KR101317767B1 - Biodegradable polyester and manufacturing method thereof - Google Patents

Abstract

The present invention relates to a biodegradable polyester and a method for producing the same, wherein the spinning process is possible while maintaining the biodegradability and the color tone b value is 5 or less, and an aromatic acid containing a phenylene group and a carboxyl It is characterized by being produced by esterifying and polycondensing an acid component comprising an aliphatic acid containing acid groups and sodium 3,5-dicarbomethoxybenzenesulfonates and a diol component having 2 to 14 carbon atoms.

Description

Biodegradable polyester and manufacturing method thereof

The present invention relates to a biodegradable polyester and a method for producing the same, and in particular, a biodegradable polyester having a biodegradability while maintaining biodegradability and having a spinning process, and having a hue b value of 3 to 5 and a The present invention relates to a method of manufacturing yarns, cotton, nonwovens, fabrics, sheets, and the like through the present invention.

Plastic has been extensively used for various purposes because of its excellent mechanical properties, chemical resistance and durability. However, conventional plastics, that is, synthetic resins, do not decompose on their own, . Recently, as environmental pollution problem has become a big problem in society, research on biodegradable resins that can be completely decomposed in nature has been actively carried out and has attracted worldwide interest.

Conventional biodegradable resins, ie, polybutylene succinate, polyethylene succinate, polylactic acid, etc., are excellent in biodegradability, but lack economical efficiency at a high price, or are limited to molding injection molding products which have a low melting point. It is not possible to develop a product line that must maintain thermal stability in the production of products like the fiber product group. Existing biodegradable polymers have limited mechanical properties, chemical resistance, and low durability, and are limited to disposable packaging materials, that is, injection molding products.

In addition, the use of diethylene glycol (DEG) as a raw material used in the polymerization leads to the disadvantage that it is difficult to secure the drying conditions in the drying step before the spinning step for producing the fiber product group, Because of the aluminum acetate base, which is a common nocatalyst, there is a drawback that spinning workability is difficult due to initial pack pressure during spinning. In addition, the resulting polymer has a color tone b value of 9 or more, which is not suitable for use in a textile product group.

In this regard, such as the Republic of Korea Patent Application No. 2006-7002339, the name of the invention "biodegradable polyester mixture" and No. 2001-0055645, the name of the invention "biodegradable polyester resin composition reinforced with tear strength" Efforts are being made to improve. In particular, the Republic of Korea Patent Application No. 2010-0075068 produced an aromatic copolyester compound that can be manufactured as a textile product group, but the color tone b value is 9 or more, and the spinning workability is not easy due to the high initial pack pressure during spinning In other words, there is a part that is insufficient to develop products for textile use.

In order to solve this problem, Japanese Patent Application Laid-Open No. Hei 4-189822, 189823, etc., esterify aliphatic dicarboxylic acids and aliphatic dihydric glycols, perform a condensation polymerization reaction, and then add an isocyanate compound and react to obtain a molecular weight. By increasing the molecular weight and melt viscosity to improve the physical properties compared to the existing aliphatic polyester, but did not secure the physical properties that can be produced by fibers or films.

The present invention is easy to spin the work by adjusting the composition of the raw materials and adjusting the temperature and time conditions such that the use can be deployed in the product line as described above, while maintaining the range of the color tone b value suitable for the fiber product group 3 to 5 It is an object to provide a biodegradable aromatic copolyester.

It is also an object of the present invention to provide a method for producing biodegradable aromatic copolyester under optimum production conditions.

Biodegradable polyesters according to the present invention are aromatic acids comprising phenylene groups, aliphatic acids containing carboxylic acid groups and acid components comprising sodium 3,5-dicarbomethoxybenzenesulfonates, It is characterized by being prepared by esterifying and polycondensing the diol component.

The biodegradable polyester may further comprise a complementing agent in an amount in the range of 60 to 130 ppm based on the total weight of the polymer.

The aliphatic acid is preferably oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, suberic acid, and suberic acid. ), Citric acid, Pimeric acid, Azelaic acid, Sebasic acid, Nonanoic acid, Decanoic acid, Dodecanoic acid acid), hexanodecanoic acid or a mixture of two or more thereof.

The aromatic acid may be preferably selected from the group consisting of terephthalic acid, isophthalic acid, dimethyl terephthalate, dimethyl isophthalate or a mixture of two or more thereof. .

The diol component is an ethylene glycol (Ethylene Glycol), propylene glycol (Propylene Glycol), trimethyl glycol (Trimethyl Glycol), tetramethylene glycol (Petramethylene Glycol), pentamethyl glycol, hexamethylene glycol Hexamethylene Glycol, Heptamethylene Glycol, Octamethylene Glycol, Nonamethylene Glycol, Decamethylene Glycol, Undecamethylene Glycol, Dodecamethylene Glycol Dodecamethylene Glycol), Tridecamethylene Glycol, Tetracamethylene Glycol or a mixture of two or more thereof.

The acid component may include 50 to 80 mole% of the aromatic acid, 10 to 50 mole% of the aliphatic acid and 0.1 to 15 mole% of sodium 3,5-dicarbomethoxybenzenesulfonate.

The biodegradable polyester may be one having an intrinsic viscosity (IV) of 0.6 to 0.7 and a hue b value of hue 5 or less.

The biodegradable polyester may be one having a glass transition temperature (Tg) of 55 to 65 ℃.

In addition, the method for producing a biodegradable polyester according to the present invention (1) an acid containing an aromatic acid containing a phenylene group, an aliphatic acid containing carboxylic acid groups and sodium 3,5-dicarbomethoxybenzenesulfonate The diol component having 2 to 14 carbon atoms is mixed so that the ratio of the acid component: diol component is within the range of 1.0: 1.0 to 1.4 in molar ratio, and the speed of 40 to 80 rpm at 150 to 190 minutes at 200 to 240 ° C. Esterification step of preparing an oligomer while stirring; And (2) a polymerization step of polymerizing the oligomer at 230 to 280 ° C. for 180 to 210 minutes at 40 to 100 rpm.

According to the present invention, it is possible to provide a biodegradable polyester and a method for producing the same, which are capable of spinning while maintaining biodegradability while maintaining biodegradability and maintaining a hue b value of 5 or less.

In addition, according to the present invention, the obtained biodegradable polyester has excellent physical properties, in particular, a hue b value of 5 or less, a high melting point, and excellent spinning properties, so that polyester fibers and films can be produced, and nonwoven fabrics or injection molded articles. There is an effect that can be easily produced.

Hereinafter, preferred embodiments of the present invention will be described in detail. In describing the present invention, detailed descriptions of related well-known functions or configurations are omitted in order not to obscure the subject matter of the present invention.

The terms " about "," substantially ", etc. used to the extent that they are used herein are intended to be taken to mean an approximation of, or approximation to, the numerical values of manufacturing and material tolerances inherent in the meanings mentioned, Accurate or absolute numbers are used to help prevent unauthorized exploitation by unauthorized intruders of the referenced disclosure.

Biodegradable polyesters according to the present invention are aromatic acids comprising phenylene groups, aliphatic acids comprising carboxylic acid groups and acid components comprising sodium 3,5-dicarbomethoxybenzenesulfonates, It is characterized by being prepared by esterifying and polycondensing the diol component.

The biodegradable polyester of the following structural formula 1 according to the present invention has a low molecular weight by decomposition under high temperature and humidity conditions and is finally decomposed into monomers such as terephthalic acid or alkylene glycol and then decomposed into microorganisms or bacteria Composting, that is, biodegradation. As a condition for biodegradation to occur well, it is preferable that the glass transition temperature (Tg) of the material is as low as possible, but in general, the biodegradation process proceeds at a temperature of 58 ° C and a humidity of 50% according to KA M 3100-1, When the glass transition temperature is higher than the composting, i.e., the biodegradation process temperature, composting becomes very difficult, so it is preferable to maintain the glass transition temperature (Tg) between 55 and 65 deg. If the polymer is manufactured at the glass transition temperature of 55 ℃ or less to increase the biodegradability, it is required to satisfy the condition that carbon dioxide emission is more than 60% of the standard sample cellulose after 180 days in order to develop it into clothing among the textile product group. It may disintegrate inside, making it difficult to deploy into apparel products.

[Structural formula 1]

The aliphatic acid in the acid component is preferably, oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, subberin Acid (suberic acid), citric acid, pimeric acid, azelaic acid, sebasic acid, nonanoic acid, decanoic acid, dode It can be selected from the group consisting of Dodecanoic acid (Dodecanoic acid), hexanodecanoic acid (Headecanoic acid) or a mixture of two or more thereof. The aliphatic acid is particularly preferably used by mixing one or two or more of oxalic acid, succinic acid, adipic acid, sebacic acid and the like having an even carbon number, which is preferable because it has excellent physical properties when reacting with a divalent glycol. Has an advantage. The aliphatic acid is preferably used in the range of 10 to 50 mol% of the total weight of the acid component, when the amount of the aliphatic acid is used in less than 10 mol%, there may be a disadvantage that does not have biodegradability, On the contrary, if it exceeds 50 mol%, there may be a problem that the mechanical properties during the molding process is very poor.

Sodium 3,5-dicarbomethoxybenzenesulfonate in the acid component functions to increase the biodegradability of the biodegradable polyesters to be obtained in the present invention, the sodium 3,5-dicarbomethoxybenzenesulfo Nate is suitably used in an amount in the range of 0.1 to 15 mol% of the total weight of the acid component, and biodegradation obtained when the sodium 3,5-dicarbomethoxybenzenesulfonate is used in less than 0.1 mol% There may be a problem that the biodegradability of the polyester is deteriorated, on the contrary, if it exceeds 15 mol%, there may be a problem that the moldability is deteriorated.

The aromatic acid may be preferably selected from the group consisting of terephthalic acid, isophthalic acid, dimethyl terephthalate, dimethyl isophthalate or a mixture of two or more thereof. . The amount of the aromatic acid may be used as a limited residual amount of the aliphatic acid and the sodium 3,5-dicarbomethoxybenzenesulfonate in the total weight of the acid component, but if the amount of the aromatic acid is too small, There may be a problem that the radioactivity for applying the biodegradable polyester to the fiber product group becomes poor, on the contrary, too much, there may be a problem that the decomposition and composting of the biodegradable polyester obtained is difficult.

The diol component is ethylene glycol, propylene glycol, trimethyl glycol, tetramethylene glycol, pentamethylene glycol, hexamethylene glycol, heptamethylene glycol, octamethylene glycol, nonamethylene glycol, decamethylene glycol, undecamethylene glycol having 2 to 14 carbon atoms As an aliphatic divalent glycol of dodecamethylene glycol, tridecamethylene glycol and tetradecamethylene glycol, ethylene glycol, tetramethylene glycol, hexamethylene glycol, etc. having 2 to 6 carbon atoms and even number are particularly excellent in improving physical properties. .

It is important because the discoloration of the polymer is severe depending on the type and the amount of the catalyst used in the esterification reaction. In the present invention, the lithium compound mainly used to prevent discoloration and discoloration of sodium A cobalt compound is used, and the lithium compound is most effective when metal lithium or lithium acetate is used, and the amount of the lithium compound is in the range of 100 to 600 ppm based on the total weight of the polymer as a theoretical value obtained after polymerization. It is most effective when used. In addition, the cobalt compound is most effective when using metal cobalt or cobalt acetate, the amount of the cobalt compound is most effective when using 600 to 130ppm based on the total weight of the polymer as a theoretical value obtained after the polymerization.

The amount of catalyst and stabilizer used in the polycondensation reaction has a great influence on the properties of the polymer, in particular, the reaction rate and color, and in the case of the aliphatic polyester polymer, it is generally performed at a low temperature of 200 to 270 ° C. The choice of catalyst and thermal stabilizer is important by reacting at higher temperatures of 240 to 285 ° C. to produce aromatic copolyester polymers. In addition, when a catalyst used as a co-catalyst is added to increase the reaction rate, such as aluminum acetate basic, it is preferable to avoid the use, since the foreign matter in the polymer increases, causing the initial pack pressure during spinning.

Antimony compound was used as a catalyst used in the polycondensation reaction of the present invention, phosphorus compound was used to suppress color discoloration at high temperature, and antimony compound such as antimony trioxide, antimony tetraoxide, antimony pentoxide, etc. Antimony trihalide, antimony trichloride, antimony trifluoride, antimony trichloride, antimony triacetate, antimony triacetate, antimony benzoate, antimony tristearate, and the like. The amount of use is most effective when 100 to 600 ppm is used based on the total weight of the polymer as a theoretical value obtained after the polymerization.

It is preferable to use phosphoric acid and derivatives thereof such as phosphoric acid, monomethyl phosphate trimethyl phosphate and tributyl phosphate, and among these, trimethyl phosphate or triphenyl phosphite is preferable, and the amount of phosphorus compound is preferably used. It is most effective when using 100 to 500 ppm based on the total weight of the polymer as a theoretical value obtained after the polymerization.

The biodegradable polyester according to the present invention may be one having an intrinsic viscosity (IV) of 0.6 to 1.0, a tint b value of tint 5 or less. If the intrinsic viscosity is less than 0.6, there may be a problem that spinning is difficult because the melt viscosity is low in the step of spinning for spreading the application in a textile product group. On the other hand, if the intrinsic viscosity is more than 1.0, There is a problem that workability is poor. The biodegradable polyester may be one having a glass transition temperature (Tg) of 55 to 65 ℃. If the glass transition temperature is less than 55 ° C, there may be a problem in the drying process of the polymer before spinning, on the contrary, if the glass transition temperature exceeds 65 ° C, there may be a problem that the biodegradability is low and the decomposition is not good. . In general, biodegradation evaluation conditions are made within the temperature 58 ℃ to 65 ℃ under composting conditions, Tg is better than 65 ℃ because the biodegradation is good when the Tg is lower than the composting conditions.

In addition, the method for producing a biodegradable polyester according to the present invention (1) an acid containing an aromatic acid containing a phenylene group, an aliphatic acid containing carboxylic acid groups and sodium 3,5-dicarbomethoxybenzenesulfonate The diol component having 2 to 14 carbon atoms is mixed so that the ratio of the acid component: diol component is within the range of 1.0: 1.0 to 1.4 in molar ratio, and the speed of 40 to 80 rpm at 150 to 190 minutes at 200 to 240 ° C. Esterification step of preparing an oligomer while stirring; And (2) a polymerization step of polymerizing the oligomer at 230 to 280 ° C. for 180 to 210 minutes at 40 to 100 rpm.

The esterification step includes an aromatic acid including a phenylene group, an aliphatic acid including carboxylic acid groups and an acid component including sodium 3,5-dicarbomethoxybenzenesulfonate, and a diol component having 2 to 14 carbon atoms. The oligomer is prepared by mixing an acid component: diol component in a molar ratio within a range of 1.0: 1.0 to 1.4, and stirring at 200 to 240 ° C. for 150 to 190 minutes at a speed of 40 to 80 rpm. The acid and diol components in the esterification step are the same as or similar to those described above, and thus will be omitted.

The ranges of temperature and stirring speed in the esterification step are the same as or similar to those in the conventional polyester production process, and can be understood to be well known to those skilled in the art.

In the present invention, particularly, the complementing agent is added in the esterification step, and the amount of the supplementing agent may be in an amount of 60 to 130 ppm based on the total weight of the theoretical polymer amount obtained in the polymerization step. Preferably, the cobalt compound may be used as the complementing agent, and the cobalt compound may be metal cobalt or cobalt acetate. The use amount of the cobalt compound is most effective when using 60 to 130 ppm based on the total weight of the polymer as a theoretical value obtained after the polymerization. When the amount of the complementary agent is used less than 60ppm, there may be a problem that the color tone is not improved, if it exceeds 130ppm, if it exceeds 130ppm, there is no change in the color tone, there may be a problem to act as a foreign material when spinning .

The ranges of temperature and stirring speed in the polymerization step are the same as or similar to those in the conventional polyester production method, and can be understood to be well known to those skilled in the art.

Examples of the process for producing the biodegradable polyesters of the present invention are shown below, although not limited thereto.

Example  One

In a 250 ml flask equipped with a stirrer and a condenser, 89 mol% of terephthalic acid, 10 mol% of succinic acid, and 1 mol% of sodium 3,5-dicarbomethoxybenzenesulfonate were added as a reaction molar ratio as an acid component. After the weight ratio of 1: 1.2 with respect to the acid component, 400 ppm of lithium acetate as a esterification catalyst and 120 ppm of cobalt acetate as a color supplement to prevent discoloration, and the temperature in the reactor is 120 over 30 minutes from room temperature It heated up to 150 degreeC and heated up to 250 degreeC for 120 minutes, stirring. At this time, methanol and water, which are generated byproducts, were flowed out through a condenser. Subsequently, after adding 300 ppm of phosphoric acid as a heat stabilizer and 300 ppm of antimony trioxide as a catalyst, the mixture was gradually reduced in pressure to 0.5 mmHg over 40 minutes, and stirred for 180 minutes while the temperature was raised to 280 ° C. Agitation was stopped and discharged to obtain a biodegradable polyester according to the present invention.

The obtained biodegradable polyester was dried at 80 ° C. and 100 ° C. for 2 hours, and then dried at 140 ° C. for 4 hours, to prepare a yarn at a spinning temperature of 240 ° C., to evaluate the radioactivity, and further to 240 ° C. twin-extu After the 0.5 mm film was produced through a T die sheet forming machine equipped with a twin extruder, the moldability was confirmed. The properties of the polymers for the biodegradable polyesters according to Example 1 of the present invention are shown in Table 1 below.

Example  2

Terephthalic acid was reduced from 89 mol% to 79 mol%, and was carried out in the same manner as in Example 1 except using 20 mol% of succinic acid.

Example  3

The same procedure as in Example 1 was conducted except that 10 mol% of adipic acid was used instead of succinic acid.

Example  4

Terephthalic acid was reduced from 89 mol% to 79 mol%, and was carried out in the same manner as in Example 1 except for using 20 mol% of adipic acid instead of succinic acid.

Comparative Example  One

Terephthalic acid was reduced from 89 mol% to 59 mol%, and was carried out in the same manner as in Example 1 except for using 40 mol% of succinic acid.

Comparative Example  2

The procedure of Comparative Example 1 was repeated except that adipic acid was used instead of succinic acid.

division fatty acid content
(%) inherence
Viscosity Tg
(℃) Tm
(℃) hue
b Processability Degradability
(IV reduction rate,%) Example 1 Seosin acid 10 0.69 66 223 3.5 Radiable
Injection molding possible 13.6 Example 2 Seosin acid 20 0.71 48 191 5.0 Radiable
Injection molding possible 55.8 Example 3 Adipic acid 10 0.69 60 218 2.0 Radiable
Injection molding possible 15.4 Example 4 Adipic acid 20 0.70 45 204 3.5 Radiable
Injection molding possible 21.6 Comparative Example 1 Seosin acid 40 1.5 20 130 10 Non-radiative
Injection molding possible 75.4 Comparative Example 2 Adipic acid 40 1.4 20 140 7 Non-radiative
Injection molding possible 70.0

Property evaluation

The inherent viscosity of the biodegradable polyester according to the present invention was prepared by mixing phenol and trichloroethane in a ratio of 6: 4 by weight ratio at 25 ° C. to prepare a mixed solvent, and measuring the dissolved polyester using the glass transition. The temperature and melting point were analyzed using a differential calorimetry, and the color tone b was analyzed using a spectrophotometer named CM-3600d, manufactured by Konica Minolta, Japan.

Degradability measurement was analyzed by adjusting the intrinsic viscosity change by adjusting the distilled water pH to 7 to 8 and then hydrolysis at 100 ℃ for 24 hours.

The present invention can be used in the manufacture of biodegradable polyesters and in the manufacture of synthetic resin products and textile products which require biodegradability.

Claims (9)

Esterification and polycondensation of an aromatic acid comprising a phenylene group, an aliphatic acid containing carboxylic acid groups and an acid component comprising sodium 3,5-dicarbomethoxybenzenesulfonate, and a diol component having 2 to 14 carbon atoms Biodegradable polyester formed,
The biodegradable polyester comprises an acid component of 10-20 mol% of the aliphatic acid, 0.1-15 mol% of sodium 3,5-dicarbomethoxybenzenesulfonate and a residual amount of aromatic acid, and has an intrinsic viscosity ( IV) A biodegradable polyester having a hue b value of 0.6 to 0.7, a glass transition temperature (Tg) of 55 to 65 ° C, a melting point (Tm) of 191 to 223 ° C, and a color tone of 5 or less. The method of claim 1,
Biodegradable polyester, characterized in that the biodegradable polyester further comprises a complementary amount in the range of 60 to 130ppm based on the total weight of the polymer. The method of claim 1,
The aliphatic acid is oxalic acid (Oxalic acid), malonic acid (Malonic acid), succinic acid (Succinic acid), glutaric acid (Glutaric acid), adipic acid (subic acid), suberic acid (suberic acid), citric acid (Citric) acid, pimeric acid, azelaic acid, sebasic acid, nonanoic acid, decanoic acid, dodecanoic acid, hexano Biodegradable polyester, characterized in that it is selected from the group consisting of decanoic acid (Hexadecanoic acid) or a mixture of two or more thereof. The method of claim 1,
The aromatic acid is selected from the group consisting of terephthalic acid, isophthalic acid, dimethyl terephthalate, dimethyl isophthalate, or a mixture of two or more thereof. ester. The method of claim 1,
Ethylene Glycol, Propylene Glycol, Trimethyl Glycol, Tetramethylene Glycol, Pentamethyl Glycol, Hexamethylene Glycol having 2 to 14 carbon atoms Hexamethylene Glycol, Heptamethylene Glycol, Octamethylene Glycol, Nonamethylene Glycol, Decamethylene Glycol, Undecamethylene Glycol, Dodecamethylene Glycol Dodecamethylene Glycol), tridecamethylene glycol (Tridecamethylene Glycol), tetradecamethylene glycol (Tetradecamethylene Glycol) or a biodegradable polyester, characterized in that it is selected from the group consisting of two or more thereof. delete delete delete (1) The acid component comprising an aromatic acid containing a phenylene group, an aliphatic acid containing carboxylic acid groups and sodium 3,5-dicarbomethoxybenzenesulfonate, and a diol component having 2 to 14 carbon atoms. : Mix so that the ratio of the diol component is within the range of 1.0: 1.0 to 1.4 in molar ratio,
The acid component comprises 10 to 20 mol% of the aliphatic acid, 0.1 to 15 mol% of sodium 3,5-dicarbomethoxybenzenesulfonate and the remaining amount of aromatic acid,
An esterification step of preparing an oligomer while stirring at 200 to 240 ° C. for 150 to 190 minutes at a speed of 40 to 80 rpm; And
(2) a polymerization step of polymerizing the oligomer at 230 to 280 ° C. for 180 to 210 minutes at 40 to 100 rpm;
Method for producing a biodegradable polyester, characterized in that consisting of.