KR20160079770A - Polylactic acid blended non-woven fabric having improved flexibility and method for preparing same - Google Patents

Abstract

The present invention relates to a polylactic acid blend nonwoven fabric having improved flexibility and a method for producing the same, wherein the polylactic acid blend nonwoven fabric having improved flexibility according to the present invention is a nonwoven fabric prepared by spinning polylactic acid and polypropylene blend, The weight of the polylactic acid is 10 to 80% by weight, the weight of the polypropylene is 10 to 89% by weight, the weight of the dispersant is 1 to 7% by weight, the weight of the softener is 1 to 3% by weight And the total weight of the nonwoven fabric is 10 to 100 gsm.
The polylactic acid blend nonwoven fabric having improved flexibility according to the present invention and the method of manufacturing the same having the above-described structure and the method of manufacturing the same have improved flexibility by lowering the friction coefficient of the surface of the nonwoven fabric by adding a specific softener at a certain ratio, The polylactic acid and the polypropylene are uniformly dispersed in the polylactic acid and the polylactic acid and the polypropylene are uniformly controlled in the mixing and spinning processes using a dispersant. So as to be spinnable and nonwoven fabric, thereby improving the productivity and solving the above-mentioned conventional problems.

Description

TECHNICAL FIELD [0001] The present invention relates to a polylactic acid blend nonwoven fabric having improved flexibility and a method for producing the same. [0002] Polylactic acid blend non-

The present invention relates to a polylactic acid blend nonwoven fabric having improved flexibility and a method for producing the same. More particularly, the present invention relates to a blend of polylactic acid and polypropylene using a dispersant specific to polylactic acid having excellent biodegradability, The present invention relates to a polylactic acid blend nonwoven fabric which can be easily reduced in carbon emission and which has improved flexibility and which can improve the quality of a product by lowering the friction coefficient of the nonwoven fabric surface and improving flexibility.

Polymer materials derived from plants that can be regenerated from biomass due to environmental pollution and soaring petroleum prices due to the exponential increase of waste polymers due to technological advancement and quality of life are attracting attention . In particular, biodegradable polymers that can be decomposed spontaneously in soil or landfill are attracting attention as environmental pollution becomes worse in recent years.

Among these polymers, aliphatic polyester polymers have been studied extensively as biodegradable polymers because of their excellent processability and easy control of their decomposition properties. Among them, polylactic acid (PLA) And applications to general plastic such as food packaging materials, containers and electronic product cases have been expanded. Until now, the main use of polylactic acid resin has been generally used for disposable products using biodegradable properties of polylactic acid, such as food containers, wraps, and films.

In recent years, studies have been conducted to blend polylactic acid and polypropylene. When the polylactic acid is blended with polypropylene, the use amount of the general-purpose resin derived from a petroleum raw material can be suppressed. As a result, The use amount of the raw material can be suppressed, and the generation of carbon dioxide gas at the time of disposal and the heat of combustion can be lowered, and thus it has been attracting attention as a method for reducing environmental burden. Especially, polypropylene which is most used in disposable hygiene products, the amount of carbon dioxide generated in burning 1 ton of polypropylene is 3,200 kg, whereas the amount of polylactic acid is 1,830 kg, which is only 57% of polypropylene It can be said that it is in a very favorable position.

However, in spite of the above-mentioned advantageous aspect, when the polylactic acid and the polypropylene are blended, the dispersibility of the polylactic acid and the polypropylene is not sufficient and the heat resistance and the mechanical properties can not be improved. A method of blending polylactic acid with a thermoplastic resin other than polylactic acid and a method of blending polylactic acid with polymethylmethacrylate have been disclosed. However, these methods are not suitable for polylactic acid and polypropylene There has been a limit to improve the compatibility and in addition, when blending polylactic acid with a general-purpose resin and spinning, problems such as a serious pressure rise of the die and a yarn breaking phenomenon may occur depending on the manufacturing process, Commercial use between lactic acid and general-purpose resin It means that the nonwoven fabric can not be manufactured unless the spinning process is supported even if the properties are good. Therefore, in order to solve the above-mentioned problem, researches continue. Korean Unexamined Patent Application Publication No. 2002-0029110 proposes a disposable absorbent product having a biodegradable nonwoven material having fluid treatment properties. And polylactic acid and polypropylene and a compatibilizing agent. Korean Patent Laid-Open Publication No. 2002-0063063 discloses a method for producing biodegradable polylactic acid by blend spinning of polylactic acid Wherein the weight of the polylactic acid in the total weight of the polymer blend for blending is 10 to 80% by weight, the weight of the polypropylene is 10 to 10% by weight, To 89% by weight, the weight of the dispersing agent is 1 to 10% by weight %, And the total weight of the nonwoven fabric is 10 to 100 gsm. The nonwoven fabric having biodegradability and low carbon emission characteristics by blend spinning of polylactic acid and a method for producing the nonwoven fabric are disclosed.

