KR101221211B1 - Nonwoven fabric having biodegradable and low carbon-discharging property and preparing method thereof - Google Patents

Abstract

The present invention relates to a non-woven fabric having a biodegradability and low carbon emission characteristics through the blend spinning of polylactic acid, and a method for manufacturing the same, wherein the non-woven fabric having a biodegradability and low carbon emission characteristics through the blend spinning of the polylactic acid of the present invention is poly In the nonwoven fabric produced by blending lactic acid with polypropylene, the weight of polylactic acid is 10 to 80% by weight, the weight of polypropylene is 10 to 89% by weight, and the weight of the dispersant in the total weight of the polymer mixture for blending. Is composed of 1 to 10% by weight, characterized in that the total weight of the nonwoven fabric is 10 to 100gsm.
The present invention constituted as described above is a specific control of the manufacturing process conditions during mixing and spinning by using a dispersant specific to the polylactic acid / polypropylene blend to uniformly mix the polylactic acid and polypropylene spinning and non-woven fabric, Similar to or superior to the nonwoven fabric spun with conventional polypropylene, the nonwoven fabric produced is a useful invention that is also advantageous in reducing carbon emissions.

Description

Nonwoven fabric having biodegradable and low carbon emission characteristics through blend spinning of polylactic acid and non-woven fabric and its manufacturing method {Nonwoven fabric having biodegradable and low carbon-discharging property and preparing method

The present invention relates to a non-woven fabric having biodegradability and low carbon emission characteristics through blend spinning of polylactic acid, and more particularly, to a non-woven fabric by blending polylactic acid and polypropylene using specific dispersants and spinning them under specific conditions. The present invention relates to a nonwoven fabric having a biodegradable and low carbon emission property through blend spinning of polylactic acid, which is easy to reduce carbon emission and can be used in a disposable absorbent product intended for absorption of a fluid such as a body fluid. .

Due to the development of technology and the improvement of quality of life, due to the environmental pollution problem caused by the exponential increase of waste polymers and the rise in the price of petroleum, plant-derived polymer materials, which have a low environmental burden and can be recycled from biomass, are attracting attention. . In particular, in recent years, biodegradable polymers that can be naturally decomposed in soil or landfills are in the spotlight as environmental pollution becomes severe.

Among these polymers, aliphatic polyester polymers are the most researched as biodegradable polymers because of their excellent processability and easy control of their decomposition properties. Among them, polylactic acid (PLA) has a market of 100,000 tons worldwide. And the scope of application is expanding to the field where general plastics such as food packaging materials, containers, and electronics cases were used. To date, the main uses of polylactic acid resins have generally been used in disposable products utilizing the biodegradable properties of polylactic acid, such as food containers, wraps, films and the like.

In recent years, research has been conducted on blending polylactic acid and polypropylene. However, when the polylactic acid is blended with polypropylene, the amount of general purpose resin derived from petroleum raw materials can be suppressed. The amount of raw materials used can be suppressed, and the generation of carbon dioxide gas at the time of disposal and the heat of combustion can be lowered, which has attracted much attention as a method for reducing the environmental burden. In particular, polypropylene, the most widely used disposable hygiene product, consumes 3,200kg of carbon dioxide to burn 1 ton of polypropylene, whereas polylactic acid is 1,830kg, which is only 57% of polypropylene. It is in a very advantageous position.

However, in spite of the above advantageous aspects, when blending the polylactic acid and polypropylene, there is a problem in that the dispersibility of the polylactic acid and polypropylene is not sufficient to improve the heat resistance or mechanical properties, and thus this problem is solved. Some solutions have been proposed to solve the problem. For example, as a blend of polylactic acid and a thermoplastic resin other than polylactic acid, the polylactic acid and polymethyl methacrylate are disclosed in Japanese Patent Laid-Open No. 2005-171204. Although a blend with (polymethylmethacrylate) is disclosed, the patented method has limitations in improving compatibility with polylactic acid and incompatible polypropylene.

In addition, in the case of blending and spinning polylactic acid and general-purpose resin, problems such as severe pressure rise of the die and thread breaking occurred due to the manufacturing process, which could not be practically used, even though the compatibility between polylactic acid and general-purpose resin was good. If the spinning manufacturing process is not supported, it means that nonwovens cannot be produced.

