JP2010253902A - Biodegradable laminated film for agriculture - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a biodegradable laminated film for agriculture which is excellent in tearing strength and flexibility. <P>SOLUTION: The biodegradable laminated film for agriculture has: a resin layer (A) made of a resin composition which contains 35 to 90 wt.% of the following aliphatic aromatic polyester resin (a) and 5 to 60 wt.% of at least either of the following aliphatic polyester resin (b) and the following aliphatic polyester resin (c); a resin layer (B) made of a resin composition which contains 50 to 100 wt.% of the resin (c); and a resin layer (C) made of a resin composition which contains 35 to 90 wt.% of the resin (a) and 5 to 60 wt.% of at least either of the resin (b) and the resin (c), in the order, wherein 1 to 49 wt.% of inorganic filler is contained in the laminated film. Herein, the resin (a) is an aliphatic aromatic polyester resin which has adipic acid unit, 1, 4-butane diol unit and terephthalic acid unit as molecular constitution unit, the resin (b) is an aliphatic polyester resin which has succinic acid unit and 1, 4-butane diol unit as molecular constitution unit, and the resin (c) is an aliphatic polyester resin which has succinic acid unit, 1, 4-butane diol unit and an adipic acid unit as molecular constitution unit. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a biodegradable laminated film used for agricultural materials such as a mulching film (also referred to as a multifilm), a tunnel film, a house film, a sun covering, a herbicidal sheet, a straw sheet, a germination sheet, and a vegetation mat.

In recent years, there has been a demand for film products that are rapidly decomposed after disposal and that do not accumulate in the natural environment, and various biodegradable resins are commercially available for such film products.
For example, Patent Document 1 proposes a film in which an aliphatic aromatic polyester resin and an aliphatic polyester resin are combined. However, such a composite material has a problem of deterioration of the appearance of the film due to instability during molding and uneven thickness of the film.

JP 2003-1704 A

  The present invention prevents instability at the time of molding and unevenness of the thickness of a molded product such as a film when an aliphatic aromatic polyester resin and an aliphatic polyester resin are compounded, and can be decomposed in a natural environment. The object is to provide a biodegradable laminated film that is excellent in molding stability and tear strength and flexibility when formed into a molded body, and is suitably used for various applications including agricultural multi-films. .

As a result of intensive studies to solve the above problems, the present inventors have completed the present invention.
That is, the gist of the present invention is as follows.
(1) 35 to 90% by weight of the following aliphatic aromatic polyester resin (a) and 5 to 60% by weight of at least one of the following aliphatic polyester resin (b) or the following aliphatic polyester resin (c) A resin layer (A) comprising the resin composition contained, a resin layer (B) comprising a resin composition comprising 50 to 100% by weight of the following aliphatic polyester resin (c), and the following aliphatic aromatic polyester resin ( A resin layer (C) comprising a resin composition containing 35 to 90% by weight of a) and at least one of the following aliphatic polyester resin (b) or the following aliphatic polyester resin (c): A biodegradable laminated film for agriculture, comprising 1 to 49% by weight of an inorganic filler in the laminated film,
Aliphatic aromatic polyester resin (a): Aliphatic aromatic polyester having adipic acid units, 1,4-butanediol units and terephthalic acid units as molecular structural units Aliphatic polyester based resin (b) Succinic as molecular structural units Aliphatic polyester having acid unit and 1,4-butanediol unit Aliphatic polyester resin (c): aliphatic polyester having succinic acid unit, 1,4-butanediol unit and adipic acid unit as molecular constituent units (2 ) The biodegradable laminated agricultural film according to (1), wherein the aliphatic polyester resin (b) or the aliphatic polyester resin (c) has a lactic acid unit as a molecular constituent unit;
(3) In the above (11) or (2), the elongation at break in the direction perpendicular to the resin flow (TD) is less than 400% as measured by a tensile test according to JIS K6781 of the aliphatic polyester resin (b). Agricultural biodegradable laminated film as described,
(4) The above-described (1) to (3), wherein the aliphatic polyester resin (c) has an elongation at break in the direction perpendicular to the resin flow (TD) of 400% or more as measured by a tensile test based on JIS K6781. The biodegradable laminated agricultural film according to any one of the above,
(5) The biodegradable laminated film for agriculture according to any one of (1) to (4), wherein the aliphatic polyester resin (b) is a polybutylene succinate resin,
(6) The aliphatic polyester-based resin (c) is a biodegradable laminated film for agriculture according to any one of the above (1) to (5), which is a polybutylene succinate adipate-based resin.

  ADVANTAGE OF THE INVENTION According to this invention, it is excellent in tear strength and a softness | flexibility, and the biodegradable laminated | multilayer film used suitably for the agricultural multifilm use etc. are provided.

