Article made of mineral composite material, and method for manufacturing the same

Abstract

To provide an article made of a mineral composite material, and a method for manufacturing the same.SOLUTION: A composite material comprises 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 between 20% and 74.9%; a mineral filler having a seashell-based mineral material and a porous silica-based mineral material derived from diatom skeletons, a percentage of the mineral filler being between 25% and 79.9%; and a dispersant, a percentage of the dispersant being between 0.1% and 5%; optionally a stain system, a percentage of the stain system being between 0% and 5%; optionally a reinforcing material, a percentage of the reinforcing material being between 0% and 8%; and / or optionally a coupling agent, a percentage of the coupling agent being between 0% and 5%.SELECTED DRAWING: None

Description

Technical Field

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

Background Art

[0002] So-called bioceramic materials are known in the prior art. These include the mixing of a partially bio-based resin such as polyamide 11, more than 50% of which is bio-based, and a ceramic such as yttria-stabilized zirconia (YSZ). Known advantages of such composite materials are - Colorability using conventional dyeing systems, - Increase in the density of molded parts due to the density of zirconia of 4.5 g / cm 3 Increase in the density of molded parts due to - Increase in the thermal conductivity of molded parts due to the thermal conductivity of zirconia of 2.5 W·m -1 ·K -1 Increase in the thermal conductivity of molded parts due to is.

[0003] The disadvantages of this bioceramic material are that a large amount of fossil resources are used in the resin and the ceramic, and when worn, an unpleasant odor may be generated by bacteria that form on the material surface and feed on organic residues. This is because the materials present in the described composite materials do not have significant antibacterial activity.

Summary of the Invention

[0004] The present invention consists of developing a new mineral composite material to overcome the disadvantages of the prior art bioceramic materials. This new material should have as little ecological impact as possible, be optimized for comfort when in contact with the skin, be able to dissipate heat at the skin-wrist interface, and must be anti-odour.

[0005] The composite material comprises one or more thermoplastic resins that are at least partially bio-based. The term "partially" is understood to mean that the one or more resins are bio-based by 60% or more, preferably 85% or more, more preferably 98% or more, in total. Instead of the ceramics used in the prior art, the composite material further comprises a mineral material derived from shells, namely calcium carbonate (CaCO 3 ), and porous silica derived from diatom skeletons.

[0006] CaCO 3 has a thermal conductivity equivalent to that of YSZ of 2.5 W·m -1 ·K -1 . The density of CaCO 3 is 2.7 g·cm -3 , which makes the wearing of the composite material lighter compared to 4.5 g·cm -3 of zirconia. Diatomaceous silica has antibacterial properties that prevent the generation of unpleasant odors. Also, when mixed with shells, it improves the flow of the powder in the dispenser during the manufacturing process.

[0007] More specifically, the present invention relates to an article made of a composite material comprising the following by weight. - One or more thermoplastic resins that are at least partially bio-based, wherein the total percentage of the one or more thermoplastic resins is 20% - 74.9%, one or more thermoplastic resins, - A mineral filler having a shell-based mineral material and a porous silica-based mineral material derived from diatom skeletons, wherein the percentage of the mineral filler is 25% - 79.9%, a mineral filler, - A dispersant, wherein the percentage thereof is 0.1% - 5%, preferably 0.1% - 1%, a dispersant, - Optionally, a stain system, wherein the percentage thereof is 0% - 5%, a stain system, - Optionally, a reinforcement, wherein the percentage thereof is 0% - 8%, a reinforcement, - Optionally, a coupling agent, the percentage of which is 0% to 5%.

[0008] The present invention further relates to a method for manufacturing an article including the following steps. a. Providing a shell-based mineral material and a porous silica-based mineral material derived from diatom skeletons. b. Providing one or more thermoplastic resins that are at least partially bio-based. c. Collecting, sorting, washing, crushing, and sieving the shells to retain only shell particles with a particle size of 100 μm or less. d. Mixing the shell particles and the porous silica to form a mineral filler. e. Mixing the mineral filler and one or more thermoplastic resins with a dispersant. f. Optionally, adding a dyeing system, a reinforcing material, and / or a coupling agent to the mixture obtained in step e. g. Molding the mixture obtained in step e or step f to obtain an article.

DETAILED DESCRIPTION OF THE INVENTION

[0009] The present invention relates to an article made of a composite material including at least one mainly bio-based thermoplastic resin and a mineral material based on calcium carbonate and porous silica. The article can be, for example, a timepeace component. More specifically, it can be an external component selected from the non-exhaustive list including a central part, a back part, a bezel, a crown, a push piece, a bracelet link, a bracelet, a tongue buckle, a clasp, a dial, a hand, and a dial index.

