EP2082014B1 - Watch - Google Patents

Description

Description for the following Contracting State (s): AT, BE, CH, DK, ES, IT, LI, LU, MC, NL, SE

The present invention relates to a watch, in particular to a mechanical watch, of which at least some of the moving parts are lubricated by agents with a very low coefficient of friction.

It is known that one of the major problems that arises in watchmaking, particularly in the field of the chronometer wristwatch, is to ensure as low a friction as possible between the moving parts relative to each other, account given the low energy reserve available.

Usually, the lubrication is ensured between the parts in relative motion, generally steel and ruby, by oils well known in the technical field considered, which produce low coefficients of friction, for example <0.1 at the temperature of 23 ° C. In this respect, mention may be made of the oil known under the name of oil 941, in addition to other lubricants which may also be used, in particular synthetic polyalphaolefin (PAO) type oil mixtures comprising as additives glycerol monooleate ( GMO).

As described elsewhere by Kano et al, Tribology Letters 18 (2) February 2005 it has proved possible to obtain even better friction coefficients, typically ≤ 0.06, preferably ≤ 0.05, at the temperature of 80 ° C., by inserting a film of carbon between the friction surfaces, that is to say by combining the deposition of a hard carbon film on at least one of the sliding surfaces with the use of an additive -OH group such as GMO in the lubricant. In this paper, it is question of sliding of surfaces containing -OH groups and the authors make the hypothesis, that they indicate immediately as being to verify by analytical works, that the -OH groups slide against each other by being hooked on the surface via the film containing groups C.

However, it was quickly noticed that the interposition of a film containing carbon, if it gave excellent results for the friction of parts working at high temperature, for example at 80 ° C, in particular in automobile engines, did not suit however for parts working at low temperature as in watchmaking. The lubrication obtained shows no progress compared with traditional lubrication.

US 2,355,616 describes a watch of which some of the moving parts are lubricated by an alcohol or polyol.

Surprisingly, it was found that much better results could be achieved by removing the intermediate carbon layer, and by directly associating one or more oxide surfaces having an affinity for the hydrophilic groups and a compound containing one or more several hydrophilic groups. This is precisely the subject of the invention, which therefore concerns a watch, in particular a mechanical watch, of which at least some of the moving parts are lubricated by agents with a very low coefficient of friction. We will discuss here and in the following the statement of "very low coefficient of friction" for values of this coefficient less than or equal to 0.06.

Such a watch includes a first relatively sliding piece on a second piece, the first piece being formed of oxide or having an oxide layer on the surface, the sliding surface having a chemical affinity with hydrophilic groups, as well as, on the sliding surface of the first part, at least one compound containing one or more hydrophilic groups chosen from C ₃ -C ₉ polyols having at least one-third of -OH groups relative to the number of carbon atoms.

This compound may be a mixture and may contain, for example, another substance containing hydrophilic groups, such as water.

The C ₃ -C ₉ polyol may be chosen for example from the group comprising glycerol (C ₃ H ₈ O ₃ ), propylene glycol (C ₃ H ₈ O ₂ ), diethylene glycol (C ₄ H ₁₀ O ₃ ), 1,6-hexanediol (C ₆ H ₁₄ O ₂ ), 1,2,6-hexanetriol (C ₆ H ₁₄ O ₃ ), triethylene glycol (C ₆ H ₁₄ O ₄ ), diglycerol (C ₆ H ₁₄ O ₅ ), triglycerol (C ₉ H ₂₀ O ₇ ), triethanolamine (C ₆ H ₁₅ NO ₃ ). As can be seen, the carbon chain of the polyol may comprise O or N.

Glycerol is a C ₃ alcohol containing 3 -OH groups, propylene glycol a C ₃ alcohol containing 2 -OH groups, diethylene glycol a C ₄ alcohol comprising 2 -OH groups and 1 O atom in the chain, 1,6-hexanediol a C ₆ alcohol comprising 2 -OH groups, 1,2,6-hexanetriol a C ₆ alcohol comprising 3 -OH groups, triethylene glycol a C ₆ alcohol comprising 2 -OH groups and two O atoms in the chain, the diglycerol a C ₆ alcohol comprising 4 -OH groups and 1 O atom in the chain, the triglycerol a C ₉ alcohol comprising 5 -OH groups and 2 O atoms in the chain and triethanolamine a C ₆ alcohol comprising 3 -OH groups and an N atom.

