Classifications

• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L37/00—Compositions of homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by a heterocyclic ring containing oxygen; Compositions of derivatives of such polymers
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G73/00—Macromolecular compounds obtained by reactions forming a linkage containing nitrogen with or without oxygen or carbon in the main chain of the macromolecule, not provided for in groups C08G12/00 - C08G71/00
  • C08G73/06—Polycondensates having nitrogen-containing heterocyclic rings in the main chain of the macromolecule
  • C08G73/08—Polyhydrazides; Polytriazoles; Polyaminotriazoles; Polyoxadiazoles
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G73/00—Macromolecular compounds obtained by reactions forming a linkage containing nitrogen with or without oxygen or carbon in the main chain of the macromolecule, not provided for in groups C08G12/00 - C08G71/00
  • C08G73/06—Polycondensates having nitrogen-containing heterocyclic rings in the main chain of the macromolecule
  • C08G73/22—Polybenzoxazoles
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G81/00—Macromolecular compounds obtained by interreacting polymers in the absence of monomers, e.g. block polymers
• • H—ELECTRICITY
  • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
  • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
  • H05K1/00—Printed circuits
  • H05K1/02—Details
  • H05K1/03—Use of materials for the substrate
  • H05K1/0313—Organic insulating material
  • H05K1/032—Organic insulating material consisting of one material
  • H05K1/0346—Organic insulating material consisting of one material containing N

Definitions

• the present invention relates to the art of polybenzazole (PBZ) polymers and polymer compositions containing blocks of those polymers.
• PBZ polybenzazole
• PBZ polymers i.e., polybenzoxazole, polyben- zothiazole and polybenzimidazole, and their synthesis are described in great detail in the following patents which are incorporated by reference: Wolfe et al., Liquid Crystalline Polymer Compositions, Process and Products, U.S. Patent 4,703,103 (October 27, 1987); Wolfe et al., Liquid Crystalline Polymer Compositions, Process and Products, U.S. Patent 4,533,692 (August 6, 1985); Wolfe et al., Liquid Crystalline Poly(2,6-Benzo- thiazole) Compositions, Process and Products, U.S.
• Polybenzazole polymers and particularly "rigid rod” PBZ polymers, are noted for high tensile strength, high tensile modulus and high thermal stability.
• many polybenzazole polymers are difficult to fabricate into useful articles.
• Rigid and semi-rigid polybenzazoles do not have glass transition temperatures at any temperature at which they are stable. Therefore, the polymers are ordinarily spun from solution to form fibers, which serve as reinforcement within a thermosetting matrix, such as epoxy resins, to form composites.
• a thermosetting matrix such as epoxy resins
• Exemplary polymers include thermoplastic polyamides, polyimides, polyquinolines, polyquin- oxalines, poly(aromatic ether ketones) and poly(aromatic ether sulfones). However, those polymers do not have the high tensile strength and modulus which are characteristic of polybenzazole polymers.
• Hwang et al. "Phase Relationships of Rigid Rod Polymer/Flexible Coil Poly ⁇ mer/Solvent Ternary Systems," 23 Polymer Eng. & Sci. 789 (1983); and Hwang et al., "Composites on a Molecular Level: Phase Relationships, Processing and Properties," B22 J. Macromol. Sci.-Phys. 231 (1983).
• polybenzazole and particularly rigid and semi-rigid polybenzazole, are incompatible with many thermoplastic polymers.
• dopes containing polybenzazole and a thermoplastic polymer are coagulated, the polybenzazole agglomerates and/or phase separates.
• the resulting shaped articles either have poorer properties in all directions than the corresponding thermoplastic alone, or have superior properties in one direction and inferior properties in all other directions.
• Such compositions are useful for fibers, but not for molded articles.
• One aspect of the present invention is a block copolymer having (a) rigid rod or semi-rigid polybenzazole polymer blocks and (b) thermoplastic polymer blocks, characterized in that (1) each polybenzazole polymer block contains on average at least 5 mer units and less than 10 mer units; and (2) the block copolymer is thermoplastic and can be compression molded without substantial phase separation.
