CA-3046410-C - MULTILAYER COMPOSITE MATERIAL AND METHOD FOR MANUFACTURING

Abstract

The invention relates to a multilayer composite comprising a layer of leather in contact with at least one monolayer comprising parallel aligned fibers and a matrix material. The composite may further comprise film layer(s) that may be breathable and/or waterproof. The multilayer composite material is suitable for use in clothing and outdoor gear and apparel.

Inventors

• Wesley Edward Hatcher
• Christopher Michael ADAMS

Assignees

• DSM IP ASSETS B.V.

Dates

Publication Date

20260505

Application Date

20171221

Priority Date

20170124

Claims (5)

1. 13 CLAIMS: 1. A multilayer composite, comprising a layer of leather; in contact with a first monolayer, said first monolayer comprising parallel ultra-high molecular weight polyethylene (UHMWPE) fibers aligned in a first fiber direction and a first matrix material wherein the fiber density in the first monolayer is between 2-30 grams per 5 square meter, wherein the first matrix has a stiffness of at most 2 MPa and whereby the thickness of the leather layer ranges from 0.5-6 mm.
2. 2. The multilayer composite of claim 1 further comprising a second monolayer in contact with the first monolayer, said second monolayer comprising parallel fibers aligned in a 10 second fiber direction and a second matrix material, whereby the first monolayer is rotated relative to the second monolayer in said composite such that the second fiber direction is offset relative to the first fiber direction by up to 90 degrees.
3. 3. The multilayer composite of claim 2, comprising additional monolayers of parallel fibers, each monolayer comprising parallel fibers and a matrix, said monolayers stacked and 15 arranged in said multilayer composite such that one monolayer of the additional monolayers is in contact with the second monolayer, and whereby each successive monolayer is rotated relative to an adjacent monolayer such that fiber directions are offset in each successive layer.
4. 4. The multilayer composite according to claim 2 whereby the fiber density in the second 20 monolayer and additional monolayers is between 2 and 30 grams per square meter. 5. The multilayer composite of any one of claims 1-4, further comprising a polymeric film in contact with a monolayer such as to form an outer layer of the composite. 6. The multilayer composite of claim 5, whereby the film is waterproof/breathable. 7. The multilayer composite of any one of claims 1-6 whereby the strength of the fibers is at 25 least 0.5 GPa. 8. The multilayer composite of any one of claims 1-7 whereby the strength of the fibers is at least 2.
5. 5 GPa. 9. The multilayer composite of any one of claims 1-8 whereby the fibers are UHMWPE fibers with an intrinsic viscosity of at least 5 dl/g. 30 10. The multilayer composite of any one of claims 1-9, whereby at least one matrix material comprises at least one of polyacrylate, polymers functionalized with acrylate groups, and polyurethane. 85327705 14 11. A process for manufacturing a multilayer composite comprising: providing an assembly comprising a layer of leather; at least one monolayer comprising parallel aligned fibers and a matrix material; and optionally at least one polymeric film layer, said assembly having two outer surfaces, one being the layer of leather; and compressing the assembly at a pressure between 1 and 5 bar and temperature between 5 35 and 120 °C, wherein the fiber density in the at least one monolayer is between 2-30 grams per square meter, wherein the matrix has a stiffness of at most 2 MPa and whereby the thickness of the leather layer ranges from 0.5-6 mm. 12. The process according to claim 11, whereby at least one of the outer surfaces is in 10 contact with a cover C during the compressing. 13. The process of claim 12 whereby the cover C has a predefined surface texture or corrugation and is in contact with at least the layer of leather during compression. 14. Use of the multilayer composite of any one of claims 1-10 in the manufacture of footwear, sports apparel, clothing, luggage, leather goods for animals, bags and 15 luggage, hats, jackets, wallets, purses, bags, upholstery and gloves.

