JP2662494B2 - Polyester packing band - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention has a biodegradable property,
The present invention relates to a packing band which is made of an aliphatic polyester having a practically sufficient high molecular weight and specific melting properties and which has excellent heat stability and mechanical strength.

[0002]

2. Description of the Related Art In recent years, with the progress of distribution systems, containers, bags, packing materials, and the like used for distribution have been made into plastics. Has become a major social problem. For the prevention of this pollution, the emergence of biodegradable plastics has been anticipated. For example, poly (3) produced by a fermentation method using microorganisms has already been developed. −
A blend of starch (hydroxybutyrate) or a blend-type natural polymer with a general-purpose plastic is known. However, in the former, the thermal decomposition temperature of the polymer is close to the melting point, so the moldability is inferior and microorganisms create it.
The raw material unit has a very bad disadvantage. In the latter, since the natural polymer itself is not thermoplastic, there is a difficulty in moldability, and the use range is greatly restricted. On the other hand, although aliphatic polyesters are known to have biodegradability, they have hardly been used because a high molecular weight product sufficient for obtaining practical molded article properties cannot be obtained. Recently,
It has been found that ε-caprolactone has a high molecular weight by ring-opening polymerization, and it has been proposed as a biodegradable resin. . Glycolic acid and lactic acid also have high molecular weights obtained by ring-opening polymerization of glycolide and lactide, and are slightly used in medical fibers, etc. It has not yet been used in large quantities in application materials.

A high-molecular-weight polyester generally used for molding a packing band as one of the materials for the distribution system (here, the high-molecular-weight polyester refers to a polyester having a number average molecular weight of 10,000 or more). Is limited to polyethylene terephthalate, which is a condensate of terephthalic acid (including dimethyl terephthalate) and ethylene glycol. In some cases, 2,6-naphthalenedicarboxylic acid is used in place of terephthalic acid. However, in any case, attempts to impart biodegradability have not yet been reported. Therefore, it can be said that there is no idea of forming a packaging band using a biodegradable aliphatic polyester using an aliphatic type dicarboxylic acid as a conventional dicarboxylic acid and putting it into practical use. One of the reasons why this idea of practical application has not been born is that even though the packing band is crystalline even though special molding conditions and physical properties of the molded product are required, the aliphatic Most polyesters have a melting point of 100 ° C. or less, and furthermore have poor thermal stability upon melting, and more importantly, the properties of this aliphatic polyester, particularly its mechanical properties represented by tensile strength. However, even at the same level of the number average molecular weight as the above polyethylene terephthalate, it showed only a remarkably inferior value, and it is considered that it was difficult to give a concept to obtain a molded product requiring strength and the like. Further, it is inferred that one of the reasons is that the study for further improving the physical properties by further increasing the number average molecular weight of the aliphatic polyester has not sufficiently progressed due to poor thermal stability.

[0004]

SUMMARY OF THE INVENTION The present invention uses these aliphatic polyesters as components, has a practically sufficient high molecular weight, and is excellent in mechanical properties represented by thermal stability and tensile strength. It is another object of the present invention to provide a packing band that is biodegradable as one of disposal means, that is, can be decomposed by microorganisms and the like, and is easily disposed after use.

[0005]

As a result of various studies on the reaction conditions for obtaining a polyester having a high molecular weight and sufficient practicality in packing band for packaging, the present inventors have found that
A specific aliphatic polyester having a practically sufficient high molecular weight is obtained while maintaining biodegradability, and a packing band molded from this is excellent not only in the above biodegradability but also in thermal stability and mechanical strength. And completed the present invention.

That is, the gist of the present invention is as follows.
° C, the melt viscosity at a shear rate of 100 sec ^-1 is 1.0
× 10 ^{3 to} 4.0 × 10 ⁴ poise, with a melting point of 70 to
A packing band formed by extrusion molding an aliphatic polyester at 190 ° C. as a main component, wherein (B) the aliphatic polyester has a number average molecular weight of 10,000 or more, and
(A) a packing band containing a urethane bond of 3.0% by weight, (C) a number average molecular weight of 5,000 or more and a melting point of 60
(A) or (B) a packing band comprising an aliphatic polyester obtained by reacting 0.1 to 5 parts by weight of a diisocyanate with 100 parts by weight of an aliphatic polyester prepolymer at a temperature of 100 ° C. or higher. It is in. Hereinafter, the contents of the present invention will be described in detail.

The aliphatic polyester referred to in the present invention includes two components of glycols and a polybasic acid (or an acid anhydride thereof) or, if necessary, three components as a third component.
Polyester obtained by adding and reacting at least one polyfunctional component selected from functional or tetrafunctional polyhydric alcohols, oxycarboxylic acids and polycarboxylic acids (or acid anhydrides thereof) In this method, a relatively high molecular weight polyester prepolymer having a hydroxyl group at the terminal of the molecule is produced, and this is further increased in molecular weight by a coupling agent.

