Articles made of mineral composite materials and methods of making same

Abstract

One aspect of the invention relates to an article made of a composite material comprising, by weight:-one or more thermoplastic resins that are at least partially bio-based, the total percentage of the one or more thermoplastic resins being 20% to 74.9%,-a mineral filler, the mineral filler being a mineral filler, the mineral filler being a mineral filler, the mineral filler being a mineral filler, the mineral filler being a mineral filler, and the mineral filler being a mineral filler. The invention relates to a mineral filler composition comprising a shell-based mineral material and a porous silica-based mineral material derived from a diatom skeleton, the percentage of mineral filler being from 25% to 79.9%,-a dispersant, the percentage by weight of which is from 0.1% to 5%, preferably from 0.1% to 1%,-optionally a coloring system, the percentage of which is from 0% to 5%,-optionally a reinforcing material, the percentage of which is from 0% to 8%,-optionally a coupling agent, the percentage of which is from 0% to 5%, and the percentage of which is from 0% to 8%. The percentage of the components is 0-5%. Another aspect of the invention relates to a method of manufacturing the article.

Description

Technical Field

[0001] The present invention relates to a composite material comprising at least one bio-based resin and a mineral filler. Technical Background

[0002] So-called bioceramic materials are known in the prior art. These materials involve mixing a partially bio-based resin (e.g., polyamide 11 with a bio-based content of more than 50%) with a ceramic (e.g., yttria-stabilized zirconia (YSZ)). The known advantages of such composite materials are:

[0003] - Colorability using traditional coloring systems,

[0004] - Due to the inherent density of zirconia being 4.5 g / cm 3 , the density of the molded component increases,

[0005] - Due to the inherent thermal conductivity of zirconia being 2.5 W.m -1 .K -1 , the thermal conductivity of the molded component increases.

[0006] The disadvantages of such bioceramic materials are that a large proportion of fossil resources are used in the resin and the ceramic, and since bacteria are generated on the surface when wearing the material and these bacteria feed on organic residues, unpleasant odors may be produced. This is because the materials present in the composite do not have significant antibacterial activity. Summary of the Invention

[0007] The present invention aims to develop a new type of mineral composite material to overcome the disadvantages of bioceramic materials in the prior art. This new material must have the lowest possible ecological impact, have the best comfort when in contact with the skin, allow heat to dissipate at the skin-wrist interface, and be odor-proof.

[0008] The composite material comprises one or more thermoplastic resins that are at least partially bio-based. The term "partially" should be understood to mean that one or more resins are bio-based as a whole, with a bio-based content greater than or equal to 60%, preferably greater than or equal to 85%, more preferably greater than or equal to 98%. Instead of the ceramic used in the prior art, the composite material also comprises a mineral material derived from shells, i.e., calcium carbonate (CaCO 3 ), and porous silica derived from diatom skeletons.

[0009] CaCO 3 has a thermal conductivity comparable to that of YSZ, which is 2.5 W.m -1 .K -1 . CaCO 3 has a density of 2.7 g.cm- 3 , while the density of zirconia is 4.5 g.cm-3 , which makes the composite material lighter to wear. Diatomaceous silica has antibacterial properties, which prevent the generation of unpleasant odors. In addition, when mixed with shells, it improves the flow of the powder in the dispenser during the manufacturing process.

[0010] More specifically, the present invention relates to an article made of a composite material, the composite material comprising by weight:

[0011] - one or more at least partially bio-based thermoplastic resins, the total percentage of the one or more thermoplastic resins being 20% to 74.9%,

[0012] - a mineral filler, which comprises a shell-based mineral material and a porous silica-based mineral material derived from the diatom skeleton, the percentage of the mineral filler being 25% to 79.9%,

[0013] - a dispersant, the percentage of which is 0.1% to 5%, preferably 0.1% to 1%,

[0014] - an optional coloring system, the percentage of which is 0% to 5%,

[0015] - an optional reinforcing material, the percentage of which is 0% to 8%,

[0016] - an optional coupling agent, the percentage of which is 0% to 5%.