However, the above-mentioned conventional polylactic acid blend nonwoven fabrics mainly focus on improvement of radioactivity due to resin mixing property, and little or no improvement in the mechanical or physical properties of these blend nonwoven fabrics is recognized. Therefore, It is absent.

SUMMARY OF THE INVENTION Accordingly, the present invention has been made in view of the above-mentioned technical circumstances, and it is a main object of the present invention to provide a polylactic acid composition which is excellent in compatibility between a polylactic acid and a general- The present invention is to provide a polylactic acid blend nonwoven fabric which is excellent in flexibility as a physical property of the nonwoven fabric and can be used for various purposes.

It is another object of the present invention to provide a method for manufacturing a nonwoven fabric having excellent physical properties as described above more easily.

The present invention may also be directed to accomplish these and other objects, which can be easily derived by those skilled in the art from the overall description of the present specification, in addition to the above-mentioned and obvious objects.

It is an object of the present invention to provide a method for producing polylactic acid by dispersing polylactic acid in a polypropylene uniformly while applying a specific dispersant for improving compatibility with polylactic acid and polypropylene, The flexibility of the produced nonwoven fabric can be remarkably improved while being excellent in radioactivity of the nonwoven fabric.

To achieve the above object, the present invention provides a polylactic acid blend nonwoven fabric having improved flexibility;

In a nonwoven fabric produced by polylactic acid and polypropylene blend spinning,

Wherein the weight of the polylactic acid is 10 to 80 wt%, the weight of the polypropylene is 10 to 89 wt%, the weight of the dispersant is 1 to 7 wt%, the weight of the softener is 1 to 10 wt% 3 wt%, and the total weight of the nonwoven fabric is 10 to 100 gsm.

According to another aspect of the present invention, the softening agent is an erucamide softening agent.

According to another embodiment of the present invention, the erucamide is a stearyl erucamide or an erucyl erucamide.

According to another aspect of the present invention, the dispersing agent comprises a hydrophilic part which is miscible with the polylactic acid polymer and a hydrophobic part which is miscible with the polypropylene polymer.

According to another aspect of the present invention, there is provided a method for producing a polylactic acid blend nonwoven fabric having improved flexibility, comprising:

A method for producing a nonwoven fabric by spinning a polylactic acid and a polypropylene blend,

Wherein the weight of the polylactic acid is 10 to 80 wt%, the weight of the polypropylene is 10 to 89 wt%, the weight of the dispersant is 1 to 7 wt%, the weight of the softener is 1 to 7 wt% 3% by weight of polylactic acid and polypropylene as a substantially continuous phase are dispersed in the polypropylene resin through the dispersing agent so that the polylactic acid is evenly mixed and dispersed to form a dry mixture of the thermoplastic composition;

Effectively mixing the polylactic acid polymer, the polypropylene polymer and the dispersing agent uniformly to form a homogeneous dry mixture by agitating, agitating or otherwise blending the dry mixture of thermoplastic compositions;

Melt blending the dry mixture in an extruder to effectively and uniformly mix the polylactic acid polymer, the polypropylene polymer and the dispersant to form a homogeneous molten mixture; And

Forming a web by spinning the molten mixture to form a nonwoven fabric by thermocompression;

The total weight of the nonwoven fabric is 10 to 100 gsm.

According to another embodiment of the present invention, the polylactic acid is characterized by using polylactic acid having a melt flow index (MI: Melt Index, 210 ° C) of 15 to 30 g / 10 min.

The polylactic acid blend nonwoven fabric having improved flexibility according to the present invention and the method of manufacturing the same having the above-described structure and the method of manufacturing the same have improved flexibility by lowering the friction coefficient of the surface of the nonwoven fabric by adding a specific softener at a certain ratio, The polylactic acid and the polypropylene are uniformly dispersed in the polylactic acid and the polylactic acid and the polypropylene are uniformly controlled in the mixing and spinning processes using a dispersant. So as to be spinnable and nonwoven fabric, thereby improving the productivity and solving the above-mentioned conventional problems.

