JP6354649B2 - Sanitary paper - Google Patents

Description

  The present invention relates to sanitary paper mainly used as toilet paper or tissue paper. More specifically, the present invention relates to an environmentally friendly sanitary paper in which waste paper pulp is blended as a raw material.

  Conventionally, as a sanitary paper such as toilet paper or tissue paper, one made of 100% waste paper pulp is known (for example, Patent Document 1). In general, used paper pulp used as a raw material for sanitary paper is a recycled paper pack such as a milk pack or a recycled printing paper containing a coating layer. Sanitary paper made from 100% waste paper pulp is made by recycling paper packs and printing paper, so it is environmentally friendly and can be manufactured at low cost.

  However, sanitary paper with 100% waste paper pulp is inferior to sanitary paper with 100% virgin pulp, which is not a recycled product, in terms of softness and strength. For this reason, it is known that sanitary paper maintaining softness and strength can be produced by using a blend of used paper pulp and virgin pulp at a predetermined ratio as a papermaking raw material (for example, Patent Document 2).

JP 2008-255496 A JP 2009-219562 A

  By the way, recycled paper pulp such as milk cartons has a quality that is relatively close to virgin pulp. Therefore, even if such recycled paper pulp is included in the papermaking raw material, the quality of sanitary paper is maintained to some extent. be able to. However, waste paper pulp in paper packs has the problem of increasing raw material costs because it is easy to use as a recycled product and has good quality. On the other hand, recycled paper pulp made from recycled coated paper with a coating layer contains kaolin, calcium carbonate, and fluorescent dyes, so it has fewer uses compared to used paper pulp in paper packs and has a high quality. Is also inferior. For this reason, it can be said that the contribution to the environment is increased by actively using the waste paper pulp of the coated paper for printing as a raw material.

  However, the waste paper pulp of coated paper for printing contains kaolin, calcium carbonate, and fluorescent dyes. If this is used as a papermaking raw material for sanitary paper, the fluorescent intensity of the sanitary paper will increase too much. There is a problem that it looks bad. That is, if the fluorescent intensity of the sanitary paper becomes too high, it gives the user an impression that it is too white. Further, sanitary paper containing a large amount of waste paper pulp has a problem that it is inferior in softness and strength as compared with a paper containing a lot of virgin pulp.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a sanitary paper exhibiting a color that is kind to eyes in an environmentally-friendly sanitary paper containing a large amount of waste paper pulp of a paper having a coating layer such as a coated paper for printing.

  The present invention relates to sanitary paper. The sanitary paper of the present invention contains waste paper pulp of paper having a coating layer (eg, coated paper for printing) at 50% by weight or more of raw material, and virgin pulp in the remainder of the raw material. And in the sanitary paper of this invention, the whiteness measured based on JISP8148 shall be 75% or more by adjusting the compounding ratio of waste paper pulp and virgin pulp. Further, the fluorescence intensity is kept in the range of 1.5 to 3.0%. Furthermore, the b * value of the hue by the L * a * b * color system measured according to JISP8150 is set to 1.5 to 3.0.

  The “fluorescence intensity” mentioned here is the difference between the value measured using an ultraviolet light removal filter in accordance with JISP8148 and the whiteness measured without using an ultraviolet light removal filter in accordance with JISP8148. means. That is, the fluorescence intensity is the whiteness specified in JISP8148 measured with or without an ultraviolet light removal filter, and from the whiteness measured under normal conditions (with ultraviolet light), using the ultraviolet light removal filter (no ultraviolet light) ) Refers to the numerical value obtained by subtracting the whiteness measured in step (b). Here, the ultraviolet light removal filter cuts light having a wavelength of 390 nm or less at an arbitrary ratio. Fluorescent substances such as fluorescent pigments contained in the coating layer have the property of changing the wavelength of light in the ultraviolet region to visible light. Therefore, by measuring with or without ultraviolet light, the whiteness derived from the fluorescent brightener It can be grasped as a change in degree, that is, fluorescence intensity.

