KR101465210B1 - Improved non-extended polyester-based film, and preparation method thereof - Google Patents

Abstract

The present invention relates to a non-oriented polyester film improved in heat resistance and flexibility, a method for producing the same, and a construction interior film for wallpaper or flooring comprising the same.

Description

TECHNICAL FIELD [0001] The present invention relates to an improved non-stretched polyester film, and an improved non-stretched polyester film,

The present invention relates to a non-oriented polyester film improved in heat resistance and flexibility, a method for producing the same, and a construction interior film for wallpaper or flooring comprising the same.

Recently, as the seriousness of global environmental pollution has become known, social interest in the misuse of existing petroleum plastic materials is increasing. Petroleum-based plastic materials such as PVC, PS and the like are used for discharging toxic gas harmful to human body Even if it is fully decomposed, it is said to require more than 500 years. For this reason, petroleum-based plastic materials are regarded as the main cause of global environmental pollution, and it is desirable to replace them with biocompatible plastics materials in consideration of environmental costs due to various environmental regulations, even though the prices are somewhat higher than conventional plastics. Despite the high cost of biocompatible plastics due to limited oil reserves, increasing supply prices, and international environmental regulations, the advantages are becoming more and more evident. In this context, research is being accelerated in various fields to find new efficient biomaterials that can replace petroleum plastics.

Representative biochemical plastics include polylactic acid (polylactic acid, PLA). Accordingly, many studies have been made on this, and for example, United States Patent Application Publication No. 2009/0085260 discloses a film containing poly (lactic acid) or the like. Although many bio-based plastics have been developed, there is no material that can be practically used for industrial purposes as much as polylactic acid, considering economical and functional properties. Accordingly, application techniques capable of maintaining the merits of polylactic acid . Poly-lactic acid can be obtained through fermentation and chemical process steps using bio-materials such as potatoes and corn, and L-poly lactic acid can be obtained. Because L-poly lactic acid is difficult to process in extrusion process like film, artificially synthesized D- Polylactic acid is synthesized and then mixed and used. Plastic materials obtained from bio raw materials such as polylactic acid and cellulose have a high concentration of methyl groups in common, so that there is a problem in that when the final product is made into a film form, flexibility is not sufficient and processing and construction are difficult. In addition, since the polythusic acid has a lower heat resistance than that of the polyester resins such as PET and PBT, the physical properties of the poly (lactic acid) are lowered due to pyrolysis during processing and processing steps such as compounding (kneading) and extrusion.

In order to solve such problems, prior art has improved flexibility by mixing polyhydroxyalkanoates (PHAs) and polybutylene adipate-co-terephthalate (PBAT) These resins are poor in kneadability with polylactic acid, so that not only transparency which is most important in the film is deteriorated but also heat resistance is lowered.

The present invention provides a lead-free polyester film containing L-polylactic acid to which glycidyl methacrylate (GMA) is bonded, and a process for producing the lead-free polyester film.

However, the problems to be solved by the present invention are not limited to the above-mentioned problems, and other matters not mentioned can be clearly understood by those skilled in the art from the following description.

The first aspect of the present invention provides a lead-free polyester-based film comprising a polyester-based resin produced by mixing glycidyl methacrylate (GMA) with L-poly lactic acid and D-poly lactic acid .

According to a second aspect of the present invention, there is provided a method for producing L-polylactic acid, which comprises synthesizing L-polylactic acid to which glycidyl methacrylate (GMA) is bonded; And a step of preparing a film comprising a polyester-based resin obtained by mixing D-polylactic acid with L-polylactic acid to which glycidyl methacrylate (GMA) is bonded, to a non-oriented polyester film Of the present invention.

A third aspect of the invention provides a building interior film for a wallpaper or flooring comprising a film according to the first aspect of the present application.

According to the prior art, plastic materials obtained from bio raw materials such as polylactic acid and cellulose have a very high methyl group concentration, so that when the final product is made into a film form, flexibility is not sufficient and processing and construction are difficult, The heat resistance is lower than that of PET or PBT, which is a base resin, so that the physical properties are degraded due to pyrolysis at the process and processing stage such as compounding (kneading) and extrusion, but according to the present invention, such difficulties can be solved.

In one embodiment of the present invention, a non-oriented polyester film comprising a polyester resin prepared by mixing glycidyl methacrylate (GMA) with L-poly lactic acid and D-poly lactic acid is prepared A non-oriented polyester film having improved heat resistance and flexibility can be easily produced, and a film for a building interior material for wallpaper or flooring can be produced by using such a non-oriented polyester film.