Best Mode for Carrying Out the Invention

Hereinafter, the present invention will be described in more detail with reference to the preferred embodiments.

Prior to describing the present invention in detail, the above-mentioned polylactic acid used throughout the specification of the present invention is defined first, polylactic acid is generally prepared by polymerization of lactic acid or lactide, The term "polylactic acid" is intended to refer to a polymer produced by the polymerization of lactic acid or lactide. Any known polymerization method, for example, polycondensation or ring-opening polymerization, can be used to polymerize the lactic acid. In the polycondensation process, for example, L-lactic acid, D-lactic acid or a mixture thereof is applied directly to the dehydration-polycondensation. In ring-opening polymerization processes, the lactide, a cyclic dimer of lactic acid, is applied to the polymerization with the aid of polymerization regulators and catalysts. Lactides may include L-lactide, D-lactide and DL-lactide (also referred to as condensates of meso-lactide, L-lactic acid and D-lactic acid). Each of the lactides (i.e., L-lactide, D-lactide and DL-lactide) is a dimer. That is, they consist of two lactic acid units. Because of its chiral center, lactic acid has two different stereochemically isomeric forms, namely the R and S isomeric forms. The D-lactide comprises two R-isomers, the L-lactide comprises two S-isomers, and the meso-lactide comprises R-isomers and S-isomers. The different isomers may be mixed and, if necessary, polymerized to obtain a polylactic acid having any desired composition and crystallinity as described in more detail below. In addition, the molecular weight of the polylactic acid can be increased by using a small amount of a chain extender (for example, a diisocyanate compound, an epoxy compound or an acid anhydride as described below). Suitably, the weight average molecular weight of the polylactic acid is from about 60,000 to about 1,000,000.

Suitable polylactic acid polymers that may be used in the present invention include, but are not limited to, those commercially available under the name Natureworks (Mineral Works < (R) >) from Minneapolis, Minn. Available. Other suitable polylactic acid polymers are commercially available from BIOMER (TM) L9000 or Mitsui Chemical (LACEA (TM)) from Biomer, Inc. of Krailling, Germany. It is possible. Another suitable polylactic acid is disclosed in U.S. Patent Nos. 4,797,468; 5,470,944; 5,770,682; 5,821, 327; 5,880,254; And 6,326,458 may be used.

In addition, the melt flow index of the polylactic acid can be determined by ASTM Test Method D1238-A, which can be forced through an extrusion flow meter orifice (diameter 0.0825 inch) when applied to a load of 2160 grams at 10 minutes at any temperature E < / RTI > The polylactic acid is also typically at a melting point of from about 100 占 폚 to about 240 占 폚, in some embodiments from about 120 占 폚 to about 220 占 폚, and in some embodiments, from about 140 占 폚 to about 200 占 폚. These low melting point polylactic acid are useful in that they are biodegraded at high speed. The glass transition temperature ("Tg") of the polylactic acid is also relatively low to improve the solubility and processability of the polymer. For example, the Tg may be about 80 캜 or less, in some embodiments about 70 캜 or less, in some embodiments about 65 캜 or less. As discussed in more detail below, the melting point and the glass transition temperature can both be determined using a differential scanning calorimeter ("DSC") in accordance with ASTM D-3417.

The above-mentioned polylactic acid polymer is generally produced by polymerization reaction of lactic acid. However, one of ordinary skill in the art will recognize that chemically equivalent materials can also be prepared by polymerization of lactide. For this reason, the term " polylactic acid polymer " as used herein is intended to mean a polymer produced by the polymerization reaction of lactic acid or lactide.

