JPH11200180A - Polypropylene meshed sheet for construction work - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a light meshed sheet for construction work having high strength, excellent in flexibility, hardly causing disorder of a crossing point and having a flame retardancy. SOLUTION: This meshed sheet is composed of a base material formed out of a meshed body obtained by carrying out a weaving operation by using a composite polypropylene filament composed of a core layer consisting of a polypropylene multifilament and a sheath layer consisting of a polypropylene- based resin composition as warp and/or weft, and the crossing points of the warp and the weft are fused by the propylene-based resin composition forming the sheath layer to fix the crossing points.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an architectural mesh sheet made of polypropylene resin.

[0002]

2. Description of the Related Art A mesh sheet for construction work is used as a scaffold at a construction work site such as a building or a house to prevent bolts and other construction materials from falling from the construction site and to ensure the safety of passers-by. Such a sheet is attached to the outer surface of the temporary structure. These are usually made of a flammable thermoplastic resin sheet, and there is a danger that they will spread due to welding sparks or the like. For that, JISA
8952 “Building Work Sheet” Appendix Table 1 defines flame retardant standards, and it is customary that various flame retarding treatments are applied so as to pass the standards.

[0003] More specifically, mesh sheets for building works are often formed by laminating a woven or knitted fabric using a filament yarn such as polyester or nylon with a polyvinyl chloride-based resin. The advantage is that the strength of the woven and knitted fabric is sufficient and it is flexible, and the flame resistance is given by the polyvinyl chloride resin.
As a disadvantage, the laminated polyvinyl chloride resin has problems such as dirt and odor due to bleeding of the plasticizer,
In addition, due to the relatively heavy weight, labor is required for the spreading work at a high place, and furthermore, handling is difficult, such as generation of toxic gas during incineration in disposal. Further, the polyvinyl chloride-based resin has a problem that it is hardened at a low temperature, is difficult to handle, and is brittle, and its strength is reduced.

In order to solve such a problem, in recent years,
A mesh sheet made of polyolefin filaments having excellent filament formability and generating no toxic gas is used. In particular, polypropylene monofilaments having excellent mechanical properties are often used. However,
A woven or knitted fabric using a polypropylene monofilament as the warp has poor flexibility due to the rigidity of the polypropylene, is difficult to fold, and has an inconvenience that it is not easy to handle in a stretching operation at a construction site.

[0005]

SUMMARY OF THE INVENTION In view of the above circumstances, it is an object of the present invention to provide a polypropylene mesh sheet for building works which is lightweight, high in strength and excellent in flexibility and has flame retardancy.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and comprises a core layer composed of a polypropylene multifilament and a sheath layer composed of a polypropylene resin composition containing a flame retardant. A mesh body formed by weaving and knitting using a composite polypropylene filament as a warp and / or a weft, and the warp intersections of the mesh are welded and filled with a polypropylene-based resin composition forming a sheath layer. The object of the present invention is to provide a polypropylene mesh sheet for architectural works, characterized in that the above-mentioned problem is solved.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The polypropylene used in the polypropylene multifilament of the present invention is preferably a polypropylene having high crystallinity and a high stretching effect. Specifically, propylene homopolymer, propylene
Examples include an ethylene block copolymer and a propylene-ethylene random copolymer. Among these, a polypropylene homopolymer having excellent moldability and high strength is preferable, and particularly, the isotactic pentad fraction is 0.9.
Highly crystalline polypropylene of 5 or more is preferred. These polypropylenes may be used alone or in combination of two or more. The melt flow rate of the polypropylene (hereinafter abbreviated as MFR) is 5 to 5.
50 g / 10 min. Is preferred, and 10 to 30 g / 10 min.
min. is more preferable.

[0008] The method for producing the polypropylene multifilament is not particularly limited, and a known multifilament production method is appropriately employed. The fineness of the multifilament is preferably 100 to 1500 denier (hereinafter, referred to as d), and more preferably 300 to 1000 d.

[0009] A core-sheath type composite polypropylene filament is formed by using such a polypropylene multifilament as a core layer and using a polypropylene resin composition containing a flame retardant as a sheath layer.

The polypropylene resin used for the sheath layer is not particularly limited, but preferably has a difference in melting point from that of the polypropylene used for the core layer by 10 or more.
C. or higher, more preferably 20 ° C. or higher. Specifically, a propylene-ethylene block copolymer or a random copolymer, or a syndiotactic pentad having a syndiotactic pentad ratio of 0.7 or higher is specifically used. Low-melting polypropylene resins such as tic polypropylene. These may be used alone or in combination of two or more.

