TWI580713B - Polymer composition for producing articles with light reflective properties - Google Patents

Description

Polymer composition for preparing articles having light reflecting properties

There are many different types of applications that require plastic objects to have good light reflective properties. For example, the objects can be used as reflectors for light sources. The reflector can be designed to reflect light in one direction or in all directions. Highly reflective objects are also suitable for the manufacture of signs. Reflective materials can be used to emphasize the words, phrases or symbols presented on the logo. For example, in one embodiment, the indicia can include a light source surrounded by a highly reflective material.

Highly reflective polymeric materials are also well suited for marking to emphasize the design of the printed matter on the mark or on the mark.

In applications where the reflective properties may improve the aesthetic appeal of the product, molded polymeric articles having high reflective properties may also be desirable. For example, decorative sheets with high reflective properties may be very suitable for consumer equipment products, decorative sheets and instrument front covers for automobiles, and decorative sheets for various other consumer products.

Molded polymer articles having good reflective properties can also be used as reflectors for light emitting diodes. Light-emitting diodes are often referred to as LEDs, and their popularity as a light source for many different applications is increasing. For example, LEDs are replacing incandescent sources and other light sources in many applications and have been used, for example, as traffic signals, large area displays, interior and exterior lighting, cellular telephone displays, digital clock displays, consumer device displays, flashlights and the like. analog.

The LED reflector can also function as an LED housing and is typically fabricated from a molded polymeric resin. For example, the polymeric resin can be injection molded to form an outer shell and Projector. In one embodiment, the polymeric resin is injection molded onto the leadframe for integration of the leadframe into the LED assembly. In some embodiments, the LED device located within the reflector can be sealed by a translucent or transparent resin. A transparent or translucent resin can act as a lens to further enhance the emitted light.

In U.S. Patent Publication No. 2007/0213458, entitled "Light-Emitting Diode Assembly Housing Comprising Poly (cyclohexanedimethanol terephthalate) Compositions", a poly(cyclohexanedimethanol terephthalate) is disclosed (hereinafter Reflectors for LEDs made by the "PCT" composition, which is incorporated herein by reference.

The present invention is generally directed to further improvements in polymer compositions having a desired combination of properties, such as reflectivity and strength, when molded into a variety of different articles.

The present invention generally relates to a polymer composition and molded articles made from the composition. The polymer composition typically comprises a thermoplastic polymer in combination with one or more components. The different components may include pigments (such as white pigments), reactive modifiers, reinforcing agents (such as glass fibers), optical brighteners, impact modifiers, lubricants, heat stabilizers, oxidative stabilizers, and / or UV stabilizer. As will be described in more detail below, the various components can be blended with the thermoplastic polymer in a manner to produce a molded article having the desired characteristics. In one embodiment, for example, the composition can be formulated such that the resulting molded article can have excellent reflectivity properties. In other embodiments, the composition can be formulated to have good melt flow properties and/or good mechanical properties. In one embodiment, the composition can also be formulated to It is very suitable for combination with polyoxyl polymers.

As noted above, in one embodiment, the polymer composition can have excellent reflectivity properties. For example, the polymer composition can have an initial reflectance greater than about 90% at 460 nm, such as greater than about 93%, such as greater than about 95%. The initial reflectance at 460 nm is typically less than 100%. The polymeric material can also have an initial whiteness index above about 84, such as above about 92, such as above about 95. For a particular advantage, the polymeric material can have greater than about 50, such as greater than about 60, such as greater than about 62, such as greater than about 65, such as greater than about 68, such as even after aging for 4 hours at 200 °C. A whiteness index above about 70. In general, the whiteness index after aging at 200 ° C is lower than the initial whiteness index of the material, and is generally less than about 95.

The polymer composition may also have a whiteness index retention of greater than about 60%, such as greater than about 65%, such as greater than about 70%, such as even greater than about 75%, after aging for 4 hours at 200 °C.

In other embodiments, the polymer composition can be formulated to have excellent mechanical properties. For example, in one embodiment, the polymer composition can have a notched Charpy impact strength of greater than about 2 kJ/m ² , such as greater than about 2.5 kJ/m ² . The polymer composition can also be formulated to have good polyoxymethylene bond strength. For example, the polymer composition can have a polyoxymethylene bond strength of greater than about 25 pounds force, depending on the lap-shear test.

Generally, the polymer composition contains a thermoplastic polymer, such as a thermoplastic polymer having a melting point above about 260 °C. The thermoplastic polymer may comprise a polyester polymer (including a liquid crystal polymer), a fluorocarbon polymer, a polyamine polymer, and the like. In one embodiment, the thermoplastic polymer comprises Poly(1,4-cyclohexanedimethanol terephthalate).

In addition to the thermoplastic polymer, the polymer composition may optionally contain various other components. In one embodiment, for example, the polymer composition can contain a pigment, such as a white pigment. White pigments can be present in amounts greater than about 10% by weight, especially in applications where reflectivity properties are important.

Another optional component that may be present in the composition is an enhancer. The reinforcing agent may comprise a fiber or an inorganic filler. In one embodiment, for example, the composition contains glass fibers in an amount from about 10% to about 30% by weight.

Another optional component that may be present in the polymer composition is a reactive modifier. The reactive modifier reacts with the thermoplastic polymer in a manner that provides one or more benefits. For example, a reactive modifier can act as a chain extender that can stabilize the polymer during the melt processing or can improve the light stabilizing characteristics of the polymer.

The polymer composition may also optionally contain one or more impact modifiers. The impact modifier can be reactive or non-reactive with the thermoplastic polymer. For example, in one embodiment, the polymeric material comprises a terpolymer of ethylene, methyl acrylate, and glycidyl (meth)acrylate. In another embodiment, the polymeric material comprises an ethylene-(meth)acrylate copolymer. In another embodiment, the polymeric material can include a combination of a terpolymer of ethylene, methyl acrylate, and glycidyl (meth)acrylate with an ethylene-(meth) acrylate copolymer.

In another embodiment, the polymer composition can contain a stabilizer. In a particular embodiment, the stabilizer may comprise an organophosphorus compound, such as a phosphonate stabilizer or a phosphate stabilizer.

Other features and aspects of the present invention are discussed in greater detail below.

The complete and practical disclosure of the present invention, including the best mode for those skilled in the art, is set forth in more detail in the remainder of the specification, including reference to the drawings.

The description of the present invention is intended to be illustrative only, and is not intended to limit the invention.

In general, the present invention relates to a polymer composition and articles made from the composition, which articles can exhibit reflectivity, whiteness, flow properties during melt processing, and/or mechanical properties such as impact strength. Various properties. The compositions of the invention are useful in many different end use applications. For example, the composition can be used as a light reflector. For example, the polymer composition can be used to fabricate reflectors for LED components, can be used as a component in a logo, such as a light sign, can be used as a marker, or for any other that may require excellent reflectivity properties. Suitable for the application.

