WO2018199494A1 - Multi-degradable polyolefin-based resin composition and method for preparing same - Google Patents

Abstract

The present invention relates to a multi-degradable polyolefin-based resin, wherein, without using high-cost biodegradable raw materials such as starches or aliphatic polyester-based materials and the like, a small amount of additives, such as a photolytic agent, an oxidative degradation agent, or a microorganism degradation agent and the like, are added to the polyolefin-based resins and a dehumidifying agent is used and by mixing, unheated, at room temperature without using a high-speed stirrer maintained at 80ºC, a homogenous mixture is obtained and then a melt extruder can be continuously used to provide a homogenous pellet-shaped multi-degradable master batch and a compound composition.

Description

Complex degradable polyolefin resin composition and preparation method thereof

The present invention relates to a polydegradable polyolefin resin composition and a method for manufacturing the same, and more particularly, to a method for preparing a biodegradable homogeneous pellet by adding a small amount of a dehumidifying agent such as a photodegrading agent, an oxidizing agent and the like to a polyolefin resin. will be.

The biodegradable resins thus far developed are polylactic acid (PLA) resins synthesized from starch, corn, milk powder, etc., polycaprolactone (PCL) resins synthesized chemically from epsilon caprolactone monomers, and diols ( Aliphatic polyester-based resins of dihydric alcohol) -dibasic acid (dicarboxylic acid) series, and polyhydroxybutylate (PHB) produced by in vivo synthesis of other microorganisms. Such biodegradable resins can be finally biodegraded into water and carbon dioxide due to the action of enzymes produced by microorganisms.

Polylactic acid-based resin is less than half the price of aliphatic polyester and has good transparency and high hardness, so it is suitable for use as a packaging container, but its elongation rate is low and breakage due to impact occurs easily and blow molding for film production There is a problem in that a hole is formed in the thin portion in the process. In addition, there are many limitations in producing a film by blow molding because of low thermal deformation temperature and poor bubble stability due to a slow cooling rate.

Polycaprolactone-based resins have a disadvantage of low workability due to their low melting point, and aliphatic polyester-based resins have considerable advantages in terms of physical properties because they are more flexible, elongate, and have a higher heat-resistant operating temperature than PLA. Although the price is very expensive, the practical use is being delayed. Photodegradable additives, biodegradable resins, thermal decomposition agents, complex decomposition additives and the like are used for plastic decomposition, and among these, interest is increasing about complex decomposition decomposed by one or more mechanisms.

Republic of Korea Patent No. 10-1013453 prepared a composite degradable material using starch, it is impossible to use the properties of the starch directly as a plastic product, it is mainly necessary to blend or modify with other materials. However, in the process of using a starch plasticizer when reforming starch, an expensive reactive extrusion (REX) is required.

In order to produce complex decomposed plastics containing starch, a general extruder for starch must be used instead of a general general purpose extruder. As a prior art regarding plastic composite decomposition, Korean Patent Registration No. 062323 discloses a composite degradable thermoplastic polymer composition. However, the amount required for the entire composition in order to cause a sufficient decomposition effect of the plastic products has a problem of increasing the manufacturing cost, and also because they are difficult to be molded by using a mass production molding machine used in the existing, such as the introduction of new equipment There is also a limit in producing a biodegradable film, etc., with the enormous additional costs incurred as a main component thereof.

Korean Patent Application No. 1996-64953 discloses a bio / photodegradable mulching film composition for agricultural use, but the composition has low decomposition rate and can be regarded as decay rather than degradable, and also has a polymer material such as polycaflolactone or polylactic acid. It is difficult to industrialize due to high manufacturing costs due to its mainly use.

US Patent No. 3941759 discloses a plastic composition which can be photolyzed by ultraviolet rays by adding a photosensitizer, which is an organic compound, and US Patent No. 3992487 is a mixture of a thermoplastic polymer and a polymer containing metal ions. It provides a plastic composition that can be photolyzed by. However, the plastic compositions described in these patents have limitations such as a long decomposition period and embedding in soil, which do not decompose in the absence of light.

Looking at other prior art, it is prepared using a small amount of 24 raw materials, for example, the component consists of 55% calcium carbonate, 24% synthetic resin, 10% by weight polyvinyl alcohol and the remaining 10% by weight It consists of 20 kinds of additives. Therefore, since the addition amount of each additive is mixed at a temperature of 80 ° C. while being added in a small amount of 1% by weight or less, reproducibility is not secured when materials having low decomposition temperatures are volatilized or scattered.

In addition, in the high speed stirring step of 80 ° C., only one raw material of polyvinyl alcohol is mixed first, and then a part of all the raw materials is sequentially added and mixed, and calcium carbonate and some raw materials are separately mixed at room temperature, and then the low speed stirring step is performed. In the above method of mixing all the raw materials, which is divided into several stages to be mixed, there may be a problem to apply to a continuous production process.

In fact, as a result of application in the production plant, calcium carbonate dispersibility is poor, polyvinyl alcohol is carbonized and adhered to the film surface, or it is incompatible with polyolefin resins, so bubbles are formed when forming into a film, or surface texture is very rough. This phenomenon occurred, and such a problem occurred that the fundamental reproducibility is not secured.

