Para tertiary butylphenol formaldehyde resin
Para tertiary butylphenol formaldehyde resin, also known as p-tert-butylphenol-formaldehyde resin (PTBP-FR), is a thermoplastic phenol-formaldehyde resin found in commercial adhesives, particularly glues used to bond leather and rubber. It has broad usage in a large variety of industries and can be found in many household textile products and craft glues.
Source: Wikipedia — Para tertiary butylphenol formaldehyde resin (CC BY-SA 4.0)