JP6033721B2 - Film roll and its package - Google Patents

Description

  The present invention relates to a film roll of a polyvinyl alcohol polymer film and a package thereof.

  Polyvinyl alcohol polymer films (hereinafter, “polyvinyl alcohol polymer” may be abbreviated as “PVA”) are used in various applications, taking advantage of unique properties such as oil resistance and water solubility. .

  The flexibility of the PVA film is affected by the moisture content and heat treatment. The lower the moisture content and the stronger the heat treatment, the more rigid the film. Conversely, the higher the moisture content and the weaker the heat treatment, the softer the film. Therefore, the heat treatment conditions and moisture content of the PVA film are appropriately adjusted according to the application.

The PVA film is wound into a roll shape in the film forming process, and is usually used in various processing apparatuses by feeding the film from the film roll. At this time, the flexibility of the PVA film has a great influence on the process passability, and if the PVA film is too hard, the film tends to break or the formability is poor. used.
In particular, in the use of a release film that is laid in the mold when producing artificial marble, etc., if the film is too hard, the adhesion of the film to the corners of the mold will deteriorate, and the resulting molded product will have a poor shape May occur.

  On the other hand, when the film roll of the PVA film is used up and switched to the next film roll, it is generally carried out by connecting the end portion of the previous film and the front end portion of the next film with a tape or the like. However, at this time, if the film is too soft, there is a problem that wrinkles are likely to occur when traveling between the conveying rolls of the processing apparatus, and a considerable amount of film and working time are lost in order to eliminate the generated wrinkles. .

  In addition, a PVA film having a high moisture content is obtained by absorbing moisture in the heat-treated PVA film (Patent Document 1 (Claims etc.)) and the film is wound in a roll shape (Patent Document 2 (paragraph 0012)). And 0053 etc.) are also known, but these do not solve the above problems.

Japanese Patent Laid-Open No. 2004-160846 JP 2000-318081 A

  The present invention provides a film roll of a PVA film that solves the drawbacks of the prior art described above, has good process passability, and can reduce loss of film and working time when switching between film rolls, and a package thereof. The purpose is to provide.

According to the present invention, the object is a film roll in which a PVA film is wound around a core tube, and the degree of swelling in the central portion in the width direction of the PVA film as the outermost layer of the film roll and the PVA of the layer in contact with the core tube The degree of swelling in the central portion in the width direction of the film is 70 to 96% of the degree of swelling in the central portion in the width direction of the PVA film in the central portion in the radial direction, and the moisture content of the entire PVA film is 4 to 12 masses. % Is achieved by providing a film roll.
In addition, by providing the film roll, the difference between the maximum value and the minimum value of the moisture content of each part in the radial direction of the film roll is 0.5 times or less with respect to the maximum value. It is achieved more preferably.
Moreover, the said objective is achieved more suitably by providing said film roll whose core pipe is a metal pipe.
Furthermore, the said objective is achieved more suitably by providing the package body which packaged said film roll in the moisture proof film.
Furthermore, moisture permeability of the moisture-proof film in the invention by not more than 2 ^· day 2 g / m, is more preferably achieved.

  In the present invention, the swelling degree in the width direction central part of the outermost PVA film of the film roll and the swelling degree in the width direction central part of the PVA film of the layer in contact with the core tube are both the width of the PVA film in the radial center part. Since the degree of swelling is slightly smaller than the degree of swelling in the center of the direction and the moisture content of the entire PVA film is kept at a moderately high level, the film does not become too hard and the process is easy to pass, and wrinkles and quality unevenness are reduced. Thus, a film roll capable of reducing the loss of the film and working time when the film roll is switched and the package body thereof are obtained.

It is the schematic of the film drawing / winding apparatus used in an Example.

  In the present invention, the swelling degree in the width direction central part of the PVA film as the outermost layer of the film roll and the swelling degree in the width direction central part of the PVA film of the layer in contact with the core tube are both the width of the PVA film in the radial center part. It is extremely important for achieving the object of the present invention that the degree of swelling is 70 to 96% with respect to the degree of swelling at the center in the direction. When such a film roll uses a PVA film in various apparatuses, when the film roll is used up and switched to the next film roll, wrinkles caused by the joint of the film can be quickly reduced. The swelling degree in the width direction center part of the PVA film of the outermost layer of the film roll and the swelling degree in the width direction center part of the PVA film of the layer in contact with the core tube are the swelling degree in the width direction center part of the PVA film in the radial center part. More preferably, it is 88 to 95%.

