WO2016003069A1

WO2016003069A1 - Copolymer of starch and thermoplastic polymer, method for preparing same, and use thereof

Info

Publication number: WO2016003069A1
Application number: PCT/KR2015/005173
Authority: WO
Inventors: 이세나; 함충현; 송은범
Original assignee: 대상 주식회사
Priority date: 2014-06-30
Filing date: 2015-05-22
Publication date: 2016-01-07
Also published as: KR101592894B1; KR20160002546A

Abstract

The present invention relates to a graft copolymer of starch and a thermoplastic polymer, and provides a copolymer of starch and a thermoplastic polymer, the copolymer being characterized in that the graft copolymerization of the starch and the thermoplastic polymer occurs by an unsaturated carboxylic acid. In cases where starch and a thermoplastic polymer, which are constituent components of a starch-based hot melt adhesive of the prior art, are replaced with the copolymer of starch and a thermoplastic polymer of the present invention, the storage stability of the starch-based hot melt adhesive can be improved, such as preventing the phase separation and minimizing the viscosity change in the starch-based hot melt adhesive. The starch-based hot melt adhesive of the present invention exhibits physical properties at equivalent levels to those of commercial products not containing starch, of the prior art.

Description

Copolymers of starch and thermoplastic polymers, methods for their preparation and uses thereof

One aspect of the invention relates to copolymers of starch and thermoplastic polymers, and more particularly starch-based hot melt adhesives, such as preventing phase separation of starch-based hot melt adhesives or minimizing viscosity changes when used as components of starch-based hot melt adhesives. The present invention relates to a copolymer of a starch and a thermoplastic polymer capable of improving the storage stability.

Another aspect of the present invention relates to a method for preparing a copolymer of starch and thermoplastic polymer that can improve the storage stability of starch-based hot melt adhesives.

Another aspect of the present invention relates to a starch-based hot melt adhesive comprising a copolymer of starch and a thermoplastic polymer and a method for producing the same.

Adhesion refers to a state in which two surfaces are bonded by an attractive force between molecules, atoms, and ions. Adhesion is widely applied in our daily lives not only for daily necessities such as tapes and bonds, but also for automobiles and cutting-edge semiconductor devices. In recent years, the demand for adhesives in each field has been diversified due to the remarkable industrial development.

The polymer adhesive may be classified into a chemical reaction type, a solvent type, a hot melt type and the like according to the solidification process. Among them, hot melt adhesive is a representative example that is easy to use and can meet the requirements of the emerging environment.

Hot melt adhesive (hot melt adhesive) is a solid material at room temperature without melting or dispersing in a solvent to melt only 100% of the heat in an adhesive to use as a liquid. Hot-melt adhesives were first developed by DuPont in the 1960s as an ethylene-vinylacetate resin (EVA), and have the advantages of high productivity, eco-friendly features, broad applicability, and re-adhesion through process automation. The growth rate is high. The hot melt adhesive is applied to the surface to be adhered in a molten state and then cooled and solidified by dissipating heat to and around the surface of the adherend. Hot melt adhesive is characterized by a small working space and fast adhesion speed without the need for drying process compared to other solvent adhesives or water dispersion adhesives. High-speed adhesion enables automation of production lines and increased productivity, resulting in significant economic benefits such as improved productivity, reduced labor costs, and reduced amount of raw materials due to coating amount control. Hot melt adhesives have been applied in many fields such as packaging, bookbinding, construction, woodworking, automotive, textile, electrical / electronics, etc.

Conventional commercial hot melt adhesives generally include ethylene-vinylacetateyl series, polyolefin series, styrene block copolymerization series, polyamide series, polyester series, urethane series (reactive hotmelt), and the like, and the base resin is a hotmelt adhesive. Among the physical properties of the most important adhesion and cohesion has a big impact. Conventional commercial hot melt adhesives lack the environmentally friendly properties such as the generation of a large amount of volatile organic compounds (VOC) in the manufacturing process or use process because the base resin is mainly composed of petroleum-based materials, There is a problem that manufacturing costs can be increased due to external factors such as insecure supply and demand of materials and depletion of petroleum materials. In addition, the conventional commercial hot melt adhesive has a problem in that workability is poor, such as a thread blowing phenomenon occurs during use. Therefore, in consideration of environmental friendliness, stable supply of supplies, cost value, etc., it is necessary to replace all or part of the basic resin, which is a major component of the hot melt adhesive, with biomass, in particular starch, which can be infinitely regenerated.

Korean Patent Publication No. 10-1145374 with respect to starch-based hot melt adhesive is a composition comprising a starch, a thermoplastic polymer, a tackifier, and a plasticizer, wherein the starch is contained in 30 to 65% by weight based on the total weight of the composition The thermoplastic polymer may be included in an amount of 20 to 150 parts by weight based on 100 parts by weight of starch, and may include ethylene-vinyl acetate copolymer (Ehtylene Vinyl Acetate Copolymer, EVA), polyvinyl acetate, polyvinyl alcohol, and ethylene. It is composed of at least one selected from the group consisting of -acrylic acid copolymer, and ethylene-methacrylic acid copolymer, the tackifier is included in 25 to 125 parts by weight relative to 100 parts by weight of starch and dicyclopentadiene as a monomer (dicyclopentadiene Hydrogenated hydrocarbon resin, including, DCPD), the plasticizer is 10 to 40 compared to 100 parts by weight of starch This amount may for starch-based hot-melt adhesive composition characterized in that an amount is disclosed. In addition, the Republic of Korea Patent Publication No. 10-1315784 is a composition comprising a starch, a thermoplastic polymer, a tackifier, a plasticizer, and an adhesion promoter, wherein the starch is contained in 25 to 55% by weight based on the total weight of the composition, The thermoplastic polymer is included in an amount of 20 to 150 parts by weight based on 100 parts by weight of starch and is an ethylene-vinyl acetate copolymer (Ehtylene Vinyl Acetate Copolymer, EVA), polyvinyl acetate, polyvinyl alcohol, ethylene-acrylic acid It is composed of one or more selected from the group consisting of a copolymer, and an ethylene-methacrylic acid copolymer, the tackifier is included in 25 to 125 parts by weight based on 100 parts by weight of starch, the plasticizer is 10 to 100 parts by weight of starch It is included in about 40 parts by weight, the adhesion promoter is included in 0.1 to 10 parts by weight relative to 100 parts by weight of starch and polyacrylamide (Polyacrylamide), A starch-based hot melt adhesive is disclosed which is composed of one or more selected from the group consisting of polyvinylamide, polyethyleneimine, epoxidized polyamide, and glyoxylated polyacrylamide. In addition, the Republic of Korea Patent Publication No. 10-1276294 is a composition comprising a starch, a thermoplastic polymer, and a tackifier, the starch is contained in 20 to 60% by weight based on the total weight of the composition, the thermoplastic polymer starch 20 to 200 parts by weight, based on 100 parts by weight of ethylene-vinyl acetate copolymer (Ehtylene Vinyl Acetate Copolymer, EVA), polyvinyl acetate (Polyvinyl acetate), polyvinyl alcohol, ethylene- acrylic acid copolymer, and ethylene It is composed of one or more selected from the group consisting of methacrylic acid copolymer, the tackifier is included in 25 to 150 parts by weight relative to 100 parts by weight of starch, and composed of a combination of aliphatic hydrocarbon resin and hydrogenated hydrocarbon resin A starch-based hot melt adhesive is disclosed. However, the starch and the thermoplastic polymer constituting the conventional starch-based hot melt adhesive have a lack of compatibility, and thus there is a problem in that a precipitate occurs or phases are separated during the manufacturing or storage process of the starch-based hot melt adhesive. Viscosity changes can be severe and adversely affect quality.