The necessity to identify the complex reaction process between the 24 raw materials in the mixing of each raw material was raised, and also the distribution and dispersion of filler particles in the mixing process of the calcium carbonate filler using 55% by weight and these additives It is an important technical matter to train efficiently to make it happen uniformly. Even if calcium carbonate dried in the pretreatment stage is very hygroscopic, it is non-uniform by reacting with the mixing reaction between 24 kinds of raw materials and water and gas which may occur in melt extrusion process. One mixed composition has the risk of being prepared.

Therefore, without the use of starch materials, it is possible to use the production equipment commonly used in the art, and the products with good complex degradability even using low-cost raw materials, can activate the current biodegradable market.

[Preceding technical literature]

[Patent Documents]

Patent Document 1. Republic of Korea Patent No. 10-0602385

Patent Document 2. Republic of Korea Patent No. 10-1013453

An object of the present invention is to use a small amount of additives such as photodegradants, oxidative decomposers and microbial decomposers to polyolefin resins without using expensive bio-biodegradable raw materials such as starch or aliphatic polyesters. By using a non-heated mixture at room temperature without using a high speed stirrer to maintain a homogeneous mixture by using a continuous melt extruder to provide a multi-disassembled master batch and compound composition in the form of a homogeneous pellet will be.

Various molded products, such as films, sheets, bottles, injection molded articles, etc., which are decomposed by extrusion molding, inflation molding, injection molding, blow molding, etc. using the provided composition. It is to provide a method for producing.

In order to achieve the object of the present invention, the present invention is a polyolefin resin, grafted polyolefin resin, powdered calcium carbonate, pellet calcium carbonate, dehumidifying agent, photodegrading agent, initiator, polyvinyl alcohol, biodegrading agent or biodegrading agent, Provided is a polydegradable polyolefin resin composition comprising a polyvinyl alcohol plasticizer, an anionic surfactant, a lubricant, and borax.

Preferably, the polyolefin resin is a polydegradable polyolefin resin composition, characterized in that at least one mixture selected from the group consisting of low density polyethylene, linear low density polyethylene, polypropylene.

Preferably the grafted polyolefin resin is a composite characterized in that at least one mixture selected from the group consisting of grafted low density polyethylene, grafted high density polyethylene, grafted linear low density polyethylene, grafted polypropylene It is a decomposable polyolefin resin composition.

Preferably, the dehumidifying agent is characterized in that at least one mixture selected from the group consisting of zeolite, bentonite, diatomaceous earth, silica gel, activated carbon, superabsorbent resin.

According to an embodiment of the present invention provides a compound compound decomposable polyolefin resin composition further comprising 200 to 600 parts by weight of a high density polyethylene resin with respect to 100 parts by weight of the polyolefin resin composition.

According to another embodiment of the present invention, the multi-decomposable polyolefin-based resin composition molded article is molded by at least one method of extrusion molding, inflation molding, injection molding and blow molding using the compound. To provide.

In order to achieve the object of the present invention (1) adding polyvinyl alcohol and polyvinyl alcohol plasticizer to the stirrer and then mixing to plasticize the polyvinyl alcohol; (2) polyolefin resin, grafted polyolefin resin, powdered calcium carbonate, pellet type calcium carbonate, dehumidifying agent, photodegradant, initiator, biodegradable or biodegradable agent, anionic surfactant, lubricant in the plasticized polyvinyl alcohol Adding borax sequentially; And (3) injecting the mixture into an extruder, followed by melting and kneading, and cooling the mixture, thereby providing a method for producing a masterbatch having a polydegradable polyolefin-based resin composition.

According to the present invention as described above, without the use of expensive biodegradable raw materials such as starch or polyester enables biodegradation by simple addition and easy extrusion. As a result, the manufacturing cost of the composite degradable plastics can be reduced, thereby activating the biodegradable market and contributing to many environmental problems, thereby expanding the market demand. In the case of the biodegradable agent of the present invention, it can be produced at a low price of about 40% compared to the biodegradable agent using general polyethylene raw materials and starch.

More specifically, extrusion can be enabled by using a dehumidifying agent, pelleted calcium carbonate, graft low density polyethylene and plasticized polyvinyl alcohol instead of starch.

1 is a (a) cumulative carbon dioxide generation curve, (b) biodegradation curve of the standard (cellulose).

Figure 2 is a (a) cumulative carbon dioxide generation curve, (b) biodegradation curve of the biodegradable envelope.

Hereinafter, the present invention will be described in detail.

The complex decomposition process of the composite degradable plastic of the present invention goes through the following steps.

(1) A polyolefin resin composition composed of a long chain carbon-carbon bond.

(2) When the PE wax, sorbitol, and sodium alginate components contained in the composition are decomposed after self-decomposition by the enzymatic reaction process itself, the polyolefin-based resin polymer is exposed to surface area while decreasing weight due to the decomposed biodegradable mass.

(3) Stearic acid components react with the carbon-carbon bonds of the exposed polyolefinic polymer component, some of which are transferred to calcium stearate and some of which partially decompose to form peroxides or hydroperoxides.

(4) The iron stearate and magnesium stearate contained in the composition serve as an initiator to help initiate the reaction of the stearic acid component, and then the iron stearate, magnesium stearate, and calcium stearate serve as an oxidation reaction accelerator, resulting in a peroxide. The redox reaction is repeated to generate free radicals with high reactivity, and auto oxidizes, thereby starting radical reaction using light or heat as reaction energy.

(5) Acetyl acetonite, dimethyldithiocarbamic acid, and iron chloride components also react with light to generate free radicals, acting as photocatalytic accelerators, to initiate radical reactions.

