JP2003073531A - Biodegradable binding material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a biodegradable binding material having excellent shape retaining properties and binding force and moderate flexibility. SOLUTION: This biodegradable binding material comprises 100 pts.wt. of an aliphatic polyester, 5-300 pts.wt. of a filler and 1-100 pts.wt. of a plasticizer.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a biodegradable binding material. Specifically, it is plastically deformable, has appropriate flexibility, excellent shape retention, and binding power, and can be used as a binding material for the opening part of food packaging bags such as bread and confectionery, and struts such as vines and stems of cultivated plants. The present invention relates to a biodegradable binding material used for binding materials for vegetables, binding materials for vegetables, binding materials for linear objects such as electric wires, and the like.

[0002]

2. Description of the Related Art Conventionally, as a binding material, a wire core is used as a core material, and a vinyl tie or plastic tie obtained by coating a thermoplastic resin such as polyvinyl chloride, polyethylene, or polyethylene terephthalate, or paper. Products called paper ties are used. However, when binding the mouth of the packaging bag filled with food with the binding material having the wire as the core material, the wire is detected by the metal detector, which makes it difficult to detect the metallic foreign matter. . Recently, as a binding material that does not require a metal detector, a binding material that uses a flexible monofilament of a thermoplastic resin typified by polyethylene terephthalate as a core material instead of wire, and biodegrading both the core material and the covering material. A biodegradable binding material formed of a hydrophilic resin has been proposed.

For example, in Japanese Unexamined Patent Publication No. 10-264961, a core material containing 50 to 300 parts by weight of a filler per 100 parts by weight of a biodegradable aliphatic polyester resin is described as a biodegradable aliphatic polyester. A biodegradable binding string coated with a tape member containing a resin as a main material is disclosed. And, in the examples which are considered to show the preferred embodiments of the invention, both parts of the core material and the covering material are biodegradable resin (Bioshow, manufactured by Showa High Polymer Co., Ltd., trade name, 1,4-butane). A biodegradable tie string formed from a polymer of diol and adipic acid is described. Since bionole is a resin having good flexibility, it is considered that a binding cord having high flexibility can be obtained without adding a plasticizer. The invention describes that a plasticizer may be added in order to impart flexibility. However, no reference is made to a suitable plasticizer and its addition amount.

[0004]

The problems to be solved by the present invention are as follows.
In view of the above problems, it is an object of the present invention to provide a biodegradable binding material that has good suitability for a metal detector, and has excellent shape-retaining property, binding force, and appropriate flexibility.

[0005]

Means for Solving the Problems As a result of intensive studies by the present inventors, a binding material obtained by adding a specific amount of a filler and a plasticizer to an aliphatic polyester can solve the above problems. Therefore, the present invention has been completed.

That is, according to the present invention, 100 parts by weight of the aliphatic polyester, 5 to 300 parts by weight of the filler, and 1 of the plasticizer are used.
It is a biodegradable binding material containing -100 parts by weight.

In the present invention, the aliphatic polyester is preferably a lactic acid type polymer. Further, as the filler, inorganic powder or organic powder is used, and preferred inorganic powders are calcium carbonate, barium sulfate, silica,
Titanium dioxide, or a mixture thereof, and a preferable organic powder is corn starch.

Preferred plasticizers include citric acid esters, phthalic acid esters, adipic acid esters, sebacic acid esters, azelaic acid esters, glycerin esters, or mixtures thereof. Of these, glycerin ester is more preferable. As the glycerin ester, a compound represented by the general formula (1)

[0009]

[Chemical 2]

(Wherein n is an integer of 1 to 9 and R _{1 to} R ₄ are each independently an acyl group having 1 to 18 carbon atoms).

The biodegradable binding material according to the present invention is preferably stretched at least uniaxially by 1.5 to 7 times in consideration of imparting excellent shape retention, binding force, strength and the like. . As a main characteristic, it is preferable that the twist return angle of 360 degrees is 150 degrees or less.

The characteristics of the biodegradable binding material according to the present invention are as follows.
It has appropriate flexibility because it contains a specific amount of plasticizer,
Moreover, it has excellent shape-retaining characteristics and binding force. Therefore, for example, even when a resin having poor flexibility such as a lactic acid-based polymer is used as the aliphatic polyester, a binding material having appropriate flexibility, excellent shape retention and binding force can be obtained. Needless to say, since it is biodegradable, it can be easily disposed of after use. Therefore, a binding material for the opening of a food packaging bag such as bread and confectionery, a binding material for supporting posts such as vines and stems of cultivated plants, a binding material for vegetables,
It is extremely useful as a biodegradable binding material such as a binding material for linear objects such as electric wires. The 360 degree twist return angle in the present invention means a value measured by the method described in Examples described later.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below. The biodegradable binding material according to the present invention is used for extrusion molding, injection molding, etc. of a resin composition containing 5 to 300 parts by weight of a filler and 1 to 100 parts by weight of a plasticizer with respect to 100 parts by weight of an aliphatic polyester. It is manufactured by forming into a rod shape or a string shape by a known forming method. First,
The aliphatic polyester composition used in the present invention will be described.

The aliphatic polyester used in the present invention is an aliphatic polyester containing a lactic acid unit in the molecule. Specifically, (1) polylactic acid and a copolymer of lactic acid and another aliphatic hydroxycarboxylic acid, (2) an aliphatic polyester containing a polyfunctional polysaccharide unit and a lactic acid unit, (3) an aliphatic polycarboxylic acid. An aliphatic polyester containing an acid unit, an aliphatic polyhydric alcohol unit, and a lactic acid unit, and (4) a mixture thereof. Of these, polylactic acid and copolymers of lactic acid and other aliphatic hydroxycarboxylic acids are preferable in view of transparency, hydrolyzability and the like of the biodegradable binding material obtained.

