摘要:
Block copolymers are formulated with multifunctional chain extenders. The block copolymers include a soft segment and a hard segment made from a diisocyanate, an alkylene diamine chain extender, and a multifunctional chain extender which provides delayed crosslinking. The multifunctional chain extenders have a functionality ≥3 and typically have at least one OH group. The multifunctional chain extenders may be aliphatic or aromatic triols or polyols, or may have other configurations, as described. The resulting block copolymers have improved mechanical properties such as compression set. They may be used in medical applications, or in industrial applications such as seal and gasket applications, including O-rings, window seals, and automotive gaskets. The initially-formed polyurethane resin behaves as a thermoplastic processable material, while the configured end-use product is thermoset.
摘要:
A coating composition, which may be a two-component coating composition, comprises a film-forming material, a crosslinking agent, and a nonlinear polysiloxane polymer having a functional group reactive with the crosslinking agent. The coating composition exhibits excellent scratch resistance and adhesion of repair coating layers and sealants, such as windshield sealants.
摘要:
A silicone-containing composition comprises the reaction product of a first component and an excess of an isocyanate component relative to the first component to form an isocyanated intermediary. The first component is selected from one of a polysiloxane and a silicone resin. The first component includes a carbon-bonded functional group selected from one of a hydroxyl group and an amine group. The isocyanate component is reactive with the carbon-bonded functional group of the first component. The isocyanated intermediary includes a plurality of isocyanate functional groups. The silicone-containing composition comprises the further reaction product of a second component, which is selected from the other of the polysiloxane and the silicone resin. The second component includes a plurality of carbon-bonded functional groups reactive with the isocyanate functional groups of the isocyanated intermediary for preparing the silicone-containing composition.
摘要:
A polyurethane material is provided that reduces or eliminates the need for use of polycarbonates and improves biostability of the polyurethane material while maintaining preferred physical properties. This polyurethane material is comprised of a hard block segment, such as methylene diphenyl diisocyanate (MDI), a phenol-based silicone soft segment and preferably includes a chain extender, such as butanediol. This polyurethane material is particularly useful for medical implantation applications, especially with respect to coatings for lead and assemblies.
摘要:
The present invention relates to biostable gel comprising: (a) at least one silcon-containing polyol, polyamine, polyepoxy or polyisocyanate having 1 or more functional groups and a molecular weight of at least 20,000 which is cured in the presence of : (b) at least one diol, diamine or diisocyanate having a molecular weight of less than 10,000; and/or (c) an initiator, processes for their preparation and their use in the manufacture and repair of biomaterials and medical devices, articles or implants, in particular the manufacture of asoft tissue implant such as breast implants and the repair of orthopaedic joints such as spinal discs.
摘要:
The invention relates to diisocyanates comprising radiation-curable groups and organopolysiloxane-polyurea block copolymers of general formula (II), which can be obtained therefrom and can be crosslinked using radiation. In said formula (II), (A) can be identical or different and represents a unit of formula (III), (B) can be identical or different and represents a unit of formula (IV), and (C) can be identical or different and represents a unit of formula (V), the radicals and indices having the meanings indicated in claim 1, provided that at least one radical L is supplied in the molecule while the individual blocks (A), (B), and (C) can be statistically distributed in the polymer.
摘要:
The present invention relates to silicon-containing biostable gels and processes for their preparation. The gels possess properties which make them useful in the manufacture and repair of biomaterials and medical devices, articles or implants, in particular the manufacture of soft tissue implants such as breast implants and the repair of orthopaedic joints such as spinal discs.
摘要:
Disclosed are novel hydrophilic copolysiloxanes that are produced by reacting organopolysiloxanes (1) comprising at least one Si-bonded hydrogen atom, preferably at least two Si-bonded hydrogen atoms, per molecule with mostly linear oligomeric or polymeric compounds (2) of general formula R -(A-CnH2n)m-A -H, wherein R represents a monovalent optionally substituted hydrocarbon radical to which Si-H groups can be attached in a hydrosilylation reaction, preferably a hydrocarbon radical containing a multiple aliphatic C-C bond, A represents a bivalent, polar organic radical selected among the group comprising -O-, -C(O)-O-, -O-C(O)-, -O-C(O)-O-, -C(O)-NH-, -NH-C(O)-, a urethane radical, and a urea radical, A represents a bivalent, polar organic radical selected among the group comprising -O-, -NH-, and -NR'- (R' representing a monovalent hydrocarbon radical containing 1 to 18 carbon atoms), n represents a whole number between 1 and 20, and m represents a positive whole number, in a first step, and reacting the obtained intermediate products (4) containing H-A groups with organic compounds (5) comprising at least two isocyanate groups per molecule in a second step, provided that the water content of compounds (1) and (2) which are used for producing the hydrophilic copolysiloxanes is less than 2000 ppm.