  The “b * value of hue” is based on the L * a * b * color system. The L * a * b * color system indicates a complementary color space specified by three-dimensional coordinates of L *, a *, and b *. The + L * direction is the bright direction, the -L * direction is the dark direction, the + a * direction is the red direction, -a * is the green direction, + b * is the yellow direction, and -b * is the blue direction. When the b * value of the hue is 1.5 to 3.0 as in the present invention, it means that the sanitary paper is somewhat yellowish.

  As in the above configuration, even when the sanitary paper contains waste paper pulp having a coating layer at 50% by weight or more of the raw material, while maintaining the whiteness at 75% or more, the fluorescence intensity is 1.5 to By limiting the b * value of the L * a * b * color system to 1.5 to 3.0 while keeping it at 3.0%, the sanitary paper comes to exhibit a hue that is kind to the eyes. In addition, the sanitary paper of the present invention has a special yellowish hue with a b * value of the L * a * b * color system of 1.5 or more, so it can be differentiated from other ready-made products. Connected. Accordingly, it is possible to provide a sanitary paper exhibiting a characteristic color that is gentle to the eyes, using waste paper pulp such as coated paper for printing as a main raw material.

  In the sanitary paper of the present invention, the content of the used paper pulp in the paper having the coating layer is preferably 60 to 80% by weight, and the content of the virgin pulp is preferably 20 to 40% by weight. The sanitary paper may be composed only of waste paper pulp and virgin pulp of paper having a coating layer. However, the sanitary paper may contain used paper pulp such as a paper pack having no coating layer in addition to the used paper pulp and virgin pulp of the paper having the coating layer.

  As described above, by setting the content of the used paper pulp of the paper having the coating layer to 60% by weight or more, it is possible to manufacture an environmentally friendly sanitary paper at a low cost. In addition, the content of the waste paper pulp is set to 80% by weight or less and a predetermined amount of virgin pulp is blended to suppress the fluorescence intensity, and the b * value of the L * a * b * color system is in a preferable range (1 .5 to 3.0).

The sanitary paper of the present invention preferably has a density measured in accordance with JISP8118 of 0.3 g / cm ³ or more.

  As described above, it is preferable to increase the density of the sanitary paper of the present invention. As a result, the fluorescent intensity of the sanitary paper can be suppressed, and the b * value of the L * a * b * color system can be easily set within a preferred range (1.5 to 3.0). Also, increasing the density improves the strength of sanitary paper. As in the present invention, sanitary paper containing a large amount of waste paper pulp has the property of being soft to the touch and inferior in strength, but by increasing the density, both the softness of the touch and the strength of strength can be achieved. .

The sanitary paper of the present invention preferably has a basis weight measured in accordance with JISP8124 of 16.0 g / m ² or more.

  As in the above configuration, it is preferable to increase the basis weight in the sanitary paper of the present invention. As a result, the fluorescent intensity of the sanitary paper can be suppressed, and the b * value of the L * a * b * color system can be easily set within a preferred range (1.5 to 3.0). In addition, the softness of the hand and the strength of the sanitary paper can be compatible.

  In the sanitary paper of the present invention, the waste paper pulp is preferably waste paper pulp of a coated paper for printing. The coated paper for printing has a coating layer, and this coating layer contains a pigment and an adhesive. In the present invention, sanitary paper having excellent appearance and excellent environmental performance is provided by using waste paper pulp of coated paper for printing including such a coating layer as a raw material.

  The present invention relates to an environmentally-friendly sanitary paper made mainly from waste paper pulp having a coating layer. Such sanitary paper tends to deteriorate in appearance due to an increase in fluorescence intensity due to the fluorescent pigment contained in the used paper pulp coating layer. Therefore, the present invention provides a good-looking sanitary paper that exhibits a gentle hue by suppressing the fluorescence intensity and adjusting the b * value of the L * a * b * color system in the range of 1.5 to 3.0. can do.

Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings. This invention is not limited to the form demonstrated below, The thing suitably changed in the range obvious to those skilled in the art from the following forms is also included.
In the present specification, “A to B” means “A to B”.

