JP4293895B2 - Laminated nonwoven fabric and abrasive nonwoven fabric - Google Patents

Description

  The present invention relates to a laminated nonwoven fabric having a unique surface touch, excellent handleability such as handling, and excellent productivity. Specifically, the present invention relates to a polishing nonwoven fabric that can be used for polishing, wiping off dirt, oil, rust, and the like of metals, ceramics, plastics, glass, leather and the like.

  Conventionally, powders of aluminum oxide, iron oxide, zeolite, calcium carbonate, etc. are generally used as abrasives for polishing and wiping dirt, oil, rust, etc. on metals, ceramics, plastics, glass, leather, etc. An abrasive cloth used by adhering to a cloth such as a nonwoven fabric is known. In addition to the above, for example, in Japanese Patent Laid-Open No. 5-56901 (Patent Document 1), without using an abrasive, a lump-like solid is formed on the surface of a fiber constituting the nonwoven fabric, and the unevenness is polished. A polishing sheet that can be used has been proposed.

JP-A-5-56901

  However, the polishing cloth and the polishing sheet have the following problems. Abrasive cloth with an abrasive fixed by an adhesive is excellent in abrasiveness by the abrasive, but not only requires an abrasive and an adhesive, but the abrasive is separated from a non-woven fabric manufacturing process. It is necessary to produce it, and the cost becomes high.

  In addition, the polishing sheet described in JP-A-5-56901 is obtained by heat-treating a fiber web in which the fibers constituting the sheet are a mixture of a first fiber having a low melting point and a second fiber having a high melting point. Only the fiber is melted, and the second fiber having a high melting point is left as a skeletal fiber to form a knob-like solid. Another polishing sheet described in JP-A-5-56901 is a heat treatment of a composite fiber web composed of a low melting point component and a high melting point component, which is higher than the melting point of the low melting point component and lower than the melting point of the high melting point component. Heat treatment is performed at a temperature to form a knob-like solid in which the low melting point component is melted on the high melting point component so that the high melting point component becomes a skeleton fiber. However, in the polishing sheets, the proportion of the whole of the knob-shaped solid is not sufficient and the polishing power is weak. Furthermore, since the size of the lumpy solid also has skeletal fibers, only a small lumpy solid was obtained and the polishing power was weak.

  In addition, the polishing sheet melts only the first fibers, so that it has a unique surface touch, but since the entire nonwoven fabric is softly finished, handling properties such as handling properties may be inferior, and the use must be limited. There was no actual situation.

  The present invention has a unique surface touch that can be adapted to various uses, and is excellent in handling properties such as handling properties, laminated nonwoven fabric excellent in productivity, and inexpensive, excellent in polishing properties and wiping properties. Another object of the present invention is to provide a polishing nonwoven fabric that can be used for metals, ceramics, plastics, glass, leather, and the like.

  The laminated non-woven fabric of the present invention has a surface layer forming a porous molten solid in which heat-fusible fibers are completely melted and gathered together, and a heat resistance having a melting point or decomposition point higher than the melting point of the molten solid A heat-resistant fiber layer containing fibers and a reinforcing fiber layer are arranged on at least one surface of the heat-resistant fiber layer.

  The abrasive non-woven fabric of the present invention has a surface layer that forms a porous molten solid in which heat-fusible fibers are completely melted and gathered together, and a heat resistance that has a melting point or decomposition point that is higher than the melting point of the molten solid. A heat-resistant fiber layer containing fibers and a laminated nonwoven fabric in which a reinforcing fiber layer is disposed on at least one surface of the fiber layer, and the thickness of at least one molten solid forming the surface layer is 0.15 mm or more It is characterized by being.

  The laminated nonwoven fabric of the present invention has a surface layer that forms a porous molten solid in which heat-fusible fibers are completely melted and gathered together, and therefore has a unique surface touch that is rugged and hard. For example, when the surface layer is pressed against an adhesion surface such as dirt and wiped, a polishing nonwoven fabric excellent in polishing properties and wiping properties can be obtained. Moreover, since the laminated nonwoven fabric of the present invention is excellent in handling properties such as handling properties by arranging the reinforcing fiber layer, for example, when wiping the adhesion surface such as dirt, a polishing nonwoven fabric excellent in wiping workability is provided. can get. Further, since it has a fiber layer containing a heat-resistant fiber having a melting point or decomposition point higher than the melting point of the molten solid and a reinforcing fiber layer, rapid shrinkage occurs during heat treatment for completely melting the heat-fusible fiber. When a heat treatment machine such as a pin tenter is used at the time of heat treatment, it has excellent productivity such as having a reinforcing fiber layer to improve gripping properties.