The second surface may also have a chemical affinity with hydrophilic groups and be, for example formed of oxide or have on the surface an oxide layer, as well as the first surface. It can also be metallic or metal alloy.

Thus, one of the relative sliding parts may be ceramic, in particular alumina or zirconia, more particularly ruby or sapphire, and the other relatively sliding parts may be made of iron, steel, for example steel 20AP , or other alloy of iron, or of brass, aluminum, titanium, cuproberyllium, silicon, nickel, nickel-phosphorus or their alloys. The part in question may be a part having a surface coating, obtained for example by galvanic deposition of gold, gold-copper-cadmium and gold, nickel, rhodium, tin-nickel. It may also have an anodized surface, as in the case of aluminum alloy parts or titanium. It can also be modified by a surface treatment such as oxidation, carburization or nitriding. Between the two relatively sliding parts may also be an intermediate layer called "epilame", well known in the watch industry and used to prevent the spreading of lubricants.

It is thus possible to achieve excellent sliding between a pallet of ruby or zirconia anchor and a steel escapement wheel, or alternatively between a steel shaft and a ruby or zirconia bearing.

Preferably, the compound comprising one or more hydrophilic groups is a low molecular weight polyol, for example glycerol or aqueous glycerol. This compound acts as a lubricant forming a film or film between the two moving surfaces.

The exceptional slip properties obtained by the interaction between hydrophilic groups and oxygen groups by means of hydrogen bonds are explained. It is also possible that the forces of Van der Waals also intervene in the phenomenon.

The invention will be better understood with reference to Examples 1 to 16 which follow, given in a non-limiting manner, and to the single appended figure. These examples, for better readability, are included in the form of a single table which is completed by a comparative example 17 for ethylene glycol and a series of comparative examples 18 to 24.

Examples 1 to 6 indicate the results obtained with aqueous glycerol on various pairs of surfaces, while Examples 7 to 17 give the results obtained with compounds other than glycerol for the same pair of 20AP steel-ruby surfaces.

These results were obtained on an alternative rectilinear tribometer, using a pion and a disk for a normal force of 1.5 N corresponding to a Hertz pressure of 0.8 GPa, and a speed of 61.2 mm / s, for ten thousand cycles (ie a total stroke of 200 m) at least. Each value is an average of at least 3 trials. The temperature is typically 23 ° C and the relative humidity is typically 35%. The quantity of lubricant deposited is 1 μl. By cycle is meant a round-to-back rubbing of one piece against the other.

The coefficient of friction, a standard measure in watchmaking, expresses the dynamic friction and corresponds to the ratio between the tangential force exerted to maintain the relative movement between the two parts and the perpendicular force exerted on them.

20AP steel is a hardening carbon steel made of 1% carbon, 0.4% manganese, 0.2% lead, 0.15% silicon, 0.05% sulfur, and iron for the balance. The term "epilamed 20AP steel" is intended to denote a 20AP steel on which a conventional epilame has been deposited, in this case that sold under the trademark Fixodrop FK / BS-10 by Moebius et Fils in Allschwil (Switzerland).

Ruby is a synthetic ruby as commonly used in watchmaking and "85% glycerol" means a liquid composed of glycerol at 85% by weight and 15% by weight of water (mutatis mutandis for Examples 13, 14 and 16). ).

"941 Oil" is a commercial oil manufactured by the same Moebius Company and is a mixture of one alkyl-aryl monooleate and two C ₁₀ -C ₁₃ diesters with anti-wear and extreme pressure additives; its viscosity measured at 20 ° C is 100 mm ² / s.

"PAO + GMO" is a blend of polyalphaolefin synthetic oils (PAO) with a viscosity measured at 20 ° C of 100 mm ² / s, and 1% of GMO additive (glycerol monooleate).

