CH710889A2 - 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, X, the same or different, are spacer arms consisting of a heteroatom or a hydrocarbon 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 selected from the group comprising thiols, thioethers, thioes ters, sulphides, thioamides, silanols, alkoxysilanes, silane halides, hydroxyls, phosphates, protected or unsubstituted phosphonic acids, protected or non-protected phosphonates, amines, ammoniums, nitrogenous heterocycles, carboxylic acids, anhydrides, catechol L, identical or different, is a halogenated C 1 -C 20 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

Field of the invention

[0001] 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 piece of timepiece or jewelry comprising a surface covered at least partially with an epilame agent. It also relates to a process for epilamating such a substrate, as well as a timepiece or jewelry piece comprising an element comprising such a substrate.

Background of the invention

[0002] There are various methods for modifying the surface finish 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 at means of an epilame agent in order to control and reduce the surface energy of said surface during its use. More particularly, an epilame agent aims to prevent the spreading of oils or lubricants on the elements of a timepiece or jewelry piece by forming a hydrophobic and lipophobic surface allowing the lubricant to remain in a predetermined location of the treated surface.

[0003] However, the substances currently used for hair removal have different drawbacks. More specifically, known epilame agents, such as Fixodrop <®> FK / BS from Moebius <®> or the Fluorad ™ range from 3M ™, exhibit poor resistance to watch washes. Patent application US 2012/0 088 099 partially solves this problem by proposing to use an epilame agent carrying a catechol function at the end of the chain, this catechol function being able to bind itself firmly to the surface of the substrates. However, the resistance to watch washings of these epilame agents has not been improved on all substrates, in particular on gold and steel, which are very frequent substrates in the field of watchmaking and jewelry. Thus, the use of known epilame agents is generally limited to certain materials, which requires the user to have at his disposal different types of epilame agents depending on the nature of the surfaces to be treated. A solution for solving this problem is described for example in application WO 2012/085 130. This solution consists in using as epilam composition a mixture of compounds of different nature (thiol and bisphosphonic) whose synergistic effect promotes the adhesion of the epilame. epilame on the substrate. However, the synthesis of each of these compounds requires at least four steps, so the synthetic process for the entire epilam composition is long and complex.

Summary of the invention

[0004] The object of the invention is in particular to overcome the various drawbacks of known epilame agents.

[0005] More specifically, an objective of the invention is to provide an epilame agent offering increased resistance to washing compared to known epilame agents.

[0006] The invention also aims to provide a universal epilame agent which can be used for any type of material.

[0007] The invention also aims to provide an epilame agent which is simple to manufacture in a few steps.

[0008] To this end, the present invention relates to a substrate comprising a surface of which at least a part is covered with an epilame agent.

[0009] According to the invention, said epilame agent comprises at least one compound in the form of a block copolymer comprising at least one block of M units associated by covalent bonds via 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

where R1, R2, identical or different, are H, C1 – C10 alkyl, C1 – C10 alkenyl, and preferably H, CH3 Y, X, identical or different, are spacer arms made up 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, sulphides, thioamides, silanols, alkoxysilanes, silane halides, hydroxyls, phosphates, phosphonic acids, protected or not , phosphonates, protected or not, amines, ammoniums, nitrogenous heterocycles, carboxylic acids, anhydrides, catechol L, identical or different, is a C1 – C20 halogenated carbon group, preferably fluorinated.

[0010] Such an epilame 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 method of epilamating at least part of a surface of a substrate comprising the steps of: a) preparation of an epilame agent comprising at least one block copolymer as defined herein above b) optionally, preparation of the surface of the substrate c) bringing the surface of the substrate into contact with the epilame agent d) drying.

The present invention also relates to the use of a block copolymer comprising at least one block of M units associated by covalent bonds via their main chains, at least one block of N units associated with covalent bonds via their main chains. , at least one of the block of units M 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 R1, R2, R3, identical or different, are H, C1 – C10 alkyl, C1 – C10 alkenyl, and preferably H, CH3 Y, X, identical or different, are spacer arms made up 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, sulphides, thioamides, silanols, alkoxysilanes, silane halides, hydroxyls, phosphates, phosphonic acids, protected or not , phosphonates, protected or not, amines, ammoniums, nitrogenous heterocyciae, carboxylic acids, anhydrides, catechol L, identical or different, is a halogenated C1 – C20 carbon group, preferably fluorinated R4, identical or different, is H, CH3, a hydrocarbon chain which may contain at least one heteroatom, linear or branched, saturated or unsaturated, comprising at least 2 carbon atoms, as epilame agent of at least part of a surface a substrate, in particular intended for watchmaking or jewelry.

