KR102564977B1 - Heat-Adhesive Composite Fiber With Improved Bendability - Google Patents

Abstract

The present invention relates to a heat-bonded composite fiber with improved bendability, wherein the first component core portion of the composite fiber is any one of polypropylene (PE) or polyester (PET) resin, and the second component sheath portion is polyethylene (PE). 1 to 30% by weight of a low-melting polyester resin is mixed, and the low-melting polyester resin contains an acid component composed of terephthalic acid or an ester-forming derivative thereof, and 2-methyl-1,3-propanediol, 2- It relates to a heat-bonded conjugate fiber with improved bendability characterized by being formed of a diol component consisting of methyl-1,3-pentanediol and ethylene glycol.

Description

Heat-adhesive composite fiber with improved bendability {Heat-Adhesive Composite Fiber With Improved Bendability}

The present invention relates to an olefin-based thermally bonded composite fiber to which a technology for enhancing the stiffness of a nonwoven fabric is applied so as to improve the bendability of the nonwoven fabric for a filter.

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

These air filters are divided into automotive air conditioner filters and air conditioning air filters according to their intended use.

In particular, the automotive air conditioner filter filters 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 vehicle's air conditioner, heater, or engine room to provide clean air to the vehicle interior. Its importance is gradually increasing as it plays a role in influencing

In general, for filters, olefin materials have good static electricity imparting efficiency, but olefin composite fibers have poor filter bendability compared to polyester composite fibers.

Filters are characterized by higher filter efficiency as the bendability is better, so if the bendability of the olefin-based siscore composite fiber is increased, its utilization can be increased.

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

An object of the present invention is to provide a nonwoven fabric filter composed of PE/PP or PE/PET sheath core composite fibers and having excellent bendability.

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

In addition, the present invention provides a heat-sealed 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.

As described above, the present invention is composed of PE / PP or PE / PET sheath core composite fibers, and a low melting point polyester resin is included in the polyethylene of the sheath portion, and the nonwoven fabric made of the composite fibers has excellent bendability, static electricity and filter efficiency It has a characteristic.

Hereinafter, preferred embodiments of the present invention will be described in detail. First of all, in describing the present invention, detailed descriptions of related known functions or configurations are omitted in order 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 approximating that number when manufacturing and material tolerances inherent in the stated meaning are given, and are intended to convey an understanding of the present invention. Accurate or absolute figures are used to help prevent exploitation by unscrupulous infringers of the disclosed disclosure.

As used herein, the terms about, substantially, etc., of degree, are used at or close to the value when manufacturing and material tolerances inherent in the referenced meaning are given, and are used in an accurate or Absolute numbers are used to prevent exploitation by unscrupulous infringers of the stated disclosure.

The present invention relates to thermally bonded composite fibers with improved bendability.

The first component core portion of the composite fiber is any one of polypropylene (PE) or polyester (PET) resin, and the second component sheath portion is polyethylene (PE) mixed with 1 to 30% by weight of a low melting point polyester resin. It has a characteristic.

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

Alternatively, the first component polyester (PET) resin is a condensation polymer of aromatic dicarboxylic acid and glycol, and is 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 is 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 part may use 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 melt flow index (MI, Melting Index) is not particularly limited, but the flow index is 1 to 100 g / lO min, more preferably 5 to 40 g / 10 min. it would be preferable

In the second component sheath, 70 to 99% by weight of polyethylene (PE) is mixed with 1 to 30% by weight of a low melting point polyester resin.

The low-melting polyester resin is an acid component composed of terephthalic acid or an ester-forming derivative thereof, and 2-methyl-1,3-propanediol, 2-methyl-1,3-pentanediol It is formed of 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 the rotation of the polymer main chain and acts as if it were a polymer end, thereby providing 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 chain present in the polymer main chain, it improves elasticity and improves the tear property during binding to nonwoven fabric.

That is, 2-methyl-1,3-propanediol is formed by adding methyl to the ethylene chain bound to terephthalate.

By including a group (-CH3) as a side chain to secure space for rotation of the main chain of the polymerized resin, the degree of freedom of the main chain is increased and the crystallinity of the resin is reduced, thereby increasing the softening point (Ts) and/or glass transition temperature (Tg). ) can be adjusted. This may exhibit the same effect as the case of using isophthalic acid (IPA) containing an asymmetric aromatic ring in order to lower the crystallinity of a conventional crystalline polyester resin.