1 is a ¹³ C-NMR spectrum showing the chemical structure of L-poly lactic acid coupled with glycidyl methacrylate (GMA) prepared according to one embodiment of the present invention.
2 is a measurement result of Dynamic Mechanical Analyzer (DMA) of L-poly lactic acid coupled with glycidyl methacrylate (GMA) prepared according to one embodiment of the present invention.
Fig. 3 is a photograph of wallpaper produced using L-poly lactic acid combined with glycidyl methacrylate (GMA) produced according to one embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily carry out the present invention. It should be understood, however, that the present invention may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. In the drawings, the same reference numbers are used throughout the specification to refer to the same or like parts.

Throughout this specification, when a part is referred to as being "connected" to another part, it is not limited to a case where it is "directly connected" but also includes the case where it is "electrically connected" do.

Throughout this specification, when a member is "on " another member, it includes not only when the member is in contact with the other member, but also when there is another member between the two members.

Throughout this specification, when an element is referred to as "including " an element, it is understood that the element may include other elements as well, without departing from the other elements unless specifically stated otherwise. The terms "about "," substantially ", etc. used to the extent that they are used throughout the specification are intended to be taken to mean the approximation of the manufacturing and material tolerances inherent in the stated sense, Accurate or absolute numbers are used to help prevent unauthorized exploitation by unauthorized intruders of the referenced disclosure. The word " step (or step) "or" step "used to the extent that it is used throughout the specification does not mean" step for.

Throughout this specification, the term "combination thereof" included in the expression of the machine form means one or more combinations or combinations selected from the group consisting of the constituents described in the expression of the machine form, And the like.

Hereinafter, embodiments will be described in more detail with respect to the present application, but the present invention is not limited thereto.

The first aspect of the present invention provides a lead-free polyester-based film comprising a polyester-based resin produced by mixing glycidyl methacrylate (GMA) with L-poly lactic acid and D-poly lactic acid . A non-oriented film is a film in the form of a sheet in which crystallization by stretching is not carried out due to the contradictory concept of a stretched film, and is merely a film in which only crystals are formed by heat treatment.

According to one embodiment herein, the L-poly lactic acid is at least about 80 parts by weight, and the D-poly lactic acid is from about 1 part to about 15 parts by weight, based on the polyester film, But it may not be limited thereto.

For example, based on the polyester film, the L-poly lactic acid may comprise at least about 80 parts by weight, at least about 85 parts by weight, at least about 90 parts by weight, or at least about 95 parts by weight, From about 1 part by weight to about 5 parts by weight, from about 1 part by weight to about 15 parts by weight, from about 1 part by weight to about 13 parts by weight, from about 1 part by weight to about 10 parts by weight, from about 1 to about 8 parts by weight, From about 3 parts by weight to about 10 parts by weight, from about 3 parts by weight to about 8 parts by weight, from about 1 part by weight to about 3 parts by weight, from 3 parts by weight to about 15 parts by weight, from about 3 parts by weight to about 13 parts by weight, From about 5 parts by weight to about 5 parts by weight, from about 5 parts by weight to about 15 parts by weight, from about 5 parts by weight to about 13 parts by weight, from about 5 parts by weight to about 10 parts by weight, from about 5 parts by weight to about 8 parts by weight From about 8 parts by weight to about 15 parts by weight, from about 8 parts by weight to about 13 parts by weight, from about 8 parts by weight to about 10 parts by weight, from about 10 parts by weight to about 10 parts by weight, About 15 parts by weight, about 10 parts by weight to about 13 parts by weight, or about 13 parts by weight to about 15 parts by weight. According to one embodiment of the present invention, organic additives other than L-polylactic acid to which glycidyl methacrylate (GMA) is bonded and D-polylactic acid, such as inorganic fillers and flame retardants, may be used.

According to one embodiment of the present application, the geurisi methacrylate (GMA) is combined L- polylactic acid has a melting temperature (T _m) of from about 180 to about 200 ℃ ℃, about 50,000 g / mol to about 100,000 g / (M _n ) of the number average molecular weight (M _n ), although the present invention is not limited thereto. When the melting temperature (T _m ) is less than about 180 ° C, improvement in heat resistance of the film can not be expected. When the reaction temperature is increased to more than about 200 ° C or the reaction time is prolonged, yellowing by thermal decomposition occurs, The incorporation of higher copolymers reduces the flexibility of the film and is not applicable to our application. For example, the glycidyl methacrylate (GMA) coupled L-poly lactic acid may be reacted at a temperature of about 180 캜 to about 200 캜, about 180 캜 to about 195 캜, about 180 캜 to about 190 캜, (T _m ) of from about 185 캜 to about 185 캜 to about 200 캜, from about 190 캜 to about 200 캜, from about 195 캜 to about 200 캜, or from about 190 캜 to about 195 캜, . The glycidyl methacrylate (GMA) -bonded L-polylactic acid may be used in an amount of about 50,000 g / mol to about 100,000 g / mol, about 50,000 g / mol to about 90,000 g / mol, about 50,000 g / mol to about From about 50,000 g / mol to about 60,000 g / mol, from about 60,000 g / mol to about 90,000 g / mol, from about 50,000 g / mol to about 70,000 g / mol, from about 50,000 g / mol, from about 60,000 g / mol to about 80,000 g / mol, from about 60,000 g / mol to about 70,000 g / mol, from about 70,000 g / mol to about 100,000 g / mol, from about 70,000 g / , From about 70,000 g / mol to about 80,000 g / mol, from about 80,000 g / mol to about 100,000 g / mol, from about 80,000 g / mol to about 90,000 g / mol, or from about 90,000 g / mol to about 100,000 g / mol but it may be one having a number average molecular weight (M _n), may not be limited thereto.