L-lactic acid has an L-form and a D-form, but in the present invention, simply referring to lactic acid means both the L-form and the D-form unless otherwise specified. . The molecular weight of a polymer refers to the weight average molecular weight unless otherwise specified. Examples of the polylactic acid used in the present invention include poly (L-lactic acid) whose constituent unit is L-lactic acid only, poly (D-lactic acid) only D-lactic acid, and L-lactic acid unit and D-lactic acid unit. Examples include poly (DL-lactic acid), which is present in various proportions. Lactic acid-
Hydroxycarboxylic acids of other aliphatic hydroxycarboxylic acid copolymers include glycolic acid, 3-hydroxybutyric acid, 4-hydroxybutyric acid, 4-hydroxyvaleric acid, 5
Examples include -hydroxyvaleric acid and 6-hydroxycaproic acid.

As the method for producing polylactic acid used in the present invention, a method of directly dehydrating and condensing L-lactic acid, D-lactic acid or DL-lactic acid, and a method of ring-opening polymerization of lactide which is a cyclic dimer of each of these lactic acids. Etc. The ring-opening polymerization may be carried out in the presence of a compound having a hydroxyl group such as higher alcohol and hydroxycarboxylic acid. It may be manufactured by any method. As a method for producing a lactic acid-other aliphatic hydroxycarboxylic acid copolymer, a method of dehydrating and polycondensing each lactic acid and the above hydroxycarboxylic acid, a lactide which is a cyclic dimer of each lactic acid and a cyclic body of the above hydroxycarboxylic acid are prepared. Examples thereof include a method of ring-opening copolymerization. It may be manufactured by any method. The amount of lactic acid units contained in the copolymer is preferably at least 40 mol%.

The polyfunctional polysaccharide used for producing an aliphatic polyester containing a polyfunctional polysaccharide unit and a lactic acid unit includes:
For example, cellulose, cellulose nitrate, methyl cellulose, ethyl cellulose, celluloid, viscose rayon, regenerated cellulose, cellophane, cupra, copper ammonia rayon, cuprophan, bemberg, hemicellrol, starch, acropectin, dextrin, dextran, glycogen, pectin, chitin, Examples include chitosan, gum arabic, guar gum, locust bean gum, acacia gum and the like, and mixtures thereof and derivatives thereof. Of these, cellulose acetate and ethyl cellulose are particularly preferable.

As a method for producing an aliphatic polyester containing a polyfunctional polysaccharide unit and a lactic acid unit, a method of reacting the above polyfunctional polysaccharide with the above polylactic acid, lactic acid-another aliphatic hydroxycarboxylic acid copolymer, or the above polyfunctional Examples thereof include a method of reacting a polysaccharide with each of the above-mentioned lactic acids, cyclic esters and the like. It may be manufactured by any method. The amount of lactic acid units contained in the aliphatic polyester is preferably at least 50 mol%.

Examples of the aliphatic polyvalent carboxylic acid used for producing an aliphatic polyester containing an aliphatic polyvalent carboxylic acid unit, an aliphatic polyhydric alcohol unit and a lactic acid unit include:
Examples thereof include oxalic acid, succinic acid, malonic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, undecanedioic acid, dodecanedioic acid and the like, and anhydrides thereof. These may be a mixture with an acid anhydride.
Examples of the aliphatic polyhydric alcohol include ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, 1,3-butanediol, 1,4-butanediol, 3-methyl-1,5-. Pentanediol, 1,6-
Hexanediol, 1,9-nonanediol, neopentyl glycol, tetramethylene glycol, 1,4-
Cyclohexane dimethanol etc. are mentioned.

As a method for producing an aliphatic polyester containing an aliphatic polyhydric carboxylic acid unit, an aliphatic polyhydric alcohol unit and a lactic acid unit, the above aliphatic polycarboxylic acid and the above aliphatic polyhydric alcohol, and the above polylactic acid, Lactic acid-a method of reacting other aliphatic hydroxycarboxylic acid copolymers,
Examples thereof include a method of reacting the above aliphatic polyvalent carboxylic acid and the above aliphatic polyhydric alcohol with each of the above lactic acids, cyclic esters and the like. It may be manufactured by any method. The amount of lactic acid units contained in the aliphatic polyester is preferably at least 50 mol%.

The molecular weight of the aliphatic polyester affects the processability into a binding material, the strength and degradability of the resulting binding material. When the molecular weight is low, the strength of the obtained binding material decreases,
May break under tension when used. Also, the decomposition rate becomes faster. On the other hand, if the molecular weight is high, the processability is lowered.
Considering this point, the molecular weight of the aliphatic polyester is preferably in the range of about 10,000 to about 1,000,000. A more preferable range is 100,000 to 300,000.

The filler used in the present invention includes an inorganic filler and an organic filler. Examples of the inorganic filler include inorganic powders of oxides, hydroxides, carbonates, sulfates and silicates of metals such as magnesium, calcium, barium, boron, aluminum, silicon, titanium, zirconium and hafnium. Examples of the organic filler include grains such as wheat, onions and rice, starches of potatoes such as potatoes, sweet potatoes and tapioca, and organic powders of polysaccharides such as cellulose, chitin and chitosan. These may be used alone,
Further, two or more kinds may be used in combination. Of these, inorganic powders such as calcium carbonate, magnesium carbonate, barium sulfate, titanium dioxide, magnesium silicate, silica, talc, and kaolin are preferable. Corn starch is preferable as the organic powder. More preferably,
Calcium carbonate, barium sulfate, silica, titanium dioxide, and corn starch. The content of the filler is 5 to 300 parts by weight with respect to 100 parts by weight of the aliphatic polyester. It is more preferably 20 to 200 parts by weight.

