JPH10268755A - Lightweight clay - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain lightweight clay which may be sufficiently reduced in weight, is fast in the number of days for drying and is low in a shrinkage rate by consisting microparticle stock of glass microhollow spheres formed of glass as main stock and forming the glass microhollow spheres of spheres of a specific grain size including gas. SOLUTION: The microparticle stock of the lightweight clay prepd. by using the microparticle stock as an essential component and including glue, etc., therein consists of the glass microhollow spheres formed of the glass as the main stock. The glass microhollow spheres comprise the spheres which contain the gas and are sized 1 to 200 microns in the grain size. The glass microhollow spheres are formed of soda lime borosilicate glass which is insoluble in water and solvents and is chemically stable as a main raw material. The glue plays the role for bonding the glass microhollow spheres and plays the role for solidifying the spheres after molding. The examples of the glue include carboxymethylcellulose, polyvinyl alcohol, starch, methyl cellulose, hydroxyethyl cellulose, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to improvement of clay, and more particularly, to improvement of lightweight clay which can be easily transported.

[0002]

2. Description of the Related Art Clays used for school teaching materials and arts and crafts are not easily transported. Therefore, the weight of clay has been conventionally reduced. As a conventional lightweight clay, for example, one having a shirasu balloon as a main component is known. However, those containing this shirasu balloon as a main component contain many heavy inorganic substances such as calcium carbonate and talc,
In addition, the particles are easily pulverized and easily pulverized during production, and furthermore, water is easily absorbed, and it is difficult to achieve a sufficient weight reduction. On the other hand, for example, Japanese Patent Publication No. 6-70734 proposes a lighter weight clay. This lightweight clay is mainly composed of a fine particle material composed of minute hollow spheres formed of a copolymer resin containing at least one component of acrylonitrile or vinylidene chloride.
However, although this lightweight clay is good in terms of weight reduction, it has a problem that it is difficult to incinerate a large amount of clay at a time because harmful gas is generated at the time of incineration because it is mainly composed of organic matter. . In addition, in this lightweight clay, a powdery substance adheres to a hand at the time of molding, and the hand becomes white. In addition, the above-mentioned conventional shirasu balloon as a main component (hereinafter referred to as shirasu balloon-based clay) or a fine particle material composed of micro hollow spheres formed from a copolymer resin of Japanese Patent Publication No. 6-70734 as a main component. (Hereinafter referred to as a copolymer resin-based clay) have a long drying time. In addition, there is a problem that the shrinkage ratio is large, so that the clay is warped after the molding and the shape formed into a predetermined shape may be deformed. Furthermore, after modeling and drying the clay, when coloring and finishing with paint, etc., if the clay is white, it can be beautifully finished with paint, etc. ing. Further, although the copolymer resin-based clay has a white color, if the clay is allowed to stand for about 20 days after molding, yellowing occurs. Therefore, these conventional products have a problem that it is difficult to finish finely by coloring after drying.

[0003]

DISCLOSURE OF THE INVENTION The present invention has been proposed in view of the above circumstances, and has as its object to provide a lightweight clay which is sufficiently light in weight, has a fast drying time, and has a small shrinkage. Aim.

[0004]

The present invention solves the above problems by providing a lightweight clay having the following features. The present invention relates to a lightweight clay containing a fine-grained material as a main component and containing a sizing agent and the like, wherein the fine-grained material is made of glass micro-hollow spheres formed of glass as a main material. Has a particle size of 1
It is a lightweight clay consisting of a size of ~ 200 microns.

[0005] The fine grain material used in the present invention is made of glass micro hollow spheres. These glass micro hollow spheres are made from chemically stable soda-lime borosilicate glass, which is insoluble in water and solvents, and have been manufactured as so-called glass balloons. It is used for various applications such as wall repair for medical use and various medical products, and can be used. The hollow glass microspheres used in the present invention have a particle size of 1 to 200 microns, exhibit white color (visually), a water content of 0.5 wt% or less, and a true specific gravity of 0.1 to 0. 0.6 g / c. c. It is about. The pressure resistance of the glass micro hollow sphere used in the present embodiment is 750 psi (1 psi = 6.90 × 10 ^3).
N, 1 kgf = 9.807 N / cm ² ), and the average value of the residual ratio (VOL%) when pressurized is about 90 to 92. In addition, the residual ratio (VOL
%) Is calculated from the change in the true specific gravity when a sample mixed with talc is pressurized to a measurement pressure with dry nitrogen gas, but is not limited to this range and can be used.

[0006] A glue,
The lightweight clay of the present invention can be obtained by blending fiber powder, water, and a small amount of a preservative.

[0007] The compounding amount of the glass micro hollow spheres is as follows.
30 to 70 parts by weight are preferred. If the amount is less than 30 parts by weight, the weight cannot be reduced so much. On the other hand, if the amount is more than 70 parts by weight, the shrinkage and cracking after molding become large, and the viscosity decreases, and the core material used when molding is used. Adhesion is reduced.

