KR101535564B1 - Starch-based polymer particle emulsion for pressure-sensitive adhesive and manufacturing method thereof - Google Patents

Abstract

The present invention provides a sticky water-based emulsion comprising water as the starch-based polymer particles of the core-shell structure in dispersion medium and a dispersion medium. The starch-based polymer particle emulsion according to the present invention can be used as a main component of a pressure-sensitive adhesive or a pressure-sensitive adhesive since it has excellent initial adhesion, peel adhesion strength to an adherend, and re-peelability. Also, since the starch-based polymer particles of the present invention are based on starches which are biomass capable of repeatedly producing indefinitely, they are more environment-friendly than conventional polymer materials based on petroleum raw materials and stable in raw material supply, Can be secured. Therefore, when the starch-based polymer particle emulsion according to the present invention is used, it is possible to produce an environment-friendly pressure sensitive adhesive product such as an adhesive tape, an adhesive film, an adhesive label and the like.

Description

TECHNICAL FIELD [0001] The present invention relates to a starch-based polymer particle emulsion for pressure-sensitive adhesives,

The present invention relates to a starch-based polymer particle emulsion and a method for producing the same, and more particularly to a starch-based polymer particle emulsion which is used as a main component of a pressure-sensitive adhesive or a pressure-sensitive adhesive to improve the adhesive property and re- .

The adhesive is defined as an adhesive which can be easily dropped without contaminating the surface of the object to be bonded, unlike the adhesive in a narrow sense, which causes interfacial destruction when both surfaces of the object to be bonded are strongly and permanently bonded and peeled off. adhesive, PSA). Adhesives are used in various fields such as labels, tapes, masking of specific areas, albums, road markings, etc. because of temporary adhesion and re-peeling.

Main properties of the pressure sensitive adhesive include initial tack, peel strength at room temperature, holding force associated with re-peeling property, cohesive force corresponding to resistance at a constant load, and the proper matching of the properties is required. Most of the currently used pressure sensitive adhesives have a problem of discharging volatile organic substances in solvent form. Recently, research on water-based pressure-sensitive adhesives that can replace solvent-based pressure-sensitive adhesives has been continuing due to increased environmental regulations and increased interest in the environment. As water-based pressure-sensitive adhesives, water-based acrylic emulsion pressure-sensitive adhesives are typically used, and water-resistance and heat resistance are lower than solvent-based pressure-sensitive adhesives and adhesive properties are greatly deteriorated due to aging. In addition, since most of the materials used for producing the aqueous acrylic emulsion pressure-sensitive adhesive are derived from petroleum, there is a problem in that they are not environmentally friendly, and there is a problem of supply-demand instability dominated by petroleum raw materials.

In order to solve this problem, attempts have been made to replace some components of the aqueous acrylic emulsion pressure-sensitive adhesive with eco-friendly substances such as starch. For example, Korean Patent Registration No. 10-0940707 discloses an emulsion type starch-acrylic copolymer useful as a base resin of a pressure-sensitive adhesive and a pressure-sensitive adhesive containing the same. However, due to the high glass transition temperature of the starch itself and poor re-peeling properties, there is a limit to using starch or a simple starch-acrylic copolymer as the spot-wearing material.

An object of the present invention is to provide a starch-based polymer particle emulsion for pressure-sensitive adhesives excellent in initial adhesion, peel adhesion strength to an adherend, and re-peelability.

Another object of the present invention is to provide a process for producing the starch-based polymer particle emulsion for a pressure-sensitive adhesive.

Typical re-peelable aqueous acrylic pressure sensitive adhesives include those having an unsaturated carboxylic acid and a hydroxyl group such as hydroxyethyl methacrylate, hydroxypropyl methacrylate, hydroxyethyl acrylate, hydroxypropyl acrylate and hydroxybutyl acrylate (Meth) acrylate. When the conventional re-peelable aqueous acrylic pressure-sensitive adhesive is applied and dried, the carboxyl group of the unsaturated carboxylic acid and the hydroxyl group of the (meth) acrylate having a hydroxyl group internally undergo crosslinking reaction to form a tacky coating film. However, in the case of forming a cohesive coating film by using an internal crosslinking reaction between hydroxyl groups of a carboxyl group of the unsaturated carboxylic acid and (meth) acrylate having a hydroxyl group in an aqueous emulsion containing polymer particles based on starch hydrolyzate, There is a problem that the peel adhesion strength with respect to the adherend and the re-peeling property can not reach a satisfactory level. The present inventors have found that when a starch polymer particle as a dispersoid of an aqueous emulsion is a core-shell structure and a viscous coating film is formed with an aqueous emulsion containing starch-based polymer particles, the hydroxyl groups present in the starch hydrolyzate and the unsaturated carboxylic acid Or when an internal cross-linking reaction between the carboxyl group of the unsaturated carboxylic acid present in the shell and the epoxy group of the unsaturated monomer having an epoxy group present in the shell is used, the initial cohesion of the cohesive coating film, Peel adhesion strength and re-peeling property of the present invention are remarkably improved, and the present invention has been completed.

In order to solve one object of the present invention, the present invention provides an aqueous emulsion comprising water as dispersion medium and starch-based polymer particles as dispersion medium, wherein the starch-based polymer particles are a core and a shell formed by polymerization of a starch- Shell structure comprising a shell formed on the core by polymerization of a monomer mixture, wherein the core monomer mixture contains at least two or more soft monomers having no hydroxyl groups, and the shell monomer mixture has a hardness not having a hydroxyl group Wherein the soft monomer has an ethylenically unsaturated bond and the homopolymer has a glass transition temperature of from 30 캜 to 250 캜, the soft monomer is selected from the group consisting of ethylene And the homopolymer has a glass transition temperature of from < RTI ID = 0.0 > 10 C < / RTI & -80 < [deg.] ≫ C. The present invention also provides a starch-based polymer particle emulsion for a pressure-sensitive adhesive. At this time, the shell monomer mixture may further include an unsaturated monomer having an epoxy group.

In order to solve the other object of the present invention, the present invention provides a method for preparing starch hydrolyzate, which comprises adding and mixing an emulsifier to a starch hydrolyzate containing starch hydrolysates, adding a core monomer mixture and a polymerization initiator thereto, Obtaining an aqueous emulsion comprising a core; And adding a shell monomer mixture and a polymerization initiator to an emulsion containing the core to form a shell on the core, wherein the core monomer mixture contains at least two soft monomers having no hydroxyl groups Wherein the shell monomer mixture comprises a hard monomer having no hydroxyl group, a soft monomer having no hydroxyl group, and an unsaturated carboxylic acid monomer, wherein the hard monomer has an ethylenically unsaturated bond and the glass transition temperature of the homopolymer is from 30 [ Wherein the soft monomer has an ethylenic unsaturated bond and the homopolymer has a glass transition temperature of 10 ° C to -80 ° C. The present invention also provides a process for producing a starch-based polymer particle emulsion for a pressure-sensitive adhesive, . At this time, the shell monomer mixture may further include an unsaturated monomer having an epoxy group.