The present invention relates to toilet paper, tissue paper, and household hygiene paper used. In particular, the sanitary paper of the present invention is preferably a thin paper having a basis weight of 10 to 25 g / m ² per sheet. In addition, the sanitary paper of the present invention can be made into a product of 2 plies or 3 plies by superimposing two or three or more sheets.

  The sanitary paper of the present invention can be manufactured using a general paper machine. A typical paper machine has a wire part, a press part, a dryer part, a calendar part, and a reel part.

  The wire part is a process in which the injected papermaking raw material (pulp) is dehydrated to form a sheet. In the wire part, the papermaking raw material whose components are prepared in advance is supplied to the forming unit in a state of containing a large amount of moisture, thereby forming a paper layer as a prototype of sanitary paper. A large amount of moisture contained in the papermaking raw material is dehydrated here, and the texture of the wet paper is prepared.

  The press part is a process in which pressure is applied to the papermaking material that has been made into a sheet to further dehydrate it. In the press part, pressure is applied to the wet paper formed in the wire part, and water contained in the wet paper is squeezed out. Here, the surface of the wet paper is smoothed, and at the same time, the density of the pulp component constituting the main part of the wet paper is increased to form a strong wet paper.

  The dryer part is a process in which a sheet of papermaking raw material is introduced into the dryer and completely dried by applying heat. In the dry part, excess water is forcibly evaporated by heating the wet paper that has passed through the press part with a Yankee dryer. As a result, paper obtained by drying the wet paper is obtained. The paper wound around the mirror roll of the Yankee dryer and dried is peeled off from the surface of the mirror roll while being creped by a creping doctor, and is carried out to the subsequent calendar part.

  The calendar part is a process in which the surface of the sheet after drying is stretched while being pressed to smooth the surface of the sheet. That is, in the calendar part, the paper in a nearly completed state is introduced between a pair of calendar rolls, thereby smoothing the surface of the paper and increasing its density.

  The reel part is a step of winding a long paper obtained through each step to form a roll body in which the paper is wound in multiple layers. At the reel part, the finished paper, that is, the base paper of sanitary paper that becomes a piece of toilet paper, is wound up into a roll. After that, two rolls of sanitary paper obtained through the above-mentioned process are prepared, and they are stacked and cut in a separate process, so that two sets of toilet paper products (2-ply) Can be obtained. In addition, by preparing three rolls of sanitary paper base paper, it is possible to obtain a set of three toilet paper products (three plies).

  In the present invention, as a papermaking raw material for sanitary paper, a mixture of used paper pulp and virgin pulp at a predetermined ratio is used. For this reason, the sanitary paper according to the present invention is composed of waste paper pulp and virgin pulp.

  In the present invention, waste paper pulp having a coating layer is used as the waste paper pulp. As paper having a coating layer, it is common to use printing coated paper. The coating layer of the coated paper for printing contains, for example, a pigment and an adhesive (binder). Examples of pigments include kaolin, clay, calcium carbonate, aluminum hydroxide, zinc oxide, barium sulfate, calcium sulfate, silica, activated clay, talc, satin white, lake and other inorganic pigments, and organic pigments such as plastic pigments. Can be mentioned. As the adhesive, ordinary adhesives for coated paper, such as starches such as positive starch, oxidized starch, and thermochemically modified starch, can be appropriately selected and used.

  The waste paper pulp material having a coating layer contains a fluorescent dye. Fluorescent dyes are dyes that absorb ultraviolet light in light, emit blue-violet light when excited, and produce a white color visually. When added to paper, whiteness and brightness appear to increase. It has become visually white. For this reason, the waste paper pulp which has coating layers, such as printing coated paper, contains the fluorescent dye. There are no particular limitations on the type of fluorescent dye contained in the waste paper pulp, and examples include those generally used for papermaking. For example, fluorescent dyes include, for example, aminostilbene, imidazole, oxazole, triazole, coumarin, naphthalimide, pyrazoline, and the like, and one or more of these are appropriately selected. You can select and use. More specifically, examples of fluorescent dyes include diaminostilbene disulfonic acid derivatives, imidazole derivatives, and coumarin derivatives. As the used paper pulp material, it is preferable to use a material containing a fluorescent dye at a concentration of 2 to 6 g / kg of pulp.