(6) When the radical reaction starts, oxidative decomposition is continuously performed even in the absence of light, thereby cutting the carbon chain and lowering the molecular weight of the thermoplastic polymer.

(7) Low molecular weight polyolefin resin The polymer is present in the form of carboxylic acid, ketones, aldehydes, carboxylic acids and the like which are easily decomposed.

(8) Oxidation reaction aids such as calcium carbonate and polyvinyl alcohol, which are contained in the composition, absorb moisture under external conditions and provide a humid environment in which microorganisms can be actively active, thereby converting them into water, carbon dioxide and biomass. Has been disassembled.

Therefore, in order to produce a composite degradable plastic molded article capable of exhibiting oxidation, automatic oxidation, photodegradation, and microbial degradation, biodegradable raw materials, oxidative raw materials, initiators (oxidation reaction accelerators), photodegradants, oxidation reaction promoters, etc. It can be seen that the raw materials should be included.

Thus, all the starches selected from the group consisting of starch, modified starch and starch derivatives, complex biodegradable biodegradable without using expensive bio-biodegradable raw materials such as PLA, PCL and aliphatic polyester based by chemical synthesis It was confirmed that biodegradation is possible by using a small amount of additives such as photodegradants, oxidative decomposers and microbial decomposers in polyolefins to manufacture plastics. It was confirmed that homogeneous pellet production was possible by continuously using a melt extruder after obtaining a homogeneous mixture by mixing the stirrer non-heating at room temperature without using.

In order to achieve the object of the present invention, the present invention is a polyolefin resin, grafted polyolefin resin, powdered calcium carbonate, pellet calcium carbonate, dehumidifying agent, photodegrading agent, initiator, polyvinyl alcohol, biodegrading agent or biodegrading agent, It provides a polyvinyl alcohol plasticizer, an anionic surfactant, a lubricant, borax, characterized in that it comprises a polydegradable polyolefin resin composition.

Preferably, the present invention is 10.0 to 17.2% by weight of polyolefin resin, 3.7 to 6.1% by weight of grafted polyolefin resin, 22.4 to 41.6% by weight of powdered calcium carbonate, 14 to 26% by weight of pellet type calcium carbonate, 1.4 to dehumidifying agent 2.6% by weight, photodegradant 0.96-1.78%, initiator 3.52-6.54%, polyvinyl alcohol 6.32-11.59%, biodegradable or biodegradable 3.93-7.30%, polyvinyl alcohol plasticizer 1.22-2.16% It provides a polydegradable polyolefin resin composition comprising 0.21 to 0.39% by weight of anionic surfactant, 2.1 to 3.9% by weight of lubricant, and 0.07 to 0.13% by weight of borax.

More preferably, 10.0 to 17.2 wt% of polyolefin resin, 3.7 to 6.1 wt% of grafted polyolefin resin, 22.4 to 41.6 wt% of powdered calcium carbonate, 14 to 26 wt% of pelleted calcium carbonate, 1.4 to 2.6 wt% of zeolite %, 6.32 to 11.59 weight% polyvinyl alcohol, 0.07 to 0.13 weight% borax, 0.37 to 0.6 weight% pigment, 4.3 to 7.9 weight% PE wax, 0.015 to 0.025 weight% acetylacetonate, dimethyldithiocarbamic acid (dimethyldithiocarbamic acid) 0.70 to 1.17 wt%, iron chloride 0.30 to 0.52 wt%, ferric stearate 2.10 to 3.54 wt%, magnesium stearate 1.43 to 2.38 wt%, stearic acid 0.45 to 0.75 wt% %, Glycerin 2.1 to 3.5% by weight, glycerol (glyceryl monostearate) 0.3 to 0.5% by weight, polyethylene glycol 0.3 to 0.5% by weight, sorbitol 0.079 to 0.128% by weight, car Carboxymethyl cellulose (CMC-Na) 0.073 to 0.128 wt%, sodium lauryl sulfate 0.146 to 0.256 wt%, lauryl benzene sulfonic acid sodium 0.073 to 0.128 wt%, benzoyl peroxide (BPO) 0.009 To 0.017% by weight, sodium alginate (sodium alginate) 0.042 to 0.078% by weight, methyl salicylic acid (methyl salicylic acid) provides a multi-degradable polyolefin-based resin composition comprising a.

The raw materials used in the mixing process and the extrusion molding process for producing the molded article of the present invention are summarized below in the compositions of the present invention. Each raw material is not limited to the following uses or ranges.

The polyolefin resin may be one or a mixture of two or more selected from the group consisting of low density polyethylene, linear low density polyethylene, and polypropylene. Preferably from 10 to 17.2% by weight, but most preferably 14% by weight. The polyolefin resin is a first low density polyethylene having a melt index of 1.5 to 2.5 g / 10 min, preferably a melt index of 2.0 g / 10 min. The density has a density of 0.9 to 1 g / cc, preferably 0.910 to 0.925 g / cc, more preferably 0.921 g / cc. Polypropylene is approximately 0.9 to 0.91 g / cc.

The grafted polyolefin resin may be one or a mixture of two or more selected from the group consisting of grafted low density polyethylene, grafted high density polyethylene, grafted linear low density polyethylene, grafted polypropylene. Preferably from 3.7 to 6.1% by weight of grafted low density polyethylene can be used, more preferably from 5% by weight.

