JP2588592B2 - Hot melt adhesive fiber - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a hot-melt adhesive fiber.

(Prior Art) In recent years, hot-melt type adhesive fibers have been frequently used in cotton padding for futons, cotton padding for quilting, and the like, for the purpose of bonding the fibers constituting each other.

In various fields, attempts have been made to use a laminate obtained by bonding a nonwoven fabric or a woven fabric to a metal. For example, there is an example in which a nonwoven fabric and an aluminum foil are laminated and used as a heat insulating material and a packaging material, and an example in which a nonwoven fabric is adhered to a metal to exhibit an anti-vibration and soundproof effect.

For example, as an adhesive fiber used in such applications,
Core-sheath type polyolefin-based adhesive fiber having polyethylene as a sheath and polypropylene as a core (JP-A-58-180614,
Polyester fibers (USP 4,129,675, JP-A-57-66117) having a sheath made of a binder fiber or a low-melting copolymer polyester made of a low-melting copolymer polyester and a high-melting polyester as a core. No.)
Etc. are known.

(Problems to be Solved by the Invention) The above-mentioned polyolefin-based adhesive fiber has a feature that the texture of the fiber structure after bonding is flexible, and the base fiber constituting the fiber structure is a polyolefin-based fiber. In the case, the adhesive fiber and the base fiber are polyester fibers or polyamide fibers, which have been widely used in the field of nonwoven fabrics in recent years. In such a case, the adhesive strength is poor, and a large amount of adhesive fibers must be used.

In addition to this problem, the fibrous structure composed of polyolefin fibers also has a problem that the coatability is poor.

In addition, when laminating a metal and a nonwoven fabric, there is a problem that the adhesive strength is poor and the film and the nonwoven fabric are easily peeled off.

The present invention solves such disadvantages of the conventional adhesive fibers, and in particular, improves the adhesiveness of a fibrous structure such as a nonwoven fabric having a polyester fiber or a polyamide fiber as a base fiber, and provides a hot fibrous structure having a flexible fibrous structure. It is intended to provide a melt-type adhesive fiber.

(Means for Solving the Problems) In the present invention, at least a part of the fiber surface is composed of (A) a polyolefin resin and (B) a conjugated diene polymer or copolymer having a molecular weight of 8,000 to 200,000. A polymer obtained by adding 1.0 to 15 parts by weight of an unsaturated carboxylic acid or a derivative thereof to 100 parts by weight of a hydrogenated product in which 50% or more of carbon-carbon double bonds have been hydrogenated is added at a ratio of (A) / (B )] Is formed from a resin composition blended so that the weight ratio is 98/2 to 70/30.

 Hereinafter, the present invention will be described in detail.

In the present invention, the resin composition used on at least a part of the fiber surface is obtained as follows.

The polyolefin resin used as the component (A) of the resin composition is isotactic or syndiotactic polypropylene, low- or medium-density polyethylene,
Ethylene-propylene copolymer, ethylene-butene-1
Such polyolefin resins can be used alone or as a mixture.

The molecular weight of the conjugated diene polymer or copolymer used in the present invention is important for developing the mechanical strength and flexibility of the resin composition, and it is necessary that the molecular weight be in the range of 8,000 to 200,000. Preferably, the range is from 10,000 to 150,000. When the molecular weight is less than this range, even when a polymer to which an unsaturated carboxylic acid is added is blended, the mechanical strength of the resin composition is liable to decrease, and bleeding to the fiber surface is likely to occur due to long-term storage. There is. on the other hand,
When the molecular weight exceeds this range, flexibility of the resin composition is not provided. By blending with a compound having a preferred molecular weight range, the melt viscosity at the time of melt-kneading is reduced, and the processability is also improved. The conjugated diene polymer or copolymer described here is obtained by a usual polymerization method such as anionic polymerization or radical polymerization, and when using the copolymer, either a block copolymer or a random copolymer is used. be able to.

