JP2007038598A - Pearl paper, and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pearl (glossy) paper which is rich in design property while having a great contrast in the pearl gloss, and used for performing truth/falseness judgement by applying it to securities and the like, owing to its constitution and manufacturing method which are quite different from conventional ones. <P>SOLUTION: This pearl paper has a pearl layer 2 containing a pearl pigment 3 and a polyolefin-based fine particles 4 on a base material 1. Since the polyolefin-based fine particles 4 works so as to interrupt the reflection of the pearl pigment 3, there is almost no pearl gloss in this state. In the meantime, when embossing process is applied to the pearl layer 2 by hot plate pressing, a part or the whole of the polyolefin-based fine particles 4 at the embossed sections (recess sections) is so changed (molten or crushed) as not to affect the reflection of the pearl pigment 3. Thus, there is almost no pearl gloss before the hot plate pressing, and the pearl gloss is made to manifest itself by performing the hot plate pressing, and thus, the truth/falseness judgement is performed by applying it to securities and the like. A pearl (glossy) paper exhibiting a great contrast in the pearl gloss, and being rich in design property is realized. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to pearl (glossy) paper that can be used for decorative paper such as wrapping paper and wallpaper, and for securities that are required to be prevented from forgery.

  As a glittering decorative paper used for decorative paper such as wrapping paper and wallpaper, there is pearl gloss embossed paper. Conventional pearl gloss embossed paper is manufactured by coating pearl ink on embossed paper or embossing on pearl glossy paper.

  On the other hand, in Patent Document 1, a light interference reflective layer in which a pearl pigment is mixed is formed on one surface of a substrate such as paper, and an uneven pattern having a certain regularity is provided on the upper surface of the light interference reflective layer. There is a description regarding a glittering decorative sheet in which a transparent resin layer is formed.

JP-A-5-338071

  The above-mentioned conventional pearl gloss embossed paper and glittering decorative sheet have a problem that the pearl gloss is slightly different due to the unevenness of the emboss, but the contrast is small and the design is poor.

  Accordingly, an object of the present invention is to provide pearl (glossy) paper having a large pearly luster contrast and high designability by a completely different configuration and manufacturing method from the conventional one.

  It is another object of the present invention to provide a pearl (glossy) paper that can be judged as authentic by applying it to securities.

The present invention made to solve the above problems has the following configuration.
(1) A pearl paper comprising a pearl layer containing a pearl pigment and polyolefin fine particles on a substrate.
(2) A concave portion is formed in a part of the pearl layer, and the polyolefin fine particles do not exist in a region where the concave portion is formed, or there are fewer polyolefin fine particles than other regions. (1) Pearl paper.
(3) The pearl paper according to (1) or (2), wherein the pearl pigment has an average particle diameter of 1 to 100 μm and the polyolefin fine particles have an average particle diameter of 0.5 to 15 μm.
(4) A method for producing pearl paper, comprising a step of forming a pearl layer on a substrate using a pearl ink containing a pearl pigment and a polyolefin-based fine particle aqueous dispersion in a binder resin.
(5) The pearl ink according to (4), wherein the pearl ink contains 50 to 250 parts by weight of the pearl pigment and 60 to 240 parts by weight of the polyolefin fine particles with respect to 100 parts by weight of the solid content of the binder resin. Paper manufacturing method.
(6) The pearl paper according to (4) or (5), comprising a step of embossing the pearl layer by hot pressing to denature a part or all of the polyolefin fine particles in the embossed portion. Production method.
(7) The pearl paper according to any one of (4) to (6), wherein the pearl pigment has an average particle size of 1 to 100 μm, and the polyolefin fine particles have an average particle size of 0.5 to 15 μm. Production method.

  The pearl paper of (1) has a pearl layer containing a pearl pigment and polyolefin fine particles that are modified by heat or pressure, and the polyolefin fine particles act to block the reflection of the pearl pigment. In, there is almost no pearl luster. On the other hand, when the pearl layer is embossed by hot pressing, part or all of the polyolefin fine particles in the embossed part (concave part) is modified (melted or crushed), and the reflection of the pearl pigment is affected. Can not be. Thus, since there is almost no pearl luster before hot pressing and pearl luster can be expressed by performing hot pressing, authenticity can be judged by applying to securities etc., for example.