[0013] The present invention also relates to a timepiece or piece of jewelry comprising an element comprising a substrate as defined above.

Detailed description of the invention

According to the present invention, a substrate, in particular a substrate of an element of a timepiece or jewelry, comprises a surface at least part of which is covered with an epilame agent, said epilame agent comprising at least one compound in the form of a block copolymer comprising at least one block of M units associated by covalent bonds via their main chains, and at least one block of N units associated with covalent bonds via their main chains, at least one of the block of units M 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, or

where R1, R2, R3, identical or different, are H, C1 – C10 alkyl, C1 – C10 alkenyl, and preferably H, CH3 Y, X, identical or different, are spacer arms made up 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, sulphides, thioamides, silanols, alkoxysilanes, silane halides, hydroxyls, phosphates, phosphonic acids, protected or not , phosphonates, protected or not, 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 R4, identical or different, is H, CH3, a hydrocarbon chain which may contain at least one heteroatom, linear or branched, saturated or unsaturated, comprising at least 2 carbon atoms.

[0015] Preferably, the block copolymer comprises at least one block of M units associated by covalent bonds via their main chains, and at least one block of N units associated with covalent bonds via their main chains, at least one the block of units M and the block of units N optionally comprising at least one unit P, associated by covalent bonds via their main chains, said blocks being connected to each other by covalent bonds via their main chains in linear sequences, where

where R1, R2, R3, identical or different, are H, C1 – C10 alkyl, C1 – C10 alkenyl, and preferably H, CH3, Y, X, identical or different, are spacer arms made up 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, sulphides, thioamides, silanols, alkoxysilanes, silane halides, hydroxyls, phosphates, phosphonic acids, protected or not , phosphonates, protected or not, 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 R4, identical or different, is H, CH3, 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 comprises or consists only of blocks of M units and of blocks of N units, at least one of the block of M units and of the block of N units comprising optionally at least one P.

The blocks of M units and N units, which optionally include 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 as the form:

Preferably, the block copolymer comprises a single block of M units and a single block of N units, at least one of the block of M units and of the block of N units optionally comprising at least one unit. P. When present, the number z of P units in the M unit block may vary from the w number of P units in the N unit block.

Preferably, the P units are integrated and distributed within the block composed of N units, for example by statistical copolymerization of P units with N units to form a single block consisting mainly of N units and assimilated to a unit block N.

Advantageously, the Y, X groups, which are identical or different, are chosen from the group comprising ester groups in C1 – C20, preferably C2 – C10, more preferably C2 – C6, and even more preferably C2 – C5, preferably alkyl ester groups, preferably linear, amide groups, and groups derived from styrene.

[0021] The functional groups of interest A are capable of reacting with the surface of the substrate to be epilamated, so as to constitute anchoring groups of the epilame agent on the surface of the substrate. Advantageously, groups A can also be provided at the end of the block of M units.

[0022] Advantageously, the unit block M comprises at least two different A groups.

[0023] The functional groups of L interest are responsible for the epilame effect. They comprise at least one halogen atom, preferably a fluorine atom. Preferably, L is a C2 – C20, preferably C4 – C10, and more preferably C6 – C9, carbon group. L is partially or totally halogenated. Advantageously, L is an at least partially fluorinated, and preferably fully fluorinated, group. L can also have a hydrogen atom on the terminal group.

[0024] The functional groups of interest R4 of the P units are used to modify the properties of the epilame agent and / or to provide other functions. For example, R4 can be an alkyl chain used to modify the contact angle obtained or a chain capable of constituting crosslinking points during an additional crosslinking step (step e). Obviously, R4 present in unit block M may be different from R4 present in unit block N.

Preferably, the block copolymer comprises between 0.1% and 50%, preferably between 5% and 30%, and more preferably between 5% and 20% of M 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).

[0026] Advantageously, the block copolymer comprises between 10 and 350 units (x + y + z + w).

In a particularly advantageous manner, the units M, N, P are chosen to carry several A groups of different nature, several L groups, preferably of the same nature, and optionally one or more R4 groups which may be identical or of different nature, so as to refine and improve the properties of the epilame agent, in order to obtain more specifically an epilame agent that is universal and exhibits improved affinity with the substrate.

Preferably, the surface of the substrate of which at least a part is covered with the epilame agent is made of a material chosen from the group comprising metals, metal oxides, doped or not, polymers, sapphire, ruby, silicon, silicon oxides, silicon nitrides, silicon carbides, DLC (Diamond Like Carbon), and their alloys.

