baber/WOPTO huggingface dataset:
Patent SG-11201907974T-A (SG)
Title: Non-pickled hot-rolled steel sheet and method for manufacturing same
Inventor: KIZU TARO
IPC: B21B45/00
Filed: 2018-03-28
Abstract: NON-PICKLED HOT-ROLLED STEEL SHEET AND METHOD FOR MANUFACTURING SAME 5 Provided is a non-pickled hot-rolled steel sheet demonstrating sufficient blackness seen from any direction and excellent scale adhesion. The non-pickled hot-rolled steel sheet comprises a base hot-rolled steel sheet and scale on a surface of the base hot-rolled steel sheet, the scale consisting of Fe 3O4 and Fe and having a thickness of 3.0-20 µm, wherein an average grain 10 size on a surface layer of the scale comprises 3.0 µm or less, an area ratio of Fe in a cross-section of the scale comprises less than 1.0 % in a region of 0-1.0 µm in a thickness direction of the scale from an outermost surface layer of the scale, while 1.0 % or more in a region of 0-1.0 µm in the thickness direction of the scale from an interface between the scale and the base 15 hot-rolled steel sheet. (FIG. 2)
Patent HU-188207-B (HU)
Inventor: RUOHONEN JARKKO
IPC: C07C233/12
Filed: 1980-01-09
Abstract: Neue alpha-Acyloxy-acetamide der allgemeinen Formel (I), in der R&ind1! ein Chlor- oder Bromatom; R&ind2! die Trifluormethylgruppe, ein Fluor- oder Chloratom; R&ind3! einen verzweigten Alkylrest oder eine Cycloalkylgruppe mit jeweils 3 bis 5 Kohlenstoffatomen u. R&ind4! einen Acylrest einer Carbonsaeure bedeuten. Diese neuen Zwischenprodukte lassen sich zu den entsprechenden Phenyl-aethanolaminen reduzieren, welche wertvolle pharmakologische Eigenschaften aufweisen, insbesondere broncholytische Wirkungen. Die neuen Zwischenprodukte erhaelt man durch Umsetzung eines entsprechenden Benzaldehyds mit einem entsprechenden Isonitril und einer entsprechenden Carbonsaeure.
Patent HU-203910-B (HU)
Inventor: MOLNAR ATTILA
IPC: E04C3/02
Filed: 1988-01-07
Abstract: Síkbeli rácsos tartószerkezet, elsősorban magasépítési
csamokszerkezetek keretfőtartói, födém-tartógerendái
és hasonlók számára, amely öveket és az öveket összekötő
rácsrudakat tartalmaz oly módon, hogy az övrúdnak
(1) alsó öve (2), annak függőleges súlyponti tengelyéhez
(5) viszonyított kifelé tartó két gerinclemeze
(3), ezek folytatásaként az alsó övvel (2) párhuzamos
két felső öve (4) van, és az övrúd (1) helyenként
hevederlemezekkel és/vagy pótövekkel és/vagy merevítőlemezekkel
megerősített (1. ábra).
Patent ZA-9136-B (ZA)
Title: 3-aminopiperidine derivatives and related nitrogen containing heterocycles
Inventor: DESAI MANOJ C
IPC: A61K31/395
Filed: 1991-01-03
Abstract: 3-Amino-2-phenylpiperidine is a valuable intermediate for the preparation of certain 3-aminopiperidine substance P antagonists. (Divisional of application no 90313680.2).
Patent HU-208599-B (HU)
Title: Optical signal transmission line of light conductor
Inventor: GRASSO GIORGIO
IPC: H04B10/29
Filed: 1991-01-29
Abstract: The invention refers to an optical fibre transmission line which comprises means (9, 10) for injecting and means (9, 10) for extracting optical service signals from the line' s optical fibre (3), where said means comprise emission and/or reception units (10) of optical service signals, suitable for receiving from the optical line (3) and/or emitting towards the line itself service signals in the form of optical signals having a wavelength which is substantially different from the wavelength of the telecommunications signals, each of which units (10) is associated with a corresponding optical coupler (9) inserted along the line (3), suitable for coupling within the line fibre and/or for extracting from it the optical service signals.
