JPH11101000A - Polypropylene mesh sheet for building work - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a building work mesh sheet having lightweight and high strength and excellent in flexibility, wrinkleproof efficiency, folding efficiency, flame-retardancy and weatherability without slippage between meshes. SOLUTION: Polypropylene multi-filament 2 and composite polypropylene mono-filament 3 as warp and woof are woven to obtain a mesh sheet 1. In that case, the composite polypropylene mono-filament 3 is constituted of a core layer 4 of polypropylene higher melting point component containing an optical stabilizer and a sleeve layer 5 of polypropylene lower melting component containing containing flame retardant, ultraviolet radiation absorbent and acid absorbent, and intersections 6 with warp and woof in the mesh are thermally contacted with the polypropylene lower melting point component to make wood filling.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mesh sheet for architectural work, and more particularly, to a ventilated sheet body which is spread on the outer periphery of a construction work site for the purpose of preventing danger. The present invention relates to a mesh sheet for construction work which has excellent weather resistance, is flexible, lightweight, and prevents misalignment.

[0002]

2. Description of the Related Art As a mesh sheet for construction work, a sheet made of thermoplastic resin, which is usually flammable, is frequently used, and there is a danger that the sheet will spread due to welding sparks or the like. JIS-A8952 "Mesh sheet for construction work"
Table 1 shows the standard of flame retardancy, and various flame retarding treatments are usually applied to pass this standard.

Heretofore, it has been known that a mesh sheet made of flammable fibers such as nylon or polyester is coated with a polyvinyl chloride resin so as to impart flame resistance and simultaneously prevent misalignment. However,
The polyvinyl chloride resin has a problem that toxic chlorine gas is generated at the time of combustion and a problem such as dirt and smell due to bleeding of the plasticizer. Further, since mesh sheets for construction work are often used outdoors, they are required to have weather resistance because they are exposed to sunlight for a long time.

[0004] In general, as a method of making a thermoplastic resin flame-retardant, a method of blending a flame retardant with the thermoplastic resin is adopted. Among them, a halogen-based flame retardant which has a high flame retardant effect and is easy to handle is blended. The flame retardation treatment is widely performed. As a method of improving weather resistance, a method of adding an ultraviolet absorber, a light stabilizer, or the like is usually adopted. However, when a halogen-based flame retardant is used in combination with an ultraviolet absorber or a light stabilizer, the halogen separated from the flame retardant has an antagonistic effect with the ultraviolet absorber or the light stabilizer. There was no problem.

In order to improve the above problem, a method using a hydrotalcite compound in addition to a flame retardant, a light stabilizer and an ultraviolet absorber (JP-A-5-86230, JP-A-5-117451), Techniques such as a method of blending a metal oxide such as antimony oxide with a bromine-containing flame retardant and a light stabilizer (JP-A-5-93098) are disclosed. Multi-layered synthetic fibers containing a flame retardant as a component
No. 91314) has been proposed.

By the way, those using monofilaments as the warp yarns of the mesh sheet are inferior in flexibility due to the rigidity of the monofilament, and are difficult to fold. The disadvantage that it is not good occurs. Therefore, flexibility and foldability can be imparted by using one of the warp yarns as a monofilament and the other as a multifilament, but it is difficult to mix a flame retardant into the multifilament, so that a large amount of monofilament is difficult. I have to mix a flame retardant. However, when a large amount of additives such as a flame retardant are blended, a trade-off phenomenon occurs such that the mechanical properties of the formed monofilament decrease.

Further, as a thermoplastic resin used as a raw material of the monofilament, a monofilament prepared by mixing a flame retardant with polyethylene has a drawback that the elasticity is inferior and wrinkles are hardly recovered. A monofilament prepared by mixing a flame retardant with polyester is hard and has a good texture. However, there is also a problem that a monofilament in which a flame retardant is blended with nylon becomes expensive.

[0008]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a construction work which is lightweight, high-strength, excellent in flexibility, anti-wrinkling property and folding property, has no misalignment, and is excellent in flame retardancy and weather resistance. It is to provide a mesh sheet for use.

