JPH06172624A - Polyester resin composition - Google Patents

Abstract

PURPOSE:To provide a resin composition biodegradable by microorganisms, sealable as it is and having excellent heat resistance and mechanical properties and a low heat of combustion. CONSTITUTION:A polyester resin composition is obtained by blending an organic filler in an amount of 5-70wt.% based on the total resin composition with an aliphatic polyester resin having a number-average mol.wt. of >=10,000. The aliphatic polymer resin is produced by reacting a prepolymer obtained from glycol and a polybasic aliphatic acid with a coupling agent.

Description

Detailed Description of the Invention

[0001]

The present invention has a number average molecular weight of 10,
Mixing a filler with an aliphatic polyester having a practically sufficient high molecular weight of 000 or more and producing a small amount of heat when burned, and including the filler is microbial degradable, and has thermal stability and mechanical properties. The present invention relates to an aliphatic polyester resin composition having excellent strength, a sheet obtained by processing the same, and a secondary processed product thereof.

[0002]

2. Description of the Related Art High molecular weight polyesters (hereinafter referred to as
The high molecular weight polyester referred to herein means a number average molecular weight of 20,000 or more. It is no exaggeration to say that) is 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.

Although there is an example in which 2,6-naphthalenedicarboxylic acid is used instead of terephthalic acid, a polyester in which an aliphatic dicarboxylic acid is used as a dicarboxylic acid is molded into a sheet, a film, a fiber or the like and put into practical use. There can be no examples.

One of the reasons why it has not been put to practical use is that, even if it is crystalline, the melting point of the aliphatic polyester is almost 100 ° C. or less, and moreover, the thermal stability upon melting is poor. , And more importantly, the properties of the aliphatic polyester, especially the mechanical properties represented by the tensile strength, are extremely low, and even at the same level of the number average molecular weight as polyethylene terephthalate, it shows only a significantly inferior value, and no practicality is found. It was nothing else.

[0005] Researches for increasing the number average molecular weight of aliphatic polyesters to improve their physical properties seem to have not progressed satisfactorily due to their poor thermal stability.

Aromatic polyesters, such as polyethylene terephthalate, which are generally used in large quantities in the field of packaging containers and industrial materials, are not microbially degradable and can be decomposed forever by simply discarding them after use. However, it had problems such as incineration for complete treatment because it pollutes rivers, oceans, and soil.

[0007]

The present invention has a practically sufficient high molecular weight, excellent thermal stability and mechanical properties typified by tensile strength, and a filler even if it is discarded after use. It is also possible to provide an aliphatic polyester resin composition having a heat-sealability as it is, which can be decomposed by microorganisms including the above, is easy to dispose, and a sheet produced therefrom, and further a secondary molded article thereof. To aim.

[0008]

According to the present invention, a cellulosic organic filler is blended with an aliphatic polyester having a number average molecular weight of at least 10,000, which is synthesized from glycol and an aliphatic dibasic acid or its acid derivative. The above object was achieved by developing a high-rigidity aliphatic polyester resin composition characterized by the above.

Further, this aliphatic polyester resin composition has excellent mechanical properties when formed into a sheet, and such a sheet is formed into a molded article or part by subjecting the sheet to heat molding such as vacuum forming and pressure forming. The inventors have found that they have properties extremely suitable for the above, and have completed the present invention.

The aliphatic polyester referred to in the present invention is mainly composed of a polyester synthesized from glycols and an aliphatic dibasic acid or an acid anhydride thereof, and has a sufficiently high molecular weight. This is a product in which a relatively high molecular weight polyester prepolymer having hydroxyl groups at both ends is synthesized and then these prepolymers are further coupled by 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 a diisocyanate to form a polyurethane, which is used as a rubber, foam, paint or adhesive. Things to do are widespread.

