JP2003268648A - Base fabric for artificial lawn and the artificial lawn using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a base fabric for artificial lawn, having suitable flexibility, being scarcely cracked longitudinally, and having enough strength, by using a reclaimed polyethylene terephthalate resin. <P>SOLUTION: This base fabric for the artificial lawn is formed by mixing a specified amount of a polybutylene terephthalate resin into the polyethylene terephthalate resin. The base fabric preferably contains a specific amount of a linear low-density polyethylene. The formed base fabric is excellent in moldability and impact resistance, has the suitable flexibility, is scarcely cracked longitudinally, and has the enough strength. The artificial lawn is obtained by using the base fabric. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the reuse of recovered polyethylene terephthalate resin, and in particular, a composition in which a specific amount of polybutylene terephthalate is blended with the recovered polyethylene terephthalate resin as a raw material component. The present invention relates to an artificial turf base fabric formed by the above and an artificial turf using the same.

[0002]

2. Description of the Related Art Conventionally, polyethylene terephthalate resin has been widely used as a material for beverage containers and sheets. In particular, containers made of polyethylene terephthalate resin called PET bottles are superior in terms of lightness, workability, strength, etc., compared to glass, paper and metal containers, and therefore rapidly. The amount of use has been increasing, and it has become a major environmental issue regarding its disposal.
From the viewpoint of effective use of resources, establishment of recycling technology is an urgent task.

From the standpoints of resource protection and environmental protection, various proposals have been made regarding the technology for reusing the recovered polyethylene terephthalate resin (hereinafter referred to as recycled PET resin), but it is said that it has been used. As for the amount of PET bottles and other containers that have become empty, even if the collection is done efficiently, there are still few proposals for powerful technologies that can fully digest the collected PET resin. . That is, when the recovered PET resin is crushed by a crusher and then melt-extruded by an extruder to be processed into pellets as a resin raw material, the intrinsic viscosity is lowered by hydrolysis,
That is, strength physical properties are deteriorated due to the decrease in molecular weight. Therefore, when the recovered PET resin is reused, the application tends to be limited, and the expanded use of the recovered resin has not progressed sufficiently.

[0004]

Regarding the reuse of the above-mentioned recycled PET resin, when the recycled PET resin is used to form a film, the formability is poor, and the obtained film is hard and poor in flexibility. The base cloth for artificial turf using split yarn that has been slit, stretched to make a flat yarn, and further splitted has a problem that it is easily cracked longitudinally and its strength is insufficient. It is an object of the present invention to provide a base cloth for artificial turf, which is made of recycled PET resin, has appropriate flexibility, is resistant to longitudinal cracking, and has sufficient strength.

[0005]

Means for Solving the Problems The inventors of the present invention have made extensive studies to solve the above problems, and as a result, by using a resin composition prepared by blending recycled PET resin with polybutylene terephthalate in a specific ratio, It was found that a split yarn artificial turf base cloth having improved moldability, moderate flexibility, vertical cracking resistance, and sufficient strength can be obtained, and the present invention was completed. That is, the gist of the first invention of the present invention is a base cloth for artificial turf comprising a composition of 80 to 95% by weight of a polyethylene terephthalate resin and 5 to 20% by weight of a polybutylene terephthalate resin, and the second aspect of the present invention. The gist of the invention resides in a base cloth for artificial turf made of a composition of 50 to 90% by weight of polyethylene terephthalate resin, 5 to 20% by weight of polybutylene terephthalate resin, and 5 to 30% by weight of linear low density polyethylene.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below. In the present invention, the artificial turf is a woven fabric made of a fibrous body of a polyethylene terephthalate resin composition called a primary base fabric, a knitted fabric, a flat fabric made of a thermoplastic resin such as polyethylene terephthalate on a base fabric for artificial turf made of a non-woven fabric or the like. Tufting multiple pile yarns of yarn or monofilament, cutting the looped top of the pile to make grass leaves, and then lining the back side of the base fabric with a latex material to add pile yarns to the primary base fabric. Manufactured by fixing. The polyethylene terephthalate resin (hereinafter referred to as PET) used in the present invention is a polymer obtained by polycondensing terephthalic acid or a terephthalic acid derivative as an acid component and ethylene glycol as a glycol component, A copolymer in which a part of the terephthalic acid component and / or the ethylene glycol component is replaced with a copolymerization component is also included. As the PET,
Virgin PET and recycled PET are preferably used.
As recycled PET, a container for beverage made of polyethylene terephthalate (commonly called PET bottle) is usually used by crushing and re-pelletizing. In the re-pelleting step, the intrinsic viscosity (η value) decreased due to water absorption or heat history. )
Can be used by adjusting by solid-state polymerization. The recycled PET can also be used by appropriately mixing it with the virgin PET.

