JP2010083019A - Method of continuously manufacturing master roll film supplied to hollow-containing resin molding, device of continuously manufacturing master roll film supplied to hollow-containing resin molding, master roll film supplied to hollow-containing resin molding, method of manufacturing hollow-containing resin molding using this master roll film, and hollow-containing resin molding - Google Patents

Abstract

[PROBLEMS] To provide a continuous production of a raw film for use in a void-containing resin molded article capable of efficiently obtaining a raw film that is highly suitable for performing the next steps such as winding and stretching without increasing the haze value due to crystallization. Method, production apparatus for continuous raw film of raw film to be provided for void-containing resin molded body, raw film to be provided for void-containing resin molded body, and method for producing void-containing resin molded body using the raw film and Provision of void-containing resin moldings.
A method of continuously producing a raw film for use in a void-containing resin molded article is obtained by hot-melt extruding a polymer composition containing a crystalline polymer, cooling the extruded polymer composition 205, and unstretching. It includes an extrusion molding process for molding the polymer molded body 206, and a cutting process for cutting at least a portion of the unstretched polymer molded body 206 having a haze value of 25% or more.
[Selection] Figure 1

Description

  The present invention relates to a continuous production method of a raw film to be provided for a void-containing resin molded article, a continuous production apparatus for the raw film to be provided for a void-containing resin molded article, a raw film to be provided for a void-containing resin molded article, and the raw The present invention relates to a method for producing a void-containing resin molded body using a film and a void-containing resin molded body.

Polybutylene terephthalate, which is a crystalline polymer, has excellent mechanical strength, heat resistance, chemical resistance, impact resistance, and electrical properties. It is used for injection molding products such as parts.
Moreover, the manufacturing method of the polybutylene terephthalate film excellent in the uniformity of film thickness and the heat-resistant shrinkage suitable as various packaging materials is proposed (for example, refer patent document 1). In Patent Document 1, a molten polybutylene terephthalate resin was extruded from a T die into a film, and the obtained film was gradually cooled in an unstretched state to crystallize the polybutylene terephthalate resin. The film is stretched.

However, the unstretched film obtained by the manufacturing method described in Patent Document 1 is crystallized so that all or part of the unstretched film is hard. However, there is a problem that the work becomes difficult. In particular, the portion where the haze value has increased due to crystallization is hardened and brittle, and handling becomes difficult.
That is, in order to wind a cured film, a large winding force is required, so that it is very difficult to wind, and when part of the film is crystallized and the haze value is increased, Since only the resin is cured, there is a problem that wrinkles are generated during winding and defective winding occurs.
In addition, when handling and bending the film by passing the film over the roll, fine cracks are likely to occur, especially in the part where the haze value is increased due to crystallization, and the haze value at the end part is particularly increased. If there is, there is a problem that fine cracks enter here and the film breaks from this portion.
Furthermore, in order to stretch the cured film, since a large stretching force is required, stretching is difficult, and when a stretching force is applied to a film that is partially crystallized and has an increased haze value, There is a problem that the film cannot be stretched uniformly and the film is torn or the tension is non-uniform at the torn part, which causes wrinkles over a large area of the film.

Further, in order to obtain a void-containing resin molded product using the film, it is preferable to stretch the film at a desired stretching temperature. For example, the film to be stretched has a haze value of 25% or more. If there is a crystallized portion to be shown, there is a problem that the film easily tears from this crystallized portion, and it is particularly important to cope with a portion where the crystallized portion has increased in haze value.
Also in the transverse stretching apparatus, when the film edge is gripped with a clip, the film cracks due to the gripping pressure and tension of the clip, and the film breaks starting from this point. However, it may become a big trouble to get damaged by the windshield in the device.

  Moreover, although the method of cutting off the bad part of a film by trimming is disclosed (for example, refer patent document 2), this method is a method of solving the problem about shape | molding an amorphous resin, and crystallinity. The present condition is that there is nothing which solves the said problem about a polymer, especially the thing which solves the said problem regarding manufacture of a void containing resin molding.

International Publication No. 04/048071 Pamphlet JP 2007-276273 A

  An object of the present invention is to solve the conventional problems and achieve the following objects. That is, the present invention provides an original film for use in a void-containing resin molded article that can efficiently obtain an original film that is extremely suitable for performing the next steps such as winding and stretching without increasing the haze value due to crystallization. A continuous production method of the present invention, an apparatus for producing a continuous raw film of a raw film to be provided for a void-containing resin molded article, an original fabric film to be provided for a void-containing resin molded article, and a void-containing resin molded article using the raw film It aims at providing a manufacturing method and a cavity containing resin molding.

Means for solving the above problems are as follows. That is,
<1> An extrusion molding process in which a polymer composition containing a crystalline polymer is hot melt extruded, the extruded polymer composition is cooled to form an unstretched polymer molded body,
And a cutting step in which at least a portion having a haze value of 25% or more of the unstretched polymer molded body is excised.
<2> The method for continuously producing a raw film for use in the void-containing resin molded product according to <1>, further including a haze value detection step of detecting a haze value of the unstretched polymer molded product.
<3> A raw material to be provided to the void-containing resin molded product according to any one of <1> to <2>, further including a winding step of winding the raw film from which at least a portion having a haze value of 25% or more has been cut. This is a continuous production method for an anti-film.
<4> The method for continuously producing an original film for use in the void-containing resin molded product according to any one of <1> to <3>, wherein the original film is amorphous.
<5> The method for continuously producing a raw film for use in the void-containing resin molded product according to any one of <1> to <4>, wherein the polymer having crystallinity contains polybutylene terephthalate.
<6> Extruding means for hot-melt extruding a polymer composition containing a crystalline polymer, cooling the extruded polymer composition to form an unstretched polymer molded body,
And a cutting means for cutting at least a portion having a haze value of 25% or more of the unstretched polymer molded body.
<7> A continuous production apparatus for a raw film for use in the void-containing resin molded article according to <6>, further including a haze value detecting means for detecting a haze value of the unstretched polymer molded article.
<8> The raw material to be provided to the void-containing resin molded article according to any one of <6> to <7>, further including a winding means for winding the raw film from which a portion having a haze value of 25% or more has been cut off. This is an anti-film continuous production apparatus.
<9> A raw film for use in a void-containing resin molded article produced by the method for continuously producing a raw film according to any one of <1> to <5>.
<10> A stretching step of stretching a raw film produced by a continuous production method of a raw film to be provided for the void-containing resin molded article according to any one of <1> to <5>. It is a manufacturing method of a cavity containing resin molding.
<11> A cavity obtained by stretching a raw film produced by a continuous production method of a raw film provided to the void-containing resin molded article according to any one of <1> to <5> It is a containing resin molding.

  According to the present invention, various problems in the prior art can be solved, the above object can be achieved, and a highly suitable raw film can be efficiently used for the next process such as winding and stretching without increasing the haze value due to crystallization. Method for continuously producing a raw film to be provided for a void-containing resin molded body, an apparatus for producing a continuous raw film for a raw film to be provided for a void-containing resin molded body, and an original film for a void-containing resin molded body In addition, it is possible to provide a method for producing a void-containing resin molded body using the raw film and a void-containing resin molded body.

(Manufacturing method of raw film used for void-containing resin molding)
The manufacturing method of the raw film used for the void-containing resin molded article of the present invention includes at least an extrusion molding process and a cutting process, and includes other processes as necessary.

<Extrusion process>
The extrusion molding step is a step in which a polymer composition containing a polymer having crystallinity is subjected to hot melt extrusion, and the extruded polymer composition is cooled to form an unstretched polymer molded body.

-Polymer composition-
The polymer composition includes a polymer having crystallinity and, if necessary, includes other components.
When the raw film is used for the void-containing resin molded product of the present invention to be described later, the polymer composition preferably does not contain a component that contributes to the development of voids as the other component. It is particularly preferred that no components are included.

-Polymer with crystallinity-
Generally, polymers are divided into polymers having crystallinity and amorphous (amorphous) polymers, but even polymers having crystallinity are not 100% crystallized, and the main structure of molecules in each other's molecular structure. It includes a crystalline region in which chains and side chains are regularly arranged and an amorphous region that is not regularly arranged.
Therefore, the polymer having crystallinity in the unstretched polymer molded body may include at least the crystalline region in the molecular structure, and the crystalline region and the amorphous region may be mixed.

