Email required. Telephone required. Fax Number. Company required. Type of Company please briefly describe your primary business activity required. Street required. State required. Country required. What is the density in pounds per cubic foot? What is the compression deflection?
Is it cellular or solid? If it is cellular, is it open cell or closed cell? Is there a special size sheet as it relates to length and width? What is the thickness? Are there special tolerances? Is there a specification, such as ASTM, etc.? Also, if both a jacket and coil are used as the cooling means, A is the sum of the heat transfer area of the jacket and that of the coil.
As the jacket and coil provided on the polymerizing vessel, any known one can be used. For example, for the jacket, one can be used in which the outside of the polymerizing vessel is covered so that a refrigerant can be passed substantially over the entire area of the side wall and bottom, or one in which only the side wall is covered with a refrigerant phase.
As the coil, a stainless spiral pipe having an inner diameter of about 25 to mm can be used. Normally, it is provided in the polymerizing vessel at a position where it contacts the polymerization reaction liquid.
In order to increase the function and effect of the present invention, it is preferable to cool the surface inside the polymerizing vessel that contacts the polymerization reaction liquid as much as possible e. Through such a jacket or coil, water is generally passed. The temperature and flow rate of water are controlled such that the temperature of the polymerization reaction liquid will be kept at the target temperature. But, if the cooling area is too small, the temperature of the refrigerant supplied to the jacket, etc.
In such a case, it may be difficult to control the polymerization temperature, though depending on the state of mixing in the polymerizing vessel.
As the polymerizing heat of vinyl acetate and ethylene, Such a temperature difference is adjustable by changing the residence time in the polymerizing vessel or the polymerizing rate. By the manufacturing method of the present invention, an ethylene-vinyl acetate copolymer is obtained while suppressing the formation of gelled products and scale. In particular, it is also useful as a raw material for saponified products of ethylene-vinyl acetate copolymer.
The ethylene content is, as described above, controllable by adjusting the ethylene pressure in the polymerizing vessel. The ethylene-vinyl acetate copolymer obtained in the present invention is saponified in the coexistence of a saponifying catalyst. Normally, an alkali metal hydroxide such as sodium hydroxide or potassium hydroxide is used. In certain circumstances, an acidic catalyst is used. Also, the mechanical strength and gas barrier properties of the molded product obtained will considerably decrease.
The solid strands are then cut into pellets and rinsed with water. The rinsed pellets are preferably subjected to chemical treatment e. As such chemicals, formic acid, acetic acid, adipic acid, other carboxylic acid, phosphoric acid, boric acid or their salts may be used.
Among them, acetic acid is preferable. The pellets obtained are melt-molded into desired products after being dried.
In molding, known additives such as reinforcing materials such as glass fiber and carbon fiber, fillers, colorants, stabilizers such as hydrotalcite, foaming agents, drying agents may be suitably added in suitable amounts as necessary. Also, to the ethylene-vinyl acetate copolymer saponified product, a thermoplastic resin for modification may be blended in a suitable amount.
As the melt molding method, any known one such as injection molding, compression molding or extrusion molding can be employed. As an extrusion molding method, a T-die method, blow molding method, pipe extrusion method, wire extrusion method, irregularly shaped die extrusion method, inflation method, etc. The ethylene-vinyl acetate copolymer saponified product may be molded by itself into films, sheets, tapes, bottles, pipes, filaments, extruded products with irregularly shaped sections, etc.
However, co-extrusion molding with other thermoplastic resin layer also can be applied. Hereinbelow, the present invention will be described specifically with reference to Examples.
Using a polymerizing vessel with a capacity of liters and having a cooling jacket and an agitator, continuous polymerization of ethylene and vinyl acetate was carried out under the conditions shown in Table 1. During continuous polymerization, the flow rate of a refrigerant water introduced into the jacket was kept constant, and the polymerizing temperature was controlled to a target value by adjusting the temperature of the refrigerant at inlet of the jacket. For days after the start of polymerization, the concentration of gelled products methanol insoluble content in the reaction liquid discharged from the polymerizing vessel was measured periodically.
It was less than 50 ppm from beginning to end. The interior of the polymerizing vessel was observed after days, but scale was scarcely observed.
When liters of the polymerization reaction liquid obtained by continuous polymerization on the th day from start was passed through a cartridge type polypropylene filter of micron mesh, no clogging was observed in the filter.
It was possible to let the entire amount of liters pass. Then parts of the solution was treated with parts of methanol solution including 0. The side product methyl acetate of the saponification reaction was distilled out of the reaction phase with methanol. The degree of saponification of the saponified ethylene-vinyl acetate copolymer was Then the saponified ethylene-vinyl acetate copolymer solution was treated with steam under pressure of 0.
After solidifying, the strands were cut to obtain ethylene-vinyl acetate copolymer saponified product in the form of pellets. This rinsing was repeated 2 more times. With the help of these cookies we strive to improve our offer for our users. By means of anonymized data of website users we can optimize the user flow. This enables us to improve ads and website content. Jump directly to main navigation Jump directly to content.
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