  Moreover, the swelling degree in the width direction center part of the PVA film of the outermost layer and the swelling degree in the width direction center part of the PVA film of the layer in contact with the core tube are each preferably selected from the range of 120 to 250% by mass, More preferably, it is 130-230 mass%, optimally 140-210 mass%. On the other hand, the degree of swelling in the central portion in the width direction of the PVA film in the central portion in the radial direction is preferably selected from the range of 125 to 280 mass%, more preferably 135 to 260 mass%, and most preferably 145 to 240. % By mass.

  Here, the degree of swelling means the ratio (water swelling degree) of the mass of water contained in the film in the saturated swelling state relative to the mass of the dry PVA film. The swelling degree of the outermost PVA film is the swelling degree of the outermost (outer peripheral surface) PVA film of the film roll, and the swelling degree of the PVA film of the layer in contact with the core tube is the innermost PVA of the film roll. The degree of swelling of the film means the degree of swelling of the PVA film at the center in the radial direction, which is a half point of the length of the wound diameter of the PVA film wound up on the film roll (that is, PVA of the outermost layer) It means the degree of swelling of the PVA film located at the intermediate point between the film and the PVA film of the layer in contact with the core tube. The degree of swelling of the PVA film at each position of these film rolls is preferably measured immediately after unwinding the target PVA film immediately after taking out the film roll from the packaging made of a moisture-proof film or the like.

  A structure in which the degree of swelling gradually decreases from the PVA film at the center in the radial direction toward the PVA film of the outermost layer and the PVA film of the layer in contact with the core tube is preferable.

  Moreover, the moisture content of the whole PVA film in the film roll of this invention is 4-12 mass%. It is important that the moisture content is maintained at a reasonably high level because the film can maintain an appropriate flexibility and can more effectively prevent film wrinkling. The optimum moisture content is 5 to 10% by mass. Moreover, it is suitable that the moisture content of a PVA film is substantially constant in any part in the radial direction of the film roll. Specifically, the difference between the maximum value and the minimum value of the moisture content of each part in the radial direction is preferably 0.5 times or less and more preferably 0.25 times or less with respect to the maximum value. The ratio is more preferably 0.2 times or less, and particularly preferably 0.1 times or less. Here, the moisture content is a mass fraction of water contained in the water-containing PVA film.

The PVA film in the present invention may be easily soluble or hardly soluble in water, and PVA is not particularly limited, but the degree of saponification is 75 mol% or more, preferably 75 to 99. 9.9 mol%, more preferably 80-99.5 mol%, the degree of polymerization is 300-8000, preferably 400-5000, more preferably 500-2500, depending on the application. Can do.
Here, the degree of saponification of PVA is the number of moles of the vinyl alcohol unit relative to the total number of moles of structural units (typically vinyl ester units) and vinyl alcohol units that can be converted to vinyl alcohol units by saponification. It refers to the ratio (mol%). The degree of saponification of PVA can be measured according to the description of JIS K6726-1994. The degree of polymerization (P) means an average degree of polymerization measured according to JIS K6726-1994. After re-saponifying and purifying PVA, the intrinsic viscosity [η] (unit) measured in water at 30 ° C. : Deciliter / g) by the following formula.
P = ([η] × 10 ³ /8.29) ^{(1 / 0.62)}

  PVA can be produced by polymerizing a vinyl ester monomer and saponifying the resulting vinyl ester polymer. Examples of vinyl ester monomers include vinyl formate, vinyl acetate, vinyl propionate, vinyl valerate, vinyl laurate, vinyl stearate, vinyl benzoate, vinyl pivalate, vinyl versatate, and the like. Among these, vinyl acetate is preferable from the viewpoint of price and availability.