In addition to the above, the polymer composition can be used to mold a variety of other polymeric articles. The polymeric articles may include components for consumer products, such as consumer devices, automotive components (including decorative sheets and instrument front covers for automotive interiors or for automotive exteriors), and the like. While the polymer compositions of the present invention have excellent reflective properties, the polymer compositions can be selected for use in a variety of applications where reflective properties are not desired. In such applications, the polymer composition can be selected due to the melt flow properties, strength properties, impact properties, or the like of the polymer composition.

The polymer composition of the present invention may contain different amounts of different components and components To make formulations that are well suited for a particular end use application. In general, the polymer composition contains a thermoplastic polymer in combination with various optional components. One or more of the optional components can be combined in a manner that optimizes certain desirable properties. For example, where a reflectivity property is desired, one or more pigments can be combined with the polymer composition. However, if the reflectance properties are not critical in a particular application, the one or more pigments can be removed from the formulation and/or used in minor amounts.

In general, the polymer composition contains at least one thermoplastic polymer, and especially at least one high temperature thermoplastic polymer. For example, the thermoplastic polymer can have a melting temperature above about 260 °C, such as above about 270 °C, such as above about 280 °C, such as above about 290 °C. In one embodiment, the thermoplastic polymer can have a melting temperature below about 500 °C, such as below about 400 °C, such as below about 350 °C.

In one embodiment, the thermoplastic polymer comprises a polyester polymer, such as a poly(1,4-cyclohexanedimethanol terephthalate) polymer; a liquid crystal polymer; a polyamide polymer; a fluorocarbon Polymer or a mixture thereof.

The polymer composition may optionally contain a pigment, such as a white pigment. The composition may also optionally contain reinforcing agents such as fillers or reinforcing fibers. According to the invention, the composition may further comprise one or more reactive modifiers. The one or more reactive modifiers can comprise a polymer that reacts with the thermoplastic polymer to provide one or more benefits. For specific advantages, a reactive modifier that does not cause unwanted yellowing of the composition during subsequent use, particularly when the composition is used as a light source reflector, can be selected. In this regard, the composition may also be formulated to exclude the addition that may cause yellowing. Agents and stabilizers. In this regard, in one embodiment, the composition is free of some or all of any aromatic epoxy resin, and is especially free of phenolic epoxy resins.

The polymer compositions of the present invention can be formulated to have excellent melt flow properties. With regard to melt flow properties, for example, in one embodiment, the polymer composition can have a spiral flow length of at least 5 Torr, such as at least 6 Torr, such as even at least 7 Torr. In general, the spiral flow length is less than about 15 inches, such as less than about 12 inches. As used herein, the spiral flow length was measured at a temperature of 305 ° C and at a mold temperature of 120 ° C. The spiral flow length was measured by injecting the polymer composition into a mold (one half of the mold shown) as shown in FIG. The mold cavity is 1/32 inch thick (height) and 1/2 inch wide. The polymer composition was injected into the mold using a 32 mm extruder at an injection speed of 4 Å/sec and an injection size of 1.8 Å. The spiral flow length generally indicates the flow characteristics of the polymer composition as it is melt processed. The higher spiral flow length indicates the ability of the material to flow evenly and evenly into the mold, which also indicates the ability of the material to fill any mold voids that may be present. For example, a higher spiral flow length is especially preferred when molding a small component that can have a complex three-dimensional configuration, such as a reflector and housing of an LED assembly.

In addition to having a relatively high spiral flow length, the polymer compositions made in accordance with the present invention can also be formulated to have a stable viscosity. In particular, the melt viscosity of the composition during processing can fluctuate by no more than about 5%, such as no more than about 3%.

The polymer compositions of the present invention also have relatively high initial reflectance and excellent reflectivity stability. For example, once molded into an article, the invention The polymer composition can have an initial reflectance of greater than about 90% at 460 nm, such as greater than about 93%, such as greater than about 95%. The reflectance was measured using spectroscopic color measurement according to ASTM test method 1331. The CIE D65 daylight illuminator was used at an angle of 10° during the test.

In addition to the initial reflectance, polymeric articles made in accordance with the present invention may also have a relatively high initial whiteness index. The whiteness index can be measured according to WI E313. Articles made in accordance with the present invention may have an initial whiteness index above about 80, such as above about 90, such as above about 92, such as above about 95.

Objects made in accordance with the present invention also have greater reflectivity stability with respect to particular advantages. For example, an article made in accordance with the present invention may have a whiteness index of at least about 50, such as at least about 60, such as at least about 70, such as at least about 72, such as at least about 74, such as at least about 74 after aging for 4 hours at 200 °C. Even higher than about 75. The whiteness index after aging is lower than the initial whiteness index.

The reflectance stability properties of articles made in accordance with the present invention can also be measured by their percent whiteness index retention after aging for 4 hours at 200 °C. In particular, articles made in accordance with the present invention may have a whiteness index retention percentage of greater than about 60%, such as greater than about 65%, such as greater than about 70%, such as even greater than about 75%, after heat aging. The percentage of retention is generally less than about 95%.

In one embodiment, the polymer composition can be formulated such that the polymeric article made from the composition absorbs light in the ultraviolet and violet regions of the electromagnetic spectrum, which can be about 300 nanometers ("nm"). To about 400 nm, and again emitting light in the blue region, the light can be from about 410 nm to about 470 nm. The polymer article of the present invention is significant due to re-emitting light in the blue region Enhanced brightness, especially when used as a reflector for light sources.

In addition to the above properties, the polymer compositions of the present invention also have good resistance to reflow properties at relatively high temperatures, such as temperatures of about 260 °C. The polymeric material has good polyoxymethylene adhesion properties which may be important in applications where an adhesive is used to attach the fitting in the LED assembly to the reflector or to connect the reflector to the substrate. Articles made in accordance with the present invention also have good mechanical properties, such as good impact resistance. The materials of the present invention may also exhibit low moisture absorption.

As noted above, the polymer compositions of the present invention are useful in a variety of applications. When the polymer composition is formulated to have good reflective properties, for example, the polymer composition can be used to make a reflector for a light source. In a particular embodiment, for example, the polymer composition can be used to fabricate a reflector for an LED assembly.

Referring to Figures 1 and 2, one embodiment of an LED assembly 10 that can be fabricated in accordance with the present invention is shown. In the embodiment illustrated in Figures 1 and 2, LED assembly 10 is considered a side view of the LED. As shown, LED assembly 10 includes a light emitting diode 12 that is configured to emit light as current is fed through the element. For example, the light emitting diode 12 can comprise a semiconductor wafer that includes multiple layers of material. LED 12 typically includes an n-type material layer and a p-type material layer, thereby forming a p-n junction that can be connected to a voltage source. In one embodiment, for example, the p-type layer can comprise doped aluminum gallium arsenide and the n-type layer can comprise doped gallium arsenide.

