WO1996029365A1 - Vehicle exterior body panels prepared from diaryl fluorene carbonate polymers - Google Patents

Abstract

Exterior body panels for vehicles are prepared consisting essentially of (I) a carbonate polymer composition consisting essentially of (Ia) a diaryl fluorene carbonate polymer component and optionally (Ib) a second, different carbonate polymer component; the carbonate polymer composition (I) having an inherent viscosity as determined at 25 °C in methylene chloride at a polymer concentration of 0.5 g/dL in the range of from 0.30 to 0.47 dL/g and comprising from 10 to 50 mole percent diaryl fluorene moieties based on the total moles of multihydric diaryl fluorene and additional multihydric compound remnant moieties in the carbonate polymer composition. Also shown is a process for preparing such injection molded, vehicle exterior body panels. In particular, the injection speed in the process must be maintained below a certain critical level to provide excellent part appearance and avoid splay and discoloration effects in the parts. Exterior body panels can be injection molded for a range of vehicles including automobiles, trucks, recreational vehicles, and mobile homes, where these combinations of processability, heat resistance, toughness, light weight and recyclability are desired.

Description

VEHICLE EXTERIOR BODY PANELS PREPARED FROM DIARYL FLUORENE CARBONATE POLYMERS

This invention relates to exterior body panels for automobiles or other vehicles which are prepared from diaryl fluorene carbonate polymer compositions. More specifically, the diaryl fluorene carbonate polymers can be directly prepared copolymers or they can be blends of diaryl fluorene carbonate polymers with other carbonate polymers, preferably carbonate polymers based on bisphenol A (BA). It has been found that the diaryl fluorene carbonate polymer compositions having molecular weights and concentrations of diaryl fluorene moieties falling in specific critical ranges demonstrate surprisingly good combinations of properties including stability and resistance to melting at high temperatures, solvent resistance, impact resistance and physical strength that make them particularly well suited for use in preparing body panels for automobiles or other similar types of vehicles, particularly when preparing the body panels by an injection molding process. It is known in the art that 9,9-bis(4-hydroxyphenyl) fluorene (BHPF), one species of dihydroxyaryl fluorene, can be employed in the preparation of thermoplastic condensation polymers including diaryl fluorene carbonate polymers. For example, BHPF is disclosed to prepare random copolymers with bisphenol A and other bisphenols (U.S. Patent 3,546,165) and to prepare block copolymers with bisphenol A (U.S. Patent 3,128,264) and with diorganosiloxanes (U.S. Patent 3,781,378). A process for preparing BHPF homopolycarbonates is disclosed in JP 63-182,336 (1988) and reported to prepare polymers having high heat resistance, good transparency and a desirable refractive index, which polymers are proposed for use in lenses and automobile body panels.

A range of BHPF-containing carbonate polymers, including BHPF/BA copolymers have been reported and suggested for use in a number of applications. Japanese Patent Publication No. JP 02-304,741 (1990) discloses copolycarbonates of 20 to 90 weight percent BHPF with BA for use in the manufacture of polycarbonates for optical disks. Japanese Patent Publication No. JP 05-155,998 (1993) discloses carbonate polymers containing BHPF and aliphatic units. Japanese Patent Publication No. JP 05-228,350 (1993) discloses gas separation membranes prepared from copolymers of BHPF and BA. Japanese Patent Publication No. JP 06- 25,398 (1994) discloses the use of BHPF/BA (41 to 95 mole percent BHPF) copolymers for lenses. Japanese Patent Publication No. JP 06-25,399 (1994) discloses the use of BHPF/BA (1 to 40 mole percent BHPF) copolymers for laser card substrates. Japanese Patent Publication No. JP 06- 25,401 (1994) discloses the use of BHPF/BA (70 to 95 mole percent BHPF) copolymers for printed circuit applications.

In U.S. Patent 5,196,479 it is suggested to prepare blends comprising polyester, impact modifier and a high Tg carbonate polymers. The high Tg carbonate polymers suggested for use are required to have a Tg greater than 165^CC and can be based on any dihydroxy compound yielding such a carbonate polymer including a tetrahalo bisphenol such as tetrabromo bisphenol A, a tetraalkyl bisphenol, such as tetra methyl bisphenol A, a phenyl- substituted bisphenol such as bisphenol AP or a fluorene-containing bisphenol such as BHPF. It is noted that the high Tg carbonate polymer used in this blend could be a physical blend of a high Tg carbonate polymer and another carbonate polymer, noting that they may or may not be miscible. Among many other applications, these multicomponent blends are suggested for use in automobile body panels.

It would be desirable to have an improved body panel for automobiles and other vehicles having a good combination of properties including ease of production, recyclability, stability and resistance to melting at high temperatures, impact resistance, solvent resistance and physical strength.

The invention is an exterior body panel for a vehicle consisting essentially of (I) a carbonate polymer composition consisting essentially of (la) a diaryl fluorene carbonate polymer component and optionally (lb) a second, different carbonate polymer component; the carbonate polymer composition (I) having an inherent viscosity as determined at 25°C in methylene chloride at a polymer concentration of 0.5 g/dL in the range of from 0.30 to 0.47 g/dL and comprising from 10 to 50 mole percent, preferably from 35 to 40 mole percent, diaryl fluorene moieties based on the total moles of multihydric diaryl fluorene and additional multihydric compound remnant moieties in the carbonate polymer composition. Preferably the diaryl fluorene moieties in the diaryl fluorene carbonate polymer component are represented by the general formula:

( l)4 (R₂)4

(R4)4 (R3)4

wherein Rι, R₂, R₃, and R₄ independently in each occurrence are hydrogen, a C^C linear or cyclic alkyl, alkoxy, aryl or aryloxy radical or a halogen, more preferably Rι, R₂, R₃, and R are al hydrogen and the diaryl fluorene is a 9,9-bis (4-hydroxyphenyl) fluorene (BHPF) remnant moiety. In an alternative embodiment, the present invention is a process for preparing an injection molded, vehicle exterior body panel from a thermoplastic resin characterized in that the thermoplastic resin is the carbonate polymer composition (I) described above. The body panels for automobiles and other vehicles according to this invention are an important development in the efforts to replace metal or thermoset body panels with tough, light weight, high heat, recyclable engineering thermoplastics. These polymers are not only tough and very processable but are also sufficiently stable and heat resistant to withstand

5 the high temperatures of automotive painting ovens. Also of increasing importance is the ability to more easily recycle the scrap from production steps and and the final products themselves after their useful lives. The panels according to the present inventions are more suited to recycling than body panels from thermosets or multicomponent thermoplastic blends that contain a range of non-carbonate polymers that typically affect the recyclability. 0 Diaryl fluorene carbonate polymers are characterized by containing polymerized therein (in addition to carbonate precursor remnant units) moieties of one or more diaryl fluorene represented by the general formula below:

