MXPA98004581A - Polymer of improved polyester packaging absorbing of radiation infrarr - Google Patents

Abstract

The present invention relates to a polyester polymer composition containing graphite on the scale of about 3-60 parts per million based on polyester, the size of the graphite particles is more than about 0.5æm, however, as an upper limit, any particle size that is not visible to the naked eye is acceptable, said polyester polymers having graphite incorporated therein absorb infrared radiation better than polymers that do not contain graphite, and in this way, in the production of plastic bottles less energy is required to heat the preform so that it can be blow molded creating a bottle

Description

IMPROVED POLYESTER PACKAGING POLYMER FROZEN RADIATION ABSORBER BACKGROUND OF THE INVENTION This application is a continuation in part of USSN 08/893 »005» filed on April 23, 1997.

CAMPQ p? L INVENCI N The present invention relates to packaging polymers »particularly to bottles made from packaging polymer compositions and particularly to polyester polymer compositions having an improved infrared (IR) absorption characteristic. More specifically, the present invention relates to a polyester polymer composition that includes graphite as an infrared radiation absorbing material. The present invention envisions the use of polyester polymer compositions to make plastic bottles with acceptable color and clarity "with suitable physical properties and with improved infrared radiation absorption properties as the main features.

PREVIOUS TECHNIQUE It is well known to use polyester compositions as a packaging material, particularly compositions comprising polyethylene terephthalate generally known as "PET" in the form of films or plastic or other containers. Plastic bottles are used to contain pressurized fluids such as carbonated beverages, soft drinks or mineral waters, as well as non-carbonated and non-pressurized beverages. To form plastic bottles, the polymer is extruded and then shaped into small fragments. The fragments are used to make a bottle preform by injection molding "as is well known in the industry. The preform is then reheated and blown to create a mold that provides the final shape of the bottle. The blow molding step causes the biaxial orientation of the polyester composition to occur at least on the side walls and bottom of the bottles, and to a lesser degree on the neck. The biaxial orientation provides resistance to the bottle so that it can withstand deformation from internal pressure during use and adequately contain the fluid during an industrially standardized countertop life. To summarize »a conventional polyester fragment based on a modified PET resin is generally sent to the manufacturers of plastic bottles which injection molded into the polymer to make a bottle preform. The preform must be heated to approximately 105 ° C and blow molded to form a bottle. It would be particularly useful in the industry to reduce the energy required to heat the preform and cause the preform to quickly achieve the desired blow molding temperature of about 105 ° C. Of course, the blow molding temperature varies for different polyester compositions. For example, polyethylene naphthalate would require a different blow molding temperature. The heating of a conventional polyester sheet at about 105 ° C is typically achieved with commercially available infrared quartz lamps that emit in the near infrared region (NIR), as well as in the infrared (IR) region, as will be explained in more detail. after. The absorption of infrared radiation by PET is low because PET tends to absorb infrared radiation only at certain frequencies, as will be described later. In this way, the rate of heating of the PET is highly dependent on the ability of the polymer resin to absorb the infrared radiation, and any components within the PET composition that can improve the absorption of infrared radiation is commercially useful for the bottle manufacturers. The patents of E.U.A. Nos. 5,409,983 »5,419» 936 and »529» 744 to Tindale and assigned to ICI »describe a polyester composition that includes an infrared absorbing material comprising suitable metals that intrinsically absorb the radiation in the wavelength region from 0.5 microns to 2 microns (NIR and IR) to substantially reduce the reheat time of the polymer or bottle preform. Suitable metals include antimony »tin» copper »silver» gold »arsenic» cadmium »mercury» lead »palladium» platinum or a mixture of two or more of these. For most applications »silver metals» gold »arsenic» cadmium »mercury» lead »palladium and platinum are» or very expensive »or risky for the environment» and these metals are not particularly preferred. The metals that are most desired are one or more of antimony »tin or copper» being particularly advantageous antimony. The patents of E.U.A. Nos. 4 »408» 004 and 4, 535,118 a Pengilly, "incidentally assigned to Goodyear, describes a polyester that has improved infrared radiation absorbing materials contained therein. The only infrared radiation absorber material mentioned is the carbon black "including specific types such as channel black and furnace black. The carbon black has an average particle size of 10 to 500 nanometers and a conspiring of 0.1 to 10 parts by weight per parts per million by weight of the polyester used. This composition also substantially reduces the time to heat the preform to about 105 ° C. European Patent Application No. EPA 739,933 in the name of Shimotsuma et al. And assigned to Teijin Limited "discloses a polyester resin composition containing graphite as a laser-sensitive material, having an average particle size of 0.1 to 50 microns. . This patent does not recognize that graphite is useful for absorbing infrared radiation. This patent is also not related to bottle preforms, packaging materials or plastic bottles. In fact »this patent refers to a printing technique for electrical or electronic parts.

