KR20150030162A - Polyamide resin - Google Patents

Abstract

A polyamide resin of the present invention is obtained by poly condensation of dicarboxylic acid compound and diamine compound. The ratio (concentration of phosphor compound/concentration of terminal amino group) of concentration (μmol/g) of phosphor compound contained in the polyamide resin and the concentration (μmol/g) of terminal amino group of the polyamide resin is characterized by being 0.5 to 1.0. The polyamide resin has excellent anti-thermal discoloration.

Description

POLYAMIDE RESIN [0002]

The present invention relates to a polyamide resin. More specifically, the present invention relates to a polyamide resin having excellent heat discoloration resistance and a method for producing the same.

Polyamide resins are widely used as materials for industrial materials, engineering plastics, and the like because of their excellent physical properties and easy melt molding. 2. Description of the Related Art In recent years, there has been a demand for a polyamide resin having excellent physical properties and functions that can be used in fields such as electric and electronic parts, automobile parts, and reflective materials. Particularly, development of a polyamide resin excellent in heat discoloration resistance that does not discolor under polymerization or heating conditions under molding processing is desired.

Japanese Patent Application Laid-Open No. 2000-204244 (Patent Document 1) discloses a process for producing a polyester containing a dicarboxylic acid unit (a) containing 60 to 100 mol% of terephthalic acid units and 60 to 100 mol% of an aliphatic alkylenediamine unit having 6 to 18 carbon atoms And 0.1 to 120 parts by weight of an inorganic filler (B) having an average particle diameter of 2 m or less, based on 100 parts by weight of the polyamide (A) comprising the diamine unit (b). The polyamide composition of the present invention is excellent in heat resistance at the time of moisture absorption, dimensional stability, and surface smoothness, and is a material suitable for an LED reflector.

Japanese Patent Application Laid-Open No. 2002-294070 (Patent Document 2) discloses that 30 to 95% by weight of a semi-aromatic polyamide having a proportion of an aromatic monomer in an entire monomer component of 20% by mole or more and potassium titanate fiber and / or wollastonite 5 To 70% by weight of the resin composition for a reflector. The resin composition for a reflector shows good physical properties such as reflectance, whiteness and mechanical strength while showing useful properties of a polyamide resin.

However, in the polyamide resin disclosed in Patent Document 1, heat discoloration resistance (color discoloration resistance under heating conditions) of the material itself for maintaining the brightness may be lowered under high temperature conditions due to high brightness and high output of the LED. In addition, the resin composition described in Patent Document 2 may also cause a decrease in reflectance and a decrease in luminance due to discoloration of the resin itself under high temperature conditions.

Therefore, it is necessary to develop a polyamide resin excellent in heat discoloration resistance.

An object of the present invention is to provide a polyamide resin excellent in heat discoloration resistance and a method for producing the same.

The above and other objects of the present invention can be achieved by the present invention described below.

One aspect of the invention relates to polyamide resins. The polyamide resin is a polyamide resin obtained by a polycondensation reaction of a dicarboxylic acid compound and a diamine compound, wherein the concentration (unit: 占 퐉 ol / g) of the phosphorus compound contained in the polyamide resin and And the ratio of terminal amino group concentration (unit: 占 퐉 ol / g) (concentration of phosphorus compound / terminal amino group concentration) is 0.5 to 1.0.

In an embodiment, the dicarboxylic acid compound comprises 30 to 100 mole% of terephthalic acid and 0 to 70 mole% of dicarboxylic acid other than terephthalic acid, and the diamine compound is an aliphatic alkylenediamine having 50 to 100 And 0 to 50 mol% of diamines other than aliphatic alkylenediamines having 4 to 25 carbon atoms.

In an embodiment, the phosphorus compound may include at least one of hypophosphite, phosphite, phosphate, hypophosphorous acid, phosphorous acid and phosphoric acid.

In an embodiment, the polyamide resin has a terminal amino group concentration (NH ₂ ) of 20 to 100 μmol / g, a terminal carboxyl group concentration ([COOH]) of 20 to 250 μmol / g, a concentration of 0.5 g / dl And the logarithmic viscosity (IV) measured at a temperature of 25 ° C may be 0.6 to 1.5 dl / g.

In an embodiment, the concentration of the phosphorus compound may be between 10 and 100 μmol / g.

Another aspect of the present invention relates to a method for producing the polyamide resin. The preparation method comprises performing a polycondensation reaction between a dicarboxylic acid compound and a diamine compound in the presence of a phosphorus compound to prepare a lower condensation product; Discharging and cooling the lower condensate; And subjecting the cooled lower condensate to solid phase polymerization.

In a specific example, the ratio of the concentration (unit: 占 퐉 ol / g) of the phosphorus compound contained in the polyamide resin to the terminal amino group concentration (unit: 占 퐉 ol / g) of the polyamide resin ) May be 0.5 to 1.0.

The present invention has the effect of providing a polyamide resin excellent in heat discoloration resistance and a method for producing the same.

Hereinafter, the present invention will be described in detail.

The polyamide resin according to the present invention is a polyamide resin obtained by a polycondensation reaction of a dicarboxylic acid compound and a diamine compound, wherein the concentration (unit: 占 퐉 ol / g) of the phosphorus compound contained in the polyamide resin, (Concentration of phosphorus compound / terminal amino group concentration) of the terminal amino group concentration (unit: 占 퐉 ol / g) of the amide resin is 0.5 to 1.0. The polyamide resin having such a constitution is excellent in heat discoloration resistance (discoloration resistance under heating conditions).

[Dicarboxylic acid compound]

The dicarboxylic acid compound used in the present invention is not particularly limited, but may contain 30 to 100 mol% of terephthalic acid and 0 to 70 mol% of dicarboxylic acid other than terephthalic acid. It is possible to obtain a polyamide resin excellent in heat discoloration resistance in the above range. The total amount of the terephthalic acid and the dicarboxylic acid other than terephthalic acid is 100 mol%.

The content of terephthalic acid in the dicarboxylic acid compound may be 30 to 100 mol%, for example, 40 to 100 mol%, specifically 50 to 100 mol%. A polyamide resin excellent in heat discoloration resistance can be obtained in the terephthalic acid content range. If the content of the terephthalic acid is less than 30 mol%, the heat discoloration of the polyamide resin may be deteriorated.

Examples of the dicarboxylic acid other than terephthalic acid include malonic acid, dimethyl malonic acid, succinic acid, glutaric acid, adipic acid, 2-methyladipic acid, trimethyladipic acid, pimelic acid, 2,2-dimethylglutaric acid , Aliphatic dicarboxylic acids such as 3,3-diethyl succinic acid, suberic acid, azelaic acid, sebacic acid, undecane diacid and dodecane diacid; Cycloaliphatic dicarboxylic acids such as 1,3-cyclopentanedicarboxylic acid and 1,4-cyclohexanedicarboxylic acid; Isophthalic acid, 2,6-naphthalene dicarboxylic acid, 2,7-naphthalene dicarboxylic acid, 1,4-naphthalene dicarboxylic acid, 1,4-phenylenedioxydiacetic acid, 1,3- Dodecanoic acid, 4,4'-oxydibenzoic acid, diphenylmethane-4,4'-dicarboxylic acid, diphenylsulfone-4,4'-dicarboxylic acid, 4,4'-biphenyl And aromatic dicarboxylic acids such as dicarboxylic acid, but are not limited thereto. The dicarboxylic acid other than terephthalic acid may be used singly or in combination of two or more. For example, 1,4-cyclohexanedicarboxylic acid, isophthalic acid and the like can be used.

The content of the dicarboxylic acid other than terephthalic acid in the dicarboxylic acid compound may be 0 to 70 mol%, for example, 0 to 60 mol%, specifically 0 to 50 mol%.

If necessary, the dicarboxylic acid compound may be used in combination with a small amount of polyvalent carboxylic acid components such as trimellitic acid, trimesic acid, and pyromellitic acid.

