A carboxylic acid onium salt of formula (1) exerts a satisfactory acid diffusion control (or quencher) function. A resist composition comprising the carboxylic acid onium salt can be processed by DUV or EUV lithography to form a resist pattern with improved resolution, reduced LWR and minimal defects after development. ##STR00001##

A resist composition comprising a base resin comprising acid labile group-containing recurring units and preferably acid generator-containing recurring units, and a sodium, magnesium, potassium, calcium, rubidium, strontium, yttrium, cesium, barium or cerium salt of -fluorinated sulfonic acid bonded to an alkyl, alkenyl, alkynyl or aryl group exhibits a high resolution and sensitivity and forms a pattern of satisfactory profile with minimal LWR after exposure and development.

A process for extracting isoprene from a pyrolysis gas mixture or a C5 fraction wherein isoprene is purified by plural extractive distillations in the presence of a polar solvent and cyclopentadiene is effectively removed and recycled as a feedstock without being converted into its dimer, dicyclopentadiene. The isoprene recovered from the process described is more than 99.5% pure.

Apparatuses, systems and methods for producing Pips stream for manufacturing catalytic C5 hydrocarbon resins containing all the key reactive monomers that are already present in the C5 fraction of the pyrolysis gasoline, which is otherwise lost with the crude isoprene stream, are disclosed herein. Embodiments of the invention are directed to producing a hydrocarbon resin grade DCPD stream consisting of dimers and codimers of isoprene which are of value in manufacturing thermal hydrocarbon resins, either polymer grade isoprene and gasoline quality raffinate (free or sulfur and acetylenes) or a relatively small crude isoprene stream with maximum utilization of isoprene by moving some of the isoprene to a DCPD stream used to manufacture thermal hydrocarbon resins.

A sulfonium salt containing an acid-eliminatable substituent group which is effective for improving contrast is highly soluble and uniformly dispersible. A resist composition comprising the sulfonium salt as photoacid generator forms a pattern with a high resolution, rectangularity, and reduced LWR.

The purpose of the present invention is to provide a novel ester compound which can be used as a component of a cosmetic component. An ester compound of tricyclo[5.2.1.0.sup.2,6]decane, which is represented by formula (I).

Thermosetting resin compositions are provided that are useful for mounting onto a circuit board semiconductor devices, such as chip size or chip scale packages (CSPs), ball grid arrays (BGAs), land grid arrays (LGAs) and the like (collectively, subcomponents), or semiconductor chips. Reaction products of the compositions are controllably reworkable when subjected to appropriate conditions.

Processes and systems for making cyclopentadiene and/or dicyclopentadiene include converting acyclic C5 hydrocarbon(s) into CPD in a first reactor to obtain a product mixture, separating the product mixture in a separation sub-system such as compression train to obtain a C5-rich fraction comprising CPD and essentially depleted of hydrogen and C1-C4 hydrocarbons, dimerizing the C5-rich fraction in a dimerization reactor to obtain a product effluent comprising DCPD, followed by separating the product effluent to obtain a DCPD-rich fraction. Multiple-stage of dimerization and separation steps can be optionally used to obtain multiple DCPD-rich fractions of various degrees of purity and quantity. C5-rich fractions from various stages of the process may be recycled to the first reactor, or converted into mogas components after selective hydrogenation. C5-rich fractions and mogas components may be optionally separated to produce value-adding chemicals.

A compound is represented by a formula (1) below. In the formula (1), n is 1 or 2. Ar.sup.1 is represented by a formula (2) below. Ar.sup.2 represents a substituted or unsubstituted aromatic hydrocarbon group having 6 to 30 carbon atoms, or a substituted or unsubstituted heterocyclic group having 1 to 20 ring atoms. Ar.sup.3 is represented by a formula (3) below. ##STR00001##

A method to generate cyclic hydrocarbons from farnesene to increase both the density and net heat of combustion of the product fuels.