More specifically, 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, or polyoxymethylene or acrylamide, as well as their alloys.

The present invention also relates to a method of epilamating at least part of a surface of a substrate comprising the steps of: a) preparing an epilame agent comprising at least one block copolymer as defined herein above b) optionally, preparation of the surface of the substrate, in particular by cleaning according to standard horological processes, c) bringing the surface of the substrate into contact with the epilame agent d) drying.

Preferably, the preparation of the epilame agent is carried out by block copolymerization of monomers capable of forming at least one block of M units and of monomers capable of forming at least one block of N units, the copolymerization in block of monomers capable of forming at least one block of M units or at least one block of N units optionally carried out with monomers capable of forming at least one P unit.

[0032] 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: of monomers capable of forming at least one block of M units and optionally with monomers capable of forming at least one P unit with 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 transfer by addition-fragmentation (RAFT), in solution or in emulsion.

According to 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 R4, followed by the copolymerization, preferably controlled radical. , of monomers carrying the side chains X – L with optionally monomers carrying the side chains R4, R4 identical or different.

According to another variant, the block copolymer can be obtained by polymerization, preferably controlled radical, of monomers carrying the appropriate Y side chains with optionally monomers bearing side chains intended to carry R4, followed by the copolymerization, preferably controlled radical, of monomers carrying the appropriate side chains X with optionally monomers carrying side chains intended to carry R4, then the side chains are modified, for example by "click chemistry", to introduce therein the functional groups of interest A, L and groups R4.

Preferably, the monomers are chosen from the group comprising acrylate, methacrylate, acrylamide, methacrylamide, vinyl, diene, styrene 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 synthetic step.

Particularly preferred monomers are:

[0039] Thus, the copolymer used as epilame agent can be easily obtained in a limited number of steps from marketed products.

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):

[0042] 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 an epilame agent solution, which will be used for the treatment of 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 appropriate functional groups of interest provided. on the R4 side chains of the P units.

[0044] The substrate according to the invention has a surface covered with an epilame agent which is simple and economical to synthesize, exhibiting an affinity with any type of substrate and an improved resistance to washing compared to known epilame agents. An element or part having a substrate in accordance with the invention can be used in all types of applications in the mechanical field, and more particularly in precision mechanics, and in particular watchmaking and jewelry.

[0045] The following examples illustrate the present invention without, however, limiting its scope.

Example 1

An epilame agent is synthesized in the form of a block copolymer by controlled radical polymerization of: 1 H, 1 H, 2 H, 2 H-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: in a Schlenk tube containing cyclohexanone (1 mL) and 2 mL of Novec ™ hydrofluoroether HFE-7200 (3M ™) previously degassed with nitrogen, are added the RAFT agent (42 μL) and the 1 H, 1 H , 2H, 2H-Perfluorodecylacrylate. 0.2 mL of a 0.122 mol / 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 as a yellowish powder. The polymer obtained above is dissolved in cyclohexanone (1 mL) and 2 mL of Novec ™ hydrofluoroether HFE-7200 (3M ™) degassed beforehand with nitrogen, then 3-acryloxopropyl methyldimethoxysilane (211 µl) and 3-acryloxopropyl methyl thioether (154 µL) are added. 0.2 mL of a 0.122 mol / L solution of AIBN 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

Procedures used

Preparation of substrates

Before the epilame treatment, substrates of different types are cleaned by standard watchmaking processes. More specifically, the parts are cleaned with a solution of Rubisol in the presence of ultrasound, rinsed 3 times with isopropyl alcohol, and then dried in hot air.

Epilame treatment of substrates

The substrates are epilamated by immersion (approximately 5 min) in a solution of the epilame agent (solvent: Vertrel <®> Suprion ™ from DuPont ™ at 250 mg / L) then drying in hot air.

Resistance to washing

The resistance to washing of epilame agents is evaluated after 3 successive washes (standard watch wash with a solution of Rubisol) of the epilamated parts.

Contact angles

The effectiveness of the epilame agent is evaluated by depositing drops of 2 lubricants: MOEBIUS Testôl 3 and 9010 oil. For each lubricant and each epilame agent, the contact angles between the substrates and the lubricants were measured on a Dataphysics device of the OCA type.

Results

The various substrates are epilamated with the epilame agent of Example 1. Then the substrates are washed with 3 clock washes.

For comparison, different substrates are epilamated: either with Fixodrop® FK / BS from Moebius® (among the most widely used epilames on the market) or with the epilame agent M51 below, described in publication WO 2014/009 058 followed by 3 watch washes.

[0054] The epilame agent M51 is known to be one of the epilame agents best resistant to watch washings.

