Biodegradable thermoplastic resin composition made from non-edible biomass raw materials

Abstract

To provide a biodegradable resin composition excellent in physical characteristics using inedible biomass feedstock.SOLUTION: Cellulose acetate is used as a polymeric material made from inedible biomass feedstock, and cellulose acetate of 100 pts.wt. is mixed with a biodegradable compound that has been used as a plasticizer of cellulose acetate in the prior art in an amount greater than 40 pts.wt. and less than or equal to 80 pts.wt. so as to prepare biodegradable thermoplastic resin composition having high moldability into a sheet, film or fiber.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a biodegradable thermoplastic resin composition made from non-edible biomass raw materials. In the biodegradable thermoplastic resin composition according to the present invention, not only the resin component but also the plasticizer thereof uses a substance prepared from non-edible biomass raw materials.

Background Art

[0002] In recent years, in consideration of the environmental load, the demand for resins using natural product-derived components has been increasing. In particular, biodegradable resins such as polylactic acid (PLA)-based, polyhydroxyalkanoate (PHA)-based which is a biodegradable resin derived from microorganisms, and starch-based have been expected, and many research and developments have been conducted (Non-Patent Document 1, etc.).

Prior Art Documents

Non-Patent Documents

[0003]

Non-Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The above-mentioned biodegradable resins such as polylactic acid (PLA)-based, polyhydroxyalkanoate (PHA)-based, and starch-based are prepared from edible biomass raw materials such as taro, grains, sugarcane, corn, etc. and palm oil, and it has been suggested that they may compete with human food in the near future. Therefore, the present inventor has focused on biodegradable resins using non-edible biomass raw materials that do not compete with human food.

[0005] As a biodegradable resin using non-edible biomass raw materials, cellulose acetate has long been known. Cellulose acetate is a semi-synthetic polymer obtained by esterifying cellulose, which is a natural polymer, with acetic acid. Cellulose acetate, which is prepared from cellulose, a biomass that exists in large quantities in nature, is a so-called carbon-neutral material. Even if it is burned, it does not increase carbon dioxide on the earth, and it has a small environmental impact in production and disposal.

[0006] Since cellulose acetate itself does not have thermoplasticity, it is necessary to add a plasticizer to plasticize it in order to be used as a resin. As plasticizers for cellulose acetate, mainly glycerin-based plasticizers such as highly compatible dioctyl phthalate (DOP) and triacetin are used.

Means for Solving the Problems

[0007] The present inventors have surprisingly found that by blending a biodegradable compound, which has conventionally been used as a plasticizer for cellulose acetate, in an amount exceeding 40 parts by weight and not exceeding 80 parts by weight with respect to 100 parts by weight of cellulose acetate, a biodegradable thermoplastic resin composition having high moldability into sheets, films or fibers can be prepared. The biodegradable compound has been conventionally known as a plasticizer for cellulose acetate, but the amount added is much larger than the amount added as a plasticizer. The amount of plasticizer added to 100 parts by weight of cellulose acetate is usually about 0.1 to several parts by weight, and at most 40 parts by weight or less. This is because it is said that the plasticizer elutes when it exceeds 40 parts by weight.

Effects of the Invention

[0008] According to the present invention, a biodegradable thermoplastic resin composition derived from natural products can be provided using only non-edible biomass raw materials.

Modes for Carrying Out the Invention

[0009] In a first aspect, the present invention provides a biodegradable thermoplastic resin composition in which a compound serving as a plasticizer is blended with a polymer material made from non-edible biomass. More specifically, the biodegradable thermoplastic resin composition according to the first aspect of the present invention contains, per 100 parts by weight of cellulose acetate, a rosin-based compound selected from rosin, rosin ester, and rosin glycerin ester; unsubstituted or substituted C 1~10 an ester-based compound of an alcohol and acetic acid, lactic acid, phthalic acid, citric acid, or phosphoric acid; a glycerin-based compound selected from triacetin, diacetin, glycerin, polyglycerin, glycerin fatty acid ester, and polyglycerin fatty acid ester; a polyester-based compound; and a sugar alcohol-based compound selected from sorbitol, sucrose fatty acid ester, and sorbitan fatty acid ester, wherein the biodegradable compound is blended in an amount exceeding 40 parts by weight and not exceeding 80 parts by weight, preferably exceeding 50 parts by weight and not exceeding 80 parts by weight, for example, in an amount of 55 parts by weight or more or 60 parts by weight or more and not exceeding 80 parts by weight. When the addition amount of the biodegradable compound exceeds 40 parts by weight per 100 parts by weight of cellulose acetate, the thermoplasticity of the biodegradable compound starts to be exhibited, and when it is 80 parts by weight or less, the biodegradable compound does not elute from the surface of the biodegradable resin composition.

[0010] In the first aspect of the present invention, the biodegradable compound is preferably blended in an amount of 55 parts by weight or more and not exceeding 80 parts by weight per 100 parts by weight of the cellulose acetate.