However, the polyester prepolymers used in these polyurethane foams, paints and adhesives are low molecular weight prepolymers having a number average molecular weight of 2,000 to 2,500. In order to obtain practical properties as polyurethane, the amount of diisocyanate used should be 1 part with respect to 100 parts by weight of this low molecular weight prepolymer.
It should be 0 to 20 parts by weight. Thus, when a large amount of diisocyanate is added to the molten low molecular weight polyester at 150 ° C. or higher, gelation occurs and a melt-moldable resin cannot be obtained.

Further, as in the case of polyurethane rubber,
A method of adding a large amount of diisocyanate to convert the hydroxyl group to an isocyanate group and further increasing the number average molecular weight with glycol can be considered, but the amount of diisocyanate used is the same as that of the low molecular weight prepolymer as described above. Polymer 10
10 parts by weight or more is required for 0 parts by weight. At this time, if a heavy metal-based catalyst is used for the synthesis of polyester, the reactivity of the isocyanate group is significantly promoted, resulting in poor storage stability, crosslinking reaction, branch formation, and loss of meltability. As a result, the number average molecular weight is at most 2,500.
Is the limit.

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 having a substantially hydroxyl group. Number average molecular weight of 5,000 or more, preferably 10,
It is 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 if a small amount of coupling agent of 0.1 to 5 parts by weight is used, a polyester having good physical properties cannot be obtained. A polyester prepolymer having a number average molecular weight of 5,000 or more has a hydroxyl value of 30 or less, and a small amount of a coupling agent does not cause gelation during the reaction even under severe conditions such as a molten state, thereby producing a high molecular weight polyester. Can be synthesized.

Examples of glycols used include ethylene glycol, 1,4-butanediol, 1,6
-Hexanediol, decamethylene glycol, neopentyl glycol, 1,4-cyclohexanedimethanol and the like can be mentioned. Ethylene oxide can also be utilized. You may use these glycols together.

Aliphatic dibasic acids or their acid derivatives which react with glycols to form aliphatic polyesters include succinic acid, adipic acid, suberic acid, sebacic acid,
There are dodecanedioic acid, succinic anhydride, adipic anhydride, and lower alcohol esters such as dimethyl esters thereof, which are commercially available and can be used in the present invention. You may use together polybasic acid or its acid anhydride.

These glycols and dibasic acids are mainly aliphatic, but a small amount of other components such as a trifunctional or tetrafunctional polyhydric alcohol, oxycarboxylic acid or polycarboxylic acid may be used in combination. preferable.

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.

As the trifunctional oxycarboxylic acid, malic acid is practically advantageous, and as the tetrafunctional oxycarboxylic acid component, citric acid is practical because commercial products can be easily obtained at low cost.

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

Examples of the tetrafunctional polyvalent carboxylic acid (or acid anhydride thereof) include pyromellitic dianhydride, benzophenonetetracarboxylic acid anhydride, cyclopentanetetracarboxylic acid anhydride and the like.

The polyfunctional component is used in such a proportion that the number of moles of either the glycol component or the aliphatic (including cycloaliphatic) dicarboxylic acid (or its acid anhydride) component is 100.
5 mol% or less, preferably 0.5 mol% or more and 3 mol% or less in the case of a trifunctional component, and 3 mol% or less, preferably 0.2 mol% in the case of a tetrafunctional component, relative to the mol%. It is 2 mol% or less.

If the proportion of the trifunctional component used is more than 5 mol%, and if the proportion of the tetrafunctional component used is more than 3 mol%, the risk of gelation during the esterification reaction increases significantly.

The polyester prepolymer for an aliphatic polyester used in the present invention has a terminal group substantially having a hydroxyl group. For that purpose, glycols and dibasic acid (or its acid anhydride) used in the synthesis reaction are used. The use ratio of is required to use some excess of glycols.

The synthesis of relatively high molecular weight polyester prepolymers requires the use of a deglycolization reaction catalyst during the deglycolization reaction following esterification.

