JP6762901B2 - Chemical impregnated base material and its manufacturing method - Google Patents

Description

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

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

As a technique relating to the period indicator, for example, in Patent Document 1, a substrate material made of a chemical liquid permeable material and a material having a chemical liquid permeability partially laminated on the surface of the substrate material and having a low refractive index with respect to light are used. A chemical solution-containing indicator has been proposed, which comprises a structure in which a room-temperature volatilizing agent is contained in a sheet material including a display unit. Further, Patent Document 2 includes a base material having liquid permeability and a display portion at the end of the period made of a material having a liquid permeability and a low refractive index with respect to light partially laminated on the base material, and volatilizes. Among the period indicators containing a sexual liquid, a period indicator in which a display portion at the beginning of the period consisting of a liquid-impermeable and gas-permeable region is formed has been proposed.

In addition to the above-mentioned period indicator function, the suitability required for the chemical solution impregnated base material includes the chemical solution impregnation rate, the chemical solution retention amount, the internal bond strength that can withstand the cutting process and the chemical solution impregnation process, and the like. In the following, 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 property".

Next, in Patent Document 3, a surface layer, a middle layer composed of one layer or a plurality of layers, and a back layer of a multi-layered impregnated paper, wherein at least one of the back layer or the middle layer is a liquid absorbing layer, and the liquid absorbing layer is It is shown that 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 pulp type rag is 20 to 80%, and cotton linter pulp is used as such non-wood fibers. Further, the dissociation freeness is 600 to 700 cc, the Krem water absorption (vertical) is 80 to 100 mm, and the density is 0.40 to 0.60 g / cm ³ . Further, an indicator mount in which a coating layer containing at least silica is formed on the surface layer surface of the impregnated paper has also been proposed.

Patent Document 4 includes an impregnated paper composed of a surface layer, a middle layer composed of one layer or a plurality of layers, and a back layer, and an indicator mount composed of a coating layer formed on the surface of the surface layer of the impregnated paper. In the impregnated paper, non-wood fibers are blended so that the blending ratio of the pulp type rag is 20 to 80%, the surface layer is a colored layer, the back layer and the middle layer are a liquid absorbing layer, and the impregnated paper is 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 having an average particle size of 3 to 8 μm as a pigment as a binder. A vinyl acetate-based resin, which contains toluene as a solvent and has a peel strength of 0.35 to 1.10 MPa, has been proposed.

Further, in Patent Document 5, a chemical-impregnated base material in which a second layer composed of cellulose fibers and synthetic fibers is laminated between two layers mainly composed of cellulose fibers, the first layer and the third layer, is a second layer. The blending ratio of the cellulose fiber and the synthetic fiber is 20 to 80: 80 to 20% by weight, the cellulose fiber contains at least 50% by weight or more of marcelled pulp or cotton linter pulp, and the synthetic fiber is the main fiber and the binder fiber. The composition 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. It has been proposed that the base material impregnated with the chemical solution has a basis weight of 75 to 500 g / m ² and a density of 0.25 to 0.50 g / cm ³ .

As described above, various proposals have been made to improve the chemical impregnation property and the peel strength of the chemical impregnated substrate. The "improvement of chemical impregnation property" referred to here includes an improvement in the chemical solution impregnation rate and an increase in the 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 speed is also shortened and the manufacturing process as a whole is shortened. Further, when the amount of chemical solution retained is increased, there is an advantage that the product can be miniaturized because the required amount of chemical solution can be retained in a smaller area. In order to improve such chemical impregnation property, in Patent Documents 3 and 4, cotton linter pulp is blended in the absorption layer to set the disintegration freeness to 600 to 700 cc, and in Patent Document 5, the second layer The blending 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 or more of mercerized pulp or cotton linter pulp.

However, if a high amount of mercerized pulp or cotton linter pulp is added, the chemical impregnation rate is improved, but on the other hand, the peeling strength is lowered, so that there is a high possibility that troubles such as the cut end being turned over during cutting are increased. is there. Regarding this point, in Patent Document 5, an expensive binder fiber is blended as a measure against a decrease in peel strength, and it is possible to obtain strength that can withstand processing steps such as a cutting step and a chemical solution impregnation step while maintaining high chemical impregnation property. Needed expensive raw materials.

