Hoechst Celanese Corporation

Mitsubishi Polyester Film Gmbh

R Scott Caines

John M Heberger

David Rudd

Stephen J Gust

A method is provided for forming a strippable or dissolvable release coating on the surface of substrate such as a flexible polymeric film or web. The release coating is subsequently coated with a layer of material and then dissolved in a solvent to release the layer. The release coating is made from a copolymer of methylmethacrylate and ethylacrylate or from a homopolymer of polyacrylic acid. Release coatings made of methylmethacrylate and ethylacrylate copolymers having glass transition temperatures of about 60.degree. C. or greater, or made of a ipolyacrylic acid homopolymer having a glass transition temperature of about 100.degree. C. or higher, are also provided. The release coatings provide excellent supporting substrates for the formation of an overcoated metallized layer, are readily strippable in acetone, and can be formed during an in-line process which begins with drawing a flexible film or web from a molten polymeric material. Methods are also provided for making metallized layers used in the production of optically variable flakes and devices.

Polymeric coated substrates for producing optically variable products

A method is provided for forming a dissolvable or strippable polymeric release coating on the surface of flexible web, forming an overcoated metallized or optically variable layer on said release coating, and stripping or dissolving the release coating to release the overcoated layer. The release coating comprises a polymer of crotonic acid which is soluble in a solvent such as acetone. The polymer may be a copolymer of crotonic acid and at least one vinyl ester such as vinyl acetate. The release coating may be formed during an in-line process which begins with drawing the flexible web from a molten polymeric material. The methods are particularly advantageous for forming optically variable flakes and multilayered optically variable devices.

Crotonic acid polymer coated substrates for producing optically variable

The invention provides spill-resistent drinking straws which are normally maintained in a substantially sealed state such that liquid is substantially prevented from flowing through the straw, but which can be manually deformed to an open state for use in drinking in which liquid can readily flow through the straw. A biasing member which is either integrally formed in the straw or attached to the straw maintains the straw in the substantially sealed state and automatically returns the straw from the open state to the substantially sealed state in the absence of external force. In some embodiments of the invention, the straw is constructed such that it is substantially sealed when in a bent condition such that the straw is crimped and thereby substantially sealed. In other embodiments of the invention, the straw is maintained in a substantially sealed position when in a straightened form.

Spill-resistant drinking straw

A two-step, sequential coating method is disclosed which permits the use of aqueous precursor solutions to coat water-insoluble compounds onto thermoplastic film. In a preferred embodiment, an aqueous oleic acid/ammonium oleate solution is coated onto amorphous polyester sheet which is subsequently monoaxially oriented by stretching in the machine direction, and coated with an aqueous solution of calcium hydroxide, thereby forming a layer of calcium oleate in situ. The coated film is subsequently biaxially oriented by stretching in the transverse direction, and heat-set.

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Greenville, SC, United States of America

R Scott Caines