Hereinafter, embodiments of the present invention will be described in detail.
The agricultural biodegradable laminated film of the present invention comprises 35 to 90% by weight of the following aliphatic aromatic polyester resin (a) and the following aliphatic polyester resin (b) or the following aliphatic polyester resin (c). Resin layer (A) composed of a resin composition containing 5 to 60% by weight of at least one, resin layer (B) composed of a resin composition containing 50 to 100% by weight of the following aliphatic polyester resin (c), and Resin containing 35 to 90% by weight of the following aliphatic aromatic polyester resin (a) and 5 to 60% by weight of at least one of the following aliphatic polyester resin (b) or the following aliphatic polyester resin (c) It is a biodegradable laminated film characterized by having a resin layer (C) made of the composition in this order.
In the resin layers (A) and (C), the aliphatic aromatic polyester resin (a) is less than 35% by weight, and at least one of the aliphatic polyester resin (b) and the following aliphatic polyester resin (c) When the content exceeds 60% by weight (the total amount when both aliphatic polyester-based resins (b) and (c) are contained), the tear strength is inferior. Further, the aliphatic aromatic polyester resin (a) exceeds 90% by weight, and at least one of the aliphatic polyester resin (b) and the following aliphatic polyester resin (c) (aliphatic polyester resin (b) ) And (c), if the total amount is less than 5% by weight, the slip property is deteriorated.
When the content of the aliphatic polyester resin (c) is less than 50% by weight in the resin layer (B), the tear strength of the laminated film is inferior. The content of the aliphatic polyester resin (c) is 50 to 100% by weight, and more preferably 60 to 100% by weight. In addition, the resin layer (B) may contain the aliphatic polyester-type resin (b).

<Aliphatic polyester resin (b), (c)>
In the present invention, the aliphatic polyester resin is preferably an aliphatic polyester resin mainly composed of an aliphatic diol unit and an aliphatic dicarboxylic acid unit. Here, the “main component” refers to 70 mol% or more of aliphatic diol units and aliphatic dicarboxylic acid units based on the total monomer units constituting the aliphatic polyester resin (100 mol%), preferably It means 80 mol% or more, more preferably 90 mol% or more.
Specific examples of the aliphatic polyester resin include a chain aliphatic and / or alicyclic diol unit represented by the following formula (1), and a chain represented by the following formula (2). It consists of alicyclic and / or alicyclic dicarboxylic acid units.

—O—R ¹ —O— (1)
[In the formula (1), R ¹ represents a divalent chain aliphatic hydrocarbon group and / or a divalent alicyclic hydrocarbon group. When copolymerized, two or more types of R ¹ may be contained in the resin. ]
^-OC-R 2 -CO- (2)
[In the formula (2), R ² represents a divalent chain aliphatic hydrocarbon group and / or a divalent alicyclic hydrocarbon group. When copolymerized, two or more types of R ² may be contained in the resin. ]

In the above formulas (1) and (2), “and” in the “divalent chain aliphatic hydrocarbon group and / or divalent alicyclic hydrocarbon group” means an aliphatic polyester resin. This means that both a divalent chain aliphatic hydrocarbon group and a divalent alicyclic hydrocarbon group may be contained in one molecule. Hereinafter, “chain aliphatic and / or alicyclic” may be simply abbreviated as “aliphatic”.
The aliphatic polyester resins (b) and (c) of the present invention each contain 1,4 butanediol unit as an essential component as a diol unit of the above formula (1). The 1,4 butanediol unit is 30 to 60 mol%, particularly 40 to 50 mol%, based on the whole monomer unit constituting the aliphatic polyester resin (b) or (c) (100 mol%). Is preferred. Although it does not specifically limit as diol units other than a 1, 4- butanediol unit, A C3-C10 aliphatic diol unit is preferable and a C4-C6 aliphatic diol unit is especially preferable. Specific examples include 1,3-propanediol and 1,4-cyclohexanedimethanol. Two or more kinds of diol components giving the aliphatic diol unit can be used.

In addition, each of the aliphatic polyester resins (b) and (c) contains a succinic acid unit as an essential component as the dicarboxylic acid unit of the above formula (2). The succinic acid unit preferably has a lower limit of usually 30 to 60 mol% based on the whole monomer unit constituting the aliphatic polyester resin (b) or (c) (100 mol%), particularly 35 It is preferably ˜50 mol%.
Furthermore, the aliphatic polyester-based resin (c) contains an adipic acid unit as an essential component as a dicarboxylic acid unit. The adipic acid unit is preferably 0.5 to 20 mol%, more preferably 1 to 15 mol%, based on the whole monomer unit constituting the aliphatic polyester resin (c) (100 mol%). Preferably there is. In addition, aliphatic polyester-type resin (b) does not contain an adipic acid unit substantially.
Although it does not specifically limit as dicarboxylic acid units other than a succinic acid unit and an adipic acid unit, A C2-C10 aliphatic dicarboxylic acid unit is preferable and a C4-C8 aliphatic dicarboxylic acid unit is especially preferable. Specific examples include suberic acid, sebacic acid, dodecanedioic acid and the like. Two or more kinds of dicarboxylic acid components giving the aliphatic dicarboxylic acid unit can be used.
Furthermore, the aliphatic polyester resin (b) or (c) may contain an aliphatic oxycarboxylic acid unit. Specific examples of the aliphatic oxycarboxylic acid that gives an aliphatic oxycarboxylic acid unit include lactic acid, glycolic acid, 2-hydroxy-n-butyric acid, 2-hydroxycaproic acid, 6-hydroxycaproic acid, 2-hydroxy-3, Examples thereof include 3-dimethylbutyric acid, 2-hydroxy-3-methylbutyric acid, 2-hydroxyisocaproic acid, and the like, or lower alkyl esters or intramolecular esters thereof. When optical isomers are present in these, any of D-form, L-form and racemic form may be used, and the form may be any of solid, liquid or aqueous solution. Of these, lactic acid or glycolic acid is particularly preferred. These aliphatic oxycarboxylic acids can be used alone or as a mixture of two or more.