  There is no restriction | limiting in particular as said polymer which has crystallinity, According to the objective, it can select suitably, For example, high density polyethylene, polyolefins (for example, polypropylene, polyethylene, ethylene-vinyl acetate copolymer, ethylene- Vinyl alcohol copolymer, ethylene-cycloolefin copolymer, polybutene-1, poly-4-methylpentene-1, etc.), polyamides (PA) (for example, nylon-6), polyacetals (POM), polyesters (For example, PET, PEN, PTT, PBT, PPT, PHT, PBN, PES, PBS, etc.), syndiotactic polystyrene (SPS), polyphenylene sulfides (PPS), polyether ether ketones (PEEK), liquid crystal polymer (LCP), fluororesin And the like. Among these, polyesters, syndiotactic polystyrene (SPS), and liquid crystal polymers (LCP) are preferable, polyesters are more preferable, and polybutylene terephthalate is particularly preferable from the viewpoints of mechanical strength and ease of manufacture. Two or more of these polymers may be blended or copolymerized.

The melt viscosity of the crystalline polymer is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably 50 Pa · s to 700 Pa · s, more preferably 70 Pa · s to 500 Pa · s, 80 Pa · s to 300 Pa · s is particularly preferable. When the melt viscosity is 50 Pa · s to 700 Pa · s, it is preferable in that the shape of the film of the polymer composition extruded from the T-die in the molding step described later is stable and easy to form (mold) uniformly. . Further, when the melt viscosity is 50 Pa · s to 700 Pa · s, the viscosity in the molding process described later becomes appropriate and the extrusion becomes easy, and the film of the polymer composition at the time of film formation is leveled to reduce unevenness. It is preferable in that it can be made.
Here, the melt viscosity can be measured by a plate type or cone type rheometer or capillary rheometer.

There is no restriction | limiting in particular as intrinsic viscosity (IV) of the polymer which has the said crystallinity, Although it can select suitably according to the objective, 0.4-1.4 are preferable and 0.6-1.2 are More preferred is 0.7 to 1.0. When the IV is 0.4 to 1.4, the strength of the formed film (unstretched polymer molded body) is increased, and this is preferable in that the film can be efficiently stretched.
Here, the IV can be measured by an Ubbelohde viscometer.

There is no restriction | limiting in particular as melting | fusing point (Tm) of the polymer which has the said crystallinity, Although it can select suitably according to the objective, 100 to 350 degreeC is preferable, 100 to 300 degreeC is more preferable, 100 degreeC ˜260 ° C. is particularly preferred. The melting point is preferably 40 ° C. to 350 ° C. in that it is easy to keep the shape in the temperature range expected for normal use, and even without using special techniques required for processing at high temperatures, It is preferable at the point which can form a uniform film.
Here, the melting point can be measured by a differential thermal analyzer (DSC).

--- Polyester resin ---
The polyesters (hereinafter sometimes referred to as “polyester resin”) mean a general term for polymer compounds having an ester bond as the main bond chain. Therefore, as the polyester resin suitable as the polymer having crystallinity, the exemplified PET (polyethylene terephthalate), PEN (polyethylene naphthalate), PTT (polytrimethylene terephthalate), PBT (polybutylene terephthalate), PPT ( Polycondensation of polypentamethylene terephthalate), PHT (polyhexamethylene terephthalate), PBN (polybutylene naphthalate), PES (polyethylene succinate), PBS (polybutylene succinate), dicarboxylic acid component and diol component All polymer compounds obtained by the reaction are included.

  The dicarboxylic acid component is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include aromatic dicarboxylic acids, aliphatic dicarboxylic acids, alicyclic dicarboxylic acids, oxycarboxylic acids, and polyfunctional acids. Among them, aromatic dicarboxylic acids are preferable.

  Examples of the aromatic dicarboxylic acid include terephthalic acid, isophthalic acid, diphenyldicarboxylic acid, diphenylsulfone dicarboxylic acid, naphthalenedicarboxylic acid, diphenoxyethanedicarboxylic acid, and 5-sodium sulfoisophthalic acid. Acid, diphenyldicarboxylic acid, and naphthalenedicarboxylic acid are preferable, and terephthalic acid, diphenyldicarboxylic acid, and naphthalenedicarboxylic acid are more preferable.

  Examples of the aliphatic dicarboxylic acid include oxalic acid, succinic acid, eicoic acid, adipic acid, sebacic acid, dimer acid, dodecanedioic acid, maleic acid, and fumaric acid. Examples of the alicyclic dicarboxylic acid include cyclohexane dicarboxylic acid. Examples of the oxycarboxylic acid include p-oxybenzoic acid. Examples of the polyfunctional acid include trimellitic acid and pyromellitic acid. Among the aliphatic dicarboxylic acids and alicyclic dicarboxylic acids, succinic acid, adipic acid, and cyclohexanedicarboxylic acid are preferable, and succinic acid and adipic acid are more preferable.

  The diol component is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include aliphatic diols, alicyclic diols, aromatic diols, diethylene glycol, and polyalkylene glycols. Group diols are preferred.

  Examples of the aliphatic diol include ethylene glycol, propane diol, butane diol, pentane diol, hexane diol, neopentyl glycol, and triethylene glycol. Among them, propane diol, butane diol, pentane diol, and hexane diol are exemplified. Particularly preferred. Examples of the alicyclic diol include cyclohexanedimethanol. Examples of the aromatic diol include bisphenol A and bisphenol S.

  There is no restriction | limiting in particular as melt viscosity of the said polyester resin, Although it can select suitably according to the objective, 50 Pa.s-700 Pa.s are preferable, 70 Pa.s-500 Pa.s are more preferable, 80 Pa.s ˜300 Pa · s is particularly preferred. When the melt viscosity is higher, voids are more likely to appear during stretching, which will be described later. This is preferable in that it becomes difficult and the quality is stabilized. Further, the melt viscosity of 50 Pa · s to 700 Pa · s is preferable in that the drawing tension is appropriately maintained at the time of drawing, which will be described later, and it becomes easy to draw uniformly and is difficult to break. Further, when the melt viscosity is 50 Pa · s to 700 Pa · s, the shape of the molten film discharged from the die head at the time of film formation can be easily maintained, and it can be stably molded or the product is hardly damaged. It is preferable in terms of improving physical properties.

  There is no restriction | limiting in particular as intrinsic viscosity (IV) of the said polyester resin, Although it can select suitably according to the objective, 0.4-1.2 are preferable, 0.6-1.0 are more preferable, 0.7 to 0.9 is particularly preferable. When the IV is larger, voids are more likely to occur during stretching, which will be described later. However, when the IV is 0.4 to 1.2, it is easy to extrude at the time of film formation, or the resin flow is stable and retention is difficult to occur. It is preferable in that the quality is stabilized. Furthermore, when the IV is 0.4 to 1.2, the stretching tension is appropriately maintained at the time of stretching, which will be described later. In addition, when the IV is 0.4 to 1.2, it is preferable in that the product is hardly damaged and the physical properties are increased.

  There is no restriction | limiting in particular as melting | fusing point of the said polyester resin, Although it can select suitably according to the objective, From viewpoints, such as heat resistance and film forming property, 150 to 300 degreeC is preferable, and 160 to 270 degreeC is preferable. More preferred.

  In addition, as said polyester resin, the said dicarboxylic acid component and the said diol component may each superpose | polymerize, and the polymer may be formed, and at least any one of the said dicarboxylic acid component and the said diol component is 2 types. A polymer may be formed by copolymerization as described above. Further, as the polyester resin, two or more kinds of polymers may be blended and used.

  In the blend of two or more polymers, the polymer added to the main polymer has a melt viscosity and an intrinsic viscosity that are close to those of the main polymer, and the addition amount is smaller when the film is formed or melted. It is preferable in that the physical properties are enhanced during extrusion and the extrusion becomes easy.

  In addition, for the purpose of improving the flow characteristics of the polyester resin, controlling the light transmittance, and improving the adhesion with the coating solution, a resin other than the polyester resin may be added to the polyester resin.

---- Polyolefin resin ---
The polyolefins (hereinafter referred to as “polyolefin resins”) mean polymers obtained by polymerizing α-olefins based on ethylene. As the polyolefin resin suitable as the polymer having the crystallinity, as described above, for example, polypropylene, polyethylene, ethylene-vinyl acetate copolymer, ethylene-vinyl alcohol copolymer, ethylene-cycloolefin copolymer, Polybutene-1, poly-4-methylpentene-1, etc. are mentioned. Among these, polyethylene and polypropylene are more preferable, and polypropylene is particularly preferable.

