JP2017014412A - Film having excellent disintegration - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a film having excellent disintegration.SOLUTION: A film comprises biodegradable resin and has at least one side (R side) with an end face roughness of 10 μm or more and 50,000 μm or less but does not have a side with an end face roughness of more than 50,000 μm.SELECTED DRAWING: None

Description

  The present invention relates to a film having excellent disintegration properties.

  In recent years, with the growing awareness of the environment, the problem of soil contamination due to the disposal of plastic products has attracted attention. As a countermeasure, research has been conducted on a resin having a characteristic of degrading in a natural environment, ie, a biodegradable resin. However, biodegradation of a biodegradable resin proceeds over time, and generally does not have a characteristic of instantaneously occurring at a desired timing.

  On the other hand, in Patent Document 1 and Patent Document 2, the decomposition of the film containing the biodegradable resin is considered by dividing into the volume reduction by the collapse of the film and the subsequent biodegradation, and the degradation of the biodegradable resin is destroyed. The idea of supplementing with sex is described.

  Patent Document 1 describes a disintegratable film that can be composted by laminating a polyvinyl alcohol polymer on a layer made of a polylactic acid resin, which is a typical biodegradable resin. However, since the film described in Patent Document 1 is intended for use as a packaging material, it is designed to have high elongation in all directions in the film plane, and includes a layer containing a polyvinyl alcohol-based polymer. After dissolving in water and decomposing, there is a problem that it still takes a long time until biodegradation proceeds in the polylactic acid resin part.

  On the other hand, Patent Document 2 proposes a film that rapidly collapses due to external stress by weakening the film strength in a specific direction. However, since the disintegration property of the film described in Patent Document 2 depends on the strength of the stress, there is a problem that it takes time to disintegrate when the stress applied to the film is small.

JP 2009-96096 A JP 2014-173074 A

  In view of the background of such conventional technology, the present invention is intended to provide a film having excellent disintegration properties.

In order to solve the above problems, the present invention has the following configuration.
(1) It contains at least one side (R side) that contains a biodegradable resin and has an end surface roughness of 10 μm or more and 50,000 μm or less, and no end surface roughness that exceeds 50,000 μm. A film characterized by that.
(2) The film according to (1), wherein the film has at least one side (S side) having an end surface roughness of 0 μm or more and less than 10 μm.
(3) The film according to (1) or (2), wherein the shape when observed from a direction perpendicular to the film surface is a quadrangular shape.
(4) The film according to any one of (1) to (3), wherein two opposing sides are R sides.
(5) The film according to any one of (1) to (4), wherein a tensile elongation in a direction parallel to the R side is 5% or more and 60% or less.
(6) When the tensile strength in the direction perpendicular to the R side is FMD and the tensile strength in the direction parallel to the R side is FTD, the ratio (FMD / FTD) is 5 or more and 15 or less. The film according to any one of (1) to (5).
(7) The film according to any one of (1) to (6), wherein the porosity is from 10% to 80%.
(8) A laminate formed by bonding the film according to any one of (1) to (7) and a nonwoven fabric.

  According to the present invention, a film excellent in disintegration is provided. The film of the present invention can be preferably used for applications where disintegration is required. Specifically, agricultural materials such as multi-films, forestry materials such as fumigation sheets, sanitary materials such as paper diapers, napkins and liners, various packaging materials such as plastic bags, garbage bags, foods, industrial products, For example, it can be preferably used.

Observation direction for determining the end face roughness of the film side. An example of an R side (S side) that is not a true straight line. Schematic of a cutting blade for film cutting. The schematic of the cutting blade for film cutting whose shape at the time of observing as a whole from the front end direction is a square shape.

(Biodegradable resin)
It is important that the film of the present invention contains a biodegradable resin in order to impart biodegradability. The biodegradable resin in the present invention means a resin having a biodegradability of 60% or more within one year when tested according to JIS K6953-1 (2011).

  Examples of the biodegradable resin in the present invention include aliphatic polyesters, aliphatic aromatic polyesters, polysaccharides, polymers containing starch, and polyvinyl alcohol.

  Specific examples of the aliphatic polyester include polylactic acid resin, polyglycolic acid, poly (3-hydroxybutyrate) resin, poly (3-hydroxybutyrate · 3-hydroxyhexanoate) resin, poly (3-hydroxy Biodegradability such as butyrate-3-hydroxyvalerate) resin, polycaprolactone resin, polybutylene succinate resin, poly (butylene succinate adipate) resin, and block copolymer of polylactic acid resin and polyethylene glycol Examples thereof include a copolymer comprising a resin and other copolymer components.

