HK1250738B - Substrate comprising a surface coated with an epilame agent and method for coating such a substrate with epilame - Google Patents

Description

Substrate having a surface coated with an oil repellent agent and method of coating a substrate with an oil repellent agent

Technical Field

The present invention relates to the field of mechanics, particularly to the fields of timepieces and jewelry. More particularly, the present invention relates to a copolymer and a substrate, particularly a substrate for a component of a timepiece or piece of jewelry, having a surface at least partially coated with an oil-repellent agent containing the copolymer. The present invention also relates to a method for coating such a substrate with an oil-repellent agent, and a timepiece or piece of jewelry comprising a component having such a substrate.

Background Art

Various methods exist for modifying the surface condition of substrates by treating them with suitable agents, thereby specifically improving specific surface properties. For example, in the mechanical field, and particularly in the watchmaking and jewelry fields, the surfaces of components or elements are often treated with oil-repellent agents to control and reduce the surface energy of the surface during use. More specifically, the purpose of oil-repellent agents is to prevent oil or lubricants from spreading on components of timepieces or jewelry pieces by creating a hydrophobic and oleophobic surface that allows lubricants to remain at predetermined locations on the treated surface.

The standard oil-repellent coating method is the dip coating method. This method involves immersing the timepiece in an oil-repellent coating bath, which is a solution of an oil-repellent agent in a solvent at a given concentration. The oil-repellent effect depends on the concentration of the oil-repellent agent. In industry, the same oil-repellent coating bath is used to oil-repellent the timepiece for up to several months. As it is used, the amount of oil-repellent agent in this bath gradually decreases (a portion of the oil-repellent agent remains adsorbed/attached to the timepiece), and the amount of solvent in the oil-repellent solution also decreases due to evaporation. Therefore, the concentration of the oil-repellent agent in the oil-repellent coating bath varies during use. To limit these fluctuations, concentrated solutions of oil-repellent agent and/or solvent are regularly added to the oil-repellent coating bath in industry. However, these additions are made in a highly empirical manner, and current oil-repellent coating methods do not provide accurate information on the concentration of the oil-repellent agent. This results in significant variations in the oil-repellent effect between batches.

Summary of the Invention

The object of the present invention is to overcome the disadvantages of known oil repellents and known methods for applying oil repellents.

More specifically, an object of the present invention is to provide an oil repellent agent and an oil repellent agent coating method that make it possible to accurately know the oil repellent agent concentration over time, thereby making the entire oil repellent agent coating method more robust.

To this end, the present invention relates to copolymers comprising V units, N units, optionally at least one M unit and optionally at least one P unit, which are linked via covalent bonds via their backbone, wherein:

V is N is

M is P is

wherein R ₁ , R ₂ , R ₃ and R ₄ may be the same or different and are H, C ₁ -C ₁₀ alkyl, C ₁ -C ₁₀ alkenyl, preferably H or CH ₃ ,

W, X, Y, and Z may be the same or different and are spacer arms formed by heteroatoms or hydrocarbon chains, which hydrocarbon chains may contain at least one linear or branched heteroatom containing at least one carbon atom.

T, which may be the same or different, is a tracer group used to determine the concentration of the copolymer in the medium.

L can be the same or different and is a halogenated, preferably fluorinated, C ₁ -C ₂₀ carbon moiety,

A may be the same or different, and forms an anchoring moiety for the substrate and is selected from thiols, thioethers, thioesters, sulfides, sulfamides, silanols, alkoxysilanes, silane halides, hydroxyls, phosphates, protected or unprotected phosphonic acids, protected or unprotected phosphonate esters, amines, ammonium, nitrogenated heterocycles, carboxylic acids, anhydrides, catechols,

Q may be the same or different and is H, CH ₃ , or a hydrocarbon chain different from T, which hydrocarbon chain may contain at least one linear or branched saturated or unsaturated heteroatom and at least 2 carbon atoms.

The present invention also relates to a substrate having a surface, wherein at least a portion of the surface is coated with an oil repellent agent, the oil repellent agent comprising at least one compound in the form of a copolymer, wherein the copolymer comprises V units, N units, optionally at least one M unit and optionally at least one P unit, connected via covalent bonds via its main chain, wherein:

V is N is

M is P is

wherein R ₁ , R ₂ , R ₃ and R ₄ may be the same or different and are H, C ₁ -C ₁₀ alkyl, C ₁ -C ₁₀ alkenyl, preferably H or CH ₃ ,

W, X, Y, and Z may be the same or different and are spacer arms formed by heteroatoms or hydrocarbon chains, which hydrocarbon chains may contain at least one linear or branched heteroatom containing at least one carbon atom.

T can be the same or different and is a tracer group used to determine the concentration of the oil repellent in the oil repellent coating bath medium.

