JP2003081323A - Biodegradable rope for automatic binding machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rope for an automatic binding machine having a mechanical adaptability for the automatic binding machine and having a biodegradable property. SOLUTION: There is provided a biodegradable rope for an automatic binding machine in which a uniaxial extension film coated with silicone oil at its surface, containing polylactic acid and an aliphatic polyester other than polylactic acid and a containing ratio of polylactic acid and the aliphatic polyester other than polylactic acid is 5:95 to 30:70 by a weight ratio is taken up in a fine size and annealed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cord having mechanical suitability and biodegradability as a cord for an automatic binding machine.

[0002]

2. Description of the Related Art Conventionally, there are two types of binding straps, one for hand binding and one for automatic binding machines, and both are generally manufactured by similar manufacturing methods. The raw material is polypropylene (PP),
High density polyethylene (HDPE) is used, but HDPE is commonly used for automatic binding machines. In a general manufacturing process of a binding string, first, raw resin is mixed and melted by an extruder, and then the molten resin is extruded from a die and cooled to form a raw film. While this raw film is being heated, it is stretched in a uniaxial direction by a stretching machine and wound. As a stretching method, there are an in-line method in which a stretching step is continuously performed after film formation and an offline method in which an unstretched film that has been once wound is rewound and stretched.
In the early days, an off-line method was adopted as a measure against stretch breakage in a stretching machine, but embrittlement due to film cooling,
There is a problem in the slit portion due to film distortion due to aging, and currently the in-line method is generally adopted. Bundling strength and elongation properties are also required for hand tying strings, but automatic binding machine strings are
Additional mechanical suitability for automatic binding machines is also required. Examples of the additional mechanical suitability include tensile impact strength when binding a bundle, unwinding property when unwinding a string, binding suitability when making a knot, and the like. Polyolefin resins such as PP and HDPE generally have good mechanical suitability required for a cord for an automatic binding machine.

Recently, however, the market demand for "environmentally friendly" has been increasing, and pollution and environmental damage caused by incineration and landfill of used polyolefin products have become problems. Therefore, even if the mechanical suitability for an automatic binding machine is satisfied, it is not possible to rely on a polyolefin resin such as PP or HDPE, and a prompt response is required. Considering the problems of pollution generation and environmental damage, market needs will be met if an automatic binding machine string having biodegradability and satisfying mechanical suitability for an automatic binding machine is obtained.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to provide a cord for an automatic binding machine which has mechanical suitability for an automatic binding machine and is biodegradable.

[0005]

Means for Solving the Problems The inventors of the present invention have conducted extensive studies to solve the above problems, and as a result, contain polylactic acid and an aliphatic polyester other than polylactic acid coated with silicone oil on the surface. The content ratio of polylactic acid and aliphatic polyester other than polylactic acid is 5:95 to 3 by weight ratio.
A biodegradable string for an automatic binding machine, which is obtained by thinly winding and annealing a 0:70 uniaxially stretched film, has the mechanical suitability for the automatic binding machine, and has the biodegradability. The present invention has been completed by finding that it can be used as a cord.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION The biodegradable cord for an automatic binding machine according to the present invention will be described in detail below.

The polylactic acid is not particularly limited, but includes Lacty (trade name) of Shimadzu Corporation, Lasia (trade name) of Mitsui Chemicals, Ecoplay (trade name) and Nature Works (trade name) of Cargill Japan. ) And the like.

The aliphatic polyester other than polylactic acid is not particularly limited, but it is polycaprolactone, Daicel Chemical's Cell Green (trade name), polybutylene succinate or polybutylene succinate adipate, Showa High School. Molecular bionore (trade name), polyethylene catalyst succinate Nippon Catalyst Lunare (trade name)
Etc. Among these, polycaprolactone and polybutylene succinate are particularly preferable because they are excellent in both binding strength and tensile impact resistance.

In the biodegradable string for an automatic binding machine of the present invention, the content ratio of polylactic acid and aliphatic polyester other than polylactic acid is preferably within the range of 5:95 to 30:70 by weight. . When the proportion of polylactic acid exceeds 30% by weight, the binding strength is increased but the tensile impact resistance is lowered and the payout property is also deteriorated. On the other hand, when the proportion of polylactic acid is less than 5% by weight, the binding strength is insufficient. The content ratio of polylactic acid and the aliphatic polyester other than polylactic acid is 10:90 to 20:80 by weight.
It is particularly preferable that it is within the range.

