JP2018168514A - Chemical liquid-impregnated substrate and production method thereof - Google Patents

Abstract

An object of the present invention is to provide a chemical-impregnated base material that has appropriate chemical-impregnating property and internal bonding strength, and has strength that can withstand a cutting process and a chemical-liquid impregnation process. SOLUTION: A chemical solution-impregnated substrate containing mercerized pulp and non-mercerized pulp, wherein the mercerized pulp has a Canadian standard freeness (freeness) of 650 to 750 ml CSF and a density of 0.30 to 0.30. 0.38 g/cm3, and JAPAN TAPPI No. 18-2 (Paper and paperboard-Internal bond strength test method-Part 2: Internal bond tester method) is characterized by having an internal bond strength of 50 mJ or more. [Selection drawing] Fig. 2

Description

  The present invention relates to a chemical liquid-impregnated base material and a method for producing the same, and more particularly to a chemical liquid-impregnated base material having an appropriate chemical liquid impregnation property and internal bond strength and having a strength that can withstand a cutting process and an impregnation process.

  Conventionally, a period indicator for indicating an effective period of an insect repellent or a deodorant is known. This type of period indicator is obtained by impregnating a chemical solution impregnated base material with a room temperature volatile chemical solution, so that a predetermined display (such as an indication of the end of the effective period) is exposed as the chemical amount changes over time. It is configured. Various proposals have been made for the period indicator and the chemical liquid-impregnated base material in order to impart necessary characteristics.

  As a technique related to the period indicator, for example, Patent Document 1 discloses a substrate material made of a chemical-permeable material and a chemical-permeable material partially laminated on the surface of the substrate material and having a low refractive index for light. There has been proposed a chemical solution-containing indicator characterized by a configuration in which a room-temperature volatile chemical is contained in a sheet material composed of a display unit. Patent Document 2 includes a base material having liquid permeability and a display part at the end of a period made of a material having a liquid permeability and a low refractive index with respect to light partially laminated on the base material. A period indicator in which a liquid crystal-impervious and gas-permeable region initial display portion is formed has been proposed.

  Appropriateness necessary for the chemical liquid-impregnated base material includes the chemical liquid impregnation rate, the chemical liquid retention amount, the internal bond strength that can withstand the cutting process and the chemical liquid impregnation process, in addition to the above-described period indicator function. Hereinafter, the two physical properties of the chemical solution impregnation rate and the chemical solution retention amount may be collectively referred to as “chemical solution impregnation”.

Next, Patent Document 3 discloses impregnated paper with a surface layer, an intermediate layer composed of one or more layers, and a multilayer paper impregnated with a back layer, wherein at least one of the back layer or the intermediate layer is a liquid absorbing layer, It is formed using pulp containing at least non-wood fibers, and the surface of the back layer is characterized by an oil absorption of 0.5 to 9.5 seconds. In this impregnated paper, the non-wood fibers are blended so that the blending ratio of the type rags of pulp is 20 to 80%, and cotton linter pulp is used as such non-wood fibers. Further, the disaggregation freeness is 600 to 700 cc, the Krem water absorption (longitudinal) is 80 to 100 mm, and the density is 0.40 to 0.60 g / cm ³ . Furthermore, an indicator board in which a coating layer containing at least silica is formed on the surface of the impregnated paper has also been proposed.

  Patent Document 4 includes an impregnated paper composed of multi-layered paper of a surface layer, an intermediate layer composed of one or more layers, and a back layer, and an indicator mount composed of a coating layer formed on the surface of the impregnated paper. In the impregnated paper, the non-wood fiber is blended so that the blending ratio of the type rags of pulp is 20 to 80%, the surface layer is a colored layer, the back layer and the middle layer are liquid absorbing layers, The oil absorption of the surface on the back layer side is 0.5 to 9.5 seconds, and the coating layer contains 10 to 50% by mass of silica with an average particle diameter of 3 to 8 μm as a pigment as a binder, A vinyl acetate resin, containing toluene as a solvent and having a peel strength of 0.35 to 1.10 MPa has been proposed.