L can be the same or different and is a halogenated, preferably fluorinated, C ₁ -C ₂₀ carbon moiety,

A may be the same or different, and forms an anchoring moiety for the substrate and is selected from thiols, thioethers, thioesters, sulfides, sulfamides, silanols, alkoxysilanes, silane halides, hydroxyls, phosphates, protected or unprotected phosphonic acids, protected or unprotected phosphonate esters, amines, ammonium, nitrogenated heterocycles, carboxylic acids, anhydrides, catechols,

Q may be the same or different and is H, CH ₃ , or a hydrocarbon chain different from T, which hydrocarbon chain may contain at least one linear or branched saturated or unsaturated heteroatom and at least 2 carbon atoms.

This oil repellent makes it possible to monitor and follow its concentration in the oil repellent coating bath over time.

The present invention also relates to a method for coating at least a portion of a substrate surface with an oil repellent, comprising the steps of:

a) preparing an oil-repellent coating bath containing an oil-repellent agent comprising at least one copolymer as defined above,

b) optionally, preparing the substrate surface,

c) monitoring the concentration of the oil repellent in the oil repellent coating bath by means of a tracer group,

d) optionally, readjusting the concentration of the oil repellent agent in the oil repellent coating bath,

e) bringing the substrate surface into contact with the oil repellent agent in the oil repellent coating bath,

f) Drying.

The present invention also relates to the use of a copolymer as an oil repellent for at least a portion of the surface of a substrate, in particular for a watch or jewellery, wherein the copolymer comprises V units, N units, optionally at least one M unit and optionally at least one P unit, linked via covalent bonds via its main chain, wherein:

V is N is

M is P is

wherein R ₁ , R ₂ , R ₃ and R ₄ may be the same or different and are H, C ₁ -C ₁₀ alkyl, C ₁ -C ₁₀ alkenyl, preferably H or CH ₃ ,

W, X, Y, and Z may be the same or different and are spacer arms formed by heteroatoms or hydrocarbon chains, which hydrocarbon chains may contain at least one linear or branched heteroatom containing at least one carbon atom.

T can be the same or different and is a tracer group used to determine the concentration of the oil repellent in the oil repellent coating bath.

L can be the same or different and is a halogenated, preferably fluorinated, C ₁ -C ₂₀ carbon moiety,

A may be the same or different, and forms an anchoring moiety for the substrate and is selected from thiols, thioethers, thioesters, sulfides, sulfamides, silanols, alkoxysilanes, silane halides, hydroxyls, phosphates, protected or unprotected phosphonic acids, protected or unprotected phosphonate esters, amines, ammonium, nitrogenated heterocycles, carboxylic acids, anhydrides, catechols,

Q may be the same or different and is H, CH ₃ , a hydrocarbon chain different from T, which hydrocarbon chain may contain at least one linear or branched saturated or unsaturated heteroatom and at least 2 carbon atoms,

Used to monitor the concentration of oil repellent in oil repellent coating baths.

The invention also relates to a timepiece or piece of jewelry comprising an element comprising a substrate as defined above.

BRIEF DESCRIPTION OF THE DRAWINGS

Other features and advantages will emerge, by way of non-limiting description, from the following description with reference to the accompanying drawings, in which:

- Figure 1 represents the absorbance curve as a function of wavelength for different concentrations of copolymer I in a solvent.

- Figure 2 is a calibration curve for copolymer I showing the absorbance at a wavelength λ = 336 nm as a function of concentration.

- Figure 3 represents the absorbance curve as a function of wavelength for different concentrations of copolymer II in a solvent.

- Figure 4 is a calibration curve for copolymer II showing the absorbance at a wavelength λ = 336 nm as a function of concentration.

DETAILED DESCRIPTION

According to the invention, a substrate, in particular a substrate for an element of a timepiece or a piece of jewelry, has a surface, wherein at least a portion of the surface is coated with an oil-repellent agent, said oil-repellent agent containing at least one compound in the form of a copolymer, wherein the copolymer contains V units, N units, optionally at least one M unit and optionally at least one P unit, linked via covalent bonds via its main chain, wherein:

V is N is

M is P is

wherein R ₁ , R ₂ , R ₃ and R ₄ may be the same or different and are H, C ₁ -C ₁₀ alkyl, C ₁ -C ₁₀ alkenyl, preferably H or CH ₃ ,

W, X, Y, and Z may be the same or different and are spacer arms formed by heteroatoms or hydrocarbon chains, which hydrocarbon chains may contain at least one linear or branched heteroatom containing at least one carbon atom.

T can be the same or different and is a tracer group used to determine the concentration of the oil repellent in the oil repellent coating bath.

L can be the same or different and is a halogenated, preferably fluorinated, C ₁ -C ₂₀ carbon moiety,

A, which may be identical or different, forms an anchoring moiety for the substrate and is selected from thiols, thioethers, thioesters, sulfides, sulfamides, silanols, alkoxysilanes, silane halides, hydroxyls, phosphates, protected or unprotected phosphonic acids, protected or unprotected phosphonate esters, amines, ammonium, nitrogenated heterocycles such as imidazoles or pyridines, carboxylic acids, anhydrides, catechols,

Q may be the same or different and is H, CH ₃ , or a hydrocarbon chain different from T, which hydrocarbon chain may contain at least one linear or branched saturated or unsaturated heteroatom and at least 2 carbon atoms.

