JP2006283194A - Sliding-screen paper - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide sliding-screen paper having excellent strength with a weak curling tendency. <P>SOLUTION: The sliding-screen paper is characterized as comprising polyolefinic conjugated binder fibers. The sliding-screen paper preferably contains the polyolefinic conjugated binder fibers in an amount of ≥15% expressed in terms of mass ratio. The polyolefinic conjugated binder fibers are preferably conjugated fibers of a sheath-core structure comprising a polyolefin as a sheath component and a polyester as a core component. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a shoji paper.

The types of shoji paper currently in common use are classified according to the raw materials used, and are used for each type according to the needs of the living environment.
In contrast to expensive shoji paper such as hand-made shoji paper using firewood and machine-made shoji paper mixed with abaca, rayon, etc., shoji paper using pulp is inexpensive and economical.

  However, shoji paper using pulp has a problem of low strength and lack of practicality. For this reason, polyvinyl alcohol binder fibers are often mixed and used, but the improvement in strength is not sufficient, and there is also a problem that the strength is particularly low when wet.

  Conventionally, in order to improve these problems, a method of using a polyester composite binder fiber in a mixed form has been proposed (for example, Patent Document 1). However, when a polyester composite binder fiber is used as a mixed paper, the strength increases, but on the other hand, there arises a problem that the winding habit becomes strong.

  The curl is the warp of the shoji paper when the shoji paper wound around the roll paper tube is unwound from the roll paper tube and attached to the crosspiece in the manufacturing process. If the curl is strong, there will be a problem that the shoji paper is peeled off from the cross due to warping until the adhesive is solidified and the shoji paper is completely attached to the cross.

  Therefore, when sticking shoji paper with strong curl to the crosspiece, it is necessary to press the shoji paper against the crosspiece with some force until the adhesive solidifies and the shoji paper is completely stuck to the crosspiece. Yes, the efficiency of the pasting work is reduced.

  There are two types of shoji paper, one for household use in individual households and one for business use by building material manufacturers for single-family and condominium construction. Among these, the adverse effect caused by the reduction in the efficiency of the pasting work becomes larger in business applications where it is necessary to continuously paste the shoji paper on the bar in a limited space.

For the improvement, a method of increasing the diameter of the roll paper tube of commercial shoji paper to weaken the winding habit is used. However, when doing so, the amount of winding per roll is reduced, which causes a problem of reducing the efficiency of manufacturing, transporting and pasting shoji paper.
JP 2004-162231 A

  The present invention has been made to solve the above-described problems of the prior art, and specifically, an object thereof is to provide a shoji paper that is weak in curl and excellent in strength.

As a result of intensive studies, the present inventor has found that the above-mentioned problems can be achieved by using a polyolefin composite binder fiber in a mixed manner, and has reached the present invention.
That is, the shoji paper of the present invention is characterized by including a polyolefin-based composite binder fiber.

According to the present invention, in the above, it is preferable to contain 15% or more of the polyolefin-based composite binder fiber by mass ratio.
According to the invention, in the above, it is preferable that the polyolefin-based composite binder fiber is a composite fiber having a core-sheath structure in which polyolefin is a sheath component and polyester is a core component.

  The shoji paper of the present invention contains a polyolefin composite binder fiber, and is particularly a blend of 15% or more of a polyolefin composite binder fiber by mass ratio. Therefore, when sticking the shoji paper to the crosspiece, it is possible to prevent the problem that the shoji paper is peeled off from the crosspiece due to the warping until the adhesive is solidified and completely sticking to the crosspiece. . Therefore, it can be suitably used even for household shoji paper, not to mention for business use, in which the shoji paper needs to be continuously pasted to the cross in a limited space. Further, the strength of the shoji paper can be set to a level that is sufficiently practical.

  The shoji paper of the present invention includes a main material such as pulp for constituting the original paper of shoji paper and a polyolefin-based composite binder fiber for making paper by joining fibers of the main material such as pulp together.

  The polyolefin-based composite binder fiber used in the shoji paper of the present invention is preferably a composite fiber having a cross-sectional structure of a core-sheath structure in which polyolefin is a sheath component and polyester is a core component.

  Here, as the polyolefin of the sheath component, polyethylene, polypropylene, and a copolymer mainly composed of these (for example, linear low density polyethylene copolymerized with α-olefin), or a mixture of the above-mentioned polymers are used. Preferably used.

  As the polyester of the core component, those having a melting point higher by 20 ° C. or more than the polyolefin of the sheath component are preferably used. When the difference in melting point between the core component and the sheath component is less than 20 ° C., not only the sheath component that is the adhesive component but also the core component melts and shrinks at the time of thermal bonding for causing the binder fiber to exhibit the binder function. The shoji paper is not well formed.

  Specific examples of such polyesters include polyethylene terephthalate, polybutylene terephthalate, copolymers based on these, and mixtures of the aforementioned polymers.

  The core / sheath composite ratio is desirably a ratio of the sheath component (polyolefin) / core component (polyester) = 70/30% to 40/60% in terms of mass ratio because of the adhesive strength.

