JP2000336167A - Polyamide with excellent orientation tendency - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject polyamide, in particular suitable for sequential biaxial orientation process. SOLUTION: This polyamide is composed of 50-99.8 mol% of lactam and/or aminocarboxylic acid unit, 0.1-25 mol% of dicarboxylic acid unit and 0.1-25 mol% of diamine unit; wherein a 6-22C branched-type saturated diamine accounts for 10-100 mol% of the above diamine.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a novel polyamide having excellent stretchability. More specifically, the present invention relates to a polyamide using a branched saturated diamine having 6 to 22 carbon atoms for part or all of the diamine, and relates to a novel polyamide suitable for a stretched film, particularly, a successively biaxially stretched film.

[0002]

2. Description of the Related Art Polyamides are used as food packaging materials such as retort foods because of their excellent heat resistance and gas barrier properties. In recent years, required characteristics have been diversified with the expansion of these food packaging applications. For example, there is a demand for a polyamide suitable for producing a thin film having practical mechanical strength and gas barrier properties, and a polyamide suitable for a sequential biaxial stretching method with good productivity.

In general, it is known that, by stretching a film obtained from a crystalline polymer, the thickness of the film is reduced and the mechanical strength per unit is improved. Applying this stretching technique, thin films having high mechanical strength are produced from many crystalline polymers. However, it is known that, if films, monofilaments, fibers and the like obtained from crystalline polyamides such as nylon 6 and nylon 66 are not controlled in a certain narrow range, uneven drawing or breakage occurs. In particular, when producing a film by the sequential biaxial stretching method which is considered to be advantageous for mass production, in the first stretching, the polyamide molecules are oriented parallel to the film surface, forming hydrogen bonds between the molecules, It is known that the crystallization proceeds and the film becomes hard, so that the second-stage stretching becomes difficult. Therefore, a polyamide having improved stretchability that can be easily applied to the sequential biaxial stretching method is desired.

Heretofore, there have been many proposals for improving the stretchability of polyamide. For example, Japanese Unexamined Patent Publication (Kokai) No. 52-104565 discloses that a blend of an aliphatic polyamide and a polyamide comprising xylylenediamine and α, ω-aliphatic dicarboxylic acid is melt-molded to obtain a film having a plane orientation index. Is stretched in the first step (also referred to as “primary stretching”) so that the film thickness becomes 0.6 to 1.5, and the film is subjected to second-stage stretching (also referred to as “secondary stretching”). Has been proposed. Japanese Patent Publication No. 55-419
No. 01 discloses an aliphatic polyamide, another polyamide compatible with the polyamide and a nucleating agent in an amount such that the isothermal crystallization parameter is 1.1 to 2.5, and the plane orientation index is adjusted. There has been proposed a method for producing a sequentially biaxially stretched film in which the film is first stretched to 0.6 to 1.5 and then secondarily stretched. JP-B-62-25704 discloses an aliphatic polyamide and 2,2,4-trimethyl-1,
6-hexamethylenediamine and / or 2,4,4-
There has been proposed a method for producing a stretched film obtained by blending trimethyl-1,6-hexamethylenediamine and a polyamide comprising an aromatic and / or alicyclic dicarboxylic acid at a specific ratio. 6-435
No. 52 discloses a biaxially stretched film obtained from a blend of a copolymerized polyamide composed of an aliphatic polyamide and a semi-aromatic polyamide, an aliphatic diamine and a semi-aromatic polyamide composed of isophthalic acid and / or terephthalic acid. Polyamide compositions have been proposed.

Conventionally, the stretchability of a proposed polyamide composition or the like is improved as compared with a single polyamide such as nylon 6. However, when the stretching ratio of the film is 3 times or more, stretching unevenness sometimes occurs, and there is a limit to the stretching ratio that can be favorably stretched. Further, when the second-stage stretching (secondary stretching) in the sequential biaxial stretching method, that is, when stretching is performed in a direction perpendicular to the stretching direction of the primary stretching, stretching unevenness is likely to occur or the film is broken at a low stretching ratio. In some cases, improvement in stretchability was not sufficient.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to provide a polyamide having excellent stretchability, and particularly suitable for a sequential biaxial stretching method.

