JPH02143847A - Laminated nonwoven fabric - Google Patents

Abstract

PURPOSE:To obtain laminated nonwoven fabric where its elongation in stress is low even if stretching properties are high and it has flexibility, hardly generates creases and is superior in uniformity of the surface, by laminating synthetic rubber nonwoven fabric and synthetic fiber nonwoven fabric having the stretching properties and low elongation in stress to each other. CONSTITUTION:Synthetic rubber nonwoven fabric and synthetic fiber nonwoven fabric having stretching properties and low elongation in stress are laminated to each other. Thermoplastic polyurethane nonwoven fabric and polyolefin nonwoven fabric having physical properties where 30% elongation in stress is 2-0.1g/cm//g/m<2> and elastic recovery after repetition of 30% expansion and contraction is at least 80% are preferable respectively as the synthetic rubber nonwoven fabric and synthetic fiber nonwoven fabric. In the case where the elastic recovery of the synthetic fiber nonwoven fabric is 80% or lower, the stretching properties of laminated nonwoven fabric is lowered. In the case where the elongation in stress of the synthetic fiber nonwoven fabric is at least 2g/cm//g/m<2>, it is not so preferable to make the elongation in stress of the laminated nonwoven fabric high.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a laminated nonwoven fabric. More specifically, it relates to a laminated nonwoven fabric that has excellent elasticity, texture, and flexibility, and has an excellent appearance such as wrinkle resistance.

[Conventional technology]

Stretchable nonwoven fabrics used as base fabrics for supporters, bandages, and poultices have traditionally been made of polyurethane nonwoven fabrics (Japanese Patent Application Laid-open No. 59-223347). A nonwoven fabric having the following properties (Japanese Patent Application Laid-Open No. 2010-201060) is known.

[Problem that the invention seeks to solve]

When rubber-based nonwoven fabrics are used for supports, etc., they have high elasticity and adhere closely to the body, but if the stretching stress is too large, they will put pressure on you and restrict you during exercise, making it impossible to fully demonstrate your body's athletic ability. isn't it. High elasticity mentioned here refers to one that is sufficiently elongated and has a large elastic recovery rate after repeated 30% elongation, and elongation stress is the stress at 30% elongation measured under the conditions described below. It is the value obtained by dividing the stress per width 1011 of the nonwoven fabric by the basis weight of the nonwoven fabric. General non-woven fabrics made of such rubber-based materials have elasticity and an elongation stress of 2 to 3.
There is also 0 g/cm//g/+/.

In addition, there is a stretchable nonwoven fabric in which a rubber nonwoven fabric is used as an intermediate mesh, and nonwoven fabric sheets are laminated on both sides of the fabric. However, the nonwoven fabric sheet used in the membrane has no elasticity and has a large stress when stretched, with a stress of 10 to 100 g/am/ when stretched by 30%.
/g/F is also available. In a nonwoven fabric made by laminating such non-stretchable nonwoven fabric sheets, the elongation stress is not reduced. In laminated nonwoven fabrics whose elongation stress is not improved,
It does not sufficiently improve stress, pressure, and freedom of movement, and wrinkles occur when used repeatedly. There is also a stretchable nonwoven fabric produced by stretching a thermoplastic polyurethane nonwoven fabric in the vertical and horizontal directions, laminating a card web of polyester fiber or the like in that state, thermally pressing the fabric, and then releasing the stretching. Wrinkles also occur in such laminated nonwoven fabrics,
It has the disadvantage of poor surface uniformity.

An object of the present invention is to provide a laminated nonwoven fabric that has a good feel, has low elongation stress even if it has high elasticity, is flexible, and is resistant to wrinkles and has an excellent surface uniformity.

[Means to solve the problem]

That is, the invention of the present application is a laminated nonwoven fabric in which a synthetic rubber nonwoven fabric and a synthetic fiber nonwoven fabric are laminated, using a synthetic fiber nonwoven fabric that is stretchable and has low elongation stress.

The synthetic fiber nonwoven fabric of the present invention needs to be a nonwoven fabric made of synthetic fibers that is stretchable and has low elongation stress. - Membrane nonwoven fabrics have no elasticity and are not suitable for the synthetic fiber nonwoven fabric of the present invention. In addition, a stretchable nonwoven fabric, for example, a nonwoven fabric made of rubber fibers is stretchable and generates large stress when stretched, and is therefore not suitable for the synthetic fiber nonwoven fabric of the present invention.

The synthetic fiber nonwoven fabric of the present invention needs to be stretchable. This stretchability is preferably 80% or more.

