JP2000239375A - Polyamide with excellent stretchability - Google Patents

Abstract

(57) Abstract: Providing a polyamide excellent in stretchability, especially in sequential biaxial stretchability. An essential component is a dicarboxylic acid containing a diamine and a branched saturated carboxylic acid having 6 to 22 carbon atoms. The preferred composition is that the lactam and / or aminocarboxylic acid is 50 to 99.95 mol%, the diamine is 0.025 to 25 mol%, and the dicarboxylic acid is 0.0
A polyamide comprising 25 to 25 mol%, wherein 5 to 100 mol% of the dicarboxylic acid is a branched saturated carboxylic acid having 6 to 22 carbon atoms. 6-22 carbon atoms
As the branched saturated carboxylic acid, 1,6-decanedicarboxylic acid is preferable.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel polyamide having excellent stretchability, and is used for films, monofilaments, fibers and the like. Specifically, a polyamide containing a diamine and a dicarboxylic acid as essential components, and a part or all of the dicarboxylic acid is a polyamide composed of a branched saturated carboxylic acid having 6 to 22 carbon atoms. The present invention relates to a novel polyamide suitable for a sequentially biaxially stretched film, which has been regarded as difficult.

[0002]

2. Description of the Related Art Polyamides are widely used as food packaging materials such as retort foods because of their excellent heat resistance and gas barrier properties. In recent years, with the expansion of these food packaging applications, the required characteristics have diversified, for example, thin,
In addition, there is an increasing demand for a polyamide film having excellent mechanical strength and gas barrier properties.

[0003] Generally, a film produced from a crystalline polymer is stretched so that the film becomes thinner.
In addition, it is known that mechanical strength and gas barrier properties are improved. Utilizing this property, a stretched film having a small thickness and excellent mechanical strength is produced from a crystalline polymer. However, when a film of a crystalline polyamide such as nylon 6 or nylon 66, which is a typical polyamide, is stretched, the polyamide molecules relatively easily form hydrogen bonds between the molecules due to the stretching, whereby crystallization proceeds. Therefore, it is known that a portion which is easily stretched and a portion which is hardly stretched are formed in the film, and a phenomenon such as uneven stretching or breakage of the film occurs. Therefore, when trying to produce a uniformly stretched film from a conventional polyamide material, strictly control the temperature during stretching,
It was necessary to control the stretching conditions within a specific narrow range, such as setting a low stretching ratio or reducing the stretching speed. or,
Even when the stretching conditions are controlled in a narrow range, the stretching ratio is limited, and it has been difficult to industrially efficiently produce a stretched film.

In a method for producing a stretched film, first, a first-stage stretching (hereinafter, sometimes referred to as “primary stretching”) is performed in the extrusion direction of the film, and then the film is stretched in a direction perpendicular to the extrusion direction. The so-called sequential biaxial stretching method for performing the second-stage stretching (hereinafter, sometimes referred to as “secondary stretching”) is known as a method for producing a stretched film having good productivity and excellent characteristics. ing. When this method is applied to the production of a stretched film of polyamide, polyamide molecules are oriented in parallel to the film surface by primary stretching, hydrogen bonds are formed between polyamide molecules, and crystallization proceeds. Even if the range becomes narrow and the stretching ratio of the secondary stretching is as low as about 2 times, stretching unevenness or breakage of the film may occur, and the biaxially stretched film is manufactured sequentially in an industrially stable state. Was said to be difficult. For this reason, there is a strong demand for a polyamide material having excellent stretchability, in particular, excellent sequential biaxial stretchability with good productivity.

Conventionally, many polyamide copolymers and polyamide compositions have been proposed for the purpose of developing polyamides having improved stretchability. As a polyamide copolymer having improved stretchability, for example, JP-A-53-5250 discloses a polyamide copolymer comprising hexamethylenediamine, isophthalic acid and terephthalic acid.
No. 104312 discloses an alicyclic diamine and adipic acid,
A polyamide copolymer comprising an aliphatic dicarboxylic acid such as sebacic acid has been proposed.

[0006] As the polyamide composition, for example,
JP-A-52-104565 discloses a composition in which an aliphatic polyamide and a polyamide containing xylylenediamine as one component are blended, and JP-B-6-43552 discloses an aliphatic polyamide and an amorphous semi-aromatic. JP-A-6-263895 proposes a composition in which a polyamide is blended with a composition in which a crystalline aliphatic polyamide and an amorphous polyamide are blended.

