JP2759596B2 - Polyester film - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION
The present invention relates to an aliphatic polyester film formed from an aliphatic polyester having a practically sufficient high molecular weight having a number average molecular weight of 20,000 or more and having excellent thermal stability and mechanical strength.

[0002]

2. Description of the Related Art High-molecular-weight polyesters (hereinafter, referred to as "polyesters") conventionally used for molding films, fibers, and other molded articles.
The term "high molecular weight polyester" as used herein means a number average molecular weight of 20,000 or more. ) Was limited to polyethylene terephthalate, which is a condensate of terephthalic acid (including dimethyl terephthalate) and ethylene glycol, or butylene terephthalate from terephthalic acid and butylene glycol.

[0003] However, these films have high rigidity and high strength as ordinary blown film or cast film due to the molecular structural factor of terephthalic acid, but remain unstretched. Then, it was brittle and had no value as a film, and was widely used as a stretched film. Although the stretched polyester film is extremely excellent in transparency, strength, etc., it has a problem in heat sealing properties, so it was bonded to a polyolefin resin or film excellent in heat sealing properties as a heat sealing packaging film. It could only be used as a laminate.

For this improvement, instead of terephthalic acid,
Although there is an example using 2,6-naphthalenedicarboxylic acid,
There is no practical example of forming a polyester, using an aliphatic dicarboxylic acid as a dicarboxylic acid, into a sheet, a film, a fiber or the like and putting it into practical use.

[0005] One of the reasons why it has not been put to practical use is that even if it is crystalline, the melting point of aliphatic polyester is almost 100 ° C. or less, and furthermore, the thermal stability upon melting is poor. More importantly, the properties of the aliphatic polyester, particularly the mechanical properties represented by tensile strength, are extremely low, and even at the same level of the number average molecular weight as polyethylene terephthalate, it shows only a remarkably inferior value. There is no other way than it was.

[0006] In the research for improving the physical properties by further increasing the number average molecular weight of the aliphatic polyester, it seems that the thermal stability has not been sufficiently developed from the place where the thermal stability is poor.

Further, since aromatic polyesters such as polyethylene terephthalate do not have microbial decomposability, they are not decomposed forever by simply discarding after use, and require incineration for complete treatment. Had.

Particularly in the field of packaging, there is a strong demand for the development of a film which has not only requirements such as strength but also has high transparency, can be heat-sealed, is easy to dispose of, and has microbial decomposability and low combustion heat generation. Had been requested.

[0009]

The first object of the present invention is to dispose of a polymer having a practically sufficient high molecular weight, excellent mechanical properties such as thermal stability and tensile strength, and being discarded after use. Another object of the present invention is to provide an aliphatic polyester air-cooled inflation film which has a small heat generation value for combustion, can be easily decomposed by microorganisms and the like, is easily disposed of, and has heat sealing properties as it is.

The second is that it is transparent, has a practically sufficient high molecular weight, has excellent mechanical properties such as thermal stability and tensile strength, and generates heat even when discarded after use. It is an object of the present invention to provide an aliphatic polyester water-cooled blown film which is small in quantity, can be easily decomposed by microorganisms and the like, is easily disposed of, and has heat sealability as it is.

The third one is transparent, has a practically sufficient high molecular weight, is excellent in mechanical properties represented by thermal stability and tensile strength, and generates heat even when discarded after use. It is an object of the present invention to provide an aliphatic polyester T-die flat film which is small in quantity, can be easily decomposed by microorganisms and the like, is easily discarded, and has heat sealability as it is.

[0012]

The present invention relates to (1) an aliphatic polyester prepolymer mainly synthesized from glycol and an aliphatic dibasic acid or a derivative thereof (excluding a hydroxyl group-containing dibasic acid). Temperature 190 obtained by reacting a coupling agent with
The melt viscosity at 100 ° C. and a shear rate of 100 (sec ⁻¹ ) is 2,000 to 100,000 poise, and the melting point is 70.
A polyester film having a thickness of 10 to 150 μm molded from an aliphatic polyester having a temperature of 200 to 200 ° C .; (2) the aliphatic polyester according to the above (1), which is mainly synthesized from glycol and an aliphatic dibasic acid or a derivative thereof. At a molding temperature of 120 to 240 ° C., blow-up O.D. The molded thickness in the range of 5 to 6.0 is 10
(3) Tensile breaking strength (MD) is 300 kg / cm ² or more, breaking elongation is 200% or more, and film Young's modulus is 2,
(1) or (2) above which is 000 kg / cm ² or more.
(4) The aliphatic polyester according to (1), which is mainly synthesized from glycol and an aliphatic dibasic acid or a derivative thereof, at a molding temperature of 120 to 240 ° C and a blow-up ratio of 1.0 to In the range of 4.0, the molded thickness is 10
(1) Haze 8% or less, tensile strength at break (MD) of 15
0 kg / cm ² or more, elongation at break of 400% or more, and film Young's modulus of 600 kg / cm ² or more.
Or (4) the highly transparent water-cooled blown film according to (4), (6) the aliphatic polyester according to (1), which is mainly synthesized from glycol and an aliphatic dibasic acid or a derivative thereof, at a molding temperature of 120 to 240 ° C. A T-die flat film having a thickness of 10 to 150 μm, characterized in that: (7) a tensile strength at break (MD) of 150 kg / cm ² or more, a breaking elongation of 200% or more, and a film Young's modulus Is 60
The T-die flat film according to the above (1) or (6), which is 0 kg / cm ² or more; and (8) the aliphatic polyester has a number average molecular weight of 20,000.
The above object was achieved by developing the polyester film according to any one of the above (1) to (7), which has an MFR (190 ° C.) of 20 g / 10 minutes or less.

The aliphatic polyester referred to in the present invention is mainly composed of a polyester synthesized mainly from glycols and an aliphatic dibasic acid or an acid anhydride thereof. In order to increase the molecular weight sufficiently, This is obtained by synthesizing a relatively high molecular weight polyester prepolymer having a hydroxyl group at a terminal, and then coupling these prepolymers with a coupling agent.

Conventionally, a low molecular weight polyester prepolymer having a hydroxyl group at the terminal group and having a number average molecular weight of 2,000 to 2,500 is reacted with diisocyanate to form polyurethane, rubber, foam, paint, adhesive It is widely used as an agent.

However, the polyester prepolymer used for these polyurethane-based foams, paints and adhesives is a low molecular weight prepolymer having a number average molecular weight of 2,000 to 2,500.
In order to obtain practical physical properties as a polyurethane with respect to 00 parts by weight, the amount of diisocyanate used should be 10 to
It must be 20 parts by weight. However, if such a large amount of diisocyanate is added to a low-molecular-weight polyester melted at 150 ° C. or higher, gelation occurs, and a melt-moldable resin cannot be obtained.

Also, 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, but the amount of the diisocyanate used may be reduced as described above. 10 parts by weight or more is required per part by weight. At this time, if a heavy metal-based catalyst is used for the synthesis of the polyester, the reactivity of the isocyanate group is remarkably promoted, resulting in poor storage stability, crosslinking reaction, and branch formation, so that the polyester prepolymer is synthesized without a catalyst. As a result, the number average molecular weight is limited to about 2,500 at the highest.

