JPH0959510A - Polyamide resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a polyamide resin composition which gives oriented polyamide film with markedly improved anti-adhesion properties and slipperiness and is useful as a food product-packing film by adding fibrous xonotlite to a polyamide resin and orienting the formed polyamide resin. SOLUTION: (A) A polyamide resin such as nylon 6 is mixed with (B) 200-10,000ppm of fibrous xonotlite. The component B is, for example, shown by the formula: 6CaO.6SiO2 .H2 O and has following description: appearance: white particle; crystal form: needle; true specific gravity: 2.48; bulk specific gravity: <=0.2; fiber length: 1-5μm; fiber diameter: 0.1-0.5μm; specific surface area: 20-40m<2> /g. The component B is preferably admixed to the component A by uniformly dispersing it in the raw materials for the polyamide resin and then the polymerization is carried out.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a polyamide resin containing a fibrous xonotlite (calcium silicate) to prevent adhesion of a molded polyamide stretched film and to improve lubricity. The present invention provides a film, a film for packaging fibers, or a film for packaging industrial parts.

[0002]

2. Description of the Related Art In general, silica is mainly used as an antiblocking agent for polyamide films. However, a film containing silica has drawbacks such as 1) decrease in transparency, 2) loss of gloss, 3) film is easily scratched, and 4) poor color tone. Since no alternative antiblocking agent has been found, it is unavoidably used at present.

[0003]

According to the present invention, by using fibrous zonotolite as an anti-blocking agent for polyamide films, the above-mentioned drawbacks conventionally caused by using silica have been greatly improved. Is.

The details of the present invention will be described below.
The fibrous zonotolite of the present invention has a molecular formula of 6CaO · 6
It is represented by SiO ₂ .H ₂ O. A predetermined amount of this is mixed with a polyamide resin to form a film having a predetermined thickness by an extrusion molding method, and this film can be suitably used as a food packaging film, a fiber packaging film, an industrial parts packaging film, and the like.

The general physical properties of the fibrous xonotlite of the present invention are as follows: appearance: white granular crystal form: acicular true specific gravity: 2.48 bulk specific gravity: 0.2 or less fiber length: 1-5 μm fiber diameter: 0.1-0 0.5 μm specific surface area (BET method): 20 to 40 m ² / g. The present invention is not limited to those having the above general physical properties, but fibrous zonotolite having the above physical properties is preferable.

In the present invention, the amount of fibrous zonotolite added to the polyamide resin is 200 to 10,000.
ppm, preferably 1,000 to 3,000 ppm. If the addition amount is less than 200 ppm, the anti-blocking effect is not exhibited. Further, even if it exceeds 10,000 ppm, the effect does not extend and the physical properties of the polyamide film deteriorate.

Specific examples of the polyamide resin in the present invention include polylactams such as nylon 6, nylon 11 and nylon 12, polyamides such as nylon 66, nylon 610 and nylon 612, and polyamides obtained from dicarboxylic acid and diamine, nylon 6 / 66, nylon 6/6
Copolymerized polyamides such as 10, nylon 6/12, nylon 6/612, nylon 6/66/610, nylon 6/66/12, nylon 6 / 6T (T: terephthalic acid component), and mixtures thereof. To be

As a method of mixing with the polyamide resin, a method of uniformly dispersing in a raw material before polymerization and then polymerizing, or a method of mixing or kneading with a polyamide resin can be applied. Further, a resin composition containing a high concentration of fibrous zonotolite is prepared in advance by the above method,
A method of mixing the resin composition and a polyamide resin containing no fibrous xonotlite by dry blending can also be applied.

As a method for producing a film made of the resin composition of the present invention, a known production method can be applied. Specifically, the resin composition is melt-kneaded with an extruder,
A casting method in which a film is extruded into a flat film by a T-die or a coat hanger die and then cast on a casting roll surface to cool the film.
Alternatively, a tubular method or the like is used in which what is extruded into a tubular shape by a ring die is cooled with water.

