JP2003292641A - Film made of biodegradable resin - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a film made of a biodegradable resin which does not tear in spreading and tensioning and in use when used as a sheet for the insect fumigation of wood and an agricultural multipurpose film, furthermore has heat resistance to excel in moldability in film molding, and has no problem of take-up properties and in leaving sheets in a superposed state when formed into the sheets of a specified size. <P>SOLUTION: The film made of a biodegradable resin is obtained by adding 0.1-10 pts.wt. inorganic filler and 0.01-1 pt.wt. fatty acid amide to the biodegradable resin, has a tensile elongation at break of 400-1,200%, an Elmendorf tear strength of ≥200 N/cm, and a coefficient of kinetic friction between the films of 0.1-0.7. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a biodegradable resin film formed by calendering, extrusion, inflation, etc., which is decomposed in the natural environment such as soil. It is used for sheet and agricultural mulch film.

[0002]

2. Description of the Related Art When disposing of various plastic products using general synthetic resins, there is a problem that harmful gas is generated by incineration, and when discarded, they are not decomposed for a long time. The problem of destroying the natural environment is becoming more serious every year.
Therefore, in recent years, various biodegradable resins that are easily decomposed in a short time by the action of microorganisms existing in soil or sea have been proposed, and various products using them have been developed and put into practical use. .

Agricultural mulching film is an agricultural film used for covering the surface of soil such as fields to promote the growth of plants and to control weeds. Such a film is removed and discarded when vegetables or the like grow or are harvested. However, it takes a lot of labor and time to collect the discarded film, which causes a problem of increasing the production cost of crops and the like. Further, as a method for treating the recovered film, incineration is generally used, but it causes environmental problems such as dioxins. Therefore, it is necessary to use a biodegradable resin sheet that can be plowed into the soil on the spot where it is used without requiring labor such as recovery and is decomposed with time.

In addition, when carrying out the import and export of various large products, a wood pallet is used in the transportation by a forklift. In many cases, harmful pests are lurking in this wood pallet, and if the wood pallet is directly transported to other countries, it will result in the migration of these pests to other countries, leading to the problem of destroying the natural environment of the country. There is. In particular, pine worms, which are beetles such as pine weevil, pine beetle, pine beetle, etc., cause a great deal of damage to the growth of pine trees, especially for imported products transported from Japan and the United States. Problems such as the mixture of such pine eaters in wood pallets are often raised by various countries around the world, and disinfection of the wood is desired.

In many cases, the extermination of such pests is carried out by stacking timber immediately after being cut out in the field, covering it with a resin sheet to hermetically surround it, and fumigating an insecticide.
Fumigation of the pests lasts for a certain period of time, such as one month or more, but the fumigation sheet is discarded when the chemical fumigation is completed. Chemical fumigation is often incinerated because it is carried out in forests where timber has been cut down, but in view of today's environmental problems, incineration is not preferable, so biodegradable resin is used. There is a growing demand for fumigation sheets.

What are used today as such biodegradable resins are, for example, aliphatic polyesters and their derivatives such as polylactic acid, polycaprolactone, polybutylene succinate, polyhydroxyvalerate, etc. It is a low melting point resin. Therefore, when using these biodegradable resins to form sheets, films, etc., extrusion molding, injection molding, inflation molding,
It is made by blow molding or the like.

However, conventionally, a film formed from the above-mentioned biodegradable resin is easy to tear during spreading and during use, and it is difficult to use it as a sheet for wood fumigation or an agricultural mulch film. In addition, the film using these resins has stickiness on the surface, and when wound in a roll shape or stacked in a sheet shape,
The films adhered to each other and were difficult to handle when used.

[0008]

DISCLOSURE OF THE INVENTION The present invention solves the above problems by ensuring biodegradability, and when used as a sheet for fumigation of wood or an agricultural mulch film, does not tear during spreading or use, and further It is an object of the present invention to provide a biodegradable resin film which has heat resistance and is excellent in moldability during film molding, and has no wind-up property and does not pose a problem when stacked into a sheet having a certain size.

[0009]

That is, in the biodegradable resin film according to the invention of claim 1, the biodegradable resin contains 0.1 to 10 parts by weight of an inorganic filler and 0.0 to 10 parts by weight of fatty acid amide.
Addition of 1 to 1 part by weight, tensile breaking elongation is 400 to 12
00%, Elemendorff tear strength is 200 N / cm or more, and the coefficient of dynamic friction between biodegradable resin films is 0.1.
It is characterized by being ~ 0.7.

According to a second aspect of the present invention, in the biodegradable resin film according to the first aspect, the main component of the biodegradable resin is
It is a copolymer resin of at least 1,4-butanediol and terephthalic acid.