Patent HU-210287-B (HU)
Inventor: FEES HEINER
IPC: B23D77/04
Filed: 1990-08-25
Abstract: A találmány tárgya vágószerszám munkadarabok belső és külső forgásfelületek megmunkálására, legalább egy, a szerszám alaptestén cserélhetően rögzített vágólappal (16), amit egy állítócsavarral (60) a szerszám mértani tengelyére radiálisán be lehet állítani és feszítőelemekkel a szerszám alaptestének (10) a megmunkálási nyomást felvevő támasztóvállán lehet rögzíteni. Evégett a vágólap (16), illetőleg vágószél (18) radiális beállítására szolgáló állítócsavar (60) egyúttal feszítőelemként szolgál, ami a vágólapot (16), illetőleg vágószélt (18) a szerszám alaptestének (10) támasztóvállként működő hosszfalán (30) rögzíti. A találmány szerinti vágószerszám elsődleges alkalmazási területei: finomfúró szerszámok és dörzsszerszámok nagyon kopásálló betét-vágó lapokkal. HU 210 287 B A leírás terjedelme: 6 oldal (ezen belül 2 lap ábra)
Patent HU-204194-B (HU)
Title: Process for producing instant and retard gemfibrosil compositions
Inventor: GHEBRE-SELLASSIE ISAAC
IPC: A61K9/26
Filed: 1990-02-01
Abstract: A disintegratable gemfibrozil tablet providing both immediate and enteric release is compressed from a mixture of a first granulation of gemfibrozil with at least one acid-disintegratable binder and a second granulation formed from the first granulation but regranulated or coated with an alkali-disintegratable formulation of at least one substantially alkali-soluble and substantially acid-insoluble polymer.
Patent RS-49807-B (RS)
Title: 1-PHENYLALKYL-l ,2,3,6- TETRAHYDROPYRlDINES FOR TREATING ALZHEIMER'S DISEASE
Inventor: BARONI MARKO
IPC: A61K31/4418
Filed: 1997-12-12
Abstract: PCT No. PCT/FR97/02286 Sec. 371 Date Jul. 27, 1999 Sec. 102(e) Date Jul. 27, 1999 PCT Filed Dec. 12, 1997 PCT Pub. No. WO98/25903 PCT Pub. Date Jun. 18, 1998The invention relates to compounds of the formula in which: Y is -CH- or -N-; R1 is hydrogen, a halogen or a CF3, (C1-C4)alkyl or (C1-C4)alkoxy group; R2 is a methyl or ethyl group; R3 and R4 are each hydrogen or a (C1-C3)alkyl; and X is: (a) a (C1-C6)alkyl, a (C1-C6)alkoxy, a (C3-C7)carboxyalkyl, a (C1-C4)alkoxy-carbonyl(C1-C6)alkyl, a (C3-C7)carboxyalkoxy or a (C1-C4)alkoxycarbonyl-(C1-C6)alkoxy; (b) a radical selected from (C3-C7)cycloalkyl, (C3-C7)cycloalkoxy, (C3-C7)-cycloalkylmethyl, (C3-C7)cycloalkylamino and cyclohexenyl, it being possible for said radical to be substituted by a halogen, hydroxyl, (C1-C4)-alkoxy, carboxyl, (C1-C4)alkoxycarbonyl, amino or mono- or di-(C1-C4)-alkylamino; or (c) a group selected from a phenyl, phenoxy, phenylamino, N-(C1-C3)alkyl-phenylamino, phenylmethyl, phenylethyl, phenylcarbonyl, phenylthio, phenylsulfonyl, phenylsulfinyl and styryl, it being possible for said group to be monosubstituted or polysubstituted on the phenyl group by a halogen, CF3, (C1-C4)alkyl, (C1-C4)alkoxy, cyano, amino, mono- or di-(C1-C4)alkyl-amino, (C1-C4)acylamino, carboxyl, (C1-C4)alkoxycarbonyl, aminocarbonyl, mono- or di-(C1-C4)alkylaminocarbonyl, amino(C1-C4)alkyl, hydroxy(C1-C4)alkyl or halogeno(C1-C4)alkyl; to a method of preparing them and to the pharmaceutical compositions containing them. These compounds have neurotrophic and neuroprotective activity.
