CH708539B1

CH708539B1 - Agent for the surface lubrication of an object.

Info

Publication number: CH708539B1
Application number: CH00030/15A
Authority: CH
Inventors: Richard David; Letondor Christophe
Original assignee: Swatch Group Res & Dev Ltd
Priority date: 2012-07-10
Filing date: 2013-06-04
Publication date: 2017-03-31
Also published as: JP2015523442A; DE212013000152U1; HK1206775A1; CN104603247A; JP3210292U; WO2014009059A1

Abstract

The present invention relates to an agent, in particular for surface lubrication of an article comprising one or more molecules having the general formula (1): wherein: A is an anchoring group comprising a moiety selected from the group consisting of: From the group consisting of silane groups, hydroxyl groups, pyrocatechol groups, phosphate groups, phosphonate groups, carboxylic acid groups, amine groups, thiol groups and any combination of two or more of the abovementioned groups, and F is a functionalizing group , Wherein the functionalizing group comprises a branched polymer having a main chain and at least two side groups, at least one of the side groups being a C1-20 hydrocarbyl group or a fully halogenated C1-20 hydrocarbon group.The invention relates to the technical field of tribology for the mechanical parts of time-measuring devices.

Description

FIELD OF THE INVENTION The present invention relates to an agent, in particular for surface modification of an object, such as, for example, for the modification of the tribological surface properties of an object. In addition, the present invention relates to the use of such an agent, to an article having a surface coated with such an agent, to a method of producing such an article, and to the use of such an article.

BACKGROUND OF THE INVENTION Conventional lubrication in watch movements uses lubricants which are viscous enough to avoid the wear of surfaces by the separation of their respective surface irregularities. However, high-viscosity lubricants also mean high shear rates and energy loss. This results in "high" friction coefficients of about 0.1-0.15. Consequently, a compromise must be found. Moreover, whatever the viscosity of the lubricants is, at low speeds and / or high loads, the separation of the surfaces is interrupted, whereby contacts occur between the surface unevenness. In this case, the friction coefficient increases drastically (0.15-0.3), and wear occurs.

SUMMARY OF THE INVENTION [0003] Accordingly, the object of the present invention is the result of the distinction between lubricants and substrates which are not considered to belong to a unique tribological system.

[0004] The use of a sufficient surface functionalization can lead to better coupling between the substrates and the lubricants in order to increase the tribological performance of such a system.

[0005] Accordingly, the invention aims to provide an improved agent which is suitable for surface lubrication of an article, that is, for modifying the tribological surface characteristics of an article, the means for forming a coating layer having improved uniformity of the molecules of the Providing a coating layer having an improved density of the molecules of the composition and / or forming a coating layer having a higher thickness and / or forming a coating layer with improved aesthetic properties and / or for forming a coating layer with a coating layer having a higher thickness Improved degree of lubrication.

According to the present invention, this object is achieved by providing an agent comprising one or more molecules having the general formula (1): wherein: A is an anchoring group comprising a moiety selected from the group consisting of: Which comprises silane groups, hydroxyl groups, pyrocatechol groups, phosphate groups, phosphonate groups, carboxylic acid groups, amine groups, thiol groups, and any combination of two or more of the above-mentioned groups, And F is a functionalizing group, the functionalizing group comprising a branched polymer having a main chain and at least two side groups, at least one of the side groups being a C1-20 hydrocarbyl group or a fully halogenated C1-20 hydrocarbon group.

[0007] This solution is based on the surprising discovery that such an agent can be attached firmly and uniformly with a high molecular weight on the surface of the object, owing to its anchoring groups and the branched polymer group. Accordingly, this agent has a high mechanical scratch resistance and a high cleaning resistance.

[0008] Moreover, the agent according to the present invention can be easily optimized in terms of its properties such as adherence to the surface material because the anchoring group can be selected for this purpose irrespective of the kind of the functionalizing group.

[0009] Apart from this, due to the binding of the agent to the surface of the article, the modified surface of the article provides excellent resistance to cleaning. In addition, a layer of such an agent exhibits excellent aesthetic properties on a surface. Finally, such a means can be easily optimized to allow a lubricant to enter into it and swell it to increase the lubricating performance of the surface of the article.

[0010] Without wishing to be bound by any theory, the above-mentioned excellent surface properties may result in an improved packing of the molecules of the agent according to the present invention on the surface of the article and an increased density of the carbon atoms, Functionalizing group comprising a branched polymer is achieved. In fact, the packing of the molecules can be accurately controlled and, incidentally, the thickness of the branched polymers can be reliably generated. In addition, the branched polymers allow the use of multi-monomers with localized functionalization, ie, by selective UV exposure, the polymerisation can only take place at a specific point.