Real Fairness 05-000938 Gazette Japanese Patent No. 4336650 Japanese Unexamined Patent Publication No. 2010-08427 JP-A-2010-197815 Japanese Unexamined Patent Publication No. 2015-193954

The present invention has been made in view of such problems, and an object of the present invention is a chemical solution having an appropriate chemical impregnation property and internal bond strength, and having a strength capable of withstanding a cutting step and a chemical solution impregnation step. The purpose is to provide an impregnated base material at a low cost.

Other objects of the present invention as well as actions and effects will be readily understood by those skilled in the art by reference to the following description.

The chemical-impregnated base material of the present invention is a chemical-impregnated base material containing at least a mercerized pulp and a non-mercerized pulp, and the mercerized pulp has a Canadian standard drainage (freeness) of 650 to 750 ml CSF. , The density is 0.30 to 0.38 g / cm ³ , and Japan TAPPI No. It is 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.

According to such a configuration, since it contains both mercerized pulp and non-mercerized pulp, it has an appropriate chemical impregnation property and internal bond strength, and is strong enough to withstand a cutting step and a chemical impregnation step. The base material can be provided at low cost.

Further, in a preferred embodiment of the present invention, the Canadian standard drainage (freeness) of the non-mercerized pulp may be 600 to 750 ml CSF.

According to such a configuration, the degree of drainage of the non-mercerized pulp is within an appropriate range, so that a chemical-impregnated base material having both excellent chemical-impregnated property and internal bond strength can be obtained.

In a preferred embodiment of the present invention, the blending ratio of the mercerized pulp may be in the range of 30 to 90% by mass with respect to the total amount of pulp used for the chemical-impregnated base material.

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

Further, the present invention can also be regarded as a manufacturing method of. The method for producing a chemical-impregnated base material according to the present invention includes a pulp slurry preparation step in which marcelled pulp having a Canadian standard drainage (freeness) of 650 to 750 ml CSF and non-mercelled pulp are mixed to form a pulp slurry. A method for producing a chemical-impregnated base material, which comprises a papermaking step of 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. It is characterized in that 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.

According to such a configuration, a chemical-impregnated base material having an excellent balance between the chemical-impregnated property and the internal bond strength can be easily produced.

In the method for producing a chemical-impregnated substrate of the present invention, it is preferable that the non-mercerized pulp has a Canadian standard drainage (freeness) of 600 to 750 ml CSF. According to such a configuration, it becomes easier to satisfy the chemical impregnation property and the internal bond strength at the same time.

Further, in the method for producing a chemical-impregnated base material of the present invention, it is preferable that the mercerized pulp and the non-mercerized pulp are individually beaten. According to such a configuration, it becomes easy to prepare each pulp with a drainage degree suitable for the pulp, so that it becomes easier to satisfy both the chemical impregnation property and the internal bond strength at the same time.

According to the present invention, it is possible to inexpensively provide a chemical-impregnated base material having an appropriate chemical-impregnated property and internal bond strength and having a strength capable of withstanding a cutting step or a chemical-impregnated step.

It is explanatory drawing of the chemical | chemical impregnation rate measurement. It is a figure which shows the composition and the physical property of the chemical | chemical impregnated base material by Example and comparative example.

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

As described above, the chemical-impregnated base material according to the present invention is a chemical-impregnated base material containing at least mercerized pulp and non-mercerized pulp, and the mercerized pulp has a Canadian standard drainage degree. Is 650 to 750 ml CSF, the density is 0.30 to 0.38 g / cm ³ , and Japan TAPPI No. It has a configuration in which 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 types of cellulose fibers, and as one of them, mercerized pulp obtained by alkali-treating wood pulp or non-wood pulp is blended. It is known that hemicellulose and the like in pulp fibers are eluted from the mercellized pulp to increase the strength of short fibers and become extremely rigid, and as a result, hydrogen bonding between pulp fibers becomes difficult, resulting in mercellization. Paper made from pulp is bulky and has a low density. Further, even if the density is the same, the chemical impregnation rate tends to be higher than that of a base material composed only of other pulp. The reason for this is not clear, but since mercerized pulp tends to have relatively small bending and high linearity, the shape of the gap between the fibers in the base material tends to be a structure suitable for permeation of the chemical solution. I think it might be.

