JP2002212886A - Method for modifying molding from rigid chain polymer solution - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a rigid polymer molding having excellent characteristics of designe, light resistance, adhesiveness, and abrasion resistance. SOLUTION: In this method for processing the rigid polymer molding a polybenzazole molding containing >=30% nonsolvent is modified by a cheese dyeing method, a hank dyeing method, or a module method. In this method for processing a condensate is formed in the inside of the rigid polymer molding during processing.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a design, light fastness,
The present invention relates to a method for producing a rigid polymer molded article having excellent adhesion and wear resistance.

[0002]

BACKGROUND OF THE INVENTION With respect to fibers, para-aramid fibers and polybenzazole fibers are representatives of the currently marketed super fibers. However, in these rigid polymer molded articles, the polymer chains are densely packed, so that the dye hardly enters the inside of the molded article and cannot be deeply dyed. In addition, it is difficult to form a composite with a sufficient adhesive strength with another resin regardless of a method such as decoration of a functional group of a polymer, surface coating of a molded article, or physical modification of a surface.

Japanese Patent Application Laid-Open No. Hei 8-226080 discloses a method for impregnating an undried polybenzazole fiber with an iodine compound, a dye or the like as a means for improving the light resistance. In this method, it is possible to impregnate the additive into the polybenzazole molded body in a short time and then to confine it in the molded body by drying, but it is possible to proceed with the condensation reaction in the molded body in an undried state. Advanced processing has not been achieved. Japanese Patent Application Laid-Open No. 12-234265 discloses a technique for applying a light-resistant agent to an undried molded body in a short time of 10 minutes or less. In this method, in order to enable application in a short time, it is necessary to use a solution having a very high concentration to increase the concentration difference from the inside of the molded body. It is necessary to wash away a large amount of the treatment liquid by washing with water after the application, and there is a problem that a large amount of a light-fast agent waste liquid is generated in industrial production. Further, if the post-washing after application is insufficient, problems such as color transfer of the unoxidized condensation monomer remaining on the fiber surface occur.

[0004]

Although it is a rigid polymer molded product having physical properties extremely suitable as an industrial material, its usefulness is further enhanced when light resistance, dyeing properties and adhesion are improved. Therefore, the present inventors have high strength, high elastic modulus, high heat resistance, and light resistance, while being lightweight, and have excellent design properties,
As a result of intensive research on a processing method for obtaining a rigid polymer molded body having improved adhesion, the following invention was completed.

[0005]

That is, the present invention relates to a process for processing a rigid polymer molded product in which a polybenzazole molded product containing at least 30% of a non-solvent is modified by a cheese dyeing method, a shackle dyeing method or a module method. Method. Further, there is provided a processing method characterized in that a condensate is generated inside the rigid polymer molded body during processing.

Hereinafter, the present invention will be described in more detail. The rigid polymer in the present invention refers to a polymer in which most of the main chain is composed of bonds between molecules having small flexibility close to a para bond of an aromatic ring, specifically, aromatic polyimides and para-aramid. And polybenzazoles. The polybenzazole molded product is a polyparaphenylene benzobisoxazole (PBO) homopolymer and a random, sequential or block copolymer with polybenzazole (PBZ) containing substantially 85% or more of a PBO component. Say. Here, polybenzazole (PBZ) polymer is described in, for example, "Liquid Cry" by Wolf et al.
stalline Polymer Compositions, Process and Product
s "U.S. Patent No. 4,703,103 (October 27, 1987),
`` LiquidCrystalline Polymer Compositions, Process
and Products, U.S. Patent No. 4,453,692 (August 6, 1985), "Liquid Crystalline Poly (2,6-Benzothiazol)
e) Compositions, Process and Products '' U.S. Patent No. 45
33724 (August 6, 1985), "Liquid Crystallin
e Polymer Compositions, Process and Products, U.S. Pat. No. 4,453,693 (August 6, 1985);
ermooxidativelyStable Articulated p-Benzobisoxazol
e and p-Benzobisoxazole Polymers '' U.S. Pat.
No. 7 (November 16, 1982), Tsai et al., Method fo
r making Heterocyclic Block Copolymer '' U.S. Patent No. 45
No. 78432 (March 25, 1986).