[0009]

As technical means for solving the above-mentioned problems, the present invention relates to a polypropylene multifilament (A) having a core layer comprising a polypropylene high melting point component and a polypropylene layer containing a flame retardant. A mesh sheet woven using a composite polypropylene monofilament composed of a sheath layer composed of a melting point component as either a warp or a weft, and the weight ratio of (A) / (B) in the total warp is 40. / 60-60 / 4
The polypropylene mesh sheet for architectural works is characterized in that it is 0 and the weft yarn intersections of the mesh sheet are welded and filled with a low melting point component of polypropylene.

In a preferred embodiment, one of the warp and the weft is (A) a polypropylene multifilament and the other is a (B) composite polypropylene monofilament, and the (B) composite polypropylene monofilament contains a light stabilizer. It is characterized by comprising a core layer composed of a polypropylene high melting point component and a sheath layer composed of a polypropylene low melting point component containing a flame retardant, an ultraviolet absorber and an acid adsorbent.

[0011] Such a polypropylene mesh sheet for construction work can provide high strength by a drawing effect by using a composite monofilament at a predetermined ratio for either a warp or a weft, and can be subjected to a sealing process. Performance can be improved. In addition, since the flame retardant is contained in the sheath layer, there is no antagonism with the light stabilizer contained in the core layer, and the use of an acid adsorbent can prevent adverse effects on the ultraviolet absorber. Therefore, the flame retardancy is good and the weather resistance is excellent.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION The polypropylene used for the polypropylene multifilament constituting the mesh sheet of the present invention is propylene homopolymer, propylene-
A known polypropylene copolymer such as an ethylene block copolymer or a random copolymer or a mixture thereof, and among them, a propylene homopolymer is preferable for a multifilament capable of obtaining a high strength, and especially an isotactic polymer. Those having a tic pentad ratio of 0.95 or more are suitably employed. The melt flow rate of the polypropylene (hereinafter, abbreviated as MFR) is 5 to 50 g / 1.
0 min. Is preferable, and 10 to 30 g / 10 min. Is more preferable.

The method for producing the polypropylene multifilament is not particularly limited, and a known method for producing a multifilament can be employed. The fineness of the polypropylene multifilament is preferably 100 to 5000 denier (hereinafter referred to as d), and is 500 to 3000 d.
Is more preferred.

Next, the composite polypropylene monofilament is a composite polypropylene monofilament composed of a core layer composed of a polypropylene high melting point component and a sheath layer composed of a polypropylene low melting point component.

As the polypropylene high melting point component,
A propylene homopolymer is preferred, and those having an isotactic pentad ratio of 0.95 or more are particularly preferably employed. The MFR of this polypropylene is 0.1 to 10 g /
10 min. Is preferable, and 0.5 to 5 g / 10 min. Is more preferable. If the MFR is less than 0.1 g / 10 min., The difference from the MFR of the polypropylene low melting point component of the sheath layer becomes large, and the workability of the monofilament deteriorates. If the MFR exceeds 10 g / 10 min., The strength as a monofilament is inferior.

[0016] The polypropylene low melting point component includes:
Propylene-ethylene block copolymer or random copolymer, syndiotactic pentad fraction of 0.
Seven or more syndiotactic polypropylenes are preferably used.

As the propylene-ethylene copolymer, either a block or random copolymer produced by a known method is used. The ethylene content is between 1 and 10% by weight, preferably between 4 and 7% by weight. Among these propylene-ethylene copolymers, a random copolymer having a low melting point is preferred. The MFR of the propylene-ethylene copolymer is preferably 0.1 to 30 g / 10 mi.
n, more preferably 1 to 10 g / 10 min.

The above-mentioned syndiotactic polypropylene has a syndiotactic pentad fraction of at least 0.7, preferably at least 0.8. A method for producing this syndiotactic polypropylene is disclosed in
-41303, JP-A-2-41305, JP-A-2-274703, JP-A-2-274704
JP-A-3-179005, JP-A-3-17905
It can be obtained by polymerizing propylene using a metallocene catalyst described in JP-A-9006.