The starch-based polymer particle emulsion according to the present invention can be used as a main component of a pressure-sensitive adhesive or a pressure-sensitive adhesive since it has excellent initial adhesion, peel adhesion strength to an adherend, and re-peelability. Also, since the starch-based polymer particles of the present invention are based on starches which are biomass capable of repeatedly producing indefinitely, they are more environment-friendly than conventional polymer materials based on petroleum raw materials and stable in raw material supply, Can be secured. Therefore, when the starch-based polymer particle emulsion according to the present invention is used, it is possible to produce an environment-friendly pressure sensitive adhesive product such as an adhesive tape, an adhesive film, an adhesive label and the like.

Hereinafter, the present invention will be described in detail.

One. For adhesive Starch-based  Polymer particles emulsion

One aspect of the present invention relates to a starch-based polymer particle emulsion for a pressure-sensitive adhesive excellent in initial adhesion, peel adhesion strength to an adherend, and re-peelability. The starch-based polymer particle emulsion according to the present invention is an aqueous emulsion containing water as a dispersion medium and starch-based polymer particles having a core-shell structure and water as a dispersion medium. In addition, the starch-based polymer particle emulsion according to the present invention may further comprise an emulsifier or a polymerization initiator added during the production of the starch-based polymer particles.

Starch-based  Polymer particles

In the present invention, the starch-based polymer particles have a core-shell structure including a shell formed on the core by polymerization of a core and shell monomer mixture formed by polymerization of a starch decomposition product and a core monomer mixture.

In the present invention, the core of the starch-based polymer particles is composed of a starch-based copolymer formed by polymerization of a starch decomposition product and a core monomer mixture. At this time, the starch hydrolyzate is obtained by treating starch with enzyme, acid, heat or the like and decomposing it into a state capable of liquefaction in water. The raw starch for obtaining the starch hydrolyzate includes all natural starches derived from plants, physically or chemically modified starches, and the like. The natural starches may be selected from various plant-derived starches (i.e., unmodified starches) including corn, waxy corn, potatoes, sweet potatoes, wheat, rice, tapioca, sago, waxy maize, sorghum, . In addition, the modified starch includes all the starches obtained by reforming the unmodified starch by methods such as etherification, esterification, oxidation, acid treatment, oxidative esterification, oxidative etherification, enzyme treatment and the like. The starch hydrolyzate used for forming the starch-based polymer particles in the present invention preferably has at least one functional group selected from the group consisting of a carboxyl group, a carbonyl group, an aldehyde group and an ester group from the viewpoint of improving the efficiency of the polymerization reaction, The starch hydrolyzate may be prepared by decomposing at least one modified starch selected from the group consisting of oxidized starch, esterified starch, and oxidized esterified starch, or oxidizing, esterifying, or oxidizing the starch hydrolyzate obtained by decomposing unmodified starch Can be manufactured. In addition, the core monomer mixture contains at least two or more different soft monomers having no hydroxyl groups. In the present invention, the soft monomer refers to a monomer containing an ethylenic unsaturated bond such as a vinyl group, an allyl group or an acryl group, and the homopolymer is tacky at room temperature. In the present invention, the soft monomer has such a characteristic, and at the same time, the homopolymer is a monomer having a glass transition temperature of from 10 캜 to -80 캜, preferably from 5 캜 to -60 캜. The type of soft monomer having no hydroxyl group in the present invention is not particularly limited as long as it satisfies the above-mentioned characteristics, and is preferably selected from the group consisting of methyl acrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate, Ethylhexyl acrylate, ethylhexyl acrylate, ethylhexyl methacrylate and lauryl methacrylate. Further, in the present invention, the core monomer mixture may be prepared by copolymerizing methyl acrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate, octyl acrylate, ethylhexyl acrylate, ethylhexyl methacrylate and lauryl methacrylate And a combination of any one selected from n-butyl acrylate and isobutyl acrylate with any one selected from ethylhexyl acrylate and ethylhexyl methacrylate desirable.

In the present invention, the shell of the starch-based polymer particles is composed of a copolymer formed on the core by polymerization of a shell monomer mixture. At this time, the shell monomer mixture includes a hard monomer having no hydroxyl group, a soft monomer having no hydroxyl group, and an unsaturated carboxylic acid monomer, and may further optionally include an unsaturated monomer having an epoxy group. In addition, the shell monomer mixture may optionally further comprise a chain transfer agent. In this event, the soft monomer is mainly used to impart high initial tackiness to the starch-based polymer particle emulsion, and the hard monomer is used to impart high cohesion and adhesion to the starch-based polymer particle emulsion. The soft monomer having no hydroxyl group is the same as that described in the core, and thus the description thereof will be omitted. In the present invention, the term "hard monomer" refers to a monomer containing an ethylenic unsaturated bond such as a vinyl group, an allyl group, or an acrylic group, and the homopolymer is not tacky at room temperature. In the present invention, the light-weight monomer has such a characteristic, and at the same time, the homopolymer is a monomer having a glass transition temperature of 30 ° C to 250 ° C, preferably 40 ° C to 200 ° C. The type of the hard monomer having no hydroxyl group in the present invention is not limited as long as it satisfies the above-mentioned characteristics, and examples thereof include methyl methacrylate, ethyl methacrylate, butyl methacrylate, acrylonitrile, methacrylonitrile , Isobornyl acrylate, isobornyl methacrylate, vinyl toluene, vinyl acetate, and vinyl chloride. In consideration of various properties of the starch-based polymer particle emulsion, methyl methacrylate , And is preferably composed of at least one member selected from the group consisting of methyl methacrylate, butyl methacrylate, acrylonitrile, methacrylonitrile, isobornyl acrylate, and isobornyl methacrylate, Is more preferable. When the hard monomer constituting the shell monomer mixture is methyl methacrylate, the soft monomer constituting the shell monomer mixture is preferably any one selected from n-butyl acrylate and isobutyl acrylate. The unsaturated carboxylic acid monomer in the present invention is not limited in its kind insofar as it has an ethylenic unsaturated bond for polymerization with other monomers, and includes unsaturated carboxylic acids such as acrylic acid, methacrylic acid, itaconic acid, maleic acid and fumaric acid , And more preferably selected from acrylic acid or methacrylic acid. The unsaturated monomer having an epoxy group in the present invention is not limited in its kind insofar as it has an ethylenic unsaturated bond for polymerization with other monomers, and is not limited to glycidyl acrylate, glycidyl methacrylate methacrylate, 1,2-epoxy-9-decene, 1,2-epoxy-5-hexene, (4-vinyl-1-cyclohexene-1,2-epoxide), limonene-1,2-epoxide and allyl glycidyl ether allyl glycidyl ether, and more preferably selected from glycidyl acrylate or glycidyl methacrylate. The term " glycidyl methacrylate " In the present invention, a chain transfer agent is used for controlling the molecular weight of the polymer and is not limited in its kind. Preferably, n-dodecyl mercaptan, t-dodecyl mercaptan, 1,5-pentane Dithiol, 1,6-hexanedithiol, 2-ethylhexyl-3-mercaptopropionate, butyl 3-mercaptopropionate, dodecyl 3-mercaptopropionate, ethyl 2-mercaptopropionate Methyl 3-mercaptopropionate, pentaerythritol tetrakis (3-mercaptopropionate), 2-ethylhexyl mercaptoacetate, ethyl 2-mercaptoacetate, 2-hydroxymethyl-2-methyl-1,3-propanediol, and pentaerythritol tetrakis (2-mercaptoacetate).

