Cooking paper

Abstract

To provide a cooking paper which is mainly composed of naturally derived fibers, and which is excellent in strength when dry and liquid absorbency even without containing petroleum-derived synthetic fibers, and also has heat resistance.SOLUTION: The problem is solved by pulp-containing non-woven cooking paper obtained by entangling pulp fibers and regenerated cellulose fibers, the regenerated cellulose fibers being non-synthetic fibers, the cooking paper containing no adhesive, and the cooking paper having a basis weight of 30-90 g / m2.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to cooking paper. [Background technology]

[0002] Conventionally, cooking paper is used mainly for cooking, and for example, cooking paper using pulp fibers as a base sheet and bonding the pulp fibers by a latex bond method to prevent them from falling off is known. Patent Document 1 can be cited as an example of such cooking paper.

[0003] The problem to be solved by the invention in Patent Document 1 is to provide cooking paper that has a good texture, is not easily torn when wet, and has little shedding of paper powder (lint), and the invention that solves this problem is cooking paper using a nonwoven fabric with a specified basis weight, sheet density, compression work, and wet tensile strength. The nonwoven fabric is made of wood pulp fibers bonded to a fiber sheet by the latex bond method.

[0004] In addition to the above, other known products include cooking paper made of nonwoven fabric in which the raw material for the base sheet is not only pulp fiber but also polypropylene resin; base sheets containing rayon bonded with a latex adhesive to improve washing durability; and base sheets made of pulp fiber with a rayon fiber layer laminated thereon.

[0005] On the other hand, in recent years, the problem of marine pollution caused by microplastics has attracted attention, and the use of plastic in various products is being reduced or eliminated worldwide due to environmental considerations, etc. Conventional cooking paper contains more than 20% petroleum-derived synthetic fibers, and it is desirable to reduce the amount of petroleum-derived synthetic resin used in cooking paper in an environmentally friendly way. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2016-13306 A Summary of the Invention [Problem to be solved by the invention]

[0007] However, some consumers today avoid cooking paper that contains resin materials, while others prefer cooking paper that is mostly made of natural materials, and for these consumers, cooking paper made with synthetic latex as an adhesive or containing nonwoven fabric mixed with resin does not meet their needs. However, if the proportion of synthetic fibers derived from petroleum is reduced and the proportion of pulp fibers is simply increased, there is a concern that the strength will decrease. Furthermore, even if the strength of cooking paper is increased by applying a binder or adhesive, the application of the binder, etc., tends to reduce the liquid absorption, which is a drawback in that it is costly. On the other hand, cooking paper containing polypropylene resin, etc., has a bottleneck in the melting point of polypropylene resin, limiting the use of cooking paper during high-temperature cooking.

[0008] Therefore, the main object of the present invention is to provide cooking paper that is primarily composed of fibers derived from natural products and does not contain synthetic fibers derived from petroleum, yet has excellent strength and liquid absorbency when dry, as well as heat resistance. [Means for solving the problem]

[0009] The means for solving the problems of the present invention are as follows. The first method is A pulp-mixed nonwoven fabric in which pulp fibers and regenerated cellulose fibers are entangled, The regenerated cellulose fibers are non-synthetic fibers, Contains no adhesive Basis weight: 30~90g / m 2 That is, 1. A pulp-mixed nonwoven cooking paper.

[0010] The second method is The blending ratio of the pulp fiber and the regenerated cellulose fiber is 50:50 to 80:20. The pulp-mixed nonwoven cooking paper according to the first aspect.

[0011] The third method is The fiber length of the regenerated cellulose fiber is 21 mm or more and 78 mm or less. The pulp-mixed nonwoven cooking paper according to the first aspect.

[0012] The fourth measure is The regenerated cellulose fiber is composed of either or both of lyocell fiber and rayon fiber. The pulp-mixed nonwoven cooking paper according to the first aspect.

[0013] The fifth measure is: The regenerated cellulose fiber is made of at least one of lyocell fiber and rayon fiber, The blend ratio of lyocell and rayon is 100:0 to 0:100. The pulp-mixed nonwoven cooking paper according to the first aspect.

[0014] The sixth method is: The pulp fibers and the regenerated cellulose fibers are hydroentangled from one side of the pulp-mixed nonwoven fabric, At least the other surface has convex portions formed at a pitch of 2 to 6 mm. The pulp-mixed nonwoven cooking paper according to the first aspect. Effect of the Invention

[0015] According to the present invention, cooking paper is provided which is mainly composed of fibers derived from natural products and does not contain synthetic fibers derived from petroleum, yet has excellent strength and liquid absorbency when dry, as well as heat resistance. [Brief description of the drawings]

[0016] [Figure 1]FIG. 2 is an explanatory diagram of the convex portions of the pulp-mixed nonwoven cooking paper of the present embodiment and a method for forming the convex portions. [Diagram 2] FIG. 2 is a plan view illustrating the convex portions of the pulp-mixed nonwoven cooking paper of the present embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] Next, embodiments of the present invention will be described in detail below with reference to the drawings. However, the present invention is not limited to these embodiments.

