JP2008025048A - Base material for printing - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a base material for printing, which is composed of a nonwoven fabric having excellent water resistance and durability though having excellent flexibility and light weight, and enabling a clear image to be formed. <P>SOLUTION: The base material for the printing is composed of the nonwoven fabric having a two-layer structure of a fiber layer including ≥50 mass% flat fiber, and a fiber layer including <50 mass% flat fiber, which is obtained by interlacing the constituent fibers of both fiber layers by water flow to integrate both the fiber layers. A fiber having a fiber length of ≥15 mm in an amount of ≥30 mass% is included based on the whole constituent fiber. The constituent fiber is bound by an adhesive without fiber binding, and ink-receiving layers or toner-receiving layers are provided on both sides in the base material for the printing. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a printing substrate made of a nonwoven fabric that is excellent in flexibility and light weight, but also excellent in water resistance and durability, and particularly relates to a printing substrate that enables a clear image formation. The present invention relates to a printing substrate suitable for an inkjet printing substrate.

  Conventionally, non-woven fabric-based printing substrates have features such as better water resistance, softer texture, and more fabric-like texture than those based on paper. Taking advantage of this, it is used for applications such as calendars, candy packaging bags and handbags for offset printing, and for futon bags and kotatsu cover materials for gravure printing. However, as a printing substrate for announcements used outdoors, for example, for product advertisements, road guides, or banners for advertisements, it is excellent in flexibility and light weight while being water resistant and durable. Excellent base materials are required. Further, there is a demand for high quality materials with clearer printing characteristics.

  As such a printing substrate, for example, in Patent Document 1, an inkjet recording sheet obtained by coating or impregnating an ink receiving component on a support, the support is made of a nonwoven fabric, and the nonwoven fabric has a fiber diameter of 0. An ink jet recording sheet characterized by being composed of fibers having a denier of 1 to 0.8 denier is described. In addition, the nonwoven fabric as the support is a wet nonwoven fabric, or a stitch-bond method, a spunbond method, a melt-blown method, a dry-type nonwoven fabric by a thermal bond method, or a spunlace nonwoven fabric using a wet-type nonwoven fabric or a dry-type nonwoven fabric, A spunlace nonwoven fabric using a wet nonwoven fabric or a wet nonwoven fabric is used.

  Thus, in patent document 1, since the fiber used is a 0.1-0.5 denier extra fine fiber or a 0.5-0.8 denier fine fiber, there exists an effect that it is excellent in printability. However, only the wet nonwoven fabric or the melt blown nonwoven fabric can be applied to the ultrafine fiber. Among these, the wet nonwoven fabric has a very small fiber length, for example, 3 mm in the embodiment, and the strength of the resulting nonwoven fabric is extremely small. There was a problem of poor durability. In addition, the meltblown nonwoven fabric has a long fiber length, but the fibers are not stretched. Therefore, there is a problem that the strength of the resulting nonwoven fabric is extremely small and the durability is poor. On the other hand, for nonwoven fabrics such as a stitch bond method, a spun bond method, and a dry method using a card machine using a fine fiber having a fiber length of, for example, 15 mm or more, as a base material for inkjet printing, even if strength can be secured to some extent, Since the fiber is thick, the dispersibility of the fiber is inferior, the partial mass variation becomes large, and there is a problem that clear printing cannot be performed.

  In Patent Document 1, the spunlace nonwoven fabric is a post-processing for achieving a specific fragile air permeability to improve printing characteristics, or a specific fragile air flow by being laminated and integrated with a fabric by three-dimensional entanglement. The printing characteristics are improved by achieving the degree. Therefore, the spunlace nonwoven fabric does not solve the essential problems such as the above-described durability and mass variation when using ultrafine fibers or fine fibers. Moreover, in patent document 1, polyvinyl alcohol was used as the adhesive agent between fibers, and it was inferior also in water resistance.

JP 2000-296670 A

  The present invention solves the above-described problems, and is a printing substrate made of a nonwoven fabric that is excellent in flexibility and light weight, but also excellent in water resistance and durability, and enables clear image formation. It is an object to provide a substrate for printing.

  Means for solving the above problem comprises a fiber layer containing 50 mass% or more of flat fibers and a fiber layer containing less than 50 mass% of flat fibers, and the constituent fibers of both fiber layers are entangled by a water flow. And a substrate for printing comprising a non-woven fabric having a two-layer structure in which both fiber layers are integrated, and the fiber having a fiber length of 15 mm or more with respect to the entire constituent fibers is contained in an amount of 30% by mass or more. Is a substrate for printing characterized in that it is bonded by an adhesive regardless of fiber bonding, and an ink receiving layer or a toner receiving layer by the adhesive is provided on both sides.

  According to the present invention, there is provided a printing substrate made of a non-woven fabric having excellent flexibility and light weight, but also excellent in water resistance and durability, and capable of forming a clear printed image. It became possible to do.

  The substrate for printing of the present invention comprises a fiber layer (A) containing 50 mass% or more of flat fibers and a fiber layer (B) containing less than 50 mass% of flat fibers, and the structure of both fiber layers by water flow. A base material for printing made of a non-woven fabric having a two-layer structure in which fibers are entangled and both fiber layers are integrated (hereinafter sometimes referred to as a non-woven fabric base fabric). Is contained in an amount of 30% by mass or more.

  A flat fiber has a major axis and a minor axis in a fiber cross section. When the major axis length is a and the minor axis length is b, the flatness a / b is a fiber having a value of 2 or more. Yes, the value of a / b is preferably 3 or more, more preferably 5 or more. As such a cross-sectional shape, for example, it has an elliptical shape, a rectangular shape, a triangular shape, a trapezoidal shape, a dogbone shape, etc. is there. Moreover, since the fiber layer which consists of flat fibers becomes thin and becomes a dense layer, there exists an advantage that it is excellent in a softness | flexibility and flexibility. When the cross-sectional shape is triangular or fan-shaped, the length of the straight line that can be taken the longest in the cross-section is the long axis a, the length of the straight line that is orthogonal to the long-axis diameter and that can be taken the longest The short axis b can be used. The flatness a / b can be obtained by averaging, for example, 100 or more scanning electron microscope images.