Moreover, in patent document 5, it is a chemical | medical solution impregnation base material by which the 2nd layer consisting of a cellulose fiber and a synthetic fiber is laminated | stacked between the 2nd layer of the 1st layer and the 3rd layer mainly consisting of a cellulose fiber, The blending ratio of cellulose fiber and synthetic fiber is 20 to 80:80 to 20% by weight, the cellulose fiber contains at least 50% by weight of mercerized pulp or cotton linter pulp, and the synthetic fiber is the main fiber and binder fiber. The blend ratio of the main fiber and the binder fiber is 20 to 80:80 to 20% by weight, and the layer ratio of the first layer, the second layer, and the third layer is 45 to 35:30 to 10:45 to 35% by weight. The basis weight of the chemical liquid impregnated base material is 75 to 500 g / m ² and the density is 0.25 to 0.50 g / cm ³ .

  As described above, various proposals have been made to improve the chemical solution impregnation property and peel strength of the chemical solution impregnated base material. Here, “improvement of chemical solution impregnation” includes improvement of chemical solution impregnation rate and increase of chemical solution retention amount. When the chemical solution impregnation rate is improved, that is, shortened, the processing time in the chemical solution impregnation step is shortened, so that the processing rate is shortened and the entire manufacturing process is shortened. Further, when the amount of the chemical solution is increased, the necessary amount of the chemical solution can be held in a narrower area, so that there is an advantage that the product can be downsized. In order to improve such chemical solution impregnation properties, Patent Documents 3 and 4 devise a method of blending cotton linter pulp into the absorbent layer and setting the disaggregation freeness to 600 to 700 cc. The mixing ratio of the cellulose fiber and the synthetic fiber is 20 to 80:80 to 20% by weight, and the cellulose fiber contains at least 50% by weight of mercerized pulp or cotton linter pulp.

  However, high blending of mercerized pulp and cotton linter pulp improves the chemical solution impregnation speed, but on the other hand, the peel strength decreases, so there is a problem that the possibility of troubles such as turning the cut edge during cutting is increased. is there. In this regard, in Patent Document 5, an expensive binder fiber is blended in order to prevent a decrease in peel strength, and in order to obtain a strength that can withstand a processing step such as a cutting step or a chemical solution impregnation step while maintaining high chemical solution impregnation properties. Needed expensive raw materials.

No. 05-000938 Japanese Patent No. 4336650 JP 2010-084278 A JP 2010-197815 A Japanese Patent Laying-Open No. 2015-193954

  The present invention has been made in view of such problems, and the object of the present invention is to have an appropriate chemical solution impregnation property and internal bond strength, and a chemical solution that can withstand the cutting process and the chemical solution impregnation process. It is to provide an impregnated base material at low cost.

  Other objects and operational effects of the present invention will be easily understood by those skilled in the art by referring to the following description.

The chemical-impregnated base material of the present invention is a chemical-impregnated base material containing at least mercerized pulp and non-mercelized pulp, and the mercerized pulp has a Canadian standard freeness of 650 to 750 ml CSF. , The density is 0.30 to 0.38 g / cm ³ , and JAPAN TAPPI No. The internal bond strength measured by 18-2 (paper and paperboard-internal bond strength test method-part 2: internal bond tester method) is 50 mJ or more.

  According to such a configuration, since it contains both mercerized pulp and non-mercelized pulp, it has moderate chemical impregnation and internal bond strength, and has chemical strength impregnation that can withstand the cutting process and chemical impregnation process. A base material can be provided at low cost.

  Moreover, in preferable embodiment of this invention, the Canadian standard freeness (freeness) of the said non mercerized pulp may be 600-750 mlCSF.

  According to such a configuration, the freeness of the non-merceled pulp is also in an appropriate range, so that a chemical solution-impregnated base material that is superior in both chemical solution impregnation property and internal bond strength can be obtained.