  There is no restriction | limiting in particular as melt viscosity of the said polyolefin resin, Although it can select suitably according to the objective, 50 Pa.s-700 Pa.s are preferable, 70 Pa.s-500 Pa.s are more preferable, 80 Pa.s ˜300 Pa · s is particularly preferred. When the melt viscosity is higher, voids are more likely to appear during stretching, which will be described later. This is preferable in that it becomes difficult and the quality is stabilized. Further, the melt viscosity of 50 Pa · s to 700 Pa · s is preferable in that the drawing tension is appropriately maintained at the time of drawing, which will be described later, and it becomes easy to draw uniformly and is difficult to break. Further, when the melt viscosity is 50 Pa · s to 700 Pa · s, the shape of the molten film discharged from the die head at the time of film formation can be easily maintained, and it can be stably molded or the product is hardly damaged. It is preferable in terms of improving physical properties.

Further, as the polyolefin resin, those copolymerized with different kinds of resins may be used, or two or more kinds of polymers may be blended and used.
In the blend of two or more polymers, the polymer added to the main polymer has a melt viscosity and an intrinsic viscosity that are close to those of the main polymer, and the addition amount is smaller when the film is formed or melted. It is preferable in that the physical properties are enhanced during extrusion and the extrusion becomes easy.
In addition, for the purpose of improving the flow characteristics of the polyolefin resin, controlling the light transmittance, and improving the adhesion with the coating solution, a resin other than the polyolefin resin may be added to the polyolefin resin.

-Other ingredients-
The other component is not particularly limited as long as it does not impair the effects of the present invention, and can be appropriately selected according to the purpose. The unstretched polymer molded body of the present invention, which will be described later, is described below. When used in the above, the other components are preferably components that do not contribute to the development of cavities.

  Examples of the component that does not contribute to the development of the cavity include a heat stabilizer, an antioxidant, an organic lubricant, a nucleating agent, a dye, a pigment, a dispersing agent, a coupling agent, and a fluorescent brightening agent. Whether or not the other component contributed to the development of the cavity can be determined by whether or not a component other than the polymer having crystallinity (for example, each component described later) is detected in the cavity or at the interface portion of the cavity. .

There is no restriction | limiting in particular as said antioxidant, According to the objective, it can select suitably, For example, well-known hindered phenols etc. are mentioned. Examples of the hindered phenols include antioxidants commercially available under trade names such as Irganox 1010, Similarizer BHT, and Similarizer GA-80.
Further, the antioxidant can be used as a primary antioxidant and further combined with a secondary antioxidant. Examples of the secondary antioxidant include antioxidants commercially available under trade names such as Sumilizer TPL-R, Sumilizer TPM, Sumilizer TP-D, and the like.

  The fluorescent whitening agent is not particularly limited and may be appropriately selected depending on the intended purpose. For example, commercially available products with names such as Ubitech, OB-1, TBO, Keicoal, Kayalite, Leukopua, EGM, etc. Can be used. In addition, the said fluorescent whitening agent may be used individually by 1 type, and may use 2 or more types together. By adding the fluorescent whitening agent in this way, it is possible to give a brighter and more bluish whiteness and to have a high-class feeling.

-Melting and kneading (thermal melting)-
As a method for obtaining a polymer composition containing the polymer having crystallinity, there is a method of melt-kneading two or more kinds of polymers. The method for melt kneading is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include a method for melt kneading in a twin screw extruder, a method for melt kneading in a single screw extruder, and the like. . When melt kneading is performed in the extruder, it is necessary to adjust the temperature appropriately so that the polymer does not deteriorate due to heat generated during kneading. It is preferable to use one having a screw structure that does not knead more than necessary or one having an appropriate cooling device.
The temperature of the melt-kneading is not particularly limited and may be appropriately selected depending on the intended purpose. The melting point of the crystalline polymer is + 10 ° C to the melting point of the crystalline polymer + 50 ° C, preferably The melting point of the crystalline polymer + 20 ° C. to the melting point of the crystalline polymer + 40 ° C. is more preferred, and the melting point of the crystalline polymer + 15 ° C. to the melting point of the crystalline polymer + 25 ° C. is particularly preferred.
If the temperature of the melt kneading is less than the melting point of the crystalline polymer + 10 ° C., the kneading may be insufficient and the extrusion amount may become unstable, and the melting point of the crystalline polymer + 50 ° C. If it exceeds, thermal degradation of the polymer having crystallinity may proceed. On the other hand, when the temperature of the melt kneading is within the particularly preferable range, it is advantageous in that the kneading is sufficiently performed and at the same time the thermal deterioration of the polymer is suppressed.
For example, when a homopolymer polybutylene terephthalate (PBT) resin is used as the crystalline polymer, the melting point of the resin is about 225 ° C., and therefore the temperature of the melt kneading is preferably 240 ° C. to 250 ° C. . The melting point can be measured by a test method such as ASTM D4591.

-Extrude-
The extrusion method is not particularly limited and may be appropriately selected depending on the intended purpose. For example, a method of extruding the melt-kneaded polymer composition from a die directly from an extruder or via another extruder There is a method of once cooling and pelletizing and then extruding from a die again through an extruder.

There is no restriction | limiting in particular as said die | dye, According to the objective, it can select suitably, For example, as a flat die, Keiji Sawada "Plastic extrusion molding and its application" (Seibundo Shinko Co., Ltd.) And T-die, fishtail die, coat hanger die and the like. Among these, a T die is preferable.
There is no restriction | limiting in particular as a gap of the said die | dye, According to the objective, it can select suitably, For example, it can be 3 mm or less. Moreover, it is preferable to provide a mechanism for adjusting the width of the gap as needed along the longitudinal direction of the die in order to adjust the thickness of the film-like or sheet-like molded product to be melt extruded.
There is no restriction | limiting in particular as the quantity of the said polymer composition extruded from the said die, According to the thickness of the target unstretched polymer molded object, it can select suitably.

The temperature of the polymer composition extruded from the die is not particularly limited and may be appropriately selected depending on the intended purpose. From the melting point of the crystalline polymer to the melting point of the crystalline polymer + 50 ° C. The melting point of the crystalline polymer is preferably + 40 ° C. from the melting point of the crystalline polymer, and the melting point of the crystalline polymer + 10 ° C. to the melting point of the crystalline polymer + 30 ° C. is particularly preferable.
When the temperature of the polymer composition extruded from the die is lower than the melting point of the polymer having crystallinity, the polymer cannot be sufficiently melted, kneading may be insufficient, or extrusion may become unstable, When the melting point of the crystalline polymer exceeds + 50 ° C., thermal degradation of the polymer proceeds, and molecular weight may be reduced, gel may be generated, or coloring may occur. On the other hand, when the temperature of the polymer composition extruded from the die is within the particularly preferable range, it is advantageous in that stable extrusion is performed and polymer deterioration is suppressed at the same time.

-Molding process-
The molding step is a step of molding the unstretched polymer molded body by cooling, preferably quenching, the extruded polymer composition.

-Cooling-
The cooling is performed in a substantially unstretched state of the extruded polymer composition. Thereby, an unstretched polymer molded object can be shape | molded, without crystallizing the said extruded polymer composition.
In the present invention, “substantially unstretched” means that the film has not been stretched in the stretching step.

There is no restriction | limiting in particular as a cooling rate of the said cooling, Although it can select suitably according to the objective, It is preferable to set it as 200 degreeC / second or more, It is more preferable to set it as 100 degreeC / second or more, 40 degreeC / Second or more is particularly preferable.
When the cooling rate of the cooling is less than 40 ° C./second, crystallization may progress during cooling and become brittle. On the other hand, when the cooling rate of the cooling is within the particularly preferable range, an original fabric having a low haze value and a low crystallinity can be produced, and when subjected to stretching, a cavity is stably formed. This is advantageous.

The cooling method is not particularly limited and may be appropriately selected depending on the purpose. For example, there is a method in which the extruded polymer composition is received by a casting drum (casting roll) and rapidly cooled by the casting drum. Can be mentioned.
There is no restriction | limiting in particular as temperature of the said casting drum, According to the objective, it can select suitably, -30 to 70 degreeC is preferable, 0 to 50 degreeC is more preferable, 10 to 40 degreeC is especially preferable. .
When the temperature of the casting drum is less than −30 ° C., it is difficult to prevent condensation of the casting drum, and the flatness of the raw film may be impaired. When the temperature exceeds 70 ° C., sufficient cooling can be performed. Therefore, a uniform original film may not be formed. On the other hand, when the temperature of the casting drum is within the particularly preferable range, it is advantageous in that a raw film having a small haze value in which crystallization is controlled and a void can be stably formed in a stretching process can be produced. .

