JP2555177B2 - Bulky paper and manufacturing method thereof - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention is used for surface materials, interlinings, base cloths or packaging materials for sanitary products and sanitary materials, and has bulkiness, flexibility, uniformity of texture and The present invention relates to a paper having excellent stretchability and a method for producing the paper at low cost by a highly productive papermaking method.

(Prior Art) A wet non-woven fabric is a so-called paper-making method for producing paper, as opposed to a dry non-woven fabric, and mainly paper or Japanese paper using cellulose pulp or bast fiber as a main raw material. The manufacturing method, natural fibers or regenerated fibers typified by pulp, synthetic fibers and the like and from a mixed slurry liquid of binder fibers, long-mesh, cylinder, short-mesh, etc., to fabricate the fibers on a felt, It is produced by drying this wet paper with a Yankee type or a multi-cylinder dryer. The paper obtained by this method mainly has high tenacity (bulk specific gravity), high tensile strength, and excellent printability and no fluff. On the contrary, soft tissue paper and toilet paper, which are less tight, are also produced by reducing the thickness of the paper. However, in the papermaking method, the fibers have to be two-dimensionally oriented in order to form a sheet, and the bulkiness (bulk specific gravity of 0.22 or less) having essentially three-dimensionality has not been obtained yet. The only method currently used as a means for imparting apparent bulkiness is a method of imparting bulkiness and flexibility by mechanically creping or embossing to perform a three-dimensional treatment. However, this method lacks three-dimensionality inside the sheet, and does not improve the original bulkiness and stretchability. However, according to the wet papermaking method, inexpensive cellulose pulp, bast fiber, waste paper and the like can be used to produce a paper having a basis weight of about 10 to 50 g / m ^{2 at} a speed of about 100 to several thousand meters per minute, which is a high productivity. Therefore, it can be said that this is an extremely excellent method.

On the other hand, in recent years, short fibers such as recycled fibers and synthetic fibers having crimps of about 20 to 60 mm are used and formed into a sheet-like web with a carding machine, and then the fibers and the fibers are entangled by needle punching or water flow. Nonwoven fabrics are manufactured by a so-called dry method in which they are combined, bonded with an adhesive, or mixed with a heat-fusible binder fiber and bonded by heat. For such a dry non-woven fabric, it is necessary to use fibers having a relatively long fiber length as compared with the wet papermaking method, that is, relatively inexpensive raw materials having a short fiber length such as cellulose pulp and bast fibers cannot be used, and There is a constraint that crimped fibers must be used in the production process.
However, the non-woven sheet is very flexible, bulky, and has high tear strength, and therefore has very good properties when used. However, the productivity is extremely low compared to the wet papermaking method because it involves the work of making a web from cards, and there is a problem in economic efficiency.Furthermore, since the sheets are generally arranged in the machine direction, the strength in the width direction is high. Extremely inferior,
Since the card is made into a non-woven fabric, the unevenness of the sheet texture is high, and there are problems such as the occurrence of troubles such as nep and unopened defects.

A dry method using pulp is also known.For example, a sheet in which fibers are transferred and laminated by air using a special disintegrator and bonded with a latex binder is Mr. Dobayashi's non-woven technology workshop text page 27 (62.2. No. 27 in Osaka), and it is also introduced and sold in Nonwovens Information (62.5.10.14-18 pages).
However, this method has drawbacks in that it requires a very special device in terms of production, the production speed is slow, and the strength of the obtained sheet is low.

The present inventors originally used water as a medium by utilizing the fact that they have the ability to mix with all natural, recycled and synthetic fibers, which is a major feature of the wet papermaking method using a special polyester composite fiber. When using the sheet formation, the degree of freedom between fibers is impaired, and the fatal disadvantage that only tight sheets, that is, paper-like products can be obtained, is eliminated, and high productivity and economic efficiency are provided, and bulkiness is increased. The present invention has been arrived at by noting that a sheet having a high degree of flexibility may be obtained.

(Problems to be Solved by the Invention) As described above, the wet papermaking method, which has the feature that it is possible to mix all other fibers such as cellulose pulp that can be obtained anywhere, is highly economical and highly productive. Although it is a manufacturing method, this method does not currently provide bulky and flexible paper. In this manufacturing method, a method of using crimped synthetic fibers can be considered to obtain bulkiness, but if fibers with a high number of crimps are used to obtain high bulkiness, the entanglement of single fibers It becomes a thread ball and uniform dispersibility cannot be obtained. Even if dispersion is possible, the fibers will be arranged in a plane when the paper is made, and the bulk will be crushed by hot pressing with a Yankee dryer or a multi-cylinder dryer, so that sufficient bulkiness cannot be obtained. Further, if the fibers to be mixed are cellulose pulp, there is a problem that further bulkiness cannot be obtained.