Furthermore, the synthetic fiber nonwoven fabric of the present invention has low elongation stress and 3
It is preferable that the stress at 0% elongation is 2 to 0.1 g/am//g/-. The elastic recovery rate of synthetic fiber nonwoven fabric is 8
If it is less than 0%, it is not preferable because the elasticity of the laminated nonwoven fabric decreases. The elongation stress of synthetic fiber nonwoven fabric is 2 g/a
If it is more than m//g/nF, the elongation stress of the laminated nonwoven fabric may increase, which is not preferable. A laminated nonwoven fabric using a synthetic fiber nonwoven fabric that is stretchable and has elongation stress is not suitable when used for a supporter or the like because it imposes too large a load on the human body.

The synthetic fiber nonwoven fabric of the present invention has specific elasticity,
If it is a nonwoven fabric made of synthetic fibers with low elongation stress, the fibers may be made of synthetic fibers such as polyolefin, polyamide, polyester, or a mixture of these with rayon, cotton, hemp, etc. It is mixed for the purpose of improving the texture and water absorption of the product, but it is preferably made of polyolefin.

In more detail, a synthetic fiber nonwoven fabric using composite fibers made of polyolefin will be explained. These composite fibers include parallel type, sheath-core type, and composite fibers with irregularly shaped fiber cross sections other than circular.As a specific example of this composite fiber, as the first component polyolefin, MFR (melt flow rate)
Crystalline polypropylene having a molecular weight of 2 to 70, preferably a prohylene homopolymer having a Q value (Mw/'gin), which is an index of the total molecular distribution, of 5.5 or less is used. The second component, the low uniqueness polyolefin, is preferably a binary or ternary copolymer containing propylene as the main component and other α-olefins such as ethylene and butene-1 as copolymer components. A copolymer having a melting point 15°C or more lower than that of the first component is used. The selection and combination of these two components, as well as the selection of spinning and drawing conditions, causes crimping and thermal contraction of the fibers when heat-treated, resulting in the desired elastic recovery rate and elongation stress when made into a nonwoven fabric. Can be done.

The method for producing the synthetic fiber nonwoven fabric of the present invention may be any known method for producing a nonwoven fabric, and is not particularly limited. can. In this case, the synthetic fibers are made into a web using a carding method, and this web is further tightly bonded by a process such as water needle bonding.
While being conveyed without tension, it is heat treated in a heat treatment machine that heats both the front and back sides with hot air. This heat treatment causes web shrinkage, and at the same time as the web shrinks, the synthetic fibers are fused and the intersections of the fibers are partially thermally bonded, resulting in a synthetic fiber nonwoven fabric with elasticity and low elongation stress. Other than this non-woven fabric, known methods such as the air flow random univer method and the wet paper making method can be used, and furthermore, a cross wrapper may be used to form a cross wrapper web. The webs may be further bonded tightly by processes such as needle punch bonding. The web may be heat-treated in a heat-treating machine having a function that does not impair the thermal shrinkage of the web while being conveyed in a tension-free state. It is also possible to further thermocompress the nonwoven fabric to an area of 5 to 50% using a thermoemboss roll.

In the present invention, the synthetic rubber nonwoven fabric is a nonwoven fabric made of fibers made from stretchable synthetic rubber.

Examples of this synthetic rubber include polyurethane-based, polyester-based, polyamide-based, fluorine-based, etc. Among polyurethane-based rubbers, thermoplastic polyurethane-based rubbers are preferred.

This thermoplastic polyurethane has urethane bonds in the molecule,
Polyurethane in a broad sense has urea bonds, and is made by melt-spinning thermoplastic polyurethane that can be melt-spun into a non-woven fabric. The raw material polyurethane may be linear polyurethane or crosslinked polyurethane, as long as it can be melt-spun. For example, molecules ff15 such as dihydroxy polyether, dihydroxy polyester, etc.
Polyols with a molecular weight of 00 to 6000 and P, P diphenylmethane diisocyanate, tolylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, xylene diisocyanate, etc. with a molecular weight of 800
The following organic diisocyanates and modrazine, diamines,
It can be chosen among polyurethanes obtained by reaction with chain extenders such as glycols.

Synthetic rubber fibers can be made into a non-woven fabric by melt-spinning synthetic rubber to form a web or non-woven fabric using a spunbond method, a melt-blowing method, etc., and further combining the process with a thermocompression bonding treatment, a dry heat treatment, etc. Further, the melt-spun fibers can be made into a carded web or a wet papermaking web and further heat-treated by a known method to obtain the fibers, and there is no particular limitation on the formation of non-woven fabrics.

The preferred denier of the fibers constituting this synthetic rubber nonwoven fabric is 1 to 500 d/f, more preferably 1 to 30 d/f.
It is. The smaller the denier, the more flexible the texture. In addition, the preferred basis weight of the synthetic rubber nonwoven fabric is lO~300 g.
／It is a male. If the nonwoven fabric weight is less than 10 g/rl, the uniformity of the nonwoven fabric will be poor, and if it is more than 300 g/rl, the texture will be poor and undesirable. The shrinkable synthetic rubber nonwoven fabric of the present invention is
It is necessary to consist of synthetic rubber fibers, preferably 70% or more, and more preferably 100% synthetic rubber fibers.
It is more preferable. In addition, this synthetic rubber nonwoven fabric has 3
The elastic recovery rate after 09A elongation is preferably 80% or more, and more preferably 90% or more.

The method for laminating the laminated nonwoven fabric of the present invention involves stacking a synthetic rubber nonwoven fabric and a synthetic fiber nonwoven fabric in two or multiple layers, and then thermocompression bonding using a heat calendar roll, heat embossing roll, etc. at a temperature higher than the heat bonding temperature. Examples of methods for doing this include, but the present invention is not limited to this, and any known method that allows lamination may be used. In the case of this hot embossing roll method, the crimping area is preferably about 5 to 50%. Alternatively, a laminated nonwoven fabric can be formed by using a dry heat or wet heat heating machine and selecting conditions such as hot air temperature and heating time that cause thermal bonding to occur at the interface of the laminated nonwoven fabric.

〔Effect of the invention〕

The laminated nonwoven fabric of the present invention is a laminated nonwoven fabric using a specific synthetic rubber nonwoven fabric and a synthetic fiber nonwoven fabric that is stretchable and has low elongation stress, so 1) it has elasticity and can simultaneously reduce elongation stress. This results in a laminated non-woven fabric with 2) excellent texture, 3) flexibility, 4) excellent appearance such as wrinkle resistance, and 5) an unprecedented and exceptional material that allows you to fully demonstrate your athletic abilities without restricting your body during exercise. It is an effective laminated nonwoven fabric.

The laminated nonwoven fabric of the present invention has a low basis weight of 15 to 150 g/♂ for applications such as bandages, surface materials for paper diapers, backing materials for paper diapers, etc., and those with a high basis weight of 150 to 300 g/-P can be used as It is useful for applications such as interlining for clothing and various stretch materials.

〔Example〕

The present invention will be explained in more detail with reference to Examples and Comparative Examples. The physical property measurement methods used for each are listed below.

Texture: The texture of the obtained laminated nonwoven fabric was examined.

Elongated window crab Various non-woven fabric length 15 cm 1 width 2.
A 5 cm sample piece was cut out and tested using a constant speed extension type self-recording tensile tester at a grip interval of 10 cm and a tensile speed of 10 cm/
(2) The strength at 30% extension after being extended by 3 cm at - is read from the recording paper (the strength at this time is defined as α (g)). Take the average value of 5 samples, and further measure the width of the sample by 1 cm.
The value was determined by the hit and divided by the basis weight of the sample. (Value converted to sample width 1c and basis weight per Ig//) Elongated window crab α (g) / 2.5 (am) / basis weight per 1 male (g/F) (g /cta// g /+/ ) Elastic recovery rate: Measure the 30% elongation stress, leave it as it is for 1 minute, and then relax at a rate of lOc/llll1.

The residual elongation (A
auw) was read from the recording paper, and after one measurement, the sample was left for 1 minute and the measurement was repeated five times. It is calculated and expressed as the average value of 5 samples using the formula below.

Wrinkle: After measuring the elastic recovery rate, leave the sample on a flat surface and
The growth of wrinkles was examined after 1 m.

Flexibility: The obtained laminated nonwoven fabric was sewn into a supporter shape for the wrist, and its restraint and pressure feeling during exercise were examined.

[Examples 1 to 6] Two types of thermoplastic polyurethanes shown below were used as synthetic rubber nonwoven fabrics. A product obtained by heating and melting a product obtained by the reaction of an aliphatic polyisocyanate and a polyether polyol, spinning it using a spunbond method, and thermocompressing the web using a thermocalender roll (G-1). A thermoplastic polyurethane obtained by the reaction of an aliphatic polyisocyanate and a polyester polyol is heated and melted, the web is spun using a melt blowing method, the web is partially heat-bonded, and the web is further thermocompressed using a calender roll (G −
2).

The following five types of synthetic fiber nonwoven fabrics were used.

F-1: MFR8.5, molecular weight distribution index Q 5°O
polypropylene as the first component, MFR8, propylene/ethylene random copolymer (Ci”97.5vt
%, C2” 2.5vt%) Softening point 130℃, Melting point 14
5°C as the second component, a parallel composite fiber with a composite ratio of 50:50, a random web using the composite fiber, heat treatment of the web at a temperature of 140°C under no tension using a hot air jet heating machine, and a web Obtained by generating a shrinkage rate of 54% and performing partial thermal bonding at the entanglement of crimps and the intersection of fibers.

F-2: The first component is the same polypropylene as F-1, and the second component is propylene/ethylene/butene-1 (Ca
"92wt%, Ct' 3.5vt%, Cm'
4.5%) MFR 12.5, softening point 110°C, melting point O''C were used, and the composite ratio and composite form were the same as F-1. Using this fiber, web formation and nonwoven fabric were made. A nonwoven fabric was obtained under the same conditions as F-1 except that the temperature was 130°C.

having partial thermal bone bonding at web entanglements and fiber intersections;
Web shrinkage was 62%.

F-3 = The first component, second component, composite ratio, composite form, etc. are the same as F-2, but the fineness is 3. OD/f, and using this composite fiber, a nonwoven fabric was obtained under the same conditions as F-1 except that the temperature was 135° C. after being subjected to a -H water needling treatment as a random wave.

F-4 = The first component uses the same polypropylene as F-1, and the second component is IIDPE (MFR 20, melting point 132 ° C.
), a composite fiber having the same composite ratio and composite form as F-1 was obtained. This fiber was made into a parallel web using a card machine. Subsequently, it was heat-treated at 145°C to obtain a nonwoven fabric in which the fiber intersections were firmly thermally bonded.

The web shrinkage rate of this nonwoven fabric was 8%.

Furthermore, the elasticity was low, with an elastic recovery rate of 60% or less after 30% elongation.

F-5: The first component is polyester, the second component is H
Using DPE (MFR20, melting point 132°C), a composite fiber having the same composite ratio and composite form as F-1 was obtained.

This fiber was made into a parallel web using a card machine.

Subsequently, it was heat-treated at 145°C to obtain a nonwoven fabric in which the fiber intersections were firmly thermally bonded. The web shrinkage rate of this nonwoven fabric was 8%. In addition, the elasticity is 60% with elastic recovery rate after 30% elongation.
% or less.

The physical properties of the synthetic rubber nonwoven fabric described above are shown in Table 1, and the physical properties of the synthetic fiber nonwoven fabric are shown in Table 2.

The M4 layer nonwoven fabric was prepared by the method described below.

3 or 2 using synthetic rubber non-woven fabric and synthetic fiber non-woven fabric
It has a layered structure. The upper part of this nonwoven fabric has a convex area of 21%,
The lower part of the heat embossing roll at a temperature of 110°C is thermocompressed using a metal roll at room temperature, and the embossed part is heat bonded to a nonwoven fabric (
Example L 2.3.4 and Comparative Example 1). Also 11
Nonwoven fabrics that were thermocompressed using a calendar roll at 0 to 125°C and thermally bonded at the interface of the nonwoven fabrics (Example 5.6, Comparative Example 2)
And so.

Table 3 shows the physical properties of the laminated nonwoven fabrics obtained.

The following can be seen from Table 3.

A laminated nonwoven fabric using a synthetic rubber nonwoven fabric and a synthetic fiber nonwoven fabric with elasticity and low elongation stress can have a three-layer structure (Examples 1, 2, 3, 4) or a two-layer structure. (Example-
5, θ) Both have a high 30% elongation elastic recovery rate of 90% or more, and a 30% elongation stress of 3 g/am//g/r
It can be seen that it is small, less than l. On the other hand, laminated nonwoven fabrics other than the present invention (Comparative Examples 1 and 2) using synthetic rubber nonwoven fabrics and synthetic fiber nonwoven fabrics with no elasticity and high elongation stress were
% elongation stress is high and elastic recovery rate is low. As a result, the texture of the laminated non-woven fabric was poor, and wrinkles appeared, probably due to structural cracks inside the non-woven fabric caused by the non-woven fabric being stretched and contracted.When used as a supporter, it felt like movement was restricted and lacked flexibility. Ta.

Claims (1)

[Scope of Claims] 1. A laminated nonwoven fabric using a synthetic fiber nonwoven fabric that is stretchable and has low elongation stress in a nonwoven fabric that is a lamination of a synthetic rubber nonwoven fabric and a synthetic fiber nonwoven fabric. 2. The synthetic rubber nonwoven fabric of the first claim is a thermoplastic polyurethane nonwoven fabric, and the synthetic fiber nonwoven fabric has a 30% elongation stress of 2 to 0.1 g/cm//g/m^2 after repeated 30% expansion and contraction. A laminated nonwoven fabric using a polyolefin nonwoven fabric having a physical property of having an elastic recovery rate of 80% or more.