Finally "DLC", for "diamond like carbon", denotes a layer of very hard diamond-like carbon deposited in the vapor phase, with reference to the Kano article cited above. Board Lubricant Material of the pawn Material of the disc Coef. friction 1 Glycerol 85% 20AP steel Ruby 0.02 2 Glycerol 85% Ruby 20AP steel 0.02 3 Glycerol 85% Ruby Ruby 0.03 4 Glycerol 85% Ruby Yes 0.06 5 Glycerol 85% Ruby Neither electroformed 0.04 6 Glycerol 85% Ruby Epilamated 20AP steel <0.02 7 100% glycerol Ruby 20AP steel <0.02 8 1,2,6-hexanetriol Ruby 20AP steel 0.05 9 Propylene glycol Ruby 20AP steel 0.05 10 triethanolamine Ruby 20AP steel 0.05 11 Triethylene glycol Ruby 20AP steel 0.05 12 α-α'-Diglycerol Ruby 20AP steel 0.06 13 Triglycerol 68% Ruby 20AP steel 0.06 14 1,6-hexanediol 86% Ruby 20AP steel 0.06 15 Diethylene glycol Ruby 20AP steel 0.06 16 1,6-hexanediol 67.5% Ruby 20AP steel 0.06 17 Ethylene glycol Ruby 20AP steel 0.10 18 dried up 20AP steel Ruby 0.64 19 dried up 20AP + DLC steel Ruby 0.17 20 dried up 20AP + DLC steel Ruby + DLC 0.09 21 941 oil 20AP steel Ruby 0.08 22 941 oil 20AP + DLC steel Ruby 0.09 23 PAO + GMO 20AP steel Ruby 0.08 24 PAO + GMO 20AP + DLC steel Ruby 0.08

On reading the table, we can only see the excellent results obtained and the lowering of the coefficient of friction values compared to the solutions of comparative examples 18 to 24 serving as reference values, the "dry" examples corresponding to the sliding Direct piece against piece, except the example 20 where is present a layer of DLC. Glycerol is the polyol which gives among the best results and it is a common product and easy implementation. On the other hand, it will be seen from reading example 17 that the use of ethylene glycol (C ₂ ) is not satisfactory.

We will also refer to the appended single figure that allows us to assess the results obtained over time and shows that they are stable, even after many cycles.

Description for the following Contracting State (s): DE, FR, GB

The present invention relates to a watch, in particular to a mechanical watch, of which at least some of the moving parts are lubricated by agents with a very low coefficient of friction.

It is known that one of the major problems that arises in watchmaking, particularly in the field of the chronometer wristwatch, is to ensure as low a friction as possible between the moving parts relative to each other, account given the low energy reserve available.

Usually, the lubrication is ensured between the parts in relative motion, generally steel and ruby, by oils well known in the technical field considered, which produce low coefficients of friction, for example <0.1 at the temperature of 23 ° C. In this respect, mention may be made of the oil known under the name of oil 941, in addition to other lubricants which may also be used, in particular synthetic polyalphaolefin (PAO) type oil mixtures comprising as additives glycerol monooleate ( GMO).

As described elsewhere by Kano et al, Tribology Letters 18 (2) February 2005 it has proved possible to obtain even better friction coefficients, typically ≤ 0.06, preferably ≤ 0.05, at the temperature of 80 ° C., by inserting a film of carbon between the friction surfaces, that is to say by combining the deposition of a hard carbon film on at least one of the sliding surfaces with the use of an additive -OH group such as GMO in the lubricant. In this paper, it is question of sliding of surfaces containing -OH groups and the authors make the hypothesis, that they indicate immediately as being to verify by analytical works, that the -OH groups slide against each other by being hooked on the surface via the film containing groups C.

However, it was quickly noticed that the interposition of a film containing carbon, if it gave excellent results for the friction of parts working at high temperature, for example at 80 ° C, in particular in automobile engines, did not suit however for parts working at low temperature as in watchmaking. The lubrication obtained shows no progress compared with traditional lubrication.

