NL7708939A - Esters met eigenschappen van vloeibare kristal- lijne materialen, alsmede inrichting, welke een of meer van dergelijke esters bevat. - Google Patents

Esters met eigenschappen van vloeibare kristal- lijne materialen, alsmede inrichting, welke een of meer van dergelijke esters bevat.

Info

Publication number
NL7708939A
NL7708939A NL7708939A NL7708939A NL7708939A NL 7708939 A NL7708939 A NL 7708939A NL 7708939 A NL7708939 A NL 7708939A NL 7708939 A NL7708939 A NL 7708939A NL 7708939 A NL7708939 A NL 7708939A
Authority
NL
Netherlands
Prior art keywords
esters
properties
liquid crystal
device containing
crystal line
Prior art date
Application number
NL7708939A
Other languages
English (en)
Other versions
NL187016C (nl
NL187016B (nl
Original Assignee
Secretary Industry Brit
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from GB33858/76A external-priority patent/GB1592147A/en
Application filed by Secretary Industry Brit filed Critical Secretary Industry Brit
Publication of NL7708939A publication Critical patent/NL7708939A/nl
Publication of NL187016B publication Critical patent/NL187016B/nl
Application granted granted Critical
Publication of NL187016C publication Critical patent/NL187016C/nl

Links

Classifications

    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C255/00—Carboxylic acid nitriles
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C43/00—Ethers; Compounds having groups, groups or groups
    • C07C43/02—Ethers
    • C07C43/20—Ethers having an ether-oxygen atom bound to a carbon atom of a six-membered aromatic ring
    • C07C43/202—Ethers having an ether-oxygen atom bound to a carbon atom of a six-membered aromatic ring the aromatic ring being a naphthalene
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C45/00—Preparation of compounds having >C = O groups bound only to carbon or hydrogen atoms; Preparation of chelates of such compounds
    • C07C45/45—Preparation of compounds having >C = O groups bound only to carbon or hydrogen atoms; Preparation of chelates of such compounds by condensation
    • C07C45/46—Friedel-Crafts reactions
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C51/00—Preparation of carboxylic acids or their salts, halides or anhydrides
    • C07C51/16—Preparation of carboxylic acids or their salts, halides or anhydrides by oxidation
    • C07C51/29—Preparation of carboxylic acids or their salts, halides or anhydrides by oxidation with halogen-containing compounds which may be formed in situ
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C51/00—Preparation of carboxylic acids or their salts, halides or anhydrides
    • C07C51/347—Preparation of carboxylic acids or their salts, halides or anhydrides by reactions not involving formation of carboxyl groups
    • C07C51/36—Preparation of carboxylic acids or their salts, halides or anhydrides by reactions not involving formation of carboxyl groups by hydrogenation of carbon-to-carbon unsaturated bonds
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
    • C09K19/00—Liquid crystal materials
    • C09K19/04—Liquid crystal materials characterised by the chemical structure of the liquid crystal components, e.g. by a specific unit
    • C09K19/06—Non-steroidal liquid crystal compounds
    • C09K19/08—Non-steroidal liquid crystal compounds containing at least two non-condensed rings
    • C09K19/30—Non-steroidal liquid crystal compounds containing at least two non-condensed rings containing saturated or unsaturated non-aromatic rings, e.g. cyclohexane rings
    • C09K19/3001—Cyclohexane rings
    • C09K19/3066—Cyclohexane rings in which the rings are linked by a chain containing carbon and oxygen atoms, e.g. esters or ethers
    • C09K19/3068—Cyclohexane rings in which the rings are linked by a chain containing carbon and oxygen atoms, e.g. esters or ethers chain containing -COO- or -OCO- groups
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
    • C09K19/00—Liquid crystal materials
    • C09K19/04—Liquid crystal materials characterised by the chemical structure of the liquid crystal components, e.g. by a specific unit
    • C09K19/06—Non-steroidal liquid crystal compounds
    • C09K19/32—Non-steroidal liquid crystal compounds containing condensed ring systems, i.e. fused, bridged or spiro ring systems
    • C09K19/322—Compounds containing a naphthalene ring or a completely or partially hydrogenated naphthalene ring

