KR100616467B1 - Composition for high-moisture permeable porous films and porous films produced by them - Google Patents

Abstract

The present invention is less than 30,000 of the weight average molecular weight obtained by extraction with n-hexane when producing a high-density polyethylene resin with respect to 100 parts by weight of the inorganic filler, melt index (190 ℃, 2.16Kg) 50g / 10min or more ethylene-based polymer or the ethylene-based 100 parts by weight of an inorganic filler coated with an ethylene polymer obtained by mixing, stirring and dispersing 1-10 parts by weight of a mixture composed of 70 to 95% by weight of the polymer and 5 to 30% by weight of saturated fatty acid in the melting point of 40 to 80 ° C, Melt Index (190 ° C, 2.16Kg) A compound composition for breathable films composed of 20 to 250 parts by weight of a polyolefin resin in the range of 1 to 10 g / 10 min, and a disc sheet obtained by extrusion melting the composition, has an area stretching ratio of 1.5 to 36 times. The present invention relates to a breathable film, which is obtained by stretching to a. The breathable film according to the present invention has excellent high moisture permeability and economy while maintaining existing mechanical properties. It is useful for diapers, training pants, sanitary napkins, sanitary panties, incontinence equipment, bandages, absorbent products such as medical clothing, and building materials such as house wraps.

Ethylene polymer, saturated fatty acid, partial coating, inorganic filler, polyolefin resin, breathable film

Description

Compound composition for highly breathable breathable film and breathable film using the same {Composition for high-moisture permeable porous films and porous films produced by them}

The present invention relates to a compound composition for breathable films having excellent high moisture permeability and economy while maintaining the existing mechanical properties and a breathable film using the same.

   Currently, the breathable film is used in various fields such as diapers, training pants, sanitary napkins, sanitary panties, incontinence equipment, bandages, medical clothing, absorbent products for body protection, and building materials for condensation prevention such as house wraps. Although several methods have been proposed, the most economical method is to add a polyolefin resin such as polyethylene or polypropylene at a specific magnification, and then uniaxially or biaxially stretch the disc sheet obtained by melt coating by a known method. Many methods for obtaining a breathable film by forming fine pores between a polyolefin resin and an inorganic filler have been proposed (see Japanese Patent Laid-Open Nos. 58-149303, 60-185803, 59-69906, etc.).

   However, the above manufacturing method is still required to increase the moisture permeability, which can be called representative properties while maintaining the existing mechanical properties, and further development of a more economical method for lowering the manufacturing cost is required.

   In this respect, many methods for producing a breathable film using a composition of a very cheap calcium carbonate and a polyolefin resin among inorganic fillers have been developed and used. However, this method lacks the compatibility between calcium carbonate having a hydrophilic surface property and a lipophilic polyolefin resin, and thus a large amount of microdispersion of an inorganic filler occurs in the preparation of the compound composition. Because of this, breakage of the film is likely to occur, and mechanical properties of the obtained film are also deteriorated, and thus, it has been difficult to obtain a breathable film having high moisture permeability while maintaining excellent mechanical properties.

   In order to improve this problem, a method of using a modified inorganic filler uniformly treated with a higher fatty acid such as stearic acid has been proposed instead of the inorganic filler. In other words, such modified inorganic fillers have a structure in which hydrophilic acid components of higher fatty acids are fixed to inorganic fillers having hydrophilic surface properties and have long lipophilic alkyl groups derived from the surface. To solve the conventional problem by greatly improving the compatibility by. However, the modified inorganic filler prepared by this method is expensive, the content of the inorganic filler in the composition is very large, the economic efficiency is further worsened, and the excellent compatibility is advantageous in terms of dispersion, while the inorganic filler and polyolefin resin during the stretching process It is difficult to obtain a high moisture-permeable breathable film due to the problem that the pore generation is difficult between and is required to develop a method for improving dramatically.

MEANS TO SOLVE THE PROBLEM In order to solve the said problem, the present inventors earnestly studied and came to this invention.

That is, the present invention is to provide a compound composition for a breathable film and a breathable film using the same having excellent breathability while maintaining the existing mechanical properties and at the same time excellent economy.