The metallocene catalyst is composed of, for example, a metallocene compound having an asymmetrical ligand represented by isopropyl (fluorenyl) (cyclopentadienyl) zirconium dichloride and methylaluminoxane (MAO) as cocatalysts. Catalyst.

The above-mentioned syndiotactic polypropylene is a propylene homopolymer or a copolymer with 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. It does not matter. The MFR of the syndiotactic polypropylene is preferably 0.1.
３０30 g / 10 min., More preferably 1-10 g /
It is selected in the range of 10 min.

The syndiotactic polypropylene used in the present invention can be used in combination with a propylene-ethylene copolymer having an ethylene content of 1 to 10% by weight. It is also possible to mix other polyolefin-based resins other than the ethylene copolymer. When a propylene-ethylene copolymer is used in combination with syndiotactic polypropylene, the blending ratio of the propylene-ethylene copolymer to be blended is 5 to 95% by weight, preferably 10 to 90% by weight.
% By weight. If the blending ratio of the propylene-ethylene copolymer exceeds 95% by weight, the characteristics of syndiotactic polypropylene cannot be utilized.

The composition ratio of the core layer / sheath layer in the composite polypropylene monofilament used in the present invention is as follows:
50 / 50-90 / 10 is preferred, and 60 / 40-80.
/ 20 is more preferable.

The method for producing the above-mentioned composite polypropylene monofilament is not particularly limited, and a polypropylene high melting point component and a polypropylene low melting point component are melt-kneaded by an extruder to form a die having two concentric discharge holes. It can be obtained by supplying a core layer composed of a high melting point component of polypropylene from the central discharge hole, extruding and covering a sheath layer composed of a low melting point component of polypropylene on the outer surface thereof, and performing a stretching treatment or the like. The hot stretching is performed at a temperature of 90 to 140 ° C. at a temperature lower by 5 ° C. than the melting point of the high melting point component of polypropylene. Next, an annealing treatment is performed at 100 to 150 ° C. Stretching ratio is usually 5 to 15 times,
Preferably it is 8 to 12 times.

The fineness of the composite polypropylene monofilament is preferably 300 to 1000 d, and
700d is more preferred. If the fineness is less than 300d, the strength is poor, and if it exceeds 1000d, the flexibility is undesirably reduced. In terms of physical properties, the tensile strength is preferably 5 g / d or more, more preferably 6 g / d or more. Tensile elongation is 2
0% or more is preferable, and 25% or more is more preferable. That is, if the tensile strength and the tensile elongation are out of the above ranges, the strength as a mesh sheet for building work is insufficient and unsuitable.

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. Flame retardants are preferred, and brominated flame retardants are particularly preferred.

Examples of the brominated flame retardant include aromatic brominated flame retardants such as tetrabromobisphenol A, decabromodiphenyl oxide, octabromodiphenyl oxide, bisdibromopropyl ether tetrabromosulfone, hexabromocyclododecane, and dibromoethyldibromo. Examples thereof include alicyclic brominated flame retardants such as cyclohexane, 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 auxiliary agent in combination with the bromine-based flame retardant from the viewpoint of improving the flame-retardant effect. The compounding ratio of the brominated flame retardant to antimony trioxide is 2: 1-3: 1 is preferred. Further, the compounding ratio of the brominated flame retardant and the flame retardant auxiliary is preferably 0.1 to 10% by weight based on the total weight of the mesh sheet, and 0.1 to 1% by weight is preferable. More preferred. If the compounding ratio is less than 0.1% by weight, the flame retardancy is insufficient, and 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, the content is preferably 1 to 10% by weight, more preferably 3 to 7% by weight, based on the sheath layer component.

