HK1200858B - Concentrated polymer composition ("masterbatch"), production method thereof and use of same for adding to polyester fibres and filaments - Google Patents

Abstract

The invention pertains to the field of synthetic-fibre production for the textile industry and relates to the design and use of a concentrated polymeric composition ("masterbatch") comprising: a polymer from the metlacrylate family as a support polymer, representing between 30 wt.-% and 99 wt.-% of the polymer composition; and at least one additive and/or pigment representing between 1 wt.-% and 70 wt.-% of said composition. During the extrusion process, the composition of the invention is incorporated into the molten fibre- and filament-forming polyester polymers in order to increase speed in the spinning process (productivity).

Description

Concentrated polymer compositions ('masterbatches'), methods of making and use of adding to polyester fibers and filaments

The purpose of the invention is as follows:

the present invention is in the field of synthetic fiber manufacture, primarily for the textile industry, and relates to the manufacture of synthetic yarns and fibers from polyester polymers using a melt spinning process.

In particular, the present invention relates to the design and use of a concentrated polymer composition ("masterbatch") and incorporation into molten fiber and filament forming polyester polymer during extrusion to increase the speed (productivity) of the spinning process.

In particular, the polymer compositions of the invention are preferably applied to pre-oriented yarns, with the aim of spinning them at a faster speed, and with a rheological behaviour (load-elongation curve) similar to that when spun at a slower speed without the inclusion of "masterbatch".

Background art:

polymeric supports, known in the art as "carriers", are media in which concentrated colored pigments or other additives are dispersed, known as "masterbatches", which are dosed into the host polymer to modify the properties of the fibers and filaments, making products with different technical characteristics and specific improvements for the applications for which they are designed.

There are many different "masterbatches" on the market, the composition of which depends on the use for which they are intended. However, the use of Polymethylmethacrylate (PMMA) as a support or carrier for additives in "masterbatches" has not been known so far, with the aim of increasing productivity in melt spinning processes.

In the melt spinning process, PMMA is used as an additive to reduce orientation, as is the case in spanish patent ES2210929, which relates to polyester fibers and filaments comprising PMMA added in an amount of 0.1 to 4 wt% relative to the polymer forming the thread. PMMA is injected into a stream of the main melt of polyester; it disperses and homogenizes in the molten polymer, resulting in increased elongation at break (elongation) at high spinning speeds.

It is used for the same purpose in US2004076823 and japanese patent JP 11350277. Patent US2004076823 relates to a coextrusion composition of PTT polyester fibers (polytrimethylene terephthalate) added with PMMA resin, wherein the elongation at break of the fibers is increased by 30%, so that the spinning speed is increased. Patent JP11350277 relates to its role as a limiter of the crystalline orientation when PMMA is used as an additive in the composition of polyester yarns or filaments, which increases the elongation at break of the fiber, with the aim of preparing a bulked yarn (HB) by blending yarns with different shrinkage capacities (differential shrinkage).

It is a well-known fact that industry needs to increase productivity without affecting the quality of the manufactured products. This need is particularly acute in the case of fibers made in the textile industry. The present invention provides a solution to this problem using a "masterbatch".

It is known that the inclusion of a particular "masterbatch" can have a significant impact on color, properties and cost of the spinning process. Proper selection and design will adjust the effectiveness of the additive and its compatibility with the polymer component of the fiber.

Therefore, there is a need to prepare "masterbatches" which support the polymer to achieve dispersion of high concentrations of additives without changing its properties during and after the dispersion and which enable improved productivity to be obtained during spinning of polyester fibers and filaments.

Disclosure of Invention

The main object of the present invention is to compound and use a polymer composition ("masterbatch") comprising a polymer of the methacrylate family as a support ("carrier") polymer for pigments and/or additives dispersed therein for addition to a molten fiber-forming polyester polymer during extrusion, with the aim of achieving an increased productivity during spinning.

This object is achieved thanks to the optimum characteristics provided by the polymers of the methacrylate family when used as a carrier in a "masterbatch" (in which at least one pigment and/or additive is dispersed).

Preferably, the family of components used as support polymer "carriers" in the "masterbatch" is Polymethacrylate (PMMA).

This polymethacrylate polymer used as a support polymer in "masterbatch", and the results obtained from its use, will be used hereinafter to conveniently explain the present invention.

However, this explanation should not be understood as being limited to the use of PMMA as the support polymer, since similar results can be obtained when other polymers of the methacrylate family are used as an alternative to PMMA.

Thus, hereinafter, PMMA will be used as the polymeric support, recognizing that any reference to this polymer may also apply to other members of the methacrylate family.

Advantageously, the use of a "masterbatch" comprising PMMA as carrier does not cause processing problems due to degradation of this polymer during mixing with the polymer to which it is dosed in the extruder.

PMMA is an inert material that is incompatible (miscible) with the thermoplastic polymer from which the fibers are formed. It is an amorphous plastic and its effect on these polymers is limited to its rheological properties, without producing any structural changes, and it can therefore be used as a "carrier" in "masterbatches".

Sometimes, the support polymer may be composed of PMMA and one or a combination of at least two of the following polymers: polybutylene terephthalate (PBT), polyethylene terephthalate (PET), polytrimethylene terephthalate (PTT) or polylactic acid (PLA), with the aim of optimizing the best properties of the "masterbatch".

