JPS62299511A - Polyamide-polypropylene based fiber - Google Patents

Abstract

PURPOSE:To obtain an inexpensive fiber for carpet excellent in abrasion resistance, fatigue resistance, etc., by blending a polyamide-based resin with a special modified polypropylene and melt-spinning the blend. CONSTITUTION:A resin composition is obtained by blending 97-70wt% modified polypropylene prepared by adding 0.05-2wt% unsaturated carboxylic acid (e.g. acrylic acid, methacrylic acid, maleic acid, etc.) or anhydride thereof to a crystalline polypropylene or ethylene-propylene copolymer with 3-30wt% polyamide resin (e.g. nylon 6, nylon 66, nylon 6, 10, nylon 11, nylon 12, etc.). The resin composition is melt-spun single or with other component to respectively give a single fiber side-by-side type or core-sheath type conjugated fiber.

Description

[Detailed Description of the Invention] 3. Detailed Description of the Invention (Field of Industrial Application) The present invention provides a fiber that has physical properties suitable as a main fiber of a nonwoven fabric for sanitary materials, a heat-fusible fiber, and a fiber for carpets. Polyamide/polypropylene fibers 11

(Conventional technology and problems) Polypropylene fiber is hydrophobic, hygienic and harmless.

Due to its low specific gravity, suitability for coloring with a undiluted solution, and relatively low price, it is frequently used as a nonwoven fabric IJAM for various sanitary materials, or as a filament yarn for needle punch carpets and tufted carpets.

By the way, in the field of nonwoven fabrics used as surface materials for disposable diapers and menstrual napkins, soft feel and dimensional stability during nonwoven fabric processing are required.On the other hand, in the field of carpets, nylon is used as a raw material. Compared to carpet made from yarn, the abrasion resistance or creep resistance of the raw yarn is inferior to that of nylon, and as a result, the disadvantages are that the 17Q of the carpet is short, and the carpet tends to wear out easily or leave marks when heavy objects are placed on it. Improvements in these areas are strongly desired.

In addition, there is a method for producing a nonwoven fabric by blending main fibers with heat-fusible fibers in an appropriate ratio and bonding the fibers by heat-fusion.

There are two types of thermal FIA adhesive fibers: those with a single-component fiber structure and composite fibers with an M4 or sheath-core structure made by laminating multiple components. In order to maintain the fiber form, the fibers are heated to a temperature above the softening point and below the melting point, then pressed using point seals or embossing rolls and then cooled.For composite products, one component is made of a high-melting point material. Therefore, the fiber form can be maintained below this melting point, and it is possible to fuse with hot air depending on the melting point of the low melting point component, and in this case, a high quality nonwoven fabric can be obtained.

However, conventional single-component and composite-component heat-fusible fibers suffer from large thermal shrinkage when heated to their softening point during heat-fusion, resulting in uneven products. To suppress this, methods include using undrawn fibers or blending polyester polymers with good heat resistance (Japanese Patent Laid-Open No. 6
0-39412) has also been proposed, but there are problems in that the former has low fiber strength and the latter cannot provide stable spinnability.

As a way to solve the various problems mentioned above, attempts have been made to blend nylon-based polymers with polypropylene, as nylon fibers have excellent flexibility, abrasion resistance, and heat resistance. If a resin mixture is melt-spun, stable spinnability cannot be obtained due to poor compatibility.

In view of the above-mentioned problems, the present inventors created a polypropylene-based product that has the characteristics of polypropylene and also has the flexibility, heat resistance, abrasion resistance, creep resistance, etc. of polyamide resin! As a result of intensive study on how to improve the quality of fibers, the present invention has been completed.

(Means for Solving the Problems) In order to solve the above problems, the present invention provides crystalline polypropylene or ethylene-propylene copolymer with an unsaturated carboxylic acid or its anhydride. %
97 to 70% by weight of modified polypropylene added,
The present invention is characterized in that the composition is prepared by mixing 3 to 30% by weight of a polyamide resin alone, or the composition is used as at least one component of a composite fiber having a parallel type or sheath-core type structure.

The polypropylene that can be used in the present invention is one having an isotoughness in which the n-heptane insoluble content is 85% or more, or a random copolymer with an ethylene content of 4IfQ% or less, or a block with an ethylene content of 7% or less. Examples include copolymers.

To this, 0.05 to 2% by weight of unsaturated carboxylic acids such as acrylic acid, methacrylic acid, maleic acid, fumaric acid, itaconic acid, citraconic acid, etc., or anhydrides thereof are added. The ratio of the unsaturated carboxylic acid or its anhydride to 100 parts of crystalline polypropylene is preferably 0.05 to 2.0 parts, and the peroxide as a reaction initiator is 5 to 1.0 parts.

