JPH08109255A - Production of polyamide, and twin-screw extruder for polyamide polymerization - Google Patents

Abstract

PURPOSE: To efficiently increase the degree of polymn. of a polyamide by producing it by a process involving a specific step of increasing the degree of polymn. using a twin-screw extruder. CONSTITUTION: A polyamide is produced by a process involving the step of increasing the degree of polymn. using an extruder. In this step, the relative viscosity of the 1% soln. in conc. sulfuric acid at 25 deg.C is increased by 0.2 or higher by using a twin-screw extruder having a screw segment with a ratio of the screw length L to the outermost screw diameter D of 2 or lower. This process permits not only an efficient production of a polyamide but also improvements in the color tone, tensile strength, elongation, bending strength, bending modulus, chemical resistance, etc., thereof, and provides a polyamide esp. suitable for electric and electronic parts and automotive parts.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a method for producing a polyamide and a twin-screw extruder for polymerizing a polyamide, and more particularly to a method for producing a polyamide and a twin-screw extruder for polymerizing a polyamide efficiently. Is.

[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, polyamides have been polymerized by batch polymerization in a pressure polymerization tank, continuous polymerization in a multi-stage reaction tank, and
Polymerization combining these methods with solid-phase polymerization has been carried out. However, there has been a demand for the development of a polymerization technique that accompanies higher performance of polyamides, and a production method for more efficiently increasing the polymerization degree of polyamides from the viewpoint of improving the productivity of existing polyamides.

Recently, as a method of polymerizing a polyamide having a high melting point containing terephthalic acid, a method of forming a primary condensate and then increasing the degree of polymerization has been proposed (Japanese Patent Laid-open No. Sho 60).
-206827). As a process for increasing the degree of polymerization, a method of performing solid-phase polymerization for a long time (Japanese Patent Laid-Open No. 2-41318)
Method) and a method of increasing the degree of polymerization at a high temperature by using an extruder (JP-A-3-43417, JP-A-3-17156).
Japanese Patent Laid-Open No. 59-155433, Japanese Patent Laid-Open No. 5-155433
No. 43681) is proposed.

Particularly in the method using an extruder, the polymerization is carried out at a high temperature, and it has been desired to develop a method for suppressing thermal deterioration. 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.

[0006] 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 Patent Laid-Open 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.

As shown above, various attempts have been made to develop a production method for efficiently increasing the polymerization degree of polyamide.

[0009]

However, these polymerization methods do not take an essential solution to reduce the heat history during the polymerization, and are not a production method for efficiently increasing the polymerization degree of polyamide. Absent. Therefore, in the present invention, the thermal deterioration in the process of increasing the degree of polymerization is reduced, and by effectively increasing the degree of polymerization of the polyamide, the original performances of the polymer such as color tone, tensile strength, tensile elongation, bending strength, bending elastic modulus, and An object of the present invention is to provide a method for producing a polyamide resin capable of sufficiently exhibiting chemical properties and the like, and a twin-screw extruder for polyamide polymerization.

[0010]

In view of the above circumstances, the inventors of the present invention have made earnest studies on a method for solving the above problems, and as a result, in the process of increasing the degree of polymerization of the primary condensate, it is advantageous for shearing and stirring. By using a screw segment, or by performing the polymerization in a short time under sufficient vacuum deaeration, not only can the thermal history of the process of increasing the degree of polymerization be reduced,
The present invention has been achieved by finding that the original performance of the polymer can be obtained.

That is, the present invention provides a method for producing a polyamide having a step of increasing the degree of polymerization using an extruder, wherein the step of increasing the degree of polymerization is (1) "{screw length L} / {screw maximum A method for producing a polyamide, comprising the step of increasing the relative viscosity of a 1% concentrated sulfuric acid solution at 25 ° C. by 0.2 or more using a twin-screw extruder including a screw segment having an outer diameter D} of 2 or less. (2) “Using a twin-screw extruder, increase the relative viscosity of a 1% concentrated sulfuric acid solution at 25 ° C. by 0.2 or more under the condition that the relationship of formula (I) is satisfied while performing vacuum deaeration. Process for producing polyamide characterized by the following steps: t ≦ 5000 × Δηr / (T-280) --- (I) (t: residence time (sec), Δηr: change in relative viscosity due to high degree of polymerization Amount), and (3) "{screen Length L} / {outermost diameter D of screw} using a twin-screw extruder including a screw segment of 2 or less under vacuum deaeration while satisfying the relationship of formula (I), A method for producing a polyamide, which comprises a step of increasing the degree of polymerization to increase the relative viscosity of a 1% concentrated sulfuric acid solution at 25 ° C. to 0.2 or more: t ≦ 5000 × Δηr / (T-280) --- (I ) (T: residence time (seconds), Δηr: amount of change in relative viscosity due to increasing degree of polymerization) ”, and (4)“ a twin-screw extruder having a segment screw ”used in the above method. , {Screw length L} / {outermost diameter D of screw} includes a screw segment having a value of 2.0 or less with respect to L / D of the entire screw of the extruder,
And the L / D of the total of the segments other than forward full flight
Is 3 to 70%, a twin-screw extruder for polymerizing polyamide. It consists of.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION The polyamide of the present invention may be either crystalline polyamide or amorphous polyamide as long as it has an amide bond. Examples of the amorphous polyamide include copolymers of aliphatic dicarboxylic acids / aliphatic diamines, copolymers containing alicyclic dicarboxylic acids or / and alicyclic diamines, aromatic compounds such as isophthalic acid, and metaxylenediamine. Examples thereof include a copolymer containing a group. Examples of crystalline polyamides include aliphatic crystalline polyamides and semi-aromatic crystalline polyamides. Among them, the semi-aromatic polyamide is preferably used because the effect of the present invention is remarkably pronounced.

