EP-4735550-A1 - PROCESSES FOR MAKING LAMINATED SHEETS

Abstract

One process for making a laminated sheet may comprise applying an uncured adhesive to a removable layer such that a first surface of the removable layer is in direct contact with an uncured adhesive, curing the uncured adhesive to form a cured adhesive layer positioned in direct contact with the first surface of the removable layer, applying a release liner in direct contact with the cured adhesive layer such that the cured adhesive layer is positioned between the removable layer and the release liner. Another process for making a laminated sheet may comprise applying an uncured adhesive to a release liner such that a first surface of the release liner is in direct contact with an uncured adhesive, curing the uncured adhesive to form a cured adhesive layer positioned in direct contact with the first surface of the release liner, and applying a removable layer in direct contact with the cured adhesive layer such that the cured adhesive layer is positioned between the removable layer and the release liner. The release liner may comprise a copolymer comprising low density polyethylene and one or more functionalized polysiloxanes. The functionalized polysiloxanes may be chosen from (meth)acrylic ester functionalized polysiloxane and vinyl functionalized polysiloxane.

Inventors

• NIU, Zhenbin
• KRASOVSKIY, ARKADY L.
• LIU, NANGUO
• DEHLIN, Lori
• VLASAK, Paul R.

Assignees

• Dow Global Technologies LLC
• Dow Silicones Corporation

Dates

Publication Date

20260506

Application Date

20240627

Claims (13)

1. 1. A process for making a laminated sheet, the process comprising: applying an uncured adhesive to a removable layer such that a first surface of the removable layer is in direct contact with an uncured adhesive; curing the uncured adhesive to form a cured adhesive layer positioned in direct contact with the first surface of the removable layer; and applying a release liner in direct contact with the cured adhesive layer such that the cured adhesive layer is positioned between the removable layer and the release liner; wherein the release liner comprises a copolymer comprising low density polyethylene and one or more functionalized polysiloxanes, wherein the functionalized polysiloxanes are chosen from (meth)acrylic ester functionalized polysiloxane and vinyl functionalized polysiloxane.
2. 2. The process of claim 1, wherein: the applying the uncured adhesive to the removable layer is performed as the removable layer is translated in a machine direction; the curing the uncured adhesive is performed as the removable layer is translated in the machine direction; and the applying the release liner in direct contact with the cured adhesive layer is performed as the removable layer is translated in the machine direction.
3. 3. A process for making a laminated sheet, the process comprising: applying an uncured adhesive to a release liner such that a first surface of the release liner is in direct contact with an uncured adhesive; curing the uncured adhesive to form a cured adhesive layer positioned in direct contact with the first surface of the release liner; and applying a removable layer in direct contact with the cured adhesive layer such that the cured adhesive layer is positioned between the removable layer and the release liner; wherein the release liner comprises a copolymer comprising low density polyethylene and one or more functionalized polysiloxanes, wherein the functionalized polysiloxanes are chosen from (meth)acrylic ester functionalized polysiloxane and vinyl functionalized polysiloxane.
4. 4. The method of claim 3, wherein: the applying the uncured adhesive to a release liner is performed as the release liner is translated in a machine direction; the curing the uncured adhesive is performed as the release liner is translated in a machine direction; and the applying the removable layer in direct contact with the cured adhesive layer is performed as the release liner is translated in a machine direction.
5. 5. The process of any preceding claim, wherein the release liner has a homogenous composition.
6. 6. The process of any preceding claim, wherein the removable layer comprises one or more of paper, vinyl, polyester, polypropylene, foil, and fabric.
7. 7. The process of any preceding claim, wherein the process does not include a step of applying a silicone liner.
8. 8. The process of any preceding claim, wherein the cured adhesive is chosen from acrylic adhesives, rubber adhesives, hot melt adhesives, water-based adhesives, solvent-based adhesives, pressure sensitive adhesives, synthetic rubber adhesives, or combinations thereof.
9. 9. The process of any preceding claim, wherein the curing the uncured adhesive is by exposure to heat, radiation, or catalyst.
10. 10. The process of any preceding claim, wherein the copolymer further comprises one or more units derived from a termonomer.
11. 11. The process of any preceding claim, wherein one or both of: the (meth)acrylic ester functionalized polysiloxane is (meth)acrylic ester functionalized polydimethylsiloxane; or the vinyl functionalized polysiloxane is vinyl functionalized polydimethylsiloxane.
12. 12. The process of any preceding claim, wherein the copolymer comprises one or more of the following structures: wherein R is methyl or hydrogen, R 1 is a bridge group that connects functional group ((meth)acrylate) with siloxane, R 2 is an end group selected from the group consisting of alkyl, substituted alkyl, aryl, alkenyl, H, and OH, x is an integer from 10 to 1000, y is an integer from 1 to 30, z is any integer 0 to 30, and y + z is less than or equal to 30.
13. 13. The process of any preceding claim, wherein one or more functionalized polysiloxanes has a structural formula of one or more of the following: where R is methyl or hydrogen, Ri is a bridge group, R2 is an end group selected from alkyl, aryl, alkenyl, H, or OH, x is an integer from 10 to 1000, and y is an integer from 1 to 20.

