In-situ polymerized type thermoplastic prepreg, thermoplastic composite, and methods of manufacturing the same

Patent metadata

Field	Value
Publication number	US-2018346672-A1
Application number	US-201615780048-A
Country	US
Kind code	A1
Filing date	Nov 18, 2016
Priority date	Dec 1, 2015
Publication date	Dec 6, 2018
Grant date	—

Abstract

An in-situ polymerized type thermoplastic prepreg is provided, which is excellent in productivity, has tack properties and drape properties that allow easy shaping in a mold, is excellent in handling properties, and allows a molded product obtained by curing to have both mechanical properties as high as those of a thermosetting composite and the features of the thermoplastic composite. An in-situ polymerized type thermoplastic prepreg 1 includes reinforcing fibers 2 and an in-situ polymerized type thermoplastic epoxy resin 3 as a matrix resin. The in-situ polymerized type thermoplastic epoxy resin 3 is cured to B-stage, with the weight-average molecular weight being 6,000 or less, and has tack properties and drape properties at 30° C. or less, and the in-situ polymerized type thermoplastic epoxy resin after curing has a weight-average molecular weight of 30,000 or more.

First claim

1 . An in-situ polymerized type thermoplastic prepreg comprising reinforcing fibers and an in-situ polymerized type thermoplastic epoxy resin as a matrix resin,
wherein the in-situ polymerized type thermoplastic epoxy resin is cured to B-stage, with a weight-average molecular weight being not more than 6,000, and has tack properties and drape properties at not more than 30° C., and wherein the in-situ polymerized type thermoplastic epoxy resin after curing has a weight-average molecular weight of not less than 30,000 and exhibits thermoplasticity.

2 . The in-situ polymerized type thermoplastic prepreg according to claim 1 , wherein the uncured in-situ uncured polymerized type thermoplastic epoxy resin comprises
(a) a first bifunctional compound having two epoxy groups, and (b) a second bifunctional compound having two functional groups of at least one type selected from the group consisting of a phenolic hydroxyl group, an amino group, a carboxyl group, a mercapto group, an isocyanate group, and a cyanate ester group.

3 . The in-situ polymerized type thermoplastic prepreg according to claim 1 , wherein the in-situ polymerized type thermoplastic epoxy resin has a resin content ratio of 20 wt % to 40 wt %.

4 . The in-situ polymerized type thermoplastic prepreg according to any one of claim 1 , wherein the reinforcing fibers have a weight per unit area of 50 g/m 2 to 500 g/m 2 .

5 . The in-situ polymerized type thermoplastic prepreg according to claim 1 , wherein the reinforcing fibers have a tensile modulus of more than 40 GPa and are unidirectional continuous fibers paralleled in one direction.

6 . A thermoplastic composite obtained by curing an in-situ polymerized type thermoplastic prepreg defined in claim 1 , wherein the cured in-situ polymerized type thermoplastic epoxy resin has a weight-average molecular weight of not less than 30,000 and exhibits thermoplasticity.

7 . A method of manufacturing an in-situ polymerized type thermoplastic prepreg comprising reinforcing fibers and an in-situ polymerized type thermoplastic epoxy resin as a matrix resin, the method comprising:
(a) preparing an in-situ polymerized type thermoplastic epoxy resin comprising a first bifunctional compound having two epoxy groups, a second bifunctional compound having two functional groups of at least one type selected from the group consisting of a phenolic hydroxyl group, an amino group, a carboxyl group, a mercapto group, an isocyanate group, and a cyanate ester group, and a catalyst; (b) preparing a resin film by uniformly applying the prepared in-situ polymerized type thermoplastic epoxy resin onto a release sheet while adjusting a temperature of the resin within a range of 40° C. to 70° C.; (c) performing a polymerization reaction to cure the resin film on the release sheet to B-stage, with a weight-average molecular weight of the in-situ polymerized type thermoplastic epoxy resin being not more than 6,000, while maintaining a temperature of the resin film at 20° C. to 40° C. for 50 hr to 240 hr; and (d) impregnating the in-situ polymerized type thermoplastic epoxy resin in B-stage as a matrix resin into reinforcing fibers.

