US 4,093,759 AGranted

Glass container coated with polyurethane

AssigneeToyo Ink Manufacturing Co., Ltd.

InventorsAkira Otsuki, Michihisa Naito, Yukifumi Mashimo, Akira Ikeda

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Abstract

A process for preventing the scattering of glass fragments in the event of the bursting of a glass container such as a bottle, which comprises coating the surface of the glass container with a resin composition in a thickness of at least 100 microns, said composition comprising a dispersion of (A) a powder with a particle diameter of about 1 to 100 microns of a solid compound capable of reaction with (B) upon heating to form a higher molecular weight cured product, in (B) a normally liquid urethane prepolymer having a molecular weight of at least 400 per isocyanato group, and being capable of forming a film having a tensile strength of at least 300 kg/cm.sup.2 and a percent elongation of at least 200%.

Claims4

Dependent claims

A glass container carrying on the surface thereof a single layer coating of a transparent non-tacky film in a thickness of at least 100 microns and having a tensile strength of at least 300 kg/cm.sup.2 and a percent elongation of at least 200%, said film being a cured high molecular weight compound formed by the reaction of a powder having a particle diameter of about 1 to 100 microns of a solid compound having a melting point of more than 20.degree. C. selected from the group consisting of melamine, benzoguanamine, and acetoguanamine with 0.9 to 1.5 equivalents per equivalent of said powder of a urethane prepolymer which is normally liquid and has at least 2 isocyanate groups and has a molecular weight of at least 400 per isocyanate group, said coating having been cured at a temperature of 180.degree. to 200.degree. C.

Dependencies are inferred from the claim text.