Therefore, studies to solve the above problems continue, but the effective solution has not been devised, for example, Korean Patent Publication No. 2002-0029110 is a disposable having a biodegradable nonwoven material having a fluid treatment characteristics In order to provide an absorbent article, the use of a compatibilizer to improve the preparation and processing of thermoplastic compositions and the preparation of fibers using polylactic acid, polypropylene and a compatibilizer are disclosed, but are disclosed in this publication. It is only for the configuration of manufacturing fibers using polylactic acid, polypropylene, and a common compatibilizer, the above-mentioned conventional problem is still not solved, and for the nonwoven fabric production and processing conditions such as specific spinning conditions The above-mentioned conventional door which does not start at all There is a problem that cannot be solved.

Patent Document 1: Japanese Unexamined Patent Publication No. 2005-171204 Patent Document 2: Republic of Korea Patent Publication No. 2002-0029110

Accordingly, the present invention has been made in view of the above-mentioned technical problems, and a main object of the present invention is to improve compatibility between polylactic acid and general-purpose resins, and to control manufacturing process conditions during spinning to provide excellent biodegradability and mechanical properties. While providing a non-woven fabric having a low carbon emission characteristics and biodegradability through blend spinning of polylactic acid, which is advantageous for carbon emissions.

Another object of the present invention is to provide a method for producing a nonwoven fabric having the above characteristics more easily.

The present invention may also be aimed at achieving, in addition to the above-mentioned specific objects, other objects which can be easily derived by those skilled in the art from this and the overall description of the present specification.

The above object of the present invention is achieved by uniformly dispersing polylactic acid in polypropylene by applying a specific dispersant which improves compatibility when blending polylactic acid and polypropylene, and then controlling the manufacturing process conditions during spinning to produce a nonwoven fabric. It became.

Non-woven fabric having a biodegradable and low carbon emission characteristics through the blend spinning of the polylactic acid of the present invention for achieving the above object;

In nonwoven fabrics made through polylactic acid and polypropylene blend spinning,

The weight of the polylactic acid in the total weight of the polymer mixture for blending is 10 to 80% by weight, the weight of polypropylene is 10 to 89% by weight, the weight of the dispersant is composed of 1 to 10% by weight, the total of the nonwoven The weight is characterized in that it is 10 to 100gsm.

According to another aspect of the invention, the dispersant is characterized in that it comprises a hydrophilic portion that is miscible with the polylactic acid polymer and a hydrophobic portion that is miscible with the polypropylene polymer.

According to another configuration of the present invention, the component of the dispersant is characterized in that the styrene- ethylene- butylene- styrene block copolymer component.

Method for producing a non-woven fabric having a biodegradable and low carbon emission characteristics through the blend spinning of the polylactic acid of the present invention for achieving the above another object;

In the process for producing a nonwoven fabric by polylactic acid and polypropylene blend spinning,

The preparation method comprises 10 to 80% by weight of polylactic acid, 10 to 89% by weight of polypropylene and 1 to 10% by weight of the dispersant in the total weight of the polymer mixture for blending as a substantially continuous phase Forming a thermoplastic composition dry mixture by dispersing the polylactic acid and the polypropylene by uniformly dry mixing the polylactic acid in a polypropylene resin by using a dispersant;

Advantageously stirring, stirring or otherwise blending the thermoplastic composition dry mixture to effectively and uniformly mix the polylactic acid polymer, polypropylene polymer and dispersant to form a homogeneous dry mixture;

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 melt mixture; And

Spinning the melt mixture to form a web and thermocompressing to form a nonwoven fabric;

It characterized in that the total weight of the nonwoven fabric is prepared to be 10 to 100gsm.

According to another aspect of the invention, the weight of the polylactic acid in the total weight of the polymer mixture for blending is 15 to 70% by weight, the weight of polypropylene is 22 to 83.5% by weight, the weight of the dispersant is 1.5 to 8% by weight Wherein, the total weight of the nonwoven fabric is characterized in that 15 to 90gsm.