[0011] Since the anchoring group can be selected from a wide variety of functional groups, the anchoring group of the AF molecules can be chosen to optimize their adhesion to a particular surface material.

[0012] Therefore, the agent according to the present invention can be applied to various different surface materials by suitably selecting the anchoring group. In addition to the above-mentioned adaptation of the agent to a specific substrate, the agent can be provided easily and efficiently directly or indirectly on the surface to be modified. For this purpose, a polymerization process is suitable in which an anchor group A, which is more suitable for the selected material.

Accordingly, the anchoring group A can be bound to the surface, whereafter the functionalizing group is synthesized via a graft polymerization of the monomers on the anchoring group to form the AF of the agent, or the functionalizing group is prepared by graft polymerization of the monomers on the Anchor group A, whereafter the anchor group A is bonded to the surface to form the AF of the agent according to alternative embodiments of the present invention.

[0014] Advantageously, the agent according to the present invention may include a solvent to swell the agent to thereby form a modified surface of the article which, as compared with a respective surface to which a respective lubricant is added without the agent according to the invention The present invention has a particular and surprisingly low coefficient of friction. This advantage is based on the controlled density of the side groups. In fact, the branched polymers bring side groups having a high density and a heterogeneous distribution (the side groups possess different directions) in a certain volume.

[0015] The kind of the hydrocarbon group used in the present invention is not particularly limited but includes unsubstituted hydrocarbon groups as well as any kind of a substituted hydrocarbon group. Accordingly, the term hydrocarbon group is not limited to groups consisting only of carbon and hydrogen atoms, but also extends to groups which also contain other substituents such as a halogen substituent or an ester group.

[0016] A catechol group according to the present invention comprises a 1,2-dihydroxybenzene group and any substituted 1,2-dihydroxybenzene group, such as a dopamine group or a nitrodopamine group.

[0017] According to the present invention, the term "anchoring group comprising an amine group" also encompasses polyamine-derived anchoring groups. Thus, in the present invention, such an anchoring group may contain a structural unit derived from a polyamine, ie, a compound containing more than one terminal amino group and optionally containing one or more secondary and / or tertiary amino groups.

[0018] As set forth above, the functionalizing group F comprises the branched polymer. The functionalizing group F preferably consists of the branched polymer, ie, it contains no further group in addition to the branched polymer.

Particularly good lubrication results are obtained in particular when the at least one of the side groups is a C2-18 hydrocarbon group, preferably a C4-17 hydrocarbon group, more preferably a C6-16 hydrocarbon group, and most preferably a C8-l4 Hydrocarbyl group.

According to a further embodiment of the present invention, it is preferred that at least 50%, preferably at least 80%, more preferably at least 90% and most preferably all the side groups are a hydrocarbyl group, the hydrocarbyl groups preferably being C1-20 hydrocarbon groups, especially Preferably C2-18 hydrocarbon groups, more preferably C4-17 hydrocarbyl groups, more preferably C6-16 hydrocarbon groups, and most preferably C8-14 hydrocarbon groups.

Depending on the desired properties of the composition, the at least one side group may be an unsubstituted hydrocarbon group, ie, a hydrocarbon group exclusively comprising CH bonds, or a substituted hydrocarbyl group. In principle, any substituted hydrocarbyl groups can be used, and particularly good results are obtained when the substituted hydrocarbyl group is an alkyl ester group and preferably an unsubstituted alkyl ester group. The agents having such groups are particularly suitable for improving the lubricating properties of the surface of the article.

According to a further preferred embodiment of the present invention, the hydrocarbyl group is selected from the group consisting of alkyl groups, alkenyl groups, alkynyl groups, aryl groups, alkylaryl groups, arylalkyl groups, alkenylaryl groups, arylalkenyl groups, Arylalkyl ester groups, alkynylaryl groups, arylalkynyl groups, alkyl ester groups, alkenyl ester groups, alkynyl ester groups, aryl ester groups, alkylaryl ester groups, arylalkyl ester groups, alkenylaryl ester groups, arylalkenyl ester groups, alkynylaryl ester groups, arylalkynyl ester groups, and the like Any combination of two or more of the aforementioned groups. All alkyl groups, alkenyl groups and alkynyl groups can be linear, branched or cyclic.

[0023] Preferably, the hydrocarbyl group is an alkyl ester group and more preferably a linear alkyl ester group.