  Examples of such flat fibers include polyester fibers such as polyethylene terephthalate and polybutylene terephthalate, polyamide fibers such as nylon 6 and nylon 66, polyolefin fibers such as polypropylene and polyethylene, and acrylic fibers such as polyacrylonitrile. In addition, not only synthetic fibers such as polyvinyl alcohol fibers but also semi-synthetic fibers such as rayon or natural fibers such as wood pulp fibers can be mentioned.

  Of these, natural fibers such as pulp fibers are flat fibers without any particular processing, but flat fibers made of synthetic fibers and flat fibers made of semi-synthetic fibers are spun from a fiber-forming resin from a modified cross-section spinning nozzle. Can be obtained by: Moreover, it is also possible to be a flat fiber made of ultrafine fibers generated by dividing from splittable fibers.

  Such a splittable fiber is a fiber composed of a splittable composite fiber in which two or more kinds of fiber-forming resin components are combined, and the action of a water flow ejected from a nozzle or when dispersed in water. A fiber that can be divided by the action of water flow or extraction with a solvent. The cross-sectional shape of the splittable fiber is not particularly limited, and for example, there are forms shown in (a) to (d) of FIG. Among these cross-sectional shapes, the shape having a large flatness shown in (b) and (d) is preferable because the features of the flat fibers appear remarkably. Moreover, since the surface state becomes denser due to the ultrafine flat fibers, there is an advantage that the printability is more excellent. Further, the number of divisions of the splittable fiber is not limited, and may be two or more, for example, about 6 to 20 divisions are preferable.

  In the present invention, the flat fiber is required to be contained in the fiber layer (A) by 50% by mass or more, preferably 70% or more, and more preferably 90% or more. By including 50% by mass or more of flat fibers, it becomes possible to form a clear printed image on the printing substrate. On the other hand, if it is less than 50% by mass, there is a problem that a clear printed image cannot be formed.

  In the present invention, the flat fiber is required to be contained in the fiber layer (B) in an amount of less than 50% by mass, preferably 30% or less, more preferably 10% or less. By containing less than 50% by mass of flat fibers, the printing substrate is excellent in strength and water resistance and durability. On the other hand, when the content is 50% by mass or more, there is a problem that the strength of the printing substrate is inferior or the water resistance and durability are inferior.

  Moreover, in this invention, it is required that the fiber whose fiber length is 15 mm or more is contained 20 mass% or more with respect to the whole constituent fiber of the fiber layer which combined the fiber layer (A) and the fiber layer (B). 30% by mass or more is more preferable, and 40% by mass or more is more preferable. By containing 30% by mass or more, the effect of entanglement due to the water flow is remarkably exhibited, and the printing substrate is excellent in strength, flexibility, and water resistance and durability. On the other hand, when the amount is less than 30% by mass, there is a problem that the effect of entanglement by the water flow is reduced, and the printing substrate is inferior in strength or inferior in water resistance and durability.

  As the fiber having a fiber length of 15 mm or more, for example, a fiber called a normal staple fiber having a crimp length of 5 to 30 / inch and having a fiber length of 15 to 100 mm used in a dry nonwoven fabric using a card machine or an air array device is applied. can do. Examples of the fibers having a fiber length of less than 15 mm include cut fibers and wood pulp fibers having a fiber length of 3 to 15 mm used for wet process nonwoven fabric and paper making.

  In the present invention, a fiber having a fiber length of 15 mm or more can also serve as the flat fiber. However, as a more preferable form, the fiber layer (A) containing 50 mass% or more of the flat fiber mainly has a fiber length of 15 mm. The fiber layer (B) including less than 50% by mass of flat fibers is mainly composed of fibers having a fiber length of 15 mm or more. Here, “mainly” means containing 50% by mass or more, preferably 70% or more, and more preferably 90% or more. With such a form, it is possible to form a particularly clear printed image on one side of the printing substrate, and on the other side it is inferior in sharpness, but the entire printing material has strength, water resistance and durability. By providing the effect of imparting the properties and sharing the roles in each layer, the overall flexibility is excellent, the water resistance and the durability are excellent, and a clear image can be formed.

  Moreover, in this invention, it is possible to be a fiber layer which mixed the flat fiber and the fiber which has another characteristic for the purpose of ensuring durability. The fibers other than the flat fibers are not particularly limited as long as the desired flexibility, light weight, water resistance, durability, printability, etc. can be ensured and the cross-sectional shape is not flat. For example, polyethylene terephthalate, polybutylene Not only polyester fibers such as terephthalate, polyamide fibers such as nylon 6 and nylon 66, polyolefin fibers such as polypropylene and polyethylene, acrylic fibers such as polyacrylonitrile, and synthetic fibers such as polyvinyl alcohol fibers, Mention may be made of synthetic fibers or natural fibers such as cotton and cellulosic fibers.

  In the present invention, the constituent fibers of the fiber layer (A) and the fiber layer (B) are bonded by an adhesive regardless of fiber bonding. For this reason, although it is possible for the constituent fibers to contain heat-adhesive fibers, it is necessary that the fibers are not bonded by heating. Therefore, it is desirable that the constituent fibers do not contain heat-adhesive fibers. As such a heat-bondable fiber, (1) an embodiment composed of only one fusion component, (2) an embodiment in which one or more resin components are coated with a fusion component (core-sheath type, etc.), or one There is a mode (side-by-side type or the like) in which the above resin component and fusion component are arranged next to each other. The fiber having a low melting point component is a resin in which the melting point of the resin component having the lowest melting point among the resin components constituting the thermal adhesive fiber is the lowest melting point among the resin components constituting the other fibers. A fiber that is lower than the melting point of the component, for example, a fiber that is 20 ° C. to 40 ° C. or more lower.