[0007]

Means for Solving the Problems The present inventors have proposed stretchability,
In particular, as for the polyamide excellent in the sequential biaxial stretching property, as a result of intensive studies on the relationship between the molecular structure of the polyamide and the stretching property, as a necessary component of the diamine, the diamine has 6 to 2 carbon atoms.
The present inventors have found that a polyamide produced by using the branched saturated diamine of No. 2 is a polyamide having good sequential biaxial stretching properties to achieve the object of the present invention, and reached the present invention.

That is, the first invention of the present invention comprises a unit composed of a lactam and / or an aminocarboxylic acid, a unit composed of a dicarboxylic acid, and a unit composed of a diamine containing a branched saturated diamine having 6 to 22 carbon atoms. It is a polyamide with excellent stretchability.

The second invention relates to the above-mentioned diamines of 10 to 1
The polyamide having excellent stretchability according to the first invention, wherein 00 mol% is a branched saturated diamine having 6 to 22 carbon atoms.

[0010] A third invention relates to a lactam and / or an aminocarboxylic acid of 50 to 99.8 mol%, a diamine of 0.1 to 10 mol%.
A polyamide comprising 25 mol% of dicarboxylic acid and 0.1 to 25 mol% of dicarboxylic acid,
ol% is a polyamide having excellent stretchability, which is a branched saturated diamine having 6 to 22 carbon atoms.

It is not clear why polyamides having a branched saturated diamine having 6 to 22 carbon atoms as structural units are excellent in stretchability, in particular, sequential biaxial stretchability, which has heretofore been considered difficult. It is presumed that the branching of the diamine unit introduced into the film weakens the hydrogen bond interaction between the polyamide molecules at the time of stretching, suppresses the orientation of the polyamide molecules in the film plane, and suppresses the crystallization. This indicates that, when comparing the total molecular plane orientation of films having substantially the same stretch ratio obtained from the polyamide of the present invention and nylon 6 containing a branched saturated diamine having 6 to 22 carbon atoms as an essential component, It is presumed as described above from the fact that the polyamide has lower plane orientation of molecules.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail.
The polyamide of the present invention contains a unit composed of a lactam and / or an aminocarboxylic acid, a unit composed of a dicarboxylic acid, and a diamine unit containing a branched saturated diamine having 6 to 22 carbon atoms.

The lactam used in the present invention includes ε-caprolactam, ω-enantholactam, ω-undecalactam, ω-dodecalactam, 2-pyrrolidone and the like. Examples of aminocarboxylic acids include 6-aminocaproic acid, 7-aminoheptanoic acid, 8-aminooctanoic acid,
0-aminocapric acid, 11-aminoundecanoic acid, 1
2-aminododecanoic acid and the like. These lactams and amino acids may be used alone or in combination of two or more. When lacram and aminocarboxylic acid are used in combination, they can be used in a mixture at any ratio. A polyamide comprising a polyamide derived from a lactam and / or an aminocarboxylic acid and a polyamide having a branched saturated diamine having 6 to 22 carbon atoms as a constituent component has a stretchability even if the content of the latter is small. Be improved.

Specific examples of the dicarboxylic acid used in the present invention include aliphatic dicarboxylic acids such as adipic acid, suberic acid, azelaic acid, sebacic acid and dodecanoic acid, 1,3-cyclohexanedicarboxylic acid, and 1,4-cyclohexanedicarboxylic acid. Alicyclic dicarboxylic acids such as acids, isophthalic acid,
Examples thereof include aromatic dicarboxylic acids such as terephthalic acid and naphthalenedicarboxylic acid. These dicarboxylic acids may be used alone or in combination of two or more.

Examples of the branched saturated diamine having 6 to 22 carbon atoms used in the present invention include 2,2,4-trimethyl-1,6-hexanediamine and 2,4,4-trimethyl-1,6-diamine. Hexanediamine, 1,2-diaminopropane, 1,3-diaminopentane, 2-methyl-1,5
-Diaminopentane and 2-methyl-1,8-diaminooctane. These may be used alone or in combination of two or more.

Examples of the diamine other than the branched saturated diamine having 6 to 22 carbon atoms include aliphatic diamines such as ethylenediamine, tetramethylenediamine, hexamethylenediamine, nonamethylenediamine, undecamethylenediamine and dodecamethylenediamine, and bis (4 -Aminocyclohexyl) methane, bis (4-aminocyclohexyl)
Propane, 1,3-bisaminomethylcyclohexane,
Alicyclic diamines such as 1,4-bisaminomethylcyclohexane; aromatic diamines such as meta-xylylenediamine and para-xylylenediamine; these diamines may be used alone, or The above may be used in combination as appropriate. Dicarboxylic acid and C6-
The diamine containing 22 branched saturated diamines is used in an approximately equimolar ratio.

