JP3212374B2 - Polyamide resin film - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a film made of a polyamide resin, and more particularly, to a film made of a polyamide resin which is excellent in melting heat stability at the time of film production, has less appearance defects, and is excellent in transparency and slipperiness. It is about film.

[0002]

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

In the case of a film made of a polyamide resin, if the slipperiness is poor, the film is caught during bag making, and printing misregistration occurs during multicolor printing. Therefore,
The slipperiness of a polyamide resin film is an important property not only from the viewpoint of the productivity of the film but also from the viewpoint of quality and commercial value.

Conventionally, various methods have been proposed for improving the slipperiness of a film made of a polyamide resin. For example, Japanese Patent Publication No. 54-4741 proposes a method of blending inorganic filler particles.
In Japanese Patent Laid-Open Publication No. HEI 9-204, a method of blending polyethylene is proposed.

[0005]

However, in the method of blending the inorganic filler particles, when the surface activity of the inorganic filler particles is high, the melting heat stability of the polyamide resin is degraded, and there is a problem of granular defects generally called fish eyes. A streak-like appearance defect called a die line is likely to occur, making it difficult to stably and continuously produce a film having a good appearance. In particular, when silica particles are blended, relatively good results are obtained in terms of transparency and slipperiness of the obtained film, but die lines and fish eyes are extremely likely to occur.

In addition, in the method of blending polyethylene,
As described above, there is a disadvantage that the transparency of the film is impaired and the strength of the film is reduced. The present invention
In view of the above circumstances, it is an object of the present invention to provide a film made of a polyamide resin which has excellent melting heat stability at the time of film production, has less 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 / g of polymer) and the number of terminal amino groups [B] (μeq / polymer 1 g)
g) is a resin composition comprising 0.01 to 0.5 parts by weight of inorganic filler particles per 100 parts by weight of a polyamide resin satisfying the condition of [B]> ([A] +5). In film.

Hereinafter, the present invention will be described in detail. The present invention has been 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. It is.

In the present invention, the number (content) of terminal carboxyl groups (A) (μeq / g of polymer) and the number (content) of terminal amino groups (B) (μeq)
/ 1 g of polymer) 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 / g of polymer) or less, more preferably 20 (μeq / g of polymer) or less.

When the number of terminal carboxyl groups is out of the above range, the stability of the melt heat is deteriorated, and it is difficult to produce a stable film. The number of terminal carboxyl groups was determined by dissolving the polyamide resin in benzyl alcohol,
It can be measured by titration with 0.1N caustic soda,
The number of terminal amino groups can be measured by dissolving the polyamide resin in phenol and titrating with 0.05 N hydrochloric acid.

The polyamide resin in 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 using lactams or ω-amino acids having three or more rings as a raw material, polycondensation is carried out in the presence of a diamine. Do. When using a lactam or an ω-amino acid as a raw material, the amount of the diamine is 0.6 to 20 me as the number of amino groups with respect to the polyamide raw material.
q / mol, preferably 0.8 to 18 meq / mol. When a dibasic acid is used as a raw material, the amount is adjusted so that the excess amount of the diamine with respect to the dibasic acid is the above amount.

Examples of the lactams include ε-caprolactam, enantholactam, capryllactam,
Lauryl lactam, α-pyrrolidone, α-piperidone and the like. As ω-amino acids, specifically,
6-aminocaproic acid, 7-aminoheptanoic acid, 9-aminononanoic acid, 11-aminoundecanoic acid and the like.

As the dibasic acid, specifically, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid,
Suberic acid, azelaic acid, sebacic acid, undecandioic acid, dodecandionic acid, tridecadionic acid, tetradecadionic acid, hexadecadionic acid, hexadecenedionic acid, octadecadionic acid, octadesendioic acid, eicosandioic acid, enco Examples thereof include aliphatic dicarboxylic acids such as sendioic acid, docosandioic 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 ethylene diamine, trimethylene diamine, tetramethylene diamine, pentamethylene diamine, hexamethylene diamine, heptamethylene diamine, octamethylene diamine, nonamethylene diamine, undecamethylene diamine, dodecamethylene diamine. , 2,2,4 (or 2,
4,4) -Trimethylhexamethylenediamine, cyclohexanediamine, bis- (4,4'-aminocyclohexyl) methane, meta-xylylenediamine 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 hexamethylene diamine as a diamine which is coexistent or excessively present during polymerization.

