4422 results about "Emulsion polymerization" patented technology

The invention relates to an aqueous emulsion polymerization of fluorinated monomers using perfluoropolyethers of the following formula (I) or (II). In particular, the perfluoropolyether surfactants correspond to formula (I) or (II)

CF₃—(OCF₂)_m—O—CF₂—X  (I)

wherein m has a value of 1 to 6 and X represents a carboxylic acid group or salt thereof,

CF₃—O—(CF₂)₃—(OCF(CF₃)—CF₂)_z—O-L-Y  (II)

wherein z has a value of 0, 1, 2 or 3, L represents a divalent linking group selected from —CF(CF₃)—, —CF₂— and —CF₂CF₂— and Y represents a carboxylic acid group or salt thereof. The invention further relates to an aqueous dispersion of a fluoropolymer having the aforementioned perfluoropolyether surfactant(s).

The invention provides a fluorinated surfactant having the general formula:

[R_f—(O)_t—CHF—(CF₂)_n—COO—]_iXⁱ⁺  (I)

wherein R_f represents a partially or fully fluorinated aliphatic group optionally interrupted with one or more oxygen atoms, t is 0 or 1 and n is 0 or 1, Xⁱ⁺ represents a cation having a valence i and i is 1, 2 or 3. The surfactant can be used in emulsion polymerization of fluoromonomers to prepare fluoropolymers.

The present invention provides an aqueous emulsion polymerization of fluorinated monomers including gaseous fluorinated monomers using a perfluoro ether surfactant as an emulsifier. The perfluoro ether surfactants correspond to formula (I)

R_f—O—CF₂CF₂—X   (I)

wherein R_f represents a linear or branched perfluoroalkyl group having 1, 2, 3 or 4 carbon atoms and X represents a carboxylic acid group or salt thereof. In a further aspect, the invention also provides an aqueous fluoropolymer dispersion comprising the perfluoro ether surfactant and the use of such dispersion in the coating or impregnation of substrates.

The present invention provides a fluorinated surfactant having the general formula:

[R_f—(O)_t—CQH—CF₂—O]_n—R-G  (I)

wherein R_f represents a partially or fully fluorinated aliphatic group optionally interrupted with one or more oxygen atoms, Q is CF₃ or F, R is an aliphatic or aromatic hydrocarbon group, G represents a carboxylic or sulphonic acid or salt thereof, t is 0 or 1 and n is 1, 2 or 3. The surfactant is particularly useful in polymerizing fluorinated monomers in an aqueous emulsion polymerization.

Aqueous dispersions are disclosed, having a minimum film formation temperature no greater than about 50° C., that include a multi-stage emulsion polymer made by a process that includes a first polymerization stage, in which a first monomer mixture having a calculated glass transition temperature of at least about 50° C. is polymerized via free radical emulsion polymerization to obtain a first-stage emulsion polymer, and a second polymerization stage, in which a second monomer mixture, having a calculated glass transition temperature from about −30° C. to about 10° C., is polymerized via free radical emulsion polymerization, in the presence of the first-stage emulsion polymer. The dispersions are useful in a variety of coating compositions that exhibit improved block resistance.

The invention discloses a profile control oil-displacement agent for a core-shell type inorganic/organic polymer composite microballoon. A preparation method of the core-shell type inorganic/organic polymer composite microballoon comprises the following steps of carrying out surface modification of inorganic cores of inorganic nano-particles such as silica particles and magnetic particles, and carrying out graft polymerisation by a dispersion polymerization method or an inverse emulsion polymerization method to form polymer shells (such as polyacrylamide cross-linked copolymers) on the surfaces of the inorganic cores. The inorganic components and the organic components bind by chemical bonds so that the core-shell type inorganic/organic polymer composite microballoon has very stale structure. The core-shell type inorganic/organic polymer composite microballoon retains the advantages of polymer microballoons and inorganic particles, and has strong heat-resistant and mineralization-resistant capabilities, high plugging strength and good dilatancy. The core-shell type inorganic/organic polymer composite microballoon can move in rock pores and can plug the rock pores. When a plugging pressure difference is improved to a certain degree, elastic deformation of the core-shell type inorganic/organic polymer composite microballoon can be produced and the deformed core-shell type inorganic/organic polymer composite microballoon sequentially moves to a deep rock stratum part so that a liquid flow direction is changed gradually and a crude oil yield is improved. The profile control oil-displacement agent provided by the invention has a large potential.

