JP2747195B2 - Polyester biaxially stretched hollow molded body - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a biaxial biaxial polymer having excellent thermal stability and mechanical strength using an aliphatic polyester having a biodegradable, practically sufficient high molecular weight and specific melting characteristics. The present invention relates to a stretched hollow molded article.

[0002]

2. Description of the Related Art In recent years, plastic molding containers have been developed for industrial use and household use in terms of productivity, versatility, fashionability, chemical resistance and rust prevention. Waste plastics, rivers,
It has the potential to contaminate the oceans and soil, and has become a major social problem. For the prevention of this pollution, the emergence of biodegradable plastics has been anticipated. (3-Hydroxybutyrate) and blends of starch, which is a blend-type natural polymer, and general-purpose plastics are known. However, the former has a drawback in that since the thermal decomposition temperature of the polymer is close to the melting point, the molding processability is inferior, and microorganisms create the raw material unit, which is very poor. In the latter case, since the natural polymer itself is not thermoplastic, moldability is difficult and the range of use 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, ε-caprolactone has been found to have a high molecular weight by ring-opening polymerization, and has been proposed as a biodegradable resin. However, the melting point is as low as 62 ° C. ing. Glycolic acid and lactic acid also have high molecular weights obtained by ring-opening polymerization of glycolide and lactide, and are slightly used for medical fibers, etc. It has not been used in large quantities in biaxially stretched hollow containers.

[0003] The high molecular weight polyester (herein, high molecular weight polyester means a number average molecular weight of 10,000 or more) usually used for molding these industrial and household biaxially stretched hollow molded articles is It is no exaggeration to say that it is limited to polyethylene terephthalate, which is a condensate of terephthalic acid (including dimethyl terephthalate) and ethylene glycol. 2,6 instead of terephthalic acid
-There are examples using naphthalenedicarboxylic acid, but in any case, attempts to impart biodegradability have not yet been reported. Therefore, it can be said that there is no idea that a biaxially stretched hollow molded article is to be formed from a biodegradable aliphatic polyester using an aliphatic type dicarboxylic acid as a conventional dicarboxylic acid and put to practical use. One of the reasons why this idea of practical use has not been born is that plastic biaxially stretched hollow molded articles are crystalline, despite the special molding conditions and physical properties required of molded articles. Also, the melting point of the aliphatic polyester is 100
° C or less, and furthermore, the thermal stability at the time of melting is poor, and more importantly, the properties of the aliphatic polyester, particularly the mechanical properties represented by the tensile strength, are higher than those of the polyethylene terephthalate. Even at a number average molecular weight of the same level as above, it shows only a remarkably inferior value, and it is considered that it was difficult to give an idea 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. Another object of the present invention is to provide a biaxially stretched hollow molded body which is biodegradable as one of the disposal means, that is, can be decomposed by microorganisms or the like, and is easily disposed after use.

[0005]

Means for Solving the Problems The present inventors have conducted various studies on the reaction conditions for obtaining a polyester having the moldability of a biaxially stretched hollow molded article having a high molecular weight and sufficient practicality. While retaining the degradability, a specific aliphatic polyester having a practically sufficient high molecular weight is obtained, and the biaxially stretched hollow molded article molded therefrom has not only the above-mentioned biodegradability but also thermal stability and mechanical strength And found that the present invention was completed.

That is, the gist of the present invention is as follows.
C. and a melt viscosity at a shear rate of 100 sec ^-1 is 3.0.
× 10 ^{3 to} 2.0 × 10 ⁵ poise, with a melting point of 70 to
A biaxially stretched hollow molded article made of an aliphatic polyester at 190 ° C., (B) an aliphatic polyester having a number average molecular weight of 1
(A) a biaxially stretched hollow molded article having a urethane bond content of 0.03 to 3.0% by weight and having a number average molecular weight of 5,000 or more and a melting point of 60 ° C. or more. 0.1 to 100 parts by weight of the aliphatic polyester prepolymer
(A) or (B) a biaxially stretched hollow molded article made of an aliphatic polyester obtained by reacting 5 parts by weight of a diisocyanate, and (D) a tensile breaking strength of 3
20 kg / cm ² or more, elongation at break of 300% or more, rigidity of 3000 kg / cm ² or more, and measured by a press 23
Notched Izod impact strength at 1.0 ° C is 1.0kg
(A), (B) or (C) which is at least cm / cm ²
In the biaxially stretched hollow molded article. Hereinafter, the contents of the present invention will be described in detail.