The light stabilizer used in the present invention includes bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate and tetrakis (2,2,6,6-tetramethyl-4-piperidyl). ) -1,2,3,4-butanetetracarboxylate, bis (1,2,2,6,6-pentamethyl-4-piperidyl) di (tridecyl) -1,2,3,4-butanetetracarboxylate Rate, 1- (2-hydroxyethyl) -2,2,
Polycondensate of 6,6-tetramethyl-4-piperidinol and diethyl succinate, 1,6-bis (2,2,6,6-tetramethyl-4-piperidylamino) hexane and 2,4-dichloro-
And polycondensates of 6-tertiary octylamino-s-triazine. The mixing ratio of these light stabilizers is preferably 0.1 to 5% by weight, more preferably 0.1% by weight, based on the core layer component.
5 to 2% by weight.

As the ultraviolet absorber used in the present invention, 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-octoxybenzophenone, 5,5'-methylenebis (2-
Benzophenone UV absorbers such as hydroxy-4-methoxybenzophenone), 2- (2'-hydroxy-5'-)
Methylphenyl) benzotriazole, 2- (2'-hydroxy-5'-t-octylphenyl) benzotriazole, 2- (2-hydroxy-3 ', 5'-di-t-butylphenyl) -5-chlorobenzo Triazole, 2- (2'-hydroxy-3'-t-butyl-5'-methylphenyl) -5-chlorobenzotriazole, 2,2'-methylenebis (4-t-octyl-6-benzotriazole) phenol Benzotriazole UV absorbers such as resorcinol monobenzoate, 2,4-di-t-butylphenyl-3'-5'-di-t-
Butyl-4'-hydroxybenzoate, hexadecyl-
Examples include benzoate-based ultraviolet absorbers such as 3-5-di-t-butyl-4-hydroxybenzoate. The blending ratio of these ultraviolet absorbers is preferably 0.1 to 5% by weight, more preferably 0.5 to 2% by weight, based on the sheath layer component.

As the acid adsorbent used in the present invention, hydrotalcite, metal soap and the like are used. Examples of the metal soap include calcium stearate and magnesium stearate. The mixing ratio of these acid adsorbents is
It is preferably 0.1 to 5% by weight, more preferably 0.5 to 2% by weight, based on the sheath layer component.

In the present invention, the method of blending the above-mentioned flame retardant, flame retardant auxiliary, light stabilizer, ultraviolet absorber, acid adsorbent and the like may be either a method of melting and mixing in an extruder or a method of dry blending with a master batch. May be.

The (A) polypropylene multifilament and (B) composite polypropylene monofilament formed by the above method are woven and knitted by a conventional loom or knitting machine using these as either a warp or a weft to form a mesh base material. Is done. The mesh structure is not particularly limited as long as it has a coarse structure and has air permeability.

In this mesh base material, the warp yarns are constituted by (A) and (B), and the weight ratio of (A) / (B) in the total warp yarns is 40 / 60-6.
It needs to be 0/40. As a specific configuration,
For example, as shown in FIG. 1, in a warp, two (B) composite polypropylene monofilaments are driven into one (A) polypropylene multifilament, and in a weft (B) two composite polypropylene monofilaments are used in a weft. A single monofilament is driven into a mesh substrate. In this configuration, if the driving density in the process is the same and the fineness is the same, (A) /
The weight ratio of (B) is 50/50.

Among the configurations combining (A) and (B), a mesh substrate in which one of the warp or the weft is woven as a polypropylene multifilament and the other is a composite polypropylene monofilament is most preferred. The example shown in FIG. 2 shows a state in which all of the wefts are (A) a polypropylene multifilament and all of the warps are (B) a composite polypropylene monofilament is driven. Naturally, the weight composition of (A) / (B) The filament fineness and the punch density are appropriately set so that the ratio is 40/60 to 60/40.

The polypropylene mesh sheet for construction work preferably has a porosity in the open state of 20-8.
It is 0%, more preferably 30 to 70%, and the mesh size is 12 mm or less according to Japanese Industrial Standard JIS-A8952, and is selected according to the purpose and use as a polypropylene mesh sheet for construction work. The basis weight is preferably 80 to 500 g / m ² , more preferably 100 g / m ² .
４００400 g / m ² .

