JP2000008239A - Base fabric for die cutting-formed carpet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a base fabric used for die cutting-formed carpets, having an excellent base fabric strength and an excellent pile yarn-holding force and not loosening yarns on the cut surface of the base fabric, when subjected to a die-cutting treatment. SOLUTION: This base fabric for die cutting-formed carpets comprises a woven fabric in which composite tape yarns each composed of an intermediate layer comprising polypropylene and both the outer layers comprising the below resin composition are used as at least one of warps and wefts. The resin composition comprises 20-60 wt.% of a polypropylene-based resin and 40-80 wt.% of an ethylene-α-olefin copolymer produced using a metallocene catalyst having the below properties (1)-(4). (1) A melt flow rate of 0.1-10 g/10 min. (2) A density of 0.90-0.94 g/cm3. (3) The maximum peak temperature (Tm) of 80-125 deg.C by DSC. (4) A mol.wt. distribution (Mw/Mn) of 1.8-3.5.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a base fabric for a stamped and formed carpet, and more particularly to a base fabric for a stamped and formed carpet such as a car mat or a dust control mat formed by stamping.

[0002]

2. Description of the Related Art Spunbonded nonwoven fabrics have been increasingly used as a base fabric for carpets in recent years because pile yarns have good orderliness at the time of tufting and the yarns of the base fabric are hardly frayed. However, those using a spunbonded nonwoven fabric as the base fabric have drawbacks such as low base fabric strength, insufficient pile holding force, and easy thread removal.
On the other hand, those made of a woven fabric consisting of tape yarn formed by uniaxially stretching polypropylene have a strong base fabric and sufficient pile yarn holding power, but have a predetermined shape such as car mats and dust control mats. When molding by die-cutting is performed to obtain the above product, the filaments of the base fabric are frayed on the cut surface, so that it is necessary to treat the end portion, which causes a cost increase.

[0003]

SUMMARY OF THE INVENTION The present invention provides a
An object of the present invention is to provide a base fabric for a die-cut molded carpet which has excellent pile yarn holding power and does not fray the yarn in the cut surface even when the die is cut.

[0004]

The present invention provides a woven fabric using a composite tape yarn composed of an intermediate layer made of polypropylene and both outer layers made of the following resin composition as at least one of warp yarns, The resin composition is prepared by using 20 to 60% by weight of a polypropylene-based resin and an ethylene / polyethylene resin produced using a metallocene catalyst having the following properties (1) to (4).
The object of the present invention is to solve the above-mentioned problem by providing a base fabric for a die-cut molded carpet, which comprises 40 to 80% by weight of an α-olefin copolymer. (1) Melt flow rate is 0.1 to 10 g / 10 mi
n. (2) Density 0.90 to 0.94 g / cm ³ (3) Maximum peak temperature (Tm) by DSC of 80 to 1
25 ° C. (4) Molecular weight distribution (Mw / Mn) is 1.8 to 3.5

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The polypropylene used in the present invention may be a known polypropylene copolymer such as a propylene homopolymer, a propylene-ethylene block copolymer or a random copolymer, or a mixture thereof. Of these, a highly crystalline propylene homopolymer having a stretching effect is preferred, and those having an isotactic pentad ratio of 0.95 or more are particularly preferably employed.
The polypropylene has a melt flow rate (hereinafter abbreviated as MFR) of 0.1 to 20 g / 10 min., Preferably 1 to 20 g / 10 min.
It is preferable to select from the range of 10 g / 10 min.

The resin composition used for both outer layers of the composite tape yarn comprises an ethylene / α-olefin copolymer produced using a polypropylene resin and a metallocene catalyst.

The above-mentioned polypropylene resin may be the same polypropylene as the polypropylene used for the intermediate layer, but preferably has a lower melting point by at least 10 ° C. than the same polypropylene, specifically, a propylene-ethylene random copolymer, Syndiotactic polypropylene or the like is preferably used. The MFR of the polypropylene resin is selected from the range of 0.5 to 10 g / 10 min., Preferably 1.5 to 4 g / 10 min. If the MFR is less than 0.5 g / 10 min., The kneadability with the ethylene / α-olefin copolymer produced by using the metallocene catalyst is deteriorated, which causes unevenness of the extrusion.
If it exceeds g / 10 min., the strength becomes insufficient, and if the stretching ratio is increased in order to improve the strength, it causes delamination between the intermediate layer and the outer layer.