As already mentioned, the polymer composition of the present invention is added to the fiber-forming molten polyester polymer during extrusion. The designation "polyester" includes all members of the polymer family whose chains are formed from monomers joined by ester functional groups, such as polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polytrimethylene terephthalate (PTT) or polylactic acid (PLA).

After continued investigation and testing, it has been defined that for the purpose of achieving the desired increased productivity during spinning, the composition of the "masterbatch" to which the present invention relates will preferably comprise Polymethylmethacrylate (PMMA) having a molecular weight of 10,000-500,000g/mol and will be present in an amount of 30 to 99 wt.% of the concentrated polymer composition or "masterbatch".

Also, it has been determined that the final concentration of PMMA in the fiber-forming polymer to be extruded preferably amounts to at most 10 wt.% of the final mixture (i.e. molten polymer), thus achieving a very important increase in productivity during spinning.

The polymer composition of the invention, in addition to PMMA, comprises 1 to 70 wt% of pigments and/or additives and optionally other polymers and dispersants. Wherein the percentage of pigments and/or additives depends on the type and nature of the pigments and additives, and the polymer to be added.

The pigment used in the "masterbatch" is selected from organic pigments, inorganic pigments or mixtures thereof.

Pigments preferably used in the "masterbatch" of the polymer composition of the invention are carbon black or titanium dioxide (TiO)₂). In this regard, the present invention describes the existence of a surprising and unexpected synergistic effect derived from the combination of PMMA and each of these pigments. This combination enhances orientation reduction and allows increased productivity to be obtained without having to reach excessively high levels of use.

Furthermore, the additives used in the manufacture of the polymer composition are selected from: lubricants, antistatic agents, plasticizers, stabilizers, antioxidants, compatibilizers, and flame retardants, as well as mixtures or combinations of these products.

If the support polymer consists of a mixture of PMMA and other polymers (such as PBT, PET, PTT and PLA), these polymers will be present in an amount of 50% to 70% by weight of the polymer composition in order to optimize the final properties of the "masterbatch".

The presence or absence of a dispersant is related to the manufacturing process. As described herein, sometimes a pre-mixing stage of the polymer and the pigment and/or additive in the presence of the dispersant is necessary to obtain sufficient dispersion of the pigment and/or additive in the post-extrusion stage.

The concentrated polymer composition of the present invention will be dosed during the extrusion of the molten polyester polymer forming the fibers.

The rheological effect of the addition of the polymer composition (additive) in the melt is reflected in a reduction in the degree of orientation of the polymer to which the additive is added, which reduction depends on the amount employed.

The spinning systems used to obtain the yarn or fiber from the molten material to which the "masterbatch" of the invention is added are melt spinning systems, since they are synthetic fibers and thermoplastic polymers, in particular polyester polymers.

Yarns or as-spun fibers are generally from the pre-oriented yarn (POY) family and are mainly used to make textured yarns.

The polymer compositions of the invention can be applied to the manufacture of such pre-oriented yarns (POY) with the aim of spinning them at higher speeds, but with a rheological behaviour (load-elongation curve) similar to that when spun at slower speeds without the addition of "masterbatch".

The pre-oriented yarn is a thread collected at a speed of 500m/min to 4500m/min. This yarn has a good two-phase structure (microstructure), with an oriented amorphous phase or mesogenic embedded phase or integrated in a non-oriented matrix, and almost completely no crystalline domains when the spinning speed is not higher than 3500m/min.

In subsequent processing, the orientation of the POY yarns is completed, as in texturing. The production of POY yarn enables an increase in productivity of about 30% and also excellent processing in texturing operations. The POY yarn had a tenacity of about 18CN/tex and an elongation at break of about 150%. The load-elongation curve of the POY yarn globally shows an initial elastic behavior (initial module area) followed by a wide impact area (increase in elongation with hardly any load increase); this area of influence is followed by a reinforced area, which has a linear portion, until the fracture. An interesting parameter of the load-elongation curve of POY yarn relates to the load or force corresponding to 100% elongation. The points corresponding to these coordinates are habitually located in the reinforced area. This load, which results in 100% elongation, can be considered as a global orientation parameter (orientation index, I)₁₀₀). The lower its value, the lower will be the orientation of the fine structure of the yarn and the more deformability (extensibility/stretchability) and the lower its rigidity. Referred to herein as orientation index or I₁₀₀。

When the spinning speed is increased, the elongation at break of the POY yarn decreases and I₁₀₀And (4) increasing. The spinning speed of POY yarns determined for the texturing process is determined by the fact that they must have a certain elongation at break or produce 100% elongation (I) in the POY yarns₁₀₀) The force or load that you must apply.

If the elongation at break of the POY yarn can be increased by addition to the melt of the polymer to be extruded, it will also exhibit I₁₀₀Is reduced. This results in if I₁₀₀Not higher than I corresponding to the spinning speed when molten, non-added polymer is involved₁₀₀There is a possibility of increasing the spinning speed.

The results obtained by applying the polymer composition of the invention clearly demonstrate its effectiveness in overcoming the technical problems that arise in improving the properties during spinning.