[0018] The pulp-mixed nonwoven cooking paper of this embodiment is a pulp-mixed nonwoven fabric in which pulp fibers and regenerated cellulose fibers are entangled, and is characterized in that the regenerated cellulose fibers are non-synthetic fibers and do not contain an adhesive. The basis weight of the pulp-mixed nonwoven cooking paper of this embodiment is preferably 30 to 90 g / m 2 and more preferably 45 to 80 g / m 2 and preferably 50 to 60 g / m 2 The basis weight is 30 to 90 g / m 2 In this case, in combination with other configurations of the present invention, the strength of the paper can be sufficient for use as cooking paper. The basis weight is measured based on JIS P 8124.

[0019] The thickness of the pulp-mixed nonwoven cooking paper of this embodiment is not necessarily limited, but is preferably 450 to 900 μm. Note that this thickness refers to a value measured based on JIS L 1913.

[0020] The total ratio of pulp fibers and regenerated cellulose fibers in the constituent fibers of the pulp-mixed nonwoven cooking paper of this embodiment is 95% or more. It is preferably 100%. Since pulp fibers and regenerated cellulose fibers are fibers derived from natural products, if the total ratio of pulp fibers and regenerated cellulose fibers is 95% or more, it can be said that the cooking paper has been sufficiently plastic-free compared to conventional cooking papers. Also, if it is 100%, it can be said that the cooking paper is plastic-free. If fibers other than pulp fibers and regenerated cellulose fibers are included, it is desirable that the fibers are natural fibers from the viewpoint of plastic-free. However, plastic reduction can be sufficiently achieved even if synthetic fibers are included at 5% or less.

[0021] The regenerated cellulose fiber in the pulp-mixed nonwoven cooking paper of this embodiment is not particularly limited as long as it is a non-synthetic fiber, but can be, for example, either one or both of lyocell fiber and rayon fiber. Non-synthetic fibers are fibers other than those synthesized and manufactured mainly from petroleum by chemical processes, and examples of such fibers include natural polymer compounds and those made by dissolving natural polymer compounds as raw materials and then spinning them, such as rayon fiber, cupra fiber, and lyocell fiber. Examples of synthetic fibers include polyester fiber, nylon fiber, acrylic fiber, and polyurethane resin.

[0022] Lyocell fiber is a regenerated cellulose fiber obtained by organic solvent spinning method, and is not derived from petroleum raw materials like nylon and polyester. Instead, wood pulp (craft pulp, sulfite pulp, etc.), cotton pulp, non-wood pulp (linter pulp, etc.) are dissolved in an organic solvent to obtain a cellulose solution, which is then sprayed into the liquid from a fine nozzle to precipitate in the form of threads, forming fibers. Here, amine oxide, 1-ethyl-3-methylimidazolinium acetate, etc. can be used as the organic solvent. For example, Tencel (registered trademark) manufactured by Lenzing Aktiengesellschaft is available on the market.

[0023] Rayon fiber is not derived from petroleum-based materials like nylon and polyester, but is a regenerated cellulose fiber that can be produced by the viscose process using cellulose contained in pulp, for example, as a raw material.

[0024] In the pulp-mixed nonwoven cooking paper of this embodiment, the regenerated cellulose fibers are either lyocell fibers or rayon fibers, or both, so that even if the synthetic fiber content is less than 5%, particularly 0%, the strength when dry is sufficient for general use. The pulp-mixed nonwoven cooking paper of this embodiment contains regenerated cellulose fibers, which are soft and have an excellent touch and are hydrophilic, so that the pulp-mixed nonwoven cooking paper containing the regenerated cellulose fibers is flexible and has good water absorbency.

[0025] Furthermore, when the recycled cellulose fiber contained in the pulp-mixed nonwoven cooking paper of this embodiment contains lyocell fiber, the strength when wet is sufficient for use as cooking paper, as well as the strength when dry. In other words, the cooking paper has excellent strength when dry, and the inclusion of lyocell fiber means that there is no or small change in strength when dry to wet and when wet to dry, making it even easier to use in kitchens where wiping off both dry objects and liquids is required.

[0026] The pulp-mixed nonwoven cooking paper of this embodiment contains regenerated cellulose fibers, which are derived from wood and have excellent heat resistance. Many conventional cooking papers are processed with nonwoven fabrics or resins made of synthetic fibers with relatively high heat resistance in order to impart heat resistance. However, even cooking papers that have been heat-resistant in this way may adhere to cooking utensils when cooking at high temperatures. On the other hand, the pulp-mixed nonwoven cooking paper of this embodiment is made of pulp fibers and regenerated cellulose fibers, so that the fibers themselves have a relatively high heat resistance, and there is no need to process the base paper of the cooking paper with a heat-resistant resin. In particular, the pulp-mixed nonwoven cooking paper is in the form of a nonwoven fabric, and the fibers are not bonded together with a binder (adhesive, etc.), but have many voids formed by the entanglement of the fibers, making it difficult for heat conduction to occur between the fibers. Therefore, the pulp-mixed nonwoven cooking paper is not easily deformed even when hot food is placed on or wrapped around it, and does not decompose thermally up to 400 degrees. Therefore, even if it comes into contact with hot food, it will not immediately decompose due to heat, and can be used for food at a wide range of temperatures. The heat-resistant temperature (thermal decomposition temperature) can be measured, for example, using a "high-temperature electric furnace" product of Advantech Toyo Co., Ltd., by placing the cooking paper in the furnace, starting to heat it up, and measuring the temperature at which carbonization (or melting) is confirmed.

