Sanitary Paper

Abstract

To provide sanitary paper on which clear printing is possible and patterns or characters printed on either the front or back side appear clearly on the other of the front or back side. [Solution] The sanitary paper 1 has a printing surface on the back surface 3b of the base film 3. This prevents misalignment of the multi-color printing plate due to the base film 3 being less likely to stretch even when stretched compared to crepe paper, etc., and enables clear printing because the surface (front surface 3a or back surface 3b) of the base film 3 that becomes the printing surface is smoother than crepe paper, etc. In addition, because the base film 3 is made of polyethylene or polypropylene, the base film 3 and sheet 2 can be easily joined by heat fusion even if, for example, the sheet 2 is made of crepe paper, etc., made of fibers that do not have thermoplasticity, such as natural fibers.

Description

[Technical field]

[0001] This invention relates to sanitary paper. [Background technology]

[0002] Conventionally, sanitary thin papers used for kitchen paper, paper napkins, tissue paper, etc., with patterns printed on them have been proposed (Patent Document 1). The sanitary thin paper in Patent Document 1 is formed, for example, by overlapping the back side of one piece of thin paper with a pattern printed on the back side with the back side of another piece of thin paper, so that the pattern on the back side can be seen through from the front sides of both pieces of thin paper (hereinafter, the "front" that is opposite the back side will be referred to as "front", to distinguish it from the "surface" that is the "surface that forms the outside of an object"). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2004-209082 A Summary of the Invention [Problem to be solved by the invention]

[0004] Incidentally, when printing on the crepe paper or nonwoven fabric (hereinafter, "crepe paper or nonwoven fabric" will also be referred to as "crepe paper, etc.") that constitutes sanitary paper used for paper sheets, paper towels, etc., it is necessary to print with the crepe paper, etc., stretched. However, when the basis weight is, for example, 30 g / m 2 When using relatively thin crepe paper of less than 1 / 2 inch (3 mm), the crepe paper stretches, causing printing defects such as misalignment of the multi-color printing plate. In addition, since the surface of the crepe paper is not smooth, the printed patterns and letters (hereinafter, "patterns and letters" will also be referred to as "patterns, etc.") can become unclear.

[0005] On the other hand, for example, in order to prevent the stretching of crepe paper, the basis weight is set at 30 g / m 2 When using the above-mentioned relatively thick crepe paper, the surface is less smooth than that of thin crepe paper, so printed patterns, etc. become less clear. In addition, the printed patterns, etc. cannot be seen from the back of the printed surface. In order to make the patterns, etc. visible on both sides of the sanitary paper, it is necessary to print on both the front and back of the crepe paper, etc., which increases work time and costs.

[0006] Therefore, the object of the present invention is to provide sanitary paper that allows clear printing and in which patterns or letters printed on either the front or back side appear clearly on the other side, either the front or back side. [Means for solving the problem]

[0007] The sanitary paper of the present invention is characterized in that it comprises multiple sheets and a transparent base film disposed between the sheets and at least a portion of which is bonded to the sheets by thermal fusion, with at least one side of the base film being a printed surface.

[0008] The sanitary paper of the present invention is characterized in that the thickness of the base film is 10 μm to 40 μm.

[0009] The sanitary paper of the present invention is characterized in that the sheet is crepe paper or nonwoven fabric made from natural fibers whose main component is cellulose or chemical fibers whose main component is cellulose.

[0010] The sanitary paper of the present invention is characterized in that the base film is made of polyethylene or polypropylene and its entire surface is bonded to the sheet.

[0011] The processed sanitary paper of the present invention is characterized in that the above-mentioned sanitary paper is impregnated with a liquid. Effect of the Invention

[0012] The sanitary paper of the present invention has the surface of the base film as the printing surface. In this way, the base film is less likely to stretch even when stretched compared to crepe paper, etc., so that it is possible to prevent the position of the multi-color printing plate from shifting, and the surface of the base film that becomes the printing surface is smoother than crepe paper, etc., so that clear printing is possible. In addition, since the base film is generally made of synthetic resin, for example, even if the sheet does not contain synthetic fibers or has a low synthetic fiber content, the base film and the sheet can be easily bonded by heat fusion. Furthermore, since the base film of the sanitary paper of the present invention is transparent, even if a pattern or the like is printed on only one side of the base film, the pattern or the like appears clearly on both the front and back sides of the sanitary paper. In addition, since it is necessary to print on only one side of the base film, work time and costs can be reduced compared to printing on both sides.