In addition, examples of the above-mentioned peroxides include tertiary butyl hydroperoxide, ditertiary butyl peroxide, dicumyl peroxide, and benzoyl peroxide. Alternatively, 50% by weight or less of unmodified polypropylene may be blended with polypropylene modified with an unsaturated carboxylic acid so that the unsaturated carboxylic acid content is 0.05 to 2.01 ffi% as a whole.

If the amount of unsaturated carboxylic acid added is less than 0.05 D%, the compatibility with the polyamide resin is poor and good spinnability cannot be obtained, and if it is more than 3 D%, a gel-like substance is generated and good spinnability is not obtained. I also color it.

In addition, polyamide resins that can be used in the present invention include:
Nylon-6, Nylon-6,6, Nylon-6,10
, nylon-11, nylon-12, etc., and the addition a of these is preferably 3 to 301%, and the blending amount is 3.
If it is less than 1% by weight, sufficient physical properties such as flexibility, heat resistance, abrasion resistance, and creep resistance cannot be obtained, and if it is more than 31% by weight, the appropriate spinning temperature becomes high and the pigment may be thermally decomposed.
It is undesirable because hue unevenness occurs due to retention in the spinning machine, frequent spun breakage occurs, and when used in nonwoven fabrics, the tearing length is low and the surface feels sticky.

(Example) Hereinafter, the present invention will be explained in detail with reference to Examples.

・Examples 1 to 4 Polypropylene homopolymer (MI=15>100 parts with maleic anhydride superimposed, 0.1.0°5.1.5,
2.0 parts, and tertiary butyl hydroperoxide, each by weight 0.03゜0.1.0.2.0.25
The two parts were mixed at room temperature in a Henschel mixer, and the mixture was fed to an intermeshing twin-screw extruder and pelletized at 210°C to obtain modified polypropylenes A, B, C, and D.

Each modified polypropylene is coated with nylon 6 (relative viscosity 2.
6) was added at 3.10.20.30% by weight and mixed with stirring, and this was fed to a spinning machine equipped with a nozzle with a hole diameter of 0.6+v and a number of holes of 200, at a spinning temperature of 270°C and a take-up speed of 8.
The yarn was spun at 00 m/min to obtain an undrawn yarn with a single yarn denier of 6.0 to 6.2. A predetermined number of these undrawn yarns are bundled together at 90°C.
After stretching to 4 times with
The fibers were cut into 1.5 d long staple fibers for nonwoven fabric.

In these Examples, good spinnability and stretchability were obtained.

・Comparative Examples 1 to 3 Using the same polypropylene as in the above-mentioned examples, modified polypropylenes E, F, and G with a smoothness of 0.04%, 0.1.2%, and 0% maleic anhydride were obtained. nylon-6
When spinning was carried out under the same conditions as Examples 1 to 4 using a raw material composition of 5% by weight, 1% by weight, and 35% by weight, the dispersibility of nylon was There were many spun breaks, probably due to poor quality.

・Examples 5 to 7 Polypropylene with an iso-toughness (I) of 94% and 2.5% lower culm than normal iso-toughness, and an ethylene-propylene random copolymer with an ethylene content of 1% by weight A raw material prepared by combining this ethylene-propylene copolymer and polypropylene with an isotoughness of 96.5% is modified by adding 0.5% by weight of maleic anhydride, and each of these raw materials is modified with 10% of nylon-6.
2 deX 51 Im in the same manner as above with addition of
A staple fiber miscellaneous material for nonwoven fabrics was obtained. These HrM
had a higher Young's modulus and better card passing properties than iIN which is unmodified and does not contain nylon-6, which will be described later.

・Comparative Examples 4 to 6 ■Polypropylene homopolymer with isotacticity of 94%, which is about 2.5% lower than ordinary products ■Ethylene-propylene random copolymer (ethylene 1%) ■Ethylene-propylene random copolymer (ethylene 1%)
%) and polypropylene homopolymer (isotoughness 95.6%) in a 1:1 blend. Ml is 15 in both cases.

Using raw materials from ■ to ■, spinning temperature 270℃, single yarn denier 8. An undrawn yarn with a total denier of 1600 was obtained. This undrawn yarn was four-way stretched in the same manner as in Examples 1 to 4, crimped and cut to make staples, and the heat shrinkage rate was measured, and was very large at 20 to 45% at 140°C.

Therefore, the single yarn denier of the undrawn yarn was set to 5, stretched 2°5 times, crimped and cut to obtain 2 dex 511II.
Ill staples were obtained.

The fiber quality of this staple has a strength of 2.5.3° and 0.3° respectively.
．． O(1/d, Young's modulus is 71.6, which is lower than that of the example.
It was as low as 0.51 part M-.

The physical properties of the fibers of Examples 1 to 7 and Comparative Examples 1 to 6 are summarized in Table 1 below.

- Examples 1' to 4 - Nonwoven fabrics were made by point-sealing the fibers of Examples 1>fjlIA1 to 4 above.

The fibers obtained in Examples 1 to 4 above were processed using a 350 mm wide sample card machine (manufactured by Yamato Kiko) with a fabric weight of 20 CI/
+n' wear, seal surface v18%, seal solution pressure 5
k! ll/cm, surface temperature 132℃, sealing speed 5
It was made into a nonwoven fabric by passing it through a roller type point sealing machine of m/min.

Examples 1 to 4' in which 3% to 30% of nylon-6 was mixed
The nonwoven fabric had no problems with shrinkage, tear length, and texture and was excellent.

- Comparative Examples 2 to 3' The fibers of Comparative Examples 2 to 3 above were point-sealed and made into nonwoven fabrics.

The fibers obtained in Comparative Examples 2 and 3 were used in Examples 1' and 2, respectively.
A nonwoven fabric was obtained by point sealing in the same manner as 4'.

As a result, a nonwoven fabric containing 1% nylon-6 had a heat shrinkage rate of more than 30%, resulting in a non-uniform and wrinkled nonwoven fabric, and a nonwoven fabric containing 35% nylon-6 had a tearing length of 1%.
There is no 609mb and the surface feels sticky.

The physical properties of the nonwoven fabrics of Examples 1' to 4' and Comparative Examples 2 to 3 are summarized in Table 2 below.

・Example 8.9 Using composite fiber manufacturing equipment, the same polyamide polypropylene resin as in Example 3 was used as the high melting point resin, and high density polyethylene (J631 manufactured by Tonen Petrochemical ■) was used as the low melting point resin.
1 MI=12) for sheath-core type (Example 8) and laminated type (Example 9) composite system adhesiveness! 1 fiber was spun.

The stretching ratio was set to 4 in each case, and a stable fiber of 2d×51111111 was obtained by crimping and cutting.

From this stable, 200
/Create a T112 wear and make this web with a width of 350
mm, placed on a wire mesh belt with a speed of 5 m/a + in, and an air temperature of 1
Hot air was fused by blowing hot air at 37°C and a wind speed of 2 m/sec for 5 seconds. What is the heat shrinkage rate of the obtained nonwoven fabric? Director J is listed in Table 2.
As shown in the figure, the shrinkage was small and the fracture length was large. The reason why the tearing length was large is considered to be due to the strong adhesive strength between the modified PP and the IDPE.

Comparative Example 7 As a comparison of Example 8.9 above, polypropylene homopolymer (Ube Industries ■tjJ115G MI) was used as a high melting point resin.
When a circumference test was conducted using a sheath-core type composite system viewing mH using (=15), the shrinkage rate was larger than that of the example.
The nonwoven fabric was non-uniform due to uneven shrinkage.

In addition, in cases where the tearing length is smaller than that of the examples, microphotograph observation shows that PP and HOPE have peeled off.
) (This is thought to be due to the weak adhesive strength of DPE.

- Examples 10 to 13 Nylon-6 (relative viscosity 2.6) was added to 97 to 70% of the modified polypropylene of Examples 1 to 4 at 3°10.20%.
30% by weight, 0.5% of yellow i pigment (Pv Far Yellow HR manufactured by Hoechst) per 100 parts of these.
The blended pigment mixture was fed to a spinning machine equipped with a 30-hole nozzle and spun at a take-up speed of 800 II/min.
A single undrawn yarn of 18 denier was obtained. This undrawn yarn
It was stretched 4 times at 0° C. to obtain 1 q of 4.5 denier carpet fiber.

When this fiber was examined for its abrasion resistance, creep resistance, and recovery properties using the methods described below, all excellent results were found.
I was pissed.

・Comparative Examples 10 to 13 Using modified polypropylene with maleic anhydride addition m of 0.1 or 2.0% by weight, and mixing nylon-6 as a polyamide resin at 0.1.35°1001% by weight,
Spinning under the same conditions as Example 1.

Stretched. When 35% by weight of nylon-6 is added,
Hue unevenness due to thermal decomposition of the pigment was observed from about 30 minutes after the start of spinning.

Furthermore, in the case of 100% nylon, the hue faded immediately after the start of spinning, and in the case of 100% polypropylene, the abrasion resistance, creep property, and recovery properties were even worse.

In addition, in Comparative Examples 12 and 13, when spinning at 230° C. due to the temperature restriction of the added face r1, thread breakage occurred eight or more times per hour.

Each of the above Examples 10 to 13 and Comparative Examples 10 to 13
The physical properties of H are summarized in Table 3.

- Examples 10' to 13 - Carpets made from fibers having raw material compositions corresponding to Examples 10 to 13.

Raw materials having the same composition as in Examples 10 to 13 were supplied to a bulky textured yarn production machine in which spinning and crimping were directly connected, and the drawing roller speed was 1500 m/min, the drawing ratio was 3 times, and the air jet
A crimped continuous yarn of 20 dx60 filaments was obtained by a crimping method using a needle cloth drum.

All had good spinnability, and no change in hue was observed due to spinning.

Twist two of these 20d x 60 filament crimped continuous yarns and make a fabric weight of 400 (1
/m' pile carpet was created.

The abrasion resistance and settling resistance of this pile carpet,
(2) When the thickness reduction rate and the thickness reduction rate were examined, they were superior to the comparative examples described below, and the values were satisfactory.

- Comparative Examples 10-13- Carpets were made from ialM having raw material compositions corresponding to Comparative Examples 10-13.

Pile carpets were made using Ig fibers having the same raw material composition as in Comparative Examples 10 to 13 in the same manner as in Examples 10' to 13-, and the same tests as in Examples 10' to 13' were conducted.

As a result, Comparative Example 12-. 13- has a large proportion of nylon-6, so yarn breakage occurs more than 5 times/hour when spinning at 230°C, and the temperature at which stable spinning is possible is 250°C.
The temperature was 280°C, and uneven hue or fading was observed at this time.

Further, the tufted carpet made of raw yarns according to Comparative Examples 10 and 11 had a large overlay reduction rate and a large thickness reduction rate, and was inferior in performance.

Examples 10'-13' and Comparative Examples 10'-13 above
Table 4 summarizes the physical properties of -.

The physical properties were evaluated using the following method.

・Abrasion resistance test of m-fiber: As shown in Figure 1, short m-dark blue was applied to the rotating roller, and 0°2 (+/
A load of d is applied and the roller is rotated in the opposite direction to the load.

Two types of waterproof sandpaper, 100 mesh and 320 mesh, were attached to the roller surface for testing. The measured value was expressed as the number of cases that resulted in cutting.

The number of samples tested was 30 in each case.

・Creep property and recovery property of iIN; In an atmosphere of 20°C and 65% relative humidity, the
Apply an initial load of 2 mQ/de to the On+m single Jllllt, and mark the middle part at intervals of 400111 m with the thread taut. Then, 24 hours after applying a load of 1 (1/de), measure the mark interval and calculate the strain (%).
After the static load, the initial load is 2 m (J/ de in h
2) The mark interval at the time point of 24R was measured to determine the residual strain (%).

・Carpet abrasion resistance test: According to JIS L-10215, 12 method, abrasion resistance is H
-38, load is 1kL on one arm, rotation speed is 7Q rpm, 5
Rub it 000 times. The reduction after friction is measured and expressed as the average value. In addition, the reduction rate with respect to the pile unit weight corresponding to the T9 gap area was also calculated and expressed as the average value. J3, yo) The number of fixed times was set to 5.

・Thickness reduction rate due to dynamic load of carpet; JIS
According to the L-10215,11 method, the impact rotor was a rubber roll (H8-60), the load was 1 ko, the rotation speed was 70 rpII, and it was rubbed 10,000 times. after that,
After leaving it for 5 minutes, apply 20
(Apply a pressure of 1/c/ and measure the thickness after 30 seconds, and calculate the rate of decrease in thickness from the thickness before friction.

(Effects of the Invention) As explained in detail in the Examples above, the fiber of the present invention is made of polypropylene modified by adding an unsaturated carboxylic acid or its anhydride to crystalline polypropylene or ethylene-propylene co-ester. Since various types of polyamide resins such as nylon are mixed and melt-spun, unlike the conventional case where polypropylene and polyamide resin are simply mixed, compatibility with the polyamide resin is improved, resulting in stable spinning. This makes it possible to add the excellent physical properties of polyamide resins.

For this reason, carpet fibers with excellent abrasion resistance and sagging properties are made of 100% polyamide-based resin.
Compared to textiles, for example, the optimal spinning temperature for nylon is 260 to 280°C, and in order to add pigments in this spinning process, pigments that have heat resistance of 260 to 280°C or higher must be used. Considering that coloring of nylon f[ mainly relies on dyeing, since not only is it expensive but also colors are limited, the present invention improves the economical cost of coloring and the coloring process. It is superior to polyamide fibers in terms of ease of fabrication.

[Brief explanation of drawings]

Figure 1 shows the fiber 'tf4I! Explanatory diagram of the abrasion test, 2nd
The figure is an explanatory diagram of a fiber creep property and recovery property test.

Claims (1)

[Claims] Adding 0.05% of unsaturated carboxylic acid or its anhydride to crystalline polypropylene or ethylene-propylene copolymer
Modified polypropylene 97-70 with addition of ~2% by weight
% by weight and 3 to 30% by weight of a polyamide resin, or the composition is used as at least one component of a composite fiber having a parallel type or sheath-core type structure. Polyamide/polypropylene fiber.