The conjugated diene used in the present invention includes isoprene, 1,3-butadiene, 2,3-dimethyl-1,3-butadiene, 2-methyl-1,3-pentadiene, 1,3-hexadiene, 5-diethyl-1,3-octadiene, 3-butyl-1,3-octadiene and the like. From the viewpoint of obtaining a polymer that is industrially advantageous and has excellent physical properties, isoprene and 1,3-butadiene are particularly preferred, and isoprene polymers, isoprene / butadiene copolymers, and butadiene polymers are particularly preferred in the practice of the present invention. . In such a polymer, the microstructure of the polymer chain is not particularly limited,
Any can be suitably used.

The copolymerization ratio when using the conjugated diene copolymer is
It depends on the type of polyolefin resin to be blended. That is, it is important to select a combination of monomers and a mixing ratio that enhance the compatibility between the polyolefin resin and the polymer used as the component (B). For example, the structure of the hydrogenated product of polyisoprene is the same as that of the polymer in the case of alternating between ethylene and propylene.
Although the compatibility with the polypropylene resin such as butene-1 copolymer is good, the compatibility with the polyethylene resin is slightly reduced and bleeding is easy. On the other hand, the structure of the hydrogenated polybutadiene is the same as that of polyethylene, and although the compatibility of the component (B) polymer derived therefrom with the polyethylene resin is good, the compatibility with the polypropylene resin is reduced.

Therefore, when the polyolefin resin is polypropylene, polyisoprene is preferably used as the conjugated diene polymer, but it is also possible to use an isoprene-butadiene copolymer obtained by copolymerizing butadiene within a range that does not easily cause bleeding, In this case, the butadiene copolymerization amount is desirably 30 mol% or less. In some cases, a small amount of a vinyl monomer such as styrene may be copolymerized.

On the other hand, when the polyolefin resin used is polyethylene, isoprene-butadiene copolymer is preferably used as the conjugated diene polymer, and the butadiene mixture ratio is 5%.
The range is preferably from 80 to 80 mol%, more preferably from 10 to 65 mol%. If the butadiene copolymerization ratio is lower than this range, the compatibility with polyethylene is poor and bleeding is not preferred. When the butadiene copolymerization amount is higher than this range, the compatibility is good, but the flexibility of the blended resin composition is not sufficiently exhibited, which is not preferable.

Hydrogenation of the carbon-carbon double bond of the conjugated diene polymer or copolymer is extremely important in the present invention, and the hydrogenation ratio is in the range of 50% or more, more preferably 65%.
It can be suitably selected in the above range. The hydrogenation rate is determined by measuring the iodine value of the conjugated diene polymer or copolymer and using the following formula.

Here, A: the iodine value of the conjugated diene polymer or copolymer before hydrogenation B: the iodine value of the conjugated diene polymer or copolymer after hydrogenation When the hydrogenation rate is less than 50%, (B) The compatibility between the component polymer and the polyolefin resin is poor, and bleeding to the fiber surface is likely to occur. In addition to the problem that the mechanical strength of the resin composition is reduced, the resin composition is easily thermally decomposed when melt-kneaded with the polyolefin resin, and the obtained fiber has poor weather resistance.

Examples of the hydrogenation catalyst include a supported heterogeneous catalyst in which a metal such as nickel, platinum, palladium, and ruthenium is supported on a carrier such as carbon, silica / alumina, and diatomaceous earth, or an organic acid such as nickel, cobalt, iron, and chromium. Any of Ziegler-type homogeneous catalysts obtained by reacting a salt or an acetylacetone salt with a reducing agent such as organic aluminum in a solvent may be used.