The aliphatic polyester referred to in the present invention is a trifunctional or tetrafunctional polyfunctional component comprising a glycol and a dicarboxylic acid (or an acid anhydride thereof) as two components or, if necessary, a third component. A polyester obtained by adding and reacting at least one polyfunctional component selected from a polyhydric alcohol, an oxycarboxylic acid and a polycarboxylic acid (or an acid anhydride thereof) as a main component; A polyester prepolymer having a relatively high molecular weight and having a hydroxyl group is prepared, 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 biaxially stretched hollow molded article 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 it is not preferable to use a polyester prepolymer synthesized without a catalyst as a polyester prepolymer, the number average molecular weight is limited to about 2,500 at the highest even if it is high.

The polyester prepolymer for obtaining the aliphatic polyester used in the present invention has a terminal group substantially a hydroxyl group and a number average molecular weight of 5,000.
As described above, a saturated aliphatic polyester having a relatively high molecular weight of preferably 10,000 or more and a melting point of 60 ° C. or more, which is obtained by a catalytic reaction between glycols and a dicarboxylic acid (or an acid anhydride thereof). . Number average molecular weight is 5,
When it is less than 000, for example, about 2,500, a small amount of coupling agent of 0.1 to 5 parts by weight used in the present invention cannot obtain a polyester for a biaxially stretched hollow molded article having good physical properties. . Number average molecular weight is 5,000
A polyester prepolymer of 0 or more has a hydroxyl value of 30 or less and, even when used in a severe condition such as a molten state, is not affected by the remaining catalyst, and may form a gel during the reaction, even under severe conditions such as a molten state. And a high molecular weight polyester can be synthesized.

Examples of the glycol used include aliphatic glycols, particularly those having 2 or 4 carbon atoms.
6, 8 and 10 having even-numbered linear alkylene groups, such as ethylene glycol, 1,4-butanediol, 1,6-hexanediol, 1,8-octanediol, 1,10-decanediol, As well as mixtures thereof. Among them, those having a small number of carbon atoms, for example, ethylene glycol, 1,4-butanediol, and 1,6-hexanediol are preferable because an aliphatic polyester having a high crystallinity and a high melting point can be synthesized. In particular, ethylene glycol and 1,4-butanediol are most suitable since they give good results.

In order to form an aliphatic polyester by reacting with a glycol, an aliphatic dicarboxylic acid or an acid anhydride thereof is used, and particularly, an aliphatic dicarboxylic acid having 2, 4, 6, 8 carbon atoms.
And even 10 linear alkylene groups such as succinic acid, adipic acid, suberic acid, sebacic acid,
Preferred are 10-decanedicarboxylic acid, succinic anhydride, and mixtures thereof. Among them, those having a small number of carbon atoms, for example, succinic acid, adipic acid, and succinic anhydride are more preferable because polyethylene having a high crystallinity and a high melting point can be synthesized. In particular succinic or succinic anhydride, and these and other dicarboxylic acids, such as adipic acid, suberic acid,
Most preferred is a mixed acid with sebacic acid and 1,10-decanedicarboxylic acid. When the mixed acid is used, for example, a preferable mixing ratio of each component of a two-component system or more composed of succinic acid and another dicarboxylic acid is usually 7%.
0 mol% or more, preferably 90 mol% or more, and most preferably 30 mol% or less, preferably 10 mol% or less of dicarboxylic acids other than succinic acid. In particular, the combination of 1,4-butanediol and succinic acid or its anhydride, and the combination of ethylene glycol and succinic acid or its anhydride show a melting point similar to that of polyethylene, which is the most desirable combination for the present invention. It can be said that.

(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)
A type having two carboxyl groups and one hydroxyl group in the same molecule and a type (ii) having one carboxyl group and two hydroxyl groups in the same molecule are commercially available easily and at low cost. 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 In addition, tartaric acid is practically advantageous and is sufficient for the purpose 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. From the practical viewpoint, trimellitic anhydride is advantageous. Is enough. There are various types of tetrafunctional polycarboxylic acids (or acid anhydrides thereof) in the literature, such as aliphatic, cycloaliphatic, and aromatic, but from the viewpoint that commercially available products can be easily obtained, for example, Examples include pyromellitic anhydride, benzophenonetetracarboxylic anhydride, and cyclopentanetetracarboxylic anhydride, which are sufficient for the purpose of the present invention.

