Nitrocellulose composition and process for producing the same
AssigneeDaicel Chemical Industries, Ltd.
InventorsEtsuo Ohtake, Akihiko Higuchi
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Abstract
A nitrocellulose composition in the form of chips containing 50 to 80 wt % of nitrocellulose and less than 1 wt % of water is produced by adding to water-wetted nitrocellulose an organic solvent which dissolves nitrocellulose and polyurethane resin and is inert to isocyanate in an amount of 30 to 300 parts by weight based on 100 parts by weight of dry nitrocellulose, mixing, rolling or extrusion molding, drying at 30.degree. to 55.degree. C., and cutting. This composition is useful as nitrocellulose for magnetic tape binder.
Claims18
A nitrocellulose composition in the form of chips, which composition consists essentially of from 50 to 80 wt.% of nitrocellulose, less than 1 wt%. of water, and the balance is essentially a member selected from the group consisting of (1) a first organic solvent capable of dissolving nitrocellulose and polyurethane resin but which is nonreactive with isocyanate compounds, (2) a mixture of said first organic solvent with a second organic solvent which is miscible with said first organic solvent but which is immiscible with water, (3) a mixture of (1) and a binder resin for binding magnetic powder to a plastic film to make a magnetic tape, and (4) a mixture of (2) with a binder resin for binding magnetic powder to a plastic film to make a magnetic tape.
A process for producing a nitrocellulose composition in the form of chips, comprising the steps of:
- adding from 30 to 300 parts by weight of a first organic solvent to 100 parts of weight, calculated on a dry basis, of water-wetted nitrocellulose, said water-wetted nitrocellulose containing not more than 50 wt.% of water, and said first organic solvent being capable of dissolving nitrocellulose and polyurethane resin but being nonreactive with isocyanate compounds;
- mixing together said first organic solvent and said water-wetted nitrocellulose to form a doughlike mass;
- molding said mass into a molding having a large surface area;
- drying said mass at a temperature in the range of 30.degree. C. to 55.degree. C. to evaporate water from said mass until said mass consists essentially of 50 to 80 wt.% of nitrocellulose, less than 1 wt.% of water, and the balance comprises said first organic solvent;
- and
- cutting said mass to form said chips.
Dependencies are inferred from the claim text.