The mesh base material is subjected to a sealing process to prevent misalignment and improve workability such as cutting. This filling process is performed by applying a heat treatment to the mesh base material 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, a hot air tenter type, and the like. Filling is performed by welding the coated polypropylene low melting point component. FIG. 3 shows an example of a state in which the weft yarn intersection is stopped. The heat treatment at this time is performed at a temperature lower than the melting point of the polypropylene high melting point component.
It is necessary to carry out in a temperature range not lower than the softening point of the polypropylene low melting point component. By doing so, strong adhesion by the polypropylene low melting point component can be achieved without impairing the stretching effect of the polypropylene high melting point component.

The sealed mesh base material is cut into a predetermined size, and is turned into a mesh sheet for construction work by folding the peripheral edge or placing eyelets.
It is desirable to have a performance that passes the flameproof standard specified in IS-A8952.

The polypropylene used in the present invention includes:
Within the scope of the present invention, an antioxidant,
Commonly used additives such as dispersants, lubricants, antistatic agents, pigments, inorganic fillers, inorganic flame retardants, crosslinking agents, foaming agents, nucleating agents and the like may be blended.

[0039]

【Example】

Test method 1. Tensile test: Based on JIS-A8952. 2. Flame retardancy test: Based on JIS-A8952. 3. Light fastness test: weatherometer (xenon lamp)
The residual tensile strength after irradiation for 200 hours and 400 hours was measured.

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. Further, a composite polypropylene monofilament was formed as follows. In the core layer,
Polypropylene (MFR = 3.4 g / 10 min., Density = 0.90 g / cm ³ , Tm = 161.0 ° C.) and bis (2,2,6,6-tetramethyl-4-piperidyl) as a light stabilizer 0.1% by weight of sebacate and 1.6% by weight of cyanine green pigment were blended and used. In the sheath layer, a propylene-ethylene random copolymer (MFR = 7.0 g / 1)
0 min., Density = 0.90 g / cm ³ , Tm = 128.4
C), 7% by weight of a master batch containing a flame retardant, etc., 0.5% by weight of (2′-hydroxy-3′-tert-butyl-5′-methylphenyl) 5-chlorobenzotriazole (trade name: Tinuvin 326) as an ultraviolet absorber, acid As an adsorbent, 1% by weight of hydrotalcite (trade name: DHT-4A) and 1.9% by weight of cyanine green pigment were blended and used. The masterbatch containing a flame retardant etc. is composed of 60% by weight of propylene-ethylene random copolymer, 15% by weight of bisdibromopropyl ether tetrabromosulfone, 15% by weight of decabromodiphenyl oxide and 10% by weight of antimony trioxide as brominated flame retardants. % By weight.

The composite polypropylene monofilament is
A polypropylene high melting point component of the core layer and a polypropylene low melting point component of the sheath layer are extruded from a monofilament molding die in which two layers of discharge holes connected to two extruders are provided concentrically. The film was stretched by a factor of .5 and annealed at a processing temperature of 140 ° C. to form a composite polypropylene monofilament. The resulting composite polypropylene monofilament had a core layer / sheath layer composition ratio of 70/30 and a fineness of 460d.

Using the thus obtained polypropylene multifilament as a weft and a composite polypropylene monofilament as a warp, a plain weave mesh body of 26 lines / inch and 16 lines / inch was woven. The basis weight of the sheet was about 105 g / m ² , and the porosity of the mesh body was 35%. The mesh body was fused at 145 ° C. by a hot air tenter-type heating process at the intersections of the warp yarns to perform a filling process,
The peripheral edge was processed to obtain a 1.8 × 5.1 m polypropylene mesh sheet for construction work.

The obtained mesh sheet had flexibility that can be folded in the vertical direction, and was easy to handle.
The maximum tensile point load of the mesh sheet is 7 in the vertical direction.
0.8kgf / 3cm, lateral direction 68.4kgf / 3cm,
The maximum elongation was 22.6% in the machine direction and 36.5% in the transverse direction. This value passes the JIS-L1091 architectural construction sheet class 2 standard. In the flame retardancy test, the number of times of flame contact was 5 and passed the flame resistance standard of JIS-A8952. Further, the tensile strength after irradiation with the weatherometer for 200 hours and 400 hours was 86.4% and 59.4%, and the weather resistance was good.

