JPH0716913A - Polyester made biaxially oriented hollow molded item - Google Patents

Abstract

PURPOSE:To provide a biaxially oriented hollow molded item which has biodegradability when buried in soil or the like, is excellent in thermal stability and mechanical strength, and useful as various vessels for detergent, cosmetics, etc., and industrial products. CONSTITUTION:A biaxially oriented hollow molded item is composed of aliphatic polyester which is 3.0X10<3> to 2.0X10<5> poise in melt viscosity at 190 deg.C temperature and 100sec<-1> shear rate, and 70 to 190 deg.C in melting point. The biaxially oriented hollow molded item which has biodegradability and is excellent in thermal stability and mechanical strength is obtained thereby.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a biaxial product which is excellent in thermal stability and mechanical strength, and which is made of an aliphatic polyester having biodegradability and having a practically sufficient high molecular weight and specific melting characteristics. It relates to a stretched hollow molded article.

[0002]

2. Description of the Related Art In recent years, plastics have been made into hollow molding containers from the viewpoints of productivity, versatility, fashionability, chemical resistance, and rust resistance, whether for industrial or domestic use, while using a large amount of these. The plastic waste that has been
It has the potential to pollute the ocean and soil, and has become a major social problem. To prevent this pollution, the emergence of biodegradable plastics has long been awaited. 3-Hydroxybutyrate) and a blend of starch, which is a blend-type natural polymer, and general-purpose plastics are known. However, the former has a drawback that the raw material unit is very bad because the thermal decomposition temperature of the polymer is close to the melting point, the moldability is poor, and microorganisms produce it. In the latter case, since the natural polymer itself is not thermoplastic, it is difficult to mold and the usage range is greatly restricted. On the other hand, it has been known that aliphatic polyester has biodegradability, but it has hardly been used because a high-molecular-weight substance sufficient to obtain practical physical properties of molded articles cannot be obtained. Recently, ε-caprolactone was found to have a high molecular weight by ring-opening polymerization and has been proposed as a biodegradable resin, but its melting point is as low as 62 ° C. and the raw material is expensive, so it is limited to special applications. ing. Glycolic acid and lactic acid have high molecular weights obtained by ring-opening polymerization of glycolide and lactide, and are used in medical fibers, etc., but have melting points and decomposition temperatures close to each other, and have drawbacks in moldability and plasticity. It has not been used in large quantities in biaxially stretched hollow containers.

The high-molecular-weight polyesters (high-molecular-weight polyesters referred to here means those having a number-average molecular weight of 10,000 or more) which are usually used for molding these industrially or domestically used biaxially stretched hollow molded articles, 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
-Although there are examples of using naphthalenedicarboxylic acid, none of them has reported any attempt to impart biodegradability. Therefore, it can be said that there is no idea that a biaxially stretched hollow molded article is molded and put into practical use by using a biodegradable aliphatic polyester in which an aliphatic type is used as a dicarboxylic acid. One of the reasons why this idea of practical application has not been born is that the plastic biaxially stretched hollow molded article is crystalline even though special molding conditions and physical properties of the molded article are required. However, the melting point of the aliphatic polyester is 100.
Most of them are not more than ℃ and have poor thermal stability upon melting, and more importantly, the properties of this aliphatic polyester, especially the mechanical properties represented by tensile strength, are Even if the number average molecular weight is at the same level as the above, the value is remarkably inferior, and it is considered that it was difficult to conceive the idea of obtaining a molded product requiring strength and the like. One of the reasons for this is that the research that expects to improve the physical properties by further increasing the number average molecular weight of the aliphatic polyester has not progressed sufficiently due to its poor thermal stability.

[0004]

DISCLOSURE OF THE INVENTION The present invention uses these aliphatic polyesters as its 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 article that is biodegradable as one of waste disposal means, that is, can be decomposed by microorganisms and the like, and that can be easily disposed of after use.