  Specific examples of the aliphatic aromatic polyester include poly (ethylene succinate / terephthalate) resin, poly (butylene succinate / terephthalate) resin, poly (butylene adipate / terephthalate) resin, and the like.

  Specific examples of the polysaccharide include cellulose resins such as cellulose acetate resin and glucosamine resins such as chitosan resin.

  Specific examples of the polymer containing starch include a melt-kneaded product of polyethylene resin and starch, a melt-kneaded product of polylactic acid and starch, and the like.

  Among these biodegradable resins, it is preferable to include a polylactic acid-based resin from the viewpoint of biomass degree, cost, processability, and the like.

  The lower limit of the content of the biodegradable resin in 100% by mass of all the components of the film of the present invention is preferably 20% by mass, and preferably 30% by mass from the viewpoint of maintaining high biodegradability. More preferably, it is more preferably 40% by mass.

  The upper limit of the content of the biodegradable resin is preferably as high as possible from the viewpoint of imparting biodegradability, but is preferably 90% by mass and more preferably 80% by mass in consideration of imparting moisture permeability described later. Preferably, it is 70 mass%.

  Moreover, the film of this invention can contain 2 or more types of biodegradable resin as needed. At this time, content of biodegradable resin means the sum total of content of all the biodegradable resin which a film contains.

(End surface roughness)
It is important that the film of the present invention has at least one side (R side) having an end surface roughness of 10 μm or more and 50,000 μm or less and no side having an end surface roughness exceeding 50,000 μm. is there. When the film has the R side, the film can be collapsed by using the R side even if the stress is very small. Moreover, it becomes possible to prevent that disintegration becomes high too much by not having the edge | side whose surface roughness exceeds 50,000 micrometers.

  Here, the end face roughness means that one side of the film is perpendicular to the film surface, and the magnification is 100 times with a microscope (when the roughness curve protrudes from the observation screen at a magnification of 100 times, the magnification is 10). Magnification) (Fig. 1), and the orthographic projection of the obtained observation image is read on a two-dimensional coordinate, and then the arithmetic mean roughness value calculated by the method described in JISB 0601 (1994). .

  A side having an end surface roughness of less than 10 μm is excellent in smoothness and may not act as a trigger for collapse. Therefore, a film whose end face roughness on all sides is less than 10 μm may not be collapsed by a minute stress. In addition, when there is a side having an end surface roughness of more than 50,000 μm, the disintegration property of the film becomes too high, and the film may be unintentionally torn during post-processing.

  The end surface roughness of the R side is preferably 100 μm or more and 50,000 μm or less, and more preferably 1,000 μm or more and 5,000 μm or less from the viewpoint of imparting appropriate disintegration properties to the film.

  The end surface roughness can be adjusted by the shape of the cutting blade used for cutting or punching the film. More specifically, if the unevenness of the cutting blade viewed from the tip direction is reduced, the end surface roughness can be reduced, and if the unevenness of the cutting blade viewed from the tip direction is increased, the end surface roughness can be increased. it can.

  The film of the present invention preferably has at least one side (S side) having an end face roughness of 0 μm or more and less than 10 μm. When the film further has an S side, it is possible to impart an anisotropic characteristic to the film such that collapse is likely to occur from the R side portion, whereas collapse is less likely to occur from the S side portion.

  The R side and the S side are preferably straight when viewed as a whole from the viewpoint of disintegration and workability, but as long as the effect of the present invention is not impaired, It suffices if the shape is substantially linear. That is, the R side and the S side are not limited to true straight lines, and may be in a form as shown in e to i of FIG. Note that the observation as a whole refers to observing the film from a distant position, and means that the end surface roughness, minute bends and bends (e to i in FIG. 2) existing on the side can be ignored.

  Furthermore, in the film of the present invention, it is preferable that two opposite sides are R sides. When the two R sides are opposed to each other, tearing in the direction perpendicular to the R side is likely to occur, and as a result, the collapse property in the direction can be enhanced. The two sides facing each other means two sides positioned so as to be substantially parallel to each other when observed as a whole, and substantially parallel means that the angle formed by the two sides is 5 ° or less. That means.

