RU2386645C2 - Spheroidal particles of polyester polymers - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: invention relates to spheroidal particles of polyester polymer and products made from the said particles. The particles are characterised by inherent viscosity It.V of at least 0.72 dl/g and/or at least two pressure peaks, and/or low degree of crystallinity in an interval of at least 20% and maximum degree of crystallinity T_cmax, and optionally but preferably contain 10 parts/million or less residual acetaldehyde. The spheroidal particles are dried, molten and objects are moulded from the molten mass.

EFFECT: provision for minimal degree of aggregation of particles in the drier.

43 cl, 5 dwg, 5 tbl, 2 ex

Description

Link to related applications

This application has priority over provisional application US No. 60/606727 of September 2, 2004 and provisional US application No. 60/618951 of October 15, 2004, incorporated herein by reference in its entirety.

1. Field of invention

The scope of the invention relates to particles of polyester polymers with particular morphology and geometry.

2. The prior art of the invention

Conventional granules and tablets of polyester polymers are usually cylindrical; they are obtained by solid state polymerization, and they are characterized by a high degree of crystallinity. As a result, conventional tablets generally do not stick together in dryers, from which they enter the injection molding machine or the extruder. Although some sticking occurs at drying temperatures (150-185 ° C), it usually does not lead to agglomeration that completely blocks the flow of particles from the dryer.

The authors found that the best option is particles of a polyester polymer with a special morphology, which is not necessary to obtain solid-state polymerization. This morphology has one or more of the following features: low melting point, low crystallinity and high intrinsic viscosity (It.V.), due to the fact that the particles are obtained by non-solid phase polymerization. The authors found that these solid particles, which have a traditional shape, can in some cases stick together strongly in the dryer, so that mechanical separation is required to separate them. According to the observations of the authors, although cylindrical hard tablets move freely in the hopper of the dryers, in some cases, non-hardened cylindrical tablets with a special morphology stick together inside the dryers.

The present study could lead to the conclusion that the free flow of the tablets is due to their morphology, and not their geometry. The authors' studies were continued in order to find out the reason for the adhesion of these tablets. It was desirable to obtain particles of polyester polymers having one or more of these characteristics with a minimum degree of adhesion in the dryer.

3. The invention

The authors were surprised to find that, unlike traditional solid high-crystalline tablets, when using polyester particles with a special morphology, the particle geometry plays a significant role in reducing the adhesion of particles in the dryer. Particles of the present invention have a spheroidal geometry. Thus, for an array of spheroidal particles of a polyester polymer, we have:

A) an average It.V. of at least 0.72 dl / g,

and

B) melting points characterized by:

(i) at least two melting peaks, wherein one of the two melting peaks on the DSC curve for the first heating is in the range of 140-220 ° C and has an endothermic melting peak area equal in absolute value to at least 1 J / g, or

(ii) one or more melting points for which the DSC curve for the first heating deviates from the base curve in the endothermic direction at a temperature less than or equal to 200 ° C, or

C) a low degree of crystallinity in the range of at least 20% and a maximum degree of crystallinity T _cmax defined by the equation:

T _cmax = 50% -CA-OH,

where CA is the total molar percentage of all carboxylic acid residues other than terephthalic acid residues, based on 100 mol% of carboxylic acid residues in the polyester polymer, and OH is the total molar percentage of residues of compounds with hydroxyl functional groups other than ethylene glycol residues , based on 100 mol.% residues of compounds with hydroxyl functional groups; or by both points B) and C); and optionally, but preferably

D) 10 ppm or less of residual acetaldehyde.

A method for preparing spheroids is also provided.

A method for drying and processing spheroids by melting by:

A) drying the spheroids of the polyester polymers in the drying zone to obtain dried spheroids;

B) introducing dried spheroids into the melting zone;

C) melting the spheroids of the polyester polymers in the fusion treatment zone; and

D) molding a molten polymer product,

moreover, the spheroids of the polyester polymers introduced into the drying zone are not obtained by solid phase polymerization and are not necessarily characterized by one or more of the above parameters.

In this embodiment, the spheroids also preferably fall within the above crystallinity range.

Bottle blanks and bottles are also available that are blow molded and drawn from the above spheroids or made in accordance with one of the process options described above.

4. Brief Description of the Drawings

Figure 1 illustrates the geometry and dimensions in inches used in the experiments of the loading hopper of the dryer.

Figure 2 illustrates a device for determining the angle of natural shedding of granular materials through the valve.

Figure 3 depicts a device for determining the angle of natural shedding of granular materials in the mass.

Figure 4 shows a comparison of the angle of natural shedding through the shutter for five materials.

Figure 5 shows a comparison of the angle of natural shedding in the mass for five materials.

5. Detailed description of the invention

The present invention is easier to understand after reading the following detailed description. It should be noted that this invention is not limited to the specific methods and conditions described, because the specific methods and / or conditions of the method for processing plastic products as such may naturally vary.

It should also be noted that in the technical conditions and in the claims, the singular form includes the plural meaning. For example, a reference to processing a thermoplastic “preform”, “product”, “container” or “bottle” includes processing a plurality of thermoplastic preforms, products, containers or bottles. A reference to polymer processing at a set temperature or with a heating element includes, if desired, other temperatures or additional heating elements, except for one indicated at different times during processing, unless otherwise indicated. References to formulations containing a “single” ingredient or “single” polymer include, but are not limited to, other ingredients or other polymers, respectively.

Intervals can be expressed here as “within” or “between,” or from one value to another. In each case, the endpoints are included in the interval. Intervals defined as being greater or less than a certain value exclude endpoints.

The words “comprising” or “comprising” or “having” mean that at least the compound, element, particle or process step, etc. must be present in the composition or product, or method, but this does not exclude the presence of other compounds, substances, spheroids, process steps, etc., even if other such compounds, substances, process, etc. have the same effect as indicated.

Regardless of the context, the expression for temperature means that the temperature associated with the polymer, unless otherwise indicated, is the "real" temperature of the polymer or melting point.

It should be understood that the mention of one or more of the method does not interfere with the implementation of additional stages of the method or the inclusion of the stages of the method between already established stages.

The values of the intrinsic viscosity in this description are given in dl / g and are calculated from the intrinsic viscosity measured at 25 ° C in a solution of phenol / tetrachloroethane 60/40 wt./mass. The intrinsic viscosity is calculated from the measured viscosity of the solution. The following equations describe solution viscosity measurements and subsequent calculations of Ih.V. and the transition from Ih.V. to It.V .:

η _inh = [ln (t _s / t ₀ )] / C,

where η _inh is the characteristic viscosity at 25 ° C at a polymer concentration of 0.50 g / 100 ml of a solution with 60% phenol and 40% 1,1,2,2-tetrachloroethane;

ln is the natural logarithm;

t _s is the time of expiration of the sample through the capillary;

t ₀ - the time of expiration of the solvent through the capillary;

C is the polymer concentration in grams per 100 ml of solvent (0.50%).

Intrinsic viscosity is the limit value for the specific viscosity of the polymer at infinite dilution. It is determined by the following equation:

where η _int is the intrinsic viscosity;

η _r is the relative viscosity equal to t _s / t _0;

η _sp is the specific viscosity equal to η _r -1.

Calibration of the device includes testing a standard standard and then calculating the “accepted” values of Ih.V. using the appropriate mathematical equations.

Calibration Factor = Accepted Ih.V. reference substance / re-determination average

Corrected Ih.V. = Estimated Ih.V. × calibration factor

The intrinsic viscosity (It.V. or η _int ) can be determined using the Billmeier equation:

η _int = 0.5 [e ^{0.5 × corrected In.V.} -1] + (0.75 × corrected Ih.V.).

In one embodiment, the proposed volume of spheroidal polyester polymers with characteristics:

A) secondary It.V. at least 0.72 dl / g and either

B) melting points characterized by:

(i) at least two melting peaks, one of these two melting peaks being on the DSC curve in the range of 140-220 ° C when scanning the first heating and the absolute value of the area of the endothermic melting peak is at least 1 J / g, or

(ii) one or more melting points for which, on a DSC curve, when scanning for the first heating, the heating curve deviates from the base curve in the endothermic direction at a temperature less than or equal to 200 ° C, or

C) a low degree of crystallinity in the range of at least 20% and a maximum degree of crystallinity T _cmax defined by the equation

T _cmax = 50% -CA-OH,

where CA is the total molar percentage of all carboxylic acid residues other than terephthalic acid residues, based on 100 mol% of carboxylic acid residues in the polyester polymer, and OH is the total molar percentage of residues of compounds with hydroxyl functional groups other than ethylene glycol residues , based on 100 mol.% residues of compounds with hydroxyl functional groups; or

with both points B) and C).

The polyester polymer composition is in an isolated form because it is given some degree of crystallinity, in contrast to polyester compositions obtained by melt or melting in an extruder, since crystallinity disappears upon melting.

The particles of the polyester polymer are spheroidal in shape. A spheroid is a particle that has a spherical or nearly spherical shape or the shape of a globule. It is mainly, but not perfect, spherical, and can be distinguished from scales, cylinders, tablets, cones, rods or angular particles of irregular shape. Spheroids have a number of characteristics. For example, spheroids will not line up along a long axis passing through their centers, and will preferably, but not necessarily, have a y / x ratio of equal to or less than 2, where y is the long axis and x is the short axis. In addition, if you place 10.0 g of tablets on one edge of a smooth horizontal steel plate with a layer in the thickness of one tablet and then gently and gradually raise this edge of the plate and tilt it, then the spheroids roll off the plate, so that at an angle of 13 degrees from the horizontal no more than 0.5 g of tablets will remain on it. Spheroids can be spherical, elliptical, oval and contain tails.