[0007] In these proposed polyamide copolymer and polyamide blend compositions, hydrogen bonds between polyamide molecules during stretching are suppressed as compared with a single polyamide such as nylon 6, and stretchability is improved. However, when the stretching ratio is 3 times or more, stretching unevenness or breakage may occur,
There were restrictions on the draw ratio. Further, in the secondary stretching by the sequential biaxial stretching method, even if the stretching ratio was about 2 times, the stretchability was insufficiently improved, such as uneven stretching or breakage.

[0008]

SUMMARY OF THE INVENTION An object of the present invention is to provide a polyamide composition which is excellent in stretchability, in particular, sequential biaxial stretchability.

[0009]

Means for Solving the Problems In order to solve the problems of the present invention, the present inventors have intensively studied the relationship between the molecular structure of a polyamide and the extensibility, and as a result, the polyamide containing a dicarboxylic acid having a specific branch as an essential component. Found that the stretchability was good, and reached the present invention.

That is, the present invention provides a diamine and a compound having 6 to 2 carbon atoms.
It is a polyamide having excellent stretchability, comprising a polyamide containing dicarboxylic acid containing a branched saturated carboxylic acid as an essential component. Furthermore, lactam and / or aminocarboxylic acid is 50 to 99.95 mol%, and diamine is 0.025%.
~ 25mol%, dicarboxylic acid is 0.025 ~ 25mo
1% polyamide, comprising 5% of said dicarboxylic acid.
-100 mol% is a polyamide having excellent stretchability, which is a branched saturated carboxylic acid having 6 to 22 carbon atoms.

Heretofore, no knowledge has been found regarding polyamides composed of diamines and dicarboxylic acids, the polyamides comprising a dicarboxylic acid containing a branched saturated dicarboxylic acid having 6 to 22 carbon atoms as an essential component, and the properties thereof.
Further, it is not known that a polyamide containing a branched saturated carboxylic acid having 6 to 22 carbon atoms as a component is excellent in stretchability. The reason why a polyamide containing a branched saturated dicarboxylic acid having 6 to 22 carbon atoms as an essential component is excellent in stretchability, in particular, the sequential biaxial stretchability, which has conventionally been considered difficult, is not clear, but the polyamide is introduced into a polyamide molecular chain. It is presumed that the branched chains of the dicarboxylic acid affect the hydrogen bond interaction between the polyamide molecules at the time of stretching, suppress the formation of hydrogen bonds, and suppress the crystallization of the polyamide.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail.
The polyamide of the present invention contains a dicarboxylic acid containing a diamine and a branched saturated dicarboxylic acid having 6 to 22 carbon atoms as essential components. The polyamide of the present invention may be composed of two components of a diamine and a dicarboxylic acid containing a branched saturated dicarboxylic acid having 6 to 22 carbon atoms, but taking into consideration control of hydrogen bond generation between polyamide molecules and production of a film. Then, the lactam and / or the aminocarboxylic acid, the diamine, and the carbon number of 6 to 2 are obtained.
Polyamides comprising a dicarboxylic acid containing 2 branched saturated dicarboxylic acids as a constituent component are more preferred.

Specific examples of the diamine used in the present invention include ethylenediamine, tetramethylenediamine, hexamethylenediamine, undecamethylenediamine, dodecamethylenediamine, 2,2,4-trimethylhexamethylenediamine, 2,4,4 Fatty acids such as aliphatic diamines such as 4-trimethylhexamethylenediamine, bis (4-aminocyclohexyl) methane, bis (4-aminocyclohexyl) propane, 1,3-bisaminomethylcyclohexane and 1,4-bisaminomethylcyclohexane Examples thereof include aromatic diamines such as cyclic diamine, meta-xylylenediamine and para-xylylenediamine, and these diamines may be used alone or in combination of two or more.

Specific examples of the branched saturated dicarboxylic acid having 6 to 22 carbon atoms used in the present invention are 1,6-decanedicarboxylic acid (sometimes referred to as "2-butyloctadionic acid"). , 3-dibutylbutanedonic acid, 8-ethyloctadecanedioic acid, 8,13-dimethyleicosadonic acid, 2-octylundecandioic acid, 2-nonyldecanedioic acid, and the like. These may be used alone or two or more weeks may be used in combination as appropriate, but 1,6-decanedicarboxylic acid is preferably used. The branched saturated dicarboxylic acid having 6 to 22 carbon atoms can be produced by a known method, for example, oxidative decomposition of cyclohexane, hydrolysis of 7-cyanoundecanoic acid, hydroformylation of unsaturated carboxylic acid such as oleic acid, Koch-carboxylation, It is produced by a method such as Reppe-carboxylation.