The amount of lactam and / or aminocaproic acid used is 50 to 99.8 mol%, preferably 70 to 9 mol%.
9.5 mol%, dicarboxylic acid is 0.1 to 25 m
ol%, preferably 0.25 to 15 mol%, diamine 0.1 to 25 mol%, preferably 0.25 to 15 m
ol%. In addition, 10-100 mo of this diamine
1%, preferably 30 to 100 mol%, more preferably 50 to 100 mol%, is a branched saturated diamine having 6 to 22 carbon atoms. If the amount of the lactam and / or aminocarboxylic acid is less than the above lower limit, the mechanical strength may decrease. In addition, if it exceeds the above upper limit, the stretchability may decrease. 6 to 2 carbon atoms in the diamine
If the amount of the branched saturated diamine (2) is less than the above lower limit, the stretchability will decrease. On the other hand, when it exceeds the upper limit, stretchability is good, but practical physical properties such as mechanical strength are reduced.

The production of the polyamide according to the invention can be carried out batchwise,
Known polyamides such as batch type reaction vessels, kneading reaction extruders such as single tank type or multilayer type continuous reaction devices, tubular continuous reaction devices, single-screw kneading extruders, and twin-screw kneading extruders can also be carried out. Manufacturing equipment can be used. Known polymerization methods such as melt polymerization, solution polymerization and solid phase polymerization can be used as the polymerization method. These polymerization methods can be used alone or in an appropriate combination.

For example, a lactam and / or an aminocarboxylic acid, a dicarboxylic acid, a diamine containing a branched saturated diamine having 6 to 22 carbon atoms, and water are charged into a pressure-resistant container, and heated in a temperature range of 200 to 350 ° C. in a sealed state. After the polycondensation under pressure, the pressure is reduced to 200 to
By continuing the polycondensation reaction in the temperature range of 350 ° C. to increase the molecular weight, the desired polyamide can be produced. At this time, the diamine and the dicarboxylic acid may be charged as they are in a pressure-resistant container, or an approximately equimolar diamine and dicarboxylic acid are mixed and dissolved in water or alcohol, and then a nylon salt is formed. A concentrated solution state or a solid nylon salt obtained by recrystallization may be charged. The water used in the present invention is desirably ion-exchanged water or distilled water from which oxygen has been removed,
The amount used is generally 1 to 150 parts by weight based on 100 parts by weight of the raw material constituting the polyamide.

The high molecular weight polyamide is usually withdrawn from the reaction vessel in a molten state, cooled with water or the like, and then pelletized. In the case of pellets mainly composed of polyamide containing a large amount of unreacted monomers such as nylon 6, after removing unreacted monomers by hot water washing, they are used for production of films, monofilaments, fibers and the like. The polyamide of the present invention has a molecular weight of JI
The relative viscosity (η) measured by the method described in SK6810
r) in the range of 1.5 to 5.0, preferably 2.0 to 4.0.
5 In addition, there is no special restriction on the kind of the terminal group of the polyamide, its concentration or the molecular weight distribution.

In the polymerization of the polyamide of the present invention, if necessary, for promoting polymerization and preventing oxidation, phosphorus-based compounds such as phosphoric acid, phosphorous acid, hypophosphorous acid, polyphosphoric acid, metaphosphoric acid and alkali metal salts thereof are used. Compounds can be added. The addition amount of these phosphorus compounds is usually 50 to 3,000 ppm based on the polyamide to be obtained. In addition, amines such as laurylamine, stearylamine, hexamethylenediamine, meta-xylylenediamine, acetic acid, benzoic acid, stearic acid, hexanedioic acid, isophthalic acid, terephthalic acid, etc. for controlling the molecular weight and stabilizing the melt viscosity during molding. A carboxylic acid such as an 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 is 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, or the like. it can. Further, monofilaments and fibers can be produced by a known melt spinning method. The melting temperature of polyamide in a method using a melt extruder or a melt spinning method is from the melting point of the polyamide used to 320 ° C.