The present invention is derived under the conventional technical background, and an object of the present invention is to provide a copolymer of starch and thermoplastic polymer which can improve the storage stability of starch-based hot melt adhesive when used as one component of starch-based hot melt adhesive. To provide.

Another object of the present invention is to provide a method for preparing a copolymer of starch and a thermoplastic polymer capable of improving the storage stability of the starch-based hot melt adhesive.

It is still another object of the present invention to provide a starch-based hot melt adhesive having improved storage stability such as preventing phase separation or minimizing viscosity change and a method of manufacturing the same.

The inventors of the present invention can prevent the separation of the starch-based hot melt adhesive phase and minimize the change in viscosity when the starch and the thermoplastic polymer, which is a component of the conventional starch-based hot melt adhesive, are replaced with a copolymer of starch and the thermoplastic polymer. The present invention has been accomplished by discovering that the storage stability of starch-based hot melt adhesives can be improved.

In order to solve the object of the present invention, the present invention is a graft copolymer of starch and a thermoplastic polymer, wherein the graft copolymerization of the starch and the thermoplastic polymer is formed through an unsaturated carboxylic acid, Provided are copolymers of thermoplastic polymers.

In order to solve the other object of the present invention, the present invention comprises the steps of (a) reacting starch and unsaturated carboxylic acid in the presence of a plasticizer to form a first composition comprising a starch bonded to unsaturated carboxylic acid; And (b) adding a wax and a thermoplastic polymer to the first composition and reacting the unsaturated carboxylic acid bonded to the starch and the thermoplastic polymer in the presence of a radical reaction initiator to obtain a second composition comprising a graft copolymer of starch and the thermoplastic polymer. It provides a method of preparing a copolymer of starch and a thermoplastic polymer comprising the step of forming.

In order to solve another object of the present invention, the present invention provides a starch-based hot melt adhesive in the form of a composition comprising a copolymer of the starch and the thermoplastic polymer, a plasticizer, a wax and a tackifier. At this time, the production method according to a preferred example of the starch-based hot melt adhesive (a) reacting the starch and unsaturated carboxylic acid in the presence of a plasticizer to form a first composition comprising a starch bonded to the unsaturated carboxylic acid; (b) adding a wax and a thermoplastic polymer to the first composition and reacting the unsaturated carboxylic acid bonded to the starch and the thermoplastic polymer in the presence of a radical reaction initiator to form a second composition comprising a graft copolymer of starch and the thermoplastic polymer. Forming; And (c) adding and mixing a tackifier to the second composition to form a third composition.

In the case of replacing starch and thermoplastic polymers, which are components of conventional starch-based hot melt adhesives, with the copolymer of starch and thermoplastic polymers of the present invention, starch-based hot melt adhesives can prevent phase separation and minimize viscosity changes. The storage stability of the hot melt adhesive can be improved. The starch-based hot melt adhesive of the present invention exhibits the same level of physical properties as commercial products that do not contain conventional starch.

1 schematically shows the structure of a copolymer of starch and a thermoplastic polymer according to a preferred embodiment of the present invention.

Figure 2 is a photograph of the starch-based hot melt adhesive prepared in Preparation Example 1.

3 is a photograph of the starch-based hot melt adhesive prepared in Comparative Production Example 4.

As used herein, the term "unsaturated carboxylic acid" is a generic term for organic compounds having at least one ethylenically unsaturated bond and at least one carboxyl group in the molecule.

As used herein, the term "unsaturated dicarboxylic acid" is a general term for an organic compound having at least one ethylenically unsaturated bond and at least two carboxyl groups in a molecule, and includes anhydrides of unsaturated dicarboxylic acids.

Hereinafter, the present invention will be described in detail.

Copolymer of Starch and Thermoplastic Polymer

One aspect of the present invention is used as one component of the starch-based hot melt adhesive, and can prevent the phase separation of the hot-melt adhesive and minimize the change in viscosity, such as starch to improve the storage stability of the starch-based hot melt adhesive It relates to a copolymer of a thermoplastic polymer.

The copolymer of the starch and the thermoplastic polymer according to the present invention is a graft copolymer of the starch and the thermoplastic polymer, specifically, the graft copolymerization of the starch and the thermoplastic polymer has an ethylenically unsaturated bond (hereinafter referred to as' unsaturated carboxylic acid Or an anhydride thereof. Thermoplastic polymers commonly used in hot melt adhesives consist of monomers with ethylenically unsaturated bonds, which are difficult to chemically bond directly with the hydroxyl groups of the starch. The inventors of the present invention have introduced unsaturated carboxylic acids or anhydrides thereof into the linker to graf the thermoplastic polymer to the starch. 1 schematically shows the structure of a copolymer of starch and a thermoplastic polymer according to a preferred embodiment of the present invention. As shown in FIG. 1, in the copolymer of starch and thermoplastic polymer according to the present invention, the carboxyl group of the unsaturated carboxylic acid forms an ester bond with the hydroxyl group of the starch, and the thermoplastic polymer (particularly, the terminal of the thermoplastic polymer) is unsaturated carboxylic acid. It is formed by chemically bonding at the ethylenically unsaturated bond position present within.

At this time, the type of starch is not greatly limited, and includes, for example, corn starch, waxy corn starch, tapioca starch, potato starch, sweet potato starch, rice starch, wheat starch and the like. In addition, starch includes unmodified starch or specific modified starch. Unmodified starch is a starch obtained from a conventional starch production process, and is a modified starch (eg, acid treated starch, enzyme treated starch, whose physical properties (viscosity, thermal stability, freeze thaw stability) have been changed by chemical treatment and heat treatment). Starch oxide, acetyladipic acid starch, acetyl phosphate starch, octenyl zucchini starch, phosphate starch, monophosphate starch, phosphate starch, starch acetate, hydroxypropyl phosphate starch, hydroxypropyl starch and the like. Is a contrasting concept. The starch constituting the copolymer of the starch and the thermoplastic polymer according to the present invention is preferably a modified starch whose polymerization degree is reduced by acid treatment or enzyme treatment in consideration of the ease of reaction and storage stability of the starch-based hot melt adhesive described later. Modified starch with reduced degree of polymerization usually decreases the viscosity of the gelatinous liquid. Such modified starch is also known as acid-treated starch (also referred to as acid-treated starch or thin boiling starch) and enzyme-treated starch (dextrin). Is also included in the enzyme-treated starch). The modified starch having reduced polymerization degree of starch is preferably in the range of 10 to 100 centipoise (cPs) of the viscosity of 20% by weight gelatinous liquid at 50 ℃, 20 to 80 centipoise (cPs) of More preferably in the range.