  In this invention, since the component fiber is not couple | bonded by fiber adhesion, there exists an advantage that it is excellent in the softness | flexibility of a printing base material. On the other hand, when the constituent fibers are bonded by fiber bonding, there is a problem that the printing substrate is inferior in flexibility. Further, for example, after the constituent fibers of the fiber layer (B) are bonded by fiber bonding and the degree of freedom of the constituent fibers is reduced, the fibers of the fiber layer (A) and the fibers of the fiber layer (B) are entangled. The entanglement of the fibers of the fiber layer (A) and the fibers of the fiber layer (B) is insufficient, the integration of the fiber layer (A) and the fiber layer (B) is inferior and bulky, so that both layers are simply There was a problem that it was in a state of being pasted together and was inferior in flexibility.

  Next, the aspect of the fiber layer will be described. As the fiber layer, a fiber web or paper obtained by a conventionally known method for producing nonwoven fabric or paper can be applied. Examples of the fiber web include a fiber web formed by a wet method, and include fibers using a paper machine of a horizontal long net method, an inclined wire type short net method, a circular net method, or a long net / circular net combination method. A method of rolling up the fiber sheet from the slurry can be employed. Further, for example, there is a fiber web formed by using a staple fiber with a card machine or an air array device. Further, there is a fiber web made of long fibers in which thermoplastic synthetic fibers are spun from a nozzle and laminated by, for example, a spunbond method.

  In the present invention, these fiber webs and papers can be used in combination. For example, as a preferred embodiment, a fiber web or paper by a wet method is used for the fiber layer (A) and a dry method is used for the fiber layer (B). There is an embodiment using a fiber web. Further, for example, there is an embodiment in which a fiber web by a dry method is used for the fiber layer (A) and the fiber layer (B). Specifically, a laminate in which fiber webs and papers are laminated in this way is placed on a hole support and the like, and then a water flow sprayed from a nozzle head containing high-pressure water hits this laminate. By the action of this water flow, the fibers in the fiber web are entangled and the fibers in the fiber layer (A) and the fibers in the fiber layer (B) are also entangled, and at the same time both the fiber layer (A) and the fiber layer (B). A nonwoven fabric base fabric having a two-layer structure in which fiber layers are integrated can be mentioned. In this two-layer nonwoven fabric, the fibers of the fiber layer (A) and the fibers of the fiber layer (B) enter the fiber layer on the other side, so there is no clear boundary between the fiber layers. The material has a density gradient. Therefore, it is no longer a state where both layers are simply pasted together, and as a result, both tension and flexibility can be achieved, and the printing substrate is excellent in flexibility.

  In addition, in order to entangle the fibers in the fiber web by the action of a water flow sprayed from a nozzle head containing high-pressure water, it is possible to use a method for producing a nonwoven fabric by a normal water flow entanglement. A number of nozzle holes are placed on the upper end of the fiber web by placing the web on an aperture support made of a belt conveyor and moving the aperture support, and the nozzle head containing high-pressure water is installed. There is a method in which a columnar flow is ejected through a nozzle plate arranged in a straight line to cause a water flow to act on the fiber web. The diameter of the nozzle holes used in this method is preferably 0.1 to 0.3 mm, the interval between the nozzle holes is preferably 0.5 to 2 mm, and a plurality of nozzle heads are preferably used. Further, the water pressure in the nozzle head is preferably 0.2 to 2 MPa, and when dividing the splittable fiber, 0.5 to 2 MPa is preferable although it depends on the degree of splitability.

  Specific examples of using a wet fiber web or paper for the fiber layer (A) and a dry fiber fiber for the fiber layer (B) include a wood pulp fiber sheet (paper) for the fiber layer (A). ), And a fiber web is formed from staple fibers made of ordinary synthetic fibers having a non-flat cross section using a card machine or an air array device, and then the wood pulp fiber sheet is placed on the fiber web. Then, there is an embodiment in which a non-woven fabric base fabric having a two-layer structure in which the constituent fibers of both fiber layers are entangled by the water flow and the both fiber layers are integrated is formed. According to this example, it is possible to form a printing substrate which is excellent in flexibility, water resistance and durability while being capable of forming a clear printed image like paper on one side. Further, since the fiber raw material is a wood pulp fiber sheet, there are advantages that the raw material cost is low and the biodegradability is excellent.

  Another example in which a fiber web or paper by a wet method is used for the fiber layer (A) and a fiber web by a dry method is used for the fiber layer (B) has a cross-sectional form shown in FIG. A composite fiber (fiber diameter 18 μm, fiber length 5 mm, resin component 1 is polyethylene terephthalate resin, resin component 2 is 6 nylon resin) is dispersed in water containing a dispersant to form a slurry. At this time, the composite fiber is disaggregated into a maximum of 11 portions, and each disaggregated fiber (average fiber diameter 5.5 μm) is a composite fiber having a flat cross-sectional shape. Next, the slurry is made into paper and then dried to prepare a fiber web by a wet method. Next, after forming a fiber web from staple fibers made of ordinary synthetic fibers having a non-flat cross section using a card machine or an air lay apparatus, the fiber web is placed on the fiber web, and both are formed by water flow. There exists the aspect which formed the nonwoven fabric base fabric of the two-layer structure by which the fiber of a fiber layer was entangled and both fiber layers were integrated. According to this example, since a large number of flat fibers are arranged on one side, a clear printed image can be formed, and at the same time, it can be a substrate for printing having excellent flexibility and excellent water resistance and durability.