[0005]

Means for Solving the Problems As a result of various studies on the reaction conditions for obtaining a polyester having a high molecular weight and a moldability of a biaxially stretched hollow molded article having a sufficient practicability, While maintaining the degradability, a specific aliphatic polyester having a practically sufficient high molecular weight is obtained, and the biaxially stretched hollow molded article molded from this has not only the biodegradability but also the thermal stability and the mechanical strength. It was found that the invention was excellent, and the present invention was completed.

That is, the gist of the present invention is (A) a temperature of 190
Melt viscosity at a shear rate of 100 sec ^{−1 at} 3.0 ° C.
× 10 ^{3 to} 2.0 × 10 ⁵ poise and a melting point of 70 to
Biaxially stretched hollow molded article made of aliphatic polyester at 190 ° C., (B) aliphatic polyester having a number average molecular weight of 1
A biaxially stretched hollow molded article of (A) containing 30,000 or more and 0.03 to 3.0% by weight of a urethane bond, (C) having a number average molecular weight of 5,000 or more and a melting point of 60 ° C. or more. 100 parts by weight of the aliphatic polyester prepolymer, 0.1 to
(A) or (B) biaxially stretched hollow molded article obtained by using an aliphatic polyester obtained by reacting 5 parts by weight of diisocyanate, (D) 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 press 23
Notched Izod impact strength at 1.0 ° C is 1.0 kg
· Cm / cm ² or more (A), (B) or (C)
In the biaxially stretched hollow molded article. Hereinafter, the content of the present invention will be described in detail.

The term "aliphatic polyester" as used in the present invention means two components of glycols and dicarboxylic acid (or acid anhydride thereof), or, if necessary, a trifunctional or tetrafunctional polyfunctional compound as a third component. The main component is a polyester obtained by reacting with at least one polyfunctional component selected from a polyhydric alcohol, an oxycarboxylic acid and a polyvalent carboxylic acid (or an acid anhydride thereof), and the end of the molecule. A relatively high-molecular-weight polyester prepolymer having a hydroxyl group in is prepared, and this is further polymerized with a coupling agent.

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

As in the case of polyurethane rubber, a method of adding a diisocyanate to convert a hydroxyl group into an isocyanate group and further increasing the number average molecular weight with glycol can be considered. As described above, in order to obtain practical physical properties, the amount is 10 parts by weight or more based on 100 parts by weight of the prepolymer, and there is the same problem as above. If a relatively high molecular weight polyester prepolymer is used, the heavy metal-based catalyst necessary for the synthesis of the prepolymer remarkably promotes the reactivity of the above-mentioned amount of the isocyanate group, resulting in poor storage stability, crosslinking reaction, and branching. If the polyester prepolymer synthesized without a catalyst is used, the number average molecular weight is limited to 2,500, 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, it is a saturated aliphatic polyester having a relatively high molecular weight of 10,000 or more and a melting point of 60 ° C. or more, and is obtained by catalytically reacting a glycol with a dicarboxylic acid (or an acid anhydride thereof). . Number average molecular weight is 5,
If it is less than 000, for example, about 2,500, a polyester for a biaxially stretched hollow molded article having good physical properties cannot be obtained with a small amount of a coupling agent of 0.1 to 5 parts by weight used in the present invention. . Number average molecular weight is 5,000
A polyester prepolymer having a value of 0 or more has a hydroxyl value of 30 or less, and a small amount of a coupling agent is used, so that even under severe conditions such as a molten state, it is not affected by the remaining catalyst, so that a gel is formed during the reaction. Without, high molecular weight polyesters can be synthesized.

Examples of glycols used include aliphatic glycols, especially those having 2 or 4 carbon atoms,
It has an even number of linear alkylene groups of 6, 8 and 10 and includes, for example, ethylene glycol, 1,4-butanediol, 1,6-hexanediol, 1,8-octanediol, 1,10-decanediol, And mixtures thereof are preferred. Among these, those having a small number of carbon atoms, such as ethylene glycol, 1,4-butanediol, and 1,6-hexanediol, are preferable because they can synthesize an aliphatic polyester having high crystallinity and high melting point. In particular, ethylene glycol and 1,4-butanediol are most suitable because they give good results.