In addition, the thermoplastic polymer is not particularly limited as long as it is generally used in a hot melt adhesive, for example, ethylene-vinyl acetate copolymer (Ehtylene Vinyl Acetate Copolymer, EVA), polyvinyl acetate (polyvinyl acetate), poly Selected from the group consisting of vinyl alcohol, ethylene-acrylic acid copolymer, ethylene-methacrylic acid copolymer, ethylene-butylacrylate copolymer, ethylene-ethylhexylacrylate copolymer and ethylene-methylacrylate copolymer It may be one or more kinds, and among these, an ethylene-vinylacetate copolymer (Ehtylene Vinyl Acetate Copolymer, EVA) is preferred. In addition, the thermoplastic polymer may be selected from thermoplastic polyolefins. The thermoplastic polyolefin may be a homogeneous polymer formed of one kind of monomer, such as polyethylene or polypropylene, or may be a copolymer formed of two or more different monomers selected from ethylene, propylene, butene, hexene, and octene. It is preferable to chain. In particular, the thermoplastic polyolefin may be a copolymer of ethylene and an alpha olefin having 4 to 20 carbon atoms (for example, 1-butene, 1-hexene, 1-octene, or a copolymer of propylene and alpha olefin having 4 to 20 carbon atoms). It is preferably obtained by metallocene-catalyzed polymerization, such as ethylene-alpha olefin copolymer or propylene obtained by metallocene-catalyzed polymerization. -Alpha alpha olefin copolymer (propylene-alpha olefin copolymer) is also called polyolefin plastomer, which is a material in which plastic and elastomer are harmonized.Polyolefin platopolymer polymerized by metallocene catalyst Mercer's commercial products include Dow Chemical's Affinity GA 1900, Affinity GA 1950, etc. The starch and heat of the present invention The weight ratio of starch to thermoplastic polymer in the copolymer of the calcined polymer is not particularly limited, and considering the storage stability of the starch-based hot melt adhesive described below, it is preferably from 0.5: 1 to 1: 5, preferably from 1: 1 to 1: 5. More preferably, 1: 2 to 1: 4.

In addition, the unsaturated carboxylic acid or anhydride thereof is not particularly limited as long as it has at least one ethylenically unsaturated bond and at least one carboxyl group in the molecule, for example acrylic acid, methacrylic acid, maleic acid (Maleic acid) ), Fumaric acid, glutaconic acid, anhydride, traumatic acid, muconic acid, citraconic acid and citric acid and their anhydrides. It may be one or more, and considering the ease of reaction and storage stability of the starch-based hot melt adhesive described later, maleic acid, maleic acid, fumaric acid, glutaconic acid, anhydride, traumatic acid (Traumatic acid) acid), muconic acid, citraconic acid and at least one unsaturated dicarboxylic acid selected from the group consisting of anhydrides or at least one unsaturation It is preferable that it is an anhydride of a converted dicarboxylic acid. The weight ratio of the unsaturated carboxylic acid (or anhydride thereof), especially the unsaturated dicarboxylic acid (or anhydride thereof), used as a starch to linker in the copolymer of the starch and the thermoplastic polymer of the present invention is not particularly limited, and the starch system described below In view of the storage stability of the hot melt adhesive, it is preferably 1: 0.01 to 1: 0.2, more preferably 1: 0.04 to 1: 0.1.

Method for preparing starch-thermoplastic polymer copolymer

Another aspect of the present invention relates to a method for preparing a copolymer of starch and a thermoplastic polymer (hereinafter referred to as 'starch-thermoplastic polymer copolymer'). The method for preparing a starch-thermoplastic polymer copolymer according to the present invention comprises the steps of (a) reacting starch with an unsaturated carboxylic acid or anhydride thereof in the presence of a plasticizer to form a first composition comprising starch to which unsaturated carboxylic acid is bound. ; And (b) adding a wax and a thermoplastic polymer to the first composition and reacting the unsaturated carboxylic acid bonded to the starch and the thermoplastic polymer in the presence of a radical reaction initiator to obtain a second composition comprising a graft copolymer of starch and the thermoplastic polymer. Forming a step. In the method for preparing a starch-thermoplastic polymer copolymer according to the present invention, the contents of the starch, the unsaturated carboxylic acid, and the thermoplastic polymer are the same as those described above for the starch-thermoplastic polymer copolymer, and thus only the newly added parts will be described.

In the step (a) of the method for preparing a starch-thermoplastic polymer copolymer according to the present invention, an ester bond is formed between the hydroxyl group present in the starch and the carboxyl group present in the unsaturated carboxylic acid to form a hydroxyl group of the starch as an unsaturated carboxylic acid. Substituted modified starch is produced. The reaction of step (a) is carried out in the presence of a plasticizer in terms of improving the reaction between the starch and the unsaturated carboxylic acid and in simplifying the starch-based hot melt adhesive manufacturing process described later. The plasticizer is used to impart flexibility and adhesion to the polar polymer, and the kind thereof is not particularly limited. For example, the plasticizer may be selected from conventional surfactants, ureas, and the like, and sorbitol, ethylene glycol, glycerin, glycerin diacetate and pentaene are considered in consideration of the ease of reaction and storage stability of the starch-based hot melt adhesive described below. It is preferable that it is 1 or more types chosen from the group which consists of rititol, and it is more preferable to select from sorbitol or ethylene glycol. In step (a), the weight ratio of starch to plasticizer is not particularly limited, for example, 1: 0.5 to 1: 3, and more preferably 1: 1 to 1: 2. In addition, the reaction temperature of the step (a) is preferably 80 ~ 120 ℃, more preferably 90 ~ 110 ℃, but is not limited thereto.

In the step (b) of the method for preparing a starch-thermoplastic polymer copolymer according to the present invention, the thermoplastic polymer (especially the end of the thermoplastic polymer) is bonded to the unsaturated carboxylic acid at the ethylenically unsaturated bond position of the unsaturated carboxylic acid bonded to the starch. The chemical bonds form the starch-thermoplastic polymer copolymer. In this case, in the step (b), the wax is used together with the thermoplastic polymer in view of simplifying the starch-based hot melt adhesive manufacturing process to be described later. The wax functions to improve the flowability or increase the thermal stability of the starch-based hot melt adhesive, and the type thereof is not particularly limited. For example, the wax may be one or more selected from the group consisting of paraffin wax, microcrystalline wax, polyethylene wax, polypropylene wax, amide wax and Fischer-Tropsch wax. Fischer-Tropsch wax may also be classified as paraffin wax. Commercial products of paraffin waxes usable in the present invention include Okerin 236 TP sold by Astor Wax Corporation (Doraville, GA); Penreco 4913 available from Pennzoil Products Co. (Houston, TX); R-7152 paraffin wax available from Moore & Munger (Shelton, Connecticut); Paraffin wax 1297 available from International Waxes, Ltd., Ontario, Canada; Pacemaker, available from Citgo; And R-2540 sold by Moore and Munger; And other paraffin waxes such as 1230, 1236, 1240, 1245, 1246, 1255, 1260, and 1262 which are commercially available paraffin waxes at CP Hall, but are not limited thereto. The microcrystalline wax comprises at least 50% by weight of cyclic alkanes or branched alkanes containing chains having 30 to 100 carbon atoms. Microcrystalline waxes are generally less crystalline than paraffin waxes and polyethylene waxes and have a melting point higher than about 70 ° C. Commercial products of microcrystalline waxes usable in the present invention include Victory Amber Wax, commercially available from Petrolite Corp. (Tulsa, Oklahoma) with a melting point of 70 ° C; Bareco ES-796 with a melting point of 70 ° C. and commercially available from Bareco (Chicago, Illinois, USA); Okerin 177, commercially available from Astor Wax Corp., with a melting point of 80 ° C .; Besquare 175 and 195 Amber Waxes, available from Petrolite Corp. (Tulsa, Oklahoma), with melting points of 80 ° C. and 90 ° C .; Indramic 91, commercially available from Industrial Raw Materials (Smesport, PA); Petrowax 9508 Light, which has a melting point of 90 ° C. and is commercially available from Petrowax PA, Inc. (New York, NY), but is not limited thereto. In addition, commercial products of the polyethylene wax usable in the present invention include, but are not limited to, Polywax 500, Polywax 1500 and Polywax 2000 sold by Petrolite, Inc. (Tulsa, Oklahoma, USA). In addition, the amide wax that can be used in the present invention may be selected from the compound represented by the following formula (1).