The propylene-ethylene copolymer is a block or random copolymer produced by a known method and has an ethylene content of 1 to 10% by weight, preferably 4% by weight.
~ 7% by weight. Among these propylene-ethylene copolymers, a random copolymer having a low melting point is preferable, and the MFR is preferably 0.1 to 30 g / 10 m
in., more preferably in the range of 1 to 10 g / 10 min.

The syndiotactic pentad fraction of the syndiotactic polypropylene is 0.7 or more, preferably 0.8 or more. A method for producing syndiotactic polypropylene is disclosed in JP-A-2-4.
1303, JP-A-2-41305, JP-A-2-274703, JP-A-2-274704, JP-A-3-179005, JP-A-1-790
It can be obtained by polymerizing propylene using a metallocene catalyst described in JP-A-2006-2006 or the like.

The metallocene catalyst is composed of a metallocene compound having an asymmetrical ligand represented by isopropyl (fluorenyl) (cyclopentadienyl) zirconium dichloride and a co-catalyst such as methylaluminoxane (MAO). Catalyst.

The above syndiotactic polypropylene is a copolymer of propylene homopolymer or an α-olefin other than propylene such as ethylene, butene-1, 4-methylpentene-1 or the like without departing from the scope of the present invention. They can be combined. The MFR of the syndiotactic polypropylene is preferably 0.1.
1 to 30 g / 10 min., More preferably 1 to 10 g
/ 10 min.

As the flame retardant used in the present invention, known flame retardants such as halogen-based, phosphorus-based, and inorganic-based flame retardants are used. Halogen-based flame retardants are preferred, and brominated flame retardants are particularly preferred.

Examples of the bromine flame retardant include aromatic bromine flame retardants such as tetrabromobisphenol A, decabromodiphenyl oxide, octabromodiphenyl oxide, bisdibromopropyl ether tetrabromobisphenol S, hexabromocyclododecane, and dibromoethyl. Examples thereof include alicyclic brominated flame retardants such as dibromocyclohexane, and liquid brominated flame retardants such as pentabromodiphenyl oxide and tetrabromodiphenyl oxide. These may be used alone or as a mixture of two or more.

It is preferable to use antimony trioxide as a flame retardant aid in combination with the bromine flame retardant in view of improving the flame retardant effect. The mixing ratio of the brominated flame retardant to antimony trioxide is not particularly limited, but is 2: 1 to 1
3: 1 is preferred.

It is preferable that the bromine-based flame retardant and the flame retardant auxiliary be blended in an amount of 0.1 to 10% by weight based on the total weight of the mesh sheet.
~ 2% by weight is more preferred. 0.1% by weight
If it is less than 10%, the flame retardancy is insufficient. If it exceeds 10% by weight, the effect of the flame retardancy is not further improved and it is not economical. As a specific compounding method, it may be 1 to 20% by weight, preferably 3 to 10% by weight based on the sheath layer component.

The MFR of the polypropylene resin composition used in the above-mentioned sheath layer is selected from the range of 1 to 30 g / 10 min., Preferably 5 to 20 g / 10 min. If the MFR is less than 1 g / 10 min., The fluidity will be poor, and if it exceeds 30 g / 10 min., Mechanical properties such as tensile strength will be undesirably reduced.

The method for producing the composite polypropylene filament is not particularly limited, and a known method is employed. That is, a polypropylene multifilament forming a core layer is supplied from a center discharge hole of a die having two well-known discharge holes formed concentrically, and a polypropylene resin composition forming a sheath layer is melt-kneaded by an extruder. And 2
The sheath layer is extruded from the outer layer of the layer die and coated to obtain a composite polypropylene filament.

The fineness of the formed composite polypropylene filament is preferably from 500 to 3000 d,
2000d is more preferred. If the fineness is less than 500d, the strength is inferior, and if it exceeds 3000d, the flexibility is undesirably reduced.

The composition ratio of the core layer / sheath layer in the composite polypropylene filament is preferably 50/50 to 90/10, and more preferably 60/40 to 80/20.