The present invention can be achieved by continuously or in a separate step stretching a film produced in a flat shape or a tubular shape. For example, in the case of the sequential biaxial stretching method, a flat unstretched film is stretched 2 to 4 times by a roll type longitudinal stretching machine, and then stretched 3 to 5 times by a tenter type transverse stretching machine to obtain the obtained two films. The axially stretched film can be produced by heat-treating the film as desired, and then continuously winding the film while gradually cooling the film.

The biaxially stretched polyamide film according to the present invention is produced by the tenter sequential biaxial stretching method as exemplified above.
It can also be produced by other methods such as a tenter simultaneous biaxial stretching method and a tubular method.

Further, other additives such as an antioxidant, a weathering agent containing an ultraviolet absorber, an antistatic agent, a nucleating agent, a foaming agent, a coloring agent, a stabilizer, a coupling agent, etc., depending on required characteristics. Or other anti-blocking agent can be used in combination.

The film made of the resin composition containing the filler described above can be made into a laminate by using other polymer films. The method of forming this laminate is not particularly limited, and for example, a method of adhering a nylon film and another one or more polymer films with an adhesive,
Alternatively, a method of melt coextruding a nylon resin and a polymer compound constituting one or more other polymer films from a multi-layer die via an adhesive resin can be applied.

[0014]

EXAMPLES The present invention will be described in more detail below with reference to Examples and Comparative Examples. The methods of measuring or evaluating the physical properties are as follows. (1) Haze The direct reading haze meter manufactured by Suga Test Instruments Co., Ltd.
The haze (haze ratio) of the film was measured according to -1003. (2) Glossiness ASTM D
The glossiness of the film was measured according to -523. (3) Sliding property A dynamic slip tester manufactured by Rigaku Kogyo Co., Ltd.
The friction coefficient of the film was measured according to STM D-1894. (4) Evaluation criteria for blocking property of film ⊚: Can be easily peeled one by one. ◯: There was a part where force was applied to peel off. X: Adhered to form a plate.

Examples 1 to 3 and Comparative Examples 1 to 2 Commercially available nylon 6 resin (UBE manufactured by Ube Industries, Ltd.)
NYLON 1024B antiblocking agent-free product was used as a base resin (Comparative Example 1), and silica (Fuji Silysia KK-made Sylysia 310) 3000p was used as a conventionally used known antiblocking agent.
pm blended (Comparative Example 2), and the base resin (Comparative Example 1) dry-blended with a predetermined amount of master pellet containing 5% of fibrous zonotolite as an anti-blocking agent of the present invention (Example) 1 to Example 3) were used. Films were prepared from these 5 types of pellets under the following molding machine and molding conditions, and the physical properties were evaluated. Table 1 shows the evaluation results of physical properties. a) Molding machine: 40 mm φEx, T-die film molding machine manufactured by Plastic Engineering Laboratory b) Film thickness: 110 μm c) Molding conditions Temperature: Cylinder-adapter die C ₁ C ₂ C ₃ C ₄ AD D Set temperature 230 ° C 240 ° C 250 ℃ 250 ℃ 250 ℃ 250 ℃ Roll temperature 42 ℃ The above five types of pellets, the film formability is stable, no trouble was observed. Using a film having a thickness of 110 μm, a biaxially stretched film was formed under the following conditions. Forming machine: Biaxial stretching machine manufactured by Iwamoto Seisakusho Co., Ltd. Stretching ratio: Simultaneous stretching: 2.4 times length, 2.4 times width, 5.8 times in total Stretching temperature: 70 ° C. Film thickness: 20 μm 8 sheets stacked, 40g on the film
Table 1 shows the results of a blocking test conducted by placing a load of / cm ² and leaving it in a thermostat at 40 ° C. and 90% RH for 40 hours.

[0016]

[Table 1]

Continuation of front page (51) Int.Cl. ⁶ Identification number Office reference number FI technical display area B29L 7:00

Claims (1)

[Claims] 1. A polyamide resin containing fibrous zonotolite 2
A polyamide resin composition for a stretched film, which comprises 100 to 10,000 ppm.