[Formula 1]

(In Formula 1, R ₁ is an alkanediyl group having 2 to 4 carbon atoms, R ₂ is a hydrocarbon group having 15 to 20 carbon atoms or a hydroxy hydrocarbon group having 15 to 20 carbon atoms, R ₃ and R ₄ is independent of each other and is hydrogen or a hydrocarbon group having 1 to 3 carbon atoms)

In the present invention, a hydrocarbon group is a concept including an alkyl group, an alkenyl group, and an aryl group as a functional group composed of carbon and hydrogen. Compound represented by the formula (1) is oleic acid (Oleic acid), linoleic acid (Linoleic acid), arachidonic acid (Arachidonic acid), palmitic acid (Palmitic acid), stearic acid (Stearic acid), such as fatty acids or hydroxy fatty acid and ethylene Two amide bonds are formed by the reaction of diamines such as diethylene, 1,4-diaminobutane, 1,3-diaminopropane, and the like. As formed, it generally has a high melting point of about 135 ° C to 165 ° C. In Formula 1, R ₂ is a hydrocarbon group such as an alkyl group, an alkenyl group, an aryl group or a hydroxy hydrocarbon group thereof, preferably an alkyl group or a hydroxyalkyl group. In addition, in Formula 1, R ₃ and R ₄ are preferably hydrogen or a methyl group. Specific examples of the compound represented by Formula 1 include 1,2-ethylenebis (stearamide) [1,2-Ethylenebis (stearamide); CAS No. 110-30-5], 1,2-ethylenebis (hydroxystearamide) [1,2-Ethylenebis (hydroxystearamide); CAS Registry No. 38162-95-7 or 123-26-2] and 1,3-propylenebis (palmitamide) [1,3-Propylenebis (palmitamide); CAS No. 54535-68-1], N-N'-ethane-1,2-diylbis (N-ethylstearamid) [N, N'-ethane-1,2-diylbis (N-ethylstearamide) ; CAS No. 262-923-7].

In addition, the Fischer-Tropsch wax is a synthetic wax manufactured by the Fischer-Tropsch method, which is commercially available from Sasol's Sasolwax® product (for example, Sasolwax® H1). , Paraflint® products, or Baker Petolite's Polywax® products (eg Polywax® C80).

In step (b), the weight ratio of the thermoplastic polymer to the wax is not particularly limited, for example, 1: 0.5 to 1: 2, and more preferably 1: 0.5 to 1: 1.

In addition, in the step (b) of the method for preparing a starch-thermoplastic polymer copolymer according to the present invention, a radical reaction initiator is used to induce the reaction between the unsaturated carboxylic acid and the thermoplastic polymer. The radical reaction initiator may be organic peroxide, an azo compound (for example, 2,2-azobisbutyronitrile, 2,2'-azobis-2-methylbutyronitrile, etc.), sodium persulfate, If the type is conventionally used for radical reactions, such as potassium persulfate, the kind is not particularly limited, and considering the reactivity between the unsaturated carboxylic acid and the thermoplastic polymer, it is preferable that the organic peroxide (Organic Peroxide). The organic peroxide is benzoyl peroxide, acetyl peroxide, dilauryl peroxide, di-tert-butyl peroxide, cumyl Cumyl hydroperoxide, di-t-butyl hydroperoxide, dibenzoyl peroxide, succinic peroxide, dilauryl peroxide , Didecanoyl peroxide, dicumyl peroxide, 2,5-dimethyl-2,5-di (tert-butyperoxy) hexane [2,5-dimethyl-2,5- di- (t-butylperoxy) hexane], α-cumyl peroxy-neodecanoate, 1,1-dimethyl-3-hydroxybutyl peroxy-2-ethylhexanoate (1-1-dimethyl-3-hydroxybutyl peroxy-2-ethyl hexanoate), t-amyl peroxy-benzoate, tert-butyl peroxypi T-butyl peroxy-pivalate, 2,5-dihydroxyperoxy-2,5-dimethylhexane, cumene hydroperoxide, and the like. It may be one or more, but is not necessarily limited thereto. Although the amount of the radical reaction initiator used in step (b) is not particularly limited, considering that the degree of reaction between the unsaturated carboxylic acid and the thermoplastic polymer is related to the storage stability of the starch-based hot melt adhesive described later, 100 parts by weight of the thermoplastic polymer It is preferable that it is 0.1-1 weight part per sugar, It is more preferable that it is 0.2-0.8 weight part, It is most preferable that it is 0.3-0.6 weight part.

In addition, the reaction temperature of the step (b) is preferably 110 ~ 150 ℃, considering the color of the starch-based hot melt adhesive to be described later is more preferably 115 ~ 145 ℃, but is not limited thereto. For example, when the ethylene-vinylacetate copolymer is used as the thermoplastic polymer, if the reaction temperature of step (b) exceeds 130 ° C., the color of the starch-based hot melt adhesive may be stronger, thereby limiting the application range. In addition, when the ethylene-alpha octene copolymer is used as the thermoplastic polymer, when the reaction temperature of the step (b) exceeds 140 ° C., the color of the starch-based hot melt adhesive may be strengthened, thereby limiting the application range.

Starch-based hot melt adhesive and method for preparing same

Another aspect of the present invention relates to a starch-based hot melt adhesive with improved storage stability and a method for preparing the same.

The starch-based hot melt adhesive according to the present invention is in the form of a composition comprising a copolymer of starch and a thermoplastic polymer, a plasticizer, a wax and a tackifier. Starch, unsaturated carboxylic acid, thermoplastic polymer, plasticizer and wax in the starch-based hot melt adhesive according to the present invention will be omitted the same parts as described above, and only the newly added parts will be described.

In the starch-based hot melt adhesive according to the present invention, the content of the copolymer of the starch and the thermoplastic polymer is not particularly limited, but it is preferably 15 to 50% by weight based on the total weight of the composition in consideration of harmony with other components. It is more preferable that it is 20 to 45 weight%, and it is most preferable that it is 25 to 40 weight%. In addition, the content of the plasticizer is not particularly limited, but considering the coordination with other components is preferably 30 to 50 parts by weight, more preferably 35 to 45 parts by weight relative to 100 parts by weight of the copolymer of the starch and the thermoplastic polymer. . In addition, the content of the wax is not particularly limited, but considering the coordination with other components, it is preferably 45 to 70 parts by weight, more preferably 50 to 65 parts by weight based on 100 parts by weight of the copolymer of starch and the thermoplastic polymer. .