Further, it is extremely important in the present invention to add an unsaturated carboxylic acid or a derivative thereof to a hydrogenated product of a conjugated diene polymer or a copolymer, and the amount of addition is determined by adding
It is necessary to be in the range of 1.0 to 15 parts by weight, preferably 3 to 10 parts by weight, per 0 parts by weight. If the amount of the unsaturated carboxylic acid or derivative thereof is less than this range, the adhesiveness of the resin composition will not reach a practically satisfactory level. On the other hand, if the added amount exceeds this range, the compatibility with the polyolefin resin becomes poor, bleeding to the fiber surface is liable to occur, and the adhesive strength is also reduced. Unsaturated carboxylic acids include, for example, maleic acid, itaconic acid, citraconic acid, hymic acid, bicyclo (2,2,2) octa-5
-Ene-2,3-dicarboxylic acid, 4-methylcyclohex-4-ene-1,2-dicarboxylic acid, 1,2,3,4,5,8,9,10-
Octahydronaphthalene-2,3-dicarboxylic acid, bicyclo (2,2,1) oct-7-ene-2,3,5,6-tetracarboxylic acid, 7-oxabicyclo (2,2,1) hepta 5-ene-2,3-dicarboxylic acid and the like, among these,
Particularly, maleic anhydride is preferably used. Examples of the unsaturated carboxylic acid derivative include the above-mentioned unsaturated carboxylic acid metal salt amide, imide, ester and the like. The method of adding these unsaturated carboxylic acids and their derivatives to a conjugated diene polymer or copolymer is performed by a non-catalytic thermal reaction between an unsaturated carboxylic acid and a conjugated diene polymer, or using an organic peroxide as a catalyst. It can also be performed by a thermal reaction. The thermal reaction may be performed in the presence of a solvent. Examples of the organic peroxide used here include benzoyl peroxide, lauryl peroxide, azobisisobutyronitrile, dicumyl peroxide, tert-butyl peroxybenzoate, and the like. Or 0.005 to 100 parts by weight of the copolymer
It is in the range of ~ 2.0 parts by weight.

The method for producing the polymer used as the component (B) includes: (1) adding an unsaturated carboxylic acid to a conjugated diene polymer or copolymer and then hydrogenating the same; and (2) conjugated diene polymer. Alternatively, it is possible to hydrogenate the copolymer and then add an unsaturated carboxylic acid thereto.

The blending of the polymer of the component (B) with the polyolefin resin as the component (A) can be easily carried out by melt-kneading using a general kneader such as a Banbury mixer, an extruder, a kneader or a mixing roll. The temperature for melt-kneading is not lower than the melting point of the polyolefin resin used, and is preferably in the range of 150 to 300 ° C., particularly 180 to 260 ° C.
Is suitable.

The mixing ratio of the components (A) and (B) is [(A) / (B)] = 98/2 to 70/30 by weight. When the mixing ratio of the component (B) is lower than this range, the flexibility of the obtained resin composition is insufficient, and the adhesiveness of the adhesive fiber obtained using this resin composition can be practically satisfied. It does not reach the level. If the mixing ratio of the component (B) is higher than this range, bleeding of the component (B) polymer is likely to occur on the surface of the adhesive fiber obtained using this resin composition, and therefore, the adhesive force of the fiber is low. Instead, it drops.

A preferable mixing ratio of the component (A) and the component (B) is [(A) / (B)] = 97/3 to 80/20 by weight.

Fibers obtained by using the resin composition thus obtained on at least a part of the fiber surface show good hot-melt adhesiveness.

By using this fiber as a binder fiber,
Even if the base fiber is a polyester fiber or a polyamide fiber, a good bonding effect is exhibited by the heat-fusion operation with a small amount of the binder fiber, and the fiber structure after bonding maintains a soft feeling.

Further, the nonwoven fabric and the woven fabric formed from the hot-melt type adhesive fiber of the present invention have excellent adhesiveness and paintability to metals such as aluminum and iron, and give a good laminate.

In the hot-melt type adhesive fiber of the present invention, by using this as a composite fiber having a polyolefin resin component as a sheath and a polyester or polyamide having a melting point of 130 ° C. or more as a core, the polyester or polyamide has good spinning properties. Utilizing the characteristic of having a fiber structure, it is possible to obtain an adhesive fiber having excellent spinning properties under a wide range of spinning conditions, high strength, and excellent feeling of the fiber structure after bonding.

As the polyester constituting the core component, polyethylene terephthalate, polybutylene terephthalate and polyesters based on these are preferable, and particularly, polyethylene terephthalate and a copolyester having an ethylene terephthalate unit of 80 mol% or more are preferable in view of price and strength characteristics. .

Further, as the polyamide constituting the core component, nylon-6,66,610,612,11,12 or the like can be used, and other copolymerized nylon can also be used.