Aliphatic dicarboxylic acids or their acid anhydrides are used to form aliphatic polyesters by reacting with glycols, and especially those having 2, 4, 6, 8 carbon atoms.
And those having an even number of linear alkylene groups of 10, such as succinic acid, adipic acid, suberic acid, sebacic acid, 1,
10-decanedicarboxylic acid, succinic anhydride, and mixtures thereof are preferred. Among these, those having a small number of carbon atoms, for example, succinic acid, adipic acid, and succinic anhydride are more preferable because they can synthesize polyethylene with high crystallinity and high melting point. In particular succinic acid or succinic anhydride, and these and other dicarboxylic acids such as adipic acid, suberic acid,
Most preferred are mixed acids with sebacic acid and 1,10-decanedicarboxylic acid. When a mixed acid is used, a suitable mixing ratio of two or more components consisting of, for example, succinic acid and another dicarboxylic acid is usually 7 for succinic acid.
Most preferably, it is 0 mol% or more, preferably 90 mol% or more, and the dicarboxylic acid other than succinic acid is 30 mol% or less, preferably 10 mol% or less. In particular, a combination of 1,4-butanediol and succinic acid or an acid anhydride thereof, and a combination of ethylene glycol and succinic acid or an acid anhydride thereof have melting points similar to those of polyethylene, and the most preferable combination for the present invention. Can be said.

(Third component) In addition to these glycols and dicarboxylic acid, a trifunctional or tetrafunctional polyhydric alcohol, oxycarboxylic acid and polycarboxylic acid (as a third component) may be added, if necessary. Or its acid anhydride)
At least one polyfunctional component selected from the above may be added and reacted. Addition of this third component causes branching of the long chain in the molecule, increasing the molecular weight and increasing the Mw.
/ Mn becomes large, that is, the molecular weight distribution becomes wide,
Desired properties can be imparted to film forming and the like. The amount of the polyfunctional component added is, in order to eliminate the risk of gelation, in the case of trifunctional with respect to 100 mol% of the total components of the aliphatic dicarboxylic acid (or its acid anhydride), it is 0. 1 to 5 mol%, and 0.1 to 4 in the case of tetrafunctionality
It is 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. Typical examples of the trifunctional polyhydric alcohol component are trimethylolpropane, glycerin and their anhydrides, and typical examples of the tetrafunctional polyhydric alcohol component are pentaerythritol.

The trifunctional oxycarboxylic acid component is (i)
There are two types of carboxyl groups and one hydroxyl group in the same molecule, and (ii) one carboxyl group and two hydroxyl groups in the same molecule, but commercial products are easy and low cost. In terms of availability at
Malic acid of (i), which shares two carboxyl groups and one hydroxyl group in the same molecule, 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 in which three carboxyl groups and one hydroxyl group are shared in the same molecule, (ii) A type in which two carboxyl groups and two hydroxyl groups are shared in the same molecule, (iii) Three There is a type that shares a hydroxyl group of 1 and a carboxyl group in the same molecule, and both types can be used, but from the viewpoint that commercial products are easily available at low cost, citric acid In addition, tartaric acid is practically advantageous and sufficient for the purpose of the present invention. As the trifunctional polyvalent carboxylic acid (or its acid anhydride) component, for example, trimesic acid, propanetricarboxylic acid, etc. can be used, but trimellitic anhydride is advantageous from the practical viewpoint, and for the purpose of the present invention. Is enough. There are various types of tetrafunctional polycarboxylic acid (or acid anhydride thereof) such as aliphatic, cycloaliphatic, and aromatic in the literature. Pyromellitic dianhydride, benzophenone tetracarboxylic acid anhydride and cyclopentane tetracarboxylic acid anhydride are mentioned, which are sufficient for the purpose of the present invention.

