JP2003049360A - Hot-melting type conjugated fiber and fiber product using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hot-melting type conjugated fiber having excellent adhesiveness to other materials and further imparting sufficient strength to the resultant nonwoven fabric and provide a fiber product using the conjugate fiber. SOLUTION: This hot-melting type conjugated fiber is obtained by attaching a fiber-finishing agent containing a polyfunctional compound which can react with a reactive functional group in a modified polyolefin to the surface of a conjugated fiber. The conjugated fiber contains a thermoplastic resin (I) containing a modified polyolefin having at least one kind of reactive functional group as a first component and contains a thermoplastic resin (II) having a melting point higher than that of the thermoplastic resin (I) as a second component, and the first component forms at least a part of the fiber surface continuously in the longitudinal direction. This fiber product represented by a nonwoven fabric is obtained by using the hot-melting type conjugated fiber.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat-adhesive conjugate fiber having a good heat-adhesive property and a fiber product such as a nonwoven fabric, a mixed cotton nonwoven fabric, a wiper and an absorber.

[0002]

2. Description of the Related Art As a heat-adhesive composite fiber, a resin having a low melting point such as polyethylene, ethylene-propylene-butene copolymer or crystalline polypropylene is arranged on the surface of the fiber, and an ethylene-propylene-butene having a high melting point is used. A composite fiber having a composite shape in which a resin such as a copolymer, crystalline polypropylene or polyester is arranged in the central portion of the fiber is generally known. Such a heat-adhesive conjugate fiber is usually formed into a web and then heated at a temperature not lower than the melting point of the low-melting point component and not higher than the melting point of the high-melting point component, so that the interfiber contact parts of the web are formed. Is formed into a fused non-woven fabric. However, since these thermo-adhesive conjugate fibers have weak adhesion to other materials such as cloth, wood and metal,
If you want to obtain a composite material that has been bonded to other materials after making it into a nonwoven fabric, or if you want to obtain a mixed cotton nonwoven fabric by mixing with other materials,
It is necessary to improve the adhesiveness by using a binder such as polyvinyl alcohol. However, when such a binder is used, the obtained non-woven fabric surface is coated with the binder to be in a film state, so that there is a problem that the performance such as absorbability of the non-woven fabric is deteriorated, and in a thick non-woven fabric, However, since the binder does not penetrate to the inside, there is a problem that delamination of the nonwoven fabric occurs.

In recent years, in order to improve these problems,
Thermoadhesive conjugate fibers having improved adhesiveness have been developed (Japanese Patent Laid-Open Nos. 53-126320 and 54-30.
929, JP 2000-212866, USP4
950541, USP 5981410). However, the thermoadhesive conjugate fiber obtained by these methods does not have sufficient fiber strength or nonwoven fabric strength even if the adhesiveness with other materials can be satisfied, and therefore, further improvement was necessary. .

[0004]

SUMMARY OF THE INVENTION The object of the present invention is to provide a heat-bonding material which does not have such problems and has excellent adhesiveness to other materials and which can give the obtained nonwoven fabric sufficient strength. To provide a composite fiber. In addition, when other materials such as cellulosic fibers are mixed to obtain a mixed cotton non-woven fabric, it is firmly adhered to the other material to prevent peeling or dropping of the other material, and imparts sufficient strength to the mixed cotton non-woven fabric. Another object of the present invention is to provide a thermo-adhesive conjugate fiber that is resistant to tearing. In addition, it is to provide a non-woven fabric having the above characteristics, a non-woven cotton blend, and a fiber product such as a wiper and an absorber using the same.

[0005]

Means for Solving the Problems The inventors of the present invention have conducted extensive studies to solve the above problems. As a result, the thermal adhesion in which the fiber treating agent containing the polyfunctional compound capable of reacting with the reactive functional group is attached to the surface of the thermoadhesive composite fiber using the modified polyolefin having the reactive functional group as the first component. It was found that the functional composite fiber exhibits excellent adhesiveness with other materials (particularly cellulosic fibers), and the nonwoven fabric obtained by using this has high nonwoven fabric strength,
The present invention has been completed based on this finding.

The present invention has the following configuration. (1) A thermoplastic resin (I) containing a modified polyolefin having at least one reactive functional group as a first component,
A composite in which a thermoplastic resin (II) having a melting point higher than that of the first component thermoplastic resin (I) is used as a second component, and the first component continuously forms at least a part of the fiber surface in the longitudinal direction. A heat-adhesive conjugate fiber, which is a fiber having a fiber treating agent containing a polyfunctional compound capable of reacting with a reactive functional group in a modified polyolefin attached to the surface of the conjugate fiber. (2) The modified polyolefin is an olefin monomer,
The thermoadhesive conjugate fiber according to item (1), which is a copolymer with an unsaturated carboxylic acid or a derivative thereof. (3) The heat-adhesive conjugate fiber according to item (1), wherein the modified polyolefin is a graft copolymer of polyethylene and an unsaturated carboxylic acid or a derivative thereof. (4) The thermoadhesive conjugate fiber according to the item (1), wherein the thermoplastic resin (II) is polypropylene. (5) The thermoadhesive conjugate fiber according to item (1), wherein the thermoplastic resin (II) is polyester. (6) The thermoadhesive conjugate fiber according to item (1), wherein the polyfunctional compound is a polyhydric alcohol. (7) The above-mentioned (1), wherein the polyfunctional compound is a polyamine.
The heat-bondable conjugate fiber according to the item. (8) The thermoadhesive conjugate fiber according to the item (1), wherein the polyfunctional compound is a polyvalent metal compound. (9) A non-woven fabric containing the thermoadhesive conjugate fiber according to any one of (1) to (8). (10) The non-woven fabric according to (9) above, which is manufactured by an air-laid method. (11) A mixed cotton non-woven fabric containing the thermoadhesive conjugate fiber according to any one of (1) to (8) and a cellulosic fiber. (12) The mixed cotton non-woven fabric as described in (11) above, which is manufactured by an air-laid method. (13) A wiper using the nonwoven fabric according to item (9) or (10). (14) A wiper using the mixed cotton nonwoven fabric according to (11) or (12). (15) An absorbent body using the nonwoven fabric according to the item (9) or (10). (16) An absorbent body using the mixed cotton nonwoven fabric according to (11) or (12).

