Method for producing composite fiber components

Patent metadata

Field	Value
Publication number	US-10865283-B2
Application number	US-201716076915-A
Country	US
Kind code	B2
Filing date	Mar 1, 2017
Priority date	Mar 4, 2016
Publication date	Dec 15, 2020
Grant date	Dec 15, 2020

Abstract

The present disclosure relates to sheet moulding compounds (SMC) and to a method for producing composite fiber components from said SMC, based on a polyurethane reaction mixture consisting of (A) at least one aromatic isocyanate component, (B) 70 to 100 wt % of at least one polyol component having at least 70% secondary OH groups, a number average OH count of 15-500 mg KOH/g and functionality of 1.9-2.5, (C) 0-30 wt % of at least one polyol having a number average OH count of 15-500 mg KOH/g and a functionality of 1.9-2.5, (D) as applicable, short-chain polyol, (E) internal separating agent, (F) a thermolatent catalyst, and (G) as applicable, auxiliary and/or additional substances, wherein the PUR reaction mixture has an initial viscosity of 2,500-14,000 mPas at 23° C. and the ratio of NCO groups/OH groups is 1.35:1-10:1.

First claim

The invention claimed is:

1. A process for producing a polyurethane-based fiber composite component part comprising the following process steps:
a) producing a polyurethane reaction mixture;
b) applying the reaction mixture atop at least one of two carrier films;
c) bestowing the reaction mixture on the at least one of the two carrier films with reinforcing fibers;
d) bringing together the two carrier films from c) so that the carrier films on both sides surround the reaction mixture comprising the reinforcing fibers and a sandwich is formed;
e) rolling the sandwich via at least one of rolls and rollers;
g) converting the product from step e) to a desired size and removing the two carrier films;
i) molding and completely curing the product from step g) in a mold to afford the fiber composite component part,

wherein the employed polyurethane reaction mixture consists of the following components:
A) one or more aromatic isocyanate components;
B1) 70% to 100% by weight of one or more polyol components selected from the group consisting of polyether polyols, polyester polyols and polycarbonate polyols having 70% to 100% secondary OH groups based on all of the OH groups in the respective molecule of the polyol components and having a number average OH number of 15 to 500 mg KOH/g and a number-average functionality of 1.9 to 2.5;
B2) 0% to 30% by weight of one or more polyols selected from the group consisting of polyether polyols, polyester polyols and polycarbonate polyols having a number average OH number of 15 to 500 mg KOH/g and a number-average functionality of 1.9 to 2.5 excluding the polyol component B1);

wherein B1) and B2) sum to 100% by weight and at least 70% of the entirety of the OH groups of components B1) and B2) are secondary OH groups;
C) optionally one or more short-chain polyols having a number average OH number of 550 to 2000 mg KOH/g and a number average functionality of 1.9 to 6;
D) one or more internal release agents;
E) one or more thermolatent catalysts catalytically active at temperatures of 50° C. to 120° C.;
F) inorganic fillers; and
G) optionally auxiliary and/or additive substances;

wherein at 23° C. the polyurethane reaction mixture has a starting viscosity of 2500 to 14000 mPas and the ratio of the number of NCO groups of component A) to the number of OH groups of
components B1), B2) and C) is from 1.35:1 to 10:1.

2. The process of claim 1 , wherein step e) further comprises at least one of:
subsequent rolling up of the sandwich to afford a sheet molding compound (SMC); and
subsequent cutting of the sandwich into SMC pieces and stacking of the SMC pieces.

3. The process of claim 2 , further comprising storing the rolled-up SMC or the SMC stack.

4. The process of claim 1 , further comprising stacking a plurality of products from step g).

5. The process of claim 1 , wherein the one or more thermolatent catalysts of component E) are catalytically active at temperatures of 60° C. to 100° C.

Assignees

• Covestro Deutschland Ag

Inventors

• Schornstein Marcel

Classifications

• C08G18/4825 Primary

  Polyethers containing two hydroxy groups (C08G18/4833 - C08G18/5096 take precedence) · CPC title

• C08J5/244

  using glass fibres · CPC title

• C08J5/10

  characterised by the additives used in the polymer mixture · CPC title

• C08G18/7664

  containing alkylene polyphenyl groups · CPC title

• B29C70/545

  Perforating, cutting or machining during or after moulding · CPC title