JP2007307708A - Laminated film made of thermoplastic resin and packaging bag made of the film - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a laminated film made of a thermoplastic resin which is excellent in sliding properties, opening properties, transparency, hygienic properties, etc., is suitable for the raw material of a food packaging bag and a medical supply packaging bag, and is produced by an inflation method and a packaging bag produced from the film. <P>SOLUTION: In the first invention, the thermoplastic resin laminated film in which at least two thermoplastic resin layers are laminated and which is produced by the inflation method is provided. The content of a lubricant in the shape of fine particles incorporated in the thermoplastic resin (A) constituting the outermost layer of the laminated film is 0.01-5.0 wt.%, and the ratio [(d<SB>(C)</SB>)/(d<SB>(A)</SB>)] between the mean particle size (d<SB>(C)</SB>) of the lubricant and the thickness (d<SB>(A)</SB>) of the thermoplastic resin (A) constituting the outermost layer is 1.0-4.0. In the second invention, the packaging bag produced from the laminated film of the first invention is provided. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

The present invention relates to a laminated film made of a thermoplastic resin and a packaging bag made of the film. Specifically, when used as a packaging bag, it is excellent in slipperiness, openness, transparency, etc., and even if the article stored in the packaging bag is a liquid material, the components blended in the layers constituting the packaging bag are The present invention relates to a laminated film made of a thermoplastic resin manufactured by an inflation method, which does not melt or leave a stored article and is excellent in hygiene, and a packaging bag manufactured from this film.

In recent years, packaging bags manufactured from thermoplastic resin films have been widely used in various applications such as food and medical use. Among these uses, food and medical packaging bags are slippery (ease of taking out one packaging bag from a plurality of stacked packaging bags) and openability (stores articles in the packaging bag). It is necessary to have various characteristics such as ease of opening of the opening), hygiene, gas barrier properties, transparency, flexibility, heat resistance, and pinhole resistance. In order to obtain a film having these characteristics, a multilayer film obtained by laminating a plurality of resins exhibiting different characteristics has been proposed and put into practical use. These laminated films are mainly produced by an inflation method.

However, the inflation method is a method of flattening a cylindrical film in which a plurality of resins are extruded from an annular die and winding it into a roll shape to produce a laminated film, so the laminated film wound into a roll shape is Depending on the pressure at the time of winding and the weight of the roll itself, the contact surfaces of the film may adhere to each other (blocking). Therefore, (1) it is difficult to rewind the laminated film wound into a roll shape when producing a packaging bag, and (2) when using a plurality of produced packaging bags after being stacked, stored and transported. It is difficult to take out a single packaging bag from a plurality of stacked packaging bags, and (3) it is difficult to open an opening when storing articles in the packaging bag. There were disadvantages such as need.

As a technique for eliminating such drawbacks and improving the opening property of a laminated film produced by an inflation method, Patent Document 1 describes a technique of blending a specific ethylene polymer with polyethylene as a raw material resin. ing. However, since raw material resins, production conditions, and the like are limited, there is a drawback that they are poor in practicality and versatility.

Further, as another technique for improving the opening property of a laminated film produced by an inflation method, a technique is known in which an organic compound lubricant (anti-blocking agent) such as fatty acid amide is blended with a thermoplastic resin. However, when it is used as a packaging bag, if a liquid lubricant is blended in the innermost layer that comes into contact with the stored article, it dissolves into or disengages from the article containing the lubricant (particularly in the case of a liquid product). It is not suitable for food or medical use.

Furthermore, Patent Document 2 describes a method of blending an antiblocking agent composed of fine particles in one surface layer in a laminated film. However, according to the experiments by the present inventors, it was difficult to peel off the laminated film described in the examples at the interface between the innermost layers facing each other, and it could not be said that the opening property was excellent. For this reason, the laminated film by the inflation method excellent in all the characteristics, such as slipperiness, opening property, transparency, and hygiene, was desired.
JP-A-11-90981 JP 2006-15605 A

In view of the above circumstances, the present inventors have completed as a result of intensive studies to provide a laminated film made of a thermoplastic resin by an inflation method that has solved the above-mentioned drawbacks, and a packaging bag made of this film. is there. That is, the object of the present invention is as follows.
1. To provide a laminated film made of a thermoplastic resin produced by an inflation method, which is excellent in slipperiness, openness, transparency, hygiene and the like, and is suitable as a raw material for food and medical packaging bags.
2. To provide a packaging bag that is excellent in slipperiness, openness, transparency, hygiene, and the like, and that is suitable as a packaging bag for food and medical use, and is manufactured from the above laminated film made of thermoplastic resin.

In the present invention, in order to solve the above-mentioned problem, in the first invention, a laminated film in which at least two layers of thermoplastic resins are laminated, and the fine particles blended in the thermoplastic resin (A) constituting the outermost layer. The amount of the lubricant (C) is 0.01 to 5.0% by weight, and the average particle diameter (d _(C) ) of the fine granular lubricant (C) and the thermoplastic resin (A ) Ratio of thickness (d _(A) ) to {(d _(C) ) / (d _(A) )} is 1.0 to 4.0 and manufactured by an inflation method. There is provided a laminated film made of a thermoplastic resin.