Examples of the aliphatic crystalline polyamide include polyamides composed of lactams such as ε-caprolactam, ζ-enanthlactam, η-capryllactam and ω-laurolactam, and aliphatic dicarboxylic acids such as nylon 66 and nylon 46. Examples include polyamides composed of aliphatic diamines. Particularly preferred is a crystalline polyamide containing a hexamethylene adipamide structure and / or a caproamide structure.

As the semi-aromatic crystalline polyamide, a polyamide containing a structure consisting of an aliphatic diamine and terephthalic acid is preferably used. The melting point of the semi-aromatic crystalline polyamide is preferably 230-
A temperature of 340 ° C, more preferably 270 to 340 ° C is used. This range is preferably used,
This is because if the melting point is low, heat resistance cannot be obtained, and if the melting point is too high, a high temperature is required during processing of the resin, which causes problems such as thermal deterioration.

Although the aliphatic diamine of the semi-aromatic crystalline polyamide may be any, an aliphatic diamine having 4 to 14 carbon atoms is preferable from the viewpoint of the balance of the melting point and water absorption of the polyamide. As a specific example,
4-diaminobutane, 1,5-diaminopentane, 1,
6-diaminohexane, 1,5-diamino-2-methylpentane, 1,7-diaminoheptane, 1,8-diaminooctane, 1,9-diaminononane, 1,10-diaminodecane, 1,11-diaminoundecane, 1,12
-Diaminododecane, 1,13-diaminotridecane,
It is an aliphatic alkylenediamine such as 1,14-diaminotetradecane. Among them, those having 6 carbon atoms and those having 12 carbon atoms are preferable, and those having 6 carbon atoms, that is, 1,
6-diaminohexane is more preferably used. In addition, aliphatic diamines having 15 to 40 carbon atoms such as 1,15-diaminopentadecane, 1,16-diaminohexadecane, 1,17-diaminoheptadecane, 1,18-diaminooctadecane and dimer acid can also be used. These diamines may be used alone or in combination of two or more. Further, aromatic diamines such as meta-xylene diamine, para-xylene diamine, and phenylenediamine can be used together.

As the acid component of the semi-aromatic crystalline polyamide, those containing terephthalic acid are preferable, and oxalic acid,
Carbon number of malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, undecanedioic acid, dodecanedioic acid, pracilinic acid, tetradecanedioic acid, pentadecanedioic acid, octadecanedioic acid, etc. You may use together with 2-18 aliphatic dicarboxylic acids, aromatic dicarboxylic acids, such as isophthalic acid. Particularly preferred is the combined use with adipic acid and isophthalic acid. It can also be used in combination with lactams. For example, ε-caprolactam, ζ-enanthlactam, η-capryllactam, ω-laurolactam and the like, preferably ε
-Caprolactam.

When an aliphatic diamine component having 6 carbon atoms is used in the semi-aromatic crystalline polyamide, the structural unit (I) is used.

[Chemical 9] (Hexamethylene terephthalamide unit (hereinafter referred to as 6T)), and at least one structural unit selected from structural units (II) to (IV),

[Chemical 10] (Hexamethylene adipamide unit (hereinafter referred to as 66)),

[Chemical 11] (Hexamethylene isophthalamide unit (hereinafter referred to as 6I)),

[Chemical 12] A 6T-containing copolyamide having a repeating unit consisting of (caproamide unit (hereinafter referred to as 6)) is preferably used.

In the above 6T-containing copolyamide, for example, in the case of two components, the copolymerization ratio of 6T / 6I is 45 / 55-80 / 20, preferably 55 / 45-by weight.
It is used in the range of 80/20, more preferably 60/40 to 75/25. Further, in 6T / 66, the copolymerization ratio is 20/80 to 80/20 in weight ratio, preferably 30/7.
0-70 / 30, more preferably 30 / 70-60 / 4
Used in the 0 range. Further, in 6T / 6, the copolymerization ratio is 40/60 to 90/10 by weight, preferably 55 /.
45-85 / 15, more preferably 60 / 40-80 /
Used in the range of 20. The copolymerization ratio of these 6T-containing copolyamides is such that the polymer melting point is approximately 230 ° C to 3 ° C.
It relates to a crystalline copolyamide in the range of 40 ° C. The copolymerization ratios by weight of 6T / 6I, 6T / 66 and 6T / 6 are 45/55, 20/80 and 4, respectively.
When the amount of 6T is less than 0/60, the polyamide properties are not sufficiently exhibited in terms of heat resistance and water absorption. Also, 6T /
When the copolymerization ratio of 6I, 6T / 66 and 6T / 6 is larger than 80/20, 80/20 and 90/10, respectively, the amount of 6T is higher, the polymer melting point is higher and the heat resistance is improved, but the processing temperature is higher. The polymer is prone to thermal decomposition.
A system of three or more components such as 66 / 6T / 6I may be selected as necessary.