According to another configuration of the invention, the weight of the polylactic acid in the total weight of the polymer mixture for blending is 20 to 60% by weight, the weight of the polypropylene is 35 to 78% by weight, the weight of the dispersant is 2 to 5% by weight The weight of the nonwoven fabric is 15 to 90 gsm.

According to another configuration of the present invention, the polylactic acid is characterized by using a polylactic acid having a melt flow index (MI: Melt Index, 210 ° C) of 70 to 85 g / 10 minutes.

Biodegradable and low carbon emission properties through the blend spinning of the polylactic acid of the present invention configured as described above and a method for producing the same non-woven fabric using a dispersant specific to the polylactic acid / polypropylene blend to specify the manufacturing process conditions during mixing and spinning The polylactic acid and polypropylene are uniformly mixed and spun and nonwoven, and the physical properties are similar to or superior to those of the conventional non-woven spun only with polypropylene, and the manufactured nonwoven fabric is advantageous in reducing carbon emissions. It provides a useful configuration that solves the technical problem.

EMBODIMENT OF THE INVENTION Hereinafter, it demonstrates in detail by preferred embodiment of this invention.

Prior to describing the present invention in detail, the polylactic acid is generally defined by the polymerization of lactic acid or lactide, and is thus used in the present invention, as defined above for the polylactic acid used throughout the present specification. The term "polylactic acid" is intended to denote a polymer prepared by the polymerization of lactic acid or lactide. The lactic acid may be polymerized using any known polymerization method such as polycondensation or ring-opening polymerization. In the polycondensation process, for example L-lactic acid, D-lactic acid or mixtures thereof are applied directly to dehydration-polycondensation. In the ring-opening polymerization process, lactide, a cyclic dimer of lactic acid, is subjected to polymerization with the aid of polymerization regulators and catalysts. Lactides may include L-lactide, D-lactide and DL-lactide (also called meso-lactide, condensates of L-lactic acid and D-lactic acid). Each such lactide (ie, 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 stereochemical isomers, namely the R isomer and the S isomer shape. D-lactide comprises two R isomers, L-lactide comprises two S isomers, and meso-lactide includes the R and S isomers. Different isomers can be mixed and polymerized if necessary to obtain polylactic acid having any desired composition and crystallinity as described in more detail below. In addition, small amounts of chain extenders (eg diisocyanate compounds, epoxy compounds or acid anhydrides described below) may be used to increase the molecular weight of polylactic acid. 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 can be used in the present invention include, but are not limited to, one specific example commercially under the name Natureworks (Natureworks®) of Minneapolis, Minn. Available. Other suitable polylactic acid polymers are commercially available from BIOMER ™ L9000 or Mitsui Chemical (LACEA ™) from Biomer, Inc., Cryling, Germany. It is possible. Still other suitable polylactic acids are described in US Pat. Nos. 4,797,468; No. 5,470,944; 5,770,682; No. 5,821,327; 5,880,254; 5,880,254; And 6,326,458 can be used.

In addition, the melt flow index of the polylactic acid can be forced through an extrusion flow meter orifice (0.0825 inches in diameter) when applied to a load of 2160 g in 10 minutes at any temperature (eg 210 ° C.), ASTM test method D1238-. The weight (g) of the polymer measured according to E is shown. Polylactic acid also typically has a melting point of about 100 ° C. to about 240 ° C., in some embodiments from about 120 ° C. to about 220 ° C., and in some embodiments from about 140 ° C. to about 200 ° C. These low melting polylactic acids are useful in that they biodegrade at high speed. The glass transition temperature (“Tg”) of polylactic acid is also relatively low to improve the solubility and processability of the polymer. For example, the Tg may be about 80 ° C. or less, in some embodiments about 70 ° C. or less, and in some embodiments about 65 ° C. or less. As discussed in more detail below, both the melting point and glass transition temperature can be determined using a differential scanning calorimeter (“DSC”) in accordance with ASTM D-3417.

