CH710889B1 - Substrate comprising a surface coated with an epilame agent and method of epilamating such a substrate. - Google Patents

Abstract

The invention relates to a substrate comprising a surface at least a part of which is covered with an epilame agent comprising at least one compound in the form of a block copolymer comprising at least one block of units M associated by covalent bonds with their main chains, and at least one block of units N associated by covalent bonds by their main chains, said blocks being connected to each other by covalent bonds by their main chains in linear sequences, where R 1, R 2, identical or different are H, C 1 -C 10 alkyl, C 1 -C 10 alkenyl; Y, X, which may be identical or different, are spacer arms consisting of a heteroatom or a hydrocarbon-based chain which may contain at least one heteroatom, comprising at least one carbon atom; A, identical or different, constitutes an anchoring group to the substrate, and is chosen from thiols, thioethers, thioesters, sulfides, thioamides, silanols, alkoxysilanes, silane halides, hydroxyls, phosphates, protected or non-protected phosphonic acids, protected phosphonates. or not, amines, ammoniums, nitrogen heterocycles, carboxylic acids, anhydrides, catechol; L, identical or different, is a C 1 -C 20 halogenated carbon group. The invention also relates to a process for the epilamation of such a substrate, as well as to a timepiece or jewelery piece comprising an element comprising such a substrate.

Description

Description

Field of the Invention The present invention relates to the field of mechanics and in particular to the field of watchmaking or jewelry. It relates more particularly to a substrate, in particular a substrate of an element of a timepiece or of jewelry comprising a surface covered at least partially with an epilam agent. It also relates to a method of epilamating such a substrate, as well as a timepiece or jewelry comprising an element comprising such a substrate.

BACKGROUND OF THE INVENTION There are various methods for modifying the surface state of a substrate by treatment with an appropriate agent so as to specifically improve certain surface properties. For example, in the field of mechanics, and in particular in the field of watchmaking, but also in the field of jewelry, epilamage of a surface of a part or of an element is often carried out means of an epilam agent in order to control and reduce the surface energy of said surface during its use. More particularly, the purpose of an epilam agent is to prevent the spreading of oils or lubricants on the elements of a timepiece or of jewelry by forming a hydrophobic and lipophobic surface allowing the lubricant to remain at a predetermined place of the treated surface.

However, the substances currently used for epilamage have various drawbacks. More specifically, the known epilateral agents, such as Fixodrop® FK / BS from Moebius® or the Fluorad ™ range from 3M ™, exhibit poor resistance to horological washing. The patent application US 2012/0 088 099 partially solves this problem by proposing the use of an epilam agent carrying a catechol function at the end of the chain, this catechol function being capable of being fixed securely to the surface of the substrates. However, the resistance to horological washing of these epilamic agents has not been improved on all substrates, in particular on gold and steel which are very common substrates in the field of watchmaking or jewelry. Thus, the use of known epilâma agents is generally limited to certain materials, which obliges the user to have at his disposal different types of epilâma agents depending on the nature of the surfaces to be treated. A solution to solve this problem is described, for example, in application WO 2012/085 130. This solution consists in using as epilame composition a mixture of compounds of different nature (thiol and biphosphonic) whose synergistic effect promotes the adhesion of the epilame on the substrate. However, the synthesis of each of these compounds requires at least four steps, so that the synthesis process for the entire epilam composition is long and complex.

