JPS58191215A - Polyethylene hot-melt fiber - Google Patents

Abstract

PURPOSE:The titled fiber that comprises a polyethylene resin composition consisting of a plurality of polyethylene with specific density and different Q values in a specified proportion, thus giving soft-touch nonwoven fabrics, when mixed with other fibers and subjected to hot-melting. CONSTITUTION:The objective fiber is obtained using alone a polyethylene resin composition consisting of (A) 50-100wt% of a polyethylene with a density of 0.910-0.940g/cm<3>, a Q-value of less than 4.0, calculated as Q=Mw/Mn where Mw is weight-average molecular weight and Mn is number-average molecular weight, and of (B) 50-0wt% of another polyethylene with a density of 0.910- 0.930g/cm<3> and a Q-value of more than 7.0, or using the composition as a component for the conjugation so that the composition is exposed to at least a part of the fiber surface continuously. The other component for conjugation is preferably polypropylene.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a polyethylene heat-adhesive line m, and more particularly to a polyethylene heat-adhesive line mK made of a specific polyethylene resin composition.

In the production of nonwoven fabrics, methods for adhering fibers to each other include a method of interlacing fibers such as a needle punch method, or a method of using various adhesives (binders). In recent years! .

Nonwoven fabrics with high elongation for sanitary and medical purposes are required to have a soft feel, low basis weight, high strength, and time running properties, and nonwoven fabrics made by the binder method have mainly been used. The mainstream binder method has been to crush the web in an adhesive solution (or emulsion) or to spray the solution onto the web. For improvement etc.
A method in which a relatively low-melting-point O powder or fibrous solid is mixed with nonwoven material fibers and the fibers 114 are bonded by heat treatment is becoming increasingly used. In particular, the fibrous binder has excellent characteristics such as being able to be uniformly mixed with the O#I fibers of the nonwoven fabric, facilitating paper making, and having a high yield.

The properties required of the binder fibers for nonwoven fabrics for the above applications are: 1) In order to maintain the heat resistance of the nonwoven fabric, the melting point should be 100°C or higher, 2) In order to keep the heat treatment cost for fusion low, The melting point is preferably 140°C or lower. Conventionally used adhesives for adhesive bonding include those made of low melting point polyester, polypropylene, or polyethylene, but among these, polyethylene is the only one that can come close to meeting the above requirements. however,
Polyethylene, which is usually used in the form of fibers, has a density of 0.9
It is a high-density polyethylene with a molecular weight of 50 to 0.970, has a high degree of crystallinity, and has the disadvantage that the texture of the nonwoven fabric obtained by thermal bonding treatment tends to become hard. On the other hand, low-density polyethylene has low rigidity and can be expected to have a soft texture, but it has poor spinnability and stretchability, and therefore
Only monofilaments as thick as d/fll& or more can be obtained, and the above-mentioned requirement of 1.5 to 6 d/f cannot be met, so they are mainly used in powder form.

As a result of intensive research to overcome the above-mentioned drawbacks of polyethylene, we developed a polyethylene with a density of 0.910 to 0.940 t 1
Exa has a q value of 4.0 or less O polyethylene/(sometimes abbreviated as polyethylene)) 50 to 100 weight and 11 degrees is 0.910 to 0.93 Of/ffi”
A polyethylene resin composition (hereinafter sometimes abbreviated as "resin composition") consisting of polyethylene (hereinafter sometimes abbreviated as polyethylene (b)) with a q value of 7.0 or more (hereinafter sometimes abbreviated as polyethylene (b)) with a weight of 50 to 0. has excellent spinnability, and the resin composition (
0) or a wrinkled resin composition (a composite fiber in which Q is a part of the composite component and the wrinkled resin composition (B) forms at least a continuous portion of the fiber surface) can be used as a heat-fusion bonding binder fiber. The present invention was completed after discovering that the present invention can be preferably used.

The polyethylene used in the present invention) can be obtained by coordinating ethylene with an α-olefin having 4 to 8 carbon atoms as a copolymerization component in the presence of catalyst #IO, and is obtained by coordinating anionic polymerization of ethylene in the presence of #IO,
It can be selected from those commercially available as LDPR. Polyethylene (b) used in the present invention
can be obtained by polymerizing ethylene by a radical reaction in the presence of oxygen or peroxide under high pressure of 1,000 to 3,000 atmospheres, and can be selected from those commercially available as LDPI.

