JPH08197601A - Melt molded piece made of copolymeric polyamide and manufacture thereof - Google Patents

Abstract

PURPOSE: To obtain a molded piece of high quality having excellent appearance and mechanical property by specifying a brightness by Hunter and a parallel ray permeability of a melt extrusion molded piece made of copolymeric polyamide which can be obtained by at least one melt extrusion and contains a specified rate of alkylene terephthalic amide unit. CONSTITUTION: A sheet of a melt extrusion molded piece having a thickness of 0.2mm obtainable by at least one process of melt molding as a melt extrusion and consists of a copolymeric polyamide which contains 10-90wt.% of alkylene terephthalic amide unit is adjusted so as to satisfy the following properties: brightness by Hunter >70% and parallel ray permeability >70%. Such a melt molded piece is manufactured in a process for synthesizing a primary condensate of polyamide and a melt extrusion high polymerization process using a twin- screw extruder at a maximum achieving pressure of 5-23kg/cm<2> -G and at a maximum achieving temperature of 260-330 deg.C.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a copolyamide melt-molded product and a method for producing the same, and in particular, a copolyamide such as a film, sheet or thread obtained by melt extrusion processing which is transparent and has no color. The present invention relates to a melt-formed product and a method for producing the same.

[0002]

2. Description of the Related Art Polyamides are widely used in the fields of automobiles, electric and electronic fields, etc. by utilizing their excellent properties as engineering plastics.

Conventionally, nylon 6 and nylon 66 have been mainly used as polyamides, but in the field of microelectronics and temperature rise due to higher output of automobile engines in recent years and higher density in the engine room of automobiles. Along with the progress of miniaturization and high integration, there has been a demand for an ultra-thin material for molded products that can withstand use in a high temperature atmosphere. However, the melting points (Tm) of nylon 6 and nylon 66 are 220 ° C. and 260 ° C., respectively, and even when reinforced with glass fiber, the limit of the heat distortion temperature is up to their respective melting points.

Recently, many polyamide resin compositions containing terephthalic acid and isophthalic acid, or glass fiber reinforced products thereof, have been proposed as polyamide resin compositions capable of withstanding use under these high temperature atmospheres (Japanese Patent Laid-Open No. Sho 61-187). 59-161428, JP-A-59-155426.
JP-A-59-53536, JP-A-62-
156130).

In such a high melting point polyamide melt-molded product, there is a problem that the surface appearance and mechanical properties of the molded product after melt-molding are inferior because the heat history during the production of the polyamide is large. Therefore, various polymerization methods with less heat history have been investigated. As such a polymerization method, a method of forming a primary condensate and then increasing the degree of polymerization has been proposed.

Various proposals have been made for a polymerization method having a small thermal history, such as carrying out the polymerization process of the primary condensate in a short time. JP-A-60-206827 proposes high-pressure, short-time continuous polymerization, and JP-A-2-41318 proposes short-time continuous polymerization using a special apparatus.
It has been desired to develop a versatile polymerization method because it is difficult to switch the product type. Batch polymerization is an easy method to switch the variety, and there are some studies. JP-A-5
In JP-A-170895 and JP-A-5-9381, a polyamide is obtained by forming a primary condensate having a low degree of polymerization under the conditions of high pressure and 250 ° C. JP-A-5-170
As indicated in Japanese Patent Publication No. 895, the problem of batch polymerization is that it precipitates as a solid phase in a polymerization tank. To prevent this, polymerization is performed at a low temperature of 250 ° C. or lower, or 23 kg.
It has been necessary to polymerize at high pressures above / cm ² -G. The primary condensate thus obtained is subjected to a large heat load when the degree of polymerization is increased because of its low relative viscosity, and as a result, polymer color tone and crystallinity, a method of obtaining a high-quality polyamide such as a decrease in melt stability. Is not enough.

As the polymerization degree increasing step, there is a method of carrying out solid phase polymerization for a long time (JP-A-2-41318) or a method of increasing the polymerization degree at a high temperature using an extruder (JP-A-3-434).
17, JP-A-3-17156, JP-A-59
(JP-A-155433, JP-A-5-43681)
Have been proposed.

Particularly in the method using an extruder, the polymerization is carried out at a high temperature, and the development of a method for suppressing thermal deterioration has been desired. In JP-A-3-43417, tetrakis (2,4-di-t-butylphenyl) -4,4'-biphenylene phosphonite is used as a heat resistance stabilizer when the degree of polymerization is increased. However, the heat history was not sufficiently improved because the test was carried out under the conditions of 340 to 345 ° C.

In JP-A-3-17156 and JP-A-59-155433, an extruder is used to increase the degree of polymerization in continuous polymerization. Other than that, no measures for reducing thermal history by screws and forced degassing are shown.

In Japanese Unexamined Patent Publication (Kokai) No. 5-43681, a phosphoric acid compound is used as a catalyst for increasing the degree of polymerization to increase the polymerization rate. However, since an air vent is used, degassing of condensed water is essential. No solution has been taken. Moreover, the residence time of the reaction is long, and the suppression of thermal deterioration is insufficient.

By studying the above-mentioned polymerization method, a polymer having considerably less coloration can be obtained. However, in order to obtain a melt-molded product at a practical stage, it is necessary to further heat it for processing, and the appearance of the melt-molded product is still insufficient. Needless to say, a polyamide with little coloring is used to improve the appearance of the melt-molded product, but further, it was found that the coloring of the melt-molded product depends on the total heat history from the polymerization to the molding process, and we are trying to improve this. No effort was made. Even if efforts are made to reduce the heat history in the molding process, some heat history is unavoidable. Therefore, finding a polymerization method that drastically reduces the heat history during polymerization is a method that reduces the total heat history from polymerization to molding and obtains a transparent, non-colored melt-molded product, but we will dig into it. It was not considered.

[0012]

In the present invention, optical physical properties,
An object of the present invention is to provide a copolyamide melt-molded product having high mechanical strength and a method for producing the same.

