Classifications

• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
  • C07C323/00—Thiols, sulfides, hydropolysulfides or polysulfides substituted by halogen, oxygen or nitrogen atoms, or by sulfur atoms not being part of thio groups
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10M—LUBRICATING COMPOSITIONS; USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION
  • C10M135/00—Lubricating compositions characterised by the additive being an organic non-macromolecular compound containing sulfur, selenium or tellurium
  • C10M135/20—Thiols; Sulfides; Polysulfides
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10M—LUBRICATING COMPOSITIONS; USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION
  • C10M135/00—Lubricating compositions characterised by the additive being an organic non-macromolecular compound containing sulfur, selenium or tellurium
  • C10M135/20—Thiols; Sulfides; Polysulfides
  • C10M135/28—Thiols; Sulfides; Polysulfides containing sulfur atoms bound to a carbon atom of a six-membered aromatic ring
  • C10M135/30—Thiols; Sulfides; Polysulfides containing sulfur atoms bound to a carbon atom of a six-membered aromatic ring containing hydroxy groups; Derivatives thereof
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10M—LUBRICATING COMPOSITIONS; USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION
  • C10M159/00—Lubricating compositions characterised by the additive being of unknown or incompletely defined constitution
  • C10M159/12—Reaction products
  • C10M159/20—Reaction mixtures having an excess of neutralising base, e.g. so-called overbasic or highly basic products
  • C10M159/22—Reaction mixtures having an excess of neutralising base, e.g. so-called overbasic or highly basic products containing phenol radicals
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10M—LUBRICATING COMPOSITIONS; USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION
  • C10M2219/00—Organic non-macromolecular compounds containing sulfur, selenium or tellurium as ingredients in lubricant compositions
  • C10M2219/02—Sulfur-containing compounds obtained by sulfurisation with sulfur or sulfur-containing compounds
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10M—LUBRICATING COMPOSITIONS; USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION
  • C10M2219/00—Organic non-macromolecular compounds containing sulfur, selenium or tellurium as ingredients in lubricant compositions
  • C10M2219/08—Thiols; Sulfides; Polysulfides; Mercaptals
  • C10M2219/082—Thiols; Sulfides; Polysulfides; Mercaptals containing sulfur atoms bound to acyclic or cycloaliphatic carbon atoms
  • C10M2219/087—Thiols; Sulfides; Polysulfides; Mercaptals containing sulfur atoms bound to acyclic or cycloaliphatic carbon atoms containing hydroxy groups; Derivatives thereof, e.g. sulfurised phenols
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10M—LUBRICATING COMPOSITIONS; USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION
  • C10M2219/00—Organic non-macromolecular compounds containing sulfur, selenium or tellurium as ingredients in lubricant compositions
  • C10M2219/08—Thiols; Sulfides; Polysulfides; Mercaptals
  • C10M2219/082—Thiols; Sulfides; Polysulfides; Mercaptals containing sulfur atoms bound to acyclic or cycloaliphatic carbon atoms
  • C10M2219/087—Thiols; Sulfides; Polysulfides; Mercaptals containing sulfur atoms bound to acyclic or cycloaliphatic carbon atoms containing hydroxy groups; Derivatives thereof, e.g. sulfurised phenols
  • C10M2219/088—Neutral salts
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10M—LUBRICATING COMPOSITIONS; USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION
  • C10M2219/00—Organic non-macromolecular compounds containing sulfur, selenium or tellurium as ingredients in lubricant compositions
  • C10M2219/08—Thiols; Sulfides; Polysulfides; Mercaptals
  • C10M2219/082—Thiols; Sulfides; Polysulfides; Mercaptals containing sulfur atoms bound to acyclic or cycloaliphatic carbon atoms
  • C10M2219/087—Thiols; Sulfides; Polysulfides; Mercaptals containing sulfur atoms bound to acyclic or cycloaliphatic carbon atoms containing hydroxy groups; Derivatives thereof, e.g. sulfurised phenols
  • C10M2219/089—Overbased salts
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10M—LUBRICATING COMPOSITIONS; USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION
  • C10M2221/00—Organic macromolecular compounds containing sulfur, selenium or tellurium as ingredients in lubricant compositions
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10M—LUBRICATING COMPOSITIONS; USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION
  • C10M2221/00—Organic macromolecular compounds containing sulfur, selenium or tellurium as ingredients in lubricant compositions
  • C10M2221/02—Macromolecular compounds obtained by reactions of monomers involving only carbon-to-carbon unsaturated bonds
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10M—LUBRICATING COMPOSITIONS; USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION
  • C10M2221/00—Organic macromolecular compounds containing sulfur, selenium or tellurium as ingredients in lubricant compositions
  • C10M2221/04—Macromolecular compounds obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds
  • C10M2221/043—Polyoxyalkylene ethers with a thioether group
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10M—LUBRICATING COMPOSITIONS; USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION
  • C10M2225/00—Organic macromolecular compounds containing phosphorus as ingredients in lubricant compositions
  • C10M2225/04—Organic macromolecular compounds containing phosphorus as ingredients in lubricant compositions obtained by phosphorisation of macromolecualr compounds not containing phosphorus in the monomers
  • C10M2225/041—Hydrocarbon polymers
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10N—INDEXING SCHEME ASSOCIATED WITH SUBCLASS C10M RELATING TO LUBRICATING COMPOSITIONS
  • C10N2070/00—Specific manufacturing methods for lubricant compositions
  • C10N2070/02—Concentrating of additives