  As a specific example using the fiber web by the dry method for both the fiber layer (A) and the fiber layer (B), the fiber layer (A) and the fiber layer (B) are composed of composite fibers having cross-sectional shapes shown in FIGS. A fiber web is formed by a card machine or an air lay apparatus using staple fibers that can be divided by the action of water flow. Next, after forming a fiber web from staple fibers made of ordinary synthetic fibers whose cross-section is not flat using a card machine or an air array device, the former fiber web is placed on the latter fiber web, There is an aspect in which a composite fiber is divided by water flow to generate ultra-thin flat fibers, and the non-woven base fabric having a two-layer structure in which the constituent fibers of both fiber layers are entangled and the two fiber layers are integrated is formed. . According to this example, since a large number of flat fibers are arranged on one side, it is possible to form a clear printed image, and since it has ultrafine fibers, it is more flexible, and because the ultrafine fibers are highly entangled, it is water resistant and durable. In addition, it can be an excellent printing substrate.

  In the specific example described above, a fiber web by a dry method is used as the fiber layer (B), but a long fiber web by a spunbond method can also be used. In addition, when combining fiber webs having different production methods, it is preferable to form one or both of the fiber webs into a sheet. For this reason, a fiber web composed of fibers made of thermoplastic resin is passed between a heating roll having irregularities and a flat heating roll, and the self-bonding part or the fiber bonding part is peeled off by the action of water flow later. Furthermore, it is also possible to prepare a fiber sheet that is partially temporarily bonded. In the case where the constituent fibers are bonded to the fiber to such an extent that the self-bonding portion or the fiber bonding portion is not peeled off later by the action of the water flow, it deviates from the object of the present invention. That is, when the constituent fibers are bonded by fiber bonding, there is a problem that the printing substrate is inferior in flexibility. Further, for example, after the constituent fibers of the fiber layer (B) are bonded by fiber bonding and the degree of freedom of the constituent fibers is reduced, the fibers of the fiber layer (A) and the fibers of the fiber layer (B) are entangled. The entanglement of the fibers of the fiber layer (A) and the fibers of the fiber layer (B) is insufficient, the integration of the fiber layer (A) and the fiber layer (B) is inferior and bulky, so that both layers are simply There is a problem that it is in a state of being pasted and inferior in flexibility.

  The above-mentioned splittable fiber is a fiber composed of a splittable composite fiber in which two or more types of fiber-forming resin components are combined, and as long as the splittable fiber can be split by the action of a water flow or the like, The cross-sectional shape is not particularly limited, and for example, there is a form shown in FIGS. The number of divisions of the splittable fiber is not limited, and may be two or more. For example, about 6 to 20 divisions are preferable.

  The type of fiber-forming resin that constitutes the splittable fiber is not particularly limited. For example, polyamide resin (for example, 6 nylon, 66 nylon, etc.), polyester resin (for example, polyethylene terephthalate, polybutylene). Terephthalate, etc.), polyolefin resins (for example, polyethylene, polypropylene, etc.), polyvinylidene chloride resins, and the like. Among these, it is preferable to select at least a polyester-based resin as one component because high strength and excellent durability and printability can be imparted.

  The thickness of the splittable fiber is not particularly limited as long as spinning conditions and splittability are considered, and the fiber diameter is preferably 10 to 100 μm, and more preferably 20 to 50 μm. Moreover, 0.1-10 micrometers is preferable and the fiber diameter after a division | segmentation has more preferable 0.1-5 micrometers. The fiber diameter before or after division can be the diameter of a circle having the same area as the cross section of the fiber.

The surface density of the nonwoven fabric base fabric is preferably from 20 to 200 g / ^{m 2,} more preferably 30 to 150 g / ^{m 2,} more preferably 50 to 120 / ^{m 2.} If it is less than 20 g / m ² , the fiber density is low, so that clear printing may not be achieved, and if it exceeds 200 g / m ² , it may be too heavy or expensive. Moreover, the ratio of the surface density of the fiber layer (A) and the surface density of the fiber layer (B) is not particularly limited, but is preferably 3/7 to 7/3.

  Thus, since the obtained nonwoven fabric base fabric has a fiber layer containing 50% by mass or more of flat fibers, a dense layer is formed and the concealment name is high although the surface density is low. There is an advantage. In addition, since the entanglement is performed with flat fibers, a dense fiber layer is formed. Further, the flat fibers have a smooth surface and less lint is generated. As a result, a clear printed image can be formed. Further, because of the smoothness, the paper feeding property is also excellent, so that high-speed printing is possible. In addition, since fibers having a fiber length of 15 mm or more are entangled, they have a soft texture and are excellent in strength, tear strength, water resistance, and can be used outdoors. Also, nozzle streaks due to the action of water flow may be preferred as a unique design. Thus, the obtained non-woven fabric base fabric is excellent in flexibility and light weight, but also becomes a printing substrate excellent in water resistance and durability, and enables a clear printed image formation. There is an effect.

  In the substrate for printing of the present invention, the constituent fibers of the nonwoven fabric base fabric are bonded by an adhesive, not by fiber bonding, and an ink receiving layer or a toner receiving layer by the adhesive is provided on both sides. That is, the adhesive has both the function of binding the constituent fibers of the nonwoven fabric base and the function of forming the ink receiving layer or the toner receiving layer. Here, the ink receiving layer or the toner receiving layer is a layer that absorbs and fixes printing ink such as inkjet ink, and more preferably a layer that has a function of imparting image bleeding and water resistance. It is.