Patent YU-45714-B (YU)
Title: Postupak za dobijanje novih adicionih soli sa kiselinama -2-/2-aminoetil/-tiometil/-5-dimetil aminomftilfurana
Inventor: KASZTREINER E
IPC: C07D/
Filed: 1985-04-30
Abstract: POSTUPAK ZA DOBIJANJE NOVIH ADICIONIH SOLI SA KISELINAMA -2-/2-AMINOETIL/-TIOMETIL/-5-DIMETIL AMINOMFTILFURANA, formule (I) i, prema potrebi, za transformisanje makoje od novih soli u poznatu bazu formule (I), naznačen time, što obuhvata a) reakciju cviterjonskog (5-dimetilaminometil-2-furilmetil) kiselog sulfata formule (II) sa cisteaminom ili sa njegovom adicionom solju sa kiselinom, ili b) tretiranje 5-dimetilaminometil-2-furfurilalkohola formule (IV) sa sumportrioksidom ili sa sredstvom koje je podesno za uvodjenje sumpportrioksida u prisustvu rastvarača, tada odvajanje i reakciju dobivenog (5-dimetilaminometil-2-furilmetil)kiselog sulfata formule (III) sa cisteaminom ili sa njegovom adicionom solju sa kiselinom i, prema potrebi, odvajanje adicione soli sa kiselinom baze formule (I) dobivene postupkom a) ili b) i/ili, prema potrebi, oslobadjanje iz nje baze formule (I), njeno prečišćavanje i/ili transformisanje u drugu adicionu so sa kiselinom baze formule (I).
Patent YU-44100-B (YU)
Title: Process for the enzymatic determination of enzymatic substrates
Inventor: SCHEIBE P
IPC: C12Q1/00
Filed: 1980-04-02
Abstract: The present invention provides a reagent for the enzymatic determination of an enzyme substrate, containing a system for the determination of the substrate, which comprises at least one enzyme, at least one buffer substance and at least one indicator substance and optionally contains adjuvants, wherein the reagent contains a definite amount of the enzyme substrate in an insufficient amount with regard to the substrate determination capacity of the system for the determination of this substrate. The present invention also provides a process for the enzymatic determination of an enzyme substrate in the presence of disturbing substances which can react with the substrate itself or with an intermediate or end product of the indicator reaction, wherein, before the addition of the sample to be investigated, a definite amount of the substrate is first reacted with the reagent until reaction is complete, whereafter the sample to be determined is added.
Patent ZA-94959-B (ZA)
Title: Unit for the detection of residues of antibacterial compounds in liquids
Inventor: RIJN FERDINAND THEODORUS JOZEF VAN
IPC: G01N33/04
Filed: 1994-02-11
Abstract: The detection of residues of antibacterials such as antibiotics and sulpha compounds in liquids such as milk, water, meat juice, serum or urine is disclosed. A test unit comprises an agar medium inoculated with a suitable test organism and two or more redox indicators.
Patent ZA-95526-B (ZA)
Title: Compositions and methods for stimulating platelet production
Inventor: CHOI ESTHER S
IPC: C07K14/71
Filed: 1995-01-23
Abstract: Disclosed is a method for increasing the number of platelets in a mammal, which comprises administering to the mammal a platelet number increasing effective amount of an unbound, preferably a soluble, MPL receptor.
Patent AT-401898-B (AT)
Title: Method and apparatus for producing endless steel belts
IPC: B21D35/00
Filed: 1992-07-10
Granted: 1996-12-27
Abstract: The endless steel belts are used for continuously operating presses. The object on which the invention is based is to impart to the belts a balanced stress condition before their ends are welded together and to achieve high welding strength. The ends of the belt blank 10, which is placed on belt drums 2, 3, are fixed in tensioning devices 13 that can be moved transversely to the axes 4, 5 of the belt drums, and the belt is tensioned to a predetermined prestress. The ends of the belt are then fixed by means of transverse tensioners while maintaining this prestress and, while releasing the prestress, moved to a work spacing and cut to size with shears, and the deformed cut cross sections of the ends 11, 12 of the belt are then cut off, after which the ends are welded together. The endless steel belts are used in continuously operating presses for the production of single- or multi- layer webs of material. <IMAGE>
Patent AT-384709-B (AT)
Title: Watering installation
IPC: A01G25/02
Filed: 1985-06-13
Granted: 1987-12-28
Abstract: The invention relates to a watering installation in the case of which hoses provided with perforations are provided in order to discharge the water to the soil. The hoses are supplied with water from shafts which are provided, in the base region, with a water-supply pipe which is connected to a water source. The water-supply pipe is led upwards in the shaft, the pipe opening being located at a lower level than the level of the water source. <IMAGE>