Examples of the deglycolization 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 with respect 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 esterification or 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.
It is more preferable that those having a melting point of 0 ° C. or higher and a melting point of 60 ° C. or higher can be easily obtained and have crystallinity.

In order to obtain the aliphatic polyester of the present invention, the above number average molecular weight is preferably 5,000 or more,
Coupling agents are preferably used in polyester prepolymers having 10,000 or more end groups substantially having hydroxyl groups to further increase the number average molecular weight.

Examples of the coupling agent include diisocyanate, oxazoline, diepoxy compound, acid anhydride and the like, and 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 diisocyanate is not particularly limited,
For example, 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 are preferable, and hexamethylene diisocyanate is particularly preferable from the viewpoint of the hue of the produced resin, the reactivity at the time of adding the 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 occurs.

The addition is preferably 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 device or to a molten polyester prepolymer (for example, in a kneader). Is practical.

In this case, the aliphatic polyester has a number average molecular weight of 10,000 or more, which makes the polyester resin and the polyester resin composition have sufficient mechanical properties.

The cellulosic organic filler used in the present invention is generally widely used in the fields of synthetic resin and rubber. As these fillers, those which do not easily react with oxygen and water and which do not decompose during kneading and molding are preferably used. Examples of the filler include chaff, wood powder, waste paper powder and the like.

Of these cellulosic organic fillers,
The powder form has a diameter of 300 μm or less, preferably 1
Those having a diameter of 00 μm or less (more preferably 30 μm or less) are preferable. The fibrous material has a diameter of 1 to 300 μm (preferably 1 to 200 μm) and a length of 0.1 to 30 m.
m (preferably 0.1 to 10.0 mm) is desirable. Further, a flat plate-shaped product has a thickness of 150 μm or less (preferably 30 μm).
μm or less) is preferable. Of these fillers,
Particularly, flat plate-shaped (flake-shaped) and powdered ones are preferable.

The composition ratio (content ratio) of the cellulose-based organic filler in the polyester resin composition is 5 to 7
It is 0% by weight, preferably 5 to 65% by weight, and particularly preferably 10 to 50% by weight. When the composition ratio of the filler in the polyester resin composition containing a cellulosic organic filler exceeds 70% by weight, the impact resistance of the obtained sheet and container is significantly lowered, and only a sheet or container which is not suitable for practical use is obtained. I can't. On the other hand, if it is less than 5% by weight, the rigidity is not improved and the heat resistance is not improved.

The aliphatic polyester resin composition thus obtained has a temperature of 190 ° C. and a shear rate of 100 (sec).
^-1 ) has a melt viscosity of 1.0 × 10 ^{3 to} 1.0 × 10
⁶ poise. Preferably 5 × 10 ^{3 to} 5 × 10 ⁵ ,
Particularly preferably, it is 1.0 × 10 ^{4 to} 1.0 × 10 ⁵ poise. If it is less than 1.0 × 10 ³ poise, the fluidity is improved, but mechanical properties such as heat resistance (especially thermal stability of the sheet) and impact resistance are deteriorated, while if it exceeds 10 ⁶ poise, heat is generated. Extrudability deteriorates and a good quality sheet cannot be obtained.

The melt viscosity was measured with a nozzle diameter of 1.0.
mm, using a nozzle of L / D = 10, resin temperature 1
Shear rate 100 sec from the relational graph between shear rate and apparent viscosity measured by capillary rheometer at 90 ° C
The viscosity at ^-1 was determined.

To produce the polyester resin composition of the present invention, the object can be achieved by uniformly mixing the above-mentioned aliphatic polyester resin and the filler in a desired ratio. As a mixing method, using a mixer such as a single-screw or twin-screw extruder, a mixing roll, a kneader, a roll mill, a Banbury mixer and a continuous mixer gelation system that are usually used in the field of olefin polymers, etc. There is a method of kneading. Alternatively, a masterbatch (mixture) obtained by producing a high-concentration filler masterbatch such as polyester resin
And polyester resin may be mixed.