• a third aspect of the present invention is a briquette containing a granular composition of the present invention.
• a fourth aspect of the present invention is a process for forming a shaped article comprising the step of molding a solid granular composition in a mold at a temperature at which the granular composition is flowable and at a pressure sufficient to cause the granular composition to consolidate and conform to the shape of the mold, characterized in that (1) the granular composition contains a non-phase-separated block copolymer having (a) polybenzazole polymer blocks that contain on average at least 5 mer units per block and (b) thermoplastic polymer blocks of suitable size and proportions so that the block copolymer is flowable at a temperature below its decomposition temperature; and (2) the granular composition has an average particle diameter of no more than 1000 ⁇ .
• a fifth aspect of the present invention is a molded article made by the process of the present invention.
• Granular compositions and/or briquettes of the present invention can be used in the process of the present invention to fabricate the molded articles of the present invention.
• Such molded articles may be useful as structural elements, as circuit boards, or for any other purpose for which molded plastic articles are useful.
• Mer units are preferably linked by a bond from the divalent organic moiety (DM) to the 2-carbon of the first azole ring in an adjacent mer unit.
• Mer units suitable for AA/BB-PBZ polymers are preferably repre ⁇ sented by Formula 1 :
• Aliphatic divalent organic moieties preferably comprise no more than about 12 carbon atoms and more preferably no more than about 6.
• Aliphatic divalent organic 5 moieties are preferably saturated and more preferably alkyl.
• the first divalent organic moiety (A ⁇ ) is aromatic, and the second (A 2 ) is aliphatic.
• Each divalent organic moiety (T) must be stable in solvent acid, preferably up to at least about 50°C, more preferably up to at least about 100°C and most preferably up to at least about 200°C.
• Each divalent organic moiety (T) preferably comprises an aromatic group and more preferably consists essentially of an aromatic group or a plurality of aromatic groups linked by sulfur or oxygen atoms.
• Aromatic groups are most preferably meta- or para-phenylene groups.
• copolymers are described in Dahl et al., Aromatic Polyether Ketones Having Imide, Amide, Ester, Azo, Quinoxaline, Benzimidazole, Benzoxazole or Benzothiazole Groups and a Method of Preparation, International (PCT) application W086/02368 (published April 24, 1986), and in Harris et al., Copolymers Containing Polybenzoxazole, Polybenzothiazole and Polybenzimidazole Moieties, International Application No. PCT/US89/04464 (filed October 6, 1989), International Publication No. WO 90/03995 (published April 19, 1990).
• copolymers are preferably represented by the Formula:
• the thermoplastic blocks may be synthesized in a manner that is ordinary for the particular type of polymer selected.
• the thermoplastic polymer blocks may be linked to the rigid or semirigid polybenzaozle block either (i) by reaction of an o-amino-basic moiety and an electron-deficient carbon group to form of an azole ring; or (ii) by Friedel-Crafts reaction of an aromatic group and an acid group to form a carbonyl or sulfonyl group bonded to the aromatic group. Both reactions may be carried out in a dehydrating solvent acid, such as polyphosphoric acid or methanesulfonic acid/P2 ⁇ 5.
• the end groups of the blocks should be selected so that they can react in such an environment.
• the proportions of polybenzazole block to thermoplastic block are chosen so that the entire block copolymer is thermoplastic.
• the block copolymer may contain between -1 percent and 99 percent thermoplastic block by weight. It preferably contains at least 10 percent thermoplastic block by weight, more preferably contains at least 30 percent thermoplastic block by weight, and most preferably contains at least 70 percent thermoplastic block by weight. It preferably contains at least 3 percent rigid or semirigid polybenzazole block by weight and more preferably contains at least 5 percent rigid or semirigid polybenzazole block by weight.
• the block copolymer should become flowable at a temperature at which it does not substantially decompose.