Patent AT-392257-B (AT)
Title: Installation on crowns of walls of sludge sedimentation tanks or the like in sewage treatment plants
IPC: B01D21/20
Filed: 1987-11-04
Granted: 1991-02-25
Abstract: The installation on crowns of walls of sludge sedimentation tanks or the like in sewage treatment plants serves as runways for rollers of wagons which carry treatment apparatuses and/or working platforms. Along the crown of the wall 12 are placed on its top individual elongate metal plates 1, with their ends abutting, the width of which corresponds at least to the width of the rollers and which are fixed to the crown of the wall 12. They have a corrugated surface. Between the plate 1 and the top of the crown of the wall 12 is provided a plate-shaped interlayer 4 serving for pressure distribution. In the upper side of the plate-shaped interlayer 4 are provided grooves for receiving heating cables 23. The plate-like interlayer 4 is fabricated from a heat- and electrically-insulating material. <IMAGE>
Patent CH-641633-B (CH)
Inventor: SHIN SHIBATA
IPC: G04F5/06
Filed: 1979-10-04
Abstract: The very thin tuning-fork shaped quartz-crystal vibrator (15) is mounted in a casing (30) and comprises two metal rods (31) which are disconnected at two locations of the base of the vibrator which are touched by two conductive films of electrodes for exciting bending in their plane. These electrodes have a particular electrically advantageous configuration allowing such mounting. The two rods pass through the wall of the casing. A certain space remains between the rear side of the tuning fork and the wall of the casing, in which space the two said rods can bend in order to neutralise the stresses which, otherwise, would result from a difference in temperature coefficient between the quartz crystal and the material forming the casing. This component is particularly suited to miniaturisation, its vibrator being used as time base in an electronic watch. <IMAGE>
Patent DK-163543-B (DK)
Inventor: DREXLER JOHANN
IPC: H01H1/20
Filed: 1985-03-28
Abstract: A contact arrangement for switchgear with multiple disconnects by contact points connected in parallel of two contact bridges aligned in a contact actuation link uses a spring collar for a contact pressure spring. The spring collar has cutouts transverse to the spring-action direction into which the contact bridges with the spring collars can be inserted and locked in place transverse to their longitudinal direction. The spring collar is rounded at two facing sliding surfaces in the contact actuation link aligned transverse to the longitudinal direction of the contact bridges. This assures optimal fitting of the contact bridges to the fixed contact components without jamming the spring collar in the alignment.
Patent DK-161873-B (DK)
Inventor: ERDT WOLFGANG
IPC: B23B45/14
Filed: 1985-09-16
Abstract: A drill stand includes a base plate, an elongated guide column extending outwardly from the base plate and a drilling device movably supported on the column. The guide column is formed of two laterally spaced elongated support members each having the same cross-section transversely of the elongated direction. A drilling device is positioned between the two support members. A rack is secured to the guide column and a feed mechanism for moving the drilling device includes a pinion in meshed engagement with the rack. Guide members on the support members fit into correspondingly shaped guide grooves on the drilling device.
Patent FI-67412-B (FI)
Inventor: FRITZVOLD BJOERN H
IPC: D21C9/10
Filed: 1978-04-25
Granted: 1984-11-30
Abstract: In a method for treating cellulose containing pulp, the pulp is fractionated in two or more fractions according to particle size before treating one or more of the fractions with ozone.  The fractionation can be carried out in a fractionating device which is included in a complete treatment process, the fractionating device constituting a series of screens. Depending on the quality of the finished paper product, various ozone treated and untreated fractions of the pulp are brought together at various stages in the treatment operation.
Patent FI-79940-B (FI)
Inventor: PLOEGER WALTER
IPC: A61Q11/00
Filed: 1985-07-05
Granted: 1989-12-29
Abstract: A composition of matter useful as a polishing agent combination in a dentifrice, such as a toothpaste. A silica polishing agent is combined with a weakly calcined alumina polishing agent. Preferably, the weakly calcined alumina contains about 50%-90% by weight of alpha aluminum oxide and about 10%-50% by weight of gamma aluminum oxide. Preferably, the silica polishing agent is selected from the group consisting of precipitated silica and silica gel.