Conventionally, a low molecular weight polyester prepolymer having a number average molecular weight of 2,000 to 2,500 having a hydroxyl group as a terminal group is reacted with a diisocyanate as a coupling agent to form a polyurethane, Foams, paints and adhesives are widely used. However, polyester prepolymers used for these polyurethane foams, paints and adhesives are:
The maximum number average molecular weight that can be synthesized without a catalyst is 2,0
It is a low molecular weight prepolymer of 100 to 2,500, and in order to obtain practical physical properties as a polyurethane with respect to 100 parts by weight of the low molecular weight prepolymer, the amount of diisocyanate used is 10 to 20 parts by weight. When such a large amount of diisocyanate is added to a low-molecular-weight polyester melted at 150 ° C. or higher, gelation occurs and a normal melt-moldable resin cannot be obtained.
Therefore, a polyester obtained by using such a low molecular weight polyester prepolymer as a raw material and reacting a large amount of diisocyanate cannot be used as a raw material for a packing band of the present invention.

As in the case of polyurethane rubber, a method of converting a hydroxyl group into an isocyanate group by adding a diisocyanate and further increasing the number average molecular weight with a glycol may be considered. As described above, the amount is 10 parts by weight or more based on 100 parts by weight of the prepolymer, so that practical properties are obtained. If a polyester prepolymer having a relatively high molecular weight is to be used, the heavy metal catalyst required for the synthesis of the prepolymer significantly promotes the reactivity of the isocyanate group used in the above amount, resulting in poor storage stability, crosslinking reaction, and branching. Since the formation of the polyester prepolymer is unfavorable because it is not preferable, if the polyester prepolymer synthesized without a catalyst is used, the number average molecular weight is limited to about 2,500 even if it is high.

The polyester prepolymer for obtaining the aliphatic polyester used in the present invention has a relatively high molecular weight as described above containing a catalyst for the synthesis thereof,
A saturated aliphatic polyester having a terminal group substantially a hydroxyl group, a relatively high molecular weight having a number average molecular weight of 5,000 or more, preferably 10,000 or more, and a melting point of 60 ° C. or more; And a polybasic acid (or an anhydride thereof) in a catalytic reaction. When the number average molecular weight is less than 5,000, for example, about 2,500, a small amount of the coupling agent of 0.1 to 5 parts by weight used in the present invention can provide a polyester for a packing band having good physical properties. Can not. Number average molecular weight is 5,000
The above polyester prepolymer has a hydroxyl value of 30 or less, and is free from a gel during the reaction because it is not affected by the remaining catalyst even under severe conditions such as a molten state by using a small amount of a coupling agent. , A high molecular weight polyester can be synthesized.

That is, the polymer constituting the packing band of the present invention has a number average molecular weight (Mn) comprising an aliphatic glycol and an aliphatic dicarboxylic acid of 5,000 or more, preferably 10,000 or more, and a melting point of 60 ° C. The above polyester prepolymer has a structure linked via a urethane bond derived from diisocyanate as a coupling agent, for example. Furthermore, the polymer constituting the packing band of the present invention is such that the polyester prepolymer has a long-chain branch derived from a polyfunctional component, and this forms, for example, a urethane bond derived from diisocyanate as a coupling agent. It has a structure that is linked via When an oxazoline, a diepoxy compound, or an acid anhydride is used as a coupling agent, the polyester prepolymer takes a chain structure via an ester bond.

The glycols used include, for example, ethylene glycol, 1,4-butanediol, 1,6
-Hexanediol, decamethylene glycol, neopentyl glycol, 1,4-cyclohexanedimethanol and the like. Ethylene oxide can also be used. These glycols may be used in combination.

Polybasic acids (or their anhydrides) which react with glycols to form aliphatic polyesters include:
Succinic acid, adipic acid, suberic acid, sebacic acid, dodecanoic acid, succinic anhydride, adipic anhydride, and the like are generally commercially available and can be used in the present invention. Polybasic acids (or acid anhydrides thereof) may be used in combination.

(Third component) In addition to these glycols and dicarboxylic acids, if necessary, as a third component, a trifunctional or tetrafunctional polyhydric alcohol, oxycarboxylic acid and polycarboxylic acid ( Or its acid anhydride)
And at least one kind of polyfunctional component selected from the above may be reacted. By adding this third component, long-chain branching occurs in the molecule, so that the molecular weight is increased and Mw is increased.
/ Mn increases, that is, the molecular weight distribution increases,
Desirable properties can be imparted to film forming and the like. The amount of the polyfunctional component to be added is 0.1 in the case of trifunctional with respect to 100 mol% of all components of the aliphatic dicarboxylic acid (or an acid anhydride thereof) so that there is no danger of gelling. 1 to 5 mol%, and 0.1 to
3 mol%.

