JP3720184B2 - Process for producing a polyamide resin composition having excellent molding characteristics - Google Patents

Description

【００６１】
【表２】

【００６２】
表１、２の注釈は次の通りである。
Ｎ６６：ナイロン６６
Ｎ６：ナイロン６
Ｎ６６／６Ｉ：ナイロン６６とナイロン６Ｉの共重合物
ＳＴ−Ｃａ：ステアリン酸カルシウム
ＳＴ−Ａｌ：ステアリン酸モノアルミニウム
ＳＴ−ＳＴ：ステアリルステアレート
Ｂｅ−Ｂｅ：ベヘニルベヘネート
ＳＴ−Ａ：ステアリン酸アミド
ＥＲ−Ａ：エルカ酸アミド
リン＊ａ）：次亜リン酸ナトリウム
銅＊ｂ）：ヨウ化銅＋ヨウ化カリウム
【００６３】
【発明の効果】
本発明のポリアミド樹脂組成物は、射出成形における幅広い成形条件での離型性能および可塑化性能に優れるため、成形サイクルを短縮することができ、また成形品外観品質にも優れる。さらに、本発明のポリアミド樹脂組成物は、高い生産性で製造することができる。
【図面の簡単な説明】
【図１】本発明で離型特性の測定に用いた金型の図である。
【符号の説明】
１ スプルランナー
２ カップ状成形品
３ エジェクターピン
４ エジェクタープレート
５ ロードセル
６ エジェクターロッド[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a polyamide resin composition for molding, and particularly relates to a polyamide resin composition excellent in processability such as mold release property and plasticization property under a wide range of injection molding conditions.
[0002]
[Prior art]
Polyamide resins, particularly nylon 66 resins, are widely used in applications such as connectors and binding bands because of their excellent mechanical properties. In recent years, the shape of molded products has become increasingly complex, and production has been performed under a wide range of molding conditions.
For example, there is an example in which molding is performed at a melting temperature exceeding 300 ° C., or molding is performed even at a mold temperature that is lower than room temperature by a mold temperature controller. In order to meet these molding conditions and increase productivity, it is one of the important means to improve the releasability of the molded product from the mold in injection molding and to shorten the plasticization time. is there.
[0003]
In order to improve the releasability, a method of adding various release lubricants to the polyamide resin pellets is generally performed. Examples of the release lubricant for improving the releasability of polyamide include an example of adding a higher fatty acid, an example of adding a bisamide, an example of adding a metal salt of a higher fatty acid, and an example of adding a higher fatty acid ester.
However, the use of these lubricants alone improves the mold releasability in a specific narrow temperature range and covers a wide range of mold temperature releasability in various molding from low mold temperature to high mold temperature. It is difficult to do.
[0004]
JP-A-7-228770 discloses an example in which a combination of a higher fatty acid metal salt and a higher fatty acid ester is adhered to the pellet surface. By combining these lubricants, the releasability is improved compared to the case of using a single lubricant, but the method of attaching the lubricant to the pellet surface as in this example has adverse effects such as uneven surface adhesion and separation due to dropping. Variations in mold performance are likely to occur, and the plasticization time during injection molding is particularly long in molding at high temperature melting, resulting in problems such as reduced productivity.
[0005]
In order to solve these problems, it is effective to include a lubricant in the polyamide resin. As shown in the examples of JP-B-6-19016 and JP-A-9-235464, an extruder is used. The method of kneading the additive into the pellet and adding the additive to the inside of the pellet can solve the problem of variation in mold release performance and high temperature plasticity to some extent. To increase the energy cost and productivity by increasing the number of new processes, the polymer receives extra heat due to re-melting in the extruder, and the color tone deteriorates due to deterioration. There's a problem.
[0006]
As mentioned above, in order to improve the mold release property in a wide range of mold temperatures from low mold temperature to high mold temperature, it is difficult to cope with a single mold release lubricant, and multiple lubricants are combined. Only then can the desired release performance be obtained.
