Search

CN-121986145-A - Curable composition

CN121986145ACN 121986145 ACN121986145 ACN 121986145ACN-121986145-A

Abstract

A curable composition comprising A) a radically polymerizable resin comprising at least one (meth) acrylate monomer, at least one (meth) acrylate oligomer, or both, B) a cationically polymerizable resin, C) a free radical photoinitiator, D) a photoacid generator, and E) a polyol, wherein the weight ratio of A to B is from 32:1 to 2:1. The method of using the curable composition includes using it as a dual curable pressure sensitive adhesive with good peel and cohesive strength.

Inventors

  • G. Mihan
  • HERR DONALD
  • MCNEIL CATHY

Assignees

  • 阿科玛法国公司

Dates

Publication Date
20260505
Application Date
20241002
Priority Date
20231009

Claims (17)

  1. 1. A curable composition comprising: A) A free radically polymerizable resin comprising at least one (meth) acrylate monomer, at least one (meth) acrylate oligomer, or both; b) A cationically polymerizable resin; c) A free radical photoinitiator; D) Photoacid generator, and E) A polyol; Wherein the weight ratio of A to B is 32:1 to 2:1.
  2. 2. The curable composition of claim 1, wherein the at least one (meth) acrylate monomer is monofunctional.
  3. 3. The curable composition according to any one of claims 1 or 2, wherein the at least one (meth) acrylate monomer is selected from isobornyl (meth) acrylate (preferably IBOA), alkoxylated tetrahydrofurfuryl (meth) acrylate (preferably THFA), or both.
  4. 4. A curable composition according to any one of claims 1 to 3, wherein the free radically polymerizable resin comprises at least one (meth) acrylate monomer and at least one (meth) acrylate oligomer.
  5. 5. The curable composition according to any one of claims 1 to 4, wherein the cationically polymerizable resin comprises an epoxy resin, preferably a multifunctional (preferably difunctional) epoxy resin.
  6. 6. The curable composition of any one of claims 1 to 5, wherein the photoacid generator is an onium salt, such as a triarylsulfonium salt.
  7. 7. The curable composition of any one of claims 1 to 6, wherein the polyol is aliphatic.
  8. 8. The curable composition of any one of claims 1 to 7, wherein the polyol is a polycaprolactone polyol, a polyether polyol, or a polyester polyol, preferably a polycaprolactone polyol.
  9. 9. The curable composition of any one of claims 1 to 8, wherein the polyol is a polycaprolactone polyol.
  10. 10. The curable composition of any one of claims 1-9, wherein the polyol is a triol or higher functional polyol.
  11. 11. The curable composition of any one of claims 1 to 10, wherein the polyol comprises a polycaprolactone polyol comprising a compound of the structure , Wherein the method comprises the steps of Wherein n is 1 to 10.
  12. 12. A curable composition according to claim 1 to 11, wherein the weight ratio of A to B is 19:1 to 7:3, preferably 11:1 to 4:1, more preferably 6:1 to 4:1, in particular 5:1.
  13. 13. The curable composition of any one of claims 1to 12, wherein the curable composition comprises: 60 to 90 wt%, preferably 65 to 87.5 wt%, more preferably 67.5 to 86 wt% of a free radically polymerizable resin; 2 to 30 wt%, preferably 4 to 27.5 wt%, more preferably 5 to 25 wt% of a cationically polymerizable resin; 0.5 to 8 wt%, preferably 1 to 7 wt%, more preferably 3 to 6 wt% of a free radical photoinitiator; 0.25 to 5% by weight, preferably 0.5 to 4% by weight, more preferably 1 to 3% by weight of a photoacid generator, and From 0.5% to 10%, preferably from 0.75% to 7.5%, more preferably from 1% to 5% by weight of polyol, based on the total weight of the curable composition.
  14. 14. The curable composition of any one of claims 1 to 13 wherein the free radical photoinitiator is sensitive to actinic radiation in a first wavelength range and the photoacid generator is sensitive to actinic radiation in a second wavelength range.
  15. 15. A method of using the curable composition of any one of claims 1-14, the method comprising: applying the curable composition to a first substrate; exposing the curable composition to actinic radiation in a first wavelength range, thereby producing an at least partially cured free radical cured composition; Adhering the free radical cured composition to a second surface, and Before or after the adhering step, exposing the free radical cured composition to actinic radiation in a second wavelength range to produce a dual cured composition.
  16. 16. The method of claim 15, further comprising exposing the dual cure composition to a temperature of 50 o C to 80 o C for a period of 30 minutes to 2 hours.
  17. 17. A method of using the curable composition of any one of claims 1-14, the method comprising: applying the curable composition to a first substrate; Exposing the curable composition to actinic radiation in a first wavelength range to produce an at least partially cured free radical cured composition, and Adhering the free radical cured composition to a second surface, wherein: the free radical photoinitiator is capable of sensitizing the photoacid generator, and The photoacid generator is an iodonium salt.