[0027] The regenerated cellulose fiber used in the pulp-mixed nonwoven cooking paper of this embodiment has a fiber length of preferably 21 mm to 78 mm, more preferably 28 mm to 65 mm, and more preferably 38 mm to 43 mm. The fiber length of the lyocell fiber is preferably 21 mm to 78 mm, more preferably 28 mm to 65 mm, and more preferably 38 mm to 43 mm. The fiber length of the rayon fiber is preferably 21 mm to 78 mm, more preferably 28 mm to 65 mm, and more preferably 38 mm to 43 mm. The regenerated cellulose fiber with a fiber length of 21 mm to 78 mm is easily entangled with pulp fibers, especially pulp fibers derived from conifers, and is difficult to disentangle, resulting in a pulp-mixed nonwoven cooking paper that is particularly unlikely to generate lint. In addition, regenerated cellulose fibers having a fiber length in this range can be suitably entangled with pulp fibers, particularly pulp fibers derived from conifers, by hydroentanglement. Therefore, when the pulp-mixed nonwoven cooking paper of this embodiment is made by entangling pulp fibers and regenerated cellulose fibers by hydroentanglement, the entanglement is suitably performed, and in combination with the effect of hydroentanglement described later, lint is particularly unlikely to occur. The fiber length according to the present invention is the length-weighted average fiber length L(l) measured using a fiber length measuring device (Metso Automation, Kayani / Fiber Lab) for the defibrated fibers after defibration in accordance with JIS P 8220. If it is not possible or difficult to measure using this fiber length measuring device, the nonwoven fabric, the fiber length of which is known based on the information on "dtex" from the raw cotton production marker, and the fiber can be observed under an electron microscope, and a contrast measurement can be performed, and a judgment can be made from the comparison result.

[0028] The fiber thickness of the regenerated cellulose fiber in the pulp-mixed nonwoven cooking paper of this embodiment is not necessarily limited, but the fiber thickness of the lyocell fiber is preferably 0.8 dtex or more and 1.8 dtex or less, particularly preferably 1.0 dtex or more and 1.7 dtex or less. The fiber thickness of the rayon fiber is preferably 0.8 dtex or more and 1.8 dtex or less, particularly preferably 1.0 dtex or more and 1.7 dtex or less. With this fiber thickness, the regenerated cellulose fiber tends to be firmly entangled with the pulp fiber, especially the pulp fiber derived from coniferous trees. The fiber thickness can be calculated from the specific gravity of the fiber, the thickness measured by observation under an electron microscope as in the previous section, and the cross-sectional shape.

[0029] The pulp fibers in the pulp-mixed nonwoven cooking paper of this embodiment can be selected from pulp fibers derived from broadleaf trees, pulp fibers derived from coniferous trees, and pulp fibers derived from waste paper. The average fiber length (hereinafter also referred to as the fiber length) is preferably 3.0 to 5.0 mm, which is easy to entangle with regenerated cellulose fibers. Among the above pulp fibers, pulp fibers derived from coniferous trees are particularly preferable. The pulp fibers derived from coniferous trees have an average fiber length of 3.5 to 4.0 mm and a fiber diameter of about 50 μm, which are easy to entangle with regenerated cellulose fibers and are particularly unlikely to generate lint derived from the pulp fibers. Specifically, they are bleached coniferous kraft pulp (NBKP) and unbleached coniferous pulp (NUKP). The pulp fibers preferably contain 95% by mass or more of the pulp fibers derived from coniferous trees. In particular, the pulp fibers preferably contain 100% by mass of pulp fibers derived from coniferous trees. The average fiber length of this pulp fiber is the length-weighted average fiber length L(l) measured on the disintegrated fibers after disintegration in accordance with JIS P 8220 using a fiber length measuring device (Kayani / Fiber Lab, manufactured by Metso Automation).

[0030] The blending ratio of pulp fiber to regenerated cellulose fiber in the pulp-mixed nonwoven cooking paper of this embodiment is not necessarily limited, but is preferably pulp fiber:regenerated cellulose fiber=50:50 to 80:20. Particularly preferably, pulp fiber:regenerated cellulose fiber=60:40 to 80:20. When the pulp fiber:regenerated cellulose fiber=50:50 to 80:20, the liquid absorption property due to the pulp fiber, the improvement of the heat resistance of the cooking paper due to the regenerated cellulose fiber, and the suppression of lint generation are well balanced, and the pulp-mixed nonwoven cooking paper has good flexibility and softness, and does not contain resin, resulting in a pulp-mixed nonwoven cooking paper with reduced environmental impact.