(Film shape)
The film of the present invention preferably has a square shape when observed from a direction perpendicular to the film surface from the viewpoint of disintegration and processability. Here, the shape when observed from the direction perpendicular to the film surface refers to the shape when observed as a whole from the direction perpendicular to the film surface.

  When the above-mentioned R side exists in the film, even if the shape of the film when observed as a whole is a quadrangle, if the film is observed microscopically, it becomes a polygon due to the presence of the end face roughness. Further, as described above, there are cases where the R side and / or the S side are not true straight lines as shown in FIG. Since the film of the present invention includes such an embodiment, the shape when observed as a whole may be a rectangular shape.

(Tensile elongation)
The film of the present invention preferably has a tensile elongation in the direction parallel to the R side of 5% or more and 60% or less from the viewpoint of imparting appropriate disintegration to the film. Parallel to the R side means parallel to the R side when observed as a whole.

  When the tensile elongation in the direction parallel to the R side is larger than 60%, even if stress is applied to the film, the film stretches following the stress, and thus sufficient disintegration may not be obtained. On the other hand, when the tensile elongation in the direction parallel to the R side is less than 5%, the disintegration property of the film becomes too high, and the film may tear unintentionally during post-processing. From the viewpoint of imparting appropriate disintegration properties to the film, the tensile elongation in the direction parallel to the R side is more preferably from 10% to 50%, and even more preferably from 15% to 40%.

  Here, the tensile elongation refers to a strip-shaped sample having a length of 100 mm in the measurement direction and a length of 10 mm in the direction perpendicular to the measurement direction, a room temperature of 23 ° C., a relative humidity of 65%, and an initial tensile chuck. It refers to the tensile elongation measured by the method defined in JIS K-7127 (1999) under the conditions of a distance of 40 mm and a tensile speed of 200 mm / min.

  The method for adjusting the tensile elongation in the direction parallel to the R side to 5% or more and 60% or less is not particularly limited as long as the effects of the present invention are not impaired. For example, in the film production method described later, Is stretched in a uniaxial direction and cut with a cutting blade so that the R side is formed perpendicular to the stretching direction, or the film is stretched in a biaxial direction so that the R side is perpendicular to the stretching direction having a large magnification. The method of cutting with a cutting blade so that it may be formed is mentioned. The R side being formed perpendicular to the stretching direction means that the R side is formed such that the R side when observed as a whole is perpendicular to the stretching direction.

  When the above-described method is used, if the film is stretched in a uniaxial direction, the tensile elongation in the direction parallel to the R side can be increased as the stretch ratio is increased. If the film is stretched in the biaxial direction, the tensile elongation in the direction parallel to the R side is increased as the stretching ratio in the direction in which the stretching ratio is smaller is smaller and the difference in the stretching ratio in the two directions is larger. be able to.

(Tensile strength)
The film of the present invention has a ratio (FMD) when the tensile strength in the direction perpendicular to the R side is FMD and the tensile strength in the direction parallel to the R side is FTD from the viewpoint of imparting appropriate disintegration to the film. / FTD) is preferably 5 or more and 15 or less, and more preferably 7 or more and 13 or less. By setting FMD / FTD within the above range, the film can be remarkably imparted with the characteristic that it is easily collapsed by tearing in the direction perpendicular to the R side and hardly collapsed in the direction parallel to the R side. . Being perpendicular to the R side means being parallel to the film surface and perpendicular to the R side when observed as a whole.

  Here, FMD / FTD means what was computed from FMD and FTD measured by the method prescribed | regulated to JISK-7127 (1999) on the conditions similar to tensile elongation.

  When there are a plurality of R sides, FMD / FTD is calculated with the R side having the largest end surface roughness as the R side.

  The method for setting the value of FMD / FTD to 5 or more and 15 or less is not particularly limited as long as the effects of the present invention are not impaired. For example, in the method for producing a film described later, the film is stretched in a uniaxial direction. A method of cutting with a cutting blade so that the R side is formed perpendicular to the stretching direction, or a cutting blade so that the R side is formed perpendicular to the stretching direction with a high magnification by stretching the film biaxially. The method of cutting with is mentioned.

(Porosity)
From the viewpoint of imparting moisture permeability, the film of the present invention preferably has a porosity of 10% to 80%, more preferably 20% to 75%, and more preferably 30% to 70%. More preferably it is.

