US 12,269,912 B2
Fiber-reinforced molding material and molded article using same
Chikara Yoshioka, Takaishi (JP); and Kazutoshi Hitomi, Takaishi (JP)
Assigned to DIC Corporation, Tokyo (JP)
Appl. No. 17/608,192
Filed by DIC Corporation, Tokyo (JP)
PCT Filed May 1, 2020, PCT No. PCT/JP2020/018378
§ 371(c)(1), (2) Date Nov. 2, 2021,
PCT Pub. No. WO2020/230662, PCT Pub. Date Nov. 19, 2020.
Claims priority of application No. 2019-092878 (JP), filed on May 16, 2019.
Prior Publication US 2022/0227913 A1, Jul. 21, 2022
Int. Cl. C08G 18/04 (2006.01); C08J 5/04 (2006.01); C08J 5/24 (2006.01)
CPC C08G 18/04 (2013.01) [C08J 5/042 (2013.01); C08J 5/243 (2021.05); C08J 2375/04 (2013.01)] 4 Claims
 
1. A fiber-reinforced molding material comprising a thickening substance (A) containing a vinyl ester resin (a1), an unsaturated monomer (a2), a polyisocyanate (a3), a polymerization initiator (a4), and a polymerization inhibitor as essential raw materials and carbon fibers (B) with a fiber length of 2.5 mm to 50 mm, wherein the thickening substance (A) satisfies the following conditions (1) to (3) as measured with a rheometer:
(1) a maximum value of a rate of change in viscosity in a temperature region lower than a temperature Xa indicating a lowest melt viscosity A is 100 Pa·s/° C. to 1,500 Pa·s/° C.,
(2) a maximum value of a rate of change in viscosity in a temperature region higher than or equal to the temperature Xa is 1,000 Pa·s/° C. to 10,000 Pa·s/° C., and
(3) the lowest melt viscosity A is 10 Pa·s to 1,000 Pa·s and the temperature Xa is 70° C. to 140° C.