According to one embodiment of the present invention, the polyester film has a tan δ (δ = loss Young's modulus / Young's modulus) value of the film sample of about 2.5 to about 3.5, and T _g But is not limited to, the range from about < RTI ID = 0.0 > 70 C < / RTI > For example, the polyester film can be judged as having flexibility when the tan δ is about 2.5 or more and the glass transition temperature (T _g ) is about 75 ° C. or less, while tan δ is less than about 2.5, When the glass transition temperature (T _g ) value exceeds about 75 ° C, the film is stiff and can not be used for architectural interior materials as in the present invention. For example, the polyester film may have a tan δ value (δ = loss Young's modulus / Young's modulus) of about 2.5 to about 3.5, about 2.6 to about 3.5, about 2.7 to about 3.5, about 2.8 to about 3.5, 3.5, and about 3 to about 3.5, from about 3.1 to about 3.5, about 3.2 to about 3.5, about 3.3 to about 3.5, or from about 3.4 to about 3.5, and T _g From about 70 캜 to about 75 캜, from about 71 캜 to about 75 캜, from about 72 캜 to about 75 캜, from about 73 캜 to about 75 캜, from about 74 캜 to about 75 캜, About 72 ° C to about 74 ° C, about 73 ° C to about 74 ° C, about 71 ° C to about 73 ° C, about 71 ° C to about 72 ° C, or about 72 ° C to about 73 ° C. .

According to one embodiment of the present invention, the non-extensible polyester film may have improved heat resistance or flexibility, but the present invention is not limited thereto.

According to one embodiment of the present invention, the non-extensible film forming apparatus applicable to the present invention includes a triangular belt method, a polising roll method, and the like. However, the present invention is not limited thereto, This is the case.

According to a second aspect of the present invention, there is provided a method for producing L-polylactic acid, which comprises synthesizing L-polylactic acid to which glycidyl methacrylate (GMA) is bonded; And a step of preparing a film comprising a polyester-based resin obtained by mixing D-polylactic acid with L-polylactic acid to which glycidyl methacrylate (GMA) is bonded, to a non-oriented polyester film Of the present invention.

According to one embodiment of the present application, the geurisi methacrylate (GMA) is combined L- polylactic acid has a melting temperature (T _m) of from about 180 to about 200 ℃ ℃, about 50,000 g / mol to about 100,000 g / (M _n ) of the number average molecular weight (M _n ), although the present invention is not limited thereto. When the melting temperature (T _m ) is less than about 180 ° C, improvement in heat resistance of the film can not be expected. When the reaction temperature is raised to more than about 200 ° C or the reaction time is prolonged, yellowing by thermal decomposition occurs, The incorporation of high temperature copolymers reduces the flexibility of the film and is not applicable to our application.

For example, the glycidyl methacrylate (GMA) coupled L-poly lactic acid may be reacted at a temperature of about 180 캜 to about 200 캜, about 180 캜 to about 195 캜, about 180 캜 to about 190 캜, (T _m ) of from about 185 캜 to about 185 캜 to about 200 캜, from about 190 캜 to about 200 캜, from about 195 캜 to about 200 캜, or from about 190 캜 to about 195 캜, . The glycidyl methacrylate (GMA) -bonded L-polylactic acid may be used in an amount of about 50,000 g / mol to about 100,000 g / mol, about 50,000 g / mol to about 90,000 g / mol, about 50,000 g / mol to about From about 50,000 g / mol to about 60,000 g / mol, from about 60,000 g / mol to about 90,000 g / mol, from about 50,000 g / mol to about 70,000 g / mol, from about 50,000 g / mol, from about 60,000 g / mol to about 80,000 g / mol, from about 60,000 g / mol to about 70,000 g / mol, from about 70,000 g / mol to about 100,000 g / mol, from about 70,000 g / , From about 70,000 g / mol to about 80,000 g / mol, from about 80,000 g / mol to about 100,000 g / mol, from about 80,000 g / mol to about 90,000 g / mol, or from about 90,000 g / mol to about 100,000 g / mol but it may be one having a number average molecular weight (M _n), may not be limited thereto.