According to a second aspect of the present invention, there is provided a packaging bag manufactured using the thermoplastic resin laminated film according to the first aspect of the present invention as a raw material.

The present invention is as described in detail below, has the following particularly advantageous effects, and its industrial utility value is extremely great.
1. In the thermoplastic resin laminated film according to the present invention, the fine granular lubricant (C) is blended in the thermoplastic resin layer (A) constituting the outermost layer, so that the laminated film is left in a roll shape. However, since the contact surfaces {(A) layer} of the film are difficult to adhere to each other, there are disadvantages such as difficulty in rewinding when producing a packaging bag by rewinding the laminated film wound in a roll shape. There is no workability.
2. The laminated film made of thermoplastic resin according to the present invention has an average particle diameter (d _(C ) of the fine granular lubricant (C) from the thickness (d _(A) ) of the thermoplastic resin layer (A) constituting the outermost layer. ₎ ) Is larger, and the unevenness of the thermoplastic resin layer (A) constituting the outermost layer due to the fine granular lubricant (C) is caused by the winding pressure generated by winding in a roll shape. Since irregularities also appear on the surface of the thermoplastic resin layer (B) constituting the innermost layer, it can be easily peeled off at the interface of the thermoplastic resin layer (B) constituting the opposed innermost layer and exhibits excellent opening properties.
3. Even if a plurality of the packaging bags made of the thermoplastic resin laminated film according to the present invention are stacked, the packaging bags do not adhere to each other, and one packaging bag can be easily taken out.
4). In the packaging bag made of the thermoplastic resin laminated film according to the present invention, the fine granular lubricant (C) is blended only in the thermoplastic resin layer (A) constituting the outermost layer. The product does not melt into or leave the article (liquid) filled with, and exhibits excellent hygiene.
5). Since the packaging bag made of the thermoplastic resin laminated film according to the present invention is excellent in transparency and hygiene, it is suitable as a packaging bag for food and medical use.

Hereinafter, the present invention will be described in detail. The laminated film made of thermoplastic resin according to the present invention comprises a multilayer film in which at least two thermoplastic resins are laminated, and the outermost layer is a thermoplastic resin layer (A) {hereinafter referred to as the outermost layer (A)}. It is essential that the innermost layer is composed of the thermoplastic resin layer (B) {hereinafter referred to as the innermost layer (B)}, and the outermost layer (A) is blended with a fine granular lubricant (C). . In the present invention, it is essential to laminate two or more layers of thermoplastic resin films when the fine granular lubricant (C) is blended in the outermost layer (A) and used as a packaging bag. There is a problem of contamination of stored articles (especially foods, medicines, medical supplies) that are caused by elution of fine granular lubricant (C) in articles (especially liquid) stored in the packaging bag without adhesion between the bags. This is to make it difficult. Further, the resin of the outermost layer (A) and the innermost layer (B) is made different so that the function of each layer can be changed. For example, when the innermost layer (B) is a sealant layer, a packaging bag can be manufactured by heat-sealing a film manufactured by an inflation method.

The thermoplastic resin used for the outermost layer (A) and the innermost layer (B) constituting the laminated film according to the present invention can produce a film by an inflation method, and has been conventionally known as a thermoplastic resin. If it is resin, there will be no restriction | limiting in particular. Examples of such thermoplastic resins include polyester resins, polyamide resins, polyolefin resins, polycarbonate resins, and thermoplastic elastomers.

The polyester resin used in the present invention is a polyester resin having a butylene terephthalate repeating unit as a main component, and includes 1,4-butanediol as a polyhydric alcohol component, and, if necessary, other than 1,4-butanediol. Using polyhydric alcohol, terephthalic acid or an ester-forming derivative thereof as a polyvalent carboxylic acid component, and if necessary, a polyvalent carboxylic acid other than terephthalic acid or an ester-forming derivative thereof, and obtaining the resulting butylene terephthalate unit It is a polyester resin having a main repeating unit. The main component of the repeating unit means that the butylene terephthalate unit is 50 mol% or more in the total polyvalent carboxylic acid-polyhydric alcohol unit. The above range is preferably 60 mol% or more, more preferably 70 mol% or more, and particularly preferably 80 mol% or more.

Examples of the polyvalent carboxylic acid component other than terephthalic acid used in the production of the polyester resin include an aromatic polyvalent carboxylic acid, an aliphatic polyvalent carboxylic acid, an alicyclic polyvalent carboxylic acid, or the above polyvalent carboxylic acid. Examples thereof include ester-forming derivatives. Examples of the aromatic polycarboxylic acid include 2,6-naphthalenedicarboxylic acid, isophthalic acid, phthalic acid, trimesic acid, trimellitic acid, and the like. Examples of the aliphatic polycarboxylic acid include oxalic acid, malonic acid, and succinic acid. Examples include acids, glutaric acid, adipic acid, suberic acid, azelaic acid, sebacic acid, and decanedicarboxylic acid, and examples of the alicyclic polyvalent carboxylic acid include cyclohexanedicarboxylic acid. Examples of the ester-forming derivative of the polyvalent carboxylic acid include lower alkyl esters such as dimethyl terephthalate. These polyvalent carboxylic acid components may be used alone or in a mixture of two or more.

