baber/WOPTO huggingface dataset:
Patent JO-1332-B1 (JO)
Title: Apparatus for taking liquid samples
Inventor: MAURICE JOUANNIC
Filed: 1984-08-18
Granted: 1986-11-30
Abstract: The invention concerns an apparatus for taking liquid samples from a mixture of liquid and solid.
Patent KR-790001139-B1 (KR)
Title: Process for the preparation of benzimidazolyl piperidine derivatives
Inventor: KOZIMA HIROSHI
Filed: 1975-06-11
Granted: 1979-09-04
Abstract: Benzimidazoles (I; Q = -CHAr-, carbonyl, Ar = phenyl, halophenyl, R2 = H, lower alkyl) or their salts, useful as neuroleptics, were prepd. by heating benzimidazolyl piperidine (III) with Ar-Q-CH2 CH2CH2-R' (II; R1 = ether residues of halogen or hydroxy) at 50-170≰C and treating with a general method to give free acid base and inorganic acid or organic acid base of I.
Patent KR-800000295-B1 (KR)
Title: Circuit for maintaining operating point stabilty of an amplifier
Inventor: WILLIS D
IPC: H01J29/52
Filed: 1975-09-05
Granted: 1980-04-10
Abstract: Amplifier for driving a color image reproducing device comprises a first transistor(46a) whose base is capacitively coupled to a source of color difference signals.  The emitter of the first transistor is DC coupled to the base of a second transistor(48a).  The emitter of the second transistor is coupled to a source of a predetd. voltage. The capacitive coupling device(54a) and the second transistor form a clamping cct. for maintaining the voltage developed at the emitter of the first transistor which is substantially independent of DC condition of the source of color difference signals and baseto-emitter voltage variations of the first transistor.
Patent KR-810001183-B1 (KR)
Title: Electron gun structure
Inventor: ANEZAKI YOSHIMITSU
IPC: H01J29/02
Filed: 1977-08-02
Granted: 1981-09-25
Abstract: The electron gun for use in cathode ray tube comprises a cathode electrode(20) having a sleeve(20) with electron emitting face(11), a heater(14) seated in the cathode electrode(20) and a support(24) for supporting the heater(14).  The cathode electrode(20) is set closer to the support(24) than the distance between the heater(14) and the cathode electrode (20).  Discharge starting voltage between the cathode electrode and the support is set lower than the discharge voltage between the heater and the cathode electrode, so that the discharge phenomenon toward the heater is prevented.
Patent KR-800000485-B1 (KR)
Title: Method for catalyst regeneration
Inventor: IMMEL O
IPC: B01J21/20
Filed: 1977-08-30
Granted: 1980-06-04
Abstract: Used carbon-supported boric acid catalysts were regenerated with air at 400-700≰C in fluid bed formanufacture of caprolactam from cyclohexanone oxime. Thus, 150kg of used boric acid/carbon catalysts were passed through a fluid bed regeneration column heated to 580≰C for 10 min, and then regenerated in 200 Nm air at 600≰C, 0.6 m/sec for 20 min. Obtained catalysts with high activity, were circulated to the manufg. caprolactams.
Patent KR-820000190-B1 (KR)
Title: Catalyst for producing ethylene oxide
Inventor: COGNION J
IPC: B01J23/50
Filed: 1978-11-09
Granted: 1982-03-04
Abstract: A catalyst support is impregnated with a soln. of Ag anthranilate(I), Ag picolinate, Ag salicylate, or a similar salt or complex of Ag, and the salt or complex is decompd. to form Ag which is distributed, uniformly on the support and provides good selectivity to ethylene oxide(II) during oxidn. of ethylene to II.  Thus, 42.5g alumina was impregnated with 300 mL pyridine contg. 18g I, and the I was decompd. at 280≰C to prep. a catalyst which was used to oxidize ethylene at 218≰C, giving 10% conversion and 67% selectivity to II.
