JP4618228B2 - Polyamide-based mixed resin laminated film roll and manufacturing method thereof - Google Patents

Description

  The present invention relates to a high-quality film roll having uniform physical properties over a long length obtained by winding a polyamide-based resin laminated film. Specifically, it is laminated with a polyolefin-based resin film for packaging retort foods and the like. The present invention relates to a polyamide-based resin laminated film roll having good processability when used.

  Nylon-based biaxially oriented polyamide resin film is tough and has excellent gas barrier properties, pinhole resistance, transparency, printability, etc., so it can be used for various liquid foods, water-containing foods, frozen foods, retort It has been widely put into practical use as a packaging material for various foods such as foods, pasty foods, livestock and fishery products, and in recent years, it has been widely used for packaging retort foods. Such a polyamide-based resin film is laminated with, for example, a polyolefin-based resin film such as polyethylene or polypropylene, folded in two parallel to the flow direction, then heat-sealed on three sides, and opened on one side. The three-side sealed bag is in a state, filled with various foods and the like, sealed, and then heat-sterilized in boiling water for market.

  However, when a biaxially oriented polyamide-based resin film is used, there is a phenomenon in which the corners of the packaging bag are warped after heat sterilization and the four sides curl into an S shape (hereinafter referred to as an S-curl phenomenon). It may occur and the appearance as a packaged product may be remarkably deteriorated. Therefore, as a method of reducing such curling phenomenon, as in Patent Document 1, the product of boiling water shrinkage strain rate and change rate of molecular orientation angle in the film width direction in a biaxially oriented polyamide resin film is adjusted to a specific value. In order to improve dimensional stability during boiling water treatment, it is necessary to extremely increase the temperature during heat setting or excessively perform relaxation heat treatment after stretching. Therefore, there arises a problem that the toughness and pinhole resistance of the obtained film are impaired.

  Therefore, as described in Patent Document 2, the applicants adjust the boiling water shrinkage and refractive index of the film to a specific numerical range, thereby reducing the S-curl phenomenon without reducing toughness and pinhole resistance. Invented and proposed a method for obtaining a biaxially oriented polyamide-based resin film that does not cause the problem.

Japanese Patent Laid-Open No. 4-103335 JP-A-8-174663

  According to the method of Patent Document 2 described above, it is possible to obtain a biaxially oriented polyamide-based resin film that is tough and excellent in pinhole resistance and does not cause an S-curl phenomenon. However, in the bag making process by lamination, the conditions such as pressure and time when heat-sealing are finely adjusted for each film roll used, so the boiling water shrinkage and refractive index of the film wound around the film roll Even in the case where the average value of physical property values such as is within the range of Patent Document 2, if the amount of fluctuation in one film roll is large, there is a wrinkle between the films when laminating in the bag making process. And troubles such as poor yield are likely to occur.

  On the other hand, in the manufacturing method of a biaxially stretched film roll for winding a biaxially stretched film after mixing and extruding a mixture of a plurality of resins, the applicants as raw material chips Proposed a method for reducing the segregation of the raw material by making the shape of the same and increasing the inclination angle of the funnel-like hopper which is a raw material supply unit to the extruder (Japanese Patent Laid-Open No. 2004-181777). However, this method is not necessarily a definitive method as a method for suppressing fluctuations and variations in physical properties such as boiling water shrinkage and refractive index of a film wound on a film roll.

  Therefore, as a result of earnestly examining the production technology for producing highly uniform biaxially stretched film rolls, the applicants have highly uniform physical properties such as film thickness, boiling water shrinkage rate and refractive index, The inventors have invented a polyamide-based resin film roll that can be formed with a high yield without causing wrinkles between the films when laminating (Japanese Patent Application No. 2004-262922).

  According to the polyamide resin film roll having highly uniform physical properties such as film thickness, boiling water shrinkage and refractive index as described above, the S-curl phenomenon is maintained without deteriorating the good toughness and pinhole resistance of the polyamide resin film. The processability at the time of laminating can be made good without causing the above. However, the polyamide-based resin film alone has a limit in gas barrier properties, and is not necessarily suitable for packaging applications such as fresh food products. In addition, as a means for improving the gas barrier property of the polyamide resin film, a method of blending with a highly crystalline resin or a method of laminating a layer of a highly crystalline resin is known. Or simply laminating results in variations in the concentration of the highly crystalline resin and the thickness of the highly crystalline resin layer, and the gas barrier properties are also non-uniform.

  In addition, a film made only of a polyamide-based resin has a limit in pinhole resistance, and is not necessarily suitable for food packaging applications containing a large amount of water such as liquid soup. Further, as a means for improving the pinhole resistance of a polyamide resin film, a method of filling an elastomer into a polyamide resin which is a film raw material is known. In such a mixed resin film roll, It is not possible to obtain good processability at the time of laminating simply by reducing the variation in physical properties such as thickness, boiling water shrinkage and refractive index, and there is variation in pinhole resistance in each laminated three-sided seal bag. It will occur.

  The present invention relates to a technology for laminating a layer made of a highly crystalline resin on a polyamide-based resin film in order to enhance gas barrier properties, and a production technology for making a mixed resin film mixed with an elastomer highly uniform. As a result of diligent research and development, it has been achieved, and its purpose is to eliminate the problems of conventional polyamide resin film rolls, to have extremely high gas barrier properties, high pinhole resistance and high transparency Biaxial orientation that can be used for packaging applications that require high performance, can be processed smoothly by laminating without any trouble, and can efficiently produce packages without S-curls The object is to provide a polyamide-based mixed resin laminated film roll. Another object of the present invention is to provide a biaxially oriented polyamide mixed resin film roll capable of obtaining a processed product with a high yield in post-processing such as bag making processing. In addition, it is providing the manufacturing method which can manufacture such a biaxially-oriented polyamide type mixed resin film roll efficiently.

Among the present inventions, the structure of the invention described in claim 1 includes a resin layer B containing polymetaxylylene adipamide in a content ratio of 90 to 100% by weight, and a resin layer mainly composed of a polyamide-based resin. A polyamide-based mixed-resin laminated film obtained by laminating A with an A / B / A configuration so that the width is 0.2 m to 3.0 m and the length is 300 m to 30000 m It is a mixed resin laminated film roll, and the sum of the thickness ratios of both surface layers A is 70 to 85%, which is to satisfy the following requirements (1) to (4).
(1) In the resin layer A mainly composed of the polyamide-based resin, a thermoplastic elastomer is added so as to have a mixing ratio of 0.5 wt% or more and less than 8.0 wt%, and the polymetaxylylene The first sample within 2 m from the end of winding of the film in which the thermoplastic elastomer is not added in the resin layer B mainly composed of adipamide or is added at a mixing ratio of less than 0.5% by weight When the cutout portion is provided, and the final cutout portion is provided within 2 m from the beginning of winding of the film, and the sample cutout portion is provided every 100 m ± 1 m from the first sample cutout portion,
(2) For each sample cut out from each cutout section, when measuring the maximum boiling water shrinkage rate, which is the maximum value among the boiling water shrinkage rates in all directions, an average that is the average value of the maximum boiling water shrinkage rates The boiling water shrinkage is 2% to 6%, and the variation rate of the maximum boiling water shrinkage of all the samples is within a range of ± 2% to ± 20% with respect to the average boiling water shrinkage (3) For each sample cut out from each cut-out part, the boiling water shrinkage direction difference, which is the absolute value of the difference between the boiling water shrinkage rate in the +45 degree direction with respect to the longitudinal direction and the boiling water shrinkage ratio in the −45 degree direction with respect to the longitudinal direction, is obtained. The average boiling water shrinkage direction difference, which is the average value of the boiling water shrinkage direction differences, is 3.0% or less, and the variation rate of the boiling water shrinkage direction difference of all the samples is the average boiling water shrinkage. Within ± 5% to ± 30% of the rate direction difference There (4) fluctuation index in the thickness over the entire length in the longitudinal direction of the wound roll is in the range of from ± 2% ~ ± 15% relative to the average thickness

The structure of the invention described in claim 2 is that, in the invention described in claim 1, the polyamide-based mixed resin laminated film satisfies the following formula (I).
Pa <1 / [t ( 0.015 x + 0.15)] (I)
(Where x is the content (% by weight) of polymetaxylylene adipamide in the film, Pa is the average oxygen permeability of the film at a temperature of 23 ° C. and a relative humidity of 65% (ml / m 2 · MPa · day), t Indicates the thickness (mm) of the film.)

The configuration of the invention described in claim 3 is that, in the invention described in claim 1 or 2 , when the oxygen permeability is obtained for each sample cut out from each of the cutout portions, the oxygen permeability is obtained. The average oxygen permeability which is an average value of the sample is 140 ml / m ² · MPa · day or less, and the variation rate of the oxygen permeability of all the samples is ± 2% to ± 20% with respect to the average oxygen permeability It is in the range of.

The structure of the invention described in claim 4 is that, in the invention described in claim 1 or 2 , each sample cut out from each cutout section satisfies the following requirement (5) and the following requirement (6). It is in.
(5) When measuring the three-dimensional surface roughness in the winding direction, the average surface roughness, which is the average value of the three-dimensional surface roughness, is in the range of 0.01 to 0.06 μm, and all The variation rate of the three-dimensional surface roughness of the sample is in the range of ± 5% to ± 20% with respect to the average surface roughness. (6) When haze is measured, the average value of those hazes A certain average haze is in the range of 2.0 to 7.0, and the haze variation rate of all the samples is in the range of ± 2% to ± 15% with respect to the average haze.

The structure of the invention described in claim 5 is the invention described in claim 1 or 2 , wherein the content of the thermoplastic elastomer component is measured for each sample cut out from each cut-out portion, and the contents thereof are included. When the average content rate, which is an average value of the rate, is calculated, the variation rate of the thermoplastic elastomer component content of all the samples is within a range of ± 10% with respect to the average content rate.

The structure of the invention described in claim 6 is the invention described in claim 1 or 2 , when the tensile elastic modulus in the winding direction of the film is measured for each sample cut out from each cut-out portion. The average tensile elastic modulus, which is the average value of the tensile elastic moduli, is 1.7 GPa or more and less than 3.1 GPa, and the variation rate of the tensile elastic modulus of all the samples is ± 10 with respect to the average tensile elastic modulus. It is in the range of%.

The structure of the invention described in claim 7 is the invention described in claim 1 or 2 , wherein each sample cut out from each cut-out portion is subjected to a gelbo flex tester in an atmosphere of 5 ° C. The number of pinholes in a case where a bending test of 500 cycles is continuously performed at a rate of 40 cycles per minute is that all are 10 or less.

The configuration of the invention described in claim 8 is that, in the invention described in claim 1 or 2 , when the refractive index in the thickness direction is measured for each sample cut out from each cut-out portion, the refractive index thereof is measured. The average refractive index, which is the average value, is 1.500 or more and 1.520 or less, and the variation rate of the refractive index of all the samples is within a range of ± 2% with respect to the average refractive index. .

The structure of the invention described in claim 9 is that, in the invention described in claim 1 or 2 , the main component of polyamide contained in the wound polyamide-based mixed resin laminated film is nylon 6.

The structure of the invention described in claim 10 is that, in the invention described in claim 1 or 2 , the wound polyamide-based mixed resin laminated film is laminated with a polyolefin resin film.

The structure of the invention described in claim 11 is the non-oriented obtained in the invention described in claim 1 or 2 by extruding the melted raw material resin from a T-die and bringing it into contact with a metal roll and cooling it. That is, a polyamide-based mixed resin laminated film obtained by biaxially stretching the sheet-like material is wound up.

The structure of the invention described in claim 12 is that in the invention described in claim 1 or 2 , the polyamide-based mixed resin laminated film stretched by the tenter stretching method is wound.

The structure of the invention described in claim 13 is that in the invention described in claim 1 or 2 , the polyamide-based mixed resin laminated film which has been successively biaxially stretched is wound.

The structure of the invention described in claim 14 is that in the invention described in claim 1 or 2 , the polyamide-based mixed resin laminated film stretched biaxially in the vertical direction and the horizontal direction is wound up. It is in.

The structure of the invention described in claim 15 is the invention described in claim 1 or 2 , wherein the sheet-like material made of substantially unoriented resin is heated at a temperature higher than the glass transition temperature of the resin + 20 ° C. A polyamide mixed resin laminate film that has been stretched in the longitudinal direction in at least two stages so as to have a magnification of 3 times or more, and then wound in the lateral direction so as to have a magnification of 3 times or more There is to be.

The structure of the invention described in claim 16 is that in the invention described in claim 1 or 2 , the polyamide-based mixed resin laminated film that has been heat-set after the final stretching treatment is wound. It is in.

The structure of the invention described in claim 17 is that in the invention described in claim 1 or 2 , the polyamide-based mixed resin laminated film which has been subjected to relaxation treatment after heat setting is wound.

The structure of the invention described in claim 18 is that, in the invention described in claim 1 or 2 , in the polyamide-based mixed resin laminated film wound up, a lubricant, an anti-blocking agent, a heat stabilizer, an antioxidant. In addition, at least one of an antistatic agent, a light resistance agent, and an impact resistance improving agent is added.

The structure of the invention described in claim 19 is that, in the invention described in claim 1 or 2 , inorganic particles are added to the wound polyamide-based mixed resin laminated film.

The structure of the invention described in claim 20 is that, in the invention described in claim 19 , the inorganic particles are silica particles having an average particle diameter of 0.5 to 5.0 μm.

The structure of the invention described in claim 21 is that, in the invention described in claim 1 or 2 , a higher fatty acid is added to the wound polyamide-based mixed resin laminated film.

According to a twenty- second aspect of the present invention, there is provided a manufacturing method for manufacturing the polyamide-based mixed resin laminated film roll according to the first or second aspect , wherein the raw material resin is obtained from a plurality of extruders by a coextrusion method. Film forming step of forming an unstretched laminated sheet in which a resin layer mainly composed of polymetaxylylene adipamide and a resin layer mainly composed of a polyamide-based resin are laminated by melting and extruding A biaxial stretching step of biaxially stretching the unstretched laminated sheet obtained in the forming step in the longitudinal direction and the transverse direction, and satisfying the following requirements (a) to (e).
(A) The film forming step forms a resin layer mainly composed of polyamide and a moisture content immediately before being supplied to a resin extruder for forming a resin layer mainly composed of polymetaxylylene adipamide. (B) The biaxial stretching step is stretched in two stages in the longitudinal direction and then in the transverse direction after the difference from the moisture content immediately before being supplied to the resin extruder is adjusted to 100 ppm or more. (C) the film-forming step is at least one of a plurality of extruders, wherein the first stage draw ratio in the two-stage stretching in the longitudinal direction is higher than the second stage draw ratio. From one or more, the resin chip with the largest amount used and one or more types of resin chips different from the resin chip are mixed and then melt extruded, and the shape of each resin chip used However, the resin chip other than the resin chip with the largest usage amount is an elliptic cylinder having an elliptical cross section with a major axis and a minor axis, and the average major axis, average minor axis and average of the resin chip with the largest usage amount The chip length is adjusted to have an average major axis, an average minor axis, and an average chip length that are included within a range of ± 20%, respectively. A step of melt-extruding using a plurality of extruders provided with a funnel-shaped hopper, and the inclination angles of the funnel-shaped hopper are all adjusted to 65 degrees or more, and are supplied to the funnel-shaped hopper The temperature of each previous resin chip is adjusted to 80 ° C. or higher. (E) The film forming step winds the molten resin that has been melt-extruded in a laminated state onto a cooling roll. In this cooling process, the portion of the molten resin that contacts the surface of the cooling roll is sucked by the suction device in the direction opposite to the winding direction over the entire width of the molten resin. That

The structure of the invention described in claim 23 is the invention described in claim 22 , including a preheating step performed before the longitudinal stretching step and a heat treatment step performed after the longitudinal stretching step. The fluctuation range of the surface temperature of the film at an arbitrary point in the longitudinal stretching step, the preheating step, and the heat treatment step is adjusted within the range of the average temperature ± 1 ° C. over the entire length of the film. .

