阅读说明：本技术 用于摄像模组的芳族聚合物组合物 (Aromatic polymer composition for camera module ) 是由 金荣申 于 2018-11-28 设计创作，主要内容包括：提供一种聚合物组合物,其含有芳族聚合物与摩擦配制剂的组合。该聚合物组合物可以表现出低的表面摩擦程度,这使得在使用含有该组合物的部件(例如在摄像模组中)期间,皮层的剥离程度最小化。例如该聚合物组合物可以表现出约1.0或更小的动摩擦系数和/或磨损深度可以是约500微米或更小,如根据VDA 230-206:2007所测定。(A polymer composition is provided that contains an aromatic polymer in combination with a friction formulation. The polymer composition may exhibit a low degree of surface friction, which minimizes the degree of peeling of the skin layer during use of the component containing the composition (e.g., in a camera module). For example, the polymer composition can exhibit a dynamic coefficient of friction of about 1.0 or less and/or the wear depth can be about 500 microns or less as determined according to VDA 230-.)

1. A polymer composition comprising at least one aromatic polymer and a friction formulation in an amount of about 1 to about 20 parts by weight per 100 parts by weight of the aromatic polymer, wherein the friction formulation contains a fluorinated additive and a siloxane polymer having a weight average molecular weight of about 100000g/mol or greater, and further wherein the weight ratio of the fluorinated additive to the siloxane polymer is about 0.5 to about 12.

2. The polymer composition of claim 1, wherein the aromatic polymer comprises from about 20 wt% to about 70 wt% of the polymer composition, and the friction formulation comprises from about 1 wt% to about 30 wt% of the polymer composition.

3. The polymer composition of claim 1, wherein the silicone polymer is present in an amount of about 0.1 to about 20 parts by weight per 100 parts by weight of the aromatic polymer.

4. The polymer composition of claim 1, wherein the siloxane polymer comprises siloxane units in the backbone having the formula:

R_rSiO_(4-r/2)

wherein R is independently hydrogen or a substituted or unsubstituted hydrocarbyl group, and R is 0, 1,2, or 3.

5. The polymer composition of claim 4, wherein the siloxane polymer comprises alkyl groups bonded to at least 70 mol% of the Si atoms.

6. The polymer composition of claim 1, wherein the silicone polymer comprises a dimethylpolysiloxane, a phenylmethylpolysiloxane, a vinylmethylpolysiloxane, a trifluoropropylpolysiloxane, or a combination thereof.

7. The polymer composition of claim 1, wherein the silicone polymer has a kinematic viscosity of about 10000 centistokes or greater.

8. The polymer composition of claim 1, wherein the friction formulation further comprises silica particles.

9. The polymer composition of claim 1, wherein the fluorinated additive is present in an amount of about 0.1 to about 20 parts by weight per 100 parts by weight of the aromatic polymer.

10. The polymer composition of claim 1, wherein the fluorinated additive comprises a fluoropolymer.

11. The polymer composition of claim 10, wherein the fluoropolymer comprises polytetrafluoroethylene, perfluoroalkyl vinyl ether, poly (tetrafluoroethylene-co-perfluoroalkyl vinyl ether) fluorinated ethylene-propylene copolymer, ethylene-tetrafluoroethylene copolymer, polyvinylidene fluoride, polychlorotrifluoroethylene, or a combination thereof.

12. The polymer composition of claim 10 wherein the fluoropolymer is coated onto support particles.

13. The polymer composition of claim 12, wherein the carrier particles comprise silicate particles.

14. The polymer composition of claim 1, further comprising an inorganic filler in an amount of about 10 to about 95 parts by weight per 100 parts by weight of the aromatic polymer.

15. The polymer composition of claim 14, wherein the inorganic filler comprises particles having a hardness value of about 2.5 or greater on the mohs scale.

16. The polymer composition of claim 15, wherein the particles comprise barium sulfate.

17. The polymer composition of claim 1, further comprising an impact modifier in an amount of about 0.1 to about 20 parts by weight per 100 parts by weight of the aromatic polymer.

18. The polymer composition of claim 17, wherein the impact modifier comprises an epoxy-functionalized olefin copolymer.

19. The polymer composition of claim 1, further comprising an antistatic filler in an amount of about 0.1 to about 20 parts by weight per 100 parts by weight of the aromatic polymer.

20. The polymer composition of claim 19, wherein the antistatic filler comprises an ionic liquid.

21. The polymer composition of claim 1, wherein the aromatic polymer has a glass transition temperature of about 100 ℃ or greater and/or a melting temperature of about 200 ℃ or greater.

22. The polymer composition of claim 1, wherein the aromatic polymer is a thermotropic liquid crystalline polymer.

23. The polymer composition of claim 22, wherein the liquid crystalline polymer comprises repeating units derived from: terephthalic acid, isophthalic acid, 2, 6-naphthalenedicarboxylic acid, 4-hydroxybenzoic acid, 6-hydroxy-2-naphthoic acid, hydroquinone, 4' -biphenol, acetaminophen, or combinations thereof.

24. The polymer composition of claim 1, wherein the composition exhibits a dynamic coefficient of friction of about 1.0 or less as determined according to VDA230-206: 2007.

25. The polymer composition of claim 1, wherein the composition exhibits a wear depth of about 500 microns or less as determined according to VDA230-206: 2007.

26. The polymer composition of claim 1, wherein the composition exhibits a spiral flow length of about 15 millimeters or greater as determined according to ASTM D3121-09.

27. A molded part comprising the polymer composition of claim 1.

28. A camera module comprising the molded part of claim 26.

29. A camera module comprising a base on which is mounted a carrier assembly, wherein the base, the carrier assembly, or both comprise a molded part, wherein the molded part comprises a polymer composition comprising at least one thermotropic liquid crystalline polymer and a tribological formulation, wherein the composition exhibits a kinetic coefficient of friction of about 1.0 or less as determined according to VDA 230: 206: 2007.

30. The camera module of claim 29, wherein the composition exhibits a wear depth of about 500 microns or less as determined according to VDA 230-.

31. The camera module of claim 29, wherein the friction formulation comprises a siloxane polymer having a weight average molecular weight of about 100000g/mol or greater.

32. The camera module of claim 31, wherein the siloxane polymer has a kinematic viscosity of about 10000 centistokes or greater.

33. The camera module of claim 29, wherein the friction formulation further comprises a fluorinated additive.

34. The camera module of claim 33, wherein the fluorinated additive comprises a fluoropolymer.

35. The camera module of claim 34, wherein the fluoropolymer is coated onto silicate particles.

36. The camera module of claim 29, wherein the polymer composition further comprises inorganic filler particles having a hardness value of about 2.5 or greater on the mohs scale.

37. The camera module of claim 29, wherein the polymer composition further comprises an impact modifier.

38. The camera module of claim 29, wherein the polymer composition further comprises an antistatic filler.

39. The camera module of claim 29, wherein the liquid crystal polymer comprises repeating units derived from: terephthalic acid, isophthalic acid, 2, 6-naphthalenedicarboxylic acid, 4-hydroxybenzoic acid, 6-hydroxy-2-naphthoic acid, hydroquinone, 4' -biphenol, acetaminophen, or combinations thereof.

Background

Camera modules (or assemblies) are often used in mobile phones, laptops, digital cameras, digital camcorders, etc. Examples include, for example, compact camera modules including a carrier mounted on a base, digital camera shutter modules, components of digital cameras, video cameras in games, medical cameras, surveillance cameras, and the like. Such camera modules have become more complex and now tend to include multiple moving parts. For example, in some cases, two compact camera module assemblies may be mounted in a single module to improve image quality ("dual camera" module). In other cases, a compact camera module array may be employed. Regardless of the particular design, liquid crystal polymers are often used during manufacture due to their highly oriented crystalline structure, which makes the polymers easy to mold into very small and complex parts. Unfortunately, however, the highly oriented structure also makes the liquid crystal polymer susceptible to abrasion. That is, one or more skin layers of the polymer tend to peel away from the part during use, which can result in poor appearance and/or performance.

Also, there is a need for a polymer composition that can be easily used in a camera module.

Disclosure of Invention

In accordance with one embodiment of the present invention, a polymer composition is disclosed comprising at least one aromatic polymer (e.g., a thermotropic liquid crystalline polymer) and a friction formulation in an amount of about 1 to about 20 parts by weight per 100 parts by weight of the aromatic polymer. The friction formulation contains a fluorinated additive and a siloxane polymer having a weight average molecular weight of about 100000g/mol or greater. The weight ratio of the fluorinated additive to the silicone polymer is about 0.5 to about 12.

According to yet another embodiment of the present invention, a camera module is disclosed that includes a base on which a carrier assembly is mounted. The base, the carrier assembly, or both comprise molded parts. The molded part contains a polymer composition comprising at least one thermotropic liquid crystalline polymer and a friction formulation. The polymer composition exhibits a dynamic coefficient of friction of about 0.4 or less as determined according to VDA 230-.

Other features and aspects of the present invention are set forth in more detail below.