Patent KR-820001467-B1 (KR)
Title: Blended fuel tank containing oil and fuel supplying means
Inventor: NOMURA KAJUHIKO
IPC: F01M3/00
Filed: 1979-04-27
Granted: 1982-08-21
Abstract: A device for the providing of the blended fuel tank(11) which has adhered automatic blending fuel system, the blending fuel system having a blending device as automatically and readily blending the fuel and lubricating oil.  The device was connected through blending fuel tank and lubricating oil tank(12) that installed on one side the fuel inlet(116).  The exhausting system of measured lubricating oil was installed, and then it operated in accordance with oil feeding control.
Patent KR-800001629-B1 (KR)
Title: Process for the preparation of benzylamines
Inventor: NOLL K
Filed: 1979-07-16
Granted: 1980-12-31
Abstract: About 67 title compds. (I; R1 = H; R2 = Br, Cl; R3 = F, CH3O, acetyl, CCl3 CN, carboethoxy; R4, R5, = H, Me, Et, Pr, Bu, t-Bu, cyclohexyl, benzyl) were prepd. by halogenation of II.  Thus, 3 g 2-amino-N-cyclohexyl-5-fluoro-N-methyl-benzyl-amine in 300 mlo CH3COOH was reacted with 1098 g Br2 in 300ml CH3COOH to give 2-amino-N-bromocyclohexyl-5-fluoro-n-methyl-benzylamine.  When 50 mg/kg and 100mg/kg of IHCI (R1 = H; R2 = Br; R3 = carbethoxy; R4, R5 = ethyl) was administered orally to female rats, the ulcer was decreased by 52%, 79%, resp.
Patent KR-800001370-B1 (KR)
Title: Automatic control device for a car head-light
Inventor: PARK JONG KOO
IPC: B60Q1/08
Filed: 1979-09-19
Granted: 1980-11-17
Abstract: Aheadlight control device of vehicle for preventing the vehicle accident at night is equipped with three photoconductive cells ; the first cell(Cdsl) detecting velocity and headlight brightness of opposite vehicles to control the brightness of upward headlight(HL), the second cell(Cds2) determining whether this device is installed or not and intensifying the brightness of upward headlight(HL) when not installed, the third cell (Cds3) switching the downward headlight (LL) automatically according to the brightness of headlight of opposite vehicles.
Patent KR-860001515-B1 (KR)
Title: Process of replication and translation of human pre-growth hormone
Inventor: BAXTER JOHN D
IPC: B44C3/02
Filed: 1980-05-31
Granted: 1986-09-30
Abstract: DNA transfer vector(I) with deoxynucleotide sequence(II) coding for human pre-growth hormone was constructed. Pref. (II) was derived from mRNA isolated from the pituitary gland cells of an individual human. Microbes transformed by (I) were able to synthesize a protein comprising human pre-growth hormone. New chimeric protein comprises the amino acid sequence of human pregrowth hormone as its C-terminal sequence, and a portion (III) of a procargotic protein as its N- terminal sequence. (III) was coded by part of the trpD gene of E. coli.
Patent KR-830000997-B1 (KR)
Title: Method for producing the sintered hard metal
Inventor: TOBIOKA MASAKI
IPC: B22F3/00
Filed: 1982-04-13
Granted: 1983-05-24
Abstract: A molecular formula is expressed by (MA, MB, MC) (Cu, Nv)X, after the composite carbonizing nitride having crystal structure of B-1 type contg. w by one of the composed element, WC above 50wt % of the total weight of the cement carbide, and metal of the iron group is mixed, the cement carbide is sintered. Only M is expressed above the first element or the second element of IVa group metal, M' is above the first element of the second element of Va group metal, M" is above the first or the second element of VIIa group metal, c is carbon, N is nitrogen, x is ration composed metal element to composed nonmetal element, and A, B, C, U and V atomic ratio each other.