The present invention also relates to a copolymer for forming an oil repellent, comprising V units, N units, optionally at least one M unit and optionally at least one P unit connected via covalent bonds through its main chain, wherein:

V is N is

M is P is

wherein R ₁ , R ₂ , R ₃ and R ₄ may be the same or different and are H, C ₁ -C ₁₀ alkyl, C ₁ -C ₁₀ alkenyl, preferably H or CH ₃ ,

W, X, Y, and Z may be the same or different and are spacer arms formed by heteroatoms or hydrocarbon chains, which hydrocarbon chains may contain at least one linear or branched heteroatom containing at least one carbon atom.

T, which may be the same or different, is a tracer group used to determine the concentration of the copolymer in the medium.

L can be the same or different and is a halogenated, preferably fluorinated, C ₁ -C ₂₀ carbon moiety,

A, which may be identical or different, forms an anchoring moiety for the substrate and is selected from thiols, thioethers, thioesters, sulfides, sulfamides, silanols, alkoxysilanes, silane halides, hydroxyls, phosphates, protected or unprotected phosphonic acids, protected or unprotected phosphonate esters, amines, ammonium, nitrogenated heterocycles such as imidazoles or pyridines, carboxylic acids, anhydrides, catechols,

Q may be the same or different and is H, CH ₃ , or a hydrocarbon chain different from T, which hydrocarbon chain may contain at least one linear or branched saturated or unsaturated heteroatom and at least 2 carbon atoms.

Preferably, the copolymer contains only V, N and optionally M and/or P units.

The copolymers of the present invention may be statistical copolymers, wherein the V, N, M and P units are linked via their backbone in a statistical manner, i.e. randomly distributed, such that the statistical copolymers may be represented as follows:

The copolymer of the present invention may be a block copolymer comprising at least one block of V units linked via covalent bonds through their main chains, at least one block of N units linked via covalent bonds through their main chains, at least one of the blocks of V units and the blocks of N units optionally comprising at least one M unit and optionally at least one P unit linked via covalent bonds through their main chains, the blocks being linked to each other in a linear order via covalent bonds through their main chains.

Block copolymers can be represented as follows:

Preferably, the block copolymer contains a single V unit block and a single N unit block, at least one of the V unit block and the N unit block optionally containing at least one M unit and/or one P unit. When present, the number of M units y1 and the number of P units w1 in the V unit block can be different from the number of M units y2 and the number of P units w2, respectively, in the N unit block.

Preferably, the P units are integrated and distributed within the blocks formed by the N units, for example by statistical copolymerization of the P units with the N units to form a single block mostly formed by the N units and integrated within the N unit blocks.

Preferably, the M units are integrated and distributed within the blocks formed by the N units, for example by statistical copolymerization of the M units with the N units to form a single block mostly formed by the N units and integrated within the N unit blocks.

Advantageously, the identical or different W, X, Y, Z moieties are selected from C ₁ -C ₂₀ ester groups, preferably C ₂ -C ₁₀ , more preferably C ₂ -C ₆ , and even more preferably C ₂ -C ₅ , preferably linear alkyl ester groups, amide groups and styrene derivative groups.

Preferably, T, which is the same or different, is a UV absorbing moiety or a fluorophore. Such moieties, for example, allow the concentration of the copolymer to be determined spectroscopically. Obviously, any other type of tracer can be used by suitable detection and analytical means.

Advantageously, T, which may be identical or different, is a UV-absorbing moiety derived from a compound selected from the group consisting of benzotriazoles, triazines, phenones (especially benzophenones, acetophenones, hydroxyalkylphenones, hydroxyarylphenones, aminoalkylphenones, anthraquinones), acylphosphine oxides.

Advantageously, T, being identical or different, is a fluorophore moiety derived from a compound selected from the group consisting of fluorescein, naphthyl, anthracene, coumarin, rhodamine, fluorobenzoate.

The A functional group of interest can react with the surface of a substrate to be coated with the oil repellent, thereby forming an anchoring structure for the oil repellent at the substrate surface. Advantageously, the A group can be at the end of the copolymer.

Advantageously, the copolymer contains at least two different A groups.

The L functional groups of interest are responsible for the oil-repellent effect. They contain at least one halogen atom, preferably a fluorine atom. Preferably, L is a carbon moiety, i.e., a _C2 - _C20 , preferably a _C4 - _C10 , more preferably a _C6 - _C9 alkyl chain, which may be cyclic and preferably contains no heteroatoms. L is partially or fully halogenated. Advantageously, L is an at least partially fluorinated moiety, preferably a fully fluorinated moiety. L may also contain hydrogen atoms in the terminal groups. L is preferably a perfluorinated alkyl chain.

The Q functional group in the P unit of interest is used to improve the performance of the oil repellent and/or provide other functionality. For example, Q may preferably be a _C8 - _C20 alkyl chain to improve the resulting contact angle or a chain capable of forming crosslinking points during the temporary crosslinking step (step g). For example, the P unit may be derived from stearyl methacrylate.

