Abstract: An object of the invention is to provide a process for producing an ether (co)polymer in which molecular weight control is easy and post treatment of the reaction liquid after polymerization (solvent recovery, etc.) is easy; a chain transfer agent to be used in the production process; and an ether (co) polymer obtained according to the production process. The process for producing an ether (co) polymer of the invention is characterized in that an ether monomer is polymerized in a solvent, in the presence of a catalyst comprising a condensate of an organotin compound and an alkyl phosphate, and a chain transfer agent comprising, as the major ingredient thereof, an aliphatic polyalcohol of the following general formula (I), thereby producing an ether (co)polymer. Cx(OH)yHz. In the formula, X indicates an integer of from 2 to 8; Y indicates an integer of from 2 to (2X+2); Z indicates an integer of 2X+2?Y; and the hydroxyl groups are bonded at any positions.

Abstract: The invention provides a hydrofluoric acid wastewater treatment method that achieves efficient recovery of hydrofluoric acid from hydrofluoric acid wastewater and also achieves sufficient reduction in the hydrofluoric acid concentration of the dehydrofluorinated water after treatment.

Abstract: The invention provides a hydrofluoric acid wastewater treatment method that achieves efficient recovery of hydrofluoric acid from hydrofluoric acid wastewater and also achieves sufficient reduction in the hydrofluoric acid concentration of the dehydrofluorinated water after treatment.

Abstract: A improved process for preparing 4-hydroxy-2-pyrrolidone of the formula ##STR1## which is characterized in reacting a 4-halogeno-3-hydroxybutyrate and an alkali metal or alkaline earth metal azide, to produce a 4-azido-3-hydroxybutyrate and hydrogenating an azide group of the ester compound and then cyclizing a hydrogenated compound. 4-Hydroxy-2-pyrrolidone is useful for an intermediate of medicines and agricultural chemicals.

Abstract: A molding resin composition containing, in a resin, a filler comprising a globular powder of which mean particle diameter is not smaller than 0.1 .mu.m and not greater than 1.5 .mu.m (x component), a globular powder of which mean particle diameter is not smaller than 2 .mu.m and not greater than 15 .mu.m (y component) and a globular powder of which mean particle diameter is not smaller than 20 .mu.m and not greater than 70 .mu.m (z component), wherein proportions of the x, y and z components based on the total volume of x, y and z components are not smaller than 10% by volume and not greater than 24% by volume, not smaller than 0.1% by volume and not greater than 36% by volume and not smaller than 57% by volume and not greater than 76% by volume, exhibits an excellent fluidity even when loaded with a high percentage of filler. Further, their cured products are lowered in the moisture absorption and thermal expansion coefficient of which increases result from the resin itself present in the cured product.

Abstract: An unsaturated imide compound represented by formula (1): ##STR1## wherein Q is an alicyclic structure-containing hydrocarbon group having 4-20 carbon atoms; each of R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.i and R.sub.j represents a hydrogen atom, a halogen atom, a hydrocarbon group having 1-6 carbon atoms or a halogen-containing hydrocarbon group having 1-6 carbon atoms; each of a, b, c, d, e and f represents an integer of 0 to 4 satisfying a+b.ltoreq.4, c+d.ltoreq.4 and e+f.ltoreq.4 and D represents a divalent organic group having 2-24 carbon atoms and an ethylenically unsaturated double bond, a process for producing the unsaturated imide compound of formula (1) and intermediates for producing the unsaturated imide compound of formula (1). The unsaturated imide compound of formula (1) is well soluble in organic solvents and can give cured products excellent in heat resistance, low water absorption and flexibility.

Abstract: A molding resin composition containing, in a resin, a filler comprising a globular powder of which mean particle diameter is not smaller than 0.1 .mu.m and not greater than 1.5 .mu.m (x component), a globular powder of which mean particle diameter is not smaller than 2 .mu.m and not greater than 15 .mu.m (y component) and a globular powder of which mean particle diameter is not smaller than 20 .mu.m and not greater than 70 .mu.m (z component), wherein proportions of the x, y and z components based on the total volume of x, y and z components are not smaller than 10% by volume and not greater than 24% by volume, not smaller than 0.1% by volume and not greater than 36% by volume and not smaller than 57% by volume and not greater than 76% by volume, exhibits an excellent fluidity even when loaded with a high percentage of filler. Further, their cured products are lowered in the moisture absorption and thermal expansion coefficient of which increases result from the resin itself present in the cured product.