According to one embodiment of the present invention, the L-poly lactic acid may be obtained by mixing and polymerizing L-lactide, an initiator, and a polymerization catalyst as monomers, but may not be limited thereto.

According to one embodiment of the disclosure, the initiator is selected from the group consisting of lauryl alcohol, hetero-bimetallic alkoxide, hetero-bimetallic aryloxide, and potassium benzoate. But are not limited to, those selected from the group consisting of

According to one embodiment of the present invention, the polymerization catalyst may include, but is not limited to, tin octoate [Sn (II) octoate] or aluminum octoate [Al (III) octoate]. The initiator may be added in an amount of about 0.1 part by weight to about 0.5 part by weight, and the polymerization catalyst may be added in an amount of about 0.1 part by weight to about 1 part by weight. If the amount of the initiator added is less than about 0.1 parts by weight, the reaction may not proceed or is delayed. If the amount of the initiator exceeds about 0.5 parts by weight, the molecular weight of the synthesized resin may decrease or may be thermally changed by unreacted additives. If the concentration of the polymerization catalyst is less than about 0.1 parts by weight, the degree of polymerization may be lowered and a high molecular weight may not be obtained. If the concentration is more than about 1 part by weight, the polymer may rapidly polymerize to deteriorate the mechanical and thermal properties of the resin.

According to an embodiment of the present invention, the step of synthesizing glycidyl methacrylate (GMA) coupled L-poly lactic acid comprises adding L-poly lactic acid to GMA and a reaction- But may not be limited thereto. For example, about 10 parts by weight to about 15 parts by weight of GMA and about 0.1 to about 0.5 parts by weight of a reaction-binding catalyst are further added to synthesize glycidyl methacrylate (GMA) coupled L-poly lactic acid .

According to one embodiment of the present invention, the reaction-bonding catalyst may include, but not limited to, zinc octoate [Zn (II) octoate] or titanium chloride [Ti (II) chloride]. Unlike the above-mentioned polymerization catalyst, the reaction-bonding catalyst used is zinc octoate [Zn (Ⅱ) octoate] or titanium chloride [Ti (Ⅱ) chloride], and the polymerization catalyst and the reaction- And it may be effective, but not limited thereto, to go to a plurality of catalysts.

According to one embodiment of the present application, a polymerization solvent, 2,2-azobis-isobutyronitrile (AIBN), and GMA are further added to L-poly lactic acid to which glycidyl methacrylate (GMA) Polylactic acid, and reacting the resulting L-polylactic acid to increase the molecular weight of the L-poly lactic acid. For example, from about 0.1 part by weight to about 1 part by weight of a polymerization solvent, from about 0.1 part by weight to about 1 part by weight of 2,2-azobis-isobutyronitrile [ 2,2-azobis-isobutyronityronitrile: AIBN], and about 10 parts by weight to about 15 parts by weight of GMA may be further added to increase the molecular weight of the L-linked polyunsaturated fatty acid. In order to improve the flexibility and heat resistance of the film, the molecular weight of the L-poly lactic acid should be high and the method of bonding L-poly lactic acid to GMA may be a method of increasing the molecular weight. In addition, as a conventional technique, a method of increasing the molecular weight using a solid phase polymerization method can also be used.

According to one embodiment of the present invention, the polymerization solvent may include, but is not limited to, those selected from the group consisting of methyl acetate, ethyl acetate, and butyl acetate.

According to one embodiment of the invention, the polyester film has a glass transition temperature (T _g ) value of from about 70 캜 to about 75 캜, wherein the value of tan δ (δ = loss Young's modulus / storage modulus) is about 2.5 to about 3.5, But are not limited thereto. For example, the polyester film can be judged as having flexibility when the tan δ is about 2.5 or more and the glass transition temperature (T _g ) is about 75 ° C. or less, while tan δ is less than about 2.5 , the film stiffness can not be used for building interior materials, as herein when the temperature exceeds the glass transition (T _g) values of about 75 ℃. For example, the polyester film may have a tan δ value (δ = loss Young's modulus / Young's modulus) of about 2.5 to about 3.5, about 2.6 to about 3.5, about 2.7 to about 3.5, about 2.8 to about 3.5, 3.5, and about 3 to about 3.5, from about 3.1 to about 3.5, about 3.2 to about 3.5, about 3.3 to about 3.5, or from about 3.4 to about 3.5, and T _g From about 70 캜 to about 75 캜, from about 71 캜 to about 75 캜, from about 72 캜 to about 75 캜, from about 73 캜 to about 75 캜, from about 74 캜 to about 75 캜, About 72 ° C to about 74 ° C, about 73 ° C to about 74 ° C, about 71 ° C to about 73 ° C, about 71 ° C to about 72 ° C, or about 72 ° C to about 73 ° C. .