In one embodiment, spheroids have a peak roundness distribution of less than 1.4, or less than 1.3, or less than 1.2. Roundness is defined as the perimeter / (4n × surface) “Perimeter”, and “surface” is defined in the cross section of the spheroid.

Spherical particles can be made by cutting a molten polymer flowing through a punch in a water tank under a layer of water, using cutters as the melt flow is pushed through the holes in the punch. When cutting under a layer of water, spheroids are usually not perfectly spherical and usually have a small tail at the points of cutting and separation from the punch plate in a stream of water or other suitable liquid.

Preferably, the spheroids have a number average weight of at least 0.10 g per 100 spheroids, more preferably more than 1.0 g per 100 spheroids, and up to about 100 g per 100 spheroids. The volume of spheroids is not particularly limited, but in one embodiment, an array of spheroids with a volume of at least 1 cm ³ , or at least 3 cm ³ , or at least 5 cm ^{3 is} provided.

The "array" of spheroids of the polyester polymer is at least 10 isolated spheroids, preferably in the range of weights and volumes indicated above. An array of polyester spheroids has characteristics referred to here as averages for randomly selecting 10 or more spheroids in an array. As with any production method, it is possible to obtain abnormal spheroids with characteristics that fall inside or go beyond the specified intervals. However, the spheroids of the present invention possess the claimed characteristics in the entire array, and these characteristics can be obtained by randomly selecting at least ten spheroids and determining these characteristics on average in ten spheroids. All ten spheroids can be studied together in one analysis, or each spheroid can be analyzed separately.

An array of spheroids of polyester polymers is preferably packaged in a container. Examples of suitable containers for spheroids are storage bins before being transported from one point to another. Another example of a container is a dryer hopper connected to an extruder or injection molding apparatus. Another example of a spheroid container is a shipping container, for example a Gaylord box, a trellis box, a railroad car, a trailer that can be attached to a truck, a drum, a steamship cargo, or any other container for transporting spheroids. Thus, containers are proposed for spheroids, ready for transport to the consumer and for turning the tablets into a product. Spheroids were released by the manufacturer after all the necessary treatments to produce particles with characteristics acceptable to consumers who turn tablets into products. In an embodiment where the tablets may be in the dryer hopper, the tablet recipient places an array of tablets in the dryer hopper and removes residual moisture from the tablets to prevent unnecessary IV changes during the fusion process.

In all of these options, spheroids in containers have at least the following characteristics:

A) average It.V. at least 0.72 dl / g, and either

B) melting points characterized by:

(i) at least two melting peaks, wherein one of the two melting peaks on the DSC curve during the first heating scan is in the range of 140-220 ° C and the absolute value of the area of the endothermic melting peak is at least 1 J / g, or

(ii) one or more melting points for which the first heating scan on the DSC curve is characterized by a heating curve deviating from the base curve in the endothermic direction at a temperature less than or equal to 200 ° C, or

C) a low degree of crystallinity in the range of at least 20% and a maximum degree of crystallinity T _cmax defined by the equation

T _cmax = 50% -CA-OH,

where CA is the total molar percentage of all carboxylic acid residues other than terephthalic acid residues, based on 100 mol% of carboxylic acid residues in the polyester polymer and OH is the total molar percentage of residues of compounds with hydroxyl functional groups other than ethylene glycol residues, per 100 mol.% residues of compounds with hydroxyl functional groups; or

both points B) and C) and preferably

D) 10 ppm or less of residual acetaldehyde.

In a preferred embodiment, an array of spheroids was not prepared by solid phase polymerization, and in a more preferred embodiment, an array of spheroids is provided in a container, most preferably in a shipping container.

The spheroids of the polyester polymer are solid at 25 ° C and 1 atm. Spheroids of polyesters are quite resistant to melting and suitable for the manufacture of vessels such as bottles and utensils. The value of It.V. polyester spheroids is at least 0.72 dl / g. For example, It.V. polyester spheroids may be at least 0.75 dl / g, or at least 0.78 dl / g, or at least 0.81 dl / g and up to about 1.2 dl / g or 1.1 dl / g. In a related embodiment, the spheroids of the polyester polymers described above have It.V. at least 0.75 dl / g.

Preferably, the polyester polymer of the present invention contains repeating units of alkylene terephthalate or alkylene naphthalate in the polymer chain. More preferred are polyester polymers that include:

a) a carboxylate component containing at least 80 mol% of terephthalic acid residues, terephthalic acid derivatives, naphthalene-2,6-dicarboxylic acid, naphthalene-2,6-dicarboxylic acid derivatives or mixtures thereof, and

(b) a hydroxyl-containing component, which includes at least 80 mol.% residues of ethylene glycol or propanediol,

based on 100 mol.% residues of the carboxylate component and 100 mol.% residues of the hydroxyl-containing component in the polyester polymer.

Typically, polyethers such as polyethylene terephthalate are prepared by reacting a diol, for example ethylene glycol, with a dicarboxylic acid as a free acid or a C ₁ -C ₄ dialkyl ester to form monomeric esters and / or oligomers, which then undergo a polycondensation reaction to form a polyester. Moreover, more than one compound containing carboxyl groups or a derivative thereof may participate in the reaction. All compounds that react and contain carboxylic acids or their derivatives, which become part of the specified polyester product, are a "carboxylate component". The molar percentage of all compounds containing carboxyl groups or their derivatives approaches 100. The term "residues" of compounds containing carboxyl groups or their derivatives that are included in the specified polyester, refer to that part of these compounds that remain in the specified polyester after these compounds have entered into a condensation reaction with hydroxyl-containing compounds, followed by polycondensation and the formation of chains of a polyester polymer of different lengths.

Several compounds containing hydroxyl groups may become part of the resulting polyester polymer. All compounds involved in the process and containing hydroxyl groups, or their derivatives, which become part of the specified polyester, include a hydroxyl-containing component. The molar percentage of all compounds containing hydroxyl groups or their derivatives, which become part of the specified product, approaches 100. The residues of compounds with hydroxyl functional groups or their derivatives, which become part of the specified polyester, are called the part of these compounds remaining in the specified polyester after that how these compounds reacted condensation with compounds containing carboxyl groups, or with their derivatives, followed by polycondensation and m chains of polyester polymer of different lengths.

The molar percentage of hydroxyl residues and carboxylate residues in the product can be determined by proton NMR.

In a preferred embodiment, the polyester polymer includes:

(a) a carboxylate component containing at least 90 mol%, or at least 92 mol%, or at least 96 mol% of terephthalic acid derivatives of terephthalic acid derivatives of naphthalene-2,6-dicarboxylic acid derivatives naphthalene-2,6-dicarboxylic acid or mixtures thereof and

(b) a hydroxyl-containing component, which includes at least 90 mol.%, or at least 92 mol.%, or at least 96 mol.% of ethylene glycol residues

based on 100 mol.% residues of the carboxylate component and 100 mol.% residues of the hydroxyl-containing component in the polyester polymer.

The reaction of the carboxylate component with the hydroxyl-containing component in the process of obtaining the polyester polymer is not limited to the indicated molar percent, because if desired, you can use a large excess of hydroxyl-containing component, for example, of the order of up to 200 mol.% relative to 100 mol.% used carboxylate component. The resulting polyester polymer will, however, contain the stated amounts of aromatic dicarboxylic acid residues and ethylene glycol residues.

Derivatives of terephthalic acid and naphthalenedicarboxylic acid include C ₁ -C ₄ dialkyl terephthalates and C ₁ -C ₄ dialkyl naphthalates, for example dimethyl terephthalate and 2,6-dimethyl naphthalate.

In addition to the dicarboxylate component - terephthalic acid, derivatives of terephthalic acid, naphthalene-2,6-dicarboxylic acid, derivatives of naphthalene-2,6-dicarboxylic acid or mixtures thereof, the carboxylate components of this polyester may include one or more carboxylic acid compounds with an additional modifier. Such carboxylic acid compounds with an additional modifier include monocarboxylic acid compounds, dicarboxylic acid compounds and compounds with a large number of carboxyl groups. Examples include aromatic dicarboxylic acids, preferably with 8-14 carbon atoms, aliphatic dicarboxylic acids, preferably with 4-12 carbon atoms, or cycloaliphatic dicarboxylic acids, preferably with 8-12 carbon atoms. More specific examples of dicarboxylic acids with a modifier used as the acid component include phthalic acid, isophthalic acid, naphthalene-2,6-dicarboxylic acid, cyclohexane-1,4-dicarboxylic acid, cyclohexanediacetic acid, diphenyl-4,4′-dicarboxylic acid, succinic acid, glutaric acid, adipic acid, azelaic acid, sebacic acid and the like, with isophthalic acid, naphthalene-2,6-dicarboxylic acid and cyclohexanedicarboxylic acid being most preferred. It should be borne in mind that the term “carboxylic acid” includes the use of the corresponding acid anhydrides, esters and acid chlorides of these acids. It is also possible to modify the polyester with tricarboxylic compounds and compounds with a large number of carboxyl groups.

