JP5548376B2 - Resin film for transverse stretching containing 4-methylpentene-1 (co) polymer and method for producing the same - Google Patents

Description

  The present invention relates to a resin film for transverse stretching containing 4-methylpentene-1 (co) polymer.

  The 4-methylpentene-1 (co) polymer is excellent in transparency and the like. Therefore, there has been a demand for a transparent and excellent stretched film containing 4-methylpentene-1 (co) polymer. However, 4-methylpentene-1 (co) polymer has a unique crystal structure and is easily crystallized. In addition, a 4-methylpentene-1 (co) polymer film has a relatively small elongation at break, and therefore, it is difficult to form a uniform stretched film because it tends to cause uneven stretching or break easily. It was.

  In order to overcome these drawbacks, it has been proposed to simultaneously biaxially stretch a film of 4-methylpentene-1 (co) polymer (see, for example, Patent Document 1). It has also been proposed that the melted resin film is rapidly cooled to produce an original film for stretching, thereby reducing the crystallinity of the film and improving the stretchability of the original film for stretching. However, in the prior art, even with a rapidly cooled raw material for stretching, the uniformity of the film when stretched laterally, particularly the uniformity of the film during transverse stretching at a low magnification, was insufficient. Therefore, in order to obtain a uniform stretched film, it is necessary to further perform longitudinal stretching after transverse stretching, or to set the transverse stretching ratio higher than the longitudinal stretching ratio (for example, 5 times) (for example, , See Patent Document 2).

JP 58-185226 A JP 61-228932 A

  Lateral stretching is suitable for producing a stretched film that is less likely to be damaged on the roll as compared to longitudinal stretching and has excellent surface properties. Moreover, in a specific use, since it is necessary to set the orientation direction by extending | stretching and the longitudinal direction of a film to a specific angle, the lateral stretched film was calculated | required. However, as described above, in the 4-methylpentene-1 (co) polymer film, it has been difficult to uniformly carry out low uniaxial transverse uniaxial stretching. It was necessary to stretch at a magnification. Since only a thin stretched film can be obtained when stretched at a high magnification, a thick and uniform transverse uniaxially stretched film could not be obtained. In addition, no production method has been proposed that can precisely control the properties by the draw ratio, the draw temperature, and the like.

  Accordingly, an object of the present invention is to provide a resin film for transverse stretching, which is a resin film containing 4-methylpentene-1 (co) polymer and can be subjected to transverse uniaxial stretching at a low magnification. .

  As a result of intensive studies, the inventors have found that an extruded film having a specific intrinsic viscosity that has a low ratio of the crystalline phase and the intermediate phase and a high ratio of the amorphous phase can be used as a raw material for transverse stretching. It has been found that uniform transverse stretching at a magnification is possible. In addition, the inventors have found that this lateral stretch original fabric can be uniformly stretched at a low magnification even when the film thickness is large, and have reached the present invention.

That is, the first of the present invention relates to a resin film for transverse stretching shown below and a method for producing the same.
<1>: A resin film for transverse stretching containing 4-methylpentene-1 (co) polymer, having a film thickness of 65 μm or more and 250 μm or less, and an intrinsic viscosity [η] of 0.5 dl / g or more. A resin film for transverse stretching which is 1 dl / g or less and does not have a tensile yield point in the transverse direction at 160 ° C. and 190 ° C.

<2>: The resin film for transverse stretching according to <1>, wherein the 4-methylpentene-1 (co) polymer contains 3% by weight or more of a repeating unit derived from an α-olefin having 8 or more carbon atoms. .
<3>: A method for producing a resin film for transverse stretching according to <1> or <2>, wherein (1) a resin composition containing 4-methylpentene-1 (co) polymer is melted from a die A step of extruding, (2) a step of fixing the extruded body obtained in the step to a cooling roll of 5 ° C. or higher and 25 ° C. or lower by an electrostatic adhesion method, and (3) the cooling of the extruded body. A process for producing a resin film for transverse stretching, comprising a step of cooling and solidifying on a roll.
<4>: A method for producing a resin film for transverse stretching according to <1> or <2>, wherein (1) a resin composition containing 4-methylpentene-1 (co) polymer is melted from a die A step of extruding, (2) a step of allowing the extruded body obtained in the step to enter between a plurality of opposing cooling rolls of 5 ° C. or higher and 30 ° C. or lower, and (3) the extruded body being the cooling roll. The manufacturing method of the resin film for transverse stretch which has the process solidified by cooling between.

