JPH06179813A - Polyamide resin film - Google Patents

Abstract

PURPOSE:To continuously and stably obtain a film having a good appearance from a resin composition excellent in transparency, slip property, and thermal stability during melting. CONSTITUTION:The title film is made from resin composition obtained by incorporating 0.01-0.5 pt.wt. particulate inorganic filler (e.g. silica) and 0.01-0.5 pt.wt. magnesium salt of a 12-30C hydroxylated fatty acid (e.g. hydroxystearic acid) into 100 pts.wt. polyamide resin (e.g. nylon 6 or 6/66).

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a novel polyamide resin film. More specifically, the present invention relates to a polyamide resin film which is excellent in melt heat stability during film production, has less appearance defects, and is excellent in transparency and slipperiness.

[0002]

2. Description of the Related Art Polyamide resin films are excellent in gas barrier properties and mechanical / thermal properties, so that they are mainly used for food packaging, such as single layers, multilayer films with other resins, laminated films with other materials, etc. Is used in a wide range of applications. If the film made of such a polyamide resin has poor slipperiness, the film may be caught during bag making, or ink misalignment may occur during multicolor printing. Therefore, the slipperiness of the film is an extremely important characteristic from the viewpoint of the productivity, quality and commercial value of the film.

Various methods have hitherto been attempted for improving the slipperiness of the polyamide resin film.
For example, a method of blending inorganic filler particles (Japanese Patent Publication No.
No. 4741) and a method of blending polyethylene (Japanese Patent Publication No. 53-45226).

[0004]

However, in the former method of blending the inorganic filler particles, the transparency of the obtained film is lowered and the commercial value is remarkably lowered, so that the blending amount is restricted. Further, the slipperiness of the film cannot be sufficiently improved only by blending the inorganic filler particles.

In addition, in the method of blending inorganic particles, when the surface activity of the inorganic particles is high, the thermal stability of the polyamide resin becomes poor, which leads to grain defects called fish eyes and die lines. A streak-like appearance defect is likely to occur, and it is difficult to stably continuously produce a film having an excellent appearance. In particular, when silica-based inorganic particles are blended, although relatively good results can be obtained with respect to the transparency and slipperiness of the obtained film, appearance defects such as die lines and fish eyes are extremely likely to occur, and appearance It is difficult to stably produce a good film for a long time.

On the other hand, in the method of blending polyethylene,
As a result, the transparency of the film is significantly lowered, and at the same time, the strength of the film is lowered. For this reason, it has been the actual situation that a polyamide resin film capable of continuously and stably forming a film for a long time without causing a defective appearance and having excellent transparency and slipperiness has not been industrially obtained.

[0007]

Means for Solving the Problems The present inventors have overcome the drawbacks of such conventional polyamide resin films, have excellent transparency and slipperiness, and produce poor appearance even when continuous film formation is performed. As a result of extensive studies to provide a difficult polyamide resin film, by forming a film using a resin composition containing inorganic filler particles and a magnesium salt of hydroxy fatty acid, it was found that the purpose can be achieved. The present invention has been reached.

That is, the gist of the present invention is that the inorganic filler particles are added in an amount of 0.01 to 100 parts by weight of the polyamide resin.
A polyamide resin film comprising a resin composition containing 0.5 parts by weight and 0.01 to 0.5 parts by weight of a magnesium salt of a hydroxy fatty acid having 12 to 30 carbon atoms.
Hereinafter, the present invention will be described in detail.

As the polyamide resin used in the present invention, a polyamide resin obtained by polycondensation of a lactam having 3 or more membered rings, a polymerizable ω-amino acid, a dibasic acid and a diamine can be used. In particular,
Polymers such as ε-caprolactam, aminocaproic acid, enanthlactam, 7-aminoheptanoic acid, 11-aminoundecanoic acid, 9-aminononanoic acid, α-pyrrolidone and α-piperidone, hexamethylenediamine, nonamethylenediamine, undecamethylene Polymers obtained by polycondensing diamines such as diamine, dodecamethylenediamine, and metaxylenediamine with dicarboxylic acids such as terephthalic acid, isophthalic acid, adipic acid, sebacic acid, dodecane dibasic acid, and glutaric acid, or copolymers thereof. It is a polymer, for example, nylon 4, 6, 7, 8, 1
1, 12, 6 ・ 6, 6 ・ 10, 6 ・ 11, 6 ・ 12, 6
T, 6/6 · 6, 6/12, 6 / 6T, 61 / 6T and the like.

Of these, the thermal properties of the resulting film
From the viewpoint of mechanical properties, especially nylon 6 resin, nylon 6
The use of a / 66 copolymer resin is preferred. Regarding relative viscosity (η _rel ) of polyamide resin, JIS-K-681
According to 0, a range of 2 to 6, preferably 2 to 5 is suitably used with the value specified at a concentration of 1% in 98% sulfuric acid and a temperature of 25 ° C. If the relative viscosity is too low, the mechanical properties of the resulting film will be insufficient, and if it is too high, film formation will be difficult.

