Polyamide film

[Detailed Description of the Invention]

[0001]

[Industrial Application]

The present invention relates to the polyamide film which has the outstanding pinhole-proof nature and pliability.

[0002]

[Description of the Prior Art]

Since the polyamide film is excellent in the shock resistance, abrasion resistance, and pinhole-proof nature to which importance is attached in the packaging material field not to mention general instrument physical-properties, thermal characteristic, and barrier nature, it is widely used focusing on the food packing field. When frozen art had progressed in recent years, it was treated more often in the low-temperature atmosphere after food packing. about the pinhole-proof nature and pliability to which importance is most attached as a matter of fact in the above-mentioned characteristic, the temperature dependence is remarkable -- 10degreeC -- the restoration thing by a pinhole leaking and carrying out appearance in use in the following low-temperature atmosphere, -- etc. -- a trouble occurs and it is not necessarily satisfied practically. As a method of improving this, addition (JP,1-185363,A) of polycaprolactone, addition (JP,1-43624,B) of olefin system eye Onoma, etc. are proposed.

[0003]

On the other hand, it is as a constituent of polyamide and a polyether ester amide elastomer, 40~10 % of the weight (JP,63-278965,A) of nylon 6 / polyoxy tetramethylen glycols are known as 60~90 % of the weight of polyamide, and a polyether ester amide elastomer component, and the cast of low water absorption and a right size is provided.

[0004]

[Problem(s) to be Solved by the Invention]

However, the present condition is the pinhole-proof nature under low-temperature atmosphere not having been improved enough in the above-mentioned method, or having spoiled the transparency and intensity of a film of what has been improved. Then, the present invention makes a pinhole-proof improvement a subject, keeping the transparency and intensity of a film.

[0005]

[The means for solving an invention]

Namely, the present invention reaches as 99.5~91 % of the weight of (A) polyamide, and is the annular lactam of (B) (b) carbon number 6~12, and aminocarboxylic acid, (Ro) Polyoxy tetramethylen glycol of number average molecular weight 600~2500, (C) Fatty series dicarboxylic acid, The polyamide film consisting of the constituent which blends 0.5~9 % of the weight of polyether ester amide elastomers which are a copolymer with at least one sort of dicarboxylic acid selected from alicycle fellows dicarboxylic acid and aromatic dicarboxylic acid is provided.

[0006]

It is important to use the constituent in which predetermined [ comparatively little ] carries out comparatively the polyether ester amide elastomer which comprised a specific monomeric unit to polyamide resin in the present invention for a polyamide film, and, thereby, it produces the effect of the present invention.

[0007]

Below, the present invention is explained in detail.

[0008]

As the polyamide used as a (A) ingredient in the present invention, For example, the ring-opening-polymerization thing of annular lactam, the heavy condensation thing of aminocarboxylic acid, the heavy condensation thing of dicarboxylic acid and Gia Min, etc. are mentioned, Specifically, they are fatty series polyamide, such as nylon 6, Nylon 46, Nylon 66, Nylon 610, Nylon 11, and Nylon 12, Fatty series-aromatic polyamide, such as poly (hexamethylphthalamide), poly (hexamethylene isophthalamide), and poly (tetramethyleneisophthalamide), and these copolymers and mixtures can be mentioned. Nylon 6 and Nylon 66 can be mentioned as suitable polyamide especially for the present invention.

[0009]

The polyether ester elastomer used as a (B) ingredient in the present invention, It is the multi-block polymer which uses the ring-opening-polymerization thing of annular lactam, and the heavy condensation thing of aminocarboxylic acid as a hard segment, and uses polyoxy tetramethylen glycol as a soft segment, which polymerized uniformly and which is tough and has transparency. The polyether ester elastomer used for the present invention, Among alt. chlorophenol (0.5 weight / capacity %), from a point of the dispersibility from a point of intensity and pinhole-proof nature to 1.2 or more and the (A) ingredient, as for temperature C relative viscosity of 25 degrees, less than 5.0 are preferred, and it is especially preferred that it is [ or more 1.5 ] 1.5 or more and less than 4.5 and less than 4.0.