(Rl)4 (R₂)4

(R₄)4 (R3)4

wherein Ri, R₂, R₃, and R₄ independently in each occurrence are hydrogen, a C -C , preferably mm C - ₆, linear or cyclic alkyl, alkoxy, aryl or aryloxy radical, such as methyl, ethyl, isopropyl, cyclopentyl, cyclohexyl, methoxy, ethoxy, benzyl, tolyl, xylyl, phenoxy and/or xylynoxy, or a halogen (such as fluorine, chlorine and/or bromine). In preferred embodiments of the present invention Ri, R₂, R₃, and R are all hydrogen or Ri and R₂ are phenyl and R₃ and R₄ are hydrogen. mm. The key features of the carbonate polymers suitable for preparing the body panels of the present invention are the content of the diaryl fluorene moieties (monomer remnants) in the carbonate polymer composition together with the molecular weight. In alternative embodiments of the invention, the diaryl fluorene carbonate polymers can either consist of (in addition to carbonate precursor remnant moieties) solely multihydric diaryl fluorene monomer moieties or consist of (in addition to carbonate precursor remnant units)

35 both multihydric diaryl fluorene monomer moieties and moieties from additional multihydric condensation reactive monomer(s). In the case where the diaryl fluorene carbonate polymer consists solely of multihydric diaryl fluorene monomer moieties, the second, different carbonate polymer component (lb) must be employed to provide a diaryl fluorene content in the carbonate polymer composition (I) in the required range. In the case where the diaryl fluorene carbonate polymer consists of multihydric diaryl fluorene moieties and moieties from one or more additional multihydric condensation reactive monomers, the second, different carbonate polymer component (lb) may optionally be employed to obtain a diaryl fluorene content in the required range.

In a preferred embodiment of the present invention, a multihydric diaryl fluorene monomer, preferably a dihydroxyaryl fluorene monomer is used to prepare the diaryl fluorene carbonate polymer of the present invention. Dihydroxyaryl fluorene compounds are represented by the general formula below,

(R4.4 (R3)4

wherein Ri , R₂, R₃, and R independently in each occurrence are hydrogen, a C -C , preferably C^C., linear or cyclic alkyl, alkoxy, aryl or aryloxy radical, such as methyl, ethyl, isopropyl, cyclopentyl, cyclohexyl, methoxy, ethoxy, benzyl, tolyl, xylyl, phenoxy and/or xylynoxy, or a halogen (such as fluorine, chlorine and/or bromine). When Ri, R₂, R3, and R₄ in the general formula below are all hydrogen, the dihydroxyaryl fluorene is 9,9-bis (4-hydroxyphenyl) fluorene (BHPF). In a preferred embodiment of this invention Ri, R₂, R₃, and R₄ in the formula are all hydrogen and the dihydroxyaryl fluorene is 9,9-bis (4-hydroxyphenyl) fluorene (BHPF) or Ri and R₂ are phenyl and R₃ and R are hydrogen and the dihydroxyaryl fluorene is 9,9-bis(4- hydroxy-3-phenylphenyl) fluorene. Methods of preparing 9,9-bis (4-hydroxyphenyl) fluorene (BHPF) from fluorenone and phenol are known, as set forth in U.S. Patent 3,546,165. Other multihydric diaryl fluorene compounds can similarly be prepared from fluorenone or substituted fluorenones and appropriate phenols or other aromatic reactants.

As mentioned above, the diaryl fluorene carbonate polymers may contain moieties or remnants corresponding to the polymerized form of one or more additional multihydric condensation reactive monomers. In a preferred aspect of the invention the diaryl fluorene carbonate polymer contains moieties or remnants of one or more additional, condensation polymerizable dihydroxy compounds, more preferably dihydric phenols. Preferably the additional condensation polymerizable multihydric monomer(s) (and suitable moieties or remnants in the polymers) is (are) selected from the following list of suitable dihydric phenols: 2,2-bis(4-hydroxyphenyl) propane, hydroquinone, resorcinol, 2,2-bis-(4-hydroxyphenyl)-pentane, 2,4'-dihydroxy diphenyl methane, bis-(2-hydroxyphenyl)- methane, bis-(4-hydroxyphenyl)-methane, bis(4-hydroxy-5-nitrophenyl)-methane, 1 , 1 -bis-(4- hydroxyphenyl)-ethane, 3,3-bis-(4-hydroxyphenyl)-pentane, 4,4'-dihydroxydiphenyl, 2,6- dihydroxy naphthalene, bis-(4-hydroxyphenyl) sulfide, bis-(4-hydroxyphenyl) sulfone, 2,4'dihydroxy-diphenyl sulfone, 5'-chloro-2,4'-dihydroxydiphenyl sulfone, bis-(4-hydroxy- phenyl) diphenyl disulfone, 4,4'-dihydroxydiphenyl ether, 4,4'-dihydroxy-3,3'-dichloro diphenyl ether, and 4,4'-dihydroxy-2,5-diethoxydiphenyl ether.

Preferably, the diaryl fluorene carbonate polymer in the present invention is a carbonate copolymer of a multihydric diaryl fluorene, preferably a dihydroxyaryl fluorene, and bisphenol A. The desirable carbonate polymers for use in the body panels of the invention may comprise moieties or remnants that correspond in polymerized form to additional, condensation polymerizable multihydric monomers, including preferably dihydroxy compounds, more preferably the above-listed dihydric phenols, in addition to the the diaryl fluorene remnants or moieties.

When the additional optional condensation polymerizable multihydric monomer, preferably bisphenol A, is used in the diaryl fluorene carbonate polymer, to obtain the best combinations of properties in the most efficient production process, the multihydric diaryl fluorene compound is desirably employed in amounts of at least 10, more preferably at least 20, more preferably at least 30 and most preferably at least 35 mole percent, which mole percentage is based on the total moles of multihydric diaryl fluorene compound and additional multihydric monomer polymerized in the carbonate polymer. The multihydric diaryl fluorene compound is desirably employed in amounts of less than 90 mole percent, preferably less than 70, more preferably less than 50 and most preferably less than 45 mole percent, which mole percentages are based on the total moles of multihydric diaryl fluorene compound and additional multihydric monomer polymerized in the carbonate polymer.

When the carbonate polymer composition (I) is a blend of (la) diaryl fluorene carbonate polymer component and (lb) a second, different carbonate polymer component, such-blend can be prepared across only a limited range of diaryl fluorene carbonate polymer and bisphenol A carbonate polymer weight percentages to obtain the desired content of the diaryl fluorene moieties in the carbonate polymer composition (I) and the desired property balance. Unless otherwise specified, the term "weight percentage" as it is used herein with regard to the diaryl fluorene and second, different carbonate polymer components means the weight percentage of the diaryl fluorene or second, different carbonate polymer components based on total weight of those two components and ignoring any amounts of other fillers and additives. Within the limited range specified for the diaryl fluorene content, better heat resistance is obtained with higher diaryl fluorene carbonate polymer weight percentages while processability is improved and costs are lowered with lower diaryl fluorene carbonate polymer weight percentages.

