resin and using cement concrete or resin concrete. It has far superior mechanical strength and abrasion resistance, as well as watertightness and chemical resistance, compared to conventional products manufactured using conventional methods, and has the advantage of being extremely easy to manufacture in a short period of time and at low cost. It has the advantage of reducing the production cost of small-volume products and safely performing high-mix, low-volume production. Combined with the fact that it is simple in configuration and easy to implement, it is especially suitable for press forming. Molds, injection molds, vacuum molds,
The foam is useful for manufacturing various cement molds such as FRP molds and RIM molds, and other various cement products such as casting models and building materials.

[Brief explanation of the drawing]

FIGS. 1, 2, and 3 are cross-sectional views sequentially illustrating the state in which a cement product is manufactured by implementing the manufacturing method of the present invention. 1 is a mold, 2 is a base mold, 3 is a mixed material of cement and thermosetting resin, and T is a cement product manufactured according to the present invention. Patent applicant Resin Machinery Co., Ltd.

Claims (1)

[Claims] A method for producing a cement product, which comprises filling a mold with a mixed material of cement, which is an inorganic bonding adhesive, and a thermosetting resin, and curing the mixture.