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below.
The thermoadhesive conjugate fiber of the present invention comprises a thermoplastic resin (I) containing a modified polyolefin having at least one reactive functional group as a first component, and a thermoplastic resin (II) having a melting point higher than that of the first component. As a second component, and the first component continuously forms at least a part of the fiber surface in the longitudinal direction,
A characteristic is that a fiber treating agent containing a polyfunctional compound capable of reacting with the reactive functional group in the modified polyolefin is attached to the surface of the composite fiber.

The reactive functional group contained in the modified polyolefin contained in the thermoplastic resin (I) as the first component is appropriately selected in consideration of the reactivity with the polyfunctional compound contained in the fiber treating agent. It may be selected, but is not particularly limited. The reactive functional group that the modified polyolefin has, specifically, a hydroxyl group, an amino group, a nitrile group,
Examples thereof include nitrilo group, amide group, carbonyl group, carboxyl group and glycidyl group. The modified polyolefin having a reactive functional group is obtained by copolymerizing the vinyl monomer having a reactive functional group with an olefin monomer. The modified polyolefin may be any copolymer such as block, random or ladder. Further, it may be a copolymer obtained by grafting the vinyl monomer onto polyolefin. As the vinyl monomer having such a reactive functional group, an unsaturated carboxylic acid selected from maleic acid, acrylic acid, methacrylic acid, fumaric acid, itaconic acid or the like (including an unsaturated carboxylic acid anhydride) is selected. ), Methyl methacrylate, ethyl methacrylate, 2-hydroxyethyl methacrylate, dimethylaminoethyl methacrylate, or similar methacrylic acid esters, or similar acrylic acid esters, glycidyl acrylate, glycidyl methacrylate, butenecarboxylic acid esters, allyl Glycidyl ether, 3,4-epoxy butene, 5,6-
Examples thereof include epoxy-1-hexene and vinylcyclohexene monoxide.

The modified polyolefin used in the present invention is generally used and easily available, and has an affinity for various other materials, particularly other materials having a hydroxyl group (for example, cellulosic fibers). ), A modified polyolefin obtained by graft-copolymerizing a vinyl monomer composed of an unsaturated carboxylic acid or a derivative thereof (including an anhydride of an unsaturated carboxylic acid) with a polyolefin is preferable. It is suitable.

Such a modified polyolefin is preferable because it can be easily processed into fibers and the polymer strength is high, so that the strength of the obtained fibers is high. In addition, the modification ratio of the vinyl monomer having a reactive functional group of the modified polyolefin is 0.1 mol / kg in order to make the cross-linked structure more reactive by reacting well with the polyfunctional compound in the fiber treatment agent.
The above is preferable.

Ethylene, propylene, butene-1 and the like are preferably used as the main component monomer of the modified polyolefin. When the modified polyolefin is a graft copolymer with the vinyl monomer, the main component polymer of the modified polyolefin (which may be referred to as a trunk polymer and represents the polyolefin before modification) is polyethylene, polypropylene or polybutene. -1 and the like are preferable, and polyethylene such as high-density polyethylene, linear low-density polyethylene, and low-density polyethylene is particularly preferably used. When polyethylene is used as the main component polymer, the density is 0.90 to 0.97 g / c
Polyethylene with m ³ and a melting point of about 100 to 135 ° C. is preferable. When polypropylene is used as the main component polymer, a crystalline propylene homopolymer having a melting point of about 130 to 170 ° C. or a copolymer of propylene and another olefin is preferable. Polybutene-1 as the main component polymer
When used, a crystalline butene-1 homopolymer having a melting point of about 110 to 130 ° C. or a copolymer of butene-1 and another olefin is preferable.

Among these polymers, polyethylene is preferable because it is easy to use as a low-melting point component and is easily modified with a vinyl monomer. Above all, high-density polyethylene, which can increase nonwoven fabric strength, is more preferable because of its high polymer strength. preferable.