In addition to the hydroxyl-containing component, which is ethylene glycol, the hydroxyl-containing component of the present polyester may include additional modified monohydric alcohols, diols or compounds with a large number of hydroxyl groups. Examples of modified hydroxyl compounds include cycloaliphatic diols with preferably 6-20 carbon atoms and / or aliphatic diols with preferably 3-20 carbon atoms. More specific examples of such diols include diethylene glycol; triethylene glycol; 1,4-cyclohexanedimethanol; propane-1,3-diol; butane-1,4-diol; pentane-1,5-diol; hexane-1,6-diol; 3-methylpentanediol- (2,4); 2-methylpentanediol- (1,4); 2,2,4-trimethylpentanediol- (1,3); 2,5-ethylhexanediol- (1,3); 2,2-diethylpropanediol- (1,3); hexanediol- (1,3); 1,4-di- (hydroxyethoxy) benzene; 2,2-bis- (4-hydroxycyclohexyl) propane; 2,4-dihydroxy-1,1,3,3-tetramethylcyclobutane; 2,2-bis- (4-hydroxyethoxyphenyl) propane and 2,2-bis- (3-hydroxypropoxyphenyl) propane.

As modifiers, the polyester polymer may preferably contain comonomers such as isophthalic acid, naphthalenedicarboxylic acid, cyclohexane dimethanol and diethylene glycol.

Polyester tablets may include mixtures of polyalkylene terephthalates and / or polyalkylene naphthalates along with other thermoplastic polymers such as polycarbonates (PC) and polyamides. Preferably, the polyester comprises predominantly polyester polymers, more preferably in an amount of at least 80 wt.% Or at least 95 wt.% And most preferably 100 wt.% Based on the weight of thermoplastic polymers (excluding fillers, inorganic compounds or spheroids, fibers, shockproof modifiers or other polymers that can form a continuous phase). It is also preferred that the polyester polymers do not contain any fillers, fibers, or shockproof modifiers or other polymers capable of forming a continuous phase.

Polyester compositions can be prepared using polymerization reactions known to those skilled in the art that facilitate esterification and polycondensation. Methods of production using the molten polyester phase include direct condensation of the dicarboxylic acid with a diol, optionally in the presence of esterification catalysts, in an esterification zone followed by polycondensation in the regions where the resulting polymer is present and in the last zone in the presence of a polycondensation catalyst, or exchange of the ester usually in the presence of a transesterification catalyst in ester exchange zone followed by prepolymerization and completion of the process in the presence of catalysis ora condensation.

In the case where the polyester polymer is prepared by melt polymerization, it is solidified to form spheroids. The method of curing the polyester polymer from the melt phase is not limited to stringent requirements. For example, the molten polyester polymer from the melt phase can be passed through a punch or simply a cutter, or through a punch followed by cutting. A gear pump can be used as a driving force for moving the molten polyester through the punch. Instead, the molten polyester polymer can be fed into a single or double screw extruder and extruded through a die optionally at a temperature of 190 ° C. or higher in an extruder nozzle. After the punch, the polyester polymer is cut on an extrusion head under a layer of liquid. The melt of the polyester polymer before cutting is optionally filtered to remove particles larger than the specified size. You can use any other methods traditionally used in the manufacture of spheroids.

To obtain semi-crystalline spheroids, the polyester polymer of the present invention is subjected to partial crystallization. The method and apparatus for crystallization of the polyester polymer are not specified and include thermal crystallization in the gas or liquid phase. Crystallization can be carried out in a vessel with mechanical stirring; in a fluidized bed; in a layer with stirring by the movement of a liquid; in a vessel or tube without stirring; in a liquid medium at a temperature above the glass transition temperature T _{g of the} polyester polymer, preferably at 140-190 ° C., or by any other methods known to those skilled in the art. Also, the polymer can be fed into the crystallizer at a polymer temperature below its T _g (from a glassy state), or it can enter the crystallizer at a polymer temperature above its T _g . For example, a molten polymer from a melt polymerization reactor can be fed through a punch plate and a cutter under a layer of water and then immediately fed to a thermal crystallization reactor under a layer of water, where the polymer crystallizes under a layer of water. Alternatively, the molten polymer can be cut, allowed to cool to a temperature below its T _g , and then fed to a thermal crystallization apparatus under a layer of water or any other suitable crystallization apparatus. Or, the molten polymer can be cut in any conventional way, allowed to cool to a temperature below its T _g , aged and then crystallized. Optionally crystallized polyester spheroids can be stored in solid form by known methods.

Crystallization and heating are effective means to give the polyester polymer the desired degree of crystallinity and melting point. In one embodiment, the polyester polymer particles have at least two melting peaks on the DSC curve of the first heating scan, one of these two melting peaks being a low temperature melting peak in the range of 140-220 ° C. and the absolute value of the area of the endothermic melting peak is at least 1 J / g This melting point means the temperature of the endothermic peak of the DSC, at which the temperature of the sample weighing about 10 mg rises at a rate of 20 ° C / min. There is no need for DSC analysis for all particles except when these particles have a given morphology. These tests reveal the properties of the polymer and help determine whether the polymer has the stated characteristics.

In the case where the particles of the polyester polymer exhibit at least two melting peaks, the low-temperature melting peak is considered as T _m1a (explained below), which is taken as the melting peak if the absolute value of the area under the DSC heating curve during the first scan is at least 1 J / g If the area under the curve is less than 1 J / g, then the uncertainty in the question of whether the curve is really a peak or not becomes too large. Moreover, it can be seen that there are at least two peaks, and the endothermic peaks on the DSC curve are characterized by at least four slopes, among which the first deviates from the baseline, the second slope has an opposite sign compared to the first and the third slope is opposite in sign to the second , and the fourth slope is opposite in sign to the third. The temperature localization of the peaks on each curve determines the melting points on the heating curve. For the purposes of computer calculation of the area of the endothermic melting peaks, it is assumed that the interface between the two peaks is at the point where the curve most closely approaches the baseline.

In this embodiment, when two or more peaks are observed in the DSC heating curve during the first scan, the first peak corresponds to the melting point T _{m1a of the} low temperature peak and the second peak to the melting point T _{m1a of the} high temperature peak, so that T _m1a <T _m1b . The melting point of the low temperature peak of the polymer particles is in the range 130-220 ° C. Preferably, the melting point of the low temperature peak of the polyester polymer corresponds to a peak temperature of at least 140 ° C, or at least 150 ° C, or at least 160 ° C, or at least 170 ° C, and does not exceed 210 ° C, or 200 ° C, or 195 ° C.

In some cases, especially when crystallinity is low due to crystallization at relatively low temperatures and / or short times, crystal rearrangement during the first heating scan in a DSC instrument at a rate of 20 ° C / min can occur so quickly that the melting point in the low-temperature region does not manages to detect. Then, the melting point in the low-temperature region can be seen with an increase in the heating rate in the DSC instrument and with the use of smaller mass samples. If the sample gives a melting peak in the low temperature region, it will be noticeable at higher scan rates. Scan speeds of up to 500 ° C / min can be used. For solid samples processed at relatively high temperatures for a relatively long time and characterized by only one melting peak at a scanning speed of 20 ° C / min, the appearance of a melting point in the low-temperature region is not expected even at higher scanning speeds.

In some cases, depending on the thermal history of the polyester resin tablets, the DSC heating curve obtained during the first scan may have an endothermic shoulder on the low-temperature branch of the main endothermic melting peak instead of two separate and distinct melting peaks. A low-temperature endothermic arm of this type is determined using a curve obtained by taking the first derivative with respect to temperature from the initial DSC curve. The shoulder appears as a peak in the derivative curve. With increasing temperature, the derivative curve deviates from the baseline (at temperature A) in the endothermic direction at a temperature preferably below or equal to 200 ° C, below or equal to 190 ° C or below or equal to 180 ° C, reaching a maximum deviation from the baseline, and then changes direction and approaches or returns to the baseline, but does not cross it. At even higher temperatures, the derivative curve changes direction (at temperature B) and bends again towards the endothermic direction, marking the beginning of the first melting peak in the initial DSC curve. The heat of fusion represented by the shoulder corresponds to the area under the initial DSC curve between temperatures A and B and should be greater than or equal in absolute value to 1 J / g, which should be considered as a true shoulder. Experts know that the small noise of the device in the initial DSC curve can manifest itself as bursts with high amplitude and short duration on the derivative curve. Such noise can be filtered out only by discarding all the details on the derivative curve of less than 5 ° C.

In the case when the melting points are extremely high, for example, of the order of 230 ° C. or higher, efficient drying of the polyester polymer particles at temperatures in the range of 140-190 ° C., as previously thought, is not required. A polymer particle is now proposed that is simultaneously crystalline and has a lower melting point, which allows you to flexibly reduce the melting temperature by 1 ° C or more, or by about 3 ° C or more, and thereby lower the concentration of acetaldehyde without the need to lower temperature in the dryer hopper, from which particles are fed into the melting zone. Even if it is possible to dry particles with a melting point of 230 ° C or higher at a higher temperature of the order of 200 ° C or higher, practically the limit of the drying temperature is in any case a temperature of about 190 ° C, because at temperatures above 190 ° C, particles begin to decolorize in air. In addition, it is desirable to use tablets that flexibly reduce the desired peak temperature for the heating elements. Either during these actions, or for both reasons, the amount of acetaldehyde formed in the melting zone will decrease and the cooling time of the pressed product will also decrease.

In another embodiment, the polymer particles may have one or more melting points, which during the first scan are characterized by a DSC heating curve deviating from the baseline in the endothermic direction at a temperature below or equal to 200 ° C, below or equal to 190 ° C, or lower or equal to 180 ° FROM. In this embodiment, there can be only one melting point on the DSC heating curve, or there can be two melting points. In any case, the history of the heating of particles is such that they exhibit at least one melting point and the first scan gives a DSC heating curve that begins to deviate from the baseline at a temperature below or equal to 200 ° C. In this embodiment, the area of the endothermic peak, which is the deviation of the melting peak from the baseline at a temperature below or equal to 200 ° C, has an absolute value of at least 1 J / g

In all embodiments, the endothermic peak area may have an absolute value of at least 1.5 J / g or an absolute value of at least 2 J / g.

