KR0173420B1 - Polyamide Resin Composition for Film Production - Google Patents

Abstract

The present invention relates to a polyamide resin composition having improved gas barrier properties, transparency, anti-blocking properties, puncture strength, and the like, and is appropriately dispersed in the polyamide resin so that the interlayer distance before the cation exchange reaction between the layered silicate and the swelling agent is 0.8 to 1.5 nm. The polyamide resin composition is synthesized and contains 0.1 to 10% by weight of the fluorine compound-based water repellent and the triazine aliphatic induction system water repellent in a 1: 1 ratio.

Description

Polyamide Resin Composition for Film Production

The present invention is to uniformly disperse and mix a fluorine compound crab water repellent and a triazine aliphatic derivative-based water repellent in a polyamide polymer obtained by homogeneously dispersing an organic layered silicate having a multi-layered structure in a polyamide monomer and then polymerizing it. When manufacturing a film by the method, it is related with the novel resin composition which can manufacture the polyamide film by which piercing strength, transparency, gas barrier property, workability, etc. were improved significantly.

Polyamide films are used in the field of food packaging because of their excellent gas barrier properties, transparency, pinhole resistance, heat resistance and oil resistance compared to other resin films. However, due to the development of the consumer industry, in recent years, the food packaging industry requires more improved gas barrier properties and puncture resistance, but according to the use, the gas barrier property and the puncture resistance are not sufficient. In particular, the polyamide film has a characteristic of reducing gas barrier properties under high humidity. Therefore, a method of coextrusion molding with an ethylene vinyl alcohol copolymer having excellent gas barrier properties or coating polyvinylidene chloride having good gas barrier properties on the polyamide surface is preferred. It is done. However, ethylene vinyl alcohol and polyvinylidene chloride are expensive and there is a big problem in economics due to the increase in processing and equipment cost, such as coating equipment installation due to the multi-layer composition of the coextruded film.

In particular, in polyamide films, moisture is absorbed in a high humidity environment, thereby degrading the activity and rigidity of the film. Such deterioration of rigidity may be a fatal defect depending on the type of food, especially in food packaging. Foods with sharp parts such as crabs should be able to be packaged without rupture of the film, that is, to maintain a certain degree of puncture stiffness in order to expect food hygiene and safety. In addition, since the degradation of rigidity may cause trouble in post-processing processes, such as a lamination process, a printing process, and a bag manufacturing process, the situation is strongly demanded for improvement.

In order to improve the activity and transparency in addition to the above characteristics, a method of adding metallurgical gums, bisamides, polyolefins, inorganic fine particles, and the like is known. Among them, the addition of inert inorganic particles such as silica, talc and kaolin is known. It has been found to be effective and is commercialized However, when the rigidity of the polyamide film is lowered due to moisture absorption, the improvement is very difficult. Excessive addition of talc, for example, not only impairs transparency, but also leads to a decrease in gas barrier properties and rigidity. In addition, since polyamide film is easy to block, the surface properties can be improved by changing the surface structure of the film (JP-A-40-958), adding fatty acid amide (JP-A-33-9788), and micronized inorganic material. Although the method of changing (Japanese Unexamined-Japanese-Patent No. 49-4275) is known, the method of adding an undifferentiated inorganic substance is known as the most preferable method of improving blocking resistance. However, the addition of finely divided inorganic materials has a mutually opposite relationship between blocking resistance and transparency, and in particular, there is a drawback that white turbidity and transparency are worsened due to crystallization phenomenon due to undifferentiated inorganic materials during cooling during film manufacturing. .

The present inventors earnestly studied to improve such a conventional defect, and as a result, the organic layered silicate is uniformly dispersed in the polyamide, and the fluorine-based water repellent and the triazine aliphatic derivative-based water repellent are obtained by mixing alone or in an appropriate ratio. The present invention has been completed by knowing that when a resin composition is molded by a conventional film forming method, a film having remarkably improved piercing stiffness, transparency, gas barrier property, blocking resistance, and the like can be produced.

That is, the present invention is a composition in which a fluoro compound-based water repellent agent and a triazine aliphatic derivative-derived water repellent agent are mixed alone or in an appropriate ratio and mixed with polyamide uniformly dispersed in a multilayer structure layered silicate. The polyamide film excellent in transparency, activity, etc. can be manufactured.

Examples of the polyamide resin used in the present invention include nylon 6, nylon 6/6, nylon 11, nylon 12, nylon 6/10, nylon 6/11, nylon 6/12, polymethaxylene adiamide, Polyparaxylene adiamide, and the like, and these may be used alone, as copolymers or blends.

