JPH08134196A - Aliphatic polyestercarbonate resin composition - Google Patents

Abstract

PURPOSE: To obtain the subject composition comprising a specific aliphatic polyestercarbonate, a phosphorus compound, etc., in a specific ratio, excellent in melt processability, detention stability, mechanical strength, etc., and useful for films, nonwoven fabrics, etc. CONSTITUTION: This composition comprises (A) 100 pts.wt. of an aliphatic polyestercarbonate produced by reacting a diarylcarbonate with a polyester oligomer synthesized from an aliphatic dibasic acid and an aliphatic dihydroxy compound and having a weight-average mol.wt. of >=120000, (B) 0.0005-0.01 pt.wt. of at least one phosphorus compound preferably selected from phosphoric acid, phosphorous acid and polyphosphoric acid, if necessary, (C) 0.05-1 pt.wt. of an antioxidant, (D) 0.05-0.5 pt.wt. of a lubricant such as a metal soap or an aliphatic hydrocarbon, and (E) an inorganic filler.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stable, colorless aliphatic polyester carbonate which has practically sufficient melt processability and enables injection molding, blow molding, extrusion molding and the like.

[0002]

2. Description of the Related Art Conventionally, as a polyester carbonate using an aliphatic compound, a polyester carbonate using an alicyclic compound or a polyester carbonate using an aromatic compound and an aliphatic compound usually has a high melting point or a high melting point. It is known that it can be used as a molded product because it exhibits a glass transition point. However, they are generally not biodegradable. Biodegradable polymer (hereinafter simply referred to as biodegradable polymer)
The aliphatic polyester carbonates classified by the above are aliphatic polyester carbonates prepared by a ring-opening polymerization method using a cyclic monomer. These are composed of a hydroxycarboxylic acid unit and an aliphatic carbonate unit as constituent elements, and are biocompatible and used in the medical field, but since they are hydrolyzable, they are used as a film, sheet or molded body. Limited to use.

On the other hand, it is known to produce a polyester carbonate from an aliphatic dibasic acid, an aliphatic dihydroxy compound and a diaryl carbonate, but an aliphatic polyester containing this aliphatic dibasic acid and an aliphatic dihydroxy compound as constituents. Carbonates generally have a low melting point and rubber-like properties, and although various proposals have been made for use as adhesives, sealing agents, coating coating agents, and polymer alloys with other resins, their main applications are However, it is to be used as a liquid low molecular weight material for a urethane raw material, and an example in which it is formed into a film or fiber and put into practical use has not yet been found. Further, utilization as a biodegradable polymer has not been known so far. As a raw material for the conventional aliphatic polyester carbonate, a relatively long-chain dibasic acid such as adipic acid and a diol having 5 or more carbon atoms are usually selected. For example, in JP-A-60-13811, A method for producing an aliphatic polyester carbonate from polyester diol or polyether diol and diphenyl carbonate is disclosed. However, when a diol compound having a carbon number of 4 or less is used as a diol component, a side reaction such as a ring closure reaction of the diol component itself or the formation of a cyclic carbonate occurs during the reaction to industrially produce a high molecular weight aliphatic polyester carbonate. The reality is that we cannot obtain it.

[0004]

DISCLOSURE OF THE INVENTION The inventors of the present invention have diligently studied to solve the above-mentioned problems, and first disclosed in Japanese Patent Application No. 5-20060.
No. 2, it was proposed that the resulting high molecular weight aliphatic polyester carbonate could be used as a biodegradable polymer. Needless to say, these high molecular weight aliphatic polyester carbonates can be melt-molded by themselves, but when they are molded by a molding machine, there are problems such as an increase in the degree of coloring and a decrease in the molecular weight.
The present invention has solved the above problems and provides an aliphatic polyester carbonate resin composition which is not colored and has improved retention stability in a molding machine and is easy to mold.