Like 2-methyl-1,3-propanediol, the 2-methyl-1,3-pentanediol has a methyl group bonded to the second carbon to facilitate rotation of the polymer main chain and to impart low melting point characteristics to the polyester resin. It has a longer molecular chain than 2-methyl-1,3-propanediol, which increases the melt viscosity of the polyester resin and prevents the melt viscosity from rapidly decreasing at high temperatures.

The low melting point polyester resin of the present invention formed of the diol component as described above is 20 to 50 moles of 2-methyl-1,3-propanediol of the low melting point polyester resin in order to improve the low melting point property and adhesiveness % will be preferred.

When the 2-methyl-1,3-pentanediol is contained in less than 001 mol% of the diol component, the effect of improving the melt viscosity is insignificant, and when the 2-methyl-1,3-pentanediol is contained in the diol component, the melt viscosity increases rapidly and the spinning processability may deteriorate. 2-methyl-1,3-pentanediol may preferably contain 0.01 to 5 mol% of the diol component.

It is most preferable that the 2-methyl-1,3-pentanediol contains 0.05 to 2 mol%.

The low melting point polyester resin containing the 2-methyl-1,3-pentanediol is 220 ℃

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

The lower the difference between the melt viscosity of the low-melting polyester resin at 220° C. and the melt viscosity at 260° C., the lower the better.

As described above, the low melting point 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 50 ℃ to 90 ℃, it has excellent physical properties with an intrinsic viscosity of 0.50 dl / g or more.

In addition, it is preferable that the composite fiber is formed in a weight ratio of 80:20 to 20:80 between the first component and the second component.

Hereinafter, an example of a method for producing a heat-bonded conjugate fiber with improved bendability according to the present invention is shown, but the present invention is not limited to the examples.

Example 1

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

The melted 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 fibers spun at a temperature higher than the glass transition temperature of polyethylene terephthalate were stretched and oriented 3.0 to 4.0 times, crimped, and cut to 38 to 64 mm to prepare soft heat-sealed composite fibers according to the present invention.

The prepared composite fiber was made of 60GSM nonwoven fabric and bent to prepare a filter.

Example 2

Same as Example 1 except that the ratio of polyethylene and LM as the second component is 8: 2.

Example 3

Same as Example 1 except that the ratio of polyethylene and LM as the second component is 7:3.

Example 4

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

Comparative Example 1

Same as Example 1 except that the ratio of polyethylene and LM as the second component is 10:0.

Comparative Example 2

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

Comparative Example 3

Same as Example 4 except that the ratio of polyethylene and LM as the second component composition is 10:0.

◈ Evaluation of physical properties of Examples and Comparative Examples

1. Bendability

The composite fibers according to the 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 mountain (∧), 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 considered as 100 points, and the collection rate of the remaining samples was converted into a perfect score of 100 points.

* Gravity 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 passed through the filter.

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

m1: the weight of dust collected by the test filter

m2 : Weight of dust collected in the after filter

3. Pruning machine charge

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

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 2nd
ingredient
(50w%) PE
content 90w% 80w% 70w% 90w% 100w% 60w% 100w% LM
content 10w% 20w% 30w% 10w% 0w% 40w% 0w% bendability
5 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 Static 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 are excellent in bendability of 4.5 or more compared to Comparative Examples 1 to 3, and are also excellent in filter efficiency and static charge.

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

Claims (2)

In the heat-bonded composite fiber with improved bendability,
The first component core portion of the composite fiber is a polyester (PET) resin, and the second component sheath portion is a mixture of 1 to 30% by weight of a low melting point polyester resin in polyethylene (PE),
The polyethylene (PE) is high-density polyethylene (HDPE), and the melt flow index (MI, Melting Index) is 5 to 40 g / 10 minutes,
The polyester (PET) resin is one or a mixture of two or more selected from polyethylene 2,6-dinaphthalate, polypropylene terephthalate, polybutylene terephthalate, and polyethylene isophthalate,
The low-melting polyester resin is composed of 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. Heat-sealed composite fibers with improved bendability characterized by being formed.
According to claim 1,
The composite fiber is a heat-sealed 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.