On the other hand, examples of polyhydric alcohol components other than 1,4-butanediol include fatty acid polyhydric alcohols, alicyclic polyhydric alcohols, aromatic polyhydric alcohols, and polyalkylene glycols. Examples of fatty acid polyhydric alcohols include ethylene glycol, diethylene glycol, propylene glycol, neopentyl glycol, pentanediol, hexanediol, glycerin, trimethylolpropane, and pentaerythritol. Aliphatic polyhydric alcohols include 1,4. -Cyclohexanedimethanol and the like, aromatic polyhydric alcohols such as bisphenol A and bisphenol Z, and polyalkylene glycols such as polyethylene glycol, polypropylene glycol, polytetramethylene glycol, and polytetramethylene oxide glycol Is mentioned. These polyhydric alcohol components may be used alone or in a mixture of two or more.

The polyester resin can be produced by a conventionally known method such as a melt polymerization method, and a catalyst and a reaction aid can be used in an esterification reaction and / or a polycondensation reaction. As the catalyst, a titanium compound is usually used, and examples thereof include titanium alcoholate, titanium phenolate, and an inorganic titanium compound. Examples of the titanium alcoholate include tetramethyl titanate, tetraisopropyl titanate, and tetrabutyl titanate. Examples of the titanium phenolate include tetraphenyl titanate. Examples of the inorganic titanium compound include titanium oxide and titanium tetrachloride. It is done. Examples of the reaction aid include tin compounds, magnesium compounds, calcium compounds, antimony compounds, germanium compounds, manganese compounds, zinc compounds, zirconium compounds, cobalt compounds, phosphate compounds, sodium compounds, and the like.

The polyester resin may be a mixture in which other polyester resins having different terminal carboxyl group concentrations, melting points, catalyst amounts and the like are mixed as long as the object of the present invention is not impaired. Other polyester resins include polyethylene terephthalate (PET), polytrimethylene terephthalate (PTT), polynaphthalene terephthalate (PEN), poly (1,4-cyclohexanedimethylene terephthalate) (PCT), liquid crystalline polyester, Some of the monomers of valolactone, poly (ε-caprolactone), their copolymers, and their main constituent components are made from different monomers such as isophthalic acid, dimer acid, polyalkylene glycol such as polytetramethylene glycol, and bisphenol. Substituted and copolymerized ones are listed.

The polyester resin preferably has an intrinsic viscosity in the range of 0.7 to 2.0 dl / g. If the intrinsic viscosity is less than 0.7 dl / g, the mechanical strength of the laminated film is lowered, and if it exceeds 2.0 dl / g, the amount of extrusion from the die is reduced and the take-off speed is lowered. . A more preferable range of the intrinsic viscosity is 0.8 to 1.8 dl / g, and a more preferable range is 1.0 to 1.6 dl / g. In the present invention, the intrinsic viscosity is a value calculated from a solution viscosity measured using a mixed solvent of phenol and 1,1,2,2-tetrachloroethane (weight ratio 1: 1, temperature 30 ° C.). is there.

Examples of the polyamide-based resin used in the present invention include (1) a lactam having three or more members, (2) a polymerizable ω-amino acid, and (3) a polyamide obtained by polycondensation of diamine and dicarboxylic acid. Can be mentioned. (1) Examples of the lactam having 3 or more members include ε-caprolactam, aminocaproic acid, enantolactam, α-pyrrolidone, α-piperidone, and (2) the polymerizable ω-amino acid is 6-aminohexane. Acid, 7-aminoheptanoic acid, 11-aminoundecanoic acid, 9-aminononanoic acid and the like. (3) Examples of diamines include hexamethylenediamine, nonamethylenediamine, undecamethylenediamine, dodecamethylenediamine, metaxylylene diene. Examples of the dicarboxylic acid include terephthalic acid, isophthalic acid, adipic acid, sebacic acid, dodecane dibasic acid, glutaric acid, and the like. The resulting copolymer may be used. Polyamide resins obtained from the above raw materials include polyamide (PA) 4, 6, 7, 8, 11, 12, 6, 6, 6, 10, 6, 11, 6, 12, MXD6, 6T, 6/6. -6, 6/12, 6 / 6T, 6I / 6T, 9T etc. are mentioned. Here, “·” means a combination of monomer components and means a “/” copolymer.

The polyamide-based resin can be produced by a conventionally known method such as a melt polymerization method, and the molecular weight is not particularly limited, but the relative viscosity is preferably in the range of 2.5 to 6.5. If the relative viscosity is less than 2.5, the drawdown is large, and it may be difficult to form a laminated film. If the relative viscosity exceeds 6.5, productivity is remarkably lowered, which is not preferable. The relative viscosity is preferably in the range of 3.0 to 6.0 in the above range. In the present invention, the relative viscosity is a value when 1 g of polyamide resin is dissolved in 100 ml of 98% sulfuric acid and measured at 25 ° C. in accordance with JIS K6810.

