Gerd Leston — 19 Patents at Koppers

Gerd Leston has been granted 19 US patents while listed as an inventor at Koppers. The first was granted in 1981 and the most recent in February 1985. Gerd Leston ranks #229,345 of 4,157,543 US inventors in our database (top 5.5%). Patent records list Gerd Leston in Pittsburgh, PA, US.

Issued Patents All Time

Showing 1–19 of 19 patents

Patent #	Title	Co-Inventors	Date	Approx Value ⓘ
4499312	Complex formed to separate 3,5-xylenol or 3,4-xylenol from other polymethylated phenolic compounds	—	1985-02-12	$4,153,000
4496774	Complex formed to separate nitrated phenolic compounds from other phenolic compounds	—	1985-01-29	$2,128,000
4480140	Process for alkylating phenolic compounds to produce ortho or para-monoalkylated or 2,4- or 2,6-dialkylated phenols	—	1984-10-30	$4,416,000
4479019	Complex formed to separate nitrated phenolic compounds from other phenolic compounds	—	1984-10-23	$2,165,000
4475001	Process for alkylating phenolic compounds to produce ortho- or para-monoalkylated phenols or 2,4- or 2,6-dialkylated phenols	—	1984-10-02	$4,890,000
4469901	Complex formed for separating isopropylated m-cresols	—	1984-09-04	$2,430,000
4469900	Complex formed for separating chlorinated phenols	—	1984-09-04	$2,430,000
4447658	Process for separating 3,5-xylenol or 3,4-xylenol from other polymethylated phenolic compounds	—	1984-05-08	$1,127,000
4447654	Process for separating nitrated phenolic compounds from other phenolic compounds	—	1984-05-08	$1,127,000
4431846	Reduction of o-ethylphenol in m,p-cresol by preferential t-butylation	—	1984-02-14	$1,226,000
4429169	Process for separating isopropylated m-cresols	—	1984-01-31	$1,470,000
4429168	Process for separating chlorinated phenols	—	1984-01-31	$1,470,000
4424381	Process for separating dihydric phenols	—	1984-01-03	$2,092,000
4423253	Process for separating t-butylated phenols	—	1983-12-27	$2,112,000
4394526	Para-cresol halide salt complex useful for separating para-cresol from meta-cresol	—	1983-07-19	$4,569,000
4267389	Process for separating para-cresol from a mixture of methylated and ethylated phenols	—	1981-05-12	$1,091,000
4267390	Process for obtaining para-cresol and meta-cresol from a mixture of methylated and ethylated phenols characterized by selective complexation with calcium bromide and sodium acetate	—	1981-05-12	$1,091,000
4267391	Process for obtaining para-cresol and meta-cresol from a mixture of methylated and ethylated phenols characterized by urea clathration of metal-cresol	—	1981-05-12	$1,091,000
4267392	Process for obtaining para-cresol and meta-cresol from a mixture of methylated and ethylated phenols containing meta-para-cresol	—	1981-05-12	$1,091,000

Gerd Leston — 19 Patents

Issued Patents All Time

Patent Widget