BRIEF DESCRIPTION OF THE INVENTION The present invention "in the broadest sense" includes a polyester resin containing graphite »The size of the graphite particles is such that they are not readily visible to the naked eye when they are uniformly dispersed in the resin, and are present in an amount from 3 to SO parts by weight per parts per million by weight of the polyester resin (ppm). In the broadest sense, the present invention includes a method for heating either a polyester resin or a polyester bottle preform by exposing the polyester resin or polyester bottle preform to infrared radiation for a sufficient time to heat the resin of polyester or polyester bottle preform at a temperature higher than room temperature "where the polyester resin or the polyester bottle preform contains 3-60 ppm graphite particles, the graphite particles are not easily visible to simple seen when they are evenly dispersed there. In the broadest sense, the present invention also comprises a bottle preform that can be heated with IR heaters up to the desired blow molding temperature and blow molded to form a plastic bottle, said bottle preform being made of polyester containing graphite particles, and the size of the graphite particles being small enough so that they are not easily visible to the naked eye when dispersed evenly within the bottle preform. The graphite particles are present in an amount of 3 to 60 ppm. based on the amount of polyester. In the broadest sense. the present invention also comprises a plastic bottle made from polyester containing graphite particles, said graphite particles are small enough not to be easily seen by the naked eye after uniform distribution within the plastic bottle. and they are used in an amount of 3 to 60 ppm »based on the amount of polyester.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a diagram of the PET absorption spectrum in which IR wavelengths are plotted against the absorption coefficient (1 / cm) of the PET. Figure 2 is a bar graph of the percentage of total energy in the blow molding window where the percentage of total energy of the IR lamps is plotted against the control and 5 ppm »7.5 ppm» 10 ppm »15 ppm and 20 ppm. ppm of graphite / polymer compositions. Figure 3 is a bar graph of the blow molding window wherein the temperature of the preform (in ° C) is plotted against the control and 5 ppm. 7.5 ppm. 10 ppm. 15 ppm and 20 ppm of graphite / polymer compositions. Figure 4 is a graph of the percentage of maximum energy to heat a bottle preform at 105 ° C against the amount of graphite in the preform »in ppm.

