JP6538425B2 - Printing paper for inkjet printers - Google Patents

Description

  The present invention relates to a sheet for printing using an inkjet printer.

  The inkjet printing method is mainly a method of atomizing liquid ink and directly injecting the ink from the fine holes by pressure or heating. Further, as compared with other methods, multi-coloring is easy, and together with the fine injection holes, high image quality comparable to that of silver salt photographs is realized. And, in order to execute printing not on a large scale but basically on a sheet basis, it has become mainstream in small household printers.

  The form of printing paper used for such inkjet printing includes plain paper type printing paper represented by fine paper, PPC paper, etc. and coated paper type printing having an ink receiving layer containing white pigment on a support It is divided roughly into paper.

  Such printing paper is a so-called paper which uses pulp as a raw material, and specifically, as described in, for example, Patent Document 1, as raw material pulp, chemical pulp, mechanical pulp, deinked waste paper pulp, etc. The wood pulp of the present invention is used as a raw material and made into paper by using a known paper machine.

JP, 2015-85674, A Paragraph number 0023

  Since the printing paper for an ink jet printer is a so-called paper which uses pulp as a raw material, it can be easily broken by pulling it with human fingers, and it can not be said that the durability is high.

  On the other hand, the present inventor developed a polyester non-woven fabric having a special cross-sectional shape (Japanese Patent Application Laid-Open No. 2013-76182). This is a non-woven fabric having polyester long fibers as constituent fibers, wherein the cross-sectional shape of the polyester long fibers is a "substantially Y4 shape" connected vertically and horizontally at the lower end of a substantially Y-shape The polyester nonwoven fabric is characterized by having high rigidity.

  The present inventor has conducted various studies using the above-mentioned polyester non-woven fabric, and a sheet in which a cotton fiber layer is laminated on one side of this polyester non-woven fabric to be integrated can be easily applied to a home inkjet printer. Print of good image quality was applied. The present invention is based on such a discovery. Accordingly, an object of the present invention is to provide a printing sheet for an inkjet printer that is not easily torn.

In the present invention, a long fiber non-woven fabric and a natural fiber web are laminated,
The cross-sectional shape of the long fibers constituting the long-fiber non-woven fabric is connected vertically and horizontally at the lower end of the substantially Y-shape
The gist is a shape (hereinafter referred to as “approximately Y4 shape”), and its single-filament fineness is 10 dtex or more.

  Hereinafter, the present invention will be described in detail.

  The printing paper for an inkjet printer of the present invention is a laminate of a long fiber non-woven fabric and a natural fiber web. Since the printing paper of the present invention is composed of a non-woven fabric composed of long fibers having a special cross-sectional shape as described later, the printing paper has a tension as printing paper while being composed of non-woven fabric. Applicable to In addition, as a lamination | stacking form, even if what a natural fiber web laminated | stacked only on the single side | surface of a long fiber nonwoven fabric, a natural fiber web may be laminated | stacked on both surfaces of a long fiber nonwoven fabric.

The cross-sectional shape of the long fiber constituting the long fiber non-woven fabric has four approximately Y-shaped as shown in FIG. And it connects with the lower end 1 of a substantially Y-shape vertically and horizontally, and it has become a substantially Y4 shape as shown in FIG. This approximately Y4 shape has four concave portions 2, eight convex portions 3 and four small concave portions 4. In addition, high rigidity is achieved by the substantially approximately + character portion 5 at the center and the four approximately V-shaped portions 6 connected to each tip of the substantially + character portion 5. That is, the rigidity is further enhanced by the combination of the substantially rigid + -shaped portion 5 and the substantially V-shaped portion 6 instead of a simple deformed shape such as a hexagon or a Y-shape. In addition, the rigidity is improved and the fiber can not be easily broken by hand because the degree of deformation of the long fiber and the fineness are also as large as 10 dtex or more. The weight per unit area of the long fiber non-woven fabric is preferably in the range of ^{20 to} 50 g / m ² . By setting the fabric weight to 20 g / m ² or more, excellent rigidity can be imparted to the paper. Moreover, by setting the fabric weight to 50 g / m ² or less, the thickness does not become too large, and the ink jet printer can be applied to a commercially available ink jet printer.