The thermoplastic resin (I) as the first component is not particularly limited as long as it contains the above-mentioned modified polyolefin, and a single modified polyolefin, a mixture of two or more modified polyolefins, and at least one modified polyolefin. It may be any of a mixture with at least one other thermoplastic resin. When the modified polyolefin is a graft copolymer, the copolymer tends to have lower polymer strength than the main component polymer due to the graft copolymerization. Therefore, in order to maintain the fiber strength higher, it is preferable that the thermoplastic resin (I) is a mixture of a modified polyolefin having a high modification rate and a non-modified polyolefin.

In the present invention, as the thermoplastic resin (II),
A thermoplastic resin having a melting point higher than that of the thermoplastic resin (I) is used. Examples of such a thermoplastic resin include polypropylene, polyethylene, copolymers of ethylene and α-olefins, copolymers of propylene and α-olefins other than propylene, polyethylene terephthalate (P
ET), polyester such as polybutylene terephthalate (PBT), and crystalline polymer such as polyamide can be preferably used. Furthermore, if the melting point is higher than that of the thermoplastic resin (I), a mixture of two or more of the above thermoplastic resins can be used as the thermoplastic resin (II).
In consideration of chemical resistance and compatibility with modified polyolefin, polyolefin can be preferably used as the thermoplastic resin (II). Further, in consideration of the heat-bonding processability of fibers when a nonwoven fabric or a mixed cotton nonwoven fabric is obtained, a high-melting point polypropylene capable of increasing the melting point difference with the thermoplastic resin (I) is preferable among the polyolefins. Further, it is also preferable to use polyester as the thermoplastic resin (II) because it has a high melting point and thus can have a larger difference in melting point from the thermoplastic resin (I).

The thermoplastic resin (I) as the first component and the thermoplastic resin (II) as the second component are additives for exhibiting various performances as long as they do not impair the effects of the present invention. May be added as appropriate. Examples of the additives include antioxidants, light stabilizers, ultraviolet absorbers, neutralizing agents, nucleating agents, epoxy stabilizers, lubricants, antibacterial agents, flame retardants, antistatic agents, pigments, plasticizers, etc. You can

In the thermoadhesive conjugate fiber of the present invention, the first component must form at least a part of the fiber surface. Such a composite fiber, as a base, a parallel type base,
It can be obtained by spinning with a composite spinning machine using a sheath-core type spinneret or an eccentric sheath-core type spinneret. The fiber cross-sectional shape of the heat-adhesive conjugate fiber of the present invention is not limited to a normal circular shape, but a round shape such as an ellipse, a square shape such as a square and a triangle, and an atypical fiber cross section such as a key shape and an octalobe shape. It may have a shape.

The thermoadhesive conjugate fiber of the present invention has an adhesive force with other materials even if the fiber surface formation ratio of the first component is small, but in order to have a sufficient adhesive force, It is preferable that the ratio is 50% or more of the fiber cross-section pi.
It is particularly preferable that the heat-adhesive conjugate fiber has a fiber cross-section pi of 100% or a fiber cross-sectional shape close to 100% because it has extremely strong adhesive force.

In the thermoadhesive conjugate fiber of the present invention, the composite ratio of the first component and the second component occupying the fiber cross section is 10
Spinning is possible within the range of 90% by weight / 90% by weight to 90% by weight. As the ratio of the first component decreases, the adhesive force tends to decrease, and as the ratio of the first component increases, the adhesion point tends to become stronger and the adhesive force tends to improve. The composite ratio may be determined in consideration of the desired adhesive strength, but is 30% by weight / 70% by weight to 70% by weight.
A composite ratio of / 30% by weight is preferable because it is possible to prevent deterioration of the strength and fiber processability of the composite fiber itself.

The thermoadhesive conjugate fiber of the present invention can be produced by spinning with a general-purpose melt conjugate spinning machine. The spinning temperature at that time varies depending on the type of the thermoplastic resin used, the melting point, the melt flow rate, and the thermal decomposition temperature, but is usually preferably a temperature 70 ° C. or more higher than the melting point of the thermoplastic resin. However, in order to suppress decomposition and deterioration of the modified polyolefin contained in the first component, it is preferable to spin the first component at a temperature that is higher than the melting point of the first component but is relatively low. In addition, usually, the fineness of the undrawn yarn is appropriately set and spun.

The obtained undrawn yarn may be used as it is, but usually, at a temperature lower than the melting point of the first component (usually 40 to 120 ° C.), an arbitrary draw ratio (usually 2 to 2).
It is used after being stretched 6 times). The drawn yarn obtained is
If necessary, it is crimped and used. The presence or absence of crimping is not particularly limited, and there is no problem as long as the shape is suitable for processing a nonwoven fabric. For example, when the heat-adhesive conjugate fiber is used in the air-laid method, there is no particular problem even if the heat-adhesive conjugate fiber is not crimped, but usually the number of crimps is 0 to 20 ridges / 2.54 cm. The thermoadhesive conjugate fiber having the crimp of is preferably used. On the other hand, when using the heat-bondable composite fiber in the card method,
The conjugate fiber must be crimped, and normally, a thermoadhesive conjugate fiber having a crimp number of 5 to 30 threads / 2.54 cm is preferably used. The crimp applied to the heat-adhesive conjugate fiber of the present invention may be a mechanical crimp using a crimping device such as a crimper, and is caused by the actual crimp or latent crimp of the conjugate fiber itself. It may be crimped.