The polyolefin resin used in the present invention may be obtained by a polymerization reaction or a modification reaction by a conventionally known method. Specifically, high-density polyethylene (HDPE), medium-density polyethylene ( MDPE), low density polyethylene (LDPE), polypropylene (PP), ethylene-vinyl acetate copolymer (EVA), ethylene-methacrylate copolymer, ethylene-ethyl acrylate copolymer, ethylene-ethyl methacrylate copolymer , Ionomer resin, saponified ethylene-vinyl acetate copolymer (EVOH), modified polyolefin resin (APO), linear low density polyethylene (L-LDPE), and the like. The melt flow rate (MFR) of the polyolefin resin is preferably in the range of 0.01 to 250 g / 10 minutes. In the present invention, the melt flow rate (MFR) is a value measured according to JIS K6922.

The polycarbonate resin used in the present invention is obtained by reaction of various dihydroxyaryl compounds with phosgene (phosgene method), or obtained by transesterification of dihydroxyaryl compounds and diphenyl carbonate (transesterification). Law). A typical polycarbonate resin is a polycarbonate obtained by the reaction of 2,2'-bis (4-hydroxyphenyl) propane and phosgene. The weight average molecular weight of the polycarbonate resin is preferably in the range of 15,000 to 35,000. Examples of the thermoplastic elastomer used in the present invention include a styrene thermoplastic elastomer, an olefin thermoplastic elastomer, an ester thermoplastic elastomer, an amide thermoplastic elastomer, and an olefin / diene thermoplastic elastomer.

The above thermoplastic resins may be used alone or as a mixture of two or more. The thermoplastic resin of the outermost layer (A) and the innermost layer (B) may be the same, but if different thermoplastic resins are used, the functions exhibited in each layer will be different and the functionality can be improved. preferable. Among the above thermoplastic resins, polyester resins, polyamide resins, and polyolefin resins are preferable. Particularly, the outermost layer (A) is preferably polybutylene terephthalate (excellent in transparency, heat resistance, and gas barrier properties). PBT), polybutylene terephthalate-polytetramethylene glycol copolymer (S-PBT), and polyamide 6 (PA6).

  The fine granular lubricant (C) used in the present invention functions to impart appropriate irregularities to the surface of the laminated film and to exhibit slipperiness (blocking resistance) and opening properties when used as a packaging bag. To do. The fine granular lubricant (C) is selected from organic fine particles or inorganic fine particles. Organic fine particles include polystyrene, polyethylene, polyamide, polyester, polyacrylic acid ester, polymethacrylic acid ester, epoxy resin, polyvinyl acetate, polyvinyl chloride and other homopolymers, and copolymers of these resins. Can be mentioned. These organic fine particles may be those crosslinked with a crosslinking agent (crosslinked polymer fine particles). Examples of the inorganic fine particles include talc, kaolin, silica, calcium carbonate, glass powder, calcium oxide, zeolite, amorphous aluminosilicate, titanium oxide, alumina, barium sulfate, aluminum sulfate, and magnesium hydroxide. These fine particles may be used alone or in a mixture of two or more. The fine granular lubricant (C) is preferably polyacrylic acid ester or polymethacrylic acid ester fine particles, and these cross-linked polymer fine particles, considering the strength of the fine particles and the transparency when formed into a laminated film. Of these, cross-linked polymethyl methacrylate fine particles are particularly preferable.

The average particle diameter (d _(C) ) of the fine granular lubricant (C) is the thickness (d) of the outermost layer (A) to be described later because the laminated film according to the present invention is produced and used substantially unstretched. _{(A) In} consideration of ₍ ), it is preferable to select in the range of 3 to 25 μm. In the above range, 5 to 20 μm is more preferable, and 7 to 15 μm is more preferable. In addition, the calculation method of the average particle diameter (d _(C) ) of a fine granular lubricant (C) is as follows. First, only the outermost layer (A) resin was discharged from the annular die, and a small amount of molten resin was collected. The collected resin was cooled to room temperature, and the resin was dissolved with HFIP (hexafluoroisopropanol). Next, this solution was cast on a glass plate and the solvent was removed by air drying. Then, the particle diameter of 200 fine granular lubricants (C) was measured by a scanning electron microscope (SEM), and the average value was determined as the average particle size. The diameter (d _(C) ) was used.

The blending amount of the fine granular lubricant (C) is selected in the range of 0.01 to 5.0% by weight with respect to the outermost layer (A). When the blending amount of the fine granular lubricant (C) is less than 0.01% by weight, moderate unevenness cannot be imparted to the surface of the thermoplastic resin laminated film according to the present invention. On the other hand, when the packaging bag is made inferior in opening property, etc., on the other hand, when it exceeds 5.0% by weight, the transparency of the laminated film is inferior, the fine granular lubricant (C) is detached from the outermost layer (A), The fine granular lubricant (C) may be powdered (bleeded) on the surface of the outermost layer (A). In the above range, 0.03 to 4.0% by weight is preferable, and 0.05 to 3.0% by weight is particularly preferable.

In the present invention, the blending amount of the fine granular lubricant (C) is within the above range, and the average particle diameter (d _(C) ) of the fine granular lubricant (C) and the thickness of the outermost layer (A). the ratio of the _{(d (a)) {(} d (C)) / (d (a))} to the range of 1.0 to 4.0. When {(d _(C) ) / (d _(A) )} is less than 1.0, the fine granular lubricant (C) is buried in the outermost layer (A), and moderate irregularities are formed on the surface of the laminated film. Therefore, the slipperiness of the laminated film and the opening property when formed into a packaging bag are inferior, and if it exceeds 4.0, the fine granular lubricant (C) may be detached from the outermost layer (A). This is undesirable because it impairs hygiene. The above range is preferably 1.1 to 3.0, and more preferably 1.2 to 2.5.

