KR20160052848A - Biodegradable Polyester Resin Composition and Biodegradable Polyester Foamed Article Therefrom - Google Patents

Abstract

The present invention relates to a biodegradable polyester resin composition, and a biodegradable polyester foamed product produced therefrom. The oxidation biodegradable polyester foamed product according to the present invention is produced by injecting and forming a forming agent in the oxidation biodegradable polyester resin composition produced by melting and mulling 100 parts by weight of a polyester resin consisting of polyethylene terephthalate, polybutylene terephthalate, or a mixture thereof and 0.05 to 10 parts by weight of oxidation biodegradable materials. In the oxidation biodegradable polyester foamed product according to the present invention, specific gravity is in the range of 70 to 120 kg/m^3, and compressive strength is in the range of 0.8 to 1.5 MPa.

Description

[0001] The present invention relates to a biodegradable polyester resin composition and a biodegradable polyester foam composition prepared therefrom,

The present invention relates to a biodegradable polyester resin composition. More specifically, the present invention relates to a polyester resin composition which is free from changes in physical properties and capable of oxidative biodegradation. The present invention also includes a foam prepared by foaming the biodegradable polyester resin composition of the present invention.

Polyethylene terephthalate, polybutylene terephthalate and the like are used in various fields such as beverage bottles, packaging films, textile products and electronic products due to their light specific gravity, excellent strength and transparency. However, these polyester products are becoming serious environmental problems after disposal.

At present, recycling is the most useful method for post-use treatment of polyester resin moldings, but recycling is not a fundamental solution because the fields to be recycled are limited and must be ultimately discarded. In addition, incineration of a molded product of a polyester resin causes toxic gas to be generated, and biodegradation does not occur when it is buried, adversely affecting the environment.

As a result of active research on biodegradable polymers, biodegradable polymers such as aliphatic polyesters, starch polymers, cellulose acetate, polyhydroxybutyrate, polylactide, polycaprolactone and polybutylene succinate have been commercialized And is commercially available. Among them, polylactic acid resin, which is one of the biodegradable polyesters, is easily broken in the case of thin film products due to lack of moldability, mechanical strength and heat resistance, and when the external temperature rises by 60 ° C or more due to low temperature resistance, There is a problem that deformation occurs.

Korean Patent No. 72815 discloses a biodegradable resin foam obtained by adding polylactic acid to a wax and / or a polyolefin resin, and a biodegradable resin molding container. Korean Patent No. 36905 discloses a biodegradable resin comprising polylactic acid and an acrylic ester compound And biodegradable resins and foams using biodegradable resins. However, since the biodegradable resin is a polylactic acid, its physical properties remain unchanged.

Accordingly, the present inventors have developed a polyester resin composition which is excellent in oxidative biodegradability and has no change in physical properties by melt-kneading polyester and oxidative biodegradation materials, and a foam prepared therefrom, in order to fundamentally solve the above problems.

An object of the present invention is to provide a biodegradable foam produced by foaming a biodegradable polyester resin composition.

These and other objects of the present invention can be achieved by the present invention described in detail below.

The oxidative biodegradable polyester foam according to the present invention is a biodegradable biodegradable polyester foam obtained by melt kneading 100 parts by weight of a polyester resin composed of polyethylene terephthalate, polybutylene terephthalate or a mixture thereof and 0.05 to 10 parts by weight of an oxidative biodegradable material The foaming agent is added to the polyester resin composition and foamed to have a specific gravity of 70 to 120 kg / m < 3 >, and a compressive strength of 0.8 to 1.5 MPa.

[5] The biodegradation material of claim 1, wherein the biodegradable material is a carboxylic acid metal salt, a transition metal complex, or a mixture thereof.

The oxidative biodegradable polyester resin composition may further comprise a silane compound as a photochemical crosslinking agent.

The foaming agent added to the polyester resin composition is preferably at least one selected from the group consisting of pentane, carbon dioxide, ADCA, and PTSS.

In addition to the foaming agent, a chemical foaming agent selected from the group consisting of oxobisbenzenesulfonylhydro azide, toluenesulfonyl semicarbazide, and calcium carbonate may be further included.

The oxidized biodegradable polyester resin composition of the present invention may further comprise a low molecular weight hydrocarbon blowing agent of propane or butane and a low boiling organic solvent blowing agent of methylene chloride in addition to the blowing agent.

Hereinafter, the present invention will be described in detail.

The present invention provides a polyester resin composition having a biodegradable effect while maintaining the basic physical properties of the polyester resin, and has the effect of providing the biodegradable foam by foaming the biodegradable polyester resin composition.

TECHNICAL FIELD The present invention relates to a biodegradable polyester resin composition, and relates to a polyester resin composition capable of biodegrading by oxidation without changing physical properties. The present invention also includes a foam prepared by foaming the biodegradable polyester resin composition of the present invention.

The oxidative biodegradable polyester resin composition according to the present invention is characterized in that it is produced by melt kneading 100 parts by weight of at least one polyester resin selected from polyethylene terephthalate and polybutylene terephthalate and 0.05 to 10 parts by weight of oxidative biodegradation material do.