These glycols and polybasic acids are mainly of an aliphatic type, but a small amount of other components such as an aromatic type may be used together. However, if other components are introduced, biodegradability deteriorates, so the content is 20% by weight or less, preferably 10% by weight or less, and more preferably 5% by weight or less. The polyester prepolymer for the aliphatic polyester used in the present invention has a terminal group substantially a hydroxyl group,
For this purpose, the glycols and polybasic acid (or its acid anhydride) used in the synthesis reaction must be used in a somewhat excess amount.

The synthesis of relatively high molecular weight polyester prepolymers requires the use of a deglycolization catalyst during the deglycolization reaction following esterification. Examples of the deglycolization reaction catalyst include titanium compounds such as acetoacetoyl type titanium chelate compounds and organic alkoxy titanium compounds. These titanium compounds can be used in combination. Examples of these include diacetoacetoxyoxytitanium (“Narsem titanium” manufactured by Nippon Kagaku Sangyo Co., Ltd.), tetraethoxytitanium, tetrapropoxytitanium, tetrabutoxytitanium and the like. The titanium compound is used in an amount of 0.001 to 100 parts by weight of the polyester prepolymer.
It is 1 part by weight, preferably 0.01 to 0.1 part by weight.
The titanium compound may be added from the beginning of esterification or immediately before the deglycolization reaction.

Further, the number average molecular weight is 5,000 or more,
Coupling agents are preferably used to increase the number average molecular weight of polyester prepolymers having 10,000 or more end-groups which are substantially hydroxyl groups. Examples of the coupling agent include diisocyanate, oxazoline, diepoxy compound, acid anhydride, and the like.
Diisocyanate is particularly preferable. In the case of an oxazoline or diepoxy compound, it is necessary to react the hydroxyl group with an acid anhydride or the like to convert the terminal into a carboxyl group before using the coupling agent. The type of diisocyanate is not particularly limited, but 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 preferable from the viewpoint of the hue of the produced resin, the reactivity at the time of adding polyester, and the like.

The amount of these coupling agents 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 it is less than 0.1 part by weight, the coupling reaction is insufficient, and if it exceeds 5 parts by weight, gelation tends to occur.

It is desirable that the addition is carried out under the condition that the polyester prepolymer is in a uniform molten state and can be easily stirred. It is not impossible to add it to a solid polyester prepolymer and melt and mix it through an extruder, but add it to an aliphatic polyester production apparatus or to a molten polyester prepolymer (for example, in a kneader). It is practical to do so.

The aliphatic polyester used in the present invention is required to have specific melting characteristics in order to carry out biaxially stretched hollow molding. That is, the temperature is 190 ° C, the shear rate is 100 se
The melt viscosity at c ⁻¹ is 3.0 × 10 ^{3 to} 2.0 × 10.
⁵ poise, preferably 7.0 × 10 ^{3 to} 3.0 ×
Particularly preferred are 10 ⁴ poise and 1.2 × 10 ^{4 to} 2.3 × 10 ⁴ poise. 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 is required 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 the deformation during use becomes a problem.
If the temperature exceeds 0 ° C, it is difficult to manufacture. To obtain a melting point of 70 ° C or higher, the polyester prepolymer has a melting point of 60.
It is necessary to be ℃ 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, and 0.1. 1 to 1.0% by weight is particularly preferred.
The amount of urethane bond 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 moldability is poor,
If it exceeds 3.0% by weight, gel is generated.