The weight ratio between the starch hydrolyzate used to form the starch-based polymer particles of the present invention, the monomers constituting the core monomer mixture and the monomers constituting the shell monomer mixture is not particularly limited, but the weight ratio of the pressure- And may be limited to a specific range in consideration of various physical properties such as physical properties. For example, the weight ratio of the monomers forming the starch hydrolyzate to the starch polymer particles is preferably from 5:95 to 30:70, more preferably from 5:95 to 20:80, even more preferably from 5:95 to 15: 85 < / RTI > Further, the weight ratio of the core monomer mixture to the shell monomer mixture is preferably 5:95 to 30:70, more preferably 10:90 to 30:70, and most preferably 10:90 to 20:80. Also, the weight ratio of the hard monomer to the soft monomer in the shell monomer mixture is preferably from 2:98 to 20:80, more preferably from 2:98 to 15:85, most preferably from 5:95 to 15:85 desirable. The content of the unsaturated carboxylic acid monomer is preferably 0.5 to 20 parts by weight, more preferably 1 to 20 parts by weight, and most preferably 1 to 10 parts by weight per 100 parts by weight of the shell monomer mixture. The content of the unsaturated monomer having an epoxy group is preferably 0.1 to 10 parts by weight, more preferably 0.5 to 5 parts by weight, and most preferably 0.5 to 3 parts by weight per 100 parts by weight of the shell monomer mixture. The content of the chain transfer agent is preferably 0.01 to 1 part by weight, more preferably 0.1 to 1 part by weight, and most preferably 0.1 to 0.8 part by weight per 100 parts by weight of the shell monomer mixture.

Emulsifier

The aqueous emulsion of the starch-based polymer particles according to the present invention preferably comprises an emulsifier. The emulsifier is added in the process of preparing the starch-type polymer particles by emulsion polymerization (or emulsion polymerization), and adsorbed on the surface of the starch-based polymer particles to improve the dispersibility of the starch-based polymer particles. The emulsifier is preferably composed of a combination of an anionic emulsifier and a nonionic emulsifier, and more preferably an anionic emulsifier and a nonionic emulsifier. The reactive emulsifier may be selected from the group consisting of a vinyl group, an allyl group, an acryloyl group, a methacryloyl group, a propenyl group, a vinylidene group, And at least one functional group selected from a vinylene group, minimizes the occurrence of agglomerates during the production of the starch-based polymer particles, and can uniformize the size distribution of the starch-based polymer particles. The anionic reactive emulsifier serves to form micelles in the process of preparing the starch-based polymer particles by emulsion polymerization, and the nonionic emulsifier serves to stabilize the micellar structure.

Examples of the anionic reactive emulsifier usable in the present invention include bis (polyoxyethylene polycyclic phenyl ether) methacrylated sulfonate (bis (polyoxyethylene polycyclic phenyl ether) methacrylated sulfonate; Commercial products include "ANTOX MS-60" from Nippon Nyukazai Co., Ltd., propenyl-alkylsulfosuccinate, (meth) acrylic acid (meth) acrylic acid polyoxyethylene sulfonate; Commercial products include "ELEMINOLRS-30" from Sanyo Chemical Industries, Ltd.], allyloxymethyl alkyloxy polyoxyethylene sulfonate (commercially available from DAI-ICHI KOGYO SEIYAKU CO., LTD. ADEKAREASOAP SR-10 "," ADEKAREASOAP SR-20 "and" ADEKAREASOAP SR-10 "manufactured by Asahi Denka Kogyo KK), allyloxy methylalkoxyethyl polyoxyethylene sulfate 30 "), and polyoxyalkylene alkenyl ether ammonium sulfate (commercially available products include" LATEMUL PD-104 "available from Kao Corp.). Other anionic emulsifiers that can be used in the present invention include "LATEMUL S-120", "LATEMUL S-120A", "LATEMUL S-180" and "LATEMUL S-180A" , "ELEMINOL JS-2 ", and the like; And alkenyl succinate-based anionic emulsifiers such as "LATEMUL ASK " from Kao Corp., and the like. Examples of other anionic emulsifiers which can be used in the present invention include 2-sulfoethyl (meth) acrylate sodium salt, 3-sulfopropyl (meth) acrylate ammonium salt [ (Meth) acrylic acid sulfoalkyl ester salt] such as 3-sulfopropyl (meth) acrylate ammonium salt; Sulfopropylmaleic acid alkyl ester sodium salt, sulfopropylmaleic acid polyoxyethylene alkyl ester ammonium salt, sulfoethylfumaric acid alkyl ester ammonium salt, sulfoethylfumaric acid alkyl ester sodium salt, alkyl ester ammonium salts); alkylsulfosuccinates; Maleic acid dipolyethylene glycol alkylphenol ether sulfate, phthalic acid dihydroxyethyl ester (meth) acrylate sulfate; phthalic acid dihydroxyethyl ester (meth) acrylate sulfate; 1-allyloxy-3-alkyl phenoxy-2-polyoxyethylene sulfate; Commercial products include "ADEKAREASOAP SE-10N" and "ADEKAREASOAP SE-20N" from Asahi Denka Kogyo K.K.); And polyoxyethylene alkylalkenylphenol sulfate (commercially available as "AQUALON" from DAI-ICHI KOGYO SEIYAKU CO., LTD.).

Examples of the nonionic reactive emulsifier that can be used in the present invention include allyloxymethyl alkoxy ethyl hydroxy polyoxyethylene, polyoxyalkylene alkenyl ether, polyoxyethylene alkyl ether (ADEKAREASOAP ER-10, ADEKAREASOAP ER-20, ADEKAREASOAP ER-30) by Asahi Denka Kogyo KK are commercially available products such as polyoxyalkylene alkyl ether and polyoxyalkylene alkyl phenyl ether. ADEKAREASOAP NE-20 "," ADEKAREASOAP NE-30 "," ADEKAREASOAP NE-40 "," ADEKAREASOAP RN-20 "; "LATEMULPD-420 "," LATEMULPD-430 " And "AQUALON RS-20" of DAI-ICHI KOGYO SEIYAKU CO., LTD.).