In the present invention, the reason why the concentration of polyethylene (4) in the polyethylene resin composition (C) is limited to 50-100% by weight and the concentration of polyethylene (B) is limited to 50-0% by weight is that the resin composition (C) If the concentration of the polyethylene body in C) is less than 50% by weight (i.e., the concentration of polyethylene in the polyethylene exceeds 50% by weight), the spinnability and stretchability of the resin composition (C) will deteriorate. This is because stable spinning operations cannot be performed.

For mixing the above-mentioned polyethylene body) and polyethylene (b), any known O mixing method that is usually used for mixing thermoplastic resins can be used. A method of mixing (2) and (2) using Ribbon Pregu or Henschel Mikina,
Furthermore, powdered or pelleted polyethylene)
An example is a method in which (b) is mixed and granulated using an extruder. Polyethylene resin composition (0) K contains stabilizers, colorants, fillers, etc. that are usually added to polyethylene.
Ii light 01 can be added within a range that does not cause any damage.

The polyethylene resin composition (b) thus obtained can be spun by itself, or can be composite spun together with other O-fiber-forming resins.

Examples of other fiber-forming resins that can be used include high-density polyethylene, polyester, and polyester. Composite form is 4j, either parallel type or axis IIO
However, in order to utilize the thermal adhesion effect of polyethylene resin composition (to) O, in the case of parallel type, wrinkle resin composition (0
) must be arranged so that at least a portion of the fiber surface is continuously formed, and in the case of a sheath-core type, the resin composition (C) must be arranged as a sheath component.

In the case of single spinning, the spinning temperature is 200-300°C and the draft rate is 400-1200. Pickup speed 500-1000
When spinning at a speed of m/min and stretching at a drawing temperature of 60 to 110° C. and a draw ratio of 2 to 6 times, a polyethylene thermoadhesive fiber of 1.5 to 6 denier can be stably obtained from K. In the case of composite spinning, the spinning and stretching conditions vary depending on the partner components to be composited, but the polyethylene resin composition aik (
The spinning temperature for the 0) side is suitably 200 to 300°C, and the spinning and drawing properties of the other component other than the spinning temperature may be set according to the conditions for the above-mentioned single spinning.

The polyethylene heat-adhesive fiber of the present invention is mixed and molded with fibers constituting a nonwoven fabric by a method such as a wet paper-making method or a carding web method, in the same way as the conventionally known pine-goo fiber, Fibers that make up nonwoven fabrics by heat treatment at a temperature of 130 to 140°C using a method such as a hot roll include natural fibers such as pulp, cotton, and wool, viscose rayon, polyolefin fibers, polyester fibers, and polyamide fibers. One or more types of chemical fibers such as these can be selected and used as appropriate depending on the intended use of the product nonwoven fabric. The amount of the polyethylene heat-adhesive fiber of the present invention mixed with the fibers constituting the nonwoven fabric is as follows:
A weight of 10 weight or more is required for a delicate nonwoven fabric after mixing, and a weight of 30 weight or more is preferable when a high strength nonwoven fabric is required.

When the polyethylene heat-adhesive fiber of the present invention is a composite fiber, it can be used to form a web by itself, and the low single-point component (
By heat-treating at a temperature higher than the melting point of the polyethylene resin composition (O) and lower than the melting point of the high melting point component (composite component), a nonwoven fabric can be obtained without mixing with other types of fibers.

Since the polyethylene heat-adhesive fiber of the present invention is delicate, it can be easily and uniformly mixed with other types of fiber, and
Because the fineness is small, the bonding points are small, and because the rigidity is low, it is possible to obtain a nonwoven fabric with a soft texture.Furthermore, because the melting point is low, it exhibits strong adhesive force at relatively low heat treatment temperatures, reducing energy costs. It has a number of excellent properties that make it possible.

The present invention will be further explained by Examples and Comparative Examples. The tests and evaluation methods used on each side are as follows.

Spinning test □ Single spinning Two pellets of specified polyethylene (A) and polyethylene CB) are mixed at a specified weight ratio using a tumbler mixer and fed to an extruder for spinning. Using a 240-hole spinning nozzle and an extrusion lid at about 130 f/min, the yarn is spun to obtain an undrawn yarn, which is subsequently stretched to a predetermined magnification using a hot roll method.

Composite spinning: Polyethylene)) and (B) are mixed in the same manner as above, fed to one of the extruders for composite spinning, and the amount of extrusion is adjusted according to a predetermined composite ratio. Spinning and drawing were performed using a parallel type or sheath-core type spinneret under the same conditions as for single spinning except for the following.