In general, the polylactic acid polymer is preferably present in the thermoplastic composition in an amount effective to produce a thermoplastic composition (e. G., A polypropylene polymer) exhibiting the desired properties. The polylactic acid polymer is generally present in the thermoplastic composition in an amount of from about 10 wt% to about 80 wt%, suitably from about 15 wt% to about 70 wt%, more preferably from about 20 wt% to about 60 wt% Wherein all weight percentages are based on the total weight of the polylactic acid polymer, polypropylene polymer, and dispersant present in the thermoplastic composition. It is important to maintain the compositional ratio of the three components in the thermoplastic composition, since the polypropylene polymer generally needs to be a substantially continuous phase in order for the thermoplastic composition to be substantially radiated to form a nonwoven. The approximate limit of composition ratios can be determined based on the density of the components. The volume of the component is converted to the volume (estimated at 100 g of each component), the volumes of the components are added together to determine the volume of the total thermoplastic composition, and the weight average of the components is calculated so that the thermoplastic composition in which the polylactic acid polymer in the blend occupies most of the volume The approximate minimum ratio of each component required for production can be obtained.

Further, the polypropylene polymer is known in the art as a resin belonging to a polyolefin-based polymer. Any polyolefin, e. G., Spunbond long fibers, which may be made into articles, are considered suitable for use in the present invention. The polypropylene can be high density or low density, and can generally be a straight chain or branched chain polymer. Methods for making polypropylene are known to those of ordinary skill in the art.

Polypropylene as described above is generally naturally hydrophobic. As used herein, the term " hydrophobic " refers to a material having a contact angle of water in air of at least 90 degrees. In contrast, the term " hydrophilic " as used herein refers to a material having a contact angle of water in air of less than 90 degrees. According to the present invention, the contact angle measurements are described in Robert J. Good and Robert J. Stromberg, Ed., In 'Surface and Colloid Science - Experimental Methods', Vol. II, (Plenum Press, 1979), pages 63-70.

Generally, it is generally preferable that both the polylactic acid polymer and the polypropylene can be melt-processed. Therefore, the polylactic acid polymer and polypropylene should have a viscosity of from about 1 gram per 10 minutes to about 200 grams per 10 minutes, suitably from about 10 grams per 10 minutes to about 100 grams per 10 minutes, more preferably from about 20 grams per 10 minutes To about 10 grams per minute. The melt flow rate of the material can be obtained according to ASTM Test Method D1238-E, which is incorporated herein by reference.

It has been found desirable to improve the processability of the polylactic acid polymer and the polypropylene polymer, since the polymers are not chemically identical and are thus somewhat incompatible with each other, which is likely to adversely affect the processing of the mixture of the polymers. For example, polylactic acid polymers and polypropylene polymers are sometimes difficult to manufacture as an essentially homogeneous mixture which is difficult to mix effectively on their own. In general, it has been found desirable to use dispersants to aid in the effective manufacture of polylactic acid polymers and polypropylene polymers and in the processing of single thermoplastic compositions.

Dispersants suitable for use in the present invention generally comprise a hydrophilic moiety that is miscible with the polylactic acid polymer and a hydrophobic moiety that becomes miscible with the polypropylene polymer. These hydrophilic and hydrophobic moieties are generally present in separate blocks and the overall dispersant structure may be a diblock or random block. It is generally preferred that the dispersant act as a plasticizer initially to improve the preparation and processing of the thermoplastic composition. It is then generally preferred that the dispersing agent act as a surfactant by varying the contact angle of water in the air of the processed material in the nonwoven material of the present invention which is a material that has been processed from the thermoplastic composition. The hydrophobic portion of the dispersant can be, but is not limited to, polystyrene. The hydrophilic portion of the dispersant may contain ethylene oxide, ethoxylate, glycols, alcohols or any mixture thereof. The component of the suitable dispersing agent is preferably a styrene-ethylene-butylene-styrene block copolymer component.

It is generally preferred that the dispersant be present in the thermoplastic composition in an amount effective to produce the thermoplastic composition exhibiting the desired properties. In general, a minimum amount of dispersant is required to achieve effective blending and processing with other components in the thermoplastic composition. In general, too much dispersant will result in processing problems of the thermoplastic composition. The dispersant is advantageously present in the thermoplastic composition in an amount of from about 1% to about 7%, preferably from about 1.5% to about 6%, more preferably from about 2% to about 5% , Wherein all weight percentages are based on the total weight of the polylactic acid polymer, polypropylene polymer and dispersant present in the thermoplastic composition.

According to a preferred embodiment of the present invention, 1 to 3% by weight of a softener is mixed, wherein the softener is an erucamide softener of CH ₃ (CH ₂ ) ₇ CH═CH (CH ₂ ) ₁₁ CONH ₂ And examples of the erucamide system include stearyl erucamide and erucyl erucamide.