[Diamine compound]

The diamine compound used in the present invention is not particularly limited, but may include 50 to 100 mol% of an aliphatic alkylene diamine having 4 to 25 carbon atoms and 0 to 50 mol% of a diamine other than an aliphatic alkylenediamine having 4 to 25 carbon atoms have. It is possible to obtain a polyamide resin excellent in heat discoloration resistance in the above range. The total amount of the aliphatic alkylenediamine having 4 to 25 carbon atoms and the diamine other than the aliphatic alkylenediamine having 4 to 25 carbon atoms is 100 mol%.

The content of the aliphatic alkylenediamine having 4 to 25 carbon atoms in the diamine compound may be 50 to 100 mol%, for example, 60 to 100 mol%, specifically 70 to 100 mol%.

Examples of the aliphatic alkylenediamine having 4 to 25 carbon atoms include 1,4-butanediamine, 1,6-hexanediamine (hexamethylenediamine), 1,7-heptanediamine, 1,8-octanediamine, 1,2-dodecanediamine, 2-methyl-1,5-pentanediamine, 3-methyl-1,5-pentanediamine, 1,12-dodecanediamine, 1,6-hexanediamine, 2,4-trimethyl-1,6-hexanediamine, 2-methyl-1,8-octanediamine, Can be exemplified. These may be used alone or in combination of two or more.

Examples of the diamines other than the aliphatic alkylenediamines having 4 to 25 carbon atoms include aliphatic diamines having 3 or less carbon atoms such as ethylenediamine and propanediamine; (4-aminocyclohexyl) methane, 1,3-bisaminomethylcyclohexane, 1,4-bisaminomethylcyclohexane, norbornanedimethanamine, trioctanedimethanamine, Alicyclic diamines such as cyclodecane dimethamine; aromatic diamines such as p-phenylenediamine, m-phenylenediamine, xylylenediamine, 4,4'-diaminodiphenylsulfone, and 4,4'-diaminodiphenyl ether. These may be used alone or in combination of two or more. Specifically, bis (4-aminocyclohexyl) methane, xylylenediamine and the like can be used. Here, the "xylylenediamine" includes three isomers of o-xylylenediamine, m-xylylenediamine (MXDA) and p-xylylenediamine (PXDA).

The content of the diamine other than the aliphatic alkylenediamine having 4 to 25 carbon atoms in the diamine compound may be 0 to 50 mol%, for example, 0 to 40 mol%, specifically 0 to 30 mol%.

The polyamide resin of the present invention has a ratio of the concentration (unit: μmol / g) of the phosphorus compound contained in the polyamide resin to the concentration (unit: μmol / g) of the terminal amino group of the polyamide resin Amino group concentration) may be 0.5 to 1.0, for example, 0.5 to 0.9. When the concentration of the phosphorus compound / terminal amino group concentration is less than 0.5, there is a possibility that the heat discoloration of the polyamide resin is lowered. When the concentration is more than 1.0, there is a fear of gas generation and gelation phenomenon accompanying side reactions during melt processing have.

The concentration / terminal amino group concentration of the phosphorus compound can be controlled by controlling the injection amount of the phosphorus compound or controlling the injection ratio of the dicarboxylic acid compound and the diamine compound as raw materials of the polyamide resin or the polymerization degree of the polyamide resin . For example, by increasing the injection rate of the dicarboxylic acid compound with respect to the diamine compound, the terminal amino group concentration can be relatively lowered. Further, by increasing the degree of polymerization of the polyamide resin, both the terminal amino group concentration and the terminal carboxyl group concentration can be lowered. In the present invention, the injection ratio of the dicarboxylic acid compound and the diamine compound, the degree of polymerization of the polyamide resin, and the like are not particularly limited as long as the concentration of the phosphorus compound / the terminal amino group concentration is within a predetermined range. For example, it is possible to determine the injection ratio of the dicarboxylic acid compound or the diamine compound, depending on the amount of the phosphorous compound to be added, after the degree of polymerization of the polyamide resin is set according to the intended use.

Examples of the phosphorus compound contained in the polyamide resin of the present invention include hypophosphorous acid, phosphite, phosphate, hypophosphorous acid, phosphorous acid, phosphoric acid, phosphoric acid ester, polymethic acid, polyphosphoric acid, phosphinoxide, But the present invention is not limited thereto. These can be used as catalysts in the production of the lower condensates described below. From the viewpoint of heat discoloration resistance, it is preferable to use at least one of hypophosphite, phosphite, phosphate, hypophosphorous acid, phosphorous acid and phosphoric acid, more preferably at least one of hypophosphite, phosphate, hypophosphorous acid and phosphoric acid Can be used.

Examples of the hypophosphite include sodium hypophosphite, potassium hypophosphite, calcium hypophosphite, magnesium hypophosphite, aluminum hypophosphite, vanadium hypophosphite, manganese hypophosphite, zinc hypophosphite, lead hypophosphite, nickel hypophosphite, cobalt hypophosphite Ammonium phosphite, and the like.

Examples of the phosphite include potassium phosphite, sodium phosphite, calcium phosphite, magnesium phosphite, manganous phosphite, nickel phosphite, cobalt phosphite, and the like.

Examples of the phosphate include sodium phosphate, potassium phosphate, potassium dihydrogenphosphate, calcium phosphate, vanadium phosphate, magnesium phosphate, manganese phosphate, lead phosphate, nickel phosphate, cobalt phosphate, ammonium phosphate and ammonium dihydrogenphosphate.

Examples of the phosphate ester include monomethyl phosphate, dimethyl phosphate, trimethyl phosphate, monoethyl phosphate, diethyl phosphate, triethyl phosphate, propyl phosphate, dipropyl phosphate, tripropyl phosphate, isopropyl phosphate, di Isopropyl phosphate, isopropyl phosphate, triisopropyl phosphate, butyl phosphate, dibutyl phosphate, tributyl phosphate, isobutyl phosphate, diisobutyl phosphate, triisobutyl phosphate, hexyl phosphate, dihexyl phosphate, trihexyl (2-ethylhexyl) phosphate ester, tri (2-ethylhexyl) phosphate decyl phosphate, didecyl phosphate ester, dodecyl phosphate ester, Tridecyl phosphate, isodecyl phosphate, diisodecyl phosphate, triisodecyl phosphate , And the like can be given as stearyl phosphate, distearyl phosphate, tristearate aryl phosphate, monophenyl phosphate, diphenyl phosphate, triphenyl phosphate, ethyl phosphate, octadecyl.

Examples of the polymetaphosphoric acid include sodium trimetaphosphate, sodium pentametaphosphate, sodium hexametaphosphate and polymetaphosphoric acid. Examples of the polyphosphoric acid include sodium tetrapolyphosphate and the like. Examples of the phosphine oxides include hexamethylphosphoramide and the like.

These phosphorus compounds may be in the form of hydrates. Among these phosphorus compounds, sodium hypophosphite or its hydrate, sodium phosphite or its hydrate is preferable. These phosphorus compounds may be used singly or in combination of two or more.

The concentration of the phosphorus compound contained in the polyamide resin of the present invention may be 10 to 100 占 퐉 ol / g, for example, 30 to 70 占 퐉 ol / g. A polyamide resin excellent in heat discoloration resistance can be obtained without side reaction such as gelation in the above range. The concentration of the phosphorus compound can be measured using an inductively coupled plasma atomic emission spectrometer (ICP-AES). More specifically, the concentration can be measured according to the method described in the Examples.

In order to add (inject) the phosphorus compound to the polyamide resin, as described above, the low-order condensate may be added together with the raw material during the production, or the low-order condensate may be dispersed by impregnating a solution of the phosphorus compound Solid phase polymerization or the like may be carried out thereafter, but it is not limited thereto. In order to obtain the effect of heat discoloration, it is more preferable to add it in the production of the lower condensate.

The terminal amino group concentration ([NH ₂ ]) of the polyamide resin of the present invention may be 20 to 100 μmol / g, for example, 30 to 80 μmol / g. Within the above range, the heat resistant discoloration of the polyamide resin may be excellent. The terminal amino group concentration can be measured by a titration method. More specifically, the terminal amino group concentration can be measured by the method described in the examples.