The drawn yarn is usually used for a non-woven fabric after being cut to a desired length. The cutting method and the cutting length are not particularly limited as long as they are suitable for processing a nonwoven fabric.

The thermoadhesive conjugate fiber of the present invention usually has a density of 0.
It is used with a single yarn fineness of 5 to 100 decitex, but is not particularly limited. In order to increase the strength of the non-woven fabric, a heat-bondable conjugate fiber having a fine single yarn fineness, which can increase the number of fibers per certain volume and the number of intersections, is preferably used. At this time, the single yarn fineness of the heat-adhesive conjugate fiber is 0.5.
10 decitex is preferable.

The fiber treating agent used in the present invention is not particularly limited as long as it contains a polyfunctional compound capable of reacting with the reactive functional group of the modified polyolefin contained in the first component. As the polyfunctional compound, a hydroxyl group, an amino group,
2 functional groups such as nitrile group, nitrilo group, amide group, carbonyl group, carboxyl group and glycidyl group in one molecule
It is a compound or polyvalent metal compound having one or more. In consideration of safety, handleability, reactivity, and reactivity with modified polyolefin, specifically, polyhydric alcohol, polyamine, polycarboxylic acid, mixed substance of hydroxyl group and amino group, simple polyvalent metal Polyfunctional compounds such as compounds are preferred. Polyhydric alcohol is an alcohol having two or more hydroxyl groups in one molecule. The polyamine is usually 1
An aliphatic compound having two or more amino groups —NH ₂ or imino groups = NH in the molecule is meant in the present invention.
-NR ₂ in one molecule, -RNH, a functional group such as -NH ₂ 2
Also included are compounds having more than one. As the polyvalent metal compound, Mg, Ca, Sr, Zn, Al, Ti, Zr, N
Examples include simple substances such as i and Sn, oxides, hydroxides, salts, and sulfides. Since the polyfunctional compound is usually used after being diluted with water, it is preferably water-soluble, and specific examples thereof include glycerin, ethylene glycol, ethylenediamine, diethylenetriamine, maleic acid, and triethanolamine. it can.

The fiber treating agent used in the present invention may be a fiber treating agent consisting only of the above polyfunctional compound, but may also contain a leveling agent and an antistatic agent. Examples of the leveling agent include aliphatic esters such as 2-ethylhexyl stearate and isopropyl myristate, and natural oils and fats such as palm oil and beef tallow. Examples of the antistatic agent include anionic surfactants such as alkyl sulfate, fatty acid soap, alkyl sulfonate, and alkyl phosphate ester. Further, in the fiber treatment agent, additives such as an antioxidant, an antiseptic agent, an anticorrosive agent, an antibacterial agent, a wettability improver, an antifungal agent, and a weatherproofing agent are added as necessary within a range that does not impair the effects of the present invention. Can be blended.

The step of adhering the fiber treatment agent to the heat-adhesive conjugate fiber is not particularly limited, and various commonly known methods can be used. For example, during a spinning process, a stretching process, a cutting process, a subsequent process, etc., a touch roll,
It can be carried out by an attachment method such as spraying or dipping. Regarding the amount of adhesion at that time, it is generally desirable that the solid content of the fiber treating agent is in the range of 0.1 to 2.0% by weight based on the weight of the fiber. The amount of the polyfunctional compound contained in the fiber treatment agent is at least 0.005 per fiber weight.
Weight% is sufficient.

The heat-adhesive conjugate fiber of the present invention contains the modified polyolefin having the reactive functional group as the first component, and contains the polyfunctional compound capable of reacting with the reactive functional group on the fiber surface. Since the fiber treatment agent is attached,
When the heat-adhesive conjugate fiber is heat-treated, the reactive functional group in the modified polyolefin reacts with the polyfunctional compound contained in the fiber treating agent, and the modified polyolefin molecule forms a network structure. It should be noted that the melt flow rate value of the heat-adhesive conjugate fiber heat-treated without applying the fiber treatment agent is lower than the melt flow rate value of the heat-adhesion conjugate fiber heat-treated with the fiber treatment agent attached. Since the melt viscosity is high, it is considered that this network structure is caused by the crosslinking reaction. Therefore, the heat-adhesive conjugate fiber of the present invention, when producing a nonwoven fabric using the heat-adhesive conjugate fiber, at the same time as the intersection of the heat-adhesive conjugate fiber is bonded by heat treatment, at the same time, a crosslinking reaction occurs and the adhesion point Become stronger. Furthermore, since the change in the fiber cross-sectional area (fiber deformation due to high temperature treatment) due to the surface of the fiber being melted by heat and flowing out can be suppressed, the diameter of the fiber does not become thin and the strength of the fiber itself can be prevented from decreasing. Due to such an adhesive mechanism, a high-strength nonwoven fabric can be obtained by using the thermoadhesive conjugate fiber of the present invention. Furthermore, since the thermoplastic conjugate fiber of the present invention has extremely good adhesiveness to other materials, for example,
Even if it is mixed with cellulosic fibers and the like, it is possible to highly suppress the peeling and dropping of the fibers.

