RU2796759C1 - Modified thermoplastic organic material and method of its production - Google Patents

Abstract

FIELD: production of organic materials.

SUBSTANCE: group of inventions relates to a modified thermoplastic organic material including a polysaccharide and a plasticizer, characterized by the fact that a polysaccharide selected from vegetable starch, a water-alcohol plasticizer A is used to ensure swelling of the organic phase, and a plasticizer B is used to provide structural and accelerated plasticization, as well as functional agent, with the following ratio of components per 1 kg of material, wt.%: polysaccharide — 39–90, plasticizer A — 5–60, plasticizer B — 5–60, functional agent — 0.001–10, and also refers to a method of producing a modified thermoplastic organic material, including the interaction of the polysaccharide with plasticizers, the introduction of functional agents and further extrusion of the mixture into a modified organic material using a screw extruder, characterized by the fact that the mixing of the polysaccharide with plasticizers is carried out in a mixer with paddle rolls for 5–15 minutes at a temperature of 60–100°C, followed by drying in a vacuum oven at a temperature of 60–100°C for 1–10 hours with further cooling at a room temperature or using a refrigerator until 15–35°C grinding with a disk or other type of mill to fractions of a size sufficient for dosing into an extruder, with the following ratio of components per 1 kg of material, wt.%: polysaccharide — 39–90, plasticizer A — 5–60, plasticizer B — 5–60, functional agent — 0.001–10.

EFFECT: group of inventions provides for the creation of a biodegradable thermoplastic material for the production of a packaging film with a thickness of 15–30 microns.

6 cl, 1 ex

Description

The invention relates to a modified thermoplastic organic material, including a polysaccharide and a plasticizer, as well as to a method for producing this material.

Known composite material based on starch, which is used for extrusion of melts, and a method for its preparation (patent CN106366355 A, C08K 13/02, C08K 3/22, C08K 3/34, C08K 3/36, C08K 5/053, C08K 5/ 098, C08K 5/134, C08K 5/20, C08L 23/08, C08L 29/04, C08L 3/02, C08L 31/04, C08L 67/02, C08L 67/04, C08L 71/02, published 01.02 .2017). The invention relates to a composite material based on plasticized starch and to a method for its preparation, relating to the technical field of starch modification. A starch composite material suitable for melt extrusion is prepared from the following raw materials in parts by weight: 90-100 parts of starch, 5-30 parts of plasticizer, 0.1-25 parts of a melt flow improver, 0.1-20 parts of compatibilizer, 0 ,5-5 parts of aldehyde and 0-90 parts of biobased resin. The starch composite material applicable for melt extrusion has the advantages of low raw material cost, excellent plasticity, excellent processing fluidity, much higher strength, wide adaptability and application range, energy saving and environmental protection, and overcome the recrystallization and reversible reaction of starch.

Known biodegradable material and its use for plastic products (patent CN105968417 A, B29C 48/92, C08K 5/00, C08K 5/098, C08K 5/10, C08K 5/17, C08K 5/37, C08L 3/02, C08L 67/04, published on September 28, 2016). The invention discloses a method for producing a biodegradable material and its use in plastic products. The biodegradable material is prepared from the following raw materials in parts by weight: 25 to 35 parts of bean starch, 10 to 20 parts of soy starch, 6 to 8 parts of polylactic acid, 1 to 3 parts of triethanolamine, 2 to 4 parts of diethylene glycol, 0 ,6-0.8 parts of n-butyl alcohol, 2-4 parts of magnesium stearate, 1-3 parts of dodecahydroxystearic acid, 3-5 parts of oxidized castor oil and 6-8 parts of pentaerythritol ether and mercaptoethanol, where the mass ratio of pentaerythritol ester and mercaptoethanol is (5-7):1. The resulting biodegradable material is not only biodegradable, but also has excellent tensile strength and elongation at break. The technical effect is related to the weight ratio of pentaerythritol ether and mercaptoethanol taken as raw materials, and the effect is best when the weight ratio of pentaerythritol ether and mercaptoethanol is (5-7):1. The biodegradable material obtained in this way can be used for the manufacture of degradable plastic products, it is harmless to health and the environment.

Known high-strength fully degradable film and method for its manufacture (patent CN104892991 A, C08J 5/18, C08K 13/02, C08K 3/22, C08K 5/053, C08K 5/17, C08K 5/20, C08K 7/14, C08L 29/04, C08L 3/02, C08L 5/00, C08L 71/08, published 09/09/2015). The invention discloses a method for producing a high-strength fully degradable film, characterized in that it contains the following starting materials by weight: 40-60 parts of corn starch, 3-5 parts of zircon powder, 3-5 parts of titanium white, 20-30 parts of polyvinyl alcohol, 3- 5 parts konjac gum, 15-25 parts glycerin, 4-10 parts ethyl orthosilicate, 3-5 parts glass fiber, 1-2 parts alizarin oil, 2-4 parts polyethylene glycol (PEG), 1-2 parts oleic acid amide, 1-2 parts of oleic acid triethanolamine; and 1-2 parts of sodium caseinate. Thus, a high-strength fully degradable film is obtained, which has strong corrosion resistance, good waterproof performance, good environmental performance and environmental friendliness.