The terminal carboxyl group concentration ([COOH]) of the polyamide resin of the present invention may be 20 to 250 μmol / g, for example, 30 to 200 μmol / g. Within the above range, a polyamide resin having excellent heat discoloration resistance of the polyamide resin and having a sufficient degree of polymerization capable of producing a molding material can be obtained. The terminal carboxyl group concentration can be measured using a titration method, and more specifically, can be measured according to the method described in the examples.

In embodiments, the polyamide resin of the present invention has an logarithmic viscosity (IV) of 0.6 to 1.5 dl / g, such as 0.7 to 1.3 dl / g, measured at a concentration of 0.5 g / dl in concentrated sulfuric acid and at 25 ≪ / RTI > The heat resistance of the polyamide resin in the above range can be excellent. Specifically, the IV can be measured according to the method described in the following examples.

The melting point of the polyamide resin may be 280 占 폚 or higher, for example, 290 占 폚 or higher. The crystallization temperature of the polyamide resin may be 250 ° C or higher, for example, 260 ° C or higher. Specifically, the melting point and the crystallization temperature can be measured according to the methods described in the following examples.

The polyamide resin of the present invention is not particularly limited but includes a step of carrying out a polycondensation reaction of the dicarboxylic acid compound and the diamine compound in the presence of a phosphorus compound to produce a lower condensate; A step of discharging and cooling the lower condensate; And a step of solid-phase-polymerizing the cooled lower-order condensate. According to the above production method, it is possible to prevent or reduce manufacturing problems such as gel generation during production, and to obtain a polyamide resin excellent in heat discoloration resistance.

Hereinafter, the manufacturing method will be described in detail for each step, but the present invention is not limited thereto.

≪ Process for producing a low-condensation product &

In this step, a polycondensation reaction of a dicarboxylic acid compound and a diamine compound is carried out to produce a lower condensation product of a polyamide resin.

The lower-order condensate can be synthesized by, for example, introducing an aqueous solution or the like of the monomer or salt into a commonly used pressure polymerization reactor and performing a polycondensation reaction in an aqueous solvent under stirring conditions.

Here, the aqueous solvent is a solvent containing water as a main component. The solvent that can be used in addition to water is not particularly limited as long as it does not affect the polycondensation reactivity or solubility, and for example, alcohols such as methanol, ethanol, propanol, butanol and ethylene glycol can be used.

The water content in the reaction system at the time of initiating the polycondensation reaction may be such that the water content in the reaction system at the completion of the reaction is 15 to 35% by weight. In embodiments, the amount of water in the reaction system when initiating the polycondensation reaction may be from 17 to 60% by weight. In the range of the amount of water in the reaction system at the time of initiating the polycondensation reaction, the solution becomes a substantially homogeneous solution form at the start of the polycondensation reaction, and an excessive time and energy are required for distilling off the water in the polycondensation step And the thermal deterioration of the low-order condensate due to the extension of the reaction time can be reduced.

In the specific examples, a phosphorus-based catalyst (phosphorus compound) can be used for the purpose of improving the polycondensation rate and preventing deterioration during the polycondensation reaction in the production of the lower condensate. As the phosphorus-based catalyst, there may be used hypophosphite, phosphite, phosphate, hypophosphorous acid, phosphorous acid, phosphoric acid, phosphoric acid ester, polymetalic acid, polyphosphoric acid, phosphinoxide, phosphonium halide and mixtures thereof . For example, hypophosphite, phosphite, phosphate, hypophosphorous acid, phosphorous acid, phosphoric acid, and mixtures thereof can be used. Specifically, hypophosphite, phosphate, hypophosphorous acid, phosphoric acid and mixtures thereof can be used. Specific examples of these phosphorus-containing catalysts are the same as the specific examples of the phosphorus compounds described above, and the description thereof is omitted here.

The addition amount of the phosphorus catalyst may be 0.1 to 1.0 parts by weight, for example, 0.2 to 0.5 parts by weight, based on 100 parts by weight of the total amount of the monomers (dicarboxylic acid compound and diamine compound). The addition timing may be any time up to the completion of the solid phase polymerization, but it is preferably between the injection of the raw material and the completion of the polycondensation of the lower condensate. The catalyst may be added at least once, or two or more different phosphorus-containing catalysts may be added in combination.

Further, the above-mentioned polycondensation reaction can be carried out in the presence of an end-capping agent. When the end sealant is used, the molecular weight of the lower condensation product can be more easily controlled and the melt stability of the lower condensation product can be improved. The terminal endblocking agent is not particularly limited as long as it is a monofunctional compound having reactivity with the terminal amino group or terminal carboxyl group of the lower condensate. For example, an acid anhydride such as monocarboxylic acid, monoamine, phthalic anhydride, Mono-acid halides, monoesters, mono-alcohols and the like can be used. The end-cap encapsulant may be used alone or in combination of two or more. Among the above-mentioned terminal sealing agents, a monocarboxylic acid or a monoamine is preferably used as a terminal endblocker from the viewpoints of reactivity and stability of a sealing end, and monocarboxylic acid can be more preferably used because it is easy to handle.

The monocarboxylic acid is not particularly limited as long as it is a monocarboxylic acid having reactivity with an amino group. Examples of the monocarboxylic acid include acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, capric acid, lauric acid, tridecylic acid, Aliphatic monocarboxylic acids such as myristic acid, palmitic acid, stearic acid, pivalic acid, and isobutyric acid; Alicyclic monocarboxylic acids such as cyclohexanecarboxylic acid; Aromatic monocarboxylic acids such as benzoic acid, toluic acid,? -Naphthalenecarboxylic acid,? -Naphthalenecarboxylic acid, methylnaphthalenecarboxylic acid, and phenylacetic acid; A mixture thereof, and the like. Among them, acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, capric acid, lauric acid, tridecylic acid, myristic acid, palmitic acid, stearic acid Acid, benzoic acid, and the like are preferable.

The monoamine is not particularly limited as long as it is a monoamine having reactivity with a carboxyl group. Examples of the monoamine include methylamine, ethylamine, propylamine, butylamine, hexylamine, octylamine, decylamine, stearylamine, dimethylamine , Aliphatic monoamines such as diethylamine, dipropylamine and dibutylamine; Alicyclic monoamines such as cyclohexylamine and dicyclohexylamine; Aromatic monoamines such as aniline, toluidine, diphenylamine and naphthylamine; A mixture thereof, and the like. Of these, butylamine, hexylamine, octylamine, decylamine, stearylamine, cyclohexylamine and aniline are preferable in view of reactivity, boiling point, stability of the sealing end, and price.

The amount of the endcapping agent used in the production of the lower condensate may vary depending on the reactivity of the endcapping agent to be used, the boiling point, the reaction apparatus, the reaction conditions, and the like. For example, for 100 molar parts of the dicarboxylic acid or diamine, 0.1 to 15 molar parts.

The synthesis of the lower condensate can be carried out under normal stirring conditions by raising the temperature and increasing the pressure. Here, the polymerization temperature can be controlled after the injection of the raw material, and the polymerization pressure can be controlled in accordance with the progress of the polymerization.

In this process, the reaction temperature may be 230 to 260 ° C, for example, 240 to 250 ° C. Within the above range, the lower condensate can be efficiently obtained without any side reaction such as gelation. Further, the reaction pressure may be 0.5 to 5 MPa, for example, 1.0 to 4.5 MPa. Within the above range, the temperature in the reaction system and the amount of water in the reaction system can be easily controlled, and the lower condensation product can be easily discharged. Further, since a reaction device having a low pressure resistance can be used, it is economically advantageous and the degree of polymerization of the lower condensate can be increased by gradually changing the water content in the reaction system. The reaction time may be 0.5 to 4 hours, for example, 1 to 3 hours. Here, the reaction time means the time required from the reaction temperature of the present invention to the start of the discharge operation. Within the above range, a sufficient reaction rate is attained, and unreacted materials hardly remain, and a low-order condensate of uniform properties can be obtained. Further, a high-quality low-order condensate can be obtained without giving an excessive heat history.