US 2,355,616 describes a watch of which some moving parts are lubricated by an alcohol or polyol.

Surprisingly, it was found that much better results could be achieved by removing the intermediate carbon layer, and by directly associating one or more oxide surfaces having an affinity for the hydrophilic groups and a compound containing one or more several hydrophilic groups. This is precisely the subject of the invention, which therefore concerns a watch, in particular a mechanical watch, of which at least some of the moving parts are lubricated by agents with a very low coefficient of friction. We will discuss here and in the following the statement of "very low coefficient of friction" for values of this coefficient less than or equal to 0.06.

• la montre comprend une couche épilame intercalaire entre les deux pièces ou
• le composé est choisi parmi le propylène glycol, le diéthylène glycol, le 1,6-hexanediol, le 1,2,6-hexanetriol, le triéthylène glycol, le diglycérol, le triglycérol et la triethanolamine.

Such a watch includes a first relatively sliding piece on a second piece, the first piece being formed of oxide or having an oxide layer on the surface, the sliding surface having a chemical affinity with hydrophilic groups, as well as, on the sliding surface of the first part, at least one compound containing one or more hydrophilic groups chosen from C ₃ -C ₉ polyols having at least one-third of -OH groups relative to the number of carbon atoms, said watch characterized in that

• the watch includes an epilame layer between the two pieces or
• the compound is chosen from propylene glycol, diethylene glycol, 1,6-hexanediol, 1,2,6-hexanetriol, triethylene glycol, diglycerol, triglycerol and triethanolamine.

This compound may be a mixture and may contain, for example, another substance containing hydrophilic groups, such as water.

The C ₃ -C ₉ polyol may be chosen for example from the group comprising glycerol (C ₃ H ₈ O ₃ ), propylene glycol (C ₃ H ₈ O ₂ ), diethylene glycol (C ₄ H ₁₀ O ₃ ), 1,6-hexanediol (C ₆ H ₁₄ O ₂ ), 1,2,6-hexanetriol (C ₆ H ₁₄ O ₃ ), triethylene glycol (C ₆ H ₁₄ O ₄ ), diglycerol (C ₆ H ₁₄ O ₅ ), triglycerol (C ₉ H ₂₀ O ₇ ), triethanolamine (C ₆ H ₁₅ NO ₃ ). As can be seen, the carbon chain of the polyol may comprise O or N.

Glycerol is a C ₃ alcohol containing 3 -OH groups, propylene glycol a C ₃ alcohol containing 2 -OH groups, diethylene glycol a C ₄ alcohol comprising 2 -OH groups and 1 O atom in the chain, 1,6-hexanediol a C ₆ alcohol comprising 2 -OH groups, 1,2,6-hexanetriol a C ₆ alcohol comprising 3 -OH groups, triethylene glycol a C ₆ alcohol comprising 2 -OH groups and two O atoms in the chain, the diglycerol a C ₆ alcohol comprising 4 -OH groups and 1 O atom in the chain, the triglycerol a C ₉ alcohol comprising 5 -OH groups and 2 O atoms in the chain and triethanolamine a C ₆ alcohol comprising 3 -OH groups and an N atom.

The second surface may also have a chemical affinity with hydrophilic groups and be, for example formed of oxide or have on the surface an oxide layer, as well as the first surface. It can also be metallic or metal alloy.

Thus, one of the relative sliding parts may be ceramic, in particular alumina or zirconia, more particularly ruby or sapphire, and the other relatively sliding parts may be made of iron, steel, for example steel 20AP , or other alloy of iron, or of brass, aluminum, titanium, cuproberyllium, silicon, nickel, nickel-phosphorus or their alloys. The part in question may be a part having a surface coating, obtained for example by galvanic deposition of gold, gold-copper-cadmium and gold, nickel, rhodium, tin-nickel. It may also have an anodized surface, as in the case of aluminum alloy parts or titanium. It can also be modified by a surface treatment such as oxidation, carburization or nitriding. Between the two relatively sliding parts may also be an intermediate layer called "epilame", well known in the watch industry and used to prevent the spreading of lubricants.