Patent KR-880001560-B1 (KR)
Title: Hydrogenation process
Inventor: BRADLEY MICHAEL WILLIAM
IPC: C07C31/12
Filed: 1982-08-20
Granted: 1988-08-22
Abstract: A new method of hydrogenation reaction in vapor phase of aldehydes to produce corresponding alcohols is presented.  Using many adiabetic reaction chambers and low mole ratio of total hydrogen/aldehyde in vapor stream, a smaller compressor can be used and nonhomogeneous catalytic-stream hydrogenation reaction is developed.
Patent KR-870002184-B1 (KR)
Title: Method & apparatus for thermomechanically rolling hotstrip product to a controlled microstructure
Inventor: THOMAS J EDWARD
IPC: C21D8/02
Filed: 1983-07-13
Granted: 1987-12-28
Abstract: Hot strip mill includes a final reducing stand and an incubator positioned along a runout table intermediate first and second cooling zones.  Processing involves (i) reducing the strip in the final reduction stand to a predetermined thickness (pref. to a finishing temp. above the A3 temp.); (ii) cooling the strip in the first cooling zone to a given temp. (pref. below the A3 temp.); (iii) cooling the strip in the incubator; (iv) holding the strip in the incubator for a given time and temp. (pref. between the Al and A3 temps. to equalise temp. and nucleate ferrite); (v) decoiling the strip out of the incubator; and (vi) cooling the strip in the second cooling zone.
Patent KR-860000005-B1 (KR)
Title: Automatic stud driving tool
Inventor: MCKEAN JOHN A
IPC: B25B21/02
Filed: 1983-10-21
Granted: 1986-01-30
Abstract: The tool comprises a hollow tubular body(10) contg. a rotatable bush (40) of which the inner bore (38) contains two semicylindrical axially movable and non-rotatable gripper members(50). These members can swivel from an open release position to a closed position to hold a stud. The bush is axially movable between a lower position and an upper position when its tang engages a slot in the bottom of the drive head (30). The tool is used by the motor vehicle and furniture industries. The small external dia. permits use in confined spaces, with improved reliability.
Patent KR-870001070-B1 (KR)
Title: Process for preparing bis-esters of dicarboxylic acids with amoxicillin and certain hydroxymethylpenicillanate 1,1-dioxide
Inventor: JASYS VYTAUTAS JOHN
IPC: C07D519/00
Filed: 1984-03-30
Granted: 1987-05-27
Abstract: The title compds. having formula (I) or its pharmaceutic ally acceptable salts are new.  In the formula (I), X=H, H2NCH2; Y=H, HOCH2; Z=alkylene contg.  1,4-cyclohexylene or C1-6. (I) are derivs from beta-lactamase and penicilline.  (I) are such as 1,4dyclohexanedicarboxylic acid and alkane dicarboxylic acid(bisester), dervis from hydroxymethylpenicillanate 1,1-dioxide or its 6-beta-hydroxymethyl or 6-alpha-aminomethyl derivs. and 6-[D-(2amino-2-(p-hydroxyphenyl)acetamido)! penicillanate.
Patent KR-910009798-B1 (KR)
Inventor: SEKOGUCHI MASAHARU
IPC: B60C15/06
Filed: 1984-03-30
Granted: 1991-11-30
Abstract: 내용 없음.
Patent KR-850001206-B1 (KR)
Title: Process for preparing cephem derivatives
Inventor: KIM WON-JU
IPC: C07D501/36
Filed: 1984-04-27
Granted: 1985-08-20
Abstract: The title compds(I; R2 = H, acetoxymethyl, (1-methyltetrazole-5-yl) thiomethyl, or (2,5-dihydro-2-methyl-hydroxy-5oxo-as-triazine-3-yl) thiomethyl; R3   = benzotriazolyl), useful as antibacterial agents, were prepd. Thus,  2.0 g  2-(2amionothiazole-4-yl)-2-syn- methoxyiminoacetic  acid was reacted with 35ml N,N-dimethylformamide and 0.8 ml pyridine at room  temp. The product was then reacted with 6.0 g 1,1'-(carbonyldioxy) dibenzotriazole  for 12 hrs. to give 3.02 g 2-(2-aminothiazole4-yl)-2-syn-methoxyiminoacetic  acid benzotriazole  ester (yield 95%).