[0010]

As a (b) ingredient in this polyether ester amide, it is caprolactam, Although aminocarboxylic acid, amino dodecanoic acid, Lauro lactam, amino undecanoic acid, etc. are mentioned and there is no regulation in particular about the amount of copolymerization, in order to obtain a tough elastomer, It is desirable to use based on the full weight of a copolymer component at 10~80 % of the weight, preferably 15~75 % of the weight, more preferably 20~70% of the weight of a rate. The amount of copolymerization of the (b) ingredient is suitably chosen by the physical properties of the elastomer obtained, and the molecular weight of polyoxy tetramethylen glycol to be used, The molecular weight of what has a carboxyl group in the both ends constituted by the (b) ingredient which is a hard segment in the elastomer, and dicarboxylic acid component (C), It is preferred that they are less than 5000 ranges from a point of the ease of carrying out of 500 or more and a polymerization in points, like the cohesive force of a hard domain declines and the mechanical strength of an elastomer becomes low to a number average.

[0011]

Although the polyoxy tetramethylen glycol of the (Ro) ingredient in the polyether ester amide elastomer requires that a number average molecular weight should be in the range of 600~2500, There is no restriction in particular about the amount of copolymerization, and it is suitably chosen with the demand performance of the elastomer, for example, low-temperature physical properties, heat resistance, weatherability, etc. Since a polymerizing point will decrease if the melting point of the elastomer obtained although the number average molecular weight of this polyoxy tetramethylen glycol is based also on the amount of copolymerization by less than 600 becomes low, or the problem that those physical properties are not enough etc. arises and 2500 is exceeded on the other hand, control of a polymerization system becomes difficult.

[0012]

Dicarboxylic acid of the (C) ingredient in the polyether ester amide elastomer, Although not specified in particular, in order that an OH/COOH molar ratio may not bring about polymers quantification of an elastomer, and the fall of the mechanical properties by low-molecular quantity to the above-mentioned polytetramethylene glycol, 0.9 or more and less than 1.1 are preferred, It is preferred to become or more 0.9 less than 1.05, and or more 0.9 less than 1.0 range especially.

[0013]

What at least one sort selected from fatty series dicarboxylic acid, alicyclic dicarboxylic acid, and aromatic dicarboxylic acid is used as this dicarboxylic acid, and has that carbon number in the range of 4~20 is preferred. As such a thing, they are adipic acid, sebacic acid, and pimelic acid, for example, Aromatic dicarboxylic acid, such as alicyclic dicarboxylic acid, such as fatty series dicarboxylic acid, such as suberic acid, azelaic acid, and Dodecane dicarboxylic acid, cyclohexanedicarboxylic acid, and Decalin dicarboxylic acid, isophthalic acid, terephthalic acid, and naphthalene dicarboxylic acid, can be mentioned.

[0014]

It does not limit in particular for the manufacturing method of a polyether ester amide elastomer used as a (B) ingredient in the present invention, The usual publicly known method (JP,56-45419,B, JP,58-11459,B, JP,57-24808,B, JP,58-21095,A) can be used.

[0015]

About the combination rate of the polyamide of the (A) ingredient and the polyether ester amide elastomer of the (B) ingredient in the present invention, (A) It is required for 9% of the weight of the range, preferably a 0.5~(A) ingredient to be [ the (A) ingredient / for 93 % of the weight and a 99~(B) ingredient ] 1~7 % of the weight based on the sum total weight of an ingredient and the (B) ingredient in 91 % of the weight and a 99.5~(B) ingredient. (B) If the improvement effect of the pinhole-proof nature which an ingredient makes the object of the present invention in less than 0.5 % of the weight is not fully demonstrated and 9 % of the weight is exceeded, although it is demonstrated, since the improvement effect of pinhole-proof nature brings about the fall of film intensity and transparency, it is not preferred.

[0016]

As for the processing method of the constituent of the present invention, preparing by melt kneading is preferred, it carries out melt kneading as the method using a publicly known method, for example, the Banbury mixer, a mixing roll, a single axis, or a biaxial extrusion machine, and it obtains the pellet of a mixture. Subsequently, the pellet of this mixture is re-fused, a film is produced with the T-Di method, an inflation method, etc., and a non-oriented film is obtained. Or melt kneading of the (A) ingredient and the (B) ingredient can be carried out with an extrusion machine, a film can be produced by the above-mentioned method as it is, and a non-oriented film can be obtained. Then, this non-oriented film is extended in the at least 1 direction. Usually, vertical extension -> one by one, biaxial extension is preferred on productivity and the order of horizontal extension is used. Of course, un-extending and simultaneous biaxial extension are also possible, and ductility is very good. When heat-treating after extension holds dimensional stability and heat-resistant water, it is desirable, and strain heat treatment or relaxation heat treatment is effective.