The disadvantages of the above analogs include the multicomponent nature of the compositions, the laboriousness of the preparation of the initial components (special conditions for drying and grinding), and the multistage, difficultly scalable synthesis.

A known method for producing a degradable thermoplastic starch material and a product from it (patent CN106543483 A, B29B 9/06, B29C 48/92, C08L 1/02, C08L 3/00, publ. 03/29/2017), selected as a prototype. The invention discloses a method for producing a degradable thermoplastic starch material, in which the reactants are raw starch, an initiator, a plasticizer and natural cellulose. The main stages of the synthesis: the placement of raw starch in a reactor with a stirrer, the addition of an initiator. Then natural cellulose, plasticizer and modified starch are mixed in a high-speed mixer, which ensures uniform mixing, then the mixture is transferred to a single screw extruder, where plasticization and granulation are carried out. According to the present invention, the preparation method is simple and non-polluting, the resulting thermoplastic starch can be used alone or as an additive to biodegradable plastic.

The disadvantage of the prototype is the fragility and lack of surface smoothness in the manufacture of films.

The objective of the invention is to create a biodegradable thermoplastic material for the production of a packaging film with a thickness of 15-30 microns.

The technical solution of the present invention is a modified thermoplastic organic material, including a polysaccharide and a plasticizer.

The modified thermoplastic organic material includes a polysaccharide and a plasticizer. One or more polysaccharides selected from the group of vegetable starch and/or flour of vegetable origin and/or flour of vegetable origin are used, water-alcohol plasticizer A to ensure swelling of the organic phase and plasticizer B to provide structural and accelerated plasticization, as well as a functional agent, with the following ratio of components per 1 kg of material, mass h:

polysaccharide - 39-90

plasticizer A - 5-60

plasticizer B - 5-60

functional agent - 0.001-10.

Amino compounds, sorbitols, sorbitol esters, synthetic and natural surfactants are used as plasticizer B.

One or more metal compounds selected from the group of sulfates, nitrates, stearates, octoates and carboxylates are used as a functional agent.

The method for obtaining a modified thermoplastic organic material includes the interaction of a polysaccharide with plasticizers, the introduction of functional agents and further extrusion of the mixture into a modified organic material using a screw extruder. Mixing of polysaccharide with plasticizers is carried out in a mixer with paddle rolls for 5-15 minutes at a temperature of 60-100°C, followed by drying in a vacuum oven or oven at a temperature of 60-100°C for 1-10 hours with further cooling at room temperature or with the help of a cold chamber up to 15-35°C, grinding with a disk or other type of mill to fractions of a size sufficient for dosing into an extruder, with the following ratio of components per 1 kg of material, wt.h:

polysaccharide - 39-90

plasticizer A - 5-60

plasticizer B - 5-60

functional agent - 0.001-10.

After obtaining a mixture based on a polysaccharide and a plasticizer, functional agents are added by mixing mechanically in a paddle, planetary or turbo mixer until uniform mixing.

The mixture is extruded continuously into a strand using a twin-screw extruder, with air-cooled strand cooling and granulation using a granulating machine at an extrusion temperature in the working zones of the extruder 80-110 ° C, a screw speed of 380-420 rpm with an extruder barrel length of 35 - 60L/D.

Available cheap organic materials such as starch have two drawbacks - due to their molecular nature, they are not thermoplastic and are formed in the form of large grains-globules. It is necessary to reduce the size of the globules and transfer the material to a thermoplastic state. This is achieved by the introduction of plasticizers, including chemically attached ones, and by the action of shear loads with temperature. In the present invention, it is proposed to use two types of plasticizers conventionally divided into primary and secondary. Primary plasticizers are designed to provide swelling of the organic phase. Secondary plasticizers are structural plasticizers and are designed to speed up the plasticization process.

The organic phase according to one of the embodiments of the invention is a polysaccharide, one or more selected from potato, corn, rice, pea, wheat, tapioca starch, other natural starches, chemically and/or physically modified starch, extruded starch; is pea flour; represents flour one or more selected from rice, buckwheat, corn, pea or other cereals; is a mixture of organic fillers. Preferably, the organic filler is corn starch and/or rice flour, ground and/or sieved with a fraction size of 1-40 µm. Preferably the organic filler contains no more than 20% water.

The primary plasticizer A of the organic phase according to one of the embodiments of the invention is one or more of the following substances: water, dihydric and trihydric alcohols, for example, glycerin, and other polyhydric alcohols, glycols and polyglycols, for example, ethylene glycol, propylene glycol.