The structural units contained in the PBZ polymer are preferably selected from lyotropic liquid crystal polymers. The monomer units consist of the monomer units described in Structural Formulas (a)-(h), and more preferably consist essentially of the monomer units selected from Structural Formulas (a)-(c).

[0008]

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[0009]

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Suitable solvents for forming the dope of the polymer consisting essentially of PBO include cresol and non-oxidizing acids capable of dissolving the polymer. Examples of suitable acid solvents include polyphosphoric acid, methanesulfonic acid and high concentrations of sulfuric acid or mixtures thereof. Further suitable solvents are polyphosphoric acid and methanesulfonic acid. The most suitable solvent is polyphosphoric acid.

The concentration of the polymer in the solvent is preferably at least about 7% by weight, more preferably at least about 10% by weight.
%, Most preferably 14% by weight. The maximum concentration is limited by practical handling properties such as, for example, polymer solubility and dope viscosity. Due to these limiting factors, the polymer concentration does not exceed 30% by weight.

[0012] Suitable polymers, copolymers or dopes are synthesized by known techniques. See, for example, Wolfe et al., US Pat. No. 4,453,693 (August 6, 1985); Sybert et al., US Pat. No. 4,772,678 (September 20, 1988);
Synthesized by the method described in US Pat. No. 4,847,350 to ris (July 11, 1989). Polymers consisting essentially of PBO are disclosed by Gregory et al. In US Pat.
According to this method, it is possible to increase the molecular weight at a high reaction rate under relatively high temperature and high shear conditions in a dehydrating acid solvent.

The dope polymerized in this way is supplied to the extruding section, and is discharged from the extrusion die at a temperature of usually 100 ° C. or higher. The polymer dope requires a sufficient draw zone length as described in U.S. Pat. No. 5,296,185 to obtain a sufficient draw ratio (SDR), and has a relatively high temperature (spinning at or above the solidification temperature of the dope). It is preferable that the cooling air is uniformly cooled by the rectified cooling air having a temperature equal to or lower than the temperature. The length (L) of the draw zone needs to be a length that completes solidification in a non-coagulating gas, and is roughly determined by the single hole discharge amount (Q). Depending on the viscosity coefficient of the solvent and the type of polymer, it is possible to use isothermal spinning with a short air gap. Furthermore, when extruding the precursor before forming the rigid unit, a wet spinning method is also possible.

The stretched polymer solution is then directed to an extraction (coagulation) bath. Since the stretched material has a high viscosity coefficient, no consideration is required for disturbance of the extraction bath, and any type of extraction bath may be used. For example, funnel type, water tank type, aspirator type or waterfall type can be used. The extract is desirably a phosphoric acid aqueous solution or water. Finally, the phosphoric acid contained in the polymer in the extraction bath is 99.0% or more, preferably 99.0% or more.
Extract 5% or more. The liquid used as the extraction medium in the present invention is not particularly limited, but is preferably water, methanol, ethanol, acetone, or the like, which has substantially no compatibility with polybenzazole. Also extraction (coagulation)
The bath may be separated into multiple stages, the concentration of the phosphoric acid aqueous solution may be gradually reduced, and finally, the surface may be washed with water. Further, it is desirable that the molded body from which most of the solvent has been extracted is neutralized with an aqueous sodium hydroxide solution, aqueous ammonia, sodium carbonate or the like, and washed with water.