Organic layered silicate used in the present invention is a very important factor to improve the mechanical properties of the film. In order to improve the mechanical properties of the resin, the filling of glass fibers or other inorganic fine particles was common, but recently, nano-composites have been developed. Compared to the glass fiber having a diameter of about 13 μm, the nanocomposite is a composite in which the dispersed phase is dispersed in nanometers, and is a microdispersion system located between the micro and molecular dispersion systems. Among these complexes, the present invention is characterized by using nylon 6-clay hybrid (NCH) as a nylon layered silicate complex using a layered dosing method. NCH is a nanocomposite uniformly dispersed as a monolayer (thickness 0.5 to 3.0 nm, length 50 to 150 nm) in nylon 6 by expanding the multilayer structure of the layered silicate during polymerization of ε-caprolactam in the presence of layered clay. The layered silicate composite is required to be uniformly dispersed in the polyamide, and it is preferable to synthesize the layered silicate so that the interlayer distance before the cation exchange reaction between the layered silicate and the swelling agent is 0.5 to 1.5 nm. Interlayer distance here refers to the distance between the centers of the layered silicate plates.

As the raw material of such a layered silicate, in the present invention, clay minerals such as montmorillonite, saponite, biderite, notoronite, hectorite, halomite, baiculite, and the like can be used. Among these, montmorillonite is most preferable. .

In the present invention, the blending amount of the organic layered silicate is preferably 0.1 to 5% by weight based on the layered silicate composite based on the polyamide. At this time, it is important to control cation exchange rate of layered silicate and swelling agent when synthesizing polyamide polymer with layered organic layer.When converting to 95% or more of cation exchange rate, add 0.1 ~ 1 equivalent of layered silicate to powder method or solution. In both methods, the conversion is observed to be 95% or more.

Preferably, 0.4 to 0.6 equivalents of the layered silicate is added to the swelling agent. If 0.1 equivalent or less of the swelling agent is added, the conversion is very poor. If more than 1 equivalent is added, a considerable amount of the swelling agent is not reacted and is not preferable.

The swelling agent used in the present invention is an organic salt obtained from amino acids, such as 12-aminododecanoic acid or 6-aminocaproic acid, and water and 35% HCI.

Fluorine compound-based water repellents and triazine aliphatic induction system water repellents used in the present invention are used to improve the transparency, blocking resistance and tear strength of the film. After homogeneous blending on the chip and dried at 100 ~ 180 ℃ apply. At this time, the blending amount of the water repellent is good in 0.1 to 10% by weight based on the polyamide, the composite chip is used directly in the production of master batch or film.

In the present invention, the fluorine compound-based water-repellent agent preferably has a structural formula represented by the following formula (1), and specific commercial products thereof include Zeppel, USA, or Scotch Guard FC series of 3M.

In the present invention, the triazine aliphatic induction system water repellent is preferably represented by the following formula (2), and commercialized products thereof include Hobotex FT of CIBA.

(Wherein R, R 'and R are each an alkyl group having 2-20 carbon atoms)

Preferably, the compound treatment method of the fluorine compound-based water repellent and the triazine aliphatic induction system water repellent is most useful, and as the water evaporates depending on the total amount of fluorine compounds present in the matrix of the triazine aliphatic derivative by heating, the fluorine water repellent The particles are embedded in the metric of the triazine aliphatic derivative, causing deformation of the particles, resulting in a compound with the fluorine compound and triazine aliphatic derivative matrix in the continuous film. When thermal energy is supplied by curing, the association of the fluorine compound is dispersed and the hydrophobic group of the fluorine compound is oriented at the interface with air because of the property of taking the lowest energy interface.

In the master batch obtained in this way, the molecular mass of the triazine aliphatic derivative and the fluorine compound molecules which are not oriented are exposed, and the water / oil repellency tends to be temporarily lowered. The hydrophobic group of R 2 is redirected by sufficient thermal energy (220 to 260 ° C.), thereby preventing water from being in contact with the polyamide film in the cooling process, thereby solving the problem of clouding due to crystallization and a problem of lowering transparency.

In addition, the improved activity can significantly reduce the defects due to trouble prevention in the subsequent process.

At this time, the mixing ratio of the fluorine compound-based water repellent and the triazine aliphatic derivative-based water repellent is most preferably 1: 1.

As the constituent components of the polyimide film of the present invention, an antioxidant, a heat stabilizer, a weathering agent, an antistatic agent, an inorganic fine particle powder, and the like can be blended according to a conventional method, and a method of forming an unstretched film. For example, the polyamide polymer containing the organic layered silicate and the appropriate ratio of water repellent may be melt-kneaded from an extruder at an extrusion temperature of 200 to 300 ° C. to be extruded into a film form from a Ti-die, or by a tube die. Usually, all the tubular methods etc. which water-cooled the extruded thing are applicable.