  In preferable embodiment of this invention, the compounding ratio of the said mercerized pulp is good also as the range of 30-90 mass% with respect to the pulp whole quantity used for a chemical | medical solution impregnation base material.

  According to such a configuration, since the blending balance of mercerized pulp and non-merceled pulp is in a preferable range, the chemical liquid-impregnated base material is easily bulky and the density is easily adjusted to an appropriate range.

The present invention can also be understood as a manufacturing method. The manufacturing method of the chemical | medical solution impregnation base material which concerns on this invention is the pulp slurry preparation step which mixes the mercerized pulp whose Canadian standard freeness (freeness) is 650-750 mlCSF, and a non-mercelized pulp, and makes it a pulp slurry, , And a papermaking step for making paper using the pulp slurry, wherein the density of the chemical-impregnated base material is 0.30 to 0.38 g / cm ^3, and JAPAN TAPPI No. The internal bond strength measured by 8-2 (paper and paperboard-internal bond strength test method-part 2: internal bond tester method) is 50 mJ or more.

  And according to such a structure, the chemical | medical solution impregnation base material excellent in the balance of chemical | medical solution impregnation property and internal bond strength can be manufactured easily.

  In the manufacturing method of the chemical | medical solution impregnation base material of this invention, it is preferable that the Canadian standard freeness (freeness) of the said non-mercel pulp is 600-750 mlCSF. According to such a configuration, it becomes easier to satisfy the chemical solution impregnation property and the internal bond strength at the same time.

  Moreover, in the manufacturing method of the chemical | medical solution impregnation base material of this invention, it is preferable that each of the said mercerized pulp and the said non-mercelized pulp is beating-processed independently. According to such a configuration, it becomes easy to prepare each pulp to a freeness suitable for the pulp, so that it is easier to satisfy the chemical solution impregnation property and the internal bond strength at the same time.

  ADVANTAGE OF THE INVENTION According to this invention, it becomes possible to provide the chemical | medical solution impregnation base material which has moderate chemical | medical solution impregnation property and internal bond strength, and has the intensity | strength which can endure a cutting process or a chemical | medical solution impregnation process at low cost.

It is explanatory drawing of a chemical | medical solution impregnation rate measurement. It is a graph which shows the mixing | blending and physical property of the chemical | medical solution impregnation base material by an Example and a comparative example.

  Hereinafter, a preferred embodiment of the chemical liquid-impregnated substrate according to the present invention will be described in detail.

As described above, the chemical liquid-impregnated base material according to the present invention is a chemical liquid-impregnated base material containing at least mercerized pulp and non-mercelized pulp, and the mercerized pulp has Canadian standard freeness. Is 650-750 ml CSF, the density is 0.30-0.38 g / cm ³ , and JAPAN TAPPI No. The internal bond strength measured by 18-2 is 50 mJ or more.

  The chemical-impregnated base material according to the present invention contains two or more kinds of cellulose fibers, and as one of them, mercerized pulp obtained by alkali treatment of wood pulp or non-wood pulp is blended. Mercerized pulp is known to evaporate hemicellulose, etc. in pulp fibers, increasing short fiber strength and becoming extremely stiff, and also resulting in mercerization as a result of difficulty in hydrogen bonding between pulp fibers. Paper using pulp becomes bulky and low density paper. Furthermore, even if it is the same density, compared with the base material comprised only with another pulp, a chemical | medical solution impregnation speed | rate becomes easy to become high. The reason for this is not clear, but since mercerized pulp tends to be relatively small in bending and high in linearity, the shape of the gap between the fibers in the base material tends to be a structure suitable for penetration of the chemical solution. It is thought that.

  The pulp for mercerization is not particularly limited, and is representative of softwood bleached kraft pulp (NBKP), softwood bleached sulfite pulp (NBSP), hardwood bleached kraft pulp (LBKP), and hardwood bleached sulfite pulp (LBSP). Wood bleached chemical pulp can be used. Among these, it is preferable to use a mercerized pulp obtained by subjecting softwood bleached kraft pulp (NBKP) to mercerization. When NBKP is used as a raw material, a mercerized pulp with a relatively long fiber length can be obtained. Therefore, various strengths of the base material are likely to be high, bulky and easy to control the density, so that both chemical impregnation and internal bond strength are satisfied at the same time. It becomes easy to let.