• copolymer as a whole also affects the flowability of the block copolymer.
• the average molecular weight should be kept low enough that the granular composition consolidates during molding to provide a molded article pt - having physical properties superior to molded articles made from the thermoplastic homopolymer alone.
• Molecular weight may be regulated either by adjusting the stoichiometry of the reaction or by use of a chain terminator. Many different monofunctional reagents may be used.
• compositions and molded articles of the present invention may consist essentially of a block copolymer as previously described.
• compositions and molded articles of the present invention may contain thermoplastic polymers or polybenzazole polymers which are not part of a block copolymer, or both.
• the polymers are preferably selected such that the physical properties of the molded composition are superior to physical properties of the thermoplastic polymer alone, in at least two dimensions.
• the polymers are more preferably selected such that the composition does not experience substantial phase separation during coagulation or molding. If the composition contains a thermoplastic polymer, it is preferably a homopolymer or copolymer having a structure similar to the thermo ⁇ plastic blocks of the block copolymer.
• the concentra ⁇ tion of polybenzazole polymer in the composition should be low enough that the composition is moldable.
• the proportions of rigid or semirigid polybenzazole outside of block copolymers are preferably minimized.
• the composition most preferably contains no rigid or semirigid polybenzazole outside of the block copolymer.
• the block copolymers and polymer compositions containing them are ordinarily formed in a solvent acid solution or dope, from which they may be coagulated by contacting the dope with a non-solvent diluent such as water.
• the dope must ordinarily be in an optically isotropic (non-liquid crystalline) state when coagulated in order to form a coagulated product which is at least planar isotropic (isotropic in two dimensions) and is more preferably isotropic in three dimensions.
• the coagulated product is most preferably not optically phase separated. Liquid crystalline dopes tend to form phase separated and anisotropic coagulated products.
• Optical isotropy and anisotropy of the dope can be determined by a number of tests familiar to persons of ordinary skill in the art, such as those described in - Hwang et al., "Composites on a Molecular Level: Phase Relationships, Processing, and Properties," B22(2) J. Macromol. Sci.-Phys. 231, 234-35 (1983). A simple method is to see if the solution exhibits birefringence when viewed under a microscope under cross-polar 5 conditions. Within even optically isotropic solutions, some association of rigid rod blocks is likely on a molecular scale. However, in polymers precipitated from the optically isotropic phase, the level of anisotropy and phase-separation is preferably small enough to 0 provide a block copolymer or polymer composition which is essentially a molecular composite.
• the preferred concentration of polymer in optically isotropic dopes of the present invention varies depending upon the portion of the polymer which is rigid rod PBZ. If the polymer in the dope contains only 5 weight percent rigid rod PBZ block or less, then the concentration of polymer in the dope may be as high as the solvent acid can dissolve, such as 50 weight percent or less. If the polymer contains 30 weight percent rigid rod PBZ block, then the dope preferably comprises no more than 15 weight percent polymer. If the polymer contains 50 weight percent rigid rod PBZ block, then the dope preferably comprises no more than 10 weight percent polymer. If the polymer comprises 70 weight percent rigid rod PBZ block, then the dope preferably comprises no more than 6 weight percent polymer and more preferably no more than 4 weight percent polymer.
• the solvent acid in the dope has the definition and preferred embodiment previously given for solvent acids. It is most conveniently the solvent acid in which the block copolymer was synthesized. However, the block copolymer may be synthesized in a first solvent acid such as polyphosphoric acid, coagulated, and redissolved in a second solvent acid such as methanesulfonic acid.
• a first solvent acid such as polyphosphoric acid
• coagulated coagulated
• a second solvent acid such as methanesulfonic acid.
• the dope may also contain other additives that precipitate with the polymers, such as stabilizers or coloring agents. Preferably, such additives are minimized.
• the polymer is recovered from the dope by contacting the dope with a non-solvent which causes the block copolymer to coagulate.