The results obtained by dosing a "masterbatch" of a polymer composition containing PMMA as the "carrier" polymer and pigments and/or additives such as those described above demonstrate that these fibres are given elongation or deformation qualities higher than those of a "masterbatch" containing another carrier and the same pigments or additives, and a higher elongation capacity (ductility) than the properties they have under the same extrusion conditions.

In addition to higher regularity in the extrusion process during spinning, yarns obtained using a "masterbatch" with PMMA as the support polymer and additives and/or pigments such as those described above have a fine structure with a lower degree of orientation, enabling the speed of wire collection to be increased, resulting in a much higher productivity (spinning speed) than when using other polymers as the carrier. In this regard, the results show that spinning speed increases of over 20% can be obtained.

The efficacy of the addition of the "masterbatch" of the polymer composition of the invention is confirmed by the fact that: when the concentration of Polymethylmethacrylate (PMMA) in the melt of the produced fiber forming polymer is increased, the obtained effect is also increased, maintaining the spinning speed constant.

In one of the possible embodiments of the invention, the concentrated polymer composition comprises 30 to 50 wt.% of Polymethylmethacrylate (PMMA) as support polymer, 50 to 70 wt.% of PBT, and 1 to 5 wt.% of additives and/or pigments.

This polymer composition is added to fiber and filament forming polymers in an amount of 4 to 8 weight percent and the polymethylmethacrylate is present in the polymer in an amount of 1.6 to 3.2 weight percent.

When the composition is used for spinning at a speed of 2000-4500 m/min, the orientation index of the pre-oriented POY 290/48dtex polyester yarn is reduced to a value of 15.4(cN/tex) to 11.8 (cN/tex).

A preferred embodiment of the present invention is a concentrated polymer composition comprising 60 to 90 wt.% of Polymethylmethacrylate (PMMA) as support polymer and at least additives and/or pigments in an amount of 10 to 40 wt.% of the polymer composition.

Another preferred embodiment of the present invention is a concentrated polymer composition preferably comprising 60 to 80 wt.% of Polymethylmethacrylate (PMMA) as support polymer and 20 to 40 wt.% of carbon black as pigment.

During extrusion, this concentrated polymer composition is added to the molten fiber and filament forming polyester polymer in an amount of 2 to 8 weight percent such that the polymethylmethacrylate is present in the molten fiber and filament forming polymer in an amount of 1.4 to 5.6 weight percent.

This second preferred composition reduces the orientation index of the pre-oriented POY290dtex polyester yarn to values from 11.7(cN/tex) to 8.1(cN/tex) and increases its elongation at break to values from 152% to 186% when spun at speeds from 2000m/min to 4500m/min.

The formulation of the aforementioned "masterbatch" enables the two main ingredients (i.e. pigment and PMMA) to be combined and concentrated to the maximum, enabling the end product to be obtained which provides the best desired function in the fully feasible quantities.

Known alternatives to achieve the same function would include the addition of 2 different masterbatches: one to increase productivity and the other to modify color. In this case the total cost of both masterbatches would be much higher and the total dosage level would be so high that processability and final yarn properties would be affected.

The POY yarn added to this "masterbatch" is subsequently subjected to a texturing process, so that the textured yarn obtained can exhibit an increase in the value of elongation at break of 15% to 35%, thus increasing the spinning productivity by up to 22.3% over the textured polyester yarn without addition.

Another preferred embodiment of the present invention is a concentrated polymer composition comprising 50 to 95 wt.% of Polymethylmethacrylate (PMMA) as a support polymer and 5 to 50 wt.% of titanium dioxide (TiO)₂) As a pigment.

The polymer composition is added to the polyester polymer melt in an amount of 2 to 8 weight percent of the melt, and the polymethylmethacrylate is present in the melt in an amount of 1.7 to 6.8 weight percent.

This third composition enables the orientation index of the pre-oriented yarn POY to be reduced to values from 12.1(cN/tex) to 7.9(cN/tex) and the elongation at break to be increased to values from 152% to 185% when the yarn is spun at speeds from 2000m/min to 4500m/min.

The POY yarn added to this "master batch" is then subjected to a texturing process, which enables the elongation at break of the double textured yarn obtained to be increased by 22% to 37.2%, thus increasing the spinning productivity by up to 22.3% over textured polyester yarn without addition.

The manufacturing method of the master batch comprises the following steps:

another object of the present invention is a process for the manufacture of a "masterbatch" as defined in the present invention, comprising an extrusion stage and optionally a prior premixing stage.

Sometimes this first premixing stage is not necessary for certain polymers, pigments and additives and they can be dosed directly in the extrusion stage.

A premixing stage:

this first stage takes place in a device known as a turbo-mixer or similar, in which the pigments and/or additives are pre-dispersed by using one or more dispersing agents compatible with the base polymer and with the polymer composition of the fibres to be made. To optimize the predispersion, any agglomerates must be mechanically broken up by the blades of the turbine mixer and subsequently soaked or impregnated with the pigment particles. Agglomerates are formed due to the strong interaction between the pigment particles. This phenomenon is particularly present in the case of high concentrations of organic pigments. Soaking is understood as covering a solid surface with a liquid: the dispersant, such as wax, melts and coats the other ingredients in the mixture at the temperatures reached in the turbine mixer.