  According to the polyamide-based mixed resin laminated film roll of the present invention, a three-side sealed bag for packaging fresh food products that require high gas barrier properties, and food products that require good pinhole resistance and high transparency. It is possible to easily form a three-side seal bag for wrapping etc. Further, when forming these three-side sealed bags, the bag making process by lamination can be performed smoothly with almost no trouble, and it becomes possible to efficiently obtain a package without S-curls. Further, in post-processing such as bag making processing, a processed product can be obtained with a high yield. In addition, if the polyamide-based mixed resin laminated film roll of the present invention is used, the bag for food packaging after the bag-making process by lamination will have a very high gas barrier property and good pinhole resistance Further, not only high transparency is exhibited, but also variations in gas barrier properties, pinhole resistance and transparency of each bag are reduced.

  Further, according to the method for producing a polyamide-based mixed resin laminated film roll of the present invention, as described above, a three-side sealed bag having a very high gas barrier property, good pinhole resistance, and high transparency. In addition to being able to be formed, it is possible to obtain a polyamide-based mixed resin film roll having good laminate processability at low cost and very efficiently.

  When the sample of the polyamide-based mixed resin film roll of the present invention is cut out by the method described later, when the maximum boiling water shrinkage rate, which is the maximum value of the boiling water shrinkage rate in all directions, is measured for all samples, The average boiling water shrinkage, which is the average value of the maximum boiling water shrinkage, is adjusted to be 2% or more and 6% or less.

  Moreover, when the polyamide-based mixed resin film roll of the present invention is cut out by the method described later, the boiling water shrinkage rate in the +45 degree direction with respect to the longitudinal direction and the −45 degree direction with respect to the longitudinal direction are obtained for all the samples. When the difference in boiling water shrinkage direction, which is the absolute value of the difference from the boiling water shrinkage, is determined, the average boiling water shrinkage direction difference, which is the average value of these boiling water shrinkage direction differences, is 3.0% or less. It has been adjusted.

  In the cutting of the sample in the present invention, first, the first sample cutting portion is provided within 2 m from the end of winding of the film, and the final cutting portion is provided within 2 m from the beginning of winding of the film. A sample cut-out section is provided every about 100 m. Note that “about every 100 m” means that the sample may be cut out at about 100 m ± 1 m.

The cutting of the sample will be described more specifically. For example, when a polyamide-based mixed resin laminated film having a length of 498 m is wound around a roll, the first sample (within 2 m from the end of winding of the film) Cut out 1). In addition, for cutting out the sample,
The film is cut into a rectangular shape (not cut obliquely) so as to have a side along the longitudinal direction of the film and a side along the direction orthogonal to the longitudinal direction. Subsequently, the second sample (2) is cut away from the cut portion at a distance of 100 m from the winding start side. Similarly, 200
The third sample (3) away from the winding start side of m, the fourth sample (4) away from the winding start side of 300 m, and the fifth sample (5) away from the winding start side of 400 m. cut out. When the sample is cut out in this way, the remainder becomes shorter than 100 m, so the sixth (final) sample (6) cuts out any portion within 2 m from the start of film winding.

  For each of the cut samples, the boiling water shrinkage rate (hereinafter referred to as BS), the maximum boiling water shrinkage rate (hereinafter referred to as BSx), the average boiling water shrinkage rate (hereinafter referred to as BSax), and the boiling water shrinkage direction in the following manner. A difference (hereinafter referred to as BSd) and an average boiling water shrinkage direction difference (hereinafter referred to as BSad) are measured.

[Measuring method of boiling water shrinkage (BS), maximum boiling water shrinkage (BSx), average boiling water shrinkage (BSax), boiling water shrinkage direction difference (BSd), average boiling water shrinkage direction difference (BSad)]
The film cut out from each cut-out portion of the polyamide-based mixed resin laminated film roll is cut into a square shape and left in an atmosphere of 23 ° C. and 65% RH for 2 hours or more. A circle (about 20 cm in diameter) centered on the center of this sample is drawn, and a straight line passing through the center of the circle in the direction of 0 to 165 ° clockwise at 15 ° intervals, with the vertical direction (film drawing direction) being 0 °. Pull, measure the diameter in each direction, and make it the length before processing. The cut sample was then heat-treated in boiling water for 30 minutes, then removed and wiped off the moisture adhering to the surface, air-dried, and left in an atmosphere of 23 ° C. and 65% RH for 2 hours or more, as described above. The length of the straight line drawn in each diametric direction is measured and set as the length after treatment. BS (boiling water shrinkage), BSx (maximum boiling water shrinkage), BSax (average boiling water shrinkage), BSd (boiling water shrinkage direction difference) and BSad (average boiling water shrinkage direction difference) are calculated.
BS = [(length before processing−length after processing) / length before processing] × 100 (%)... 1
BSx = Maximum shrinkage rate (%) measured in 0 to 165 ° direction at 15 ° intervals 2
BSax = sum of BSx of all samples / number of samples 3
BSd = | (BS in 45 ° direction) − (BS in 135 ° direction) |
BSad = sum of BSd of all samples / number of samples 5

  The BSx value of the film constituting the polyamide-based mixed resin laminated film roll ensures heat resistance (also referred to as laminate strength or heat-resistant laminate strength) when the film is formed into a bag shape and subjected to hot water treatment. It is important to improve the toughness and pinhole resistance of the film itself. If the BSx value is less than 2%, the toughness and pinhole resistance will be insufficient. Or the heat-resistant laminate strength at the time of hot water treatment becomes insufficient. The range of BSx that is more preferable for enhancing toughness, pinhole resistance, laminating properties, and heat-resistant laminating strength is 3.5 to 5.0%.

  In addition, the BSd value of the film constituting the polyamide-based mixed resin laminated film roll has a great influence on the curling phenomenon that occurs during the boiling water treatment, and the larger the BSd value, the more easily the bag is bent and the curling becomes remarkable. If BSd is suppressed to 3.0% or less, preferably 2.0% or less, more preferably 1.5% or less, bag warping during boiling water treatment is suppressed as much as possible, and the occurrence of S-curl phenomenon occurs. Can be prevented.

  Further, in the polyamide-based mixed resin laminated film roll of the present invention, the variation rate of the maximum boiling water shrinkage (BSx) of all the cut out samples is ± 2% to ± 20% (± 2) of the average boiling water shrinkage (BSa). % Or more and ± 20% or less) is required to be adjusted. Here, the variation rate of the maximum boiling water shrinkage (BSx) of all the samples is the maximum / minimum of the maximum boiling water shrinkage (BSx) of all the samples, and the average boiling water shrinkage of those maximum / minimum. It means the ratio of the difference with respect to the average boiling water shrinkage when the difference between the one with the larger difference between the ratio and the average boiling water shrinkage is obtained.

  That is, in the polyamide-based mixed resin laminated film of the present invention, when the boiling water shrinkage rate of the samples (1) to (6) is Xn (n = 1 to 6), the maximum value Xmax of Xn and the average boiling water shrinkage rate. This means that both the difference from (BSax) and the difference between the minimum value Xmin and the average boiling water shrinkage (BSax) must be within ± 20%, in other words, | BSax -Xn | (where || represents an absolute value) must be 20% or less.

  In the polyamide-based mixed resin laminated film roll of the present invention, it is preferable that the variation rate of the maximum boiling water shrinkage (BSx) of all the cut out samples is within ± 15% of the average boiling water shrinkage (BSa). , More preferably within a range of ± 10%, and even more preferably within a range of ± 8%.

  In addition, the polyamide-based mixed resin laminated film roll of the present invention is preferably as small as the variation rate of the maximum boiling water shrinkage (BSx) of all cut out samples, but the lower limit of the variation rate is 2 in consideration of measurement accuracy. % Is considered the limit.

  Further, in the polyamide based mixed resin laminated film roll of the present invention, the fluctuation rate of the boiling water shrinkage direction difference (BSd) of all the cut out samples is ± 2% to ± 30% of the average boiling water shrinkage direction difference (BSad). It is necessary to adjust to be within the range of (± 2% or more and ± 30% or less). Here, the fluctuation rate of the boiling water shrinkage direction difference (BSd) of all the samples is the maximum / minimum in the boiling water shrinkage direction difference (BSd) of all the samples, and the average of these maximum / minimum values. When the difference between the larger difference between the boiling water shrinkage direction difference and the average boiling water shrinkage direction difference is obtained, it means the ratio of the difference to the average boiling water shrinkage direction difference.

  That is, in the polyamide-based mixed resin laminated film of the present invention, when the boiling water shrinkage direction difference of the samples (1) to (6) is Yn (n = 1 to 6), the maximum value Ymax of Yn and the average boiling water The difference between the shrinkage rate direction difference (BSad) and the difference between the minimum value Ymin and the average boiling water shrinkage direction difference (BSad) must be within ± 30%. In other words, | BSad-Yn | (where || indicates an absolute value) must be 30% or less.

  In the polyamide-based mixed resin laminated film roll of the present invention, the fluctuation rate of the boiling water shrinkage direction difference (BSd) of all the cut out samples is within ± 25% of the average boiling water shrinkage direction difference (BSad). More preferably within a range of ± 23%, even more preferably within a range of ± 21%, even more preferably within a range of ± 17%, and particularly preferably within a range of ± 15%. preferable.

  In addition, the polyamide-based mixed resin laminated film roll of the present invention is preferable as the fluctuation rate of the boiling water shrinkage direction difference (BSd) of all the cut out samples is smaller, but the film raw material is MXD-6, thermoplastic elastomer, polyamide It is a mixed resin composed of a resin and the like, and considering the physical properties of a thermoplastic elastomer or the like, the lower limit of the fluctuation rate is considered to be about 5%. When only the measurement accuracy is taken into consideration, the lower limit of the fluctuation rate of the boiling water shrinkage direction difference is considered to be about 2%.

  In the polyamide-based mixed resin laminated film roll of the present invention, the variation rate of the thickness over the entire length in the longitudinal direction is within a range of ± 2% to ± 15% (± 2% to ± 15%) with respect to the average thickness. It is necessary to be adjusted so that Here, the variation rate of the thickness over the entire length in the longitudinal direction is the maximum / minimum of the thickness over the entire length in the longitudinal direction, and the difference between the average thickness of the maximum / minimum average thickness and the average thickness It means the ratio of the difference to the average thickness when the difference is obtained.

  That is, in the polyamide based mixed resin laminated film of the present invention, the difference between the maximum value Tmax of the thickness over the entire length in the longitudinal direction and the average thickness (the average thickness Ta over the entire length in the longitudinal direction), the minimum value Tmin and the average thickness (Ta ) Is required to be within ± 15%.

  In the polyamide-based mixed resin laminated film roll of the present invention, the variation rate of thickness over the entire length in the longitudinal direction is preferably within ± 10% of the average thickness (Ta), and is within ± 8%. And more preferred.

  In addition, the polyamide-based mixed resin laminated film roll of the present invention is preferably as small as the variation rate of the thickness over the entire length in the longitudinal direction, but the lower limit of the variation rate is limited to about 2% from the performance of the film forming apparatus. I think there is.

Moreover, when the sample of the polyamide-based mixed resin laminated film roll of the present invention is cut out by the same method as described above, when the oxygen permeability is determined for each sample cut out from each cut-out part, preferably the average oxygen permeability is the average value of the oxygen permeability is not more than ^{140ml / m 2 · MPa · day} , more preferably it is not more than ^{120ml / m 2 · MPa · day} , 100ml / m 2 · MPa · It is particularly preferable that it is not more than day.

  Further, the polyamide mixed resin laminated film roll of the present invention has a variation rate of oxygen permeability within a range of ± 2% to ± 20% (± 2% to ± 20%) with respect to the average oxygen permeability. It is preferable that the adjustment is performed. Here, the fluctuation rate of oxygen permeability is the maximum / minimum of oxygen permeability, and the difference between the average oxygen permeability and the larger of the maximum / minimum average oxygen permeability It means the ratio of the difference in the average oxygen permeability when obtained.

  That is, in the polyamide-based mixed resin laminated film roll, the difference between the maximum oxygen permeability Pmax and the average oxygen permeability Pa and the difference between the minimum Pmin and the average oxygen permeability Pa are both ± 20%. It is necessary to be within.

  The polyamide-based mixed resin laminated film roll of the present invention preferably has a variation rate of oxygen permeability within ± 15% of the average oxygen permeability (Pa), and within ± 10%. More preferred.

  In addition, the polyamide-based mixed resin laminated film roll of the present invention is preferably as the fluctuation rate of the oxygen permeability is small, but the lower limit of the fluctuation rate is considered to be about 2% from the viewpoint of the performance of the film forming apparatus. ing.

  Moreover, as for the polyamide-type mixed resin laminated | multilayer film roll of this invention, the average surface roughness (SRaa) which is the average value of the three-dimensional surface roughness (SRa) of all the cut-out samples is the range of 0.01-0.06 micrometer. And preferably in the range of 0.02 to 0.05 μm (an example of a method for measuring the three-dimensional surface roughness will be described in Examples). If the average surface roughness is less than 0.01 μm, good slipperiness under high humidity cannot be obtained, and on the contrary, if the average surface roughness is more than 0.06 μm, when laminating, Since adhesiveness with films, such as polyolefin, will fall, it is not preferred.

  Further, in the polyamide-based mixed resin laminated film roll of the present invention, the variation rate of the three-dimensional surface roughness (SRa) of all the cut-out samples is ± 5% to ± 20% of the average surface roughness (SRaa) (± It is preferable to adjust to be within a range of 5% or more and ± 20% or less. Here, the variation rate of the three-dimensional surface roughness (SRa) of all samples is the maximum / minimum of the three-dimensional surface roughness (SRa) of all samples, and the average of the maximum / minimum values. It means the ratio of the difference to the average surface roughness when the difference between the larger surface roughness and the average surface roughness is obtained.

  That is, in the polyamide-based mixed resin laminated film roll of the present invention, when the three-dimensional surface roughness of the samples (1) to (6) is SRn (n = 1 to 6), the SRn maximum value SRmax is In other words, the difference between the average surface roughness (SRaa) and the difference between the minimum value SRmin and the average surface roughness are preferably within ± 20%. In other words, | SRaa−SRn | (Where || represents an absolute value) is preferably 20% or less.

  In the polyamide-based mixed resin laminated film roll of the present invention, the variation rate of the three-dimensional surface roughness (SRa) of all cut out samples is within a range of ± 15% of the average surface roughness (SRaa). More preferably, it is more preferably within the range of ± 10%, and particularly preferably within the range of ± 8%. In addition, the polyamide-based mixed resin laminated film roll of the present invention is preferable as the variation rate of the three-dimensional surface roughness (SRa) of all the cut out samples is smaller, but the lower limit of the variation rate is based on measurement accuracy. We think about 5% is the limit.