Evaluation of spinnability was evaluated based on the number of yarn breakages of undrawn yarn after one hour of spinning, and was expressed as 20 for zero times, 20 for one time, Δ for 2 times, and × for 3 or more times.

Stretchability evaluation = Excellent if no single yarn breakage occurred during 1 hour of continuous operation, Good if single yarn breakage occurred 3 times or less, Frequent single yarn breakages caused the yarn to wrap around the stretching roll and stop operation. 1
Those that occurred at @ or above were evaluated as not acceptable and were marked with ◎, 0, and ×, respectively.

Non-woven fabric test Calendar roll method: The fibers constituting the non-woven fabric and polyethylene heat-adhesive fibers are mixed, and a web with a predetermined basis weight is made using a flat card. / scratched metal rolls at a speed of 6s*/win to form a non-woven fabric.

Dryer method: A web was prepared in the same manner as the calendar method, and this web was heated for 5 minutes using a hot air circulation dryer adjusted to a predetermined temperature to form a nonwoven fabric.

Paper-making method: The mixed raw fibers were made into a wet sheet using a hand-containing testing machine, and this sheet was passed through a Yankee dryer with a diameter of 301 mm at a predetermined temperature at a speed of 1 m/min to dry and heat-treat it to make it into a non-woven fabric. .

According to the tensile strength and elongation test method of Tensile Strength Kani J-S L1085 (Test method for non-woven fabric stains), width 551
1. Hold a sample of length 201 at intervals. −; i minus, speed per minute. ±22 f III constant.

Ta.

Texture evaluation: Using the same nonwoven fabric constituent fiber as each side, a nonwoven fabric bonded with polyvinyl acetate adhesive instead of polyethylene thermal adhesive fiber was used as a control example, and was evaluated by a total of 5 panelists, 3 boys and 2 girls. - evaluated by a sensory test, and a majority of panelists judged that the texture was better than the control example.
1. Those that were considered to be on par with the control example were indicated as ◯, and those that were inferior to the control example were indicated as ×.

Examples 1-4, Comparative Examples 1-4 1-1! ! ! (as shown in various polyethylenes)
and polyethylene (b), polyethylene resin compositions having different mixing ratios were obtained, and polyethylene fibers were obtained under the spinning conditions and ground conditions shown in Section 1-2fi. Evaluations of the spinnability and stretchability of each polyethylene resin composition are also shown in No. 1-29.

The polyethylene fibers were cut into short fibers, mixed with other types of fibers, and heat treated to obtain a nonwoven fabric. The mixing conditions, nonwoven fabric conditions, and properties of the obtained nonwoven fabric were
It is shown in Table 3.

GL-1 Table 1-2! II! Examples 5-9. Comparative Examples 5 to 7 Polyethylene composite fibers were obtained by combining various fiber-forming resins with polyethylene resin compositions made of various polyethylenes (A) and polyethylene CB).・
The composition of the polyethylene resin composition, the composite components combined therewith, the composite form, and the composite ratio are shown in Table 2-1, and the spinning conditions, stretching conditions, spinnability evaluation, and stretchability evaluation are shown in Table 2-2.
Each is shown in the table.

After cutting the above polyethylene composite fiber into short fibers,
It was mixed with other types of fibers and heat treated to obtain a nonwoven fabric. The mixing conditions, nonwoven fabric forming conditions, and properties of the obtained nonwoven fabric are shown in Table 2-3.

Table 2-2 and others: Other composite components No. 2-32 As is clear from the results of each of the above, the polyethylene heat-adhesive fiber of the present invention has excellent spinnability and earthiness, and it is By using it as a nonwoven fabric, it is possible to economically obtain a nonwoven fabric with excellent strength and texture.

that's all

Claims (1)

[Claims] 0) Density is 0.910 to 0.940 r/cm!
-t', Bolithere having a Q value (Q -My/Mn) of 4.0 or less/(A) 50 to 100% by weight and a density of 0.
910 to 0.930 f/wound 3, consisting of polyethylene resin composition (0) consisting of polyethylene (b) having a Q value of 7.0 or more and 50 to 0 weight, or,
A polyethylene heat-adhesive fiber comprising a wrinkled resin composition (C) as a part of the composite component, and the resin composition (0) continuously forming at least a part of the fiber surface. (2) Claim No. α in which the other component to be combined with the polyethylene resin composition (0) is polypropylene
) The polyethylene heat-adhesive fiber described in item ).