  The long-fiber non-woven fabric is composed of a thermoplastic polymer, but from the viewpoint of rigidity and form stability, it is preferable that constituent fibers be integrated by heat bonding. The thermoplastic polymer is preferably a polyester-based polymer because it is excellent in mechanical strength and can impart rigidity. Moreover, although the long fiber (polyester long fiber) comprised with a polyester-type polymer may consist of one type of polyester, it is preferable to combine low melting-point polyester and high melting-point polyester. Furthermore, a composite type in which the substantially V-shaped portion 6 of the cross-sectional shape of the polyester long fiber is formed of a low melting point polyester and the substantially + shaped portion 5 is formed of a high melting point polyester is preferable. By accumulating the composite type polyester long fibers, the low melting point polyester is softened or melted to be solidified, so that a non-woven fabric in which the polyester long fibers are thermally bonded and integrated by the low melting point polyester is easily obtained.

A long-fiber non-woven fabric can be basically obtained by the method described in JP-A-2015-85674, and can be obtained by a conventionally known method except for changing the nozzle holes used in melt spinning. That is, in the method of manufacturing long fiber non-woven fabrics by accumulating long fibers obtained by melt spinning a thermoplastic polymer, the shape of the nozzle holes used in melt spinning is connected vertically and horizontally at the lower end of the Y character In addition, it is to use a shape (hereinafter referred to as “Y4 shape”) in which adjacent Y-shaped / ones and \ ones in parallel are parallel.

  The thermoplastic polymers to be supplied to the Y4 nozzle holes may be of one type or of two types. In particular, a composite type polyester long fiber in which the substantially V-shaped portion 6 described above is formed of low melting point polyester and the substantially + character portion 5 is formed of high melting point polyester using two types of low melting point polyester resin and high melting point polyester resin It should be in the form of

  After the long fibers are obtained, they are collected to form a fibrous web in general. Then, by at least heating the fiber web, the thermoplastic polymer (a polymer having a low melting point when composed of two types of polymers) constituting long fibers is softened or melted, cooled and solidified. Thus, the long fibers are thermally bonded to obtain a long fiber non-woven fabric. The thermal bonding process is a thermal bonding process which is formed by thermal embossing, which is thermally bonded by partially thermocompression bonding, a heat process which is thermally bonded by a heat treatment by a thermal calendering process, or a heat bonding which is formed by a hot air process May be. Moreover, what combined these methods may be used.

  In the present invention, the single fiber fineness of the constituent fibers of the long fiber non-woven fabric is 10 dtex or more in consideration of the rigidity. The larger the single fiber fineness, the better the rigidity tends to be. However, if the single fiber fineness is too large, the unevenness difference between the location where the fiber is present and the location where the fiber is not present will be large, and large irregularities may occur on the paper surface. It will be approximately decitex.

The natural fiber web laminated on one side of the long fiber non-woven fabric is made of cotton fiber or wood pulp in consideration of the fixability of the ink. The basis weight of the natural fiber web may be appropriately selected as desired, but is preferably about ²⁰ to 100 g / m ² . As long as the object of the present invention is achieved, a small amount of fibers other than natural fibers may be mixed in the natural fiber web.

  Examples of the method of laminating the long fiber non-woven fabric and the natural fiber web include a method by a wet sheet-forming method and a method of applying a high pressure water stream by a spunlace method.

  As a method of laminating | stacking by a wet-type paper-making method, the fiber suspension used as the raw material of a paper-making web is specifically prepared first. That is, pulp fibers, which are constituent fibers, are put into water and disintegrated to form a uniform dispersion, and if necessary, a viscosity agent such as a high molecular weight polyacrylamide solution or polyethylene oxide solution is appropriately added to this dispersion. By doing this, a uniformly dispersed fiber suspension (slurry) is prepared. The obtained fiber suspension is made into a papermaking web using a paper machine. The long fiber non-woven fabric described above is placed on the net of the paper machine, and the fiber suspension is allowed to flow on the long fiber non-woven fabric. And since a suitable void (hole) exists in the long-fiber non-woven fabric, the water efficiently flows down from the void between the long-fibers, and the pulp fiber favorably infiltrates the proper void, The fiber nonwoven fabric and the natural fiber web are well combined and integrated.

