Thermoset silicone filler, polymer compositions containing the same, and articles prepared therefrom

Abstract

A filled polymer composition is provided containing a thermoplastic matrix and a thermoset silicone resin filler in an amount of from 1 to 30 wt% based on total amount of polymer composition, where the thermoset silicone resin filler can be virgin resin, a mixture of virgin and reclaimed resin, or completely reclaimed resin, methods of making the filled polymer composition, and articles formed from the filled polymer composition.

Description

THERMOSET SILICONE FILLER, POLYMER COMPOSITIONS CONTAINING THE SAME, AND ARTICLES PREPARED THEREFROMCross-Reference to Related Applications

[0001] The present application is related to, and claims priority to, U.S. Provisional Application Serial No. 63 / 584,057, filed September 20, 2023, pending.Field of Invention

[0002] The present invention relates to a filled polymer composition wherein the filler is a thermoset silicone resin, and methods for producing the composition and articles made from the composition.Background

[0003] Many industries use polymers to prepare articles for use in commerce. This is especially prevalent in the production of small articles or parts that are readily replaceable, particularly in routine maintenance operations. Two such industries are the aeronautics and automotive industries. The interiors of airplanes and cars / trucks are increasingly using plastics / polymers in the preparation of various parts, in order to provide greater production efficiencies as well as reduce overall vehicle weight.

[0004] The various types of polymers that are used in the production of such parts include pure polymers, polymer blends, and polymers containing particulate and other types of fillers, in order to obtain various end use properties.

[0005] Polymer fillers can take many forms, and often are in the form of particles of varying size. The fillers have conventionally been various inorganic particles (such as TiC>2 or SiCh) or particulate polymers such as polycarbonate, polyurea or melamine. The fillers, particularly the particulate polymer fillers have typically been available as colored or colorless particles. In the case of the particulate polymer fillers, these polycarbonate, polyurea or melamine fillers have also been used as reclaimed fillers.

[0006] Thermoset silicon resin has usually been used as a virgin polymer material. Because of the extreme durability of silicon resins, they are not a raw material that is desirable to dispose of in a landfill. Unfortunately, however, it is estimated that to 500 metric tons of thermoset silicon resin will end up in a landfill each year, where it will likely not degrade and thus will remain for hundreds of years.

[0007] Accordingly, there is a desire to provide filled polymer compositions for use in making various articles, where the filled polymer composition makes use of thermoset silicon resins, particularly reclaimed thermoset silicon resins, as the filler in a thermoplastic matrix.Summary of Invention

[0008] Accordingly, one object of the present invention is to provide a filled polymer composition that is suitable for preparation of various articles having one or more properties including, but not limited to, improved traction or slip reduction, improved flame retardancy, better controlled surface roughness, color variations, lighter overall weight, and / or unique appearance properties.

[0009] A further object of the present invention is to provide a filled polymer composition using a reclaimed resin as filler, thus permitting the production of articles from the filled polymer composition having a more sustainable, “green” basis.

[0010] Another object of the present invention is to provide methods for production of the filled polymer compositions of the invention.

[0011] A further object of the present invention is to provide articles prepared from the filled polymer composition, with such articles being useful in a variety of end uses, including, but not limited to, decorative moldings, functional moldings, transparent lenses, etc.

[0012] These and other objects of the invention, either individually or in combinations, have been satisfied by the discovery of a filled polymer composition comprising a thermoplastic matrix and a thermoset silicone resin filler in an amount of from 1 to 30 wt% based on total amount of polymer composition, where any or all of the thermoset silicone resin may be a reclaimed thermoset silicone resin.Detailed Description

[0013] The present invention relates to a filled polymer composition comprising a thermoplastic matrix and a thermoset silicone resin filler in an amount of from 1 to 30 wt% based on total amount of polymer composition. Either or both of the thermoplastic matrix or the thermoset silicone resin filler can be virgin resin material or can be a reclaimed thermoset silicone resin. In the context of the present invention, the term “reclaimed” encompasses both the use of waste virgin resin (typically occurring from the production of virgin resin which usuallyresults in some level of product going to waste), or can be recycled resin that has previously been used and has been gathered for re-use in a different capacity.