Claims (16)

SUMMARY OF THE INVENTION The aim of the invention is in particular to overcome the various drawbacks of known epilateral agents. More specifically, an objective of the invention is to provide an epilam agent offering increased resistance to washing compared to known epilame agents. The invention also aims to provide a universal epilam agent which can be used for any type of material. The invention also aims to provide an epilam agent which is simple to manufacture in a few steps. To this end, the present invention relates to a substrate comprising a surface at least part of which is covered with an epilam agent. According to the invention, said epilam agent comprises at least one compound in the form of a block copolymer comprising at least one block of Μ units associated by covalent bonds by their main chains, and at least one block of units N associated by covalent bonds by their main chains, said blocks being connected together by covalent bonds by their main chains in linear sequences, where

 I * where Ri, R ₂ , identical or different, are H, a C1-C10 alkyl group, C1-C10 alkenyl, and preferably H, CH ₃ ; Y, X, identical or different, are spacer arms consisting of a heteroatom or of a hydrocarbon chain which may contain at least one heteroatom, linear or branched, comprising at least one carbon atom; A, identical or different, constitutes an anchoring group to the substrate, and is chosen from the group comprising thiols, thioethers, thioesters, sulfides, thioamides, silanols, alkoxysilanes, silane halides, hydroxyls, phosphates, phosphonic acids, protected or not , protected or unprotected phosphonates, amines, ammoniums, nitrogenous heterocycles, carboxylic acids, anhydrides, catechol; CH 710 889 B1 L, identical or different, is a halogenated C ₁ -C ₂ carbon group, preferably fluorinated. Such epilam agent has improved resistance to washing and has a universal character, allowing its use for any type of material. The present invention also relates to a process for epilamating at least part of a surface of a substrate comprising the steps of: a) preparation of an epilam agent comprising at least one block copolymer as defined above b) optionally, preparation of the substrate surface c) bringing the substrate surface into contact with the epilam agent d) drying. The present invention also relates to the use of a block copolymer comprising at least one block of Μ units associated by covalent bonds by their main chains, at least one block of N units associated by covalent bonds by their main chains , at least one of the block of units Μ and of the block of units N optionally comprising at least one unit P, associated by covalent bonds by their main chains, said blocks being connected together by covalent bonds by their main chains in linear sequences where Μ is

where Ri, R ₂ , R ₃ , identical or different, are H, a C1-C10 alkyl group, C1-C10 alkenyl, and preferably H, CH ₃ ; Y, X, identical or different, are spacer arms consisting of a heteroatom or of a hydrocarbon chain which may contain at least one heteroatom, linear or branched, comprising at least one carbon atom; A, identical or different, constitutes an anchoring group to the substrate, and is chosen from the group comprising thiols, thioethers, thioesters, sulfides, thioamides, silanols, alkoxysilanes, silane halides, hydroxyls, phosphates, phosphonic acids, protected or not , protected or unprotected phosphonates, amines, ammoniums, nitrogenous heterocycles, carboxylic acids, anhydrides, catechol; L, identical or different, is a carbon-based C ₁ -C ₂ o halogen group, preferably fluorinated; R ₄ , identical or different, is H, CH ₃ , a hydrocarbon chain which may contain at least one heteroatom, linear or branched, saturated or unsaturated, comprising at least 2 carbon atoms, as epilamic agent of at least part of a surface of a substrate, in particular intended for watchmaking or jewelry. The present invention also relates to a timepiece or jewelry comprising an element comprising a substrate as defined above. Detailed description of the invention In accordance with the present invention, a substrate, in particular a substrate of an element of a timepiece or of jewelry, comprises a surface of which at least a part is covered with an agent. epilam, said epilam agent comprising at least one compound in the form of a block copolymer comprising at least one block of Μ units associated by covalent bonds by their main chains, and at least one block of N units associated by covalent bonds by their main chains, at least one of the block of units Μ and of the block of units N optionally comprising at least one unit P, associated by covalent bonds by their main chains, said blocks being connected together by covalent bonds by their main strings in linear sequences, where Ri R ₂ Μ is' - ^ ch ₂ —ç — N is —- ^ ch ₂ —P is - ^ ch ₂ —c ~ ^ ~ To L where Ri, R ₂ , R ₃ , identical or different, are H, a C1-C10 alkyl group, C1-C10 alkenyl, and preferably H, CH ₃ ; Y, X, identical or different, are spacer arms consisting of a heteroatom or of a hydrocarbon chain which may contain at least one heteroatom, linear or branched, comprising at least one carbon atom; A, identical or different, constitutes an anchoring group to the substrate, and is chosen from the group comprising thiols, thioethers, thioesters, sulfides, thioamides, silanols, alkoxysilanes, silane halides, hydroxyls, phosphates, CH 710 889 B1 protected or unprotected phosphonic acids, protected or unprotected phosphonates, amines, ammoniums, nitrogen heterocycles, such as imidazole or pyridine, carboxylic acids, anhydrides, catechol; L, identical or different, is a halogenated C ₁ -C ₂₀ carbon group, preferably fluorinated; R ₄ , identical or different, is H, CH ₃ , a hydrocarbon chain which may contain at least one heteroatom, linear or branched, saturated or unsaturated, comprising at least 2 carbon atoms. Preferably, the block copolymer comprises at least one block of Μ units associated by covalent bonds by their main chains, and at least one block of N units associated by covalent bonds by their main chains, at least one of the block of units Μ and of the block of units N optionally comprising at least one unit P, associated by covalent bonds by their main chains, said blocks being connected to each other by covalent bonds by their main chains in linear sequences, where