The composite polypropylene monofilament formed by the above method is woven and knitted by a conventional loom or knitting machine using these as warp and / or weft to form a mesh body. The weaving and knitting structure of the mesh body is not particularly limited, as long as it has coarseness and air permeability. Concretely, plain weave, woven weave,
Various woven fabrics such as leno weave can be mentioned, and the knitted fabric may be either a flat knit or a warp knit, and specifically, a tricot knit, a Miranese knit, a Russell knit or the like.

In the present invention, a polypropylene multifilament, a polypropylene flat yarn, a laminated composite polypropylene flat yarn, a polypropylene split yarn, a laminated composite polypropylene split yarn, a polypropylene monofilament, a core-sheath composite polypropylene are used in combination with the composite polypropylene filament. Various filaments such as monofilaments can be used and interwoven without departing from the spirit of the present invention. Preferably, the amount of the various filaments used is less than 50% by weight of the total warp.

Known additives such as a flame retardant, an ultraviolet absorber, a light stabilizer and an acid adsorbent can be added to the various filaments without departing from the spirit of the present invention. These additives may be directly added to a single-layer filament, and may be added to an outer layer, an inner layer, or an inner or outer layer of a composite filament.

Specific examples of the above-mentioned ultraviolet absorber include 2,2
Benzophenone UV absorbers such as 4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-octoxybenzophenone, 5,5'-methylenebis (2-hydroxy-4-methoxybenzophenone), (2'-hydroxy-5'-methylphenyl) benzotriazole, 2- (2'-hydroxy-
5'-t-octylphenyl) benzotriazole, 2-
(2-hydroxy-3 ', 5'-di-t-butylphenyl) -5
-Chlorobenzotriazole, 2- (2'-hydroxy-
Benzotriazole UV absorbers such as 3'-t-butyl-5'-methylphenyl) -5-chlorobenzotriazole, 2,2'-methylenebis (4-t-octyl-6-benzotriazole) phenol, resorcinol Monobenzoate, 2,4-di-t-butylphenyl-3'-5'-di-t-butyl-4'-hydroxybenzoate, hexadecyl-3-5
And benzoate-based ultraviolet absorbers such as -di-t-butyl-4-hydroxybenzoate. The compounding ratio of the ultraviolet absorber is preferably 0.1 to 5% by weight, more preferably 0.5 to 2% by weight, based on the sheath layer component.

Specific examples of the above-mentioned acid adsorbent include hydrotalcite and metal soap. Examples of the metal soap include calcium stearate and magnesium stearate. The mixing ratio of the acid adsorbent is preferably 0.1 to 5% by weight, more preferably 0.1% by weight, based on the sheath layer component.
5 to 2% by weight.

The mesh sheet for construction work preferably has a porosity indicating an open state of 20 to 80%, and more preferably 30 to 70%, and conforms to Japanese Industrial Standard JIS A89.
At 52, the mesh size is 12 mm or less, and is selected depending on the purpose and application. The basis weight is preferably 8
0~400g / m ^2, more preferably from 100 to 250
g / m ² .

In the present invention, the filling is performed by subjecting the mesh body to a heat treatment by using a known method such as a hot plate contact type, a hot roll type, an infrared irradiation type, a high frequency welder type, and a hot air tenter type. The sealing process is performed by welding with a polypropylene-based resin composition that forms a sheath layer at the yarn intersection.

This mesh body is cut into a predetermined size,
The polypropylene mesh sheet for construction work of the present invention can be formed by edging, eyelets, or the like.
It is preferable to use a material having a performance that meets the flameproofing standard specified in 952.

The polypropylene and the polypropylene resin composition used in the present invention may contain other thermoplastic resins or an antioxidant, a light stabilizer, a dispersant, a lubricant, an antistatic agent without departing from the spirit of the present invention. Ordinarily used additives such as a pigment, an inorganic filler, an inorganic flame retardant, a crosslinking agent, a foaming agent, and a nucleating agent may be blended.

[0032]

[Examples] Test method 1. Tensile test: compliant with JISA8952 2. Flame retardancy test: compliant with JISA8952

Example 1: Polypropylene (MFR = 20
g / 10 min., density = 0.90 g / cm ³ , Tm = 1
(58.0 ° C.) to form a multifilament having a total fineness of 680 d / 120 f, which was used as a core layer.