It is thus possible to achieve excellent sliding between a pallet of ruby or zirconia anchor and a steel escapement wheel, or alternatively between a steel shaft and a ruby or zirconia bearing.

Preferably, the compound comprising one or more hydrophilic groups is a low molecular weight polyol, for example glycerol or aqueous glycerol. This compound acts as a lubricant forming a film or film between the two moving surfaces.

The exceptional slip properties obtained by the interaction between hydrophilic groups and oxygen groups by means of hydrogen bonds are explained. It is also possible that the forces of Van der Waals also intervene in the phenomenon.

The invention will be better understood with reference to Examples 6 and 8 to 16 which follow, given in a non-limiting manner, and to the single appended figure. These examples, for better readability, are included in the form of a single table which is completed by a comparative example 17 relating to ethylene glycol and a series of comparative examples 18 to 24, 1 to 5 and 7 .

Examples 1 to 6 indicate the results obtained with aqueous glycerol on various pairs of surfaces, while Examples 7 to 17 give the results obtained with compounds other than glycerol for the same pair of 20AP steel-ruby surfaces.

These results were obtained on an alternative rectilinear tribometer, using a pion and a disk for a normal force of 1.5 N corresponding to a Hertz pressure of 0.8 GPa, and a speed of 61.2 mm / s, for ten thousand cycles (ie a total stroke of 200 m) at least. Each value is an average of at least 3 trials. The temperature is typically 23 ° C and the relative humidity is typically 35%. The quantity of lubricant deposited is 1 μl. By cycle is meant a round-to-back rubbing of one piece against the other.

The coefficient of friction, a standard measure in watchmaking, expresses the dynamic friction and corresponds to the ratio between the tangential force exerted to maintain the relative movement between the two parts and the perpendicular force exerted on them.

20AP steel is a hardening carbon steel made of 1% carbon, 0.4% manganese, 0.2% lead, 0.15% silicon, 0.05% sulfur, and iron for the balance. The term "epilamed 20AP steel" is intended to denote a 20AP steel on which a conventional epilame has been deposited, in this case that sold under the trademark Fixodrop FK / BS-10 by Moebius et Fils in Allschwil (Switzerland).

Ruby is a synthetic ruby as commonly used in watchmaking and "85% glycerol" means a liquid composed of glycerol at 85% by weight and 15% by weight of water (mutatis mutandis for Examples 13, 14 and 16). ).

"941 Oil" is a commercial oil manufactured by the same Moebius Company and is a mixture of one alkyl-aryl monooleate and two C ₁₀ -C ₁₃ diesters with anti-wear and extreme pressure additives; its viscosity measured at 20 ° C is 100 mm ² / s.

"PAO + GMO" is a blend of polyalphaolefin synthetic oils (PAO) with a viscosity measured at 20 ° C of 100 mm ² / s, and 1% of GMO additive (glycerol monooleate).

Finally "DLC", for "diamond like carbon", denotes a layer of very hard diamond-like carbon deposited in the vapor phase, with reference to the Kano article cited above. Board Lubricant Material of the pawn Material of the disc Coef. friction 1 Glycerol 85% 20AP steel Ruby 0.02 2 Glycerol 85% Ruby 20AP steel 0.02 3 Glycerol 85% Ruby Ruby 0.03 4 Glycerol 85% Ruby Yes 0.06 5 Glycerol 85% Ruby Neither electroformed 0.04 6 Glycerol 85% Ruby Epilamated 20AP steel <0.02 7 100% glycerol Ruby 20AP steel <0.02 8 1,2,6-hexanetriol Ruby 20AP steel 0.05 9 Propylene glycol Ruby 20AP steel 0.05 10 triethanolamine Ruby 20AP steel 0.05 11 Triethylene glycol Ruby 20AP steel 0.05 12 α-α'-Diglycerol Ruby 20AP steel 0.06 13 Triglycerol 68% Ruby 20AP steel 0.06 14 1,6-hexanediol 86% Ruby 20AP steel 0.06 15 Diethylene glycol Ruby 20AP steel 0.06 16 1,6-hexanediol 67.5% Ruby 20AP steel 0.06 17 Ethylene glycol Ruby 20AP steel 0.10 18 dried up 20AP steel Ruby 0.64 19 dried up 20AP + DLC steel Ruby 0.17 20 dried up 20AP + DLC steel Ruby + DLC 0.09 21 941 oil 20AP steel Ruby 0.08 22 941 oil 20AP + DLC steel Ruby 0.09 23 PAO + GMO 20AP steel Ruby 0.08 24 PAO + GMO 20AP + DLC steel Ruby 0.08

