阅读说明：本技术 化学改性的聚酯和其制造方法 (Chemically modified polyester and process for producing the same ) 是由 M·E·波特 M·A·巴杰尔 何义勇 S·科斯特 G·F·比洛维奇 W·黄 E·尼科利 于 2020-03-27 设计创作，主要内容包括：公开了化学改性的聚酯、其形成低密度泡沫的可发泡组合物,以及制造可发泡组合物和泡沫的方法。所述组合物包含无定形共聚酯、或无定形共聚酯聚碳酸酯或无定形共聚酯聚醚或其组合。此外,公开了用于低密度泡沫的用途。(Chemically modified polyesters, foamable compositions thereof that form low density foams, and methods of making foamable compositions and foams are disclosed. The composition comprises an amorphous copolyester, or an amorphous copolyester polycarbonate, or an amorphous copolyester polyether, or a combination thereof. Furthermore, use for low density foams is disclosed.)

1. A copolyester, copolyesterpolycarbonate or copolyesterpolyether copolymer comprising different polyester units, or comprising polyester units and polycarbonate or polyether units, or both, and optionally further comprising one or more coupling agents, and characterized by having

Polymerized units of one or more aromatic diacid monomers;

a total of 10 to 40 mole percent of polymerized units of one or more aliphatic diols, wherein mole percent is the sum of the moles of polymerized units of the one or more aliphatic diols in the copolymer, expressed as a percentage of the total moles of copolymerized units comprising the copolymer;

a primary Tg between 85 ℃ and 125 ℃ measured from the inflection point of the second heating of the DSC curve using a heating/cooling rate of 10 ℃/min; and

exposure to 1000psiCO at 135 deg.C₂Has a heat of fusion, Δ H, of not more than 10J/g after 4 hours of hydrostatic pressure of (A)_mA peak value.

2. The copolyester, copolyesterpolycarbonate or copolyesterpolyether copolymer according to claim 1 having a B [ X ] or B [ X + X '] value of 0.20 or more, wherein B is the Koenig B value of the randomness of the copolymer, [ X ] is the molar fraction of comonomer polyester structural units or comonomer polycarbonate and/or polyether structural units in the copolymer, and [ X + X' ] is the molar fraction of comonomer polyester structural units or comonomer polycarbonate and/or polyether structural units, including any units comprising a residue fraction thereof, in the copolymer.

3. The copolyester, copolyestercarbonate or copolyethercopolymer according to claim 1 having a KoenigB value of greater than 0.90 for a copolymer having the structural units polyester: polycarbonate in the copolymer or the molar ratio of the structural units polyester (polycarbonate + polyether) in the copolymer being from 65: 35 to 85: 15.

4. The copolyester, copolyestercarbonate or copolyethercopolymer according to claim 1 wherein the one or more aromatic diacid monomers are selected from phthalic acid, terephthalic acid, isophthalic acid or 2, 5-furandicarboxylic acid.

5. The copolyester, copolyesterpolycarbonate or copolyesterpolyether or copolymer according to claim 1 wherein at least a portion of the polyester units in the copolymer are derived from recycled polyethylene terephthalate.

6. The copolyester, copolyestercarbonate or copolyethercopolymer according to claim 1 wherein the copolyester, copolyestercarbonate or copolyethers comprise at least 7 mole% of polymerized units of bisphenol a.

7. The copolyester, copolyestercarbonate or copolyethercopolymer according to claim 1 wherein the molar ratio of polyester polymer structural units to the sum of polycarbonate polymer structural units and polyether polymer structural units is from 40: 60 to 85: 15.

8. A foamable composition comprising the copolyester, copolyestercarbonate or copolyethercopolymer of claim 1 and one or more blowing agents, and optionally, further comprising an immiscible polyolefin, a colorant, a filler, a flame retardant, an infrared attenuating agent, a nucleating agent, a lubricant, an antistatic agent or an antioxidant, or a combination thereof.

9. A foamed or frothed article obtained from the composition of claim 8.

10. The foam or foamed article of claim 9, wherein the foam has from 0.01 to 0.1g/cm³The density of (c).

11. A method of forming the copolyester, copolyesterpolycarbonate or copolyesterpolyether copolymer of claim 1, comprising:

(i) melting a blend of at least two polymers selected from a first polyester polymer and one or more other polymers selected from one or more polycarbonate polymers and one or more other polyester polymers, or a combination thereof, and in the presence of a transesterification catalyst and optionally a chain coupling agent;

(ii) maintaining the temperature above 200 ℃ and below 330 ℃ for at least 3 minutes and not more than 180 minutes, optionally with mixing;

(iii) optionally, collecting at least a portion of any ethylene carbonate produced; and (iv) cooling to produce a solid copolymer.

12. The method of claim 11 wherein the weight ratio of the first polyester polymer to the one or more other polymers is from 40: 60 to 85: 15.

13. The method of claim 11, wherein the weight ratio of the total amount of all polyester polymers to polycarbonate polymer is from 40: 60 to 85: 15.

14. The method of claim 11, wherein the one or more polyester polymers is recycled polyethylene terephthalate.

15. Copolyester, copolyester polycarbonate or copolyester polyetherCopolymerComprising a polymeric structural unit selected from:

a) one or more aliphatic diols selected from the group consisting of,

b) one or more of the aromatic diacids of the aromatic diacid,

c) one or more of the aromatic diols in the aromatic diol mixture,

d) one or more organic carbonates in a mixture of organic carbonates,

wherein the copolyester copolymer comprises polymerized structural units a + b

The copolyester polycarbonate copolymer comprises polymerized structural units a + b + c + d, and

the copolyester polyether copolymer comprises polymeric structural units a + b + c + optionally d, and further comprises ether functional groups in the polymer backbone;

the copolymer is characterized in that:

i) the polymerized structural units of the one or more aliphatic diols (a) are present in an amount totaling from 15 to 40 mol%, where mol% is the sum of the moles of polymerized structural units of the one or more aliphatic diols in the copolymer, expressed as a percentage of the total moles of polymerized structural units a + b + c + d constituting the copolymer;

ii) a primary Tg between 85 ℃ and 125 ℃ measured from the inflection point of the second heating of the DSC curve using a heating/cooling rate of 10 ℃/min; and

iii) Exposure to 1000psiCO at 135 deg.C₂Has a heat of fusion, Δ H, of not more than 10J/g after 4 hours of hydrostatic pressure of (A)_mA peak value.

Technical Field

Chemically modified polyesters and methods of making the same are described herein. More specifically, the chemically modified polyester is an amorphous copolymer. In addition, methods of making and using these compositions are described herein. The processes disclosed herein can utilize virgin or recycled polyester polymers as source polymers, such as, for example, semi-crystalline polyethylene terephthalate (PET), including recycled PET, to form amorphous copolyesters useful as components in foamable compositions. The resulting low density foams disclosed herein (e.g., 0.1 g/cm)³Or lower density) can be used, for example, in extruded and expanded bead foams, which can find application, for example, in insulation and/or other building and industrial applications.

Background

Crystalline and semi-crystalline polyester polymers cannot be easily foamed to produce low density foams because their crystalline or semi-crystalline nature means that high temperatures are required to prevent recrystallization of the material when the gas expands and produces a foam. In the molten state, above its recrystallization temperature, the viscosity of semi-crystalline polyesters (such as PET) is too low to allow the cells to expand significantly before hardening. This limits the foam density that can be achieved (to foams of higher density, e.g., densities greater than 0.1 g/cm)³). The present invention solves the problem of foaming crystalline or semi-crystalline polyesters to produce low density foams by converting semi-crystalline polyesters such as PET into amorphous copolyester polymeric materials that are capable of producing low density foams from polymer melts or from extruded and expanded beads.

The production of foamable polyesters or copolyesters derived from semi-crystalline PET allows the starting materials to be derived from "recycled" streams (from bottles and other post-consumer PET sources). For the purposes of the present invention, "recycled" refers to materials obtained after consumption and after industrial use. The recycled PET is in sufficient supply. Thus, one particularly desirable goal is to utilize recycled semi-crystalline PET and convert it to an amorphous polymer that can be foamed to produce a low density foam. Accordingly, there is a need for foamable compositions containing amorphous polymers derived from semi-crystalline polyesters (virgin or recycled polyesters, such as recycled PET), processes for making the amorphous polymers and foamable compositions, and methods of using the same. The present invention is directed to these and other important ends.

Disclosure of Invention

In one embodiment, the present invention relates to a copolyester, copolyester polycarbonate, or copolyester polyether copolymer comprising different polyester units, or comprising a polyester unit and a polycarbonate or polyether unit, or both, and optionally further comprising one or more coupling agents, and characterized by having:

(i) polymerized units of one or more aromatic diacid monomers;

(ii) a total of 10 to 40 mole percent of polymerized units of one or more aliphatic diols, wherein mole percent is the sum of the moles of polymerized units of the one or more aliphatic diols in the copolymer, expressed as a percentage of the total moles of copolymerized units comprising the copolymer;

(iii) a primary Tg between 85 ℃ and 125 ℃ measured from the inflection point of the second heating of the DSC curve using a heating/cooling rate of 10 ℃/min; and

(iv) exposure to 1000psi CO at 135 deg.C₂Has a heat of fusion, Δ H, of not more than 10J/g after 4 hours of hydrostatic pressure of (A)_mA peak value.

In another embodiment, the copolyester, copolyestercarbonate or copolyetherester copolymer has a B [ X ] or B [ X + X '] value of 0.20 or greater, wherein B is the Koenig B value of the randomness of the copolymer, [ X ] is the mole fraction of comonomer polyester structural units or comonomer polycarbonate and/or polyether structural units in the copolymer, and [ X + X' ] is the mole fraction of comonomer polyester structural units or comonomer polycarbonate and/or polyether structural units, including any units comprising a residue segment thereof, in the copolymer.

The present invention also relates to a foamable composition comprising a copolyester, copolyester polycarbonate, or copolyester polyether copolymer and one or more blowing agents.

Drawings

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention. In the figure:

FIG. 1 shows the results for virgin polyethylene terephthalate and virgin polycarbonate: (3158) The 75/25 blend (by weight) at 275 ℃ has an increase in the Koenig B value of the monomer distribution in the polymer chain as a function of the reaction time (in minutes). The catalyst was monobutyl tin oxide, MBTO (2,000 ppm-parts by weight of MBTO per million parts by weight of the total weight of the two reactant polymers).

Fig. 2 shows the transesterification reaction between Polycarbonate (PC) and polyethylene terephthalate (PET) and two side reactions.

FIG. 3 shows representative quantitation of PC/PET copolymer¹³C NMR spectrum and peak assignment. The digital label is the assignment of each individual carbon. Letter labels superimposed on the NMR resonance peaks designate the integration region to calculate the mole fraction of structural units (whole copolymer composition).

Detailed Description

In the case of semi-crystalline PET, foaming must occur above the crystallization temperature of PET (about 150 ℃), at which point the polymer has very low melt strength and only minimally expands before vitrification begins. As disclosed herein, PET (virgin or recycled) becomes amorphous. Elimination of crystallization allows the polymer to be run at temperatures below 150 ℃Processing in which the melt strength is inherently greater. This facilitates cell expansion, resulting in a low density product. However, although it is necessary to eliminate the crystallinity in the pure form of the polymer, it is not sufficient to achieve foamability. The addition of one or more soluble blowing agents will increase the crystallization rate. Thus, another challenge is to avoid crystallization of the polymer under certain pressures. Further specifically disclosed herein are blowing agents (such as, for example, CO) of this type₂) In the presence, a reduction in what polymer block structure is required to sufficiently reduce the crystallization rate. This is that the polymer can be suitably foamed at temperatures below 150 ℃ to achieve less than 0.1g/cm³The density of (c).

Unlike semi-crystalline PET, which is known to have poor solubility for typical blowing agents, the process of the present invention modifies PET to produce an amorphous polymer having higher solubility for typical blowing agents and allows for the production of low density foam articles. Preventing the formation of crystalline structures also increases gas permeability, which facilitates cell growth during foam processing.

Recycled PET can be used for foaming by reducing or eliminating its ability to crystallize in the presence of heat and/or dissolved gases. This is achieved by: molten PET is subjected to direct transesterification with one or more other polymers in the presence of a catalyst to promote rearrangement and alteration of the repeating units contained in the polymer to form a new copolyester (e.g., a copolyester polycarbonate or copolyester polyether). The non-PET polymer component need not be polyester and need not be amorphous. The deliberate elimination of carbonyl and ethylene glycol species results in a copolyester or copolyester polyether backbone structure with an increased Tg. With proper catalyst selection, temperature and reaction time, the resulting polymer has a sufficiently slow crystallization rate. This reduction or elimination of crystallization allows processing at temperatures below 150 ℃ (the crystallization temperature of the starting PET material). The final copolyester (or copolyester polycarbonate or copolyester polyether) can be melt blended with a physical blowing agent and expanded by extrusion foaming or rapidly cooled in a separate process (expandable beads).

The invention may be understood more readily by reference to the following detailed description, examples, drawings and claims, and their previous and following description. It is to be understood, however, that this invention is not limited to the particular compositions, articles, devices, systems and/or methods disclosed unless otherwise specified, and as such, may, of course, vary. Although aspects of the invention may be described and claimed in particular legal categories (e.g., material composition legal categories), this is for convenience only and those skilled in the art will understand that each aspect of the invention can be described and claimed in any legal category.

The following description of the invention is provided as a practical teaching of the invention in its best, currently known aspect. To this end, those skilled in the relevant art will recognize and appreciate that changes and modifications can be made to the various aspects of the invention described herein, while still obtaining the beneficial results of the present invention. It will also be apparent that some of the benefits of the present invention can be obtained by selecting some of the features of the present invention without utilizing other features. Accordingly, one of ordinary skill in the relevant art will recognize that many modifications and adaptations to the present invention are possible and may even be desirable in certain circumstances and are therefore a part of the present invention.

While the present invention is susceptible of embodiment in various forms, the following description of several embodiments is provided with the understanding that the present disclosure is to be considered an exemplification of the invention, and is not intended to limit the invention to the specific embodiments illustrated. Headings are provided for convenience only and should not be construed as limiting the invention in any way. Embodiments shown under any heading or any section of the disclosure can be combined with embodiments shown under the same or any other heading or section of the disclosure.

Any combination of the elements described herein, in all possible variations thereof, is encompassed by the invention unless otherwise indicated herein or otherwise clearly contradicted by context.

Unless expressly stated otherwise, it is in no way intended that any method or aspect set forth herein be construed as requiring that its steps be performed in a specific order. Thus, where method claims do not specifically state that steps are to be limited to a particular order in the claims or description, no order is intended in any way to be inferred. This applies to any possible non-explicit basis for interpretation, including logical issues regarding the arrangement of steps or operational flows, simple meanings derived from grammatical organization or punctuation, or the number or type of embodiments described in the specification. It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive.

All publications mentioned herein are incorporated herein by reference to disclose and describe the methods and/or materials in connection with which the publications are cited.

It is to be understood that the terminology used herein is for the purpose of describing particular aspects only and is not intended to be limiting. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. In this specification and in the claims that follow, reference will be made to a number of terms that are defined herein.

As used in the specification and the appended claims, the singular forms "a", "an" and "the" include plural referents unless the context clearly dictates otherwise.

As used herein, the term "and/or" means "and, or as an alternative.

As used herein, the term "optional" or "optionally" means that the subsequently described event, condition, component, or circumstance may or may not occur, and that the description includes instances where said event, condition, component, or circumstance occurs and instances where it does not.

As used herein, the phrase "sufficient to" (e.g., "sufficient conditions") refers to such values or conditions: which is capable of performing a function or characteristic that represents a sufficient value or condition. As will be noted below, the exact values or specific conditions required may vary from one embodiment to another, depending on recognized variables such as the materials employed and/or the processing conditions.

Unless specifically indicated to the contrary, the term "by weight" when used in conjunction with a component is based on the total weight of the formulation or composition in which the component is included. For example, if a particular element or component in a composition or article is said to be present in an amount of 8 wt.%, it is understood that this percentage is relative to the total compositional percentage of 100% (and thus may be written as 8 wt.%). In some examples, the weight percentages of the components are based on the total weight of the composition ("on a dry basis"), which indicates the weight of the composition free of water (e.g., less than about 1 wt.%, less than about 0.5 wt.%, less than about 0.1 wt.%, less than about 0.05 wt.%, or about 0 wt.% water, based on the total weight of the composition).

When numerical values, e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, are disclosed herein, the following sentences typically follow such numerical values: "each of the foregoing numbers may be preceded by the terms" about "," at least about ", or" less than about ", and any of the foregoing numbers may be used alone to describe an open range or in combination to describe a closed range". This phrase means that each of the aforementioned numbers can be used alone (e.g., 4), can begin with the word "about" (e.g., about 8), can begin with the phrase "at least about" (e.g., at least about 2), can begin with the phrase "less than about" (e.g., less than about 7), or can be used in any combination with or without any of the preceding words or phrases to define a range (e.g., 2 to 9, about 1 to 4, 8 to about 9, about 1 to about 10, etc.). Further, when a range is described as "about X or less," this phrase is the same as the range that is the combination of "about X" and "less than about X" in the alternative. For example, "about 10 or less" is the same as "about 10 or less than about 10". Such interchangeable range descriptions are contemplated herein. Other range forms are disclosed herein, but differences in form should not be construed as to imply that there is a substantial difference.

Unless expressly indicated otherwise, the use of numerical values in the various quantitative values specified in this application are stated as approximations as if both the minimum and maximum values within the stated range were preceded by the word "about". In this way, slight variations from the values can be used to achieve substantially the same results as the values. Also, the disclosed ranges are intended as continuous ranges including every value between the recited minimum and maximum values and any range that can be formed by such values. Also disclosed herein are any and all ratios (and ranges of any such ratios) that can be formed by dividing a recited value by any other recited value. Thus, the skilled person will understand that many such ratios, ranges, and ranges of ratios may be explicitly derived from the numerical values presented herein, and in all cases such ratios, ranges, and ranges of ratios represent various embodiments of the present invention.

As used herein, the term "substantially free" means that the composition has less than about 1 wt.%, e.g., less than about 0.5 wt.%, less than about 0.1 wt.%, less than about 0.05 wt.%, or less than about 0.01 wt.% of the material, based on the total weight of the composition.

As used herein, the term "substantially," when used in reference to a composition, refers to at least about 60 weight percent, such as at least about 70 weight percent, at least about 80 weight percent, at least about 90 weight percent, at least about 95 weight percent, at least about 98 weight percent, at least about 99 weight percent, or about 100 weight percent of a specified feature or component, based on the total weight of the composition.

The term "polyester" herein refers to a polymer whose repeating units are characterized by ester groups. The term therefore includes not only homopolymers, i.e. polyesters consisting of one acid component and one alcohol component or one hydroxycarboxylic acid component or one lactone component, but also copolymers, i.e. polyesters consisting of at least two acid components and/or alcohol components, and/or hydroxycarboxylic acid components and/or lactone components ("copolyesters"). The term "copolyester" is a subset of polyesters. Where the copolymer results from the transesterification of two different polyester polymers, the resulting copolymer is referred to herein as a "copolyester" copolymer or "mixed copolyester" to distinguish the general term copolyester when also referring to a copolyester polycarbonate or copolyester polyether. In the case of copolymers made of polyestersWhere the transesterification reaction of the polymer and polycarbonate polymer results, the resulting copolymer (copolyester) is referred to herein as a "copolyester polycarbonate" copolymer. The term "copolyester polycarbonate" is a subset of copolyesters. It will be appreciated that under some reaction conditions, such polymers may lose CO₂Units such that the resulting functional group is an ether unit (from CO in the carbonate unit)₂Caused by losses). In case 100% (or close to 100%, such as for example 99.5%, or 99%, or 95%) of the possible carbonate functions are converted into ether functions, the resulting polymer is herein referred to as "copolyester polyether" (the term "copolyester polyether" is a subset of copolyesters). Otherwise (i.e., less than 95%, or less than 99%, or less than 99.5% of the possible carbonate functionality is converted to ether functionality), the copolymer is still referred to as a copolyesterpolycarbonate.

The polyesters may be obtained from conventional synthetic means using dicarboxylic acids and difunctional alcohols. Aromatic dicarboxylic acids are preferred. Examples of suitable dicarboxylic acids include phthalic acid, isophthalic acid, terephthalic acid, and 2, 5-furandicarboxylic acid (FDCA). Examples of suitable difunctional alcohols (diols) that may be combined with any of these dicarboxylic acids include ethylene glycol, propylene glycol (propanediol 1), including propylene glycol, butylene glycol (butylene glycol), cyclohexanedimethanol, isosorbide and spiroglycol.

The copolyester may be obtained, for example, by a transesterification reaction of two or more different polyester polymers, as discussed further herein.

Polycarbonate polymers include those obtainable from the reaction of polyfunctional alcohols (e.g., diols, including those disclosed above, as well as bisphenol a, BPA) with carbonic acid derivatives (e.g., such as diphenyl carbonate, dimethyl carbonate, ethylene carbonate, or phosgene). For example, the polymer most commonly referred to as polycarbonate can be synthesized by the reaction of phosgene (or dimethyl carbonate) and BPA.

Copolyester polycarbonates and copolyesterpolyethers (derived at least formally from copolyester polycarbonates) may be obtained, for example, by the transesterification reaction of one or more polyester polymers with one or more polycarbonate polymers, as discussed further herein. As previously mentioned, elimination of CO from copolyesterpolycarbonate copolymers₂May result in the formation of copolyester polyether copolymers. Such side reactions may or may not occur on every possible building block unit along the polymer chain.

The term "building block" is used herein in its normal meaning in the art. In polymer chemistry, the building blocks are part of the polymer chain. It is the result of the polymerization of monomers into long chains (polymers). There may be more than one structural unit in the repeat unit. When different monomers are polymerized, a copolymer is formed. For polyethylene terephthalate (PET), the monomer typically used to make the polymer is ethylene glycol (HO-CH)₂-CH₂-OH) and terephthalic acid (HOOC-C)₆H₄-COOH). In the polymer, there are two structural units, i.e. -O-CH₂-CH₂-O-and-OC-C₆H₄-CO-. The repeating units are: -CH₂-CH₂-O-CO-C₆H₄-CO-O-. Further, as used herein, the term "structural unit" may refer to a repeating segment comprising two monomeric units in polymerized form, which are repeating units within a polymer. For example, in the transesterification of a polyester (e.g., PET) and a Polycarbonate (PC), some of the repeat units in the product may be di-monomeric segments resulting from the original constituent polymer, such as, for example, the polyester repeat unit-CH₂-CH₂-O-CO-C₆H₄-CO-O-and other repeating segments, and these segments can be regarded as building blocks, wherein the distinction between monomeric and bimonomic building blocks is clarified or evident from the context. For example, a polyester di-monomer segment is a structural unit, and a polycarbonate di-monomer segment is a structural unit. The building blocks may be identified and quantified by techniques such as nuclear magnetic resonance spectroscopy (NMR), and the like, as discussed further herein.

Certain polymerization reactions or certain polymers undergoing reaction may involve side reactions that alter the structural unit (X) as compared to what would be expected from the monomer or polymerized monomer units. In the case of modified units losing part of their structure, e.g. CO from polycarbonate units₂In the case of molecules, the remainder is referred to as the residual fragment or residue (X'). Such species can still be identified by NMR and can be quantified in the count of structural units contained in the polymer by considering all units derived from the expected structural unit X to now be present in the polymer as a combination of X and X '(i.e., X + X'). Thus, [ X + X']Is the molar fraction of structural unit X and its residue X'.

The glass transition temperature, Tg, of the polymer was measured using Differential Scanning Calorimetry (DSC) and determined as the inflection point of the baseline step transition on the second heating of the sample (heating/cooling rate 10 ℃/min) and reported in degrees celsius. (see example 4).

Melting or crystallization enthalpy, Δ Hm, was measured by DSC using a linear baseline estimation of peak area and reported as J/g (measured as a linear integral of peak area with deviation from baseline, starting at 125 ℃ and ending at 250 ℃). In the presence of CO₂The sample analysis before the hydrostatic pressure of (a) is performed on a second temperature ramp. When exposed to blowing agents such as CO₂When the copolyester copolymer was previously subjected, this is referred to herein as "Δ Hm before foaming". Considering that the crystallization enthalpy of the crystallized PET is 140J/g, it can be estimated that a crystallization enthalpy less than 10J/g will represent a crystallinity of about 7% or less, and a crystallization enthalpy less than 5J/g will represent a crystallinity of less than 4%.

To evaluate exposure to CO₂Δ H after hydrostatic pressure of_mReferred to herein as "Δ Hm after foaming", the sample was compression molded into a 1.3mm thick film (25 tons pressure at 180 ℃ for 5 minutes) and placed in a pressure vessel. The vessel was heated to 135 ℃ and approximately 1000psi of carbon dioxide blowing agent was charged into the headspace to soak the sample for 4 hours. The pressure was then released rapidly to cause foaming in the sample. The enthalpy of fusion or crystallization, "Δ Hm after foaming", is then obtained using differential scanning calorimetry (as above and in the examples)4) except that the exposure to CO is performed on a first temperature ramp₂Analysis of the sample after hydrostatic pressure.

As used herein, the term "foam" means light, foamy, fine bubbles formed in or on a liquid surface or formed from a liquid. Herein, depending on the context, the term may refer to a wet foam before drying, or it may be used to describe a dry foam. With respect to determining whether a sample can be successfully foamed ("foamable resin" or "foamable copolymer"), the molten sample must foam and be able to form a stable foam. In general, and in the end uses contemplated herein, a volume expansion of at least 3.5 times up to 8 times will produce a marginally sufficient foam. "good" foams result from a volume expansion of 8-11.5 times. Preferred foams are at least 11.5 volume expansions, more preferably at least 16 volume expansions. Volume expansion is achieved by adjusting the density of the solid polymer (e.g., 1.27g/cm in the case of PET)³) Divided by the density of the foam. The density of the foam was measured using the buoyancy method: weigh the sample (grams of foam sample) in air and weigh the buoyancy of the sample when under water at room temperature (the weight of the displaced water equals the volume of the displaced water since the density of the water is 1g/cm³This is in turn the volume of the foam sample, in cm³In units, no water absorption is assumed. Density of foam g/cm³And then calculated as the weight of the foam sample in air divided by the volume of the foam sample). The foams described herein meet these volume expansion targets.

As used herein, "stable foam" refers to a foam that is stable against observable shrinkage or collapse during the drying process and in the absence of any external forces other than the surrounding atmosphere.

As used herein, the term "rigid foam" refers to a dry foam having a cellular structure with a compressive strength greater than 5 psi.

As used herein, "ambient cure conditions" refers to a range of conditions typically experienced in an unconditioned outdoor space, and under which a spray or aerosol dispensed foam product can be dispensed and dried. This excludes environments that include any form of forced convection and/or heating.

All molecular weights and other values associated with molecular weights disclosed herein are measured by GPC.

As used herein, Gel Permeation Chromatography (GPC) refers to a chromatographic separation method in which molecules in solution are separated by their size. Separation is achieved by differential exclusion of sample molecules as they pass through a bed of porous particles, known as a separation column. GPC can be used to determine a substantially accurate molar mass distribution of polymer molecules. For example, the liquid fraction (eluent) that passes through the column is collected at a constant volume. As the polymer elutes through the column, molecules that are too large to permeate the column pores are excluded from the packed pore volume and elute at an earlier retention time, while smaller molecules permeate into the column pores and elute at a later time. The concentration of the eluted polymer can be measured by spectroscopic techniques, such as, for example, Refractive Index (RI) and Ultraviolet (UV). The eluate flow rate can also be continuously analyzed using RI, Low Angle Laser Light Scattering (LALLS), multi-angle laser light scattering (MALLS), UV, and/or viscometry.

As used herein, the terms "molar mass distribution", "MMD" and "molecular weight distribution" are used interchangeably and describe the number of moles or polymer chains (N) of each polymer species_i) The relationship between, and the molar mass (M) of the substance or polymer chain_i). The molar mass distribution of the polymer can be varied by polymer fractionation. Different averages may be defined according to the statistical methods applied and described herein.

As used herein, the term "number average molecular weight" (Mn or) Refers to the statistical average molecular weight of all polymer chains in the sample and is defined by the formula:

wherein M is_iIs the molecular weight of the chain and Ni is the number of chains with that molecular weight. M of Polymer_nCan be determined by methods well known to those of ordinary skill in the art using molecular weight standards (e.g., polystyrene standards, preferably certified or traceable molecular weight standards).

As used herein, the term "weight average molecular weight" (Mw or) Is defined by the formula:

wherein M is_iIs the molecular weight of the chain and N_iIs the number of chains having this molecular weight. And M_nIn contrast, M_wThe molecular weight of a given chain is taken into account in determining the contribution to the average molecular weight. Thus, the greater the molecular weight of a given chain, the greater the pair M of such chains_wThe greater the contribution. M of Polymer_wCan be determined by methods well known to those of ordinary skill in the art using molecular weight standards (e.g., polystyrene standards, preferably certified or traceable molecular weight standards). The Mw for foaming the polyester copolymers described herein should be at least 10,000.

Since copolymers are composed of at least two types of structural (or monomer/monomer residue) units, copolymers can be classified based on how these units are randomly arranged along the chain. One indicator characterizing the distribution of monomers along the copolymer chain is the "Koenig B-value" (B), which is defined by the formula for binary copolymers (see, e.g., EP 2,736,930B 1 to l.tau et al):

wherein X and Y are two structural units of the copolymer; [ X ] and [ Y ] are their corresponding mole fractions ([ X ] + [ Y ] ═ 1); [ XY ] and [ YX ] are the mole fractions of XY and YX diads. Two adjacent structural units in a polymer molecule form a diad. For the above-mentioned binary copolymers, there are four types of diads XX, XY, YX, YY, wherein [ XX ] + [ XY ] + [ YX ] + [ YY ] ═ 1. Index B significantly affects many physical properties of the copolymer, including morphology, crystallization, glass transition, solubility, mechanical properties, and the like.

NMR-based methods can be used to determine the copolymer composition and exact monomer ordering in the copolymer, as well as to calculate an index B that describes the blockiness (actually, reduced blockiness level) of the copolymer resulting from the catalyzed transesterification process. The B value has been shown to vary with processing conditions (e.g., temperature, time, and catalyst type) and the level of comonomer (e.g., polycarbonate) in the blend formulation. For example, FIG. 1 shows the variation of the Koenig B value (monomer distribution or blockiness) of the copolymer as a function of the reaction time for a catalyzed transesterification reaction of polyethylene terephthalate (PET, monomer building blocks, Y) and polycarbonate (PC, monomer building blocks, X) carried out at 275 ℃. The B value is obtained using the methods described herein. Further, the method can be used to distinguish foamable copolymer compositions described herein from those of the prior art.

The Koenig B value of the monomer distribution in the polymer can be described by where X represents comonomer (e.g. polycarbonate) repeat units and Y represents polyester monomer (e.g. PET) repeat units: a minimum value (close to) B ═ 0 means that the copolymer composition is present as a diblock polymer sequence (non-zero, since the diblock must have 1 XY or YX diad):

XXXXXXXYYYYYYYYYYYYYYYYYYYYYYYYYYYY

the value of B ═ 1 represents a random copolymer (or "statistical copolymer"), such as, for example:

XYYYYYYYYXXXYYYYYYYYYYYXYYYYYYXXYYY

maximum value of B, B_max＝1/[Y]Representing perfectly alternating copolymers (each X (minor component) is surrounded by Y (major component; there are no X blocks or XX diads in the polymer chain),

XYYYYYYXYYYXYYYYYYYXYYXYYYYYXYYYXYY

wherein [ Y ] is]Is the molar fraction of polyester monomer units (e.g., when X: Y is 1: 4 or 20: 80, B is_max1.25). That is, the mole fraction of X is 0.2 and the mole fraction of Y is 0.8; 1/0.8 ═ 1.25).

For a composition comprising two perfectly alternating monomers X and Y ([ X ]]＝[Y]0.5) wherein only XY and YX diads (equal amounts) are present, thus [ XY ] and]＝[YX]0.5, the highest possible B occurs_max

XYXYXYXYXYXYXYXYXYXYXYXYXYXYXYXYXYX

From equation 1:

B＝([XY]+[YX])/(2[X][Y])＝(0.5+0.5)/(2*[0.5]*[0.5])＝1/0.5＝2

and:

B_max＝1/[Y]＝1/0.5＝2

for copolyester polycarbonates made by the transesterification of polyester Polymers (PET) and polycarbonate Polymers (PC), the secondary reactions (e.g., CO in the carbonate units)₂Loss), the resulting copolymer (PC/PET) is not an ideal bipolymer. The definition of index B is modified to accommodate side reactions while retaining the same physical meaning as described above. The new definition is illustrated using the PC/PET transesterification as an example (FIG. 2).

Wherein X and Y are the two structural units of the copolymer (BPA carbonate comonomer and ethylene terephthalate monomer, respectively). Due to the presence of two side reactions, by¹³Five doublets were detected by C NMR: XX, XY, X' Y, YX, YY. With an additional diad X' Y (ether bond) derived from CO₂Loss is introduced. From¹³From the C point of view, especially the carbon atoms traced as described below, another side reaction (loss of ethylene carbonate) changes only the core-adjacent XY diad into the same core-adjacent fragment as that of the YX diad, so no new diad is introduced. Brackets indicate the molar fraction of structural units or diads, and they satisfy the condition: [ X' + X]+[Y]1 and [ XX ]]+[XY]+[X’Y]+[YX]+[YY]＝1。

FIG. 3 shows representative quantitation of PC/PET copolymer¹³C NMR spectra and detailed peak assignments. Due to the quantitative nature of the NMR spectra, the peak intensity (I) is strictly proportional to the number of structural units or diads observed.

When the comonomer units derived from PC units X and X' are considered, the total amount of PC comonomer units is represented as N_X+X’. In fig. 3, carbon assignments 8, 8 ', 16, 17, 18, and 19 are unique to the PC fragment (X or X') and account for 8 carbons of the core PC fragment (8 carbons from two phenyl rings, where these 8 carbon atoms are bonded only to 2 other phenyl ring carbon atoms and one phenyl ring hydrogen atom). These carbons are all assigned to the carbon numbers D, E and F in FIG. 3¹³C NMR peaks, and these¹³The C NMR peaks respectively have a peak intensity I_D、I_EAnd I_F. Thus, the total amount of PC comonomer units N_X+X’＝(I_D+I_E+I_F)/8

Similarly, when considering comonomer units derived from PET units Y, the total amount of PET units is represented as N_Y. In fig. 3, carbon assignments 1 (or 1 ' or 11), 2 (or 2 ' or 2 ") and 3 (or 3 ' or 3") are unique to PET fragment Y and account for 8 carbons of the core PET fragment (6 phenyl carbons and two carbonyl carbons attached to the phenyl ring). These carbons are all assigned to the numbers A, B and C in FIG. 3¹³C NMR peaks, and these¹³The C NMR peaks respectively have a peak intensity I_A、I_BAnd I_C. Thus, the total amount of PET monomer units N_Y＝(I_A+I_B+I_C)/8

From N_X+X’And N_YCan calculate the mole fractions of PC and PET:

similar to the above, the XY diad has a single unique assignment to carbon 20 in fig. 3¹³CNMR carbon resonance (with peak intensity I)₂₀) And represents only one carbon atom of the XY diad.

Amount of XY diad N_XY＝I₂₀

Carbon partitions 12, 15 and 19 are unique to the X' Y fragment and represent 4 carbons in the fragment.

Amount of X' Y diad N_X’Y＝(I₁₂+I₁₅+I₁₉)/4

Amount of YX diad N_YX＝I₁₁

XX diads have a single unique assignment to carbon 10 in FIG. 3¹³C NMR carbon resonance (with Peak intensity I)₁₀) And represents only one carbon atom in the XX diad.

Accordingly, the amount of XX diad N_XX＝I₁₀

Amount of YY diad N_YY＝N_Y-(N_XY+N_X’Y+N_YX)/2＝(I_A+I_B+I_C-4*I₂₀-I₁₂-I₁₅-I₁₉-4*I₁₁)/8

From N_XY、N_X’YAnd N_YxThe molar fraction of diads can be calculated:

the B value of the copolymer can be calculated by substituting the mole fractions from equations (3) - (7) into equation (2) (equations 5, 6, 7 give the components of the numerator of equation 2; and equations 3 and 4 give the components of the denominator of equation 2).

For copolyesters containing 75% by weight of PET, resins having a B value of greater than 0.88, preferably greater than 0.90, absorb CO as blowing agent₂Will produce a foamed article. Many samples of the transesterified PET/PC resin have been produced using batch Haake (Haake) mixing bowl experiments and continuous pilot line runs, resulting in a B value of about 0.36 (see, e.g., table 3) when no catalyst is used for the copolyester containing 75% by weight PET, and ranging from 0.51 to 1.25 (table 3) for the same system when a catalyst is used.

The B value merely characterizes the degree of randomness (or blockiness) of the distribution of the comonomer along the copolymer chain. The block length distribution that dominates the foamability of the copolymer is influenced by B and the copolymer composition. Defined using B in equation (2), B [ X + X']Is a general indicator for characterizing foamability of PC/PET copolymer, wherein [ X + X']Is the mole fraction of PC comonomer and residues in the copolymer. Regardless of composition, typically B [ X + X']Resins greater than 0.18, preferably greater than 0.20 and more preferably greater than 0.22 absorb CO as a blowing agent₂Will yield a foamed article (see examples of four different compositions of copolymers in table 1).

In certain embodiments, the invention described herein relates to:

a copolyester, copolyesterpolycarbonate or copolyesterpolyether comprising different polyester units, or comprising polyester units and polycarbonate or polyether units, or both, and optionally further comprising one or more coupling agents, and characterized by having (i) polymerized units of one or more aromatic diacid monomers; (ii) polymerized units of ethylene glycol, propylene glycol, butylene glycol, cyclohexanedimethanol, isosorbide or spiroglycol, or combinations thereof, in a total of 10 to 40 mole%; (iii) measured from the inflection point of the second heating of the DSC curve at a Tg between 85 ℃ and 125 ℃ using a heating/cooling rate of 10 ℃/min; and (iv) exposure to 1000psi CO at 135 deg.C₂Has a heat of fusion, Δ H, of not more than 10J/g after 4 hours of hydrostatic pressure of (A)_mA peak value.

As previously mentioned, crystalline and semi-crystalline polyester polymers cannot be easily foamed to produce low density foams, and high temperatures are required to prevent recrystallization of the material when the gas expands to produce the foam. The methods discussed herein reduce or remove the crystallinity of a polymer by disrupting the successive repeating polyester structural units. Because no crystallization needs to be overcome, amorphous copolyesters can be foamed at lower temperatures (above the glass transition temperature) where the melt strength is reasonable. Disclosed herein is a process for directly converting semi-crystalline PET (optionally, some or all of which may be recycled PET) into an amorphous copolyester, such as, for example, a mixed polyester copolyester, a copolyester polycarbonate, or a copolyester polyether, and also disclosed is a composition to produce a foamable copolyester polymer.

Disclosed herein is a method of forming a foamable copolyester, copolyester polycarbonate, or copolyester polyether described herein, the method comprising: (i) melting a blend of at least two polymers selected from a first polyester polymer and one or more other polymers selected from one or more polycarbonate polymers and one or more other polyester polymers, or a combination thereof, and in the presence of a transesterification catalyst and optionally a chain coupling agent; (ii) maintaining the temperature above 200 ℃ for at least 3 minutes, optionally with mixing; (iii) optionally, collecting at least a portion of any ethylene carbonate produced; and (iv) cooling to produce a solid copolymer.

The starting polyester or one of the starting polyesters may be polyethylene terephthalate (PET). The starting polyethylene terephthalate (PET) may be commercially available, for example as from Muehlstein, a subsidiary of Ravago, Allonto, Belgium8080, a step of; or may be obtained as a solid recycled polyester, such as recycled PET, for example from Reterra Plastics (Houston Reterr, Tex.), Polyquest Inc. (Dalton, south Carolina, USA), Circular Polymers (Lincoln, Calif., USA) or Evergreen Plastics (America)Cleaded, ohio). Alternatively, the one or more starting polyesters may be synthesized by methods well known in the art (see above). Glycol-modified Polyesters (PETG) or other polyesters such as poly (trimethylene terephthalate) (commonly known as PTT or poly (trimethylene terephthalate)), poly (butylene terephthalate), poly (cyclohexanedimethanol terephthalate), poly (spiroglycol terephthalate), poly (isosorbide terephthalate), polyethylene furan acid (PEF), poly (propylene furan acid) or other furan acid ester based polyesters may be used in partial or complete replacement for semi-crystalline PET. Similarly, the polycarbonate polymers may be commercially available, for example from Covestro AG (Lewakusen, Germany)3158; or from Trinseo corporation (Burwen, Pa., USA)1060 DVD or1080 DVD; or 17-22MF (Premier Plastic resins), or are available as solid recycled polycarbonates, such as Opticabs PC from Star Plastics, Inc. (Lavenwood, Calif.) or from The Materials Group (Rockford, Mich.); or, alternatively, may be synthesized by known methods. High Tg polyesters (e.g. polyester)GX100 or FX200, available from Eastman Chemical, Kingsport, Tenn, may be used to partially or fully replace polycarbonate.

Polyesters, such as poly (ethylene terephthalate), are melted to a temperature above their crystalline melting temperature and blended with polycarbonate (preferably aromatic polycarbonate, such as, for example, bisphenol a polycarbonate) or other polyesters plus an optional third polymer, which may be a polyester or polycarbonate type polymer. Optionally, a chain coupling agent such as pyromellitic dianhydride, 3- (trimethoxysilyl) propyl methacrylate, or others known in the art may be added. The transesterification catalyst is added to the melt blend as a physical blend with the solid or molten polymer or as a concentrate in one of the polymers. As described herein, the polymers are conveniently mixed and reacted in the melt phase, which is also applicable to extrusion processes already common in the art (e.g., in the production of foamed insulation boards). Mixing and reaction may alternatively occur in solution, although few solvents form good solutions of these polymers, and most are considered environmentally unacceptable solvents. Such solvents (and partial solvents) may include, but are not limited to, 60/40 blends of phenol/1, 1, 2, 2-tetrachloroethane, fluorinated alcohols such as hexafluoroisopropanol, trifluoroacetic acid, o-chlorophenol, m-cresol, chloroform, and dichloromethane.

The present inventors have found that in the absence of a catalyst, the polymer is not sufficiently transesterified to produce a new copolymer which does not crystallize when the blowing agent is dissolved therein. Thus, when polyester polymers (or polyester and polycarbonate polymers) are simply blended ("polymer mixture", "polymer blend" or "mixed composition") in the absence of a catalyst, the result is a blend of starting polymers or polymers with significant "blockiness" and cannot be used to produce stable foams.

Suitable catalysts for the transesterification reaction include those known in the art, in particular organometallic complexes, such as, for example, titanium (IV) tetrabutoxide, Ti (OBu)₄Titanium (IV) tetraisopropoxide, Ti (OiPr)₄Cerium (III) acetate, Ce (OAc)₃Ytterbium (III) acetylacetonate, Yb (acac)₃And calcium (II) acetate in combination with antimony (III) oxide (Ca (OAc)₂/Sb₂O₃) And tin organometallic complexes, such as monobutyl tin oxide (MBTO), dibutyl tin oxide (DBTO), dioctyl tin oxide (DOTO), some of which are available under the trade nameObtained under catalyst (PMC Org of Larrel mountain, N.J. USA)anomaltallix). Suitable use levels may vary from catalyst to catalyst, but are typically from 50ppm to 10,000ppm, or from 1,000ppm to 5,000ppm, or from 1,500ppm to 3,000ppm (parts by weight of catalyst per million parts by weight of total polymer present in the reaction).

In certain embodiments, and as is readily understood by one of ordinary skill in the art, the processes described herein can be carried out in any reactor known in the art capable of withstanding the conditions of the process. For example, but not by way of limitation, the reactor may comprise one vessel or more than one vessel. The polymer components are mixed to substantially disperse the minor phase and to facilitate transesterification. In one embodiment, and as described in example 1, the components are mixed in the melt phase in a haake blender (e.g., a seemefly scientific haake melt rheometer). In another embodiment, and as described in example 2, the components are mixed in the melt phase in an extruder apparatus, such as a twin screw extruder. Optionally, other desired additives may be added to the haake blend or extruder blend and mixed with the melt phase polymer or, preferably, they are added later. Such other additives, in any combination, may include, for example, pigments, clays, colorants, lubricants, acid scavengers, infrared attenuating agents, nucleating agents, flame retardants, and/or fillers/agents that increase gas permeability. The polymer blend (with any additives) is given approximately 1-5 minutes at 200-280 c before quenching and pelletizing.

The transesterification reaction may be carried out without the use of elevated pressure, although elevated pressure may be used (with similar effect to elevated temperature). Practical considerations may influence the specific choice of transesterification reaction time and temperature conditions, with lower temperatures requiring longer periods of time to carry out the desired degree of reaction to sufficiently reduce the amount of "blockiness" in the resulting copolyester to foam the copolyester product (see, e.g., fig. 1). In certain embodiments, the transesterification reaction may be conducted at a temperature (c) of 150, 160, 170, 180, 190, 200, 205, 210, 215, 220, 225, 230, 235, 240, 245, 250, 255, 260, 265, 270, 275, 280, 285, 290, 295, 300, 310, 320, 330, or 350. The time (minutes) may be 0.5, 1, 2, 3, 4, 5, 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, 120, 130, 140, or 150, or more. Each of the foregoing numbers (for temperature or time) may be preceded by the word "about", "at least about", or "less than about", and any of the foregoing numbers may be used alone to describe open ranges or in combination to describe closed ranges. Suitable reaction temperatures and times may be 200 ℃ to 300 ℃ for 5 minutes to 60 minutes. Preferred reaction conditions (using catalyst) are 230 ℃ to 275 ℃ for 5 minutes to 30 minutes (an initial time of about 2 minutes at 275 ℃ to ensure that the PET is in the melt phase).

Although by-product Chemicals (CO) are discussed in the open literature₂Ethylene glycol and ethylene carbonate), most of the prior art has focused on processes that completely avoid side chemical reactions. As disclosed herein, the Tg of the final polymer is increased by selecting the catalyst and reaction temperature to selectively promote specific side reactions to preferentially promote the loss of ethylene glycol. Thus, higher PET loadings can be used in blends without the intended Tg limitation. Preferred catalysts which particularly promote ethylene glycol loss to increase the Tg of the final polymer are DBTO, DOTO, Ti (OBu)₄And Ti (O)ⁱPr)₄，

In one embodiment, a foamable composition is provided comprising a copolyester, copolyesterpolycarbonate or copolyesterpolyether as disclosed herein and a blowing agent. In certain embodiments, the blowing agent is selected from one or more physical blowing agents, such as pentane, hydrofluoroolefins, carbon dioxide, nitrogen, oxygen, water, alcohols (such as methanol and ethanol), ketones (including acetone), ethers (such as dimethyl ether or diethyl ether), halogenated hydrocarbons (such as vinyl chloride or methylene chloride), or olefins (such as pentene), or combinations thereof. Examples of suitable chemical blowing agents are azides such as Azodicarbonamide (AZNP), 5-phenyltetrazole (5PT), or a mixture of citric acid and bicarbonate.

In another embodiment of the present invention, there is provided solid foamable beads made from any of the foamable compositions disclosed herein.

Further, the present invention provides a foamed article made by: (a) extrusion foaming of any foamable composition disclosed herein, or (b) expansion of the solid foamable beads described above.

In certain embodiments, a method of forming a copolyester, copolyester polycarbonate, or copolyester polyether copolymer disclosed herein is disclosed, the method comprising: (i) melting a blend of at least two polymers selected from a first polyester polymer and one or more other polymers selected from one or more polycarbonate polymers and one or more other polyester polymers, or a combination thereof, and in the presence of a transesterification catalyst and optionally a chain coupling agent; (ii) maintaining the temperature above 200 ℃ and below 330 ℃ for at least 3 minutes and not more than 180 minutes, optionally with mixing; and (iii) optionally, collecting at least a portion of any ethylene carbonate produced; and (iii) cooling to produce a solid copolymer.

In certain embodiments, at least a portion of the polyester units in the copolymer are derived from recycled polyethylene terephthalate.

In certain embodiments, reduced pressure is used to remove volatile materials.

In certain such embodiments of the process, the weight ratio of the first polyester polymer to the one or more other polymers may be 35: 65, 40: 60, 42: 58, 44: 56, 46: 54, 48: 52, 50: 50, 52: 48, 54: 46, 56: 44, 58: 42, 60: 40, 62: 38, 64: 36, 66: 34, 68: 32, 70: 30, 72: 28, 74: 26, 75: 25, 76: 24, 78: 22, 80: 20, 82: 18, 84: 16, 86: 14, 85: 15. Each of the foregoing numbers may be preceded by the word "about", "at least about", or "less than about", and any of the foregoing numbers may be used alone to describe open ranges or in combination to describe closed ranges. For example, the weight ratio of the first polyester polymer to the one or more other polymers can be at least about 50: 50, from about 50: 50 to about 80: 20, or from about 50: 50 to about 75: 25, or less than about 85: 15. As noted above, one or more other polymers may be present, which may include one or more other polyester polymers. Where one or more polyester polymers are included in the other polymer types, separate embodiments exist wherein the weight ratio of the total amount of all polyester polymers to polycarbonate polymer can be 35: 65, 40: 60, 42: 58, 44: 56, 46: 54, 48: 52, 50: 50, 52: 48, 54: 46, 56: 44, 58: 42, 60: 40, 62: 38, 64: 36, 66: 34, 68: 32, 70: 30, 72: 28, 74: 26, 75: 25, 76: 24, 78: 22, 80: 20, 82: 18, 84: 16, 85: 15. Each of the foregoing numbers may be preceded by the word "about", "at least about", or "less than about", and any of the foregoing numbers may be used alone to describe open ranges or in combination to describe closed ranges. For example, the weight ratio of the total amount of all polyester polymers to polycarbonate polymer may be at least about 50: 50, from about 50: 50 to about 80: 20, or from about 50: 50 to about 75: 25, or less than about 85: 15.

In certain embodiments, the product copolyester copolymers produced by the processes disclosed herein are disclosed.

As mentioned above, some building blocks may lose fragments of a unit, but the remaining fragments (residues) of the building blocks are still present in the polymer chain. In the following ratios, the corresponding building blocks include their residues. In certain embodiments, the molar ratio of polyester structural monomer units to the one or more comonomer structural units (polycarbonate or other polyester structural units) in the copolyester, copolyesterpolycarbonate or copolyesterpolyether is 45: 55, 46: 54, 48: 52, 50: 50, 52: 48, 54: 46, 56: 44, 58: 42, 60: 40, 62: 38, 64: 36, 66: 34, 68: 32, 70: 30, 72: 28, 74: 26, 75: 25, 76: 24, 78: 22, 80: 20, 82: 18, 84: 16, 86: 14, 88: 12, 90: 10. Each of the foregoing numbers may be preceded by the word "about", "at least about", or "less than about", and any of the foregoing numbers may be used alone to describe open ranges or in combination to describe closed ranges. For example, the molar ratio can be at least about 50: 50, from about 50: 50 to about 80: 20, or from about 50: 50 to about 75: 25, or less than about 85: 15. As noted above, one or more types of comonomer structural units may be present, which may include other polyester structural unit types or polycarbonate structural units. In the case where more than one comonomer structural unit type is present, the ratio of the respective comonomer structural unit types (ratio of comonomer a to comonomer B) is not particularly limited in any way.

In certain embodiments, the molar ratio of polymerized structural units of polyethylene terephthalate (PET) or PET residues to one or more Polycarbonate (PC) structural units or PC residues (in polymerized form) in the copolyesterpolycarbonate (or copolyethers) is 45: 55, 46: 54, 48: 52, 50: 50, 52: 48, 54: 46, 56: 44, 58: 42, 60: 40, 62: 38, 64: 36, 66: 34, 68: 32, 70: 30, 72: 28, 74: 26, 75: 25, 76: 24, 78: 22, 80: 20, 82: 18, 84: 16, 86: 14, 88: 12, 90: 10. Each of the foregoing numbers may be preceded by the word "about", "at least about", or "less than about", and any of the foregoing numbers may be used alone to describe open ranges or in combination to describe closed ranges. For example, the molar ratio can be at least about 50: 50, from about 50: 50 to about 80: 20, or from about 50: 50 to about 75: 25, or less than about 85: 15. As noted above, one or more types of comonomer polycarbonate structural units (or residues thereof) may be present. In the case where there is more than one comonomer polycarbonate type, the ratio of the respective comonomer polycarbonate unit types (ratio of comonomer a or residues thereof to comonomer B or residues thereof) is not particularly limited in any way. In one such embodiment, the copolymer comprises only one type of polycarbonate comonomer (in polymerized form), which is a bisphenol a type polycarbonate structural unit or residue thereof. Furthermore, as mentioned above, the polymeric structural units of the Polycarbonate (PC) in the polymer may remain intact (as polycarbonate monomer in polymerized form), or some or all of these structural units may be present as residual fragments (residues) which are responsible for the loss of CO from the carbonate functions₂The molecule is retained.

In certain embodiments, the foamable copolyester, copolyestercarbonate or copolyethercopolymer has a total of from 10 to 40 mole% polymerized structural units of one or more aliphatic diols, where mole% is the sum of the moles of polymerized structural units of the one or more aliphatic diols in the copolymer, expressed as a percentage of the total moles of copolymerized structural units comprising the copolymer. The mole% of the aliphatic diol can be determined by NMR of the transesterification reaction product. In certain embodiments, the sum (in mole%) of the polymerized structural units of the one or more aliphatic diols of the foamable copolyester, copolyestercarbonate or copolyethercopolymer is 10, 15, 20, 22, 24, 26, 28, 30, 32, 34, 36, 38, 39, 40. Each of the foregoing numbers may be preceded by the word "about", "at least about", or "less than about", and any of the foregoing numbers may be used alone to describe open ranges or in combination to describe closed ranges. Suitable mole% of the polymerized structural units of the one or more aliphatic diols for the foamable copolyester may be 15 to 40 mole%, or 20 to 39 mole%, or 20 to 38 mole%. In one embodiment, the mole% of the aliphatic diol is 25 to 38 mole%.

In certain embodiments, the foamable copolyester, copolyestercarbonate or copolyetherester copolymer has a glass transition temperature, Tg (deg.C), of 80, 85, 90, 95, 98, 100, 102, 105, 110, 115, 120, 125 or 130. Each of the foregoing numbers may be preceded by the word "about", "at least about", or "less than about", and any of the foregoing numbers may be used alone to describe open ranges or in combination to describe closed ranges. Suitable Tg's for the foamable copolyester may be from 80 ℃ to 125 ℃, or from 85 ℃ to 120 ℃, or from 90 ℃ to 115 ℃. In embodiments, the Tg is from 95 ℃ to 110 ℃.

In certain embodiments, the foamable copolyester, copolyestercarbonate or copolyethercopolymer has a melting enthalpy of 0, 0.1, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, (. DELTA.Hm "before foaming), (J/g). Each of the foregoing numbers may be preceded by the word "about", "at least about", or "less than about", and any of the foregoing numbers may be used alone to describe open ranges or in combination to describe closed ranges. The foamable copolyester is suitably at a Δ Hm, prior to foaming, of no more than 15J/g, or no more than 10J/g, or it may be from 0J/g to 15J/g, or from 0J/g to 10J/g, or from 0.1J/g to 15J/g, or from 0.1J/g to 10J/g. Preferably, it is 0J/g or not more than 5J/g.

In certain embodiments, the foamable copolyester, copolyestercarbonate or copolyethercopolymer has a melting or crystallization enthalpy of 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, a "post-foaming Δ Hm", (J/g). Each of the foregoing numbers may be preceded by the word "about", "at least about", or "less than about", and any of the foregoing numbers may be used alone to describe open ranges or in combination to describe closed ranges. Δ Hm after foaming means exposure to CO₂Is measured after the hydrostatic pressure of (a). The foamable copolyester after foaming suitably has a Δ Hm of no more than 15J/g, or no more than 12J/g, or no more than 10J/g, or it may be from 0J/g to 15J/g, or from 0J/g to 12J/g, or from 0J/g to 10J/g, or from 0.1J/g to 15J/g, or from 0.1J/g to 10J/g. Preferably, it is 0J/g, or not more than 10J/g, or not more than 5J/g.

In certain embodiments, the copolyester, copolyestercarbonate or copolyethercopolymer, for a polyester having a ratio of polyester: polyesters in polycarbonate structural units or copolymers: copolymers having a molar ratio of (polycarbonate + polyether) structural units of from 65: 35 to 85: 15 have a Koenig B value (dimensionless) of greater than 0.90. Within the stated molar ratio ranges, the copolyester, copolyesterpolycarbonate or copolyesterpolyether copolymer has a Koenig B value (dimensionless) of 0.8, 0.9, 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2.0. Each of the foregoing numbers may be preceded by the word "about", "at least about", or "less than about", and any of the foregoing numbers may be used alone to describe open ranges or in combination to describe closed ranges. For example, the B value may be greater than 1.0, or it may be from 0.9 to 2.0, or from 1.0 to 2.0, or from 1.1 to 1.7.

In certain embodiments, the copolyester, copolyestercarbonate or copolyethercopolymer has a B [ X ] value or B [ X + X '] greater than 0.20, where B is the Koenig B value of the randomness of the copolymer, [ X ] is the mole fraction of comonomer polycarbonate and/or polyether structural units in the copolymer, and [ X + X' ] is the mole fraction of comonomer polycarbonate and/or polyether structural units, including any units comprising a residue fraction thereof, in the copolymer. The copolyester, copolyesterpolycarbonate or copolyesterpolyether copolymer has a B [ X ] or B [ X + X' ] value (dimensionless) of 0.18, 0.20, 0.22, 0.24, 0.26, 0.28, 0.30, 0.35, 0.40, 0.45, 0.50, 0.55, 0.60, 0.65, 0.70, 0.75 or 0.80. Each of the foregoing numbers may be preceded by the word "about", "at least about", or "less than about", and any of the foregoing numbers may be used alone to describe open ranges or in combination to describe closed ranges. For example, the B [ X ] or B [ X + X' ] value may be greater than 0.22, or it may be from 0.18 to 0.80, or from 0.20 to 0.75, or from 0.22 to 0.75, or from 0.25 to 0.70.

The present invention relates to copolyester polymers prepared from one or more virgin or recycled polyesters such as PET and/or PETG and one or more virgin or recycled polycarbonate polymers such as, for example, bisphenol a, wherein the resulting copolyester has a number of unexpected attributes. For example, a foamable polyester (e.g., PET) -based copolymer can be foamed to produce less than 0.1g/cm³In contrast to other prior art or commercial products based on PET (virgin or recycled). This allows the use of these starting materials, in particular PET, in a range of product fields and applications (discussed below), which previously could not be used with PET or PETG (virgin or recycled).

Because of the chemical structure of PET, it is flammable compared to polystyrene (the primary polymer used in thermoplastic insulating foams), amorphous form polyester-based foam articles (virgin or recycled and whether derived from PET/PC or from PETG/PC) are less flammable and do not require additional flame retardants to meet the Limiting Oxygen Index (LOI) of the united states. The flame retardant properties of such foams are sufficient to pass building and construction code requirements without the need for flame retardant additives in the foam formulation. Furthermore, it is expected that the test will pass German B2 without the need for flame retardant additives. Even for more stringent building specifications, the use of PET as the base resin in the copolyester polymer for the insulating foam eliminates the need for halogenated flame retardants, and in some cases, non-halogenated flame retardants may instead be added to meet the stringent building specifications.

The copolyesters of the invention have increased blowing agent solubility (for many blowing agents, including CO₂1-chloro-3, 3, 3-trifluoropropene (HFO 1233zd), cyclopentane, acetone, and methanol), such that a wide range of extrusion or expansion processes can be used to produce foam articles.

The products of the invention may be used in a variety of fields and applications, for example but not limited to as packaging or construction materials, such as for example building insulation or air sealant applications, cushioning packaging, 3-D printing, thermoforming and the like.

Some embodiments disclosed herein are set forth in the following clauses, and any combination of these clauses (or portions thereof) may be made to define an embodiment.

Clause 1: a copolyester, copolyesterpolycarbonate or copolyesterpolyether copolymer comprising different polyester units, or comprising polyester units and polycarbonate or polyether units, or both, and optionally further comprising one or more coupling agents, and characterized by having:

(i) polymerized units of one or more aromatic diacid monomers;

(ii) a total of 10 to 40 mole percent of polymerized units of one or more aliphatic diols, wherein mole percent is the sum of the moles of polymerized units of the one or more aliphatic diols in the copolymer, expressed as a percentage of the total moles of copolymerized units comprising the copolymer;

(iii) a primary Tg between 85 ℃ and 125 ℃ measured from the inflection point of the second heating of the DSC curve using a heating/cooling rate of 10 ℃/min; and

(iv) exposure to 1000psi at 135 deg.C CO₂Has a heat of fusion, Δ H, of not more than 10J/g after 4 hours of hydrostatic pressure of (A)_mA peak value.

Clause 2: the copolyester, copolyesterpolycarbonate or copolyesterpolyether copolymer of clause 1, having a B [ X ] or B [ X + X '] value of 0.20 or more, wherein B is the Koenig B value of the randomness of the copolymer, [ X ] is the molar fraction of comonomer polyester structural units or comonomer polycarbonate and/or polyether structural units in the copolymer, and [ X + X' ] is the molar fraction of comonomer polyester structural units or comonomer polycarbonate and/or polyether structural units, including any units comprising a residue segment thereof, in the copolymer. In one embodiment, the copolymer has a BX or BX + X' ] value greater than 0.22.

Clause 3: the copolyester, copolyesterpolycarbonate or copolyesterpolyether copolymer of clause 1, for a polyester having a copolymer of: polyesters in polycarbonate structural units or copolymers: copolymers having a molar ratio of (polycarbonate + polyether) structural units of from 65: 35 to 85: 15 have a Koenig B value of greater than 0.90.

Clause 4: the copolyester, copolyesterpolycarbonate or copolyesterpolyether copolymer of any of clauses 1 to 3 wherein the one or more aromatic diacid monomers are selected from phthalic acid, terephthalic acid, isophthalic acid or 2, 5-furandicarboxylic acid.

Clause 5: the copolyester, copolyesterpolycarbonate or copolyesterpolyether or copolymer of any of clauses 1 to 4, further comprising one or more coupling agents. In one embodiment, the one or more coupling agents is pyromellitic dianhydride.

Clause 6: the copolyester, copolyesterpolycarbonate or copolyesterpolyether or copolymer of any of clauses 1 to 5 wherein at least a portion of the polyester units in the copolymer are derived from recycled polyethylene terephthalate.

Clause 7: the copolyester, copolyesterpolycarbonate or copolyesterpolyether copolymer of any of clauses 1 to 6 wherein the one or more glycols is selected from ethylene glycol, 1, 2-propylene glycol, 1, 3-propylene glycol, butylene glycol, cyclohexanedimethanol, isosorbide and spiroglycol. In one embodiment, the one or more glycols is ethylene glycol.

Clause 8: the copolyester, copolyesterpolycarbonate or copolyesterpolyether copolymer of any of clauses 1 to 7, wherein the copolyester, copolyesterpolycarbonate or copolyesterpolyether comprises at least 7 mole% of polymerized units of bisphenol a.

Clause 9: the copolyester, copolyesterpolycarbonate or copolyesterpolyether copolymer of any of clauses 1 to 8, wherein the molar ratio of polyester polymer structural units to the sum of polycarbonate polymer structural units and polyether polymer structural units is from 40: 60 to 85: 15 or from 50: 50 to 80: 20.

Clause 10: a foamable composition comprising the copolyester, copolyesterpolycarbonate or copolyethercopolymer of any of clauses 1 to 9 and one or more blowing agents.

Clause 11: the foamable composition of clause 10, wherein the blowing agent is selected from one or more pentanes, one or more hydrofluoroolefins, carbon dioxide, nitrogen, oxygen, water, alcohols, ketones, ethers, halogenated hydrocarbons or olefins, or combinations thereof.

Clause 12: the foamable composition of clause 10, wherein the blowing agent is selected from one or more chemical blowing agents.

Clause 13: the foamable composition of any of clauses 10 to 12 further comprising one or more of an immiscible polyolefin, a colorant, a pigment, a filler, a clay, a flame retardant, an infrared attenuating agent, a nucleating agent, a lubricant, an acid scavenger, an antistatic agent, or an antioxidant, or a combination thereof.

Clause 14: a solid foamable bead made from the composition of any of clauses 10 to 13.

Clause 15: a foamed or expanded article obtained from the composition of any of clauses 10 to 13.

Clause 16: a foamed or expanded article made by:

(a) extrusion foaming of the foamable composition of any of clauses 10 to 13, or (b) expansion of the solid foamable beads of clause 14.

Clause 17: the foam or foamed article of clauses 15 or 16, wherein the foam has from 0.01 to 0.1g/cm³The density of (c).

Clause 18: a method of forming the copolyester, copolyesterpolycarbonate or copolyesterpolyether copolymer of any of clauses 1 to 9, comprising:

(i) melting a blend of at least two polymers selected from a first polyester polymer and one or more other polymers selected from one or more polycarbonate polymers and one or more other polyester polymers, or a combination thereof, and in the presence of a transesterification catalyst and optionally a chain coupling agent;

(ii) maintaining the temperature above 200 ℃ and below 330 ℃ for at least 3 minutes and not more than 180 minutes, optionally with mixing;

(iii) optionally, collecting at least a portion of any ethylene carbonate produced; and

(iv) cooled to produce a solid copolymer.

Clause 19: the method of clause 18, wherein the weight ratio of the first polyester polymer to the one or more other polymers is from 40: 60 to 85: 15.

Clause 20: the method of clause 18, wherein the weight ratio of the total amount of all polyester polymers to polycarbonate polymer is from 40: 60 to 85: 15.

Clause 21: the method of any of clauses 18 to 20, wherein reduced pressure is used to remove volatile materials.

Clause 22: the method of any one of clauses 18-21, wherein the method further comprises the step of collecting at least a portion of any ethylene carbonate produced.

Clause 23: the method of any of clauses 18 to 22, wherein the one or more polyester polymers is recycled polyethylene terephthalate.

Clause 24: the copolyester, copolyesterpolycarbonate or copolyetherpolyether copolymer of any of clauses 1 to 9 or 25, wherein at least a portion of the polyester structural units in the copolymer are derived from recycled polyethylene terephthalate.

Clause 25: a copolyester, copolyesterpolycarbonate or copolyesterpolyether copolymer comprising polymerized structural units selected from:

a) one or more aliphatic diols selected from the group consisting of,

b) one or more of the aromatic diacids of the aromatic diacid,

c) one or more of the aromatic diols in the aromatic diol mixture,

d) one or more organic carbonates in a mixture of organic carbonates,

wherein the copolyester copolymer comprises polymerized structural units a + b

The copolyester polycarbonate copolymer comprises polymerized structural units a + b + c + d, and

the copolyester polyether copolymer comprises polymeric structural units a + b + c + optionally d, and further comprises ether functional groups in the polymer backbone;

the copolymer is characterized in that:

i) the polymerized structural units of the one or more aliphatic diols (a) are present in an amount totaling from 15 to 40 mol%, where mol% is the sum of the moles of polymerized structural units of the one or more aliphatic diols in the copolymer, expressed as a percentage of the total moles of polymerized structural units a + b + c + d constituting the copolymer;

ii) a primary Tg between 85 ℃ and 125 ℃ measured from the inflection point of the second heating of the DSC curve using a heating/cooling rate of 10 ℃/min; and

iii) Exposure to 1000psi CO at 135 deg.C₂Has a heat of fusion, Δ H, of not more than 10J/g after 4 hours of hydrostatic pressure of (A)_mA peak value.

Similar examples exist for the copolyester, copolyestercarbonate or copolyethercopolymer of clause 25, as described in the examples in clauses 1-24.

The invention is further defined in the following examples, wherein all parts and percentages are by weight unless otherwise indicated. It should be understood that these examples, while indicating preferred embodiments of the invention, are given by way of illustration only and are not to be construed in any way as limiting. From the above discussion and these examples, one skilled in the art can ascertain the essential characteristics of this invention, and without departing from the spirit and scope thereof, can make various changes and modifications of the invention to adapt it to various usages and conditions.

Examples of the invention

Example 1

Haake blending method for melt ester exchange reaction

In this example, the bulk polymer resin was dried in a forced air convection oven or a vacuum oven according to the manufacturer's recommendations. The moisture content was checked by Omnimark 2 high performance moisture analyzer and confirmed to be 0.005% or less. The bulk polymer resin and additives are then physically mixed together and slowly added to a semer fly science haake melt rheometer preheated to at least 10 ℃ above the highest peak softening temperature of the added components. The addition of the polymer resin is carried out at a relatively slow mixer speed (25-50 rpm). Once the resin was completely melted, the catalyst and/or additional additives were added, then the mixer speed was increased to 200rpm and blending was continued for the set time and temperature profile according to the experimental conditions. All blends were carried out under a vigorous dry nitrogen purge carried out at the mixer throat. After the set mixing melt and mixing conditions are completed, the mixed/reacted material is removed and placed inOn the tray, it is allowed to cool until the material can be bagged and stored in a dry box until testing or part manufacturing can begin. Unless otherwise indicated, all percentages are in wt% and pph is "parts per hundred" of total polymer weight.

Example 2

Extruder process for melt transesterification reactions

Example 2a. tandem double single screw extrusion system.

Continuous melt transesterification is carried out by feeding the material at a rate of 75 to 150lb/hr to a co-rotating twin screw extruder (screw diameter 40mm, length to diameter ratio L/D45.5: 1). The molten polymer mixture leaving the twin-screw extruder was fed directly to a side-feed single-screw extruder (screw diameter 90mm, 30: 1L/D) followed by an annealing tube/static mixer. The annealing section was 2.25 inches in diameter and 24 inches long, and the static mixer section was 12 inches long, containing four SMX static mixers each 3 inches long. The extrudate was collected by pelletizing under water using a die face pelletizer. The pellet size is in the range of 3-5mm diameter (usually spherical).

Example 2b. tandem double twin screw extrusion system.

The transesterification reactive extrusion was carried out on a tandem twin-screw extrusion system consisting of a first co-rotating twin-screw extruder (TEX 44. alpha. III, manufactured by Japan Steel Works (JSW) ("primary extruder") and a second co-rotating twin-screw extruder (TEX28V, also manufactured by JSW) ("secondary extruder"). Specifically, the 44 α III twin screw extruder had 17 barrels, a screw diameter of 47mm and a screw length to diameter ratio L/D of 59.5, while the TEX28V twin screw extruder had 12 barrels, a screw diameter of 28mm and an L/D of 42. The conveying pipe connecting the TEX44 alpha III twin-screw extruder and the TEX28V twin-screw extruder had a diameter of 22mm and a length of 1592.5 mm. The catalyst is mixed with polyester to obtain a catalyst concentrate with a concentration of 2.5-7 wt%. The polyester was dried in an oven overnight and packaged in aluminum foil bags prior to reactive extrusion. Three loss-in-weight feeders were used to feed two polyesters/resins (e.g., PET and PC) and the catalyst concentrate into the main feed throat of a TEX44 a III twin screw extruder. All feeders and main feed throats were purged with a continuous nitrogen flow. There were 3 vents in the TEX44 α III twin screw extruder, which were connected to a condensing system equipped with two knock-out pots and a vacuum pump. Similarly, the TEX28V twin screw extruder had one rear vent and two wide vents that were connected to a condensing system equipped with a Multitrap tank and another condensing system with cooling coils and a vacuum pump. A high vacuum (at least 28 inches of mercury vacuum) is applied to these condensing systems and the extruder to remove volatiles generated by the transesterification reaction. The polymer melt emerges from a strand die with three holes (4 mm diameter) and is immediately quenched in a water bath and then pelletized.

Example 3

NMR method for determining degradation and randomness factors

Each sample was weighed out in an amount of 0.3g and dissolved in 3.0ml of deuterated chloroform (CDCl) with 5mM chromium (III) acetylacetonate as relaxation agent (relaxation agent)₃) In (1). Trifluoroacetic acid (TFA) (0.05-0.2ml) was also added to help dissolve the polymeric material in the presence of high crystallinity. One-dimensional (1D) quantification¹³The C NMR experiments were performed on a 600MHz Bruker Avance III spectrometer equipped with a 10mm cryoprobe. Quantification of¹³C NMR spectroscopy using single pulse method with inverse gating¹H decoupling, with a total repeat time of 10s and an acquisition time of 1.7 s. The receiver gain was optimized and 1024 scans were recorded to generate sufficient spectral sensitivity for quantitative analysis. The spectral width was set at 250ppm with the frequency center at 100 ppm.

Example 4

DSC method for quantifying crystallinity

The samples were weighed and sealed in aluminum DSC pans. The sample weight of each sample was about 5 to 10 mg. The samples were scanned in a TA Instruments Q2000 DSC (differential scanning calorimeter) with an autosampler with a nitrogen purge of 50 ml/min. The heating rate was 10 ℃/min and a temperature profile between 20 ℃, 280 ℃ and back to 20 ℃ was applied twice for each sample. The scan was analyzed using the Universal Analysis V4.7A software. The key output parameters of the DSC test are the glass transition temperature and temperature of the sample and the enthalpy of fusion and crystallization. CO 2₂The sample analysis before soaking was performed on a second temperature ramp. Exposure to 1000psi CO at 135 deg.C₂After 4 hours of hydrostatic pressure, sample analysis was performed on the first temperature ramp. The glass transition temperature (Tg) was measured as the inflection point of the baseline step transition and reported in degrees celsius. Melting or crystallization enthalpy is measured by linear baseline estimation using peak area and is reported as J/g. Taking into account the nodules of crystalline PETA crystallization enthalpy of 140J/g, it can be estimated that a crystallization enthalpy less than 10J/g will represent a crystallinity of about 7% or less, and a crystallization enthalpy less than 5J/g will represent a crystallinity of less than 4%.

Example 5

Extruder process for expandable beads

The transesterified copolyester is melt blended with one or more physical blowing agents, such as n-pentane, cyclopentane, or 1-chloro-3, 3, 3-trifluoropropene (HFO 1233zd) under pressure (>1000psi) using a single screw extruder that feeds into a mixer where the blowing agent is introduced. The polymer-blowing agent blend is then cooled using additional mixing elements (or heat exchangers) and then exits through a porous die having the desired diameter, such that cylindrical particles (or spherical beads) in the range of 0.5-1mm (diameter) can be produced. The beads can be quenched with water or air.

Example 6

GPC method

The samples were prepared by adding approximately 0.04g of polymer in 20mL of chloroform at ambient temperature and placed on a mechanical shaker overnight. Before injection, the solution was filtered through a 0.2 μm PTFE syringe filter. Using a Waters 2690 pump/autosampler set at 1 mL/min with continuous vacuum degassing, 50 microliters of the solution was injected into a Two Agilent Technology PL gel mixing C column (7.5 mm internal diameter, 300mm length, 5 micron particle size) maintained at 40 ℃. Shodex RI-501EX shows a differential refractive index detector set at 40 ℃ for molecular weight measurement. Narrow MWD PS standards from agilent laboratories were used for molecular weight ranges: 3,740 to 580,000 g/mol. Data were collected and reduced using the agilent technologies Cirrus SEC/GPC software version 3.3. Air.

Example 7

Foamability evaluation method

To evaluate the foamability of the comparative examples and the inventive examples, the samples were compression molded into 1.3mm thick films (25 tons pressure at 180 ℃ C. for 5 minutes). A portion of the pressed film (area about 7mm x 7mm) was placed in a pressure vessel preheated to 125 ℃. The vessel was then pressurized to 1000psi using carbon dioxide and the sample was allowed to soak for 3-4 hours to dissolve the gas into the polymer. The pressure was then released rapidly to cause foaming in the sample. Successful foaming was determined by visual observation of void formation in the polymer sample and a corresponding increase in sample volume of at least 50%.

Example 8

In this example, a copolyester polycarbonate polymer (PC/PET) was prepared by catalytic transesterification starting from the ingredients Polyester (PET) and polycarbonate (bisphenol A). For purposes of defining the ranges for the PC/PET copolyester copolymer compositions and the ranges for the ethylene glycol units included in the present invention, as the PET content in the formulation increases, a series of blends are produced, thereby catalyzing the transesterification reaction to produce copolyesters. B [ X ] in the following table]Is B [ X + X'](meaning that it includes a fragment of the residue of X). And CO₂The loss (mol%) is the loss of CO during the reaction₂Mole% of total PC monomer units.

In Table 1 and tables below, the last column (labeled "batch foam CO)₂") refers to a foamability screening test for thick films of compression molded products that can utilize small scale samples of modified polyester (see" foamability evaluation method "above).

TABLE 1 ranges for PC/PET copolymer compositions and ethylene glycol content in the final copolymer

1. Examples 1-5 virgin PET and virgin PC (Makrolon 5138) were blended in the presence of the indicated catalysts (all catalysts added at a level of 2000ppm) at 275 ℃ for 30 minutes. EG is ethylene glycol; PET is polyethylene terephthalate; pc is a polycarbonate and is a polycarbonate,

wt.% PET is the initial weight% of PET in the blend before transesterification. Initial wt% PC-100-initial wt% PET.

3. The catalyst is as follows: "FASCAT" is monobutyl tin oxide (MBTO); ti (OBu)₄Is titanium (IV) tetrabutoxide.

Based on the results of this series of studies, foamable copolyester products may contain up to 40 mole percent Ethylene Glycol (EG) structural units. The copolyester containing 41 mole% EG structural units (example 1) failed to produce foam under the foaming test conditions. Note that the EG structural unit content is defined as the mol% of EG structural units, expressed as the% of the total number of all structural units in the backbone (in this case, there are 4 structural units in total; 2 structural units are from each starting polymer, PET and PC), and is calculated taking into account any loss of EG. All Tg values are in degrees celsius as measured by the inflection point method (described previously).

Since PET is relatively inexpensive and recycled PET is inexpensive and abundant, it would be desirable to maximize the level of PET in the foamable copolymer. In this example, the starting polymer (80 wt.% PET) of example 1, 80/20 weight ratio failed to foam (higher Δ H after foaming)_mShowed significant crystallinity, about 14% crystallinity, which in turn reflects significant blockiness due to the length of the consecutive repeat units of the PET structural diads), but both samples with an initial weight ratio of 75/25(75 wt.% PET) were successfully foamed, so some further studies focused on the initial 75/25 weight ratio. Δ H after foaming for all successfully foamed samples_mAre all less than 10J/g.

Example 9

In this example, the transesterification reaction (for 75/25 by weight of the PET/PC blend) was stopped at different reaction times. The amount of blockiness in the copolymer is determined by¹³C NMR and evaluate Koenig B values for the monomer distribution in the polymer chain (table 2, and also see fig. 1).

TABLE 2 influence of the extent of reaction on the B value

1. Examples 2a-2f at levels of 2000ppm additionIn the presence of a catalyst, the catalyst is used,different reaction durations (5 minutes up to 30 minutes) were blended at 275 ℃ using 75/25wt. ratio in a blend of virgin PET and virgin PC (Makrolon 5138).

Based on the reaction series shown in table 2, a B value greater than 0.90 was required to sufficiently randomize the original PET repeat units to avoid exposure to CO₂Crystallization during hydrostatic pressure. Therefore, a polymer having a B value of 0.90 or more is considered suitable for foaming. Δ H for four copolyester copolymer products that failed to produce stable foam_m(in CO)₂After exposure) are all greater than 16J/g; Δ H of two copolyester copolymer products to successfully produce stable foam_m(in CO)₂After exposure) are less than or equal to 8.3J/g.

Example 10

In this example, a variety of catalysts were explored and demonstrated to promote the transesterification reaction with PET, resulting in a range of blockiness and final Tg values. The resulting copolyesters were investigated for their ability to produce stable foams under the test conditions described herein (table 3).

TABLE 3 transesterification catalysts and their effect on copolymer blockiness and by-products

1. Examples 6-13 were blended at 230 ℃ for 30 minutes (after initial about 2 minutes of melting the PET at 275 ℃) except for examples 6 and 10, which were blended at 275 ℃ for the entire 30 minutes. All samples used virgin PET, virgin PC (Makrolon 5138) and a total of 2000ppm of the specified catalyst.

2. The catalyst is as follows: "FASCAT" is monobutyl tin oxide (MBTO); ti (OBu)₄Is titanium (IV) tetrabutoxide; ce (OAc)₃Is cerium (III) acetate; ca (OAc)₂Mixed calcium (II) acetate and antimony (III) oxide (SB) in a ratio of virtually 1: 1₂O₃) A catalyst; yb (III) is ytterbium (III) acetylacetonate; DBTO is dibutyltin oxide; DOTO is dioctyltin oxide; and Ti (OBu)₄Is titanium (IV) tetrabutoxide.

Preferred catalyst generationB values greater than 0.90. More preferred are catalysts that promote loss of EG, which results in a higher Tg. Even more preferred are catalysts promoting loss of EG wherein C0₂The loss was less than 50%, as demonstrated by samples 11 and 13.

Example 11

The use of recycled raw materials for formulations will inherently introduce small amounts of ternary or quaternary blends due to contamination from other recycled polymers. In this example, a small amount of a typical regeneration contaminant (at a typical level of contaminant, e.g., 0.05 wt.% or 0.15 wt.%) is intentionally added to the reactant blend mixture prior to catalyzing the transesterification reaction. The effect of contaminants on foaming capacity was evaluated as above (Table 4: reaction conditions are shown in footnotes).

TABLE 4 Effect of potential contaminants in recycled resins on PC/PET copolymers

1. Examples 14-21 were blended using 75 wt.% virgin (V) or recycled (R) PET, 25 wt.% virgin PC (17-22MF or Makrolon 5138), and 2000ppm DBTO as a catalyst at 275 ℃ for 30 minutes.

2. Additives studied as potential contaminants are: PVC, polyvinyl chloride; PE, polyethylene; LDPE, low density polyethylene; PP, polypropylene; PBT, polybutylene terephthalate; and PS, polystyrene.

Examples 14-21 (table 4) show that small amounts of the third polymer (different from the first two) do not significantly affect the ability of the copolyester to produce stable foam, and that such small amounts of contaminant copolymer are within the scope of the present invention. In all cases, the blend performed similarly to its control counterpart without the additive (example 11).

Example 12

In the following samples, the ability to form foamable copolyester copolymers was extended to include terpolymers. Table 5 shows the results for the PET/PETG/PC terpolymer and shows that some PET/PETG/PC terpolymer compositions are capable of producing stable foams. (PETG is glycol-modified polyethylene terephthalate).

TABLE 5 with PETG¹Composition change and terpolymer

PETG is glycol-modified polyethylene terephthalate (e.g., Eastar GN 001).

2. Example 22 was blended at 275 ℃ for 30 minutes using Eastar GN001 and Makrolon 5138 with 2000ppm DBTO as the catalyst.

Examples 26-28 were blended at 275 ℃ for 30 minutes using virgin PET, Eastar GN001 and Makrolon 5138, and 2000ppm FASCAT as catalysts.

Examples 23-25 were made using the 40mm +90mm extruder process described in example 2 using PET, Eastar GN001, Makrolon 3158, and 2000ppm DBTO as catalysts.

Example 13

Table 6 shows the results for the PET/PBT/PC terpolymer and shows that some PET/PBT/PC terpolymer compositions are capable of producing stable foams. (PBT is polybutylene terephthalate).

TABLE 6 compositional variations and terpolymers with PBT

1. Examples 29 and 33 were blended for 30 minutes at 275 ℃ using virgin PET, poly (butylene terephthalate), and Makrolon 5138 and 2000ppm DBTO as catalysts.

Examples 30-32 were made similar to example 29, using only 2000ppm FASCAT as the catalyst.

Example 14

In this example, Table 7 shows the results for the PET/PTF/PC terpolymer and shows that some PET/PTF/PC terpolymer compositions are capable of producing stable foams. (PTF is polyethylene glycol furanoate).

TABLE 7 compositional variations and terpolymers with PTF

1. Examples 34 and 35 were blended at 275 ℃ for 30 minutes using virgin PET, Makrolon 5138, DuPont's PTF, and 2000ppm DBTO as catalysts.

Example 15

In this example, Table 8 shows the use of PET, PC andresults for terpolymers produced by transesterification of terpolymers of FX200 and show that some of these terpolymer compositions are capable of producing stable foams. (FX200 is polyethylene terephthalate modified with 2, 2, 4, 4-tetramethyl-1, 3-Cyclobutanediol (CBDO), which yields a polymer comprising the diols: a copolyester of a polymerized unit mixture of ethylene glycol and 2, 2, 4, 4-tetramethyl-1, 3-cyclobutanediol).

TABLE 8. havingCompositional variations and terpolymers of FX200

1. Examples 36-38 were blended at 275 ℃ for 30 minutes using recycled PET, Tritan FX200, PC (17-22MF) and 2000ppm DBTO as catalysts.

2.FX200 is polyethylene terephthalate modified with 2, 2, 4, 4-tetramethyl-1, 3-Cyclobutanediol (CBDO), which yields a polymer comprising the diols: ethylene glycol and 2, 2, 4, 4-tetraA copolyester of a polymerized unit mixture of methyl-1, 3-cyclobutanediol.

Optional ternary blends are considered to be within the scope of the present invention, including partial or complete replacement of the ethylene glycol repeat units (from the PET component) with other repeat units such as butanediol (from PBT), cyclohexanedimethanol (from PETG) or cyclobutanediol (from Tritan). All of these ternary blends are capable of producing copolyester copolymer compositions that are foamable within the scope of the foam test described herein.

Although the preferred forms of the invention have been disclosed, it will be apparent to those skilled in the art that various changes and modifications can be made which will achieve some of the advantages of the invention without departing from the spirit and scope of the invention. The scope of the invention is, therefore, indicated by the appended claims.

When ranges are used herein for physical properties (e.g., temperature ranges and pressure ranges) or chemical properties (e.g., chemical formulas), it is intended to include all combinations and subcombinations of ranges in a particular embodiment.

The disclosure of each patent, patent application, and publication cited or described in this document is hereby incorporated by reference in its entirety.

Those skilled in the art will appreciate that numerous changes and modifications may be made to the preferred embodiments of the invention and that such changes and modifications may be made without departing from the spirit of the invention. It is, therefore, intended that the appended claims cover all such equivalent variations as fall within the true spirit and scope of this present invention.