[0017] The present invention also relates to a method for manufacturing the article, the method comprising the following steps:

[0018] a. Providing a shell-based mineral material and a porous silica-based mineral material derived from the diatom skeleton,

[0019] b. Providing one or more at least partially bio-based thermoplastic resins,

[0020] c. Collecting, sorting, cleaning, crushing and screening the shells, and only retaining the shell particles with a particle size of 100 μm or less,

[0021] d. Mixing the shell particles and the porous silica, and the mixture forms a mineral filler,

[0022] e. Mixing the mineral filler and one or more thermoplastic resins with a dispersant,

[0023] f. Optionally adding a coloring system, a reinforcing material and / or a coupling agent to the mixture obtained in step e,

[0024] g. Molding the mixture obtained in step e or step f to obtain the article. Detailed Description

[0025] The present invention relates to an article made of a composite material, the composite material comprising at least one mainly bio-based thermoplastic resin and calcium carbonate and a porous silica-based mineral material. The article can be, for example, a watch component. More specifically, it can be an external component selected from the following non-exhaustive list, which includes the middle, the case back, the bezel, the crown, the button, the watch link, the bracelet, the tongue buckle, the clasp, the dial, the hands and the dial graduations.

[0026] Based on the total weight of the composite material, the composite material comprises (or consists of):

[0027] -One or more thermoplastic resins, with a total weight percentage of 20% to 74.9%, preferably 50% to 59.9%. The bio-based content of the resin mixture or resin (if it is a single resin) is greater than or equal to 60%, preferably greater than or equal to 85%, more preferably greater than or equal to 98%; the bio-based percentage of the mixture or resin is measured according to standard ASTM D6866-22. One or more thermoplastic resins are selected from polyamide 11 (PA11), polyamide 10 (PA10), polyamide 610 (PA610), polyethylene furanoate (PEF), polyurethane (PU), polyether block amide (PEBA), thermoplastic copolyester elastomer (TPC), thermoplastic polyurethane elastomer (TPU), thermoplastic polyolefin elastomer (TPO), thermoplastic vulcanized elastomer (TPV), and thermoplastic styrene elastomer (TPES). The composite material can be flexible or rigid. In the case of a rigid composite material, the mixture can contain thermoplastic resins selected from polyamide 11 (PA11), polyamide 10 (PA10), polyamide 610 (PA610), and polyethylene furanoate (PEF), and a thermoplastic elastomer resin of the polyurethane (PU) or polyether block amide (PEBA) type to absorb impact force. Therefore, the thermoplastic elastomer resin is present in a weight percentage of 1 to 10% based on the total weight of the resin mixture. The rigid composite material can contain several grades of the same type of thermoelastic resin and several grades of the same type of thermoplastic elastomer resin, such as several PA11 resins with different rheological properties. Preferably, the PA11, PA10, and PEF resins are 98% bio-based, the PA610 resin is 62% bio-based, and the thermoplastic elastomer resin is greater than 40% bio-based, more preferably 98%. In the case of a flexible composite material, only flexible thermoplastic elastomer resins are used. This can be a composite material containing resins selected from PEBA (polyether block amide), TPC (thermoplastic copolyester elastomer), TPU (thermoplastic polyurethane elastomer), TPO (thermoplastic polyolefin elastomer), TPV (thermoplastic vulcanized elastomer), and TPES (thermoplastic styrene elastomer). As described above, it can be a resin containing several grades of this type of resin (and thus having different rheological properties). Preferably, it is a resin or a mixture of resins of the same type selected from TPU, TPC, and PEBA,

[0028] -Mineral fillers, which contain calcium carbonate (CaCO 3 )-based mineral materials and porous silica-based mineral materials, with a total weight percentage of 25% to 79.9%, preferably 40% to 49.9%. CaCO 3The base mineral material is derived from shellfish, more precisely from shellfish production waste. Preferably, these are scallop and / or oyster shells, as they have a lighter natural color. Their particle size is less than or equal to 100 μm, preferably less than or equal to 20 μm, and the particle size is measured using laser diffraction (ISO 13320-1(2009)). The porous silica is derived from diatom skeletons. These are single-celled microalgae with a silica skeleton. The porous silica in the diatom skeletons is cultivated and thus renewable. The weight percentage of the porous silica is 2% to 20% of the total weight of the mineral filler. The microporous silica can be doped with silver ions or other antibacterial additives, such as gold microparticles or copper oxide microparticles, to increase its antibacterial effect tenfold.

