JP5313488B2 - Wet wiper base sheet and wet wiper - Google Patents

Description

  The present invention relates to a wet wiper base sheet and a wet wiper. In particular, the present invention relates to a wet wiper base sheet not containing rayon fibers and a wet wiper using the same.

A wet wiper for wiping with a chemical solution such as water or alcohol is well known. Among these wet wipers, softness is especially important for those used for wiping the human body, such as wipes and butt wipes.
For this reason, spunlace nonwoven fabrics containing rayon fibers that are excellent in softness and hydrophilicity have been mainly used as wet wipers for personal use.
Further, as a material specializing in hand-wiping applications, a base material sheet obtained by creping after a layer made of cellulose fiber and a layer made of cellulose fiber and synthetic fiber are laminated is also known.
JP 2004-190163 A JP 10-331098 A

However, a spunlace nonwoven fabric containing rayon fibers has a low surface strength, and is likely to fluff and fluff during wiping operations.
In addition, so-called back-through, in which the wiped dirt comes off on the opposite surface, is likely to occur.
Further, although wet wipes, which are disposable articles, place importance on costs, rayon fibers are expensive, which hinders cost reduction.
On the other hand, when the layers made of cellulose fibers and the layers made of cellulose fibers and synthetic fibers are laminated together, the surface strength of the layers made only of cellulose fibers is weak, and the so-called back-through where the wiped dirt comes off on the opposite side Is likely to occur.
Therefore, the object of the present invention is to secure a sufficient hydrophilicity and softness without using rayon fibers, and further, a base sheet for wet wipers that does not generate fuzz and fluff on the surface accompanying a wiping operation, and An object of the present invention is to provide a wet wiper using the base sheet for the wet wiper.

The present invention that has solved the above problems has a basis weight in the range of 35 to 70 g / m ² , a paper thickness in the range of 300 to 1,000 μm, does not include rayon fibers,
It is composed of pulp fibers containing 50-100% of softwood bleached kraft pulp, and PET / PE core-sheath heat-bonding binder fibers having a fusing temperature of 100-160 ° C., and the pulp fibers and the heat-bonding binder fibers. The weight ratio is 7.5: 2.5 to 6.0: 4.0, and the synthetic fiber mixed paper layer in which the pulp fiber and the heat-fusing binder fiber are fused is used as the front and back layers.
The intermediate layer between the front and back layers is a paper layer consisting only of pulp,
And the front and back layers and the paper layer are fused by the heat fusion binder fiber,
It is the base sheet for wet wipers characterized by this.
The wet wiper base material preferably has a softness of 60 g or less measured by a handle ohm method of JIS L 1096E, measured in a state in which water is impregnated with 250% by weight of its own weight.
Further, it is desirable that the result of the surface wear test using the Gakushin friction tester in a state containing 250% by weight of water is 7 times or more.
Further, the wet wiper base sheet further has ceiling portion area 0.1～40Mm ^2, you're a good one which is working depth of 0.1mm or more heat the steel embossing.
The base sheet for wet wiper is preferably impregnated with a chemical solution to form a wet wiper.

  According to the present invention as described above, a base sheet for wet wipers that ensures sufficient hydrophilicity and softness without using rayon fibers, and also has no surface fuzz and fluff generation associated with the wiping operation, and A wet wiper is provided.

