KR940007690B1 - Spinnable dopes, their preparation and articles therefrom - Google Patents

Abstract

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Description

Radiant stock solution, preparation method thereof and product made therefrom

This application is a sequential application of the United States Patent Application Nos. 919,028 (October 15, 1986) and 033,259 (April 2, 1987) of the inventors.

Poly-p-phenylenebenzobisthiazoles, poly-p-phenylenebenzobisoxazoles and poly-2,5-benzoxazoles are intractable polymers that are insoluble but mean soluble. Mixtures of these polymers have been made of thermoplastic polymers to provide melt-processability. Mixtures of these polymers with other difficult polymers have been prepared for various purposes. The process for preparing such mixtures has the drawback that the available techniques for preparing processing polymer mixed solutions require the separation of difficult-to-process polymers from their polymerization solvent, polyphosphoric acid, before preparing the polymer mixed solutions. The present invention overcomes this deficiency.

The present invention provides an agent selected from poly-p-phenylenebenzobisthiazole, poly-p-phenylene benzobisoxazole or poly-2,5-benzoxazole in a solvent mixture of polyphosphoric acid and methanesulfonic acid or chlorosulfonic acid. Provided is a spinnable quaternary dope comprising a polymer mixture of 5 to 70 weight percent of one polymer and 30 to 95 weight percent of a second polymer selected from a thermoplastic polymer or another difficult polymer. The concentration of the polymer mixture in the urea mixture is at least 1% by weight. Also included are methods of making such spinable quaternary stock solutions and fibers made therefrom.

Poly-p-phenylenebenzobisthiazole (PBT), poly-p-phenylenebenzobisoxazole (PBO) and poly-2,5-benzoxazol (AB-PBO) are prepared in polyphosphoric acid (PPA). [US Pat. No. 4,533,693]. Since the polymers are very difficult to process and therefore not easily melt processed, attempts have been made to mix them with thermoplastic polyamides. Typically, the following preparation method involves separating PBT, PBO or AB-PBO from the polymerization solvent and then re-dissolving it in low concentration methanesulfonic acid. Then, thermoplastic polyamide is added to the solution so that the total polymer concentration is 5% by weight or less. The solution is then processed into fibers or films.

The present invention provides a novel spinable quaternary stock solution and its manufacturing technique, that is, a manufacturing technique that is difficult to infer from the prior art and superior to the prior art. The manufacturing techniques of the present invention in particular comprise preparing a thermoplastic polymer solution in methanesulfonic acid (MSA) or chlorosulfonic acid or equivalent strong acid. Any of a variety of thermoplastic polymers can be used as a component that provides melt processability. Thermoplastic polyamides are preferred. The concentration of thermoplastic polymer in the solution may range from about 0.5 to 20%, preferably 1 to 15% by weight. Instead of thermoplastic polymers, it is possible to use difficult polymers such as poly-2,5 (6) -benzimidazole (ABPBI).

A solution of PBT, PBO or AB-PBO in a polyphosphoric acid polymerization solvent is added to a solution of a thermoplastic polymer or a hard polymer, and then the mixed solution is shear mixed. Preferably, the intrinsic viscosity of PBT, PBO or AB-PBO measured in MSA should be at least 15 dl / g. The PBT, PBO or AB-PBO concentration in the polyphosphoric acid should be at least 0.5% by weight, preferably 1 to 20% by weight. The mixed polymer concentration of the resulting quaternary solution should be at least 1% by weight and the MSA / PPA solvent ratio should be 95/5 to 5/95 by weight. The presence of PPA increases the spinning solution viscosity, which improves radioactivity. Indeed, shearing of PBT, PBO or AB-PBO chunks in polyphosphoric acid, preferably added to a solution of the thermoplastic polymer without heating externally, prevents degradation of the less stable thermoplastic polymer. Atlantic Mixers are quite useful for the purposes of the present invention, and the shearing action is performed by a wall wiping mechanism. The proportion of the solution is chosen such that the ratio of PBT, PBO or AB-PBO to the thermoplastic or difficult to process polymer is obtained at the desired ratio in the stock solution. While varying the ratio of the two solutions yields different polymer ratios, it is preferred that the final concentration of the total polymer in the quaternary stock is constant since the concentrations of the two solutions are nearly the same. The ratio of PPA to MSA or chlorosulfonic acid is preferably 60:40 to 30:70 by weight. For maximum benefit, PBT, PBO or AB-PBO should be comprised of 5 to 70 weight percent polymer mixture. The second polymer should be 30 to 95% by weight. Preferably, the polymer should be in a weight ratio of 60:40 to 40:60.