  As a method of applying a high pressure water stream by the span lace method, it may be performed by a known method. First, a natural fiber web is laminated on a long fiber non-woven fabric, and this laminate is supported on a mesh-like support. A high pressure water stream is then applied from the natural fiber web side of the laminate. The high-pressure water stream collides with the natural fiber web to give kinetic energy to the fibers, and the kinetic energy causes the fibers in the web to be entangled, and the natural fibers are entangled with the long fibers constituting the long fiber non-woven fabric, The fiber non-woven fabric and the natural fiber web are laminated and integrated.

  The sheet obtained by laminating the long fiber non-woven fabric and the natural fiber web thus obtained is applied to a commercially available ink jet printer as printing paper to print appropriate characters and patterns. In addition, in order that a printing surface may adhere | attach an ink favorably, let the natural fiber web side be a printing surface. Also, in order to improve the adhesion of the ink, the natural fiber web side surface may be processed.

  The printing paper for an ink jet printer according to the present invention is obtained by laminating a long fiber non-woven fabric made of long fibers having a specific cross-sectional shape of a substantially Y4 shape and a natural fiber web. And since it has firmness and rigidity since it has a long-fiber non-woven fabric having a specific cross-sectional shape, it is difficult to change its shape as compared with a general non-woven fabric, and it can be applied to a commercially available inkjet printer. Also, as with so-called paper, it has excellent durability without being easily broken.

  EXAMPLES Hereinafter, the present invention will be specifically described by way of examples, but the present invention is not limited to these examples. In addition, each characteristic value in an Example was calculated | required as follows.

(1) Melting point (° C.): Measured at a temperature rising rate of 20 ° C./minute using a differential scanning calorimeter DSC-7 type manufactured by Perkin Elmer.

(2) Weight per unit area of nonwoven fabric (g / m ² ): 10 pieces of 10 cm long × 10 cm wide sample pieces are prepared from the sample in the standard state, the mass (g) of each sample piece is weighed, and the average of the obtained values is obtained The value was converted to the per unit area to obtain the basis weight (g / m ² ) of the non-woven fabric.

 (3) Thickness of non-woven fabric (μm): 10 pieces of 10 cm long and 10 cm wide sample pieces are prepared from the sample in the standard state, and a dial thickness gauge is used according to JIS L 1913 6.1A method (presser hood 25 mmφ , Weight 1.96 kPa) and thickness (μm) were measured.

 (4) Fineness (dtex) of the long fiber constituting the long fiber non-woven fabric: About the mass of 5 points of a sample of 1.8 m in length stored overnight under the environment of temperature 20 ° C. and humidity 60% ) Was used to determine the fineness from the average value.

Example [Production of long-fiber non-woven fabric]
It copolymerizes using 92 mol% of terephthalic acid (TPA) and 8 mol% of isophthalic acid (IPA) as a dicarboxylic acid component, and 100 mol% of ethylene glycol (EG) as a diol component, and low-melting-point polyester (relative viscosity [eta rel] 1. 44, melting point 230 ° C.). To this low melting point polyester, 4.0% by mass of titanium oxide was added as a crystal nucleating agent to prepare a low melting point polyester polymer. On the other hand, it is copolymerized using 100 mol% of terephthalic acid (TPA) as a dicarboxylic acid component and 100 mol% of ethylene glycol (EG) as a diol component, and a high melting point polyester polymer (polyethylene terephthalate, relative viscosity [.eta. Prepared at 260 ° C. Then, using the nozzle holes shown in FIG. 4, a low melting point polyester polymer is supplied to the V-shaped portion, a high melting point polyester polymer is supplied to the + shaped portion, and the spinning temperature is 285 ° C. Melt spinning was performed at 33 g / min. The weight ratio of the low melting point polyester polymer supply amount to the high melting point polyester polymer supply amount was 1: 2.

The filament group discharged from the nozzle hole was introduced into an air sucker inlet 2 m below, and pulled so that the fineness of the composite polyester long fiber became 17 dtex. The composite type polyester long fibers discharged from the air soccer outlet were opened by an opening device, and then accumulated on a moving net conveyor to obtain a fiber web. This fiber web is a hot melt consisting of an embossed roll with a surface temperature of 213 ° C (the area of the tip of each embossed convex part is 0.7 mm ² and the area ratio of the embossed convex part to the whole roll area is 15%) and a flat roll It was introduced into a coating apparatus and thermally fused under the condition of a linear pressure of 300 N / cm between both rolls to obtain a polyester long fiber nonwoven fabric with a basis weight of 40 g / m ² .