  As the material constituting the ink receiving layer, any conventionally known material can be used. Specifically, albumin, gelatin, casein, starch, cationic starch, gum arabic, polyvinyl imidazole, agar, hydrophilic natural materials such as sodium alginate, dextrin, viscose, methylcellulose, ethylcellulose, carboxymethylcellulose, hydroxyethylcellulose, cation modification Hydroxyethyl cellulose, polyvinyl alcohol, cation-modified polyvinyl alcohol, acetal-modified polyvinyl alcohol (polyvinyl acetal), polyethylene glycol, polypropylene glycol, polyacrylic acid, water-soluble alkyd, polyvinyl ether, polyvinyl pyrrolidone, quaternized polyvinyl pyrrolidone, polyamide, polyacrylamide , Poly (N-vinyl-3methylpyrrolidone), polymalein Examples include water-soluble or hydrophilic synthetic resins such as copolymers, polyethyleneimine, polyethylene oxide, polyvinylimidazole, polyallylamine, polyallylamine hydrochloride, melamine resin, polyurethane, and polyester. If desired, at least one of these materials is used. It is done.

  The material constituting the ink receiving layer is a biodegradable resin such as poly (α-hydroxy acid) (for example, polyglycolic acid, poly-L-lactic acid, etc.), poly (β-hydroxyalkanoate). ) (For example, poly (β-hydroxybutyric acid), β-hydroxybutyric acid-βhydroxyvaleric acid copolymer, etc.), poly (ω-hydroxyalkanoate) (for example, poly-β-propiolactone, poly-ε- Caprolactone, etc.), polyalkylene dicarboxylates (eg, polyethylene succinate, polybutylene succinate, butylene succinate-butylene adipate copolymer, etc.), and at least one of these materials can be used if desired. It is.

  Further, in particular, for the purpose of improving ink jet recording suitability, for example, beading resistance, blocking resistance, etc., the storage stability of the obtained ink jet recorded material, for example, image bleeding and water resistance in a high humidity environment, etc. For the purpose of improvement, in addition to the above materials, water-soluble low-molecular organic compounds, cationic compounds, and water-insoluble organic compounds can be used as appropriate.

  Examples of water-soluble low molecular weight organic compounds used at this time include polyvalent ethylene glycol, polyethylene glycol, poly (ethylene glycol-propylene glycol) copolymer, D-sorbitol, and sucrose having a molecular weight of 5,000 or less. Alcohol etc. are mentioned.

  Further, as the cationic compound, primary, secondary and tertiary amine salt type compounds, for example, laurylamine, palmamine, stearylamine, rosinamine and other hydrochlorides and acetates; quaternary ammonium salt type compounds, For example, lauryltrimethylammonium chloride, lauryldimethylbenzylammonium chloride, benzyltributylammonium chloride, benzalkonium chloride and the like; pyridinium salt type compounds such as cetylpyridinium chloride and the like; imidazoline type cationic compounds such as 2-heptadecenyl-hydroxyethyl Examples include imidazoline and the like; ethylene oxide adducts of higher alkylamines such as dihydroxyethyl stearylamine.

  Furthermore, water-insoluble organic compounds include acrylic resins typified by polymethyl methacrylate, polyamides typified by 6,6 nylon, polyvinyl acetals typified by butyral resins, polyethylene, polypropylene, polystyrene resins, polychlorinated resins. Examples thereof include vinyl, phenol resin, epoxy resin, polyester, polyurethane, diacetate compound, D-sorbitol / aromatic aldehyde condensate and the like.

Further, in order to improve physical properties as an ink jet recording medium, such as blocking resistance, conventionally known organic and / or inorganic fine particles (powder, emulsion, etc.) are added in an amount of 0.01 to 30 g in the ink receiving layer. / M ² , preferably about 1 to ²⁰ g / m ² can be added. Examples of the organic and / or inorganic fine particles include light calcium carbonate, heavy calcium carbonate, kaolin, talc, calcium sulfate, barium sulfate, titanium dioxide, zinc oxide, zinc sulfide, zinc carbonate, satin white, aluminum silicate, and diatomaceous earth. , Calcium silicate, magnesium silicate, synthetic amorphous silica, colloidal silica, colloidal alumina, pseudoboehmite, aluminum hydroxide, alumina, lithopone, zeolite, hydrous halloysite, magnesium carbonate, magnesium hydroxide, white inorganic pigment, styrenic plastic Examples thereof include organic pigments such as pigment, acrylic plastic pigment, polyethylene, microcapsule, urea resin, and melamine resin. Among these fine particles, the white pigment contained as a main component in the ink receiving layer is preferably a porous inorganic pigment, and examples thereof include porous synthetic amorphous silica, porous magnesium carbonate, and porous alumina. Porous synthetic amorphous silica having a large pore volume is preferred.

  In addition to the fine particles, conventionally known additives such as dispersants, lubricants, antifoaming agents, and other surfactants, oils, pH adjusters, fluorescent dyes, preservatives, and the like are added to the ink receiving layer. It can be used within a range that does not deteriorate the performance of the substrate for ink jet printing in the present invention.

  As a method for forming the ink receiving layer on the nonwoven fabric base fabric, there is a method in which a coating liquid made of the above material is impregnated with, for example, a padder. In addition, there are methods of forming by coating with various blade coaters, roll coaters, air knife coaters, bar coaters, rod coaters, gate roll coaters, curtain coaters, short dwell coaters, gravure coaters, flexographic gravure coaters, size presses and the like. Among these methods, the method of forming by padding impregnation is an advantageous method in that both surfaces of the non-woven fabric can be printed with a single treatment.

  As a specific form in which the nonwoven fabric base has an ink receiving layer, the form differs depending on the method for forming the ink receiving layer described above, and the form obtained mainly by padding impregnation and the like mainly by coating. It can be divided into two types of obtained forms.

  As a form obtained by padding impregnation, etc., the ink receiving layer is formed relatively uniformly over the whole thickness direction of the nonwoven fabric, and the material for forming the ink receiving layer between the fibers is densely packed. And a form in which the material for forming the ink receiving layer is interspersed between the fibers. Specifically, the mass of the material forming the ink receiving layer is preferably 1% or more, and more preferably 2% or more with respect to the total mass of the constituent fibers. Further, it is preferably less than 30%, more preferably less than 20%, and even more preferably less than 10%. When it is less than 30%, the printed substrate is more excellent in flexibility.

  In addition, as a form in which the ink receiving layer is formed relatively uniformly in the entire thickness direction of the nonwoven fabric base fabric, when the fiber structure is very coarse and the pore diameter is large, it can be obtained not only by padding impregnation but also by coating. It is.

  As the form in which the nonwoven fabric base fabric has an ink receiving layer by coating or the like, the above-mentioned various blade coaters, roll coaters, air knife coaters, bar coaters, rod coaters, gate rolls are provided on at least one surface of the nonwoven fabric base fabric. There is a form in which the ink receiving layer is applied by a method of applying by a coater, curtain coater, short dwell coater, gravure coater, flexographic gravure coater, size press or the like. The coating amount of the ink receiving layer can be determined in consideration of the surface state of the nonwoven fabric base and the permeability into the porous fiber structure. The form having the ink receiving layer by this coating or the like is characterized in that the density of the ink receiving layer is increased in the vicinity of the surface of the substrate for ink jet printing. When the ink receiving layer is provided on the surface portion substantially free of fibers (for example, 10% or less by mass ratio), the thickness of the ink receiving layer is preferably 1 to 50 μm, 30 μm is more preferable.

Surface density of the printing base material is preferably from 25~230g / ^{m 2,} more preferably 35~180g / ^{m 2,} more preferably 55~150g / ^{m 2.} If it is less than 25 g / m ² , the surface density of the nonwoven fabric base fabric is small, so that clear printing may not be achieved, and if it exceeds 230 g / m ² , it may be too heavy or expensive. Moreover, it is preferable that the thickness of the said base material for inkjet printing is 0.1-1.2 mm, 0.13-0.8 mm is more preferable, 0.15-0.7 mm is further more preferable. The thickness is the thickness specified in the 6.1.2A method of JIS L1913-1998. However, the load was 2.0 kPa.

In addition, the tensile strength of the printing substrate is preferably 80 N / 50 mm width or more when converted to an area density of 100 g / m ² when expressed as an average value in the vertical direction and the horizontal direction, and 90 N / 50 mm. More preferably, the width is more preferably 100 N / 50 mm width or more. Further, the tear strength of the inkjet printing substrate is preferably 4N or more, more preferably 5N or more when converted to an average surface density of 100 g / m ² in terms of the average value in the vertical and horizontal directions. . In addition, let the tensile strength be the tensile strength prescribed | regulated to 6.3 of JISL1913-1998. The tear strength is the tear strength specified in 6.4.3 (single tongue method) of JIS L1913-1998.

  Further, the bending resistance (cantilever method) of the printing substrate is preferably 250 mm or less, and more preferably 200 mm or less, when expressed by an average value in the vertical direction and the horizontal direction. Moreover, in the field | area where a softness | flexibility is requested | required especially, it is preferable that it is 150 mm or less, and 120 mm or less is more preferable. The bending resistance is the bending resistance defined by the 8.19.1A method (45 ° cantilever method) of JIS L1096-1999.

Further, air permeability of the printing substrate ^is preferably 2~100cm ^{3 /} cm 2 ^{/ sec,} more preferably ^{4~50cm 3 / cm 2 / sec,} 5~30cm 3 / cm 2 / sec is Further preferred. In addition, let air permeability be the air permeability prescribed | regulated to the 8.27.1A method (fragile type method) of JISL1096-1999.

  As described above, according to the present invention, it is a printing substrate made of a nonwoven fabric that is excellent in flexibility and light weight but also excellent in water resistance and durability, and enables a clear printed image formation. It has become possible to provide a substrate for inkjet printing.

  Examples of the present invention will be described below, but these are only suitable examples for facilitating understanding of the invention, and the present invention is not limited to the contents of these examples.

(Printability-Sharpness evaluation method)
A full color image was inkjet printed using a pigment ink or a dye ink, and bleeding and image sharpness were evaluated by visual observation. As the evaluation criteria, “◯” was obtained when there was no blur and the image was clear, “Δ” when the image was slightly blurred but there was no problem in practical use, and “X” when the image was not noticeably blurred.
(Tensile strength and tensile elongation)
It tested by the method prescribed | regulated to 6.3 of JISL1913-1998.
(Tear strength)
It tested by the method prescribed | regulated to 6.4.3 (single tongue method) of JISL1913-1998.
(Flexibility)
It tested by the method prescribed | regulated to the 8.19.1A method (45 degree cantilever method) of JISL1096-1999.
(Air permeability)
It tested by the method prescribed | regulated to the 8.27.1A method (fragile type method) of JISL1096-1999.
(Dye fastness to friction)
It tested by the method prescribed | regulated to JISL0849-2004. Using a Gakushin type friction tester, mount the dried test piece on the test stand, apply a load of 2N to the friction element, and after 100 reciprocations, observe the surface condition of the test piece, The case where there was no or very little was judged as good (◯), the case where there was little change in color was judged as slightly good (Δ), and the case where the color became light was judged as bad (x).
(Abrasion resistance against friction)
It tested by the method prescribed | regulated to JISL0849-2004. Using a Gakushin type friction tester, mount the dried test piece on the test stand, apply a load of 2N to the friction element, and after 100 reciprocations, observe the surface condition of the test piece, change the fiber structure and fluff The case where there was no or very little was determined as good (◯), the case where there was little change in fiber structure and fluffing was judged as slightly good (Δ), and the case where the fiber structure collapsed or very fluffy was judged as poor (X).

(Example 1)
A wood pulp fiber sheet (paper) having an areal density of 40 g / m ² was prepared for the fiber layer (A). Next, for the fiber layer (B), 1.5 dtex polyester staple fibers (fiber length: 22 mm) are accumulated on the aperture support with an air array device, and a fiber web having an areal density of 27 g / m ² is obtained. Obtained. Next, the wood pulp fiber sheet is placed on the fiber web, and a columnar flow is ejected from a nozzle head containing high-pressure water to cause the water flow to act on the fiber web. Dried. As a result, it consists of a fiber layer containing 50 mass% or more of flat fibers (wood pulp fibers) and a fiber layer containing less than 50 mass% of flat fibers (wood pulp fibers), and the constituent fibers of both fiber layers are formed by water flow. A nonwoven fabric base fabric having a two-layer structure with an area density of 67 g / m ² in which both fiber layers were integrated with each other was obtained. Moreover, the nonwoven fabric base fabric contained 40% by mass of fibers having a fiber length of 22 mm with respect to the entire constituent fibers.
In addition, for forming an ink receiving layer, a dispersion was prepared by dispersing 8% by mass of an aqueous solution (liquid concentration 35%) obtained by adding a cationic fixing agent to an acrylic resin emulsion in 92% by mass of water. Next, the nonwoven fabric base was immersed in this dispersion, and then passed between a pair of rubber rolls so as to be impregnated with padder, so that a certain amount of the dispersion was included in the nonwoven fabric. Next, the impregnated nonwoven fabric was dried with a dryer set at a temperature of 150 ° C. to form an ink-receiving layer on the nonwoven fabric, thereby obtaining a printing substrate suitable for inkjet printing.
The ink receiving layer was formed almost uniformly in the thickness direction on the printing substrate, and printing was possible on both surfaces. The surface density of the printing substrate is a 68.4 g / ^{m 2,} the adhesive forming the ink receiving layer is 1.4 g / ^{m 2,} it had a thickness of 0.28 mm. Further, the tensile strength was 128 N / 50 mm width in the longitudinal and transverse directions, and the tensile elongation at break was 31% in the longitudinal and transverse directions. Moreover, the average value of the longitudinal direction and the horizontal direction was 5.8 N for the tear strength, and the average value for the bending resistance was 91 mm in the vertical direction and the horizontal direction. The air permeability was 9.8 cm ³ / cm ² / sec. In addition, Table 1 shows the results of the evaluation of the sharpness of printing, the dyeing fastness test and the abrasion resistance test.

(Example 2)
In the same manner as in Example 1, a nonwoven fabric base with an area density of 67 g / m ² was obtained.
In addition, for forming an ink receiving layer, 50 mass% of an aqueous solution (liquid concentration 21%) in which silica particles and polyvinyl alcohol are added to an acrylic resin emulsion, and a cationic fixing agent (polyallylamine hydrochloride aqueous solution, liquid concentration 35%) 2 A dispersion liquid in which mass% was dispersed in 48 mass% of water was prepared. Next, the nonwoven fabric base was immersed in this dispersion, and then passed between a pair of rubber rolls so as to be impregnated with padder, so that a certain amount of the dispersion was included in the nonwoven fabric. Next, the impregnated nonwoven fabric was dried with a dryer set at a temperature of 150 ° C. to form an ink-receiving layer on the nonwoven fabric, thereby obtaining a printing substrate suitable for inkjet printing.
The ink receiving layer was formed almost uniformly in the thickness direction on this printing substrate, and printing was possible on both surfaces. Further, the surface density of this printing substrate was 70 g / m ² , the adhesive forming the ink receiving layer was 3.0 g / m ² , and the thickness was 0.29 mm. Further, the tensile strength was 142 N / 50 mm width in the longitudinal and lateral directions, and the tensile elongation at break was 29% in the longitudinal and lateral directions. The tear strength was 5.4 N in the average value in the vertical and horizontal directions, and the bending resistance was 115 mm in average in the vertical and horizontal directions. The air permeability was 6.8 cm ³ / cm ² / sec. In addition, Table 1 shows the results of the evaluation of the sharpness of printing, the dyeing fastness test and the abrasion resistance test.

(Example 3)
In the same manner as in Example 1, a nonwoven fabric base with an area density of 67 g / m ² was obtained.
Next, an ink receiving layer was formed on the nonwoven fabric base fabric in the same manner as in Example 2 to obtain a printing substrate suitable for inkjet printing.
The ink receiving layer was formed almost uniformly in the thickness direction on the printing substrate, and printing was possible on both surfaces. Further, the surface density of this printing substrate was 73.3 g / m ² , the adhesive forming the ink receiving layer was 6.3 g / m ² , and the thickness was 0.3 mm. Further, the average value of the tensile strength in the longitudinal direction and the transverse direction was 154 N / 50 mm width, and the tensile elongation at break was 24% in the average value in the longitudinal direction and the transverse direction. Moreover, the average value of tear strength in the longitudinal direction and the transverse direction was 4.7 N, and the bending resistance was 130 mm in average value in the longitudinal and transverse directions. The air permeability was 6.3 cm ³ / cm ² / sec. In addition, Table 1 shows the results of the evaluation of the sharpness of printing, the dyeing fastness test and the abrasion resistance test.

