JP6279262B2 - Polyamide resin - Google Patents

Description

  The present invention relates to a polyamide resin.

  Polyamide resins are widely used as clothing, industrial material fibers, engineering plastics and the like because of their excellent properties and ease of melt molding. In recent years, polyamide resins used in the fields of electric / electronic parts, automobile parts, reflective materials, and the like have been demanded to have better physical properties and functions. In particular, it is desired to develop a polyamide resin that is not easily discolored under heating conditions during polymerization or molding and has an excellent heat-resistant hue.

  Patent Document 1 includes a dicarboxylic acid unit (a) containing 60 to 100 mol% of a terephthalic acid unit, and a diamine unit (b) containing 60 to 100 mol% of an aliphatic alkylenediamine unit having 6 to 18 carbon atoms. There is disclosed a polyamide composition obtained by blending 0.1 to 120 parts by weight of an inorganic filler (B) having an average particle diameter of 2 μm or less with respect to 100 parts by weight of polyamide (A). The polyamide composition is excellent in heat resistance at the time of moisture absorption, dimensional stability, and surface smoothness, and is said to be a suitable material for an LED reflector.

  Patent Document 2 discloses 30 to 95% by weight of a semi-aromatic polyamide in which the ratio of aromatic monomers in all monomer components is 20 mol% or more, and potassium titanate fiber and / or wollastonite 5 to 70% by weight. %, And a resin composition for a reflector containing the same. The reflective plate resin composition is said to exhibit good physical properties such as reflectance, whiteness, and mechanical strength while exhibiting useful physical properties of the polyamide resin.

JP 2000-204244 A JP 2002-294070 A

  However, the polyamide resin described in Patent Document 1 does not necessarily have a sufficient heat resistant hue (discoloration resistance under heating conditions) of the material itself to maintain the luminance when the LED is used at high temperatures due to high luminance and high output. There was a problem of not. In addition, the resin composition described in Patent Document 2 also has a problem in that a decrease in luminance due to a decrease in reflectance due to discoloration of the resin itself cannot be suppressed during high temperature use.

  Then, an object of this invention is to provide the polyamide resin excellent in heat-resistant hue.

  The present inventors have intensively studied to solve the above problems. As a result, the inventors have found that the above problem can be solved by setting the ratio of the concentration of the phosphorus compound contained in the polyamide resin and the terminal amino group concentration of the polyamide resin to a specific range, and have completed the present invention. .

  That is, the present invention relates to a polyamide resin obtained by a polycondensation reaction of a dicarboxylic acid compound and a diamine compound, the concentration of the phosphorus compound contained in the polyamide resin (unit: μmol / g), and the terminal of the polyamide resin. A polyamide resin having a ratio (phosphorus compound concentration / terminal amino group concentration) to an amino group concentration (unit: μmol / g) of 0.5 to 1.0.

  According to the present invention, a polyamide resin excellent in heat-resistant hue can be provided.

  The present invention relates to a polyamide resin obtained by a polycondensation reaction between a dicarboxylic acid compound and a diamine compound, the concentration of the phosphorus compound contained in the polyamide resin (unit: μmol / g), and the terminal amino group of the polyamide resin. It is a polyamide resin whose ratio (concentration of phosphorus compound / terminal amino group concentration) to the concentration (unit: μmol / g) is 0.5 to 1.0. The polyamide resin having such a configuration is excellent in heat-resistant hue (discoloration resistance under heating conditions).

  Hereinafter, the polyamide resin of the present invention will be described in detail.

[Dicarboxylic acid compound]
Although it does not restrict | limit especially as a dicarboxylic acid compound used as the raw material of the polyamide resin of this invention, It is preferable to consist of 30-100 mol% of terephthalic acids and 0-70 mol% of dicarboxylic acids other than terephthalic acid. If it is this range, it will become a polyamide resin excellent in heat-resistant hue. The total amount of terephthalic acid and dicarboxylic acids other than terephthalic acid is 100 mol%.

  The content of terephthalic acid in the dicarboxylic acid compound is preferably 30 to 100 mol%, more preferably 40 to 100 mol%, and still more preferably 50 to 100 mol%. By setting the content of terephthalic acid in the above range, a polyamide resin excellent in heat-resistant hue can be obtained. If the content of terephthalic acid is less than 30 mol%, the heat resistant hue of the polyamide resin may be lowered.

  Specific examples of the dicarboxylic acid other than the terephthalic acid include, for example, malonic acid, dimethylmalonic acid, succinic acid, glutaric acid, adipic acid, 2-methyladipic acid, trimethyladipic acid, pimelic acid, and 2,2-dimethylglutar. Acids, 3,3-diethylsuccinic acid, suberic acid, azelaic acid, sebacic acid, undecanedioic acid, dodecanedioic acid and other aliphatic dicarboxylic acids; 1,3-cyclopentanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, etc. Alicyclic dicarboxylic acid: isophthalic acid, 2,6-naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid, 1,4-naphthalenedicarboxylic acid, 1,4-phenylenedioxydiacetic acid, 1,3-phenylenedi Oxydiacetic acid, diphenic acid, 4,4'-oxydibenzoic acid, diphenylmethane-4,4'- Carboxylic acid, diphenylsulfone-4,4'-dicarboxylic acid, and aromatic dicarboxylic acids such as 4,4'-biphenyl dicarboxylic acid. These dicarboxylic acids other than terephthalic acid can be used alone or in combination of two or more. Among these dicarboxylic acids other than terephthalic acid, 1,4-cyclohexanedicarboxylic acid and isophthalic acid are preferable.

  The content of dicarboxylic acid other than terephthalic acid in the dicarboxylic acid compound is preferably 0 to 70 mol%, more preferably 0 to 60 mol%, and further preferably 0 to 50 mol%. preferable.

  If necessary, a small amount of a polyvalent carboxylic acid such as trimellitic acid, trimesic acid or pyromellitic acid may be used in combination.

[Diamine compound]
Although it does not restrict | limit especially as a diamine compound used as the raw material of the polyamide resin of this invention, 50-100 mol% of C4-C25 aliphatic alkylenediamine, and diamine 0 other than C4-C25 aliphatic alkylenediamine are used. It is preferable to consist of 50 mol%. If it is this range, the polyamide resin excellent in the heat-resistant hue can be obtained. The total amount of the aliphatic alkylene diamine having 4 to 25 carbon atoms and the diamine other than the aliphatic alkylene diamine having 4 to 25 carbon atoms is 100 mol%.

  The content of the aliphatic alkylene diamine having 4 to 25 carbon atoms in the diamine component is preferably 50 to 100 mol%, more preferably 60 to 100 mol%, and 70 to 100 mol%. More preferably.

  Specific examples of the aliphatic alkylene diamine having 4 to 25 carbon atoms include, for example, 1,4-butanediamine, 1,6-hexanediamine (hexamethylenediamine), 1,7-heptanediamine, and 1,8-octanediamine. 1,9-nonanediamine, 1,10-decanediamine, 1,11-undecanediamine, 1,12-dodecanediamine, 2-methyl-1,5-pentanediamine, 3-methyl-1,5-pentanediamine, 2,2,4-trimethyl-1,6-hexanediamine, 2,4,4-trimethyl-1,6-hexanediamine, 2-methyl-1,8-octanediamine, 5-methyl-1,9-nonanediamine Etc. These aliphatic alkylenediamines having 4 to 25 carbon atoms can be used alone or in combination of two or more.