  When the vinyl ester monomer is polymerized, other copolymerizable monomers can be copolymerized within a range that does not impair the effects of the invention, if necessary. Other monomers copolymerizable with such vinyl ester monomers include, for example, olefins having 2 to 30 carbon atoms such as ethylene, propylene, 1-butene and isobutene; acrylic acid and salts thereof; methyl acrylate, Ethyl acrylate, n-propyl acrylate, i-propyl acrylate, n-butyl acrylate, i-butyl acrylate, t-butyl acrylate, 2-ethylhexyl acrylate, dodecyl acrylate, octadecyl acrylate, etc. Methacrylic acid and its salts; methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, i-propyl methacrylate, n-butyl methacrylate, i-butyl methacrylate, t-butyl methacrylate, 2-ethylhexyl methacrylate, dodemethacrylate And methacrylic acid esters such as octadecyl methacrylate; acrylamide, N-methylacrylamide, N-ethylacrylamide, N, N-dimethylacrylamide, diacetoneacrylamide, acrylamidepropyldimethylamine and salts thereof, N-methylolacrylamide and derivatives thereof Methacrylamide derivatives such as methacrylamide, N-methyl methacrylamide, N-ethyl methacrylamide, methacrylamide propyl dimethylamine and salts thereof, N-methylol methacrylamide and derivatives thereof; methyl vinyl ether, ethyl vinyl ether, n -Propyl vinyl ether, i-propyl vinyl ether, n-butyl vinyl ether, i-butyl vinyl ether, t-butyl Vinyl ethers such as nyl ether, dodecyl vinyl ether and stearyl vinyl ether; Nitriles such as acrylonitrile and methacrylonitrile; Vinyl halides such as vinyl chloride, vinylidene chloride, vinyl fluoride and vinylidene fluoride; Allyl such as allyl acetate and allyl chloride Compounds; maleic acid and salts thereof or esters thereof; itaconic acid and salts or esters thereof; vinylsilyl compounds such as vinyltrimethoxysilane; isopropenyl acetate and the like.

In addition to the above, suitable copolymerizable monomers include, for example, N-vinylamides represented by N-vinylformamide and N-vinylacetamide, and suitable N-vinylamide monomers. Include monomers represented by the following formula (I), N-vinyl-2-pyrrolidones, N-vinyl-2-caprolactam and the like.
^{_{CH 2 = CH-N (R}} 1) -C (= O) -R 2 (I)
(In the formula, R ¹ represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and R ² represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms.)
In the above formula (I), examples of the alkyl group having 1 to 3 carbon atoms represented by R ¹ include a methyl group, an ethyl group, a propyl group, and an isopropyl group, and also represented by R ^2. Examples of the alkyl group having 1 to 5 carbon atoms include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a t-butyl group, a pentyl group, and an isopentyl group. Examples of the monomer represented by the formula (I) include N-methyl-N-vinylformamide and N-methyl-N-vinylacetamide.
Examples of N-vinyl-2-pyrrolidones include N-vinyl-2-pyrrolidone, N-vinyl-3-propyl-2-pyrrolidone, N-vinyl-5,5-dimethyl-2-pyrrolidone, and N-vinyl. Examples include -3,5-dimethyl-2-pyrrolidone.

More preferable copolymerizable monomers include sulfonic acid group-containing monomers. Any sulfonic acid group-containing monomer may be used as long as it contains a sulfonic acid group or a salt thereof in the molecule and can be copolymerized with a vinyl ester. Specific examples include 2-acrylamido-2-methylpropanesulfonic acid, 2-acrylamido-1-methylpropanesulfonic acid, 2-methacrylamide-2-methylpropanesulfonic acid and alkali metal salts thereof; ethylenesulfonic acid, allyl Examples thereof include olefin sulfonic acids such as sulfonic acid and methacryl sulfonic acid, and alkali metal salts thereof. Among these, 2-acrylamido-2-methylpropanesulfonic acid and alkali metal salts thereof are most preferable from the viewpoints of reactivity when copolymerized with a vinyl ester monomer and stability during saponification. Here, examples of the alkali metal include Na, K, and Li.
The copolymerization ratio of these copolymerizable monomers is preferably 15 mol% or less, and more preferably 10 mol or less. About a lower limit, 0.01 mol% or more is suitable, More preferably, it is 0.05 mol% or more.
These PVA may be used alone or in combination of two or more.

