KR0145484B1 - Polymer film and its manufacturing method - Google Patents

Abstract

In the present invention, the first polymer vertical layer. In the polymer resin film containing the 2nd polymer resin layer formed in at least one surface of this. The first polymer resin layer comprises from 0.01 to 0.1% by weight of a sulfonic acid metal salt, from 0.005 to 0.5% by weight of a hindered phenol crab compound, and from 1 to 20% by weight of an inorganic lubricant, 95% by weight) and polyolefin resin (5-35% by weight), and the second polymer resin layer contains a high polymerization polyester having ethylene terephthalate and ethylene isophthalate as main repeating units. A polymer film characterized by is disclosed. The polymer resin film produced by the method of the present invention can be used in various fields such as packaging, industrial, etc. because of good antistatic properties and printing characteristics, and excellent heat sealing and lining processing properties.

Description

Polymer film and its manufacturing method

The present invention relates to a polymer film and a method for manufacturing the same, and more particularly, to a polymer film having a good antistatic property and printability, and excellent in heat sealing and lining processing properties, and a method of manufacturing the same.

Among the polyesters, polyethylene terephthalate is chemically and physically stable, has high mechanical strength, and is excellent in heat resistance, durability, chemical resistance, and electrical insulation, and thus is used for medical, industrial, magnetic recording media, capacitors, and photographic films. Of course, it is widely used for manufacturing various molded articles. The white pigment is coated on the surface of the polyester film or treated by chemical or mechanical methods to impart paper-like properties, and thus it is widely used in calenders, labels, and high-quality wrapping papers using a soft texture and white background. In addition, it is recently used for the appearance of home appliances such as refrigerators and electronic ovens to decorate or prevent corrosion, and is used for packaging containers such as metal cans to simplify the painting process and to prevent environmental pollution by eliminating the use of solvents. .

Japanese Laid-Open Patent Publications No. 62-243120 and Hei 2-206622 disclose a method of adding inorganic particles to polyester as a manufacturing method for imparting a paper-like texture to a polyester film. As another method, a foaming agent is added to the polyester to reduce the weight (Japanese Laid-Open Patent Publication No. 58-50625), and a polyolefin resin is blended and stretched to polyester to form micropores on the surface and inside of the film. There is a method (Japanese Laid-Open Patent Publication No. 57-49648) that simultaneously seeks surface and light weight. As another method, Japanese Laid-Open Patent Publication No. Hei 6-1711045 discloses a method of coating the surface of polyester to improve the chargeability.

However, the polyester film produced by the conventional method as described above has good antistatic properties and printability, but poor heat sealing properties and laminate properties. Therefore, if you want to use for packaging, there is a disadvantage that a separate surface treatment or adhesive should be used.

Disclosure of Invention It is an object of the present invention to provide a polymer film having excellent antistatic property and printability, excellent heat sealing and laminate properties, and a method of manufacturing the same by solving the above problems.

In this invention, in order to achieve the said objective, in the polymer resin film containing a 1st polymer resin layer and the 2nd polymer resin layer formed in at least one surface of this.

The first polymer resin layer comprises from 0.01 to 0.1% by weight of a sulfonic acid metal salt, from 0.005 to 0.5% by weight of a hindered phenolic compound, and from 1 to 20% by weight of an inorganic lubricant, based on the polyester resin (65 to 95% by weight) and polyolefin resin (5-35% by weight), and the second polymer resin layer contains copolyester having ethylene terephthalate and ethylene isophthalate as main repeating units. A polymer film is provided.

It is preferable that the said 2nd polymer resin layer contains the copolyester which has 1 to 30 weight% of ethylene isophthalate in a main repeating unit.

It is preferable that specific gravity of the said polymer film is 0.9-1.2, and the thickness of the said 1st polymer resin layer is 50 to 90% of the thickness of all the polymer films.

It is preferable that specific gravity of the said polymer film is 0.9-1.2, and the thickness of the said 1st polymer resin layer is 50 to 90% of the thickness of all the polymer films.