[0013] The thickness of the base film of the sanitary paper of the present invention is preferably about 10 μm to 40 μm, so that the base film is less likely to become hard even after being bonded to the sheet by heat fusion, resulting in sanitary paper that is comfortable to use.

[0014] The sanitary paper of the present invention is a sheet of crepe paper or nonwoven fabric made of natural fibers mainly composed of cellulose or chemical fibers mainly composed of cellulose. Therefore, it has a better transparency and patterns printed on the base film can be more clearly seen than sheets made of crepe paper or the like that contain synthetic fibers. In addition to being easier to retain moisture than sheets of crepe paper or the like that contain synthetic fibers, the sheet is soft to the touch and gentle on the skin.

[0015] The sanitary paper of the present invention has a base film made of polyethylene or polypropylene, and its entire surface is bonded to the sheet. This eliminates unnecessary gaps between the base film and the sheet, making the sanitary paper clearer in terms of the patterns printed on the base film through the sheet. In addition, because the base film is made of polyethylene or polypropylene, it does not harden easily even after being bonded to the sheet by heat fusion, making the sanitary paper comfortable to use.

[0016] The processed sanitary paper of the present invention is the above-mentioned sanitary paper impregnated with liquid. Therefore, it can be used as a disposable hand towel or wet tissue. In addition, by adhering the sheet containing moisture to the base film, the pattern printed on the base film can be more clearly seen through the sheet. [Brief description of the drawings]

[0017] [Figure 1] FIG. 2 is a perspective view showing a state in which the sheet and the base film are partially separated in the sanitary paper according to the embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] Hereinafter, with reference to FIG. 1, a sanitary paper 1 according to an embodiment of the present invention will be described. The sanitary paper 1 has a three-layer structure and includes a pair of sheets 2 and a base film 3 disposed between the sheets 2, with a pattern 4 printed on the base film 3. The sanitary paper 1 is formed in a rectangular shape and is used, for example, as household paper such as paper sheets and paper towels for wiping off moisture and dirt. The sanitary paper 1 can also be used as a processed product of the sanitary paper 1, such as disposable hand towels or wet tissues, by impregnating it with a liquid such as a medicinal solution made by adding a disinfectant such as benzalkonium chloride, a preservative, a moisturizer, a detergent, or the like to water to retain moisture. In the following description, the thickness direction of the sanitary paper 1 shown in FIG.

[0019] The sheets 2 are made of crepe paper or nonwoven fabric. The sheets 2 are composed of a front sheet 2a arranged on the upper side of the sanitary paper 1 in the vertical direction X (hereinafter, the "upper side" is also referred to as the "front side") as a surface layer sheet of the sanitary paper 1, and a back sheet 2b arranged on the lower side of the sanitary paper 1 in the vertical direction X (hereinafter, the "lower side" is also referred to as the "back side"). There is no limitation on the type of crepe paper or the like that constitutes each sheet 2, but taking into consideration the light transmittance that allows the pattern 4 printed on the base film 3 to be visible through the sheet 2, the feel of the sanitary paper 1 when in use, the manufacturing cost, and the like, a basis weight of 10 g / m 2 More than 50g / m 2 It is preferable to use the following relatively thin crepe paper, etc.

[0020] The raw material of the crepe paper, etc. used for the sheet 2 is preferably a natural fiber mainly composed of cellulose, such as cotton or pulp, or a chemical fiber mainly composed of cellulose, such as rayon or cupra. The chemical fiber mainly composed of cellulose includes regenerated fibers such as rayon or cupra, as well as semi-synthetic fibers such as acetate. Crepe paper, etc. made from these natural fibers or chemical fibers is more likely to keep the sheet 2 moist when the sanitary paper 1 is impregnated with a liquid (moisture) such as a chemical solution, and compared to those made with other raw materials such as synthetic fibers, the surface of the base film 3 is more easily visible through the sheet 2 from both the front and back of the sanitary paper 1, and the visibility of the pattern 4 printed on the base film 3 is improved.