The polyester prepolymer for obtaining the aliphatic polyester used in the present invention has a terminal group obtained by reacting mainly a glycol with an aliphatic dibasic acid or an anhydride thereof, substantially having a hydroxyl group. The number average molecular weight is 5,000 or more, preferably 10,
A saturated aliphatic polyester having a relatively high molecular weight of 000 or more and a melting point of 60 ° C. or more.

When the number average molecular weight is less than 5,000,
Even with a small amount of the coupling agent of 0.1 to 5 parts by weight, a polyester having good physical properties cannot be obtained. Polyester prepolymers having a number average molecular weight of 5,000 or more have a hydroxyl value of 30 or less, and use of a small amount of a coupling agent does not cause gelation during the reaction even under severe conditions such as a molten state. Polyester can be synthesized.

As the glycols used, 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.

The aliphatic dibasic acids or derivatives thereof which form aliphatic polyesters by reacting with glycols include succinic acid, adipic acid, suberic acid, sebacic acid,
There are lower alcohol esters such as dodecane diacid, succinic anhydride, adipic anhydride and dimethyl ester thereof, and these are commercially available and can be used in the present invention. A dibasic acid or an acid anhydride thereof may be used in combination.

These glycols and dibasic acids are mainly composed of aliphatic compounds, but a small amount of other components such as trifunctional or tetrafunctional polyhydric alcohols and oxycarboxylic acids (provided that a dibasic acid having a hydroxyl group is used) ) Or a polyvalent carboxylic acid.

The trifunctional polyhydric alcohol component is typically trimethylolpropane, glycerin or its anhydride, and the tetrafunctional polyhydric alcohol component is pentaerythritol.

As the tetrafunctional oxycarboxylic acid component, citric acid is practical because a commercially available product can be easily obtained at low cost.

As the trifunctional polycarboxylic acid (or its acid anhydride) component, for example, trimesic acid, propanetricarboxylic acid, etc. can be used, but trimellitic anhydride is advantageous in practical use.

Examples of the tetrafunctional polycarboxylic acid (or its acid anhydride) include pyromellitic anhydride, benzophenonetetracarboxylic anhydride, cyclopentanetetracarboxylic anhydride and the like.

The proportion of the polyfunctional component used is such that the mole number of either the glycol component or the aliphatic (including cycloaliphatic) dicarboxylic acid (or acid anhydride) component is 100.
In the case of a trifunctional component, it is 5 mol% or less, preferably 0.5 mol% or more and 3 mol% or less, and in the case of a tetrafunctional component, it is 3 mol% or less, preferably 0.2 mol%. Not less than 2 mol%.

When the proportion of the trifunctional component is more than 5 mol%, or when the proportion of the tetrafunctional component is more than 3 mol%, the risk of gelling during the esterification reaction is significantly increased.

The polyester prepolymer for aliphatic polyester used in the present invention has a hydroxyl group at the terminal group. For this purpose, glycols and dibasic acids (or acid anhydrides thereof) used for the synthesis reaction are used. The proportion used requires the use of some excess of glycols.

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 (“Nasem 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.
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.

As a result, the polyester prepolymer usually has an acid average molecular weight of 5,000 or more, preferably 20,000.
A material having a melting point of 0 or more and a melting point of 60 ° C. or more can be easily obtained, and it is more preferable that the material has crystallinity.

In order to obtain the aliphatic polyester of the present invention, the number average molecular weight is preferably 5,000 or more, more preferably 1 or more.
Coupling agents are used to increase the number average molecular weight of polyester prepolymers having at least 000 terminal hydroxyl groups.

Examples of the coupling agent include diisocyanates, oxazolines, diepoxy compounds, acid anhydrides, etc., 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 into a carboxyl group before using a coupling agent.

The diisocyanate is not particularly limited,
For example, 2,4-tolylene diisocyanate, 2,4-
A mixture of tolylene diisocyanate and 2,6-tolylene diisocyanate, diphenylmethane diisocyanate, 1,5-naphthylene diisocyanate, xylylene diisocyanate, hydrogenated xylylene diisocyanate, hexamethylene diisocyanate, Isophorone diisocyanate is preferred, and hexamethylene diisocyanate is particularly preferred from the viewpoints of the hue of the formed resin, reactivity when adding polyester, and the like.

The addition amount of these coupling agents 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.

When the amount is less than 0.1 part by weight, the coupling reaction is insufficient. When the amount exceeds 5 parts by weight, gelation occurs.

The addition is desirably performed under conditions in which the polyester prepolymer is in a uniform molten state and can be easily stirred. It can be added to a solid polyester prepolymer and melted and mixed through an extruder, but it is added to an aliphatic polyester production apparatus or to a molten polyester prepolymer (for example, in a kneader). It is practical.

The aliphatic polyester resin has a temperature of 190.
The melt viscosity at 100 ° C. and a shear rate of 100 (sec ⁻¹ ) is 2,000-100,000 poise, and the MFR (19
0 ° C.) is 20 g / 10 min or less. Particularly preferably, it is 5,000 to 50,000 poise. If it is smaller than 2,000 poise, the bubble becomes extremely unstable in the inflation molding, so that the inflation molding becomes difficult. The flow was remarkably deteriorated, and heat generation and flow unevenness occurred from the die outlet, so that a good quality film could not be obtained. On the other hand, if the MFR (190 ° C.) is more than 20 g / 10 min, bubble stability is poor and workability is reduced.

In the T-die molding method, 2,0
If the poise is smaller than 00 poise, the ears on both sides are remarkably generated and become unstable, making molding difficult.
When the poise exceeds 00 poise, the flow at the time of passing through the die becomes extremely poor, and the amount of resin flowing out from the center portion and both side portions of the T-die greatly differs (both side portions are smaller than the center portion). ), The thickness cannot be uniform, and a good quality film cannot be obtained.

The film has an aliphatic polyester having a number average molecular weight of 20,000 or more and a melting point of 70 to 200 ° C.
Wherein the urethane bond is particularly 0.03-3.
It is desirably 0% by weight. Number average molecular weight is 20,
For the first time, a film having the above-mentioned strength of at least 000 can be obtained, and can be used in various applications. 20,
If it is less than 000, it becomes brittle in terms of strength, which is not preferable as a film having practical strength.

The air-cooled inflation film is obtained by sufficiently melting and mixing the resin in an extruder by an extrusion molding method, and then uniformly extruding the resin from a circular die in a state where the resin temperature is made uniform. By expanding the film to about 0.5 to 6.0, a tubular film having a film thickness of about 10 μm to 150 μm can be obtained. In particular, setting the molding temperature is important, and the temperature of the cylinder and the die of the extruder should be 1
20-240 ° C, preferably 160-190 ° C,
If the temperature is lower than 120 ° C., the viscosity is too high to form a stable film. On the other hand, when the temperature exceeds 240 ° C., the resin is deteriorated, gels and foreign substances are frequently generated, and it becomes difficult to form a high-quality film.