Specific examples of the dicarboxylic acids used in addition to the branched saturated dicarboxylic acids having 6 to 22 carbon atoms include aliphatic dicarboxylic acids such as adipic acid, suberic acid, azelaic acid, sebacic acid and dodecanoic acid; Alicyclic dicarboxylic acids such as 4-dicarboxycyclohexane; and aromatic dicarboxylic acids such as isophthalic acid, terephthalic acid, and naphthalenedicarboxylic acid. These dicarboxylic acids may be used alone or in an appropriate combination of two or more. The proportion of the branched saturated dicarboxylic acid having 6 to 22 carbon atoms in the dicarboxylic acid is 5-1.
00 mol%, preferably 10 to 100 mol%. If the proportion of the branched saturated dicarboxylic acid having 6 to 22 carbon atoms is less than the above lower limit, the effect of improving stretchability is reduced. In addition, when it is more than the upper limit, the stretchability is improved,
Practical properties such as mechanical strength may be reduced. Even when the amount of the branched saturated dicarboxylic acid having 6 to 22 carbon atoms used is small, the effect of improving the stretchability is large. The diamine and the dicarboxylic acid containing a branched saturated dicarboxylic acid having 6 to 22 carbon atoms are used in an approximately equimolar ratio.
The diamine and dicarboxylic acid may be used as they are, or a nylon salt obtained by a known method from diamine and dicarboxylic acid may be used.

Specific examples of the lactam used in the present invention include:
α-pyrrolidone, ε-caprolactam, ω-enantholactam, α-piperidone, ω-undecanelactam, ω
-Dodecanolactam and the like. Specific examples of aminocarboxylic acids include 6-aminocaproic acid, 7-aminoheptanoic acid, 8-aminooctanoic acid, 9-aminononanoic acid,
10-aminocapric acid, 11-aminoundecanoic acid,
12-aminododecanoic acid and the like. These lactams and aminocarboxylic acids may be used alone or in an appropriate combination of two or more.

When the polyamide of the present invention comprises a lactam and / or an aminocarboxylic acid, a diamine and a dicarboxylic acid containing a branched saturated dicarboxylic acid having 6 to 22 carbon atoms, the constituent ratio of the lactam and / or the aminocarboxylic acid is 50 to 99.95 mol based on the entire polyamide
%, Preferably 70 to 99.95 mol%. Diamine is 0.025 to 25 mol based on the entire polyamide.
1%, preferably 0.025 to 15 mol%, and a dicarboxylic acid containing a branched saturated dicarboxylic acid having 6 to 22 carbon atoms is contained in an amount of 0.025 to 25 mol% based on the entire polyamide.
mol%, preferably 0.025 to 15 mol%. The ratio of the branched saturated dicarboxylic acid having 6 to 22 carbon atoms in the dicarboxylic acid is 5 to 100 mol%, preferably 10 to 100 mol%. When the use amount of the lactam and / or aminocarboxylic acid is less than the above lower limit, the mechanical strength is reduced or the film is difficult to form. On the other hand, when it is more than the above upper limit, the stretchability is reduced.

The polyamide of the present invention is produced by a known batch production method or continuous production method. As manufacturing equipment,
Batch type reactor, single tank type or multi-layer type continuous reactor,
Known polyamide production apparatuses such as a kneading reaction extruder such as a tubular continuous reaction apparatus, a single-screw kneading extruder, and a twin-screw kneading extruder can be used. As a polymerization method, melt polymerization,
Known methods such as solution polymerization and solid state polymerization can be used. These polymerization methods can be used alone or in an appropriate combination.