  By setting the porosity to 10% or more and 80% or less, moisture permeability can be imparted to the film of the present invention, and the film can be suitably used in a field requiring moisture permeability.

Here, the porosity means that measured and calculated by the following procedure. First, the specific gravity (specific gravity (ρ)) of the film was measured with an electronic hydrometer under conditions of room temperature of 23 ° C. and relative humidity of 65%, and then the film was hot-pressed under conditions of a temperature of 280 ° C. and a pressure of 5 MPa. The specific gravity (specific gravity (d)) of the non-porous sheet obtained by quenching with water at 25 ° C. was measured in the same manner, and the porosity was calculated from the specific gravity (ρ) and specific gravity (d) by the following formula. calculate.
Porosity (%) = [(d−ρ) / d] × 100
The method for adjusting the porosity to 10% or more and 80% or less is not particularly limited as long as the effects of the present invention are not impaired, but a method of combining a biodegradable resin and a filler to be described later in a preferable kind and a mixing ratio, The method of adjusting a draw ratio etc. with the manufacturing method of the film to perform is mentioned. More specifically, for example, the porosity can be increased by increasing the filler content or increasing the draw ratio.

(Thickness)
The film of the present invention preferably has a thickness of 5 μm or more and 200 μm or less, more preferably 7 μm or more and 150 μm or less, and even more preferably 10 μm or more and 100 μm or less from the viewpoint of achieving both handleability and disintegration. .

  Here, the thickness means an average value of thickness values measured at 5 points at intervals of 1 cm in the flow direction and the width direction of the film using a dial gauge thickness gauge. The flow direction refers to the direction in which the film proceeds during film production, and the width direction refers to the direction that is parallel to the film transport surface and orthogonal to the flow direction.

  By setting the thickness to 5 μm or more, the firmness of the film becomes strong, the handleability is excellent, and the roll winding shape and unwinding property are good. Further, by setting the thickness to 200 μm or less, the film is easily collapsed by stress.

(Moisture permeability)
Film of the present invention, when used in applications where moisture permeability is required, moisture permeability 300g ^/ (m 2 · day) or more, preferably 5,000g ^/ (m 2 · day) or less. By setting the moisture permeability to such a range, it can be preferably used for applications that require moisture permeability.

  Here, the moisture permeability refers to a value of moisture permeability obtained by measurement according to a method defined in JIS Z0208 (1976) with a constant temperature and humidity apparatus set at 25 ° C. and 90% RH.

If the film is used for applications requiring moisture permeability, the lower limit of moisture permeability is more preferably 500 g / (m ² · day), and 1,000 g / (m ² · day). Is more preferable, and is particularly preferably 1,500 g / (m ² · day). In order to achieve both a practical level of moisture permeability and mechanical properties, the upper limit value of moisture permeability is more preferably 3,500 g / (m ² · day).

(filler)
The film of the present invention may contain a filler in order to improve moisture permeability. Here, the filler refers to a substance added as a base material for improving various properties, or an inert substance added for the purpose of increasing the amount, increasing the volume, reducing the cost of the product, or the like.

  As such a filler, as long as the effects of the present invention are not impaired, known inorganic fillers and / or organic fillers can be used. However, improvement of moisture permeability of the film, maintenance of mechanical properties such as strength and elongation, From the viewpoint of cost reduction, calcium carbonate, barium carbonate, barium sulfate, calcium sulfate, silicon oxide (silica), titanium oxide, mica, talc, kaolin, clay, and montmorillonite are preferable. Calcium is more preferred.

  The content of the filler in the film of the present invention is preferably 10% by mass or more and 80% by mass or less, and 20% by mass or more and 70% by mass with respect to 100% by mass of all components of the film from the viewpoint of imparting moisture permeability. More preferably, it is at most 30 mass%, more preferably at least 30 mass% but at most 60 mass%.

  By setting the amount of the filler to 10% by mass or more and 80% by mass or less, pores are formed in the film during stretching described later, and moisture permeability can be imparted.

(Additive)
The film of the present invention may contain various additives as long as the effects of the present invention are not impaired. For example, antioxidants, UV stabilizers, anti-coloring agents, matting agents, antibacterial agents, deodorants, weathering agents, antistatic agents, antioxidants, ion exchange agents, tackifiers, antifoaming agents, Color pigments and dyes can be used. Moreover, the film of this invention may contain thermoplastic resins other than biodegradable resin in the range which does not impair the effect of this invention.