As described above, the non-woven fabric improved in biodegradability, low carbon emission characteristics and flexibility through blend spinning of the polylactic acid according to the present invention is preferably 1 to 3% by weight. If the content of the softener is less than 1% The effect of reducing the coefficient of friction of the nonwoven fabric is low. However, when the content of the nonwoven fabric is less than 3%, the effect of lowering the coefficient of friction is good.

Although the main components of the thermoplastic composition for making the nonwoven fabric according to the present invention have been described above, the thermoplastic composition is not limited thereto and may include other components that do not adversely affect the desired properties of the resulting nonwoven fabric. Examples of materials that can be used as additional components include pigments, antioxidants, stabilizers, surfactants, waxes, flow promoters, solid solvents, plasticizers, nucleating agents, particulates, and materials added to improve the processability of thermoplastic compositions As shown in FIG. If the additional ingredients are included in the thermoplastic composition, the additional ingredients advantageously are used in amounts of less than about 5% by weight, more advantageously less than about 3% by weight, suitably less than about 1% by weight Where all weight percentages are based on the total weight of the polylactic acid polymer, polypropylene, dispersant, and softener present in the thermoplastic composition.

The thermoplastic compositions used in the present invention are generally obtained in the form of a mixture of polylactic acid polymers, polypropylene polymers, dispersants and softeners and any additional components. The polylactic acid polymer forms a substantially discontinuous phase enclosed within the continuous phase of the substantially polypropylene polymer. In order to achieve the desired properties for the thermoplastic composition, it is preferred that the polylactic acid polymer, the polypropylene polymer, the dispersant and the softener remain substantially unreacted with each other. For this reason, each of the polylactic acid polymer, polypropylene, dispersant and softener remains as separate components of the thermoplastic composition. In addition, the polypropylene polymer forms a substantially continuous phase, and the polylactic acid polymer forms a substantially discontinuous phase, wherein the polypropylene polymer continuous phase substantially encloses the polylactic acid polymer within its structure.

In one embodiment of the present invention, the polylactic acid polymer, the polypropylene polymer, the dispersant and the softening agent are dry mixed together to form a dry mixture of the thermoplastic composition, and then the dry mixture of the thermoplastic composition is advantageously stirred, stirred, To effectively uniformly mix the polylactic acid polymer, the polypropylene polymer, the dispersant, and the softener to form an essentially homogeneous dry mixture. The dry mixture is then melt-blended, for example, in an extruder to effectively mix the polylactic acid polymer, polypropylene polymer and dispersant uniformly to form an essentially homogeneous molten mixture.

A method for producing a multicomponent fiber produced from the thermoplastic composition described above will be described. Melt spinning of the polymer involves the production of continuous filaments, such as spunbond or meltblown, and the construction of non-continuous filaments, such as staples and short-cut fibers. To produce spunbond or meltblown fibers, a thermoplastic composition is typically extruded and fed to a dispensing system wherein the thermoplastic composition is introduced into the spinneret plate. The spun fibers are then cooled, solidified, stretched into an aerodynamic system and molded into a conventional nonwoven. On the other hand, to produce short cut or staple fibers, rather than being molded into a direct nonwoven structure, the spun fibers are allowed to cool, solidify, and generally stretch to an intermediate filament diameter with a mechanical roll system and collect. The fiber is then 'cold stretched' to the desired final fiber diameter at a temperature below its softening temperature, crimped or patterned, and cut to the desired fiber diameter.

The cooling process for stretching the extruded thermoplastic composition and / or fibers is preferably a cooling means that does not include water, since the composition comprises water-soluble components. Cooling is generally accomplished by blowing air below the ambient or ambient temperature onto the extruded polymer. At this time, the cooling temperature is generally preferably between 10 and 20 ° C, more preferably between 13 and 18 ° C.

The polylactic acid material often undergoes thermal contraction during the thermal processing of the second half of the process. Heat shrinkage is mainly due to thermally induced chain relaxation of the polymer segments in the amorphous phase and incomplete crystalline phase. In order to overcome this problem, it is generally desirable to maximize the crystallization of the material prior to the bonding step so that the thermal energy melts directly rather than allowing chain relaxation and rearrangement of incomplete crystalline structures. A typical solution to this problem is to apply heat curing treatment to the material. For this reason, when the produced material, such as fibers, reaches the binding roll and undergoes a heat curing treatment, the fibers do not substantially shrink because they are already completely or very much oriented. The present invention eliminates the need for this additional processing step due to the shape of the multicomponent fiber. Polypropylene as described above generally provides a reinforcing structure that minimizes the predicted thermal shrinkage of the polylactic acid.