According to a third aspect of the present invention, in the biodegradable resin film according to the second aspect, a copolymer resin of at least 1,4-butanediol and terephthalic acid, which is a main component of the biodegradable resin, is used. In addition to the above, another biodegradable resin is added.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION The biodegradable resin film of the present invention has a tensile breaking elongation of 400 to 1200% according to the measurement of JIS K 7121. It can be used as a film with good workability during stretching. If the tensile elongation at break is less than 400%, it tends to be broken due to excessive pulling force at the time of spreading, which makes it difficult to use. On the other hand, if the tensile elongation at break exceeds 1200%, there is a possibility that it will be excessively elongated and the workability for spreading will be reduced, and that when it is used as an agricultural mulch film, it may become entangled with the machine when it is plowed into the soil.

[0013] Further, since the Elementmendorf tear strength according to the measurement of JIS K 7128-2 is 200 N / cm or more, holes formed in the film at the time of molding or spreading of the film, or punched as an agricultural mulch film. Even if there are holes in the film, the film is less likely to tear from that part due to the tensile load.

Furthermore, the coefficient of kinetic friction between the biodegradable resin films according to the measurement of JIS K 7125 is 0.1.
Since it is ˜0.7, it is a biodegradable resin film that does not cause any trouble when wound on a roll or when a plurality of sheets having a certain length are stacked. If the coefficient of kinetic friction is less than 0.1, the film will slip sideways in a state of being wound on a roll, the winding will be broken, or it will be impossible to fold and cut sheets cut into a certain length. On the other hand, if the coefficient of dynamic friction exceeds 0.7, the films will stick to each other, making it difficult to unwind the roll-wound film, and the workability will decrease due to sticking, or the film will wind around the coating and break. Is likely to occur.

In the biodegradable film of the present invention, since the biodegradable resin itself is inferior in slip property and heat resistance to ordinary vinyl chloride film and the like, an inorganic material is used in order to improve slip property and heat resistance. 0.1 to 10 parts by weight of filler and 0.01 to 1 part by weight of fatty acid amide are added. If the amount of the inorganic filler added is less than 0.1 parts by weight, the dynamic friction coefficient becomes large, which causes a problem of slip property, and further, the heat resistance is poor and the moldability is deteriorated.
If it exceeds 0 parts by weight, the tensile strength of the film will decrease. If the amount of the fatty acid amide added is less than 0.01, there is a problem in terms of slip properties and heat resistance, and if it exceeds 1 part by weight, the resin becomes slippery during molding, making it difficult to form a film. Will end up.

As the inorganic filler, talc, mica, silica, hydrotalcite, feldspar, titanium oxide, zinc oxide, calcium carbonate, magnesium hydroxide, aluminum hydroxide or the like can be used alone or in combination. .

As the fatty acid amide, erucic acid amide,
Palmitic acid amide, oleic acid amide, stearic acid amide, methylenebisstearic acid amide, ethylenebisstearic acid amide, ethylenebisoleic acid amide, ethylenebiserucic acid amide and the like can be used alone or in combination.

As the biodegradable resin used in the present application, it is preferable to use a biodegradable resin resin composed of at least a copolymer resin of 1,4-butanediol and terephthalic acid. For example, polybutylene adipate terephthalate which is a copolymer resin of 1,4-butanediol, terephthalic acid and adipic acid, and polybutylene succinate terephthalate which is a copolymer resin of 1,4-butanediol, terephthalic acid and succinic acid. Etc. can be preferably used.

Further, for the purpose of modifying the biodegradability,
If desired, other biodegradable resin may be added to the biodegradable resin made of a copolymer resin of at least 1,4-butanediol and terephthalic acid. The blending ratio is preferably less than 50 parts by weight when 100 parts by weight of the biodegradable resin is used. When the addition amount of other biodegradable resin exceeds 50 parts by weight, the tensile breaking elongation value of the present invention,
Elmendorf tear strength and dynamic friction coefficient must not be satisfied. As the other biodegradable resin, those which are more excellent in biodegradability than the biodegradable resin made of at least a copolymer resin of 1,4-butanediol and terephthalic acid are preferable. For example, polybutylene succinate, polybutylene succinate adipate, polylactic acid, polybutylene succinate carbonate, polycaprolactone and the like can be used alone or in combination.

