阅读说明：本技术 紧凑型摄像模组 (Compact camera module ) 是由 金荣申 于 2013-10-14 设计创作，主要内容包括：提供了紧凑型摄像模组,其包括上面安装有镜筒的通常平坦的基座。所述基座、筒或二者由聚合物组合物的模制,所述聚合物组合物包含热致液晶聚合物和多个矿物纤维(也称为“晶须”)。所述矿物纤维具有约1至约35微米的中值宽度,并占所述聚合物组合物的约5重量％至约60重量％。(A compact camera module is provided that includes a generally planar base on which a lens barrel is mounted. The base, barrel, or both are molded from a polymer composition comprising a thermotropic liquid crystalline polymer and a plurality of mineral fibers (also referred to as "whiskers"). The mineral fibers have a median width of from about 1 to about 35 microns and comprise from about 5% to about 60% by weight of the polymer composition.)

1. A compact camera module comprising a molded part having a thickness of 500 microns or less and molded from a polymer composition comprising a thermotropic liquid crystalline polymer and a plurality of mineral fibers, wherein the mineral fibers have a median width of 1 to 35 microns, an aspect ratio of 4 to 15, and constitute 5 to 60 weight percent of the polymer composition, wherein the liquid crystalline polymer constitutes 55 to 80 weight percent of the polymer composition, and wherein the polymer composition exhibits a tensile strength of 100 to 350MPa, as determined according to ISO test No. 527 at 23 ℃.

2. The compact camera module of claim 1, wherein the thickness is 100 to 450 micrometers.

3. The compact camera module of claim 1 or 2, wherein the liquid crystal polymer comprises aromatic ester repeat units.

4. The compact camera module of claim 3, wherein the aromatic ester repeat units are aromatic dicarboxylic acid repeat units, aromatic hydroxycarboxylic acid repeat units, or a combination thereof.

5. The compact camera module of claim 3, wherein the polymer further comprises aromatic diol repeating units.

6. The compact camera module of claim 1 or 2, wherein the liquid crystal polymer comprises repeating units derived from 4-hydroxybenzoic acid, terephthalic acid, hydroquinone, 4' -biphenol, acetaminophen, 6-hydroxy-2-naphthoic acid, 2, 6-naphthalenedicarboxylic acid, or a combination thereof.

7. The compact camera module of claim 1 or 2, wherein at least 60 volume% of the mineral fibers have a diameter of 1 to 35 microns.

8. The compact camera module of claim 1 or 2, wherein the mineral fibers have a median width of 3 to 15 micrometers.

9. The compact camera module of claim 1 or 2, wherein the mineral fibers comprise fibers derived from silicates.

10. The compact camera module of claim 9, wherein the silicate is an inosilicate.

11. The compact camera module of claim 10, wherein the inosilicate comprises wollastonite.

12. The compact camera module of claim 1 or 2, wherein the polymer composition further comprises a sulfate.

13. The compact camera module of claim 1 or 2, further comprising conductive fillers, glass fillers, clay minerals, or combinations thereof.

14. The compact camera module of claim 1 or 2, further comprising a functional compound.

15. The compact camera module of claim 14, wherein the functional compound comprises an aromatic compound that is an aromatic diol, an aromatic carboxylic acid, or a combination thereof.

16. The compact camera module of claim 14, wherein the functional compound comprises a non-aromatic compound that is a hydrate.

17. The compact camera module of claim 1 or 2, wherein the composition has a standard ISO test number 11443 of 0.1 to 80 Pa-s at 1000 seconds^-1And a melt viscosity measured at a temperature 15 ℃ above the melting temperature of the composition.

18. The compact camera module of claim 1 or 2, wherein the molded part has a surface gloss of 35% or greater at an incident light angle of 85 °.

19. The compact camera module of claim 1, wherein the polymer composition comprises fibers selected from the group consisting of nesosilicates, sorosilicates, inosilicates, phyllosilicates, tectosilicates, sulfate salts, and mineral wool.

Background

Compact camera modules ("CCMs") are commonly used for mobile phones, notebook computers, digital cameras, digital video cameras, and the like that include a plastic lens barrel mounted on a base. Because conventional plastic lenses cannot withstand reflow soldering, camera modules are typically not surface mounted. However, attempts have been made to use liquid crystal polymers having high heat resistance for molded parts of compact camera modules such as lens barrels or bases on which the lens barrels are mounted. In order to improve the mechanical properties of such polymers, it is known to add plate-like substances (e.g. talc) and milled glass. Although strength and modulus of elasticity can be improved in this manner, problems are still encountered when attempting to use such materials for compact camera modules due to their small dimensional tolerances. For example, mechanical properties are often poor or non-uniform, which results in poor filling and lack of dimensional stability in molded parts. In addition, increasing the amount of ground glass to improve mechanical properties can result in an overly rough surface, which can lead to errors in camera performance and sometimes cause undesirable particulate generation.

There is also a need for a polymer composition that can be easily used for molded parts of compact camera modules and that also achieves good mechanical properties.

Brief description of the invention

According to one embodiment of the present invention, a compact camera module is disclosed that includes a generally planar base on which a lens barrel is mounted. The base, barrel, or both have a thickness of about 500 microns or less and are molded from a polymer composition comprising a thermotropic liquid crystalline polymer and a plurality of mineral fibers. The mineral fibers have a median width of from about 1 to about 35 microns and comprise from about 5% to about 60% by weight of the polymer composition.

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

Brief description of the 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 may be formed according to one embodiment of the present invention.

FIG. 3 is a schematic representation of one embodiment of an extruder screw that can be used to form the polymer composition of the present invention.

Detailed Description

It is to be understood by one of ordinary skill in the art that the present discussion is a description of exemplary embodiments only, and is not intended as limiting the broader aspects of the present invention.

The present invention relates generally to compact camera modules ("CCMs"), such as those commonly used in wireless communication devices (e.g., cellular telephones). The camera module includes a generally planar base on which a lens barrel is mounted. The base and/or barrel is formed from a polymer composition comprising a liquid crystal polymer and a plurality of mineral fibers (also referred to as "whiskers"). Examples of such mineral fibers include, for example, those derived from: silicates such as nesosilicates, sorosilicates, inosilicates (e.g., calcium inosilicates such as wollastonite; calcium magnesium inosilicates such as tremolite; calcium magnesium iron chain silicates such as actinolite; magnesium iron chain silicates such as rectennite, etc.), layered silicates (e.g., aluminum layered silicates such as palygorskite), network silicates, and the like; sulfates such as calcium sulfate (e.g., dehydrated or anhydrous gypsum); mineral wool (e.g., rock wool or slag wool), and the like. Particularly suitable are inosilicates such as wollastonite fibers, which may be available under the trade name Nyco Minerals(e.g. in4W or8) And (4) obtaining.

