According to this article, the main manufacturers of Phthalate are BASF and Exxon.

"Phthalate manufacturers – BASF and ExxonMobil – appear to be the only parties left with an interest in keeping these chemicals in commerce."

https://healthybuilding.net/blog/196-the-end-is-near-for-phthalate-plasticizers

BASF has an interesting history. BASF founded IG Farben and in WWII, "IG Farben also achieved notoriety owing to its production of Zyklon-B, the lethal gas used to murder prisoners in German Nazi extermination camps."

https://en.m.wikipedia.org/wiki/BASF