[0010] The composite material includes (or consists of) the following based on the total weight of the composite material. One or more thermoplastic resins that are above - 1, with a total weight percentage of 20% - 74.9%, preferably 50% - 59.9%. When it is a resin mixture or a single resin, the resin is 60% or more, preferably 85% or more, more preferably 98% or more bio - based, and 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 vulcanizate (TPV), and thermoplastic styrene elastomer (TPES). The composite material can be either flexible or rigid. In the case of a rigid composite material, the mixture can include a thermoplastic resin selected from polyamide 11 (PA), polyamide 10 (PA10), polyamide 610 (PA610), and polyethylene furanoate (PEF) to absorb impact, and a thermoplastic elastomer resin of the polyurethane (PU) or polyether block amide (PEBA) type. Thus, the thermoplastic elastomer resin is present in a weight percentage of 1 - 10% based on the total weight of the resin mixture. The rigid composite material can include some grades of the same type of thermoelastic resin and the same type of thermoplastic elastomer resin, for example, some PA11 resins with different rheologies. Preferably, PA11, PA10, and PEF resins are 98% bio - based, PA610 resin is 62% bio - based, and the thermoplastic elastomer resin is more than 40%, more preferably 98% bio - based. In the case of a flexible composite material, only flexible thermoplastic elastomer resins are used.This may be a composite material containing a resin selected from PEBA (polyether block amide), TPC (thermoplastic copolyester elastomer), TPU (thermoplastic polyurethane elastomer), TPO (thermoplastic polyolefin elastomer), TPV (thermoplastic vulcanizate elastomer), and TPES (thermoplastic styrene elastomer). As described above, it may contain resins that are some grades of this type of resin and thus have different rheologies. Preferably, it is a resin or a mixture of resins of the same type selected from TPU, TPC, and PEBA. - Mineral fillers containing 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%. The CaCO 3 -based mineral materials are derived from shellfish, more precisely from shellfish production waste. Since these are of a lighter natural color, they are preferably scallop shells and / or oyster shells. They are present with a particle size of 100 μm or less, preferably 20 μm or less, and this particle size is measured using the laser diffraction method (ISO 13220-1 (2009)). The porous silica is derived from diatom skeletons. These are microalgae, which are single-celled organisms with silica skeletons. The porous silica in the diatom skeletons is farmed and thus renewable. The porous silica is present at a weight percentage of 2% to 20% of the total weight of the mineral filler. The microporous silica can be doped with other antibacterial additives such as silver ions, gold microparticles, or copper oxide microparticles to increase its antibacterial effect tenfold. - A dispersant with a weight percentage of 0.1% to 5%, preferably 0.1% to 1%. This can be natural wax, paraffin, surfactant, etc. - Optionally, a dyeing system, the weight percentage of which is 0% to 5%. For example, the dyeing system can be formed from one or more bio-based resins concentrated in natural coloring materials such as PA11 resin or PA10 resin. Optionally, the dyeing system can include a mineral material derived from shells having a size fraction collected by sieving or a combination of different size fractions, and the average size of these different fractions is larger, being 100 to 500 μm. Thereby, when a specific aesthetic effect is required, the shell grains can be visualized. The mineral material can be other types of shells such as the above-mentioned scallop shells, oyster shells, or mussel shells, in which case larger particles are selected. The percentage of this mineral material in the dyeing system can be 1% to 10% or 0% to 0.3% at an upper limit of 10% based on the total weight. - Optionally, a reinforcing material, the weight percentage of which is 0% to 8%. The reinforcing material can exist in various forms, for example, in the form of fibers or particles. For example, it can be a metal, mineral, or organic fiber of plant or non-plant origin. For example, calcium alginate fibers derived from seaweed are preferred. Alternatively, carbon fibers, glass fibers, or glass beads can be used. - Optionally, a coupling agent for optimizing the interface between the mineral filler, any reinforcing material, and the resin mixture. This coupling agent can be present at a weight percentage of 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.