  In the pearl paper of (2), a concave portion is formed by embossing the pearl layer by hot pressing, and the polyolefin fine particles are not present in the region where the concave portion is formed, or other region When the amount of the polyolefin-based fine particles is less than the above, only the concave portions clearly express pearl luster. For this reason, a pearl (glossy) paper having a large pearly luster contrast and rich in design is realized.

  According to the method for producing pearl paper of (4), there is little pearl luster before hot pressing like the pearl paper of (1). It can be easily manufactured in a process.

  According to the method for producing pearl paper of (6), pearl (glossy) paper having a high pearl gloss contrast and rich design can be easily produced in a simple process like the pearl paper of (2).

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 is a cross-sectional view schematically showing the pearl paper of the present invention before pearl gloss is developed. FIG. 2 is a cross-sectional view schematically showing the pearl paper of the present invention after the pearl paper of FIG. 1 is embossed by hot pressing. In these figures, 1 is a base material, 2 is a pearl layer, 3 is a pearl pigment, 4 is a polyolefin fine particle, and 5 is a recess in an embossed portion.

  As the substrate 1, a sheet-like material such as paper, woven fabric, non-woven fabric, or resin film can be used.

  The pearl layer 2 can be formed by applying or printing a pearl ink containing at least a pearl pigment and a polyolefin fine particle aqueous dispersion in a binder resin on the entire surface or a part of the substrate 1.

  As the binder resin, those having a glass transition temperature Tg of 80 ° C. or lower are preferable so that they can be easily embossed by hot pressing, and thermoplastic resins such as acrylic resins, polyester resins, and vinyl chloride-vinyl acetate copolymers are preferable. These may be used alone or in combination.

  The pearl pigment 3 is a pigment that exhibits pearly luster based on the interference action of light. For example, a natural pearlescent pigment collected from fish scales or a natural or synthetic mica as a main component, and the surface thereof is titanium dioxide. Metal oxides such as iron oxide, zirconium oxide and tin oxide, or those coated with various color pigments are used.

  The pearl pigment preferably has an average particle size of 1 to 100 μm, and particularly preferably has an average particle size of 10 to 40 μm. If the average particle size is too small, the pearl gloss after embossing is weak, the contrast of the pearl gloss is small, and the design property tends to be poor. On the other hand, if the average particle size is too large, pearly luster will appear before embossing, and the contrast of pearly luster after embossing will be small and the design will tend to be poor.

  The pearl pigment is preferably blended in an amount of 50 to 250 parts by weight, particularly preferably 80 to 100 parts by weight, based on 100 parts by weight of the binder resin solid content. When the amount of the pearl pigment is too small, the pearl gloss after embossing is weak, the contrast of the pearl gloss is small, and the design property tends to be poor. On the other hand, when there are too many pearl pigments, pearl luster will appear before embossing, and the contrast of pearl luster after embossing will be small, and the design will tend to be poor.

  The polyolefin-based fine particle aqueous dispersion to be contained in the pearl ink is obtained by neutralizing the acid group of a polyolefin-based resin having an acid group such as a carboxyl group. A method for preparing a polyolefin fine particle aqueous dispersion by neutralizing a polyolefin resin is not particularly limited. For example, a polyolefin resin is added to heated water, and a base such as ammonia is stirred and mixed. Can be added to neutralize the acid groups of the polyolefin resin and disperse in water. Examples of polyolefin resins include maleic acid-modified polyethylene, polypropylene, polybutadiene, polyisoprene and hydrogenated products thereof, (meth) acrylic acid-modified polyethylene, polypropylene, polybutadiene, polyisoprene and hydrogenated products thereof. And ethylene- (meth) acrylic acid copolymer.