The content of the emulsifier in the starch-based polymer particle emulsion according to the present invention is not particularly limited and is preferably 0.5 to 10 parts by weight, more preferably 1 to 10 parts by weight, more preferably 2 to 10 parts by weight, Most preferably 6 parts by weight. When the emulsifier is composed of a combination of an anionic emulsifier and a nonionic emulsifier, the weight ratio of the anionic emulsifier to the nonionic emulsifier is preferably 1: 0.1 to 1: 1, more preferably 1: 0.2 to 1: 0.8.

water

The starch-based polymer particle emulsion according to the present invention comprises water as a dispersion medium. The content of the solid content in the starch-based polymer particle emulsion according to the present invention is not particularly limited, and is usually 35 to 60% by weight when the starch-based polymer particles are prepared by emulsion polymerization. The viscosity of the starch-based polymer particle emulsion according to the present invention is in the range of 500 to 700 centipoise (cPs), preferably 550 to 650 centipoise (cPs).

Polymerization initiator

The starch-based polymer particle emulsion according to the present invention may further comprise a small amount of a polymerization initiator used in preparing the starch-based polymer particles. The content of the polymerization initiator is 0.05 to 2 parts by weight, preferably 0.1 to 1 part by weight, based on 100 parts by weight of the starch-based polymer particles.

2. For adhesive Starch-based  Polymer particles Emulsion  Manufacturing method

Another aspect of the present invention relates to a method for producing a starch-based polymer particle emulsion for a pressure-sensitive adhesive excellent in initial adhesion, peel adhesion strength to an adherend, and re-peelability. The method for producing the starch-based polymer particle emulsion according to the present invention includes all of the above-mentioned contents in the starch-based polymer particle emulsion, and redundant description is omitted as much as possible. The method for producing a starch-based polymer particle emulsion for a pressure sensitive adhesive according to the present invention is characterized in that an emulsifier is added to and mixed with a starch hydrolyzate containing a starch hydrolyzate and then a core monomer mixture and a polymerization initiator are added thereto, To obtain an aqueous emulsion comprising a core comprising: And adding a shell monomer mixture and a polymerization initiator to the emulsion containing the core and polymerizing to form a shell on the core. Wherein the core monomer mixture comprises at least two soft monomers having no hydroxyl groups and the shell monomer mixture comprises a hard monomer having no hydroxyl group, a soft monomer having no hydroxyl group, and an unsaturated carboxylic acid monomer, Wherein the hard monomer has an ethylenically unsaturated bond and the homopolymer has a glass transition temperature of 30 ° C to 250 ° C, the soft monomer has an ethylenically unsaturated bond and the glass transition temperature of the homopolymer is from 10 ° C to -80 ° C Is a monomolecular monomer. In addition, the shell monomer mixture preferably further comprises an unsaturated monomer having an epoxy group. The hard monomer may be at least one selected from the group consisting of methyl methacrylate, ethyl methacrylate, butyl methacrylate, acrylonitrile, methacrylonitrile, isobornyl acrylate and isobornyl methacrylate , And the soft monomer is selected from the group consisting of methyl acrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate, octyl acrylate, ethylhexyl acrylate, ethylhexyl methacrylate and lauryl methacrylate The unsaturated monomer having an epoxy group is preferably selected from the group consisting of glycidyl acrylate, glycidyl methacrylate, 1,2-epoxy-9-decene (1 2-epoxy-9-decene, 1,2-epoxy-5-hexene and 4-vinyl-1-cyclohexene- - 1-cyclohexene-1,2-epoxide, limonene-1,2-epoxide, and allyl glycidyl ether. . In addition, the shell monomer mixture may further comprise a chain transfer agent. The emulsifier used in the process for producing the starch-based polymer particle emulsion for a pressure sensitive adhesive according to the present invention is preferably composed of a combination of an anionic reactive emulsifier and a nonionic reactive emulsifier, The reactive emulsifier may be selected from the group consisting of a vinyl group, an allyl group, an acryloyl group, a methacryloyl group, a propenyl group, a vinylidene group, And at least one functional group selected from a vinylene group.

The method for producing the starch-based polymer particle emulsion according to the present invention uses a starch liquefied liquid containing starch lysate as a base material. A method for producing a starch-based polymer particle emulsion according to the present invention will be described in detail first, followed by a description of a method for producing a starch-based liquefied liquid. The step of preparing a starch lysate containing starch hydrolyzate consists of adding a starch hydrolyzing enzyme to the starch suspension and decomposing the starch under predetermined pH and temperature conditions. At this time, the decomposition of the starch can be carried out by a batch-cooking or a jet-cooking method, and it is preferable to obtain a starch liquefied liquid containing starch hydrolyzate by the intermittent method. The intermittent method may be performed by reacting starch and starch degrading enzyme at 50 to 150 ° C, preferably 80 to 120 ° C for 30 to 300 minutes, preferably 60 to 200 minutes. The starcholytic enzyme includes alpha-amylase, beta-amylase, gluco-amylase, iso-amylase and the like, preferably mesophilic alpha-amylase or heat resistant alpha-amylase. The above starcholytic enzyme is commercially available. For example, when starch hydrolysis is carried out by the intermittent method, the pH of the starch suspension is preferably adjusted to a range of 4 to 8, and the amount of the starch degrading enzyme is 0.001 to 10 parts by weight , Preferably 0.01 to 1 part by weight, although it is not particularly limited.

When the starch hydrolyzate containing the starch hydrolyzate is prepared, the starch hydrolyzate is then polymerized with the core monomer mixture to form a core. Specifically, an emulsifier is added to and mixed with the starch liquefied liquid, and then the core monomer mixture and the polymerization initiator are added to the starch liquid mixture to perform a polymerization reaction. An aqueous emulsion containing a core made of a starch-based copolymer can be obtained by the production step of the core. The polymerization initiator may be a thermal decomposition initiator or an oxidation-reduction initiator capable of radical polymerization, and examples thereof include sodium persulfate, potassium persulfate, t-butyl hydroperoxide, 2,2-azobisbutyronitrile, , 2'-azobis-2-methylbutyronitrile, cumene hydroperoxide and the like can be used, and water-soluble initiators such as sodium persulfate, potassium persulfate, and t-butyl hydroperoxide can be preferably used. If necessary, a reducing agent such as ascorbic acid, sodium formaldehyde sulfoxylate, sodium bisulfite and the like may be added. The polymerization initiator may be added before the addition of the monomer or may be added at the same time as the monomer, and the amount thereof may be in the range of 0.1 to 8 parts by weight, preferably 0.2 to 5 parts by weight, per 100 parts by weight of the core monomer mixture.