An extrusion stage:

the main objective of this stage is to obtain good dispersion (dispersed mixture) and homogenization (dispersed mixture) of the "masterbatch" ingredients. There are a variety of extrusion equipment, the choice of which one to use depends on the nature and nature of the product to be extruded. The equipment used in the present invention to manufacture the PMMA based "masterbatch" is a counter rotating twin screw extruder characterized in that its screws rotate in the same direction. The extrusion apparatus delivers a large amount of mechanical energy (shear) to the material so that a large amount of pigments and/or additives can be dispersed. The construction of the screw is necessary in order to guarantee good productivity and optimum product quality. The screw is made up of different assembly elements that distribute, disperse or transport the material according to their geometry and position. The handling of the material during its passage through the extrusion apparatus depends on the configuration of the screw, the type of elements used being of equal importance to the position of the screw. For example, two configurations with the same elements but different distributions in the screw produce extrudates of different quality (dispersion, distribution, color quality). Other external elements affecting extrusion are meters, baths, drying systems and granulators (granulators).

The application method of the master batch comprises the following steps:

the preferred method of application of the "masterbatch" polymer composition of the invention is carried out using the following procedure:

the starting point for melt spinning is a thermoplastic polymer in the form of chips or pellets. They melt in the extruder to form a viscous fluid mass. The dope is dosed by a positive displacement pump to the filtration system and a plate with holes called a spinneret. The molten polymer is passed through the orifices of the spinneret under high pressure to obtain a series of filaments which together form a yarn. The cooling of the dope at the spinneret exit is carried out by a controlled air flow, followed by lubrication of the filaments with a sizing emulsion oil and final winding on a bobbin.

The addition of the "masterbatch" polymer composition of the invention is carried out in the extrusion zone of the molten polymer forming the fibers, either made solid by a gravimetric system or in viscous form by a lateral extruder.

The temperature range used in the extruder during this process is 290 to 300 ℃. This range may vary depending on the size of the extruder, the time the melt is resident therein, and other parameters that may vary from extrusion apparatus to extrusion apparatus.

Description of the drawings:

FIG. 1 shows the variation of the elongation at break and orientation index of the yarn at the same spinning speed (3000m/min) as a function of the amount of masterbatch (15% PMMA in PBT) in the polymer melt to be extruded.

FIG. 2 shows the variation of the orientation index as a function of the PMMA concentration in the polymer melt to be extruded at different spinning speeds.

Figure 3 shows the draw ratio in texturing (residual draw) as a function of orientation index for different elongation at break of the textured yarn.

Fig. 4 shows the variation of the orientation index as a function of the PMMA concentration in the polymer melt to be extruded at two different spinning speeds. In this case, the "masterbatch" is a combination of PMMA and PBT.

FIG. 5 shows the variation of the orientation index as a function of the PMMA concentration in the polymer melt to be extruded, using carbon black as additive at two different spinning speeds.

Figure 6 shows the load/elongation curve of a yarn obtained at 3500m/min speed using carbon black as additive and with or without PMMA as carrier.

Figure 7 shows the load/elongation curves obtained with the same PMMA concentration in two different formulations of polymer composition or "master batch" and polymer matrix (PETRT-20).

FIG. 8 shows the use of PMMA/TiO in various amounts₂Load/elongation curve obtained with "masterbatch".

FIG. 9 shows the change in elongation at break and orientation index as a function of the PMMA concentration (%) in the polyester melt.

FIG. 10 shows the use of PMMA/TiO in various amounts₂Load/elongation curve of textured yarn obtained in "masterbatch".

FIG. 11 shows the use of PMMA/TiO in various amounts₂"masterbatch" is the change in elongation at break as a function of PMMA concentration (%) in the polyester melt.

Fig. 12 shows the load/elongation curves for pre-oriented yarns produced by adding PMMA/carbon black "masterbatch" in two different amounts.

Detailed Description

According to the present invention, a concentrated polymer composition (also referred to in the art as "masterbatch") for adding fibers and/or filaments of a thermoplastic polymer during extrusion is formed from the following ingredients: (a) polymethyl methacrylate (PMMA) with a molecular weight of 100,000g/mol as support ("carrier") polymer, and (b) additives and/or pigments.

The polymer compositions of the invention span a group of PMMA/additive and/or pigment compositions (30/70% to 99/1%) obtaining very satisfactory results, as they enable the orientation index to be reduced and the elongation at break to be increased and thus enable an increased spinning speed to be obtained.

The final concentration of PMMA in the fiber-forming polymer to be extruded can be up to 10% by weight of the final blend (i.e., the "masterbatch" of fibers and/or filaments containing the thermoplastic polymer), concentrations in this range providing the desired results.

The above mentioned results can be seen in fig. 1, where it is clearly seen that for the same spinning speed, the orientation index decreases with increasing concentration of PMMA (which acts as a carrier or support in the "masterbatch" polymer composition). The result is a less oriented yarn (more deformable), allowing higher spinning speeds and at the same time elongation at break as characteristic of the yarn without addition.