The preparation of the diaryl fluorene carbonate polymers, including for example, polycarbonates and polyestercarbonates, is also known to those skilled in the art. In general, these carbonate polymers are preferably prepared from the multihydric diaryl fluorene, preferably dihydroxyaryl fluorene compounds, and optionally one or more additional multihydric monomers. As is known, these carbonate polymers are prepared by reacting the multihydric diaryl fluorene, preferably dihydroxyaryl fluorene, compounds and optionally o other multihydric monomers (or their condensation reactive derivative such as metal phenolate) with a condensation reactive carbonate precursor. As used herein, the terms multihydric diaryl fluorene monomers, dihydroxyaryl fluorene monomers and multihydric monomers include their condensation reactive derivatives such as metal phenolate or the like. Carbonate precursors suitable for use in preparing these carbonate polymers are 5 well known and include carbonic acid derivatives, phosgene, a haloformate, or a carbonate ester such as dimethyl carbonate or diphenyl carbonate. Diaryl fluorene carbonate polymers are prepared from these reactants by an appropriate process selected from one of the known polymerization processes such as the known interfacial, solution or melt processes. General techniques for preparing carbonate polymers are well known and described in the literature. 0 The choice of polymerization process to use to prepare the diaryl fluorene carbonate polymer depends on a number of factors, including particularly the physical properties of the raw materials used. For example, the melt process is not appropriate if the monomers to be used in the polymerization reaction break down or form crosslinks at the higher temperatures at which the melt process is carried out. The diaryl fluorene carbonate 5 polymer of the present invention is preferably prepared with an interfacial process or with a solution process.

In the so-called interfacial process, the multihydric diaryl fluorene component(s), preferably dihydroxyaryl fluorene, and optionally one or more additional multihydric monomers, are usually at least partially dissolved and partially deprotonated in an aqueous 0 base solution, and the carbonate precursor is dissolved by an organic solvent. A solution of aqueous base is formed from water and a base which may be selected from those including the alkali metal and alkaline earth metal phosphates, bicarbonates, oxides and hydroxides. A preferred base for preparing such a solution is a caustic soda such as NaOH or OH. Base imparts increased reactivity to multihydric, particularly dihydroxy, compounds by adjusting the 5 pH of the aqueous phase to a level at which the compound is at least partially converted to dimetal salt form. The pH of the aqueous phase is, as a result, adjusted to a level greater than 7.0, often to a pH in the range of 8.5 to 13.5. When polycarbonate is prepared from bisphenol-A, which is the monomer most widely used in commercial carbonate polymer production, the reaction between bisphenol-A and a carbonate precursor typically occurs at a temperature in the range of 25 to 40°C, and complete dissolution of bisphenol-A in the aqueous phase of the reaction mixture may be easily obtained at that temperature. However, multihydric diaryl fluorene compounds, particularly dihydroxyaryl fluorene, are not soluble to any significant degree in aqueous base at a temperature in the range which is ordinarily associated with the production of bisphenol-A polycarbonate. At a temperature of less than 50°C, for example, a mixture of aqueous base and BHPF at a concentration of above 0.05 M has the consistency of a viscous paste. If it is not practical, from the standpoint of material flow and handling on a plant scale, to utilize a reaction mixture where the dihydric diaryl fluorene compound is not at least substantially completely dissolved in the aqueous phase thereof, it may be necessary to appropriately adjust process conditions to the point where the monomer is more completely dissolved. For example, it may be necessary to use a higher temperature, such as in the range of from 50°C to 90°C. If the reaction mixture temperature is then higher than the boiling point of the organic solvent present in the reaction mixture, it may be desirable to run the reaction under pressure.

Solution of the multihydric diaryl fluorene compounds in the base may also be improved by adjusting the ratio of moles of base to moles of multihydric diaryl fluorene and other multihydric compounds (if any) in the carbonate polymer-forming reaction mixture. For example, the solubility of BHPF in the aqueous phase of a polycarbonate-forming reaction mixture is enhanced if the ratio of moles of base to moles of BHPF plus all other multihydric compounds present is from 2 to 3.85. When base in an amount as described above is used, the pH of the aqueous phase of the reaction mixture will be in the range of 12.0 to less than 14.0. Reaction of a multihydric diaryl fluorene compound, particularly BHPF, the optional additional multihydric monomer and the carbonate precursor under the conditions described above may be run in the absence of a phase transfer catalyst or using one. Typical phase transfer catalysts are quaternary phosphonium or ammonium salts, such as tetraethyl- ammonium chloride or tributylbenzylammonium chloride, crown ethers and cryptates. These are added to the reaction mixture, or to the aqueous phase thereof, before reaction with a carbonate precursor to enhance solubility of the multihydric diaryl fluorene compound, and to reduce or prevent precipitation of the multihydric diaryl fluorene compound, once it is dissolved, before the reaction occurs. The operation of phase transfer catalysts are described in greater detail in Kirk-Othmer, Encyclopedia of Chemical Technology, John Wiley & Sons (1979), volume 5, pages 62-69; Report AD-777 731 to the Naval Air Systems Command (January 1974), by Kambour and Niznik; U.S. Patent 3,546,165 and Japanese okai Publication 62-12,282 (1987). However, it is usually preferred to prepare polycarbonate from a multihydric diaryl fluorene compound, preferably including an optional additional multihydric monomer, by means of an interfacial process in which the multihydric diaryl fluorene compound is soluble in the aqueous phase of the reaction mixture and a phase transfer catalyst is not needed. In a preferred preparation process, the carbonate precursor excludes the phosgene dimer trichloromethylchloroformate (C.0₂CI₄).

As is known, these processes can be employed in batch or continuous reactor schemes. Process steps can be carried out in a single reaction vessel, or may be conducted independently in a series of individual reaction vessels wherein at least a portion of the reaction mixture prepared in a first reaction vessel in a first step is transferred to a second reaction vessel wherein another step is conducted, and so on throughout the process. The contemplated individual reaction vessels may additionally be continuous or batch reactors. Finally, the process may be conducted in a continuous reaction system, such as a tubular reactor, wherein the reaction system contains multiple reaction zones. General techniques for preparing carbonate polymers are well known and described in the literature.