The pulp to be subjected to the marcel treatment is not particularly limited, and is represented by softwood bleached kraft pulp (NBKP), softwood bleached sulphite pulp (NBSP), broadleaf bleached kraft pulp (LBKP), and hardwood bleached sulphite pulp (LBSP). Wood bleached chemical pulp to be used can be used. Among these, it is preferable to use softwood bleached kraft pulp (NBKP) that has been mercerized to obtain mercerized pulp. When NBKP is used as a raw material, mercerized pulp having a relatively long fiber length can be obtained, so that various strengths of the base material tend to be high, and the bulkiness and density can be easily controlled. Therefore, the chemical impregnation property and the internal bond strength are satisfied at the same time. It becomes easy to make it.

In the present invention, the Canadian standard freeness of mercerized pulp is in the range of 650 to 750 ml CSF. When the Canadian standard drainage of mercerized pulp is lower than 650 ml CSF, the distance between the fibers is reduced, resulting in higher density and, as a result, lower chemical impregnation rate. On the other hand, when the Canadian standard drainage degree of the 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 removed from the chemical-impregnated substrate. If the fibers fall off from the chemical-impregnated base material, the surrounding environment is deteriorated in the processing process such as the cutting process and the chemical-impregnated process, and foreign substances may be mixed into the product, which is not preferable.

As another cellulose fiber used for the chemical-impregnated base material of the present invention, non-mercerized pulp is contained. Here, the non-mercelled pulp is not particularly limited, and includes coniferous bleached kraft pulp (NBKP), coniferous bleached sulphite pulp (NBSP), broadleaf bleached kraft pulp (LBKP), and broadleaf bleached sulphite pulp (LBSP). Typical wood bleaching chemical pulp, GP (crushed wood pulp), TMP (thermomechanical pulp), BCTMP (bleached chemothermomechanical pulp) and other mechanical pulp, used paper pulp, 楮 other than wood pulp, sardine, bark, hemp, bagas , Kenaf, bamboo, non-wood pulp such as cotton linter, etc. can be used. As the non-mercerized pulp of the present invention, one or more of the above-mentioned general pulps can be appropriately selected and used, and among these, softwood bleached kraft pulp (NBKP) is preferably used. Since NBKP has a relatively long fiber length and high strength, it is expected that the internal bond strength can be maintained while maintaining the bulkiness of the base material by blending with the mercerized pulp.

The drainage degree of the non-mercerized pulp used in the present invention is not particularly limited, but is 600 to 600 in the Canadian standard drainage degree (freeness) (JIS P 8121: 1995 "Pulp freshness test method"). It is preferably in the range of 750 ml CSF. By setting the degree of drainage within this range, it becomes easy to obtain an appropriate chemical impregnation property and internal bond strength, and it is easy to obtain a paper quality suitable for the chemical solution impregnated base material. When the Canadian standard drainage degree of non-mercerized pulp is higher than 750 ml, the entanglement between fibers is reduced, 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 drainage degree of the non-mercerized pulp is lower than 600 ml, the density of the base material tends to be high, and the chemical impregnation rate may decrease.

In the present invention, the beating method of pulp is not particularly limited, and any beating machine such as beater, Jordan, deluxe finer, double disc refiner, etc. may be used alone or in combination. As the beating of pulp progresses, the fiber length becomes shorter and the pulp becomes fibrillated to lower the degree of drainage.Therefore, the stronger the interfiber bond between the pulps increases the internal bond strength of the base material, but the density is also high. Become. On the contrary, if the degree of beating is small, the fiber length naturally remains 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 types of pulp, mercerized pulp and non-mercerized pulp, are used, and therefore, two procedures for beating the pulp can be considered. That is, either the mercerized pulp and the non-mercerized pulp are mixed in advance and then beaten (hereinafter, may be referred to as "mixed beat"), or each pulp is beaten independently (hereinafter, referred to as "single beat"). There are two, either after mixing). Generally, when two or more types of pulp are mixed and used as a raw material for papermaking, mixed beating is often used because of its good beating efficiency, water saving and energy efficiency. However, when pulps with different beating resistances are mixed and beaten, pulps with low beating resistance are preferentially beaten, so pulps with high beating resistance tend to be insufficiently beaten, and the originally targeted pulps of each pulp It may not be possible to obtain sufficient drainage and the performance of pulp may not be fully obtained. Therefore, in the present invention, it is preferable to beat the mercerized pulp and the non-mercerized pulp individually. By beating each pulp individually, it becomes easy to adjust the freeness of each pulp, and sufficient beating is added to bring out the desired performance.