Definitions

• a lubricating oil composition containing sulfurized normal calcium alkylphenolate detergent dispersant of improved anticorrosive properties and resistance to oxidation said dispersant prepared by a three-step procedure comprising 1) reacting at a temperature between about 200 and 425 F. in the presence of a hydrocarbon lubricating oil an alkylphenol with a first addition of calcium alkoxyalkoxide utilizing between about 45 and 90 wt.
• the lubricant compositions of the invention contain a compound which has a calcium component linked to a carbon through oxygen and preferably containing in addition thereto a detergent dispersant for lube oil composed of carbon, hydrogen, oxygen, phosphorus and sulfur.
• Lubricating oils subjected to severe stress such as railway diesel engine lubricating oils readily deteriorate under such conditions with attendant formation of sludge, lacquer, resinous materials which adhere to the engine parts, particularly the piston ring groove, thereby lowering the operating efficiency of the engine.
• certain chemical additives have been found which added to lubricating oils have the ability to keep the deposit forming materials suspended in oil so that the engine is kept clean and in efficient operating condition for extended periods of time. These agents are known in the art as detergents and/or dispersants.
• Metal organic compounds are particularly useful in this respect.
• One class of metal organic compounds which have been found so useful are the calcium sulfurized normal alkylphenolates. It is to be noted that the term normal employed hereinbefore and hereinafter denotes the ratio of the number of equivalents of calcium moiety, the number of equivalents of alkylphenol moiety is about 1, that is, the calcium ratio is about 1.
• a lubricant composition is formed which substantially reduces engine bearing wear and is substantially more resistant to oxidation as measured by change in the lubricating oil viscosity after being subjected to severe engine conditions.
• A is a divalent saturated aliphatic hydrocarbon radical (alkanediyl) of 1 to 6 carbons and R is alkyl of from 1 to 25 carbons at a temperature between about 200 and 425 F., preferably between about 320 and 425 F., utilizing a mole ratio of calcium alkoxyalkoxide to alkylphenol of between about 0.225 :1 and 0.45:1, that is, an amount of a calcium alkoxyalkoxide of between about 45 and 90 wt. percent of stoichiometric.
• the reaction period is conducted until essentially all the alkoxyalkoxide has reacted which is generally between about 0.5 and 8 hours.
• inert gas blowing until no detectable H S odor is found which is normally measured at less than 3 p.p.m. H 8 and a copper strip corrosion (ASTM D130) of 2A maximum (3 hrs-212 F.).
• a gas rate of between about 0.1 to 10 s.c.f.h./ gallon is advantageously employed.
• the carbon dioxide functions as a deodorizing agent whereas the iner gas blowing until no detectable H 8 odor is found tiles.
• the total reaction time in the second stage generally ranges between about 0.5 and 10 hours.
• the third stage contacting the gas blown second reaction mixture with a second amount of calcium alkoxyalkoxide at a temperature between about 350 and 425 F., preferably between about 400 and 425 F., utilizing between about 0.15 and 0.375 mole of calcium alkoxyalkoxide per mole of original alkylphenol, the first and second additions totaling between about 100% and 120% of stoichiometric.
• the third stage reaction time is generally between about 0.5 and 8 hours.
• All three stages of the reaction are preferably conducted in the presence of a hydrocarbon lubricating oil medium which is also suitable to function to form a portion of the base oil in the final compositions containing the sulfurized normal calcium alkylphenolate.
• Suitable base oils and diluent oils include a wide variety of hydrocarbon lubricating oils such as naphthenic base, parafiinic base and mixed naphthenic and paraffinic base oils having an SUS viscosity at 100 F. of between about 50 and 2500, preferably between about 90 and 150.
• the finished compositions desirably have an SUS viscosity between about 900 and 1100 at 100 F.
• the diluent oil normally constitutes between about 25 and 80 wt. percent of the reaction mixture.
• the calcium alkoxyalkoxide reactant is introduced into the reaction system as a solution if not already in liquid form to facilitate reactant contact.
• the solvent medium is usually the corresponding alkoxyalkanol (if liquid) of the alkoxyalkoxide component.
• concentration of the calcium alkoxyalkoxide in the solvent medium is advantageously between about 20 and 60 wt. percent.
• the solvent is normally removed as overhead during the early phase of each stage.
• the sulfur is desirably introduced as a slurry in a hydrocarbon lubricating oil, such slurry most preferably having a sulfur content between about 10 and 25 wt. percent.
• a hydrocarbon lubricating oil such slurry most preferably having a sulfur content between about 10 and 25 wt. percent.
