High temperature melt processable semi-crystalline poly (aryl ether ketone) containing a (4-hydroxyphenyl) phthalazin-1 (2H)-one comonomer unit

Abstract

Compositions and methods for a melt processable semicrystalline poly(aryl ether ketone) incorporating phthalazinone and 4,4-biphenol as comonomer units are described herein. The polymers are resistant to and insoluble in common organic solvents and liquids as well as in aggressive organic solvents such as chloroform and chlorinated liquids. The polymers are melt processable via techniques such as extrusion, injection molding, and compression molding. The semicrystalline poly(aryl ether ketone) containing phthalazinone comonomer units have properties which make them suitable for manufacturing high temperature resistant molded systems and other articles.

Claims

1. A composition, consisting essentially of a melt processable semicrystalline aromatic polyetherketone polymer according to formula (I): ##STR00011## wherein Cp is a phthalazinone unit of formula (II); ##STR00012## Q is a biphenol unit of formula (III); ##STR00013## Z is an aromatic ketone unit of formula (VI); ##STR00014## x is a value of at least 1; and y is a value of at least 1, wherein x and y are such that the molar ratio of Q to Cp is between about 30/70 and 90/10, wherein the polymer has a glass transition temperature between about 180 C. and 240 C., and wherein the melt processable semicrystalline aromatic polyetherketone polymer has an enthalpy of melting endotherm of between about 5.0 J/g and 26.0 J/g.

2. The composition according to claim 1, wherein x +y =n, wherein in the formula x +y =n, and n is a value such that the polymer composition has an inherent viscosity of at least about 0.5 dL/g.

3. The composition according to claim 1, wherein the polymer comprises a melt temperature between about 310 C. and 376 C.

4. A shaped article formed by extrusion, injection molding, centrifuge molding, blow molding, rotational molding, transfer molding, thermoforming or compression molding, comprising the composition according to claim 1.

5. A composite structure, comprising the composition according to claim 1 and a fibrous substrate.

6. A composite structure, comprising the composition according to claim 1 and a particulate filler.

7. A composite structure, comprising the composition according to claim 1, a fibrous substrate, and a particulate filler.

8. The composition of claim 1, further comprising mineral fillers.

9. The composition of claim 8, wherein the mineral fillers are selected from the group consisting of mica, glass, quartz, and clay.

10. The composition of claim 1, further comprising fibers.

11. The composition of claim 10, wherein the fibers are selected from the group consisting of glass fibers, carbon fibers, polyarylamide fibers, and ceramic fibers.

12. The composition of claim 1, further comprising additives selected from the group consisting of colorants, pigments, thermal stabilizers, and ultra violet stabilizers.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The skilled artisan will understand that the drawings described herein are for illustration purposes only. The drawings are not intended to limit the scope of the present teachings in any way.

(2) FIG. 1 is a stack graph describing the physical characteristics of the polymer family of the present teachings.

(3) FIG. 2 is a graph showing the relationship of mechanical properties to inherent viscosity, and the properties exhibited by the polymers of the present teachings.

DESCRIPTION OF VARIOUS EMBODIMENTS

(4) As referred to in this application, the following definitions and terms are used:

(5) Tg means glass transition temperature.

(6) Tm means the peak temperature at which the melting endotherm is observed.

(7) IV means inherent viscosity. The inherent viscosity of each polymer was measured at 30 C. on a solution of 0.5 g of polymer in 100 cm.sup.3 of solution in 98% sulfuric acid.

(8) H.sub.m means the enthalpy of melting endotherm.

(9) B/P Ratio means the molar ratio (Q/Cp) of 4,4-biphenol to phthalazinone as incorporated into the polymers of the present teachings.

(10) Semicrystalline, as shown in FIG. 1, means a polymer of the present teachings with a B/P ratio between about 30/70 to 90/10, and with a H.sub.m of between about 5 and 26

(11) J/g.

(12) UHTSP means an Ultra High Temperature Semicrystalline Polymer, which is a melt processable polymer exhibiting, inter alia, the following characteristics: a high temperature performance, a high Tg over 180 C., a high Tm that is above 310 C. but less than 380 C., a continuous use temperature greater than or equal to 250 C., a heat deflection temperature (HDT) of 200 C. or higher, and insolubility in polar organic solvents and chlorinated solvents such as chloroform.

(13) A. Composition and Properties

(14) In accordance with the present teachings, the inventors have discovered that the incorporation of 4,4-biphenol as a comonomer unit into poly(aryl ether ketone)s containing a phthalazinone monomer, as described and disclosed herein, can unexpectedly result in a melt processable semicrystalline polymer with a Tg>180 C. that is not soluble in organic solvents such as chloroform. Even with the incorporation of 4,4-biphenol as low as 30 mol %, the resulting poly(aryl ether ketone) is still semicrystalline with a Tg of 230 C., a melt temperature of 316 C., and a melting endotherm of 5.0 J/g. Given the relatively small amount of the 4,4-biphenol comonomer incorporated, such a result is entirely unexpected. Advantageously, this polymer is not soluble in chloroform, and compression molded film has good resistance to organic solvents.

(15) In accordance with the present teachings, it has been discovered that semicrystalline poly(aryl ether ketone) with a high glass transition temperature (Tg) (>180 C.) can be prepared by polymerization of 4,4-difluorobenzophenone with 4,4-biphenol and 4-(4-hydroxyphenyl)phthalazin-1(2H)-one (phthalazinone). These polymers can be processed via melt processes such as extrusion and injection molding. The present teachings comprise, but are not limited to, the following: Semicrystalline poly(aryl ether ketone) containing 4,4-biphenol and a phthalazinone comonomer unit. Semicrystalline poly(aryl ether ketone) containing a B/P ratio of between about 30/70 and about 90/10. Semicrystalline poly(aryl ether ketone) having a Tg from about 185 C. to about 240 C. Semicrystalline poly(aryl ether ketone) having a melting temperature (Tm) from about 310 C. to about 380 C. Semicrystalline poly(aryl ether ketone) containing a phthalazinone comonomer unit that can be melt processed via common techniques such as extrusion or injection molding.

(16) Pursuant to the present teachings, the Tg and melting temperature of crystalline poly(ether ketone)s containing phthalazinone comonomer units can be adjusted with varying levels of incorporation of 4,4-biphenol monomer, and high Tg semicrystalline copolymers are thereby obtained. Examples are set forth below.

(17) The glass transition temperature (Tg), melting temperature (Tm), and enthalpy of melting endotherm (H.sub.m) of each polymer was measured by Differential Scanning Calorimetry (DSC) using a TA Instruments Q-100 DSC machine with a heating rate of 20 C./minutes. The inherent viscosity of each polymer was measured at 30 C. on a solution of 0.5 g of polymer in 100 cm.sup.3 of solution in 98% sulfuric acid.

(18) Incorporation of the biphenyl unit, by substituting 4,4-biphenol for a portion of the phthalazinone in poly(aryl ether ketone) with a phthalazinone unit results in high molecular weight semicrystalline polymers with good ductility 12 (as defined in FIG. 2), which retain high melting temperatures, and which can be further prepared at reaction temperatures of about 360 C. or less. Due to the consistent limitations of the prior art and the molecular size and orientation of 4,4-biphenol, the commercially desirable properties of the polymers described herein are neither anticipated nor expected.

(19) The polymers of the present teachings have, for example, high melting temperatures of about 310 C. or above and 380 C. or less, glass transition temperatures of about 185 C. to 240 C., moderate to good crystallinity that is measured as enthalpy of melting endotherm of the polymers from about 5 J/g to about 26 J/g, as shown in FIG. 1, which can be synthesized with a high molecular weight that is measured as inherent viscosity (IV) of at least 0.7 or higher.

(20) As shown in FIG. 1, which is a stack graph, the polymers of the present teachings 18 are semicrystalline, and comprise a B/P ratio of between about 30/70 through about 90/10, and a H.sub.m of between about 5 and about 26. Those polymers with a B/P ratio less than 30 percent B and/or a H.sub.m less than 5 are amorphous, and those polymers 20 with greater than 90 percent B (4,4-biphenol) are crystalline.

(21) As shown in FIG. 2, polymers of the present teachings 12 have an inherent viscosity of between about 0.5 and about 2.0, and generally exhibit adequate mechanical properties; meaning, the polymers are ductile in nature, as opposed to brittle (lower molecular weight), or have decreased processability (higher molecular weight). Those polymers 14 with an inherent viscosity less than 0.5 are too brittle, and those polymers 10 with an inherent viscosity greater than 2.0, have decreased processability, and cannot be melt processed.

(22) The novel poly(aryl ether ketone) of the present teachings can be characterized as containing the following aryletherketone repeating units:

(23) ##STR00008##

(24) The starting monomers which are used to prepare the poly(aryl ether ketone)s of the present teachings comprise, for example, the following units:

(25) ##STR00009##
where X is fluorine or chlorine.

(26) In various embodiments of the present teachings, the amount of biphenol to prepare the copolymers herein is such that the molar ratio (B/P) of co-monomer biphenol (B) to phthalazinone (P) is from about 30/70 to about 90/10. In some embodiments, the molar ratio is from about 35/65 to about 80/20. In some embodiments, the molar ratio is from about 40/60 to about 70/30, such that the resulting copolymer has a Tg greater than about 180 C., a Tm greater than about 310 C. and less than about 380 C., and a H.sub.m of at least about 5.0 J/g or higher.

(27) In various embodiments of the present teachings, a melt processable polymer comprises an inherent viscosity (IV) of not more than about 2.0 dL/g. In some embodiments, the IV is not more than about 1.5. In some embodiments, the IV is not more than about 1.2. For ease of processing, the IV comprises a range of at least about 0.5 to about 1.1 dL/g. The lower range can be increased to at least 0.7 during processing.

(28) Some examples of melt processable polymers according to the present teachings are characterized by one or more of the following properties: (1) being semicrystalline with a H.sub.m of at least about 5.0 J/g and in some embodiments about 15 J/g or higher, (2) being ductile when compression molded into a film, (3) being resistant to a wide range of organic solvents, and being essentially unaffected after immersion for 24 hours in chloroform at 25 C., without gaining more than about 10% by weight, and (4) having a Tg equal to or greater than about 180 C., and a Tm equal to or less than about 380 C. Because of their unique properties, the polymers of the present teachings are particularly useful for applications that require resistance to both high temperatures and to organic solvents.

(29) The polymers according to the present teachings can be fabricated into any desired shape such as, for example, moldings, films, coatings or fibers. In particular, the polymers are useful for those applications which require a combination of good electrical insulating properties, good resistance to a wide range of chemicals, retention of mechanical properties at high temperatures, good resistance to burning with low emission of toxic fumes, and low smoke density on burning.

(30) The polymers of the present teachings can also include and/or incorporate mineral fillers (e.g. mica, glass, quartz, clay) as well as various fibers (e.g. glass fibers, carbon fibers, polyarylamide fibers, ceramic fibers). The polymers can additionally comprise additives such as colorants, pigments, thermal stabilizers, and ultra violet stabilizers through means well known in the art.

(31) The polymers of the present teachings can be melt blended with one or more other polymers which include but are not limited to polybenzimidazole, polyarylamide, poly-sulfones, polyketones, polyimides, polyetherimides, polyphenylene sulfides, fluoropolymers, polyesters and polycarbonates.

(32) The technical approach to polymerization of the present teachings differs significantly from the art, including the '663 patent to Hay. In contrast to the art, the polymerization herein is carried out in a non-polar solvent, and the resulting polymers are semicrystalline. Moreover, the use of 4,4-biphenol as a comonomer is not reported in the art. In addition, the present teachings disclose polymerization reactions conducted at significantly higher temperatures, generally between about 280 C. and about 320 C. In contrast, polymers containing a phthalazinone moiety currently reported in the art are processed at temperatures of 225 C. or less. These differences in polymerization methods and processes are novel.

(33) B. Preparation

(34) The polymers of the present teachings can be prepared in solution by heating the monomers with alkali metal carbonate or a mixture of alkali metal carbonates. The alkali metal carbonates are typically sodium carbonate, potassium carbonate or a mixture of sodium carbonate, potassium carbonate and cesium carbonate.

(35) The alkali metal carbonates can be anhydrous, if hydrated salts are employed, where the polymerization temperature is less than about 250 C. Water can be removed, e.g. by heating under reduced pressure or dehydration via azeotropic distillation with organic solvent such as toluene or o-dichlorobenzene, prior to reaching the polymerization temperature.

(36) Where the polymerization temperature is greater than 250 C., such as 270 C., it is not necessary to dehydrate the carbonate first, as any water is driven off rapidly before it can adversely affect the polymerization reaction.

(37) The total amount of alkali metal carbonate used can be such that there is at least 1 atom of alkali metal for each phenol OH or phthalazinone NH group. An excess of alkali metal carbonate can be employed, and there may be 1 to 1.2 atoms of alkali metal per phenol OH or phthalazinone NH group.

(38) In various embodiments of the present teachings, the polymerization is carried out in an inert solvent such as diphenyl sulfone and benzophenone. In some embodiments, the polymerization is carried out at temperatures from about 200 C. to about 400 C. In some embodiments, the polymerization temperature is above about 260 C. The reactions are generally performed under atmospheric pressure; however, the reactions can also be performed at higher or lower pressures.

(39) For preparation of some polymers, it may be desirable to commence polymerization at one temperature, e.g. between about 180 C. and about 250 C., and then increase the temperature as polymerization ensues. This is particularly advantageous when fabricating polymers having only a low solubility in the solvent. Thus, it is desirable to increase the temperature progressively to maintain the polymer in solution as its molecular weight increases. In some embodiments, the process comprises an elevated temperature of about 180 C. to about 360 C. In other embodiments, the process comprises an elevated temperature of about 220 C. to about 340 C. In order to minimize degradation reactions in some embodiments, the maximum polymerization temperature can be below 360 C.

(40) The following examples are illustrative of the practice of the present teachings and are not intended in any way to limit their scope.

(41) C. Examples

Preparation of Poly(aryl ether ketone) from 4,4-Biphenol and Phthalazinone Monomer

(42) ##STR00010##

EXAMPLE 1

Copolymer with Molar Ratio of 4,4-Biphenol and Phthalazinone B/P=30/70

(43) To a 250 mL three-neck round-bottomed flask, equipped with a nitrogen inlet, thermocouple, mechanical stirrer, Dean-Stark trap and condenser, 21.82 grams (100.0 mmol) of dried 4,4-difluorobenzophenone, 16.76 grams (70.0 mmol) of dried phthalazinone monomer, 5.59 grams (30.0 mmol) of dried 4,4-biphenol and 14.65 grams (106.0 mmol) of anhydrous potassium carbonate were charged. Diphenyl sulfone (132.5 grams) and chlorobenzene (30.0 ml) were then added. The reaction medium was heated to 170 C., and chlorobenzene was distilled to remove water over one hour. The reaction mixture was then heated to 200 C. and maintained for two hrs. The reaction mixture was further heated to 300 C. and maintained for four hrs. The reaction was terminated, and the mixture was cast into sheet on a glass surface in a glass tray and cooled to room temperature. The cooled solid was then hammer milled to fine particles less than about 60 mesh.

(44) The fine particles were placed into a flask with 500 ml acetone, heated under reflux for one hour, and then filtered. This process was repeated five times to remove diphenylsulfone. The resulting powder material was then placed into a flask with 500 ml de-ionized water, heated under reflux for one hour, and then filtered. This process was repeated five times to remove inorganic salts.

