Hierarchy classification:

1. top of the aat hierarchies
2. Materials Facet
3. Materials (hierarchy name)
4. materials (substances)
5. [materials by composition]
6. organic material
7. plastic (material)
8. [plastic by property]
9. thermoset

Anotations

Scope note:

Thermoplastic molding materials prepared from casein, a natural phosphorous-containing protein found in milk. While trying to make a waterproof coating in 1897, Adolph Spitteler and associate W. Krische of Germany discovered that casein becomes hard and insoluble when treated with formaldehyde. Casein plastics were used for small items such as buttons, beads, buckles, combs, fountain pens, umbrella handles, cutlery handles, and knitting needles; they are often pigmented to simulate ivory, horn, or tortoise shell.