The polylactic acid polymers described above are generally prepared by polymerization of lactic acid. However, it will be appreciated by those skilled in the art 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 denote a polymer produced by the polymerization 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 (eg, a polypropylene polymer) that exhibits desirable properties. The polylactic acid polymer is generally present in the thermoplastic composition in an amount of about 10 wt% to about 80 wt%, suitably about 15 wt% to about 70 wt%, more suitably about 20 wt% to about 60 wt%. Wherein all weight percents are based on the total weight of polylactic acid polymer, polypropylene polymer and dispersant present in the thermoplastic composition. It is important to maintain the composition ratio of the three components in the thermoplastic composition because the polypropylene polymer generally needs to be in a substantially continuous phase in order for the thermoplastic composition to be substantially spun to form a nonwoven. The approximate limit of the component ratio can be determined based on the density of the components. The density of the components is converted into volumes (estimated 100 g of each component), the volumes of the components are added together to obtain the volume of the entire thermoplastic composition, and the weight average of the components is calculated to obtain a thermoplastic composition in which the polylactic acid polymer in the blend takes up the bulk. An approximate minimum ratio of each component required to make can be obtained.

Polypropylene polymers are also known in the art as resins belonging to polyolefinic polymers. Any polyolefin that can be made into an article, such as spunbond long fibers, is considered suitable for use in the present invention. Polypropylene can be either high or low density, and generally can be a straight or branched chain polymer. Methods of making polypropylene are known to those of ordinary skill in the art.

Polypropylene as described above is generally hydrophobic in nature. The term 'hydrophobic' as used herein refers to a material having a contact angle of water in air of at least 90 degrees. In contrast, the term 'hydrophilic' herein refers to a material whose contact angle of water in air is less than 90 degrees. According to the present invention, said 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].

It is generally preferred that both the polylactic acid polymer and polypropylene are melt processable. Therefore, the polylactic acid polymer and polypropylene are about 1 gram per 10 minutes to about 200 grams per 10 minutes, suitably about 10 grams per 10 minutes to about 100 grams per 10 minutes, more suitably about 20 grams per 10 minutes. It is preferred to exhibit a melt flow rate of about 40 grams per to 10 minutes. Melt flow rates of the materials can be obtained according to ASTM test method D1238-E, which is incorporated herein by reference.

It has been found that it is desirable to improve the processability of polylactic acid polymers and polypropylene polymers because the polymers are not chemically identical and are therefore somewhat immiscible with each other, which tends to adversely affect the processing of mixtures of the polymers. For example, polylactic acid polymers and polypropylene polymers are sometimes difficult to mix by themselves effectively and difficult to prepare as essentially homogeneous mixtures. In general, it has been found to be desirable to use dispersants to assist in the efficient preparation of polylactic acid polymers and polypropylene polymers and processing into single thermoplastic compositions.

Dispersants suitable for use in the present invention generally include a hydrophilic portion that becomes miscible with the polylactic acid polymer and a hydrophobic portion that becomes miscible with the polypropylene polymer. These hydrophilic and hydrophobic moieties are generally present in separate blocks such that the entire dispersant structure can be diblock or random block. Dispersants are generally preferred to initially act as plasticizers to improve the preparation and processing of thermoplastic compositions. Among the nonwoven materials of the present invention which are then processed from thermoplastic compositions, it is generally preferred that the dispersant act as a surfactant by changing the contact angle of water in the air of the processed material. The hydrophobic portion of the dispersant may be polystyrene, but is not limited to these. The hydrophilic portion of the dispersant may contain ethylene oxide, ethoxylates, glycols, alcohols or any mixture thereof. The component of a suitable dispersant is preferably a styrene-ethylene-butylene-styrene block copolymer component.

It is generally preferred that the dispersant is present in the thermoplastic composition in an amount effective to produce the thermoplastic composition exhibiting the desired properties. In general, minimal amounts of dispersant are necessary 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 about 1% to about 10% by weight, preferably about 1.5% to about 8% by weight, more preferably about 2% to about 5% by weight. Wherein all weight percents are based on the total weight of polylactic acid polymer, polypropylene polymer and dispersant present in the thermoplastic composition. Although the main components of the thermoplastic composition have been described above, the thermoplastic composition may include other components that are not limited thereto and 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, rheology accelerators, solid solvents, plasticizers, nucleating agents, particulates, and materials added to improve processability of thermoplastic compositions. Include, without limitation. When the additional components are included in the thermoplastic composition, the additional components are advantageously used in an amount of less than about 5 weight percent, more advantageously less than about 3 weight percent, suitably less than about 1 weight percent. Generally preferred, wherein all weight percents are based on the total weight of polylactic acid polymer, polypropylene and dispersant present in the thermoplastic composition.

