Analysis of patent data for flame-retardant plastics additives

Abstract

Plastics are commercially produced by selecting a polymer resin and incorporating chemical additives to affect specific mechanical, chemical or aesthetic properties of the plastic products. The number of possible combinations of polymers and additives yields an enormous engineering space to meet the design requirements of the many applications of plastic materials. However, the broad scope of plastics science hinders both the invention of new plastics formulations and efforts to investigate potentially harmful polymer resins and plastic additives. In this thesis, a method of representing and analyzing the claims section of patents is presented and applied to a set of patents that refer to flame retardants. The claims section of a patent is presented as a graph, with individual claims as points and references between claims as lines connecting those points.

The chemical terms mentioned in the text of each of the claims were split into individual words or short sequences of words, called "tokens", by an existing materials tokenizer that had been trained on scientific journal articles. The term frequency - inverse document frequency (tf-idf) statistic for each token within each claim was computed, using the entire claims section of the individual patent to calculate the document frequency. Each claim was attributed the tokens that had tf-idf scores greater than the highest-scoring term shared with a claim to which that claim referred. By researcher inspection, this method served to extract relevant chemical terms, while omitting words that did not contribute to the chemical relevance of the claim or patent as a whole. A visualization of these labelled graphs of the claims was generated.

This reduced, graphical representation of materials patents could be implemented to aid in researcher review or computational tasks to survey for chemical components or resin-additive compatibilities. Such a representation of patent data could make the prioritization and review of commercial chemicals a more tractable task.