[0005]

The aliphatic polyester carbonate composition of the present invention, which is stable and has no coloration during melt molding, contains a diaryl carbonate in a polyester oligomer synthesized from an aliphatic dibasic acid and an aliphatic dihydroxy compound. 100 parts by weight of the aliphatic polyester carbonate (A) obtained by the reaction is mixed with the phosphorus compound (B)
It can be obtained by mixing 0.0005 to 0.01 parts by weight, if necessary, an antioxidant (C), a lubricant (D) and an inorganic filler (E), and melt-kneading.

The production of the aliphatic polyester carbonate for obtaining the resin composition of the present invention is carried out in two steps in order to avoid decomposition of the carbonate bond.

That is, the first step is a step of reacting an aliphatic dihydroxy compound with an aliphatic dibasic acid to produce a polyester oligomer. In the reaction of the aliphatic dihydroxy compound with the aliphatic dibasic acid, the aliphatic dihydroxy compound is used in a stoichiometric excess. Specifically, the aliphatic dihydroxy compound is used in a range of 1.05 to 2.00 with respect to 1 aliphatic dibasic acid in a molar ratio. At a temperature of 100-250 ° C, preferably 150-220 ° C,
By-product water or alcohol and excess aliphatic dihydroxy compound are removed. The first step is finally performed under reduced pressure because it is necessary to remove water or alcohol by-produced by the reaction and excess dihydroxy compound. The pressure is selected so that the above-mentioned object can be achieved, and it is preferable that the pressure is reduced to 300 mmHg or less for the purpose of promoting the reaction. The number average molecular weight of the polyester oligomer is preferably in the range of 500 to 5000. If it is higher than this molecular weight, the amount of carbonate bonds in the polymer obtained in the second step described below will be small and the biodegradability will be reduced. . Also, the molecular weight is 50
When it is 0 or less, the melting point of the polymer is lowered. The molecular weight (terminal hydroxyl value) is adjusted by adjusting the amount of the aliphatic dihydroxy compound distilled.

The second step is a step of reacting the polyester oligomer obtained in the first step with a diaryl carbonate to obtain an aliphatic polyester carbonate. In this step, phenol by-produced by the reaction is removed. The reaction temperature is usually 150 to 250 ° C., preferably 20.
It is 0-220 degreeC. If the reaction temperature is high, the polymerization will be faster,
The polymer may be colored, which is not preferable. The reaction is
Adjust the degree of decompression gradually if necessary, and finally 3 mm
It is preferable to reduce the pressure to Hg or less. In order to obtain the resin composition of the present invention, the amount of the diaryl carbonate used is within a range of 0.45 to 0.55 times the molar amount of the terminal hydroxyl group of the aliphatic polyester oligomer.
A more preferable range is 0.49 to 0.51 times the molar amount. The amount of carbonate bonds in the obtained polymer is preferably 1.8 to 33 mol%, more preferably 3 to 25 mol%. When the amount of carbonate bond increases, the biodegradability improves, but the melting point decreases, so it is necessary to control it according to the application. The molecular weight of the aliphatic polyester carbonate used in the resin composition of the present invention is 100,000 or more, preferably 120,000 or more in terms of weight average molecular weight in terms of styrene by GPC, in order to obtain physical properties that can withstand use, and below that. Strength is reduced. The molecular weight can be controlled by the reaction time, but it can also be controlled by adding a monofunctional compound as a terminal stopper. As the terminal terminator, long-chain aliphatic carboxylic acids and their esters, high-boiling point phenol derivatives and their carbonic acid diesters, etc. can be used.

The oligomer used in this step is not limited to one kind, and it is also possible to manufacture two or more kinds of polyester oligomers having different raw materials and mix them to manufacture a block copolymer. is there.

Examples of the aliphatic dihydroxy compound used for producing the aliphatic polyester carbonate used in the resin composition of the present invention include ethylene glycol, trimethylene glycol, propylene glycol, 1,3 and 1,4-butanediol. , Pentanediol, hexanediol, neopentyl glycol, cyclohexanediol and the like.