The elongation at break, contrary to the case where the orientation index occurs, varies in such a way that: as can be seen from fig. 1, when the concentration of PMMA in the polymer is increased, the elongation at break is also increased, which enables the spinning speed to be increased, resulting in increased productivity.

FIG. 2 relates to the variation of the orientation index as a function of the PMMA concentration in the melt for different spinning speeds. Here, it can be observed that the addition of 3.2% PMMA to the melt during spinning at 3490m/min results in an orientation index (I) of the yarn₁₀₀) The same as when spinning at 3000m/min speed without PMMA, results in increased productivity.

FIG. 3 shows the orientation index (I) with POY yarn for textured yarns with different elongations at break₁₀₀) And a varying residual draw ratio (draw in the deforming operation). Here, it can be observed that for a certain elongation at break of the textured yarn, I₁₀₀The lower the draw ratio that can be applied in the texturing machine. On the other hand, for a certain I₁₀₀The larger the elongation at break of the textured yarn, the lower the residual draw ratio. This is logical because the greater the elongation at break of the textured yarn, the less the orientation (residual draw ratio) is applied in the texturing machine.

Example (b):

example 1:

the polymer composition in pellet or crumb form ("master batch") was added to the polyester melt during extrusion according to the gravimetric addition procedure to obtain the test results provided in table 1 and fig. 4. "masterbatch" comprises 40% by weight of PMMA and 60% by weight of PBT. After the "masterbatch" was added, the mixture was melted in an extruder at 290-300 ℃ and mixed with the molten polymer to form a fluid viscous mass, which was passed through the holes of a spinneret under high pressure to produce filaments, which were collected at 3500m/min to form 290/48dtex POY yarn.

Table 1 contains the orientation index (I) as a function of the percentage of PMMA added to the polymer to be extruded when spinning at speeds of 3000 and 3500m/min₁₀₀) The value of (c). Inspection of them showed that the inclusion of 3.2% PMMA (8% of the "masterbatch") when spun at 3500m/min speed produced the same I as when spun at 3000m/min speed without PMMA₁₀₀The value is obtained.

TABLE 1

Example 2:

the "masterbatch" polymer composition in pellet or crumb form was added to the polyester melt during extrusion according to the gravimetric addition procedure to give the test results provided in table 2. The polymer composition comprises 70 wt.% of PMMA and 30 wt.% of carbon black as an additive. The procedure used to add and obtain the yarn or fiber was the same as described in example 1, finally obtaining a polyester yarn of POY 290/48 dtex.

Table 2 shows the addition of the "masterbatch" to the melt as it is spun at 3000 and 3500m/minOrientation index (I) as a function of the percentage of PMMA in the melt₁₀₀) The value of (c). Here, it can be observed that the presence of 2.1% PMMA when spun at 3500m/min. speed gives the same I as when spun at 3000m/min. speed without PMMA₁₀₀. The values of table 2 are graphically represented in fig. 5.

TABLE 2

When examples 1 and 2 are analysed together, the synergistic effect due to the combined use of PMMA and pigment (carbon black) in the same "masterbatch" can be clearly detected. Comparing the two tables, it can be noted that if the "masterbatch" also contains carbon black, the PMMA content required to maintain the orientation index of the base yarn is reduced from 3.2% to 2.1% when spun at 3000m/min without additives.

The formulation of this "masterbatch" enables the two main ingredients (i.e. pigment and PMMA) to be combined and concentrated to a maximum, achieving a final product that provides all the desired functions in a fully viable amount.

Known alternatives to achieve the same function would include the addition of 2 different masterbatches: one to increase productivity and the other to modify color. In this case, the total cost of both masterbatches would be much higher, and the total dosage level could easily reach 8% or 10%. These levels are generally not feasible because they excessively reduce the percentage of matrix, impairing processability and final properties.

Example 3:

the results shown in table 3 and fig. 6 correspond to tests performed to determine the effect of PMMA on the increased elongation of polyester POY 290/48dtex yarns, in one case using carbon black as pigment and PBT as carrier, and in the other case using PMMA. The spinning speed was kept constant at 3500m/min, as were other extrusion and spinning process conditions.

Both "masterbatches" comprise 70% by weight of support polymer (PMMA or PBT) and 30% of carbon black and are dosed at 4% of the molten polymer to be extruded.

Curves 1 to 3 in FIG. 6 correspond to "masterbatches" comprising 70% PBT/30% carbon black by weight, and curves 4 to 6 correspond to "masterbatches" comprising 70% PMMA/30% carbon black by weight.

It can be observed in table 3 that the presence of PMMA produces significantly greater elongation at break and a much lower orientation index than when PBT is used as a carbon black pigment support. This highlights the much higher efficacy of PMMA to reduce the orientation of the POY polyester yarns.

TABLE 3

Example 4:

POY 210/48dtex polyester yarn was produced at a spinning speed of 3500m/min, one of which was not added, while the other addition had 85% by weight of PMMA/15% by weight of TiO₂Another "masterbatch" with 70 wt% PMMA/30 wt% carbon black added. The two added yarns in both cases contained 2.8% by weight of PMMA relative to the polymer forming the fibers. The other yarn was loaded with a PBT/carbon black weight content of 70 wt.% PBT/30 wt.% carbon black. The spinning process conditions were the same as in example 1.