The second aspect of the present invention relates to the following laterally stretched film and a method for producing the film.
<5>: A resin film containing 4-methylpentene-1 (co) polymer, having a film thickness of 13 μm or more and 227 μm or less, and a thermal dimensional change at 160 ° C. measured by the TMA method in the TD direction − A transversely stretched resin film that is 50 to 0% and 0 to 5% in the MD direction.

<6>: A method for producing a laterally stretched resin film according to <5>, wherein (4) the laterally stretched resin film according to <1> or <2> is at a temperature of 160 ° C. or higher and 190 ° C. or lower. Manufacturing a laterally stretched resin film comprising: a step of stretching in the TD direction at a draw ratio of 1.1 to 5 times, and (5) a step of heat setting the stretched film obtained in the step (4) Method.
<7>: The method for producing a laterally stretched resin film according to <6>, wherein the resin film for lateral stretching is obtained by the production method according to <3> or <4>.

  According to the present invention, a resin film containing 4-methylpentene-1 (co) polymer stretched laterally and uniaxially at a low magnification is obtained. That is, the laterally stretched film containing the 4-methylpentene-1 (co) polymer of the present invention is a laterally stretched film that is suppressed in necking when stretched in the lateral direction and has a uniform thickness over a wide range of stretch ratios. Can be provided. Therefore, the film for transverse stretching of the present invention can uniformly and easily perform transverse uniaxial stretching at a low magnification; and even if it is a resin film thicker than before, the transverse uniaxial stretching at a low magnification is uniform. Can be done.

  Thus, according to the present invention, a film of 4-methylpentene-1 (co) polymer having a desired stretching ratio in a wide range can be obtained, and has a high practical value.

  The present invention relates to a laterally stretched resin film (transversely stretched resin film) and a laterally stretched resin film (laterally stretched resin film), but in any case includes 4-methylpentene-1 (co) polymer. It relates to a resin film.

  The 4-methylpentene-1 (co) polymer contained in the laterally stretched resin film or the laterally stretched resin film of the present invention only needs to have a repeating unit derived from 4-methylpentene-1. There are no other restrictions. That is, the 4-methylpentene-1 (co) polymer may be a homopolymer of 4-methylpentene-1 or a copolymer with other monomers. The content of the structural unit derived from 4-methyl-pentene-1 in the 4-methyl-pentene-1 (co) polymer is usually 85 mol% or more, preferably 90 mol% or more.

  The copolymerization component with 4-methyl-pentene-1 in the 4-methyl-pentene-1 (co) polymer may be any monomer copolymerizable with 4-methyl-pentene-1. The monomer copolymerizable with 4-methyl-pentene-1 is preferably exemplified by ethylene or an α-olefin having 3 to 20 carbon atoms from the viewpoint of easy availability and copolymerization characteristics. Examples of α-olefins having 3 to 20 carbon atoms include propylene, 1-butene, 1-hexene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, -Eikosen is included. Among these, from the viewpoint of “obtaining a uniformly stretchable resin film” which is one of the problems of the present invention, as a preferable copolymer component, α- having 8 or more, preferably 10 or more, more preferably 12 or more carbon atoms. Examples include olefins.

  The content of the structural unit derived from the copolymer component in the 4-methyl-pentene-1 (co) polymer is usually 3% by weight or more, preferably 4% by weight or more, and more preferably 5% by weight. That's it.

  The melt flow rate (MFR) of 4-methyl-pentene-1 (co) polymer measured according to ASTM D1238 under conditions of a load of 5 kg and a temperature of 260 ° C. is usually about 1 to 400 g / 10 minutes. The range is preferably 2 to 200 g / 10 min, and more preferably 5 to 100 g / 10 min, but it may be set as appropriate depending on the use of the horizontally stretched film. When the melt flow rate of 4-methyl-pentene-1 (co) polymer is within the above range, the moldability of the resin film and the appearance of the stretched resin film are improved.

  The melting point of 4-methyl-pentene-1 (co) polymer is usually 100 to 240 ° C., preferably 150 to 240 ° C.

  The 4-methyl-pentene-1 (co) polymer can be produced by a conventionally known method. For example, as described in JP-A-59-206418, 4-methyl-pentene-1 (co) polymer is produced in the presence of a catalyst. It can be obtained by (co) polymerizing -pentene-1 and, if necessary, ethylene or α-olefin.