At this time, when a combination lubricant such as a higher fatty acid metal salt or a higher fatty acid esterified product is added to the polyamide pellet, it is 290 ° C. or more in the case of nylon 66 when it is added to the surface of the pellet as usual. Under the conditions of molding at a high cylinder temperature, the plasticization time is extremely prolonged, and the productivity is lowered. This is because when the lubricant is adhered to the pellet surface, the lubricant on the surface of the pellet supplied into the high-temperature cylinder in the molding melts to cause the fusion of the pellets. It is thought to prevent the movement. Furthermore, in the method in which a powdery lubricant is applied to the surface of the pellet by blending or coating, uneven adhesion or dropping of the lubricant cannot be avoided, and as a result, variations in molding performance such as mold release tend to occur.
[0007]
Once the polymerized polymer is pelletized, the method of kneading and containing the lubricant inside the pellet using an extruder or the like eliminates the above-mentioned adverse effects on plasticizing properties and variations in addition of the lubricant to some extent, but a new extrusion process Is required, which is disadvantageous in terms of productivity and energy cost, and causes serious problems of deterioration coloring in the remelting process of the polymer.
[0008]
[Problems to be solved by the invention]
The present invention is a polyamide resin which is improved in mold release property at a wide range of mold temperatures to eliminate variation, and has excellent plasticizing properties so as to meet the recent needs for improving the molding performance of polyamide resins. The object is to provide a composition with high productivity.
[0009]
[Technical means for solving the problems]
As a result of intensive studies, the present inventors have found that the above-mentioned problems can be solved by adding a higher fatty acid metal salt, a higher fatty acid esterified product and a higher fatty acid amide as a lubricant to the polyamide by melt addition during the polymerization of the polyamide. The present invention has been made.
[0010]
That is, the present invention is as follows.
1) In the polyamide melt polymerization step, when polycondensation proceeds and the water content in the polyamide becomes 10% by weight or less, a melt of 0.01 to 1 of a metal salt of a higher fatty acid with respect to 100 parts by weight of the polyamide. 0.0 part by weight, 0.01 to 1.0 part by weight of a melt of an esterified product of a higher fatty acid and a higher alcohol and 0.01 to 1.0 part by weight of a melt of a higher fatty acid amide are added to the molten polyamide. preparation of a polyamide resin composition characterized Rukoto dispersed Te.
[0011]
2 ) A melt of a higher fatty acid metal salt, a melt of an esterified product of a higher fatty acid and a higher alcohol, and a melt of a higher fatty acid amide are a metal salt of a higher fatty acid, an esterified product of a higher fatty acid and a higher alcohol, and a higher fatty acid. a mixture of the amide, the preparation of the polyamide resin composition of the 1 Symbol placement, characterized in that a mixture melt obtained by heating melt at a temperature above the melting point of the mixture.
3) The manufacturing method of the polyamide resin composition of said 1 or 2 whose higher fatty acid amide is saturated fatty acid amide .
[0012]
4) The method for producing a polyamide resin composition according to any one of the above 1 to 3, wherein batch polymerization is used.
5) The process for producing a polyamide resin composition as described in any one of 1 to 3 above, wherein continuous polymerization is used .
[0013]
Hereinafter, the present invention will be described in detail.
Known polyamides can be used as the polyamide applied to the present invention. For example, various types of polyamide resins such as lactam polycondensate, polycondensate of diamine compound and dicarboxylic acid compound, and polycondensate of ω-aminocarboxylic acid, such as nylon 6, 66, 610, 6I, 6T, etc. In addition, for example, nylon 66/6, 66/610, 66 / 6I, 66 / 6T and the like, and their mutual blends can be cited as the copolymerized polyamide resin.
[0014]
The method for producing these polyamides may be a commonly used melt polymerization method for polyamides, and may be batch polymerization or continuous polymerization.
In the present invention, at the stage where polycondensation proceeds and the water content in the polyamide becomes 10% by weight or less in the polyamide melt polymerization step, a metal salt of a higher fatty acid, an ester of a higher fatty acid and a higher alcohol is added to the polyamide. Compound and higher fatty acid amide are added and dispersed in the molten polyamide.
[0015]
As a metal salt of a higher fatty acid, a metal salt of a higher aliphatic carboxylic acid having 10 to 30 carbon atoms is preferable. Specific examples include calcium salts such as palmitic acid, stearic acid, and montanic acid, and aluminum salts. Preferred examples include calcium stearate and aluminum stearate.