Carbonate polymers which are suitable for use as optional second carbonate polymer component (lb), include carbonate polymers based on 2,2-bis(4-hydroxyphenyl) propane ("bisphenol A"), including for example, polycarbonates and polyestercarbonates. In general, these carbonate polymers and process for their preparation are well known in the literature and many are commercially available from a number of sources. Such polymers are typically prepared from one or more known condensation polymerizable multihydric monomers, including preferably dihydroxy compounds, more preferably dihydric phenols. Suitable dihydric phenols include, but are not limited to 2,2-bis(4-hydroxyphenyl) propane, hydroquinone, resorcinol, 2,2-bis-(4-hydroxyphenyl)-pentane, 2,4' -dihydroxy diphenyl methane, bis-(2-hydroxyphenyl)-methane, bis-(4-hydroxyphenyl)-methane, bis(4-hydroxy-5- nitropheny -methane, 1 , 1 -bis-(4-hydroxyphenyl)-ethane, 3,3-bis-(4-hydroxypheny l)-pentane, 4,4'-dihydroxydiphenyl, 2,6-dihydroxy naphthalene, bis-(4-hydroxyphenyl) sulfide, bis-(4- hydroxyphenyl) sulfone, 2,4'dihydroxy-diphenyl sulfone, 5'-chloro-2,4'-dihydroxydiphenyl sulfone, bis-(4-hydroxyphenyl) diphenyl disulfone, 4,4'-dihydroxydiphenyl ether, 4,4'-dihydroxy-3,3'-dichloro diphenyl ether, and 4,4'-dihydroxy-2,5-diethoxydiphenyl ether. As is also known, it is possible to employ chain terminating compounds, typically monophenols, in the preparation of both the diaryl fluorene and bisphenol A carbonate polymers to control the molecular weight in these polymers. Chain branching agents can also be employed in these polymers to provide branched products and modify the melt viscosities where desired to provide products that may be suitable for blow molding or thermoforming applications. Suitable chain branching agents, typically phenols having 3 or more hydroxyls, are known in the art and many are disclosed in U.S. Patents 3,544,514 (Re.27, 682); 4,695,620; 4,888,400; 5,104,964; and 5,367,044. In addition to employing diaryl fluorene carbonate polymers (la) comprising solely carbonate linking moieties and optional additional carbonate polymers (lb) comprising solely carbonate linking moieties in the body panels according to the present invention, it is also optionally possible to employ a diaryl fluorene polyestercarbonate (la) and/or optional additional polyestercarbonate (lb). As known, such polyestercarbonates can be prepared similarly to the preparation of the polycarbonate except additionally incorporating a glycol, a hydroxy terminated polyester, a dibasic acid, or the like, as a part of the multihydric monomer. Methods of producing polyestercarbonates are known in the prior art. In one aspect of the present invention, the diaryl carbonate polymer is a diaryl fluorene polyestercarbonate. Such diaryl fluorene polyestercarbonate preferably contains less than 50, more preferably less than 20, more preferably less than 10, and most preferably less than 5 percent of an ester linking group based on the total moles of ester plus carbonate linking groups.

In order to obtain body panels with especially good physical properties and a good surface appearance when employing the second, different carbonate polymer component (lb) in the carbonate polymer composition (I), it is preferred to select a combination of diaryl fluorene and second, different carbonate polymers such that a miscible blend of the diaryl fluorene and second, different carbonate polymers is prepared. Preferably such blends consist essentially of the diaryl fluorene carbonate polymer and a second, bisphenol A carbonate polymer, which second polymer is preferably a homopolycarbonate of bisphenol A (and carbonate precursor). Preferably, if a blend of carbonate polymers (la) and (lb) is employed, the diaryl fluorene carbonate polymer consists solely of one or more multihydric diaryl fluorene moieties or consists of one or more multihydric diaryl fluorene moieties with moieties of bisphenol A, also including, of course, a carbonate precursor in the carbonate polymers. In these cases very desirable miscible blends of the polymers result and provide especially preferred body panels according to the present invention.

As mentioned above, the carbonate polymer composition (I), whether solely a diaryl fluorene carbonate polymer component (la) or a blend of a diaryl fluorene carbonate polymer component (la) and a second, different carbonate polymer component (lb), must contain from 10 to 50 mole percent multihydric diaryl fluorene moieties which mole percentage is based on the total moles of multihydric diaryl fluorene and additional multihydric monomer remnant moieties in the carbonate polymer(s) in the composition (I). Unless otherwise specified, the term "mole percentage" as it is used herein with regard to the diaryl fluorene, bisphenol A or other monomeric moieties in the carbonate polymer component(s) means the mole percentage of such moieties in the carbonate polymer(s) based on total weight of those moieties and ignoring the carbonate precursor and any amounts of other polymers, fillers, impact modifiers and additives.

To obtain the best combinations of heat stability properties in the body panels according to this invention, the carbonate polymer composition (I) desirably contains the multihydric diaryl fluorene remnant(s) or moieties at levels of at least 15 mole percent, preferably at least 25 mole percent, preferably at least 30, preferably at least 32 mole percent, more preferably at least 35, and most preferably at least 36 mole percent, which mole percentages are based on the total moles of multihydric diaryl fluorene and other multihydric monomer moieties polymerized in the carbonate polymer composition (I).

To obtain the desirable processability and toughness contributions of the other multihydric monomer polymerized in the carbonate polymer composition (I), the carbonate polymer composition (I) desirably contains the multihydric diaryl fluorene in amounts of less than or equal to 50 mole percent, preferably less than or equal to 45 mole percent, preferably less than or equal to 40 mole percent, more preferably less than or equal to 30 mole percent, and most preferably less than or equal to 20 mole percent, which mole percentages are based on the total moles of multihydric diaryl fluorene and other multihydric monomer moieties in the carbonate polymer composition (I).

As mentioned above, the weight average molecular weight of the carbonate polymer compositions (I) suitable for use in the body panels according to the present invention must fall within a relatively narrow molecular weight range to obtain the desired balance of blend properties. As measured by determination of the polymer inherent viscosity (IV) at 25°C in methylene chloride at a concentration of 0.5 g/dL, the average molecular weight of polymer compositions (I) must result in IV values in the relatively narrow range of from 0.30 to 0.47 deciliters per gram (dL/g) in order to obtain a body panel having sufficient toughness, thermal stability and heat resistance properties. Within this relatively narrow molecular weight range, somewhat better processability is obtained with a lower molecular weight, higher melt flow rate thermoplastic having a lower IV value while toughness is typically improved as molecular weight is increased and the IV value is higher. In order to obtain a body panel having better toughness, thermal stability and heat resistance properties, it has been found to be even more preferred to use a carbonate polymer composition (I) having an IV value of at least 0.32 dL/g, and more preferably at least 0.35 dL/g. To obtain a polymer blend having good processability properties, it has been found desirable to use a carbonate polymer composition (I) having an IV value of less than or equal to 0.44 dL/g, preferably less than or equal to 0.43 dL/g, and most preferably less than or equal to 0.42 dL/g.

Similarly, the average molecular weight of the blend composition can also be measured directly by a number of known techniques. Unless otherwise specified, the term "molecular weight" as it is used herein means the weight average molecular weight as measured by size exclusion chromatography using a bisphenol A polycarbonate standard.

In orderto obtain a body panel having sufficient toughness, thermal stability and heat resistance properties, it has been found to be essential to use a carbonate polymer composition (I) having a weight average molecular weight determined by size exclusion 96/29365

chromatography using a bisphenol A polycarbonate calibration curve in the range of from 22,000 to 30,000. In order to obtain a body panel having better toughness, thermal stability and heat resistance properties, it has been found to be even more preferred to use a carbonate polymer composition (I) having a weight average molecular weight preferably at least 25,000, and more preferably at least 26,000. To obtain a polymer blend having good processability properties, it has been found desirable to use a carbonate polymer composition (I) having a weight average molecular weight of less than or equal to 28,000, preferably less than or equal to 27,000 and most preferably less than or equal to 26,000.

When the carbonate polymer composition (I) comprises a blend of components (la) and (lb), better miscibility and its attendant benefits can be expected if the molecular weights of the two components are reasonably close, for example they are within 20 percent of each other, preferably within 10 percent, based on the higher of the two molecular weights. It should be noted that the diaryl fluorene monomeric compound has a relatively high molecular weight per mer unit, resulting in somewhat lower degrees of polymerization in carbonate polymers having the same "molecular weight".

