JP2003327677A - Biodegradable resin and film - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a biodegradable aliphatic polyester resin which simultaneously meets flexibility, tensile strength, elongation, tear strength, biodegradability, and the like, and to prepare a film obtained by molding the same. <P>SOLUTION: The biodegradable resin is obtained by copolymerizing an aliphatic dicarboxylic acid represented by formula (1) (wherein R<SP>1</SP>is a direct bond or a 1-12C divalent aliphatic group), an aliphatic glycol represented by the formula (2): HO-R<SP>2</SP>-OH (wherein R<SP>2</SP>is a 2-4C divalent aliphatic group), a saturated monocyclic aliphatic diol represented by the formula (3): HO-CH<SB>2</SB>-R<SP>3</SP>-CH<SB>2</SB>-OH (wherein R<SP>3</SP>is a monocyclic saturated hydrocarbon group), and optionally a hydroxy acid or its corresponding cyclic ester, and the film is obtained by molding this biodegradable resin. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a saturated monocyclic aliphatic diol having a monocyclic saturated hydrocarbon group such as cyclohexanedimethanol to an aliphatic polyester resin such as polybutylene succinate and polyethylene succinate. The present invention relates to a flexible biodegradable resin characterized by comprising a polymerized polyester resin and a film formed by molding the same.

[0002]

2. Description of the Prior Art Synthetic polymers such as polyolefins and aromatic polyesters are used in large amounts as raw materials indispensable for daily life. As the number of wastes increases, the environmental problems caused by those wastes become apparent. Also, films used in agriculture and forestry have mud and soil attached to the films after use, and it takes time to collect and process them, so leave them in the mountains or plow in the soil of fields. There is a need for biodegradable resins that can be crushed or landfilled. In particular, the use of a biodegradable polymer has been attracting attention because the treatment of the film after use has become a problem even in the agricultural mulch film. Polylactic acid and aliphatic polyester resins have been investigated for use in these applications. Among them, polybutylene succinate and polyethylene succinate produced from succinic acid or a derivative thereof and butanediol or ethylene glycol have excellent biodegradability and excellent melting point and mechanical strength. ing.

However, polybutylene succinate and polyethylene succinate alone cannot provide practically sufficient flexibility, tensile strength, elongation and biodegradation rate as an agricultural film. In particular, for use in agricultural mulch film, it is necessary to withstand the automatic spreading work that accompanies the mechanization of agricultural work. The automatic spreading is a working method in which a series of works of plowing, furrowing, and stretching (spreading) of agricultural mulch film are performed mechanically by an agricultural machine such as a tractor. In this automatic spreading operation, strong tension acts on the agricultural mulch film to be spread, and the expanded mulch film may come into contact with pebbles or the like in the expanded state. Therefore, a film made of a polylactic acid resin that is hard and easy to tear or a film made of an aliphatic polyester resin is torn or torn due to the tension at the time of automatic expansion and contact with small stones. Therefore, copolymerization with various polyhydric alcohols, hydroxy acids and the like and blending with other polymers have been investigated. JP-A-7-109
No. 341 discloses a compound having at least one isocyanate group and at least one masked isocyanate group in one molecule of an aliphatic diol containing 1,4-cyclohexanedimethanol and a dicarboxylic acid as a method for producing a high molecular weight aliphatic polyester. , 0.5 to 10 parts by weight are reacted to produce a high molecular weight polyester having a weight average molecular weight of 50,000 or more.
However, in the resin disclosed in this publication, only 1,4-cyclohexanedimethanol is mentioned as one of the options for the diol component, and 1,4-cyclohexanedimethanol is added at a specific ratio. The degree of improvement in mechanical strength when included as an essential component of the copolymerizable monomer that constitutes the copolymer is not particularly disclosed, and tear resistance and rupture when the resin is processed into an agricultural mulch film. No mention is made that the point elongation is significantly improved. Further, according to the method described in the patent publication, there is no high molecular weight step (second step) for performing a deglycolization reaction when producing the resin of the present invention, and high molecular weight is performed using a polyisocyanate compound. ing. Therefore, the resin described in the above publication necessarily contains a urethane bond derived from the polyisocyanate compound. When the urethane bond derived from the polyisocyanate compound is present in the polymer chain, a highly toxic diamine is generated during the decomposition process, which may accumulate in the soil.
Not preferable. Further, JP-A-9-235360 describes an agricultural mulch film obtained by copolymerizing a hydroxy polyester with a fatty polyester resin, and 1,4-cyclohexanedimethanol is one of the diol components. However, in this publication,
Degree of improvement in mechanical strength when 1,4-cyclohexanedimethanol was included as an essential component of the comonomer forming the copolymer in a specific ratio, and tear resistance when processed into agricultural mulch film That is, there is no description that the strength in the machine direction (MD direction) or the elongation at break is remarkably improved. Further, the present applicants have already improved the mechanical strength of an aliphatic polyester resin by copolymerizing a hydroxy polyester with a hydroxy acid in JP-A-8-311181 and the like. In the above, 1,4-cyclohexanedimethanol is exemplified as one of them in the aliphatic diol as a component, but similar to the above two publications,
Degree of improvement in mechanical strength when 1,4-cyclohexanedimethanol is included as an essential component of the comonomer forming a copolymer in a specific ratio, and the longitudinal direction of the film when processed into an agricultural mulch film No mention is made of any improvement in strength (MD direction) or elongation at break significantly. In the case of a film made of a resin using only an ordinary divalent aliphatic diol as a general diol component disclosed in this publication, the easiness of tearing in the MD direction does not withstand automatic expansion. There has been a demand for an improved biodegradable resin and a film comprising the same.

[0004]

Agricultural mulch film is used in large quantities, and therefore it is not easy to dispose of it. In particular, it is difficult to use a machine to collect a film having a hole in it because mud adheres after use, and a great deal of labor is required. Therefore, the application of a film made of a biodegradable resin that can be plowed into the soil after use is increasing. However, the current biodegradable mulch film does not fully satisfy the flexibility, tensile strength, and elongation, and in particular, the tear strength cannot withstand automatic expansion.
As described above, the agricultural mulch film made of the biodegradable resin has a problem in performance as compared with the agricultural mulch film made of the non-biodegradable resin. The present invention has been made to solve the above-mentioned problems, and supplies a biodegradable resin that simultaneously satisfies flexibility, tensile strength, elongation, tear strength, biodegradability, etc. by using a specific constituent monomer. The purpose is to provide a film made of the resin.

[0005]

The present inventors have completed the present invention as a result of intensive studies to solve the above problems. That is, according to the first aspect of the present invention, the general formula (1)

[Chemical 4] (In the formula, R ¹ represents a direct bond or a divalent aliphatic group having 1 to 12 carbon atoms) and an aliphatic dicarboxylic acid represented by the general formula (2)

[Chemical 5] (In the formula, R ² represents a divalent aliphatic group having 2 to 4 carbon atoms), and an aliphatic glycol represented by the general formula (3)

[Chemical 6] It is obtained by copolymerizing a saturated monocyclic aliphatic diol represented by the formula (wherein R ³ represents a monocyclic saturated hydrocarbon group), and optionally a hydroxy acid or a cyclic ester corresponding thereto. A biodegradable resin is provided. The second aspect of the present invention also provides the first biodegradable resin of the present invention, which comprises a hydroxy acid or a cyclic ester corresponding thereto. According to the third aspect of the present invention, R ¹ and R ²
Is an alkylene group represented by (CH ₂ ) ₂ or R
¹ is (CH ₂ ) ₂ and R ² is an alkylene group represented by (CH ₂ ) ₄ , or R ¹ is (CH ₂ ) ₂ and R ² is represented by (CH ₂ ) _6. A first or second biodegradable resin of the present invention, which is an alkylene group, is provided. According to a fourth aspect of the present invention, there is provided the biodegradable resin according to any one of the first to third aspects of the present invention, wherein R ³ is a cyclohexane ring. According to a fifth aspect of the present invention, there is provided the biodegradable resin according to any one of the first to fourth aspects of the present invention, wherein the cyclic ester corresponding to the hydroxy acid is caprolactone. According to the sixth aspect of the present invention, the content of the saturated monocyclic aliphatic diol represented by the general formula (3) is 0 in molar ratio with respect to the aliphatic dicarboxylic acid represented by the general formula (1). .0005-0.3
A biodegradable resin according to any one of the first to fifth aspects of the present invention is provided, which is 0. According to a seventh aspect of the present invention, there is provided a film formed by molding the biodegradable resin according to any one of the first to sixth aspects of the present invention. Also, according to the eighth aspect of the present invention, there is provided the seventh film of the present invention, wherein the film is an agricultural mulch film.

The biodegradable resin of the present invention comprises an aliphatic dicarboxylic acid represented by the general formula (1), an aliphatic glycol represented by the general formula (2) and the general formula (3).
It can be obtained by polycondensing a saturated monocyclic aliphatic diol represented by and a hydroxy acid or a cyclic ester thereof (eg, ε-caprolactone, which is abbreviated as caprolactone) which is optionally used. As the aliphatic dicarboxylic acid, succinic acid is most preferably used from the viewpoint of the physical properties of the resulting copolymer. Specific examples of the aliphatic glycol represented by the general formula (2) include ethylene glycol, 1,4-butanediol, 1,3-propanediol, 1,5-pentanediol, and 1,6-hexanediol. Can be mentioned. Ethylene glycol and 1,4-butanediol are most preferable from the viewpoint of the physical properties of the obtained copolymer, particularly biodegradability and heat resistance. Specific examples of the saturated monocyclic aliphatic diol represented by the general formula (3) include 1,4-cyclohexanediol and 1,4-cyclohexanedimethanol having a substituent on the ring, but are not limited thereto. It is not something that will be done. 1,4-Cyclohexanedimethanol is preferable from the viewpoint of availability of raw materials. The hydroxy acid or the corresponding cyclic ester is an aliphatic oxycarboxylic acid or the corresponding cyclic ester. Specific examples of the former include lactic acid, glycolic acid, hydroxypivalic acid, hydroxycaproic acid (2-hydroxy-n-butyric acid, 2-hydroxycaproic acid, 2-hydroxy3,3-dimethylbutyric acid,
2-hydroxy-3-methylbutyric acid, 2-hydroxyisocaproic acid). In the present invention, an αω-hydroxy acid or a cyclic ester corresponding thereto, that is, a lactone can be used as the hydroxy acid. Specific examples of the latter cyclic ester (lactone) include:
For example, ε-caprolactone, 4-methylcaprolactone, 3,5,5-trimethylcaprolactone, 3,3,3.
Examples thereof include 5-trimethylcaprolactone, β-propiolactone, γ-butyrolactone, δ-valerolactone, and enanthlactone. In order to obtain the effects of the present invention, in particular, ε-caprolactone is most suitable in terms of physical properties of the resin. preferable. In the present invention, the most preferable specific combination of constituent elements (monomers) is a combination of succinic acid, ε-caprolactone, 1,4-butanediol and 1,4-cyclohexanedimethanol. The total number of moles of the aliphatic glycol such as 1,4-butanediol and the saturated monocyclic aliphatic diol such as 1,4-cyclohexanedimethanol is the mole of the aliphatic dicarboxylic acid represented by the general formula (1). It is preferable to use the same molar amount as the number or a slight excess.

The ratio of the cyclic ester such as hydroxy acid or caprolactone used is usually 0.0005 to 0.30 mol, preferably 0.001 to 0.20 mol per mol of the aliphatic dicarboxylic acid unit. The proportion of the saturated monocyclic aliphatic diol such as cyclohexanedimethanol is usually 0.0005 to 0.30 mol, preferably 0.001 to 0.25 mol, per 1 mol of the aliphatic dicarboxylic acid unit. Preferably 0.0
It is 5 to 0.20 mol. When the use ratio of the saturated monocyclic aliphatic diol per 1 mol of the aliphatic dicarboxylic acid unit is out of the range of 0.0005 to 0.30 mol, the mechanical strength of the molded product is improved and the mulch film for agriculture is processed. Tear resistance, that is, the film longitudinal direction (M
The strength and elongation at break are not improved.

Examples of the aliphatic dicarboxylic acid represented by the general formula (1) include succinic acid, adipic acid, suberic acid,
Examples thereof include aliphatic dicarboxylic acids such as sebacic acid and dodecanedioic acid, and acid anhydrides thereof. Among these, succinic acid, adipic acid, and sebacic acid are preferably used, but succinic acid is most preferably used from the viewpoint of physical properties of the resulting copolymer. Anhydrides and lower alcohol esters of these acids can be used as well. These can be used alone or in combination of two or more.

When the condensation reaction for producing the biodegradable resin according to the present invention is carried out, the reaction is preferably carried out in two steps of a precondensation step (first step) and a high molecular weight step (second step). . The reaction in the precondensation step (first step) is preferably carried out in the presence of a conventionally known catalyst for transesterification reaction. In the above reaction, the reaction temperature is 80 ° C to
The temperature is 300 ° C, preferably 100 ° C to 270 ° C, and more preferably 145 ° C to 230 ° C. Reaction time is 0.5
~ 5 hours, preferably 1-4 hours, the reaction pressure is reduced pressure,
It is desirable to carry out under normal pressure or slightly increased pressure (0.5 kg / cm ² G or less), specifically, under the condition of 760 to 100 Torr.

In the precondensation step, a low molecular weight condensate having an aliphatic diol bonded to the terminal is produced.
The number average molecular weight of this condensate is preferably 5,000 to 10,000, and the molecular weight can be appropriately adjusted depending on the reaction conditions and the reaction time. Precondensation process
Aliphatic polyester copolymer obtained by polycondensation reaction of the above-mentioned three components (1), (2) and (3) in (first step) or a hydroxy acid or a cyclic ester corresponding thereto which is optionally used May be random or blocks. Charge of each of the above components may be batch charge (random), divided charge (block), or polymerization of lactones into a polymer of dicarboxylic acid-glycol-diol, or polymerization of polylactone with dicarboxylic acid, glycol and diol. May be. The catalyst is not always necessary, but it is 10 ^-7 to 10 ^-3 mol, preferably 10 ^{-6 to} 5 with respect to 1 mol of the aliphatic dicarboxylic acid used as a raw material for the catalyst described below.
It may be used in an amount of × 10 ^-4 mol. When the removal of the water generated in the first step is completed and the temperature rises, the process proceeds to the next high molecular weight step (second step). Higher molecular weight process in the latter half
It is desirable that the (second step) is completed by increasing the reaction temperature while reducing the pressure of the reaction system in 2 to 10 hours, preferably 3 to 6 hours, and finally 180 ° C to 270 ° C, preferably 190 ° C. At a reaction temperature of up to 240 ° C., it is desirable that the degree of vacuum is 3 Torr or less, preferably 1 Torr or less.
In this step, it is preferable to use a general transesterification reaction catalyst, and 10 ^-7 to 10 ^-3 mol, preferably 1 to 1 mol of the aliphatic dicarboxylic acid used as a raw material.
^{Used in} an amount of 0 ^{-6 to} 5 x 10 ^-4 mol. If the amount of the catalyst is less than this range, the reaction does not proceed rapidly and the reaction takes a long time. On the other hand, if it exceeds this range, it causes thermal decomposition, cross-linking, coloring, etc. of the polymer at the time of polymerization, and also causes thermal decomposition in the molding process of the polymer, which is not preferable. Precondensation process in which dehydration reaction mainly proceeds
Specific examples of the catalyst that can be used in both the (first step) and the high molecular weight step (second step) in which the latter half transesterification reaction proceeds include the following. These catalysts may be used alone or in combination of two or more. Examples of the catalyst include various compounds of metals such as carboxylates, carbonates, borates, oxides, hydroxides, hydrogen compounds, alcoholates and acetylacetonate chelates. Examples of the metals include alkali metals such as lithium and potassium; alkaline earth metals such as magnesium, calcium and barium; typical metals such as tin, antimony and germanium;
Examples thereof include transition metals such as lead, zinc, cadmium, manganese, cobalt, nickel, zirconium, titanium and iron; lanthanoid metals such as bismuth, niobium, lanthanum, samarium, europium, erbium and ytterbium. As the catalyst, a nitrogen-containing basic compound, boric acid, boric acid ester, or the like is also used.
Specifically, as the alkali metal compound, sodium hydroxide, potassium hydroxide, lithium hydroxide, potassium hydrogen carbonate, lithium hydrogen carbonate, sodium carbonate, potassium carbonate, lithium carbonate, sodium acetate, potassium acetate,
Examples thereof include lithium acetate, sodium stearate, lithium stearate, sodium borohydride, sodium phenyl borohydride, lithium benzoate, sodium dihydrogen phosphate, potassium dihydrogen phosphate and lithium dihydrogen phosphate. As the alkaline earth metal compound, calcium hydroxide, barium hydroxide, magnesium hydroxide,
Strontium hydroxide, calcium hydrogen carbonate, barium hydrogen carbonate, magnesium hydrogen carbonate, strontium hydrogen carbonate, calcium carbonate, barium carbonate, magnesium carbonate, strontium carbonate, calcium acetate, barium acetate, magnesium acetate, strontium acetate, calcium stearate, barium stearate , Magnesium stearate, strontium stearate and the like. Typical metal compounds include dibutyltin hydroxide, dibutyltin dilaurate, antimony trioxide, germanium oxide, bismuth carbonate carbonate, bismuth acetate acetate and the like. The transition metal compounds include lead acetate, zinc acetate, zinc acetylacetonate, cadmium acetate, manganese acetate, manganese acetylacetonate, cobalt acetate, cobalt acetylacetonate, nickel acetate, nickel acetylacetonate, zirconium acetate, zirconium acetylacetate. Nate, titanium acetate, tetrabutoxy titanate, tetraisopropoxy titanate, titanium tetraisopropoxide, titanium hydroxyacetylacetonate,
Examples thereof include iron acetate, iron acetylacetonate, and niobium acetate. Examples of the rare earth compound include lanthanum acetate, samarium acetate, europium acetate, erbium acetate, and ytterbium acetate. Specific examples of the nitrogen-containing basic compound include tetraethylammonium hydroxide, tetraethylammonium hydroxide, tetrabutylammonium hydroxide, trimethylbenzylammonium hydroxide, and other organic ammonium hydroxides derived from aliphatic amines and aromatic amines. Tertiary amines such as trimethylamine, triethylamine, dimethylbenzylamine and triphenylamine; R ₂ NH (wherein R is an alkyl group such as methyl and ethyl, an aryl group such as phenyl and toluyl)
Secondary amines represented, primary amines represented by RNH ₂ (wherein R is the same as above); ammonia, tetramethylammonium borohydride, tetrabutylammonium borohydride, tetrabutylammonium tetraphenylborate, tetramethyl Examples thereof include basic compounds such as ammonium tetraphenyl borate. Of these, tetraalkylammonium hydroxides are particularly preferable. As boric acid ester,
Specifically, trimethyl borate, trihexyl borate,
Examples thereof include triheptyl borate, triphenyl borate, tritolyl borate, and trinaphthyl borate. Furthermore, it is preferable to use magnesium phosphate trihydrate or the like as a co-catalyst. In particular, it is preferable to use titanium tetraisopropoxide and magnesium phosphate trihydrate in the catalyst together, from the viewpoint of reducing the acid value. The reaction in both the precondensation step (first step) and the high molecular weight step (second step) is preferably carried out in an atmosphere of an inert gas such as nitrogen.

The above-mentioned high molecular weight step is a step of producing a high molecular weight condensate by condensing while releasing the aliphatic diol bonded to the terminal of the low molecular weight condensate. It is possible to generate a condensate having a molecular weight of 20,000 or more. In this case, the reaction conditions may be such that the by-produced aliphatic diol can exist as a gas. It is desirable to carry out this molecular weight conversion step in a polymerization apparatus with high stirring efficiency.

The high molecular weight polyester of the present invention has a number average molecular weight of 20,000 or more, preferably 50,000 or more, more preferably 80,000 or more. In this case, the upper limit of the number average molecular weight is 1,000,000, preferably about 200,000. Then, the high-molecular-weight aliphatic polyester produced by the present invention has a hydroxy acid such as caprolactone used as necessary, and a copolymer structure with a monocyclic dimethyl alcohol such as cyclohexanedimethanol, and is broken. It is possible to obtain a high molecular weight aliphatic polyester having a high point elongation, excellent properties as a raw material for agricultural films, and excellent processability. Moreover, this high-molecular-weight aliphatic polyester film has improved biodegradability based on its aliphatic ester bond and, particularly, when the resin composition of the present invention is processed into an agricultural mulch film, tearing of the mulch film is caused. The strength and elongation at break are remarkably improved. Furthermore, diamine and the like are not generated as decomposition products due to biodegradation. The resin of the present invention includes
Another biodegradable resin may be added within a range that does not impair the performance. As the other biodegradable resin, synthetic and / or natural polymers are used. As synthetic polymers, aliphatic polyester, polyamide, polyamide ester, biodegradable cellulose ester, polypeptide,
Polyvinyl alcohol or a mixture thereof may be used. Of these, aliphatic polyester, biodegradable cellulose ester, polypeptide and polyvinyl alcohol are preferable.

[0013]

EXAMPLES Next, the present invention will be specifically described by way of examples. Various physical properties of the biodegradable resin and film of the present invention were measured by the following methods.

(Molecular weight and molecular weight distribution) A calibration curve was prepared from standard polystyrene using the gel permeation chromatograph (GPC) method, and the number average molecular weight (Mn),
Weight average molecular weight (Mw) and molecular weight distribution (Mw / Mn)
I asked. Chloroform was used as the eluent.

(Thermal Property) Differential Scanning Calorimeter (DS)
The melting temperature and glass transition point were determined by C). In addition, the thermal decomposition temperature (temperature rising rate 20
C / min) was determined.

(Filming) An inflation film was obtained from the pellets obtained in Examples 1 to 5 under the following conditions. Film take-up speed: 17.0 to 22.0 m / mi
n, lip width: 2.0 mm, film width: 380 mm,
Film thickness: 20 mm. Using the resin pellets and the film-shaped molded product thus obtained, the following various evaluations were performed, and the results are shown in Table 1.

(Tear Test) Sample: Each of the films obtained above was cut into a width of 50 mm and a length (MD direction) of 100 mm, and one end of the width was cut from the center to a length of 30 mm. I was there. Sample is 23 ℃ x 5
The humidity was adjusted for 24 hours with a thermo-hygrostat of 0% RH, and the measurement was performed. The tear strength is measured under the following conditions: sample length (distance between chucks): 50 mm, equipment used: ORIENT
EC RTA-500, load cell: 5 kgf, 20
%, Crosshead speed: 500 mm / min, number of tests: n = 3, and the results are shown as average values. The sensory evaluation criteria are as follows. ⊚: Tear strength is strong, tears at an angle, and the tear surface is wavy. ◯: Tear strength is strong, the tear is linear, and the tear surface is wavy. X: The tear strength is weak, the tear is linear, and the wavy surface is small. XX: The tear strength is weak, the tear is linear, and there is almost no waviness on the tear surface.

(Tensile Test) Based on JIS K-7113, a tensile test was conducted using the above-mentioned films punched into No. 2 dumbbell pieces. The measurements are MD and T
D Both directions were performed. Sample is 23 ℃ x 50%
The humidity was adjusted for 24 hours using a thermo-hygrostat of RH, and the measurement was performed. The measurement conditions for tensile strength are: sample length (distance between chucks): 30 mm, equipment used: ORIENTE
RTA-500 manufactured by C, load cell: 100 kgf, 4
0%, crosshead speed: 10 mm / min, number of tests: n = 3, and the results are shown as average values.

(Biodegradability) Biodegradability was evaluated according to a simple degradability test (JIS K-6950) using activated sludge. Using Himeji City standard activated sludge, the biodegradability (% by weight) after 28 days of the test period was measured. When the biodegradability value obtained in the above test is less than 60%, it is indicated by x, when it is 60% or more, it is indicated by O, and when it is 80% or more, it is indicated by ⊚.

Example 1 3626 g (30.7 mol) of succinic acid, 2710 g (30.1 mol) of 1,4-butanediol and 18 caprolactone were placed in a stainless steel prepolymerization apparatus having an internal volume of 12 liters.
4 g (1.61 mol), cyclohexanedimethanol 4
56 g (3.16 mol), titanium tetraisopropoxide 5 ml (15.4 mmol), and magnesium phosphate trihydrate 0.89 g (5.1 mmol) were charged, and the temperature was gradually raised under a nitrogen atmosphere, The water that formed was removed by distillation (1037 g). Finally the internal temperature is 2
The temperature was raised to 20 ° C., and when the distillation of water stopped, the apparatus was connected to a vacuum pump, and the reaction was continued at 240 ° C. for 3 hours. When the polymerization progressed and the viscosity increased, the reaction product was transferred to the present polymerization device (internal volume: 12 liters), and the temperature was 240 ° C, about 1
The reaction was continued under a reduced pressure of mmHg for 7.5 hours. The obtained polymer is white and has Mn84,800 and Mw179,5.
00, and its Mw / Mn was 2.12. The melting temperature was 99.1 ° C and the 2% weight loss temperature was 317 ° C. The proportions of caprolactone and cyclohexanedimethanol contained in this polymer were such that the aliphatic dicarboxylic acid component 10 contained in the polymer was 10%, respectively.
5.2 mol and 10.3, which are the same as the charged amount, per 0 mol
It was a molar ratio.

Comparative Example 1 3626 g (30.7 mol) of succinic acid, 2906 g (32.2 mol) of 1,4-butanediol and 4.73 ml of titanium tetraisopropoxide were added to a stainless steel prepolymerization apparatus having an internal volume of 12 liters. (14.4 mmol) and 0.837 g (4.8 mmol) of magnesium phosphate trihydrate were charged, and the produced water was distilled off while gradually raising the temperature in a nitrogen atmosphere. Finally, the internal temperature rose to 200 ° C, and when the distillation of water stopped, the apparatus was connected to a vacuum pump and the reaction was continued at 240 ° C for 2.2 hours. When the polymerization progressed and the viscosity increased, the reaction product was transferred to the present polymerization device (internal volume 12 liters),
The reaction was continued for 5.2 hours under reduced pressure of about 1 mmHg at ℃.
The polymer obtained is milky white, Mn 85,200, Mw
181,300, and its Mw / Mn was 2.13.

Example 2 3626 g (30.7 mol) of succinic acid, 2564 g (28.5 mol) of 1,4-butanediol and 38 caprolactone were placed in a stainless steel prepolymerization apparatus having an internal volume of 12 liters.
9 g (3.41 mol), cyclohexanedimethanol 5
62 g (4.92 mol), titanium tetraisopropoxide 5 ml (15.4 mmol), and magnesium phosphate trihydrate 0.89 g (5.1 mmol) were charged, and the temperature was gradually raised under a nitrogen atmosphere. The water that formed was removed by distillation (1056 g). Finally the internal temperature is 2
The temperature was raised to 30 ° C., and when the distillation of water stopped, the apparatus was connected to a vacuum pump, and the reaction was continued at 240 ° C. for 2 hours. When the polymerization progressed and the viscosity increased, the reaction product was transferred to the present polymerization device (internal volume: 12 liters), and the temperature was 240 ° C, about 1
The reaction was continued under reduced pressure of mmHg for 6 hours. The obtained polymer is white and has Mn of 97,200 and Mw of 209,000.
And its Mw / Mn was 2.15. Its melting temperature is 91.2 ° C and its 2% weight loss temperature is 3
It was 14 ° C. The proportions of caprolactone and cyclohexanedimethanol contained in this polymer were 11.1 moles and 16.0 moles, respectively, per 100 moles of the aliphatic dicarboxylic acid component contained in the polymer.

Example 3 3626 g (30.7 mol) of succinic acid, 2564 g (28.5 mol) of 1,4-butanediol and 61 caprolactone were placed in a stainless steel prepolymerization apparatus having an internal volume of 12 liters.
9 g (5.42 mol), cyclohexanedimethanol 5
79 g (4.01 mol), titanium tetraisopropoxide 5 ml (15.4 mmol), and magnesium phosphate trihydrate 0.89 g (5.1 mmol) were charged, and the temperature was gradually raised under a nitrogen atmosphere. The water that formed was removed by distillation (1072 g). Finally the internal temperature is 2
The temperature was raised to 30 ° C., and when the distillation of water stopped, the apparatus was connected to a vacuum pump, and the reaction was continued at 240 ° C. for 2 hours. When the polymerization progressed and the viscosity increased, the reaction product was transferred to the present polymerization device (internal volume: 12 liters), and the temperature was 240 ° C, about 1
The reaction was continued under reduced pressure of mmHg for 9.7 hours. The polymer obtained is white and has a Mn of 94,500 and a Mw of 185,8.
And had an Mw / Mn of 1.97. The melting temperature was 85.4 ° C and the 2% weight loss temperature was 324 ° C. The proportions of caprolactone and cyclohexanedimethanol contained in this polymer were such that the aliphatic dicarboxylic acid component 10 contained in the polymer was 10%, respectively.
The ratio was 17.7 mol and 13.1 mol per 0 mol.

Example 4 3627 g (30.7 mol) of succinic acid, 2213 g (24.6 mol) of 1,4-butanediol and 1112 g (7.71 mol) of cyclohexanedimethanol were placed in a stainless steel prepolymerization apparatus having an internal volume of 12 liters. ), 5 ml (15.4 mmol) of titanium tetraisopropoxide, and 0.89 g (5.1 mmol) of magnesium phosphate trihydrate are charged, and the water produced is gradually heated under a nitrogen atmosphere. It was removed by distillation (1044 g). Finally, the internal temperature rose to 230 ° C, and when the distillation of water stopped, the apparatus was connected to a vacuum pump and the reaction was continued at 240 ° C for 2 hours. When the polymerization progressed and the viscosity increased, the reaction product was transferred to the main polymerization device (internal volume: 12 liters) and
The reaction was continued at 40 ° C. under a reduced pressure of about 1 mmHg for 6.9 hours. The polymer obtained is white and has a Mn of 98,200, M
It had w191,300 and its Mw / Mn was 1.95. Also, its melting temperature is 84.2 ° C.
The% weight loss temperature was 326 ° C. The ratio of cyclohexanedimethanol contained in this polymer is 100 mol of the aliphatic dicarboxylic acid component contained in the polymer,
The ratio was 25.1 mol.

Example 5 3627 g (30.7 mol) of succinic acid, 2598 g (28.8 mol) of 1,4-butanediol and 492 g (3.41 mol of cyclohexanedimethanol) were placed in a stainless steel prepolymerization apparatus having an internal volume of 12 liters. ), 5 ml (15.4 mmol) of titanium tetraisopropoxide, and 0.89 g (5.1 mmol) of magnesium phosphate trihydrate are charged, and the water produced is gradually heated under a nitrogen atmosphere. It was removed by distillation (1034 g). Finally, the internal temperature rose to 220 ° C, and when the distillation of water stopped, the apparatus was connected to a vacuum pump and the reaction was continued at 240 ° C for 2 hours. When the polymerization progressed and the viscosity increased, the reaction product was transferred to the main polymerization device (internal volume: 12 liters) and
The reaction was continued at 40 ° C. under a reduced pressure of about 1 mmHg for 5.5 hours. The polymer obtained is white and has a Mn of 94,500, M
It had a w of 198,900 and its Mw / Mn was 2.10. The melting temperature was 101.4 ° C and the 2% weight loss temperature was 313 ° C. The ratio of cyclohexanedimethanol contained in this polymer was 11.1 mol per 100 mol of the aliphatic dicarboxylic acid component contained in the polymer.

The results of the tear test, tensile test and biodegradability test of Examples 1 to 5 and Comparative Example 1 are shown in Table 1.

[Table 1] Comparative Example 1 is a resin of polybutylene succinate alone, which is not copolymerized with cyclohexanedimethanol and caprolactone, but has a small tear strength and elongation at break, a very slow biodegradation rate, and a biodegradable agricultural mulch film. The result was not suitable for such uses. On the other hand, a resin obtained by copolymerizing butylene succinate with cyclohexanedimethanol and caprolactone and a resin obtained by copolymerizing butylene succinate with cyclohexanedimethanol have tear strengths significantly higher than 150 g / cm, and T
The breaking elongation in the D direction was 700% or more, and had sufficient mechanical properties for use as a mulch film. Furthermore, the biodegradability of these copolymers was good, and it was confirmed that they are resins suitable for biodegradable agricultural mulch films and the like.

[0027]

The biodegradable resin of the present invention has a saturated monocyclic aliphatic diol structure such as polybutylene succinate and cyclohexane dimethanol, or polybutylene succinate, and cyclohexane dimethanol, and optionally a structure. The film formed by molding it has a copolymer structure with caprolactone and is excellent in flexibility. Moreover, this film has excellent physical properties as an agricultural mulch film. Moreover, this biodegradable resin has excellent biodegradability based on its aliphatic ester bond.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) C08L 67:00 C08L 67:00 (72) Inventor Yoichi Taguchi 1-1-1 East, Tsukuba City, Ibaraki Prefecture (72) Inventor, Takashi Masuda, Tsukuba Center, National Institute of Advanced Industrial Science and Technology 1-1-2, East 1-1, Tsukuba City, Ibaraki Prefecture 1-1 Independent Administrative Law, National Institute of Advanced Industrial Science and Technology Tsukuba Center (72) Inventor Kazuro Nakayama 1-1-1 East, Tsukuba City, Ibaraki Prefecture Independent Administrative Law, National Institute of Advanced Industrial Science and Technology (72) Inventor Hiroshi Katayama 1239 Shinjae, Aboshi-ku, Himeji-shi, Hyogo Prefecture Inside Daicel Chemical Industry Co., Ltd. (72) Inventor Naofumi Teranishi Hyogo Prefecture 1239 Shinjae, Aboshi-ku, Ryoichi Daicel Chemical Industry Co., Ltd. Research Institute F-term (reference) 2B024 DB01 4F071 AA43 AA44 AA80 AF52 AH01 BA01 BB06 BB09 BC01 4J029 AA02 AA03 AA05 AB01 AB07 AC02 AD10 AE03 BA03 BA04 BA05 BA08 CA01 CA03 BD03A04 EA01 EA02 EA03 EA05 EG02 EG03 EG05 EG07 EG09 HA01 HB01 KE02 KE15 4J200 AA02 AA06 AA10 AA19 AA28 CA01 DA01 EA01 EA09 EA11

Claims (8)

[Claims] 1. A compound represented by the general formula (1): (Wherein R ¹ represents a direct bond or a divalent aliphatic group having 1 to 12 carbon atoms) and an aliphatic dicarboxylic acid represented by the general formula (2): (In the formula, R ² represents a divalent aliphatic group having 2 to 4 carbon atoms) and an aliphatic glycol represented by the general formula (3) It is obtained by copolymerizing a saturated monocyclic aliphatic diol represented by the formula (wherein R ³ represents a monocyclic saturated hydrocarbon group), and optionally a hydroxy acid or a cyclic ester corresponding thereto. Biodegradable resin. 2. The biodegradable resin according to claim 1, which contains a hydroxy acid or a cyclic ester corresponding thereto. 3. R ¹ and R ² are alkylene groups represented by (CH ₂ ) ₂ or R ¹ is (CH ₂ ) ₂ and R ² is represented by (CH ₂ ) _4. The biodegradable resin according to claim 1 or 2, which is an alkylene group or R ¹ is (CH ₂ ) ₂ and R ² is an alkylene group represented by (CH ₂ ) ₆ . 4. The R ¹ is a cyclohexane ring.
The biodegradable resin according to any one of 1 to 3. 5. The biodegradable resin according to claim 1, wherein the cyclic ester corresponding to the hydroxy acid is caprolactone. 6. The saturated monocyclic aliphatic diol represented by the general formula (3) is contained in a molar ratio of 0.0005 to 0.5% based on the aliphatic dicarboxylic acid represented by the general formula (1). The biodegradable resin according to any one of claims 1 to 5, which is 30. 7. A film formed by molding the biodegradable resin according to claim 1. 8. The film of claim 7, wherein the film is an agricultural mulch film.