A water-cooled blown film is prepared by sufficiently melting and mixing a resin in an extruder and then uniformly extruding the resin with a circular die in a state where the resin temperature is made uniform. By expanding the film to about 4.0, a tubular film having a film thickness of about 10 μm to 150 μm can be obtained. In particular, setting the molding temperature is important,
Extruder cylinder and die temperatures are 120-240
° C, preferably 160 to 190 ° C. If the temperature is lower than 120 ° C, the viscosity is too high to form a stable film.
On the other hand, if the temperature exceeds 240 ° C., bubbles become unstable, and the resin is deteriorated to cause a large number of gels and foreign substances, which makes it difficult to form a good quality film.

Further, the T-die flat film is obtained by sufficiently melting and mixing an aliphatic polyester resin in an extruder, and extruding from a T-die (lip gap 1.2 mm) while keeping the resin temperature uniform. While cooling with a chill roll, a flat film can be obtained with a film thickness of 10 μm to 150 μm and a take-up speed of 40 to 200 m / min. In particular, setting of the molding temperature is important, and the temperature of the cylinder and the die of the extruder is from 120 ° C to 240 ° C.
° C, preferably 160 to 190 ° C. If the temperature is lower than 120 ° C., the viscosity is too high to form a stable film.
On the other hand, if the temperature exceeds 240 ° C., the resin is deteriorated, and the generation of gels and foreign substances increases, and it becomes difficult to form a high quality film.

The physical properties of the film produced by the air-cooled inflation method were that the tensile strength at break (MD) was 300 kg.
/ Cm ² or more, and the breaking elongation is 200% or more,
The film Young's modulus is 2,000 kg / cm ² or more. Having a breaking strength of 300 kg / cm ² or more is a great feature because it generally has excellent strength as a packaging film and can be used for packaging heavy objects. On the other hand, 300k
If it is less than g / cm ² , the utility value is reduced due to insufficient strength.

The film is characterized in that it has a breaking elongation of 200% or more. The packaging material is not broken even when it has a breaking elongation of 200% or more against projections and various impacts. As a great feature.
If it is less than 200%, it easily breaks due to piercing impact force or the like, which is not preferable.

Further, when the Young's modulus is 2,000 kg / cm ² or more, this film can be used for automatic packaging and bag making.
It is excellent in processing suitability in performing the next processing, and has a moderate stiffness in handling the film by hand and is easy to handle. If it is less than 2,000 kg / cm ^2, it is not preferable in terms of suitability for secondary processing and ease of handling.

The properties of the film produced by the water-cooled inflation method are as follows: tensile strength at break (MD) of 150.
kg / cm ² or more, elongation at break is 400% or more, and Young's modulus of the film is 1,000 kg / cm ² or more. When the breaking strength is 150 kg / cm ² or more,
In general, it is a great feature because it is excellent in strength as a packaging film and can be used for packaging heavy objects. On the other hand, 150
If it is less than kg / cm ² , the utility value is reduced due to insufficient strength.

The feature of the present film is that the breaking elongation is 400% or more, and the breaking strength is 200 kg.
/ Cm ² is effective because of this elongation at break, and has a large elongation at break of 400% or more against projections and various impacts. If the breaking strength is less than 400%, the film having a breaking strength of about 200 kg / cm ² easily breaks due to piercing impact force or the like.

The Young's modulus is 1,000 to 2,500 k
Films at the g / cm ² level have excellent flexibility and are suitable as soft materials in combination with high transparency. Also,
Films of 2,500 kg / cm ² or more are excellent in automatic packaging suitability. If it is less than 1,000 kg / cm ^2, it is not preferable in terms of easy handling.

The film produced by the T-die method was particularly excellent in the uniformity of its thickness, and the uniformity in thickness deviation could be made uniform within ± 3%. In addition, physical properties are as follows: tensile breaking strength (MD) is 150 kg / cm ² or more, breaking elongation is 200% or more, and film Young's modulus is 600 kg.
/ Cm ² or more. Having a breaking strength of 150 kg / cm ² or more is a great feature because it generally has excellent strength as a packaging film and can be used for packaging heavy objects. On the other hand, if it is less than 150 kg / cm ² , the strength of the flat film when processed at high speed in secondary processing or the like is insufficient, and loss due to trouble increases, which is not preferable.
Further, the present film is characterized in that the elongation at break is 200% or more.
Since it has a breaking elongation of 0% or more, it has great characteristics as a packaging material without breaking. If it is less than 200%, it easily breaks due to piercing impact force or the like, which is not preferable. Further, a film having a Young's modulus of 600 kg / cm ² or more has a T-
A feature of the die method is that the film can be formed at a speed of 100 to 200 m / min, which is several times faster than that of the inflation method, and the Young's modulus is greatly increased. Therefore, this film is more excellent for automatic packaging and automatic bag making at high speed.
If it is less than 600 kg / cm ^2, it is not preferable in terms of suitability for the secondary processing by the high speed.

When the polyester of the present invention is used, it is needless to say that a lubricant, a wax, a coloring agent, a filler and the like can be used in combination, if necessary. In particular, when forming a film of this resin, besides the conventional lubricant, it is especially VITO
A lubricant such as N was very effective in obtaining a film of good quality, particularly a film having good surface smoothness.

[0053]

The present invention has been developed for the purpose of providing a film having high transparency, microbial decomposability, heat sealability, and low combustion heat generation.

First, an aliphatic polyester is selected from resins satisfying the requirements of biodegradability and low combustion heat generation,
Using a small amount of a coupling agent, a melting point of 70 to 200 ° C, a temperature of 190 ° C, and a shear rate of 100 seconds
a melt viscosity at c ^-1 of 2,000 to 100,000;
The problem was overcome by using an aliphatic polyester resin having a number average molecular weight of 20,000 or more.

The conventional aliphatic polyester resin cannot be generally blown-molded, but in the present invention, it can be molded by selecting the above polyester resin.

In particular, in the water-cooled inflation molding method, the molten film is brought into direct contact with water and solidified (formed into a film).
Since it is a method to make it transparent, it is an excellent method to improve transparency, but with a resin with good crystallinity, for example, polyethylene etc., the slight difference in cooling at the moment of cooling and solidifying in contact with water, as cooling unevenness as it is Water-cooled inflation films are not often used because they remain on the film and often become defective as distortions such as wrinkles and tarmi.

Fortunately, it is presumed that the polyester resin which is the object of the present invention has a low crystallization speed. However, as a result of trying the molding by the water-cooled inflation method, the molding is performed very stably and the obtained product is obtained. It was found that no wrinkles or tarls were generated on the resulting film, and a high-quality, highly transparent film was obtained.

In the case of the T-die method film, a flat film having a small thickness non-uniformity and excellent in transparency and gloss can be obtained, but the resin of the present invention has a performance extremely suitable for this processing method. With good productivity (100m / min
The above high-speed molding is possible. ) A film with excellent mechanical properties is obtained. Hereinafter, the present invention will be described with reference to Examples and Comparative Examples.