(45) The resulting solid polymer was then dried at 120 C. under vacuum overnight. The white polymer has an inherent viscosity (IV) of about 0.78 dL/g (0.5 g/dL solution of the polymer in 98% sulfuric acid at 30 C.), a glass transition temperature of about 230 C., a melting temperature of about 316 C. and a melting endotherm of about 5.0 J/g. The polymer is insoluble in chloroform, dimethylformamide (DMF) and N-cyclohexylpyrrolidinone (CHP).

(46) The powdered polymer was compression molded at 375 C. for five minutes to give a tough opaque film. A sample of film immersed in chloroform at 25 C. for 24 hours showed a weight increase of 1.8%. The film remained resistant with no visible effects of attack by chloroform.

EXAMPLE 2

Copolymer with Molar Ratio of 4,4-Biphenol and Phthalazinone B/P=40/60

(47) A copolymer with a 40/60 molar ratio of 4,4-biphenol and phthalazinone monomer was prepared according to the procedure described in Example 1. The resulting polymer has an inherent viscosity (IV) of about 0.74 dL/g, a glass transition temperature of about 225 C., a melting temperature of about 336 C. and a melting endotherm of about 8.0 J/g. The polymer is insoluble in chloroform, dimethylformamide (DMF) and N-cyclohexylpyrrolidinone (CHP).

EXAMPLE 3

Copolymer with Molar Ratio of 4,4-Biphenol and Phthalazinone B/P=60/40

(48) A copolymer with a 60/40 molar ratio of 4,4-biphenol and phthalazinone monomer was prepared according to the procedure described in Example 1. The resulting polymer has an inherent viscosity (IV) of about 0.79 dL/g, a glass transition temperature of about 204 C., melting temperature of about 357 C. and a melting endotherm of about 16.0 J/g. The polymer is insoluble in chloroform, dimethylformamide (DMF) and N-cyclohexylpyrrolidinone (CHP).

EXAMPLE 4

Copolymer with Molar Ratio of 4,4-Biphenol and Phthalazinone B/P=65/35

(49) A copolymer with a 65/35 molar ratio of 4,4-biphenol and phthalazinone monomer was prepared according to the procedure described in Example 1. The resulting polymer has an inherent viscosity (IV) of about 1.48 dL/g, a glass transition temperature of about 205 C., a melting temperature of about 347 C. and a melting endotherm of about 14.0 J/g. The polymer is insoluble in chloroform, dimethylformamide (DMF) and N-cyclohexylpyrrolidinone (CHP).

EXAMPLE 5

Copolymer with Molar Ratio of 4,4-Biphenol and Phthalazinone B/P=70/30

(50) A copolymer with a 70/30 molar ratio of 4,4-biphenol and phthalazinone monomer was prepared according to the procedure described in Example 1. The resulting polymer has an inherent viscosity (IV) of about 0.75 dL/g, a glass transition temperature of about 200 C., a melting temperature of about 368 C. and a melting endotherm of about 25.0 J/g. The polymer is insoluble in chloroform, dimethylformamide (DMF) and N-cyclohexylpyrrolidinone (CHP).

EXAMPLE 6

Copolymer with Molar Ratio of 4,4-Biphenol and Phthalazinone B/P=75/25

(51) A copolymer with a 75/25 molar ratio of 4,4-biphenol and phthalazinone monomer was prepared according to the procedure described in Example 1. The resulting polymer has an inherent viscosity (IV) of about 0.73 dL/g, a glass transition temperature of about 190 C., a melting temperature of about 376 C. and a melting endotherm of about 26.0 J/g. The polymer is insoluble in chloroform, dimethylformamide (DMF) and N-cyclohexylpyrrolidinone (CHP).