The LED 12 is connected to the first wiring 14 and the second wiring 16. Wirings 14 and 16 are connected to leadframe 18. The lead frame 18 includes a first lead frame portion 20 and a second lead Wireframe portion 22. Leadframe 18 can include or be coupled to anode 24 and cathode 26, which can also be considered as first terminal 24 and second terminal 26.

In accordance with the present invention, LED assembly 10 further includes a reflector 28 that can also serve as a housing for the LED assembly. In accordance with the present invention, reflector 28 is made from a polymer composition having excellent reflectivity properties.

As shown in Figures 1 and 2, the reflector 28 defines a pocket 30 in which the LED 12 is located. The wall of the pocket 30 generally surrounds the LED 12 and, in the illustrated embodiment, has a depth sufficient to recess the LED 12 into the recess.

The recess 30 of the reflector 28 surrounds the LED 12 and serves to reflect the light emitted by the LED in an outward direction. The pocket 30 can have any suitable shape. For example, the pocket 30 can be cylindrical, tapered, parabolic, or any other suitable curved form. Alternatively, the walls of the pockets 30 may be parallel, substantially parallel or wedge shaped relative to the diodes 12. In the embodiment illustrated in FIG. 1, for example, the pocket 30 has a smooth surface and includes side walls 32 and 34 and end walls 36 and 38. The side walls 32 and 34 are wedge-shaped with respect to the LED 12 in the outward direction. Alternatively, end walls 36 and 38 may be substantially parallel to the LED source or may be wedge-shaped outwardly.

If desired, the pockets 30 of the reflector 28 can be filled with a transparent material such as a transparent material or a translucent material. For example, the pockets 30 can be filled with an epoxy material or a polyoxynitride material. In one embodiment, the material used to fill the pockets 30 can act as a lens for the light emitted by the LEDs 12.

Referring to Figure 3, another embodiment of an LED assembly 50 that can be fabricated in accordance with the present invention is shown. In the embodiment illustrated in Figure 3, a top view of the LED assembly is shown. The top view of the LED assembly 50 is similar in construction to the side view of the LED assembly 10 illustrated in Figures 1 and 2.

For example, the top view of LED assembly 50 includes LEDs 52 at the bottom of pockets 54 of reflector 56. LED 52 is also connected to leadframe 58. In the embodiment illustrated in FIG. 3, the pockets 54 of the reflector 56 are filled with a transparent material 60.

The LED components shown in Figures 1 through 3 generally have a relatively small size. For example, LED components typically have a maximum dimension, such as height, width, depth, or diameter, that is generally less than about 10 mm, such as typically less than about 8 mm. The LED assembly typically includes at least one dimension that is less than 5 mm, such as less than 2 mm, such as even less than 1 mm, such as depth. As will be described below, the polymer composition of the present invention is capable of forming a reflector for an LED assembly using a melt flow processing technique. For example, in one embodiment, the polymer composition of the present invention is blow molded while forming a reflector. For a particular advantage, the compositions of the present invention are formulated to have melt flow properties capable of simultaneously forming hundreds of reflectors.

As stated above, the polymer composition of the present invention contains a high temperature thermoplastic polymer. For example, the thermoplastic polymer can have a melting point of at least 260 °C. A variety of different thermoplastic polymers, including mixtures of thermoplastic polymers, can be used in accordance with the present invention. In a particular embodiment, the thermoplastic polymer comprises a poly(1,4-cyclohexanedimethanol terephthalate) polymer, commonly referred to as a "PCT" polymer. Poly(1,4-cyclohexanedimethanol terephthalate) is a polyester containing repeating units derived from a dicarboxylic acid component and a glycol component. At least about 80 mole%, more preferably at least about 90 mole%, and particularly preferably all of the diol repeat units are derived from 1,4-cyclohexanedimethanol and have formula (I).

At least about 80 mole percent, more preferably at least about 90 mole percent, and particularly preferably all of the dicarboxylic acid repeat units are derived from terephthalic acid and have formula (II).

In one embodiment, the PCT polymer contains 100 mole percent terephthalic acid or diester. In another aspect, the glycol component can contain a total of 100 mole % 1,4-cyclohexanedimethanol.

However, in various embodiments, the dicarboxylic acid component may contain up to 10 mole % of other aromatic, aliphatic or alicyclic dicarboxylic acids such as isophthalic acid, naphthalene dicarboxylic acid, cyclohexane dicarboxylic acid, Succinic acid, suberic acid, adipic acid, glutaric acid, sebacic acid and the like.

The glycol component may also contain up to about 10 mole % of other aliphatic or cycloaliphatic diols such as diethylene glycol, triethylene glycol, ethylene glycol, propylene glycol, butylene glycol, pentanediol, Glycols and their analogs.

The PCT polymer can have an intrinsic viscosity (I.V.) of from about 0.3 to about 1.5 and a melting point of at least 260 °C.

In one embodiment, the PCT polymer can comprise a blend of two or more different grades of PCT polymers. For example, in one embodiment, a blend of a high I.V. PCT polymer with a low I.V. PCT polymer, such as a 1:1 blend, can be used. In an alternative embodiment, two The carboxylic acid component is a blend of a PCT polymer of 100 mole % terephthalic acid and a PCT polymer having a dicarboxylic acid component of 90 mole % terephthalic acid and 10 mole % isophthalic acid, Such as a 2:1 blend.

In general, the PCT polymer is present in an amount of at least about 20% by weight, such as in an amount of at least 30% by weight, such as in an amount of at least 40% by weight, such as in an amount of at least about 50% by weight, such as at least about 60% The amount by weight is present in the composition. The PCT polymer is typically present in an amount less than about 80% by weight, such as in an amount less than about 70% by weight. In one embodiment, the PCT polymer is present in an amount from about 20% to about 60% by weight.

In addition to the PCT polymer, the thermoplastic polymer can comprise a variety of other polymers. In general, any suitable thermoplastic polymer can be used in accordance with the present invention. For example, the melting point of the polymer can be above about 260 °C, such as above about 270 °C, such as above about 280 °C, such as even above about 290 °C. The thermoplastic polymer may generally have a melting point below about 500 ° C, such as below about 400 ° C, such as below about 350 ° C.