  Specific examples of the diamine other than the aliphatic alkylene diamine having 4 to 25 carbon atoms include, for example, ethylenediamine, propanediamine; cyclohexanediamine, methylcyclohexanediamine, isophoronediamine, bis (4-aminocyclohexyl) methane, 1,3- Cycloaliphatic diamines such as bisaminomethylcyclohexane, 1,4-bisaminomethylcyclohexane, norbornane dimethanamine, tricyclodecane dimethanamine; paraphenylenediamine, metaphenylenediamine, xylylenediamine, 4,4'-diamino Aromatic diamines such as diphenylsulfone and 4,4′-diaminodiphenyl ether can be used. These diamines other than aliphatic alkylene diamine having 4 to 25 carbon atoms can be used alone or in combination of two or more. Among these, bis (4-aminocyclohexyl) methane and xylylenediamine are preferable. The term xylylenediamine includes three isomers, orthoxylylenediamine, metaxylylenediamine (MXDA), and paraxylylenediamine (PXDA).

  The diamine content other than the aliphatic alkylene amine having 4 to 25 carbon atoms in the diamine component is preferably 0 to 50 mol%, more preferably 0 to 40 mol%, and more preferably 0 to 30 mol. % Is more preferable.

  The polyamide resin of the present invention has a ratio (phosphorus compound concentration / terminal) between the concentration (unit: μmol / g) of the phosphorus compound contained in the polyamide resin and the terminal amino group concentration (unit: μmol / g) of the polyamide resin. The amino group concentration is 0.5 to 1.0. When the phosphorus compound concentration / terminal amino group concentration is less than 0.5, discoloration resistance under the heating conditions of the present invention cannot be obtained. On the other hand, when the concentration of the phosphorus compound / terminal amino group concentration exceeds 1.0, gas generation and gelation accompanying side reactions may occur during melt processing. The concentration of the phosphorus compound / terminal amino group concentration is preferably 0.5 to 0.9.

  The concentration of the phosphorus compound / terminal amino group concentration in the polyamide resin of the present invention controls the amount of the phosphorus compound charged, the ratio of the dicarboxylic acid compound and the diamine compound used as the raw material of the polyamide resin, or the degree of polymerization of the polyamide resin. It can control by adjusting etc.

  For example, the terminal amino group concentration becomes relatively low by increasing the charging ratio of the dicarboxylic acid compound to the diamine compound. Further, by increasing the degree of polymerization of the polyamide resin, both the terminal amino group concentration and the terminal carboxyl group concentration are lowered. In the present invention, as long as the phosphorus compound concentration / terminal amino group concentration is within a predetermined range, the charging 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. For example, after setting the necessary degree of polymerization so as to match the use of the polyamide resin, it is possible to determine the charging ratio of the dicarboxylic acid compound or the diamine compound according to the amount of the phosphorus compound to be added.

  The phosphorus compound contained in the polyamide resin of the present invention is not particularly limited. For example, hypophosphite, phosphite, phosphate, hypophosphorous acid, phosphorous acid, phosphoric acid, phosphate ester, polymetaphosphoric acid, polyphosphoric acid, phosphine oxide, or phosphonium halogen compound It is done. These are preferable because they are suitably used as a catalyst for the production of a low-order condensate described later. Furthermore, at least 1 selected from the group consisting of hypophosphite, phosphite, phosphate, hypophosphorous acid, phosphorous acid, and phosphoric acid from the viewpoint of resistance to discoloration under heating conditions Species are more preferable, and at least one selected from the group consisting of hypophosphite, phosphate, hypophosphorous acid, and phosphoric acid is more preferable.

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

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

  Examples of phosphates include sodium phosphate, potassium phosphate, potassium dihydrogen phosphate, calcium phosphate, vanadium phosphate, magnesium phosphate, manganese phosphate, lead phosphate, nickel phosphate, cobalt phosphate, phosphoric acid. Examples include ammonium and diammonium hydrogen phosphate.

  Examples of phosphate esters include monomethyl phosphate ester, dimethyl phosphate ester, trimethyl phosphate, monoethyl phosphate ester, diethyl phosphate ester, triethyl phosphate, propyl phosphate ester, dipropyl phosphate ester, tripropyl phosphate, isopropyl Phosphate ester, diisopropyl phosphate ester, triisopropyl phosphate, butyl phosphate ester, dibutyl phosphate ester, tributyl phosphate, isobutyl phosphate ester, diisobutyl phosphate ester, triisobutyl phosphate, hexyl phosphate ester, dihexyl phosphate ester, Trihexyl phosphate, octyl phosphate, dioctyl phosphate, trioctyl phosphate, 2-ethylhexyl phosphate, di (2-ethylhexyl) phosphate Ter, tri (2-ethylhexyl) phosphate decyl phosphate, didecyl phosphate, tridecyl phosphate, isodecyl phosphate, diisodecyl phosphate, triisodecyl phosphate, stearyl phosphate, distearyl phosphate, tristearyl phosphate Examples include acid, monophenyl phosphate, diphenyl phosphate, triphenyl phosphate, and ethyl octadecyl phosphate.

  Examples of the polymetaphosphoric acid include sodium trimetaphosphate, sodium pentametaphosphate, sodium hexametaphosphate, polymetaphosphoric acid and the like. Examples of polyphosphoric acids include sodium tetrapolyphosphate. Examples of phosphine oxides include hexamethylphosphoramide. These phosphorus compounds may be in the form of hydrates.

  Among these phosphorus compounds, sodium hypophosphite or a hydrate thereof, sodium phosphite or a hydrate thereof is preferable.

  In addition, the said phosphorus compound can be used individually or in mixture of 2 or more types.

  The concentration of the phosphorus compound contained in the polyamide resin of the present invention is preferably 10 to 100 μmol / g, and more preferably 30 to 70 μmol / g. When the phosphorus compound concentration is less than 10 μmol, it may be difficult to obtain the effect of improving the heat-resistant hue by the phosphorus compound. On the other hand, when the phosphorus compound concentration exceeds 100 μmol / g, side reactions such as gelation may easily occur. The concentration of the phosphorus compound can be measured by a method using an inductively coupled plasma emission spectrometer (ICP-AES), more specifically, by the method described in the examples.

  The addition (preparation) of the phosphorus compound to the polyamide resin of the present invention is performed together with the raw material when the low-order condensate is produced as described above, and the produced low-order condensate is impregnated with a solution of the phosphorus compound. There is an example in which solid-phase polymerization or the like is carried out after dispersion by the above means, and there is no particular limitation. In order to obtain the effect of discoloration resistance, it is more preferable to add it when producing a low-order condensate.

Further, the terminal amino group concentration ([NH ₂ ]) of the polyamide resin of the present invention is preferably 20 to 100 μmol / g, and more preferably 30 to 80 μmol / g. When the terminal amino group concentration is less than 20 μmol / g, the polycondensation reaction is performed at a high temperature for the purpose of increasing the reaction rate of the polycondensation reaction, so that the heat resistant hue may be lowered by the thermal history. On the other hand, when it exceeds 100 μmol / g, the terminal amino group is likely to be colored, so that the heat resistant hue (discoloration resistance in a heating environment) may be lowered. The terminal amino group concentration can be measured by a titration method, and more specifically can be measured by the method described in the examples.