On reading the table, we can only see the excellent results obtained and the lowering of the coefficient of friction values compared to the solutions of comparative examples 18 to 24 serving as reference values, the "dry" examples corresponding to the sliding Direct piece against piece, except the example 20 where is present a layer of DLC. Glycerol is the polyol which gives among the best results and it is a common product and easy implementation. On the other hand, it will be seen from reading example 17 that the use of ethylene glycol (C ₂ ) is not satisfactory.

We will also refer to the appended single figure that allows us to assess the results obtained over time and shows that they are stable, even after many cycles.

Claims (12)

1. Watch, at least some of the moving parts of which are lubricated by agents having a very low friction coefficient, characterized in that it comprises:

   a first part that can slide relative to a second part, and an interlayer epilame layer between the two parts, the first part being formed of oxide or having an oxide layer at the surface, the sliding surface having a chemical affinity with hydrophilic groups,

   and also, on the sliding surface of the first part, at least one compound containing one or more hydrophilic groups chosen from C₃-C₉ polyols having at least a third of -OH groups relative to the number of carbon atoms.
2. Watch according to Claim 1, characterized in that the second part is, itself also, formed of oxide or has an oxide layer at the surface, the sliding surface having, itself also, a chemical affinity with hydrophilic groups.
3. Watch according to Claim 1, characterized in that the second part is metallic or made of metal alloy.
4. Watch according to Claims 1 to 3, characterized in that the C₃-C₉ polyol is chosen from the group comprising glycerol, propylene glycol, diethylene glycol, 1,6-hexanediol, 1,2,6-hexanetriol, triethylene glycol, diglycerol, triglycerol, triethanolamine.
5. Watch according to Claim 1 or 4, characterized in that the polyol contains water.
6. Watch according to Claim 5, characterized in that the polyol is glycerol or aqueous glycerol.
7. Watch according to one of Claims 1 to 6, characterized in that at least one of the parts contains aluminium oxide or zirconium oxide.
8. Watch according to Claim 7, characterized in that one of the parts is made of ruby or made of zirconia.
9. Watch according to one of Claims 1 to 6, characterized in that the other part is made of iron, steel, brass, aluminium, titanium, beryllium-copper, silicon, nickel, nickel-phosphorus or alloys thereof, with or without a galvanic surface coating, with or without an anodic, oxidizing, carburizing or nitriding surface treatment.
10. Watch according to one of Claims 1, 8 and 9, characterized in that the part made of ruby or made of zirconia is a pallet stone and the part made of steel is an escape wheel.
11. Watch according to one of Claims 1, 8 and 9, characterized in that the part made of ruby or made of zirconia is a bearing and the part made of steel is a shaft.
12. Watch, at least some of the moving parts of which are lubricated by agents having a very low friction coefficient, characterized in that it comprises:

    a first part that can slide relative to a second part, the first part being formed of oxide or having an oxide layer at the surface, the sliding surface having a chemical affinity with hydrophilic groups,

    and also, on the sliding surface of the first part, at least one compound containing one or more hydrophilic groups chosen from C₃-C₉ polyols having at least a third of -OH groups relative to the number of carbon atoms, this compound being chosen from propylene glycol, diethylene glycol, 1,6-hexanediol, 1,2,6-hexanetriol, triethylene glycol, diglycerol, triglycerol, triethanolamine.

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