JPH0657021A - Film made of polyamide resin - Google Patents

Abstract

PURPOSE:To provide a film, made of a polyamide resin and excellent in melt thermal stability in producing the film, transparency and slipperiness with hardly any defective appearance. CONSTITUTION:The film made of a polyamide resin is composed of a resin composition prepared by blending 100 pts.wt. polyamide resin having the number of terminal carboxyl groups [A] (mu equiv./g polymer) and the number of terminal amino groups [B] (mu equiv./g polymer) satisfying conditions of [B]>([A]+5) with 0.01-0.5 pt.wt. inorganic filler particles.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polyamide resin film, and more specifically, to a polyamide resin film having excellent melt heat stability during film production, less appearance defects, and excellent transparency and slipperiness. It's about film.

[0002]

2. Description of the Related Art Films made of polyamide resin are widely used mainly for food packaging because they are excellent in gas barrier properties and mechanical / thermal properties. The polyamide resin film is used as a single-layer film, a laminated film with another resin film, and a laminated film with another material.

If the film made of polyamide resin has poor slipperiness, the film is caught during bag making, and printing deviation occurs during multicolor printing. Therefore,
The slipperiness of a polyamide resin film is an important characteristic not only in terms of film productivity but also in terms of quality and commercial value.

Conventionally, various methods have been proposed to improve the slipperiness of a polyamide resin film. For example, Japanese Patent Publication No. 54-4741 proposes a method of blending inorganic filler particles, and Japanese Patent Publication No. 53-45226.
The publication discloses a method of blending polyethylene.

[0005]

However, in the method of blending the inorganic filler particles, when the surface activity of the inorganic filler particles is high, the melt heat stability of the polyamide resin is deteriorated, and a granular defect generally called fisheye or A streak-like appearance defect called a die line is likely to occur, which makes it difficult to stably and continuously produce a film having a good appearance. In particular, when silica particles are blended, although relatively good results can be obtained with respect to the transparency and slipperiness of the obtained film, die lines and fisheyes are very likely to occur.

Further, in the method of blending polyethylene,
Similar to the above, the transparency of the film is impaired, and further, the strength of the film is lowered. The present invention is
The present invention has been made in view of the above circumstances, and an object thereof is to provide a film made of a polyamide resin, which is excellent in melt heat stability at the time of film production, has few appearance defects, and is excellent in transparency and slipperiness.

[0007]

That is, the gist of the present invention is that the number of terminal carboxyl groups [A] (μeq / polymer 1 g) and the number of terminal amino groups [B] (μeq / polymer 1).
g) and a polyamide resin comprising a resin composition in which 0.01 to 0.5 parts by weight of inorganic filler particles are mixed with 100 parts by weight of a polyamide resin satisfying the condition of [B]> ([A] +5). It exists in the film made.

The present invention will be described in detail below. The present invention was completed based on the finding that, in a film using a polyamide resin having a specific terminal group ratio as a raw material resin, even if inorganic filler particles are blended, die lines and fish eyes are extremely small. Is.

In the present invention, the number of terminal carboxyl groups (content) [A] (μeq / g of polymer) and the number of terminal amino groups (content) [B] (μeq) are used as raw material resins.
/ Polymer 1 g) and [B]> ([A] +5),
Preferably, a polyamide resin satisfying the condition of [B]> ([A] +10) is used. The number of carboxyl groups in the above polyamide resin is preferably 50 (μeq / polymer 1 g) or less, more preferably 20 (μeq / polymer 1 g) or less.

If the number of terminal carboxyl groups is out of the above range, the thermal stability in melting is deteriorated and stable production of the film becomes difficult. The number of terminal carboxyl groups, the polyamide resin dissolved in benzyl alcohol,
It can be measured by titrating with 0.1N caustic soda,
The number of terminal amino groups can be measured by dissolving a polyamide resin in phenol and titrating with 0.05N hydrochloric acid.