For example, the above-mentioned raw materials and water are charged into a pressure-resistant container, subjected to polycondensation in a sealed state at a temperature of 200 to 350 ° C. under pressure, and then the pressure is reduced to 200 to 350 ° C. under atmospheric pressure or reduced pressure. Perform a polymerization reaction in a temperature range of 350 ° C.,
By increasing the molecular weight, the desired polyamide can be produced. The water used in the polycondensation is preferably ion-exchanged water or distilled water from which oxygen has been removed, and the amount used is generally 1 to 150 parts by weight based on 100 parts by weight of the raw material constituting the polyamide. It is. Further, the diamine as the raw material and the dicarboxylic acid containing the branched saturated dicarboxylic acid having 6 to 22 carbon atoms may be directly charged in a pressure-resistant container,
Alternatively, a nylon salt formed by mixing and dissolving diamines having substantially equal mols and a dicarboxylic acid containing a branched saturated dicarboxylic acid having 6 to 22 carbon atoms in water or alcohol may be used.

The high molecular weight polyamide is withdrawn from the pressure vessel, cooled with water or the like, and then pelletized.
When ε-caprolactam and / or aminocaproic acid are used as raw materials, unreacted monomers and the like remain in the obtained polyamide, and the unreacted monomers and the like are further removed by hot water washing or the like. The molecular weight of the polyamide of the present invention is in the range of 1.5 to 5.0, preferably 2.0 to 4.0, as indicated by the relative viscosity (ηr) measured by the method described in JIS K6810. There are no particular restrictions on the types of terminal groups of this polyamide, its concentration or molecular weight distribution.

In the polymerization of the polyamide of the present invention, if necessary, phosphoric acid, phosphorous acid, hypophosphorous acid, polyphosphoric acid and the like can be added to promote polymerization and prevent deterioration. The addition amount of these phosphorus compounds is usually 50 to 3,000 ppm based on the polyamide to be obtained. In addition, to control the molecular weight and stabilize the melt viscosity during molding, amines such as laurylamine, stearylamine, hexamethylenediamine, meta-xylylenediamine, acetic acid, benzoic acid, hexanedioic acid, and isophthalic acid are used as molecular weight regulators. Carboxylic acids such as acid and terephthalic acid can be added. The amount of use of these molecular weight regulators varies depending on the reactivity of the molecular weight regulator and the polymerization conditions, but is appropriately determined so that the relative viscosity of the polyamide finally obtained is in the range of 1.5 to 5.0. .

The film can be produced from the polyamide of the present invention by a known film production method, for example, a T-die method using a melt extruder, an inflation method, a tubular method, a solvent casting method, a hot press method, and the like. For example, the polyamide of the present invention, if necessary, after adding a lubricant or slip agent such as calcium stearate, a bisamide compound, silica, and talc, is supplied to a melt extruder equipped with a T-die, and has a melting point of the polyamide of 320 or more. ℃ or less,
Preferably, the film is produced by melt-extrusion at a temperature from 10 ° C. higher than the melting point of the polyamide to 300 ° C. and cooling with a cooling roll controlled at 0 to 100 ° C. The stretching of the film can be carried out as a continuous step following the production of the film, or the film can be wound once and then stretched in another step.

In the production of the film by the sequential biaxial stretching method, a lubricant such as calcium stearate, a bisamide compound, silica, talc or a slip agent is added to the polyamide of the present invention, if necessary, and then a T-die is provided. The polyamide is melt-extruded by a melt extruder to form an unstretched film. The unstretched film may be continuously stretched in a continuous process, or may be wound up and then stretched. In the sequential biaxial stretching method, the film is stretched in the extrusion direction, that is, the primary stretching is performed at a temperature equal to or higher than the glass transition temperature (hereinafter, referred to as “Tg”) of the polyamide used, usually from Tg to
In the temperature range of (Tg + 50) ° C, the stretching ratio is 2 to 5 times,
Preferably, the step of stretching 2.5 to 4 times, stretching in the direction perpendicular to the extrusion direction, that is, the secondary stretching is at or above the temperature at the time of primary stretching, usually (temperature at the time of primary stretching) to (primary stretching). Stretching temperature in the temperature range of 20 ° C. higher than the temperature at the time of stretching)
It is carried out by a step of stretching 5 times, preferably 2.5 to 4 times, and a step of performing heat setting of the secondary stretched film in a temperature range of 120 ° C. or more and the melting point of the polyamide or less.

As long as the effects of the present invention are not impaired, a heat stabilizer, an ultraviolet absorber, a light stabilizer,
Antioxidants, antistatic agents, tackifiers, sealant improvers, antifoggants, release agents, impact modifiers, plasticizers, pigments,
Dyes, fragrances, reinforcing materials and the like can be added.