Description

MULTILAYER COMPOSITE MATERIAL AND METHOD FOR MANUFACTURING The present invention generally relates to multilayer composite materials usable as ballistic blankets and in particular to a multilayer composite 5 material comprising a layer of leather in contact with a monolayer of man-made fibers and methods for manufacturing same. A ballistic blanket is part of the ballistic gear used around the world in law enforcement and in the military. Ballistic blankets find use, among other things, as 10 coverings for bomb blast protection. Ballistic blankets have been disclosed, for example, by Carter, et al. in U.S. Patent No. 7,389,718. This document discloses a ballistic blanket that encompasses an inner ballistic core encased in an outer housing. The inner ballistic core is covered with an inner cover. The inner ballistic core may be based on high performance fibers such as aramid or ultra-high molecular weight 15 polyethylene ("UHMWPE"). Carter further discloses use of an aramid panel as an inner ballistic core, and that the inner cover may be made of nylon. Further, Carter teaches the outer housing may be made of fabrics, vinyl, leather or other pliable materials. Although this document discloses products with acceptable properties, there is a continuous drive to develop further improved multilayer composite 20 products such as ballistic blankets. In various embodiments of the present disclosure, multilayer composite materials are described having further improvements in strength to weight ratio, reduced thickness, and additional aesthetics. 25 In general, the disclosure provides a multilayer composite comprising: a layer of leather; and a monolayer in contact with the layer of leather. The monolayer may comprise parallel fibers aligned in a single fiber direction along with a matrix material. The monolayer may also be referred to as a unidirectional layer. In some aspects, the multilayer composite may include one or more additional monolayers 30 bonded thereon forming a stack of layers with the leather layer one of the outer layers. Each successive monolayer may be offset relative to an adjacent monolayer at up to 90° such that the parallel fibers in one monolayer are in a different direction relative to the parallel fibers in the adjacent layer. In this way, many monolayers may be used and the fiber direction may never be repeated, or several monolayers may be offset from 35 each other until at some point the fiber direction in a layer repeats with a monolayer further below in the stack. 85327705 2 Each successive monolayer may comprise parallel fibers in a matrix material. The matrix material of each of the monolayers may be of different composition or the same. In various embodiments, a multilayer composite comprising a leather layer and one or more monolayers may further comprise at least one polymeric film in contact with any one monolayer such as to form an outer layer of the composite. In this way, a 5 stack of monolayers may comprise the core of a composite having a leather layer and a film layer as the two exposed outer layers. In various examples, one or more film layers may be waterproof/breathable film, or waterproof and non-breathable film, or any combination of moisture passive and vapor passive. In various embodiments, fibers used in the one or more monolayers may have 10 strength of at least 0.5 GPa. In other examples, fibers may have strength of at least at least 2.5 GPa. Fibers may comprise UHMWPE or some other synthetic fiber. For example, fibers may comprise UHMWPE fibers having an intrinsic viscosity of at least 4 dl/g. Each of the one or more monolayers within the multilayer composite may comprise a matrix material, for example in which the fibers are coated or embedded. Examples 15 of matrix material include polyacrylate, polymers functionalized with acrylate groups, and polyurethane. Matrix material may have a stiffness of at least 3 MPa. The fiber density in any one monolayer may be between 1 and 50 grams per square meter (g/m2 or “gsm”). The present disclosure further provides a process for manufacturing a 20 multilayer composite comprising: providing an assembly comprising a layer of leather; at least one monolayer comprising parallel aligned fibers and a matrix material; and optionally at least one polymeric film layer, the assembly having two outer surfaces, one being the layer of leather; and compressing the assembly at a pressure between 1 and 5 bar, and temperature between 35 and 120 °C. During the compressing process, a cover C may be disposed on one or both of 25 the outer layers, and the cover may be removable from the multilayer composite after the compressing step. Such a cover may have a texturing, and hence the pattern or texture on the cover may be imprinted onto either or both of the outer layers of the composite. The present disclosure further provides a multilayer composite, comprising a layer of leather; in contact with a first monolayer, said first monolayer comprisin