  In the present invention, waste paper pulp of paper having such a coating layer is used as a papermaking raw material. Examples of paper having a coating layer include imitation paper (high-quality printing paper with black ink printing), anti-traditional paper (high-quality printing paper with printing generated from bookbinding and printing factories), and color-up paper (with color printing) High-quality printing paper) or mixed office waste paper (paper generated from the office / used copy paper, etc.) can be used.

  Of the raw materials constituting the sanitary paper, the waste paper pulp of the coated paper for printing is contained in 50% by weight or more of the raw material. Specifically, the waste paper pulp of the coated paper for printing is preferably 60% by weight or more of raw material, 70% by weight or more of raw material, 75% by weight or more of raw material, or 80% by weight of raw material. In this way, by containing a large amount of waste paper pulp of the coated paper for printing in the papermaking raw material, it is possible to produce environmentally friendly sanitary paper at low cost. On the other hand, the upper limit of the content of waste paper pulp in the coated paper for printing is preferably 80% by weight of the raw material. There is a concern that if the content of used paper pulp in the coated paper for printing exceeds 80% by weight, the fluorescent intensity of the sanitary paper will be excessively increased due to the fluorescent dye contained in the used paper pulp, and the appearance will deteriorate. . For this reason, it is appropriate that the content of the used paper pulp of the coated paper for printing is 60 to 80% by weight of the raw material.

  The remainder of the sanitary papermaking raw material contains at least virgin pulp. As virgin pulp, cellulose pulp obtained from lignocellulosic materials such as wood is mainly used. Cellulose pulp can be obtained by dehydrating and drying chemical pulp (hardwood pulp: LBKP, softwood pulp: NBKP) obtained by digesting wood chips made of hardwood or conifers, and chemical pulp containing water. Pulp or the like can be used. The sanitary paper may be composed only of the waste paper pulp and virgin pulp of the above-described printing coated paper. In that case, the remainder of the used paper pulp of the coated paper for printing may be virgin pulp out of the papermaking raw materials.

  Moreover, as a papermaking raw material of sanitary paper, the used paper pulp which recycled paper packs, such as a milk pack, for example other than the used paper pulp and virgin pulp of the coating paper for printing mentioned above may contain. However, the main raw material of the sanitary paper of the present invention is waste paper pulp of paper having a coating layer such as coated paper for printing. For this reason, it is preferable that the waste paper pulp of a paper pack is not contained in the papermaking raw material of sanitary paper.

  In addition, publicly known chemicals such as paper strength enhancers and softeners may be added to the papermaking raw materials for sanitary paper. Adding a paper strength enhancer such as dry paper strength or wet strength to papermaking materials has the effect of increasing the strength of sanitary paper, but has the property of reducing the flexibility and smoothness of the paper. ing. In contrast, the addition of a softening agent to the papermaking raw material has the effect of improving the flexibility and feel of the sanitary paper, but has the property of reducing the strength of the sanitary paper. For this reason, a paper strength enhancer may be added to increase the strength of the sanitary paper, and a softener may be added to improve the touch of the sanitary paper.

  As described above, the papermaking raw material of sanitary paper contains a large amount of waste paper pulp of paper having a coating layer. If sanitary paper is made only from such waste paper pulp, the fluorescent intensity of the resulting sanitary paper will be too high. For example, a sanitary paper made of 100% used paper pulp for printing has a fluorescence intensity exceeding 3.0%. Such sanitary paper with high fluorescence intensity gives the impression that the brightness is too high and is bad for the eyes. Therefore, the sanitary paper of the present invention satisfies the following requirements a, b, and c by adjusting the mixing ratio of waste paper pulp and virgin pulp, basis weight of sanitary paper, paper thickness, density, and other various conditions. Preferably.