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

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

[0018] Examples of the silica may be either a so-called wet silica and dry silica, BET specific surface area is 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 preferred.

The inorganic filler particles have an average particle size of 0.4 to
The particle size is adjusted so as to be within a range of 6.0 μm and not containing particles having a particle size of 10 μm or more. If the average particle size is larger than the above range, fish eyes are likely to occur,
On the other hand, when it is smaller than the above range, the dispersibility is poor, and the particles are likely to secondary aggregate and generate fish eyes.

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

The above-mentioned inorganic filler particles may be used alone or
These are used in combination of at least one kind, and the compounding amount is selected from the range of 0.01 to 0.5 part by weight, preferably 0.05 to 0.25% by weight based on 100 parts by weight of the polyamide resin. If the amount of the inorganic filler particles is less than the above range, a film with improved slipperiness cannot be obtained. If the amount is more than the above range, a film with excellent transparency cannot be obtained.

In the present invention, it is preferable to blend a bisamide compound with the polyamide resin in order to further improve the slipperiness of the film. The bisamide compound is a compound represented by the following chemical formula [Formula 1], wherein 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]

Embedded image

The bisamide compound represented by the above (I) is obtained by reacting a diamine with a fatty acid, and typically includes an alkylene bisfatty acid amide and an arylene bisfatty acid amide. As the raw material diamine,
Ethylenediamine, propylenediamine, butylenediamine, hexamethylenediamine, octamethylenediamine, alkylenediamines such as dodecamethylenediamine,
Examples thereof include arylene diamines such as phenylenediamine and naphthalenediamine, and arylene alkyl diamines such as xylylenediamine. Examples of the fatty acid as a raw material include stearic acid, hexanoic acid, octanoic acid, decanoic acid, lauric acid, myristic acid, palmitic acid, arachidic acid, behenic acid, oleic acid, elaidic acid, montanic acid, and the like. As the bisamide compound represented by the above (I), N, N'-methylenebisstearic acid amide and N, N'-ethylenebisstearic acid amide are particularly preferred.

The bisamide compound represented by the above (II) is obtained by reacting a monoamine with a dicarboxylic acid, and is typically a dioctadecyl dibasic amide such as N, N'-dioctadecylterephthalamide. Can be mentioned. Examples of the raw material monoamine include alkylamines such as ethylamine, methylamine, butylamine, hexylamine, decylamine, pentadecylamine, octadecylamine and dodecylamine, arylamines such as aniline and naphthylamine, aralkylamines such as benzylamine and cyclohexylamine. Of cycloalkylamine. 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 amount in the polyamide resin is the 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. If the amount of the bisamide compound is less than the above range, the effect of improving the slipperiness is insufficient. If the amount is more than the above range, the printability of the film and the adhesion during laminating are reduced.

The method of blending the inorganic filler particles and the bisamide compound may be any of a method of dry blending with pellets of polyamide resin, a method of melt mixing, and a masterbatch method of blending a high-concentration composition. Further, the inorganic filler particles and the bisamide compound may be added to 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 phosphates and phosphites, weather resistance improvers such as triazine compounds, pigments, Coloring agents such as dyes,
An antistatic agent, a lubricant, a plasticizer and the like can be added.

The film of the present invention can be produced, for example, by the T-die method,
It is manufactured according to a known film forming method such as an inflation method. An unstretched film or a uniaxial or biaxially stretched film may be used. 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]

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to the following examples unless it exceeds the gist. Reference Example [Production of Polyamide Resins (N1 to N6)] In a 200-liter autoclave, 60 kg of ε-caprolactam, 1.2 kg of water, and diamine or diamine and carboxylic acid in the amounts shown in Table 1 or 2 were charged.