According to one embodiment of the present invention, the step of producing a film comprising the polyester-based resin comprises the step of adding D-polylactic acid, inorganic particles, and functional groups to L-polylactic acid to which glycidyl methacrylate (GMA) But may also include, but not limited to, adding and mixing additives. For example, D-polylactic acid, inorganic particles, and functional additives are added to and mixed with L-poly lactic acid to which glycidyl methacrylate (GMA) is bonded, and the mixture is stirred at a temperature of about 100 ° C to about 120 ° C for about 1 hour Extrusion, and film forming steps at a temperature of from about 220 DEG C to about 260 DEG C to produce a lead-free film having a thickness of from about 100 mu m to about 500 mu m. For example, the thickness of the film may be from about 100 [mu] m to about 500 [mu] m, but is not limited thereto.

According to one embodiment of the present application, there is provided a polyester film comprising at least about 80 parts by weight of glycidyl methacrylate (GMA) bonded L-polylactic acid and from about 1 part to about 15 parts by weight of D But may be, but not limited to, polylactic acid. At least about 80 parts by weight, at least about 85 parts by weight, at least about 90 parts by weight, or at least about 95 parts by weight of the glycidyl methacrylate (GMA) linked L- From about 1 part by weight to about 15 parts by weight, from about 1 part by weight to about 13 parts by weight, from about 1 part by weight to about 10 parts by weight, from about 1 part by weight to about 8 parts by weight, from about 1 part by weight to about About 3 parts by weight to about 15 parts by weight, about 3 parts by weight to about 13 parts by weight, about 3 parts by weight to about 10 parts by weight, about 3 parts by weight to about 5 parts by weight, 8 parts by weight, about 3 parts by weight to about 5 parts by weight, about 5 parts by weight to about 15 parts by weight, about 5 parts by weight to about 13 parts by weight, about 5 parts by weight to about 10 parts by weight, 8 parts by weight, about 8 parts by weight to about 15 parts by weight, about 8 parts by weight to about 13 parts by weight, about 8 parts by weight to about 10 parts by weight, about 10 From about 10 parts by weight to about 13 parts by weight, or from about 13 parts by weight to about 15 parts by weight of the D-poly lactic acid.

According to one embodiment of the present invention, the inorganic particles may include, but are not limited to, those selected from the group consisting of silica, calcium carbonate, and titanium dioxide.

According to one embodiment of the present invention, the functional additive may include, but is not limited to, selected from the group consisting of a flame retardant, a brightener, a foaming agent, and a charge control agent. For example, the inorganic particles and the functional additives are not limited thereto, and all known inorganic particles and functional additives may be used.

According to an embodiment of the present invention, the D-poly lactic acid, the inorganic particles, and the functional additive may be added to the L-poly lactic acid to prepare a mixture, followed by drying, melting, extruding, But may not be limited thereto. For example, after the L-poly lactic acid is prepared by adding and mixing D-poly lactic acid, inorganic particles, and functional additives, drying is performed at about 90 ° C to about 110 ° C for about 1 hour to about 2 hours, And is melted at a temperature higher by about 30 ° C to about 40 ° C than the melting point (T _m ) of the poly (lactic acid), and is extruded using a T-die type facility. The extruded resin is quenched by a casting roll so that the film surface becomes amorphous and the film whose surface becomes amorphous is subjected to repetitive heat treatment at a temperature condition between the glass transition temperature (T _g ) and the melting temperature (T _m ) A non-oriented film can be formed.

The third aspect of the present application provides a building interior film for wallpaper or flooring comprising a film according to the first aspect of the present application.

According to one embodiment of the present invention, an L-polylactic acid having glycidyl methacrylate (GMA) combined with excellent reactivity and heat resistance is prepared, and at least about 80 parts by weight of the mixture is blended to produce a lead- Can be used.

According to one embodiment of the present invention, L-polylactic acid having glycidyl methacrylate (GMA) bonded thereto can be synthesized in order to improve heat resistance and flexibility, which are the greatest weak points of conventional poly (lactic acid). Since the lactide used as a monomer is sensitive to water and is opened by contact, the hydroxyl group of the dimer form and the terminal of the carboxyl group are formed to lose activity. Therefore, the lactide used for the synthesis is a mixture of It may be, but not limited to, performing in a glove box. Examples of the initiator used herein include lauryl alcohol (dodecanol), hetero-bimetallic alkoxide, hetero-bimetallic aryloxide, and potassium benzoate As the polymerization catalyst, there are tin octoate [Sn (II) octoate] or aluminum octoate [Al (III) octoate].

