摘要:
The process for the scission of high molecular weight perfluoropolyethers having neutral end groups obtained from photo-oxidation processes of perfluoroolefins, or fluorination of hydrogenated polyalkylene oxides, or by polymerization with opening of the partially fluorinated oxetane ring, the scission being carried out in the presence of catalysts selected from the group consisting of fluorides, oxyfluorides and oxides of transition metals, or selected from the group consisting of Al, Sn, and Sb, at temperatures ranging from 150.degree. to 380.degree. C. The scission process leads to the formation of low molecular weight perfluoropolyethers having neutral and acid end groups, the perfluoropolyetheral acids being subjected to conversion reactions in order to obtain functionalized perfluoropolyethers. The products can be used as operative fluids for high vacuum pumps.
摘要:
A process for the dissociation of high molecular weight perfluoropolyethers to obtain low molecular weight perfluoropolyethers which comprises treating a perfluoropolyether with 0.1-10% by weight of a catalyst consisting of Ti, Cr, Mn, Fe, Co, Ni, V, Cu, Mo, Sn, Sb, Zr, Zn oxides at temperatures comprised between 150.degree. and 380.degree. C.
摘要:
A process for decomposing perfluoropolyethers to products with a controlled molecular weight, comprising heating the perfluoropolyethers at temperatures of from 150.degree. to 380.degree. C. with 0.1%-2% by weight of a catalyst comprising a fluoride and/or oxyfluoride of Al, Ti, V, Co or Ni; and in case to fluorination at high temperatures to obtain completely neutral perfluoropolyethers.
摘要:
Perfluoropolyether comprising, besides --CF.sub.2 -- and --CF.sub.2 F.sub.4 units, also a third fluoroalkylene unit containing three or more carbon atoms, said units being connected to each other through --O-ether bridges, and process for obtaining above said polyether, consisting in reacting a mixture of polyperoxidic perfluoropolyether and a fluorinated olefin, in the presence of U.V. radiations.
摘要翻译:除了-CF 2 - 和-CF 2 F 4单元之外,还包括含有三个或更多个碳原子的第三氟代亚烷基单元的全氟聚醚,所述单元通过-O-醚桥相互连接,以及获得上述聚醚的方法, 在UV存在下,聚过氧化全氟聚醚和氟化烯烃的混合物 辐射。
摘要:
A process for the scission of high molecular weight perfluoropolyethers having neutral end groups obtained from photo-oxidation processes of perfluoroolefins, or fluorination of hydrogenated polyalkylene oxides, or by polymerization with opening of the partially fluorinated oxetane ring, said scission being carried out in the presence of catalysts composed of fluorides, oxyfluorides, or oxides of transition metals, or of Al, Sn, Sb, at temperatures ranging from 150.degree. to 380.degree. C.; said scission process leads to the formation of low molecular weight perfluoropolyethers having neutral and acid end groups, the perfluoropolyethereal acids being subjectable to conversion reactions in order to obtain functionalized perfluoropolyethers and to be utilized to provide new polymers.
摘要:
A lubricant composition is disclosed which provides good antiwear characteristics in air at .gtoreq.100.degree. C. and exhibits a low friction coefficient, said composition comprising:(A) a fluorosilicone oil;(B) at least one compound selected from the group consisting of ferrocene, 1,1'-bis(diphenylphosphino) ferrocene and an N,N-disalicylidene-diaminoalkane in which the alkane portion has 3-6 carbon atoms; and(C) at least one phosphorous compound selected from the group consisting of triphenylphosphine, tri-o-tolylphosphine, 1,5-bis-diphenylphosphinopentane and a dialkyldithiophosphate salt in which the alkyl groups have 1-14 carbon atoms, wherein said components (B) and said component (C) is each present at a level of 0.01 to 0.3 percent based on the total weight of said composition.
摘要:
The invention is concerned with silicone copolymer containing terminal and/or pendant oxyalkylene styrene groups which are crosslinkable in the presence of a photoinitiator when exposed to UV radiation and their use in a compositions for coating substrates to provide substrates with anti-adhesive properties.
摘要:
A cotelomer of --CH.sub.2 CF.sub.2 -- (VDF) units and CF.sub.2 CF(CF.sub.3)-- (HFP) units characterized in that the HEP units comprise at least 33% of all VDF and HFP units in the cotelomer combined. Also claimed is a process for preparing a cotelomer in the liquid state comprising reacting (A) a bromine geminal telogen having the general formula RC(R')Br.sub.2 wherein R and R' are selected from the group consisting of F and perfluorinated alkyl radicals having 1 to 8 carbon atoms; (B) 1,1-difluoroethene, and (C) hexafluoropropene, the molar ratio of said components (A):(B):(C) being x:1:1 to x:1:5, in which x is 1 to 5.
摘要:
The invention relates to copolymers of siloxanes with the formula:(R.sub.a).sub.3 SiO(V).sub.v --(W).sub.w --(Y).sub.y --(Z).sub.z --Si(R.sub.a).sub.3whereV=SiR.sub.a R.sub.b O--;W=SiR'.sub.a (R.sub.c --R.sub.d --OCH.dbd.CH.sub.2)O--;Y=SiR.sub.a R.sub.g O--;Z=R.sub.a R.sub.g SiC.sub.n H.sub.2n R'.sub.f C.sub.n H.sub.2n SiR.sub.a R.sub.g O-- where n=2, 3 or 4;v, y, z=0 or an integer, w.noteq.0 with v+y+z.noteq.0;R.sub.a =alkyl or phenyl; R.sub.b =R.sub.a ; R'.sub.a =R.sub.a or alkoxy; R.sub.c =alkylene, for example:R.sub.d =--OCONHR.sub.e NHCO--, --NH--COOC.sub.2 H.sub.4 --, or --NHCOOC.sub.3 H.sub.6 --;R.sub.e =divalent hydrocarbon radicals; R.sub.g, R.sub.f and R'.sub.f are fluorinated or perfluorinated radicals.The above copolymers are used for the preparation of antiadhesive coatings, for example on paper.