US 11,718,741 B2
Heat-resistant crosslinked fluororubber formed body and method of producing the same, silane masterbatch, masterbatch mixture, and heat-resistant product
Hiroki Chiba, Tokyo (JP); Masaki Nishiguchi, Tokyo (JP); and Arifumi Matsumura, Tokyo (JP)
Assigned to FURUKAWA ELECTRIC CO., LTD., Tokyo (JP)
Filed by FURUKAWA ELECTRIC CO., LTD., Tokyo (JP)
Filed on May 28, 2020, as Appl. No. 16/886,427.
Application 16/886,427 is a continuation of application No. PCT/JP2019/027163, filed on Jul. 9, 2019.
Claims priority of application No. 2018-131048 (JP), filed on Jul. 10, 2018.
Prior Publication US 2020/0291216 A1, Sep. 17, 2020
Int. Cl. C08L 27/16 (2006.01); C08K 3/22 (2006.01); C08K 3/26 (2006.01); C08K 3/36 (2006.01); C08K 5/14 (2006.01); C08L 23/26 (2006.01); C08L 27/18 (2006.01); C08L 51/04 (2006.01)
CPC C08L 27/16 (2013.01) [C08K 3/22 (2013.01); C08K 3/26 (2013.01); C08K 3/36 (2013.01); C08K 5/14 (2013.01); C08L 23/26 (2013.01); C08L 27/18 (2013.01); C08L 51/04 (2013.01); C08K 2003/2296 (2013.01); C08K 2003/265 (2013.01); C08L 2201/08 (2013.01); C08L 2203/206 (2013.01); C08L 2310/00 (2013.01); C08L 2312/08 (2013.01)] 20 Claims
 
1. A method of producing a heat-resistant crosslinked fluororubber formed body, including the following steps (1), (2) and (3):
Step (1): a step of obtaining a reaction composition containing a silane crosslinkable rubber by melt-mixing, with respect to 100 parts by mass of a base rubber containing 60 to 99% by mass of a fluororubber and 1 to 40% by mass of an ethylene-based copolymer resin modified with an unsaturated carboxylic acid, 0.003 to 0.5 parts by mass of an organic peroxide, 0.5 to 400 parts by mass of an inorganic filler, 2 to 15 parts by mass of a silane coupling agent having a grafting reaction site that is capable of being subjected to a grafting reaction with said base rubber in the presence of radicals generated from said organic peroxide, and a silanol condensation catalyst,
Step (2): a step of obtaining a formed body by forming the reaction composition, and
Step (3): a step of obtaining the heat-resistant crosslinked fluororubber formed body by bringing the formed body into contact with water,
wherein, when the step (1) is performed,
in a case of melt-mixing all of the base rubber in the following step (a), the step (1) includes the following step (a) and step (c), or in a case of melt-mixing a part of the base rubber in the following step (a), the step (1) includes the following step (a), step (b) and step (c), and
the ethylene-based copolymer resin modified with an unsaturated carboxylic acid is melt-mixed in at least one of the following steps (a) and (b):
Step (a): a step of preparing a silane masterbatch containing a silane crosslinkable rubber, by melt-mixing all or part of the base rubber, the organic peroxide, the inorganic filler and the silane coupling agent at a temperature equal to or higher than a decomposition temperature of said organic peroxide, and by graft-reacting the grafting reaction site and the base rubber due to radicals generated from said organic peroxide,
Step (b): a step of preparing a catalyst masterbatch, by melt-mixing a remainder of the base rubber, and the silanol condensation catalyst, and
Step (c): a step of obtaining the reaction composition, by melt-mixing the silane masterbatch and the silanol condensation catalyst or the catalyst masterbatch.