The present invention provides operational advantages since there is no need to separate PBT, PBO or AB-PBO from the polymerization solvent. In addition, mixing the polymer as a solution solves the problems faced by the prior art. For example, thermoplastic polyamides are relatively insoluble in polyphosphoric acid at room temperature. It has been found that the thermoplastic polyamide decomposes extremely when heated to enhance the solvent in the polyphosphoric acid. Surprisingly, the solution can be mixed by shear mixing without the use of high temperatures that can degrade the thermoplastic polyamide. A further advantage is that the fluidity of the quaternary solution resulting from the mixed solution is such that air-gap spinning is possible. Fibers spun from these quaternary solutions have been found to have significantly greater tensile properties than fibers spun from tertiary solutions of the same polymer mixture. Novel microstructures were observed on scanning electron micrographs of cross sections transverse to the fiber length. The composite fiber according to the present invention containing the thermoplastic polymer as the second polymer may be wound into a molded article and then compression molded by heating to produce films, rods and other composite articles.

The following examples illustrate the invention but are not intended to limit the invention. Intrinsic viscosity is measured in MSA:

Example 1

In a glass jar 15 parts by weight of thermoplastic polyamide is added to 85 parts by weight of MSA and stirred at room temperature using a magnetic stirrer simply coated with polytetrafluoroethylene. The thermoplastic polyamides used are amorphous copolymers of (48tt) bis (p-aminocyclohexyl) methane, isophthalic acid and dodecanedioic acid on a 100/60/40 mole percent basis. This solution is a brown viscous liquid. 60.5 g of this solution is poured into an Atlantic mixer (Model No. 2CV, volume: 150 kPa). Subsequently, 61.8 g of 14.5% by weight PBT stock solution (intrinsic viscosity: 19.6 kV / g) in PPA is added to the mixture without heating externally while the mixer is running at low speed. PBT / PPA stock solution is ground and "dissolved" in polyamide-MSA solution. Continue mixing until the next day, resulting in a uniform mixture. The resulting quaternary solution or stock solution shows shear gloss. If it is stirred, it is degassed under vacuum overnight. The stock solution is transferred to a spinning cell and the solvent is extracted by spinning into an ice water bath at 54 ° C. through a 0.25 inch air gap. The stock solution is spun at 7.5 m / min from a 10-hole spinneret (hole diameter: 0.004 inch). The discharge amount is 0.02 ml / min per hole. To completely remove the acid solvent, the bobbins of the yarn are immersed in water overnight and then air dried. The filament tensile properties (denier, strength, elongation, modulus) (D / T / E / M) of the spun composite yarn (PBT / polyamide, weight 50/50 or volume 42/58) are 66 denier, 4.3 gpd, 1.4 %, 344 gpd, and the orientation angle is 15 degrees. Thermal stability is measured by passing the yarn through a hot horizontal tube with one end tied and the other end loaded with a 10 g load. The temperature is raised to 716 ° C. over 3 hours 30 minutes, which is the time at which the yarn breaks.

Example 2

15 g of a copolymer of hexamethylene diamine, (20tt) bis (p-aminocyclohexyl) methane, isophthalic acid and terephthalic acid based on 96/4/70/30 mol%, an amorphous thermoplastic polyamide, is dissolved in 85 g of MSA at room temperature. . 72.3 g of this solution were mixed with 73.2 g of the same PBT / PPA stock solution as used in Example 1 to obtain PBT / polyamide having a weight ratio of 50/50 and MSA / PPA having a solvent ratio of 50/50. Mix without heating externally. After a few hours, a homogeneous quaternary spinning stock is obtained. It is shear shiny and metallic pale green. Continue mixing until the next day and apply vacuum to degas the stock solution. After standing for one week, phase separation occurs. The stock solution is mixed for 2.5 hours and then transferred to the spinning cell. It is spun into ice water at 60 ° C with 7.5 m / min between 0.75 inch air gaps with a spin-elongation coefficient of 4.7 from 10 spinnerets with 0.005 inch diameter. The yarns are immersed in water for several days, all MSA remaining in acetone is removed and then air dried. Tensile properties (T / E / M) of 50/50 PBT / polyamide composite fibers are 3.7 gpd, 0.6%, 390 gpd. The yarn carrying out the thermal stability test in the same manner as in Example 1 withstands up to 723 ° C. In the separation experiment, a higher ratio of 62.38 PBT: polyamide is used. The T / E / M properties of the spun composite fibers are 5.7 gpd / 0.82% / 691 gpd.