The intrinsic viscosity [η] of the above PET is
It is in the range of 0.4 to 1.5, preferably 0.6.
The range is from to 1.1. If [η] is less than 0.4, the tensile strength of the flat yarn is weak and longitudinal cracks are likely to occur, and if [η] exceeds 1.5, the fluidity is poor during melt extrusion and yarn breakage is unfavorable.

The polybutylene terephthalate resin (hereinafter abbreviated as PBT) of the present invention is obtained by polycondensing terephthalic acid or a terephthalic acid derivative as an acid component and tetramethylene glycol as a glycol component. Copolymers that are a combination and in which a part of the terephthalic acid component and / or the tetramethylene glycol component is replaced with a copolymerization component are also included.

The intrinsic viscosity [η] of the PBT is
It is in the range of 0.6 to 1.8, preferably 0.8.
The range is from to 1.5. When [η] is less than 0.6, PBT
Has high crystallinity, so vertical cracks easily occur.
If [η] exceeds 1.8, the workability is deteriorated, which is not preferable.

The blending ratio with the above PET / PBT is P
ET 80 to 95% by weight / PBT 5 to 20% by weight, preferably PET 80 to 90% by weight / PBT 10
Is in the range of up to 20% by weight. When the blending ratio of PBT is less than 5% by weight, the effect of preventing vertical cracking of the obtained flat yarn is insufficient, while when it exceeds 20% by weight, the melt viscosity of the extruder becomes high and the moldability is deteriorated, which is not preferable. .

In the present invention, it is preferable to add linear low density polyethylene to the composition of PET / PBT because the moldability of the flat yarn is improved. Linear low-density polyethylene (hereinafter referred to as LLDPE) is a copolymer of ethylene and α-olefin consisting of ethylene and an α-olefin having 3 or more carbon atoms, and the α-olefin as a comonomer is carbon. Examples thereof include α-olefins having 3 or more, preferably 4 or more, and more preferably 6 to 20 carbon atoms, such as 1-hexene, 4-methyl-1-pentene, 1-octene and 1-decene. The polymerization catalyst can be produced using a coordination polymerization catalyst such as a Ziegler catalyst or a metallocene catalyst.

Particularly, it is preferable to use LLDPE having the following physical properties using a metallocene catalyst. 1) Melt flow rate (hereinafter abbreviated as MFR) is 0.
It is 1 to 30 g / 10 minutes, preferably 1 to 5 g / 10 minutes. If the MFR is less than 0.1 g / 10 min, the moldability is poor, and if it exceeds 30 g / 10 min, the strength is lowered, which is not preferable. 2) density 0.86~0.94g / cm ^3, preferably 0.89~0.93g / cm ^3. Density is 0.86g
If it is less than / cm ³ , the stretchability is poor and the production is difficult, and if it exceeds 0.94 g / cm ³ , the flexibility is poor and it is not preferable. 3) Maximum peak temperature (Tm) by DSC is 80-12
The temperature is 5 ° C, preferably 90 to 120 ° C. If the maximum peak temperature (Tm) by DSC is less than 80 ° C, the difference from the stretching temperature becomes too small, and if it exceeds 125 ° C, the optimum stretching 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. If Mw / Mn 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.

A method for producing the above ethylene / α-olefin copolymer is described in JP-A-58-19309 and JP-A-5-30939.
9-95292, JP-A-60-35005, JP-A-60-35006, and JP-A-60-35.
It can be obtained by copolymerizing ethylene and α-olefin using a metallocene catalyst described in JP-A No. 007, JP-A-60-35008, JP-A-60-35009 and the like.

The blending ratio with the above-mentioned PET / PBT / LLDPE is in the range of PET 50 to 90% by weight / PBT 5 to 20% by weight / LLDPE 5 to 30% by weight, preferably PET 60 to 80% by weight / PBT 10 to 20% by weight. %
/ LLDPE is in the range of 10 to 20% by weight. When the blending ratio of PBT is less than 5% by weight, the effect of preventing vertical cracking of the obtained flat yarn is insufficient, while when it exceeds 20% by weight, the melt viscosity of the extruder becomes high and the moldability is deteriorated, which is not preferable. . On the other hand, if the blending ratio of LLDPE is less than 5% by weight, the effect of improving the moldability of the flat yarn decreases, while if it exceeds 30% by weight, the heat resistance of the flat yarn decreases, which is not desirable.

In the extrusion molding of the above composition, it is desirable to add an inorganic filler for the purpose of improving the molding processability, smoothness, surface appearance and the like of the flat yarn and suppressing vertical cracks. As the inorganic filler, calcium carbonate, talc, silica, clay, hydrotalcite, etc. are preferably used. Of these, calcium carbonate is preferred. The compounding amount of the inorganic filler is preferably 0.5 to 5 parts by weight, and more preferably 1 to 3 parts by weight, based on 100 parts by weight of the composition of PET and PBT. If the blending amount is less than 0.5 parts by weight, it is difficult to achieve the above object, and if it exceeds 5 parts by weight, the flexibility of the flat yarn is lost and yarn breakage occurs, which is not preferable.