In order to solve the above problems, the present invention has a weight average molecular weight of 30,000 or less obtained by extraction with boiling n-hexane when preparing a high density polyethylene resin based on 100 parts by weight of an inorganic filler, melt index (190 ℃, 2.16Kg) 50g / 10min 100 parts by weight of an inorganic filler coated with an ethylene polymer obtained by mixing, high speed stirring and dispersing 1 to 10 parts by weight of the above ethylene polymer and a polyolefin resin 20 to 250 in a melt index (190 ° C., 2.16 Kg) of 1 to 10 g / 10 min. It is to provide a compound composition for breathable film, characterized in that consisting of parts by weight.

   In addition, the present invention is a weight average molecular weight of less than 30,000 produced by boiling n-hexane when produced a high density polyethylene resin based on 100 parts by weight of the inorganic filler, melt index (190 ℃, 2.16Kg) 50g / 10min or more ethylene-based polymer 70 100 parts by weight of an inorganic filler coated with an ethylene polymer and a melt index obtained by mixing, rapidly stirring and dispersing 1-10 parts by weight of a mixture composed of ~ 95% by weight and 5-30% by weight of saturated fatty acid having a melting point of 40-80 ° C. 190 ° C, 2.16Kg) It is to provide a compound composition for breathable film, characterized in that composed of 20 to 250 parts by weight of a polyolefin resin in the range of 1 ~ 10g / 10min.

   Moreover, this invention provides the breathable film obtained by extending | stretching the original sheet which melt-molded the obtained compound composition for breathable films in the range of 1.5 to 36 times area draw ratio.

   In the case of manufacturing a breathable film by compounding a composition of a conventional polyolefin and an untreated inorganic filler, the surface of the inorganic filler is hydrophilic, so the compatibility with the polyolefin resin is very bad, the fracture occurs during the stretching process, and the physical properties are bad. In addition, the modified inorganic filler coated with an inorganic filler with a higher fatty acid is treated with an expensive higher fatty acid, thereby increasing the price naturally. Also, due to the nature of the higher fatty acid, the hydrophilic acid component is relatively easy and uniform on the surface of the hydrophilic inorganic filler. The coated and lipophilic aliphatic long chain is easily mixed with the polyolefin, which has a good overall compatibility between the modified inorganic filler and the polyolefin, which is a matrix resin, which advantageously reduces the fine dispersion, but does not form pores in the stretching process, and thus has excellent air permeability. Manufacture This is a disadvantage.

Therefore, the inorganic filler may not be excellent in compatibility with the matrix resin, and the usability is too low, and when crushing occurs during stretching, it is difficult to bring about a decrease in physical properties, so in the present invention, the surface of the inorganic filler is coated. If the surface condition after treatment is only partially coated, unlike the treatment with higher fatty acids, the inorganic filler and the matrix may be controlled by controlling the compatibility of the polyolefin resin with the inorganic filler treated with the higher fatty acid. During the stretching process, while improving the dispersibility with the polyolefin resin, the pore generation is promoted in the partially uncoated part, and it is found that many pores can be easily expressed while maintaining the existing mechanical properties as a whole, thereby ensuring high breathability. The present invention was completed.

Inorganic fillers used in the present invention include calcium carbonate, talc, clay, kaolin, silica, diatomaceous earth, magnesium carbonate, calcium chloride, calcium sulfate, aluminum hydroxide, zinc oxide, magnesium hydroxide, titanium oxide, alumina, mica, asbestos powder, zeolite Clay, silicate or mixtures thereof are used. Examples of the inorganic filler include plate, needle and sphere, but spheres are most preferred, and the average particle diameter is in the range of 0.1 to 5 μm, preferably 0.5 to 3 μm. When the average particle diameter is 0.1 μm or less, there is a concern that the coating state of the ethylene polymer according to the present invention may be too poor, and when 5 μm or more, the surface appearance of the stretched breathable film may be poor.