Preferably, the copolymer contains, in mole percentages, 1-20%, preferably 3-10%, of V units, 50-99%, preferably 70-95%, of N units, 0-50%, preferably 1-20%, more preferably 5-20%, of M units, and 0-50%, preferably 0-20%, more preferably 0-10%, of P units, these percentages being based on the total number of units (w+x+y+z).

Advantageously, the copolymer contains from 10 to 350 units (w+x+y+z).

In a particularly advantageous embodiment, the M, N, and P units are selected to carry a plurality of different types of A groups, a plurality of L groups, preferably L groups of the same type, and possibly one or more Q groups, which can be of the same or different types, thereby refining and improving the properties of the oil repellent, thereby more particularly obtaining a universal oil repellent, which exhibits improved affinity with the substrate.

Preferably, the substrate surface, at least a portion of which is coated with an oil repellent, is made of a material selected from the group consisting of metals, doped or undoped metal oxides, polymers, sapphire, ruby, silicon, silicon oxide, silicon nitride, silicon carbide, DLC (diamond-like carbon), and alloys thereof.

More specifically, the substrate surface can be made of steel, noble metals such as gold, rhodium, palladium, platinum, or doped or undoped metal oxides of aluminum, zirconium, titanium, chromium, manganese, magnesium, iron, nickel, copper, zinc, molybdenum, silver, tungsten, or polyoxymethylene or acrylamide, and alloys thereof.

The present invention also relates to a method for coating at least a portion of a substrate surface with an oil repellent, comprising the steps of:

a) preparing an oil-repellent coating bath containing an oil-repellent agent comprising at least one copolymer as defined above,

b) optionally preparing the substrate surface, in particular cleaning it according to standard watchmakers' methods,

c) monitoring the concentration of the oil repellent in the oil repellent coating bath by means of a tracer group,

d) optionally, readjusting the concentration of the oil repellent agent in the oil repellent coating bath,

e) bringing the substrate surface into contact with the oil repellent agent in the oil repellent coating bath,

f) Drying.

Obviously, step a) can be carried out independently of the other steps b), c), d) and f) in time. Preferably, for example, when the oil repellent coating method is carried out continuously or when the same oil repellent coating bath is used multiple times, steps c) and d) can be repeated to monitor the concentration of the oil repellent over time and to keep the concentration constant for the implementation of step e).

Advantageously, when the T moiety is a UV-absorbing moiety or a fluorophore, the concentration of the oil repellent agent is measured spectroscopically (e.g., by measuring absorbance). In an intermediate step, prior to step c), a copolymer calibration curve is prepared. Thus, the copolymer is dissolved at varying concentrations in a solvent (the same solvent used to prepare the oil repellent agent solution), and the absorbance of each solution is measured spectroscopically as a function of wavelength.

Mark the wavelength at which the absorbance is at its maximum, then draw a calibration curve A=F(concentration) at the wavelength at which the absorbance is at its maximum. Derive the molar extinction coefficient of the polymer (Beer-Lambert law A=εcl).

To determine the concentration of the oil repellent agent in the oil repellent coating bath in step c), it is sufficient to measure the absorbance of the bath solution spectroscopically, and then deduce the concentration of the oil repellent agent in the oil repellent coating bath using a pre-prepared calibration curve. Therefore, the operator can accurately readjust the concentration by adding a solvent or a concentrated solution of the oil repellent agent according to step d). For example, in a continuous oil repellent coating method or when the same oil repellent coating bath is used multiple times, repeatedly measuring the oil repellent agent concentration allows tracking changes in the oil repellent agent concentration over time and thus maintaining a constant concentration.

Preferably, the oil repellent is prepared by statistical or block copolymerization of monomers capable of forming V units with monomers capable of forming N units, optionally with monomers capable of forming at least one M unit and optionally with monomers capable of forming at least one P unit.

Statistical copolymerization techniques are well known to those skilled in the art and do not require detailed description. One polymerization mode particularly suitable for statistical copolymerization is free radical copolymerization, carried out in solution or emulsion.

According to a first embodiment, the statistical copolymerization can be obtained in a single step by copolymerizing monomers with Z-T side chains with monomers with X-L side chains and optionally with Y-A side chains and/or optionally with W-Q side chains, preferably by free radical copolymerization.

According to another embodiment, the statistical copolymers can be obtained by copolymerization, preferably free radical polymerization, of monomers carrying suitable Z side chains with monomers carrying suitable X side chains and optionally monomers carrying side chains intended to carry A and/or optionally monomers carrying side chains intended to carry Q; these side chains are then modified after the polymerization (post-functionalization), for example by a ligation chemistry, in order to introduce the desired T, L functionalities and A and/or Q groups.

A particularly suitable polymerization mode for block copolymerization is the controlled successive copolymerization of the following monomers:

- monomers capable of forming at least one block of V units, optionally copolymerized with monomers capable of forming at least one M unit and/or monomers capable of forming at least one P unit,

- a monomer capable of forming at least one block of N units, optionally copolymerized with a monomer capable of forming at least one M unit and/or with a monomer capable of forming at least one P unit, the M or P units being identical or different.

Two polymerization methods that are particularly suitable for block copolymerization are atom transfer radical polymerization (ATRP) and reversible addition-fragmentation chain transfer polymerization (RAFT, in solution or emulsion).