The polyester resin composition thus obtained may be used as it is, but depending on the purpose of use, it is generally used in the field of olefin polymers for oxygen, light (ultraviolet rays) and heat. The above-mentioned characteristics that the polyester resin composition of the present invention has additives such as a stabilizer, a flame retardant, a lubricant, a processability improver, a colorant, an antistatic agent, an electrical property improver or an adhesion improver ( You may add in the range which does not impair the effect.

The aliphatic polyester resin composition according to the present invention is formed into a sheet by various molding methods such as calendering method and T-die method. The resin temperature in this case is 100-27.
The temperature is 0 ° C, preferably 120 to 250 ° C, more preferably 150 to 220 ° C. If the temperature is lower than 100 ° C, the viscosity is too high to form a sheet, and if the temperature exceeds 270 ° C, the resin deteriorates, which is disadvantageous.

The microbial-degradable high-rigidity aliphatic polyester composition obtained by the present invention can improve heat resistance and rigidity while preserving microbial-degradability by incorporating a cellulosic filler, and is a packaging material. Alternatively, it can be used as a general-purpose plastic sheet. Further, since the sheet is suitable for vacuum forming and pressure forming, it is suitable as a material for molded articles such as containers and parts by such secondary thermoforming.

[0046]

EXAMPLES The present invention will be described below with reference to examples and comparative examples. The biodegradability is 10 cm x 20 cm, and each sheet is sandwiched between stainless steel molds equipped with a polyethylene net at the window to bury it in deep soil of 10 cm, and it is dug out after 12 months, and its degradability is evaluated. did. Also, a commercially available paperboard having the same thickness was simultaneously tested as a comparison. The evaluation of the following state A is preferable.

State A: When the aliphatic polyester sheet is more decomposed than paper and is in a tattered state with perforation of the sheet. State B: When the decomposition of the paper is more advanced than the aliphatic polyester sheet and the aliphatic polyester sheet is still firm.

The tensile properties were measured according to JIS K7113 and the calorific value of combustion was measured according to the calorimeter method of JIS M8814. The rigidity was measured in both directions MD and TD with an Olsen stiffness meter (ASTM D747), and the lower value was used as the measured value. The dirt impact impact strength was measured by ASTM D1709.

(Example 1) A 700-liter reactor was purged with nitrogen, and then 183 kg of 1,4-butanediol and 224 kg of succinic acid were charged. The temperature was raised in a nitrogen stream, and the esterification reaction by dehydration condensation was carried out for 3.5 hours at 192 to 220 ° C. for 3.5 hours, and then nitrogen was stopped for 3.5 hours under a reduced pressure of 20 to 2 mmHg. The sample collected had an acid value of 9.2 mg / g, a number average molecular weight (Mn) of 5,160, and a weight average molecular weight (Mw) of 10,67.
It was 0. Subsequently, 34 g of tetraisopropoxytitanium as a catalyst was added under a nitrogen stream under normal pressure. Raise the temperature to 15 ~ 0.2mmHg at 215 ~ 220 ℃
The deglycolization reaction was performed for 5.5 hours under reduced pressure. 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) is 339 when condensed water is removed.
It was kg.

5420 g 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, 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 continued for another 30 minutes. This reaction product was extruded into water with an extruder and cut into pellets with a cutter. 90 ° C
The yield of polyester (B1) after vacuum drying for 6 hours 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, the solvent is a solution of CF ₃ COONa in 5 mmol hexafluoroisopropyl alcohol, the concentration is 0.1% by weight, and the calibration curve is Showa Denko KK's PMMA standard sample Shodex Standard M-75.
I went there.

Next, 80 wt% of this polyester resin,
After blending a mixture with 20 wt% of chaff crushed to an average particle size of 12 μm with a Henschel mixer, a resin temperature of 18 was obtained using a twin-screw extruder of the same direction with a screw diameter of 50 m / m.
The mixture was kneaded and pelletized at 0 ° C. to obtain a polyester (B1) composition. The composition (B1) had a melt viscosity of 2.1 × 10 ⁴ poise at a temperature of 190 ° C. and a shear rate of 100 sec ⁻¹ .