The present invention relates to a porous crosslinked hydrophilic polymeric material having cavities joined by interconnecting pores wherein at least some of the cavities at the interior of the material communicate with the surface of the material. The present invention also relates to a process for producing the polymeric material. This process involves combining a hydrophilic monomer phase with an oil discontinuous phase to form an emulsion, and polymerizing the emulsion. The emulsion can be a high internal phase emulsion (i.e., a "HIPE"). The polymeric material can be produced in a variety of forms. In one embodiment the emulsion is suspended in an oil suspension medium, and emulsion droplets are polymerized to produce polymeric microbeads.

Methods for treating a formation penetrated by a wellbore which improves fluid loss control during treatment. In some aspects, the treatments include preparing an aqueous fluid including one or more water inert degradable polymers and an optional viscosifier, injecting the aqueous fluid into the wellbore at a pressure equal to or greater than the formation's fracture initiation pressure, and thereafter injecting into the wellbore a proppant laden fluid at a pressure equal to or greater than the formation's fracture initiation pressure. The water inert degradable polymer may be a polymer such as an emulsion polymer or a latex polymer. Some methods of the invention use a fluid which may have a normalized leak off coefficient (C_w/sqrt(K)) equal to or less than about 0.0022, 0.0014, or 0.0010. A conventional fluid loss additive may or may not be used in conjunction with the treatment fluid and/or the proppant laden fluid. The water inert degradable polymer may or may not substantially enter formation pores. In another aspect, methods for reducing matrix damage to a formation during a treatment operation include preparing an aqueous treatment fluid formed of at least one water inert degradable polymer, and injecting the fluid at a pressure equal or greater than the formation's fracture initiation pressure.

A process for the preparation of a latex polymer consistent with E/A (emulsion/aggregation/coalescence) toner manufacture. The process utilizes a standard (universal) latex composition and involves chain-transfer agent partitioning, emulsion polymerization that provides a latex polymer with a wide range of molecular properties. In particular, the process customizes a wide range Mw (weight average molecular weight) latex, without substantially varying the Mn (number average molecular weight) and hence, without substantially varying Tg (glass transition temperature) such that good toner performance is maintained. In a preferred process, a latex polymer is prepared by mixing a seed particle latex, generated by aqueous emulsion polymerization of a first portion of a monomer emulsion, with a second portion of the monomer emulsion and at least one chain-transfer agent. The mixing is done in the presence of a free-radical initiator and heated, and wherein the monomer emulsion comprises a mixture of polymerization reagents of at least one monomer, at least one chain-transfer agent, at least one surfactant, and water. This process may be applied to core-shell polymerization as well. These latex polymers are ideally suited in the manufacture of toner and developer for electrophotographic imaging and printing.

A method for using a thermoplastic elastomeric composition which contains a multi-staged emulsion polymer binder is provided. An elastomeric composition which contains a multi-staged emulsion polymer binder and a photosensitive composition and a method for using the elastomeric composition in elastomeric coatings, caulks, or sealants is also provided.

The invention relates to a high-sealing polyacrylic ester dispersoid and a preparation method thereof; a multi-element emulsifier system which consists of an anionic emulsifier and a compound non-ionic emulsifier is adopted for controlling the charging process and components of the emulsifier in different polymerization periods, and the room-temperature self-crosslinking high-sealing polyacrylic ester dispersoid is prepared by a semi-continuous seeding emulsion polymerization process. The dispersoid has small particle size, good electrolyte-resistance (calcium ion) stability and high tolerance to various film forming accessory ingredients (various organic solvents with high boiling point). The dispersoid is used as seal coat of water-based wood coating and has good sealing performance to various woods; harmful volatile organic compounds (VOC) such as formaldehyde, and the like sealed against escaping from plates to pollute indoor environment, and the colored compounds such as turpentine, pine oil and tannin and the like are sealed against dissolving out of the plates to pollute pure top coating and white top coating of a water-based wooden ware; and in addition, the dispersoid can be used in water-based leather finishing agents.