Patent FI-88885-B (FI)
Inventor: GRAVEMANN HORST
IPC: B22D11/06
Filed: 1989-05-16
Granted: 1993-04-15
Abstract: For the manufacture of casting moulds, which are subjected to a permanently changing temperature stress during casting, for example blocks of side dams of double strip steel casting installations or casting wheels, thermally highly conductive materials are required, which are insensitive to thermal shock treatment and additionally exhibit high thermal stability. According to the invention, a copper-based alloy is proposed for this application which, in addition to 1.6 to 2.4% of nickel, 0.5 to 0.8% of silicon and, if appropriate, up to 0.4% of chromium and/or up to 0.2% of iron, also contains 0.01 to 0.20% of zirconium. As a result of the additional content of zirconium, the thermal shock sensitivity of hitherto used alloys is eliminated.
Patent FI-101021-B (FI)
Inventor: POTTGEN PAUL A
IPC: G01N33/487
Filed: 1990-09-14
Granted: 1998-03-31
Abstract: The present invention relates to a novel method and apparatus for the amperometric determination of a analyte, and in particular, to an apparatus for amperometric analysis utilizing a novel disposable electroanalytical cell for the quantitative determination of biologically important compounds from body fluids.
Patent FI-108453-B (FI)
Inventor: DEPIERNE OTTO S
IPC: C08F220/06
Filed: 1992-02-05
Granted: 2002-01-31
Abstract: A process is disclosed for the preparation of styrene/acrylic type polymers which are useful in the sizing of paper. The process comprises polymerizing the monomers in an alcohol/water mixture at reflux temperature in the presence of a free-radical generating catalyst. The catalyst is added portion-wise over the course of the reaction and the resultant polymer is neutralized while substantially simulaneously separating the alcohol/water mixture and adding water to recover a product of less than 25% polymer solids.
Patent FI-117897-B (FI)
Inventor: HEINZ FRANZ XAVER
IPC: A61K38/00
Filed: 1995-07-26
Granted: 2007-04-13
Abstract: New complete cDNA (I), encoding an infectious tick-borne encephalitis virus (TBEV) RNA transcript is: (a) a 11141 bp sequence reproduced in the specification; or (b) a sequence with at least 70 (esp. 95)% homology with (a). Also new are: (1) cDNA (Ia) encoding infectious TBEV-RNA transcripts contg. the 3'-non-coding region (i.e. bases 10375-11141) of (a) plus the TBEV-coding sequence of a suitable TBEV strain; (2) cDNA (Ib) encoding infectious TBEV-RNA transcripts comprising the TBEV-coding part of (a) plus a 3'-non-coding sequence of a related flavivirus; (3) infectious RNA transcripts of (I), (Ia) or (Ib), produced in vivo or in vitro, (4) recombinant DNA consisting of (I), (Ia0 or (Ib), plus a vector and a promoter, (5) transformed/transfected prokaryotic or eukaryotic cells contg. such recombinant DNA.
Patent FI-105143-B (FI)
Inventor: PEDERSEN LONE
IPC: A01L1/02
Filed: 1995-10-05
Granted: 2000-06-30
Abstract: PCT No. PCT/SE94/00193 Sec. 371 Date Jan. 22, 1996 Sec. 102(e) Date Jan. 22, 1996 PCT Filed Mar. 7, 1994 PCT Pub. No. WO94/22296 PCT Pub. Date Oct. 13, 1994A horseshoe includes a core of metal which is surrounded by a plastic or rubber material. The horseshoe is provided with a number of apertures (10) which are intended for nails and which taper upwardly from the underside (4) of the horseshoe. In order to facilitate the correct alignment of the nails when these are driven into a horseshoe of relatively great vertical thickness, the center points of the largest and smallest sections of the aperture (10) are offset in a horizontal plane relative to one another in a direction towards or away from a central region (3) of the horseshoe. This offset may vary in both size and direction from one aperture to the next within the same horseshoe.
Patent FI-109532-B (FI)
Inventor: DORN CONRAD P
IPC: A61P25/22
Filed: 1996-06-14
Granted: 2002-08-30
Abstract: Substituted heterocycles of general structural formula (I) or a pharmaceutically acceptable salt thereof, wherein: R<1> is selected from the group consisting of: hydrogen; C1-6 alkyl, unsubstituted or substituted; C2-6 alkenyl, unsubstituted or substituted; C2-6 alkynyl; phenyl, unsubstitued or substituted; X is selected from the group consisting of: -O-, -S-, -SO-, -SO2-; Y is selected from the group consisting of: a single bond, -O-, -S-, -CO-, -CH2, -CHR5- and -CR<15>R<16>; Z = C1-6 alkyl, are tachykinin receptor antagonists useful in the treatment of inflammatory diseases, pain or migraine, asthma and emesis, and calcium channel blockers useful in the treatment of cardiovascular conditions such as angina, hypertension or ischemia.