  Moreover, the terminal carboxy group concentration ([COOH]) of the polyamide resin of the present invention is preferably 20 to 250 μmol / g, and more preferably 30 to 200 μmol / g. When the terminal carboxy group concentration is less than 20 μmol / g, the polycondensation reaction is carried out at a high temperature for the purpose of increasing the reaction rate of the polycondensation reaction. On the other hand, if it exceeds 250 μmol / g, the degree of polymerization is insufficient and it may be difficult to obtain the desired molding material. The terminal carboxy group concentration can be measured by a titration method, and more specifically can be measured by the method described in the Examples.

  In the polyamide resin of the present invention, the logarithmic viscosity (IV) measured at 25 ° C. at a concentration of 0.5 g / dL in concentrated sulfuric acid is preferably 0.6 to 1.5, and preferably 0.7 to 1 .3 is more preferable. When IV is less than 0.6, the content of a component having a low degree of polymerization increases, so that the heat resistant hue may be lowered. On the other hand, when IV exceeds 1.5, the discoloration resistance in a heating environment may be lowered due to deterioration due to thermal history during polymerization. In addition, IV can be specifically measured by the method as described in the below-mentioned Example.

  The melting point of the polyamide resin of the present invention is preferably 280 ° C. or higher, and more preferably 290 ° C. or higher. The crystallization temperature of the polyamide resin of the present invention is preferably 250 ° C. or higher, and more preferably 260 ° C. or higher.

  The melting point and crystallization temperature can be specifically measured by the methods described in the examples.

  The method for producing the polyamide resin of the present invention is not particularly limited, but a step of producing a low-order condensate by performing a polycondensation reaction between the dicarboxylic acid compound and the diamine compound, and discharging and cooling the low-order condensate. A production method comprising a step and a step of solid-phase polymerization of the cooled low-order condensate is preferable. According to such a production method, it is possible to obtain a polyamide resin excellent in heat-resistant hue without causing almost any production problems such as generation of gel during production.

  Hereinafter, although such a manufacturing method is demonstrated in detail for every process, this invention is not restrict | limited at all to this.

<Process for producing low-order condensate>
In this step, a polycondensation reaction between the dicarboxylic acid compound and the diamine compound is performed to produce a low-order condensate of polyamide resin.

  The low-order condensate is synthesized by, for example, charging an aqueous solution of the above-mentioned monomer or salt into a commonly used pressure polymerization tank and performing a polycondensation reaction in an aqueous solvent under stirring conditions.

  The aqueous solvent is a solvent mainly composed of water. The solvent used other than water is not particularly limited as long as it does not affect the polycondensation reactivity and solubility. For example, alcohols such as methanol, ethanol, propanol, butanol, and ethylene glycol are used. Is mentioned.

  The amount of water in the reaction system when starting the polycondensation reaction is preferably such that the amount of water in the reaction system at the end of the reaction is 15 to 35% by weight. Specifically, the amount of water in the reaction system when starting the polycondensation reaction is preferably 17 to 60% by weight. If the amount of water in the reaction system at the start of the polycondensation reaction is within this range, an almost uniform solution is formed at the start of the polycondensation reaction, which is excessive to distill off the water in the polycondensation step. There is no risk of requiring time and energy, and thermal degradation of the low-order condensate due to extension of the reaction time can be reduced.

  In this step, a phosphorus catalyst can be used from the viewpoints of improving the polycondensation rate and preventing deterioration during the polycondensation reaction. Phosphorous catalysts include hypophosphites, phosphites, phosphates, hypophosphorous acid, phosphorous acid, phosphoric acid, phosphate esters, polymetaphosphoric acids, polyphosphoric acids, phosphine oxides, or phosphonium halogens The compound is preferred, and at least one selected from the group consisting of hypophosphite, phosphite, phosphate, hypophosphorous acid, phosphorous acid, and phosphoric acid is more preferred, and hypophosphite More preferred is at least one selected from the group consisting of phosphonate, hypophosphorous acid, and phosphoric acid. Specific examples of these phosphorus-based catalysts are the same as the specific examples of the above-described phosphorus compounds, and thus description thereof is omitted here.

  As addition amount of a phosphorus catalyst (phosphorus compound), 0.1-1.0 weight part is preferable with respect to 100 weight part of total monomers, and 0.2-0.5 weight part is more preferable. The catalyst may be added at any time as long as the solid phase polymerization is completed, but it is preferable that the catalyst is added from the raw material charging to the completion of polycondensation of the low-order condensate. Moreover, you may add many times. Further, two or more different phosphorus catalysts may be added in combination.

  Moreover, this process can perform above-described polycondensation reaction in presence of terminal blocker. Use of the end-capping agent makes it easier to adjust the molecular weight of the low-order condensate and finally produced polyamide resin, and further improves the melt stability of the low-order condensate and finally produced polyamide resin. The end capping agent is not particularly limited as long as it is a monofunctional compound having reactivity with the terminal amino group or terminal carboxyl group in the low-order condensate. For example, acid such as monocarboxylic acid, monoamine, phthalic anhydride, etc. Anhydrides, monoisocyanates, monoacid halides, monoesters, monoalcohols and the like can be mentioned. The terminal blocking agents can be used alone or in combination of two or more.

  Among these, monocarboxylic acids or monoamines are preferably used as end capping agents from the viewpoints of reactivity and stability of the capping ends, and in addition to the above properties, monocarboxylic acids are easy to handle. Is more preferably used.

  The monocarboxylic acid preferably used as the end-capping agent is not particularly limited as long as it is a monocarboxylic acid having reactivity with an amino group. For example, acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, capryl Aliphatic monocarboxylic acids such as acid, lauric acid, tridecylic acid, myristic acid, palmitic acid, stearic acid, pivalic acid and isobutyric acid; alicyclic monocarboxylic acids such as cyclohexanecarboxylic acid; benzoic acid, toluic acid, α- Mention may be made of aromatic monocarboxylic acids such as naphthalenecarboxylic acid, β-naphthalenecarboxylic acid, methylnaphthalenecarboxylic acid, phenylacetic acid, or any mixture thereof. Among these, acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, caprylic acid, lauric acid, tridecylic acid, myristic acid, palmitic acid, stearic acid, in terms of reactivity, stability of the sealing end, price, etc. Benzoic acid is more preferred.

  The monoamine preferably used as the end-capping agent is not particularly limited as long as it is a monoamine having reactivity with a carboxyl group. For example, methylamine, ethylamine, propylamine, butylamine, hexylamine, octylamine, decylamine, Aliphatic monoamines such as stearylamine, dimethylamine, diethylamine, dipropylamine, dibutylamine; alicyclic monoamines such as cyclohexylamine, dicyclohexylamine; aromatic monoamines such as aniline, toluidine, diphenylamine, naphthylamine, or any of these Mention may be made of mixtures. Among these, butylamine, hexylamine, octylamine, decylamine, stearylamine, cyclohexylamine, and aniline are particularly preferable from the viewpoints of reactivity, boiling point, stability of the capped end and price.