The polymerization reaction temperature, the polymerization reaction pressure and the polymerization reaction time are not particularly limited in the production step of the core, and are, for example, from 60 to 100 ° C, preferably from 70 to 90 ° C, from 0.01 to 10 bar, At a pressure of 5 bar for 20 to 120 minutes, preferably 30 to 90 minutes. The reaction product obtained by the polymerization reaction is aged for minimizing unreacted monomers and for progressing a sufficient polymerization reaction. The aging temperature is kept the same as the polymerization reaction temperature, and the aging time is not limited to a great extent. By aging the reaction product, a core made of a starch-based copolymer and an emulsion containing the same can be obtained.

After preparing an aqueous emulsion of a core consisting of a starch-based copolymer, a shell is formed on the core. The step of forming the shell on the core may include a step of adding a shell monomer mixture and a polymerization initiator to the emulsion containing the core and performing a polymerization reaction, and further, a step of further aging. The polymerization initiator may be added before the addition of the monomer or simultaneously with the monomer, and the amount thereof may be in the range of 0.1 to 8 parts by weight, preferably 0.2 to 5 parts by weight, per 100 parts by weight of the shell monomer mixture.

The polymerization reaction temperature, the polymerization reaction pressure and the polymerization reaction time in the shell formation step are not particularly limited, and are, for example, from 60 to 100 ° C, preferably from 70 to 90 ° C, from 0.01 to 10 bar, At a pressure of 5 bar for 60 to 240 minutes, preferably 100 to 200 minutes. The reaction product obtained by the polymerization reaction is aged for minimizing unreacted monomers and for progressing a sufficient polymerization reaction. The aging temperature is kept the same as the polymerization reaction temperature, and the aging time is not limited to a great extent. By aging the reaction product, starch-based polymer particles of core-shell structure and aqueous emulsion containing the starch-based polymer particles can be obtained.

The emulsion containing the starch-based polymer particles of the core-shell structure obtained by the formation of the core and shell is then cooled to 45-65 캜 and preferably post-treated to remove unreacted monomers. The post-treatment step for removing unreacted monomers can be carried out by a chemical method, a wet-removing method, or a high-temperature steam method, and is preferably carried out by a chemical method using an oxidizing agent and a reducing agent. The post-treatment step using the oxidizing agent and the reducing agent consists of adding an oxidizing agent and a reducing agent to the emulsion containing the starch-based polymer particles of the core-shell structure to induce oxidation and reduction reaction and aging. At this time, t-butyl hydroperoxide, cumenehydroperoxide and the like can be used as the oxidizing agent. Examples of the reducing agent include sodium hydrosulfite, sodium metabisulfite ) Can be used. The amount of the oxidizing agent and the reducing agent used in the post-treatment step is not particularly limited, and may be, for example, 0.001 to 1 part by weight, preferably 0.002 to 0.8 part by weight per 100 parts by weight of the emulsion. In the post-treatment step, the oxidation reaction and the reduction reaction may be carried out at about 40 to 60 DEG C for 10 to 100 minutes, preferably 20 to 40 minutes. In addition, the emulsion subjected to the oxidation reaction and the reduction reaction is aged to induce a sufficient reaction between the oxidizing agent and the reducing agent and the unreacted monomer. The aging is carried out at about 40 to 60 DEG C for 30 to 150 minutes, preferably 40 to 100 minutes .

3. For adhesive Starch-based  Polymer particles Emulsion  Usage

The starch-based polymer particle emulsion according to the present invention can be used as a pressure-sensitive adhesive. The pressure-sensitive adhesive may be composed of the starch-based polymer particle emulsion alone, or may include a starch-based polymer particle emulsion as a main component. For example, the pressure sensitive adhesive according to the present invention may further comprise an auxiliary additive selected from a thickener, a flame retardant, an adhesion promoter, a filler, a pigment, a diluent, and a precipitation inhibitor, if necessary, in addition to the starch-based polymer particle emulsion.

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

1. Starch The degradation product  Starch containing Liquefied  Produce

Preparation Example 1 of Starch Liquid Solution.

To 90 g of deionized water, 50 g of oxidized corn starch (manufacturer: Kobunshi Co., Ltd., Korea) was added and dispersed to prepare a starch suspension. In addition, 1 g of heat-resistant alpha-amylase (Liquozyme supra, Novozyme, Denmark) was diluted with 10 g of deionized water to prepare a starch hydrolyzate solution. Thereafter, the pH of the starch suspension was adjusted to about 6.0, 1.0 g of starch hydrolyzate was added thereto, and the mixture was reacted at about 97 캜 for about 90 minutes. After the reaction was completed, 0.4 g of hypochlorous acid was added to the reaction product to inactivate the enzyme and cooled to about 80 캜 to obtain a starch-liquefied liquid containing starch hydrolyzate. At this time, the solid content concentration of the starch liquid solution was about 35%.

2. Starch-based  An aqueous system comprising polymer particles Emulsion  Produce

Emulsion Preparation Example 1

Starch Liquid Liquid In a reactor containing the starch liquefied liquid obtained in Production Example 1, 180 g of deionized water, 10 g of an anionic reactive emulsifier (trade name: ADEKAREASOAP SR-20; supplier: Asahi Denka Kogyo KK) and 10 g of a nonionic reactive emulsifier 5 g of ADEKAREASOAP ER-20 supplied by Asahi Denka Kogyo KK) was charged and charged with nitrogen. Thereafter, the temperature of the reactor in a nitrogen atmosphere was raised to about 80 DEG C, and 50 g of a polymerization initiator solution (solution in which 1.3 g of potassium persulfate was dissolved in 25 g of deionized water), 50 g of n-butyl acrylate and 50 g of 2-ethylhexyl acrylate The resulting core monomer mixture was added dropwise over 60 minutes to proceed the copolymerization reaction. After completing the dropwise addition of the polymerization initiator solution and the core monomer mixture, the copolymerization reaction product was stirred at about 80 캜 for about 30 minutes and aged to obtain a core composed of the starch-based copolymer and an emulsion containing the same.

Thereafter, the temperature of the reactor containing the emulsion containing the core was maintained at about 80 캜, and a polymerization initiator solution (a solution in which 1.5 g of potassium persulfate was dissolved in 30 g of deionized water), 25 g of methyl methacrylate, A shell monomer mixture composed of 305 g of acrylate, 20 g of acrylic acid and 1.3 g of n-dodecyl mercaptan was added dropwise for about 180 minutes to carry out the copolymerization reaction on the core surface to form a shell. After completing the dropwise addition of the polymerization initiator solution and the shell monomer mixture, the copolymerization reaction product was agitated at about 80 캜 for about 60 minutes and aged to obtain a core-shell structure starch-based copolymer particles and an emulsion containing the same. Thereafter, the pH of the emulsion containing the starch-based copolymer particles of core-shell structure obtained with 25% ammonia water was adjusted to about 7.0 to obtain an aqueous emulsion having a solid content of about 50% by weight and a viscosity of about 590 cPs . The viscosity was measured with a Brookfield viscometer under the conditions of KS M ISO 2555 Test Method, Spindle No # 2 and 60 rpm.