[0013]

In view of the above situation, the inventors of the present invention have made earnest studies on a method for solving the above problems, and as a result, use a polyamide satisfying the characteristics of Hunter whiteness and parallel light transmittance. Thus, the inventors have found that a terephthalic acid amide-containing copolymerized polyamide melt-molded product having high appearance and physical properties can be obtained, and thus the present invention has been accomplished. That is, the present invention relates to a "copolymerized polyamide containing 10 to 90% by weight of an alkylene terephthalamide unit obtained through at least one melt molding step, in which at least one melt molding is melt extrusion. The obtained melt extruded product satisfies the following characteristics when measured with respect to a sheet having a thickness of 0.2 mm, and is a copolymerized polyamide melt-formed product: Hunter-Whiteness> 70% (I) Parallel light transmittance> 70% (II) ", and its production method" A method for producing a copolyamide melt-molded article as described above, comprising: (1) reaching a maximum in producing a primary condensate. Pressure is 5kg / cm ²
-G or more and less than 23 kg / cm ² -G, and a step of forming a primary condensate of polyamide under the condition that the maximum attainable temperature exceeds 260 ° C and 330 ° C or less, (2) {screw length L} / { Copolymerization characterized in that the polyamide obtained by the melt extrusion and the step of increasing the degree of polymerization is melt-molded using a twin-screw extruder having a screw segment having an outermost diameter D of the screw of 2 or less. Method for producing polyamide melt-molded product. Is provided.

The details of the present invention will be described below.

The copolyamide of the present invention is a copolyamide containing 10 to 90% by weight of an alkylene terephthalamide unit. The alkylene terephthalamide unit is
It is an amide structural unit formed from terephthalic acid and an aliphatic diamine, and the aliphatic diamine has 4 to 1 carbon atoms.
Aliphatic diamines of 4 are preferred. Specific examples of the aliphatic diamine having 4 to 14 carbon atoms include 1,4-diaminobutane, 1,5-diaminopentane, 1,6-diaminohexane, 1,5-diamino-2-methylpentane and 1,7.
-Diaminoheptane, 1,8-diaminooctane, 1,
9-diaminononane, 1,10-diaminodecane, 1,
Aliphatic alkylenediamines such as 11-diaminoundecane, 1,12-diaminododecane, 1,13-diaminotridecane and 1,14-diaminotetradecane. Of these aliphatic diamines, long-chain aliphatic diamines having a particularly large number of carbon atoms are preferably used in order to reduce the water absorption of the obtained polyamide. These aliphatic diamines can be used alone or in combination of two or more. Particularly, as the aliphatic diamine component having 4 to 14 carbon atoms, that having 6 carbon atoms, that is, 1,6-diaminohexane and 1,5-diamino-2-methylpentane are heat-resistant of the copolymerized polyamide produced, It is preferably used because of its excellent crystallinity balance.

In the copolyamide of the present invention, the amide structural unit forming the remaining part of the alkylene terephthalamide unit is a structural unit derived from dicarboxylic acid and diamine, and a structural unit derived from lactams and amino acids. It was chosen from. The dicarboxylic acid is preferably an aromatic dicarboxylic acid other than terephthalic acid, such as an aliphatic dicarboxylic acid having 4 to 12 carbon atoms or isophthalic acid, and specific examples of the aliphatic dicarboxylic acid having 4 to 12 carbon atoms include succinic acid. , Glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, undecanedioic acid, dodecanedioic acid, pracillic acid, tetradecanedioic acid and the like. As the diamine, the above-mentioned aliphatic diamine having 4 to 14 carbon atoms is preferable, and aromatic diamines such as phenylenediamine can also be used. As the lactams or amino acids, those having 6 to 12 carbon atoms are preferable, and specific examples thereof include lactams such as ε-caprolactam, ζ-enanthlactam, η-capryllactam and ω-laurolactam, and ring-opened products thereof. Is an amino acid. Of the amide structural units derived from these, hexamethylene isophthalamide, caproamide, hexamethylene adipamide, and hexamethylene sebacamide are particularly preferably used alone or in combination in the present invention.

The melting point of the copolymerized polyamide of the present invention is preferably 260 to 320 ° C., more preferably 270.
~ 310 ° C. This range is preferable, when the melting point is low, the heat-resistant resin which is the object of the present invention cannot be obtained, and when the melting point is too high, a high temperature is required during the processing of the resin. This is because there is a problem such as foaming due to the decomposition reaction.

When 1,6-diaminohexane is used as the aliphatic diamine component of the terephthalic acid amide structural unit, the structural unit (I)

Embedded image (Hexamethylene terephthalamide unit (hereinafter referred to as 6T)), and at least one structural unit selected from structural units (II) to (IV),

Embedded image (Hexamethylene isophthalamide unit (hereinafter referred to as 6I)),

Embedded image (Hexamethylene adipamide unit (hereinafter referred to as 66)),

[Chemical 4] A 6T-containing copolyamide having a repeating unit consisting of (caproamide unit (hereinafter referred to as 6)) is preferable.

In the above 6T-containing copolyamide,
For example, when the composition of a two-component copolymer is 6T / 6I, the copolymerization ratio is 45 / 55-80 / 20 by weight,
Preferably 55/45 to 80/20, more preferably 6
It is in the range of 0/40 to 75/25. When the copolymer composition is 6T / 66, the copolymerization ratio is 20 by weight.
/ 80 to 80/20, preferably 30/70 to 70/3
The range is 0, more preferably 30/70 to 60/40. When the copolymer composition is 6T / 6, the weight ratio of the copolymer composition is 40/60 to 90/10, preferably 5
5/45 to 85/15, more preferably 60/40 to 8
It is in the range of 0/20. The copolymerization ratio of these 6T-containing copolyamides is preferably chosen to give a crystalline copolyamide with a polymer melting point in the range of 260 ° C to 320 ° C. The copolymerization ratios by weight of 6T / 6I, 6T / 66 and 6T / 6 are 45/55, 20/80,
When the amount of 6T is less than 40/60, it is not preferable in that the polymer melting point is lowered, the heat resistance such as the heat distortion temperature is lowered, and the 6T content is reduced, so that the water absorption is increased. Also, 6
The copolymerization ratio of T / 6I, 6T / 66 and 6T / 6 is 6T rather than 80/20, 80/20 and 90/10, respectively.
When the amount is large, the polymer melting point becomes high and the heat resistance improves, but
This is not preferable because the processing temperature becomes high and the polymer undergoes thermal decomposition. Among these copolymerized polyamides, 6T / 66 is particularly preferable from the viewpoint of crystallization characteristics, and the copolymerization ratio is 35 / 65-60 / 40 by weight, particularly 37 / 63-5.
Copolyamides in the 0/50 range can achieve excellent properties.

The 6T-containing polyamide of the present invention may be a copolymer of three or more components, and specific examples of preferable copolymerization composition are 6T / 66 / 6I,
Mention may be made of compositions containing 6T / 66 such as 6T / 66/6. 6 in these copolyamides
The T / 66 component is preferably 50% by weight or more,
Further, it is preferably 60% by weight or more, and particularly preferably 70% by weight or more.