Landscapes

  • Chemical & Material Sciences (AREA)
  • Organic Chemistry (AREA)
  • Engineering & Computer Science (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Oil, Petroleum & Natural Gas (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Materials Engineering (AREA)
  • Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
  • Liquid Crystal Substances (AREA)
NLAANVRAGE7708939,A 1976-08-13 1977-08-12 Werkwijze ter bereiding van een vloeibaar kristalmateriaal alsmede gedraaide nematische cel, dynamische verstrooiingscel of elektro-optische inrichting met een vloeibaar kristalmateriaal. NL187016C (nl)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
GB33858/76A GB1592147A (en) 1976-08-13 1976-08-13 Trans-4-alkyl cyclohexane-1-carboxylic acid ester liquid crystal materials
GB1083977 1977-03-15

Publications (3)

Publication Number Publication Date
NL7708939A true NL7708939A (nl) 1978-02-15
NL187016B NL187016B (nl) 1990-12-03
NL187016C NL187016C (nl) 1991-05-01

Family

ID=26247796

Family Applications (1)

Application Number Title Priority Date Filing Date
NLAANVRAGE7708939,A NL187016C (nl) 1976-08-13 1977-08-12 Werkwijze ter bereiding van een vloeibaar kristalmateriaal alsmede gedraaide nematische cel, dynamische verstrooiingscel of elektro-optische inrichting met een vloeibaar kristalmateriaal.

Country Status (13)

Country Link
US (1) US4113647A (nl)
JP (1) JPS6048558B2 (nl)
AT (1) AT349000B (nl)
CA (1) CA1120491A (nl)
CH (1) CH639128A5 (nl)
DE (3) DE2736525A1 (nl)
DK (1) DK360077A (nl)
FR (1) FR2361455A1 (nl)
HK (1) HK15683A (nl)
IT (1) IT1126761B (nl)
MY (1) MY8300117A (nl)
NL (1) NL187016C (nl)
SE (1) SE441008B (nl)