Preferably, the sulfonic acid metal derivative (acid value 1.0 mg KOH / g or less) is represented by the following formula (1).

R ₁ -SO ₃ Me (1)

Is a C ₅ -C ₂₀ alkyl group and Me is an alkaline earth metal or alkali metal selected from the group consisting of Li, Na, K, and Mg.

Another object of the present invention is to provide a polycondensed polyester resin formed from 0.01 to 1.0% by weight of a sulfonic acid metal salt, 1 to 20% by weight of an inorganic lubricant, and 0.005 to 0.5% by weight of a hindered phenolic compound (65). To 95 wt%) of the polyolefin resin (5 to 35 wt%) compounding to prepare a first polymer resin: mixing ethylene terephthalate and ethylene isophthalate in a ratio of 99: 1 to 70:30 Preparing a second polymer resin by adding a catalyst and a common additive, followed by copolymerization: melting and extruding the second polymer resin layer to form a second polymer resin layer on at least one side of the first polymer resin layer; and It is achieved by a method for producing a polymer film comprising the step of biaxially stretching the unstretched sheet.

In this invention, the polyester of a 1st polymer resin layer is obtained by polycondensing the acid component which has aromatic dicarboxylic acid as a main component, and the glycol component which has alkylene glycol as a main component. Specific examples of the aromatic dicarboxylic acid include dimethyl terephthalate, terephthalic acid, isophthalic acid, naphthalenedicarboxylic acid, cyclohexanedicarboxylic acid, diphenoxyethanedicarboxylic acid, diphenylcarboxylic acid and diphenyl ether dicarboxylic acid. Carboxylic acid, anstagendicarboxylic acid, α, β-4,4'-dicarboxylic acid, and the like, and dimethyl terephthalate and terephthalic acid are particularly preferable. Specific examples of the alkylene glycol include ethylene glycol, trimethylene glycol, tetramethylene glycol, pentamethylene glycol, hexamethylene glycol, and the like, and ethylene glycol is particularly preferable. The sulfonic acid metal salt derivative is an antistatic agent and its proper dosage is 0.01 to 1.0% by weight, more preferably 0.02 to 0.5% by weight based on the polyester resin. If it is less than 0.01% by weight fine bubbles are formed on the surface of the film, the physical properties of the film is lowered, and the antistatic property is not improved, if more than 1.0% by weight, the polyester is decomposed to significantly reduce the mechanical properties of the film.

Specific examples of the sulfonic acid metal salt of the general formula (1) include sulfonic acid metal salt derivatives or mixtures thereof, such as potassium octylbenzenesulfonate, potassium nonylbenzenesulfonate, and indeylbenzenesulfonate, but are not necessarily limited thereto.

The polymer film prepared by adding the sulfonic acid metal salt derivative having excellent heat resistance exhibits an excellent adhesion to the ink and the coating liquid due to the increased surface tension. In addition, since the static electricity, which is one of the causes of the loss of the recording information, is eliminated, it can be used as a high grade magnetic recording substrate.

The hindered phenolic compound in the present invention acts as a radical chain inhibitor in the thermal oxidation reaction of polyolefin. The proper amount of the compound is preferably 0.005 to 0.5% by weight based on the polyester resin. If the input amount is less than 0.005% by weight, the heat resistance of the polyolefin resin is hardly improved. If the input amount is more than 0.5% by weight, the thermal stability improvement effect is insignificant and only the manufacturing cost is increased.

Examples of the hindered phenol-based compound include tetrakis-3,5-di-tertbutyl-hydroxyphenylpropanoxymethylmethane, octadecyl-3-3,5-tertbutyl-4-hydroxyphenylpropanoate, 2 -Hydroxy-4-n-octylbenzophenone, 2,4-di-tertbutyl-3,5-di-tertbutyl-4-hydroxybenzoate or two or more kinds of these compounds can be mixed and used, It is not necessarily limited thereto.