<< Method and Conditions for Manufacturing Sheet Using Polyester (B1) Composition >> The polyester (B1) composition was mixed with a vent type extruder having a screw diameter of 40 mmφ and L / D = 32 at a resin temperature of 180 ° C. A sheet having a thickness of about 750 μm was manufactured by extruding with a T-die having a width of 350 mm (lip width 1.0 mm), and forming the sheet under the conditions of the first and second cooling roll temperatures of 60 ° C.

The sheet obtained by the above-mentioned molding is vacuum-formed (manufactured by Asano Laboratory, model name FLX-02 type, oven type double-sided infrared heating system), container (length: 140 mm, width:
140 mm, depth 45 mm) was created. Sheet molding,
There was no problem in vacuum forming, and no distortion occurred in the obtained container.

The MD and TD tensile rupture strength (JIS K-7113) of the obtained sheet, the rigidity (ASTM D-747) by the Olsen type stiffness meter, the dart impact impact strength (ASTM D 1709), the calorific value of combustion, The sheet formability and biodegradability were tested, and the evaluation results are shown in Table 1. In addition, the measurement of the notched Izod impact strength (JIS K-7110) at 23 degreeC used the sample which pressed the polyester (B1) composition at 190 degreeC.

(Example 2) The filling amount of crushed chaff was set to 30
It was carried out in the same manner as in Example 1 except that it was set to wt%. The melt viscosity was 2.8 × 10 ⁴ poise, and there was no problem in molding. The evaluation results of the obtained sheet and container are shown in Table 1.

Example 3 The same procedure as in Example 1 was carried out except that the filler was wood powder having an average particle size of 15 μm. The melt viscosity was 2.2 × 10 ⁴ poise, and there was no problem in molding. Table 1 shows the evaluation results of the obtained sheets and containers.

Example 4 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 stop the nitrogen, and under a reduced pressure of 20-2 mmHg 3.5.
The esterification reaction by dehydration condensation was performed over time.
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 (Mw).
Was 12,200. Subsequently, 20 g of tetraisopropoxytitanium 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, 1.70 kg of Irganox 1010 (manufactured by Ciba Geigy) as an antioxidant 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. 9
Polyester (B2) after vacuum drying at 0 ° C for 6 hours
The yield was 300 kg.

The obtained polyester (B2) was a slightly ivory-like 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.

Then, this polyester (B2) composition was treated in the same manner as in Example 1 with 80 wt% of the resin and an average particle diameter of 12 μm.
Pelletize a mixture of 20% by weight of No. chaff and a resin temperature of 200 ° C. to adjust the resin temperature at the time of sheet molding to 190
A sheet was manufactured under the same conditions as in Example 1 except that the temperature was changed to ° C. The melt viscosity was 2.9 × 10 ⁴ poise. Furthermore, a container of the same size was prepared by using the vacuum forming machine manufactured by Asano Laboratory Co., Ltd., which used the sheet in Example 1, but there was no problem in molding and no distortion occurred in the container.

(Example 5) After replacing a 700 L reactor with nitrogen, 200.2 kg (molar ratio 105) of 1,4-butanediol and 249.8 kg (molar ratio 10) of succinic acid were used.
0) and 2.8 kg of trimethylolpropane (molar ratio 1) were charged. After the temperature was raised under a nitrogen stream, the esterification reaction by dehydration condensation was carried out at a temperature of 190 to 220 ° C. for 4.5 hours, and then the nitrogen was stopped and the pressure was reduced to 20 to 4 mmHg for 5.5 hours. The sample collected is
The acid value is 10.4 mg / g and the number average molecular weight (Mn) is 4,
900, and the weight average molecular weight (Mw) was 10,000 (Mw / Mn = 2.0).

