JP3513584B2 - Stretchable nonwoven fabric, method for producing the same, and disposable diaper using the stretchable nonwoven fabric - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a stretchable nonwoven fabric. More specifically, it is a non-woven fabric having stretchability and is suitable for applications such as clothing that adheres to the skin, specifically underwear, sportswear, or sanitary materials such as diapers for children and adults and sanitary products. The present invention relates to a stretchable nonwoven fabric that can be used, a method for producing the stretchable nonwoven fabric, and a paper diaper using the stretchable nonwoven fabric.

[0002]

2. Description of the Related Art Conventionally, in applications such as underwear, sportswear, sanitary materials such as disposable diapers that adhere to the skin, stretchable nonwoven fabrics have been used to improve the wearing feeling and wearing stability. .

For example, in a paper diaper or the like, a non-woven fabric or the like in which an elastic thread is inserted is used in order to improve fit with the body such as underbody, abdomen and waist, or to prevent leakage of urine. It was

Such a stretchable non-woven fabric has been manufactured by stretching a plurality of elastic yarns into a predetermined draft and laminating it with a plurality of non-woven fabric sheets while maintaining that state.

Non-woven fabric having elasticity has been manufactured by a paper diaper manufacturing machine in one step of the paper diaper manufacturing process. More specifically, polyurethane elastic yarn or rubber yarn is used as the elastic yarn, and the elastic yarn is inserted into a plurality of non-woven fabric sheets while adjusting the amount of the elastic yarn to be positively drafted according to the rotation speed of the delivery roller. Was manufactured by

[0006]

However, in this method, a plurality of elastic yarns are stretched along the direction perpendicular to the direction in which the elastic yarns inserted for drafting by the same feeding roller are inserted. When producing a stretchable nonwoven fabric that has different stretchable power regions, where the stretchable power is weaker and the stretchable power is weaker, the stretchable power is only changed individually depending on the type and thickness of elastic yarn used. The difference in power is greatly limited by the type of elastic yarn used.

Therefore, it is difficult to impart a subtle difference in expansion / contraction power, and in particular, it is very difficult to make the expansion / contraction power have multiple levels in the direction in which a large number of elastic yarns are arranged.

[0008] In recent years, in particular, while the cost reduction by improving the productivity of material manufacturers such as elastic yarns has led to the integration of varieties and the mass production of small varieties, on the other hand, the functionality and aesthetics required for disposable diapers have reached a higher level. For example, the fit when worn requires a scientific and delicate power design for each part that is comparable to female underwear, and the appearance also
It is becoming an important factor in differentiating in a fierce competition.

In the conventional technology, it is not possible to achieve both cost reduction in the manufacturing process and enhancement of functionality and aesthetics required for disposable diaper products. In addition, it has an excellent fit when worn and a smooth curved appearance. It was not possible to obtain a disposable diaper with it.

The present invention makes it possible to achieve both cost reduction in the manufacturing process and enhancement of functionality and aesthetics required for disposable diaper products, and also has excellent wear fit and smooth curve appearance. It is an object of the present invention to provide a stretchable non-woven fabric, a method for producing the stretchable non-woven fabric, and a paper diaper using the stretchable nonwoven fabric.

[0011]

The elastic nonwoven fabric of the present invention has the following constitution in order to solve the above problems.

That is, a nonwoven fabric having a stretchable part in which a plurality of elastic yarns are inserted and fixed between nonwoven fabrics at different intervals, and different stretches are performed along a direction perpendicular to the direction in which the elastic yarns are inserted. There is a region with power , and
Inserted in areas with different stretching powers
The elastic nonwoven fabric is characterized by different elastic fiber insertion draft ratios .

The method for producing a stretchable nonwoven fabric of the present invention has the following constitution in order to solve the above problems.

That is, a plurality of elastic yarns are arranged at intervals.
A method of manufacturing a stretched or squeezed nonwoven fabric by inserting and fixing between the woven fabric, the individual Zhang when to insert the elastic yarn
A method for producing a stretchable nonwoven fabric characterized by the adjustment child forces to different levels.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION The elastic nonwoven fabric of the present invention uses elastic yarns at least in part. The elastic yarn used in the present invention includes polyurethane-based elastic fiber, polyether-ester-based elastic fiber, polyamide-based elastic fiber,
Alternatively, a thread-shaped so-called rubber thread made of natural rubber, synthetic rubber or semi-synthetic rubber, or a thread obtained by compounding or mixing with other organic synthetic resin bodies mainly composed of these, can be adopted, and the thread itself Those having rubber elasticity are preferable.

The polyurethane elastic fiber means a long-chain diol such as copolyester diol as a soft segment and diphenylmethane- as a hard segment.
Polyisocyanate elastic fiber containing difunctional isocyanate such as 4,4 diisocyanate and a difunctional hydrogen compound as a chain extender as a main constituent or polytetramethylene ether glycol as a soft segment, diphenylmethane-4,4 diisocyanate as a hard segment, chain extension It means a polyether elastic fiber containing a low-molecular weight bifunctional hydrogen compound as a main component as an agent.

The polyether / ester elastic fiber is a fiber whose main component is polytetramethylene ether glycol as a soft segment and polybutyl terephthalate as a hard segment.

In the present invention, it is preferable to use a polyurethane elastic fiber from the viewpoint of imparting desired stretchability to the final product.

The polyurethane segment of the polyurethane polymer used in the polyurethane-based elastic yarn which can be used in the present invention has a soft segment (a) such as a long-chain polyether segment, polyester segment or polyether ester segment, and an isocyanate chain. It is composed of a hard segment (b) which is a relatively short chain segment obtained by reaction with a diamine or diol which is an extender.

As the soft segment (a) of the polyurethane polymer, 1) tetramethylene glycol,
A polyether segment which is a polymer or copolymer obtained from 3-methyl-1,5-pentanediol, tetrahydrofuran, 3-methyltetrahydrofuran, etc.,
2) ethylene glycol, tetramethylene glycol,
Polyester segment obtained from diol such as 2,2-dimethyl-1,3-propanediol and dibasic acid such as adipic acid and succinic acid, 3) poly- (pentane-
1,5-carbonate) diol, poly- (hexane-)
A polyether ester segment obtained from 1,6-carbonate) diol or the like can be used, but a polyether segment obtained from tetramethylene glycol is preferable among them.

In the present invention, the polyurethane polymer is obtained by subjecting a hydroxyl-terminated soft segment precursor to a polyaddition reaction with an organic diisocyanate (capping reaction).
The prepolymer product obtained by can be obtained by chain extension with an amine chain extender or a diol chain extender.

The organic diisocyanate used for the polyurethane polymer in the present invention includes bis- (p-isocyanatophenyl) -methane (hereinafter abbreviated as MDI), tolylene diisocyanate (hereinafter abbreviated as TDI) and bis- (4-isocyanatocyclohexyl)-
Methane (hereinafter abbreviated as PICM), hexamethylene diisocyanate, 3,3,5-trimethyl-5-methylenecyclohexyl diisocyanate and the like can be used, and among them, MDI is preferable.

Various diamines such as ethylenediamine, 1,3-cyclohexanediamine and 1,4-cyclohexanediamine are preferably used as the amine chain extender for forming polyurethane urea.

The amine chain extender is not limited to only one kind of diamine, and may be composed of plural kinds of amines. Chain terminators can be included in the reaction mixture to help control the final molecular weight of the polyurethaneurea. Generally, a monofunctional compound having active hydrogen, such as diethylamine, can be used as a chain terminator.

The chain extender is not limited to the above amines and may be diols. For example, ethylene glycol, 1,3-propanediol,
4-butanediol, neopentyl glycol, 1,2
-Propylene glycol, 1,4-cyclohexanedimethanol, 1,4-cyclohexanediol, 1,4-
Bis (β-hydroxyethoxy) benzene, bis (β-
Hydroxyethyl) terephthalate, paraxylylene diol, etc. can be used. The diol chain extender is not limited to only one kind of diol and may be composed of plural kinds of diols. Moreover, you may use together with the compound containing 1 hydroxyl group which reacts with an isocyanate group. In this case, various methods such as a melt polymerization method and a solution polymerization method can be adopted as a method for obtaining such a polyurethane, and the method is not limited.
The polymerization formulation is also not particularly limited, and, for example,
A method of synthesizing polyurethane by simultaneously reacting a polyol, a diisocyanate, and a chain extender composed of a diol can be adopted, and any method may be used.

Further, it is also preferable to add another stabilizer within a range that does not impair the effects of the present invention.

As the solvent used when the polyurethane polymer is made into a solution, N, N-dimethylacetamide (hereinafter abbreviated as DMAc), dimethylformamide, dimethylsulfoxide, N-methylpyrrolidone and the like can be used. , DMAc is the most commonly used solvent.

The solution concentration of the polyurethane polymer is
A solution concentration of polyurethane polymer of usually 30-40% (based on the total weight of the solution), especially 35-38%, is preferred for the dry spinning process to obtain filament yarns of polyurethane elastic fibers.

In the present invention, the method for spinning polyurethane-based elastic fibers from a polyurethane polymer is not particularly limited, but for example, as a spinning method for polyurethane-based elastic fibers using 1) diol as a chain extender. ,
A melt spinning method, a dry spinning method, a wet spinning method, or the like can be adopted. Further, 2) As a spinning method for polyurethane-based elastic fibers using an amine as a chain extender, usually a dry spinning method can be adopted.

In the present invention, a rubber thread may be used, and the rubber thread may be of any type of natural rubber, synthetic rubber and semi-synthetic rubber.

As the rubber thread, square rubber thread, round rubber thread, flat rubber thread and the like having various sectional shapes can be used.

In the process of producing a stretchable nonwoven fabric, it is preferable to use a round rubber thread from the viewpoint of preventing the occurrence of thread breakage trouble as the friction resistance generated when the elastic thread comes into contact with another member is smaller. preferable.

The fineness of the elastic yarn can be appropriately selected according to the intended use, but is preferably in the range of 10 to 5000 denier.

When an elastic yarn of less than 10 denier is used, the elastic yarn cannot endure the running friction generated by the contact between the tension detecting sensor portion provided in the tension adjusting device and the elastic yarn, and the yarn tends to be broken. There is also 5000
If an elastic thread exceeding denier is used, the sensor section cannot withstand the running friction generated by the contact between the tension detecting sensor section and the elastic thread, and the sensor tends to be damaged.

Generally, the thickness of the rubber thread is often indicated by the count, the width of the cross section, the thickness, etc., but the thread length is 9000.
It is preferable to use denier that expresses the thickness by the weight per m from the viewpoint of easy conversion.

In the present invention, the elastic yarn may be a bare yarn or may be covered with another elastic yarn or an inelastic yarn.

In the present invention, synthetic fibers such as polyester, polyamide and polyacrylonitrile, regenerated fibers such as rayon and acetate, semi-synthetic fibers, natural fibers such as wool and cotton can be used as the non-elastic yarn. .

The form of the non-elastic yarn is long fiber filament,
It may be any of short fiber spun yarns, and can be widely selected by blending and mixing two or more kinds of fibers, crimped fibers, and other composite fibers.

The non-woven fabric used in the present invention is a wet non-woven fabric manufacturing method such as a paper making method or a dry non-woven fabric such as a resin bond type, a thermal bond type, a needle punch type, a spun bond type, a spun lace method, a melt blow method and a flash spinning method. Any of those obtained by the production method may be used.

Fibers such as rayon, polyester, polypropylene and the like are mainly used as a material for forming the non-woven fabric.

[0041] Oite in the elastic nonwoven fabric of the present invention, non-woven cloth
Elastic yarn is than also has a stretchable portion which is inserted and fixed between a plurality of elastic yarns our apart in a linear or curved manner or serpentine manner, or a combination thereof between at least two or more nonwoven it is placed you are, those that are sandwiched between these nonwoven fabric.

Further, in the present invention, the elastic yarn is inserted into the nonwoven fabric so that there are regions having different stretching powers along the direction perpendicular to the direction in which the elastic yarn is inserted. Specifically, the direction perpendicular to the direction in which the elastic yarns are inserted means that at least two or more elastic yarns 1 are inserted between the nonwoven fabric sheets 2 as indicated by an arrow X in FIG. A direction substantially perpendicular to the direction.

In the present invention, the expansion / contraction power means load power or unload power. Stretching power can usually be measured by a tensile tester.

In the present invention, the region means a portion where the above-mentioned load power or unload power obtained by the elasticity of the inserted elastic yarn is obtained. The present invention comprises such an area.

[0045] In the present invention, each of the elastic yarn insertion draft ratio (hereinafter simply inserted as draft) inserted in an area having stretchability power to differences by the child as different, the body has curved portion, for example, constriction of the waist, stomach bulge of, in such as the thickness of the change of the period from the crotch of the thigh to the knee are in so that it is possible to fit in a uniform of wearing pressure.

In the present invention, the term "insert draft" refers to the extension ratio of the inserted elastic yarn, for example, the insert draft when inserted at an extension ratio of 100% is doubled.

In other words, in the non-woven fabric after the insertion of the elastic yarn, when the elastic yarn decomposed from the non-woven fabric of the same length is untensioned and the length is measured, the higher the draft is, the shorter the length is. And the lower the insertion draft,
It means that the length becomes longer.

Further, in the present invention, the expansion and contraction powers of the regions having different expansion and contraction powers are changed in multiple steps, so that the curved parts of the body can be fitted smoothly with a uniform pressure. It is preferable from the viewpoint of being able to

The multistep change means that the expansion / contraction power smoothly changes by at least two steps. More specifically, it means that the difference gradually increases or decreases sequentially. .

Next, the method for producing the stretchable nonwoven fabric of the present invention will be described.

[0051] In this onset Akinori, and fixed to <br/> inserting a plurality of elastic yarns between nonwoven fabric.

[0052] Then, in the time to insert an elastic yarn, its
And adjusts the individual tension of the different levels.

To change the tension individually means to change the tension of the thread for changing the draft for insertion when inserting at least two elastic threads.

Then, changing the tension in multiple stages, that is, inserting at least two elastic threads,
The direction perpendicular to the direction in which the elastic thread is inserted, that is,
In the direction in which the elastic yarns are arranged, it is preferable that a difference in the insertion draft be generated between the adjacent elastic yarns, and in particular, the difference be gradually increased or decreased in order along the lined direction.

In the present invention, since the tension is changed, it is possible to use a tension adjusting device provided with a mechanism capable of positively changing the amount of yarn to be fed out.

Considering the space and operating conditions at the manufacturing site, use a product that is small, has a large degree of freedom in the installation direction, has little friction with elastic yarn, has little yarn breakage, and has good durability for continuous use. Preferably.

Specifically, MEMMINGER-IRO
Manufactured by EFS SERIES-432 type and Hepp
SESO-TE made by strike-technik
NF3000 and the like are preferably used.

Further, in the present invention, from the viewpoint of using a tension adjusting device which is independent for each elastic yarn, it is preferable to adopt a negative-feeding system (tapering system) for supplying the elastic yarn.

A specific example of the method for producing a stretchable nonwoven fabric of the present invention will be described with reference to the drawings.

The method for producing a stretchable nonwoven fabric of the present invention is to change the tension individually when inserting a plurality of elastic yarns into the nonwoven fabric.

FIG. 2 is a schematic view showing an example of the method for producing a stretchable nonwoven fabric of the present invention.

For example, as shown in FIG. 2, when five elastic thread windings are fixed to a dedicated stand 8 and the elastic thread 1 is supplied to the draft roller 7 by the negative polarity supply method (warping method), The tension of each elastic yarn 1 was independently adjusted to be different by using five tension adjusting devices 4 corresponding to each elastic yarn 1.

Then, after adjusting the draft for insertion of each elastic yarn 1, the elastic yarn 1 was supplied to a draft roller to further impart a draft. After that, the draft of each elastic yarn is 1.2 or more and 5
The following is preferable, and 2 or more and 3 or less is more preferable. It can be obtained by inserting the draft into the line to which the top sheet 5 and the back sheet 6 are fed out and fixing each elastic yarn by sandwiching it with an adhesive such as hot melt.

The nonwoven fabric of the present invention can be preferably used in a disposable diaper. In general, disposable diapers use a non-woven fabric made of rayon, polyester, polypropylene fiber, etc. as the surface material, and polyethylene film, polyethylene laminated paper, etc. as the absorbent material that absorbs urine, etc. It is a product. Since a paper diaper is generally made by inserting a rubber material into a non-woven fabric, it is preferable to use the non-woven fabric capable of imparting power to the body with more aesthetic appearance and a smooth curve according to the present invention. it can.

[0065]

EXAMPLES The present invention will be described below with reference to examples. [Example 1] Using two polypropylene nonwoven fabrics as a top sheet and a back sheet, a polyurethane elastic yarn ("Operon" T-127 X manufactured by Toray DuPont Co., Ltd.)
A, 560 denier) Five wound bodies were fixed to a dedicated stand.

When the elastic yarn is supplied to the draft roller at a running speed of 100 m / min by the negative yarn feeding method, as shown in Table 1, each elastic yarn is adjusted by five tension adjusting devices corresponding to each elastic yarn. The insertion draft was adjusted so that the tensions of the two had different values.

Further, each elastic yarn is drafted twice (100%) and inserted into the line for sending out the top sheet and the back sheet, so that the elastic yarn is sandwiched between the top sheet and the back sheet by the hot melt adhesive. The elastic nonwoven fabric was formed.

FIG. 3 is a schematic external view showing an example of the stretchable nonwoven fabric of the present invention. The obtained product is composed of a region 11 having a strong stretching power and a region 12 having a weak stretching power as shown in FIG. It had a smooth curved appearance. Comparative Example 1 Example 1 except that the tension adjusting device is not used
A non-woven fabric was manufactured under the same conditions as described above. FIG. 4 is a schematic view showing an example of a stretchable nonwoven fabric of a comparative example. As shown in FIG. 4, the obtained elastic cloth has no difference in the power of the elastic yarns, so that the tightened portion has a constricted appearance. I only got inferior ones.

[0069]

[Table 1] ★

[0070]

EFFECTS OF THE INVENTION According to the present invention, cost reduction in the manufacturing process and enhancement of functionality and aesthetics required for disposable diaper products can be achieved at the same time, and excellent fitability and smooth bending when worn. A stretchable nonwoven fabric having an elastic appearance, a method for producing the stretchable nonwoven fabric, and a paper diaper using the stretchable nonwoven fabric can be provided.

[Brief description of drawings]

FIG. 1 is a schematic view showing a direction perpendicular to a direction in which an elastic yarn is inserted in a stretchable nonwoven fabric of the present invention.

FIG. 2 is a schematic view showing an example of a method for producing a stretchable nonwoven fabric of the present invention.

FIG. 3 is a schematic external view showing an example of a stretchable nonwoven fabric of the present invention.

FIG. 4 is a schematic external view showing an example of a stretchable nonwoven fabric of a comparative example.

[Explanation of symbols]

1: Elastic thread 2: Non-woven sheet 3: Elastic bobbin 4: Tension adjusting device 5: Top sheet 6: Back sheet 7: Draft roller 8: Dedicated stand 9: Non-woven fabric 10: Elastic thread 11: Area with strong stretching power 12: Area with weak stretching power

─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-8-188950 (JP, A) JP-A-50-69363 (JP, A) SAIKAI-Hairi 2-14391 (JP, U) JP-B-45- 10787 (JP, B1) Special Table 7-500384 (JP, A) JIS Glossary Chemistry and Textiles 1969, Japan, Japan Standards Association, May 20, 1969, 1969 edition 1st edition, page 330 (58) Fields investigated (Int.Cl. ⁷ , DB name) D04H 1/00-18/00 A41B 13/00-13/04 A61F 13/00-13/84

Claims (8)

(57) [Claims] 1. A non-woven fabric having a stretchable part in which a plurality of elastic yarns are inserted and fixed between non-woven fabrics at different intervals, and different stretches are made along a direction perpendicular to the direction in which the elastic yarns are inserted. There is a region with power and it is different
The elastic thread to be inserted is
A stretchable non-woven fabric having different insertion draft ratios . 2. A region having differences stretch power, stretchable nonwoven fabric according to claim 1, stretch power is characterized different that in multiple stages. 3. A stretchable nonwoven fabric according to claim 1 or 2 elastic yarn, characterized in that a polyurethane-based elastic yarn. 4. The fineness of the elastic yarn is 10 denier or more and 500.
0 denier stretch nonwoven fabric according to any one of claims 1 to 3, wherein the less. 5. A method for producing a stretchable non-woven fabric by inserting and fixing a plurality of elastic yarns at intervals between the non-woven fabrics, wherein different tensions are applied when the elastic yarns are inserted. A method for producing a stretchable non-woven fabric, comprising: 6. The method for producing a stretchable non-woven fabric according to claim 5 , wherein elastic yarns which have been fed by the negative yarn feeding method and whose tension has been adjusted by a tension adjusting device are inserted between the non-woven fabrics. 7. The method for producing a stretchable nonwoven fabric according to claim 5, wherein the tension is changed in multiple steps. 8. A disposable diaper comprising the stretchable nonwoven fabric according to any one of claims 1 to 4 .