JP4855241B2 - Absorbent / release sheet and method for producing the same - Google Patents

Description

  The present invention mainly contains moisture, and further, for example, moisture containing humectants, deodorants, refreshing agents, fragrances, anti-inflammatory agents, moisturizers, skin nutritional supplements, antiseptics, antibacterial agents, plant-derived essential oils, and the like. It has a function of absorbing and absorbing water and a function of gradually releasing and releasing them (hereinafter also referred to as “desorption and release characteristics”), food drip sheet, wet wiper, hygiene absorber, moisture retention sheet, face mask The present invention relates to a nonwoven fabric-type desorbing / releasing sheet useful for wet masks, cosmetic sheets, and the like.

Conventionally, sheet-like structures mainly composed of water-absorbing substances are, for example, (1) drip sheets and hygiene absorbers that absorb moisture and blood generated from food and the body, (2) floors, furniture, kitchens, humans There are known uses such as wet wipers that clean the hands, feet, face, etc., and (3) moisturizing sheets, face masks, wet masks, cosmetic sheets, etc. that are particularly worn on the face.
For these sheet-like structures, woven or knitted fabrics, nonwoven fabrics, fiber structures, or the like to which various hydrophilic agents, water-absorbing agents, hydrophilic fibers, or the like are added or contained as carriers for moisture or drugs are used. Examples of these sheet-like structures include the following prior art.

  Patent Document 1 [JP 2000-229850 A (sustained release structure containing a drug and having water absorption and water retention functions)] includes, for example, synthetic fiber nonwoven fabric, water absorbent paper, water absorbent swellable polymer (high water absorption property). Polymer “SAP”) and cellulose pulp mixture layer, and water absorbent paper in this order, laminated with embossing rollers, water is absorbed into the resulting sheet, and then applied to the face for cooling. A structure that maintains a refreshing feeling for a long time is presented. However, water-absorbent paper made of pulp has poor water resistance, and thus has a problem in handleability after moisture application. Moreover, there is no description or suggestion about the layer, sheet, and nonwoven fabric formed by the composite of synthetic fiber and pulp as in the present invention. The water-absorbing swellable polymer is described as a powder, and there is no description or suggestion about the superabsorbent fiber (SAF) of the present invention.

  Patent Document 2 [Japanese Patent Application Laid-Open No. 2004-43442 (moisturizing sheet agent)] includes a non-volatile and water-affinity solvent such as glycerin and polyhydric alcohol, and a water-absorbing composition such as hydroxypropyl cellulose. However, the water-absorbing composition is liquid or powder, and the fibrous form is not described or suggested. Moreover, although the non-woven fabric is illustrated as a support body in the said patent document, there is no specific limitation in a mixing rate etc. only by mentioning the fiber known for general purpose.

  Furthermore, Patent Document 3 [Japanese Patent Laid-Open No. Sho 61-68042 (aroma imparting agent for sanitary goods)] describes a water-insoluble polymer powder having a high degree of water swelling and water content as an aroma imparting agent for sanitary goods, That is, it is disclosed that a super absorbent polymer powder containing a fragrance is interposed between a pair of non-woven sheets and applied to sanitary products such as sanitary napkins and baby napkins. Also in this example, no superabsorbent fiber (SAF) is disclosed or suggested. In the case of powder, since the surface area is smaller than that of the fiber, it has a drawback that performances such as water absorption, moisture absorption, and release are not sufficiently exhibited.

  Furthermore, Patent Document 4 [Japanese Patent Laid-Open No. 6-158500 (Freshness Preserving Sheet) discloses a nonwoven fabric excellent in water absorption and hygroscopicity composed of highly water-absorbing fibers and heat-sealing fibers, and water such as fruits and vegetables. A freshness-preserving sheet for preventing burns is shown. However, the function of sustained release intended by the present invention is not mentioned at all, and there is no description of hydrophilic fibers other than SAF.

JP 2000-229850 A JP 2004-43442 A JP-A-61-68042 JP-A-6-158500

  The present invention has a function of absorbing and absorbing moisture, including moisturizers, deodorants, refreshing agents, fragrances, flame retardants, moisturizers, skin nutrition supplements, antiseptics, antibacterial agents, plant-derived essential oils, and the like. An object of the present invention is to provide a nonwoven fabric-like desorbing / releasing sheet having a function of gradually releasing and releasing them.

In the present invention, (A) synthetic fiber (excluding hydrophilic fibers and superabsorbent fibers described later; the same applies hereinafter) / hydrophilic fiber = 100 to 20/0 to 80% by weight (however, synthetic fiber + hydrophilic fiber) = 100% by weight) surface layer,
(B) Synthetic fiber / hydrophilic fiber / superabsorbent fiber = 10-90 / 5-80 / 5-80% by weight (however, synthetic fiber + hydrophilic fiber + superabsorbent fiber = 100% by weight) And (C) a synthetic fiber / hydrophilic fiber = 100 to 60/0 to 40% by weight (provided that synthetic fiber + hydrophilic fiber = 100% by weight),
Each layer relates to a desorption / release sheet characterized in that the layers are integrated by thermal bonding of synthetic fibers and have absorbability and release properties of a volatile component and / or a migratory component.
Here, as for the desorption / release sheet | seat of this invention, it is preferable that at least 1 layer is comprised with the nonwoven fabric among each layer.
In the desorption / release sheet of the present invention, at least 50% by weight or more of the synthetic fiber is made of a heat-adhesive fiber, and at least 50% by weight or more of the hydrophilic fiber is made of cellulosic pulp and / or Or what consists of rayon is preferable.
Such a desorption / release sheet is preferably heat-bonded by applying a temperature equal to or higher than the melting point of the heat-adhesive fiber, further subjected to a hot-pressure calendering process, or higher than the melting point of the heat-adhesive fiber. (A) Moisture is applied to the surface layer, and then hot-pressed calendering is performed.
In the desorption / release sheet of the present invention, the (A) surface layer or (C) back layer may be used as a carrier sheet, and the other layers may be formed by the airlaid method.