The thermoplastic composition used in the present invention is generally obtained in the form of a mixture of polylactic acid polymers, polypropylene polymers, dispersants and optionally any further components. The polylactic acid polymer forms a substantially discontinuous phase surrounded within the continuous phase of the substantially polypropylene polymer. In order to achieve the desired properties for the thermoplastic composition, it is desirable that the polylactic acid polymer, polypropylene polymer and dispersant remain substantially unreacted with each other. To this end, each of the polylactic acid polymer, polypropylene and dispersant 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, with the polypropylene polymer continuous phase substantially surrounding the polylactic acid polymer within its structure.

In one embodiment of the present invention, the polylactic acid polymer, the polypropylene polymer and the dispersant are dry mixed together to form a thermoplastic composition dry mixture, which is then advantageously stirred, agitated or otherwise Blending effectively and uniformly mixes the polylactic acid polymer, polypropylene polymer and dispersant to form an essentially homogeneous dry mixture. The dry mixture is then melt blended, for example in an extruder, to effectively and uniformly mix the polylactic acid polymer, polypropylene polymer and dispersant to form an essentially homogeneous melt mixture.

It will be described a method for producing multicomponent fiber made from the thermoplastic composition described above. Melt spinning of polymers involves the production of structures of continuous filaments, such as spunbond or meltblown, and discontinuous filaments, such as staples and short-cut fibers. To produce spunbond or meltblown fibers, the thermoplastic composition is usually extruded and fed to a dispensing system, where the thermoplastic composition is introduced into the spinneret plate. The spun fibers are then cooled, solidified and drawn into aerodynamic systems to form conventional nonwovens. On the other hand, to produce shot or staple fibers, rather than forming them directly into nonwoven structures, the spun fibers are cooled, solidified, drawn and collected to intermediate filament diameters, generally with a mechanical roll system. The fibers are then 'cold drawn' to the desired final fiber diameter at temperatures below their softening temperature, crimped or shaped and cut to the desired fiber diameter.

The cooling process for drawing the extruded thermoplastic composition and / or fibers preferably uses cooling means that do not contain water because the composition comprises water soluble components. Cooling is generally accomplished by blowing air at or below ambient temperature over the extruded polymer. In this case, the cooling temperature is generally preferably between 10 and 20 ° C, more preferably from 13 to 18 ° C.

Polylactic acid materials often undergo thermal shrinkage during the later heat treatment. Heat shrinkage occurs mainly due to the heat induced chain relaxation of the polymer segments in the amorphous and incomplete crystalline phases. 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 directly melts, rather than enabling chain relaxation and reordering of the incomplete crystalline structure. A typical solution to this problem is to apply a thermoset to the material. For this reason, when the produced material, for example, the fiber, reaches the bonding roll and undergoes heat curing treatment, the fiber is substantially completely oriented or very much so that it does not substantially shrink. The present invention eliminates the need for this additional processing step because of the morphology of the multicomponent fibers. As mentioned above, polypropylene generally provides a reinforcing structure that minimizes the predicted thermal shrinkage of polylactic acid.

As described above, the method for producing a nonwoven fabric through polylactic acid and polypropylene blend spinning according to the present invention can be substantially decomposed by dispersing polylactic acid and polypropylene as a substantially continuous phase by dispersing the polylactic acid evenly in a polypropylene resin. It is possible, however, to produce nonwoven fabrics that can be easily processed into nonwoven structures that exhibit the effective mechanical and liquid processing properties of the fibers.