As described above, the method for producing a nonwoven fabric by spinning of polylactic acid and polypropylene blend according to the present invention is characterized in that polylactic acid and polypropylene as a substantially continuous phase are dispersed in a polylactic acid by uniformly dispersing polylactic acid in a polypropylene resin But it is possible to prepare a nonwoven fabric which can be easily processed into a nonwoven structure exhibiting effective mechanical properties and liquid treatment characteristics of the fibers.

According to a preferred embodiment of the present invention, in a method for producing a nonwoven fabric by polylactic acid / polypropylene blend spinning, polylactic acid and a dispersant are extruded at a constant ratio together with polypropylene using a dosing system, , Wherein the loading rate of the polylactic acid is advantageously from about 10% to about 80% by weight, suitably from about 15% to about 70% by weight, more preferably from about 20% % To about 60% by weight. If the polylactic acid feed rate is less than 10% by weight, the carbon reduction efficiency is low. If the polylactic acid feed rate is more than 90% by weight, there is a problem in that the amount of the sub- It is not preferable.

The polylactic acid / polypropylene blend mixture containing the dispersant is a thermoplastic or radiation polymer. As used herein, the term "mixture" includes a heterogeneous mixture of two or more physically discrete polymers, such as a homogeneous mixture of two or more polymers or a bi-comonent. Next, the polylactic acid / polypropylene blend mixture containing the dispersing agent is spun, the spun filaments are solidified by the cooling air injected through the honeycomb-shaped chamber and the pressure of the air blowing from the upper part and the air sucked from the lower part of the conveyor belt And is laminated on the conveyor belt at a constant weight to form a web. The web can comprise a single layer (meltblown layer M, or spunbond layer S), a composite of two layers (SS or SM) or a composite layer of three or more layers (SMS, SMMS, SSMMS, SSMMSS web). Certain webs can vary greatly in weight (gsm) and this weight change can be adjusted by the amount of stratification and the velocity of the conveyed belt. Finally, the integrated web thermally couples to impart mechanical properties and shape stability. Although the adhesive area is not limited, the configuration of the calender roll is normally composed of an emboss roll surface having an adhesive area of 10 to 20% by weight, and the other is a smooth surface roll The multi-layered web is passed through the roll and sheeted. The nonwoven web of long fibers may be joined by any process well known in the art, such as a process selected from the group consisting of chemical bonding (resin bonding), water binding and needle punching as well as thermal bonding as described above in the bonding of the integrated web. Thereby forming a nonwoven fabric. Preferably, thermal bonding can be employed.

DETAILED DESCRIPTION OF THE INVENTION

Hereinafter, the nonwoven fabric of the present invention will be described in detail by way of examples. It will be apparent to those skilled in the art that these embodiments are provided by way of illustration only for the purpose of more particularly illustrating the present invention and that the scope of the present invention is not limited by these embodiments .

In the following examples and comparative examples, fibers were prepared using various amounts of polylactic acid, polypropylene, dispersant, and softening agent, and these polylactic acid polymers (PLA) were obtained from Natureworks, Minneapolis, Minn. The polypropylene polymer (PP) was obtained from Honam Petrochemical under the trade name SFR-171H and the melt index (MI) was 35 g / 10 min. The melt flow index (MI) 10 minutes and had a melting temperature of about 160 DEG C and a dispersant was obtained from JSR Corporation of Tsukishi Seisakusho, Japan under the trade name of DYNARON 8630P, ≪ RTI ID = 0.0 > polylactic acid < / RTI > and a dispersant were weighed using a dosing system to meter the raw materials, And the radiated filaments are solidified by the cooling air injected through the honeycomb-shaped chamber, and the pressure of the air blowing from the upper part and the air sucked from the lower part of the conveyor belt Followed by laminating on a conveyor belt at a constant weight to form a web, followed by thermal bonding to produce a nonwoven fabric.

Example 1

20% by weight of polylactic acid, 3% by weight of dispersant, 1% by weight of softener and 76% by weight of polypropylene resin were melt-spun into fibers and drawn on a porous conveyor belt to produce polylactic acid / polypropylene nonwoven fabric having a basis weight of 40 gsm The properties of the fabricated nonwoven fabric were measured and are shown in Table 1 below.