A diamine having 12 carbon atoms is also preferably used as the aliphatic diamine of the alkylene terephthalamide unit. In that case (hereinafter, the amide bond unit with terephthalic acid is hereinafter referred to as 12T), hexamethylene adipamide is used. A 12T-containing polyamide in which repeating units such as units, dodecamethylene adipamide units, hexamethylene isophthalamide units, dodecamethylene isophthalamide units, and caproamide units are copolymerized is preferably used.

Next, the melt-molded product of the present invention will be described.

The melt-molded product of the present invention is a melt-molded product obtained through at least one melt-molding step, of which at least one melt-molding is melt extrusion. Examples of the melt molding method include an extrusion molding method, an injection molding method, a melt spinning method, a compression molding method, an inflation molding method, and a blow molding method. Among them, a method involving melt extrusion is an extrusion molding method,
These are the melt spinning method, the inflation molding method and the blow molding method. The shape of the obtained melt-molded product is a film,
Examples of the film, sheet, pipe, container, fiber, gut, rod, and the like, the present invention is effective for a film or a sheet from the viewpoint of mechanical properties which are the effects of the present invention.

The melt-formed product of the present invention satisfies the following characteristics when measured on a sheet-like product having a thickness of 0.2 mm. Hunter-whiteness> 70% (I) Parallel light transmittance> 70% (II) Hunter-whiteness is an index of coloration of samples with the same transparency, and parallel light transmittance is an index of transparency. . In the present invention, the hunter-whiteness and the parallel light transmittance are both 70%.
By using a transparent and non-coloring material that exceeds
It is intended to provide a melt-molded product having excellent appearance and mechanical properties. The Hunter-whiteness is preferably 75% or more, more preferably 80% or more, and the parallel light transmittance is
It is preferably 75% or more, more preferably 80% or more.
By adjusting the hunter whiteness and parallel light transmittance of the present invention within the ranges, it is possible to obtain a melt-molded product having excellent appearance and mechanical properties, but outside the range, it is yellowish and has a mechanical strength. descend. The conventional copolyamide has many microscopic foreign matters and is inferior in appearance and mechanical properties, but the melt-molded product of the present invention has few microscopic foreign matters and improves both appearance and mechanical properties.

The copolyamide of the present invention is a "Hunter
It may be produced by any method as long as it satisfies the conditions of "whiteness>70%" and "parallel light transmittance>70%", but it is possible to obtain such properties by a conventional production method. Was difficult. The present inventors are investigating the appearance of the melt-molded product of the copolyamide, and despite using the co-polyamide that does not seem to change in appearance, the resulting melt-molded product has an appearance, especially microscopic foreign matter. It was found that there are differences in the degree of existence and mechanical properties. As the copolyamide of the present invention, it is preferable to use the copolyamide obtained by the following production method having a small heat history.

The method for producing a copolyamide according to the present invention is a two-stage stacking method in which a primary condensation product of polyamide is synthesized under specific conditions and then melt-extruded by a twin-screw extruder having a specific screw segment to increase the polymerization degree. The legal method is preferably used. First, the method for forming the primary condensate will be described.

In the method for producing the copolymerized polyamide of the present invention, the primary condensate is prepared by charging an aqueous solution of a monomer or salt giving the above-mentioned copolymerization composition into, for example, a pressure polymerization tank and stirring it as a solution using water as a solvent. It is obtained by polymerizing under the conditions. 5% by weight of raw material charged in solution
The above content is preferably 15% by weight or more and 90% by weight or less, preferably 85% by weight or less.

The synthesis of the primary condensate is carried out by raising the temperature and pressure under stirring conditions. The polymerization temperature is raised and controlled within a range from the temperature after the charging or after the concentration step to the highest reached temperature. Further, the polymerization pressure is controlled below the maximum ultimate pressure according to the progress of polymerization. The highest temperature and the highest pressure do not have to be at the end of the polymerization and may be at any time until the completion of the polymerization.

In the synthesis of the above primary condensate, the maximum ultimate pressure may be 5 kg / cm ² -G or more and less than 23 kg / cm ² -G, but preferably 10 kg / cm ² -G or more, 22 kg / cm ² -G. Below, preferably 20kg /
cm ² −G or less. When it is 23 kg / cm ² -G or more, the water content at the time of synthesis is high, so that the degree of polymerization is not increased so much that the reaction rate of the primary condensate is insufficient. Further, if the maximum ultimate pressure is less than 5 kg / cm ² -G, precipitation may occur in the polymerization tank.

The maximum temperature reached during the synthesis of the primary condensate is more than 260 ° C and 330 ° C or less, but when the melting point of the polyamide is less than 280 ° C, it is more than 260 ° C and 300 ° C or less, preferably 290 ° C or less. There is a need. When the melting point of the polyamide is 280 to 320 ° C., it is set higher than the melting point minus 20 ° C., preferably not less than the melting point minus 15 ° C. and not more than the melting point plus 10 ° C., preferably not more than the melting point plus 5 ° C. If the highest temperature reached is 260 ° C or lower, it is insufficient to increase the degree of polymerization of the primary condensate, and it is necessary to lengthen the time for increasing the degree of polymerization or increase the temperature.
The total thermal history of the polyamide polymerization process is large. Further, if the maximum temperature reached exceeds 330 ° C., the thermal history of the primary condensate and the synthesis process alone becomes too large, which is not preferable. In order to reduce the total heat history of the polymerization step, it is necessary to balance the step of synthesizing the primary condensate and the step of increasing the degree of polymerization.

Further, the discharge after the synthesis reaction of the primary condensate is preferably carried out under the pressure of steam. The water vapor pressure may be the maximum ultimate pressure or less, but is preferably the maximum ultimate pressure minus 10 kg / cm ² -G or more and the maximum ultimate pressure or less. The steam pressure is preferably maintained during discharge, and it is preferable to supply water or steam into the polymerization tank and maintain a constant steam pressure during discharge, or discharge while increasing the pressure. When water, preferably ion-exchanged water, is supplied from the outside of the system to the polymerization tank by a metering pump, it is preferable to preheat and supply the water via a heat exchanger. The heating temperature is preferably 100 ° C or higher, more preferably 150 ° C or higher. It is more preferable that the heating temperature is the saturated steam temperature of the pressure in the polymerization tank in order to maintain the stability of the polymerization state. When steam is supplied into the polymerization tank from outside the system, the pressure of the steam generating boiler must be higher than the pressure in the polymerization tank. Further, it is preferable that the temperature at the time of discharging is maintained at the maximum reached temperature minus 10 ° C. or more and the maximum reached temperature or less.