  The intrinsic viscosity of the 4-methyl-pentene-1 (co) polymer is preferably 1.0 to 4.5 dL / g, but is not necessarily a necessary requirement. On the other hand, as described later, since the intrinsic viscosity of the resin film for transverse stretching of the present invention is an important requirement, 4-methyl-pentene-1 ( It is preferable to set the intrinsic viscosity of the (co) polymer.

  The laterally stretched resin film or laterally stretched resin film of the present invention contains various additives in addition to the 4-methyl-pentene-1 (co) polymer as long as the object of the present invention is not impaired. Also good. Examples of various additives include plasticizers. Examples of the plasticizer include paraffinic, naphthenic, and aromatic mineral oils; oligomers of α-olefins, co-oligomers; ester plasticizers; various vegetable oils; animal oils, and the like. Such a plasticizer can further improve the moldability during stretching of the resin film for transverse stretching.

  Further, the laterally stretched resin film or laterally stretched resin film of the present invention may contain other resins in addition to the 4-methyl-pentene-1 (co) polymer. Examples of other resins include polyolefins, polyamides, polyesters and the like.

  Furthermore, the resin film for lateral stretching or the laterally stretched resin film of the present invention includes various compounds used by adding to ordinary polyolefins, such as a weather resistance stabilizer, a heat resistance stabilizer, a slip agent, a nucleating agent, a pigment, and a dye. An agent can be added within a range not impairing the object of the present invention.

About resin films for transverse stretching:
The resin film for transverse stretching of the present invention has 1) a film thickness of 65 μm or more and 250 μm or less, 2) an intrinsic viscosity [η] of 0.5 dl / g or more and 2.1 dl / g or less, 3) 160 It is characterized by having no tensile yield point in the transverse direction in a temperature range of from 0C to 190C.

  The film thickness of the resin film for lateral stretching of the present invention is 65 μm or more and 250 μm or less, preferably 70 to 220 μm, more preferably 75 to 200 μm. This is because when the thickness of the resin film for transverse stretching is within this range, a stretched film having a thickness of about 13 to 227 μm that is frequently used in practice can be obtained by stretching at a desired stretching ratio. The desired draw ratio is usually 1.1 to 5 times, preferably 1.1 to 4 times, and more preferably 1.5 to 3 times. This is because a stretched film having a draw ratio of 1.1 to 5 can appropriately control its mechanical properties and optical properties.

  The resin film for transverse stretching of the present invention is characterized in that its intrinsic viscosity [η] is 0.5 dl / g or more and 2.1 dl / g or less. This is because the resin film having the intrinsic viscosity [η] in this range does not have an excessive ratio of crystal phase and intermediate phase (without excessively high crystallinity) and can achieve uniform transverse stretching.

  In order to suppress the improvement of the crystallinity of the resin, conventionally, by increasing the molecular weight of the polymer constituting the resin (that is, increasing the MFR of the resin or increasing the intrinsic viscosity [η]). It was considered effective to slow down the crystallization. On the other hand, since the resin film for transverse stretching of the present invention is composed of a 4-methyl-pentene-1 (co) polymer having a relatively low molecular weight, its intrinsic viscosity is relatively low. Nevertheless, the resin film for transverse stretching of the present invention is surprisingly capable of uniform transverse stretching.

  The resin film for transverse stretching of the present invention does not have a tensile yield point in the transverse direction at 160 ° C and 190 ° C. Therefore, necking hardly occurs in the transverse stretching, and uniform transverse stretching can be performed even at a low stretching ratio. Furthermore, in order to perform uniform stretching more easily, it is preferable that there is no tensile yield point in the machine direction (MD).

  The stretching film that does not have a tensile yield point in the transverse direction can be realized, for example, by increasing the degree of amorphousness of the stretching film. The preferred degree of non-crystallinity of the stretchable film varies depending on the molecular parameters and the production method, and cannot be specified unconditionally, but is usually 37% or more, preferably 39% or more, more preferably 41% or more, and further preferably 45% or more. .

  In particular, when a stretched film is obtained by cooling a melt-extruded film from one side, the degree of non-crystallinity is preferably 41% or more; when a stretched film is obtained by cooling from both sides, the degree of amorphousness is obtained. Is preferably 37% or more. The degree of non-crystallinity of the film used was a stretching film cut to a sample amount equivalent to about 5 mg, in a nitrogen stream of 50 ml / min, between −80 ° C. and 300 ° C., a heating rate of 2 ° C./min, and a modulation period of 60 sec. Determined by DSC measurement with modulation amplitude ± 1 ° C.