Brief Description of Drawings

A full and enabling disclosure of the present invention, including the best mode thereof to one skilled in the art, is set forth more particularly in the remainder of the specification, including reference to the accompanying figures, in which:

fig. 1-2 are perspective and front views of a compact camera module ("CCM") that can be formed in accordance with an embodiment of the present invention.

Detailed Description

Those skilled in the art will understand that the present discussion is a description of exemplary embodiments only, and is not intended as limiting the broader aspects of the present invention.

Generally, the present invention relates to a polymer composition containing a combination of an aromatic polymer and a friction formulation. By selectively controlling the nature of these components and their relative concentrations, the present inventors have found that the resulting polymer compositions can achieve a low degree of surface friction, which minimizes the degree of skin peeling during use of a part containing the composition (e.g., in a camera module). For example, the polymer composition may exhibit a dynamic coefficient of friction of about 1.0 or less, in some embodiments about 0.4 or less, in some embodiments about 0.35 or less, and in some embodiments from about 0.1 to about 0.3, as determined according to VDA 230-. Likewise, the wear depth may be about 500 microns or less, in some embodiments about 200 microns or less, in some embodiments about 100 microns or less, and in some embodiments from about 10 to about 70 microns, as determined according to VDA 230: 2007.

Conventionally, it is believed that components having such low friction surfaces will not also have sufficiently good mechanical properties. Contrary to conventional thinking, however, it has been found that the compositions of the present invention have excellent mechanical properties. For example, the composition may exhibit greater than about 20kJ/m²In some embodiments from about 25 to about 100kJ/m²And in some embodiments from about 30 to about 80kJ/m²The unnotched impact strength of (1) a simple beam as measured at 23 ℃ according to ISO test No. 179-1:2010 (technically equivalent to ASTM D256-10e 1). The composition may also exhibit greater than about 0.5kJ/m²In some embodiments from about 1 to about 20kJ/m²And in some embodiments from about 5 to about 15kJ/m²Is measured at 23 ℃ according to ISO test No. 179-1:2010 (technically equivalent to ASTM D256-10e 1). Tensile and flexural mechanical properties are also good. For example, the composition may exhibit a tensile strength of from about 20 to about 500MPa, in some embodiments from about 50 to about 400MPa, and in some embodiments, from about 60 to about 350 MPa; a tensile strain at break of about 1% or greater, in some embodiments from about 2% to about 15%, and in some embodiments, from about 3% to about 10%; and/or a tensile modulus of from about 4000MPa to about 20000MPa, in some embodiments from about 5000MPa to about 18000MPa, and in some embodiments, from about 6000MPa to about 12000 MPa. Tensile properties can be determined according to ISO test No. 527:2012 (technically equivalent to ASTM D638-14) at 23 ℃. The composition may also exhibit a flexural strength of from about 20 to about 500MPa, in some embodiments from about 50 to about 400MPa and in some embodiments from about 80 to about 350MPa and/or a flexural modulus of from about 4000MPa to about 20000MPa, in some embodiments from about 5000MPa to about 18000MPa and in some embodiments from about 6000MPa to about 15000 MPa. Flexural Properties may be measured according to ISOThe molded part may also exhibit a load deflection temperature (DTU L) of about 180 ℃ or greater and in some embodiments from about 190 ℃ to about 280 ℃ as determined by ASTM D648-07 (technically equivalent to ISO test number 75-2:2013) at a rated load of 1.8MPa, the Rockwell hardness of the part may also be about 25 or greater, in some embodiments about 30 or greater and in some embodiments from about 35 to about 80 as measured by ASTM D785-08 (Scale M).

In addition, the composition may also exhibit excellent antistatic behavior, particularly when an antistatic filler is included in the above-described polymer compositions¹⁵Ohmic or less, in some embodiments about 1 × 10¹⁴Ohmic or less, in some embodiments about 1 × 10¹⁰Ohm to about 9 × 10¹³Ohmic and in some embodiments about 1 × 10¹¹To about 1 × 10¹³Also, the molded part may exhibit a surface resistivity of about 1 × 10¹⁵Ohm-meters or less, in some embodiments about 1 × 10⁹Ohm-meter to about 9 × 10¹⁴Ohm-meter, and in some embodiments about 1 × 10¹⁰To about 5 × 10¹⁴Of course, such antistatic behavior is by no means desirable, for example, in some embodiments, the composition may exhibit a relatively high surface resistivity, for example, about 1 × 10¹⁵Ohmic or greater, and in some embodiments about 1 × 10¹⁶Ohmic or greater, and in some embodiments about 1 × 10¹⁷Ohm to about 9 × 10³⁰Ohmic, and in some embodiments about 1 × 10¹⁸To about 1 × 10²⁶Ohm.

Various embodiments of the present invention will now be described in more detail.

I.Polymer composition

A.Aromatic polymers

The aromatic polymer typically comprises from about 20 wt% to about 70 wt%, in some embodiments from about 30 wt% to about 65 wt%, and in some embodiments, from about 40 wt% to about 60 wt% of the polymer composition. The aromatic polymers are generally considered to be "high performance" polymers in that they have relatively high glass transition temperatures and/or high melting temperatures, depending on the specific properties of the polymer. Such high performance polymers may thus provide significant heat resistance to the resulting polymer composition. For example, the aromatic polymer may have a glass transition temperature of about 100 ℃ or greater, in some embodiments about 120 ℃ or greater, in some embodiments from about 140 ℃ to about 350 ℃, and in some embodiments, from about 150 ℃ to about 320 ℃. The aromatic polymer may also have a melting temperature of about 200 ℃ or greater, in some embodiments from about 220 ℃ to about 400 ℃, and in some embodiments, from about 240 ℃ to about 380 ℃. The glass transition and melting temperatures can be determined using differential scanning calorimetry ("DSC") as is well known in the art, for example, by ISO test numbers 11357-2:2013 (glass transition) and 11357-3:2011 (melting).

The aromatic polymer may be substantially amorphous, semi-crystalline or crystalline in nature. One example of a suitable semi-crystalline aromatic polymer is, for example, aramid. Particularly suitable aramids are those having a relatively high melting temperature, for example, about 200 ℃ or greater, in some embodiments about 220 ℃ or greater, and in some embodiments, from about 240 ℃ to about 320 ℃, as determined using differential scanning calorimetry in accordance with ISO test No. 11357. The glass transition temperature of the aramid is also typically from about 110 ℃ to about 160 ℃.

Aromatic polyamides typically contain repeating units held together by amide linkages (NH-CO) and are synthesized by the polycondensation of dicarboxylic acids (e.g., aromatic dicarboxylic acids), diamines (e.g., aliphatic diamines), and the like. For example, the aromatic polyamide may contain aromatic repeat units derived from aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, 2, 6-naphthalenedicarboxylic acid, 2, 7-naphthalenedicarboxylic acid, 1, 4-phenylenedioxy-diacetic acid, 1, 3-phenylenedioxy-diacetic acid, diphenic acid, 4 '-oxydibenzoic acid, diphenylmethane-4, 4' -dicarboxylic acid, diphenylsulfone-4, 4 '-dicarboxylic acid, 4' -biphenyldicarboxylic acid, and the like, as well as combinations thereof. Terephthalic acid is particularly suitable. Of course, it should also be understood that other types of acid units may be employed, such as aliphatic dicarboxylic acid units, polyfunctional carboxylic acid units, and the like. The aromatic polyamide may also contain aliphatic repeat units derived from aliphatic diamines, typically having 4 to 14 carbon atoms. Examples of such diamines include linear aliphatic alkylenediamines such as 1, 4-tetramethylenediamine, 1, 6-hexamethylenediamine, 1, 7-heptamethylenediamine, 1, 8-octamethylenediamine, 1, 9-nonanediamine, 1, 10-decanediamine, 1, 11-undecanediamine, 1, 12-dodecanediamine, etc.; branched aliphatic alkylenediamines such as 2-methyl-1, 5-pentanediamine, 3-methyl-1, 5-pentanediamine, 2,2, 4-trimethyl-1, 6-hexanediamine, 2, 4-dimethyl-1, 6-hexanediamine, 2-methyl-1, 8-octanediamine, 5-methyl-1, 9-nonanediamine, etc.; and combinations thereof. Repeat units derived from 1, 9-nonanediamine and/or 2-methyl-1, 8-octanediamine are particularly suitable. Of course, other diamine units such as cycloaliphatic diamines, aromatic diamines, and the like may also be used.

Particularly suitable polyamides may include poly (nonyleneterephthalamide) (PA9T), poly (nonyleneterephthalamide/nonylenesebacamide) (PA9T/910), poly (nonyleneterephthalamide/nonylenedodecanodiamide) (PA9T/912), poly (nonyleneterephthalamide/11-aminoundecanoamide) (PA9T/11), poly (nonyleneterephthalamide/12-aminododecanoamide) (PA9T/12), poly (decyleneoterephthalamide/11-aminoundecanoamide) (PA10T/11), poly (decyleneoterephthalamide/12-aminododecanoamide) (PA10T/12), poly (decyleneoterephthalamide/decyleneosebacamide) (PA10T/1010), poly (decyleneoterephthalamide/decylenedidiamide) (PA10T/1012), poly (decylene terephthalamide/tetramethylene hexanediamide) (PA10T/46), poly (decylene terephthalamide/caprolactam) (PA10T/6), poly (decylene terephthalamide/hexamethylene adipamide) (PA10T/66), poly (dodecylene terephthalamide/dodecanedodecane diamine) (PA12T/1212), poly (terephthalic acidDodecamethyleneadipamide/caprolactam) (PA12T/6), poly (dodecamethyleneadipamide/terephthalamide) (PA12T/66), and the like. Still other examples of suitable aramids are described inHarder et alIn us patent No. 8324307.

