Two component polyurethane system for casting expanded polytetra

Details Two component polyurethane system for casting expanded polytetra Two component polyurethane system for casting expanded polytetra

1987-12-17

1989-03-21

Welsh, Maurice J.

Synthetic resins or natural rubbers -- part of the class 520 ser

Synthetic resins

From silicon reactant having at least one...

4273935, 4283066, 4283084, 528 48, 528 76, 528 77, 528 83, 528 58, C08G 1861

Patent

active

048144126

ABSTRACT:
The present invention provides a two component polyurethane system with excellent wetting properties for casting a supported or unsupported, expanded polytetrafluoroethylene structure. It consists essentially of a polyisocyanate component having an isocyanate functionality of 2.2 or less and a polyol blend having an overall hydroxyl functionality of 2.2 or less and a viscosity of less than 500 cps., preferably 200 cps. or less. The polyol blend consists essentially of (i) a linear polyether or polyester (about 200-2500 molecular weight), (ii) a diol or triol (less than 200 molecular weight), and (iii) a catalyst in an amount sufficient to provide gelling at greater than 2 minutes and less than 10 minutes. The isocyanate to hydroxyl ratio is between 0.95:1 and 1.10:1. In some cases, it is desirable to include selected siloxane surfactants when polyol blends with the higher viscosities, i.e., about 200-500 cps., are used. The casting system is useful for making membrane filters.

REFERENCES:
patent: 3362921 (1968-01-01), Erhlich et al.
patent: 3663513 (1972-05-01), Kazama et al.
patent: 3697483 (1972-10-01), Damusis
patent: 4131604 (1978-12-01), Szycher
patent: 4131605 (1978-12-01), Ammons
patent: 4131606 (1978-12-01), Ammons
patent: 4243760 (1981-01-01), McDaniel et al.
patent: 4329442 (1982-05-01), Pokorny
patent: 4367327 (1983-01-01), Holker et al.
patent: 4383099 (1983-05-01), Hajimichael et al.
patent: 4745170 (1988-05-01), Bushman et al.

Affiliated with

Also associated with

Rating

Two component polyurethane system for casting expanded polytetra does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Two component polyurethane system for casting expanded polytetra, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Two component polyurethane system for casting expanded polytetra will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-477695