From the values in table 4, it can again be concluded that the use of PMMA as support for the "masterbatch" leads to higher values of elongation at break and lower orientation indices. It can also be seen that the presence of carbon black in the "masterbatch" has an effect on the traction parameters.

TABLE 4

The results in table 5 correspond to the parameters of the load/elongation curve of POY210dtex yarns produced under the same extrusion conditions at the same speed maintained at 3500m/min. These results are from the load/elongation curves of fig. 7, which correspond to the yarn without addition (RT20) (curves 1.1-1.3), and 2 yarns with addition of 70% PMMA/30% pigment "masterbatch". The pigment used in one case was titanium dioxide (fig. 7, curves 2.1 to 2.6), the pigment used in the other case was carbon black (fig. 7, curves 3.1 to 3.3), and the two added yarns contained 2.8% PMMA relative to the polymer forming the fibers.

Table 5 demonstrates the reduction in fiber orientation when PMMA is used as a "masterbatch" support (I)₁₀₀Reduced), both when the additive used is carbon black and when it is titanium dioxide. This demonstrates the effectiveness of using PMMA as a support for the additive, as it can increase the elongation at break of the polyester POY yarn and thus can increase the spinning speed, meaning improved performance in this operation.

TABLE 5

Example 5:

POY PES standard yarn (RT20) and an additive with a weight content of 85% PMMA/15% TiO₂Comparative study of yarns of "masterbatch".

Polyester POY290dtex is added with different dosage of 85 percent PMMA/15 percent TiO at the spinning speed of 3500m/min₂The "master batch" of (1).

FIG. 8 includesThe load-elongation curves of the POY yarns obtained are shown in the following, wherein curves 1.1 and 1.2 correspond to POY yarns of the PES standard (RT20) and curves 2.1 and 2.2 correspond to POY yarns having a weight content of 85% PMMA/15% TiO₂Is 2% of the amount of "masterbatch", curves 3.1 and 3.2 correspond to 3% of the amount of the same "masterbatch", and curves 4.1 and 4.2 correspond to 4% of the amount of the same "masterbatch".

Table 6 shows the amounts applied to the molten polyester mass to be extruded and the parameters of these curves. Fig. 9 shows the elongation at break and orientation index of these POY yarns as a function of the amount of masterbatch in the molten polymer. It can be clearly seen here that as the concentration of PMMA in the melt increases, the elongation at break increases and the orientation index decreases.

TABLE 6

The POY yarn produced was textured using a draw of 1.8 to obtain a double textured yarn of 340 dtex. The load-elongation curves obtained for these textured yarns by the traction test are shown in FIG. 10, where curves 1-3 correspond to the addition of 2% of the above "masterbatch" (85% PMMA/15% TiO by weight)₂) The yarns of (1) are such that curves 4 to 6 correspond to a 3% dosage of said "masterbatch", and curves 7 to 9 correspond to a 4% dosage of such "masterbatch". Thus, the toughness and elongation at break were calculated and are shown in table 7.

TABLE 7

Amount of masterbatch	Average tenacity (cN/tex)	Average elongation at break(％)
			0％	----	12.3
2％	35.9	22.3
			3％	33.7	28.6
4％	28.6	37.2

FIG. 11 shows the elongation at break of textured yarn as a function of the amount of masterbatch in the melt, revealing that the elongation increases with increasing amount.

It can be seen that the elongation at break of the non-additivated polyester yarn after texturing with a draw ratio of 1.8 is 12.3%, and if the yarn has 2.5% (3% "masterbatch") PMMA, its elongation at break is 28.6%, which is considered to be a normal value in textured polyester yarn. In order for the non-addition textured yarn to exhibit an elongation at break of 28.6%, it was necessary to deform the yarn at a draw ratio of 1.57, which resulted in a final 390 dtex. The possibility of using a stretch ratio of 1.8 instead of 1.57 in the deformation means a 15% increase in productivity.

The calculation was obtained using the following formula:

DR×BREAKAGE LENGTH＝cte.

％△_PROD.＝(DR₁-DR₂)/DR₂×100

wherein:

DR: draw ratio

Breakage LENGTH of 100+ elongation at break

％△_PRODHigh productivity

Thus:

1.8×112.3＝DR₂×128.6；DR₂＝1.57

(1.8-1.57)/1.57×100＝15％

if the concentration of PMMA in the polymer forming the yarn was 3.6% (4% "masterbatch"), the elongation at break would be 37.2% and to achieve this in the non-added yarn would have to be textured at a draw ratio of 1.47 to obtain 416dtex yarn. In this case (3.6% addition of PMMA), this would be a 22.3% increase in productivity.

Example 6:

comparison of two POY polyester yarns, one polymer without added polymer (Standard RT20) and the other polymer with 4% of a "masterbatch" with 70% PBT/30% carbon black by weight.

Two POY polyester 290dtex yarns were prepared at 3500m/min. One of them was made from a standard polymer (RT20) and the other from a polymer supplemented with 4% of a "masterbatch" with a 70% PBT/30% carbon black content by weight. The parameters of the load/elongation curves of these POY yarns are contained in table 8. As mentioned above (table 4), the addition of a "masterbatch" with a weight content of 70% PBT/30% carbon black resulted in a certain elongation at break (higher deformability and stretchability) and also reduced the orientation index of the polyester POY yarn. It should be noted that in this case, the proportion of carbon black in the polymer forming the yarn is 1.2%.

