<?xml version="1.0" encoding="utf-8"?><rdf:RDF  xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"  xmlns:rdfs="http://www.w3.org/2000/01/rdf-schema#"  xmlns:skos="http://www.w3.org/2004/02/skos/core#"  xmlns:map="http://www.w3c.rl.ac.uk/2003/11/21-skos-mapping#"  xmlns:dct="http://purl.org/dc/terms/"  xmlns:dc="http://purl.org/dc/elements/1.1/"><skos:ConceptScheme rdf:about="http://AATesaurus.cultura.gencat.cat/aat/getty_en">  <dc:title>Tesaurus d&apos;Art i Arquitectura</dc:title>  <dc:creator>Getty Institute</dc:creator>  <dc:contributor></dc:contributor>  <dc:publisher></dc:publisher>  <dc:rights></dc:rights>  <dc:subject></dc:subject>  <dc:description><![CDATA[  ]]></dc:description>  <dc:date>0000-00-00</dc:date>  <dct:modified>2024-01-24 15:40:44</dct:modified>  <dc:language>en</dc:language>  </skos:ConceptScheme>  <skos:Concept rdf:about="http://AATesaurus.cultura.gencat.cat/aat/getty_en?tema=31370945"><skos:prefLabel xml:lang="en">casein plastic</skos:prefLabel><skos:notation>300014532</skos:notation><skos:altLabel xml:lang="en">Aladdinite</skos:altLabel><skos:altLabel xml:lang="en">casein plastics</skos:altLabel><skos:altLabel xml:lang="en">Karolith</skos:altLabel><skos:altLabel xml:lang="en">Lactoid</skos:altLabel><skos:altLabel xml:lang="en">milkstone</skos:altLabel><skos:altLabel xml:lang="en">plastic, casein</skos:altLabel><skos:altLabel xml:lang="en">plastics, casein</skos:altLabel> <skos:scopeNote xml:lang="en">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.</skos:scopeNote><skos:inScheme rdf:resource="http://AATesaurus.cultura.gencat.cat/aat/getty_en"/><skos:broader rdf:resource="http://AATesaurus.cultura.gencat.cat/aat/getty_en?tema=31340156"/><skos:exactMatch> <skos:Concept rdf:about="http://AATesaurus.cultura.gencat.cat/aat/getty_ca/index.php?tema=9846783"> <skos:prefLabel xml:lang="ca">plàstic de caseïna</skos:prefLabel> </skos:Concept></skos:exactMatch><skos:exactMatch> <skos:Concept rdf:about="http://AATesaurus.cultura.gencat.cat/aat/getty_es/index.php?tema=14084043"> <skos:prefLabel xml:lang="es">plástico de caseína</skos:prefLabel> </skos:Concept></skos:exactMatch>  <dct:created>2026-03-30 20:40:02</dct:created>  </skos:Concept></rdf:RDF>