Also, polyamide-based mixed resin laminated film roll of the present invention, preferably the average haze which is the average value of haze of all samples cut out is in the range of 2.0% to 7.0%, 2.0% ~ More preferably, it is in the range of 5.0 % . When the average haze is more than 5.0 % , the bag formed is deteriorated in appearance when it is subjected to bag making, and is not suitable as a bag requiring high transparency. Although the average haze is preferably as small as possible, the lower limit of the average haze is considered to be about 2.0 % when considering the transparency and measurement accuracy of MXD-6 and thermoplastic elastomer forming the core layer. ing.

  Further, in the polyamide-based mixed resin laminated film roll of the present invention, the haze fluctuation rate of all cut out samples is within the range of ± 2% to ± 15% (± 2% or more and ± 15% or less) of the average haze. It is preferable to adjust so as to be. Here, the haze variation rate of all samples is the maximum / minimum of all samples in the haze, and the difference between the average haze and the larger of the maximum / minimum average hazes It refers to the ratio of the difference to the average haze when obtained.

  That is, in the polyamide-based mixed resin laminated film of the present invention, when the haze of the samples (1) to (6) is Hn (n = 1 to 6), the difference between the maximum value Hmax of Hn and the average haze. And the difference between the minimum value Hmin and the average haze (Han) is preferably within ± 15%. In other words, | Han−Hn | (where || is an absolute value) Are preferably 15% or less.

  In the polyamide-based mixed resin laminated film roll of the present invention, the haze variation rate of all cut out samples is preferably within ± 10% of the average haze, and more preferably within ± 8%. preferable. In addition, the polyamide-based mixed resin laminated film roll of the present invention is preferably as the haze variation rate of all cut out samples is smaller, but the lower limit of the variation rate is about 2% in consideration of measurement accuracy. I believe.

  Moreover, the polyamide-based mixed resin laminated film roll of the present invention quantitatively analyzes the content of the thermoplastic elastomer component for each sample cut as described above, and calculates the average content that is the average value of those contents Then, it is preferable that the variation rate of the content of the thermoplastic elastomer component of all the samples is within a range of ± 10% with respect to the average content rate.

  Here, the variation rate of the thermoplastic elastomer component content of all the samples is the maximum / minimum of the thermoplastic elastomer component content (measured value) of all the samples. It means the ratio of the difference with respect to the average content when the difference between the average content and the one with the larger difference from the average content is obtained. As will be described later, the content of the thermoplastic elastomer component is sliced perpendicular to the surface to form an ultrathin piece, and the elastomer component is dyed with a specific substance to occupy the entire dyed portion. It can be measured by a method of calculating the area ratio, or can be measured by other methods such as infrared analysis and NMR analysis focusing on a peak peculiar to the elastomer.

  In the polyamide-based mixed resin laminated film roll of the present invention, the variation rate of the elastomer component content of all cut out samples is more preferably within ± 9% of the average content, and within ± 8% Is more preferably in the range of ± 7%, particularly preferably in the range of ± 7%.

  In addition, the polyamide-based mixed resin laminated film roll of the present invention is preferably as small as the variation rate of the elastomer component content of all cut out samples, but the lower limit of the variation rate is about 2% in consideration of measurement accuracy. Is the limit.

Moreover, the polyamide-based mixed resin film roll of the present invention has an average tensile elastic modulus of 1. as the average value of the tensile elastic modulus when the tensile elastic modulus is measured for each sample cut out from each cut-out portion. 7GPa with less than (1700N / mm ²⁾ or more 3.1GPa (3100N / mm ^2), tensile modulus change rate of all samples, adjusted within a range of ± 10% relative to the average tensile elastic modulus Preferably. Here, the fluctuation rate of the tensile modulus of elasticity of all the samples is the maximum / minimum of the tensile modulus of elasticity of all the samples, and the larger of the difference between the average tensile modulus of the maximum / minimum It means the ratio of the difference to the average tensile elastic modulus when the difference from the average tensile elastic modulus is obtained.

  In addition, the tensile elastic modulus of the polyamide-based mixed resin film constituting the polyamide-based mixed resin film roll is important in increasing the toughness and pinhole resistance of the film itself. When the tensile elastic modulus is less than 1.7 GPa, When forming a bag that requires both transparency and pinhole resistance at the same time, the toughness and pinhole resistance are insufficient. This is not preferable because the tearability deteriorates. A more preferable range of tensile elastic modulus is 1.9 GPa to 2.9 GPa for enhancing toughness / pinhole resistance and tearability when forming a three-side seal bag.

  In the polyamide-based mixed resin film roll of the present invention, the variation rate of the tensile modulus of all cut out samples is preferably within ± 9% of the average tensile modulus, and within ± 8%. More preferably, it is more preferably within a range of ± 7%.

  In addition, the polyamide-based mixed resin film roll of the present invention is preferably as small as the variation rate of the tensile modulus of all the cut out samples, but the lower limit of the variation rate is limited to about ± 2% in consideration of measurement accuracy. I believe that.

  In addition, the polyamide-based mixed resin film roll of the present invention is 40 cycles per minute using a gelbo flex tester for each sample cut out from each cut-out portion in an atmosphere of about 5 ° C. in the following manner. It is preferable that the number of pinholes when the bending test of 500 cycles is continuously performed at a speed of 5 is adjusted to be 10 or less.

[Measurement method of pinhole resistance]
A film laminated with a polyolefin film or the like and cut to a predetermined size (20.3 cm × 27.9 cm) is conditioned at a predetermined temperature for a predetermined time, and then the rectangular test film is wound. A cylindrical shape of a predetermined length is used. Then, both ends of the cylindrical film are fixed to the outer periphery of the disk-shaped fixed head of the gel bow flex tester and the outer periphery of the disk-shaped movable head, respectively, and the movable heads are parallel to the direction of the fixed head. Rotate a predetermined angle (440 °) while approaching a predetermined length (7.6 cm) along the axis, and then proceed straight ahead for a predetermined length (6.4 cm) without rotating, then reverse their movements A one-cycle bending test in which the movable head is returned to the initial position by being executed in the direction is continuously repeated for a predetermined cycle (500 cycles) at a predetermined speed (40 cycles per minute). Thereafter, the number of pinholes generated in a predetermined range (497 cm ² ) excluding a fixed portion of the tested film and a portion fixed to the outer periphery of the movable head is measured.

Furthermore, when the polyamide-based mixed resin laminated film roll of the present invention is cut out by the above method, when the refractive index (Nz) in the thickness direction is obtained for all the samples, the average value of the refractive indexes is obtained. The average refractive index (Nza) is preferably adjusted to be 1.500 or more and 1.520 or less. The average refractive index is calculated by the following formula 6.
Nza = total Nz of all samples / number of samples 6

  In addition, the value of Nz of the film which comprises a polyamide-type mixed resin laminated | multilayer film roll has big influence on film quality, such as laminate strength and thickness spots. Therefore, the requirement that the average refractive index is 1.500 or more and 1.520 or less is an essential requirement when the biaxially oriented film is laminated with a polyolefin resin film. When Nz is less than 1.500, the laminate strength with the polyolefin resin film or the like becomes insufficient, and peeling between the laminate base material is likely to occur due to boiling water treatment after bag making. On the other hand, this Nz gradually decreases in the process of biaxially stretching an unstretched film. In other words, Nz can also be considered as one of the indices of stretching, and a large Nz indicates that stretching is insufficient. If Nz exceeds 1.520, it is due to insufficient biaxial stretching. Thick spots and the like appear remarkably, and satisfactory film quality cannot be obtained. Considering both the laminate strength and the film quality, a particularly preferable range of Nz is in the range of 1.507 to 1.516.

  Further, in the polyamide-based mixed resin laminated film roll of the present invention, the variation rate of the refractive index (Nz) of all the cut out samples is ± 2 with respect to the average value of the refractive indexes (hereinafter referred to as the average refractive index). It is preferable to adjust so that it may become in the range within%. Here, the variation rate of the refractive index (Nz) of all the samples is the maximum / minimum of the refractive indexes (Nz) of all the samples, and the difference between the average refractive index of the maximum / minimum values. When the difference between the larger one and the average refractive index is obtained, it means the ratio of the difference to the average refractive index.

  That is, in the polyamide-based mixed resin laminated film roll of the present invention, when the refractive indexes of the samples (1) to (6) are Nz1 to Nz6, the difference between the maximum value Nzmax of Nz1 to Nz6 and the average refractive index , Nz1 to Nz6, and the difference between the minimum value Nzmin and the average refractive index is preferably within ± 2%, in other words, | average refractive index−Nz1 | ˜ | average refractive index. -Nz6 | is preferably 2% or less. In the polyamide-based mixed resin laminated film roll of the present invention, it is more preferable that the variation rate of the refractive index (Nz) of all the cut out samples is within a range of ± 1% with respect to the average refractive index.

  In addition, the polyamide-based mixed resin laminated film roll of the present invention is preferable as the variation rate of the refractive index (Nz) of all the cut out samples is smaller. However, the lower limit of the variation rate is from the viewpoint of measurement accuracy and mechanical accuracy. About 0.1% is considered the limit.

  As described above, the maximum boiling water shrinkage rate in a single polyamide-based mixed resin laminated film roll is adjusted to a predetermined range of values such as the maximum boiling water shrinkage rate, the difference in boiling water shrinkage direction, and the thickness variation in the longitudinal direction. In addition, by reducing fluctuations in boiling water shrinkage direction difference, longitudinal thickness unevenness, etc., it is possible to prevent deterioration of the appearance in bag making and laminating, and it is possible to process smoothly with high yield. The variation in gas barrier properties for each processed bag is reduced.

  Examples of the polyamide resin used in the present invention include nylon 6 using ε-caprolactam as a main raw material. Examples of other polyamide resins include polyamide resins obtained by polycondensation of lactams having three or more members, ω-amino acids, dibasic acids and diamines. Specifically, as lactams, in addition to the aforementioned ε-caprolactam, enantolactam, capryllactam, lauryllactam, and ω-amino acids include 6-aminocaproic acid, 7-aminoheptanoic acid, 9- Examples include aminononanoic acid and 11-aminoundecanoic acid. Dibasic acids include adipic acid, glutaric acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, undecanedioic acid, dodecadioic acid, hexadecadioic acid, eicosandioic acid, eicosadienedioic acid, 2 2,4-trimethyladipic acid, terephthalic acid, isophthalic acid, 2,6-naphthalenedicarboxylic acid, and xylylenedicarboxylic acid. Furthermore, as diamines, ethylenediamine, trimethylenediamine, tetramethylenediamine, hexamethylenediamine, pentamethylenediamine, undecamethylenediamine, 2,2,4 (or 2,4,4) -trimethylhexamethylenediamine, cyclohexane Examples thereof include diamine, bis- (4,4′-aminocyclohexyl) methane, and metaxylylenediamine. And polymers obtained by polycondensation of these or copolymers thereof, such as nylon 6, 7, 11, 12, 6.6, 6.9, 6.11, 6.12, 6T, 6I, MXD6 (Metaxylene dipanamid 6), 6 / 6.6, 6/12, 6 / 6T, 6 / 6I, 6 / MXD6, and the like can be used. In addition, when the polyamide film roll of the present invention is produced, the above polyamide resins can be used alone or in admixture of two or more.

  Of the polyamide-based resins, those having a relative viscosity in the range of 2.0 to 3.5 are particularly preferable in the present invention. The relative viscosity of the polyamide-based resin affects the toughness and spreadability of the resulting biaxially stretched film. If the relative viscosity is less than 2.0, the impact strength tends to be insufficient. This is because, if it exceeds 3.5, the biaxial stretchability tends to deteriorate with increasing stretching stress. In addition, the relative viscosity in this invention means the value at the time of measuring at 25 degreeC using the solution which melt | dissolved 0.5g of polymers in 50 ml of 97.5% sulfuric acid.

  Examples of the thermoplastic elastomer used in the present invention include a polyamide such as a block or random copolymer of a polyamide-based resin such as nylon 6 or nylon 12 and PTMG (polytetramethylene glycol) or PEG (polyethylene glycol). -Based elastomers, ethylene-acrylic acid copolymers, ethylene-methacrylic acid copolymers, copolymers of ethylene and butene, polyolefin elastomers such as copolymers of styrene and butadiene, and olefin resins such as ethylene ionomers These ionomers can be suitably used. In the case where the polyamide resin constituting the outer layer is mainly nylon 6, the thermoplastic elastomer to be included is that the nylon 6-based elastomer is used rather than the nylon 12-based elastomer as the film constituting the film roll. The impact resistance and laminate adhesion are improved, which is preferable. The cause of this is not clear, but it is believed that the combination of the number of methylene groups of the polyamide resin and the number of methylene groups of the thermoplastic elastomer results from the improvement of the fine dispersibility of the thermoplastic elastomer.

  The polyamide-based mixed resin laminated film roll of the present invention comprises a plurality of resin layers by melt-extruding MXD-6 chips, polyamide resin chips, and thermoplastic elastomer chips, which are raw materials, using a coextrusion method described later. A non-stretched laminated sheet (unstretched laminated film) is formed, and the unstretched laminated film (unstretched laminated sheet) is biaxially stretched in the longitudinal direction (longitudinal direction) and in the transverse direction (width direction) before being rolled. Manufactured by winding on.

  The polyamide-based mixed resin laminated film may have a configuration of A / B (two types and two layers), A / B / A (two types and three layers), or A / B / C (three types and three layers). is necessary. From the viewpoint of curling, an A / B / A configuration that is a symmetrical layer configuration is preferable. In the following description, among the layers constituting the laminated film, the central layer not located on the outermost side (that is, the B layer in the case of the A / B / A or A / B / C layer configuration) A thin layer in the case of the two-type two-layer configuration (that is, the B layer in the case of the A / B layer configuration of the thick A layer and the thin B layer) is referred to as a core layer. Further, the outermost layer (that is, the A and C layers in the case of the A / B / A or A / B / C layer configuration) and the thick layer in the case of the two-type two-layer configuration (that is, thick) The A layer in the case of the A / B layer structure of the A layer and the thin B layer is referred to as a skin layer.

  The thickness ratio of each layer of the polyamide-based mixed resin laminated film is preferably 50 to 95% for the A layer or the A layer and the C layer, more preferably 60 to 90%, and particularly preferably 70 to 85%. It is. The thickness ratio of the B layer is preferably 5 to 50%, more preferably 10 to 40%, and particularly preferably 15 to 30%. In the case of the A / B / A configuration of two types and three layers, the thickness ratio of the A layer of the surface layer means the sum of the thickness ratios of both surface layers, and in the case of the A / B / C configuration of the three types and three layers, the surface layer The thickness ratio of the A layer and the C layer means the sum of the thickness ratios of both surface layers. If the thickness ratio of the A layer or the A layer and the C layer is less than 50%, the bending fatigue resistance deteriorates and pinholes increase, which is not preferable. On the other hand, if the thickness ratio of the A layer or the A layer and the C layer exceeds 95%, the gas barrier property is insufficient, which is not preferable.

  In order to produce the laminated film as described above, in forming a substantially unoriented resin sheet having a layer structure of A / B, A / B / A, or A / B / C, each layer A method for obtaining a substantially unoriented resin sheet by melting and co-extruding the polymer constituting the resin using a separate extruder, casting on a rotating drum from a die, and solidifying by quenching (so-called co-extrusion method) ) Can be suitably employed.