In the conjugate fiber referred to in the present invention, in addition to these core-sheath fibers, a polyolefin resin composition and a polyester or polyamide having a melting point of 130 ° C. or more are compounded in a side-by-side type, and inserted into a spinning pack as a static mixing element to spin. However, those having a shape dispersed in layers or stripes are also included.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited thereto.

In addition, the measuring method of the characteristic value etc. shown in the Example is as follows.

1. Intrinsic viscosity Polyester or polyamide is dissolved in an equal weight mixed solvent of phenol and 1,1,2,2-tetrachloroethane and measured in a constant temperature water bath at 30 ° C.

2.Strong non-woven fabric The non-woven fabric is cut into a width of 25 mm and a length of 170 mm, and the distance between the chucks is 100 mm and the pulling speed is 100 mm / min with an Instron tensile tester.
Measured with

3. Rigidity Measured according to JISL1096 45 ゜ cantilever method.

4. Hand feeling The sensory test was conducted by five panelists and evaluated according to the following five levels.

1: Soft, 2: Slightly soft, 3: Normal, 4: Slightly hard, 5: Hard 5. Adhesive force between metal and nonwoven fabric The resin composition consisting of the components (A) and (B) is sheathed,
Composite weight ratio sheath component with polyethylene terephthalate as the core
A 5d composite fiber with 30 wt% and a core component of 70 wt% is made into a yarn, and a 1 mm thick non-woven fabric made of the composite fiber is produced.
Adhesion is performed by hot pressing at a temperature of 100 ° C. and a pressure of 20 to 30 kg / cm ² with a 100 μm-thick aluminum foil for 3 minutes to obtain an aluminum / nonwoven fabric laminate.

This laminate is cut to a width of 10 mm and a length of 100 mm, and then left at room temperature for one day to be used as a sample for measuring adhesive strength.

The adhesive strength was determined by measuring the strength at the time of peeling 180 ° at a speed of 30 mm / min with an Instron tensile tester in an atmosphere of a temperature of 22 ± 2 ° C. and a humidity of 65 ± 15% RH, and determined the adhesive strength.

Example 1 Polyisoprene having a number average molecular weight of 31,000 by GPC was obtained by anionic polymerization using n-butyllithium as a catalyst. This polyisoprene was dissolved in cyclohexane in an autoclave to form a 20% by weight solution. To this solution, a palladium (5% by weight) -carbon-supported catalyst was added and dispersed at 2% by weight / polymer, pressurized to 50 kg / cm ² with hydrogen, and hydrogenated at 80 ° C. while measuring the hydrogenation rate.

When the hydrogenation rate reached 90%, the hydrogenation reaction was stopped, the catalyst was separated by filtration, and dried under vacuum to obtain a 90% hydrogenated polyisoprene. An addition reaction was carried out by stirring 100 g of this polymer and 7.5 g of maleic anhydride (MAn) at 180 ° C. in a nitrogen atmosphere for 8 hours to obtain a maleic anhydride adduct of polyisoprene having a hydrogenation rate of 90%. The amount of added MAn was measured by acid value measurement, and it was confirmed that 7 parts by weight of MAn had been added.

3 g of this MAn-added hydrogenated polyisoprene and 97 g of commercially available polypropylene (Nobrene FY-6, MFR1.7 manufactured by Mitsubishi Yuka Co., Ltd.)
Was kneaded at 220 ° C. with a Brabender plastic coder to obtain a polypropylene resin composition.

After drying the polyolefin resin composition and polyethylene terephthalate chips having an intrinsic viscosity of 0.63 under reduced pressure, using a normal melt-spinning apparatus for core-sheath type composite fibers, the number of spinning holes was 26.
From the spinneret of No. 5, the spinning temperature was 270 ° C., the discharge rate was 347 g / min, the composite ratio of the polyolefin resin composition / polyethylene terephthalate was 30:70 (% by weight), and the melt spinning was performed so that the former became a sheath. Withdrawn at a rate of / min. The spinnability at this time was good.

The obtained yarn was drawn at a drawing temperature of 80 ° C to obtain an adhesive fiber having a fineness of 5d.