Abstract: An epoxy resin composition comprising (A) an epoxy resin represented by the general formula (1) ##STR1## wherein each R.sub.1, independent of the other, represents hydrogen, a hologen atom, an alkyl group having 1 to 6 carbon atoms, substituted- or nonsubstituted-phenyl groups, and X represents ##STR2## and n represents an integer of 0 to 4, and (B) a curing agent, which composition provides a cured product exhibiting low hygroscopicity and high adhesiveness.

Abstract: An epoxy resin composition which comprises: (a) an epoxy resin having at least two epoxy groups in the molecule, (b) an epoxy resin curing agent, (c) a cure accelerator, (d) an aromatic polyamide pulp and (e) an inorganic filler as the essential components, the aromatic polyamide pulp (d) being contained in an amount of 0.5 to 10% by weight based on the total weight of the component (a), the component (b) and the component (d), and the inorganic filler (e) being contained in an amount of 75 to 94% by weight based on the total weight of the component (a), the component (b), the component (c) and the component (e), and a semiconductor device sealed with the above epoxy resin composition. The cured product of the epoxy resin composition is good in balance of hot impact strength and hot flexural strength and hence, the semiconductor device sealed with the epoxy resin composition is excellent in soldering resistance.

Abstract: The present invention provides a method of measuring particles and an apparatus for the same, which count only particles in liquid by distinguishing between the particles and bubbles in liquid. In order to fulfill the above requirements, in the present invention, liquid to be measured flows through a flow cell at a fixed flow rate, and a laser beam is irradiated thereto. Scattering light is generated when particles and bubbles pass through a laser beam irradiation region, and the scattering light is converted into a pulse signal by a photoelectric converter. In the pulse signals, a pulse signal having a pulse width of 100 .mu.S is regarded as corresponding to light scattered by a bubble, which is omitted from the number of pulse signals. Thus, only a pulse signal corresponding to light scattered by a particle in liquid can be measured.

Abstract: A process for encapsulating a semiconductor device involves the step(s) of encapsulating the device with an epoxy resin composites represented by the formula (2) ##STR1## in which R.sub.1 to R.sub.4 independently represent hydrogen, an alkyl or cycloalkyl group having 1 to 9 carbon atoms, or halogen, and X represents hydrogen, an alkyl group having 1 to 9 carbon atoms, or an aryl and n represents an average number of repeating units of 0.1 to 1.6; and a curing agent.

Abstract: A pipe clogging detecting device which incessantly monitors states of a pipe through which fluid is flowing, and when clogging occurs, immediately alarms the occurrence of clogging to operators. The device includes a plurality of containers, a pipe interconnecting the containers, a vibration sensor provided on the pipe, and a detecting device for detecting the occurrence of clogging in the pipe, based on output signals from the vibration sensor.

Abstract: A ferroelectric liquid crystal device having a pair of substrates each provided with voltage applying means, an orientation control layer formed on at least one of the substrates, and a layer of ferroelectric liquid crystal composition disposed between the pair of substrates, the ferroelectric liquid crystal composition comprising at least one compound (a) having an optically active group of the formula (I): ##STR1## at least one compound (b) which is reverse to the compound (a) in the direction of a helical pitch induced in a nematic phase and at least one liquid crystal compound (c) exhibiting a smectic C phase, the liquid crystal composition exhibiting at least a smectic C phase, smectic A phase and nematic phase.

Abstract: An unsaturated imide compound represented by formula (1): ##STR1## wherein Q is an alicyclic structure-containing hydrocarbon group having 4-20 carbon atoms; each of R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.i and R.sub.j represents a hydrogen atom, a halogen atom, a hydrocarbon group having 1-6 carbon atoms or a halogen-containing hydrocarbon group having 1-6 carbon atoms; each of a, b, c, d, e and f represents an integer of 0 to 4 satisfying a+b.ltoreq.4, c+d.ltoreq.4 and e+f.ltoreq.4 and D represents a divalent organic group having 2-24 carbon atoms and an ethylenically unsaturated double bond, a process for producing the unsaturated imide compound of formula (1) and intermediates for producing the unsaturated imide compound of formula (1). The unsaturated imide compound of formula (1) is well soluble in organic solvents and can give cured products excellent in heat resistance, low water absorption and flexibility.