Emulsion Preparation Example 2

Starch Liquid Liquid In a reactor containing the starch liquefied liquid obtained in Production Example 1, 180 g of deionized water, 10 g of an anionic reactive emulsifier (trade name: ADEKAREASOAP SR-20; supplier: Asahi Denka Kogyo KK) and 10 g of a nonionic reactive emulsifier 5 g of ADEKAREASOAP ER-20 supplied by Asahi Denka Kogyo KK) was charged and charged with nitrogen. Thereafter, the temperature of the reactor in a nitrogen atmosphere was raised to about 80 DEG C, and 50 g of a polymerization initiator solution (solution in which 1.3 g of potassium persulfate was dissolved in 25 g of deionized water), 50 g of n-butyl acrylate and 50 g of 2-ethylhexyl acrylate The resulting core monomer mixture was added dropwise over 60 minutes to proceed the copolymerization reaction. After completing the dropwise addition of the polymerization initiator solution and the core monomer mixture, the copolymerization reaction product was stirred at about 80 캜 for about 30 minutes and aged to obtain a core composed of the starch-based copolymer and an emulsion containing the same.

Thereafter, the temperature of the reactor containing the emulsion containing the core was maintained at about 80 캜, and a polymerization initiator solution (a solution in which 1.5 g of potassium persulfate was dissolved in 30 g of deionized water), 25 g of methyl methacrylate, A shell monomer mixture consisting of 300 g of acrylate, 20 g of acrylic acid, 5 g of glycidyl methacrylate and 1.3 g of n-dodecyl mercaptan was added dropwise for about 180 minutes to carry out the copolymerization reaction on the core surface to form a shell. After completing the dropwise addition of the polymerization initiator solution and the shell monomer mixture, the copolymerization reaction product was agitated at about 80 캜 for about 60 minutes and aged to obtain a core-shell structure starch-based copolymer particles and an emulsion containing the same. Thereafter, the pH of the emulsion containing the core-shell structure starch copolymer particles obtained with 25% ammonia water was adjusted to about 7.0 to obtain an aqueous emulsion having a solid content of about 50% by weight and a viscosity of about 620 cPs . The viscosity was measured with a Brookfield viscometer under the conditions of KS M ISO 2555 Test Method, Spindle No # 2 and 60 rpm.

Emulsion Comparative Preparation Example 1

Starch Liquid Liquid In a reactor containing the starch liquefied liquid obtained in Production Example 1, 180 g of deionized water, 10 g of an anionic reactive emulsifier (trade name: ADEKAREASOAP SR-20; supplier: Asahi Denka Kogyo KK) and 10 g of a nonionic reactive emulsifier 5 g of ADEKAREASOAP ER-20 supplied by Asahi Denka Kogyo KK) was charged and charged with nitrogen. Thereafter, the reactor in a nitrogen atmosphere was heated to about 80 占 폚, and a polymerization initiator solution (solution in which 2.8 g of potassium persulfate was dissolved in 55 g of deionized water), 350 g of n-butyl acrylate, 50 g of 2-ethylhexyl acrylate, A monomer mixture composed of 25 g of methyl methacrylate, 20 g of acrylic acid, 5 g of glycidyl methacrylate and 1.3 g of n-dodecyl mercaptan was added dropwise to the reactor over 3 hours to proceed the copolymerization reaction. After completing the dropwise addition of the polymerization initiator solution and the monomer mixture, the copolymerization reaction product was stirred at about 80 캜 for about 1 hour and aged to obtain starch-based copolymer particles and an emulsion containing the same. Thereafter, the pH of the emulsion containing the starch-based copolymer particles was adjusted to about 7.0 with 25% ammonia water to obtain an aqueous emulsion having a solid content of about 50% by weight and a viscosity of about 450 cPs. The viscosity was measured with a Brookfield viscometer under the conditions of KS M ISO 2555 Test Method, Spindle No # 2 and 60 rpm.

Emulsion Comparison Preparation Example 2

Starch Liquid Liquid In a reactor containing the starch liquefied liquid obtained in Production Example 1, 180 g of deionized water, 10 g of an anionic reactive emulsifier (trade name: ADEKAREASOAP SR-20; supplier: Asahi Denka Kogyo KK) and 10 g of a nonionic reactive emulsifier 5 g of ADEKAREASOAP ER-20 supplied by Asahi Denka Kogyo KK) was charged and charged with nitrogen. Thereafter, the temperature of the reactor in a nitrogen atmosphere was raised to about 80 DEG C, and 50 g of a polymerization initiator solution (solution in which 1.3 g of potassium persulfate was dissolved in 25 g of deionized water), 50 g of n-butyl acrylate and 50 g of 2-ethylhexyl acrylate The resulting core monomer mixture was added dropwise over 60 minutes to proceed the copolymerization reaction. After completing the dropwise addition of the polymerization initiator solution and the core monomer mixture, the copolymerization reaction product was stirred at about 80 캜 for about 30 minutes and aged to obtain a core composed of the starch-based copolymer and an emulsion containing the same.

Thereafter, the temperature of the reactor containing the emulsion containing the core was maintained at about 80 캜, and a polymerization initiator solution (a solution in which 1.5 g of potassium persulfate was dissolved in 30 g of deionized water), 25 g of methyl methacrylate, 325 g of acrylate and 1.3 g of n-dodecyl mercaptan was added dropwise for about 180 minutes to carry out the copolymerization reaction on the core surface to form a shell. After completion of the dropwise addition of the polymerization initiator solution and the shell monomer mixture, the copolymerization reaction product was agitated at about 80 캜 for about 60 minutes and aged to obtain an emulsion containing the core-shell structure starch-based copolymer particles. Thereafter, the pH of the emulsion containing the starch-based copolymer particles of core-shell structure obtained with 25% ammonia water was adjusted to about 7.0 to obtain an aqueous emulsion having a solid content of about 50% by weight and a viscosity of about 370 cPs . The viscosity was measured with a Brookfield viscometer under the conditions of KS M ISO 2555 Test Method, Spindle No # 2 and 60 rpm.

Emulsion Comparison Preparation Example 3

Starch Liquid Liquid In a reactor containing the starch liquefied liquid obtained in Production Example 1, 180 g of deionized water, 10 g of an anionic reactive emulsifier (trade name: ADEKAREASOAP SR-20; supplier: Asahi Denka Kogyo KK) and 10 g of a nonionic reactive emulsifier 5 g of ADEKAREASOAP ER-20 supplied by Asahi Denka Kogyo KK) was charged and charged with nitrogen. Thereafter, the temperature of the reactor in a nitrogen atmosphere was raised to about 80 DEG C, and 50 g of a polymerization initiator solution (solution in which 1.3 g of potassium persulfate was dissolved in 25 g of deionized water), 50 g of n-butyl acrylate and 50 g of 2-ethylhexyl acrylate The resulting core monomer mixture was added dropwise over 60 minutes to proceed the copolymerization reaction. After completing the dropwise addition of the polymerization initiator solution and the core monomer mixture, the copolymerization reaction product was stirred at about 80 캜 for about 30 minutes and aged to obtain a core composed of the starch-based copolymer and an emulsion containing the same.