DESCRIPTION OF THE PREFERRED MODALITIES The infrared radiation covers wavelengths from 0.8 microns to 500 microns, and is generally divided in the near infrared region (NIR 0.8 to 2.5 microns). Average IR (2.5 to 50 microns) and far IR (50 microns - 500 microns). The heating occurs because the infrared radiation penetrates inside the polymer and causes the molecules to vibrate without subjecting the polymer to conduction heating. The polyester. and particularly polyethylene terephthalate (PET) can be heated by infrared radiation generally faster and more uniformly than by conduction heating, but PET absorbs only a small portion of the IR wavelength. As shown in figure 1. which is a graph of the absorption coefficient (1 over centimeter, which is the penetration depth of IR radiation) against IR wavelength (in microns), it is clear that PET absorbs mainly The IR wavelengths around 5.9 and about 8.7 to 9.1. This corresponds to specific bonds in the polyester that are excited by infrared radiation. From figure 1 it is easy to visualize that if the polyethylene terephthalate could be modified to absorb more IR wavelengths. it would require less time to be heated to about 105 ° C in a preform and plastic bottle operation. Of course, it is also necessary that the plastic bottle formed still exhibit adequate clarity. If the particles of the IR radiation absorbing material-in the case of the graphite of the present invention-have a very large size, then the particles scatter the wavelengths of visible light and cause the bottle to appear cloudy and unclear, particularly from an aesthetic point of view. If it is desired to manufacture a translucent plastic bottle that is a brown or green color for certain specific types of soft drinks or alcoholic beverages such as beer, then the size and quantity of the graphite particles is not as important. However, the industry does not want the particles to be visible to the naked eye even in translucent bottles with color. Non-translucent colored bottles that are capable of masking the graphite particles may use a larger graphite size scale "as long as the graphite does not appear on the surface of the bottle. Said bottles can achieve the main objective of using less energy to heat the bottle preform for blow molding. Graphite, which is a crystalline allotropic form of carbon, most commonly exists in the form of plates. For clear bottles »graphite particles should measure more than approximately 0.5 μm (microns) in the largest dimension» and not be easily visible to the naked eye (as an upper limit). A scale that is preferred for the size of the graphite particles is 0.6-8μm. The amount of graphite used can vary from 3 ppm to 60 ppm »based on the weight of the resin. However, when a clear bottle is preferred, having approximately 40 ppm or more of graphite (based on the weight of the resin) produces a bottle from a gray to dark gray smoked color. Although this may be acceptable for bottles with color, which the present invention attempts to cover, the preferred scale of the present invention is between 5 and 20 ppm of graphite, and most preferably between 8 and 12 ppm. If desired, master batches of the polymer composition or raw material thereof can be made which contain amounts of the graphite in much higher concentrations for subsequent mixing with the polymer to achieve the desired levels of graphite in the polymer. Suitable polyesters are produced from the reaction of a diacid or diester component comprising at least 655 molar of terephthalic acid or dialkyl-1-terephthalate preferably at least 7054 molarvery preferably at least 7554 molar, still more preferably at least 9554 molar "and a diol component comprising at least 6554 molar of ethylene glycol. preferably at least 70 mole%, most preferably at least 7554 mole, still more preferably at least 9554 mole. It is also preferred that the diacid component be terephthalic acid and that the diol component be ethylene glycol. The molar percentage for the entire diacid component is equivalent to 10054 molar, and the molar percentage for the entire diol component is equivalent to 10054 molar. When the polyester components are modified by one or more diol components that are not ethylene glycol. suitable diol components of the described polyesters can be selected from 1,4-cyclohexanedimethanol. 1,2-propanediol. 1,3-propanediol »1,4-butanediol» 2 »2-dimethyl-1,3-propanediol. 1,6-hexanediol, 1,2-cyclohexanediol »1,4-cyclohexanediol. 1,2-cyclohexanedimethanol »1,3-cyclohexanedimethanol» Z.8-bis (hydroxymethyl) -trichyclo-C5.2.1.0] -decano. wherein Z represents 3 »4 or 5» and diol is that they contain one or more oxygen atoms in the chain »v.gr .. diethylene glycol» triethylene glycol »dipropylene glycol, tripropylene glycol or mixtures thereof and the like. In general, these diols contain 2 to 18, preferably 2 to 8, carbon atoms. The cycloaliphatic diols can be used in their cis or trans configuration or as mixtures of both forms. The preferred diol modifier component is 1 »4-cyclohe? Anodimethanol or diethylene glycol or a mixture thereof. When the polyester components are modified by one or more acid components other than terephthalic acid, the suitable acid components (aliphatic, alicyclic or aromatic dicarboxylic acids) of the linear polyester can be selected, for example, from isophthalic acid. L-4-cyclohexanedicarboxylic acid »1,3-cyclohexanedicarboxylic acid» succinic acid. glutaric acid »adipic acid. Sebacic acid 1.12-dodecanoic acid. 2,6-naphthalenedicarboxylic acid. bi-enzoic acid, or mixtures thereof and the like. In the preparation of the polymer, it is commonly preferable to use a functional acid derivative thereof such as "dimethyl ester" diethyl or dipropyl dicarboxylic acid. The anhydrides or acid halides of these acids can also be used where practical. The acid modifiers generally delay the rate of crystallization compared to terephthalic acid. Also contemplated by the present invention is a modified polyester made by reacting at least 8554 molar terephthalate from terephthalic acid or dimethyl terephthalate with any of the above comonomers. The molar percentage of all the diacids is 10054 molar "and the molar percentage of all the diols is 10054 molar. In addition to the polyester made from terephthalic acid (or dimethyl terephthalate) and ethylene glycol. or a modified polyester as mentioned above. The present invention also includes the use of 10054 of an aromatic diacid such as 2,6-naphthalenedicarboxylic acid or bibenzoic acid. or its diesters "and a modified polyester made by reacting at least 8554 molar of the dicarboxylate from these aromatic diacids / diesters with any of the above monomers. Conventional production of polyethylene terephthalate is well known in the art and comprises reacting terephthalic acid with ethylene glycol at a temperature of approximately 200 to 250 ° C to form monomer and water. Because the reaction is reversible »water is continuously removed» leading the reaction to monomer production. Subsequently, the monomer is subjected to a polycondensation reaction to form the polymer. During the reaction of the terephthalic acid and ethylene glycol, it is not necessary that a catalyst be present. Generally »during polycondensation reaction »a catalyst such as antimony is preferred. The use of diesters "other diacids and other diols may conventionally employ various catalysts" as is well known in the art. The manner of producing the polyester of the present invention may be any conventional manner that is acceptable for the present invention. In the manufacture of plastic bottle and bottle preforms from preforms, it is commonly desired to produce the cleanest and cleanest possible polymer. Consequently, the fewer additives are used, the clearer the polymer produced will be. On the other hand, "it is sometimes desirable to make a plastic bottle or bottles with color and other desired characteristics" and thus the use of a variety of conventionally known additives is also within the scope of the present invention. Consequently »several pigments can be added to the polymer, dyes. fillers, branching agents, crystallization retarding agents and other typical agents. usually during or near the end of the polycondensation reaction. The desired additives and acts and the place of introduction into the reaction are not part of this invention and this technology is well known in the art. Any conventional system can be employed, and those skilled in the art can choose between different additive introduction systems to achieve the desired result.