The esterified product of a higher fatty acid and a higher alcohol is preferably an esterified product of a higher aliphatic carboxylic acid having 10 to 30 carbon atoms and a higher alcohol having 10 to 30 carbon atoms. Specifically, higher aliphatic carboxylic acids include lauric acid, stearic acid, behenic acid and the like, and higher alcohols include lauryl alcohol, stearyl alcohol, behenyl alcohol, and the like, and esters of combinations of these fatty acids and alcohols. Is used. Preferably, stearyl stearate which is an ester of stearic acid and stearyl alcohol, behenyl behenate which is an ester of behenic acid and behenyl alcohol, and the like can be mentioned.
[0016]
As the higher fatty acid amide, a higher aliphatic carboxylic acid amide compound having 10 to 30 carbon atoms is preferable. Specific examples include stearic acid amide, behenic acid amide, erucic acid amide, and oleic acid amide. Of these, saturated fatty acid amides such as stearic acid amide and behenic acid amide are preferable because coloring is unlikely to occur.
[0017]
By combining the above three types of additives (hereinafter referred to as “lubricants”), good releasability can be obtained in a wide mold temperature range from a target low mold temperature to a high mold temperature. If necessary, four or more of these three types of lubricants can be used in combination.
The above three types of lubricants are each added in an amount of 0.01 to 1.0 part by weight with respect to 100 parts by weight of polyamide. In any case, when the added amount is less than 0.01 parts by weight, sufficient release effect is not exhibited. When the added amount is more than 1.0 parts by weight, the viscosity of the molded product is lowered or silver is easily generated. . Preferably, all are in the range of 0.03 to 0.5 parts by weight.
[0018]
Each of the above lubricants may be added as a melt, or may be added as a mixed melt. When mixed and added, two types of combinations of higher fatty acid metal salts and esterified products of higher fatty acids and higher alcohols may be used, but it is better to add three types of mixed systems by adding higher fatty acid amides. The effect of lowering enables melting at a low temperature, which is very advantageous in terms of heating energy cost during production. More surprisingly, the combination of higher fatty acid amides achieves the unexpected effect of improving the transparency of the molded product and obtaining an excellent product.
[0019]
The above-mentioned lubricant is heated to a temperature not lower than its melting point and not higher than 400 ° C. to obtain a melt, and this is injected and added into the molten polyamide in the polyamide polymerization step. The melting temperature is preferably as low as possible in order to prevent decomposition of the lubricant. The temperature is preferably the melting point or higher and the melting point plus 100 ° C. or lower, more preferably the melting point or higher and the melting point plus 50 ° C. or lower.
[0020]
For the injection addition, for example, a feed pump such as a gear pump or a plunger pump is used to perform the side injection addition of the melt into the molten polyamide in the polymerization line.
Usually, when polyamide is polymerized from a raw material nylon salt aqueous solution, since there is a lot of moisture in the initial stage of the polymerization, the addition of the above-mentioned lubricant to this step separates the salt and oligomer aqueous solution from the lubricant. Therefore, it is necessary to inject and add a lubricant when the polycondensation proceeds and the moisture in the polyamide becomes 10% or less. It is preferable to add it when the water content in the polymer is 1% or less.
[0021]
By heating and melting the lubricant into a liquid melt, the polyamide and the lubricant are uniformly mixed. In addition, by using the above feed pump, the addition accuracy is remarkably increased compared to the case of adhering to the polyamide pellet surface or mixing and kneading the pellet and lubricant with an extruder. A uniform resin composition having excellent molding performance and stable quality with no variation can be obtained.
[0022]
In addition, the resin composition of the present invention includes a polymerization catalyst such as a phosphorus compound such as hypophosphite, phosphite, and phenylphosphonate, and a copper compound such as copper acetate and copper iodide, if necessary. In addition, a known substance such as a heat stabilizer such as talc, a filler such as talc, and a reinforcing material such as glass fiber can be contained.
In addition, if necessary, a conventional lubricant such as a higher fatty acid metal salt can be further added and adhered to the pellet surface.
[0023]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be specifically described with reference to Examples and Comparative Examples.