Examples of the aliphatic dibasic acid used in the production of the aliphatic polyester carbonate used in the resin composition of the present invention include succinic acid, malonic acid, glutaric acid, adipic acid and azelaic acid. Illustrative, each ester or acid anhydride can also be used.
These aliphatic dihydroxy compounds and aliphatic dibasic acids can be used alone or as a mixture and can be combined as desired, but they have appropriate biodegradability and practical heat resistance. Therefore, those having a high melting point are preferable. Therefore, succinic acid is used as the dibasic acid.
The aliphatic dihydroxy compound preferably contains 1,4-butanediol in an amount of 60 mol% or more, and particularly preferably in a combination of 80 mol% or more.

Specific examples of the diaryl carbonate used in the production of the aliphatic polyester carbonate used in the resin composition of the present invention include diphenyl carbonate, ditolyl carbonate, bis (chlorophenyl) carbonate and m-cresyl carbonate. And so on. Of these diaryl carbonates, diphenyl carbonate is particularly preferable.

Known catalysts are used in the production of the aliphatic polyester carbonate used in the resin composition of the present invention. Examples thereof include alkali metal compounds, alkaline earth metal compounds, zinc compounds, tin compounds, IVB group compounds such as titanium, zirconium and hafnium. In the present invention, since the catalyst used remains in the polymer after the polymerization, if used excessively, the thermal stability of the polymer is impaired, and if too small, it takes a long time to complete the oligomer production and the polymerization reaction, and coloring It is not preferable because it causes Therefore, 10 to 100 ppm relative to the polymer
It is preferable to use it in such a range that Regarding the method of adding the catalyst, there are a method of adding from the above-mentioned first step (step of obtaining an oligomer), and a method of adding to each of the first step and the second step (step of obtaining a polyester carbonate). Either may be used.

In order to prepare the aliphatic polyester carbonate resin composition of the present invention which is stable and has no coloration during melt molding, the following phosphorus compounds are added to the aliphatic polyester carbonate (A) obtained by the above method. It is achieved by Examples of the phosphorus compound (B) include tris (2,4-di-t-butylphenyl) phosphite, tris (nonylphenyl) phosphite, trilaurylphosphite, triphenylphosphite, distearylpentaerythritol diphosphite. Phosphite, bis (2,4-di-t-butylphenyl) pentaerythritol diphosphite, bis (nonylphenyl) pentaerythritol diphosphite, 4,4′-butylidene bis (3-methyl-6-t-butylphenyl) - di - tridecyl phosphite), 4,4'-isopropylidenediphenol alkyl (C ₁₂ -C ₁₅₎ phosphite such as phosphites, further phosphoric acid, phosphorous acid and trimethyl phosphate, tributyl phosphate, dibutyl Phosphoric acid such as butyl phosphate, phosphorous acid Inorganic phosphorus compounds such as esters and polyphosphoric acid can be used. Particularly, phosphoric acid, phosphorous acid and polyphosphoric acid can be preferably used. Polyphosphoric acid is particularly preferable because phosphoric acid is slightly inferior to phosphorous acid and polyphosphoric acid in stabilizing effect at high temperature, and phosphorous acid is deliquescent and has a problem in operation.

In the present invention, the addition of a small amount of the phosphorus compound (B) has an excellent stabilizing effect. It is presumed that this is because the phosphorus compound (B) captures and deactivates the catalyst added at the time of polymerization and prevents a decrease in the molecular weight in the molten state. Up to now, no example of adding a phosphorus compound to an aliphatic polyester carbonate has been found. So far, JP-A-6-80872 discloses the use of a phosphorus-based compound as an anti-coloring agent for an aliphatic polyester urethane. However, in this publication, the purpose is to prevent coloration due to the urethane bond, and a very large amount of phosphorus compound is used. When the same amount of phosphorus compound is added, the thermal stability is impaired, and there is a problem of remarkable coloring in the high temperature molten state.