In the case of producing a film by the sequential biaxial stretching method, if necessary, a lubricant such as calcium stearate, a bisamide compound, silica, talc, a slip agent, a nucleating agent and the like are added to the polyamide of the present invention. The polyamide is melt-extruded by an extruder equipped with a die to form an unstretched film. The unstretched film may be continuously stretched in a continuous process, or may be wound up and then stretched. The stretching is performed at a temperature equal to or higher than the glass transition temperature (hereinafter, referred to as Tg) of the polyamide used. The first-stage stretching (primary stretching) in the sequential biaxial stretching is performed in a temperature range of Tg to (Tg + 50) ° C. in the film extrusion direction by a stretching ratio of 2
The film is stretched 2 to 5 times, preferably 2.5 to 4 times, and then the second-stage stretching (secondary stretching) performed in a direction perpendicular to the film extrusion direction is slightly higher in temperature than the primary stretching. At a temperature, the film is stretched at a stretching ratio of 2 to 5 times, preferably 2.5 to 4 times. Then, it is heat-set at a temperature of 150 ° C. or more, and a successively biaxially stretched film is obtained.

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 preferable as a material for a stretched film, and particularly suitable as a material for a sequential biaxially stretched film. It is used not only for films but also for monofilaments and fibers.
The stretchability of the fiber is also good. 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.

Hereinafter, the present invention will be described specifically with reference to Examples and Comparative Examples. The measurement 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 stretching tank of a mold (manufactured by Iwamoto Seisakusho), preheated at ambient temperature for 20 seconds, and then 3.2 times at a deformation rate of 35 mm / sec in the extrusion direction of the film. (Primary stretching), and heat-set at 200 ° C. to prepare a test film for measuring the total molecular plane orientation. 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 by using an automatic birefringence meter KOB.
It was measured with RA-21ADH type (manufactured by Oji Scientific Instruments), and the total molecular plane orientation degree (P) was determined by equation (1).

P = {(Nx + Ny) / 2} −Nz Equation (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 direction of the film) Nz indicates the refractive index in the thickness direction.) The smaller the value of P, the lower the orientation of the polyamide molecules and the better the stretchability.

3) Measurement of stretch ratio at break in secondary stretching by sequential biaxial stretching method Biaxial stretching machine BIX-7 adjusted to an ambient temperature of 60 ° C.
A sample film was attached to a stretching tank of type 03 (made by Iwamoto Seisakusho), preheated at ambient temperature for 20 seconds, and then stretched in the extrusion direction of the film to 3.0 times at a deformation speed of 35 mm / sec (primary stretching). Subsequently, the second stage stretching (secondary stretching) was performed in a direction perpendicular to the extrusion direction at a deformation speed of 35 mm / sec until the film was broken, and the stretching ratio at break was measured.

Example 1 Stirrer, thermometer, pressure gauge, pressure controller and polymer
Ε-Caprolact in a 5-liter pressure-resistant container equipped with an outlet
2,200 g of tom, 2,2,4-trimethyl-1,6-di
Aminohexane and 2,4,4-trimethyl-1,6-di
Mixture with aminohexane (Hüls, trade name:
Stamin TMD) 41.2 g, adipic acid 38 g and
Charged with 120 g of distilled water and repeated nitrogen pressurization and release several times
Then, the inside of the pressure vessel is replaced with nitrogen, and then the temperature is raised to 240 ° C.
Was. After reacting at 240 ° C. with stirring for 4 hours, 270
0kg / c over 2 hours after temperature rise
m ^Two・ Release the pressure to G and continue to supply nitrogen gas at 150 ml / min.
The reaction was carried out at 270 ° C. with stirring for 6 hours.
Next, the stirring is stopped, and the molten polymer is discharged from the polymer outlet.
Pull out the lamide in the form of a string, cool it with water, and pelletize it.
Thus, about 1800 g of pellets were obtained. 9 pellets
After washing for several hours under flowing hot water of 0 to 95 ° C, 80 ° C
And vacuum dried for 24 hours. Ηr of the obtained polyamide
Was 3.13. To 1500 g of this polyamide
Mix 0.45g of calcium phosphate and coat hanger
And supplied to an extruder equipped with a T-shaped die. Melts at 260 ° C
Melt and knead and extrude on cooling roll controlled at about 35 ° C
Then, an unstretched film having a thickness of 120 μm was produced. this
Unstretched film should not absorb moisture until stretchability is evaluated
And stored at 0 ° C. or lower. Unstretched fill
A sample of 92 mm length and 92 mm width cut out from the
Attach it to stretching machine BOX-703 type (Iwamoto Seisakusho)
After preheating at an ambient temperature of 60 ° C for 20 seconds, deformation at the same temperature
Stretched 3 times in the extrusion direction of the film at a speed of 35 mm / sec
(Primary stretching). Total molecular plane arrangement of the obtained stretched film
The orientation was measured. Table 1 shows the results. Also, the ambient temperature
60 ° C, deformation speed 35 mm / sec, 3.0 times in the extrusion direction
The film obtained by primary stretching is perpendicular to the extrusion direction at the same temperature.
Breaks in the direction at the same deformation speed of 35 mm / sec as primary stretching
The film was secondarily stretched to The draw ratio at the time of secondary stretching break is 4 times
there were.