The distance between the T die and the casting drum (referred to as an air gap) is not particularly limited and may be appropriately selected according to the purpose, but is preferably 10 cm to 1 cm, more preferably 5 cm to 1 cm, 3 cm to 2 cm is particularly preferable.
When the distance between the T-die and the casting drum is less than 1 cm, the molten polymer discharged from the die may flow so as to wrap around the edge of the die lip, whereby the molten polymer lands on the casting drum. May become unstable and a uniform film (film) may not be obtained, and if it exceeds 10 cm, a molten polymer film (called a sag film) from the die lip to the casting drum may flow around the die, The device itself is susceptible to the vibration of the device itself, and a uniform film may not be obtained. Especially when a polymer having a low melt viscosity is melt-extruded, the drooping film becomes unstable, and the drooping film splits into several stripes, or these streaky dripping films move from one end of the lip to the other. A uniform film such as [sway from side to side] may not be obtained. Furthermore, when the molten polymer is discharged downward from the die lip, the film may be stretched in the flow direction due to the weight of the hanging curtain, and unintended molecular orientation may progress to promote crystallization. On the other hand, when the distance between the T-die and the casting drum is within the particularly preferable range, it is advantageous in that the dripping film is stabilized, and as a result, the resulting film is likely to be uniform.

The peripheral speed of the casting drum is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably 1 m / min to 200 m / min, more preferably 5 m / min to 100 m / min, and 10 m / min. ˜50 m / min is particularly preferred.
When the peripheral speed of the casting drum is less than 1 m / min, uneven rotation of the drum due to the driving device of the casting drum appears remarkably. As a result, the polymer solidified on the casting drum has a thickness parallel to the die lip. Unevenness (called step unevenness) may occur, and if it exceeds 200 m / min, cooling of the molten polymer on the casting drum may be insufficient, and the film may not be peeled off from the casting drum. Similarly, since the cooling with the casting drum is insufficient, the crystallization of the film may not be controlled. On the other hand, when the peripheral speed of the casting drum is within the particularly preferable range, it is advantageous in that a film in which crystallization with uniform film thickness is sufficiently controlled can be manufactured.
Moreover, there is no restriction | limiting in particular as said casting drum diameter (diameter), Although it can select suitably according to the objective, 25 cm-300 cm are preferable, 100 cm-200 cm are more preferable, 100 cm-150 cm are especially preferable.
When the diameter of the casting drum is less than 25 cm, the film solidified on the casting drum has a small diameter wrinkle, and even if tension is applied, the film does not become flat, and the film guides in the processes after the casting drum. It may not be possible to pass smoothly through a roll or the like, film may be caught in the apparatus, or the tension of the line may become unstable due to film winding, and a uniform film may not be formed. Since it becomes difficult to cool the casting surface of the casting drum uniformly and stable cooling becomes difficult, unevenness may occur in the cast film. On the other hand, when the diameter of the casting drum is within the particularly preferable range, it is advantageous in that a uniform casting film can be formed, and handling is easy in the stretching process after casting, and uniform stretching is possible.
In addition, the said casting drum may be provided independently and may be provided with two or more. When a plurality of casting drums are provided, the peripheral speed of each casting drum is the same, but the temperature of each casting drum may be different.

-Unstretched polymer molded body-
There is no restriction | limiting in particular as a shape of the said unstretched polymer molded object obtained at the above-mentioned process, According to the objective, it can select suitably, For example, a film form, a sheet form, etc. are mentioned.

There is no restriction | limiting in particular as thickness of the said unstretched polymer molded object, Although it can select suitably according to the objective, 80 micrometers-2 mm are preferable, 150 micrometers-1 mm are more preferable, and 150 micrometers-500 micrometers are especially preferable.
When the thickness of the unstretched polymer molded body is less than 80 μm, voids may not be easily generated in the subsequent process. When the thickness exceeds 2 mm, the unstretched polymer molded body becomes rigid and wound. In some cases, handling may become difficult, and cooling on the casting drum may be insufficient, and the haze value may increase unexpectedly. On the other hand, when the thickness of the unstretched polymer molded product is within the particularly preferred range, it is advantageous in that it is easy to handle and the generation of voids in the subsequent process is performed stably.
In addition, the thickness of the said unstretched polymer molded object can be measured using the Keyence Corporation long range contact-type displacement meter AF030 (measurement part), AF350 (indication part).

<Resection process>
The excision step is a step of excising at least a portion having a haze value of 25% or more of the unstretched polymer molded body, and is a step of excising by an excision means described later.

-Haze value-
In the cutting step, at least a portion having a haze value of 25% or more is cut from the unstretched polymer molded body.
The portion to be excised is not particularly limited as long as at least a portion having a haze value of 25% or more is excised, and can be appropriately selected according to the purpose, but a portion having a haze value of 20% or more is excised. It is preferable that a portion having a haze value of 10% or more is excised.
When the haze value of the unstretched polymer molded body is opaque to 25% or more, it is difficult to wind, and wrinkles may occur during winding, which may cause winding failure. Further, it is difficult to stretch, and there is a risk of tearing during the stretching or causing wrinkles. Further, uniform and continuous generation of cavities (generation of voids) becomes difficult.

-Resection means-
The cutting means is not particularly limited as long as it can cut at least a portion where the haze value of the unstretched polymer molded body (extruded film) is 25% or more (hereinafter referred to as “whitened portion”). The longitudinal direction cutting means for cutting the unstretched polymer molded body that is extruded into a long shape in the longitudinal direction, and the short direction of the polymer molded body, for example, can be selected appropriately according to the purpose. A short direction excision means for excision can be used.
Further, as the excision means, the longitudinal direction excision means may be used alone, and further, the short direction excision means may be used in combination.

The longitudinal cutting means is not particularly limited and may be appropriately selected depending on the intended purpose.For example, a cemented carbide knife, a rotary cutter (Göbel slitter knife, score cutter, disk knife, etc.) A sonic cutter, a laser cutter, etc. are mentioned.
In the excision, it is desirable that the cut surface does not crack. Moreover, when melt-cutting a cutting part, it is preferable that the thickness of a cutting part does not become 5% or more thick.
When the longitudinal cutting means is used, a region including the whitened portion can be cut along the longitudinal direction (X direction in FIG. 4). The unstretched polymer molded product tends to whiten at both end sides (30 in FIG. 4) in the short direction (Y direction in FIG. 4). It can be used suitably. Further, when whitening occurs in the center portion in the short direction of the unstretched polymer molded body, the whitened portion can be cut out by a cutting means as exemplified in FIGS. 5 and 6A to 6E.

FIG. 5 is an explanatory diagram of an example of a traveling film cutting apparatus. A slide rail (X-axis direction rail 215) is provided in the X-axis direction parallel to the transport direction (long direction) of the original fabric 213, and Y can move on the slide rail in the flow direction and the reverse flow direction of the original fabric 213. An axial rail 214 is installed. The Y-axis direction rail 214 is equipped with a laser head 217 capable of moving on the rail from one end of the original fabric 213 to the other end, and the original fabric 213 is cut by a laser irradiated from the head. I can do it.
The laser head 217 uses either end of the original fabric 213 on the upstream side of the original fabric as a standby position, proceeds from this position along the flow of the original fabric 213 to the downstream side of the original fabric, and at the same time, the other end of the original fabric. The original fabric 213 can be cut in a direction perpendicular to the flow direction.
In this method, when the standby position of the laser head 217 is determined on one side of the original fabric 213 and an up / down mechanism (avoidance mechanism) is provided for the original surface of the head, an ultrasonic cutter or carbide is used instead of the laser head 217. A blade cutter or the like can also be used.

6A to 6E are explanatory diagrams of an example of a roller-type film cutting device. The metal roller 91 in which the cutter blade 92 is embedded is waiting at a position away from the original fabric 213 (see FIG. 6B). When the defect position approaches, the metal roller 91 starts to rotate (see FIG. 6C), and pushes the original fabric 213 in a form of sandwiching the presser roller 93 (see FIG. 6D). The metal roller 91 rotates as it is to the standby position (see FIG. 6E) and stops.
For the joining of the cut original fabric (base), for example, a technique such as Japanese Patent Application Laid-Open No. 2006-88147 “Ultrasonic joining horn and ultrasonic welding joining method” (Applicant Fuji Film Co., Ltd.) is applied. Can be used.

<Other processes>
There is no restriction | limiting in particular as said other process, Although it can select suitably according to the objective, It is preferable that a haze value detection process and a winding process are included.