According to a first variant, block copolymers can be obtained by polymerization, preferably controlled radical polymerization, of monomers carrying Z-T side chains, optionally with monomers carrying Y-A side chains and/or optionally with W-Q side chains, and then copolymerization, preferably controlled radical polymerization, of monomers carrying X-L side chains, optionally with monomers carrying Y-A side chains and/or optionally with monomers carrying identical or different W-Q, Y-A and W-Q side chains.

According to another embodiment, block copolymers can be obtained by polymerizing, preferably by controlled radical polymerization, monomers carrying suitable Z side chains, optionally with monomers carrying side chains intended to carry A and/or optionally with monomers carrying side chains intended to carry Q, and then copolymerizing, preferably by controlled radical polymerization, monomers carrying suitable X side chains, optionally with monomers carrying side chains intended to carry A and/or optionally with monomers carrying side chains intended to carry Q; these side chains are then modified, for example by a ligation chemical mechanism, in order to introduce the desired T, L functional groups and A and/or Q groups.

Preferably, the monomer is selected from the group consisting of acrylates, methacrylates, acrylamides, methacrylamides, vinyl groups, dienes, styrenes, and olefinic monomers. Particularly preferred are acrylates, methacrylates, acrylamides, methacrylamides, vinyl groups, and styrene monomers. These products are well known and most are commercially available or can be synthesized.

Particularly preferred monomers for forming the V unit containing the tracer group T are selected from the group consisting of: 2-H-benzotriazol-2-yl-hydroxyphenylethyl methacrylate, 2-(2H-benzotriazol-2-yl)-4-methyl-6-(2-propenyl)phenol, 2-(4-benzoyl-3-hydroxyphenoxy)ethyl acrylate, 4-allyloxy-2-hydroxybenzophenone, 2-naphthyl (meth)acrylate, fluorescent yellow O-(meth)acrylate, 9-anthrylmethyl (meth)acrylate, 3,8-diamino-5-ethyl-6-phenylphenanthridinium bromide-N,N'-diacrylamide, N-(1-naphthyl)-N-phenylmethacrylamide, and 7-[4-(trifluoromethyl)coumarin]methacrylamide. These monomers are commercially available and polymerizable.

Even more preferably, the monomer used to form the V unit containing the tracer group T is selected from 2-H-benzotriazol-2-yl-hydroxyphenylethyl methacrylate, 2-(2H-benzotriazol-2-yl)-4-methyl-6-(2-propenyl)phenol, 2-(4-benzoyl-3-hydroxyphenoxy)ethyl acrylate, and 4-allyloxy-2-hydroxybenzophenone. These monomers contain tracer groups that can be tracked by UV-visible spectroscopy, which is easier to implement in an industrial environment than fluorescence spectroscopy.

Particularly preferred monomers for forming the N, M and P units are:

R is the same as or different from R', =H, alkyl, Si(Me) ₃

Therefore, the copolymer used as an oil repellent can be easily obtained from commercial products in a single step or in a limited number of steps.

One of the copolymers preferably used in the present invention is a statistical copolymer having the following structure (1):

Another copolymer preferably used in the present invention is a statistical copolymer having the following structure (ll):

The copolymers used in the present invention can be obtained in the form of a powder or a viscous liquid. They can then be placed in a fluorinated solvent solution, such as a perfluorocarbon or fluorocarbon, perfluoropolyether, hydrofluoroolefin, or hydrofluoroether, preferably at a concentration of 50-250 mg/L, to obtain an oil repellent solution for treating the surface to be coated with the oil repellent.

In an embodiment, the oil repellent coating method according to the invention further comprises a temporary crosslinking step g) after step e) and preferably after step f), which can be carried out in particular in the presence of suitable functional groups provided in the Q side chains of the P units.

The substrate according to the present invention has a surface coated with an oil-repellent agent that can be synthesized in a simple and economical manner, exhibits affinity for any type of substrate, and exhibits improved resistance to cleaning operations compared to known oil-repellent agents. Components or articles having the substrate according to the present invention can be used in any type of application in the mechanical field, more particularly in precision mechanics, and in particular in watches and jewelry.

The method of the present invention monitors and tracks the changes in the oil repellent agent concentration in the oil repellent coating bath over time, thereby appropriately readjusting the oil repellent agent composition of the oil repellent coating bath. Consequently, the oil repellent agent concentration in the oil repellent coating bath remains substantially constant, ensuring a consistent oil repellent effect in each processed batch. This results in a robust oil repellent coating method.

The following examples are intended to illustrate the present invention but are not intended to limit the scope of the present invention.

Synthesis of 3-methacryloyloxypropyl methyl sulfide: (operated in a manner similar to that described in U.S. Patent 6,552,103)

Thiomethylpropional (4.05 mL), dichloromethane (100 mL) and triethylamine (8.2 mL) were added to a three-necked distillation flask with magnetic stirring and placed under a nitrogen atmosphere. The solution was cooled in an ice bath, and then methacryloyl chloride (3.8 mL) was added dropwise over 10 minutes. The reaction mixture was stirred at 0°C for 2 hours and then at ambient temperature overnight. 70 mL of water was added, and the reaction mixture was then transferred to a separatory funnel. The organic phase and the aqueous phase were separated. The organic phase was washed with HCl solution (pH = 4) until pH = 7 was reached, and then dried over Na ₂ SO _4. The solvent was then removed on a rotary evaporator to obtain the desired product in a yield of 97%.