(Composite)
The film of this invention can also be made into the laminated body bonded together with the nonwoven fabric. Such a laminate is excellent in disintegration and decomposability and can be preferably used as a sanitary material. Moreover, when bonding the film of this invention and a nonwoven fabric, you may give the process of cutting off the corner | angular part of a film and making it into curvilinear form.

(Production method)
Next, although the method for producing the film of the present invention will be specifically described, the present invention is not limited to this.

  In obtaining a composition constituting the film of the present invention, that is, a composition containing a biodegradable resin and other components as required, a melt-kneading method for producing a composition by melt-kneading each component Is preferred. In the melt-kneading method, a known mixer such as a kneader, roll mill, Banbury mixer, single-screw or twin-screw extruder can be used as long as the effects of the present invention are not impaired. Among these, from the viewpoint of productivity, it is preferable to use a single screw or twin screw extruder.

  Although the temperature at the time of melt kneading varies depending on the melting point and softening point of the biodegradable resin, for example, when the biodegradable resin is a polylactic acid resin, 150 ° C. to 240 ° C. is preferable, and 170 ° C. to 210 ° C. is more preferable. By setting the temperature at the time of melt kneading of the polylactic acid resin to 150 ° C. to 240 ° C., it becomes possible to appropriately melt knead, and by setting the temperature to 170 ° C. to 210 ° C., further preventing deterioration of the polylactic acid resin Is possible.

  The film of the present invention can be produced by an existing film production method such as a known inflation method, a tubular method, or a T-die cast method using, for example, the melt-kneaded material obtained by the above-described method.

  Furthermore, in order to set the tensile elongation in a specific direction to 5% or more and 60% or less, the film obtained by the above method is preferably uniaxially or biaxially stretched by a roll method or a tenter method. The raw film is preferably stretched 1.1 times or more, more preferably 1.5 to 6 times, at least in a uniaxial direction.

  Considering that the above-mentioned FMD / FTD is 5 or more and 15 or less, it is particularly preferable that the uniaxial stretching is performed three times or more in the flow direction.

  After the melt-kneaded product is formed into a film, the film may be subjected to various surface treatments for the purpose of improving printability, laminate suitability, coating suitability, and the like. Examples of the surface treatment method include corona discharge treatment, plasma treatment, flame treatment, and acid treatment. Any method can be used, but the corona discharge treatment can be exemplified as a particularly preferable one because it can be continuously processed and can be easily installed in an existing film-forming facility and easy in processing.

  After adjusting the film obtained in this way to a desired width by slitting, cutting across the entire width by a cutting blade installed so as to be parallel to the width direction when viewed as a whole, or It is preferable to punch out with a square-shaped cutting blade installed so that at least one side is parallel to the width direction when viewed as a whole.

  Furthermore, in order to obtain a film having an R side by cutting, the shape of the cutting blade as viewed from the tip (portion contacting the film) is preferably a shape having irregularities such as a broken line and a wavy line. It is more preferable that it is a polygonal line shape as shown in FIG.

  Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited thereto.

[Measurement and evaluation method]
Measurements and evaluations shown in the examples were performed under the following conditions.

(1) Porosity (%)
The film was cut into a size of 30 mm × 40 mm and used as a sample. Using an electronic hydrometer (SD-120L manufactured by Mirage Trading Co., Ltd.), the specific gravity of the sample was measured in an atmosphere having a room temperature of 23 ° C. and a relative humidity of 65%. The measurement was performed three times, and the average value was defined as the specific gravity (ρ) of the film.

Next, the measured film was hot-pressed at 280 ° C. and 5 MPa, and then quenched with water at 25 ° C. to prepare a non-porous sheet. The specific gravity of the non-porous sheet was measured in the same manner as described above, and the average value was defined as the specific gravity (d) of the resin. From the specific gravity (ρ) of the film and the specific gravity (d) of the non-porous sheet, the value obtained by rounding off the first decimal place of the value obtained by the following formula was defined as the porosity.
Porosity (%) = [(d−ρ) / d] × 100
(2) Tensile elongation (%)
Using “TENSILON” (registered trademark) UCT-100 manufactured by Orientec Co., Ltd., the tensile elongation was measured in an atmosphere at a room temperature of 23 ° C. and a relative humidity of 65%. Specifically, a sample was cut into a strip shape having a length in the measurement direction of 100 mm and a length in the direction perpendicular to the measurement direction of 10 mm. The distance between the initial tensile chucks was 40 mm, the tensile speed was 200 mm / min, and JIS K- According to the method specified in 7127 (1999), the measurement was performed 5 times in the direction parallel to the R side of the film, and the value obtained by rounding off the first decimal place of the average value was taken as the tensile elongation.