The grafted polyolefin resin is preferably low density polyethylene grafted with maleic anhydride, and has a melt index of 3.8 to 6.5 g / 10 min, preferably a melt index of 5.0 g / 10 min. This is because the melt index, density and material properties of each of the resin is difficult to homogeneous mixing, the addition of low-density polyethylene resin grafted with maleic anhydride allows for improved mixing and physical properties of the resin.

Films containing 6.1 wt% or more of low density polyethylene grafted with maleic anhydride are degraded due to a decrease in elongation, and when not added, film formation is not smooth. Maleic anhydride LDPE used in the present invention improves the compatibility of polyvinyl alcohol and polyolefin resins. In addition, the use of improving the compatibility between resins, for example, there is an effect of improving the compatibility with calcium carbonate as well as low density polyethylene and high density polyethylene and polypropylene resins.

The calcium carbonate filler used in the present invention is used for reducing the manufacturing cost of the composite decomposition plastic, increasing strength, promoting biodegradability due to the collapse of the calcium carbonate matrix during biodegradation. In consideration of cost reduction and dispersibility, in the present invention, 22.4 to 41.6 wt% of powdered calcium carbonate and 14 to 26 wt% of pelleted calcium carbonate were used. Preferably, 32 wt% of powdered calcium carbonate and 20 wt% of pelletized calcium carbonate were used.

The 20% by weight of the pellet type calcium carbonate (Pellet CaCO3) comprises 14% by weight of calcium carbonate relative to the total polyolefin-based resin composition, so the total amount of calcium carbonate added in the present invention means about 46% by weight. If the total amount of calcium carbonate used is less than about 30% by weight compared to the resin composition, the cost reduction effect is insignificant.If the amount of the calcium carbonate exceeds about 60% by weight, the resin content is insufficient due to the insufficient resin content and poor dispersibility. Treated calcium carbonate or dispersant should be used additionally.

The powdered calcium carbonate particle size used in the present invention is preferably 0.2 to 5 µm, more preferably 0.5 to 3 µm. When the particles are thicker than the above ranges, the particles are precipitated, which adversely affects physical properties such as tensile strength, and when the particles are too fine, may cause a cost increase, and the shearing force is increased during mixing, and thus dispersibility may be lowered due to cohesion of the particles.

The pellet-type calcium carbonate is produced in pellet form by separately mixing the weight ratio of calcium carbonate and low density polyethylene to 6 to 8: 2 to 4, preferably 7: 3. The low density polyethylene is separate from the low density polyethylene in the polydegradable polyolefin resin composition, and may be referred to as a second low density polyethylene. When the calcium carbonate is formulated only in powder form, the mixture is scattered during mixing or takes a lot of mixing time. Thus, as a result of using the calcium carbonate in the form of a pellet, a more homogeneous mixture could be prepared.

The present invention was able to replace expensive starch using dehumidifying agents, pelleted calcium carbonate, graft low density polyethylene and plasticized polyvinyl alcohol, and a high speed stirrer maintained at 80 ° C. to produce products containing starch conventionally. A homogeneous mixed composition was made possible by stirring a Henkel mixer or the like at room temperature without using. Examples of the dehumidifying agent include zeolite, bentonite, diatomaceous earth, silica gel, activated carbon, quicklime, and super absorbent polymer.

In order to prevent the problem that the dehumidifying agent reacts with moisture and gas in the mixing reaction process and melt extrusion process in which the calcium carbonate having strong hygroscopicity and 24 additives are mixed at one time, a nonuniform mixture composition can be produced. Used. Preferably, a zeolite is used that can utilize simple physical adsorption of fine and many pores formed during the reaction.

In the present invention, the zeolite was used by adding 1.4 to 2.6 wt%, preferably 2 wt%. Zeolites are capillary pores whose pore structure can be stored in the pores without draining water due to capillary action. It is also a chemically stable natural substance that does not react with other raw materials and is a powder or granular product with high specific surface area and uniform pores. The product has a very low secondary cohesion and shows high dispersibility in the mixture and can be used at high temperatures such as 700 ° C. with high thermal stability. As a result, about 25 kinds of raw materials can be mixed at room temperature without applying heat, and a uniform mixture composition can be obtained, as well as reproducibility problems due to decomposition temperature differences can be solved.

In the biodegradation process of the present invention, the polymer chain becomes a low molecular hydrophilic compound by photodegradants. Due to the hygroscopic action of hydrophilic polyvinyl alcohol, glycerin, carboxymethylcellulose and calcium carbonate fillers, the plastic composition can maintain a humid environment suitable for mold growth. Hydrophilic polymer materials react with water to dissolve and initially transfer to a wet gel state, but over time they become hard gels and thus cannot be optimized for mold. Thus, when zeolite is used, it can react with water to adsorb water in the millions of nano-sized capillary pores, thereby preserving it, not discharging it, and thus maintaining a humid environment.

The photodegradants include acetylacetonate, dimethyldithiocarbamic acid and iron chloride. Acetylacetonate reacts with light to generate free radicals to act as a photolysis accelerator, and in the present invention, ferric stearate or magnesium stearate using 0.02% by weight of cobalt triAcetylAcetonate When combined with a transition metal such as), it exhibited a ligand function that acts as a crosslinking promoter by the catalytic effect of oxidation reaction. Dimethyldithiocarbamic acid was preferably 0.94% by weight as a photolysis accelerator having a bad odor and having an unsuitable color for producing a transparent film. Iron chloride used 0.41% by weight. In the present invention, they react with light to generate free radicals, which act as photocatalytic promoters, thereby triggering radical reactions.