The olefin resin in the present invention is 80 to 90% by weight, more preferably 85 to 97% by weight, based on the total amount of polyolefin resin, and the remainder thereof with at least one compound selected from ethylene, butene, pentene, hexene and octene. It is a high polymer. The polymer film is manufactured by extrusion molding and stretching by mixing the copolymerized polyolefin resin and the polyester resin. At this time, since the compatibility between the polyolefin resin and the polyester resin is poor, fine pores are formed on the surface and inside of the film. Performance and light weight can be achieved at the same time.

The copolymerization polyolefin resin preferably has a melt index in the range of 1.0 to 25 (g / 10 minutes), more preferably 2.5 to 15 (g / 10 minutes), in which the pores generated in the matrix are uniform in size. This is because it has a distribution with.

The mixing ratio of the polyolefin resin in the production of the polymer film is 5 to 35% by weight, more preferably 8 to 25% by weight relative to the first polymer resin.

In the present invention, the thickness of the first polymer resin layer is about 50 to 90% of the total polymer film thickness, and more preferably about 70 to 85%. In the case where the thickness of the first polymer resin layer exceeds 90% of the total film thickness, not only the formation of a uniform layer is difficult, but also the heat-sealing properties and the lamination properties are deteriorated. Its strength is lowered and its specific gravity is increased to give a stiff texture unlike paper.

The second polymer resin layer of the present invention consists of copolyesters having ethylene terephthalate and ethylene terephthalate as main repeating units, wherein ethylene isophthalate is contained in an amount of 1 to 30% by weight based on the second polymer resin.

Specific examples of the copolymerization component constituting the second polymer resin layer include diethylene glycol, propylene glycol, neopentyl glycol, polyethylene glycol, p-xylene glycol, 1,4-cyclohexanedimethinol, 5-sodiumsulfonyliso There exists a polytubular dicarboxylic acid component, such as ditarmic acid components, such as a phthalic acid, trimellitic acid, and pyromellitic acid.

The copolymerized polyester resin constituting the second polymer resin layer has a melting temperature of 190 to 230 ° C, more preferably 200 to 220 ° C. When the melting temperature is 190 ° C. or lower, the viscosity of the second polymer resin layer is smaller than that of the first polymer resin layer, so that co-extrusion causes culturing at the exit of the Ti-die. The contact surface becomes unstable, and as a result, the thickness of the polymer film becomes uneven.

In the present invention, known additives such as polycondensation catalysts, dispersants, electrostatic agents, crystallization accelerators, antiblocking agents, and other inorganic lubricants may be added within the scope of not impairing the effects of the present invention. . As the inorganic lubricant, barium sulfate, titanium dioxide, silicon dioxide, calcium carbonate, magnesium oxide and talc or two or more kinds of these compounds may be mixed and used. At this time, the addition amount of the inorganic lubricant is preferably 1 to 20% by weight. If it exceeds 20%, the mechanical properties of the film are lowered and it is difficult to reduce the weight.

Hereinafter, the present invention will be described in detail by examples. However, the present invention is not necessarily limited thereto.

The performance evaluation about the film of this invention was performed by the following method.

1) Melt Index

According to the resin melt index measurement method according to ASTM D1238 it was measured as follows.

After filling the polymer film of the present invention in a cylinder heated to 230 ° C (nozzle inner diameter 2.09mm, length 8mm) and subjected to a load of 2160kg to measure the amount of resin passed by the minute unit and converted to the amount passed in 10 minutes .

2) melting temperature

The melting temperature of the resin was measured using a differential thermal analyzer (DSC-7 from Perkin Elmer). The temperature was raised to 300 ° C to melt the sample, followed by quenching, and then raising the temperature (temperature rising rate: 20 ° C / min) again. It was one.

3) apparent density

The density gradient tube filled with carbon tetrachloride and normal heptane was measured by the ups and downs method (25 degreeC).