The plasticizer used in the present invention is preferably a plasticizer having two or more carboxylic acid ester groups in the molecule. Examples thereof include hydroxy polycarboxylic acid ester, polyhydric alcohol ester, and polycarboxylic acid ester. As the hydroxy polycarboxylic acid ester,
Examples of citric acid esters such as tributyl citrate and acetyl tributyl citrate, and polyhydric alcohol esters include:
Glycerin triacetate, glycerin tripropionate, glycerin ester such as glycerin diacetomonolaurate, diglycerin tetraacetate, diglycerin ester such as diglycerin oleate, triethylene glycol ester, triethylene glycol ester such as triethylene glycol dicaprylate, Tetraglycerin caprylate, tetraglycerin stearate, tetraglycerin oleate, hexaglycerin laurate, hexaglycerin oleate, decaglycerin propionate, decaglycerin laurate, decaglycerin behenate, decaglycerin stearate, decaglycerin oleate, etc. Examples of polyglycerin ester and polycarboxylic acid ester include dioctyl phthalate and dibutyl phthalate. Tal acid esters, dioctyl adipate, adipic acid esters of diisobutyl adipate, dibutyl sebacate, sebacic acid esters such as dioctyl sebacate, dioctyl azelate, azelaic acid esters of dihexyl azelate, and the like.

Among these plasticizers, the biodegradable binding material is excellent in shape-retaining property, flexibility and binding power, and considering desirable performance as the binding material, citric acid ester and phthalic acid ester are preferable. , Adipic acid ester, sebacic acid ester, azelaic acid ester, and glycerin ester. Further, among these, glycerin ester is more preferable in view of compatibility with aliphatic polyester, bleed-out resistance and the like. Of the glycerin esters, the compound (A) represented by the general formula (1) is particularly preferable. The content of the plasticizer is 1 to 100 parts by weight with respect to 100 parts by weight of the aliphatic polyester. It is preferably 10 to 80 parts by weight. By including such an amount of plasticizer, a binding material having appropriate flexibility can be obtained.

Compound (A) represented by the above general formula (1)
Is an acylated polyglycerin obtained by acylating a glycerin condensate. Examples of the glycerin condensate used for producing the compound (A) include glycerin 2
Examples thereof include diglycerin, triglycerin, tetraglycerin, and decaglycerin, which are condensates of 10 molecules. Further, as an acylating agent, acetic anhydride, having 1 to 1 carbon atoms
18 carboxylic acid chlorides and the like.

The value of n in the general formula (1) affects the compatibility with the resin and the flexibility of the obtained film. n
If the value is too large, the compatibility with the resin deteriorates, the elastic modulus of the obtained film increases, and the flexibility decreases. Further, the carbon number of the acyl group affects the flexibility of the obtained film. If the number of carbon atoms in the acyl group is too large, the elastic modulus of the obtained film will be high and the flexibility will be reduced. From such a viewpoint, n in the general formula (1) is preferably an integer of 1 to 9. In addition, R _{1 to} R
₄ is preferably an acyl group having 1 to 18 carbon atoms. R _{1 to} R
₄ may be the same acyl group or different acyl groups. Specific compounds include diglycerin tetraacetate, diglycerin tetraoctaneate,
Examples thereof include triglycerin pentastearate and decaglycerin dodecavehenate.

The aliphatic polyester composition used in the present invention includes, in addition to the aliphatic polyester as the main component, the filler and the plasticizer, an anti-blocking agent within the range not impairing the purpose of the present invention, depending on the application. , Hydrocarbons such as liquid paraffin and polyethylene wax, fatty acids such as stearic acid, osh fatty acids, fatty acid amides, alkylenebis fatty acid amides, fatty acid lower alcohol esters, fatty acid polyhydric alcohol esters, fatty acid polyglycol ester , Lubricants such as fatty alcohols, polyhydric alcohols, polyglycols, metal soaps such as calcium stearate, fatty acid salts, higher alcohol sulfuric acid esters, liquid fatty acid sulfuric acid ester salts, aliphatic amines and aliphatic amides Sulfates, aliphatic alcohol phosphate salts Dibasic fatty acid ester sulfonates, aliphatic amide sulfonates, alkylallyl sulfonates, aliphatic amine salts, quaternary ammonium salts, alkylpyridinium salts, polyoxyethene alkyl ethers, polyoxyethylene Alkylphenol ethers, polyoxyethylene alkyl esters, sorbitan alkyl esters, polyoxyethylene sorbitan alkyl esters, imidazoline derivatives, antistatic agents such as higher alkylamines, glycerin fatty acid esters such as glycerin monostearate, sorbitan monolaurate , Sorbitan monooleate and other sorbitan fatty acid esters, polyglycerin fatty acid esters, propylene glycol fatty acid esters and other anti-fog agents,
Ultraviolet rays such as benzotriazoles such as 2- (2'-hydroxy-5'-methylphenyl) benzotriazole, benzophenones such as 2-hydroxy-4-methoxybenzophenone and salicylic acid derivatives such as p-tert-butylphenyl salicylate. Absorbent, phenol-based such as paramethoxyphenol, phosphite-based such as triphenylphosphite, sulfur-based such as 2-mercaptobenzimidazole, amine-based heat stabilizer such as phenylnaphthylamine, antioxidant, anti-coloring agent, Fillers such as barium sulfate, titanium oxide, kaolin, carbon black, pigments,
Other additives such as halogen-based flame retardants such as decabromodiphenyl ether and antimony trioxide and the like may be added.

Next, an example of the aliphatic polyester composition used in the present invention and a method for producing the same will be described. Add filler and plasticizer to aliphatic polyester,
As a method of mixing, an aliphatic polyester and a filler,
A method in which a plasticizer, and optionally other additives are uniformly mixed using a high-speed stirrer or a low-speed stirrer, and then melt-kneaded using a single-screw or multi-screw extruder having sufficient kneading capacity is adopted. You can Generally, the shape of the resin composition according to the present invention is preferably pellet, rod, powder or the like.

The biodegradable binding material of the present invention is obtained by molding the resin composition obtained as described above into a sheet by a melt extrusion method using an extruder equipped with a T die. The obtained sheet is machine direction (hereinafter referred to as MD direction) or MD
It is uniaxially stretched in a direction orthogonal to the direction (hereinafter referred to as TD direction) or biaxially stretched in the MD direction and the TD direction. The MD stretching is preferably roll stretching, and the TD stretching is preferably tenter stretching. A biodegradable binding material is manufactured from the stretched aliphatic polyester sheet obtained by heat treatment under tension after stretching.