As a method of manufacturing a stretched film, the unstretched film made by the said method can be manufactured by well-known methods, such as a tenter method and a tubular method, at extending | stretching temperature of 50-180 degreeC.

According to the present invention, a polyamide polymer having a homogeneous dispersion of an organic layered silicate is uniformly dispersed in a specific water repellent at room temperature, and then dried first at a constant temperature to prepare a composite polyamide resin composition. By manufacturing, it is possible to manufacture a polyamide film having improved puncture stiffness, transparency, blocking resistance, gas barrier properties, and the like of the conventional method.

The present invention will be described in detail with reference to the following Examples, which are not intended to limit the present invention. In Example, the transparency of the film was measured according to ASTM-D1003, and the oxygen permeability was measured according to ASTM D-3985-8 at 0% relative humidity. Tensile properties were measured according to ASTM D-882. The blocking resistance was visually confirmed after blocking for 72 hours at 20 ℃, 65% relative humidity.

Example 1

100 gr of montmorillonite were dispersed in 10 L of water, and 134.5 gr of 6-aminocaproic acid and 24 ml of 35% hydrochloric acid were added thereto, followed by stirring for 10 minutes, to obtain a fine powder using a spray dryer. At this time, it was confirmed by x-ray that the interlayer distance before cation exchange reaction between the layered silicate and the swelling agent was 1.2 nm.

100 g of the organic composite obtained above was added to 10 Kg of ε-caprolactam and 500 mL of water, and 0.02% of polyoxyethylene sorbitan monostearate and 0.03% of thyroid 310 (average particle diameter of 1.4 µm) were added and mixed under pressure at 260 ° C. The chips were boiled at 95 ° C. for 24 hours and then vacuum dried. Add water repellent mixed with CIBA's 0.5% by weight of Hobotex FT (0.5% by weight) and 3M's ScotchGuard FC-208 (by solid content) to the double-composite chip, and then uniformly disperse at room temperature and stir at 150 ° C in a dryer. Primary heat treatment was performed for a minute to prepare a polyamide resin composition containing an organic layered silicate and a mixed water repellent. The resin composition was extruded in an extruder having a diameter of 400 mm and then solidified by water cooling (10 ° C.), followed by stretching and heat treatment to prepare a final 15 μm film. Table 1 shows the results of measuring the film properties of the film thus obtained.

Example 2

The same process as in Example 1 was carried out except that the amount of the organic composite added in Example 1 was 200 gr.

Example 3

The same process as in Example 1 was carried out except that the amount of the organic composite added in Example 1 was 450 gr.

Example 4

Example 1 was the same as in Example 1 except that 0.1% by weight of Hobotex FT and 0.1% by weight of ScotchGuard FC-208.

Comparative Example 1

The same process as in Example 1 was carried out except that the amount of the organic composite added in Example 1 was 600 gr.

Comparative Example 2

Example 1 was the same as in Example 1 except that Hobotex FT and Scotchguard FC-208 were not added.

Comparative Example 3

Except for adding Hobotex FT and ScotchGuard FC-208 in Example 1, except that 0.5% by weight of DuPont Zeolane AP was added in the same manner as in Example 1.

[Comparative Example 4]

Except for adding Hobotex FT and ScotchGuard FC-208 in Example 1 0.05% by weight was carried out in the same manner as in Example 1.

Claims (6)

A film comprising 0.1 to 10% by weight of a mixture of a fluorine-based water repellent and a triazine aliphatic derivative-based water repellent in a reaction mixture of a polyamide resin with a layered silicate and a swelling agent at 0.1 to 5% by weight. Polyamide resin composition for production. The polyamide resin composition according to claim 1, wherein the polyamide resin is nylon 6, nylon 66, nylon 12 or a copolymer thereof. The polyamide resin composition for film production according to claim 1, wherein the layered silicate is appropriately dispersed and synthesized in polyamide such that the interlayer distance before the cation exchange reaction between the layered silicate and the swelling agent is 0.8 to 1.5 nm. The polyamide resin composition for film production according to claim 1, wherein the fluorine compound-based water repellent and the triazine aliphatic induction system water repellent are mixed in a 1: 1 ratio. The polyamide resin composition for film production according to any one of claims 1 to 4, wherein the fluorine compound-based water repellent is a compound represented by the following formula (1). The polyamide resin composition for producing a film according to any one of claims 1 to 4, wherein the triazine aliphatic induction system water repellent is a compound represented by the following formula (2). (Wherein R, R 'and R are each an alkyl group having 2 to 20 carbon atoms)