  The stretching film that does not have a tensile yield point in the transverse direction can also be realized by increasing the degree of amorphousness of the raw material resin. Although the preferred degree of amorphousness of the raw material resin varies depending on the molecular parameters and the production method and cannot be generally specified, it is usually 50% or more, preferably 55% or more, more preferably 60% or more, and even more preferably 65% or more.

  The amorphous degree of the raw material resin is measured on a sample obtained by melting a 2 mg sample (the calculated film thickness in the sample pan is 122 μm) at 320 ° C. and then rapidly cooling with liquid nitrogen. In addition, when the non-crystallinity of the raw material resin is less than 50%, it is highly likely that the cooling rate in actual molding will result in a film with necking. Alternatively, it is preferable to take a process for increasing the cooling rate.

  The resin film for transverse stretching of the present invention preferably has a breaking elongation at 160 ° C. of 600% or more, and more preferably 700% or more. Further, the elongation at break at 190 ° C. is preferably 400% or more, and more preferably 500% or more. When the elongation at break satisfies the above requirements, the occurrence of breakage due to local non-uniformity is effectively suppressed, and stretching at a high magnification of about 5 times can be stably performed. In order to increase the elongation at break, it is preferable to increase the intrinsic viscosity as much as possible within the range of 0.5 dl / g to 2.1 dl / g.

  Furthermore, the resin film for transverse stretching of the present invention preferably has a haze of 5% or less. If the haze is 5% or less, it is easy to reduce the haze of the horizontally stretched film. A film having a low haze can be used as a packaging film having an excellent appearance or an optical film having a small optical loss.

  The resin film for transverse stretching of the present invention is produced by an arbitrary method, and the production method is not particularly limited. For example, a resin composition containing 4-methyl-pentene-1 (co) polymer and an arbitrary material can be obtained by film forming, for example, by melt extrusion or melt casting. Among these, a preferable production method can be the following (a) or (b).

(Production method a):
(1) a step of melt-extruding a resin composition containing 4-methylpentene-1 (co) polymer from a die, (2) a chill roll having an extrudate obtained by the step of 5 ° C. or more and 25 ° C. or less And (3) a step of cooling and solidifying the object to be extruded on the cooling roll.

  According to the manufacturing method a, the resin film which is an extruded body is rapidly cooled on the cooling roll. Therefore, the ratio of the amorphous part in a resin film improves. A resin film having a high proportion of amorphous portions can be more easily stretched uniformly. The film thickness of the resin film produced by the production method a is preferably 65 μm or more and 100 μm or less. This is because the resin film is efficiently cooled by the cooling roll.

In addition, it is preferable that an additive and / or a filler is added to the resin composition (before extrusion) in the production method a in order to impart ion conductivity at the time of electrostatic adhesion. It is preferable to set the AC volume resistivity of the molten resin of 1 × 10 ⁸ to 1 × 10 ¹² Ω · cm (measured at 20 ° C./HZ at 10 ° C./min and measured after 4 minutes). This is because the resin film, which is an object to be extruded, is fixed to the cooling roll with good adhesion by the electrostatic adhesion method. The electrostatic contact method refers to a method in which an electrostatic charge is applied to one side of a film and the sheet is brought into close contact with a cooling roll with this electrostatic force.

(Production method b):
(1) a step of melt-extruding a resin composition containing 4-methylpentene-1 (co) polymer from a die, and (2) an object to be extruded obtained by the above step facing at a temperature of 5 ° C. to 30 ° C. And (3) a step of cooling and solidifying the extruded body between the cooling rolls.

  According to the manufacturing method b, the resin film which is a to-be-extruded body is cooled, narrowing between several cooling rolls. Therefore, a resin film having a relatively large film thickness is also easily cooled, the ratio of the amorphous portion is increased, and uniform stretching is facilitated. As described above, the film thickness of the resin film for transverse stretching of the present invention is preferably 65 μm or more and 250 μm or less. However, in the case of producing a resin film for transverse stretching having a relatively large film thickness, the production method b Is preferably adopted.