[0017]

Thus, although the thickness in particular of the obtained film is not specified, they are 1~50 micrometers, preferably 1~45 micrometers, more preferably 5~40 micrometers.

[0018]

The pinhole-proof nature as used in the field of the present invention is inferior, so that it has thickness dependence and a film becomes thick. If film thickness exceeds 50 micrometers, even if it adds a polyether ester amide elastomer, the characteristic value made into the object of the present invention cannot be acquired.

[0019]

If the thickness of a film is smaller than 1 micrometer, use will not be borne as intensity maintenance material. Although the independent utility value of the film of the present invention is high, it is usable, even if other thermoplastics is laminated on this or it blends in addition further. For example, it becomes possible to make many characteristics which raise gas barrier nature, such as to tear and to raise intensity and to raise heat resistance, add, and utility value is raised further. As other resin, EvOH, a Porere fin, polyester, etc. are used preferably. Usually, EvOH is used by a blend or lamination and a Porere fin and polyester are used by lamination. The film characteristic added by the kind of thermoplastics to laminate changes. For example, if EvOH is laminated, an oxygen transmission rate can be made to fall remarkably, and heat resistance will be improved if polyester resin is laminated.

[0020]

On the film of the present invention, other ingredients, for example, heat stabilizer, a crystal-nucleus agent, an antioxidant, lubricant, a bulking agent, a plasticizer, etc. can be added in the range which does not spoil the physical properties.

[0021]

[Example]

Although an example is given to below and the present invention is further explained in full detail, the present invention is not limited to the following examples, unless the gist is exceeded. About each evaluation, it measured in accordance with the method described below.

[0022]

(1) Pinhole-proof [ low-temperature ] nature (repetition crookedness fatigue test) After adding the 1000 times repetition crookedness under 0 degreeC with what is called a Gerbo tester according to Method 2017 of Fed.Test Method Std.No.101C shown in MIL-B-131F, the number of the pinhole which arises on a film was made into the value.

[0023]

(2) Transparency (cloudy value) It measured by the JIS-K-6714 method.

[0024]

An evaluation result is shown in Table 1.

[0025]

Example 1 What copolymerized the polyoxy tetramethylen glycol of nylon 6 and number average molecular weight 650 45/55% of the weight as a polyether ester amide elastomer to nylon 6 (Toray Industries" friend run "CM1010) is added 9% of the weight, and it is 260degreeC, and is a biaxial extrusion machine, Then, fusion extrusion was carried out by T Di, and it cooled on the drum of 30 degreeC, and obtained a 180-micrometer non-oriented film. Then, it carried out by 3.4 times in the lengthwise direction, simultaneous biaxial extension of this film was carried out by 80 degree[ 3.5 times ] C at the transverse direction, and 15-micrometer pinhole-proof nature obtained the good film.

[0026]

Example 2 What copolymerized the polyoxy tetramethylen glycol of nylon 6 and number average molecular weight 800 30/70% of the weight as a polyether ester amide elastomer to nylon 6 (Toray Industries" friend run "CM1010) is added 5% of the weight, and the same method as Example 1 is followed, Pinhole-proof nature obtained the good film.

[0027]

Example 3 What copolymerized the polyoxy tetramethylen glycol of Nylon 12 and number average molecular weight 650 30/70% of the weight as a polyether ester amide elastomer to nylon 6 (Toray Industries" friend run "CM1010) is added 4% of the weight, and the same method as Example 1 is followed, Pinhole-proof nature obtained the good film.

[0028]

Comparative example 1 nylon 6 (Toray Industries" friend run "CM1010) -- with an independent film, it is less than the pinhole-proof nature of the present invention.

[0029]

Comparative examples 2 and 3 The amount of addition of the polyether ester amide elastomer to polyamide evaluated the thing of the composition used in the example about that from which it separates from the present invention. The improvement effect of pinhole-proof nature was not seen in comparative example 2, but pinhole-proof nature had the bad transparency of the film of the good thing in comparative example 3.

[0030]

[Table 1]

[0031]

[Effect of the Invention]

In the present invention, specific quantity addition of the polyether ester amide elastomer is carried out at polyamide. Therefore, it becomes possible to improve pinhole-proof nature under the degree of low temperature important for a polyamide film, holding the transparency of a film.

[0032]

The use range under the degree of low temperature of the polyamide film restricted until now will spread greatly by the present invention.