Example 3

30 g of the polyamide of Example 1 and 170 g of MSA were used to prepare a solution. 94.2 g of this solution was mixed with 141.3 g of the same PBT / PPA stock solution used in the examples above to obtain a spinning stock solution having a PBT / polyamide ratio of 60/40 by weight or 53/47 by volume and 40/90 by MSA / PPA. Manufacture. The homogeneous quaternary spinning stock is heated to 60 ° C. to reduce the viscosity for transfer to the spinning cell. Spinning at 75 ° C. at 7.5 m / min through a 0.375 inch air gap, using 10 spinnerets with 0.005 inch diameter holes. The radioactivity is excellent. After overnight immersion in water, the next night the bobbins of Sasa are immersed in acetone to extract all remaining MSA. The T / E / M properties of the dried composite fibers were 5.3 gpd / 1.0% / 342 gpd.

Example 4

54.3 g of the polyamide / MSA solution of Example 3 and 81.4 g of the same PBT / PPA stock solution as used in the examples above were used for the PBT and the polyamide of Example 1 at a polymer weight ratio of 59.2 / 40.8 (volume ratio 51/49). Prepare spinning stock solution. The quaternary spinning stock produced with an MSA / PPA ratio of 40/60 is mixed without external heating. The next day, the temperature is raised to 75 ° C. and maintained at 75 ° C. for 1.5 hours to reduce the viscosity and then transferred to the spinning cell. Using a spinneret with ten holes of 0.005 inch diameter, spin at 75 ° C. at 7.5 m / min between 0.5 inch air gaps. The T / E / M properties of the spun composite fiber are 7.3 gpd / 1.5% / 586 gpd.

Example 5

Using 65.2 g of 15% polyamide in MSA and 136.2 g of 14.1% cis-PBO (extreme viscosity: 16.6 L / g) in PPA, cis-PBO and the polyamide of Example 1 were weighted at 66/34 (volume ratio 59/41). To prepare a quaternary spinning solution containing. The mixture with an MSA / PPA ratio of 32/68 is mixed overnight under house vacuum (vacuum: 24 inches) without external heating. The next day, the resulting quaternary stock solution is heated to 60 ° C. to improve fluidity to fill the spinning cell. Stock solution is shear anisotropic. Using a spinneret with 10 holes (hole diameter: 0.005 inch), spin at 60 ° C at 7.5 m / min through an air gap of 0.75 inch. The T / E / M tensile property of the composite fiber is 8.4 gpd / 2.2% / 324 gpd. The orientation angle of the fiber is 17 degrees.

Example 6

AB-PBO from 3-amino-4-hydroxybenzoic acid and the polyamide of Example 1 were weighted using 69.5 g of polyamide in MSA and 139.8 g of AB-PBO (intrinsic viscosity: 8.8 L / g) in PPA. Prepare a quaternary spinning stock containing 66/34 (volume ratio 60/40). AB-PBO / PPA stocks are high in viscosity and cannot be mixed with polyamide / MSA solutions until heated to 70 ° C., when a homogeneous stock is prepared. The stock solution is removed from the mixer to fill the spinning cell. The amount of discharge through the air gap of 0.7 inch is 0.02 ml / min per hole, but the winding speed is 2.0 m / min and spun at 70 ° C. T / E / M tensile properties of the dried composite fibers are 2.3 gpd / 12.5% / 36 gpd. The orientation angle of the fiber is 45 degrees.