These glycols and polybasic acids are mainly composed of aliphatic compounds, but may be used in combination with small amounts 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 that purpose, the glycols and polybasic acids (or acid anhydrides) used in the synthesis reaction need to be used in a slightly excessive amount of glycols.

In order to synthesize a relatively high molecular weight polyester prepolymer, 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 0.001 to 100 parts by weight of the polyester prepolymer.
1 part by weight, desirably 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.
Particularly, diisocyanate is preferable. 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 the following types. 2,4-tolylene diisocyanate, a mixture of 2,4-tolylene diisocyanate and 2,6-tolylene diisocyanate, diphenylmethane diisocyanate, 1,5-naphthylene diisocyanate, xylylene diisocyanate, Hydrogenated xylylene diisocyanate, hexamethylene diisocyanate, and isophorone diisocyanate, particularly hexamethylene diisocyanate, are preferred from the viewpoint of the hue of the formed resin, the reactivity when adding polyester, 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, and if it 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 homogeneous 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.

The aliphatic polyester used in the present invention is required to have a specific melting property in order to carry out biaxial stretching blow molding. That is, the temperature is 190 ° C., and the shear rate is 100 seconds.
The melt viscosity at c ^-1 is 3.0 × 10 ^{3 to} 2.0 × 10 ^3
5 poise, preferably 7.0 × 10 ^{3 to} 3.0 ×
10 ⁴ poise, 1.2 × 10 ^{4 to} 2.3 × 10 ⁴ poise is particularly preferred. If it exceeds 2.0 × 10 ⁵ poise, a bottomed parison having a good appearance cannot be obtained, and if it is less than 3.0 × 10 ³ poise, the bottomed parison does not stretch uniformly and a good thick product cannot be obtained.

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 the temperature is lower than 70 ° C., the heat resistance is insufficient, and deformation during use becomes a problem.
Those exceeding 0 ° C. are difficult to manufacture. In order to obtain a melting point of 70 ° C. or more, the melting point of the polyester prepolymer is 60
It is necessary that the temperature be at least ° C.

In the case where 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, more preferably 0.1 to 2.0% by weight. Particularly preferred is 1 to 1.0% by weight.
The urethane bond amount is measured by C ₁₃ NMR and agrees well with the charged amount. If it is less than 0.03% by weight, the effect of increasing the molecular weight by the urethane bond is small, and the molding processability is poor,
If it exceeds 3.0% by weight, a gel is generated.

When using the above-mentioned aliphatic polyester to obtain the biaxially stretched hollow molded article according to the present invention, if necessary, other lubricants such as antioxidants, heat stabilizers and ultraviolet absorbers, waxes, It goes without saying that a coloring agent (colored pellets, dry color, master batch, etc.), a foaming agent, a crystallization accelerator, a reinforcing fiber and the like can be used in combination. That is, examples of the antioxidant include hindered phenol-based antioxidants such as pt-butylhydroxytoluene and pt-butylhydroxyanisole, and sulfur-based antioxidants such as distearylthiodipropionate and dilaurylthiodipropionate. And heat stabilizers such as triphenyl phosphite, trilauryl phosphite and trisnonylphenyl phosphite, and ultraviolet absorbers such as pt
-Butylphenyl salicylate, 2-hydroxy-4-
Methoxybenzophenone, 2-hydroxy-4-methoxy-2'-carboxybenzophenone, 2,4,5-trihydroxybutyrophenone and the like; lubricants such as calcium stearate, zinc stearate, barium stearate and sodium palmitate; Examples of the agent include N, N-bis (hydroxyethyl) alkylamine, alkylamine, alkylallylsulfonate, and alkylsulfonate. Examples of the flame retardant include hexabromocyclododecane, tris- (2,3-dichloropropyl) phosphate, As inorganic fillers such as pentabromophenyl allyl ether, calcium carbonate, silica,
Titanium oxide, talc, mica, barium sulfate, alumina, etc., as a crystallization accelerator, polyethylene terephthalate, poly-transcyclohexane dimethanol terephthalate, etc., as reinforcing fibers, glass fibers, carbon fibers,
Examples include inorganic fibers such as boron fiber, silicon carbide fiber, graphite fiber, alumina fiber, and amorphous fiber, and organic fibers such as aramid fiber.