(Polyfunctional Component) Examples of the polyfunctional component used as the third component include trifunctional or tetrafunctional polyhydric alcohols, oxycarboxylic acids and polycarboxylic acids. The trifunctional polyhydric alcohol component is typically trimethylolpropane, glycerin or its anhydride, and the tetrafunctional polyhydric alcohol component is pentaerythritol.

The trifunctional oxycarboxylic acid component comprises (i)
There are two types of carboxyl groups and one hydroxyl group in the same molecule, and (ii) a type having one carboxyl group and two hydroxyl groups. In terms of being available at
Malic acid which shares two carboxyl groups and one hydroxyl group in the same molecule of (i) is practically advantageous and sufficient for the purpose of the present invention. There are the following three types of tetrafunctional oxycarboxylic acid components. That is, (i)
A type sharing three carboxyl groups and one hydroxyl group in the same molecule, (ii) a type sharing two carboxyl groups and two hydroxyl groups in the same molecule, and (iii) three types. There is a type in which a hydroxyl group and one carboxyl group are shared in the same molecule, and any type can be used. However, from the viewpoint that a commercially available product can be easily obtained at low cost, citric acid And
Tartaric acid is practically advantageous and is sufficient for the purposes of the present invention.

As the trifunctional polycarboxylic acid (or an acid anhydride thereof) component, for example, trimesic acid, propanetricarboxylic acid or the like can be used, but trimellitic anhydride is advantageous from a practical viewpoint. Is sufficient for the purpose. Tetrafunctional polycarboxylic acid (or its acid anhydride)
There are various types such as aliphatic, cycloaliphatic, and aromatic in the literature, but from the viewpoint that commercially available products can be easily obtained, for example, pyromellitic anhydride, benzophenonetetracarboxylic anhydride, cyclopentane Tetracarboxylic anhydrides are mentioned and are sufficient for the purposes of the present invention.

These glycols and polybasic acids are mainly composed of aliphatic compounds, but may be used in combination with a small amount of other components such as aromatic compounds. However, if other components are introduced, the biodegradability deteriorates, so the content is 20% by weight or less, preferably 10% by weight or less, more preferably 5% by weight or less.

The polyester prepolymer for aliphatic polyester used in the present invention has a terminal group substantially a hydroxyl group. For this purpose, glycols and polybasic acids (or acid anhydrides thereof) used in the synthesis reaction are used. Requires that the glycols be used in some excess.

In order to synthesize a polyester prepolymer having a relatively high molecular weight, it is necessary to use a deglycol-reaction catalyst during the deglycolization reaction following the esterification.

Examples of the deglycol-reaction catalyst include titanium compounds such as acetoacetoyl-type titanium chelate compounds and organic alkoxytitanium compounds.
These titanium compounds can be used in combination. Examples of these include diacetacetoxyoxytitanium ("Narcem Titanium" manufactured by Nippon Chemical Industry Co., Ltd.), tetraethoxytitanium, tetrapropoxytitanium, tetrabutoxytitanium and the like. The use ratio of the titanium compound is 0.00% with respect to 100 parts by weight of the polyester prepolymer.
The amount is 1 to 1 part by weight, preferably 0.01 to 0.1 part by weight. The titanium compound may be added from the beginning of the esterification, or may be added immediately before the deglycolization reaction.

Further, the number average molecular weight is 5,000 or more,
Desirably, a coupling agent is used to further increase the number average molecular weight of the polyester prepolymer in which 10,000 or more terminal groups are substantially hydroxyl groups. Examples of the coupling agent include diisocyanates, oxazolines, diepoxy compounds, acid anhydrides and the like, with diisocyanates being particularly preferred. In the case of an oxazoline or diepoxy compound, it is necessary to react a hydroxyl group with an acid anhydride or the like and convert the terminal to a carboxyl group before using a coupling agent. The type of diisocyanate is not particularly limited, and examples thereof include 2,4-tolylene diisocyanate, a mixture of 2,4-tolylene diisocyanate and 2,6-tolylene diisocyanate, and diphenylmethane diisocyanate. , 1,
5-naphthylene diisocyanate, xylylene diisocyanate, hydrogenated xylylene diisocyanate, hexamethylene diisocyanate, and isophorone diisocyanate. Is preferred from the viewpoint of the reactivity and the like.

The amount of the coupling agent to be added is 0.1 to 5 parts by weight, preferably 0.5 to 3 parts by weight, based on 100 parts by weight of the polyester prepolymer. If the amount is less than 0.1 part by weight, the coupling reaction is insufficient. If the amount exceeds 5 parts by weight, gelation is liable to occur.

The addition is desirably carried out under conditions in which the polyester prepolymer is in a uniform molten state and can be easily stirred. It is not impossible to add to the solid polyester prepolymer and melt and mix through an extruder, but it is added to the aliphatic polyester production equipment or to the molten polyester prepolymer (for example, in a kneader). It is practical to do.