The method for obtaining the film roll of the present invention includes, for example, a method of raising the heat treatment temperature only for the PVA film at the beginning and end of winding when winding the PVA film around the core tube, and winding the PVA film around the core tube. The method of heat-treating the package body which wrapped the film roll with the moisture-proof film is illustrated. Among these, since the former requires time to change the temperature conditions of the heat treatment equipment, there is a problem that it is difficult to increase the production speed, and the latter is preferable because it is more excellent in productivity.
As a condition for heat-treating a package body in which a film roll in which a PVA film is wound around a core tube is wrapped with a moisture-proof film, a method of heat-treating at 70 to 200 ° C. for 0.5 to 120 hours is preferable. The heat treatment temperature is more preferably 80 to 190 ° C, and most preferably 85 to 185 ° C. The heat treatment time is more preferably 1 to 72 hours, and most preferably 1.5 to 60 hours.

  The method of heat treatment is not particularly limited, but a method of bringing a high-temperature material such as hot air into contact with the roll is suitable. When using an aluminum laminate film as a moisture-proof film as described later, the method of heating by infrared rays or radiant heat is reflected by the aluminum layer of the packaging material, so the efficiency tends to deteriorate, and heating by microwaves Is unsuitable.

The PVA film after the PVA film (whole PVA film) when the PVA film before heat treatment is wound around the core tube to obtain a film roll has a water content of W ₀ % by mass and the package packaged with a moisture-proof film is heat-treated When the water content of (the whole PVA film) is W mass%, it is preferable to adjust so that | W−W ₀ | <1.5 mass% is satisfied. More preferably, | W−W ₀ | <1% by mass. By adjusting in this way, the moisture content of the PVA film after heat treatment can be made almost constant at any part in the radial direction of the film roll. The value of W ₀ may be larger or smaller than the value of W.

The moisture-proof film used in the present invention preferably has a moisture permeability of 2 g / m ² · day or less in order to achieve the object of the present invention. More preferably, the moisture permeability is 1 g / m ² · day or less. Here, the moisture permeability is a value measured at 40 ° C. and 90% RH according to JIS Z0208.

  Examples of the moisture-proof film include a metal film, a moisture-resistant resin film, a resin film on which a metal is vapor-deposited, and a resin film on which silica or alumina is vapor-deposited. A metal film is particularly preferable. As the metal film, an aluminum laminate film obtained by laminating a resin film such as an aluminum foil and a moisture-resistant resin is particularly suitable because it has high moisture resistance and good bending resistance. Examples of moisture-resistant resins used as single-layer resins or laminated resins include polyesters, polyolefins, polyamides, acrylic resins (polyacrylic acid esters, polymethacrylic acid esters, etc.), halogen resins (polyvinyl chloride, polyvinylidene chloride, etc.), etc. Polyester and polyolefin are preferable. Examples of the polyester include polyethylene terephthalate, polyethylene isophthalate, polyethylene naphthalate, and polybutylene terephthalate. Among these, polyethylene terephthalate is preferable. Polyolefins include polypropylene, polyethylene, ethylene copolymers (ethylene-propylene copolymer, ionomer, etc.), polybutene, polyisobutylene, polystyrene, etc. Of these, polypropylene and high-density polyethylene are moisture-proof. High and particularly suitable.

As a method of packaging a film roll with a moisture-proof film, a method of wrapping the whole film roll with a moisture-proof film and wrapping the film roll, winding the body of the film roll with a moisture-proof film wider than the width of the film roll, and both ends of the film roll The method of wrapping the excess moisture-proof film that protrudes inside the core tube is exemplified, but the latter method allows the air to enter and exit the core tube freely, and the PVA film can be It is preferable because it can be heated.
By heat-treating the film roll package packaged in such a moisture-proof film, the moisture content in the package is hardly lowered, and any layer can keep the moisture content constant, and the film Since the PVA film of the outermost layer of the roll and the PVA film of the layer in contact with the core tube are heat-treated more highly than the PVA film of the intermediate layer, the width direction of the PVA film of the layer in contact with the outermost layer PVA film and the core tube The degree of swelling at the center is smaller than the degree of swelling at the center in the width direction of the PVA film of the intermediate layer.