The amount of the phosphorus compound (B) added is 0.0005 to 0.01 part by weight based on 100 parts by weight of the aliphatic polyester carbonate (A). If it is less than 0.0005 parts by weight, the effect at the time of heat molding is too small, while 0.0
If it is more than 1 part by weight, the thermal stability is rather deteriorated. Especially when using phosphoric acid, phosphorous acid, or polyphosphoric acid,
Effective even with a very small amount used, preferably 0.00
It is from 05 to 0.005 parts by weight.

An antioxidant may be added to the composition composed of the aliphatic polyester carbonate (A) and the phosphorus compound. Examples of the hindered phenol stabilizer (C) include triethylene glycol-bis- "3".
-(3-t-butyl-5-methyl-4-hydroxyphenyl) propionate ", 1,6-hexanediol-
Bis- "3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate", tetrakis "3-"
(3,5-di-t-butyl-4-hydroxyphenyl)
Propionate "methane, octadecyl" 3- (3,5
-Di-t-butyl-4hydroxyphenyl) propionate, N, N'-bis "3- (3,5-di-t-butyl-4-hydroxyphenyl) propionyl" hydrazine and the like can be used. The amount of the phenolic stabilizer used is 0.05 to 1 part by weight based on 100 parts by weight of the aliphatic polyester carbonate. If the amount is less than 0.05 parts by weight, the effect is too small, and if the amount is more than 1 part by weight, a coloring problem occurs.

A lubricant (D) may be further added to the composition of the present invention, which comprises the aliphatic polyester carbonate (A), the phosphorus compound (B) and, if necessary, the antioxidant (C). Lubricants that can be used in the present invention are, for example,
Metal soap lubricants such as calcium stearate, zinc stearate and tin stearate, paraffins having 16 or more carbon atoms, polyolefin waxes and partial oxides thereof, coconut oil, soybean oil, rapeseed oil, rice bran wax, and purified products. And amides of higher fatty acids, beeswax and the like. The amount of the lubricant (D) used is 0.05 to 100 parts by weight of the aliphatic polyester carbonate (A).
0.5 parts by weight. If the amount is less than 0.05 parts by weight, there is no effect, and if the amount is more than 0.5 parts by weight, bleeding on the surface of the molded product is not preferable. The lubricant (D) in the present invention has an internal lubricity that reduces friction between polymers and an external lubricity that improves the sliding between the polymer and the metal surface, and prevents the surface roughness of the molded article to have a good appearance. There is an effect to give.

Further, the addition of the inorganic filler to the aliphatic polyester carbonate used in the present invention also lowers the melt fluidity of the composition, resulting in an increase in molding processing temperature and an excessive shear stress. , With the result that the thermal stability of the composition is impaired. By adding an inorganic filler (E) and a lubricant (D) to a composition comprising the aliphatic polyester carbonate (A) of the present invention, a phosphorus compound (B), and optionally an antioxidant (C), a composition Melt fluidity without impairing the thermal stability of the product,
In addition to the effect of adjusting the crystallization rate and increasing the strength of the molded product, the effect of lowering the calorific value of combustion when the composition of the present invention is incinerated is exhibited.

The inorganic filler usable in the present invention is, for example, aluminum oxide, magnesium oxide, magnesium hydroxide, zinc oxide, lead oxide, titanium oxide, iron oxide, antimony oxide, zirconium oxide, magnesium carbonate,
Examples include calcium carbonate, barium carbonate, aluminum sulfate, asbestos, mica, talc, glass fiber, glass beads, clay, silica and dolomite. Among such inorganic fillers, if they are powdery, the particle diameter is 30 μm or less, preferably 10 μm.
The following is used: As a fibrous material, the diameter is 1 to 1
00 μm, preferably 1 to 80 μm, with a length of 0.
It is 1 to 10 mm, more preferably 0.1 to 5 mm. In addition, as flakes, 30 μm or less,
It is preferably 10 μm or less. The mixing ratio of the inorganic filler to the aliphatic polyester carbonate is 100 parts by weight of the aliphatic polyester carbonate,
It is used in an amount of 0.1 to 70 parts by weight, preferably 10 to 60 parts by weight. When the mixing ratio of the inorganic filler to the aliphatic polyester carbonate is 70 parts by weight or more, a resin composition having practical strength cannot be obtained. If the amount is 10 parts by weight or less, a composition having a combustion heat of 5000 Kcal / Kg or less cannot be obtained, and the effect of improving rigidity and heat resistance is small.