The pressure for synthesizing and discharging the primary condensate of the present invention may be within the range of the above-mentioned maximum temperature and maximum pressure. Even in the precipitation solidification region disclosed in Japanese Patent Laid-Open No. 5-170895, passage or discharge may be performed within the time required for precipitation solidification. The precipitation-solidified region is determined by the composition of polyamide, temperature, pressure and time. For example, at the time of polymerization of 66 / 6T = 50/50% by weight, the temperature and pressure are rapidly raised to 265 ° C. and 27 kg / cm ² -G, and if held under these conditions, precipitation solidification starts after about 5 hours. Also, 265 ° C., 22 kg / cm ² −
If the temperature is raised up to the condition G and the pressure is maintained, the precipitation and solidification will start after about 2 hours. When the temperature rises and pressures are raised under the latter condition and the polymerization route is maintained in that state, precipitation solidification does not become a problem if the polymerization is completed within 2 hours from the start of holding and the composition is discharged. As described above, even in the precipitation-solidified region, it can freely pass within a range that does not reach the time to reach the precipitation, but the transit time in the precipitation-solidified region is the time to reach the precipitation (precipitation time) minus 0. 1 hour or less, preferably precipitation time minus 0.2 hours or less, and more preferably precipitation time minus 0.5 hour or less. Furthermore, the total time for the synthesis of the primary condensate (polymerization reaction and discharge) is 10 hours or less, preferably 7 hours or less, more preferably 5 hours or less, and particularly preferably 4 hours or less.

Further, as a method for avoiding precipitation and solidification during synthesis, it is effective to stir the side surface of the polymerization tank efficiently. The distance between the stirring blade and the polymerization tank is preferably 10% or less, and more preferably 5% or less, with respect to the radius of the polymerization tank. Where the distance between the stirring blade and the polymerization tank is 10% or less with respect to the radius of the polymerization tank, it is preferable that the blade is rotating and occupy 70% or more of the side surface below the liquid surface of the polymerization tank. It is preferably 80% or more and less than 100%. Precipitation and solidification can be delayed by efficiently stirring the side surface of the polymerization tank, which easily reacts by heating.

If necessary, salt preparation and / or concentration may be performed before the synthesis of the primary condensate. The salt tone is a step of producing a salt from a dicarboxylic acid component and a diamine component, and the neutralization point of the salt is within a range of pH ± 0.5, and further,
It is preferable to adjust the neutralization point of the salt within the range of pH ± 0.3. In the concentration, it is preferable to concentrate to the concentration of the raw material charged concentration plus 2 to 90% by weight, more preferably plus 5 to 80% by weight. 90-220 ℃ concentration process
Is preferable, 100 to 210 ° C. is more preferable, and 130 to 200 ° C. is particularly preferable. The pressure of the concentration step is 0 to 20 kg / cm ² -G, preferably 1 to 10 kg
A / cm ² -G. Normally, the concentration pressure is controlled below the synthesis pressure. Further, in order to promote the concentration, for example, a forced discharge operation can be performed with a nitrogen stream or the like. The concentration step is effective in shortening the synthesis time of the primary condensate.

The relative viscosity of the 1% sulfuric acid solution of the primary condensate at 25 ° C. is preferably 1.15 to 2.5, more preferably 1.2 or more, preferably 1.3 or more, and further preferably. It is 1.4 or more and 2.3 or less, preferably 2.0 or less, and more preferably 1.8 or less. When the relative viscosity is less than 1.15, it is necessary to lengthen the polymerization time for increasing the degree of polymerization and increase the temperature, and the total heat history becomes large. On the other hand, if the relative viscosity exceeds 2.5, the melt viscosity of the primary condensate becomes too high, which may cause ejection failure from the polymerization apparatus, which is not preferable. The water content of the primary condensate is 20% by weight or less, preferably 10% by weight or less, more preferably 5% by weight or less. When the water content exceeds 20% by weight, it becomes difficult to increase the degree of polymerization. The moisture content can be controlled by discharging the primary condensate in water and then drying it, or by cooling the discharged high-temperature primary condensate with cooling water and evaporating it using the heat of the primary condensate. It is preferably controlled. In addition, the primary condensate is preferably crushed to an appropriate size before increasing the degree of polymerization.

As an example of a suitable apparatus for synthesizing the primary condensate, a batch reaction tank or a one- to three-tank continuous batch reaction apparatus can be mentioned.

Next, a method of melt extruding the primary condensate to increase the degree of polymerization will be described.

The extruder used in the step of increasing the degree of polymerization of the primary condensate in the present invention is a twin-screw extruder including a screw segment having L / D of 2 or less. Here, L represents the length of the screw segment, and D represents the outer diameter, that is, the outermost diameter when the screw segment is rotated. By using a short screw segment with L / D of 2 or less, the state of the polymer in the cylinder can be finely controlled, thermal deterioration is small,
When processed into a melt-molded product, a product with a good appearance can be obtained. In particular, for the purpose of efficiently polymerizing without undergoing heat deterioration, sufficiently kneading while controlling the state in the cylinder with a short L / D screw segment, and quickly degassing in vacuum to achieve a high degree of polymerization. is necessary. The ratio of the screw segment having L / D of 2 or less is 5% or more with respect to the entire length of the screw,
It is preferably 30% or more, more preferably 50% or more.

The screw segments constituting the screw of the twin-screw extruder include a resin feeding segment and a mixing segment. A forward full flight segment is preferably used as the resin feeding segment, and a rotor is used as the mixing segment. Notch rotor, forward kneading, orthogonal kneading, reverse kneading, kneading neutral, gear kneading, pineapple kneading, twist kneading, reverse full flight, notch flight, etc., one or two types It is preferable to use a combination of the above. Further, as other segments, there are a seal ring, a torpedo ring, etc., and it is effective to use them appropriately. The forward full flight segment includes all of the forward full flight structures, and for example, those having different flight pitches, those having a sharp flight or those having a wide flight can also be used. Further, from the viewpoint of controlling the polymerization reaction, it is effective to use one or more, preferably two or more reverse full flight segments. The segments other than the forward full flight may be arranged in one part or divided into some parts. By using a segment other than the normal full flight, the polymerization reaction can be effectively promoted. The L / D of the forward full flight and the segment other than the forward full flight are selected so as to match the ratio of the screw segment having the L / D of 2 or less described above, but the L / D of the segment other than the forward full flight is 2 The following segments are preferably included, and L / D is 0.2 or more.
It is even more preferred that it contains 8 or less.

The total length of the segments other than the normal full flight is 0% or more, preferably 3% or more, more preferably 5% or more and 70% or less, preferably 50% or less, with respect to the entire screw length. It is more preferably 45% or less. The number of threads of the screw may be any, but 1, 2, 3 threads are preferable, and 2 threads are particularly preferable. The groove type may be either a shallow groove or a deep groove, but a deep groove is more preferable.