Non-limiting examples of alkyl ester groups are hydrocarbon groups selected from the group consisting of acrylate esters, methacrylate esters, styrene derivatives having at least one alkyl group attached to the aromatic ring, and any combination of two or more of the foregoing Mentioned groups.

As an alternative to the abovementioned alkyl ester group, it may be preferred for a particular application that the hydrocarbyl group is an arylalkyl or an alkylaryl group, and more preferably a linear arylalkyl or a linear alkylaryl group.

[0026] In particular, the agent according to the present patent application, which improves the lubricating properties of a surface of an article, is particularly preferred that the branched polymer has a certain extent, namely, 50 to 500, preferably 100 to 450, more preferably 150 To 400, more preferably 200 to 350, and most preferably 220 to 300, pages groups.

[0027] In this embodiment, all side groups are the same or different and preferably C6-20 hydrocarbon groups, more preferably C8-18 hydrocarbon groups, more preferably C10-16 hydrocarbon groups, and most preferably C11-14 hydrocarbyl groups ,

[0028] All of the abovementioned hydrocarbon groups are preferably unsubstituted hydrocarbon groups or alkyl ester groups.

In particular, the agent according to the present patent application, which improves the lubricating properties of a surface of an article, is particularly preferred in that the branched polymer has a certain volume, namely that it has a dry thickness of 50 to 2000 nm, and more preferably between 200 and 1000 nm of the polymer brushes to improve the wear resistance.

[0030] All known lubricants can be used as a lubricant which is absorbed, for example, by swelling into the composition. Non-limiting examples are therefore ionic liquids, mineral oils, vegetable oils, animal oils, synthetic oils, fats, waxes, polyol esters, neutral oils, vaseline or the like.

[0031] In order to provide a sufficiently thick layer to provide the desired properties of the modified surface, the agent according to the present invention preferably has a certain length. Accordingly, it is preferable that the length of the main chain of the agent is in a range of from 10 to 300 nm, more preferably from 50 to 250 nm, more preferably from 100 to 200 nm, and most preferably from 120 to 180 nm.

According to a further particularly preferred embodiment of the present invention, at least one of the side groups of the branched polymer of the functionalizing group F has at least one functional group which is capable of crosslinking with a further molecule of the composition having the general formula (1). Such crosslinking improves the wear resistance of the branched polymer and is thus particularly preferred. When multiple crosslinking groups are present in the branched polymer, these crosslinking groups may be randomly distributed throughout the molecule or may be distributed in blocks.

In order to achieve a sufficient crosslinking density, it is preferred that the branched polymer comprises at least one block which comprises at least 5 and more preferably at least 10 side groups, at least two of these side groups each comprising at least one functional group which is capable of crosslinking with a Further molecule of the agent having the general formula (1).

Alternatively and even more preferably, the branched polymer contains at least one further block which comprises at least 5, preferably at least 10, side groups, all side groups of this at least one further block containing no functional groups which are capable of crosslinking with another molecule of the branched

Polymer.

[0035] Alternatively and even more preferably, the branched polymer contains two of the further blocks, each of which comprises at least 5 and preferably at least 10 side groups, all side groups of these further blocks not containing functional groups capable of crosslinking with another molecule of the branched polymer Wherein the block comprising at least 5 and preferably at least 10 side groups, at least two of these side groups each comprising at least one functional group capable of crosslinking with another molecule of the agent having the general formula (1) , Is arranged between the two further blocks.

[0036] Another object of the present invention is an article comprising a substrate having at least one surface, at least one of the at least one surface being coated with the above-mentioned agent.

In order to effect a firm adherence of the agent to the surface, at least one of the anchoring groups of the molecules of the agent having the general formula (1) is bonded to the surface of the substrate. Even if physical bonding or bonding via ionic groups is possible, it is preferred that at least one of the anchoring groups of the molecules of the agent having the general formula (1) is covalently bonded to the surface of the substrate.

[0038] In principle, the agent according to the present invention can be bound to any substrate. Non-limiting examples of suitable substrate materials are those selected from the group consisting of silicon, diamond-like carbon, silicon carbide, sapphire, steel, metallized steel, nickel-plated steel, ruby, alumina, iron oxide, magnesium alloy, silica, niobium oxide, A polymer, and any combination of two or more of the foregoing materials.