In the present invention, iron stearate, magnesium stearate, stearic acid were used as an initiator. Iron stearate or magnesium stearate serves as an initiator to help initiate the reaction of the stearic acid component. After this, iron stearate, magnesium stearate, and calcium stearate serve as an oxidation promoter.

The initiator generates free radicals by repeating the peroxide and redox reactions, and has an autooxidation action due to these highly reactive free radicals. The automatic oxidation allows light or heat to be used as the reaction energy to initiate a radical reaction. The resin composition of the present invention preferably contains 2.83% by weight of iron stearate and 1.9% by weight of magnesium stearate. Magnesium stearate also serves as a dispersant for calcium carbonate.

Stearic acid is a typical fatty acid glyceride, while the melting temperature is low as about 72 ℃ to produce a metal stearate, such as iron stearate, calcium stearate, zinc stearate to control the photodegradability. The surface of the calcium carbonate hydrophilic particles are converted to hydrophobicity and used as lubricants and biodegradants at the same time.

The resin composition of this invention contains a polyvinyl alcohol and a polyvinyl alcohol plasticizer. As the polyvinyl alcohol plasticizer, glycerin, glycerol, benzoyl peroxide (initiator), and carboxymethyl cellulose are used. The glycerin, glycerol, benzoyl peroxide, carboxymethyl cellulose is a raw material used to plasticize polyvinyl alcohol and exhibits properties as a biodegradable or biodegradable agent.

Glycerol can preserve the composite decomposable resin composition in a gel state, but, due to its unique viscosity, it was preferably able to complete plasticization at 0.4 wt%. Glycerin was used at an increased amount of 2.8% by weight for optimum polyvinyl alcohol plasticization. Benzoyl peroxide (BPO) comprises 0.013% by weight as a representative peroxide.

Benzoyl peroxide primarily serves to activate polyvinyl alcohol plasticizers and, when mixed with polyolefin resins, initiates grafting of maleic anhydride. Peroxides may be selected from benzoyl peroxide, di-tributyl peroxide, tributyl hydroperoxide, nikumylperoxide, 2,5-dimethyl-2,5-di (t-butylperoxide) hexane, or 1,3-Bis (t-butylperoxy-isopropyl) benzene etc. are mentioned, This invention is not limited to these.

Biodegradants or biodegradants of the resin composition of the present invention include PE wax, sorbitol, sodium alginate, glycerin, glycerol, polyethylene glycol, carboxymethylcellulose, methyl salicylic acid, stearic acid.

As a biodegradable raw material that can be decomposed by itself, 0.1 wt% of sorbitol and 0.1 wt% of methyl salicylic acid were used in the present invention. Carboxymethyl cellulose is also used for biodegradation or biodegradation, and 0.1 wt% of CMC-Na is used. Alginic acid is widely used in the form of water-soluble sodium alginate because it is insoluble in water, and microorganisms are decomposed using 0.06% by weight. In addition, polyethylene glycol is used as a yeast culture agent in the present invention was used 0.4% by weight.

The present invention does not perform a polymerization reaction including an esterification reaction and a polycondensation reaction separately using the microbial decomposer raw materials, and separately weighs the microbial decomposer raw materials in a raw state. Since it is a simple manufacturing method that is used by mixing and then extruded, no expensive cost is generated and in this process, the microbial decomposers are used for emulsifiers, stabilizers, thickeners, crosslinking agents, crosslinking accelerators and polyvinyl alcohol plasticizers.

The PE wax has the advantage of low melting point and when the composition is prepared using an extruder used a lubricant 6% by weight because it also has a function of biodegrading itself at low molecular weight. The role of lubricant is PE wax, stearic acid, magnesium stearate, etc. When using fatty acid-based lubricant, it has the advantage of showing affinity with inorganic materials such as calcium carbonate, and has the advantage of surface modification by coating hydrophilic inorganic surface. It serves to facilitate the mixing of the additives.

Lubricant is an additive used to reduce and smooth the friction between composition materials in raw material mixing process or melt extrusion process. When many inorganic materials such as calcium carbonate are added, the temperature is increased due to frictional heat with screws. The organic additives are carbonized and pressed to the surface of the screw to eliminate the occurrence of defects. Another method is to use antioxidants to solve this problem.

Borax is a material that can be used to modify polyvinyl alcohol hydrophobicly, which acts as an emulsifier in the present invention and is well soluble in glycerin and the addition amount is 0.1% by weight.

Anionic surfactants include sodium lauryl sulfate and lauryl benzene sulfonic acid sodium. Representative anionic surfactants commonly used as emulsifiers and dispersants are adsorbed at the interface between hydrophilic and hydrophobic raw materials to reduce their surface tension and allow them to be mixed to enhance compatibility. In the present invention, sodium lauryl sulfate was added 0.2% by weight, and the amount of sodium lauryl benzene sulfonate added was 0.1% by weight.

The composition according to the present invention may preferably further comprise a decomposition period adjusting agent which can control the decomposition period according to the use, the amount is preferably 0.001 to 5 parts by weight based on 100% by weight of the matrix resin. If it is less than 0.001 parts by weight, there is little photolysis control effect, and if it exceeds 5 parts by weight, there is a disadvantage in that photolysis does not proceed sufficiently within one year.