[0014] When a reclaimed thermoset silicone resin is used, the amount can be any desired amount, and is typically at least 25 wt% reclaimed material, preferably at least 50 wt% reclaimed material, more preferably at least 75 wt% reclaimed material, most preferably 100 wt% reclaimed material, with the percentages based on the total amount of thermoset silicone resin present in the filled polymer composition.

[0015] Likewise, when a reclaimed thermoplastic matrix is used, the amount can also be any desired amount, and is typically at least 25 wt% reclaimed material, preferably at least 50 wt% reclaimed material, more preferably at least 75 wt% reclaimed material, most preferably 100 wt% reclaimed material, with the percentages based on the total amount of thermoplastic matrix present in the filled polymer composition.

[0016] In the present invention, it is possible to use any desired thermoplastic as the matrix polymer of the composition, depending on the ultimate end use and properties desired. The thermoplastic matrix material can be a single polymer or can be a polymer blend, again depending on the desired properties for the ultimate end use. In certain embodiments, the thermoplastic matrix material comprises at least one member selected from the group consisting of polyacrylates, polyurethanes, acrylonitrile butadiene styrene (ABS) resins, polyamides, polycarbonates, polyether sulfone resins, polyether ether ketone (PEEK) resins, polyolefins, polyphenylene oxide resins, polyphenylene sulfide resins, polystyrenes, polyvinyl chloride (PVC) resins, polyvinylidene fluoride(PVDF) resins, polyesters, and polytetrafluoroethylene (PTFE) resins. In certain preferred embodiments, the thermoplastic matrix material comprises at least one member selected from the group consisting of polyamides, polyesters, polyurethanes, polyolefins, polystyrenes, and polyvinyl chloride (PVC) resins. More preferred thermoplastic matrix resins comprises at least one member selected from the group consisting of polyurethanes and polyamides. A most preferred thermoplastic matrix resin comprises a polyurethane resin.

[0017] The thermoset silicone resin filler can be present in the filled polymer composition in any desired amount, depending on the properties desired in the ultimate end use product. In certain embodiments, the amount of thermoset silicone resin filler is in an amount of from 1 to 30 wt%, preferably 2 to 15 wt%, further preferably 2 to 9 wt%, more preferably 4 to 10 wt%, most preferably 4 to 8 wt% or 6 to 10 wt%, based on total amount of filled polymer composition.

[0018] The thermoset silicone resin filler can be sourced from any silicone resin. Suitable thermoset silicone resins can include any commercially available or reclaimed thermoset silicone resin, and include, but are not limited to CF-4721 thermosetting silicone resin available from Avantor, Inc. (based in Pennsylvania, USA) or Silicrumb recycled silicone rubber available from Advanced Polymers, Ltd (based in England).

[0019] As noted above, it is preferred that the thermoset silicone resin be sourced from reclaimed silicone resin, in order to provide improved sustainable products, and reduce the amount of resin going to landfills. The thermoset silicone resin is formed into the filler by a conventional grinding or milling process in order to provide thermoset silicone resin particles having particles sizes from 50 pm to 500 pm, preferably 75 pm to 400 pm, more preferably from 100 pm to300 pm. The filler particles as used will typically have a particle size distribution and are not all the same particle size. However, in certain embodiments, the particle size range can be minimized to provide highly uniform particles of the thermoset silicone resin filler, which can additionally provide unique properties in the filled polymer composition containing those particles.

[0020] The thermoset silicone resin filler can be clear and / or transparent, or have varying levels of opaqueness, depending on the presence of other additives or fillers within the silicone resin. Additionally, the thermoset silicone resin filler can be colorless or can be colored using various conventional colorant additives. When using a colored thermoset silicone resin filler in the present invention, the resulting polymer composition can be provided with unique color effects depending on the filler loading level, and the color of the thermoplastic matrix relative to the color of the thermoset silicone resin filler.