Description

PROCESSES FOR MAKING LAMINATED SHEETS CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This application claims the benefit of U.S. Provisional Application Serial No. 63/511,044 filed June 29, 2023, the contents of which are incorporated in their entirety herein. TECHNICAL FIELD [0002] The present disclosure generally relates to laminated sheets and, more specifically, to methods for making laminated sheets. BACKGROUND [0003] Taminated sheets have a wide variety of uses in industry. For example, some laminated sheets may selectively removable layers, such as stickers or labels. These stickers or labels may be removed from a backing film as desired by the user and then applied to a substrate. Such laminated sheets can be used for many decorative and functional purposes, and may vary widely in color and design. For example, labels on packaging, foods, or other consumer products are widely utilized in industry. However, new and/or improved methods for making laminated sheets are desired. BRIEF SUMMAR Y [0004] Embodiments of the present disclosure may meet those needs by providing new processes for making laminated sheets which utilize a specialized copolymer composition in the release liner. The laminated films described herein may generally include a release liner, an adhesive, and a removable layer. Such embodiments can be utilized as stickers and/or labels, where the removable layer and adhesive are separated from the release liner. The copolymer composition described herein incorporates a (meth)acrylic ester functionalized polysiloxane. In such embodiments, the release liner may not need a specialized top coating, such as silicone, as is common in conventional embodiments. Instead, the copolymer may have acceptable release characteristics without need for other specialized layers that add cost and complexity to the processes. [0005] According to one or more embodiments of the present disclosure, a process for making a laminated sheet may comprise applying an uncured adhesive to a removable layer such that a first surface of the removable layer is in direct contact with an uncured adhesive, curing the uncured adhesive to form a cured adhesive layer positioned in direct contact with the first surface of the removable layer, applying a release liner in direct contact with the cured adhesive layer such that the cured adhesive layer is positioned between the removable layer and the release liner. The release liner may comprise a copolymer comprising low density polyethylene and one or more functionalized polysiloxanes. The functionalized polysiloxanes may be chosen from (meth)acrylic ester functionalized polysiloxane and vinyl functionalized polysiloxane. [0006] According to one or more additional embodiments of the present disclosure, a process for making a laminated sheet may comprise applying an uncured adhesive to a release liner such that a first surface of the release liner is in direct contact with an uncured adhesive, curing the uncured adhesive to form a cured adhesive layer positioned in direct contact with the first surface of the release liner, and applying a removable layer in direct contact with the cured adhesive layer such that the cured adhesive layer is positioned between the removable layer and the release liner. The release liner may comprise a copolymer comprising low density polyethylene and one or more functionalized polysiloxanes. The functionalized polysiloxanes may be chosen from (meth)acrylic ester functionalized polysiloxane and vinyl functionalized polysiloxane. [0007] These and other embodiments are described in more detail in the Detailed Description. It is to be understood that both the foregoing general description and the following detailed description present embodiments of the technology, and are intended to provide an overview or framework for understanding the nature and character of the technology as it is claimed. The accompanying drawings are included to provide a further understanding of the technology, and are incorporated into and constitute a part of this specification. The drawings illustrate various embodiments and together with the description serve to explain the principles and operations of the technology. Additionally, the drawings and descriptions are meant to be merely illustrative, and are not intended to limit the scope of the claims in any manner. BRIEF DESCRIPTION OF THE DRA WINGS [0008] The following detailed description of specific embodiments of the present disclosure can be best understood when read in conjunction with the following drawings, where like structure is indicated with like reference numerals and in which: [0009] FIG. 1 is a schematic depiction of a flow-chart for a process for making a laminated sheet, according to one or more embodiments disclosed herein; [0010] FIG. 2 is a schematic depiction of a flow-chart for a process for making a laminated sheet, according to one or more embodiments disclosed herein; and [0011] FIG. 3 is a schemat