JPS5946274B2 - Manufacturing method of polyamide film - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a polyamide film having excellent blocking resistance and transparency.

Polyamide films formed from polyamide compositions in which talc and a nonionic surfactant having an HLB value in the range of 10 to 15 are blended with polyamide are known.

(Japanese Unexamined Patent Publication No. 51-34256). This polyamide film has good blocking resistance, but
As for the transparency, as can be seen from the results of comparative examples described later, it is insufficient. An object of the present invention is to provide a method for producing a polyamide film that has excellent blocking resistance and transparency.

The object of the present invention is to combine polyamide and polyamide with 0.01 to 0.5% by weight of talc and the following formula CHOHCI] (wherein R is 12 to 24 carbon atoms, preferably 16 carbon atoms).
~24 acyl groups.

) monofatty acid ester of glycerin (hereinafter referred to as “
This is achieved by forming a polyamide consisting of monoglyceride (abbreviated as "monoglyceride") into a membrane. In this invention, all known polyamides can be used as the polyamide, such as ε-caprolactam, aminocaproic acid, natlactam, 7-aminoheptanoic acid, 11-aminoundecanoic acid, 9-aminononanoic acid,
Polymers such as α-pyrrolidone and α-piperidone, diamines such as hexamethylene diamine, nonamethylene diamine, undecamethylene diamine, dodecamethylene diamine, metaxylylene diamine, and terephthalic acid, isophthalic acid, adipic acid, sebacic acid, etc. Polymers obtained by polycondensation with dicarboxylic acids and copolymers thereof can be mentioned.

In this invention, talc has an average particle size of 0.5
~5μ, and it is preferable to use one that does not substantially contain particles with a particle size larger than 10μ. The blending amount of talc is 0.01 to 0.5% by weight based on the polyamide. If the blending amount of talc is smaller than the above lower limit, the blocking resistance of the obtained polyamide film will be poor, and if the blending amount of talc is larger than the above upper limit, the transparency of the obtained polyamide film will decrease, and furthermore, the polyamide film will contain many gels. Become recognized. Specific examples of monoglycerides used in this invention include lauric acid monoglyceride, myristic acid monoglyceride, palmitic acid monoglyceride, stearic acid monoglyceride,
Arachic acid monoglyceride, behenic acid monoglyceride,
Examples include lignoceric acid monoglyceride.

Among these monoglycerides, R in formula [1]
A monoglyceride having 16 to 24 carbon atoms is preferably used from the viewpoint of thermal stability. The monoglyceride used in this invention has an HLB value in the range of 3.3 to 6.0 (calculated by the method described in Chemical Handbook, Applied Edition, edited by the Chemical Society of Japan, page 603), and has a special Kaisho 51-34256
This is completely different from the nonionic surfactant having an HLB value within the range of 10 to 15 described in the above publication.
The blending amount of monoglyceride is 0.01 to polyamide.
It is 0.5% by weight.

If the blending amount of monoglyceride is smaller than the above-mentioned lower limit, the transparency of the obtained polyamide film will be reduced, and if the blending amount of monoglyceride is larger than the above-mentioned upper limit, the blocking resistance of the obtained polyamide film will be reduced. There are no particular restrictions on the method of blending talc and monoglyceride into the polyamide, and any known blending method can be employed.

For example, a method of dry blending talc, monoglyceride and polyamide, a method of kneading the above three in an extruder, etc. can be adopted. A particularly preferred blending method is to further blend a monoglyceride into a talc-containing polyamide obtained by polymerizing monomers in the presence of talc. According to this blending method, talc is uniformly dispersed in the polyamide, so that almost no gel is observed in the resulting polyamide film. however,
No matter which of the above compounding methods is adopted, there is no difference in the blocking resistance and transparency of the polyamide film obtained.
In this invention, a lubricant, an antistatic agent, an antioxidant, a blend oil, etc. can be added to the polyamide composition.

In the present invention, either the T-die method or the inflation method can be used to form the polyamide composition into a film.

A polyamide film can be obtained by extruding a polyamide composition into a film and then cooling it. However, by rapidly cooling the polyamide composition immediately after extruding it into a film, a polyamide film with better blocking resistance and transparency can be obtained. A film is obtained. As a rapid cooling method, the film-like material should be cooled to 5 to 35°C.
A method of cooling with water is conveniently adopted. The polyamide film thus obtained can be stretched as necessary.

As the stretching method, any known stretching method can be employed. Next, Examples and Comparative Examples will be shown.

In the Examples and Comparative Examples, the physical properties of the obtained polyamide films were measured as follows. (1) Static friction coefficient Using a slip tester manufactured by Nippon Rigaku Co., Ltd., ASTM
Measured according to Dl894-63.

(2) Blocking-resistant polyamide film at 40°C.
After leaving the film in a rolled state for 48 hours in an atmosphere with a humidity of 80%, the mutual blocking state of the film was judged with the naked eye according to the following criteria.