Aliphatic polyester carbonate of the present invention
The resin composition has a resin temperature of 190 ° C and a die hole diameter of 1.0 mm.
φ, L / D = 10, 60 Kg / cm²For weighted measurement conditions
In, melt viscosity measured using a flow tester,
1.0 x 10³~ 1.0 × 10^Fivein the range of poise
More preferably 3.0 × 10³~ 5.0 x 10 ^Four
Those in the poise range are used. 3.0 x 10³
Below poise, the fluidity is good and molding process
Advantageous but mechanical strength such as impact strength, tensile elongation
Is inferior, 5.0 × 10^FourMoldability at poise and above
Is reduced.

The aliphatic polyester carbonate composition of the present invention contains a phosphorus compound (B), an antioxidant (C) and, if necessary, an aliphatic polyester carbonate (A) when it is produced in a reactor. It can be obtained by mixing the lubricant (D) and the inorganic filler (E) at a temperature of 150 to 250 ° C. simultaneously or sequentially. Alternatively, after the aliphatic polyester carbonate (A) is discharged from the reactor and pelletized, the above-mentioned additive or the masterbatch containing the above-mentioned additive and the above-mentioned pellet are melt-kneaded by an extruder and pelletized again. You can also

[0023]

EXAMPLES The present invention will be described in more detail with reference to examples. The oligomers and polymers obtained were evaluated by the following methods.

The melting point was measured using a DSC manufactured by Seiko Denshi KK.

The molecular weight was measured by GPC manufactured by Showa Denko using chloroform as a solvent.

Carbonate bond content is JEOL Ltd.
It was calculated as the ratio (% by weight) of the carbonate unit to the total of the dicarboxylic acid ester unit and the carbonate unit by the ¹³ CNMR measurement using the NMR produced.

The hydroxyl value and acid value of the polyester oligomer were measured according to JIS K-1557. From the measured hydroxyl value, the amount (mol) of terminal hydroxyl groups per unit weight was determined, and ½ of the amount was used as the theoretical amount of diaryl carbonate.

For evaluation of biodegradability, a molded film (thickness 150 μm) was cut into a strip of 20 × 90 mm and embedded in a depth of 5 cm from the soil surface, and a soil embedding test was conducted. After 20 weeks, the sample in which a change such as a hole was observed due to decomposition was observed was A, the sample in which a slight weight change was observed was B, and the sample in which no change was observed was C.

The calorific value of combustion was measured according to the calorimeter method of JIS M-8814.

Example 1 A reactor having an internal volume of 50 L equipped with a stirrer, a fractionating condenser, a thermometer, and a gas introduction tube was charged with 15.6 kg (1) of succinic acid.
32 mol), 1,4-butanediol 17.9 kg (1
99 mol) and 0.6 g of zirconium acetylacetonate were charged, and the temperature was 150 to 220 in a nitrogen atmosphere.
The reaction was carried out at 0 ° C for 2 hours to distill off water. Subsequently, the pressure was finally reduced to 3 mmHg or less, and water and 1,4-butanediol were further distilled off to adjust the amount of unreacted 1,4-butanediol to 0.5%. The terminal hydroxyl value of the obtained oligomer was 102 KOHmg / g, and the acid value was 0.5 KOHmg.
/ G.

Subsequently, 20.1 kg of the prepolymer obtained above was charged into a reaction kettle (internal volume 50 L, made of SUS316) equipped with a stirrer and a fractionating condenser, and 3.94 kg (18.4 mol) of diphenyl carbonate was charged. Was added. 1.0 g of zinc acetate was added, and the temperature was 210-220 ° C.
Finally, the pressure was reduced to 0.5 mmHg and the reaction was carried out for 4 hours.