  The amount of the end-capping agent used in the production of the low-order condensate may vary depending on the reactivity, boiling point, reaction apparatus, reaction conditions, etc. of the end-capping agent used, It is preferable to use within the range of 0.1-15 mol%.

  The synthesis of the low-order condensate of the present invention is usually carried out by raising the temperature and raising the pressure under stirring conditions. The polymerization temperature is controlled after the raw materials are charged. The polymerization pressure is controlled in accordance with the progress of the polymerization.

  The reaction temperature in this step is preferably 230 to 260 ° C. If it is this range, side reactions, such as gelatinization, do not occur easily and the target low-order condensate can be obtained efficiently. The reaction temperature is more preferably 240 to 250 ° C.

  The reaction pressure in this step is preferably 0.5 to 5 MPa. If the reaction pressure is within this range, the temperature in the reaction system and the amount of water in the reaction system can be easily controlled, and the low-order condensate can be easily discharged. Moreover, since a reactor with low pressure resistance can be used, it is economically advantageous, and the degree of polymerization of the low-order condensate can be increased by shifting the amount of water in the reaction system low. The reaction pressure is more preferably 1.0 to 4.5 MPa.

  Moreover, it is preferable that the reaction time in this process is 0.5 to 4 hours. The reaction time here refers to the time required from the arrival of the reaction temperature of the present invention to the start of the discharge operation. When the reaction time is within this range, a sufficient reaction rate is reached, and unreacted substances hardly remain, and a low-order condensate with uniform properties can be obtained. Moreover, a high-quality low-order condensate can be obtained without giving an excessive heat history. The reaction time is more preferably 1 to 3 hours.

  The water content in the reaction system at the end of the reaction of the low-order condensate in this step is preferably 15 to 35% by weight. The term “at the end of the reaction” as used herein means a time point at which a low-order condensate having a predetermined degree of polymerization is reached and a discharge operation is started, and the amount of condensed water generated during the reaction is also combined. In order to make the amount of water within the scope of the present invention, a predetermined amount of water is distilled off when adjusting the reaction pressure in a device equipped with a condenser and a pressure regulating valve in order to make the amount of water charged taking into account the amount of generated condensed water. Can be adjusted. If the water content is within this range, the low-order condensate is hardly precipitated or solidified in the reaction system, and the discharge of the low-order condensate is facilitated. In addition, it is easy to obtain a low-order condensate having a sufficient degree of polymerization, and since the amount of water 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. The amount of water in the reaction system at the end of the reaction is more preferably 20 to 35% by weight.

  Further, before the polymerization of the low-order condensate, a salt preparation step and / or a concentration step can be added as necessary. The salt tone is a step of producing a salt from a dicarboxylic acid component and a diamine component, and in the range of pH ± 0.5 of the neutralization point of the salt, and further, pH ± 0.3 of the neutralization point of the salt. It is preferable to adjust to the range. In the concentration, the raw material charge concentration value is preferably +2 to + 90% by weight, and more preferably concentrated to a concentration of +5 to + 80% by weight. The temperature in the concentration step is preferably in the range of 90 to 220 ° C, more preferably 100 to 210 ° C, and particularly preferably 130 to 200 ° C. The pressure in the concentration step is preferably 0.1 to 2.0 MPa. Usually, the concentration pressure is controlled below the polymerization pressure. Further, for the purpose of promoting concentration, for example, a forced discharge operation can be performed by a nitrogen stream or the like. The concentration step is effective for shortening the polymerization time.

  In this step, the logarithmic viscosity (hereinafter also simply referred to as IV) measured at a temperature of 25 ° C. at a concentration of 0.5 g / dL in concentrated sulfuric acid of the low-order condensate after being taken out of the reaction vessel (after cooling). The reaction is preferably carried out at 0.07 to 0.40 dL / g. If IV is in this range, the fusion of resin powders during solid phase polymerization due to the presence of a low-melting substance and adhesion to the apparatus can be suppressed, and the reaction during the production of low-order condensates can be suppressed. Precipitation and solidification in the system can be suppressed. The IV is more preferably 0.10 to 0.25 dL / g.

  In this step, the polycondensation reaction for obtaining a low-order condensate may be performed in a batch manner or a continuous manner. Moreover, it is preferable to perform the polycondensation reaction for producing | generating a low-order condensate under stirring from points, such as adhesion prevention of the low-order condensate to a reaction container, and a uniform progression of a polycondensation reaction.

<Process for discharging and cooling low-order condensate>
Next, the low-order condensate produced above is taken out from the reaction vessel. When taking out the low-order condensate from the reaction vessel, the temperature of the reaction system is in the range of 230 to 260 ° C., and the water content in the reaction system at the end of the reaction is in the range of 15 to 35% by weight. Sometimes it is preferred to remove the low-order condensate from the reaction vessel in an inert gas atmosphere at a pressure below atmospheric pressure. According to such a discharge method, it is not necessary to use a pressure vessel for removal adjusted to a predetermined pressure, and it is also necessary to take out the low-order condensate from the reaction vessel while separately supplying water vapor into the reaction vessel. Without obtaining a low-order condensate in a non-foamed granular form (powder or granular form) that has low thermal degradation, sufficiently high logarithmic viscosity, and high bulk specific gravity. be able to.

  The inert gas atmosphere preferably has an oxygen concentration of 1% by volume or less from the viewpoint of preventing oxidative degradation of the low-order condensate.

The discharge rate of the low-order condensate from the reaction vessel can be appropriately adjusted according to the scale of the reaction vessel, the amount of contents in the reaction vessel, the temperature, the size of the take-out port, the length of the take-out nozzle portion, and the like. However, in general, it is preferable that the discharge speed per discharge port cross-sectional area be within a range of 2000 to 20000 kg / s / m ² . Within this range, in the solid phase polymerization process described later, collapse, aggregation, fusion to the reactor wall, etc. are unlikely to occur, the handleability is excellent, and the polymerization apparatus can be filled in a large amount. The volumetric efficiency of the apparatus used in the polymerization process can be improved.

  The low-order condensate taken out from the reaction vessel is instantaneously reduced to preferably 100 ° C. or less due to the latent heat of vaporization of the water at the time of taking-out, so that thermal degradation and deterioration due to oxygen hardly occur.

  In addition, the discharged low-order condensate evaporates most of the accompanying water due to the sensible heat of the low-order condensate, so the cooling of the low-order condensate and the drying process are performed simultaneously in this step. is there. It is preferable to perform the discharge treatment under the flow of an inert gas such as nitrogen or under reduced pressure from atmospheric pressure in order to increase the efficiency of drying and cooling. In addition, by installing a cyclone-type solid-gas separation device as a discharge container, not only can the powder be prevented from scattering outside the system, but also the discharge process can be performed at a high gas linear velocity, so drying and cooling efficiency can be improved. This is preferable because it can be increased.

  The low-order condensate thus obtained has a sufficiently high logarithmic viscosity as described above, and the residual amount of unreacted material is also low. The solid-phase polymerization can be carried out at a high temperature without causing fusion or aggregation of the resin, and there is little deterioration due to side reactions.

  Moreover, in this process, you may further perform the compacting process and granulation process for aligning a particle size as needed.