When the thermoplastic resin laminated film according to the present invention is then heat-sealed to form a packaging bag, it is preferable to provide a sealant layer on the innermost layer (B). A sealant layer is a layer made of a thermoplastic resin suitable for heat sealing when a laminated film is processed into a packaging bag. For example, even when the film is formed on a cylindrical laminated film, or when the laminated film formed into a cylindrical shape is cut open to form a sheet, the two sealant layers may be opposed to each other and heat sealed. The thermoplastic resin used for forming the sealant layer is made of LDPE resin and / or L-LDPE resin. The LDPE resin has a density of 0.910 to 0.925 g / cm ³ and means a polymer obtained by polymerizing ethylene by a high pressure method. The L-LDPE resin means an ethylene / α-olefin copolymer having a density of 0.918 to 0.940 g / cm ³ , and examples of the α-olefin include butene-1, pentene-1, 4-methylbutene. -1, hexene-1, 4-methylpentene-1, heptene-1, octene-1, decene-1, undecene-1, dodecene-1, and the like. The content of the α-olefin to be copolymerized is selected from the range of 0.5 to 10 mol%. The thickness of the sealant layer is preferably 30 μm or more. In addition, in this invention, in order to improve opening property more, it does not prevent adding a small amount of fine granular lubricants (C) as described above also to the innermost layer (B). However, the upper limit of this small amount range is that the elution of the fine granular lubricant (C) from the innermost layer (B) into the packaged bag is hardly problematic.

In the thermoplastic resin laminated film according to the present invention, an intermediate layer can be provided between the outermost layer (A) and the innermost layer (B) as necessary. Examples of the thermoplastic resin used for forming the intermediate layer include polyamide resins such as PA6 having excellent gas barrier properties, saponified ethylene-vinyl acetate copolymer (EVOH), and the like.

The thermoplastic resin laminated film according to the present invention has an interface between the outermost layer (A) and the innermost layer (B), or any of these layers and the intermediate layer provided as necessary. In order to improve the adhesion between the layers, an adhesive layer made of the thermoplastic resin can be provided on each. Preferred as the thermoplastic resin used in the adhesive layer is a modified polyolefin resin (APO). APO is a resin produced by copolymerizing and / or graft-polymerizing an α, β-unsaturated carboxylic acid or a derivative thereof to a polyolefin resin mainly composed of ethylene and / or propylene.

The thermoplastic resin used for the outermost layer (A), the innermost layer (B), the intermediate layer, and the adhesive layer is coated with various resin additives (D) as long as the objects and effects of the present invention are not impaired. Can be blended. Examples of the various resin additives (D) that can be blended include antioxidants, heat stabilizers, antistatic agents, ultraviolet absorbers, pigments, and dyes. However, since the innermost layer (B) is in contact with the article stored when it is used as a packaging bag, the resin additive (D) blended in the innermost layer (B) is powdered (bleeding) on the surface of the innermost layer (B). It is necessary to select one that does not bleed out.

Next, a method for producing the thermoplastic resin laminated film according to the present invention will be described. The thermoplastic resin laminate film according to the present invention must be manufactured by an inflation method. The inflation method may be a conventionally known method. For example, the thermoplastic resin constituting the outermost layer (A) and the innermost layer (B) melted by two extruders is formed into a ring for coextrusion. A tubular film is formed by guiding the die to the die, extruding the molten resin into a cylindrical shape from an annular die lip, expanding it, cooling and solidifying it with a cooling device, guiding it to a guide plate, flattening it with a nip roll, and winding it into a roll. When one end or both ends are cut open, a two-layer laminated film is obtained. Moreover, when providing an intermediate | middle layer and an adhesive bond layer, an extruder is expanded and a cyclic | annular die | dye is replaced | exchanged and the laminated film of 3 layers or more is obtained by the procedure similar to the above. As a method of cooling and solidifying with the cooling device, there are two types, (1) a water cooling method for cooling by contacting with water, and (2) an air cooling method for cooling by air, and considering the transparency of the resulting laminated film The water cooling method is preferred. In addition, since the laminated film obtained by the inflation method is substantially an unstretched film, JIS
It is preferable that the heat shrinkage measured in accordance with K6734 is 10% or less in both the extrusion direction (MD) and the direction perpendicular to the extrusion direction (TD).

The thickness of each layer of the laminated film is preferably 1 to 100 μm for the outermost layer (A) and 10 to 200 μm for the innermost layer (B). The total thickness of the laminated film is preferably 10 to 300 μm and not more than 50 times the thickness (d _(A) ) of the outermost layer (A). When it exceeds 50 times, since the unevenness does not appear on the surface of the innermost layer (B), the innermost layers (B) facing each other are easily adhered (blocking) to each other, and the opening property is inferior when used as a packaging bag. . More preferred is 30 times or less, and even more preferred is 20 times or less. Although the thickness of an intermediate | middle layer and an adhesive bond layer is not restrict | limited unless the objective and effect of this invention are impaired, 1-100 micrometers is preferable, More preferably, it is 2-50 micrometers, More preferably, it is 3-25 micrometers. The thickness of the outermost layer (A) etc. of the laminated film is, for example, by cutting a piece of the laminated film and taking a photograph of the piece magnified 2000 times using a scanning electron microscope, (A) It can be calculated by measuring fragments (thicknesses) such as portions with JIS grade 1 calipers.