  In the present invention, the Canadian standard freeness of mercerized pulp is in the range of 650-750 ml CSF. When the Canadian standard freeness of mercerized pulp is lower than 650 ml CSF, the distance between fibers becomes smaller and the density becomes higher, and as a result, the chemical impregnation rate decreases. On the other hand, when the Canadian standard freeness of mercerized pulp is higher than 750 ml CSF, the entanglement between the fibers is reduced, so that the internal bond strength is lowered and the fibers are also dropped from the chemical-impregnated base material. If the fibers fall off from the chemical-impregnated base material, the surrounding environment is deteriorated in processing steps such as a cutting step and a chemical-solution impregnation step, and foreign matters are mixed into the product.

  As another cellulose fiber used for the chemical | medical solution impregnation base material of this invention, a non-mercel pulp is contained. Here, the non-mercelized pulp is not particularly limited, and may be softwood bleached kraft pulp (NBKP), softwood bleached sulfite pulp (NBSP), hardwood bleached kraft pulp (LBKP), or hardwood bleached sulfite pulp (LBSP). Representative wood bleached chemical pulp, GP (ground wood pulp), TMP (thermomechanical pulp), BCTMP (bleached chemithermomechanical pulp) and other mechanical pulp, waste paper pulp, wood pulp other than wood pulp, three bases, husk, hemp, bagasse Non-wood pulp, such as kenaf, bamboo, cotton linter, etc. can be used. As the non-mercelized pulp of the present invention, one or more kinds of general pulps as described above can be appropriately selected and used. Among these, it is preferable to use softwood bleached kraft pulp (NBKP). Since NBKP has a relatively long fiber length and high strength, it can be expected to maintain the internal bond strength while maintaining the bulkiness of the base material by blending it with mercerized pulp.

  Although the freeness of the non-mercel pulp used in the present invention is not particularly limited, it is 600 to 600 in Canadian standard freeness (freeness) (JIS P 8121: 1995 “Pulp Freeness Test Method”). It is preferable to be in the range of 750 ml CSF. By setting the freeness within this range, it becomes easy to obtain an appropriate chemical solution impregnation property and internal bond strength, and it is easy to obtain paper quality suitable for the chemical solution impregnated substrate. When the Canadian standard freeness of the non-mercel pulp is higher than 750 ml, the entanglement between the fibers decreases, so that the internal bond strength tends to decrease, and the fibers are likely to fall off. On the other hand, if the Canadian standard freeness of the non-mercel pulp is lower than 600 ml, the density of the base material tends to increase, and the chemical solution impregnation rate may be lowered.

  In the present invention, the pulp beating method is not particularly limited, and any beating machine such as a beater, a Jordan, a deluxe finer, or a double disc refiner may be used alone or in combination. As the pulp is beaten, the fiber length is shortened and fibrillated and the freeness is lowered, so that the inter-fiber bond between the pulps becomes stronger and the internal bond strength of the base material is increased, but the density is also high. Become. On the contrary, if the degree of beating is small, the fiber length remains naturally long and the fibrillation is small, so that the internal bond strength of the base material is low and the density is low, so that the base material becomes bulky.

  In the present invention, at least two kinds of pulps, mercerized pulp and non-merceled pulp, are used, so two procedures for beating the pulp are conceivable. That is, beating after mixing mercerized pulp and non-merceled pulp in advance (hereinafter sometimes referred to as “mixed beating”), or beating each pulp alone (hereinafter referred to as “single beating”) Or after mixing). In general, when two or more kinds of pulp are mixed to obtain a papermaking raw material, mixed beating is often used because of good beating efficiency, water saving, and energy efficiency. However, when pulps with different beating resistance are mixed and beaten, pulp with low beating resistance is preferentially beaten, so pulp with high beating resistance tends to be insufficiently beaten, There is a case where the drainage cannot be made and the performance of the pulp cannot be sufficiently obtained. For this reason, in the present invention, it is preferable to beat each of the mercerized pulp and the non-merceled pulp. By beating each pulp independently, it becomes easy to adjust the freeness of each pulp, and the beating for extracting the target performance is sufficiently added.

