US 6,039,821 A · Bonding fibrous batts with thermosetting fiber-binders of certain epoxy resins

Abstract

A process is described for producing a bonded, non-woven fibrous batt by the use of a dry, solid, particulate, latent-cross-linkable, thermosetting, fiber-binder. This fiber-binder is an intimate mixture of a solid epoxy resin and a cross-linking agent. The epoxy resin has (a) terminal epoxy groups; (b) an epoxide equivalent weight of above about 500; (c) a glass transition temperature above about 40.degree. C.; and (d) a melting point above about 70.degree. C. In the process the fiber-binder contacts the fibers to form a raw batt with the fiber-binder loosely adhering to the fibers of the batt. Then the raw batt is heated to a cross-linking temperature above the melting point of the fiber-binder but below the scorching or melting point of the fibers thereby melting the fiber-binder. The fiber-binder flows to intersections of the fibers and subsequently reacts the cross-linking agent with the terminal epoxy groups of the epoxy resin. This converts the raw batt into a hot cross-linked batt. The hot cross-linked batt is then cooled to room temperature. Batts are also described as is a process for hot molding these batts.

Claims35

Dependent claims

A dry process for producing a bonded, non-woven, batt of fibers comprising the steps of:

I. providing a dry, solid, particulate, B-stage, fiber-binder comprising:
A. a solid epoxy resin having:
(a) an epoxide equivalent weight of above about 500;
(b) a glass transition temperature above about 40.degree. C.
(c) a melting point above about 70.degree. C.;
and
B. a coreactive effective amount of at least one cross-linking agent which reacts with the epoxide groups of the epoxy resin;
and then
II. contacting fiber-binding amounts of the fiber-binder with the fibers to form a raw batt with the fiber-binder loosely adhering to the fibers of the batt;
and then
III. heating the raw batt to a cross-linking temperature above the melting point of the fiber-binder but below the scorching or melting point of the fibers thereby melting the fiber-binder whereupon the fiber-binder flows to intersections of the fibers and subsequently the cross-linking agent reacts with the epoxide groups of the epoxy resin thereby converting the raw batt into a hot cross-linked batt;
and then
IV. cooling the hot cross-linked batt.

10 more elements

A dry process for producing a bonded, non-woven, batt of fibers comprising the steps of:

I. providing a dry, solid, particulate, B-stage, fiber-binder comprising:
A. a solid epoxy resin having:
(a) an epoxide equivalent weight of above about 500;
(b) a glass transition temperature above about 40.degree. C.;
(c) a melting point above about 70.degree. C.;
and
B. a coreactive effective amount of at least one cross-linking agent which reacts with the epoxide groups of the epoxy resin;
and then
II. contacting fiber-binding amounts of the dry fiber-binder with the fibers to form a raw batt with the fiber-binder loosely adhering to the fibers of the batt;
and then
III. heating the raw batt briefly to a cross-linking temperature above the melting point of the fiber-binder but below the scorching or melting point of the fibers thereby melting the fiber-binder whereupon the fiber-binder flows to intersections of the fibers and a portion of the cross-linking agent reacts with a portion of the epoxide groups of the epoxy resin thereby converting the raw batt into a hot batt;
and then
IV. cooling the hot batt;
and then
V. placing the batt between open male and female molds, and then
VI. closing the open male and female molds having the semi-cured batt therebetween, thereby causing the batt to take the form of the male mold and the female mold;
and then
VII. heating the male mold, the female mold, and the batt to a cross-linking temperature above the melting point of the fiber-binder but below the scorching or melting point of the fibers thereby melting the fiber-binder and reacting the cross-linking agent with the remaining epoxide groups of the epoxy resin thereby converting the B-stage resin to a C-stage resin and converting the batt into a shaped article composed of a fully cross-linked batt.

15 more elements

A dry process for producing a bonded, non-woven, batt of fibers comprising the steps of:

I. providing a dry, solid, particulate, partially cross-linked, fiber binder comprising:
A. a solid epoxy resin of Formula III, ##STR9## wherein "q" is equal to 3 to 7, and each "p" is independently selected from the group consisting of zero and one, said epoxy resin having epoxide groups of Formula I;
##STR10## wherein the epoxy resin has an epoxide equivalent weight between about 600 and about 3,000;
and
wherein the epoxy resin is substantially linear with a functionality of about 2;
and
wherein the epoxy resin has a glass transition temperature above about 50.degree. C.;
and
B. trimellitic anhydride as a cross-linking agent;
and
C. calcium carbonate present in an amount from about one to about 60% by weight of a particulate inorganic filler based on the weight of the fiber-binder;
wherein the fiber-binder is free from solvents for the epoxy resin and for the cross-linking agent;
and
wherein the fiber-binder is anhydrous;
and
wherein the fiber-binder has a softening point of about 80 to about 120.degree. C.;
wherein the fiber-binder has a glass plate Low of about 35 to about 125 mm;
and
wherein the fiber-binder, the epoxy resin and the cross-linking agent are substantially coreacted only to the extent that fewer than twenty percent of the epoxide groups are reacted with the cross-linking agent;
wherein the fiber-binder is in the B-stage;
and
wherein the fiber-binder has a particle size from about 5 to 50 microns;
and
wherein the equivalent ration, A:B of (A) the epoxy resin to (B) the cross-linking agent, is from about 1.3:1 to about 1:1.3;
and then
II. contacting fiber-binding amounts of the dry fiber-binder with the fibers to form a raw batt with the fiber-binder loosely adhering to the fibers of the batt;
wherein the fiber-binder comprises from about 2 to about 40 weight percent based on the combined weight of the fibers and the fiber-binder;
and then
III. heating the raw batt to a temperature of about 100.degree. C. to about 240.degree. C. for one to five minutes whereupon the fiber-binder flows to intersections of the fibers and whereupon the trimellitic anhydride reacts with the epoxide groups of the epoxy resin thereby converting the raw batt into a hot cross-linked batt;
and
IV. cooling the hot cross-linked batt.

28 more elements

Dependencies are inferred from the claim text.

Bonding fibrous batts with thermosetting fiber-binders of certain epoxy resins

Life of this patent

Bonding fibrous batts with thermosetting fiber-binders of certain epoxy resins

Life of this patent

Abstract

Claims35