The polyamide resin of the present invention can be produced by adjusting the polyamide raw material so that the number of terminal amino groups in the molecule is larger than the number of terminal carboxyl groups. When a lactam or ω-amino acid having a three-membered ring or more is used as a raw material, polycondensation is performed in the coexistence of a diamine, and when a dibasic acid and a diamine are used as raw materials, polycondensation is performed with an excess amount of diamine. To do. When lactams or ω-amino acids are used as raw materials, the amount of diamine used is 0.6 to 20 me as the number of amino groups with respect to these polyamide raw materials.
q / mol, preferably 0.8 to 18 meq / mol. When a dibasic acid is used as a raw material, the excess amount of the diamine with respect to the dibasic acid is adjusted to be the above amount.

Specific examples of lactams include ε-caprolactam, enanthlactam, capryllactam,
Examples include lauryl lactam, α-pyrrolidone, α-piperidone and the like. As the ω-amino acids, specifically,
6-aminocaproic acid, 7-aminoheptanoic acid, 9-aminononanoic acid, 11-aminoundecanoic acid and the like can be mentioned.

Specific examples of the dibasic acid include malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid,
Suberic acid, azelaic acid, sebacic acid, undecanedioic acid, dodecanedioic acid, tridecadioic acid, tetradecadioic acid, hexadecadioic acid, hexadecenedioic acid, octadecadioic acid, octadecenedioic acid, eicosandioic acid, enco Examples thereof include aliphatic dicarboxylic acids such as sendionic acid, docosandionic acid, and 2,2,4-trimethyladipic acid, and aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, phthalic acid, and xylylenedicarboxylic acid.

Specific examples of the diamine include ethylenediamine, trimethylenediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, heptamethylenediamine, octamethylenediamine, nonamethylenediamine, undecamethylenediamine, dodecamethylenediamine. , 2, 2, 4 (or 2,
4,4) -trimethylhexamethylenediamine, cyclohexanediamine, bis- (4,4'-aminocyclohexyl) methane, metaxylylenediamine and the like can be mentioned.

In the present invention, nylon 6 or nylon 6/66 is particularly preferably used from the viewpoint of the thermal and mechanical properties of the obtained film. Furthermore, in order to adjust the number of terminal carboxyl groups and terminal amino groups, it is particularly preferable to use hexamethylenediamine as the diamine to be present together or in excess during the polymerization.

The polyamide resin can be produced according to a conventional method by polymerizing the above polyamide raw material under reduced pressure for 0.5 hours or more, usually 1 to 2 hours. The relative viscosity (η _rel ) of the polyamide resin is JIS K 6810.
According to the above, the value measured in 98% sulfuric acid at a concentration of 1% and a temperature of 25 ° C. is 2 to 6, preferably 2 to 5. If the relative viscosity is too small, the mechanical properties of the obtained film are insufficient, and if the relative viscosity is too large, film formation tends to be difficult.

In the present invention, the inorganic filler particles to be blended with the polyamide resin are not particularly limited and can be arbitrarily selected from conventionally known inorganic filler particles and used. Specifically, clay-kaolin, silica-alumina clay minerals (hydrous aluminum silicates) represented by calcined kaolin, silica-magnesiums represented by talc, calcium silicate, silica, alumina, carbonic acid. Examples include calcium. Among these, talc, kaolin, calcined kaolin, and silica are preferable from the viewpoint of easy dispersibility. In particular, when silica is used, the obtained film has excellent transparency and good slipperiness.

The above-mentioned silica may be either so-called wet silica or dry silica, and has a specific surface area by the BET method of 50 m ² / g or more, preferably 100 m ^2.
/ G or more, and silica having an oil absorption of 50 ml / g or more measured according to JIS K 5101 is particularly preferable.

The inorganic filler particles have an average particle size of 0.4 to
The particle size is adjusted so that it does not include particles having a particle size of 10 μm or more in the range of 6.0 μm. If the average particle size is larger than the above range, fish eyes are likely to occur,
If it is less than the above range, the dispersibility will be poor, and moreover, the particles will be secondarily aggregated and fish eyes will be easily generated.

When inorganic filler particles treated with a silane or titanium surface treatment agent are used, the dispersibility is further improved and the transparency of the obtained film is further improved. The surface treatment method is not particularly limited, and for example, the method described in JP-A-63-251460 can be adopted.