Families Citing this family (69)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1592161A (en) * 1976-08-13 1981-07-01 Secr Defence Biphenyl carboxylic esters and their use as liquid crystal materials
GB1596012A (en) * 1976-08-16 1981-08-19 Secr Defence Optically active liquid crystal materials and liquid crystal devices containing them
GB1576106A (en) * 1976-11-25 1980-10-01 Secr Defence Temperature compensated liquid crystal devices
GB2009219B (en) * 1977-11-02 1982-04-28 Secr Defence Liquid ctystal material mixtures and devices incorporating such mixtures
US4291948A (en) * 1977-11-10 1981-09-29 International Standard Electric Corporation Liquid crystal display incorporating positive and negative smectic material
JPS5483694A (en) * 1977-12-16 1979-07-03 Hitachi Ltd Nematic liquid crystal body for display device
DE2800553A1 (de) * 1978-01-07 1979-07-12 Merck Patent Gmbh Cyclohexanderivate
US4261651A (en) * 1978-05-31 1981-04-14 The Secretary Of State For Defence In Her Britannic Majesty's Government Of The United Kingdom Of Great Britain And Northern Ireland Liquid crystal compounds
JPS54160350A (en) * 1978-06-08 1979-12-19 Seiko Epson Corp Ester compound
JPS5517363A (en) * 1978-07-25 1980-02-06 Seiko Epson Corp Ester compound
US4261652A (en) * 1978-08-04 1981-04-14 The Secretary Of State For Defence In Her Britannic Majesty's Government Of The United Kingdom Of Great Britain And Northern Ireland Liquid crystal compounds and materials and devices containing them
US4293434A (en) * 1978-08-08 1981-10-06 VEB Werk fur Fernsehelektronik Berlin im VEB Kombinat Mikroelektronik Liquid crystal compounds
JPS5534206A (en) * 1978-08-30 1980-03-10 Hitachi Ltd Nematic liquid crystal for display unit
DE2966302D1 (en) * 1978-09-13 1983-11-17 Secr Defence Brit Improvements in or relating to liquid crystal materials and devices
DE3014912A1 (de) * 1979-05-15 1980-11-27 Werk Fernsehelektronik Veb Nematische fluessigkristalline 5-cyan- 2- eckige klammer auf 4-acyloxyphenyl eckige klammer zu -pyrimidine und diese enthaltende gemische
DE2933563A1 (de) * 1979-07-18 1981-02-05 Bbc Brown Boveri & Cie Anisotrope verbindungen mit negativer dk-anisotropie
DE2933611A1 (de) * 1979-07-18 1981-02-12 Bbc Brown Boveri & Cie Cyclohexylcyclohexanoate
ATE1993T1 (de) * 1979-07-20 1982-12-15 Bbc Aktiengesellschaft Brown, Boveri & Cie. Anisotrope carbonsaeure-4-cyclohexylphenylester und sie enthaltende fluessigkristallmischungen.
FR2461697A1 (fr) * 1979-07-20 1981-02-06 Suwa Seikosha Kk 3-cyano-4-alcoxybenzoate de 2-chloro-4-alcoylphenyle et son utilisation dans une composition de cristaux liquides
DE2933544A1 (de) * 1979-08-18 1981-03-26 Kabushiki Kaisha Suwa Seikosha, Shinjuku, Tokio/Tokyo Esterverbindung
EP0025119B1 (de) * 1979-08-20 1983-05-25 VEB Werk Für Fernsehelektronik im VEB Kombinat Mikroelektronik Nematische kristallin-flüssige 5-Alkyl-2-(4-acyloxyphenyl)-pyrimidine für optoelektronische Anordnungen und Verfahren zu ihrer Herstellung
US4328116A (en) * 1979-11-01 1982-05-04 Minnesota Mining And Manufacturing Company Liquid crystal compositions for multiplexed displays
US4309304A (en) * 1979-11-01 1982-01-05 Exxon Research & Engineering Co. Liquid crystal compositions for multiplexed displays
DE2949080A1 (de) * 1979-12-06 1981-06-11 Merck Patent Gmbh, 6100 Darmstadt Naphthalinderivate, diese enthaltende dielektrika und elektrooptisches anzeigeelement
US4290905A (en) * 1979-12-26 1981-09-22 Kabushiki Kaisha Suwa Seikosha Ester compound
US4357078A (en) * 1980-01-30 1982-11-02 The Secretary Of State For Defence In Her Britannic Majesty's Government Of The United Kingdom Of Great Britain And Northern Ireland Liquid crystal compounds containing an alicyclic ring and exhibiting a low dielectric anisotropy and liquid crystal materials and devices incorporating such compounds
JPS56122334A (en) * 1980-02-29 1981-09-25 Chisso Corp Liquid crystal 4-alkylcyclohexyl ester
US4366080A (en) * 1980-04-07 1982-12-28 Tokyo Shibaura Denki Kabushiki Kaisha Liquid crystal display element
JPS574960A (en) * 1980-06-09 1982-01-11 Chisso Corp 4'''-cyanobiphenyl trans-4-(trans-4'-alkylcyclohexyl)- cyclohexanecarboxylate
JPS5721359A (en) * 1980-07-15 1982-02-04 Chisso Corp 4'''-cyano-4"-biphenylyl 4-(trans-4'-alkylcyclohexyl)benzoate
GB2085910B (en) * 1980-10-13 1985-05-22 Secr Defence A liquid crystal composition comprising a mixture of diester(s) and cyclohexane derivative(s)