• the non-solvent is preferably aqueous.
• the non-solvent may be basic or slightly acidic, but is preferably neutral at the commencement of its use. Of course, the non-solvent bath may become progressively more acidic as it coagulates more dope unless the non-solvent in the bath has a reasonably steady flow of non-solvent to and from the bath or a pH adjusting material is added.
• the dope may be frozen.
• the dope is preferably frozen at a temperature less than 0°C, more preferably' at most -78°C, more highly preferably at most -150°C and most preferably at most -190°C.
• a convenient temperature is liquid nitrogen temperature.
• the frozen dope is more easily ground than is the coagulated polymer and may be ground on ordinary grinding equipment suitable for grinding the frozen solvent acid, such as a ball mill or attrition mill.
• the ground dope is then placed in a relatively warmer non-solvent bath, which causes the dope to melt and the polymer to coagulate.
• the bath must be at a temperature above the freezing point of the dope.
• the dope may be sprayed in a fine mist into a coagulation bath.
• the coagulation bath is preferably agitated or otherwise in motion.
• the powders resulting from either method are preferably filtered, washed, and dried in order to recover the granular composition. Spray extraction of polymers and equipment for carrying it out are described in the following U.S. Patents: 3,953,401; 4,100,236; 4,206,161 and 4,469,818.
• the resulting granular product should have an average particle size small enough to be molded into a solid article.
• the average particle diameter is preferably no more than 500 ⁇ , more preferably no more than 100 ⁇ , more highly preferably no more than 50 ⁇ , and most preferably, no more than 10 ⁇ .
• the particles are preferably homogeneous, having approximately the same mixtures and proportions of polymers as were found in the dope.
• Polymer within the particles is preferably isotropic in at least two dimensions (planar isotropic), and is more preferably isotropic in three dimensions.
• Granular compositions of the present invention may be molded as they are, but they are conveniently pressed to form a briquette for easier handling.
• the briquette is formed by subjecting the powder to a pressure high enough to press it together so that it will not fall apart again when pressure is released.
• the pressure is preferably at least 50 psi, more preferably at least 500 psi, and most preferably at least 2000 psi.
• the preferred size of the briquette is limited primarily by practical considerations. It must be of an appropriate size for the mold in which it will be used. If it is too large there may be difficulty in pressing a single briquette from the powder.
• the granular composition of the present invention may be molded by heating under pressure in a mold.
• the mold may be as simple as two heated platens for making a flat
• the granular composition may be molded in the mold alone, or fibers may be intermixed with the granular composition such that the resulting molded product is a fiber reinforced composite. Examples of suitable fibers
• the granular composition may also be molded in a mixture with granular additives, such as stabilizers, fillers, pc - coloring agents, rubber modifiers or other additives.
• the temperature and pressure of molding are chosen so that the individual particles of the granular composition fuse to form a single article.
• Optimum 30 temperature, pressure and time of molding necessarily depend upon the flowability of the polymers in the granular composition.
• Copolymers that contain longer rigid or semi-rigid segments contain higher concentrations of rigid and semi-rigid segments and have higher average molecular weights ordinarily require higher molding temperatures and pressures and longer molding times than similar copolymers that contain shorter rigid or semi-rigid segments, contain lower concentrations of rigid and semi-rigid segments and/or have lower average molecular weights.
• the temperature should be at least the glass transition temperature of the granular composition. It is preferably at least 5 to 10°C above the glass transition temperature of the granular composition. It should also be below the temperature at which substantial decomposition occurs in the granular composition.
• the preferred temperatures are highly dependent upon the chemical and physical make-up of the granular composition.
• the temperature is preferably at least 250°C, more preferably at least 325°C and most preferably at least 350°C.
• the temperature is preferably at least 100°C and more preferably at least 150°C.
• the molding temperature is preferably at least 200°C, more preferably at least 250°C, and most preferably at least 350°C.
• the molding temperature is preferably at least 200°C, more preferably at least 230°C, and most preferably at least 270°C.