When a diamine having 12 carbon atoms is used for the semi-aromatic crystalline polyamide (hereinafter, the binding unit with terephthalic acid is referred to as 12T), a homopolymer with terephthalic acid, a hexamethylene adipamide unit, dodeca A 12T-containing polyamide obtained by copolymerizing repeating units such as a methylene adipamide unit, a hexamethylene isophthalamide unit, a dodecamethylene isophthalamide unit, a dodecamethylene isophthalamide unit, a caproamide unit is preferably used.

There is no particular limitation on the degree of polymerization of the polyamide, which is the object of the production method of the present invention, and the relative viscosity (ηr) of a 1% concentrated sulfuric acid solution at 25 ° C. is usually 1.8 to 8.
Those at 0 can be used arbitrarily.

The phosphorus-based catalyst of the present invention has a catalytic function for the polymerization reaction, and is, for example, hypophosphite, phosphate, hypophosphorous acid, phosphoric acid, phosphoric acid ester, polymetaphosphoric acid, polyphosphoric acid. Acids, phosphine oxides, phosphonium halogen compounds and the like are preferable, and hypophosphite, phosphate, hypophosphorous acid and phosphoric acid are particularly preferably used. As the hypophosphite, for example, sodium hypophosphite, potassium hypophosphite, calcium hypophosphite, magnesium hypophosphite, aluminum hypophosphite, vanadium hypophosphite, manganese hypophosphite, Zinc hypophosphite, lead hypophosphite, nickel hypophosphite, cobalt hypophosphite, ammonium hypophosphite and the like are preferred, sodium hypophosphite, potassium hypophosphite, calcium hypophosphite, next Magnesium phosphite is 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. As the phosphoric acid ester, for example,
Examples 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. As phosphine oxides,
Examples include hexamethylphosphoramide.

The amount of the phosphorus-based catalyst added is preferably 0.0001 to 5 parts by weight, more preferably 0.001 to 1 part by weight, based on 100 parts by weight of the polyamide. Also,
The time of addition may be any time as long as the degree of polymerization is increased, but it is preferably from the time of charging the monomer to the completion of the primary condensate synthesis step described later. Further, for example, it may be added many times such that it is added both when the raw materials are charged and when the concentration step is completed. Further, it may be added additionally when the degree of polymerization is increased.

As the raw material supplied to the extruder of the present invention, a primary condensation product of polyamide is preferably used. The relative viscosity of this 1% concentrated sulfuric acid solution at 25 ° C was 1.0.
It is preferably 4 to 2.5, more preferably 1.08 to 2.3, and particularly preferably 1.08 to 2.1. If the relative viscosity is less than 1.04, the polymerization time for increasing the degree of polymerization by melting becomes long, and the relative viscosity is 2.5.
If it exceeds, the melt viscosity of the primary condensate becomes high, and ejection failure may occur. The water content of the primary condensate is 0% by weight or more and 20% by weight or less, preferably 10% by weight or less, and more preferably 5% by weight or less. 20% by weight
If it exceeds, the stability of high polymerization degree decreases.

The apparatus for producing the primary condensate is not particularly limited, and a known apparatus such as a batch reaction kettle or a 1 to 3 tank type continuous reaction apparatus can be used.

The primary condensate polymerization step is carried out under stirring conditions in 15
It is carried out by heating to a temperature in the range of 0 ° C to 350 ° C. The reaction temperature must be 150 ° C to 350 ° C, preferably 180 ° C to 340 ° C, more preferably 190 ° C to 330 ° C. When the reaction temperature is lower than 150 ° C, the reaction time becomes long, which is not preferable. Further, if the reaction temperature is higher than 350 ° C, foaming occurs due to thermal decomposition of the polyamide, which is not preferable.

Next, the extruder, which is a feature of the present invention, and the method for increasing the degree of polymerization using the extruder will be described.

The extruder in the present invention may be any 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 screw segment having an L / D of 2 or less, the state of the polymer in the cylinder can be finely controlled by a screw having a short L / D, and a high quality polyamide can be obtained.