RMN ¹ H (CDCl ₃ , 500 MHz): Chemical shift (ppm): 6.10 (s, 1H), 5.56 (s, 1H), 4.24 (t, 2H), 2.58 (t, 2H), 2.11 (s, 3H), 1.99 (m, 2H), 1.94 (s, 3H)

Example 1

The oil repellent is prepared in the form of a statistical copolymer by free radical polymerization of:

-(3-Methacryloxypropyl)dimethyl-methoxysilane

‐1H,1H,2H,2H-perfluorooctyl acrylate

-3-Methacryloxypropyl methyl sulfide (prepared as described above)

‐2-[3-(2H-benzotriazol-2-yl)-4-hydroxyphenyl]ethyl methacrylate

Synthesized according to the following procedure:

2-[3-(2H-benzotriazol-2-yl)-4-hydroxyphenyl]ethyl methacrylate (148 mg), (3-methacryloyloxypropyl)dimethyl-methoxysilane (166 μL), 3-methacryloyloxypropyl methyl sulfide (111 μL), and then 1H,1H,2H,2H-perfluorooctyl acrylate (2.0 mL) were added to a Schlenk flask previously degassed with nitrogen and filled with cyclohexanone (2 mL). The reaction mixture was purged with nitrogen for 5 minutes, followed by the addition of 0.8 mL of a hydrofluoroether (Novec ^™ HFE-7200 3M ^™ ) previously purged with nitrogen. 0.5 mL of a 0.228 mol/L azobisisobutyronitrile solution (AIBN) was then added. The reaction mixture was stirred and heated to 80°C for 3 hours. The polymer was coagulated in methanol and then washed with 3 x 30 mL of methanol. The polymer was obtained as a slightly off-white gel (yield = 95%).

The following statistical copolymer (I) was obtained:

Detect UV absorbance:

Copolymer (I) was dissolved in various concentrations in a fluorinated solvent of the Ecosolv (Moebius) type, the same solvent used in the oil-proof coating bath. The absorbance was measured for each concentration by UV-visible spectroscopy. The curve shown in Figure 1 was obtained. The wavelength at which the absorbance reached its maximum was confirmed to be 336 nm, which made it possible to determine the molar absorption coefficient of the polymer at its maximum absorbance at 336 nm. A calibration curve, as shown in Figure 2, was then prepared, showing absorbance as a function of copolymer concentration. This calibration curve then made it possible to determine the copolymer concentration in the oil-proof coating bath at any given moment by simply measuring the absorbance of samples taken from the oil-proof coating bath using UV-visible spectroscopy. Based on the results obtained, the operator knew whether it was necessary to add solvent or a concentrated oil-proofing agent solution to accurately readjust the oil-proofing agent concentration, thereby maintaining a substantially constant concentration during the oil-proofing agent coating process.

Example 2

The oil repellent is prepared in the form of a statistical copolymer by free radical polymerization of:

‐2-(2,2-diphenyl-benzo[1,3]dioxy-5-yl)-ethyl-acrylate (obtained by reacting 2,2-diphenyl-benzo[1,3]dioxy-5-yl)-ethylamine (commercially available) with acryloyl chloride)

‐1H,1H,2H,2H-perfluorooctyl acrylate

-3-Acryloxypropyl methyl sulfide (obtained by the method described in: Preparation of biomimetic polymer hydrogel materials for contact lenses, Bertozzi, Carolyn et al., U.S. Patent 6552103)

‐2-[3-(2H-benzotriazol-2-yl)-4-hydroxyphenyl]ethyl methacrylate

Synthesized according to the following procedure:

2-[3-(2H-benzotriazol-2-yl)-4-hydroxyphenyl]ethyl methacrylate (162 mg), 2-(2,2-diphenyl-benzo[1,3]dioxol-5-yl)-ethyl acrylate (373 mg), 3-acryloyloxypropyl methyl sulfide (111 μL), and then 1H,1H,2H,2H-perfluorooctyl acrylate (2.1 mL) were added to a Schlenk flask previously degassed with nitrogen and filled with cyclohexanone (2 mL). The reaction mixture was purged with nitrogen for 5 minutes, followed by the addition of 0.8 mL of a hydrofluoroether (Novec ^™ HFE-7200 3M ^™ ) previously purged with nitrogen. 0.55 mL of a 0.228 mol/L azobisisobutyronitrile solution (AIBN) was then added. The reaction mixture was stirred and heated to 80°C for 3 hours. The polymer was coagulated in methanol and then washed with 3 x 30 mL of methanol. The polymer was obtained as a slightly off-white gel (yield = 92%).