• the molding temperature is preferably at most 500°C, more preferably at most 475°C, and most preferably at most 450°C.
• the molding temperature is prefer ⁇ ably at most 400°C, more preferably at most 350°C, and most preferably at most 300°C. Optimum temperatures for each granular composition may be determined without undue experimentation by persons of ordinary skill in the art.
• the pressure may be any pressure at which individual particles in the granular composition will fuse and consolidate to form a single article. Preferred pressure is also dependent upon the physical and chemical make-up of the granular composition and upon the temperature at which molding occurs.
• the pressure is preferably as low as is necessary to obtain sufficient consolidation of the powder to make a molded product.
• Fo block copolymers containing at least 75 percent of thermoplastic polymer block the pressure is preferably no more than 50,000 psi, more preferably no more than 10,000 psi and most preferably no more than 5000 psi. To obtain good consolidation the pressure is ordinarily at least 50 psi, more typically at least 500 psi and most often at least 1000 psi. Optimum pressure may be determined by persons of ordinary skill in the art without undue experimentation.
• the molded article may optionally be annealed after it is molded.
• the annealing preferably takes place at a temperature above the glass transition temperature of the polymer in the molded article, but below its melting point.
• Annealing more preferably takes place at a temperature close to the melting point of the polymer.
• Annealing may take place at sub- atmospheric or supratmospheric pressures, but is conveniently at ambient pressure.
• the atmosphere for annealing is preferably air or nitrogen, but may be any other atmosphere in which the polymer is essentially stable under annealing conditions.
• Annealing typically causes an increase in the tensile strength of the molded article, but may also cause a slight decrease in the tensile modulus of the molded article.
• the product of the molding process is a molded article containing the block copolymers previously described, wherein the granules of the granular composition are fused together.
• the fusion of individual particles may be less than perfect and complete, but the molded article is preferably almost void free (less than 1 percent void space).
• the polymer in the molded article is preferably at least optically planar isotropic and more preferably optically isotropic in all dimensions.
• the molded article may exhibit some crystalline zones.
• the molded article preferably has physical properties which are superior to the physical properties of similar molded articles that contain only polymers similar to the thermoplastic block of the block copolymer.
• the molded article may have higher tensile strength, tensile modulus, flexural modulus, flexural strength, dimensional stability and/or solvent resistance.
• the improvement in properties is preferably exhibited in at least two perpendicular dimensions and more preferably in all directions. In other words, the improvement is at least biaxial, rather than uniaxial.
• the improvement in properties need not be uniform in all directions, but it preferably is uniform.
• Example 1 Granular compositions containing (a) a block copolymer of 50 percent cis-polybenzoxazole and 50 percent amorphous polyamide, and (b) amorphous polyamide, and molded articles made from them
• Dopes are synthesized containing (a) a block copolymer of rigid rod cis-polybenzoxazole and amorphous polyamide; and (b) an amorphous polyamide polymer.
• the solvent acid of the dope is a mixture of methanesulfonic acid, polyphosphoric acid and phosphorus pentoxide.
• the cis-polybenzoxazole blocks in the block copolymer have the calculated number average of mer units shown in Table 1 and the inherent viscosity (before incorporation into the block copolymer) shown in Table 1 , as measured in methanesulfonic acid at 25°C and 0.05 g/dL concentration.
• the amorphous polyamide blocks in the block copolymer are the product of reacting hexa- methylene diamine with a mixture containing 30 percent terephthaloyl chloride and 70 percent isophthaloyl chloride and appropriate amounts of 4-phenoxyphenoxy- benzoyl chloride.
• the block copolymer is synthesized by (1) end- -capping the polybenzoxazole block with decoupled carboxylic acid halide; (2) contacting it with polyamide that is end-capped with decoupled aromatic groups; and (3) reacting essentially equivalent moles and weights of the end-capped polymers in dehydrating solvent acid under conditions such that aromatic electrophilic substitution occurs.