In addition, in the starch-based hot melt adhesive according to the present invention, the tackifier (Tackifier) is a low molecular weight resin, and when used in combination with a copolymer of a starch and a thermoplastic polymer, which is a basic component, lowers the melt viscosity to improve workability. In some cases, functional groups may be imparted to improve adhesion initial wettability and adhesion on the surface of the adherend of the starch-based hot melt adhesive, and to control the solidification time and the like. In the starch-based hot melt adhesive according to the present invention, the tackifier is not particularly limited to rosin-based resins, terpene resins, coumarone indene resins, petroleum resins, and the like. Examples of rosin-based resins include gum rosin, wood rosin, tall oil rosin, distilled rosin, hydrogenated rosin, dimerized rosin Natural or modified rosins, including resinates, polymerized rosin, and the like; Natural rosin and modified rosin, including fail rosin, glycerol ester of wood rosin, glycerol ester of hydrogenated rosin, glycerol ester of polymerized rosin, pentaerythritol ester of hydrogenated rosin, phenol-modified pentaerythritol ester of rosin Glycerol esters and pentaerythritol esters. Commercial products of the rosin-based resins include Komotac KF382S, Komotac KF392S, Komotac KF452S, Komotac KF462S, Komotac KS-2090, Komotac KS-2100, Komotac KS-2110, Komotac KZ223S, Komotac KZ224S, etc. . In the present invention, the rosin ester is a rosin acid converted to an ester by reacting rosin acid with an alcohol such as methanol, triethylene glycol, pentaerythritol, and including an ester of natural rosin and an ester of modified rosin. Concept. Commercially available rosin esters also include Pinerez 2130, Pinerez 2220, Pinerez 2240, Pinerez 2330, Pinerez 2385 from Akzo Nobel-Eka Chemicals; Ester Gum 105, Ester Gum 106, Ester Gum A, Ester Gum AAL, Ester Gum AAV from Arakawa Chemical; Aquatac E 5375, Aquatac E 6180, Sylvalite RE 10L, Sylvalite RE 80 HP, Sylvalite RE 85L from Arizona Chemical; Pentalyn 710-M, Permalyn 2085, TACOLYN 3100, TACOLYN 3179 H from Eastman Chemical Company. When the rosin ester is used as a tackifier in the present invention, the melt viscosity of the hot melt adhesive and the adhesion time represented by the set time may be maintained at an optimal level, thereby improving workability. Further, among the tackifiers used in the present invention, terpene resins include copolymers and terpolymers of natural terpenes including styrene / terpene and alpha methyl styrene / terpene; Polyterpene resins having a softening point of about 70 ° C. to 150 ° C. measured in accordance with ASTM method E28-58T; Phenol-modified terpene resins and hydrogenated derivatives thereof, including resin products produced by the condensation reaction of bicyclic terpenes with phenols in acidic media. In addition, among the tackifiers used in the present invention, petroleum resins include aliphatic hydrocarbon resins, cycloaliphatic hydrocarbon resins, aromatic hydrocarbon resins, and aliphatic hydrocarbons modified by aromatics. Resins (Aromatic modified aliphatic hydrocarbon resin), and Hydrogenated hydrocarbon resin (Hydrogenated hydrocarbon resin). Commercial products of aliphatic hydrocarbon resins include Hikorez A-1100, Hikorez A-1100S, Hikorez C-1100, Hikorez R-1100 and Hikorez R-1100S from Kolon Oil Corporation. In addition, the alicyclic hydrocarbon resin includes a hydrocarbon resin including dicyclopentadiene (DCPD) as a monomer, and is disclosed in Korean Unexamined Patent Publication No. 1998-013719, Korean Unexamined Patent Publication No. 2008-0093733, and the like. Commercial products of aromatic hydrocarbon resins include Hikotack P-110S, Hikotack P-120, Hikotack P-120HS, Hikotack P-120S, Hikotack P-140, Hikotack P- 140M, Hikotack P-150, Hikotack P-160, Hikotack P-90, Hikotack P-90S, Hirenol PL-1000, Hirenol PL-400. In addition, commercial products of aromatic modified aliphatic hydrocarbon resins include Hikorez T-1080 and Hikorez T-1100 by Kolon Oil Corporation (South Korea). Hydrogenated hydrocarbon resins can also be subdivided into hydrogenated aliphatic hydrocarbon resins and hydrogenated aromatic hydrocarbon resins. Commercial products include Sukorez D-300 and Sukorez D-390 from Kolon Oil Corporation. , Sukorez SU-100, Sukorez SU-110, Sukorez SU-120, Sukorez SU-130, Sukorez SU-90, Hikorez H-2100, Hikorez H-2130, Hikorez H-2200, Hikorez H-2300. In addition, the tackifier used in the present invention may include a hydrocarbon resin having 4 to 10 carbon atoms of the monomer, and specifically include C5 aliphatic resin, C9 aromatic resin, C5 / C9 aliphatic / aromatic copolymer resin, and the like. In addition, the tackifier used in the present invention may include a hydrogenated hydrocarbon resin containing dicyclopentadiene (DCPD) as a monomer, a commercial product of Sukorez D-300, Sukorez of Kolon Oil Corporation (Korea) D-390, Sukorez SU-100, Sukorez SU-110, Sukorez SU-120, Sukorez SU-130, Sukorez SU-90, and the like. Although the content of the tackifier is not particularly limited, it is preferably 100 to 200 parts by weight, more preferably 125 to 175 parts by weight based on 100 parts by weight of the copolymer of the starch and the thermoplastic polymer in consideration of harmony with other components. .

In addition, the starch-based hot melt adhesive according to the present invention may further include an auxiliary additive in addition to the copolymer, plasticizer, wax and tackifier of starch and thermoplastic polymer, the auxiliary additive may change the physical properties of the hot melt adhesive or to the hot melt adhesive Give a specific function. The auxiliary additive included in the starch-based hot melt adhesive according to the present invention may be at least one selected from the group consisting of polybutene, oil, filler, and antioxidant. Polybutene is added to improve water resistance or to impart flexibility. The oil is added to give flexibility, to improve processes such as melt kneading. Filler is a substance applied for the purpose of anti-aging, reinforcement and increase in the practical use of rubber or plastic, and is used to control the flowability of hot melt adhesive. The type of filler is not particularly limited and may be selected, for example, from calcium carbonate, clay, bentonite, or calcium stearate. Antioxidant may be added when using a material containing a structure that can be easily oxidized due to poor thermal stability can improve the change in viscosity, yellowing phenomenon, reduced adhesion and durability degradation due to oxidation and decomposition. The type of antioxidant is not particularly limited, and examples thereof include phenols, aromatic amines, citric acid, or ascorbic acid. In the starch-based hot melt adhesive according to the present invention, the content of the auxiliary additive is preferably 0.01 to 2 parts by weight, more preferably 0.1 to 1 parts by weight based on 100 parts by weight of the copolymer of the starch and the thermoplastic polymer.

The method for preparing a starch-based hot melt adhesive according to the present invention comprises the steps of: (a) reacting starch with an unsaturated carboxylic acid or anhydride thereof in the presence of a plasticizer to form a first composition comprising starch bonded with unsaturated carboxylic acid; (b) adding a wax and a thermoplastic polymer to the first composition and reacting the unsaturated carboxylic acid bonded to the starch and the thermoplastic polymer in the presence of a radical reaction initiator to form a second composition comprising a graft copolymer of starch and the thermoplastic polymer. Forming; And (c) adding and mixing a tackifier to the second composition to form a third composition. The method for preparing a starch-based hot melt adhesive according to the present invention is referred to the above-mentioned contents in the copolymer of starch and the thermoplastic polymer and a method for preparing the same or a starch-based hot melt adhesive.