According to one embodiment of the present disclosure, there is provided a process for the preparation of L-polylactic acid, comprising reacting L-lactide, from about 0.1 part by weight to about 0.5 part by weight of initiator and from about 0.1 part by weight to about 1 part by weight of polymerization Polymerization can be carried out at a temperature of from about 130 ° C to about 150 ° C by immersing the catalyst-added round bottom flask in an oil bath at about 50 ° C. Then, about 10 parts by weight to about 15 parts by weight of GMA and about 0.1 to about 0.5 part by weight of a reaction-bonding catalyst are further added into the flask, and glycidyl methacrylate (GMA) -bonded L-polylactic acid Can be synthesized. As the reaction-bonding catalysts different from the above-mentioned polymerization catalysts, there are zinc octoate [Zn (II) octoate] and titanium chloride [Ti (II) chloride] And it is effective to use it as a plurality of catalysts.

According to one embodiment of the present invention, glycidyl methacrylate (GMA) is an acrylic monomer having an epoxy group and a vinyl group (double bond) excellent in reactivity and may include one having a chemical structure represented by the following Chemical Formula 1 , But may not be limited to:

[Chemical Formula 1]

.

.

Most of the different acrylic monomers are mostly acrylonitrile (AN), methyl methacrylate (MMA), or vinyl acetate copolymer (VAC), and active groups in the monomer molecule contribute to the synthesis reaction Is limited to vinyl groups. Therefore, when a vinyl group is synthesized on a polymer chain having a different vinyl group, a reactive group is not left in the reaction product. Thus, when a monomer having two functional groups different in reactivity, that is, a monomer having an epoxy group and a monomer having an epoxy group, is reacted to a different polymer in a monomer molecule, a reactive compound in which a reactive epoxy group or a vinyl group remains in the reactant can be obtained. An epoxy resin refers to an oligomeric compound having two or more epoxy groups in one molecule. The open epoxy group of the epoxy resin is subjected to a termination reaction with the methyl group of the L-poly lactic acid. The epoxy resin is excellent in heat resistance, chemical resistance, solvent resistance, abrasion resistance, electrical and mechanical properties, and is used in various fields such as coating, electrical insulation, laminated structure, liver and adhesive. Glycidyl methacrylate (GMA), in which an acrylic group having a double bond is introduced into an epoxy resin used for various purposes, is one kind of acrylic resin monomer and has excellent flexibility and heat resistance and is used in various copolymers.

According to one embodiment of the present invention, glycidyl methacrylate (GMA) has two functional groups in the molecule, a double bond (vinyl group) and an epoxy group, so that the glycidyl methacrylate is easy to synthesize with a different polymer. . To increase the molecular weight of the GMA-linked L-polylactic acid, about 0.1 part by weight to about 1 part by weight of a polymerization solvent, about 0.1 part by weight to about 1 part by weight of 2,2-azobis-isobutyronitrile [2,2 -azobis-isobutyronityronitrile: AIBN], and about 10 parts by weight to about 15 parts by weight of GMA are further added to increase the molecular weight of the L-poly lactic acid to which GMA is coupled. The polymerization solvent used in the present invention may be, but not limited to, methyl acetate, ethyl acetate, or butyl acetate. In order to improve the flexibility and heat resistance of the film, the molecular weight of L-poly lactic acid should be high and a method of bonding L-poly lactic acid to GMA can be used. Further, a method of increasing the molecular weight of L-poly lactic acid using a solid state polymerization method, which is a conventional technique, can also be used.

The glycidyl methacrylate (GMA) -bonded L-polylactic acid having undergone the above reaction is slowly dissolved in chloroform at room temperature, and excess ethanol is added to precipitate to remove unreacted monomers. And sufficiently dried in a vacuum oven at about 50 캜 for about 24 hours to obtain L-poly lactic acid having a copolymer of GMA or GMA. Melting temperature of the GMA is combined L- polylactic acid (T _m) is the number average molecular weight (M _n) from about 180 to about 200 ℃ ℃, may be an approximately 50,000 g / mol to about 100,000 g / mol, this first . If the melting temperature is less than about 180 ° C, improvement in heat resistance of the film can not be expected. If the reaction temperature is increased to more than about 200 ° C or the reaction time is prolonged, yellowing due to thermal decomposition may occur. The flexibility of the film deteriorates and is not applicable to the present application.

According to one embodiment of the present invention, the tan δ (δ = loss Young's modulus / storage modulus) of the polyester film is about 2.5 to about 3.5, and the glass transition temperature (T _g ) measured at a vibration condition of 1 Hz is about 70 To about 75 < 0 > C. And the tanδ is 2.5 or more, when the glass transition temperature (T _g) values of about 75 ℃ or less to determine that the flexibility of the film, and wherein the tanδ is less than 2.5, the glass transition temperature (T _g) When the value exceeds about 75 캜, the film is stiff and can not be used for construction interior materials as described herein.