  Of the plurality of cooling rolls for narrowing the resin film, the cast roll is preferably a metal cast roll; and the touch roll may be a flexible roll or a sleeve touch roll having a flexible thin metal outer cylinder. preferable.

For laterally stretched resin films:
The transversely stretched resin film (laterally stretched resin film) of the present invention has 1) a film thickness of 13 μm or more and 227 μm or less, and 2) a thermal dimensional change at 160 ° C. measured by the TMA method is −50 in the TD direction. ˜0%, and 0˜5% in the MD direction.

  The transversely stretched resin film of the present invention can be set to a desired film thickness depending on its use. The use of the laterally stretched resin film is not particularly limited, and can be applied to various uses such as packaging, medical use, optical use, and electric and electronic use. In order to apply to these uses, it is usually preferable that the film thickness is 13 μm or more and 227 μm or less.

  It is preferable that the thermal dimensional change in the MD direction of the transversely stretched resin film of the present invention is small. Specifically, the thermal dimensional change in the MD direction at 160 ° C. measured by the TMA method under conditions of a heating rate of 5 ° C./min, a sample size of 3 mm width, and a measurement load of 9.8 mN is usually + 5% or less. Yes, preferably + 3% or less, more preferably + 1% or less. The change in the thermal dimension in the MD direction is controlled by stretching conditions, heat setting conditions, and the like.

  When the thermal dimensional change is + 5% or less, film wrinkles during high temperature use can be prevented, and mechanical properties and optical properties are stabilized even when used for a long time at high temperatures. Therefore, it is particularly suitable when mounted on a small electric / electronic device, in-vehicle device or the like. On the other hand, the thermal dimensional change in the TD direction is also appropriately adjusted depending on the application.

  The mechanical properties at 23 ° C. of the transversely stretched resin film of the present invention are preferably such that the breaking strength is 20 MPa or more, the tensile elastic modulus is 500 MPa or more, and the breaking elongation is 50% or more in both the MD direction and the TD direction. When the above requirements are satisfied, breakage during use is effectively suppressed, and it is particularly suitable for use in places where stress is applied.

  The haze of the laterally stretched resin film of the present invention is desirably 4% or less. If the haze is 4% or less, it can be used as a packaging film having excellent appearance or an optical film having a small optical loss.

  Since the above-mentioned resin film for transverse stretching hardly causes necking stretching when transversely stretched, a laterally stretched resin film having a film thickness distribution almost corresponding to the film thickness distribution of the resin film for lateral stretching is obtained. Can do. Therefore, by increasing the thickness uniformity of the resin film for lateral stretching, the uniformity of the film thickness of the laterally stretched resin film can be increased.

  The laterally stretched resin film of the present invention is not particularly limited in its production method as long as the predetermined material, film thickness, and thermal dimensional change satisfy predetermined conditions. For example, it can be obtained by transversely stretching the above-mentioned resin film for transverse stretching, and can be produced by the following (Production Method c).

(Production method c):
(4) a step of stretching the above-described resin film for transverse stretching in a TD direction at a stretching temperature of 160 ° C. to 190 ° C. at a stretching ratio of 1.1 times to 5 times; and (5) the step ( It has the process of heat-setting the stretched film obtained by 4).

  The resin film for transverse stretching used in the production method c may be a resin film produced by the above (a production method) or (b production method).

  If the stretching temperature is too low, necking stretching may occur; if necking stretching occurs, the film thickness of the stretched film may become uneven, which is not preferable. On the other hand, if the stretching temperature is too high, a predetermined stretching ratio cannot be obtained, and the film thickness distribution may be increased, which is not preferable.

  When the draw ratio is too low, it is not preferable because the haze of the horizontally stretched resin film or the thermal expansion coefficient cannot be reduced and the mechanical properties are hardly improved.

  Hereinafter, the present invention will be described in more detail with reference to examples. However, the scope of the present invention is not limited by this.

  Table 1 shows 4-methylpentene-1 (co) polymers used in each Example and Comparative Example. Is the 4-methylpentene-1 (co) polymer shown in Table 1 a homopolymer of 4-methylpentene-1 (raw materials No 1 and 2); 4-methylpentene-1 and decene-1 A copolymer of 4-methylpentene-1 and a mixture of 1-dodecene and 1-tetradecene (raw material No5); 4-methylpentene-1 And a hexadecene / octadecene mixture (raw materials No. 6 to 10). The copolymer is a random copolymer, and the content of the copolymer component is as shown in Table 1.

