KR19980073759A - High strength biodegradable polyester resin and its manufacturing method - Google Patents

Abstract

The present invention provides a high strength biodegradable polyester resin polymerized by mixing 0.01 to 1.0% by weight of a compound of formula 1 as an additional component with one or two or more aliphatic polyester resin components, based on the total mixture.

[Formula 1]

Wherein R1, R2, R3 are the same or different groups selected from OH or COOH

Description

High strength biodegradable polyester resin and its manufacturing method

The present invention relates to biodegradable polyester resins, and more particularly to biodegradable polyesters of high strength.

Recently, as one of the ways to solve the problem of waste plastic, which is one of the environmental problems, interest in the study of biodegradable polymers is increasing, and representative biodegradable polymers are aliphatic polyesters (Korean Patent Publication No. 94-14497). And 95-758 and the like). However, aliphatic polyester has excellent biodegradability but has a disadvantage of poor mechanical properties such as being easily torn, thereby greatly limiting the scope of application.

As a method for improving the tear resistance of the aliphatic polyester resin, the following two methods can be considered. One method is to mix a small amount of good tear-resistant polymer and make it tear resistant by physical bonding, and the other method is to chemically bond to aliphatic polyester resin by mixing a good tearing compound in the polymerization step and tearing steel It is a way to increase the degree.

In the former case, a tear resistant biodegradable aliphatic polyester having various phase separation structures depending on the temperature and composition at the time of blending is blended with a polymer having excellent tear resistance to the aliphatic polyester, and the interface adhesion and compatibility of the phase separation structure are commercialized. It can be adjusted by the addition.

On the other hand, in the latter case, since the chemical bond between the aliphatic polyester resin and the modifying component must be induced, the modifying component must have a functional group capable of chemically reacting with the aliphatic diol and aliphatic dieside or an ester compound thereof, preferably an aliphatic compound. Aromatic compounds that are more advantageous for improving tear strength will be suitable.

This invention aims at improving the physical property of a biodegradable aliphatic polyester by the latter method, and aims at providing the high strength biodegradable polyester resin especially improved tear resistance.

According to the present invention for achieving the above object, high-strength biodegradation, characterized in that the compound of formula (1) as an additional component to one or two or more aliphatic polyester resin component is polymerized by mixing 0.01 to 1.0% by weight based on the total mixture A polymeric polyester resin is provided.

[Formula 1]

Wherein R 1, R 2, R 3 are the same or different groups selected from OH or COOH.

In addition, according to the present invention, one or two or more aliphatic polyester resin components are mixed with some of the compounds of the formula (1) as additional components to completely melt them, and the condensation reaction is selectively performed only between the aliphatic polyester resin components and the additional components. High-intensity biodegradation, characterized in that the addition of the remaining compound of the formula (1) and condensation polymerization, so that the compound of formula (1) added to the total reaction is 0.01 to 1.0% by weight based on the total amount of the aliphatic polyester resin component and the additional component There is provided a process for the preparation of a polyester resin.

Hereinafter, the present invention will be described in more detail.

The high strength biodegradable polyester resin according to the present invention has a form in which an aliphatic diol, an aliphatic dieside or an ester compound thereof and an aromatic compound of the formula (1) are polymerized into a linear, branched or meshed form.

The aromatic compound of the formula (1) is bound to the molecular chain of the polymer due to the properties of the benzene ring to give an increase in strength, and because it is trifunctional, the branching or mesh-like structure of the polymer is effective to further improve the strength have. However, if the area of the polymer occupied by the aromatic compound of Formula 1 is large, the biodegradability is low or almost absent, so it is important to maintain the content at a considerably lower content than the aliphatic monomer. Therefore, according to the present invention, the content of the aromatic compound of the general formula (1) as an additional component is limited to 0.01 to 1.0% by weight based on the total amount of the aliphatic polyester resin component and the additional component. If the upper limit of the above range is exceeded, there is a problem that the biodegradability is lowered, and below the lower limit, the strength improvement effect is insignificant. In addition, in the following examples, the compounds of Formula 1 are exemplified only for R1, R2, and R3, all of which are OH or COOH, but if one of ordinary skill in the art, only two of R1, R2, and R3 are the same or respectively. It will be appreciated that other things can be readily applied.

