JP2799510B2 - Water repellent fiber - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a water-repellent fiber having excellent workability, which is useful mainly as a surface material for disposable diapers and sanitary napkins.

[Conventional technology]

The central part of the surface material of the disposable diaper or the sanitary napkin is required to have a water permeability for rapidly transmitting the liquid to be absorbed to the absorbent material. On the other hand, both ends are desirably water-repellent to prevent lateral leakage of the liquid to be absorbed or the liquid once absorbed. Originally, polyolefin-based fibers and polyester-based fibers are hydrophobic and hardly wet with water, and are therefore suitable for use at both ends.

However, since it is hydrophobic, it is extremely easily charged, and it is easy to cause an accident such as winding around a cylinder or a guide roller of a card machine, and the workability is poor. For the purpose of improving processability, it is common practice to attach an antistatic agent. However, a fiber with an ordinary antistatic agent loses its original hydrophobicity, becomes hydrophilic, and loses water repellency.

[Problems to be solved by the invention]

As described above, it is a difficult task to simultaneously satisfy both the hydrophobic property, that is, the water repellency, and the processability.

[Means for solving the problem]

The present inventor has conducted intensive studies to improve the above-mentioned drawbacks. As a result, the mixing ratio (weight ratio) of the silicone emulsion polymer (A) and the cetyl phosphate K salt (B) was added to the surface of the polyolefin or polyester fiber. But (A): (B)
= 55 to 70: 45 to 30: 0.1 to 1.5% by weight of the mixture to achieve the intended purpose, the present invention has been completed.

In the present invention, the fiber composed of polyolefin or polyester is polyethylene fiber, polypropylene fiber,
Polyolefin fibers such as polypropylene-polyethylene composite fibers, polypropylene-ethylene-vinyl acetate copolymer composite fibers, polyester fibers such as polyethylene terephthalate fibers, polyethylene terephthalate / polyethylene terephthalate isophthalate copolymer composite fibers,
Further, it refers to polyester / polyolefin fibers such as polyester / polyethylene composite fibers.

The silicone emulsion polymer (A) is obtained by emulsion polymerization of dimethyl silicone using an anionic emulsifier such as sodium salt of alkylbenzenesulfonic acid, and has a molecular weight of 8
It is preferably used in the range of from 0,000 to 1,200,000.

The cetyl phosphate K salt (B) usually contains various mono, di, and poly cetyl phosphate K salts. In the present invention, the compounding ratio of the mono, di, and poly is 30 to 40:50 to 6,
A range of 0: 5 to 15 is preferably used.

Silicone emulsion polymer (A) and cetyl phosphate K
The mixing ratio (weight ratio) of the salt (B) is (A) 55 to 70%,
(B) is within the range of 30 to 45% and is 100% in total. If (A) is less than 55%, the water repellency becomes insufficient, and
If it exceeds 70%, the antistatic property deteriorates, and problems occur in the card process and the like. If (B) is less than 30%, the antistatic property will deteriorate, and 45%
If more, the water repellency becomes insufficient. That is, (A) is a water repellency improving component and (B) is an antistatic component. The amount of the mixture of (A) and (B) attached to the fiber is 0.1 to 1.5% by weight, preferably 0.2 to 0.8% by weight. 0.1% adhesion amount
If it is less than 1.5%, the antistatic property is poor. If it exceeds 1.5%, problems such as easy cutting of the web in the carding process and contamination of the processing machine by excess oil agent occur.

There is no particular limitation on the method of attaching these oil agents to the fibers, and a known method such as attaching by oiling rolls in the spinning process, or applying a spray method or immersion method after processing the web into a nonwoven fabric is used. it can.

〔The invention's effect〕

The water-repellent fiber of the present invention is excellent in processability and water repellency, and when this is processed and used at both ends of a paper diaper or the like,
A good product that can prevent side leakage is obtained.

As a method for processing the water-repellent fiber of the present invention into the above surface material, a known nonwoven fabric manufacturing method such as forming a web having a desired basis weight using a card machine and forming the nonwoven fabric by a needle punch method or a hot roll method can be used. It is.

〔Example〕

The present invention will be described with reference to Examples and Comparative Examples. The following physical property evaluation methods were used in each case.

Water repellency: A nonwoven fabric (A4 size) having a basis weight of about 20 g / m ² is obtained from a web obtained by stapleting a sample short fiber through a card. This nonwoven fabric is layered on paper (Toyo Filter Paper No. 50), and as shown in FIG.
Place on the slope of ゜ and prepare another absorbent paper whose weight has been measured in advance under the slope. Next, artificial urine was allowed to flow down from the height of 1 inch on the nonwoven fabric for 25 seconds in 3 seconds, the weight of the artificial urine absorbed by the absorbent paper below the slope was measured, and the water repellency (%) was evaluated by the following calculation. The closer to 100%, the better the water repellency.

Artificial urine composition (in _{1kg) Urea 20,0g NaCl 8,0g MgSO 4} · 7H 2 O 0,8g CaCl 2 · 2H 2 O 0,3g pure water 970,9g antistatic: Sample short fibers 20 ° C., relative The web was formed using a card tester under the condition of a humidity of 65%, and the voltage of static electricity generated on the web was measured. If it is less than 100 V, it can be put to practical use.

Examples 1 to 3 and Comparative Examples 4 to 8 Various compositions shown in Table 1 were drawn by an oiling roll in a stretching step into a sheath-core composite fiber (composite ratio 50/50) using polypropylene as a core component and polyethylene as a sheath component. The oil agent was applied and cut to obtain a staple having a single yarn fineness of 2 denier and a fiber length of 51 mm. Each of these staples was made into a card web and heat-treated with a suction dryer (140 ° C.) to give a nonwoven fabric with a basis weight of about 20 g / m ₂ . Table 1 also shows the electrostatic voltage and the water repellency of the nonwoven fabric measured in the carding process for each sample.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram of an apparatus for measuring the water repellency of a nonwoven fabric. In the figure, 1 is an artificial urine storage, 2 is a nonwoven fabric, 3 is paper, 4 is absorption paper, and 5 is an artificial urine dropping nozzle.

Claims (1)

(57) [Claims] The mixing ratio of the silicone emulsion polymer (A) to the cetyl phosphate K salt (B) is (A) :( B) = 55 to
70: A fiber consisting of polyolefin or polyester having a mixture of 45 to 30 deposited on the fiber surface at 0.1 to 1.5%.