In order to extrude the aliphatic polyester used in the present invention into a packing band, specific melting properties are required. That is, the melt viscosity at a temperature of 190 ° C. and a shear rate of 100 sec ⁻¹ is 1.0 × 10 ³ to
4.0 × 10 ⁴ poise, and 3.0 × 10 ^{3 to} 3.0
× 10 ⁴ poise is particularly preferred. If the poise is less than 1.0 × 10 ³ poise, the tape-shaped material fluctuates greatly during melt extrusion, and a stable tape width and sufficient physical properties cannot be obtained. On the other hand, if it exceeds 4.0 × 10 ⁴ poise, it is difficult to stretch the tape-like material after melt extrusion, or only a low stretch ratio is obtained. The melt viscosity was measured at a shear rate of 100 sec ^-1 from a graph of the relationship between the shear rate measured at a resin temperature of 190 ° C. and the apparent viscosity using a nozzle having a nozzle diameter of 1.0 mm and a nozzle of L / D = 10. The viscosity was determined.

Further, the melting point of the aliphatic polyester used in the present invention needs to be 70 to 190 ° C., more preferably 70 to 150 ° C., and particularly preferably 80 to 135 ° C. If it is lower than 70 ° C., the heat resistance is insufficient, and if it is higher than 190 ° C., it is difficult to manufacture.
In order to obtain a melting point of 70 ° C. or more, the melting point of the polyester prepolymer needs to be 60 ° C. or more.

When the aliphatic polyester used in the present invention contains a urethane bond, the amount of the urethane bond is 0.03 to 3.0% by weight, preferably 0.05 to 2.0% by weight, 0.1 to 1.0% by weight is particularly preferred. The urethane bond amount is measured by C ₁₃ NMR and agrees well with the charged amount. When the amount is less than 0.03% by weight, the effect of increasing the molecular weight by urethane bonds is small, and the moldability is poor. When the amount exceeds 3.0% by weight, a gel is generated.

In using the above aliphatic polyester for band forming according to the present invention, if necessary, in addition to antioxidants, heat stabilizers, ultraviolet absorbers, etc., lubricants, waxes, coloring agents, crystals, etc. Needless to say, a chemical accelerator, a reinforcing fiber and the like can be used in combination. That is, as an antioxidant,
Heat stabilizers such as hindered phenolic antioxidants such as pt-butylhydroxytoluene and pt-butylhydroxyanisole; sulfur-based antioxidants such as distearylthiodipropionate and dilaurylthiodipropionate; , Triphenyl phosphite, trilauryl phosphite, trisnonyl phenyl phosphite, etc.
Examples of ultraviolet absorbers include pt-butylphenyl salicylate, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-methoxy-2′-carboxybenzophenone, 2,4,5-trihydroxybutyrophenone, and the like. Include, but are not limited to, calcium stearate, zinc stearate, barium stearate, sodium palmitate and the like; antistatic agents such as N, N-bis (hydroxyethyl) alkylamine, alkylamine, alkylallyl sulfonate, and alkyl sulfonate; Examples of the flame retardant include hexabromocyclododecane, tris- (2,3-dichloropropyl) phosphate, pentabromophenyl allyl ether and the like.

The raw material containing an aliphatic polyester as a main component used in the present invention is usually melt-extruded, cooled with water, and thermally stretched, and then pressed by a pair of embossing rolls to form a band. The melting temperature is 170-240 ° C, preferably 180-190 ° C. If the temperature is less than 170 ° C., the tape-shaped material tends to be cut during melt extrusion from the die orifice,
On the other hand, when the temperature exceeds 240 ° C., the tape fluctuates greatly and cutting is liable to occur. The stretching may be performed in any of a wet stretching tank, an oven, a hot roll, etc., but the stretching temperature is 50 to 100.
° C, preferably 70-90 ° C. If the temperature is lower than 50 ° C., the film is difficult to be stretched. The embossing by the embossing roll is usually performed for preventing vertical cracking or annealing, but may be omitted in some cases. In the case of embossing, either one side unevenness or both side unevenness may be used.

The aliphatic polyester used in the present invention has a number average molecular weight of 10,000 or more, preferably 20,000.
0 or more, and the bonding by the coupling agent is extremely small. Further, if the melting point is 70 to 190 ° C. or more and the crystallinity is obtained, a tough packing band can be obtained and can be used for various kinds of packing.

[0031]

The present invention will be described below with reference to examples and comparative examples. In the following examples, the evaluation method is as follows. Adhesiveness: Indicates the strength of the adhesive force immediately after the bonding operation. (Using a packing machine S-200 manufactured by Masahiro Kiko Co., Ltd., three weekly magazines were packed and observed.) Longitudinal cracking resistance; vertical cracking including the bonded part and cut part of the band after packing 3 shows the resistance state. Unpacking property: indicates the ease of peeling and peeling of the bonded portion by human hands. Adhesive strength (kg): The tensile strength is measured by pulling at a tensile speed of 20 cm / min in a direction in which shear stress acts on the adhesive. Biodegradability; change in practical tensile strength after burying in soil for a predetermined period is felt.

