WO2021176411A1

WO2021176411A1 - Bcf yarns including pet and pbt

Info

Publication number: WO2021176411A1
Application number: PCT/IB2021/051855
Authority: WO
Inventors: Anand VISWANATH; Subhash Chand
Original assignee: Invista Textiles (U.K.) Limited; Inv Performance Surfaces, Llc
Priority date: 2020-03-06
Filing date: 2021-03-05
Publication date: 2021-09-10

Abstract

A bulked continuous filament (BCF) yarn includes a homogeneous polymer blend. The homogeneous polymer blend includes a polyester blend and/or a reaction product of the polyester blend. The polyester blend includes polyethylene terephthalate (PET) or co-PET. The PET, co-PET, or a combination thereof is 1 wt% to 50 wt% of a total weight of polyesters in the polyester blend. The polyester blend also includes polybutylene terephthalate (PBT). The PBT is 50 wt% to 99 wt% of the total weight of polyesters in the polyester blend.

Description

BCF YARNS INCLUDING PET AND PBT

CROSS-REFERENCE TO RELATED APPLICATION [0001] This application claims the benefit of priority to U.S. Provisional Patent

Application Serial No. 62/985,895 filed March 6, 2020, the disclosure of which is incorporated herein in its entirety by reference.

BACKGROUND

[0002] Nylon-6,6 is an excellent carpet fiber, and is also the second-most expensive commonly used carpet fiber (with wool being the most expensive). Properly maintained, a well- made nylon-6,6 carpet will far outlast most homeowners’ fashion preferences, with styles changing before the carpet wears out.

[0003] Poly(ethylene) terephthalate (PET) can also be used to make attractive and long- lasting carpet, and also has the benefit of inherent resistance to many stains. PET exhibits lower resistance to mechanical crush over time. Thus, in high-traffic areas, “rivers” or ruts can be observed over time, resulting from flattening down of face yarns (tufts).

[0004] Poly(butylene) terephthalate (PBT) exhibits some crush resistance; however, PBT carpet has suffered two shortcomings. First, its cost is well above PET, and close to that of nylon-6,6. Second, while its crush resistance rivals that of some polyamides, it tends to exhibit poor tuft definition over time. Instead of showing a crisp pattern as produced, with time the PBT carpets show poor tuft definition. This may result from a minor amount of untwisting or unraveling at the top (visible) end of the tufted carpet yarns (e.g., poor tuft definition during use; tuft definition is also referred to as tip definition). The maintenance of tip definition of the tufted carpet yarns is highly desired from an aesthetic point of view.

SUMMARY OF THE INVENTION

[0005] In various aspects, the present invention provides a bulked continuous filament

(BCF) carpet yarn. The carpet yarn includes a homogeneous polymer blend. The homogeneous polymer blend includes a polyester blend and/or a reaction product of the polyester blend. The polyester blend includes polyethylene terephthalate (PET) or co-PET. The PET, co-PET, or a combination thereof is 1 wt% to 50 wt% of a total weight of polyesters in the polyester blend. The polyester blend also includes polybutylene terephthalate (PBT). The PBT is 50 wt% to 99 wt% of the total weight of polyesters in the polyester blend.

[0006] In various aspects, the present invention provides a carpet including a BCF carpet yarn. The carpet yarn includes a homogeneous polymer blend. The homogeneous polymer blend includes a polyester blend and/or a reaction product of the polyester blend. The polyester blend includes polyethylene terephthalate (PET) or co-PET. The PET, co-PET, or a combination thereof is 1 wt% to 50 wt% of a total weight of polyesters in the polyester blend. The polyester blend also includes polybutylene terephthalate (PBT). The PBT is 50 wt% to 99 wt% of the total weight of polyesters in the polyester blend.

[0007] In various aspects, the present invention provides a BCF carpet yarn. The carpet yarn includes a homogeneous polymer blend that is 90 wt% or more of the carpet yarn. The homogeneous polymer blend includes a polyester blend and/or a reaction product of the polyester blend. The polyester blend includes polyethylene terephthalate (PET) or co-PET. The PET, co-PET, or a combination thereof is 5 wt% to 40 wt% of a total weight of polyesters in the polyester blend. The polyester blend also includes polybutylene terephthalate (PBT). The PBT is 60 wt% to 95 wt% of the total weight of polyesters in the polyester blend. The PET, co-PET, or combination thereof is present in the polyester blend in an amount sufficient to reduce a peak melting point in the homogeneous polymer blend of the PBT without creating a separate PET/co- PET peak melting point in the range of 225 °C to 255 °C in a DSC scan.

[0008] In various aspects, the present invention provides a carpet. The carpet includes a

BCF yarn. The BCF yarn includes a homogeneous polymer blend that is 90 wt% or more of the carpet yarn. The homogeneous polymer blend includes a polyester blend and/or a reaction product of the polyester blend. The polyester blend includes polyethylene terephthalate (PET) or co-PET. The PET, co-PET, or a combination thereof is 5 wt% to 30 wt% of a total weight of polyesters in the polyester blend. The polyester blend also includes polybutylene terephthalate (PBT). The PBT is 70 wt% to 95 wt% of the total weight of polyesters in the polyester blend. The carpet has equal or better durability, tuft definition, or a combination thereof, than a corresponding carpet having 100 wt% PBT yarn in place of the carpet yarn, as determined by: Vetterman Drum test, measured according to ASTM D5417-93; or Hexapod Drum test, measured according to ASTM D5252; or Chair caster test, measured according to ASTM D6962; or Walk test, measured according to ASTM D6119, or a combination thereof.

[0009] Various embodiments of the present invention provide advantages over other yarns and carpets formed therefrom. For example, in various embodiments, the yarn of the present invention exhibits both good tuft definition as well as good crush resistance. In various embodiments, the yarn of the present invention has a crush resistance comparable (e.g., approximately equal) to that of yarns formed of unblended polyamides or PBT, while avoiding the problems of poor tuft definition that occur with yarns formed of unblended PBT. In an embodiment, the disclosed yarn can be tufted into carpet that maintains tuft definition over time better than like carpet comprising 100 wt% PBT yarn. In various embodiments, the yarn of the present invention exhibits superior tuft definition, crush resistance, or a combination thereof, as compared to the weighted average of the corresponding properties of PBT and PET based on the blend ratio used.

BRIEF DESCRIPTION OF THE FIGURES [0010] The drawings illustrate generally, by way of example, but not by way of limitation, various aspects of the present invention.

[0011] FIG. 1 illustrates differential scanning calorimetry (DSC) scans of bulked continuous filament (BCF) yarns formed from polybutylene terephthalate (PBT) and various blends of PBT and polyethylene terephthalate (PET), in accordance with various aspects.

DETAILED DESCRIPTION OF THE INVENTION [0012] Reference will now be made in detail to certain aspects of the disclosed subject matter, examples of which are illustrated in part in the accompanying drawings. While the disclosed subject matter will be described in conjunction with the enumerated claims, it will be understood that the exemplified subject matter is not intended to limit the claims to the disclosed subject matter.

[0013] Throughout this document, values expressed in a range format should be interpreted in a flexible manner to include not only the numerical values explicitly recited as the limits of the range, but also to include all the individual numerical values or sub-ranges encompassed within that range as if each numerical value and sub-range is explicitly recited. For example, a range of “about 0.1% to about 5%” or “about 0.1% to 5%” should be interpreted to include not just about 0.1% to about 5%, but also the individual values (e.g., 1%, 2%, 3%, and 4%) and the sub-ranges (e.g., 0.1% to 0.5%, 1.1% to 2.2%, 3.3% to 4.4%) within the indicated range. The statement “about X to Y” has the same meaning as “about X to about Y,” unless indicated otherwise. Likewise, the statement “about X, Y, or about Z” has the same meaning as “about X, about Y, or about Z,” unless indicated otherwise.

[0014] In this document, the terms “a,” “an,” or “the” are used to include one or more than one unless the context clearly dictates otherwise. The term “or” is used to refer to a nonexclusive “or” unless otherwise indicated. The statement “at least one of A and B” or “at least one of A or B” has the same meaning as “A, B, or A and B.” In addition, it is to be understood that the phraseology or terminology employed herein, and not otherwise defined, is for the purpose of description only and not of limitation. Any use of section headings is intended to aid reading of the document and is not to be interpreted as limiting; information that is relevant to a section heading may occur within or outside of that particular section.

[0015] In the methods described herein, the acts can be carried out in any order without departing from the principles of the invention, except when a temporal or operational sequence is explicitly recited. Furthermore, specified acts can be carried out concurrently unless explicit claim language recites that they be carried out separately. For example, a claimed act of doing X and a claimed act of doing Y can be conducted simultaneously within a single operation, and the resulting process will fall within the literal scope of the claimed process.

[0016] The term “about” as used herein can allow for a degree of variability in a value or range, for example, within 10%, within 5%, or within 1% of a stated value or of a stated limit of a range, and includes the exact stated value or range.

[0017] The term “substantially” as used herein refers to a majority of, or mostly, as in at least about 50%, 60%, 70%, 80%, 90%, 95%, 96%, 97%, 98%, 99%, 99.5%, 99.9%, 99.99%, or at least about 99.999% or more, or 100%. The term “substantially free of’ as used herein can mean having none or having a trivial amount of, such that the amount of material present does not affect the material properties of the composition including the material, such that about 0 wt% to about 5 wt% of the composition is the material, or about 0 wt% to about 1 wt%, or about 5 wt% or less, or less than, equal to, or greater than about 4.5 wt%, 4, 3.5, 3, 2.5, 2, 1.5, 1, 0.9, 0.8, 0.7, 0.6, 0.5, 0.4, 0.3, 0.2, 0.1, 0.01, or about 0.001 wt% or less, or about 0 wt%. [0018] As used herein, the term “polymer” refers to a molecule having at least one repeating unit and can include copolymers.

[0019] As used herein, the term “fiber” refers to filamentous material that can be used in fabric and yarn as well as textile fabrication. One or more fibers can be used to produce a fabric or yarn.

[0020] As used herein, the term “yarn” refers to a length of interlocked or bound filaments or fibers. A yarn can include two or more yarns that have been plied, twisted, or folded together, and can be heat-set.

[0021] As used herein, the term “bulked continuous fiber” refers to yarn including one or more single yarns each independently formed from a continuous filament.

Carpet yarn

[0022] In various aspects, the present invention provides a bulked continuous filament

(BCF) carpet yarn. The carpet yarn includes filaments that include a homogeneous polymer blend. The homogeneous polymer blend includes a polyester blend and/or a reaction product of the polyester blend. The polyester blend includes polyethylene terephthalate (PET) or co-PET. The PET, co-PET, or a combination thereof can be 1 wt% to 50 wt% of a total weight of polyesters in the polyester blend. The polyester blend also includes polybutylene terephthalate (PBT). The PBT can be 50 wt% to 99 wt% of the total weight of polyesters in the polyester blend.

[0023] The BCF yarn can be formed in any suitable way. In various aspects, the present invention provides a method of forming the fiber or carpet yarn described herein. For example, a continuous filament or fiber that is formed from the homogeneous polymer blend can be formed by a suitable process, such as melt-spinning, and a single yarn can be formed from the continuous filament or fiber. The filament or fiber can have any suitable cross-section, such as round, ovular, irregular, or including lobes (e.g., trilobal). The single yarn can include any suitable number of filaments formed from the continuous filament. The single yarns can be plied or twisted together (e.g., two, three, or four or more single yarns) to form the carpet yarn. The carpet yarn can be heat-set.

[0024] The homogeneous polymer blend can be any suitable proportion of the carpet yarn (e.g., of the filaments of the carpet yarn), such as 90 wt% to 100 wt% of the carpet yarn, or 90 wt% or more, or less than, equal to, or greater than 91 wt%, 92, 93, 94, 95, 96, 97, 98, 99, 99.5, 99.9 wt%, or 99.99 wt% or more. The total weight of polyesters can be any suitable proportion of the carpet yarn (e.g., of the filaments of the carpet yarn), such as 90 wt% to 100 wt% of the carpet yarn, or 90 wt% or more, or less than, equal to, or greater than 91 wt%, 92, 93, 94, 95, 96, 97, 98, 99, 99.5, 99.9 wt%, or 99.99 wt% or more. The polyester blend and/or the reaction product of the polyester blend can together form any suitable proportion of the carpet yarn (e.g., of the filaments of the carpet yarn), such as 90 wt% to 100 wt% of the carpet yarn, or 90 wt% or more, or less than, equal to, or greater than 91 wt%, 92, 93, 94, 95, 96, 97, 98, 99, 99.5, 99.9 wt%, or 99.99 wt% or more.

[0025] The homogeneous polymer blend includes a polyester blend, a reaction product of the polyester blend, or a combination thereof. The reaction product can be the product that results from heating the polyester blend without adding any additional materials thereto. The homogeneous polymer blend can include the polyester blend. The homogeneous polymer blend can include the reaction product of the polyester blend, such as a transesterification product of the polyester blend. The homogeneous polymer blend and/or the carpet yarn can be free of reaction products of the polyester blend, such as free of transesterification products of the polyester blend. The homogeneous polymer blend and/or the carpet yarn can be free of non- transesterified polyester blend. The homogeneous polymer blend can include any suitable proportion of the polyester blend and the reaction product thereof. For example, the polyester blend can be 0.001 wt% to 100 wt% of the homogeneous polymer blend, or 20 wt% to 100 wt%, or 50 wt% to 100 wt%, or 80 wt% to 100 wt%. The reaction product of the polyester blend (e.g., transesterification products) can be 0.001 to 100 wt% of the homogeneous polymer blend, or 0.001 wt% to 20 wt%, or 0.001 wt% to 50 wt%, or 0.001 wt% to 80 wt%, or greater than, less than, or equal to about 0.001 wt%, 1, 2, 4, 6, 8, 10, 20, 30, 40, 50, 60, 70, 80, 90, 92, 94, 96, 98, 99, 99.9, 99.99, or 99.999 wt%.

[0026] The homogeneous polymer blend can include a homogeneous blend of the polyester blend and/or reaction product thereof. The polymers of the homogenous polymer blend can be homogeneously distributed; for example, the polyesters of the homogeneous polymer blend can be homogeneously distributed. The homogeneous polymer blend can be substantially free of heterogeneously distributed polymer, and can include homogeneously and/or heterogenerously distributed non-polymeric materials. The homogeneous polymer blend can be a single continuous polymer phase that is free of dispersed (i.e., discontinuous) polymer phases therein or thereon, such as free of dispersed phases of PET, co-PET, PBT, or reaction products thereof. The homogeneous polymer blend can be free of dispersed phases of PET. Dispersed polymer phases can be less than 5 wt% of the homogeneous polymer blend, or less than 4 wt%, 3.5, 3, 2.5, 2, 1.5, 1, 1.5, 0.1, less than 0.01 wt%, or 0 wt% of the homogeneous polymer blend.

[0027] The polyester blend can include any one or more suitable polyesters in addition to the PET, co-PET, and/or PBT. The PET, co-PET, and the PBT, can be the only polyesters in the polyester blend. The PET, co-PET, and the PBT can be the only synthetic polymers in the polyester blend. The polyester blend can include polypropylene terephthalate). The polyester blend can be free of polypropylene terephthalate).

[0028] The PET, co-PET, or a combination thereof can be 1 wt% to 50 wt% of a total weight of polyesters in the polyester blend, or 2 wt% to 40 wt%, or 5 wt% to 40 wt%, or 5 wt% to 30 wt%, or 1 wt% or more, or less than, equal to, or greater than 2, 3, 4, 5, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 34, 36, 38, 40, 42, 44, 46, 48 wt%, or 50 wt% or less. The PBT can be 50 wt% to 99 wt% of the total weight of polyesters in the polyester blend, or 60 wt% to 98 wt%, or 60 wt% to 95 wt%, or 70 wt% to 95 wt%, or 50 wt% or more, or less than, equal to, or greater than 52, 54, 56, 58, 60, 62, 64, 66, 68, 70, 72, 74, 76, 78, 80, 82, 84, 86, 88, 90, 92, 94, 95, 96, 97, 98 wt%, or 99 wt% or less.

[0029] The PET, co-PET, or the combination thereof can be 2 wt% to 40 wt% of the total weight of polyesters in the polyester blend, and the PBT can be 60 wt% to 98 wt% of the total weight of polyesters in the polyester blend. The PET, co-PET, or the combination thereof can be 5 wt% to 40 wt% of the total weight of polyesters in the polyester blend, and the PBT can be 60 wt% to 95 wt% of the total weight of polyesters in the polyester blend. The PET, co-PET, or the combination thereof can be 5 wt% to 30 wt% of the total weight of polyesters in the polyester blend, and the PBT can be 70 wt% to 95 wt% of the total weight of polyesters in the polyester blend. The PET, co-PET, or the combination thereof can be 7 wt% to 30 wt% of the total weight of polyesters in the polyester blend, and the PBT can be 70 wt% to 93 wt% of the total weight of polyesters in the polyester blend. The PET, co-PET, or combination thereof can be present in the polyester blend in an amount sufficient to reduce in the homogeneous polymer blend a peak melting point of the PBT without creating a separate PET/co-PET peak melting point in the range of 225 °C to 255 °C in a DSC scan.

[0030] The PET can be any suitable PET. The PET can be a PET homopolymer or a

PET co-polymer (co-PET). For example, the co-PET can be a PET copolymer including isophathalic acid that is 5 wt% or less of the co-PET (e.g., 4 wt% or less, 3, 2, or 1 wt% or less). The PET, co-PET, or combination thereof can have any suitable intrinsic viscosity, such as 0.40 dL/g to 1.5 dL/g, 0.6 dL/g to 1.10 dL/g, 0.70 dL/g to 1.00 dL/g, or 0.40 dL/g or less, or less than, equal to, or greater than 0.5 dL/g, 0.6, 0.65, 0.7, 0.75, 0.8, 0.85, 0.9, 0.95, 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9 dL/g, or 2.0 dL/g or less.

[0031] The PBT can be any suitable PBT. The PBT can have an intrinsic viscosity of

0.70 dL/g to 1.5 dL/g, or 1.1 dL/g to 1.5 dL/g, or 1.2 dL/g to 1.5 dL/g, or 0.70 dL/g or more, or less than, equal to, or greater than 0.8 dL/g, 0.9, 1.0, 1.1, 1.15, 1.2, 1.21, 1.22, 1.23, 1.24, 1.25, 1.26, 1.27, 1.28, 1.29, 1.3, 1.35, 1.4 dL/g, or 1.45 dL/g or less. A higher intrinsic viscosity (e.g., greater than 0.7 dL/g, or greater than 1.1 dL/g, or greater than 1.2 dL/g) can provide better fiber durability performance. The PBT can have a viscosity number of 107 cm³/g to 180 cm³/g, or 140 cm³/g to 180 cm³/g, or 107 cm³/g or more, or less than, equal to, or greater than 110 cm³/g, 115, 120, 125, 130, 135, 140, 145, 150, 155, 160, 165, 170, 175 cm³/g, or 180 cm³/g or less. [0032] The homogeneous polymer blend can be free of or can include one or more polymer modifiers. The one or more polymer modifiers can be 2 wt% or less of the homogeneous polymer blend, such as less than 1.8 wt%, 1.6, 1.4, 1.2, 1.0, 0.8, 0.6, 0.5, 0.4, 0.3, 0.2 wt%, or less than 0.1 wt%. The one or more polymer modifiers can be any suitable polymer modifiers. The polymer modifier can include a nucleating agent, lubricant (e.g., pentaerythritol tetrastearate), slip additive, or a combination thereof.

[0033] The homogeneous polymer blend can be free of or can include one or more functional additives for carpet yarns. The one or more functional additives can include any suitable functional additive. The one or more functional additives can include a flame-retardant additive, a stain-resistant additive, or a combination thereof.

[0034] The homogeneous polymer blend can be free of or include one or more carpet yarn pigments. The one or more carpet pigments can be any suitable carpet pigments, such as dyes or pigments. The one or more carpet yarn pigments can include TiCh. [0035] The homogeneous polymer blend can be free of or include one or more compatibilizers or chain extenders for PET and PBT. The one or more compatibilizers can be any suitable compatibilizers. The one or more compatibilizers can include a linear polyester chain extender. The homogeneous polymer blend can be free of or include maleic anhydride- grafted polymers/copolymers and/or maleic anhydride copolymers, such as maleic anhydride- grafted polyethylene polymers/copolymers and maleic anhydride/polyethylene copolymers. The homogeneous polymer blend can be free of or include as maleic anhydride-grafted polypropylene, maleic-anhydride-grafted ethylene-octene copolymer, and/or styrene-maleic anhydride copolymers.

[0036] The homogeneous polymer blend can be free of or include dispersing agents and/or surfactants. The homogeneous polymer blend can be free of or include stearates, such as stearate salts, such as calcium stearate and zinc stearate. The homogeneous polymer blend can be free of or include waxes, such as polyethylene waxes.

[0037] The homogeneous polymer blend can be free of or include transesterification inhibitors, such as organophosphorous compounds. The homogeneous polymer blend can be free of or include organophosphates and/or organophosphites, such as triphenyl phosphite, octadecyl phosphite, triphenyl phosphate, dioctadecyl phosphate, diphenyl phosphate, dibenzyl phosphate, decyldiphenyl phosphate, phosphoric acid, phosphate ester, sodium dihydrogen phosphate, or hydrogen phosphates of zinc or calcium. The homogeneous polymer blend can be free of or include silica.

[0038] The homogeneous polymer blend can include talc, or can be substantially free of talc. The homogeneous polymer blend can be 0 wt% to 3 wt% talc, or less than 3 wt% talc, or 0 wt% to 2 wt% talc, or 0 wt% to 1 wt% talc.

[0039] The homogeneous polymer blend can include or be free of a transesterification promoter and/or transesterification catalyst, such as an alkali metal carbonate salt, alkali earth metal carbonate salt, alkali metal bicarbonate salt, or alikali earth metal bicarbonate salt, such as sodium carbonate or potassium carbonate. The transesterification promoter and/or transesterification catalyst can be 0 wt% of the homogeneous polymer blend, or 0.1 wt% to 5 wt%, or 0.5 wt% to 2 wt%, or 0.5 wt% to 1 wt%.

[0040] Evidence of transesterification can include lower melting point, lower processing temperature, higher melt flowability and/or lower crystallinity temperature. [0041] The homogeneous polymer blend can be formed using any suitable method. The method of forming the homogeneous polymer blend can include the use of a masterbatch, or can be free of the use of masterbatches.

Carpet.

[0042] In various aspects, the present invention provides a carpet that includes the carpet yarn described herein. For example, the carpet can include a BCF carpet yarn. The carpet yarn includes filaments that include a homogeneous polymer blend. The homogeneous polymer blend includes a polyester blend and/or a reaction product of the polyester blend. The polyester blend includes polyethylene terephthalate (PET) or co-PET. The PET, co-PET, or a combination thereof can be 1 wt% to 50 wt% of a total weight of polyesters in the polyester blend. The polyester blend also includes polybutylene terephthalate (PBT). The PBT can be 50 wt% to 99 wt% of the total weight of polyesters in the polyester blend. The PET, co-PET, or combination thereof can be present in the polyester blend in an amount sufficient to reduce in the homogeneous polymer blend a peak melting point of the PBT without creating a separate PET/co-PET peak melting point in the range of 225 °C to 255 °C in a DSC scan. Any suitable proportion of carpet fibers in the carpet can be the carpet yarn of the present invention, such as 1 wt% to 100 wt%, or 50 wt% to 100 wt%, or 90 wt% to 100 wt%.

[0043] The carpet can have equal or better durability, equal or better tuft definition, or a combination thereof, as compared to other carpets, such as carpets including 100 wt% PBT yarn in place of the carpet yarn of the present invention, or such as carpets including BCF yarns including dispersed polymer phases of PET, co-PET, PBT, and/or reaction products thereof in place of the homogeneous polymer blend of the carpet yard of the present invention. For example, the carpet can have equal or better durability than a corresponding carpet having 100 wt% PBT yarn in place of the carpet yarn. The carpet can have equal or better tuft definition than a corresponding carpet having 100 wt% PBT yarn in place of the carpet yarn. The carpet can have equal or better durability and tuft definition than a corresponding carpet having 100 wt% PBT yarn in place of the carpet yarn. Durability or tuft definition can be determined by Vetterman Drum test, measured according to ASTM D5417-93; or Hexapod Drum test, measured according to ASTM D5252; or Chair caster test, measured according to ASTM D6962; or Walk test, measured according to ASTM D6119; or a combination thereof. Examples

[0044] Various aspects of the present invention can be better understood by reference to the following Examples which are offered by way of illustration. The present invention is not limited to the Examples given herein.

[0045] PBT was sourced from BASF as Ultradur ^H B6550 (intrinsic viscosity of ~1.26 dL/g). PET was obtained from Indorama under Auriga 8912 (intrinsic viscosity of 0.83 dL/g). [0046] Carpet durability was evaluated based on procedures described in the Vetterman

Drum Texture Retention Test (ASTM D5417-93). The 5K Rating means the samples are subjected to a 5,000 cycle test according to ASTM D5417-93. Yarn surface appearance was also graded following impact testing on the carpets via a hexapod ball (ASTM D5252) and a chair castor (ASTM D6962).

[0047] The tuft definition grading system was designed to delineate the tip definition behavior from matting following durability testing.

[0048] DSC refers to differential calorimetry, a measurement of the amount of heat either consumed or emitted by a sample as it is heated or cooled, and is an indication of melting point, crystallinity and purity of polymers. For DSC testing, samples were tested via the following method: 10 mg of the sample was weighed for the testing. For the DSC test method, samples were subjected to 2 cycles of heating followed by cooling. Samples were subjected to hold at 25 °C for 1 min, followed by a 20 °C/min ramp to 290 °C, isothermal for 1 min and then cooled from 290-25 °C at 20 °C/min..Tm and T_c were identified for each sample using the peaks for theheating/cooling cycle. The heats of melting, AHm, and cold crystallization, A He, were determined by integration of the areas (J/g) under the peaks. The percent crystallinity was then determined using the following equation: % Crystallinity = [AHm - AHc] / AHm · 100%. The AHm is a reference value and represents the heat of melting if the polymer were 100% crystalline (per PerkinElmer, Application Note, DSC as a problem solving tool: Measurement of Percent Crystallinity in Thermoplastics).

Example 1.

[0049] Bulked continuous filament (BCF) yarn was formed by melt spinning single yarns of 1000 denier, 80 filaments, 0.3% TiCh and trilobal cross-section with modification ratio 2.20 +/- 0.20. Two single yarns were plied and twisted together at 5.75 turns per inch (per 2.54 cm). Twisted yarn was heat set at 290 °F (143.3 °C) in a Superba heat setting machine. The finished yarn was 12 denier per filament.

[0050] The heat set yarn was tufted into residential cut pile carpet with 45 oz/sq. yd.

(1.5258 kg/m²) face weight and 5/8” inch (1.5875 cm) pile height on l/8^th gauge tufting machine. The carpet was dyed in wool beige color using disperse dyes. Table 1 indicates the yarn composition used and the durability properties of the carpet formed.

[0051] Table 1. Yarn composition and durability properties of the carpet formed therefrom. PBT is polybutylene terephthalate. PET is polyethylene terephthalate. NA means not available.

[0052] As seen in Table 1, the majority PBT blends of 90% and 80% PBT maintained durability as measured by Vetterman (5K cycles), chair castor (3K cycles) and hexapod (8K cycles) equivalent to that of 100% PBT. At the 60% PBT loading, a decrease in performance was observed, especially in the Vetterman testing.

[0053] Table 2 illustrates the tuft definition grade after the chair castor test, with 1 indicating a poor, fuzzy appearance, and with 5 indicating great tuft definition. It was observed that with the 100% PBT, there was some difficulty in obtaining good tuft definition in the carpets made following the heat setting, as the carpet looked fuzzy and some of the crispness of well- defined tufts was diminished. This was likely due to high crystallinity of PBT yarns which resulted in poor heat-settability of the twisted yarn. With the PBT/PET blends, this problem was not observed in the carpets — high tuft definition was maintained. In the chair castor test, this was especially observed where the 100% PBT completely lost all tuft definition, while the PBT/PET blends maintained tuft integrity following the chair castor testing. This suggests that this benefit is added primarily through the addition of PET. The decrease in PBT’s crystallization behavior caused by the addition of PET produced a carpet with improved durability and appearance characteristics. [0054] Table 2. Tuft definition grade visual assessment (scale of 1 to 5) after chair castor testing.

[0055] Table 3 illustrates T_m, T_c, and percent crystallinity of the heat-set twisted BCF yarns, as determined via differential scanning calorimetry (DSC). FIG. 1 illustrates DSC plots of the heat-set twisted BCF yarns (8440 yarns). As seen in the melt points of the 100% PBT versus the blends, there was a gradual corresponding decrease in the peak melting points with increasing amounts of the PET. This suggested good mixing of both the PET and PBT materials in the blend. Furthermore, the crystallization temperature (T_c) seen in the DSC (lower section of graph in FIG. 1) also displays a corresponding decrease with the blends. The 100% PBT showed a Tc of 192 °C, and the blends having 10%, 20%, and 40% PET had T_c’s of 187 °C, 180 °C, and 160 °C, respectively. The % crystallinity was reduced with the increase in wt% PET. The decrease in both % crystallinity and T_c enabled an improved capability to maintain the tuft definition of the carpet, especially with the heat setting process applied to the yarns. The lowering of the % crystallinity and T_c in the blends likely caused or contributed to the improved tuft definition observed in these carpet products, which was observed even after durability testing.

[0056] Table 3. T_m, T_c, and percent crystallinity.

[0057] The terms and expressions that have been employed are used as terms of description and not of limitation, and there is no intention in the use of such terms and expressions of excluding any equivalents of the features shown and described or portions thereof, but it is recognized that various modifications are possible within the scope of the embodiments of the present invention. Thus, it should be understood that although the present invention has been specifically disclosed by specific embodiments and optional features, modification and variation of the concepts herein disclosed may be resorted to by those of ordinary skill in the art, and that such modifications and variations are considered to be within the scope of embodiments of the present invention.

Exemplary Embodiments.

[0058] The following exemplary embodiments are provided, the numbering of which is not to be construed as designating levels of importance:

[0059] Embodiment 1 provides a bulked continuous filament (BCF) carpet yarn comprising: a homogeneous polymer blend comprising a polyester blend and/or a reaction product thereof, the polyester blend comprising polyethylene terephthalate (PET) or co-PET, wherein the PET, co-PET, or a combination thereof is 1 wt% to 50 wt% of a total weight of polyesters in the homogeneous polymer blend; and poly butylene terephthalate (PBT), wherein the PBT is 50 wt% to 99 wt% of the total weight of polyesters in the homogeneous polymer blend.

[0060] Embodiment 2 provides the carpet yarn of claim 1 , wherein the homogeneous polymer blend comprises the polyester blend.

[0061] Embodiment 3 provides the carpet yarn of any one of Embodiments 1-2, wherein the homogeneous polymer blend comprises the reaction product of the polyester blend.

[0062] Embodiment 4 provides the carpet yarn of any one of Embodiments 1-3, wherein the reaction product comprises a transesterification product of the polyester blend.

[0063] Embodiment 5 provides the carpet yarn of any one of Embodiments 1-3, wherein the homogeneous polymer blend is free of transesterification reaction products of the polyester blend.

[0064] Embodiment 6 provides the carpet yarn of any one of Embodiments 1-5, wherein the homogeneous polymer blend comprises a combination of the polyester blend and the reaction product thereof. [0065] Embodiment 7 provides the carpet yarn of any one of Embodiments 1 -4 or 6, wherein the polyester blend is 0.001 wt% to 100 wt% of the homogeneous polymer blend and the reaction product of the polyester blend is 0.001 wt% to 100 wt% of the homogeneous polymer blend.

[0066] Embodiment 8 provides the carpet yarn of any one of Embodiments 1 -7, wherein the homogeneous polymer blend is substantially free of heterogeneously distributed polymer. [0067] Embodiment 9 provides the carpet yarn of any one of Embodiments 1-8, wherein the homogeneous polymer blend is free of dispersed (i.e., discontinuous) polymer phases, or dispersed polymer phases are less than 5 wt% of the homogeneous polymer blend.

[0068] Embodiment 10 provides the carpet yarn of any one of Embodiments 1 -9, wherein the homogeneous polymer blend is free of dispersed phases of PET, co-PET, or PBT, or dispersed phases of PET, co-PET, or PBT are less than 5 wt% of the homogeneous polymer blend.

[0069] Embodiment 11 provides the carpet yarn of any one of Embodiments 1-10, wherein the homogeneous polymer blend is free of dispersed phases of PET, or dispersed phases of PET are less than 5 wt% of the homogeneous polymer blend.

[0070] Embodiment 12 provides the carpet yarn of any one of Embodiments 1-11, wherein the homogeneous polymer blend is a continuous polymer phase.

[0071] Embodiment 13 provides the carpet yarn of any one of Embodiments 1-12, wherein the homogeneous polymer blend is substantially free of talc.

[0072] Embodiment 14 provides the carpet yarn of any one of Embodiments 1-13, wherein the homogeneous polymer blend comprises 0 wt% to 3 wt% talc.

[0073] Embodiment 15 provides the carpet yarn of any one of Embodiments 1-14, wherein the PET and/or co-PET and the PBT are the only polyesters in the polyester blend.

[0074] Embodiment 16 provides the carpet yarn of any one of Embodiments 1-15, wherein the PET and/or co-PET and the PBT are the only synthetic polymers in the polyester blend.

[0075] Embodiment 17 provides the carpet yarn of any one of Embodiments 1-16, wherein the polyester blend is free of polypropylene terephthalate). [0076] Embodiment 18 provides the carpet yarn of any one of Embodiments 1-17, wherein fibers of the carpet yarn comprising the homogeneous polymer blend have a round or ovular profile.

[0077] Embodiment 19 provides the carpet yarn of any one of Embodiments 1-18, wherein the PET, co-PET, or the combination thereof is 2 wt% to 40 wt% of the total weight of polyesters in the polyester blend, and wherein the PBT is 60 wt% to 98 wt% of the total weight of polyesters in the polyester blend.

[0078] Embodiment 20 provides the carpet yarn of any one of Embodiments 1-19, wherein the PET, co-PET, or the combination thereof is 5 wt% to 40 wt% of the total weight of polyesters in the polyester blend, and wherein the PBT is 60 wt% to 95 wt% of the total weight of polyesters in the polyester blend.

[0079] Embodiment 21 provides the carpet yarn of any one of Embodiments 1-20, wherein the PET, co-PET, or the combination thereof is 5 wt% to 30 wt% of the total weight of polyesters in the polyester blend, and wherein the PBT is 70 wt% to 95 wt% of the total weight of polyesters in the polyester blend.

[0080] Embodiment 22 provides the carpet yarn of any one of Embodiments 1-21, wherein the PET, co-PET, or the combination thereof is 7 wt% to 30 wt% of the total weight of polyesters in the polyester blend, and wherein the PBT is 70 wt% to 93 wt% of the total weight of polyesters in the polyester blend.

[0081] Embodiment 23 provides the carpet yarn of any one of Embodiments 1-22, wherein the homogeneous polymer blend is 90 wt% to 100 wt% of the carpet yarn.

[0082] Embodiment 24 provides the carpet yarn of any one of Embodiments 1-23, wherein the PET, co-PET, or the combination thereof, and the PBT is 90 wt% to 100 wt% of the polyester blend.

[0083] Embodiment 25 provides the carpet yarn of any one of Embodiments 1-24, wherein the total weight of polyesters in the carpet yarn is 90 wt% to 100 wt% of the carpet yarn. [0084] Embodiment 26 provides the carpet yarn of any one of Embodiments 1-25, wherein the PET, co-PET, or combination thereof is present in the polyester blend in an amount sufficient to reduce in the homogeneous polymer blend a peak melting point of the PBT without creating a separate PET/co-PET peak melting point in the range of 225 °C to 255 °C in a DSC scan. [0085] Embodiment 27 provides the carpet yarn of any one of Embodiments 1-26, wherein the PET, co-PET, or combination thereof has an intrinsic viscosity of 0.40 dL/g to 1.5 dL/g.

[0086] Embodiment 28 provides the carpet yarn of any one of Embodiments 1-27, wherein the PET, co-PET, or combination thereof has an intrinsic viscosity of 0.6 dL/g to 1.10 dL/g.

[0087] Embodiment 29 provides the carpet yarn of any one of Embodiments 1-28, wherein the PET, co-PET, or combination thereof has an intrinsic viscosity of 0.70 dL/g to 1.00 dL/g.

[0088] Embodiment 30 provides the carpet yarn of any one of Embodiments 1-29, wherein the polyester blend comprises the co-PET, wherein the co-PET is a copolymer comprising isophathalic acid that is 5 wt% or less of the co-PET.

[0089] Embodiment 31 provides the carpet yarn of any one of Embodiments 1-30, wherein the PBT has an intrinsic viscosity of 0.70 dL/g to 1.50 dL/g.

[0090] Embodiment 32 provides the carpet yarn of any one of Embodiments 1-31, wherein the PBT has an intrinsic viscosity of 1.1 dL/g to 1.5 dL/g.

[0091] Embodiment 33 provides the carpet yarn of any one of Embodiments 1-32, wherein the PBT has an intrinsic viscosity of 1.2 dL/g to 1.5 dL/g.

[0092] Embodiment 34 provides the carpet yarn of any one of Embodiments 1-33, wherein the PBT has a viscosity number of 107 cm³/g to 180 cm³/g.

[0093] Embodiment 35 provides the carpet yarn of any one of Embodiments 1-34, wherein the PBT has a viscosity number of 140 cm³/g to 180 cm³/g.

[0094] Embodiment 36 provides the carpet yarn of any one of Embodiments 1-35, wherein the homogeneous polymer blend, or a combination thereof, comprises one or more polymer modifiers.

[0095] Embodiment 37 provides the carpet yarn of Embodiment 36, wherein the one or more polymer modifiers are 2 wt% or less of the homogeneous polymer blend.

[0096] Embodiment 38 provides the carpet yarn of any one of Embodiments 36-37, wherein the polymer modifier comprises a nucleating agent, lubricant, slip additive, or a combination thereof. [0097] Embodiment 39 provides the carpet yarn of any one of Embodiments 1-38, wherein the homogeneous polymer blend comprises one or more functional additives for carpet yarns.

[0098] Embodiment 40 provides the carpet yarn of Embodiment 39, wherein the one or more functional additives comprise a flame-retardant additive, a stain-resistant additive, or a combination thereof.

[0099] Embodiment 41 provides the carpet yarn of any one of Embodiments 1-40, wherein the homogeneous polymer blend one or more carpet yarn pigments.

[00100] Embodiment 42 provides the carpet yarn of Embodiment 41 , wherein the one or more carpet yarn pigments comprise TiCh.

[00101] Embodiment 43 provides the carpet yarn of any one of Embodiments 1-42, wherein the homogeneous polymer blend comprises one or more compatibilizers for PET and PBT.

[00102] Embodiment 44 provides the carpet yarn of Embodiment 43, wherein the one or more compatibilizers for PET and PBT comprise a linear polyester chain extender.

[00103] Embodiment 45 provides the carpet yarn of any one of Embodiments 1-42, wherein the homogeneous polymer blend is free of compatibilizers.

[00104] Embodiment 46 provides the carpet yarn of any one of Embodiments 1-43, wherein the homogeneous polymer blend is free of chain extenders.

[00105] Embodiment 47 provides the carpet yarn of any one of Embodiments 1-46, wherein the homogeneous polymer blend is free of maleic anhydride-grafted polymers/copolymers and maleic anhydride copolymers.

[00106] Embodiment 48 provides the carpet yarn of any one of Embodiments 1-47, wherein the homogeneous polymer blend is free of maleic anhydride-grafted polyethylene polymers/copolymers and maleic anhydride/polyethylene copolymers.

[00107] Embodiment 49 provides the carpet yarn of any one of Embodiments 1-48, wherein the homogeneous polymer blend is free of maleic anhydride-grafted polypropylene, maleic-anhydride-grafted ethylene-octene copolymer, and styrene-maleic anhydride copolymers. [00108] Embodiment 50 provides the carpet yarn of any one of Embodiments 1-49, wherein the homogeneous polymer blend is free of dispersing agents and surfactants. [00109] Embodiment 51 provides the carpet yarn of any one of Embodiments 1-50, wherein the homogeneous polymer blend is free of stearates.

[00110] Embodiment 52 provides the carpet yarn of any one of Embodiments 1-51, wherein the homogeneous polymer blend is free of stearate salts.

[00111] Embodiment 53 provides the carpet yarn of any one of Embodiments 1-52, wherein the homogeneous polymer blend is free of calcium stearate and zinc stearate.

[00112] Embodiment 54 provides the carpet yarn of any one of Embodiments 1-53, wherein the homogeneous polymer blend is free of waxes.

[00113] Embodiment 55 provides the carpet yarn of any one of Embodiments 1-54, wherein the homogeneous polymer blend is free of polyethylene waxes.

[00114] Embodiment 56 provides the carpet yarn of any one of Embodiments 1-55, wherein the homogeneous polymer blend is free of transesterification inhibitors.

[00115] Embodiment 57 provides the carpet yarn of any one of Embodiments 1-56, wherein the homogeneous polymer blend is free of organophosphorous compounds.

[00116] Embodiment 58 provides the carpet yarn of any one of Embodiments 1-57, wherein the homogeneous polymer blend is free of as organophosphates and organophosphites. [00117] Embodiment 59 provides the carpet yarn of any one of Embodiments 1-58, wherein the homogeneous polymer blend is free of triphenyl phosphite, octadecyl phosphite, triphenyl phosphate, dioctadecyl phosphate, diphenyl phosphate, dibenzyl phosphate, decyldiphenyl phosphate, phosphoric acid, phosphate ester, sodium dihydrogen phosphate, hydrogen phosphates of zinc or calcium, and silica.

[00118] Embodiment 60 provides the carpet yarn of any one of Embodiments 1-59, wherein the homogeneous polymer blend comprises a transesterification promoter.

[00119] Embodiment 61 provides the carpet yarn of any one of Embodiments 1-60, wherein the homogeneous polymer blend comprises a transesterification catalyst.

[00120] Embodiment 62 provides a carpet comprising the carpet yarn of any one of Embodiments 1-61.

[00121] Embodiment 63 provides the carpet of claim 62, wherein 100 wt% of carpet fibers in the carpet are the carpet yarn. [00122] Embodiment 64 provides the carpet of any one of Embodiments 62-63, wherein the carpet has equal or better durability than a corresponding carpet having 100 wt% PBT yarn in place of the carpet yarn.