<Solid-state polymerization>
In this step, the low-order condensate taken out from the reaction vessel in the above is subjected to a high degree of polymerization by solid phase polymerization to produce a polyamide resin. The solid phase reaction may be carried out as it is after taking out the low-order condensate from the reaction vessel, or after drying the low-order condensate taken out from the reaction vessel, or the low-order condensate taken out from the reaction vessel. May be carried out after storage, or after the above-described compacting treatment or granulation treatment is performed on the low-order condensate taken out from the reaction vessel. When the degree of polymerization is increased by solid phase polymerization, a polyamide resin with less heat deterioration can be obtained.

  The polymerization method and conditions for solid-phase polymerization of the low-order condensate are not particularly limited, and a method capable of increasing the degree of polymerization while maintaining a solid state without causing fusion, aggregation, or deterioration of the low-order condensate and Any condition is acceptable.

  However, in order to prevent oxidative degradation of the low-order condensate and the resulting polyamide resin, it is preferable to perform solid-state polymerization in an inert gas atmosphere such as helium gas, argon gas, nitrogen gas, carbon dioxide gas, or under reduced pressure. .

  The reaction temperature in the solid phase polymerization is not particularly limited, but is preferably 200 to 250 ° C, more preferably 210 to 240 ° C.

  There is no particular limitation on the solid-phase polymerization apparatus used in this step, and any known apparatus can be used. Specific examples of the solid phase polymerization apparatus include, for example, a uniaxial disk type, a kneader, a biaxial paddle type, a vertical tower type apparatus, a vertical tower type apparatus, a rotary drum type, or a double cone type solid phase polymerization. Examples thereof include an apparatus and a drying device.

  The reaction time of solid phase polymerization is not particularly limited, but usually 1 to 20 hours is preferably employed. During the solid state polymerization reaction, the low-order condensate may be stirred mechanically or by a gas stream.

  In the present invention, various fiber materials such as glass fibers and carbon fibers, inorganic powders, if necessary, in a step of producing a low-order condensate, a step of solid-phase polymerization, or an arbitrary step after solid-phase polymerization. Additives such as fillers, organic powder fillers, colorants, UV absorbers, light stabilizers, antioxidants, antistatic agents, flame retardants, crystallization accelerators, plasticizers, lubricants, and other polymers May be.

  According to the manufacturing method as described above, a polyamide resin excellent in heat-resistant hue can be obtained with almost no manufacturing problems such as gelation.

  The polyamide resin of the present invention is excellent in heat resistant hue. Therefore, taking advantage of this property, various molding methods conventionally used for polyamide resins in the form of a composition with the various kinds of additives and other polymers described above alone or as required. Various molded products and fibers can be formed by a spinning method such as injection molding, blow molding, extrusion molding, compression molding, stretching, vacuum molding, or the like, or melt spinning. The resulting molded products and fibers can be used effectively for various applications such as engineering plastics, industrial materials such as electronic / electric parts, automobile parts, office machine parts, industrial materials, and household goods. can do. In particular, LED light-emitting devices, various electronic and electrical components, automobile keyless entry systems, refrigerator interior lighting, backlights for liquid crystal display devices, automotive front panel lighting devices, lighting stands, bed lights, household appliance indicators, infrared communications It can be suitably used as a reflective material or reflector for optical communication devices such as ceiling lighting devices.

  The present invention will be described in further detail using the following examples and comparative examples. However, the technical scope of the present invention is not limited only to the following examples. In addition, evaluation of logarithmic viscosity (IV), terminal amino group concentration, terminal carboxyl group concentration, melting point, glass transition temperature, crystallization temperature, and hue, and preparation and physical property evaluation of test pieces were performed by the following methods.

(1) Logarithmic viscosity A sample solution was prepared by dissolving a sample in 96% concentrated sulfuric acid at a concentration of 0.5 g / dL. The falling seconds of 96% concentrated sulfuric acid and the sample solution were measured using a Ubbelohde viscosity tube at a temperature of 25 ° C., and calculated according to the following formula.

(2) Terminal amino group concentration ([NH ₂ ])
0.3 to 0.5 g of the sample was precisely weighed, 20 mL of orthocresol was added, and the mixture was dissolved by heating to about 170 ° C. with stirring in a nitrogen atmosphere. After complete dissolution, the mixture was cooled, and 15 mL of benzyl alcohol was added, followed by stirring for 5 minutes. The solution thus prepared was subjected to neutralization titration with a 0.1N hydrochloric acid aqueous solution, and the end point was determined by potentiometric measurement.

(3) Terminal carboxyl group concentration ([COOH])
The solution prepared in the same manner as the terminal amino group concentration measurement was subjected to neutralization titration with a 0.1N KOH (methanolic) solution, and the end point was determined by potentiometric measurement.

(4) Measurement of concentration of phosphorus compound in resin Measuring device: ICP-AES 720-ES manufactured by Agilent Technologies
Sample pretreatment: Sulfuric acid was added to a sample weighed in a crucible, heated and incinerated.

  The ash was dissolved in potassium hydrogen sulfate and then dissolved in dilute nitric acid, and the volume was adjusted with pure water. For quantitative analysis, a calibration curve was previously prepared with a phosphorus compound solution having a known concentration.

(5) Melting point, glass transition temperature, crystallization temperature Using a DSC manufactured by Seiko Instruments Inc., a non-crystallized sample was flowed from 30 ° C. at a heating rate of 10 ° C./min under a nitrogen flow at a flow rate of 10 ml / min. After raising the temperature to 350 ° C., hold for 5 minutes, measure to 100 ° C. at a rate of temperature drop of 10 ° C./min, measure the glass transition temperature, and use the endothermic peak temperature due to melting at the time of temperature rise as the melting point. The exothermic peak temperature due to was measured as the crystallization temperature.

(6) Hue The hue was measured using a small color whiteness meter NW-11 manufactured by Nippon Denshoku Industries Co., Ltd.

Illumination / light reception conditions: 45 ° annular illumination, 0 ° light reception Measurement method: diffraction grating, post-spectral method Measurement area: 10 mmφ, light source: Pulse Xenon lamp
Measurement light source, observation conditions: D65 / 2 °
Measurement items: lightness L ^* , yellowness YI, ΔE.

(7) Discoloration resistance test (heat resistant hue)
The sample powders obtained in the examples and comparative examples were screened to obtain a particle size of 16 mesh (aperture 1,000 μm) passing and 330 mesh (aperture 45 μm) not passing, and then subjected to a dry heat test. Provided. In the dry heat test, heat treatment was performed in a heating oven in an air atmosphere at 170 ° C. for 8 hours, and the hue before and after the treatment was measured to evaluate discoloration resistance (heat resistant hue).

(8) Preparation of test piece Using a SE18DUZ which is an injection molding machine manufactured by Sumitomo Heavy Industries, Ltd., a strip-like test piece (size 80 mm × 10 mm × 4.0 mm) was prepared under the conditions shown in Table 1 below. .