In the above step, the water content in the reaction system at the completion of the reaction of the lower condensate may be 15 to 35% by weight, for example, 20 to 35% by weight. Here, the term "reaction completion" refers to a time point at which the discharge operation of the lower condensate having reached the predetermined degree of polymerization is started, and the water content is the sum of the condensed water amount generated during the reaction. In order to adjust the water content to the above range, a water amount combined with the generated condensation water may be injected, or a predetermined amount of water may be distilled off by adjusting the reaction pressure in an apparatus equipped with a condenser, a pressure regulating valve or the like. Precipitation or solidification of the lower condensate in the reaction system hardly takes place in the range of the above amount of water, and the lower condensate can be easily discharged. Further, since the lower condensate having a sufficient degree of polymerization can be easily obtained and the amount of moisture to be evaporated and separated at the time of discharge is small, the discharge rate can be increased and the production efficiency can be improved.

In addition, a salt controlling step and / or a condensing step may be added, if necessary, before the polymerization of the lower condensate. The salt controlling step may be a step of producing a salt from a dicarboxylic acid component and a diamine component and adjusting the pH to a range of the pH of the neutralization point of the salt, for example, a pH of the neutralization point of the salt of +/- 0.3. In the concentration step, the concentration of the raw material injection concentration may be increased to a concentration of +2 to +90 wt%, for example, +5 to +80 wt%. The concentration step may be carried out at a temperature of 90 to 220 DEG C, for example 100 to 210 DEG C, specifically 130 to 200 DEG C and a pressure of 0.1 to 2.0 MPa. Normally, the concentration pressure can be controlled below the polymerization pressure. Further, for accelerating the concentration, for example, a forced discharge operation may be performed using a nitrogen stream or the like. The concentration process is effective for shortening the polymerization time.

In this process, the lower condensation product (after cooling) after being discharged from the reaction vessel has a logarithmic viscosity (IV) of 0.07 to 0.40 dl / g, as measured at a concentration of 0.5 g / dl in concentrated sulfuric acid and a temperature of 25 ° C, 0.10 to 0.25 dl / g. In the IV range, it is possible to inhibit adhesion of the resin powders to each other in the solid-state polymerization due to the presence of a low-melting point and adhesion to the inside of the apparatus, and suppress precipitation and fixation in the reaction system during production of the low- .

In this process, the polycondensation reaction for obtaining the lower condensate can be carried out batchwise or continuously. Further, in order to prevent adhesion of the lower condensate to the reaction vessel and uniform progress of the polycondensation reaction, the polycondensation reaction is preferably carried out under stirring.

≪ Process of discharging and cooling low-order condensates >

Next, in this step, the produced lower condensate is discharged and cooled from the reaction vessel. When the temperature of the reaction system is in the range of 230 to 260 ° C and the amount of water in the reaction system at the completion of the reaction is in the range of 15 to 35% by weight, the lower condensate is discharged (taken) (Withdrawing) the condensate from the reaction vessel under an inert gas atmosphere at a pressure of atmospheric pressure or lower. This discharging method does not require the use of a pressure vessel for taking out controlled at a predetermined pressure, and it is unnecessary to take out the low-order condensate from the reaction vessel while separately supplying water vapor into the reaction vessel, so that thermal deterioration is small and the logarithmic viscosity is sufficiently high (Powdery or granular form) having a high bulk specific gravity can be obtained simply and efficiently.

It is preferable that the inert gas atmosphere has an oxygen concentration of 1% by volume or less in order to prevent oxidation deterioration of the low-order condensate.

In an embodiment, the discharge speed of the lower condensate from the reaction vessel can be appropriately controlled in accordance with the scale of the reaction vessel, the amount of the contents in the reaction vessel, the temperature, the size of the outlet, and the length of the extraction nozzle. Normally, it can be taken out so that the discharge rate per outlet cross-sectional area is in the range of 2,000 to 20,000 kg / s / m ² . Within the above-mentioned range, it is possible to prevent or reduce the collapse of the lower condensation product, coagulation, fusing to the reactor wall, etc. during the solid phase polymerization, The volume efficiency can be improved.

In the specific example, the low-order condensate taken out from the reaction vessel is rapidly lowered to, for example, 100 ° C or less due to the latent heat of evaporation of water at the time of acquisition, so that thermal deterioration and oxygen deterioration hardly occur. In addition, since the discharged lower condensate evaporates most of the accompanying water by sensible heat possessed by the lower condensate, the lower condensate is cooled and dried at the same time in this step. The efficiency of drying and cooling can be improved when the discharge of the adhesion condensate is carried out under an inert gas condition such as nitrogen or under a pressure lower than atmospheric pressure. In addition, when a cyclone-type solid-gas separation device is provided as a discharge vessel, it is possible to suppress out-of-scale scattering of powder at the time of discharge, to perform discharge treatment at a high gas flux rate, .

Since the low-order condensate discharged and cooled in this way has a sufficiently high logarithm viscosity as described above and a low residual amount of unreacted materials, it is possible to prevent the occurrence of fusion or agglomeration of particles of the low-order condensate Solid phase polymerization can be carried out at a high temperature, and deterioration due to side reaction is small.

In addition, the above process may further perform a compacting process or a granulating process to match the particle diameters, if necessary.

<Solid State Polymerization>

In this step, the polyamide resin is produced by subjecting the lower condensate discharged and cooled from the reaction vessel to high polymerization by solid state polymerization. The solid phase polymerization can be carried out after the low-order condensate is taken out of the reaction vessel and used as it is or after drying. Alternatively, the solid phase polymerization may be carried out after the low-order condensate taken out from the reaction vessel has been once stored or subjected to the compacting treatment or the granulation treatment And may be carried out after execution. When the above-mentioned adhesion promoter is made highly polymerized through solid-state polymerization, a polyamide having less thermal deterioration can be obtained.

The polymerization method and conditions for the solid phase polymerization of the low-order condensate are not particularly limited, and a method and conditions capable of achieving high polymerization while maintaining the solid state without causing fusion, aggregation, deterioration, . However, in order to prevent oxidation deterioration of the lower condensate and the polyamide resin to be produced, it is preferable to carry out the solid phase polymerization in an inert gas atmosphere such as helium gas, argon gas, nitrogen gas or carbon dioxide gas or under reduced pressure. In the solid state polymerization, the reaction temperature is not particularly limited, but may be 200 to 250 ° C, for example, 210 to 240 ° C. The reaction time in the solid phase polymerization is not particularly limited, and may be generally from 1 hour to 20 hours. During the solid phase polymerization reaction, the lower condensate may be mechanically stirred or stirred using a gas stream.

As a solid phase polymerization apparatus used in the present step, a conventional solid phase polymerization apparatus can be used without limitation. Specific examples of the solid-state polymerization apparatus include, for example, a single-shaft disk type, a kneader, a two-axis paddle type, a vertical type column type apparatus, a vertical type column type apparatus, a rotary drum type or a double cone type solid- But is not limited thereto.

In the method for producing a polyamide resin of the present invention, various fiber materials such as glass fibers and carbon fibers, inorganic fibers such as inorganic fibers An additive such as a filler, a filler in the form of an organic powder, a colorant, an ultraviolet absorber, a light stabilizer, an antioxidant, an antistatic agent, a flame retardant, a crystallization accelerator, a plasticizer and a lubricant may be added.

The polyamide resin production method of the present invention can produce a polyamide resin which hardly causes problems in production such as gelation and is excellent in heat discoloration resistance.

The polyamide resin of the present invention is excellent in heat discoloration resistance. Therefore, by taking advantage of these characteristics, the polyamide resin alone or in the form of a composition with the various additives and other polymers as necessary can be used for various conventional molding methods and spinning methods conventionally used for polyamide resins such as injection molding, blow molding it can be molded into various molded articles or fibers using a molding method such as blow molding, extrusion molding, compression molding, drawing, vacuum molding, or melt spinning. Such molded products and fibers are useful for various uses such as industrial plastic materials such as electric and electronic parts, automobile parts, and office parts, industrial materials, home appliances and the like as well as engineering plastics. Particularly, it is possible to provide a light emitting diode (LED) light emitting device, various electric and electronic parts, a remote headset system of a car, a backlight of a refrigerator, a backlight of a liquid crystal display, Optical communication devices, ceiling light devices, and the like.