In the present invention, the content ratio of the mercerized pulp in the chemical-impregnated base material is preferably 30 to 90% by mass, more preferably 40 to 80% by mass, based on the total amount of pulp in the chemical-impregnated base material. With such a blending ratio, it becomes easy to make a bulky base material and adjust the density to an appropriate level.

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 step and the chemical impregnation step cannot be obtained, and conversely, if the density is higher than 0.38 g / cm ³ , sufficient voids for chemical impregnation are obtained. It is difficult to obtain an appropriate chemical impregnation rate. In the present invention, the density control method is not particularly limited, but it can be controlled by the freeness of each pulp and the blending ratio of the mercerized pulp. The higher the freeness of the pulp used and the higher the blending ratio of the mercerized pulp, the lower the density tends to be.

In the present invention, 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, and more preferably 70 mJ or more. .. If the internal bond strength is less than 50 mJ, the chemical-impregnated base material cannot withstand the processing steps such as the cutting process and the chemical-impregnated step, and there is a risk of problems such as end face turning. In addition, if the fibers fall off from the chemical-impregnated base material, the surrounding environment is deteriorated in each process, and foreign substances may be mixed into the product.

The chemical-impregnated base material of the present invention can be obtained by mixing mercerized pulp and non-mercerized pulp to form a pulp slurry as described above, and making paper using the pulp slurry. The pulp slurry shall contain various paper-making materials such as sulfuric acid bands, fillers, sizing agents, paper strength agents, yield improvers, coloring dyes, coloring pigments, etc., as long as the effects intended by the present invention are not impaired. Can be done. 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 a sizing agent, a paraffin wax sizing agent, a microcrystalline wax sizing agent, a carnauba (carnauba wax) sizing agent, an alkyl keten dimer wax sizing agent, a rosin sizing agent, and an alkenyl succinic anhydride size agent. One or more of the agents and the like can be used. However, when the substrate is used for impregnating an aqueous chemical solution, the application of a sizing agent is not preferable.

Paper strength agents include starch, cationized starch, other modified starch, polyacrylamide resin, urea formalin resin, melamine formalin resin, vegetable gum, polyvinyl alcohol, modified polyvinyl alcohol, rubber latex, polyethylene oxide, polyamide resin, etc. In addition to those that promote the improvement of paper strength, one or more kinds that promote the improvement of wet paper strength, such as polyamide epichlorohydrin-based epoxy resin, can be used. Paper strength agents are effective in improving the internal bond strength, but if the amount added is too large, the density may increase. In the present invention, the amount of the paper strength agent added to the pulp slurry is preferably in the range of 0.1 to 5% by mass, more preferably 0.3 to 4% by mass, based on the total amount of pulp. It is in the range of 0.35 to 2% by mass, more preferably 0.35 to 2% by mass. When the amount of the paper strength agent added exceeds 5% by mass, the bonds between the fibers become stronger, but as the density increases, the excess paper strength agent itself enters the gaps between the fibers and the gaps are reduced. It becomes difficult to obtain a high chemical impregnation rate. Furthermore, if the amount of paper strength enhancer that cannot be fixed to the fiber increases, the floating paper strength enhancer leads to troubles that stain the process.

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

In the present invention, various paper-making materials such as a paper strength agent, a sizing agent, and a surfactant can be contained on the surface of the paper by a size press within a range that does not impair the effect intended by the present invention. Addition of an appropriate amount of paper strength agent is effective in improving surface strength and interlayer strength, and addition of an appropriate amount of surfactant improves chemical impregnation property.