Regarding the polyamide resin of the present invention, the amount of water extracted for measuring the content of low molecular weight substances according to JIS-K-6810 is 1% or less, preferably 0.5.
% Or less is preferable. When the amount of water extracted is large, low molecular weight substances such as monomers and dimers tend to adhere to the area around the die, and such low molecular weight substances may come into contact with or adhere to the film, resulting in poor visual appearance such as fish eyes. Is likely to occur.

The inorganic filler particles used in the present invention are not particularly limited, and any one can be selected and used from among those conventionally used as resin fillers. Specifically, clay, kaolin, silica represented by calcinable kaolin-alumina clay minerals (hydrous aluminum silicates), silica represented by talc-
Magnesium, as well as calcium silicate, silica,
Alumina, calcium carbonate and the like can be mentioned, and among these, talc, kaolin, calcinable kaolin and silica are particularly preferable from the viewpoint of easy dispersibility. Among them, the use of silica is particularly preferable because the resulting film has excellent transparency and good slipperiness.

These inorganic filler particles have a particle size of 10 μm.
The average particle size is 0.4 to 6.0 and does not include particles of m or more.
Those in the range of μm are preferable. If the particle size is large,
When the particle size is too small, dispersibility becomes poor and fish eyes are likely to occur due to secondary aggregation of the filler, which is not preferable. As the silica suitable for the present invention, both so-called wet silica and dry silica can be used, but the specific surface area by the BET method is 50 m ² / g or more, more preferably 100 m 2.
It is preferably ² / g or more and the oil absorption measured according to JIS-K-5101 is 50 ml / 100 g or more.

When these inorganic filler particles are surface-treated with a well-known surface treating agent such as a silane treating agent or a titanium type treating agent, good dispersibility can be obtained, and at the same time, a film obtained can be obtained. The transparency is also improved. The method of surface treatment is not particularly limited, but, for example, the method described in JP-A-63-251460 may be used.

The inorganic filler particles of the present invention are used singly or in combination of two or more kinds described above, and the compounding amount thereof is 0.0 with respect to 100 parts by weight of the polyamide resin.
It is selected in the range of 1 to 0.5 parts by weight, preferably 0.05 to 0.25 parts by weight. When the blending amount is small, the slipperiness of the obtained film is not improved, and when the blending amount is too large, the transparency decreases.

The magnesium metal salt of hydroxyfatty acid used in the present invention is a salt of hydroxycarboxylic acid having 12 to 30 carbon atoms and magnesium. For example, hydroxycarboxylic acid and magnesium oxide or hydroxide are reacted directly with heating. Can be obtained by At this time, if magnesium oxide or hydroxide is excessively added to synthesize highly basic hydroxy fatty acid magnesium, better results can be obtained. Specifically, it is a magnesium salt of a hydroxy compound of an aliphatic carboxylic acid such as lauric acid, myristic acid, palmitic acid, stearic acid and behenic acid. If the carbon number of the fatty acid is small, the desired effect cannot be obtained, and if the carbon number is too large, the transparency is deteriorated, which is not preferable. Therefore, the carbon number is 1
It is selected in the range of 2 to 30, preferably 12 to 24. Magnesium salt of hydroxy fatty acid is 0.01 to 0.5
Parts by weight, preferably 0.05 to 0.2 parts by weight are blended. If the blending amount is small, the effect of improving the appearance cannot be seen, and if the blending amount is large, the transparency decreases.

The inorganic filler and the magnesium metal salt of hydroxystearic acid may be blended by a so-called external addition method of dry blending with a pelletized raw material of a polyamide resin, a kneading method of melt mixing, or a high concentration of the inorganic filler. Either a so-called masterbatch method in which a raw material containing a magnesium salt of hydroxy fatty acid and / or an internal addition method in which it is added at the time of polymerization is used is possible.

In the present invention, it is effective to add a bisamide compound for the purpose of improving slipperiness. As the bisamide compound, the following general formula [I] or [II],

[0019]

[Chemical 1]

(Wherein R ¹ is a divalent hydrocarbon residue, R ²
And R ³ are monovalent hydrocarbon residues, and R ⁴ and R ⁵ are hydrogen atoms or monovalent hydrocarbon residues). Examples of the bisamide compound represented by the general formula [I] include alkylenediamines such as ethylenediamine, propylenediamine, butylenediamine, hexamethylenediamine, octamethylenediamine and dodecamethylenediamine, and arylenediamines such as phenylenediamine and naphthalenediamine. Diamines such as arylenealkyldiamines such as xylylenediamine and stearic acid, hexanoic acid, octanoic acid, decanoic acid, lauric acid, myristic acid, palmitic acid, arachidic acid, behenic acid, oleic acid, elaidic acid, montanic acid, etc. Examples include alkylene bis fatty acid amides and arylene bis fatty acid amides obtained by reaction with a fatty acid. Among these, as typical ones,
N, N'-methylenebisstearic acid amide and N,
Mention may be made of N'-ethylenebisstearic acid amide.