The mineral fibers may have a median width (e.g., diameter) of from about 1 to about 35 microns, in some embodiments from about 2 to about 20 microns, in some embodiments from about 3 to about 15 microns, in some embodiments from about 7 to about 12 microns. The mineral fibers may also have a narrow size distribution. That is, at least about 60% by volume of the fibers, in some embodiments at least about 70% by volume of the fibers, and in some embodiments at least about 80% by volume of the fibers can have a size within the above-described ranges. Without wishing to be bound by theory, it is believed that mineral fibers having the above dimensional characteristics can move more easily through the molding apparatus, which enhances distribution within the polymer matrix and minimizes the generation of surface defects. In addition to having the above dimensional characteristics, the mineral fibers may also have a relatively high aspect ratio (average length divided by median width) to help further improve the mechanical properties and surface quality of the resulting polymer composition. For example, the mineral fibers may have an aspect ratio of from about 1 to about 50, in some embodiments from about 2 to about 20, and in some embodiments, from about 4 to about 15. The volume average length of such mineral fibers may range, for example, from about 1 to about 200 microns, in some embodiments from about 2 to about 150 microns, in some embodiments from about 5 to about 100 microns, and in some embodiments, from about 10 to about 50 microns.

By using a liquid crystalline polymer and mineral fibres of the size indicated above, the present inventors have found that the resulting polymer composition is capable of achieving good strength and a smooth surface, which makes it uniquely suitable for small moulded parts of compact camera modules. For example, the base may have a thickness of about 500 microns or less, in some embodiments from about 100 to about 450 microns, and in some embodiments, from about 200 to about 400 microns. Also the lens barrel may have a wall thickness of about 500 microns or less, in some embodiments from about 100 to about 450 microns, and in some embodiments, from about 200 to about 400 microns. When formed from the polymer compositions of the present invention, the ratio of the thickness of the base and/or barrel to the volume average length of the mineral fibers may be from about 1 to about 50, in some embodiments from about 2 to about 30, and in some embodiments, from about 5 to about 15.

The relative amount of the mineral fibers in the polymer composition is also selectively controlled to help achieve desired mechanical properties without negatively affecting other properties of the composition such as its smoothness when formed into a molded part. For example, mineral fibers typically constitute from about 5% to about 60%, in some embodiments from about 10% to about 50%, and in some embodiments, from about 20% to about 40% by weight of the polymer composition. In addition to fibers, the polymer composition of the present invention uses at least one thermotropic liquid crystalline polymer having a high crystallinity that enables it to effectively fill a small space of a mold for forming a base and/or a lens barrel of a compact camera module. While the concentration of the liquid crystalline polymers may generally vary based on the presence of other optional components, they are typically present in an amount of from about 25% to about 95% by weight, in some embodiments from about 30% to about 80% by weight, and in some embodiments, from about 40% to about 70% by weight.

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

I. Liquid crystalline polymers

Thermotropic liquid crystalline polymers typically have a high degree of crystallinity that allows them to effectively fill the small spaces of the mold. Suitable thermotropic liquid crystalline polymers can include aromatic polyesters, aromatic poly (ester amides), aromatic poly (ester carbonates), aromatic polyamides, and the like, and can likewise contain repeating units formed from one or more aromatic hydroxycarboxylic acids, aromatic dicarboxylic acids, aromatic diols, aromatic aminocarboxylic acids, aromatic amines, aromatic diamines, and the like, as well as combinations thereof.

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 state). 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 comprise one or more aromatic ester repeat units in an amount of from about 60 mole% to about 99.9 mole%, in some embodiments from about 70 mole% to about 99.5 mole%, and in some embodiments, from about 80 mole% to about 99 mole% of the polymer. The aromatic ester repeat units may be generally represented by the following formula (I):

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

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

Typically, Y₁And Y₂At least one of (a) is C (O). Examples of such aromatic ester repeating units may include, for example, aromatic dicarboxylic acid repeating units (Y in formula I)₁And Y₂Is C (O), an aromatic hydroxycarboxylic acid repeating unit (Y in formula I)₁Is O and Y₂C (O)) and various combinations thereof.

For example, aromatic dicarboxylic acid 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") and 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 comprise 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, 4-hydroxy-4 '-bibenzoic 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, as well as alkyl, alkoxy, aryl, and halogen substituents thereof, and combinations thereof, may also be used. 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 mole% to about 85 mole%, in some embodiments from about 20 mole% to about 80 mole%, and in some embodiments, from about 25 mole% to about 75 mole% of the polymer.

Other repeat units may also be used in 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, as well as 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' -biphenol ("BP"). When used, the repeat units derived from aromatic diols (e.g., HQ and/or BP) typically comprise from about 1 mole% to about 30 mole%, in some embodiments from about 2 mole% to about 25 mole%, and in some embodiments, from about 5 mole% 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 comprise from about 0.1 mole% to about 20 mole%, in some embodiments from about 0.5 mole% to about 15 mole%, and in some embodiments, from about 1 mole% to about 10% of the polymer. It is also understood that various other monomeric repeat units may be incorporated into the polymer. For example, in certain embodiments, the polymer may comprise 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 "wholly 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 more than 30 mole%, in some embodiments no more than about 15 mole%, and in some embodiments no more than about 10 mole%, in some embodiments no more than about 8 mole%, and in some embodiments from 0 mole% to about 5 mole% (e.g., 0 mole%) of the polymer. Despite the absence of 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"), as well as various other optional components. The repeat units derived from 4-hydroxybenzoic acid ("HBA") may comprise from about 10 mole% to about 80 mole%, in some embodiments from about 30 mole% to about 75 mole%, and in some embodiments, from about 45 mole% to about 70% of the polymer. Repeat units derived from terephthalic acid ("TA") and/or isophthalic acid ("IA") may likewise comprise from about 5 mole% to about 40 mole%, in some embodiments, from about 10 mole% to about 35 mole%, and in some embodiments, from about 15 mole% to about 35% of the polymer. Repeat units derived from 4,4' -biphenol ("BP") and/or hydroquinone ("HQ") may also be used in amounts of from about 1 to about 30, in some embodiments from about 2 to about 25, and in some embodiments, from about 5 to about 20 mole percent of the polymer. Other possible repeat units may include those derived from 6-hydroxy-2-naphthoic acid ("HNA"), 2, 6-naphthalene dicarboxylic acid ("NDA"), and/or acetaminophen ("APAP"). When used, in certain embodiments, for example, the repeat units derived from HNA, NDA, and/or APAP may each comprise from about 1 mole% to about 35 mole%, in some embodiments, from about 2 mole% to about 30 mole%, and in some embodiments, from about 3 mole% to about 25 mole%.