[0059]

【Example】

(Example 1) After replacing a 700 L reactor with nitrogen,
183 kg of 1,4-butanediol, 224 k of succinic acid
g. The temperature was increased in a nitrogen stream, and 192
At 220 ° C. for 3.5 hours, further stopping nitrogen and
The esterification reaction by dehydration condensation was performed under reduced pressure of 2 mmHg for 3.5 hours. The collected sample had an acid value of 9.2 mg / g, a number average molecular weight (Mn) of 5,160,
The weight average molecular weight (Mw) was 10,670.
Subsequently, 34 g of tetraisopropoxytitanium as a catalyst was added under a nitrogen stream at normal pressure. The temperature was increased, and 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) was 339 kg excluding condensed water.

To a reactor containing 339 kg of polyester (A1), 5420 g 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. Next, 1700 g of Irganox 1010 (manufactured by Ciba Geigy) as an antioxidant and 1700 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. 90 ° C
The yield of the polyester (B1) after vacuum-drying 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 (gel chromatography manufactured by Showa Denko KK), solvent: CF ₃ COONa 5 mmol solution of hexafluoroisopropyl alcohol, concentration 0.1% by weight, calibration curve: PMMA standard sample manufactured by Showa Denko KK
Performed on a Shodex Standard M-75.

Then, this polyester resin (B1) was extruded using an extruder having a screw diameter of 40 mmφ and L / D = 28.
50m at a resin temperature of 170 ° C (cylinder and die)
mφ spiral die (lip gap 1.2mm)
Extruded, cooled with air from an air ring by the usual air-cooled inflation method, and withdrawal speed of 20 m / m
in, folding diameter 200mm (blow ratio 2.55), thickness 30
A μm tubular film was formed. Stable film formation was achieved by adjusting the air volume of the blower and the air ring to control the cooling conditions.

The obtained film was formed by a haze (ASTM D
-523, the same applies hereinafter) of 12%, tensile strength at break (JIS)
Z-1702, the same applies hereinafter) is very strong at 650 kg / cm ² , has a tensile elongation at break (JIS Z-1702, the same applies hereinafter) of 350%, and has a Young's modulus (ASTM D-82).
2, the same applies hereinafter) at 3,300 kg / cm ² , sufficient physical properties as a packaging film were obtained. In addition, this film can be heat-sealed with a heat sealer on a hot plate.
800 g / 15 m at time 1 sec, pressure 1 kg / cm ²
A seal strength of m width was obtained.

When this film was buried in the soil for 2 months and the strength was measured, the breaking strength and elongation were significantly reduced to 300 kg / cm ² and 190%, respectively.
It became clear that decomposition occurred in the soil.

Example 2 The polyester resin (B1) used in Example 1 was screwed with a diameter of 40 mmφ and L / D = 2.
Extruder is extruded from a 50 mmφ spiral die (lip gap 1.2 mm) at a resin temperature of 200 ° C. (cylinder and die) using an extruder of No. 8, cooled by air from an air ring by a normal air-cooled inflation method, and a take-up speed of 30 m / A tubular film having a minimum length of 200 mm (blow ratio 2.55) and a thickness of 20 μm was formed. Stable film formation was achieved by adjusting the air volume of the blower and the air ring to control the cooling conditions.

[0066] The resulting film 9 percent haze, tensile strength at break 720 kg / cm ² and very strong, tensile elongation Yes 320%, Young's modulus obtained sufficient properties as a packaging film 4500 kg / cm ² Was done. The film can be heat-sealed with a heat sealer on a hot plate.
800 g at 20 ° C., time 1 sec, pressure 1 kg / cm ²
A seal strength of / 15 mm width was obtained.

Example 3 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 tetraisopropoxy titanium as a catalyst was added under a nitrogen stream at normal pressure. Raise the temperature to 15 at a temperature of 210-220 ° C.
The deglycol-reaction was performed under a reduced pressure of 0.2 mmHg for 6.5 hours. The collected sample has a number average molecular weight (M
n) is 17,300 and the weight average molecular weight (Mw) is 4
6,400. The yield of this polyester (A2) was 337 kg excluding condensed water.

4.66 kg of hexamethylene diisocyanate was placed in a reactor containing 333 kg of polyester (A2).
Was added and a coupling reaction was performed at 180 to 200 ° C. for 1 hour. The viscosity increased rapidly but no gelling occurred. Next, 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 an additional 30
Stirring was continued for 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.

This polyester resin (B2) was extruded from a 50 mmφ spiral die (lip gap 1.2 mm) at a resin temperature of 170 ° C. (cylinder and die) using an extruder having a screw diameter of 40 mmφ and L / D = 28. It is cooled by air from an air ring by a normal air-cooled inflation method, and a take-up speed of 20 m / min.
A tubular film having a folded diameter of 160 mm (blow ratio 2.0) and a thickness of 50 μm was formed. Stable film formation was achieved by adjusting the air volume of the blower and the air ring to control the cooling conditions.

The resulting film has a very high haze of 10%, a tensile strength at break of 730 kg / cm ² , a large tensile elongation of 400%, and a Young's modulus of 2800 kg / cm ^2.
As a result, sufficient physical properties as a packaging film were obtained. Also,
This film can be heat-sealed with a hot plate heat sealer.
115 ° C., time 1 sec, pressure 1 kg / cm ²
A seal strength of 100 g / 15 mm width was obtained.

When this film was buried in the soil for 3 months and the strength was measured, the breaking strength and the elongation were significantly reduced to 280 kg / cm ² and 160%, respectively. It became clear that.

Example 4 The polyester resin (B2) used in Example 3 was screwed with a diameter of 40 mmφ and L / D = 2.
Extruder is extruded from a 50 mmφ spiral die (lip gap 1.2 mm) at a resin temperature of 150 ° C. (cylinder and die) using an extruder of No. 8, cooled by air from an air ring by a usual air-cooled inflation method, and a take-up speed of 10 m / A tubular film having a min length of 160 mm (blow ratio of 2.0) and a thickness of 100 μm was formed. Stable film formation was achieved by adjusting the air volume of the blower and the air ring to control the cooling conditions.

The obtained film had a very high haze of 18%, a tensile strength at break of 700 kg / cm ² , a very high tensile elongation of 380%, and a Young's modulus of 2500 kg / cm ^2. Was done. This film can be heat-sealed with a heat sealer of a hot plate. Heat sealing conditions: temperature 115 ° C., time 1 sec, pressure 1 kg
/ Cm ² , a seal strength of 1100 g / 15 mm width was obtained.

(Example 5) 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 tetraisopropoxy titanium 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 4.5 hours. The collected sample is number average molecular weight (Mn)
Is 33,400 and the weight average molecular weight (Mw) is 13
It was 7,000. 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. Next, 1.62 kg of Irganox 1010 (manufactured by Ciba Geigy) as an antioxidant and 1.62 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 a pellet by a cutter. 9
Polyester (B3) after vacuum drying at 0 ° 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, the MFR (190 ° C) is 1.1 g / 10 min, the viscosity of a 10% solution of orthochlorophenol is 96 poise, Temperature 190 ° C, shear rate 100
The melt viscosity at sec ^-1 was 1.6 × 10 ⁴ poise.