The screw segment includes a resin feed segment and a mixing segment, and a forward full flight segment is preferably used as the resin feed segment. The mixing segment includes a rotor, a notched rotor, a forward kneading, and a right angle. There are kneading, reverse kneading, kneading neutral, gear kneading, pineapple kneading, twist kneading, reverse full flight, notch flight and the like, and it is preferable to use one kind or a combination of two or more kinds. 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. The L / D of the forward full flight segment is not particularly limited, but is preferably 0.2 or more and 18 or less, more preferably 0.2 or more and 5 or less, and particularly preferably 0.3 or more 4
It is the following. L / D for segments other than forward full flight
Is preferably 0.15 or more and 5 or less, more preferably 0.2 or more and 2.5 or less, and particularly preferably 0.2 or more and 2 or less. It is effective to freely combine the screw segments.
/ D is 2 or less, preferably 0.2 or more and 2 or less, and particularly L /
It is preferable that D includes a screw segment of 0.2 or more and 1.8 or less. It is preferable to use 5% or more, preferably 10% or more and 100% or less of a screw segment having L / D of 2 or less. The total L / D of the segments other than the forward full flight is 0% or more, preferably 3% or more, more preferably 5% or more, with respect to the entire screw.
It is 70% or less, preferably 50% or less, more preferably 45% or less. 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. 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 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 in the present invention may rotate in either direction, but from the viewpoint of controlling the polymerization conditions, the twin-screw extruder preferably rotates in the same direction. The number of rotations is 50 rpm or more, preferably 70 rpm or more and 800 rpm or less, preferably 500 rpm or less. A higher 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 high, the shear heat generation will become too large, which may cause deterioration of the resin. It is preferable to select an appropriate rotation speed within the range.

The L / D of the entire screw of the twin-screw extruder in the present invention may be any value within the known range, but 10 or more, preferably 15 or more,
It is 100 or less, preferably 70 or less. If it is smaller than 10 or larger than 100, it becomes difficult to proceed the polymerization stably. It is also useful to use two or more extruders in order to efficiently proceed the polymerization.

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

The conditions for increasing the degree of polymerization by the extruder in the present invention are preferably such that the degree of polymerization is increased within a residence time range satisfying the formulas I and II while performing vacuum deaeration. Δηr ≧ 0.2 (II) t ≦ 5000 × Δηr / (T-280) (I) (t: residence time (seconds)) (Δηr: amount of change in relative viscosity due to high polymerization degree) (T: high polymerization Maximum temperature (° C.) of the resin at the time of grading) More preferably, it is within the range of the residence time that satisfies the formulas III and IV. Δηr ≧ 0.5 (III) 20 ≦ t ≦ 4000 × Δηr / (T-280) (IV) However, although the residence time has a distribution, the shortest residence time generally used in the present invention is used. Show. If more heat is applied than necessary when increasing the degree of polymerization, the physical properties will deteriorate due to thermal deterioration,
If it is too short, the degree of polymerization will not increase, so it is preferably within the range of the residence time.

The maximum temperature of the resin when the degree of polymerization is increased is the melting point or higher, preferably the melting point + 10 ° C. or higher and 370 ° C. or lower,
It is preferably 340 ° C or lower. If the temperature is too high, the thermal load is large even if the residence time is short, which is not preferable. In order to prevent thermal decomposition and thermal deterioration of the polymer, the temperature needs to be 370 ° C or lower. The temperature of the resin is controlled by the barrel temperature and the heat generated by shearing, and the barrel temperature is the melting point or higher, preferably the melting point + 10 ° C or higher and 370 ° C or lower, preferably 340 ° C or lower.

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. In addition to the vent having the degree of vacuum according to the present invention, a vent having a low degree of vacuum or an atmosphere vent may be used in combination.

Here, in addition to the method of increasing the degree of polymerization using the extruder of the present invention, the method of solid phase polymerization may be used in combination. The solid-state polymerization apparatus is not particularly limited, and any known method can be used. Specific examples of the solid-state polymerization apparatus include a kneader, a twin-screw paddle type, a tower type, a rotary drum type and a double cone type solid-state polymerization apparatus.

In the usual polymerization of polyamide, it is common to charge the raw materials so that the total amount of carboxy groups and the total amount of amino groups contained in the monomer and the dicarboxylic acid / diamine salt are equal. Then, a polyamide having a large amount of terminal carboxyl groups or terminal amino groups can be prepared by adding an excess of dicarboxylic acid component or diamine component at the time of charging the raw materials. The amount of the excess dicarboxylic acid or diamine added is 0 mol% or more, preferably 0.1%.
A range of 3 mol%, more preferably 0.5 mol% or more and 10 mol% or less, preferably 8 mol% or less, more preferably 7 mol% or less is used. Addition amount is 10 mol%
If it exceeds, 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 control agent,
Usually, a monoamine compound and a monocarboxylic acid compound are used, but acetic acid, benzoic acid and stearic acid are preferable, and acetic acid and benzoic acid are particularly preferable. The degree of polymerization modifier is 0 times or more, preferably 0.0001 times or more, and 0.1 times the moles of the constituent monomers and the total moles of the dicarboxylic acid component unit and the diamine component unit of the salt. It is used in an amount of not more than mol, preferably not more than 0.05 times mol.