The obtained high molecular weight product has a melting point of 104 ° C.,
It had a weight average molecular weight of 192000 as measured by GPC, had 11.1% of carbonate bonds as a polycarbonate component by ¹³ CNMR measurement, and was not colored.

Polyester carbonate 100 obtained
0.003 parts by weight of polyphosphoric acid was mixed with 1 part by weight, and the mixture was melt-kneaded with a twin-screw extruder at a resin temperature of 190 ° C. and pelletized.

Also, using a melt indexer manufactured by Toyo Seiki Co., Ltd., the pellets obtained above were treated with a water content of 1000 p.
After adjusting to pm, the melt viscosity was measured after holding in a heating cylinder at a temperature of 190 ° C. for 5 minutes and 30 minutes. The melt viscosities were 9800 poise and 9600 poise, respectively, and almost no decrease in melt viscosity (reduction in molecular weight) due to retention was observed. In addition, the obtained pellet is
After vacuum drying for 6 hours to reduce the water content to 1000 ppm or less, an injection molding machine (IS55EPN manufactured by Toshiba Machine) was used to obtain a molded body for measuring mechanical strength at a resin temperature of 190 ° C. and a mold temperature of 40 ° C. The mechanical strength, heat of combustion, and biodegradability were measured, and the evaluation results are shown in Table 1.

Comparative Example 1 Polyester carbonate obtained by the same procedure as in Example 1 was extruded and pelletized in the same manner as in Example 1 without adding any additive. Further, using a melt indexer, the pellets adjusted to have a water content of 1000 ppm were held in a heating cylinder at a temperature of 190 ° C. for 5 minutes and 30 minutes, and then the melt viscosity was measured. The melt viscosities were 8500 poise and 6700 poise, respectively, and an increase in coloring degree and a decrease in melt viscosity due to retention were observed. The molded body was evaluated in the same manner as in Example 1. Table 1 shows the evaluation results.

Example 2 100 parts by weight of polyester carbonate obtained by the same procedure as in Example 1 was added with 0.003 parts by weight of polyphosphoric acid and tetrakis "3- (3,5-di-t-butyl-4-hydroxy). Phenyl) propionate ”methane (trade name: Irganox 1010, manufactured by Ciba Geigy) is 0.1 part by weight, calcium stearate is 0.15 part by weight as a lubricant, and talc 20 having an average particle size of 0.5 μm is an inorganic filler.
Parts by weight were added, and the mixture was melt-kneaded at a resin temperature of 190 ° C. with a twin-screw extruder and pelletized. The melt viscosity of the resulting pellets was 10200 poise at 190 ° C. Also, using a melt indexer, the water content is 1000 ppm
The melt viscosity of the pellets prepared as described above was held in a heating cylinder at a temperature of 190 ° C. for 5 minutes and 30 minutes, and the melt viscosity was hardly changed. Example 1
The molded body was evaluated in the same manner as in. Table 1 shows the evaluation results.

Example 3 In the same reactor as in Example 1, 13.3 kg of succinic acid (11
3 mol), 1.5 kg of adipic acid (10.3 mol),
1,4-Butanediol (17.3 Kg, 192 mol) and zirconium acetylacetonate (0.6 g) were charged, and the mixture was reacted under a nitrogen atmosphere at a temperature of 150 to 220 ° C for 2 hours to distill water. Subsequently, the pressure was finally reduced to 3 mmHg or less, and water and 1,4-butanediol were further distilled off to make the amount of unreacted 1,4-butanediol 0.4%. The terminal hydroxyl value of the obtained oligomer is 102 KOH.
The acid value was 0.5 KOH mg / g.

Subsequently, 20.1 kg of the prepolymer obtained was charged in the same reaction kettle as in Example 1, and 3.94 kg (18.4 mol) of diphenyl carbonate was added. 0.8 g of zinc acetate was added, and finally the pressure was reduced to 0.5 mmHg at a temperature of 210 to 220 ° C. and the reaction was carried out for 4 hours. The resulting high molecular weight body, colorization, melting point 96 ° C., a weight average molecular weight by GPC measurement is 201,000, ¹³ C
11.1 as a polycarbonate component by NMR measurement
It had a% carbonate bond.