• the process is described in detail in Harris et al., Copolymers Containing Polybenzoxazole, Polybenzothiazole and Polybenzimidazole Moieties, International Application No. PCT/US89/04464 (filed
• the resulting block copolymer contains about 50 percent by weight cis-polybenzoxazole and about 50 percent by weight amorphous polyamide, and has the inherent viscosity shown in Table 1, as measured in methanesulfonic acid at 25°C and 0.05 g/dL - concentration.
• amorphous polyamide sold under the trademark of Selar-PA IU by E.I. DuPont de Nemours & Co. is added to each dope until the total weight proportions of poly- 5 benzoxazole to polyamide in each dope (counting both polyamide in the block copolymer and polyamide not in the block copolymer) is about 15 percent polybenzoxazole to 85 percent amorphous polyamide.
• the resulting dopes are optically isotropic (not liquid crystalline).
• the 0 total concentration of amorphous polyamide and block copolymer in the dope is 4 weight percent.
• Each dope is frozen at a temperature between c -190°C and -200°C, and ground to a particle size distribution between 10 ⁇ and 2000 ⁇ .
• the ground frozen dopes are added to an agitated water bath at about room temperature.
• the resulting precipitated granular compositions are filtered, washed and dried. They have 0 a particle size distribution between 1 ⁇ and 250 ⁇ .
• each powder is pressed under 20,000 psi pressure at room temperature for about 10 seconds to form a briquette.
• Each briquette is molded at the temperature and pressure shown in Table 1 for the time shown in Table 1 to form a disk having a thickness of about ⁇ 6-inch (0.16 cm) and a diameter of about 2j-inches (6.4 cm).
• Each disk is tested for flexural strength and modulus by the test described in ASTM D-790. It has the strength, modulus and strain shown in Table 1.
• Example 2 Granular compositions containing a block copolymer of 10 percent cis-polybenzoxazole and 90 percent poly(aromatic ether ketone), and molded articles made from them
• Dopes are formed containing 10 weight percent cis-polybenzoxazole and 90 weight percent poly(aromatic ether ketone).
• the solvent acid of the dope is a mixture of methanesulfonic acid, polyphosphoric acid and phosphorus pentoxide.
• the cis-polybenzoxazole blocks in the block copolymer have the calculated average number of mer units shown in Table 2 and the inherent viscosity (before incorporation into the block copolymer) shown in Table 2, as measured in methanesulfonic acid at 25°C and 0.05 g/dL concentration.
• the poly(aromatic ether ketone) blocks in the block copolymer are the product of reacting oxy-bis-(4-benzoyl chloride) with 1 ,4-diphenoxybenzene.
• the block copolymer is synthesized by (1) end- -capping the polybenzoxazole block with decoupled carboxylic acid halide; (2) reacting the polybenzoxazole block terminated by a decoupled acid group with oxy-bis-(4-benzoyl chloride) and 1,4-diphenoxybenzene and benzoic acid (a terminator) under conditions such that aromatic electrophilic substitution occurs.
• the process is described in detail in Harris et al., Copolymers Containing Polybenzoxazole, Polybenzothiazole and Polybenzimidazole Moieties, International Application No. PCT/US89/04464 (filed October 6, 1989), International Publication No.
• the resulting block copolymer composition contains about 10 percent by weight cis-polybenzoxazole and about 90 percent by weight poly(aromatic ketone), and has the inherent viscosity shown in Table 2, as measured in methane ⁇ sulfonic acid at 25°C and 0.05 g/dL concentration. Its concentration in the dope is about 8 weight percent.
• the resulting dopes are optically isotropic (not liquid crystalline) .
• Each dope is frozen at a temperature between -190°C and -200°C, and ground to a particle size distribution between about 10 ⁇ and 2000 ⁇ .
• the ground frozen dopes are added to an agitated water bath at about room temperature.
• the resulting precipitated granular compositions are filtered, washed and dried.