• the first and third stage reactions are preferably conducted in an inert gas atmosphere, e.g., employing inert gas blowing (0.1-10 s.c.f.h./ gallon). Further, agitation is normally employed in all three stages of the procedure in order to facilitate ingredient content.
• the final product is advantageously filtered, if desired, by standard means.
• the preferred filtration is accomplished by adding to the final reaction mixture between about 0.01 and 1 wt. percent diatornaceous earth and passing material to be filtered through press leaf filter precoated with diatornaceous earth at a temperature between about 200 and 300 F. and a pressure between about and 100 p.s.i.g.
• the formed sulfurized normal calcium alkylphenolate product contents in the lubricating oil compositions contemplated herein range anywhere from 0.1 to 90 wt. percent.
• the higher concentrations, e.g., between about and 90 wt. percent sometimes referred to in the art as concentrates are normally found in lubricant compositions resulting directly from the manufacture of the sulfurized normal calcium alkylphenolate, whereas the sulfurized calcium alkylphenolate ingredients in finished (dilute) lubricating oil compositions employed for engine use is desirably between about 0.1 and 7.5 wt. percent with a calcium concentration of between about 0.06 and 0.5 wt. percent, preferably between about 0.1 and 0.4 wt. percent.
• the entire percent range of the additive in the lubricating composition will function as a detergent-dispersant and the resultant composition will at least have some lubricating function.
• additives may be included such as pour depressors, antioxidants, silver corrosion inhibitors, viscosity index improvers, oleogeneous agents and mixtures thereof.
• pour depressors antioxidants
• silver corrosion inhibitors silver corrosion inhibitors
• viscosity index improvers oleogeneous agents
• oleogeneous agents oleogeneous agents
• Exactly what other additives are included in the finished oil and the particular amounts therein will of course depend on the particular use the finished oil product is to be put to.
• One of the most suitable uses found for the sulfurized normal calcium alkylphenolate produced herein are lubricants for railway diesel engines. When this is the case, it is desirable to include in the oil in addition to the aforedescribed sulfurized calcium alkylphenolate, ethoxylated inorganic phosphorus acid free, steam hydrolyzed, polybutene-P S reaction products further described in US. Pats.
• the ethoxylated product is present in the finished compositions of the invention in amounts between about 0.3 and 6 wt. percent (oil free basis), preferably between about 0.8 and 4 wt. percent, and in any case, in sufficient amount to give a phosphorus content in the finished (dilute) composition of between about 0.006 and 0.15 wt. percent, preferably between about 0.01 and 0.08 wt. percent.
• the sulfurized calcium alkylphenolate ethoxylated polybutene-P S containing finished formulations are normally prepared by blending a Inbricating oil concentration of the sulfurized alkylphenolate in a lubricating oil concentrate of the ethoxylated polybutene-P S reaction product and then diluting the resultant mixture with additional hydrocarbon lubricating oil until the desired concentration of the additive is ob tained.
• a most-preferred finished composition contains both additives wherein the calcium content is between about 0.01 and 0.4 wt. percent, and a phosphorus content between about 0.05 and 0.08 wt. percent.
• alkylphenol reactants contemplated herein are 4 octylphenol, 4-t-octylphenol, 2- decylphenol, Z-dodecylphenol, 4-hexadecylphenol, 3,4- didodecylphenol, 2-nonylphenol, 4-tricontylphenol, 4- eicosylphenol and a mixture of decyl and dodecyl phenol (Q +C alkylphenol) and a mixture of 2 and 4 posit1oned monoalkyl and dialkylphenols.
• the alkylphenols employed will normally be p-alkylphenols, however, 2,4-substituted alkylphenols may also be employed.
• the only restriction is l-ortho or para positions of the alkylphenol reactant is desirably available for sulfurization.
• Examples of the calcium alkoxyalkoxide reactants contemplated herein are calcium Z-methoxyethoxide, calcium 2-methoxypropoxide, calcium 3-methoxybutoxide, calcium 2-ethoxyethoxide and calcium 4-dodecoxyhexoxide.
• Their corresponding alkoxyethanol diluents are 2- methoxyethanol, Z-methoxypropanol, S-methoxybutanol, 2-ethoxyethanol and 4-dodecoxyhexanol.
• the inert gas normally employed is nitrogen and, most preferably, nitrogen with a purity of at least about 99 wt. percent.
• polybutene denotes, derivatives of isobutene as well as butene.
• the inorganic phosphorus acids are removed from the hydrolyzed product prior to reaction with alkene oxide via standard procedures such as those disclosed in U.S. 2,987,512 and U.S. 2,951,835 wherein removal is effected by contact withsynthetic hydrous alkaline earth metal silicates and synthetic hydrous alkali metal silicates, respectively.