Patent KR-890001107-B1 (KR)
Title: Process for preparing zn - fe base alloy electroplated steel strips
Inventor: KYONO KAZUAKI
IPC: C25D5/26
Filed: 1984-11-03
Granted: 1989-04-24
Abstract: The plated steel sheet is produced by cathodically electrolysing a steel sheet in a chloride type plating bath containing at least 6.0 mol/l of Cl- ion, 1.0 mol/l  solubility limit of Zn2+ and 1.0 mol/l solubility limit of Fe2+ ion with the proviso that the weight ratio of Fe2+/Zn2+ is 0.10-0.35 at the pH 1.0-6.0 with the current density of 80-200 A/dm2 and at the relative speed between the steel sheet and the plating bath 30-200 m/min.  The plating bath may contain 0.005- 0.5 mol/l of polybasic carboxylic acid or salt and/or 0.0005-0.05 mol/l of hypophosphorus acid or salt.
Patent KR-890002821-B1 (KR)
Title: Pilfer-proof plastic closure for containers
Inventor: MORI FUMIO
IPC: B65D41/34
Filed: 1985-01-17
Granted: 1989-08-04
Abstract: A pilfer-proof plastic closure has break-off skirt lower section with double inclination intermal flaps (26).  The pilferproof plastic closure of a vessel has a mouth-neck portion that has a outer-screw peak out outer surface and holding jaw portion at lower section of the outer screw peak (64).  The closure are consisted by a top panel and a circular skirt portion that are prolonged downward from the top panel.  The skirt portion forming a prolonged cutting line with respect to circumference (46).  The circumference divides main section and the pilter-ploof floor section (14) of the skirt wall.
Patent KR-920008187-B1 (KR)
Inventor: OHTA JIRO
IPC: F03B11/06
Filed: 1985-05-10
Granted: 1992-09-25
Abstract: 내용 없음.
Patent KR-890000204-B1 (KR)
Title: Electron-beam tubes
Inventor: KYON KI-BONG
IPC: H01J31/00
Filed: 1985-08-31
Granted: 1989-03-10
Abstract: The method for testing the CRT functions does not seal between a bulb and an electron-gun but an intermediate box (1) which contains a flange (3) for joining the bulb (4), a flange (8) for joining the electron-gun (G), and an evacuation pipe (14) is placed.  When testing, the air in the bulb, box and electron-gun is evacuated upto 10-5 torr by a vacuum pump after joining them. After testing the CRT, N2 gas is filled up through a pipe (15).
Patent KR-900000753-B1 (KR)
Title: Method and apparatus for forming glass sheets
Inventor: MCMASTER HAROLD A
IPC: C03B23/03
Filed: 1985-11-08
Granted: 1990-02-15
Abstract: (a) a first curved mould in a heated chamber for engaging the sheet at a first position to provide initial forming; (b) an actuator for horizontally moving the first mould and the glass sheet on it to a second position; and (c) a second curved mould in the same chamber for engaging the glass sheet from above at the second position to form the glass sheet further.  The products have been accurately formed in even form.
Patent KR-910002464-B1 (KR)
Inventor: NAKAKI MASHASI
IPC: C08F20/04
Filed: 1985-11-21
Granted: 1991-04-23
Abstract: 내용 없음.
Patent KR-940004864-B1 (KR)
Inventor: ORTON MICHAEL L
IPC: C08L75/04
Filed: 1986-01-25
Granted: 1994-06-02
Abstract: 내용 없음.
Patent KR-960001560-B1 (KR)
Inventor: ROBISHAW ALCES P
IPC: E01D21/00
Filed: 1986-07-22
Granted: 1996-02-02
Abstract: 내용 없음.