• Some granular compositions are also extracted with acetone or acetyl acetone.
• the granular compositions have a particle size distribution between about 1 ⁇ and 250 ⁇ .
• Each briquette is molded at the temperature and pressure shown in Table 2 for the time shown in Table 2 to form a disk having a thickness of about 1/-
• Example 3 Granular compositions containing a block copolymer of cis-polybenzoxazole and a thermoplastic polybenzoxazole/poly(aromatic ether ketone) copolymer, and molded articles made from them
• Dopes are formed containing cis-polybenzoxazole and thermoplastic polybenzoxazole/poly(aromatic ether ketone) copolymer in the proportions shown in Table 3 *
• the solvent acid of the dope is a mixture of methanesulfonic acid, polyphosphoric acid and phosphorus pentoxide.
• the cis-polybenzoxazole blocks in the block copolymer have the calculated average number of mer units shown in Table 3 and the inherent viscosity (before incorporation into the block copolymer) shown in Table 3, as measured in methanesulfonic acid at 25°C and 0.05 g/dL concentration.
• the polybenzoxazole/(aromatic ether ketone) blocks in the block copolymer are the product of reacting 4,6-diaminoresorcinol, oxy-bis- -(4-benzoyl chloride) and 1,4-bis-(phenoxy)benzene in a molar ratio of about 1:2:1.
• the block copolymer is synthesized by ( 1) reacting the polybenzoxazole oligomer and 4,6-diamino- resorcinol with 2 moles of oxy-bis-(4-benzoyl chloride) per mole of oligomer and 4,6-diaminoresorcinol combined; (2) reacting the product of step 1 with about 1 mole of 1 ,4-bis(phenoxy)benzene per mole of oligomer and 4,6- -diaminoresorcinol combined and with benzoic acid (a terminator) under conditions such that aromatic electrophilic substitution occurs.
• the resulting block copolymer composition has the calculated average structure illustrated in Formula
• a is a number of mer units in the rigid rod polybenzazole blocks corresponding on average 30 to the figures provided in Table 3; b is a number of mer units in the thermo ⁇ plastic block chosen such that on average the weight ratio of rigid rod polymer to thermoplastic polymer corresponds to the ratio given in Table 3; c is an number of repeating units such that the block copolymer has on average a molecular weight corresponding to the inherent viscosity in Table 3; and d is number of repeating units within each mer unit of the thermoplastic block which averages about 1.
• Each dope is frozen at a temperature between -190°C and -200°C, and ground to a particle size distri ⁇ bution between about 10 ⁇ and 2000 ⁇ .
• the ground frozen dopes are added to an agitated water bath at about room temperature.
• the resulting precipitated granular compositions are filtered, washed and dried.
• Some granular compositions are further extracted with acetone or acetyl acetone. They have a particle size distri- bution between about 10 ⁇ and 2000 ⁇ .
• Each briquette is molded at the temperature and pressure shown in Table 3 for the time shown in Table 3 to form a disk having a thickness of about 1/i -inch (0.16 cm) and a diameter of about 2£-inches (6.4 cm).
• Each disk is tested for flexural strength and modulus by the test described in ASTM D-790. It has the strength, modulus and strain shown in Table 3.
• Example 4 Granular compositions containing a block copolymer of cis-polybenzoxazole and a thermoplastic polybenzoxazole/poly(aromatic ether ketone) copolymer, and molded articles made from them
• Example 3 is repeated, except that the ratios of 4,6-diaminoresorcinol, oxy-bis-(4-benzoyl chloride) and 1 ,4-bis-(phenoxy)benzene are adjusted so that the resulting block copolymer is represented by Formula 3, wherein d averages 0.33 (the poly(aromatic ether ketone) content of the thermoplastic block is increased).
• d averages 0.33 the poly(aromatic ether ketone) content of the thermoplastic block is increased.