The ethylene / α-olefin copolymer produced by using the metallocene catalyst used in the present invention is:
A copolymer comprising ethylene having the following properties (1) to (4) and an α-olefin having 3 or more carbon atoms.

(1) MFR is 0.1 to 10 g / 10 mi
n., preferably 0.5 to 2 g / 10 min. M
If the FR is less than 0.1 g / 10 min., The molding processability is inferior, and if it exceeds 10 g / 10 min., Even if the stretching ratio is increased, the stretching effect is not further improved, which is not preferable.

(2) Density is 0.90 to 0.94 g / c
m ³ , preferably 0.91 to 0.93 g / cm ³ . If the density is less than 0.90 g / cm ³ , the stretching effect is not sufficient and high strength cannot be obtained. If the density exceeds 0.94 g / cm ³ , the rigidity is high and the flexibility is undesirably reduced.

(3) The maximum peak temperature (T
m) is from 80 to 125 ° C, preferably from 90 to 120 ° C. If the maximum peak temperature (Tm) by DSC is lower than 80 ° C., the melting point difference of the polypropylene resin becomes too large,
If it exceeds 125 ° C., the welding temperature becomes too high, which is not preferable.

(4) The molecular weight distribution (Mw / Mn) is 1.8
To 3.5, preferably 2.2 to 3.0. Mw / Mn
If it is less than 1.8, the moldability is poor, and if it is 3.5 or more, the stretchability is poor, which is not preferable.

The process for producing the ethylene / α-olefin copolymer is described in JP-A-58-19309 and JP-A-5-19309.
JP-A-9-95292, JP-A-60-35005, JP-A-60-35006, JP-A-60-35
No. 007, JP-A-60-35008, JP-A-60-35009, etc., by copolymerizing ethylene and an α-olefin using a metallocene catalyst.

The above-mentioned metallocene catalyst is, for example, bis (cyclopentadienyl) zirconium dichloride (Cp
₂ ZrCl ₂ ) and a catalyst composed of a metallocene compound typified by methylaluminoxane (MAO) and the like.

The metallocene compound includes a ligand having a cyclopentadienyl ring, a substituted cyclopentadienyl ring substituted with an alkyl group, an indenyl ring, and the like, and hydrogen, a halogen atom, an alkyl group, and the like having zirconium, titanium, Compounds bonded to transition metals such as hafnium, and specific examples thereof include bis (cyclopentadienyl) zirconium dichloride, bis (methylcyclopentadienyl) zirconium dichloride, and bis (ethylcyclopentadienyl) zirconium dichloride. , Bis (cyclopentadienyl) titanium dichloride, bis (methylcyclopentadienyl) titanium dichloride, bis (ethylcyclopentadienyl) titanium dichloride, bis (cyclopentadienyl) hafnium dichloride, bis (methyl) Cyclopentadienyl) hafnium dichloride, bis (ethyl cyclopentadienyl)
Hafnium dichloride and the like can be mentioned.

An aluminoxane or boron compound can be used as a co-catalyst for the metallocene compound. As the aluminoxane, usually, a chain or cyclic aluminoxane produced by bringing a trialkylaluminum into contact with water is preferable. Representative methylaluminoxane (MAO) can be obtained by reacting trimethylaluminum with water. The metallocene catalyst can be used by being supported on an inorganic oxide or the like.

The polymerization method is not particularly limited, and it is produced by a high pressure method, a solution method, a gas phase method, a slurry method or the like.

As the α-olefin to be copolymerized with ethylene, α-olefins having 3 or more carbon atoms, for example, propylene, 1-butene, 1-pentene, 1-hexene, 1-hexene
Octene, 4-methyl-1-pentene and the like.
One or two or more of these α-olefins are
It is advisable to copolymerize 50 to 50% by weight, preferably 10 to 30% by weight, with 50 to 95% by weight, preferably 70 to 90% by weight of ethylene.

