American Can Company

Celanese Gmbh

Hoechst Celanese Corporation

Hoebbst Celanese Corporation

Charles E McChesney

Robert J McHenry

James A Wachtel

Hyun-Nam Yoon

Nancy C Eickman

Gary E Williams

Stephen M Sinker

Joseph J Baron, Jr

Marvin L Doerr

Raymond W Rupp

An improved thermoplastic molding composition is provided which is particularly suited for use in the impervious void-free encapsulation on a relatively expeditious basis of an electronic component wherein the preformed electronic component is positioned in a mold cavity prior to the introduction of the molding composition via injection molding. The molding composition comprises a melt processable thermotropic liquid crystalline polymer which is of a relatively low weight average molecular weight of approximately 4,000 to 25,000 (e.g. approximately 4,000 to 10,000) and which is substantially incapable of further chain growth upon heating. Uniformly dispersed within the liquid crystalline polymer is approximately 40 to 80 percent by weight (e.g. approximately 50 to 75 percent by weight) of a particulate inorganic material (preferably of silicon dioxide) which serves to advantageously decrease its volumetric coefficient of thermal expansion and to advantageously increase its thermal conductivity. In a preferred embodiment the electronic component which is encapsulated is a semiconductor device, such a relatively delicate quad or dual-in-line integrated circuit device which is assembled onto a flat prestamped lead frame or other conductive device having a plurality of leads which extend outside the area which is encapsulated. The resulting encapsulated electronic component is well protected in spite of the relatively low molecular weight of the liquid crystalline polymer and is capable of satisfactory service for an extended period of time even if adverse environmental conditions are encountered. A rugged commonly nonburning and relatively inexpensive package is provided.

Electronic component encapsulated with a composition comprising a

Encapsulation of electronic components

An improved thermoplastic molding composition is provided which is particularly suited for use in the impervious void-free encapsulation on a relatively expeditious basis of an electronic component wherein the preformed electronic component is positioned in a mold cavity prior to the introduction of the molding composition via injection molding. The molding composition comprises a melt processable thermotropic liquid crystalline polymer which is of a relatively low weight average molecular weight of approximately 4,000 to 25,000 (e.g. approximately 4,000 to 10,000) and which is substantially incapable of further chain growth upon heating. Uniformly dispersed within the liquid crystalline polymer is approximately 40 to 80 percent by weight (e.g. approximately 50 to 75 percent by weight) of a particulate inorganic material (preferably of silicon dioxide) which serves to advantageously decrease its volumetric coefficient of thermal expansion and to advantageously increase its thermal conductivity. In a preferred embodiment the electronic component which is encapsulated is a semiconductor device, such as relatively delicate quad or dual-in-line integrated circuit device which is assembled onto a flat prestamped lead frame or other conductive device having a plurality of leads which extend outside the area which is encapsulated. The resulting encapsulated electronic component is well protected in spite of the relatively low molecular weight of the liquid crystalline polymer and is capable of satisfactory service for an extended period of time even if adverse environmental conditions are encountered. A rugged commonly non-burning and relatively inexpensive package is provided.

Encapsulation of electronic components with anisotropic thermoplastic

There is disclosed an improved modified polymer suitable for use in making hollow containers by conventional extrusion blow molding. It is a specific type of end-capped and branched polyethylene terephthalate polymer or copolymer. In the improvement, the end-cap comprises the reacted component of a difunctional acid or alkali metal salt of a difunctional acid having the formula: ##STR1## wherein: X has a valency of 6 and is selected from sulfur, selenium, and tellurium;

Modified PET polymers and copolymers suitable for extrusion blow molding

There is disclosed an improved modified polymer suitable for use in making hollow containers by conventional extrusion blow molding. It is a specific type of end-capped and branched polyethylene terephthalate polymer or copolymer. In the improvement, (a) the end-cap comprises the reacted component of a monofunctional acid having a normal boiling point or sublimation point less than above about 200.degree. C.; and (b) the monofunctional acid is an aromatic monocarboxylic acid having the formula: ##STR1## wherein: R.sub.3 and/or R.sub.5 is an alkoxy group containing from 1 to 10 carbon atoms; and, the remaining R's are hydrogen. The preferred monocarboxylic acid is m-anisic acid. The product typically contains few large gels having diameters greater than 0.1 mm.

A molecularly oriented article having a tubular sidewall is blow-molded from a thermoplastic parison which is heat-treated prior to blowing to provide the parison sidewall with a temperature gradient wherein the temperature of the inside of the sidewall is greater than that of the outside, both of said temperatures being within the orientation temperature range of the thermoplastic. The temperature gradient results in the sidewall of the article having a different and more uniform circumferential orientation release stress distribution radially across the sidewall than would be obtained if the parison were blown isothermally.

Method for making a blow molded oriented plastic bottle

A thermoplastic bottle has a unique combination of properties. The bottle is characterized by a very high level of molecular orientation, and possesses the properties of high impact strength, low gas permeability and excellent resistance to creep strain under tensile load. A blowing process for fabricating the bottle is also taught which features a means of substantially improving the resistance to creep strain.

Blown thermoplastic bottle and method for making same

A thermoplastic bottle having a unique combination of properties. The bottle is characterized by a very high level of molecular orientation, and possesses the properties of high impact strength, low gas permeability and excellent resistance to creep strain under tensile load. A blowing process for fabricating the bottle is also taught which features a means for substantially improving the resistance to creep strain.

A molecularly oriented article having a tubular sidewall is blow-molded from a thermoplastic parison which is heat-treated prior to blowing to provide the parison sidewall with a temperature gradient wherein the temperature of the inside of the sidewall is greater than that of the outside, both of said temperature being within the orientation temperature range of the thermoplastic. The temperature gradient results in the sidewall of the article having a different and more uniform circumferential orientation release stress distribution radially across the sidewall than would be obtained if the parison were blown isothermally.

Growing community of inventors

Monmouth Junction, NJ, United States of America

Charles E McChesney