When the carbonate polymer composition (I) comprises a blend of components (la) and (lb), the blends can be prepared across a range of weight percentages to obtain the desired balance of blend properties but within the requirements for molecular weight and diaryl fluorene content. Unless otherwise specified, the term "weight percentage" as it is used herein with regard to the diaryl fluorene or second carbonate polymer components means the weight percentage of that carbonate polymer component based on total weight of those two components and ignoring any amounts of fillers and additives

In orderto obtain a polymer blend having good thermal stability and heat resistance properties, it has been found desirable to use diaryl fluorene carbonate polymer weight percentages of at least 1 , preferably at least 5, more preferably at least 10, more preferably at least 25 and most preferably at least 30 weight percent. For obtaining a polymer blend having better processability and toughness it has been found desirable to use diaryl fluorene carbonate polymer weight percentages of less than or equal to 99, preferably less than or equal to 90, more preferably less than or equal to 75, more preferably less than or equal to 50, and most preferably less than or equal to 45 weight percent.

In addition, other additives can be included in the carbonate polymer blends of the present invention such as fillers (including fibrous or particulate materials), pigments, dyes, antioxidants, heat stabilizers, ignition and drip resistant additives, ultraviolet light absorbers, mold release agents and other additives commonly employed in carbonate polymer compositions.

The body panels according to the invention can be prepared by any of a variety of known techniques but are preferably prepared by injection molding techniques, which are well known in the art. The following Experiments are given to further illustrate the invention and should not be construed as limiting its scope.

For the polymer analysis and evaluations of the compositions given below, standard experimental and test methods were used unless otherwise specified. Weight average molecular weight ("Mw") and number average molecular weight ("Mn") were determined on the samples by size exclusion chromatographic (SEC) analysis. Inherent viscosities ("IV") of the polycarbonates were determined at 25°C in methylene chloride (or chloroform in the case of diaryl fluorene polymers with high diaryl fluorene contents) at a concentration of 0.5 g/dL. Differential scanning calorimetry (DSC) was used to determine the glass transition temperatures (Tg's) of the polymers. Pellet samples ranging from 10 to 18 milligrams (mg) were weighed in DSC sample pans on an electronic balance. The samples were placed in a DuPont 912 Dual-Sample differential scanning calorimeter (DSC) purged with nitrogen. The method used involved equilibration at 100°C as a first step followed by scanning at 10°C or 20°C per minute (°C/min), as indicated in reported results, from 100°C to 350. Data analysis was performed on a DuPont Thermal Analyst 2100. Step transition was used to mark the start and end points of the glass transition temperature ranges on the plots followed by computer calculation of the midpoint Tg in °C for each.

The melt flow rate (MFR) values are measured according to ASTM D-1238, conditions of 300°C and 1.2 kilograms mass and are reported in grams per 10 minutes (g/ 10 min). The 1 H-NMR spectra (CDCI3/TMS) of the products were in agreement with the target copolycarbonate composition. Preparation of BHPF Polycarbonate Components

Polycarbonates of 9,9-bis(4-hydroxyphenyl) fluorene (BHPF) as the multihydric diaryl fluorene compound were prepared as follows.

A 2 liter (L) 4-neck round bottom flask equipped with a thermometer, condenser, phosgene/nitrogen inlet, and a paddle stirrer was charged with BHPF in an amount of 1 18.3 grams (g) equivalent to 0.338 moles (mol), 4-tert-butylphenol (TBP) (1.01 g, 0.0067 mol), pyridine (69.4 g, 0.878 mol), and chloroform solvent (1.0 L). The resulting solution was stirred at 250 revolutions per minute (rpm) and slowly purged with nitrogen as phosgene (34.4 g, 0.348 mol) was bubbled in over 28 minutes while maintaining the reactor temperature at 20- 26°C. During the final stages of phosgene addition, samples of the reaction mixture were added to a solution of 0.1 percent (by weight) of 4-(4-nitrobenzyl) pyridine in tetrahydrof uran to determine the reaction end point (the reaction of all of the phenolic compound and the presence of a slight excess of phosgene) by the formation of a yellow-colored solution.

The reaction mixture was worked up by adding methanol (5 mL) and then a solution of 30 mL of concentrated HCI in 90 mL water. After stirring for 15 min at 200 rpm, the mixture was poured into a 2 L separatory funnel and allowed to stand overnight. The chloroform layer containing the dissolved polymer was separated and washed further with a solution of 10 mL concentrated HCI in 200 mL water, followed by 200 mL water, and was then passed through a column of MSC-1-H ion exchange resin (0.5 L bed volume).

The polycarbonate product was isolated by adding one volume of the chloroform solution to four volumes of a hexane/acetone (1 /1 v/v) mixture in an explosion resistant Waring blender. The product was filtered, dried in a hood overnight, and then dried for 48 hr. in a vacuum oven at 120°C. The dried product weighed 1 14.6 g and had an IV of 0.405 dL/g (determined in chloroform at 0.5 g/dL and 25°C) and a Tg value of 288°C (midpoint second scan, 20°C/min heating rate). A second similarly prepared lower molecular weight sample (except for o the use of 1.52 g of TBP) was found to have an IV of 0.283 dL/g and a Tg value of 279°C (DSC, 20°C/min). The results of tests performed on the polycarbonates prepared as described above (Samples BHPF PC-A and BHPF PC-B) are summarized in Table 1.

A copolycarbonate of 60 mole percent 9,9-bis(4-hydroxyphenyl) fluorene (BHPF) as the diaryl fluorene and 40 mole percent bisphenol A (B A) as an additional multihydric 5 monomer was prepared as follows. The mole percent of each monomer used in the preparation process for this copolycarbonate was confirmed to be the mole percentage in the final product by NMR of the product.

To a 100 mL high pressure reactor with plug are added BA (0.913 g, 4.0 mmole), BHPF (2.102 g, 6.0 mmole), TBP (0.045 g, 0.30 mmole), aqueous 50 percent NaOH solution 0 (2.0 g, 25.0 mmole) and water (16.14 g). The reactor plug is loosely screwed in and a needle connected to a nitrogen source is then inserted through the injector port septum. Nitrogen gas is blown through the air space of the reactor for 10 minutes, then the plug tightened down. The sealed reactor is placed in a water bath (69-71^cC) and a magnetic stirrer is started. Within 15 minutes the monomer has dissolved. To this stirred mixture is added phosgene solution in 5 methylene chloride (20.08 g of 6.65 percent solution, 13 mmole) by 25 mL gas-tight syringe. The syringe is removed and the reaction mixture shaken for 30 seconds. A second shot of 50 percent NaOH (2.0 g, 25 mmole) is added by syringe through the septum.

The mixture is shaken 1 minute, then further methylene chloride (11.17 g) is added by syringe, followed by 4-dimethylamino pyridine (0.6 mL of a 1 percent aqueous 0 solution). This mixture is shaken 1 minute, then the reactor swirled in an ice bath. The reactor is opened, and the aqueous phase pipetted off. The organic phase is washed once with 1 N HCI and twice with water, and it is then evaporated on a petri dish to give a BHPF/BA copolycarbonate film.