In a preferred embodiment, the conditions in the mold are set so as to obtain polymer particles with a degree of crystallinity in the range of at least 20% and with a maximum degree of crystallinity T _cmax defined by the equation

T _cmax = 50% -CA-OH,

where CA represents the total molar percentage of all carboxylic acid residues other than terephthalic acid residues, based on 100 mol% of carboxylic acid residues, and OH represents the total molar percentage of residues of compounds with hydroxyl functional groups other than ethylene glycol residues, calculated per 100 mol.% residues of compounds with hydroxyl functional groups. The degree of crystallinity of the polyester composition is less than that of traditional industrial tablets, which usually exceeds 55% and sometimes even more than 60%. When the degree of crystallinity is less than 20%, the tendency of particles to adhere to each other and to the walls of the drying equipment increases sharply. By maintaining the degree of crystallinity within the above ranges in combination with other features of the invention, it is possible to reduce the energy consumption in the melting zone, for example, the amperage current supplying the screw motor or the power of the heating elements.

In a preferred embodiment, in which the polyester polymer crystallizes to the extent indicated in the formula, a polymer containing only residues of terephthalic acid and ethylene glycol and commonly known in the industry as a homopolymer can reach a crystallinity of 50%. A polyester polymer modified with a starting material other than terephthalic acid or ethylene glycol will have a crystallinity of less than 50%. For example, a polymer based on polyethylene terephthalate modified with 2 mol% of isophthalic acid residues and 2.7 mol% of diethylene glycol residues will have a maximum crystallinity of 45.3% (50-2-2.7).

More preferably, the tablets crystallize to a crystallinity of at least 25%, or at least 30%, or at least 32%. Since there is no preferred upper limit below the maximum degree of crystallinity calculated by this formula, in many cases the degree of crystallinity does not exceed 45% or not more than 40%.

The melting temperature of the tablets and the degree of crystallinity are determined by differential scanning calorimetry (DSC). The sample weight for this measurement is 10 ± 1 mg, and the sample consists of (1) part of a tablet, or more preferably (2) of several grams of cryogenically fragmented tablets. The first heating scan is carried out. The sample is heated from about 25 ° C to about 290 ° C at a rate of 20 ° C / min. The absolute value of the area of the endothermic melting peaks (one or more) minus the area of any exothermic crystallization peaks is determined. This area corresponds to the total heat of fusion and is expressed in J / g. The heat of fusion of 100% crystalline PET is assumed to be 119 J / g, and the mass fraction of crystallinity of the tablet is calculated as the quotient of dividing the total heat of fusion by 119. To obtain the mass percentage of crystallinity, the mass fraction of crystallinity is multiplied by 100. Unless otherwise specified, the melting point in each case is also determined by the DSC method.

The percentage of crystallinity is calculated from two values:

Melting point at low temperature peak: T _m1a

Melting point at high temperature peak: T _m1b

Note that in some cases, especially at low crystallinity due to crystallization at relatively low temperatures and / or short times, the rearrangement of crystals in the DSC cell during the first heating scan at a rate of 20 ° C / min can occur so quickly that the true melting point cannot be detected in the lower temperature region. A lower melting point can become noticeable with an increase in the rate of temperature rise in the DSC cell and with a decrease in the mass of the sample. For high-speed calorimetry, a Perkin-Elmer-Pyris-1 calorimeter is used. The mass of the sample is selected inversely proportional to the scanning speed. Approximately 1 mg of sample is taken at a rate of 500 ° C / min and approximately 5 mg at 100 ° C / min. Conventional DSC sample plates are used. To minimize the curvature of the baseline, a baseline is subtracted.

The low-temperature melting point and crystallinity of the polyester polymer are determined under different crystallization conditions and other factors. These conditions and factors include the regulation of temperature conditions during the crystallization of the polymer, the residence time in the crystallization zone, the nature of the polymer, the efficiency of the polymerisation medium of the polymer and the strains experienced by the polymer. Those skilled in the art of crystallization of polymers are aware of the conditions in conventional crystallizers necessary to determine the desired melting point and degree of crystallinity, and they can produce polymers with a melting point and degree of crystallinity at set intervals for a given polymer composition. For example, moderate crystallization temperatures of 100-200 ° C can be used for residence times from 1 minute to 3 hours, and the exact conditions depend on the nature of the polymer. Although these variables affect both the melting point and the degree of crystallization of the polymer, not all polyester polymers crystallizing to the same degree of crystallinity will have the same melting points and not all polyester polymers with the same melting point the same degree of crystallinity. Polyester polymers of different compositions will have different melting points compared to other polyester polymers, even with the same degrees of crystallinity. When processing individual samples of compositionally identical polyester polymers at different residence times under the same temperature conditions, polyester polymers with different degrees of crystallinity are also obtained. Accordingly, the degree of crystallinity may differ for two polymers of the same composition. In addition, the melting point may differ for two polymers of different compositions, even if they have the same degree of crystallinity.

The composition of the polyester polymer preferably includes at least 75% of the primary polyester polymer, more preferably at least 78 wt.% And may be 89 wt.% Or more, or 95 wt.% Or more of the primary substance or only the primary substance. The primary substance may be scrap or regrind polymer, but it is different from the polymer obtained by recycling the polymer after its use by the consumer. However, while the starting material may include scrap or regrind polymer, in one embodiment, the starting material does not contain scrap or ground material.

To obtain a primary polyester polymer with a molecular weight suitable for the preparation of vessels, i.e. It.V. = /> 0.72 dl / g, and subsequent thermal crystallization at relatively low temperatures, for example 100-200 ° C., In order to prepare the polymer compositions of the present invention, other methods can be used, in addition to the above-described melt polymerization . For example, a primary substance with a degree of crystallinity and a melting point outside these intervals can be re-melted, for example in an extruder, and then thermally crystallized at relatively moderate temperatures (100-200 ° C). Or, after melt polymerization to an intermediate molecular weight (It.V. from 0.20 to 0.70 dl / g), the polyester can be crystallized at moderate temperatures to crystallinity within a specified range and then polymerized in the solid state also at moderate temperatures 170-200 ° C to increase the It.V. value necessary for the preparation of vessels, although in this latter case they either increase the residence time in the solid-phase polymerization zone or even reduce the pressure, increase the inert gas flow rate and whether all these actions are combined.

It is preferable to obtain a polyester polymer by a melt polycondensation reaction to an It.V. at least 0.72 dl / g. In another preferred embodiment, a transportation container is provided comprising spheroids of polyesters that were not prepared by solid phase polymerization and had the It.V. value, melting point and AA shown here. In another embodiment, the spheroids are fed to a dryer, followed by processing the spheroids by melting and forming the article, and the spheroids were not obtained by solid phase polymerization and had the characteristics described above.

These options are preferred because tablets obtained by solid state polymerization are usually already crystallized and have a sufficiently high degree of crystallinity and a melting point, which avoids sticking under high temperature conditions, which is maintained in the solid phase polymerization zone. Crystallization preceding solid state polymerization usually allows tablets with a high degree of crystallinity to be obtained, which reduces agglomeration in solid phase reactors operating at high temperatures. Solid-phase tablets typically have a high melting point of the order of 220 ° C. or higher. High melting points have the disadvantage that they increase the temperature of the polymer melt in the extruder by several degrees, and this increases the time required for cooling the pressed products, the duration of the entire equipment use cycle, and also increases the likelihood of the formation of more acetaldehyde. In addition, tablets obtained by the method of polymerization in the solid phase, usually have a higher degree of crystallinity - more than about 50%, which increases the latent heat of fusion and, accordingly, the energy consumption for melting spheroids. Finally, during polymerization in the solid phase, the presence of the polymer for a long time at high temperature sometimes causes a real excess annealing of the polymer, as a result of which some spheroids in the melting zone do not completely melt, which leads to the deformation of pressed or extruded products. Accordingly, it is preferable not to polymerize the spheroids in the solid phase and it is better to obtain spheroids with the desired It.V. in the melt.

Preferably, the polyester spheroids of the present invention contain 10 ppm or less acetaldehyde (according to ASTM F2013-00, Determination of Residual Acetaldehyde in Polyethylene Terephthalate for Bottle Production Using an Automated Static Sampler from the Gas Phase over a Layer of Liquid and Capillary GC with Flame Ionization detector "), more preferably about 7 ppm or 3 ppm or less of residual acetaldehyde (AA). This can be achieved by gas blowing AA from spheroids. Alternatively or in addition to gas stripping, an acetaldehyde trap can be introduced into the polymer, which provides an additional advantage by reducing the rate of formation of acetaldehyde. If the trap is introduced after AA has been completely removed by gas blowing, the trap will reduce the amount of AA in the pressed product, for example in a bottle, due to the interaction with AA formed during melting. If an excess amount of trap is introduced before AA is blown out or instead of AA blown, then a certain amount of trap will not be consumed and this may reduce the amount of AA in the pressed product. Alternatively, there may be two or more additional steps for introducing an AA trap.