[0015] The method of processing a rigid polymer other than polybenzazole differs from that of polybenzazole due to the different fluid properties of the spinning solution. Forming methods include a wet method in which the dope is extruded directly into the coagulation liquid, and a dry-wet method in which the gap between the coagulation bath and the nozzle is set to several centimeters and the temperature of the nozzle is set higher than the temperature of the coagulation bath. it can.

The rigid polymer molded body washed with water usually contains an extract having a volume fraction of 50% or more by replacing the solvent with the extract. When the extract is water, the fiber contains 35% or more by weight of water inside the fiber. An important requirement of the present invention is that the molded product is wound on cheese or a shackle without drying the extract, and is immersed in the extract, such that the rigid polymer molded product contains 30% or more of the extract. Need to be kept. When a fluid other than the extract is used as the solvent of the treating agent in the post-processing step, an appropriate rigid polymer molded body is replaced with a fluid that becomes a non-solvent. The non-solvent after the substitution is preferably at least 30% by weight. If the amount of the non-solvent is smaller than this, the pores on the polymer surface become thinner, and it becomes difficult to absorb a treating agent having a large molecular size. Alternatively, it becomes difficult to quickly absorb the treating agent.

A large number of fine holes called capillaries are present inside a polybenzazole molded article containing a large amount of non-coagulated liquid, and the non-coagulated liquid of the pre-dried molded article is in this capillary. Moreover, the holes are connected to each other and communicate from outside to inside. Mass transfer can be performed using the connected capillaries, and the treatment agent can be guided to the inside in a relatively short time. In the case of a polybenzazole molded article containing a non-coagulated liquid of 30% or more, the immersion time when applying a treatment agent is 1 second or more, more preferably 2 seconds or more in the case of a molded article having a diameter of 10 microns.
Most preferably, a sufficient amount of the treating agent can be applied for as long as 5 seconds or more, but if the molecular weight of the treating agent is large or the viscosity of the treating agent solution is high, the treating agent is further reacted. In the case of performing more advanced post-processing, it takes at least 20 seconds, and depending on the type of processing, several minutes to several tens of minutes. However, these are cases where fibers in the form of yarn are brought into contact with the treatment liquid, and the present invention requires a longer treatment for the following reasons.

As a feature of the present invention, it is possible to apply a required amount of a treating agent without post-washing by lowering the concentration of the treating solution and adsorbing the treating agent inside the molded body over time. Become. It is important to impregnate the pores inside the molded body with the treating agent instead of the gaps and surfaces formed on the surface of the molded body by the cheese dyeing method, the shackle dyeing method, or the module method. If the concentration of the treatment liquid is high, the treatment agent may precipitate on the surface of the molded body and impregnation inside the molded body may be rather delayed. Since a sufficient amount of the processing agent is supplied to the surface of the inner layer molded body of the cheese and the shackles and sufficient time is required for impregnation of the pores inside the molded body, the processing time is at least 1 hour. Preferably, three hours or more are required. A molded article treated under such conditions is provided with a sufficient amount of treating agent uniformly inside. In addition, since there is little surplus processing agent on the surface of the molded product, post-water washing is easy, and not only the amount of the processing agent that is washed out and wasted can be reduced, but also the process is environmentally friendly.

When the treating agent is simply impregnated, it is possible to treat the solvent-extracted molded product of polybenzazole in-line. Further, in a process such as disclosed in JP-A-11-131326, in which a continuum can be deposited on a net conveyor to increase the processing time, advanced processing can be performed in-line. Even in the case of a polybenzazole molded product having a non-solvent content of 30% or more before drying, when a sufficient amount of the treating agent is diffused into the molded product or when the reaction takes time in the molded product, the processing apparatus is used. Therefore, it is necessary to treat a continuous molded body once after winding it against a cheese, a shackle or a roll. At this time, it is necessary to take measures such as winding a wind pattern, a shackle width, and a spacer for liquid passage so that the solution containing the treating agent can sufficiently contact the surface of the formed body. The cheese dyeing method, shackle dyeing method, and module method of the present invention are defined as a method of impregnating the inside of a molded product with a treating agent. That is, the cheese dyeing method means that a fibrous formed body is immersed in a solution of a wrapping treatment agent so as to form a twill on a yarn tube. The shackle dyeing method means that the molded body wound around the shackle is bound or partially tied, then removed from the shackle and immersed in a solution of the treating agent. The modular method is a spacer for liquid passage. Means a method of contacting with a processing liquid in a state where the moldings are combined and laminated.