Another suitable semi-crystalline aromatic polymer that may be used in the present invention is a polyaryletherketone. Polyaryletherketones are semi-crystalline polymers having relatively high melting temperatures, such as from about 300 ℃ to about 400 ℃, in some embodiments from about 310 ℃ to about 390 ℃, and in some embodiments, from about 330 ℃ to about 380 ℃. The glass transition temperature may likewise be from about 110 ℃ to about 200 ℃. Particularly suitable polyaryletherketones are those comprising predominantly phenyl moieties in combination with ketone and/or ether moieties. Examples of such polymers include polyetheretherketone ("PEEK"), polyetherketone ("PEK"), polyetherketoneketone ("PEKK"), polyetherketoneetherketoneketone ("PEKEKK"), polyetheretherketoneketone ("PEEKK"), polyetheretherketone-diphenyl-ether-phenyl-ketone-phenyl, and the like, and blends and copolymers thereof.

As noted above, substantially amorphous polymers that do not have unique melting point temperatures can also be used in the polymer composition. Suitable amorphous polymers may include, for example, polyphenylene oxide ("PPO"), aromatic polycarbonates, aromatic polyetherimides, and the like. Aromatic polycarbonates, for example, typically have a glass transition temperature of about 130 ℃ to about 160 ℃ and contain aromatic repeat units derived from one or more aromatic diols. Particularly suitable aromatic diols are bisphenols, such as gem-bisphenols, in which two phenolic groups are attached to a single carbon atom of a divalent linking group. Examples of such bisphenols may include, for example, 4,4 '-isopropylidenediphenol ("bisphenol a"), 4,4' -ethylidene bisphenol, 4,4'- (4-chloro-a-methylbenzylidene) bisphenol, 4,4' -cyclohexylidene bisphenol, 4,4 (cyclohexylmethylene) bisphenol, and the like, and combinations thereof. The aromatic diol may be reacted with phosgene. For example, the phosgene may be of the formula C (O) Cl₂The carbonyl chloride of (1). An alternative route to the synthesis of aromatic polycarbonates may include the transesterification of an aromatic diol (e.g., a bisphenol) with diphenyl carbonate.

In addition to the polymers described above, crystalline polymers may also be used in the polymer composition. Particularly suitable are liquid crystalline polymers which have a high degree of crystallinity which enables them to effectively fill the small spaces of the mould. Liquid crystal polymers are generally classified as "thermotropic" in the sense that they can have a rod-like structure and exhibit crystalline behavior in their molten state (e.g., thermotropic nematic). The polymer has a relatively high melting temperature such as from about 250 ℃ to about 400 ℃, in some embodiments from about 280 ℃ to about 390 ℃, and in some embodiments, from about 300 ℃ to about 380 ℃. Such polymers may be formed from one or more types of repeating units known in the art. The liquid crystalline polymer may, for example, typically contain one or more aromatic ester repeat units in an amount of from about 60 mol% to about 99.9 mol%, in some embodiments from about 70 mol% to about 99.5 mol%, and in some embodiments, from about 80 mol% to about 99 mol% of the polymer. The aromatic ester repeat units can generally be represented by the following formula (I):

wherein the content of the first and second substances,

ring B is a substituted or unsubstituted 6-membered aryl group (e.g., 1, 4-phenylene or 1, 3-phenylene), a substituted or unsubstituted 6-membered aryl group (e.g., 2, 6-naphthalene) fused to a substituted or unsubstituted 5-or 6-membered aryl group, or a substituted or unsubstituted 6-membered aryl group (e.g., 4-biphenylene) linked to a substituted or unsubstituted 5-or 6-membered aryl group; and

Y₁and Y₂Independently O, C (O), NH, C (O) HN or NHC (O).

Typically, Y₁And Y₂Is c (o). Examples of such aromatic ester repeating units may include, for example, aromatic dicarboxylic repeating units (Y in formula I)₁And Y₂Is C (O), an aromatic hydroxycarboxylic acid repeating unit (Y in the formula I)₁Is O and Y₂Is C (O)), and various combinations thereof.

For example, aromatic dicarboxylic repeating units derived from aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, 2, 6-naphthalenedicarboxylic acid, diphenyl ether-4, 4 '-dicarboxylic acid, 1, 6-naphthalenedicarboxylic acid, 2, 7-naphthalenedicarboxylic acid, 4' -dicarboxybiphenyl, bis (4-carboxyphenyl) ether, bis (4-carboxyphenyl) butane, bis (4-carboxyphenyl) ethane, bis (3-carboxyphenyl) ether, bis (3-carboxyphenyl) ethane, and the like, as well as alkyl, alkoxy, aryl, and halogen substituents thereof, and combinations thereof, may be used. Particularly suitable aromatic dicarboxylic acids may include, for example, terephthalic acid ("TA"), isophthalic acid ("IA"), and 2, 6-naphthalene dicarboxylic acid ("NDA"). When used, the repeat units derived from aromatic dicarboxylic acids (e.g., IA, TA, and/or NDA) typically constitute from about 5 mol% to about 60 mol%, in some embodiments from about 10 mol% to about 55 mol%, and in some embodiments, from about 15 mol% to about 50% of the polymer.

Aromatic hydroxycarboxylic acid repeating units derived from aromatic hydroxycarboxylic acids, such as 4-hydroxybenzoic acid, and alkyl, alkoxy, aryl, and halogen substituents thereof, and combinations thereof, may also be used; 4-hydroxy-4' -biphenylcarboxylic acid; 2-hydroxy-6-naphthoic acid; 2-hydroxy-5-naphthoic acid; 3-hydroxy-2-naphthoic acid; 2-hydroxy-3-naphthoic acid; 4' -hydroxyphenyl-4-benzoic acid; 3' -hydroxyphenyl-4-benzoic acid; 4' -hydroxyphenyl-3-benzoic acid, and the like. Particularly suitable aromatic hydroxycarboxylic acids are 4-hydroxybenzoic acid ("HBA") and 6-hydroxy-2-naphthoic acid ("HNA"). When used, the repeat units derived from hydroxycarboxylic acids (e.g., HBA and/or HNA) typically constitute from about 10 mol% to about 85 mol%, in some embodiments from about 20 mol% to about 80 mol%, and in some embodiments, from about 25 mol% to about 75 mol% of the polymer.

Other repeating units may also be used for the polymer. For example, in certain embodiments, repeating units derived from aromatic diols such as hydroquinone, resorcinol, 2, 6-dihydroxynaphthalene, 2, 7-dihydroxynaphthalene, 1, 6-dihydroxynaphthalene, 4' -dihydroxybiphenyl (or 4,4' -biphenol), 3' -dihydroxybiphenyl, 3,4' -dihydroxybiphenyl, 4' -dihydroxybiphenyl ether, bis (4-hydroxyphenyl) ethane, and alkyl, alkoxy, aryl, and halogen substituents thereof, and combinations thereof, may be used. Particularly suitable aromatic diols may include, for example, hydroquinone ("HQ") and 4,4' -bisphenol ("BP"). When used, the repeat units from the aromatic diol (e.g., HQ and/or BP) typically comprise from about 1 mol% to about 30 mol%, in some embodiments from about 2 mol% to about 25 mol%, and in some embodiments, from about 5 mol% to about 20% of the polymer. Repeating units such as those derived from aromatic amides (e.g., acetaminophen ("APAP")) and/or aromatic amines (e.g., 4-aminophenol ("AP"), 3-aminophenol, 1, 4-phenylenediamine, 1, 3-phenylenediamine, etc.) may also be used. When used, the repeating units derived from an aromatic amide (e.g., APAP) and/or an aromatic amine (e.g., AP) typically constitute from about 0.1 mol% to about 20 mol%, in some embodiments from about 0.5 mol% to about 15 mol%, and in some embodiments, from about 1 mol% to about 10% of the polymer. It is also understood that various other monomer repeat units may be incorporated into the polymer. For example, in certain embodiments, the polymer may contain one or more repeat units derived from a non-aromatic monomer such as an aliphatic or cycloaliphatic hydroxycarboxylic acid, dicarboxylic acid, diol, amide, amine, and the like. Of course, in other embodiments, the polymer may be "fully aromatic" in that it lacks repeat units derived from non-aromatic (e.g., aliphatic or cycloaliphatic) monomers.