Example 1
As raw materials, 179.72 g (1.082 mol) of terephthalic acid, 170.28 g (0.988 mol = 90 mol%) of 1,10-diaminodecane, 22.00 g (0.110 mol = 0.110 mol =) 10 mol%), 3.96 g (0.032 mol) of benzoic acid, 1.504 g of sodium hypophosphite monohydrate (SHM) (14.19 mmol, 0.4 parts by weight based on the charged materials), and 251 g of water (40% by weight with respect to the charged raw materials) was charged into an autoclave reaction tank having an internal volume of 1 liter equipped with a pressure reducer, a pressure regulating valve, and a bottom discharge valve, and nitrogen substitution was performed. While stirring, the temperature was raised to 180 ° C. over 1 hour and held for 0.5 hour. Thereafter, the internal temperature was raised to 250 ° C. and held over 1 hour. After the internal pressure of the reaction tank reached 3.5 MPa, the reaction was continued for 2.5 hours while distilling off water so as to maintain the same pressure.

  After the predetermined reaction time has elapsed, while maintaining the temperature of the reaction vessel and the amount of water in the reaction system (30% by weight), the produced low-order condensate is passed through the bottom discharge valve at room temperature (25 ° C.) under nitrogen flow. And discharged to a receiver under atmospheric pressure conditions to obtain a white, powdery low-order condensate.

  300 g of the obtained low-order condensate was charged into a 1000 mL round bottom flask, placed in a rotary evaporator with an oil bath, and purged with nitrogen, and then immersed in an oil bath while rotating the flask under a nitrogen flow of 1 L / min. After raising the internal temperature to 230 ° C. over 1 hour, the solid state polymerization reaction was continued at the same temperature for 5 hours. After a predetermined reaction time, the mixture was cooled to room temperature (25 ° C.) to obtain a highly polymerized polyamide resin.

The obtained polyamide resin had an IV of 0.85, a melting point measured by DSC of 309 ° C., and a crystallization temperature of 280 ° C. The hue was L ^* = 100.3 and YI = 5.7, and a polyamide resin having a good hue with a sufficiently high degree of polymerization was obtained. In the obtained polyamide resin, the phosphorus compound concentration 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 / g. The molar ratio was 0.50. The hue 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. When a test piece was prepared by injection molding using the obtained polyamide resin, there was no sink mark due to poor filling, silvery traces due to generation of moisture, gas, etc., contamination of koge or gel, and hue such as yellowing Thus, a test piece of polyamide resin having a good appearance and hue without any abnormalities was obtained.

(Example 2)
A polyamide resin having a high degree of polymerization was obtained in the same manner as in Example 1 except that the solid-state polymerization temperature was 240 ° C.

The obtained polyamide resin had an IV of 1.11, a melting point of 309 ° C. as measured by DSC, and a crystallization temperature of 279 ° C. The hues were L ^* = 100.1 and YI = 4.9, and a polyamide resin having a satisfactory hue with a sufficiently high degree of polymerization was obtained. The obtained polyamide resin had a phosphorus compound concentration of 37 μmol / g, a terminal amino group concentration [NH ₂ ] of 54 μmol / g, and a terminal carboxyl group concentration [COOH] of 29 μmol / g. The molar ratio of was 0.70. The hue of the sample after heat treatment at 170 ° C. for 8 hours in a heating oven was L ^* = 97.1 and YI = 14.1, and the lightness and yellowness of the sample were good. When a test piece was prepared by injection molding using the obtained polyamide resin, there was no sink mark due to poor filling, silvery traces due to generation of moisture, gas, etc., contamination of koge or gel, and hue such as yellowing Thus, a test piece of polyamide resin having a good appearance and hue without any abnormalities was obtained.

(Example 3)
The amount of raw materials charged was 180.64 g (1.087 mol) of terephthalic acid, 169.46 g (0.983 mol = 90 mol%) of 1,10-diaminodecane, 21.89 g (0. 89 g) of 1,12-diaminododecane. 109 mol = 10 mol%), 3.98 g (0.033 mol) of benzoic acid, and a polyamide having a high degree of polymerization in the same manner as in Example 1 except that the temperature of solid phase polymerization was 240 ° C. A resin was obtained.

The obtained polyamide resin had an IV of 0.95, a melting point of 310 ° C. as measured by DSC, and a crystallization temperature of 282 ° C. The hue was L ^* = 100.0 and YI = 5.2, and a polyamide resin having a good hue with a sufficiently high degree of polymerization was obtained. The obtained polyamide resin has a phosphorus compound concentration of 38 μmol / g, a terminal amino group concentration [NH ₂ ] of 38 μmol / g, and a terminal carboxyl group concentration [COOH] = 68 μmol / g. The molar ratio was 0.99. The hue of the sample after heat treatment at 170 ° C. for 8 hours in a heating oven was L ^* = 97.3, YI = 14.5, and the sample was good in lightness and yellowness. When a test piece was prepared by injection molding using the obtained polyamide resin, there was no sink mark due to poor filling, silvery traces due to generation of moisture, gas, etc., contamination of koge or gel, and hue such as yellowing Thus, a test piece of polyamide resin having a good appearance and hue without any abnormalities was obtained.

Example 4
The amount of raw materials charged was terephthalic acid 168.17 g (1.012 mol), 1,12-diaminododecane 203.83 g (1.017 mol), benzoic acid 3.71 g (0.030 mol), hypophosphorous acid Sodium monohydrate (SHM) 0.744 g (7.02 mmol, 0.2 parts by weight with respect to the charged raw materials), the internal temperature during the production of the low-order condensate was controlled at 240 ° C. and the internal pressure was controlled at 2.4 MPa. A polyamide resin having a high degree of polymerization was obtained in the same manner as in Example 1 except that the solid-state polymerization temperature was 220 ° C.

The obtained polyamide resin had an IV of 0.92, a melting point measured by DSC of 297 ° C., and a crystallization temperature of 267 ° C. The hue was L ^* = 99.7 and YI = 2.5, and a polyamide resin having a good hue with a sufficiently high degree of polymerization was obtained. The obtained polyamide resin had a phosphorus compound concentration of 19 μmol / g, a terminal amino group concentration [NH ₂ ] of 37 μmol / g, and a terminal carboxyl group concentration [COOH] of 79 μmol / g. The molar ratio of was 0.51. The hue of the sample after heat treatment at 170 ° C. for 8 hours in a heating oven was L ^* = 98.6, YI = 11.4, and the brightness and yellowness of the sample were good. When a test piece was prepared by injection molding using the obtained polyamide resin, there was no sink mark due to poor filling, silvery traces due to generation of moisture, gas, etc., contamination of koge or gel, and hue such as yellowing Thus, a test piece of polyamide resin having a good appearance and hue was obtained.

(Example 5)
The amount of raw materials charged was 167.26 g (1.007 mol) of terephthalic acid, 204.74 g (1.022 mol) of 1,12-diaminododecane, 3.69 g (0.030 mol) of benzoic acid, and hypophosphorous acid. A polyamide resin having a high degree of polymerization was prepared in the same manner as in Example 4 except that 1.488 g (14.04 mmol, 0.4 part by weight based on the charged raw materials) of sodium monohydrate (SHM) was used. Obtained.