[0021] The filled polymer composition of the present invention can further comprise one or more additives conventionally used in the polymer industry. These additives include, but are not limited to, plasticizers, stabilizers, flame retardants, anti-static agents, colorants, antimicrobial agents, and lubricants. Selection of the particular additive(s) and the amounts used are within the skill on one of ordinary skill in the polymer industry.

[0022] The filled polymer composition of the present invention can be prepared in any manner sufficient to provide thorough distribution of the thermoset silicone resin filler throughout the thermoplastic matrix. In certain embodiments, the method comprises preparing a mixture of the thermoplastic matrix and the thermoset silicone resin filler, feeding the mixture in an extruder to heat and melt the thermoplastic matrix and disperse the thermoset silicone resin fillerthroughout the melted thermoplastic matrix, and extruding the resultant filled polymer composition through a die having a desired shape. In certain embodiments, the method comprises melting the thermoplastic matrix in an extruder, adding the thermoset silicone resin filler to the molten thermoplastic matrix in the extruder via a feed port to form a mixture, dispersing the thermoset silicone resin filler throughout the melted thermoplastic matrix with the extruder, and extruding the resultant mixture through a die having a desired shape.

[0023] In other embodiments, it may be desirable to form a masterbatch of the thermoplastic containing the thermoset silicone resin filler. Such a masterbatch can be prepared similarly to the above methods, but would contain the thermoset silicone resin filler in amounts from 15 to 60 wt% based on total amount of the masterbatch composition. This masterbatch composition could then be used as a base material to form desired filled polymer compositions of the present invention by combining it with one or more thermoplastic matrix resins to bring the total amount of thermoset silicone resin filler down to the range of the above noted compositions, notably 1 to 30 wt%, preferably 2 to 15 wt%, further preferably 2 to 9 wt%, more preferably 4 to 10 wt%, most preferably 4 to 8 wt% or 6 to 10 wt%, based on total amount of the filled polymer composition.

[0024] The methods used to prepare the filled polymer composition of the present invention and the articles formed therefrom, can use any desired type of extruder, including, but not limited to, single screw extruders, twin-screw extruders (corotating or counterrotating), or multi-screw extruders (for more complex production of multilayer products using the filled polymer composition of the present invention as one or more of the layers). The filled polymer composition can be prepared and extruded to form pellets which can later beremelted and formed into desired articles. Alternatively, the filled polymer composition can be formed in an extruder and directly extruded to form the desired end product article. Such article formation can be by extrusion of a desired shape (such as in forming a length of track used to house or cover electrical wiring) or can be pumped from the extruder into a mold to form a desired molded article. Such molding of an article can be by direct injection molding, or can include extrusion blow molding, or other molding techniques.

[0025] The article formed using the filled polymer composition of the present invention can be any desired polymer based article, including, but not limited to, vehicle seat tracks, vehicle seat parts, other vehicle interior parts, wire covering tracks, transparent lenses, and decorative parts. In certain embodiments, the thermoset silicone resin filler can be used to impart surface roughness to the article formed from the polymer composition of the present invention, providing improved traction and slip reduction. Articles or parts formed from the filled polymer composition of the present invention can have reduced overall weight relative to a part formed from 100% of thermoplastic matrix material. In preparation of articles and parts for use in an airplane, this reduction of overall weight can provide increased airplane efficiencies as more interior airplane parts are formed from the filled polymer composition of the invention.

[0026] The articles formed from the present filled polymer composition can also be provided with various surface roughness and color variation effects for cosmetic purposes, providing different textures for things like interior aircraft parts such as aircraft tray tables, molded wall panel separator tracks, seat armrests and seat backs, etc. Additionally, the filled polymer composition of thepresent invention can be configured in a manner to provide an article formed therefrom with a metallic visual appearance.