Although not required, the liquid crystalline polymer can be a "low naphthenic" polymer in the sense of containing a minimum content of repeating units derived from naphthenic hydroxycarboxylic acids and naphthenic dicarboxylic acids such as naphthalene-2, 6-dicarboxylic acid ("NDA"), 6-hydroxy-2-naphthoic acid ("HNA"), or combinations thereof. That is, the total amount of repeating units derived from naphthenic hydroxycarboxylic and/or dicarboxylic acids (e.g., NDA, HNA, or a combination of HNA and NDA) is typically no greater than 30 mol%, in some embodiments no greater than about 15 mol%, in some embodiments no greater than about 10 mol%, in some embodiments no greater than about 8 mol%, and in some embodiments 0 mol% to about 5 mol% (e.g., 0 mol%) of the polymer. While not having high levels of conventional naphthenic acids, it is believed that the resulting "low naphthenic" polymers can still exhibit good thermal and mechanical properties.

In a particular embodiment, the liquid crystalline polymer may be formed from repeat units derived from 4-hydroxybenzoic acid ("HBA") and terephthalic acid ("TA") and/or isophthalic acid ("IA") and various other optional ingredients. The repeat units derived from 4-hydroxybenzoic acid ("HBA") may comprise from about 10 mol% to about 80 mol%, in some embodiments from about 30 mol% to about 75 mol%, and in some embodiments, from about 45 mol% to about 70% of the polymer. The repeat units derived from terephthalic acid ("TA") and/or isophthalic acid ("IA") may likewise constitute from about 5 mol% to about 40 mol%, in some embodiments from about 10 mol% to about 35 mol%, and in some embodiments, from about 15 mol% to about 35% of the polymer. Repeat units derived from 4,4' -bisphenol ("BP") and/or hydroquinone ("HQ") may also be used in amounts of from about 1 mol% to about 30 mol%, in some embodiments from about 2 mol% to about 25 mol%, and in some embodiments, from about 5 mol% to about 20% of the polymer. Other possible repeat units may include those derived from 6-hydroxy-2-naphthoic acid ("HNA"), 2, 6-naphthalenedicarboxylic acid ("NDA"), and/or acetaminophen ("APAP"). In certain embodiments, the repeat units, e.g., from HNA, NDA, and/or APAP, may each comprise from about 1 mol% to about 35 mol%, in some embodiments from about 2 mol% to about 30 mol%, and in some embodiments, from about 3 mol% to about 25 mol%, when used.

B. Friction formulations

The friction formulation is also typically used in the polymer composition in an amount of from about 1 to about 30 parts, in some embodiments from about 2 to about 15 parts, and in some embodiments, from about 4 to about 12 parts per 100 parts of the aromatic polymer or polymers used in the polymer composition. For example, the friction formulation may comprise from about 1 wt% to about 30 wt%, in some embodiments from about 2 wt% to about 25 wt%, and in some embodiments, from about 4 wt% to about 10 wt% of the polymer composition.

The friction formulation typically contains a silicone polymer that improves internal lubrication and also helps to enhance the wear and frictional properties of the composition that encounters another surface. Such silicone polymers typically constitute from about 0.1 to about 20 parts, in some embodiments from about 0.4 to about 10 parts, and in some embodiments, from about 0.5 to about 5 parts per 100 parts of the aromatic polymer or polymers used in the composition. Any of a variety of silicone polymers may generally be used in the friction formulation. The siloxane polymer may, for example, encompass any polymer, copolymer, or oligomer that includes siloxane units having the formula in the backbone:

R_rSiO_(4-r/2)

wherein

R is independently hydrogen or substituted or unsubstituted hydrocarbyl, and

r is 0, 1,2 or 3.

Some examples of suitable groups R include, for example, alkyl, aryl, alkylaryl, alkenyl or alkynyl groups, or cycloalkyl groups, which are optionally substituted, and which may be interrupted by heteroatoms, i.e., may contain one or more heteroatoms in the carbon chain or ring. Suitable alkyl groups may include, for example, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, n-pentyl, isopentyl, neopentyl and tert-pentyl groups, hexyl groups (e.g., n-hexyl), heptyl groups (e.g., n-heptyl), octyl groups (e.g., n-octyl), isooctyl groups (e.g., 2, 4-trimethylpentyl), nonyl groups (e.g., n-nonyl), decyl groups (e.g., n-decyl), dodecyl groups (e.g., n-dodecyl), octadecyl groups (e.g., n-octadecyl), and the like. Likewise, suitable cycloalkyl groups may include cyclopentyl, cyclohexylcycloheptyl, methylcyclohexyl, and the like; suitable aryl groups may include phenyl, biphenyl, naphthyl, anthryl and phenanthryl; suitable alkylaryl groups can include o-, m-, or p-tolyl groups, xylyl groups, ethylphenyl groups, and the like; and suitable alkenyl or alkynyl groups may include ethenyl, 1-propenyl, 1-butenyl, 1-pentenyl, 5-hexenyl, butadienyl, hexadienyl, cyclopentenyl, cyclopentadienyl, cyclohexenyl, ethynyl, propargyl 1-propynyl, and the like. Examples of substituted hydrocarbon radicals are haloalkyl radicals (such as the 3-chloropropyl, 3,3, 3-trifluoropropyl and perfluorohexylethyl radicals) and haloaryl radicals (such as the p-chlorophenyl and p-chlorobenzyl radicals). In a particular embodiment, the siloxane polymer includes alkyl groups (e.g., methyl groups) bonded to at least 70 mol% of the Si atoms and optionally phenyl and/or vinyl groups bonded to 0.001 to 30 mol% of the Si atoms. The siloxane polymer also preferably comprises predominantly diorganosiloxane units. The end groups of the polyorganosiloxanes can be trialkylsiloxy, in particular trimethylsiloxy or dimethylvinylsiloxy. However, it is also possible that one or more of these alkyl groups have been substituted by hydroxy or alkoxy groups, such as methoxy or ethoxy. Particularly suitable examples of silicone polymers include, for example, dimethylpolysiloxane, phenylmethylpolysiloxane, vinylmethylpolysiloxane and trifluoropropylpolysiloxane.

The siloxane polymer may also include reactive functionality on at least a portion of the siloxane monomer units of the polymer, such as one or more vinyl groups, hydroxyl groups, hydrides, isocyanate groups, epoxy groups, acid groups, halogen atoms, alkoxy groups (e.g., methoxy, ethoxy, and propoxy), acyloxy groups (e.g., acetoxy and octanoyloxy groups), ketoxime groups (e.g., dimethyl ketoxime, methyl ketoxime, and methyl ethyl ketoxime), amino groups (e.g., dimethylamino, diethylamino, and butylamino groups), amide groups (e.g., N-methyl acetamide and N-ethyl acetamide), acid amide groups, aminoxy groups, mercapto groups, alkenyloxy groups (e.g., vinyloxy, isopropenyloxy, and 1-ethyl-2-methylvinyloxy groups), alkoxyalkoxy groups (e.g., methoxyethoxy, ethoxyethoxy, and methoxypropoxy groups), hydroxyl groups, hydride groups, hydroxyl groups, Aminooxy groups (e.g., dimethylaminoxy and diethylaminooxy), mercapto groups, and the like.

Regardless of its particular structure, the siloxane polymer typically has a relatively high molecular weight, which reduces the likelihood that it will migrate or diffuse to the surface of the polymer composition, and thus further minimizes the likelihood of phase separation. For example, the siloxane polymer typically has a weight average molecular weight of about 100000g/mol or greater, in some embodiments about 200000g/mol or greater, and in some embodiments, from about 500000g/mol to about 2000000 g/mol. The siloxane polymers may also have a relatively high kinematic viscosity, for example, about 10000 centistokes or greater, in some embodiments about 30000 centistokes or greater, and in some embodiments, from about 50000 to about 500000 centistokes.

If desired, silica particles (e.g., fumed silica) can also be used in combination with the siloxane polymer,to help improve its ability to disperse in the composition. Such silica particles may, for example, have a particle size of about 5 nanometers to about 50 nanometers, about 50 square meters per gram (m)²Per g) to about 600m²Surface area per gram, and/or about 160 kilograms per cubic meter (kg/m)³) To about 190kg/m³The density of (c). When used, the silica particles typically comprise about 1 to about 100 parts by weight, and in some embodiments about 20 to about 60 parts by weight, based on 100 parts by weight of the siloxane polymer. In one embodiment, the silica particles may be combined with a siloxane polymer and the mixture then added to the polymer composition. For example, a mixture comprising ultra-high molecular weight polydimethylsiloxane and fumed silica may be incorporated into the polymer composition. Such a preformed mixture is available from Wacker Chemie, AGPellet S is available.

The friction formulation may also contain other components that may help the resulting polymer composition achieve a good combination of low friction and good abrasion resistance. In one embodiment, for example, the friction formulation may use a combination of fluorinated additives and silicone polymers. Without intending to be limited by theory, it is believed that the fluorinated additive may improve processing of the composition, among other things, such as by providing better mold filling, internal lubrication, mold release, and the like. When used, the weight ratio of the fluorinated additive to the silicone polymer is typically from about 0.5 to about 12, in some embodiments from about 0.8 to about 10, and in some embodiments, from about 1 to about 6. For example, the fluorinated additive may comprise from about 0.1 to about 20 parts, in some embodiments from about 0.5 to about 15 parts, and in some embodiments, from about 1 to about 10 parts per 100 parts of the one or more aromatic polymers used in the composition.