  Specific examples of the polyolefin-based fine particle aqueous dispersion suitably used in the present invention include Chemipearl W401 (PE aqueous dispersion), Chemipearl WP100 (PP aqueous dispersion) and the like (trade names, Mitsui Chemicals, Inc.). )).

  The polyolefin fine particles 4 preferably have an average particle size of 0.5 to 15 μm, and particularly preferably have an average particle size of 1 to 5 μm. If the average particle size is too small, the reflection of the pearl pigment cannot be sufficiently blocked, and the pearl luster appears before embossing, and the contrast of the pearl luster after embossing is small and the design tends to be poor. . On the other hand, if the average particle size is too large, it will be difficult to develop pearly luster by embossing.

  The softening point of the polyolefin fine particles is preferably 150 ° C. or lower. The polyolefin fine particles are preferably added in an amount of 60 to 240 parts by weight, particularly preferably 12 to 20 parts by weight, based on 100 parts by weight of the binder resin solid content. If there are too few polyolefin-based fine particles, the reflection of the pearl pigment cannot be sufficiently blocked, and pearly luster appears before embossing, and the contrast of pearly luster after embossing is small and the design tends to be poor. . On the other hand, if there are too many polyolefin fine particles, pearl luster will be inhibited and pearl luster may not be obtained even after embossing.

  The thickness of the pearl layer 2 is preferably 5 to 10 μm. If it is too thin, it is difficult to emboss, and the embossed part has a weak pearly luster, and the pearly luster contrast is small and the design tends to be poor. On the other hand, if it is too thick, the pearl luster is improved, but the coating strength is lowered.

  By forming the pearl layer 2 on the substrate 1 using the pearl ink described above, the pearl paper of the present invention having the configuration as shown in FIG. 1 is obtained. This pearl paper acts so that the polyolefin-based fine particles 4 block the reflection of the pearl pigment 3, and therefore, there is almost no pearl luster in this state.

  Next, as shown in FIG. 2, the pearl layer 2 is embossed by hot pressing to modify (melt or crush) part or all of the polyolefin fine particles in the embossed portion (recessed portion 5). It is possible to prevent the reflection of the pearl pigment from being affected.

  The conditions for hot pressing can be appropriately set depending on the thickness of the pearl layer 2 and the like. For example, the temperature is 30 to 180 ° C., the pressure is 0.16 to 0.4 MPa (Gauge), and the pressing time is 1.0 to 10.0 seconds. Can be performed under the following conditions.

  As described above, the pearl paper of the present invention shown in FIG. 1 before hot pressing has almost no pearly luster, and can be expressed by performing hot pressing. You can make an authenticity judgment.

  Further, the pearl paper of the present invention shown in FIG. 2 after the hot pressing partially expresses the pearl luster clearly only in the recess 5, has a large pearl luster contrast and is rich in design, and is a decorative paper such as wrapping paper or wallpaper. As a product value is high.

  Examples of the present invention will be described below, but the present invention is not limited to these examples.

(Example 1)
Pearl ink was prepared with the following composition.
・ Aqueous acrylic resin 10.0 parts by weight (trade name: 3DR-057 / manufactured by Taisei Fine Chemical Co., Ltd.)
・ Aqueous acrylic resin 10.0 parts by weight (trade name: SE-2223L / manufactured by Taisei Fine Chemical Co., Ltd.)
Pearl pigment (particle size 10-60 μm, no surface treatment) 3.0-15.0 parts by weight (trade name: Iriodin 219 / Merck)
-PE water dispersion (average particle size 1 μm) 8.8-35.4 parts by weight (trade name: Chemipearl W401 / Mitsui Chemicals)

The pearl ink was applied onto OCR paper (104.7 g / cm ² ) with a bar coater # 10 to obtain a pearl paper as shown in FIG. The thickness of the pearl layer 2 of this pearl paper is 8 μm.

  Next, hot pressing was performed using a thermal gradient tester under conditions of a temperature of 30 to 180 ° C., a pressure of 0.16 to 0.4 MPa (Gauge), and a press time of 1.0 to 10.0 seconds, as shown in FIG. A pearl paper like that was obtained.