  The winding diameter of the film roll used in this specification means the distance from the outer surface of the core tube to the outermost layer of the PVA film layer of the layer of the PVA film wound around the core tube, and the winding diameter is not necessarily limited. Is preferably 50 to 300 mm, and most preferably 60 to 200 mm. When the roll diameter of the film roll exceeds 300 mm, it may take too much time for the heat to penetrate into the middle part of the film. Moreover, when the winding diameter of a film roll is less than 50 mm, there exists a possibility that productivity may become bad because the winding length of the PVA film of a film roll is too short.

  The core tube used in the present invention is not particularly limited, and examples thereof include a metal tube, a resin tube, and a paper tube, and the metal tube is particularly suitable because of its high heat transfer efficiency. Examples of the metal pipe include an aluminum pipe and a steel pipe, and examples of the aluminum pipe include an aluminum pipe and an aluminum alloy pipe. Examples of the aluminum alloy include an aluminum-copper alloy, an aluminum-magnesium alloy, an aluminum-magnesium-silicon alloy, and an aluminum-zinc-magnesium-copper alloy. Examples of the steel pipe include steel ropes such as carbon steel, high-strength steel, and stainless steel, and iron steel alloys.

  The size of the core tube used in the present invention can be appropriately selected depending on the use of the PVA film, the device used, and the material of the core tube, but generally, an outer diameter of 20 to 300 mm is used, preferably 50 to 250 mm. . Moreover, about the thickness of a core pipe, the thing of 1-30 mm is generally used, However, In order to heat a PVA film also from a core pipe side, it is preferable that it is thin, and thickness is preferably 1-20 mm, 15 mm is optimal.

  The length of the core tube is preferably 2 m or more, and more preferably 3 m or more. The upper limit is preferably 10 m or less, and more preferably 8 m or less. The length of the core tube is usually the same as or slightly longer than the film width of the PVA film, but is preferably slightly longer than the film width. For example, the core tube length is preferably 1 mm to 40 cm longer than the film width, and more preferably 5 mm to 30 cm longer.

  As a method of making a film roll of a PVA film, for example, using a PVA solution in which PVA is dissolved in a solvent, a casting film forming method, a wet film forming method (discharging into a poor solvent), a dry wet film forming method , Gel film forming method (a method in which a PVA aqueous solution is once cooled and gelated, and then a solvent is extracted and removed to obtain a PVA film), and a combination of these methods, and hydrous PVA (which may contain an organic solvent, etc.) There are known methods such as a method of winding a PVA film obtained by melt extrusion film-forming method, etc., which is carried out by melting the core around a core tube. 10-70 mass% is suitable for the PVA density | concentration of the PVA solution or water-containing PVA used when manufacturing a PVA film, and 10-60 mass% is more suitable.

  The swelling degree of the PVA film wound around the core tube (swelling degree before heat treatment) is, for example, in the range of 150 to 400% by mass, although it depends on the use of the PVA film.

  Since the PVA film in the vicinity of both end faces of the film roll is subjected to a stronger heat treatment than the PVA film in other portions, there may be some difference in the physical properties of the PVA film. Therefore, depending on the use of the PVA film, it may be necessary to excise the film near the end face of the film roll. In order to reduce the proportion of the cut portion, it is advantageous that the film width is wide. From this viewpoint, the film width of the PVA film is preferably 2 m or more, more preferably 3 m or more. About an upper limit, 10 m or less is preferable and 8 m or less is more preferable.

  The thickness of the PVA film is preferably 5 to 500 μm, more preferably 10 to 150 μm. The length of the PVA film is preferably 500 m or more, and more preferably 1000 m or more.

EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to the following examples.
In the following examples and comparative examples, the degree of swelling and moisture content of the PVA film, the ease of wrinkles when switching film rolls, and the form following ability were measured by the following methods.

(1) Swelling degree of PVA film About 2 g of PVA film was collected and cut into strips having a width of 2 to 4 mm and a length of 3 to 5 cm. After immersion in distilled water at 30 ° C. for 10 minutes, the solution was dewatered in a centrifugal dehydrator at 3000 rpm for 5 minutes, and the wet weight was measured. Furthermore, drying was performed at 105 ° C. for 24 hours, and the dry weight was measured.
Then, the degree of swelling was determined by the formula [wet weight] ÷ [dry weight] × 100.