In certain embodiments, the fluorinated additive may include a fluoropolymer comprising a hydrocarbon backbone polymer in which some or all of the hydrogen atoms are replaced with fluorine atoms. The backbone polymer may be polyolefinic and formed from fluorine-substituted unsaturated olefin monomers. The fluoropolymer may be a homopolymer of such a fluorine-substituted monomer or a copolymer of a fluorine-substituted monomer or a mixture of a fluorine-substituted monomer and a non-fluorine-substituted monomer. In addition to fluorine atoms, the fluoropolymer may also be substituted with other halogen atoms such as chlorine and bromine atoms. Representative monomers suitable for forming the fluoropolymers used in the present invention are tetrafluoroethylene, vinylidene fluoride, hexafluoropropylene, chlorotrifluoroethylene, perfluoroethyl vinyl ether, perfluoromethyl vinyl ether, perfluoropropyl vinyl ether, and the like, and mixtures thereof. Specific examples of suitable fluoropolymers include polytetrafluoroethylene, perfluoroalkyl vinyl ether, poly (tetrafluoroethylene-co-perfluoroalkyl vinyl ether), fluorinated ethylene-propylene copolymer, ethylene-tetrafluoroethylene copolymer, polyvinylidene fluoride, polychlorotrifluoroethylene, and the like, and mixtures thereof.

The fluorinated additive may contain only the fluoropolymer, or it may also include other ingredients such as those that aid in its ability to be uniformly dispersed within the polymer composition. In one embodiment, for example, the fluorinated additive may comprise a fluoropolymer in combination with a plurality of support particles. In such embodiments, for example, the fluoropolymer may be coated onto the support particles. Silicate particles such as talc (Mg)₃Si₄O₁₀(OH)₂) Halloysite (Al)₂Si₂O₅(OH)₄) Kaolinite (Al)₂Si₂O₅(OH)₄) Illite ((K, H)₃O)(Al,Mg,Fe)₂(Si,Al)₄O₁₀[(OH)₂,(H₂O)]) Montmorillonite (Na, Ca)_0.33(Al,Mg)₂Si₄O₁₀(OH)₂·nH₂O), vermiculite ((MgFe, Al)₃(Al,Si)₄O₁₀(OH)₂·4H₂O), palygorskite ((Mg, Al)₂Si₄O₁₀(OH)·4(H₂O)), pyrophyllite (Al)₂Si₄O₁₀(OH)₂) Calcium silicate, aluminum silicate, mica, diatomaceous earth, wollastonite, and the like are particularly suitable for this purpose. For example, mica may be a particularly suitable mineral for use in the present invention. There are several chemical aspectsUnique mica species that have considerable variation in geological occurrence, but all have substantially the same crystal structure. As used herein, the term "mica" is meant to generally include any of these species such as muscovite (KAl)₂(AlSi₃)O₁₀(OH)₂) Biotite (K (Mg, Fe)₃(AlSi₃)O₁₀(OH)₂) Phlogopite (KMg)₃(AlSi₃)O₁₀(OH)₂) Lepidolite (K (L i, Al)_2-3(AlSi₃)O₁₀(OH)₂) Glauconite (K, Na) (Al, Mg, Fe)₂(Si,Al)₄O₁₀(OH)₂) And the like and combinations thereof. The carrier particles may have an average particle size of about 5 to about 50 microns, and in some embodiments about 10-20 microns. If desired, the carrier particles may also be in the shape of plate-like particles in which the ratio of their major axis to their thickness is 2 or more.

C.Other optional Components

i.Inorganic filler

Inorganic fillers may be used to improve certain properties of the polymer composition, if desired. For example, the inventors have found that the use of inorganic fillers of certain hardness values can improve the mechanical strength, adhesive strength and surface smoothness of parts containing the composition. The resulting polymer composition may also enable less delamination of the polymer skin, which makes it particularly suitable for use in very small parts. The inorganic filler may be used in the polymer composition in an amount of from about 10 to about 95 parts by weight, in some embodiments from about 20 to about 90 parts by weight, and in some embodiments, from about 50 to about 85 parts by weight per 100 parts of the one or more aromatic polymers used in the polymer composition. For example, the inorganic filler may comprise from about 10 wt% to about 70 wt%, in some embodiments from about 20 wt% to about 60 wt%, and in some embodiments, from about 30 wt% to about 60 wt% of the polymer composition.

The nature of the inorganic filler may vary, for example, particles, fibers, and the like. In certain embodiments, for example, inorganic filler particles having certain hardness values may be used to help improve the compositionThe surface properties of (1). For example, the hardness value may be about 2.5 or greater, in some embodiments about 3.0 or greater, in some embodiments from about 3.0 to about 11.0, in some embodiments from about 3.5 to about 11.0, and in some embodiments, from about 4.5 to about 6.5, on the mohs scale. Examples of such particles may include, for example, carbonates such as calcium carbonate (CaCO)₃Mohs hardness of 3.0) or basic copper carbonate (Cu)₂CO₃(OH)₂Mohs hardness 4.0); fluorides such as calcium fluoride (CaFl)₂Mohs hardness 4.0); phosphates such as calcium pyrophosphate ((Ca)₂P₂O₇Mohs hardness 5.0), dicalcium phosphate anhydrous (CaHPO)₄Mohs hardness 3.5), or aluminum phosphate hydrate (AlPO)₄·2H₂O, mohs hardness 4.5); silicates such as Silica (SiO)₂Mohs hardness 6.0), potassium aluminum silicate (KAlSi)₃O₈Mohs hardness of 6), or copper silicate (CuSiO)₃·H₂O, mohs hardness 5.0); borates such as calcium borosilicate hydroxide (Ca)₂B₅SiO₉(OH)₅Mohs hardness 3.5); aluminum oxide (AlO)₂Mohs hardness 10.0); sulfates such as calcium sulfate (CaSO)₄Mohs hardness 3.5) or barium sulfate (BaSO)₄Mohs hardness of 3-3.5), and the like, and combinations thereof, when used, the inorganic particles typically have a median size (e.g., diameter) of from about 0.1 to about 35 micrometers, in some embodiments from about 2 to about 20 micrometers, in some embodiments from about 3 to about 15 micrometers, and in some embodiments from about 7 to about 12 micrometers, as determined, for example, using laser diffraction techniques according to ISO13320:2009 (e.g., using a Horiba L A-960 particle size distribution analyzer). Filler inorganic particles may also have a narrow size distribution.

The inorganic filler may also be a fiber derived from a material having a desired hardness value. Particularly suitable fibers for this purpose include those derived from minerals including silicates such as nesosilicates, sorosilicates, inosilicates (e.g. calcium)Inosilicates such as wollastonite; calcium magnesium chain silicates such as tremolite; calcium magnesium iron chain silicates such as actinolite; magnesium iron chain silicates such as tremolite; etc.), layered silicates (e.g., aluminum layered silicates such as palygorskite), network silicates, etc.; sulfates such as calcium sulfate (e.g., dehydrated or anhydrite); mineral wool (e.g., rock wool or slag wool); and the like. Particularly suitable are fibers derived from inosilicates, such as wollastonite (Mohs hardness 4.5-5.0), which is known under the trade name wollastonite(e.g. in4W or8) Such mineral fibers may also have a narrow size distribution, i.e., at least about 70 volume percent, in some embodiments at least about 80 volume percent, and in some embodiments at least about 90 volume percent of the fibers may have a size within the above-noted ranges.

ii.Impact modifiers

If desired, impact modifiers may also be used in the polymer composition to help improve the impact strength and flexibility of the polymer composition. Indeed, the inventors have found that impact modifiers can actually make the surface of the molded part smoother and minimize the likelihood of the skin peeling therefrom during use. When used, the impact modifier typically comprises from about 0.1 to about 20 parts by weight, in some embodiments from about 0.2 to about 10 parts by weight, and in some embodiments, from about 0.5 to about 5 parts by weight, per 100 parts of the aromatic polymer or polymers used in the polymer composition. For example, the impact modifier may comprise from about 0.1 wt% to about 10 wt%, in some embodiments from about 0.2 wt% to about 8 wt%, and in some embodiments, from about 0.5 wt% to about 4 wt% of the polymer composition.

For example, one particularly suitable type of impact modifier may include olefin copolymers that are "epoxy functionalized" in that it contains an average of two or more epoxy functional groups per molecule, the copolymer typically containing olefin monomer units derived from one or more α -olefins, examples of such monomers include, for example, linear and/or branched α -olefins having 2-20 carbon atoms and typically 2-8 carbon atoms, specific examples include ethylene, propylene, 1-butene, 3-methyl-1-butene, 3-dimethyl-1-butene, 1-pentene with one or more methyl, ethyl or propyl substituents, 1-hexene with one or more methyl, ethyl or propyl substituents, 1-heptene with one or more methyl, ethyl or propyl substituents, 1-octene with one or more methyl, ethyl or propyl substituents, 1-nonene with one or more methyl, ethyl or propyl substituents, ethyl, or dimethyl substituted 1-heptene, 1-octene with one or more methyl, ethyl or propyl substituents, 1-nonene with one or more methyl, ethyl or propyl substituents, ethylene glycidyl acrylate, and other suitable monomers such as glycidyl acrylate monomers, and glycidyl methacrylate, and other suitable monomers may include, such as epoxy functional monomers, glycidyl acrylate monomers, and glycidyl acrylate monomers, such as those containing glycidyl methacrylate, and glycidyl methacrylate.

Examples of such (meth) acrylic monomers may include methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, sec-butyl acrylate, isobutyl acrylate, tert-butyl acrylate, n-pentyl acrylate, isopentyl acrylate, isobornyl acrylate, n-hexyl acrylate, 2-ethylbutyl acrylate, 2-ethylhexyl acrylate, n-octyl acrylate, n-decyl acrylate, methylcyclohexyl acrylate, cyclopentyl acrylate, cyclohexyl acrylate, methyl methacrylate, ethyl methacrylate, 2-hydroxyethyl methacrylate, n-propyl methacrylate, n-butyl methacrylate, isopropyl methacrylate, isobutyl methacrylate, n-pentyl methacrylate, n-hexyl methacrylate, isopentyl methacrylate, sec-butyl methacrylate, tert-butyl methacrylate, 2-ethylbutyl methacrylate, methylcyclohexyl methacrylate, cinnamyl methacrylate, crotyl methacrylate, cyclohexyl methacrylate, sec-butyl methacrylate, tert-butyl methacrylate, 2-ethylbutyl methacrylate, isobornyl methacrylate, a copolymer of the formula (i.e. a copolymer of the formula of a non-epoxy functional acrylic monomer, glycidyl methacrylate, a copolymer of the formula (e.g. a) copolymer of the formula (i) and a copolymer of the formula (i) may be copolymerized with a specific epoxy-functional monomer, such as a terpolymer of formula, a copolymer of the formula (e.g. a copolymer of the formula α):

wherein x, y and z are 1 or greater.

More particularly, a high epoxy monomer content may result in good reactivity with the matrix polymer, but an excessively high content may reduce the melt flow rate to such an extent that the copolymer adversely affects the melt strength of the polymer blend. accordingly, in most embodiments, one or more epoxy-functional (meth) acrylic monomers comprise from about 1 wt% to about 20 wt%, in some embodiments from about 2 wt% to about 15 wt%, and in some embodiments from about 3 wt% to about 10 wt% of the copolymer, one or more α -olefin monomers may likewise comprise from about 55 wt% to about 95 wt%, in some embodiments from about 60 wt% to about 90 wt%, and in some embodiments from about 65 wt% to about 85 wt% of the copolymer, while in use, other monomer components (e.g., non-epoxy-functional (meth) acrylic monomers may comprise from about 5 wt% to about 90 wt% of the copolymer, in some embodiments from about 65 wt% to about 10 wt%, and in some embodiments from about 10 wt% to about 10 g/min ("ASTM flow rate from about 10 g/min") of the resulting copolymer, in some embodiments from about 5 wt% to about 10 wt%, and in some embodiments from about 10 g/min to about 10 g/10 g/min.

An example of a suitable epoxy-functional copolymer that may be used in the present invention is under the nameCommercially available from Arkema at AX 8840.AX8840, for example, has a melt flow rate of 5g/10min and has a glycidyl methacrylate monomer content of 8 wt%. Another suitable copolymer is under the nameCommercially available from DuPont under PTW isA terpolymer of ethylene, butyl acrylate and glycidyl methacrylate and having a melt flow rate of 12g/10min and a glycidyl methacrylate monomer content of 4 wt% to 5 wt%.

iii.Antistatic filler

Antistatic fillers may also be used in the polymer composition to help reduce the tendency for static charges to develop during molding operations, transportation, collection, assembly, and the like. Such fillers, when used, typically constitute from about 0.1 to about 20 parts by weight, in some embodiments from about 0.2 to about 10 parts by weight, and in some embodiments, from about 0.5 to about 5 parts by weight, per 100 parts of the aromatic polymer or polymers used in the polymer composition. For example, the antistatic filler may comprise from about 0.1 wt% to about 10 wt%, in some embodiments from about 0.2 wt% to about 8 wt%, and in some embodiments, from about 0.5 wt% to about 4 wt% of the polymer composition.

Any of a variety of antistatic fillers can generally be used in the polymer composition to help improve its antistatic properties. Examples of suitable antistatic fillers may include, for example, metal particles (e.g., aluminum flakes), metal fibers, carbon particles (e.g., graphite, expanded graphite, graphene (graphene), carbon black, graphitized carbon black, and the like), carbon nanotubes, carbon fibers, and the like. Carbon fibers and carbon particles (e.g., graphite) are particularly suitable. When used, suitable carbon fibers may include pitch-based carbons (e.g., pitch), polyacrylonitrile-based carbons, metal-coated carbons, and the like. Desirably, the carbon fibers are of high purity in that they have a relatively high carbon content, such as a carbon content of about 85 wt% or greater, in some embodiments about 90 wt% or greater, and in some embodiments, about 93 wt% or greater. For example, the carbon content may be at least about 94% wt, such as at least about 95% wt, such as at least about 96% wt, such as at least about 97% wt, such as even at least about 98% wt. The carbon purity is typically less than 100 wt%, for example less than about 99 wt%. The density of the carbon fibers is typically from about 0.5 to about 3.0g/cm³In some embodiments from about 1.0 to about 2.5g/cm³And in some embodiments from about 1.5 to about 2.0g/cm³。

In one embodiment, the carbon fibers are incorporated into the matrix with minimal fiber breakage. Even when fibers having an initial length of about 3mm are used, the volume average length of the fibers after molding may typically be about 0.1mm to about 1 mm. The average length and distribution of the carbon fibers can also be selectively controlled in the final polymer composition to achieve better connection and electrical pathways in the liquid crystalline polymer matrix. The average diameter of the fibers may be from about 0.5 to about 30 microns, in some embodiments from about 1 to about 20 microns, and in some embodiments, from about 3 to about 15 microns.

To improve dispersion in the polymer matrix, the carbon fibers may be at least partially coated with a sizing agent that increases the compatibility of the carbon fibers with the liquid crystalline polymer. The sizing agent may be stable such that it does not thermally degrade at the temperature at which the liquid crystal polymer is molded. In one embodiment, the sizing agent may include a polymer such as an aromatic polymer. For example, the aromatic polymer can have a thermal decomposition temperature greater than about 300 ℃, such as greater than about 350 ℃, for example greater than about 400 ℃. As used herein, the thermal decomposition temperature of a material is the temperature at which the material loses 5% of its mass during thermogravimetric analysis as determined according to ASTM test E1131 (or ISO test 11358). Sizing agents may also have relatively high glass transition temperatures. For example, the glass transition temperature of the sizing agent may be greater than about 300 deg.C, such as greater than about 350 deg.C, such as greater than about 400 deg.C. Specific examples of sizing agents include polyimide polymers, aromatic polyester polymers (including wholly aromatic polyester polymers), and high temperature epoxy polymers. In one embodiment, the sizing agent may include a liquid crystal polymer. The sizing agent may be present on the fibers in an amount of at least about 0.1% wt, such as in an amount of at least 0.2% wt, such as in an amount of at least about 0.1% wt. Sizing agents are generally present in amounts less than about 5% wt, for example in amounts less than about 3% wt.

Another suitable antistatic filler is an ionic liquid. One benefit of such materials is that in addition to being an antistatic agent, the ionic liquid may also be present in liquid form during melt processing, which allows it to be more uniformly blended within the polymer matrix. This improves the electrical connection and thereby enhances the ability of the composition to rapidly dissipate static charges from its surface.

The ionic liquid is typically a salt having a melting temperature sufficiently low that it can be in liquid form when melt processed with a liquid crystalline polymer. For example, the melting temperature of the ionic liquid may be about 400 ℃ or less, in some embodiments about 350 ℃ or less, in some embodiments from about 1 ℃ to about 100 ℃, and in some embodiments, from about 5 ℃ to about 50 ℃. The salt contains a cationic species and a counterion. Cationic species contain compounds having at least one heteroatom (e.g., nitrogen or phosphorus) as a "cationic center". Examples of such heteroatom compounds include, for example, quaternary phosphonium compounds having the structure

Wherein R is¹、R²、R³、R⁴、R⁵、R⁶、R⁷And R⁸Independently selected from hydrogen; substituted or unsubstituted C₁-C₁₀Alkyl (e.g., methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, etc.); substituted or unsubstituted C₃-C₁₄Cycloalkyl groups (e.g., adamantyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclooctyl, cyclohexenyl, and the like); substituted or unsubstituted C₁-C₁₀Alkenyl groups (e.g., ethylene, propylene, 2-methylpropene, pentene, etc.); substituted or unsubstituted C₂-C₁₀Alkynyl groups (e.g., ethynyl, propynyl, etc.); substituted or unsubstituted C₁-C₁₀Alkoxy (e.g., methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, tert-butoxy, sec-butoxy, n-pentoxy, etc.); substituted or unsubstituted acyloxy (e.g., methacryloxy, methacryloxyethyl, etc.); substituted or unsubstituted aryl (e.g., phenyl); substituted or unsubstituted heteroaryl (e.g. pyridyl, furyl, thienyl, thiazolyl, isothiazolyl)Azolyl, triazolyl, imidazolyl, isoimidazolylOxazolyl, pyrrolyl, pyrazolyl, pyridazinyl, pyrimidinyl, quinolinyl, and the like); and the like. In a particular embodiment, for example, the cationic species can be of structure N⁺R¹R²R³R⁴Wherein R is¹、R²And/or R³Independently is C₁-C₆Alkyl (e.g., methyl, ethyl, butyl, etc.) and R⁴Is hydrogen or C₁-C₄Alkyl (e.g., methyl or ethyl). For example, the cationic component can be tributylmethylammonium, wherein R¹、R²And R³Is butyl and R⁴Is methyl.