The evaluation method is as follows.
(1) Evaluation method of mold release performance As shown in Fig. 1, molding is performed under the following molding conditions using a mold with a release force measuring device with a load cell installed on the protruding pin (ejector pin) of the molded product. The average value and the variation were calculated from the measured values of the 50-shot mold release force. The variation was determined as the difference between the maximum value and the minimum value of the measured release force.
[0024]
Injection molding machine: IS-90B manufactured by Toshiba Machine Co., Ltd.
Mold: Cup shaped cylinder temperature setting: 280 ° C
Mold temperature: 100 ° C for high mold temperature evaluation, 30 ° C for low mold temperature evaluation
Injection pressure: 400kg / cm2
Injection speed: 30%
Injection time: 7 seconds Cooling time: 20 seconds (2) Plasticizing performance evaluation method Except for the following conditions, molding is performed in the same manner as the above-described mold release performance evaluation, and the time required for the screw to retract during plasticization is determined. The average value of the plasticization time of 50 shots was determined.
[0025]
Cylinder temperature setting: 320 ° C
Mold temperature: 100 ° C
(3) Evaluation Method of Molded Product Color Tone The color tone of the molded product molded by the above-described mold release evaluation (mold temperature 100 ° C.) was measured.
Using ND-300A manufactured by Nippon Denshoku Co., Ltd. as a colorimeter, the L, a, and b values of the bottom surface of the molded product were measured by reflection measurement, and the yellowness was evaluated by the b value.
[0026]
The b value is an absolute value + and a larger value indicates that the color tone is yellow.
(4) Evaluation Method of Transparency of Molded Product The transparency of the molded product subjected to the color tone evaluation was evaluated.
The bottom of the molded product cup was brought into close contact with a general printed material such as a newspaper or magazine, and the evaluation was made based on whether the characters on the printed material could be read through the molded product.
[0027]
○: Characters can be read through the molded product.
Δ: It can be seen that characters are written, but cannot be read.
X: It is not clear that the characters are opaque and written.
[0028]
[Example 1]
As a lubricant, a mixed lubricant in which calcium stearate, stearyl stearate (esterified product of stearic acid and stearyl alcohol) and stearamide were mixed in the same weight was prepared. The melting point of this mixed lubricant was 120 ° C. This mixed lubricant was heated to 140 ° C. to prepare a uniform melt.
[0029]
This melt was injected and added in the continuous polymerization process of nylon 66.
First, a 50% aqueous solution of an AH salt composed of adipic acid and hexamethylenediamine (hereinafter simply referred to as AH salt) is pre-concentrated to 80%, heated to 250 ° C. in a polymerization tank, and pressurized to 17 atm. The condensed water was removed while prepolymerization was performed. Thereafter, the pressure is reduced to atmospheric pressure and the mixture is heated to 280 ° C., and further, condensed water is removed to complete the polycondensation, and sulfuric acid relative viscosity (1 g / 100 cc-98% sulfuric acid, 25 ° C.) ηr = 2.8 A nylon 66 polymer was obtained. The moisture content in the polymer at this stage was 1% or less.
[0030]
Into this nylon 66 molten polymer discharge line, a heated and melted lubricant liquid is injected and added in an amount of 0.3 part by weight with respect to 100 parts by weight of the polymer using a plunger pump, and this is formed into a strand. After cutting, it was dried to prepare nylon 66 resin pellets containing a lubricant.
The obtained pellets were subjected to injection molding to evaluate moldability of mold release property and plasticizing property, and to evaluate quality of molded product color tone and transparency. Table 1 shows the results.
[0031]
[Example 2]
As a lubricant, a mixed lubricant in which monoaluminum stearate, stearyl stearate and stearamide were mixed at the same weight was prepared. The melting point of this mixed lubricant was 120 ° C. This mixed lubricant was heated to 140 ° C. to prepare a uniform melt.
[0032]
In the same manner as in Example 1, a nylon 66 resin pellet containing a lubricant was prepared by injecting and adding 0.3 parts by weight to 100 parts by weight of the polymer in the nylon 66 polymer polymerization step.