A filler may be further added to the polyamide obtained in the present invention. As the filler, glass fiber or beads, talc, kaolin, wollastonite, mica, silica, alumina, diatomaceous earth, clay, gypsum, red iron oxide, graphite, titanium dioxide, zinc oxide, copper, stainless steel, etc. Examples include powdery or plate-shaped inorganic compounds, other polymer fibers (carbon fibers), and glass fibers are preferable. Particularly preferred glass fibers are glass rovings, glass chopped strands, glass yarns and the like made from strands of continuous long fibers having a diameter of about 3 to 20 μm. The blending ratio of such a filler is usually 0 part by weight or more, preferably 1 part by weight or more, relative to 100 parts by weight of the polyamide resin composition.
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
It is in the range of 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 injection-mold a thin-walled molded product, and the appearance of the molded product is deteriorated, which is not preferable. There is no particular limitation on the method of adding the filler to the polyamide resin obtained in the present invention, and any known method can be used. Specific examples of the compounding method include a method in which a filler is dry blended with polyamide pellets, and the resulting mixture is melt-kneaded with a single-screw or twin-screw extruder. Further, when the polymerization degree is increased by the melting machine, the method of adding the filler from the middle of the melting machine is preferable because of high production efficiency.

In the present invention, a catalyst, a heat resistance stabilizer, a weather resistance stabilizer, a plasticizer, a release agent, a lubricant, a crystal nucleating agent, etc. may be used in the melt polymerization, the high degree of polymerization of the melt, the compound or the molding step, etc. 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), release agents and lubricants (montanic acid and its salts, its esters, its 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, polyether sulfone, ABS resin,
SAN resin, polystyrene, acrylic resin, polyethylene, polypropylene, ethylene / α-olefin copolymer, ionomer resin, SBS, SEBS and the like).

From the viewpoint of productivity, it is more preferable that the compounding of the additive is carried out simultaneously or continuously with the polymerization degree increasing in the melting machine.

The polyamide obtained in the present invention is useful for fibers, films, molded articles and the like, and its composition is
Switches, ultra-small slide switches, DIP switches, switch housings, lamp sockets, binding bands, connectors, connector housings, connector shells, IC sockets, coil bobbins, bobbin covers, relays, relay boxes, capacitor cases, motors
Internal parts, small motor case, gear cam, dancing pulley, spacer, insulator, fastener, buckle, wire clip, bicycle wheel, caster, helmet, terminal block, power tool housing, starter insulation, spoiler, canister , Radiator tank, chamber tank, reservoir tank, fuse box, air cleaner case, air conditioner fan, terminal housing, wheel cover, intake / exhaust pipe, bearing retainer, cylinder head cover, intake manifold, water pipe impeller, engine roll damper, clutch release , Speaker diaphragm, heat-resistant container, microwave oven parts, rice cooker parts, printer ribbon guide, double-sided adhesive tape between IC chips, For electrical / electronic related parts such as double-sided adhesive tape of C and lead, automobile / vehicle related parts, home / office electric product parts, computer related parts, facsimile / copier related parts, machine related parts, and various other applications It is valid.

[0041]

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) Using DSC (PERKIN-ELMER7 type), samples 8 to 10
Let (T) be the temperature at which the maximum value of the melting curve obtained by measuring mg at a heating rate of 20 ° C./min. Sample 8-
10 mg is heated at a temperature rising rate of 20 ° C / min to obtain T + 20 ° C.
For 5 minutes, and then at a temperature decrease rate of 20 ° C / min for 30 minutes.
After cooling to ℃, holding at 30 ℃ for 5 minutes, then again at 20 ℃
Heat to T + 20 ° C. at a heating rate of / 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) Color tone Y using a color computer manufactured by Suga Test Instruments Co., Ltd.
The I value was measured. 5) Tensile Strength and Tensile Elongation Measured according to ASTM D638. 6) Flexural strength and flexural modulus It was measured according to ASTM D790. 7) Chemical resistance (LLC resistance) ASTM No. 1 dumbbell is 50% by weight of LLC (Toyota genuine long life coolant, manufactured by Toyota Motor Corporation)
After being immersed in an aqueous solution and treated in an autoclave at 130 ° C. for 500 hours, the tensile strength was measured according to ASTM D638.

Each embodiment will be described below. The reaction conditions and characteristics are shown in Tables 1 and 2, and the addition amount of monocarboxylic acid is shown therein. This amount means the amount (double mole) with respect to the number of moles of the monomer of the constituent component and the total number of moles of the dicarboxylic acid component unit and the diamine component unit of the salt.

Example 1 A total of 30 kg of hexamethylene ammonium adipate (66 salt), terephthalic acid, hexamethylene diamine, acetic acid, ion-exchanged water and sodium hypophosphite is shown in Table 1.
Was charged in a batch type pressure polymerization kettle of 0.10 m ³ at a raw material composition ratio of 0.10 m ³ and sufficiently replaced with nitrogen.
The temperature was raised to ° C, and the mixture was concentrated under stirring with a pressure of 4.0 kg / cm ² -G to a concentration of 80% by weight. 3.5 hours under stirring
Over 230 ° C., polymerization pressure 15 kg / cm 2
G. The reaction was completed by maintaining the temperature at 230 ° C to 235 ° C for 30 minutes. The discharge was performed over a period of 1 hour while supplying ion-exchanged water at a rate of 3 l / hr (unit: liter / hour) by a metering pump and maintaining the water vapor pressure at 12 kg / cm ² -G. The viscosity of this primary condensate is η
r = 1.2, melting point was 270 ° C. primary condensation product.