Regardless of the particular components and nature of the polymer, the liquid crystal composition may be prepared by first introducing one or more aromatic monomers (e.g., aromatic hydroxycarboxylic acids, aromatic dicarboxylic acids, etc.) and/or other repeating units (e.g., aromatic diols, aromatic amides, aromatic amines, etc.) used to form the ester repeating units into a reaction vessel to initiate the polycondensation reaction. The specific conditions and procedures used in such reactions are well known and can be described in more detail in U.S. patent nos. 4,161,470; U.S. patent No. 5,616,680 to linstid.iii et al; U.S. patent No. 6,114,492 to linstid.iii et al; U.S. Pat. No. 6,514,611 to Shepherd et al and WO 2004/058851 to Waggoner. The vessel used for the reaction is not particularly limited, but it is typically desirable to use a vessel generally used for the reaction of a highly viscous fluid. Examples of such a reaction vessel may include a stirring tank type apparatus having a stirrer having a variable-shaped stirring blade such as an anchor type, a multistage type, a helical ribbon type, a helical shaft type, etc., or a modified shape thereof. Other examples of such a reaction vessel may include mixing devices commonly used for resin kneading such as a kneader, a roll kneader, a banbury mixer, and the like.

The reaction may be carried out by acetylation of monomers known in the art, if desired. This can be accomplished by adding an acetylating agent (e.g., acetic anhydride) to the monomer. Acetylation is typically initiated at a temperature of about 90 ℃. Reflux may be employed during the initial stages of acetylation to maintain the vapor phase temperature below the point at which distillation of acetic acid by-product and anhydride begins. The temperature during acetylation is typically in the range of 90 ℃ to 150 ℃, in some embodiments from about 110 ℃ to about 150 ℃. If reflux is used, the vapor phase temperature typically exceeds the boiling point of acetic acid, but remains low enough to retain residual acetic anhydride. For example, acetic anhydride is evaporated at a temperature of about 140 ℃. It is therefore particularly desirable to provide a reactor having a vapor phase that is refluxed at a temperature of about 110 ℃ to about 130 ℃. To ensure substantially complete reaction, an excess of acetic anhydride may be used. The amount of excess anhydride will vary depending on the particular acetylation conditions used (including the presence or absence of reflux). It is not uncommon to use an excess of about 1 to about 10 mole percent acetic anhydride, based on the total moles of reactant hydroxyl groups present.

The acetylation may occur in a separate reaction vessel, or may occur in situ in the polymerization reaction vessel. When a separate reaction vessel is used, one or more monomers may be introduced into the acetylation reactor and subsequently transferred to the polymerization reactor. Likewise, it is also possible to introduce one or more monomers directly into the reaction vessel without prior acetylation.

In addition to the monomers and optional acetylating agent, other components may be included in the reaction mixture to help promote polymerization. For example, a catalyst such as a metal salt catalyst (e.g., magnesium acetate, tin (I) acetate, tetrabutyl titanate, lead acetate, sodium acetate, potassium acetate, etc.) and an organic compound catalyst (e.g., N-methylimidazole) may be optionally used. Such catalysts are typically used in amounts of about 50 to about 500ppm based on the total weight of the repeating unit precursor. When a separate reactor is used, it is typically desirable to apply the catalyst to the acetylation reactor rather than the polymerization reactor, although this is by no means a requirement.

The reaction mixture is typically heated to an elevated temperature in the polymerization reaction vessel to initiate melt polycondensation of the reactants. For example, polycondensation may occur at a temperature in the range of from about 250 ℃ to about 400 ℃, in some embodiments from about 280 ℃ to about 395 ℃, and in some embodiments, from about 300 ℃ to about 380 ℃. For example, one suitable technique for forming the liquid crystalline polymer may include feeding precursor monomers and acetic anhydride into a reactor, heating the mixture to a temperature of about 90 ℃ to about 150 ℃ to acetylate the hydroxyl groups of the monomers (e.g., to form acetoxy groups), and then raising the temperature to about 250 ℃ to about 400 ℃ to perform melt polycondensation. Volatile by-products of the reaction (e.g., acetic acid) can also be removed as the final polymerization temperature is approached, so that the desired molecular weight can be easily obtained. During the polymerization, the reaction mixture is usually stirred to ensure good heat and mass transfer and thus good material homogeneity. The rate of rotation of the stirrer may vary during the reaction, but typically ranges from about 10 to about 100 revolutions per minute ("rpm") and in some embodiments from about 20 to about 80 rpm. In order to build molecular weight in the melt, the polymerization reaction can also be carried out under vacuum, the application of which helps to remove the volatiles formed during the final stages of polycondensation. The vacuum may be created by applying a suction pressure, for example, in the range of about 5 to about 30 pounds per square inch ("psi") and in some embodiments, about 10 to about 20 psi.

After melt polymerization, the molten polymer may be discharged from the reactor, typically through an extrusion orifice equipped with a die of the desired configuration, cooled and collected. Typically, the melt is discharged through a perforated die to form a collected strand in a water bath, pelletized and dried. In some embodiments, the melt polymerized polymer may also be subjected to a subsequent solid state polymerization process to further increase its molecular weight. The solid state polymerization may be carried out in the presence of a gas (e.g., air, inert gas, etc.). Suitable inert gases may include, for example, nitrogen, helium, argon, neon, krypton, xenon, and the like, as well as combinations thereof. The solid state polymerization reaction vessel can be of virtually any design that allows for the desired residence time of the polymer at the desired solid state polymerization temperature. Examples of such vessels may be those having a fixed bed, a stationary bed, a moving bed, a fluidized bed, and the like. The temperature at which the solid state polymerization is carried out may vary, but is typically in the range of from about 250 ℃ to about 350 ℃. Of course, the polymerization time will vary based on the temperature and the target molecular weight. However, in most cases, the solid state polymerization time will be in the range of from about 2 to about 12 hours and in some embodiments from about 4 to about 10 hours.

Optional Components

A. Conductive filler

If desired, electrically conductive fillers may be used in the polymer composition to help reduce the tendency for static electricity to develop during the molding operation. In fact, the inventors have found that the presence of a controlled size and amount of said mineral fibres, as indicated above, can enhance the ability of the conductive filler to be dispersed in said liquid crystalline polymer matrix, thereby allowing the use of relatively low concentrations of said conductive filler to achieve the desired electrostatic properties. However, because it is used in a relatively low concentration, the impact on thermal and mechanical properties can be minimized. In this aspect, when used, the electrically conductive filler typically comprises from about 0.1% to about 25%, in some embodiments from about 0.3% to about 10%, in some embodiments from about 0.4% to about 3%, and in some embodiments, from about 0.5% to about 1.5% by weight of the polymer composition.

Any of a variety of conductive fillers can generally be used in the polymer composition to help improve its electrostatic properties. Examples of suitable conductive fillers 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, so they have a relatively high carbon content, such as a carbon content of about 85% by weight or greater, in some embodiments about 90% by weight or greater and in some embodiments about 93% by weight 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%, such as less than about 99 wt%. The carbon fibers typically have a density of about 0.5 to about 3.0g/cm³In some embodiments from about 1.0 to about 2.5g/cm³And in some embodiments 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 can typically be from 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 fibers may have an average diameter of 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 within 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 crystal polymer. The sizing agent may be stable so 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 may have a thermal decomposition temperature greater than about 300 ℃, such as greater than about 350 ℃, such as 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). The sizing agent may also have a relatively high glass transition temperature. For example, the glass transition temperature of the sizing agent may be greater than about 300 ℃, such as greater than about 350 ℃, such as greater than about 400 ℃. 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.%. The sizing agent is typically present in an amount of less than about 5 wt.%, such as in an amount of less than about 3 wt.%.