In the sheath layer, a propylene-ethylene random copolymer (MFR = 16.5 g / 10 min., Density =
0.90 g / cm ³ , Tm = 128.4 ° C.) 93% by weight
And 100 parts by weight of a polypropylene propylene resin composition containing 7% by weight of a master batch containing a flame retardant or the like,
0.5 parts by weight of (2'-hydroxy-3'-tert-butyl-5'-methylphenyl) 5-chlorobenzotriazole (trade name: Tinuvin 326) as an ultraviolet absorber, and hydrotalcite (trade name: as an acid adsorbent) DHT-4A)
One part by weight and 1.9 parts by weight of cyanine green pigment were blended and used. The masterbatch containing a flame retardant etc. is composed of 60% by weight of a propylene-ethylene random copolymer, 15% by weight of bisdibromopropyl ether tetrabromobisphenol S, 15% by weight of decabromodiphenyl oxide, and 10% by weight of antimony trioxide as brominated flame retardants. weight%
Is blended.

The composite polypropylene filament was formed by supplying a polypropylene multifilament of a core layer from a molding die having two layers of discharge holes concentrically and melt-extruding a polypropylene resin composition of a sheath layer with an extruder. . The fineness of the obtained composite polypropylene filament was 1200 d.

Using the composite polypropylene filament thus obtained as a weft, a plain weave mesh body having a weft of 16 / inch was woven. Mesh weight is about 2
The porosity was 05 g / m ² and the porosity was 35%. This mesh body was fused at 145 ° C. by a hot air tenter type heating process at the intersection of the warp yarns, subjected to a sealing process, and subjected to an edge process to obtain a 1.8 × 5.1 m polypropylene mesh sheet for construction work. Was.

The tensile strength of the polypropylene mesh sheet for building work is 75 kgf / 3 cm, and the maximum elongation is 2 kgf / 3 cm.
1.8%. This value passed the building work sheet 2 standard of JISL1091. Also,
It had the flexibility to be folded in the weft direction, and the handleability was good. In the flame retardancy test, the number of times of flame contact was 4 times,
It has passed the SA8952 flameproof standard. Further, the tensile strength after irradiation with a weatherometer for 200 hours and 400 hours was 84.6% and 58.4%, and the weather resistance was good.

Example 2: As the polypropylene resin used for the sheath layer, syndiotactic polypropylene (syndiotactic pentad fraction = 0.82, MFR = 6.8)
0 g / 10 min., Mw / Mn = 2.0, Tm = 130
° C), except that Example 1 was used.

The obtained composite polypropylene filament was used as a warp and a weft to give a warp of 26 filaments / inch and a weft of 16.
A book / inch plain-woven mesh body was woven. The basis weight of the mesh body was about 112 g / m ² , and the porosity was 32%. This mesh body is subjected to a filling process by fusing intersection points of warp yarns at 140 ° C. by a heating process of a hot air tenter type,
The peripheral edge was processed to obtain a 1.8 × 5.1 m polypropylene mesh sheet for construction work.

The tensile strength of the above-mentioned polypropylene mesh sheet for construction work is 77 kgf / 3 cm, and the maximum elongation is 2 kg.
It was 3.2%. This value passed the building work sheet 2 standard of JISL1091. Also,
It had the flexibility to be folded in the weft direction, and the handleability was good. In the flame retardancy test, the number of times of flame contact was 4 times,
It has passed the SA8952 flameproof standard. The tensile residual strength after irradiation with the weatherometer for 200 hours and 400 hours was 85.4% and 57.8%, and the weather resistance was good.

[0041]

As described above, the polypropylene mesh sheet for architectural construction of the present invention has a polypropylene multifilament core layer and a polypropylene resin containing a specific low melting point polypropylene resin and a flame retardant in a sheath layer. By using a composite polypropylene filament using the composition for warp and / or weft,
While having flexibility, it can perform good filling process with good productivity, and there is no thermal deterioration at the time of filling process,
It was possible to maintain high strength due to the stretching effect.
Furthermore, it has better cold resistance and antifouling properties than the conventionally used polyvinyl chloride coating type.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI E04G 21/32 E04G 21/32 B

Claims (1)

[Claims] 1. A mesh formed by weaving and knitting a composite polypropylene filament composed of a core layer composed of a polypropylene multifilament and a sheath layer composed of a polypropylene-based resin composition containing a flame retardant as a warp and / or a weft. A polypropylene mesh sheet for construction work, wherein a warp yarn intersection of the mesh body is welded and filled with a polypropylene-based resin composition forming a sheath layer.