The polyamide of the present invention is suitable for a film, particularly a film material for stretching such as a uniaxially stretched film, a simultaneous biaxially stretched film and a sequential biaxially stretched film, and is particularly suitable as a material for a sequentially biaxially stretched film. is there.
It can also be used preferably for monofilaments or fibers whose properties can be improved by stretching. Monofilaments and fibers can be produced at a temperature not lower than the melting point of the polyamide used and not higher than 320 ° C. by a known melt spinning method.
Further, the polyamide of the present invention can be used for the production of molded articles by injection molding, compression molding, vacuum molding or the like.

[0026]

The present invention will be described below in detail with reference to examples and comparative examples. The measured values shown in the examples and comparative examples were measured by the following methods.

1) Measurement of ηr (Relative Viscosity) of Polyamide According to JIS K6810, 98% by weight of concentrated sulfuric acid is used as a solvent at a polyamide concentration of 1% by weight and at a temperature of 25 ° C. using an Ubbelohde viscometer. It was measured.

2) Measurement of the degree of orientation of all molecular planes when the film is stretched (primary stretching) in the extrusion direction of the film A biaxial stretching machine BIX-703 whose temperature is controlled to a predetermined atmospheric temperature (50 ° C., 60 ° C., 70 ° C.). An unstretched sample film having a length of 92 mm and a width of 92 mm was attached to a mold (manufactured by Iwamoto Seisakusho) stretching tank, preheated at ambient temperature for 20 seconds, and then 3.2 mm at a deformation rate of 35 mm / sec in the extrusion direction of the film.
The film is stretched twice and heat-set at 200 ° C. to prepare a test film for measuring the total molecular plane orientation degree. The refractive index (Nx) in the stretching direction, the refractive index (Ny) in the width direction, and the refractive index (Nz) in the thickness direction of this film were measured using an automatic birefringence meter KOBRA-2.
It was measured with a 1ADH type (manufactured by Oji Scientific Instruments), and the total molecular plane orientation (P) was determined by equation (1).

P = {(Nx + Ny) / 2} −Nz (1) (where P is the total molecular plane orientation of the stretched film, Nx is the refractive index in the stretching direction of the film, and Ny is the width in the width direction of the film). (The refractive index and Nz indicate the refractive index in the thickness direction.) The smaller the value of P, the smaller the orientation of the polyamide molecules and the better the stretchability.

3) Measurement of breaking ratio at the time of secondary stretching by sequential biaxial stretching method Biaxial stretching machine BIX whose atmosphere temperature was adjusted to 60 ° C.
-703 type (Iwamoto Seisakusho) stretching tank, attach the sample film, preheat at ambient temperature for 20 seconds, then stretch in the extrusion direction of the film to 3.0 times at the deformation speed of 35 mm / sec (primary stretching) ) Was performed, and the stretching was performed in a direction perpendicular to the extrusion direction at a deformation speed of 35 mm / sec until the secondary stretching was broken, and the stretching ratio at the time of breaking was measured.

Example 1 2200 g of ε-caprolactam, 22.8 g of hexamethylene diamine were placed in a 5-liter pressure vessel equipped with a stirrer, a thermometer, a pressure gauge, a pressure controller and a polymer outlet.
45.2 g of 1,6-decanedicarboxylic acid and distilled water 1
19 g was charged, nitrogen pressurization and depressurization were repeated several times, and the pressure inside the pressure vessel was replaced with nitrogen, and the temperature was raised to 240 ° C. 24
After reacting at 0 ° C. with stirring for 4 hours, the temperature was raised to 270 ° C., and then released to a gauge pressure of 0 kg / cm ² · G over 2 hours. The mixture was reacted at a temperature of 6 ° C. with stirring for 6 hours. Next, the stirring was stopped, the polyamide in a molten state was withdrawn in a string form from the polymer outlet, cooled with water, and then pelletized,
1780 g of pellets were obtained. 90 ~ 9
After washing under flowing hot water at 5 ° C for several hours,
Vacuum dried for hours. Ηr of the obtained polyamide is 3.4.
It was 3. 1500 g of this polyamide was mixed with 0.45 g of calcium stearate and supplied to a melt extruder equipped with a coat hanger type T die. It was melted at 260 ° C. and extruded on a cooling roll controlled at about 40 ° C. to form an unstretched film having a thickness of 120 μm. The unstretched film was stored in an aluminum bag so as not to absorb moisture until the stretchability was evaluated. 92m long from this unstretched film
m, 92 mm wide sample was cut out, and a biaxial stretching machine BIX-7 was used.
Type 03 (manufactured by Iwamoto Seisakusho) at ambient temperature of 50 ° C
After preheating for 0 second, the stretching speed is 35 mm / sec at the same temperature.
In step c, the film was primarily stretched 3.2 times in the extrusion direction to prepare a stretched film. In the same manner, a stretched film that was primarily stretched at an ambient temperature of 60 ° C. and 70 ° C. was prepared. The orientation degree of all molecular planes of the obtained stretched film was measured, and the results are shown in Table 1.
Further, the film primarily stretched at 60 ° C. to a stretch ratio of 3.0 was further subjected to secondary stretching at the same temperature in a direction perpendicular to the extrusion direction at a stretching speed of 35 mm / sec until breaking. The stretching ratio at the time of breaking was 4.3 times.