Patent KR-900000984-B1 (KR)
Title: Earth resistance measure method and system
Inventor: CHO SEUNG-KI
IPC: G01R27/20
Filed: 1986-09-11
Granted: 1990-02-23
Abstract: The method for measuring the ground resistance of the power line not disconnecting the ground line or not utilizing an auxiliary ground pole applies the voltage having particular frequency to the ground line utilizing a hook current transformer and detects the applied voltage by a current transformer.  The transformer unit comprising transformers, one for applying the voltage and another for detecting the current, and the other for detecting the contacting state of the transformers, is integrated in one body.
Patent KR-890004072-B1 (KR)
Title: Foaming system for phenolic foams
Inventor: WOLINSKI LEON M
IPC: C08J9/14
Filed: 1986-12-10
Granted: 1989-10-18
Abstract: A foamable phenolic resin compn. is composed of a mixt. of a foamable rigid phenol-formaldehyde resin and a fluorocarbon blowing agent system selected from blends of (a) a fluorocarbon consisting of trichlorotrifluoroethane (CFC-113) and mixts. of this with (6) dichlorotrifluoroethane (CFC-123 or CFC-123a) and mixts. of these in a ratio of CFC-123 or CFC-123a to CFC-113 of ca. 1:9 to ca. 3:7 and in which the total blowing agent is present in amts. of ca. 2-40 wt.% to the wt. of the phenol-formaldehyde resin.  The mixed CFC-113/CFC- 123 and/or CFC-123a blowing agents have an improved solubility in phenolic resin.
Patent KR-940004801-B1 (KR)
Inventor: FREEMAN RICHARD B
IPC: B29K105/08
Filed: 1987-04-20
Granted: 1994-06-01
Abstract: 내용 없음.
Patent KR-910008780-B1 (KR)
Inventor: ARMELLIN GIANCARLO
IPC: B60C3/04
Filed: 1987-06-05
Granted: 1991-10-21
Abstract: 내용 없음.
Patent KR-930004407-B1 (KR)
Inventor: NAIDA HIDEO
IPC: F25D11/02
Filed: 1987-07-10
Granted: 1993-05-27
Abstract: 내용 없음.
Patent KR-900002407-B1 (KR)
Title: Dust collection apparatus for dust car
Inventor: KIM JANG-SUB
IPC: B65F7/00
Filed: 1987-08-04
Granted: 1990-04-14
Abstract: The dirt collector of a cleaning vehicle is used for effectively/ hygienically collecting dirt without scattering dirt while the vehicle is cleaning roads.  The dirt collector comprises a rotatable rod (6) connecting a rod bracket (5) to a bracket (3) fixed on a frame (2) with a bolt (7), a rotatable brush shaft (8) installed on a main body (4), a drawer type dirt vessel (11) having a knob (12), a wire pulley (14), an adjusting wheel (17) having a bearing (18), and a support member (16).  A belt (22) is joined crosswise between a wheel (21) and a fore belt pulley (19), and a belt (24) being joined parallel between a wheel (23) and a rear belt pulley (19).
Patent KR-900003486-B1 (KR)
Title: Vcmr system
Inventor: YUN JONG-KYUNG
IPC: H04N5/907
Filed: 1987-09-24
Granted: 1990-05-19
Abstract: The system includes A/D converters (16-18) for digitizing green chromatic aberration signal (B-Y), red chromatic aberration signal (R-Y), and brightness control signal, data condensing circuit (19-20) for condensing and recording digital signals from the converters on memory devices (28-30) after selecting coding method, a controller (25) for controlling the condensing circuits and memory devices (28- 30) so that the horizontal and vertical part of the frame is recorded on the memory devices, a switch (27) for selecting field data or frame data, and a switch (24) for selecting input signal come from termirals X1 and X2 and for transmitting to the controller (25)
Patent KR-920006526-B1 (KR)
Inventor: GABRIEIS ANDRE
IPC: F42C15/30
Filed: 1987-10-06
Granted: 1992-08-07
Abstract: 내용 없음.