The general procedure of this example was used in a continuous, plug-flow 5 reactor to prepare an additional quantity of BHPF/BA (60/40) copolycarbonate (Sample BHPF co-PC in Table 1 below) having a weight average molecular weight of 23,000, an IV of 0.32, and a Tg of 228°C (DSC, 20°C/min). The bisphenol A carbonate polymers used in the sample blend compositions below are commercially available polycarbonates and are also described and characterized in

Table 1 below. Sample BA PC-X is a 3 melt flow rate polymer based on bisphenol A and phosgene commercially available from The Dow Chemical Company as CALIBRE" 300-3. Sample B A PC-Y is a 10 melt flow rate polymer based on bisphenol A and phosgene commercially available from The Dow Chemical Company as CALIBRE" 300-10.

Table 1

Sample BHPF BA IV Number Mole % Mole % (dL/_R)

BHPF PC-A 100 - 0.405 288

BHPF PC-B 100 - 0.283 279

BHPF co-PC 60 40 0.32 228

BA PC-X (3 MFR) - 100 - 154

BA PC-Y (10 MFR) - 100 - 151

Experimental Blend Samples - Solution Blending of BHPF Polycarbonate and BA Polycarbonate A clear single-phase solution of BHPF PC-A and BA PC-X was prepared by adding 1 0 gram (g) each to 50 milliliters (mL) chloroform and shaking the mixture until the solids dissolved. A 5 mL aliquot of this solution was added to 200 mL of methanol and the resulting slurry was agitated for two hours on a mechanical shaker. The slurry was then filtered and the precipitated blend was air-dried and then dried in vacuo at 120°C overnight. DSC analysis (20°C/minute scan rate, second scan results, midpoint value) showed a single Tg for this blend at 206°C. By comparison, the two blend components had two distinctly different Tg values, the BHPF polycarbonate having a Tg of 288°C and the BA polycarbonate having a Tg of 154°C. This experiment indicates compatibility and miscibility of the diaryl fluorene and bisphenol A polycarbonates. This experiment is summarized in Table 2 below. Experimental Blend Samples - Melt Blends of BHPF Polycarbonate and BA Polycarbonate Dry blends of BHPF and BA polycarbonates were prepared by mixing the two components in weight ratios of 10/90, 50/50 and 90/10 at room temperature and drying for 3 hours at 130°C in an air circulating oven. The blends were then melt mixed in a Haake Torque Rheometer for 4 minutes at 200 rpm and 320°C. The Haake blend product was removed, chopped, and compression molded using a Tetrahedron press to prepare plaques having dimensions 25.4 mm x 25.4 mm x 3.2 mm (1 in x 1 in x 1 /8 in). Compression molding conditions were as follows: sample dried for 3 hours at 130°C and then placed in press at 320°C and 3.4 megaPascals (MPa) platen pressure (500 pounds per square inch - "psi") for 2 min, pressure raised to 207 MPa (30,000 psi) for 5 minutes, then cooled at 20°C/minute to room temperature. The mold and sample were sandwiched between thick aluminum foil with external steel backing plates. The molded plaques were then evaluated for percent haze ("% Haze") and percent transmitta nee (%T) using a HunterLab Colorquest instrument and Tg was determined using DSC at a 10°C per minute heating rate. The results of the evaluations of the solution blended composition (Blend Sample 1) and melt blended compositions (Blend Samples 2 through 4) are summarized below in Table 2.

Table 2

BHPF/BA Polycarbonate Blend Results Blend Number 1 2 3* 4* BHPF PC Sample No. A B B B

BA PC Sample X Y Y Y

Wt Ratio 50/50 50/50 90/10 10/90 (BHPF PC to BA PC)

Mole % BHPF 40.3 40.3 86.0 7.1 % Haze 3.0 2.8 2.2

% T 86.3 88.7 90.3

Component A Tg (°C) 288 279 279 279

Component B Tg (°C) 154 151 151 151

Blend Tg (°C) 206 203 256 159

*Not an example of polymers used according to the invention.

Melt Blends of BHPF/BA Copolycarbonate and BA Polycarbonate

Additional melt blends were prepared by combining amounts of the BHPF/BA coPC (60/40) with BA PC, incorporating also 1000 parts Phosphite 168 brand thermal stabilizer per million parts resin blend (ppm). Samples were produced containing 0, 4.5, 12.3, 26.5, 41.8, 52 and 60 mole percent BHPF in the final blend product. Extrusion compounding of the samples was performed on a 30 mm Werner-Pfleiderer extruder with the feed zone set at 200°C and the four remaining zones set at 310°C. After drying at 125°C for4 hours in a forced air oven, all samples were molded on a 55 ton Negri-Bossi molding machine. The molding temperature for all samples was set at 350°C. Injection pressures for the seven samples, given in order corresponding to increasing weight percent BHPF coPC, were 20, 20, 30, 45, 70, 90 and 165 bars. The holding pressures for the molding processes, similarly given in order corresponding to increasing weight percent BHPF coPC, were 20, 20, 25, 35, 65, 85 and 165 bars. Injection time was 5 seconds ("sec") for all samples; holding time was increased from 8 sec for the first 5 samples to 12 sec and 25 sec for the two final samples containing the highest percent BHPF. As can be seen above, increasing pressures and holding time forthe more viscous, higher BHPF samples were adjustments for better molding filling. These blends were evaluated according to the following techniques and the results are shown in Table 3.

The Izod impact resistance test method was used to evaluate the toughness of samples at ambient temperature using the 10 mil (0.25 mm) notch radius Izod test. Bars were notched using the Testing Machines Incorporated (TMI) notcher. They were subsequently tested on the TMI Izod Machine following ASTM standard D-256. The results are reported in foot-pounds per inch (Ft-lb/in) and Joules per meter (J/m).

For the tensile and f lexural strength testing, the samples used were 6 112 inch x 1/2 inch x 1 /8 inch (165.1 mm x 12.7 mm x 3.2 mm) dogbone-shaped bars. To measure tensile properties at ambient temperature, the Sintech 2 instrument was used according to ASTM standard D-638 with a 2000 pound (lb) (907.2 kilogram -"kg") load cell and D-638 extensometer at a loading rate of 2 inches per minute (in/min) (50.8 mm/min). Flex properties at ambient temperature were measured in accordance with ASTM standard D790 using a 200 lb (90.7 kg) load cell. The results are reported in pounds per square inch (psi) and megaPascals (MPa).