The twin-screw extruder according to the present invention may rotate in the same direction or in different directions, but the one rotating in the same direction is preferable from the viewpoint of controlling polymerization conditions. Rotation speed is 50 rpm or more, preferably 70 rpm or more, 800
rpm or less, preferably 500 rpm or less. A larger rotation number is better for shearing and stirring, and further for renewing the resin surface for degassing the condensation water, but if it is too large, the shear heat generation will become too large and the resin will be deteriorated. It is preferable to select the number of rotations.

The L / D of the entire screw of the twin-screw extruder used in the present invention is not particularly limited, but is usually set to 10 or more, preferably 15 or more and 100 or less, preferably 70 or less. . When it is less than 10 or more than 100, it is difficult to stably promote the high degree of polymerization.

Next, the extrusion conditions for increasing the degree of polymerization by the extruder in the present invention will be described.

In the present invention, the high degree of polymerization by the extruder is expressed by the formula (G) while vacuum degassing is performed by using the above twin-screw extruder.
It is preferable to carry out within the range of the residence time that satisfies

T ≦ 5000 × Δηr / (TR-280) (G) (t: retention time (seconds)) (Δηr: amount of change in relative viscosity due to high polymerization degree) (TR: resin at high polymerization degree) It is preferable to increase the degree of polymerization within the range of the residence time that satisfies the formula (H). 20 ≦ t ≦ 4000 × Δηr / (TR-280) (H) However, although the residence time has a distribution, in the present invention, the shortest residence time generally used as t is adopted.
When heat is applied more than necessary at the time of increasing the degree of polymerization, the physical properties deteriorate due to thermal deterioration, and if it is too short, the degree of polymerization does not rise,
It is preferably within the range of the residence time. The amount of change in relative viscosity (Δηr) due to the increase in the degree of polymerization is preferably 0.2 or more, more preferably 0.5 or more. The maximum temperature reached by the resin when the degree of polymerization is increased is the melting point or higher, preferably the melting point plus 10 ° C. or higher and 350 ° C. or lower, preferably 340 ° C. or lower, more preferably 330 ° C. or lower. If the maximum temperature is too high, the thermal load is large even if the residence time is short, which is not preferable. In particular, it is important to keep the temperature at 350 ° C. or lower in order to prevent thermal decomposition and thermal deterioration of the polymer.

In the present invention, the vacuum degassing at the time of increasing the degree of polymerization by the extruder is carried out from one or more vents,
The shape of the vent may be any. The vacuum deaeration is for shifting the chemical equilibrium by removing the water generated by the polymerization, and it is important to perform it efficiently so that the polymerization degree is increased within a certain retention time. Therefore, the degree of vacuum of the vent is -500 mmHg or less,
It is preferably −600 mmHg or less. Further, in addition to the above-described vent having the degree of vacuum, a vent having a low degree of vacuum or an atmosphere vent may be used in combination.

The degree of polymerization of the copolyamide of the present invention is not particularly limited, and it is practical that the relative viscosity (ηr) of a 1% sulfuric acid solution at 25 ° C. is usually in the range of 1.8 to 5.0. And those in the range of 2.0 to 3.5 are preferable.

In ordinary polyamide polymerization, the raw materials are generally charged so that the total amount of the carboxyl groups and the total amount of the amino groups contained in the monomer and the dicarboxylic acid / diamine salt are equal to each other. It is also possible to prepare a polyamide having a large amount of terminal carboxyl groups or terminal amino groups by adding an excess of dicarboxylic acid component or diamine component when charging the raw materials. The amount of excess dicarboxylic acid or diamine added is in the range of 10 mol% or less, preferably 8 mol% or less, more preferably 7 mol% or less. If the amount added exceeds 10 mol%, it becomes difficult to increase the degree of polymerization, which is not preferable. Further, in the polymerization reaction of the present invention, it is effective to add a polymerization degree modifier in order to facilitate the adjustment of the polymerization degree of the polyamide and the adjustment of the polymerization degree when the polymerization degree is increased. As the polymerization degree regulator, usually, a monoamine compound and a monocarboxylic acid compound are used, preferably acetic acid,
Benzoic acid, stearic acid, particularly preferably acetic acid,
Benzoic acid. The degree of polymerization modifier is 0.0001 times mol or more and 0.1 times mol or less, preferably 0.1 times mol or less, based on the mol number of the constituent monomer and the total mol number of the dicarboxylic acid component unit and the diamine component unit of the salt. It is used in a range of not more than 05 times by mole.

For the polymerization of polyamide, it is effective to use a phosphorus-based catalyst having the effect of promoting the polymerization reaction. For example, hypophosphite, phosphate, hypophosphorous acid, phosphoric acid, phosphoric acid ester, polymetaphosphoric acid, polyphosphoric acid, phosphine oxides, phosphonium halogen compounds and the like are preferable, hypophosphite, phosphate , Hypophosphorous acid and phosphoric acid are particularly preferably used. Specific examples of the hypophosphite include, for example, sodium hypophosphite, potassium hypophosphite, calcium hypophosphite, magnesium hypophosphite, aluminum hypophosphite, vanadium hypophosphite, hypophosphite. Manganese acid, zinc hypophosphite, lead hypophosphite, nickel hypophosphite, cobalt hypophosphite, ammonium hypophosphite and the like are preferable, and sodium hypophosphite, potassium hypophosphite, hypophosphite, etc. Calcium phosphate and magnesium hypophosphite are particularly preferred. Examples of the phosphate include sodium phosphate, potassium phosphate, potassium dihydrogen phosphate, calcium phosphate, vanadium phosphate, magnesium phosphate, manganese phosphate, lead phosphate, nickel phosphate, cobalt phosphate, and phosphoric acid. Ammonium, diammonium hydrogen phosphate and the like are preferable. Examples of the phosphoric acid ester include ethyl octadecyl phosphate. Examples of the polymetaphosphoric acids include sodium trimetaphosphate, sodium pentametaphosphate, sodium hexametaphosphate, polymetaphosphoric acid, and the like. Examples of polyphosphoric acids include sodium tetrapolyphosphate and the like. Examples of the phosphine oxides include hexamethylphosphoramide. The amount of the phosphorus-based catalyst added is 0.0 with respect to 100 parts by weight of the polyamide.
001 to 5 parts by weight is preferable, and 0.001 to 1 part by weight is more preferable. Further, the addition time may be any time until the completion of the high degree of polymerization, but it is preferably from the time of charging the raw materials to the completion of the polymerization of the primary condensate. Moreover, you may add many times. Further, different phosphorus-based catalysts may be added in combination.

