Abstract:
A silicone rubber sponge composition comprising (A) an organopolysiloxane, (B) a non-cyano organic azo blowing agent which is thermally decomposable to cause thickening or curing of component (A), (C) an azodicarbonamide or dinitrosopentamethylenetetramine blowing agent, and (D) a curing agent is crosslinkable and expandable with atmospheric hot air. The composition makes it possible to freely control the blowing magnification and the cell size of the resulting sponge, enabling to form a fully expanded silicone rubber sponge with crosslinked surface. The sponge free of cyano compounds is least toxic.
Abstract:
The foam sheet of the present invention is biodegradable, can be recycled, has good processability, is lightweight, exhibits excellent appearance, has practically satisfactory heat resistance and is more acceptable to the environment.There is provided a crosslinked biodegradable resin continuous foam sheet comprising biodegradable resin, and has an expansion rate of about 1.5 to about 50 and a gel fraction of about 3% or more.There is further provided a method for producing the foam sheet comprising the steps of: (1) preparing a sheet from a resin composition comprising a biodegradable resin, a thermal decomposable blowing agent, and a crosslinking promoter; (2) irradiating the resulting sheet with an ionizing radiation to crosslink the resin composition; and (3) subjecting the crosslinked sheet to heat treatment to continuously prepare a crosslinked foam sheet.Thus, the foam sheet of the present invention can be used in a wide range of practical applications such as, for example, interior materials for an automobile, thermal insulators such as a pipe covering, cushioning materials such as a tape core and the like.
Abstract:
The present invention features a method for the formation of superporous hydrogels using an ion-equilibration technique. Anionic polysaccharides are included in the hydrogel reaction mixture and cations are introduced either during or after hydrogel formation. Properties of the resulting hydrogel can be subsequently adjusted by treating the cation-complexed gel with a different cation or cation mixture under equilibrating conditions. It has been found that by properly adjusting the cations and the sequence in which they are used in the equilibration process, superporous hydrogels can be formed that are highly absorbent while maintaining favorable structural properties, including strength, ruggedness, and resiliency. It has also been found that applying appropriate dehydration conditions to them after their formation can further stabilize the superporous hydrogels formed by the method of the invention.
Abstract:
There is disclosed a process for producing alkenyl aromatic foams utilizing a combination of atmospheric and organic gases as blowing agent, preferably using greater than 30% by weight of atmospheric gas, and preferably also using a predetermined about of a masterbatch mix comprising a styrenic polymer, a rubbery block copolymer, and a solid blowing agent. Also disclosed are alkenyl aromatic foams produced by the process which exhibit increased densities, increased thermoforming capabilities, increased post-expansion properties, and increased retainment of the atmospheric and organic gases.
Abstract:
The present invention relates to novel blowing agent preparations, to a process for their preparation, and to their use. The present invention also relates to a process for the preparation of azodicarbonamide.
Abstract:
The present invention relates to novel blowing agent preparations, to a process for their preparation, and to their use. The present invention also relates to a process for the preparation of azodicarbonamide.
Abstract:
The invention provides a thermally expandable material comprising a foam composition containing: 100 parts by weight of (a) a crosslinkable polymer material; and 5 to 300 parts by weight of (b) a crystalline thermoplastic resin having oxygen in its molecule. The invention also provides a foam composition for obtaining a thermally expandable material that is expandable by heat from a compressed state, the composition comprising a crystalline thermoplastic resin formed in a predetermined shape and crosslinked.
Abstract:
It is an object of the present invention to provide a foamable thermoplastic elastomer composition which produces a stable foam. The present invention provides a foamable thermoplastic elastomer composition which contains: (a) 10 to 90 parts by weight of one of an olefin-based resin and rubber having a melting or softening point of 140null C. or lower, (b) 9 to 85 parts by weight of heat-expandable microcapsules expanding at 120 to 300null C., (c) 1 to 50 parts by weight of a volatile composition, wherein the components (a) to (c) total 100 parts by weight, and another aspect of the invention provides a foamable thermoplastic elastomer composition which contains; the above said (a) to (c) and (d) 50 to 99 parts by weight of a thermoplastic resin, wherein the components (a) to (d) total 100 parts by weight, and also provides a method of producing the above foamable thermoplastic elastomer composition in two stages.
Abstract:
The present invention relates to a polymeric compound comprising(a) 100 parts by weight of a block copolymer comprising at least two external monovinyl aromatic hydrocarbon blocks and at least one internal hydrogenated conjugated diene block, wherein the total monovinyl aromatic hydrocarbon content is from 20 to 50% by weight and the total apparent molecular weight is from 140,000 g/mol to 400,000 g/mol;(b) 50 to 250 phr of a plasticiser;(c) 10 to 100 phr of a polybutene-1 polymer having a melt index at 2.16 kg/190.degree. C. of from 0.05 to 400;(d) a blowing agent.The present invention further relates to use of the compound for the preparation of foamed compounds; to a foaming process; to a masterbatch blend; to a foamed compound; and to articles containing the foamed compound.
Abstract:
A molded closure for a liquid container comprising a thermoplastic elastomer and a blowing agent. The molded closure is particularly suitable for use as a synthetic wine cork in a wine bottle. The molded closure does not permit passage of oxygen into the container, does not absorb oxygen from the contents of the container, can be removed from the container using a corkscrew without significant expansion, crumbling or disintegration, does not significantly taint a liquid in the container, permits the container to be placed horizontally immediately after insertion of the molded closure, and can permanently retain printed matter on its surface.