Hereinafter, the configuration and operation of the present invention will be described in more detail with reference to preferred embodiments of the present invention. It is to be understood, however, that the same is by way of illustration and example only and is not to be construed in a limiting sense.

Example

Example 1: Preparation of polyamide resin

As the raw material, 179.72 g (1.082 mole) of terephthalic acid, 170.28 g (0.988 mole = 90 mole%) of 1,10-diaminodecane, 22.00 g (0.110 mole = 10 mole%) of 1,12- diaminododecane, 1.504 g (14.19 mmol, 0.4 part by weight based on 100 parts by weight of the starting material for injection) and 251 g (40 parts by weight with respect to 100 parts by weight of the starting material) of sodium hypophosphite monohydrate (SHM) The autoclave was poured into a 1 liter autoclave reaction vessel equipped with a condenser, a pressure adjusting valve, and a bottom discharge valve, and nitrogen replacement was carried out. The temperature was raised to 180 캜 over 1 hour while stirring, and the temperature was maintained for 0.5 hours. Thereafter, the internal temperature was raised to 250 DEG C over 1 hour and maintained. After the internal pressure of the reaction tank reached 3.5 MPa, the reaction was continued for 2.5 hours while distilling off the water to maintain the same pressure.

After the lapse of a predetermined reaction time, the resulting low condensation condensate was passed through a bottom discharge valve, under nitrogen flow, at room temperature (25 占 폚) under atmospheric pressure, while maintaining the temperature of the reaction vessel and the water content And discharged into a receiver to obtain a white, powder-like lower condensate.

300 g of the resulting lower condensate was placed in a 1,000 ml round bottom flask and placed in a rotary evaporator equipped with an oil bath. After the flask was purged with nitrogen, the flask was immersed in an oil bath while rotating the flask under nitrogen flow at 1 l / After raising the temperature to 230 캜 over 1 hour, the solid state polymerization was continued at the same temperature for 5 hours. After a predetermined reaction time had elapsed, the reaction mixture was cooled to room temperature (25 DEG C) to obtain a polyamide resin having a high polymerization degree.

The IV of the obtained polyamide resin was 0.85 dl / g, the melting point by DSC measurement was 309 占 폚, and the crystallization temperature was 280 占 폚. The hue was L ^* = 100.3 and YI = 5.7, and a polyamide resin having a sufficiently high polymerization degree and a good color was obtained. The molar ratio of the phosphorus compound to the terminal amino group in the obtained polyamide resin was 38 μmol / g, the terminal amino group concentration [NH ₂ ] was 75 μmol / g and the terminal carboxyl group concentration [COOH] was 63 μmol / 0.50. The color of the sample after heat treatment at 170 ° C for 8 hours in a heating oven was L ^* = 97.1 and YI = 13.7, and the lightness and yellowness of the sample were good. Molded specimens were produced by injection molding using the obtained polyamide resin and visually evaluated for appearance. As a result, silver streaks (silver streaks) due to indentation due to poor charging, moisture, and gas generation, It was confirmed that there is no color or yellow color such as yellowing. That is, a molding specimen of a polyamide resin having good appearance and color was obtained.

Example 2: Preparation of polyamide resin

A polyamide resin having a high polymerization degree was obtained in the same manner as in Example 1 except that the temperature for the solid phase polymerization was changed to 240 캜.

The IV of the obtained polyamide resin was 1.11 dl / g, the melting point by DSC measurement was 309 占 폚, and the crystallization temperature was 279 占 폚. The hue was L ^* = 100.1 and YI = 4.9, and a polyamide resin with good coloring and high polymerization degree was obtained. The molar ratio of the phosphorus compound to the terminal amino group in the obtained polyamide resin was 37 μmol / g, the terminal amino group concentration [NH ₂ ] was 54 μmol / g and the terminal carboxyl group concentration [COOH] was 29 μmol / 0.70. The samples were heat-treated in a heating oven at 170 占 폚 for 8 hours, and the hue and lightness of the sample were good. L ^* = 97.1 and YI = 14.1. The molded polyamide resin was used for injection molding to produce molded specimens. Silver streaks (silver streaks) due to insufficient filling, moisture, gas, etc., Molding specimens of a polyamide resin having good appearance and color were obtained without any coloration such as yellowing.

Example 3: Preparation of polyamide resin

The injection amount of the raw material was changed to 180.64 g (1.087 mole) of terephthalic acid, 169.46 g (0.983 mole = 90 mole%) of 1,10-diaminodecane, 21.89 g (0.109 mole = 10 mole%) of 1,12- Benzoic acid was changed to 3.98 g (0.033 mole), and the solid-state polymerization temperature was changed to 240 占 폚, a polyamide resin having a high degree of polymerization was obtained in the same manner as in Example 1. [

The IV of the obtained polyamide resin was 0.95 dl / g, the melting point by DSC measurement was 310 占 폚, and the crystallization temperature was 282 占 폚. The hue was L ^* = 100.0 and YI = 5.2, and a polyamide resin having a sufficiently high polymerization degree and a good color was obtained. The molar ratio of the phosphorus compound to the terminal amino group in the obtained polyamide resin was 38 μmol / g, the terminal amino group concentration [NH ₂ ] was 38 μmol / g and the terminal carboxyl group concentration [COOH] was 68 μmol / 0.99. L ^* = 97.3, YI = 14.5, and the lightness and yellowness of the sample were good after heating treatment at 170 DEG C for 8 hours in a heating oven. The molded polyamide resin was used for injection molding to produce molded specimens. Silver streaks (silver streaks) due to insufficient filling, moisture, gas, etc., Molding specimens of a polyamide resin having good appearance and color without any mixing and no color hue such as yellowing were obtained.

Example 4: Preparation of polyamide resin

The injection amount of the starting material was changed to 168.17 g (1.012 mol) of terephthalic acid, 203.83 g (1.017 mol) of 1,12-diaminododecane, 3.71 g (0.030 mol) of benzoic acid and 0.744 g (7.02 mmol, 0.2 part by weight with respect to 100 parts by weight of the raw material for injection), the internal temperature at the time of producing the low-order condensate was controlled at 240 占 폚, the internal pressure at 2.4 MPa, and the solid-state polymerization temperature was 220 占 폚. In the same manner, a polyamide resin with high polymerization degree was obtained.

The IV of the obtained polyamide resin was 0.92 dl / g, the melting point by the DSC measurement was 297 占 폚, and the crystallization temperature was 267 占 폚. The color was L ^* = 99.7, YI = 2.5, and a polyamide resin having a sufficiently high polymerization degree and a good color was obtained. In addition, the compound of a concentration of the polyamide resin obtained 19 μmol / g, the terminal amino group concentration [NH _2] was 37 μmol / g, terminal carboxyl group concentration [COOH] is 79 μmol / g, the compound and the molar ratio of the terminal amino group is 0.51. L ^* = 98.6, YI = 11.4, and the lightness and yellowness of the sample were good after heating treatment at 170 DEG C for 8 hours in a heating oven. The molded polyamide resin was used for injection molding to produce molded specimens. Silver streaks (silver streaks) due to insufficient filling, moisture, gas, etc., Molding specimens of a polyamide resin having good appearance and color without any mixing and no color hue such as yellowing were obtained.

Example 5: Preparation of polyamide resin

The injected amount of the raw material was changed to 1.488 g (14.04 mmol, 0.15 mol) of terephthalic acid (167.26 g, 1.007 mol), 1,12-diaminododecane (204.74 g, 1.022 mol), benzoic acid (3.30 g, 0.030 mol), sodium hypophosphite monohydrate And 0.4 parts by weight with respect to 100 parts by weight of the raw material for injection), a polyamide resin having a high degree of polymerization was obtained in the same manner as in Example 4. [

The obtained polyamide resin had an IV of 0.97 dl / g, a melting point of 299 캜 according to DSC measurement, and a crystallization temperature of 268 캜. The color was L ^* = 100.3 and YI = 3.3, and a polyamide resin having a sufficiently high polymerization degree and a good color was obtained. The molar ratio of the phosphorus compound to the terminal amino group in the obtained polyamide resin was 38 μmol / g, the terminal amino group concentration [NH ₂ ] was 52 μmol / g and the terminal carboxyl group concentration [COOH] was 52 μmol / 0.73. L ^* = 99.0, YI = 10.3, and the lightness and yellowness of the sample were good after heating treatment at 170 DEG C for 8 hours in a heating oven. The molded polyamide resin was used for injection molding to produce molded specimens. Silver streaks (silver streaks) due to insufficient filling, moisture, gas, etc., Molding specimens of a polyamide resin having good appearance and color without any mixing and no color hue such as yellowing were obtained.