where Ri, R ₂ , R ₃ , identical or different, are H, a C1-C10 alkyl group, C1-C10 alkenyl, and preferably H, CH ₃ ; Y, X, identical or different, are spacer arms consisting of a heteroatom or of a hydrocarbon chain which may contain at least one heteroatom, linear or branched, comprising at least one carbon atom; A, identical or different, constitutes an anchoring group to the substrate, and is chosen from the group comprising thiols, thioethers, thioesters, sulfides, thioamides, silanols, alkoxysilanes, silane halides, hydroxyls, phosphates, phosphonic acids, protected or not , protected or unprotected phosphonates, amines, ammoniums, nitrogenous heterocycles, such as imidazole or pyridine, carboxylic acids, anhydrides, catechol; L, identical or different, is a halogenated C1-C20 carbon group, preferably fluorinated; R ₄ , identical or different, is H, CH ₃ , a hydrocarbon chain which may contain at least one heteroatom, linear or branched, saturated or unsaturated, comprising at least 2 carbon atoms, with the exception of the copolymer:

Preferably, the block copolymer only comprises or consists of blocks of Μ units and blocks of N units, at least one of the block of Μ units and the block of N units comprising optionally at least one P unit. The blocks of Μ units and of N units, which optionally comprise at least one P unit, are linked together by covalent bonds by their main chains in linear sequences, so that the block copolymer can be written under the form:

Preferably, the block copolymer comprises a single block of Μ units and a single block of N units, at least one of the block of Μ units and the block of N units optionally comprising at least one unit. P. When present, the number z of units P in the block of units ités may vary from the number w of units P in the block of units N. CH 710 889 B1 Preferably, the P units are integrated and distributed within the block composed of the N units, for example by statistical copolymerization of P units with the N units to form a single block consisting mainly of N units and assimilated to a block of N units. Advantageously, the groups Y, X, identical or different, are chosen from the group comprising ester groups of C ₁ -C ₂₀ , preferably C ₂ -C ₁₀ , more preferably C ₂ -C ₆ , and even more preferably in C ₂ -C ₅ , preferably alkyl ester groups, preferably linear, amide groups, and groups derived from styrene. The functional groups of interest A are capable of reacting with the surface of the substrate to be epilated, so as to form groups for anchoring the epilam agent to the surface of the substrate. Advantageously, groups A can also be provided at the end of the block of units Μ. Advantageously, the block of units Μ comprises at least two different groups A. The functional groups of interest L are responsible for the epilam effect. They comprise at least one halogen atom, preferably a fluorine atom. Preferably, L is a C ₂ -C ₂₀ carbon group, preferably C4-C10, and more preferably C ₆ -C ₉ . L is partially or completely halogen. Advantageously, L is an at least partially fluorinated group, and preferably completely fluorinated. L can also include a hydrogen atom on the terminal group. The functional groups of interest R ₄ of the P units are used to modify the properties of the epilam agent and / or provide other functions. For example, R ₄ may be an alkyl chain used to modify the contact angle obtained or a chain capable of constituting crosslinking points during a complementary crosslinking step (step e). It is obvious that R ₄ present in the block of units Μ may be different from R ₄ present in the block of units N. Preferably, the block copolymer comprises between 0.1% and 50%, preferably between 5% and 30%, and more preferably between 5% and 20% of Μ units, between 1% and 99.9%, preferably between 50% and 99.9%, and more preferably between 80% and 95% of N units, and between 0% and 50%, preferably between 0% and 30%, and more preferably between 0% and 10% of P units , the percentages being expressed relative to the total number of units (x + y + z + w). Advantageously, the block copolymer comprises between 10 and 350 units (x + y + z + w). In a particularly advantageous manner, the units Μ, N, P are chosen to carry several groups A of different nature, several groups L, preferably of the same nature, and possibly one or more groups R ₄ which may be identical or of a different nature, so as to refine and improve the properties of the epilam agent, in order to obtain more specifically a universal epilam agent and having an improved affinity with the substrate. Preferably, the surface of the substrate, at least a part of which is covered with the epilam agent, is made of a material chosen from the group comprising metals, metal oxides, doped or not, silicon, silicon oxides , silicon nitrides, silicon carbides, and their alloys, DLC (Diamond Like Carbon), polymers, sapphire, ruby. More precisely, the surface of the substrate can be made of steel, or of noble metals such as gold, rhodium, palladium, platinum, or of metal oxides, doped or not with aluminum, zirconium, titanium, chromium, manganese, magnesium, iron, nickel, copper, zinc, molybdenum, silver, tungsten, as well as their alloys, or in polyoxymethylene or in acrylamide. The present invention also relates to a process for epilamating at least part of a surface of a substrate comprising the steps of: a) preparation of an epilam agent comprising at least one block copolymer as defined above b) optionally, preparation of the surface of the substrate, in particular by cleaning according to standard watchmaking processes c) bringing the substrate surface into contact with the epilam agent d) drying. Preferably, the preparation of the epilam agent is carried out by block copolymerization of monomers capable of forming at least one block of Μ units and of monomers capable of forming at least one block of N units, the copolymerization into block of monomers capable of forming at least one block of Μ units or at least one block of N units optionally effected with monomers capable of forming at least one P unit. Block copolymerization techniques are well known to those skilled in the art and do not require a detailed description. A particularly suitable mode of polymerization is the successive controlled copolymerization: - monomers capable of forming at least one block of Μ units and optionally with monomers capable of forming at least one P unit CH 710 889 B1 - monomers capable of forming at least one block of N units, and optionally with monomers capable of forming at least one identical or different P, P unit. Two particularly suitable modes of polymerization are radical copolymerization by atom transfer (ATRP) and radical polymerization controlled by reversible chain addition-fragmentation transfer (RAFT), in solution or in emulsion. In a first variant, the block copolymer can be obtained by polymerization, preferably controlled radical, of monomers carrying the side chains Y-A with optionally monomers carrying the side chains R ₄ , followed by copolymerization, preferably radical controlled, of monomers carrying the side chains XL with optionally monomers carrying the side chains R ₄ , R ₄ identical or different. According to another variant, the block copolymer can be obtained by polymerization, preferably controlled radical, of monomers carrying the adequate side chains Y with optionally monomers carrying side chains intended to carry R ₄ , followed by the copolymerization, controlled radical preference, of monomers carrying the appropriate side chains X with optionally monomers carrying side chains intended to carry R ₄ , then the side chains are modified, for example by "dick chemistry", in order to introduce therein the functional groups of interest A, L and groups R ₄ . Preferably, the monomers are chosen from the group comprising the acrylate, methacrylate, acrylamide, methacrylamide, vinyl, diene, styrenic and olefinic monomers. The acrylate, methacrylate, acrylamide, methacrylamide, vinyl and styrenic monomers are particularly preferred. These products are known and for the most part available on the market or accessible in a synthesis step. The particularly preferred monomers are: CH 710 889 B1