The nonwoven fabric of the present invention can be obtained by using the thermoadhesive conjugate fiber of the present invention, but if necessary, other thermoadhesive conjugate fiber may be further mixed in as far as the effect of the present invention is not impaired. It is also possible. The nonwoven fabric of the present invention can be obtained by forming the thermoadhesive conjugate fiber of the present invention into a web and heat-treating the web. Examples of the web-shaped processing method at that time include a card method, an air-laid method, a papermaking method, a spunlace method and the like which are usually used,
When processing by the papermaking method or spunlace method so that the fiber treatment agent adhered to the surface of the heat-adhesive composite fiber may run off, add measures such as performing heat treatment in advance so that the fiber treatment agent does not flow out. There is a need.

The blended cotton nonwoven fabric of the present invention can be obtained by using the heat-adhesive conjugate fiber and the cellulosic fiber of the present invention, but other heat-adhesive properties may be added as needed within the range not impairing the effects of the present invention. It is also possible to incorporate composite fibers. The mixed cotton non-woven fabric of the present invention can be obtained by the same processing method as the above non-woven fabric, but above all, it is easy to uniformly disperse the heat-adhesive conjugate fiber, the cellulosic fiber, etc., and the texture and texture of the obtained mixed cotton non-woven fabric. It is preferable to process by the air laid method that can improve the above. By using the airlaid method, the effects of the present invention can be sufficiently exerted. The mixing ratio of the heat-adhesive conjugate fiber and the cellulosic fiber is not particularly limited, and other fibers, fillers and super absorbent resin may be mixed within the range that does not impair the effects of the present invention. 3 to 90% by weight of heat-bondable composite fiber, 10 to 10% of cellulosic fiber
It is preferably composed in the range of 97% by weight. When the mixing ratio of the heat-adhesive conjugate fiber is within the above range, the strength of the nonwoven fabric is sufficient. Further, when the mixing ratio of the cellulosic fibers is within the above range, the characteristics of the cellulosic fibers are clearly expressed.

The air laid method is a processing method characterized by using short fibers, and is generally performed by the following procedure. First, short fibers (heat-adhesive conjugate fiber of the present invention) cut into about 5 mm are put into a fiber opening machine, mechanically opened, and then sent to a cotton feeding circulation duct together with a large amount of air. In the case of producing a mixed cotton nonwoven fabric, pulp (cellulosic fiber) crushed by a pulp crusher is simultaneously sent to a cotton feeding circulation duct, and the short fibers and the pulp are mixed in the cotton feeding circulation duct. Short fibers or mixed short fibers are discharged from a forming head equipped with a screen having round or square holes, and short fibers are laminated on a conveyor to form a fiber assembly (web). There are various forms of the forming head. For example, a form in which fibers are discharged from a screen that rotates at a high speed and suction is performed from a lower portion of the forming head by a suction device can be mentioned. Since the short fibers in the web are uniformly dispersed, the mixed cotton nonwoven fabric of the present invention has a better texture and texture than a mixed cotton nonwoven fabric with pulp produced by a method other than the air laid method. Further, since the bonding points are evenly present, it has practical strength.

The nonwoven fabric and the mixed cotton nonwoven fabric of the present invention can be easily obtained by subjecting a web made of the heat-adhesive conjugate fiber to heat treatment or the like. Examples of the heat treatment method include a hot air dryer and a suction band dryer. By performing the heat treatment, the first component of the heat-adhesive conjugate fiber is melted, and the heat-adhesion conjugate fibers are heat-bonded to each other or the intersection of the heat-adhesion conjugate fiber and the cellulosic fiber.
The heat treatment temperature at this time is most preferably a temperature above the melting point of the first component of the thermoadhesive conjugate fiber and below the melting point of the second component. The heat treatment time is preferably adjusted in consideration of the basis weight of the obtained nonwoven fabric and the mixed cotton nonwoven fabric, the heat treatment method used, and the like.

The obtained non-woven fabric and mixed cotton non-woven fabric can be heat-treated by using a general-purpose heat press machine or a conveyor type heat press machine to adjust the thickness to a desired thickness. It is also possible to perform secondary processing during and after the heat treatment to form an arbitrary shape.

The nonwoven fabric and the mixed cotton nonwoven fabric of the present invention can be laminated with other webs or sheets to form a laminated sheet. As the sheet, knitted woven fabric, non-woven fabric, urethane foam, film, paper-like material, wool molded product, metal plate, wood plate, plastic plate can be used, and these sheets are made of a material having an OH group. preferable. For example, a nonwoven fabric composed of only the heat-adhesive conjugate fiber or a mixed fiber nonwoven fabric composed of a mixture of hydrophilic fiber and the heat-adhesive conjugate fiber may be laminated on the nonwoven fabric and the mixed cotton nonwoven fabric of the present invention.
In addition, there is no problem even if other materials are laminated as long as the effects of the present invention are not impaired.

The non-woven fabric and the mixed cotton non-woven fabric of the present invention can be used for various purposes. In particular, since the non-woven fabric has high strength and good adhesion to cellulosic fibers, it can be used as a wiper, an absorber or the like. It can be used for textile applications. In particular, the mixed cotton non-woven fabric can be suitably used for fiber product applications such as wipers and absorbents because the cellulosic fibers hardly fall off.