In the biodegradable string for an automatic binding machine of the present invention, an inflation method, a T-die method or the like can be applied as an extrusion molding method. The unstretched original film obtained by extrusion molding is slit into a required width to form a single bundle tape. In the biodegradable string for an automatic binding machine of the present invention, as a stretching method, a roll stretching method, a hot plate stretching method, or the like can be applied. Both an in-line method in which the stretching step is continuously performed from the film forming and an offline method in which the unstretched film once wound is rewound and stretched are applicable.

In the biodegradable string for the automatic binding machine of the present invention, the silicone oil to be applied is straight silicone oil (for example, the side chain or terminal organic group is dimethyl, methyl phenyl, methyl hydrogen). )
Or (for example, a side chain or a terminal organic group is alkyl, alkyl / aralkyl, fluorinated alkyl, polyoxyalkylene, amino, epoxy, alcohol, mercapto,
Carboxylic acid), but modified silicone oil is preferable, and nonionic aqueous emulsion of dimethylpolysiloxane is particularly preferable.

In the biodegradable string for an automatic binding machine of the present invention, sufficient binding strength can be obtained by stretching the film in a uniaxial direction at a draw ratio of 2.0 to 5.0. When the stretching ratio is less than 2.0 times, the uniaxial orientation of the molecular chains is weak and sufficient binding strength cannot be obtained. On the other hand, if the draw ratio is more than 5.0 times, breakage of the draw occurs at a considerable frequency, which causes a difficulty in producing a biodegradable string for an automatic binding machine.

The uniaxially stretched film containing polylactic acid and an aliphatic polyester other than polylactic acid according to the present invention may optionally contain stabilizers, lubricants, plasticizers, fillers, colorants and the like.

In the present invention, a single bundle of tape has a width of 1 /
To make a string of 4 or less bundles, for example, squeeze with a finger or pass through a narrow groove.

In the present invention, a single bundle of tape has a width of 1 /
Annealing a double-bundle-shaped cord of 4 or less in a temperature range of 50 ° C. or higher and lower than the melting point removes internal stress, maintains the double-bundle-shaped cord shape, and provides feeding and automatic binding properties. Remarkably improved.

[0016]

EXAMPLES The contents of the present invention will be described more specifically below by showing Examples and Comparative Examples, but the present invention is not limited by the matters described in the Examples below.

Example 1 As materials for a biodegradable string for an automatic binding machine, 15% by weight of polylactic acid (Lacty 9030 manufactured by Shimadzu Corporation) and polybutylene succinate (Bionole # 1 manufactured by Showa High Polymer Co., Ltd.) were used.
001) 85 weight percent was mixed in a tumble mixer and equipped with a die diameter of 50 mm, the diameter was 55 m
After melt-kneading at 190 ° C. using an extruder having m and L / D of 28, an unstretched raw film was obtained by inflation molding. Stretching was performed in an in-line method at a hot plate temperature of 90 ° C. and a stretching ratio of 3.0 times. The width of a single bundle of tape is 35
It was mm. Silicone oil (Matsumoto Yushi-Seiyaku Co., Ltd. Matsumoto Silicone Softener # 100) was applied to this single-bundle tape, and then rewound by hand squeezing to form a double-bundle string. At this time, the width of the twine-shaped string was 5 mm. The rewound string was annealed at 80 ° C. for 3 hours to obtain the biodegradable string for the automatic binding machine of the present invention. The evaluation results are shown in Table 1.

Example 2 30% by weight of polylactic acid (Lacty 9030 manufactured by Shimadzu Corporation) and 70% by weight of polybutylene succinate (Bionole # 1001 manufactured by Showa High Polymer Co., Ltd.) were used to obtain a draw ratio of 4.0 times. A biodegradable string for an automatic tying machine of the present invention was obtained in the same manner as in Example 1 except that the test was carried out. The evaluation results are shown in Table 1.

Example 3 A mixture of 15% by weight of polylactic acid (Lacty 9030 manufactured by Shimadzu Corp.) and 85% by weight of polycaprolactone (Cellgreen PHB02 manufactured by Daicel Chemical Industries) was used at a draw ratio of 3.2 times. A biodegradable string for an automatic binding machine of the present invention was obtained in the same manner as in Example 1 except for the above. The evaluation results are shown in Table 1.

Comparative Example 1 A comparative tape was prepared by using the same composition and method as in Example 1 except that silicone oil (Matsumoto Yushi-Seiya Co., Ltd. Matsumoto Silicone Softener # 100) was not applied to a single bundle of tape. A biodegradable string for an automatic binding machine was obtained. The evaluation results are shown in Table 1.