[0008] The sizing agent plays a role of binding the glass micro hollow spheres and a role of solidifying after molding. As this paste, carboxymethyl cellulose (CMC), poval, starch, methyl cellulose,
Ethyl cellulose, hydroxyethyl cellulose and the like can be mentioned, and one of them or two or more selected from them can be used.

The amount of the paste is preferably 10 to 50 parts by weight. If the amount is less than 10 parts by weight, the sculpture will be reduced. On the other hand, when the amount is 50 parts by weight or more, the shrinkage after the molding becomes large, and it tends to adhere to the hand during the molding.

[0010] The fiber powder plays a role of binding the glass micro hollow spheres, and also plays a role of preventing shrinkage and cracking after molding, and the like. 3% moisture 85%), synthetic pulp (2 mm, 0.3 mm dried product), powdered starch and the like.

The amount of the fiber powder is preferably 30 to 60 parts by weight. If the amount is less than 30 parts by weight, shrinkage and cracking after molding will increase. On the other hand, when the amount is more than 60 parts by weight, the amount of water becomes too large and the weight reduction is impaired, and the molding becomes difficult.

The amount of water to be added is preferably 200 to 400 parts by weight based on the above-mentioned glass micro hollow spheres, sizing agent and fiber powder. If it is less than 200 parts by weight, it is hard, lacks sculpture, and becomes difficult to form. On the other hand, if it is 400 parts by weight or more, it becomes too soft and sticky, so that it easily adheres to hands.

The preservative is not particularly limited as long as it is safe. In addition, other components, for example, a colorant, may be blended in addition to the above components, and may be appropriately changed.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The lightweight clay of the present invention will be specifically described below with reference to numerical values. 50 parts by weight of glass micro hollow spheres, 30 parts by weight of carboxymethylcellulose (CMC) as a sizing agent, and 40 parts by weight of synthetic pulp as a fiber powder were put into a mixer and wet-stirred and mixed. Thereafter, 250 parts by weight of water and a small amount of a preservative were added, and the mixture was stirred and wet-mixed to obtain a lightweight clay of the present invention.

Since the obtained lightweight clay is mainly composed of glass micro hollow spheres containing gas, it is about half the weight of the conventional shirasu balloon-based clay, and the weight is reduced. In addition, in the conventional copolymer resin clay, as described above, the powdery material adheres to the hand during molding, and the hand becomes white, but in the lightweight clay of the present invention, it may adhere to the hand during molding. There was none. This is because, whereas the conventional copolymer resin clay is organic, the glass micro hollow spheres, which are the main component of the present application, are inorganic, and the familiarity with the sizing agent and fiber powder is better for organic than for organic. Probably because there is. Furthermore, since it is inorganic, it does not generate harmful gas when burned, and can be incinerated easily in a large amount in a normal incinerator. On the other hand, the obtained lightweight clay has a white color,
In addition, it remains white without yellowing even after being left for 30 days after molding, and its surface is smoother than conventional shirasu balloon-based clay or copolymer resin-based clay, and is colored with paint etc. I was able to finish it beautifully.

In addition, a comparative test on the drying properties and shrinkage properties of the obtained lightweight clay of the present invention, shirasu balloon-based clay, and copolymer resin-based clay was conducted.
It is described in Table 1 below. In this comparative test, each clay was tested for thickness 3
It was stretched into a plate of mm and cut into 10 cm squares to form test specimens, which were performed for each item. In the comparative test for shrinkage, the shrinkage of the test specimen was measured on the 10th day after the production, and the warpage was measured with respect to one end of the test specimen on the 10th day after the production as shown in Table 1. The measurement was performed by measuring the amount of floating on the other end side due to the above. This test was performed at room temperature of 10 ° C. and humidity of 50%.

[0017]

[Table 1]

As shown in Table 1, the lightweight clay of the present invention was dried in a shorter time than the shirasu balloon clay and the copolymer resin clay. Also, regarding shrinkage, the lightweight clay of the present invention has a smaller shrinkage ratio than shirasu balloon-based clay or copolymer resin-based clay, whereas shirasu balloon-based clay or copolymerized resin-based clay warps, The lightweight clay of the present invention hardly warped. From the above test results, the lightweight clay of the present invention is easy to dry after molding,
In addition, deformation after molding can be prevented, and the shape as molded can be maintained.

[0019]

As described above, the present invention is light in weight, easy to dry after molding and has a small shrinkage ratio as compared with conventional products, and can prevent deformation after molding, and can be molded as it is. Shape can be maintained. Further, at the time of molding, there is no possibility that the clay component adheres to the hand. Furthermore, the white color can be maintained even after standing after being formed, and the surface is smooth and can be finely finished by coloring of paint or the like. In addition, the glass micro hollow sphere which is the main component,
Since it is inorganic, it does not generate harmful gases when burned, and can be easily incinerated in a large amount in a normal incinerator.

Claims (1)

[Claims] 1. A lightweight clay comprising a fine particle material as a main component and a sizing agent or the like, wherein the fine particle material comprises glass fine hollow spheres formed of glass as a main material. A lightweight clay, wherein the sphere is made of a gas having a particle diameter of 1 to 200 microns.