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

The ionic liquid is typically a salt having a sufficiently low melting temperature so that it can be in liquid form when melt processed with the liquid crystalline polymer. For example, the ionic liquid may have a melting temperature of 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 comprises a cationic species and a counter ion. The cationic species comprises as a "cationic center" a compound having at least one heteroatom (e.g., nitrogen or phosphorus). Examples of such heteroatom compounds include, for example, quaternary phosphonium compounds having the structure

Ammonium saltPyridine compoundPyridazinePyrimidinesPyrazine esters

ImidazolePyrazolesAzole

1,2, 3-triazoles1,2, 4-triazoles

ThiazolesQuinolinesIsoquinoline derivativesPiperidine derivativesPyrrolines

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., ethenyl, propenyl, 2-methylpropenyl, pentenyl, 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, triazolyl, imidazolyl, isothiazolylOxazolyl, 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 R is¹、R²And R³Is butyl, and R⁴Is methyl.

Suitable counter ions for 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 group; 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., tetrachloroaluminates); fatty acid carboxylates (e.g., oleate, isostearate, pentadecafluorooctanoate, etc.); cyanate radical; acetate, and the like, as well as combinations of any of the foregoing. To help improve compatibility with the liquid crystalline polymer, it may be desirable to select counter ions that are generally hydrophobic in nature, such as imides, fatty acid carboxylates, and the like. Particularly suitable hydrophobic counterions can include, for example, bis (pentafluoroethylsulfonyl) imide, bis (trifluoromethylsulfonyl) imide and bis (trifluoromethyl) imide.

In certain embodiments, a synergistic effect may be achieved by using the ionic liquid in combination with a carbon filler (e.g., graphite, carbon fiber, etc.). Without wishing to be bound by theory, the present invention believes that the ionic liquid can flow easily during melt processing to help provide better connection and electrical pathways between the carbon filler and the liquid crystalline polymer matrix, thereby further reducing surface resistance.

B.Glass filler

Glass fillers, which are not generally electrically conductive, may also be used in the polymer composition to help improve strength. For example, the glass filler may comprise from about 2% to about 40%, in some embodiments from about 5% to about 35%, and in some embodiments, from about 6% to about 30% by weight of the polymer composition. Glass fibers are particularly suitable for use in the present invention, such as those formed from E-glass, A-glass, C-glass, D-glass, AR-glass, R-glass, S1-glass, S2-glass, and the like, and mixtures thereof. The median width of the glass fibers may be relatively small, such as from about 1 to about 35 microns, in some embodiments from about 2 to about 20 microns, and in some embodiments, from about 3 to about 10 microns. When used, it is believed that the small diameter of such glass fibers may make their length more susceptible to reduction during melt blending, which may further improve surface appearance and mechanical properties. In molded parts, for example, the volume average length of the glass fibers may be relatively small, such as from about 10 to about 500 micrometers, in some embodiments from about 100 to about 400 micrometers, in some embodiments from about 150 to about 350 micrometers, and in some embodiments, from about 200 to about 325 micrometers. The glass fibers may also have a relatively high aspect ratio (average length divided by nominal diameter), such as from about 1 to about 100, in some embodiments from about 10 to about 60, and in some embodiments, from about 30 to about 50.

C.Particulate filler

Particulate fillers, which are generally non-conductive, may also be used in the polymer composition to help achieve desired properties and/or color. When used, such particulate fillers typically constitute from about 5% to about 40%, in some embodiments, from about 10% to about 35%, and in some embodiments, from about 10% to about 30% by weight of the polymer composition. Particulate clay minerals may be particularly suitable for use in the present invention. Examples of such clay minerals include, for example, talc (Mg)₃Si₄O₁₀(OH)₂) Halloysite (Al)₂Si₂O₅(OH)₄) Kaolin (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) And the like, as well as combinations thereof. Other particulate fillers may also be used instead of or in addition to clay minerals. For example, other suitable particulate silicate fillers such as mica, diatomaceous earth, and the like may also be employed. For example, mica may be a particularly suitable mineral for use in the present invention. As used herein, the term "mica" refers to the generic inclusion of any of these materials: 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 (Li, Al)_2-3(AlSi₃)O₁₀(OH)₂) Glauconite (K, Na) (Al, Mg, Fe)₂(Si,Al)₄O₁₀(OH)₂) And the like, as well as combinations thereof.

D.Functional compounds

If desired, functional compounds may also be used in the present invention, particularly to help reduce the melt viscosity of the polymer composition. In one embodiment, for example, the polymer composition of the present invention may comprise a functional aromatic compound. Such compounds typically contain one or more carboxyl and/or hydroxyl functional groups that are capable of reacting with the polymer chain to shorten its length, thus reducing the melt viscosity. In some cases, the compound may be capable of bonding shorter chains of the polymer together even after the melt viscosity of the composition has been reduced after the shorter chains of the polymer have been cut to help maintain the mechanical properties of the polymer. The functional aromatic compound may have the general structure provided below in formula (II) or a metal salt thereof:

wherein

Ring B is a 6-membered aromatic ring, wherein 1 to 3 ring carbon atoms are optionally replaced by nitrogen or oxygen, wherein each nitrogen is optionally oxidized, and wherein ring B may be optionally fused or connected to a 5-or 6-membered aryl, heteroaryl, cycloalkyl or heterocyclyl group;

R₄is OH or COOH;

R₅is acyl, acyloxy (e.g., acetoxy), acylamino (e.g., acetamido), alkoxy, alkenyl, alkyl, amino, aryl, aryloxy, carboxyl ester, cycloalkyl, cycloalkyloxy, hydroxyl, halo, haloalkyl, heteroaryl, heteroaryloxy, heterocyclyl, or heterocyclyloxy;

m is from 0 to 4, in some embodiments from 0 to 2, and in some embodiments from 0 to 1; and

n is 1 to 3, and in some embodiments 1 to 2. When the compound is in the form of a metal salt, suitable metal counterions can include transition metal counterions (e.g., copper, iron, etc.), alkali metal counterions (e.g., potassium, sodium, etc.), alkaline earth metal counterions (e.g., calcium, magnesium, etc.), and/or main group metal counterions (e.g., aluminum).