Example 6: Preparation of polyamide resin

1.488 g of sodium hypophosphite monohydrate (SHM) (14.04 mmol, 0.4 part by weight based on 100 parts by weight of the raw material for injection) was controlled to an internal temperature of 250 占 폚 and an internal pressure of 3.5 MPa during the production of the lower condensate, Was changed to 230 캜, a polyamide resin having a high polymerization degree was obtained in the same manner as in Example 4.

The IV of the obtained polyamide resin was 0.95 dl / g, the melting point by the DSC measurement was 297 占 폚, and the crystallization temperature was 269 占 폚. The hue was L ^* = 100.7 and YI = 3.6, and a polyamide resin having a sufficiently high polymerization degree and a good color was obtained. The molar ratio of the phosphorus compound to the terminal amino group in the obtained polyamide resin was 38 μmol / g, the terminal amino group concentration [NH ₂ ] was 39 μmol / g and the terminal carboxyl group concentration [COOH] was 76 μmol / 0.97. L ^* = 98.1, YI = 12.8, and the brightness and yellowness of the sample were good after heating treatment at 170 DEG C for 8 hours in a heating oven. The molded polyamide resin was used for injection molding to produce molded specimens. Silver streaks (silver streaks) due to insufficient filling, moisture, gas, etc., Molding specimens of a polyamide resin having good appearance and color without any mixing and no color hue such as yellowing were obtained.

Example 7: Preparation of polyamide resin

The injection amount of the raw material was changed to 182.42 g (1.098 mole) of terephthalic acid, 167.89 g (0.974 mole = 90 mole%) of 1,10-diaminodecane, 21.69 g (0.108 mole = 10 mole%) of 1,12- (0.033 mol) of benzoic acid and that the solid-state polymerization temperature was 240 캜, a polyamide resin having a high degree of polymerization was obtained in the same manner as in Example 1.

The IV of the obtained polyamide resin was 0.65 dl / g, the melting point by DSC measurement was 309 占 폚, and the crystallization temperature was 282 占 폚. The color was L ^* = 99.9, YI = 4.6, and a polyamide resin having a sufficiently high polymerization degree and a good color was obtained. The molar ratio of the phosphorus compound to the terminal amino group in the obtained polyamide resin was 38 μmol / g, the terminal amino group concentration [NH ₂ ] was 56 μmol / g and the terminal carboxyl group concentration [COOH] was 220 μmol / , 0.69. The color of the sample after heat treatment at 170 占 폚 for 8 hours in a heating oven was L ^* = 97.0 and YI = 16.5, and the lightness and yellowness of the sample were good. The molded polyamide resin was used for injection molding to produce molded specimens. Silver streaks (silver streaks) due to insufficient filling, moisture, gas, etc., Molding specimens of a polyamide resin having good appearance and color without any mixing and no color hue such as yellowing were obtained.

Example 8: Preparation of polyamide resin

The injection amount of the raw material was changed to 179.45 g (1.080 mol) of terephthalic acid, 170.52 g (0.990 mol = 90 mol%) of 1,10-diaminodecane and 22.03 g (0.110 mol = 10 mol%) of 1,12- Polyimide resin having a high degree of polymerization was obtained in the same manner as in Example 1 except that 3.96 g (0.032 mol) of benzoic acid was used and the solid-phase polymerization temperature was 240 DEG C and the reaction time was 6 hours.

The IV of the obtained polyamide was 1.40 dl / g, the melting point by DSC measurement was 309 占 폚, and the crystallization temperature was 279 占 폚. The color was L ^* = 99.6, YI = 6.5, and a polyamide resin having a sufficiently high polymerization degree and a good color was obtained. Further, a compound concentration of 37 μmol / g, the terminal amino group concentration [NH _2] was 52 μmol / g, terminal carboxyl group concentration [COOH] of 18 and μmol / g, the compound and the molar ratio of the terminal amino group of the polyamide resin thus obtained is , 0.71. L ^* = 96.8, YI = 17.5, and the lightness and yellowness of the sample were good after heating treatment at 170 DEG C for 8 hours in a heating oven. The molded polyamide resin was used for injection molding to produce molded specimens. Silver streaks (silver streaks) due to insufficient filling, moisture, gas, etc., Molding specimens of a polyamide resin having good appearance and color without any mixing and no color hue such as yellowing were obtained.

Comparative Example 1: Production of polyamide resin

The injection amount of the raw material was changed to 180.64 g (1.087 mole) of terephthalic acid, 169.46 g (0.983 mole = 90 mole%) of 1,10-diaminodecane, 21.89 g (0.109 mole = 10 mole%) of 1,12- (0.033 mole) of benzoic acid, and 0.376 g (3.55 mmol, based on 100 parts by weight of the starting material for injection) of 0.376 g of sodium hypophosphite monohydrate (SHM) were used as the starting materials. A polyamide resin was obtained.

The IV of the obtained polyamide resin was 1.02 dl / g, the melting point by DSC measurement was 309 占 폚, and the crystallization temperature was 280 占 폚. The hue was L ^* = 100.3 and YI = 5.5, and a polyamide resin having a sufficiently high polymerization degree and a good color was obtained. Further, the compound concentration in the polyamide resin thus obtained is 9 μmol / g, the terminal amino group concentration [NH _2] was 55 μmol / g, the terminal is 76 μmol / g a carboxyl group concentration [COOH], a molar ratio of the compound and the terminal amino group is 0.17. L ^* = 96.4, YI = 19.3, and the lightness and yellowness of the sample were inferior to those of the sample after heating treatment at 170 DEG C for 8 hours in a heating oven.

Comparative Example 2: Production of polyamide resin

The injection amount of the raw material was changed to 179.27 g (1.079 mole) of terephthalic acid, 170.68 g (0.991 mole = 90 mole%) of 1,10-diaminodecane, 22.05 g (0.110 mole = 10 mole%) of 1,12- (0.032 mol) of benzoic acid, 0.752 g (7.09 mmol, based on 100 parts by weight of the starting material for injection) of sodium hypophosphite monohydrate (SHM) was changed to 0.2 weight part. A polyamide resin was obtained.

The IV of the obtained polyamide resin was 1.04 dl / g, the melting point by DSC measurement was 309 占 폚, and the crystallization temperature was 281 占 폚. The hue was L ^* = 100.1 and YI = 5.6, and a polyamide resin having a sufficiently high polymerization degree and a good color was obtained. Further, a compound concentration of 18 μmol / g, the terminal amino group concentration [NH _2] was 80 μmol / g, terminal carboxyl group concentration [COOH] is a molar ratio of 53 is μmol / g, the compound and the terminal amino group of the polyamide resin thus obtained is 0.24. L ^* = 96.2, YI = 20.8, and the lightness and yellowness of the sample were inferior to those of the sample after heating treatment at 170 DEG C for 8 hours in a heating oven.

Comparative Example 3: Production of polyamide resin

The injection amount of the raw material was changed to 181.39 g (1.092 mole) of terephthalic acid, 168.80 g (0.980 mole = 90 mole%) of 1,10-diaminodecane, 21.81 g (0.109 mole = 10 mole%) of 1,12- Except that 0.336 g (3.55 mmol, based on 100 parts by weight of the starting material for injection) of 4.00 g (0.033 mole) of benzoic acid and sodium hypophosphite monohydrate (SHM) was used and the solid-state polymerization temperature was 245 DEG C. 1, a polyamide resin having a high polymerization degree was obtained.