Thermoplastic polymers that can be used in accordance with the present invention in addition to PCT polymers include polyetheretherketone polymers; other polyester polymers such as polybutylene terephthalate and polyethylene terephthalate. For example, in one embodiment, a polybutylene terephthalate polymer having high crystallinity and/or a polyethylene terephthalate polymer is used. Other useful thermoplastic polymers include polytrimethylene terephthalate and liquid crystal polymers such as liquid crystal polyester polymers. Still other useful thermoplastic polymers include high temperature polyamine polymers. Such polymers may include, for example, nylon 66, nylon 3, nylon 4, nylon 5, nylon 46, and the like. Polytetrafluoroethylene polymer and fluorinated B Ene polymers are also very suitable for use in the present invention. Other useful thermoplastic polymers include ethylene-carbon monoxide polymers, styrene acrylonitrile polymers, and styrene maleic anhydride polymers.

In addition to the thermoplastic polymer, the composition may also contain one or more of a variety of other components. For example, when the reflective properties are more important, the composition may contain at least one pigment, such as a white pigment. The at least one white pigment may be present in an amount greater than about 10% by weight, such as in an amount of at least about 15% by weight, when present to improve reflective properties. The white pigment is present in the composition in an amount sufficient to increase the reflectivity of the article molded from the composition. White pigments which may be included in the composition include titanium dioxide, zinc oxide, white lead, aluminum oxide, barium sulfate and the like.

In one embodiment, the white pigment comprises titanium dioxide. Titanium dioxide can be of any kind, such as rutile titanium dioxide. The titanium dioxide particles can have any suitable shape, such as spherical particles or elliptical particles. The titanium dioxide powder may comprise particles having a diameter of from about 10 nm to about 20,000 nm, such as from about 150 nm to about 500 nm.

In one embodiment, the titanium dioxide particles can be coated. For example, the titanium dioxide particles may first be coated with an inorganic coating and then optionally coated with an organic coating that is applied to the inorganic coating. Useful inorganic coatings include metal oxides. Organic coatings can include carboxylic acids, polyols, alkanolamines and/or hydrazine compounds.

Examples of carboxylic acids suitable for use in organic coatings include adipic acid, terephthalic acid, lauric acid, myristic acid, palmitic acid, stearic acid, polyhydroxystearic acid, oleic acid, salicylic acid, malic acid, and cis. Butylene diacid. As used in this article The term "carboxylic acid" includes esters and salts of carboxylic acids.

Examples of hydrazine compounds suitable for use in organic coatings include, but are not limited to, decanoates, organodecanes and organooxyalkylenes (including organoalkoxy decanes), amino decanes, epoxy decanes, decyl decanes, and polyhydroxy hydrazines. Oxytomane. Suitable decanes may have the formula R _x Si(R') _4-x , wherein R is a non-hydrolyzable aliphatic, cycloaliphatic or aromatic group having from 1 to about 20 carbon atoms, and R' is one or more Hydrolyzable groups such as alkoxy, halogen, ethoxylated or hydroxy, and x is 1, 2 or 3.

Suitable decanes for organic coatings include one or more of the following: hexyltrimethoxydecane, octyltriethoxydecane, decyltriethoxydecane,decyltriethoxydecane,dodecyltriethyl Oxydecane, tridecyltriethoxydecane, tetradecyltriethoxydecane, heptadecyltriethoxydecane,hexadecyltriethoxydecane,heptadecyltriethoxydecane, ten Octa-triethoxydecane, N-(2-aminoethyl) 3-aminopropylmethyldimethoxydecane, N-(2-aminoethyl) 3-aminopropyltrimethoxy Baseline, 3-aminopropyltriethoxydecane, 3-glycidoxypropyltrimethoxydecane, 3-glycidoxypropylmethyldimethoxydecane, 3-mercaptopropyltrimethyl Oxydecane and a combination of two or more thereof. In other suitable decanes, R has from 8 to 18 carbon atoms and R' is one or more of chlorine, methoxy, ethoxy or hydroxy.

In one embodiment, the white pigment comprises Type II pulverized particles as classified according to ASTM Test D476. For example, in one embodiment, the white pigment comprises particles comprising surface treatments that produce powdering resistant properties, such as metal oxide particles. For example, the particles may comprise rutile type II Titanium oxide. The above white pigment particles maximize the initial reflectance increase of the resulting polymeric material while minimizing the effect of such particles on the melt viscosity of the material.

The surface treatment of the white pigment can be changed as long as the particles have the desired powdering resistance characteristics. In one embodiment, for example, the white pigment comprises titanium dioxide particles comprising a surface treatment comprising alumina. The surface treatment may comprise alumina, alone or in combination with other components. For example, in one embodiment, the surface treatment comprises a combination of alumina and polyoxyalkylene.

The white pigment may have a neutral hue or a blue hue as a whole. In one embodiment, the particles are slightly alkaline when combined with distilled water and measuring the pH. For example, white pigment particles can exhibit a pH above about 7, such as above about 7.5. The pH of the particles is generally below about 9, such as below about 8.5.

The polymer compositions of the present invention may also optionally contain one or more reinforcing agents such as fillers and fibers. Such materials may include, for example, glass fibers, ash, potassium titanate, calcium carbonate, talc, mica, ceria, kaolin, and the like. The inorganic fillers may be present in the composition in an amount from about 1% to about 40% by weight, such as from about 10% to about 30% by weight.

In accordance with the present invention, the composition may further optionally contain one or more reactive modifiers which act as stabilizers. For example, the reactive modifier can comprise a material, such as a polymer, that is capable of reacting with a thermoplastic polymer, such as a PCT polymer. The reactive modifier can provide one or more benefits. For example, in one embodiment, a reactive modifier The thermoplastic polymer can be made compatible with any other components present, especially during the melt processing.

In one embodiment, the reactive modifier comprises a material that is reactive with carboxyl or hydroxyl end groups on the thermoplastic polymer. In this way, the reactive modifier can act as a chain extender.

In one embodiment, the reactive modifier comprises a compound, oligomer or polymer having one or more functional groups. The one or more functional groups can be reacted with the thermoplastic polymer contained in the composition. The functional groups which may be present on the reactive modifier include an epoxy group, a carboxylic anhydride group, a hydroxyl group, a carboxyl group and/or an isocyanate group. In one embodiment, the reactive modifier comprises a chain extender attached to the thermoplastic polymer.

The reactive modifiers which can be used in accordance with the invention generally comprise a phenoxy resin and/or an epoxy resin, such as a non-aromatic epoxy resin. In one embodiment, for example, the reactive modifier comprises a modified phenoxy resin capable of reacting with a thermoplastic polymer. For example, the phenoxy resin can include a hydroxyl functional group. For example, the phenoxy resin can have a glass transition temperature of less than about 120 °C, such as less than about 110 °C, such as less than about 100 °C. The phenoxy resin can have a viscosity of less than about 2500 cP, such as less than about 2300 cP, when tested at 25% NV in cyclohexanone.