  Moreover, as resin which forms a skin layer, it is necessary to contain at least polyamide-type resin and a thermoplastic elastomer, and MXD6 can be mixed as needed. The amount of the thermoplastic elastomer added to the polyamide resin needs to be 0.5 wt% or more and less than 8.0 wt%, and the lower limit of the addition amount is preferably 1.0 wt% or more. 3.0 wt% or more is more preferable. On the other hand, the upper limit of the addition amount is preferably 6.0% by weight or less, and more preferably 5.0% by weight or less. If the added amount of the thermoplastic elastomer is less than 0.5% by weight, good pinhole resistance at room temperature cannot be obtained, which is not preferable. On the contrary, the added amount of the thermoplastic elastomer is 8.0% by weight or more. Then, it becomes unsuitable for packaging applications such as foods that require high transparency (haze), and when it is laminated with another film, the adhesiveness becomes insufficient. Furthermore, the resin forming the skin layer can be filled with a resin other than MXD-6, a thermoplastic elastomer, and a polyamide resin, if necessary, and can be filled with a lubricant, an anti-blocking agent, and a heat stabilizer. It is also possible to fill with an antioxidant, an antistatic agent, a light resistant agent, an impact resistance improving agent and the like.

  On the other hand, the resin forming the core layer needs to contain at least MXD6, and other resins such as a polyamide-based resin and a thermoplastic elastomer can be mixed as necessary. In addition, when mixing resin other than MXD6 in resin which forms a core layer, it is preferable that the content rate of MXD6 shall be 90 to 100 weight%. In addition, the resin forming the core layer can be filled with a lubricant, an anti-blocking agent, a heat stabilizer, an antioxidant, an antistatic agent, a light-proofing agent, an impact resistance improving agent, etc., if necessary. It is. Thus, by providing a skin layer mainly composed of a relatively soft polyamide-based resin outside the core layer mainly composed of hard MXD-6, and filling the skin layer with a thermoplastic elastomer. It is possible to exhibit good gas barrier properties due to MXD-6 and at the same time to exhibit good pinhole resistance due to the thermoplastic elastomer and polyamide resin.

  The resin for forming the core layer and the resin for forming the skin layer are interchanged, the skin layer is formed with a resin containing at least MXD6, and the core layer is formed with a resin containing at least a polyamide-based resin and a thermoplastic elastomer. It is also possible. In such a case, the thickness ratio of each layer of the polyamide-based mixed resin laminated film is preferably 5 to 50% of the A layer, or the A layer and the C layer, and more preferably 10 to 40%. Especially preferably, it is 15 to 30%. Even in such a case, in the case of a two-type / three-layer A / B / A configuration, the thickness ratio of the A layer of the surface layer means the sum of the thickness ratios of both surface layers, and the A / B / In the case of the C configuration, the thickness ratio of the surface layers A and C means the sum of the thickness ratios of both surface layers. In such a case, if the thickness ratio of the B layer is less than 50%, the bending fatigue resistance deteriorates and pinholes increase, which is not preferable. On the other hand, if the thickness ratio of the A layer or the A layer and the C layer exceeds 95%, the gas barrier property is insufficient, which is not preferable.

The polyamide-based mixed resin laminated film of the present invention has x (wt%) representing the content of MXD6 component in the film, t (mm) representing the thickness of the film, and Pa (ml / m 2 · MPa) representing the average oxygen permeability. It is preferable that (day) satisfies the relationship of the following formula (I) in order to satisfy gas barrier properties, pinhole resistance, and laminate adhesion at a high level. By satisfying the relationship of the formula (I), it is possible to obtain an economically excellent film having a high gas barrier property with a small MXD6 content in the film and having a small decrease in pinhole resistance.
Pa <1 / [t (0.015x + 0.15)] (I)
X is preferably in the range of 5 to 50 (% by weight), and t is preferably in the range of 0.008 to 0.050 (mm) (8 to 50 μm).
If the above relationship is not satisfied, for example, the content of MXD6 must be increased in order to compensate for the decrease in gas barrier properties. If the MXD6 content is increased, the resistance to pinholes deteriorates and the decrease in resistance to pinholes is compensated. Therefore, the amount of thermoplastic elastomer added must be increased.

  As a method satisfying the above mathematical relationship, (1) for example, the content of the resin other than MXD6 in the resin constituting the core layer is 10% by weight or less, preferably 5% by weight or less, particularly preferably 3% by weight. Hereinafter, it is most preferably 0% by weight. Further, when the core layer contains a resin other than MXD6, the temperature of the molten resin in the core layer is lowered as much as possible in the melt extrusion process, and the residence process from extrusion to casting is shortened. A gentle mixing method such as using an extruder with low kneading efficiency is used. (2) The layer configuration and the thickness ratio are set to the above-described ranges. In particular, the layer configuration is an A / B / A configuration of two or three layers, and the thickness ratio of the B layer is 15 to 30%. (3) Appropriate stretching conditions described in (6) below are adopted as the stretching method. There are methods. The present inventors have the effect of satisfying the relationship of the formula (I) by the combination of (1), (2), and (3), that is, satisfying the gas barrier property and the pinhole resistance with a small MXD6 content. I found a new thing.

  Next, the preferable manufacturing method for obtaining the polyamide-type mixed resin laminated | multilayer film roll of this invention is demonstrated. As a result of examining the thickness variation in the vertical direction of the film roll (thickness variation over the entire length of the film roll) and variation in physical properties such as boiling water shrinkage rate and variations, the present inventors have found that the thickness variation in the vertical direction and the variation in physical properties. It has been found that variations and variations are largely influenced by various factors in the casting process in which a molten resin is converted into an unstretched film. That is, if the temperature of the resin when supplying to a funnel-shaped popper directly connected to each extruder (hereinafter simply referred to as a hopper) is low, or if the moisture content of the resin supplied to the hopper is inappropriately adjusted Further, it was found that the thickness unevenness in the longitudinal direction of the unstretched film was increased, and the fluctuations and variations in physical properties of the biaxially stretched film were increased. In addition, when the resin extruded from the T die is wound around a metal roll, even if the contact point between the resin and the metal roll is disturbed, the thickness unevenness in the longitudinal direction in the unstretched film becomes large, and the physical properties in the biaxially stretched film It was found that the fluctuation and variation of Furthermore, it was also found that if the stretching conditions in the biaxial stretching process are inappropriate, the thickness unevenness in the longitudinal direction of the unstretched film is amplified, which promotes fluctuations and variations in physical properties.

Furthermore, as a result of intensive studies based on the above facts, the present inventors have taken the following measures when producing film rolls, and thus there are fluctuations in physical properties such as gas barrier properties and pinhole resistance at low temperatures. It has been determined that it is possible to obtain fewer film rolls.
(1) Uniformity of resin chip shape (2) Temperature retention during resin supply to hopper (3) Optimization of hopper shape (4) Addition of anti-segregation agent during resin mixing (5) Addition of anti-segregation agent Removal of adverse effects (6) Optimization of stretching conditions (7) Adjustment of fluidity during melting of resin forming each layer Hereinafter, each of the above-described means will be described in order.

(1) Uniformization of resin chip shape In the production of the film roll of the present invention, a blending method is adopted, a plurality of raw material resin chips having different compositions are blended in a hopper or a mixing mixer, and then melt-kneaded and an extruder. Extruded into a film. For example, when there are three types of resin as the raw material, each of the raw material resin chips is supplied to three hoppers in a continuous or intermittent manner, and finally passed through a buffer hopper as necessary. The three types of raw material resin chips are mixed again with a hopper immediately before or immediately above (hereinafter referred to as “final hopper”), and quantitatively supplied to the extruder according to the amount of extrusion to form a film.

  However, depending on the capacity or shape of the final hopper, when the amount of resin chips in the final hopper is large and when the remaining amount of resin chips in the final hopper is small, the material segregation phenomenon, that is, the extruder from the final hopper A phenomenon occurs in which the composition of the resin chips supplied to the substrate becomes different. Further, such segregation phenomenon appears particularly prominent when the shape or specific gravity of the resin chip is different. Further, due to such segregation phenomenon, physical properties such as maximum boiling water shrinkage rate, boiling water shrinkage direction difference, film thickness, and refractive index in the thickness direction vary when a long film is produced.

  That is, if there is a difference in the size of the resin chip, when the mixture of chips falls in the final hopper, small resin chips tend to fall first, so when the remaining amount of chips in the final hopper decreases, The ratio of large resin chips increases, which causes segregation of raw materials. Therefore, in order to obtain a film roll with little variation in physical properties, it is necessary to suppress the phenomenon of raw material segregation in the final hopper by combining the shapes of a plurality of types of resin chips to be used.

  Each resin chip of MXD-6, thermoplastic elastomer, and polyamide used as a raw material in the present invention is usually taken out from the polymerization apparatus in a molten state after polymerization, and immediately cooled with water, and then cut with a strand cutter. Formed. For this reason, the resin chip has an elliptical column shape with an elliptical cross section. Here, as a result of examining the relationship between the shape of the resin chip and the raw material segregation, the average major axis (mm), average minor axis (mm) of the cross-sectional ellipse of the other resin chips mixed with the most used resin chip, The average chip length (mm) is within ± 20% of the average major axis (mm), average minor axis (mm), and average chip length (mm) of the cross-sectional ellipse of the most used resin chip, respectively. The raw material segregation can be reduced by adjusting the range. In addition, the average major axis, the average minor axis, and the average chip length of the cross-sectional ellipse of the resin chip other than the resin chip with the most used amount are respectively the average major axis, the average minor axis of the sectional ellipse of the resin chip with the most used amount, Adjustment to a range within ± 15% of the average chip length is more preferable because the effect of preventing segregation becomes extremely remarkable.

(2) Keeping the temperature at the time of resin supply to each hopper If the chip after leaving it heated and dried to adjust the moisture content is left to cool to room temperature (room temperature) and then supplied to each hopper, A uniform film roll cannot be obtained. That is, in order to obtain the film roll of the present invention, it is necessary to supply the chips heated and dried by a blender or the like to each hopper while keeping the temperature high. Specifically, the chips heated and dried by the blender need to be supplied to each hopper while being maintained at 80 ° C. or higher, and more preferably supplied to each hopper while being maintained at 90 ° C. or higher. When the temperature of the chip supplied to each hopper is lower than 80 ° C., the resin bite becomes worse, causing vertical thickness variation, physical property fluctuations and variations, and the film roll of the present invention cannot be obtained. In addition, when drying a chip | tip with apparatuses, such as a blender, it is necessary to adjust drying temperature to 150 degrees C or less. If the drying temperature exceeds 150 ° C., hydrolysis may occur during drying, which is not preferable. In addition, when the temperature of the chip heat-dried by the blender falls below 80 ° C., it is necessary to reheat the chip to 80 ° C. or higher and supply it to the hopper.

(3) Optimization of hopper shape By using a funnel-shaped hopper as the final hopper and making its inclination angle 70 ° or more, large chips can be easily dropped as well as small chips. Since it descends while maintaining a horizontal plane, it is effective in reducing raw material segregation. A more preferable inclination angle is 75 ° or more. The inclination angle of the hopper is an angle between the funnel-shaped hypotenuse and the horizontal line segment. A plurality of hoppers may be used upstream of the final hopper. In this case, in any hopper, the inclination angle must be 70 ° or more, and more preferably 75 ° or more.

  It is also preferable to reduce the ratio of the fine powder generated due to the cutting of the raw material chips used in order to suppress fluctuations in the boiling water shrinkage rate. Since the fine powder promotes the occurrence of raw material segregation, it is preferable to remove the fine powder generated in the process and reduce the ratio of the fine powder contained in each hopper. The ratio of the fine powder contained is preferably within 1% by weight, and more preferably within 0.5% by weight throughout the entire process until the raw material chips enter each extruder. As a specific method for reducing the fine powder ratio, the fine powder is removed by passing a sieve at the time of chip formation with a strand cutter or by passing a cyclone air filter when the raw material chips are air-fed. The method of doing can be mentioned.

(4) Addition of anti-segregation agent during resin mixing Furthermore, as a means of reducing raw material segregation in each hopper, a sublimation anti-segregation agent is added in the mixing of polyamide resin and elastomer in each hopper. It is also preferable to do. As such a sublimation segregation preventing agent, a low boiling glycol can be used, and among them, polyoxyethylene / polyoxypropylene glycol can be suitably used. Further, the amount of the sublimation segregation inhibitor added to the MXD-6 raw material chip, the polyamide resin raw material chip and the elastomer raw material chip is 0.02% to 2.00% based on the total weight of the resin. It is preferable to be within the range. If it is less than 0.02%, it is not preferable because a sufficient segregation preventing effect cannot be obtained. On the other hand, if it is 2.00% or more, there is a possibility that it cannot be completely sublimated.

  In addition, as a means for reducing the raw material segregation in each hopper, it is also a preferable means to optimize the capacity of the hopper used. Here, the proper capacity of each hopper is in the range of 15 to 120% by weight with respect to the discharge amount per hour of the extruder, and 20 to 100 weight with respect to the discharge amount per hour of the extruder. % Is more preferable.

  In addition, as a method of mixing the raw material chip of MXD-6, the raw material chip of polyamide resin and the raw material chip of elastomer, it is supplied to the final hopper and each extruder via an intermediate hopper (buffer hopper) for mixing. It is also possible.

  In addition, when mixing multiple types of raw materials, each as polyamide-based resin and elastomer, mixing is performed while quantitatively supplying multiple types of raw materials into each hopper from a device that continuously supplies quantitative raw material chips. Or a method of mixing in advance using a blender or paddle dryer, etc., but when using the latter, the raw material chip size is set so that the raw material segregation does not occur when the mixture is discharged. Is preferably reduced.

(5) Elimination of adverse effects due to addition of segregation inhibitor (suction when molten resin contacts metal roll)
When a chip is melt extruded to obtain an unstretched film, a resin chip for forming each layer is melted and laminated at a temperature of 200 to 300 ° C. by each extruder using a coextrusion method. After being formed into a film (laminated sheet) by extruding from a T-die in a state of being hot, it is rapidly cooled by a method of winding around a cooling roll such as a metal roll cooled to a predetermined temperature. In addition, from the viewpoint of vertical thickness variation, physical property fluctuations, and variations, a preferable melt extrusion temperature is 240 ° C. to 290 ° C. In order to obtain the film roll of the present invention, when the molten resin is wound around the metal roll, the air gap (that is, the vertical distance from the exit of the T die lip to the chill roll surface) is adjusted to 20 to 60 mm, Using a suction device such as a vacuum box (vacuum chamber) with a wide suction port, the part that contacts the surface of the molten resin and the cooling roll is sucked across the entire width of the molten resin in the direction opposite to the winding direction. By doing so, it is preferable that the molten resin is forcibly adhered to the metal roll.

  And in that case, in order to prevent the situation where the sublimation segregation preventing agent described above impedes the adhesion of the molten resin to the cooling roll, the suction air velocity at the suction port is set to 2.0 to 7.0 m / sec. Need to be adjusted to 2.5 to 5.5 m / sec. It is more preferable to adjust to. Furthermore, the vacuum box may have a series of suction ports, but the suction ports are divided into a predetermined number of sections in the lateral direction in order to facilitate adjustment of the suction air velocity at the suction ports. It is preferable that the suction air speed can be adjusted for each section. Further, when the casting speed is increased, an accompanying flow is generated with the rotation of the metal roll, and the adhesion of the molten resin to the metal roll is hindered. In order to improve the degree of adhesion of the metal roll to the metal roll, a wide shield plate made of a soft material such as Teflon (registered trademark) is installed on the upstream side adjacent to the suction device (the metal roll rotates relative to the suction device). It is preferable to install on the side opposite to the direction) to block the accompanying flow. Furthermore, in order to obtain the film roll of the present invention, it is necessary to suppress the variation in the suction wind speed of the vacuum box within ± 20% of the average suction wind speed (set value), and more preferably within ± 10%. . In addition, it is preferable to adjust the suction force by providing a filter in the vacuum box and feeding back the differential pressure before and after the filter so that the suction wind speed of the vacuum box does not fluctuate due to oligomer dust or the like.