The above-mentioned inorganic filler particles may be used alone or in combination with 2.
These are used in combination of two or more kinds, and the blending amount is selected from the range of 0.01 to 0.5 parts by weight, preferably 0.05 to 0.25% by weight, based on 100 parts by weight of the polyamide resin. When the content of the inorganic filler particles is less than the above range, a film having improved slipperiness cannot be obtained, and when it is more than the above range, a film having excellent transparency cannot be obtained.

In the present invention, in order to further improve the slipperiness of the film, it is preferable to blend a bisamide compound in the polyamide resin. The bisamide compound is a compound represented by the following chemical formula [Chemical formula 1], in which R ¹
Represents a divalent hydrocarbon residue, R ² and R ³ represent a monovalent hydrocarbon residue, and R ⁴ and R ⁵ represent a hydrogen atom or a monovalent hydrocarbon residue.

[0023]

[Chemical 1]

The bisamide compound represented by the above (I) is obtained by reacting a diamine with a fatty acid, and typical examples thereof include alkylene bis fatty acid amide and arylene bis fatty acid amide. As the raw material diamine,
Alkylenediamines such as ethylenediamine, propylenediamine, butylenediamine, hexamethylenediamine, octamethylenediamine, dodecamethylenediamine,
Examples thereof include arylene diamines such as phenylenediamine and naphthalenediamine, and arylene alkyldiamines such as xylylenediamine. Examples of the raw material fatty acids include stearic acid, hexanoic acid, octanoic acid, decanoic acid, lauric acid, myristic acid, palmitic acid, arachidic acid, behenic acid, oleic acid, elaidic acid, and montanic acid. As the bisamide compound represented by the above (I), N, N'-methylenebisstearic acid amide and N, N'-ethylenebisstearic acid amide are particularly preferable.

The bisamide compound represented by the above (II) is obtained by the reaction of a monoamine and a dicarboxylic acid, and is typically a dioctadecyl dibasic acid amide such as N, N'-dioctadecyl terephthalic acid amide. Can be mentioned. Examples of the raw material monoamine include ethylamine, methylamine, butylamine, hexylamine, decylamine, pentadecylamine, octadecylamine, dodecylamine and other alkylamines, aniline, naphthylamine and other arylamines, benzylamine and other aralkylamines, cyclohexylamine and the like. The cycloalkylamines of Examples of the raw material dicarboxylic acid include dicarboxylic acids such as terephthalic acid, p-phenylenedipropionic acid, succinic acid, and adipic acid.

The above bisamide compounds may be used alone or in combination of two or more. And the compounding quantity in polyamide resin is polyamide resin 10
0.01 to 1 part by weight, preferably 0 part by weight,
It is selected from the range of 0.05 to 0.5 parts by weight. When the compounding amount of the bisamide compound is less than the above range, the effect of improving the slipperiness is insufficient, and when it is more than the above range, the printability of the film and the adhesiveness during laminating are deteriorated.

The inorganic filler particles and the bisamide compound may be compounded by any of a dry blending method with polyamide resin pellets, a melt mixing method, or a master batch method in which a high concentration composition is compounded. Further, the inorganic filler particles and the bisamide compound may be blended with the polyamide raw material before or during the polymerization. Further, in the present invention, various known additives in the polyamide resin, for example, hindered phenol, antioxidants such as phosphoric acid esters and phosphorous acid esters, weather resistance improvers such as triazine compounds, pigments, Colorants such as dyes,
An antistatic agent, a lubricant, a plasticizer and the like can be added.

The film of the present invention can be manufactured, for example, by the T-die method,
It is manufactured according to a known film forming method such as an inflation method. Further, it may be an unstretched film or a uniaxially or biaxially stretched film. Further, it may be a single layer film or a laminated film formed by coextrusion or lamination. The thickness of the film can be appropriately selected according to the application.

[0029]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to the following examples as long as the gist thereof is not exceeded. Reference Example [Production of Polyamide Resin (N1 to N6)] 60 kg of ε-caprolactam, 1.2 kg of water and the amount of diamine or diamine and carboxylic acid shown in Table 1 or 2 were charged into a 200 liter autoclave.