The coating agent coating the inorganic filler of the present invention has a compatibility enough to coat a part of the inorganic filler, the weight average molecular weight of 30,000 or less produced by extraction by boiling n-hexane during the production of high-density polyethylene-based resin, melting An ethylene-based polymer having an index (190 ° C., 2.16 Kg) of 50 g / 10 min or more is used. These ethylene-based polymers usually occur as cakes in the process, but if they are pulverized well, they have a wax-like shape, and due to the inclusion of ethylene-based polymer components with lower molecular weights of hundreds to thousands, they have some flowability even at tens of degrees Celsius. When it reaches about 100 ° C. or more, it has better flowability, and the coating property is expressed to some extent through the mixing and the high speed stirring process for the inorganic filler in the high speed mixer. However, since the ethylene-based polymer is lipophilic, and unlike high-fatty acids having both hydrophilicity and lipophilic property, coating property is poor, it is possible to obtain an inorganic filler having a partially coated structure originally intended, thereby completing the present invention. have.

The ethylene-based polymers generally have a molecular weight distribution due to the resin properties when the high density polyethylene resin is prepared by a Ziegler-Natta catalyst or a chromium catalyst system, and thus a low molecular weight component is naturally produced. Films and containers that require high molecular weight are extracted and removed by boiling n-hexane in that they may adversely affect resin properties. The ethylene polymer obtained in this removal process has a very wide molecular weight distribution. It is a low molecular weight component with no special use, so it is treated as industrial waste and its treatment is very difficult. Recently, wax manufacturers that require a narrow range of molecular weight distribution, for example, have been attempted to separate and purify them again. However, due to the low economic feasibility, they have been treated at almost waste level prices. Such a very inexpensive, large and stable weight average molecular weight of less than 30,000, ethylene polymer of more than 50g / 10min melt index (190 ℃, 2.16Kg) as a surface modification treatment agent of the inorganic filler as a coating agent suitable for the purpose of the present invention Used.

 In another embodiment of the present invention, the ethylene-based polymer according to the present invention can be sufficiently achieved as a kind of coating agent for the inorganic filler as described above, although it is somewhat disadvantageous from the economic point of view of the melting point of 40 ~ 80 ℃ If you use a mixture of saturated fatty acids in the range of 5 to 30% by weight is more effective. In other words, saturated fatty acid having low melting point and hydrophilicity simultaneously dissolves at low temperature at the beginning of agitation, and contributes more effectively to dispersion than lipophilic ethylene-based polymers for hydrophilic inorganic fillers. So it is better to use a small amount added. However, when the mixing ratio is more than 30% by weight, the coating property is so good that it is difficult to form a target partial coating structure, and the economy is poor due to the high cost. In addition, when saturated fatty acids exceed the melting point of 80 ° C., an ethylene polymer component having flowability at tens of ° C. first contributes to the initial dispersing phase, and is intended to improve the performance of dispersing promotion even though the economy is poor. Not so desirable. Specific examples of saturated fatty acids in the range of 40 ° C to 80 ° C include lauric acid with a melting point of 45 ° C, myristic acid with two melting points of 54 ° C and 58 ° C, palmitic acid with a melting point of 63 ° C, and stearic acid with a melting point of 71 ° C. Etc. can be mentioned.

On the other hand, the inorganic filler of the partial coating structure may be slightly expressed by the mixing, high-speed stirring process in the mixer even by the conventional polyolefin wax, not the ethylene polymer according to the present invention, but is not sufficient. In other words, in the case of the ethylene polymer according to the present invention, the molecular weight distribution is extremely wide, and then the coating starts with flowability gradually from the low molecular weight component, and the temperature increases due to the natural frictional heat between the inorganic fillers by high-speed agitation and eventually to the high molecular weight component. While it has a flowability and is coated, it does not have coating property as high fatty acid, but it has a considerable amount of coating. On the other hand, polyolefin wax has a very narrow molecular weight distribution and has no flowability at low temperatures of several tens of degrees. And polyolefins are somewhat different, but because they suddenly flow only after reaching a certain temperature of about 100 ℃ or more, it takes a lot of coating time and expresses the inorganic filler of the partial coating structure coated only a very small amount. Peel having pain resistance while maintaining mechanical properties of Difficult to obtain. In addition, since the conventional polyolefin wax is very expensive, the economics aimed at in the present invention cannot be achieved.