  The amount of the aliphatic oxycarboxylic acid is preferably 0 to 30 mol% based on the whole monomer unit constituting the aliphatic polyester resin (b) or (c) (100 mol%), Furthermore, it is preferable that it is 0.01-20 mol%, and it is especially preferable that it is 0.01-10 mol%.

  In addition, the aliphatic polyester-based resin (b) or (c) is “trifunctional or higher aliphatic polyhydric alcohol”, “trifunctional or higher aliphatic polyhydric carboxylic acid or acid anhydride thereof” or “trifunctional or higher functional. It is preferable to copolymerize the “aliphatic polyvalent oxycarboxylic acid” because the melt viscosity of the resulting aliphatic polyester resin (b) or (c) can be increased.

  Specific examples of the trifunctional aliphatic polyhydric alcohol include trimethylolpropane and glycerin. Specific examples of the tetrafunctional aliphatic polyhydric alcohol include pentaerythritol. These may be used alone or in combination of two or more.

  Specific examples of the trifunctional aliphatic polyvalent carboxylic acid or its acid anhydride include propanetricarboxylic acid or its acid anhydride. Specific examples of the tetrafunctional polycarboxylic acid or its acid anhydride include cyclopentanetetracarboxylic acid or its acid anhydride. These may be used alone or in combination of two or more.

  In addition, the trifunctional aliphatic oxycarboxylic acid includes (i) a type having two carboxyl groups and one hydroxyl group in the same molecule, and (ii) one carboxyl group and two hydroxyl groups. Any type can be used. Specifically, malic acid or the like is preferably used. In addition, the tetrafunctional aliphatic oxycarboxylic acid includes (i) a type in which three carboxyl groups and one hydroxyl group are shared in the same molecule, and (ii) two carboxyl groups and two hydroxyl groups. And (iii) a type in which three hydroxyl groups and one carboxyl group are shared in the same molecule, and any type can be used. Specific examples include citric acid and tartaric acid. These may be used alone or in combination of two or more.

The amount of such a tri- or higher functional compound is preferably 0 to 5 mol% based on the total monomer constituting the aliphatic polyester resin (b) or (c) (100 mol%). In particular, it is preferably 0.01 to 2.5 mol%.
The aliphatic polyester resins (b) and (c) have substantially no aromatic ring in the molecule.

  The aliphatic polyester resin (b) or (c) used in the present invention can be produced by a known method. For example, a general method of melt polymerization such as an esterification reaction and / or a transesterification reaction between the aliphatic dicarboxylic acid component and the aliphatic diol component, and a polycondensation reaction under reduced pressure, It can also be produced by a known solution heating dehydration condensation method using a solvent. Among these, from the viewpoint of economy and simplicity of the production process, a method of production by melt polymerization performed in the absence of a solvent is preferable.

  The polycondensation reaction is preferably performed in the presence of a polymerization catalyst. The addition timing of the polymerization catalyst is not particularly limited as long as it is before the polycondensation reaction, and it may be added when the raw materials are charged, or may be added at the start of pressure reduction. The polymerization catalyst is generally a compound containing a group 1 to group 15 metal element excluding hydrogen and carbon in the periodic table. Specifically, at least one metal selected from the group consisting of titanium, zirconium, tin, antimony, cerium, germanium, zinc, cobalt, manganese, iron, aluminum, magnesium, calcium, strontium, sodium, and potassium. And compounds containing organic groups such as carboxylates, alkoxy salts, organic sulfonates and β-diketonate complexes, and inorganic compounds such as metal oxides and halides described above, or mixtures thereof.

  In these, the metal compound containing titanium, a zirconium, germanium, zinc, aluminum, magnesium, or calcium, and those mixtures are preferable, and especially a titanium compound or a germanium compound is preferable. In addition, when the catalyst is in a melted or dissolved state at the time of polymerization, the polymerization rate is increased. Therefore, the catalyst is preferably a liquid at the time of polymerization or a compound that is soluble in an ester low polymer or polyester.

  The amount of catalyst added in the case of using a metal compound as the polymerization catalyst, the lower limit is usually 5 ppm or more, preferably 10 ppm or more, and the upper limit is usually 30000 ppm or less, preferably 1000 ppm or less, as the amount of metal relative to the produced polyester. More preferably, it is 250 ppm or less, Especially preferably, it is 130 ppm or less. If too much catalyst is used, it is not only economically disadvantageous but also lowers the thermal stability of the polymer. Conversely, if it is too little, the polymerization activity is lowered, and as a result, the polymer decomposes during polymer production. Is more likely to be triggered.