The melt extrusion temperature of the aliphatic polyester composition containing the above various additives is preferably 100 to 280.
C., more preferably in the range of 130 to 250.degree. If the molding temperature is low, molding stability is difficult to obtain, and overload tends to occur. On the contrary, if the molding temperature is high, the aliphatic polyester may be decomposed, resulting in a decrease in molecular weight, a decrease in strength, coloration and the like, which is not preferable.

In consideration of mechanical strength, the biodegradable binding material of the present invention is preferably stretched 1.5 to 7 times in at least one axial direction of MD and TD. It is more preferable to biaxially stretch in the MD direction and the TD direction. If the stretching ratio is less than 1.5 times, it is difficult to proceed with crystallization which brings about mechanical properties and dimensional accuracy with time. On the other hand, if it exceeds 7 times, tearing or the like occurs during stretching, which is not preferable. The stretching temperature is the glass transition temperature (Tg) of the aliphatic polyester used.
The range of (Tg + 50) ° C. is preferable. More preferably, it is in the range of Tg to (Tg + 30) ° C. If the stretching temperature is less than Tg, stretching is difficult, and if it exceeds (Tg + 50) ° C., uniform stretching is difficult, which is not preferable. Also, in order to improve heat resistance and dimensional stability, after stretching (T
Heat treatment is performed at a temperature of g + 10) ° C. or higher and lower than the melting point.

The biodegradable binding material containing an aliphatic polyester as a main component of the present invention is produced in a tape shape, a cut sheet shape, or a pipe shape (seamless tubular shape) by setting process conditions according to the purpose. be able to. The shape of the tape-shaped binding material is about 1 to 10 mm in width and 0.01 in thickness.
The shape of the pipe-shaped binding material is, for example, an inner diameter of about 0.01 to 3 mm and a wall thickness of about 0.01 to 2 mm.

For example, an aliphatic polyester resin composition containing an aliphatic polyester resin, a filler and a plasticizer is
Using an extruder equipped with a die having a slit with a width of 20 mm and a thickness of 3 mm at the tip, a cylinder set temperature of 16
Width 10m by melting and extruding at 0-200 ℃
A plate-like material having a length of m and a thickness of 1 mm and continuous in the length direction (MD direction) is obtained. Then, the obtained plate-like material was stretched 5 times in the MD direction and heat-treated at 130 ° C. for 60 seconds to give a width of 5
A uniaxially stretched tape-shaped binding material having a thickness of 0.5 mm and a thickness of 0.5 mm is obtained.

Similarly, an aliphatic polyester resin,
An aliphatic polyester resin composition containing a filler and a plasticizer is melted and extruded at a cylinder set temperature of 160 to 200 ° C. by using an extruder equipped with a die having a slit having a width of 500 mm and a thickness of 3 mm at the tip. A plate-like material having a width of 450 mm and a thickness of 1 mm and continuous in the length direction (MD direction) is obtained. Then, the obtained plate-like material was stretched 3 times in the MD direction and 4 times in the TD direction, and heat-treated at 130 ° C. for 60 seconds to give a width of 1000 mm and a thickness of 0.2 mm.
A biaxially stretched film of is obtained. By slitting this film, a tape-shaped binding material having a width of 5 mm and a thickness of 0.2 mm can be obtained.

Similarly, an extruder having a die having a circular slit having an outer diameter of 10 mm and a gap of 2 mm at the tip is used to set a cylinder set temperature of 160 to 200.
2. Outer diameter 5 mm, inner diameter 3.
A continuous pipe-shaped material having a thickness of 4 mm and a thickness of 0.8 mm in the MD direction is obtained. After that, the obtained pipe-shaped material is 5 in the MD direction.
By double stretching and heat treatment at 130 ° C. for 60 seconds,
A pipe-shaped binding material having an outer diameter of 3 mm, an inner diameter of 2.4 mm and a wall thickness of 0.3 mm can be obtained.

The biodegradable binding material of the aliphatic polyester of the present invention has functions such as antistatic property, antifogging property, tackiness, gas barrier property, adhesion property and easy adhesion property on the surface, if necessary. Layers can be formed by coating. For example, the antistatic layer can be formed by applying an aqueous coating solution containing an antistatic agent to one or both surfaces of the binding material and drying the coating solution. A known method can be applied to the method of applying the aqueous coating solution. That is, a spray coating method, an air knife method, a reverse coating method, a kiss coating method, a gravure coating method, a Meyer bar method, a roll brushing method and the like can be applied. In addition, an acrylic resin-based pressure-sensitive adhesive, for example, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, etc. as a main component, a copolymer obtained by copolymerizing other vinyl-based monomers, a solvent-based solvent in which the copolymer is uniformly dissolved in an organic solvent, and The water-emulsion type coating liquid dispersed in water in the form of particles can be applied to the film by a known method and dried to impart tackiness.

The aliphatic polyester biodegradable binding material of the present invention may be laminated with other resins and films, if necessary, to provide antistatic property, antifogging property, adhesive property, gas barrier property, A layer having functions such as adhesion and easy adhesion can be formed. At that time, known methods such as extrusion laminating and dry laminating can be used.

The biodegradable binding material according to the present invention is manufactured as described above. The main characteristic is that the twist return angle of 360 degrees is 150 degrees or less.
That is, it means that the shape retention property against twisting is excellent. Further, since it contains a plasticizer, it has appropriate flexibility. Furthermore, since it has biodegradability, it can be easily disposed of after use.

[0039]

EXAMPLES The present invention will be described in more detail below with reference to examples. These examples illustrate one embodiment of the invention and are not intended to limit the invention. The performance of the biodegradable tying material according to the present invention was evaluated by the following two types according to the embodiment.

(1) 360 ° twist return angle (degree) At room temperature, two biodegradable binding materials are bundled and twisted at 360 °, and the state is maintained for 10 seconds. After that, the force is released and left for 10 minutes, and the angle returned is defined as the return angle (degree).