The form of the fibrous body of the polyethylene terephthalate resin composition used in the base cloth for artificial turf of the present invention is as follows:
Single-layer type or multi-layer type such as flat yarn obtained by slitting and stretching film, split yarn obtained by splitting flat yarn, monofilament obtained by stretching filament extruded from a circular or irregular nozzle, and multifilament obtained by converging low-definition filament. Type, core-sheath type, side-by-side compound yarns, etc. can be used without limitation.

As a method of molding a flat yarn using the composition of PET and PBT or the composition of PET, PBT and LLDPE as the form of the fibrous body, the composition is melt-extruded by an extruder and T A film is formed by a die method or an inflation method, the film solidified by cooling is slit, then heat-stretched and further subjected to heat relaxation treatment to form a flat yarn. The extrusion temperature is in the range of 270 to 290 ° C, and the stretching temperature is 10
It is in the range of 0 to 140 ° C., and the thermal relaxation temperature is 120.
The range of ˜160 ° C. is preferred. As the heat treatment method, any of a hot roll method, an oven method, a hot plate method, and the like can be adopted, but the hot plate method is preferable. Further, the stretching ratio is in the range of 3 to 15 times, preferably 3 to 6 times. The flat yarn, which constitutes a base cloth for artificial grass, has a single yarn fineness in the range of 500 to 5000 decitex (dt).

The base fabric of the fibrous body is not limited in its form and structure. For example, in the case of woven fabric, plain weave,
Twill weave, entangled weave, warp weave and the like can be mentioned, and it is desirable that the flat yarn has a driving density of 3 to 20 yarns / inch. Further, in the case of knitted fabric, Russell knitting, tricot knitting, Milanese knitting, etc., and in the case of non-woven fabric, spunbonded non-woven fabric, flash spun non-woven fabric, melt blown non-woven fabric, etc. Things etc. are mentioned.

The thus obtained primary base cloth, which is a woven cloth made of fibers of polyethylene terephthalate resin composition or the like, is used as a base cloth, and a flat yarn or monofilament pile yarn made of the polyethylene terephthalate resin composition is added to the base cloth. A large number of tufts are planted by tufting, the top of the pile loop is cut to form turf leaves, and then the back side of the base cloth is lined with a latex material and the pile thread is fixed to the primary base cloth to fix the artificial turf. Is manufactured. The backing layer is mainly made of the same polyvinyl chloride, polyolefin resin, etc. as in the conventional case, and the backing processing temperature is in the range of about 150 to 190 ° C.

The polyethylene terephthalate resin composition used in the present invention includes an antioxidant, an ultraviolet absorber, a light stabilizer, a lubricant, an antistatic agent, a pigment and a flame retardant within the scope of the present invention. Inorganic fillers, nucleating agents, foaming agents, dispersants, and other commonly used additives may be added.

[0021]

[Example] Example 1 Crush, melt-extrude, and pelletize collected PET bottles
And dried at 160 ° C. for 5 hours, intrinsic viscosity = 0.65
100 weight of dl / g recycled PET resin (melting point = 254 ° C)
Polybutylene terephthalate with a specific part and intrinsic viscosity [η] of 0.85
15 parts by weight of talate resin (melting point = 228 ° C.) and metallo
Ethylene / α-olefins produced using sen catalysts
Copolymer (MFR = 2.5 g / 10 min, density = 0.92
g / cm ^Three, Tm = 115 ° C., Mw / Mn = 2.8) 1
A 65 mmφ extruder using a composition containing 5 parts by weight
To form a film by the T-die method at a melting temperature of 275 ° C
did. Slit the cooled and solidified film and
Stretched 4 times and heat-relaxed at 150 ℃ to obtain a fineness of 1000
Got a dt flat yarn. History of this flat yarn
It is used for yarn and the driving density is 16 × by the Sruzer loom.
Obtaining a flat weave flat yarn cloth with 16 yarns / inch
It was cloth. Moldability of the above flat yarn is good,
It is flexible, has no vertical cracks, and has good wear resistance.
Met. Primary flat yarn cloth obtained above
Used for base cloth, the above polyethylene terephthalate resin composition
A flat yarn made of objects is used as a pile yarn and tufted.
Planted by the casting method and using polyvinyl chloride on the back side
Lining at a temperature of 150 ° C
Was formed. This artificial grass also has productivity in tufting
Good and excellent in appearance without heat shrinkage during lining
Met.