Deflection temperature under load (DTUL) at a load of 66 psi (0.46 MPa) was measured according to ASTM standard D-648 utilizing the Tinius Olsen Heat Distortion Bath for Vicat and DTUL testing and the Tinius Olsen Microprocessor-Controlled Automatic Deflection Temperature Tester. The 5 inch x 1 /2 inch x 1 /8 inch (127 mm x 12.7 mm x 3.2 mm) bars were ^used-

The haze value were measured and reported as "% Haze" for each of the materials by analyzing three disks of each material on the HunterLab Colorquest Sphere

Colorimeter. A blank was measured before testing began and mid-way through testing. The blank percent haze values were then deducted from sample results to obtain actual % haze for each sample. Average percent haze was calculated for each material from the three samples of each. Disk surface roughness, due to difficulty in molding higher viscosity samples, was observed to provide some degree of difficulty in obtaining complete comparable data. The solvent resistance of the samples was tested according to the known environmental stress failure resistance (ESFR) test method. In this experiment, samples under strain were exposed to a solvent to establish maximum strains before crazing occurred. A solvent system of 75 percent iso-octane/25 percent toluene was used with immersion time for all samples at 17 hours. Samples tested were 5 inch x 1/2 inch x 1/8 inch (127 mm x 12.7 mm x 3.2 mm) bars (cut in half) of BA PC-Y and BHPF coPC. Three bars of each of the two sample types were tested for crazing at strains of 0.002, 0.004, 0.006, and 0.008. Following this preliminary testing, two more bars were tested for each sample at 0.006 strain and three bars were tested for each at 0.007 strain in an attempt to establish a distinction between the critical strain values at which crazing occurs for each sample. Finally, bars of each of the two samples were annealed for 30 minutes at 20°C below Tg to remove " molded in" stresses. These annealed bars of each sample were then tested, again at 0.006 and 0.008 strains. Observation of crazing behavior at these strains led to final tests of annealed BA PC-Y bars at 0.005 strain and annealed BHPF coPC bars at 0.007 strain.

The solvent resistance of the samples was also tested by evaluation of the resistance to crystallization in toluene. In this test a thin sheet was compression molded from pellets (dried under vacuum overnight at 1 10°C) for each of the samples. A Tetrahedron MTP- 14 compression molding machine was used in conjunction with a rectangular 6 1 /8 inch x 6 inch x 1/64 inch (155.6 mm x 152.4 mm x θ.40 mm) mold. Four steps were programmed: (1) equilibration at 572°F and 0.5 psi (300°C and 3448 Pa) for one minute, (2) holding at these conditions for an additional minute, (3) holding at 572°F and 20 psi (300°C and 137,931 Pa) for 5 minutes, (4) annealing at 20°C below the Tg of each sample under 0.5 psi (3448 Pa) for 10 minutes to reduce molding stresses. Using a paper hole punch, the thin sheets were punched to generate samples for DSC analysis. These small circular pieces of each material were then placed in 100 percent toluene for 15 minutes. Upon removal, they were dried under vacuum overnight at 100°C. The materials were analyzed by DSC and a percent crystallinity value was calculated, based on polycarbonate heat of fusion (133 J/g). These results are shown in Table 3.

The blend samples 5 through 1 1 were further characterized by IV (determined in methylene chloride at 25°C and 0.5 g/dL) and by Dynatup impact resistance. The latter was conducted on a Dynatup Model 8000 drop tower according to ASTM D-3763-86 using a drop height of 12.0 in (304.8 mm) and a drop weight of 138.5 lb (305.3 kg). The specimens were undamped and were tested at 23°C. These results are shown in Table 3 below, which lists the maximum load in pounds (lb) and kilograms (kg) at the beginning of sample penetration, the energy associated with this maximum load in foot-pounds (ft-lb) and Joules (J), and total energy to break through the sample in this impact test in ft-lb and J.

6/29365

Table 3 -Blends of BA PC + BHPF CoPC

Blend No. 5* 6* 7 8 9 10* 11*

Weight Z BA 100 90 75 50 25 10 0 PC in Blend

WeightZ 0 10 25 50 75 90 100 BHPF CoPC in Blend

Mole Z BHPF 0 4.5 12.3 26.5 41.8 52.0 60.0 in Blend

IV 0.44 0.42 0.41 0.37 0.35 0.32 0.30 (dL/g)

Tg (°C) 153.8 158.9 168.3 186.0 207.4 219.2 227.6

Tg Range (°C) 9.3 15.3 18.0 28.0 26.7 23.3 18.7

Break Elong 111.3 104.2 79.0 44.8 19.3 10.5 10.5 (Z)

Izod Ft- 16.4 14.5 12.0 2.02 1.76 1.64 1.72 lb/in

J/mm 875.4 774.0 640.6 107.8 93.9 87.5 91.8

Flex Mod PSI 319682 330047 339508 354151 376515 395777 402475

MPa 2,205 2,276 2,341 2,442 2,597 2,729 2,776

DTUL (°C) 138.6 148.7 156 172.5 191.7 205.8 217.9

Avg Haze (Z) 2.2 1.63 1.76 1.74 1.64 1.99 3.82

ZCrystallized 12.74 11.82 10.92 0 0 0 0

MaxLoad lb 1576 1614 1696 1704 1693 1600 1108 kg 715 732 769 773 768 726 502

Energy Max Load ft-lb 47.8 48.2 50.1 42.0 33.9 24.3 10.5

Joules 35.3 35.5 36.9 31.0 25.0 17.9 7.7

EnergyTot ft-lb 60.8 62.3 65.6 51.5 36.0 26.1 12.5

Joules 44.8 45.9 48.4 38.0 26.5 19.2 9.2 *Not an example of polymers used according to the invention,

Regarding the solvent tolerance and ESFR of these samples, it is interesting to note that bisphenol-A polycarbonate, as an amorphous polymer, has poor solvent resistance. This is manifested by the tendency of this material to crystallize in aggressive solvents such as toluene. Table 3 shows the results of the DSC analyses of compression molded films of the

5 blends immersed in toluene. The percent crystallinity upon 15 minute toluene exposure is highest for the BA PC. Blending the BHPF coPC into the BA PC inhibits such crystallization, indicating improved solvent tolerance.

The ESFR results in 75/25 iso-octane/ toluene solvent also showed increasing solvent tolerance of polycarbonate by incorporating BHPF into the polymer. The critical stress

10 to failure is more than 50 percent higher in the BHPF coPC than in the BA PC. The experiment was done using a constant strain method. The actual values of critical stresses of BA PC and BHPF coPC were calculated from the flex moduli and the critical strains and were found to be 1598 psi (11.0 MPa) and 2415 psi (16.7 MPa), respectively.

As can be seen, the BHPF coPC is somewhat more brittle than B A PC and tends to

15 reduce the toughness of blends accordingly, but not as much as would be expected based on interpolating the data for the two components separately. Moreover, Blend 7 is particularly noteworthy because it unexpectedly exhibits improved performance in all Dynatup categories compared to the BA PC reference sample and retains very good Izod impact resistance.