Example 7

A quaternary spinning stock containing 3.0 wt% (60 wt% PBT / 40 wt%) of the polyamide solid of Example 1 in 97 wt% (50 wt% MSA / 50 wt% PPA) of mixed solvent had a concentration in MSA / PPA. A polyamide solution of Example 1 having a value of 1.35 wt% (55.9 wt% MSA / 44.1 wt% PPA) and a PBT solution (extreme viscosity: 17.0 L / g) having a concentration of 14.9 wt% in PPA. Prepare as follows: Mix 110.2 g of MSA and 87.0 g of PPA together in a glass jar using a magnetic stirrer coated with "Teflon" at room temperature. 2.7 g of polyamide is added to a mixed solution of MSA / PPA and stirred at room temperature. Pour the solution into the Atlantic Mixer. Subsequently, 27.3 g of PBT / PPA stock solution is added to the mixer, which is operated at low speed under vacuum without external heating (to degas). PBT / PPA stock is gradually ground and "dissolved" in polyamide MSA / PPA solution.

The next day, there is still a small amount of PBT / PPA stock solution adhering to the top of the mixer blade. Collecting PBT / PPA stock lumps into the remaining spinning stock and continuing mixing until the next day results in a homogeneous mixture of gel-like consistency. Transfer to a Class 4 spinning stock spinning cell, using 10 spinnerets with a diameter of 0.005 inch, and using a spin-elongation factor of 4.0, air gap spinning at room temperature at 12.6 m / min (air gap: 0.25 inch) [10-spinning spinnerets with a hole diameter of 0.010 inch, also air gap spinning at room temperature with 2.0, 4.0 and 6.0 m / min with spin-elongation coefficients of 2.5, 5.0 and 7.6, respectively (air gap: 0.25 inch) To make it work. The discharge amount is 0.04 m / min per hole. To completely remove the acid solvent, the bobbins of the yarn are immersed in water (extraction solvent) overnight and then air dried. The tensile properties (denier, strength, elongation, elastic modulus) of the spun yarn (PBT / polyamide, weight ratio 60/40 or volume ratio 52/48) are 39 denier, 2.2 gpd, 6.3%, 113 gpd. The orientation angle measured by wide-angle X-ray diffraction is 40 degrees. Insufficient degassing due to relatively low tensile properties.

Example 8

A quaternary spinning stock containing 5.8% by weight (60% by weight PBT / 40% by weight ABPBI) in 94.2% by weight (79% by weight MSA / 21% PPA) of solvent was prepared using an ABPBI solution having a concentration of 3.0% by weight in MSA. Prepared from the same PBT / PPA stock solution as in Example 1. Prepare as follows: 4.8 g of ABPBI, poly-2,5 (6) -benzimidazole (high viscosity: 5.17) polymer, measured in 0.5 g / 100 ml of sulfuric acid was added to 155.2 g of MSA in glass jar, and "Teflon Stir at 60 ° C. using a magnetic stirrer covered with ". The solution is extremely viscous. Pour the solution into the Atlantic Mixer. Then 48.0 g of the pulverized product of PBT / PPA stock is added to the mixer while running the mixer (to degas) at low speed at 50 ° C. PBT / PPA stock is gradually comminuted and "dissolved" in ABPBI / MSA solution. Continue mixing until the next day. Transfer the spinning stock solution to the spinning cell, air gap at room temperature at 12.6 m / min using a spinneret with 10 holes with a diameter of 0.005 inch and a spin-elongation coefficient of 4.0 that can withstand the spun spin-stretch Spin (air gap: 0.25 inch). The discharge amount is 0.04 ml / min per hole. Since there are many air pockets, the discharge amount is increased to 0.08 ml / min per hole, and yarns are spun at 7.5 m / min with a spin-elongation coefficient of 1.2. To completely remove the acid solvent, the bobbins of the yarn are immersed in water (extraction solvent) overnight and then air dried. The tensile properties (denier, strength, elongation, elastic modulus) of the spun filament (PBT / ABPBI, weight ratio or volume ratio 60/40) are 9.8 dpf, 6.2 gpd, 10.7%, 272 gpd. The orientation angle of the spun fiber is 31 degrees.