  In the present invention, the content ratio of mercerized pulp in the chemical liquid-impregnated base material is preferably 30 to 90% by mass and more preferably 40 to 80% by mass with respect to the total amount of pulp in the chemical liquid-impregnated base material. By setting it as such a mixture ratio, it becomes easy to make it a bulky base material and to adjust to an appropriate density.

In chemical-impregnated base material of the present invention, a density in the range of 0.30~0.38g / cm ^3, preferably in the range of 0.32~0.36g / cm ^3. If the density is less than 0.30 g / cm ³ , sufficient strength to withstand the cutting process and the chemical liquid impregnation process cannot be obtained, and conversely if the density is higher than 0.38 g / cm ³ , sufficient voids for chemical liquid impregnation are obtained. It is difficult to obtain an appropriate chemical solution impregnation rate. In the present invention, the density control method is not particularly limited, but can be controlled by the freeness of each pulp and the blending ratio of mercerized pulp. The higher the freeness of the pulp used and the greater the blending ratio of mercerized pulp, the lower the density.

  In the present invention, the JAPAN TAPPI No. The internal bond strength measured by 18-2 (paper and paperboard-internal bond strength test method-part 2: internal bond tester method) is 50 mJ or more, preferably 60 mJ or more, more preferably 70 mJ or more. . If the internal bond strength is less than 50 mJ, the chemical solution-impregnated base material cannot withstand the processing steps such as the cutting step and the chemical solution impregnation step, which may cause trouble such as end turning. Further, if the fibers fall off from the chemical-impregnated base material, the surrounding environment is deteriorated in each process, and foreign substances are mixed into the product.

  As described above, the chemical liquid-impregnated base material of the present invention can be obtained by mixing mercerized pulp and non-mercelized pulp to form a pulp slurry, and making paper using the pulp slurry. The pulp slurry contains various papermaking materials such as sulfuric acid bands, fillers, sizing agents, paper strength agents, yield improvers, coloring dyes, coloring pigments, etc., as long as the intended effect of the present invention is not impaired. Can do. As the filler, one or more known fillers such as hydrated silicic acid, white carbon, talc, kaolin, clay, calcium carbonate, titanium oxide, aluminosilicate, calcined clay, barium sulfate, and synthetic resin filler can be used. .

  When using sizing agent, paraffin wax sizing agent, microcrystalline wax sizing agent, carnauba (carnauba wax) sizing agent, alkyl ketene dimer wax sizing agent, rosin sizing agent, alkenyl succinic anhydride size One or more kinds of agents can be used. However, application of a sizing agent is not preferred when used for applications in which a base material is impregnated with an aqueous chemical solution.

  Examples of paper strength agents include starch, cationized starch, other modified starches, polyacrylamide resins, urea formalin resins, melamine formalin resins, plant gums, polyvinyl alcohol, modified polyvinyl alcohol, rubber latex, polyethylene oxide, polyamide resins, etc. In addition to those that promote the improvement of paper strength, one or more types that promote the improvement of wet paper strength, such as polyamide epichlorohydrin epoxy resin, can be used. The paper strength agent is effective in improving the internal bond strength, but if the amount added is too large, the density may increase. In this invention, it is preferable that the addition amount in the case of adding a paper strength agent in a pulp slurry is the range of 0.1-5 mass% with respect to the pulp whole quantity, More preferably, it is 0.3-4 mass%. More preferably, it is the range of 0.35 to 2 mass%. When the addition amount of the paper strength agent exceeds 5% by mass, the bonding between the fibers becomes stronger, but the density increases, and the excess paper strength enhancer itself enters the gap between the fibers to reduce the gap. It is difficult to obtain a high chemical impregnation rate. Furthermore, if the paper strength enhancer that cannot be fixed to the fibers increases, the suspended paper strength enhancer leads to troubles that contaminate the process.