• Inorganic phosphorus acids can also be removed by extraction with anhydrous methanol as disclosed in U.S. 3,135,729. Steam hydrolyzed inorganic phosphorus acid product is then contacted with ethylene oxide at a temperature between about 140 and 300 F.
• ethylene oxide is removed after completion of the reaction by blowing the reaction mixture at an elevated temperature, generally with inert gas such as nitrogen.
• the foregoing reactions are conducted in the presence of a hydrocarbon lubricating oil described in connection with the sulfurized normal calcium alkylphenolate.
• the lubracting oil normally Specific examples of the ethoxylated derivative of the reaction mixture.
• the introduction of the hydrocarbon lubricating oil normally takes place subsequent to steam hydrolysis.
• the ethoxylated derivative on an oil free basis normally has a sulfur content of between about 2 and 5 wt. percent and a phosphorus content of between about 4 and 6 wt. percent.
• ethoxylated deriavtive of the inorganic phosphorus acid free, steam hydrolyzed polybutene-P 8 reaction product are ethoxylated steam hydrolyzed polyisobutene (1100 M.W.)-P S reaction product, ethoxylated, steam hydrolyzed polybutene (1500 M.W.)-P S reaction product, ethoxylated, steam hydrolyzed polybutene (800 M.W.)-P S reaction product, ethoxylated, steam hydrolyzed polyisobutene (2000 M.W.)-P S reaction product where the ethylene oxide component and the reaction product component are present in a mole ratio of 1:1.
• the excess monoalkylated phenol ensures the tying up of all the calcium reagent so there is none to react with the acidic sulfur by-product formed during sulfurization, these by-products being removed as overhead in the second stage.
• the additional calcium reagent introduced in the third step reacts with the leftover monoalkylated phenol and any dialkylated phenol which may be present.
• the final product which employs the bracketing calcium alkoxyalkoxide treatment rather than reacting all the calcium alkoxyalkoxide prior to sulfurization produces a product having a greater total base number per unit calcium, that is, a greater alkaline calcium activity. Greater alkalinity produces a less corrosive product of greater detergent dispersancy and less undesired viscosity increase under engine conditions.
• EXAMPLE I This example illustrates the preparation of the product of the invention.
• the resultant mixture was heated with stirring to a temperatureof about 350 F. under a blanket of nitrogen and grams (0.25 mole calcium) of a 34 wt.
• the product yield was 658 grams (95 wt. percent of theory).
• An analysis of the product determined it to be a lube oil solution of sulfurized calcium dodecylphenolate, the solution giving the following analysis: wt. percent Ca: 2.62; wt. percent S: 2.55; TBN (total base number): 81.
• Example IV The concentrates prepared in Example III were utilized to formulate finished lubricant compositions and the finished compositions were subjected to a well known railway diesel lube oil oxidation test. In the test procedure a copper-lead surface bearing is inserted in test oil. The oil is kept at 285 F. and the air (5 liters/hour) is bubbled through for 72 hours. At the end of the test the bearing weight loss (BWL) and viscosity increase of the oil are measured. Normal limits for the test are 50 mg. BWL
• a lubricating oil composition comprising a ma or amount of a hydrocarbon oil of lubricating viscosity conthe formula:
• R is alkyl of from 5 to 50 carbons with a first addition of calcium alkoxyalkoxide of the formula:
• CatO-A-OR' 2 where A is alkanediyl of from 1 to 6 carbons and R is alkyl from 1 to 25 carbons at a first temperature between about 200 and 425 F. utilizing a mole ratio of said calcium alkoxyalkoxide to said alkylphenol of between about 0.255 :1 and 0.45:1, second contacting the resultant mixture with sulfur in the presence of a hydrocarbon lubricating oil at a second temperature between about 350 and 425 F.
• ratio of calcium alkoxyalkoxide to initial alkylphenol of between about 0.15:1 and 0.37 5:1 in sufficient amount so that the total calcium alkoxyalkoxide employed in the first and third contacting will total a mole ratio of calcium alkoxyalkoxide to initial alkylphenol of between about 0.5:1 and 0.621.
• a lubricating oil composition in accordance with claim 1 containing between about 0.1 and 7.5 wt. percent of said sulfurized normal calcium alkylphenolate.
• a lubricating oil composition in accordance with claim 1 containing between about 0.1 and 7.5 wt. percent of said sulfurized normal alkylphenolate and between about 0.3 and 6 wt. percent of an ethoxylated inorganic phosphorus acid free, steam hydrolyzed, polybutene (800- 2500 M.W.)-P S reaction product, said ethylene oxide 10 mioety being present in respect to said steam hydrolyzed po1ybutene-P S reaction product in a mole ratio of about 1:1 and the polybutene-P S components being present in a mole ratio to one another of between about 1:1.
• Col. l line 66, change "actually" to -actuality-.