The mixing ratio of the resin composition is 20 to 60% by weight of the polypropylene resin, 40 to 80% by weight of the ethylene / α-olefin copolymer, preferably 30 to 50% by weight of the polypropylene resin, The amount of the α-olefin copolymer is 50 to 70% by weight. Ethylene ・ α
If the olefin copolymer is less than 40% by weight, the effect of reducing the occurrence of yarn fraying in the cut surface by die-cutting which is the object of the present invention is small, and if it exceeds 80% by weight, the adhesive strength between the intermediate layer and both outer layers is reduced. Is undesirably reduced. The resin composition having such a configuration has a lower melting point than the polypropylene used for the intermediate layer, preferably at least 10 ° C, more preferably at least 20 ° C.

The method for producing the composite tape yarn is as follows. First, the intermediate layer is made of polypropylene and both outer layers are made of the above resin composition by a T-die method or an inflation method using a multilayer film forming die connected to two extruders. Is formed, slit to a predetermined width, stretched, and then heat-treated to form a composite tape yarn.
The stretching ratio is preferably 3 to 12 times, more preferably 5 to 12.
10 times. If the stretching ratio is smaller than 3 times, the strength of the base fabric becomes insufficient, and if it is larger than 12 times, the heat shrinkage due to the heat treatment increases, which is not preferable. The single yarn fineness of the composite tape yarn is preferably 100 to 2000 denier (hereinafter, abbreviated as d), more preferably 300 to 1000 denier.
d.

The composite tape yarn includes a split yarn obtained by subjecting a tape yarn to split processing. The method of forming the split yarn is as follows: after forming the tape in the same manner as the above-mentioned tape yarn, rotating the roll in which the file, the needle, and the blade are implanted is rotated at a high speed to damage or cut the tape, and simultaneously finely stretch the tape. It can be formed by a known method of dividing.

The composite tape yarn is a three-layer laminate composed of a polypropylene layer (H) and a resin composition layer (L). As the composition ratio (weight ratio) of (H) / (L),
Preferably 90/10 to 60/40, more preferably 8
0/20 to 70/30. If the composition ratio of (H) is less than 60% by weight, sufficient strength of the laminate cannot be obtained, and if the composition ratio of (L) is less than 10% by weight, the effect of welding at intersections is not sufficient, which is not preferable.

In the present invention, a woven fabric is formed by using the above-described composite tape yarn for at least one of the warp yarns and used as a primary base fabric for die-cut molded carpet.

In the woven fabric, the proportion of the composite tape yarn used for the warp is preferably 40% or more of the total warp, more preferably 50% or more. As the filament used in combination with the composite tape yarn, a single-layer tape yarn, a single-layer split yarn, a monofilament, a multifilament, or the like is used.

The weaving structure of the woven fabric is not particularly limited, but plain weave, mosaic weave and the like are preferable in order to have high strength and good tuftability and to prevent anisotropy of heat shrinkage.
The driving density is preferably 5 to 24 fibers / inch, and the basis weight of the woven fabric is preferably 50 to 200 g / m ² , and 80 to 150 g.
/ M ² is more preferred. If the basis weight is less than 50 g / m ² , the holding force of the base fabric against the pile yarns is reduced, causing inconveniences such as removal of the pile yarns. If the basis weight is more than 200 g / m ² , the fiber amount of the base fabric is large and the pile intervals are uneven. .

In the present invention, the intersections of the warp yarns of the base fabric are welded with the resin composition provided on the outer layer of the composite tape yarn and are subjected to the filling process, and the melting point of the resin composition forms the intermediate layer. At least 10 ° C higher than polypropylene
Because of the low melting point, the intermediate layer can be thermally welded without causing thermal degradation during welding. The filling process may be performed before tufting of the pile yarn, but if the intersection of the warp yarn is not heat-welded at the time of tufting, the warp yarn has a high degree of freedom, so it has excellent tufting properties, such as backing processing. A raw material for carpet having excellent shape stability after post-processing can be obtained. In that case, the intersection of the warp yarns is welded by heating during the backing process, and the filling process is performed.