  In the present invention, the papermaking method of the chemical-impregnated base material is not particularly limited, and a conventionally well-known paper machine such as a circular net paper machine, a short net paper machine, a long net paper machine, or a combination paper machine of these paper machines can be used. It can be used to make paper in a single layer or in paper making. In the case of papermaking, a paper strength agent such as starch for interlayer may be sprayed to prevent delamination of each layer of papermaking.

  In the present invention, various papermaking materials such as a paper strength agent, a sizing agent, and a surfactant can be added to the surface of the paper with a size press within a range that does not impair the intended effect of the present invention. The addition of an appropriate paper strength agent is effective in improving the surface strength and interlayer strength, and the addition of an appropriate surfactant improves the chemical solution impregnation property.

  Next, although an example and a comparative example are given and the present invention is explained more concretely, the present invention is not limited to these examples. Further, “parts” and “%” in the examples respectively represent parts by mass or mass% in terms of solid content unless otherwise specified. Moreover, about a sulfuric acid band, the solid content part as aluminum sulfate 16 hydrate is shown.

Example 1
50 parts of a 750 ml CSF mercerized pulp with a freeness before beating of 775 ml CSF (trade name “POROSANIEA”, manufactured by Rayonier, NBKP) was beaten alone in 740 ml CSF, and NBKP with a freeness before beating of 750 ml CSF was beaten alone in a 730 ml CSF. 1 part of sulfuric acid band (manufactured by Techno Hokuetsu) and 0.39 part of polyamide epichlorohydrin (WS-4020, manufactured by Seiko PMC) are added to the pulp slurry. After the paper stock was obtained, the stock was made by single layer paper making and dried to obtain a chemical-impregnated base material having a basis weight of 150 g / m ² .

(Example 2)
In Example 1, a chemical-impregnated base material was obtained in the same manner as in Example 1 except that the number of parts of mercerized pulp beaten alone was 75 parts and the number of parts of non-merceled pulp (NBKP) beaten alone was 25 parts. .

(Example 3)
In Example 2, the chemical-impregnated base material was the same as in Example 2 except that the freeness after beating of the mercerized pulp beaten alone was 663 ml CSF, and the freeness after beating of the non-merceled pulp (NBKP) beaten alone was changed to 675 mlCSF. Got.

Example 4
Mercerized pulp with a freeness before beating of 775 ml CSF (trade name “POROSANIEA”, manufactured by Rayonier, NBKP) 50 parts of 663 ml CSF alone, and 630 ml CSF of cotton linter pulp with a freeness before beating of 770 ml CSF as non-mercelled pulp 50 parts of a single beating was dispersed in water to obtain a pulp slurry, and 1 part of a sulfuric acid band (manufactured by Techno Hokuetsu) and 0.39 part of polyamide epichlorohydrin (WS-4020, manufactured by Starlight PMC) were added to the pulp slurry. After each was added to obtain a paper material, the paper material was made into a single layer and then paper-dried to obtain a chemical-impregnated base material having a basis weight of 150 g / m ² .

(Example 5)
In Example 2, a chemical-impregnated base material was obtained in the same manner as in Example 2 except that the freeness after beating of the mercerized pulp beaten alone was changed to 663 ml CSF.

(Comparative Example 1)
In Example 1, 50 parts of mercerized pulp with a freeness before beating of 775 ml CSF and 50 parts of non-mercelized pulp (NBKP) with a freeness before beating of 750 ml CSF were mixed and beaten and dispersed in water to obtain a pulp slurry. Obtained a chemical-impregnated base material in the same manner as in Example 1. At this time, the freeness of the pulp obtained after beating was 750 ml CSF.