TABLE 8

POY yarn	Average elongation at Break (%)	I100(cN/tex)
			No added PET RT20	134.2	17.0
Adding 4% of master batch	139.7	14.3

To understand how these effects (increased elongation at break and reduced orientation index) can be seen in the properties of the corresponding textured yarns, texturing with a draw ratio of 1.7 resulted in two POY yarns from which 360dtex textured yarns were obtained, the tenacity and elongation at break of which are shown in table 9. The results in table 9 show that decreasing the decreased orientation index of the added POY yarn results in a slightly higher elongation at break of the corresponding textured yarn.

TABLE 9

Precursor POY yarn	Average tenacity (cN/tex)	Elongation at Break (%)
			No added PET RT20	37.1	21.7
Adding 4% of master batch	34.4	23.6

To distinguish the effects of adding "masterbatch" PMMA/carbon black from those that produce PBT/carbon black "masterbatch", polyester POY fibers were made from polymers that were added at different concentrations of "masterbatch" with a content of 70% PMMA/30% carbon black. POY yarns were made using spinning speeds of 3000 and 3500m/min. the melt was added with 3% and 5% of this "masterbatch" and the POY yarns obtained had 290 dtex. Fig. 12 shows the load/elongation curve of POY yarn obtained from spinning at 3500m/min. Here, curves 1 to 3 correspond to yarns to which a "masterbatch" is added in a content of 70% by weight PMMA/30% by weight carbon black and dosed at 3% by weight in the polymer forming the yarn, and curves 4 to 6 correspond to yarns to which the same "masterbatch" is added but dosed at 5% in the polymer forming the yarn. The traction parameters are summarized in table 10.

From the values in the table (which also includes those obtained when spinning at 3000 m/min.) it can be concluded that the addition of a "masterbatch" comprising 70 wt.% PMMA/30 wt.% carbon black to the molten polymer results in a higher elongation at break and a lower orientation index of the corresponding POY yarn. The higher the percentage added, the higher the elongation at break and the lower the orientation index. Furthermore, an increase in spinning speed with the percentage of addition maintained constant means that, as can be expected, the elongation at break decreases and the orientation index increases.

Watch 10

Considering 4% addition of 70% PBT/30% carbon black "masterbatch", spinning at 3500m/min. spinning speed resulted in a break elongation of 139.7% and an orientation index of 14.3CN/tex, it is evident that using PMMA as carbon black support yields better results than using PBT as support (see table 4).

Example 7:

comparative study of the effect of dosing different percentages of a "masterbatch" with a weight content of 70% PMMA/30% carbon black.

Five POY polyester 290dtex yarns were prepared at a spinning speed of 3500m/min. The extruded melts used to make these yarns were characterized by some of them being without additions, another "masterbatch" with 4% additions of 70% PBT/30% carbon black by weight, and the other three "masterbatches" with 3%, 4% and 5% additions of 70% PMMA/30% carbon black by weight, respectively. Table 11 contains the most important traction parameters, which are deduced from the corresponding load-elongation curves (not shown). The values in this table confirm that the presence or addition of carbon black and the use of PBT as a support produce certain advantageous effects on elongation at break (increase) and orientation index (decrease). Most importantly in this example, it can also be seen in table 11 that the greater the concentration of "masterbatch" in the melt, the greater the elongation at break and the lower the orientation index of the corresponding POY yarn. It can also be said that, for the same concentration of carbon black (1.2%), when the presence of carbon black coincides with the presence of PMMA (2.8), there is an increase in the elongation and a decrease in the orientation index.

TABLE 11

Textured yarns were prepared using polyester POY yarns with 5% "masterbatch" added, using a draw ratio of 1.95, to obtain yarns with a tenacity of 30CN/tex and an elongation at break of 25%.

By considering these values, the length at break corresponding to a POY yarn with 5% "masterbatch" added and with a draw ratio of 1.8 would be:

(125×1.95)/1.8＝135％

considering that POY yarn of a standard PES spun at 3500m/min. speed and subsequently textured with a draw ratio of 1.8 exhibits an elongation at break of 12%, for a standard PES with a break length of 135%, the draw ratio would have to be:

(112×1.8)/135＝1.49

therefore, the increased productivity obtained by adding a "masterbatch" of 5% of 70% PMMA/30% carbon black would be:

(1.80-1.49)×100/1.49＝20.8％

in summary, after the tests carried out have been described, it is possible to highlight that PMMA/TiO is used in a weight content of PMMA/TiO₂(TiO₂Matte pigment) resulted in a 22.3% increase in performance, and a 20.8% increase when using a PMMA/carbon black "masterbatch".

Having fully described the invention with reference to the accompanying drawings, it is to be understood that any changes deemed appropriate may be made without departing from the spirit of the invention, which is outlined in the claims below.