4) Antistatic property (antistatic property, surface resistance measurement)

The surface resistance (unit: ohms) was measured using the insulation resistance measuring device of the US Hewlett Packard company (20 degreeC, 65% relative humidity, 500V applied voltage).

5) Heat Sealing Characteristics

The film was placed on a rod heated to 140 ° C., pressed for 1 second at a pressure of 3 kg / mm², and then subjected to a 180 degree peeling test to measure peel strength. The characteristics were identified by observing the occurrence of wrinkles, shrinkage of the film, and cloudiness during the processing.

6) Laminate Properties

An iron sheet containing no tin was heated to 290 ° C., and then a polymer film was placed thereon, followed by laminating (120 m / min) under a pressure of 5 kg / mm² between rubber rolls made of silicon. Cooling water was sprayed and quenched, stretched by 1% and subjected to 180 degree peeling experiment. The characteristics were identified by observing the occurrence of wrinkles, shrinkage of the film, and cloudiness during the processing.

7) process stability

The incidence of breakage of the film for 24 hours was measured and labeled A. B. C. and D.

A: 1 or less times. B: 1 to 5 times.

C: 5-10 times. D: 10 times or more.

8) film thickness

The thickness of each tooth of the polymer film was measured using a scanning microscope (SEM).

Example 1

Resin which comprises a 1st polymer resin layer was manufactured as follows. First, a mixture of dimethyl terephthalate and ethylene glycol mixed at a ratio of 1 to 2 was subjected to transesterification to produce an ethylene terephthalate (bis-2-hydroxyethyliterephalate) monomer. Here, 5 weight% of titanium dioxide (cubic crystal structure, average particle diameter: 0.5 micrometer) with respect to polyester resin, 0.20 weight% of tetrakis-3,5- di-tert-butylhydroxy propanomethyl methane, and potassium octylbenzene sulfonate After adding 0.20% by weight and a conventional catalyst, a polycondensation reaction was performed to prepare a polyester having an intrinsic viscosity of 0.610 dl / gr. The first polymer resin was prepared by mixing the prepared polyester and random polypropylene-ethylene co-polymer resin (melt index: 4.0) at 80:20 (wt%) and then compounding the compound.

The second polymer resin layer was prepared by mixing a glycol component having 1% polyethylene glycol and 99% ethylene glycol in a 1: 2 equivalent ratio to an acid component composed of 15% isophthalic acid and 85% terephthalic acid and then polymerizing the same. It formed from polyester (intrinsic viscosity: 0.58 dl / gr. Melting temperature: 212 degreeC).

The resin constituting the first polymer resin layer and the second polymer resin layer was dried in a vacuum for 10 hours using a dryer (moisture content: 0.005%), and then extruded using a T-die equipped with two extruders and a feeder block. And quenched on a cooling roll cooled to 30 ° C. to obtain a laminated sheet. The sheet thus obtained was stretched 3.5 times in the longitudinal direction and 3.5 times in the transverse direction to prepare a biaxially stretched polymer film (thickness: 38 mu).

The physical properties such as density, surface resistance, and breaking strength of the polymer film prepared by the above method were measured, and heat sealing properties and laminate properties.

As can be seen from Table 1, the film produced by the above method had a breakage phenomenon of less than one time during the manufacturing process of 24 hours, and had excellent physical properties such as apparent density, surface resistance, and film breaking strength.

The defects such as wrinkles did not occur during heat sealing processing, and the peeling test showing the laminate processing characteristics showed that the film was not peeled off and fractured, so that the adhesive strength was higher than that of the breaking strength, and wrinkles, shrinkage and turbidity were also observed. It wasn't.

Example 2-5

In the same manner as in Example 1, the thickness of the first polymer resin layer and the second polymer resin layer or the content of added isophthalic acid was changed within a range satisfying the conditions of the present invention.

As can be seen from Table 1, the physical properties, heat sealing properties, and laminate properties of the films produced by the above method were generally good.