EP0060646B1 (en) * 1981-03-13 1985-10-09 The Secretary of State for Defence in Her Britannic Majesty's Government of the United Kingdom of Great Britain and Liquid crystal compositions
US4406814A (en) * 1981-04-10 1983-09-27 Eaton Corporation Liquid crystalline materials and optical displays utilizing same
DE3221462A1 (de) * 1981-06-18 1983-01-05 F. Hoffmann-La Roche & Co AG, 4002 Basel Fluessigkristallines gemisch
DE3151356A1 (de) * 1981-12-24 1983-07-07 Merck Patent Gmbh, 6100 Darmstadt 4-fluorbiphenylderivate, verfahren zu ihrer herstellung, diese enthaltende dielektrika und elektrooptisches anzeigeelement
JPS58140045A (ja) * 1982-02-15 1983-08-19 Kanto Kagaku Kk 液晶化合物，液晶組成物並びに液晶表示素子
DD203561A1 (de) * 1982-03-08 1983-10-26 Dietrich Demus Unterkuehlbare nematische fluessigkristallgemische
DE3225290A1 (de) * 1982-07-07 1984-01-12 Merck Patent Gmbh Ringverbindungen
US4550981A (en) * 1982-09-30 1985-11-05 Hoffmann-La Roche Inc. Liquid crystalline esters and mixtures
JPS5973555A (ja) * 1982-10-20 1984-04-25 Seiko Epson Corp エステル−アゾキシ化合物
DE3377219D1 (en) * 1982-11-26 1988-08-04 Hitachi Ltd Smectic liquid crystal compounds and liquid crystal compositions
EP0115693B1 (en) * 1983-01-06 1987-08-26 Chisso Corporation Liquid crystalline compounds and mixtures thereof
CH653051A5 (de) * 1983-01-27 1985-12-13 Merck Patent Gmbh Nematische fluessigkristallmischung mit einer negativen dielektrischen anisotropie.
DE3333677A1 (de) * 1983-09-17 1985-04-04 Merck Patent Gmbh, 6100 Darmstadt Fluessigkristall-phase
US4623477A (en) * 1983-10-07 1986-11-18 Chisso Corporation Ester compounds having a pyrimidine ring
JPS60112741A (ja) * 1983-11-24 1985-06-19 Hitachi Ltd 液晶性化合物，液晶組成物及び液晶表示素子
US4659501A (en) * 1984-01-30 1987-04-21 Chisso Corporation 2-cyano-4-halogenophenyl substituted-benzoates
DE3405914A1 (de) * 1984-02-18 1985-08-22 Merck Patent Gmbh, 6100 Darmstadt Fluessigkristalline verbindungen
DE3490788C2 (nl) * 1984-11-14 1988-08-04 Nii Prikladnych
WO1986004324A1 (en) * 1985-01-22 1986-07-31 MERCK Patent Gesellschaft mit beschränkter Haftung Smectic a liquid crystal compositions
GB8501509D0 (en) * 1985-01-22 1985-02-20 Secr Defence Esters
US4605510A (en) * 1985-01-25 1986-08-12 Nauchno-Issledovatelsky Institut Prikladnykh Problem Imeni A.N. Sevchenko Liquid crystal composition for electrooptical devices for presentation of information
US4605520A (en) * 1985-01-25 1986-08-12 Nauchno-Issledovatelsky Institut Prikladnykh Fizicheskikh Problem Imeni A.N. Sevchenko Liquid crystal 4-(4'-cyanodiphenyl) esters of trans-4"-N-alkylocyclohex-2-enecarboxylic acids
US4680137A (en) * 1985-06-10 1987-07-14 Chisso Corporation Liquid crystal ester compound
JPS6287556A (ja) * 1985-10-14 1987-04-22 Chisso Corp エステル化合物
GB8610349D0 (en) * 1986-04-28 1986-06-04 Bdh Ltd 6-hydroxy-2-naphthoic acid derivatives
US5254747A (en) * 1986-06-30 1993-10-19 Minnesota Mining And Manufacturing Company Fluorine-containing chiral smectic liquid crystals
CA1294954C (en) * 1986-12-26 1992-01-28 Masakatsu Nakatsuka Optically active naphthalene derivatives
GB8909489D0 (en) * 1989-04-26 1989-06-14 Merck Patent Gmbh Liquid crystalline composition
JPH0380877A (ja) * 1989-08-24 1991-04-05 Miyota Seimitsu Kk 光誘導ペースメーカーユニット
JP2890759B2 (ja) * 1989-09-08 1999-05-17 住友化学工業株式会社 光学活性なナフタレン誘導体、その製造法、それを有効成分とする液晶組成物およびこれを用いてなる液晶素子
ATE118523T1 (de) * 1990-07-19 1995-03-15 Mitsui Petrochemical Ind Flüssigkristall-racematmischung, flüssigkristallzusammensetzung und flüssigkristallelement, verfahren zur herstellung und verwendung.
US5702637A (en) * 1995-04-19 1997-12-30 Minnesota Mining And Manufacturing Company Liquid crystal compounds having a chiral fluorinated terminal portion
US5658491A (en) * 1995-10-12 1997-08-19 Minnesota Mining And Manufacturing Company Process for controlling cone tilt angle in mixtures of smectic liquid crystal compounds
US5855812A (en) * 1997-04-11 1999-01-05 Minnesota Mining And Manufacturing Company Compounds and process for controlling cone tilt angle in mixtures of smectic liquid crystal compounds
US6309561B1 (en) 1997-12-24 2001-10-30 3M Innovative Properties Company Liquid crystal compounds having a chiral fluorinated terminal portion
JP4779182B2 (ja) * 1999-05-28 2011-09-28 Ｄｉｃ株式会社 ネマチック液晶組成物及びこれを用いた液晶表示装置
WO2000017287A1 (fr) * 1998-09-21 2000-03-30 Dainippon Ink And Chemicals, Inc. Composition de cristaux liquides nematiques et ecran a cristaux liquides utilisant cette composition
CN109917579B (zh) * 2019-04-18 2021-02-09 深圳赛科显示器有限公司 适用于rpdlc液晶显示器的液晶体材料及其透明rpdlc液晶显示屏