[0031] On the other hand, the entanglement of the pulp fibers and regenerated cellulose fibers in the pulp-mixed nonwoven cooking paper of this embodiment is preferably, but not necessarily, hydroentanglement (spunlace method). Therefore, the pulp-mixed nonwoven cooking paper of this embodiment may have fibers oriented in the thickness direction such that one side has an excess of pulp fibers and the other side has an excess of regenerated cellulose fibers, and the blending ratio of fiber types may be different between the front and back sides.

[0032] The entanglement of the pulp fibers and the regenerated cellulose fibers in the pulp-mixed nonwoven cooking paper of this embodiment is preferably achieved by hydroentanglement as described above. That is, the pulp-mixed nonwoven cooking paper of this embodiment is preferably a pulp-mixed nonwoven fabric by the spunlace method, also known as a spunlace nonwoven fabric or a spunlace-type nonwoven fabric. If the entanglement of the pulp fibers and the regenerated cellulose fibers is achieved by hydroentanglement, fine pulp fibers will fall off during production due to the water flow, resulting in less lint generation. In addition, the pulp-mixed nonwoven cooking paper of this embodiment may have fibers oriented in the thickness direction, such that one side is a pulp surface with an excess of pulp fibers and the other side is a regenerated cellulose surface with an excess of regenerated cellulose fibers, and the fiber type blending ratio may be different between the front and back sides. Of course, the fiber orientation may be uniform in the thickness direction.

[0033] Here, the particularly preferred hydroentanglement of the pulp-mixed nonwoven cooking paper of this embodiment is preferably carried out as follows. That is, as shown in FIG. 1, a pulp slurry is discharged onto the regenerated cellulose fiber web 20 after carding to laminate the pulp fibers 10 in a wet paper state, and then, in accordance with the spunlace technology also called water jet technology, water needle technology, etc., a water stream 30 is sprayed and struck against the wet paper surface of the laminated sheet in which the wet paper 10 of pulp fiber and the regenerated cellulose fiber web 20 are laminated, so that the pulp fibers of the wet paper 10 penetrate into the regenerated cellulose fibers of the regenerated cellulose fiber web 20 to hydroentangle. In this hydroentanglement, the fiber length and fiber thickness of the pulp fibers and lyocell fibers derived from the above-mentioned coniferous trees are particularly preferable. Note that the wet paper and the fiber web may be laminated in multiple layers, but it is preferable to laminate each one layer.

[0034] When the regenerated cellulose fibers are composed of rayon fibers and lyocell fibers, a nonwoven sheet is formed by the spunbonding method or the meltblowing method using a mixture of rayon fibers and lyocell fibers as the raw material, and this nonwoven sheet is laminated with a pulp sheet and hydroentangled in accordance with the spunlace technology.

[0035] In this hydroentanglement, the pulp sheet is preferably not a paper made by papermaking, but a pulp suspension in which pulp fibers are dispersed and suspended in water, discharged onto a conveying plane, and compressed and dried in a heating drum to form a sheet. The drying temperature is 85 to 115°C, preferably 90 to 110°C. The dried pulp sheet has small fiber orientation in the length and width directions, and the aspect ratio difference of the dry tensile strength is small.

[0036] The nozzle diameter of the nozzle for spraying the water flow used for hydroentanglement is preferably 0.5 to 1.5 mmφ, more preferably 0.75 to 1.25 mmφ. This nozzle diameter is smaller than that of the nozzle system used in the conventional spunlace method. The water pressure to be sprayed is not necessarily limited, but is preferably 350 to 450 bar, particularly preferably 380 to 420 bar. This water pressure is higher than the general water pressure (80 to 90 bar). By spraying a high-pressure water flow from a small-diameter nozzle against the pulp sheet, the pulp fibers and regenerated cellulose fibers are well entangled, and in particular, the pulp fibers are well inserted into the regenerated cellulose fiber nonwoven sheet surface, making it difficult for the pulp fibers to separate from the front and back of the cooking paper and less likely to generate lint.

[0037] In the pulp-mixed nonwoven cooking paper formed by hydroentanglement, when the water flow hits the laminated web, the regenerated cellulose fibers and pulp fibers move, forming a convex pattern. In particular, the proportion of pulp fibers is high in the convex parts. In this shape, the tensile strength in the concave parts is guaranteed by the regenerated cellulose fibers, while the softness is remarkably excellent. In addition, the pulp fibers gathered in the convex parts give the paper an excellent sense of bulk, and the paper has excellent water and oil absorption properties, allowing it to retain moisture and oil well. Because of these properties, the paper can be suitably used in cooking, such as squeezing and draining soft ingredients such as tofu and vegetables.

[0038] In the pulp-mixed nonwoven cooking paper of this embodiment, the pulp fibers and regenerated cellulose fibers can be kept entangled and the fibers can be bonded together by heat fusion using a binder (adhesive) or binder fibers such as heat-fusible fibers, but applying a binder or binder fiber can reduce liquid absorption and increase costs. In particular, since many binder fibers are not derived from natural products and prevent the shift away from plastics, it is preferable that the pulp-mixed nonwoven cooking paper of this embodiment does not use binders or binder fibers and does not contain synthetic fibers derived from petroleum.

