Yellowing resistant psa

Abstract

Provided herein is a pressure sensitive adhesive (PSA) comprising a polycrylate base polymer, a crosslinker and a fluorescer. The crosslinker does not comprise a metal acetylacetonate, a metal alkoxide, or an alkoxy-metal acetylacetonate, and the fluorescer comprises less than 0.1 wt. %metal oxide based on the solid weight of the adhesive. The adhesive is resistant to yellowing under adverse conditions such as high temperature treatment and / or exposure to UV.

Description

technical field [0001] The present disclosure relates generally to pressure sensitive adhesives (PSAs), and more particularly to PSAs having improved resistance to yellowing when exposed to heat and / or UV light / radiation. The present application also relates to labels comprising improved PSAs and methods of producing PSAs and labels. Background technique [0002] PSAs are compositions known to provide adhesion or tack to various substrates when applied at room temperature. This tack provides instant adhesion to the substrate when pressure is applied. PSAs are easy to handle in solid form and usually have a long shelf life, so they are widely used in the manufacture of e.g. self-adhesive labels. [0003] PSA is used in automotive and machinery applications due to its excellent mechanical properties. However, these cars and machines often operate at high temperatures and may be exposed to adverse weather conditions, such as (sun) UV radiation. Conventional PSAs often delet...

AI Technical Summary

Problems solved by technology

[0004]One solution to improve yellowing resistance is to use special polyacrylate base polymers, but this method is expensive and results in Often does not maintain a non-yellow appearance satisfactorily

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