The obtained polyamide resin had an IV of 0.97, a melting point of 299 ° C. as measured by DSC, and a crystallization temperature of 268 ° C. The hue was L ^* = 100.3 and YI = 3.3, and a polyamide resin having a good hue with a sufficiently high degree of polymerization was obtained. The obtained polyamide resin had a phosphorus compound concentration of 38 μmol / g, a terminal amino group concentration [NH ₂ ] of 52 μmol / g, and a terminal carboxyl group concentration [COOH] of 52 μmol / g. The molar ratio of was 0.73. The hue of the sample after heat treatment at 170 ° C. for 8 hours in a heating oven was L ^* = 99.0 and YI = 10.3, and the lightness and yellowness of the sample were good. When a test piece was prepared by injection molding using the obtained polyamide resin, there was no sink mark due to poor filling, silvery traces due to generation of moisture, gas, etc., contamination of koge or gel, and hue such as yellowing Thus, a test piece of polyamide resin having a good appearance and hue without any abnormalities was obtained.

(Example 6)
Sodium hypophosphite monohydrate (SHM) 1.488 g (14.04 mmol, 0.4 parts by weight with respect to the charged raw material), the internal temperature during the production of the low-order condensate is 250 ° C., and the internal pressure is 3. A polyamide resin having a high degree of polymerization was obtained in the same manner as in Example 4 except that the temperature was controlled at 5 MPa and the solid-state polymerization temperature was 230 ° C.

The obtained polyamide resin had an IV of 0.95, a melting point measured by DSC of 297 ° C., and a crystallization temperature of 269 ° C. The hue was L ^* = 100.7 and YI = 3.6, and a polyamide resin having a good hue with a sufficiently high degree of polymerization was obtained. The obtained polyamide resin has a phosphorus compound concentration of 38 μmol / g, a terminal amino group concentration [NH ₂ ] of 39 μmol / g, and a terminal carboxyl group concentration [COOH] of 76 μmol / g. The molar ratio of was 0.97. The hue of the sample after heat treatment at 170 ° C. for 8 hours in a heating oven was L ^* = 98.1 and YI = 12.8, and the brightness and yellowness of the sample were good. When a test piece was prepared by injection molding using the obtained polyamide resin, there was no sink mark due to poor filling, silvery traces due to generation of moisture, gas, etc., contamination of koge or gel, and hue such as yellowing Thus, a test piece of polyamide resin having a good appearance and hue without any abnormalities was obtained.

(Example 7)
The amount of raw materials charged was 182.42 g (1.098 mol) of terephthalic acid, 167.89 g of 1,10-diaminodecane (0.974 mol = 90 mol%), 21.69 g of 1,12-diaminododecane (0. 108 mol = 10 mol%), 4.02 g (0.033 mol) of benzoic acid, and a polyamide having a high degree of polymerization in the same manner as in Example 1 except that the temperature of solid phase polymerization was 240 ° C. A resin was obtained.

The obtained polyamide resin had an IV of 0.65, a melting point by DSC measurement of 309 ° C., and a crystallization temperature of 282 ° C. The hue was L ^* = 99.9 and YI = 4.6, and a polyamide resin having a satisfactory hue with a sufficiently high degree of polymerization was obtained. The obtained polyamide resin had a phosphorus compound concentration of 38 μmol / g, a terminal amino group concentration [NH ₂ ] of 56 μmol / g, and a terminal carboxyl group concentration [COOH] of 220 μmol / g. The molar ratio was 0.69. The hue of the sample after heat treatment at 170 ° C. 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. When a test piece was prepared by injection molding using the obtained polyamide resin, there was no sink mark due to poor filling, silvery traces due to generation of moisture, gas, etc., contamination of koge or gel, and hue such as yellowing Thus, a test piece of polyamide resin having a good appearance and hue was obtained.

(Example 8)
The amount of raw materials charged was terephthalic acid 179.45 g (1.080 mol), 1,10-diaminodecane 170.52 g (0.990 mol = 90 mol%), 1,12-diaminododecane 22.03 g (0.003 mol). 110 mol = 10 mol%), 3.96 g (0.032 mol) of benzoic acid, except that the temperature of solid phase polymerization was 240 ° C. and the reaction time was 6 hours, A polyamide resin having a high degree of polymerization was obtained.

The obtained polyamide had an IV of 1.40, a melting point by DSC measurement of 309 ° C., and a crystallization temperature of 279 ° C. The hues were L ^* = 99.6 and YI = 6.5, and a polyamide resin having a sufficiently high degree of polymerization and a sufficiently high hue was obtained. The obtained polyamide resin has a phosphorus compound concentration of 37 μmol / g, a terminal amino group concentration [NH ₂ ] of 52 μmol / g, and a terminal carboxyl group concentration [COOH] of 18 μmol / g. The molar ratio of was 0.71. The hue of the sample after heat treatment at 170 ° C. for 8 hours in a heating oven was L ^* = 96.8 and YI = 17.5, and the brightness and yellowness of the sample were good. When a test piece was prepared by injection molding using the obtained polyamide resin, there was no sink mark due to poor filling, silvery traces due to generation of moisture, gas, etc., contamination of koge or gel, and hue such as yellowing Thus, a test piece of polyamide resin having a good appearance and hue without any abnormalities was obtained.

(Comparative Example 1)
The amount of raw materials charged was 180.64 g (1.087 mol) of terephthalic acid, 169.46 g (0.983 mol = 90 mol%) of 1,10-diaminodecane, 21.89 g (0. 89 g) of 1,12-diaminododecane. 109 mol = 10 mol%), 3.98 g (0.033 mol) of benzoic acid, 0.376 g (3.55 mmol, sodium hypophosphite monohydrate (SHM), 0.1 part by weight based on the charged raw materials Except for the above, a highly polymerized polyamide resin was obtained in the same manner as in Example 1.

The obtained polyamide resin had an IV of 1.02, a melting point by DSC measurement of 309 ° C., and a crystallization temperature of 280 ° C. The hue was L ^* = 100.3 and YI = 5.5, and a polyamide resin having a good hue with a sufficiently high degree of polymerization was obtained. The obtained polyamide resin had a phosphorus compound concentration of 9 μmol / g, a terminal amino group concentration [NH ₂ ] of 55 μmol / g, and a terminal carboxyl group concentration [COOH] of 76 μmol / g. The molar ratio of was 0.17. The hue of the sample after heat treatment at 170 ° C. for 8 hours in a heating oven was L ^* = 96.4, YI = 19.3, and the brightness and yellowness of the sample were inferior.

(Comparative Example 2)
The amount of raw materials charged was terephthalic acid 179.27 g (1.079 mol), 1,10-diaminodecane 170.68 g (0.991 mol = 90 mol%), 1,12-diaminododecane 22.05 g (0. 110 mol = 10 mol%), benzoic acid 3.95 g (0.032 mol), sodium hypophosphite monohydrate (SHM) 0.752 g (7.09 mmol, 0.2 parts by weight based on the charged raw materials) Except for the above, a highly polymerized polyamide resin was obtained in the same manner as in Example 1.

The obtained polyamide resin had an IV of 1.04, a melting point measured by DSC of 309 ° C., and a crystallization temperature of 281 ° C. The hue was L ^* = 100.1 and YI = 5.6, and a polyamide resin having a good hue with a sufficiently high degree of polymerization was obtained. The obtained polyamide resin has a phosphorus compound concentration of 18 μmol / g, a terminal amino group concentration [NH ₂ ] of 80 μmol / g, and a terminal carboxyl group concentration [COOH] of 53 μmol / g. The molar ratio was 0.24. The hue of the sample after heat treatment at 170 ° C. for 8 hours in a heating oven was L ^* = 96.2 and YI = 20.8, and the brightness and yellowness of the sample were inferior.