  The polishing nonwoven fabric of the present invention can polish metals, ceramics, plastics, glass, leather and the like without using an abrasive in combination with a conventional polishing cloth. In addition, solid stains such as oil stains, soy sauce, sauces, etc. attached to a cooking device, and spilled traces of pots can be easily removed. In addition to objectives, skin such as human limbs can be easily wiped with grease, lubricating oil and other machine oils, dust stains, paint stains, and the like alone or with an abrasive or solvent.

  The present invention has a unique surface touch that is rugged and hard when the heat-fusible fibers constituting the surface layer of the nonwoven fabric are completely melted to form a porous molten solid aggregated together, and the reinforcing fibers The arrangement of the layers has been found to improve handling properties such as handling properties and productivity when forming the molten solid, and have led to the present invention. That is, the laminated nonwoven fabric of the present invention has a surface layer that forms a porous molten solid in which heat-fusible fibers are completely melted and gathered together, and a melting point or decomposition point that is higher than the melting point of the molten solid. A heat-resistant fiber layer containing heat-resistant fibers and a reinforcing fiber layer are disposed on at least one surface of the fiber layer. In the present invention, “the heat-fusible fiber is completely melted” means that the resin that is melted by heat is processed at a temperature equal to or higher than the melting point, and the component that is not melted by heat in the heat-fusible fiber ( For example, even if it contains an inorganic substance, etc., it is a concept including them as long as the surface touch of the nonwoven fabric of the present invention is not inhibited.

  The surface layer is formed of a porous molten solid in which heat-fusible fibers are completely melted and gathered together. The term “porous molten solid aggregated together” as used herein means that when the heat-fusible fibers are completely melted, the adjacent heat-fusible fibers are closely gathered due to the shrinkage action caused by melting. This refers to an aggregate that has been shrunk and aggregated into a certain portion and apparently becomes porous and solidified. Moreover, it is preferable that a molten solid forms the molten solid which spreads in the porous shape which rose up | protruded in the uneven | corrugated shape. In such a form, the heat-fusible fiber is completely melted and adheres to the adjacent heat-resistant fiber and shrinks. Therefore, the molten resin is pulled in the part that is not adhered to the heat-resistant fiber or the weakly adhered part. It is presumed that the melted resin around it gathers into a convex part at the part strongly bonded to the heat-resistant fiber. Alternatively, in the fiber web including the heat-fusible fibers constituting the surface layer, the portions where the heat-fusible fibers are densely gathered are more densely gathered by the action of shrinkage when heat-treated, and the convex portions are formed. Estimated to form. As a result, the surface layer of the laminated nonwoven fabric according to the present invention is hard and rugged and has a unique surface touch. When the laminated nonwoven fabric of the present invention is used as a wiper such as a polishing nonwoven fabric, it has excellent polishing properties and wiping properties.

  Moreover, it is preferable that the said reinforcement fiber layer takes the structure formed by arrange | positioning on the inner surface side of the said surface layer. The reinforcing fiber layer is stronger in bonding between fibers in the fiber layer than the heat-resistant fiber layer, and is excellent in dimensional stability. Therefore, the fibers of the heat-fusible fibers constituting the surface layer and the fibers constituting the reinforcing fiber layer are entangled more than necessary, and the heat-fusible fibers do not enter the interior, and are appropriately entangled. It is presumed that more heat-fusible fibers are exposed on the surface layer, and the unevenness of the molten solid formed by melting completely becomes clearer. In particular, when the heat-fusible fibers constituting the surface layer and the fibers constituting the reinforcing fiber layer are entangled three-dimensionally, molten solids gather around the fibers constituting the reinforcing fiber layer and become porous. It is easy to be in the form of a shape and is preferable. The three-dimensional entanglement is preferably water entanglement and / or needle punch entanglement. In addition, in the said surface layer, the surface where a surface layer contacts a target object was made into the surface, and the surface which contacts another fiber layer was made into the inner surface.

  The heat-fusible fiber may be either a single component fiber or a multicomponent composite fiber. Among them, composite fibers consisting of multiple components with different melting points have a shrinkage difference between the components when heat-treated, so one component is heat-treated at a temperature considerably higher than the melting point to form a hard molten solid. Even so, since the other component is heat-treated at a relatively close temperature, which is higher than the melting point, the shrinkage of the entire nonwoven fabric can be suppressed, which is preferable. When a composite fiber composed of a plurality of components having different melting points is composed of a low melting point component and a high melting point component, a resin having a melting point lower than the melting point or decomposition point of the heat resistant fiber may be used as the high melting point component.