Further, in forming a sheet, there are restrictions on the binder to be used, and it is necessary to select a binder that does not impair flexibility and bulkiness and has good process passability. Although polyvinyl alcohol-based powder or fibrous binder is used for wet papermaking, the binder resin after drying is hard and there is a problem in providing bulkiness and flexibility.

(Means for Solving the Problems) That is, according to the present invention, the main component is an ethylene terephthalate unit, and 1 to 6 mol% of isophthalic acid having a metal sulfonate group and 4 to 8 mol% of isophthalic acid are copolymerized. 30% by weight or more of an eccentric core-sheath type or side-by-side type polyester composite fiber composed of a high-quality polyester (A) and a polyester (B) substantially composed of polyethylene terephthalate, and having a crimp form of spiral crimp. Contains 5% by weight or more of fusible binder fiber, and has a bulk specific gravity of 2.5 g / cm ^{2 under} load.
A bulky paper characterized by having a content of 0.06 or less, and a main component consisting of ethylene terephthalate units, copolymerized with 1 to 6 mol% of isophthalic acid having a metal sulfate group and 4 to 8 mol% of isophthalic acid. 170 of a modified polyester (A) and a polyester (B) consisting essentially of polyethylene terephthalate,
Eccentricity with a free shrinkage of 20% or less in dry heat treatment at ℃, and a latent crimping ability in which the crimped form after the dry heat treatment is spiral crimps and the number of crimps is 40/25 mm or more. 30 core-sheath or side-by-side polyester composite fibers
A bulky paper characterized in that a wet paper is made from an aqueous dispersion of a fiber mixture containing 5% by weight or more of binder fiber that is heat-fused at a weight% or more and 200 ° C or less and heat-treated at 130 to 180 ° C. It is a manufacturing method.

The conjugate fiber used in the present invention is composed of two types of polyester polymers, and the main component of the polyester polymer component (A) on the heat-shrinkable side is an ethylene terephthalate unit and a copolymer component. 1 to 6 isophthalic acid having a metal sulfonate group as
A modified polyester obtained by copolymerizing mol% with isophthalic acid in an amount of 4 to 8 mol% is used, while a polyester consisting essentially of polyethylene terephthalate is used as the polyester polymer component (B) on the heat low shrinkage side, and these two types are used. Of the polyester polymer of eccentric core-sheath type or side-by-side type composite spinning, wherein the free shrinkage in dry heat treatment at 170 ° C. is 20% or less, and the crimped form after the dry heat treatment is spiral crimping. It has latent crimping ability to express crimps of 40 crimps / 25 mm or more, and has a fineness of 1 before heat treatment.
~ 6 denier, crimp number 0 ~ 20 / 25mm, fiber length 3 ~ 20mm
30% by weight or more of the polyester conjugate fiber, which is, and a fiber made of a thermoplastic polymer having a heat-sealing temperature of 200 ° C. or less, or a core-sheath type conjugate fiber whose surface portion is covered with the polymer, fineness 1 to 6 denier , Fiber length 3 ~ 20mm, crimp number 0
5% by weight of heat-fusible binder fiber having 20/25 mm
As mentioned above, and if necessary, selected from natural fibers such as cellulose pulp, bast fibers, regenerated fibers such as rayon, polyester fibers, polyamide fibers, polyacrylonitrile fibers, polyolefin resins, polyvinyl alcohol resins, polyvinyl chloride fibers, and the like. In addition, one or more kinds of fibers, of which recycled fibers and synthetic fibers having a fineness of 0.2 to 6 denier, a crimp number of 0 to 20/25 mm, and a fiber length of 3 to 20 mm are mixed and dispersed in water. Liquid-free, long-meshed, short-meshed, circular-meshed by wet papermaking, dried and heat-treated in air at 130 to 180 ° C to obtain bulky paper with a bulk specific gravity of 0.06 or less at 2.5 g / cm ² load. I will get it. When the bulk specific gravity under a load of 2.5 g / cm ² is more than 0.06, the softness, which is the object of the present invention, is excellent, and a paper without a paper-like feel cannot be obtained.

In the polyester composite fiber having latent crimping ability used in the present invention, the polymer component (A) on the high heat shrinkage side is
Preferably, the repeating main constituent unit is ethylene terephthalate, and 1 to 6 mol% of isophthalic acid having a metal sulfonate group as a copolymer component and 4 to 8 mol% of isophthalic acid are contained. It is a modified polyester. Without copolymerizing isophthalic acid,
The polymerization reaction of polyester is appropriately advanced, and a polyester conjugate fiber having a latent crimping ability within the range of the present invention can be produced, but it is preferable to copolymerize isophthalic acid in order to further increase the bulkiness of the paper. . On the other hand, when the isophthalic acid content exceeds 10 mol%, it becomes difficult to stably obtain a proper degree of polymerization, and the crimp fastness is remarkably reduced. Further, isophthalic acid having a metal sulfonate group to be copolymerized is used to keep the melt viscosity at an appropriate level and to make latent crimp development capability manifest within the scope of the present invention. Examples of the isophthalic acid having a metal sulfonate group in the present invention include 5-sodium sulfoisophthalic acid, 5-potassium sulfoisophthalic acid, and 5-lithium sulfoisophthalic acid. An ester-forming compound having a metal sulfonate group such as an ester-forming derivative is added in a range of 1 to 6 mol% when polyethylene terephthalate is polymerized, and the above-mentioned isophthalic acid is added and copolymerized as necessary. (A) is obtained. In addition to this, a polyethylene terephthalate polymer in which a high proportion of isophthalic acid having a metal sulfonate group is copolymerized is prepared in advance, and a polyethylene terephthalate polymer in which a high proportion of isophthalic acid is copolymerized is also prepared in advance. Alternatively, a master batch method or the like may be used in which these are mixed with polyethylene terephthalate so that the copolymerization ratios thereof are in the ranges of 1 to 6 mol% and 4 to 8 mol%, respectively. The copolymerization ratio of isophthalic acid having a metal sulfonate group is 1 mol%
When it is less than the range, the shrinkage stress during the heat treatment is weakly expressed, and the crimp developability is poor. When it is 6 mol% or more, the melt viscosity of the polymer becomes too high, and it becomes difficult to stably obtain a polymer having an appropriate degree of polymerization in the condensation reaction, and the crystallinity at the time of spinning becomes high, which easily causes a change over time. It is not possible to obtain a bicomponent fiber having a sufficient latent crimp property due to a decrease in drawability. It is preferably 1 to 5 mol%, and more preferably 2 to 4 mol%. Further, a copolymer component other than the above may be introduced into the polymer (A) within a range that does not significantly impair the high heat shrinkability. The intrinsic viscosity of the polymer (A) is preferably 0.45 to 0.66.

Polyester consisting essentially of polyethylene terephthalate is used as the polymer component (B) on the low heat shrinkage side. Of course, the polymer (B) may be copolymerized as long as the effect of developing the crimp of the polymer (A) is not significantly reduced. The degree of polymerization at which the intrinsic viscosity of the polymer (B) is 0.60 to 0.70 is preferable.

Inorganic substances such as titanium oxide, photo ceramics, zirconium oxide, silicon oxide, alumina, if necessary.
Alternatively, flame retardants, antibacterial agents, deodorants, fragrances, and hydrophilizing agents such as sodium dodecylbenzenesulfonate may be mixed. Further, other polymers may be added to the polymers (A) and (B) within a range that does not significantly impair the crimpability of the fiber.

The spinneret to be used may be a composite type spinneret having a hole shape such as a ○ type, a Δ type, a + type, an ∞ type, and a T type. However, the spinneret is not limited to these, and the composite form is also particularly limited. However, the side-by-side type is generally preferable to the eccentric core-sheath type because the crimp developing power is excellent.

The latently crimpable conjugate fiber used in the present invention is the above-mentioned (A),
Two polymer components of (B) were used in the range of 270 to 290 ° C. using the above-mentioned die, and a composite ratio (A) :( B) = 40 to 60:60 to 4
In the range of 0, it is particularly preferable to use eccentric core-sheath type or side-by-side type, preferably side-by-side type conjugate fiber as described above. The melt viscosities of the two polymer components during spinning are always (A)> (B), and the difference in viscosity during melting is 10
The range of 0 to 1000 poise is preferable for obtaining the composite spun fiber having excellent latent crimping ability. Composite ratio is 50: 5
The deviation from 0 is likely to cause a kneeing phenomenon in the die discharge part, so that the range of (A) :( B) = 45 to 55:55 to 45 is most preferable. The melt viscosity is a value at about 285 ° C.

Next, the latent crimpable conjugate fiber constituting the paper having bulkiness, flexibility, stretchability, and elongation recovery property should have a spiral crimp after heat treatment to improve the bulkiness, flexibility, and stretchability of the paper of the present invention. It is important to impart, and it is important that the number of spiral crimps and the shape (curvature) of the crimps at that time are sharp. Specifically, the number of crimps is 4 by dry heat treatment at 170 ° C.
It is preferable that a spiral crimp is developed at 0/25 mm or more. When the number of crimps is less than 40/25 mm, the bulkiness, flexibility and stretchability are significantly reduced, and the paper has a high bulk specific gravity. Also, the shrinkage factor during heat treatment has important relationships with the texture, bulkiness and stretchability of the paper, and the general processing conditions are preset temperature of 160-180 ° C and final drying heat treatment temperature of the paper.
When 170 ° C. is selected as a representative temperature satisfying 130 to 180 ° C. and the shrinkage percentage when the fiber is subjected to free shrink heat treatment at 170 ° C. is 20% or less, these items are sufficiently satisfied. Shrinkage rate is 20
When the content is more than 100%, the paper becomes hard and the crimping property, particularly the crimping fastness is lowered, and the durability is lowered.

The crimpable conjugate fiber having such latent crimping ability and heat shrinkability has an intrinsic viscosity of the polymer (A) on the high heat shrinkage side and the polymer (B) on the low shrinkage side, and the polymer ( It is obtained by appropriately selecting the copolymerization ratio of isophthalic acid and isophthalic acid having a metal sulfonate group of A), the composite ratio of (A) and (B), and the stretching conditions and tension heat treatment conditions in the stretching process after spinning. To be As for the drawing conditions, the latent crimping capacity can be maximized by drawing at 60 to 75% of the maximum draw ratio of the fiber after spinning. In this state, the tension heat treatment should be performed in the range of 130 to 180 ° C. Due to
High crystallinity can be maintained, and a high latent crimping force is cultivated.

Further, as the latent crimpable conjugate fiber, it is usual to use an uncrimped fiber for wet papermaking, but in order to further improve the crimpability, an indentation type crimping machine which is a general method is used to disperse it in water. Mechanical crimp, number of crimps 3 to 20
It may be raw cotton with a thickness of 25 mm. 20/25 crimps
If it exceeds mm, disaggregation is not sufficiently performed by a heater or a pulper, which is not preferable. The latent crimpable polyester conjugate fiber has a fineness of 1 to 15 denier, more preferably 2 to 6
Denier. If it is less than 1 denier, the spiral crimp developability is good, but the crimp developability is weak, bulkiness is difficult to be obtained, and the spinnability is deteriorated, so that a stable yarn cannot be obtained. Further, in the area exceeding 15 denier, it becomes stiff and lacks flexibility, which is not preferable. The fiber length is preferably 3 to 20 mm because it is effectively dispersed in water for wet papermaking and the crimp developability is effective, and particularly 4
~ 10 mm is preferred. When it is 3 mm or less, the dispersibility in water is good, but the fibers become short, which causes the generation of fluff and paper dust, which is not preferable. If it exceeds 20 mm, the dispersibility of the fibers will be poor and the fibers will become flocculated, making it difficult to obtain uniform paper.

Further, when the addition rate of the latently crimpable polyester conjugate fiber of the present invention is less than 30% by weight, each fiber has crimp expression, but it is mixed with a heat-fusible binder fiber or other fiber to obtain crimp expression by heat treatment. However, a stress expression that overcomes the constraint of other added fibers cannot be obtained. Therefore, 30% by weight or more is necessary, and preferably 50% by weight or more. Further, a surface-treating oil agent may be added during the manufacturing process in order to improve the dispersibility in water.

In order to effectively develop the latent crimp property, a heat treatment method that does not apply force in the paper making direction or the thickness direction of the paper is preferable. For example, a method of blowing hot air of 140 to 180 ° C. on a sheet on an endless wire mesh or a method of passing through a through dryer is conceivable, but a Yankee type or a multi-cylinder type may be used and is not limited to the device.

The heat-fusible binder fiber is a mixture of latently crimpable polyester composite fiber and optionally used natural fiber, regenerated fiber or synthetic fiber. It has a role of effectively adhering each fiber in the shrinking step. That is, heat fusion may be performed in a dryer part at 90 to 130 ° C., or pseudo bonding may be performed. Further, it is preferable that the fibers are bonded to each other by heat fusion at the same time when the crimps are generated by heat treatment at 130 to 180 ° C. From these facts, it is a necessary condition that the heat fusion temperature is 200 ° C. or lower from the viewpoint of the heat fusion property and the heat treatment temperature of the latently crimpable polyester composite fiber. When the temperature is higher than 200 ° C., heat fusion causes a decrease in the performance of the latently crimpable polyester conjugate fiber, which is not preferable.

The heat-fusible binder is not preferable because it cannot obtain flexibility unless it is a fiber made of a thermoplastic polymer. Preferred are polyolefin fibers such as polyethylene and polypropylene, or fibers made of polyester or polyamide having a low melting point or a low softening point by copolymerization. Naturally, a core-sheath type composite fiber covered with the polymer can also be used. In this case, as the core component, an unmodified polyester-based polymer, polypropylene-based polymer, polyamide-based polymer or the like is used.

The heat-fusible binder fiber used is preferably from 1 to 15 denier, and when it is less than 1 denier, the dispersibility in water is poor, which is not preferable, and when it exceeds 15 denier, the binder effect is reduced and the texture of the paper is deteriorated. Is not preferable. Regarding the number of crimps, it is preferable to use uncrimped ones in order to obtain water dispersibility, but in order to improve bulkiness during heat treatment, 20/25 mm or less crimps in a range not impairing water dispersibility You may give contraction. If the number of crimps exceeds 20/25 mm, the yarn will be entangled when dispersed in water, which is not preferable.

The addition rate of the heat-fusible binder fiber needs to be 5% by weight or more, and preferably 10 to 40% by weight. If it is less than 5% by weight, it exhibits an effect on paper strength and stretch recovery when a latent crimpable polyester conjugate fiber and natural fiber, regenerated fiber or synthetic fiber used in the present invention are mixed, and prevention of fluff appearing on the paper surface. Absent.

Next, as other fibers to be used in the present invention, softwood which is a natural fiber, unbleached or bleached pulp from hardwood, kozo,
Mitsumata, bast fibers such as hemp and ramie, plant fibers from Kotton linter, bamboo, and straw can also be used. Recycled pulp or waste paper may be used. These may be unbeaten pulp, or may be beaten to have a Canadian freeness of about 100 to 750 ml. The use of these natural fibers brings the advantage that the paper obtained as represented by Western paper and Japanese paper has excellent printability and is strong. Furthermore, it has the features of high affinity with water, high absorption rate, and high water absorption. It also has excellent economic efficiency. As described above, an object of the present invention is to obtain a product having a performance like a dry non-woven fabric even though it has a form and a manufacturing method like paper. In the present invention, a mixed pulp of cellulose pulp is obtained by high-speed papermaking and heat treatment to obtain a dry nonwoven fabric having the texture and characteristics of paper. That is,
It is one of the added fibers for exhibiting papermaking properties and water absorption of the product.

The following regenerated fibers are represented by rayon obtained from viscose, but when regenerated fibers are used, they are superior in bulkiness to the conventionally produced rayon paper, and have the hydrophilicity and paper-making property of rayon. It is possible to obtain a stretchable paper having good flexibility and texture.

Next, synthetic fibers are added fibers. Synthetic fibers such as polyester fibers, polyolefin fibers, polyamide fibers, polyacrylonitrile fibers, and polyvinyl chloride fibers impart flexibility and bulkiness and improve the texture. Further, the polyvinyl alcohol-based synthetic fiber can be used as one for strengthening the stiffness of paper and one for enhancing hydrophilicity.

Regenerated fibers and synthetic fibers preferably have a fineness of 0.2 to 15 denier. If it is less than 0.2 denier, the dispersibility in water is poor and pills are easily formed. On the other hand, when it exceeds 15 denier, the obtained paper becomes stiff and hard, and the flexibility becomes insufficient. The number of crimps of the fiber is preferably uncrimped in consideration of dispersibility in water, but within a range not impairing dispersibility,
20 pieces / 25m to add bulkiness, flexibility and elasticity
A crimp of m or less may be given. When the number of crimps is 20/25 mm or more, the dispersibility in water of the fiber is deteriorated and a ball shape is unfavorable. The fiber length is preferably 2 to 20 mm, more preferably 3 to 10
mm. If it is less than 2 mm, the dispersibility in water is good, but the fibers are short, so that fuzz or paper dust is generated. On the other hand, if it exceeds 20 mm, the dispersibility in water becomes poor, and it becomes difficult to obtain a uniform texture or texture by fluffing or stringing. The cross-sectional shape of the regenerated fiber and the synthetic fiber is not limited to a circular shape, and may be a modified shape such as a flat shape, a U-shape, a Y-shape, a T-shape, a star shape, and a triangular shape. You may have a hollow part in. The fiber form may be a fibril form. In the present invention, one kind or two or more kinds of fibers selected from the group consisting of the above natural fibers, regenerated fibers and synthetic fibers can be selected and used according to the purpose.

As described above, the fiber raw material to be subjected to wet papermaking is a polyester composite fiber having a latent crimping ability and a heat-fusible binder fiber defined in the present invention, and other natural fiber, regenerated fiber, and other optional fiber added. It is essential that the fiber is composed of a fiber selected from the group consisting of synthetic fibers.

The method for producing bulky paper is as follows: 30% by weight or more of polyester composite fiber having latent crimping ability, 5% by weight or more of heat-fusible binder fiber, and if necessary, natural fiber such as cellulose pulp fiber, regenerated rayon, etc. Fiber and a fiber mixture consisting of one or more kinds of fibers selected from the group consisting of other synthetic fibers are added to water so as to form a slurry of 1 to 10% by weight, and disintegrated with a beater or a pulper to obtain a uniform mixture. Make a simple water dispersion. Furthermore, 0.5 to 5% by weight at the est
A homogeneous dispersion of fibers in water is obtained by diluting and stirring to obtain an aqueous dispersion, which is used as a papermaking stock solution. If necessary, such a slurry is transferred to a long or short net of a round net or a slanted wire through a vibrating screen or a dust removing device, and is divided by circulating white water to obtain a slurry concentration (pulp concentration in the slurry).
Make up on wire with 0.02-1% by weight. Paper making may be performed in one cylinder tank or multiple tanks. Further, paper may be made with a combination of circular net and long net or short net. Excess water is removed in advance by vacuum dehydration of the wet paper sheet made on the felt, and the wet paper sheet is transferred to a dryer. The type of the dryer may be a Yankee type or a multi-cylinder type. Preferably, the wet paper web on the rotating wire mesh is dried with hot air and heated to dry and heat at once to develop crimps. In addition to this, even in the Yankee type or multi-cylinder type, a drying temperature of 90 to 130 ° C is added to dry and roll up the wet paper,
A method of developing crimps in the heat treatment step may be used, and in the case of a continuous step, a method of passing a heat treatment step for developing crimps after the drying step may be used. The heat treatment step requires a temperature of 130 to 180 ° C. and is preferably a hot air type in which hot air penetrates the paper layer, but a heat radiation type, a heat roll, or a hot plate bonding method may be used. In order to obtain preferable bulkiness and flexibility, it is preferable to avoid applying tension in the paper-making direction, the width direction and the thickness direction as much as possible, and usually it is carried out under the tension sufficient to move the paper. The high-bulk paper that has undergone the heat treatment step and has been crimp-developed is usually passed through a hot roll of 130 to 200 ° C. at regular intervals for the purpose of smoothing its surface and fluffing. Moreover, you may give embossing for patterning and strength improvement. The bulky paper is cooled and wound under tension sufficient for winding.

Hereinafter, specific examples of these will be described in Examples and Comparative Examples. In Examples and Comparative Examples,% is a value based on weight.

Reference Example 1 As a polymer component (A), a modified polyester having ethylene terephthalate as a main component and 2.0 mol% of 5-sodium sulfoisophthalic acid copolymerized with an intrinsic viscosity of 0.55 is used.
As a polymer component (B), a polyester having an intrinsic viscosity of 0.65 consisting essentially of ethylene terephthalate units was used, and a composite-by-spinning apparatus was used to make a side-by-side type with a composite ratio of 50:50 at a round cross-section spinneret hole of 285 ° C. It was wound at a discharge rate of min and a speed of 1150 m / min to obtain an undrawn yarn of cable denier 2700. Draw ratio of these undrawn yarns
It was stretched 2.4 times at a stretching temperature of 75 ° C and heat-treated at a tension heat treatment temperature of 150 ° C to obtain a straight latent crimped fiber having a single fiber fineness of 2.4 denier. This fiber had a free shrinkage rate of 8% in a dry heat treatment at 170 ° C. and a crimp number of 53/25 mm.
The latent crimpable fiber was cut into a fiber length of 5 mm to prepare a raw material for papermaking.

Reference Example 2 Intrinsic viscosity obtained by copolymerizing terephthalic acid as a main dicarboxylic acid component as a polymer component (A) with 5 mol% of isophthalic acid and 2.5 mol% of 5-naphtholiumsulfoisophthalic acid
A modified polyester of 0.45 was used, and a polymer having an intrinsic viscosity of 0.60 consisting essentially of ethylene terephthalate units was used as the polymer component (B). : 50 side-by-side type, a discharge rate of 345 g / min and a winding rate of 1150 m / min were obtained, and an undrawn yarn of cable denier 2700 was obtained.
After converging these undrawn yarns, draw ratio 2.5 times, draw temperature 7
Stretching was carried out at 0 ° C, and heat treatment was carried out at a tension heat treatment temperature of 145 ° C to obtain straight latent crimped fibers having a single fiber fineness of 2.5 denier.

The free shrinkage of this fiber by dry heat treatment at 170 ℃ is 7.5.
%, The number of crimps was 60/25 mm. The latent crimpable fiber was cut into a fiber length of 5 mm to obtain a papermaking raw material.

Examples 1 to 3 and Comparative Examples 1 to 4 Latent crimpable polyester composite fibers obtained in Reference Examples 1 and 2, heat-fusible binder fibers, and Examples 1 to 3 showing the cellulose pulp fibers in Table-1. The formulations of Comparative Examples 1 to 4 were simultaneously disaggregated by a TAPPI standard disintegrator at a concentration of 2 g / l for 300 counts. Further, it was diluted to 0.2 g / l, and the slurry was sampled with a TAPPI standard square paper machine so that the target rice basis weight was 40 g / m ² and paper was made. Wet paper is dried at 70 ℃ for 1 minute and then 170 ℃
Heat treatment was carried out for 4 minutes on the wire net in the air dryer to obtain a crimped bulky paper.

 The heat-bonding binder fiber used was melted at 130 ° C at the sheath.
Modified polyester to wear and the core is normal polyester
Composite fiber made of fibers [Kuraray Softsoft Co., Ltd. N-
720 is fiber 2 denier, fiber length 5 mm]. See cellulo
Softwood pulp is an unbleached softwood pulp that has not been beaten.

In the obtained bulky paper, the latent crimpable polyester conjugate fiber was spiral crimped.

Examples 1 to 3 are related to the present invention, and have bulk specific gravity of 0.22 or less, bulky papers are obtained, and the performances of bending resistance and liquid absorption are also satisfied. Comparative Examples 2 to 4 are regions outside the scope of the present invention. In both cases, the bulk specific gravity is high as compared with the examples, which is not preferable for paper performance. Examples 4-9 and Comparative Examples 5-8
The latent crimpable polyester fiber, the heat-fusible binder fiber, the various polyester fibers and rayon obtained in Reference Example 2 were weighed with the formulations of Examples 4 to 9 and Comparative Examples 5 to 8 shown in Table 2 and, at the same time, TAPPI. It was charged into a standard disintegrator at a concentration of 2 g / l and disaggregated for 300 counts to obtain a water-dispersed slurry. Furthermore, the paper was made to a target rice basis weight of 40 g / m ² using a TAPPI standard square paper machine. Wet paper is dried at 70 ℃ for 1 minute, then 17
Heat treatment was performed for 4 minutes on a wire net in an air dryer at 0 ° C. to obtain crimped bulky paper.

 The heat-fusible binder fibers are the same as in Examples 1 to 3 and Comparative Example
Kuraray soft fittings used in Examples 2-4 Same as N-720
is there. The polyester fibers used are as follows:
You.

As rayon, rayon manufactured by Daiwabo Co., Ltd., SD 1.5 denier, fiber length 5 mm, and no crimp was used.

In the bulky paper obtained, the latently crimpable polyester conjugate fiber had a spiral crimp.

Examples 4 to 9 have the features of bulkiness and flexibility of the present invention, and the amount of water and oil absorbed reaches 20 to 30 times that of paper. Comparative Examples 5, 6 and 8 have a small amount of the heat-fusible binder fiber, the strength of the base paper is low and cannot be handled, and the paper after dry heat treatment at 170 ° C. also develops crimp but has low paper strength Nakatsuta.

Example 10 As Example 10, the latent crimpable polyester fiber 40% obtained in Reference Example 2 and the heat-fusible binder fiber 20% and polyester fiber EPO43 × 5 40% manufactured by Kuraray Co. Paper was made in the same manner as in Matsumatsu No. 9. The heat-fusible binder fiber is manufactured by Chitsso (EA-Chop 3 denier fiber length 5 m
The composite fiber of m), in which polyethylene is the sheath component and polypropylene is the core component, is used. As a result, the basis weight is 41.0 g /
m ² , thickness 0.224 mm (according to JIS P 8118), bulk specific gravity (0.180
(According to JIS P 8118), thickness under load of 2.5 g / m ² 0.821 mm,
A paper having a bulk specific gravity of 0.050 was obtained.

The tensile strength in dry and wet was 0.04 and 0.04 Km in a width of 15 mm, and the elongations were 25.3 and 23.5%, respectively. Bend is 32
Very flexible with mm, water and oil absorption of 3 g / g of paper
It showed a large liquid absorption of 3, 28 g. The feeling is ◎, which is highly flexible.

The measuring method of each characteristic value and the like in the present invention is as follows.

(1) Intrinsic viscosity: Measured at 30 ° C. in a mixed solution of phenol and ethane tetrachloride in equal weight.

(2) Fineness: Measured by the method of JIS L-1015-7-5-1A.

(3) Number of crimps: Measured by the method of JIS L-1015-7-12-1.

(3) Free shrinkage: 170 ° C according to JIS L-1015-7-15
Measured in the atmosphere for 30 minutes, applying a load of 300 mg per denier.

(5) Measurement of physical properties of paper Basis weight: JISP 8124 Bulk specific gravity: Four sheets of paper are superposed, and a plastic plate is applied to 2.5 g / cm ^2, and the thickness is measured with a micrometer.
It was calculated from the average thickness of one sheet. As another method, there is a method of measuring thickness and bulk specific gravity according to JIS P 8118. The measurement was carried out by this method in Examples and Comparative Examples.

Strength and fracture length: JIS P 8113 Stiffness: Cantilever method Liquid absorption: Water and mechanical oil were used as liquid substances. Weight of stock cut into a size of 10 cm x 10 cm (W ₀ )
To measure. Let it soak in water and machine oil for 15 minutes and confirm that the air in the stock has been replaced. Measure the weight (W ₁ ) of the stock when the stock is pulled into the air and the drop does not drop.

It is the value obtained from the above.

(6) Feeling: Sensitivity was determined as follows.

◎ Rabbit hair-like feeling (softness with sliminess) ○ 〃 (soft feeling) △ Cloth-like feeling (roughness) × Paper-like feeling (crunchiness) (effect of the invention) ) A latent crimpable polyester conjugate fiber according to the present invention, a heat-fusible binder fiber and optionally other natural fibers,
By mixing recycled fibers and rigid fibers and heat-treating,
Bulky and flexible paper can be obtained with conventional wet papermaking equipment.

In the present invention, it is possible to mix pulp and it is limited to dry non-woven fabric from the viewpoint of paper making property and economical efficiency, surface material of sanitary goods and paper diapers, wipers for household and industry, medical paper, tapes, and patch. It can be used for applications such as material base cloth, interlining, and sheet-like batting. On the other hand, as an industrial material, it is bulky and can be used as a filter, a water / oil absorbing material, a drain material, a heat insulating material, an agricultural coating material, a cushioning packaging material, and the like.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Taemaru Ezaki 1-1239 Umeda, Kita-ku, Osaka City, Osaka Prefecture Kuraray Co., Ltd. Examiner Shigemi Sawamura (56) Reference JP 1-16900 (JP) , A) JP 59-36800 (JP, A) JP 62-78214 (JP, A) JP 61-124610 (JP, A)

Claims (3)

(57) [Claims] 1. A modified polyester (A) comprising a ethylene terephthalate unit as a main component, 1 to 6 mol% of an isophthalic acid having a metal sulfonate group and 4 to 8 mol% of an isophthalic acid, and a modified polyester (A). 30% by weight or more of an eccentric core-sheath type or side-by-side type polyester composite fiber composed of polyester (B) made of polyethylene terephthalate and having a crimp form of spiral crimp, and 5% by weight of a heat-fusible binder fiber. A bulky paper containing the above and having a bulk specific gravity of 0.06 or less under a load of 2.5 g / cm ² . 2. A group consisting of natural fibers such as cellulose pulp and bast fibers, recycled fibers such as rayon, polyester fibers, polyamide fibers, polyacrylonitrile fibers, polyolefin fibers, polyvinyl alcohol resins, polyvinyl chloride fibers and the like. The high-bulk paper according to claim 1, containing one or more fibers selected from the group consisting of: 3. A modified polyester (A) comprising a ethylene terephthalate unit as a main component, wherein 1 to 6 mol% of isophthalic acid having a metal sulfonate group and 4 to 8 mol% of isophthalic acid are copolymerized, and substantially. Is composed of polyester (B) made of polyethylene terephthalate, has a free shrinkage of 20% or less in a dry heat treatment at 170 ° C., and the crimped form after the dry heat treatment is a spiral crimp.
Eccentric core-sheath type or side-by-side type polyester composite fibers having latent crimping ability to develop crimps of 40 crimps / 25 mm or more, and 5 wt. % Of the fiber mixture is added to the wet paper, and heat treatment is performed at 130 to 180 ° C. to obtain a bulky paper.