The polyester resin (B3) was extruded using an extruder having a screw diameter of 55 mmφ and L / D = 28, and a resin temperature of 1
It is extruded from a 100 mmφ spiral die (lip gap 2.2 mm) at 70 ° C. (cylinder and die), cooled with air from an air ring by a normal air-cooled inflation method, a take-up speed of 20 m / min, and a folding diameter of 470 mm (blow ratio of 3. 0), a tubular film having a thickness of 30 μm was formed. Stable film formation was achieved by adjusting the air volume of the blower and the air ring to control the cooling conditions.

The resulting film has a haze of 15%, a tensile strength at break of 800 kg / cm ^2, and a tensile elongation of 45 kg.
At 0%, the Young's modulus was 2500 kg / cm ² , and sufficient physical properties as a packaging film were obtained. Further, the heat sealing strength was as large as 1.5 kg / 15 mm width at a sealing condition temperature of 115 ° C., a time of 1 sec, and a pressure of 1 kg / cm ² , and good sealing was achieved.

Example 6 A 700 L reactor was purged with nitrogen, and then 200 kg of 1,4-butanediol (molar ratio: 105), 250 kg of succinic acid and 2.8 kg of trimethylolpropane were charged. The temperature was raised under a nitrogen stream, and the esterification reaction by dehydration condensation was performed at 192 to 220 ° C. for 4.5 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 10.4 mg / g and a number average molecular weight (Mn).
Is 4,900, and the weight average molecular weight (Mw) is 10,0.
00. Subsequently, 37 g of titanium tetraisopropoxide as a catalyst was added under a nitrogen stream at normal pressure. Raise the temperature, 15 ~
The deglycol-reaction was performed under a reduced pressure of 1.0 mmHg for 8.0 hours. The collected sample is number average molecular weight (Mn)
Is 16,900, and the weight average molecular weight (Mw) is 90,
300 (Mw / Mn 5.4). The yield of this polyester (A4) was 367 kg excluding the theoretical amount of condensed water of 76 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. Next, 367 g of Irganox 1010 (manufactured by Ciba Geigy) as an antioxidant and 367 g of calcium stearate as a lubricant were added, and the mixture was further stirred for 30 minutes. This reaction product was extruded into water with an extruder and cut into a pellet by a cutter. 6 at 90 ° C
The yield of the polyester (B4) after drying under vacuum for an hour 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 100 sec ⁻¹ was 2.0 × 10 ⁴ poise. The measurement of the average molecular weight is
Shodex GPC System-11 (manufactured by Showa Denko KK, gel chromatography), and the solvent is CF ₃ COON
a 2 mmol solution of HFIPA, concentration: 0.1% by weight, and the calibration curve is PMMA standard sample Shod manufactured by Showa Denko KK
ex Standard M-75.

The polyester resin (B4) was extruded using an extruder having a screw diameter of 55 mmφ and L / D = 28, and a resin temperature of 1
Extruded from a 100 mmφ spiral die (lip gap 2.2 mm) at 80 ° C. (cylinder and die), cooled with air from an air ring by a usual air-cooled inflation method, a take-up speed of 20 m / min, and a folded diameter of 628 mm (blow ratio of 4.28). 0), a tubular film having a thickness of 30 μm was formed. By adjusting the air volume of the blower and the air ring to control the cooling conditions, the bubbles were extremely stabilized, and a good quality film could be formed.

The obtained film had a haze of 9%, a tensile strength at break of 900 kg / cm ² and a tensile elongation of 550.
% And a Young's modulus of 2500 kg / cm ² , sufficient properties as a packaging film were obtained. In addition, the heat sealing strength was as follows: sealing conditions: temperature 115 ° C., time 1 sec, pressure 1
The width was as large as 2.0 kg / 15 mm in kg / cm ² , and good sealing was achieved.

When this film was buried in the soil for 2 months and the strength was measured, the breaking strength and elongation were significantly reduced to 300 kg / cm ² and 190%, respectively.
It became clear that decomposition occurred in the soil.

Example 7 A composition obtained by blending 50% of the polyester resin (B1) used in Example 1 and the polyester resin (B4) used in Example 6 had a screw diameter of 40 mmφ and L / D = 28. Using an extruder, resin temperature 2
Extruded from a 50 mmφ spiral die (lip gap 1.2 mm) at 00 ° C (cylinder and die)
It is cooled by air from an air ring by the usual air-cooled inflation method, the take-off speed is 30 m / min, and the folding diameter is 2
A tubular film having a thickness of 20 mm and a thickness of 20 mm (blow ratio 2.55) was formed. Stable film formation was achieved by adjusting the air volume of the blower and the air ring to control the cooling conditions.

The resulting film has a very high haze of 8%, a tensile strength at break of 800 kg / cm ² , a very high tensile elongation of 400%, and a Young's modulus of 4000 kg / cm ² , sufficient properties as a packaging film. Was done. The film can be heat-sealed with a heat sealer on a hot plate.
1200 ° C. at 20 ° C., time 1 sec, pressure 1 kg / cm ²
A seal strength of g / 15 mm width was obtained.

When this film was buried in soil for 2 months and the strength was measured, the breaking strength and elongation were significantly reduced to 300 kg / cm ² and 190%, respectively.
It became clear that decomposition occurred in the soil.

Comparative Example 1 A polyester resin (B1) was extruded at a resin temperature of 250 ° C. (cylinder and die) using an extruder having a screw diameter of 40 mmφ and L / D = 28.
0mmφ spiral die (Lip gap 1.2m
m), it was cooled by air from an air ring by an ordinary air-cooled inflation method, and an attempt was made to mold. However, bubbles were deformed, and gel was generated frequently, resulting in puncture, and film formation was not possible.

Comparative Example 2 A polyester resin (B1) was extruded at a resin temperature of 118 ° C. (cylinder and die) using an extruder having a screw diameter of 40 mmφ and L / D = 28.
0mmφ spiral die (Lip gap 1.2m
m) Extruded, cooled with air from an air ring by the usual air-cooled inflation method, and tried to mold. However, the viscosity of the molten resin from the die outlet was so large that it could be cut without elongation and the film could be formed. Did not.

Example 8 The polyester resin (B1) used in Example 1 was prepared by using a screw having a diameter of 40 mmφ and L / D = 2.
Extruder is extruded from a 50 mmφ spiral die (lip gap 1.2 mm) at a resin temperature of 190 ° C. (cylinder and die) using an extruder of No. 8 and cooled with water from a water-cooled ring (water temperature of 10 ° C.) by a normal water-cooled inflation method. And take-off speed 20m / min, folding diameter 200mm
(Blow ratio 2.55), a 30 μm-thick tubular film was formed. Stable film formation was achieved by adjusting the amount of water in the water-cooled ring and the distance between the dice and the water-cooled ring to control the cooling conditions.