When the above aliphatic polyester is used to obtain the biaxially stretched hollow molded article according to the present invention, other lubricants such as antioxidants, heat stabilizers and ultraviolet absorbers, waxes, etc. may be used, if necessary. It is needless to say that a colorant (each method such as colored pellet, dry color, master-batch), a foaming agent, a crystallization accelerator, a reinforcing fiber and the like can be used in combination. That is, as antioxidants, hindered phenolic antioxidants such as pt-butylhydroxytoluene and pt-butylhydroxyanisole, sulfur-based antioxidants such as distearylthiodipropionate and dilaurylthiodipropionate. Examples of heat stabilizers such as agents include triphenyl phosphite, trilauryl phosphite, and trisnonyl phenyl phosphite, and examples of ultraviolet absorbers include pt
-Butylphenyl salicylate, 2-hydroxy-4-
Methoxybenzophenone, 2-hydroxy-4-methoxy-2'-carboxybenzophenone, 2,4,5-trihydroxybutyrophenone, etc., lubricants, calcium stearate, zinc stearate, barium stearate, sodium palmitate, etc., antistatic As the agent, N, N-bis (hydroxyethyl) alkylamine, alkylamine, alkylallyl sulfonate, alkyl sulfonate, etc., as the flame retardant, hexabromocyclododecane, tris- (2,3-dichloropropyl) phosphate, Inorganic fillers such as pentabromophenyl allyl ether include calcium carbonate, silica,
Titanium oxide, talc, mica, barium sulfate, alumina, etc., crystallization accelerators such as polyethylene terephthalate, poly-transcyclohexanedimethanol terephthalate, etc., reinforcing fibers such as glass fibers, carbon fibers,
Examples thereof include inorganic fibers such as boron fibers, silicon carbide fibers, graphite fibers, alumina fibers and amorphous fibers, and organic fibers such as aramid fibers.

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

[0026]

EXAMPLES The present invention will be described below with reference to examples and comparative examples. (Example 1) After replacing a 700 L reactor with nitrogen,
1,4-butanediol 183 kg, succinic acid 224 k
I charged g. The temperature is raised under a nitrogen stream, and 192-22
3.5 hours at 0 ° C, 20 to 2 mm after stopping nitrogen further
The esterification reaction by dehydration condensation was carried out under a reduced pressure of Hg for 3.5 hours. The sample collected has an acid value of 9.
It was 2 mg / g, 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 under normal pressure. Raise the temperature to 215
5.5 at -220 ° C. under reduced pressure of 15-0.2 mmHg
The deglycol reaction was performed for a period of time. The sample collected 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 when condensed water was removed.

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 gelation occurred. Next, Irganox 1010 as an antioxidant
(Manufactured by Ciba Geigy) and 1.70 kg of calcium stearate as a lubricant were added, and stirring was continued for another 30 minutes. This reaction product was extruded into water with an extruder and cut into pellets with a cutter. After vacuum drying at 90 ° C. for 6 hours, the yield of polyester (B1) was 300 kg.

The obtained polyester (B1) is a slightly ivory white waxy crystal and has 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 minutes, the viscosity of a 10% solution of orthochlorophenol is 230 poises, Temperature 190 ℃, 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 gel chromatography), solvent is CF ₃ COONa HFIPA 5 mm
ol solution, concentration 0.1% by weight, calibration curve is Showa Denko KK
Made PMMA standard sample Shodex Standard
dM-75.

Using the polyester (B1), a biaxially stretched hollow molded container was produced under the following conditions. Using an injection stretch blow molding machine (screw-φ50 mm), the product has an average wall thickness of 0.
A cylindrical container of 5 mm and a capacity of 500 ml was molded. The bottomed parison resin temperature is 90 ° C, 100 ° C, 110 ° C, the draw ratio is 2.5 times in the longitudinal and transverse directions, the product mold temperature is 20 ° C, the blow pressure is 25 kg / cm ² , and the cooling time is 8 sec. It 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. In addition, the obtained biaxially stretched hollow molding container was filled with 100% of water, and the atmosphere temperature was 5 ° C.
Although it was dropped from the height, it did not break even after being repeatedly dropped 10 times, and was practically sufficiently usable. When the product was subjected to a tensile test, 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 it could not be filled with water.