Hereinafter, the present invention will be described in more detail with reference to Examples. However, the following examples are only intended to clearly illustrate the technical features of the present invention and do not limit the protection scope of the present invention.

1. 분석방법의 설명1. Description of Analysis Method

(1) Melt viscosity

The melt viscosity of the hot melt adhesive was measured using a viscometer (model name: HBDV-ll + P) equipped with a Brookfield Thermosel system. Specifically, 13 ml of the hot melt adhesive was quantitatively placed in the sample chamber and completely melted at about 140 ° C., and the melt viscosity was measured using an SC4-28 spindle.

(2) softening point

The softening point was measured by the ring and ball method specified in KS M 2250.

(3) Set time

After applying a certain amount of hot melt adhesive melted to a paper-based adherend cut to a size of 40 mm × 40 mm, applying a predetermined pressure to measure the time until the adhesion is completed, set time It was made.

2. 전분과 열가소성 폴리머의 공중합체 및 이를 포함하는 전분계 핫멜트 접착제의 제조2. Preparation of Copolymer of Starch and Thermoplastic Polymer and Starch-based Hot Melt Adhesive Comprising the Same

Preparation Example 1.

11.52 parts by weight of D-sorbitol, a plasticizer, was added to the reactor, and the temperature of the reactor was raised to 100 ° C to melt the plasticizer. Thereafter, 0.5 parts by weight of maleic anhydride as a reactive monomer was added to the reactor while maintaining the temperature of the reactor at 100 ° C., and mixed with a plasticizer. Subsequently, 7.94 parts by weight of acid-treated corn starch (viscosity at 50 ° C. of 30 wt% of 4 wt% gelatin liquid: 30-50 cPs; manufacturer: Daesang Co., Korea) was added to the reactor while maintaining the temperature of the reactor at 100 ° C. The reaction was carried out for 50 minutes to obtain a first composition containing modified starch in which the hydroxyl group of starch was substituted with maleic acid. Thereafter, the reactor was a thermoplastic polymer as an ethylene-vinylacetate copolymer [Ehtylene Vinyl Acetate Copolymer, EVA; Product name: VA910 (VA content 28%); Manufacturer: Honam Petrochemical, South Korea) 20.95 parts by weight of polyethylene wax and 8.65 parts by weight of wax and Fischer-Tropsch wax (Product name: Sasolwax H1; Manufacturer: Sasol wax, South Africa) Mix with 1 composition. Thereafter, the temperature of the reactor was raised to 120 ° C., and 2,5-dimethyl-2,5-di (tert-butylperoxy) hexane [2,5-Dimethyl-2,5-di ( tert-butylperoxy) hexane] starch-thermoplastic polymer graft in which 0.07 parts by weight was added and reacted for about 90 minutes to form starch-grafted ethylene-vinylacetate copolymer through maleic acid (or maleic anhydride). A second composition comprising a copolymer was obtained. Then, 20.85 parts by weight of a rosin ester (product name: Pinerez 2130; supplier: Akzo Nobel-Eka chemicals), a tackifier in the reactor, 17.86 parts by weight of a hydrocarbon resin (product name: Piccotac ™ P1095; manufacturer: Eastman Chemical Co.) 4.29 parts by weight of a hydrocarbon resin of a C5 monomer modified with C9 aromatic hydrocarbons (product name: Wingtack® ET; manufacturer: Cray Valley) was added and mixed, and then 0.23 parts by weight of antioxidant was added and mixed to the starch-based hot melt adhesive in the form of a composition. Was prepared.

Figure 2 is a photograph of the starch-based hot melt adhesive prepared in Preparation Example 1. As shown in Figure 1 it can be seen that the starch-based hot melt adhesive prepared in Preparation Example 1 has good compatibility between the components.

Preparation Example 2.

The starch system was prepared in the same manner as in Preparation Example 1, except that the reaction temperature was changed to 130 ° C instead of 120 ° C when the ethylene-vinylacetate copolymer was grafted to the modified starch substituted with maleic acid. Hot melt adhesives were prepared.

Preparation Example 3.

A starch-based hot melt adhesive was prepared in the same manner and conditions as in Preparation Example 1 except that the amount of the maleic anhydride reactive monomer was changed to 0.45 part by weight instead of 0.5 part by weight.

Preparation Example 4.

Dicumyl fur instead of 0.07 parts by weight of 2,5-dimethyl-2,5-di (tert-butylperoxy) hexane [2,5-Dimethyl-2,5-di (tert-butylperoxy) hexane] as a radical reaction initiator A starch-based hot melt adhesive was prepared in the same manner and conditions as in Preparation Example 1, except that 0.11 part by weight of oxide (dicumyl peroxide) was used.

Preparation Example 5.

11.46 parts by weight of D-sorbitol, a plasticizer, was added to the reactor, and the temperature of the reactor was raised to 100 ° C to melt the plasticizer. Thereafter, 0.5 parts by weight of maleic anhydride as a reactive monomer was added to the reactor while maintaining the temperature of the reactor at 100 ° C., and mixed with a plasticizer. Subsequently, 8.44 parts by weight of acid-treated corn starch (viscosity at 50 ° C of 30% by weight of 4 wt% gelatin liquid: 30-50 cPs; manufacturer: Daesang, Korea) was added to the reactor while maintaining the temperature of the reactor at 100 ° C. The reaction was carried out for 50 minutes to obtain a first composition containing modified starch in which the hydroxyl group of starch was substituted with maleic acid. Thereafter, in the reactor, an ethylene-alpha octene copolymer (Ethylene / 1-octene coplymer; product name: Affinity GA 1900; manufacturer: Dow chemical) polymerized by a methanelocene catalyst as a thermoplastic polymer and 17.8 parts by weight of polyethylene wax as wax Part was added and mixed with the first composition. Thereafter, the temperature of the reactor was raised to 135 ° C., and 2,5-dimethyl-2,5-di (tert-butylperoxy) hexane [2,5-Dimethyl-2,5-di ( tert-butylperoxy) hexane] starch-thermoplastic polymer graft in which 0.07 parts by weight of the reaction was carried out and reacted for about 90 minutes to form starch-grafted ethylene-alpha octene copolymer through maleic acid (or maleic anhydride). A second composition comprising a copolymer was obtained. Thereafter, 43 parts by weight of a hydrogenated hydrocarbon resin (product name: Hikorez H-2100; supplier: Kolon Emulsification, Korea), which is a tackifier, was added to the reactor and mixed, and then 0.23 parts by weight of antioxidant was added thereto, followed by mixing. A hot melt adhesive was prepared.

Preparation Example 6.

The starch system was prepared in the same manner as in Preparation Example 5 except that the reaction temperature was changed to 140 ° C instead of 135 ° C when the ethylene-alpha octene copolymer was grafted to the modified starch substituted with maleic acid. Hot melt adhesives were prepared.

Preparation Example 7.

The starch system was prepared in the same manner as in Preparation Example 5 except that the reaction temperature was changed to 150 ° C instead of 135 ° C when the ethylene-alpha octene copolymer was grafted to the modified starch substituted with maleic acid. Hot melt adhesives were prepared.