In the thermoplastic resin laminated film according to the present invention, the coefficient of dynamic friction on the surface of the outermost layer (A) is preferably 0.40 or less. The dynamic friction coefficient in the present invention is a value measured according to ASTM-D1894. When the coefficient of dynamic friction exceeds 0.40, the slipperiness is inferior, and it becomes difficult to slip at the interface of the outermost layer (A) facing to each other. Absent. More preferred is 0.35 or less, and further preferred is 0.30 or less.

The packaging bag which concerns on 2nd invention of this invention can be manufactured by the conventionally known method from the thermoplastic resin laminated | multilayer film which concerns on this invention. For example, a roll-shaped laminated film is rewound, cut to a predetermined size in a direction perpendicular to the extrusion direction (TD), and one opening portion along the direction perpendicular to the extrusion direction (TD). A packaging bag can be manufactured by (1) a method of heat-sealing the innermost layers (B), (2) a method of attaching using an adhesive, and the like. The other opened side can be cut or provided with unevenness on the cut surface or attached with a seal member such as a chuck according to the purpose of use of the packaging bag.

EXAMPLES Hereinafter, although an Example demonstrates this invention in detail, this invention is not limited to a following example, unless the summary is exceeded. As the raw material, commercially available materials having the following characteristics are used, and the evaluation items of the thermoplastic resin laminated film and the packaging bag made of this film are as follows.

<Raw material>
In the present invention, MFR is a value measured according to JIS K6922, and melting point is a value measured according to JIS K7121.
(1) S-PBT: Polybutylene terephthalate having a tetramethylene glycol (number average molecular weight of 1000) content of 10% by weight, an intrinsic viscosity of 1.15 and a melting point of 219 ° C.
(2) PA6: Polyamide 6 (trade name: Polyamide 6 extrusion grade 1030J, manufactured by Mitsubishi Engineering Plastics Co., Ltd.) having a relative viscosity of 4.5.
(3) L-LDPE: Linear low density polyethylene resin (trade name: UF230, manufactured by Nippon Polyethylene Co., Ltd.) having an MFR of 1.1 (g / 10 min) and a melting point of 124 ° C.
(4) APO (1): Maleic anhydride-modified LLDPE (trade name, manufactured by Mitsubishi Chemical Corporation) having an MFR of 1.0 (g / 10 min), a density of 0.90 (g / cm ³ ), and a melting point of 119 ° C. : M512VF).
(5) APO (2): maleic anhydride-modified LLDPE (trade name, manufactured by Mitsubishi Chemical Corporation) having an MFR of 0.8 (g / 10 min), a density of 0.92 (g / cm ³ ), and a melting point of 122 ° C. : M132B).

(6) PMMA particles (a): Cross-linked polymethyl methacrylate fine particles having a mean particle size (d _(C) ) of 13 μm (product name: Eposta MA1013, manufactured by Nippon Shokubai Co., Ltd.).
(7) PMMA particles (b): cross-linked polymethyl methacrylate fine particles (manufactured by Nippon Shokubai Co., Ltd., trade name: Eposta MA1010) having an average particle diameter (d _(C) ) of 10 μm.
(8) PMMA particles (c): cross-linked polymethyl methacrylate fine particles having a mean particle diameter (d _(C) ) of 6 μm (product name: Eposta MA1006, manufactured by Nippon Shokubai Co., Ltd.).
(9) PMMA particles (d): cross-linked polymethyl methacrylate fine particles having a mean particle diameter (d _(C) ) of 2.5 μm (trade name: Eposta MA1002 manufactured by Nippon Shokubai Co., Ltd.).
(10) Zeolite: Zeolite with a mean particle size (d _(C) ) of 7 μm (trade name: Shilton JB70, manufactured by Mizusawa Chemical Co., Ltd.).
(11) Talc: talc (trade name: Micron White 5000, manufactured by Hayashi Kasei Co., Ltd.) having an average particle size (d _(C) ) of 2.8 μm.
(12) EA: erucic acid amide (Nippon Kasei Co., Ltd., trade name: Diamond L200).

<Evaluation items>
(1) Sliding property: Cylindrical laminated films obtained in Examples and Comparative Examples were left in a roll shape in a room at a temperature of 23 ° C. and a humidity of 65% for 3 days. One laminated film cut into a predetermined size from the vicinity of the part was prepared and used as a test piece. About this test piece, the dynamic friction coefficient in the outermost layer (A) was measured using the friction measuring machine based on ASTM-D1894 (Toyo Seiki Co., Ltd. make: TR type). It means that it is excellent in slipperiness, so that this value is small, and it can be determined that it is excellent in slipperiness if it is 0.35 or less, and it can be determined that it is especially excellent in it being 0.30 or less.