[0039] Of course, the type of anchoring group determines the adhesion of the agent according to the present invention to the specific substrate so that the anchoring group must be chosen depending on the substrate material. Good results for the substrates consisting of silicon, silicon carbide, sapphire and diamond-like carbon are obtained, for example, with an anchoring group containing a silane group, a suitable example of an anchoring group for substrates consisting of steels, metals, ruby , Alumina, and iron oxide is a nitrodopamine group. In addition, phosphate groups and phosphonate groups are suitable anchoring groups, in particular for substrates which consist of magnesium alloys, carboxylic acid groups being suitable anchor groups, in particular for substrates,

[0040] The present invention further provides a method for producing the above-mentioned object, comprising the steps of: (a) providing a substrate having at least one surface, (b) bonding at least one anchoring group selected from the group consisting of: Silane groups, hydroxyl groups, pyrocatechol groups, phosphate groups, phosphonate groups, carboxylic acid groups, amine groups, thiol groups and any combination of two or more of the abovementioned groups, to at least one of the at least one A surface of the substrate, (c) providing at least one type of monomer and (d) graft polymerizing the at least one type of monomer onto the at least one anchoring moiety to form a branched polymer covalently bonded to the at least one anchoring moiety.(E) sources of said at least one branched polymer by trapping a solvent.

According to a first alternative, the method according to the invention for producing the above-mentioned object comprises the following steps: (c ') providing at least one type of monomer, (d') graft polymerizing the at least one type of monomer onto the at least one anchoring group Selected from the group consisting of silane groups, hydroxyl groups, catechol groups, phosphate groups, phosphonate groups, carboxylic acid groups, amine groups, thiol groups and any combination of two or more of the abovementioned Groups to form a branched polymer covalently bonded to the at least one anchoring group, (a) providing a substrate having at least one surface and (b ') Binding the at least one anchoring group to at least one of the at least one surface of the substrate, (e) swelling the solvent of the at least one branched polymer.

According to a second alternative, the method according to the invention for producing the above-mentioned object comprises the following steps: (cT) graft polymerizing the at least one type of monomer to form at least one branched polymer, (a) providing a substrate with at least one (B) bonding at least one anchoring group selected from the group consisting of silane groups, hydroxyl groups, pyrocatechol groups, phosphate groups, phosphonate groups, carboxylic acid groups, amine groups, thiol groups, and each Combination of two or more of the above-mentioned groups on at least one of the at least one surface of the substrate, (f) bonding the at least one anchoring group to the at least one branched polymer.(E) sources of said at least one branched polymer by trapping a solvent.

[0043] The branched polymer can also be prepared with a surface-initiated oxygen-tolerant ARGET ATRP synthesis.

ARGET ATRP polymerization reactions were carried out depending on the type of substrate using only CuBr2 and never on Fe-based salts. In order to obtain a well-defined (limited) amount of air in contact with the solution before any liquid reagents are added, the initiator-functionalized wafer is placed in a reaction flask (20 ml Schlenkrohr, kleiner 5 ml-Rundkolben or 20 ml-Vail With a flat bottom), which is then sealed with a rubber septum.

The solid reagents, CuBr2 (5 mg, 0.022 mmol) and 4,4'-dinonyl-2,2'-bipyridine (44 mg, 0.11 mmol) were added to a 100 ml flask equipped with To a dowel. Thereafter, the air was removed by the application of three cycles of vacuum and nitrogen filling - this was done to gain control over the ratio of oxygen and reducing agent present in the system. The vacuum is pumped for at least 2 minutes each. Further, 19 ml of an inhibitor-free monomer (dodecyl methacrylate) was added to a tightly sealed flask (simply by syringe from the monomer bottle) and vigorously stirred at 110 ° C for at least 5 minutes until the mixture appears bright violet and the ligand is completely dissolved.

The reducing agent / solvent solution is then injected into the hot mixture of monomer, CuBr2 and ligands, and at this moment the complete reaction mixture is obtained. After a maximum of 5 minutes of vigorous stirring at 110 ° C., the desired volume of the pale yellow-brown liquid solution is then transferred into the closed reaction flask, which contains the initiator-functionalized wafers.

There are two variants of how the reaction has been performed: with flasks containing the substrate and filled with air (more simple) or filled with nitrogen (which requires atmospheric exchange due to vacuum nitrogen cycles). When the reaction piston is not connected to the Schlenk line, an empty balloon is connected to the piston, which can expand and accommodate an additional gas volume without allowing additional air into the piston.

[0048] All fluid transfer is preferably carried out with oxygenated syringes (only removed from the package). In addition, preferably, when the reaction is carried out in reaction flasks connected to the Schlenk line, the wafers pass through the vacuum nitrogen cycles to provide an inert atmosphere during the further reaction. In this case, no empty balloon is needed to take an overpressure.

When working with flat-bottomed reaction glasses, a better homogeneity of the coating is achieved when the wafers are placed upside down, ie, with the functionalized area pointing to the bottom of the reaction glass.