The IV of the obtained polyamide resin was 0.86 dl / g, the melting point by DSC measurement was 310 占 폚, and the crystallization temperature was 282 占 폚. The color was L ^* = 99.1, YI = 6.4, and a polyamide resin with high polymerization degree was obtained. The resulting polyamide resin had a phosphorus compound concentration of 9 μmol / g, a terminal amino group concentration of [NH ₂ ] of 25 μmol / g and a terminal carboxyl group concentration of [COOH] of 82 μmol / g, 0.38. The color of the sample after the heat treatment at 170 占 폚 for 8 hours in a heating oven was L ^* = 94.9 and YI = 22.0, and the brightness and yellowness of the sample were inferior.

Comparative Example 4: Production of polyamide resin

A polyamide resin having a high degree of polymerization was obtained in the same manner as in Example 3 except that the solid-state polymerization time was changed to 7 hours.

The IV of the obtained polyamide resin was 1.12 dl / g, the melting point by DSC measurement was 310 占 폚, and the crystallization temperature was 276 占 폚. The color was L ^* = 100.2, YI = 5.6, and a high polymerization degree polyamide resin was obtained. In addition, the compound of a concentration of the polyamide resin obtained 38 μmol / g, the terminal amino group concentration [NH _2] was 32 μmol / g, terminal carboxyl group concentration [COOH] is 51 μmol / g, the compound and the molar ratio of the terminal amino group is 1.18. L ^* = 96.1, YI = 20.0, and the lightness and yellowness of the sample were inferior to those of the sample after heating treatment at 170 DEG C for 8 hours in a heating oven. When the molded polyamide resin was used to produce molded specimens by injection molding, silver streaks (silver streaks) were slightly formed on the surface of the molded specimens, resulting in molded specimens with poor appearance.

Comparative Example 5: Production of polyamide resin

A polyamide resin having a high polymerization degree was obtained in the same manner as in Example 1 except that the amount of sodium hypophosphite monohydrate (SHM) was changed to 3.760 g (35.47 mmol, 1.0 part by weight with respect to 100 parts by weight of the raw material for injection) .

The IV of the obtained polyamide resin was 1.42 dl / g, the melting point by the DSC measurement was 307 占 폚, and the crystallization temperature was 272 占 폚. The color was L ^* = 99.4 and YI = 9.5, and the polyamide resin was slightly thickened and slightly deteriorated in properties such as melting point and slightly in color. The obtained polyamide resin had a phosphorus compound concentration of 94 μmol / g, a terminal amino group concentration of NH ₂ of 39 μmol / g and a terminal carboxyl group concentration of COOH of 29 μmol / g, and the molar ratio of the phosphorus compound to the terminal amino group 2.39. L ^* = 95.3, YI = 18.5, and the lightness and yellowness of the sample were inferior to those of the sample after heating treatment at 170 DEG C for 8 hours in a heating oven. Injection molding was tried on the obtained polyamide resin, but since the polyamide resin was very thickened and gelated in the molding machine, a molded specimen could not be obtained.

Comparative Example 6: Production of polyamide resin

A polyamide resin having a high polymerization degree was obtained in the same manner as in Example 5 except that the amount of sodium hypophosphite monohydrate (SHM) was changed to 0.372 g (3.51 mmol, 0.1 part by weight with respect to 100 parts by weight of the raw material for injection) .

The IV of the obtained polyamide resin was 0.88 dl / g, the melting point by the DSC measurement was 298 占 폚, and the crystallization temperature was 268 占 폚. The color was L ^* = 100.4, YI = 3.0, and a polyamide resin with a high polymerization degree was obtained. The molar ratio of the phosphorus compound to the terminal amino group in the obtained polyamide resin was 9 μmol / g, the terminal amino group concentration [NH ₂ ] was 64 μmol / g and the terminal carboxyl group concentration [COOH] was 62 μmol / 0.15. L ^* = 96.8, YI = 17.5, and the lightness and yellowness of the sample were inferior after heating treatment at 170 DEG C for 8 hours in a heating oven.

Comparative Example 7: Production of polyamide resin

Except that the injection amount of sodium hypophosphite monohydrate (SHM) was changed to 0.372 g (3.51 mmol, 0.1 part by weight with respect to 100 parts by weight of the starting material for injection) and the time for solid phase polymerization was changed to 6 hours To obtain a polyamide resin having a high polymerization degree.

The IV of the obtained polyamide resin was 0.92 dl / g, the melting point by the DSC measurement was 298 占 폚, and the crystallization temperature was 267 占 폚. The color was L ^* = 100.4, YI = 3.7, and a polyamide resin with high polymerization degree was obtained. Further, the compound concentration in the polyamide resin thus obtained is 9 μmol / g, the terminal amino group concentration [NH _2] was 25 μmol / g, terminal carboxyl group concentration [COOH] is 87 μmol / g, the molar ratio of the compound and the terminal amino group is 0.38. The color of the sample after heat treatment at 170 ° C for 8 hours in a heating oven was L ^* = 97.3 and YI = 15.9, and the lightness and yellowness of the sample were inferior.

Comparative Example 8: Production of polyamide resin

Except that the injection amount of the raw material was changed to 167.72 g (1.009 mol) of terephthalic acid, 204.28 g (1.020 mol) of 1,12-diaminododecane and 3.70 g (0.030 mol) of benzoic acid, A polyamide resin having a high polymerization degree was obtained in the same manner as in Example 5.

The IV of the obtained polyamide resin was 1.08 dl / g, the melting point by the DSC measurement was 297 캜, and the crystallization temperature was 268 캜. The color was L ^* = 100.1, YI = 3.3, and a polyamide resin with high polymerization degree was obtained. The molar ratio of the phosphorus compound to the terminal amino group in the obtained polyamide resin was 38 μmol / g, the terminal amino group concentration [NH ₂ ] was 34 μmol / g and the terminal carboxyl group concentration [COOH] was 57 μmol / 1.10. The color of the sample after heat treatment at 170 ° C for 8 hours in a heating oven was L ^* = 97.7, YI = 16.3, and the brightness and yellowness of the sample were inferior. When molding specimens were produced by injection molding using the obtained polyamide resin, silver streaks (silver streaks) were formed on the surface of specimens, resulting in molded specimens with poor appearance.

Property evaluation method

The evaluation of the logarithmic viscosity (IV), the terminal amino group concentration, the terminal carboxyl group concentration, the melting point, the glass transition temperature, the crystallization temperature and the color, and the preparation of the molding specimen and the evaluation of properties were carried out according to the following methods.

(1) inherent viscosity (IV, η _inh, unit: dl / g): A sample was dissolved at a concentration of 0.5g / dl in 96% concentrated sulfuric acid to prepare a sample solution. 96% concentrated sulfuric acid and the sample solution were measured at a temperature of 25 캜 using a Uberode viscometer and the falling water number was calculated by the following equation (1).

[Formula 1]

Logarithmic viscosity ( η _inh ) = In ( η _rel ) / c

In the equation (1) ,? _Rel is t1 / t0 (t1 is the falling number of samples, t0 is the falling number of the blank), and c is the concentration of the solution (g / dl).

(2) Terminal amino group concentration ([NH ₂ ], unit: μmol / g): 0.3 to 0.5 g of a sample was weighed and dissolved by heating at about 170 ° C. while stirring under nitrogen atmosphere with 20 ml of osocresol. After completely dissolved, the reaction mixture was cooled, 15 ml of benzyl alcohol was added, and the mixture was stirred for 5 minutes. The thus prepared solution was subjected to neutralization titration with 0.1 N hydrochloric acid aqueous solution, and the end point was determined by measuring the potential difference.

(3) Terminal carboxyl group concentration ([COOH], unit: μmol / g): The solution prepared in the same manner as in the measurement of the terminal amino group concentration was subjected to neutralization titration with a 0.1 N KOH (methanolic) solution.

(4) Measurement of the concentration of the phosphorus compound in the resin (unit: μmol / g): Measured using ICP-AES (manufacturer: Agilent Technologies, 720-ES). Sulfuric acid was added to the sample weighed in the crucible and heated, and the ash obtained by the painting treatment was dissolved in potassium hydrogen sulfate, dissolved in dilute nitric acid, and made into a constant volume (static) with pure water. For quantitative analysis, a calibration curve was prepared with a phosphoric acid compound solution of a previously known concentration.