The following statistical copolymers were obtained:

The groups protecting the catechol functional groups of the polymer are then removed (deprotection of the catechol functional groups) according to the following procedure:

The polymer obtained above was dissolved in 50 mL of a fluorinated solvent (Novec ^™ HFE-72003M ^™ ), followed by the addition of 5 mL of trifluoroacetic acid with stirring. The reaction was allowed to stand with stirring for 1 hour. The mixture was then washed with 4 x 40 mL of water, the organic phase collected, and the fluorinated solvent reduced to a minimum. The polymer was coagulated in methanol and then washed with 3 x 30 mL of methanol. The resulting polymer was a slightly off-white gel (yield = 75%).

The following statistical copolymer (II) was obtained:

Detect UV absorbance:

Copolymer (II) was dissolved in various concentrations in a fluorinated solvent of the Ecosolv (Moebius) type, the same solvent used in the oil-proof coating bath. The absorbance was measured for each concentration using UV-visible spectroscopy. The curve shown in Figure 3 was obtained. The wavelength at which the absorbance reached its maximum was confirmed to be 336 nm, which made it possible to determine the molar absorption coefficient of the polymer at its maximum absorbance at 336 nm. A calibration curve, as shown in Figure 4, was then prepared, showing absorbance as a function of copolymer concentration. This calibration curve then made it possible to determine the copolymer concentration in the oil-proof coating bath at any given moment by simply measuring the absorbance of samples taken from the oil-proof coating bath using UV-visible spectroscopy. Based on the results obtained, the operator knew whether it was necessary to add solvent or a concentrated oil-proofing agent solution to accurately readjust the oil-proofing agent concentration, thereby maintaining a substantially constant concentration during the oil-proofing agent coating process.

Claims (29)