(Comparative Example 3)
The amount of raw materials charged was 181.39 g (1.092 mol) of terephthalic acid, 168.80 g of 1,10-diaminodecane (0.980 mol = 90 mol%), 21.81 g of 1,12-diaminododecane (0. 109 mol = 10 mol%), 4.00 g (0.033 mol) of benzoic acid, 0.376 g (3.55 mmol, sodium hypophosphite monohydrate (SHM), 0.1 part by weight based on the charged raw materials In the same manner as in Example 1 except that the solid-state polymerization temperature was 245 ° C., a highly polymerized polyamide resin was obtained.

The obtained polyamide resin had an IV of 0.86, a melting point measured by DSC of 310 ° C., and a crystallization temperature of 282 ° C. The hue was L ^* = 99.1, YI = 6.4, and a polyamide resin with a high degree of polymerization was obtained. The obtained polyamide resin had a phosphorus compound concentration of 9 μmol / g, a terminal amino group concentration [NH ₂ ] of 25 μmol / g, and a terminal carboxyl group concentration [COOH] of 82 μmol / g. The molar ratio of was 0.38. The hue of the sample after heat treatment at 170 ° C. 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)
A polyamide resin having a high degree of polymerization was obtained in the same manner as in Example 3 except that the time for solid phase polymerization was 7 hours.

The obtained polyamide resin had an IV of 1.12, a melting point of 310 ° C. as measured by DSC, and a crystallization temperature of 276 ° C. The hues were L ^* = 100.2 and YI = 5.6, and a polyamide resin with a high degree of polymerization was obtained. The obtained polyamide resin had a phosphorus compound concentration of 38 μmol / g, a terminal amino group concentration [NH ₂ ] of 32 μmol / g, and a terminal carboxyl group concentration [COOH] of 51 μmol / g. The molar ratio of was 1.18. The hue of the sample after heat treatment at 170 ° C. for 8 hours in a heating oven was L ^* = 96.1 and YI = 20.0, and the brightness and yellowness of the sample were inferior. When a test piece was produced by injection molding using the obtained polyamide resin, a silver-like mark was generated on the surface of the molded piece, resulting in a test piece inferior in appearance.

(Comparative Example 5)
In the same manner as in Example 1, except that the amount of sodium hypophosphite monohydrate (SHM) charged was 3.760 g (35.47 mmol, 1.0 part by weight based on the charged raw materials), A polyamide resin having a high degree of polymerization was obtained.

The obtained polyamide resin had an IV of 1.42, a melting point measured by DSC of 307 ° C., and a crystallization temperature of 272 ° C. The hue was L ^* = 99.4, YI = 9.5, the polyamide resin was abnormally thickened, properties such as the melting point were slightly lowered, and the hue was slightly deteriorated. The obtained polyamide resin had a phosphorus compound concentration of 94 μmol / g, a terminal amino group concentration [NH ₂ ] of 39 μmol / g, and a terminal carboxyl group concentration [COOH] of 29 μmol / g. The molar ratio of was 2.39. The hue of the sample after heat treatment at 170 ° C. for 8 hours in a heating oven was L ^* = 95.3 and YI = 18.5, and the brightness and yellowness of the sample were inferior. Attempts were made to injection-mold the obtained polyamide resin, but it was unable to obtain a molded piece because of abnormal thickening and gelation in the molding machine.

(Comparative Example 6)
In the same manner as in Example 5, except that the amount of sodium hypophosphite monohydrate (SHM) charged was 0.372 g (3.51 mmol, 0.1 part by weight based on the charged raw material), A polyamide resin having a high degree of polymerization was obtained.

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

(Comparative Example 7)
The amount of sodium hypophosphite monohydrate (SHM) charged was 0.372 g (3.51 mmol, 0.1 part by weight with respect to the charged raw material), and the solid-state polymerization time was 6 hours. In the same manner as in Example 4, a highly polymerized polyamide resin was obtained.

The obtained polyamide resin had an IV of 0.92, a melting point measured by DSC of 298 ° C., and a crystallization temperature of 267 ° C. The hues were L ^* = 100.4 and YI = 3.7, and a highly polymerized polyamide resin was obtained. The obtained polyamide resin had a phosphorus compound concentration of 9 μmol / g, a terminal amino group concentration [NH ₂ ] of 25 μmol / g, and a terminal carboxyl group concentration [COOH] of 87 μmol / g. The molar ratio was 0.38. The hue 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 brightness and yellowness of the sample were inferior.

(Comparative Example 8)
The amount of raw materials charged was 167.72 g (1.009 mol) of terephthalic acid, 204.28 g (1.020 mol) of 1,12-diaminododecane, 3.70 g (0.030 mol) of benzoic acid, and solid phase polymerization. A polyamide resin with a high degree of polymerization was obtained in the same manner as in Example 5 except that the time was set to 7 hours.

The obtained polyamide resin had an IV of 1.08, a melting point measured by DSC of 297 ° C., and a crystallization temperature of 268 ° C. The hues were L ^* = 100.1 and YI = 3.3, and a highly polymerized polyamide resin was obtained. The obtained polyamide resin has a phosphorus compound concentration of 38 μmol / g, a terminal amino group concentration [NH ₂ ] of 34 μmol / g, and a terminal carboxyl group concentration [COOH] of 57 μmol / g. The molar ratio of was 1.10. The hue of the sample after heat treatment at 170 ° C. for 8 hours in a heating oven was L ^* = 97.7 and YI = 16.3, and the brightness and yellowness of the sample were inferior. When a test piece was produced by injection molding using the obtained polyamide resin, a silver-like mark was generated on the surface of the molded piece, resulting in a test piece inferior in appearance.

  The evaluation results of the above Examples and Comparative Examples are summarized and shown in Tables 2 and 3 below.

  As apparent from Tables 2 and 3 above, it was found that the polyamide resins of the present invention obtained in Examples 1 to 8 were excellent in heat resistant hue. 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 resistant hue.

Claims (4)

A polyamide resin obtained by a polycondensation reaction between a dicarboxylic acid compound consisting only of terephthalic acid and a diamine compound consisting only of 1,12-diaminododecane or consisting of only 1,10-diaminodecane and 1,12-diaminododecane. The ratio of the concentration (unit: μmol / g) of the phosphorus compound contained in the polyamide resin to the terminal amino group concentration (unit: μmol / g) of the polyamide resin (concentration of phosphorus compound / terminal amino group concentration). ) Is 0.5 to 1.0. The polyamide resin according to claim 1, wherein the diamine compound comprises only 1,12-diaminododecane.   The phosphorous compound is at least one selected from the group consisting of hypophosphite, phosphite, phosphate, hypophosphorous acid, phosphorous acid, and phosphoric acid. The polyamide resin described in 1. A polycondensation reaction between a dicarboxylic acid compound consisting only of terephthalic acid and a diamine compound consisting only of 1,12-diaminododecane or consisting of only 1,10-diaminodecane and 1,12-diaminododecane in the presence of a phosphorus compound And a step of producing a low-order condensate,
Discharging and cooling the low-order condensate;
Solid-phase polymerization of the cooled low-order condensate;
The manufacturing method of the polyamide resin of any one of Claims 1-3 containing this.