The obtained film had a very high haze of 4%, a tensile strength at break of 400 kg / cm ² , a tensile elongation of 600%, a Young's modulus of 2,000 kg / cm ² and sufficient physical properties as a packaging film. was gotten. This film can be heat-sealed with a heat sealer of a hot plate, and heated at a temperature of 115 ° C. for 1 ^second at a pressure of 1 kg / cm ² for 120 hours.
A seal strength of 0 g / 15 mm width was obtained.

When this film was buried in the soil for 2 months and the strength was measured, the breaking strength and elongation were significantly reduced to 220 kg / cm ² and 180%, respectively.
It became clear that decomposition occurred in the soil.

Example 9 The polyester resin (B1) used in Example 1 was screwed with a diameter of 40 mmφ and L / D = 2.
Using an extruder of No. 8, extrude from a 50 mmφ spiral die (lip gap 1.2 mm) at a resin temperature of 210 ° C. (cylinder and die), and cool with water from a water cooling ring (water temperature of 10 ° C.) by a normal water cooling inflation method. And take-off speed 30m / min, folding diameter 200mm
(Blow ratio 2.55), a 20-μm-thick tubular film was formed. Stable film formation was achieved by adjusting the amount of water in the water-cooling ring and the distance between the die and the water-cooling ring in order to control the cooling conditions.

The obtained film had a very high haze of 3%, a tensile strength at break of 480 kg / cm ² , a tensile elongation of 520%, and a Young's modulus of 2800 kg / cm ² , sufficient physical properties as a packaging film. Was done. The film can be heat-sealed with a heat sealer on a hot plate.
1200 at 15 ° C., time 1 sec, pressure 1 kg / cm ²
A seal strength of g / 15 mm width was obtained.

Example 10 The polyester resin (B2) used in Example 3 was screwed with a diameter of 40 mmφ and L / D =
Using a 28 extruder, extrude from a 50 mmφ spiral die (lip gap 1.2 mm) at a resin temperature of 170 ° C. (cylinder and die) and cool with water from a water-cooled ring (water temperature of 10 ° C.) by the usual water-cooled inflation method. And take-off speed 20m / min, folding diameter 160m
m (blow ratio: 2.0) and a 50 μm thick tubular film were formed. Stable film formation was achieved by adjusting the amount of water in the water-cooling ring and the distance between the die and the water-cooling ring in order to control the cooling conditions.

The resulting film has a very high haze of 4%, a tensile strength at break of 610 kg / cm ² , a large tensile elongation of 620%, a Young's modulus of 2200 kg / cm ² and sufficient physical properties as a packaging film. Obtained. This film can be heat-sealed with a heat sealer of a hot plate, and heated at a temperature of 115 ° C. for 1 ^second at a pressure of 1 kg / cm ² .
A seal strength of 00 g / 15 mm width was obtained.

When this film was buried in the soil for 3 months and its strength was measured, the breaking strength and elongation were greatly reduced to 320 kg / cm ² and 310%, respectively. It became clear that.

Example 11 The polyester resin (B2) used in Example 3 was screwed with a diameter of 40 mmφ and L / D =
Using a 28 extruder, extrude from a 50 mmφ spiral die (lip gap 1.2 mm) at a resin temperature of 150 ° C. (cylinder and die), and cool with water from a water cooling ring (water temperature of 10 ° C.) by a normal water cooling inflation method. And take-up speed 10m / min, folding diameter 160m
m (blow ratio: 2.0) and a 100 μm-thick tubular film were formed. Stable film formation was achieved by adjusting the amount of water in the water-cooling ring and the distance between the die and the water-cooling ring in order to control the cooling conditions.

The resulting film had a very strong haze of 7.5%, a tensile strength at break of 580 kg / cm ² , a tensile elongation of 600%, and a Young's modulus of 2500 kg / cm ^2, which was sufficient physical properties as a packaging film. was gotten. This film can be heat-sealed with a heat sealer of a hot plate. Heat sealing conditions: 115 ° C., time 1 sec, pressure 1 k
At 1 g / cm ² , a seal strength of 1400 g / 15 mm width was obtained.

(Example 12) Polyester resin (B3)
Using an extruder having a screw diameter of 55 mmφ and L / D = 28 at a resin temperature of 180 ° C. (cylinder and die).
0mmφ spiral die (lip gap 2.2m
m), cooled with water from a water-cooled ring (water temperature 10 ° C.) by a normal water-cooled inflation method, a take-up speed of 20 m / min, and a folded diameter of 470 mm (blow ratio of 3.
0), a tubular film having a thickness of 30 μm was formed.
Stable film formation was achieved by adjusting the amount of water in the water-cooling ring and the distance between the die and the water-cooling ring in order to control the cooling conditions.

The obtained film had a haze of 3%, a tensile strength at break of 670 kg / cm ^2, and a tensile elongation of 620.
%, And the Young's modulus was 1,800 kg / cm ² , whereby sufficient physical properties as a packaging film were obtained. In addition, the heat sealing strength was as follows: sealing conditions: temperature 115 ° C., time 1 sec, pressure 1
The width was as large as 1800 g / 15 mm in kg / cm ² , and a good seal was obtained.

Example 13 The polyester resin (B4) used in Example 6 was screwed with a screw diameter of 55 mmφ and L / D =
Using an extruder of No. 28, extruded from a 100 mmφ spiral die (lip gap 2.2 mm) at a resin temperature of 190 ° C. (cylinder and die), and cooled with water from a water-cooled ring (water temperature of 10 ° C.) by a normal water-cooled inflation method. Pickup speed 20m / min, folding diameter 470mm
(Blow ratio: 3.0), a 30 μm-thick tubular film was formed. By adjusting the amount of water in the water-cooling ring and the distance between the die and the water-cooling ring in order to control the cooling conditions, the bubbles were very stable and a good quality film could be formed.

The obtained film had a haze of 2.5%, a tensile strength at break of 800 kg / cm ² and a tensile elongation of 5 kg.
With a Young's modulus of 1500 kg / cm ² , sufficient physical properties as a packaging film were obtained. Further, the heat sealing strength is as large as 2.0 kg / 15 mm width at a sealing condition temperature of 115 ° C., time of 1 sec, and pressure of 1 kg / cm ² ,
Good seal was obtained.

When this film was buried in the soil for 2 months and the strength was measured, the breaking strength and elongation were greatly reduced to 200 kg / cm ² and 150%, respectively. It became clear that.

Example 14 A composition obtained by blending 50% of the polyester resin (B1) used in Example 1 and the polyester resin (B4) used in Example 6 had a screw diameter of 40 mmφ and L / D = 28. Using an extruder, extrude from a 50 mmφ spiral die (lip gap 1.2 mm) at a resin temperature of 200 ° C. (cylinder and die), cool with water from a water-cooled ring (water temperature of 10 ° C.) by ordinary water-cooled inflation method, and take off Speed 30m /
min, folding diameter 200mm (blow ratio 2.55), thickness 2
A 0 μm tubular film was formed. Very stable film formation was achieved by adjusting the amount of water in the water-cooling ring and the distance between the die and the water-cooling ring in order to control the cooling conditions.