• a functionally terminated rigid rod cis- -polybenzoxazole block is prepared which has an inherent viscosity of 5.77 dL/g, is predominantly terminated at each end by an o-amino-hydroxy moiety, and consists essentially (except for the end groups) of mer units represented by the Formula:
• the functionally terminated block is reacted in a mixture of methanesulfonic acid and polyphosphoric acid with 4,6-diaminoresorcinol dihydrochloride and sebacic acid.
• concentration of solids in the reaction mixture is sufficient to provide a dope containing about 2 weight percent solids, and the ratio of monomers to functionally terminated block is suitable to provide a block copolymer containing about 5 weight percent rigid rod block and about 95 weight percent aliphatic polybenzoxazole block. No terminator is added.
• the resulting dope is frozen at liquid nitrogen temperature and ground for two hours using 7.4 lbs. of ceramic balls.
• the frozen granular composition is coagulated in a blender in phosphate buffered slurry with crushed ice while periodically adding aqueous sodium hydroxide as needed to maintain the pH of the system at about 7 to 8.
• the precipitated granular composition is filtered, washed twice in deionized water and once in acetone for several hours each washing, and dried under air and in a vacuum oven to constant weight,
• a quantity of powder as shown in Table 1 is pressed under about 20,000 pressure at room temperature for about 10 seconds to form a briquette.
• Each briquette is molded at the temperature and pressure shown in Table 1 for the time shown in Table 1 to form a disk having a thickness of about 1/-
• Each disk is tested for flexural strength and modulus by the test described in ASTM D-790. It has the strength, modulus and strain shown in Table 5.
• Example 6- Granular compositions containing a block copolymer of 5 percent rigid rod cis- -polybenzoxazole and 95 percent aliphatic polybenzoxazole, and molded articles made from them
• a functionally terminated rigid rod cis- polybenzoxazole block is prepared which has an inherent viscosity of 5.1 dL/g, is predominantly terminated at each end by an o-amino-hydroxy moiety, and consists essentially (except for the end groups) of mer units represented by the Formula:
• the functionally terminated block is reacted in polyphosphoric acid with 4,6-diaminoresorcinol dihydrochloride and sebacic acid.
• the ratio of monomers to functionally terminated block is suitable to provide a block copolymer containing about 5 weight percent rigid rod block and about 95 weight percent aliphatic polybenzoxazole block.
• 2-aminophenol is added as a terminator in a quantity equal to 5 weight percent of the diaminoresorcinol that is reacted with sebacic acid.
• the resulting polymer has an intrinsic 5 viscosity of 7.93 dL/g.
• the resulting dope is coagulated in a blender in phosphate buffered aqueous coagulation bath while periodically adding aqueous sodium hydroxide as needed to maintain the pH of the system at about 7 to 8.
• the 0 precipitated granular composition is filtered, washed several times in deionized water, filtered, and dried in air and in a vacuum oven to constant weight.
• a 7.3 g quantity of powder is pressed under about 20,000 pressure at room temperature for about 10 seconds to form a briquette.
• the briquette is molded at 225°C and 20,000 psi pressure for 3 minutes to form a disk having a thickness of about 1/i ⁇ inch (0.16 cm) and a diameter of about 2£-inches (6.4 cm).
• Each disk is tested for flexural strength and modulus by the test described in ASTM D-790. It has a flexural strength of 4,705 psi and a flexural modulus of 371,000 psi.

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• Macromolecular Compounds Obtained By Forming Nitrogen-Containing Linkages In General (AREA)

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• 1991
  • 1991-06-25 WO PCT/US1991/004530 patent/WO1992000353A1/fr not_active Application Discontinuation
  • 1991-06-25 EP EP19910914502 patent/EP0540657A4/en not_active Withdrawn
  • 1991-06-25 CA CA002086555A patent/CA2086555A1/fr not_active Abandoned
  • 1991-06-25 JP JP91514049A patent/JPH05508683A/ja active Pending
  • 1991-06-25 KR KR1019920703425A patent/KR930701539A/ko not_active Application Discontinuation

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