[Lamination 1 single-sided lamination]
Using a refined and bleached cotton fiber (fiber length of about 25 to 35 mm), a natural fiber web with a fabric weight of about 30 g / m ² was produced by a sample roller card machine manufactured by Daiwa Kiko Co., Ltd.
Next, the long fiber non-woven fabric and the natural fiber web described above are laminated, and the laminate is placed on a 100 mesh resin net traveling at 10 m / min, water pressure of nozzle diameter 0.1 mm, nozzle pitch 1 mm, water pressure 5 MPa Then, water was injected onto the natural fiber web side of the laminate, and water was further injected twice from the same direction with a water pressure of 14 MPa water pressure to perform hydroentanglement treatment. Thereafter, drying treatment was performed at 140 ° C. to obtain a printing paper of the present invention having a basis weight of 74 g / m ² and a thickness of 480 μm.

[Stacking 2 Double-sided Stacking]
Using a refined and bleached cotton fiber (fiber length of about 25 to 35 mm), a natural fiber web with a fabric weight of about 30 g / m ² was produced by a sample roller card machine manufactured by Daiwa Kiko Co., Ltd.
Next, natural fiber webs are arranged on both sides of the long-fiber non-woven fabric described above to form a three-layer laminate, this laminate is placed on a 100 mesh resin net traveling at 10 m / min, nozzle diameter 0.1 mm, nozzle Water is sprayed on one side of the laminate with a pitch of 1 mm and water pressure of 5 MPa, water with a water pressure of 5 MPa is similarly sprayed on the opposite side, and water is sprayed with a water pressure of 14 MPa twice from the same direction. Also on the opposite surface, the laminate was sprayed twice with water pressure of 14 MPa water pressure to perform hydroentanglement treatment. Thereafter, drying treatment was carried out at 140 ° C. to obtain a printing paper of the present invention having a basis weight of 104 g / m ² and a thickness of 550 μm.

  The two types of printing paper (single-sided lamination, double-sided lamination) were used with the natural fiber web side as the printing surface, high-speed inkjet printer manufactured by Canon Inc. Product name PIXUS MG5530 (ink cartridge used, model number “Magenta 351XL M”, “Black” When introduced into 351 BK, “Yellow 351 XL Y”, “Black 350 XL PGBK”, “Cyan 351 XL C”) and printed with various color digital images, any printing paper is processed without problems in the printer, and the printing paper features A clear color image was printed with less distortion of the deformed and printed image.

It is the figure which showed one substantially Y-shape of the substantially Y4 shape which is a cross-sectional shape of the long fiber which comprises the long fiber nonwoven fabric used for this invention. It is the figure which showed the substantially Y4 shape which is a cross-sectional shape of the long fiber which comprises the long fiber nonwoven fabric used for this invention.

Reference Signs List 1 polyester long fiber transverse cross sectional shape of substantially Y4 shape one lower Y-shaped lower end 2 concave portion formed by approximately Y4 shape 3 convex portion formed by approximately Y4 shape 4 small concave portion formed by approximately Y4 shape 5 Approximately cross portion in approximately Y4 shape 6 Approximately V-shaped portion in approximately Y4 shape

Claims (5)

The long fiber non-woven fabric and the natural fiber web are laminated and integrated,
The cross-sectional shape of the long fibers constituting the long-fiber non-woven fabric is connected vertically and horizontally at the lower end of the substantially Y-shape
A printing paper for an ink jet printer characterized by having a shape (hereinafter referred to as "substantially Y4 shape") and having a single yarn fineness of 10 dtex or more.   The printing paper for an ink jet printer according to claim 1, wherein the long fiber non-woven fabric and the natural fiber web are integrally laminated by entanglement of natural fibers with the long fibers constituting the long fiber non-woven fabric.   The printing paper for an ink jet printer according to claim 1 or 2, wherein the natural fiber web is mainly composed of cotton fibers. 4. The printing paper for an ink jet printer according to any one of claims 1 to 3, wherein the basis weight of the long fiber non-woven fabric is 20 to 50 g / m < ² >. A composite type polyester length in which long fibers constituting long-fiber non-woven fabric are formed of a polyester-based polymer, each substantially V-shaped portion of substantially Y4 shape is formed of low melting point polyester, and other substantially + portions are formed of high melting point polyester The printing paper for inkjet printing machines of any one of Claims 1-4 which consists of fibers.