Family Cites Families (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
BE787198A (fr) * 1971-08-07 1973-02-05 Merck Patent Gmbh Composes et melanges nematiques
US3915883A (en) * 1972-04-26 1975-10-28 Eastman Kodak Co Liquid crystalline compounds and compositions
US3953491A (en) * 1972-08-19 1976-04-27 Merck Patent Gesellschaft Mit Beschraenkter Haftung Phenyl esters of 4-benzoyloxybenzoic acid
GB1433130A (en) * 1972-11-09 1976-04-22 Secr Defence Substituted biphenyl and polyphenyl compounds and liquid crystal materials and devices containing them
GB1452826A (en) * 1973-10-17 1976-10-20 Secr Defence Liquid crystal compositions
DD105701A1 (nl) * 1973-07-02 1974-05-05
US3925237A (en) * 1974-06-28 1975-12-09 Rca Corp Novel liquid crystal electro-optic devices
US3951846A (en) * 1974-06-28 1976-04-20 Rca Corporation Novel liquid crystal electro-optic devices
DE2538865A1 (de) * 1974-09-03 1976-03-11 Beckman Instruments Inc Nematische fluessigkristallmassen
US4017416A (en) * 1974-10-11 1977-04-12 Chisso Corporation P-cyanophenyl 4-alkyl-4'-biphenylcarboxylate, method for preparing same and liquid crystal compositions using same
GB1507030A (en) * 1974-10-21 1978-04-12 Secr Defence Liquid crystal display devices
DE2450088A1 (de) * 1974-10-22 1976-04-29 Merck Patent Gmbh Biphenylester
US4013582A (en) * 1976-06-17 1977-03-22 Rca Corporation Liquid crystal compounds and electro-optic devices incorporating them
US4029595A (en) * 1976-09-17 1977-06-14 Rca Corporation Novel liquid crystal compounds and electro-optic devices incorporating them
DD138473A3 (de) * 1977-02-11 1979-11-07 Deutscher Hans Joachim Kristallin-fluessige substanzen