Next, the best mode for carrying out the present invention will be described in detail below.
The substrate sheet for wet wipers of the present invention (hereinafter also simply referred to as a substrate sheet) has a basis weight of 35 to 80 g / m ² , preferably 40 to 70 g / m ² , and a paper thickness of 300 to 1,000 μm. It is in range.
The rice tsubo is measured based on JIS P 8124. When the surface area is less than 35 g / m ² , it becomes unpleasant when the dirt is wiped thin, and when it exceeds 70 g / m ² , the paper becomes hard and difficult to use on the wiping surface. The paper thickness is 300 to 1,000 μm, preferably 500 to 900 μm. When the paper thickness is less than 300 μm, the dirt is easily removed from the back, and when it exceeds 1,000 μm, the paper becomes thick and difficult to use on the wiping surface.
And, the base sheet of the present invention characteristically has a plurality of layer structures, and the front and back layers thereof are a synthetic fiber mixed paper layer containing pulp and heat-bonding binder fibers, and not containing rayon fibers,
The intermediate layer interposed between these front and back layers is a paper layer in which at least one layer of fibers consists only of pulp. A preferred example of this embodiment is a single intermediate layer, but two or more intermediate layers may be used. Of course, there may be a synthetic fiber mixed paper layer in the intermediate layer.
This base sheet is a papermaking raw material for constituting each layer, for example, through a known papermaking process, specifically, a wire part, a press part, a dryer part, a creping part, a size press, a calendar part, etc. Then, the paper is made into a wet or dry sheet form, and in this state, the layers may be appropriately laminated to integrate the layers.
When making paper, for example, a suitable agent such as a pH adjuster such as a dispersant, caustic soda, or aqueous ammonia, an antifoaming agent, an antiseptic, a fluorescent dye, a mold release agent, a water-resistant agent, a flow modifier, and a yield improver. Can be added.

On the other hand, examples of the pulp that can be used for the synthetic fiber mixed paper layer include wood pulp, non-wood pulp, synthetic pulp, and waste paper pulp. More specifically, ground wood pulp (GP), stone ground pulp (SGP), refiner ground pulp (RGP), pressurized ground wood pulp (PGW), thermomechanical pulp (TMP), chemithermomechanical pulp (CTMP), bleach Crafts such as mechanical pulp (MP) such as dochem thermomechanical pulp (BCTMP), chemical mechanical pulp (CGP), semi-chemical pulp (SCP), hardwood bleached kraft pulp (LBKP), softwood bleached kraft pulp (NBKP) Synthetic pulp made from chemical pulp (CP) such as pulp (KP), soda pulp (AP), sulfite pulp (SP), dissolving pulp (DP), nylon, rayon, polyester, polyvinyl alcohol (PVA), etc. , Waste pulp (TP), cotton, flax, hemp, jute, mani One or several types of rag pulp, straw pulp, esparto pulp, bagasse pulp, bamboo pulp, kenaf pulp and other auxiliary pulps such as bast pulp, etc. can do.
Preferably, the pulp is virgin pulp. Further, it is preferable that 50 to 100% of softwood bleached kraft pulp (NBKP) is contained, and particularly 100% of softwood bleached kraft pulp is preferable. Since softwood bleached kraft pulp is long and thick fiber, it is desirable because it becomes a strong paper.

  On the other hand, examples of the heat-bonding binder fiber that can be used in the synthetic fiber mixed paper layer include, for example, polypropylene resins, polyethylene, polyolefin resins such as crystalline propylene copolymer composed of propylene and α-olefin; polyamide resins; polyethylene terephthalate, polybutylene Select one or several types of terephthalate, diol and terephthalic acid / isophthalic acid copolymerized low melting point polyester, polyester resin such as polyester elastomer, or thermoplastic fiber composed of thermoplastic resin such as fluororesin. Can be used.

  The heat-fusible binder fiber may be a single component fiber, but is a composite fiber constituted by appropriately combining a plurality of resins, for example, a parallel type, a sheath core type, an eccentric sheath core type, a multilayer type of three or more layers, and a hollow A composite fiber having a structure in which at least a part of the fiber surface is formed by a low melting point resin, such as a parallel type, an inner sheath core type, a deformed sheath core type, and a sea-island type, can also be used.

Particularly suitable as the heat-sealable binder fiber is one containing a heat-sealable binder fiber having a PET (polyethylene terephthalate) / PE (polyethylene) core-sheath structure. In particular, it is preferable to include 100% of this.
The fiber length of the heat-fusible binder fiber is not limited, but the fiber length is preferably 3 mm or more and 100 mm or less. More preferably, it is 3 mm or more and 10 mm or less. If it is 3 mm or less, the yield tends to be lowered during sheet formation, and the production problem that the blending ratio of the heat-bonding fibers may change is likely to occur. Therefore, it is difficult to manufacture and the cost is increased. On the other hand, even if it is 10 mm or more, the screen of the paper machine tends to be clogged, and the possibility that the synthetic fiber will be poorly dispersed and hardened into a flock shape is increased.
In addition, when the fusing temperature of the heat fusing binder fiber is 100 to 160 ° C., the fusing fiber is melted to the extent that it does not stick to the drier with the dryer of the paper machine, and the strength of the synthetic fiber mixed paper making layer is improved. further heat calendering treatment, heat steel matched embossing lines UTO, strength in a state where damp is improved.
The fiber thickness of the fiber used is 0.2 to 6.0 dtex, preferably 1.0 to 3.0 dtex. If the thickness of the fiber is less than 0.2 dtex, the tensile strength at the time of drying and wetting is insufficient. On the other hand, if it exceeds 6.0 dtex, the rigidity becomes high and the softness becomes inferior.

  On the other hand, the synthetic fiber papermaking layer of the present invention is characterized in that the weight ratio of pulp to heat-bonding binder fiber is 7.5: 2.5 to 6.0: 4.0. When the pulp ratio exceeds 7.5 and the heat-bonding binder fiber ratio is less than 2.5, the surface strength in a wet state becomes weak. On the other hand, when the pulp ratio is less than 6.0 and the heat-fusing binder fiber ratio exceeds 4.0, the rigidity becomes high and the softness becomes inferior.

On the other hand, the intermediate layer is made of 100% pulp. Examples of the pulp include wood pulp, non-wood pulp, synthetic pulp, and waste paper pulp. More specifically, ground wood pulp (GP), stone ground pulp (SGP), refiner ground pulp (RGP), pressurized ground wood pulp (PGW), thermomechanical pulp (TMP), chemithermomechanical pulp (CTMP), bleach Crafts such as mechanical pulp (MP) such as dochem thermomechanical pulp (BCTMP), chemical mechanical pulp (CGP), semi-chemical pulp (SCP), hardwood bleached kraft pulp (LBKP), softwood bleached kraft pulp (NBKP) Synthetic pulp made from chemical pulp (CP) such as pulp (KP), soda pulp (AP), sulfite pulp (SP), dissolving pulp (DP), nylon, rayon, polyester, polyvinyl alcohol (PVA), etc. , Waste pulp (TP), cotton, flax, hemp, jute, mani One or several types of rag pulp, straw pulp, esparto pulp, bagasse pulp, bamboo pulp, kenaf pulp and other auxiliary pulps such as bast pulp, etc. can do.
Preferably, the pulp is virgin pulp. Further, the softwood bleached kraft pulp (NBKP) is contained 50-100% C., in particular may be between softwood bleached kraft pulp with 100%.

On the other hand, the base material sheet of the present invention is preferably heat calendered in a temperature range in which the heat-bonding binder fiber melts, and further heat steel match embossed.
The heat steel match embossing is performed by embossing the sheet through a sheet between a pair of heated metal rolls that are configured so that the embossing convex part of one metal roll fits into the embossing concave part of the other roll. It is a method of granting.
Accordingly, the convex embossing on the sheet surface becomes a concave embossing on the back surface of the sheet and the heat-bonding binder fiber is fused.
As an advantage of heat steel match embossing after heat calendering, the heat calendering binder fibers are melted by heat calendering, and the bonds between the fibers in the synthetic fiber mixed paper layer are strengthened and the surface is smooth. Is done. That is, surface strength and smoothness are exhibited. At the same time, between the synthetic fiber-mixed paper layer and the pulp layer, the adhesion of each layer becomes strong in the thermal calendering process, and the possibility of delamination is remarkably reduced.
And by embossing, while a softness is maintained, a base material sheet expresses thickness, a hand feeling and a chemical | medical solution retainability improve, and the wiping performance also improves by the unevenness | corrugation of the surface by embossing. In particular, in the synthetic fiber mixed paper in the present invention, by including the heat-bonding binder fiber, the unevenness of the applied emboss is elastic due to the melt deformation of the heat-bonding binder fiber, and it is extremely difficult to be crushed even by wiping operation. .

Furthermore, since heat steel match embossing is performed after the heat calendering process, the heat-bonding binder fiber is melted in advance during the calendering process, so there is no accident that the sheet adheres to the metal roll during embossing, The manufacturing advantage that the speed of heat steel match embossing can be increased to 100 to 200 m / min is also obtained.
The specific shape of one emboss is an appropriate design item. For example, many squares or ellipses can be illustrated. In addition, it is preferable that the top of the emboss is flat since the adhesion of each layer is ensured. Area of the top portion, 0.1~40mm ^2, more preferably 0.25~4.0mm ^2, particularly preferably 0.5 to 2.0 mm ^2. It becomes impossible to obtain sufficient adhesive strength between sheets, where the top area is too narrow. On the other hand, if the area of the top is too large, the volume of the absorption space due to embossing becomes small, so that sufficient absorption capacity cannot be obtained.

The depth of embossing is also an appropriate design matter, but it is generally about 0.1 mm or more, preferably 0.5 mm or more, and more preferably 1.3 mm or more and 2.5 mm or less.
An emboss pattern formed by a large number of unit embosses is also an appropriate design matter, and conventionally known emboss patterns can be appropriately adopted in consideration of aesthetics and functionality.
When the base sheet of the present invention is a wet wiper, especially the front and back surfaces exhibit excellent liquid permeability and less fluffing of the synthetic fiber paper, and the intermediate layer has excellent chemical liquid retention. Softness when wet is expressed, and these advantages are combined. In particular, even if rayon fiber is not used, it is extremely soft and excellent in liquid retention. In addition, since no rayon fiber is used, the raw material cost can be reduced, and since it can be manufactured by a paper machine, the manufacturing cost can be reduced.

On the other hand, it is desirable that the wet base sheet has a softness of 60 g or less as measured by a handle ohm method of JIS L 1096E, which is measured in a state where water is impregnated with 250 wt% of its own weight. If it is 60 g or more, it becomes hard and difficult to wipe off.
Further, the wet substrate sheet should have a surface abrasion test result of 7 times or more, preferably 7 to 11 times in a state of containing 250% by weight of water by a Gakushin friction tester.
Specifically, this surface wear test uses a Gakushin type friction fastness tester (for example, Tester Sangyo Co., Ltd., AB 301 COLOR FASTNESS RUBBING TESTER). A measurement sample impregnated with 250 wt% of its own weight (width 25 mm, length 80 mm) is attached to the moving friction element side, and the measurement sample is reciprocated under a load of 200 g to slide on artificial leather. The reciprocating movement is performed with a stroke of 120 mm at a speed of 30 times / minute, and one reciprocation is counted as one time. And the frequency | count when it can confirm visually that the pill was generated on the surface is measured, and it is set as a result.
The reason why the moisture is impregnated with 250% by weight of the own weight is that the moisture content of a general personal wet paper is about this level, and the load is 200 g when the skin is wiped off. This is because the load applied to is approximately this level. In addition, the measurement sample is fixed on the moving friction element side and the artificial leather is fixed on the fixed surface side because the normal wiping operation wipes the skin so as to slide on the skin with a wiper. Furthermore, the reason why the quality is judged at the boundary of 7 times is that when the dirt on the skin is wiped off, it is often moved back and forth about 7 times.

On the other hand, when the base sheet of the present invention described above in detail is used as a wet wiper, a known chemical solution may be appropriately impregnated. This chemical solution is not limited in the present invention. Known chemicals can be used. For example, a known chemical solution containing an alcohol such as methanol, ethanol or glycerin, a cooling agent such as water or menthol, a fragrance or the like in an appropriate blending ratio can be used.
This wet wiper of the present invention expresses the excellent liquid permeability and fluffiness of the synthetic fiber paper especially on the front and back surfaces, and exhibits excellent chemical retention and softness when wet in the intermediate layer. These advantages are combined, and in particular, even without the use of rayon fiber, it is extremely soft and excellent in liquid retention. In addition, since no rayon fiber is used, the raw material cost can be reduced, and since it can be manufactured by a paper machine, the manufacturing cost can be reduced.

Next, since the softness and abrasion resistance in the wet state were tested and evaluated for Examples, Comparative Examples and Conventional Examples of the present invention, the results are shown in Table 1 together with the physical properties of each example. The heat-sealable binder core-sheath fiber used was a PET / PE core-sheath fiber having a thickness of 2.2 dtex, a fiber length of 5 mm, and a melting point of 110 ° C. (Teijin Fibers Ltd. core-sheath composite type TJ04CN). A crimped fiber having a thickness of 2.2 dtex and a fiber length of 5 mm was used, and an acrylic fiber having a thickness of 0.6 dtex and a fiber length of 10 mm was used.
In the table, 250% impregnation means that the sample was measured in a state where water was impregnated with 250% by weight of its own weight.

Moreover, about the Example and the comparative example, after heat-sheathing the sheet | seat which laminated | stacked all, the heat steel match embossing was performed.
The dry tensile strength and the wet tensile strength were measured based on JIS P 8113, the US basis weight was measured based on JIS P 8124, and the paper thickness was measured by a microgauge method. Further, the density was calculated from the rice tsubo and the paper thickness.
The dryness and softness at the time were measured according to the handle ohm method of JIS L 1096E. The softness at the time of drying was measured by changing the JIS-specified gap 5 mm to 20 mm, and the softness at the time of 250% impregnation was measured at the JIS-specified gap 5 mm.
As the artificial leather in the surface abrasion test, “Saplare” (model number: PBZ13001, color: black) manufactured by Idemitsu Techno Fine Co., Ltd. was used.

  As shown in Table 1, the examples of the present invention showed better results in wear resistance and softness when impregnated with water than the comparative examples. Also, wet and dry tensile strength is sufficient for use. From this, the base sheet for wet wipers of the present invention does not use expensive rayon fibers, that is, is inexpensive, has sufficient hydrophilicity and softness, and has surface fuzz due to wiping operation. It is recognized that the base sheet for wet wipers has no generation of pills.

  The present invention can be used for a substrate sheet for wet wipers.

Claims (5)

US basis weight is in the range of 35 to 70 g / m ² , paper thickness is in the range of 300 to 1,000 μm, no rayon fiber is included,
It is composed of pulp fibers containing 50-100% of softwood bleached kraft pulp, and PET / PE core-sheath heat-bonding binder fibers having a fusing temperature of 100-160 ° C., and the pulp fibers and the heat-bonding binder fibers. The weight ratio is 7.5: 2.5 to 6.0: 4.0, and the synthetic fiber mixed paper layer in which the pulp fiber and the heat-fusing binder fiber are fused is used as the front and back layers.
The intermediate layer between the front and back layers is a paper layer consisting only of pulp,
And the front and back layers and the paper layer are fused by the heat fusion binder fiber,
A substrate sheet for wet wipers characterized by the above. The base sheet for wet wipers according to claim 1, which is heat steel match embossed with a top area of 0.1 to 40 mm ² and a depth of 0.1 mm or more . The base sheet for wet wipers according to claim 2, wherein the softness according to the handle ohm method of JIS L 1096E measured in a state impregnated with 250% by weight of water is 60 g or less. The substrate sheet for wet wipers according to claim 2 or 3 , wherein the result of a surface abrasion test using a Gakushin friction tester in a state containing 250% by weight of water is 7 times or more.   A wet wiper, wherein the wet wiper base sheet according to any one of claims 1 to 4 is impregnated with a chemical solution.