A polymerization process comprising initiating a first polymerization of monomers using an initiator functionalized with an ATRP initiating site, wherein the first polymerization is selected from the group of cationic polymerization, anionic polymerization, conventional free radical polymerization, metathesis, ring opening polymerization, cationic ring opening polymerization, and coordination polymerization to form a macroinitiator comprising an ATRP initiating site and further initiating an ATRP polymerization of radically polymerizable monomers using the macroinitiator comprising an ATRP initiating site. Novel block copolymers may be formed by the disclosed method.

The present invention discloses a hollow microsphere preparation method, which uses a hydrogel microsphere as a template. The preparation method is that an emulsion or inverse emulsion polymeric method is adopted to synthesize the hydrogel microsphere with electric charge. A surfactant with inverse electric charge and hydrophobic monomer are added into the hydrogel microsphere suspension, and the hydrogel microsphere is coated by a polymer crust layer of the hydrophobic monomer by a seed emulsion polymerization method to form a core-shell microsphere with an inner layer of hydrogel and an outer layer of polymer; a hydrolyzation of a silicon dioxide or titanium dioxide precursor is used to form the core-shell microsphere with the outer layer of inorganic matter and the inner layer of hydrogel. The core-shell microsphere is dried to obtain the hollow microsphere. The method of the present invention does not need removing the template by organic impregnant dissolving, strong acid or strong alkali etching or high temperature calcining; the preparation process is safe and the operation is simple; and the hollow microsphere with different chemical components can be obtained by changing core or shell.

An oil-based drilling fluid having a polymer latex capable of providing a deformable latex film on at least a portion of a subterranean sand formation has been discovered to inhibit or control fluid loss and act as a sealing agent when used to drill in sand formations for hydrocarbon recovery operations. Typically, the polymer latex is an aqueous suspension of particles formed by emulsion polymerization that is in turn emulsified into a hydrocarbon base fluid. The polymer particles of suitable size precipitate onto the pores of a subterranean sand formation to at least partial seal the formation with a deformable polymer film.

The invention discloses a room temperature self-crosslinking acrylic ester emulsion. The emulsion comprises deionized water, an initiator, an emulsifier, a vinyl aromatic compound, carboxyl-containing olefin monomers, alkyl acrylate unsaturated monomers of C4-C12, methacrylate unsaturated monomers of C4-C20 and functional monomers. The emulsion is prepared with an emulsion polymerization method by adding a pH regulator, a curing agent and a metallic cross linker. The emulsion has the advantages of high glossiness, good abrasive resistance, water resistance and alcohol resistance, has good dryness under high humidity, can be applied to different coating fields and is also suitable for floor wax formulas of polishing-free wax, spray cleaning, cleaning wax polish and the like. The emulsion can be applied to various rigid base materials such as PVC (Polyvinyl Chloride), boards and composite boards and has good balance between detergent resistance and removability.

The invention discloses a nanometer silica sol/acrylic ester composite latex and a preparation method thereof. The composite latex is formed by polymerizing acrylic ester monomers with nanometer silica sol and alkylol solvent; emulsion particles in the composite latex are in a nanometer nucleus-shell structure taking silicon dioxide granules as nucleus and acrylic ester multipolymer as shells; and the preparation method adopts a seed emulsion polymerization method or in situ polymerization method. The composite latex has higher tensile-strength and tearing strength and better performances of acid durability, weather resisting property, wearing resistance, ultraviolet aging resistance, anti-pollution resistance, and the like, can be applied to various aspects of inner and outer wall dope, ground and terrace dope, ground coating of specialty sports fields, and the like, is green and environment-friendly, and has wide market foreground.

