JPH02229294A - Bulky paper and production thereof - Google Patents

Abstract

PURPOSE:To obtain the bulky paper having excellent bulkiness, softness and uniformity of the fabric and useful for hygienic good, etc., at a low cost in high productivity by blending a polyester composite fiber having latent crimping properties with heat fusible binder fiber and heat-treating the blend. CONSTITUTION:Water dispersing liquid of fiber mixture containing >=30wt.% eccentric core-sheath type or side by side type polyester composite fiber having <=20% free shrinkage in dry heat treatment at 170 deg.C and having latent crimping ability expressing crimp having >=40/25mm numbers of crimp as spiral crimp in crimp form after the dry heat treatment and >=5wt.% binder fiber thermally fused at <=200 deg.C is made into a wet web and the wet web is subjected to heat treatment at 130-180 deg.C to provide the bulky paper being <=0.06 in bulk density under 2.5g/cm<2> load.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention is suitable for surface materials, interlinings, base fabrics, or packaging materials for sanitary products and sanitary materials. The present invention relates to providing paper with excellent elasticity and a method for producing this paper at low cost using a papermaking method with high productivity.

(Prior Art) In contrast to dry-processed non-woven fabrics, wet-processed non-woven fabrics are so-called paper-making methods for producing paper, and Western paper and Japanese paper using cellulose pulp or bast fibers as the main raw materials are mainly used. The manufacturing method is to produce fourdrinier from a mixed slurry of natural fibers, recycled fibers, synthetic fibers, etc. represented by pulp, and binder fibers.
The fibers are drawn onto felt using a circular mesh, short mesh, etc.
It is produced by drying wet paper with a Yankee type or multi-tube dryer. The performance of paper obtained using this method is high in tightness (bulk specific gravity). The main types are those with high tensile strength, excellent printability, and no fuzz.

Conversely, flexible tissue paper and toilet paper with low tension are produced by reducing the thickness of the paper. In the paper-making method, the fibers must be oriented two-dimensionally in order to form a sheet, and it has not been possible to obtain bulkiness (bulk specific gravity of 0.22 or less) that essentially has three-dimensionality. The only method currently used to impart apparent bulkiness is to mechanically crepe or emboss the material to give it three-dimensional properties, thereby imparting high I1 strength and flexibility. However, this method lacks three-dimensionality inside the sheet and does not improve the original bulkiness and elasticity. However, according to wet papermaking method K, inexpensive cellulose bulbs, bast fibers, waste paper, etc. are used, and the basis weight is 10 to 509.
This method has high productivity, capable of producing paper of approximately 100 m/d at a speed of approximately 100 to several thousand meters per minute, and can be said to be an extremely excellent method in this respect.

On the other hand, in recent years, short fibers such as recycled fibers and synthetic fibers with fiber lengths of about 20 to 60 cm and crimps are used, and after being made into a sheet-like web using a carding machine, the woven fibers and fibers are processed by needle bunting or water jetting. Nonwoven fabrics are manufactured by a so-called dry process, in which nonwoven fabrics are entangled with each other, bonded with an adhesive, or mixed with heat-fusible binder fibers and bonded by heat. For such dry-processed nonwoven fabrics, fibers with a relatively long fiber length must be used compared to wet-process papermaking methods.In other words, relatively inexpensive raw materials with short fiber lengths such as cellulose bulbs and bast fibers cannot be used. Furthermore, there is a restriction that crimped M fibers must be used in the production process. However, the nonwoven fabric sheet is highly flexible, bulky, and has high tear strength, so it has very good properties for the κ used. But productivity... Because it involves making a web from the card, it is extremely low compared to the wet paper making method, which poses a problem in economic efficiency.Furthermore, the strength of the resulting sheet in the width direction is extremely poor because the fibers are generally arranged in the machine direction. There are problems such as high non-uniformity of the sheet texture when rolling the material into a non-woven fabric, resulting in problems such as neps and unopened fiber defects.

A dry method using a bulp is also known, and for example, a special de-fiber machine is used to transport and laminate fibers using air, and then the sheets are glued together using a latex binder. 62.2.27, Osaka)
Non-woven fabric information (62.5.1 0.1 pages 4-18)
It was also introduced and sold in Hansai. However, this method is complicated and requires very special equipment. It has the drawbacks of slow production speed and low strength of the resulting sheet.

The present inventors used a special polyester composite fiber and took advantage of its ability to be mixed with all natural, recycled, and synthetic fibers, which is a major feature of the wet papermaking method, to originally create a paper using water as a medium. The use of sheet formation eliminates the fatal drawback that the degree of freedom between fibers is lost and only sheets with high tension, that is, paper-like sheets, can be obtained. The present invention was developed by noting that it is possible to obtain a sheet with high flexibility.

(Problems to be Solved by the Invention) As mentioned above, the wet papermaking method has the advantage of being able to mix all kinds of fibers, including cellulose pulp, which is available anywhere, and is highly economical and productive. However, paper with high bulk and flexibility cannot currently be obtained using this method. In this manufacturing method, in order to obtain bulkiness, it is possible to add crimps and use synthetic fibers, but if fibers with a high number of K crimps are used to obtain high bulkiness, the intertwining of single fibers will occur. This occurs, resulting in balls of yarn, and uniform dispersibility cannot be obtained. Even if dispersion is possible, planar K fibers may be arranged during papermaking,
The bulk is crushed by hot pressure using a Yanki dryer or a multi-barrel dryer, and sufficient bulkiness cannot be obtained. Furthermore, if the mixed fibers are cellulose bulbs, there is a problem that even higher fiber properties cannot be obtained.

Furthermore, when forming a sheet, there are restrictions on the binder that can be used, and it is necessary to select a binder that does not impair flexibility or bulk and has good processability.

Polyvinyl alcohol-based powder or fibrous binders are used in wet papermaking, but the binder resin is hard after drying, and κ, which provides bulk and flexibility, is problematic.

(Means for Solving the Problems) That is, the present invention provides eccentric core-sheath type or side-by-side type polyester composite fibers having a spiral crimp form and having a weight of 30 weight or more. The heat-fusible binder fiber is
A bulky paper containing a weight of 1 or more, a bulk specific gravity of 0.06 or less at 2.5 f/1 load, and a free shrinkage rate of 20% or less in dry heat treatment at 170 ° C. And the crimped form after the dry heat treatment is spiral crimped, and the eccentric core-sheath type or side-by-side type polyester composite fiber has a potential crimp ability of 40 crimps/25 cm or more and is 30% by weight. A method for producing bulky paper, characterized in that wet paper is made from an aqueous dispersion of a fiber mixture containing at least 5 parts by weight of binder fibers that are thermally fused at temperatures below 200°C and subjected to heat treatment at 130 to 180°C. It is.

Preferably, it is composed of two types of polyester polymers, of which the polyester polymer component on the high heat shrinkage side (
As A), a modified polyester whose main component is ethylene terephthalate units and which is obtained by copolymerizing 1 to 6 mol of inphthalic acid and 0 to 10 mol of isophthalic acid, which has a metal sulfonate group as a copolymer component, is used; As the polyester polymer component CB) on the low shrinkage side. A fiber that uses a polyester consisting essentially of polyethylene terephthalate and compositely spins these two types of polyester polymers in an eccentric core-sheath type or side-by-side type, and has a free shrinkage rate of 20% or less in dry heat treatment at 170'C. The crimp form after the dry heat treatment is a spiral crimp, which has a potential crimp ability of 40 crimp/25 crimp or more, and the fineness is 1 to 6 denier before the heat treatment. Reduction number 0-20/25W% fiber length 3-201
A core-sheath type composite fiber whose surface portion is covered with the polymer, or a fiber consisting of a polyester composite fiber with a weight of 30 weight or more and a thermoplastic polymer with a heat fusion temperature of 200 ° C or less, or a core-sheath type composite fiber whose surface portion is covered with the polymer, fR degree 1 ~ 6 denier, fiber length 3-20cm, crimp number O-20/2gfi, heat-fusible binder fiber of 5 weight or more, and if necessary, natural fibers such as cellulose bulp, bast fiber, rayon, etc. recycled fibers,
Polyester-based, polyamide-based. One or more types of fibers selected from synthetic fibers such as polyacrylonitrile, polyolefin, polyvinyl alcohol, and polyvinyl chloride, among which recycled fibers and synthetic fibers have a density of 0.2 to 6 denier. , Number of crimps: 0-20/25fi,
Fibers with a fiber length of 3 to 20 cm are mixed to form an aqueous dispersion, which is made into paper using a fourdrinier, short screen, or cylinder using a wet paper making method. After drying, the paper is heat treated in air at 130 to isoC. A bulk paper having a bulk specific gravity of 0.06 or less at the time of .5t/one load is obtained. If the bulk specific gravity exceeds 0.06 at 2.5'l/one load, paper with excellent softness K and no paper-like feel, which is the object of the present invention, cannot be obtained.

In the polyester composite fiber having latent crimp ability used in the present invention, the polymer component (A) on the high heat shrinkage side preferably has a repeating main constituent unit consisting of ethylene terephthalate, and a metal sulfide as a copolymer component. It is a modified polyester containing 1"-6 mol of isophthalic acid having 7 onate groups and 0 to 10 mol % of isophthalic acid, preferably 4 to 8 mol. Even without the use of isophthalic acid, the polymerization reaction of polyester proceeds appropriately and it is possible to produce polyester composite fibers having a latent crimp ability within the scope of the present invention. If the amount of isophthalic acid exceeds 10 mole, it becomes difficult to obtain a stable degree of polymerization with an appropriate degree of polymerization, and the crimp fastness deteriorates significantly.In addition, isophthalic acid having a metal sulfonate group to be copolymerized is It is used to keep the melt viscosity at an appropriate level and to realize the ability to develop latent crimp within the scope of the present invention.The inphthalic acid having a metal sulfonate group in the present invention K is 5-sodium sulfoisophthalic acid%5. -Calicum sulfoisophthalic acid and 5-lithium sulfoisophthalic acid.

When polymerizing polyethylene terephthalate, an ester-forming compound having a metal sulfonate group such as these ester-forming derivatives is added in a range of 1 to 6 mole, and the above-mentioned isophthalic acid is added as necessary and copolymerized to form a polymer ( A) is obtained. In addition to this, a polyethylene terephthalate polymer was prepared in advance by copolymerizing a high proportion of isophthalic acid having a metal sulfonate group, and a polyethylene terephthalate polymer was also prepared by copolymerizing a high proportion of isophthalic acid than the required K. Keep it,
They can also be obtained by a master method, etc., in which these are mixed with polyethylene terephthalate at a copolymerization ratio of 1 to 6 mol and 0 to 10 mol, respectively. If the copolymerization ratio of inphthalic acid having a metal sulfonate group is less than 1 mole, the development of shrinkage stress during heat treatment is weak and the shrinkage development property is poor. If it exceeds 6 molt, the melt viscosity of the polymer will become too high and a condensation reaction will occur. It becomes difficult to stably obtain a polymer with an appropriate degree of polymerization, and the crystallinity during spinning becomes high, which tends to change over time, resulting in a decrease in drawability. Can't get fiber. The polymer of (A) preferably has 1 to 5 mol, more preferably 2 to 4 mol. Copolymer components other than those mentioned above may be introduced within a range that does not significantly impair high heat shrinkability. Moreover, 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 CB) may be copolymerized as long as the crimp-producing effect of the polymer (A) is not significantly reduced. In addition, the intrinsic viscosity of the polymer (B) is 0.60 to 0.7.
A degree of polymerization of 0 is preferred.

If necessary, inorganic substances such as titanium oxide, photoceramic, zirconium oxide, silicon oxide, alumina, or flame retardants, antibacterial agents, deodorants, fragrances, and hydrophilic agents such as sodium dodecylbenzenesulfonate may be mixed. You can. Furthermore, other polymers may be added to the polymers K (A) and (B) to the extent that the crimpability of the fibers is not significantly impaired.

The spinneret to be used may be a composite type spinneret having hole shapes such as O-type, Δ-type, 10-type, ■-type, T-type, etc., but it is of course not limited to these, and the composite type may also be used. Although not limited, in general, the eccentric core-sheath type and the side-by-side type are preferable because they have superior crimp development ability.

The latent crimpable conjugate fiber used in the present invention is as described in (A) above. (B
) in the range of 270 to 290°C using the above-mentioned die, and the composite ratio (A) : (B) = 40 to
It is particularly preferable to use an eccentric core-sheath type or side-by-side type conjugate fiber with a ratio of 60:60 to 40, preferably a side-by-side type conjugate fiber as described above. The melt viscosity of the two types of polymer components at the time of spinning is always (A) > (B), and the difference in viscosity at the time of melting is 100 to 1000 poise.
It is preferable to fall within this range in order to obtain composite spun fibers having excellent latent crimp ability. As the composite ratio deviates from 50:50, the two-ing phenomenon becomes more likely to occur at the nozzle discharge part, so (A):(B)=45-55:55-4
A range of 5 is most preferred.

Note that the above-mentioned melting viscosity is a value at about 285°C.

Next is bulkiness, flexibility, and elasticity. It is important for the latent crimp composite fibers constituting the paper with stretch recovery properties to have spiral crimp after heat treatment in order to impart bulkiness, flexibility, and stretchability to the paper of the present invention. It is important that the number of crimps and the shape (curvature) of the crimps are sharp. Specifically, by dry heat treatment at 170°C, the number of crimps should be 40/25 or more to develop spiral crimps. is preferred. If the number of crimps is less than 40/25, bulkiness, flexibility and stretchability are significantly reduced, resulting in a paper with high bulk specific gravity. Furthermore, the shrinkage rate during heat treatment has an important relationship with the paper's texture, bulkiness, and elasticity. A typical temperature that satisfies the general processing conditions of preset temperature 160-180℃ and final drying heat treatment temperature 130-180℃ (170℃ is selected, *M is free shrink heat treated at 170℃ If the shrinkage rate is 20% or less when the shrinkage rate is 20% or less, these items are fully satisfied.If the shrinkage rate is 20% or more, the paper becomes hard and the crimp properties, especially the crimp fastness, deteriorate9. becomes less sexual.

A crimpable conjugate fiber having such latent crimp ability and heat shrinkability has the intrinsic viscosity of the polymer (A) on the high heat shrinkage side and the polymer (B) on the low shrinkage side and... Appropriate selection of the copolymerization ratio of isophthalic acid and inphthalic acid having a metal sulfonate group in the union (A), the composite ratio of (A) and (B), and the stretching conditions and tension heat treatment conditions in the post-spinning stretching process. It is obtained by The stretching conditions are 60 to 75% of the maximum stretching ratio of the fiber after spinning to maximize the latent crimp ability, and in this state, tension heat treatment f130 to 180 ° C. It is possible to maintain high crystallinity! , a high potential crimp force is cultivated.

In addition, although it is normal to use K uncrimped fibers for wet papermaking as latent crimpable composite fibers, in order to further improve the crimpability, a push-in crimper, which is a common method, is used when dispersing in water. Mechanical crimping to the extent that no undispersion occurs, number of crimps is 3 to 20
It is also possible to use raw cotton that has been given a rating of /25. The number of crimps is 20
If it exceeds 1/25, it is not preferable to disintegrate it sufficiently with a heater or a pulper, resulting in undesirable rounding. The fineness of the latent crimpable polyester composite fiber is preferably 1 to 15 deniers, more preferably t.
, is 2 to 6 deniers. If the denier is less than 1 denier, the ability to develop spiral crimp is good, but the ability to develop crimp is weak.
It is difficult to obtain bulkiness and the spinnability is also deteriorated, making it impossible to obtain stable K yarn. Further, a region exceeding 15 denier is not preferable because it becomes stiff and lacks flexibility. The fiber length is 3 to 20 m+ for wet paper making, because K is uniformly dispersed in water and crimping is effective.
11 is preferable. Particularly preferred is 4 to 10 cm. If the length is less than 3 m, the dispersibility in water is good, but the fibers become short and fuzz and paper dust are generated, which is not preferable. If it exceeds 204, the dispersibility of the fibers is poor and the fibers become flocculent, making it difficult to obtain uniform paper.

Furthermore, if the addition rate of the latent crimpable polyester composite fiber of the present invention is less than 30% by weight, crimp will occur in each fiber, but it will be mixed with heat-fusible binder fibers and other fibers, and the crimp will be prevented by heat treatment. Even if it is obtained, stress development that overcomes the constraints of other added fibers cannot be obtained. 30 for that lick! A minimum amount is required. It's important. Preferably it is 50 fifi or more.

Additionally, a surface treatment oil may be added during the manufacturing process to improve dispersibility in water.

In order to effectively develop latent crimp properties, it is preferable to use a heat treatment method that does not apply force in the paper making direction or thickness direction.

For example, a sheet on an endless wire mesh at 140 to 180℃.
Possible methods include blowing hot air through the dryer or passing it through a through dryer, but a Yankee type or multi-tube type may also be used.
It is not device specific.

Heat-fusible binder fiber. Latently crimped polyester composite fibers and natural fibers used as necessary. Regenerated fiber.
When mixed with synthetic fibers, dryer bart and latent crimpable polyester composite fibers are heat treated! It has the role of effectively adhering each fiber in the process of developing 7% crimp.

That is, they may be thermally fused in a dryer part at 90 to 130°C, or they may be joined in a pseudo manner.

Further, it is preferable that during heat treatment at 130 to 180° C., the fibers are bonded together by heat fusion at the same time as crimping occurs. For these reasons, it is a necessary condition that the heat fusing temperature is 200° C. or less from the viewpoint of heat fusing properties and the heat treatment temperature of the latent crimpable polyester composite rutted fibers. Temperatures exceeding 200° C. are not preferred because the performance of the latent crimpable polyester composite fibers deteriorates if heat fused.

The heat-fusible binder is not preferred because flexibility cannot be obtained unless it is a fibrillar material made of a thermoplastic polymer. Preferred examples include polyolefin fibers such as polyethylene and polypropylene, and fibers made of polyester or polyamide whose melting point or softening point has been lowered by copolymerization. Naturally, a nine-core sheath-type composite fiber covered with the polymer can also be used. In this case, as the core component, an unmodified polyester-based, polypropylene-based, polyamide-based polymer, or the like is used.

The heat-fusible binder fiber used is preferably 1 to 15 deniers; if it is less than 1 denier, the dispersibility in water will be poor, and if it exceeds 15 denier, the binder effect will be reduced and the texture of the paper will deteriorate. That's why I don't like it. Regarding the number of crimps, it is preferable to use uncrimped ones in order to obtain water dispersibility, but in order to improve the bulkiness during heat treatment, it is 20 crimps/2 within the range that does not impair water dispersibility.
A crimp of 5 cm or less may be provided. If the number of crimps exceeds 20 crimps/25 m, the yarn will become tangled during water dispersion, which is not preferable.

The addition rate of the heat-fusible binder fiber needs to be 5 parts by weight or more, preferably 10 to 40 parts by weight. quintuple tS
If it is less than ○, it will not be effective in terms of paper strength, elasticity recovery, and prevention of fuzz appearing on the paper surface when the latent crimp polyester composite fibers and the natural fibers, recycled fibers, and synthetic fibers used in the present invention are mixed. Other FR fibers used in the present invention include unbleached or bleached pulp from natural fibers such as softwood and hardwood, bast fibers such as kozo, mitsumata, hemp, and ramie;
Cotton linter, bamboo. Plant fibers such as wheat straw can also be used. Also, recycled pulp, waste paper, etc. may be used. These may be unbeaten bulp or may be beaten to a Canadian freeness of about 100 to 7501. The use of these natural fibers allows the resulting paper, typified by Western paper and Japanese paper, to have excellent printability and strength. Furthermore, it has a high affinity with water, a high absorption rate, and a large amount of water absorption. It also has excellent economic efficiency.

As mentioned above, the object of the present invention is to obtain a material that has the same form and manufacturing method as paper but has the same performance as dry-processed nonwoven fabric.

In the present invention K, the mixed paper of cellulose pulp is made at high speed, and by heat treatment, a paper having the feel of a dry nonwoven fabric and the characteristics of paper is obtained. In other words, it is one of the additive fibers used to improve paper-making properties and water absorbency of products.

The next type of recycled fiber is rayon, which is made from viscose. When recycled fibers are used, it is possible to obtain a paper that is superior in bulk to conventionally produced rayon paper K, and has good flexibility and feel due to the hydrophilicity and papermaking properties of rayon.

Next, there are synthetic fibers as added fibers. Synthetic fibers such as polyester, polyolefin, polyamide, polyacrylonitrile, and polyvinyl chloride provide flexibility and bulk, and improve the feel. In addition, polyvinyl alcohol-based synthetic fibers can be used to strengthen the stiffness of paper and to improve its hydrophilicity.

Regenerated fibers and synthetic fibers preferably have a fineness of 0. 2-15
Denier ones are chosen. 0. If it is less than 2 deniers, dispersibility in water is poor and pilling is likely to occur. On the other hand, if it exceeds 15 denier, the resulting paper will become stiff and hard.
Insufficient flexibility. The number of crimps in the fiber is preferably uncrimped in consideration of dispersibility in water, but in order to provide bulkiness, flexibility, and stretchability without impairing dispersibility, the number of crimps is 20 crimps/fiber. You may give crimps of 25 cod or less. When the number of crimps is 20/25 squares or more, the dispersibility of the fibers in water is poor and the fibers become curly and ball-like, which is not preferable.The C fiber length is preferably 2 to 200, more preferably 3 to 10 squares. If it is less than 2I, the dispersibility in water is good, but flI. Because the fibers are short, fluff and paper dust are generated. On the other hand, if it exceeds 20 degrees, its dispersibility in water becomes poor, and it becomes pill-like or string-like, making it difficult to obtain a uniform texture or texture. The cross-sectional shape of such recycled fibers and synthetic fibers is not limited to circular shapes, but may include flat shapes,
U-shaped, Y-shaped, %T-shaped. Even if the shape is atypical, such as a star or triangle shape: Furthermore, it may have a hollow portion in its cross section. Further, the fiber form may be fibrillar.

In the present invention K, one or more types of fibers selected from the group consisting of the above-mentioned natural fibers, regenerated fibers, and synthetic fibers can be selected and used depending on the purpose.

As described above, the fiber raw materials used in wet papermaking K include polyester composite fibers having a latent crimp ability as defined in the present invention, heat-fusible binder fibers, and other natural fibers, recycled fibers, and other fibers added as necessary. The essential condition is that it be composed of fibers selected from the group consisting of synthetic fibers.

The method for producing bulky paper consists of using polyester composite fibers with latent crimp ability of 30 parts by weight or more, heat-fusible binder fibers of 5 parts by weight or more, and, if necessary, natural materials such as cellulose pulp fibers, etc. - A fiber mixture consisting of one or more types of fibers selected from the group consisting of recycled fibers (4) and other synthetic fibers is added with water to make a slurry of 1 to 10 parts by weight, and processed using a beater or pulper. Disintegrate to create a uniform dispersion in water. Furthermore, 0 in the chest. 5～
The slurry is diluted to form an aqueous dispersion and stirred to obtain a uniformly dispersed slurry of fibers in water, which is used as a papermaking tear fluid. The slurry is transferred to a round screen or inclined wire long screen or short screen through a vibrating screen or a dust removal device as necessary, and is mixed with circulating white water until the slurry concentration (bulp concentration in the slurry) is 0.02 to 1% by weight. Draw K on the wire. The papermaking process may be carried out in one circular net tank or in multiple tanks. Paper may be made using a combination of a plain K circular screen and a fourdrinier or a short screen. The wet paper formed on the felt is subjected to vacuum dehydration to remove excess water before being transferred to a dryer K. The type of dryer may be a Yankee type or a multi-tube type. Preferably, the wet paper on a rotating wire mesh is dried with hot air, and the paper is heated to dry and heat-treat the paper to develop crimp. In addition to this, the K1 Yankee type or multi-tube type may be used, as well as the method of drying the wet paper by applying a drying temperature of 90 to 130'C, applying winding force, and applying a heat treatment process to develop crimp. In the case of a drying process, a method of passing the material through a heat treatment process to develop crimp may be used. The heat treatment process requires a temperature of 130 to 180°C, and a hot air method in which hot air penetrates the paper layer is preferred.
It may be of a radiation type, or may be of a hot roll or hot plate adhesive type. In order to obtain the desired bulk and flexibility, it is preferable to avoid applying tension in the paper making direction, width direction, and thickness direction, and the rolling process is usually carried out under enough tension to keep the paper from moving. The paper, which is crimped through the heat treatment process, is usually passed through heated rolls at 130-200'C at regular intervals to smoothen the surface and smooth the paper. It may also be patterned or embossed to improve strength. The bulk paper is cooled and rolled up under sufficient tension.

Specific examples of these will be explained below using Examples and Comparative Examples. In Examples and Comparative Examples, Q is a value based on weight.

Example 1 A modified polyester containing ethylene terephthalate as the main component and copolymerized with 2.0 mol of 5-sodium sulfoinphthalic acid and having an intrinsic viscosity of 0.55 was used as the polymer component (A), and as the polymer component CB) Using a polyester with an intrinsic viscosity of 0.65 consisting only of ethylene terephthalate units, a composite melt spinning device κ was used to produce a side-by-side composite material with a composite ratio of so:so at 285°C from a round-section nozzle hole, and a discharge rate of 345P/min. 1 1 5 0m
/min Speed Temperature F), Capable Denier 2
700 undrawn yarns were obtained. ζ These undrawn yarns were stretched at a stretching ratio of 2.4 times and a stretching temperature of 75°C, and the tension heat treatment temperature was
Heat treatment was performed at 50"C to obtain a straight latent crimped fiber with a single fiber if 2.4 denier.
The free shrinkage rate in dry heat treatment at 70'C is 8cm,
The number of crimps was 53/25 m. The latent crimpable fibers were cut into five fibers and used as a raw material for paper making.

Actual weaving example 2 The polymer component (A) was terephthalic acid as the main dicarboxylic acid component, 5 mol% of inphthalic acid, 5-+thurium sulfoisophthalic acid, 2. Using a modified polyester having an intrinsic viscosity of 0.45 and having an intrinsic viscosity of 0.45 after 5 molar copolymerization, and using a polymer component CB) having an intrinsic viscosity of 0.60 consisting essentially of ethylene terephthalate units, composite melting was performed. A side-by-side type with a composite ratio of so:so was used at 285°C from the round-section spinneret hole of the spinning device, and 3 4 5
Discharge amount of P/mfn, 1 1 5 0 m/mi
The yarn is wound at a speed of n and is an undrawn yarn with a cable denier of 2700. After converging these undrawn yarns, the drawing ratio is 2.

Stretched 5 times at a stretching temperature of 70°C, tension heat treated at a temperature of 145°C
Heat treatment was performed at ℃ to obtain straight latent crimped fibers with a single fiber fineness of 2.5 denier.

The free shrinkage rate of this fiber due to dry heat release at 170°C is 7.
The number of crimps was 60/25 parrots.

The latent crimpable textile fibers were cut into fiber lengths of 5 cm and used as papermaking raw materials.

Examples 3 to 6 and Comparative Examples 1 to 3 Example 1. The latent crimpable polyester composite fibers obtained in Step 2, the heat-fusible binder fibers, and the cellulose bulk fibers were mixed in the formulations of Examples 3 to 6 and Comparative Examples 1 to 3 shown in Table 1 at the same time using a TAPPI standard female disintegrator. It was disintegrated at a concentration of K300 counts at 2t7t.

The slurry was further diluted to 0.2 f/t, and the slurry was sampled and made into paper using a TAPPI standard square paper machine to achieve a target basis weight of 402/m. The wet paper was dried at 70°C for 1 minute and then heat-treated on a wire mesh in an air dryer at 170°C for 4 minutes to obtain a bulky paper with crimp.

The heat-fusion binder fiber used is a composite fiber whose sheath part is a modified polyester that fuses at 130°C and whose core part is a normal polyester fiber [Kuraray Soffit N-7]
20, fiber m2 denier, fiber length 5]. Furthermore, cellulose bulp is unbleached coniferous bulp and is an unbeaten product.

In the obtained bulky paper, % of the latent crimpable polyester composite fibers were spirally crimped.

1. Space lower margin Examples 3 to 6 are related to the present invention and have a bulk specific gravity of 0.22.
Paper with the following bulkiness was obtained, and the properties of bending resistance and liquid absorption were also satisfactory. Comparative Examples 1 to 3 are outside the scope of the present invention. In both cases, the bulk specific gravity is higher than that of the examples, which is not preferable in terms of paper performance.

Examples 7 to 12 and Comparative Examples 4 to 7 Examples 7 to 12 and Comparative Examples shown in Table 2 show the latent crimpable polyester fibers, heat-fusible binder fibers, various polyester fibers, and rayon obtained in Example 2. After weighing the mixture of 4 to 7, simultaneously put 22/2 into TAP}' I standard disintegrator
The mixture was added to a concentration of t, and disintegrated for 300 counts to obtain a water-dispersed slurry.

Furthermore, the target Yotsubo view 402/
The paper was made to look like a male. The wet paper was dried at 70° C. for 1 minute and then heat-treated for 4 minutes on a wire mesh in an air dryer at 170° C. to develop crimp and obtain high-bulk paper.

Heat-adhesive binder! The fiber is Kuraray's N-720 N-720, which was used in Practical Examples 3 to 6 and Comparative Examples 1 to 3.
is the same as The nine polyester fibers used are as follows.

EPO43X5 0.4 5 Circular OEP133X5 1.3
5 # OEPC133x
5 1.3 5 z
18EJ'TC203x5 2.0
5 T type 18EPU183x5
t. s S U type 0 rayon % Rayon manufactured by Yamatobo ■ S D 1, 5 7'neel, fiber length 5, non-crimped was used.

In the obtained bulky paper K, the latent crimpable polyester composite fiber had spiral crimp.

The following examples 7 to 12 of blank sheets have the characteristics of bulkiness and flexibility of the present invention, and the amount of water and oil absorbed is 20 to 30 times that of paper. Comparative Examples 4, 5. 7 has fewer heat-fused binder fibers,
The strength of the base paper was so low that it could not be handled, and although the paper after dry heat treatment at 170°C developed some crimp, the strength of the paper was so low that it could not be used.

Example 13 As Example 13, a mixture of 40 latent crimpable polyester fibers obtained in Example 2, 20% of heat-fusible binder fibers, and 40% of U polyester fiber Kuraray Co., Ltd. gEPO43 Paper was made using the same method. The heat-fusible binder fiber is manufactured by Denden Co., Ltd. (EA-Cbo
A composite fiber having a p3 denier fiber length of 5 cm and containing polyethylene as a sheath component and polypropylene as a core component was used. As a result, the basis weight was 4. Ot/rl, thickness 0.2
2 4sa (according to JIS P 8118)
, Bulk specific gravity 0.1 80 (according to JIS P 8118), Thickness at 2.5t/IIIi' load 0.821■
, bulk specific gravity o. Obtained oso paper.

The dry and wet tensile strength is 0.04 and 0.04 respectively for a 15m width.
In h, the frequency is 25.3% and 23.5% respectively. It has a bending resistance of 32■, which is very flexible, and the amount of water and oil absorbed is 33.28f compared to 1f of paper, showing great liquid absorption. The texture is rated as ◎ for its flexibility.

The method for measuring each characteristic value in the present invention is as follows.

1》 Intrinsic viscosity: Measured at 30''C in a mixed solution of equal weights of phenol and tetrachloroethane.

(2) Fineness: JISL-1015-7-5-IA
Measured according to the following method.

(8) Number of crimp: JISL-1015-7-12-
Measured by method 1.

(4) Free shrinkage rate: JISL-1015-7-15
According to the method described above, the sample was treated in an atmosphere of 170°C for 30 minutes, and a load of 300 mm per denier was applied.

(5) Measurement of physical properties of paper Basis weight: JISP8124 Bulk Specific gravity: Stack 4 sheets of paper, apply a plastic plate at 2.5F/1, measure the thickness with a micrometer, and measure the thickness of each sheet. It was determined from the average thickness. In addition, as a method other than this, there is a method of measuring the thickness and bulk specific gravity according to the method of JIS P811B. Depending on the examples and comparative examples, this method may also be used.

Strength and breaking length. JISP8113 Stiffness Softness: Canterever method Liquid absorption Amount: Water and machine oil were used as liquid substances. Measure the weight (wo) of the paper stock cut into a size K of 10an x 10clI1. Leave it immersed in water and machine oil for 15 minutes and confirm that the air in the paper stock has been replaced.

The weight (W!) of the paper stock is measured when the paper stock is lifted into the air and no droplets fall.

: Sensitivity judgment was made as follows.

Feels like rabbit hair (soft with a slimy feel) I
(Soft feel) Cloth-like feel (Rough) Paper-like feel (Crisp) (Effects of the invention) Latent crimpable polyester composite [a and heat-fusible binder fiber and By mixing and heat-treating the paper with other natural fibers, recycled fibers, and synthetic fibers as necessary, high-quality, flexible paper can be obtained using conventional wet papermaking equipment.

In the present invention, it is possible to mix paper with pulp, and from the viewpoint of paper-making properties and economy, dry non-woven fabrics are limited to surface materials for sanitary products and disposable diapers, household and industrial wipers, medical paper, tapes, and adhesives. It can be used for applications such as base fabric, interlining, sheet-like batting, etc. On the other hand, as an industrial material, it can be used for filters, water and oil absorption materials, drain materials, insulation materials, agricultural covering materials, cushioning packaging materials, etc. by taking advantage of its bulk. .

Patent applicant: Kurare Co., Ltd.

Claims (1)

[Scope of Claims] 1) Contains 30% by weight or more of eccentric core-sheath type or side-by-side type polyester composite fibers whose crimping form is spiral crimping, and 5% by weight or more of heat-fusible binder fibers, And bulk specific gravity at 2.5g/cm^2 load is 0.
A bulky paper characterized by having a paper size of 06 or less. 2) Selected from the group consisting of natural fibers such as cellulose pulp and bast fibers, recycled fibers such as rayon, and synthetic fibers such as polyester, polyamide, polyacrylonitrile, polyolefin, polyvinyl alcohol, and polyvinyl chloride. The bulky paper according to claim 1, which contains one or more types of fibers. 3) Free shrinkage rate in dry heat treatment at 170°C is 20% or less, and the crimp form after the dry heat treatment is spiral crimp, with potential crimp ability to express crimps with a number of crimp of 40 crimps/25 mm or more. A wet paper is made from an aqueous dispersion of a fiber mixture containing 30% by weight or more of an eccentric core-sheath type or side-by-side type polyester composite fiber having a temperature of 130~ A method for producing bulky paper, characterized by carrying out heat treatment at 180°C.