  Moreover, in order to obtain the film roll of the present invention, when the molten resin is wound around the cooling roll, a DC negative charge of 90 to 105 mA is applied to the molten resin sheet at 2 to 15 kv from the needle electrode, It is necessary to continuously contact and quench the metal roll while glow discharge. In this case, it is preferable to adjust the DC negative charge to be applied in the range of 7 to 14 kv because vertical thickness variation, physical property fluctuations and variations are reduced. Further, in order to obtain the film roll of the present invention, it is necessary to suppress the variation of the DC negative charge to be applied within an average negative charge (set value) of ± 20%, more preferably within ± 10%. .

(6) Optimization of stretching conditions As a method of biaxially stretching an unstretched film, the unstretched film is stretched in the longitudinal direction with a roll-type stretching machine and stretched in the transverse direction with a tenter-type stretching machine, followed by heat setting treatment and relaxation. It is necessary to employ a longitudinal / lateral stretching method for performing the treatment. Furthermore, in order to obtain the film roll of the present invention, it is necessary to adopt a so-called longitudinal-longitudinal-lateral stretching method as a biaxial stretching method. The longitudinal-longitudinal-lateral stretching method means that, in longitudinal stretching of a substantially unoriented film, the first-stage stretching is performed, and then the second-stage stretching is performed without cooling to Tg or less. , 3.0 times or more, preferably 3.5 times or more of transverse stretching and further heat setting. And in order to obtain the film roll of this invention, when performing longitudinal-longitudinal-lateral stretching mentioned above, it is necessary to make the longitudinal stretch ratio of the 1st stage higher than the longitudinal stretch ratio of the 2nd stage. That is, by making the first stage longitudinal draw ratio higher than the second stage longitudinal draw ratio, it is possible to obtain a film roll with good physical properties such as boiling water shrinkage and few variations in those physical properties. It becomes. In addition, when performing longitudinal-longitudinal-lateral stretching, it is usually easier to make the first-stage longitudinal stretching ratio lower than the second-stage longitudinal stretching ratio without causing sticking to the roll during the first-stage stretching. However, by using a special roll such as a Teflon (registered trademark) roll, even if the longitudinal stretch ratio of the first stage is higher than the longitudinal stretch ratio of the second stage, it causes sticking to the roll. It becomes possible to stretch easily.

  When performing longitudinal-longitudinal-lateral stretching as described above, the first-stage longitudinal stretching is preferably stretched about 2.0 to 2.4 times at a temperature of 80 to 90 ° C. When the draw ratio at the first stage is out of the above range and becomes high, the thickness unevenness in the vertical direction becomes large, which is not preferable. In addition, the longitudinal stretching in the second stage is preferably stretched about 1.3 to 1.7 times at a temperature of 65 to 75 ° C. If the draw ratio of the second stage falls outside the above range, it becomes unfavorable because the boil distortion increases and becomes unpractical.On the other hand, if the draw ratio of the second stage goes out of the above range, it becomes high. The strength in the direction (such as strength at 5% elongation) becomes low and becomes unpractical.

  Moreover, when performing longitudinal-longitudinal-lateral stretching as described above, hot roll stretching, infrared radiation stretching, or the like can be employed as the longitudinal stretching method. Further, when the polyamide-based mixed resin laminated film roll of the present invention is produced by such a longitudinal-longitudinal-lateral stretching method, not only the thickness variation in the longitudinal direction, the variation in physical properties and the variation are reduced, but also the lateral direction. Variations in physical properties and variations can be reduced. In the case of longitudinal-longitudinal-lateral stretching, the total longitudinal stretching condition is preferably 3.0 to 4.5 times.

  Moreover, when performing longitudinal-longitudinal-lateral stretching, it is preferable to stretch the lateral stretching at a temperature of 120 to 140 ° C. by about 4.0 to 5.5 times. If the transverse stretching ratio falls outside the above range, the transverse strength (5% elongation strength, etc.) becomes low and impractical, which is not preferable. Conversely, the transverse stretching ratio falls within the above range. If the deviation is high, the thermal contraction rate in the lateral direction is increased, which is not preferable. On the other hand, if the transverse stretching temperature falls outside the above range, it becomes unpreferable because the boil distortion becomes large and becomes impractical, and conversely, if the transverse stretching temperature rises outside the above range, It is not preferable because the strength (strength at 5% elongation, etc.) decreases and becomes impractical.

  Furthermore, in order to obtain the film roll of this invention, it is preferable to perform the heat setting process after longitudinal-longitudinal-lateral stretching at the temperature of 180-230 degreeC. If the temperature of the heat setting treatment falls outside the above range, the heat shrinkage rate in the longitudinal direction and the transverse direction increases, which is not preferable. On the contrary, if the temperature of the heat setting treatment rises outside the above range, biaxial stretching Since the impact strength of a film becomes low, it is not preferable.

  In addition, in order to obtain the film roll of the present invention, it is preferable to relax the relaxation treatment after heat setting by 2 to 10%. If the rate of relaxation treatment falls outside the above range, the thermal contraction rate in the longitudinal direction and the transverse direction increases, which is not preferable. Conversely, if the rate of relaxation treatment falls outside the above range, the longitudinal direction and the width direction The strength (such as strength at 5% elongation) becomes low and becomes unpractical.

  Further, the width of the film roll is not particularly limited, but from the viewpoint of easy handling, the lower limit of the width of the film roll is preferably 0.35 m or more, and more preferably 0.50 m or more. . On the other hand, the upper limit of the width of the film roll is preferably 2.5 m or less, more preferably 2.0 m or less, and further preferably 1.5 m or less. In addition, the winding length of the film roll is not particularly limited, but the lower limit of the winding length of the film roll is preferably 500 m or more and more preferably 1,000 m or more from the viewpoint of ease of winding and handling. . On the other hand, the upper limit of the roll length of the film roll is preferably 2,5000 m or less, more preferably 20,000 m or less, and further preferably 15,000 m or less. In addition, when a film thickness is about 15 micrometers, it is especially preferable in it being 12000 m or less. In addition, as the winding core, usually, paper of 3 inches, 6 inches, 8 inches, etc., a plastic core or a metal core can be used.

  On the other hand, the thickness of the film constituting the polyamide-based mixed resin laminated film roll of the present invention is not particularly limited. For example, the packaging film is preferably 8 to 50 μm, more preferably 10 to 30 μm.

  In addition, the polyamide-based mixed resin laminated film constituting the film roll of the present invention has a lubricant, an anti-blocking agent, a thermal stabilizer, an antioxidant, an antistatic agent, a light-proofing agent, a light-proofing agent within a range not impairing the properties. It is also possible to contain various additives such as impact modifiers. In particular, it is preferable to contain various inorganic particles for the purpose of improving the slipperiness of the biaxially stretched film. Moreover, it is preferable to add an organic lubricant such as ethylenebisstearic acid that exhibits the effect of reducing the surface energy because the slipping property of the film constituting the film roll becomes excellent.

  Furthermore, the polyamide-based mixed resin laminated film constituting the film roll of the present invention can be subjected to heat treatment or humidity control treatment in order to improve dimensional stability depending on the application. In addition, in order to improve the adhesion of the film surface, corona treatment, coating treatment, flame treatment, etc., and processing such as printing, vapor deposition and the like can be performed.

(7) Adjustment of fluidity during melting of resin forming each layer
As described above, when a chip is melt-extruded to obtain an unstretched film, a resin chip for forming each layer is melted and laminated by each extruder using a co-extrusion method. It is formed into a film by being extruded from a T-die. Conventionally, when producing a laminated film using a co-extrusion method, in such a casting process, it is preferable to uniform the fluidity of the resin forming each layer in order to make the thickness unevenness of the laminated film uniform. It was thought.

  However, in order for the inventors to produce a higher quality film roll, the relationship between the physical properties of the resin in the casting process, the melt extrusion conditions, the thickness variation of the unstretched film, the thickness of the biaxially stretched film, and the physical property variation. As a result of intensive studies, when manufacturing a film roll laminated with a polyamide-based mixed resin as in the present invention, it is not always necessary to unify the fluidity of the resin forming each layer in the casting process. It turned out that it cannot be said that it is preferable in order to make a spot and a physical property uniform. Then, the inventors, in the casting process, the fluidity at the time of melting of the resin forming the skin layer (hereinafter referred to as skin layer forming resin), the resin forming the core layer (hereinafter referred to as core layer forming resin). The resin for forming the skin layer and the core simultaneously fed into the extruder by making the resin for forming the skin layer easier to flow than the resin for forming the core layer. By extruding the skin layer forming resin from the die prior to the core layer forming resin among the layer forming resins, it is possible to prevent variations in the thickness of the skin layer and the core layer, and as a result, It was found that the variation in the thickness of the entire laminated film can be reduced, and the reason why such a phenomenon occurs is not clear, but the flow of the resin for forming the skin layer as described above is not clear. It is possible to smoothly extrude the hard MXD-6, which is the main component of the core layer, and reduce the friction between the polyamide resin, which is the main component of the skin layer, and the peripheral wall of the die. This is considered to be because it is possible to alleviate the phenomenon of the so-called “skinning” of the skin layer surface, and as a result, the variation of the thickness of the skin layer and the variation of the thickness of the core layer is suppressed, and the lamination is performed. It is considered that variation in the thickness of the entire film can be reduced, and variations in physical properties such as gas barrier properties, transparency, and resistance to pinholes at low temperatures can be reduced.

  In addition, as a method of lowering the fluidity at the time of melting of the skin layer forming resin relative to the fluidity at the time of melting of the core layer forming resin, the temperature of the extruder for forming the skin layer (specifically, The temperature near the extruder) is higher than the temperature of the extruder for forming the core layer (hereinafter referred to as the extrusion temperature adjustment method), and the relative viscosity (RV) and the reduced viscosity of the resin for forming the skin layer are used for forming the core layer. Method of lowering relative viscosity and reduced viscosity of resin (hereinafter referred to as relative / reduced viscosity adjustment method), Method of increasing moisture content of resin for skin layer formation above moisture content of resin for core layer formation (hereinafter referred to as moisture) (Referred to as an example of a method for measuring the relative viscosity and reduced viscosity of a polyamide-based resin or a thermoplastic elastomer will be described later).

  Of the above three methods, the extrusion temperature adjustment method has a higher fluidity at the time of melting the skin layer forming resin and the core layer forming resin than the relative / reduced viscosity adjusting method and the moisture content adjusting method. Although it can be changed, it is difficult to finely adjust the difference in fluidity when the two resins are melted to an appropriate range only by the extrusion temperature adjustment method. On the other hand, according to the relative / reduced viscosity adjustment method and the moisture content adjustment method, it is possible to finely adjust the fluidity at the time of melting both resins, but using only the relative / reduced viscosity adjustment method and the moisture content adjustment method, There is a limit to adjusting the difference in fluidity when both resins are melted to an appropriate range. Depending on the type and mixing ratio of the resin that forms the skin layer / core layer and the thickness ratio of the skin layer / core layer, relative / reduced so that the difference in fluidity during melting of both resins is the desired difference. Using the viscosity adjustment method, adjust the degree of polymerization of both resins, and then adjust the difference in fluidity between the two resins using the extrusion temperature adjustment method. -It is most preferable to perform fine adjustment that cannot be performed by the reduced viscosity adjustment method or the extrusion temperature adjustment method by the moisture content adjustment method. In addition, when the skin layer and the core layer are formed of a plurality of types of resins, the total relative viscosity and the reduced viscosity of the plurality of types of resins that form the skin layer are the total of the plurality of types of resins that form the core layer. A method of reducing the relative viscosity or reduced viscosity can be employed.

  In addition, in the relative / reduced viscosity adjustment method, the relative viscosity of the resin forming the skin layer and the core layer is in the range of 2.0 to 4.0, and the relative viscosity of the resin forming the skin layer is It is preferable to adjust the relative viscosity of the resin used in each layer so that the difference from the relative viscosity of the resin forming the core layer is 0.5 or less. In the extrusion temperature adjusting method, the resin temperature of the resin forming the skin layer and the core layer is in the range of 240 to 300 ° C., and the temperature difference between the resin forming the skin layer and the resin forming the core layer It is preferable to adjust the temperature of the resin forming each layer so that the temperature becomes 10 ° C. or lower. On the other hand, in the moisture content adjustment method, it is preferable to control the moisture content of the resin forming the skin layer within a range of 800 to 1200 ppm and to control the moisture content of the resin forming the core layer to 800 ppm or less.

  In addition, at the time of formation of an unstretched laminated film, the above-mentioned means (1) to (5) and (7) are used, and the means of (6) is used in the stretching process of the unstretched laminated film, thereby forming a laminated film. It becomes possible to reduce the thickness unevenness of each layer to be performed, and consequently to reduce the thickness unevenness of the entire laminated film. And it is thought that it becomes possible to reduce the physical property fluctuation | variation of a film roll very efficiently resulting from that. In addition, any one of the above-described means (1) to (7) does not effectively contribute to the reduction of the physical property fluctuation of the film roll, and the means (1) to (7) are combined. Therefore, it is considered that the change in physical properties of the film roll can be reduced very efficiently.

  Hereinafter, the present invention will be described in detail by way of examples. However, the present invention is not limited to the embodiments of the examples, and can be appropriately changed without departing from the spirit of the present invention. . Tables 1 to 4 show properties of raw material chips A to K used in Examples and Comparative Examples, compositions of raw material chips used in Examples and Comparative Examples, and film forming conditions of film rolls in Examples and Comparative Examples, respectively. Show.

  Chip A is composed of 99.85% by weight of nylon 6 (relative viscosity = 2.8, Tg = 41 ° C.) and 0.15% by weight of ethylenebisstearic acid amide, and chip B is made of nylon 6 (chip A). The same physical properties) 85.00% by weight, silica particles having an average particle diameter of 2.0 μm and a pore volume of 0.8 ml / g, 15.0% by weight, and chip C is made of nylon 6 (chip A). And the same physical properties) as 100.00% by weight. In addition, the shapes of the chips A to C are all elliptical cylinders, and have the same cross-sectional major axis, sectional minor axis, and chip length. Chip D is made of polymetaxylylene adipamide (MXD-6) having a relative viscosity of about 2.1, and chip E is polymetaxylylene adipamide (MXD-6) having a relative viscosity of about 2.65. MXD-6), chip F is made of a copolymer of nylon 6 and PTMG (polytetramethylene glycol) (relative viscosity = 2.0), and chip G is made of nylon 6 and It consists of a copolymer with PEG (polyethylene glycol) (relative viscosity = 2.4), and chip H is made of an ethylene / methacrylic acid copolymer (MFR (Melt Flow Rate) at 190 ° C.) = 2.4 g / Chip I is made of an ethylene-butene copolymer (MFR = 2.0 g / 10 minutes), and Chip J is made of an ethylene ionomer (M Are those consisting of R = 2.4 g / 10 minutes), the chip K is made of a copolymer of nylon 12 with PTMG (polytetramethylene glycol) (relative viscosity = 2.0). In addition, the shapes of the chips D to K are all elliptic cylinders, and the chips D to J have the same cross-sectional major axis, cross-sectional minor axis, and chip length. In addition, the measuring method of the relative viscosity (RV) and reduced viscosity of the raw material chip | tip used by the Example and the comparative example is shown below.

