DE2021085A1 - Cold setting clay - Google Patents

Description

"Cold setting clay"

The invention relates to molding compositions and in particular to Cold-setting, wet, malleable mixtures consisting of fillers and synthetic resins. The invention further relates to a method for producing objects from these molding compositions and to packaged objects which contain these molding compositions.

It is known that the currently available materials have some disadvantages for modeling and molding. One type of cold setting clay includes one small amount of a hydrophilic binder, the water- " glass or a colloid like dextran. Although the Shrinkage is very low, is pressed or modeled Very fragile item if dropped

Patent attorneys Dipl.-Ing. Martin Licht, DipI.-VVrrtsch.-Ing. Axel Hansann, Dipl.-Phys. Sebastian Herrmann ". 2 -

OppenauerBOroj PATENTANWALT, DR. REINH.0LJ3 SCHMIDT

or triggered in another way. Other Modeling materials are made up of flour «water, salt and a small amount of a hydrocarbon such as kerosene. This material can easily be molded when wet. However, there is significant shrinkage of this material on drying and cracked, cracked, and wavy copies of the article are produced when molded when wet.

The invention was the. The task is based on a novel, wet, cold-setting, self-hardening modeling compound that can be easily deformed when wet, but self-cures in air and forms a very shock-resistant, water-resistant molded article. Another object of the invention was to provide of a cold-setting modeling clay, which after drying shows a strong resistance to physical influences and becomes soft when exposed to water.

This object is achieved according to the invention by the development of an improved modeling molding compound or a compression molding compound, which consists of an aqueous dispersion of about 20 to kO parts by weight of water, 7.5 to 25 parts by weight of a water-dispersible, self-curing organic resin and the remainder essentially consists of inert fillers consisting of individual parts that have a high affinity and adhesion to the above-mentioned resin.

The molding compound according to the invention is in a wet, plastically deformable state and can be irreversibly converted into a dry, hard, solid state, internally the compound shows a very good resistance to impacts and the like and likewise

- 3 - old waster not softened on contact;

The molding compound according to the invention is produced, however Resins and fillers are dispersed in water to form a deformable and self-supporting mass, discarded portions of the mass being placed in water-vapor-impermeable containers and the containers being sealed. Shaped or pressed items are produced »by the deformable mass in the wet state is brought into the fora, the mass is kept in a wet state while it is processed and then becomes a hard, very shock-resistant object is dried and tied. The dried and hardened object shows excellent resistance to softening and dissolution when in contact with water.

The molding composition according to the invention is in the following Description explained in detail.

Although the components of the molding composition according to the invention in In terms of type and physical condition, they vary considerably they must be within the suggested areas lying in order to have the desired functions. The resin or the plastic must have a stable dispersion in the water make up and dry and within a practical time set or harden to form a continuous binder phase that has good adhesion and affinity to has the filler particles dispersed therein so that the finished article has good hardness, rigidity and impact resistance. The resin phase must essentially not be influenced by water when it is in has reached the dried and hardened state.

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Synthetic resins that enhance these properties must be in a Quantity of 7.5 bit 25 parts by weight must be available. Are If less than 7.5 parts by weight of resin is present, the finished article will break easily if it comes out of a Dropped height of about 75 ca onto a hard surface will. If the resin content is over 25 parts by weight, then ■ use the drying time to be extended in a unnecessary way and the hardness and rigidity of the mass decreases. An optimal amount of the resin within the stated range is based on the particle size of the Filler. With a filler that has a finer particle size and therefore a larger surface area of the Forming filler, the resin content can usually be higher.

It was found that an organic synthetic resin which is formed from synthetic, unsaturated monomers is suitable for the molding compound according to the invention. The resin is preferably made from prepolymerized diene elastomers which are present in an amount of from 10 to 20 parts by weight. For example, butadiene copolymers, such as styrene-butadiene copolymers, which have 15 to 85 % styrene and preferably 45 to 75% styrene, can be used as diene elastomers.

The resin is normally used as an emulsified dispersion in water. The total water content of the mixture • Ought to be kept within 20 to 40 parts by weight. The water content can be reduced within this range as the size of the filler particles increases and can be increased within this range in order to improve the flowability and the softness or suppleness to improve the molding compound. Molding compounds with the best

009846/1285

Balance of overall properties contain 25 to 35 parts by weight of water.