[0050] In principle, the graft polymerization can be carried out by any technique known to one skilled in the art. However, particularly good results are obtained when the graft polymerization is carried out as an atom transfer radical polymerization.

Due to its advantageous properties described above, the agent according to the present invention can be used in mechanical engineering, preferably in precision mechanics, and most preferably in the watchmaking and / or watchmaking sector.

For this reason, the object according to the present invention can also be used in mechanical engineering, preferably in precision mechanics and most preferably in watchmaking.

[0053] The present invention is described in more detail below with reference to examples which are intended to illustrate but not limit the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS [0054] Further features and advantages of the present invention will become more apparent upon reading the following detailed description made with reference to the accompanying drawings, which are not intended to be limiting, and wherein:

FIG. 1 is a schematic representation of a lubrication supported by polymer brushes; FIG.

Figures 2-3 are graphs showing the positive influence of the source configuration compared to the untreated surface for an ester type lubricant;

Figures 4-7 are graphs showing the positive influence of the source configuration compared to the untreated surface with respect to various alkane type lubricants;

Figures 8-9 are graphs showing the positive influence of the source configuration compared to the untreated surface with respect to a conventional lubricant of watchmaking.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Dimethylchlorosilane (Aldrich Fine Chemicals, 98%), 10-undecen-1-ol, (Aldrich Fine Chemicals, 98%), 2-bromo-2-methylpropionyl bromide (Acros Organics, 98%) Chloroplatinic acid hexahydrate (ABCR Germany 99.9%) used for the initiator synthesis were used as obtained from the suppliers.

150 ml of each of the monomers n-hexylmethacrylate (Aldrich fine chemicals, 98%), laurylmethacrylate (Acros Organics, 96%) and stearylmethacrylate (TCI Deutschland GmbH,> 95%) was obtained from the paramethoxyphenol inhibitor by passing through an alumina column (Aluminum oxide B, column diameter 25 mm, height ca. 15 cm, eluent: pentane, gravity). After removal of the eluant in vacuo, the resulting purified monomers were stored in a tightly closed vail under inert gas at -20 ° C. and were usually used for synthesis within less than 2 weeks after the above-mentioned purification.

4,4'-dinonyl-2,2'-bipyridine (dNbpy, Aldrich fine chemicals, 97%), anisole (Acros Organics, 99%) and copper (II) bromide (Sigma Aldrich, 99%) were used As they were obtained. Copper (I) bromide (Aldrich Fine Chemicals, 5N) was purified by washing in glacial acetic acid. Therefore, 4 g of CuBr was suspended in 400 ml of acetic acid, the resulting mixture was stirred overnight at room temperature. The CuBr was then separated by filtration using filter paper, then washed with methanol and diethyl ether and dried under vacuum. The CuBr thus obtained was stored under inert gas at room temperature.

The synthesis of the 11- (2-bromo-2-methyl-propionyl) -dimethylchlorosilane initiator (BPCS) having a dimethylchlorosilane anchoring group was carried out according to a method described by Sanjuan (Lang-muir 2007, 23, 5769-5778, Sanjuan et al.).

9 ml (60 mmol) of triethylamine (Sigma Aldrich, 99.5%) were added to 10.7 ml of the 10-undecen-1-ol in 50 ml of dry tetrahydrofuran (Sigma Aldrich, 99%), followed by a reaction Dropwise addition of a solution of 7 ml of 2-bromo-2-methylpropionyl bromide in 20 ml of dry tetrahydrofuran. The mixture was stirred under inert gas for 24 hours and diluted twice with 100 ml of hexane, washed twice with 100 ml of 2M HCl (prepared by adding 42 ml of 37% HCl to 208 ml of H 2 O) twice with 100 ml of ultrapure water 4 times , The organic phase was separated and dried over magnesium sulfate for 60 minutes before filtering using a filter paper and concentrating at 130 ° C at 40 ° C. The crude product obtained was purified by passing through a silica column (silica gel 60, diameter 80 mm, Height about 27 cm, eluent: 1.5 l dichloromethane, gravity). After removal of the eluant in vacuo, 10-undecen-1-yl-2-bromo-2-methylpropionate was obtained as a colorless oily product which was stored under inert gas at 4 ° C until the second step described in the following.

In the second reaction step, 2.54 g of the 10-undecenyl-1-yl-2-bromo-2-methylpropionate obtained in the preceding step were added to 10 mg of chloroplatinic acid hexahydrate and 7.93 ml of dimethylchlorosilane. The resulting mixture was stirred overnight in the dark under inert gas and filtered through silica grafting without the use of an additional solvent. The excess of unreacted silane was removed by drying under vacuum for 24 hours.