[Relative viscosity (RV)]
0.25 g of a sample was dissolved in 25 ml of 96% sulfuric acid, 10 ml of this solution was used, the falling seconds were measured at 20 ° C. using an Ostwald viscosity tube, and the relative viscosity was calculated from the following formula 7.
RV = t / t (subscript: 0) 7
Where t (subscript: 0): the number of seconds for the solvent to fall; t: the number of seconds for the sample solution to fall.

[Reduced viscosity (ηdp / c)]
0.1 g of a sample was dissolved in 25 ml of a mixed solvent of phenol / tetrachloroethane (weight ratio = 60/40), and using this solution, the number of seconds dropped at 30 ° C. was measured using an Ostwald viscosity tube. The reduced viscosity was calculated.
ηsp / c (dl / g) = {(t−t (subscript: 0)) / t (subscript: 0)} / c... 8
Where t (subscript: 0): solvent dropping seconds, t: sample solution dropping seconds, c: sample concentration (g / dl)

[Example 1]
Using a co-extrusion method, a polyamide-based mixed resin is melt-extruded (laminated in a die and extruded) from three extruders (first to third extruders), and turned to a rotating metal roll cooled to 17 ° C. By winding and quenching, an unstretched film (polyamide-based mixed resin laminated sheet) having a thickness of 257 μm and a two-layer / three-layer structure was obtained. At this time, the take-up speed of the unstretched film (rotational speed of the metal roll) is about 30 m / min. Met. The method for forming each layer of the unstretched film (steps until melt extrusion) is as follows. In the following description, the first layer, the second layer, and the third layer are referred to in order from the surface layer of the polyamide-based mixed resin laminated sheet (that is, the surface of the third layer is a metal roll contact surface).

-Formation of first layer (outer layer) The above chips A, B, D, and F were separately dried while heating to about 100 ° C for about 8.0 hours using a 15 kl blender apparatus. When a predetermined amount of each chip was sampled from the blender and the moisture content was measured, the moisture content of chips A, B, and D were all 1000 ppm. The moisture content was measured using a Karl Fischer moisture meter (MKC-210 manufactured by KYOTO Electronics) under the conditions of a sample weight of 1 g and a sample heating temperature of 230 ° C.

  Then, the chips A, B, D, and F in each blender after the preliminary drying were continuously and separately supplied into the mixing mixer with a quantitative screw feeder. The supply amount of chip A is 91.5 wt%, the supply amount of chip B is 0.5 wt%, the supply amount of chip D is 5.0 wt%, and the supply amount of chip F is 3.0 wt%. % By weight. In addition, polyoxyethylene / polyoxypropylene glycol (New Pole PE-64 manufactured by Sanyo Chemical Co., Ltd.) as a sublimation segregation preventing agent in a mixing mixer supplied with chips A, B, D, and F, chips E, It added so that it might become 1000 ppm with respect to the total weight of C and F.

  Thereafter, the mixed raw materials of chips A, B, D, and F mixed in the mixing mixer as described above were continuously and separately supplied to the hopper immediately above the extruder (first extruder) by a quantitative screw feeder. . The hopper had a capacity of 150 kg of raw material chips. The inclination angle of the hopper was adjusted to 70 °.

  Further, when the chips A, B, D, and F were supplied into the hopper, they were supplied to the hopper within a short time after drying so that the temperature of the chip in each blender would not become too low. The temperatures of chips A, B, D, and F immediately before being supplied to the hopper were all about 91 ° C. Then, the supplied chips A, B, D, and F (mixed ones) were mixed in a hopper, and melt-extruded from a T die at 273 ° C. by a single-screw first extruder.

-Formation of second layer (intermediate layer) The above-mentioned chip E was pre-dried while being heated to about 130 ° C for about 8.0 hours using a 15 kl blender apparatus. When a predetermined amount of chips was collected from the blender and the moisture content was measured by the method described above, the moisture content of chip E was 650 ppm.

  And each chip | tip in each blender after pre-drying was continuously supplied separately into the mixing mixer with the fixed amount screw feeder. The supply amount of chip E was 75% by weight, the supply amount of chip C was 22% by weight, and the supply amount of chip F was 3% by weight. In addition, polyoxyethylene polyoxypropylene glycol (New Pole PE-64 manufactured by Sanyo Chemical Co., Ltd.) as a sublimation segregation preventing agent in the mixing mixer to which chips E, C, F were supplied. It added so that it might become 1000 ppm with respect to the total weight of F.

  Thereafter, the chip E was continuously supplied to the hopper immediately above the extruder (second extruder) with a fixed screw feeder. The hopper had a capacity of 150 kg of raw material chips. The inclination angle of the hopper was adjusted to 70 °.

  Moreover, when supplying the chip | tip E in a hopper, it supplied to the hopper within a short time after drying so that the temperature of the chip | tip in each blender might not become low too much. The temperature of the tip E just before being supplied to the hopper was about 91 ° C. And the supplied chip | tip E was melt-extruded from the T die at 276 degreeC with the single screw type 2nd extruder.

-Formation of third layer (inner layer) The above-mentioned chips A, B, D, and F were separately dried using a 15 kl blender apparatus while heating to about 100 ° C for about 8.0 hours. When a predetermined amount of each chip was collected from the blender and the moisture content was measured by the method described above, the moisture content of the chips A, B, D, and F was all 1000 ppm.

  Then, chips A, B, D, and F in each blender after the preliminary drying were continuously and separately supplied into the mixing mixer with a quantitative screw feeder. The supply amount of chip A is 91.5 wt%, the supply amount of chip B is 0.5 wt%, the supply amount of chip D is 5.0 wt%, and the supply amount of chip F is 3.0 wt%. % By weight. In addition, polyoxyethylene / polyoxypropylene glycol (New Pole PE-64 manufactured by Sanyo Chemical Co., Ltd.) as a sublimation segregation preventing agent in a mixing mixer supplied with chips A, B, D, and F, chips E, It added so that it might become 1000 ppm with respect to the total weight of C and F.

  Thereafter, the mixed raw materials of chips A, B, D, and F mixed in the mixing mixer as described above were continuously and separately supplied to the hopper directly above the extruder (third extruder) with a quantitative screw feeder. . The hopper had a capacity of 150 kg of raw material chips. The inclination angle of the hopper was adjusted to 70 °.

  Further, when the chips A, B, D, and F were supplied into the hopper, they were supplied to the hopper within a short time after drying so that the temperature of the chip in each blender would not become too low. The temperatures of chips A, B, D, and F immediately before being supplied to the hopper were all about 91 ° C. Then, the supplied chips A, B, D, and F were mixed in a hopper, and melt-extruded from a T die at 273 ° C. by a single-screw third extruder.

  In the first and third extruders of Example 1, the average major axis, the average minor axis, and the average chip length of the resin chips (Chips B, D, and F) other than the most used resin chip (Chip A) The length is included within a range of ± 20% with respect to the average major axis, average minor axis, and average chip length of the resin chip (Chip A) that is used most. Moreover, the discharge amount of the 1st-3rd extruder in formation of an unstretched film was adjusted so that the thickness ratio of 1st layer / 2nd layer / 3rd layer might be 6/3/6.

  In addition, the air gap when the molten resin is wound around the metal roll is adjusted to 40 mm, and by applying a negative DC charge of 100 mA at 11 ± 1.1 kv from the needle electrode to the molten film, glow discharge is performed. The molten resin was electrostatically adhered to a metal roll. Further, when the molten resin is wound around the metal roll, the portion where the molten resin comes into contact with the metal roll is opposite to the direction in which the resin is wound using the vacuum box over the entire width of the molten resin. By attracting in the direction, adhesion of the molten resin to the metal roll was promoted. The suction air velocity of the vacuum box is 5.0 ± 0.5 m / sec. Over the entire width of the suction port (that is, the entire width of the molten resin). It adjusted so that it might become.

  Thereafter, the obtained unstretched film was longitudinally stretched (first longitudinal stretching) about 1.94 times at a stretching temperature of about 93 ° C. by a Teflon (registered trademark) roll, and then stretched at a stretching temperature of about 80 by a ceramic roll. Longitudinal stretching (second longitudinal stretching) was performed at about 1.8 times at a temperature. Further, the longitudinally stretched sheet is continuously led to a tenter, transversely stretched 4.2 times at about 130 ° C., heat-set at about 210 ° C., subjected to 5.0% lateral relaxation treatment, and then cooled. By cutting and removing both edges, a biaxially stretched film of about 15 μm was continuously formed over 2000 m to produce a mill roll. When the obtained biaxially stretched laminated film was sliced thinly in the thickness direction and observed with an electron microscope, the thicknesses of the first layer, the second layer, and the third layer were about 6 μm, about 3 μm, It was about 6 μm.

  In addition, the fluctuation range of the film surface temperature when the film is continuously produced 2000 m is the average temperature ± 0.8 ° C. in the preheating step, the average temperature ± 0.6 ° C. in the stretching step, and the average temperature ± 0.5 ° C. in the heat treatment step. It was in the range. Further, the obtained mill roll was slit into a width of 400 mm and a length of 2000 m, wound around a 3-inch paper tube, and two polyamide-based mixed resin laminated film rolls (slit rolls) were obtained. Then, using the obtained two slit rolls (namely, those obtained from the same mill roll), the characteristics were evaluated by the following method. In the following BS (boiling water shrinkage), BSx (maximum boiling water shrinkage), BSd (boiling water shrinkage direction difference), and refractive index measurement, the first sample cut-out portion is within 2 m from the end of film winding. Installed, the second to twentieth sample cutout sections are provided approximately every 100 m from the first sample cutout section, and the 21st sample cutout section is provided within 2 m from the beginning of film winding. A sample film was cut out from each of the sample cutout portions. The evaluation results are shown in Tables 5-8. When showing the evaluation results, for the impact strength and the laminate strength, the measured average values of the sample samples and the fluctuation range of the values of the sample samples were shown. For S-curl, the number of sample samples at each evaluation level and the overall evaluation level of all sample samples are shown.

[Boiling water shrinkage]
A biaxially oriented film (sample film) cut out from each cut-out portion of one slit roll was cut into a square shape with a side of 21 cm and left for 2 hours or more in an atmosphere of 23 ° C. and 65% RH. Draw a circle with a diameter of 20 cm centered on the center of the sample, draw a straight line passing through the center of the circle in the direction of 0 to 165 ° clockwise at 15 ° intervals, with the vertical direction (film drawing direction) being 0 °. The diameter in the direction was measured and taken as the length before treatment. The cut sample was then heat-treated in boiling water for 30 minutes, then removed and wiped off the moisture adhering to the surface, air-dried, and left in an atmosphere of 23 ° C. and 65% RH for 2 hours or more, as described above. The length of the straight line drawn in each diametric direction is measured and set as the length after treatment, and BS (boiling water shrinkage rate), BSx (maximum boiling water shrinkage rate), BSax (average boiling water shrinkage rate), BSd (boiling water shrinkage direction difference) and BSad (average boiling water shrinkage direction difference) were calculated.

  Then, the maximum / minimum in the maximum boiling water shrinkage (BSx) of all the samples is obtained, and the difference between the larger one of the maximum / minimum average boiling water shrinkage (BSax) and the average boiling water shrinkage And the ratio (%) of the difference to the average boiling water shrinkage (BSax) was calculated to obtain the variation rate of the maximum boiling water shrinkage (BSx) with respect to the average boiling water shrinkage (BSax). In addition, the maximum / minimum difference in boiling water shrinkage direction difference (BSd) of all samples is obtained, and the difference between the maximum / minimum average boiling water shrinkage direction difference (BSad) and the average boiling water shrinkage rate. The difference in boiling water shrinkage direction difference (BSd) with respect to the average boiling water shrinkage direction difference (BSad) is calculated by calculating the ratio (%) of the difference to the average boiling water shrinkage direction difference (BSad). The rate was determined.

[Three-dimensional surface roughness]
About the surface of the biaxially oriented film (sample film) cut out from each cutout portion of one slit roll, using a stylus type three-dimensional surface roughness meter (SE-3AK, manufactured by Kosaka Laboratory Ltd.), Under the conditions of a needle radius of 2 μm, a load of 30 mg, and a needle speed of 0.1 mm / s, the film was measured in the longitudinal direction of the film with a cut-off value of 0.25 mm over a measurement length of 1 mm and divided into 500 points at intervals of 2 μm. Moreover, it measured over 0.3 mm of measurement length on the film width direction on the same conditions as the above, and it divided | segmented into 150 points | intervals at 2 micrometer intervals. The three-dimensional height of each of the obtained dividing points is analyzed using a three-dimensional roughness analyzer (manufactured by Kosaka Laboratory Ltd., TDA-21), and the three-dimensional average surface roughness (nm). )

[Haze]
About each biaxially oriented film cut out from each cut-out part of the slit roll, JIS
Based on K7136, it measured using the haze meter (Nippon Denshoku Industries Co., Ltd. make, 300A). In addition, the measurement was performed twice and the average value was calculated | required.

[Vertical thickness unevenness]
The slit roll was slit to a width of about 3 cm over the entire length in the longitudinal direction to prepare a slit roll for thickness spot measurement. Thereafter, an average thickness, a maximum thickness, and a minimum thickness over the entire length in the longitudinal direction were determined using a thickness spot measuring device (wide range high sensitivity electronic micrometer K-313A) manufactured by Anritsu Corporation. Then, by calculating the difference between the average thickness and the difference between the average thickness of the maximum thickness and the minimum thickness and calculating the ratio (%) of the difference to the average thickness by the following formula 9. The variation rate of thickness over the entire length in the longitudinal direction was calculated.
Variation rate of thickness = | maximum thickness or minimum thickness−average thickness | / average thickness × 100... 9

[Refractive index]
Using an “Abbe refractometer 4T type” manufactured by Atago Co., Ltd., each sample film cut out from each sample cut-out part was left in an atmosphere of 23 ° C. and 65% RH for 2 hours or more, and then the refractive index in the thickness direction ( Nz) was measured. Also, the average average refractive index of all sample films is calculated, and as shown in Table 6, the difference between the maximum or minimum Nz and the average refractive index in all samples is calculated, and the ratio of the difference to the average refractive index is calculated. Was calculated as the rate of change.

[Impact strength]
Each sample film cut out from each cut-out part was allowed to stand in an atmosphere of 23 ° C. and 65% RH for 2 hours or more, and then a “film impact tester TSS type” manufactured by Toyo Seiki Seisakusho was used. The breaking strength was measured with a hemispherical impactor to determine the impact strength. The average impact strength of all sample films was also calculated.

[Content of elastomer component]
Each sample film cut out from each cut-out section is cut perpendicularly to the surface and perpendicular to the winding direction to produce an ultrathin section, and dyed with phosphotungstic acid and ruthenium oxide by the ultrathin piece method The sample was prepared. Thereafter, an electron micrograph (thickness direction: about 160 mm × winding direction: about 220 mm) was taken with a transmission electron microscope (JEM2010) manufactured by JEOL Ltd. at a magnification of 10,000 times. And the ratio which occupies for the whole area of the elastomer part dye | stained with phosphotungstic acid and ruthenium oxide using the image processing apparatus (analySIS) by JEOL Ltd. was computed as a content rate of an elastomer component.