The graphite can be introduced into the polyester production process at any time. For example, if a diacid and a glycol are being reacted, the graphite can be introduced during the esterification reaction or during the polycondensation reaction. Since graphite eεtects mainly in a plate-like structure, it is oriented naturally in the direction of injection molding for the bottle preforms and in the direction of blow molding during the production of the plastic bottles. This means that the plates align themselves with the walls of the preform or with the walls of the plastic bottle in such a way that their main surface corresponds to the main surface of the plastic bottle or bottle preform. The advantage of said alignment occurs when the bottle preform is subjected to infrared radiation. The radiation is better absorbed by the graphite, which is oriented so that it "puts its largest surface to the infrared radiation" capturing and absorbing the radiation in this way. The amount of energy needed to reheat the preforms depends on the optimum temperature for stretch and blow molding of the bottle. If the temperature is very low »the bottle will have a pearly appearance» and if the temperature is too high »the bottle will have a cloudy appearance. This difference in temperature is called the window of molding-molding. In commercial operations »the energy of the IR heating lamps is set to heat the preforms to a temperature in the middle of the mold-molding window. Figure 4 shows the energy needed to heat preforms containing graphite, in a Sidel SBO 2/3 production machine. at a temperature of 105 ° C, and illustrates the lower energy requirement by increasing the concentration of graphite.

Test methods The relative viscosity (RV) was determined by mixing 0. 2 grams of the amorphous polymer composition with 20 ml of solvent consisting of dichloroacetic acid at a temperature of 25 ° C and using an Ubbelohde viscometer to determine the viscosity. The turbidity of the amorphous polymer composition was determined by visual observation. The brightness and yellow character of the amorphous polymer composition were determined using a digital color monitor such as a Hunter Lab Sean 6000. Normally, the acceptable brightness scale is 25-35. The smaller the number the more gray the polymer will be. For the yellow character, a negative number indicates more blue character and a positive number indicates more yellow character. Preferably, the yellow character number is between -3 to -8 (not yellow »but not so blue). The analysis of the content of DEG (diethylene glycol) in the amorphous polymer resin was also determined. A suitable portion of the amorphous polymer was hydrolyzed with an aqueous solution of ammonium hydroxide in a sealed reaction vessel at 220 + 5 ° C for approximately two hours. The liquid portion of the hydrolyzed product is then analyzed by gas chromatography. The gas chromatography apparatus was a FID Detector (HP5890, HP7S37A) from Hewlett PacKard. The ammonium hydroxide is 2B to 30% by weight of Fisher Scientific's ammonium hydroxide and is reactive grade. The CEG value (carboxyl end groups) of the amorphous polymer is determined by dissolving a sample of the amorphous polymer in reactive grade benzyl alcohol and titrating the purple end point of the phenol red indicator with a sodium hydroxide / benzyl alcohol solution at 0.03N. The results are reported as milliequivalents of sodium hydroxide per kilogram of the sample. The analysis of acetaldehyde (A / A) in the amorphous polymer in parts per million is determined by obtaining a representative sample of the amorphous polymer by grinding the polymer cryogenically (using liquid nitrogen) so that the amorphous polymer passes through the polymer's sieve. Mesh number ten but meet on a sieve of 25 meshes. A heavy portion is then heated to 160 ° C for 90 min. in a closed system to release acetaldehyde. The acetaldehyde content of the upper space in the closed system is then analyzed by gas chromatography and the parts per million of acetaldehyde are determined therefrom. The gas chromatography apparatus used is the same as that used for the SDR analysis. The determination of the amount of catalysts and of the sequestering agent in the amorphous polymer is determined using a DC plasma emission spectrograph. The spectrograph employed is manufactured by Spectrometric Inc. of Andover MA and is a Spectrospan III high voltage DC plasma emission spectrograph. A sample of the amorphous polymer is placed in a case and the case is introduced into the spectrograph and the baseline and the inclination of each catalyst and sequestering agent present is determined. The catalysts used in the example are antimony (Sb). manganese (Mn). and cobalt (Co). and the sequestering agent is phosphorus (P). The glass transition temperature (Tg) was also determined. the melting temperature (Tm) and the maximum crystallization rate temperature (Te). A Differential Scanning Canorí (DSC) was used to determine the transition temperature of glass, speed of glass crystallization and transition of the melting point. The rate of increase / decrease of temperature is 10 ° C per minute. The DSC used was a 910 DSC model by Perkins Elmer. The DSC was purged with nitrogen at a rate of 50 ml per minute. The percentage of isophthalic acid (IPA) present in the amorphous polymer was determined using a Hewlett Packard liquid chromatograph (HPLC) with an ultraviolet detector at 285 nanometers. A sample of amorphous polymer was hydrolysed in dilute sulfuric acid (10 ml of acid in 1 liter of deionized water) in a steel pump inoperable at 230 ° C for 3 hours. After cooling, an aqueous solution of the pump was mixed with three volumes of methanol (HPLC grade) and a normal aqueous solution. The mixed solution was introduced into the HPLC for analysis.

