摘要:
This invention provides novel side chain liquid crystalline polymers which exhibit nonlinear optical response, and which have utility as a transparent optical component in electrooptic light modulator devices.An invention side chain liquid crystalline polymer is illustrated by poly[6-(4-nitrobiphenyloxy)hexyl methacrylate]: ##STR1##
摘要:
This invention provides novel isotropic acrylic copolymers which exhibit nonlinear optical response, and which have utility as a transparent optical component in optical light switch and light modulator devices.An invention isotropic acrylic copolymer is illustrated by the following structure: ##STR1##
摘要:
This invention provides novel isotropic acrylic copolymers which exhibit nonlinear optical response, and which have utility as a transparent optical component in optical light switch and light modulator devices.An invention isotropic acrylic copolymer is illustrated by the following structure: ##STR1##
摘要:
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.
摘要:
An improved polymerization process is provided for the formation of a polyester which is capable of forming an anisotropic melt phase and which optionally may include amide linkages. An approximately 0.25 to 4 percent molar excess of aromatic hydroxyl monomer and/or aromatic amine monomer and/or an esterified and/or amidated derivative thereof is provided in the polymerization zone during the polymerization reaction. Such monomer imparts dioxyaryl, diaminoaryl, or oxyaminoaryl units to the interior of the resulting polymer chains and causes the polymer chains to terminate in hydroxyl end groups and/or an esterified derivative thereof and/or amino end groups and/or an amidated derivative thereof wherein the polymer chains achieve a predetermined average chain length through the depletion of other monomers present in the polymerization zone. The resulting polyester unlike the usual product of the prior art is substantially incapable of additional chain growth upon subsequent heating and accordingly may be relied upon to maintain a substantially constant viscosity during melt processing regardless of the duration of heating.
摘要:
An improved polymerization process is provided for the formation of a polyester which is capable of forming an anisotropic melt phase and which optionally may include amide linkages. An approximately 0.25 to 4 percent molar excess of aromatic dicarboxylic acid monomer (e.g. terephthalic acid) and/or an esterified derivative thereof is provided in the polymerization zone during the polymerization reaction. Such monomer imparts dicarboxyaryl units to the interior of the resulting polymer chains and causes the polymer chains to terminate in carboxylic acid end groups and/or an esterified derivative thereof wherein the polymer chains achieve a predetermined average chain length through the depletion of other monomers present in the polymerization zone. The resulting polyester unlike the usual product of the prior art is substantially incapable of additional chain growth upon subsequent heating and accordingly may be relied upon to maintain a substantially constant viscosity during melt processing regardless of the duration of heating.
摘要:
The present invention relates to a composition for stabilizing vitamine C in water phase and method for stabilizing vitamine C using the composition. More particularly, this invention relates to a composition wherein the vitamine C is effectively prevented from decomposing by an exterior environment such as water, temperature, and light by stabilizing the vitamine C with the use of a cationic polymer and an anionic polymer, and thereof method for stabilizing vitamine C.
摘要:
The invention pertains, in part, to a toner composition that is suitable for developing latent electrostatic images and being comprised of substantially spherical polyester particles with a volume average diameter in the range of 2-10 microns and which contain a wax component in the interior. The invention also pertains to a method of producing the toner composition, which is characterized by encapsulating a wax within resin particles by chemical milling a polyester resin and a wax in a polar solvent and in the further presence of an evaporable processing aid.
摘要:
A particulate toner composition is provided with toner resin particles containing a resin component, a colorant component, and optionally a charge control agent characterized in that the toner resin particles have a micro-serrated surface exhibiting a surface roughness index of greater than about 1.2. The novel toner particles are produced by employing a vaporizable plasticizer which is flashed off during processing.
摘要:
This invention provides novel side chain polymers which exhibit nonlinear optical response, and which have utility as a transparent optical component in all-optical and electrooptical light switch and light modulator devices.An invention side chain polymer is illustrated by the following structure: ##STR1##