-Haze value detection process-
The said haze value detection process is a process of detecting the haze value of an unstretched polymer molded object. There is no restriction | limiting in particular as a haze value detection means used for the process of detecting this haze value, According to the objective, it can select suitably. For example, an on-line spectral transmittance meter manufactured by NIRECO, an in-line film thickness transmittance spectrometer manufactured by Carl Zeiss, or the like can be used. Moreover, a haze value can be calculated | required by comparing the intensity | strength of the light emitted from the light source of a measuring device, and the light which permeate | transmitted this unstretched polymer molded object.

-Winding process (roll stock process)-
The winding step (roll stock step) is a step of temporarily winding a film from which at least a portion having a haze value of 25% or more has been excised.
There is no restriction | limiting in particular as a winding means used for this winding process, According to the objective, it can select suitably, For example, the winder by Kobayashi Seisakusho, the winding apparatus by Toshiba Machine, etc. are mentioned.

(Raw film used for void-containing resin moldings)
The raw film used for the void-containing resin molded body is a long film manufactured based on each of the above steps, and the unstretched polymer molded body has a haze value of 25% or more in a state where at least a portion has been cut off. It is a film.
The form of the raw film used for the cavity-containing resin molded body is not particularly limited as long as the film is in a state in which the above-mentioned part is cut off, and can be appropriately selected and used depending on the purpose. From the viewpoint of ease of winding on a roll and ease of manufacturing of a void-containing resin molded body described later, a sheet-like product formed into a film is preferable.
The raw film is preferably not whitened so that it can be preferably used for the production of a void-containing resin molded product to be described later.

(Manufacturing device for raw film used for void-containing resin molding)
An apparatus for producing an original film for use in a void-containing resin molded article is suitably used in the method for producing an original film, and heat-extrudes a polymer composition containing a crystalline polymer, and the extruded polymer composition Including at least an extrusion molding means for cooling an article to form an unstretched polymer molded body, and a cutting means for cutting at least a portion having a haze value of 25% or more of the unstretched polymer molded body, Haze value detecting means for detecting the haze value of the unstretched polymer molded body, and winding means for winding the raw film from which at least the portion having the detected haze value of 25% or more has been cut off.

  Each means of the extrusion molding means, cutting means, haze value detection means, and winding means is not particularly limited and can be appropriately selected according to the purpose. For example, the extrusion molding process, cutting process, haze value The means described in the detection step and the winding step can be applied.

  FIG. 1 shows an example of an apparatus for producing the above-described unstretched polymer molded article of the present invention. A polymer composition containing a melt-kneaded polymer having crystallinity is extruded from a T die 207. The extruded polymer composition 205 is rapidly cooled on the casting drum 201 to form an unstretched polymer molded body 206 without crystallization. The obtained unstretched polymer molded product is wound up by a take-up reel (not shown) through a guide roll 209.

FIG. 7 is an explanatory view of an outline of an example of an apparatus for producing the unstretched polymer molded body of the present invention. A polymer heated and melted at a predetermined temperature by a melt extrusion apparatus is discharged in a film form from a die head (not shown) connected to the melt extrusion apparatus onto a cooled casting drum (not shown). The film is formed into a cast film (also referred to as an original fabric or a sheet).
When the base (cast film) passes through the haze detection device, the haze is continuously measured, and the haze data is stored in a computer (not shown) as a set with the transport position of the base.
Based on this data, the base is cut by the cutting and feeding device.
When the cut part is at both ends of the base in the longitudinal direction, the base can be continuously conveyed, so that the base is passed through the take-up joining device without going through the roll stock device (winding process). It can be transported to the process after the accumulator.
If the cut part is spot-formed at the center of the base, the defective part cannot be removed unless the base is cut once, so the cut front end (the base just before the part where the defect starts) is The rear end (the base just after the portion where the defect is finished) waiting at the take-off joining device portion later is wound into a roll shape on the roll stock device side.
The cut front end waiting in the take-up joining device is stocked in the roll stock device, and the base tip is pulled out from the roll and joined.
For cutting the base, a cutting device as shown in FIG. 5 or FIGS. 6A to 6E can be used in combination.

  Although the said raw film of this invention can be used for various uses, it can be used especially suitably for the polymer resin molding film which consists of a cavity containing resin molding demonstrated below.

(Method for producing void-containing resin molded body and void-containing resin molded body)
<Method for producing void-containing resin molded article>
The method for producing a void-containing resin molded body of the present invention includes a step of stretching the above-described raw film of the present invention (stretching step), and further includes other steps such as a film forming step as necessary.
In addition, manufacture of the said void containing resin molded object may be performed independently with manufacture of the raw film of this invention mentioned above, and may be performed continuously.

-Stretching process-
In the stretching step, the raw film is stretched at least uniaxially. And by the said extending | stretching process, while a raw fabric film is extended | stretched, the cavity orientated along the 1st extending | stretching direction is formed in the inside, and a cavity containing resin molding is obtained.

The reason why the cavities are formed by stretching is that the polymer having at least one kind of crystallinity constituting the unstretched polymer molded body has regularity at a certain level of minute crystal regions or molecules by casting after melt extrusion. A minute region with a shape is formed. When this raw fabric is stretched around the glass transition temperature (Tg), it is peeled and stretched in such a way that the resin between phases including crystals or microstructure regions that are difficult to stretch is torn, and this becomes a cavity forming source. It is considered that a cavity is formed.
Such void formation by stretching is possible not only when there is only one kind of polymer having crystallinity but also when two or more kinds of polymers having crystallinity are blended or copolymerized. is there.

  The stretching method is not particularly limited as long as the effects of the present invention are not impaired, and examples thereof include uniaxial stretching, sequential biaxial stretching, and simultaneous biaxial stretching. It is preferable that longitudinal stretching is performed along the direction in which the molded body flows.

In general, in the longitudinal stretching, the number of longitudinal stretching stages and the stretching speed can be adjusted by the combination of rolls and the speed difference between the rolls.
The number of stages of longitudinal stretching is not particularly limited as long as it is one or more stages, but it can be more stably stretched at a high speed, and in view of production yield and machine restrictions, it is longitudinally stretched to two or more stages. It is preferable to do. Further, longitudinal stretching in two or more stages is advantageous in that a cavity can be formed by stretching in the second stage after confirming the occurrence of necking in the first stage.
In addition, the stretching conditions (for example, the stretching speed and the stretching temperature) in the second and subsequent stages may be the same as or different from the first stage.

-Stretching speed-
The stretching speed of the longitudinal stretching is not particularly limited as long as the effects of the present invention are not impaired, and can be appropriately selected according to the purpose, but is preferably 10 mm / min to 36,000 mm / min, and is preferably 800 mm / min. ˜24,000 mm / min is more preferable, and 1,200 mm / min to 12,000 mm / min is particularly preferable. When the stretching speed is 10 mm / min or more, it is preferable in that sufficient necking can be easily expressed. Further, when the stretching speed is 36,000 mm / min or less, uniform stretching is facilitated, the resin is not easily broken, and the cost is reduced without requiring a large stretching apparatus for high-speed stretching. It is preferable in that it can be performed. Therefore, when the stretching speed is 10 mm / min to 36,000 mm / min, sufficient necking is easily developed, uniform stretching is facilitated, the resin is not easily broken, and high speed stretching is intended. This is preferable in that the cost can be reduced without requiring a large stretching apparatus.

  More specifically, the stretching speed in the case of one-stage stretching is preferably 1,000 mm / min to 36,000 mm / min, more preferably 1,100 mm / min to 24,000 mm / min, and 1,200 mm / min. Min to 12,000 mm / min is particularly preferable.

  In the case of two-stage stretching, it is preferable that the first-stage stretching is a preliminary stretching whose main purpose is to develop necking. The stretching speed of the preliminary stretching is preferably 10 mm / min to 300 mm / min, more preferably 40 mm / min to 220 mm / min, and particularly preferably 70 mm / min to 150 mm / min.

  In the two-stage stretching, it is preferable that the second-stage stretching speed after the necking is expressed by the preliminary stretching (first-stage stretching) is changed from the preliminary stretching speed. The stretching speed of the second stage after causing necking by the preliminary stretching is preferably 600 mm / min to 36,000 mm / min, more preferably 800 mm / min to 24,000 mm / min, and 1,200 mm. / Min to 15,000 mm / min are particularly preferable.