[0029] - A dispersant, with a weight percentage of 0.1% to 5%, preferably 0.1% to 1%. It can be a natural wax, paraffin, surfactant, etc.

[0030] - An optional coloring system, with a weight percentage of 0% to 5%. For example, the coloring system can be formed by one or more bio-based resins concentrated with natural coloring materials, such as PA11 resin or PA10 resin. Optionally, the coloring system can contain mineral materials from shells, which have a size fraction or a combination of different size fractions obtained by sieving; the average size of these different fractions is relatively high, from 100 to 500 μm. This enables the visualization of shell particles when seeking a specific aesthetic effect. The mineral material can be the above-mentioned scallop and oyster shells, or other types of shellfish, such as mussels, in which case larger particles are selected. The percentage of this mineral material in the coloring system can be 1% to 10% based on the total weight of the coloring system, or 0% to 0.3%, with an upper limit of 10%.

[0031] - An optional reinforcing material, with a weight percentage of 0% to 8%. The reinforcing material can exist in various forms, such as in the form of fibers or particles. For example, it can be metal fibers, mineral fibers, or organic fibers of plant or non-plant origin. For example, calcium alginate fibers from seaweed may be preferred. Alternatively, carbon fibers, glass fibers, or glass beads can be used, etc.

[0032] - An optional coupling agent to optimize the interface between the mineral filler, any reinforcing material, and the resin mixture. The weight percentage of this coupling agent can be 0% to 5%. For example, it can be a copolymer of ethylene and acrylic acid. It can also be a copolymer of ethylene-vinyl acetate and acrylic acid.

[0033] The present invention also relates to a method for manufacturing the above-mentioned article, including the following steps:

[0034] - Providing shells and porous silica derived from diatom skeletons,

[0035] - Provide one or more bio-based thermoplastic resins. Preferably, the melt volume rate of the one or more thermoplastic resins is less than 30 cm 3 / 10 min,

[0036] - Collect, sort, clean, crush, and screen the shells to retain particles with a particle size less than or equal to 100 μm, preferably less than or equal to 20 μm,

[0037] - Mix the shell particles and porous silica, and the mixture forms a mineral filler,

[0038] - Mix the mineral filler, one or more thermoplastic resins, and a dispersant,

[0039] - Optionally add a coloring system, a reinforcing material, and / or a coupling agent to the mixture obtained from the mineral filler, one or more thermoplastic resins, and the dispersant,

[0040] - Mold the mixture of the mineral filler, one or more thermoplastic resins, the dispersant, and any additives to obtain the article.

[0041] The molding can be carried out by injection molding after a prior compounding step of twin-screw extrusion and granulation. Alternatively, the manufacturing method can be carried out by extrusion.

[0042] Before crushing, the shells are sorted manually or automatically according to color. Cleaning can be carried out by physicochemical cleaning, using mechanical actions such as brushing in an alkaline solution such as bleach to remove organic matter.

[0043] Preferably, shell particles of different particle sizes are mixed to have a wider particle size distribution or a multimodal particle size distribution to improve the compactness of the filler and be able to fill the resin system at a level greater than or equal to 40 wt%. For example, a 100% fraction screened at 10 μm can be combined with a 50% fraction screened at 20 μm and a 10% fraction screened at 100 μm. The fraction with a larger particle size can be optionally recycled for the coloring system to obtain a specific aesthetic appearance.