In the same manner as in Example 1 using the obtained pellets, evaluation of moldability of mold release property and plasticizing property and quality evaluation of molded product color tone / transparency were performed by injection molding, and the results are shown in Table 1. Indicated.
[0033]
[Example 3]
As a lubricant, a mixed lubricant was prepared in which calcium stearate, behenyl behenate (esterified product of behenic acid and behenyl alcohol) and stearamide were mixed in the same weight. The melting point of this mixed lubricant was 130 ° C. This mixed lubricant was heated to 150 ° C. to prepare a uniform melt.
[0034]
In the same manner as in Example 1, a nylon 66 resin pellet containing a lubricant was prepared by injecting and adding 0.3 parts by weight to 100 parts by weight of the polymer in the nylon 66 polymer polymerization step.
In the same manner as in Example 1 using the obtained pellets, evaluation of moldability of mold release property and plasticizing property and quality evaluation of molded product color tone / transparency were performed by injection molding, and the results are shown in Table 1. Indicated.
[0035]
[Example 4]
As a lubricant, a mixed lubricant was prepared by mixing calcium stearate, stearyl stearate, and erucic acid amide at the same weight. The melting point of this mixed lubricant was 100 ° C. This mixed lubricant was heated to 120 ° C. to prepare a uniform melt.
In the same manner as in Example 1, a nylon 66 resin pellet containing a lubricant was prepared by injecting and adding 0.3 parts by weight to 100 parts by weight of the polymer in the nylon 66 polymer polymerization step.
[0036]
In the same manner as in Example 1 using the obtained pellets, evaluation of moldability of mold release property and plasticizing property and quality evaluation of molded product color tone / transparency were performed by injection molding, and the results are shown in Table 1. Indicated.
[0037]
[Example 5]
Nylon 66 resin pellets were prepared in the same manner as in Example 1 except that sodium hypophosphite was added to the AH salt 50% aqueous solution so as to be 100 ppm based on the weight of the produced polymer.
In the same manner as in Example 1 using the obtained pellets, evaluation of moldability of mold release property and plasticizing property and quality evaluation of molded product color tone / transparency were performed by injection molding, and the results are shown in Table 1. Indicated.
[0038]
[Example 6]
Nylon in the same manner as in Example 1, except that copper iodide and potassium iodide were added to the AH salt 50% aqueous solution so as to be 0.03% and 0.5%, respectively, with respect to the weight of the produced polymer. 66 resin pellets were made.
In the same manner as in Example 1 using the obtained pellets, evaluation of moldability of mold release property and plasticizing property and quality evaluation of molded product color tone / transparency were performed by injection molding, and the results are shown in Table 1. Indicated.
[0039]
[Comparative Example 1]
Polymerization alone was carried out in the same manner as in Example 1, and 100 parts by weight of nylon 66 resin pellets to which no lubricant was added, 0.1 parts by weight of calcium stearate, 0.1 parts by weight of stearyl stearate as a lubricant, and Stearic acid amide was mixed at a ratio of 0.1 part by weight and blended with a cone-type blender to prepare nylon 66 resin pellets having a lubricant attached to the pellet surface.
[0040]
In the same manner as in Example 1 using the obtained pellets, evaluation of moldability of mold release property and plasticizing property and quality evaluation of molded product color tone / transparency were performed by injection molding, and the results are shown in Table 1. Indicated.
[0041]
[Comparative Example 2]
Polymerization alone was carried out in the same manner as in Example 1, and 100 parts by weight of nylon 66 resin pellets to which no lubricant was added, 0.1 parts by weight of calcium stearate, 0.1 parts by weight of stearyl stearate as a lubricant, and Stearic acid amide is mixed at a ratio of 0.1 part by weight, heated to 280 ° C. with an extruder (manufactured by Toshiba Machine Co., Ltd .; TEM35), remelted and kneaded at a discharge rate of 50 kg / hr, and obtained. Nylon 66 resin pellets containing a lubricant were prepared by cutting the polymer strands.
[0042]
In the same manner as in Example 1 using the obtained pellets, evaluation of moldability of mold release property and plasticizing property and quality evaluation of molded product color tone / transparency were performed by injection molding, and the results are shown in Table 1. Indicated.