In a gas blowing operation, a gas such as air or an inert gas, for example nitrogen, is brought into contact with the spheroids of the polyester polymer either in a parallel flow or countercurrent, preferably countercurrent to the flow of spheroids in the vessel, in continuous or batch mode, preferably in continuous mode. The temperature of the gas supplied to the AA removal vessel is not particularly limited, but is preferably from ordinary temperature to 40 ° C. and more preferably is ordinary temperature. The temperature of the gas leaving the AA stripping vessel will be approximately equal to the temperature of the tablets introduced into the vessel. Thus, if spheroids are introduced at 100 ° C, the outlet gas temperature will be approximately 100 ° C +/- 20 ° C. The temperature of the gas leaving the vessel should not exceed the temperature at which there is an increase in the molecular weight of the spheroids in the solid state. The contact time with spheroids depends on the gas temperature and the mass ratio of spheroids / gas, but usually the contact time is in the range from 1 to 24 hours. The composition of the gas is not particularly limited and includes nitrogen, carbon dioxide and ordinary air. Gas does not need to be dried, as its function is not drying the tablets, but removing residual AA from them. If desired, however, the gas can be dried.

Although acetaldehyde can also be removed with gas in the dryer before being fed to the extruder to mold the article, it is preferable to feed polymer spheroids already containing 10 ppm or less residual acetaldehyde into the dryer to reduce the gas flow in the dryer and / or improve the quality of the products obtained in the extruder. Moreover, the method for removing AA from spheroids does not need dry gas, while during drying, a stream of dry air is pumped through the spheroids, firstly, to reduce their moisture and, secondly, to remove AA. Thus, in the method for removing AA, ordinary air can and is preferably used.

Thus, in one embodiment, spheroids with It.V. at least 0.72 dl / g and either with a degree of crystallinity in the range of 20% to T _cmax or with a melting point in the low-temperature peak in the range of 130-220 ° C, or with both of these parameters is fed into the vessel, preferably through the upper part of the vessel, in the form of hot spheroids (for example, with a temperature of 100-180 ° C) to increase the efficiency of AA removal and the formation of a layer of tablets moving by gravity to the bottom of the vessel with countercurrent gas circulation, for example, ordinary air, in the layer, the specified gas is fed into the vessel at D from the usual 180 ° C or from normal to 40 ° C to reduce the concentration of residual AA in the spheroids fed into the vessel. Spheroids are removed from the vessel after 5-30 hours using countercurrent gas. Although the vessel may be under pressure, it is preferred that there is no pressure therein, with the exception of the pressure generated by the gas stream. Preferably, the pressure in the vessel is about 0-5 psi. inch or was ordinary.

Gas can be supplied to the vessel using any conventional means, such as blowers, fans, pumps, etc. Gas can flow in the same stream with particles, countercurrent to them or across the stream. The preferred gas flow through the particle bed is countercurrent with respect to the particle flow. Gas can be supplied at any desired point in the vessel, effective in reducing the concentration of acetaldehyde in the particles supplied to the vessel. Preferably, the gas supply point is in the lower half of the layer in height and more preferably in the lower quarter of the layer height. The gas flows through at least a portion of the particle layer, preferably through at least 50 vol.% Of the layer, more preferably through at least 75% of the volume of the particle layer. Any gas, such as air, carbon dioxide, and nitrogen, is suitable for use in this invention. Some gases are preferred over others due to their availability or low price. For example, using air instead of nitrogen would result in significant savings in operating costs. It was believed that gaseous nitrogen is necessary when working with a hot gas stream through a layer of particles at temperatures above 180 ° C, for example in a mold, because nitrogen is inert in oxidative reactions, which can occur between many polyester polymers and ordinary oxygen and lead to discoloration of the tablets. However, if the process is carried out at a low temperature so that the temperature of the gas leaving the vessel does not exceed 190 ° C, then the discoloration of the particles will be minimal. In one embodiment, the gas contains less than 90 vol.% Nitrogen, less than 85 vol.% Nitrogen, or less than 80 vol.% Nitrogen. In another embodiment, the gas contains oxygen in an amount of 17.5 vol.% Or more. It is preferable to use air of conventional composition (the composition of the air in the plant where the vessel is located) or air that is not separated and not cleaned. It is advisable to supply normal air through the gas inlet. Although the air can be dried if desired, this is not necessary, as the goal is to remove acetaldehyde from the particles.

Any vessel is suitable for placing particles and passing gas and particles into or out of this vessel. For example, there is provided a vessel having at least an inlet for gas, an inlet for particles of a polyester polymer, an outlet for gas and an outlet for the resulting particles. Preferably, the vessel is insulated to maintain heat. It is desirable that the gas inlet and outlet of the obtained particles are located lower than the gas outlet and particle supply, it is preferable that the gas outlet and particle supply be closer to the top of the vessel, the gas supply and outlet of the obtained particles are closer to the bottom of the vessel. It is desirable to supply the gas into the bed within the vessel at about _^1/2 or _^1/4 of the bed height within the vessel. Particles are preferably fed into the upper part of the vessel and allowed to move under gravity to the bottom of the vessel, and it is preferable to let the gas flow countercurrent to the particle stream. Particles accumulate inside the vessel with the formation of a layer of particles, and the particles slowly sink under the action of gravity to the exit for the obtained particles at the bottom of the vessel. The height of the layer is not limited, but it is preferable that it is substantially constant in the continuous process and at least 75% of the height of the vessel with particles in the AA removal zone. Preferably, the vessel has an L / D ratio of at least 2, at least 4, or at least 6. Although the method can be carried out in batch or semi-periodic mode, in which the particles do not move, and the gas stream can be passed through the particle layer in any direction, it is preferable to implement a continuous method, so that the flow of particles supplied to the vessel, continuously moved from the place of supply of particles to the exit of the obtained particles.

A suitable velocity of the gas stream supplied to the vessel and passing through at least a portion of the particle layer is that rate sufficient to reduce the amount of residual acetaldehyde on the particles introduced into the vessel. For example, gas flow rates of at least 0.0001 std are suitable. cube ft / min (SCFM), or at least 0.001 SCFM, or at least 0.005 SCFM per one (1) pound of particles fed into the vessel per hour. High flow rates are also suitable, but they are not necessary, and the gas flow rate should be kept low enough to avoid unnecessary energy costs for gas pumps, fans or blowers. Moreover, it is undesirable to cool or dry the particles too much, since the realization of one or both of these goals usually requires the use of high gas flow rates. Preferably, the gas flow rate is not higher than 0.15 SCFM or not higher than 0.10 SCFM or not higher than 0.05 SCFM, or even not higher than 0.01 SCFM for every one (1) pound of feed particles per hour.

Alternatively or additionally, an acetaldehyde trap can be added to the polyester polymer near the end of polymer melting, or high viscosity (high IV) spheroids can be mixed with the trap. The trap should be introduced into the polymer melt as late as possible, preferably at the end of the final stage, i.e. close to the end of the last stage in a vacuum, or more preferably after the final stage. Those skilled in the art are aware of compounding to form polymer concentrates with a relatively high concentration of acetaldehyde traps. The polymer concentrates contain at least about 0.5 wt.% Traps in polyester. Such concentrates can be added through an extruder or liquid dispersions of these traps can be added via a pump at the end of polymer melting while the polymer is still melting. Alternatively, such particles of polymer concentrates can be mixed with spheroids of polymers at temperatures that support both types of particles in the solid phase. The mixture of polymer concentrate and spheroids can then be fed to an extruder, preferably an extruder, used to compress plastic products, such as bottle blanks. In the method for producing polymer particles in a melt, the removal of acetaldehyde and the installation of acetaldehyde traps introduced near the end or exit from the melting process can be combined. Particles leaving the removal zone can be mixed with the particles of the concentrate at temperatures at which both types of particles remain in the solid state.

Examples of effective acetaldehyde traps are any known to those skilled in the art, and in particular polyamides with amino groups at the ends and a molecular weight of less than 25,000 g / mol, less than 20,000 g / mol or less than 12,000 g / mol, and preferably the reaction products of adipic acid with m- xylylenediamine. The end groups of these polyamides form “imines” with AA and bind it to the ends of the polyamide chains. Amino acid-based polyamide traps for acetaldehyde are disclosed in US Pat. Nos. 6,444,283 B1, 6239233, 5340884, 5266413 and 5258233 and are incorporated herein by reference in their entireties. Alternatively, anthranilamide derivatives can be used, for example, disclosed in US Pat. Nos. 6,762,275 and 6,272,212 B1, incorporated by reference in their entirety.

Spheroids of a polyester polymer with desired properties can be fed into an extruder suitable for making vessels or sheet material, after drying to remove moisture from the spheroids. Accordingly, a method for processing a melt of spheroids of a polyester polymer is provided, comprising:

A) drying the spheroids of the polyester polymer in the drying zone to form dried spheroids;

B) introducing dried spheroids into the melting zone;

C) melting the spheroids of the polyester polymer in the melt processing zone; and

D) molding the product from a polymer melt,

in which the spheroids of the polyester polymer introduced into the drying zone have the characteristics described above.

The drying zone is a dryer. Dryers supplying material to the melting treatment zone reduce the moisture content in the spheroids. Moisture inside or on the surface of the spheroids supplied to the melt extrusion chamber will cause melting with the loss of excess It.V. at melt temperatures due to hydrolysis of ester bonds, which will have a negative effect on the characteristics of the polymer melt flow and the ratio of elongation of the preforms during bottle blowing. Therefore, before extrusion, the spheroids are dried in a stream of hot dry gas at a temperature of 140 ° C or higher to remove most of the moisture from the surface and from the volume of particles. It is desirable to dry the spheroids at high temperatures from 140 ° C or higher in order to reduce the residence time of the spheroids in the dryer and increase productivity. In general, the usual residence time of spheroids in the dryer at ordinary temperatures (140-190 ° C) will average from 0.75 hours to 12 hours.