Example 1 A 700 L reactor was replaced with nitrogen, and 183 kg of 1,4-butanediol and 224 kg of succinic acid were charged. Raise the temperature under a nitrogen stream and
3.5 hours at 92-220 ° C.
The esterification reaction by dehydration condensation was performed for 3.5 hours under reduced pressure of 0 to 2 mmHg. The collected sample is
The acid value is 9.2 mg / g, and the number average molecular weight (Mn) is 5.1.
60 and the weight average molecular weight (Mw) was 10,670. Subsequently, 34 g of tetraisopropoxy titanium as a catalyst was added under a nitrogen stream at normal pressure. Raise the temperature,
A deglycol-reaction was performed at a temperature of 215 to 220 ° C. under a reduced pressure of 15 to 0.2 mmHg for 5.5 hours. The collected sample had a number average molecular weight (Mn) of 16,800 and a weight average molecular weight (Mw) of 43,600. The yield of this polyester (A1) is 339 k excluding condensed water.
g.

To a reactor containing 339 kg of polyester (A1), 5.42 kg of hexamethylene diisocyanate was added, and a coupling reaction was carried out at 180 to 190 ° C. for 1 hour. The viscosity increased rapidly but no gelling occurred. Then, Irganox 1010 was used as an antioxidant.
1.70 kg (manufactured by Ciba Geigy) and 1.70 kg of calcium stearate as a lubricant were added, and stirring was further continued for 30 minutes. This reaction product was extruded into water with an extruder and cut into a pellet by a cutter. The yield of the polyester (B1) after vacuum drying at 90 ° C. for 6 hours was 300 kg.

The obtained polyester (B1) is a slightly ivory white wax-like crystal having a melting point of 110.
° C, the number average molecular weight (Mn) is 35,500, the weight average molecular weight (Mw) is 170,000, the MFR (190 ° C) is 1.0 g / 10 min, the viscosity of a 10% solution of orthochlorophenol is 230 poise, Temperature 190 ° C, shear rate 10
The melt viscosity at ⁰ sec ^-1 was 1.5 × 10 ⁴ poise. The average molecular weight is measured by Shodex GPC
System-11 (Showa Denko KK gel chromatography), solvent of CF ₃ COONa HFIPA5m
mol solution, concentration 0.1 wt%, calibration curve is Showa Denko KK PMMA standard sample ShodexStand
ard M-75.

Polyester (B1) is molded at 230 ° C.
Then, it was melt-extruded from a 1.4 mm × 16 mm die orifice of a 55 mmφ extruder, and cooled to 80 ° C. in a water bath at room temperature.
And stretched 6 times through a heating tank. Thereafter, the mixture was heated and pressed by a pair of embossing rolls (diamond shape having one-sided irregularities) to obtain a packing band. The band had a width of 6 mm and a thickness of 0.3 mm, and the adhesion, longitudinal cracking resistance, unpacking property, and adhesive strength of each example were examined. Table 1 shows the results. When the obtained packing band was buried in soil for 5 months, it was decomposed and changed to a tensile strength that was not practically usable.

Example 2 Polyester (B1) was molded at a molding temperature of 170 ° C. and 1.4 mm × 16 mm in a 55 mmφ extruder.
It was melt-extruded through a die orifice having a diameter of 2 mm, cooled in a water bath at room temperature, and then stretched 6-fold through a heating bath at 80 ° C. Thereafter, the mixture was heated and pressed by a pair of embossing rolls (diamond shape having one-sided irregularities) to obtain a packing band. The band has a width of 6 mm and a thickness of 0.3 mm.
It was 3 mm, and the adhesiveness, longitudinal crack resistance, unpacking property, and adhesive strength were examined for each example. Table 1 shows the results.

Example 3 A polyester (B1) was molded at a molding temperature of 230 ° C. and a 55 mmφ extruder at 1.4 mm × 16.
The mixture was melt-extruded from a die orifice having a diameter of 2 mm, cooled in a water bath at room temperature, and then stretched 6 times through a heating bath at 90 ° C. Thereafter, the mixture was heated and pressed by a pair of embossing rolls (diamond shape having one-sided irregularities) to obtain a packing band. The band has a width of 6 mm and a thickness of 0.3 mm.
It was 3 mm, and the adhesiveness, longitudinal crack resistance, unpacking property, and adhesive strength were examined for each example. Table 1 shows the results. When the obtained packing band was buried in the soil for 5 months, it was decomposed and changed to a state having no practical strength.