According to a preferred embodiment of the present invention, in a non-woven fabric production method through polylactic acid / polypropylene blend spinning, an extruder at a constant ratio with polypropylene using a dosing system for weighing polylactic acid and a dispersant. Wherein the dosage of polylactic acid is advantageously from about 10% to about 80% by weight, suitably from about 15% to about 70% by weight, more suitably about 20% by weight as described above. It is preferred that the amount is from% to about 60% by weight. If the polylactic acid input rate is less than 10% by weight, there is a problem of low carbon reduction efficiency, and when it exceeds 90% by weight, there is a problem that it is difficult to increase the amount of secondary raw materials in the equipment of the general operation, and there is a problem of cost increase. Not desirable The dosage of the dispersant is also advantageously in an amount of about 1% to about 10% by weight, suitably about 1.5% to about 8% by weight, more suitably about 2% to about 5% by weight. It is preferable. If the feed rate of the dispersant is less than 1% by weight, the blending effect of polylactic acid and polypropylene is reduced, resulting in excessive pressure rise of the die and a large amount of thread breakage, and a cost increase in excess of 10% by weight. It is not desirable because there is. In addition, the dosage of the polypropylene is generally 10 to 89% by weight, suitably 22 to 83.5% by weight, more preferably 35 to 78% by weight.

The polylactic acid / polypropylene blend mixture comprising the dispersant is a thermoplastic or spinnable polymer. The term "mixture" as used herein includes a homogeneous mixture of two or more polymers or a heterogeneous mixture of two or more physically distinct polymers, such as bi-comonents. Next, the polylactic acid / polypropylene blend mixture containing the dispersant is spun, the spun filaments being solidified by the cooling air injected through the honeycomb chamber and blown from above and the pressure of the air drawn under the conveyor belt. Is stretched and laminated to a constant weight on a conveyor belt to form a web. The web may 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 discharge per layer and the speed of the belt being transferred. Finally, the integrated web is thermally bonded to impart mechanical properties and shape stability. Although it does not limit the adhesion area, the calender roll is composed of an emboss roll surface having a bonding area of 10 to 20% by weight on one side and a roll having a smooth surface on the other side. The web integrated in multiple layers is sheeted while passing through the roll. Bonding the long-fiber nonwoven web by any process well known in the art, such as in the bonding of integrated webs, as well as those selected from the group consisting of chemical bonding (resin bonding), water flow bonding and needle punching. To form a nonwoven fabric. Preferably thermal bonding may be used.

Hereinafter, the nonwoven fabric of this invention is demonstrated concretely by an Example. These examples are only presented by way of example only to more specifically describe the present invention, it will be apparent to those skilled in the art that the scope of the present invention is not limited by these examples. .

The measurement and evaluation methods of various properties of the composite long fiber nonwoven fabric in the following examples and comparative examples were analyzed by the following methods:

(1) Tensile strength: A specimen of 5 cm sample width and 7.5 cm sample length was measured under a tensile velocity of 300 mm / min using ASTM D1682-64 method using an Instron tensile elongation measuring equipment. box.

(2) Tensile elongation: Elongation at maximum tensile strength measured by the method of (1) above is obtained.

In addition, in the following examples and comparative examples, fibers were prepared using various amounts of polylactic acid, polypropylene, and dispersant, which polylactic acid polymers (PLAs) were obtained from Natureworks, Minneapolis, Minn. The melt flow index (MI: Melt Index) ranged from 15 to 30 g / 10 minutes, the polypropylene polymer (PP) obtained the trade name SFR-171H from Honam Petrochemical, and the melt flow index (MI: Melt Index) reached 35 g / 10 minutes. It had a melting temperature of about 160 ℃, the dispersing agent was obtained from the JSR Corporation of Tsukiji, Japan, pursuant to the trade name DYNARON 8630P and used in the method of producing a nonwoven fabric using the same Polypropylene and dosing systems for weighing raw materials of lactic acid and dispersants The mixture is delivered to the extruder at a constant rate to radiate the mixture, and the filaments are stretched by the solidified and cooled air blown through the honeycomb chamber and the pressure of the air drawn from the lower part of the conveyor belt. And then laminated on a conveyor belt with a constant weight to form a web, then thermal bonding to prepare a nonwoven fabric.

Example 1

10% by weight of polylactic acid, 3% by weight of dispersant, and 87% by weight of polypropylene resin were melted and spun to fiber and stretched on a porous conveyor belt to prepare a polylactic acid / polypropylene nonwoven fabric having a basis weight of 40 gsm. Measured physical properties of are shown in Table 1 below.