Example 2 A mixture of 2,200 g of ε-caprolactam, 2,2,4-trimethyl-1,6-diaminohexane and 2,4,4-trimethyl-1,6-diaminohexane (trade name, manufactured by Huls Co., Ltd.) : Vestamine (TMD) 13.0 g, adipic acid 12.1 g and distilled water 100 g were charged in a pressure vessel in the same manner as in Example 1 to obtain a polyamide. Ηr of this polyamide was 3.47. The degree of orientation in all molecular planes of a film produced from this polyamide in the same manner as in Example 1 was measured. Table 1 shows the results. Further, the stretching ratio at the time of breaking of the secondary stretching by the sequential biaxial stretching measured in the same manner as in Example 1 was 3.5 times.

Example 3 A mixture of 2200 g of ε-caprolactam, 2,2,4-trimethyl-1,6-diaminohexane and 2,4,4-trimethyl-1,6-diaminohexane (trade name, manufactured by Huls Co., Ltd.) : Vestamine TMD) 19.7 g, hexamethylene diamine 3.6 g, isophthalic acid 25.9 g and distilled water 110 g were charged in the same manner as in Example 1 except that a polyamide was obtained. Ηr of this polyamide was 3.51. The degree of orientation in all molecular planes of a film produced from this polyamide in the same manner as in Example 1 was measured. Table 1 shows the results. The stretching ratio at the time of breaking of the secondary stretching by sequential biaxial stretching measured in the same manner as in Example 1 was 3.0 times.

Example 4 2200 g of ε-caprolactam, 2-methyl-1,5-
Example 1 except that 30.1 g of diaminopentane, 37.9 g of adipic acid and 118 g of distilled water were charged in a pressure-resistant container.
A polyamide was obtained in the same manner as described above. Ηr of this polyamide was 3.55. The degree of orientation in all molecular planes of a film produced from this polyamide in the same manner as in Example 1 was measured. Table 1 shows the results. The stretching ratio at the time of breaking of the secondary stretching by sequential biaxial stretching measured in the same manner as in Example 1 was 3.3 times.

Example 5 2200 g of ε-caprolactam, 2-methyl-1,8-
Example 1 except that 35.4 g of diaminooctane, 32.6 g of adipic acid and 118 g of distilled water were charged in a pressure vessel.
A polyamide was obtained in the same manner as described above. Ηr of this polyamide was 3.55. The degree of orientation in all molecular planes of a film produced from this polyamide in the same manner as in Example 1 was measured. Table 1 shows the results. The stretching ratio at the time of breaking of the secondary stretching by sequential biaxial stretching measured in the same manner as in Example 1 was 3.0 times.

Comparative Example 1 A polyamide (nylon 6) was obtained in the same manner as in Example 1 except that 2200 g of ε-caprolactam and 116 g of distilled water were charged into a pressure vessel. Ηr of this polyamide was 3.57. The degree of orientation in all molecular planes of a film produced from this polyamide in the same manner as in Example 1 was measured. Table 1 shows the results. The stretching ratio at the time of breaking of the secondary stretching by sequential biaxial stretching measured in the same manner as in Example 1 was 1.3 times.

Comparative Example 2 2200 g of ε-caprolactam, 30.1 g of hexamethylene diamine, 38.9 g of adipic acid and 11 parts of distilled water
A polyamide (copolymer of nylon 6 and 66) was obtained in the same manner as in Example 1 except that 9 g of the copolymer was charged in a pressure vessel. Ηr of this polyamide was 3.50. The degree of orientation in all molecular planes of a film produced from this polyamide in the same manner as in Example 1 was measured. Table 1 shows the results. The stretching ratio at the time of breaking of the secondary stretching by sequential biaxial stretching measured in the same manner as in Example 1 was 2.5 times.