Comparative Production Example 1.

11.52 parts by weight of D-sorbitol, a plasticizer, was added to the reactor, and the temperature of the reactor was raised to 100 ° C to melt the plasticizer. Subsequently, 7.94 parts by weight of acid-treated corn starch (viscosity at 50 ° C of 30% by weight of 4 wt% gelatinous liquid: 30-50 cPs; manufacturer: Daesang, Korea) was added to the reactor while maintaining the temperature of the reactor at 100 ° C. Mixed with to give the first composition. Thereafter, the reactor was a thermoplastic polymer as an ethylene-vinylacetate copolymer [Ehtylene Vinyl Acetate Copolymer, EVA; Product name: VA910 (VA content 28%); Manufacturer: Honam Petrochemical, South Korea) 20.95 parts by weight of polyethylene wax and 8.65 parts by weight of wax and Fischer-Tropsch wax (Product name: Sasolwax H1; Manufacturer: Sasol wax, South Africa) Mix with 1 composition. Thereafter, the temperature of the reactor was raised to 120 ° C., and 2,5-dimethyl-2,5-di (tert-butylperoxy) hexane [2,5-Dimethyl-2,5-di ( tert-butylperoxy) hexane] 0.07 parts by weight and reacted for about 90 minutes to obtain a second composition. Then, 20.85 parts by weight of a rosin ester (product name: Pinerez 2130; supplier: Akzo Nobel-Eka chemicals), a tackifier in the reactor, 17.86 parts by weight of a hydrocarbon resin (product name: Piccotac ™ P1095; manufacturer: Eastman Chemical Co.) 4.29 parts by weight of a hydrocarbon resin of a C5 monomer modified with C9 aromatic hydrocarbons (product name: Wingtack® ET; manufacturer: Cray Valley) was added and mixed, and then 0.23 parts by weight of antioxidant was added and mixed to the starch-based hot melt adhesive in the form of a composition. Was prepared.

Comparative Production Example 2.

11.52 parts by weight of D-sorbitol, a plasticizer, was added to the reactor, and the temperature of the reactor was raised to 100 ° C to melt the plasticizer. Thereafter, 0.5 parts by weight of maleic anhydride as a reactive monomer was added to the reactor while maintaining the temperature of the reactor at 100 ° C., and mixed with a plasticizer. Subsequently, 7.94 parts by weight of acid-treated corn starch (viscosity at 50 ° C. of 30 wt% of 4 wt% gelatin liquid: 30-50 cPs; manufacturer: Daesang Co., Korea) was added to the reactor while maintaining the temperature of the reactor at 100 ° C. The reaction was carried out for 50 minutes to obtain a first composition containing modified starch in which the hydroxyl group of starch was substituted with maleic acid. Thereafter, the reactor was a thermoplastic polymer as an ethylene-vinylacetate copolymer [Ehtylene Vinyl Acetate Copolymer, EVA; Product name: VA910 (VA content 28%); Manufacturer: Honam Petrochemical, South Korea) 20.95 parts by weight of polyethylene wax and 8.65 parts by weight of wax and Fischer-Tropsch wax (Product name: Sasolwax H1; Manufacturer: Sasol wax, South Africa) Mixing with one composition gave a second composition. Then, 20.85 parts by weight of a rosin ester (product name: Pinerez 2130; supplier: Akzo Nobel-Eka chemicals), a tackifier in the reactor, 17.86 parts by weight of a hydrocarbon resin (product name: Piccotac ™ P1095; manufacturer: Eastman Chemical Co.) 4.29 parts by weight of a hydrocarbon resin of a C5 monomer modified with C9 aromatic hydrocarbons (product name: Wingtack® ET; manufacturer: Cray Valley) was added and mixed, and then 0.23 parts by weight of antioxidant was added and mixed to the starch-based hot melt adhesive in the form of a composition. Was prepared.

Comparative Production Example 3

11.46 parts by weight of D-sorbitol, a plasticizer, was added to the reactor, and the temperature of the reactor was raised to 100 ° C to melt the plasticizer. Subsequently, 8.44 parts by weight of acid-treated corn starch (viscosity at 50 ° C of 30% by weight of 4 wt% gelatin liquid: 30-50 cPs; manufacturer: Daesang Co., Korea) was added to the reactor while maintaining the temperature of the reactor at 100 ° C. Mixed with to give the first composition. Thereafter, in the reactor, an ethylene-alpha octene copolymer (Ethylene / 1-octene coplymer; product name: Affinity GA 1900; manufacturer: Dow chemical) polymerized by a methanelocene catalyst as a thermoplastic polymer and 17.8 parts by weight of polyethylene wax as wax Part was added and mixed with the first composition. Thereafter, the temperature of the reactor was raised to 135 ° C., and 2,5-dimethyl-2,5-di (tert-butylperoxy) hexane [2,5-Dimethyl-2,5-di ( tert-butylperoxy) hexane] 0.07 parts by weight and reacted for about 90 minutes to obtain a second composition. Thereafter, 43 parts by weight of a hydrogenated hydrocarbon resin (product name: Hikorez H-2100; supplier: Kolon Emulsification, Korea), which is a tackifier, was added to the reactor and mixed, and then 0.23 parts by weight of antioxidant was added thereto, followed by mixing. A hot melt adhesive was prepared.

Comparative Production Example 4.

29.85 parts by weight of ordinary corn starch, 2.99 parts by weight of sorbitan fatty acid ester as a plasticizer (product name: Almax 2070; supplier: Ilsin Wells, Korea) and 0.5 parts by weight of urea, ethylene-vinylacetate copolymer as thermoplastic polymer (Ehtylene Vinyl Acetate Copolymer, EVA; CAS No. 24937-78-8) 19.90 parts by weight, rosin ester as a tackifier (Product name: Pinerez 2130; Supplier: Akzo Nobel-Eka chemicals) 34.83 parts by weight, Paraffin wax by wax (Product name: Okerin 236 TP; supplier: Astor Wax Corporation) 9.95 parts by weight and 1.99 parts by weight of polyethylene wax were sequentially added to a kneader (kneader, kneader) preheated to about 170 ~ 180 ℃ and melt kneaded to prepare a starch-based hot melt adhesive.

Figure 3 is a photograph of the starch-based hot melt adhesive prepared in Comparative Preparation Example 4. As shown in FIG. 4, the starch-based hot melt adhesive prepared in Comparative Preparation Example 4 may have poor compatibility between components, and a part of starch may be present in the form of particles.

3. 핫멜트 접착제의 물성 평가3. Evaluation of Properties of Hot Melt Adhesive

(1) Evaluation of Storage Stability of Hot Melt Adhesives

After the starch-based hot melt adhesive prepared in Preparation Examples 1 to 7 and Comparative Preparation Examples 1 to 3 was melted at 140 ° C., the initial viscosity was measured, and stored at 140 ° C. for 24 hours, and then generation of a precipitate. Phase separability was evaluated through whether or not, and viscosity stability was evaluated through viscosity change.

Phase segregation was assessed as "bad" if a precipitate occurred, and "good" if no sediment occurred. In addition, the viscosity stability was evaluated as "good" when it can be regarded as a measurement error range by changing to less than 50 cPs when "500 cPs or more reduced than the initial viscosity, and the results are shown in Table 1 below. .