Example 2 Hexamethylenediamine, 1,6-decanedicarboxylic acid and distilled water were charged in 7.45 g and 14.3 g, respectively.
A polyamide was obtained in the same manner as in Example 1 except that the amount was changed to 8 g and 117 g. Ηr of this polyamide was 3.47. A stretched film formed by molding and primary stretching from this polyamide in the same manner as in Example 1 was measured for the degree of total molecular plane orientation. The results are shown in Table 1. Further, the film which was primarily stretched at a stretching ratio of 3.0 at 60 ° C. was further stretched at the same temperature in a direction perpendicular to the extrusion direction at a stretching speed of 35 mm / sec until the film was broken. The stretching ratio at break was 3.0 times.

Comparative Example 1 A polyamide (nylon 6) was prepared in the same manner as in Example 1 except that 2200 g of ε-caprolactam and 116 g of distilled water were charged and hexamethylenediamine and 1,6-decanedicarboxylic acid were not used. ) Got. Ηr of this polyamide was 3.57. A stretched film formed by molding and primary stretching from this polyamide in the same manner as in Example 1 was measured for the degree of total molecular plane orientation. Table 1 shows the results.
It was shown to. Further, the film which was primarily stretched at a stretching ratio of 3.0 at 60 ° C. was further stretched at the same temperature in a direction perpendicular to the extrusion direction at a stretching speed of 35 mm / sec until the film was broken. The stretching ratio at break was 1.3 times.

Comparative Example 2 Using adipic acid instead of 1,6-decanedicarboxylic acid, 2200 g of ε-caprolactam, 30.1 g of hexamethylenediamine, 38.9 g of adipic acid and distilled water 11
A polyamide (copolymer of nylon 6 and 66) was obtained in the same manner as in Example 1 except that 9 g was charged. Ηr of this polyamide was 3.50. A stretched film formed by molding and primary stretching from this polyamide in the same manner as in Example 1 was measured for the degree of total molecular plane orientation.
The results are shown in Table 1. Further, at 60 ° C., a draw ratio of 3.
The film that was primarily stretched to 0 times was further stretched at the same temperature in a direction perpendicular to the extrusion direction at a stretching speed of 35 mm / sec until the film was broken. The stretch ratio at break was 2.5 times.

Example 3 In place of hexamethylenediamine of Example 1, 2,2,4
1: 1 molar ratio of trimethylhexamethylenediamine and 2,4,4-trimethylhexamethylenediamine
Was carried out in the same manner as in Example 1 except that 31.7 g of the mixture was used and 68.5 g of 8-ethyloctadecanedioic acid was used instead of 1,6-decanedicarboxylic acid to obtain a polyamide. Ηr of this polyamide was 3.55. A stretched film produced from this polyamide in the same manner as in Example 1 and subjected to primary stretching was measured for the degree of orientation at all molecular planes. Table 1 shows the results. In addition, the film that was primarily stretched at a stretching ratio of 3.0 at 60 ° C. was secondarily stretched at the same temperature in a direction perpendicular to the extrusion direction at a stretching speed of 35 mm / sec until breaking. The stretch ratio at break was 3.6 times.

Example 4 In place of hexamethylenediamine of Example 1, 2,2,4
1: 1 molar ratio of trimethylhexamethylenediamine and 2,4,4-trimethylhexamethylenediamine
Was mixed with 31.7 g, and 8,13-dimethyleicosadonic acid was replaced with 74.0 in place of 1,6-decanedicarboxylic acid.
A polyamide was obtained in the same manner as in Example 1 except that g was used. Ηr of this polyamide was 3.39.
The total molecular plane orientation of a film formed from this polyamide by molding and primary stretching in the same manner as in Example 1 was measured. Table 1 shows the results. In addition, the film that was primarily stretched at a stretching ratio of 3.0 at 60 ° C. was secondarily stretched at the same temperature in a direction perpendicular to the extrusion direction at a stretching speed of 35 mm / sec until breaking. The stretch ratio at break was 3.9 times.