[0027] The filled polymer composition of the present invention can be tailored by choice of thermoplastic matrix resin and content of thermoset silicone resin filler to have a wide range of specific gravity and surface roughness, and a variety of mechanical properties. These can be selected based on the desired end use of the filled polymer composition, the properties needed in that end use, and the type of article being formed. In certain embodiments, the filled polymer composition of the present invention has a specific gravity of from 1.15 to 1.25, measured in accordance with ASTM-D792. In certain embodiments, the filled polymer composition of the present invention, when formed into an article, exhibits a surface roughness having an ISO Grade (N) of from N4 to N12 (corresponding to roughness values of Ra from 0.2 pm to 50 pm), preferably from N6 to N10 (corresponding to roughness values of Ra from 0.8 pm to 12.5 pm), wherein Ra is the average, or arithmetic average of profile height deviations on the surface from the mean line. The ISO Grade (N) can be measured, for example, in accordance with the ISO 4287:2000 standard. In certain embodiments, the filled polymer composition of the present invention has a tensile strength (as measured in accordance with ASTM D638) of from 6000 to 7000.

[0028] By way of example, if the end product to be formed from the filled polymer composition is a long extruded covering (such as a covering for a run of wiring in the floor, wall or ceiling of the interior of an airplane), the thermoplastic matrix and filler loading can be selected to provide malleability and flexibility of the covering to adapt to the channel through which the wiring is run. Such a partmight use, for example, a thermoplastic matrix that is a polyurethane resin, containing 4-8 wt% of the thermoset plastic filler having a filler particle size in the range from 100 to 300 pm. If the part is to be used as a seat track in an airplane interior, the thermoplastic matrix may be a different polyurethane or a polyurethane polymer blend, with different levels of the thermoset plastic filler. If the part is to be used as a transparent lens, the thermoplastic matrix polymer may be selected to be a polyester or polycarbonate, with the thermoset silicone resin filler being clear and colorless and having a particle size at the lower end of the size range of from 50 to 150 pm, to enable the lens to have the desired transparency. If the thermoset silicone resin has slightly different light diffraction properties than the thermoplastic resin, the resulting lens may have additional optical properties providing decorative light transmission effects.

[0029] The following is a listing of various embodiments of the present invention, which is not intended to be limiting, but is for illustrative purposes:Embodiment 1 . A filled polymer composition comprising a thermoplastic matrix and a thermoset silicone resin filler in an amount of from 1 to 30 wt% based on total amount of polymer composition.Embodiment 2. The filled polymer composition of Embodiment 1 , wherein the thermoset silicone resin filler comprises at least 25% reclaimed material.Embodiment 3. The filled polymer composition of one of Embodiment 1 or Embodiment 2, wherein the thermoset silicone resin filler comprises at least 50 wt% reclaimed material.Embodiment 4. The filled polymer composition of any one ofEmbodiments 1 to 3, wherein the thermoset silicone resin filler comprises at least 75 wt% reclaimed material.Embodiment 5. The filled polymer composition of any one of Embodiments 1 to 4, wherein the thermoset silicone resin filler comprises 100 wt% reclaimed material.Embodiment 6. The filled polymer composition of any one of Embodiments 1 to 5, wherein the thermoset silicone resin filler is present in an amount of from 2 to 15 wt% or 2 to 9 wt%, based on total amount of polymer composition.Embodiment 7. The filled polymer composition of any one of Embodiments 1 to 6, wherein the thermoset silicone resin filler is present in an amount of from 4 to 8 wt% or 6 to 10 wt%, based on total amount of polymer composition.Embodiment 8. The filled polymer composition of any one of Embodiments 1 to 7, wherein the thermoplastic matrix comprises at least one member selected from the group consisting of polyacrylates, polyurethanes, acrylonitrile butadiene styrene (ABS) resins, polyamides, polycarbonates, polyether sulfone resins, polyether ether ketone (PEEK) resins, polyolefins, polyphenylene oxide resins, polyphenylene sulfide resins, polystyrenes, polyvinyl chloride (PVC) resins, polyvinylidene fluoride (PVDF) resins, polyesters, and polytetrafluoroethylene (PTFE) resins.Embodiment 9. The filled polymer composition of any one ofEmbodiments 1 to 8, wherein the thermoplastic matrix comprises at least onemember selected from the group consisting of polyamides, polyesters, polyurethanes, polyolefins, polystyrenes, and polyvinyl chloride (PVC) resins.Embodiment 10. The filled polymer composition of any one of Embodiments 1 to 9, wherein the thermoplastic matrix comprises at least one member selected from the group consisting of polyurethanes and polyamides.Embodiment 11 . The filled polymer composition of any one ofEmbodiments 1 to 10, wherein the thermoplastic matrix comprises a polyurethane.Embodiment 12. The filled polymer composition of any one of Embodiments 1 to 11 , wherein the thermoset silicone resin filler has a particle size of from 50 pm to 500 pm.Embodiment 13. The filled polymer composition of any one of Embodiments 1 to 12, wherein the thermoset silicone resin filler has a particle size of from 75 pm to 400 pm.Embodiment 14. The filled polymer composition of any one of Embodiments 1 to 12, wherein the thermoset silicone resin filler has a particle size of from 100 pm to 300 pm.Embodiment 15. The filled polymer composition of any one of Embodiments 1 to 14, wherein the thermoset silicone resin filler is clear and colorless.Embodiment 16. The filled polymer composition of any one of Embodiments 1 to 14, wherein the thermoset silicone resin filler is clear and contains a colorant to impart a desired color to the thermoset silicone resin filler.Embodiment 17. The filled polymer composition of any one ofEmbodiments 1 to 16, wherein the thermoplastic matrix comprises at least 25 wt% reclaimed thermoplastic.Embodiment 18. The filled polymer composition of any one ofEmbodiments 1 to 17, wherein the thermoplastic matrix comprises at least 50 wt% reclaimed thermoplastic.Embodiment 19. The filled polymer composition of any one ofEmbodiments 1 to 18, wherein the thermoplastic matrix comprises at least 75 wt% reclaimed thermoplastic.Embodiment 20. The filled polymer composition of any one of Embodiments 1 to 19, wherein the thermoplastic matrix comprises 100 wt% reclaimed thermoplastic.Embodiment 21 . The filled polymer composition of any one of Embodiments 1 to 20, wherein the filled polymer composition further comprises one or more additives selected from the group consisting of plasticizers, stabilizers, flame retardants, anti-static agents, colorants, antimicrobial agents, and lubricants.Embodiment 22. A method for forming the filled polymer composition of any one of Embodiments 1 to 21 , comprising: a) preparing a mixture of the thermoplastic matrix and the thermoset silicone resin filler, heating the mixture in an extruder to melt the thermoplastic matrix and disperse the thermoset silicone resin filler throughout the melted thermoplastic matrix, and extruding the resultant filled polymer composition through a die having a desired shape; orb) melting the thermoplastic matrix in an extruder, adding the thermoset silicone resin filler to the extruder via a feed port to form a mixture, dispersing the thermoset silicone resin filler throughout the melted thermoplastic matrix and extruding the resultant mixture through a die having a desired shape. Embodiment 23. An article prepared from the filled polymer composition of any one of Embodiments 1 to 21 .Embodiment 24. The article of Embodiment 23, wherein the article is a member selected from the group consisting of seat tracks, wire covering tracks, transparent lenses, and decorative parts.

[0030] Although certain embodiments have been shown and described, it is understood that equivalents and modifications falling within the scope of the appended claims will occur to others who are skilled in the art upon the reading and understanding of this specification.

Claims

ClaimsWhat is claimed is:

1. A filled polymer composition comprising a thermoplastic matrix and a thermoset silicone resin filler in an amount of from 1 to 30 wt% based on total amount of polymer composition.

2. The filled polymer composition of claim 1 , wherein the thermoset silicone resin filler comprises at least 25% reclaimed material.

3. The filled polymer composition of claim 2, wherein the thermoset silicone resin filler comprises at least 50 wt% reclaimed material.