  The lower limit of the esterification reaction and / or transesterification reaction temperature between the dicarboxylic acid component and the diol component is usually 150 ° C or higher, preferably 180 ° C or higher, and the upper limit is usually 260 ° C or lower, preferably 250 ° C or lower. The reaction atmosphere is usually an inert gas atmosphere such as nitrogen or argon. The reaction pressure is usually normal pressure to 10 kPa, and normal pressure is preferred. The reaction time is usually 1 hour or longer, and the upper limit is usually 10 hours or shorter, preferably 4 hours or shorter.

In the subsequent polycondensation reaction, the lower limit of the pressure is usually 0.001 × 10 ³ Pa or more, preferably 0.01 × 10 ³ Pa or more, and the upper limit is usually 1.4 × 10 ³ Pa or less, preferably 0. The degree of vacuum is 4 × 10 ³ Pa or less. At this time, the lower limit of the reaction temperature is usually 150 ° C. or higher, preferably 180 ° C. or higher, and the upper limit is usually 260 ° C. or lower, preferably 250 ° C. or lower. The lower limit of the reaction time is usually 2 hours or more, and the upper limit is usually 15 hours or less, preferably 10 hours or less.

  As a reaction apparatus for producing the aliphatic polyester-based resin (b) or (c), a known vertical or horizontal stirred tank reactor can be used. For example, melt polymerization is carried out in two stages of esterification and / or transesterification and reduced pressure polycondensation using the same or different reactors, and a vacuum pump and a reactor are used as the reduced pressure polycondensation reactor. A method using a stirred tank reactor equipped with a evacuating pipe for decompression to be connected can be mentioned. In addition, a condenser is connected between the vacuum exhaust pipe connecting the vacuum pump and the reactor, and the volatile components and unreacted monomers generated during the condensation polymerization reaction are recovered by the condenser. Is preferred.

  In the present invention, the molar ratio of the diol component and the dicarboxylic acid component for obtaining the aliphatic polyester resin (b) or (c) having the desired degree of polymerization is different depending on the purpose and the kind of raw material. The amount of the diol component relative to 1 mol of the acid component is usually at least 0.8 mol, preferably at least 0.9 mol, and the upper limit is usually at most 1.5 mol, preferably at most 1.3 mol, especially Preferably it is 1.2 mol or less. In addition, a urethane bond, an amide bond, a carbonate bond, an ether bond, or the like can be introduced into the aliphatic polyester resin (b) or (c) as long as the biodegradability is not affected.

  The melt flow rate (MFR) of the aliphatic polyester resin (b) or (c) used in the present invention is preferably 0.1 g / 10 to 100 g / 10 min when measured at 190 ° C. and a load of 2.16 kg. Further, 0.1 to 50 g / 10 min is preferable, and 0.1 to 30 g / 10 min is particularly preferable.

The polyester resin (b) preferably has an elongation at break in the direction perpendicular to the resin flow (TD) measured by a tensile test according to JIS K6781 of less than 400%, more preferably less than 200%. In particular, it is preferably less than 160%.
The melting point of the polyester resin (b) is preferably 100 ° C. or higher. Moreover, it is preferable that it is 130 degrees C or less.
The polyester resin (c) preferably has a breaking elongation in the direction perpendicular to the resin flow (TD) measured by a tensile test in accordance with JIS K6781 of 400% or more, and more preferably 600% or more. In particular, it is preferably 700% or more.
It is preferable that the elongation at break of (c) of the aliphatic polyester-based resin is the above value since the mechanical properties, particularly the tear strength, of the laminated film can be improved.
The melting point of the polyester resin (C) is preferably 80 ° C. or higher. Moreover, it is preferable that it is 100 degrees C or less.

  As the aliphatic polyester resin (b), for example, a polybutylene succinate polyester resin such as GSPla (registered trademark) AZ91TN manufactured by Mitsubishi Chemical Corporation is preferably used. As the aliphatic polyester resin (c), for example, polybutylene succinate adipate polyester resin such as GSPla (registered trademark) AD92WN manufactured by Mitsubishi Chemical Corporation is preferably used.

<Aliphatic aromatic polyester resin (a)>
The aliphatic aromatic polyester-based resin (a) includes an aliphatic dicarboxylic acid unit, an aromatic dicarboxylic acid unit, and a chain aliphatic and / or alicyclic diol unit, and an aromatic dicarboxylic acid unit. Is 5 to 60 mol based on the total amount of the aliphatic dicarboxylic acid unit and the aromatic dicarboxylic acid unit (100 mol%). Specifically, for example, an aliphatic diol unit represented by the following formula (3), an aliphatic dicarboxylic acid unit represented by the following formula (4), and an aroma represented by the following formula (5) Group dicarboxylic acid unit as an essential component.