A filler may be further added to the melt-molded product of the copolyamide of the present invention. As the filler, glass fiber or glass beads, talc, kaolin, wollastonite, mica, silica, alumina, diatomaceous earth, clay, gypsum, red iron oxide, graphite, titanium dioxide, zinc oxide, copper, stainless powder, etc. In addition, plate-like inorganic compounds, other polymer fibers (carbon fibers, aramid fibers, whiskers) and the like are exemplified, and glass fibers are preferable. Particularly preferred as glass fibers are glass rovings, glass chopped strands and the like made from strands of continuous long fibers having a diameter of about 3 to 20 μm. When such a filler is used, the compounding ratio is usually 1 part by weight or more, preferably 10 parts by weight or more and 200 parts by weight or less, preferably 150 parts by weight or less, more preferably 100 parts by weight of the polyamide resin composition. Is 100 parts by weight or less. When the blending ratio of the filler exceeds 200 parts by weight, the fluidity at the time of melting is deteriorated, it is difficult to extrude a thin molded product, and the appearance of the molded product is deteriorated, which is not preferable. The method of adding the filler to the copolyamide of the present invention is not particularly limited, and any known method can be used. As a specific example of the compounding method, polyamide pellets are dry blended with a filler, and this is uniaxially screwed.
Alternatively, a method of melt-kneading with a twin-screw extruder may be used. Further, when the degree of polymerization is increased with a twin-screw extruder, a method of adding a filler from the middle of the twin-screw extruder is also possible.

The melt-molded product of the copolyamide of the present invention contains a catalyst, if necessary, at the stage of polymerization of primary condensate, high degree of polymerization of melt, compound or molding process.
Heat stabilizers, weathering stabilizers, plasticizers, release agents, lubricants, nucleating agents, pigments, dyes, other polymers, and the like can be added. These additives include heat-resistant stabilizers (hindered phenol-based, hydroquinone-based, phosphite-based and substitution products thereof, copper iodide, potassium iodide, etc.), weather-resistant stabilizers (resorcinol-based, salicylate-based, benzoic acid-based Triazole-based, benzophenone-based, hindered amine-based, etc., release agents and lubricants (montanic acid and its metal salts, their esters, their half esters,
Stearyl alcohol, stearamide, various bisamides, bisurea and polyethylene wax, etc.), pigments (cadmium sulfide, phthalocyanine, carbon black, etc.), and dyes (such as nigrosine), other polymers (other polyamides, polyesters, polycarbonates,
Polyphenylene ether, polyphenylene sulfide,
Liquid crystal polymer, polyethylene sulfone, ABS resin, S
AN resin, polystyrene, acrylic resin, polyethylene, polypropylene, ethylene / α-olefin copolymer, ionomer resin, SBS, SEBS and the like).

The melt-molded product of the composition obtained by blending the copolyamide of the present invention and the above-mentioned reinforcing material, filler, additive and the like is processed into the shape of film, sheet, pipe, fiber, rod, container and the like. For example, heat-resistant film, food film, air pipe connector, insulator, chamber tank, reservoir tank,
Electric / electronic parts such as intake / exhaust pipes, heat-resistant containers, microwave oven films, automobile / vehicle related parts, household / office electrical product parts, computer related parts, facsimile / copier related parts, machine related parts, It is useful for various other purposes.

[0053]

The present invention will be described in more detail with reference to the following examples. Various properties in the examples and comparative examples were measured by the following methods.

1) Melting point (Tm) Samples 8 to 10 using DSC (PERKIN-ELMER7 type)
The temperature showing the maximum value of the melting curve obtained by measuring mg at a temperature rising rate of 20 ° C./min is defined as (T ₁ ). Sample 8
-10 mg is heated at a temperature rising rate of 20 ° C / min to give T ₁ +2.
Hold at 0 ° C. for 5 minutes, then cool to 30 ° C. at a cooling rate of 20 ° C./min, hold at 30 ° C. for 5 minutes, then repeat 2
Heat to T ₁ + 20 ° C. at a heating rate of 0 ° C./min.
The maximum value of the melting curve at this time was defined as the melting point (Tm).

2) Relative Viscosity According to JIS K6810, 1 g of the sample was dissolved in 100 ml of 98% concentrated sulfuric acid and the relative viscosity at 25 ° C. was measured. Hereinafter, the relative viscosity is abbreviated as ηr.

3) Residence time The pigment was added from the feeder when the polymerization degree was increased by the extruder, and the time until the molten polymer started to be colored was measured.

4) Hunter whiteness and parallel light transmittance The extruded products such as the sheets and filaments produced in the examples were re-molded into a sheet having a thickness of 0.2 mm using a hot press. Using a total (Suga Tester Co., Ltd. SM color computer, SM-5),
In accordance with JIS L1015, the parallel light transmittance is measured by a haze meter (Toyo Seiki Seisakusho DIRECT
READING HASE METER)
Each was measured according to IS K6714.

5) Tensile Strength, Elongation Cut into strips with a width of 1 cm and performed using Tensilon (Orientec, UTM-4).

6) Appearance The sheet was magnified 10 times with an actual microscope and 1 cm ² was observed. The presence of black foreign matter was regarded as defective, and the other was judged as good.

Each embodiment will be described below. Table 1 shows reaction conditions, characteristics, etc., and the addition amount of monocarboxylic acid is shown therein. This amount means the amount (double mole) with respect to the total number of moles of the monomer of the constituent components and the salt of the dicarboxylic acid component unit and the diamine component unit.

Example 1 Hexamethylene diammonium adipate (66 salt),
The composition and concentration of terephthalic acid, hexamethylenediamine, benzoic acid, ion-exchanged water and sodium hypophosphite are shown in Table 1, and the distance between the screw and the tank is 1 of the tank radius.
~ 3% occupies 95% of the side surface below the liquid level.
After charging to a batch type pressure polymerization tank of 10 m ³ and performing sufficient nitrogen substitution, the temperature was raised to 150 ° C. and the pressure under stirring was 3.0 kg.
/ Cm ² -G to a concentration of 85% by weight. Subsequently, the temperature was raised to the maximum attainable temperature of 290 ° C. over 2.5 hours with stirring, and the maximum polymerization pressure was set to 20 kg / cm ² -G. The discharge was performed over 0.5 hours while supplying ion-exchanged water by a metering pump at a rate of 2 l / hr and maintaining the water vapor pressure at 20 kg / cm ² -G. The viscosity of this primary condensate was ηr = 1.7, and the melting point was 290 ° C.