Example 2 Crush, melt-extrude, and pelletize collected PET bottles
And dried at 160 ° C. for 5 hours, intrinsic viscosity = 0.65
100 weight of dl / g recycled PET resin (melting point = 254 ° C)
Polybutylene terephthalate with a specific part and intrinsic viscosity [η] of 0.85
15 parts by weight of talate resin (melting point = 228 ° C.) and metallo
Ethylene / α-olefins produced using sen catalysts
Copolymer (MFR = 2.5 g / 10 min, density = 0.92
g / cm ^Three, Tm = 115 ° C., Mw / Mn = 2.8) 1
Calcium carbonate included in the composition containing 5 parts by weight
Resin blended with 4 parts by weight of masterbatch of 40% by weight
Using the composition, a melting temperature of 27 using a 65 mmφ extruder
A film was formed by a T-die method at 5 ° C. Solidified by cooling
Slit the film and stretch it 4 times at 120 ° C,
A flat yarn with a fineness of 1000 dt that is heat-relaxed at 0 ° C.
Got Use this flat yarn for warp and weft
With a loom weaving machine with a driving density of 16 × 16 / inch
A woven flat yarn cloth was obtained and used as a base fabric. Hula above
The moldability of the yarn is good and it has flexibility
Neither was seen at all, and the wear resistance was good. Get above
Using the flat yarn cloth thus prepared as the primary backing cloth,
Flat made of polyethylene terephthalate resin composition
Planted by tufting method using yarn as pile yarn
Then, using polyvinyl chloride on the back side, backing temperature
Lining was performed at 150 ° C. to form artificial grass. this
Artificial grass also has good productivity during tufting
There was no heat shrinkage in the process and it was excellent in appearance.

Example 3 The recovered PET bottle was crushed, melt-extruded, pelletized, and dried at 160 ° C. for 5 hours, intrinsic viscosity = 0.65.
Containing 100 parts by weight of dl / g recycled PET resin (melting point = 254 ° C.) and 8 parts by weight of polybutylene terephthalate resin (melting point = 228 ° C.) having an intrinsic viscosity [η] of 0.85, calcium carbonate is contained. Using a resin composition containing 4 parts by weight of a masterbatch having an amount of 40% by weight, 65 mmφ
A film was formed by a T-die method at a melting temperature of 275 ° C. by an extruder. Slit the cooled and solidified film,
Stretched 5 times at 0 ° C and heat-relaxed at 150 ° C to give a fineness of 1
A flat yarn of 000 dt was obtained. The above flat yarn was slightly inferior in moldability and flexibility, but the flat yarn cloth obtained by using the flat yarn was used as a primary backing fabric, and the flat yarn made of the polyethylene terephthalate resin composition was used as a pile yarn for tufting. The artificial turf was formed on the back surface of the artificial turf by using a polyvinyl chloride method and lining at a backing temperature of 150 ° C. The artificial turf had good productivity during tufting and had excellent appearance without heat shrinkage during lining.

Comparative Example 1 The recovered PET bottle was crushed, melt-extruded, pelletized, and dried at 160 ° C. for 5 hours. Intrinsic viscosity = 0.65
Using a resin composition prepared by mixing 100 parts by weight of dl / g recycled PET resin (melting point = 254 ° C.) with 4 parts by weight of a masterbatch having a calcium carbonate content of 40% by weight, 65 mmφ
A film was formed by a T-die method at a melting temperature of 275 ° C. by an extruder. Slit the cooled and solidified film,
Stretched 5 times at 0 ° C and heat-relaxed at 150 ° C to give a fineness of 1
A flat yarn of 000 dt was obtained. The flat yarn had insufficient moldability, poor flexibility, easy vertical cracking, and insufficient abrasion resistance.

[0025]

As explained above, the artificial turf base fabric of the present invention has a moldability obtained by blending a polyethylene terephthalate resin with a polybutylene terephthalate resin, preferably a specific amount of linear low density polyethylene. It is excellent in impact resistance, can form a flat yarn without vertical cracks, and is suitably used as a base fabric for artificial grass.

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Claims (5)

[Claims] 1. A polyethylene terephthalate resin 80-
95% by weight and polybutylene terephthalate resin 5-2
A base cloth for artificial turf comprising a composition of 0% by weight. 2. A polyethylene terephthalate resin 50 to
90% by weight, polybutylene terephthalate resin 5-20
A base fabric for artificial turf, which comprises a composition of 5% by weight and linear low-density polyethylene of 5 to 30% by weight. 3. The base cloth for artificial turf according to claim 1, wherein 0.5 to 5 parts by weight of an inorganic filler is mixed with 100 parts by weight of the composition. 4. A linear low density polyethylene produced by using a metallocene catalyst and having a density of 0.86 to 0.94 g / cm 3.
^The base cloth for artificial turf according to claim 2, which is in the range of ³ . 5. An artificial turf using the base cloth for artificial turf according to claim 1.