Since the desorption-release sheet | seat of this invention is comprised as mentioned above, there exist the following effects.
(1) By applying a fiber (SAF) made of a highly water-absorbing polymer (SAP), it is a disadvantage of powdery SAP, the lumpy feeling after absorbing and swelling, poor touch, hardness, texture The inconvenience is eliminated.
(2) By using hydrophilic fibers together with SAF, the increase in thickness due to swelling of SAF is alleviated without greatly impairing the water absorption performance, and the utility as a product is improved.
(3) As the hydrophilic fiber, pulp and rayon are suitable. Of these, when pulp is used, the water absorption rate is high and the water retention ability is high. On the other hand, when rayon is used, a product having high water resistance is obtained. It is done.
(3) Furthermore, water resistance can be improved by using a synthetic fiber together.
(4) The use of a heat-adhesive fiber as the synthetic fiber increases the strength of the sheet and increases the practicality.
(5) The surface layer (or the back surface layer) not containing SAF can protect and guard the highly water-absorbing layer (inner layer) and improve the handleability. In this case, the higher the ratio of synthetic fibers, the higher the surface strength and wear resistance, and the higher the ratio of hydrophilic fibers, the higher the water absorption performance. (It is preferable that the pulp ratio of the surface layer is low from the viewpoint of sustained release.)
(6) In the present invention, if (A) the front surface layer or (C) the back surface layer is used as the carrier sheet, the composite layer of the present invention can be efficiently formed by forming other layers by the airlaid method. it can.

(B) Inner layer The absorbent-absorbing / releasing sheet of the present invention has (B) inner layer as (a) synthetic fiber / (b) hydrophilic fiber / (c) superabsorbent fiber = 10 to 90/5 to 80/5. -80 wt% (however, (a) + (b) + (c) = 100 wt%).
As long as the inner layer contains (a) synthetic fiber, (b) hydrophilic fiber, and (c) superabsorbent fiber, the desorption / release sheet of the present invention may be a sheet produced by any method. That is, the inner layer (B) constituting the desorption / release sheet of the present invention may be any material as long as it is produced by a non-woven fabric production method such as an airlaid method, a dry nonwoven fabric method such as a card method, or a wet nonwoven fabric method. However, it is preferable to use a web layer formed by the airlaid method.

The (B) inner layer forms, for example, a web layer (inner layer) containing (a) synthetic fibers, (b) hydrophilic fibers, and (c) superabsorbent fibers (SAF) by the airlaid method. That is, a mixture containing the above components (a) to (c) is ejected from a single unit or a large number of ejection units located on a porous net conveyor, and is sucked by an air suction unit disposed on the lower surface of the net conveyor. A web layer (inner layer) is formed on a conveyor. At this time, if a back surface layer (or surface layer) to be a carrier sheet is placed in advance on the net conveyor, the web layer (inner layer) and the back layer (or surface layer) to be the carrier sheet at once Is obtained. Then, the surface part (or back layer) is laminated inline or outline, hot air treatment is applied, the fiber-bonding of the airlaid layer, the carrier sheet (back layer or surface layer) and the surface layer (or back layer) Is formed into a non-woven sheet.
The inner layer (B) may be formed in a multilayer structure of two or more layers when the components (a) to (c) are formed by the airlaid method. In this case, the components (a) to (c) The ratio may be the above ratio as a whole.
At this time, if the above-mentioned web layer is mixed with a heat-adhesive fiber as a synthetic fiber, effects such as fixing of powder and prevention of falling off and improvement of delamination strength can be expected.

(B) (a) Synthetic fiber used for the web layer which comprises an inner layer is provided for the integration of the sheet obtained, intensity | strength provision, water resistance provision, etc. This (a) synthetic fiber is a synthetic fiber other than (b) hydrophilic fiber and (c) superabsorbent fiber, and among them, a heat-adhesive fiber is preferably used. As the heat-adhesive fiber, a heat-adhesive conjugate fiber is suitable. For example, a core-sheath type in which a low melting point component is a sheath component and a high melting point component is a core component, a side-by-side type in which one is a low melting point and the other is a high melting point component. Examples of combinations of both components of these composite fibers include PP (polypropylene) / PE (polyethylene), PET (polyethylene terephthalate) / PE, PP / low-melting copolymer PP, PET / low-melting copolymer polyester, and the like. . Here, examples of the low-melting point copolyester include polyethylene terephthalate, polypropylene terephthalate, polybutylene terephthalate, etc. as a basic skeleton, aromatic dicarboxylic acids such as isophthalic acid and 5-metal sulfoisophthalic acid, adipic acid, and sebacic acid. And a modified copolymer with an aliphatic polycarboxylic acid such as diethylene glycol, diethylene glycol, propylene glycol, 1,4-butanediol and the like.

  The melting point of the thermal adhesive component, which is a low melting point component, is usually 100 to 160 ° C., preferably 110 to 155 ° C. When the temperature is lower than 100 ° C., the heat resistance of the nonwoven fabric is low, and thus the strength of the sheet may be weakened when it is used wet with warm water. On the other hand, when the temperature exceeds 160 ° C., it is necessary to increase the heat treatment temperature in the nonwoven fabric production process, the productivity is lowered, and it is not practical, and the adhesive effect in the heat integration between the web layer and the front and back layers cannot be expected.

Here, the fiber length of the heat-adhesive fiber is 3 to 10 mm, preferably 3 to 6 mm, when the web layer manufacturing method is the airlaid method. When the fiber length is less than 3 mm, the effect of increasing the strength is not sufficient. On the other hand, when the fiber length is more than 10 mm, the fibers tend to be entangled with each other, leading to deterioration of processability and texture. When the web production method is the card method, the fiber length is 30 to 100 mm, preferably 35 to 80 mm.
The fineness of the heat-adhesive fiber is 1 to 10 dtex, preferably 1.5 to 6.6 dtex. The fineness of the heat-adhesive fibers increases the number of constituent fibers in the case of thin fibers, and the resulting sheet is integrated, imparted strength, imparted water resistance, and more effective in fixing hydrophilic fibers and superabsorbent fibers. . However, in the case of less than 1 dtex, when forming a web by the airlaid method, thin fibers are easily entangled with each other, and mixing with other fibers becomes difficult, and the risk of uneven formation of the texture and occurrence of massive defects is greatly increased. Become. On the other hand, in the case of a thick fiber exceeding 10 dtex, it becomes a hard texture, so it is applied to the gentleness to humans, and the result is that the number of fibers is reduced even at the same mixing ratio. Water resistance imparting, and further, the fixing effect of hydrophilic fibers and superabsorbent fibers becomes inferior, and effects such as heat sealability are further diminished.

