KR20220056506A - Heat-Adhesive Composite Fiber With Improved Bendability - Google Patents

Abstract

The present invention relates to a heat-adhesive composite fiber with increased bendability. According to the present invention, a first component core part of the composite fiber is any one of a polypropylene (PE) or polyester (PET) resin and a second component sheath part is a mixture of 1 to 30 wt% of a low melting point polyester resin in PE. The low-melting PE resin includes an acid component formed of terephthalic acid or an ester-forming derivative thereof, and a diol component formed of 2-methyl-1,3-propanediol, 2-methyl-1,3-pentanediol, and ethylene glycol.

Description

Heat-Adhesive Composite Fiber With Improved Bendability}

The present invention relates to an olefinic heat-bonding composite fiber to which a technology for strengthening the stiffness of a nonwoven fabric is applied to improve the bendability of the nonwoven fabric for a filter.

In general, an air filter device is a device that filters fine dust and foreign substances, and is installed in a passage through which air flows in and out for a dust-free environment, so that filtered clean air flows into the device. As industry develops and environmental pollution increases, the demand for such a filter device is gradually increasing.

These air filters are divided into automobile air conditioner filters, air conditioning air filters, and the like according to their intended use.

In particular, automobile air conditioning filters filter foreign substances such as dust, pollen, automobile exhaust, exhaust gas, brake lining dust, and toxic substances contained in the air flowing into the vehicle from the automobile’s air conditioner or heater or engine room to provide clean air to the interior of the vehicle. Its importance is gradually increasing as it plays a role in bringing it into the

In general, olefin materials for filters have good static electricity imparting efficiency, but olefin-based composite fibers have a feature that is less flexible than polyester-based (PET) composite fibers.

The filter has a characteristic that the better the bendability, the higher the filter efficiency.

Therefore, in order to increase the filter lifespan, the demand for durability in harsh environments is increasing, but research on this is limited.

It is an object of the present invention to provide a nonwoven filter comprising PE/PP or PE/PET sheath-core composite fibers having excellent bendability.

In order to solve the above problems, the present invention provides a heat-adhesive composite fiber with improved bendability, wherein the first component core of the composite fiber is any one of polypropylene (PE) or polyester (PET) resin, In the two-component sheath part, polyethylene (PE) is mixed with 1 to 30% by weight of a low-melting polyester resin, and the low-melting polyester resin is an acid component composed of terephthalic acid or an ester-forming derivative thereof, and 2-methyl-1 To provide a heat-adhesive composite fiber with improved bendability, characterized in that it is formed of a diol component consisting of ,3-propanediol, 2-methyl-1,3-pentanediol, and ethylene glycol.

In addition, the present invention provides a heat-adhesive composite fiber with improved bendability, characterized in that the composite fiber has a weight ratio of 80:20 to 20:80 of the first component and the second component.

As described above, the present invention is composed of PE/PP or PE/PET sheath-core composite fibers, and a low-melting polyester resin is included in the polyethylene of the sheath. There is a characteristic.

Hereinafter, preferred embodiments of the present invention will be described in detail. First, in describing the present invention, detailed descriptions of related known functions or configurations are omitted so as not to obscure the gist of the present invention.

As used herein, the terms 'about', 'substantially' and the like are used in a sense at or close to the numerical value when the manufacturing and material tolerances inherent in the stated meaning are presented, and serve to enhance the understanding of the present invention. To help, precise or absolute figures are used to prevent unfair use by unconscionable infringers of the stated disclosure.

As used herein, the terms about, substantially, etc. are used in a sense at or close to the numerical value when the manufacturing and material tolerances inherent in the stated meaning are presented, and are intended to be accurate or to assist the understanding of the present invention. Absolute figures are used to prevent unreasonable exploitation of the stated disclosure by unscrupulous infringers.

The present invention relates to a heat-adhesive composite fiber with improved bendability.

The first component core part of the composite fiber is either polypropylene (PE) or polyester (PET) resin, and the second component sheath part is polyethylene (PE) in which 1 to 30% by weight of a low-melting polyester resin is mixed. There is a characteristic.

The first component polyester (PET) resin is a polycondensate of aromatic dicarboxylic acid and glycol, and as the aromatic dicarboxylic acid, terephthalic acid, isophthalic acid, phthalic acid, naphthalenedicarboxylic acid, etc. may be used, and the glycol is ethylene glycol , 1,3-propanediol, 1,4-butanediol, etc. may be used.