[0021] Furthermore, when the sanitary paper 1 is used as a wet towel or the like for wiping human skin, it is desirable that the raw material of the sheet 2 be rayon alone. This makes it possible to make the sheet 2 the softest compared to cases in which other raw materials are included, so that the surface sheet that touches the skin during use feels smooth to the touch, resulting in a skin-friendly sanitary paper 1. To make the sanitary paper 1 thus gentle on the skin, the most suitable raw material for the sheet 2 after rayon is cotton, and after cotton, pulp.

[0022] When the sanitary paper 1 is used for wiping the skin as described above, it is preferable not to mix synthetic fibers made of synthetic resins such as polyethylene (PE), polypropylene (PP), or polyethylene terephthalate (PET) into the raw material of the crepe paper, but when it is necessary to manufacture the sheet 2 inexpensively, a certain proportion of synthetic fibers may be mixed in. However, in the sanitary paper 1, the sheet 2 and the base film 3 are joined by heat fusion as described below, and the sheet 2 becomes harder after processing by heat fusion than before processing, which may impair the feel of the sanitary paper 1 when in use, so the proportion of synthetic fibers mixed in needs to be adjusted.

[0023] On the other hand, when using the sanitary paper 1 for wiping objects, it may be preferable for the sanitary paper 1 to have a certain level of strength. In such cases, the synthetic fibers described above are mixed into the raw material such as crepe paper at a ratio of 20% to 50% by mass. This makes the sheet 2 stronger than a sheet made only from natural fibers, recycled fibers, or semi-synthetic fibers, and is therefore suitable for use as sanitary paper 1 for objects. However, even in this case, it should be noted that if the ratio of synthetic fibers mixed exceeds a certain ratio, the sheet 2 will have difficulty retaining liquids (moisture) such as chemical solutions, limiting the uses of the sanitary paper 1.

[0024] The base film 3 is a transparent film arranged between the sheets 2 (the front sheet 2a and the back sheet 2b) as an intermediate layer sheet of the sanitary paper 1. The transparent film does not only refer to a completely transparent film, but also includes a film that has a light transmittance such that when a pattern 4 is printed on either the top surface (hereinafter, the "top surface" is also referred to as the "front surface") 3a of the base film 3 or the bottom surface (hereinafter, the "bottom surface" is also referred to as the "back surface") 3b of the base film 3 as the printing surface, the pattern 4 can be seen through from the opposite side to the printed surface (the other side of the front surface 3a or the back surface 3b). Note that the "surface" of the base film 3 refers to the front surface 3a or the back surface 3b of the base film 3.

[0025] The base film 3 is formed from a synthetic resin (thermoplastic resin) having thermal adhesion (thermoplasticity), such as polyethylene (PE), polypropylene (PP), or polyethylene terephthalate (PET). When the sanitary paper 1 is used as a wet towel or other item for wiping the skin, the base film 3 is preferably made from polyethylene among the above-mentioned thermoplastic resins, and the thickness is preferably from 10 μm to 40 μm. This makes it possible to obtain a base film 3 that is less likely to harden after bonding to each sheet 2 by thermal fusion (thermal fusion processing). The base film 3 in the sanitary paper 1 of this embodiment is made from polyethylene or polypropylene. Note that a thickness of 10 μm to 40 μm does not strictly exclude thicknesses less than 10 μm or more than 40 μm, but includes thicknesses of approximately 10 μm and approximately 40 μm.

