KR20100071572A - Method for producing aromatic polyamide polymer having lightfastness - Google Patents

Abstract

PURPOSE: A producing method of a para-type aromatic polyamide polymer with the inherent viscosity over 5.5 is provided to form a polyamide fiber including the excellent mechanical property. CONSTITUTION: A producing method of a para-type aromatic polyamide polymer comprises the following steps: forming a polymerization solvent by mixing an N-methyl-2-pyrrolidone solution with calcium chloride; forming a solution by dissolving p-phenylene diamine into the polymerization solvent, and cooling the solution; adding terephthalic chloride to the solution; and inserting a diamine component including a piperidyl group. 7~10wt% of calcium chloride is added to the N-methyl-2-pyrrolidone solution.

Description

Method for producing aromatic polyamide polymer having light stability [Method for producing aromatic polyamide polymer having lightfastness}

The present invention relates to a method for producing a para-type aromatic polyamide polymer having high light stability and intrinsic viscosity, and specifically, N-methyl-2-pyrrolidone (hereinafter referred to as NMP). It relates to a method of dissolving calcium chloride, adding an aromatic diamine and an aromatic dicarboxylic acid halide thereto, and further adding a third diamine component to produce a poly (p-phenylene terephthalamide) polymer.

High molecular weight polymers with an intrinsic viscosity of at least 5.5 are essential for the production of high strength para-type aromatic polyamide fibers (para-type aramid fibers). In order to prepare high molecular weight para type aromatic polyamide polymer having an intrinsic viscosity of 5.5 or more, the content of poly (p-phenylene terephthalamide) (poly (p-phenyleneterephtalamide, PPTA) to the polymerization solvent serves as an important factor. It is controlled by the content of additives, the equivalent ratio of monomers p-phenylenediamine (PPD) and terephthalic acid chloride (TPC), and is affected by the type and structure of the polymerization reactor.

Until now, para-aromatic polyamides, which are condensers of para-aromatic diamines and para-aromatic dicarboxylic acid halides, have high strength, high modulus and high heat resistance, and not only have cold-resistance, which is characteristic of fibers at -160 ° C, but also insulation. It is known as a high-tech material with excellent chemical resistance and all.

Representative para-type aromatic polyamide compounds include poly (p-phenylene terephthalamide) (PPTA). Generally, poly (p-phenylene terephthalamide) is polymerized by the polycondensation reaction of terephthalic acid chloride (TPC) and p-phenylerylenediamine (PPD) solution in an amide solvent. However, since poly (p-phenylene terephthalamide) has very low solubility in organic solvents, solvent selection, monomer concentration, etc. are very important to obtain a high molecular weight polymer.

The poly (p-phenylene terephthalamide) thus prepared is a uniaxially oriented para-type wholly aromatic polyamide, which is vulnerable to daylight due to its molecular structure. Therefore, poly (p-phenylene terephthalamide) fibers prepared from poly (p-phenylene terephthalamide) have a problem in that deterioration of physical properties and discoloration occurs when exposed to sunlight for a long time.

It is an object of the present invention to provide a method for producing a para-type aromatic polyamide polymer having an intrinsic viscosity of 5.5 or more and light stability.

In order to solve the above problems, according to a preferred embodiment of the present invention, A) preparing a polymerization solvent by mixing calcium chloride in N-methyl-2-pyrrolidone solution; B) dissolving p-phenylenediamine in the polymerization solvent to prepare a solution and then cooling; C) partitioning and adding terephthalic acid chloride to the solution; And D) adding a diamine component having a piperidyl group to provide a method for producing a poly (p-phenylene terephthalamide) polymer.

According to another suitable embodiment of the present invention, the calcium chloride is added in an amount of 7 to 10% by weight based on N-methyl-2-pyrrolidone.

According to another suitable embodiment of the present invention, the concentration of the poly (p-phenyleneterephthalamide) polymer in the solution is 8 to 15% by weight.