The polyester polyester resin used in the present invention preferably has an intrinsic viscosity of 1.0 to 2.0 dl / g, preferably 1.4 to 1.8 dl / g.

In order to impart oxidative biodegradability to the polyester resin composition, 0.05 to 10 parts by weight of an oxidative biodegradation substance may be added to 100 parts by weight of the polyester resin. If the oxidative biodegradation material is less than 0.05 part by weight, the oxidative biodegradability of the final molded product is lowered, whereas if it exceeds 10 parts by weight, the compressive strength of the final molded product is lowered.

The oxidative biodegradation material is preferably composed of a carboxylic acid metal salt, a transition metal complex, or a mixture thereof.

The carboxylic acid metal salt may contain a metal selected from the group consisting of zinc, sodium, cobalt, iron, copper, manganese, vanadium, chromium, cerium, scandium, titanium, nickel and the like. The carboxylic acid includes formic acid, acetic acid, Oleic acid, erucic acid, linolic acid, maleic acid, succinic acid, and the like.

The transition metal complex can be selected from the group of zinc, sodium, cobalt, iron, copper, manganese, sodium, chromium, cerium, scandium, titanium, nickel and mixtures thereof.

The present invention includes a foam obtained by foaming a polyester resin composition of the present invention containing a foaming agent. The liquid foaming agent usable as the foaming agent is selected from the group consisting of hydrocarbons such as isopentane, pentane, hexane, heptane and octane, unsaturated hydrocarbons such as pentene, 4-methylpentene, hexene or petroleum ether fractions, ethers such as diethylether, alcohols such as methanol and ethanol, , And halogenated hydrocarbons such as carbon tetrachloride, chloroform, ethylene dichloride, methylene chloride, or 1,1,2-trichloro-1,2,2, -trifluoroethane. Other usable foaming agents include chemical foaming agents which decompose at high temperatures to release gases such as azodicarbonamide, P-toluenesulfonyl hydrazide, dinitrosopentamethylene, a mixture of sodium bicarbonate and citric acid, , Various hydrated aluminas such as aluminum trihydrate, sodium borohydride, and the like. The foaming agent is mixed in an amount of from about 0.05 to about 55% based on the polyester, and a combination of two or more foaming agents or any suitable compound is possible, and is not limited to the foaming agent.

A method for producing a polyester foam obtained by foaming a polyester resin according to the present invention is as follows. First, 1 part by weight of an oxidative biodegradation material is blended with 100 parts by weight of a polyester resin having an intrinsic viscosity of 1.0 to 2.0 dl / g, and the blend is fed to a hopper of an extruder. The foaming agent containing pentane is fed through the blowing agent injection port at a concentration of 5 to 7 parts by weight based on 100 parts by weight of the resin formulation. The temperature of the extruder region just before the point where the foaming agent enters may be maintained at about 280 ° C. It is advantageous to use a liquid foaming agent when introduced into an extrusion cylinder because it is easier to pump the liquid at a constant pressure and capacity than at a constant pressure and capacity. The molten polymer and blowing agent are thoroughly mixed and the molten mixture is discharged through a pelletizer with perforated die of the size of the desired extrudate bead diameter. The extrudate is immediately cut on the die surface by a high-speed rotating blade. Since the cut extrudate is immediately cooled and solidified by the cooling water, the bead is not inflated by the foaming agent, and the bead shape is maintained under a constant pressure. The extruded beads are put into a molding mold of a certain type, heated to a proper foaming temperature, and the crosslinked foamable polyester beads are discharged to a low-pressure region and expanded to form foam beads, whereby a foamed foam capable of oxidative biodegradation can be obtained. The oxidative biodegradable foamed polyester foam may be prepared in the form of a bead, and may be produced in the form of a sheet or rod through a slit die.

A cross-linking agent may be used so that the free radicals generated in the polymer chain can be bonded using the silane compound together with the polyester resin. The amount of the silane compound is not an important factor and can be widely varied depending on, for example, the type of polyester resin, the degree of desired modification and the reaction conditions. Generally, the amount is from about 0.1 to about 50 parts by weight, preferably from about 0.3 to about 30 parts by weight, and most preferably from about 0.5 to about 10 parts by weight per 100 parts by weight of the polyester resin.

The oxidized biodegradable polyester resin composition of the present invention may contain other components such as fillers, antioxidants, antistatic agents, flame retardants, additives, nucleating agents, lubricants, foaming aids, colorants and antifouling agents. Further, the gas element may include nitrogen, argon, neon, and helium.

Typically, gaseous organic compounds are used to expand plastic materials. Most importantly, the refrigerant may be a mixture of two or more of these as halogen derivatives of methane or ethane. Other gaseous compounds that can be used include acetylene, ammonia, butadiene, butane, butene, carbon dioxide, nitrous oxide, cyclopropane, dimenylamine, 2-2-dimethylpropane, ethane, ethylene, isobutane, isobutylene, methane , Monomethylamine, propane, propylene and trimethylamine, and mixtures of two or more of the foregoing blowing agents.