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 30 mmφ vent type twin-screw extruder (L / D = 4
5.5), rotating in the same direction, deep groove type. Also, the screw is composed of forward full flight with L / D of 2 or less and 100% of the segments other than forward full flight,
Segments other than forward full flight (L / D = 0.5 to 1
Order kneading, reverse kneading, reverse full flight,
The combination of seal rings) is 30% of that, and 3
It was used by dividing it into three parts. Dwell time 95 seconds,
From L / D = 5 long vent to vacuum degree-700mmHg
Was degassed, and the melt was made to have a high degree of polymerization at a screw rotation speed of 150 rpm and a maximum resin temperature of 300 ° C. Relative viscosity of polymer η
White pellets were obtained with r = 2.5 and a polymer melting point of 280 ° C. The polymerization conditions and measurement results are shown in Table 1.

Example 2 Terephthalic acid, hexamethylenediamine, ε-caprolactam and ion-exchanged water were charged in a batch type pressure polymerization kettle having a raw material composition ratio of Table 1 and a charging concentration of 0.10 m ³ .
After sufficiently substituting with nitrogen, the temperature was raised to 170 ° C., pre-concentrated to a pressure of 7.0 kg / cm ² -G and a concentration of 85 wt% under stirring, and sodium hypophosphite was added. Subsequently, the temperature was raised to 270 ° C. over 5 hours with stirring and the polymerization pressure was changed to 40 kg /
cm ² −G, and then 30 at 270 ° C. to 275 ° C.
The reaction was completed for min. The discharge was performed by supplying ion-exchanged water with a metering pump at a rate of 2 l / hr and keeping the water vapor pressure at 45 kg / cm 2 -G for 1 hour. The melting point of the obtained primary condensate is 300 ° C. and ηr is 1.
It was a primary condensate of 5.

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 30 mmφ vent type twin-screw extruder (L / D = 4
5.5), rotating in the same direction, deep groove type. Also, the screw is composed of forward full flight with L / D of 2 or less and 100% of the segments other than forward full flight,
Segments other than forward full flight (L / D = 0.5 to 1
(Combining of forward kneading, reverse kneading, orthogonal kneading, reverse full flight, and seal ring) is 30% of them, and those arranged at three positions were used. With a residence time of 75 seconds, deaeration was performed from a long vent with L / D = 5 at a vacuum degree of −700 mmHg and from a short vent with L / D = 1.8 at a vacuum degree of −650 mmHg, with a screw rotation speed of 150 rpm and a maximum resin temperature of 318 ° C. The degree of polymerization was increased by melting. White pellets having a polymer relative viscosity ηr of 2.6 and a polymer melting point of 302 ° C. were obtained. The polymerization conditions and measurement results are shown in Table 1.

Example 3 The primary condensate was polymerized according to the method of Example 1 to give a thickness of 30 mm.
The polymerization degree was increased using a φ-vent type twin-screw extruder (L / D = 45.5). Same direction rotation, shallow groove type, screw L / D is less than 2 screw segment 100
% Of the segment other than forward full flight (L / L
It consists of forward kneading with D = 1.5, reverse kneading with L / D = 0.5, and reverse full flight, and includes two reverse full flights. 13% of that portion is divided into two parts. The arranged one was used. The polymerization conditions and measurement results are shown in Table 1.

Example 4 The primary condensate was polymerized according to the method of Example 1, 20 mm
The degree of polymerization was increased by using a φ-vent type twin-screw extruder (L / D = 25). Rotation in the same direction, deep groove type, the screw has a L / D of more than 2 and a screw segment of 40%,
It consists of 60% or less screw segments 60%, and is a segment other than forward full flight (forward kneading of L / D = 0.5 to 1, reverse kneading, orthogonal kneading, reverse full flight, seal ring, kneading neat Ral) part is 15% of that, and it was used by dividing it into three parts. The polymerization conditions and measurement results are shown in Table 1.

Example 5 The primary condensate was polymerized according to the method of Example 1 to give a thickness of 20 mm.
The degree of polymerization was increased by using a φ-vent type twin-screw extruder (L / D = 25). Same direction rotation, deep groove type, screw is composed of 100% screw segment with L / D of 2 or less, and segment other than forward full flight (L / D =
The forward kneading, the reverse kneading, the orthogonal kneading, the reverse full flight, the reverse full flight, the seal ring, and the kneading needral of 0.5 to 1 are 22% of them, and the ones arranged in three places were used. The polymerization conditions and measurement results are shown in Table 1.

Example 6 A primary condensate of ηr = 1.03 was polymerized according to the method of Example 1, and the polymerization degree was increased by using the same vent type twin-screw extruder as in Example 1. The polymerization conditions and measurement results are shown in Table 1.

Example 7 A primary condensate of ηr = 2.6 was polymerized according to the method of Example 1, and the polymerization degree was increased by using the same vent type twin-screw extruder as in Example 1. The polymerization conditions and measurement results are shown in Table 1.

