Polymer composition for use in a camera module
A camera module comprising a polymer composition that includes a polymer matrix containing a liquid crystalline polymer and a mineral filler is provided. The liquid crystalline polymer contains repeating units derived from naphthenic hydroxycarboxylic and/or dicarboxylic acids in an amount of about 10 mol. % or more of the polymer. Further, the polymer composition exhibits a melt viscosity of from about 30 to about 400 Pa-s, as determined at a shear rate of 400 seconds −1 and at a temperature 15° C. higher than the melting temperature of the composition in accordance with ISO Test No. 11443:2005.
1. A camera module comprising a polymer composition that includes a polymer matrix containing a liquid crystalline polymer and a mineral filler, wherein the liquid crystalline polymer contains repeating units derived from naphthenic hydroxycarboxylic and/or dicarboxylic acids in an amount of about 10 mol. % or more of the polymer, and further wherein the polymer composition exhibits a melt viscosity of from about 30 to about 400 Pa-s, as determined at a shear rate of 400 seconds −1 and at a temperature 15° C. higher than the melting temperature of the composition in accordance with ISO Test No. 11443:2005.
2. The camera module of claim 1 , wherein the polymer composition exhibits a flexural modulus of about 7,000 MPa or more as determined in accordance with ISO Test No. 178:2010 at 23° C.
3. The camera module of claim 1 , wherein the polymer composition exhibits a Rockwell surface hardness of about 25 or more as determined in accordance with ASTM D785-08 (Scale M).
4. The camera module of claim 1 , wherein the polymer composition exhibits a Charpy unnotched impact strength of about 2 kJ/m 2 as determined at 23° C. according to ISO Test No. 179-1:2010.
5. The camera module of claim 1 , wherein the polymer composition exhibits a tensile strength of from about 20 to about 500 MPa, a tensile break strain of about 0.5% or more, and/or a tensile modulus of from about 5,000 MPa to about 30,000 MPa, as determined in accordance with ISO Test No, 527:2012.
6. The camera module of claim 1 , wherein the polymer composition exhibits a dynamic coefficient of friction of about 1.0 or less and/or a wear depth of about 500 micrometers or less, as determined in accordance with VDA 230-206:2007.
7. The camera module of claim 1 , wherein the polymer matrix constitutes from about 20 wt. % to about 70 wt. % of the polymer composition.
8. The camera module of claim 1 , wherein the liquid crystalline polymer has a melting temperature of about 200° C. or more.
9. The camera module of claim 1 , wherein the liquid crystalline polymer contains one or more repeating units derived from a hydroxycarboxylic acid, wherein the hydroxycarboxylic acid repeating units constitute about 50 mol. % or more of the polymer.
10. The camera module of claim 9 , wherein the liquid crystalline polymer contains repeating units derived from 4-hydroxybenzoic acid, 6-hydroxy-2-napthoic acid, or a combination thereof.
11. The camera module of claim 10 , wherein the liquid crystalline polymer contains repeating units derived from 4-hydroxybenzoic acid in an amount of from about 50 mol. % to about 90 mol. % of the polymer and contains repeating units derived from 6-hydroxy-2-napthoic acid in amount of from about 10 mol. % to about 50 mol. % of the polymer.
12. The camera module of claim 10 , wherein the liquid crystalline polymer further contains repeating units derived from terephthalic acid, isophthalic acid, 2,6-naphthalenedicarboxylic acid, hydroquinone, 4,4′-biphenol, acetaminophen, 4-aminophenol, or a combination thereof.
13. The camera module of claim 8 , wherein the polymer composition further comprises a semi-crystalline polyester that includes poly(ethylene terephthalate), poly(1,4-butylene terephthalate), poly(1,3-propylene terephthalate), poly(1,4-butylene 2,6-naphthalate), poly(ethylene 2,6-naphthalate), poly(1,4-cyclohexylenedimethylene terephthalate), a derivative of any of the foregoing, or a combination thereof.
14. The camera module of claim 13 , wherein liquid crystalline polymers constitute from about 15 wt. % to about 85 wt. % of the polymer composition and semi-crystalline polyesters constitute from about 1 wt. % to about 50 wt. % of the polymer composition.
15. The camera module of claim 1 , wherein mineral fillers constitute from about 20 to about 100 parts by weight per 100 parts by weight of the polymer matrix.
16. The camera module of claim 1 , wherein the mineral filler has a hardness value of about 2.0 or more based on the Mohs hardness scale.
17. The camera module of claim 1 , wherein the mineral filler contains mineral particles, mineral fibers, or a combination thereof.
18. The camera module of claim 17 , wherein the mineral particles have a median diameter of from about 0.5 to about 20 micrometers.
19. The camera module of claim 17 , wherein the mineral particles contain barium sulfate, calcium sulfate, silica, or a combination thereof.
20. The camera module of claim 17 , wherein the mineral particles are flaked-shaped particles having an aspect ratio of about 4 or more.
21. The camera module of claim 17 , wherein the mineral particles include mica.
22. The camera module of claim 17 , wherein the mineral fibers include wollastonite fibers.
23. The camera module of claim 1 , wherein the polymer composition contains a blend of mineral particles and mineral fibers, wherein mineral fibers constitute about 1 wt. % to about 40 wt. % of the polymer composition and mineral particles constitute from about 2 wt,% to about 50 wt. % of the polymer composition.
24. The camera module of claim 1 , wherein the polymer composition is generally free of glass fibers.
25. The camera module of claim 1 , wherein the polymer composition contains an impact modifier.
26. The camera module of claim 25 , wherein the impact modifier includes an olefin polymer.
27. The camera module of claim 25 , wherein the olefin polymer is a copolymer that contains a (meth)acrylic monomeric unit.
28. The camera module of claim 1 , wherein the polymer composition contains an antistatic filler.
29. The camera module of claim 1 , wherein the polymer composition contains a tribological formulation, lubricant, thermally conductive filler, pigment, antioxidant, stabilizer, surfactant, wax, flame retardant, anti-drip additive, nucleating agent, or a combination thereof.
30. The camera module of claim 1 , wherein the camera module comprises:
a housing within which a lens module is positioned that contains one or more lenses; and
optionally, an actuator assembly that is configured to drive the lens module in an optical axis direction;
wherein at least a portion of the housing, lens module, actuator assembly, or a combination thereof contains the polymer composition.
31. The camera module of claim 30 , wherein the actuator assembly optionally includes a guide unit that is positioned between the housing and the lens module, wherein the guide unit includes a spring, ball bearing, electrostatic force generator, hydraulic force generator, or a combination thereof.
32. The camera module of claim 31 , wherein at least a portion of the guide unit contains the polymer composition.
33. The camera module of claim 31 , wherein the guide unit contains a ball bearing.
34. The camera module of claim 33 , wherein the ball bearing has an average size of about 800 micrometers or less.
35. The camera module of claim 1 , wherein polymer composition exhibits a dent of about 50 micrometers or less when contacted with a metal ball having a diameter of 1.5 mm and weight of 75 grams that is dropped from a height of 15 centimeters into contact with the polymer composition.
36. An electronic device comprising the camera module of claim 1 .
37. The electronic device of claim 36 , wherein the device is a wireless communication device.