1. A copolymer comprising V units, N units, at least one M unit, and optionally at least one P unit covalently linked through its main chain, wherein: V is N is M is P is _R1 , _R2 , _R3 , and _R4 can be the same or different, and can be H, _C1 - _C10 alkyl, or _C1 - _C10 alkenyl. W, X, Y, and Z can be the same or different, and are spacer arms formed by heteroatoms or hydrocarbon chains. This hydrocarbon chain can contain at least one straight-chain or branched heteroatom with at least one carbon atom. T can be the same or different, and is a tracer group used to determine the concentration of the copolymer in the medium. It is a UV-absorbing group derived from compounds selected from: benzotriazole, triazine, benzophenone, and acylphosphine oxide. L can be the same or different, and is a halogenated _C1 - _C20 carbon structure part. A can be the same or different, forming the anchoring structure portion for the substrate, and is selected from sulfides, silanols, alkoxysilanes, silane halides, hydroxyl groups, phosphate esters, protected or unprotected phosphonic acids, protected or unprotected phosphonate esters, amines, ammonium, nitrided heterocycles, carboxylic acids, acid anhydrides, and catechols. Q can be the same or different, and is H, _CH3 , a hydrocarbon chain different from T. This hydrocarbon chain can contain at least one straight or branched saturated or unsaturated heteroatom and at least two carbon atoms. The copolymer contains 3-10% V units, 70-95% N units, 1-20% M units and 0-20% P units by molar percentage. 2. The copolymer according to claim 1, wherein _R1 , _R2 , _R3 , and _R4 may be the same or different, and are H or _CH3 . 3. The copolymer according to claim 1, wherein L can be the same or different, and is a fluorinated _C1 - _C20 carbon structural moiety. 4. The copolymer according to claim 1, wherein W, X, Y, and Z may be the same or different, and are selected from _C1 - _C20 ester groups, amide groups, and styrene derivative groups. 5. The copolymer according to claim 1, wherein L is a _C2 - _C20 carbon structural moiety. 6. The copolymer according to claim 5, wherein L is a _C4 - _C10 carbon structural moiety. 7. The copolymer according to claim 1, wherein L is at least partially fluorinated structural portion. 8. The copolymer according to claim 7, wherein L is a fully fluorinated structural moiety. 9. The copolymer according to claim 1, characterized in that the copolymer contains 10-350 units. 10. The copolymer according to claim 1, wherein A is selected from thiols, thioethers, thioesters or thioamides. 11. A substrate having a surface, at least a portion of which is coated with an oil repellent, characterized in that the oil repellent contains at least one compound in the form of a copolymer, wherein the copolymer contains V units, N units, at least one M unit, and optionally at least one P unit covalently linked through its main chain, wherein: V is N is M is P is _R1 , _R2 , _R3 , and _R4 can be the same or different, and can be H, _C1 - _C10 alkyl, or _C1 - _C10 alkenyl. W, X, Y, and Z can be the same or different, and are spacer arms formed by heteroatoms or hydrocarbon chains. This hydrocarbon chain can contain at least one straight-chain or branched heteroatom with at least one carbon atom. T can be the same or different, and is a tracer group used to determine the concentration of the oil-repellent agent in the oil-repellent coating bath medium. It is a UV-absorbing group derived from compounds selected from: benzotriazole, triazine, benzophenone, and acylphosphine oxide. L can be the same or different, and is a halogenated _C1 - _C20 carbon structure part. A can be the same or different, forming the anchoring structure portion for the substrate, and is selected from sulfides, silanols, alkoxysilanes, silane halides, hydroxyl groups, phosphate esters, protected or unprotected phosphonic acids, protected or unprotected phosphonate esters, amines, ammonium, nitrided heterocycles, carboxylic acids, acid anhydrides, and catechols. Q can be the same or different, and is H, _CH3 , a hydrocarbon chain different from T. This hydrocarbon chain can contain at least one straight or branched saturated or unsaturated heteroatom and at least two carbon atoms. The copolymer contains 3-10% V units, 70-95% N units, 1-20% M units and 0-20% P units by molar percentage. 12. The substrate according to claim 11, wherein _R1 , _R2 , _R3 , and _R4 may be the same or different, and are H or _CH3 . 13. The substrate according to claim 11, wherein L can be the same or different, and is a fluorinated _C1 - _C20 carbon structure portion. 14. The substrate according to claim 11, wherein W, X, Y, and Z may be the same or different, and are selected from _C1 - _C20 ester groups, amide groups, and styrene derivative groups. 15. The substrate according to claim 11, wherein L is a _C2 - _C20 carbon structure portion. 16. The substrate according to claim 15, wherein L is a _C4 - _C10 carbon structure portion. 17. The substrate according to claim 11, wherein L is at least partially fluorinated structural portion. 18. The substrate according to claim 17, wherein L is a fully fluorinated structural portion. 19. The substrate according to claim 11, wherein the copolymer contains 10-350 units. 20. The substrate according to claim 11, characterized in that at least a portion of its surface coated with an oil repellent is made of a material selected from: metals, metal oxides, polymers, sapphire, ruby, silicon, silicon oxide, silicon nitride, silicon carbide, DLC (diamond-like carbon), and alloys thereof. 21. The substrate according to claim 11, wherein A is selected from thiols, thioethers, thioesters or thioamides. 22. A method for coating at least a portion of a substrate surface with an oil-repellent agent, comprising the following steps: a) Preparing an oil-resistant coating bath containing an oil-resistant agent comprising at least one copolymer as defined in any one of claims 1-10. b) Optionally, prepare the substrate surface. c) Monitor the concentration of the oil-repellent agent in the oil-repellent coating bath using tracer groups. d) Optionally, adjust the concentration of the oil-repellent agent in the oil-repellent coating bath. e) Allows the substrate surface to come into contact with the oil-repellent agent in the oil-repellent coating bath. f) Drying. 23. The method of coating at least a portion of a substrate surface with an oil repellent according to claim 22, characterized in that the oil repellent coating method is continuous and steps c) and d) are repeated over time. 24. The method of coating at least a portion of a substrate surface with an oil repellent according to claim 22, characterized in that the oil repellent is prepared by copolymerizing a monomer capable of forming V units with a monomer capable of forming N units, a monomer capable of forming at least one M unit, and optionally with a monomer capable of forming at least one P unit. 25. The method of coating at least a portion of a substrate surface with an oil repellent according to claim 22, characterized in that after step e), the method further includes a temporary crosslinking step g). 26. The method of coating at least a portion of a substrate surface with an oil repellent according to claim 22, characterized in that the monomers capable of forming V units, N units, M units, and P units are selected from acrylates, methacrylates, acrylamide, methacrylamide, vinyl groups, and styrene monomers. 27. Use of a copolymer as an oil repellent on at least a portion of the surface of a substrate, wherein the copolymer contains V units, N units, at least one M unit, and optionally at least one P unit covalently linked through its main chain, wherein: V is N is M is P is _R1 , _R2 , _R3 , and _R4 can be the same or different, and can be H, _C1 - _C10 alkyl, or _C1 - _C10 alkenyl. W, X, Y, and Z can be the same or different, and are spacer arms formed by heteroatoms or hydrocarbon chains. This hydrocarbon chain can contain at least one straight-chain or branched heteroatom with at least one carbon atom. T can be the same or different, and is a tracer group used to determine the concentration of the oil-repellent agent in the oil-repellent coating bath medium. It is a UV-absorbing group derived from compounds selected from: benzotriazole, triazine, benzophenone, and acylphosphine oxide. L can be the same or different, and is a halogenated _C1 - _C20 carbon structure part. A can be the same or different, forming the anchoring structure portion for the substrate, and is selected from sulfides, silanols, alkoxysilanes, silane halides, hydroxyl groups, phosphate esters, protected or unprotected phosphonic acids, protected or unprotected phosphonate esters, amines, ammonium, nitrided heterocycles, carboxylic acids, acid anhydrides, and catechols. Q can be the same or different, and is H, _CH3 , a hydrocarbon chain different from T. This hydrocarbon chain can contain at least one straight or branched saturated or unsaturated heteroatom and at least two carbon atoms. The copolymer contains 3-10% V units, 70-95% N units, 1-20% M units, and 0-20% P units by molar percentage. Used to monitor the concentration of oil-resistant agent in oil-resistant paint baths. 28. The use according to claim 27, wherein A is selected from thiols, thioethers, thioesters or thioamides. 29. A timing device or jewelry piece comprising an element having a base material according to any one of claims 11-21.