Claims (22)

1. A concentrated polymer composition as a "masterbatch" for addition to molten fiber and filament forming polyester polymer during extrusion, characterized in that the polymer composition comprises:

-a support polymer as "carrier", wherein the support polymer comprises at least a polymer from Polymethylmethacrylate (PMMA) having a molecular weight of 10000g/mol to 500000g/mol, representing more than 60 wt% to 99 wt% of the polymer composition; and

-at least one additive and/or pigment, representing from 1% to less than 40% by weight of the polymer composition.

2. The concentrated polymer composition according to claim 1, wherein the pigment is selected from the group consisting of organic pigments, inorganic pigments, or mixtures thereof.

3. The concentrated polymer composition according to claim 2, wherein the selected pigment is carbon black.

4. The concentrated polymer composition of claim 2, wherein the pigment selected is titanium dioxide (TiO)₂)。

5. The concentrated polymer composition according to claim 1, wherein the support polymer comprises one or a combination of at least two of the following polymers in addition to the polymethylmethacrylate: polybutylene terephthalate (PBT), polyethylene terephthalate (PET), polytrimethylene terephthalate (PTT), or polylactic acid (PLA).

6. The concentrated polymer composition according to claim 1, wherein the additive is selected from the group consisting of lubricants, antistatic agents, plasticizers, stabilizers, antioxidants, compatibilizers and flame retardants and mixtures thereof.

7. The concentrated polymer composition according to any one of claims 1 to 3, characterized in that the polymer composition comprises more than 60 to 80 wt. -% of Polymethylmethacrylate (PMMA) as support polymer and 20 to less than 40 wt. -% of carbon black as pigment.

8. According toThe concentrated polymer composition according to any one of claims 1 to 3, wherein the polymer composition comprises more than 60 to 95 wt.% of Polymethylmethacrylate (PMMA) as a support polymer and 5 to less than 40 wt.% of titanium dioxide (TiO)₂) As a pigment.

9. The concentrated polymer composition according to any one of claims 1 to 6, wherein the composition further comprises a dispersant.

10. A process for the manufacture of a concentrated polymer composition as a "masterbatch" according to any one of claims 1 to 9, characterized in that it comprises an extrusion stage and optionally a previous premixing stage.

11. The manufacturing process according to claim 10, characterized in that the extrusion stage uses an extrusion mixer, preferably a counter-rotating twin-screw extruder, which delivers a large amount of mechanical energy and enables a large amount of pigments and/or additives to be dispersed, to obtain a good dispersion and homogenization of the "masterbatch" ingredients, wherein the screws consist of different assembled elements which distribute, disperse or transport the material according to their geometry and position.

12. A manufacturing process according to claim 10, characterized in that, in an optional premixing stage, the pigments and/or additives are pre-dispersed by using one or more dispersants compatible with the base polymer and the polymer components of the fibers to be manufactured, wherein all agglomerates are mechanically broken up by the blades of a turbine mixer and subsequent soaking or impregnation of the pigment particles.

13. Use of the concentrated polymer composition according to any of claims 1 to 9, wherein the composition is added to a molten polyester polymer, wherein the polyester is selected from the group consisting of polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polytrimethylene terephthalate (PTT) or polylactic acid (PLA) and the concentrated polymer composition is added to the melt in a proportion such that the final concentration of Polymethylmethacrylate (PMMA) in the melt is at most 10 wt.%.

14. Use of the concentrated polymer composition according to claim 13, characterized in that the addition of the concentrated polymeric composition results in an increase of 40% +/-10% in elongation at break when spinning and an orientation index I when spinning at a speed of 2000m/min₁₀₀The reduction of 10cN/tex +/-5cN/tex increases the picking speed and efficiency of the spinning process by over 20%.

15. Use of the concentrated polymer composition of any one of claims 1 to 9 for the manufacture of an oriented yarn spun at a speed of from 500m/min.

16. Use of the concentrated polymer composition according to claim 15 for the manufacture of oriented yarn spun at a speed of 2000m/min.

17. Use of a concentrated polymer composition according to claim 7, wherein the polymer composition is added to a melt of a fibre and filament forming polyester polymer in an amount of from 2 to 8% by weight and the polymethylmethacrylate is present in an amount of from 1.4 to 5.6% by weight of the melt.

18. Use of the concentrated polymer composition according to claim 17, characterized in that the composition reduces the orientation index of the pre-oriented polyester yarn to a value of 11.7(cN/tex) to 8.1(cN/tex) when spinning at a speed of 2000m/min.

19. Use of a concentrated polymer composition according to claim 8, wherein the polymer composition is added to a melt of a fibre and filament forming polyester polymer in an amount of from 2 to 8% by weight and the polymethylmethacrylate is present in an amount of from 1.7 to 6.8% by weight of the melt.

20. Use of the concentrated polymer composition according to claim 19, characterized in that the composition reduces the orientation index of the pre-oriented polyester yarn to a value of 12.1(cN/tex) to 7.9(cN/tex) when spun at a speed of 2000m/min.

21. Use of a concentrated polymer composition according to any of claims 1 to 9, characterized in that the composition is added in the form of solid pellets in the extrusion zone of the molten polymer forming the fibres by means of a gravimetric system with or without a mixer.

22. Use of a concentrated polymer composition according to any of claims 1 to 9 wherein the composition is added in molten form through a side extruder in the extrusion zone of the molten polymer forming the fibres.