[A] The whiteness of the sanitary paper is 75% or more.
[B] The fluorescence intensity of the sanitary paper is 1.5 to 3.0%.
[C] The b * value of the hue according to the L * a * b * color system of the sanitary paper is 1.5 to 3.0.
Here, in the present specification, “whiteness” means whiteness measured in accordance with JISP8148. The “fluorescence intensity” means a value indicated by a difference between a value measured using an ultraviolet light removal filter in accordance with JISP8148 and the whiteness measured in accordance with JISP8148. The “b * value of hue according to L * a * b * color system” means the value of the b * value of hue according to the L * a * b * color system measured according to JISP8150.

  As described above, by setting the whiteness of the sanitary paper to 75% or more, a sanitary paper having preferable whiteness can be obtained. The whiteness is particularly preferably 80% or more, or 83% or more.

  Further, by keeping the fluorescent intensity of the sanitary paper in the range of 1.5 to 3.0%, it is possible to avoid giving a bad impression to the user that it is bad for the eyes. Specifically, the fluorescence intensity of the sanitary paper is particularly preferably 1.8 to 2.7%.

  Furthermore, in the present invention, the hue of the sanitary paper is assumed to be yellowish. Specifically, the b * value of the hue of sanitary paper is set to 1.5 to 3.0. Thus, by giving a moderate yellowishness to the sanitary paper, it is possible to give the user an impression that it is kind to the eyes. In particular, the b * value of the hue is preferably 2.0 to 3.0, or 2.22 to 2.8. If the b * value of the hue is too low, the white color becomes strong and the user cannot give an impression that it is gentle to the eyes. On the other hand, if the b * value of the hue is too high, the yellowness becomes too strong, which gives a bad impression. For this reason, in the present invention, the b * value of the hue is in the range of 1.5 to 3.0.

  The a value of the hue of the sanitary paper is not particularly limited. However, the a value of the hue of sanitary paper is preferably in the range of 0 ± 0.5.

In addition, the sanitary paper of the present invention preferably has a density of 0.3 g / cm ³ or more. Here, “density” means a density measured in accordance with JISP8118. Thus, in the present invention, the density of sanitary paper is set to a relatively high value of 0.3 g / cm ³ or more. Thus, increasing the density of sanitary paper contributes to increasing the b * value of the hue of sanitary paper. In the present invention, it is necessary to increase the b * value of the hue of sanitary paper to increase the yellowness. For this reason, it is preferable to increase the b * value of the hue of the sanitary paper by increasing the density of the sanitary paper. Moreover, the tensile strength of sanitary paper can be improved by setting the density of sanitary paper to 0.3 g / cm ³ . Note that the upper limit value of the density of the sanitary paper may be, for example, about 0.5 g / cm ³ .

In addition, the sanitary paper of the present invention preferably has a basis weight of 16.0 g / m ² or more. Here, “basis weight” means a density measured according to JISP8124. Density is measured per sanitary sheet. For example, in a toilet paper product in which two sheets of sanitary paper are stacked, the basis weight of sanitary paper per sheet is measured. As described above, in the present invention, the basis weight of the sanitary paper is set to a relatively high value of 16.0 g / m ² or more. Thus, increasing the basis weight of sanitary paper contributes to increasing the b * value of the hue of sanitary paper. In the present invention, it is necessary to increase the b * value of the hue of sanitary paper to increase the yellowness. For this reason, it is preferable to increase the basis weight of the sanitary paper and to increase the b * value of the hue of the sanitary paper. Further, by setting the basis weight of the sanitary paper to 16.0 g / m ² , the tensile strength of the sanitary paper can be improved. The upper limit value of the basis weight of the sanitary paper may be set to about 16.0 g / m ² , for example.

  In addition, the papermaking conditions and physical property values of the sanitary paper can be appropriately adjusted within a range that satisfies the above-described requirements of a, b, and c. By satisfying these various requirements, it is possible to produce hygienic paper that is easy on the eyes and is produced at low cost, using waste paper pulp, such as coated paper for printing, which is rarely used.

  Table 1 shows a list of various measurement results related to the examples and comparative examples of the present invention. In this example and comparative example, a double (2 ply) or single (1 ply) toilet paper product was used as a measurement target. A double toilet paper product is a stack of two sanitary sheets. A single toilet paper product consists of a single sheet of sanitary paper.