Example 4 A 700 L reactor was purged with nitrogen and charged with 177 kg of 1,4-butanediol, 198 kg of succinic acid and 25 kg of adipic acid. The temperature is increased under a nitrogen stream, and the temperature is increased to 190 to 210 ° C. for 3.5 hours.
2. Further stop nitrogen, and under a reduced pressure of 20 to 2 mmHg.
The esterification reaction by dehydration condensation was performed for 5 hours. The collected sample had an acid value of 9.6 mg / g, a number average molecular weight (Mn) of 6,100, and a weight average molecular weight (M
w) was 12,200. Subsequently, 20 g of tetraisopropoxytitanium as a catalyst was added under a nitrogen stream at normal pressure. Raise the temperature, 15 ~
The glycol removal reaction was performed under a reduced pressure of 0.2 mmHg for 6.5 hours. The collected sample is number average molecular weight (Mn)
Is 17,300, and the weight average molecular weight (Mw) is 46,
400. The yield of this polyester (A2) was 337 kg excluding condensed water.

4.66 kg of hexamethylene diisocyanate was added to a reactor containing 333 kg of polyester (A2), and a coupling reaction was carried out at 180 to 190 ° C. for 1 hour. The viscosity increased rapidly but no gelling occurred. Then, Irganox 1010 was used as an antioxidant.
1.70 kg (manufactured by Ciba Geigy) and 1.70 kg of calcium stearate as a lubricant were added, and stirring was further continued for 30 minutes. This reaction product was extruded into water with an extruder and cut into a pellet by a cutter. The yield of the polyester (B2) after vacuum drying at 90 ° C. for 6 hours was 300 kg.

The obtained polyester (B2) is a slightly ivory white wax-like crystal having a melting point of 103.
° C, number average molecular weight (Mn) is 36,000, weight average molecular weight (Mw) is 200,900, MFR (190 ° C) is 0.52 g / 10 min, and 10% of orthochlorophenol.
The solution has a viscosity of 680 poise, a temperature of 190 ° C. and a shear rate of 1.
The melt viscosity at 00 sec ^-1 was 2.2 × 10 ⁴ poise.

Polyester (B2) is molded at 230 ° C.
Then, it was melt-extruded from a 1.4 mm × 16 mm die orifice of a 55 mmφ extruder, and cooled to 80 ° C. in a water bath at room temperature.
And stretched 6 times through a heating tank. Thereafter, the mixture was heated and pressed by a pair of embossing rolls (diamond shape having one-sided irregularities) to obtain a packing band. The band had a width of 6 mm and a thickness of 0.3 mm, and the adhesion, longitudinal cracking resistance, unpacking property, and adhesive strength of each example were examined. Table 1 shows the results. When the obtained packing band was buried in the soil for 5 months, the tensile strength was hardly practical.

Example 5 Polyester (B2) was molded at a molding temperature of 170 ° C. and a 55 mmφ extruder at 1.4 mm × 16 mm.
It was melt-extruded through a die orifice having a diameter of 2 mm, cooled in a water bath at room temperature, and then stretched 6-fold through a heating bath at 80 ° C. Thereafter, the mixture was heated and pressed by a pair of embossing rolls (diamond shape having one-sided irregularities) to obtain a packing band. The band has a width of 6 mm and a thickness of 0.3 mm.
It was 3 mm, and the adhesiveness, longitudinal crack resistance, unpacking property, and adhesive strength were examined for each example. When the obtained packing band was buried in soil for 5 months, the band was decomposed and changed to a state without practical tensile strength.

Example 6 Polyester (B2) was molded at a molding temperature of 230 ° C. and 55 mmφ extruder at 1.4 mm × 16.
The mixture was melt-extruded from a die orifice having a diameter of 2 mm, cooled in a water bath at room temperature, and then stretched 6 times through a heating bath at 90 ° C. Thereafter, the mixture was heated and pressed by a pair of embossing rolls (diamond shape having one-sided irregularities) to obtain a packing band. The band has a width of 6 mm and a thickness of 0.3 mm.
It was 3 mm, and the adhesiveness, longitudinal crack resistance, unpacking property, and adhesive strength were examined for each example. Table 1 shows the results. When the obtained packing band was buried in the soil for 5 months, the band was decomposed and changed to a level of no practical strength.

(Example 7) After replacing a 700 L reactor with nitrogen, 145 kg of ethylene glycol and succinic acid 2 were added.
51 kg and 4.1 kg of citric acid were charged. The temperature was raised under a nitrogen stream, and the esterification reaction by dehydration condensation was performed at 190 to 210 ° C. for 3.5 hours, and further with the nitrogen stopped, under a reduced pressure of 20 to 2 mmHg for 5.5 hours. The collected sample had an acid value of 8.8 mg / g, a number average molecular weight (Mn) of 6,800, and a weight average molecular weight (Mw) of 13,500. Subsequently, 20 g of tetraisopropoxytitanium as a catalyst was added under a nitrogen stream at normal pressure.
Raise the temperature to 15-0.2 at a temperature of 210-220 ° C.
The glycol removal reaction was performed under reduced pressure of mmHg for 4.5 hours. The sample collected had a number average molecular weight (Mn) of 3
3,400, and a weight average molecular weight (Mw) of 137,0
00. The yield of this polyester (A3) was 323 kg excluding condensed water.