Description

Curable composition Technical Field Embodiments of the present disclosure relate to actinically curable compositions, and more particularly to curable compositions capable of undergoing a variety of curing mechanisms to provide pressure sensitive adhesives. Background Pressure Sensitive Adhesives (PSAs) allow a user to press the adhesive onto a surface and use the pressure to form a bond without the need for additional heat or energy. In general, PSAs have the advantage of soft, pliable, deformable solids that are safe to use and easy to handle. PSAs are widely used in many industries, including tapes and labels, automotive, electronic, and medical devices. Conventional PSAs contain a variety of different polymer compositions dissolved in a solvent (e.g., water or an organic solvent). One type of PSA is known as an actinically curable PSA. Actinically curable PSAs have attracted attention relative to solvent-based PSAs due to the potential for improved cost, cure efficiency, and overall better environmental footprint. Solvent-based PSAs require a significant amount of time and energy to coat the PSA composition and evaporate the solvent. When organic solvents are used, solvent evaporation creates a type of pollution known as Volatile Organic Compounds (VOCs), thus requiring expensive filtration and solvent recovery mechanisms. Although water-based solvents avoid the VOC problem of organic solvents, water-based solvents require even more energy for the drying process. Historically, actinically curable PSAs have had limited levels of peel and shear strength (i.e., adhesive strength levels similar to typical PSAs). Disclosure of Invention Curable compositions that combine the ease of use of conventional pressure sensitive adhesives, the ease of curing of UV-PSAs, and overcome the problem of insufficient adhesive strength are desired. This need is met by the curable compositions disclosed herein that comprise a free radically polymerizable resin, a cationically polymerizable resin, a free radical photoinitiator, and a photoacid generator. Exemplary embodiments include curable compositions comprising A) a free radically polymerizable resin comprising at least one (meth) acrylate monomer, at least one (meth) acrylate oligomer, or both, B) a cationically polymerizable resin, C) a free radical photoinitiator, D) a photoacid generator, and E) a polyol, wherein the weight ratio of A to B is from 32:1 to 2:1. These and other embodiments are described in more detail throughout this disclosure. The foregoing general description and the following detailed description both provide exemplary embodiments, and provide an overview or framework for understanding the nature and character of the technology. Further, these descriptions are merely illustrative and are not intended to limit the scope of the claims in any way. Detailed Description There is a need in the art for curable compositions that combine the ease of use of pressure sensitive adhesives, the ease of curing of UV-PSAs, and overcome the problem of insufficient adhesive or cohesive strength. One or more embodiments disclosed herein address this need by providing a curable composition comprising a free radically polymerizable resin, a cationically polymerizable resin, a free radical photoinitiator, a photoacid generator, and a polyol. "Actinic light source" refers to an electromagnetic radiation source that produces at least a portion of its electromagnetic radiation in the ultraviolet range (100 nm to 400 nm). The term "aliphatic" refers to saturated and unsaturated hydrocarbons, straight-chain (i.e., unbranched) or branched, cyclic or acyclic, excluding aromatic groups. The term "aliphatic" includes, but is not limited to, alkyl, alkenyl, alkynyl. Thus, illustrative aliphatic groups include, but are not limited to, for example, methyl, ethyl, n-propyl, isopropyl, allyl, n-butyl, sec-butyl, isobutyl, tert-butyl, n-pentyl, sec-pentyl, and the like. Isopentyl, tert-amyl, n-hexyl, sec-hexyl, alkenyl groups such as ethenyl, propenyl, 1-methyl-2-buten-1-yl and alkynyl groups such as ethynyl, 2-propynyl (propargyl) and 1-propynyl. "Cationically polymerizable resin" refers to a resin that forms a polymer in the presence of cations. "Curable composition" refers to a composition that changes properties upon stimulation. Generally, the curable compositions of the present disclosure cure by polymerization and/or crosslinking. Generally, those curable compositions cure upon the addition of energy to the system, which may be in the form of actinic light, heat, or both. In general, when the compounds in the curable composition contain carbon-carbon double bonds, polymerization (curing) involves the reaction of such carbon-carbon double bonds. "Epoxide" refers to a compound, such as a monomer, that contains one or more epoxide groups. The term "photoinitiator" refers to any type of material that forms a material that initiates the reaction and curing of polymeric organic materia