  The properties of 4-methylpentene-1 (co) polymer are shown in Table 1. Each characteristic was evaluated by the following method unless otherwise specified.

  (1) Intrinsic viscosity [η]: measured at 135 ° C. in a decalin solvent.

(2) Crystallinity Xc: measured by DSC method.
Q2000 (manufactured by TA Instruments) was used as a measuring device. Powdered or pelleted raw material was used as a measurement sample, melted at 320 ° C., cooled and solidified with liquid nitrogen, and then heated at a rate of 10 ° C./min between −80 ° C. and 300 ° C. in a nitrogen flow of 50 ml / min. DSC measurement was performed. The sample amount was about 2 mg (the calculated film thickness in the sample pan was 122 μm) and about 5 mg (the calculated film thickness in the sample pan was 305 μm).

  The amount of heat of fusion ΔH was read from the obtained measurement chart. Assuming that the heat of crystal melting of the complete crystalline product of the homopolymer of 4-methylpentene-1 is 118.35 J / g, it is applied to the calculation formula of “crystallinity Xc (%) = ΔH / 118.35 × 100”. The crystallinity Xc (%) was determined.

(3) Amorphization degree Xa: measured by a temperature modulation DSC method.
As with the degree of crystallinity, Q2000 (manufactured by TA Instruments) was used as the measuring apparatus. A raw material in the form of powder or pellets was used as a measurement sample, melted at 320 ° C., cooled and solidified with liquid nitrogen, and then heated at a rate of 2 ° C./min between −80 ° C. and 300 ° C. in a 50 ml / min nitrogen stream. DSC measurement was performed at a modulation period of 60 sec and a modulation amplitude of ± 1 ° C. The sample amount was about 2 mg (the calculated film thickness in the sample pan was 122 μm) and about 5 mg (the calculated film thickness in the sample pan was 305 μm).

  From the reversible component, the center temperature (Tg) of the glass transition temperature and the specific heat difference (ΔCp) at Tg were read. Assuming that the specific heat difference of the completely amorphous material of the homopolymer of 4-methylpentene-1 is 0.400 J / g ° C., the calculation formula of “amorphization degree Xa (%) = ΔCp / 0.400 × 100” By applying, the degree of non-crystallinity Xa (%) was determined.

  In each example and comparative example, a melt-extruded film was prepared using the 4-methylpentene-1 (co) polymer (raw materials No. 1 to 11) shown in Table 1; Thus, a stretched film was obtained. The physical properties of the melt-extruded film and stretched film were evaluated by the following methods.

  (1) Film thickness: The film for stretching and the film thickness of the stretched film were measured at 1 cm intervals using a TOMA-4R thickness meter manufactured by YMABUN, and the average of the measured values was obtained.

  (2) Haze of film: The film for stretching and the haze of the stretched film were measured in accordance with JIS K7105-1981 using Tokyo Denshoku automatic haze meter MODEL: Tc-HIIIDRK.

  (3) Intrinsic viscosity [η] of the film and degree of amorphousness of the film: It was determined by the same method as that for 4-methylpentene-1 (co) polymer.

  (4) Tensile test: The tensile test was performed using an RTG-1250 manufactured by Orientec, a tensile tester with a thermostatic bath, at each measurement temperature (130 ° C, 160 ° C, 190 ° C), a sample width of 5 mm, a chuck interval of 30 mm, The presence / absence of a tensile yield point and the tensile breaking elongation (TD breaking elongation%) were measured under the condition of a test speed of 30 mm / min. The TD breaking elongation was measured at n = 3 and the average value (%) was taken.

  (5) Stretchability: When stretched at 160 ° C., the case where necking stretching did not occur was marked with “◯”; the case where necking stretching occurred was marked with “x”.

  (6) Stretch ratio: The stretch ratio was set as the stretch ratio set for a continuous clip tenter type horizontal stretcher or the stretch ratio set for a batch stretcher (manufactured by Iwamoto Seisakusho).

  (7) Appearance of stretched film: “◎” when there is no defect observed visually within the range of 50 cm length, and when some defects due to entrainment of bubbles are visually observed but no cloudiness is observed Was marked with “◯”, and “X” when the surface was visually cloudy or the surface was uneven due to melt fracture.