Production Example 1 <Preparation of polylactic acid> 100 parts by weight of L-lactide, 0.01 parts by weight of stannous octoate, and 0.03 parts by weight of lauryl alcohol were made of thick cylindrical stainless steel equipped with a stirrer. It was charged into a polymerization vessel, deaerated under vacuum for 2 hours, and then replaced with nitrogen gas. The mixture was heated at 200 ° C. for 3 hours with stirring under a nitrogen atmosphere. While maintaining the temperature as it was, the inside of the reaction vessel was depressurized to 3 mmHg by gradually degassing with a vacuum pump through an exhaust pipe and a glass receiver. After 1 hour from the start of degassing, the distillation of the monomer and low-molecular-weight volatile matter disappeared, so the inside of the container was replaced with nitrogen, and the polymer was extracted from the lower part of the container into a string and pelletized, and the average diameter was 3 mm and the length was 3 mm. A polylactic acid resin was obtained. The weight average molecular weight Mw of this resin was about 130,000.

Preparation Example 2 <Preparation of diglycerin tetraacetate> 84 g of diglycerin and 415 g of acetic anhydride were placed in a reaction flask,
2.5 g of a strongly acidic ion exchange resin (Dow Chemical Co., trade name: Dowex MSC-1) was added, and the reaction was carried out at 80 to 90 ° C. for 1 hour while stirring. After cooling, the ion exchange resin was filtered off and the acetic acid produced and unreacted acetic anhydride were distilled off under reduced pressure to give diglycerin tetraacetate 16
1.5 g was obtained. This is R ₁ ~ in the general formula (1).
R ₄ is an acyl group having 2 carbon atoms, n is 1, the acid value is 0.2, and the hydroxyl value is 3.1.

Example 1 100 parts by weight of the polylactic acid resin obtained in Production Example 1, 100 parts by weight of calcium carbonate particles having an average particle size of 1.0 μm (ACE-25, manufactured by Dowa Calfine Co., Ltd.), and acetyl quench. 20 parts by weight of tributyl acid (manufactured by Kyowa Hakko Kogyo Co., Ltd.) was mixed by a ribbon blender and then pelletized by an extruder at a cylinder temperature of 170 to 210 ° C. to obtain a polylactic acid resin composition. The pellets were heat-treated in an oven at 50 ° C. for 2 hours for crystallization. Then the width 20 at the tip
Using an extruder equipped with a die having a slit of mm mm × thickness 3 mm, it was melted at a cylinder set temperature of 160 to 200 ° C. to obtain a plate-shaped material having a width of 12 mm × thickness of 1.2 mm and continuous in the length direction. The obtained plate-like material was stretched 5 times in the length direction, heat-treated at 130 ° C. for 60 seconds, and then cooled with air at 30 ° C. to obtain a biodegradable binding material having a width of 5 mm and a thickness of 0.5 mm. Got The evaluation results of the obtained biodegradable binding material are shown in [Table 1].

Example 2 100 parts by weight of the polylactic acid resin obtained in Production Example 1 and silica particles having an average particle size of 1.4 μm (Fuji Silysia Chemical Ltd.)
Manufactured by Syriacia 310) and 100 parts by weight of acetyl citrate tributyl (manufactured by Kyowa Hakko Kogyo Co., Ltd.) are mixed with a ribbon blender and then pelletized by an extruder at a cylinder temperature of 170 to 210 ° C. A composition was obtained. 2 the pellets in an oven at 50 ° C
Crystallization was performed by heat treatment for a period of time. Next, width 20m at the tip
An extruder equipped with a die having a slit of m × thickness 3 mm melted at a cylinder set temperature of 160 to 200 ° C. to obtain a plate-shaped material having a width of 15 mm × thickness of 1.5 mm and continuous in the length direction. The obtained plate-like material was stretched 7 times in the length direction, heat-treated at 130 ° C. for 60 seconds, cooled with air at 30 ° C., and biodegradable binding material having a width of 5 mm and a thickness of 0.5 mm. Got The evaluation results of the obtained biodegradable binding material are shown in [Table 1].

Example 3 100 parts by weight of the polylactic acid resin obtained in Production Example 1 and barium sulfate particles having an average particle size of 1.0 μm (Barite Industry Co., Ltd.)
30 parts by weight of precipitated barium sulfate, HD) and tributyl acetyl citrate (Kyowa Hakko Kogyo Co., Ltd.) 5
After mixing 0 parts by weight with a ribbon blender, pelletizing was performed with an extruder at a cylinder temperature of 170 to 210 ° C. to obtain a polylactic acid resin composition. The pellets were heat-treated in an oven at 50 ° C. for 2 hours for crystallization. Then, with an extruder equipped with a die having a slit with a width of 20 mm and a thickness of 3 mm, the cylinder set temperature is 160 to 200 ° C.
To obtain a plate-shaped material having a width of 10 mm and a thickness of 1.0 mm and continuous in the length direction. The obtained plate-like material was stretched 4 times in the length direction and heat-treated at 130 ° C for 60 seconds, and then at 30 ° C.
The sample was cooled using the above air to obtain a biodegradable binding material having a width of 5 mm and a thickness of 0.5 mm. The evaluation results of the obtained biodegradable binding material are shown in [Table 1].

Example 4 100 parts by weight of the polylactic acid resin obtained in Production Example 1 and titanium dioxide particles having an average particle size of 0.21 μm (Ishihara Sangyo Co., Ltd.)
Manufactured by Taipaque CR-60), 180 parts by weight, and glycerin diacetomonolaurate (RIKEN VITAMIN Co., Ltd.)
20 parts by weight of Riquemar PL-012), manufactured by Ricamar Co., Ltd., were mixed in a ribbon blender and then pelletized by an extruder at a cylinder temperature of 170 to 210 ° C. to obtain a polylactic acid resin composition. The pellets were heat-treated in an oven at 50 ° C. for 2 hours for crystallization. Then, with an extruder equipped with a die having a slit with a width of 20 mm and a thickness of 3 mm at the tip, it is melted at a cylinder setting temperature of 160 to 200 ° C., and a plate-shaped material having a width of 15 mm and a thickness of 1.5 mm and continuous in the length direction is obtained. Obtained. The obtained plate-like material was stretched 7 times in the longitudinal direction,
After heat treatment at 0 ° C. for 60 seconds, it was cooled using air at 30 ° C. to obtain a biodegradable binding material having a width of 5 mm and a thickness of 0.5 mm. The evaluation results of the obtained biodegradable binding material are shown in [Table 1].
Shown in.