Further, as in the ethylene polymer according to the present invention or in Japanese Patent Laid-Open No. 2001-233982, a disc sheet obtained by ordinary kneading and extrusion processing using a composition obtained by simply mixing a polyolefin wax with an inorganic filler and a polyolefin resin is used. It may be considered to prepare a breathable film by stretching, in which case the polyolefin resin and the ethylene polymer or polyolefin wax are competitively contributed to dispersion for the inorganic filler during the kneading of the composition. In terms of activity, ethylene-based polymers or polyolefin waxes are advantageous for dispersion, but a large amount of polyolefin resin is present, so that a lot of excess ethylene-based polymers or polyolefin waxes, which do not contribute to the dispersion of inorganic fillers, present poor mechanical properties of the film. There's a traditional mechanical It is difficult to achieve high-quality purposes aiming for breathability while keeping the castle.

The inorganic filler coated with the ethylene polymer according to the present invention is obtained by mixing, stirring at high speed and dispersing 1 to 10 parts by weight of the ethylene polymer, preferably 3 to 8 parts by weight, based on 100 parts by weight of the inorganic filler. If the added amount of the ethylene polymer is 1 part by weight or less, the coating amount is too small to obtain a desired effect. When the amount of the ethylene polymer is more than 10 parts by weight, an excess amount that does not contribute to the coating flows into the composition, which in turn lowers the mechanical strength of the breathable film. There is concern.

The polyolefin resins used in the present invention are homopolymers including low density polyethylene, linear low density polyethylene, medium density polyethylene, and high density polyethylene or copolymers based on ethylene, polypropylene homopolymers or copolymers based on propylene, and poly Butene or mixtures thereof are used. The polyolefin resin is not limited as long as it has a molecular weight of about to form a film, but in the present invention, the use of a polyolefin resin having a melt index (190 ° C., 2.16 Kg) in the range of 1 to 10 g / 10 min provides mechanical properties and imperfection characteristics. Useful for maintenance purposes.

To the compound composition for breathable film in the present invention, it is also possible to add ordinary additives such as lubricants, antioxidants, processing aids, white enhancers, desiccants, heat stabilizers, fluorescent agents and the like.

Hereinafter, the compound composition for a breathable film of this invention and the manufacturing method of a breathable film are demonstrated in detail.

Powdered inorganic filler is added to a conventional mixer, and gradually stirred, while gradually stirring a ethylene-based polymer or a suitable mixture of the obtained ethylene-based polymer and saturated fatty acid in a cake state. If you put them all at once, they get stuck together and cannot get the desired coating state. When the appropriate mixture of ethylene-based polymer or ethylene-based polymer and saturated fatty acid is added, the stirring speed is gradually increased. When stirring at a relatively high constant stirring speed, the temperature is increased by natural frictional heat between the inorganic filler powders even if the temperature is not increased. When the mixture is raised to about 120 to 130 ° C. and stirred at high speed for about 20 to 30 minutes, an appropriate mixture of ethylene-based polymer or ethylene-based polymer and saturated fatty acid has flowability and is naturally coated on the inorganic filler powder surface. The conditions such as kneading speed and time vary depending on variables such as the type of inorganic filler selected, particles, specific surface area, addition amount of ethylene-based polymer or mixture of ethylene-based polymer and saturated fatty acid, type of mixer, etc. You need to decide. As the mixer, a Henschel mixer, a super mixer, etc., which are easily stirred at high speed, are preferable.

In general, the inorganic filler has a high hygroscopicity and has a very high water absorption rate, so that a large amount of pinholes are formed in the molded sheet due to the generation of underwater air during the extrusion process, causing serious problems such as breaking during the stretching process. As a means to solve this problem, a method of adding an expensive quicklime masterbatch in the range of 0.5 to 3% by weight is generally adopted in consideration of the humidity during work. Therefore, there is a problem that the quality uniformity is also impaired. However, according to the present invention, in the dispersion coating process of an inorganic filler with an ethylene polymer or an ethylene polymer and a saturated fatty acid, the moisture contained in the inorganic filler is naturally removed by frictional heat generated during the high-speed stirring process. Therefore, the use of such expensive quicklime masterbatch is not used at all, and it is another great effect of the present invention that it is possible to secure uniformity of quality as well as economical efficiency.