According to one embodiment of the invention, at least about 80 parts by weight of the L-poly lactic acid bound to the GMA and about 1 to about 15 parts by weight of D-polylactic acid, residual inorganic particles, Extruded, and film-formed at a temperature of about 220 DEG C to about 260 DEG C to form an unstretched film having a thickness of about 100 mu m to about 500 mu m, Can be manufactured. The inorganic particles used in the present invention may be selected from the group consisting of silica, calcium carbonate, and titanium dioxide. The functional additive may be selected from the group consisting of a flame retardant, a brightener, a foaming agent, and a charge control agent. And all known inorganic particles and functional additives may be used, but the present invention is not limited thereto.

According to one embodiment of the present invention, the non-extensible film forming apparatus applicable to the present invention for use as an architectural interior material includes a triangle belt method, a polising roll method, and the like, This may be the case with all technologies that can be shaped into shapes.

According to one embodiment of the present invention, a film having improved heat resistance and flexibility according to the present invention can be used for architectural interior materials such as wallpaper and flooring.

Hereinafter, the present invention will be described in more detail by way of examples, but the present invention is not limited thereto.

[ Example ]

Various performance evaluations of the films prepared in this example and the comparative example were carried out in the following manner.

(1) Heat resistance

L- heat resistance of polylactic acid was evaluated in the melting temperature (T _m) value of differential scanning calorimetry: using (Differential Scanning Calorimetry DSC, Exstar 6000 , Seiko, Japan) to determine the melting temperature (T _m). It was evaluated that the higher the melting temperature (T _m ), the better the heat resistance.

(2) flexibility

The flexibility of the film was evaluated by the values of tan δ (δ = loss Young 's modulus / storage modulus) and glass transition temperature (T _g ) measured at 1 Hz vibration condition. The specimen was fabricated with dimensions of 10 ㎝ × 10 ㎝ And measured using a dynamic mechanical analyzer (DMA, SS610, Seiko Exstar, Japan). It was evaluated that the higher the tan delta value and the lower the glass transition temperature (T _g ), the better the flexibility of the film.

(3) a number average molecular weight (M _n)

The number average molecular weight of the synthesized poly (lactic acid) L- (M _n) was measured using a Gel-Chromatography (GPC, 1000s, Agilent, USA).

(4) Film thickness

The thickness of the prepared film was measured using a film thickness meter (No.219081, Withlab, Korea), and after 12 measurements, it was determined as a mean of 10 times excluding the maximum and minimum values.

< Example  One>

50 g of L-lactide dried in a vacuum oven at 50 캜 for 24 hours or more in a 1,000 mL round bottom flask, 0.15 g of lauryl alcohol as an initiator, 0.18 g of tin octoate [Sn (II) octoate ] Were added, and the mixture was polymerized at 140 ° C. 10 g of GMA and 0.3 g of zinc octoate [Zn (II) octoate] were further added thereto. In order to increase the molecular weight of the L-polylactic acid to which GMA was coupled, 10 g of GMA was further added with 0.2 g of butyl acetate and 0.3 g of AIBN, and the coupling reaction was terminated. The number-average molecular weight (M _n ) of the GMA-coupled L-poly lactic acid was 75,000 g / mol and the melting temperature (T _m ) was 198 ° C. tanδ was 2.97, and the glass transition temperature (T _g) was 73.3 ℃.

88 parts by weight of the L-polylactic acid to which GMA was bonded, 5 parts by weight of D-polylactic acid, 5 parts by weight of silica, and 2 parts by weight of a flame retardant were added, and a non- The unleaded film prepared as described above was excellent in heat resistance and flexibility and was used as a wallpaper material.

1 is a ¹³ C-NMR spectrum showing the chemical structure of glycidyl methacrylate (GMA) -bonded L-polylactic acid according to Example 1, and FIG. 2 is a graph showing the chemical structure of glycidyl methacrylate (GMA) coupled L-polylactic acid according to the present embodiment, and FIG. 3 is a graph showing the results of measurement of dynamic mechanical analysis (DMA) It is a photograph of wallpaper produced using material.

< Example  2 to 5 and Comparative Example  1 to 5>

An unoriented film was produced in the same manner as in Example 1 while changing the synthesis conditions of Examples 2 to 5 and Comparative Examples 1 to 5 described in the following Table 1. The properties of each film prepared in the following Table 1 (The physical properties of the film shown in Table 1 below are values of films made of L-polylactic acid to which GMA is bound).