Examples of the bisamide compound represented by the general formula [II] include ethylamine, methylamine,
Butylamine, hexylamine, decylamine, pentadecylamine, octadecylamine, dodecylamine and other alkylamines, aniline, naphthylamine and other arylamines, benzylamine and other aralkylamines, cycloalkylamine and other monoamines and terephthalic acid, Those obtained by reaction with a dicarboxylic acid such as p-phenylenedipropionic acid, succinic acid, and adipic acid are selected. Typical of these are N, N'-dioctadecyl terephthalic acid amide and the like. Mention may be made of dioctadecyl dibasic acid amide.

These bisamide compounds may be used alone or in combination of two or more, and the compounding amount thereof is 0.01 with respect to 100 parts by weight of the polyamide resin.
˜1 part by weight, preferably 0.05 to 0.5 part by weight. If the blending amount is small, the effect of improving the slipperiness cannot be seen, and if the blending amount is too large, the printability of the film and the adhesiveness at the time of laminating are reduced, which is not preferable.

There is no particular limitation on the method of preparing the resin composition which is the base material of the film of the present invention, and it can be prepared according to the method usually used. For example, the polyamide resin pellets may be dry-blended with inorganic filler particles, preferably further with a bisamide compound at a predetermined ratio, or may be melt-mixed with an extruder. Further, the inorganic filler particles and the bisamide compound may be added before or during the polymerization, and so-called internal addition may be performed.

In addition to the above-mentioned compounds, the resin composition contains various additives well known to those skilled in the art, such as hindered phenols, antioxidants such as phosphoric acid esters and phosphorous acid esters, and triazine compounds. Weather resistance improver, pigment,
It may contain a coloring agent such as a dye, an antistatic agent, a lubricant and the like. The resin composition thus prepared can be molded into the polyamide film of the present invention by a known film forming method. As a film forming method,
A T-die method, an inflation method or the like is applied, and it is used as an unstretched film or as a stretched film after a stretching step such as uniaxial stretching or biaxial stretching. The polyamide film of the present invention may be a monolayer film or a laminated film formed by coextrusion or lamination.

[0025]

EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited thereto.

<Examples 1 to 8 and Comparative Examples 1 to 4> As polyamide resins, commercially available nylon 6 resin having a relative viscosity of 4.5 (manufactured by Mitsubishi Kasei Co., Ltd., Novamid 1030, Novamid is a registered trademark) and nylon. Using 6/66 copolymer resin (Novamid 2030 manufactured by Mitsubishi Kasei Co., Ltd.), the additives shown in Table-1 were compounded in the ratio shown in Table-2, and the extruder diameter was 4
Using a 0 mmφ T-die type film forming machine, resin temperature 270 ° C.,
A film having a thickness of 25 μm was formed at a cooling roll temperature of 40 ° C. In addition, using the film 1 hour, 2 hours, and 4 hours after the start of film formation, the presence or absence of streak-like appearance defects called die lines and the number of granular appearance defects called fish eyes were visually observed. I observed. Further, the haze value and static friction coefficient were measured using the film 1 hour after the start of film formation.
The results are shown in Table-3.

Further, a polyamide resin composition blended in the ratio shown in Table 2 was prepared by using Labo Plastomill (Toyo Seiki Co., Ltd.).
Manufactured) was continuously stirred at 250 ° C. and a rotation speed of 50 rpm, the power 10 minutes after the start of stirring and the power 2 hours after the stirring were measured, and the fluctuation ratio of the power was measured. The results are shown in Table-3.

The film was measured by the following method. (1) Haze The haze value was measured using a haze meter manufactured by Tokyo Denshoku Co., Ltd. (2) Sliding property The static friction coefficient (μ _S ) was measured by a parallel movement system under the conditions of relative humidity of 65% and temperature of 23 ° C. (3) Appearance of film Cut the film into a square of 300 mm x 300 mm,
The presence or absence of die lines and the number of fish eyes having a size of 40 μm or more were measured by visual observation of the portion.

[0029]

[Table 1]

[0030]

[Table 2]

[0031]

[Table 3]

[0032]

As shown in the examples, the polyamide resin film of the present invention has excellent transparency and slipperiness, and as shown by the small change rate of the stirring power of Laboplast mill, The film has good thermal stability at the time of film formation, and therefore, deterioration of the molten resin during film formation, such as decomposition and crosslinking, is unlikely to occur, so that appearance defects such as the occurrence of die lines and an increase in fisheyes are less likely to occur, and a film with a good appearance. It has an excellent property that can be continuously and stably obtained.

Claims (2)

[Claims] 1. 0.01 to 0.5 part by weight of inorganic filler particles and 12 carbon atoms per 100 parts by weight of polyamide resin.
~ 30 hydroxy fatty acid magnesium salt 0.01 ~
A polyamide resin film comprising a resin composition containing 0.5 part by weight. 2. The polyamide resin film according to claim 1, wherein the inorganic filler particles are silica.