The masterbatch composition manufacturing method of this invention is demonstrated.

Raw material preparation step of measuring and preparing the master batch composition of the present invention; Polyvinyl alcohol, benzoyl peroxide, glycerin, glycerol, and carboxymethyl cellulose raw materials are added together to the stirrer, followed by mixing for 4 to 6 minutes and preferably 5 minutes at 1 to 30 ° C. at 600 to 1000 RPM for plasticizing modified polyvinyl. Polyvinyl alcohol plasticization step of obtaining an alcohol mixture; Mixing step of uniformly mixing all of the remaining raw materials into the plasticized modified polyvinyl alcohol mixture sequentially; The mixture obtained through the mixing step is continuously controlled to a temperature of 100 to 170 ℃ and added to the extruder and melt kneading and then slowly cooled at 1 to 30 ℃ or quenched in a cooling tank of 1 to 10 ℃ 2 to 3 mm pellets Prepare masterbatches in form.

In the case of polyvinyl alcohol resin, unlike the general thermoplastic resin, melting point and pyrolysis temperature are very similar, so film forming by simple heat melting method is impossible. After preparing the compound using the masterbatch, the particles deposited on the surface of the film extracted in the inflation process were analyzed with polyvinyl alcohol and plasticization is required to remove them. In addition, since polyvinyl alcohol has low tensile strength and hydrophilicity, compatibility with polyolefin resins is very weak, and polyvinyl alcohol is added after plasticization due to strong hygroscopicity of calcium carbonate added together.

By using an extruder having a plurality of inlets for inputting the raw material, plasticization and melt kneading can be simultaneously performed in a batch process without pre-plasticizing in a stirrer. That is, by using an extruder having a plurality of inlet in series along the advancing direction of the extruder, polyvinyl alcohol and polyvinyl alcohol plasticizer are introduced through the first inlet to plasticize the polyvinyl alcohol. By injecting the remaining components of the resin composition through another inlet downstream after plasticization, the mixing and thermal fusion and kneading between the components can be done simultaneously.

The polyvinyl alcohol plasticizer is selected from the group consisting of glycerin, glycerol, benzoyl peroxide, carboxymethyl cellulose, one or two or more. The plasticizer and polyvinyl alcohol can be added together and mixed for 4 to 6 minutes, preferably 5 minutes, to obtain plasticized polyvinyl alcohol. As such, the polyvinyl alcohol may be plasticized in advance to obtain a homogeneous mixed composition between the polyvinyl alcohol and the remaining raw materials of the resin composition and to increase mutual melting and bonding strength.

The polyolefin has poor compatibility with polyvinyl alcohol, so that when the polyolefin and polyvinyl alcohol are mixed, a separate interface is formed at the interface of each raw material, thereby deteriorating the mechanical properties of the molded article. Therefore, in order to improve the compatibility of polyvinyl alcohol and polyolefin, a material having both nonpolar functional groups compatible with polyolefin and polar functional groups compatible with polyvinyl alcohol in one molecular unit may be used as a compatibilizer.

After the mixing step, low density polyethylene (LDPE-g-MA, melt index: 5g / 10min) grafted with maleic anhydride is added through an inlet during the melt extrusion process. A low density polyethylene grafted with maleic anhydride is added to melt kneading, followed by cooling to prepare a masterbatch in pellet form. Films containing 6.1 wt% or more of low density polyethylene grafted with maleic anhydride are degraded due to a decrease in elongation, and when not added, film formation is not smooth.

The compound batch manufacturing method of this invention is demonstrated.

200 to 600 parts by weight, preferably 400 parts by weight of a high density polyethylene resin is further mixed and melt-extruded and then cooled to prepare a compound batch in pellet form based on 100 parts by weight of the masterbatch composition. This is a range in which the amount of compound decomposition can be exhibited well. If more than 200 parts by weight of the compound is decomposed, the amount of compound decomposition is less than 600 parts by weight.

Preferably, the high density polyethylene may have a melt index of 0.04 to 0.05 g / 10 min and a density of 0.9 to 1 g / cc. More preferably the high density polyethylene resin has a melt index of 0.045 g / 10 min and a density of 0.941 to 0.970 g / cc, in particular 0.956 g / cc. If the melt index is high, the injection moldability is excellent, and if it has a low index, it is advantageous for extrusion, so 0.04 to 100g / 10min may be selected according to the molding method and raw materials such as extrusion and injection.

A method for producing various molded articles from the masterbatch or compound composition of the present invention will be described.

Using the masterbatch or compound composition, films, sheets, bottles, injection molded articles, etc. may be conventionally formed by extrusion molding, inflation molding, injection molding, blow molding, or the like. As such, various molded products may be manufactured using molding machines manufactured in the art. In particular, the composition of the present invention is for disposable plastic bags, plastic shopping bags, mulching film, food waste composting bags and the like, which can be produced by extrusion blow method, disposable cups, trays, which can be produced by injection method, It is suitable for manufacture of forks and the like.

Hereinafter, the present invention will be described in more detail with reference to Examples. These examples are only for illustrating the present invention, it will be apparent to those skilled in the art that the scope of the present invention is not to be construed as being limited by these examples.

