Epoxy-Functional Polyester Coating for Low-Temperature Impact Resistance
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing adhesive compositions fail to provide adequate impact resistance and lap shear strength across a range of temperatures and substrates, particularly at low temperatures, and often require external energy sources for curing, limiting their practicality and durability.
Innovation Solution
A composition comprising an epoxy-functional polyester derived from a reaction mixture of a polyester, a ring-fused anhydride, and an epoxy, combined with elastomeric particles and an accelerator, which forms a coating with enhanced impact resistance, lap shear strength, and T-peel strength without the need for external curing agents at ambient conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If existing adhesive compositions are used, then they can be applied to substrates, but they fail to provide adequate impact resistance and lap shear strength across a range of temperatures
Solution Approach 1:
The patent uses a composite system combining epoxy-functional polyester resin with rubber particles (including core-shell rubber particles). This composite structure allows the rigid epoxy matrix to provide strength while the rubber particles provide toughness and impact resistance, maintaining performance across temperature ranges from -40°C to 23°C
Solution Approach 2:
The patent modifies the chemical structure by incorporating epoxy-functional groups into the polyester resin through reaction with ring-fused anhydrides and epoxy compounds. This parameter change in molecular structure enables the resin to achieve both high strength and temperature-resistant properties without requiring external curing agents
2Ease of manufacture
If existing adhesive compositions are used, then they can bond substrates, but they require external energy sources for curing, limiting their practicality
Solution Approach 1:
The epoxy-functional polyester resin contains latent curing capability within its molecular structure. The resin can cure autonomously at ambient temperatures through its built-in epoxy-functional groups reacting with appropriate substrates or crosslinking agents, eliminating the need for external energy sources such as UV lamps, heat sources, or moisture activation
Solution Approach 2:
The patent changes the chemical parameters of the resin by incorporating epoxy-functional groups that enable self-curing at ambient conditions. This molecular modification allows the adhesive to transition from requiring external energy input to being able to cure spontaneously under normal environmental conditions
3Strength
If existing adhesive compositions are used, then they can provide basic adhesion, but they fail to maintain lap shear strength and T-peel strength across varying temperatures
Solution Approach 1:
The patent creates a composite adhesive system where epoxy-functional polyester resin provides the bonding matrix and rubber particles (including core-shell structures) provide thermal stability and flexibility. This composite structure maintains lap shear strength greater than 12 MPa and T-peel strength at least 4 N/mm across temperatures from -40°C to 23°C
Solution Approach 2:
The patent incorporates rubber particles with specific properties (core-shell structure, specific glass transition temperatures) at controlled concentrations (0.1-10 parts per hundred resin) into the epoxy-functional polyester matrix. This local addition of specialized components enhances temperature resistance and strength maintenance without compromising the base adhesive properties
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 composition achieves impact resistance greater than 10 N/mm at 23°C and −40°C, lap shear strength greater than 12 MPa, and T-peel strength of at least 4 N/mm, maintaining mechanical properties across varying temperatures without external curing, thus enhancing the durability and applicability of the adhesive.
Implementation Method 1
an epoxy-functional polyester comprising a reaction product of a reaction mixture comprising a polyester, a ring-fused anhydride, and an epoxy; elastomeric particles; and an accelerator
Data Source
AI summary
Disclosed herein are compositions comprising an epoxy-functional polyester, elastomeric particles, and an accelerator. The epoxy-functional polyester comprises a reaction product of a reaction mixture comprising a polyester, a ring-fused anhydride, and an epoxy. The compositions may comprise a sag control agent. Also disclosed are methods of coating a substrate comprising contacting a surface of the substrate with one of the compositions and substrates comprising a coating on a surface thereof, wherein the coating, in an at least partially cured state, has: an impact resistance at 23° C. and/or at −40° C. of greater than 10 N/mm measured according to ISO 11343 using 0.8 mm thick CRS: a lap shear strength of greater than 12 MPa measured according to ASTM D1002 using 0.8 mm thick hot-dip galvanized steel: and/or a T-peel strength at room temperature of at least 4 N/mm measured according to ASTM D1876 using 0.8 mm thick hot-dip galvanized steel.