—O—R ³ —O— (3)
[In the formula (3), R ³ represents a divalent chain aliphatic hydrocarbon group and / or a divalent alicyclic hydrocarbon group, and is not limited to one type when copolymerized. ]
—OC—R ⁴ —CO— (4)
[In the formula (4), R ⁴ represents a direct bond or a divalent chain aliphatic hydrocarbon group and / or a divalent alicyclic hydrocarbon group, and is 1 when copolymerized. It is not limited to species. ]
—OC—R ⁵ —CO— (5)
[In Formula (5), R ⁵ represents a divalent aromatic hydrocarbon group, and is not limited to one type when copolymerized. ]

  The diol component giving the diol unit of the formula (3) is usually one having 2 to 10 carbon atoms, such as ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,4-cyclohexanedi Methanol etc. are mentioned. Among these, diols having 2 to 4 carbon atoms are preferable, ethylene glycol and 1,4-butanediol are more preferable, and 1,4-butanediol is particularly preferable.

  The dicarboxylic acid component that gives the dicarboxylic acid unit of the formula (4) usually has 2 to 10 carbon atoms, and examples thereof include succinic acid, adipic acid, suberic acid, sebacic acid, and dodecanedioic acid. Among these, succinic acid or adipic acid is preferable.

  Examples of the aromatic dicarboxylic acid component that gives the aromatic dicarboxylic acid unit of the formula (5) include terephthalic acid, isophthalic acid, naphthalenedicarboxylic acid and the like, among which terephthalic acid and isophthalic acid are preferable, and terephthalic acid is particularly preferable. preferable. Moreover, aromatic dicarboxylic acid in which a part of the aromatic ring is substituted with a sulfonate is exemplified. Two or more types of aliphatic dicarboxylic acid components, aliphatic diol components, and aromatic dicarboxylic acid components can be used.

  The aliphatic aromatic polyester resin (a) in the present invention may contain an aliphatic oxycarboxylic acid unit. Specific examples of the aliphatic oxycarboxylic acid that gives an aliphatic oxycarboxylic acid unit include lactic acid, glycolic acid, 2-hydroxy-n-butyric acid, 2-hydroxycaproic acid, 6-hydroxycaproic acid, 2-hydroxy-3, Examples include 3-dimethylbutyric acid, 2-hydroxy-3-methylbutyric acid, 2-hydroxyisocaproic acid, or a mixture thereof. Furthermore, these lower alkyl esters or intramolecular esters may be used. When optical isomers are present in these, any of D-form, L-form and racemic form may be used, and the form may be any of solid, liquid or aqueous solution. Among these, lactic acid or glycolic acid is preferable. These aliphatic oxycarboxylic acids can be used alone or as a mixture of two or more.

  The amount of the aliphatic oxycarboxylic acid is preferably 0 to 30 mol%, more preferably 0.01 to 20 mol% in all the constituent components constituting the aliphatic aromatic polyester resin (a). Is preferred. The aliphatic aromatic polyester resin (a) can be produced by the same production method as the aliphatic polyester resin (b) or (c).

  The melt flow rate (MFR) of the aliphatic aromatic polyester-based resin (a) used in the present invention is preferably 0.1 to 100 g / 10 minutes when measured at 190 ° C. and a 2.16 kg load, Further, it is preferably 0.1 to 50 g / 10 minutes, and particularly preferably 0.1 to 30 g / 10 minutes.

<Inorganic filler>
The biodegradable laminated film of the present invention contains an inorganic filler. Examples of such inorganic fillers include silica, mica, talc, titanium oxide, calcium carbonate, diatomaceous earth, allophane, bentonite, potassium titanate, zeolite, sepiolite, smectite, kaolin, kaolinite, glass, limestone, carbon, wollastonite. , Calcined perlite, silicates such as calcium silicate and sodium silicate, hydroxides such as aluminum oxide, magnesium carbonate and calcium hydroxide, ferric carbonate, zinc oxide, iron oxide, aluminum phosphate and barium sulfate Of these, talc and calcium carbonate are preferred. These may be used alone or in combination of two or more.

The blending amount of the inorganic filler is preferably 1 to 49% by weight in the biodegradable laminated film. When the blending amount is less than 1% by weight, the blending effect of the inorganic filler is small. When the blending amount exceeds 49% by weight, the moldability, slip property, physical properties, etc. of the film may be lowered.
In particular, the resin layers (A) and (C) contain an inorganic filler, preferably talc, in an amount of 0.5 to 10% by weight, preferably 1 to 5% by weight, for improving the slipperiness of the laminated film. Therefore, it is preferable.

<Various additives>
The biodegradable laminated film of the present invention can further contain various conventionally known additives. Examples of the additive include a crystal nucleating agent, an antioxidant, an antiblocking agent, a slip agent, an ultraviolet absorber, a light resistance agent, a plasticizer, a heat stabilizer, a colorant, a flame retardant, a release agent, an antistatic agent, Examples include antifogging agents, surface wetting improvers, incineration aids, pigments, lubricants, dispersants, various surfactants, and hydrolysis inhibitors. These may be used alone or in combination of two or more. Among these, it is particularly preferable to add a slip agent and an antiblocking agent.