A mixture obtained by adding and mixing a polyolefin resin and a conventional additive into an inorganic filler coated with a suitable mixture of an ethylene polymer or an ethylene polymer and a saturated fatty acid obtained by the above method is kneaded, and a conventionally known device such as a conventional shortening A screw extruder, a twin screw extruder, a mixing roll, a balm mixer, a kneader, etc. are performed suitably. The kneaded compound composition is then pelletized. The compound composition is put into a hopper to form a disc sheet according to a conventional film forming apparatus and molding method by extrusion processing. If inflation molding using a circular die or extrusion molding with a tee die is appropriately employed, good. Next, the original sheet molded by the extrusion method is uniaxially stretched in the range of 1.2 times to 6.0 times, preferably 1.5 times to 5 times, at a temperature between the glass transition point and the melting point or less. At this time, if the elongation point is less than the free point, the film cannot be stretched and elongated before the elongation exceeds the yield point. If the elongation point is exceeded, it is impossible to obtain satisfactory breathability due to the flow of the molecular chain. In addition, when the draw ratio is less than 1.2 times, sufficient air permeability cannot be obtained, and when the draw ratio is more than 6 times, breakage phenomenon occurs frequently during stretching and a film cannot be stably obtained. Subsequently, biaxial stretching is performed within the same stretching temperature and elongation conditions as in the case of monoaxial stretching to obtain a biaxially stretched breathable film. As described above, even a uniaxially oriented film which is not uniaxially oriented but uniaxially stretched, a film meeting the object of the present invention can be obtained. That is, the breathable film according to the present invention can be produced by either uniaxial or biaxial stretching, and preferably stretched so that the total area stretching ratio is in the range of 1.5 to 36 times. If the area draw ratio is less than 1.5 times, sufficient air permeability cannot be obtained, the film is hard, and the touch is degraded. If the area is over 36 times, the air permeability is excellent, but there is a possibility that the mechanical strength is significantly degraded. In order to improve the dimensional stability, the film after extending | stretching may heat-fix.

In addition, the breathable film obtained by the present invention may be a well-known embossing treatment to improve the feel and appearance, it can be used as a laminate laminated by polypropylene-based nonwoven fabric and heat, hot melt and the like.

The breathable film according to the present invention thus obtained has a wide range of applications, such as diapers, training pants, sanitary napkins, sanitary panties, incontinence devices, bandages, absorbent products for body protection such as medical clothing wraps, and products for condensation prevention construction materials such as house wraps. Can be used in the field.

As described above, the appropriate mixture of the ethylene polymer or the ethylene polymer and the saturated fatty acid according to the present invention enables the formation of a compound composition for breathable film having an appropriate dispersibility as it has a partial coating state on the inorganic filler. In addition, in the exaggeration of drawing the sheet obtained by extrusion, the pores are easily formed around the uncoated portion even under low drawing magnification, which is not seen in the prior art, resulting in high air permeability and eventually maintaining the existing mechanical strength. Significant improvements have been achieved in terms of high water vapor permeability, and the use of ethylene-based polymers is extremely inexpensive and the coating process on inorganic fillers is very simple and inexpensive. will be.

Through the following examples will be described in more detail the present invention. The following examples are only examples and are not limited to the examples. The tensile properties and the moisture permeability of the compound compositions for breathable films prepared according to the following Examples and Comparative Examples and the breathable films prepared using the same are measured as follows. It was.

(Tension properties)

In accordance with A STM D882, the strength at break (kg / in ² ) and elongation (%) were measured in the travel direction (MD) and in the width direction (TD) perpendicular to the travel direction, respectively (sample size: 100 mm length x 25mm width, tensile speed 500mm / min, measuring temperature 23 ± 1 ℃)

(Moisture permeability)

Water vapor permeability (g / m ² ~ 24hr) was measured in accordance with ASTM E96-63 (23 ± 1 ℃, 90% RH)