In one embodiment, for example in formula (II) B is phenyl, whereby the resulting phenolic compound has the following general formula (III) or a metal salt thereof:

wherein

R₄Is OH or COOH;

R₆is acyl, acyloxy, acylamino, alkoxy, alkenyl, alkyl, amino, carboxyl ester, hydroxyl, halogen or halogenated alkyl; and

q is from 0 to 4, in some embodiments from 0 to 2, and in some embodiments from 0 to 1. Specific examples of such phenol compounds include, for example, benzoic acid (q is 0); 4-hydroxybenzeneAcid (R)₄Is COOH, R₆Is OH and q is 1); phthalic acid (R)₄Is COOH, R₆Is COOH and q is 1); isophthalic acid (R)₄Is COOH, R₆Is COOH and q is 1); terephthalic acid (R)₄Is COOH, R₆Is COOH and q is 1); 2-Methylphthalic acid (R)₄Is COOH, R₆Is COOH and CH₃And q is 2); phenol (R)₄Is OH and q is 0); sodium phenolate (R)₄Is OH and q is 0); hydroquinone (R)₄Is OH, R₆Is OH and q is 1); resorcinol (R)₄Is OH, R₆Is OH and q is 1); 4-hydroxybenzoic acid (R)₄Is OH, R₆C (O) OH and q is 1), and the like, and combinations thereof.

In another embodiment, in formula (II) above, B is phenyl and R is₅Is phenyl such that the diphenol compound has the following general formula (IV), or a metal salt thereof:

wherein

R₄Is COOH or OH;

R₆is acyl, acyloxy, acylamino, alkoxy, alkenyl, alkyl, amino, aryl, aryloxy, carboxyl ester, cycloalkyl, cycloalkoxy, hydroxyl, halo, haloalkyl, heteroaryl, heteroaryloxy, heterocyclyl or heterocycloxy; and

q is from 0 to 4, in some embodiments from 0 to 2, and in some embodiments from 0 to 1. Specific examples of such diphenol compounds include, for example, 4-hydroxy-4' -bibenzoic acid (R)₄Is COOH, R₆Is OH and q is 1); 4' -hydroxyphenyl-4-benzoic acid (R)₄Is COOH, R₆Is OH and q is 1); 3' -hydroxyphenyl-4-benzoic acid (R)₄Is COOH, R₆Is OH and q is 1); 4' -hydroxyphenyl-3-benzoic acid (R)₄Is COOH, R₆Is OH and q is 1); 4,4' -Diphenyl Carboxylic acid (R)₄Is COOH, R₆Is COOH and q is 1); (R)₄Is OH, R₆Is OH and q is1) (ii) a 3,3' -Biphenyldiphenol (R)₄Is OH, R₆Is OH and q is 1); 3,4' -Biphenyldiphenol (R)₄Is OH, R₆Is OH and q is 1); 4-Phenylphenol (R)₄Is OH and q is 0); bis (4-hydroxyphenyl) ethane (R)₄Is OH, R₆Is C₂(OH)₂Phenol and q is 1); tris (4-hydroxyphenyl) ethane (R)₄Is OH, R₆Is C (CH)₃) Bisphenol and q is 1); 4-hydroxy-4' -biphenylcarboxylic acid (R)₄Is OH, R₆Is COOH and q is 1); 4' -hydroxyphenyl-4-benzoic acid (R)₄Is OH, R₆Is COOH and q is 1); 3' -hydroxyphenyl-4-benzoic acid (R)₄Is OH, R₆Is COOH and q is 1); 4' -hydroxyphenyl-3-benzoic acid (R)₄Is OH, R₆COOH and q is 1), and the like, and combinations thereof.

In still another embodiment, in the above formula (II), B is naphthyl, so that the resulting cycloalkane compound has the following general formula (V):

wherein the content of the first and second substances,

R₄is OH or COOH;

R₆is acyl, acyloxy, acylamino, alkoxy, alkenyl, alkyl, amino, aryl, aryloxy, carboxyl ester, cycloalkyl, cycloalkoxy, hydroxyl, halo, haloalkyl, heteroaryl, heteroaryloxy, heterocyclyl or heterocycloxy; and

q is from 0 to 4, in some embodiments from 0 to 2, and in some embodiments from 0 to 1. Specific examples of such cycloalkane compounds include, for example, 1-naphthoic acid (R)₄Is COOH and q is 0); 2-naphthoic acid (R)₄Is COOH and q is 0); 2-hydroxy-6-naphthoic acid (R)₄Is COOH, R₆Is OH and q is 1); 2-hydroxy-5-naphthoic acid (R)₄Is COOH, R₆Is OH and q is 1); 3-hydroxy-2-naphthoic acid (R)₄Is COOH, R₆Is OH and q is 1); 2-hydroxy-3-naphthoic acid (R)₄Is COOH, R₆Is OH and q is 1); 2,6-Naphthalenedicarboxylic acid (R)₄Is COOH, R₆Is COOH and q is 1); 2, 3-naphthalenedicarboxylic acid (R)₄Is COOH, R₆Is COOH and q is 1); 2-hydroxy-naphthalene (R)₄Is OH and q is 0); 2-hydroxy-6-naphthoic acid (R)₄Is OH, R₆Is COOH and q is 1); 2-hydroxy-5-naphthoic acid (R)₄Is OH, R₆Is COOH and q is 1); 3-hydroxy-2-naphthoic acid (R)₄Is OH, R₆Is COOH and q is 1); 2-hydroxy-3-naphthoic acid (R)₄Is OH, R₆Is COOH and q is 1); 2, 6-dihydroxynaphthalene (R)₄Is OH, R₆Is OH and q is 1); 2, 7-dihydroxynaphthalene (R)₄Is OH, R₆Is OH and q is 1); 1, 6-dihydroxynaphthalene (R)₄Is OH, R₆OH and q is 1), and the like, and combinations thereof.

In certain embodiments of the present invention, for example, the polymer composition may comprise aromatic diols such as hydroquinone, resorcinol, 4' -biphenol, and the like, as well as combinations thereof. When used, such aromatic diols may comprise from about 0.01 wt.% to about 1 wt.%, and in some embodiments, from about 0.05 wt.% to about 0.4 wt.% of the polymer composition. Aromatic carboxylic acids may also be used in certain embodiments, either alone or in combination with the aromatic diols. The aromatic carboxylic acid may comprise from about 0.001 wt.% to about 0.5 wt.%, and in some embodiments, from about 0.005 wt.% to about 0.1 wt.% of the polymer composition. In a particular embodiment, an aromatic diol (in the above formula, R) is used in the present invention₄And R₆Is OH) (e.g. 4,4' -biphenol) with an aromatic dicarboxylic acid (in the above formula, R₄And R₆COOH) (e.g., 2, 6-naphthalene dicarboxylic acid) to help achieve the desired viscosity reduction.

Non-aromatic functional compounds other than those indicated above may also be used in the present invention. Such compounds can be used for various purposes, such as reducing melt viscosity. One such non-aromatic functional compound is water. Water may be added if desired in the form of water produced under the process conditions. For example, the water may be added as a hydrate that effectively "loses" water under process conditions (e.g., elevated temperature). Such hydrates include aluminum trihydrate, copper sulfate pentahydrate, barium chloride dihydrate, calcium sulfate dehydrate, and the like, as well as combinations thereof. When used, the hydrate may comprise from about 0.02% to about 2%, and in some embodiments, from about 0.05% to about 1%, by weight of the polymer composition. In a particular embodiment, a mixture of an aromatic diol, a hydrate, and an aromatic dicarboxylic acid is used in the composition. In such embodiments, the weight ratio of hydrate to aromatic diol is typically from about 0.5 to about 8, in some embodiments from about 0.8 to about 5, and in some embodiments, from about 1 to about 5.