Landscapes

• Chemical & Material Sciences (AREA)
• Organic Chemistry (AREA)
• Chemical Kinetics & Catalysis (AREA)
• General Chemical & Material Sciences (AREA)
• Oil, Petroleum & Natural Gas (AREA)
• Lubricants (AREA)
• Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)

Applications Claiming Priority (1)

Publications (1)

Family

ID=22661900

Family Applications (1)

Country Status (10)

Cited By (9)

Families Citing this family (1)

• 1971
  • 1971-09-15 US US00180829A patent/US3761414A/en not_active Expired - Lifetime
• 1973
  • 1973-07-04 GB GB3182973A patent/GB1377320A/en not_active Expired
  • 1973-07-11 AU AU57975/73A patent/AU472816B2/en not_active Expired
  • 1973-07-12 SE SE7309804A patent/SE384034B/xx unknown
  • 1973-07-12 DE DE19732335519 patent/DE2335519A1/de active Pending
  • 1973-07-17 JP JP48079991A patent/JPS5028504A/ja active Pending
  • 1973-07-18 NL NL7309981A patent/NL7309981A/xx not_active Application Discontinuation
  • 1973-07-23 BE BE133785A patent/BE802696A/fr unknown
  • 1973-07-27 FR FR7327582A patent/FR2238702B1/fr not_active Expired
  • 1973-08-01 CA CA177,907A patent/CA979423A/en not_active Expired

Also Published As

Similar Documents