After the pile yarn is tufted to the base fabric, a backing process is performed. The backing layer is mainly made of the same polyvinyl chloride, polyolefin resin or the like as in the prior art. The backing temperature is preferably lower than the melting point of polypropylene and is preferably in a temperature range not lower than the softening point of the low-melting point resin composition, usually 100 to 140 ° C.
20-130 degreeC is more preferable.

In the present invention, the welding at the intersections of the warp yarns is preferably performed by heating the backing process after planting the pile yarns in the base cloth. When the intersections of the warp yarns are heat-welded, a carpet having a good finish without fraying can be obtained in a cross-section cut and formed by a die.

The base fabric for a die-cut molded carpet of the present invention comprises:
It is used not only for car mats and dust control mats, but also for square tile carpets used for buildings and houses, and mats shaped to fit floors of vehicles, ships, aircrafts, and the like.

The polyolefin of the present invention contains an antioxidant, an ultraviolet absorber, a light stabilizer, a lubricant, an antistatic agent, a pigment, an inorganic filler, without departing from the spirit of the present invention.
Additives such as a flame retardant, a cross-linking agent, a foaming agent, and a nucleating agent can be compounded and used.

[0031]

EXAMPLES Polypropylene (MFR = 1.2 g / 10 m)
in., density = 0.90 g / cm ³ , Tm = 161 ° C.) as an intermediate layer, and propylene-ethylene copolymer (MFR = 18.0 g / 10 min., ethylene content =
6.0% by weight, Tm = 139 ° C.) and an ethylene / α-olefin copolymer (MF) using a metallocene catalyst
R = 2.5 g / 10 min., Density = 0.926 g / c
m ³ , Tm = 121 ° C., Mw / Mn = 2.5) 70% by weight
After slitting the three-layer film having both outer layers using the resin composition described above, it was stretched about 6 times to obtain a composite tape yarn having a single yarn fineness of 800d. On the other hand, a tape yarn having a single yarn fineness of 400 d was similarly obtained using the above polypropylene.

The above 400d tape yarn is woven with a driving density of 22 yarns / inch using a warp as a warp and an 800d composite tape yarn is woven with a driving density of 14 yarns / inch as a weft, and then subjected to a perforation process to give a basis weight of 100 g. / M < ² > base fabric was produced. After a nylon loop pile yarn was planted on this base fabric by a tufting method, the back surface was subjected to backing processing using an ethylene-vinyl acetate resin at a backing temperature of 130 ° C. Furthermore, a car mat was obtained by die-cutting the raw carpet.

Since the intersection of the warp yarns was welded to the car mat of the example, the car mat was suitable as a car mat having excellent appearance without fraying of the yarn in the cross section of the base fabric cut by the die cutting.

[0034]

As described above, the base fabric for the die-cut molded carpet of the present invention comprises polypropylene as an intermediate layer,
A woven fabric using, as at least one of the weft yarns, a composite tape yarn having a resin composition composed of a polypropylene resin and an ethylene / α-olefin copolymer produced using a metallocene catalyst as both outer layers, Since the intersections of the yarns are welded, the pile yarns are excellent in orderlyness, and the die-cutting provides a base fabric for a die-cut molded carpet with no yarn fraying in the cross-section of the base fabric.

Claims (1)

[Claims] 1. A woven fabric using a composite tape yarn composed of an intermediate layer made of polypropylene and both outer layers made of the following resin composition for at least one of the warp yarns,
The resin composition is 20 to 60% by weight of a polypropylene resin.
And an ethylene / α-olefin copolymer 4 produced using a metallocene catalyst having the following properties (1) to (4):
A base fabric for die-cut molded carpet, comprising 0 to 80% by weight. (1) Melt flow rate is 0.1 to 10 g / 10 mi
n. (2) Density 0.90 to 0.94 g / cm ³ (3) Maximum peak temperature (Tm) by DSC of 80 to 1
25 ° C. (4) Molecular weight distribution (Mw / Mn) is 1.8 to 3.5