[Table 1]

As shown in Table 1, the number-average molecular weight (M _n ) of the L-poly lactic acid to which the GMA was bonded was 75,000 g / mol, the melting temperature (T _m ) was 198 ° C., the tan δ was 2.97, (T _g ) was 73.3 캜. As a comparative example, the number average molecular weight (M _n ) of the poly (lactic acid) prepared in the same manner as in Example 1 was 190,000 g / mol, the melting temperature (T _m ) was 165 ° C, Was 1.56 and the glass transition temperature (T _g ) was 78.0 ° C. As the examples of the L-polylactic acid to which the GMA was bonded, it was confirmed that the melting temperature, tan δ value, and glass transition temperature (T _g ) of Example 1 were higher than those of the Comparative Example without GMA bonding, Heat resistance and flexibility were superior to those of Comparative Examples not bonded. That is, the higher the melting temperature (T _m ), the better the heat resistance, the higher the tan δ value, and the lower the glass transition temperature (T _g ), the better the flexibility.

It will be understood by those of ordinary skill in the art that the foregoing description of the embodiments is for illustrative purposes and that those skilled in the art can easily modify the invention without departing from the spirit or essential characteristics thereof. It is therefore to be understood that the above-described embodiments are illustrative in all aspects and not restrictive. For example, each component described as a single entity may be distributed and implemented, and components described as being distributed may also be implemented in a combined form.

The scope of the present invention is defined by the appended claims rather than the detailed description, and all changes or modifications derived from the meaning and scope of the claims and their equivalents should be interpreted as being included in the scope of the present invention .

Claims (20)

A polyester resin prepared by mixing L-polylactic acid with glycidyl methacrylate (GMA) and D-polylactic acid,
The geurisi methacrylate (GMA) is combined L- polylactic acid is of 180 ℃ to 200 ℃ melting temperature of _{(T m), 50,000 g /} mol to 100,000 g / mol that has an average molecular weight (M _n) sign,
Lead-free polyester film.
The method according to claim 1,
Wherein the L-poly lactic acid comprises at least 80 parts by weight, and the D-poly lactic acid comprises 1 part by weight to 15 parts by weight.
delete delete delete Synthesizing L-poly lactic acid to which glycidyl methacrylate (GMA) is bonded; And
Preparing a film comprising a polyester resin obtained by mixing D-polylactic acid with L-polylactic acid to which glycidyl methacrylate (GMA) is bonded;
/ RTI &gt;
The geurisi methacrylate (GMA) is combined L- polylactic acid is of 180 ℃ to 200 ℃ melting temperature of _{(T m), 50,000 g /} mol to 100,000 g / mol that has an average molecular weight (M _n) sign,
A method for producing a non-oriented polyester film.
delete The method according to claim 6,
Wherein the L-poly lactic acid is obtained by mixing and polymerizing L-lactide, an initiator, and a polymerization catalyst as monomers.
9. The method of claim 8,
Wherein the initiator is selected from the group consisting of lauryl alcohol, hetero-bimetallic alkoxide, hetero-bimetallic aryloxide, and potassium benzoate. By weight based on the total weight of the polyester film.
9. The method of claim 8,
Wherein the polymerization catalyst comprises tin octoate [Sn (II) octoate] or aluminum octoate [Al (III) octoate].
The method according to claim 6,
Wherein the step of synthesizing glycidyl methacrylate (GMA) -containing L-polylactic acid comprises adding LMA and a reaction-coupling catalyst to L-poly lactic acid and reacting. &Lt; / RTI &gt;
12. The method of claim 11,
Wherein the reaction-bonding catalyst comprises zinc octoate [Zn (II) octoate] or titanium chloride [Ti (II) chloride].
12. The method of claim 11,
A polymerization solvent, 2,2-azobis-isobutyronitrile (AIBN), and GMA are further added to L-polylactic acid to which glycidyl methacrylate (GMA) is bonded to react the L- And further comprising increasing the molecular weight of the non-oriented polyester film.
delete The method according to claim 6,
The step of preparing a film containing the polyester-based resin may include the steps of: adding D-poly lactic acid, inorganic particles, and functional additives to L-poly lactic acid to which glycidyl methacrylate (GMA) Wherein the polyester film is a polyester film.
16. The method of claim 15,
Wherein at least 80 parts by weight of the glycidyl methacrylate (GMA) is combined with L-polylactic acid, and 1 part by weight to 15 parts by weight of D-polylactic acid.
16. The method of claim 15,
Wherein the inorganic particles comprise a material selected from the group consisting of silica, calcium carbonate, and titanium dioxide.
16. The method of claim 15,
Wherein the functional additive comprises a material selected from the group consisting of a flame retardant, a brightener, a foaming agent, and an antistatic agent.
16. The method of claim 15,
Polylactic acid, inorganic particles, and a functional additive in addition to the L-poly lactic acid, followed by drying, melting, extrusion, and molding. .
A film according to claim 1 or 2, comprising a film according to any one of claims 1 to 3.

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