(Comparative Example 2)
In Example 2, 75 parts of mercerized pulp with a freeness before beating of 775 ml CSF and 25 parts of non-mercelized pulp (NBKP) with a freeness before beating of 750 ml CSF were mixed and beaten and dispersed in water to obtain a pulp slurry. Obtained a chemical-impregnated base material in the same manner as in Example 2. At this time, the freeness of the pulp obtained after beating was 745 ml CSF.

(Comparative Example 3)
A base impregnated with a chemical solution in the same manner as in Example 2, except that the freeness after beating of the mercerized pulp beaten alone was 580 ml CSF and the freeness after beating of the non-merceled pulp (NBKP) beaten alone was changed to 580 mlCSF. Got.

(Comparative Example 4)
In Example 2, instead of mercerized pulp, a chemical-impregnated base material was used in the same manner as in Example 2 except that cotton linter pulp having a freeness before beating of 770 ml CSF, which was non-merceled pulp, was changed to a single beat of 740 ml CSF. Got.

(Comparative Example 5)
In Example 1, a chemical liquid-impregnated base material was obtained in the same manner as in Example 1 except that the blended part of the mercerized pulp beaten alone was 100 parts and the non-mercelized pulp (NBKP) was not blended.

(Comparative Example 6)
In Example 3, a chemical solution-impregnated base material was obtained in the same manner as in Example 3 except that the blended number of mercerized pulp beaten alone was 100 parts and non-mercelized pulp (NBKP) was not blended.

(Comparative Example 7)
In Example 1, the chemical | medical solution impregnation base material was obtained like Example 1 except the freeness after beating of mercerized pulp having been 760 mlCSF.

(Comparative Example 8)
In Example 2, a chemical-impregnated base material was obtained in the same manner as in Example 2 except that the freeness after beating the mercerized pulp was changed to 580 ml CSF.

(Comparative Example 9)
In Example 1, a chemical-impregnated base material was obtained in the same manner as in Example 1, except that the number of parts of mercerized pulp beaten alone was 25 parts and the number of parts of non-merceled pulp (NBKP) beaten alone was 75 parts. .

  FIG. 2 shows the outline of the stock composition in each example and comparative example, and the evaluation results of the obtained chemical-impregnated base material. Each physical property was evaluated by the following methods.

<Internal bond strength (internal bond)>
JAPAN TAPPI No. In accordance with 18-2 (paper and paperboard-internal bond strength test method-part 2: internal bond tester method), internal bond strength (mJ ) Was measured. The measurement direction was the CD direction (lateral direction) of the paper.

<Chemical solution impregnation speed>
The measurement of the chemical solution impregnation rate will be described with reference to FIG. Each chemical-impregnated base material obtained in the examples and comparative examples was cut into a test piece 1 having a width of 4 cm and a length of 3 cm, and the measurement surface was up, the diameter was 3.5 cm, the thickness was 1 mm, and the height was 1 cm. It is placed on a ring-shaped plastic support 3. To the center of the test piece 1 placed on the support 3, 0.1 ml of texanol (trade name: CS-12 / manufactured by JNC) as a test chemical solution was dropped from a height of 1 cm above the paper surface by natural dropping, The time until the chemical solution completely penetrates into the paper without remaining on the surface of the chemical-impregnated base material was measured and evaluated as the chemical solution impregnation rate. A chemical solution impregnation rate within 18 seconds has a preferable chemical solution impregnation rate.

  In addition, as described above, in the chemical liquid impregnated base material according to the present application, one of the purposes is to provide an appropriate chemical liquid impregnation property, that is, an appropriate chemical liquid impregnation speed and a chemical liquid retention amount. According to the above, since the performance of the chemical solution holding amount is sufficient with respect to the required performance, the chemical solution holding amount is not evaluated in this example.

<Fiber dropout>
The fiber dropout during the measurement of the internal bond strength and the impregnation time was observed and evaluated in four stages.
(Double-circle): There is almost no dropout of a fiber. Pass.
○: Slight fiber dropout is observed. Pass.
(Triangle | delta): The fall of a fiber is seen considerably. failure.
X: Dropping of fibers is very often observed. failure.