Further, in order to improve weather resistance, an ultraviolet absorber may be added to the biodegradable resin used in the present invention. Examples thereof include salicylic acid ester, benzotriazole, hydroxybenzophenone, and acrylonitrile-substituted products. These ultraviolet absorbers can be used alone or in admixture of two or more. Specifically, 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-ethoxybenzophenone, 2-hydroxy-4-
2-Hydroxybenzophenones such as octoxybenzophenone and 5,5′-methylenebis (2-hydroxy-4-methoxybenzophenone); 2- (2′-hydroxy-5′-methylphenyl) benzotriazole, 2
-(2'-hydroxy-3 ', 5'-di-tert-butylphenyl) -5-chlorobenzotriazole, 2-
(2'-hydroxy-3'-tert-butyl-5'-
Methylphenyl) -5-chlorobenzotriazole, 2
-(2'-hydroxy-5'-tert-octylphenyl) benzotriazole, 2- (2'-hydroxy-
3 ', 5'-dicumylphenyl) benzotriazole,
2,2'-methylenebis (4-tert-octyl-6)
2- (2′-hydroxyphenyl) benzotriazoles such as -benzotriazole) phenol; phenylsalicylate, resorcinol monobenzoate, 2,4
-Di-tert-butylphenyl-3 ', 5'-di-t
Benzoates such as ert-butyl-4′-hydroxybenzoate and hexadecyl-3,5-di-tert-butyl-4-hydroxybenzoate; 2-ethoxy-
Oxanilides such as 4′-dodecyloxanilide; cyanoacrylates such as ethyl-α-cyano-β, β-diphenyl acrylate and methyl-2-cyano-3-methyl-3- (p-methoxyphenyl) acrylate Can be mentioned. These ultraviolet absorbers may be used alone or in combination of two or more. The amount added may be about 0.05 to 5 parts by weight.

Further, if necessary, additives such as a plasticizer, a pigment, an antioxidant, a lubricant, an antistatic agent, an organic filler, an antifogging agent and a light stabilizer may be added.

As the method for molding the biodegradable resin fill of the present invention, a calendering method, an extrusion method, an inflation method or the like which is used in ordinary film molding can be applied. The thickness of the biodegradable resin film of the present invention is preferably about 0.01 to 0.5 mm. 0.01
If it is less than mm, sufficient strength cannot be obtained and 0.5 mm
When it exceeds, the biodegradability becomes slow and the weight becomes heavy, which is not preferable.

As described above, the biodegradable resin film of the present invention is excellent in tear strength, has a low possibility of tearing even when the film is pulled at the time of stretching, and has excellent workability. is there. Further, since the films are excellent in heat resistance and slip property, there is little possibility that the films will be attached to each other in a state of being wound on a roll or during lamination, and therefore, it is difficult to be disentangled and workable and is not easily collapsed during lamination. By adding an ultraviolet absorber as needed, it is possible to use it for a long period of time when it is used in a place other than underground even though it has biodegradability.

[0024]

EXAMPLES Hereinafter, specific examples of the present invention will be described, but the scope of the present invention is not limited to these examples.

[0025]

[Table 1]

[0026]

[Table 2]

Table 1 and terms used in Table 1 and methods for measuring physical properties are as follows. PBS: Polybutylene succinate (Biore # 100
1: Showa High Polymer Co., Ltd.) PBSA: Polybutylene succinate adipate (Bionere # 3001: Showa High Polymer Co., Ltd.) PLA: Polylactic acid (Lacea: Mitsui Chemicals, Inc.) PEC: Polybutylene succinate carbonate (UPEC: Mitsubishi Gas) Chemical Co., Ltd. PCL: Polycaprolactone (Cellgreen PH7: Daicel Chemical Co., Ltd.) PBAT: Polybutylene adipate terephthalate (Ecoflex: BASF Co., Ltd.) Tensile Fracture Elongation (%): Measurement Method According to JIS K 7127 Elemendorff Tear Strength (N / cm): JIS K 7
Measurement method according to 128-2 Dynamic friction coefficient: Measurement according to JIS K 7125, between films of the same type.

A biodegradable resin composition was prepared according to the formulations shown in Tables 1 and 2, and a film having a thickness of 0.1 mm was prepared by an inflation molding machine using the resin composition. The resulting film was measured for tensile breaking elongation, Elemendorf tear strength and dynamic friction coefficient, and the measurement results shown in Table 1 were obtained. As a result, unless an inorganic filler or fatty acid amide is added, the dynamic friction coefficient is inferior to that of the present invention, and if the addition amount is large, problems with physical properties and slipperiness occur.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) // C08L 101/16 C08L 101/16 F term (reference) 4F071 AA45 AB01 AC12 AF15Y AF16Y AF22Y AH01 BB04 BB06 BB09 BC01 4J002 CF051 CF071 DE076 DE106 DE136 DE146 DE236 DE286 DJ016 DJ046 DJ056 EP017 EP027 FD050 GA01 4J200 AA06 AA19 BA09 BA19 CA01 DA01 EA04 EA05

Claims (3)

[Claims] 1. A biodegradable resin containing 0.1 to 1 inorganic filler.
0 parts by weight, 0.01 to 1 parts by weight of fatty acid amide fat are added, the tensile elongation at break is 400 to 1200%, the Elemendorf tear strength is 200 N / cm or more, and the dynamic friction coefficient between biodegradable resin films is A biodegradable resin film, characterized in that it is 0.1 to 0.7. 2. The biodegradable resin film according to claim 1, wherein the main component of the biodegradable resin is a copolymer resin of at least 1,4-butanediol and terephthalic acid. 3. A biodegradable resin, which comprises as a main component,
The biodegradable resin film according to claim 2, wherein other biodegradable resin is added in addition to at least the copolymer resin of 1,4-butanediol and terephthalic acid.