Example 5 100 parts by weight of the polylactic acid resin obtained in Production Example 1, 180 parts by weight of corn starch (manufactured by Japan Corn Starch Co., Ltd., White Cons), and glycerin diacetomonolaurate (manufactured by Riken Vitamin Co., Ltd., Product name: Rikemar P
After mixing 5 parts by weight of L-012) with a ribbon blender, the mixture was pelletized with an extruder at a cylinder temperature of 170 to 210 ° C. to obtain a polylactic acid resin composition. 5 of the pellets
Crystallization was performed by heat treatment for 2 hours in an oven at 0 ° C. Then, using an extruder equipped with a die having a slit with a width of 20 mm and a thickness of 3 mm at the tip, a cylinder set temperature of 16
It was melted at 0 to 200 ° C. to obtain a plate-like material having a width of 12 mm and a thickness of 1.2 mm and continuous in the length direction. The obtained plate-like material was stretched 5 times in the length direction, heat-treated at 130 ° C. for 60 seconds, and then cooled with air at 30 ° C. to obtain a biodegradable binding material having a width of 5 mm and a thickness of 0.5 mm. Got The evaluation results of the obtained biodegradable binding material are shown in [Table 1].

Example 6 100 parts by weight of the polylactic acid resin obtained in Production Example 1, 100 parts by weight of calcium carbonate particles having an average particle size of 1.0 μm (ACE-25, manufactured by Dowa Calfine Co., Ltd.), and glycerindia Setomonolaurate (manufactured by Riken Vitamin Co., Ltd.,
Product name: LIKEMAR PL-012) 100 parts by weight were mixed by a ribbon blender and then pelletized by an extruder at a cylinder temperature of 170 to 210 ° C. to obtain a polylactic acid resin composition. The pellets were heat-treated in an oven at 50 ° C. for 2 hours for crystallization. Then, with an extruder equipped with a die having a slit having a width of 20 mm and a thickness of 3 mm, a plate-shaped material having a width of 12 mm and a thickness of 1.2 mm and continuous in a length direction is melted at a cylinder set temperature of 160 to 200 ° C. Obtained. The obtained plate-like material was stretched 5 times in the longitudinal direction,
After heat treatment at 0 ° C. for 60 seconds, it was cooled using air at 30 ° C. to obtain a biodegradable binding material having a width of 5 mm and a thickness of 0.5 mm. The evaluation results of the obtained biodegradable binding material are shown in [Table 1].
Shown in.

Example 7 100 parts by weight of the polylactic acid resin obtained in Production Example 1, 5 parts by weight of calcium carbonate particles having an average particle size of 1.0 μm (ACE-25, manufactured by Dowa Calfine Co., Ltd.), and Preparation Example 3 parts by weight of diglycerin tetraacetate obtained in 2 was mixed with a ribbon blender and then pelletized by an extruder at a cylinder temperature of 170 to 210 ° C. to obtain a polylactic acid resin composition. The pellets were heat-treated in an oven at 50 ° C. for 2 hours for crystallization. Then, with an extruder equipped with a die having a slit having a width of 20 mm and a thickness of 3 mm, a plate-shaped material having a width of 12 mm and a thickness of 1.2 mm and continuous in a length direction is melted at a cylinder set temperature of 160 to 200 ° C. Obtained. The obtained plate-like material was stretched 5 times in the longitudinal direction,
After heat treatment at 0 ° C. for 60 seconds, it was cooled using air at 30 ° C. to obtain a biodegradable binding material having a width of 5 mm and a thickness of 0.5 mm. The evaluation results of the obtained biodegradable binding material are shown in [Table 2].
Shown in.

Example 8 100 parts by weight of the polylactic acid resin obtained in Production Example 1 and barium sulfate particles having an average particle size of 1.0 μm (Barite Industry Co., Ltd.)
50 parts by weight of diglycerin tetraacetate obtained in Preparation Example 2 was mixed with a ribbon blender, and then pelletized at a cylinder set temperature of 170 to 210 ° C. by an extruder, A lactic acid resin composition was obtained. The pellets were heat-treated in an oven at 50 ° C. for 2 hours for crystallization. Then the width 20 at the tip
Using an extruder equipped with a die having a slit of mm mm × thickness 3 mm, it was melted at a cylinder set temperature of 160 to 200 ° C. to obtain a plate-shaped material having a width of 10 mm × a thickness of 1.0 mm and continuous in the length direction. The obtained plate-like material was stretched 4 times in the length direction, heat-treated at 130 ° C. for 60 seconds, cooled with air at 30 ° C., and biodegradable binding material having a width of 5 mm and a thickness of 0.5 mm. Got The evaluation results of the obtained biodegradable binding material are shown in [Table 2].

Example 9 100 parts by weight of the polylactic acid resin obtained in Production Example 1 and silica particles having an average particle size of 1.4 μm (Fuji Silysia Chemical Ltd.)
Manufactured by Sylysia 310) 100 parts by weight, and Preparation Example 2
100 parts by weight of the diglycerin tetraacetate obtained in 1. was mixed with a ribbon blender, and then pelletized by an extruder at a cylinder temperature of 170 to 210 ° C. to obtain a polylactic acid resin composition. The pellets were heat-treated in an oven at 50 ° C. for 2 hours for crystallization. Next, width 20mm at the tip
With an extruder equipped with a die having a slit with a thickness of 3 mm, it is melted at a cylinder set temperature of 160 to 200 ° C.,
A plate-like material having a width of 10 mm and a thickness of 1.0 mm and continuous in the length direction was obtained. The obtained plate-like material is stretched 4 times in the length direction, and 1
After heat treatment at 30 ° C. for 60 seconds, it was cooled with air at 30 ° C. to obtain a biodegradable binding material having a width of 5 mm and a thickness of 0.5 mm. The evaluation results of the obtained biodegradable binding material are shown in [Table 2].