  Examples of the slip agent include unsaturated fatty acid amides and unsaturated fatty acid bisamides composed of unsaturated fatty acids having 6 to 30 carbon atoms, and erucic acid amide and erucic acid bisamide are preferred.

Examples of the anti-blocking agent include saturated fatty acid amides having 6 to 30 carbon atoms, or saturated fatty acid bisamides (for example, stearic acid amide and stearic acid bisamide), methylol amide, ethanol amide, natural silica, synthetic silica, synthetic zelite, and talc. It is done.
As a colorant, a colorant usually used for agricultural multi-films such as carbon black and titanium oxide can be used. The colorant may be blended in each resin layer, or may be blended in a specific layer, for example, the resin layer (B).

  Specific examples of the light stabilizer include bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate, bis (1,2,2,6,6-pentamethyl-4-piperidyl) sebacate, Bis (1-octyloxy-2,2,6,6-tetramethyl-4-piperidyl) sebacate, 2- (3,5-di-t-butyl-4-hydroxyphenyl) -2-n-butyl-bis (2,2,6,6-tetramethyl-4-piperidyl) malonate, 2- (3,5-di-tert-butyl-4-hydroxyphenyl) -2-n-butyl-bis (1,2,2 , 6,6-pentamethyl-4-piperidyl) malonate, 2- (3,5-di-t-butyl-4-hydroxybenzyl) -2-n-butyl-bis (2,2,6,6-tetramethyl) -4-piperidyl) malonate, 2- 3,5-di-t-butyl-4-hydroxybenzyl) -2-n-butyl-bis (1,2,2,6,6-pentamethyl-4-piperidyl) malonate, tetrakis (2,2,6, 6-tetramethyl-4-piperidyl) -1,2,3,4-butanetetracarboxylate, tetrakis (1,2,2,6,6-pentamethyl-4-piperidyl) -1,2,3,4 Butanetetracarboxylate, mixed (2,2,6,6-tetramethyl-4-piperidyl / tridecyl) -1,2,3,4-butanetetracarboxylate, mixed (1,2,2,6, 6-pentamethyl-4-piperidyl / tridecyl) -1,2,3,4-butanetetracarboxylate, mixed {2,2,6,6-tetramethyl-4-piperidyl / β, β, β ′, β '− Tetramethyl-3,9- [2,4,8,10-tetraoxaspiro [5.5] undecane] diethyl} -1,2,3,4-butanetetracarboxylate, mixed {1,2,2 , 6,6-pentamethyl-4-piperidyl / β, β, β ′, β′-tetramethyl-3,9- [2,4,8,10-tetraoxaspiro [5.5] undecane] diethyl}- 1,2,3,4-butanetetracarboxylate, 1,2-bis (3-oxo-2,2,6,6-tetramethyl-4-piperidyl) ethane, 1- (3,5-di-t -Butyl-4-hydroxyphenyl) -1,1-bis (2,2,6,6-tetramethyl-4-piperidyloxycarbonyl) pentane, poly [1-oxyethylene (2,2,6,6-tetra Methyl-1,4-piperidyl) oxys Sinyl], poly [2- (1,1,4-trimethylbutylimino) -4,6-triazinediyl- (2,2,6,6-tetramethyl-4-piperidyl) iminohexamethylene- (2,2 , 6,6-tetramethyl-4-piperidyl) imino], N, N′-bis (3-aminopropyl) ethylenediamine-2,4-bis [N-butyl-N- (2,2,6,6- Tetramethyl-4-piperidyl) amino] -6-chloro-1,3,5-triazine condensate and its N-methyl compound, succinic acid and 1- (2-hydroxyethyl) -4-hydroxy-2,2, Polycondensate with 6,6-tetramethylpiperidine, poly [{6-((1,1,3,3-tetramethylbutyl) amino-1,3,5-triazine 2,4-diyl} {(2 , 2,6,6-tetramethyl-4-piperidyl) imino} Kisamechiren {((2,2,6,6-tetramethyl-4-piperidyl) imino}], and the like.

  Among these, poly [{6-((1,1,3,3-tetramethylbutyl) amino-1,3,5-triazine 2,4-diyl} {(2,2,6,6-tetra Methyl-4-piperidyl) imino} hexamethylene {((2,2,6,6-tetramethyl-4-piperidyl) imino}] is particularly preferred.

  As the UV absorber, among the UV absorbers such as benzophenone, benzotriazole, salicylic acid, and cyanoacrylate, a benzotriazole UV absorber is preferable. Specifically, 2- [5-chloro (2H ) -Benzotriazol-2-yl] -4-methyl 6- (tert-butyl) phenol, 2- [2-hydroxy-3,5-bis (α, α-dimethylbenzyl) phenyl] -2H-benzotriazole, 2- (4,6-diphenyl-1,3,5-triazin-2-yl) -5-hexyloxy-phenol.