[0011] The present invention further relates to a method for manufacturing the above article. It includes the following steps. - A step of providing porous silica derived from shells and diatom skeletons, - A step of providing one or more bio-based thermoplastic resins. Preferably, the one or more thermoplastic resins have a melt volume rate of less than 30 cm 3 / 10 minutes. - A step of collecting, sorting, washing, crushing, sieving shellfish, and retaining particles having a particle size of 100 μm or less, preferably 20 μm or less. - A step of mixing shell particles and porous silica, wherein the mixture forms a mineral filler. - A step of mixing the mineral filler and one or more thermoplastic resins with a dispersant. - Optionally, a step of adding a dyeing system, a reinforcing material, and / or a coupling agent to the mixture derived from the mineral filler, one or more thermoplastic resins, and the dispersant. - A step of molding the mixture derived from the mineral filler, one or more thermoplastic resins, and the dispersant with optional additives to obtain an article.

[0012] The molding can be carried out by injection molding after a prior compounding step by twin-screw extrusion and granulation. Alternatively, the manufacturing method can be carried out by extrusion.

[0013] Before crushing, the shellfish are sorted manually or automatically by color. To remove organic matter, it can be washed by physicochemical washing involving mechanical action such as brushing in a basic solution such as a bleaching agent.

[0014] To improve the compactness of the filler and be able to fill the system with resin at a level of 40% or more by weight, preferably, shell particles of different particle sizes are mixed to have a wider particle size distribution or a polymodal particle size distribution. For example, 100% of the fraction sieved at 10 μm, 50% of the fraction sieved at 20 μm, and 10% of the fraction sieved at 100 μm can be combined. The fraction with a larger particle size can be optionally recovered for use in a dyeing system to give a specific aesthetic appearance.

Claims

1. Articles made of composite materials containing by weight: one or more thermoplastic resins that are at least partially 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 diatom skeletons, the percentage of said mineral filler being between 25% and 79.9%; a dispersant, the percentage of which is between 0.1% and 5%, preferably between 0.1% and 1%, Optionally, a dye system, the percentage of which is between 0% and 5%; - optionally a reinforcing material, the percentage of which is between 0% and 8%; - Optionally, a coupling agent, the percentage of which is between 0% and 5%.

2. 10. The article according to the preceding claims, characterized in that said one or more thermoplastic resins, as a whole, are at least 60%, preferably at least 85%, more preferably at least 98% bio-based, said proportion being measured according to the standard ASTM D6866-22.

3. 2. The article of claim 1, wherein 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. 10. An article according to the preceding claims, characterized in that in the case of a 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 polyurethanes and polyether block amides, or it comprises several resins of the same type selected from said first and second lists.

5. 4. The article according to claim 3, characterized in that in the case of a 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 vulcanizate elastomers and thermoplastic styrene elastomers, or it comprises several resins of the same type selected from said list.

6. The article of claim 1, wherein the weight percentage of said inorganic filler is between 40% and 49.9% and the total weight percentage of said one or more thermoplastic resins is between 50% and 59.9%.

7. 2. The article of claim 1, wherein said porous silica is present in a weight percent of 2% to 20% of the weight of said mineral filler.

8. The article of claim 1 , wherein the porous silica is doped with one or more antimicrobial additives.

9. 10. The article of any preceding claim, wherein the one or more antimicrobial additives are selected from silver ions, gold particulates, and copper oxide particulates.

10. 2. An article according to claim 1, characterized in that the shell-based mineral material has a particle size of less than 100 μm, preferably less than 20 μm.

11. 10. The article of claim 1, wherein said dye system further comprises a shell-based mineral material, said mineral material having a particle size of 100 μm to 500 μm.

12. 10. An article according to the preceding claims, characterized in that the weight percentage of said mineral material is between 1% and 10%, based on the weight percentage of said dye system.

13. A method for producing the article of claim 1 comprising the steps of: Providing said shell-based mineral material and said diatom skeleton derived porous silica-based mineral material; b. providing one or more thermoplastic resins that are at least partially bio-based; c) collecting, sorting, washing, crushing and sieving said shells to retain only shell particles having a particle size of 100 μm or less; d. mixing the shell particles with porous silica, the mixture forming a mineral filler; e. mixing said mineral filler and said one or more thermoplastic resins with said dispersing agent; f. Optionally, adding the dye system, reinforcing agents and / or coupling agents to the mixture obtained in step e; g. molding the mixture obtained in step e or step f to obtain the article.

14. The one or more thermoplastic resins are 30 cm ３ 10. The method according to claim 1, characterized in that the melt volume fraction is less than 10 min. / 10 min.

15. 14. A method according to claim 13, characterized in that the shell particles of different sizes are mixed in step d to improve the compactness of the mineral filler.

16. 14. The method according to claim 13, characterized in that before crushing, washing is carried out by mechanical action in a basic solution.

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