The term "prepolymerized" means that a resin is used, in which the content of free monomer residues is very low and that can only be converted into a hardened state by drying and no reactions and conversions for the purpose of hardening and cross-linking are necessary. It could be determined »that polymers that are hardened or implemented in another way need to be, are not necessary to the molding compounds according to the invention to give the necessary strength. In addition, the styrene-butadiene-latex polymer is wet Less sticky condition. Others dispersible in water Polymers, such as the homopolymers or copolymers of vinyl acetate or acrylic polymers, such as for example 2-ethyl hexaorylate can also be used, but give a hardened end product which is not as stable to water.

A wide variety of filler types can be used for the molding compositions according to the invention, for example Mineral fillers of clay, such as top bentonite, Kaolin, pottery clay, silicon oxide, crushed rock or ceramic brick dust. Various other softer fillers can also be used, such as wood flour, sawdust, wood dust, shredded rags, paper, glass roving, labest and the like. However, these absorb porous materials with the lighter weight significant amounts of water and when drying occurs a greater shrinkage and Fragility of the mass. Therefore, these ftillsieffarten should only be present in a small amount. Preferred the mineral fillers should be used.

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Furthermore, it was found that an increased plasticity and lubricity or slipperiness is obtained if 15 to 50 % are used in the filler mixture. The plasticity also increases if the particles of filler are kept below 50 microns and preferably below 25 microns in the average particle size distribution. The resin and filler are dispersed in an amount of 20 to 40 parts of water. If the water content is decreased below 20 parts, processing of the mass in the dry state becomes quite difficult. With a water content of over 40 parts, the wet mass is too liquid to be held in a molded, pressed or modeled form.

The properties of the cold-setting modeling compounds according to the invention can be changed to increase or decrease the plasticity by adding the amount and the type of resin, water or pigment can be varied.

In the following examples, preferred embodiments of the molding compositions according to the invention are explained in detail.

EXAMPLE I

The molding composition according to the invention contains the following components

Ingredient · parts by weight Capsule clay-potters clay (you »openingι0,044 am) 33 1/3 Silicon oxide (sieve opening 0.044 mm) 33 i / 3 PWW Talk (Siefeuffmuig 0.074 mm) 33 1/3 StTr * l-Bttta * i # * latex (33 l / 3 Jt Fsst) 50

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The lexex became dea Tob, dea silicon oxide and de talk added with stirring until the fillers were completely and homogeneously dispersed ia latex. The crowd became then placed in a metal container and closed with a lid. Some of the mass was later removed and pressed onto a metal plate, which has a hollow space » of 0.635 ■■ and the fon of an animal. The mass that was printed in was removed and left in Air dry at Ziaaerteaperatur. After an hour the treated foraaasse was hard enough to be treated without the fora being able to change. After about 15 hours the treated Foraaasse was fully hardened and allowed to be handled or dropped in any way without breaking went and damage to the surface could be determined.

The foruasse described above ie Example I according to the The invention is particularly suitable for press molding.

EXAMPLE II

The foraaasse described in this example after the The invention is particularly suitable for modeling and has the following components:

Components (Sieve opening: 0.037 aa) Parts by weight Ibex Benton! Tton (Sieve opening: Q, Okk aa) 50 CWF kaolin clay (Sieve opening: 0.037 aa) 50 Talk 35 water (33 1/3 lb. solids) 50 Styrene-butadiene latex 62

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The ingredients were mixed by diluting the latex with the water and adding the fillers to the diluted latex. Ea was stirred until a good dispersion was obtained. The mass was solid and cohesive when wet. The molding composition according to the invention was placed in a three-sided envelope which consisted of an aluminum foil coated with a polyethylene film. The open side of the envelope was closed by heating with an iron to form a fused seam. At a later point in time, part of the molding compound was removed and it was found that it was feet and cohesive in the wet country of tension and could be easily handled and shaped without it sticking to the hands or the modeling tools and still retained the pressed-in shape of the Pattern retained. An object with a complicated configuration was molded by quickly modeling hands and modeling tools. During the deformation, water was placed on the surface of the article in order to keep the molding compound in a wet and soft state until the final configuration was completed. You read! then dry the object and after an hour it had become hard. After 10 to 20 hours, the article was fully set and cured and did not break when dropped onto a hard surface from a height of about 75 cm.