EXAMPLE 7

Copolymer with Molar Ratio of 4,4-Biphenol and Phthalazinone B/P=80/20

(52) A copolymer with an 80/20 molar ratio of 4,4-biphenol and phthalazinone monomer was prepared according to the procedure described in Example 1. The resulting polymer has an inherent viscosity (IV) of about 0.95 dL/g, a glass transition temperature of about 185 C., a melting temperature of about 367 C. and a melting endotherm of about 24.0 J/g. The polymer is insoluble in chloroform, dimethylformamide (DMF) and N-cyclohexylpyrrolidinone (CHP).

COMPARATIVE EXAMPLE A

Amorphous Copolymer with Molar Ratio of 4,4-Biphenol and Phthalazinone B/P=20/80

(53) A copolymer with a 20/80 molar ratio of 4,4-biphenol and phthalazinone monomer was prepared according to the procedure described in Example 1. The resulting amorphous polymer has an inherent viscosity (IV) of about 1.02 dL/g (0.5 g/dL solution of polymer in chloroform at 25 C.) and a glass transition temperature of about 240 C. The polymer is soluble in chloroform, dimethylformamide (DMF) and N-cyclohexylpyrrolidinone (CHP) at room temperature.

COMPARATIVE EXAMPLE B

Amorphous Copolymer with Molar Ratio of 4,4-Biphenol and Phthalazinone B/P=25/75

(54) A copolymer with a 25/75 molar ratio of 4,4-biphenol and phthalazinone monomer was prepared according to the procedure described in Example 1. The resulting amorphous polymer has an inherent viscosity (IV) of about 0.78 dL/g (0.5 g/dL solution of the polymer in 98% sulfuric acid at 30 C.), and a glass transition temperature of about 232 C. The polymer is insoluble in chloroform, dimethylformamide (DMF) and N-cyclohexylpyrrolidinone (CHP) at room temperature.

COMPARATIVE EXAMPLE C

Low Molecular Weight Copolymer with Molar Ratio of 4,4-Biphenol and Phthalazinone B/P=70/30 Using N-cyclohexylpyrrolidinone (CHP) as Polymerization Solvent

(55) To a 100 mL three-neck round-bottomed flask, equipped with a nitrogen inlet, thermal couple, mechanical stirrer, Dean-Stark trap and condenser, 8.77 grams (40.0 mmol) of dried 4,4-difluorobenzophenone, 2.87 grams (12.0 mmol) of dried phthalazinone monomer, 5.24 grams (28.0 mmol) of dried 4,4-biphenol and 5.88 grams (42.4 mmol) of anhydrous potassium carbonate were charged. N-cyclohexylpyrrolidinone (CHP) (31.1 ml) and chlorobenzene (19.0 ml) were then added. The reaction medium was heated to 170 C., and chlorobenzene was distilled to remove water over one hour. The reaction mixture was then heated to 230 C. and maintained for four hours. At the end of the reaction, the mixture was poured into 200 ml of a mixture of methanol and water (ratio of 1:4). After filtration, the polymer powder was washed with methanol three times to remove any residual CHP. The resulting polymer powder was then placed into a 250 ml flask with 150 ml de-ionized water. The mixture was heated to reflux for three hours to remove any remaining potassium salt. After filtration, the white polymer powder was dried at 120 C. under vacuum over 24 hrs.

(56) The resulting polymer has an inherent viscosity (IV) of about 0.23 dL/g (0.5 g/dL solution of the polymer in 98% sulfuric acid at 30 C.), a glass transition temperature of about 185 C., a melting temperature of about 340 C. and a melting endotherm of about 37.0 J/g. The polymer is insoluble in chloroform, dimethylformamide (DMF) and N-cyclohexylpyrrolidinone (CHP). The powdered polymer was compression molded at 375 C. between two metal sheets for five minutes to obtain a brittle opaque film. The film was so brittle that it broke into small pieces when it was demolded from the metal sheet.

(57) The section headings used herein are for organizational purposes only and are not to be construed as limiting the subject matter described in any way.

(58) While the present teachings are described in conjunction with various embodiments, it is not intended that the present teachings be limited to such embodiments. On the contrary, the present teachings encompass various alternatives, modifications, and equivalents, as will be appreciated by those of skill in the art.