  Antioxidants include BHT, 2,2′-methylenebis (4-methyl-6-tert-butylphenol), pentaerythritol tetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate]. 3,3 ′, 3 ″, 5,5 ′, 5 ″ -hexa-tert-butyl-α, α ′, α ″-(mesitylene-2,4,6-triyl) tri-p-cresol, octadecyl- 3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate, 1,3,5-tris [(4-tert-butyl-3-hydroxy-2,6-xylyl) methyl] -1, 3,5-triazine-2,4,6 (1H, 3H, 5H) -trione, 1,3,5-tris (3,5-di-tert-butyl-4-hydroxybenzyl) -1,3,5 Triazine-2,4,6 (1H, 3H, 5H) -trione, calcium diethylbis [{3,5-bis (1,1-dimethylethyl) -4-hydroxyphenyl} methyl] phosphonate, bis (2, 2′-dihydroxy-3,3′-di-tert-butyl-5,5′-dimethylphenyl) ethane, N, N′-hexane-1,6-diylbis [3- (3,5-di-tert- Butyl) -4-hydroxyphenyl] propionamide, n-octadecyl 3- (3 ′, 5′-di-t-butyl-4′-hydroxyphenyl) propionate and other hindered phenol antioxidants, tridecyl phosphite , Diphenyldecyl phosphite, tetrakis (2,4-di-tert-butylphenyl) [1,1-biphenyl] -4,4′-diylbisphosphine Phosphorus such as ionite, bis [2,4-bis (1,1-dimethylethyl) -6-methylphenyl] ethyl ester phosphorous acid, bis (2,4-di-tert-butylphenyl) pentaerythritol diphosphite Antioxidants, lactone antioxidants such as 3-hydroxy-5,7-di-tert-butyl-furan-2-one and xylene reactive organisms, dilauryl thiodipropionate, distearyl thiodipropio Examples thereof include sulfur-based antioxidants such as nates and mixtures of two or more of these, among which hindered phenol-based antioxidants are preferably used.

  Preferred hindered phenol antioxidants are ADK STAB AO-50 (manufactured by ADEKA), Irganox 3790, Irganox 1330, Irganox 1010, Irganox 1076, Irganox 3114, Irganox 1425WL, Irganox 1098, Irganox. HP2225FL, Irganox HP2341, Irgaphos XP-30 (manufactured by Ciba Specialty Chemicals Co., Ltd.), and Sumilizer BBM-S (Sumitomo Chemical Co., Ltd.) are used. The most preferred antioxidant is Irganox 3790 (1,3,5-tris [(4-tert-butyl-3-hydroxy-2,6-xylyl) methyl] -1,3,5-triazine-2,4, 6 (1H, 3H, 5H) -trione), Irganox 1330 (3,3 ′, 3 ″, 5,5 ′, 5 ″ -hexa-tert-butyl-α, α ′, α ″-(mesitylene-2) , 4,6-triyl) tri-p-cresol).

Examples of the stabilizer include fatty acid metal salts. The fatty acid component of the fatty acid metal salt is a normal carboxylic acid having a carboxyl group and having 6 to 30 carbon atoms, which may be linear or branched, and has only an unsaturated bond or an unsaturated bond. Also good. Specific examples of fatty acids include caproic acid, caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, arachidic acid, behenic acid, montanic acid, palmitoleic acid, oleic acid, eicosenoic acid, erucic acid, elaidic acid , Trans 11 eicosenoic acid, trans 13 docosenoic acid, linoleic acid, linolenic acid, ricinoleic acid, erucic acid and the like.
On the other hand, as the metal atom, atoms of 1A, 2A, 2B and 3B groups of the periodic table are preferable. Preferable examples include sodium, potassium, calcium, magnesium, barium, aluminum, zinc and the like.
Specific examples of the aliphatic metal salt include calcium stearate, magnesium stearate, barium stearate, aluminum stearate, zinc stearate, calcium laurate, magnesium laurate, aluminum laurate, sodium montanate and the like. These may be used alone or in combination of two or more. Among these, calcium stearate, magnesium stearate, aluminum stearate, calcium laurate, magnesium laurate and aluminum laurate are preferable.
The antifogging agent may be blended in the entire laminated film, but may be blended only in the inner layer (the layer that becomes the inner side when spread as an agricultural film), and contains the antifogging agent on the inner layer surface. A coating film may be provided. Specifically, the antifogging agent used is preferably an ester surfactant of a saturated or unsaturated aliphatic carboxylic acid having 4 to 20 carbon atoms and a polyhydric alcohol.
Examples of the dispersant include ester waxes such as montan wax.
The addition amount of these additives is usually 0.001 to 10% by weight, preferably 0.02 to 5% by weight in the laminated film.
<Other ingredients>
The resin composition of the present invention includes biodegradable resins and natural products such as polylactic acid, polycaprolactone, polyamide, polyvinyl alcohol, cellulose ester and the like, starch, cellulose, paper, wood, and the like as long as the effects of the present invention are not impaired. Fine powders of animal / plant substances such as flour, chitin / chitosan, coconut shell powder, walnut shell powder, or a mixture thereof can be blended.