  As is clear from FIG. 2, the chemical liquid impregnated substrates obtained in Examples 1 to 5 have an appropriate chemical liquid impregnation rate and internal bond strength, and have an internal bond strength that can withstand the cutting process and the chemical liquid impregnation process. doing.

  On the other hand, the chemical liquid impregnated base material obtained in Comparative Example 1 had a low chemical liquid impregnation rate and was inferior to the chemical liquid impregnation rate. Moreover, the chemical | medical solution impregnation base material obtained by the comparative example 2 was inferior to internal bond strength. The basic configurations of these comparative examples are the same as those of the first and second embodiments, and only the difference between the single beating method and the mixed beating method is the difference from the first and second embodiments. From this, it is considered that the problem of the chemical-impregnated base materials obtained in Comparative Examples 1 and 2 is that the beating of the mercerized pulp did not sufficiently proceed due to the mixing beating.

  Next, the chemical liquid-impregnated base materials obtained in Comparative Example 3 and Comparative Example 8 were both unacceptable because of their slow chemical impregnation speed. This is considered that the Canadian standard freeness of mercerized pulp was lower than 650 ml, and the chemical impregnation base was too high, and the chemical impregnation rate was slowed.

  Moreover, the chemical | medical solution impregnation base material obtained by the comparative example 4 was inferior to internal bond strength and penetration time. This is because cotton linter pulp was used instead of mercerized pulp, and in the case of the same degree of freeness, cotton linter pulp is weaker than mercerized pulp and may not be bulky. The reason is considered.

  Next, the chemical-impregnated base materials obtained in Comparative Example 5 and Comparative Example 6 were both unacceptable in that there were many fibers falling off. From this, it is considered that when only mercerized pulp is used as the pulp, the fibers are likely to fall off.

  The chemical solution-impregnated base material obtained in Comparative Example 7 was unacceptable due to a large amount of fiber dropping. This is due to the lack of beating of the mercerized pulp and the Canadian standard freeness (freeness) being higher than 750 ml, and because the entanglement with other pulp was weak, the fibers were likely to fall off. it is conceivable that.

  The chemical liquid-impregnated base material obtained in Comparative Example 9 was too high in density, so that the permeation time was long and the chemical liquid impregnation rate was inferior.

1 Test piece (chemical solution impregnated base material)
2 Chemical solution impregnation part 3 Support

Claims (6)

A chemical-impregnated base material containing at least mercerized pulp and non-mercelized pulp,
The mercerized pulp has a Canadian freeness of 650-750 ml CSF,
The density is 0.30 to 0.38 g / cm ³ , and JAPAN TAPPI No. A chemical-impregnated base material having an internal bond strength of 50 mJ or more measured by 18-2 (paper and paperboard-internal bond strength test method-part 2: internal bond tester method).   The chemical-impregnated base material according to claim 1, wherein the non-mercelized pulp has a Canadian standard freeness (freeness) of 600 to 750 ml CSF.   2. The chemical-impregnated base material according to claim 1, wherein a blending ratio of the mercerized pulp is in a range of 30 to 90 mass% with respect to a total amount of pulp used for the chemical-impregnated base material. A pulp slurry preparation step in which a mercerized pulp having a Canadian standard freeness (freeness) of 650 to 750 ml CSF and a non-merceled pulp are mixed to form a pulp slurry;
A process for producing a chemical-impregnated substrate having a paper making step of making paper using the pulp slurry,
The density of the chemical-impregnated base material is 0.30 to 0.38 g / cm ³ , and JAPAN TAPPI No. A method for producing a chemical-impregnated base material, characterized in that the internal bond strength measured by 18-2 (paper and paperboard-internal bond strength test method-part 2: internal bond tester method) is 50 mJ or more.   The method for producing a chemical-impregnated base material according to claim 4, wherein the non-mercelized pulp has a Canadian standard freeness (freeness) of 600 to 750 ml CSF.   The method for producing a chemical-impregnated base material according to claim 4 or 5, wherein the mercerized pulp and the non-mercelized pulp are each beaten independently.

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