R equal or different from R '= H, Alkyl, Si (Me) ₃

Thus, the copolymer used as an epilam agent can be easily obtained in a limited number of steps from marketed products. CH 710 889 B1 One of the copolymers preferably used in the present invention has the following structure (I)

Another copolymer preferably used in the present invention has the following structure (II):

The copolymers used in the invention can be obtained in the form of powder or viscous liquid. They can then be dissolved in a fluorinated solvent, such as perfluorinated or fluorinated hydrocarbons, perfluoropolyethers, hydrofluoroolefins, hydrofluoroethers, at concentrations preferably between 50 mg / L and 250 mg / L, in order to obtain a solution of epilam agent, which will be used for the treatment of the surfaces to be epilamated. According to the variants, the epilamage process according to the invention may further comprise, after step c), a step e) of additional crosslinking, made possible in particular by the presence of the functional groups of appropriate interest provided on the side chains R ₄ of the R units The substrate according to the invention has a surface covered with an epilam agent which is simple and economical to synthesize, having an affinity with any type of substrate and improved resistance to washing compared to known epilâma agents. An element or a part having a substrate in accordance with the invention can be used in any type of application in the mechanical field, and more particularly in precision mechanics, and in particular watchmaking and jewelry. The following examples illustrate the present invention without, however, limiting its scope. Example 1 An epilam agent is synthesized in the form of a block copolymer by controlled radical polymerization of: - 1H, 1H, 2H, 2H-Perfluorodecylmethacrylate - 3-acryloxopropyl methyldimethoxysilane / 3-acryloxopropyl methyl thioether (obtained according to the procedure described in the literature: Preparation of biomimetic polymer hydrogel materials for contact lenses Bertozzi, Carolyn et al. US 6 552 103) according to the following procedure: CH 710 889 B1 In a Schlenk tube containing cyclohexanone (1 mL) and 2 mL of Novec ™ hydrofluoroether HFE7200 (3M ™) previously degassed with nitrogen, are added the RAFT polymerization agent (42 pL) and 1H, 1H, 2H , 2H-Perfluorodecylacrylate. 0.2 mL of 0.122mol / L azobisisobutyronitrile (AIBN) solution is added. The reaction medium is stirred and heated at 85 ° C for 6 h. The polymer is coagulated in methanol and then washed with 3 * 30 mL. The polymer is obtained in the form of a yellowish powder. The polymer previously obtained is dissolved in cyclohexanone (1 mL) and 2 mL of Novec ™ hydrofluoroether HFE-7200 (3M ™) previously degassed with nitrogen, then 3-acryloxopropyl methyldimethoxysilane (211 pL) and 3-acryloxopropyl methyl thioether (154 pL) are added. 0.2 mL of 0.122 mol / L AIBN solution is added. The reaction medium is stirred and heated at 85 ° C for 12 h. The polymer is coagulated in methanol and then washed with 3 * 50 mL. The polymer is obtained in the form of a yellowish powder (yield = 76%). The following block copolymer is obtained:

Example 2: Resistance to washing Preparation of substrates: Before the epilam treatment, substrates of different types are cleaned by standard watchmaking processes. More particularly, the parts are cleaned with a solution of Rubisol in the presence of ultrasound, rinsed 3 times with isopropyl alcohol, then dried with hot air. Epilamous treatment of substrates: The substrates are epilamated by immersion (about 5 min) in a solution of the epilam agent (solvent: Vedrei® Suprion ™ from DuPont ™ at 250 mg / L) then drying with hot air. Resistance to washing: The resistance to washing of epilate agents is evaluated after 3 successive washes (standard watch washing with a solution of Rubisol) of the epilamated parts. Contact angles: The effectiveness of the epilam agent is evaluated by depositing drops of 2 lubricants: MOEBIUS Testôl 3 oil and 9010. For each lubricant and each epilam agent, the contact angles between the substrates and the lubricants were measured on an OCA type Dataphysics device. Results: The different substrates are epilamated with the epilam agent of Example 1. Then the substrates are washed with 3 watchmaking washes. For comparison, different substrates are epilamated: - either with Moebius® Fixodrop® FK / BS (among the most used epilâmes on the market) CH 710 889 B1 - either with the epilam agent M51 below, described in publication WO 2014/009 058 followed by 3 watch washings. [0054] Polymer M51

The epilame agent M51 is known as one of the epilame agents best resistant to horological washing. Drops of Testöl 3 oil, respectively 9010 oil, are deposited on each epilam substrate and the contact angles between the substrates and the lubricants are measured. The results are shown in the tables below which report the values of the measured contact angles: Table 1: Contact angles measured with MOEBIUS 9010 oil substratum Epilam agent Sapphire Steel Nickel rhodium Gold polyoxymethylene Hostaform® from Celanese Example 1 (inv.) 83 82 74 80 83 73 Μ 51 (comp.) 75 44 46 41 59 * Fixodrop® (comp.) 45 50 41 36 40 35 CH 710 889 B1 Table 2: Contact angles measured with MOEBIUS Testöl 3 oil substratum Epilam agent Sapphire Steel Nickel rhodium Gold POM Hostaform® Example 1 (inv.) 65 62 57 63 61 57 Μ 51 (comp.) 60 34 37 36 47 · * Fixodrop® (Comp.) 34 32 29 24 33 30 Conclusion: The above results show that the contact angles obtained after three horological washes with the two oils (Testöl 3 and 9010) are much higher for the epilamous substrates according to the invention compared to the epilamous substrate by a known epilame agent . The epilame effect after three watch washes is therefore much greater with the epilate substrates according to the present invention. This demonstrates that the epilate substrates according to the invention have better resistance to washing, whatever their nature. claims 1. Substrate comprising a surface at least part of which is covered with an epilam agent, characterized in that said epilam agent comprises at least one compound in the form of a block copolymer comprising at least one block of Μ units associated by covalent bonds by their main chains, and at least one block of N units associated by covalent bonds by their main chains, said blocks being interconnected by covalent bonds by their main chains in linear sequences, where

where Ri, R _2, identical or different, are H, alkyl Οη-C ₁₀ alkenyl, Οη-C _10, and preferably H, CH _3; Y, X, identical or different, are spacer arms consisting of a heteroatom or of a hydrocarbon chain which may contain at least one heteroatom, linear or branched, comprising at least one carbon atom; A, identical or different, constitutes an anchoring group to the substrate, and is chosen from thiols, thioethers, thioesters, sulfides, thioamides, silanols, alkoxysilanes, silane halides, hydroxyls, phosphates, protected or unprotected phosphonic acids, protected phosphonates or not, amines, ammoniums, nitrogen heterocycles, carboxylic acids, anhydrides, catechol; L, identical or different, is a halogenated C ₁ -C ₂₀ carbon group, preferably fluorinated. 2. Substrate according to claim 1, characterized in that at least one of the block of units Μ and of the block of units N comprises at least one unit