  (8) Thermal dimensional change: The thermal dimensional change was measured by the TMA method under the conditions of a temperature increase rate of 5 ° C./min, a sample size of 3 mm width, a chuck interval of 10 mm, and a measurement load of 9.8 mN. +) Or thermal shrinkage (-) was measured. As a device, TMA / SS6000 manufactured by Seiko Instruments Inc. was used.

[Example 1]
The 4-methylpentene-1 (co) polymer of raw material No. 7 in Table 1 was used as the resin raw material.
100 parts by weight of a raw material 7 (resin powder particles having a melting point of 226.7 ° C. and a diameter of about 200 μm) was mixed with tetrakis [methylene-3 (3,5-di-tert-butyl-4) as a heat-resistant stabilizer. -Hydroxyphenyl) propionate] Methane (manufactured by Ciba Geigy Co., Ltd., trade name: Irganox 1010) 0.89 part by weight, and calcium stearate 0.3 part by weight were added. The obtained resin composition was replaced with nitrogen under reduced pressure, and then supplied to a twin-screw extruder (manufactured by Nippon Steel Works: TEX65α-42BPW) under a nitrogen stream. The extrusion temperature was 250 ° C, the die temperature was 300 ° C, and the extrusion amount. Extrusion was performed from a T die having a width of 1170 mm and a lip distance of 0.5 mm at 30 kg / hr.

  The extruded resin was immediately solidified on a cast roll cooled to a roll temperature of 25 ° C. by an electrostatic adhesion method, and wound up at a take-up speed of 16.5 m / min. The thickness of the produced film was 84 μm on average in the TD direction. The intrinsic viscosity of the film was 1.9 dl / g.

  The obtained film was introduced into a clip tenter-type transverse stretching machine (manufactured by Nippon Steel Works, Ltd.) as a stretched original fabric (stretching film), and the temperature of the preheating zone, stretching zone, and heat treatment zone was 160 ° C., TD A transversely stretched film was obtained by stretching twice in the direction.

[Comparative Example 1]
A stretched film was obtained in the same manner as in Example 1 except that the take-up speed was 12.0 m / min.

[Example 2]
A stretched film was obtained in the same manner as in Example 1 except that the amount of calcium stearate added was 0.1 parts by weight.

[Comparative Example 2]
A stretched film was obtained in the same manner as in Example 2 except that the resin raw material was changed to the raw material 8 in Table 1.

[Examples 3 and 4]
Using the resin raw material as the raw material 9 in Table 1, a stretched raw material having a film thickness of 70 μm and a film thickness of 65 μm was obtained. The obtained stretched original fabric was stretched in the same manner as in Example 1 to obtain a stretched film.

[Example 5]
A stretched film was obtained in the same manner as in Example 2 except that the resin raw material was changed to the raw material 10 in Table 1.

[Comparative Example 3]
A stretched film was obtained in the same manner as in Example 1 except that the resin raw material was a blend of raw material 6 and raw material 7 shown in Table 1 (ratio: 50 wt% / 50 wt%) and the take-up speed was 16.5 m / min. .

[Comparative Example 4]
A stretched film was obtained in the same manner as in Example 1 except that the resin raw material was the raw material 6 in Table 1, the extrusion temperature was 300 ° C., the width was 350 mm, the lip distance was 1.1 mm, and the take-up speed was 10 m / min.

  Table 2 shows the properties of the laterally stretched film and the laterally stretched film obtained in each Example and Comparative Example. “* 1” in Table 2 means that thinning was difficult; “* 2” means that MD elongation at break was 700%; “* 3” It means that the blend ratio of the raw material 7 is 50 wt% / 50 wt%.

[Example 6]
The raw material 11 in the form of pellets was extruded from a T-die having a width of 700 mm and a gap between lips of 0.5 mm at an extrusion temperature of 310 ° C. and an extrusion rate of 90 kg / hr using a 90 mmφ single-screw extruder. The extruded resin was immediately solidified between a flexible roll and a cast roll cooled to about 15 to 20 ° C., and taken up at a take-up speed of 15.0 m / min.

  The resulting film is used as a stretch fabric and introduced into a clip tenter-type transverse stretching machine (manufactured by Nippon Steel Works), and the preheating zone, stretching zone, and heat treatment zone are stretched twice in the TD direction at a temperature of 160 ° C. did. Table 3 shows the properties of the obtained laterally stretched film.