E.Other additives

Other additives that may be included in the composition may include, for example, antimicrobials, pigments, antioxidants, stabilizers, surfactants, waxes, solid solvents, flame retardants, anti-drip additives, and other materials added to enhance properties and processability. Lubricants that are able to withstand the processing conditions of the liquid crystalline polymer without significant decomposition may also be used in the polymer composition. Examples of such lubricants include fatty acid esters, salts thereof, esters, fatty acid amides, organic phosphates, and hydrocarbon waxes of the type frequently used as lubricants in the processing of engineering plastic materials, 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 bis-amides, and alkanolamides such as palmitic acid amide, stearic acid amide, oleic acid amide, N' -ethylene bis-stearamide, 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 waxes, polyolefin and oxidized polyolefin waxes and microcrystalline waxes. Particularly suitable lubricants are acids, salts, or amides of stearic acid, such as 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).

III.Shaping of

The liquid crystalline polymer, mineral fibers, and other optional additives may be melt processed or blended together at a temperature in the range of about 250 ℃ to about 450 ℃, in some embodiments, in the range of about 280 ℃ to about 400 ℃, and in some embodiments, in the range of about 300 ℃ to about 380 ℃ to form the polymer composition. For example, the components (e.g., liquid crystal polymer, mineral fibers, etc.) may be provided individually or in combination to an extruder that includes at least one screw rotatably mounted and received within a barrel (e.g., a cylindrical barrel) and may define a feed section and a melt section located downstream of the feed section along the length of the screw.

The extruder may be a single screw or twin screw extruder. Referring to fig. 3, for example, one embodiment of a single screw extruder 80 is shown, comprising a housing or barrel 114 and a screw 120, which may be rotatably driven on one end by a suitable drive 124 (typically including a motor and gear box). If desired, a twin screw extruder containing two separate screws may be used. The configuration of the screw is not particularly critical to the present invention and it may contain any number and/or orientation of flights and passages as is known in the art. As shown in fig. 3, for example, the screw 120 contains flights that form a generally helical channel extending radially around the core of the screw 120. The hopper 40 is positioned adjacent to a drive 124 for supplying liquid crystal polymer and/or other materials (e.g., mineral fibers) to the feed section 132 through an opening in the barrel 114. Opposite the drive 124 is an output 144 of the extruder 80, where the extruded plastic is an output for further processing.

A feed section 132 and a melt section 134 are defined along the length of the screw 120. The feed section 132 is an input to the barrel 114 where liquid crystal polymer, mineral fibers, and/or functional compounds are added. Melt zone 134 is a phase change zone in which the liquid crystalline polymer changes from a solid to a liquid. Although these sections are not described as precisely defined when manufacturing the extruder, one of ordinary skill in the art can reliably identify the feed section 132 and the melt section 134 in which the phase change from solid to liquid occurs. Although not required, the extruder 80 can also have a mixing section 136 positioned adjacent the output end of the barrel 114 and downstream of the melting section 134. If desired, one or more distributive and/or dispersive mixing elements may be used within the mixing and/or melting section of the extruder. Suitable distributive mixers for single screw extruders may include, for example, Saxon, Dulmage, Cavity Transfer mixers, and the like. Likewise, suitable dispersive mixers may include Blister rings, Leroy/Maddock, CRD mixers, and the like. Mixing can be further improved by using pins in the barrel that fold or reorient the polymer melt, such as those used in Buss Kneader extruders, Cavity Transfer mixers, and Vortex intervening Pin mixers, as is well known in the art.

Mineral fibers may also be added to the hopper 40 or at a location downstream thereof. In one embodiment, the mineral fibers may be added at a location downstream of the point of supplying the liquid crystalline polymer. In this manner, the extent to which the length of the microfibers are reduced can be minimized, which helps maintain the desired aspect ratio. The ratio of the length ("L") to the diameter ("D") of the screws can be selected, if desired, to achieve an optimal balance between flux and retention of the aspect ratio of the mineral fibers. The L/D value may range, for example, from about 15 to about 50, in some embodiments from about 20 to about 45, and in some embodiments, from about 25 to about 40. The length of the screw may range, for example, from about 0.1 to about 5 meters, in some embodiments from about 0.4 to about 4 meters, and in some embodiments, from about 0.5 to about 2 meters. Likewise, the diameter of the screw may be from about 5 to about 150 millimeters, in some embodiments from about 10 to about 120 millimeters, and in some embodiments, from about 20 to about 80 millimeters. It is also possible to control the L/D ratio of the screw after the point of feeding the mineral fibres within a certain range. For example, the screw has a screw-in screwThe blend length ("L") defined from the point at which the fibers are supplied to the extruder to the end of the screw_B") the blend length is shorter than the total length of the screw. L of the screw after the point of feeding the mineral fibres_BThe ratio/D, for example, may be in the range of from about 4 to about 20, in some embodiments from about 5 to about 15, and in some embodiments, from about 6 to about 10.

In addition to length and diameter, other aspects of the extruder may be controlled. For example, the speed of the screw may be selected to achieve a desired residence time, shear rate, melt processing temperature, and the like. For example, the screw rate may range 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 may also be about 100 seconds during melt blending^-1To about 10,000 seconds^-1In some embodiments, about 500 seconds^-1To about 5000 seconds^-1And in some embodiments about 800 seconds^-1To about 1200 seconds^-1In the middle range. The apparent shear rate is equal to 4Q/pi R³Wherein Q is the volumetric flow rate of the polymer melt ('m')³S ") 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 of shaping, the present inventors have discovered that the resulting polymer composition 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 one embodiment, at 1000 seconds^-1The polymer composition may have a melt viscosity of from about 0.1 Pa-s to about 150 Pa-s, in some embodiments from about 0.5 Pa-s to about 120 Pa-s, and in some embodiments, from about 1 Pa-s to about 100 Pa-s, as measured at a shear rate of (a). The melt viscosity can be determined according to ISO test No. 11443 at a temperature 15 ℃ above the melting temperature of the composition (e.g., 350 ℃). The composition may also have a relatively high melting temperature. For example, the melting temperature of the polymer may be from about 250 ℃ to about 400 ℃, in some embodiments about 2From 80 ℃ to about 395 ℃, and in some embodiments from about 300 ℃ to about 380 ℃.