[0039] On the other hand, the pulp-mixed nonwoven cooking paper of this embodiment has protrusions 60 formed by hydroentanglement on at least one side, as shown in Figure 1. The protrusions 60 improve the wiping ability to scrape off dirt and increase softness. In addition, the protrusions 60 formed by hydroentanglement have planar fiber orientation, and fine pulp fibers fall off during entanglement, so that the generation of lint is particularly effectively reduced. Note that recesses corresponding to the protrusions may be formed on the opposite side of the protrusions.

[0040] The formation of the convex portions 60 by hydroentanglement can be achieved by treating the conveying surface 40, such as a conveying wire, conveying mesh, etc., that conveys the laminated sheet formed by stacking the pulp fibers of the wet paper and the regenerated cellulose fiber web described above, as having irregularities and holes, and applying a water flow to the laminated sheet on this conveying surface to transfer the shape of the irregularities and holes to the sheet while entangling it.

[0041] Moreover, it is preferable that the convex portions 60 formed by this water flow entanglement are convex portions formed on the regenerated cellulose surface side. As shown in Fig. 1, this preferable convex portion 60 can be formed by having holes 50 on the conveying surface 40 conveying the laminated sheet in which the pulp fibers of the wet paper 10 and the regenerated cellulose fiber web 20 are laminated, and applying a water flow 30 from the wet paper surface side. The convex portions 60 are formed by the pulp fibers entangled with the regenerated cellulose fibers gathering in the holes 50, and fine pulp fibers can fall out through the holes 50, so that lint is particularly unlikely to occur.

[0042] The pitch of the projections is not limited, but as shown in FIG. 2, the pitch L1 is preferably 2 to 6 mm. The pitch L1 refers to the distance between the projections 60 arranged regularly in the flow direction (MD) and the direction perpendicular to the flow direction (CD). The minimum distance L2 between the projections 60 on the pitch is not necessarily limited, but is preferably 0.5 to 2.5 mm. The shape of the projections 60 is not necessarily limited, particularly in the case of hydroentanglement, since the edges of the shape are not clear, but is preferably circular, elliptical, approximately circular, or approximately elliptical. The size is not limited, but in the case of a circle or ellipse, the diameters L3 and L4, the minor axis L3, and the major axis L4 are preferably 2 to 5 mm.

[0043] In the case of the pulp-mixed nonwoven cooking paper of this embodiment, when the paper is entangled by spraying a water stream, the surface sprayed with the water stream is sometimes called the front surface, and the surface facing the conveyor wire is sometimes called the back surface.

[0044] Rayon fibers tend to lose tensile strength when they change from a dry state to a wet state, whereas Lyocell fibers do not lose as much tensile strength when they change from a dry state to a wet state as rayon fibers. That is, Lyocell fibers are relatively less likely to lose tensile strength when they change from a dry state to a wet state. Therefore, the pulp-mixed nonwoven cooking paper of this embodiment can adjust the degree of loss in tensile strength when it changes from a dry state to a wet state by changing the content ratio of rayon fibers and Lyocell fibers in the regenerated cellulose fibers.

[0045] The content ratio of rayon fiber and lyocell fiber contained in the regenerated cellulose fiber can be changed according to the use of the cooking paper, and the regenerated cellulose fiber may be composed of only rayon fiber, or the regenerated cellulose fiber may be composed of only lyocell fiber. The regenerated cellulose fiber may contain both rayon fiber and lyocell fiber, and when it is desired to obtain cooking paper that is less likely to lose tensile strength even when it is changed from a dry state to a wet state, the content ratio of lyocell fiber is increased, for example, rayon fiber mass%: lyocell fiber mass% = 100:0 to 0:100, preferably rayon fiber mass%: lyocell fiber mass% = 50:50 to 0:100. With such a content ratio, the pulp-mixed nonwoven cooking paper of this embodiment can also be used as a duster for wiping off liquid dirt in the kitchen.

[0046] Considering pulp-mixed nonwoven cooking paper in which the regenerated cellulose fibers are composed only of rayon fibers, the values ​​of (wet tensile strength) / (dry tensile strength) in the longitudinal direction and (wet tensile strength) / (dry tensile strength) in the transverse direction of the pulp-mixed nonwoven cooking paper are both 0.5 or more, preferably 0.8 or more. If the values ​​of (wet tensile strength) / (dry tensile strength) in both the longitudinal and transverse directions are 0.5 or more, the cooking paper will not immediately tear or stick to cooking utensils or countertops even if it absorbs liquid, and can be used without problems in cooking.

[0047] The specific dry tensile strength of the pulp-mixed nonwoven cooking paper of this embodiment is not necessarily limited, but is preferably 30 to 80 N / 50 mm in the longitudinal direction and 10 to 50 N / 50 mm in the transverse direction. The wet tensile strength is also not necessarily limited, but is preferably 20 to 80 N / 50 mm in the longitudinal direction and 12 to 64 N / 50 mm in the transverse direction, and more preferably 50 to 70 N / 50 mm in the longitudinal direction and 18 to 40 N / 50 mm in the transverse direction. If it is within this range, it is a strength sufficient for wiping. The dry tensile strength and wet tensile strength are measured based on JIS L 1913 (2010) "6.3 Tensile strength and elongation rate (ISO method). Specific examples of the measuring device include the "Universal tension and compression tester TG-200N" manufactured by Minebea Co., Ltd. and its equivalents.