E E LO The samples of the example were produced in a pilot line reactor of 186 kilos. The polymer was prepared from 199 Kilograms of DMT with 135 kilograms of ethylene glycol and with 82 parts per million of manganese (using manganese acetate). 250 parts per million antimony (using antimony trio). 65 parts per million of cobalt (using cobalt acetate) and 1.4% by weight of diethylenegol (based on the weight of the polymer). Eight lots were prepared in total with O »5» 7.5 »10, 15, 20» and 50 parts by weight of graphite per parts per million by weight of polymer. The maximum temperature of the ester exchange batch was 250 ° C. During the ester exchange reaction, the methanol was removed. At the start of the pol condensation reaction »69.7 parts by weight of phosphorus per part per million by weight of polymer were added in the form of polyphosphoric acid as a sequestering agent to determine the catalytic activity of the ester exchange. Furthermore, 2.5% by weight (based on the weight of the polymer) of isophthalic acid were used, thus forming the copolyether isophthalate of polyethylene terephthalate. The results of this example are set forth in table l.

TABLE 1 Table 1 shows that the different graphite samples (except the 50 ppm sample) have substantially the same characteristics and properties as the control. The 50 ppm sample actually had the best (lowest) level of acetaldehyde, but its brilliance properties were not satisfactory for making transparent bottles. Green or brown plastic bottles with a 50 ppm graphite polymer can be produced. The blow molding windows and the preform reheating properties of the PET and PET control containing 5 »7.5» 10 »15 and 20 ppm of graphite were analyzed in Plástic Technologies» Inc. (The Netherlands »OH). The bottles were blown in a Sidel SBO 2/3 production machine using a single bottle mold for soft carbonated soft drinks of 2 liters. First »the conditions of the blow molding were optimized for a suitable control resin. A "heat scrutiny" was then carried out on the control resin by decreasing and raising the total energy percentage of the quartz furnace lamps in 2% increments. Ten bottles were blown in each percentage of total energy and one of the middle bottles was observed to verify the amount of perch or turbidity. The temperature of the performa in the exit of the furnace of the SBO machine was registered using an infrared pyrometer that reads the surface temperature of the performa (the variability of the infrared pyrometer is of approximately 1 ° C). The resin blow molding window was defined as the temperature scale of the preforms that produced a slightly pearly to slightly cloudy bottle. Using the optimized blow molding conditions of the control polymer, heat queries were then carried out on the other resins. The control and graphite polymer samples of 5 ppm »7.5 ppm. 10 ppm »15 ppm and 20 ppm were injection molded to create bottle preforms and blown to create plastic bottles. Figure 2 shows the percentage of total energy used by the infrared lamps needed to heat the samples »namely: the control that had no graphite and the graphite samples of 5 ppm» 7.5 ppm »10 ppm» 15 ppm and 20 ppm. This figure clearly shows that less energy is used by the IR lamps (in the Sidel SBO 2/3 machine) to heat the polymer to a temperature that can be blow molded to create an acceptable plastic bottle (approximately 105 ° C) when graphite is used. Figure 3 shows the blow molding window for the bottle perforations (set forth in figure 2) against the performation temperature (in ° C). The blow molding window eß the temperature scale in which the preform can be blow molded to create a plastic bottle. If the temperature is very cold (generally below about 100 ° C) the blow molding will cause a cold stretching of the polymer »creating a whitish color in the bottle called aperol. Obviously »stretching at a very cold temperature is not desired, since it affects the physical properties. the ability of the bottle to adequately conform to the shape of the mold when it is blown, and the overall appearance of the bottle. On the other hand, if the temperature is very hot the bottle develops turbidity and is no longer transparent. For bottles with color that are not transparent, for example, a slight turbidity can be masked by the pigment. In this way, it is apparent that a product and a process that completely satisfy the objects »purposes and advantages set forth above have been provided» according to the invention ». Although the invention has been described along with specific embodiments thereof it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art in light of the above description. Consequently, it is tried to cover all those alternatives, modifications and variations that fall within the spirit and wide scope of the aforementioned indications.