[0011] In the first aspect of the present invention, the biodegradable compound is an ester-based compound of unsubstituted or substituted C 1~10 alcohol and acetic acid, lactic acid, phthalic acid, citric acid, or phosphoric acid.

[0012] In a second aspect, the present invention provides a method for manufacturing a molded article by molding the biodegradable thermoplastic resin composition obtained in the first aspect. As the method for manufacturing a molded article, a molding method selected from the group consisting of film molding, sheet molding, thermoforming, blow molding, injection molding, vacuum molding, melt spinning method, wet spinning method, and dry spinning method can be employed. By molding using any of the above molding methods, various molded articles such as films, sheets, and fibers can be obtained from the biodegradable thermoplastic resin composition obtained in the first aspect of the present invention.

[0013] In a second aspect of the present invention, when molding films, sheets, and fibers, the resin is melted at a temperature of 180 to 220 °C, preferably 180 to 200 °C.

[0014] Furthermore, in a third aspect, the present invention provides various molded articles such as films, sheets, and fibers, which are made of the biodegradable thermoplastic resin composition obtained in the first aspect of the present invention. Furthermore, woven fabrics and non-woven fabrics can also be obtained using fibers.

[0015] In a fourth aspect, the present invention provides a method for manufacturing a three-dimensional molded article by molding the biodegradable thermoplastic resin composition obtained in the first aspect. As the method for manufacturing a three-dimensional molded article, a material extrusion deposition method can be employed. By molding using the above molding method, various molded articles having a complex internal structure can be obtained from the biodegradable thermoplastic resin composition obtained in the first aspect of the present invention.

[0016] In a fourth aspect of the present invention, when molding a three-dimensional molded article, the resin is melted at a temperature of 190 to 250 °C, preferably 210 to 250 °C, more preferably 210 to 230 °C.

[0017] Furthermore, in a fifth aspect, the present invention provides various three-dimensional molded articles having a complex internal structure, which are made of the biodegradable thermoplastic resin composition obtained in the first aspect of the present invention.

Examples

[0018] A. Preparation of Cellulosic Thermoplastic Resin [Preparation Example 1] 4 kg of triethyl citrate was added to 10 kg of cellulose acetate, and the mixture was kneaded by a twin-screw extruder to prepare Cellulosic Thermoplastic Resin Composition 1 and produce Thermoplastic Resin Pellet 1.

[0019] [Preparation Example 2] 5 kg of triethyl citrate was added to 10 kg of cellulose acetate, and the mixture was kneaded by a twin-screw extruder to prepare Cellulosic Thermoplastic Resin Composition 2 and produce Thermoplastic Resin Pellet 2.

[0020] [Preparation Example 3] 5.5 kg of triethyl citrate was added to 10 kg of cellulose acetate, and the mixture was kneaded by a twin-screw extruder to prepare Cellulosic Thermoplastic Resin Composition 3 and produce Thermoplastic Resin Pellet 3.

[0021] [Preparation Example 4] 6 kg of triethyl citrate was added to 10 kg of cellulose acetate, and the mixture was kneaded by a twin-screw extruder to prepare Cellulosic Thermoplastic Resin Composition 4 and produce Thermoplastic Resin Pellet 4.

[0022] [Preparation Example 5] 7 kg of triethyl citrate was added to 10 kg of cellulose acetate, and the mixture was kneaded by a twin-screw extruder to prepare Cellulosic Thermoplastic Resin Composition 5 and produce Thermoplastic Resin Pellet 5.

[0023] [Preparation Example 6] 7.5 kg of triethyl citrate was added to 10 kg of cellulose acetate, and the mixture was kneaded by a twin-screw extruder to prepare Cellulosic Thermoplastic Resin Composition 6 and produce Thermoplastic Resin Pellet 6.

[0024] [Preparation Example 7] 10 Kg of cellulose acetate and 8 Kg of triethyl citrate were added and kneaded by a twin-screw extruder to prepare a cellulose-based thermoplastic resin composition 7, and thermoplastic resin pellets 7 were produced.

[0025] [Preparation Example 8] 10 Kg of cellulose acetate and 6 Kg of glycerin were added and kneaded by a twin-screw extruder to prepare a cellulose-based thermoplastic resin composition 8, but thermoplastic resin pellets could not be stably produced from this resin composition. That is, at room temperature, the shape of the pellets could not be maintained.

[0026] [Preparation Example 9] 10 Kg of cellulose acetate and 6 Kg of ethyl acetate were added and kneaded by a twin-screw extruder to prepare a cellulose-based thermoplastic resin composition 9, but thermoplastic resin pellets could not be stably produced from this resin composition. That is, at room temperature, the shape of the pellets could not be maintained.

[0027] [Preparation Example 10] 10 Kg of cellulose acetate and 6 Kg of butyl lactate were added and kneaded by a twin-screw extruder to prepare a cellulose-based thermoplastic resin composition 10, but thermoplastic resin pellets could not be stably produced from this resin composition. That is, at room temperature, the shape of the pellets could not be maintained.