Various processing examples of the polybenzazole molded article will be described. First, we will discuss ways to improve lightfastness. Examples of the treatment agent for improving the light resistance of the polybenzazole fiber include an oxidation dye compound that oxidizes with an oxidizing agent containing air to form a color, a compound composed of an aromatic amine or a compound composed of phenols, but is not limited thereto. is not. Oxidation dye is not a dye that uses a dye synthesized by oxidation, but an intermediate that generates a dye by oxidation.Strictly speaking, it is a base that generates an oxidation dye, and is also called an oxidation base. Things. Examples of the compound comprising an aromatic amine or a compound comprising a phenol include aniline, o-phenylenediamine, m-phenylenediamine, p-phenylenediamine, o-aminophenol, m-aminophenol, p-aminophenol, naphthol, and Their derivatives,
And acid salt compounds thereof. Generally, such a compound is a solid or a liquid, and is used by dissolving it in a solvent. As the solvent to be dissolved, water, an aqueous solution such as a phosphoric acid aqueous solution, ethanol, methanol, alcohols such as ethylene glycol, ketones such as acetone, and the like, as long as they have compatibility with the light-fast agent and penetrate into the fiber. good.

As a specific method of using the solution to improve the light resistance of the rigid linear polymer molded article, a solution of one or more compounds described above is prepared. The concentration of the solution depends on the weight of the rigid polymer molded article and the bath ratio to be charged into the treatment apparatus, but it is necessary that the concentration is at least an amount that can exhibit light resistance when at least all the treatment agents are absorbed. If the treatment solution of the lightfast agent is close to the saturation concentration, a large amount of oxides will adhere to the treatment apparatus and the loss of the treatment agent will increase. Therefore, the concentration is preferably lower than the saturation concentration at the treatment temperature. In addition, when the oxide of the treating agent accumulates on the surface of the compact, the penetration of the treating agent into the inside of the compact slows down. Therefore, it is also effective to use a reducing agent such as sodium sulfite together. More preferably,
It is preferable that the concentration is low so that the load of washing away the excess processing agent is reduced as much as possible. At the stage where the compound has penetrated into the inside of the molded article, it is necessary to promote oxidation / condensation using aeration or an oxidizing agent. As the additive for promoting the oxidation and condensation of the light stabilizer, sodium hypochlorite, hydrogen peroxide, iron (iii) chloride, sodium nitrite, and the like can be used. The light stabilizer oxidized by this treatment reacts or adsorbs with the rigid linear polymer molded article, and becomes hard to fall off even if washed with water even in a porous state containing a large amount of non-solvent. In the present invention, a sufficient oxidative condensation reaction can be advanced while the rigid linear polymer molded article is immersed in the liquid for a long time on a scale industrially practicable such as a cheese dyeing method.

After washing with water, drying (heat treatment) is performed under heating conditions within a temperature range from room temperature to 300 ° C., whereby the connection between the capillaries is lost, and the light stabilizer can be easily fixed inside the fiber. When heated while containing a non-coagulant such as water, hydrolysis may occur with para-aramid or polybenzazole, etc.
Even when the strength lost at that time increases from several percent to several tens of percent, the residual strength after light exposure is higher than that of the non-light-resistant product, and the practical performance is improved under outdoor use conditions.