In addition, the aliphatic diol used as an aliphatic polyester resin component in this invention, and an aliphatic dieside or its ester compound may use the conventional compound well-known in connection with manufacture of a well-known biodegradable aliphatic polyester resin.

In the preparation of the polymer according to the present invention, the condensation reaction is carried out selectively only between the aliphatic polyester resin component and some additional components, followed by further addition and condensation polymerization of the remaining compound of formula (1). It is preferable to satisfy all of the strength reinforcement.

In the selective condensation reaction, calcium triacetate may be used as a catalyst, cobalt acetate as a colorant, phosphoric acid as a heat stabilizer, and antimontriacetate, stabilizer, benzeneacetic acid, titanium dioxide, etc. may be added as a catalyst in the polycondensation reaction. And the reaction may proceed under reduced pressure.

Features and other advantages of the present invention as described above will become more apparent from the embodiments described below. The following examples are intended to illustrate the invention but not to limit it.

<Example 1>

In addition to the aliphatic polyester resin component consisting of a 1: 2 molar ratio mixture of ethylene glycol and succinic acid, 1,2,4-trihydroxybenzene was mixed as an additional ingredient in the amounts shown in Table 1 below, and completely melted. 400 ppm of acetate, 60 ppm of cobalt acetate as a colorant, and 150 ppm of phosphoric acid as a heat stabilizer were added to allow selective condensation reaction between the aliphatic polyester resin component and the compound of formula (1). To the resultant condensation reaction product, 1,2,4-trihydroxybenzene was further added at the dosage shown in Table 1 below, and about 400 ppm of antimontriacetate was added as a catalyst, and the shaft was reduced under a reduced pressure of 0.3 mmHg at a polymerization temperature of 280 ° C. The polymerization was carried out to obtain a polymer having an intrinsic viscosity of 0.620 (dl / g) and a molecular weight distribution of 3.0. The tear strength and biodegradability of the obtained polymer were measured and the results are shown in Table 1 below. Biodegradability was measured by weight loss after 30 days of caustic embedding.

<Examples 2 to 6>

The same procedure as in Example 1 was repeated except that the kinds of additional ingredients and the dosages of the selective condensation reaction step and the polycondensation step were changed as shown in Table 1 below.

<Comparative Example 1>

A polymer was prepared using a 1: 2 mixture of the same aliphatic diols and aliphatic diesides or ester compounds thereof as in Example 1 without using the compound of Formula 1. The tear strength and biodegradation of the prepared polymers were measured and the results are shown in Table 1 below.

TABLE 1

division Kinds and dosages of tear-resistant compounds (wt%) Tear strength (kg / ㎡) Biodegradability (%) Kinds Total input Example 1 1,2,4-trihydroxybenzene 0.1 500 90 Example 2 1,2,4-trihydroxybenzene 0.5 800 80 Example 3 1,2,4-trihydroxybenzene 1.0 900 80 Example 4 Benzene-1,2,4-tricarboxylic acid 0.1 700 80 Example 5 Benzene-1,2,4-tricarboxylic acid 0.5 900 70 Example 6 Benzene-1,2,4-tricarboxylic acid 1.0 1200 70 Comparative Example 1 - - 200-400 90

As can be seen from Table 1, according to the present invention, it is possible to provide a biodegradable resin having significantly improved tear strength as compared with a biodegradable aliphatic polyester.

Claims (2)

A high strength biodegradable polyester resin, characterized in that the compound of formula (1) is mixed with one or two or more aliphatic polyester resin components as an additional component, 0.01 to 1.0% by weight based on the total mixture. One or two or more aliphatic polyester resin components are mixed with some of the compounds of the formula (1) as additional components to completely melt and selectively undergo condensation reaction only between the aliphatic polyester resin components and the additional components, and then Preparation of a high-strength biodegradable polyester resin, characterized in that the addition of the compound and the polycondensation, so that the compound of formula (1) added to the total reaction is 0.01 to 1.0% by weight based on the total amount of the aliphatic polyester resin component and additional components. Way.