You can use any traditional dryer. Spheroids can be brought into contact with a stream of heated air or an inert gas such as nitrogen in order to increase the temperature of the spheroids and remove volatile compounds from them, and spheroids can also be mixed using rotary mixing plates or blades. The inert gas flow rate, if used, is determined by the balance of energy and residence time of the spheroids and should preferably be such as to avoid the formation of a fluidized bed of spheroids. Suitable gas flow rates are in the range from 0.05 to 100 SCFM per pound per hour of spheroids discharged from the dryer, preferably from 0.2 to 5 SCFM per pound / hour of spheroids.

The spheroids of the invention have a lower tendency to agglomerate in the dryer at drying temperatures than particles of a traditional geometric shape that were not obtained by solid state polymerization or possessed the same characteristics.

After drying, the spheroids are fed into the melt processing zone to form a molten polyester polymer, followed by molding an article, for example a sheet material or a compression mold. You can use any traditional method of melting spheroids and forming products. Suitable melt processing zones include extruders equipped with a drum, one or more screws in the drum, a motor for rotating the drum, heating elements to provide heat flow through the drum to the spheroids, and a punch through which the molten polymer is pressed. The punch may be flat, optionally associated with a thermo-forming mold. Another melt processing zone is an injection molding machine equipped with the same elements, except that instead of a punch a nozzle is used, through which the polymer is pressed into the gating system, which directs the polymer into one or more molds. An example of a mold is a mold for making a bottle.

To improve the working properties of the polyester polymer, other components can be added to the composition of the present invention in the melt processing zone and the production of the article or in the method for producing the polyester polymer in the melt. These components can be added directly to the mass of the polyester as a dispersion in a liquid carrier, or added to the mass of the polyester in the form of a polyester concentrate containing at least about 0.5 wt.% Of the component included in the mass of the polyester. Types of suitable components may include: seeds for crystallization, effective modifiers, surface lubricants, stabilizers, reagents that prevent particles from sticking together; antioxidants; ultraviolet absorbing reagents; metal deactivators, dyes, nuclei; compounds that lower the concentration of acetaldehyde; compounds that increase the rate of reheating; additives that prevent sticking to bottles, such as talc; fillers, etc. The resin may also contain small amounts of branched reagents, for example trifunctional or tetrafunctional comonomers, such as trimellitic acid anhydride, trimethylolpropane, pyromellitic dianhydride, pentaerythritol and other polyacids or polyols forming polyesters known in the art. All these and many other additives and their use are well known to specialists and do not require detailed consideration. Any such compounds may be used in the present composition.

In each of these options, manufactured products are not limited and include sheet material and bottle blanks. Blanks for bottles can be formed by blowing and extracting into bottles in the usual way. Thus, a variant of bottles made from the spheroids of the present invention or by any methods of the invention or made by any conventional melt processing method using the spheroids of the present invention is provided.

Of the spheroids obtained by the method of the present invention, it is possible to make not only vessels, but also other products, for example sheet material, film, bottles, pallets, other containers, rods, tubes, caps, wire and fibers and other molded products. Examples of bottle types that are made from the crystallized spheroids of the present invention are beverage bottles made from polyethylene terephthalate suitable for storing water or carbonated drinks, and heat-resistant beverage bottles that can be bottled hot.

The invention will now be explained using the following non-limiting illustrative examples.

Examples

The substances described herein were used in the following examples.

Voridian PET CB12 Polyester Polymer is manufactured by Eastman Chemical Company. CB12 tablets are close to cylindrical in shape and are produced by cutting a sharp polymer tape. CB12 tablets are solid and semi-crystalline.

UWC and UW AC tablets were prepared in a tabletting apparatus under a layer of water from a Voridian PET CB12 polyester polymer. Although It.V. these tablets were not measured, the polyester CB12 thus obtained usually has It.V. from 0.78 to 0.82 dl / g. These tablets are in the form of spheroids as defined above.

UWC tablets were prepared by cutting the resin under a layer of water at a water temperature of about 160 ° C. to form semi-crystallized tablets. The residence time of the tablets in an airtight crystallizer with hot water was approximately 5 minutes.

UW AC tablets were prepared by cutting the resin under a layer of water at a temperature of about 90 ° C, so that the tablets were amorphous. Then they were crystallized in a small, batch-shaped crystallized vane mold. Tablets at room temperature were placed in a crystallizer preheated to 210 ° C. The average temperature of the tablets (measured by a gun type IR pyrometer) was approximately 157 ° C after 30 minutes and approximately 162 ° C after 35 minutes. Then the tablets were unloaded in containers and allowed to cool naturally.

Polymer 16-3001 is modified with 3.0 mol% of isophthalic acid and about 3.6 mol% of diethylene glycol. It was polymerized in the melt to a final value of It.V. approximately 0.82 and tableted by cutting blanks to form conventional almost cylindrical tablets. The tablets were crystallized continuously by passing through two horizontal elongated vessels with shirts, in which mixing was carried out using a longitudinal shaft equipped with radially directed blades. The heating fluid circulating in the jacket was maintained at a temperature of 180 ° C, so that the tablets leaving the vessel had a temperature of about 165 ° C. The residence time of the polymer in the vessels was approximately 30 minutes.

Polymer 12-3001 is modified with 3.0 mol% of isophthalic acid and about 3.6 mol% of diethylene glycol. It was polymerized to a final value of It.V. approximately 0.82 in the melt and tableted by cutting blanks with the formation of conventional almost cylindrical tablets. The tablets were crystallized in a biconical rotary dryer by heating the polymer to 180 ° C and then cooling to normal temperature.

Table 1 summarizes the main data on spherical and cylindrical tablets used in this work.

RPU tablets were prepared on a Roll Processing Unit made of Voridian PET CB12 polyester polymer. RPU tablets were in the form of “tiles”, and all the tablets used in this work had nominal lateral sizes of 3 × 3 mm and a thickness of 2.25-2.5 mm (0.090-0.100 in). RPU tablets were prepared at a rate of approximately 325 lb / h with a predetermined calender temperature of approximately 150 ° C.

Table 2 shows the main data on the RPU tablets used in this work. The temperature of the layer was measured with a gun type IR pyrometer, i.e. it was the temperature of the surface of the layer. The magnitude of It.V. tablets RPU 150 and RPU 179 were not measured, but (based on many measurements on other tablets obtained by similar drying and extrusion methods), it can be expected to be 0.79-0.81. Crystallinity was determined in two ways - by DSC for the first heating at a speed of 20 ° C / min by summing the heat of fusion (in J / g) over all melting peaks minus the heat of any crystallization peaks after dividing by 119 (heat of fusion in J / g 100% crystalline PET).

Table 1 Characteristics of cylindrical and spherical tablets Pill ID Crystallization Geometry pills It.V. (dl / g) Crystallinity (wt.% According to DSC) Method Pace. (° C) Time (min) CB12 Industrial crystallizer and solid stator ~ 210 ~ 500 Cutting a cylindrical workpiece 0.84 48% UWC Continuous tableting under a layer of water and crystallization under a layer of water ~ 160 ~ 5 Uw spheroid N / a 41%

Uwac Periodic crystallization in air by contact of amorphous particles with the surface of a hot shirt 157-162 ~ 5 + 30 min rise Uw spheroid N / a 37% 16-3001 Continuous crystallization in air by contact of amorphous particles with the surface of a hot shirt ~ 165 ~ 30-60 Cutting a cylindrical workpiece 0.82 35% 12-3001 Periodic crystallization in air by contact of amorphous particles with the surface of a hot shirt ~ 180 ~ 120-180 Cutting a cylindrical workpiece 0.82 37% table 2 Characteristics of RPU tablets ID tablet Calender Temperature (° C) Layer temperature (° C) It.V. (dl / g) Crystallinity (wt.% According to DSC) at the inlet of the drum at the exit of the drum RPU 150 142 120 150 N / a 41% RPU 166 145 134 166 0.76 42% RPU 179 155 147 179 N / a 38%

Example 1

The tablets were heated in a dryer hopper. The dryer was a block of five bins equipped with one Conair dryer using a closed collector system. Typically, test tablets are placed in hopper 1 (the first hopper in the feed header), control tablets are placed in hopper 3, and the air valves in the hoppers 2, 4, and 5 are closed. This procedure was repeated to avoid too much air flow through the hopper 1.

Figure 1 illustrates the geometry and dimensions in inches of the hopper of the dryer used in the experiments.

The base of the hopper was closed using a simple crane with a sliding gate. In order to fully open the exit from the hopper, the valve can be fully extended. Preliminarily, the dryer was carefully heated to operating temperature before loading the tablets into the hopper. Approximately 20 pounds (approximately 80% of the hopper capacity) of control tablets (typically CB12) were placed in hopper 3, and a similar number of test pellets were placed in hopper 1. A protected thermocouple was introduced into the layer of test tablets so that its end was several inches below the surface layer, and periodically recorded temperature.

The residence time of the tablets in the hopper 1 was usually 3.0 hours. The damper was removed from the shut-off valve, and if the tablets did not fall out freely from the hopper, they hit the base of the hopper near the gate sharply with the edge of the damper, holding it by hand. This “shaking” was repeated until the tablets began to fall out, up to 20 strokes. If after this the tablet layer remained clogged, a rod was inserted into the tablet layer through an open shut-off valve. Usually, only one piercing with the rod was always enough to cause a rapid flow of tablets and completely empty the hopper; repeated strikes or “breaking” of the layer was never required. So it was when the flow of tablets was caused by shaking; as soon as the release of the tablets began, the entire layer of tablets freely and quickly fell out of the hopper. In all cases, regardless of the degree of sticking in the hopper, as soon as the tablets flowed out of the hopper, no residual adhesion was observed between the tablets — no clots of tablets, “doublets” or “triplets” were noted, but only a bucket of individual tablets.

