SU47078A1 - The method of preparation of plastics - Google Patents

Description

The rapid growth of the plastics industry is increasingly covering new areas of their application. However, there is a significant shortage of the main raw material, phenol and formalin, which makes it impossible to satisfy all needs with plastics. This prompted the authors to engage in the production of such plastics with bakelite properties that would contain as little as possible scarce raw material.

As you know, there are many ways to produce plastics from lignin, wood, by all sorts of treatments, fused wood, etc. However, all of these methods mostly result either in defective materials or in an extremely expensive and complicated manufacturing process.

It has been established that any cellulose, LIGNINO-, pulp-resinous material, such as wood, bark, cones, needles, peat, etc., can be processed into a completely benign and often with high plastic properties in a simple or cheap way. material.

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The method is as follows. Any of the above material crushed, torn into fibers, in the form of paper, fabric or plywood veneer is impregnated with a certain insignificant amount of a solution of novolac resin in furfural with 15 o hexane (1 part by weight of resin per 1 part by furfural). The impregnated material is pressed raw in the normal conditions of pressing of polymerizable plastics.

The peculiarity of this method is that, despite the use of a small amount of the order of 15-20 ° C of this solution, an extremely monolithic product of any complex configuration is formed. This is achieved by pressing raw. Under the influence of temperature and pressure, furfural reacts with lignin, cellulose or resinous substances to form a monolithic plastic, while excess furfural is bound to novolac and urotropine, forming additional binding material, which is mixed with the product of furfural with lignin, a piece of pulp, and a mixture of lactin, and pulp, and a mixture of lactin and resin. substances gives a polymerizable mass. The resin solution in furfural liquid consistency at ordinary temperature, in contact with the hot mold, is liquefied and ideally impregnates the cellulosic material under pressure, which is an excellent lubricant to give fluidity. In addition, furfural is known to be a good plasticizer and solvent, which also has a beneficial effect on the course of the above process, especially since it proceeds at elevated temperature and pressure. Pretreatment of these substances with furfural or mixing with the resin in the usual way does not achieve the goal; therefore, the peculiarity of this method lies in pressing in the raw state, i.e., in carrying out the process of forming the plastic directly in the mold when pressing products.

Example 1. 100 in. Horned or uncooked, pre-dried sawdust or ground bark, cones, needles, peat, waste from tanning of skin, etc., are mixed with 15-25 c. including solution in furfurol novolac resin with hexamine (1 in. n. Novolac resin with hexamine per 1 in. part of furfural) to form a homogeneous mass in a Werner agitator or a ball mill. The mixture is pressed into the product at a temperature of 150-160 ° and a pressure of 250-350 KZJCM, followed by cooling to avoid blistering, or without cooling in the case of thin-walled parts.

Example 2. Wood paper, cardboard, fabric, plywood veneer is coated with a thin layer of the above solution and immediately pressed or wound by methods of producing laminated plastics at a temperature of 150160 °, pressure 75-120 KZJCM, followed by cooling under pressure. The resulting laminates are characterized by good solidity and do not exfoliate.

The material is very easily machined with conventional steel tools and holds the thread. Waste from processing can be added to the newly prepared mass, thus being disposed of.

The field of application of the mass obtained by the described method is extremely extensive and embraces almost all objects made from ordinary bakelite plastics; besides, in view of good workability, the mass can be widely used in imitation of expensive varieties, wood for furniture, parquet, as a facing material, etc.

The subject matter of the invention.

The method of preparation of plastics from materials containing lignin, characterized in that the said material is treated with an insignificant amount of solution in furfural of the novolac resin with hexamine and is compressed in a raw form under normal conditions.