[0055] Drops of Testôl 3 oil, respectively 9010 oil, are deposited on each epilame 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 contact angles measured:

Table 1

[0057]

Table 2

[0058]

Conclusion

The above results show that the contact angles obtained after three clock washings with the two oils (Test6l 3 and 9010) are much higher for the epilamated substrates according to the invention compared to the epilamated substrate with a known epilame agent . The epilame effect after three watch washes is therefore much greater with the epilamated substrates according to the present invention. This demonstrates that the epilamated substrates according to the invention exhibit better resistance to washing, whatever their nature.

Claims (16)

1. Substrate comprising a surface of which at least a part is covered with an epilame agent, characterized in that said epilame agent comprises at least one compound in the form of a block copolymer comprising at least one block of M units associated with 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 connected to each other by covalent bonds by their main chains in linear sequences, where where R1, R2, identical or different, are H, C1 – C10 alkyl, C1 – C10 alkenyl, and preferably H, CH3 Y, X, identical or different, are spacer arms made up 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, sulphides, thioamides, silanols, alkoxysilanes, silane halides, hydroxyls, phosphates, phosphonic acids, protected or not , phosphonates, protected or not, amines, ammoniums, nitrogenous heterocycles, carboxylic acids, anhydrides, catechol L, identical or different, is a C1 – C20 halogenated carbon group, preferably fluorinated. 2. Substrate according to claim 1, characterized in that at least one of the unit block M and the unit block N comprises at least one unit P, where P is R3, the same or different, being H, C1 – C10 alkyl, C1 – C10 alkenyl, and preferably H, CH3 R4, identical or different, is H, CH3, a hydrocarbon chain which may contain at least one heteroatom, linear or branched, saturated or unsaturated, comprising at least 2 carbon atoms. 3. Substrate according to one of the preceding claims, characterized in that Y, X, identical or different, are chosen from the group comprising ester groups in C1 – C20, preferably in C2-C10, amide groups, and groups derived from styrene. 4. Substrate according to one of the preceding claims, characterized in that the block of units M comprises at least two different groups A. 5. Substrate according to one of the preceding claims, characterized in that L is a carbon group in C2 – C20, preferably C4 – C10. 6. Substrate according to one of the preceding claims, characterized in that L is an at least partially fluorinated, preferably fully fluorinated, group. 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 M 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 of which at least a part is covered with the epilame agent is made of a material chosen from the group comprising metals, metal oxides, polymers, sapphire, ruby, silicon, silicon oxides, silicon nitrides, silicon carbides, DLC (Diamond Like Carbon), and their alloys. 10. A method of epilamating at least part of a surface of a substrate comprising the steps of: a) preparation of an epilame agent comprising at least one block copolymer as defined in claims 1 to 8 b) optionally, preparation of the substrate surface c) contacting the surface of the substrate with the epilame agent d) drying. 11. Epilamage process according to claim 10, characterized in that the preparation of the epilame agent is carried out by block copolymerization of monomers capable of forming at least one block of M units and of monomers capable of forming at least one. unit block N. 12. Epilamage method according to claim 11, characterized in that at least one of the block of units M and of the block of N units comprises at least one unit P and in that the block copolymerization of the monomers capable of forming at least one block of M 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. A hair removal process according to one of claims 10 to 12, characterized in that it further comprises, after step c), a step e) of additional crosslinking. 14. A method of depilamation according to one of claims 10 to 13, characterized in that the monomers are chosen from the group comprising acrylate, methacrylate, acrylamide, methacrylamide, vinyl and styrene monomers. 15. Use of a block copolymer comprising at least one block of M units associated by covalent bonds via their main chains, at least one block of N units associated with covalent bonds via their main chains, at least one of the block of units M 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 R1, R2, R3, identical or different, are H, C1 – C10 alkyl, C1 – C10 alkenyl, and preferably H, CH3 Y, X, identical or different, are spacer arms made up 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, sulphides, thioamides, silanols, alkoxysilanes, silane halides, hydroxyls, phosphates, phosphonic acids, protected or not , phosphonates, protected or not, amines, ammoniums, nitrogenous heterocycles, carboxylic acids, anhydrides, catechol L, identical or different, is a halogenated C1 – C20 carbon group, preferably fluorinated R4, identical or different, is H, CH3, a hydrocarbon chain which may contain at least one heteroatom, linear or branched, saturated or unsaturated, comprising at least 2 carbon atoms, as epilame agent of at least part of a surface of a substrate. 16. Piece of timepiece or jewelry comprising an element comprising a substrate according to any one of claims 1 to 9.