Non-aromatic epoxy resins useful as reactive modifiers include 3,4-epoxycyclohexenylmethyl-3',4'-epoxycyclohexenecarboxylate, 1,4- Cyclohexane dimethanol diglycidyl ether, hydrogenated bisphenol A type epoxy resin and/or ginseng (2,3-epoxypropyl) isocyanurate. In general, any suitable alicyclic epoxy resin can be used.

In addition to or instead of the above-described reactive modifier, the composition may contain an epoxy functional copolymer as a reactive modifier. Exemplary copolymers having a plurality of pendant epoxy groups include one or more ethylenically unsaturated monomers (e.g., styrene, ethylene, and the like) and an epoxy-containing ethylenically unsaturated monomer (e.g., C1- The reaction product of 4 (alkyl) glycidyl acrylate, alkyl glycidyl ethacrylate and glycidyl itaconate. For example, in one embodiment, the epoxy functional copolymer is a styrene-acrylic acid copolymer (including oligomers) comprising a glycidyl group incorporated in a side chain form.

In one embodiment, the reactive modifier may comprise an acid anhydride. Examples may include pyromellitic dianhydride, trimellitic anhydride, 3-(triethoxydecyl)propyl succinic anhydride, and the like. Other reactive modifiers can include various oxazolines and/or decanes. The reactive modifiers may include phenylbisoxazoline and 3-aminopropyltriethoxydecane.

The one or more reactive modifiers may be present in the composition in an amount sufficient to stabilize the viscosity of the composition during the melt processing without causing viscosity fluctuations. In other embodiments, the one or more reactive modifiers may be present in the composition in an amount sufficient to cause the composition to exhibit desirable whiteness properties, such as desired whiteness properties after heat aging. Generally, the reactive modifier is present in the composition in an amount from about 0.2% to about 8% by weight, such as from about 0.5% to about 5% by weight.

For specific advantages, a reactive modifier that does not significantly increase the yellowing of the composition over time can be selected. In this regard, the polymer composition can be formulated to be substantially free or completely free of various aromatic epoxy resins. In a real In the examples, for example, the composition does not contain any novolac epoxy resin, such as a cresol novolac epoxy resin.

Useful reactive modifiers that do not significantly increase the yellowing of the molded article made from the composition can include reactive modifiers that do not have a dark color. For example, the reactive modifier can have a color b ^* value of less than about 2, according to the CIELAB test method. The CIELAB method is described in F.Cost, Pocket Guide to Digital Printing, Delmar Publishers, Albany, NYISBN 0-8273-7592-1, pages 144 and 145; and "Photoelectric color difference meter", Journal of Optical Society Of America, Vol. 48, pp. 985-995, S. Hunter, (1958), which is incorporated herein by reference in its entirety. More specifically, the CIELAB test method defines three "Hunter" scale values L ^* , a ^*, and b ^* based on the color perception relativity, which correspond to the three characteristics of the perceived color and are defined as follows: L ^* = lightness (or luminosity), in the range of 0 to 100, where 0 = dim and 100 = bright; a ^* = red / green axis, in the range -100 to 100; positive is red and negative is green; And b ^* = yellow / blue axis, in the range of -100 to 100; positive value is yellow, and negative value is blue.

The DataColor 650 spectrophotometer can be used to measure color by using an integrating sphere using measurements including mirror mode. The color coordinates can also be calculated using the CIELAB unit under the illuminator D65/10°, A/10° or F2/10° observer according to ASTM D2244-11.

The polymer composition of the present invention may further comprise one or more impact modifiers. The impact modifier can be reacted with a thermoplastic polymer such as a PCT polymer or is non-reactive. In one embodiment, for example, the composition contains at least one reactive impact modifier and at least one non-reactive impact modifier.

Useful reactive impact modifiers include ethylene-maleic anhydride copolymers, ethylene-alkyl (meth)acrylate-maleic anhydride copolymers, ethylene-alkyl (meth)acrylate-( Glycidyl methacrylate copolymers and analogs thereof. In one embodiment, for example, a reactive impact modifier comprising a random terpolymer of ethylene, methacrylate, and glycidyl methacrylate is used. The terpolymer may have a glycidyl methacrylate content of from about 5% to about 20%, such as from about 6% to about 10%. The terpolymer may have a methacrylate content of from about 20% to about 30%, such as about 24%.

In particular, the inventors of the present invention have discovered that the combination of a reactive impact modifier and a reactive modifier can further improve the whiteness of articles made in accordance with the present invention after heat aging in some embodiments. index.

In general, the reactive impact modifier can be present in the composition in an amount from about 0.05% to about 20% by weight, such as from about 0.1% to about 5% by weight.

Non-reactive impact modifiers which may be incorporated into the polymer compositions of the present invention generally include various rubber materials such as acrylic rubber, ASA rubber, diene rubber, organic silicone rubber, EPDM rubber, SBS or SEBS rubber, ABS rubber, NBS rubber and the like. In one embodiment, There is an ethylene acrylic rubber such as an ethylene acrylate copolymer. Specific examples of the non-reactive impact modifier include ethylene butyl acrylate, ethylene (meth) acrylate or 2-ethylhexyl acrylate copolymer. In a particular embodiment, the ethylene (meth) acrylate copolymer is present in the (meth) acrylate containing composition in an amount from about 20% to about 30% by weight, such as from about 24% by weight. .

In a particular embodiment, the compositions of the present invention comprise a combination of an ethylene (meth) acrylate copolymer and a terpolymer of ethylene, methacrylate, and glycidyl methacrylate.

When present in the composition, the non-reactive impact modifier can be included in an amount from about 0.05% to about 15% by weight, such as from about 0.1% to about 8% by weight.

As stated above, the polymer composition of the present invention may contain a mixture of thermoplastic polymers. For example, in one embodiment, the composition can contain a PCT polymer in combination with one or more thermoplastic polymers. Other thermoplastic polymers may be present in an amount from about 1% to about 15% by weight. Other thermoplastic polymers that may be included include other polyester polymers, liquid crystal polymers, or mixtures thereof. Other thermoplastic polyester polymers that may be included in the composition include poly(ethylene terephthalate), poly(trimethylene terephthalate), poly(butylene terephthalate), acid modification PCT copolyester, poly(ethylene naphthalate), poly(butylene naphthalate); aliphatic polyesters such as polyester glutarate, and the like. In some embodiments, the incorporation of small amounts of other polyester polymers or liquid crystal polymers improves the handleability of the composition. In one embodiment, for example, the composition can be from about 2% to about 15% by weight The amount contains an aromatic liquid crystal polyester polymer.