Subsequently, 45 g of titanium tetraisopropoxide as a catalyst (0.01 part per 100 parts of the polymer) was added under a nitrogen stream at atmospheric pressure. After raising the temperature, 15-1.3mm at 210-220 ° C
The deglycol reaction was performed under a reduced pressure of Hg for 8.0 hours. The sample collected had a number average molecular weight (Mn) of 16,9.
00, and the weight average molecular weight (Mw) was 90,300 (Mw / Mn = 5.4). This polyester (A
In 3), the theoretical yield was 367 kg excluding the theoretical amount of condensed water of 76.1 kg.

A reactor containing 367 kg of polyester (A3) was charged with 36 parts of Irganox 1010 as an antioxidant.
7g and 367g calcium stearate as lubricant
(0.5 parts), and then hexamethylene diisocyanate (3.67 kg, 1.0 part) to give 160-2.
The coupling reaction was carried out at 00 ° C for 2 hours. Then stirring was continued for another 30 minutes. The reaction mixture was extruded into water using an extruder and cut into pellets with a cutter. The yield of this polyester (B3) is about 350 kg.
Met.

This sample had Mn of 17,900 and Mw of 161,500 (Mw / Mn = 8.
5).

The obtained polyester (B3) was a slightly ivory white waxy crystal and had a melting point of 104.
° C, number average molecular weight (Mn) 17,900, weight average molecular weight (Mw) 161,500, MFR (190 ° C) 0.21 g / 10 minutes, temperature 190 ° C, shear rate 100 s
The melt viscosity at ec ^-1 was 2.0 x 10 ⁴ poise.

The procedure of Example 1 was repeated except that the polyester (B3) was used. Melt viscosity is 2.7 × 10 ⁴
It was a poise and there was no problem in molding. Table 1 shows the evaluation results of the obtained sheet and container.

(Comparative Example 1) The polyester (A1) was used as it was in the same manner as in Example 1. However, not only the pelletizing property using a twin-screw extruder was inferior, but also the strength was very weak and sheet forming was performed. I couldn't. Table 1 shows the evaluation results of the obtained sheets and containers.

[0069]

[Table 1]

[0070]

EFFECTS OF THE INVENTION A sheet formed from a composition of the present invention, which is a mixture of an aliphatic polyester resin and a cellulosic organic filler, has biodegradability when grown on soil or the like, and burns with heat even when incinerated. The amount is as low as about 1/2 that of polyolefin resins such as polypropylene and polyethylene. It is about the same as paper and has excellent tensile strength and rigidity impact strength. It is used for food container sheets, packaging sheets, general use. It is useful as a sheet and as a material for secondary molding.

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

Claims (5)

[Claims] 1. A high-molecular-weight filler comprising an aliphatic polyester mainly composed of glycol and an aliphatic dibasic acid or its acid derivative and having a number average molecular weight of at least 10,000, and a cellulose-based organic filler. Rigid aliphatic polyester resin composition. 2. A polyester resin composition containing 10 to 70% by weight of a cellulosic organic filler such as chaff and wood flour, and having a rigidity of 6,000 kg / cm ² or more. Highly rigid aliphatic polyester resin composition. 3. A temperature of 190 ° C., a shear rate of 100 sec ⁻¹
The high-rigidity aliphatic polyester resin composition according to claim 1 or 2, which has a melt viscosity of 1.0 x 10 ^{3 to} 1.0 x 10 ⁶ poise. 4. An aliphatic polyester resin composition molded article obtained by subjecting the aliphatic polyester resin composition sheet according to any one of claims 1 to 3 to heat molding such as vacuum molding and pressure molding. 5. The polyester resin composition according to claim 1, wherein the sheet has a rigidity of 7,000 kg / cm ² or more in both MD and TD directions and a tensile breaking strength of 150 k.
An aliphatic polyester resin composition sheet having a g / cm ² or more.