Example 10 100 parts by weight of the polylactic acid resin obtained in Production Example 1, 300 parts by weight of corn starch (manufactured by Japan Corn Starch Co., Ltd., White Cons), and 100 parts by weight of diglycerin tetraacetate obtained in Preparation Example 2. After mixing parts with a ribbon blender, set the cylinder temperature to 170-2 by the extruder.
Pelletization was performed at 10 ° C to obtain a polylactic acid resin composition. The pellets were heat-treated in an oven at 50 ° C. for 2 hours for crystallization. Then, with an extruder equipped with a die having a slit with a width of 20 mm and a thickness of 3 mm at the tip, it is melted at a cylinder set temperature of 160 to 200 ° C., and a plate-like material having a width of 10 mm and a thickness of 1.0 mm and continuous in the length direction is obtained. Obtained. The obtained plate-like material was stretched 4 times in the length direction, heat-treated at 130 ° C. for 60 seconds, and then cooled with air at 30 ° C. to give a width of 5
A biodegradable binding material having a size of mm × 0.5 mm was obtained. The evaluation results of the obtained biodegradable binding material are shown in [Table 2].

Example 11 100 parts by weight of the polylactic acid resin obtained in Production Example 1, 50 parts by weight of calcium carbonate particles having an average particle size of 1.0 μm (ACE-25, manufactured by Dowa Calfine Co., Ltd.), and Preparation Example Two
30 parts by weight of the diglycerin tetraacetate obtained in 1 above was mixed with a ribbon blender and then pelletized by an extruder at a cylinder temperature of 170 to 210 ° C. to obtain a polylactic acid resin composition. The pellets were heat-treated in an oven at 50 ° C. for 2 hours for crystallization. Next, width 20mm at the tip
With an extruder equipped with a die having a slit with a thickness of 3 mm, it is melted at a cylinder set temperature of 160 to 200 ° C.,
A biodegradable binding material having a width of 5 mm and a thickness of 0.5 mm was obtained. The evaluation results of the obtained biodegradable binding material are shown in [Table 2].

Example 12 100 parts by weight of the polylactic acid resin obtained in Production Example 1, 30 parts by weight of calcium carbonate particles having an average particle size of 1.0 μm (ACE-25, manufactured by Dowa Calfine Co., Ltd.), and Preparation Example Two
50 parts by weight of the diglycerin tetraacetate obtained in 1. was mixed with a ribbon blender and then pelletized by an extruder at a cylinder temperature of 170 to 210 ° C. to obtain a polylactic acid resin composition. The pellets were heat-treated in an oven at 50 ° C. for 2 hours for crystallization. Then, the width is 500 mm at the tip
× 450 mm in width × 1.0 m in thickness by melting and extruding at a cylinder set temperature of 160 to 200 ° C. using an extruder equipped with a die having a slit of 3 mm in thickness
A plate-like material continuous in the length direction of m was obtained. The obtained plate-like material was stretched 3 times in the length direction and 4 times in the width direction, and was drawn at 130 ° C. for 6 times.
A film having a width of 1000 mm and a thickness of 0.2 mm was obtained by heat treatment for 0 seconds. By slitting this film, a tape-like biodegradable binding material having a width of 5 mm and a thickness of 0.2 mm was obtained. The evaluation results of the obtained biodegradable binding material are shown in [Table 2].

Comparative Example 1 100 parts by weight of the polylactic acid resin obtained in Production Example 1 was pelletized by an extruder at a cylinder set temperature of 170 to 210 ° C. The pellets were heat-treated in an oven at 50 ° C. for 2 hours for crystallization. Then, using an extruder equipped with a die having a slit with a width of 20 mm and a thickness of 3 mm at the tip, it was melted at a cylinder set temperature of 160 to 200 ° C. to obtain a biodegradable binding material having a width of 5 mm and a thickness of 0.5 mm. The evaluation results of the obtained biodegradable binding material are shown in [Table 3].

Comparative Example 2 100 parts by weight of the polylactic acid resin obtained in Production Example 1 and tributyl acetyl citrate (Kyowa Hakko Kogyo Co., Ltd.)
After mixing 20 parts by weight with a ribbon blender, pelletizing with an extruder at a cylinder set temperature of 170 to 210 ° C.,
A polylactic acid resin composition was obtained. The pellets were heat-treated in an oven at 50 ° C. for 2 hours for crystallization. Then, using an extruder equipped with a die having a slit having a width of 20 mm and a thickness of 3 mm at the tip, the cylinder set temperature is 160 to 200.
It was melted at 0 ° C. to obtain a plate-like material having a width of 12 mm and a thickness of 1.2 mm and continuous in the length direction. The obtained plate-like object is lengthwise 5
Double stretching and heat treatment at 130 ° C. for 60 seconds, then 30
It was cooled using air at 0 ° C. to obtain a biodegradable binding material having a width of 5 mm and a thickness of 0.5 mm. The evaluation results of the obtained biodegradable binding material are shown in [Table 3].

Comparative Example 3 100 parts by weight of the polylactic acid resin obtained in Production Example 1 and 30 parts by weight of calcium carbonate particles having an average particle size of 1.0 μm (ACE-25, manufactured by Dowa Calfine Co., Ltd.) were used in a ribbon blender. Cylinder set temperature 1 by extruder after mixing in
Pelletization was performed at 70 to 210 ° C to obtain a polylactic acid resin composition. The pellets were heat-treated in an oven at 50 ° C. for 2 hours for crystallization. Next, width 20mm x thickness 3m at the tip
With an extruder equipped with a die having a slit of m, it melts at a cylinder set temperature of 160 to 200 ° C. and has a width of 12 m.
A plate-like material having a continuous length of m × 1.2 mm was obtained. The obtained plate-like material is stretched 5 times in the length direction, and the temperature is 130 ° C.
After heat treatment for 60 seconds at 30 ° C., it was cooled using air at 30 ° C. to obtain a biodegradable binding material having a width of 5 mm and a thickness of 0.5 mm. The evaluation results of the obtained biodegradable binding material are shown in [Table 3].