The raw material containing aliphatic polyester as a main component used in the biaxially stretched hollow molded article according to the present invention includes an injection stretch hollow molding method, an extrusion stretch hollow molding method, and a cold parison stretch hollow by a biaxial stretch hollow molding method. It is made into a hollow product by a molding method or the like. In the case of the biaxial stretching blow molding, the resin temperature at the time of stretching the plasticized bottomed parison is 40 to 190.
° C, preferably 80 to 170 ° C. More preferably, it is 100 to 150 ° C. Above the melting point, the stretching effect is not exhibited. When the bottomed parison is stretched at a temperature lower than the crystallization temperature, the parison is not uniformly stretched and a good thick product cannot be obtained.

[0026]

The present invention will be described below with reference to examples and comparative examples. (Example 1) After replacing a 700 L reactor with nitrogen,
183 kg of 1,4-butanediol, 224 k of succinic acid
g. The temperature is increased under a nitrogen stream, and
At 0 ° C. for 3.5 hours, further stop nitrogen, and then 20 to 2 mm
The esterification reaction by dehydration condensation was performed under reduced pressure of Hg for 3.5 hours. The collected sample had an acid value of 9.
The number average molecular weight (Mn) was 5,160, 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 to 215
5.5 at 220 to 220 ° C under a reduced pressure of 15 to 0.2 mmHg.
The deglycol reaction was performed for a time. 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) was 339 kg excluding condensed water.

5.42 kg of hexamethylene diisocyanate was added to a reactor containing 339 kg of polyester (A1), and a coupling reaction was carried out at 180 to 200 ° 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 HFIPA5mm
ol solution, concentration 0.1% by weight, calibration curve is Showa Denko KK
PMMA standard sample Shodex Standard
d Performed on M-75.

Using the polyester (B1), a biaxially stretched hollow molded container was produced under the following conditions. The average thickness of the product is 0. 0 by an injection stretch blow molding machine (screw-φ50mm).
A cylindrical container having a size of 5 mm and a capacity of 500 ml was formed. The temperature of the bottomed parison resin is 90 ° C., 100 ° C., 110 ° C., the stretching ratio is 2.5 times vertically and horizontally, the product mold temperature is 20 ° C., the blow pressure is 25 kg / cm ² , and the cooling time is 8 seconds. Was.

Bottomed parison resin temperature 90 ° C., 100 ° C.,
The stretchability at 110 ° C. was good, and the thickness of the molded product was also good. Further, the obtained biaxially stretched hollow molded container was filled with 100% of water, and the atmosphere temperature was 5 ° C., and 1.2 m
, But did not break even after repeated 10 drops, and was practically satisfactorily usable. When a tensile test was performed on the product, the breaking strength was 320 kg / cm ² or more,
The elongation was 300% or more. The transparency (haze value) of the product was 25% or less. When the product was buried in soil for 5 months, biodegradability was recognized to the extent that water could not be filled.

Example 2 A 700 L reactor was purged with nitrogen, and 177 kg of 1,4-butanediol, 198 kg of succinic acid and 25 kg of adipic acid were charged. 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.

To a reactor containing 333 kg of polyester (A2), 4.66 kg of hexamethylene diisocyanate was added, and a coupling reaction was carried out at 180 to 200 ° 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.

Example 1 using polyester (B2)
A hollow molded container was manufactured under the same conditions as described above. The stretchability at a bottomed parison resin temperature of 85 ° C., 95 ° C., and 103 ° C. was good, and the thickness of the molded product was also good. The results of the repeated drop test were also good. 5 obtained products
When it was buried in the soil for months, the same results as in Example 1 were obtained.

Example 3 A reactor of 700 L was purged with nitrogen, and then 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 200 ° 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.

Example 1 using polyester (B3)
Under the same conditions as above, a biaxially stretched hollow molded container was produced. The stretchability at the bottomed parison resin temperature of 75 ° C., 85 ° C., and 96 ° C. was good, and the thickness of the molded product was also good. The results of the repeated drop test were also good. As a result of the tensile test of the product, the breaking strength was as good as 320 kg / cm ² or more and the elongation was 300% or more. The transparency (haze value) of the product was 25% or less. When the obtained product was buried in the soil for 5 months, the product was decomposed and changed to a state where the shape of the container was lost.

Example 4 After purging a 700 L reactor with nitrogen, 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). This polyester (A4) is theoretically condensed water 7
Excluding 6 kg, the yield was 367 kg.