(3) FMD / FTD
In the same manner as the tensile elongation, measurement is performed five times for each of the direction perpendicular to and parallel to the R side, the average value is taken as the tensile strength in each direction, and the tensile strength in the direction perpendicular to the R side. The ratio of the tensile strength in the direction parallel to the R side was FMD / FTD. In calculating FMD / FTD, the second decimal place was rounded off.

(4) Moisture permeability (g / (m ² · day)) was measured according to the method specified in JIS Z0208 (1976) with a thermostatic chamber set at 25 ° C. and 90% RH. Using the value of moisture permeability, the evaluation was made according to the following criteria.
A: 3,000 g / (m ² · day) or more B: 1,000 g / (m ² · day) or more and less than 3,000 g / (m ² · day) C: 300 g / (m ² · day) or more 1, 000g ^/ (m 2 · day) under ^{D: 300g / (m 2 ·} day) under moisture permeability a, B, C is good, a is the best among them.

(5) End face roughness The end face shape of the cross section of the film was observed with transmitted light at a magnification of 100 using a Leica DMLM manufactured by Leica Microsystems. When the roughness was severe and the roughness curve protruded from the observation screen at a magnification of 100, the observation was performed at a magnification of 10. The end face image obtained with a microscope was taken into a personal computer as an image, and then binarized into a black and white image at the film portion and the portion outside the film by adjusting the brightness of the image. Subsequently, two-dimensional coordinate data of the film end face portion was extracted by graph image automatic digitizing software Graphcel, and the end face roughness was calculated according to JISB 0601 (1994) using the extracted data as a roughness curve. In calculating the edge roughness, the first decimal place was rounded off.

(6) Disintegration In a 2,000 ml beaker containing 800 ml of water, four 100 mm square cut films obtained in each example or comparative example were put, and a rotational speed of 23 ° C. and 500 rpm with a magnetic stirrer. After 48 hours of stirring, the film was taken out of the beaker, and the number of pieces of the test piece after stirring was observed. Evaluation was performed based on the following criteria using the number of pieces of the test piece.
A: 16 sheets or more B: 13 sheets or more and 15 sheets or less C: 10 sheets or more and 12 sheets or less D: 6 sheets or more and 9 sheets or less E: 5 sheets or less The disintegration property is proportional to the number of pieces of the test piece. Excellent disintegration.

(7) Film thickness dial gauge thickness gauge (JIS B7503 (1997), UPAIGHT DIAL GAUGE (0.001 × 2 mm), No. 25, measuring element 5 mmφ flat type manufactured by PEACOCK) Five points were measured at intervals of 1 cm in the direction, and the average value was taken as the sheet thickness (μm) of the sheet.

[Biodegradable resin (A)]
(A1)
Polylactic acid resin (manufactured by NatureWorks, (trade name “Ingeo” (registered trademark) biopolymer 4032D))
(A2)
Block copolymer of polyethylene glycol and polylactic acid The above block polymer was produced by the following method.
62 parts by mass of polyethylene glycol having a number average molecular weight of 8,000, 38 parts by mass of L-lactic acid and 0.05 parts by mass of tin octylate are mixed and polymerized in a reaction vessel equipped with a stirrer at 160 ° C. for 3 hours in a nitrogen atmosphere. As a result, a block copolymer A2 having poly L-lactic acid segments having a number average molecular weight of 2,500 at both ends of polyethylene glycol having a number average molecular weight of 8,000 was obtained.
(A3)
Polybutylene adipate terephthalate resin (trade name “Ecoflex” (registered trademark) FBX7011 manufactured by BASF)
[Filler (B)]
(B1)
Calcium carbonate (manufactured by Maruo Calcium Co., Ltd., trade name Caltex R, average particle size: 2.8 μm
[Cut blade (C)]
The thing of the blade shape shown in FIG. 3 or FIG. 4 was used. Table 1 shows the pitch and height of each cutting blade.