Example 1-4

In the same manner as in Example 1, the thickness of the first polymer resin layer and the second polymer resin layer of the film and the content of isophthalic acid were changed within the scope of the present invention. That is, in Comparative Examples 1, 2 and 3, the addition amount of isophthalic acid is out of the range of 1 to 30% by weight, and in Comparative Example 4, the thickness of the first polymer resin layer is 50 to 90% of the thickness of the entire film. It is out of the case.

As can be seen from Table 1, in Comparative Example 1, no adhesion occurred during heat sealing and laminate processing, and in Comparative Example 2-4, heat sealing and laminate processing characteristics were generally poor.

As can be seen from the above, the polymer resin film produced by the present invention has good antistatic properties and printability, and has excellent heat sealing and laminate processing characteristics, and thus can be used in various fields such as packaging and industrial use.

Claims (12)

A polymer resin film comprising a first polymer resin layer and a second polymer resin layer formed on at least one surface thereof. The first polymer resin layer comprises from 0.01 to 0.1% by weight of a sulfonic acid metal salt, from 0.005 to 0.5% by weight of a hindered phenolic compound, and from 1 to 20% by weight of an inorganic lubricant; 95 wt%) and polyolefin resin (5 to 35 wt%), and the second polymer resin layer contains copolyester having ethylene terephthalate and ethyl rayophthalate as the main repeating unit. Polymer film made. The polymer film according to claim 1, wherein the second polymer resin layer contains a copolyester having 1 to 30% by weight of ethylene isophthalate as a main repeating unit. The polymer film of claim 1, wherein the polymer film has a specific gravity of 0.9 to 1.2. The polymer film according to claim 1, wherein the thickness of the first polymer resin layer is 50 to 90% of the total polymer film thickness. The polymer film according to claim 1, wherein the sulfonic acid metal salt derivative (acid value of 1.0 mg KOH / g or less) is a compound represented by the following formula (1): R₁-SO ₃ Me (1) Is a C ₅ -C ₂₀ alkyl group and Me is an alkaline earth metal or alkali metal selected from the group consisting of Li, Na, K, and Mg. The polymer film of claim 1, wherein the inorganic lubricant is at least one selected from barium sulfate, titanium dioxide, silicon dioxide, calcium carbonate, magnesium oxide, and talc. The method of claim 1, wherein the polyolefin resin is a copolymer of a propylene component (80 to 99% by weight) and at least one line segment (1 to 20% by weight) selected from the group consisting of ethylene, butene, pentene, hexene and octene. Polymer film made. The method of claim 1, wherein the hindered compound is tetrakis-3,5-di-tertbutyl-hydroxyphenylpropaneoxymethylmethane, octadecyl-3-3,5-tertbutyl-4-hydroxyphenylprop At least one selected from the group consisting of panate, 2-hydroxy-4-n-octylbenzophenone, 2,4-di-tertbutyl-3,5-di-tertbutyl-4-hydroxybenzoate Polymer film characterized. The polymer film according to claim 1, wherein the melting temperature of the copolyester of the second polymer resin layer is in the range of 190 to 230 ° C. To polycondensed pulley ester resin (65 to 95% by weight) formed from 0.01 to 1.0% by weight of sulfonic acid metal salt, 1 to 20% by weight of inorganic lubricant, and 0.005 to 0.5% by weight of hindered phenolic compound based on polyester resin Compounding a polyolefin resin (5-35% by weight) to prepare a first polymer resin: Mixing ethylene terephthalate and ethylene isophthalate in a 99: 1 to 70:30 weight ratio and adding a conventional catalyst, additives Preparing a second polymer resin by copolymerization: melting and compressing the second polymer resin layer to form a second polymer resin layer on at least one surface of the first polymer resin layer; and biaxially stretching the unstretched sheet. Method for producing a polymer film, characterized in that it comprises a step. The method of claim 10, wherein the biaxial stretching is 2 to 5 times in the longitudinal direction and 2 to 5 times in the transverse direction. The method for producing a polymer film according to claim 10, wherein a melt index of the polyolefin resin is 1.0 to 25 (g / 10 min).