Abstract: The present invention provides polyhydric phenols which are starting materials for glycidyl ether compounds which can provide cured products having low moisture absorption, high heat resistance and improved crack resistance and can be used for encapsulating semiconductor devices. The polyhydric phenols are represented by the following formula: ##STR1## wherein R.sup.1 independently represents a halogen atom, an alkyl or cycloalkyl group of 1-9 carbon atoms, an alkoxy group of 4 or less carbon atoms or an aryl group and R.sup.1 may be identical or different when l is 2 or more, R.sup.2 independently represents a halogen atom, an alkoxy group of 4 or less carbon atoms or an alkyl group of 6 or less carbon atoms and R.sup.2 may be identical or different when m is 2 or more, R.sup.

Abstract: An epoxy resin composition contains (a) an epoxy resin represented by the general formula (2) ##STR1## wherein R.sub.1 to R.sub.4 independently represent hydrogen, an alkyl or cycloalkyl group having 1 to 9 carbon atoms, or halogen, and X represents hydrogen, an alkyl group having 1 to 9 carbon atoms, or an aryl and n represents an average number of repeating units of 0.1 to 1.6; and a curing agent.

Abstract: An unsaturated imide compound represented by formula (1): ##STR1## wherein Q is an alicyclic structure-containing hydrocarbon group having 4-20 carbon atoms; each of R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.i and R.sub.j represents a hydrogen atom, a halogen atom, a hydrocarbon group having 1-6 carbon atoms or a halogen-containing hydrocarbon group having 1-6 carbon atoms; each of a, b, c, d, e and f represents an integer of 0 to 4 satisfying a+b.ltoreq.4, c+d.ltoreq.4 and e+f.ltoreq.4 and D represents a divalent organic group having 2-24 carbon atoms and an ethylenically unsaturated double bond, a process for producing the unsaturated imide compound of formula (1) and intermediates for producing the unsaturated imide compound of formula (1). The unsaturated imide compound of formula (1) is well soluble in organic solvents and can give cured products excellent in heat resistance, low water absorption and flexibility.

Abstract: There is provided an epoxy resin composition represented by the general formula: ##STR1## wherein R.sub.1 represents an alkyl or cycloalkyl group having 1 to 9 carbon atoms, or halogen, R.sub.2 to R.sub.4 independently represent hydrogen, an alkyl or cycloalkyl group having 1 to 9 carbon atoms, or halogen, and X represents hydrogen, an alkyl group having 1 to 9 carbon atoms, or an aryl group, and n represents an average number of repeating units of 0.1 to 1.6. Cured products prepared from the epoxy resin have a lower hygroscopicity and a balance between thermal resistance and curing performance.

Abstract: A ferroelectric liquid crystal device having a pair of substrates each provided with voltage application means, an orientation control layer formed on at least one of the substrates, and a layer of ferroelectric liquid crystal composition formed between the pair of substrates, the device being characterized in that the ferroelectric liquid crystal composition comprises at least one compound (a) having an optically active group of the formula (I): ##STR1## and at least one compound (b) which is reverse to the compound (a) in the direction of a helical pitch induced in a nematic phase, the liquid crystal composition exhibiting at least a smectic C phase, smectic A phase and nematic phase at least 20 .mu.m in helical pitch.

Abstract: An unsaturated imide compound represented by formula (1): ##STR1## wherein Q is an alicyclic structure-containing hydrocarbon group having 4-20 carbon atoms; each of R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.i and R.sub.j represents a hydrogen atom, a halogen atom, a hydrocarbon group having 1-6 carbon atoms or a halogen-containing hydrocarbon group having 1-6 carbon atoms; each of a, b, c, d, e and f represents an integer of 0 to 4 satisfying a+b.ltoreq.4, c+d.ltoreq.4 and e+f.ltoreq.4 and D represents a divalent organic group having 2-24 carbon atoms and an ethylenically unsaturated double bond, a process for producing the unsaturated imide compound of formula (1) and intermediates for producing the unsaturated imide compound of formula (1). The unsaturated imide compound of formula (1) is well soluble in organic solvents and can give cured products excellent in heat resistance, low water absorption and flexibility.