Patent KR-930005759-B1 (KR)
Title: Time controllable electronic range using timer
Inventor: PARK MYONG-JONG
IPC: H05B6/66
Filed: 1987-12-22
Granted: 1993-06-24
Abstract: The cooker for a proper cooking by enabling  user  to  set  a cook time interval comprises: a key-pad (4) including four  burner select switches (S1-S4); a microprocessor controlled burner  power control unit (2) for applying power  to  the  burners  (B1-B4);  a motor driven timer switch (TSW1) which is ON after a predetermined time interval for turning off all burners regardless of the  other key-pad switch input status.
Patent KR-960012198-B1 (KR)
Inventor: FINDEISEN KURT
IPC: C07D249/14
Filed: 1988-03-23
Granted: 1996-09-16
Abstract: 내용없음
Patent KR-940010387-B1 (KR)
Inventor: TAJIMA IKUO
IPC: G05B19/409
Filed: 1988-07-14
Granted: 1994-10-22
Abstract: 내용 없음.
Patent KR-900008750-B1 (KR)
Inventor: HONZYOU MASAHIRO
IPC: H03D3/00
Filed: 1988-07-21
Granted: 1990-11-29
Abstract: 내용 없음.
Patent KR-910005721-B1 (KR)
Title: Displaying device and its controlling method for vehicle
Inventor: LEE WOO-YEOL
IPC: B60Q11/00
Filed: 1988-08-12
Granted: 1991-08-02
Abstract: The displaying system comprises a brake pedal section (1) for changing the resistance value in accordance with  the  motions  of pedal,  brake  switch   section   (2)   consisting   of   switches (SW,SW2,SW3,SW4) sensing section (11) for detecting  the  velocity of vehicle. The input transformation  circuit  (3)  generates  the high or low level signal in sesponse to the input-signal from  the portion (1,2,11). A comparater (12)  generates  the  high  or  low signal ofter comparing the signal from the circuit  (3)  with  the signal coming through A/D converter (10)  from  the  microcomputer control portion (4).
Patent KR-920003756-B1 (KR)
Inventor: MCCARTNEY CHARLES P JR
IPC: H01M2/12
Filed: 1988-09-01
Granted: 1992-05-09
Abstract: 내용 없음.
Patent KR-960013580-B1 (KR)
Inventor: KOCHKA EDGAR L
IPC: C30B15/34
Filed: 1988-09-08
Granted: 1996-10-09
Abstract: 내용 없음.
Patent KR-960000196-B1 (KR)
Inventor: OBAYASHI HISASHI
IPC: C05G3/60
Filed: 1988-09-22
Granted: 1996-01-03
Abstract: 내용 없음.
Patent KR-920005388-B1 (KR)
Inventor: TANAKA TOSHINORI
IPC: F02N15/06
Filed: 1988-10-07
Granted: 1992-07-02
Abstract: 내용 없음.
Patent KR-960011192-B1 (KR)
Inventor: DOHARA KAZUNOBU
IPC: A01N53/00
Filed: 1988-12-15
Granted: 1996-08-21
Abstract: 내용 없음.
Patent KR-920002073-B1 (KR)
Title: Apparatus for expanding data memory
Inventor: KANG CHUNG-HOON
IPC: G06F12/06
Filed: 1988-12-16
Granted: 1992-03-10
Abstract: The circuit for extending the data memory area restricted  by address signal from a CPU to transmit or receive data to or from a main memory, comprises AND gates (G1,G2) for combining  a  writing signal (SA) and a reading signal (SB) from the CPU with an address signal fromthe CPU and an extension address generating  unit  (30) for outputting a predetermined address signal by data  signal  and address signal from the CPU. An extension memory (20) designates a memory allocati area  by  the  address  signal  fromthe  extension address generating unit (30), and writes and  reads  data  by  the signals (SA)(SB) from the gates (G1,G2) to transmit or receive the data to or from the main memory (10) through a data bus (DB).
