# US 4,394,307 A · Track recording plastic compositions > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 4,394,307 A - Document ID: US4394307A - Status: Granted - Kind: A - Application number: 06/235,691 - Filed: 1981-02-18 - Granted: 1983-07-19 - Earliest claimed: 1981-02-18 - Inventors: Gregory Tarle - Web page: https://patentgrep.com/patent/US4394307A ## CPC - G01T 5/10: Plates or blocks in which tracks of nuclear particles are made visible by after-treatment, e.g. using photographic emulsion, using mica - G03F 7/039: Macromolecular compounds which are photodegradable, e.g. positive electron resists (G03F7/075 takes precedence; macromolecular quinonediazides G03F7/023) - G01T: MEASUREMENT OF NUCLEAR OR X-RADIATION (radiation analysis of materials, mass spectrometry G01N23/00; tubes for determining the presence, intensity, density or energy of radiation or particles H01J47/00) - G03F: PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR; (phototypographic composing devices B41B; photosensitive materials or processes for photographic purposes G03C; electrophotography, sensitive layers or processes therefor G03G) ## Abstract Improved nuclear track recording plastic compositions are provided which exhibit greatly decreased surface roughness when etched to produce visible tracks of energetic nuclear particles which have passed into and/or through said plastic. The improved compositions incorporate a small quantity of a phthalic acid ester into the major plastic component which is derived from the polymerization of monomeric di-ethylene glycol bis allyl carbonate. Di-substituted phthalic acid esters are preferred as the added component, with the further perference that the ester substituent has a chain length of 2 or more carbon atoms. The inclusion of the phthalic acid ester to an extent of from about 1-2% by weight of the plastic compositions is sufficient to drastically reduce the surface roughness ordinarily produced when the track recording plastic is contacted by etchants. ## Claims ### Claim 1 An improved nuclear particle track recording solid plastic composition consisting essentially of about 98% by weight of polymeric di-ethylene glycol bis allyl carbonate and an effective amount to reduce roughening caused by etchants up to about 2% by weight of a alkyl phthalic acid ester admixed therein. ### Claim 2 (depends on 1) The improved recording plastic composition of claim 1 wherein said phthalic acid ester is a di-substituted ester. ### Claim 3 (depends on 1) The improved track recording plastic of claim 1 wherein the phthalic acid ester is a mono-substituted ester, or mixtures of di-substituted and mono-substituted esters. ### Claim 4 (depends on 1) The improved track recording plastic of claim 1 wherein the alcohol derived substituent on the phthalic acid ester includes at least two or more carbon atoms in the ester substituent chain. ### Claim 5 (depends on 1) The improved track recording plastic composition of claim 1 wherein the di-substituted phthalic acid ester is di-octyl phthalate. ### Claim 6 In a track recording solid plastic composition consisting essentially of polymerized diethylene glycol bis allyl carbonate, the improvement comprising including in said composition an effective amount to reduce roughening caused by etchants up to about 2% by weight of a alkyl phthalic acid ester in the di-ethylene glcyol bis allyl carbonate. ### Claim 7 (depends on 6) The improvement of claim 6 wherein the phthalic acid ester is a di-substituted ester. ### Claim 8 (depends on 6) The improvement of claim 6 wherein the phthalic acid ester is a mono-substituted ester, or a mixture of a mono-substituted and a di-substituted ester. ### Claim 9 (depends on 6) The improvement of claim 6 wherein the ester substituents on the phthalic acid include at least two or more carbon atoms. ### Claim 10 (depends on 7) The improvement of claim 7 wherein the di-substituted phthalic acid ester is dioctyl phthalate. ### Claim 11 A method for producing an improved nuclear particle track recording plastic composition comprising admixing together about 98% by weight of monomeric di-ethylene glycol bis allyl carbonate, a small amount of a polymerization promotor for the di-ethylene glycol bis allyl carbonate, and an effective amount to reduce roughening caused by etchants up to about 2% by weight of a alkyl phthalic acid ester; and then heating the composition to polymerize the di-ethylene glycol bis allyl carbonate into a solid transparent polymer with the phthalic acid ester incorporated therein. ### Claim 12 (depends on 11) The method of claim 11 wherein the ester substituent portion of the phthalic acid ester consists of at least two or more carbon atoms. ### Claim 13 (depends on 11) The method of claim 11 wherein the phthalic acid ester is dioctyl phthalate. ### Claim 14 A method for producing an improved nuclear particle track recording CR-39 plastic composition comprising adding to said CR-39 when in the monomeric state, an anti-roughening agent in an amount of up to about 2% by weight of the composition, thereafter polymerizing the CR-39 to produce a polymeric CR-39 plastic solid composition including the anti-roughening agent therein. ### Claim 15 (depends on 14) The method of claim 14 wherein the anti-roughening agent is a phthalic acid ester wherein the ester substituent portion consists of at least 2 or more carbon atoms.