Alternatively, the first component polyester (PET) resin is a polycondensate of aromatic dicarboxylic acid and glycol, selected from polyethylene terephthalate, polyethylene 2,6-dinaphthalate, polypropylene terephthalate, polybutylene terephthalate, and polyethylene isophthalate One or a mixture of two or more may be used.

Preferably, polyethylene terephthalate may be used, and it will be preferable to use a polyester-based resin having an intrinsic viscosity (IV) of 0.50 to 0.80 dL/g measured according to ASTM 02857.

The polyethylene (PE) of the second component sheath portion may be one or a mixture of two or more selected from high-density polyethylene (HDPE), medium-density polyethylene (MDPE), low-density polyethylene (LDPE), polypropylene, and ethylene-propylene copolymer. .

Preferably, high-density polyethylene (HDPE) can be used, and the flow index (MI, Melting index) is not particularly limited, but the flow index is 1 to 100 g / 10 min, more preferably 5 to 40 g / 10 min. it would be preferable

In the second component sheath portion, 70 to 99% by weight of polyethylene (PE) and 1 to 30% by weight of a low-melting polyester resin are mixed.

The low-melting polyester resin is an acid component consisting of terephthalic acid or an ester-forming derivative thereof, and 2-methyl-1,3-propanediol, 2-methyl-1,3-pentanediol. It is formed from a diol component consisting of (2-Methyl 1,3 Pentanediol) and ethylene glycol (EG).

The 2-methyl-1,3-propanediol of the low-melting polyester resin used in the present invention has a methyl group bonded to the second carbon to facilitate rotation of the polymer main chain, and acts as a polymer end portion to provide freedom between the main chains. By widening the space, the flowability of the entire molecular chain is increased. This makes the polymer amorphous and has the same thermal properties as isophthalic acid. Due to the flexible molecular chains present in the polymer main chain, it improves elasticity and thus improves the tear properties during binding of the nonwoven fabric.

That is, 2-methyl-1,3-propanediol is a methyl group on the ethylene chain bonded to terephthalate.

By including a group (-CH3) as a side chain to secure a space so that the main chain of the polymerized resin can rotate, it induces an increase in the degree of freedom of the main chain and a decrease in the crystallinity of the resin to induce a softening point (Ts) and/or a glass transition temperature (Tg) ) can be adjusted. This may exhibit the same effect as in the case of using isophthalic acid (IPA) containing an asymmetric aromatic ring in order to reduce the crystallinity of the conventional crystalline polyester resin.

The 2-methyl-1,3-pentanediol, like 2-methyl-1,3-propanediol, has a methyl group bonded to the second carbon to facilitate rotation of the polymer main chain and impart low melting point properties to the polyester resin. It has a characteristic that increases the melt viscosity of the polyester resin with a longer molecular chain than 2-methyl-1,3-propanediol and prevents the melt viscosity from rapidly lowering at high temperatures.

The low-melting-point polyester resin of the present invention formed of the diol component as described above contains 20 to 50 moles of 2-methyl-1,3-propanediol in the low-melting-point polyester resin in order to improve low melting point characteristics and adhesion. % would be preferable.

If the content of 2-methyl-1,3-pentanediol in the diol component is less than 001 mol%, the effect of improving the melt viscosity is insignificant. 2-methyl-1,3-pentanediol may preferably contain 0.01 to 5 mol% of the diol component.

The content of 2-methyl-1,3-pentanediol is most preferably 0.05 to 2 mol%.

The low-melting-point polyester resin containing the 2-methyl-1,3-pentanediol is

The difference between the melt viscosity and the melt viscosity of 260° C. is 600 poise or less, and the melt viscosity does not decrease rapidly at high temperature.

The lower the difference between the melt viscosity of 220 ° C. and the melt viscosity of 260 ° C. of the low-melting-point polyester resin is, the lower it is preferable, and it will be more preferably 500 poise or less.

As described above, the low-melting polyester resin of the present invention containing 2-methyl-1,3-propanediol and 2-methyl-1,3-pentanediol has a softening temperature of 100°C to 150°C, and a glass transition temperature of It has excellent physical properties at 50°C to 90°C, and an intrinsic viscosity of 0.50 dL/g or more.

In addition, as for the composite fiber, it will be preferable that the first component and the second component are formed in a weight ratio of 80:20 to 20:80.

Hereinafter, examples of a method for manufacturing a heat-adhesive composite fiber having improved bendability according to the present invention are shown, but the present invention is not limited thereto.