According to another suitable embodiment of the present invention, the diamine having a piperidyl group is triacetonediamine or a derivative thereof, characterized in that 0.1 to 1.0 mol% of the poly (p-phenylene terephthalamide) polymer is added. .

The para-type aromatic polyamide polymer according to the present invention has an intrinsic viscosity of 5.5 or more, and the polyamide fibers produced using the polymer according to the present invention have improved light stability with excellent mechanical properties.

Hereinafter, the present invention will be described in detail.

The para-type aromatic polyamide polymer of the present invention is prepared by dissolving para-type aromatic diamine in a polymerization solvent, followed by condensation polymerization by addition of para-type aromatic dicarboxylic acid halide.

Aromatic diamines usable in the present invention include p-phenylenediamine, 4,4'-diaminodiphenyl, 2-methyl-p-phenylenediamine, 2-chloro-p-phenylenediamine, 2,6-naphthalene Diamine, 1,5-naphthalenediamine, 4,4'-diaminobenzanilide, and the like can be used.

Aromatic dicarboxylic acid halides that may be used in the present invention are also terephthaloyl chloride, 4,4'-benzoyl chloride, 2,5-dichloro terephthaloyl chloride, 2-methyl terephthaloyl chloride, 2,6- Naphthalene carboxyl chloride etc. are mentioned.

The aromatic diamine and the aromatic dicarboxylic acid halide may be polymerized to prepare poly (p-phenylene terephthalate) which is a para-type aromatic polyamide.

In order to increase the solubility of the poly (p-phenylene terephthalamide) polymer, a salt compound such as calcium chloride or cerium chloride is added to N-methyl-2-pyrrolidone (NMP). It is preferable that the salt compound added is 7 to 10 weight% with respect to N-methyl- 2-pyrrolidone. If the concentration of calcium chloride is less than 7% by weight, the solubility of the poly (p-phenylene terephthalamide) polymer is poor and the degree of polymerization does not increase. If the concentration is more than 10% by weight, the excess calcium chloride inhibits the chain growth of the polymer, thereby increasing the intrinsic viscosity ( There is a problem that IV) is lowered.

In the present invention, a diamine component having a piperidyl group is added to impart light stability. The diamine used in the present invention may be triacetonediamine or a derivative thereof. The content of diamine added is suitably 0.1 to 1.0 mol% with respect to the para-type aromatic polyamide polymer. If the diamine content is less than 0.1 mol%, there is little effect of improving light stability, and if it is more than 1.0 mol%, there is a problem that the intrinsic viscosity of the polymerized para-type aromatic polyamide polymer is significantly lowered, which is not suitable.

In more detail, the solution is prepared by dissolving p-phenylenediamine (PPD) in a polymerization solvent prepared by adding calcium chloride to N-methyl-2-pyrrolidone (NMP). After cooling the prepared solution, terephthalic acid chloride (TPC) is added in two portions. Terephthalic acid chloride (TPC) may be added in two portions sequentially at a weight ratio of 30:70 to 40:60. Since TPC is very reactive, it is preferable to add it twice in order to obtain a polymer having uniform physical properties.

Next, a poly (p-phenylene terephthalamide) polymer can be prepared by adding a diamine having a piperidyl group and then reacting with stirring. The concentration of poly (p-phenyleneterephthalamide) in the solution is preferably 8 to 15% by weight. In this case, the intrinsic viscosity (IV) of a suitable polymer can be obtained. If the concentration is less than 8% by weight, or more than 15% by weight, it is difficult to obtain intrinsic viscosity (IV) 5.5 or more, which is required because of poor reactivity between monomers.

In the present invention, the polymerization reaction in which TAD is added may be represented by Scheme 1 below.

Scheme 1

N is preferably 50 or more for high degree of polymerization, and m has a range of 0.1 to 1.0 mol% based on the polymer.

In the following the present invention will be described in more detail based on examples. Intrinsic viscosity (IV) used as a criterion in Examples and Comparative Examples is defined as follows.