(2) Moisture content of PVA film First, the mass of the PVA film for which the moisture content was determined was weighed (mass A). Next, this PVA film was vacuum-dried at 50 ° C. for 4 hours and then weighed again (mass B). Using the obtained masses A and B, the moisture content H (mass%) of the PVA film was determined by the following formula.
H = [(A−B) / A] × 100

(3) Ease of wrinkles when switching film rolls PVA film is introduced into a film unwinding / winding device (schematic diagram shown in FIG. 1), and before the transport roll closest to the unwinding roll (feeding roll) The film is cut at the side) and the film roll to be evaluated is set on the feeding roll. The PVA film to be evaluated is fed out and passed through a tension measuring device, and the lower end of the film to be evaluated and the upper surface of the cut film are bonded to each other using a double-sided tape at the leading end of the film and the rear end of the film cut earlier. The PVA film is wound on a winding roll at a line speed of 10 m / min while adjusting the film tension to 3 Kg-cm. At this time, wrinkles derived from the connection portion of the film are generated in the film, but the wrinkles disappear gradually as the film is stabilized. The length of the film that ran until the wrinkle disappeared was defined as the “wrinkle disappearance length”, which was used as an index of wrinkle ease.

(4) Formwork followability An iron formwork having a recess of 2.5 cm in depth of 30 cm × 30 cm is prepared, and a PVA film cut into 50 cm × 50 cm is spread over the recess. Next, about 1.5 kg of paraffin having a melting point of 61 ° C. was heated to 80 ° C. to be melted, poured into the depression of the upper mold, and cooled at room temperature. After the paraffin has solidified sufficiently, the paraffin is removed from the mold with the PVA film, and then the PVA film is slowly removed. The obtained flat paraffin was visually observed for the sharpness of the corners formed by the bottom and side surfaces, and ranked according to the following criteria.
A: The corners are sharply sharp and are equivalent to the corners of the mold without the PVA film. B: The corners are slightly rounded, but there is no practical problem. C: The corners are rounded. D: Level that allows easy recognition of differences from D

[Example 1]
After 100 parts by mass of PVA (polyvinyl acetate saponified product) having a saponification degree of 98.5 mol% and a polymerization degree of 1700 were immersed in 2500 parts by mass of distilled water at 35 ° C. for 24 hours, centrifugal dehydration was performed to obtain a PVA water-containing chip. Obtained. The moisture content in the obtained PVA water-containing chip was 70% by mass. After adding 333 parts by mass of this PVA water-containing chip (100 parts by mass in terms of dry PVA), 10 parts by mass of glycerin and 1.5 parts by mass of a surfactant (main component is lauric acid diethanolamide), they are mixed well. The mixture was heated and melted with a twin screw extruder having a maximum temperature of 130 ° C. After cooling to 100 ° C. with a heat exchanger, the film is melt-extruded onto a 85 ° C. metal drum, dried, and further run on a plurality of 75 ° C. drying rolls, thereby having a film width of 1.2 m and a thickness of 30 μm. A PVA film was formed. This PVA film was wound up 1200 m on a paper tube having an inner diameter of 3 inches to obtain a film roll of PVA film. Outside of the obtained film roll, in order to prevent out of water vapor to the film roll, an aluminum laminate film (polyethylene terephthalate / aluminum foil / polypropylene laminate film moisture permeability 0.1 g / m 2 ^· day, the polypropylene side inside And packed with At this time, the paper tube was packed so that the openings at both ends of the paper tube were not blocked.
This packed film roll was put in a dryer at 100 ° C. and subjected to heat treatment (hot air drying) for 24 hours.
The degree of swelling and moisture content of the PVA film after the heat treatment, the ease of wrinkling when the film roll was switched, and the form following ability were evaluated. The results are shown in Table 1.

[Example 2]
The film roll of the PVA film heat-treated in the same manner as in Example 1 except that the conditions for heat-treating the film roll of the PVA film packed with the aluminum laminate film in Example 1 were changed to 110 ° C. for 16 hours. Got. In the same manner as in Example 1, the degree of swelling and moisture content of the PVA film, the ease of wrinkling when the film roll was switched, and the form following ability were evaluated. The results are shown in Table 1.