Patent FI-107817-B (FI)
Inventor: TALJA MARTTI
IPC: D21H27/02
Filed: 1999-06-24
Granted: 2001-10-15
Abstract: A method and apparatus for making patterned paper. A printer (10, 10') patterning the paper is arranged in a patterning unit (4) arranged in a paper machine (1), the printer (10, 10') patterning a paper web (3) being made in the paper machine (1). The printer (10, 10') is preferably an ink-jet printer. The paper web (3) patterned by the patterning unit (4) can be coated by a coating unit (5) arranged in the paper machine (1).  <IMAGE>
Patent HU-197128-B (HU)
Inventor: SZABO LASZLO
IPC: H03J1/02
Filed: 1987-03-11
Abstract: Die Erfindung betrifft ein mit einer Skalenvorrichtung versehenes Abstimmpotentiometer, insbesondere fuer die Anwendung in elektronisch abstimmbaren Geraeten, das ein Abstimmpotentiometer, einen Skalenzeiger und eine Einrichtung zum Bewegen eines Abgriffarmes des Abstimmpotentiometers und des Skalenzeigers aufweist, wobei das Abstimmpotentiometer mit einer in einem Potentiometergehaeuse angeordneten Widerstandsbahn und einem entlang der Widerstandsbahn befindlichen Abgriffanschluss versehen ist. Das erfindungsgemaesse mit einer Skalenvorrichtung versehene Abstimmpotentiometer ist derart ausgebildet, dass eine Stirnwand (12) des Potentiometergehaeuses (11) eine Fuehrungsbahn (2 a) des Abgriffarmes (2) bildet, waehrend ein vor die Stirnwand (12) herausgefuehrter Vorsprung des Abgriffarmes (2) den Skalenzeiger (2 b) bildet, wobei der Abgriffarm (2) mit einem Befestigungsorgan (2 e) fuer die Skalenschnur, zum Beispiel einem Einziehelement fuer die Skalenschnur versehen ist. Fig. 2
Patent HU-205599-B (HU)
Title: Process for producing benzidine
Inventor: MESTER TAMAS
IPC: C07C211/50
Filed: 1990-03-06
Abstract: Hydrazobenzene- or hydrazobenzene extracted by toluene from a reaction mixt. resulting from a reaction between nitrobenzene aq. NaOH, a phase transfer catalyst and Pd activated hydrogen redn.-is isomerised to benzidine-sulphate in a mixt. of toluene and aq. sulphuric acid. - Opt. this cpd. is extracted and benzidine base is liberated with heating in a system of H2O and toluene. Benzidine is crystallised out from the toluene phase by cooling. (-pp)
Patent HU-204733-B (HU)
Title: Process for producing aluminium hydroxide with grain diameter less than 20% micrometers up to 20 per cent
Inventor: BAKSA GYOERGY
IPC: C01F7/04
Filed: 1987-03-31
Abstract: A sludge of alumina and caustic NaO2 soln. (135-155g/l) is mixed and heated. 30-70 m2Aluminium hydroxide/l of sludge, comprising min. 80% grain size above 45 microns is separated by controlled cooling at a rate of 0.05-0.2 deg.C/hour.
Patent HU-199844-B (HU)
Title: Process for producing aminophthalide isoquinoline derivatives
Inventor: TAKEDA YOSHIYUKI
IPC: C07C51/00
Filed: 1985-04-15
Abstract: Disclosed herein is an improved process for preparing 1RS-3 min -RS epimer of aminophthalideisoquinolines represented by the general formula (I): <CHEM> wherein R<1> and R<2> independently represent hydrogen atom or a lower alkoxy group, R<3> is a lower alkyl group, and R<4>, R<5> and R<6> independently represent a lower alkoxy group. The improvement comprises, in the first step of reacting trihydroxybenzoic acids with dialkyl sulfates, maintaining the pH of aqueous reaction media in the range of from 8.5 to 11, inclusive, by the addition of a caustic alkali.