Also Published As

Publication number Publication date
NL187016C (nl) 1991-05-01
HK15683A (en) 1983-05-20
FR2361455B1 (nl) 1982-07-09
NL187016B (nl) 1990-12-03
ATA590977A (de) 1978-08-15
DE2760452C2 (nl) 1989-08-03
CA1120491A (en) 1982-03-23
DE2736525C2 (nl) 1990-07-05
US4113647A (en) 1978-09-12
MY8300117A (en) 1983-12-31
DK360077A (da) 1978-02-14
AT349000B (de) 1979-03-12
DE2760451C2 (nl) 1990-07-05
JPS6048558B2 (ja) 1985-10-28
SE7709091L (sv) 1978-02-14
FR2361455A1 (fr) 1978-03-10
CH639128A5 (de) 1983-10-31
IT1126761B (it) 1986-05-21
JPS5322882A (en) 1978-03-02
DE2736525A1 (de) 1978-03-02
SE441008B (sv) 1985-09-02

Similar Documents

Publication Publication Date Title
NL7708939A (nl) Esters met eigenschappen van vloeibare kristal- lijne materialen, alsmede inrichting, welke een of meer van dergelijke esters bevat.
IT1073905B (it) Cristallo liquido e dispositivo che lo impiega
MY8300119A (en) Optically active liquid.crystal materials and liquid crystal devices containing them
NL7415006A (nl) Vloeibare-kristalweergeefinrichting.
NL183679C (nl) Vloeibaarkristal-afbeeldinrichting.
NO138794C (no) Anordning for sortering av vaeskebeholdere
NL7414646A (nl) Opneem- en/of weergeefinrichting van het cassettetype.
NL7903430A (nl) Opneem- en/of weergeefapparaat.
AT356720B (de) Elektro-optische anzeigevorrichtung
AT351613B (de) Fluessigkristall-anzeigevorrichtung
NL7709573A (nl) Vloeistofbeluchtingsinrichting.
NL7708941A (nl) Vloeibare kristallijne materialen, alsmede dergelijke kristallijne materialen bevattende inrichtingen.
NL7903431A (nl) Opneem- en/of weergeefapparaat.
NL7904377A (nl) Opneem- en/of weergeefapparaat.
TR19753A (tr) Sivi ve kati maddelerin ayrilmasina mahsus tertibat
NL7902990A (nl) Bandopneem- en/of -weergeefinrichting.
IT1011220B (it) Procedimento e dispositivo per vaporizzare un combustibi le liquido
NL7510462A (nl) Meervoudig gelaagde optische informatieschij- ven en weergave-inrichting.
AT356190B (de) Fluessigkristallanzeige
NL7809288A (nl) Vloeibare kristalmaterialen en inrichtingen, die deze materialen bevatten.
JPS5293738A (en) Liquid crystal substance and pielectrics
NL7614449A (nl) Bandopneem en/of weergeefinrichting.
NL7713006A (nl) Opneem- en/of weergeefinrichting.
CH613600B (de) Fluessigkristallanzeige.
AT356722B (de) Fluessigkristall-anzeigevorrichtung

Legal Events

Date Code Title Description
BA A request for search or an international-type search has been filed
BB A search report has been drawn up
BC A request for examination has been filed
A85 Still pending on 85-01-01
V4 Discontinued because of reaching the maximum lifetime of a patent

Free format text: 970812