<Method for forming laminated film>
Although the thickness of the biodegradable laminated film of the present invention varies depending on the use, it is preferably about 10 μm to 200 μm, and the ratio of the thicknesses of the resin layers (A), (B) and (C) is not particularly limited. About 8/1 to 3/4/3 is preferable.
As a kneading method of the resin composition constituting each layer of the biodegradable laminated film of the present invention, a general method can be used as a kneading method of the resin composition. Specifically, pellets, powders, solid strips, etc. are dry-mixed with a Henschel mixer or ribbon mixer, and then mixed into a known melt-kneader such as a single or twin screw extruder, Banbury mixer, kneader, or mixing roll. It can be supplied and melt kneaded. A method of forming a laminated film from a resin composition constituting each layer is formed by coextrusion molding in which a film laminated with a multilayer T die is cooled and solidified by a cast roll using a plurality of extruders, or by a multilayer inflation molding machine. The method to do is suitable.
The laminated film of the present invention can be suitably used for agricultural materials such as a mulching film (also referred to as a mulch film), a tunnel film, a house film, a sun covering, a herbicidal sheet, a straw sheet, a germination sheet, and a vegetation mat.

EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited to these.
The evaluation was performed by the following method.
(1) Tear strength Using a Elmendorf tear tester manufactured by Toyo Seiki Co., Ltd. at 23 ° C, the tear strength in the MD direction (machine forming direction) of a sample in which 8 laminated films are stacked is measured and evaluated according to the following criteria: did.
◎: Tear strength is 0.8 N or more ○: Tear strength is 0.5 or more and less than 0.8 N △: Tear strength is less than 0.5 N (2) Slip property When producing a laminated film, coextrusion from an inflation molding machine Based on the resistance required when the two laminated films were peeled off with the thumb and index finger, the following criteria were used.
○: Can be easily peeled off with fingertip force.
Δ: It can be peeled off with the force of the fingertip, but is heavy.
×: Cannot be peeled off with the force of the fingertip.
(Examples 1-7, Comparative Examples 1-6)
Aliphatic aromatic polyester-based resin (a), aliphatic polyester-based resin (b), aliphatic polyester-based resin (c), and inorganic filler are blended in the composition (% by weight) shown in Table 1, and biaxial 20 μm in which the resin layer (A) / resin layer (B) / resin layer (C) were laminated in the order of melt-kneading and compounding into pellets by molding at 160 ° C. using a three-layer inflation molding machine. A thick three-layer laminated film was obtained. However, the shaping | molding of Examples 1 and 7 and Comparative Examples 1 and 2 was implemented at 150 degreeC.

  The agricultural biodegradable laminated film of the present invention is excellent in physical properties such as tearing strength and is not easily damaged. A mulching film (also called a multifilm), a tunnel film, a house film, a sun covering, a herbicidal sheet, a straw sheet, and a germination. It can be suitably used for agricultural materials such as sheets and vegetation mats.

Claims (6)

Resin containing 35 to 90% by weight of the following aliphatic aromatic polyester resin (a) and 5 to 60% by weight of at least one of the following aliphatic polyester resin (b) or the following aliphatic polyester resin (c) A resin layer (A) comprising the composition, a resin layer (B) comprising a resin composition containing 50 to 100% by weight of the following aliphatic polyester resin (c), and the following aliphatic aromatic polyester resin (a) A resin layer (C) composed of a resin composition containing 35 to 90% by weight and at least one of the following aliphatic polyester resin (b) or the following aliphatic polyester resin (c) in this order: An agricultural biodegradable laminated film comprising 1 to 49% by weight of an inorganic filler in the laminated film.
Aliphatic aromatic polyester resin (a): Aliphatic aromatic polyester having adipic acid units, 1,4-butanediol units and terephthalic acid units as molecular structural units Aliphatic polyester resin (b): As molecular structural units Aliphatic polyester having succinic acid unit and 1,4-butanediol unit Aliphatic polyester resin (c): Aliphatic polyester having succinic acid unit, 1,4-butanediol unit and adipic acid unit as molecular constituent units   The agricultural biodegradable laminated film according to claim 1, wherein the aliphatic polyester resin (b) or the aliphatic polyester resin (c) has a lactic acid unit as a molecular constituent unit.   The agricultural biodegradation according to claim 1 or 2, wherein the aliphatic polyester resin (b) has an elongation at break in the direction perpendicular to the resin flow (TD) of less than 400% as measured by a tensile test in accordance with JIS K6781. Laminated film.   The elongation at break in the direction perpendicular to the resin flow (TD) measured by a tensile test in accordance with JIS K6781 of the aliphatic polyester-based resin (c) is 400% or more. Biodegradable laminated film for agriculture.   The biodegradable laminated film for agriculture according to any one of claims 1 to 4, wherein the aliphatic polyester resin (b) is a polybutylene succinate resin.   The agricultural biodegradable laminated film according to any one of claims 1 to 5, wherein the aliphatic polyester resin (c) is a polybutylene succinate adipate resin.