  (A) The ratio of the heat bondable fiber in a synthetic fiber becomes like this. Preferably it is 50-100 weight%, More preferably, it is 70-100 weight%. If it is less than 50% by weight, the shape retention of the entire inner layer (B) is lacking, and the sheet strength and delamination strength are lacking, and the practicality deteriorates.

In addition, (B) the synthetic fibers constituting the inner layer (B) include, for example, PP fibers, PET fibers, PBT fibers, nylon 6 fibers, nylon 6,6 fibers, aromatics as fibers other than the heat-adhesive fibers. Polyamide fiber, acrylic fiber, etc. may be mixed. In this case, it is preferable to keep the ratio of other fibers to 50% by weight or less. If it exceeds 50% by weight, not only the strength and heat sealability of the nonwoven fabric will be affected, but fibers without thermal adhesiveness will easily fall off during actual use.
(A) The fineness and fiber length of fibers other than the heat-adhesive fiber in the synthetic fiber are the same as those of the heat-adhesive fiber.

  (A) Synthetic fibers such as the above heat-bondable fibers may be crimped or not, and may be strand chops. When crimped, both zigzag-type two-dimensional crimped fibers and spiral-type and ohmic-type three-dimensional (three-dimensional) crimped fibers can be used.

In addition, you may use together a polyolefin-type synthetic pulp for the above (a) synthetic fiber.
Here, the polyolefin synthetic pulp is composed of, for example, a polyolefin in a high temperature and high pressure state, a polymer solvent selected from aliphatic hydrocarbons and / or aromatic hydrocarbons having a boiling point lower than that of water, and water. Dispersion that is at a temperature at which substantially all of the solvent evaporates and does not cause substantial evaporation of water when rapidly released into the vacuum zone, and is released through the nozzle into the vacuum zone. Then, the polyolefin is recovered as a fibrous material dispersed in water, and the fibrous material dispersed in water is obtained by beating or refining in a state where a surfactant is mixed. This method for producing a polyolefin-based synthetic pulp is described in detail in, for example, the claims in the first column of JP-B-52-47049, column 3, line 5 to column 19, line 25.
As the polyolefin synthetic pulp, those having an average fiber length of 0.5 to 3 mm and an average fiber diameter of 1 to 100 μm can be suitably used.
An example of this polyolefin synthetic pulp is SWP manufactured by Mitsui Chemicals.

  Since these polyolefin-based synthetic pulps have a multi-branched fiber structure (fibrillated, multi-branched and have a high specific surface area), (b) hydrophilic fibers and (c) have excellent characteristics of capturing highly water-absorbing fibers. . Further, when the substrate sheet is sprayed by the air laid method, a web layer in which the polyolefin synthetic pulp and (b) hydrophilic fibers (and (c) superabsorbent fibers) are integrated in the airflow is the sheet. It will be placed uniformly on top.

  (B) The ratio of the (a) synthetic fiber in the web layer which comprises an inner layer is 10-90 weight% in a component (a)-(c), Preferably it is 25-80 weight%. If it is less than 10% by weight, the effect of preventing (b) hydrophilic fibers and (c) superabsorbent fibers from being captured, fixed and prevented from falling off cannot be secured, and sheet strength and delamination strength are lacking. On the other hand, when it exceeds 90% by weight, not only the flexibility of the sheet after heat treatment is lost, but also (b) hydrophilic fibers and (c) high heat-absorbing fibers around many heat-adhesive fibers ( a) It becomes a state covered with a synthetic fiber, so that it is impossible to maintain the desorption / release property and the absorbability of moisture and liquid.

  The (b) hydrophilic fiber used in the inner layer (B) is defined as a fiber having an official moisture content specified in Table 1 of JIS L1030-2 of 10% by weight or more and less than 15% by weight. This (b) hydrophilic fiber absorbs, retains, and releases moisture and volatile components during actual use, and (c) assists the function and effect of the superabsorbent fiber (SAF). In the present invention, by using (c) superabsorbent fiber (SAF) together with (b) hydrophilic fiber, the increase in thickness due to the swelling of SAF can be alleviated without greatly impairing the water absorption performance, and practical use as a product. Improved.

(B) Examples of hydrophilic fibers include cellulosic pulp and rayon.
Among these, examples of the cellulose pulp include pulverized non-wood pulp such as linter pulp and bagasse in addition to wood pulp. Cellulosic pulp is characterized by a high water absorption rate and a high water retention capacity.
Cellulose pulp can be suitably used in the airlaid method by pulverizing sheet fluff pulp with a hammer mill or the like.
On the other hand, examples of rayon include viscose rayon, copper ammonia rayon, and saponified acetate silk, and viscose rayon is common. Rayon has high water resistance.
Rayon has a single yarn fineness of usually 1 to 10 dtex, preferably 1.2 to 6.6 dtex, and a fiber length of 3 to 10 mm, preferably 3 to 6 mm in the airlaid method. In the case of the carding method, the fiber length is 30 to 100 mm, preferably 35 to 80 mm.

  The ratio of the (b) hydrophilic fiber in the (B) inner layer is 5 to 80% by weight, preferably 10 to 70% by weight. If it is less than 5% by weight, it is not possible to obtain the effect of absorbing / holding and gradually releasing moisture during actual use and (c) assisting the function / effect of the superabsorbent fiber (SAF). On the other hand, if it exceeds 80% by weight, the sheet strength and heat seal strength are weakened and cannot be used, resulting in lack of practicality.

Further, (B) the superabsorbent fiber used in the inner layer (B) is a hygroscopic fiber that absorbs physiological saline at a water content of 1,200 wt% or more and less than 6,000 wt% at 20 ° C. and a relative humidity of 60%. A fiber having a property of 15% by weight or more is designated.
(C) Superabsorbent fiber (SAF), which is a fibrous superabsorbent polymer, is applied to the powdery superabsorbent polymer (SAP). , Poor texture, hardness, poor texture, etc. are resolved.

(C) Superabsorbent fibers include sodium polyacrylate, acrylic acid-vinylalkoxy copolymer, sodium polyacrylate cross-linked product, starch-sodium acrylate graft copolymer, isobutylene-maleic anhydride copolymer or In addition to fibers composed of the saponified product, a monomer having a carboxylic acid group, a monomer having a hydroxyl group and / or an amino group capable of reacting with the carboxylic acid group to form an ester crosslink, and an alkali metal carboxylate Examples thereof include fibers obtained by copolymerizing monomers having been crosslinked and thermally crosslinked (for example, OASIS manufactured by Technical Absorbents, or those described in paragraphs "0010" to "0017" of JP-A-6-207358).
The (c) superabsorbent fiber has a single yarn fineness of usually 2 to 20 dtex, preferably 5 to 15 dtex, and a fiber length of 3 to 10 mm, preferably 5 to 8 mm in the airlaid method. In the case of the carding method, the fiber length is 30 to 100 mm, preferably 35 to 80 mm.

  The proportion of the above (c) superabsorbent fibers in the inner layer (B) is 5 to 80% by weight, preferably 7 to 60% by weight. If it is less than 5% by weight, it has both a function of absorbing and absorbing water containing volatile components and migratory components applied to the sheet of the present invention, and a function of gradually releasing and releasing them. A desorbing / releasing sheet cannot be obtained. On the other hand, if it exceeds 80% by weight, the strength of the sheet, especially the wet strength, becomes weak and cannot be used, and heat sealability, delamination strength, etc. also decrease, and the moisture is absorbed in the air to swell the sheet. This is also undesirable because it causes problems such as

Here, the volatile component or the migratory component is a volatile, volatile, evaporative or migratory substance, for example, a moisturizer, deodorant, refreshing agent, fragrance, flame retardant, moisturizer, skin. Examples include nutritional supplements, preservatives, antibacterial agents, and plant-derived essential oils. If the content of these components in normal use is too small, there is no effect, and if too large, irritation and influence on human skin and instruments become strong, which is not preferable.
Among these, the volatile, volatile, and evaporable components include, for example, water, lower alcohols such as ethanol and isopropanol, fragrances, deodorants, refreshing agents, and mixtures thereof.
In addition, migratory components are substances that are difficult to volatilize but migrate when contacted with humans, instruments, furniture, etc. For example, moisturizers such as higher alcohols and glycerin, skin nutrition supplements, antiseptics, antibacterial agents And essential oils.

  Examples of the humectant include alkylene glycols (for example, ethylene glycol, propylene glycol, isoprene glycol, polyethylene glycol, polypropylene glycol, 1,3-butylene glycol, etc.), glycerins (for example, glycerin, diglycerin, triglycerin). , Polyglycerin, etc.), polyalkylene glycols, sugar alcohols, methylcellulose, urea, amino acids (glycine, alanine, aspartic acid, glutamic acid, arginine, serine, lysine, etc.), animal and plant derived components (hyaluronates, chondroitin sulfate) , Collagen, chitin / chitosan derivative, sodium alginate, isoflavone-containing plant extract, seaweed extract), oil component (castor oil, olive oil, sunflower oil, cacao oil, Mamm oil, coconut oil, soybean oil, rapeseed oil, coconut oil, liquid paraffin, petrolatums, natural and synthetic fatty acids such as lauric acid, myristic acid, stearic acid, oleic acid, isostearic acid, behenic acid, stearyl alcohol, hexyldecanol Natural and synthetic higher alcohols such as octyldodecanol and lauryl alcohol, and esters such as isopropyl myristate, octyldodecyl oleate and stearyl oleate).

Examples of the deodorant include natural product-derived components (tea leaf extract, persimmon tannin, peach extract, polyphenol, catechin, etc.), natural and artificial enzymes, ceramics, and the like.
Furthermore, examples of the refreshing agent include menthol, menthol derivatives, mint oil, camphor, thymol and the like.
Furthermore, examples of antibacterial / preservatives include various alcohols (ethanol, benzyl alcohol, etc.), benzoic acid, sodium benzoate, organic acids (citric acid, salicylic acid, etc.), quaternary ammonium salts, benzalkonium chloride, methylparaben. , Ethyl paraoxybenzoate, hinokitiol and the like.

  Examples of fragrances and fragrances include animal flavors (musk, ambergris, civet, castrium), vegetable flavors (rose oil, lemon oil, lavender oil, eucalyptus oil, orange oil, peppermint oil, peppermint oil. , Camphor oil, jasmine oil, camomil oil, ylang-ylang oil, anise seed oil, etc.) and various synthetic fragrances (nature-identical, artificial).

The inner layer (web layer) (B) formed by the airlaid method has a basis weight of 10 to 200 g / m ² , preferably 20 to 150 g / m ² . When it is less than 10 g / m ² , the resulting sheet has poor absorption and desorption properties, and the nonwoven fabric strength and heat seal strength are low, which is not suitable for practical use. On the other hand, if it exceeds 200 g / m ² , it is too thick and plate-like, and the flexibility is poor, which is not preferable.

  The airlaid method for producing the web layer of the present invention is extremely easy to use because of the short length of fibers that can be easily defibrated to a single fiber by air flow, compared to existing dry nonwoven fabric manufacturing methods such as the card method. Not only has a feature that a nonwoven fabric having a good texture, that is, good uniformity can be obtained, but also forms a web while mixing the components (a) to (b) and, in addition to this, the component (c). In addition, since a layered structure can be easily formed, it is suitable for the present invention. The airlaid method provides a nonwoven fabric with good uniformity, but it is difficult to obtain with an existing card method nonwoven fabric, a spunbond nonwoven fabric, and a melt blown nonwoven fabric. Moreover, according to this manufacturing method, there is also a merit that the vertical / horizontal strength ratio is close to 1/1.

(A) Surface layer, (C) Back surface layer In the desorption / release sheet of the present invention, (A) the surface layer and (C) the back surface layer protect, guard and handle the (B) inner layer which is a highly water absorbing layer. It plays the role of improving sex. In (A) surface layer [and (C) back layer], the higher the ratio of synthetic fibers, the higher the surface strength and wear resistance. On the other hand, the higher the ratio of hydrophilic fibers, the higher the water absorption performance. From the viewpoint of sustained release, it is preferable that (A) the surface layer has a low ratio of (b) hydrophilic fibers such as pulp.
Here, (a) synthetic fiber and (b) hydrophilic fiber used for (A) surface layer and (C) back layer are (a) synthetic fiber and (b) hydrophilic fiber used for (B) inner layer. Since this is the same, the description thereof is omitted.
Moreover, (A) front surface layer and (C) back surface layer are the same as (B) inner layer, by dry nonwoven fabric methods, such as an airlaid method and a card method, wet nonwoven fabric methods, a spunbond method, a melt blow method, etc. Any material can be used as long as it is manufactured, but a web layer formed by an airlaid method is preferable.

  (A) The surface layer is composed of (a) 20 to 100% by weight of synthetic fiber, preferably 40 to 100% by weight, (b) 80 to 0% by weight of hydrophilic fiber, preferably 60 to 0% by weight [however, (A) + (b) = 100 wt%]. When (a) synthetic fiber is less than 20% by weight [(b) hydrophilic fiber exceeds 80% by weight], surface abrasion resistance, sheet strength, heat seal strength during bag making, wet strength, delamination strength, etc. It will be lacking.

The surface layer (web layer) (A) formed preferably by the airlaid method has a basis weight of 10 to 100 g / m ² , preferably 12 to 70 g / m ² . When it is less than 10 g / m ² , the surface wear resistance, the sheet strength, the heat seal strength, and the sustained moisture release property are insufficient, which is not preferable. On the other hand, if it exceeds 100 g / m ² , it is too thick to be plate-like and poor in flexibility.

  On the other hand, (C) the back layer is composed of (a) 60 to 100% by weight of synthetic fiber, preferably 70 to 100% by weight, and (b) 40 to 0% by weight of hydrophilic fiber, preferably 30 to 0% by weight [ However, (a) + (b) = 100 wt%]. When (a) the synthetic fiber is less than 40% by weight [(b) the hydrophilic fiber exceeds 60% by weight], the sheet strength and the heat seal strength are lowered and the practicality is lacking.

The basis weight of the (C) back layer (web layer) preferably formed by the airlaid method is 10 to 100 g / m ² , preferably 12 to 70 g / m ² . When it is less than 10 g / m ² , the sheet strength and the heat seal strength are lowered. On the other hand, when it exceeds 100 g / m ² , the sheet is too thick to be plate-like and poor in flexibility.

Breathable sheet The desorption / release sheet according to the present invention is laminated and integrated with another breathable sheet as the front and back layers or in addition to the front and back layers in order to improve handling and strengthen the strength. Also good. The airlaid method is suitable because it can be combined at once as a carrier sheet.
The breathable sheet is preferably a sheet made of a heat-adhesive and water-resistant material, and it is preferable that the breathability is larger in order to laminate and integrate as an airlaid carrier sheet.
As the breathable sheet, preferably on the front and back of the desorption / release sheet, a spunlace nonwoven fabric, a thermal bond nonwoven fabric, an air-through nonwoven fabric, a spunbond nonwoven fabric, a melt blown nonwoven fabric, an airlaid nonwoven fabric, a wet fabric having a basis weight of 10 to 50 g / m ^2. At least one breathable sheet selected from the group of non-woven fabric, woven / knitted fabric, gauze, and cold chill is used.
In particular, since the spunlace nonwoven fabric is formed into a sheet shape by interlaced fibers, it has a feature that it is soft because less fiber / resin binder is required (or zero).
As a material for the breathable sheet, synthetic fibers such as polyester fiber, polypropylene fiber, and acrylic fiber have good water resistance and are strong.
When using the heat bonding method for integration with the inner layer, the breathable sheet may be used by mixing about 50% by weight or less of the heat bonding fiber used for the inner layer as the binder fiber.

Manufacturing method of desorbing / releasing sheet When making the desorbing / releasing sheet of the present invention by the airlaid method, first, a breathable sheet is placed on a net conveyor as a carrier sheet (when a breathable sheet is used), It is possible to easily form a composite sheet by depositing the web layer serving as the back surface layer and subsequently depositing the web layer serving as the inner layer.
For example, a breathable sheet is placed on a net conveyor, a web layer as a back layer is formed, a web layer as an inner layer is subsequently formed, and an airlaid nonwoven fabric as a surface layer is laminated inline or outline. .
Note that the breathable sheet is preferably a sheet made of a heat-adhesive and water-resistant material, and preferably has a large breathability. The airlaid method is a method in which a fiber layer is formed on a breathable material by ejecting a mixture of fibers and air from the top of the breathable material and drawing air from the bottom by suction. Air permeability is an important requirement. The air permeability according to JIS L1096 · A method (Gurley method) is preferably 0.5 to 2 seconds / 300 cc.
The basis weight of the breathable sheet is usually 10 to 50 g / m ² , preferably 12 to 40 g / m ² . If it is less than 10 g / m ^2, it is difficult to form a web layer, and the role of improving handleability and strengthening strength becomes dilute. On the other hand, when it exceeds 50 g / m ² , the whole is plate-shaped, which is not preferable.
In addition, the fineness of the fiber which comprises a breathable sheet is 0.1-8 dtex normally, Preferably it is 0.5-6.6 dtex.
By laminating the breathable sheet on the back layer and / or the surface layer of the sheet of the present invention, the handleability can be improved and the strength of the resulting sheet can be reinforced.

  In addition, when adopting an airlaid nonwoven fabric as a sheet used for the front and back layers, the same heat-adhesive fiber as that used for the inner layer is used from a single or a large number of sprayed portions located on the porous net conveyor. Including (a) synthetic fibers and (b) hydrophilic fibers, and forming a web layer as a surface layer on the net conveyor while sucking with an air suction portion arranged on the lower surface of the net conveyor, A web layer serving as an inner layer may be formed, and subsequently, a web layer serving as a surface layer may be formed using (a) synthetic fibers and (b) hydrophilic fibers including thermal adhesive fibers.

The synthetic fiber (a) may contain various additives or may be surface-treated. Examples include fragrances, colorants, antibacterial agents, deodorants, antifungal agents, and hydrophilizing agents.
These additives and surface treatment agents may be contained or treated in each of the web layers of the surface layer, the inner layer, and the back layer.

Integration of surface layer / inner layer and back layer / inner layer Integration with each of these layers may be performed after each layer is produced separately, or a multilayer structure may be formed all at once. In this case, the airlaid method is suitable.
Examples of the means for integration include (1) thermal bonding, (2) binder treatment, and (3) entanglement.
(1) Thermal bonding: Binder fibers are preferably included in each layer. Examples of the binder fiber include (a) a heat-adhesive fiber constituting the synthetic fiber.
(2) Binder treatment: Examples include hot melt resin melt spraying on the adherend surface, hot melt powder resin spraying / heat melting, liquid chemical binder coating or spraying, and heat treatment.
(3) Entangling: Surface layer / inner layer / back layer are integrally laminated and entangled by needle punching.
Of these integration processes, when at least the inner layer is produced by the airlaid method, for example, the back layer is used as a carrier sheet, the inner layer is formed by the airlaid method, and then the surface layer is overlaid and integrated by heat bonding, etc. Integration is the most preferable means. The details of this (1) heat treatment are as follows.

Heat Treatment It is preferable to heat-treat the sheet laminate comprising the surface layer / inner layer / back surface layer obtained as described above for the desorption / release sheet of the present invention. Examples of the heat treatment include hot air treatment and hot pressure treatment with low pressure after the hot air treatment.
Among these, as hot-air treatment for forming an interfiber bond, when a heat-adhesive conjugate fiber is used as the heat-adhesive fiber, a temperature equal to or higher than the melting point of the low-melting-point component of the conjugate fiber is required. However, if the melting point is 30 ° C. or higher than the melting point of the low melting point component, or the melting point of the high melting point component (the core component of the core-sheath type composite fiber or the high melting point component of the side-by-side type composite fiber), the heat shrinkage of the fiber. Is liable to be large, which leads to deterioration of the texture, and in extreme cases, it causes deterioration of the fibers, which is not preferable.
The hot air treatment temperature is usually 110 to 190 ° C, preferably 120 to 175 ° C.

In addition, dry heat calendering treatment , hot air treatment, hot pressure treatment under a low pressure, specifically, hot pressure calendering treatment may be added. As a roller used for the calendering treatment, it is preferable to use a pair of metal rollers having a smooth surface or a combination of a metal roller and an elastic roller in order to apply a uniform heat pressure to the whole, but a multi-stage roller may also be used. In addition, an embossing roller with an uneven surface may be used as long as the gist of the present invention is not impaired.

In the case of calendering, the pressure may be applied at any temperature from room temperature (non-heated) to high temperature if it is simply for thickness adjustment. The pressure can be appropriately selected to achieve a desired thickness. The temperature of the roller surface is higher than the melting point of the low-melting component of the heat-adhesive conjugate fiber so as to reinforce the thermal bond between the fibers with a hot-pressure calender and improve strength, surface abrasion resistance, delamination prevention, etc. Temperature is required. However, if the melting point is 30 ° C. or higher than the melting point of the low melting point component, or the melting point of the high melting point component (the core component of the core-sheath type composite fiber or the high melting point component of the side-by-side type composite fiber), the heat shrinkage of the fiber. Not only tends to be large, but also sticks to the roller surface and lacks processability. When the temperature is lower than the melting point, it is a matter of course that the reinforcement between the fibers is not sufficient.
The heat treatment temperature for reinforcing the fiber-to-fiber bond is usually 110 to 190 ° C, preferably 120 to 175 ° C.

  Moreover, if the linear pressure of the calendar process is set so as to be a uniform contact pressure in the width direction, an arbitrary pressure can be selected. In the case of high pressure, the density, non-woven fabric strength and interlayer strength increase, and the thickness decreases. In the case of low pressure, of course, an adverse effect occurs. If importance is attached to the strength of the nonwoven fabric, a high pressure is preferred as much as possible. If flexibility is important, low pressure is preferable. The linear pressure of the calendar process can usually be arbitrarily selected in the range of 10 to 500 N / cm. Moreover, you may provide arbitrary clearance gaps between a pair of rollers. When the temperature of the roller in contact with the surface layer is high, or when the pressure between the rollers is high, the surface state becomes smooth and becomes too rigid, which is not preferable.

Water application calendar treatment On the other hand, after applying a very small amount of water to the fiber layer, a heat pressure is applied by a calendar device to form hydrogen bonds between the hydroxyl groups of the cellulose fibers, thereby removing and releasing the sheet of the present invention. Can be obtained. A small amount of water may be sprayed on the fiber layer before calendering, and then passed through a thermal oven to generate hydrogen bonds between some celluloses in advance.

The application amount of water is 5 to 50% by weight, preferably 6 to 40% by weight, and more preferably 7 to 30% by weight with respect to the fiber layer. Further, the water at this time may be steam, and the use of steam increases the thermal efficiency. When the applied amount of water is less than 5% by weight, there are few hydrogen bonds between cellulose fibers, and the effect of increasing sheet strength is small. On the other hand, when the applied amount of water exceeds 50% by weight, it is necessary to evaporate the water sufficiently with multiple stages of hot-press calenders, but there is a risk that un-evaporated water remains and the hydrogen bonds between the cellulose fibers are strong. It becomes too paper-like and lacks flexibility.
Further, a water-soluble binder such as CMC (carboxyl methylcellulose) or partially saponified poval may be mixed with water in a small amount of 10% by weight or less.
Examples of the water application method include spraying, coating, and impregnation, but the method of hardly affecting the texture of the pulp layer is preferably a spraying method from one side or both sides.

  As a roller used for the calendar process, in order to apply a uniform heat pressure to the whole, it is preferable to use a pair of metal rollers having a smooth surface, but a multi-stage roller may be used. In addition, an embossing roller with an uneven surface may be used as long as the gist of the present invention is not impaired. In the calendar process, a method of processing a sheet having a desired thickness by adjusting the gap between the pair of heating rollers is preferable. In this case, the smaller the gap, the higher the pressure, which is preferable for imparting strength, but it is preferable to provide a gap for processing high-weight products. The gap is 0 to 3 mm, more preferably 0 to 2 mm.

  The temperature at the time of heat bonding by calendering is appropriately selected depending on the type of heat-adhesive synthetic fiber used and the overall basis weight, but is 100 to 200 ° C, preferably 110 to 190 ° C, and more preferably 120. ~ 180 ° C. When the hot-pressure treatment temperature is less than 100 ° C., it is less than the boiling point of water, so that hydrogen bonding between cellulose fibers is difficult to occur, and sheet strength does not appear. On the other hand, when the temperature exceeds 200 ° C., the cellulose fibers start to deteriorate, and conversely, the sheet strength becomes weak, which is not preferable.

  The linear pressure of the calendar process can be arbitrarily selected in the range of 10 to 500 N / cm depending on the desired texture. If it is less than 10 N / cm, hydrogen bonding between cellulose fibers is insufficient, while if it exceeds 500 N / cm, the density of the nonwoven fabric becomes too high, resulting in a hard texture.

In addition, although the thickness of the desorption / release sheet | seat of this invention obtained is 0.3-6 mm normally, Preferably it is 0.5-5 mm, However, It can set according to a use.
The total weight of the desorption / release sheet of the present invention is 30 to 500 g / m ² , preferably 35 to 300 g / m ² .

  Prior to use, the resulting desorption / release sheet of the present invention is a moisturizer, deodorant, freshener, fragrance, flame retardant, moisturizer, skin nutrition supplement, antiseptic, antibacterial agent, plant-derived essential oil. And the like are used in an amount of 1 to 500% by weight, preferably about 5 to 200% by weight, based on the weight of the sheet.

  EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated further more concretely, this invention is not limited to these Examples.

Example 1
First, as a surface layer, PET / PE composite fiber [PET (polyethylene terephthalate) / PE (polyethylene) -based heat-adhesive core-sheath composite fiber (manufactured by Teijin Fibers Ltd., 2.2 dt × 51 mm) 90 wt% And a rayon fiber (Omikenshi Co., Ltd., 3.3 dt × 51 mm) mixed at 10% by weight to produce a web by the card method, heated at 135 ° C. for 60 seconds with hot air, An air-through nonwoven fabric with a basis weight of 15 g / m ² was produced.
On the other hand, as a back layer, only PET / PE composite fiber [PET / PE heat-bondable core-sheath composite fiber (manufactured by Teijin Fibers Ltd., 2.2 dt × 5 mm)] (100 wt%) is 10 g / m ^2. It was formed on the net by the airlaid method.
Subsequently, as an inner layer, 20% by weight of PET / PE heat-adhesive core-sheath composite fiber (manufactured by Teijin Fibers Ltd., 4.4 dt × 5 mm), wood pulp (weyerhaeuser, NF405 ground product) 60% by weight, SAF, “OASIS Type 101, 10 dt × 6 mm” manufactured by Technical Absorbents is mixed to 20% by weight, and a total of 35 g / m ² of the web layer is formed on the back layer sheet by the airlaid method. Formed.
Further, the surface layer prepared in advance was placed on the inner layer, and the three layers were integrated by heating with hot air at 135 ° C. for 90 seconds by an air-through method.
The obtained sheet had a total basis weight of 60 g / m ² and a thickness of 1.2 mm.
The results are shown in Table 1.
The sheet was wet with water and squeezed lightly, and then the sheet was placed inside the mask so that the surface layer was on the face side, and a gauze was placed on the face side for use. Even after 4 hours from wearing, the moisture retention was maintained, there was moderate humidity, and breathing was easy.
On the other hand, when all the SAFs were replaced with pulp, it dried in about 1.5 hours and was not practical as a wet mask.

Example 2
PP-SMMS (polypropylene spunbond / meltblown / meltblown / spunbond composite nonwoven fabric) (manufactured by Asahi Kasei Corporation, PMA015, basis weight 15 g / m ² ) was used as a carrier sheet (breathable sheet) in the airlaid method. .
On this carrier sheet, as a back layer, 80% by weight of PET / PE-based heat-adhesive core-sheath type composite fiber (manufactured by Teijin Fibers Ltd., 2.2 dt × 5 mm), wood pulp (manufactured by Weyerhaeuser, NF405) And a total of 12 g / m ² of a web layer was formed on the carrier sheet by the airlaid method.
Furthermore, as an inner layer, 30% by weight of PET / PE-based heat-adhesive core-sheath composite fiber (manufactured by Teijin Fibers Ltd., 4.4 dt × 5 mm), wood pulp (manufactured by Weyerhaeuser, NF405) Product) 50% by weight, SAF, “OASIS Type 101, 10 dt × 6 mm” manufactured by Technical Absorbents was mixed to 20% by weight, and a total of 25 g / m ² of the web layer was formed by the airlaid method. Formed on top.
Furthermore, on this inner layer, as a surface layer, PET / PE-based heat-adhesive core-sheath composite fiber (manufactured by Teijin Fibers Ltd., 2.2 dt × 5 mm) is 80% by weight, wood pulp (manufactured by Weyerhaeuser, NF405 ground product) is mixed to 20% by weight, and a web layer of a total of 10 g / m ² is formed on the inner layer sheet by the airlaid method, and then heated and integrated at 135 ° C. for 90 seconds in a hot air oven. After that, it was further embossed with a dot-like embossing roller (metal / metal) of 80 ° C. × linear pressure 100 N / cm to improve the tensile strength and the surface wear resistance.
The obtained sheet had a total basis weight of 62 g / m ² and a thickness of 0.7 mm.
The results are shown in Table 1.
In addition, this sheet was impregnated with distilled water containing 5% by weight of tea leaf extract deodorant (manufactured by Shiraimatsu Shinyaku Co., Ltd., FS-500M) twice the weight of the sheet as a furniture wiper. used. It was effective as a deodorant wet wiper even after 30 minutes in a 55% humidity room.
On the other hand, those without SAF were air-dried in about 15 minutes.

Example 3
First, as a surface layer, a PET / PE composite fiber [PET (polyethylene terephthalate) / PE heat-bondable core-sheath composite fiber (manufactured by Teijin Fibers Ltd., 4.4 dt × 51 mm)] 50% by weight and rayon Fiber (Ohmi Kenshi Co., Ltd., 3.3 dt × 51 mm) mixed at 50 wt% to produce a web by the card method, and then a pair of metal / cotton hot pressures at 140 ° C. and linear pressure of 100 N / cm A nonwoven fabric with a basis weight of 15 g / m ² of a card thermal bond method (hot pressure calendar) was produced by heat pressure treatment with a calender.
On the other hand, a 20 μm-thick perforated polyethylene film (manufactured by Mitsubishi Chemical Corporation, basis weight 15 g / m ² ) was prepared as a breathable sheet.
Here, as a back layer, only PET / PE composite fiber [PET / PE-based heat-bondable core-sheath composite fiber (manufactured by Teijin Fibers Ltd., 4.4 dt × 5 mm)] (100 wt%) is 15 g / m. ^A web was formed on the net by the airlaid method so as to be ² .
Next, PP (polypropylene) / PE-based heat-adhesive core-sheath composite fiber (manufactured by Chisso Corp., 11 dt × 5 mm) is 45% by weight, wood pulp (manufactured by Weyerhaeuser, NF405) as an inner layer. ) 25% by weight, SAF, “OASIS Type 101, 10 dt × 6 mm” manufactured by Technical Absorbents is mixed to 30% by weight, and a total of 35 g / m ² of the web layer is formed on the back layer sheet by the airlaid method. Formed.
Further, the surface layer prepared in advance was placed on the inner layer, and the three layers were integrated by heating with hot air at 135 ° C. for 90 seconds by an air-through method.
Further, the surface of the integrated back layer was sprayed with an olefin-based hot melt adhesive [manufactured by Matsumura Oil Research Co., Ltd., Morescommelt TN715] to 2 g / m ^2, and from the perforated polyethylene film A breathable sheet was laminated and integrated.
The sheet thus obtained had a total basis weight of 80 g / m ² and a thickness of 1.9 mm.
The results are shown in Table 1.
This sheet was used as a drip absorber for meat. That is, this absorbent body was placed on a PP tray, and a lump of pork thigh was placed on 250 g thereon, and the whole was sealed with a wrap to absorb the drip solution. Even after 24 hours, moderate moisture was maintained inside and the meat remained fresh.
On the other hand, when the one without SAF was used, discoloration of the meat occurred.

Example 4
First, a PET / PE composite fiber [PET / PE heat-bondable core-sheath composite fiber (manufactured by Teijin Fibers Ltd., 2.2 dt × 51 mm) 90% by weight and rayon fiber (Omikenshi Co., Ltd.) is used as the back layer in advance. ), 3.3 dt × 51 mm) A web is prepared by the card method by mixing so as to be 10% by weight, heated by hot air at 135 ° C. for 60 seconds by an air-through method, and the weight of the card / air-through method is 25 g / m. ² nonwoven fabrics were produced.
The back layer prepared in advance was used as a carrier sheet, and on this carrier sheet, a PET / PE-based thermoadhesive core-sheath composite fiber (manufactured by Teijin Fibers Ltd., 4.4 dt × 5 mm) was used as an inner layer. ) 60% by weight, wood pulp (manufactured by Weyerhaeuser, NF405 ground product) 30% by weight, SAF, “OASIS Type 101, 10 dt × 6 mm” manufactured by Technical Absorbents, and mixed to 10% by weight. A web layer of 40 g / m ² was formed on the back layer sheet by the airlaid method.
Furthermore, on this inner layer, as a surface layer, only PET / PE-based heat-adhesive core-sheath composite fiber (manufactured by Teijin Fibers Ltd., 2.2 dt × 5 mm) (100 wt%), 25 g / m ² A web layer is formed on the inner layer sheet by the airlaid method, and then heated and integrated at 135 ° C. for 90 seconds in a hot air oven, and further with a flat roller (metal / metal) of 120 ° C. × linear pressure of 500 N / cm. The flat calendar was processed.
The obtained sheet had a total basis weight of 90 g / m ² and a thickness of 0.7 mm.
The results are shown in Table 1.
Using this sheet, a small amount of a fragrance (Paris Fragrance, “Paris Hilton”) was added to the cocoon extract-based deodorant (Release Kagaku Kogyo Co., Ltd., Pancil FG-60). Was sprayed to give 5 g / m ² . When this sheet (20 cm ² ) was affixed to the inner wall surface of a shoe box used by four people every day, there was no odor and the fragrance was maintained for almost 3 weeks. Thereafter, when the spray solution was further applied, the performance was maintained for another 3 weeks.

  In addition to food drip sheets, wet wipers, hygiene absorbers, moisturizing sheets, face masks, wet masks, cosmetic sheets, and the like, the deodorizing / releasing sheet of the present invention can also be used in living environments such as residences, furniture, tools, It can be used for a sheet applied to various appliances that are provided with an action such as deodorization, aroma, humidification, moisturizing, antibacterial, etc. by placing it on a domestic device, portable device, automobile or the like.

Claims (5)

(A) Synthetic fiber (however, excluding hydrophilic fibers and superabsorbent fibers described later; the same applies hereinafter) / hydrophilic fiber = 100-20 / 0-80% by weight (however, synthetic fiber + hydrophilic fiber = 100% by weight) ) Surface layer,
(B) Synthetic fiber / hydrophilic fiber / superabsorbent fiber = 10-90 / 5-80 / 5-80% by weight (however, synthetic fiber + hydrophilic fiber + superabsorbent fiber = 100% by weight) And (C) a synthetic fiber / hydrophilic fiber = 100 to 60/0 to 40% by weight (provided that synthetic fiber + hydrophilic fiber = 100% by weight),
Of these synthetic fibers, at least 50% by weight or more is composed of heat-adhesive fibers,
The desorption / release sheet, wherein each layer is integrated by thermal bonding of synthetic fibers, and has absorbability and release of a volatile component and / or a migratory component.   The desorption-release sheet | seat of Claim 1 in which at least 1 layer is comprised with the nonwoven fabric among each layer. The desorbing / releasing sheet according to claim 1 or 2, wherein at least 50% by weight or more of the hydrophilic fibers is made of cellulosic pulp and / or rayon. After applying a temperature higher than the melting point of the above-mentioned heat-adhesive fiber to heat-bond, or further applying a hot-pressure calendering process, or after applying a temperature higher than the melting point of the heat-adhesive fiber and heat-bonding, (A 4) A desorbing / releasing sheet according to any one of claims 1 to 3 , which is obtained by applying moisture to the surface layer and then subjecting it to a hot-pressure calendering treatment. The method for producing a desorption / release sheet according to any one of claims 1 to 4, wherein (A) the front surface layer or (C) the back surface layer is used as a carrier sheet, and other layers are formed by an airlaid method. .