[0034]

EXAMPLES The present invention will be described below with reference to examples, but the present invention is not limited to these examples. In addition, the measuring method of the physical-property value shown in the Example is shown below. Number of crimps: The number of crimps of the heat-adhesive conjugate fiber is defined by JIS L 1
It measured according to 015. Single yarn fineness: The single yarn fineness of the heat-bondable composite fiber is defined by JIS L
It was measured according to 1015. Unit weight: The weight of a non-woven fabric and a mixed cotton non-woven fabric cut into 50 cm squares was weighed and expressed as a weight per unit area (g / m ² ). Drop-off rate: Weight of mixed cotton nonwoven fabric cut into 10 cm squares (W1)
Was measured, and the weight (W2) after being attached to the fly comb part of the card machine and vibrating for 3 minutes under the conditions of an amplitude of 3 cm and an amplitude frequency of 1700 rpm was measured and calculated from the following formula. {(W1)-(W2)} / (W1) × 100 = fall rate (%) Specific volume: The specific volume of the nonwoven fabric and the mixed cotton nonwoven fabric was determined by the following formula. Specific volume (cm ³ / g) = thickness (mm) / basis weight (g / m ² )
× 1000 Fiber treatment agent adhesion amount (%): The fiber treatment agent adhering to 2 g of the heat-bondable composite fiber was extracted by immersing it in 25 ml of methanol, only the extracted methanol was evaporated, and the residue was weighed. It was calculated as the weight ratio to the fiber. MFR: MFR of the 1st component and the 2nd component is defined by JIS K
The measurement was carried out at a temperature of 230 ° C. according to Condition 14 of Table 1 of 7210. Fiber MFR: The MFR of the heat-bonding composite fiber is defined by JIS K
It was measured at a temperature of 230 ° C. according to the condition 14 of Table 1 of 7210 (however, in Examples 15 and 16, the heat-adhesive fiber obtained by only the first component was used). MI: The MI of the first component and the second component is defined by JIS K 7
The measurement was carried out at a temperature of 190 ° C. according to Condition 1 of Table 1 of No. 210. Non-woven fabric strength: CD is 5c from non-woven fabric and mixed cotton non-woven fabric
Three test pieces are collected so that m and MD are 15 cm. Shimadzu Corporation Autograph AG
Using S500D (trade name), gripping interval 10 cm,
Breaking strength (N / 5cm) under the condition of pulling speed 10cm / min
Was measured and the average value of the three sheets was taken as the strength of the nonwoven fabric. In addition, the machine flow direction (length direction) of non-woven fabrics and mixed cotton non-woven fabrics is M
D, the direction perpendicular to the machine flow direction (lateral direction) was defined as CD.

Examples 1 to 22 and Comparative Examples 1 to 7 Under the conditions shown in Table 1 or Table 2, the first component and the second component are used, and a sheath core type, a parallel type or an eccentric sheath core type spinneret is used. After spinning and stretching the composite fiber, an aqueous solution containing 15% by weight of the fiber treatment agent shown in Table 1 or Table 2 is attached to the surface of the composite fiber with a touch roll to obtain a heat-bondable composite fiber. It was Table 1 shows the production conditions of the heat-adhesive conjugate fiber of Examples and Table 2 and the physical properties of the conjugate fiber.

The spinning temperature shown in Table 1 or Table 2 is the temperature of the spinneret. The melting temperature before the spinneret is 220 ° C. for the first component and polypropylene for the second component (abbreviated as P
P) was set to 250 ° C, and polyester (abbreviated PET) was set to 310 ° C. The stretching temperature refers to the temperature of the stretching roll in the stretching process. Further, other abbreviations are shown below. Modified PE1: Maleic anhydride grafting using a high density polyethylene having a density of 0.960 g / cm ³ as a trunk polymer and a modification rate of 0.3 mol / kg, and MI is 3 g / 1.
0 min. Modified PE2: Maleic anhydride grafted polymer having a density of 0.960 g / cm ^{3 as} a backbone polymer and a maleic anhydride graft modification rate of 0.15 mol / kg, and MI of 10 g
/ 10 min. Modified PE3: A polymer having a maleic anhydride graft modification rate of 0.15 mol / kg using a linear low-density polyethylene having a density of 0.931 g / cm ³ as a trunk polymer, and an MI of 14 g / 10 min. Modified PE4: A terpolymer of 78% by weight of ethylene, 19.5% by weight of ethylene acrylate and 2.5% by weight of maleic anhydride, and MI of 20 g / 10 min. Modified PE5: a copolymer of ethylene and glycidyl methacrylate, having an MFR of 7 g / 10 min. Modified PP1: a polymer having polypropylene as a trunk polymer and a maleic anhydride graft modification rate of 0.15 mol / kg, and an MFR of 7 g / 10 min. PP: crystalline polypropylene (propylene homopolymer)
And, MFR is 17g / 10min. PET: Polyethylene terephthalate having a melting point of 250 ° C. HDPE: High-density polyethylene with a density of 0.960 g / cm ³ , and MI of 17 g / 10 min. LLDPE: Linear low-density polyethylene having a density of 0.935 g / cm ³ , and MI of 30 g / 10 min. co-PP: A propylene copolymer containing 4.0% by weight of ethylene and 2.7% by weight of butene-1 and having an MFR of 16 g / 10 min. Fiber treatment agent A: polyoxyethylene alkyl ether 6
An emulsion consisting of 0% by weight, 20% by weight of Na salt of alkyl phosphate, and 20% by weight of triethanolamine. Fiber treatment agent B: polyoxyethylene alkyl ether 6
An emulsion consisting of 0% by weight, 30% by weight of Na salt of alkyl phosphate, and 10% by weight of ethylenediamine. Fiber treatment agent C: polyoxyethylene alkyl ether 6
An emulsion consisting of 0% by weight, 20% by weight of fatty acid, 10% by weight of 1-5 pentanediol and 10% by weight of ethylenediamine. Fiber treatment agent D: polyoxyethylene alkyl ether 6
An emulsion consisting of 0% by weight, 15% by weight of Na salt of alkyl phosphate, 5% by weight of silicone, 10% by weight of glycerin and 10% by weight of ethylene glycol. Fiber treatment agent E: polyoxyethylene alkyl ether 6
0% by weight, alkyl phosphate Na salt 20% by weight, 1
-Emulsion consisting of 20% by weight of ethanedithiol.