According to an embodiment of the invention The composite-degradable polyolefin resin composition of the present invention is a low density polyethylene (LDPE) 14% by weight, grafted LDPE (LDPE-g-MA) 5% by weight, calcium carbonate 32% by weight, pellet calcium carbonate (Pellet CaCO) 20 % By weight, 0.5% by weight white pigment, 6% by weight PE wax, 0.02% by weight acetylacetonate, 0.94% by weight dimethyldithiocarbamic acid, 0.41% by weight iron chloride, ferric stearate 2.83 % By weight, 1.9% by weight of magnesium stearate, 0.6% by weight of stearic acid, 9.4% by weight of polyvinyl alcohol (PVA), 2.8% by weight of glycerine, 0.4% by weight of Glyceryl Monostearate, polyethylene 0.4% by weight of glycol (PEG), 0.1% by weight of sorbitol, 0.1% by weight of borax, 0.1% by weight of carboxymethyl cellulose (CMCNa), 0.2% by weight of sodium lauryl sulfate, sodium laurylbenzenesulfonate ( lauryl benzene sulfonic acid sodium) 0. 1 wt%, 0.013 wt% benzoyl peroxide (BPO), 0.06 wt% sodium alginate, 0.1 wt% methyl salicylic acid, and 2 wt% zeolite.

20 wt% of pellet type calcium carbonate (Pellet CaCO3) in the polyolefin-based resin composition includes 6 wt% of low density polyethylene, so that the total amount of low density polyethylene means 20 wt%. In addition, in the present invention, 5% by weight of low density polyethylene (LDPE-g-MA) modified with maleic anhydride is added.

Example 1 Preparation of Masterbatch of Multidegradable Polyolefin Resin

Polyvinyl alcohol 940gr, benzoyl peroxide 1.3gr, glycerin 280gr, glycerol 40gr, carboxymethylcellulose 10gr was added to the stirrer and then mixed at room temperature at 600 to 1000 RPM for about 5 minutes to obtain a plasticized modified polyvinyl alcohol mixture. Low Density Polyethylene (Hanhwa 830, Melt Index: 2g / 10min, Density: 0.921g / cc) 1400gr, Calcium Carbonate (FC-1) 3200gr, Pellets Calcium Carbonate 2000gr, Pigment (R 996 / R) 50gr, PE Wax 600gr, cobaltacetylacetonate 2gr, dimethyldithiocarbamic acid 94gr, iron chloride 41gr, iron stearate 283gr, magnesium stearate 190gr, stearic acid 60gr, Polyethylene glycol4000 40gr, sorbitol 10gr, borax 10gr, sodium lauryl sulfate 20gr, sodium laurylbenzenesulfonate 10gr, Mixes 1.3 gr of benzoyl peroxide, 6 gr of sodium alginate, 1 gr of methyl salicylic acid, 200 gr of zeolite (APNC 20) and 500 gr of grafted low density polyethylene (melt index: 5 g / 10 min) After further mixing for 50 minutes at 600 ~ 1000 RPM conditions at room temperature. The obtained mixture was continuously fed into a twin screw extruder consisting of 10 zones, melt kneaded at a temperature of 100 to 170 ° C, and cooled to prepare a masterbatch in pellet form.

Example 2 Compound Batch Preparation of Complex Degradable Polyolefin-Based Resin

40 kg of a high density polyethylene resin (Lotte FL7100, melt index: 0.045 g / 10 min, density: 0.956 g / cc) was mixed with 10 kg of the masterbatch prepared in Example 1, and melted in the extruder and the operating conditions of Example 1 After kneading, the mixture was cooled to prepare a compound batch in pellet form.

Example 3 Preparation of a Composite Degradable Polyolefin-Based Resin Film

Using 50 kg of the compound batch prepared in Example 2 to prepare a plastic bag using a conventional film molding machine.

As a result, the biodegradable plastic bag, which is a completed molded product, was commissioned by FITI tester to analyze the biodegradability. "KS M ISO 14855-1 Determination of aerobic biodegradability of plastic materials under composting conditions: method by carbon dioxide analysis- Part 1 The biodegradability of the samples was determined by titration as a general method. The results of comparative analysis of cellulose and phosphorus biodegradable bags, which are similar to those of Table 1, show that volatile solid content, TOC, organic carbon ratio, and ThCO2 are similar.

division	Dry Solids Content (%)	Volatile Solids Content (%)		TOC (%)	Organic Carbon Ratio [C TOT (g / g)]	ThCO2 (g / vessel)
		Drying contrast	Wet contrast
Cellulose	75.4	87.3	83.3	44	0.461	25.931
Biodegradable envelopes	99.5	85.6	85.3	45	0.452	27.415

In addition, the aerobic biodegradability was measured by measuring the amount of carbon dioxide generated in the composting conditions by titration method. As a result of measurement for 55 days, the biodegradability of the test substance compared to the standard material is shown in Table 2, FIG. 1, and FIG. 2, respectively.

division	Average biodegradation (%) calculated by carbon dioxide emissions	Trial Day	Observation
Cellulose	84.94	45	No specific matters such as water content, color, smell of inoculum
Biodegradable envelopes	35.57	45	No specific matters such as water content, color, smell of inoculum
Biodegradability of Test Substance (%)	Biodegradable envelopes		41.87

Table 2 demonstrates that the biodegradable bags have a good biodegradability of 41.87% compared to the standard. 1 is a (a) cumulative carbon dioxide generation curve, (b) biodegradation curve of the standard (cellulose), Figure 2 is (a) carbon dioxide accumulation curve, (b) biodegradation curve of the biodegradable envelope It can be seen that about 45% of this standard is biodegradable.