This adhesive fiber is cut to a length of 50 mm, and a crimped fiber of polyethylene terephthalate having a length of 50 mm is 40:60 (weight ratio).
The mixture was mixed at a rate of 40 g / m ² to give a web having a basis weight of 40 g / m ² through a card.

 Table 1 shows the characteristic values of the obtained nonwoven fabric.

Comparative Example 1 1 g of MAn-added hydrogenated polyisoprene used in Example 1,
99 g of commercially available polypropylene was kneaded in the same manner as in Example 1 to obtain a polypropylene resin composition.

The polypropylene resin composition and the polyethylene terephthalate chip used in Example 1 were spun by the same method as in Example 1 to obtain a core-sheath composite fiber, and a nonwoven fabric was obtained from the fiber.

The characteristic values of this nonwoven fabric are shown in Table 1. From these results, the nonwoven fabric using this polypropylene resin composition as the sheath component has low strength and cannot be put to practical use.

Comparative Example 2 The same procedure as in Example 1 was repeated except that polypropylene was used instead of the polyolefin resin composition.
A nonwoven fabric using a core-sheath fiber made of polyethylene terephthalate as an adhesive fiber was prepared, and its characteristic values were measured.
It was shown to.

From this result, the nonwoven fabric using the adhesive fiber having only the polypropylene as the sheath component has low strength and cannot be used practically.

Example 2 A non-woven fabric having a thickness of 1 mm was obtained with a basis weight of 40 g / m ² only from the core-sheath fiber of the polyolefin resin composition / polyethylene terephthalate prepared in Example 1, and this non-woven fabric was overlaid with a 100 μm-thick aluminum foil to form 230. ℃ temperature, pressure 20-30kg / cm ²
Of aluminum / nonwoven fabric by hot pressing for 3 minutes
After standing at room temperature for a day, the 180 ° peel adhesion was measured by the method described above.

 The results are shown in Table 1.

Comparative Example 3 An aluminum / nonwoven fabric laminate was prepared in the same manner as in Example 2 except that the polyolefin resin composition was polypropylene, and the adhesive strength at 180 ° C. peeling was evaluated. The results are shown in Table 1.

From this result, it can be seen that the adhesive strength of the nonwoven fabric to the aluminum foil is small and is insufficient for practical use.

Example 3 MAn-added hydrogenated polyisoprene obtained in Example 1 30% by weight
And 70% by weight of commercially available polypropylene were melt-kneaded in the same manner as in Example 1 to obtain a polypropylene resin composition.

From this polypropylene resin composition and the polyethylene terephthalate chip used in Example 1, a core-sheath type composite fiber was obtained by the same method as in Example 1, and a non-woven fabric was prepared using the fiber by the same method. It was shown to.

The surface of the obtained non-woven fabric has no bleeding, the characteristic value of the non-woven fabric and the adhesive force to the aluminum foil are sufficient, and it is a practically usable level.

Comparative Example 4 A nonwoven fabric was obtained in the same manner as in Example 3 except that a polypropylene resin composition having a ratio of 35% by weight of MAn-added hydrogenated polyisoprene to 65% by weight of commercially available polypropylene was used, and the physical properties were measured. The results are shown in Table 1.

The resulting nonwoven fabric is not preferred because the MAn-added hydrogenated polyisoprene bleeds from the surface and the adhesive strength to the aluminum foil is lowered.

Example 4 In the same manner as in Example 1, polyisoprene having a molecular weight of 9,000 was polymerized to obtain a 90% hydrogenated polymer. A MAn addition reaction was carried out on 100 parts by weight of the hydrogenated polyisoprene to add a MAn amount of 7
By weight, MAn-added hydrogenated polyisoprene was obtained.

10% by weight of this MAn-added hydrogenated polyisoprene and 90% by weight of a commercially available polypropylene were melt-kneaded in the same manner as in Example 1 to obtain a polypropylene resin composition.

Using this polypropylene resin composition and the same polyethylene terephthalate chip as used in Example 1, melt spinning was carried out by the same method as in Example 1, and a nonwoven fabric was further prepared, and physical properties were measured. The results are shown in Table 1,
It had sufficient performance for practical use.

Comparative Example 5 Evaluation was performed in the same manner as in Example 4 except that polyisoprene having a molecular weight of 7,000 was used.

As a result, with this molecular weight, hydrogenated polyisoprene bleeds and the surface becomes sticky, which is not preferable.

Example 5 According to the same method as in Example 1, the molecular weight was 25,000, the degree of hydrogenation was 55%, and MA
An n-added hydrogenated polyisoprene having an added amount of 7 parts by weight was obtained, and 10 parts by weight of this polymer and 90 parts by weight of commercially available polypropylene were kneaded to obtain a polypropylene resin composition.

The polypropylene resin composition and the polyethylene terephthalate chip used in Example 1 were spun into a core-sheath composite fiber by the same method as in Example 1 to obtain a nonwoven fabric.

The physical properties of the obtained nonwoven fabric were good as shown in Table 1.

Comparative Example 6 A nonwoven fabric was obtained in the same manner as in Example 5 except that a MAn-added hydrogenated polyisoprene having a hydrogenation ratio of 45% was used. The nonwoven fabric was evaluated and the results are shown in Table 1.

From this result, when a hydrogenated polyisoprene having a low hydrogenation rate is used, the compatibility with polypropylene is poor, the hydrogenated polyisoprene bleeds on the surface of the nonwoven fabric, and the surface becomes sticky,
It is easily deteriorated by heat during the kneading or spinning process, and the surface of the nonwoven fabric is slightly colored yellow.

Example 6 Evaluation was carried out in the same manner as in Example 3 except that a MAn-added hydrogenated polyisoprene having a MAn addition amount of 1.0 part by weight was used.

As a result, a nonwoven fabric having good performance as shown in Table 1 was obtained.

Comparative Example 7 Evaluation was performed in the same manner as in Example 6, except that a MAn-added hydrogenated polyisoprene having a MAn addition amount of 0.5 part by weight was used.

As a result, as shown in Table 1, the strength of the nonwoven fabric was low, and the adhesive strength with the aluminum foil was low, so that it was not practically usable.

Example 7 MA having an added amount of MAn of 15 parts by weight, a degree of hydrogenation of 70%, and a molecular weight of 25,000
An n-added hydrogenated polyisoprene was prepared, and a polypropylene resin composition was obtained by mixing 10% by weight of this polymer and 90% by weight of commercially available polypropylene.

Using this resin composition, a non-woven fabric was prepared in the same manner as in Example 1, and the non-woven fabric was evaluated.

 The results were good as shown in Table 1.

Comparative Example 8 A nonwoven fabric was prepared in the same manner as in Example 7 except that the addition amount of MAn was 18 parts by weight, and the performance was evaluated.

As a result, hydrogenated polyisoprene bleeded on the surface of the nonwoven fabric, which was not preferable.

(Effects of the Invention) According to the present invention, a hot-melt type adhesive fiber having good adhesiveness to polyester or polyamide fibers and metal and providing a fiber structure having a soft feeling can be obtained with good spinnability. Can be manufactured.

Claims (2)

(57) [Claims] (1) At least a part of the fiber surface is composed of (A) a polyolefin resin and (B) a conjugated diene polymer or a conjugated diene polymer or copolymer having a molecular weight of 8,000 to 200,000. % Or more of a hydrogenated hydrogenated product and 100 to 15 parts by weight of an unsaturated carboxylic acid or a derivative thereof is added to a polymer, and the ratio ((A) / (B)) of both is 98/100 by weight. A hot-melt adhesive fiber characterized by being formed of a resin composition blended to be 2 to 70/30. 2. A fiber comprising: (A) a polyolefin resin;
(B) 100 parts by weight of a hydrogenated product in which 50% or more of the carbon-carbon double bond in the main chain of the conjugated diene polymer or copolymer having a molecular weight of 8,000 to 200,000 is unsaturated carboxylic acid or its unsaturated carboxylic acid A resin composition obtained by blending a polymer to which 1.0 to 15 parts by weight of a derivative is added so that the ratio [(A) / (B)] of the two is 98/2 to 70/30 by weight, The hot-melt adhesive fiber according to claim 1, which is a composite fiber having a polyester or polyamide core having a melting point of 130 ° C or higher.