UV-Curable Acrylic Copolymers for Single-Pass Adhesive Coating

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing pressure sensitive adhesive formulations face challenges in resistance to degradation and aging, particularly in graphics and industrial tape applications, and require solvent-based manufacturing methods that lead to inefficiencies and environmental impact.

Innovation Solution

Development of UV-curable acrylic copolymers that are essentially solvent-free, produced through a method involving polymerization of specific monomer mixtures and reaction with UV-curable functional groups, allowing for single-pass coating and curing to form high-performance adhesive sheets.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If solvent-based manufacturing methods are used for pressure sensitive adhesive formulations, then ease of manufacture is improved, but environmental harm and productivity are worsened due to multiple coating passes and thermal drying requirements

Engineering Contradiction:
Improveease of manufactureVSAvoidproductivity
Core Design Contradiction:
Ease of manufactureVSProductivity

Solution Approach 1:

The patent replaces thermal drying processes with UV curing technology. Instead of using heat to evaporate solvents and dry the adhesive coating, the invention uses UV light to initiate photopolymerization of acrylic monomers, achieving rapid curing without thermal processing. This substitution eliminates the need for multiple coating passes and thermal drying stations, significantly improving productivity while maintaining ease of manufacture through a single-pass coating process

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent changes the curing mechanism from thermal to photchemical. By formulating the adhesive composition with UV-curable acrylic monomers and photoinitiators, the system transitions from heat-based solvent evaporation to light-based polymerization. This parameter change enables single-pass coating and curing, eliminating the productivity bottlenecks associated with traditional multi-pass thermal drying processes

Inventive Principle:
Principle #35Parameter changes

2Productivity

If UV-curable acrylic copolymers are used, then productivity is improved through single-pass coating, but manufacturing precision is challenged by the need for precise monomer composition control

Engineering Contradiction:
ImproveproductivityVSAvoidmanufacturing precision
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The patent performs preliminary formulation work by pre-determining the optimal composition ratios of UV-curable acrylic monomers, copolymerizable monomers, and photoinitiators. By establishing precise formulation specifications before production, the invention enables consistent single-pass coating performance while maintaining control over manufacturing precision. The pre-established formulation parameters guide the coating and curing process to achieve reliable results without requiring complex real-time adjustments

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent transforms the manufacturing approach by changing from solvent-based to UV-curable acrylic copolymer systems. This parameter change enables single-pass coating and curing, dramatically improving productivity. The invention manages the associated manufacturing precision challenges through controlled polymerization reactions and standardized formulation procedures, ensuring consistent adhesive performance despite the complexity of monomer composition control

Inventive Principle:
Principle #35Parameter changes

3Ease of operation

If conventional acrylic adhesives are used, then ease of operation is maintained, but reliability is worsened due to degradation and aging in graphics and industrial tape applications

Engineering Contradiction:
Improveease of operationVSAvoidreliability
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The patent replaces conventional solvent-based acrylic adhesives with UV-curable acrylic copolymer systems. This substitution fundamentally changes the adhesive chemistry from unstable polymer networks to cross-linked structures formed through photopolymerization. The UV-cured adhesive maintains ease of operation through simple single-pass application while achieving superior reliability through enhanced resistance to degradation and aging in graphics and industrial tape applications

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent creates a composite adhesive system combining UV-curable acrylic monomers, copolymerizable monomers with specific glass transition temperatures, and photoinitiators. This composite formulation achieves both ease of operation and high reliability by integrating multiple functional components that work synergistically: the acrylic monomers provide adhesion, the copolymerizable monomers control tack and flexibility, and the photoinitiators enable UV curing to form stable cross-linked networks resistant to degradation

Inventive Principle:
Principle #40Composite materials

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The UV-curable acrylic copolymers exhibit improved adhesive performance with reduced solvent and carbon dioxide emissions, enhancing productivity and reducing waste by eliminating the need for multiple coating passes and thermal drying.

Implementation Method 1

irradiating the layer of the adhesive composition with UV light to form the adhesive sheet

Methodology Applied
Scientific EffectPhotopolymerisation: Photopolymerisation

Data Source

PatentUS20250206994A1UV-curable acrylic copolymers
Publication Date: 2025.06.26 HENKEL KGAA

AI summary

The present invention provides methods for producing a UV-curable acrylic copolymer. The method includes polymerizing a mixture of monomers comprising (i) 40-95 wt % of at a (meth) acrylate monomer, (ii) 5-60 wt % of a copolymerizable monomer, wherein the copolymerizable monomer is selected from those whose homopolymers have a glass transition temperature of higher than −30° C., and (iii) optionally 0.5-20 wt % of a copolymerizable functional monomer having a functional group selected from the group consisting of a hydroxyl group and a carboxyl group to form an acrylic copolymer. The method includes reacting the acrylic copolymer with at least one type of monomer comprising a UV-curable functional group in the presence of a catalyst to form the UV-curable acrylic copolymer. Also encompassed are UV-curable acrylic copolymers thus formed, adhesive composition comprising the UV-curable acrylic copolymers, methods for manufacturing adhesive sheets comprising the UV-curable acrylic copolymers, and use of the UV-curable acrylic copolymers.