Example 2 In forming a composite polypropylene monofilament, the sheath layer was made of syndiotactic polypropylene (syndiotactic pentad fraction =
0.82, MFR = 6.0 g / 10 min., Mw / Mn
= 2.0, Tm = 130 ° C), except that Example 1 was used.

The obtained mesh sheet had flexibility that can be folded in the vertical direction, and was easy to handle.
The maximum tensile point load of the mesh sheet is 7 in the vertical direction.
2.4kgf / 3cm, lateral 66.4kgf / 3cm,
The maximum elongation was 22.8% in the machine direction and 36.5% in the transverse direction. This value passes the JIS-L1091 architectural construction sheet class 2 standard. In the flame retardancy test, the number of times of flame contact was 5 and passed the flame resistance standard of JIS-A8952. Further, the tensile strength after irradiation with the weatherometer for 200 hours and 400 hours was 85.4% and 58.7%, and the weather resistance was good.

[0046]

As described above, the polypropylene mesh sheet for construction according to the present invention comprises a combination of a polypropylene multifilament and a composite polypropylene monofilament, and uses a specific polypropylene low melting point component in the sheath layer of the composite polypropylene monofilament. Thereby, it is possible to obtain a polypropylene mesh sheet for building work which has flexibility, can impart high strength by a stretching effect, and has improved fillability. The polypropylene constituting the main component of the polypropylene mesh sheet for building construction of the present invention has a low thermal conductivity, the propagation speed of the flame is low, the combustion proceeds locally, the decomposition of the polypropylene occurs, and the fluidity increases. It is considered that the combustibles are dispersed, and even if a relatively small amount of a flame retardant is blended, the mesh sheet for building work can pass the flameproof standard. As a result, it is possible to obtain a composite polypropylene monofilament without lowering the mechanical properties of the monofilament due to the incorporation of a large amount of flame retardant, and since the sheath layer is composed of a polypropylene low melting point component, By welding the intersections of the warp yarns at a low temperature without reducing the stretching effect of the polypropylene high melting point component of the layer, the mesh sheet can be prevented from misalignment, and the sheet can be easily repaired by welding. Furthermore, it has better cold resistance and antifouling property than the conventionally used vinyl chloride resin coated type.

[Brief description of the drawings]

FIG. 1 is a plan view showing an embodiment of a weaving and knitting structure in a mesh sheet of the present invention.

FIG. 2 is a plan view showing another example of the weaving and knitting structure in the mesh sheet of the present invention, in which the warp is (A) a polypropylene multifilament and the weft is (B) a composite polypropylene monofilament.

FIG. 3 is a partially enlarged view of the mesh sheet of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Mesh sheet 2 Polypropylene multifilament 3 Composite polypropylene monofilament 4 Core layer 5 Sheath layer 6 Warp intersection

Claims (3)

[Claims] 1. A composite polypropylene monofilament composed of (A) a polypropylene multifilament, (B) a core layer composed of a high melting point component of polypropylene and a sheath layer composed of a low melting point component of polypropylene containing a flame retardant, and is either warp or weft. A mesh sheet woven by using a crab, wherein the weight ratio of (A) / (B) in the total warp is 40/60 to 60/40, and the intersection of the warp of the mesh sheet is polypropylene low melting point. A polypropylene mesh sheet for construction work, which is welded and filled with components. 2. The polypropylene mesh sheet for building works according to claim 1, wherein one of the warp and the weft is (A) a polypropylene multifilament and the other is (B) a composite polypropylene monofilament. (B) a core layer comprising a polypropylene high melting point component containing a light stabilizer and a sheath layer comprising a polypropylene low melting point component containing a flame retardant, an ultraviolet absorber and an acid adsorbent. 3. The polypropylene mesh sheet for construction according to claim 1, comprising: