KR20120126936A - Method of manufacturing biodegradable polyester resin - Google Patents

Abstract

PURPOSE: A manufacturing method of a biodegradable polyester resin is provided to provide a polyester resin with excellent biodegradability, excellent thermal stability and mechanical strength, and excellent blow moldability. CONSTITUTION: A manufacturing method of a biodegradable polyester resin comprises a step of esterification reaction by dehydrating a mixture, which comprises a compound selected form an aliphatic dicarboxylic acid or cycloaliphatic dicarboxylic acid or ester-forming derivative thereof, aromatic dicarboxylic acid or a mixture of the ester-forming derivative, aliphatic diol, or a mixture thereof; a step of de-glycol reaction by putting a titanium catalyst into an oligomer obtained through the previous step; and a step of putting 1,3,5-triglycidyl isocyanurate and zinc magnesium or zinc oxide as a coupling agent into a polyester after the second step and conducting a reaction through a pressure reduction.

Description

Manufacturing method of biodegradable polyester resin {METHOD OF MANUFACTURING BIODEGRADABLE POLYESTER RESIN}

The present invention relates to a method for producing a biodegradable polyester resin, and more particularly to a method for producing a polyester resin having practical biodegradability and excellent mechanical properties such as tensile strength, elongation, and tensile modulus.

In general, polyester is very excellent in mechanical properties, chemical resistance, durability, etc. are used in everyday life as a natural fiber substitute material, but has a disadvantage that can not be reduced to nature when discarded after use. Disposable packaging materials that are consistently in demand are consumed, but they are often left untouched because their recovery is not made smoothly. Agricultural films are difficult to recover completely and are buried in soil, causing many problems in cultivating crops and causing environmental pollution. This situation is becoming.

As environmental pollution caused by such plastic wastes has emerged as a social problem, development of degradable resins that automatically decompose upon disposal after a certain period of time in order to protect the environment has been actively conducted.

Degradable resins are classified into biodegradable resins decomposed by microorganisms present in soil and photodegradable resins decomposed by ultraviolet rays of sunlight. However, the photodegradable resins developed to date have the disadvantage that they do not decompose when the film is buried in soil, and the biodegradable resins are polyhydroxyarylate resins and synthetic polymers synthesized in vivo by microorganisms. Polycaprolactone, which is a system biodegradable resin, is excellent in degradability but has a disadvantage in that it is economically expensive due to high manufacturing cost and weak application property, and thus its practical value is low.

For example, conventionally, the production of high molecular weight polymers by ring-opening polymerization of caprolactone is known, and the production of petrochemical products, films, and molded products using biodegradable aliphatic polyester is steadily increasing. However, in this case, due to the disadvantage that the final produced polymer has a low melting point of about 62 ° C. and high cost in production, it is only used for a limited use such as some medical fibers. It is not widely used in household products, etc. This is due to the disadvantage that the decomposition temperature of these polymers is similar to the melting point, thereby resulting in inadequate molding tendency and low mechanical strength such as tensile / tension strength.

Such conventional biodegradable resins include degradable resins copolymerized with aliphatic polyesters to natural polymers (Korean Patent No. 95-18124), degradable resins containing inorganic fillers (Republic of Korea Patent No. 96-22744), biodegradable Polyester containing a ketone group to impart photodegradability to an aliphatic polyester having a compound (Korean Patent No. 95-18116), a biodegradable resin containing starch in ethylene and an aliphatic polyester (Korean Patent No. 95-18214), Biodegradable resin (Republic of Korea Patent No. 95-10984) added with natural polymer, automatic oxidizer, photosensitizer, plasticizer, colorant, etc., based on thermoplastic resin, heterocylic to low molecular weight polyester with lactic acid as the main repeating unit Biodegradable polyester (Korean Patent No. 95-23663) which added chain extenders, such as a click compound, microbial synthetic aliphatic polyester And it may be a chemical synthetic co-polymer (Republic of Korea Patent Publication No. 96-22669), of an aliphatic polyester.

However, the above technique is uneconomical due to the low production yield in the production process by microbial fermentation, and furthermore, the melting point and the decomposition temperature are similar, causing difficulty in molding. In addition, although biodegradable polymers such as starch introduced into general synthetic polymers have been introduced, they may be referred to as biodegradable polymers rather than strictly biodegradable polymers in terms of being split into pieces by starch decomposition.

Therefore, in order to prevent environmental pollution and practicality, it is required to develop a polyester having excellent thermal stability and mechanical strength while being easily decomposed by microorganisms.

The present invention was derived to solve the above problems, and provides a method for producing a biodegradable polyester resin that is practical and excellent in biodegradability, has excellent thermal stability and mechanical strength, and obtains excellent blow moldability. For the purpose.

The thermal stability and the mechanical strength characteristics were extended by using a mixture of α-triglycidyl isocyanurate and β-triglycidyl isocyanurate and solved a problem of blow moldability.

As a means for solving the object as described above, the present invention is S1) aliphatic dicarboxylic acid or cycloaliphatic dicarboxylic acid or ester-forming derivative thereof 10 to 60% by weight, aromatic dicarboxylic acid or ester- A mixture of 20 to 70% by weight of the derivative formed; And esterifying the mixture comprising 20 to 60% by weight of any one of aliphatic diols or mixtures thereof by dehydration reaction in a nitrogen stream at 180 to 230 ° C. S2) after the dehydration reaction, to 100 parts by weight of the oligomer obtained in step S1), 0.6 ~ 1.0 parts by weight of titanium catalyst to the deglycol reaction at 230 ~ 250 ℃; And, S3) 1 to 15 parts by weight of magnesium oxide or zinc oxide as a coupling agent, and 5 to 10 parts by weight of 1,3,5-triglycidyl isocyanurate based on 100 parts by weight of polyester after step S2). It provides a method for producing a biodegradable polyester resin comprising; and the step of reacting under reduced pressure at 250 ~ 270 ℃.

The 1,3,5-triglycidyl isocyanurate is preferably a mixture of α-triglycidyl isocyanurate and β-triglycidyl isocyanurate, and α-triglycol. It is more preferable that the cylyl isocyanurate and the β-triglycidyl isocyanurate have a mixing ratio of 70 to 80 wt%: 20 to 30 wt%.

The aliphatic dicarboxylic acid or cycloaliphatic dicarboxylic acid or ester-forming derivative thereof is adipic acid and sebacic acid, and the mixing ratio thereof is preferably adipic acid: sebacic acid = 1: 0.5 to 1.5.

The aromatic dicarboxylic acid or ester-forming derivative thereof may be any one or a mixture of terephthalic acid, isophthalic acid, 2,6naphthalic acid and 1,5-naphthalic acid.

The aliphatic diols are 1,3-butanediol, 2-methyl-1,2-propanediol, 2-methyl-1,3-propanediol, 1,2-pentanediol, 1,4-pentanediol, 2,3- Pentanediol, 2,4-pentanediol, 2-methyl-2,4-pentanediol, 1,2-hexanediol, 1,3-hexanediol, 1,5-hexanediol, 2,3-hexanediol, 2 , 4-hexanediol, 2,5-hexanediol, 3,4-hexanediol, 1,2-heptanediol, 1,3-heptanediol, 1,4-heptanediol, 1,7-heptanediol, 2, Preferred is any one of 3-heptane diol, 2,5-heptane diol, 2,6-heptane diol, 3,4-heptane diol, 3,5-heptane diol or a mixture of two or more thereof.

According to the present invention, in the production of conventional biodegradable polyester, it is possible to solve the problem that the biodegradability is significantly reduced as the molecular weight of the homopolymer is increased, and in the case of the biodegradable polyester according to the present invention, the number average molecular weight As this polymer of 80,000 or more, since dicarboxylic acid, aromatic dicarboxylic acid, and 1,3,5 triglycidyl isocyanurate are mixed, it is suitable for manufacture into a molded object, and excellent mechanical strength can be obtained.

Hereinafter, embodiments will be described in detail so that those skilled in the art may easily implement the present invention.

The present invention provides a mixture of S1) aliphatic dicarboxylic acid or cycloaliphatic dicarboxylic acid or its ester-forming derivative 10 to 60% by weight, aromatic dicarboxylic acid or its ester-forming derivative 20 to 70% by weight; And esterifying the mixture comprising 20 to 60% by weight of any one of aliphatic diols or mixtures thereof by dehydration reaction in a nitrogen stream at 180 to 230 ° C. S2) after the dehydration reaction, to 100 parts by weight of the oligomer obtained in step S1), 0.6 ~ 1.0 parts by weight of titanium catalyst to the deglycol reaction at 230 ~ 250 ℃; And, S3) 1 to 15 parts by weight of magnesium oxide or zinc oxide as a coupling agent, and 5 to 10 parts by weight of 1,3,5-triglycidyl isocyanurate based on 100 parts by weight of polyester after step S2). It provides a method for producing a biodegradable polyester resin comprising; and the step of reacting under reduced pressure at 250 ~ 270 ℃.

The aliphatic dicarboxylic acids generally have 2 to 10, preferably 4 to 6 carbon atoms. They can be linear and branched. On the other hand, the cycloaliphatic dicarboxylic acids of the present invention are those having generally 7 to 10 carbon atoms, preferably having 8 carbons. However, it is generally also possible to use dicarboxylic acids having a larger number of carbon atoms, for example up to 30 carbon atoms.

As an example, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, azelaic acid, sebacic acid, fumaric acid, 2,2-dimethylglutaric acid, suberic acid, 1,3-cyclopentanedicarboxyl Acids, 1,4-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, diglycolic acid, itaconic acid, maleic acid and 2,5-norbornanedicarboxylic acid, of which adipic Acids or sebacic acids are preferred.

The ester-forming derivatives of the aliphatic or cycloaliphatic dicarboxylic acids mentioned above are di-C 1 -C 6 -alkyl esters, for example dimethyl, diethyl, di-n-propyl, diisopropyl, di-n- Butyl, diisobutyl, di-t-butyl, di-n-pentyl, diisopentyl or di-n-hexyl ester. Similarly, it is also possible to use anhydrides of dicarboxylic acids.

It is also possible to use dicarboxylic acids or their ester-forming derivatives alone or in mixtures of two or more thereof.

Preferably, adipic acid or its ester-forming derivatives alone or sebacic acid or its ester-forming derivatives alone or a mixture of adipic acid and sebacic acid or its ester-forming derivatives can be used, in particular, Adipic acid or its ester-forming derivatives can be used alone.

The aromatic dicarboxylic acids are those having 8 to 12, preferably 8 carbon atoms.

Examples thereof are terephthalic acid, isophthalic acid, 2,6-naphthalic acid and 1,5-naphthalic acid, and ester-forming derivatives thereof. In particular, di-C 1 -C 6 -alkyl esters such as dimethyl, diethyl, di-n-propyl, diisopropyl, di-n-butyl, diisobutyl, di-t-butyl, di-n- Mention may be made of pentyl, diisopentyl or di-n-hexyl ester. Anhydrides of dicarboxylic acids may likewise be suitable ester-forming derivatives. In the present invention, terephthalic acid or ester forming derivatives thereof, in particular dimethyl ester, or mixtures thereof are preferred.

It is also generally possible to use aromatic dicarboxylic acids having a large number, for example up to 20 carbon atoms.

In the case of the aliphatic alcohol, it is generally possible to use all aliphatic polyhydric alcohols capable of forming dicarboxylic acids or esters.

Generally, branched or linear alkanediols having 2 to 12, preferably 4 to 6 carbon atoms, or cycloalkanediols having 5 to 10 carbon atoms, polyetherdiols, ie containing ether groups Dihydroxy compounds can be used.

Examples of suitable alkanediols include 1,3-butanediol, 2-methyl-1,2-propanediol, 2-methyl-1,3-propanediol, 1,2-pentanediol, 1,4-pentanediol, 2, 3-pentanediol, 2,4-pentanediol, 2-methyl-2,4-pentanediol, 1,2-hexanediol, 1,3-hexanediol, 1,5-hexanediol, 2,3-hexanediol , 2,4-hexanediol, 2,5-hexanediol, 3,4-hexanediol, 1,2-heptanediol, 1,3-heptanediol, 1,4-heptanediol, 1,7-heptanediol, 2,3-heptane diol, 2,5-heptane diol, 2,6-heptane diol, 3,4-heptane diol, 3,5-heptane diol, or a mixture of two or more thereof.

 Examples of polyetherdiols include diethylene glycol, triethylene glycol, polyethylene glycol, polypropylene glycol, polytetrahydrofuran, in particular diethylene glycol, triethylene glycol, polyethylene glycol, or mixtures thereof, or different numbers of ether units. It may be a compound having a propylene unit, for example polyethylene glycol obtained by first polymerizing ethylene oxide by a conventional method and then polymerizing propylene oxide. The molecular weight (Mn) of polyethylene glycol which can be used is generally about 500 to about 9,000 g / mol, preferably 1000 to 7,000 g / mol. Mixtures of different polyetherdiols can likewise be used.

The present invention provides a mixture of 10 to 60% by weight of the aliphatic dicarboxylic acid or cycloaliphatic dicarboxylic acid or ester-forming derivative thereof, 20 to 70% by weight of aromatic dicarboxylic acid or ester-forming derivative thereof; And, the mixture consisting of 20 to 60% by weight of any one of aliphatic diol or a mixture thereof is subjected to an esterification reaction by a dehydration reaction in a nitrogen stream at 180 ~ 230 ℃. Thereafter, with respect to 100 parts by weight of the oligomer obtained after the esterification reaction, 0.6 to 1.0 parts by weight of titanium catalyst is added to undergo a deglycol reaction at 230 to 250 ° C. to obtain a polyester.

Tetrabutyl titanate may be used as a titanium compound which is a reaction accelerator added to promote a deglycol reaction during the esterification reaction, and the amount of the compound is 0.6 to 1.0 parts by weight, preferably 100 parts by weight of the oligomer. 0.7 to 0.85 parts by weight is suitable. If the amount of the titanium catalyst is less than 0.6 parts by weight does not have a significant effect on the reaction rate, if it exceeds 1.0 parts by weight because it does not contribute to the actual reaction rate.

After passing through the deglycol reaction, 1 to 15 parts by weight of magnesium oxide or zinc oxide was added as a coupling agent to 100 parts by weight of polyester obtained at 250 to 270 ° C, and at the same time, 1,3,5-triglycis 5 to 10 parts by weight of dill isocyanurate is added.

The 1,3,5-triglycidyl isocyanurate (TGIC) is used as a curing agent for molding, adhesives, and powder paints, and has excellent heat resistance, It is applied to the compound field because of excellent physical properties such as weather resistance. It is also widely used in optics and electronics due to its excellent transparency and conductivity. In addition, triglycidyl isocyanurate consists of a pair of stereoisomers, with α- and β-forms, with α-forms facing away from one of the epoxy groups and β-forms having three epoxy groups. Facing the same direction. This is shown in Formula 1 below.

[Formula 1]

The triglycidyl isocyanurate may prepare triglycidyl isocyanurate by reacting cyanuric acid and epichlorohydrin in the presence of a tetraalkylammonium chloride catalyst at 85 to 120 ° C. have.

In the present invention, it is preferable to use α- and β-type 1,3,5-triglycidyl isocyanurate, and the ratio is α-triglycidyl isocyanurate and β-triglycol. It is preferred that the cylyl isocyanurate has 70 to 80 wt%: 20 to 30 wt%. If the weight% of β-triglycidyl isocyanurate is less than 20%, there may be a decrease in mechanical properties, and if it exceeds 30% by weight, biodegradability may be reduced. On the other hand, since it has a melting point of 92 to 115 ° C on average in the above numerical range, blow molding may be easy, and at a temperature below that, the mechanical properties are excellent.

It is preferable to use magnesium oxide or zinc oxide as the coupling agent, and 1 to 15 parts by weight, preferably 5 to 10 parts by weight, based on 100 parts by weight of polyester obtained after the deglycol reaction is used. proper. When the coupling agent is less than 1 part by weight, it is difficult to form a polymer having a large average molecular weight. When the coupling agent exceeds 15 parts by weight, there is a problem that a phenomenon of gelation may be caused.

Hereinafter, the configuration and effect of the present invention will be described in more detail with reference to Examples and Test Examples. However, the embodiments are only examples for explaining the configuration of the present invention, and the scope of the present invention is not limited to these embodiments.

≪ Example 1 >

In a 250 mL hard glass four-necked separating flask equipped with a low boiling point compound outlet tube such as a stirrer, a gas inlet tube, water, and a thermometer equipped with a thermometer, 35 g of adipic acid, 35 g of terephthalic acid, and 30 g of 1,3-butanediol were added. After the addition, the temperature was adjusted to 200 ° C. to effect esterification by dehydration in a nitrogen stream.

After the outflow of water was completed, 0.7 g of titanium was added to the resulting oligomer as a deglycol catalyst under a nitrogen atmosphere, and the temperature of the reactor was raised to 240 deg.

To the resultant polyester, 7 g of α-triglycidyl isocyanurate and β-triglycidyl isocyanurate were added in a ratio of 70% by weight to 30% by weight, and 7g of zinc oxide was added thereto. The reaction was carried out under reduced pressure at 260 ° C. under a nitrogen atmosphere.

The number average molecular weight (Mn) of the obtained polyester resin was 85,000, and the weight average molecular weight (Mw) was 215,000, melting | fusing point was 62 degreeC, and the softening point was 59 degreeC.

<Example 2>

Example 1, except that 7 g of α-triglycidyl isocyanurate and β-triglycidyl isocyanurate were added at a ratio of 80% by weight to 20% by weight. A polyester resin was prepared under the same condition as the above, and the obtained resin had a number average molecular weight (Mn) of 80,000, a weight average molecular weight (Mw) of 205,000, a melting point of 65 ° C and a softening point of 60 ° C.

&Lt; Comparative Example 1 &

A polyester resin was prepared under the same conditions as in Example 1, except that 7 g of α-triglycidyl isocyanurate was added in Example 1, and the number average molecular weight (Mn) of the obtained resin was 55,000, and a weight average. The molecular weight (Mw) was 175,000, the melting point was 53 ° C, and the softening point was 49 ° C.

Comparative Example 2

In Example 1, a polyester resin was prepared under the same conditions as in Example 1 without adding a coupling agent. The number average molecular weight (Mn) of the obtained resin was 16,000, the weight average molecular weight (Mw) was 95,000, and the melting point was 43 ° C. , Softening point was 40 ° C.

<Test Example 1> Physical property evaluation

Physical properties of the polyester resins obtained in Examples 1 and 2 and Comparative Examples 1 and 2 were measured at room temperature in accordance with KSM3006 regulations, and the results are shown in Table 1.

Tensile Strength (MPa) Elongation (%) Tensile Modulus (MPa) Example 1 58 760 782 Example 2 52 750 815 Comparative Example 1 45 620 791 Comparative Example 2 28 550 1252

As can be seen in Table 1, when the resin was prepared by adjusting triglycidyl isocyanurate as 70 wt%: 30 wt%, 80 wt%: 20 wt% of α- and β-types as mechanical properties It was confirmed that the tensile strength and elongation were excellent.

The above description is merely illustrative of the technical idea of the present invention, and those skilled in the art to which the present invention pertains may make various modifications and changes without departing from the essential characteristics of the present invention. Therefore, the embodiments disclosed in the present invention are intended to illustrate rather than limit the scope of the present invention, and the scope of the technical idea of the present invention is not limited by these embodiments. The scope of protection of the present invention should be construed according to the following claims, and all technical ideas falling within the scope of the same shall be construed as falling within the scope of the present invention.

Claims (5)

S1) a mixture of 10 to 60% by weight of aliphatic dicarboxylic acid or cycloaliphatic dicarboxylic acid or ester-forming derivative thereof, 20 to 70% by weight of aromatic dicarboxylic acid or ester-forming derivative thereof; And esterifying a mixture comprising 30 to 60% by weight of any one of aliphatic diols or mixtures thereof by dehydration reaction in a nitrogen stream at 180 to 230 ° C;
S2) after the dehydration reaction, to 100 parts by weight of the oligomer obtained in step S1), 0.6 ~ 1.0 parts by weight of titanium catalyst to the deglycol reaction at 230 ~ 250 ℃; And,
S3) 1 to 15 parts by weight of magnesium oxide or zinc oxide, and 5 to 10 parts by weight of 1,3,5-triglycidyl isocyanurate as a coupling agent, based on 100 parts by weight of polyester after step S2). Method of producing a biodegradable polyester resin comprising; reacting by reducing the pressure at 250 ~ 270 ℃. The method of claim 1,
The 1,3,5-triglycidyl isocyanurate has an α-triglycidyl isocyanurate and β-triglycidyl isocyanurate in a ratio of 70 to 80 wt%: 20 to 30 wt% Method for producing a biodegradable polyester resin, characterized in that consisting of. The method of claim 1,
The aliphatic dicarboxylic acid or cycloaliphatic dicarboxylic acid or ester-forming derivative thereof is adipic acid and sebacic acid, and the mixing ratio thereof is adipic acid: sebacic acid = 1: 0.5-1.5 Process for producing ester resin. The method of claim 1,
The aromatic dicarboxylic acid or its ester-forming derivative is a method for producing a biodegradable polyester resin, characterized in that any one or a mixture of terephthalic acid, isophthalic acid, 2,6 naphthalic acid and 1,5-naphthalic acid. . The method of claim 1,
The aliphatic diols are 1,3-butanediol, 2-methyl-1,2-propanediol, 2-methyl-1,3-propanediol, 1,2-pentanediol, 1,4-pentanediol, 2,3- Pentanediol, 2,4-pentanediol, 2-methyl-2,4-pentanediol, 1,2-hexanediol, 1,3-hexanediol, 1,5-hexanediol, 2,3-hexanediol, 2 , 4-hexanediol, 2,5-hexanediol, 3,4-hexanediol, 1,2-heptanediol, 1,3-heptanediol, 1,4-heptanediol, 1,7-heptanediol, 2, Biodegradable polyester, characterized in that any one or a mixture of two or more of 3-heptane diol, 2,5-heptane diol, 2,6-heptane diol, 3,4-heptane diol, 3,5-heptane diol Method for producing a resin.