[0028] [Preparation Example 11] 10 Kg of cellulose acetate and 6 Kg of dioctyl phthalate were added and kneaded by a twin-screw extruder to prepare a cellulose-based thermoplastic resin composition 11, but thermoplastic resin pellets could not be stably produced from this resin composition. That is, at room temperature, the shape of the pellets could not be maintained.

[0029] [Preparation Example 12] A cellulose acetate-based thermoplastic resin composition 12 was prepared by kneading 10 kg of cellulose acetate with 6 kg of tributyl citrate using a twin-screw extruder. However, thermoplastic resin pellets could not be stably produced from this resin composition. That is, at room temperature, the shape of the pellets could not be maintained.

[0030] [Preparation Example 13] A cellulose acetate-based thermoplastic resin composition 13 was prepared by kneading 10 kg of cellulose acetate with 6 kg of trioctyl phosphate using a twin-screw extruder. However, thermoplastic resin pellets could not be stably produced from this resin composition. That is, at room temperature, the shape of the pellets could not be maintained.

[0031] B. Manufacture of Molded Articles [Molding Examples 1 - 2] By the T-die method, 1 kg of thermoplastic resin pellets 1 or 2 was melted at 180°C, and the melted resin was extrusion-molded to obtain sheets 1 and 2 with a thickness of 0.2 mm. The melt flow rate of these thermoplastic resins was 8 - 9 g / 10 min at 200°C, and there was no problem with the fluidity during extrusion molding. All of the obtained sheets had low transparency, streaks, and a rough and unappealing surface.

[0032] [Molding Example 3] By the T-die method, 1 kg of thermoplastic resin pellets 3 was melted at 180°C, and the melted resin was extrusion-molded to obtain a sheet 3 with a thickness of 0.2 mm. The melt flow rate of this thermoplastic resin was 9 - 10 g / 10 min at 200°C, and there was no problem with the fluidity during extrusion molding. The obtained sheet had high transparency, a clean surface, flexibility, and sufficient strength.

[0033] [Molding Examples 4 - 6] By the T-die method, 1 kg of thermoplastic resin pellets 4, 5, or 6 were melted at 180 °C, and the melted resin was extrusion-molded to obtain sheets 4, 5, and 6 with a thickness of 0.2 mm. The melt flow rate of these thermoplastic resins was 10 - 12 g / 10 min at 200 °C, and there was no problem with the fluidity during extrusion molding. All of the obtained sheets had high transparency, very clean surfaces, flexibility, and sufficient strength.

[0034] [Molding Example 7] By the T-die method, 1 kg of thermoplastic resin pellets 7 were melted at 180 °C, and the melted resin was extrusion-molded to obtain a sheet 7 with a thickness of 0.2 mm. The melt flow rate of this thermoplastic resin was 12 - 14 g / 10 min at 200 °C, and there was no problem with the fluidity during extrusion molding. The obtained sheet had high transparency, a clean surface, flexibility, and sufficient strength.

[0035] [Molding Example 8] By the melt spinning method using a melt spinning apparatus, 1 kg of thermoplastic resin pellets 5 were melted at 200 °C, and the melted resin was extruded and spun into the air from a nozzle to obtain fibers 1 with a diameter of about 0.8 - 1.2 mm. The melt flow rate of this thermoplastic resin was 10 - 12 g / 10 min at 200 °C, and there was no problem with the fluidity during extrusion spinning.

[0036] [Molding Example 9] By the material extrusion deposition method using a 3D printer, 1 kg of thermoplastic resin pellets 4 were melted, and the melted resin was extruded layer by layer and stacked to obtain a three-dimensional structure 1 in the shape of a cylinder with a radius of 5 cm and a height of 5 cm. When the temperature was set at 180 - 200 °C, the adhesion between layers of the obtained laminate was insufficient, but when the temperature was raised to 210 - 250 °C, no delamination occurred between layers, and a good structure could be obtained. In this molding example, 3D printing was performed at 210 °C. The melt flow rate of this thermoplastic resin was 10 - 12 g / 10 min at 200 °C, and there was no problem with the fluidity during extrusion deposition.

Industrial Applicability

[0037] The biodegradable thermoplastic resin composition of the present invention is particularly useful for manufacturing molded articles such as films, sheets, and fibers that require stretching during molding.

Claims

1. A biodegradable thermoplastic resin composition comprising 55 parts by weight or more and 80 parts by weight or less of a biodegradable compound, triethyl citrate, per 100 parts by weight of cellulose acetate.

2. A method for producing a molded article, comprising molding the biodegradable thermoplastic resin composition according to claim 1 into a film, sheet, or fiber by a molding method selected from the group consisting of film molding, sheet molding, thermoforming, blow molding, injection molding vacuum molding, melt spinning, wet spinning, and dry spinning.

3. The method according to claim 2, comprising melting the biodegradable thermoplastic resin composition according to claim 1 at a temperature of 180 to 200°C.

4. A molded article selected from a film, a sheet, and a fiber, comprising the biodegradable thermoplastic resin composition according to claim 1.