Patent KR-910003002-B1 (KR)
Inventor: PELT CHRISTOPHER K V
IPC: B41L21/12
Filed: 1988-02-11
Granted: 1991-05-15
Abstract: 내용 없음.
Patent KR-960004145-B1 (KR)
Inventor: TARBOX ELEANOR JOAN
IPC: H04B10/2581
Filed: 1989-01-11
Granted: 1996-03-27
Abstract: 내용 없음.
Patent KR-910006286-B1 (KR)
Title: Separation method of alpha-l-aspartyl-l-phenylalanine methyl ester
Inventor: AJIOKA MASANOBU
IPC: A23L27/30
Filed: 1989-03-11
Granted: 1991-08-19
Abstract: A method for separating  alpha -L-aspartyl-L-phenylalanine methyl ester ( alpha -APM) from a solution containing  alpha -APM and impurities associated with the production thereof which comprises adding a mineral acid or an organic sulfonic acid to the solution in an organic carboxylic acid or in a solvent containing an organic carboxylic acid, and isolating the pure salt of  alpha -APM which precipitates therefrom.
Patent KR-920009449-B1 (KR)
Inventor: HOASHI KOICHI
IPC: G06F13/362
Filed: 1989-04-14
Granted: 1992-10-16
Abstract: 내용 없음
Patent KR-890003402-B1 (KR)
Title: High strength low carbon dual phase steel rods and wires and process for making same
Inventor: THOMAS GARETH
IPC: B21C1/00
Filed: 1989-06-28
Granted: 1989-09-20
Abstract: High strength, low C dual phase steel wire is produced from a steel containing (wt.%) about 0.05-0.15C, about 1.0-3.0 Si, which is heated for complete austenitisation and quenched to 100% martensite.  The martensitic steel is heated to a temperature in the two phase alpha+gamma range for sufficient time to transform the martensite to a volume ratio of ferrite and austenite which will give 10-40 vol.% martensite and 60-90 vol.% ferrite on quenching. The quenched steel is cold drawn by a reduction up to 99.9%.
Patent KR-0126469-B1 (KR)
Title: Optically active 1,3-dioxolane derivatives containing a mesogene group in position 4. method for their preparation and theiruse as doping agents in liouid-crystal mixtures
Inventor: GUNTER SCHEROWSKY
IPC: C09K19/58
Filed: 1989-07-21
Granted: 1997-12-24
Abstract: Optically active 1,3-dioxolane derivates of the general formula <IMAGE> which carry a mesogenic radical in the 4-position are suitable as dopes in - in particular ferroelectric - liquid-crystal mixtures. The symbols in the general formula have the following meanings: R<1> has a structure analogous to the moiety of the general formula on the right of X or is an alkyl or alkylene radical, which may be substituted, R<2>, R<3> and R<4> are H or alkyl (R<4> is alternatively alkenyl), which may also be substituted [R<2> and R<3>, together with the C(2) of the dioxolane ring, may alternatively be cycloaliphatic or keto groups], j, l and n are zero, 1 or 2, and k and m are zero or 1, with the proviso that n is zero if k is zero, m is zero if n is zero, and 1 </= j + l + n </= 3, -A<1>, -A<2> and -A<3> are an aromatic, heterocyclic or aliphatic ring system, -M<1> and -M<2> are -CO-O, -O-CO, -CH2CH2, -CH=CH, -CH2O, -OCH2 or -C IDENTICAL C and  X is O, S or O-CO-O. The particular advantage of the compounds of the general formula (I) is that they are able to induce a high twisting power in the cholesteric phase, but without significantly affecting the magnitude of the spontaneous polarisation already present in the mixture in the smectic C<*> phase. They are therefore suitable for pitch compensation, in particular for ferroelectric liquid-crystal mixtures.