A representative scan of the first heating by DSC was performed and analyzed. Basically, no explicit relationship was found between the temperature at which transitions were observed by DSC and tablet cohesion.

DSC data for all RPU pellets fed to the dryer were very close and were characterized by a deviation of one melting point from the baseline at 195-200 ° C and a peak at 250-252 ° C. DSC data for tablets 16-3001 and tablets UWC AC and UWC showed an obvious feature, which is the deviation of the low-temperature endothermic melting peak from the baseline at about 160 ° C with a center at 181 ° C. The low-temperature endothermic melting peak had a maximum at 174 ° C, which indicated a crystallization temperature of the tablet 155-160 ° C. The peak deviated from the baseline at 135-140 ° C, but after a slight adjustment of the slope of the baseline, this temperature increased by 20-25 ° C.

The final temperature of the tablets in the hopper was 190 ° C. After 30 minutes the temperature was 180 ° C; after 45 minutes - 187 ° C; after 60 minutes - 188 ° С and after 90 minutes and more - 190 ° С. The temperature of the tablet came close to the equilibrium value after about 45 minutes and precisely reached its limit value after about 90 minutes.

The results of the adhesion tests of the tablets are shown in table 3. As shown above, the tablets were heated in hopper 1 for 3 hours to the indicated temperature, the shut-off valve shutter was removed and the shut-off valve at the base of the hopper was sharply hit with a slider in the right place until the falling of the tablets began . If the flow of tablets did not begin to move after 20 such shakes, the experiment was terminated and "> 20 shakes" were included in the test procedure.

It should be noted that ordinary CB12 solid tablets participating in the sticking experiment moved freely (shaking was not required to start the movement) at approximately 185 ° C, the highest temperature that can be achieved in the dryer.

Table 3 The number of shakes required to start the movement of the tablets at several temperatures Type of pills The number of shakes needed to start @ 175 ° C @ 181-182 ° C @ 184-186 ° C RPU 150 Not enough data > 20 Estimated> 20 ¹ RPU 166 5 7 > 20 RPU 179 5 > 20 Estimated> 20 ¹ 16-3001 > 5 > 20 Estimated> 20 ¹ Uwac 0 ≤3 3 UWC 0 one one Note. Not measured, but concluded that> 20, on the assumption that adhesion does not decrease with increasing temperature.

Obviously, the spheroidal tablets of both UW AC and UWC are significantly less sticky at elevated temperatures than RPU tile tablets or 16-3001 cylindrical tablets. At approximately 175 ° C, spheroidal tablets obtained by crystallization in both air and water moved freely, while for all other types of tablets, at least five shakes were required to initiate movement (data are insufficient to confirm with certainty this is for RPU 150 tablets, but based on the available data, you can take this with some certainty). Even more striking differences in adhesion are seen at 181-182 ° C, when only one shake is needed to initiate the movement of both types of spherical tablets (measured for UWC, interpolated between two points for UW AC), and RPU 166 tablets required seven shakes, and all other types of tablets required> 20 shakes. At 186 ° C, the UWC tablets continued to move freely after one shake, and the UW AC tablets moved freely after three shakes, while all cylindrical and tiled tablets remained sticky after 20 shakes.

Tablets 16-3001 were obtained by crystallization at a temperature and by a method very close to the conditions for the preparation of UW AC tablets, and both types of tablets have very similar compositions and intrinsic viscosity.

Example 2

In this series of experiments, the angle of natural shedding of PET tablets of various shapes and morphologies was analyzed. The natural shedding angle is a measure of the frictional properties of the granules and may be related to the tendency of the tablets to stick together in the dryer. A higher shedding angle means that the tablets are more likely to stick together in the dryer, while a smaller shedding angle indicates a more freely flowing material.

Figure 2 and 3 shows a device for determining the angle of natural shedding of granular substances. These devices are designed to work in a large dryer at elevated temperatures. The dryer is equipped with a screen for directing the flow of air through these devices and efficiently heating the tablets.

A device for determining the angle of natural shedding of granular materials through the shutter (Fig. 2) is a box consisting of a base 1 of wire mesh, two fixed side walls 3, a fixed back wall 5 and a vertical removable side, or shutter 7. Internal dimensions of the box for determining the angle of natural shedding of granular materials through the shutter is 5.75 × 5.75 × 8.00 inches. At the beginning of the test, the shutter 7 is held in place by means of a latch and the box is filled with tablets 9. In the dryer, they are detected for zero time. After some time, the dryer is opened and the temperature of the tablets is measured with a Raytek Raynger MX IR pyrometer (model # RAYMX4PCFU). Then, the shutter 7 is slowly lowered vertically until the upper edge of the shutter 7 is below the base 1, and the shutter 7 can be removed. When lowering the shutter 7, several tablets 9 fall out of the box. After stopping the flow of tablets 9, the height H of the tablet layer is measured on the back wall 5. The shedding angle φ can be calculated by the formula: tanφ = H / D, where D is the depth of the layer and corresponds to the horizontal measurement of the side wall of the box 1.

A device for determining the angle of natural shedding of granular materials in the mass (figure 3) is a horizontal platform inside a moving box. The box has four welded sides 21 and a wire mesh bottom. The internal dimensions of the box for determining the angle of natural shedding of granular materials in the mass are 5.75 × 5.75 × 3.00 inches. The box is mounted on a stand 23 with holes for air flow through the tablets 25. The stand has supports 31, a tension screw 33 and a head for setting the height 35. A horizontal disk 22 with a radius of R = 1.5 inches was attached to the stationary rod 37. The rod 37 passed through the holes in the bottom of the box and stand 23. At the beginning of the test, the box was lifted so that the disk 22 touched the bottom of the box. Then the box was filled with 25 tablets. The dryer was set to zero time. After some time, the dryer was opened and the temperature of the tablets was measured with a Raytek Raynger MX IR pyrometer (model # RAYMX4PCFU). Then the box was slowly lowered by turning the head 35 until the tops of the walls of the box 21 were lower than the disk 22. The height H of the pile of tablets 25 remaining on the disk 22 was measured, and the tipping angle was calculated by the formula tanφ = H / R.

Since the angle of natural shedding depends on temperature, these measurements are carried out by heating inside the dryer. If the tablets are allowed to cool, a handful of tablets in the test fixtures will settle, which will lead to a decrease in the measured shedding angle.

Drying time was 3-8 hours at temperatures of 165-185 ° C. These conditions were chosen in order to get closer to the drying operating conditions commonly used in industry.

The test results of both methods are presented in tables 4 and 5. The actual temperature of the tablets noticeably changed at a given temperature of the dryer. The changes reached 20 ° C, so all data must be analyzed based on real temperatures. In many examples, for a given temperature of the dryer, with an increase in the residence time in the dryer, a shift to higher real temperatures of the tablets was observed. The temperatures of the tablets in the shutter method were about 10 ° C higher than in the mass test method. In general, the data show that the actual temperature of the tablets affects the shedding angle more strongly than the time spent in the dryer.

The damper test invariably gives higher angles of natural shedding. While the temperature difference may partially explain these differences, the temperature interval of 20 ° C observed in each test method with the established experimental method gives a smaller difference than the temperature difference of 10 ° C between the two test methods. Thus, we can conclude that the geometry of the testing method has a significant impact on the results.

Although temperature and time have an effect on the angle of shedding, the influence of the geometry of the tablets and their morphology is more significant. Figure 4 shows a comparison of the angles of natural shedding for five substances obtained by the shutter method. Five point data for each substance represents all the studied time / temperature combinations. Over the entire range of drying times and temperatures, the UWC spheroidal substances turned out to have a significantly larger shedding angle than other cylindrical or tiled substances. From these data it follows that the geometry of particles is a more important factor for lowering the angle of natural shedding than the morphology of a substance.

Figure 5 shows a similar analysis for tests in bulk. Five point data for each substance represents all the studied time / temperature combinations. In this example, the UWC spheroidal substances had a significantly larger shedding angle than other cylindrical or tiled substances. From these data it follows that the geometry of particles is a more important factor for decreasing the shedding angle than the morphology of a substance.

From consideration of both tests for the angle of natural shedding, it follows that spheroidal tablets of UWC have the lowest angle of shedding. Of the differences in the test results with the shutter and in the mass, it is difficult to detect a noticeable dependence on the heating time for tablets with the same geometry and very similar compositions (16-3001, 12-3001 and CB12). At the beginning of the experiments, the hypothesis was considered that crystallization during heating and / or solid state reduces the amount of amorphous substance that can participate in the interaction of tablets at drying temperatures and, thus, heating would lead to reduced shedding angles. Although some indication of this is given by the testing method in bulk, but the influence of the geometry of the tablets is much stronger.

Modeling data on the angle of shedding from experiments at elevated temperatures does not produce noticeable effects in addition to distinguishing materials. When the sinking angle was included in the simulation at room temperature, a significant influence of the temperature and nature of the substance with a confidence interval of 95% was noted, while the drying time was not a decisive parameter.

The following conclusions can be drawn from this example:

a) UWC spherical tablets have a markedly lower shedding angle compared to other studied tablets. It is believed that tablet geometry is the primary factor responsible for this result.

b) The drying time does not seem to have a noticeable effect on the angle of natural shedding, with the exception of drying at the highest temperatures and for a long time.

c) In the entire temperature range that is commonly used, the angle of natural shedding is very weakly dependent on temperature and much more dependent on the shape of the tablet.