Polyester carbonate 100 obtained
To the parts by weight, 0.006 parts by weight of polyphosphoric acid and 0.10 parts by weight of Irganox 1010 were added, and the mixture was melt-kneaded at a resin temperature of 190 ° C. by a twin-screw extruder and pelletized in the same manner as in Example 1. Using a kusa, water content 1000pp
The pellets adjusted to m were held in a heating cylinder at a temperature of 190 ° C. for 5 minutes and 30 minutes, and then the melt viscosity was measured. The melt viscosities are 9400 poise and 9300, respectively.
It was a poise, and almost no change in melt viscosity due to retention was observed. The molded body was evaluated in the same manner as in Example 1. Table 1 shows the evaluation results.

Example 4 100 parts by weight of polyester carbonate obtained by the same procedure as in Example 3, 0.003 parts by weight of polyphosphoric acid, 0.1 parts by weight of Irganox 1010, and 0.15 parts by weight of calcium stearate as a lubricant. And 20 parts by weight of calcium carbonate having an average particle size of 1 μm as an inorganic filler, were melt-kneaded by a twin-screw extruder at a resin temperature of 190 ° C. and pelletized as in Example 1. The melt viscosity of the resin composition was 9900 poise at 190 ° C. Also, the melt viscosity was measured after holding the pellets adjusted to a water content of 1000 ppm in a heating cylinder at a temperature of 190 ° C. for 5 minutes and 30 minutes using a melt indexer. I couldn't do it. The molded body was evaluated in the same manner as in Example 1. Table 1 shows the evaluation results.

Comparative Example 2 100 parts by weight of polyester carbonate obtained by the same procedure as in Example 1 was mixed with 0.02 part by weight of polyphosphoric acid, and a twin screw extruder was used at a resin temperature of 190 ° C. as in Example 1. Was melt-kneaded and pelletized. Also, using a melt indexer, the pellets adjusted to a water content of 1000 ppm were placed in a heating cylinder at a temperature of 190 ° C. for 5 minutes and 3 minutes.
The melt viscosity was measured after holding for 0 minutes. The melt viscosities are 8200 poise and 6300 poise, respectively,
An increase in the coloring degree and a decrease in the melt viscosity due to the retention were observed.
The molded body was evaluated in the same manner as in Example 1. Table 1 shows the evaluation results.

[0042]

According to the present invention, an aliphatic polyester carbonate resin composition having improved residence stability in a molding machine, excellent mechanical strength and moldability, and biodegradability can be easily obtained. This resin composition can be used as a film, a sheet, a blow molded product, a foam, a filament, a net, a laminate, a non-woven fabric, or the like, or as a medical material as a substitute for a conventional general-purpose resin.

[0043]

[Table 1]

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Mitsuru Nakamura 22 Wadai, Tsukuba City, Ibaraki Mitsubishi Gas Chemical Co., Ltd.

Claims (5)

[Claims] 1. A polyester oligomer synthesized from an aliphatic dibasic acid and an aliphatic dihydroxy compound is reacted with a diaryl carbonate to obtain 100 parts by weight of an aliphatic polyester carbonate (A) having a weight average molecular weight of 120,000 or more. , Phosphorus compounds (B) 0.00
A stable aliphatic polyestercarbonate resin composition comprising 05 to 0.01 parts by weight. 2. The resin composition according to claim 1, wherein the phosphorus compound is at least one selected from phosphoric acid, phosphorous acid, and polyphosphoric acid. 3. The resin composition according to claim 1, further comprising 0.05 to 1 part by weight of the antioxidant (C). 4. The resin according to claim 1, which contains 0.05 to 0.5 part by weight of at least one lubricant (D) selected from metal soap, aliphatic hydrocarbon, higher fatty acid, fatty acid amide and fatty acid ester. Composition. 5. The resin composition according to claim 1, which contains a lubricant (D) and an inorganic filler (E).