(2) Opening property: The cylindrical laminated films obtained in Examples and Comparative Examples were left in a roll-like room at a temperature of 23 ° C. and a humidity of 65% for 3 days. The length in the extrusion direction is cut to about 0.3 m in the vicinity of the part, and then the planar shape is punched to the dimensions shown in FIG. 1 so as not to peel off at the interface of the opposing innermost layer (B). A set of two test pieces in which the inner layers (B) are in contact with each other was prepared. A 'is the same size, shape, and position as A, and it is the part that is formed in the part facing A when cut from the cylindrical film. For simplicity, it is shown in the figure as A ′. With respect to this test piece, the A and A ′ portions of the test piece protruding in the extrusion direction shown in FIG. The load detected from the load cell when a set of two test pieces was peeled off was measured at a speed of 300 mm / min (unit: N). It means that it is excellent in opening property, so that this value is small, it can determine that it is excellent in opening property if it is 0.3 N or less, and it can be determined that it is especially excellent in it being 0.01 N or less.

(3) Transparency: Cylindrical laminated films obtained in Examples and Comparative Examples were cut to prepare a single laminated film having a predetermined size, which was used as a test piece. About this test piece, haze was measured using the fully automatic haze meter (Tokyo Denshoku Technical Center company make, model: TB-H3DPK) based on JISK7105 (unit:%). It means that it is excellent in transparency, so that this value is small, and it can be determined that it is excellent in transparency as it is 6.0% or less, and it can be determined that it is especially excellent in it being 5.0% or less.

(4) Hygiene: The cylindrical laminated films obtained in Examples and Comparative Examples were rewound by about 1.0 m, cut only in the direction perpendicular to the extrusion direction, and heat sealed with a width of 10 mm along the cut portion. The packaging bag was manufactured. This packaging bag was filled with 3 liters of a mixed solution of ethanol and pure water {mixing ratio: 90/10 (% by weight)}. After leaving in a room at a temperature of 23 ° C. and a humidity of 65% for 30 days, the mixture was evaporated and concentrated, and the evaporation residue in the packaging bag was precisely weighed (unit: mg). The smaller the weight of the evaporation residue, the better the hygiene, because the lubricant (crosslinked polymethyl methacrylate fine particles, erucic acid amide) does not elute or leave the mixed solution filled in the packaging bag. If it is less than 1.0 mg, it can be determined that the hygiene is excellent.

(5) Comprehensive evaluation: “◎”, all items judged to be excellent in all items and particularly excellent in two or more items, targeting the items described in (1) to (4) above. Those that were judged to be excellent were evaluated as “◯” and the others were evaluated as “×”.

[Production method]
<Example 1, Example 3, Comparative Examples 1 to 5, Comparative Example 7>
Weigh S-PBT for the outermost layer (A) and PMMA or talc as fine granular lubricant (C) in the proportions listed in Table 1 or Table 2, and evenly mix with a ribbon blender to obtain a dry blend. Obtained. The obtained dry blend was used with a twin-screw extruder (manufactured by Nippon Steel Works, model: TEX30HBT, screw configuration: stainless alloy), the discharge rate was 15 kB / hour, the screw rotation speed was 200 rpm, and the cylinder temperature was Pellets were obtained by melt-kneading under the conditions set at 270 ° C. Next, the above-mentioned pellets for the outermost layer (A), APO (1) pellets for the adhesive layer (1), and L-LDPE pellets for the innermost layer (B) were prepared. Three extruders (Ikegai Tekko Co., Ltd., screw diameter: 40 mmφ, L / D: 28) are connected to a water-cooled inflation molding machine (Sumitomo Heavy Industries Modern), and the above pellets are connected to the hopper of each extruder. The thickness of each layer is shown in Table 1 or Table 2 under the conditions of an extrusion resin temperature of 260 ° C., a water cooling temperature of 28 ° C., a winding speed of 10 m / min, and a cooling water amount of 15 liters / min. Then, a cylindrical three-layer laminated film having a folding diameter of 150 mm was produced, and the obtained laminated film was wound around a paper tube having a diameter of 3 inches. For the obtained cylindrical three-layer laminated film, the evaluation items were evaluated, and the obtained results are shown in Tables 1 and 2.

<Example 2>
In the example described in Example 1, a cylindrical three-layer lamination was performed in the same procedure as in Example 1, except that PA6 was used as the outermost layer (A) and APO (2) was used as the adhesive layer (1). A film was produced. The same evaluation was performed on these obtained cylindrical three-layer laminated films, and the obtained results are shown in Table 1.

<Examples 4 to 5 and Comparative Example 6>
Three types of pellets used in Example 1, PA6 pellets as an intermediate layer, and APO (2) pellets as an adhesive layer (2) were added to five units of the same type of extruder as in Example 1. Inserted into a hopper, connected 5 extruders to a water-cooled inflation molding machine (Sumitomo Heavy Industries Modern) equipped with a 5-type 5-layer annular die, and put the pellets into the hopper of each extruder, In the same procedure as in Example 1, a cylindrical five-layer laminated film was produced. The same evaluation was performed on these obtained cylindrical five-layer laminated films, and the obtained results are shown in Tables 1 and 2.

<Example 6>
In the example described in Example 4, a cylindrical five-layer laminated film was produced in the same procedure as in Example 4 except that zeolite was used as the fine granular lubricant (C). The same evaluation was performed on these obtained cylindrical five-layer laminated films, and the obtained results are shown in Table 1.