The obtained film had a very strong haze of 2%, a tensile strength at break of 700 kg / cm ² , a tensile elongation of 400%, and a Young's modulus of 2000 kg / cm ^2, which showed sufficient physical properties as a packaging film. Was done. The film can be heat-sealed with a heat sealer on a hot plate.
1200 ° C. at 20 ° C., time 1 sec, pressure 1 kg / cm ²
A seal strength of g / 15 mm width was obtained.

When this film was buried in the soil for 2 months and the strength was measured, the breaking strength and elongation were significantly reduced to 220 kg / cm ² and 150%, respectively, and decomposition occurred in the soil. It became clear that.

Comparative Example 3 A polyester resin (B1) was extruded at a resin temperature of 250 ° C. (cylinder and die) using an extruder having a screw diameter of 40 mmφ and L / D = 28.
0mmφ spiral die (Lip gap 1.2m
m), it was cooled with water from a water-cooled ring (water temperature of 10 ° C.) by a normal water-cooled inflation method, and molding was attempted. However, bubbles were deformed, and gel was generated frequently, resulting in puncture and failure to form a film. Was.

Comparative Example 4 A polyester resin (B1) was extruded at a resin temperature of 115 ° C. (cylinder and die) using an extruder having a screw diameter of 40 mmφ and L / D = 28.
0mmφ spiral die (Lip gap 1.2m
m), it was cooled with water from a water-cooled ring (water temperature of 10 ° C.) by a normal water-cooled inflation method, and the molding was attempted. Could not be formed.

(Example 15) The polyester resin (B1) used in Example 1 was screwed with a screw diameter of 65 mmφ and L / D =
Using a 32 extruder, extruding from a 500 mm width T-die (lip gap 1.2 mm) at a resin temperature of 190 ° C. (cylinder and die), and setting the chill roll temperature to 200
Under the condition of ° C, the take-off speed is 120 m / min, and the thickness is 2
A flat film having a thickness of 0 μm and a product width of 200 mm was formed. Stable film formation was achieved by adjusting the air volume of the air knife and the air gap in order to control the cooling conditions.

[0112] The resulting film haze of 4%, the tensile breaking strength is very strong and 800 kg / cm ^2, tensile elongation Yes 300%, sufficient properties as a packaging film Young's modulus at 5,200kg / cm ² was gotten. This film can be heat-sealed by a heat sealer of a hot plate and has a temperature of 12 ° C.
1200 g at 0 ° C., time 1 sec, pressure 1 kg / cm ²
A seal strength of / 15 mm width was obtained.

When this film was buried in the soil for two months and the strength was measured, the breaking strength and elongation were greatly reduced to 320 kg / cm ² and 160%, respectively, and decomposition occurred in the soil. It became clear that.

(Example 16) The polyester resin (B1) used in Example 1 was screwed with a screw diameter of 65 mmφ and L / D =
Using a 32 extruder, extrude from a 500 mm width T-die (lip gap 1.2 mm) at a resin temperature of 170 ° C. (cylinder and die), and set the chill roll temperature at 20 ° C.
Under the conditions described above, a take-off speed of 40 m / min and a thickness of 20 μm
m, a flat film having a product width of 200 mm was formed.
Stable film formation was achieved by adjusting the air volume and air gap of the air knife to control the cooling conditions.

The obtained film had a very high haze of 7%, a tensile strength at break of 620 kg / cm ² , a tensile elongation of 510%, and a Young's modulus of 3800 kg / cm ² , sufficient physical properties as a packaging film. Was done. The film can be heat-sealed with a heat sealer on a hot plate.
1200 ° C. at 20 ° C., time 1 sec, pressure 1 kg / cm ²
A seal strength of g / 15 mm width was obtained.

Example 17 The polyester resin (B2) used in Example 3 was screwed with a screw diameter of 65 mmφ and L / D =
Using a 32 extruder, extrude from a 500 mm width T-die (lip gap 1.2 mm) at a resin temperature of 170 ° C. (cylinder and die), and set the chill roll temperature at 20 ° C.
Under the conditions described above, a take-off speed of 150 m / min and a thickness of 20
A flat film having a thickness of 350 μm and a product width of 350 mm was formed. Stable film formation was achieved by adjusting the air knife airflow and air gap to control the cooling conditions.

The resulting film had a very high haze of 3.5%, a tensile strength at break of 840 kg / cm ² , a very high tensile elongation of 280% and a Young's modulus of 5100 kg / cm ^2.
In Example ² , sufficient physical properties as a packaging film were obtained. The film can be heat-sealed with a heat sealer of a hot plate, at a temperature of 115 ° C., for 1 ^second , and at a pressure of 1 kg / cm ^2.
With this, a sealing strength of 1500 g / 15 mm width was obtained.

When this film was buried in the soil for 3 months and the strength was measured, the breaking strength and the elongation were greatly reduced to 340 kg / cm ² and 120%, respectively. It became clear that.

(Example 18) The polyester resin (B2) used in Example 3 was screwed with a diameter of 65 mmφ and L / D =
Using a 32 extruder, extrude from a 500 mm width T-die (lip gap 1.2 mm) at a resin temperature of 150 ° C. (cylinder and die), and set the chill roll temperature at 20 ° C.
Under the conditions described above, a take-up speed of 90 m / min and a thickness of 30 μm
m, a flat film having a product width of 350 mm was formed.
Stable film formation was achieved by adjusting the air volume of the air knife and the air gap to control the cooling conditions.

The obtained film had a very high haze of 5.0%, a tensile strength at break of 660 kg / cm ² , a tensile elongation of 370%, a Young's modulus of 5,200 kg / cm ² and sufficient physical properties as a packaging film. was gotten. This film can be heat-sealed with a heat sealer of a hot plate. Heat sealing conditions: 115 ° C., time 1 sec, pressure 1 k
At 1 g / cm ² , a seal strength of 1400 g / 15 mm width was obtained.

Example 19 The polyester resin (B3) used in Example 5 was screwed with a screw diameter of 65 mmφ and L / D =
Using a 32 extruder, extruding from a 500 mm width T-die (lip gap 2.2 mm) at a resin temperature of 200 ° C. (cylinder and die), a chill roll temperature of 5 ° C., a take-up speed of 120 m / min, 20μ thickness
m, a flat film having a product width of 400 mm was formed.
Stable film formation was achieved by adjusting the air volume of the air knife and the air gap to control the cooling conditions.

The obtained film had a very high haze of 2.8%, a tensile strength at break of 820 kg / cm ² , a tensile elongation of 300%, a Young's modulus of 5,500 kg / cm ² and sufficient physical properties as a packaging film. was gotten. The heat sealing strength was 115 ° C. for 1 sec.
c, The width was 1800 g / 15 mm wide at a pressure of 1 kg / cm ² , and a good seal was obtained.