Another additive that may be present in the polymer composition is a polytetrafluoroethylene polymer. The incorporation of a polytetrafluoroethylene polymer enhances the reflectance and whiteness index of articles made from polymer compositions. A polytetrafluoroethylene polymer in the form of a fine powder having an average particle size of less than about 50 microns, such as less than about 10 microns, can be added to the composition. In one embodiment, for example, the polytetrafluoroethylene powder can have an average particle size of from about 1 micron to about 8 microns. The polytetrafluoroethylene polymer can be present in the composition in an amount from about 0.05% to about 10% by weight, such as from about 0.1% to about 6% by weight.

In one embodiment, the polymer composition can also include a lubricant. The lubricant may comprise, for example, a polyethylene wax, a guanamine wax, a montan acid ester wax, a polyol ester or the like. In certain embodiments, for example, the lubricant can comprise polyethylene glycol dilaurate and/or neopentyl glycol dibenzoate. In a particular embodiment, the lubricant can comprise an oxidized polyethylene wax. The polyethylene wax may have a density of from about 0.94 g/cm ³ to about 0.96 g/cm ³ . When present, the lubricant can be included in the composition in an amount from about 0.05% to about 6% by weight, such as from about 0.1% to about 4% by weight.

In addition to the above, the composition may also contain various other additives and ingredients. For example, the composition may contain various heat stabilizers and oxidation stabilizers, ultraviolet light stabilizers, brighteners, and the like. In a particular embodiment, the composition can include a suitable optical brightener, such as benzoxazole. For example, the composition may include 2,2'-(1,2-exetylenedi-4,1-phenylene) bisbenzoxazole having a CAS accession number of 1533-45-5. Or another suitable benzoxazole. Optical brighteners can further increase reflectivity.

In one embodiment, the polymer composition can contain a sterically hindered amine light stabilizer. When present in a composition, hindered amine light stabilizers have been found to provide various advantages and benefits. For example, sterically hindered amine light stabilizers have been found to further improve the reflectivity properties of materials, especially after prolonged aging. The light stabilizer may be present in the composition in an amount from about 0.05% to about 3% by weight, such as from about 0.05% to about 1% by weight. In a particular embodiment, the hindered amine light stabilizer can be used in conjunction with a hindered phenolic antioxidant and a phosphorus containing stabilizer.

In one embodiment, the phosphorus-containing stabilizer may comprise an organophosphorus compound containing at least one phosphorus having a +5 valence state. For example, the organophosphorus compound can comprise a phosphonate or a phosphate. The phosphorus-containing stabilizers as described above have been found to significantly improve whiteness stability while retaining the ability of the polymer composition to adhere to the polyoxynoxy resin.

Phosphonate stabilizers provide the above benefits when included in relatively small amounts in the polymer composition. For example, the organophosphorus compound can be present in an amount less than about 5% by weight, such as in an amount less than about 3% by weight, such as in an amount less than about 2% by weight, such as even less than about 1% by weight. Present in the polymer composition. For example, the organophosphorus compound can be present in the polymer composition in an amount from about 0.01% to about 3% by weight, such as from about 0.01% to about 2% by weight.

In one embodiment, the stabilizer may comprise an organophosphorus compound having the following phosphorus groups:

In one embodiment, a phosphonate stabilizer having the formula: Wherein R1 is H, C1-C20 alkyl, unsubstituted or substituted by C1-C4 alkyl phenyl or naphthyl; R2 is H, C1-C20 alkyl, unsubstituted or substituted by C1-C4 alkyl Phenyl or naphthyl, or M ^r+ _r , wherein M ^r+ is a r-valent metal cation or ammonium ion; n is an integer from 0 to 6, and r is an integer from 1 to 4; A is hydrogen, -XC(O) -OR8 or the following groups: R3 or R4 is H, C1 to C18 alkyl, OH, halogen or C3-C7 cycloalkyl; R5 or R6 is hydrogen, C1-C4 alkyl, cyclohexyl or substituted by 1 to 3 C1-C4 alkyl Cyclohexyl; R7 is hydrogen, methyl, trimethyldecyl, benzyl, phenyl, sulfonyl or C1-C18 alkyl; R8 is hydrogen, C1-C10 alkyl or C3-C7 cycloalkyl; And X is a phenyl group or a phenyl group or a cyclohexyl group substituted by a C1-C4 alkyl group.

Specific examples of phosphonates which can be used according to the invention include phenylphosphonates and phenylmethylphosphonates, such as diethyl 1-phenylethylphosphonate, diethyl 2-phenylethylphosphonate, benzene Diethyl methylphosphonate or a mixture thereof. Specific phosphonate compounds include, for example:

In another embodiment, a phosphate stabilizer having the formula: O = P(OR ₁ )(OR ₂ )(OR ₃ ) is used.

When a phosphate stabilizer is used, the phosphate stabilizer may comprise an organophosphorus compound having the same phosphorus group as described above. In one embodiment, the phosphate stabilizer may have the formula: Wherein R ₁ , R ₂ , R ₃ and R ₄ are H, C1-C20 alkyl, unsubstituted or substituted by C1-C10 alkyl phenyl or naphthyl; m is an integer from 1 to 10; Q is as follows Group: ; ;*-(CH ₂ ) _p -*; p is an integer from 1 to 4.

Specific examples of phosphates which can be used in accordance with the invention include triphenyl phosphate, tributyl phosphate, tricresyl phosphate, 2-ethylhexyl phosphate diphenyl ester, toluene phosphate diphenyl ester, oligoethyl phosphate Ethyl ester, bisphenol A bis (diphenyl phosphate), resorcinol bis (diphenyl phosphate) or a mixture thereof.

To make the article of the present invention, in one embodiment, the polymer composition can comprise a melt blended blend wherein all of the polymeric components are sufficiently dispersed within each other and all of the non-polymeric components are sufficiently dispersed in the polymer matrix and polymerized The matrix is combined to form a uniform monolith.

Any melt mixing method can be used to combine the polymeric component with the non-polymerized component. For example, in one embodiment, the polymeric component and the non-polymeric component can be added to a melt mixer, such as a single screw extruder or twin screw extrusion. In a machine, blender, kneader or Banbury mixer, all materials are added in a single step or in a stepwise manner, followed by melt mixing.

The blended composition can then be molded into any desired shape via any suitable molding process. For example, in one embodiment, the article is formed via injection molding. The temperature of the composition may range from about 280 °C to about 350 °C during injection molding. Alternatively, the temperature of the mold can range from about 80 °C to about 150 °C.

In one embodiment, the polymer composition may have a lower melt viscosity at 305 ° C at a shear rate of 1000 s ^-1 (ASTM test D-3835-08) when measured by a capillary rheometer. About 200 Pa. s, such as less than about 150 Pa. s, such as less than about 100 Pa. s, such as less than about 80 Pa. s, such as less than about 70 Pa. s, such as less than about 60Pa. s. In general, the melt viscosity of the polymer under the above conditions is higher than about 10 Pa. s, such as above about 20 Pa. s. In a particular embodiment, the melt viscosity is about 40 Pa. s to about 80 Pa. s.

