Abstract: The present invention is directed to a porous copolymer micro-particle having a high oil absorbency.

Abstract: Monomeric units useful in reducing the modulus of hydrogels are disclosed. Silicone hydrogels including the subject monomeric units are especially useful in the formation of biomedical articles such as silicone hydrogel contact lenses. ##STR1## wherein: A is an activated unsaturated group;R and D independently are alkyl, alkylene or haloalkyl groups having 1 to 10 carbon atoms wherein said carbon atoms may include ether linkages therebetween;R.sub.1, R.sub.2, R.sub.3 and R.sub.4 are independently selected from: alkyl or haloalkyl groups wherein ether linkages may be included between carbon atoms; siloxane groups; and carbocyclic ring groups having from 6 to 18 carbon atoms;m is an integer from 1 to 500; n is an integer from 1 to 20; x and y are 0 or 1;z is 1 or 2; and x+y+z=3;so long as at least one of R.sub.1 or R.sub.2 is an alkyl group having from 1 to 10 carbon atoms.

Abstract: Polymers and copolymers of one or more fluorinated dienes of structure CFX.sup.1 .dbd.CX.sup.2 --O--CX.sup.3 X.sup.4 --O--CX.sup.2 .dbd.CX.sup.1 F, wherein X.sup.1 and X.sup.2 are F, Cl or H, and X.sup.3 and X.sup.4 are F or CF.sub.3, wherein said dienes essentially form cyclic repetitive units, the comonomers used for preparing copolymers being ethylene unsaturated fluorinated compounds.Processes for preparing the fluorinated dienes having said structure which comprise the reaction in solution between one halogenated olefin and one hypofluorite CX.sup.3 X.sup.4 (OF).sub.2, wherein X.sup.3 and X.sup.4 are F or CF.sub.3, and the dehalogenation or dehydrohalogenation of the linear adduct between one hypofluorite molecule and two olefin molecules.The polymers and copolymers of the invention are particularly suitable for preparing coatings for applications at high temperatures.

Abstract: Polytetrafluoroethylene molding powder which comprises 0.01 to 1% by weight of a perfluoro(vinyl ether) unit and which has a heat of crystallization of 18.0 to 25.0 J/g. The molding powder provides a molded article which has a flex life of not less than 7 million cycles, a creep resistance (total deformation at 200.degree. C.) of not more than 20%, and a creep resistance (total deformation at 25.degree. C.) of not more than 15%. The polytetrafluoroethylene molding powder which is excellent in both creep resistance and flex fatigue resistance is provided as a molding material for parts which are repeatedly bent such as pump.

Abstract: A pressure sensitive adhesive that includes the polymerization product of:(a) 25-97 parts by weight of an acrylic acid ester of a monohydric alcohol whose homopolymer has a T.sub.g less than 0.degree. C.;(b) 3-75 parts by weight of a non-polar ethylenically unsaturated monomer whose homopolymer has a solubility parameter of no greater than 10.50 and a T.sub.g greater than 15.degree. C.; and(c) 0-5 parts by weight of a polar ethylenically unsaturated monomer whose homopolymer has a solubility parameter of greater than 10.50 and a T.sub.g greater than 15.degree. C. The relative amounts of the acrylic acid ester, the non-polar ethylenically unsaturated monomer, and the polar ethylenically unsaturated monomer are chosen such that the 90.degree. peel adhesion of the pressure sensitive adhesive to a polypropylene surface is at least 2 lbs/0.5 in. after a 72 hour dwell at room temperature as measured according to Test Procedure B.

Abstract: A pressure sensitive adhesive that includes the polymerization product of:(a) 25-97 parts by weight of an acrylic acid ester of a monohydric alcohol whose homopolymer has a T.sub.g less than 0.degree. C.;(b) 3-75 parts by weight of a non-polar ethylenically unsaturated monomer whose homopolymer has a solubility parameter of no greater than 10.50 and a T.sub.g greater than 15.degree. C.; and(c) 0-5 parts by weight of a polar ethylenically unsaturated monomer whose homopolymer has a solubility parameter of greater than 10.50 and a T.sub.g greater than 15.degree. C. The relative amounts of the acrylic acid ester, the non-polar ethylenically unsaturated monomer, and the polar ethylenically unsaturated monomer are chosen such that the 90.degree. peel adhesion of the pressure sensitive adhesive to a surface provided with 1.5.+-.0.25 mg/in.sup.2 oil is greater than zero after a 10 second dwell at room temperature as measured according to Test Procedure B.

Abstract: A crosslinkable acrylic copolymer sealant composition has a stabilized viscosity in that the viscosity does not unduly increase nor does the material gel on storage for periods of time up to and including one year. The stabilized viscosity is unexpectedly achieved by adding moisture scavengers either before and/or during the polymerization of the various monomers. The sealant composition is suitable for use in high movement applications as well as to metal and glass substrates.

Abstract: Process for preparing beads based on acrylic polymers which comprises the preparation of microbeads from 10 to 40 micron by means of a polymerization process in suspension of acrylic monomers in the presence of at least a crosslinking monomer at least bifunctional, characterized in that a second polymerization of the acrylic monomers is carried out in absence of crosslinking monomers and using as suspending phase a fraction of the suspension obtained in the preceding polymerization containing a crosslinking agent, said fraction containing an amount of microbeads comprised between 3 and 40% by weight with respect to the final polymer obtained in the second polymerization.

Abstract: Copolymers of tetrafluoroethylene, hexafluoropropylene, and perfluoro(ethyl vinyl ether) can be extruded at higher rates than corresponding copolymers containing perfluoro(propyl vinyl ether).