Next, the improvement of the design of the rigid polymer by the pigment will be described. The improvement in design is achieved by changing the hue, touch, texture, friction characteristics, antistatic, and antifouling. Dispersions such as carbon black, titanium oxide, kaolin, and talc, and antistatic agents can be used. After the extraction of the rigid polymer with the solvent, many holes called capillaries are present inside the molded body, and it is possible to impregnate fine inorganic particles. In particular, it is preferable to impregnate silica particles, colloidal alumina, or the like from the surface in order to improve the friction resistance of the rigid polymer. The shape and size of the pigment and the inorganic particles are arbitrary, but particles of several tens to several hundreds of nanometers and nearly monodisperse are preferred. The dispersion medium and concentration of the dispersion can be arbitrarily set, but a combination with a small load of post-washing is preferred.

Further, a method for producing a composite material using the sol-gel method will be described. By impregnating an undried molded product of a rigid polymer with an alcohol solution of tetraethyl silicate and an amine catalyst, and drying at 200 ° C to 350 ° C,
A composite of silica and a rigid polymer can be produced. The organic-inorganic composite material thus obtained is characterized in that the lateral compression characteristics of the fibrous material are improved.

Hereinafter, the measuring method used in the present invention will be described. <Evaluation method of light fastness> The light fastness was evaluated by measuring the strength of the molded body before and after light exposure. The light exposure test used a water-cooled xenon arc type weather meter (model Ci35A) manufactured by Atlas. A molded body is wound around a metal frame and set in an apparatus. Quartz is used for an inner filter glass, porosicate is used for an outer filter glass, and type S is used. Irradiance is 0.35 W / m2 (at 340n).
m), black panel temperature 83 ± 3 ° C, humidity 5 in test chamber
The continuous operation was performed for 100 hours under the conditions of 0 ± 5%.
When the molded body is wound around a metal frame, it is stretched in the opposite direction using a 0.80 mm thick stainless steel scale on the light-exposed surface and subjected to three bending treatments, resulting in a kink band (damage) on the molded body. I was sorry.

<Measurement Method of Strength> The strength of a molded product, particularly a fiber, was measured by a tensile tester (model AG-50KNG, manufactured by Shimadzu Corporation) according to JIS-L1013. still,
When the sample was mounted, an initial load of (denier / 10) gf was applied, and a tensile test was performed with the slack removed.

[0027]

The present invention will be described in more detail with reference to the following Examples, but it should not be construed that the invention is limited thereto. Example 1 14.0% by weight of polyparaphenylene benzobisoxazole having an intrinsic viscosity of 28.4 dL / g measured with a methanesulfonic acid solution at 30 ° C., obtained by the method described in US Pat. No. 4,453,693. A spin dope consisting of polyphosphoric acid having a phosphorus pentoxide content of 84.3% was used for spinning. The dope is passed through a metal mesh filter medium, and then kneaded and defoamed with a kneading device consisting of two shafts, and then the pressure is increased. After spinning at 177 ° C. and cooling the discharged yarn using cooling air at a temperature of 60 ° C., the yarn was wound around a godet roll to give a spinning speed, and the temperature was maintained at 50 ° C. 22%
Was introduced into an extraction (coagulation) bath composed of a phosphoric acid aqueous solution. Subsequently, the yarn is washed with ion-exchanged water in a second extraction bath, immersed in a 0.1 mol / L sodium hydroxide solution to perform a neutralization treatment, and then washed with water, and a porous resin bobbin having a diameter of 104 mm. At a speed of 150 m / min. A solution prepared by dissolving 25 g of each of m-phenylenediamine and p-phenylenediamine in 30 L of water was placed on the apparatus shown in FIG. 1, the wound polyparaphenylenebenzobisoxazole fiber was added, and the solution was circulated for 60 hours. The solution prepared first was brown, but the solution after circulation for 60 hours was transparent, indicating that almost all of the treating agent was adsorbed on the fibers. Take out the fiber from the device,
Let dry for hours. The strength of the obtained fiber is 37 cN / d
Tex. This fiber was subjected to three-fold bending treatment and evaluated for light resistance. As a result, the residual strength after irradiation with a xenon light source for 100 hours was 21 cN / dTex.