[0048] On the other hand, it is desirable that the MMD (variation of coefficient of friction) of both the front and back of the pulp-mixed nonwoven cooking paper of this embodiment is 6.0 or less. MMD is one of the indicators of smoothness. If the MMD is within the above range, it can be said that the smoothness of the pulp-mixed nonwoven cooking paper is sufficient. The MMD is a value measured using a friction tester KES-SE, KES-SESRU, or their equivalents manufactured by Kato Tech Co., Ltd. The MMD is the degree of variation from the MIU (mean coefficient of friction), and the smaller the value, the smoother it is. The measurement conditions are that the contact surface of the friction element is brought into contact with the surface of the measurement sample to which a tension of 20 g / cm is applied in a predetermined direction with a contact pressure of 25 g, and the friction element is moved 2 cm in approximately the same direction as the tension is applied at a speed of 0.1 cm / s. The measurement is performed five times, and the average value is taken as the MMD. The friction element is a piano wire sensor that is a standard accessory of the above tester. This piano wire sensor has a contact surface formed of 20 adjacent piano wires with a diameter of 0.5 mm, with a length and width of 10 mm. The contact surface has a unit bulge at the tip formed by 20 piano wires (with a curvature radius of 0.25 mm).

[0049] The pulp-mixed nonwoven cooking paper of this embodiment desirably has a softness value of 20cN / 100mm or less on both the front and back sides. If the softness value is 20cN / 100mm or less, it feels supple and soft when used for cooking. The softness was measured according to the handle-o-meter method in accordance with JIS L 1096 E method. However, the test piece was 100mm x 100mm in size, and the clearance was 20mm. Measurements were performed five times in the vertical and horizontal directions on both the front and back sides, and the average value of the five measurements was expressed in units of cN / 100mm.

[0050] The pulp-mixed nonwoven cooking paper of the present embodiment preferably has an oil absorption of 500 to 900 g / m 2 , more preferably 530 to 800 g / m 2 When the oil absorption is within the above range, oil can be absorbed appropriately, and oil stains on the kitchen counter can be easily wiped off.

[0051] As described above, the pulp-mixed nonwoven cooking paper according to the present embodiment has excellent water absorption and strength even though it does not contain synthetic fibers derived from petroleum, and has excellent versatility suitable for cleaning, wiping, and wiping off dirt and liquids from food, objects, and living organisms such as the human body. In addition, it generates little lint and has excellent heat resistance. Furthermore, it is sufficiently flexible and smooth. EXAMPLES

[0052] Next, tests were carried out on the pulp-mixed nonwoven cooking paper according to the present embodiment (Examples 1 to 9) and conventional cooking paper (Comparative Examples 1 and 2). All of the examples were pulp-mixed nonwoven cooking paper produced by hydroentanglement.

[0053] In the comparative example, pulp and synthetic fibers are entangled. In the examples and comparative examples, the water pressure during hydroentanglement is 395 to 400 bar, and in the conventional example, it is 230 bar. In the examples, the lyocell fiber has a thickness of 1.67 dtex and a fiber length of 38 mm, and the rayon fiber has a thickness of 1.33 dtex and a fiber length of 38 mm. The pulp fiber used is softwood kraft pulp. In each example, no fiber type other than that shown in Table 1 is used.

[0054] The convex portion has the shape shown in FIG. 1, and the shape of each convex portion is an ellipse (minor axis L3 = 2.8 mm × major axis L4 = 3.0 mm) that is slightly elongated in the direction perpendicular to the flow direction (CD direction), and the pitch is 4.2 mm in the flow direction (MD direction) L1 and 4.5 mm in the direction perpendicular to the flow direction L2.

[0055] The test results are shown in Tables 1 and 2. The physical properties and the like for the examples and comparative examples are shown in Table 1. The test methods were as follows.

[0056] [Tensile strength] Measurements were made based on JIS L 1913 (2010) "6.3 Tensile strength and elongation (ISO method). Dry and wet tensile strengths were measured. The test machine used was a load cell tensile tester TG-200N manufactured by Minebea Co., Ltd. Measurements were performed by clamping both ends of the test piece to the grips of the test machine, applying a tensile load to the sample in the vertical direction, and reading the indicated value (digital value) when the sample breaks. The tensile speed was 100 mm / min. Five sets of samples were prepared in both the vertical and horizontal directions and measurements were made five times each, and the average of the measured values ​​was taken as the tensile strength in each direction.

[0057] [Water absorption] The water absorption was measured according to the following (1) to (5). (1) Measure the mass of the test piece using an electronic balance (such as A&D HR300). (2) Pour 25°C water into a tray larger than the test specimen (e.g., inner dimensions: 215 mm x 160 mm) to a depth of approximately 20 mm. (3) The test piece is spread out and placed on a rigid flat net (e.g., 120 mm x 120 mm, mesh size 15 mm) that is larger than or equal to the test piece, and then lowered into the tray containing the water so that the test piece is immersed in the water so that it comes into contact with the water surface. (4) When the water has sufficiently soaked into the surface of the test piece, raise the net directly above the water surface, pinch a corner of the test piece with tweezers, and leave it in that position for 30 seconds. (5) After 30 seconds, the mass of the test piece that has absorbed water is measured using an electronic balance and calculated using the following formula: 2 Calculate the amount of water absorbed per unit. Water absorption (g / m 2 ) = ((Mass of the water-absorbed test piece measured in (4) above) - (Mass of the test piece measured in (1) above)) x 100 (Note: m 2 (Multiply by 100 to convert to

[0058] [Oil absorption amount] The oil absorption was measured as follows (1) to (5). (1) Measure the mass of the test piece using an electronic balance (such as A&D HR300). (2) In a tray larger than the test specimen (for example, inner dimensions: 215 mm x 160 mm), pour salad oil (Nissin Salad Oil: manufactured by Nisshin Oillio Group, Ltd.) at 25°C to a depth of approximately 20 mm. (3) The test piece is spread out and placed on a rigid flat net (e.g., 120 mm x 120 mm, mesh size 30 mm) that is larger than or equal to the test piece, and then lowered into the tray containing the salad oil so that the test piece is immersed in the oil so that it comes into contact with the oil surface. (4) When the salad oil has soaked into the surface of the test piece, raise the flat net directly above the oil surface, leave it there for 30 seconds, then pick up a corner of the test piece with tweezers and transfer the test piece to a pre-weighed measurement container. At this time, do not allow more than 30 seconds from when the flat net is raised above the oil surface and left there until it is transferred to the measurement container. (5) The mass of the measuring vessel containing the test piece is measured using an electronic balance, and the mass of the test piece after oil absorption is calculated by subtracting the mass of the measuring vessel from the measured mass. Then, the mass of the test piece after oil absorption is calculated by the following formula: 2 The oil absorption per unit is calculated. Oil absorption (g / m2 ) = ((Mass of the oil-absorbed test piece measured in (4) above) - (Mass of the test piece measured in (1) above)) x 100 (Note: m 2 (Multiply by 100 to convert to

[0059] [Water absorption speed] The water absorption rate was measured as follows (1) to (4). (1) Prepare a 100 mm x 100 mm test piece. (2) Place the test piece on a stand (such as a tripod for an alcohol lamp) that has a hole with a diameter of 40 mm or more in the center, so that the center of the test piece is positioned over the hole. (3) 300 μl of water at 25° C. is dropped with a micropipette at a height of 10 mm from the surface of the test piece to any point near the center of the test piece. This dropping can be done, for example, with an AS ONE Pipette Guy PG-1000, set to 300. (4) The time from the moment the water from the micropipette contacts the test piece to the moment the water completely penetrates the test piece is measured with a stopwatch, and this time is taken as the water absorption rate (sec). The completion of penetration is determined by visually confirming that the glossy reflection of water disappears from the surface of the test piece.

[0060] [Softness] Measurements were performed using the handle-o-meter method in accordance with JIS L 1096 E. However, the test pieces were 100 mm x 100 mm in size, and the clearance was 20 mm. Measurements were performed five times each in the vertical and horizontal directions on the front and back sides, and the average of the five measurements was expressed in units of cN / 100 mm.

[0061] [MMD] (Frictional resistance MIU) Measurements were performed using an automated surface tester KES-FB-4-AUTO manufactured by Kato Tech Co., Ltd. The contact surface of the frictional element was brought into contact with the surface of the measurement sample to which a tension of 20 g / cm was applied in a predetermined direction at a contact pressure of 25 g, and moved 2 cm at a speed of 0.1 cm / s in approximately the same direction as the tension was applied. The frictional element was a standard accessory 10 mm square piano wire sensor (20 pieces). MMD and MIU were measured five times for each surface, and the average values ​​were calculated.

[0062] [Lint removal performance (lint view tester)] The lint removal performance was measured according to the following procedure. (1) Prepare a test piece measuring 240 mm x 200 mm. (2) Fold the test piece in half and soak it in pure water. Then, place two pieces of 300 mm x 300 mm filter paper (125 g / m 2 ) are placed between five pieces of the sample. (3) The sample is sandwiched between filter paper and a 2.86 kg iron roll (diameter 65 mm, face length 2500 mm) is moved back and forth five times over the filter paper to dehydrate it. (4) The sample is separated from the filter paper, and the wet two-fold test piece is unfolded into one sheet, which is then placed on a carrier sheet and the number of lint particles adhering to the sample is measured using an IGT Lint View Tester (manufactured by IGT Sisting Systems Co., Ltd.). The tape used for this measurement is number "D," which has the strongest adhesive strength, and the measurement is performed in the direction of a length of 240 mm by a width of 50 mm. The lint particles to be counted are visible and are 0.5 mm or larger. (5) The number of visible particles measuring 0.5 mm or more, 0.75 mm, 1.0 mm, 2.0 mm, and 3 mm or more was measured three times in both directions in the flow direction (total of six times), and the average value was calculated. (6) The relative values ​​are values ​​obtained by dividing the average value of each example by the average value of Comparative Example 1, with Comparative Example 1 as the standard. The reason for using relative values ​​is that the adhesiveness of the adhesive tape used in the measurement changes depending on the measurement environment and over time, and the absolute numbers vary widely.