[0026] Two types of patterns 4 with different sizes are printed on the base film 3. Specifically, the patterns 4 include a star-shaped pattern 4a that is relatively large, and a star-shaped pattern 4b that is smaller than the pattern 4a. The printed surface on which the patterns 4a and 4b are printed may be at least one of the front surface 3a and the back surface 3b of the base film 3, and in the sanitary paper 1 of this embodiment, the patterns 4a and 4b are printed on the back surface 3b of the base film 3. In this way, since the base film 3 is transparent, the patterns 4a and 4b printed on the back surface 3b can be seen through the front sheet 2a on the front side opposite to the back side of the sanitary paper 1, as shown in FIG. 1. Although not shown, the patterns 4a and 4b printed on the back surface 3b can be seen through the back sheet 2a on the back side of the sanitary paper 1, just like the front side.

[0027] In the sanitary paper 1 of this embodiment, the reverse surface 3b is the printed surface, but the printed surface may be the front surface 3a. In this case, as in the case where the reverse surface 3b is the printed surface, the patterns 4a, 4b printed on the front surface 3a are visible from both the front and back sides of the sanitary paper 1. In addition, in consideration of reducing work time and manufacturing costs, it is preferable to print only one of the front surface 3a or the reverse surface 3b of the base film 3, but both the front surface 3a and the reverse surface 3b may be printed surfaces.

[0028] The printing method of the pattern 4 can be gravure printing, flexographic printing, or digital printing such as an inkjet method. In the sanitary paper 1 of this embodiment, an example is shown in which star-shaped patterns 4a and 4b of different sizes are printed, but the pattern and color of the pattern are arbitrary. Furthermore, in addition to patterns such as designs, letters may be printed on the printing surface. The entire front surface 3a of the base film 3 is bonded to the front sheet 2a, and the entire back surface 3b is bonded to the back sheet 2b by heat fusion processing. This eliminates unnecessary gaps between the base film 3 and each sheet 2, compared to when only a portion of the base film 3 is bonded to each sheet 2, so that the patterns 4a and 4b printed on the base film 3 can be more clearly seen through each sheet 2 from both the front and back sides of the sanitary paper 1.

[0029] In the method of processing by heat fusion, for example, the back sheet 2b, the base film 3, and the front sheet 2a are laminated in this order from below, and then heated and pressed using a smooth roll or an embossed roll having unevenness on the entire surface. At this time, for example, when the raw material of the base film 3 is polyethylene, the temperature is heated at 100 to 130 degrees, when the raw material of the base film 3 is polypropylene, the temperature is heated at 120 to 150 degrees, and when the raw material of the base film 3 is polyethylene terephthalate, the temperature is heated at 130 to 160 degrees. In this way, the base film 3 and each sheet 2 can be easily bonded. Note that the above-mentioned temperatures are merely examples, and need to be adjusted according to conditions such as the thickness of each sheet 2 and the base film 3, the room temperature of the work place where the processing by heat fusion is performed, and the processing speed by heat fusion (heating time and pressing time by the roll).

[0030] In addition, in the sanitary paper 1 of this embodiment, the entire front surface 3a and the back surface 3b of the base film 3 are bonded to the front sheet 2a and the back sheet 2b by heat fusion processing using a smooth roll or an embossing roll having unevenness on the entire surface. However, as another heat fusion processing method, for example, an embossing process using an embossing roll having a protrusion on a part of the outer circumferential surface may be used to partially heat and pressurize the base film 3 to bond only a part of the base film 3 to each sheet 2. In that case, for example, the interval between the protrusions provided at regular intervals on the embossing roll may be made longer, or the shape of the protrusions may be made to have a hole in the center, so that only a part of the base film 3 heated by the protrusions shrinks when the temperature drops, thereby wrinkled the sanitary paper 1. In this way, in the wrinkled sanitary paper 1, a large gap is generated between each sheet 2 and the base film 3 in the part where the base film 3 is not bonded, and the sanitary paper 1 can be made thick. When the heat fusion process is partially performed by embossing, the heating temperature for each raw material of the base film 3 is the same as that when the above-mentioned smooth roll or the embossing roll having unevenness on the entire surface is used.

