A synthetic polyester of terephthalic acid and butanediol, used as a film former.
What it is
Polybutylene terephthalate is a polyester made from terephthalic acid (1,4-benzenedicarboxylic acid) and 1,4-butanediol, often abbreviated PBT. CosIng lists it as a film-forming and viscosity-controlling ingredient.
Where it is used
Appears on the ingredient lists of a small number of products.
Limits of interpretation
The INCI list shows which ingredients are present, not how much of each. Above 1%, ingredients are listed in descending order of weight; below 1% the order is free.
The INCI name does not show the molecular weight or the physical form, such as powder or fibres.
Functions
- Film forming
- Producing (upon application) a continuous film on the skin, hair or nails.
- Viscosity controlling
- Increasing or decreasing the viscosity (thickness) of cosmetics.
EU regulation
This ingredient is not listed in the annexes of Regulation (EC) No 1223/2009 in the CosIng data.