[Examples 7 and 8]
The pellet-shaped raw material 5 was used, extruded with a 40 mmφ single screw extruder at an extrusion temperature of 320 ° C., a sleeve touch roll (manufactured by Chiba Machine Industries), a cast roll and a sleeve touch roll were set at 15 ° C., and 135 μm ( Films of Example 7) and 200 μm (Example 8) were obtained.

  The obtained film was stretched and heat set with a batch stretching machine manufactured by Iwamoto Seisakusho. Preheating temperature 160 ° C., preheating time 3 minutes, stretching temperature 160 ° C., stretching speed 10 mm / sec, stretching direction TD direction. Heat setting was performed for 3 minutes after the temperature in the tank was raised by 5 ° C. while being chucked.

[Comparative Examples 5 and 6]
The pellet-shaped raw material 5 was used, extruded with a 40 mmφ single screw extruder at an extrusion temperature of 320 ° C., and brought into close contact with a roll set at 40 ° C. by an electrostatic contact method, 200 μm (Comparative Example 5) and 80 μm. A film of (Comparative Example 6) was obtained. A stretched film was obtained in the same manner as in Example 6 using the obtained film as a stretched original fabric.

[Comparative Example 7]
It was carried out in the same manner as in Comparative Example 4 except that it was molded between 300 mmφ metal rolls and the take-up speed was 7 m / min. A stretched film was obtained in the same manner as in Example 6 using the obtained film as a stretched original fabric.

  Table 3 shows the properties of the laterally stretched film and the laterally stretched film obtained in each Example and Comparative Example. “* 4” in Table 3 means that the film was stretched by a batch type stretching machine.

  According to the present invention, the lateral uniaxial stretching of a resin film containing 4-methylpentene-1 (co) polymer can be uniformly performed at a low magnification. Moreover, according to the present invention, the lateral uniaxial stretching of the resin film thicker than before can be performed uniformly at a low magnification. Therefore, a resin film having a desired stretch ratio in a wide range can be obtained.

  The transversely stretched film of the present invention is excellent in uniformity and flexibility in stretch ratio (film thickness), and therefore used for various applications in a wide range of industrial fields such as packaging, medical use, optics use, and electrical and electronic parts. Can do.

Claims (4)

A 4-methylpentene-1 copolymer containing 3% by weight or more of a repeating unit derived from an α-olefin having 8 or more carbon atoms, a film thickness of 65 μm to 95 μm, and an intrinsic viscosity [η] of 0 A method of producing a resin film for transverse stretching that is not less than 5 dl / g and not more than 2.1 dl / g and does not have a tensile yield point in the transverse direction at 160 ° C. and 190 ° C .;
(1) A step of melt-extruding a resin composition containing 4-methylpentene-1 copolymer from a die,
(2) A step of fixing the extruded body obtained in the above step to a cooling roll of 5 ° C. or higher and 25 ° C. or lower by an electrostatic adhesion method, and (3) cooling the extruded body on the cooling roll. A method for producing a resin film for transverse stretching, comprising a step of solidifying. A 4-methylpentene-1 copolymer containing 3% by weight or more of a repeating unit derived from an α-olefin having 8 or more carbon atoms, a film thickness of 65 μm to 200 μm, and an intrinsic viscosity [η] of 0 A method of producing a resin film for transverse stretching that is not less than 5 dl / g and not more than 2.1 dl / g and does not have a tensile yield point in the transverse direction at 160 ° C. and 190 ° C .;
(1) A step of melt-extruding a resin composition containing 4-methylpentene-1 copolymer from a die,
(2) A step of allowing the extruded body obtained in the above step to enter between a plurality of opposed cooling rolls of 5 ° C. or higher and 30 ° C. or lower, and (3) cooling and solidifying the extruded body between the cooling rolls. A process for producing a resin film for transverse stretching, comprising: A resin film obtained by transversely stretching a resin film for transverse stretching obtained by the method for producing a resin film for transverse stretching according to claim 1 or 2,
A transversely stretched resin film having a thermal dimensional change at 160 ° C. measured by the TMA method of −50 to 0% in the TD direction and 0 to 5% in the MD direction. It is a manufacturing method of the transverse stretch resin film according to claim 3,
(4) Stretching the resin film for lateral stretching in the TD direction at a stretching ratio of 1.1 times or more and 5 times or less at a temperature of 160 ° C. or more and 190 ° C. or less; and (5) In the step (4) The manufacturing method of the transverse stretch resin film which has the process of heat-setting the obtained stretched film.