As noted above, the polymer compositions of the present invention are particularly well suited for the manufacture of reflectors for LED components. The reflectivity properties of polymers are especially well suited for white LEDs. The LED reflector can be in the form of a single piece or can be formed from two or more sub-components. In one embodiment, the polymer composition is injection molded onto the leadframe as shown in Figures 1 and 2. In this way, the lead frame and the reflector are integrated. The semiconductor light emitting diode wafer can then be mounted within the reflector pocket and connected to the leadframe. Wires can be used to bond the LEDs to the lead frame. The entire component can be wrapped, or a core material such as a solid epoxy that can form a lens for focusing light in a single direction can be used Fill the pocket defined by the reflector.

The molded article manufactured according to the present invention not only exhibits good adhesion properties to resins such as polyfluorene oxide and epoxy polymers, but also exhibits excellent light reflection properties and photostability properties. When testing the bond strength to the polyoxyxene resin, for example, according to the Lap-Shear Test, the polymeric composition can exhibit a force greater than about 25 pounds, such as greater than about 40 pounds force. For example, a poly-xylene bond strength of greater than about 50 pounds of force, such as even greater than about 60 pounds of force. The lap-shear force test is described in more detail in the examples below.

LED assemblies made in accordance with the present invention can be used in many different applications. For example, LED components can be used in traffic lights, LCD displays, backlights, cellular phones, automotive display lights, automotive headlights, flashlights, interior lighting, street lighting, and exterior lighting applications.

In addition to being used in LED modules, the polymer compositions of the present invention can also be used to make a variety of other articles. For example, the polymer composition can be used to make any article that requires good refractive index properties. For example, molded articles made in accordance with the present invention can be used in signs and indicia to improve the visual appearance of the article. In one embodiment, for example, a molded article made in accordance with the present invention can be used for a light sign, such as an exit sign.

Other applications for polymer compositions include use as a roofing material or as a component in solar cells. The polymer composition can also be used to make decorative sheets and instrument front covers for consumer products such as consumer devices. In other embodiments, the polymer composition can be used to mold interior trim panels of a vehicle, such as a car.

The invention will be more fully understood with reference to the following examples. Below to explain The following examples are provided instead of in a limiting manner.

Example 1

Table 1 below shows the melt compounding by using a 32 mm twin-scruder operated at 300 ° C using a screw speed of about 350 rpm and a melting temperature of about 320 ° C to about 330 ° C. Various compositions prepared in the components shown in the table. After exiting the extruder, the composition was cooled and granulated.

The compositions were molded into ISO stretch bars according to ISO method 527-1/2 using a mold temperature of about 120 °C. The tensile properties of the samples were determined using the above test methods. Charpy impact strength and Notched Charpy impact strength were measured according to ISO test 179.

The initial reflectance of each composition at 460 nm was determined by a spectrophotometer DataColor 600 using ASTM Test Method E1331 at 10° using a CIE D65 daylight illuminator. The tensile bars were measured. The higher the reflectance value, the less light absorption or light loss.

The initial whiteness index and the whiteness index after aging were determined based on WI E313 using the same reflectance scan. The higher the whiteness index value, the better the whiteness.

Get the following results:

As shown in the above table, the polymer composition of Sample 1 contained no reactive modifier. On the other hand, Sample 2 contained a cresol novolac epoxy resin. In Sample 2, the whiteness index was severely lowered after aging.

Compositions made in accordance with the present invention exhibit excellent initial reflectance, excellent initial whiteness index and exhibit excellent whiteness index properties after aging.

Example 2

Table 2 below shows the melt compounding shown in the table by using a 32 mm twin screw extruder operating at about 300 ° C, using a screw speed of about 300 rpm and a melting temperature of about 320 ° C to about 330 ° C. Various compositions prepared as components. After exiting the extruder, the composition was cooled and granulated.

The compositions were molded into ISO stretch bars according to ISO method 527-1/2 using a mold temperature of about 120 °C.

In the examples, the phosphonate stabilizer used is bis[monoethyl(3,5-di-t-butyl-4-hydroxybenzyl)phosphonate] calcium. The phosphate stabilizer used was triphenyl phosphate.

Table 3 below describes the properties of the compositions shown in Table 2. The tensile properties were determined using the test methods described above. The Charpy impact strength and the notched Charpy impact strength were measured in accordance with ISO test 179.

The reflectance of each composition at 460 nm was measured by a spectrophotometer DataColor 600 using the ASTM E1331 method and using a CIE D65 daylight illuminator at 10°. The tensile bars were measured. The higher the reflectance value, the less light absorption or light loss. The total reflectance is 100%.

The whiteness index (WI) was determined based on WI E313 using the same reflectance scan. The WI of each composition was also measured for tensile bars at 200 ° C for 4 hours heat aging. The higher the WI value, the better the whiteness is indicated.

The polyoxymethylene adhesion was tested according to the peel test and according to the lap-shear force test. According to the peeling test, the polyoxyxylene resin was mixed and cast into a layered structure on the above-mentioned stretched strip. The polyoxyxylene resin used was Dow Corning SYLGARD 577A/B (at a 10:1 ratio). The above polyoxyxylene resin is a polyoxyxene elastomer. Once the polyoxyxene resin was applied to the stretched strip, the part was cured in an oven at 180 ° C for 15 minutes, then removed from the oven and cooled to room temperature. The polysilicon layer was manually peeled off to check for adhesion. If the polyoxynitride layer is easily peeled off, the test fails. However, if it is not possible to manually remove the polyoxyl oxide, the adhesion to the polyoxygen is passed.

The second polyoxygen adhesion test method is a lap-shear force test. The PCT composition was molded into an ISO stretch strip. The strip is then cut into half. Two and a half The segment is placed on a 2" copper strip with a polyoxygenated adhesive layer to adhere the copper strip to the test piece. The polyoxyxene adhesive used is an LED sealed polyfluorene, which is Dow Corning OE 6630A/B polyoxyl resin. The two parts of the polyoxyl resin were mixed at a ratio of 1:4. The half strip and the copper strip were cured at 150 ° C for 2 hours, followed by cooling. At room temperature (23 ° C) by a stretching machine at 1 吋 / min The speed test has been combined with the tensile strip to obtain the peak load of the combined fracture. In detail, the half of the stretched strip is placed in the jaw of the stretcher. When one of the half is released from the copper strip, The peak load is recorded. Figure 5 illustrates the joining of the two halves of the copper strip from the polyoxynoxide.

As indicated above, compositions made with phosphonate or phosphate stabilizers exhibit improved reflectance stability and polyoxymethylene adhesion.

