Polymer Formers - FIZ Karlsruhe

Polymer Indexing
System Description
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Polymer Indexing System Description
Introduction
Since 1966, Polymer information has been indexed in Derwent’s World Patents Index from
patents classified in Section A. The original Plasdoc Code, as it was then known, has undergone
many changes since its introduction. The aim of the system, however, remains the same
and that is to handle polymer information in the patent literature.
The first system was the Plasdoc punch code, and these codes were based upon punch positions
on a punch card. Concepts were represented by groups of these punch codes, but this led
to false drops and poor relevance in searching. In 1978, Key Serial numbers (KS) were created
from precoordinated groups of punch codes. The obvious benefit of these Key Serials
was the ability to search specifically for those concepts to which they had been assigned.
Plasdoc Registry Compounds, with corresponding Registry Numbers (RN) were incorporated
into the system in 1984. These compounds represented the most commonly occurring additives
and catalysts in polymers and allowed them to be searched for specifically.
The most far-reaching changes to the indexing of polymers occurred in 1993, with the introduction
of the Enhanced Polymer Indexing System. This system is based on the hierarchical
structure existing in the previous systems, but has combined the benefits of all of them. Specific
compounds are represented by Specific Compound Numbers, generic codes have been
incorporated within the hierarchical structure to retain the ability to search generically, and
chemical aspects have been introduced to provide the ability to create searches by combining
chemical functional features. Thus, the Enhanced Polymer Indexing System has been designed
for both specific and generic searching of compounds encountered in the polymer area. In
addition, a sophisticated system of linking has been implemented to provide the searching
precision and flexibility required in such a complex technology.