  Hue includes whiteness, L * value of hue by L * a * b * color system, a * value, b * value, and fluorescence intensity. The whiteness was measured according to JISP8148. The hue based on the L * a * b * color system was measured according to JISP8150. The fluorescence intensity was measured using an ultraviolet light removal filter according to JISP8148. A spectral whiteness colorimeter (Suga Tester / Suga / Model: SC-10WP, serial number: CC905803) was used for measurement of various parameters relating to hue.

  The basis weight was measured per sanitary sheet. The basis weight was measured using an electronic balance according to JISP8124.

  Paper thickness was measured per number of toilet paper products. In other words, in the case of double toilet paper products, the paper thickness was measured with two sanitary sheets stacked. The paper thickness was measured according to JISP8118, and a high bridge thickness meter (High Bridge) was used as a measuring instrument.

  The calender pressure is the pressure that presses the surface of the sheet with the calender part in the paper making process.

  Tensile strength and tensile modulus were measured per number of toilet paper products. Tensile strength and tensile modulus were measured according to JIS P8113, and a Tensilon universal material testing machine (ORIENTEC / RTC-1250A) was used as a measuring machine. The tensile elastic modulus is an index of the softness of toilet paper products, and the smaller the value, the softer the value.

  Freeness was measured according to JISP 8121-2, and a Canadian standard freeness tester (Tozai Seiki Co., Ltd./manufacturing number: 4105) was used.

  In Examples and Comparative Examples, as the papermaking raw material pulp, used paper pulp and virgin pulp of printing coated paper were appropriately used. Used paper pulp was blended with imitation paper, anti-reflective paper, colored paper, and mixed office waste paper. The concentration of the fluorescent pigment contained in the waste paper pulp was 2 to 6 g / kg pulp.

The toilet paper product (double) of Example 1 contained 75% by weight of waste paper pulp as a coated paper for printing, and 25% by weight of virgin pulp (hardwood pulp: LBKP). In Example 1, the basis weight was 16.6 g / m ² , the paper thickness was 98 μm , the density was 0.339 g / cm ³ , and the calendar pressure was set to 9 kg / m ² . As a result, the toilet paper product of Example 1 had a whiteness of 84.5, a fluorescence intensity of 1.96, and a hue b * value of 2.36, which contained a large amount of used paper pulp for printing coated paper. , It became a product that exhibited a hue that was kind to the eyes. In addition, Example 1 had sufficient values as a product for tensile strength, tensile modulus, and freeness.

The toilet paper product (single) of Example 2 contained 75% by weight of waste paper pulp as a coated paper for printing, and 25% by weight of virgin pulp (hardwood pulp: LBKP). In Example 2, the basis weight was 21.2 g / m ² , the paper thickness was 69 μm , the density was 0.307 g / cm ³ , and the calendar pressure was set to 5 kg / m ² . As a result, the toilet paper product of Example 2 had a whiteness of 83.5, a fluorescence intensity of 2.61, and a hue b * value of 2.29, while containing a large amount of used paper pulp for printing paper. , It became a product that exhibited a hue that was kind to the eyes. Further, Example 2 had sufficient values as a product for tensile strength, tensile modulus, and freeness.

The toilet paper product (double) of Example 3 contains 60% by weight of waste paper pulp as a coated paper for printing, 20% by weight of hardwood pulp (LBKP) as raw material, and 20% of softwood pulp (NBKP) as raw material. It was supposed to be contained in weight%. In Example 3, the basis weight was 17.1 g / m ² , the paper thickness was 100 μm , the density was 0.342 g / cm ³ , and the calendar pressure was set to 5 kg / m ² . As a result, the toilet paper product of Example 3 has a whiteness of 84.2, a fluorescence intensity of 15.2, a hue b * value of 2.80, and contains a large amount of used paper pulp for printing coated paper. , It became a product that exhibited a hue that was kind to the eyes. Further, Example 3 had sufficient values as a product for tensile strength, tensile elastic modulus, and freeness.