The autoclave was sealed in a nitrogen atmosphere, heated to 260 ° C., reacted under pressure for 2 hours while stirring, and then gradually depressurized to a pressure shown in Table 1 or 2. Furthermore, the reaction was performed under reduced pressure for 2 hours.
Then, nitrogen was introduced into the autoclave to return to normal pressure, stirring was stopped, and the polyamide resin was extracted as a strand to form chips. Next, the polyamide resin chips were put into boiling water to extract and remove unreacted monomers, and then vacuum dried. The number of terminal carboxyl groups, the number of terminal amino groups, the relative viscosity and the water extraction amount of the polyamide resin were measured, and the results are shown in Table 1 or 2.

[0031]

[Table 1] ──────────────────────────────── N1 N2 N3 ──────────── ───────────────────── <Production conditions> Diamine type HMDA HMDA HMDA amount (meq / mol) 9.04 6.10 3.39 Carboxylic acid type ── ── ── amount ( meq / mol) ── ── ── Final pressure of polymerization reaction (Torr) 500 500 200 Number of terminal carboxyl groups (μeq / polymer 1g) 20 26 8 Number of terminal amino groups (μeq / polymer 1g) 100 80 50 Relative viscosity 2.50 2.71 4.10 Water Extraction amount (%) 0.45 0.40 0.40 ──────────────────────────────── (Note) HMDA: Hexamethylenediamine

[0032]

[Table 2] ──────────────────────────────── N4 N5 N6 ─────────── ───────────────────── <Production conditions> Diamine type HMDA ── ─ Amount (meq / mol) 90.59 ── ─ Carboxylic acid type Adipic acid Acetic acid amount ( meq / mol) 82.68 4.76 Final pressure of polymerization reaction (Torr) 200 500 500 Number of terminal carboxyl groups (μeq / polymer 1 g) 5 84 42 Number of terminal amino groups (μeq / polymer 1 g) 78 42 40 Relative viscosity 3.09 2.49 3.12 Water extraction (%) ) 0.40 0.45 0.55 ──────────────────────────────── (Note) HMDA: Hexamethylenediamine

Examples 1 to 8 and Comparative Examples 1 to 4 Each polyamide resin N1 to N6 obtained in the above reference example was dry blended with the following additives at the ratio shown in Table 3 or 4, and then the extruder was used. Using a T-die type film forming machine with a diameter of 40 mm, a resin temperature of 250 ° C., a cooling outlet temperature of 40 ° C.
A film of 5 μm was formed. (1) Bisamide compound Ethylene bis stearamide (hereinafter abbreviated as "EBS")

(2) Inorganic filler particles Talc ("Mistron Vapor" manufactured by Sipes Mines Co., specific surface area: 35 m ² / g, oil absorption: 50 ml / 1
00g, hereinafter abbreviated as "T")) Silica (1) ("Syloid 6" manufactured by Fuji Devison Co., Ltd.)
5 ", specific surface area: 700 m ² / g, oil absorption: 95 ml /
100 g, abbreviated as "S1") Silica (2) ("Syroid 24 manufactured by Fuji Devison Co., Ltd."
4 ", specific surface area: 300 m ² / g, oil absorption: 310 ml
/ 100g, abbreviated as "S2")

After the start of film formation, 1 hour, 2 hours, 4
Using the film after the lapse of time, the presence or absence of die lines and the number of fish eyes were visually observed. Further, the haze value and the coefficient of static friction were measured using the film for 1 hour after the start of film formation. The above results are shown in Table 3 or 4.

For the polyamide resin obtained by dry blending the above-mentioned additives in the ratio shown in Table 3 or 4, a Labo Plastomill (manufactured by Toyo Seiki Co., Ltd.) was used to evaluate the melting heat stability. Temperature 250 ℃, rotation speed 50r
Continuous stirring was carried out under the condition of pm, and the power after 10 minutes from the start of stirring and the power after 2 hours were measured to measure the fluctuation ratio of the power. The results are shown in Table 3 or 4.

The physical properties of the film were measured according to the following methods. (1) Haze The haze value was measured using a haze meter (manufactured by Tokyo Denshoku Co., Ltd.). (2) Sliding property The static friction coefficient (μs) was measured by a parallel movement method under the conditions of relative humidity of 65% and temperature of 23 ° C.