[0063] [With or without protrusions] The presence or absence of convex portions was confirmed by visual inspection of the test pieces. A convex pattern arranged as shown in Fig. 2 was confirmed on the regenerated cellulose fiber side of each of the test pieces of Examples 6 to 9. Each of the convex portions was an ellipse (circle) with a major axis (or diameter) of 2.8 mm.

[0064] [Thermal decomposition temperature (heat-resistant temperature)] The test pieces were heated to measure the temperature at which they were carbonized (or melted). For the test pieces of Examples 1 to 9, carbonization (thermal decomposition) was observed when the temperature exceeded 400°C. For the test pieces of Comparative Examples 1 and 2, melting of polypropylene was observed at 160°C.

[0065] [Lint removal performance (paper dust amount / mirror)] The lint removal performance (amount of paper powder / mirror) was measured as follows (1) to (3). (1) Prepare a test piece measuring 405 mm x 280 mm. (2) After immersing the test piece in tap water, squeeze it out between the palm of your hand and wipe the mirror while it is still wet. (3) The condition of the paper powder adhering to the mirror is visually confirmed, and each example is relatively rated on a scale of 1 to 9, with Comparative Example 1 being set as the standard of 10.

[0066] [Lint removal performance (paper dust amount / count number)] The lint removal performance (amount of paper powder / count number) was measured as follows (1) to (3). (1) Prepare a test piece measuring 405 mm x 280 mm. (2) After immersing the test piece in tap water, squeeze it out between the palm of your hand and, while still wet, wipe a 60 mm x 60 mm acrylic plate. (3) An arbitrary 24 mm x 18 mm area from the wiped area is magnified with a KEYENCE One-Shot 3D Measuring Macroscope VR-3200, and the number of paper particles in the area is visually counted. The relative value of each example is the value obtained by dividing the measurement value of each example by the measurement value of Comparative Example 1.

[0067] [Table 1] [Table 2]

[0068] Looking at the test results in Table 1, the examples of the present invention, in which the fibers were pulp fibers and lyocell fibers, had tensile strengths in both dry and wet states that were equal to or greater than those of the comparative examples, in which the fibers were pulp fibers and synthetic polypropylene fibers. Furthermore, the difference in tensile strength between dry and wet states was small, and the strength did not decrease even when wet. Furthermore, with regard to liquid absorption properties such as water absorption, oil absorption, and water absorption speed, the examples showed better results than the comparative examples. These results demonstrate that the pulp-mixed nonwoven fabric sheet according to the present invention has excellent liquid absorbency and strength in both dry and wet states, even though it does not contain synthetic fibers derived from petroleum. In particular, the one in which the projections were formed by hydroentanglement had excellent surface smoothness and softness, and the generation of lint was particularly low. From the above results, the pulp-mixed nonwoven cooking paper of the present invention can be evaluated as being suitable for uses such as placing food on the surface of the cooking paper, using it as a drop lid, straining or draining oil, draining water, cooking in a microwave oven, wrapping food to be cooked, and wiping down cooking counters and cooking utensils. [Explanation of symbols]

[0069] 1...pulp-mixed nonwoven sheet, 10...pulp fiber layer (wet paper), 20...regenerated cellulose fiber web, 30...water flow, 40...convex surface, 50...hole, 60...convex portion, L1...pitches of concave portions (convex portions), L2...minimum spacing between concave portions (convex portions), L3...length of minor axis (diameter), L4...length of major axis (radius)

Claims

1. A pulp-mixed nonwoven fabric in which pulp fibers and regenerated cellulose fibers are entangled, The regenerated cellulose fibers are non-synthetic fibers, Contains no adhesive Basis weight: 30 to 90 g / m ２ The pulp-mixed nonwoven cooking paper is characterized by:

2. The pulp-mixed nonwoven cooking paper according to claim 1, wherein the blending ratio of the pulp fibers to the regenerated cellulose fibers is 50:50 to 80:

20.

3. 2. The pulp-mixed nonwoven cooking paper according to claim 1, wherein the regenerated cellulose fibers have a fiber length of 21 mm or more and 78 mm or less.

4. The pulp-mixed nonwoven cooking paper according to claim 1 , wherein the regenerated cellulose fibers are either or both of lyocell fibers and rayon fibers.

5. The regenerated cellulose fiber is made of at least one of lyocell fiber and rayon fiber, The pulp-mixed nonwoven cooking paper according to claim 1, wherein the blending ratio of lyocell to rayon is 100:0 to 0:

100.

6. The pulp fibers and the regenerated cellulose fibers are hydroentangled from one side of the pulp-mixed nonwoven fabric, The pulp-mixed nonwoven cooking paper according to claim 1, wherein convex portions are formed at least on the other surface at a pitch of 2 to 6 mm.

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