JP2005144288A - Swab - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a swab which is used mainly for wiping an electronic component or an optical component and is a wiping tool obtained by fitting a wiping part to the tip of a bar-shaped material, by which non-wiped portions are not left on the object to be wiped and which does not damage the object to be wiped, does not generate dust by itself and does not elute a solvent. <P>SOLUTION: A polyolefin sponge is used in the wiping part of the wiping tool (swab). It is further preferable that the polyolefin sponge is provided with specific ranges in porosity, pore diameter, and chlorine content. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

The present invention relates to a swab mainly used for wiping electronic components and optical components, that is, a wiping tool in which a wiping portion is attached to the tip of a rod-like object.

In the manufacture of electronic parts, optical parts, etc., it is necessary to wipe not only wide flat parts but also narrow local spaces such as narrow specific parts, corner parts, grooves, etc., and wiping tools collectively called various swabs are used. Has been.

  The most typical swab is a cotton swab, but the fibers used in the cotton ball are thick, the wiping performance is insufficient, the object to be wiped is easily damaged, and self-dusting due to fiber scraps falling off. There is elution of molding alcohols such as polyvinyl alcohol and vinyl acetate, and it has excellent wiping ability that can be wiped without damaging the target without damaging the target, and it is non-contaminating that does not pollute the target with its own dust and eluate. It was unsuitable for highly demanding advanced wiping.

  In addition to cotton swabs, swabs using polyester knit cloth, polyurethane sponge, ultrafine filament cloth of 0.5 denier or less instead of cotton ball parts are also used. It was.

  Polyester knitted fabrics are thick fibers like cotton swabs, are inferior in wiping properties, and have high self-dusting properties. Polyurethane sponges have little wiping residue and are less likely to damage the object, but often dissolve or swell in the solvent used together during wiping and contaminate the object with the polyurethane component that dissolves in the solvent. The ultrafine filament cloth has fine fibers and is difficult to damage an object, but is self-dusting because it is a cloth.

The present invention provides a swab that has not been wiped off, does not damage an object, is not self-dusting, and has no solvent eluate, which cannot be achieved by the prior art.

That is, the present invention relates to a swab having a length of 2 to 30 cm and a swab whose tip is a wiping portion. The wiping portion is made of a polyolefin sponge, and the fixing means to the rod-like material has a hole in the center of the sponge. It may be a physical fixing method in which a rod-like object is inserted into the opening, or any method such as a fixing method using an adhesive, heat fusion, or the like.

  Next, the present invention will be described in detail.

  The polyolefin referred to in the present invention means an olefin homopolymer such as polyethylene, polypropylene and polystyrene, and a polymer elastomer composed of various monomers such as polyethylene vinyl acetate, saponified product, ethylene, propylene, styrene and butadiene, and a mixture thereof. It may be.

  For making sponge (foaming) of polyolefin, foaming agent such as trichlorofluorinated methane, tetrachlorodifluorinated ethane, azodicarbanamide, para-toluenesulfonylhydrazine is kneaded into the polyolefin, and then extruded, injected, and compressed. After molding, it may be heated and foamed (dry foaming method), but polyolefins such as alginic acid, carboxymethylcellulose, polyvinyl alcohol, sodium polyacrylate, various starch organics and / or sodium, potassium, magnesium, calcium, strontium, aluminum, etc. This is a method (wet foaming method) in which a water-soluble substance such as an inorganic salt such as chloride or sulfate is kneaded, extruded, molded by injection and compression, and then the water-soluble substance is eluted in water to obtain a sponge. Also good.

In order to wipe off the dirt to be wiped or the dirt diluted with the combined solvent without wiping, it is necessary to quickly suck the dirt before it is spread with the polyolefin sponge as the wiping portion. Further, cushioning properties are necessary to prevent the object from being damaged, and the polyolefin sponge must be a continuous pore body having a small pore diameter and a high porosity. Specifically, the pore diameter must be 150 μm or less and the porosity must be 50% or more.
In the dry foaming method, it is difficult to obtain a continuous pore body having such a fine pore diameter and a high porosity with good reproducibility, so the wet foaming method is preferable.

Examples of solvents used in wiping include methyl alcohol, ethyl alcohol, isopropyl alcohol, acetone, methyl ethyl ketone, cyclohexane, ethyl acetate, dichloromethane, trichloroethane, etc. Since there is nothing, the combined solvent does not elute and does not contaminate the object. On the other hand, polyurethane sponge dissolves or swells in these solvents.
Polyolefin sponges, whether dry foaming or wet foaming, are monolithic and are not knitted or bonded, so they are not self-dusting.

  As electronic parts and optical parts become smaller and more integrated, the defect rate at the initial inspection increases, and even if the initial inspection passes, the proportion of defects due to long-term use also increases. Contamination with anions such as chloride ion, nitrite ion, nitrate ion, phosphate ion and sulfate ion is one of the causes that hinder the reduction of the defect rate and the improvement of reliability during long-term use. In particular, chloride ions are a problem. In such a case, residual chlorine ions can be reduced or eliminated by washing the polyolefin sponge with pure water.

  As a means of fixing the polyolefin sponge to the rod-like material, an adhesive or a method of fixing by heat fusion may be considered, but if the adhesive is fixed with an adhesive, the adhesive may elute into the combined solvent and contaminate the object. If fixed by heat fusion, the heat-sealed part becomes hard and the object may be damaged. The most preferable fixing method is a method in which a hole is formed in the central portion of the polyolefin sponge, and a rod-like object having a diameter larger than the hole diameter is inserted and fixed therein. According to this fixing method, if the polyolefin sponge is soiled by wiping, the rod-shaped material can be repeatedly used any number of times by removing the soiled polyolefin sponge from the rod-shaped material and replacing it with a new polyolefin sponge.

  Opening a hole in the center of the polyolefin sponge can be easily performed by forming a hole when forming a polyolefin kneaded product and then forming a sponge.

  This will be described in accordance with the following examples.

After a polyolefin copolymer (mixture of 80 parts by weight of Miraplane S8831 manufactured by Mitsubishi Chemical MKV Co., Ltd. and 20 parts by weight of Mitsui High Wax NL100 manufactured by Mitsui Chemicals Co., Ltd.) is melted with two rolls at 160 ° C, Lower the temperature to 120 ° C, add dextrin (150 parts by weight), knead, and from a single screw extruder with a screw diameter of 40 mmφ and L / D27 with a die consisting of a 5 mm outer diameter die and 1 mm inner diameter mandrel. An extruded tube was obtained. The tube was cut into a length of 15 mm and immersed in hot water at 80 ° C. to elute dextrin and dried. A 2 mm-diameter polypropylene shaft with a tip cut into a conical shape was inserted into a hole in the center of the obtained polyolefin sponge to obtain an A swab.

After elution of dextrin in water, an experiment was carried out in the same manner as in Example 1 except that dipping was repeated three times in pure water (ion-exchanged water) of 10 times the apparent volume ratio to obtain B swab.

Comparative example

As a swab using a polyurethane sponge as a wiping part, Harvest Co., Ltd.'s trade name Rubistick T-10 was selected as a comparative sample (C swab). Swabs with a cotton ball, polyester knit cloth, or ultrafine filament cloth as the wiping part have self-dusting properties and were not compared. The following table shows the results of a comparison of the porosity, pore diameter, solvent elution amount, residual chlorine ions, suction speed, and surface scratch resistance of each swab.

Measuring method:
The apparent specific gravity (ρ) of the porosity wiping portion and the true specific gravity (d) of polyolefin or polyurethane are measured.
Porosity (%): (d-ρ) / d X 100
Take a scanning electron micrograph (100x magnification) of the pore size wiper. Draw two lines of length (l) diagonally and count the number of pores (n) across each line.
Pore diameter (μm): 2l / n
Solvent elution volume
67 wiping parts are immersed in methyl alcohol (300 ml) at room temperature for 2 hours. The supernatant (250 ml) of methyl alcohol is separated and concentrated, and further evaporated to dryness at 105 ° C. for 3 hours and weighed.
Solvent elution amount (mg / piece): Evaporated dry weight is converted to one wiping part.
Residual chloride ion
Add ion-exchanged water (100 ml) to the 6 wiping sections and leave it in a 95 ° C water bath for 3 minutes. Take it out from the water bath and let it cool to room temperature, then measure the chlorine ion with an ion chromatograph.
Residual chlorine ion (μg / piece): Chlorine ion measurement value is converted to one per wiping section.
Absorbing speed Immediately immerse the end of the wiping part (the surface cut to 15 mm long) in isopropyl alcohol parallel to the liquid surface, and video-shoot the isopropyl alcohol sucking surface.
Suction speed (mm): Suction surface height after 5 seconds of immersion.
Surface scratchability A compact disc is wiped twice with a load of 10 g / cm ² , and the wiped surface is judged with the naked eye and a scanning electron microscope.

Claims (4)

A swab having a length of 2 to 30 cm and a swab whose end is a wiping portion, wherein the wiping portion is made of a polyolefin sponge. 2. The swab according to claim 1, wherein the polyolefin sponge is a continuous pore body having a porosity of 50% or more and a pore diameter of 150 μm or less. The swab according to claim 1 or 2, wherein the chlorine ion content per polyolefin sponge is 0.25 µg or less. Water-soluble substance is kneaded into polyolefin, the kneaded product is extruded, injection or compression molded, water-soluble substance is eluted by immersing the molded product in water, and further containing chlorine ions by immersing in pure water The swab of claims 1, 2 and 3 wherein the amount is reduced.