<Comparative Example 8>
In the example described in Example 1, a cylindrical three-layer laminated film was produced in the same procedure as in Example 1 except that EA, which is an organic compound lubricant, was used as the fine granular lubricant (C). The same evaluation was performed on these obtained cylindrical three-layer laminated films, and the results obtained are shown in Table 2.

<Comparative Example 9>
1500 ppm of EA was weighed with respect to L-LDPE, and these were uniformly mixed by a ribbon blender to obtain a dry blend. The obtained dry blend was used with a twin-screw extruder (manufactured by Nippon Steel Works, model: TEX30HBT, screw configuration: stainless alloy), the discharge rate was 15 kB / hour, the screw rotation speed was 200 rpm, and the cylinder temperature was Under the conditions set at 270 ° C., the mixture was melt-kneaded to obtain pellets. A cylindrical three-layer laminated film was produced in the same procedure as in Example 1 except that this pellet was used for the innermost layer (B). The obtained cylindrical three-layer laminated film was evaluated, and the obtained results are shown in Table 2.

From the above Tables 1 and 2, the following becomes clear.
(1) _A laminated film made of a thermoplastic resin, in which the blending amount of the fine granular lubricant (C) and {(d _(C) ) / (d _(A) )} satisfy the requirements specified in claim 1, It is excellent in any of slipperiness, opening property, transparency, and hygiene (see Examples 1 to 6).
(2) On the other hand, a laminated film made of a thermoplastic resin in which the fine granular lubricant (C) is not blended is inferior in slipperiness and openability, and thus is not suitable as a raw material for manufacturing packaging bags (comparison) See Example 1).
(3) Even when the fine granular lubricant (C) is blended, the laminated film made of a thermoplastic resin having a blending amount of less than 0.01% by weight is inferior in slipperiness and openability, so that it is used for manufacturing a packaging bag. Not suitable as a raw material (see Comparative Example 2)
(4) Even if the fine granular lubricant (C) is blended, the laminated film made of a thermoplastic resin having a blending amount exceeding 5.0% by weight is inferior in slipperiness and openability, so that it is a raw material for manufacturing packaging bags. Is not suitable (see Comparative Example 3).
(5) _A laminated film made of a thermoplastic resin having {(d _(C) ) / (d _(A) )} of less than 1 even if the fine granular lubricant (C) is blended in the range specified in claim 1 Is inferior in slipperiness, openability and the like, and is not suitable as a raw material for manufacturing packaging bags (see Comparative Examples 4 to 6).
(6) Even if the fine granular lubricant (C) is blended, the laminated film made of thermoplastic resin having {(d _(C) ) / (d _(A) )} exceeding 4 is remarkably inferior in hygiene. It is not suitable as a raw material for producing food packaging bags and medical packaging bags (see Comparative Example 7).
(7) Instead of the fine granular lubricant (C), since the openability is remarkably inferior even if a conventionally known organic compound lubricant (erucamide) is blended in the outermost layer (A), the packaging Not suitable as a raw material for bag production (see Comparative Example 8).
(8) Even if an organic compound lubricant (erucic acid amide) is blended in the innermost layer (B) instead of the fine granular lubricant (C), the slipperiness and openability are remarkably inferior. It is not suitable as a raw material for manufacturing packaging bags (see Comparative Example 9).

The laminated film made of a thermoplastic resin according to the present invention is suitable as a raw material for manufacturing a packaging bag because it is excellent in slipperiness, openability and the like. Further, the packaging bag made of the thermoplastic resin laminated film according to the second invention of the present invention is excellent in transparency and hygiene in addition to slipperiness and openability, and is therefore stored from the outside of the packaging bag. Since the presence or absence of an article can be easily confirmed and the components of the packaging bag do not dissolve in the article (particularly a liquid material) stored, it is suitable as a packaging bag for food or medical use.

It is a top view of the test piece used by the opening property evaluation test about the thermoplastic resin laminated film which concerns on this invention.

Explanation of symbols

A, A ': protrusions held by a chuck of a tensile tester

Claims (6)

It is a laminated film in which at least two layers of thermoplastic resins are laminated, and the blending amount of the fine granular lubricant (C) blended with the thermoplastic resin (A) constituting the outermost layer is 0.01-5. The ratio of the average particle diameter (d _(C) ) of the fine granular lubricant (C) to the thickness (d _(A) ) of the thermoplastic resin (A) constituting the outermost layer {(d _(C) ) / (d _(A) )} is 1.0 to 4.0, and is produced by an inflation method, and is a laminated film made of a thermoplastic resin. The laminated film made of a thermoplastic resin according to claim 1, wherein the fine particle lubricant (C) has an average particle diameter (d _(C) ) of 7 to 15 µm. The laminated film made of a thermoplastic resin according to claim 1 or 2, wherein the fine granular lubricant (C) is a crosslinked polymethyl methacrylate fine particle. The laminated film made of a thermoplastic resin according to any one of claims 1 to 3, wherein a sealant layer is provided in the innermost layer. The laminated film made of thermoplastic resin according to any one of claims 1 to 4, wherein the laminated film made of thermoplastic resin is produced by a water-cooled inflation method. A packaging bag manufactured using the thermoplastic resin laminated film according to any one of claims 1 to 5 as a raw material.

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