Claims (7)

NOVELTY OF THE INVENTION CLAIMS

1. - A polyester composition useful for absorbing IR radiation comprising: a polyester containing about 3-60 parts by weight of graphite particles per parts per million by weight of said polyester »further characterized in that said graphite particles are not easily visible to simple view when they are uniformly dispersed in said polymer.

2. The polyester composition according to claim 1 »further characterized in that said graphite particles measure more than 0.5 μm in the largest dimension.

3. The polyester composition according to claim 1. further characterized in that said polyester contains at least B5 mol% of terephthalate.

4. The polyester composition according to claim 1 »further characterized in that said polyester contains at least 85 mol% of naphthalate.

5. A polyester bottle preform for manufacturing plastic bottles, further characterized in that said bottle preform absorbs IR radiation »said preform is made from a polyester containing approximately 3-60 parts by weight of graphite particles in parts per million by weight of said polyester »further characterized in that said graphite particles are not easily visible to the naked eye when they are evenly dispersed in said preform.

6. The polyester bottle preform according to claim 5 »further characterized in that said graphite particles measure more than about 0.5 μm in the largest dimension.

7. The polyester bottle preform according to claim 5 »further characterized in that said polyester contains at least 85 mol% terephthalate. B. The polyester bottle preform according to claim 5 »further characterized in that said polyester contains at least 85 mol% of naphthalate. 9. A plastic bottle capable of absorbing IR radiation, said bottle is made from a polyester and approximately 3-60 parts by weight of graphite particles per parts per million by weight of said polyester, further characterized in that said particles Graphite are not easily visible to the naked eye. 10. The plastic bottle according to claim 9 »further characterized in that said polyester contains at least 85 mol% of terephthalate. 11. The plastic bottle according to claim 9 »further characterized in that said graphite particles measure more than about 0.5 μm in the largest dimension. 12. The plastic bottle according to claim 9. further characterized in that said polyester polymer contains at least 85 mol% of naphthalate. 13. A method of blowing a bottle preform to create a plastic bottle. Said method comprises: heating said bottle performa using IR radiation at a temperature sufficient to be blow molded and create an acceptable plastic bottle that does not have aperlamiento or crystallization induced by heat; and blowing said preform to create said plastic bottle "further characterized in that said bottle preform comprises a polymer and approximately 3-60 parts by weight of graphite particles per parts per million by weight of said polymer, said polymer contains at least about 80% by weight of polyester polymer; and wherein said graphite particles are not easily visible to the naked eye. 14. The method according to claim 13, further characterized in that said graphite particles measure more than 0.5 μm in the largest dimension. 15. The method according to claim 13, further characterized in that said polyester contains at least 85 mol% terephthalate. 16. The method according to the claim 13, further characterized in that said polyester contains at least 85% molar of naphthalate. 17. A method for heating a polyester bottle preform and putting said polyester bottle preform to infrared radiation for a sufficient time to heat said preform to more than the ambient temperature "said polyester preform contains approx. 3-60 parts by weight of graphite particles per parts per million by weight of polyester. further characterized in that said graphite particles are not easily visible to the naked eye.