JPH03165728A - Knit/woven object for cleaning - Google Patents

Abstract

PURPOSE:To obtain a knit/woven object which has an excellent cleaning force for water, oil or solvent and is suitable for cleaning at a production site sensitive to dust by weaving or knitting hydrophilic porous polyolefin fibers communicating a space surrounded by many fibrils from fiber surfaces to the center section with specific porosity. CONSTITUTION:This object is made of hydrophilic porous polyolefin fibers communicating a space surrounded by many fibrils connecting lamellas over the whole from fiber surfaces to the center with a porosity 20-80%. A polymer blended with polyolefin 95-40wt.% and hydrophilic polyolefin 5-60wt.% is used for the polymer. An ethylene copolymer containing ethylene unit 20-99wt.%, one or more types of polyalkylene glycol mono(meta)acrylate unit 80-1wt.% indicated by the formula, and one or more types of ethylene unsaturated monomer unit 0-40wt.% and having a contact angle against water 80 deg. or below in the film state is suitably used for the hydrophilic polyolefin.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a cleaning fabric with excellent cleaning properties and durability.

[Prior art and problems to be solved] Wipers used for cleaning have dust-absorbing properties that absorb dust, dust-retaining properties that trap the sucked-up dust, and liquid-absorbing properties that absorb oil and solvents from the cleaning surface. It is necessary to have excellent cleaning performance such as cleaning properties such as cleaning properties and liquid retention properties that trap absorbed moisture, and also to have excellent durability.

However, conventional wipers are generally made of paper or cloth, and since many of these materials are made of short fibers such as polyester or cellulose, the short fibers are relatively easily frayed by external force. , the fibers tended to easily fall off and generate dust due to repeated sliding when using the wiper. For this reason, in environments where dust is averse, such as electronic product manufacturing sites, the above-mentioned conventional cleaning cloths generate lint and cannot perform complete cleaning.

To compensate for these drawbacks, knitted fabrics made of synthetic R1 fibers are used for cleaning purposes. Generally, the larger the surface area per 1f of fibers (hereinafter simply referred to as surface area), the greater the cleaning power.One way to increase the surface area is to make the single yarn thinner.For example, Japanese Patent Publication No. 59-30419
As shown in Figure 1, there is a method in which splittable conjugate fibers made of hydrophilic and lipophilic polymers are once made into a woven fabric, and then one side of the component is split with a solvent to form single yarns. However, manufacturing such fabrics involves a solvent treatment process, which increases running costs6.
Since it is a combination of a hydrophilic polymer and a lipophilic polymer, the wiping performance of a liquid with high surface tension (for example, water) was inferior to the case of using only a hydrophilic polymer.

The present invention solves these conventional problems and provides a cleaning fabric with excellent cleaning properties and durability.

[Means to solve problems]

The present invention is made from hydrophilic porous polyolefin lj&fiber, which has a porosity of 20 to 80 and has a communication space surrounded by a large number of fibrils connecting lamellae from the surface to the center of the fiber. This is a cleaning fabric.

The polymer used in the present invention includes a blend polymer of 95 to 40% by weight polyolefin and 5 to 60% by weight hydrophilic polyolefin. In this case, polyolefins include polyethylene, polypropylene, poly-3-methylbutene-1/poly-4-methylpentene-
1 etc., and as a hydrophilic polyolefin, the ethylene unit is 20 to 991 ijll, and the 1 shown by the following formula is mentioned.
80 to 1 by weight of the species or two or more polyalkylene glycol mono(meth)acrylate units, and one other
0 to 2 or more ethylenically unsaturated monomer units
The contact angle with water is 8 when the film contains 40 liters by weight.
Ethylene copolymers with an angle of less than 0° are preferably used.

(Here, R1 and R2 are each hydrogen or a methyl group, and n is a number from 2 to 9.) As a method for producing the porous polyolefin fiber of the present invention, first, the polymer is processed using a normal spinneret. Melt spinning is performed to obtain an undrawn yarn.

The spinning temperature suitable for obtaining a porous structure with a porosity of 20 to 80, which is the objective of the present invention, is about 20°C, which is the melting point of the polymer.
In the above, it is preferable to set the temperature in a range that exceeds the melting point of the polymer by about 20°C or more. Approximately 20% higher than the melting point of the polymer
Undrawn yarn spun in a low-temperature region not exceeding ℃ is highly oriented and crystallized, but when drawing to make it porous later according to the present invention, the maximum draw ratio becomes low, and the present invention It is difficult to obtain the intended porous fiber. On the other hand, when spinning is performed at a high temperature of 80° C. or more above the melting point of the polymer, the porosity is significantly reduced.

The polymer discharged at a suitable spinning temperature is 10-10,0
It is desirable to take over at a draft in the 00 range.

The undrawn yarn thus obtained may be drawn as is, but in order to obtain a porous fiber with a high porosity, b, which is below the melting point of the polymer and has a constant length, is stretched in a relaxed state in a vacuum or in an inert gas. It is desirable to carry out annealing treatment in a medium for 2 minutes or more and then stretch.

The stretching may be carried out in one stage, but in order to obtain porous fibers with high porosity, two-stage stretching in which low-temperature stretching is followed by high-temperature stretching is desirable.

In order to reduce the dry heat shrinkage rate of the obtained porous fibers,
If necessary, heat setting may be performed below the melting point under tension or in a relaxed state.

By knitting or weaving the hydrophilic porous polyolefin fibers obtained in this way, the intended cleaning fabric can be obtained.

The present invention will be explained in more detail with reference to Examples below, and various measured values in the Examples were determined by the following methods.

(1) Lint-free performance: Using the apparatus shown in 5.11 of JI8 L-1085, two 10 (Ml square) test pieces and 400 cc of ethanol were placed in a 1 ton container, and the mixture was shaken for 20 minutes. Thereafter, the ethanol was filtered through black paper, and the weight of the filtered lint was measured.

(2) Wipability As dust, carbon black powder with a particle size of approximately 1 μm, water, and kerosene were used, and each was sprinkled on an acrylic board, and evaluated by the size of the wiping residue when actually wiped off.

(3) Water Retention After immersing in water and centrifugally dehydrating at 1000 r, p, m, the weight increase was measured, and the weight of the paired knitted fabric - j) tlJ was determined.

〔Example〕

High density polyethylene with density CL964 f/yH”, melt index 5.0 and ethylene unit 55M
It contains 45 weight units of monomethacrylate units made of polyethylene glycol with an average degree of polymerization of 6, and has an intrinsic viscosity [η] of α15dt/
An ethylene copolymer having a contact angle with water of 55° in the form of a film is blended in a ratio of 4:1 using an extruder, dried at 80°C for 12 hours, and then the nozzle diameter is 1.
Discharge using a nozzle with 0■φ and 40 holes [25f/
min b spinning temperature 160℃, winding speed 250m/mi
It was spun and wound under conditions of n. The obtained undrawn yarn was heat-treated at 115°C for 24 hours in a vacuum while wound around a bobbin, and then cold-stretched at room temperature for 50 times using a drawing/twisting machine, and then stretched at 110°C until the amount of stretching was 216°. Hot stretching was performed. Furthermore, relaxation heat setting was performed at 120°C so that the stretching amount was 200'l. Stretching speed is 240 m/m
The spindle rotation speed was 960 Or, and the winding was carried out on a burner using a pom.

The obtained hydrophilic porous polyolefin fiber had a homogeneous porous structure, a porosity of 524, and a fineness Vi of 500 denier/40 filaments.

After heating and warping the fiber yarn at a twist number of 150 T/M, it was woven into a twill weave using a rapier loom. In this case, the warp density and weft density were both 50 threads/inch.

Table 1 shows the evaluation results of the cleaning power of the fabrics.

Table [Comparative Example 1] High-density polyethylene with a density of α95897 cm and a melt index of 20 was spun using a nozzle with a nozzle diameter of 1L6Mφ and a number of holes of 40, a discharge rate of 15 f/min, a spinning temperature of 170°C, and a winding speed of 800 m/min. It was spun and wound up under the following conditions.The obtained undrawn yarn was stretched in one stage at 80°C using a drawing/twisting machine so that the amount of stretching was 3224 degrees, and then heat-set at 110°C with a roller.Stretching speed is 2
Spindle rotation speed 10,000 r, p at 50 m/min
, m was wound onto the burner.

The obtained polyethylene fibers were smooth and had a fineness of 40 denier/40 filaments.

Using the obtained fiber yarn, weaving was carried out under the same conditions as in the example.

The evaluation results of the cleaning power of the obtained fabrics are also listed in Table 1.

[Comparative Example 2] Evaluation results of a rayon nonwoven fabric with a basis weight of 80 t/m'' are also shown in the t41 table for comparison.

〔Effect of the invention〕

The knitted fabric made of the hydrophilic porous polyolefin fiber of the present invention has excellent cleaning power against water, oil, solvents, etc., and is suitable for cleaning in environments where dust is averse, for example, at electronic product manufacturing sites.

Claims (3)

[Claims] (1) Hydrophilic porous polyolefin fibers with a porosity of 20 to 80% and in which spaces surrounded by numerous fibrils connecting lamellae are connected throughout the fiber from the surface to the center. A knitted fabric for cleaning. (2) The hydrophilic porous polyolefin fiber contains 95 to 40% by weight of polyolefin and 5 to 60% by weight of hydrophilic polyolefin.
2. The cleaning fabric according to claim 1, comprising a blended polymer of % by weight. (3) Hydrophilic polyolefin has 20 to 20 ethylene units
99% by weight, 80 to 80 to 100% by weight of one or more polyalkylene glycol (meth)acrylate units represented by the following formula:
1% by weight, and 0 to 40% by weight of one or more other ethylenically unsaturated monomer units, and has a contact angle with water of 80° or less in a film state. The knitted fabric for cleaning according to item 2. ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (In the formula, R_1 and R_2 are each hydrogen or methyl group, and n is a number from 2 to 9.)