[0037]

[Table 1]

[0038]

[Table 2]

As is clear from Tables 1 and 2, the heat-adhesive conjugate fiber of the present invention is compared with the conventional heat-adhesive conjugate fiber which is not treated with the fiber treatment agent which is an essential requirement of the present invention.
It was confirmed that the fiber MFR was lowered (for example,
Example 1 was 10.2 g / 10 min, and Comparative Example 1 was 26.
6 g / 10 min). This is because the modified polyolefin used in the present invention and the polyfunctional compound undergo a crosslinking reaction. As a result, it is possible to suppress a partial decrease in the fiber cross-sectional area due to melting and flowing out of the fiber surface due to heat, so that it becomes difficult to form a remarkably small (thin) part of the fiber cross-section, and it is possible to prevent a decrease in the strength of the fiber itself.

Using the thermoadhesive conjugate fibers (corresponding to each Example and Comparative Example) obtained under the conditions shown in Table 1 or Table 2, a predetermined fiber length (in accordance with the nonwoven fabric manufacturing conditions shown in Table 3) ( After cutting into 51 mm in the card method and 5 mm in the air-laid method and making a web by each method,
A through-air device set at a processing temperature of 143 ° C. was used for heat treatment to obtain a nonwoven fabric. Table 3 shows the areal weight, specific volume and nonwoven fabric strength of the obtained nonwoven fabric.

[0041]

[Table 3]

As is apparent from Table 3, the non-woven fabric of the present invention has a heat-adhesive property of the fiber treatment agent containing the polyfunctional compound capable of reacting with the reactive functional group in the modified polyolefin, which is an essential requirement of the present invention. It was confirmed that the strength of the non-woven fabric was remarkably superior to that of the non-woven fabric not attached to the surface of the composite fiber (for example, 50 N / 5 cm in Example 1 and 3 in Comparative Example 1).
0N / 5cm). This is because not only the cross-linking reaction is occurring on the fiber surface of the thermoadhesive conjugate fiber of the present invention, but also the cross-linking reaction is occurring at the contact point (melt adhesion point) between the fibers.

Using the heat-adhesive conjugate fibers (corresponding to each Example and Comparative Example) obtained under the conditions shown in Table 1 or Table 2, a predetermined fiber length that meets the mixed cotton nonwoven fabric manufacturing conditions shown in Table 4 is obtained. (51 mm for card method, 5 mm for airlaid method)
Each of the webs was cut into pieces and made into webs having the mixed cotton ratios shown in Table 4, and then heat-treated by a through-air device set at a processing temperature of 143 ° C. to obtain mixed cotton nonwoven fabrics. Table 4 shows the areal weight, the specific volume, the strength of the nonwoven fabric, and the loss rate of the cellulosic fibers of the obtained mixed cotton nonwoven fabric.

[0044]

[Table 4]

Further, as is clear from Table 4, in the mixed cotton nonwoven fabric of the present invention, as compared with the mixed cotton nonwoven fabric in which the fiber treatment agent which is an essential requirement of the present invention is not adhered to the surface of the heat-adhesive composite fiber, the nonwoven fabric strength ( For example, in Example 1, 15 N / 5 cm,
In Comparative Example 1, 4 N / 5 cm is extremely high, and the cellulosic fiber dropout rate (for example, 1.9 wt% in Example 1 and 5.6 wt% in Comparative Example 1) is extremely low, and the retention of the cellulosic fibers is high. It has been confirmed that it has excellent properties. This is because, in addition to the above reason, a crosslinking reaction occurs between the heat-adhesive conjugate fiber and the cellulosic fiber on the surface of the heat-adhesive conjugate fiber of the present invention. Further, the blended cotton nonwoven fabric obtained by the air-laid method is more uniformly dispersed and mixed with the heat-adhesive conjugate fiber and the cellulosic fiber than the blended cotton nonwoven fabric obtained by the card method. The ratio was lower (for example, 1.0% by weight in Example 20 and 3.0% by weight in Example 19), and further excellent in bulkiness (for example, 36 cm ³ / g in Example 20, Example 1).
9 is 29 cm ³ / g). From the above, it can be said that the thermoadhesive conjugate fiber of the present invention is suitable for obtaining a mixed cotton nonwoven fabric by the air laid method.

Example 23 The mixed cotton non-woven fabric of Example 1 in Table 4 was 15 cm × 15 c.
It was cut to a size of m, laminated with a polyethylene film of the same size, and subjected to embossing heat treatment at 125 ° C. to obtain a floor wipe cleaning wiper.

Comparative Example 8 15 cm × 15 c of the mixed cotton non-woven fabric of Comparative Example 1 in Table 4 was used.
It was cut to a size of m, laminated with a polyethylene film of the same size, and subjected to embossing heat treatment at 125 ° C. to obtain a floor wipe cleaning wiper.

Comparing Example 23 with the floor wipe cleaning wiper of Comparative Example 8, the floor wipe cleaning wiper of Example 23 has a higher nonwoven fabric strength than the floor wipe cleaning wiper of Comparative Example 8, and therefore, when used as a wiper. It is hard to break and the workability at the time of wiping is significantly improved. In addition, since the floor wiper wiper of Example 23 had good adhesiveness to the sheets used for lamination, workability was improved without delamination during use of the wiper.

Example 24 The mixed cotton non-woven fabric of Example 1 in Table 4 was 10 cm × 25 c.
It was cut to a size of m and the whole cut mixed cotton non-woven fabric was wrapped with a tissue paper to obtain an absorbent body for a diaper.

Comparative Example 9 The mixed cotton non-woven fabric of Comparative Example 1 in Table 4 was 10 cm × 25 c.
It was cut to a size of m and the whole cut mixed cotton non-woven fabric was wrapped with a tissue paper to obtain an absorbent body for a diaper.

Comparing Example 24 and the absorbent core for diapers of Comparative Example 9, the absorbent core for diapers of Example 24 has a higher nonwoven fabric strength than the absorbent core for paper diapers of Comparative Example 9.
The shape retention of the absorbent body was good, and the effect of preventing the absorbent body from collapsing after absorbing water etc. was high. Further, the absorbent body for a paper diaper of Example 24 was able to exhibit sufficient water absorption as an absorbent body because of its good adhesiveness to pulp.

[0052]

EFFECTS OF THE INVENTION When the heat-adhesive conjugate fiber of the present invention is heat-treated, a cross-linking reaction occurs between the heat-adhesive conjugate fibers on the fiber surface, the adhesion points are strengthened, and a highly strong nonwoven fabric is obtained. It is a composite fiber. In addition, since the adhesiveness with other materials, particularly cellulose fibers, is good, the obtained blended cotton nonwoven fabric has high strength without peeling or dropping of the cellulose fibers, and for example, absorbs hygienic materials, wipers, etc. When used as a body, it has excellent absorbency and wiping-off properties and good workability.

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 4L033 AA05 AA07 AB07 AC07 AC15                       BA12 BA45 DA02 DA05 DA06                 4L041 AA07 BA02 BA05 BA21 BA22                       BC04 BD03 BD11 CA05 CA38                       DD05                 4L047 AA08 AA14 AA29 AB02 BA09                       BB01 BB09 CB01 CC03 CC16

Claims (16)

[Claims] 1. A thermoplastic resin (I) containing a modified polyolefin having at least one reactive functional group as a first component, which has a higher melting point than the thermoplastic resin (I) of the first component (II). ) Is a second component, and the first component is a conjugate fiber in which at least a part of the fiber surface is continuously formed in the length direction, and the reactive functional group in the modified polyolefin is present on the conjugate fiber surface. A thermo-adhesive conjugate fiber to which a fiber treating agent containing a polyfunctional compound capable of reacting with is attached. 2. The heat-bondable conjugate fiber according to claim 1, wherein the modified polyolefin is a copolymer of an olefin monomer and an unsaturated carboxylic acid or a derivative thereof. 3. The thermoadhesive conjugate fiber according to claim 1, wherein the modified polyolefin is a graft copolymer of polyethylene and an unsaturated carboxylic acid or a derivative thereof. 4. The thermoadhesive conjugate fiber according to claim 1, wherein the thermoplastic resin (II) is polypropylene. 5. The thermoadhesive conjugate fiber according to claim 1, wherein the thermoplastic resin (II) is polyester. 6. The thermoadhesive conjugate fiber according to claim 1, wherein the polyfunctional compound is a polyhydric alcohol. 7. The thermoadhesive conjugate fiber according to claim 1, wherein the polyfunctional compound is a polyamine. 8. The thermoadhesive conjugate fiber according to claim 1, wherein the polyfunctional compound is a polyvalent metal compound. 9. A non-woven fabric containing the thermoadhesive conjugate fiber according to any one of claims 1 to 8. 10. The non-woven fabric according to claim 9, which is manufactured by an air laid method. 11. A mixed cotton non-woven fabric comprising the heat-adhesive conjugate fiber according to claim 1 and a cellulosic fiber. 12. The mixed cotton nonwoven fabric according to claim 11, wherein the mixed cotton nonwoven fabric is produced by an air laid method. 13. A wiper using the non-woven fabric according to claim 9 or 10. 14. A wiper using the mixed cotton nonwoven fabric according to claim 11 or 12. 15. An absorbent body using the nonwoven fabric according to claim 9 or 10. 16. An absorbent body using the mixed cotton nonwoven fabric according to claim 11 or 12.