3.67 kg of hexamethylene diisocyanate was added to a reactor containing 367 kg of polyester (A4), and a coupling reaction was carried out 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), MFR (190 ° C.) 0.21 / 10 min, temperature 1
The melt viscosity at 80 ° C. and a shear rate of 100 sec ⁻¹ was 2.0 × 10 ⁴ poise. The measurement of the average molecular weight is
Shodex GPC System-11 (Gel chromatography manufactured by Showa Denko KK)), and the solvent is CF ₃ COO
Na HFIPA 2 mmol solution, concentration 0.1% by weight,
The calibration curve is PMMA standard sample Sho made by Showa Denko KK
Performed on dex Standard M-75.

Using the polyester (B4), a biaxially stretched hollow molded container was produced under the following conditions. The average thickness of the product is 0. 0 by an injection stretch blow molding machine (screw-φ50mm).
A cylindrical container having a size of 5 mm and a capacity of 500 ml was formed. The temperature of the bottomed parison resin is 90 ° C., 100 ° C., 110 ° C., the stretching ratio is 2.5 times vertically and horizontally, the product mold temperature is 20 ° C., the blow pressure is 25 kg / cm ² , and the cooling time is 8 seconds. Was.

Bottomed parison resin temperature 90 ° C., 100 ° C.,
The stretchability at 110 ° C. was good, and the thickness of the molded product was also good. Further, the obtained biaxially stretched hollow molded container was filled with 100% of water, and the atmosphere temperature was 5 ° C., and 1.2 m
, But did not break even after repeated 10 drops, and was practically satisfactorily usable. When the product was subjected to a tensile test, the breaking strength was 430 kg / cm ² and the elongation was 360%. Product transparency (haze value) is 25
%Met. When the product was buried in soil for 5 months, biodegradability was recognized to the extent that water could not be filled.

Comparative Example 1 Using the polyester (A1) in Example 1, the temperature of the bottomed parison resin was 80 ° C.
A biaxially stretched hollow molded container was manufactured at 85 ° C., but the bottomed parison was not stretched and could not be molded. Further, a biaxially stretched hollow molded container was produced at a bottomed parison resin temperature of 120 ° C., but the transparency (haze value) was 25%.

[0045]

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 3.0 × 10 ^{3 to} 2.0
× 10 ⁵ poise, and a biaxially stretched hollow molded article made of an aliphatic polyester having a melting point of 70 to 200 ° C.,
A number average molecular weight of 5,000 or more, and a melting point of
A biaxially stretched hollow molded article made of an aliphatic polyester obtained by reacting up to 5 parts by weight of a diisocyanate has biodegradability when buried in soil or the like, and burns even when incinerated. The calorific value is lower than that of polyethylene and polypropylene, and it is excellent in heat stability and mechanical strength, and is useful as various containers such as detergents and cosmetics and industrial products.

──────────────────────────────────────────────────の Continuation of the front page (51) Int.Cl. ⁶ Identification symbol FI C08J 5/00 CFD C08J 5/00 CFD // B29K 67:00 B29L 22:00 (56) References JP-A-6-248061 ( JP, A) JP-A-4-93315 (JP, A) JP-A-6-248516 (JP, A) JP-A-7-47598 (JP, A) JP-A-7-47599 (JP, A)

Claims (4)

(57) [Claims] 1. A temperature of 190 ° C. and a shear rate of 100 sec ⁻¹
Is a biaxially stretched hollow molded article made of an aliphatic polyester having a melt viscosity of 3.0 × 10 ^{3 to} 2.0 × 10 ⁵ poise and a melting point of 70 to 190 ° C. 2. An aliphatic polyester having a number average molecular weight of 1
2. The biaxially stretched hollow molded article according to claim 1, which has a urethane bond content of 3,000 or more and 0.03 to 3.0% by weight. 3. 3. A fat obtained by reacting 0.1 to 5 parts by weight of a 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 biaxially stretched hollow molded article according to claim 1 or 2, wherein the molded article is made of an aromatic polyester. 4. A tensile breaking strength of at least 320 kg / cm ² , a breaking elongation of at least 300%, and a rigidity of 3000 kg / c.
m ² or more and biaxially oriented blow molded product according to claims 1 to 3 values of notched Izod impact strength is 1.0kg · cm / cm ² or more at 23 ° C. as measured by a press.