Example 2

A nonwoven fabric was prepared in the same manner as in Example 1 except that 20 wt% of polylactic acid, 5 wt% of a dispersant, and 75 wt% of a polypropylene resin were prepared, and the physical properties of the prepared nonwoven fabric were measured and shown in Table 1 below. .

Comparative Example 1

A nonwoven fabric was prepared in the same manner as in Example 1, except that 10 wt% of polylactic acid, 0.5 wt% of a dispersant, and 89.5 wt% of a polypropylene resin were prepared, and the physical properties of the prepared nonwoven fabric were measured and shown in Table 1 below. .

Comparative Example 2

A nonwoven fabric was prepared in the same manner as in Example 1, except that 100 wt% of polypropylene resin was added, and the physical properties of the prepared nonwoven fabric were measured and shown in Table 1 below.

Item Gross weight
(gsm) Polylactic acid
content(%) Dispersant
content(%) Polypropylene
content(%) Strength (MD)
(kgf / 5cm) Strength (CD)
(kgf / 5cm) Radioactive Example 1 40 10 3 87 8.0 5.2 Good Example 2 40 20 5 75 10.0 6.3 Good Comparative Example 1 40 10 0.5 89.5 - - Irradiated Comparative Example 2 40 - - 100 7.8 5.1 Good

Claims (7)

In nonwoven fabrics made through polylactic acid and polypropylene blend spinning,
The weight of the polylactic acid in the total weight of the polymer mixture for the polylactic acid and polypropylene blend is 10 to 80% by weight, the weight of polypropylene is 10 to 89% by weight, the weight of the dispersant is 1 to 10% by weight , The total weight of the nonwoven fabric is 10 to 100gsm, characterized in that the non-woven fabric having biodegradability and low carbon emission characteristics through blend spinning of polylactic acid.
2. The biodegradable and low carbon emission properties of blends of polylactic acid according to claim 1, characterized in that the dispersing agent comprises a hydrophilic portion which is miscible with the polylactic acid polymer and a hydrophobic portion which is miscible with the polypropylene polymer. Nonwoven fabric.
3. The nonwoven fabric of claim 1 or 2 wherein the component of the dispersant is a styrene-ethylene-butylene-styrene block copolymer component. .
In the process for producing a nonwoven fabric by polylactic acid and polypropylene blend spinning,
The preparation method comprises 10 to 80% by weight of polylactic acid, 10 to 89% by weight of polypropylene and 1 to 10% by weight of the dispersant in the total weight of the polymer mixture for blending as a substantially continuous phase Forming a thermoplastic composition dry mixture by dispersing the polylactic acid and the polypropylene by uniformly dry mixing the polylactic acid in a polypropylene resin by using a dispersant;
Advantageously stirring, stirring or otherwise blending the thermoplastic composition dry mixture to effectively and uniformly mix the polylactic acid polymer, polypropylene polymer and dispersant to form a homogeneous dry mixture;
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 melt mixture; And
Spinning the melt mixture to form a web and thermocompressing to form a nonwoven fabric;
Method for producing a non-woven fabric having a low biodegradability and biodegradability through blend spinning of polylactic acid, characterized in that the total weight of the nonwoven fabric to 10 to 100gsm.
The weight of the polylactic acid in the total weight of the polymer mixture for blending is 15 to 70% by weight, the weight of polypropylene is 22 to 83.5% by weight, the weight of the dispersant is 1.5 to 8% by weight , The total weight of the nonwoven fabric is 15 to 90gsm, characterized in that the biodegradable and low carbon emission properties of the polylactic acid through the blend spinning of polylactic acid.
The weight of the polylactic acid in the total weight of the polymer mixture for blending is 20 to 60% by weight, the weight of polypropylene is 35 to 78% by weight, the weight of the dispersant is 2 to 5% by weight , The total weight of the nonwoven fabric is 15 to 90gsm, characterized in that the biodegradable and low carbon emission properties of the polylactic acid through the blend spinning of polylactic acid.
5. The biodegradable and low carbon emission characteristics of the polylactic acid through blend spinning of polylactic acid according to claim 4, wherein the polylactic acid uses polylactic acid having a melt flow index (MI: Melt Index, 210 ° C) of 70 to 85 g / 10 minutes. Method for producing a nonwoven fabric having a.