Thus, spheroidal tablets with a shedding angle of less than 34.0 ° or less than 32.0 ° or 31.0 ° or less or 30.0 ° or less, determined using a test with a shutter at a real tablet temperature of 165 ° C after 5 hour.

Claims (43)

1. An array of spheroids of a polyester polymer with the following characteristics:
A) average characteristic viscosity It.V. at least 0.72 dl / g and either
B) melting points characterized by:
a) at least two melting peaks, wherein one of the at least two melting peaks during the first scan is the melting point in the low-temperature peak of DSC with a peak temperature in the range of 140-220 ° C and the absolute value of the area of the endothermic melting peak is at least 1 J / g, or
b) one or more melting points, which upon first scanning during heating give a DSC curve deviating from the baseline in the endothermic direction at a temperature less than or equal to 200 ° C, or
C) a low degree of crystallinity in the range of at least 20% and a maximum degree of crystallinity T _cmax defined by the equation:
T _cmax = 50% -CA-OH,
where CA is the total molar percentage of all carboxylic acid residues other than terephthalic acid residues, based on 100 mol% of carboxylic acid residues in the polyester polymer, and OH is the total molar percentage of residues of compounds with hydroxyl functional groups other than ethylene glycol residues , based on 100 mol.% residues of compounds with hydroxyl functional groups; or both B) and C). 2. The array according to claim 1, in which the array contains at least 75% of the primary polyester polymer. 3. The array according to claim 2, in which the array contains residual acetaldehyde in an amount of 10 ppm or less. 4. The array according to claim 1, in which the spheroids have an angle of natural shedding of less than 34.0 ° according to the determination through the damper at a real temperature of the spheroids of 165 ° C after 5 hours 5. The array according to claim 4, in which the angle of natural shedding is less than 32 °. 6. The array according to claim 5, in which the angle of natural shedding is less than 31 °. 7. The array according to claim 1, in which the spheroids have a roundness distribution and a distribution index of less than 1.4. 8. The array of claim 5, wherein the roundness distribution index is 1.2 or less. 9. The array according to claim 1, in which the spheroids are characterized by both parameters B) and C). 10. The array according to claim 1, in which the spheroids of polyester polymers contain:
(a) a carboxylate component containing at least 80 mol% of terephthalic acid residues or terephthalic acid derivatives, or mixtures thereof, and
(b) a hydroxyl-containing component, which includes at least 80 mol.% ethylene glycol residues,
based on 100 mol.% residues of the carboxylate component and 100 mol.% residues of the hydroxyl-containing component in the polyester polymer. 11. The array of claim 10, in which the spheroids of polyester polymers contain:
(a) a carboxylate component containing at least 90 mol% of terephthalic acid residues and / or terephthalic acid derivatives, and
(b) a hydroxyl-containing component comprising at least 90 mol% of ethylene glycol residues, based on 100 mol% of the carboxylate component residues and 100 mol% of the hydroxyl-containing component residues in the polyester polymer. 12. The array according to claim 1, for which the low-temperature peak corresponding to the melting point of the spheroids is in the range of 160-210 ° C, the degree of crystallinity is in the range of 25-45%, the numerical average mass of the spheroids is at least 1.0 g per 100 particles and not more than 100 g per 100 particles and a concentration of residual acetaldehyde of 7 ppm or less. 13. The array according to item 12, in which the spheroids have a characteristic viscosity It.V. from 0.75 dl / g to about 1.1 dl / g and contain 2 ppm or less of residual acetaldehyde. 14. The array according to claim 1, for which the low-temperature peak corresponding to the melting point of the spheroids has a shoulder. 15. The array according to claim 1, in which the characteristic viscosity of It.V. spheroids is in the range of 0.78 dl / g to 1.1 dl / g. 16. The array according to claim 1, in which the characteristic viscosity It.V. spheroids is in the range of 0.81 dl / g to 1.2 dl / g. 17. The array according to claim 1, in which the spheroids are contained in a container for transportation and spheroids are not obtained by solid state polymerization. 18. The array according to claim 1, in which the spheroids are obtained by cutting a polyester polymer under a layer of water. 19. The array according to claim 1, in which the spheroids have a degree of crystallinity as a result of thermal crystallization of spheroids in a liquid medium containing water, at a temperature above T _{g of the} polyester polymer. 20. A method of forming a product of a polyester polymer, including
A) drying the spheroids of the polyester polymers in the drying zone to produce dried spheroids, wherein said dried spheroids of the polyester polymers are at least 75% primary polyester polymer and have an average intrinsic viscosity of It.V. at least 0.72 dl / g
B) introducing dried spheroids into the fusion treatment zone,
C) melting the spheroids of the polyester polymers in the fusion treatment zone; and
D) molding a molten polymer product,
moreover, spheroids of polyester polymers introduced into the drying zone are not obtained by solid phase polymerization. 21. The method according to claim 20, in which the spheroids supplied to the drying zone contain residual acetaldehyde in an amount of 10 ppm or less. 22. The method according to claim 20, in which the spheroids have a degree of crystallinity of 25-45%. 23. The method according to claim 20, in which the spheroids have one or more melting points, characterized by:
a) at least two melting peaks, wherein one of the at least two melting peaks during the first heating scan is a low-temperature DSC peak corresponding to the melting point, with a peak temperature in the range of 140-220 ° C, and the absolute value of the area of the endothermic melting peak equal to at least 1 J / g, or
b) one or more melting points, which upon the first heating scan give a DSC heating curve deviating from the baseline in the endothermic direction at a temperature less than or equal to 200 ° C. 24. The method according to claim 20, in which the spheroids supplied to the drying zone have
A) average characteristic viscosity It.V. at least 0.72 dl / g
and either
B) melting points characterized by:
(i) at least two melting peaks, wherein one of the at least two melting peaks during the first heating scan is a low-temperature DSC peak corresponding to the melting point, with a peak temperature in the range of 140-220 ° C. and the absolute value of the area of the endothermic melting peak equal to at least 1 J / g, or
(ii) one or more melting points, which upon a first heating scan give a DSC heating curve deviating from the baseline in the endothermic direction at a temperature less than or equal to 200 ° C,
or
C) a low degree of crystallinity in the range of at least 20% and a maximum degree of crystallinity T _cmax defined by the equation:
T _cmax = 50% -CA-OH,
where CA is the total molar percentage of all carboxylic acid residues other than terephthalic acid residues, based on 100 mol% of carboxylic acid residues in the polyester polymer, and OH is the total molar percentage of residues of compounds with hydroxyl functional groups other than ethylene glycol residues , based on 100 mol.% residues of compounds with hydroxyl functional groups; and
D) 10 ppm or less of residual acetaldehyde. 25. The method according to claim 20, in which the spheroids supplied to the drying zone have an angle of natural shedding of less than 34.0 ° according to the determination through the damper at a real temperature of the spheroids of 165 ° C after 5 hours 26. The method according A.25, in which the angle of natural shedding is less than 32 °. 27. The method according to claim 20, in which the spheroids supplied to the drying zone have a roundness distribution and a distribution index of less than 1.4. 28. The method according to claim 20, in which the indicator is 1.2 or less. 29. The method according to claim 20, in which the spheroids of polyester polymers supplied to the drying zone, contain
(a) a carboxylate component containing at least 80 mol% of terephthalic acid residues or terephthalic acid derivatives, or mixtures thereof, and
(b) a hydroxyl-containing component, which includes at least 80 mol.% ethylene glycol residues,
based on 100 mol.% residual hydroxyl-containing component and 100 mol.% residual hydroxyl-containing component in a polyester polymer. 30. The method according to claim 20, in which the spheroids of polyester polymers supplied to the drying zone contain
(a) a carboxylate component containing at least 90 mol% of terephthalic acid residues and / or terephthalic acid derivatives, and
(b) a hydroxyl-containing component, which includes at least 90 mol.% ethylene glycol residues,
based on 100 mol.% of the residues of the carboxylate component of the acid and 100 mol.% of the residues of the hydroxyl-containing component in the polyester polymer. 31. The method according to claim 20, in which the low-temperature peak corresponding to the melting point of the spheroids supplied to the drying zone is in the range of 160-210 ° C, the crystallinity is in the range of 25-45%, the numerical average mass of the spheroids is at least 1.0 g per 100 particles and not more than 100 g per 100 particles and the residual acetaldehyde is 7 ppm or less. 32. The method according to claim 20, in which the spheroids supplied to the drying zone have an intrinsic viscosity It.V. in the range of 0.78 dl / g to 1.1 dl / g. 33. The method according to claim 20, in which the spheroids supplied to the drying zone, receive a sharp polyester polymer under a layer of water. 34. The method according to claim 20, in which the spheroids have a degree of crystallinity as a result of thermal crystallization of spheroids in a liquid medium containing water at a temperature above T _{g of the} polyester polymer. 35. The method according to claim 20, in which the product is a sheet material. 36. The method according to paragraph 24, in which the product is a sheet material. 37. The workpiece obtained by the method according to claim 20. 38. A bottle formed by blowing with a hood, obtained by the method of claim 20. 39. The workpiece obtained by the method according to paragraph 24. 40. A bottle formed by blowing with a hood, obtained by the method of paragraph 24. 41. The workpiece obtained from the array according to claim 1. 42. A bottle formed by blowing with a hood, obtained from the array according to claim 1. 43. The sheet material obtained from the array according to claim 1.

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