  Examples of the heat-fusible fiber include aromatic polyesters such as polyethylene terephthalate, polybutylene terephthalate, and copolymers thereof, polyethylene succinate, polybutylene succinate, polylactic acid, and fats such as copolymers thereof. Examples thereof include fibers mainly composed of polyamide such as group polyester, nylon 6, nylon 66, or a copolymer thereof, and polyolefin such as polyethylene, polypropylene, polybutene-1, or a copolymer thereof. Considering the processing temperature of a general-purpose heat treatment machine, fibers having a melting point of 200 ° C. or less as a main component are copolymerized polyester, aliphatic polyester, and polyolefin.

  When the heat-fusible fiber is a composite fiber composed of a plurality of components having different melting points, examples of the composite form include (eccentric) sheath-core type, parallel-type, split-type, sea-island type, etc. This composite fiber is preferable because a nonwoven fabric having a high degree of polishing and wiping properties can be obtained while suppressing shrinkage of the nonwoven fabric. In particular, the effect is remarkable in the sheath-core type composite fiber in which the sheath component is a low-melting-point component and the core component is a high-melting-point component whose melting point is 10 ° C. higher than the low-melting-point component. Specific configurations of the composite fiber include a combination of aliphatic polyesters having different melting points, aliphatic polyester and copolymerized aromatic polyester, polyethylene and polypropylene, polybutene-1 and polypropylene, ethylene-vinyl acetate copolymer and polypropylene. , Ethylene- (meth) acrylic acid (ester) copolymer and polypropylene.

  As the resin constituting the heat-fusible fiber, polybutene-1 resin is preferable because of its excellent abrasiveness and wiping property. The polybutene-1 resin may be either alone or in combination with other resins, but when the polybutene-1 resin is melt-spun alone, the spinnability is not so good, but it is compounded with other polyolefin resins. As a result, the spinnability can be improved. Therefore, it is preferable that a composite fiber having a polybutene-1 resin and another polyolefin resin having a melting point higher than that of the polybutene-1 resin is melted and solidified on the surface of the nonwoven fabric because excellent polishing properties and wiping properties are obtained.

  Examples of other polyolefin resins constituting the composite fiber in combination with the polybutene-1 resin include propylene, methylpentene, hexene and copolymers thereof having a melting point higher than that of the polybutene-1 resin. Especially, what uses polybutene-1 resin, a polypropylene resin, or its copolymer as a structural component is preferable at the point of the workability of a fiber and a nonwoven fabric.

  The cross-sectional area ratio (low melting point component: high melting point component) of the low melting point component and high melting point component in the composite fiber is preferably 15:85 to 80:20. By setting the cross-sectional area ratio, it is possible to obtain a sufficient nonwoven fabric surface hardness when the spinning process stability and the heat-fusible fibers are melted and solidified during the processing of the nonwoven fabric. A more preferable cross-sectional area ratio (low melting point component: high melting point component) is 40:60 to 60:40. A more preferable cross-sectional area ratio is 45:55 to 55:45.

  The fineness of the heat-fusible fiber is preferably in the range of 1 dtex or more and 10 dtex or less. A more preferable lower limit of the fineness is 3 dtex. A more preferable upper limit of the fineness is 6 dtex. When the fineness of the heat-fusible fiber is less than 1 dtex, the thickness of the molten solid tends to be small. For example, when used for a non-woven fabric for polishing, there is a possibility that the abradability is lowered. When the fineness exceeds 10 dtex, the molten solid tends to be a non-uniform lump, and the target surface may be damaged more than necessary.

  The proportion of the heat-fusible fiber in the fibers constituting the surface layer is preferably 70 mass% or more. A more desirable ratio is 80 mass% or more. A more desirable ratio is 90 mass% or more. Most preferably, the entire surface layer is occupied by heat-fusible fibers. This is because, when the content of the heat-fusible fiber is less than 70 mass%, a hard and unique surface touch that is rough cannot be obtained, and for example, the abrasiveness and the wiping property tend to decrease.