Intrinsic Viscosity = ln (t ₁ / t ₀ ) / C

Where t ₁ represents the flow time of the poly (p-phenylene terephthalamide) / sulfuric acid solution and t ₀ represents the flow time of the sulfuric acid itself. C is the poly (p-phenylene terephthalamide) / sulfuric acid solution. Poly (p-phenylene terephthalamide) concentration of

That is, 0.5 g of a poly (p-phenylene terephthalamide) polymer is dissolved in 100 ml of 96% sulfuric acid and the flow time is measured at 30 ° C. with a capillary viscometer.

≪ Example 1 >

250 kg of NMP / calcium chloride mixed solution containing 8.2% by weight of calcium chloride was added to the dray batch polymerization reactor, and then 15.9 kg of p-phenylenediamine was added with stirring. The mixture was then cooled to 20 ° C. While continuing cooling and vigorous stirring, 29.8 kg of terephthalic acid chloride was added rapidly in two portions at a ratio of 35:65. After 15 minutes, 105 g of triacetone diamine was added and stirred for about 1 hour to complete the reaction. At this time, the final temperature was cooled so as not to be 60 ℃ or more. The poly (p-phenyleneterephthalamide) polymer is contained in 11% by weight of the mixed solvent and has a crumb form. The crumb was triturated and neutralized to obtain poly (p-phenylene terephthalamide) having an intrinsic viscosity of 6.5 after filtration, washing and drying.

The prepared poly (p-phenyleneterephthalamide) polymer having an intrinsic viscosity of 6.5 was dissolved in 100.1% sulfuric acid at 19.5% by weight at 85 ° C., and then spun by an air-gap wet spinning method through a 1,000-hole spinning nozzle. The fineness was 1,500 deniers and the winder speed was 450 m / min. The tensile strength of the prepared fiber was 25g / d and elongation was 3.4% physical properties.

The finally produced poly (p-phenylene terephthalamide) fibers showed a bright golden color, and it was confirmed that even if it was left in sunlight for one month, it retained its own physical properties and colors.

Comparative Example 1

250 kg of NMP / calcium chloride mixed solution containing 8.2% by weight of calcium chloride was added to the dray batch polymerization reactor, and then 15.9 kg of p-phenylenediamine was added with stirring. The mixture was then cooled to 20 ° C. While continuing cooling and vigorous stirring, 29.8 kg of terephthalic acid chloride was rapidly added in two portions at a ratio of 35:65, followed by stirring for 1.5 hours to complete the reaction. The poly (p-phenylene terephthalamide) obtained in the same manner as in the following Example has an intrinsic viscosity of 6.7, and then a poly (p-phenylene terephthalamide) fiber was obtained through the same spinning method as in Example 1. The tensile strength of the obtained poly (p-phenylene terephthalamide) fiber was 26 g / d, and elongation obtained the physical property of 3.1%.

The final poly (p-phenylene terephthalamide) fiber obtained initially had a bright golden color as in the examples, but gradually changed color to dark yellow after exposure to sunlight, and changed to dark yellow after one month and was tensile. It was observed that the intensity dropped significantly to 18 g / d.

Claims (4)

In the method for producing a poly (p-phenylene terephthalamide) polymer, A) preparing a polymerization solvent by mixing calcium chloride with N-methyl-2-pyrrolodon solution; B) dissolving p-phenylenediamine in the polymerization solvent to prepare a solution and then cooling; C) partitioning and adding terephthalic acid chloride to the solution; And D) A method for producing a poly (p-phenylene terephthalamide) polymer comprising adding a diamine component having a piperidyl group. The method of claim 1, wherein the calcium chloride is added in an amount of 7 to 10% by weight based on N-methyl-2-pyrrolidone. The method according to claim 1, wherein the concentration of the poly (p-phenylene terephthalamide) polymer in the solution is 8 to 15% by weight. 2. The poly (p-phenyl) according to claim 1, wherein the diamine having a piperidyl group is triacetonediamine or a derivative thereof, and 0.1 to 1.0 mol% is added to the poly (p-phenylene terephthalamide) polymer. Lenterephthalamide).