The 11- (2-bromo-2-methyl-propionyl) dimethylchlorosilane initiator (BPCS) obtained was stored at -20 ° C. at -20 ° C. in a container filled with an inert gas and sealed with a parafilm.

Example 1 (i) Binding the Initiator to a Silicon Surface The silicon articles (P / B <100> Si-Mat Wafers, Germany) were washed 3 times with isopropanol in the ultrasonic treatment bath and incubated for 30 minutes in a UV Ozone cleaner (UV / Ozone ProCleaner ™ and ProCleaner ™ Plus, IA, USA). The thus obtained purified articles were immediately immersed in a 10 mM solution of the BPCS initiator in freshly distilled toluene and incubated under an inert atmosphere for 24 hours. This was followed by washing five times in toluene by immersion in five different toluene baths for a few minutes, and immersing in the last of the five baths a short ultrasonic treatment for 20 seconds to remove weakly bound molecules and final rinsing With isopropanol.

The BPCS initiator functionalized silicon surface obtained according to the previous protocol was characterized by a measurement of the static contact angle (CA). This measurement was carried out on a BPCS layer adsorbed to a UWO -conducted ultrahydrophilic silicon surface, the UWO-purified ultrahydrophilic silicon surface, before immersed in the solution of the BPCS initiator, had an initial contact angle of less than 3 ° A contact angle of 77 ° ± 2 ° resulted.

The thickness of the BPCS layer was determined as 1.8 ± 0.1 nm using a variable angle (VASE) spectroscopic ellipsometer (M-2000F, LOT Oriel GmbH, Darmstadt, Germany). The ellipsometric measurement data were collected at three different angles of incidence 65 °, 70 ° and 75 °, the incident wavelength being varied between 995 and 370 nm. The resulting thickness values are a result of an adaptation to a three-layer model Si-Jellium / Si02 / Cauchy, which is defined in the WVASE32 software (LOT Oriel GmbH, Darmstadt, Germany). (Ii) Graft-Atomic-Transfer Radical Polymerization of Lauryl Methacrylate [0065] The polymerization reactions were carried out in an oxygen-free Schlenk line under inert gas. Under ambient conditions, 19 ml (16.5 g) of lauryl methacrylate, 2, 1 ml of anisole and 280 mg of dNbpy were added to a flask sealed with a rubber septum. After stirring and dissolving the ligand, the resulting solution was subjected to four freeze-pump-thaw cycles before being transferred to a second flask containing 62 mg of copper (I) bromide and 15 mg of copper (II) bromide under an inert atmosphere Was transferred. The resulting solution was stirred for 5 minutes while heating with a hot oil bath at a temperature of 110 ° C. to obtain a dark brown homogeneous mixture. Four ml of this mixture was transferred to the sample prepared in step (i) of the BP-CS modified silicon article placed in a 20 ml Schlenk tube under an inert atmosphere using an oxygen-free syringe. The reaction was held at 110 ° C for 3 hours under an inert atmosphere. The reaction was quenched by the action of air atmosphere and the addition of toluene to give the resulting article, ie, a silicon substrate on the surface of which a silane portion was attached to the polymer resulting from the above reaction, which was separated from the mixture , (Iii) Purification The article obtained in the preceding step (ii) was subjected to a purification to remove the unbound material. Purification may be carried out by immersing the resulting article in dichloromethane for 15 minutes under ultrasound treatment, all done three times before the article was dried.

The thickness of the surface-bonded polymer coating was determined using a spectroscopic ellipsometer with variable angle (VASE) (M-2000F, LOT Oriel GmbH, Darmstadt, Germany) between 200 and 350 nm.

Example 2 The procedure of Example 1 was followed except that in step (ii), 19 ml (16.8 g) of n-hexyl methacrylate, 2.1 ml of anisole, 425 mg of dNbpy, 94 mg of copper (I) Bromide and 23 mg of copper (II) bromide.

The thickness of the surface-bound polymer coating was determined as between 50 and 150 nm according to the method of Example 1.

EXAMPLE 3 The procedure of Example 1 was followed except that in step (ii), 18.9 ml (16.3 g) of stearyl methacrylate, 4.7 ml of anisole, 208 mg of dNbpy, 46 mg of copper (I) Bromide and 11 mg of copper (II) bromide.

The thickness of the surface-bound polymer coating was determined as between 150 and 250 nm according to the method of Example 1.

[0072] FIG. 1 shows typical polymer brushes consisting of a silane anchor and methacrylate residues.