The obtained primary condensate was heated at 100 ° C. for 24 hours.
After vacuum drying, the degree of polymerization was increased by an extruder. The extruder used was a vent type twin-screw extruder (L / D = 45.5) having 30 mmφ and two long and short vent ports, and the same rotation type, deep groove type was used. The screw is composed of a forward full flight with L / D of 2 or less and a segment other than the forward full flight.
%, Segment other than forward full flight (L / D = 0.5
The combination of forward kneading, reverse kneading, reverse full flight, and seal ring) is about 30%, and screw segments other than these normal full flights are 3 before the long vent, just before the short vent, and 3 in the melting zone.
It was used by dividing it into three parts. The residence time from the introduction of the primary condensate to the discharge was 80 seconds, the long vent of L / D = 5 to the vacuum degree of −700 mmHg and L / D =
It was degassed from the short vent of 1.8 under the condition of a vacuum degree of -700 mmHg, operated at a screw rotation speed of 150 rpm and a maximum resin temperature of 315 ° C., and was melted to have a high polymerization degree to obtain white pellets. The relative viscosity ηr was 2.7 and the melting point was 292 ° C.

The obtained pellets were formed into a sheet having a thickness of 0.3 mm by a uniaxial extruder equipped with a T die. The appearance of the sheet was observed and found to be good. After re-molding this sheet into a sheet with a thickness of 0.2 mm by hot pressing,
When measured, Hunter whiteness was 88% and parallel light transmittance was 85%. Table 1 shows the polymerization conditions and measurement results.
Shown in

Example 2 Table 1 shows salts of terephthalic acid and hexamethylenediamine, hexamethyleneammonium adipate (66 salt), salts of isophthalic acid and hexamethylenediamine, sodium hypophosphite and ion-exchanged water. With the composition and concentration shown in, the distance between the screw and the tank is 2 to 4 of the tank radius.
0.1m occupies 90% of the side surface below the liquid level
^After being charged in the batch type pressure polymerization tank of No. 3 and sufficiently replaced with nitrogen, the temperature was raised to the maximum attainable temperature of 285 ° C. over 2.0 hours with stirring, and the maximum polymerization pressure was set to 20 kg / cm ² -G.
Discharge is 0.2 l / h of ion-exchanged water with a metering pump.
It was supplied at a rate of r and was carried out for 0.3 hours while maintaining the water vapor pressure at 20 kg / cm ² -G. The melting point of the obtained primary condensate was 295 ° C., and ηr was 1.6.

The obtained primary condensate was heated at 100 ° C. for 24 hours.
After vacuum drying, the polymerization degree was increased using a vent type twin-screw extruder (L / D = 25, rotating in the same direction, deep groove type) equipped with a long vent of 30 mmφ. The screw is composed of screw segments with L / D of 2 or less. 78% of the full forward flight is a segment other than the full forward flight (order kneading of L / D = 0.3 to 0.8, reverse knee, reverse knee) 22% of the squeeze segment, cross kneading, reverse full flight, seal ring, and kneading needral). These squeeze segments other than normal full flight are placed at two locations just before the long vent and in the melting zone. Using. The residence time of the primary condensate is 75 seconds, and the degree of vacuum is -700 mm from the long vent of L / D = 5.
After degassing with Hg, the screw rotation speed is 150 rpm, and the maximum resin temperature is 320 ° C.
A 0.3 mm thick sheet was obtained from the T-die. The obtained product had a relative viscosity ηr = 2.6 and a melting point of 298 ° C. and had a good appearance. This sheet was re-formed into a sheet having a thickness of 0.2 mm by hot pressing, and the whiteness of the hunter and the parallel light transmittance were measured. The polymerization conditions and measurement results are shown in Table 1.

Example 3 Salt consisting of terephthalic acid and hexamethylenediamine, hexamethylene diammonium adipate (66 salt), ε
-Caprolactam, acetic acid, phosphoric acid and distilled water were charged in the composition and concentration shown in Table 1, the maximum attainable temperature was 280 ° C, the maximum polymerization pressure was 22 kg / cm ² -G, as in Example 2.
The primary condensate was polymerized under the condition that the water vapor pressure during discharge was 22 kg / cm ² -G and the total time of weight and discharge was 2.0 hours.

The resulting primary condensate was heated at 100 ° C. for 24 hours.
After vacuum drying, the degree of polymerization was increased by an extruder. The extruder used was a vent type twin-screw extruder (L / D = 45.5) equipped with two long and short vent holes of 30 mmφ, and was a co-rotating, deep groove type. The screw has a forward full flight with an L / D of 2 or less and a segment other than forward full flight 7
8% and forward full flight with L / D over 2 22
% Of the segment other than forward full flight (L / L
D = 0.5 to 1 for forward kneading, reverse kneading, orthogonal kneading, reverse full flight, and seal ring) is 22% of that, and screw segments other than these normal full flight are long vented. The ones that were placed at three positions immediately before, just before the short vent, and in the melting zone were used. The residence time from the introduction of the primary condensate to the discharge was 70 seconds, and degassing was performed from the long vent with L / D = 5 at a vacuum degree of -700 mmHg and from the short vent with L / D = 1.8 at a vacuum degree of -700 mmHg. , A screw rotation speed of 200 rpm, and a maximum resin temperature of 320 ° C. were melted to have a high degree of polymerization, and extruded white solid pellets having a relative viscosity ηr = 2.5 and a melting point of 287 ° C.

The obtained pellets were spun using a melt spinning tester under the conditions of a nozzle of 0.5 mmφ × 18 holes, a nozzle temperature of 305 ° C., and a take-up speed of 30 mm / min to obtain a colorless and transparent multifilament.

Table 1 shows the polymerization conditions and the measurement results.

Example 4 Hexamethylene diammonium adipate (66 salt),
A salt composed of terephthalic acid and hexamethylenediamine, benzoic acid and ion-exchanged water were charged in a batch type pressure polymerization tank of 0.1 m ^{3 with} the composition and concentration shown in Table 1, and sodium hypophosphite was additionally added after concentration. Then, the primary condensate was polymerized and the degree of polymerization was increased in the same manner as in Example 1. Further, a sheet was prepared in the same manner as in Example 1 and evaluated in the same manner. The polymerization conditions and measurement results are shown in Table 1.

Example 5 Hexamethylene diammonium adipate (66 salt),
Using a salt of terephthalic acid and hexamethylenediamine as a raw material, a primary condensation product was polymerized in the same manner as in Example 1 using a 0.1 m ³ batch pressure polymerization tank. Further, the degree of polymerization was increased in the same manner as in Example 1. Further, a sheet was prepared in the same manner as in Example 1 and evaluated in the same manner. The polymerization conditions and measurement results are shown in Table 1.

Example 6 Polymerization of the primary condensate was carried out in the same manner as in Example 1 using a salt of terephthalic acid and dodecamethylenediamine and a salt of adipic acid and dodecamethylenediamine as raw materials.