(5) Melting point, glass transition temperature, crystallization temperature (unit: 占 폚): Nitrogen was flowed at a flow rate of 10 ml / min using a DSC manufactured by Seiko Instrument Co., The temperature was raised from 30 占 폚 to 350 占 폚 in 占 폚 / minute, and the temperature was maintained at 5 占 폚 for 10 minutes at a temperature decreasing rate of 10 占 폚 / minute to measure the glass transition temperature, and the endothermic peak And the exothermic peak temperature due to crystallization at the time of cooling was measured as the crystallization temperature.

(6) Color: Measured using a small-color backscattering NW-11 manufactured by Nippon Denshoku Kogyo Co., Ltd. The detailed conditions are as follows.

Illumination and receiving conditions: 45 ° annular illumination, 0 ° receiving

Measuring method: diffraction grating, post spectroscopy

Measurement area: 10 mmΦ, light source: Puls Xenon lamp

Measurement light source, observation condition: D65 / 2 DEG

Measurement items: brightness L ^* , yellowness YI, ΔE ^* .

(7) Heat discoloration test: The sample powders obtained from the examples and the comparative examples were sieved and arranged in a particle diameter of 16 mesh (opening 1,000 占 퐉) and 330 mesh (opening 45 占 퐉) Provided. In the dry heat test, heat treatment was performed in an air oven at 170 DEG C for 8 hours in a heating oven, and the color before and after the treatment was measured to evaluate heat discoloration resistance.

(8) Production of Molded Specimens: Molding specimens were molded at a molding temperature of 310 to 320 占 폚 (polyamide of each of Examples and Comparative Examples) using an injection molding machine (manufactured by Sumitomo Heavy Industries Co., Ltd., SE18DUZ) (Size: 80 mm.times.) At a mold temperature of 150.degree. C., an injection pressure of 120 to 140 MPa, an injection speed of 30 mm / sec, a screw rotation speed of 150 rpm and a cooling time of 45 seconds 0 mm x 4.0 mm).

The evaluation results of the above Examples and Comparative Examples are summarized in Tables 1 and 2 below.

Example One 2 3 4 5 6 7 8 Furtherance TPA (mol%) 100 100 100 100 100 100 100 100 1,10-DDA (mol%) 90 90 90 - - - 90 90 1,12-DDA (mol%) 10 10 10 100 100 100 10 10 SHM (μmol / g) 38 37 38 19 38 38 38 37 Resin Properties IV 0.85 1.11 0.95 0.92 0.97 0.95 0.69 0.71 [NH ₂ ] 75 54 38 37 52 39 56 52 [COOH] 63 29 68 79 52 76 220 18 Phosphorus compound / amine group concentration 0.50 0.70 0.99 0.51 0.73 0.97 0.69 0.71 Melting point 309 309 310 297 299 297 309 309 Crystallization temperature 280 279 282 267 268 269 282 279 L ^* 100.3 100.1 100.0 99.7 100.3 100.7 99.9 99.6 YI 5.7 4.9 5.2 2.5 3.3 3.6 4.6 6.5 Heat discoloration test Color after test L ^* 97.1 97.5 97.3 98.6 99.0 98.1 97.0 96.8 YI 13.7 14.1 14.5 11.4 10.3 12.8 16.5 17.5 Color change DELTA L ^* -3.2 -2.6 -2.7 -1.1 -1.3 -2.6 -2.9 -2.8 ΔE ^* 7.1 7.2 7.2 5.0 4.0 5.5 7.5 8.0 ΔYI 8.0 9.2 9.3 9.0 7.0 9.2 11.9 11.0 Molding specimen appearance Good Good Good Good Good Good Good Good

(TPA: terephthalic acid, 1,10-DDA: 1,10-diaminodecane, 1,12-DDDA: 1,12-diaminododecane, SHM: sodium hypophosphite monohydrate)

Comparative Example One 2 3 4 5 6 7 8 Furtherance TPA (mol%) 100 100 100 100 100 100 100 100 1,10-DDA (mol%) 90 90 90 90 90 - - - 1,12-DDA (mol%) 10 10 10 10 10 100 100 100 SHM (μmol / g) 9 18 9 38 94 9 9 38 Resin Properties IV 1.02 1.04 0.86 1.12 1.42 0.88 0.92 1.08 [NH ₂ ] 55 80 25 32 39 64 25 34 [COOH] 76 53 82 51 29 62 87 57 Phosphorus compound / amine group concentration 0.17 0.23 0.38 1.18 2.39 0.15 0.38 1.10 Melting point 309 309 310 310 307 298 298 297 Crystallization temperature 280 281 282 276 272 268 267 268 L ^* 100.3 100.1 99.1 100.2 99.4 100.4 100.4 100.1 YI 5.5 5.6 6.4 5.6 9.5 3.0 3.7 3.3 Heat discoloration test Color after test L ^* 96.4 96.2 94.9 96.1 95.3 96.8 97.3 97.7 YI 19.3 20.8 22.0 20.0 18.5 17.5 15.9 16.3 Color change DELTA L ^* -3.8 -3.9 -4.2 -4.1 -4.1 -3.6 -3.1 -2.4 ΔE ^* 8.3 9.1 9.4 8.8 6.1 8.5 7.2 7.4 ΔYI 13.8 15.3 15.6 14.3 9.0 14.5 12.2 13.0 Molding specimen appearance Good Good Good A little silver stain Can not be formed Good Good Silver stain

(TPA: terephthalic acid, 1,10-DDA: 1,10-diaminodecane, 1,12-DDDA: 1,12-diaminododecane, SHM: sodium hypophosphite monohydrate)

As apparent from Tables 1 and 2, the polyamide resin of the present invention obtained in Examples 1 to 8 was found to have excellent heat discoloration resistance. On the other hand, it was found that the polyamide resins outside the scope of the present invention obtained in Comparative Examples 1 to 8 were inferior in heat discoloration resistance.

It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

Claims (7)

As a polyamide resin obtained by the polycondensation reaction of a dicarboxylic acid compound and a diamine compound,
(Concentration of phosphorus compound / terminal amino group concentration) of the concentration (unit: 占 퐉 ol / g) of the phosphorus compound contained in the polyamide resin and the terminal amino group concentration (unit: 占 퐉 ol / g) of the polyamide resin is 0.5 to 1.0 And a polyamide resin.
The dicarboxylic acid compound according to claim 1, wherein the dicarboxylic acid compound comprises 30 to 100 mol% of terephthalic acid and 0 to 70 mol% of dicarboxylic acid other than terephthalic acid, and the diamine compound is an aliphatic alkylenediamine 50 And from 0 to 50 mol% of diamines other than aliphatic alkylene diamines having 4 to 25 carbon atoms.
The polyamide resin according to claim 1, wherein the phosphorus compound comprises at least one of hypophosphite, phosphite, phosphate, hypophosphorous acid, phosphorous acid and phosphoric acid.
The polyamide resin according to claim 1, wherein the polyamide resin has a terminal amino group concentration ([NH ₂ ]) of 20 to 100 μmol / g, a terminal carboxyl group concentration ([COOH]) of 20 to 250 μmol / g, / dl and a logarithmic viscosity (IV) measured at a temperature of 25 DEG C of from 0.6 to 1.5 dl / g.
The polyamide resin according to claim 1, wherein the concentration of the phosphorus compound is 10 to 100 占 퐉 ol / g.
A polycondensation reaction of a dicarboxylic acid compound and a diamine compound in the presence of a phosphorus compound to prepare a lower condensate;
Discharging and cooling the lower condensate; And
And subjecting the cooled lower condensate to solid-state polymerization.
7. The method according to claim 6, wherein the ratio (unit: 占 퐉 ol / g) of the phosphorus compound contained in the polyamide resin to the terminal amino group concentration (unit: 占 퐉 ol / g) Amino group concentration) is 0.5 to 1.0.