Claims

Figures 2-3 are graphs showing the positive influence of the source configuration compared to the untreated surface for an ester type lubricant (Moebius HP500, 500 cSt / 20 °). The contact surfaces are glass & silicon, the polymer being the type of Example 1 on both surfaces (having a thickness of 250 nm in the dry state). FIG. 2 shows the positive influence of the source configuration compared to the untreated surface. At low velocities (<1 cm / s), the boundary lubrication regime is eliminated by the emitted lubricant in the grafted polymers. This phenomenon (the evaporation of the lubricant when the polymers are subjected to pressure) prevents the surface irregularities from interfering. At higher speed (> 1 cm / s), the role of the swelling polymers is minimized by the role of the lubricant in the surface separation. The shear is removed from the area of the polymers to only occur within the lubricant. In another way, the reduction in the coefficient of friction in comparison to the configuration of the untreated surface can be plotted graphically with the speed (see FIG. 3). As expected, the improvement is "low" at sufficient speeds because the polymers are remote from the tribological effect that occurs within the lubricant (shear). The increase in power occurs at low speeds (<1 cm / s), where the reduction in friction can reach 95%. [0076] For this lubricant of the ester family, the swelling polymers exert a positive tribological role from friction at low velocities (<1 cm / s) by canceling the negative boundary lubrication. In terms of wear, it is expected not to see any at all because of the complete separation of the surfaces from the ejection of the lubricant when the polymers are pressurized. 4-7 are diagrams of low-alkanes alkanes: hexadecane (5 cSt / 20 °) and vaselineol (36 cSt / 20 °). In the case of the low viscosity lubricants, the results of using the swelling polymers are even more pronounced over a broader range of speeds. Low lubricants have a poor ability to separate the surfaces efficiently. This results in random coefficients of friction (usually high, but not always). The source configuration can stabilize the frictional coefficients in a wide range of speeds at low values. The surfaces are well separated, the lower viscosity enabling low shear forces, ie low friction. Again, the use of the polymers results in better tribological performance, even for low viscosity lubricants where friction can be kept low over a wide range of speeds. [0078] FIGS. 8-9 are diagrams relating to the tests of the horological lubricant Moebius 9010 (150 cSt / 20 °). It is seen that the swelling effect is present because, at a very low coefficient of friction, which is between 0.007 and 0.03, occurs. [0079] The first aim of the polymers swelling in the lubricant is to achieve a suprasmaturation (friction coefficients below 0.05, no apparent wear) by freeing the right amount of lubricant (included within its matrix) within the contact. Their second object (as part of the first) is to suppress the boundary lubrication system which is conventionally obtained either at a low viscosity of the lubricant, high pressures or low speeds (or a combination of these factors). [0080] Both objectives have been achieved in this regard. The lubricants from the alkane and ester families and the classic horological lubricants have been successfully tested. These findings make the present invention a suitable candidate for a watchmaking application to increase the efficiency and reliability of the watch movements. The use of lower viscosity lubricants such as hexadecane or vaselineol has the best coefficients of friction (<0.01) in a wide range of speeds (from 0.01 to 6 cm / s). The combination of the right polymer (Example 1) with a sufficient thickness to prevent its destruction (tested here at 250 nm) and a compatible lower viscosity lubricant is the best compromise to achieve the suprash effect, whatever the requirements Within the contact (pressure, speed). [0082] Of course, the present invention is not limited to the illustrative example, but may be incorporated within the claims various variants and variations which will be apparent to those skilled in the art. In particular, the reaction conditions can be adapted with regard to the mono- and polymers used and / or the anchoring group and / or the crosslinking agent and / or the substrates. claims

1. Means for surface lubrication of an article, characterized in that the composition comprises one or more molecules having the general formula (1): AF 1) wherein: A is an anchoring group comprising a moiety selected from the group consisting of hydroxyl Groups, catechol groups, phosphate groups, phosphonate groups, carboxylic acid groups, amine groups, thiol groups, and any combination of two or more of the above-mentioned groups, and F is a functionalizing group, the functionalizing group comprising Branched polymer having a main chain and at least two side groups, at least one of the side groups being an unsubstituted C4-20 hydrocarbyl group or a substituted C4-20 hydrocarbyl group;And that the agent is swollen by a captured solvent.

2. The composition as claimed in claim 1, wherein at least one, preferably at least 50%, more preferably at least 80%, more preferably at least 90%, and most preferably all side groups, a C4-20 hydrocarbon group, more preferably a C4-18 hydrocarbon group, More preferably a C6-16 hydrocarbon group, and most preferably a C8-14 hydrocarbon group.