There is no restriction | limiting in particular as a measuring method of the said extending | stretching speed, It can select suitably from well-known methods, For example, it can measure with the following method.
In the case of the batch type, the moving speed when the clamp holding the edge of the original film moves in the stretching direction, that is, the moving distance of the clamp / the time required for moving the clamp (mm / min) The stretching speed is used. The stretching speed defined in the present embodiment is the stretching speed in the batch type unless otherwise specified.

  Further, when the original film is stretched due to the difference in the surface speed of the nip roll when the original film passes two pairs (or more) of nip rolls (generally referred to as “Roll to Roll stretching”). The gripping position of the original film is fixed by a nip roll and does not move. Therefore, in the case of the above Roll to Roll stretching, the stretch ratio is the stretched ratio / the time required for stretching (% / min). The nip roll corresponds to the roll 15a in FIG.

  The stretching speed in the batch method and the stretching speed in the Roll to Roll stretching are the length before stretching (mm) and the length after stretching (mm) of the raw film in any stretching method. If they are measured, they can be converted into each other. Table 1 shows an example in which the stretching speed in the batch method is converted into the stretching speed in Roll to Roll stretching.

--Extension temperature--
The temperature during stretching is not particularly limited and can be appropriately selected according to the purpose.
When the stretching temperature is T (° C) and the glass transition temperature of the polymer having crystallinity is Tg (° C),
(Tg-30) (° C.) ≦ T (° C.) ≦ (Tg + 50) (° C.)
It is preferable to stretch at a stretching temperature T (° C.) in the range indicated by
(Tg-25) (° C.) ≦ T (° C.) ≦ (Tg + 50) (° C.)
It is more preferable to stretch at a stretching temperature T (° C.) in the range indicated by
(Tg-20) (° C.) ≦ T (° C.) ≦ (Tg + 50) (° C.)
It is particularly preferable to stretch at a stretching temperature T (° C.) in the range indicated by

  In general, the higher the stretching temperature (° C.), the lower the stretching tension and the easier the stretching, but the stretching temperature (° C.) is {glass transition temperature (Tg) −30} ° C. or higher, {glass transition temperature ( Tg) +50} ° C. or lower is preferable in that the void content increases, the aspect ratio tends to be 10 or more, and the voids are sufficiently developed.

  Here, the stretching temperature T (° C.) can be measured with a non-contact thermometer. The glass transition temperature Tg (° C.) can be measured by a differential thermal analyzer (DSC).

In the stretching step, lateral stretching may or may not be performed as long as it does not hinder the appearance of cavities. In the case of lateral stretching, the film may be relaxed or heat-treated using a lateral stretching process.
Further, the stretched void-containing resin molded body may be further subjected to treatment such as heat shrinkage by applying heat or applying tension for the purpose of shape stabilization.

FIG. 2 is a view showing an example of a method for producing a void-containing resin molded product of the present invention, and is a flow diagram of a biaxially stretched film production apparatus. The biaxially stretched film manufacturing apparatus shown in FIG. 2 is a film manufacturing apparatus that performs Roll to Roll stretching.
As shown in FIG. 2, the raw material resin (polymer composition) 11 is melted in the extruder 12 (a twin screw extruder or a single screw extruder is used depending on the raw material shape and production scale). After being kneaded, the T-die 13 is discharged into a soft plate shape (film or sheet shape).
Next, the discharged film or sheet F is cooled and solidified by the casting drum 14 to form a film. The formed film or sheet F (corresponding to “raw film”) is sent to the longitudinal stretching machine 15.
And the film or sheet | seat F formed into a film is again heated within the longitudinal stretch machine 15, and is stretched | stretched longitudinally between the rolls 15a from which speed differs. By this longitudinal stretching, a cavity is formed in the film or sheet F along the stretching direction. Then, the film or sheet F in which the cavity is formed is gripped at both ends by the left and right clips 16a of the transverse stretching machine 16, and is stretched laterally while being sent to the winder side (not shown). The resin molded body 1 is obtained. In addition, in the said process, you may use the film or sheet | seat F which performed only the longitudinal stretch as the cavity formation resin molding 1 without providing to the horizontal stretching machine 16. FIG. The void-containing resin molded body 1 is rolled through an expansion roll 17.

<Cavity-containing resin molding>
The void-containing resin molded body of the present invention can be obtained by the above-described method for producing a void-containing resin molded body.
There is no restriction | limiting in particular as a shape of the said void containing resin molding, According to the objective, it can select suitably, For example, a film form, a sheet form, a fiber form etc. are mentioned.

-Cavity-
The void-containing resin molded body of the present invention contains long cavities inside with the length direction oriented in one direction, and is characterized by the void content and the aspect ratio of the voids.
The cavity means a vacuum domain or a gas phase domain existing inside the resin molded body.

The void content means the total volume of the contained cavities relative to the sum of the total volume of the solid phase portion of the resin molded body and the total volume of the contained cavities.
The void content is not particularly limited as long as the effects of the present invention are not impaired, and can be appropriately selected according to the purpose, preferably 3% by volume or more and 50% by volume or less, and preferably 5% by volume to 40% by volume. % Is more preferable, and 10% by volume to 30% by volume is particularly preferable.
Here, the void content can be calculated based on the specific gravity by measuring the specific gravity.
Specifically, the void content can be obtained by the following equation (1).
Cavity content (%) = {1- (Density of cavity-containing resin molding after stretching) / (Density of unstretched polymer molding before stretching)} (1)

The aspect ratio refers to an average length of the cavity in the thickness direction orthogonal to the orientation direction of the cavity, r (μm), and an average length of the cavity in the orientation direction of the cavity, L (μm). L / r ratio is meant.
The aspect ratio is not particularly limited as long as the effects of the present invention are not impaired, and can be appropriately selected according to the purpose. The aspect ratio is preferably 10 or more, more preferably 15 or more, and particularly preferably 20 or more. .

  3A to 3C are diagrams for specifically explaining the aspect ratio, in which FIG. 3A is a perspective view of the void-containing resin molded body, and FIG. 3B is A of the void-containing resin molded body in FIG. 3A. -A 'sectional drawing, FIG. 3C is BB' sectional drawing of the cavity containing resin molding in FIG. 3A.

  In the manufacturing process of the void-containing resin molded body, the void is usually oriented along the first stretching direction. Therefore, the “average length of the cavity (r (μm)) in the thickness direction perpendicular to the orientation direction of the cavity” is perpendicular to the surface 1a of the cavity-containing resin molded body 1 and in the first stretching direction. This corresponds to the average thickness r (see FIG. 3B) of the cavity 100 in a cross section at right angles (cross section AA ′ in FIG. 3A). The “average length (L (μm)) of the cavity in the orientation direction of the cavity” is a cross section perpendicular to the surface of the cavity-containing resin molded body and parallel to the first stretching direction (FIG. This corresponds to the average length L (see FIG. 3C) of the cavity 100 in the BB ′ cross section in 3A.

In addition, said 1st extending | stretching direction shows the extending direction of 1 axis | shaft, when extending | stretching is only 1 axis | shaft. Usually, since longitudinal stretching is performed along the direction in which the molded body flows during production, this longitudinal stretching direction corresponds to the first stretching direction.
Moreover, when extending | stretching is biaxial or more, at least 1 direction is shown among the extending directions aiming at cavity formation. Usually, even in stretching with two or more axes, longitudinal stretching is performed along the flow direction of the molded body during production, and a cavity can be formed by this longitudinal stretching. It corresponds to the first stretching direction.

  Here, the average length (r (μm)) of the cavities in the thickness direction orthogonal to the orientation direction of the cavities can be measured by an image of an optical microscope or an electron microscope. Similarly, the average length (L (μm)) of the cavities in the alignment direction of the cavities can be measured by an image of an optical microscope or an electron microscope.

The void-containing resin molded product of the present invention is characterized by the average number P of cavities in the film thickness direction, the refractive index difference ΔN between the crystalline polymer layer and the cavity layer, and the product of the ΔN and the P. have.
The number of cavities in the film thickness direction refers to the film thickness direction in a cross section perpendicular to the surface 1a of the void-containing resin molded body 1 and perpendicular to the first stretching direction (AA ′ cross section in FIG. 3A). Means the number of cavities 100 included in
The average number P of cavities in the film thickness direction is not particularly limited as long as the effects of the present invention are not impaired, and can be appropriately selected according to the purpose, preferably 5 or more, more preferably 10 or more. Preferably, 15 or more are more preferable.
Here, the number of cavities in the film thickness direction can be measured by an image of an optical microscope or an electron microscope.