[0031] Next, the effects of the sanitary paper 1 and products made from the sanitary paper 1 will be described. The sanitary paper 1 has the back surface 3b of the base film 3 as the printing surface. In this way, the base film is less likely to stretch even when stretched compared to crepe paper, etc., and thus it is possible to prevent the position of the multi-color printing plate from shifting, and the surface (front surface 3a or back surface 3b) of the base film 3, which is the printing surface, is smoother than crepe paper, etc., so that clear printing is possible. In addition, since the raw material of the base film 3 is polyethylene or polypropylene, even if the sheet 2 is made of crepe paper, etc., made of fibers that do not have thermoplasticity, such as natural fibers, the base film 3 and the sheet 2 can be easily joined by heat fusion. Furthermore, since the base film 3 is transparent, the patterns 4a and 4b printed on the back surface 3b of the base film 3 are clearly visible on both the front side and the back side of the sanitary paper 1. In addition, since the sanitary paper 1 is printed only on the back surface 3b of the base film 3, it is possible to reduce work time and costs compared to printing on both the front surface 3a and the back surface 3b.

[0032] In addition, in the sanitary paper 1, if the base film 3 is made of polyethylene or polypropylene and has a thickness of 10 μm to 40 μm, it is less likely to become hard after being bonded to each sheet 2 by heat fusion processing, and the feel is good. Furthermore, if the sheet 2 is made of crepe paper or the like made of natural fibers mainly composed of cellulose or chemical fibers (regenerated fibers or semi-synthetic fibers) mainly composed of cellulose, the sheet 2 has a better sense of transparency and the patterns 4a, 4b can be more clearly seen than when the sheet 2 is made of crepe paper or the like made of synthetic fibers. Furthermore, in addition to the sheet 2 being more likely to retain moisture than when the sheet 2 is made of crepe paper or the like made of synthetic fibers, the sheet 2 is soft to the touch and the sanitary paper 1 is gentle on the skin. Furthermore, since the entire surface of the base film 3 is bonded to each sheet 2, there is no unnecessary gap between the base film 3 and each sheet 2, and the patterns 4a, 4b printed on the back surface 3b of the base film 3 can be more clearly seen through each sheet 2.

[0033] Furthermore, in processed products made from sanitary paper 1 that has been impregnated with a liquid such as a chemical solution and retains moisture, such as disposable hand towels and wet tissues, each moist sheet 2 adheres to the base film 3, making the patterns 4a, 4b printed on the back surface 3b of the base film 3 more clearly visible through each sheet 2.

[0034] Although the embodiment of the present invention has been described in detail above, the present invention is not limited to the above embodiment. Furthermore, the present invention can be modified in various ways without departing from the scope of the claims of the utility model registration.

[0035] For example, in the sanitary paper 1 according to this embodiment, the sheet 2 is composed of two sheets, a front sheet 2a and a back sheet 2b, but the sheet 2 may be laminated with three or more sheets. The raw material of the crepe paper used as the sheet 2 is not limited to natural fibers, recycled fibers, or semi-synthetic fibers, and may contain other fibers such as synthetic fibers. Furthermore, the thickness of the sheet 2, the type of the crepe paper used as the sheet 2, and the raw material and thickness of the base film 3 are also arbitrary. [Explanation of symbols]

[0036] 1. Sanitary paper 2 seats 2a Front sheet 2b Back sheet 3. Base film 3a Top side 3b Bottom side 4,4a,4b Pattern X vertical direction

Claims

1. The present invention comprises a plurality of sheets and a transparent base film disposed between the sheets and at least a portion of which is bonded to the sheets by thermal fusion, At least one surface of the base film is a printed surface, A sanitary paper characterized by:

2. The thickness of the base film is 10 μm to 40 μm.

2. The sanitary paper according to claim 1 .

3. The sheet is a crepe paper or a nonwoven fabric made of natural fibers mainly composed of cellulose or chemical fibers mainly composed of cellulose.

3. The sanitary paper according to claim 2.

4. The base film is made of polyethylene or polypropylene and has its entire surface bonded to the sheet.

4. The sanitary paper according to claim 3.

5. The sanitary paper according to any one of claims 1 to 4 is impregnated with a liquid. A processed sanitary paper product characterized by the above.

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