[0043]
[Comparative Example 3]
As a lubricant, a mixed lubricant was prepared by mixing calcium stearate and stearyl stearate in the same weight. The melting point of this mixed lubricant was 160 ° C. This mixed lubricant was heated to 180 ° C. to prepare a uniform melt.
In the same manner as in Example 1, a nylon 66 resin pellet containing a lubricant was prepared by injecting and adding 0.2 parts by weight to 100 parts by weight of the polymer in the nylon 66 polymer polymerization step.
[0044]
In the same manner as in Example 1 using the obtained pellets, evaluation of moldability of mold release property and plasticizing property and quality evaluation of molded product color tone / transparency were performed by injection molding, and the results are shown in Table 1. Indicated.
[0045]
[Comparative Example 4]
In accordance with Comparative Example 1, 100 parts by weight of nylon 66 pellets were mixed with 0.1 parts by weight of stearyl stearate and 0.1 parts by weight of stearamide as a lubricant, and blended with a cone-type blender. A nylon 66 resin pellet having a lubricant attached to the pellet surface was prepared.
[0046]
In the same manner as in Example 1 using the obtained pellets, evaluation of moldability of mold release property and plasticizing property and quality evaluation of molded product color tone / transparency were performed by injection molding, and the results are shown in Table 1. Indicated.
[0047]
[Comparative Example 5]
In accordance with Comparative Example 1, 100 parts by weight of nylon 66 pellets were mixed with only 0.3 parts by weight of calcium stearate as a lubricant, blended with a cone type blender, and the lubricant was adhered to the pellet surface. 66 resin pellets were made.
[0048]
In the same manner as in Example 1 using the obtained pellets, evaluation of moldability of mold release property and plasticizing property and quality evaluation of molded product color tone / transparency were performed by injection molding, and the results are shown in Table 1. Indicated.
[0049]
[Example 7]
A mixed lubricant in which calcium stearate, stearyl stearate and stearamide were mixed in the same weight as a lubricant was prepared, and the mixed lubricant was heated to 140 ° C. to prepare a uniform melt.
This melt was injected and added in the continuous polymerization process of nylon 6.
[0050]
First, ε-caprolactam was melted with a melter, water and a polymerization degree adjusting agent were added, heated to 260 ° C. in a normal pressure polymerization tower, reacted for 10 hours, and then a sulfuric acid relative viscosity ηr = 2.4. Nylon 6 polymer was obtained.
The moisture content in the polymer at this stage was 1% or less.
In the nylon 6 melt polymer discharge line, a heat-dissolved lubricant solution is injected and added in an amount of 0.3 part by weight with respect to 100 parts by weight of the polymer using a plunger pump. The pellets thus obtained were treated with hot water to extract and remove unreacted oligomers and then dried to prepare nylon 6 resin pellets containing a lubricant therein.
[0051]
Using the obtained pellets, injection molding was carried out in the same manner as in Example 1 except for the following conditions, evaluation of moldability of mold release and plasticizing properties, quality evaluation of molded product color tone and transparency, The results are shown in Table 2.
Cylinder temperature setting: 290 ° C
Injection time: 15 seconds Cooling time: 40 seconds
[Comparative Example 6]
Polymerization was carried out in the same manner as in Example 7, and 100 parts by weight of nylon 6 resin pellets to which no lubricant was added were mixed with 0.3 parts by weight of calcium stearate as a lubricant, and blended with a cone-type blender. Thus, nylon 6 resin pellets having a lubricant adhered to the pellet surface were prepared.
[0053]
In the same manner as in Example 7 using the obtained pellets, evaluation of moldability of mold release property and plasticizing property, quality evaluation of molded product color tone and transparency were performed by injection molding, and the results are shown in Table 2. Indicated.
[0054]
[Example 8]
As a lubricant, a mixed lubricant in which calcium stearate, stearyl stearate and stearamide were mixed in the same amount was prepared, and the mixed lubricant was heated to 140 ° C. to prepare a uniform melt.
This melt was injected and added in a batch polymerization process of nylon 66 / 6I.