Example 8 The primary condensate was polymerized according to the method of Example 1 without using a phosphorus-based catalyst, and the polymerization degree was increased by using the same vent type twin-screw extruder as in Example 1. The polymerization conditions and measurement results are shown in Table 1.

Example 9 1,12-diaminododecane and terephthalic acid were equimolar (both are collectively referred to as 12T), and acetic acid, sodium hypophosphite and ion-exchanged water (30 kg in total) were used as the raw material composition shown in Table 1. 0.10m at a ratio of 60% solid content
^After being charged in a batch type pressure polymerization kettle of No. 3, nitrogen substitution was sufficiently carried out, the temperature was raised to 150 ° C. and preconcentrated to a concentration of 80% by weight at a pressure of 5.0 kg / cm ² . Continue to stir 3.
The temperature was raised to 260 ° C over 5 hours, and the polymerization pressure was 15 kg / c.
m ² -G. Further, the reaction was completed by maintaining the temperature at 260 to 265 ° C. for 30 minutes. For the discharge, ion-exchanged water was supplied by a metering pump at a rate of 3 l / hr and the water vapor pressure was adjusted to 12
It was carried out for 1 hour while maintaining the pressure at kg / cm ² -G.
The viscosity of this primary condensate is ηr = 1.50 and the melting point is 296.
It was a primary condensate at ° C. The obtained primary condensate is 100
After vacuum-drying at 24 ° C. for 24 hours, the polymerization degree was increased by using the same vent type twin-screw extruder as in Example 1. Table 2 shows the polymerization conditions and the measurement results.

Example 10 According to the method of Example 9, the primary condensate of 12T / 66 was polymerized under the conditions shown in Table 2, and the polymerization degree was increased using the same vent type twin-screw extruder as in Example 1. Table 2 shows the polymerization conditions and the measurement results.

Example 11 A 12T / 6I primary condensate was polymerized under the conditions shown in Table 2 according to the method of Example 9, and the degree of polymerization was increased using the same vent type twin-screw extruder as in Example 4. Table 2 shows the polymerization conditions and the measurement results.

Example 12 The primary condensate of nylon 66 was polymerized according to the method of Example 9, and the degree of polymerization was increased by using the same vent type twin-screw extruder as in Example 1. Table 2 shows the polymerization conditions and the measurement results.

Comparative Example 1 The same preparation as in Example 1 was carried out and the same polymerization was carried out.
The obtained primary condensate was vacuum dried at 100 ° C. for 24 hours, and then subjected to a high polymerization degree using a 20 mmφ vent type single-screw extruder using an integrated screw without a mixing zone. A residence time of 95 seconds, L / D = 1.8 from a short vent, a vacuum degree of -700 mmHg, a screw rotation speed of 150 rpm, and a maximum resin temperature of 300 ° C., but a high polymerization degree was obtained, but a polymer capable of foaming and molding was not obtained. It was Table 2 shows the polymerization conditions and the measurement results.

Comparative Example 2 The same preparation as in Example 5 was carried out and the same polymerization was carried out.
The obtained primary condensate was vacuum dried at 100 ° C. for 24 hours, and then a 15 mmφ vent type twin-screw extruder (L / D = 27) consisting of a full flight screw with L / D = 3.3.
Then, the short vent of L / D = 2 was opened, and the polymerization degree was increased at a residence time of 95 seconds, a screw rotation speed of 150 rpm, and a maximum resin temperature of 325 ° C., but a polymer capable of foaming and molding was not obtained. Table 2 shows the polymerization conditions and the measurement results.

Comparative Example 3 The same preparation as in Example 1 was carried out and the same polymerization was carried out.
The obtained primary condensate was vacuum-dried at 100 ° C. for 24 hours, and then 15 m consisting of an integrated full flight screw.
Mφ vent type twin-screw extruder (L / D = 25), L / D
= 2 short vent open, retention time 470
Second, screw rotation speed 150 rpm, maximum resin temperature 34
The degree of polymerization was increased at 0 ° C. Insoluble matter was generated in the polymer, and a polymer that could be molded was not obtained. Table 2 shows the polymerization conditions and the measurement results.

[0060]

[Table 1]

[0061]

[Table 2]

By the methods of Examples 1 to 12, polyamide resins having excellent color tone, tensile strength, flexural strength, flexural modulus and chemical resistance were obtained. Further, in Comparative Example 1 using a single-screw extruder, the degree of polymerization was not increased, and Comparative Examples 2 and 3 using a twin-screw extruder using an integral type screw were used.
When the retention time was short, the degree of polymerization did not proceed high, and when the retention time was long, insoluble matter was formed.

[0063]

EFFECT OF THE INVENTION By adopting the production method of the present invention, not only polyamide can be produced efficiently, but also color tone, tensile strength, tensile elongation, bending strength, bending elastic modulus, chemical resistance and the like are improved. As a result, it is particularly suitable as a material for electric / electronic parts and automobile parts.