Example 9

A unidirectional test rod was prepared by winding around a 7 inch by 7 inch by 0.25 inch plate with the PBT / polyamide yarn of Example 1 so that the yarns were placed in parallel and the total thickness was 3.5. Polyimide film coated with a release agent ("Frekote 33") before and after winding the yarn [E. children. Dupont de Nemore and Company, Incorporated; "Kapton"] layer is placed on the plate. Finally, a thin metal sheet is placed on both sides of the structure. The entire assembly is then heated and compressed at 315 ° C. and 6,000 lbs (122 psi) for 15 minutes. Two attachment films are obtained. Strips of 0.25 inch by 6.0 inch are cut parallel to the fiber direction and 4.8 g of strips are stacked inside an H-shaped mold with open ends. A male with a shim thickness of 0.118 in. Was initially pressed at 300 lbs (200 psi) and then raised to maximal 5,400 lbs (3,600 psi) at 315 ° C and released during the cooling period. The resulting softness / elasticity of the 0.25 inch × 6 inch × 0.113 inch rod is 42 kpsi / 9.6 mpsi, and the short beam shear strength is 2.4 kpsi. A thin strip about 0.78 mm thick is removed from the rod. Its orientation angle is 13 degrees.

Example 10

Direct winding techniques are also used to make unidirectional test rods. The same H-type mold is installed on a rotating shaft and the PBT / polyamide yarn of Example 2 is wound into a terminal open shape of 0.25 inch by 6.0 inch area on both sides of the mold. After winding 4.7 g of yarn, the solidified part is placed on both sides of the mold and cold pressed to 5,000 lbs to compress the fibers into two rods. The exposed fiber ends at both ends of the mold are cut with a razor. The mold is then opened, the two rods stacked together, and hot pressed into the mold at 315 ° C. and 5,000 lbs (3,333 psi) for 20 minutes using a 0.1195 in thick wand. The initial cooling pressure used was only 500lbs, but the pressure during cooling was maintained at 6,000bs. The final dimension of the rod is 0.1035 in x 0.25 in x 6 in. The softness / elasticity measured using a short beam shear strength (SBSS) of 4.4 kpsi is 54 kpsi / 8.8 mpsi. A thin strip about 0.68 mm thick is removed from the rod. Its orientation angle is 11 degrees.

The successful preparation of the coating layer on the mold by extraction and drying methods facilitates the production of complex reaction system complexes from quaternary stock solutions. A small cylinder is made by coating a stainless steel rod with a stock solution of the invention containing 15% solids. Each coating is extracted by washing in water and then drying with a hot air gun. After the four coatings were applied, the cylinder was solidified at 315 ° C. using a hot air gun.

Fibrids are prepared by mechanically precipitating (5 g of the stock solution of the present invention 5 g of the stock solution in 300 mls of water in a Waring blender) to prepare fibrids, and to prepare small paper samples. 0.5 g of fibrids in 500 ml of water are prepared in a mixer. The slurry is filtered using filter paper No. 40 in a Buchner funnel with a diameter of 9 cm. The wetland, about 3 inches in diameter, is then cold pressed to 8.000 lbs pressure. Films are prepared by solidifying the paper at 315 ° C. and 100 psi.

Claims (8)

Poly-p-phenylenebenzobisthiazole, poly-p-phenylenebenzobisoxazole and poly-2,5-benzoxazole in a solvent mixture of polyphosphoric acid with methanesulfonic acid or chlorosulfonic acid or an equivalent strong acid And a polymer mixture of 5 to 70% by weight of the first polymer selected from 30 to 95% by weight of the second polymer selected from the thermoplastic polymer and the difficult to process polymer, wherein the concentration of the polymer mixture in the solvent mixture is at least 1% by weight. Grade stock. The quaternary stock solution of claim 1 wherein the second polymer is a thermoplastic polymer. The quaternary stock solution according to claim 2, wherein the thermoplastic polymer is polyamide. The quaternary stock solution according to claim 1 or 2, wherein the weight ratio of polyphosphoric acid to methanesulfonic acid or chlorosulfonic acid is 40:60 to 60:40. Poly-p-phenylenebenzobisthiazole, poly-p-phenylenebenzobisoxazole or poly-2,5-benzoxazole in polyphosphoric acid in a solution of thermoplastic or difficult to process polymer in methanesulfonic acid or chlorosulfonic acid A method of preparing a quaternary stock solution according to claim 1, comprising adding a solution of and then shear mixing the mixture. Fiber spun from the stock solution of claim 1. Fibrids prepared from the stock solution of claim 1. A composite product obtained by winding a fiber spun from the stock solution of claim 2 into a molded article and then compression molding it by heating.