All of the foregoing materials are included in the expanding medium, which is the nominal gas. The meaning of the term means that the expansion medium used is a gas at a temperature present in the normal operating state of the plastic extruder. In addition, in the introduction of a gas which enters a plastic compound in an expanding medium or an extruding cylinder, which is a conventional gas, the substance to be introduced is present as a gas at the normal operating temperature of the extruder, but the temperature and pressure May be in a gaseous or liquid state.

The present invention will be more clearly understood from the following preferred examples, which should not be construed as limiting or limiting the scope of protection of the present invention, but only for the purpose of illustrating the present invention.

Example

Example  One

10 kg of the high viscosity polyethylene terephthalate resin and 100 g of the oxidative biodegradation material were put into a super mixer, stirred and homogeneously mixed and then extruded at 250 to 290 ° C for melt kneading. At this time, pentane was introduced at a concentration of 5 parts by weight based on 100 parts by weight of the resin blend through a blowing agent inlet connected to the end of the extruder. An oxidatively decomposable polyethylene terephthalate resin was obtained in the form of a bead using a pelletizer directly connected to an extruder. The bead - shaped oxidatively degradable polyethylene terephthalate was foamed in a certain molding mold. The physical properties of the poly (ethylene terephthalate) foamed foam thus obtained were measured. In order to measure oxidative biodegradability, ultraviolet degradability was evaluated according to ASTM G154 method. After exposure for 12 days in ultraviolet light, the compressive strength was measured. The measurement results are shown in Table 1.

Example 2

A polyethylene terephthalate resin was obtained in the same manner as in Example 1, except that the blowing agent was controlled by controlling carbon dioxide.

Example 3

A polyethylene terephthalate resin was obtained in the same manner as in Example 1, except that the blowing agent was controlled by ADCA.

Example 4

A polyethylene terephthalate resin was obtained in the same manner as in Example 1, except that the foaming agent was controlled by PTSS.

Comparative Example 1

A polyethylene terephthalate resin was obtained in the same manner as in Example 1, except that no foaming agent was added.

Comparative Example 2

A polyethylene terephthalate resin was obtained in the same manner as in Example 1 except that the oxidative biodegradation material was not added.

Comparative Example 3

A polyethylene terephthalate resin was obtained in the same manner as in Example 1, except that no ferric oxide biodegradable material was added and the foaming agent was controlled by ADCA.

The results of the physical properties of the above Examples and Comparative Examples are shown in Table 1 below:

division Example Comparative Example One 2 3 4 One 2 3 Polyethylene terephthalate 100 100 100 100 100 100 100 Oxidative biodegradation substance Biosphere One One One One One Two components Pentane 5 5 carbon dioxide 5 ADCA 7 7 PTSS 7 Properties Foaming temperature 220 220 220 220 220 220 220 Polymer
characteristic Density (kg /) 82 76 87 90 130 84 85 Compressive strength (MPa) 1.1 0.95 0.97 0.90 1.0 0.95 0.92 Oxidative degradability Compressive strength (MPa) 0.21 0.19 0.30 0.24 0.31 0.86 0.90

As can be seen from the results of the above Table 1, the oxidative biodegradable polyethylene terephthalate foamed foam of Examples 1 to 4 had a density of 130 kg / m < 3 > or more in Comparative Example 1 which was not foamed at 80 to 90 kg / And it was confirmed that the oxidative biodegradation proceeded through a reduction in the range of 0.19 to 0.31 MPa in the range of the compressive strength of 0.9 to 1.1 MPa after 12 days of exposure to ultraviolet rays. On the other hand, in Comparative Examples 2 and 3 in which the oxidative biodegradation substance was not added, it was confirmed that the biodegradation did not progress through the difference in the compressive strength before and after the UV exposure.

It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

Claims (6)

A foaming agent is added to an oxidative biodegradable polyester resin composition prepared by melt kneading 100 parts by weight of a polyester resin comprising polyethylene terephthalate, polybutylene terephthalate, or a mixture thereof and 0.05 to 10 parts by weight of an oxidative biodegradable material, Wherein the specific gravity is in the range of 70 to 120 kg / m < 3 >, and the compressive strength is in the range of 0.8 to 1.5 MPa.
The oxidized biodegradable polyester foam according to claim 1, wherein the oxidative biodegradation material is a carboxylic acid metal salt, a transition metal complex, or a mixture thereof.
The oxidized biodegradable polyester foam according to claim 1, wherein the oxidative biodegradable polyester resin composition further comprises a silane compound as a photochemical crosslinking agent.
The oxidized biodegradable polyester foam according to claim 1, wherein the foaming agent is at least one selected from the group consisting of pentane, carbon dioxide, ADCA, and PTSS.
The oxidized biodegradable polyester foam according to claim 4, further comprising a chemical foaming agent selected from the group consisting of oxobisbenzenesulfonylhydroazide, toluenesulfonyl semicarbazide, and calcium carbonate in addition to the blowing agent .
The oxidized biodegradable polyester foam according to claim 4, further comprising, in addition to the blowing agent, a low molecular weight hydrocarbon blowing agent of propane or butane and a low boiling organic solvent blowing agent of methylene chloride.