Specifically, the difference in refractive index ΔN between the crystalline polymer layer and the cavity layer is defined as N1 and N2 when the refractive index of the crystalline polymer layer is N1 and the refractive index of the cavity layer is N2. ΔN is the difference
It means the value of (= N1-N2).
Here, the refractive indexes N1 and N2 of the crystalline polymer layer and the cavity layer can be measured by an Abbe refractometer or the like.
The product of ΔN and P is not particularly limited as long as the effects of the present invention are not impaired, and can be appropriately selected according to the purpose, but is preferably 3 or more, more preferably 5 or more, and 7
The above is particularly preferable.

  As described above, the void-containing resin molded body has various excellent characteristics in, for example, reflectance, glossiness, thermal conductivity, and the like due to the inclusion of the void. In other words, characteristics such as reflectance, glossiness, and thermal conductivity can be adjusted by changing the mode of the cavities contained in the cavities-containing resin molding.

-Glossiness-
The glossiness of the void-containing resin molded product is preferably 60 or more, more preferably 70 or more, and particularly preferably 80 or more.
Here, the glossiness can be measured by a variable glossmeter.

-Light transmittance-
The light transmittance of the void-containing resin molded product is preferably 5% or less, more preferably 3% or less, and particularly preferably 1% or less.
Here, the light transmittance can be measured by a spectrophotometer.

-Thermal conductivity-
The thermal conductivity of the void-containing resin molded body is preferably 0.1 (W / mK) or less, more preferably 0.09 (W / mK) or less, and 0.08 (W / mK). mK) is particularly preferred.

Moreover, the suitable thermal conductivity of the said void containing resin molding can also be prescribed | regulated as a relative value. That is, the thermal conductivity of the void-containing resin molding is X (W / mK), and the same polymer composition as the polymer composition constituting the void-containing resin molding with the same thickness as the void-containing resin molding. The X / Y ratio is preferably 0.27 or less, when the thermal conductivity of a polymer molded body made of a product and containing no voids is Y (W / mK), and is preferably 0.2 or less. More preferably, it is particularly preferably 0.15 or less.
Here, the thermal conductivity can be calculated by a product of measured values of thermal diffusivity, specific heat, and density. The thermal diffusivity can be generally measured by a laser flash method (for example, TC-7000 (manufactured by Vacuum Riko Co., Ltd.)). The specific heat can be measured by DSC according to the method described in JIS K7123. The density can be calculated by measuring the mass of a certain area and its thickness.

-Surface smoothness-
Further, the void-containing resin molded body of the present invention is manufactured using the raw film manufactured without including a component that contributes to the development of the void as the other component of the polymer composition. In some cases, the hollow resin molded article has excellent surface smoothness because it contains the voids, but does not contain inorganic fine particles, incompatible resin, inert gas, etc. for expressing the voids. It has sex.
The surface smoothness of the void-containing resin molded body is not particularly limited and may be appropriately selected depending on the intended purpose. Ra = 0.3 μm or less is preferable, Ra = 0.25 μm or less is more preferable, and Ra = 0.1 μm or less is particularly preferable.

Furthermore, the cavity-containing resin molded body is characterized in that no cavity is formed not only on the surface of the molded body but also at a predetermined distance from the surface of the molded body.
That is, in the cross section orthogonal to the orientation direction of the cavity in the cavity-containing resin molded body, the 10 cavities having the shortest distance from the center of the cavity to the surface of the cavity-containing resin molded body are measured from each center. A distance h (i) to the surface of the void-containing resin molded body is calculated, and an arithmetic average value h (avg) of each calculated distance h (i) is expressed by the following formula: h (avg)> T / 100 Satisfy the relationship.
However, T represents the arithmetic mean value of the thickness in the cross section, and the ten cavities are separated from any one straight line parallel to the thickness direction by 20 × T parallel to the one straight line. Are selected from cavities existing in a region sandwiched by other straight lines positioned at the same time.

The “center of the cavity” means the center when the cross-sectional shape of the cavity in the cross section is a perfect circle, and is arbitrarily set by, for example, the maximum square center method in the case of other shapes. The center of the circle that minimizes the sum of squares of the deviation from the reference circle is determined, and this is set as the center of the cavity.
The “surface of the void-containing resin molded body” means the outermost surface of the void-containing resin molded body in the thickness direction. Usually, it means the upper surface when the void-containing resin molded body is placed.

Specifically, a cross-section (see FIG. 3D) perpendicular to the surface of the void-containing resin molded body and perpendicular to the longitudinal stretching direction (see FIG. 3D) is an appropriate magnification of 300 to 3,000 times using a scanning electron microscope. Microscope and take a cross-sectional picture. In the cross-sectional photograph, an arithmetic average value T of the thickness is calculated. As the arithmetic average value T of the thickness, a thickness measured using a long range contact displacement meter or the like may be used. In addition, FILM THICKNESS TESTER KG601B manufactured by Anritsu can be used for measuring the thickness.
Next, an arbitrary straight line parallel to the thickness direction is drawn in the cross-sectional photograph, and another straight line that is parallel to the single straight line and separated by 20 × T is drawn.
Then, in each cavity in the cross-sectional photograph, the center of a circle that minimizes the sum of squares of deviations from the reference circle arbitrarily set by the maximum square center method is determined, and this is set as the center of the cavity.
Then, in the region sandwiched between the one straight line and the other straight line, ten cavities having the shortest distance from the center of the cavity to the surface of the cavity-containing resin molded body are selected. The above-mentioned “distance from the center of the cavity to the surface of the cavity-containing resin molded body” means that when drawing a circle centered on the “center of the cavity”, the radius of the circle to be drawn is sequentially increased, The radius of the circle when it first contacts the surface of the void-containing resin molded body.
Then, for the 10 selected cavities, a distance h (i) from each center to the surface of the cavity-containing resin molded body is calculated, and an arithmetic average value h (avg) of each calculated distance h (i) Is calculated by the following equation (2).
h (avg) = (Σh (i)) / 10 (2)
The “distance h (i) from each center to the surface of the cavity-containing resin molded body” is to be accurately measured when the cavity-containing resin molded body is curved or stressed. Therefore, it is preferable that the measurement is performed in a state where it is placed in a flat shape.
The void-containing resin molded body has excellent surface smoothness since the void is not formed near the surface of the void-containing resin molded body while containing the void.

<Application>
Since the cavity-containing resin molded body of the present invention contains the cavity, for example, reflectors for electronic devices such as mobile phones and portable car navigations, general household illumination members, convenience store interior lighting signs, etc. Image-receiving film material or image-receiving sheet material that can be used for sublimation transfer recording material or thermal transfer recording material, various heat insulating materials, pressure-sensitive recording material, agricultural multi-film, cosmetic ingredients, paint ingredients, microwave-compatible food packaging materials It can be used as a light shielding film for windows, a light-shielding shrink film, and the like.

  Hereinafter, the present invention will be described in more detail with reference to examples. However, the following examples are not intended to limit the present invention, and all modifications may be made without departing from the spirit of the foregoing and following descriptions. Included in the technical scope.

Example 1
-Manufacture of unstretched polymer moldings-
As a polymer having crystallinity, a PBT1 (polybutylene terephthalate 100% resin, IV = 0.72, melting point: 228 ° C., glass transition temperature: 39 ° C., crystallization temperature: 190 ° C.) is twin screw extruder (screw diameter) : 20 mm, extrusion amount: 50 kg / hr), and melt-kneaded at 255 ± 3 ° C. to prepare molten PBT1 in an extruder.
The molten PBT1 was extruded from a T die disposed at the tip of a twin screw extruder and received on a 40 ° C. rotating casting drum (peripheral speed: 10 m / min, drum diameter: 60 cm). The extruded PBT 1 was cooled on a casting drum at a cooling rate of 50 ° C./second to obtain a film-like unstretched polymer molded product (raw fabric of void-containing resin molded product) with an average thickness of 50 μm.
The thickness of the unstretched polymer molded body was measured using a long range contact displacement meter AF030 (measurement unit) and AF350 (instruction unit) manufactured by Keyence Corporation.

--- Haze value of unstretched polymer molding--
The haze value of the unstretched polymer molded product was measured online using an online spectral transmission meter manufactured by NIRECO.

--Resection of unstretched polymer molding--
Of the unstretched polymer molded body, a portion having a haze value of 20% or more was excised with a Kyocera carbide cutter.
In addition, the longitudinal both ends area | region containing this part was removed in the longitudinal direction of the original fabric, and the whitening area | region which generate | occur | produces intermittently in an original fabric center part was excised along the transversal direction of an unstretched polymer molded object.
The stretched polymer molded body that had been excised was used as a raw film, and the film was wound and stretched as described below.