A dry blend of 75 weight percent BHPF/BA (60/40) coPC (Mw = 27,000, IV = 0.36

20 dL/g) and 25 weight percent BA PC (melt flow rate = 3.5 g/10 min) was prepared and then melt blended using a Killion single screw extruder operating at 360°C and 10 lb/hour extrusion rate. The resulting blend (obtained as extruded pellets with 42 mole percent BHPF, IV = 0.39 dL/g, Mw = 26,910, and Tg = 210°C) was dried at 125°C for 4 hours. After drying, the blend was injection molded into 4 inch (101.6 mm) x 12 inch (304.8 mm) x 1 /8 inch (3.2 mm) plaques on a

25 300 ton Demag machine at a molding temperature of 352^CC and an injection speed of 1.8 sec. The resulting plaques were aged at 188°C for 1 hour and the impact resistance was measured by instrumented dart impact at 10 mph according to ASTM D3763-86. Samples tested at 23°C had an impact resistance of 370 in-lb. Samplestested at -29^CC had an impact resistance of 345 in-lb. This is a very surprising retention of toughness after a heat aging exposure, a property which is

30 critical for vehicle body panels which are typically exposed to an "aging" step like this in a painting process. It has been very difficult to find injection moldable polymers that can satisfy this requirement.

The general procedure of the above example was used to prepare a dry blend of 30 weight percent BHPF/BA (60/40) coPC (Mw = 27,000) and 70 weight percent BA PC (melt

35 flow rate = 3.5 g/ 10 min) which was melt blended using a Killion single screw extruder operating at 334°C. The resulting blend was obtained as extruded pellets with 15 mole percent BHPF, IV = 0.45 dL/g, Mw = 29,000. After drying at 125°C for 4 hours, the blend was injection molded into 4 inch (101.6 mm) x 12 inch (304.8 mm) x 1 /8 inch (3.2 mm) plaques on a 300 ton Demag machine at a molding temperature of 316°C and an injection speed of 1.4 sec. Instrumented dart impact measurements were conducted on the resulting plaques at test temperatures of 23, 0, and -20°C for both as-molded and aged (1 hour at 160°C) samples. The instrumented dart impact resistance (IR) results are shown in the following table.

Table 4 - 15 Mole % Blend Heat Aging Results

Test Temp. IR (in- -lb), IR (in-lb),

(°C) As -Molded Aged

23 540 456

0 538 473

-20 580 586

The 30/70 blend of BHPF/BA coPC and BA PC prepared in the previous example was fabricated into fender body panels using a 3500 ton Krausse-Maffei injection molding machine equipped with a 1987 Buick T-type fender tool of P-20 steel. The injection molding conditions are shown in the following table.

Injection Molding Conditions for Fenders Using a 3500 Ton Krausse Maffei Machine

Temperatures (°F)

Zone 1 (Feed) 620

Zone 2 625

Zone 3 630

Zone 4 650

Zone 5 650

Zone 6 650

Nozzle Heating Zone 600

Melt Temperature 657

Manifold 535

Mold (set) 190

Mold (actual) 195-205

Pressures (psi)

Clamping Force (tons) 3000

Constant "Maximum" Injection Pressure 2200

Actual Injection Pressure 1842

Constant Hold Pressure 800

Constant Back Pressure 100

Pressure Drop at Decompression 50

Screw

Constant Injection Speed (%) 15

Constant Plasticizing Speed (%) 50

Screw Speed Ratio (%) 30

Times (seconds)

Injection Time 15

Hold Pressure Time 10

Cooling Time 40 Total Cycle Time 87

Positions (inches)

Plasticizing Stroke 9.75

Transfer Point for Hold pressure 1.15 Injection Unit Stroke (Rear Position) 49.2

Hydraulic Ejector Start 35 Ejector Stroke 4

Fenders molded according to this procedure were well-formed and exhibited no splay or discoloration. It was observed that faster injection rates, on the order of 10 seconds, resulted in some splay and discoloration under otherwise similar conditions. As can be seen above, exterior body panels can be injection molded according to the present invention for a range of vehicles including automobiles, trucks, recreational vehicles, and mobile homes, where these combinations of processability, heat resistance, toughness, light weight and recyclability are desired.

Claims

1. An exterior body panel for a vehicle consisting essentially of (I) a carbonate polymer composition consisting essentially of (la) a diaryl fluorene carbonate polymer component and optionally (lb) a second, different carbonate polymer component; the carbonate polymer composition (I) having an inherent viscosity as determined at 25°C in methylene chloride at a polymer concentration of 0.5 g/dL in the range of from 0.30 to 0.47 dL/g and comprising from 10 to 50 mole percent diaryl fluorene moieties based on the total moles of diaryl fluorene and additional multihydric compound remnant moieties in the carbonate polymer composition.

2. An exterior body panel according to Claim 1 wherein the diaryl fluorene moieties in the diaryl fluorene carbonate polymer component are represented by the general formula:

( l)4 (R2.4

(R4)4 (R3.4

wherein Ri, R2, R3, and R4 independently in each occurrence are hydrogen, a C^-C^ linear or cyclic alkyl, alkoxy, aryl or aryloxy radical or a halogen.

3. An exterior body panel according to Claim 2 wherein Ri, R2, R3, and R4 are all hydrogen and the diaryl fluorene is a 9,9-bis (4-hydroxyphenyl) fluorene (BHPF) remnant moiety.

4. An exterior body panel according to Claim 1 wherein the carbonate polymer composition (I) contains from 25 to 45 mole percent diaryl fluorene moieties.

5. An exterior body panel according to Claim 1 wherein the carbonate polymer composition (I) contains from 35 to 40 mole percent diaryl fluorene moieties.

6. An exterior body panel according to Claim 1 wherein the carbonate polymer composition (I) has an inherent viscosity as determined at 25°C in methylene chloride at a polymer concentration of 0.5 g/dL in the range of from 0.35 to 0.42 dL/g.

7. A process for preparing an injection molded, vehicle exterior body panel from a thermoplastic resin characterized in that the thermoplastic resin is (I) a carbonate polymer composition consisting essentially of (la) a diaryl fluorene carbonate polymer component and optionally (lb) a second, different carbonate polymer component; the 96/29365

carbonate polymer composition (I) having an inherent viscosity as determined at 25°C in methylene chloride at a polymer concentration of 0.5 g/dL in the range of from 0.30 to 0.47 dL/g and comprising from 10 to 50 mole percent diaryl fluorene moieties based on the total moles of diaryl fluorene and additional multihydric compound remnant moieties in the carbonate polymer composition.

8. A process according to Claim 7 wherein the diaryl fluorene moieties in the diaryl fluorene carbonate polymer component are represented by the general formula:

(R _>4 (R2.4

(R )4 (R3.4

wherein Ri , R2, R3, and R4 independently in each occurrence are hydrogen, a C.-C,₂ linear or cyclic alkyl, alkoxy, aryl or aryloxy radical or a halogen.

9. A process according to Claim 8 wherein Ri , R2, R3, and R4 are all hydrogen and the diaryl fluorene is a 9,9-bis (4-hydroxyphenyl) fluorene (BHPF) remnant moiety.

10. A process according to Claim 7 wherein the carbonate polymer composition (I) contains from 25 to 45 mole percent diaryl fluorene moieties.

1 1. A process according to Claim 7 wherein the carbonate polymer composition (I) contains from 35 to 40 mole percent diaryl fluorene moieties.

12. A process according to Claim 7 wherein the carbonate polymer composition (I) has an inherent viscosity as determined at 25°C in methylene chloride at a polymer concentration of 0.5 g/dL in the range of from 0.35 to 0.42 dL/g.