The invention discloses a single-component low temperature self-crossing emulsion adhesive for paper and plastic compounds and a preparing method thereof. The raw materials of the self-crossing emulsion adhesive comprise the following components in part by weight: 100-150 parts of de-ionized water, 0.8-3.0 parts of emulsifier, 20-40 parts of nuclear layer monomer, 30-50 parts of interlayer monomer, 20-40 parts of shell layer monomer, and 0.2-0.6 part of initiator. The invention uses a small amount of anionic emulsifier to prepare nuclear emulsion, uses polymerisable emulsifier to prepare interlayer and shell layer pre-emulsion, and adopts semi-continuous seeded low emulsion polymerization process to prepare emulsion particles that have a three-layer core-shell microstructure to obtain the exquisite and stable emulsion. The product has no organic solvent, and does not release methanal, contains no APEO and no phthalate; the film coating has high transparency, high water resistance and high heat and humidity resistance; and the emulsion adhesive is applied to plastic and paper compounds, has high adhesive strength, peel strength and permanent adhesion, is also compatible to oil and ink and has high oil/ink transferring rate.

The present invention relates to paper surface treating agent, and is especially one kind of paper surface sizing agent and its preparation process. The paper surface sizing agent is prepared with cationic monomer, cross-linking monomer, (methyl) acrylate monomer and (methyl) styrene, and through free radical emulsion polymerization in mixture emulsion comprising dispersant, emulsifier and initiator. It has high performance and environment friendship. It is applied in sizing paper surface together with starch to raise the compression strength of paper, raise Cobb value and improve other performance of paper.

A process for preparing polymer dispersions stabilized by polyvinyl alcohol includes a step of emulsion polymerization. The polymerization occurs such that at least 60% of the total conversion occurs at a temperature from 100° C. to 140° C.

The present application discloses a composition comprising a plurality of spherical beads, wherein a radiofrequency chip operating at a frequency of in the range of 2.2-2.7 GHz is embedded within each of said beads and wherein essentially each of said beads is individually identifiable on the basis of radiofrequency identification. Alternatives utilizing a ultrasonic identification chip are also disclosed. The beads are preferably made of polymeric material and can for example be used for the synthesis of e.g. solid-phase chemical libraries. Preferred materials include some that minimise interference in biochemical assays (fouling). The invention also relates to batch and continuous methods of producing such compositions, including emulsion-polymerisation methods. In a further aspect, the present invention relates to an apparatus for analysing radiofrequency-encoded beads. Also provided are methods for detecting and/or analysing and/or sorting beads, as well as methods for processing beads once they have been analysed and/or sorted.

The application describes a mixed olefin polymerization catalyst composition comprising a support, a reaction product of at least one first organometallic compound and a first activator capable of rendering the first organometallic compound active for insertion polymerization, and at least one second organometallic compound, the activator incapable of rendering the second organometallic compound active for polymerization of the monomers. The mixed catalyst composition can be used to prepare a first polymer component in a first polymerization reactor stage and then, when an effective activator is added for the second organometallic compound, the catalyst composition can be used to prepare a second polymer composition that is homogeneously blended with the first polymer component.

A catalyst for the polymerization or copdymerization of olefin is composed of Ti-contained solid component A, organoaluminium compound B and organosilicon compound C. Said A is prepared through dissolving magnesium halide in the mixture of organic epoxy compound, organophosphorus compound and inertial diluent, adding educing agent and magnesium halide or its derivatives to educe out Mg/Ti contained deposit, and carrying a surface modifier, a titanium halide or derivative and an electronic doner. It can be used for the polymerization of propene or copolymerization of propene-ethene.

This invention relates to methods of preparing crosslinked polymer gels useful in subterranean well operations, to compositions comprising such polymers, and to the use of such compositions in treating subterranean formations. In certain exemplary embodiments, the crosslinked polymer gels are produced from emulsion polymerization reactions.