Comparative Example 4 100 parts by weight of the polylactic acid resin obtained in Production Example 1, 400 parts by weight of calcium carbonate particles having an average particle size of 1.0 μm (ACE-25, manufactured by Dowa Calfine Co., Ltd.), and acetyl. Tributyl citrate (Kyowa Hakko Kogyo Co., Ltd.)
After mixing 30 parts by weight with a ribbon blender, pelletizing with an extruder at a cylinder set temperature of 170 to 210 ° C.,
A polylactic acid resin composition was obtained. The pellets were heat-treated in an oven at 50 ° C. for 2 hours for crystallization. Then, using an extruder equipped with a die having a slit having a width of 20 mm and a thickness of 3 mm at the tip, the cylinder set temperature is 160 to 200.
It was melted at 0 ° C. to obtain a plate-like material having a width of 12 mm and a thickness of 1.2 mm and continuous in the length direction. The obtained plate-like object is lengthwise 5
An attempt was made to double stretch, but stretch breakage occurred and stretching was impossible.

Comparative Example 5 100 parts by weight of the polylactic acid resin obtained in Production Example 1 and barium sulfate particles having an average particle size of 1.0 μm (Barite Industry Co., Ltd.)
100 parts by weight of precipitated barium sulfate, HD) and glycerin diacetomonolaurate (manufactured by Riken Vitamin Co., Ltd., trade name: RIKEMAR PL-012) are mixed with a ribbon blender, and then the cylinder temperature is set to 170 to 170 by an extruder. Pelletization was carried out at 210 ° C. to obtain an aliphatic polyester composition. The pellets were heat-treated in an oven at 50 ° C. for 2 hours for crystallization. Next, width 20mm at the tip
With an extruder equipped with a die having a slit with a thickness of 3 mm, it is melted at a cylinder set temperature of 160 to 200 ° C.,
A plate-like material having a width of 12 mm and a thickness of 1.2 mm and continuous in the length direction was obtained. The obtained plate-like material is stretched 5 times in the length direction, and 1
After heat treatment at 30 ° C. for 60 seconds, it was cooled with air at 30 ° C. to obtain a biodegradable binding material having a width of 5 mm and a thickness of 0.5 mm. The evaluation results of the obtained biodegradable binding material are shown in [Table 3].

[0060]

[Table 1]

[0061]

[Table 2]

[0062]

[Table 3]

[0063]

The biodegradable binding material according to the present invention contains a specific amount of filler and plasticizer, and has excellent shape-retaining property, binding force, and appropriate flexibility. It goes without saying that disposal after use is easy. Therefore, the tying material for the opening parts of food packaging bags for bread, confectionery, vines for cultivated plants, etc.
It is extremely useful as a biodegradable binding material such as a binding material for a pillar such as a stem, a binding material for vegetables, a binding material for linear objects such as electric wires, and the like.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) C08J 5/18 CFD C08J 5/18 CFD C08K 3/22 C08K 3/22 3/26 3/26 3/30 3/30 3/36 3/36 5/103 5/103 5/11 5/11 5/12 5/12 // B65D 65/46 B65D 65/46 B29K 67:00 B29K 67:00 105: 16 105: 16 B29L 31:00 B29L 31:00 (72) Inventor Yasuhiro Kitahara 580-32 Mitsui Chemicals Co., Ltd. Nagaura, Sodegaura City, Chiba Prefecture In-house (72) Inventor Akinori Takehara 580-32 Nagaura, Sodegaura City, Chiba Mitsui Chemicals Formula In-company (72) Inventor Shoji Obuchi 580-32 Nagaura, Sodegaura-shi, Chiba Mitsui Chemicals Co., Ltd. F-term in the company (reference) 3E085 BA25 BB06 BC09 BD08 BE06 BE10 BG03 BG04 BG05 BG10 3E086 AA21 AB10 AD30 BA02 BA15 BA33 BA35 BB90 CA40 DA08 4F071 AA08 AA09 AA43 AA44 AB18 AB21 AB24 AB26 AC 10 AD02 AE04 AE17 AF52 AF53 AH04 AH05 BA01 BB06 BB07 BC01 BC17 4F210 AA01 AA24 AB07A AB11 QC02 QG01 QG18 QW07 4J002 AB012 AB042 AB052 CF031 CF181FD FD 01797 FD 017E0F0E027E027H0E027E0H0E0H0A0A0A0A024 GG02

Claims (9)

[Claims] 1. A biodegradable binding material containing 100 parts by weight of an aliphatic polyester, 5 to 300 parts by weight of a filler, and 1 to 100 parts by weight of a plasticizer. 2. The biodegradable binding material according to claim 1, wherein the aliphatic polyester is a lactic acid-based polymer. 3. The biodegradable binding material according to claim 1, wherein the filler is an inorganic powder or an organic powder. 4. The biodegradation according to claim 3, wherein the inorganic powder is at least one powder selected from calcium carbonate, barium sulfate, silica, and titanium dioxide, and the organic powder is corn starch. Sex binding material. 5. The plasticizer is citric acid ester, phthalic acid ester, adipic acid ester, sebacic acid ester,
2. At least one ester compound selected from azelaic acid ester and glycerin ester.
The biodegradable binding material described. 6. The biodegradable binding material according to claim 1, wherein the plasticizer is glycerin ester. 7. The glycerin ester has the general formula (1):
[Chemical 1] [Chemical 1] The biodegradable binding material according to claim 6, which is a compound represented by the formula (n is an integer of 1 to 9 and R _{1 to} R ₄ are each independently an acyl group having 1 to 18 carbon atoms). 8. The biodegradable raw binding material according to claim 1, which is stretched at least uniaxially by 1.5 to 7 times. 9. The biodegradable binding material according to claim 1, wherein the twist return angle of 360 degrees is 150 degrees or less.