Example 1

Very wide weight average molecular weight distribution produced by unprocessed calcium carbonate (made by Omiya, calcium carbonate (A)) with an average particle diameter of 1.7 μm and extracted by boiling n-hexane during the production of high density polyethylene resin for film at Samsung Total Chemical Co., Ltd. A fine pulverized product of an ethylene polymer (ethylene polymer (A)) having a molecular weight of 8,500 and a melt index (190 ° C., 2.16 Kg) of 95 g / 10 min was prepared as a sample. First, calcium carbonate (A) is added to the Henschel mixer, and ethylene-based polymer (A) is gradually added at a compounding ratio of 3 parts by weight of ethylene-based polymer (A) to 100 parts by weight of calcium carbonate (A). After stirring at high temperature for 30 minutes, a sample of calcium carbonate (A) having a structure partially coated with an ethylene polymer (A) was finally obtained.

Linear low density polyethylene (SK Co., Ltd., FT811, polyolefin resin (A) having a melt index (190 ° C., 2.16 Kg) of 2.7 g / 10 min and a density of 0.932 g / cm ³ based on 100 parts by weight of the inorganic filler (I) in the Henschel mixer. )) Polyolefin resin (A) is added and mixed at a blending ratio of 100 parts by weight, which is then injected into a twin screw extruder having a screw diameter of 130 mm and melt-extruded to form pellets.

The compound composition for air permeable films of the state was obtained. The obtained compound composition was put into a hopper and the disc sheet was shape | molded using the tee-die molding machine of a screw diameter of 130 mm. The molded disc sheet was uniaxially stretched 2.5 times at a stretching temperature of 70 ° C. to prepare a breathable film having a basis weight of 20 g / m ² , and the physical properties thereof are shown in Table 1.

Example 2

In preparing a sample of the calcium carbonate (A) having a structure partially coated with the ethylene polymer (A), 5 parts by weight of the ethylene polymer (A) was added to 100 parts by weight of the calcium carbonate (A), except that In the same manner, the inorganic filler (II) was obtained. Preparation of the breathable film using this was carried out in the same manner as in Example 1. The physical properties of the obtained breathable film are shown in Table 1.

Example 3

In preparing a sample of calcium carbonate (A) having a structure partially coated with an ethylene polymer (A), Example 1 and 8 except that 8 parts by weight of the ethylene polymer (A) is added to 100 parts by weight of calcium carbonate (A) In the same manner, the inorganic filler (III) was obtained. Preparation of the breathable film using this was carried out in the same manner as in Example 1. The physical properties of the obtained breathable film are shown in Table 1.

Example 4

Inorganic filler (I) melt index of about 100 parts by weight (190 ℃, 2.16Kg) 2.7g / 10min, density 0.932g / cm ³ of linear low density polyethylene (SK (weeks), FT811, the polyolefin resin (A)) 85 parts by weight Compound composition for breathable film at a compounding ratio to which 15 parts by weight of low-density polyethylene (Hanhwa Petrochemical, 961, polyolefin resin (B)) having a melt index (190 ° C, 2.16Kg) of 5.3g / 10min and a density of 0.919g / cm ³ is added. It carried out similarly to Example 1 except having manufactured the following. The physical properties of the obtained breathable film are shown in Table 1.

Example 5

The ethylenic polymer was prepared in the same manner as in Example 1, except that 4 parts by weight of a mixture composed of 75% by weight of an ethylene polymer (A) and 25% by weight of palmitic acid was added to 100 parts by weight of calcium carbonate (A). A sample of calcium carbonate (A) (inorganic filler (IV)) having a structure partially coated with a mixture of (A) and palmitic acid was obtained. In addition, using the obtained inorganic filler (IV) instead of the inorganic filler (I) was carried out in the same manner as in Example 1 to obtain a breathable film, the physical properties are shown in Table 1.

Example 6

90 parts by weight of linear low density polyethylene (Hanhwa Petrochemical, HS1700, polyolefin resin (C)) having a melt index (190 ° C., 2.16 Kg) of 2.7 g / 10 min and a density of 0.923 g / cm ³ with respect to 100 parts by weight of inorganic filler (IV) , Compound composition for breathable film at a blending ratio of 10 parts by weight of low density polyethylene (LG chemical, LB5000, polyolefin resin (D)) having a melt index (190 ° C, 2.16Kg) 5.0g / 10min, density 0.918g / cm ³ It carried out similarly to Example 1 except having performed. The physical properties of the obtained breathable film are shown in Table 1.