  As a cross-sectional form of the polyolefin-based composite binder fiber in the present invention, an appropriate form other than the above-described core-sheath type, for example, a multi-core type (sea island type) can be adopted. In the case of the multi-core type, the polyolefin constitutes the sea part and the polyester constitutes a plurality of island parts. However, in the case of the multi-core type (sea-island type), the sea part and the island part are easily separated at the time of stretching, and when the separation occurs, the formation of the shoji paper may be deteriorated.

  Next, the manufacturing method of polyolefin-type composite binder fiber is demonstrated. The polyolefin-based composite binder fiber in the present invention can be produced by a conventional fiber production process using polyolefin and polyester. That is, for example, a composite spinning nozzle is used in which a polyolefin component as a binder component forms a sheath component and a polyester component as a fiber forming component forms a core component, and the polymer stream discharged from the spinning nozzle is cooled. The undrawn yarn obtained by applying the wind is used as a tow, and the tow is heat-treated with 80 to 150 ° C steam in a stretched state, and then 0.1 to 0.10 using a cooling drum of 40 ° C or less. It can be produced by cooling for ~ 3 seconds, applying crimps as necessary, and cutting to a predetermined length.

  When the temperature of the steam is too low, orientation crystallization is difficult to proceed, the thermal shrinkage rate of the obtained composite binder fiber becomes large, and the formation of the shoji paper becomes poor. On the other hand, when the steam temperature is too high, the sheath component polyolefin is fused, and yarn breakage tends to occur frequently. On the other hand, if the steam treatment time is too short, the treatment effect is practically not exhibited. On the other hand, if the steam treatment time is too long, the fiber becomes hard.

  The steam-treated fiber needs to be promptly cooled, and cooling with a drum is efficient as described above. When cooling using a drum, the fiber tends to be hard unless the above cooling conditions are satisfied.

  In the shoji paper of the present invention, the blending ratio of the polyolefin-based composite binder fiber is preferably 15% or more by mass ratio, and more preferably 20% or more. This is because the strength of shoji paper is generally evaluated by bursting strength, but in the case of shoji paper having sufficient strength, if the blend rate of the polyolefin-based composite binder fiber is less than 15%, a large amount of polyester-based composite binder fiber Therefore, the winding habit when unrolled from the roll paper tube becomes stronger due to the effect, and when the shoji paper is pasted on the crosspiece, the adhesive is solidified and the shoji paper is completely on the crosspiece Before sticking, the problem arises that the shoji paper peels off from the crosspiece due to the warpage.

  It is possible to make shoji paper with weak curl even if the blending ratio of the polyolefin-based composite binder fiber is less than 15%, but in that case, sufficient strength cannot be obtained, which is not practical.

  The blending rate of the polyolefin-based composite binder fiber of the present invention is preferably 15% or more as described above, but the blending rate is preferably 70% or less, more preferably 60% or less. Is preferred. In the case of blending with pulp used in many types of shoji paper, if the blending ratio of the polyolefin-based composite binder fiber exceeds 70%, the natural texture of the pulp is poor, and the conventional shoji paper This is because it is often distant from the image.

  In addition to the polyolefin-based composite binder fibers, conventionally known polyester-based composite binder fibers can be blended with the shoji paper of the present invention for the purpose of improving strength. As this polyester-based composite binder fiber, a conventionally known polyester-based binder composite fiber as described in Patent Document 1, for example, polyethylene terephthalate-based polyester as a core component, terephthalic acid, isophthalic acid, ethylene glycol and A core-sheath type polyester composite binder fiber having an amorphous copolymer polyester composed of diethylene glycol as a sheath component can be used.

  It is also suitable to blend 5 to 15% of the polyvinyl alcohol-based binder fiber by mass ratio, which not only ensures the wet strength in the paper making process and improves the process passability, but also the finished shoji paper. Has the effect of improving strength. This is presumably due to the effect of strengthening the bond between pulps or between pulp and binder fibers.

  As described above, when using a polyester-based composite binder fiber and / or a polyvinyl alcohol-based binder fiber in addition to the polyolefin-based composite binder fiber, in order to maintain the natural material feeling of the pulp, the blending rate of these binder fibers Is preferably 70% or less.

  The shoji paper of the present invention can be manufactured, for example, as follows. That is, pulp, polyolefin-based composite binder fibers, and polyester-based composite binder fibers or polyvinyl alcohol binder fibers as necessary are prepared, mixed at a predetermined mass ratio, and stirred in water using a disaggregator. It can be manufactured by dispersing and then making paper, and then drying at a predetermined temperature. At this time, the polyolefin-based composite binder fiber and the like are softened and melted during the drying process at the above-described predetermined temperature, thereby exhibiting the binder function to join the pulps together, thereby forming the shoji paper.

  Next, the present invention will be specifically described with reference to examples. In addition, the measuring method of the characteristic value in a following example and a comparative example is as follows.

(A) Mass per unit area The mass of a 20 cm square papermaking sample was measured using an electronic tray electronic balance, and the value obtained by dividing the value by the area of the papermaking sample was regarded as the basis weight.

(B) Thickness Using a thickness measuring instrument manufactured by Daiei Chemical Seiki Seisakusho, the thickness was defined by an average value (number of samples: N = 5) of thicknesses measured by applying a load of 4.4 cN / cm ² .

(C) Burst strength Specified by the average value (number of samples: N = 5) of the values measured by the method shown in JIS-P-8112.

(D) Winding amount Defined by the average value (number of samples: N = 5) of the values measured by the following method.
-A paper sample (20 cm square) is wrapped around a 1 inch paper tube (outer diameter 30 mm) and left at 30 ° C. for 24 hours.
・ After that, leave it at room temperature for 4 days.
-After standing, measure the amount of warping when released from the paper tube (the length from the edge of the sample to the desk surface when the warped sample is placed on the desk).
・ Measurement is impossible when returning to a state where the degree of warping is strong and wound around a paper tube.

Example 1
Unitica Fiber Co., Ltd., part number <6080>, 1.7 dtex, 5 mm (core component: polyethylene terephthalate, sheath component; polyethylene, core-sheath composite ratio (mass ratio); sheath component / core component = 40 / 40%) manufactured by Unitika Fiber as polyester-based composite binder fiber, 1.1 dtex, 5 mm (core component: polyethylene terephthalate, sheath component; copolymer polyester, core-sheath composite ratio (mass ratio); sheath Component / core component = 50/50%), manufactured by Unitika Ltd. as a polyvinyl alcohol binder fiber, product number <SML>, 1.1 dtex, 3 mm, and “NBKP”, which is a pulp, in a mass ratio of 40/10/10 Cotton blended at 40%. And after making paper after stirring and dispersing in water using a disaggregator, drying at 140 ° C. using a Yankee dryer, shoji paper formed with a wet papermaking nonwoven fabric having a basis weight and thickness shown in Table 1 Obtained. The results of measuring the bursting strength and amount of curl of this shoji paper and the evaluation thereof are as shown in Table 2.

(Example 2)
The mixed cotton mass ratio of polyolefin composite binder fiber, polyester composite binder fiber, polyvinyl alcohol binder fiber and pulp was 20/30/10/40%. And other than that was carried out similarly to Example 1, and obtained the shoji paper formed with the wet weight papermaking nonwoven fabric of the fabric weight of Table 1 and thickness. The results of measuring the bursting strength and amount of curl of this shoji paper and the evaluation thereof are as shown in Table 2.

(Example 3)
The mixed cotton mass ratio of the polyolefin-based composite binder fiber, the polyester-based composite binder fiber, the polyvinyl alcohol binder fiber, and the pulp was set to 50/0/10/40%. And other than that was carried out similarly to Example 1, and obtained the shoji paper formed with the wet weight papermaking nonwoven fabric of the fabric weight of Table 1 and thickness. The results of measuring the bursting strength and amount of curl of this shoji paper and the evaluation thereof are as shown in Table 2.

(Comparative Example 1)
The mixed cotton mass ratio of the polyolefin-based composite binder fiber, the polyester-based composite binder fiber, the polyvinyl alcohol binder fiber, and the pulp was set to 50/0/10/40%. That is, no polyolefin composite binder fiber was used. And other than that was carried out similarly to Example 1, and obtained the shoji paper formed with the wet weight papermaking nonwoven fabric of the fabric weight of Table 1 and thickness. The results of measuring the bursting strength and amount of curl of this shoji paper and the evaluation thereof are as shown in Table 2.

(Comparative Example 2)
The mixed cotton mass ratio of the polyolefin-based composite binder fiber, the polyester-based composite binder fiber, the polyvinyl alcohol binder fiber, and the pulp was set to 10/0/50/40%. That is, the mixed cotton mass ratio of the polyolefin-based composite binder fiber was set to 10%, which was less than the preferred range in the present invention. In addition, the polyester type composite binder fiber which can contribute to the improvement of the strength of shoji paper was not included. And other than that was carried out similarly to Example 1, and obtained the wet weight papermaking nonwoven fabric of the fabric weight of Table 1 and thickness. The results of measuring the bursting strength and amount of curl of this shoji paper and the evaluation thereof are as shown in Table 2.

  When Examples 1 to 3 were compared with Comparative Example 1, it was confirmed that the winding habit was weak. This is the effect of blending 15% or more of the polyolefin composite binder fiber. The strength of Examples 1 to 3 was lower than that of Comparative Example 1, but greatly exceeded practical levels, and it was confirmed that the strength was excellent. In Comparative Example 2, the winding habit was weak even when the blend ratio of the polyolefin-based composite binder fiber was less than 15%, but the strength was low. That is, it was confirmed that it was necessary to blend 15% or more of a polyolefin-based composite binder fiber in order to obtain a shoji paper satisfying both characteristic values of winding and strength.

Claims (3)

  A shoji paper comprising a polyolefin-based composite binder fiber.   The shoji paper according to claim 1, comprising a polyolefin composite binder fiber in a mass ratio of 15% or more.   3. The shoji paper according to claim 1, wherein the polyolefin-based composite binder fiber is a composite fiber having a core-sheath structure in which polyolefin is a sheath component and polyester is a core component.