Abstract: A polymer comprising repeating units of the formula ##STR1## wherein R.sup.1 , R.sup.2 and R.sup.3 are, independently of one another, hydrogen atoms or alkyl groups,X is CO or SO.sub.2, andY and Z are, independently of one another, alkyl, alkenyl, cycloalkyl, aryl or heterocyclic radicals, or Y and Z are linked to one another and are constituents of a five-membered or six-membered hetero-cyclic ring.

Abstract: A water-soluble cationic copolymer comprising a reaction product of N-vinylamide having the general formula: ##STR1## and a cationic quaternary amine having the formula: ##STR2## wherein Y is C(.dbd.O)O(CH.sub.2).sub.n N.sup..sym. R.sup.4 R.sup.5 R.sup.6 X.sup..crclbar., or ##STR3## X.sup..crclbar.,n is 1 to 5; R.sup.1, R.sup.2, R.sup.3 are independently H or C.sub.1 to C.sub.3 alkyl, R.sup.4, R.sup.5, and R.sup.6 are independently C.sub.1 to C.sub.3 alkyl, X is a halide, hydroxyl or alkylsulfate anion.The copolymers of this invention are useful as flocculating agents, and are particularly useful as drainage/retention aids in pulp and papermaking operations.

Abstract: A process for the preparation of low-hydrazine polymers based on basic vinyl monomers by free-radical solution polymerization in aqueous medium in the presence, as compound which forms free radicals, of an azo compound which has alkoxycarbonyl groups on the carbon atoms adjacent to the azo group.

Abstract: A process for preparing a water-soluble polymer dispersion is herein provided which is characterized by polymerizing from about 10 to 50 mole percent of a monomer having a formula (II); from about 1 to 50 mole percent of N-alkylacrylamide, N,N-dialkylacrylamide or mixtures thereof; having a formula (III) from about 1 to 70 mole percent acrylamide; and optionally up to about 4 mole percent of a monomer having a formula (I) having a benzyl functionality. The polymerization is carried out in the presence of an aqueous solution of a polyvalent anionic salt which contains (1) a water soluble cationic polymer which is insoluble in the aqueous salt solution and (2) a water soluble cationic polymer which is soluble in the aqueous salt solution.

Abstract: The present invention relates to peroxide crosslinkable fluororubbers prepared from polymerized units of vinylidene fluoride, at least one fluorinated propene and/or a fluorinated methyl vinyl ether, at least one perfluoro(polyoxaalkyl vinyl ether), optionally tetrafluoroethylene and crosslinking-active reactive sites, to a process for the production thereof and to the use thereof.

Abstract: A process for polymerizing a vinyl ether monomer which comprises contacting the vinyl ether with an initiator system of silicon dioxide and a one or more metallic oxides.

Abstract: A process for making a fluoropolymer is disclosed. The process comprises solubilizing a fluoromonomer in solvent comprising a carbon dioxide fluid, and then polymerizing the fluoromonomer to produce a the fluoropolymer. A preferred solvent for carrying out the process is supercritical carbon dioxide; preferred fluoromonomers for carrying out the process are fluoroacrylate monomers such as 1,1-dihydroperfluorooctyl acrylate. The polymerization step is preferably carried out in the presence of an initiator such as azobisisobutyronitrile.

Abstract: An acrylic rubber composition containing an acrylic ester polymer having a weight-average molecular weight of at least 8,000,000 as a rubber component. This acrylic rubber composition which is free from the disadvantages associated with conventional acrylic rubber can be obtained economically by avoiding the use of expensive raw materials and complicated and therefore costly steps. The acrylic rubber composition shows improvements in the properties inherently possessed by acrylic rubber, i.e., heat resistance, oil resistance, weather resistance, and ozone resistance; exhibits excellent roll processability, gasoline resistance, gas hole resistance, and tensile strength/extensibility balance; and in addition, has high mechanical strength and excellent compression set resistance.

Abstract: Process for the free-radical polymerization of at least one olefinically unsaturated monomer, the polymerization being performed in the presence of a compound for effecting molecular weight control, being a CoII chelate of the following formula: ##STR1## wherein each group X is a divalent group which forms with the two carbon atoms to which it is bonded a pericondensed polycyclic group, being a group having 3 or more carbocyclic rings where the oxime-containing carbocyclic ring has carbon atoms in common with 2 or more of the other rings, the polycyclic group being unsubstituted (apart from the oxime groups) or having at least one hydrocarbyl substituent; and wherein each group Q is independently selected from F, Cl, Br, OH, C.sub.1-12 alkoxy, aryloxy, C.sub.

Abstract: Particulate superabsorbent polymeric material which is a partially neutralised polymer of an ethylenically unsaturated carboxylic monomer cross linked by a triethylenic or higher ethylenic cross linking agent, preferably tetra allyl ammonium chloride, absorbs above 15 grams, and often above 18 grams, aqueous saline per gram polymeric material in 60 minutes under a load of 63,000 dynes per square centimeter. The polymer preferably has surface cross linking caused by contacting the polymer particles with inorganic and/or covalent cross linking agent for the polymer.

Abstract: In a polymerizable dental restorative resin composition useful as a dental composite resin and/or a denture/denture base material comprising at least one binder resin, a diluent monomer, at least one filler, optionally, a photopolymerization system comprising an initiator for initiating polymerization of the composite resin upon exposure to visible light and an accelerator, and an initiator for initiating polymerization of the composite resin upon application of heat, the improvement imparting shelf stability and substantially eliminating discoloration is provided comprising the initiator for initiating polymerization upon application of heat having the general formula:R--N.dbd.N--R'wherein R and R' can be the same or different, and are selected from the group consisting of oxygen-free aliphatic, cycloaliphatic, aromatic, and heterocyclic moieties.