Table 1

Hot melt adhesive	Initial viscosity (cPs, at 140 ° C)	Storage stability (after 1 day, at 140 ° C)
Hot melt adhesive	Initial viscosity (cPs, at 140 ° C)	Phase separation	Viscosity stability
Preparation Example 1	1,920	Good	Good
Preparation Example 2	1,930	Good	Good
Preparation Example 3	1,840	Good	Good
Preparation Example 4	1,920	Good	Good
Preparation Example 5	1,680	Good	Good
Preparation Example 6	1,690	Good	Good
Preparation Example 7	1,690	Good	Good
Comparative Production Example 1	4,800	Bad	Bad
Comparative Production Example 2	1,920	Bad	Bad
Comparative Production Example 3	4,300	Bad	Bad

In the case of the hot melt adhesive prepared in Preparation Examples 1 to 7, there was no precipitate even after melting at 140 ° C. for 24 hours, and there was no change in viscosity or very low level. On the other hand, in the case of the hot melt adhesive prepared in Comparative Preparation Examples 1 to 3, a large amount of precipitates occurred after melting at 140 ° C. and stored for 24 hours, and the viscosity also decreased by more than 500 cPs compared with the initial stage. Hot melt adhesive prepared in 1 was reduced by more than 800 cPs.

(2) Comparison of Properties with Commercial Hot Melt Adhesives

Melt viscosity, softening point, and set time at 140 ° C. of the hot melt adhesive prepared in Preparation Example 1 and the commercially available non-star type hot melt adhesive were measured, and the results are shown in Table 2 below.

TABLE 2

Hot melt adhesive	Melting Viscosity (cPs, at 140 ℃)	Softening point (℃)	Fixed time
Preparation Example 1	1,920	110	Less than 3 seconds
Domestic M Company Products	1,870	114	Less than 3 seconds
Overseas H company product	19,50	103	Less than 3 seconds

Starch-based hot melt adhesive according to the present invention exhibited the same physical properties as commercial non-starch hot melt adhesive.

Although the present invention has been described through the above embodiments as described above, the present invention is not necessarily limited thereto, and various modifications can be made without departing from the scope and spirit of the present invention. Therefore, the protection scope of the present invention should not be limited to the specific embodiments, but should be construed as including all embodiments falling within the scope of the claims appended to the present invention.

Claims

A graft copolymer of starch and a thermoplastic polymer, wherein the graft copolymerization of the starch and the thermoplastic polymer is formed via an unsaturated carboxylic acid.
The copolymer of starch and a thermoplastic polymer according to claim 1, wherein the starch is a modified starch whose polymerization degree is reduced by acid treatment or enzyme treatment.
The method of claim 1, wherein the thermoplastic polymer is an ethylene-vinyl acetate copolymer (Ehtylene Vinyl Acetate Copolymer, EVA), polyvinyl acetate (Polyvinyl acetate), polyvinyl alcohol, ethylene- acrylic acid copolymer, ethylene-meth A copolymer of a starch and a thermoplastic polymer, characterized in that it is at least one member selected from the group consisting of a acrylic acid copolymer, an ethylene-butyl acrylate copolymer, an ethylene-ethylhexyl acrylate copolymer, and an ethylene-methyl acrylate copolymer.
The copolymer of starch and thermoplastic polymer according to claim 1, wherein the thermoplastic polymer is a thermoplastic polyolefin.
The copolymer of starch and thermoplastic polymer according to claim 4, wherein the thermoplastic polyolefin is an ethylene-alpha olefin copolymer or a propylene-alpha olefin copolymer.
The copolymer of starch and thermoplastic polymer according to claim 1, wherein the weight ratio of starch to thermoplastic polymer is from 0.5: 1 to 1: 5.
The copolymer of starch and thermoplastic polymer according to claim 1, wherein the unsaturated carboxylic acid is unsaturated dicarboxylic acid.
According to claim 7, The unsaturated dicarboxylic acid is maleic acid (Maleic acid), Fumaric acid (Fumaric acid), Glutaconic acid (Glutaconic acid, anhydride), Traumatic acid (Traumatic acid), Muconic acid (Muconic acid), Citraconic acid (Citraconic acid) and copolymers of starch and thermoplastic polymers, characterized in that at least one selected from the group consisting of these.
8. The copolymer of starch and thermoplastic polymer according to claim 7, wherein the weight ratio of starch to unsaturated dicarboxylic acid is from 1: 0.01 to 1: 0.2.
(a) reacting starch with unsaturated carboxylic acid in the presence of a plasticizer to form a first composition comprising starch to which unsaturated carboxylic acid is bound; And

(b) adding a wax and a thermoplastic polymer to the first composition and reacting the unsaturated carboxylic acid bonded to the starch and the thermoplastic polymer in the presence of a radical reaction initiator to form a second composition comprising a graft copolymer of starch and the thermoplastic polymer. Method for producing a copolymer of the starch and thermoplastic polymer comprising the step of.
The method according to claim 10, wherein the plasticizer is a sorbitol, ethylene glycol, glycerin, glycerin diacetate (glycerin diacetate) and pentaerythritol to prepare a copolymer of starch and thermoplastic polymer, characterized in that at least one member selected from the group consisting of. How to.
11. The wax of claim 10, wherein the wax is at least one selected from the group consisting of paraffin wax, microcrystalline wax, polyethylene wax, polypropylene wax, amide wax and Fischer-Tropsch wax. Method for producing a copolymer of starch and thermoplastic polymer, characterized in that.
The method of claim 10, wherein the radical reaction initiator is an organic peroxide.
The method of claim 10, wherein the reaction temperature of the step (a) is 80 ~ 120 ℃, the reaction temperature of the step (b) is a method for producing a copolymer of the starch and thermoplastic polymer, characterized in that 110 ~ 150 ℃.
A starch-based hot melt adhesive in the form of a composition comprising a copolymer of a starch and a thermoplastic polymer, plasticizer, wax and tackifier selected from any one of claims 1 to 9.
The starch-based hot melt adhesive of claim 15, wherein the content of the copolymer of the starch and the thermoplastic polymer is 15 to 50% by weight based on the total weight of the composition.
The starch-based hot melt adhesive of claim 15, wherein the amount of the plasticizer is 30 to 50 parts by weight based on 100 parts by weight of the copolymer of starch and the thermoplastic polymer.
The starch-based hot melt adhesive according to claim 15, wherein the wax content is 45 to 70 parts by weight based on 100 parts by weight of the copolymer of starch and thermoplastic polymer.
The starch-based hot melt adhesive according to claim 15, wherein the content of the tackifier is 100 to 200 parts by weight based on 100 parts by weight of the copolymer of starch and the thermoplastic polymer.
The method of claim 15, wherein the plasticizer is at least one selected from the group consisting of sorbitol, ethylene glycol, glycerin, glycerin diacetate and pentaerythritol, the wax is paraffin wax, microcrystalline wax (microcrystalline wax) waxes, polyethylene waxes, polypropylene waxes, amide waxes and Fischer-Tropsch waxes. The tackifiers are rosin esters and aliphatic hydrocarbon resins. ), Cycloaliphatic hydrocarbon resin, aromatic hydrocarbon resin, aromatic modified aliphatic hydrocarbon resin, and hydrogenated hydrocarbon resin Starch-based hot melt, characterized in that at least one selected glue.