Thereafter, the temperature of the reactor containing the emulsion containing the core was maintained at about 80 캜, and a polymerization initiator solution (a solution in which 1.5 g of potassium persulfate was dissolved in 30 g of deionized water), 25 g of methyl methacrylate, A shell monomer mixture consisting of 300 g of acrylate, 12.5 g of acrylic acid, 12.5 g of 2-hydroxyethyl acrylate, 5 g of glycidyl methacrylate and 1.3 g of n-dodecyl mercaptan was added dropwise over about 180 minutes to copolymerize The reaction was allowed to proceed and a shell was formed. After completing the dropwise addition of the polymerization initiator solution and the shell monomer mixture, the copolymerization reaction product was agitated at about 80 캜 for about 60 minutes and aged to obtain a core-shell structure starch-based copolymer particles and an emulsion containing the same. Thereafter, the pH of the emulsion containing the starch-based copolymer particles of core-shell structure obtained with 25% ammonia water was adjusted to about 7.0 to obtain an aqueous emulsion having a solid content of about 50% by weight and a viscosity of about 810 cPs . The viscosity was measured with a Brookfield viscometer under the conditions of KS M ISO 2555 Test Method, Spindle No # 2 and 60 rpm.

Emulsion Comparison Preparation Example 4

A pressure-sensitive adhesive was prepared by referring to the method of Example 1 disclosed in Korean Patent Publication No. 10-2002-0083283. Concretely, 646 g of deionized water and 2.7 g of sodium bicarbonate were simultaneously added to the reactor, the temperature of the reactor was raised to 80 ° C, and a polymerization initiator solution (solution in which 8.7 g of potassium persulfate was dissolved in 60 g of deionized water ) Was added and stirred for 10 minutes. Thereafter, the reactor was charged with 60 g of acrylic acid, 45 g of 2-hydroxyethyl acrylate, 930 g of butyl acrylate, 720 g of 2-ethylhexyl acrylate, A mixture of 480 g of deionized water, 9 g of nonionic emulsifier and 36 g of anionic emulsifier was added to the reactor over a period of 300 minutes and aged for 1 hour. Thereafter, the pH of the reactant was adjusted to about 7.0 with 25% ammonia water to obtain an aqueous emulsion having a solid content of about 50% by weight and a viscosity of about 530 cPs. The viscosity was measured with a Brookfield viscometer under the conditions of KS M ISO 2555 Test Method, Spindle No # 2 and 60 rpm.

3. Starch-based  An aqueous system comprising polymer particles Emulsion  Evaluation of properties related to adhesive

With regard to the pressure-sensitive adhesive properties of the water-based emulsion prepared in Emulsion Production Examples 1 to 2 and Emulsion Comparative Production Examples 1 to 4, initial adhesion, adhesion strength after 180 ° peel strength after adhering to the adherend, and re-peelability were measured.

* Initial Adhesion Force: The initial adhesive strength test method of KS T1028 was used. An aqueous emulsion was applied to the surface of the PET film to a thickness of about 30 탆 and stored at a temperature of about 60 캜 for 12 hours to form a coating film and left at room temperature for 24 hours. Thereafter, the ball tack No. of the test piece having the coating film formed thereon was measured using a ball tack tester (model name: TO 730; supplied by Test Co., Ltd., Korea). The larger the volume number in the bulk test, the greater the initial adhesion.

* 180 DEG peel adhesion strength: 180 DEG peel adhesion strength was measured according to the ASTM D3121-94 test method. An aqueous emulsion was applied to the surface of the PET film to a thickness of about 30 탆 and stored at a temperature of about 60 캜 for 12 hours to form a coating film and left at room temperature for 24 hours. Thereafter, a test piece having a coated film was attached to SUS # 304 and Glass, which were adhered to each other, and after a lapse of 30 minutes, the 180 degree peel adhesion strength was measured using an Instron universal testing machine.

* Re-peelability: An aqueous emulsion was coated on the surface of the PET film to a thickness of about 30 탆 and stored at a temperature of about 60 캜 for 12 hours to form a coating film and left at room temperature for 24 hours. Thereafter, a test piece having a coated film was attached to the mirror surface. Thereafter, the specimen attached to the mirror surface was kept in an oven at 50 DEG C for 1 hour and peeled off from the mirror surface. Thereafter, the residue generated on the mirror surface was visually observed to evaluate the re-peelability of the water-based emulsion. The evaluation criteria were good (no residue), moderate (little residue), and poor (large residue).

Table 1 shows the results of evaluating the adhesive properties of the aqueous emulsion prepared in Emulsion Production Examples 1 to 2 and Emulsion Comparative Production Examples 1 to 4.

division Water-based emulsion Emulsion Production Example 1 Emulsion Preparation Example 2 Emulsion Comparison Preparation Example 1 Emulsion Comparative Preparation Example 2 Emulsion Comparison Example 3 Emulsion Comparison Preparation Example 4 Initial Tack (Ball Tack No.) 9 9 3 9 8 11 180 DEG peel adhesion strength (gf / in) SUS adhered material 954 1098 258 950 629 830 Glass adhered material 960 1092 181 940 620 800 Re-peelability Good Good Bad Bad usually Good

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims. Therefore, the scope of the present invention should be construed as including all embodiments falling within the scope of the appended claims.

Claims (20)