Comparative Example 2 As Example 1 except that a mixture of 50% by weight of polylactic acid (Lacty 9030 manufactured by Shimadzu Corporation) and 50% by weight of polybutylene succinate (Bionole # 1001 manufactured by Showa High Polymer Co., Ltd.) was used. By the same method, a biodegradable string for an automatic binding machine for comparison was obtained. The evaluation results are shown in Table 1.

Comparative Example 3 A biodegradable string for an automatic binding machine for comparison was obtained with the same composition and method as in Example 1 except that annealing was not performed. The evaluation results are shown in Table 1.

With respect to the biodegradable strings for automatic binding machines of Examples 1 to 3 and Comparative Examples 1 to 3 described above, the mechanical suitability of the automatic binding machine was evaluated by the following method. The automatic binding machine at the time of evaluation is
A Y80 type manufactured by Yamada Machinery Co., Ltd. was used.

Tensile impact resistance: A binding test was conducted in each of the examples and comparative examples, and the presence or absence of breakage at the stage of winding the cord was evaluated. The evaluation criteria are as follows. ○: No disconnection ×: There is disconnection

Feedability: A binding test was conducted in each of the examples and comparative examples, and evaluation was made by the arm return position of the binding machine at the end of binding. The evaluation criteria are as follows. ○: It has completely returned to the original position. Δ: Almost completely returned to the original position. ×: Does not return to the original position.

Automatic tying property: A tying test was carried out in each of the examples and comparative examples to evaluate the finished state of the knot at the end of tying. The evaluation criteria are as follows. ⊚: The knots have a particularly beautiful finish and the cut ends are also particularly beautiful. ○: The knot has a beautiful finish and the cut end is also in a beautiful state. Δ: The knot is made, but the finish is dirty. The cut end is also dirty. X: No knot is formed and no binding is formed.

Comprehensive evaluation: Comprehensive evaluation of mechanical suitability as a cord for an automatic binding machine was carried out from evaluations of tensile impact resistance, feeding property and automatic binding property. The evaluation criteria are as follows. ⊚: Mechanical suitability as a cord for an automatic binding machine is very good. Good: Mechanical suitability as a string for an automatic binding machine is good. Δ: Mechanical suitability as a string for an automatic binding machine is insufficient. X: There is almost no mechanical suitability as a string for an automatic binding machine.

[0028]

[Table 1]

[0029]

The biodegradable cord for an automatic binding machine according to the present invention has excellent mechanical suitability as a cord for an automatic binding machine, and is also environmentally friendly due to its biodegradability.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) // (C08L 67/00 C08L 67:04 67:04) B29K 67:00 B29K 67:00 B29L 7:00 B29L 7:00 (72) Inventor Yukio Iizuka 1744 Mamon-cho, Sano-shi, Tochigi Itochu Sampler Co., Ltd. Sano factory No. 1 (72) Inventor Naoki Hatakeyama 1-3, Sakae-cho, Sano-shi, Tochigi Prefecture ITOCHU Samples Co., Ltd. Internal F-term (reference) 3E052 BA16 LA19 3E085 BA21 BD08 BD10 BE02 BE06 BE10 4F006 AA35 AB39 BA09 BA12 CA07 DA04 4F210 AA24 AG14 QC01 QC02 QD08 QW07 4J002 CF031 CF182 CF191 GG00

Claims (5)

[Claims] 1. A surface-coated silicone oil containing polylactic acid and an aliphatic polyester other than polylactic acid, and the content ratio of polylactic acid to the aliphatic polyester other than polylactic acid is 5:95 to 30 by weight. A biodegradable string for an automatic binding machine, which is obtained by thinly winding and annealing a uniaxially stretched film of: 70. 2. The biodegradable string for an automatic binding machine according to claim 1, wherein the silicone oil is at least one selected from the group consisting of straight silicone oil and modified silicone oil. 3. The biodegradable string for an automatic binding machine according to claim 1, wherein the silicone oil is a nonionic aqueous emulsion of dimethylpolysiloxane. 4. The biodegradable string for an automatic binding machine according to claim 1, wherein the draw ratio is 2.0 to 5.0. 5. The single-bundle tape is formed into a double-bundle string having a width of 1/4 or less, which is wound and then annealed.
A biodegradable string for an automatic binding machine according to any one of items 1 to 4.