Suitable counter ions for the cationic species may include, for example, halogens (e.g., chloride, bromide, iodide, etc.); sulfate or sulfonate groups (e.g., methyl sulfate, ethyl sulfate, butyl sulfate, hexyl sulfate, octyl sulfate, hydrogen sulfate, methane sulfonate, dodecyl benzene sulfonate, dodecyl sulfate, trifluoromethane sulfonate, heptadecafluorooctane sulfonate, sodium lauryl ethoxy sulfate, etc.); a sulfosuccinate; amides (e.g., dicyandiamide); imides (e.g., bis (pentafluoroethyl-sulfonyl) imide, bis (trifluoromethylsulfonyl) imide, bis (trifluoromethyl) imide, and the like); borates (e.g., tetrafluoroborate, tetracyanoborate, bis [ oxalato ] borate, bis [ salicylato ] borate, etc.); phosphate or phosphinate (e.g., hexafluorophosphate, diethylphosphate, bis (pentafluoroethyl) phosphinate, tris (pentafluoroethyl) -trifluorophosphate, tris (nonafluorobutyl) trifluorophosphate, etc.); antimonate (e.g., hexafluoroantimonate); aluminates (e.g., tetrachloroaluminate); fatty acid carboxylates (e.g., oleate, isostearate, pentadecafluorooctanoate, etc.); cyanate radical; acetate radical; and the like, as well as combinations of any of the foregoing. To help improve compatibility with liquid crystal polymers, it may be desirable to select counter ions such as imides, fatty acid carboxylates, etc., which are generally hydrophobic in nature. Particularly suitable hydrophobic counterions can include, for example, bis (pentafluoroethylsulfonyl) imide, bis (trifluoromethylsulfonyl) imide and bis (trifluoromethyl) imide.

iv.Other additives

A wide variety of additional additives may also be included in the polymer composition, such as lubricants, thermally conductive fillers, pigments, antioxidants, stabilizers, surfactants, waxes, flame retardants, anti-drip additives, and other materials added to enhance performance and processability. For example, lubricants that are capable of withstanding the processing conditions of the liquid crystalline polymer without significant decomposition may be used in the lubricant polymer composition. Examples of such lubricants include fatty acid esters, salts thereof, esters, fatty acid amides, organic phosphate esters, and hydrocarbon waxes of the type commonly used as lubricants in engineering plastic processing, including mixtures thereof. Suitable fatty acids typically have a backbone carbon chain of about 12 to about 60 carbon atoms, such as myristic acid, palmitic acid, stearic acid, arachidic acid, montanic acid, stearic acid (octadecynic acid), parinaric acid (parinaric acid), and the like. Suitable esters include fatty acid esters, fatty alcohol esters, wax esters, glycerol esters, glycol esters, and complex esters. Fatty acid amides include fatty primary amides, fatty secondary amides, methylene and ethylene bisamides, and alkanolamides, such as palmitic acid amide, stearic acid amide, oleic acid amide, N' -ethylene bisstearamide, and the like. Also suitable are metal salts of fatty acids such as calcium stearate, zinc stearate, magnesium stearate, and the like; hydrocarbon waxes, including paraffin, polyolefin and oxidized polyolefin waxes and microcrystalline waxes. Particularly suitable lubricants are acids, salts or amides of stearic acid, for example pentaerythritol tetrastearate, calcium stearate, or N, N' -ethylene bisstearamide. When used, the one or more lubricants typically comprise from about 0.05 wt% to about 1.5 wt%, and in some embodiments, from about 0.1 wt% to about 0.5 wt%, of the polymer composition (by weight).

Of course, one beneficial aspect of the present invention is that good mechanical properties can be achieved without adversely affecting the dimensional stability of the resulting component. To help ensure that the dimensional stability is maintained, it is generally desirable that the polymer composition remain substantially free of conventional fibrous fillers such as glass fibers. Thus, if used, such fibers typically constitute no more than about 10 wt%, in some embodiments no more than about 5 wt%, and in some embodiments, from about 0.001 wt% to about 3 wt% of the polymer composition.

II.Shaping of

The aromatic polymer, friction formulation, and other optional additives may be melt processed or blended together. The components may be fed separately or in combination to an extruder that includes at least one screw rotatably mounted and housed within a barrel (e.g., a cylindrical barrel), and may define a feed section and a melt section downstream of the feed section along the length of the screw. The extruder may be a single screw or twin screw extruder. The screw speed may be selected to achieve a desired residence time, shear rate, melt processing temperature, and the like. For example, the screw speed may be from about 50 to about 800 revolutions per minute ("rpm"), in some embodiments from about 70 to about 150rpm, and in some embodiments, from about 80 to about 120 rpm. The apparent shear rate during melt blending may also be about 100s^-1To about 10000s^-1In some embodiments, about 500s^-1To about 5000s^-1And in some embodiments about 800s^-1To about 1200s^-1. Apparent shear rate equal to 4Q/pi R³Wherein Q is the volumetric flow rate of the polymer melt ("m)³And/s "), and R is the radius (" m ") of a capillary (e.g., an extruder die) through which the molten polymer flows.

Regardless of the particular manner in which it is shaped, the present inventors have discovered that the resulting polymer compositions can have excellent thermal properties. For example, the melt viscosity of the polymer composition may be sufficiently low that it can easily flow into the cavity of a mold having small dimensions. In a particular embodiment, the polymer composition may have a melt viscosity at 1000s of from about 1 to about 200 Pa-s, in some embodiments from about 5 to about 180 Pa-s, in some embodiments from about 10 to about 150 Pa-s, and in some embodiments, from about 60 to about 120 Pa-s^-1At a shear rate of. The melt viscosity can be measured according to ISO test No. 11443:2005 at a temperature 15 ℃ (e.g., 350 ℃) above the melting temperature of the composition.

III.Formed part

The shaped part may be formed from the polymer composition using a variety of different techniques. Suitable techniques may include, for example, injection molding, low pressure injection molding, extrusion compression molding, gas injection molding, foam injection molding, low pressure gas injection molding, low pressure foam injection molding, gas extrusion compression molding, foam extrusion compression molding, extrusion molding, foam extrusion molding, compression molding, foam compression molding, gas compression molding, and the like. For example, an injection molding system comprising a mold into which the polymer composition can be injected can be used. The time within the syringe can be controlled and optimized so that the polymer matrix is not pre-cured. When the cycle time is reached and the barrel is full for discharge, a piston may be used to inject the composition into the mold cavity. Compression molding systems may also be used. As with injection molding, the formation of the polymer composition into the desired article also occurs within the mold. The composition may be placed in the compression mold using any known technique, such as by being picked up by an automated robotic arm. The temperature of the mold may be maintained at or above the curing temperature of the polymer matrix for a desired period of time to allow curing. The molded product may then be solidified by bringing its temperature to a temperature below the melting temperature. The resulting product can be demolded. The cycle time of each molding process can be adjusted to accommodate the polymer matrix to achieve adequate bonding and increase overall process productivity.

Due to its high flowability, relatively thin shaped parts (e.g. injection molded parts) can be easily formed therefrom. For example, such components may have a thickness of about 10 millimeters or less, in some embodiments about 5 millimeters or less, and in some embodiments, about 0.2 to about 4 millimeters (e.g., 0.3 or 3 millimeters). When forming injection molded parts, for example, a relatively high "spiral flow length" can be achieved. The term "spiral flow length" generally refers to the length to which a composition flows in a spiral flow channel when the composition is injected from a central gate of a mold (in which the spiral flow channel is formed) at a constant injection temperature and injection pressure. The spiral flow length may be, for example, about 15 millimeters or more, in some embodiments about 20 millimeters or more, in some embodiments about 22 millimeters or more, and in some embodiments, from about 25 to about 80 millimeters, measured at a barrel temperature of 230 ℃, a molding temperature of 40 ℃ to 60 ℃, and a maximum injection pressure of 860 bars according to ASTM D3121-09.