Claims

1. An article made of a composite material, the composite material comprising by weight: - one or more thermoplastic resins at least partly bio-based, the total percentage of said one or more thermoplastic resins being between 20% and 74.9%, - a mineral filler comprising a shell-based mineral material and a porous silica-based mineral material derived from the skeleton of diatoms, the percentage of said mineral filler being between 25% and 79.9%, - a dispersant in an amount of 0.1 to 5% by weight, - an optional coloring system in a percentage ranging from 0% to 5%, - optional reinforcement materials, in percentages ranging from 0% to 8%, - Optional coupling agent, in a percentage ranging from 0% to 5%.

2. The article according to claim 1, characterized in that The one or more thermoplastic resins are bio-based in their entirety, with a bio-based fraction greater than or equal to 60%, measured according to standard ASTM D6866-22.

3. The article according to claim 1 or 2, characterized in that The one or more thermoplastic resins are selected from polyamide 11, polyamide 10, polyamide 610, polyethylene furanoate, polyurethane, polyether block amide, thermoplastic copolyester elastomer, thermoplastic polyurethane elastomer, thermoplastic polyolefin elastomer, thermoplastic vulcanizate elastomer and thermoplastic styrene elastomer.

4. The article according to claim 3, characterized in that For the rigid composite material, it comprises a thermoplastic resin selected from a first list consisting of polyamide 11, polyamide 10, polyamide 610 and polyethylene furanoate and a thermoplastic elastomer resin selected from a second list consisting of polyurethane and polyether block amide, or it comprises several resins of the same type selected from the first and second lists.

5. The article according to claim 3, characterized in that For the flexible composite material, it comprises a thermoplastic elastomer resin selected from the list consisting of polyether block amides, thermoplastic copolyester elastomers, thermoplastic polyurethane elastomers, thermoplastic polyolefin elastomers, thermoplastic vulcanizates and thermoplastic styrene elastomers, or it comprises several resins of the same type selected from said list.

6. The article according to claim 1 or 2, characterized in that The weight percentage of the mineral filler is 40% to 49.9%, and the total weight percentage of the one or more thermoplastic resins is 50% to 59.9%.

7. The article according to claim 1 or 2, characterized in that The weight percentage of porous silica is 2% to 20% of the weight of the mineral filler.

8. The article according to claim 1 or 2, characterized in that The porous silica is doped with one or more antimicrobial additives.

9. The article according to claim 8, characterized in that The one or more antimicrobial additives are selected from the group consisting of silver ions, gold particles, and copper oxide particles.

10. The article according to claim 1 or 2, characterized in that The particle size of the shell-based mineral material is less than or equal to 100 μm.

11. The article according to claim 1 or 2, characterized in that The coloring system also comprises a shell-based mineral material, the particle size of which is between 100 μm and 500 μm.

12. The article according to claim 11, characterized in that The mineral material is present in an amount of 1 to 10% by weight based on the coloring system.

13. Method for manufacturing an article according to any one of the preceding claims, comprising the steps of: a. Providing shell-based mineral materials and porous silica-based mineral materials derived from diatom skeletons, b. providing one or more thermoplastic resins that are at least partially bio-based, c. Collect, sort, clean, crush and sieve shells, retaining only shell particles with a size of 100 μm or less, d. Mixing the shell particles and porous silica, the mixture forms a mineral filler, e. mixing a mineral filler and one or more thermoplastic resins with a dispersant, f. optionally adding a coloring system, a reinforcing material and / or a coupling agent to the mixture obtained in step e, g. shaping the mixture obtained in step e or step f to obtain the article.

14. The method according to claim 13, characterized in that The melt volume velocity of the one or more thermoplastic resins is less than 30 cm 3 / 10 minutes.

15. The method according to claim 13 or 14, characterized in that In step d, shell particles of different sizes are mixed to increase the density of the mineral filler.

16. The method according to claim 13 or 14, characterized in that Cleaning is carried out by mechanical action in an alkaline solution before comminution.

17. The method according to claim 13 or 14, characterized in that The shaping step g is performed by injection molding or extrusion.