IV.Compact camera module

Once formed, the polymer composition can be molded into shaped parts for compact camera modules. For example, the shaped part may be molded using a one-component injection molding process, wherein dried and preheated plastic pellets are injected into a mold. Regardless of the technique used, it has been found that the molded parts of the present invention can have a relatively smooth surface, as can be indicated by their surface gloss. For example, the surface gloss may be about 35% or greater, in some embodiments about 38% or greater, and in some embodiments, from about 40% to about 60%, as measured using a gloss meter at an angle of about 80 ° to about 85 °. It is generally believed that parts having such smooth surfaces will not also have sufficiently good mechanical properties. Contrary to conventional thinking, however, it has been found that the molded parts of the present invention have excellent mechanical properties. For example, the components may have a high weld strength, which is useful when forming thin components of a compact camera module. For example, the part may exhibit a weld strength of from about 10 kilopascals ("kPa") to about 100kPa, in some embodiments from about 20kPa to about 80kPa, and in some embodiments, from about 40kPa to about 70kPa, which is the peak stress determined according to ISO test number 527 (technically equivalent to ASTM D638) at 23 ℃.

The part may also have a thickness of greater than about 3kJ/m as measured at 23 ℃ according to ISO test number 179-1 (technically equivalent to ASTM D256, method B)²Greater than about 4kJ/m²In some embodiments from about 5 to about 40kJ/m²And in some embodiments from about 6 to about 30kJ/m²The impact strength of the gap of the simply supported beam. The tensile and flexural mechanical properties of the parts are also good. For example, the component may have 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 100 to about 350 MPa; a tensile strain at break of about 0.5% or greater, in some embodiments from about 0.6% to about 10%, and in some embodiments, from about 0.8% to about 3.5%; and/or about 5,00A tensile modulus of from 0MPa to about 20,000MPa, in some embodiments from about 8,000MPa to about 20,000MPa, and in some embodiments, from about 10,000MPa to about 15,000 MPa. Tensile properties can be determined according to ISO test No. 527 (technically equivalent to ASTM D638) at 23 ℃. The component may also have 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 100 to about 350 MPa; a flexural strain at break of about 0.5% or greater, in some embodiments from about 0.6% to about 10%, and in some embodiments, from about 0.8% to about 3.5%; and/or a flexural modulus of from about 5,000MPa to about 20,000MPa, in some embodiments from about 8,000MPa to about 20,000MPa, and in some embodiments, from about 10,000MPa to about 15,000 MPa. Tensile properties can be determined according to ISO test number 178 (technically equivalent to ASTM D790) at 23 ℃. The molded part can also have a load Deflection Temperature (DTUL) of about 200 ℃ or more, and in some embodiments, about 200 ℃ to about 280 ℃, measured at a rated load of 1.8MPa according to ASTM D648-07 (technically equivalent to ISO test No. 75-2).

Furthermore, the molded parts may also have excellent antistatic behavior, especially when conductive fillers are included in the polymer composition. Such antistatic behavior may be characterized by a relatively low surface and/or volume resistivity, determined according to IEC 60093. For example, the molded part may exhibit about 1 × 10¹⁵Ohm or less, and in some embodiments, about 1X 10¹⁴Ohm or less, and in some embodiments, about 1X 10¹⁰Ohm to about 9 x 10¹³Ohmic, and in some embodiments, about 1 x 10¹¹To about 1X 10¹³Ohmic surface resistivity. Likewise, the molded part may also exhibit about 1 × 10¹⁵Ohm-meters or less, and in some embodiments, about 1X 10¹⁰Ohm-meter to about 9 x 10¹⁴Ohm-meter, and in some embodiments, about 1 x 10¹¹To about 5X 10¹⁴Ohm-meter volume resistivity. Of course, such antistatic behavior is by no means required. For example, in some embodiments, the molded part may exhibit a relatively high sheet resistanceE.g. about 1X 10¹⁵Ohmic or greater, and in some embodiments about 1X 10¹⁶Ohmic or greater, and in some embodiments about 1X 10¹⁷Ohm to about 9 x 10³⁰Ohmic, and in some embodiments about 1 × 10¹⁸To about 1X 10²⁶Ohm.

The polymer compositions and molded parts of the present invention can be used in a wide variety of compact camera module configurations. A particularly suitable compact camera module is shown in fig. 1-2. As shown, the compact camera module 500 contains a lens assembly 504 that is superimposed on a base 506. The base 506 in turn overlies an optional main plate 508. Due to its relatively thin nature, the base 506 and/or the motherboard 508 are particularly suitable for molding from the polymer composition of the present invention as described above. The lens assembly 504 can have any of a variety of configurations known in the art. In one embodiment, for example, the optic assembly 504 is in the form of a hollow cylinder that houses a lens 604, the lens 604 being in communication with an image sensor 602 disposed on the motherboard 508 and controlled by the circuitry 601. The barrel may have any of a variety of shapes, such as rectangular, cylindrical, etc. In certain embodiments, the barrel may also be formed from the polymer composition of the present invention and have a wall thickness within the ranges described above. It should be understood that other components of the camera module may also be formed from the polymer composition of the present invention. For example, as shown, a polymeric film 510 (e.g., polyester film) and/or an insulative cover 502 can cover the lens assembly 504. In some embodiments, the film 510 and/or the cover 502 can also be formed from the polymer composition.

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

Test method

Melt viscosity: can be tested according to ISO test number 11443 at 1000s^-1(iii) and melting temperature (e.g., 350 ℃) the melt viscosity (Pa · s) was determined using a Dynisco LCR7001 capillary rheometer at a temperature above 15 ℃. The rheometer orifice (die) had a diameter of 1mm, a length of 20mm, an L/D ratio of 20.1, and an entrance angle of 180 °. Of cylindersA diameter of 9.55mm +0.005mm and a rod length of 233.4 mm.

Melting temperature: the melting temperature ("Tm") is determined by differential scanning calorimetry ("DSC") as known in the art. The melting temperature is the Differential Scanning Calorimetry (DSC) peak melt temperature as determined by ISO test No. 11357. Under the DSC program, the sample was heated and cooled at 20 ℃/min using DSC measurements performed on a TA Q2000 instrument as described in ISO standard 10350.

Load deformation temperature ("DTUL"): the load deflection temperature was determined according to determination ISO test No. 75-2 (technically equivalent to ASTM D648-07). More specifically, test strip samples 80mm in length, 10mm in thickness and 4mm in width were subjected to a three-point bending test along the edge with a nominal load (maximum external fiber stress) of 1.8 mpa. The sample was placed in a silicone oil bath where the temperature was increased at 2 deg.C/min until it deformed 0.25mm (0.32 mm for ISO test number 75-2).

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

Flexural modulus, flexural stress and flexural strain: flexural properties were tested according to ISO test No. 178 (technically equivalent to ASTM D790). The test was performed on a 64mm support span. The test was performed on the center portion of an uncut ISO 3167 multipurpose stick. The test temperature was 23 ℃ and the test speed was 2 mm/min.

Impact strength of the notched simply supported beam: notched simple beam properties were tested according to ISO test number ISO 179-1 (technically equivalent to ASTM D256, method B). The test was conducted using a type a notch (0.25mm base radius) and type 1 specimen dimensions (length 80mm, width 10mm, and thickness 4 mm). Samples were cut from the center of the multi-purpose bar using a single tooth grinder. The test temperature was 23 ℃.