3.23 kg of hexamethylene diisocyanate was added to a reactor containing 323 kg of polyester (A3), and a coupling reaction was carried out at 180 to 190 ° C. for 1 hour. The viscosity increased rapidly but no gelling occurred. Then, Irganox 1010 was used as an antioxidant.
1.62 kg (manufactured by Ciba Geigy) and 1.62 kg of calcium stearate as a lubricant were added, and stirring was further continued for 30 minutes. This reaction product was extruded into water with an extruder and cut into a pellet by a cutter. The yield of the polyester (B3) after vacuum drying at 90 ° C. for 6 hours was 300 kg.

The obtained polyester (B3) is a slightly ivory white wax-like crystal having a melting point of 96 ° C.
The number average molecular weight (Mn) is 54,000, the weight average molecular weight (Mw) is 324,000, and the MFR (190 ° C.) is 1.
1 g / 10 min, viscosity of a 10% solution of orthochlorophenol is 96 poise, temperature 190 ° C., shear rate 100 sec.
The melt viscosity at c ^-1 was 1.6 × 10 ⁴ poise.

The polyester (B3) is molded at 230 ° C.
Then, it was melt-extruded from a 1.4 mm × 16 mm die orifice of a 55 mmφ extruder, and cooled to 80 ° C. in a water bath at room temperature.
And stretched 6 times through a heating tank. Thereafter, the mixture was heated and pressed by a pair of embossing rolls (diamond shape having one-sided irregularities) to obtain a packing band. The band had a width of 6 mm and a thickness of 0.3 mm, and the adhesion, longitudinal cracking resistance, unpacking property, and adhesive strength of each example were examined. Table 1 shows the results.

Example 8 A 700 L reactor was purged with nitrogen, and then 200 kg of 1,4-butanediol, 250 kg of succinic acid and 2.8 kg of trimethylolpropane were used.
Was charged. The temperature is increased under a nitrogen stream, and
At 4.5 ° C. for 4.5 hours, and further stop nitrogen for 20 to 2 mmH.
The esterification reaction by dehydration condensation was performed under reduced pressure of 5.5 g for 5.5 hours. The collected sample has an acid value of 10.
The number average molecular weight (Mn) was 4,900, and the weight average molecular weight (Mw) was 10,000. Subsequently, 37 g of tetraisopropoxytitanium as a catalyst was added under a nitrogen stream at normal pressure. Raise the temperature to 210
8.0 to 220 ° C. under reduced pressure of 15 to 1.0 mmHg.
The deglycol reaction was performed for a time. The collected sample had a number average molecular weight (Mn) of 16,900 and a weight average molecular weight (Mw) of 90,300. (Mw / Mn =
5.4). The yield of this polyester (A4) was 367 kg theoretically excluding 76 kg of condensed water.

3.67 kg of hexamethylene diisocyanate was added to a reactor containing 367 kg of polyester (A4), and a coupling reaction was performed at 160 to 200 ° C. for 1 hour. The viscosity increased rapidly but no gelling occurred. Then, Irganox 1010 was used as an antioxidant.
367 g (manufactured by Ciba Geigy) and 367 g of calcium stearate as a lubricant were added, and stirring was further continued for 30 minutes. This reaction product was extruded into water with an extruder and cut into a pellet by a cutter. 9
Polyester (B4) after vacuum drying at 0 ° C. for 6 hours
Was 350 kg.

The obtained polyester (B4) is a slightly ivory white wax-like crystal having a melting point of 110.
° C, the number average molecular weight (Mn) is 17,900, and the weight average molecular weight (Mw) is 161,500 (Mw / Mn = 9.
0), the MFR (190 ° C.) was 0.21 g / 10 min, the temperature was 180 ° C., and the melt viscosity at a shear rate of 1000 sec ⁻¹ was 2.0 × 10 ⁴ poise. The average molecular weight was measured by Shodex GPC System-11 (gel chromatography manufactured by Showa Denko KK), and the solvent was CF _3.
A 2 mmol solution of COONa in HIPPA, a concentration of 0.1% by weight, and a calibration curve were performed with a PMMA standard sample Shodex Standard M-75 manufactured by Showa Denko KK.

The polyester (B4) was molded at a molding temperature of 230 ° C.
Then, it was melt-extruded from a 1.4 mm × 16 mm die orifice of a 55 mmφ extruder, and cooled to 80 ° C. in a water bath at room temperature.
And stretched 6 times through a heating tank. Thereafter, the mixture was heated and pressed by a pair of embossing rolls (diamond shape having one-sided irregularities) to obtain a packing band. The band had a width of 6 mm and a thickness of 0.3 mm, and the adhesion, longitudinal cracking resistance, unpacking property, and adhesive strength of each example were examined. Table 1 shows the results. When the obtained packing band was buried in soil for 5 months, it was decomposed and changed to a tensile strength that was not practically usable.