Example 4
In the same manner as in Example 1, a nonwoven fabric base with an area density of 67 g / m ² was obtained.
Next, an ink receiving layer was formed on the nonwoven fabric base fabric in the same manner as in Example 2 to obtain a printing substrate suitable for inkjet printing.
The ink receiving layer was formed almost uniformly in the thickness direction on the printing substrate, and printing was possible on both surfaces. Further, the surface density of this printing substrate was 77 g / m ² , the adhesive forming the ink receiving layer was 10.0 g / m ² , and the thickness was 0.31 mm. Further, the tensile strength was 164 N / 50 mm width in the longitudinal and transverse directions, and the tensile elongation at break was 20% in the longitudinal and transverse directions. In addition, the average value of tear strength in the vertical direction and the horizontal direction was 4.1 N, and the bending resistance was 140 mm in average value in the vertical and horizontal directions. The air permeability was 6.0 cm ³ / cm ² / sec. In addition, Table 1 shows the results of the evaluation of the sharpness of printing, the dyeing fastness test and the abrasion resistance test.

(Comparative Example 1)
As the ultrafine fiber, 3.3 dtex composite fiber (fiber diameter 18 μm, fiber length 5 mm, resin component 1 is polyethylene terephthalate resin, resin component 2 is 6 nylon resin) having the cross-sectional form shown in FIG. A 1.7 dtex polyethylene terephthalate fiber (fiber diameter: 13 μm, fiber length: 10 mm) as non-adhesive fiber was dispersed in water containing a dispersant to form a slurry. At this time, the composite fiber was disaggregated into a maximum of 11 portions, and each disaggregated fiber (average fiber diameter 5.5 μm) was an ultrafine fiber having a flat cross section. Next, the slurry was made into a fiber web by papermaking with a hand mill and dried at 110 ° C. Next, this fiber web was placed on an aperture support, a columnar flow was ejected from a nozzle head containing high-pressure water, the water flow was applied to the fiber web, and it was dried with a dryer. The water pressure was 4 MPa and a plurality of nozzle heads were used. As a result, a non-woven fabric substrate having a surface density of 65 g / m ² in which ultrafine fibers were three-dimensionally entangled with a water flow was obtained.
Next, an ink receiving layer was formed on the nonwoven fabric base fabric in the same manner as in Example 2 to obtain a printing substrate.
The ink receiving layer was formed almost uniformly in the thickness direction on the printing substrate, and printing was possible on both surfaces. Further, the surface density of this printing substrate was 73 g / m ² and the thickness was 0.39 mm. Further, the tensile strength was 106 N / 50 mm width in average in the longitudinal direction and the transverse direction, and the tensile elongation at break was 72% in average in the longitudinal direction and the transverse direction. Moreover, the average value of the longitudinal direction and the horizontal direction was 3.6 N for the tear strength, and the bending resistance was 102 mm for the average value in the vertical direction and the horizontal direction. The air permeability was 15.4 cm ³ / cm ² / sec. In addition, Table 2 shows the results of the evaluation of the sharpness of printing, the dyeing fastness test and the abrasion resistance test.

(Comparative Example 2)
A fiber web made of polyester fibers having an average fiber diameter of 3.5 μm is formed by a melt blow method, and the fiber web is partially fused by a pressure roll made of a pair of emboss rolls and a smooth roll to obtain a surface density. A nonwoven fabric base fabric of 80 g / m ² was obtained.
Next, an ink receiving layer was formed on the nonwoven fabric base fabric in the same manner as in Example 1 to obtain a printing substrate.
The ink receiving layer was formed almost uniformly in the thickness direction on the printing substrate, and printing was possible on both surfaces. Further, the surface density of this printing substrate was 98 g / m ² and the thickness was 0.33 mm. In addition, the average value of the tensile strength in the longitudinal direction and the transverse direction was 73 N / 50 mm width, and the tensile elongation at break was 49% in the average value in the longitudinal direction and the transverse direction. The tear strength was 4.0 N in the longitudinal and lateral averages, and the bending resistance was 120 mm in the longitudinal and lateral averages. The air permeability was 4.9 cm ³ / cm ² / sec. In addition, Table 2 shows the results of the evaluation of the sharpness of printing, the dyeing fastness test and the abrasion resistance test.

Table 1

Table 2

  As is clear from Tables 1 and 2, the printing substrates of Examples 1 to 4 had higher tensile strength values and superior durability compared to Comparative Examples 1 and 2. In addition, the printing substrates of Examples 1 to 4 were excellent in the sharpness of printing, and excellent results were also observed in the dyeing fastness test and the abrasion resistance test.

(A) is an example of the cross section of the splittable fiber used in the present invention, (b) is another example of the cross section of the splittable fiber used in the present invention, and (c) is another cross section of the splittable fiber used in the present invention. An example and (d) are figures which show another example of the cross section of the splittable fiber used by this invention.

Explanation of symbols

1. 1. Resin component Other resin components

Claims (5)

  It consists of a fiber layer containing 50% by mass or more of flat fibers and a fiber layer containing less than 50% by mass of flat fibers, and the constituent fibers of both fiber layers are entangled by a water flow and both fiber layers are integrated. A printing substrate made of a two-layer nonwoven fabric, which contains 30% by mass or more of fibers having a fiber length of 15 mm or more with respect to the entire constituent fibers, and the constituent fibers are bonded by an adhesive regardless of fiber bonding. An ink receiving layer or a toner receiving layer made of the adhesive is provided on both sides.   The fiber layer containing 50 mass% or more of flat fibers is mainly composed of fibers having a fiber length of less than 15 mm, and the fiber layer containing less than 50 mass% of flat fibers is mainly composed of fibers having a fiber length of 15 mm or more. The printing substrate according to claim 1.   The substrate for printing according to claim 1 or 2, wherein the content of the adhesive is less than 10 mass% with respect to the entire constituent fibers.   The base material for printing according to any one of claims 1 to 3, wherein the bending resistance by the cantilever method is 250 mm or less. Tear strength, surface density 100 g / m ² per printing substrate according to any one of claims 1 to 4, characterized in that at least 4N.

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