(Example 20) The polyester resin (B4) used in Example 6 was screwed with a screw diameter of 65 mmφ and L / D =
Using a 32 extruder, extruding from a 500 mm width T-die (lip gap 2.2 mm) at a resin temperature of 200 ° C. (cylinder and die), a chill roll temperature of 5 ° C., a take-up speed of 50 m / min, Thickness 50μ
m, a flat film having a product width of 400 mm was formed.
By controlling the air volume and air gap of the air knife to control the cooling conditions, a very stable and good quality film could be formed.

The resulting film had a haze of 4.5%, a tensile strength at break of 900 kg / cm ² and a tensile elongation of 5 kg.
With a Young's modulus of 1200 kg / cm ² , sufficient physical properties as a packaging film were obtained. Further, the heat sealing strength is as large as 2500 g / 15 mm width at a sealing condition temperature of 115 ° C., time of 1 sec, and pressure of 1 kg / cm ² ,
Good seal was obtained.

When this film was buried in the soil for two months and the strength was measured, the breaking strength and elongation were significantly reduced to 320 kg / cm ² and 180%, respectively.
It became clear that decomposition occurred in the soil.

Example 21 A composition obtained by blending 50% of the polyester resin (B4) used in Example 6 with the polyester resin (B1) used in Example 1 was used.
Using an extruder with 5 mmφ, L / D = 32, resin temperature 20
At 0 ° C (cylinder and die), 500mm width T-
Extruded from a die (lip gap 1.2 mm), the take-up speed was 120 m /
A flat film having a thickness of 20 μm and a product width of 400 mm was formed. Extremely stable film formation was achieved by adjusting the air volume and air gap of the air knife to control the cooling conditions.

[0127] The resulting film haze of 2%, tensile strength at break is very strong and 820kg / cm ^2, tensile elongation There is also a 400%, the Young's modulus is obtained sufficient physical properties as a packaging film at 800kg / cm ² Was done. The film can be heat-sealed with a heat sealer on a hot plate.
1,200 g / at 1 ° C, 1 sec / pressure, 1 kg / cm ²
A seal strength of 15 mm width was obtained.

When this film was buried in the soil for 2 months and the strength was measured, the breaking strength and elongation were significantly reduced to 250 kg / cm ² and 150%, respectively, and decomposition occurred in the soil. It became clear that.

Comparative Example 5 A polyester resin (B1) was extruded at a resin temperature of 250 ° C. (cylinder and die) using an extruder having a screw diameter of 65 mmφ and L / D = 32.
00mm width T-die (lip gap 1.2mm)
And a chill roll temperature of 20 ° C., a take-off speed of 120 m / min, a thickness of 20 μm, and a product width of 20 μm.
An attempt was made to form a flat film of 0 mm, but the stability of the molten film between air gaps was poor, and it was difficult to form a film having a uniform thickness.

Comparative Example 6 A polyester resin (B1) was extruded at a resin temperature of 118 ° C. (cylinder and die) using an extruder having a screw diameter of 65 mmφ and L / D = 32.
00mm width T-die (lip gap 1.2mm)
And a chill roll temperature of 20 ° C., a take-off speed of 120 m / min, a thickness of 20 μm, and a product width of 20 μm.
An attempt was made to form a 0 mm flat film. However, the viscosity of the molten resin coming out of the exit of the die was so large that the molten resin was cut without elongation, and a film could not be formed.

[0131]

According to the present invention, an aliphatic polyester resin having a relatively high molecular weight and having a terminal hydroxy group is formed into a high molecular weight aliphatic polyester resin without being gelled by using a small amount of a coupling agent, and is air-cooled inflation molding. And water-cooled inflation molding or T-die flat film molding.

Even if the film of the present invention is a polyester film, unlike a conventional polyester film (polyethylene terephthalate resin film), it is a film having a biodegradability and a heat sealing property. These films also have a lower calorific value and a less problem of disposal than polyolefin resins such as polyethylene and polypropylene.

Further, since the film is subjected to the coupling treatment while being an aliphatic polyester resin, the film is excellent in heat stability and mechanical strength, and can be used as it is as a heat seal packaging material.

──────────────────────────────────────────────────続 き Continuation of the front page (51) Int.Cl. ⁶ Identification code FI C08L 67:00 (56) References JP-A-5-271377 (JP, A) JP-A-3-111418 (JP, A) JP-A-3-115418 (JP, A) JP-A-55-145734 (JP, A) JP-A-54-21496 (JP, A) JP-A-51-49591 (JP, A) US Patent 3,508,862 (US, A) U.S. Pat. No. 2999851 (US, A) UK Patent 627270 (GB, A)

Claims (8)

(57) [Claims] 1. An aliphatic polyester prepolymer synthesized mainly from glycol and an aliphatic dibasic acid or a derivative thereof (excluding a hydroxyl group-containing dibasic acid), which is obtained by reacting a coupling agent with an aliphatic polyester prepolymer. Temperature 1
The melt viscosity at 90 ° C. and a shear rate of 100 (sec ⁻¹ ) is 2,000 to 100,000 poise, and the melting point is 7
A polyester film formed from an aliphatic polyester having a temperature of 0 to 200 ° C and having a thickness of 10 to 150 µm. 2. The aliphatic polyester according to claim 1, which is mainly synthesized from glycol and an aliphatic dibasic acid or a derivative thereof, is molded at a molding temperature of 120 to 240.degree. The thickness formed in the range of 5 to 6.0 is 1
Air-cooled blown film of 0 to 150 μm. 3. A tensile strength at break (MD) of 300 kg / c.
m ² or more, elongation at break of 200% or more, air-cooling blown film according to claim 1 or claim 2 wherein the film a Young's modulus is 2,000 kg / cm ² or more. 4. The aliphatic polyester according to claim 1, which is mainly synthesized from glycol and an aliphatic dibasic acid or a derivative thereof, at a molding temperature of 120 to 240 ° C. and a blow-up ratio of 1.0 to 4.0. And a highly transparent water-cooled blown film having a thickness of 10 to 150 μm. 5. Haze 8% or less, tensile strength at break (MD)
Is 150 kg / cm ² or more, the breaking elongation is 400% or more,
The highly transparent water-cooled blown film according to claim 1 or 4, wherein the film has a Young's modulus of 600 kg / cm ² or more. 6. The thickness of the aliphatic polyester according to claim 1, which is mainly synthesized from a glycol and an aliphatic dibasic acid or a derivative thereof at a molding temperature of 120 to 240 ° C. Is 10 to 150 μ
m T-die flat film. 7. The tensile strength at break (MD) is 150 kg / c.
m ² or more, elongation at break of 200% or more, T-die flat film according to claim 1 or claim 6 wherein the film a Young's modulus is 600 kg / cm ² or more. 8. The aliphatic polyester having a number average molecular weight of 2
The polyester film according to any one of claims 1 to 7, wherein the polyester film has an MFR (190 ° C) of not less than 20,000 and not more than 20 g / 10 minutes.