--- Rolling up the original film ---
The original film needs to be taken up by a take-up device (roll stock device) after being cut in the short direction.
The winding property at the time of winding the raw film was evaluated according to the following evaluation criteria. The results are shown in Table 2.
(Double-circle): It was able to wind up favorable.
○: Although it was able to be wound up, a part of the winding was shifted.
X: Although it was able to wind up, wrinkles entered into the film due to winding deviation.
XX: Winding misalignment and wrinkles occurred during winding, and cracks and cracks occurred in the whitened portion [this portion breaks with a high probability during feeding].

--Stretching of raw film--
The raw film obtained above was uniaxially stretched (longitudinal stretching). The uniaxial stretching is uniaxial stretching at a speed of 100 mm / min in a heated atmosphere of 40 ° C., and after confirming that necking has occurred and is suitable for the production of a void-containing resin molded product, 6,000 mm The film was further monoaxially stretched in the same direction as the beginning at a speed of / min. In addition, the said extending | stretching was performed by the continuous type.
The stretchability of the unstretched polymer molded body was evaluated according to the following evaluation criteria. The results are shown in Table 2.
(Double-circle): It was able to extend | stretch stably except a junction part.
○: Except for the joint part, it was able to be stretched, but wrinkles were formed in part, and elongation unevenness occurred in the wrinkled part.
X: Elongation unevenness occurred not only at the wrinkled part, but also the film was broken at the strong wrinkled part and the stretching was interrupted.
XX: Cracks occurred and frequently broke. Drawing was often interrupted.
XXX: Break frequently. After passing the film through the longitudinal stretching apparatus, when a speed difference was given to the stretching nip roll for stretching, the product was almost broken and almost no product was obtained.

(Example 2)
In Example 2, a raw film was produced in the same manner as in Example 1 except that the part to be cut was replaced with a part having a haze value of 20% or more and a part having 10% or more.

(Example 3)
In Example 3, a raw film was produced in the same manner as in Example 1 except that the part to be cut was replaced with a part having a haze value of 20% or more and a part having 25% or more.

(Comparative Example 1)
In Comparative Example 1, a raw film was produced in the same manner as in Example 1 except that the portion having a haze value of 20% or more was not cut, but as shown in Table 2, good winding and stretching Could not do.

(Comparative Example 2)
In Comparative Example 2, a raw film was produced in the same manner as in Example 1 except that the part to be cut was replaced with a part having a haze value of 30% or more instead of a part having a haze value of 20% or more. The roll-up property and stretchability of the raw film were measured in the same manner as in Example 1.

(Comparative Example 3)
In Comparative Example 3, a raw film was produced in the same manner as in Example 1 except that the part to be cut was replaced with a part having a haze value of 20% or more and a part having 40% or more. The roll-up property and stretchability of the raw film were measured in the same manner as in Example 1.

-Evaluation method-
The raw film obtained in Examples 1 to 3 and Comparative Examples 1 to 3 was measured for yield as well as the above-described rollability and stretchability. The yield is the area A of the unstretched polymer molded product, and after the excision target portion of the unstretched polymer molded product is excised, the stretched film obtained as a film containing voids is defined as a. , A / A is expressed as a percentage. The results are shown in Table 2.

The raw film produced in Examples 1 to 3 and Comparative Examples 1 to 3 are summarized in Table 2.

Although the said raw film of this invention can be used for various uses, it can be used suitably especially for a cavity containing resin molding.
Since the cavity-containing resin molded body of the present invention contains the cavity, for example, reflectors for lighting devices for electronic devices such as mobile phones and portable car navigation systems, general household lighting members, convenience store interior lighting signs, etc. Image-receiving film material or image-receiving sheet material that can be used for sublimation transfer recording material or thermal transfer recording material, various heat insulation materials, pressure-sensitive recording material, agricultural multi-film, cosmetic ingredients, paint ingredients, microwave-compatible food packaging materials It can be used as a light-shielding film for windows, a light-shielding shrink film, and the like.

FIG. 1 is a diagram showing an example of a method for producing an unstretched polymer molded body of the present invention. FIG. 2 is a view showing an example of a method for producing a cavity-forming resin molded body of the present invention, and is a flow diagram of a biaxially stretched film production apparatus. FIG. 3A is a diagram for specifically explaining the aspect ratio, and is a perspective view of the void-containing resin molded body. FIG. 3B is a diagram for specifically explaining the aspect ratio, and is a cross-sectional view taken along the line A-A ′ of the void-containing resin molded body in FIG. 3A. FIG. 3C is a diagram for specifically explaining the aspect ratio, and is a B-B ′ sectional view of the void-containing resin molded body in FIG. 3A. FIG. 3D is a cross-sectional view taken along the line A-A ′ in FIG. 3A for explaining a method of measuring the distance from the film surface of the ten cavities located closest to the film surface. FIG. 4 is a plan view showing a cut portion of the unstretched polymer molded body. FIG. 5 is an explanatory diagram of an example of a traveling film cutting apparatus. FIG. 6A is an explanatory diagram of an example of a roller-type film cutting device. FIG. 6B is an explanatory diagram of an example of a roller-type film cutting device. FIG. 6C is an explanatory diagram of an example of a roller-type film cutting device. FIG. 6D is an explanatory diagram of an example of a roller-type film cutting device. FIG. 6E is an explanatory diagram of an example of a roller-type film cutting device. FIG. 7 is an explanatory view of an outline of an example of an apparatus for producing an unstretched polymer molded body.

Explanation of symbols

DESCRIPTION OF SYMBOLS 201 Casting drum 205 Extruded polymer composition 206 Unstretched polymer molding 207 T die 209 Guide roll 210 Nip roll 11 Raw material 12 Twin screw extruder / single screw extruder 13 T die 14 Casting drum F Film or sheet 15 Longitudinal stretching machine 15a roll 16 transverse stretching machine 16a clip 1 cavity-containing resin molded body 17 expansion roll 18 roll-wrapped cavity-containing resin molded body 1a surface 100 cavity r thickness of cavity at aspect ratio L length of cavity at aspect ratio 30 width direction Both ends 150 Cutting target portion 160 Longitudinal cutting line 170 Short cutting line 180 Unstretched polymer molded body 213 Original fabric 215 X-axis direction rail 214 Y-axis direction rail 217 Laser head 92 Tha blades 91 metal roller 93 pressing roller 94 transport rollers

Claims (11)

An extrusion process in which a polymer composition containing a polymer having crystallinity is subjected to hot melt extrusion, and the extruded polymer composition is cooled to form an unstretched polymer molded body;
And a cutting step of cutting at least a portion having a haze value of 25% or more of the unstretched polymer molded body. A method for continuously producing a raw film for use in a void-containing resin molded body.   The continuous manufacturing method of the raw film used for the void containing resin molding of Claim 1 which further includes the haze value detection process of detecting the haze value of an unstretched polymer molding.   The method for continuously producing a raw film for use in a void-containing resin molded article according to any one of claims 1 to 2, further comprising a winding step of winding the raw film having a haze value of at least 25% cut off. .   The method for continuously producing a raw film for use in a void-containing resin molded product according to any one of claims 1 to 3, wherein the raw film is amorphous.   The continuous manufacturing method of the raw film used for the void containing resin molding in any one of Claim 1 to 4 in which the polymer which has crystallinity contains a polybutylene terephthalate. An extrusion means for hot-melt extruding a polymer composition containing a crystalline polymer, and cooling the extruded polymer composition to form an unstretched polymer molded body;
And a cutting means for cutting at least a portion having a haze value of 25% or more of the unstretched polymer molded body. A continuous production apparatus for a raw film for use in a void-containing resin molded body.   The continuous production apparatus of the raw film provided to the void-containing resin molded article according to claim 6, further comprising a haze value detecting means for detecting a haze value of the unstretched polymer molded article.   The continuous production apparatus for a raw film for use in a void-containing resin molded article according to any one of claims 6 to 7, further comprising a winding means for winding up the raw film having a haze value of 25% or more cut off. .   An original film for use in a void-containing resin molded article, which is produced by the method for continuously producing an original film according to any one of claims 1 to 5.   6. A void-containing resin molded article comprising a stretching step of stretching a raw film produced by the continuous production method of a raw film provided to the void-containing resin molded article according to claim 1. Production method.   A void-containing resin molded article obtained by stretching a raw film produced by the continuous production method of a raw film for use in the void-containing resin molded article according to any one of claims 1 to 5.