Special material for white polyvinylidene fluoride cast film

Abstract

The invention discloses a special material for a white polyvinylidene fluoride cast film. The formula comprises the following components in parts by weight: 50-90 parts of polyvinylidene fluoride, 5-20 parts of titanium dioxide and 5-30 parts of polymethyl methacrylate; and the formula can further contain 0.05-1 weight part of antioxidant and / or 3-10 parts of compatibilizer. In the special material disclosed by the invention, the fluidity of polyvinylidene fluoride is improved by use of high-fluidity polymethyl methacrylate, and the casting film formation is facilitated; and meanwhile, the special material is prepared by a two-step method, namely that the polymethyl methacrylate and titanium dioxide masterbatch are prepared first, and then the special material for white polyvinylidene fluoride cast film is prepared, thus the decomposition promoting effect of the titanium dioxide on polyvinylidene fluoride is reduced. The special material disclosed by the invention easily flows in a casting mould while the scorching phenomenon is avoided; and the prepared polyvinylidene fluoride film has the advantages of uniform whiteness, no obvious dark lines, uniform film thickness and no obvious crystal points.

Description

technical field [0001] The invention relates to a special white polyvinylidene fluoride salivation film material, which is suitable for a salivation process, is easy to flow and is well dispersed, and is used for preparing a weather-resistant, ultraviolet-blocking, water- and gas-blocking white film for outdoor use. Background technique [0002] Polyvinylidene fluoride (PVDF) is an important member of the fluoroplastic family. Due to the stability of its chemical structure C-F bond, PVDF materials have excellent resistance to ultraviolet damage, and are resistant to chemical corrosion and have low water vapor The transmittance is currently widely used in the solar photovoltaic industry, construction industry, and chemical industry. [0003] There are generally two processes for preparing plastic films: salivation film formation and blown film formation. Compared with the blown film forming process, the salivation process has the advantages of more uniform film thickness, hi...

AI Technical Summary

Problems solved by technology

The difficulty of preparing PVDF film by the salivation method is that this material has poor fluidity, and its flow viscosity is more than ten times higher than that of ordinary polyethylene; at the same time, it is difficult to melt and plasticize, and it is easy to produce crystal points and other poor appearance.

Especially for the white polyvinylidene fluoride film, due to the addition of titanium dioxide (TiO 2 ) will promote the decomposition of PVDF, reduce the decomposition temperature of PVDF from 370°C to 240°C, release highly toxic HF, and even cause dangerous phenomena such as material scorching and explosion

In the prior art, the technical solution of directly mixing and granulating polyvinylidene fluoride and titanium dioxide is adopted, and the prepared polyvinylidene fluoride white film has uneven whiteness, obvious dark lines, many crystal points, and even raw material scorching often occurs wait for danger

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