[0037]

[Table 1]

Example 6 A polyamide obtained in the same manner as in Example 1 was extruded using a CS-40-26N type melt extruder manufactured by Uniplus at a cylinder temperature of 280 ° C. 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 at a deformation speed of 3 mm / sec. This operation was repeated five times.
It could be stretched up to 5 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. by using a CS-40-26N type melt extruder manufactured by Uniplus. Obtained. The monofilament was attached to a manual stretching machine and stretched by the same operation as in Example 6. This operation was repeated five times. As a result, the film was broken at a stretch ratio of 3.3 to 4.6.

Example 7 2000 g of 6-aminocaproic acid, a mixture of 2,2,4-trimethyl-1,6-diaminohexane and 2,4,4-trimethyl-1,6-diaminohexane (manufactured by Huls Co., Ltd.) (Name: Vestamine TMD) 54.8 g, adipic acid 50.5 g and distilled water 200 g were charged into the same pressure-resistant container as in Example 1, and nitrogen pressurization and depressurization were repeated several times. The temperature was raised to ° C. The reaction was conducted at 270 ° C. for 6 hours with stirring while flowing nitrogen gas at 150 ml / min. Next, the stirring was stopped, and the polyamide in a molten state was pulled out from the polymer outlet in a string form, cooled with water, and then pelletized to obtain 1600 g of pellets. The pellets were washed for several hours under flowing hot water at 90 to 95 ° C, and then vacuum dried at 80 ° C for 24 hours. Ηr of the obtained polyamide was 3.63. A film was formed from this polymer in the same manner as in Example 1, and the stretching ratio at the time of secondary stretching by sequential biaxial stretching was 3.8 times.

[0041]

The polyamide containing units comprising lactams and / or aminocarboxylic acids, units comprising dicarboxylic acids and units comprising diamines comprising branched saturated diamines having 6 to 22 carbon atoms, especially 10 to 100 of diamines
A polyamide whose mol% is a branched saturated diamine having 6 to 22 carbon atoms has excellent stretchability, and is particularly suitable as a material for a polyamide film for sequential biaxial stretching.

Continued on the front page (51) Int.Cl. ⁷ Identification code FI Theme coat II (reference) B29L 7:00 F term (reference) 4F210 AA29 AE01 AG01 QA02 QA03 QC06 QG01 QG18 4J001 DA01 DB04 DC11 DC14 EA02 EA04 EA06 EA07 EA08 EA13 EA15 EA16 EA17 EB08 EB09 EB14 EB36 EB37 EB46 EC05 EC07 EC08 EC09 EC13 EC14 EC16 EC47 EC48 FA03 FB03 FC03 FD01 JA01 JA10 JA12 JB13 4L035 BB31 BB79 BB89 BB91 DD14 HH10 JJ15

Claims (6)

[Claims] An extensibility comprising: a unit comprising a lactam and / or an aminocarboxylic acid; a unit comprising a dicarboxylic acid; and a unit comprising a diamine containing a branched saturated diamine having 6 to 22 carbon atoms. Excellent polyamide. 2. The stretchable polyamide according to claim 1, wherein 10 to 100 mol% of the diamine is a branched saturated diamine having 6 to 22 carbon atoms. 3. Lactam and / or aminocarboxylic acid 5
0 to 99.8 mol%, dicarboxylic acid 0.1 to 25 mo
1% by weight of a polyamide containing 0.1 to 25 mol% of a diamine, wherein 10 to 100 mol% of the diamine is a branched saturated diamine having 6 to 22 carbon atoms, and has excellent stretchability. 4. A branched saturated diamine having 6 to 22 carbon atoms is 2,2,4-trimethyl-1,6-diaminohexane,
2,4,4-trimethyl-1,6-diaminohexane,
It is a diamine selected from 1,2-diaminopropane, 1,3-diaminopentane, 2-methyl-1,5-diaminopentane, 2-methyl-1,8-diaminooctane or a mixture thereof. Claims 1-3
The polyamide having excellent stretchability according to any one of the above. 5. A film, monofilament or fiber made from the polyamide according to claim 1. 6. A successively biaxially stretched film produced from the polyamide according to claim 1.