Next, the present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited to these examples. In addition, "parts" and "%" in the example indicate mass parts or mass% in terms of solid content, respectively, unless otherwise specified. For the sulfate band, the number of solids as aluminum sulfate hexahydrate is shown.

(Example 1)
50 parts of Marcelized pulp (trade name "POROSANIEA", manufactured by RAYONIER, NBKP) with 775 ml CSF before beating and beaten alone to 740 ml CSF, and NBKP with 750 ml CSF before beaten as non-mercelled pulp alone to 730 ml CSF. 50 parts of the paper was dispersed in water to make a pulp slurry, and 1 part of sulfuric acid band (manufactured by Techno Hokuetsu) and 0.39 parts of polyamide epichlorohydrin (WS-4020, manufactured by Seikou PMC) were added to the pulp slurry. After obtaining the paper material, the paper material was made by one-layer papermaking 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 the mercerized pulp beaten alone was 75 and the number of parts of the non-mercerized pulp (NBKP) beaten alone was 25. ..

(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 which was beaten alone was 663 ml CSF and the freeness after beating of the non-mercerized pulp (NBKP) which was beaten alone was 675 ml CSF part. Got

(Example 4)
50 parts of mercerized pulp with 775 ml CSF before beating (trade name "POROSANIEA", manufactured by RAYONIER, NBKP) alone beaten to 663 ml CSF, and cotton linter pulp with 770 ml CSF before beating as non-mercerized pulp to 630 ml CSF. 50 parts of the single beaten material were dispersed in water to form a pulp slurry, and 1 part of a sulfuric acid band (manufactured by Techno Hokuetsu) and 0.39 parts of polyamide epichlorohydrin (manufactured by WS-4020, manufactured by Seikou PMC) were added to the pulp slurry. After each was added to obtain a paper material, the paper material was made by one-layer papermaking and 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 which was beaten alone was set to 663 ml CSF.

(Comparative Example 1)
In Example 1, 50 parts of mercerized pulp having a pre-beating freeness of 775 ml CSF and 50 parts of non-mercerized pulp (NBKP) having a pre-beating freeness of 750 ml CSF were mixed and then beaten and dispersed in water to form a pulp slurry. Obtained a chemical-impregnated substrate 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 having a pre-beating freeness of 775 ml CSF and 25 parts of non-mercerized pulp (NBKP) having a pre-beating freeness of 750 ml CSF were mixed and then beaten, and dispersed in water to form a pulp slurry. Obtained a chemical-impregnated substrate 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)
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 which was beaten alone was 580 ml CSF and the freeness after beating of the non-mercerized pulp (NBKP) which was beaten alone was 580 ml CSF. Got

(Comparative Example 4)
In Example 2, the chemical-impregnated base material was changed to a non-mercerized pulp in which cotton linter pulp having a pre-beating freeness of 770 ml CSF was beaten alone to 740 ml CSF in the same manner as in Example 2. Got

(Comparative Example 5)
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 the mercerized pulp beaten alone was 100 and the non-mercerized pulp (NBKP) was not mixed.

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

(Comparative Example 7)
In Example 1, a chemical-impregnated base material was obtained in the same manner as in Example 1 except that the freeness after beating of the mercerized pulp was set to 760 ml CSF.

(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 of the mercerized pulp was set 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 the independently beaten mercerized pulp was 25 and the number of parts of the independently beaten non-mercerized pulp (NBKP) was 75. ..

FIG. 2 shows an outline of the paper material composition in each Example and Comparative Example and the evaluation result of the obtained chemical solution-impregnated base material. The evaluation of each physical property was carried out by the following methods.

<Internal bond strength (internal bond)>
JAPAN TAPPI No. Internal bond strength (mJ) of the chemical-impregnated substrate obtained in each Example and Comparative Example in accordance with 18-2 (Paper and Paperboard-Internal Bond Strength Test Method-Part 2: Internal Bond Tester Method) ) Was measured. The measurement direction was the CD direction (horizontal direction) of the paper.