R ₃ , identical or different, being H, a C1-C10 alkyl group, C1-C10 alkenyl, and preferably H, CH ₃ ; R ₄ , identical or different, is H, CH ₃ , a hydrocarbon chain which may contain at least one heteroatom, linear or branched, saturated or unsaturated, comprising at least 2 carbon atoms. CH 710 889 B1 3. Substrate according to one of the preceding claims, characterized in that Y, X, identical or different, are chosen from C ₁ -C ₂ o, preferably C ₂ -C ₁₀ ester groups, amide groups, and groups derived from styrene. 4. Substrate according to one of the preceding claims, characterized in that the unit block Μ comprises at least two different groups A. 5. Substrate according to one of the preceding claims, characterized in that L is a carbon group C ₂ -C ₂ o, preferably C ₄ -C ₁₀ . 6. Substrate according to one of the preceding claims, characterized in that L is an at least partially fluorinated group, preferably completely fluorinated. 7. Substrate according to one of the preceding claims, characterized in that the block copolymer comprises between 0.1% and 50%, preferably between 5% and 30% of Μ units, between 1% and 99.9%, preferably between 50 % and 99.9% of N units, and between 0% and 50%, preferably between 0% and 30% of P units. 8. Substrate according to one of the preceding claims, characterized in that the block copolymer comprises between 10 and 350 units. 9. Substrate according to one of the preceding claims, characterized in that its surface at least part of which is covered with the epilam agent is made of a material chosen from metals, metal oxides, silicon, silicon oxides , silicon nitrides, silicon carbides, and their alloys, DLC commonly known as Diamond Like Carbon, polymers, sapphire, ruby. 10. A method of epilamating at least part of a surface of a substrate comprising the steps of: a) preparation of an epilam agent comprising at least one block copolymer as defined in claims 1 to 8 b) optionally, preparation of the substrate surface c) bringing the substrate surface into contact with the epilam agent d) drying. 11. depilamation method according to claim 10, characterized in that the preparation of the epilam agent is carried out by controlled radical copolymerization in block of monomers capable of forming at least one block of Μ units and of monomers capable of forming at minus one block of N units. 12. A method of epilamating according to claim 11, characterized in that at least one of the block of units du and of the block of units N comprises at least one unit P and in that the block copolymerization of the monomers able to form at least one block of Μ units or at least one block of N units is carried out in the presence of monomers capable of forming at least one P unit. 13. depilamation method according to one of claims 10 to 12, characterized in that it further comprises, after step c), a step e) of additional crosslinking. 14. depilamation process according to one of claims 10 to 13, characterized in that the monomers are chosen from acrylates, methacrylates, acrylamides, methacrylamides, vinyl and styrenic monomers. 15. Use of a block copolymer comprising at least one block of Μ units associated by covalent bonds by their main chains, at least one block of N units associated by covalent bonds by their main chains, at least one of the block of Μ units and of the block of N units optionally comprising at least one P unit, associated by covalent bonds by their main chains, said blocks being connected to each other by covalent bonds by their main chains in linear sequences where

where Ri, R ₂ , R ₃ , identical or different, are H, a C1-C10 alkyl group, C1-C10 alkenyl, and preferably H, CH ₃ ; Y, X, identical or different, are spacer arms consisting of a heteroatom or of a hydrocarbon chain which may contain at least one heteroatom, linear or branched, comprising at least one carbon atom; A, identical or different, constitutes an anchoring group to the substrate, and is chosen from thiols, thioethers, thioesters, sulfides, thioamides, silanols, alkoxysilanes, silane halides, hydroxyls, phosphates, protected or unprotected phosphonic acids, protected phosphonates or not, amines, ammoniums, nitrogen heterocycles, carboxylic acids, anhydrides, catechol; L, identical or different, is a halogenated C- | -C ₂₀ carbon group, preferably fluorinated; CH 710 889 B1 FL, identical or different, is H, CH ₃ , a hydrocarbon chain which can contain at least one heteroatom, linear or branched, saturated or unsaturated, comprising at least 2 carbon atoms, as an epilam agent of at least part of a surface of a substrate. 16. Timepiece or jewelry comprising an element comprising a substrate according to any one of claims 1 to 9.