Example 7

The compound composition obtained by the same method as Example 1 was put into the hopper, and the film stretched twice in the width | variety (TD) direction was shape | molded using the blow air ratio in the blow molding machine by the circular-die of screw diameter 120 mm. The molded uniaxially stretched film was stretched 2.5 times at a stretching temperature of 90 ° C. to prepare a biaxially stretched breathable film, and the physical properties thereof are shown in Table 1.

Comparative Example 1

The same procedure as in Example 1 was carried out except that calcium carbonate (A) was used instead of the inorganic filler (I). The physical properties of the obtained breathable film are shown in Table 1.

Comparative Example 2

Instead of the inorganic filler (I), the same procedure as in Example 1 was carried out except that calcium carbonate treated with stearic acid having an average particle diameter of 2.2 μm (manufactured by Nippon Asuka Carbonate, calcium carbonate (B)) was used. The physical properties of the obtained breathable film are shown in Table 1.

Comparative Example 3

It carried out similarly to Example 1 using the composition which mixed 95 weight part of polyolefin resins (A) and 5 weight part of polyethylene-type waxes (the product made from Lion Chemicals, wax (A)) with respect to 100 weight part of calcium carbonates (A). A breathable film was obtained and its physical properties are shown in Table 1.

TABLE 1

 Composition and film properties evaluation results of the resin composition obtained according to Examples 1 to 7 and Comparative Examples 1 to 3

It can be seen from the above examples that the breathable film according to the present invention exhibits excellent moisture permeability of 6,000 g / m ² to 24 hr or more while maintaining the existing mechanical properties, which is mixed in a high speed mixer for the inorganic filler as mentioned above. The mixture of ethylene-based polymer or ethylene-based polymer and saturated fatty acid is obtained through the high-speed stirring process as an inorganic filler having only a partially coated structure, which shows relatively good dispersibility to the polyolefin resin, and at the same time, partially undrawn during the stretching process. Porosity is promoted in the coated portion, it is inferred that high porosity is secured by easily expressing many pores while maintaining the existing mechanical properties as a whole. When comparing Example 1 and Example 5 it can be seen that the use of a mixture of the ethylene-based polymer and saturated fatty acid rather than the ethylene-based polymer only slightly better performance. On the other hand, if you look at Comparative Example 1, the moisture permeability is excellent but the mechanical properties are very poor, and if you look at Comparative Example 2 on the contrary, the mechanical properties are excellent but the moisture permeability is poor. In addition, in Comparative Example 3, the moisture permeability is shown to some extent, but the mechanical properties are poor, which is inferred to be due to the poor mechanical properties as the wax component does not effectively contribute to the dispersion of the inorganic filler and is present in the excess form in the polyolefin resin. do.

Compound composition for breathable film of the present invention is extracted by the boiling n-hexane to produce a high-density polyethylene-based resin with respect to 100 parts by weight of the inorganic filler, the weight average molecular weight 30,000 or less, melt index (190 ℃, 2.16Kg) 50g / 10min 1-10 parts by weight of the above ethylene-based polymer or a mixture composed of 70-95% by weight of the ethylene-based polymer and 5-30% by weight of saturated fatty acid in the melting point of 40-80 ° C. is mixed, coated with a high-speed stirring and dispersion, and coated with an ethylene-based polymer. 100 parts by weight of the inorganic filler and 20 to 250 parts by weight of the polyolefin resin in the melt index (190 ° C., 2.16 Kg) in the range of 1 to 10 g / 10 min., And the original sheet obtained by extrusion melting the compound composition for breathable film is stretched in area. The breathable film obtained by stretching in the range of 1.5 times to 36 times is a breakthrough having excellent high moisture permeability and economy while maintaining the existing excellent mechanical properties, Jeogwi, defecation practice in pants, sanitary napkins, are expected to be useful products such as construction materials sanitary briefs, incontinence appliances, bandages, medical protective clothing, such as physical absorbent products, such as house wrap for.