Example 2 A 700 L reactor was purged with nitrogen, and then 177 kg of 1,4-butanediol, 198 kg of succinic acid, and 25 kg of adipic acid were charged. The temperature is raised under a nitrogen stream and the temperature is set at 190 to 210 ° C for 3.5 hours.
Further, nitrogen is stopped, and under reduced pressure of 20 to 2 mmHg, 3.
The esterification reaction by dehydration condensation was performed for 5 hours. The sample collected 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 tetraisopropoxy titanium as a catalyst was added under a nitrogen stream under normal pressure. Raise the temperature to 15-
The deglycol reaction was performed for 6.5 hours under a reduced pressure of 0.2 mmHg. The collected sample has a number average molecular weight (Mn)
Is 17,300, and the weight average molecular weight (Mw) is 46,
It was 400. The yield of this polyester (A2) was 337 kg when condensed water was removed.

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 200 ° C. for 1 hour. The viscosity increased rapidly but no gelation occurred. Next, Irganox 1010 as an antioxidant
(Manufactured by Ciba Geigy) and 1.70 kg of calcium stearate as a lubricant were added, and stirring was continued for another 30 minutes. This reaction product was extruded into water with an extruder and cut into pellets with a cutter. After vacuum drying at 90 ° C. for 6 hours, the yield of polyester (B2) was 300 kg.

The polyester (B2) thus obtained was a slightly ivory white waxy crystal and had 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 minutes, 10% of orthochlorophenol.
Viscosity of the solution is 680 poise, temperature 190 ℃, shear rate 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 the bottomed parison resin temperatures of 85 ° C, 95 ° C, and 103 ° C was good, and the thickness of the molded product was also good. The result of the repeated drop test was also good. 5 products obtained
When it was buried in soil for a month, the same results as in Example 1 were obtained.

(Example 3) After replacing a 700 L reactor with nitrogen, 145 kg of ethylene glycol and 2 parts of succinic acid were used.
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 carried out at 190 to 210 ° C. for 3.5 hours, and further, nitrogen was stopped and the pressure was reduced at 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 tetraisopropoxy titanium as a catalyst was added under a nitrogen stream under normal pressure.
Raise the temperature to 15-0.2 at a temperature of 210-220 ° C.
The deglycol reaction was performed for 4.5 hours under reduced pressure of mmHg. The sample collected has a number average molecular weight (Mn) of 3
3,400, and the weight average molecular weight (Mw) is 137,0
It was 00. The yield of this polyester (A3) was 323 kg when condensed water was removed.

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 gelation occurred. Next, Irganox 1010 as an antioxidant
1.62 kg (manufactured by Ciba Geigy) and 1.62 kg calcium stearate as a lubricant were added, and stirring was continued for another 30 minutes. This reaction product was extruded into water with an extruder and cut into pellets with a cutter. The yield of polyester (B3) after vacuum drying at 90 ° C. for 6 hours was 300 kg.

The resulting polyester (B3) was a slightly ivory-like white waxy 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 minutes, viscosity of 10% solution of orthochlorophenol is 96 poise, temperature 190 ° C., shear rate 100 se
The melt viscosity at c ⁻¹ was 1.6 × 10 ⁴ poise.

Example 1 using polyester (B3)
A biaxially stretched hollow molded container was manufactured under the same conditions as described above. 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 result of the repeated drop test was also good. As a result of the tensile test of the product, the breaking strength was 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, it was decomposed and changed into a state where the shape of the container was broken.

(Example 4) After replacing a 700 L reactor with nitrogen, 200 kg of 1,4-butanediol, 250 kg of succinic acid and 2.8 kg of trimethylolpropane.
Was charged. The temperature is raised under a nitrogen stream, and the temperature is 192-220.
4.5 hours at ℃, 20 to 2mmH after stopping nitrogen further
The esterification reaction by dehydration condensation was performed for 5.5 hours under a reduced pressure of g. The sample collected has an acid value of 10.
It was 4 mg / g, 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 under normal pressure. Increase the temperature to 210
8.0 at 220 ° C. under a reduced pressure of 15 to 1.0 mmHg.
The deglycol reaction was performed for a period of time. The sample collected 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
The yield was 367 kg excluding 6 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 gelation occurred. Next, Irganox 1010 as an antioxidant
367 g (manufactured by Ciba Geigy) and 367 g of calcium stearate as a lubricant were added, and stirring was continued for another 30 minutes. This reaction product was extruded into water with an extruder and cut into pellets with a cutter. 9
Polyester (B4) after vacuum drying at 0 ° C for 6 hours
The yield was 350 kg.