Seam Strength seam strength can be determined as is well known in the art by first forming an injection molded wire mesh grid array ("LGA") connector (dimensions: 49 mm. times.39 mm. times.1 mm) from a sample of the polymer composition. Once formed, the LGA connector may be placed on a sample holder. The center of the connector can be subjected to tension by moving the rod at a speed of 5.08 mm/min. The peak stress can be recorded as an estimate of the joint strength.

Surface gloss: a gloss meter may be used to measure the gloss of a surface. Gloss readings may be taken at two different locations on the surface at an incident light angle of 85 ° relative to the surface of the part, with three replicate measurements taken at each location. The average of the readings can be used to calculate the gloss. Any suitable Gloss meter may be used to measure Gloss, such as Micro-TRI-Gloss from BYK Gardner GmbH.

Example 1

Samples 1-5 were made from various percentages of liquid crystalline polymer, wollastonite (E)4W or 8), anhydrous calcium sulfate, lubricant (Glycolube)^TMP), conductive filler and black masterbatch, as shown in table 1 below. The black masterbatch comprises 80 wt% liquid crystalline polymer and 20 wt% carbon black. In samples 1-5, the conductive filler includes carbon fibers. In sample 6, the conductive filler further includes graphite. Finally in sample 7, the conductive filler was an ionic liquid, i.e., tri-n-butyl methylammonium bis (trifluoromethanesulfonyl) -imide (FC-4400 from 3M). The liquid crystalline polymer in each sample was formed from HBA, HNA, TA, BP and APAP as described in U.S. patent No. 5,508,374 to Lee et al. A comparative sample (comparative sample 1) was also formed without wollastonite. Compounding was carried out using an 18-mm single screw extruder. Parts were injection molded from the samples into plaques (60 mm. times.60 mm).

TABLE 1

Some molded parts were also tested for thermal and mechanical properties. The results are shown in table 2 below.

TABLE 2

	Sample No. 6	Sample 7
			1000s-1And a melt viscosity (Pa. s) at 350 DEG C	48.6	51.6
400s-1And a melt viscosity (Pa. s) at 350 DEG C	78.5	78.6
			Tm(℃)	330.4	329.7
DTUL at 1.8MPa (. degree.C.)	212.4	215.7
			Tensile stress at break (MPa)	117.63	81.8
Tensile modulus (MPa)	9,249	8,842
			Tensile strain at break (%)	2.5	1.5
Flexural stress at Break (MPa)	114	105
			Flexural modulus (MPa)	8,518	9,344
Flexural strain at break (%)	2.6	1.9
			Simply supported beam gap (KJ/m)2)	6.1	1.7

Example 2

Samples 8-9 were made from various percentages of liquid crystalline polymer, wollastonite (E)4W), lubricant (Glycolube)^TMP), mica, hydrated alumina ("ATH"), 4' -biphenol ("BP"), and 2, 6-naphthalenedicarboxylic acid ("NDA") as shown in table 3 below. The liquid crystal polymer in each sample was formed from 4-hydroxybenzoic acid ("HBA"), 2, 6-hydroxynaphthoic acid ("HNA"), terephthalic acid ("TA"), and hydroquinone ("HQ"), as described in U.S. patent No. 5,969,083 to Long et al. NDA is used in the polymer in an amount of 20 mol%. Comparative samples (comparative samples 2 and 3) were also formed without wollastonite. Compounding was carried out using an 18-mm single screw extruder. Will be provided withParts were injection molded from the samples into plaques (60 mm. times.60 mm).

TABLE 3

Some molded parts were also tested for thermal and mechanical properties. The results are shown in table 4 below.

TABLE 4

Example 3

Sample 10 was prepared from liquid crystalline polymer, wollastonite: (4W), lubricant (Glycolube)^TMP), talc, alumina hydrate ("ATH"), 4' -biphenol ("BP"), 2, 6-naphthalene dicarboxylic acid ("NDA"), and black masterbatch, as shown in table 5 below. The liquid crystalline polymer in each sample was formed from 4-hydroxybenzoic acid ("HBA"), 2, 6-hydroxynaphthoic acid ("HNA"), terephthalic acid, and 4,4' -biphenol ("BP"). HNA was used in the polymer in an amount of 20 mol%. Compounding was carried out using an 18-mm single screw extruder. Parts were injection molded from the samples into plaques (60 mm. times.60 mm).

TABLE 5

The molded parts were also tested for thermal and mechanical properties. The results are shown in table 6 below.

TABLE 6

	Sample 8
		1000s-1And a melt viscosity (Pa. s) at 350 DEG C	20.0
400s-1And a melt viscosity (Pa. s) at 350 DEG C	34.3
		Tm(℃)	343.79
[email protected](℃)	274
		Simply supported beam gap (KJ/m)2)	2
Tensile stress at break (MPa)	11
		Tensile modulus (MPa)	97
Tensile strain at break (%)	8,254
		Flexural stress at Break (MPa)	2.02
Flexural modulus (MPa)	127
		Flexural strain at break (%)	9,005
Joint strength (lbf)	2.35

Example 4

Samples 11-12 were made from various percentages of liquid crystalline polymer, wollastonite (E)8) Talc and black pigment (HCN-LC DU 005) as shown in table 7 below. The liquid crystalline polymer in each sample was formed from 4-hydroxybenzoic acid ("HBA"), terephthalic acid ("TA"), 4' -biphenol ("BP"), 2, 6-naphthalenedicarboxylic acid ("NDA"), and hydroquinone ("HQ"), as taught inLong et alAs described in U.S. patent No. 5,969,083. NDA is used in the polymer in an amount of 20 mol%. Compounding was performed using an 18-mm single screw extruder, where wollastonite fiber was added to No. 6 barrel. Parts were injection molded from the samples into plaques (60 mm. times.60 mm).

TABLE 7

Some molded parts were also tested for thermal and mechanical properties. The results are set forth in Table 8 below.

TABLE 8

	Sample 11	Sample 12
			1000s-1And a melt viscosity (Pa. s) at 350 DEG C	46.6	37.2
400s-1And a melt viscosity (Pa. s) at 350 DEG C	74.4	58.5
			Tm(℃)	330.6	331.6
[email protected](℃)	271	-
			Simply supported beam gap (KJ/m)2)	2.9	3.1
Tensile stress at break (MPa)	85	114
			Tensile modulus (MPa)	15,042	14,389
Tensile strain at break (%)	0.8	1.4
			Flexural stress at Break (MPa)	130	141
Flexural modulus (MPa)	15,903	15,343
			Flexural strain at break (%)	1.3	1.7

These and other modifications and variations to the present invention may be practiced by those of ordinary skill in the art, without departing from the spirit and scope of the present invention. Additionally, it should be understood that aspects of the various embodiments may be interchanged both in whole or in part. Furthermore, those of ordinary skill in the art will appreciate that the foregoing description is by way of example only, and is not intended to limit the invention so further described in such appended claims.