[Production of film]
Example 1
The biodegradable resin and filler shown in Table 1 are supplied to a twin screw extruder with a vacuum vent with a cylinder diameter of 180 ° C. and a cylinder diameter of 180 ° C. at a rate of each mass% shown in the table, and the vacuum vent is degassed. Then, the mixture was melt-kneaded, homogenized and then pelletized to obtain a composition. The pellets of this composition were vacuum-dried at a temperature of 80 ° C. for 5 hours using a rotary drum type vacuum dryer.

  The dried pellets were supplied to a single screw extruder with a screw diameter of 60 mm at a cylinder temperature of 180 ° C. by an inflation method. Extruded upward in the form of bubbles at 0.0, air cooled by a cooling ring, taken up while being folded by a nip roll above the die, and wound into a roll. By adjusting the take-up speed, an unstretched film of 120 μm was obtained.

  The obtained unstretched film was stretched four times at a film temperature of 80 ° C. in the flow direction by a roll-type stretching machine. Subsequently, the film was heat treated for 1 second at a film temperature of 90 ° C. under a constant length and then cooled on a cooling roll to obtain a roll film sample having a thickness of 35 μm. The film temperature at this time was measured with an infrared radiation thermometer arranged at a position 30 cm perpendicular to the film surface.

  Subsequently, both ends of the obtained roll-shaped film sample were cut off with a slitter to a width of 100 mm, and continuously cut out over the entire width of 100 mm with a cutting blade shown in Table 1 every 100 mm of unwinding. A cut film having a 100 mm square shape when observed as a whole from a vertical direction was obtained. The physical properties of the obtained film were as shown in Table 1.

(Examples 2 to 5, 8 and Comparative Example 1)
A cut film having a 100 mm square shape when observed as a whole from a direction perpendicular to the film surface was obtained in the same manner as in Example 1 except that the composition and conditions described in Table 1 were used. The evaluation results of the obtained film are shown in Table 1.

(Examples 6 to 7)
The roll-shaped film sample obtained in Example 1 was punched out with the cutting blade shown in Table 1, and a cut film having a 100 mm square shape when observed as a whole from the direction perpendicular to the film surface was obtained. The evaluation results of the obtained film are shown in Table 1.

The shape of the cutting blade refers to the shape when observed as a whole, that is, the shape when the end face roughness is ignored.

  The present invention relates to a film having excellent disintegration properties. The film of the present invention can be preferably used for applications requiring degradability. Specifically, agricultural materials such as multi-films, forestry materials such as fumigation sheets, sanitary materials such as paper diapers, napkins and liners, various packaging materials such as plastic bags, garbage bags, foods, industrial products, For example, it can be preferably used.

a Film b Observation side c Observation direction d Straight line drawn on the film surface Example of R side (S side) that is not a true straight line 1
f Example 2 of R side (S side) which is not a true straight line
g Example 3 of R side (S side) that is not a true straight line
h Example 4 of R side (S side) that is not a true straight line
i Example 5 of R side (S side) which is not a true straight line
j Cut blade (linear shape)
k Cutting blade pitch l Cutting blade height m Cutting blade tip (part in contact with film)
n Cut blade (square shape)
o Side 1
p side 2

Claims (8)

  It includes a biodegradable resin, has at least one side (R side) having an end surface roughness of 10 μm or more and 50,000 μm or less, and has no side having an end surface roughness exceeding 50,000 μm. And a film.   The film according to claim 1, wherein the film has at least one side (S side) having an end surface roughness of 0 μm or more and less than 10 μm.   The film according to claim 1 or 2, wherein the shape when observed from a direction perpendicular to the film surface is a quadrangular shape.   The film according to any one of claims 1 to 3, wherein two opposing sides are R sides.   The film according to any one of claims 1 to 4, wherein a tensile elongation in a direction parallel to the R side is 5% or more and 60% or less.   When the tensile strength in the direction perpendicular to the R side is FMD and the tensile strength in the direction parallel to the R side is FTD, the ratio (FMD / FTD) is 5 or more and 15 or less. Item 6. The film according to any one of Items 1 to 5.   The film according to any one of claims 1 to 6, wherein the porosity is 10% or more and 80% or less.   The laminated body which bonds together the film and nonwoven fabric in any one of Claims 1-7.

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