Example 1

The core part first component polypropylene (PP) composition is 50% by weight and the sheath part second component composition contains polyethylene (PE) and low-melting polyester resin (LM) in a 9:1 weight ratio of 50% by weight to the extruder. was added and melted.

The molten first and second component compositions were introduced into a conventional sheath-core soft composite spinning apparatus and then spun at a spinning speed of 800 m/min. The composite fiber spun at a temperature higher than the glass transition temperature of polyethylene terephthalate was stretched 3.0 to 4.0 times and cut to 38 to 64 mm by applying a crimp to prepare a soft heat-adhesive composite fiber according to the present invention.

The manufactured composite fiber was prepared as a 60GSM nonwoven fabric and bent to make a filter.

Example 2

As the second component composition, the same as in Example 1, except that polyethylene and LM were in a ratio of 8:2.

Example 3

As the second component composition, the same as in Example 1, except that polyethylene and LM were in a ratio of 7:3.

Example 4

Same as Example 1 except that the first component composition was polyester (PET).

Comparative Example 1

As the second component composition, the same as in Example 1, except that polyethylene and LM were in a ratio of 10:0.

Comparative Example 2

As the second component composition, the same as in Example 1, except that polyethylene and LM were in a ratio of 6:4.

Comparative Example 3

As the second component composition, the same as in Example 4, except that polyethylene and LM were in a ratio of 10:0.

◈ Evaluation of physical properties of Examples and Comparative Examples

1. bendability

The composite fibers according to the above Examples and Comparative Examples are made of 60GSM nonwoven fabric, and a filter bent at a certain angle is measured as a specimen. The sharpness of the bent acid (∧), that is, the sharpness, was visually evaluated by two skilled workers with more than 3 years of experience before and after the environmental test, and the good degree was scored on a scale of 1 to 5 and averaged.

2. Filter efficiency

It was measured by the gravimetric method, and the sample with the best collection efficiency among all samples of Examples and Comparative Examples was regarded as 100 points, and the collection rate of the remaining samples was converted into points out of 100 points.

* Gravimetric method: A method of classifying filter grades by passing a certain amount of dust through the filter and checking the difference in the amount of dust that has passed.

Gravimetric collection efficiency (%)=[m1/(m1+m2)]x100

m1 : Weight of dust collected by the test filter

m2 : Weight of dust collected in the aft filter

3. Vestibular Charge

Static electricity was imparted to the non-woven fabric through corona discharge treatment, and the surface charge density was calculated on the non-woven fabric to which static electricity was applied through vibrating electrode technology. PE/PP Sheath/Core, a nonwoven fabric, which has the best electrostatic imparting properties, the surface charge density of M was evaluated as 10, and the remaining samples were converted to a perfect score of 10.

Example 1 Example 2 Example 3 Example 4 Comparative Example 1 Comparative Example 2 Comparative Example 3 ingredients
(50w%) pp pp pp PET pp pp PET second
ingredient
(50w%) PE
content 90w% 80w% 70w% 90w% 100w% 60w% 100w% LM
content 10w% 20w% 30w% 10w% 0w% 40w% 0w% bendability
out of 5 4.5 4.5 5.0 4.0 2.0 4.0 1.0 filter efficiency
100 points 90 90 100 80 40 20 30 electrostatic charge
10 points 7 7 6.5 5 8 4 7

As shown in Table 1, it can be seen that Examples 1 to 4 according to the present invention have excellent bendability of 4.5 or more, as compared to Comparative Examples 1 to 3, and excellent filter efficiency and static charge properties.

The features and other advantages of the present description as described above will become more apparent from the examples described below, and the following examples are only described for illustrative purposes and cannot be construed as limiting or limiting the protection scope of the present invention. .

Claims (2)

In the heat-adhesive composite fiber with improved bendability,
The first component core of the composite fiber is either polypropylene (PE) or polyester (PET) resin, and the second component sheath is polyethylene (PE) in which 1 to 30% by weight of a low-melting polyester resin is mixed. as,
The low-melting polyester resin is an acid component composed of terephthalic acid or an ester-forming derivative thereof, and a diol component composed of 2-methyl-1,3-propanediol, 2-methyl-1,3-pentanediol, and ethylene glycol. A heat-adhesive composite fiber with improved bendability, characterized by being formed.
According to claim 1,
The composite fiber is a heat-adhesive composite fiber with improved bendability, characterized in that the first component and the second component have a weight ratio of 80:20 to 20:80.