3. Agent according to claim 1 or 2, characterized in that the hydrocarbyl group is an alkyl ester group and preferably a linear alkyl ester group.

4. The composition according to claim 1, wherein the hydrocarbon group is selected from the group consisting of acrylate esters, methacrylate esters, styrene derivatives having at least one alkyl group attached to the aromatic ring, and any combination of two or more Of the above groups.

5. Agent according to claim 1, characterized in that the branched polymer comprises 50 to 500, preferably 100 to 450, more preferably 150 to 400, more preferably 200 to 350 and most preferably 220 to 300 pages.

6. Agent according to one of the preceding claims, characterized in that the branched polymer has a dry thickness of 50 to 2000 nm and particularly preferably between 200 and 1000 nm of the polymer brushes in order to improve the wear resistance.

7. A composition as claimed in any preceding claim, wherein all side groups are the same or different C6-20 hydrocarbon groups, preferably C8-18 hydrocarbon groups, more preferably C10-16 hydrocarbon groups, and most preferably C11-14 hydrocarbon groups.

8. The composition as claimed in claim 1, wherein at least one of the side groups has at least one functional group which is capable of crosslinking with a further molecule of the composition which has the general formula (1), the branched polymer being at least A block comprising at least 5 and preferably at least 10 side groups, at least two of these side groups each comprising at least one functional group capable of crosslinking with another molecule of the agent having the general formula (1).

9. Agent according to claim 1, characterized in that the branched polymer contains at least one further block which comprises at least 5, preferably at least 10, side groups, all side groups of this at least one further block containing no functional groups which are capable of crosslinking with a Further branched molecule of the branched polymer, the branched polymer particularly preferably comprising two of the further blocks, each of which comprises at least 5 and preferably at least 10 side groups, all side groups of these further blocks not containing any functional groups which are capable of crosslinking with a further one Molecule of the branched polymer, the block comprising at least 5 and preferably at least 10 side groups,Wherein at least two of these side groups each comprise at least one functional group which is capable of being cross-linked with another molecule of the compound having the general formula (1) between the other two blocks.

10. An article, comprising a substrate with at least one surface, characterized in that at least a part of the at least one surface is coated with an agent according to one of the preceding claims.

11. An article according to claim 10, characterized in that the at least one surface is coated with the composition consisting of a material selected from the group consisting of silicon, diamond-like carbon, silicon carbide, sapphire, steel, metal-coated steel, Nickel oxide, titanium oxide, a polymer, and any combination of two or more of the above materials.

12. The article according to claim 10, wherein the captured solvent is ionic liquids, mineral oils, vegetable oils, animal oils, synthetic oils, fats, waxes, polyol esters, neutral oils or vaseline and any combination of two or more of the above-mentioned materials contains.

13. A method of manufacturing an article according to claim 10, comprising the steps of: a) providing a substrate having at least one surface, b) binding at least one anchoring group selected from the group consisting of hydroxyl groups, Catechol groups, phosphate groups, phosphonate groups, carboxylic acid groups, amine groups, thiol groups, and any combination of two or more of the above groups, to at least one of the at least one surface of the substrate, c) providing at least one (D) graft polymerizing the at least one type of monomer onto the at least one anchoring moiety to form at least one branched polymer covalently bonded to the at least one anchoring moiety,And e) swelling the at least one branched polymer by trapping a solvent.

14. A process for producing an article according to claim 10, comprising the steps of: c ') providing at least one type of monomer, d') graft polymerizing said at least one type of monomer onto said at least one anchoring group selected from the group consisting of: Consisting of hydroxyl groups, catechol groups, phosphate groups, phosphonate groups, carboxylic acid groups, amine groups, thiol groups, and any combination of two or more of the above groups to form at least one branched polymer, (A) providing a substrate having at least one surface, and b ') bonding the at least one anchoring group to at least one of the at least one surface of the substrate,E) Sources of the at least one branched polymer by trapping a solvent.

15. A process for producing an article according to claim 10, comprising the following steps: d ') graft polymerizing said at least one type of monomer to form at least one branched polymer, a) providing a substrate having at least one surface , B) binding at least one anchoring group selected from the group consisting of hydroxyl groups, catechol groups, phosphate groups, phosphonate groups, carboxylic acid groups, amine groups, thiol groups, and any combination of two or more of the (F) bonding the at least one anchoring group to the at least one branched polymer, and e) swelling the solvent with the at least one branched polymer.

16. A timepiece comprising an article as claimed in any one of claims 10 to 12.