Claims (22)

[Claims] 1. A method for producing a polyamide having a polymerization degree increasing step using an extruder, wherein the polymerization degree increasing step has a {screw length L} / {screw outermost diameter D} of 2 or less. A method for producing a polyamide, which comprises a step of increasing a relative viscosity of a 1% concentrated sulfuric acid solution at 25 ° C by 0.2 or more using a twin-screw extruder including a screw segment. 2. The raw material supplied to the twin-screw extruder has a relative viscosity of 1% concentrated sulfuric acid solution at 25 ° C. of 1.
The method for producing a polyamide according to claim 1, which is a primary condensate of the polyamide of 04 to 2.5. 3. L / D in the twin screw extruder
3 comprises 5 to 100% in length of screw segments having a length of 2 or less.
A method for producing the described polyamide. 4. The method for producing a polyamide according to claim 1, wherein the screw segment having an L / D of 2 or less includes a segment other than the normal full flight. 5. The method for producing a polyamide according to claim 1, wherein the polyamide is a crystalline polyamide containing a hexamethylene adipamide structure and / or a caproamide structure. 6. The method for producing a polyamide according to claim 1, wherein the polyamide is a crystalline polyamide containing an amide structure formed from an aliphatic diamine and terephthalic acid. 7. The melting point of the crystalline polyamide is 230.degree.
The method for producing a polyamide according to claim 6, wherein the temperature is in the range of 340 ° C. 8. The aliphatic diamine has 4 to 14 carbon atoms.
The method for producing a polyamide according to claim 6 or 7, wherein 9. The crystalline polyamide is a copolyamide, wherein the structural unit (I) is And at least one structural unit selected from structural units (II) to (IV): Embedded image [Chemical 4] 9. The method for producing a polyamide resin according to claim 8, which has a repeating unit consisting of 10. A method for producing a polyamide having a step of increasing the degree of polymerization using an extruder, wherein the step of increasing the degree of polymerization is carried out by using a twin-screw extruder while performing vacuum degassing, and the formula (I) is used. The method for producing a polyamide, which comprises a step of increasing the relative viscosity of a 1% concentrated sulfuric acid solution at 25 ° C. by 0.2 or more under the condition of satisfying the relationship. t ≦ 5000 × Δηr / (T-280) --- (I) (t: residence time (sec), Δηr: amount of change in relative viscosity due to high polymerization degree) 11. The method for producing a polyamide according to claim 10, wherein vacuum deaeration is performed from one or more vents at a vacuum degree of minus 500 mmHg or less. 12. The method for producing a polyamide according to claim 10, wherein the raw material supplied to the twin screw extruder is a primary condensation product of a polyamide having a relative viscosity of 1.04 to 2.5. 13. The method for producing a polyamide according to claim 10, wherein the polyamide is a crystalline polyamide having a hexamethylene adipamide structure and / or a caproamide structure. 14. The method for producing a polyamide according to claim 10, wherein the polyamide is a crystalline polyamide containing an amide structure formed from an aliphatic diamine and terephthalic acid. 15. The melting point of the crystalline polyamide is 230 ° C. or higher.
The method for producing a polyamide according to claim 14, wherein the temperature is in the range of 340 ° C. 16. The aliphatic diamine has 4 to 1 carbon atoms.
The method for producing a polyamide according to claim 14 or 15, wherein the method is 4. 17. The crystalline polyamide is a copolyamide, wherein the structural unit (I): And at least one structural unit selected from structural units (II) to (IV): [Chemical 7] Embedded image The method for producing a polyamide according to claim 16, having a repeating unit consisting of: 18. A method for producing a polyamide having a polymerization degree increasing step using an extruder, wherein the polymerization degree increasing step comprises:
Using a twin-screw extruder that includes a screw segment with {screw length L} / {outermost screw diameter D} of 2 or less, while performing vacuum deaeration while satisfying the relationship of formula (I). A process for producing a polyamide, which comprises a step of increasing the relative viscosity of a 1% concentrated sulfuric acid solution at 25 ° C. by 0.2 or more. t ≦ 5000 × Δηr / (T-280) --- (I) (t: residence time (seconds), Δηr: amount of change in relative viscosity due to increasing polymerization degree) T: maximum of resin when increasing polymerization degree Ultimate temperature (℃)) 19. A twin-screw extruder having a segment screw, wherein a screw segment having a {screw length L} / {screw outermost diameter D} of 2.0 or less,
L / D of the entire screw of the extruder is 10% or more, and the total L / D of the segments other than forward full flight is L / D.
A twin-screw extruder for polymerizing polyamide, wherein D is 3 to 70%. 20. The segments other than the forward full flight are rotor, notched rotor, forward kneading, orthogonal kneading, reverse kneading, kneading neutral, gear kneading, pineapple kneading, twist kneading, reverse kneading. 20. The twin-screw extruder for polymerization of polyamide according to claim 19, comprising two or more kinds selected from flight, notch flight, seal ring and torpedo ring. 21. The L / D of the entire screw is 10 or more and 1
20 or less, characterized in that
The described twin-screw extruder for polymerizing polyamide. 22. The twin-screw extruder for polyamide polymerization according to any one of claims 19 to 21, wherein the polyamide is a crystalline polyamide containing an amide structure formed from an aliphatic diamine and terephthalic acid. .