A method for producing low-molecular-weight polytetrafluoroethylene containing a reduced amount of C4-C16 perfluorocarboxylic acids and salts thereof, as well as a powder containing low-molecular weight polytetrafluoroethylene, the method including (1) irradiating polytetrafluoroethylene containing a C4-C16 perfluorocarboxylic acid or any salt thereof and having a heat-of-fusion reduction of 40% or lower between first heating and second heating in differential scanning calorimetry with radiation to a dose of 5 to 1000 kGy substantially in the absence of oxygen at a temperature of lower than 100° C. to provide low-molecular-weight polytetrafluoroethylene containing a reduced amount of the perfluorocarboxylic acid and any salt thereof and having a melt viscosity at 380° C. of 1.0×10.sup.2 to 7.0×10.sup.5 Pa.Math.s.

A method for producing low molecular weight polytetrafluoroethylene having a melt viscosity at 380° C. of 1.0×10.sup.2 to 7.0×10.sup.5 Pa.Math.s. The method includes: (1) irradiating high molecular weight polytetrafluoroethylene with radiation in the presence of a substance capable of generating a free hydrogen atom and decomposing the high molecular weight polytetrafluoroethylene into a low molecular weight component; and (2) deactivating at least part of main-chain radicals and end radicals generated by the irradiation and providing the low molecular weight polytetrafluoroethylene. Also disclosed is a composition containing the low molecular weight polytetrafluoroethylene and a low molecular weight polytetrafluoroethylene.

A method for producing low molecular weight polytetrafluoroethylene having a melt viscosity at 380° C. of 1.0×10.sup.2 to 7.0×10.sup.5 Pa.Math.s. The method includes: (1) irradiating high molecular weight polytetrafluoroethylene with radiation in the presence of a substance capable of generating a free hydrogen atom and decomposing the high molecular weight polytetrafluoroethylene into a low molecular weight component; and (2) deactivating at least part of main-chain radicals and end radicals generated by the irradiation and providing the low molecular weight polytetrafluoroethylene. Also disclosed is a composition containing the low molecular weight polytetrafluoroethylene and a low molecular weight polytetrafluoroethylene.

The invention relates to a method for manufacturing low-molecular-weight polytetrafluoroethylene, comprising: a) a first step of mixing high-molecular-weight polytetrafluoroethylene with at least one additive selected from the group consisting of ethers having formula R.sup.1—O—R.sup.2, wherein R.sup.1 and R.sup.2 are independently selected among C.sub.1-C.sub.10 straight or branched aliphatic group, C.sub.4-C.sub.10 alicyclic or heterocyclic groups, C.sub.5-C.sub.10 aromatic or heteroaromatic groups; (per)fluorinated vinyl ethers; (per)fluorinated olefins; and optionally substituted aromatic hydrocarbons, and b) a second step of irradiating the so obtained mixture with ionizing radiation, said second step b) being carried out substantially in the absence of oxygen.

The invention relates to a method for manufacturing low-molecular-weight polytetrafluoroethylene, comprising: a) a first step of mixing high-molecular-weight polytetrafluoroethylene with at least one additive selected from the group consisting of ethers having formula R.sup.1—O—R.sup.2, wherein R.sup.1 and R.sup.2 are independently selected among C.sub.1-C.sub.10 straight or branched aliphatic group, C.sub.4-C.sub.10 alicyclic or heterocyclic groups, C.sub.5-C.sub.10 aromatic or heteroaromatic groups; (per)fluorinated vinyl ethers; (per)fluorinated olefins; and optionally substituted aromatic hydrocarbons, and b) a second step of irradiating the so obtained mixture with ionizing radiation, said second step b) being carried out substantially in the absence of oxygen.

The invention relates to a method for manufacturing low-molecular-weight polytetrafluoroethylene, comprising: a) a first step of mixing high-molecular-weight polytetrafluoroethylene with at least one additive selected from the group consisting of ethers having formula R.sup.1—O—R.sup.2, wherein R.sup.1 and R.sup.2 are independently selected among C.sub.1-C.sub.10 straight or branched aliphatic group, C.sub.4-C.sub.10 alicyclic or heterocyclic groups, C.sub.5-C.sub.10 aromatic or heteroaromatic groups; (per)fluorinated vinyl ethers; (per)fluorinated olefins; and optionally substituted aromatic hydrocarbons, and b) a second step of irradiating the so obtained mixture with ionizing radiation, said second step b) being carried out substantially in the absence of oxygen.

Provided is a method for producing a fluoropolymer, the method including a polymerizing step of polymerizing tetrafluoroethylene in an aqueous medium in the presence of an initiator, a chain transfer agent, and a surfactant to provide a fluoropolymer containing more than 80 mol % of a polymerized unit based on tetrafluoroethylene, the chain transfer agent including at least one selected from the group consisting of a dithioester compound, a dithiocarbamate compound, a trithiocarbonate compound, and a xanthate compound. Also provided is a fluoropolymer represented by the formula Af-CRP defined in the description.

A composition of the present disclosure includes an aqueous dispersion of epoxy resin particles. The epoxy resin particles include at least two 1,2-epoxide groups. The composition further includes one or more anti-adhesive agents, one or more anti-microbial agents, or a combination of one or more anti-adhesive agents and one or more anti-microbial agents.

A composition of the present disclosure includes an aqueous dispersion of epoxy resin particles. The epoxy resin particles include at least two 1,2-epoxide groups. The composition further includes one or more anti-adhesive agents, one or more anti-microbial agents, or a combination of one or more anti-adhesive agents and one or more anti-microbial agents.

A method for producing a fluoropolymer which includes polymerizing a fluoromonomer in an aqueous medium in the presence of a surfactant to provide a fluoropolymer, the surfactant being represented by the general formula (1): CR.sup.1R.sup.2R.sup.4—CR.sup.3R.sup.5—X-A, wherein R.sup.1 to R.sup.5 are each H or a monovalent substituent, with the proviso that at least one of R.sup.1 and R.sup.3 represents a group represented by the general formula: —Y—R.sup.6 and at least one of R.sup.2 and R.sup.5 represents a group represented by the general formula: —X-A or a group represented by the general formula: —Y—R.sup.6; and A is the same or different at each occurrence and is —COOM, —SO.sub.3M, or —OSO.sub.3M. Also disclosed is a surfactant for polymerization represented by the general formula (1), a method for producing a fluoropolymer using the surfactant and a composition including a fluoropolymer and the surfactant.