The autoclave was sealed in a nitrogen atmosphere, the temperature was raised to 260 ° C., the reaction was carried out under pressure for 2 hours with stirring, then the pressure was gradually released to reduce the pressure to the pressure shown in Table 1 or 2, Further, the reaction was performed under reduced pressure for 2 hours.
Thereafter, nitrogen was introduced into the autoclave, and the pressure was returned to normal pressure. After that, stirring was stopped, and the polyamide resin was taken out as a strand and extracted into chips. Next, the polyamide resin chip was put into boiling water to extract and remove unreacted monomers, and then dried under vacuum. The number of terminal carboxyl groups, the number of terminal amino groups, the relative viscosity and the amount of water extraction 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) ── ── ──Polymerization reaction final pressure (Torr) 500 500 200 Number of terminal carboxyl groups (μeq / polymer 1 g) 20 26 8 Number of terminal amino groups (μeq / polymer 1 g) 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} ───────────────────── <Manufacturing conditions> Diamine type HMDA ── Amount (meq / mol) 90.59 ── 酸 Carboxylic acid type Adipic acid Acetate 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 Amount of water extraction (% ) 0.40 0.45 0.55 ──────────────────────────────── (Note) HMDA: Hexamethylenediamine

Examples 1 to 8 and Comparative Examples 1 to 4 The following additives were dry-blended in the ratios shown in Tables 3 and 4 to the polyamide resins N1 to N6 obtained in the above Reference Examples, and then extruded. 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. and a thickness of 2
A 5 μm film was formed. (1) Bisamide compound Ethylene bis stearoamide (hereinafter abbreviated as "EBS")

(2) Inorganic filler particles Talc (“Mistron Vapor” manufactured by Sipes Mines, 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) (“Syloid 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 hours
Using the film after time, the presence or absence of a die line and the number of fish eyes were visually observed. Further, the haze value and the coefficient of static friction were measured by using the film one hour after the start of film formation. The above results are shown in Table 3 or 4.

In order to evaluate the heat stability of a polyamide resin obtained by dry blending the above additives at the ratios shown in Tables 3 and 4, a Labo Plastomill (manufactured by Toyo Seiki Co., Ltd.) was used. Temperature 250 ° C, rotation speed 50r
Continuous stirring was performed 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 power fluctuation ratio. The results are shown in Table 3 or 4.

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

(3) Die Line and Fish Eye The film was cut into a square of 300 × 300 mm, the presence or absence of a die line was observed by visual inspection 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 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 Static coefficient of friction 0.45 0.40 0.45 0.50 0.50 0.45 <Die line presence> 1 hour None None None None None None 2 hours None None None None None None Four hours None None None None None None <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 2 hours later 0.75 0.80 0.85 1.00 1.00 1.15 Rate of change (%) 150 160 155 125 125 144 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 compounding 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 coefficient of friction 0.45 0.60> 1.5 0.65 0.60 0.55 <Die line presence> 1 hour No No No Yes No Yes 2 hours No No Yes Yes Yes Yes 4 hours Yes Yes Yes Yes Yes Yes <Fish 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)> After 5 minutes 0.90 0.70 0.80 0.60 0.70 0.50 After 2 hours 1.30 0.85 1.95 1.25 1.55 1.20 Rate of change (%) 144 121 244 208 221 240 ─────────────────────────────────── ─ (Blending amount represents parts by weight based on 100 parts by weight of polyamide resin)

As apparent from the results 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 has excellent thermal stability at the time of melting, as is apparent from the low rate of change of the stirring power of the Labo Plastomill, and therefore, decomposition and crosslinking of the molten resin during film formation. The resin hardly causes deterioration of the resin, so that appearance defects such as generation of die lines and increase of fish eyes are unlikely to occur.

[0042]

According to the present invention described above, there is provided 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.

Continuation of the front page (51) Int.Cl. ⁷ Identification code FI C08L 77:06 C08L 77:06 (72) Inventor Tomoaki Kanasa 370 Yenzo, Chigasaki City, Kanagawa Prefecture Mitsubishi Kasei Corporation Chigasaki Office (56) Reference Document JP-A-62-252424 (JP, A) JP-A-62-148527 (JP, A) JP-A-62-10136 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C08J 5/18 C08K 3/00-3/40 C08L 77/00-77/12

Claims (4)

(57) [Claims] 1. The number of terminal carboxyl groups [A] (μeq
/ 1 g of polymer) and the number of terminal amino groups [B] (μeq /
1 g of the polymer is 0.01 to 100 parts by weight of the 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, wherein the polyamide resin is nylon 6/66 terminal-modified with hexamethylenediamine.