The obtained primary condensate was heated at 100 ° C. for 24 hours.
After vacuum drying, 20 mmφ vent type twin-screw extruder (L
/ D = 25, rotation in the same direction, deep groove type) was used to increase the degree of polymerization. The screw is composed of screw segments with L / D of 2 or less, and the forward full flight part is the entire 7
8%, segments other than forward full flight (L / D = 0.
22% of 7-1.5 forward kneading, reverse kneading, orthogonal kneading, reverse full flight, seal ring, kneading needleal, and these screw segments other than normal full flight are divided into 3 parts. The arranged one was used.

Further, a sheet was prepared in the same manner as in Example 1 and evaluated in the same manner. The polymerization conditions and measurement results are shown in Table 1.

Example 7 Salt consisting of terephthalic acid and hexamethylenediamine, ε
Polymerization of the primary condensate and high degree of polymerization were carried out in the same manner as in Example 1 using a salt of caprolactam as a raw material. Further, a sheet was prepared in the same manner as in Example 1 and evaluated in the same manner.
The polymerization conditions and measurement results are shown in Table 1.

Example 8 A primary condensate was polymerized and a polymerization degree was increased in the same manner as in Example 1 using a salt of terephthalic acid and hexamethylenediamine and a salt of isophthalic acid and hexamethylenediamine as raw materials. Further, a sheet was prepared in the same manner as in Example 1 and evaluated in the same manner. The polymerization conditions and measurement results are shown in Table 1.

In the methods of Examples 1 to 8, the whiteness of the hunter and the transmittance of the parallel rays were each 70% or more. Therefore, the appearance of the obtained extruded sheet and yarn was excellent without coloring. The tensile strength and tensile elongation were also excellent.

[0078]

[Table 1]

Comparative Example 1 The same preparation as in Example 1 was carried out, and the maximum temperature reached was 245.
The temperature was set to 0 ° C and the primary condensate was polymerized in the same manner as in Example 1 except the above. The melting point of the obtained primary condensate was 286 ° C., and ηr was 1.14.

The obtained primary condensate was heated at 100 ° C. for 24 hours.
After vacuum drying, the residence time was lengthened to 240 seconds under the same conditions as in Example 1 so that the relative viscosity was 2.7, and the polymerization degree was increased. Further, a sheet was prepared in the same manner as in Example 1 and evaluated in the same manner. Table 2 shows the polymerization conditions and the measurement results.

Comparative Example 2 The same preparation as in Example 1 was carried out, and the maximum ultimate pressure was 50 k.
The primary condensate was polymerized in the same manner as in Example 1 except that g / cm ² -G was used. The melting point of the obtained primary condensate is 28.
At 5 ° C., ηr was a primary condensate of 1.14.

The obtained primary condensate was heated at 100 ° C. for 24 hours.
After vacuum drying, the residence time was lengthened to 240 seconds under the same conditions as in Example 1 so that the relative viscosity was 2.7, and the polymerization degree was increased. Further, a sheet was prepared in the same manner as in Example 1 and evaluated in the same manner. Table 2 shows the polymerization conditions and the measurement results.

Comparative Example 3 The same charging as in Example 1 was performed, and the maximum temperature reached was 335.
The temperature was set to 0 ° C and the primary condensate was polymerized in the same manner as in Example 1 except the above.

The obtained primary condensate was heated at 100 ° C. for 24 hours.
After vacuum drying, with a vent type single screw extruder of 20 mmφ,
The polymerization degree was increased by using an integral type screw without a mixing zone. A short vent of L / D = 1.8 was degassed at a vacuum degree of -700 mmHg, and the polymerization degree was increased under the conditions of a residence time of 270 seconds, a screw rotation speed of 150 rpm, and a maximum resin temperature of 325 ° C. Further, a sheet was prepared in the same manner as in Example 1 and evaluated in the same manner. Table 2 shows the polymerization conditions and the measurement results.

In Comparative Example 1, the maximum temperature reached during the polymerization of the primary condensate was low, and in Comparative Example 2, the maximum pressure reached during the polymerization of the primary condensate was high. The appearance and tensile properties of the extruded product were poor. In Comparative Example 3, the parallel light transmittance was insufficient because the polymerization degree was not efficiently increased by using a specific screw segment when the polymerization degree was increased, and as a result, the appearance and the tensile properties were poor.

[0086]

[Table 2]

[0087]

EFFECTS OF THE INVENTION By satisfying the characteristics of Hunter whiteness and parallel light transmittance in the copolyamide melt-molded product of the present invention, a copolyamide melt-molded product having high appearance and mechanical properties can be obtained. It is especially suitable as a material for electric / electronic parts and as an automobile part.

Continuation of front page (51) Int.Cl. ⁶ Identification number Office reference number FI technical display location // B29K 77:00 B29L 7:00

Claims (6)

[Claims] 1. A copolymerized polyamide melt-molded product containing 10 to 90% by weight of an alkylene terephthalamide unit, obtained through at least one melt-molding step, wherein at least one melt-molding is melt extrusion. The melt extruded product obtained here satisfies the following characteristics when measured with respect to a sheet having a thickness of 0.2 mm. Hunter-Whiteness> 70% (I) Parallel light transmittance> 70% (II) 2. The melt-molded product of a copolymerized polyamide according to claim 1, wherein the alkylene terephthalamide unit is a hexamethylene terephthalamide unit. 3. An amide structural unit and / or carbon number in which the structural unit other than the hexamethylene terephthalamide unit is derived from an aliphatic diamine having 4 to 14 carbon atoms and a dicarboxylic acid other than terephthalic acid having 4 to 12 carbon atoms. The copolyamide melt-molded product according to claim 2, which is an amide structural unit derived from 6 to 12 lactams or amino acids. 4. The structural unit other than the hexamethylene terephthalamide unit is at least one selected from hexamethylene isophthalamide, hexamethylene adipamide, hexamethylene sebacamide and capramide. Copolyamide melt-molded product. 5. The melt-molded copolymer polyamide according to any one of claims 1 to 4, wherein the melt-molded product is a film or a sheet. 6. A method for producing a copolyamide melt-molded product according to claim 1, wherein the highest ultimate pressure is 5 kg / cm ² -G or more and less than 23 kg / cm ² -G. Yes, the process of synthesizing the primary condensation product of polyamide under the condition that the maximum temperature is higher than 260 ℃ and lower than 330 ℃, (2)
{Screw length L} / {Outermost screw diameter D} is melt-extruded by using a twin-screw extruder including a screw segment having a screw segment of 2 or less, and the polyamide obtained is melt-molded in the order of high polymerization degree steps. A method for producing a copolyamide melt-molded product, comprising: