Abstract: A method for preparing high-purity bisphenol A which comprises a principal process comprising a first reaction step for reacting phenol with acetone, a first concentration adjusting step, a first crystallization step for precipitating crystals of the adduct of bisphenol A with phenol, a first separation step for separating a solution containing the crystals of the adduct into the crystals and the mother liquor and a phenol removing step for removing phenol from the crystals of the adduct; and a sub-process comprising a second reaction step for reacting p-isopropenylphenol with phenol, a second concentration adjusting step, a second crystallization step, a second separation step for separating a solution containing the second any crystals of the adduct into the second any crystals and the second mother liquor and a cleaving step, the first mother liquor from the principal process being fed to the sub-process and the second any crystals of the adduct from the sub-process being fed to the principal process, is h

Abstract: A process for producing high-purity bisphenol A comprises reacting phenol with acetone in the presence of an acid catalyst to obtain a product mixture, removing the acid catalyst from the product mixture, thereby yielding a liquid mixture, treating the liquid mixture with a weakly basic ion-exchange resin having pyridyl groups as the exchange groups, and purifying the treated liquid mixture. The process does not cause any corrosion of equipment and any decomposition and discoloration of bisphenol A during distillation.

Abstract: A process for producing high-purity bisphenol A comprises reacting phenol with acetone in the presence of hydrochloric acid as the catalyst to obtain a product mixture, removing the hydrochloric acid from the product mixture, thereby yielding a liquid mixture, adding water to the liquid mixture, evaporating a water-phenol mixture from the liquid mixture under reduced pressure, thereby cooling the liquid mixture and crystallizing out the adduct of bisphenol A with phenol, and finally recovering bisphenol A from the adduct, wherein an improvement comprises treating the water-phenol mixture with a weakly basic ion-exchange resin and recycling and reusing the treated mixture as the water to be added to the liquid mixture. This process does not causes any troubles such as the corrosion of equipment and the decomposition and discoloration of bisphenol A during distillation.

Abstract: A process for crystallizing the adduct of bisphenol A with phenol from a phenol solution in the presence of water comprises controlling the concentration of bisphenol A in said solution by removing portion of the phenol from said solution or adding phenol to said solution according to feedback control based on the measurement of solution density to obtain an adjusted solution, and feeding the adjusted solution to the crystallizer in which its inside wall is kept at a temperature higher than that of the adjusted solution, provided the temperature difference being smaller than 5.degree. C. The crystallized adduct has a uniform particle size and a high purity.

Abstract: A process for washing and obtaining solids of a slurry comprises feeding a slurry containing the adduct of bisphenol A with phenol crystallized from a phenol solution of bisphenol A to a first solid-liquid separator to separate solids from the slurry, transferring the solids separated by the first solid-liquid separator to an agitation tank in which the solids are reslurried, feeding the slurry obtained in the agitation tank to a second solid-liquid separator, said second solid-liquid separator being intended to obtain the solids from the slurry discharged from the agitation tank, and permitting the admission of a washing solvent to wash the solids, and permitting the filtrate and washings to be recovered independently, feeding the washing solvent to the second solid-liquid separator, feeding all of the washings from the second solid-liquid separator to the agitation tank, feeding a part of the filtrate from the second solid-liquid separator to the agitation tank, and discharging the remainder of the filtrate

Abstract: In a process for producing bisphenol A by reacting phenol and acetone in the presence of hydrochloric acid as a catalyst, the improvement comprising adding the water-containing phenol separated from the reaction product mixture in the purification stage to the reaction mixture containing phenol and acetone, in such an amount that the water content in the reaction mixture is within the range of 1 to 5 wt%, said water-containing phenol being obtained from the dehydrochlorination step of the reaction product mixture, condensing the distilled off gases and liquid-separating of the condensates.

Abstract: The process for preparing 2,2-bis(4-hydroxyphenyl)propane (bisphenol A) by reacting acetone with phenol and decomposing the resultant adduct of bisphenol A and phenol is well known. However, the quality of bisphenol A thus obtained is not always satisfactory.In the process of this invention, the adduct is washed with phenol recovered by decomposing an adduct of bisphenol A and phenol, and then bisphenol A is prepared by decomposing the washed adduct.The bisphenol A prepared by the process of this invention has an extremely high quality and is suitable for the preparation of polycarbonate used for optical parts.

Abstract: A process for preparing high purity bisphenol A comprising feeding continuously phenol and acetone in the presence of a hydrochloric acid catalyst into a first stage reactor and reacting phenol and acetone in the range of 20-60 mol % of acetone conversion and continuously removing the first reaction product from the first stage reactor. The first reaction product is fed into a second stage reactor and the reaction of phenol and acetone is completed to obtain a second reaction product from which bisphenol A is recovered.

Abstract: A process for obtaining high-purity bisphenol A by removing most part of phenol from an adduct of bisphenol A with phenol and removing continously the residual phenol by steam stripping, wherein a multi-tubular packed column is used as a stripping equipment. The residual phenol in bisphenol A can be removed constantly. In addition, the process of the present invention is economical because the residual phenol can be removed with a small amount of steam.

Abstract: This invention is a process for the preparation of bisphenol A from acetone and phenol. By this invention, the formation of by-products is extremely decreased and post treatment steps can be simplified.This invention involves the following steps. (1) One mole of acetone is reacted with 4 to 12 moles of phenol in the presence of a sulfonic acid type cation exchange resin catalyst modified with a mercapto group-containing compound such as mercaptoethylamine to convert 20 to 60% of acetone, and (2) the reaction mixture containing unreacted acetone is successively reacted to the presence of the hydrochloric acid catalyst.The formation of by-products such as 2-(2-hydroxyphenyl)-2-(4-hydroxyphenyl)propane, Dianin's compound and the like is remarkably reduced by the process of this invention.

Abstract: A recorder has a beam generator for generating a beam to form a dot image on a record medium. The beam generator has first and second beam generation sources to generate first and second beams and forms each dot by using both of the first and second beams.

Abstract: This invention relates to a process for preparing 2,2-bis(4-hydroxyphenyl)propane, e.g. bisphenol A and particularly to a process for preparing high quality bisphenol A with good workability by distilling the intermediate adduct of bisphenol A and phenol.The adduct of bisphenol A and phenol is fed to a distillation column. Phenol is recovered from the top of the column and bisphenol A is obtained from its bottom. In this distillation process, the adduct of bisphenol A and phenol is added with a part of recycled bottom liquid. Consequently troubles such as plugging of the distillation column are prevented, continuous operation becomes possible for a long period of time and high quality bisphenol A can be steadily obtained.

Abstract: An electroconductive article is disclosed, which comprises a polar group-containing high polymeric substrate, and an electroconductive layer of cupric sulfide formed therein and is produced by immersing the polar group-containing high polymeric substrate in an aqueous solution containing a bivalent copper compound and a reducing agent or an aqueous solution containing a monovalent copper compound, and at the same time or subsequently treating it in a solution of a sulfur releasable substance.

Abstract: A sealant composition for the puncture-sealing tire and a method of producing the same are disclosed. This sealant composition is crosslinking-reaction type and comprises (A) at least one rubber, (B) a tackifier, (C) an acryloyl or methacryloyl group-containing polymerizable unsaturated compound, (D) a filler and (E) a photopolymerization initiator. In the production of the sealant composition, the component (A) is first reacted with the component (C) and then kneaded with the components (B), (D) and (E).

Abstract: This specification discloses a both-side recording apparatus in which a sheet conveyed by first recording means for recording an image on a first surface of the sheet is reversed by sheet reversing means and directed to second recording means for recording an image on a second surface of the sheet, whereby images are recorded on the first and second surfaces of the sheet.

Abstract: A sealant composition for the puncture-sealing tire and a method of producing the same are disclosed. This sealant composition is crosslinking-reaction type and comprises (A) at least one rubber, (B) a tackifier, (C) an acryloyl or methacryloyl group-containing polymerizable unsaturated compound, (D) a filler and (E) a photopolymerization initiator. In the production of the sealant composition, the component (A) is first reacted with the component (C) and then kneaded with the components (B), (D) and (E).

Abstract: A semiconductor laser device has a high switching speed and low cost, and comprises a common electrode, on the surface of a P-type semiconductor wafer forming plural light sources. The semiconductor laser device is further featured by having grooves provided on said semiconductor wafer to allow independent drive of said light sources and to reduce the distance between the light-emitting points of the light sources.

Abstract: An information output device constructed with a storing device which stores therein information code signals and instruction signals, a first pattern generator which generates a pattern in the first density, a second pattern generator which generates a pattern in the second density, a reader which reads out the information code signal and instruction signal from the storing device, a device to apply the information code signal to the first pattern generator and sequentially read out the same with the first frequency, when the instruction signal read out of the reading device instructs the first density, and to apply the information code signal to the second pattern generator and sequentially read out the same with the second frequecy different from the first frequency, when the instructions signal instructs the second density, and an output device which produces an output pattern read out of the applying and reading device in the form of visible information.

Abstract: A collator has a common light-emitting element for emitting light to a photosensitive element for detecting an empty bin and to a photosensitive element for detecting a full bin; or a common photosensitive element for receiving light emitted from a light-emitting element for detection of an empty bin and from a light-emitting element for detection of a full bin. The collator allows correct detection of an empty bin and a full bin with fewer members and with simple construction. After detection of a full bin, some sheets already printed by a high-speed printer or the like can still be stacked in a space above the full bin level. Each bin also incorporates a bin inlet sensor to prevent erratic detection of a full bin or an empty bin when a sheet is in the process of being inserted in the bin through the inlet.

Abstract: Electrostatic recording apparatus forming small non-recording regions in a recording field includes a beam generator generating a beam modulated with a modulation signal, an irradiating unit directing the beam to a photosensitive member to form an electrostatic image, a determination circuit determining when the electrostatic image formed by the beam on the photosensitive member exceeds a predetermined size, an interruptor for intermittently interrupting the emission of the beam at small time intervals, and an actuating circuit actuating the interruptor when the determination circuit determines when the electrostatic image exceeds the size.