Claims (9)

1 to 10 parts by weight of an ethylene-based polymer having a weight average molecular weight of 30,000 or less and a melt index (190 ° C., 2.16 Kg) of 50 g / 10 min or more, which is extracted by boiling n-hexane to produce 100 parts by weight of an inorganic filler. Compound composition for breathable film comprising 100 parts by weight of coated inorganic filler (A) and 20 to 250 parts by weight of polyolefin resin (B) in the range of 1-10 g / 10 min of melt index (190 ° C., 2.16 Kg) 100 parts by weight of inorganic filler (a) Ethylene-based polymer having a weight average molecular weight of 30,000 or less, melt index (190 ° C, 2.16Kg) of 50g / 10min or more, extracted by boiling n-hexane during the production of high density polyethylene-based resin 100 parts by weight of inorganic filler (A) and a melt index (190 ° C., 2.16 Kg) coated with 1-10 parts by weight of a mixture consisting of 95% by weight and 5-30% by weight of saturated fatty acids ranging from 40 ° C. to 80 ° C. Compound composition for breathable film, characterized in that composed of 20 to 250 parts by weight of polyolefin resin (B) in the range of ~ 10g / 10min The inorganic filler according to claim 1 or 2, wherein the inorganic filler is calcium carbonate, talc, clay, kaolin, silica, diatomaceous earth, magnesium carbonate, calcium chloride, calcium sulfate, aluminum hydroxide, zinc oxide, magnesium hydroxide, titanium oxide, alumina, mica Compound composition for breathable film, characterized in that at least one selected from the group consisting of asbestos, zeolite, clay silicate. The polyolefin resin according to claim 1 or 2, wherein the polyolefin resin is composed mainly of a homopolymer comprising low density polyethylene, linear low density polyethylene, medium density polyethylene, and high density polyethylene, or an ethylene-based copolymer, a polypropylene homopolymer, or propylene as a main component. Compound composition for breathable film, characterized in that at least one compound selected from the group consisting of one copolymer and polybutene. The breathable film obtained by extending | stretching the original sheet which melt-molded the compound composition for breathable films of Claim 1 or 2 in 1.5 to 36 times of area stretch ratio. An absorbent article for body protection and building materials comprising the breathable film of claim 5. The method of claim 6,    A body protective absorbent product is a diaper, a training pant, a sanitary napkin, a sanitary panty, an incontinence device, a bandage, a medical garment, and the building material is a house wrap. 1 to 10 parts by weight of an ethylene-based polymer having a weight average molecular weight of 30,000 or less and a melt index (190 ° C., 2.16 Kg) of 50 g / 10 min or more, which is extracted by boiling n-hexane to produce 100 parts by weight of an inorganic filler. Compound composition for breathable film comprising 100 parts by weight of inorganic filler coated with ethylene polymer obtained by mixing, high speed stirring and dispersion and 20 to 250 parts by weight of polyolefin resin in the range of 1 to 10 g / 10 min of melt index (190 ° C., 2.16 Kg). To produce an air-permeable film obtained by extruding the composition in an extruder and stretching the sheet sheet obtained through a T-die or a circular die at least 1.5 times the area draw ratio under a temperature of at least the glass transition point and the melting point. Way 70 to 95% by weight of an ethylene-based polymer having a weight average molecular weight of 30,000 or less and a melt index (190 ° C., 2.16 Kg) of 50 g / 10 min or more, which is extracted by boiling n-hexane to produce 100 parts by weight of an inorganic filler. And 1-10 parts by weight of a mixture composed of 5-30% by weight of saturated fatty acid in the melting point of 40-80 ° C., and 100 parts by weight of an inorganic filler coated with an ethylene polymer obtained by stirring and dispersing at high speed and a melt index (190 ° C., 2.16). Kg) A composite sheet for a breathable film composed of 20 to 250 parts by weight of a polyolefin resin in the range of 1 to 10 g / 10 min, and the composition obtained by extrusion melting in an extruder to obtain a disc sheet obtained through a T-die or a circular die glass transition point A method for producing a breathable film, wherein the film is obtained by stretching at least 1.5 times the area draw ratio at a temperature not higher than the melting point.