[0055]
First, 5 parts by weight of hexamethylene diamine and 7 parts by weight of isophthalic acid are mixed with 100 parts by weight of a 50% aqueous solution of an AH salt composed of adipic acid and hexamethylene diamine, pre-concentrated to 80%, and then polymerized. In a tank, it was heated to 250 ° C., and condensed water was removed while pressurizing to 17 atm to make a prepolymer. Thereafter, the pressure is reduced to atmospheric pressure and the mixture is heated to 280 ° C., and the condensed water is removed to complete the polycondensation. The ratio of nylon 66 to nylon 6I is 8: 2, and the relative viscosity of sulfuric acid ηr = 2.3. Nylon 66 / 6I copolymer was obtained. The moisture content in the polymer at this stage was 1% or less.
[0056]
To the molten polymer discharge line, the heated and melted lubricant liquid was injected and added in an amount of 0.3 part by weight with respect to 100 parts by weight of the polymer using a plunger pump, and this was formed into a strand and cut. It dried and the nylon 66 / 6I copolymer resin pellet which contained the lubricant inside was produced.
Using the obtained pellets, injection molding was performed in the same manner as in Example 1 except for the following conditions, evaluation of moldability of mold release property and plasticizing property, quality evaluation of molded product color tone and transparency, The results are shown in Table 2.
[0057]
Cylinder temperature setting: 290 ° C
Injection time: 20 seconds Cooling time: 60 seconds
[Comparative Example 7]
Polymerization was carried out in the same manner as in Example 8, and 100 parts by weight of nylon 66 / 6I copolymer resin pellets to which no lubricant was added were mixed with 0.3 parts by weight of calcium stearate as a lubricant. Blending with a mold blender produced pellets with a lubricant attached to the pellet surface.
[0059]
In the same manner as in Example 8, using the obtained pellets, evaluation of moldability of mold release property and plasticizing property and quality evaluation of molded product color tone / transparency were performed by injection molding, and the results are shown in Table 2. Indicated.
[0060]
[Table 1]

[0061]
[Table 2]

[0062]
The annotations in Tables 1 and 2 are as follows.
N66: Nylon 66
N6: Nylon 6
N66 / 6I: Nylon 66 and nylon 6I copolymer ST-Ca: calcium stearate ST-Al: monoaluminum stearate ST-ST: stearyl stearate Be-Be: behenyl behenate ST-A: stearamide ER -A: Amidophosphorus erucate * a): Sodium copper hypophosphite * b): Copper iodide + Potassium iodide
【The invention's effect】
Since the polyamide resin composition of the present invention is excellent in mold release performance and plasticizing performance under a wide range of molding conditions in injection molding, the molding cycle can be shortened and the molded product appearance quality is also excellent. Furthermore, the polyamide resin composition of the present invention can be produced with high productivity.
[Brief description of the drawings]
FIG. 1 is a diagram of a mold used for measurement of mold release characteristics in the present invention.
[Explanation of symbols]
1 sprue runner 2 cup-shaped product 3 ejector pin 4 ejector plate 5 load cell 6 ejector rod

Claims (5)

In the polyamide melt polymerization step, when polycondensation proceeds and the water content in the polyamide becomes 10% by weight or less, the molten metal salt of higher fatty acid 0.01 to 1.0 parts per 100 parts by weight of polyamide. Part by weight, 0.01 to 1.0 part by weight of a melt of an esterified product of a higher fatty acid and a higher alcohol and 0.01 to 1.0 part by weight of a melt of a higher fatty acid amide are added and dispersed in the molten polyamide. preparation of a polyamide resin composition characterized Rukoto is. A melt of a higher fatty acid metal salt, a melt of an esterified product of a higher fatty acid and a higher alcohol, and a melt of a higher fatty acid amide are used. the mixture preparation of the polyamide resin composition according to claim 1 Symbol mounting, characterized in that a mixture melt obtained by heating melt at a temperature above the melting point of the mixture. The process for producing a polyamide resin composition according to claim 1 or 2, wherein the higher fatty acid amide is a saturated fatty acid amide. Batch-type polymerization is used, The manufacturing method of the polyamide resin composition of any one of Claims 1-3 characterized by the above-mentioned. The method for producing a polyamide resin composition according to any one of claims 1 to 3, wherein continuous polymerization is used .

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