A scorch-resistant, curable, fluorinated elastomer gum composition is provided. A free-radically curable, fluorinated elastomer gum is compounded with an aliphatically unsaturated, diorganosulfur compound in which at least one of the organo moieties contains a .beta.,.gamma.-aliphatically unsaturated moiety having at least one hydrogen atom bonded to the .alpha. carbon atom of said moiety, said carbon atom being bonded to a sulfur atom of the compound. The diorganosulfur compound reduces the tendency of the compounded fluorinated elastomer gum to scorch, i.e. begin curing prematurely, in the presence of a free-radical curing agent during compounding and shaping of the gum at elevated temperatures below the intended cure temperature. Specific examples of said compounds include 2,5-dihydrothiophene-1,1-dioxide, 2,5-dihydrothiophene-1-oxide, and diallylsulfide. Methods of compounding a fluorinated elastomer gum composition and of shaping and curing such a composition to obtain a fluorinated elastomeric article are also provided.
A thermosetting powdery coating composition which comprises, in admixture: (A) from 40 to 98 parts by weight of a fluorine-containing copolymer, which is a copolymer of a fluoroolefin and a comonomer having a crosslinkable reactive group, e.g., hydroxy, carboxyl, amino and glycidyl groups, containing at least 10% by weight of fluorine and having an intrinsic viscosity of 0.05-2 dl/g (30.degree. C., tetrahydrofuran), a glass transition temperature of 30.degree.-120.degree. C. and a weight loss by heating which does not exceed 2% and (B) from 60 to 2 parts by weight of a curing agent capable of forming crosslinks by reacting with the crosslinkable reactive groups in (A), except for the composition wherein (A) is a hydroxyl group and a weight loss by heating which does not exceed 2% and (B) is a blocked isocyanate compound. The powdery coating composition is excellent in the dispersibility of pigments and efficiency in the coating works therewith and capable of giving a coating film having improved adhesion to a substrate surface, surface luster, impact resistance and insusceptibility to staining.
A thermosetting powder coating composition which contains a resin composition containing (a) 60 to 97 weight % of a fluororesin having reactive group for crosslinking in the molecule which contains 10 weight % or more of fluorine and has glass transition temperature in the range from 35.degree. to 120.degree. C., (b) 3 to 40 weight % of a hardener which can form crosslinking by reaction with the reactive group for crosslinking in the fluororesin (a), (c) 0.01 to 10 weight parts of a synthetic wax or a natural wax based on 100 weight parts of the resin composition and (d) 0.001 to 1.0 weight parts of a material as a coupling agent based on 100 weight parts of the resin composition, forms a coating layer which has the same degree of water repellency and slipping property as those formed from polytetrafluoroethylene powder while the excellent weatherability, acid resistance and adhesion to substrates are retained. A coating layer having excellent adhesive property and impact resistance can be formed therewith on a stainless steel substrate without chemical pretreatment or coating with a primer.
Optical and firescreening protective glazing laminates comprising fluoropolymer interlayer films are described. The films and their laminates comprise THV and blends of THV with FEP, ECTFE or ECCTFE, and modified with additives, such as coupling agents, pigment or color concentrates, and IR- or UV- light blockers, and may be subjected to a surface corona treatment. The films also may incorporate a fiber mesh for additional reinforcement.
Fluorine-containing thermoplastic elastomeric compositions comprising: (A) a continuous phase comprising: (1) about 0 to 90 weight percent of thermoplastic polymer having a melt temperature or glass transition temperature greater than about 150.degree. C., and (2) about 10 to 100 weight percent of block thermoplastic elastomer having a melt temperature greater than about 150.degree. C.; and (B) a disperse phase comprising particles or domains of cured, fluoroelastomer composition. Such compositions are preferably prepared by dynamically vulcanizing the ingredients of the fluorine-containing thermoplastic elastomeric composition.
A composition comprising a fluoropolymer comprising interpolymerized units derived from a nitrogen-containing cure site monomer; and a catalyst composition comprising a compound having the general formula: ##STR1## wherein the group HA is an acid, and each R.sub.1, R.sub.2, and R.sub.3 is, independently, the same or a different C.sub.1 -C.sub.20 alkyl group, a C.sub.3 -C.sub.20 cyclic or heterocyclic group, R.sub.f (CH.sub.2).sub.x --wherein R.sub.f is a C.sub.1 -C.sub.8 linear or branched and at least partially fluorinated alkylene, cycloalkylene, or oxyalkylene, and x is 1 to 4, or a bond to another R group such that the nitrogen is bonded to or part of an imino or heterocyclic group; wherein two or more R groups may be linked to form a cyclic, bicyclic or aromatic group, optionally comprising a heteroatom. Also provided are a method of making a fluoropolymer composition and articles prepared from the compositions.