[Tensile modulus]
Each sample film cut out from each cut-out part was sampled to a length of 150 mm and a width of 15 mm, and conditioned for 24 hours in an atmosphere of a temperature of 23 ° C. and a relative humidity of 50%. Then, under the conditions of a temperature of 23 ° C. and a relative humidity of 50%, in accordance with JIS K-7127, using an autograph AG-100E type manufactured by Shimadzu Corp. The tensile modulus was calculated as the ratio of the tensile stress within the tensile proportional limit and the corresponding strain.

[Oxygen permeability (gas barrier property)]
The film cut out from each cut-out part was oxygen-substituted for 2 days in an atmosphere of humidity 65% RH and temperature 25 ° C., and then the oxygen permeability according to JIS-K-7126 (Method B). The measurement was performed using a measuring device (OX-TRAN 2/20: manufactured by MOCOM).

[Lamination workability]
A biaxially oriented film constituting the slit roll using a slit roll (obtained from the same mill roll) different from the slit roll whose boiling water shrinkage rate, longitudinal thickness unevenness, refractive index, and impact strength were measured. After applying urethane AC agent (“EL443” manufactured by Toyo Morton Co., Ltd.) to the surface, a 15 μm-thick LDPE (low density polyethylene) film was formed at 315 ° C. using a single test laminator device manufactured by Modern Machinery. Further, an LLDPE (Linear Low Density Polyethylene) film having a thickness of 40 μm was continuously laminated thereon to obtain a laminate film roll having a three-layer laminated structure made of polyamide-based mixed resin / LDPE / LLDPE. Moreover, the workability at the time of manufacturing a laminate film roll was evaluated in the following three stages.
○: No wrinkle on the roll and condition adjustment is not required. Δ: Roll wrinkle is eliminated by condition adjustment. ×: No matter how the condition is adjusted, wrinkle is generated on the roll.

[Lamination strength]
In addition, the laminate film cut out from the laminate film roll was cut out into a width of 15 mm and a length of 200 mm as a test piece, and “Tensilon UMT-II-500 type” manufactured by Toyo Baldwin Co., Ltd. was used. The peel strength between the polyamide-based mixed resin laminated film layer and the LDPE layer was measured under conditions of a humidity of 65%. The tensile rate was 10 cm / min, the peel angle was 180 degrees, and water was added to the peeled portion for measurement. The laminate strength is measured by cutting out the first sample piece within 2 m from the end of winding of the laminate film roll, and cutting out the second to twentieth sample pieces every about 100 m from the cut out portion of the first sample piece. The 21st sample piece was cut out within 2 m from the beginning of winding of the film, and the measurement was performed on each of the first to 21st sample pieces. Moreover, the average of those measured values was also calculated.

[Pinhole resistance at low temperatures]
The laminate film cut out from the laminate film roll was cut into a size of 20.3 cm (8 inches) × 27.9 cm (11 inches), and the rectangular test film (laminated film) after the cutting was cut at a temperature of about 5 ° C. Under the above conditions, it was conditioned for 24 hours or more. Thereafter, the rectangular test film is wound into a cylindrical shape having a length of 20.32 cm (8 inches). Then, one end of the cylindrical film is fixed to the outer periphery of a disk-shaped fixing head of a gel bow flex tester (manufactured by Rigaku Kogyo Co., Ltd., NO.901 type) (conforming to the standard of MIL-B-131C). The other end of the tester was fixed to the outer periphery of a disk-shaped movable head of a tester facing the fixed head at a distance of 17.8 cm (7 inches). Then, the movable head is rotated 440 ° while approaching the fixed head in the direction of 7.6 cm (3.5 inches) along the axis of both heads opposed in parallel, and then 6.4 cm (without rotation) 2.5-inch) A one-cycle bending test in which the movement is performed in the reverse direction and the movable head is returned to the initial position is performed continuously for 500 cycles at a rate of 40 cycles per minute. Repeated. Thereafter, the number of pinholes generated in a portion within 17.8 cm (7 inches) × 27.9 cm (11 inches) excluding the portion fixed to the outer periphery of the fixed head and movable head of the tested film was measured (ie, The number of pinholes per 497 cm ² (77 square inches) was measured). In the measurement of pinhole resistance at a low temperature, the first sample piece is cut out within 2 m from the end of winding of the laminate film roll in the same manner as the measurement of the laminate strength described above. The second to twentieth sample pieces were cut out at intervals of about 100 m from the portion, the 21st sample piece was cut out within 2 m from the beginning of film winding, and the measurement was performed on each of the first to 21st sample pieces. Moreover, the average of those measured values was also calculated.

[S-curl phenomenon]
The laminate film wound up as a laminate film roll as described above is folded into two parallel to the winding length direction using a test sealer manufactured by Seibu Machinery Co. Then, 10 mm in the vertical direction was intermittently heat-sealed at intervals of 150 mm to obtain a semi-finished product having a width of 200 mm. This was cut in the winding length direction and both edges were cut so that the seal portion was 10 mm, and then cut at the boundary of the seal portion in the direction perpendicular to this to produce a three-side seal bag (seal width: 10 mm). . From these three-sided sealing bags, a three-sided sealing bag made from a portion within 2 m from the end of winding of the laminate film roll is selected as the first sample, and about 100, 200,..., 1800, 3900 sealed bags produced from 1900 m apart were selected as the second to 20th samples, respectively, and 3 produced from the portion within 2 m from the start of the lamination film roll. A side seal bag was selected as the 21st sample. And after heat-treating those 21 three-way seal bags for 30 minutes in boiling water, hold them in an atmosphere of 23 ° C. and 65% RH all day and night. A load of 1 kg was applied to the entire surface of the bag, and the bag was removed after being held for a whole day and night, and the degree of bag curl (S-curl) was evaluated as follows.
◎: No warping at all. ○: Slight warping is observed. X: Warping is clearly observed. XX: Warping is remarkable.

[Example 2]
In the formation of the first layer and the third layer, Examples were changed except that the preliminary drying conditions of the raw material chips A, B, D, and F were changed to a method of heating to about 120 ° C. over about 8.0 hours. 1, a polyamide-based mixed resin laminated film roll was obtained. After pre-drying, a predetermined amount of each chip was sampled from the blender and the moisture content was measured. As a result, the moisture content of chips A, B, D, and F was all 800 ppm, and the chip just before being supplied to the hopper. The temperatures of A, B, D, and F were all about 91 ° C. And the characteristic of the obtained film roll was evaluated by the method similar to Example 1. FIG. The evaluation results are shown in Tables 5-8.

[Example 3]
In the formation of the second layer, a polyamide-based mixed resin laminated film roll was obtained in the same manner as in Example 1 except that the extrusion temperature of the molten resin was changed to 274 ° C. And the characteristic of the obtained film roll was evaluated by the method similar to Example 1. FIG. The evaluation results are shown in Tables 5-8.

[ Reference Example 1 ]
When laminating each molten resin sheet melt-extruded from the first to third extruders, the first to second layers / second layer / third layer have a thickness ratio of 5/5/5. A polyamide-based mixed resin laminated film roll was obtained in the same manner as in Example 1 except that the discharge amount of the third extruder was adjusted. When the obtained biaxially stretched laminated film was sliced thinly in the thickness direction and observed with an electron microscope, the thicknesses of the first layer, the second layer, and the third layer were about 5.0 μm, about It was 5.0 μm and about 5.0 μm. And the characteristic of the obtained film roll was evaluated by the method similar to Example 1. FIG. The evaluation results are shown in Tables 5-8.

[Example 4 ]
The unstretched film obtained in the same manner as in Example 1 was longitudinally stretched about 2.04 times (first longitudinal stretching) at a stretching temperature of about 93 ° C. by a Teflon (registered trademark) roll, and then by a ceramic roll. The film was stretched longitudinally (second longitudinal stretching) by about 1.7 times at a stretching temperature of about 80 ° C. Further, as in Example 1, the longitudinally stretched sheet was continuously led to a stenter, transversely stretched 4.2 times at about 130 ° C., and heat-set at about 210 ° C. to be 5.0% transverse After the relaxation treatment, the film was cooled and both edges were cut and removed to continuously form a biaxially stretched film of about 15 μm over 2000 m. The fluctuation range of the film surface temperature when the film was continuously produced was the same as in Example 1. The obtained film was slit and wound in the same manner as in Example 1 to obtain a polyamide-based mixed resin laminated film roll. And the characteristic of the obtained film roll was evaluated by the method similar to Example 1. FIG. The evaluation results are shown in Tables 5-8.

[Example 5 ]
The unstretched film obtained in the same manner as in Example 1 was longitudinally stretched in two stages in the same manner as in Example 1. Thereafter, the longitudinally stretched sheet was continuously guided to a stenter, stretched 3.8 times at about 130 ° C., and heat-set at about 212 ° C. in the same manner as in Example 1 to obtain 3.0% After the relaxation treatment, the film was cooled and both edges were cut and removed to continuously form a biaxially stretched film of about 15 μm over 2000 m. The fluctuation range of the film surface temperature when the film was continuously produced was the same as in Example 1. The obtained film was slit and wound in the same manner as in Example 1 to obtain a polyamide-based mixed resin laminated film roll. And the characteristic of the obtained film roll was evaluated by the method similar to Example 1. FIG. The evaluation results are shown in Tables 5-8.

[Example 6 ]
In the formation of the first to third layers, when the raw material chips in the blender or mixing mixer are supplied to the hopper immediately above each extruder (first to third extruder), the inclination angle of each hopper is set to 65 °. Except having changed, it carried out similarly to Example 1, and obtained the polyamide-type mixed resin laminated | multilayer film roll. And the characteristic of the obtained film roll was evaluated by the method similar to Example 1. FIG. The evaluation results are shown in Tables 5-8.

[Example 7]
In the formation of the first and third layers, when the chips A, B, D, and F in each blender are supplied to the mixing mixer, the supply amount of the chip A is 89.5% by weight, and the supply amount of the chip B Was 0.5 wt%, the supply amount of chip D was 5.0 wt%, and the supply amount of chip F was 5.0 wt%. Other than that was carried out similarly to Example 1, and obtained the polyamide-type mixed resin laminated | multilayer film roll. And the characteristic of the obtained film roll was evaluated by the method similar to Example 1. FIG. The evaluation results are shown in Tables 5-8.

[Example 8 ]
The raw material chip G is used instead of the raw material chip F as a raw material for forming the first and third layers, and the chips A, B, D, and G in each blender are mixed in the formation of the first and third layers. When supplying to the mixer, the supply amount of chip A is 89.5 wt%, the supply amount of chip B is 0.5 wt%, the supply amount of chip D is 5.0 wt%, and the supply of chip G The amount was 5.0% by weight. Other than that was carried out similarly to Example 1, and obtained the polyamide-type mixed resin laminated | multilayer film roll. And the characteristic of the obtained film roll was evaluated by the method similar to Example 1. FIG. The evaluation results are shown in Tables 5-8. In the first and third extruders of Example 8 , the average major axis, the average minor axis, and the average chip length of the resin chips (Chips B, D, and G) other than the resin chip (Chip A) that is used the most. The length is included within a range of ± 20% with respect to the average major axis, average minor axis, and average chip length of the resin chip (Chip A) that is used most.

[Example 9 ]
A polyamide-based mixed resin laminated film roll was obtained in the same manner as in Example 1 except that the raw material chip H was used instead of the raw material chip F as the raw material for forming the first and third layers. And the characteristic of the obtained film roll was evaluated by the method similar to Example 1. FIG. The evaluation results are shown in Tables 5-8. In the first and third extruders of Example 9 , the average major axis, the average minor axis, and the average chip length of the resin chips (Chips B, D, and H) other than the resin chip (Chip A) that is used the most. The length is included within a range of ± 20% with respect to the average major axis, average minor axis, and average chip length of the resin chip (Chip A) that is used most.

[Example 10 ]
A polyamide-based mixed resin laminated film roll was obtained in the same manner as in Example 1 except that the raw material chip I was used instead of the raw material chip F as a raw material for forming the first and third layers. And the characteristic of the obtained film roll was evaluated by the method similar to Example 1. FIG. The evaluation results are shown in Tables 5-8. In the first and third extruders of Example 10 as well, the average major axis, average minor axis, and average chip length of the resin chips (Chips B, D, and I) other than the most used resin chip (Chip A) are used. The length is included within a range of ± 20% with respect to the average major axis, average minor axis, and average chip length of the resin chip (Chip A) that is used most.

[Example 11 ]
A polyamide-based mixed resin laminated film roll was obtained in the same manner as in Example 1 except that the raw material chip J was used instead of the raw material chip F as a raw material for forming the first and third layers. And the characteristic of the obtained film roll was evaluated by the method similar to Example 1. FIG. The evaluation results are shown in Tables 5-8. In the first and third extruders of Example 11 as well, the average major axis, average minor axis, and average chip length of the resin chips (Chips B, D, and J) other than the most used resin chip (Chip A) are used. This is included in a range of ± 20% or less with respect to the average major axis, average minor axis, and average chip length of the most used resin chip (chip E).

[Comparative Example 1]
When forming an unstretched resin sheet, a single-layer structure of only the second layer is formed without forming the first layer and the third layer, and the raw material chips A, B, E, F are used as raw materials for forming the second layer. In the second layer formation, when the chips A, B, E, and F in each blender are supplied to the mixing mixer, the supply amount of the chip A is 74.5% by weight, and the supply amount of the chip B is 0. A polyamide-based mixed resin film roll was obtained in the same manner as in Example 1 except that 5 wt%, the supply amount of chip E was 22 wt%, and the supply amount of chip F was 3 wt%. And the characteristic of the obtained film roll was evaluated by the method similar to Example 1. FIG. The evaluation results are shown in Tables 5-8.

[Comparative Example 2]
In the formation of the first layer and the third layer, the preliminary drying conditions of the raw material chips A, B, D, and F are changed to a method of heating to about 125 ° C. over about 8.0 hours, and the second layer In the same manner as in Example 1, except that the pre-drying conditions of the raw material chips E were changed to a method of heating to about 100 ° C. over about 8.0 hours, a polyamide-based mixed resin laminated film roll Got. When a predetermined amount of chips A, B, D, and F after preliminary drying were collected from the blender and the moisture content was measured, the moisture content of chips A, B, D, and F was all 700 ppm. The temperature of chips A, B, D, and F (mixed ones) immediately before being supplied to the wafer was about 91 ° C. On the other hand, when a predetermined amount of the pre-dried chip E was collected from the blender and the moisture content was measured, the moisture content of the chip E was 1000 ppm, and the temperature of the chip E immediately before being supplied to the hopper was about 91 ° C. It was. And the characteristic of the obtained film roll was evaluated by the method similar to Example 1. FIG. The evaluation results are shown in Tables 5-8.

[Comparative Example 3]
A polyamide-based mixed resin laminated film roll in the same manner as in Example 1 except that instead of the raw material chip E, the raw material chip D (RV = 2.1) was used as the raw material for forming the second layer, Got. And the characteristic of the obtained film roll was evaluated by the method similar to Example 1. FIG. The evaluation results are shown in Tables 5-8.