8 . A method of manufacturing an in-situ polymerized type thermoplastic prepreg comprising reinforcing fibers and an in-situ polymerized type thermoplastic epoxy resin as a matrix resin, the method comprising:
(a) preparing an in-situ polymerized type thermoplastic epoxy resin comprising a first bifunctional compound having two epoxy groups, a second bifunctional compound having two functional groups of at least one type selected from the group consisting of a phenolic hydroxyl group, an amino group, a carboxyl group, a mercapto group, an isocyanate group, and a cyanate ester group, and a catalyst; (b) performing a polymerization reaction to cure the prepared in-situ polymerized type thermoplastic epoxy resin to B-stage, with a weight-average molecular weight of the in-situ polymerized type thermoplastic epoxy resin being not more than 6,000, while maintaining a temperature of the resin at 20° C. to 40° C. for 50 hr to 240 hr; (c) preparing a resin film by uniformly applying the in-situ polymerized type thermoplastic epoxy resin polymerized to B-stage onto a release sheet while adjusting a temperature of the resin within a range of 40° C. to 80° C.; and (d) impregnating the in-situ polymerized type thermoplastic epoxy resin in B-stage as a matrix resin into reinforcing fibers.

9 . The method of manufacturing an in-situ polymerized type thermoplastic prepreg according to claim 7 , wherein the catalyst comprises imidazole-based catalysts including 1,2-alkylenebenzimidazole (TBZ) and 2-aryl-4,5-diphenylimidazole (NPZ), aliphatic polyamine-based catalysts including diethylene triamine and menthane diamine, aromatic amine-based catalysts including diaminodiphenyl sulfone, and phosphorus-based catalysts.

10 . The method of manufacturing an in-situ polymerized type thermoplastic prepreg according to claim 7 , wherein the in-situ polymerized type thermoplastic epoxy resin has a viscosity of 100 Pa·s to 1,000 Pa·s at 25° C. before polymerization.

11 . The method of manufacturing an in-situ polymerized type thermoplastic prepreg according to claim 7 , wherein the in-situ polymerized type thermoplastic epoxy resin has a resin content ratio of 20 wt % to 40 wt %.

12 . The method of manufacturing an in-situ polymerized type thermoplastic prepreg according to claim 7 , wherein the reinforcing fibers have a weight per unit area of 50 g/m 2 to 500 g/m 2 .

13 . The method of manufacturing an in-situ polymerized type thermoplastic prepreg according to claim 7 , wherein the reinforcing fibers comprise uni-directional continuous fibers having a tensile modulus of not less than 40 GPa and paralleled in one direction.

14 . A method of manufacturing a thermoplastic composite, the method comprising laminating a plurality of in-situ polymerized type thermoplastic prepregs prepared by a method of manufacturing an in-situ polymerized type thermoplastic prepreg defined in claim 7 , and then heating and curing the prepregs until the in-situ polymerized type thermoplastic epoxy resin has a weight-average molecular weight of not less than 30,000.

15 . The method of manufacturing a thermoplastic composite according to claim 14 , wherein a laminated body of the in-situ polymerized type thermoplastic prepregs is heated and pressurized at a temperature of 100° C. to 200° C. and a pressure of 1 atm to 10 atm.

16 . The method of manufacturing a thermoplastic composite according to claim 14 , wherein the in-situ polymerized type thermoplastic epoxy resin after being heated/cured and polymerized has a glass-transition point of 90° C. to 150° C. and a melting point of 130° C. to 200° C.

Assignees

• Nippon Steel & Sumikin Mat Co

Inventors

• Eto Kazuya
• Nobuzawa Yuki
• Kurata Isao
• Murakami Shinkichi

Classifications

• C08G59/688

  containing phosphorus · CPC title

• C08J2363/00

  Characterised by the use of epoxy resins; Derivatives of epoxy resins · CPC title

• C08J5/042 Primary

  with carbon fibres · CPC title

• C08J5/24 Primary

  Impregnating materials with prepolymers which can be polymerised in situ, e.g. manufacture of prepregs · CPC title

• C08J2300/22

  Thermoplastic resins · CPC title