<Chemical impregnation rate>
The measurement of the chemical impregnation rate will be described with reference to FIG. Each chemical-impregnated base material obtained in Examples and Comparative Examples was cut into a width of 4 cm and a length of 3 cm to obtain a test piece 1, and the measurement surface was facing up, and the diameter was 3.5 cm, the thickness was 1 mm, and the height was 1 cm. Place it on the ring-shaped plastic support 3. 0.1 ml of texanol (trade name: CS-12 / manufactured by JNC Corporation) as a chemical solution for testing was dropped onto the center of the test piece 1 placed on the support 3 from a height of 1 cm above the paper surface by free fall. The time required for the chemical solution to completely penetrate into the paper without remaining on the surface of the chemical solution impregnated substrate was measured and evaluated as the chemical solution impregnation rate. Those having a chemical impregnation rate of 18 seconds or less have a preferable chemical impregnation rate.

As described above, one of the purposes of the chemical solution-impregnated substrate according to the present application is to provide an appropriate chemical solution impregnation property, that is, an appropriate chemical solution impregnation rate and a chemical solution retention amount. According to the above, the chemical retention amount is more than sufficient for the required performance, and therefore the chemical retention amount is not evaluated in this example.

<Fiber dropout>
Fiber shedding during measurement of internal bond strength and impregnation time was observed and evaluated on a 4-point scale.
⊚: There is almost no fiber shedding. Passed.
◯: Very little fiber loss is observed. Passed.
Δ: Considerable loss of fibers is observed. failure.
X: Fiber loss is very common. failure.

As is clear from FIG. 2, the chemical solution-impregnated base materials obtained in Examples 1 to 5 have an appropriate chemical solution impregnation rate and internal bond strength, and have an internal bond strength that can withstand a cutting step and a chemical solution impregnation step. are doing.

On the other hand, the chemical impregnated substrate obtained in Comparative Example 1 had a slow chemical impregnation rate and was inferior to the chemical impregnation rate. Further, the chemical-impregnated base material obtained in Comparative Example 2 was inferior in internal bond strength. The basic configuration of each of these comparative examples is the same as that of Examples 1 and 2, and the only difference from Examples 1 and 2 is whether the beating method is single beating or mixed beating. From this, it is considered that the problem of the chemical-impregnated base material obtained in Comparative Examples 1 and 2 is that the beating of the mercerized pulp did not proceed sufficiently due to the mixed beating.

Next, the chemical-impregnated base materials obtained in Comparative Examples 3 and 8 were both unacceptable due to their slow chemical-impregnated speed. It is considered that this is because the Canadian standard freeness of the mercerized pulp was lower than 650 ml and the density of the chemical impregnated substrate became too high, so that the chemical impregnation rate slowed down.

Further, the chemical-impregnated base material obtained in Comparative Example 4 was inferior in internal bond strength and permeation time. This is due to the use of cotton linter pulp instead of mercerized pulp, and at the same degree of freeness, cotton linter pulp is weaker than mercerized pulp and is less bulky. Probably the reason.

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

The chemical-impregnated base material obtained in Comparative Example 7 was unacceptable due to a large amount of fibers falling off. This was due to insufficient beating of the mercerized pulp and a Canadian standard drainage (freeness) of more than 750 ml, and the fibers were liable to fall off due to weak entanglement with other pulp. it is conceivable that.

Since the density of the chemical-impregnated substrate obtained in Comparative Example 9 was too high, the permeation time was long and the chemical-impregnated substrate was inferior.

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

Claims (2)

A pulp slurry preparation step in which a mercerized pulp having a Canadian standard drainage (freeness) of 650 to 750 ml CSF and a non-mercerized pulp are mixed to form a pulp slurry.
A method for producing a chemical-impregnated base material, which comprises a papermaking 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. 18-2 (Paper and paperboard - internal bond strength test method - Part 2: Internal Bond Tester Method) internal bond strength, as measured by the Ri der least 50 mJ, and the mercerized pulp, the non-mercerized pulp Is a method for producing a chemical-impregnated base material , each of which is individually beaten . The method for producing a chemical-impregnated base material according to claim 1 , wherein the non-mercerized pulp has a Canadian standard drainage (freeness) of 600 to 750 ml CSF.

Images