[Comparative Example 4]
In the formation of the first and third layers, when the chips A, B, D, and F in each blender are supplied to the mixing mixer, the supply amount of the chip A is 94.4% by weight, and the supply amount of the chip B Was 0.5 wt%, the supply amount of chip D was 5.0 wt%, and the supply amount of chip F was 0.1 wt%. Other than that was carried out similarly to Example 1, and obtained the polyamide-type mixed resin laminated | multilayer film roll. And the characteristic of the obtained film roll was evaluated by the method similar to Example 1. FIG. The evaluation results are shown in Tables 5-8.

[Comparative Example 5]
A polyamide-based mixed resin laminated film roll was obtained in the same manner as in Example 1 except that the raw material chip K was used instead of the raw material chip F as a raw material for forming the first and third layers. And the characteristic of the obtained film roll was evaluated by the method similar to Example 1. FIG. The evaluation results are shown in Tables 5-8. In the first and third extruders of Comparative Example 5, the average major axis and the average chip length of the resin chip (chip K) other than the resin chip (chip A) that is the most used are the most used. The average major axis and the average chip length of the resin chip (Chip A) are not included within a range of ± 20%, respectively.

[Comparative Example 6]
In the formation of the first to third layers, when the raw material chips in the blender or mixing mixer are supplied to the hopper immediately above each extruder (first to third extruder), the inclination angle of each hopper is set to 45 °. Except having changed, it carried out similarly to Example 1, and obtained the polyamide-type mixed resin laminated | multilayer film roll. And the characteristic of the obtained film roll was evaluated by the method similar to Example 1. FIG. The evaluation results are shown in Tables 5-8.

[Comparative Example 7]
In the formation of the first to third layers, the raw material chips A, B, D, F and the raw material chip E are supplied to the hopper directly above each extruder directly after being preliminarily dried or via a mixing mixer. A polyamide-based mixed resin laminated film roll was obtained in the same manner as in Example 1 except that it was left in each blender for about 5 hours. In addition, when a predetermined amount of chips A, B, D, and F after pre-drying were collected from the blender and the moisture content was measured, the moisture content of the chips A, B, D, and F was all 1000 ppm. The temperature of the chips A, B, D, and F (mixed ones) immediately before being supplied to was about 30 ° C. On the other hand, when a predetermined amount of the chip E after preliminary drying was collected from the blender and the moisture content was measured, the moisture content of the chip E was 650 ppm, and the temperature of the chip E immediately before being supplied to the hopper was about 30 ° C. It was. And the characteristic of the obtained film roll was evaluated by the method similar to Example 1. FIG. The evaluation results are shown in Tables 5-8.

[Comparative Example 8]
The unstretched film obtained in the same manner as in Example 1 was longitudinally stretched (first longitudinal stretching) by about 1.5 times at a stretching temperature of about 93 ° C. with a Teflon (registered trademark) roll, and then with a ceramic roll. The film was stretched longitudinally (second longitudinal stretching) about 2.3 times at a stretching temperature of about 80 ° C. Furthermore, the longitudinally stretched sheet is continuously guided to a stenter, and is stretched in the same manner as in Example 1, and is subjected to a lateral relaxation treatment by heat fixing and then cooled, and both edges are cut and removed. A biaxially stretched film of about 15 μm was continuously formed over 2000 m. The fluctuation range of the film surface temperature when the film was continuously produced was the same as in Example 1. Thereafter, the resulting film was slit and wound in the same manner as in Example 1 to obtain a polyamide-based mixed resin laminated film roll. And the characteristic of the obtained film roll was evaluated by the method similar to Example 1. FIG. The evaluation results are shown in Tables 5-8.

[Comparative Example 9]
When laminating each molten resin sheet melt-extruded from the first to third extruders, the raw material chips E and C are used as the raw material for forming the second layer, and in forming the second layer, the chip E in each blender , C is supplied to the mixing mixer, the supply amount of chip E is 75% by weight, the supply amount of chip C is 25% by weight, and the thickness ratio of the first layer / second layer / third layer is 5. A polyamide-based mixed resin film roll was obtained in the same manner as in Example 1 except that the discharge amount of the first to third extruders was adjusted to be 25 / 4.5 / 5.25. And the characteristic of the obtained film roll was evaluated by the method similar to Example 1. FIG. The evaluation results are shown in Tables 5-8.

[Effects of Example Film]
From Tables 5 to 8, the film rolls of Examples and Reference Examples all have very small thickness unevenness in the longitudinal direction throughout the roll, boiling water shrinkage rate, refractive index, tensile elastic modulus, oxygen permeability, transparency. It can be seen that the variation in physical properties is small. In addition, it can be seen that all of the film rolls of Examples having small variations in physical properties such as boiling water shrinkage and refractive index do not cause the S-curl phenomenon and have good laminating properties. Moreover, it can be seen that the films constituting the film rolls of the examples have low oxygen permeability, good impact strength (toughness) and transparency, and high laminate strength. On the other hand, the film roll of the comparative example has thickness fluctuations in the vertical direction over the entire roll, and fluctuations in physical properties such as boiling water shrinkage rate, refractive index, tensile elastic modulus, oxygen permeability, pinhole resistance, and transparency. It can be seen that the S-curl phenomenon is observed and the laminate processability, impact strength and transparency are poor.

  Since the polyamide-based mixed resin laminated film roll of the present invention has excellent processing characteristics as described above, it can be suitably used for food retort processing.

Claims (23)

A polyamide-based mixed resin obtained by laminating a resin layer B containing polymetaxylylene adipamide in a content ratio of 90 to 100% by weight and a resin layer A mainly composed of a polyamide-based resin in an A / B / A configuration. A polyamide-based mixed resin laminated film roll obtained by winding a laminated film so that the width is 0.2 m or more and 3.0 m or less and the length is 300 m or more and 30000 m or less, and the sum of the thickness ratios of both surface layers A is 70-85%,
A polyamide-based mixed resin laminated film roll characterized by satisfying the following requirements (1) to (4).
(1) In the resin layer A mainly composed of the polyamide-based resin, a thermoplastic elastomer is added so as to have a mixing ratio of 0.5 wt% or more and less than 8.0 wt%, and the polymetaxylylene The first sample within 2 m from the end of winding of the film in which the thermoplastic elastomer is not added in the resin layer B mainly composed of adipamide or is added at a mixing ratio of less than 0.5% by weight When the cutout portion is provided, and the final cutout portion is provided within 2 m from the beginning of winding of the film, and the sample cutout portion is provided every 100 m ± 1 m from the first sample cutout portion,
(2) For each sample cut out from each cutout section, when measuring the maximum boiling water shrinkage rate, which is the maximum value among the boiling water shrinkage rates in all directions, an average that is the average value of the maximum boiling water shrinkage rates The boiling water shrinkage is 2% to 6%, and the variation rate of the maximum boiling water shrinkage of all the samples is within a range of ± 2% to ± 20% with respect to the average boiling water shrinkage (3) For each sample cut out from each cut-out part, the boiling water shrinkage direction difference, which is the absolute value of the difference between the boiling water shrinkage rate in the +45 degree direction with respect to the longitudinal direction and the boiling water shrinkage ratio in the −45 degree direction with respect to the longitudinal direction, is obtained. The average boiling water shrinkage direction difference, which is the average value of the boiling water shrinkage direction differences, is 3.0% or less, and the variation rate of the boiling water shrinkage direction difference of all the samples is the average boiling water shrinkage. Within ± 5% to ± 30% of the rate direction difference There (4) fluctuation index in the thickness over the entire length in the longitudinal direction of the wound roll is in the range of from ± 2% ~ ± 15% relative to the average thickness The polyamide-based mixed resin laminated film roll according to claim 1, wherein the polyamide-based mixed resin laminated film satisfies the following formula (I).
Pa <1 / [t (0.015x + 0.15)] (I)
(Where x is the content (% by weight) of polymetaxylylene adipamide in the film, Pa is the average oxygen permeability (ml / m ² · MPa · day) of the film at a temperature of 23 ° C. and a relative humidity of 65%, t represents the thickness (mm) of the film.) For each sample cut out from each cut-out part, when the oxygen permeability was determined, the average oxygen permeability, which is the average value of those oxygen permeability, was 140 ml / m ² · MPa · day or less, and all 3. The polyamide-based mixed resin laminated film according to claim 1, wherein a variation rate of oxygen permeability of the sample is within a range of ± 2% to ± 20% with respect to the average oxygen permeability. roll. 3. The polyamide-based mixed resin laminated film roll according to claim 1, wherein each sample cut out from each cut-out portion satisfies the following requirement (5) and the following requirement (6).
(5) When measuring the three-dimensional surface roughness in the winding direction, the average surface roughness, which is the average value of the three-dimensional surface roughness, is in the range of 0.01 to 0.06 μm, and all The variation rate of the three-dimensional surface roughness of the sample is in the range of ± 5% to ± 20% with respect to the average surface roughness. (6) When haze is measured, the average value of those hazes A certain average haze is in the range of 2.0% to 7.0%, and the haze variation rate of all the samples is in the range of ± 2% to ± 15% with respect to the average haze. For each sample cut out from each cutout portion, the content of the thermoplastic elastomer component was measured, and when calculating the average content rate that is the average value of those content rates, the thermoplastic elastomer component of all the samples The polyamide based mixed resin laminated film roll according to claim 1 or 2 , wherein a variation rate of the content is within a range of ± 10% with respect to the average content. For each sample cut out from each cut-out part, when the tensile elastic modulus in the winding direction of the film was measured, the average tensile elastic modulus, which is the average value of the tensile elastic modulus, was 1.7 GPa or more and less than 3.1 GPa The polyamide-based mixed resin laminate according to claim 1 or 2 , wherein the variation rate of the tensile elastic modulus of all the samples is within a range of ± 10% with respect to the average tensile elastic modulus. Film roll. Pinholes when each sample cut out from each cut-out part is subjected to a bending test of 500 cycles continuously at a rate of 40 cycles per minute using a gelbo flex tester in an atmosphere of 5 ° C. The polyamide-based mixed resin laminated film roll according to claim 1 or 2 , wherein the number of each is 10 or less. When the refractive index in the thickness direction was measured for each sample cut out from each cutout portion, the average refractive index, which is the average value of those refractive indexes, was 1.500 or more and 1.520 or less, and all samples 3. The polyamide-based mixed resin laminated film roll according to claim 1, wherein a variation rate of the refractive index of the polyamide is within a range of ± 2% with respect to the average refractive index. 3. The polyamide-based mixed resin laminated film roll according to claim 1, wherein a main component of polyamide contained in the wound polyamide-based mixed resin laminated film is nylon 6. The polyamide-based mixed resin laminated film roll according to claim 1 or 2 , wherein the wound polyamide-based mixed resin laminated film is laminated with a polyolefin-based resin film. The molten raw material resin is extruded from a T-die, brought into contact with a metal roll and cooled, and a polyamide-based mixed resin laminated film obtained by biaxially stretching an unoriented sheet is obtained. The polyamide-based mixed resin laminated film roll according to claim 1 or 2 . The polyamide-based mixed resin laminated film roll according to claim 1 or 2 , wherein the polyamide-based mixed resin laminated film is wound up by a tenter stretching method. The polyamide-based mixed resin laminated film roll according to claim 1 or 2 , wherein the polyamide-based mixed resin laminated film wound up sequentially biaxially is wound. The polyamide-based mixed resin laminated film roll according to claim 1 or 2 , wherein the polyamide-based mixed resin laminated film stretched biaxially in the vertical direction and the horizontal direction is wound up. A sheet material made of a substantially unoriented resin is stretched in the longitudinal direction in at least two stages so as to obtain a magnification of 3 times or more at a temperature higher than the glass transition temperature of the resin + 20 ° C. The polyamide-based mixed resin laminated film roll according to claim 1 or 2 , wherein the polyamide-based mixed resin laminated film rolled up in the transverse direction so as to have the above magnification is wound up. The polyamide-based mixed resin laminated film roll according to claim 1 or 2 , wherein the polyamide-based mixed resin laminated film that has been heat-set after the final stretching treatment is wound. The polyamide-based mixed resin laminated film roll according to claim 1 or 2 , wherein the polyamide-based mixed resin laminated film which has been subjected to relaxation treatment after being heat-set is wound up. At least one of a lubricant, an antiblocking agent, a heat stabilizer, an antioxidant, an antistatic agent, a light resistance agent, and an impact resistance improving agent is added to the wound polyamide-based mixed resin laminated film. The polyamide-based mixed resin laminated film roll according to claim 1 or 2 . The polyamide-based mixed resin laminated film roll according to claim 1 or 2 , wherein inorganic particles are added to the wound polyamide-based mixed resin laminated film. The polyamide-based mixed resin laminated film roll according to claim 19 , wherein the inorganic particles are silica particles having an average particle diameter of 0.5 to 5.0 μm. The polyamide-based mixed resin laminated film roll according to claim 1 or 2 , wherein a higher fatty acid is added to the wound polyamide-based mixed resin laminated film. A production method for producing the polyamide-based mixed resin laminated film roll according to claim 1 or 2 ,
A raw resin is melt-extruded from a plurality of extruders by a co-extrusion method, whereby a resin layer B mainly composed of polymetaxylylene adipamide and a resin layer A mainly composed of a polyamide-based resin are laminated. A film forming process for forming a stretched laminated sheet;
A biaxial stretching step of biaxially stretching the unstretched laminated sheet obtained in the film-forming step in the machine direction and the transverse direction,
The manufacturing method of the polyamide-type mixed resin laminated | multilayer film roll characterized by satisfy | filling the following requirements (a)-(e).
(A) Moisture ratio immediately before supplying the resin to the extruder for forming the resin layer B mainly composed of polymetaxylylene adipamide and the resin layer A mainly composed of polyamide. (B) The biaxial stretching step is stretched in two stages in the longitudinal direction and then in the transverse direction, and the difference from the moisture content immediately before being supplied to the resin extruder for forming the resin is adjusted to 100 ppm or more. (C) the film-forming step is a plurality of extruders, and the film forming step is a plurality of extruders. Each of the resin chips to be used is melt-extruded after mixing at least one of the resin chips having the largest amount of use with one or more other resin chips different from the resin chips. The shape is an elliptical cylinder having an elliptical cross section having a major axis and a minor axis, and resin chips other than the resin chip having the largest amount used are the average major axis, the minor minor axis and the resin chip having the largest amount used. The average chip length is adjusted to have an average major axis, an average minor axis, and an average chip length that are included within a range of ± 20%, respectively. And a melt extrusion process using a plurality of extruders provided with a funnel-shaped hopper, and all the inclination angles of the funnel-shaped hopper are adjusted to 65 degrees or more, and are supplied to the funnel-shaped hopper The temperature of each resin chip before being adjusted is adjusted to 80 ° C. or higher. (E) In the film forming step, the molten resin extruded in a laminated state is wound around a cooling roll. In the cooling process, the portion that contacts the surface of the molten resin and the cooling roll is sucked in the opposite direction to the winding direction by the suction device over the entire width of the molten resin. To be done A preheating step that is performed before the longitudinal stretching step, and a heat treatment step that is performed after the longitudinal stretching step,
The fluctuation range of the surface temperature of the film at an arbitrary point in the longitudinal stretching step, the preheating step, and the heat treatment step is adjusted within a range of an average temperature ± 1 ° C. over the entire length of the film. The manufacturing method of the polyamide type mixed resin laminated | multilayer film roll of Claim 22 .