As an aqueous emulsion containing water as dispersion medium and starch-based polymer particles and dispersion medium,
Wherein the starch-based polymer particles have a core-shell structure comprising a shell formed on the core by polymerization of a core and shell monomer mixture formed by polymerization of a starch decomposition product and a core monomer mixture,
Wherein the core monomer mixture contains at least two soft monomers having no hydroxyl groups and at the same time does not contain a hard monomer and an unsaturated carboxylic acid monomer,
Wherein the shell monomer mixture comprises a hard monomer having no hydroxyl group, a soft monomer having no hydroxyl group, and an unsaturated carboxylic acid monomer,
Wherein the hard monomer has an ethylenic unsaturated bond and the homopolymer has a glass transition temperature of from 30 캜 to 250 캜,
Wherein the soft monomer has an ethylenically unsaturated bond and the homopolymer has a glass transition temperature of from 10 캜 to -80 캜
Wherein the weight ratio of the core monomer mixture to the shell monomer mixture is from 5:95 to 30:70,
Wherein the weight ratio of the hard monomer to the soft monomer in the shell monomer mixture is from 2:98 to 20:80 and the content of the unsaturated carboxylic acid monomer is from 0.5 to 20 parts by weight per 100 parts by weight of the shell monomer mixture. Based polymer particle emulsion.
The method of claim 1, wherein the hard monomer is selected from the group consisting of methyl methacrylate, ethyl methacrylate, butyl methacrylate, acrylonitrile, methacrylonitrile, isobornyl acrylate, and isobornyl methacrylate. Based polymer particle emulsion for a pressure-sensitive adhesive.
The composition of claim 1, wherein the soft monomer is selected from the group consisting of methyl acrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate, octyl acrylate, ethylhexyl acrylate, ethylhexyl methacrylate and lauryl methacrylate Wherein the starch-based polymer particle emulsion for pressure-sensitive adhesive is composed of at least one selected from the group consisting of
The starch-based polymer particle emulsion for pressure-sensitive adhesive according to claim 1, wherein the unsaturated carboxylic acid monomer is at least one selected from the group consisting of acrylic acid, methacrylic acid, itaconic acid, maleic acid and fumaric acid .
The starch-based polymer particle emulsion for a pressure sensitive adhesive according to claim 1, wherein the shell monomer mixture further comprises an unsaturated monomer having an epoxy group.
The epoxy resin composition according to claim 5, wherein the unsaturated monomer having an epoxy group is selected from the group consisting of glycidyl acrylate, glycidyl methacrylate, 1,2-epoxy- 9-decene, 1,2-epoxy-5-hexene, 4-vinyl-1-cyclohexene- 1,2-epoxide, limonene-1,2-epoxide, and allyl glycidyl ether. In the present invention, Starch - based polymer particle emulsion for pressure sensitive adhesive.
The starch-based polymer particle emulsion for pressure-sensitive adhesive according to claim 5, wherein the content of the unsaturated monomer having an epoxy group is 0.1 to 10 parts by weight per 100 parts by weight of the shell monomer mixture.
The starch-based polymer particle emulsion for a pressure sensitive adhesive according to claim 1, wherein the shell monomer mixture further comprises a chain transfer agent.
9. The process of claim 8, wherein the chain transfer agent is selected from the group consisting of n-dodecyl mercaptan, t-dodecyl mercaptan, 1,5-pentanediol, 1,6-hexanediol, Methyl 3-mercaptopropionate, ethyl 3-mercaptopropionate, methyl 3-mercaptopropionate, methyl 3-mercaptopropionate, ethyl 3-mercaptopropionate, ethyl 3-mercaptopropionate, But are not limited to, erythritol tetrakis (3-mercaptopropionate), 2-ethylhexyl mercaptoacetate, ethyl 2-mercaptoacetate, 2-hydroxymethyl- And tetrakis (2-mercaptoacetate). 2. The starch-based polymer particle emulsion for pressure-sensitive adhesive according to claim 1,
The starch-based polymer particle emulsion for a pressure-sensitive adhesive according to claim 8, wherein the content of the chain transfer agent is 0.01 to 1 part by weight per 100 parts by weight of the shell monomer mixture.
The starch-based polymer particle emulsion for pressure-sensitive adhesive according to claim 1, wherein the aqueous emulsion further comprises an emulsifier.
The starch-based polymer particle emulsion for a pressure sensitive adhesive according to claim 11, wherein the emulsifier comprises a combination of an anionic emulsifier and a nonionic emulsifier.
13. The method of claim 12, wherein the anionic emulsifier or nonionic emulsifier is selected from the group consisting of a vinyl group, an allyl group, an acryloyl group, a methacryloyl group, a propenyl group, wherein the reactive emulsifier is a reactive emulsifier having at least one functional group selected from the group consisting of a vinylidene group and a vinylene group.
The starch-based polymer particle emulsion for pressure-sensitive adhesive according to claim 11, wherein the content of the emulsifier is 0.5 to 10 parts by weight based on 100 parts by weight of the starch-based polymer particles.
15. The starch-based polymer particle emulsion for a pressure sensitive adhesive according to any one of claims 1 to 14, wherein the weight ratio of the monomers forming the starch decomposition product to the starch polymer particles is from 5:95 to 30:70.
Adding an emulsifier to a starch liquefied liquid containing a starch hydrolyzate and mixing, adding a core monomer mixture and a polymerization initiator thereto, and conducting a polymerization reaction to obtain an aqueous emulsion containing a core composed of a starch-based copolymer; And adding a shell monomer mixture and a polymerization initiator to the emulsion containing the core and polymerizing to form a shell on the core,
Wherein the core monomer mixture contains at least two soft monomers having no hydroxyl groups and at the same time does not contain a hard monomer and an unsaturated carboxylic acid monomer,
Wherein the shell monomer mixture comprises a hard monomer having no hydroxyl group, a soft monomer having no hydroxyl group, and an unsaturated carboxylic acid monomer,
Wherein the hard monomer has an ethylenic unsaturated bond and the homopolymer has a glass transition temperature of from 30 캜 to 250 캜,
Wherein the soft monomer has an ethylenic unsaturated bond and the homopolymer has a glass transition temperature of from 10 캜 to -80 캜,
Wherein the weight ratio of the core monomer mixture to the shell monomer mixture is from 5:95 to 30:70,
Wherein the weight ratio of the hard monomer to the soft monomer in the shell monomer mixture is from 2:98 to 20:80 and the content of the unsaturated carboxylic acid monomer is from 0.5 to 20 parts by weight per 100 parts by weight of the shell monomer mixture. (Process for producing polymer particles emulsion).
17. The method according to claim 16, wherein the shell monomer mixture further comprises an unsaturated monomer having an epoxy group.
17. The method of producing a starch-based polymer particle emulsion for a pressure sensitive adhesive according to claim 16, wherein the shell monomer mixture further comprises a chain transfer agent.
17. The method of claim 16, wherein the emulsifier comprises a combination of an anionic reactive emulsifier and a nonionic reactive emulsifier, wherein the anionic reactive emulsifier and the nonionic reactive emulsifier comprise a vinyl group, an allyl group having at least one functional group selected from the group consisting of an alkyl group, an acryloyl group, a methacryloyl group, a propenyl group, a vinylidene group and a vinylene group Wherein the starch-based polymer particle emulsion for a pressure-sensitive adhesive is produced.
18. The method of claim 17,
Wherein the hard monomer is at least one selected from the group consisting of methyl methacrylate, ethyl methacrylate, butyl methacrylate, acrylonitrile, methacrylonitrile, isobornyl acrylate, and isobornyl methacrylate,
The soft monomer may be one selected from the group consisting of methyl acrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate, octyl acrylate, ethylhexyl acrylate, ethylhexyl methacrylate and lauryl methacrylate Or more,
The unsaturated monomer having an epoxy group may be selected from the group consisting of glycidyl acrylate, glycidyl methacrylate, 1,2-epoxy-9-decene, 2-epoxy-5-hexene, 4-vinyl-1-cyclohexene-1,2-epoxide, , Limonene-1,2-epoxide, and allyl glycidyl ether. The starch-based polymer particles for a pressure-sensitive adhesive composition according to claim 1, ≪ / RTI >