(3) Die line and fish eye The film was cut into a square of 300 × 300 mm, and the presence or absence of the die line was observed by visual observation of the portion, and the number of fish eyes having a size of 40 μm or more was measured.

[0039]

[Table 3]Example 1 2 3 4 5 6 Polyamide resin N1 N1 N2 N3 N3 N3 EBS compounding amount 0.1 0.1 0.1 0.1 0.1 0.1 <Inorganic filler> Type S1 S2 S1 S1 T S S1 Compounding amount 0.1 0.1 0.1 0.1 0.1 0.3 Haze (%) 2.1 2.0 2.1 2.4 3.6 2.8 Coefficient of static friction 0.45 0.40 0.45 0.50 0.50 0.45 <With die line> 1 hour No No No No No No No 2 hours No No No No No No 4 hours No No No No No No <fisheye > 1 hour 2 2 3 2 2 3 2 hours 8 6 2 3 4 5 4 hours 10 9 8 3 5 6 <Stirring power (Kw)> 5 minutes later 0.50 0.50 0.55 0.80 0.80 0.80 After 2 hours 0.75 0.80 0.85 1.00 1.00 1.15 Rate of change (%) 150 160 155 125 125 144 ──────────────────────────────────── (blend amount Represents parts by weight based on 100 parts by weight of the polyamide resin)

[0040]

[Table 4]Example Comparative example 7 8 1 2 3 4 Polyamide resin N3 N4 N3 N5 N6 N5 EBS blending amount-0.1 --- 0.1 <Inorganic filler> Type S1 S1-S1 S1 S1 Compounding amount 0.3 0.3 − 0.1 0.1 0.1 Haze (%) 2.4 1.6 0.5 2.3 2.5 2.4 Static friction coefficient 0.45 0.60 ＞ 1.5 0.65 0.60 0.55 <With die line> 1 hour No No No Yes Yes No Yes 2 hours No No Yes Yes Yes Yes Yes 4 Yes Yes Yes Yes Yes Yes Yes Eye ＞ 1 hour 2 2 13 10 15 25 2 hours 4 4 45 90 75 78 4 hours 6 3 88 ＞ 100 ＞ 100 ＞ 100 ＜ Stirring power (Kw) ＞ 5 minutes later 0.90 0.70 0.80 0.60 0.70 0.50 2 hours later 1.30 0.85 1.95 1.25 1.55 1.20 Rate of change (%) 144 121 244 208 221 240 ─────────────────────────────────── ─ (The blending amount represents parts by weight based on 100 parts by weight of the polyamide resin)

As is clear from the results shown in Tables 3 and 4, the polyamide resin film of the present invention is excellent in transparency and slipperiness. Further, the polyamide resin film of the present invention is excellent in thermal stability at the time of melting, as apparent from the small change rate of the stirring power of Laboplast mill, therefore, decomposition and crosslinking of the molten resin at the time of film formation. Since the resin is unlikely to deteriorate due to, it is unlikely to cause appearance defects such as the occurrence of die lines and an increase in fisheyes.

[0042]

According to the present invention described above, there is provided a film made of polyamide resin which is excellent in melt heat stability at the time of film production, has less appearance defects, and is excellent in transparency and slipperiness.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Tomoaki Kinmasa 370 Enzo, Chigasaki City, Kanagawa Mitsubishi Kasei Co., Ltd. Chigasaki Plant

Claims (4)

[Claims] 1. The number of terminal carboxyl groups [A] (μeq
/ Polymer 1g) and the number of terminal amino groups [B] (μeq /
Polymer 1 g) is 0.01 to 100 parts by weight of polyamide resin satisfying the condition of [B]> ([A] +5).
A polyamide resin film comprising a resin composition containing 0.5 parts by weight of inorganic filler particles. 2. The polyamide resin film according to claim 1, wherein the inorganic filler particles are silica particles. 3. The polyamide resin film according to claim 1, wherein the polyamide resin is nylon 6 terminal-modified with hexamethylenediamine. 4. The polyamide resin film according to claim 1 or 2, wherein the polyamide resin is nylon 6/66 terminal-modified with hexamethylenediamine.