  The heat resistant fiber layer is composed of a fiber layer containing heat resistant fibers having a melting point or decomposition point higher than the melting point of the molten solid. That is, the heat resistant fiber refers to a fiber having a melting point or decomposition point higher than the melting point of the heat-fusible fiber. The melting point or decomposition point of the preferred heat resistant fiber is a fiber that is 30 ° C. higher than the melting point of the heat-fusible fiber. If the melting point or decomposition point of the heat-resistant fiber is lower than the melting point of the heat-fusible fiber, not only may there be shrinkage during the processing of the nonwoven fabric, but the desired form of the nonwoven fabric surface layer may not be obtained.

  Examples of the heat-resistant fiber include polyester fibers such as polyethylene terephthalate and polybutylene terephthalate having a high melting point, polyamide fibers such as nylon, acrylic fibers, polymethylpentene fibers, and copolymers of these. Non-thermoplastic fibers may also be used, and examples thereof include regenerated fibers such as viscose rayon and solvent-spun rayon, and natural fibers such as cotton, pulp and hemp. In particular, when the above-mentioned recycled fiber, natural fiber, or synthetic fiber imparted with hydrophilicity is used, water absorption is obtained in the nonwoven fabric itself. Therefore, the laminated nonwoven fabric is used by dissolving or dispersing a cleaning agent, an abrasive, or the like in a liquid. Sometimes it is advantageous.

  The reinforcing fiber layer is selected from fiber layers that are stronger in bonding between fibers than the heat-resistant fiber layer and excellent in dimensional stability. The reinforcing fiber layer is preferably a heat-bonded fiber layer in which at least a part of the constituent fibers is bonded by self-bonding or pressure bonding or other components. Specific examples include an air-through nonwoven fabric, a point bond nonwoven fabric, a spunbond nonwoven fabric, a history orthogonal nonwoven fabric, a wet nonwoven fabric, a chemical bond nonwoven fabric, and a net-like material. Since the point bond nonwoven fabric and the spun bond nonwoven fabric partially have a thermocompression bonding portion, when the layers described later are laminated and entangled and integrated by hydroentanglement, the thermocompression bonding portion does not penetrate the water flow, so thermocompression bonding is performed. The fiber group laminated | stacked on the part will be rearranged, and will be in the state which does not exist substantially. As a result, the molten solid formed on the surface layer is usually formed randomly, but according to the above method, it appears to exist in parts other than the thermocompression bonding part, and it is possible to form a fixed pattern. It is. Of the reinforcing fiber layers, spunbonded nonwoven fabrics are particularly preferred because they are versatile and easily obtain heat-resistant nonwoven fabrics.

  The reinforcing fiber layer is preferably a heat-resistant fiber, like the heat-resistant fiber layer. Examples thereof include polyester fibers such as polyethylene terephthalate and polybutylene terephthalate, polyamide fibers such as nylon, acrylic fibers, polymethylpentene fibers, and copolymers of these.

  The reinforcing fiber layer is disposed on at least one surface of the heat resistant fiber layer. By disposing the reinforcing fiber layer, the laminated nonwoven fabric itself is reinforced, and the laminated nonwoven fabric having dimensional stability and excellent handling properties such as handling properties can be obtained. The reinforcing fiber layer is preferably arranged on the inner surface side of the surface layer. The reason is as described above.

  Next, the manufacturing method of the laminated nonwoven fabric of this invention is demonstrated. In order to form the surface layer and the heat-resistant fiber layer, a fiber web is prepared for each layer. Examples of the form of the fiber web include a card web, an air lay web, a spunbond web, and a melt blow web. Among them, the card web is preferable because it can be easily entangled three-dimensionally.

The basis weight of the fiber web constituting the surface layer is preferably in the range of 10 g / m ² or more and 80 g / m ² or less. A more preferable lower limit of basis weight is 20 g / m ² . A more preferable upper limit of the basis weight is 50 g / m ² . When the basis weight of the fiber web constituting the surface layer is less than 10 g / m ² , the molten solid matter is reduced, and for example, the polishing property and the like may be lowered. Furthermore, the texture of the fiber web may be poor and the molten solid may become a non-uniform mass. When the basis weight of the fiber web constituting the surface layer exceeds 80 g / m ² , there is a possibility that the molten solid becomes a non-uniform lump.

The basis weight of the fiber web constituting the heat-resistant fiber layer may be appropriately set according to the application of the target surface to be used, but is preferably in the range of 10 g / m ^{2 to} 100 g / m ² . A more preferable lower limit of basis weight is 20 g / m ² . A more preferable upper limit of the basis weight is 60 g / m ² . When the basis weight of the fiber web constituting the fiber layer is less than 10 g / m ² , the texture of the fiber web may be deteriorated, or the impregnation property is used when the nonwoven fabric is impregnated with moisture or chemicals. May get worse. If the basis weight of the fiber web constituting the fiber layer exceeds 100 g / m ² , there is a possibility that the entanglement between the layers when the hydroentanglement treatment is performed is lowered.

On the other hand, as the reinforcing fiber layer, for example, a heat-bonded nonwoven fabric in which at least a part of fibers constituting an air-through nonwoven fabric, a point bond nonwoven fabric, a spunbond nonwoven fabric, or the like is fused or pressed is prepared. The basis weight of the reinforcing fiber layer is preferably in the range of 10 g / m ² or more and 70 g / m ² or less. A more preferable upper limit of the basis weight is 30 g / m ² . If the basis weight of the reinforcing fiber layer is less than 10 g / m ² , a sufficient reinforcing effect may not be obtained. If the basis weight of the reinforcing fiber layer exceeds 70 g / m ² , the entanglement with each layer may be lowered.

Each of the layers is laminated so that the fiber web constituting the surface layer becomes at least one surface layer of the nonwoven fabric. The laminate may be subjected to heat treatment as it is, but is preferably subjected to hydroentanglement treatment and / or needle punch treatment. By performing hydroentanglement treatment and / or needle punching treatment, the fibers constituting each layer are entangled three-dimensionally, and the fibers of adjacent layers are simultaneously entangled three-dimensionally so that the layers are integrated. And entangled nonwoven fabric. In particular, when the basis weight of the laminated nonwoven fabric to be obtained is 200 g / m ² or less, it is preferable to perform hydroentanglement treatment.

  And after the said entangled nonwoven fabric dries as needed, it is the temperature more than melting | fusing point of the component which comprises a heat-fusible fiber, and less than melting | fusing point or decomposition point of the fiber which comprises a heat resistant fiber layer and a reinforcement fiber layer The heat-fusible fiber can be completely melted by heat treatment at a temperature. A preferable heat treatment temperature is the melting point of the component constituting the heat-fusible fiber + 20 ° C. or less. If the heat treatment temperature is lower than the melting point of the component constituting the heat-fusible fiber, the heat-fusible fiber cannot be completely melted. On the other hand, when the heat treatment temperature is equal to or higher than the melting point or decomposition point of the heat resistant fiber, the nonwoven fabric may be rapidly contracted when the heat resistant fiber itself is melted or decomposed. Moreover, the length of the molten solid formed may be reduced, and the polishing properties and wiping properties may be reduced. Examples of the heat treatment method include an air through method and a far infrared heating method. After the heat treatment, the laminated nonwoven fabric of the present invention is obtained by forcibly or naturally cooling.

  A preferable use of the obtained laminated nonwoven fabric is a polishing nonwoven fabric. The nonwoven fabric for polishing of the present invention is composed of the laminated nonwoven fabric, and the thickness of at least one molten solid forming the surface layer is 0.15 mm or more. By containing the molten solid satisfying the above range, it is possible to obtain a non-woven fabric having excellent polishing properties and excellent wiping properties. A preferable lower limit of the thickness of the molten solid is 0.2 mm. A preferable upper limit of the thickness of the molten solid is 1 mm. A more preferable upper limit of the thickness of the molten solid is 0.5 mm. It is preferable that the molten solid having a thickness of at least one molten solid of 0.15 mm or more occupies 50% or more on at least one surface (one side). As for the thickness of the molten solid, when viewed from the cross section of the porous molten solid, there is a large difference in height between the raised portion (convex portion) of the molten solid and the hole, that is, a large convex portion is formed. It is shown that. As the thickness of the molten solid is increased, the polishing property and the wiping property tend to be improved. The method for calculating the thickness of the molten solid and the proportion of the molten solid having a thickness of 0.15 mm or more occupying at least one surface (one side) was performed as follows. First, a cross section in the longitudinal direction (machine direction) of the nonwoven fabric is magnified about 50 times with an electron microscope or the like, and images are taken arbitrarily at 10 locations. As for the thickness of the molten solid, the length between the surface (bottom surface) where the molten solid and the fiber layer are in contact with each other and the highest position (top) where the molten solid is raised was obtained from the 10 positions taken. The ratio of the molten solid having a thickness of 0.15 mm or more was set to 0. 0 with respect to the total number of molten solids when the number of the photographed 10 portions where the cut surface of the molten solid appeared was 1 count. The ratio of the count number of the molten solid having a thickness of 15 mm or more was determined.

  Furthermore, it is preferable that the molten solid includes one having a length in one direction of 1 mm or more. More preferably, the length of the molten solid in one direction is 2 mm or more. Moreover, it is preferable that the molten solid substance whose length of one direction is 1 mm or more occupies 80% or more of the nonwoven fabric surface. The greater the length of the molten solid or the greater the proportion of the molten solid that occupies the nonwoven fabric surface, the better the polishing and wiping properties. In addition, the method of calculating the length of a molten solid and the ratio for which a molten solid occupies the nonwoven fabric surface was performed as follows. First, the surface of the non-woven fabric is magnified about 50 times with an electron microscope or the like, and arbitrarily photographed at 10 locations. The length of the molten solid was determined from the 10 positions taken. The ratio of the melted solids is 1 count if there are 10 consecutive locations where the melted solids are porous and spanning 1 mm or more, and how many 1 mm or more of the solids are present in 10 locations. The percentage was determined.

  The polishing nonwoven fabric of the present invention can have sufficient polishing power without using abrasives such as iron oxide, talc and aluminum oxide as in conventional polishing cloths, but these abrasives are used depending on the type of dirt. You can do it.

  In addition, when the nonwoven fabric for polishing of the present invention is used as a wet nonwoven fabric previously impregnated with a liquid containing a cleaning agent or an abrasive, cellulose-based fibers and a hydrophilic treatment are applied as fibers constituting the heat-resistant fiber layer. It is preferable to contain hydrophilic fibers such as synthetic fibers.

  Hereinafter, the laminated nonwoven fabric of the present invention will be described with reference to the drawings. FIG. 1 is a diagram showing an example of a fiber cross-sectional structure of a heat-fusible fiber that can be used in the present invention. Specifically, a cross-sectional structure of a concentric sheath-core type composite fiber having a low melting point component (1) as a sheath component and a high melting point component (2) as a core component is shown.

  2 (a) and 2 (b) are SEM photomicrographs of 50 times showing the surface structure of the laminated nonwoven fabric of the present invention. The melted solids in which the heat-fusible fibers are completely melted and gathered together spread on the surface of the nonwoven fabric to form a surface layer. Moreover, the molten solid is expanded in a porous shape to form a hole. The thermocompression bonding part exists in the hole part of FIG.2 (b).

  FIG. 3 is a schematic view of the laminated structure of the laminated nonwoven fabric of the present invention. In FIG. 3A, one of the surface layers (3) is the surface (3A), and the reinforcing fiber layer (5) is disposed between the inner surface (3B) side of the surface layer (3) and the heat resistant fiber layer (4). 3 shows a three-layer structure. FIG. 3B shows a five-layer structure in which the reinforcing fiber layer (5) is disposed between the inner surface (3B) side of the surface layer (3) and the heat-resistant fiber layer (4). In FIG. 3C, the surface layer (3) is one surface (3A), and the heat-resistant fiber layer (4) is disposed between the inner surface (3B) side of the surface layer (3) and the reinforcing fiber layer (5). 3 shows a three-layer structure.

  4 (a) and 4 (b) are 50-times SEM micrographs showing the cross-sectional structure of the laminated nonwoven fabric of the present invention. The nonwoven fabric has a surface layer formed on the surface of the reinforcing fiber layer by spreading molten solids in which the heat-fusible fibers are completely melted and gathered together. In addition, the molten solid material expands in a porous shape and rises in a concavo-convex shape, forming a convex portion and a hole portion. The thermocompression bonding part exists in the hole part of FIG.4 (b).

Hereinafter, the present invention will be described in detail by way of examples.
[Fiber preparation]
The following fibers were prepared:
(1) Heat-sealable fiber: Polybutene-1 resin having a melting point of 123 ° C. (trade name Toughmer BL7000, manufactured by Mitsui Chemicals, Inc.) and a core component having a melting point of 163 ° C., polypropylene resin (Nippon Polychem Co., Ltd.) A concentric sheath-core type composite fiber having a fiber cross-sectional area ratio (sheath: core) of 5: 5, a fineness of 4.2 dtex, and a fiber length of 51 mm.
(2) Heat-resistant fiber: Rayon fiber having a decomposition point of 200 ° C. or higher and a fiber length of 40 mm (manufactured by Daiwabo Rayon Co., Ltd., trade name Corona).

[Preparation of non-woven fabric]
The following nonwoven fabric was prepared as a reinforcing fiber layer.
(1) Spunbond nonwoven fabric A made of polyethylene terephthalate resin (E01015, manufactured by Asahi Kasei Corporation), basis weight 15 g / m ²
(2) Spunbond nonwoven fabric B made of polyethylene terephthalate resin (E01020, manufactured by Asahi Kasei Co., Ltd.), basis weight 20 g / m ²
(3) Spunbond nonwoven fabric C made of polyethylene terephthalate resin (Toyobo Co., Ltd., 6151A), basis weight 15 g / m ²

[Examples 1 to 4]
A card web for a surface layer having a basis weight of 30 g / m ^{2 and} comprising 100% by mass of heat-fusible fiber was prepared. On the other hand, a card web for a heat resistant fiber layer having a basis weight of 30 g / m ^{2 and} comprising 100 mass% of heat resistant fibers was prepared. A spunbond nonwoven fabric for reinforcing fiber layers shown in Table 1 was disposed between the two layers of card webs to form a laminate. Next, after the laminate was placed on the web conveying support, a columnar water flow with a water pressure of 3 MPa and 5 MPa was jetted onto the surface layer from a nozzle in which orifices having a pore diameter of 0.12 mm were arranged at intervals of 0.6 mm, and turned over to fiber. A water flow entanglement treatment was performed by jetting a columnar water flow of 5 MPa from the same nozzle on the layer surface. Subsequently, it dehydrated with the suction box and it dried at 100 degreeC and obtained the entangled nonwoven fabric.

  The entangled nonwoven fabric was heat-treated with hot air at a temperature shown in Table 1 for 10 seconds using an air-through heat treatment machine and naturally cooled to obtain the laminated nonwoven fabric of the present invention.

[Example 5]
A laminated nonwoven fabric of the present invention was obtained in the same manner as in Example 1 except that the surface layer card web was laminated on the other surface of the heat-resistant fiber layer of the laminate of Example 1.

[Comparative Example 1]
A card web having a basis weight of 30 g / m ² made of 100 mass% heat-fusible fiber was produced, and this was made into an entangled nonwoven fabric in the same manner as in Example 1. When heat treated under the same conditions as in Example 1, the entire nonwoven fabric contracted and could not be used as an abrasive cloth.

[Comparative Example 2]
The entangled nonwoven fabric of Example 1 was heat treated with hot air at a temperature of 140 ° C. for 10 seconds using an air-through heat treatment machine, and naturally cooled to obtain a nonwoven fabric. Since the obtained non-woven fabric had only melted the sheath component polybutene-1 resin in the heat-fusible fiber constituting the surface layer, and the heat-fusible fiber was not completely melted, Was not obtained.

[Comparative Example 3]
The entangled nonwoven fabric of Example 2 was heat treated with hot air at a temperature of 160 ° C. for 10 seconds using an air-through heat treatment machine, and naturally cooled to obtain a nonwoven fabric. Since the obtained non-woven fabric had only melted the sheath component polybutene-1 resin in the heat-fusible fiber constituting the surface layer, and the heat-fusible fiber was not completely melted, Was not obtained.

  Using the nonwoven fabrics of the above examples and comparative examples, a soil removal test was performed by the following method. The obtained results are shown in Table 1.

[Dirt removal test]
(1) Production of dirt Black oil-based ink A (trade name Magic Ink No. 500, manufactured by Teranishi Chemical Industry Co., Ltd.) and oil-based ink B (Zebra Co., Ltd.) (Product name: High McKee) was marked with a round mark with a diameter of about 1 cm to make it dirty.
(2) Test method On the stainless steel plate with the above-mentioned stain placed on a flat surface, a non-woven fabric cut into a square of 2 cm square was placed almost at the center on the stain mark attached with the above oil-based ink and soy sauce. The nonwoven fabric was reciprocated with a scraping width of 20 mm in one direction so that about 3 kg of pressure was applied to the nonwoven fabric with an index finger. The degree of dirt removal after each round-trip was visually confirmed and judged according to the following evaluation criteria. In addition, the nonwoven fabric was measured at the time of dryness and wetness (water was given 250 mass% with respect to the mass of the nonwoven fabric).
6 points: Dirt is completely removed after 5 reciprocations.
5 points: Dirt is completely removed after 10 reciprocations.
4 points: Dirt is completely removed after 20 reciprocations.
3 points: Dirt is completely removed after 30 reciprocations.
2 points: Dirt remains partially after 30 reciprocations.
1 point: About half of the dirt remains after 30 reciprocations.
0 point: Dirt is hardly removed even after 30 reciprocations.

[Bending hardness]
According to JIS-L-1913 6.7.2, it mounted and measured so that the surface layer containing a molten solid might become a non-contact surface of a testing machine. In addition, when both surfaces are the surface layers containing a molten solid, it measured on both surfaces and made the average value bending hardness.

  In the laminated nonwoven fabrics of Examples 1 to 5, the heat-fusible fibers constituting the surface layer were completely melted to form a melted solid material that spreads in a concavo-convex shape and gathered together, and the whole was ragged. It had hardness. When the nonwoven fabric surface of the obtained laminated nonwoven fabric was magnified 50 times with an electron microscope or the like and arbitrarily photographed at 10 locations, the length of the molten solid in at least one direction was 2 mm or more. Furthermore, the said melted solid substance existed in all 10 places, and occupied 100% of the nonwoven fabric surface.

  The non-woven fabrics for polishing of Examples 1 to 5 were excellent in polishing properties and wiping properties, and could remove oil-based ink stains. On the other hand, Comparative Example 1 is a non-woven fabric composed only of heat-fusible fibers and does not have a fiber layer. Therefore, it was not able to be handled as a non-woven fabric with rapid shrinkage during heat treatment. In the nonwoven fabric of Comparative Example 2, only the intersections of the heat-fusible fibers were fused, no molten solid was formed, and the stain could not be removed. In the nonwoven fabric of Comparative Example 3, the intersections of the heat-fusible fibers were fused and spread in the form of a water scrap, but no molten solid was formed and the stain could not be removed.

  The laminated nonwoven fabric of the present invention has a unique surface touch and is excellent in handling properties such as handling properties. It can be used for

It is a figure which shows an example of the fiber cross-section of a heat-fusible fiber which can be used for this invention. It is a 50 times SEM micrograph figure which shows the surface structure of the laminated nonwoven fabric of this invention. 1 is a schematic view of a laminated structure of a laminated nonwoven fabric of the present invention. It is a 50 times SEM micrograph figure which shows the cross-section of the laminated nonwoven fabric of this invention.

Explanation of symbols

1 Low melting point component 2 High melting point component 3 Surface layer 3A Surface 3B Inner surface 4 Heat resistant fiber layer 5 Reinforcing fiber layer

Claims (9)

A heat-resistant fiber comprising a surface layer forming a porous molten solid in which heat-fusible fibers are completely melted and gathered together, and a heat-resistant fiber having a melting point or decomposition point higher than the melting point of the molten solid a layer, on at least one surface of the heat-resistant fiber layer, Ri Na are arranged reinforcing fiber layer made of heat-bonding nonwoven fabric having at least a portion is crimped heat crimping portion of the fibers constituting,
A hydroentangled laminated nonwoven fabric in which the molten solid is present in a portion other than the thermocompression bonding portion . The water stream according to claim 1, wherein the heat-fusible fiber is a composite fiber composed of a low-melting-point component and a high-melting-point component, and the melting point of the high-melting-point component is lower than the melting point or decomposition point of the heat-resistant fiber. Interwoven laminated nonwoven fabric. The hydroentangled laminated nonwoven fabric according to claim 1 or 2, wherein the heat-fusible fiber contains a polybutene-1 resin. The heat-fusible fiber is a sheath-core type composite fiber having polybutene-1 resin as a sheath component and other polyolefin resin having a melting point higher than that of the polybutene-1 resin as a core component. The hydroentangled laminated nonwoven fabric according to any one of the above. The hydroentangled laminated nonwoven fabric according to any one of claims 1 to 4, wherein in the surface layer, heat-fusible fibers occupy 90 mass% or more. The hydroentangled laminated nonwoven fabric according to any one of claims 1 to 5, wherein the reinforcing fiber layer is disposed on the inner surface side of the surface layer. The hydroentangled laminated nonwoven fabric according to any one of claims 1 to 6, wherein the reinforcing fiber layer is a spunbonded nonwoven fabric containing heat-resistant fibers having a melting point or decomposition point higher than the melting point of the molten solid. A polishing nonwoven fabric comprising the hydroentangled laminated nonwoven fabric according to any one of claims 1 to 7 , wherein a thickness of at least one molten solid forming the surface layer is 0.15 mm or more. A polishing nonwoven fabric comprising the hydroentangled laminated nonwoven fabric according to any one of claims 1 to 8 , and comprising a molten solid having a length in one direction of 1 mm or more.