Example 4 Recycling Extrusion Experiment of Biodegradable Polyolefin-Based Biodegradable Plastic Bags

High density polyethylene pellet type resin (Lotte FL7100, Melt index: 0.045 g / 10min, Density: 0.096 g / cc) purchased in new form on the market 1.5kg recycled bag using at least one commercially available HDPE bag in addition to 8kg Kg and 0.5 Kg of a biodegradable plastic bag, which is a molded product of Example 3, were mixed to prepare a plastic bag using a conventional film molding machine.

Accordingly, the result of the measurement of the tensile strength, the elongation rate and the tear strength after aging according to KPS M 1013 and KPS M 1015 was obtained by requesting the FITI tester for the finished plastic bag.

Comparative Example 1. Recycling Extrusion Experiment of PLA Biodegradable Plastic Bag

In addition to 8Kg of high density polyethylene pellet type resin used in Example 4, 1.5Kg of recycled bags using at least one commercially available HDPE bag and 80g of PLA biodegradable plastic bags (Saehan Polymer Co., Ltd.) While trying to produce a plastic bag using a conventional film molding machine by mixing the odor of the bag melts during the extrusion process, the melt was not extruded by the extrusion die despite the overload in the extruder.

Comparative Example 2. Recycling Extrusion Experiment of General Plastic Bag

The commercially available HDPE general plastic bag 8Kg was remelted and extruded using a conventional film molding machine to prepare a plastic bag, and the physical properties thereof were measured in the same manner as in Example 4.

Example (Certificate Sample Number)	Tensile Strength (N / ㎡)	Elongation (%)	Tear Strength (N / mm) after Notch
			usually	Folded
Example 4 (# 2)	59.3	400	117	102
Comparative Example 2 (# 3)	43.1	338	86	81
Comparative Example 1 (PLA Recycled Bag)	Extrusion work impossible

Table 3 demonstrates that the recyclability of the biodegradable plastic bags according to the present invention is excellent.

In the art of producing general plastic bags, a certain amount of excess is generated during the altar process, and in order to recycle it, an additional 10 to 20 parts of additional bags are mixed with 100 parts by weight of a high density polyethylene pellet type resin as a main material of plastic bags. I'm doing it.

In Comparative Example 1, when the PLA recycled bag is added to the existing high-density polyethylene bag, re-melt extrusion is impossible and cannot be recycled. This causes a problem in that a separate biodegradable separator is additionally installed in the home separator. .

On the other hand, the physical property results of Example 4, despite the recycled plastic bags in which the biodegradable plastic bags of the present invention is added to the conventional commercialized plastic bags, is similar to the physical properties of the general plastic bags of Comparative Example 2 will be no problem in commercialization Judging.

Since the multi-degradable polyolefin-based biodegradable plastic bag according to the present invention can be remelted to produce a finished molded article, it is possible to solve the problem of recycling existing biodegradable plastic and cost reduction effect occurs.

As mentioned above, specific portions of the present disclosure have been described in detail, and it is apparent to those skilled in the art that such specific techniques are merely preferred embodiments, and thus the scope of the present disclosure is not limited thereto. something to do. Thus, the substantial scope of the present invention will be defined by the appended claims and their equivalents.

Claims (7)

1. Polyolefin resin, grafted polyolefin resin, powdered calcium carbonate, pellet calcium carbonate, dehumidifying agent, photodegradant, initiator, polyvinyl alcohol, biodegradable or biodegradable agent, polyvinyl alcohol plasticizer, anionic surfactant, lubricant And a decomposable polyolefin resin composition comprising borax.
2. The method of claim 1,

   The polyolefin-based resin is a multi-degradable polyolefin resin composition, characterized in that at least one mixture selected from the group consisting of low density polyethylene, linear low density polyethylene, polypropylene.
3. The method of claim 1,

   The grafted polyolefin-based resin is at least one mixture selected from the group consisting of grafted low density polyethylene, grafted high density polyethylene, grafted linear low density polyethylene, grafted polypropylene Resin composition.
4. The method of claim 1,

   The dehumidifying agent is a composite decomposable polyolefin resin composition, characterized in that at least one mixture selected from the group consisting of zeolite, bentonite, diatomaceous earth, silica gel, activated carbon and super absorbent polymer.
5. The method of claim 1,

   A composite decomposable polyolefin resin composition compound further comprising 200 to 600 parts by weight of a high density polyethylene resin based on 100 parts by weight of the polyolefin resin composition.
6. The method of claim 5,

   The multi-degradable polyolefin-based resin composition molded article is molded using at least one of extrusion molding, inflation molding, injection molding and blow molding using the compound compound polyolefin-based resin composition.
7. (1) adding polyvinyl alcohol and polyvinyl alcohol plasticizer to the stirrer and mixing to plasticize the polyvinyl alcohol;

   (2) polyolefin resin, grafted polyolefin resin, powdered calcium carbonate, pellet type calcium carbonate, dehumidifying agent, photodegradant, initiator, biodegradable or biodegradable agent, anionic surfactant, lubricant in the plasticized polyvinyl alcohol Adding borax sequentially; And

   (3) adding the mixture to an extruder, followed by melting and kneading the mixture, followed by cooling.

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