[Example 3]
In Example 2, the film roll of the heat-treated PVA film was changed in the same manner as in Example 2 except that the core tube for winding the formed PVA film was changed from a paper tube to an aluminum pipe (inner diameter: 3 inches). Obtained. In the same manner as in Example 2, the degree of swelling and moisture content of this PVA film, the ease of wrinkling at the time of film roll switching, and the form following ability were evaluated. The results are shown in Table 1.

[Example 4]
In Example 2, except that the film for packing the PVA film formed and wound was changed from an aluminum laminate film to a high-density polyethylene film (moisture permeability of 1.5 g / m ² · day). Similarly, the film roll of the heat-treated PVA film was obtained. In the same manner as in Example 2, the degree of swelling and moisture content of this PVA film, the ease of wrinkling at the time of film roll switching, and the form following ability were evaluated. The results are shown in Table 1.

[Comparative Example 1]
In Example 1, without subjecting the PVA film packed with the aluminum laminate film to heat treatment, the degree of swelling and moisture content of this PVA film, the ease of wrinkles when switching film rolls, The formwork following ability was evaluated. The results are shown in Table 1.

[Comparative Example 2]
In Example 2, the outer side of the film roll of the obtained PVA film was not packed with an aluminum laminate film, and heat treatment was performed in the same manner as in Example 2. In the same manner as in Example 2, the degree of swelling and moisture content of this PVA film, the ease of wrinkling at the time of film roll switching, and the form following ability were evaluated. The results are shown in Table 1.

[Comparative Example 3]
In Example 2, when the outside of the film roll of the obtained PVA film is packed with an aluminum laminate film, the openings at both ends of the paper tube are also covered with the aluminum laminate film so that air cannot freely enter and exit the inside of the paper tube. A heat treatment was performed in the same manner as in Example 2 except that. In the same manner as in Example 2, the degree of swelling and moisture content of this PVA film, the ease of wrinkling at the time of film roll switching, and the form following ability were evaluated. The results are shown in Table 1.

[Comparative Example 4]
In Example 1, before the film-formed PVA film was wound around the paper tube, online heat treatment was performed by bringing the PVA film into contact with a metal roll at 150 ° C., and the film was wound around the paper tube. The film roll of the obtained PVA film was packed with an aluminum laminate film in the same manner as in Example 1, but heat treatment by a dryer was not performed. In the same manner as in Example 1, the degree of swelling and moisture content of the PVA film, the ease of wrinkling when the film roll was switched, and the form following ability were evaluated. The results are shown in Table 1.

[Comparative Example 5]
In Example 2, except that the film for packing the PVA film formed and wound was changed from an aluminum laminate film to a low density polyethylene film (moisture permeability 4.5 g / m ² · day). Similarly, the film roll of the heat-treated PVA film was obtained. In the same manner as in Example 2, the degree of swelling and moisture content of this PVA film, the ease of wrinkling at the time of film roll switching, and the form following ability were evaluated. The results are shown in Table 1.

  A film roll of PVA film that is homogeneous, has good processability, and can reduce loss of film and work time when switching between film rolls, release film, film for packaging textile products, optical use It is extremely useful for films.

1. 1. Feeding roll 2. Tension measuring roll 3. Transport roll Winding roll

Claims (5)

  A film roll in which a polyvinyl alcohol polymer film is wound around a core tube, the degree of swelling in the central portion in the width direction of the polyvinyl alcohol polymer film as the outermost layer of the film roll, and a polyvinyl alcohol system in a layer in contact with the core tube The degree of swelling at the center in the width direction of the polymer film is 70 to 96% of the degree of swelling at the center in the width direction of the polyvinyl alcohol polymer film at the center in the radial direction, and the polyvinyl alcohol polymer. The film roll whose moisture content of the whole film is 4-12 mass%.   The film roll according to claim 1, wherein the difference between the maximum value and the minimum value of the moisture content of each part in the radial direction of the film roll is 0.5 times or less with respect to the maximum value.   The film roll according to claim 1 or 2, wherein the core tube is a metal tube.   The package which packaged the film roll of any one of Claims 1-3 with a moisture-proof film. The package according to claim 4, wherein the moisture permeability of the moisture-proof film is 2 g / m ² · day or less.

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