Secondary plasticizer B of the organic phase according to one of the embodiments of the invention is one or more of the following substances: amino compounds, for example, triethanolamine, diethanolamine, urea; sorbitol, sorbitan esters, for example, sorbitan oleate, synthetic and natural surfactants. Most preferably, the organic phase plasticizer is triethanolamine.

The functional agent according to one of the embodiments of the invention is one or more of the metal compounds, for example, sulfates, nitrates, stearates, octoates and carboxylates, providing an organic phase dispersing action, an organic phase plasticizing action, additional acceleration of material degradation in compositions with other polymeric materials in the natural environment. Preferably, the functional agent is copper salts and/or zinc salts and/or iron salts. Most preferably, the functional agent is copper sulfate and/or zinc nitrate and/or iron stearate.

An example of the invention is shown below.

The method for obtaining a modified organic material consists in the following steps, conditions for the preparation and processing of components:

Stage 1. Weighing the following components in the ratios: organic filler - 40-95 mass parts, plasticizer of organic filler - 5-60 mass parts, functional agent - 0.1-5 mass parts.

Stage 2. Mixing of the organic phase with plasticizers.

Mixing of the components is carried out in a paddle roll mixer, for example, a Z-type mixer, a Banbury mixer, an intermix mixer. The organic phase is introduced into the mixer first. The plasticizer is then dosed, ensuring uniform gradual mixing. The resulting mixtures are dried at a temperature of 60 - 100°C. The duration of drying time is 1 - 10 hours. The equipment used for drying can be a vacuum oven, a drying cabinet. The mixture after drying is cooled at room temperature or using a refrigerator to 15-35°C. Next, the mixture is ground using a disk or other type of mill to fractions of no more than 1 mm.

Stage 3. Mixing the mixture based on the organic phase and the plasticizer with functional agents.

The mixtures are combined mechanically in a paddle type mixer, planetary mixer or in a turbo mixer until uniform mixing.

Step 4: Extruding the mixture of components into a modified thermoplastic organic material.

The mixture is extruded into a strand and then into pellets. Mixing is done with a twin screw extruder. The granulation is done by a machine granulating a strand of modified organic material material. The extrusion temperature in the working zones of the extruder is 80-110°C. The rotation speed of the screw is 380-420 rpm with the length of the extruder barrel 35 - 60 L/D. The strand is air-cooled and granulated. The stage is carried out continuously.

The modified material meets the requirements for the processing of polymeric materials on existing standard equipment. There is no need to create new equipment for its production of material and its processing into finished products. The method of obtaining the claimed material on traditional equipment is simple and has no restrictions on the scaling of the process performance.

Claims (14)

1. A modified thermoplastic organic material comprising a polysaccharide and a plasticizer, characterized in that it uses a polysaccharide selected from vegetable starch, a water-alcohol plasticizer A to ensure swelling of the organic phase and a plasticizer B to provide structural and accelerated plasticization, as well as a functional agent, with the following ratio of components per 1 kg of material, wt.h: polysaccharide - 39-90 plasticizer A - 5-60 plasticizer B - 5-60 functional agent - 0.001-10. 2. Modified thermoplastic organic material according to claim 1, characterized in that amino compounds, sorbitols, sorbitol esters, synthetic and natural surfactants are used as plasticizer B. 3. Modified thermoplastic organic material according to claim 1, characterized in that one or more metal compounds selected from the group of sulfates, nitrates, stearates, octoates and carboxylates are used as a functional agent. 4. A method for producing a modified thermoplastic organic material according to claim 1, including the interaction of a polysaccharide with plasticizers, the introduction of functional agents and the further extrusion of the mixture into a modified organic material using a screw extruder, characterized in that the mixing of the polysaccharide with plasticizers is carried out in a mixer with paddle rolls 5 -15 minutes at a temperature of 60-100°C, followed by drying in a vacuum oven or oven at a temperature of 60-100°C for 1-10 hours, followed by cooling at room temperature or using a refrigerator to 15-35°C , grinding with a disk or other type of mill to fractions of a size sufficient for dosing into an extruder, with the following ratio of components per 1 kg of material, wt.h: polysaccharide - 39-90 plasticizer A - 5-60 plasticizer B - 5-60 functional agent - 0.001-10. 5. A method for producing a modified thermoplastic organic material according to claim 4, characterized in that after obtaining a mixture based on a polysaccharide and a plasticizer, functional agents are added by mixing mechanically in a paddle type mixer, planetary mixer or in a turbo mixer until uniform mixing. 6. A method for producing a modified thermoplastic organic material according to claim 4, characterized in that the extrusion of the mixture is carried out continuously into a strand using a twin screw extruder, with air cooling of the strand and granulation using a granulating machine at an extrusion temperature in the working zones of the extruder 80-110 ° C, screw speed 380-420rpm with barrel length 35-60L/D.