O: There is almost no blocking.

Δ: Some parts are slightly adhered.

×: Adhesive over the entire surface.

(3) Using a haze meter manufactured by Hayes Nippon Precision Engineering Co., Ltd., AST
Measured according to MDlOO3-61.

A film with a haze of 5% or less is completely transparent when observed with the naked eye. On the other hand, in a film having a haze of 6 to 10%, cloudiness is observed with the naked eye. (4) Gel number A film of 20C1fLX20CTfL was observed with the naked eye, and the number of gels that could be clearly detected was defined as the gel number.

In the following description, all parts indicate parts by weight. Example
6-Nylon (talc content: 6-nylon) obtained by polymerizing ε-caprolactam in the presence of talc with an average particle size of 1.5 μ and no particles larger than 10 μ
0.07 parts per 100 parts of nylon) and behenic acid monoglyceride with an HLB value of 3.6 [manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd., registered trademark: Resistut AF'101] 0.08
A composition was prepared by dry blending the following parts.

Immediately after extruding this composition into a film using an inflation method at an extrusion temperature of 260°C, it was cooled with water at 23°C to form a film with a thickness of 50°C.
A 6-nylon film of μ was obtained.

The physical properties of this film are shown in Table 1. Comparative Examples 1 to 3 In place of behenic acid monoglyceride, zorbitan fatty acid ester with an HLB value of 6.7 [manufactured by NOF Corporation, Nonion PP-40R] (Comparative Example 1), polyoxy with an HLB value of 13.3 Ethylene alkylphenol ether [manufactured by NOF Corporation, Nonion NS-210] (Comparative Example 2) or polyoxyethylene stearate with an HLB value of 11.6 [manufactured by NOF Corporation, Nonion S-4] ( Comparative example 3)
A thickness of 5 was prepared in the same manner as in Example 1 except that 0.08 part of
A 0μ 6-nylon film was obtained.

The physical properties of this film are shown in Table 1.

Example 2 A composition prepared in the same manner as in Example 1 was T-die molded at an extrusion temperature of 260°C, and immediately after extrusion into a film,
The film was cooled on a roll at 00° C. to obtain a film with a thickness of 50 μm.

The physical properties of this film are shown in Table 2.

Comparative Examples 4 to 6 In Comparative Examples 4 to 6, compositions prepared in the same manner as in Comparative Examples 1 to 3 were extruded at an extrusion temperature of 260°C.
Immediately after extruding it into a film using the T-die method, it was cooled on a roll at 100°C to obtain a film with a thickness of 50 μm.

Table 2 shows the physical properties of the obtained film.

Example 3 To 100 parts of poly-ε-caprolactam, 0.08 part of behenic acid monoglyceride used in Example 1 and 0 part of talc were added.
．． A composition was prepared by dry blending 0.07 parts.

Immediately after extruding this composition into a film using an inflation method at an extrusion temperature of 260°C, it was cooled with water at 23°C to form a film with a thickness of 50°C.
A film of μ was obtained.

The physical properties of this film are shown in Table 3.

Comparative Examples 7 to 9 In Comparative Examples 7 to 9, the thickness was changed in the same manner as in Example 3, except that 0.08 part of the nonionic surfactant used in Comparative Examples 1 to 3 was used instead of behenic acid monoglyceride. A 50μ film was obtained.

Table 3 shows the physical properties of these films. Example 4 The film obtained in Example 1 was Both directions were stretched 1 and 8 times.

The stretched film obtained in both the machine and transverse directions had a static friction coefficient of 1.12, a blocking resistance rating of "O", a haze of 2.0%, and a gel count of 2.

Example 5 Stearic acid monoglyceride with an HLB value of 4.1 [manufactured by Daiichi Kogyo Seiyaku Co., Ltd.] was used instead of behenic acid monoglyceride.
A 50 μm thick nylon film was obtained in the same manner as in Example 1, except that 0.08 part of Registered Trademark: Resist Pel32 was used.

This film had a silent friction coefficient of 0.48, a blocking resistance rating of "Good", a haze of 2.6%, and a gel count of 8.

Claims (1)

[Claims] 1 polyamide and 0.01 each for polyamide
~0.5% by weight of a polyamide consisting of talc and monofatty acid ester of glycerin represented by the following formula ▲ Numerical formula, chemical formula, table, etc. ▼ (wherein R is an acyl group having 12 to 24 carbon atoms) A method for producing a polyamide film, which comprises forming a composition into a film. 2. Claim 1, characterized in that a talc-containing polyamide is produced by polymerizing a monomer in the presence of talc, and a polyamide composition is prepared by blending a monofatty acid ester of glycerin with the obtained talc-containing polyamide. The manufacturing method of the polyamide film described in section. 3. The method for producing a polyamide film according to claim 2, which comprises rapidly cooling the polyamide composition immediately after extruding it into a film.