Example 2

A nonwoven fabric was prepared in the same manner as in Example 1 except that 20% by weight of polylactic acid, 3% by weight of dispersant and 3% by weight of softener and 74% by weight of polypropylene resin were added, Respectively.

Comparative Example 1

A nonwoven fabric was prepared in the same manner as in Example 1, except that 20 wt% of polylactic acid, 3 wt% of dispersant, and 77 wt% of polypropylene resin were added, and physical properties of the resultant nonwoven fabric were measured and shown in Table 1 .

Comparative Example 2

A nonwoven fabric was prepared in the same manner as in Example 1 except that 20 wt% of polylactic acid, 3 wt% of dispersant, 0.5 wt% of softener, and 76.5 wt% of polypropylene resin were added, Table 1 shows the results.

Comparative Example 3

A nonwoven fabric was prepared in the same manner as in Example 1 except that 20% by weight of polylactic acid, 3% by weight of dispersant, 5% by weight of softener and 72% by weight of polypropylene resin were added, Table 1 shows the results.

Experimental Example

The properties of the nonwoven fabric prepared according to the above Examples and Comparative Examples were evaluated as follows.

(1) Weight per unit area (weight: g / m 2): Measured according to the method of ASTM D 3776-1985.

(2) Tensile strength: The maximum load was determined by pulling a test piece having a test piece width of 5 cm and an interval of 10 cm at a tensile speed of 500 mm / min by the KSK 0520 method using a tensile-strength steel instrument measuring device.

(3) Tensile elongation: The elongation at the maximum elongation measured by the method of (2) above was determined.

(4) Flexibility (coefficient of friction): When the friction coefficient measuring device is operated using the method of KS M 3009, the measuring device automatically tilts and the plate slides down and stops when the sensor is pressed. At this time, the value of the angle in the stop state is converted.

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. It will be apparent to those skilled in the art that various modifications and variations are possible within the spirit and scope of the present invention, and it is therefore intended that such variations and modifications fall within the scope of the appended claims.

Claims (6)

In a nonwoven fabric produced by polylactic acid and polypropylene blend spinning,
Wherein the weight of the polylactic acid is 10 to 80 wt%, the weight of the polypropylene is 10 to 89 wt%, the weight of the dispersant is 1 to 7 wt%, the weight of the softener is 1 to 10 wt% 3% by weight, and the total weight of the nonwoven fabric is 10 to 100 gsm. The polylactic acid blend nonwoven fabric according to claim 1, wherein the softening agent is an erucamide type softening agent. The polylactic acid blend nonwoven fabric according to claim 2, wherein the erucamide is stearyl erucamide or erucyl erucamide. The polylactic acid blend nonwoven fabric according to claim 1, wherein the dispersant comprises a hydrophilic part which is miscible with the polylactic acid polymer and a hydrophobic part which is miscible with the polypropylene polymer. A method for producing a nonwoven fabric by spinning a polylactic acid and a polypropylene blend,
Wherein the weight of the polylactic acid is 10 to 80 wt%, the weight of the polypropylene is 10 to 89 wt%, the weight of the dispersant is 1 to 7 wt%, the weight of the softener is 1 to 7 wt% 3% by weight of polylactic acid and polypropylene as a substantially continuous phase are dispersed in the polypropylene resin through the dispersing agent so that the polylactic acid is evenly mixed and dispersed to form a dry mixture of the thermoplastic composition;
Effectively mixing the polylactic acid polymer, the polypropylene polymer and the dispersing agent uniformly to form a homogeneous dry mixture by agitating, agitating or otherwise blending the dry mixture of thermoplastic compositions;
Melt blending the dry mixture in an extruder to effectively and uniformly mix the polylactic acid polymer, the polypropylene polymer and the dispersant to form a homogeneous molten mixture; And
Forming a web by spinning the molten mixture to form a nonwoven fabric by thermocompression;
Wherein the total weight of the nonwoven fabric is 10 to 100 gsm. ≪ RTI ID = 0.0 > 11. < / RTI > The polylactic acid blend nonwoven fabric according to claim 5, wherein the polylactic acid is polylactic acid having a melt flow index (MI: Melt Index, 210 ° C) of 15 to 30 g / 10 min.