The polyester (B4) obtained was a slightly ivory-like white waxy 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) is 0.21 / 10 minutes, temperature is 1
The melt viscosity at 80 ° C. and a shear rate of 100 sec ⁻¹ was 2.0 × 10 ⁴ poise. The average molecular weight can be measured by
Shodex GPC System-11 (Showa Denko KK gel chromatography)), the solvent is CF ₃ COO
HFIPA 2 mmol solution of Na, concentration 0.1% by weight,
The calibration curve is Showa Denko KK's PMMA standard sample Sho
Performed on dex Standard M-75.

Using the polyester (B4), a biaxially stretched hollow molded container was produced under the following conditions. Using an injection stretch blow molding machine (screw-φ50 mm), the product has an average wall thickness of 0.
A cylindrical container of 5 mm and a capacity of 500 ml was molded. The bottomed parison resin temperature is 90 ° C, 100 ° C, 110 ° C, the draw ratio is 2.5 times in the longitudinal and transverse directions, the product mold temperature is 20 ° C, the blow pressure is 25 kg / cm ² , and the cooling time is 8 sec. It 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. In addition, the obtained biaxially stretched hollow molding container was filled with 100% of water, and the atmosphere temperature was 5 ° C.
Although it was dropped from the height, it did not break even after being repeatedly dropped 10 times, and was practically sufficiently 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 it could not be filled with water.

Comparative Example 1 The polyester (A1) used in Example 1 was used, 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, the temperature is 190 ° C. and the shear rate is 10
Melt viscosity at ⁰ sec ⁻¹ is 3.0 × 10 ^{3 to} 2.0
A biaxially stretched hollow molded article composed of an aliphatic polyester having a melting point of 70 to 200 ° C. and having a porosity of 10 ⁵ poises, particularly,
Add 100 parts by weight of aliphatic polyester prepolymer having a number average molecular weight of 5,000 or more and a melting point of 60 ° C. or more to 0.1.
A biaxially stretched hollow molded article obtained by reacting ~ 5 parts by weight of diisocyanate with an aliphatic polyester has biodegradability when buried in soil or the like, and burns even when incinerated. The calorific value is lower than that of polyethylene or polypropylene, and it has excellent thermal stability and mechanical strength, and is useful as various containers such as detergents and cosmetics, and industrial products.

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Eiichiro Takiyama 4-12-4 Nishi-Kamakura, Kamakura City, Kanagawa Prefecture

Claims (4)

[Claims] 1. A temperature of 190 ° C. and a shear rate of 100 sec ^−1.
A biaxially stretched hollow molded article composed of an aliphatic polyester having a melt viscosity of 3.0 × 10 ^{3 to} 2.0 × 10 ⁵ poises and a melting point of 70 to 190 ° C. 2. The aliphatic polyester has a number average molecular weight of 1.
The biaxially stretched hollow molded article according to claim 1, which has a urethane bond content of 30,000 or more and 0.03 to 3.0% by weight. 3. A fat obtained by reacting 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 with 0.1 to 5 parts by weight of diisocyanate. The biaxially stretched hollow molded article according to claim 1 or 2, which comprises a group III polyester. 4. Tensile breaking strength is 320 kg / cm ² or more, breaking elongation is 300% or more, and rigidity is 3000 kg / c.
The biaxially stretched hollow molded article according to claim 1, which has a notched Izod impact strength of 1.0 kg · cm / cm ² or more at m ² or more and at 23 ° C. measured by a press.