EXAMPLE III

The following molding compound according to the invention is particularly suitable for compression molding and modeling. The crowd • consists of the following components:

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Ingredients by weight Talc (PWW degree) (sieve opening 0.07 * mm) 20 Pottery clay (sieve opening: 0.037 «■) 14 Silicon oxide (sieve opening: 0.044 mm) 6 Styrene butadiene latex (33 1 * pesticides) 50

The molding compound was hard and cohesive and showed good plasticity and deformability when wet and could can still be dried to a hard and rigid object with a high impact resistance. The one from this The article produced by the molding compound showed no cracks or corrugations. The object was immersed in water for two days immersed and it could not be found that the object softened or dissolved, although a very slight swelling occurred "

In the following examples IV to VI molding compositions according to the invention old described different amounts of resin.

EXAMPLE IV

The molding compound contained a good dispersion of the following components:

Ingredients by weight

Kaolex D-6 (kaolin clay) (sieve opening: 0.044 times) styrene butadiene latex (33 %)

EXAMPLE V

The molding compound contained a good dispersion of the following components:

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Ingredients by weight

Snow-Cal (Calif. Primärton) (sieve opening: 0.0Vi µm) 50 Talc (sieve opening: 0.074 tat) 50

Styrene Butadiene Latex (33 % solids) 23 EXAMPLE VI

The molding compound contained a good dispersion of the following components:

Ingredients by weight

CWF (kaolin clay) (sieve opening: 0.044 mm) 125 styrene butadiene latex (33 %) 48

The styrene-butadiene latex used in the above examples contained 66 % styrene and 34 % butadiene (DOW 460 from DOY CHEMICAL COMPANY). If the amount of styrene added is increased, the plasticity increases and therefore the strength of the resin and the finish increases. If, on the other hand, the butadiene content is increased, the elastomeric properties of the resin and the elasticity and softness of the mixture do not increase.

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Claims (14)

-Ii- Dr.La/LU PATENT CLAIMS X ü Molding compounds that are irreversibly transformed from a wet, plastic, deformable state into a dry, hard, rigid state can be converted and a high impact resistance and good insensitivity to Show water, characterized by an aqueous dispersion consisting of 20 to 40 parts by weight of water, 7.5 to 25 parts by weight of a water-dispersible, self-curing organic resin and the remainder of essentially inert particulate fillers with high affinity and adhesion to the resin. 2. Molding compositions according to claim 1, characterized in that the dispersion is 25 to 35 parts of water, 10 to 20 parts a prepolymerized resin synthesized from unsaturated monomers and composed of discrete mineral fillers which an average particle size distribution below Own 50 microns. 3. Molding compositions according to claim 2, characterized in that the resin is a diene elastomer. 4. Molding compositions according to claim 3t, characterized in that the elastomer is a styrene-butadiene copolymer with 15 to 85 % styrene. 5. Molding compositions according to claim 4, characterized in that the styrene content is 45 to 75 % . 009846/1285 " ¹² " 6. Molding compositions according to claim 2, characterized in that the mineral fillers have an average Have particle size below 25 microns and at least a component of talc, pottery clay, silicon oxide, bentonite or kaolin. 7. Molding compositions according to claim 6, characterized in that the filler consists of 15 to 50 % pottery clay. 8. Molding compositions according to claim ⁹ 1, characterized in that a metered amount of the composition is packaged in a sealed container that is impervious to water vapor. 9. Molding compositions according to claim 8, characterized in that the container made of a layer material of a Metal foil and a plastic film. 10. A method for producing an object with a high impact resistance, characterized in that a deformable mass, which consists of 20 to 40 parts by weight of water, 7.5 to 25 parts by weight of a water-dispersible, self-curing organic resin and consists of essentially inert fillers consisting of individual parts, is brought into the mold, the mass is kept in a wet state during processing, and then dried and hardened into a hard, impact-resistant object will. 11. The method according to claim 10, characterized in that that the wet molding compound is modeled by hand. 12. The method according to claim 10, characterized in that that the wet molding compound is molded by being pressed into a molding cavity. 009848/1285 -13- 13. A method for producing a modeling compound, characterized in that 20 to hO parts by weight of water, 7.5 to 25 parts by weight of an elastic resin and the remainder mineral fillers are dispersed in order to produce a deformable self-supporting mass, measured proportions are used in containers that are suitable for Water vapor is impermeable and the containers are sealed. 14. The method according to claim 13, characterized in that the containers consist of a layer material that is composed of a metal foil and a plastic film, and the container is closed by heating the sheet material to produce a fused seam. 009846/1285