[0036]

[Table 1]

Example 5 A polyamide obtained in the same manner as in Example 1 was extruded at a cylinder temperature of 280 ° C. using a CS-40-26N type melt extruder manufactured by Uniplus Corporation to obtain a monofilament having a diameter of 2 mm. Obtained. The monofilament was attached to a manual stretching machine, preheated in a heating furnace at an atmosphere temperature of 60 ° C. for 5 minutes, and then stretched at the same temperature and a stretching speed of 5 mm / sec. This operation was repeated five times, but the film could be stretched without cutting even 5.5 times in all five times.

Comparative Example 3 Using a polyamide obtained in the same manner as in Comparative Example 1, a monofilament having a diameter of 2 mm was extruded at a cylinder temperature of 280 ° C. using a CS-40-26N type melt extruder manufactured by Uniplus. Obtained. The monofilament was attached to a manual stretching machine, preheated in a heating furnace at an atmosphere temperature of 60 ° C. for 5 minutes, and then stretched at the same temperature and a stretching speed of 5 mm / sec. This operation was repeated 5 times, and all were broken at a stretch ratio of 3.7 to 4.6.

Example 6 1440 g of 6-aminocaproic acid, 348 g of hexamethylenediamine, were placed in a 5-liter pressure-resistant vessel equipped with a stirrer, thermometer, pressure gauge, pressure control device and polymer outlet.
A polyamide was obtained in the same manner as in Example 1 except that 517.5 g of 1,6-decanedicarboxylic acid, 109.5 g of adipic acid and 86 g of distilled water were charged. Ηr of this polyamide was 3.32. A film was formed from this polyamide in the same manner as in Example 1 and subjected to primary stretching at 60 ° C. to a stretching ratio of 3.0, and then broken at the same temperature in a direction perpendicular to the extrusion direction at a stretching speed of 35 mm / sec. Stretched. The stretching ratio at break was 4.8 times.

[0040]

EFFECTS OF THE INVENTION A polyamide containing diamine and dicarboxylic acid containing a branched saturated carboxylic acid having 6 to 22 carbon atoms as essential components, in particular, 50 to 99.95 mol% of lactam and / or aminocarboxylic acid and 0 of diamine. .025
25 mol%, 0.025 to 25 mol of dicarboxylic acid
% Of the dicarboxylic acid,
A polyamide in which 100 mol% is 1,6-decanedicarboxylic acid has good stretchability and is suitable as a material for a stretched film, particularly, a polyamide film for sequential biaxial stretching.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4D006 GA41 MA03 MB16 MB19 MB20 MC54X MC55X MC89 NA35 NA36 PA10 PC11 4J001 DA01 DB01 DB04 EA02 EA04 EA05 EA06 EA08 EA13 EA15 EA16 EA17 EB08 EB09 EB13 EB14 EC46 EB37 EC46 EC14 EC16 EC47 EC48 FA01 FA03 FB03 FB05 FC03 FC05 FD01 GA12 JA12 JB29 JB50 JC01 4L035 HH10

Claims (4)

[Claims] 1. A polyamide excellent in stretchability, comprising a polyamide comprising diamine and a dicarboxylic acid containing a branched saturated carboxylic acid having 6 to 22 carbon atoms as an essential component. 2. A lactam and / or aminocarboxylic acid having a content of 50 to 99.95 mol% and a diamine having a content of 0.025 to 2
5 mol%, dicarboxylic acid is 0.025 to 25 mol%
A polyamide consisting of 5 to 1 of the dicarboxylic acid
2. The stretchable polyamide according to claim 1, wherein 00 mol% is a branched saturated carboxylic acid having 6 to 22 carbon atoms. 3. The carbon number of 6 or more according to claim 1 or 2.
The stretchable polyamide according to claim 1, wherein the 22 branched saturated carboxylic acid is 1,6-decanedicarboxylic acid. 4. A uniaxially stretched film, a simultaneous biaxially stretched film or a sequential biaxially stretched film produced from any of the polyamides according to claim 1.