(Example 2)
The PE water dispersion of Example 1 was changed to a PP water dispersion (trade name: Chemipearl WP100, average particle size 1 μm / manufactured by Mitsui Chemicals Co., Ltd.). Coating and hot pressing were performed.

Example 3
The pearl pigment of Example 1 was changed to the trade name Iriodin Ultra 7219 WNT (average particle size 10 to 40 μm, with surface treatment / manufactured by Merck & Co., Inc.). A hot press was performed.

Example 4
The pearl pigment of Example 1 was changed to the trade name Iriodin 223 (particle size 5 to 25 μm, no surface treatment / Merck), and other than that, ink was formed in the same manner as Example 1, and coating and hot pressing were performed. It was.

(Example 5)
The coating and hot pressing were performed in the same manner as in Example 1 except that the coating of pearl ink was performed with a bar coater # 20. The thickness of the pearl layer 2 of this pearl paper was 15 μm.

(Example 6)
Coating and hot pressing were performed in the same manner as in Example 1 except that the coating of pearl ink was performed with a bar coater # 4. The thickness of the pearl layer 2 of this pearl paper was 2 μm.

(Example 7)
Coating and hot pressing were performed in the same manner as in Example 1 except that the pearl ink was coated with a bar coater # 30. The thickness of the pearl layer 2 of this pearl paper was 20 μm.

(Example 8)
The PE water dispersion of Example 1 was changed to 8.0 parts by weight, and other than that, ink was formed in the same manner as in Example 1, and coating and hot pressing were performed.

Example 9
The PE aqueous dispersion of Example 1 was changed to Chemipearl W401 having an average particle size of 9.5 μm, and other than that, ink was formed in the same manner as in Example 1, and coating and hot pressing were performed.

(Comparative example)
The PE water dispersion of Example 1 was changed to cross-linked PMMA (trade name: MBP-8 / manufactured by Sekisui Chemical Co., Ltd.), and other than that, ink was formed in the same manner as in Example 1, coating, hot pressing Went.

  Table 1 shows the results of evaluating the pearly luster of the pearl paper before and after hot pressing and the contrast of the pearly gloss before and after hot pressing created in the above examples and comparative examples.

It is sectional drawing which shows typically the pearl paper of this invention before expressing pearl luster. It is sectional drawing which shows typically the pearl paper of this invention after embossing by hot press.

Explanation of symbols

1: Base material 2: Pearl layer 3: Pearl pigment 4: Polyolefin-based fine particle 5: Recessed portion of embossed portion

Claims (7)

  A pearl paper comprising a pearl layer containing a pearl pigment and polyolefin fine particles on a substrate.   A concave portion is formed in a part of the pearl layer, and the polyolefin fine particles are not present in a region where the concave portion is formed, or the polyolefin fine particles are less than other regions. Item 1. The pearl paper according to item 1.   3. The pearl paper according to claim 1, wherein the pearl pigment has an average particle diameter of 1 to 100 μm, and the polyolefin fine particles have an average particle diameter of 0.5 to 15 μm.   A method for producing pearl paper, comprising a step of forming a pearl layer on a substrate using a pearl ink containing a pearl pigment and a polyolefin-based fine particle aqueous dispersion in a binder resin.   5. The pearl paper according to claim 4, wherein the pearl ink contains 50 to 250 parts by weight of the pearl pigment and 60 to 240 parts by weight of the polyolefin fine particles with respect to 100 parts by weight of a binder resin solid content. Manufacturing method.   The method for producing pearl paper according to claim 4 or 5, further comprising a step of embossing the pearl layer by hot pressing to denature a part or all of the polyolefin fine particles in the embossed portion.   The method for producing pearl paper according to any one of claims 4 to 6, wherein the pearl pigment has an average particle size of 1 to 100 µm, and the polyolefin fine particles have an average particle size of 0.5 to 15 µm.

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