[00123] Embodiment 65 provides the carpet of any one of Embodiments 62-64, wherein the carpet has equal or better tuft definition than a corresponding carpet having 100 wt% PBT yarn in place of the carpet yarn.

[00124] Embodiment 66 provides the carpet of any one of Embodiments 62-65, wherein the carpet has equal or better durability and tuft definition than a corresponding carpet having 100 wt% PBT yarn in place of the carpet yarn.

[00125] Embodiment 67 provides the carpet of any one of Embodiments 62-66, wherein the carpet has maintains tuft definition over time better than a corresponding carpet having 100 wt% PBT yarn in place of the carpet yarn.

[00126] Embodiment 68 provides the carpet of any one of Embodiments 62-67, wherein the carpet has equal or better durability and/or tuft definition than a corresponding carpet comprising BCF yarns including dispersed polymer phases of PET, co-PET, PBT, and/or reaction products thereof in place of the homogeneous polymer blend of the carpet yarn.

[00127] Embodiment 69 provides the carpet of any one of Embodiments 62-68, wherein the carpet has equal or better durability, tuft definition, or a combination thereof, than a corresponding carpet having 100 wt% PBT yarn in place of the carpet yarn, as determined by: Vetterman Drum test, measured according to ASTM D5417-93, or Hexapod Drum test, measured according to ASTM D5252, or Chair castor test, measured according to ASTM D6962, or Walk test, measured according to ASTM D6119, or a combination thereof.

[00128] Embodiment 70 provides a bulked continuous filament (BCF) carpet yarn comprising: a homogeneous polymer blend that is 90 wt% or more of the carpet yarn, the homogeneous polymer blend comprising polyethylene terephthalate (PET) or co-PET, wherein the PET, co-PET, or a combination thereof is 5 wt% to 40 wt% of a total weight of polyesters in the homogeneous polymer blend; and polybutylene terephthalate (PBT), wherein the PBT is 60 wt% to 95 wt% of the total weight of polyesters in the homogeneous polymer blend; wherein the PET, co-PET, or combination thereof is present in the polyester blend in an amount sufficient to reduce in the homogeneous polymer blend a peak melting point of the PBT without creating a separate PET/co-PET peak melting point in the range of 225 °C to 255 °C in a DSC scan.

[00129] Embodiment 71 provides the carpet yarn and carpet of any one or any combination of Embodiments 1-69 optionally configured such that all elements or options recited are available to use or select from.

Claims

CLAIMS What is claimed is:

1. A bulked continuous filament (BCF) carpet yarn comprising: a homogeneous polymer blend comprising a polyester blend and/or a reaction product thereof, the polyester blend comprising polyethylene terephthalate (PET) or co-PET, wherein the PET, co-PET, or a combination thereof is 1 wt% to 50 wt% of a total weight of polyesters in the homogeneous polymer blend; and poly butylene terephthalate (PBT), wherein the PBT is 50 wt% to 99 wt% of the total weight of polyesters in the homogeneous polymer blend.

2. The carpet yarn of claim 1 , wherein the homogeneous polymer blend comprises the reaction product of the polyester blend.

3. The carpet yarn of any one of claims 1-2, wherein less than 5 wt% of the homogeneous polymer blend is discontinuous phases of PET, co-PET, or PBT.

4. The carpet yarn of any one of claims 1-3, wherein the PET, co-PET, or the combination thereof is 5 wt% to 30 wt% of the total weight of polyesters in the polyester blend, and wherein the PBT is 70 wt% to 95 wt% of the total weight of polyesters in the polyester blend.

5. The carpet yarn of any one of claims 1-4, wherein the PET, co-PET, or combination thereof is present in the polyester blend in an amount sufficient to reduce a peak melting point of the PBT in the homogeneous polymer blend without creating a separate PET/co-PET peak melting point in the range of 225 °C to 255 °C in a DSC scan.

6. The carpet yarn of any one of claims 1-5, wherein the PET, co-PET, or combination thereof has an intrinsic viscosity of 0.40 dL/g to 1.5 dL/g. 7. The carpet yarn of any one of claims 1-6, wherein the PBT has an intrinsic viscosity of 0.

7 dL/g to 1.5 dL/g.

8. The carpet yarn of any one of claims 1-7, wherein the homogeneous polymer blend comprises one or more functional additives for carpet yarns, wherein the one or more functional additives comprise a flame-retardant additive, a stain-resistant additive, or a combination thereof.

9. The carpet yarn of any one of claims 1-8, wherein the homogeneous polymer blend comprises 0 wt% to 2 wt% talc.

10. The carpet yarn of claim 1-9, wherein the homogeneous polymer blend is free of maleic anhydride-grafted polymers/copolymers and maleic anhydride copolymers.

11. The carpet yarn of claim 1-10, wherein the homogeneous polymer blend is free of stearate salts and polyethylene waxes.

12. The carpet yarn of claim 1-11, wherein the homogeneous polymer blend is free of transesterification inhibitors.

13. A bulked continuous filament (BCF) carpet yarn comprising: a homogeneous polymer blend that is 90 wt% or more of the carpet yarn, the homogeneous polymer blend comprising polyethylene terephthalate (PET) or co-PET, wherein the PET, co-PET, or a combination thereof is 5 wt% to 40 wt% of a total weight of polyesters in the homogeneous polymer blend; and polybutylene terephthalate (PBT), wherein the PBT is 60 wt% to 95 wt% of the total weight of polyesters in the homogeneous polymer blend; wherein the PET, co-PET, or combination thereof is present in the polyester blend in an amount sufficient to reduce a peak melting point of the PBT in the homogeneous polymer blend without creating a separate PET/co-PET peak melting point in the range of 225 °C to 255 °C in a DSC scan.

14. A carpet comprising the carpet yarn of any one of claims 1-13.

15. The carpet of claim 14, wherein the carpet has equal or better durability, maintains tuft definition better over time, or a combination thereof, as compared to a corresponding carpet having 100 wt% PBT yarn in place of the carpet yarn, as determined by:

Vetterman Drum test, measured according to ASTM D5417-93, or Hexapod Drum test, measured according to ASTM D5252, or Chair castor test, measured according to ASTM D6962, or Walk test, measured according to ASTM D6119, or a combination thereof.