The polymer composition may also maintain dimensional stability when formed into a part, and thus exhibit relatively low warpage. Warp can be characterized by a low "flatness value" as determined by the test described in more detail below. More particularly, the polymer composition may exhibit a flatness value of about 1 millimeter or less, in some embodiments about 0.8 millimeter or less, and in some embodiments, from about 0.1 to about 0.7 millimeter. The composition can also maintain such low warpage even after conditioning at high temperature and high humidity levels (e.g., 85 ℃ and 85% relative humidity) for a significant period of time (e.g., 72 hours). For example, after conditioning at 85 ℃/85% relative humidity for 72 hours, the polymer composition may still exhibit a flatness value of about 2 millimeters or less, in some embodiments about 1.5 millimeters or less, and in some embodiments, from about 0.1 to about 1.2 millimeters.

A wide variety of types of components can also be formed from the polymer compositions of the present invention. For example, the polymer composition may be used in lighting assemblies, battery systems, sensors and electronic components, portable electronic devices such as smart phones, MP3 players, mobile phones, computers, televisions, automotive components, and the like. In a particular embodiment, the polymer composition may be used in camera modules, such as those typically used in wireless communication devices (e.g., cellular telephones). For example, the camera module may use a base, a carrier assembly mounted to the base, a cover mounted to the carrier assembly, and the like. The base may have a thickness of about 500 microns or less, in some embodiments from about 10 to about 450 microns, and in some embodiments, from about 20 to about 400 microns. Likewise, the carrier component may have a wall thickness of about 500 microns or less, in some embodiments from about 10 to about 450 microns, and in some embodiments, from about 20 to about 400 microns.

A particularly suitable camera module is shown in fig. 1-2. As shown, the camera module 500 has a carrier assembly 504 superimposed on a base 506. The base 506 in turn overlies an optional motherboard 508. Due to its relatively thin nature, the base 506 and/or the motherboard 508 are particularly suitable for molding from the polymer compositions of the present invention. Carrier assembly 504 may have any of a variety of configurations known in the art. In one embodiment, for example, carrier assembly 504 may comprise a hollow cylinder containing one or more lenses 604, the lenses 604 being in communication with an image sensor 602 located on a motherboard 508 and controlled by circuitry 601. The barrel may have any of a variety of shapes, such as rectangular, cylindrical, etc. In certain embodiments, the barrel can be formed from the polymer composition of the present invention and have a wall thickness within the ranges described above. It is to be understood that other components of a camera module may also be formed from the polymer composition of the present invention. For example, as shown, a cover may overlie the carrier assembly 504, the cover including, for example, a substrate 510 (e.g., a membrane) and/or a thermally insulating cap 502. In some embodiments, the substrate 510 and/or the cap 502 may also be formed from the polymer composition.

The invention may be better understood by reference to the following examples.

Test method

Friction and wear: the degree of friction generated by the sample can be characterized by the average kinetic friction coefficient (dimensionless) determined using an SSP-03 machine (stick-slip test) according to VDA 230-. Likewise, the abrasion degree test of the sample can also be determined according to VDA 230-. More particularly, the spherical and plate-shaped test specimens were prepared via an injection molding process using the polymer product. The diameter of the spherical test piece was 0.5 inch. The plate-shaped test specimen was obtained from the middle portion of the ISO tensile bar by cutting both end regions of the tensile bar. The plate-shaped test specimen was fixed to the sample holder, and the spherical test specimen was moved in contact with the plate-shaped test specimen with a force of 150mm/s and 15N. After 1000 cycles, a dynamic friction coefficient was obtained. The depth of wear is obtained from a spherical sample by measuring the diameter of the spherical area worn away. Based on the diameter of the worn-out area, the depth of the worn-out spherical test piece was calculated and obtained.

Melt viscosity: melt viscosity (Pa s) can be measured according to ISO test No. 11443:2005 at a shear rate of 1000s^-1And a temperature 15 ℃ above the melting temperature (e.g., 350 ℃), as determined using a Dynisco L CR7001 capillary rheometer the rheometer orifice (die) has a diameter of 1mm, a length of 20mm, a L/D ratio of 20.1, and an entry angle of 180 DEG the barrel diameter is 9.55mm +0.005mm and the rod length is 233.4 mm.

Melting temperature: the melting temperature ("Tm") can be determined by differential scanning calorimetry ("DSC") as is known in the art. The melting temperature is the Differential Scanning Calorimetry (DSC) peak melt temperature as determined by ISO test number 11357-2: 2013. Under the DSC program, the samples were heated and cooled at 20 ℃/min using DSC measurements performed on a TA Q2000 instrument as described in ISO standard 10350.

Load deflection temperature ("DTU L"): load deflection temperature can be determined according to ISO test number 75-2:2013 (technically equivalent to ASTM D648-07.) more specifically, a test strip sample of 80mm length, 10mm thickness and 4mm width can be subjected to a three point bend along the edge test with a nominal load (maximum external fiber stress) of 1.8 MPa.

Tensile modulus, tensile stress and tensile elongation: tensile properties can be tested according to ISO test No. 527:2012 (technically equivalent to ASTM D638-14). Modulus and strength measurements can be made on the same test strip sample 80mm in length, 10mm in thickness and 4mm in width. The test temperature may be 23 ℃ and the test speed may be 1 or 5 mm/min.

Flexural modulus and flexural stress: flexural properties may be tested according to ISO test number 178:2010 (technically equivalent to ASTM D790-10). This test can be performed over a 64mm support span. The test can be performed on the center portion of an uncut ISO 3167 multipurpose bar. The test temperature may be 23 ℃ and the test speed may be 2 mm/min.

Impact strength of the unnotched and gapped simply supported beam: simple beam performance may be tested according to ISO test number ISO 179-1:2010) (technically equivalent to ASTM D256-10, method B). The test can be performed using type 1 specimen dimensions (length 80mm, width 10mm and thickness 4 mm). When testing notch impact strength, the notch can be an A-type notch (0.25mm base radius). A single tooth grinder may be used to cut out a sample from the center of a multi-purpose bar. The test temperature may be 23 ℃.

Rockwell hardness: rockwell hardness is a measure of indentation resistance of a material and can be measured according to ASTM D785-08 (Scale M). The test was performed by first forcing the steel ball indenter into the material surface using a nominal minimum load. The load is then increased to the nominal main load and decreased back to the initial minimum load. Rockwell hardness is a measure of the net increase in indenter depth and is calculated by subtracting the penetration divided by the scale division from 130.

Surface/volume resistivity: surface and volume resistivity values are typically determined according to IEC 60093 (similar to ASTM D257-07). According to this procedure, a standard sample (e.g. 1 cubic meter) is placed between two electrodes. Voltage was applied for sixty (60) seconds and resistance was measured. The surface resistivity is the quotient of the potential gradient (expressed in V/m) and the current per unit electrode length (expressed in a/m) and generally represents the resistance of the leakage current along the surface of the insulating material. Because the four (4) ends of the electrode define a square, the length in the quotient cancels out and the surface resistivity is recorded in ohms, although the more descriptive unit of ohms/square is also common. Volume resistivity is also determined as the ratio of the potential gradient parallel to the current in the material to the current density. In SI units, the volume resistivity is numerically equal to the direct current resistance (ohm-meters) between the opposing faces of a cubic meter of material.

The joint strength is as follows: seam strength can be determined as is well known in the art by first forming an injection molded compact camera module from a sample of the polymer composition. Once formed, the compact camera module can be placed on the sample holder. The seam of the die set can be passed by moving the bar at a speed of 5.08 mm/minThe tension is experienced. Can increase the maximum breaking force (kg)_f) Recorded as an estimate of the joint strength.

Spiral flow length: the term "spiral flow length" generally refers to the length to which a composition flows in a spiral flow channel (0.3 mm in thickness) when the composition is injected from a central gate of a mold in which the spiral flow channel is formed at a constant injection temperature and injection pressure. The spiral flow length can be determined according to ASTM D3121-09 at a barrel temperature of 230 ℃, a molding temperature of 40 ℃ to 60 ℃, and a maximum injection pressure of 860 bar.

Flatness value L flatness value (warp) of the GA connector sample can be measured using the OGP Smartscope Quest300 optical measurement system XYZ measurements can be taken along the specimen and started with X and Y values corresponding to 5, 22.5, 50, 57.5 and 75mm the Z values can be normalized so that the minimum Z value corresponds to zero height.

Example 1

Samples 1-6 were prepared from various percentages of liquid crystalline polymer, barium sulfate, impact modifier: (8840) Friction formulation, black masterbatch and antistatic filler formation, as shown in table 1 below. The friction formulation comprises a high molecular weight siloxane polymer (Pellet S) and fluorinated additive (Thor FPz mica) Black masterbatch contains 80% by weight of liquid crystalline polymer and 20% by weight of carbon black the antistatic filler is an ionic liquid, i.e. tri-n-butyl methylammonium bis (trifluoromethanesulfonyl) -imide (FC-4400, from 3M.) the liquid crystalline polymer (L CP 1) in samples 1-4 is formed from HBA, HNA, TA, BP and APAP, such asL ee et alAnd the liquid crystalline polymer (L CP 2) in samples 5-6 was formed from HBA, HNA and TA compounding was performed using an 18mm single screw extruder, the part was injection molded into a slab (60mm × mm).

TABLE 1

Samples 1-3 and 5-6 were also tested for thermal, mechanical and wear properties. The results are set forth in table 2 below.

TABLE 2