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US 2023/0392045 A9Published application
Thermosetting adhesive films
AssigneeZephyros, Inc.
InventorsIra Miller, Michael Czaplicki, Michel Awkal
Life of this patent
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Abstract
Flexible films of thermosetting adhesive materials which are non-tacky to the touch are storage stable at room temperature and can be cured at elevated temperature with a short cure time and can be cured to produce a tough flexible adhesive layer including bonding to oily surfaces, the materials are particularly useful in bonding together dissimilar substrates.
Claims22
1:
- An article comprising:
- a curable thermosetting epoxy resin based adhesive film which is flexible prior to cure and storage stable at room temperature, the adhesive film being derived from a mixture of:
- (a) an elastomer/epoxy resin adduct;
- (b) a core shell material;
- and
- (c) a curing agent.
3 more elements
2:
- The article according to claim 1, wherein the adhesive film is cured in no more than 45 minutes at a temperature no higher than 190° C.
3:
- The article according to claim 1, wherein the adhesive film forms an adhesive bond with oily surfaces and a shear strength of the adhesive film when bonded with the oily surfaces is 90% or more of a shear strength of the adhesive film when bonded to a similar surface free of oil.
4:
- The article according to claim 2, wherein the adhesive film is cured at a temperature in the range of 130° C. to 190° C.
5:
- The article according to claim 1, wherein the adhesive film is foamable and the adhesive film expands to a size at least 50% greater than a size of the adhesive film in an unfoamed state.
6:
- The article according to claim 1, wherein the adhesive film has an uncured thickness between 0.2 and 3.0 mm.
7-9. (canceled)
10:
- The article according to claim 1, wherein the adhesive film contains 5 to 40 wt % of the elastomer/epoxy resin adduct, and 5 to 25 wt % of the core shell material.
11:
- The article according to claim 1, wherein the article is supported by a carrier.
12:
- The article according to claim 11, wherein the carrier is a fibrous carrier or fleece selected from:
- a woven mat, a knit mat, or a random mat;
- and wherein the fibrous carrier or fleece is derived from:
- glass, polyester, polyimide, carbon, or aramid fibres.
1 more element
13:
- The article according to claim 12, wherein the adhesive film is located on opposing sides of the fibrous carrier prior to curing.
14-28. (canceled)
29:
- The article according to claim 1, wherein the adhesive film is thixotropic during a curing of the adhesive film.
30:
- The article according to claim 1, wherein the elastomer/epoxy resin adduct is 40% to 60% elastomer.
31:
- The article according to claim 12, wherein the fibers within the fibrous layer or fleece are unidirectional.
32:
- The article according to claim 11, wherein the adhesive film at least partially impregnates the carrier.
33:
- The article according to claim 1, wherein the article further includes a release liner disposed on the adhesive film so that the article is adapted for reeling and unreeling at room temperature.
34:
- The article according to claim 1, wherein the adhesive film further contains at least one mono-functional epoxy resin.
35:
- The article according to claim 10, wherein the adhesive film further contains 0.5 to 40 wt % of one or more fillers.
36:
- The article according to claim 10, wherein the adhesive film further contains 0.001 to 7 wt % of the curing agent, and the curing agent includes a curing agent accelerator.
37:
- A process for the manufacture of the article of claim 1, comprising:
- (a) extruding the adhesive film at a temperature in the range of 70° C. to 120° C.;
- (b) calendering the adhesive film to a thickness of 0.3 to 2 mm;
- (c) laminating the adhesive film to one or both sides of a fibrous layer;
- and
- (d) cutting the adhesive film into sections of a desired length.
3 more elements
38:
- The process according to claim 37, wherein the extruding is completed by a twin-screw having a plurality of extruder zones and the plurality of extruder zones vary in temperature;
- and wherein the calendering is completed at a temperature in the range of 80° C. to 90° C.