The valve member according to one embodiment of the present disclosure is a resin formed product having a crosslinked ethylene-tetrafluoroethylene copolymer as a main component, and having a crosslinking density of 85.0 mol/m.sup.3 or more calculated from a storage modulus at 300° C.

Provided is a dip molding emulsion including, at least: an elastomer that contains a (meth)acrylonitrile-derived structural unit, an unsaturated carboxylic acid-derived structural unit, and a butadiene-derived structural unit in a polymer main chain; an epoxy crosslinking agent; water; and a pH modifier, in which dip molding composition the elastomer contains the (meth)acrylonitrile-derived structural unit in an amount of 20% by weight to 40% by weight, the unsaturated carboxylic acid-derived structural unit in an amount of 1% by weight to 10% by weight, and the butadiene-derived structural unit in an amount of 50% by weight to 75% by weight, and the epoxy crosslinking agent includes an epoxy crosslinking agent containing an epoxy compound having three or more epoxy groups in one molecule and has a dissolution rate in water of 10% to 70% as determined by a specific measurement method.

The present invention discloses a process for providing a cross-linked composition, the process comprising the steps of (a) providing an ethylene-α-olefin plastomer having—a density of from 850 kg/m.sup.3 to 900 kg/m.sup.3; and—an melt flow rate (ISO 1133, 2.16 kg, 190° C.) of 0.3 to 50 g/10 min; (b) grafting the ethylene-α-olefin plastomer with silane crosslinker such that the content of silane crosslinker is in the range of 0.1 to 10.0 wt.-% with respect to the grafted ethylene-α-olefin plastomer; (c) contacting said grafted ethylene-α-olefin plastomer with 2 to 8 wt.-% of a tin-free silane crosslinking catalyst with respect to the resulting mixture of grafted ethylene-α-olefin plastomer and tin-freesilane crosslinking catalyst, wherein said tin-free catalyst comprises a Brönsted acid at 23° C. and 50% relative humidity for at least 15 minutes thus forming a cross-linked composition, wherein gel content of said cross-linked composition after 15 min is at least 60%.

A photocurable silicone composition is disclosed. The composition comprises 4,5,6,7-tetrachloro-3′,6′-dihydroxy-2′,4′,5′,7′-tetraiodospiro[2-benzofuran-3,9′-xanthen]-1-one as a photochromic pigment. The photochromic pigment is present in an amount of from about 0.001 to about 0.05 mass % of a total amount of the composition. The composition can indicate a cure point thereof by disappearance of color.

Provided is a dip molding composition including, at least: an elastomer that contains a (meth)acrylonitrile-derived structural unit, an unsaturated carboxylic acid-derived structural unit, and a butadiene-derived structural unit in a polymer main chain; an epoxy crosslinking agent; water; and a pH modifier, in which dip molding composition the elastomer contains the (meth)acrylonitrile-derived structural unit in an amount of 20 to 40% by weight, the unsaturated carboxylic acid-derived structural unit in an amount of 1 to 10% by weight, and the butadiene-derived structural unit in an amount of 50 to 75% by weight, and the epoxy crosslinking agent includes an epoxy crosslinking agent containing an epoxy compound having three or more epoxy groups in one molecule and has a dissolution rate in water of 10 to 70% as determined by a specific measurement method.

The present invention relates to silane crosslinking catalyst comprising: —75 to 85 wt.-% of an olefin acrylate interpolymer and—15 to 25 wt.-% of a hindered amine light stabilizer (HALS) having a number average molecular weight Mn of 1500 to 4000 g/mol; and—optionally up to 5 wt.-% wax, wherein the silane crosslinking catalyst is free of tin, carboxylic acid(s) and sulphonic acid(s), all weight percentages with respect to the total weight of the silane crosslinking catalyst.

The present invention relates to silane crosslinking catalyst comprising: —75 to 85 wt.-% of an olefin acrylate interpolymer and—15 to 25 wt.-% of a hindered amine light stabilizer (HALS) having a number average molecular weight Mn of 1500 to 4000 g/mol; and—optionally up to 5 wt.-% wax, wherein the silane crosslinking catalyst is free of tin, carboxylic acid(s) and sulphonic acid(s), all weight percentages with respect to the total weight of the silane crosslinking catalyst.

Provided is a dip molding composition including, at least: an elastomer that contains a (meth)acrylonitrile-derived structural unit, an unsaturated carboxylic acid-derived structural unit, and a butadiene-derived structural unit in a polymer main chain; an epoxy crosslinking agent; water; and a pH modifier, in which dip molding composition the elastomer contains the (meth)acrylonitrile-derived structural unit in an amount of 20 to 40% by weight, the unsaturated carboxylic acid-derived structural unit in an amount of 1 to 10% by weight, and the butadiene-derived structural unit in an amount of 50 to 75% by weight, and the epoxy crosslinking agent includes an epoxy crosslinking agent containing an epoxy compound having three or more epoxy groups in one molecule and has a dissolution rate in water of 10 to 70% as determined by a specific measurement method.

A photocurable silicone composition is disclosed. The composition comprises 4,5,6,7-tetrachloro-3′,6′-dihydroxy-2′,4′,5′,7′-tetraiodospiro[2-benzofuran-3,9′-xanthen]-1-one as a photochromic pigment. The photochromic pigment is present in an amount of from about 0.001 to about 0.05 mass % of a total amount of the composition. The composition can indicate a cure point thereof by disappearance of color.

The invention relates to a method for controlling the stress distribution in a material, comprising the steps of: a, preparing a crosslinked polymer containing reversible exchange bonds; b, applying an external force to the crosslinked polymer to cause a certain strain; c, specific region of the crosslinked polymer is selectively heated while maintaining the strain. This method controls and utilizes the internal stresses which are commonly considered as unfavorable. The invention also provides a method for reading information in a polarized light field, wherein the crosslinked polymer treated by the method is transparent under natural light. The information therein can be read only under polarized light, and possesses concealment.