(Comparative Example 1) A polyester (A1) was molded at a molding temperature of 230 ° C and a 55 mmφ extruder at 1.4 mm x 16 mm.
It was melt-extruded from a die orifice having a diameter of 2 mm, cooled in a water bath at room temperature, and then stretched through a heating bath at 80 ° C. The polyester (A1) was molded under the same conditions as in Example 1, but was broken in the middle of stretching by about 2 times, and the desired band could not be obtained. When the polyester A1 of the melt extruded product was buried in soil for 5 months, it was in the same state as Comparative Example 1.

[0053]

[Table 1]

[0054]

According to the present invention, a temperature of 190 ° C. and a shear rate of 10 are used.
The melt viscosity at ⁰ sec ^-1 is 1.0 × 10 ^{3 to} 4.0.
× 10 ⁴ poises, a packing band extruded from an aliphatic polyester having a melting point of 70 to 190 ° C. as a main component, particularly an aliphatic having a number average molecular weight of 5,000 or more and a melting point of 60 ° C. or more. Polyester prepolymer 10
A packing band obtained by reacting 0.1 to 5 parts by weight of diisocyanate with 0 part by weight and containing an aliphatic polyester as a main component has biodegradability when buried in soil or the like. Even after incineration, the calorific value of combustion is lower than that of polyethylene and polypropylene, and it is excellent in thermal stability, thermal adhesive strength, unpacking property and mechanical strength (vertical cracking, etc.) Useful as a band for

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code Agency reference number FI Technical display location B29K 67:00 (72) Inventor Akira Nakamura 3-2 Chidoricho, Kawasaki-ku, Kawasaki-shi, Kanagawa Showa Denko (72) Eiichiro Takiyama Inventor 4-12-4 Nishi-Kamakura, Kamakura City, Kanagawa Prefecture

Claims (9)

(57) [Claims] 1. A temperature of 190 ° C. and a shear rate of 100 sec ⁻¹
A packaging band formed by extruding an aliphatic polyester having a melt viscosity of 1.0 × 10 ^{3 to} 4.0 × 10 ⁴ poise and a melting point of 70 to 190 ° C. as a main component. 2. An aliphatic polyester having a number average molecular weight of 1
The packing band according to claim 1, which has a urethane bond of not less than 000 and 0.03 to 3.0% by weight. 3. An aliphatic obtained by reacting 0.1 to 5 parts by weight of diisocyanate with 100 parts by weight of an aliphatic polyester prepolymer having a number average molecular weight of 5,000 or more and a melting point of 60 ° C. or more. The packing band according to claim 1 or 2, wherein the packing band is made of polyester. 4. The aliphatic polyester has a number average molecular weight (Mn) comprising an aliphatic glycol and an aliphatic dicarboxylic acid.
The packing band according to claim 1 or 2, wherein the packaging band has a structure in which 5,000 or more polyester prepolymers are linked via a urethane bond. 5. The aliphatic polyester is at least one polyfunctional selected from aliphatic glycols, aliphatic dicarboxylic acids and trifunctional or tetrafunctional polyhydric alcohols, oxycarboxylic acids and polycarboxylic acids or anhydrides thereof. Number average molecular weight (Mn) obtained by adding components and reacting
The packing band according to claim 1 or 2, wherein the packaging band has a structure in which 5,000 or more polyester prepolymers are linked via a urethane bond. 6. The polyester prepolymer is selected from the group consisting of ethylene glycol, 1,4-butanediol, 1,6-hexanediol, decamethylene glycol, neopentyl glycol and 1,4-cyclohexanedimethanol as glycol units. The dicarboxylic acid unit has a unit selected from the group consisting of succinic acid, adipic acid, suberic acid, sebacic acid, dodecanoic acid, succinic anhydride, and adipic anhydride.
Or the packing band of Claim 5. 7. The polyester prepolymer contains, as a third component, at least one selected from the group consisting of trimethylolpropane, glycerin and pentaerythritol as a trifunctional or tetrafunctional polyhydric alcohol. Packing band described in. 8. The polyester prepolymer as a trifunctional or tetrafunctional oxycarboxylic acid as a third component,
1 selected from the group consisting of malic acid, citric acid and tartaric acid
7. The packing band according to claim 6, comprising at least one species. 9. The polyester prepolymer is a trifunctional or tetrafunctional polycarboxylic acid as a third component, such as trimesic acid, propanetricarboxylic acid, trimellitic anhydride, pyromellitic anhydride, benzophenonetetracarboxylic anhydride and The packing band according to claim 6, comprising one or more members selected from the group consisting of cyclopentanetetracarboxylic anhydride.