On the other hand, the toilet paper product (double) of Comparative Example 1 contains 100% by weight of the waste paper pulp of the coated paper for printing. In Comparative Example 1, the basis weight was 15.5 g / m ² , the paper thickness was 114 μm , the density was 0.272 g / cm ³ , and the calendar pressure was not applied. As a result, the toilet paper product of Comparative Example 1 had an extremely high fluorescence intensity of 3.22, and the b * value of the hue was as low as 0.70. For this reason, increasing the content of used paper pulp in the coated paper for printing or decreasing the basis weight or density of the product increases the fluorescence intensity and decreases the b * value of the hue and tends to approach white. I know that there is.

The toilet paper product (double) of Comparative Example 2 contains waste paper pulp of coated paper for printing at 50% by weight of raw material and virgin pulp (LBKP) at 50% by weight of raw material. In Comparative Example 2, the basis weight was 15.3 g / m ² , the paper thickness was 113 μm , the density was 0.271 g / cm ³ , and the calendar pressure was not applied. As a result, the toilet paper product of Comparative Example 2 had an excellent fluorescence intensity of 1.67, but the hue b * value was extremely high at 3.38, and the product was too yellow. From this, it can be seen that when the content of virgin pulp is increased and the content of waste paper pulp is decreased, the b * value of the hue increases and tends to approach yellow. Products with a b * value greater than 3.0 are too yellowish and may be disgusted by consumers.

The toilet paper product (double) of Comparative Example 3 did not contain waste paper pulp for coated paper for printing, and contained virgin pulp with 80% by weight of LBKP as raw material and 20% by weight of NBKP as raw material. In Comparative Example 3, the basis weight was 16.6 g / m ² , the paper thickness was 119 μm , the density was 0.279 g / cm ³ , and the calendar pressure was set to 4 kg / cm. As a result, the toilet paper product of Comparative Example 3 had a fluorescent intensity of 0.09 and a hue b * value of 5.68, which was extremely high, resulting in a product with an excessively yellowish hue. From this, it can be seen that when the content of virgin pulp is increased, the b * value of the hue increases and tends to approach yellow. Products with a b * value greater than 3.0 are too yellowish and may be disgusted by consumers.

  According to the present embodiment, the waste paper pulp of the coated paper for printing is 50% by weight or more of the raw material, and the raw material containing the virgin pulp in the remainder of the raw material, the whiteness is 75% or more and the fluorescence intensity is 1.5 to 3.0%. It was proved that sanitary paper having a b * value of 1.5 to 3.0 can be made. Such a sanitary paper has a color that is kind to the eyes. Sanitary paper has high environmental performance because it uses waste paper pulp, which is a coated paper for printing, which is rarely used.

  As mentioned above, in this specification, in order to express the content of the present invention, the embodiment and the example of the present invention were described. However, the present invention is not limited to the above-described embodiments and examples, but includes modifications and improvements obvious to those skilled in the art based on the matters described in this specification.

  The present invention can be suitably used in the manufacturing industry of household sanitary paper and tissue paper products.

Claims (5)

Sanitary paper containing 50% by weight or more of waste paper pulp of paper having a coating layer and virgin pulp in the remainder of the raw material,
The whiteness measured according to JISP8148 is 75% or more,
The fluorescence intensity indicated by the difference between the value measured using an ultraviolet light removal filter according to JISP8148 and the whiteness is 1.5 to 3.0%,
Sanitary paper whose hue b * value according to the L * a * b * color system measured according to JISP8150 is 1.5 to 3.0. The content of the used paper pulp is 60 to 80% by weight of the raw material,
The sanitary paper according to claim 1, wherein the content of the virgin pulp is 20 to 40% by weight of the raw material. The sanitary paper according to claim 2, wherein the density measured according to JISP 8118 is 0.3 g / cm ³ or more. The sanitary paper according to claim 3, wherein the basis weight measured in accordance with JISP 8124 is 16.0 g / m ² or more. The sanitary paper according to any one of claims 1 to 4, wherein the paper having the coating layer is a coated paper for printing.