<Comparative Example 1> In Example 1, following the water washing after the neutralization treatment, the yarn was guided to a cabinet incorporating a pair of Nelson rollers, and 2.5% meta-phenylenediamine and 2.5% para. After impregnating for 15 seconds while dropping the mixed aqueous solution of phenylenediamine on the fiber on the roller, perform water washing in another water washing cabinet for 10 seconds,
It was picked up by a winder. The obtained polyparaphenylene benzobisoxazole fiber was dried at 80 ° C. for 4 hours. The fiber strength after the light resistance test at 37 cN / dTex was 17.5 cN / dTex. In this method, the liquid in the final washing cabinet was markedly colored, and 400 L of a low-concentration waste liquid of phenylenediamine was generated in a two-hour experiment. In this method, since the process is a continuous process, the productivity of the fiber is high, but the high-concentration processing liquid attached around the running yarn is often taken out, so that the cost of waste liquid treatment and the like increases, and industrial implementation is extremely difficult. .

<Example 2> In the same manner as in Example 1, 300 g of undried polyparaphenylene benzobisoxazole fiber was wound around a porous bobbin, and monodispersed spherical particles having an average particle diameter of 100 nm were set on the apparatus shown in FIG. 10 g of silica fine particles
And 40 L of water, and the mixture was circulated for 6 hours, and then aged at 120 ° C. for 2 hours to obtain polyparaphenylene benzobisoxazole fiber. The obtained fiber is referred to as International Patent Number WO
A wide multifilament spread sheet was obtained by performing the spread processing described in No. 97/41285.

Example 3 The polyparaphenylene benzobisoxazole fiber wound by the method described in Example 1 was wrapped around a 1.125 m circumference and bound to form a ring-shaped 2 fiber.
50 g of undried product were obtained. This was immersed in 2 L of a 0.5% ammonia aqueous solution for 20 seconds, taken out, and immersed in an alcohol solution of tetraaethyl silicate for 4 hours. The polyparaphenylene benzobisoxazole fiber was attached to the shackles again, and the yarn was guided to a heating roller at 300 ° C. and dried to form silica inside the fiber and on the surface layer.

[0031]

According to the present invention, since a light-fast agent, a dye, a pigment, and a lubricant can be fixed to a rigid polymer molded article, the practical use as an industrial material is enhanced, and the field of application is greatly expanded. Further, an organic-inorganic hybrid material can be provided in combination with the sol-gel method.

[Brief description of the drawings]

FIG. 1 shows an example of a cheese dyeing apparatus. 1: Twill wound fibrous undried molded body. 2: Porous bobbin having water permeability. 3: bobbin stopper. 4: Treatment liquid circulation pump.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3B154 AA06 AB10 AB11 BA07 BA60 BB32 BB43 BC02 BC06 BC18 BD01 BD20 BE05 DA07 DA08 DA15 4H057 AA02 BA81 DA01 DA34 EA01 GA07 4L033 AA06 AC15 BA96

Claims (5)

[Claims] 1. A method for dyeing a rigid linear polymer molded article, which comprises cheese-dying a rigid linear polymer molded article containing 30% or more of a non-solvent. 2. A method for dyeing a rigid linear polymer molded article, comprising binding a rigid linear polymer molded article containing 30% or more of a non-solvent. 3. A method for modifying a rigid linear polymer molded article comprising modifying a rigid linear polymer molded article containing 30% or more of a non-solvent by a module method. 4. The method for processing a rigid linear polymer molded article according to claim 1, wherein a condensate is generated inside the rigid polymer chain molded article during the processing. 5. The method for processing a rigid linear polymer molded article according to claim 1, wherein the rigid linear polymer is polybenzazole.