4. The filled polymer composition of claim 3, wherein the thermoset silicone resin filler comprises at least 75 wt% reclaimed material.

5. The filled polymer composition of claim 4, wherein the thermoset silicone resin filler comprises 100 wt% reclaimed material.

6. The filled polymer composition of claim 1 , wherein the reclaimed thermoset silicone resin filler is present in an amount of from 2 to 15 wt% or 2 to 9 wt%, based on total amount of polymer composition.

7. The filled polymer composition of claim 6, wherein the reclaimed thermoset silicone resin filler is present in an amount of from 4 to 8 wt% or 6 to 10 wt%, based on total amount of polymer composition.

8. The filled polymer composition of claim 1 , wherein the thermoplastic matrix comprises at least one member selected from the group consisting of polyacrylates, polyurethanes, acrylonitrile butadiene styrene (ABS) resins, polyamides, polycarbonates, polyether sulfone resins, polyether ether ketone (PEEK) resins, polyolefins, polyphenylene oxide resins,polyphenylene sulfide resins, polystyrenes, polyvinyl chloride (PVC) resins, polyvinylidene fluoride (PVDF) resins, polyesters, and polytetrafluoroethylene (PTFE) resins.

9. The filled polymer composition of claim 8, wherein the thermoplastic matrix comprises at least one member selected from the group consisting of polyamides, polyesters, polyurethanes, polyolefins, polystyrenes, and polyvinyl chloride (PVC) resins.

10. The filled polymer composition of claim 9, wherein the thermoplastic matrix comprises at least one member selected from the group consisting of polyurethanes and polyamides.11 . The filled polymer composition of claim 10, wherein the thermoplastic matrix comprises a polyurethane.

12. The filled polymer composition of claim 1 , wherein the thermoset silicone resin filler has a particle size of from 50 pm to 500 pm.

13. The filled polymer composition of claim 12, wherein the thermoset silicone resin filler has a particle size of from 75 pm to 400 pm.

14. The filled polymer composition of claim 13, wherein the thermoset silicone resin filler has a particle size of from 100 pm to 300 pm.

15. The filled polymer composition of claim 1 , wherein the thermoset silicone resin filler is clear and colorless.

16. The filled polymer composition of claim 1 , wherein the thermoset silicone resin filler is clear and contains a colorant to impart a desired color to the thermoset silicone resin filler.

17. The filled polymer composition of claim 1 , wherein the thermoplastic matrix comprises at least 25 wt% reclaimed thermoplastic.

18. The filled polymer composition of claim 17, wherein the thermoplastic matrix comprises at least 50 wt% reclaimed thermoplastic.

19. The filled polymer composition of claim 18, wherein the thermoplastic matrix comprises at least 75 wt% reclaimed thermoplastic.

20. The filled polymer composition of claim 19, wherein the thermoplastic matrix comprises 100 wt% reclaimed thermoplastic.21 . The filled polymer composition of claim 1 , wherein the filled polymer composition further comprises one or more additives selected from the group consisting of plasticizers, stabilizers, flame retardants, anti-static agents, colorants, antimicrobial agents, and lubricants.

22. A method for forming the filled polymer composition of claim 1 , comprising: a) preparing a mixture of the thermoplastic matrix and the thermoset silicone resin filler, heating the mixture in an extruder to melt the thermoplastic matrix and disperse the thermoset silicone resin filler throughout the melted thermoplastic matrix, and extruding the resultant filled polymer composition through a die having a desired shape; or b) melting the thermoplastic matrix in an extruder, adding the thermoset silicone resin filler to the extruder via a feed port to form a mixture, dispersing the thermoset silicone resin filler throughout the melted thermoplastic matrix and extruding the resultant mixture through a die having a desired shape.

23. An article prepared from the filled polymer composition of claim 1 .

4. The article of claim 23, wherein the article is a member selected from the group consisting of seat tracks, wire covering tracks, transparent lenses, and decorative parts.