These and other modifications and variations of the present invention can be made by those skilled in the art without departing from the spirit and scope of the invention. The spirit and scope of the invention are set forth in the appended claims. Moreover, it should be understood that aspects of the various embodiments may be interchanged in whole or in part. In addition, it is to be understood by those skilled in the art that the present invention is described by way of example only.

10‧‧‧LED components

12‧‧‧Lighting diode/LED

14‧‧‧First wiring

16‧‧‧Second wiring

18‧‧‧ lead frame

20‧‧‧First lead frame section

22‧‧‧Second lead frame section

24‧‧‧Anode / First Terminal

26‧‧‧ Cathode / Second Terminal

28‧‧‧ reflector

30‧‧‧ recesses

32‧‧‧ side wall

34‧‧‧ side wall

36‧‧‧End wall

38‧‧‧End wall

50‧‧‧LED components

52‧‧‧LED

54‧‧‧ recess

56‧‧‧ reflector

58‧‧‧ lead frame

60‧‧‧Transparent materials

1 is a perspective view of one embodiment of an LED assembly made in accordance with the present invention; FIG. 2 is a plan view of the LED assembly illustrated in FIG. 1; and FIG. 3 is a perspective view of another embodiment of an LED assembly fabricated in accordance with the present invention. Figure 4 is a perspective view of one half of the mold used to measure the length of the spiral flow; and Figure 5 is a perspective view of the sample constructed in accordance with the lap-shear force test to measure the strength of the polyoxygen bond.

The reference numbers in the present specification and drawings are intended to represent the same or similar features or devices of the invention.

10‧‧‧LED components

12‧‧‧Lighting diode/LED

14‧‧‧First wiring

16‧‧‧Second wiring

18‧‧‧ lead frame

20‧‧‧First lead frame section

22‧‧‧Second lead frame section

24‧‧‧Anode / First Terminal

26‧‧‧ Cathode / Second Terminal

28‧‧‧ reflector

30‧‧‧ recesses

32‧‧‧ side wall

34‧‧‧ side wall

36‧‧‧End wall

38‧‧‧End wall

Claims (24)

A polymer composition comprising: a thermoplastic polymer having a melting point above about 260 ° C, the thermoplastic polymer comprising a poly(1,4-cyclohexanedimethanol terephthalate) polymer, the thermoplastic The polymer is combined with a white pigment and with at least one reactive modifier having an initial reflectance of greater than about 90% at 460 nm and greater than about 60 after aging for 4 hours at 200 °C. % whiteness index retention rate. The polymer composition of claim 1 wherein the polymer composition has a whiteness index above about 50 after aging for 4 hours at 200 °C. The polymer composition of claim 1 wherein the polymer composition has an initial whiteness index of greater than about 84. The polymer composition of claim 1 wherein the polymer composition has an initial whiteness index greater than about 84, and wherein the polymer composition has a whiteness greater than about 60 after aging for 4 hours at 200 °C. index. The polymer composition of claim 1 wherein the polymer composition has a whiteness index above about 50 and an initial whiteness index above about 84 after aging for 4 hours at 200 °C. The polymer composition of claim 1, wherein the polymer composition has a shear rate of 1,000/s and a 305 ° C of less than about 200 Pa. The fused viscosity of s. The polymer composition of claim 1, wherein the polymer composition has a shear rate of 1,000/s and a 305 ° C of less than about 100 Pa. The fused viscosity of s. The polymer composition of claim 1, wherein the reactive modifier comprises a polymer having a functional group reactive with a hydroxyl group or a carboxyl group. The polymer composition of claim 1 wherein the reactive modifier has a color b* of less than about 2, according to a CIELAB colorimetric scale. The polymer composition of claim 1, wherein the reactive modifier comprises a phenoxy polymer, an epoxy polymer, an anhydride polymer or a decane polymer. The polymer composition of claim 1, wherein the reactive modifier comprises 3,4-epoxycyclohexenylmethyl-3',4'-epoxycyclohexenecarboxylate, 1, 4-cyclohexanedimethanol diglycidyl ether, hydrogenated bisphenol A type epoxy resin or ginseng (2,3-epoxypropyl) isocyanurate. The polymer composition of claim 1 wherein the reactive modifier comprises a modified phenoxy resin. The polymer composition of claim 1, wherein the reactive modifier comprises pyromellitic dianhydride, trimellitic anhydride, 3-(triethoxydecyl)propyl succinic anhydride, and phenyl phenyl Oxazoline or 3-aminopropyltriethoxydecane. The polymer composition of claim 1 further comprising an impact modifier. The polymer composition of claim 14, wherein the impact modifier comprises a reactive impact modifier. The polymer composition of claim 1, wherein the polymer composition further comprises a polybutylene terephthalate polymer, a polyethylene terephthalate polymer, a polytetrafluoroethylene polymer, or a mixture thereof. The polymer composition of claim 1 wherein the white pigment is present in the polymer composition in an amount from about 10% to about 30% by weight, and wherein the polymer composition further comprises from about 10% by weight to A glass fiber in an amount of about 30% by weight. The polymer composition of claim 1 wherein the polymer composition has a polyoxymethylene bond strength of greater than about 25 pounds force, as measured by a lap-shear force test. A molded article made from a polymer composition comprising: a thermoplastic polymer having a melting point above about 260 ° C, the thermoplastic polymer comprising poly(1,4-cyclohexane) a methanol terephthalate) polymer in combination with a white pigment and with at least one reactive modifier having an initial reflectance of greater than about 90% at 460 nm, and It has a whiteness index retention of more than about 60% after aging for 4 hours at 200 °C. The molded article of claim 19, wherein the polymer composition also has a shear rate of 1,000/s and a temperature of 305 ° C of less than about 200 Pa. The fused viscosity of s. A molded article of claim 19 or 20, wherein the polymer composition is aged at 200 ° C, has a whiteness index above about 50, and has an initial whiteness index above about 84. The molded article of claim 19, wherein the reactive modifier comprises a phenoxy polymer, an epoxy polymer, an anhydride polymer or a decane polymer. The molded article of claim 22, wherein the white pigment is about 10 weights The amount of % to about 30% by weight is present in the polymer composition, and wherein the polymer composition further contains glass fibers in an amount of from about 10% by weight to about 30% by weight. The molded article of claim 19 or 20, wherein the polymer composition further comprises an organophosphorus compound comprising the following phosphorus groups: Wherein R1 is H, C1-C20 alkyl, unsubstituted or substituted by C1-C4 alkyl phenyl or naphthyl; and R2 is H, C1-C20 alkyl, unsubstituted or C1-C4 alkyl Substituted phenyl or naphthyl, or M ^r+ _r , wherein Mr ⁺ is a r-valent metal cation or ammonium ion.