JPH11200178A - Polypropylene meshed sheet for construction work - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a flame retardant meshed sheet excellent in low temperature adhesion, maintaining a high strength without causing a heat deterioration when carrying out processing for fixing the crossing points, good in flexibility and folding properties, and readily treated. SOLUTION: This mesh sheet is woven by carrying out mixed-weaving by using one or both of a polypropylene multifilament X and a sheath and core type conjugated polypropylene monofilament Y as any one or both of the warp and the weft, and the sheath component of the conjugated polypropylene monofilament Y is constituted of a polypropylene-based resin composition comprising following (A) to (C): (A) 50-90 wt.% polypropylene-based resin; (B) 10-50 wt.% flexible propylene-based polymer having <100 deg.C Vicat softening point and (C) 1-20 wt.% flame retardant [with the proviso that the total amount of the components A, B and C is 100 wt.%].

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. And a sheet body 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. Therefore, JIS
Table 1 of the appendix of A8952 “Sheet for construction work” specifies the flameproof standard, and it is customary that various flame retarding treatments are applied so as to pass the standard.

[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.

Accordingly, the applicant has filed Japanese Patent Application No. 9-259829.
No. 2, a multi-filament and a composite polypropylene mono-filament are interwoven to form a mesh sheet. We have proposed a polypropylene mesh sheet. However, when the intersections of the warp yarns are welded and subjected to the sealing process, there is a problem that the strength is reduced due to thermal deterioration, and further improvement has been demanded.

[0006]

SUMMARY OF THE INVENTION In view of the above circumstances, the present invention has excellent low-temperature adhesiveness, retains high strength without causing thermal deterioration during sealing, and has excellent flexibility and foldability. An object of the present invention is to provide a flammable polypropylene mesh sheet for construction work.

[0007]

In view of the above problems, the present invention is a mesh sheet woven and knitted by using a polypropylene multifilament and a core-sheath composite polypropylene monofilament for a warp and / or a weft.
The object of the present invention is to provide a polypropylene mesh sheet for building construction, characterized in that the sheath layer of the composite polypropylene monofilament is made of a polypropylene resin composition containing the following A) to C). A) 50 to 90% by weight of a polypropylene resin B) 10 to 50% by weight of a soft propylene polymer having a Vicat softening point of less than 100 ° C C) 1 to 20% by weight of a flame retardant (however, A) + B) + C) = 100 weight%)

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, polypropylene used for a polypropylene multifilament is
Known polypropylene copolymers such as a propylene homopolymer, a propylene-ethylene block copolymer or a random copolymer or a mixture thereof. Coalescence is desirable, and those having an isotactic pentad ratio of 0.95 or more are particularly preferably employed. This polypropylene melt melt (hereinafter, referred to as
MFR) is preferably 5 to 50 g / 10 min., More preferably 10 to 30 g / 10 min.

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 composed of a core layer made of polypropylene, A) a polypropylene resin, B) a soft propylene polymer having a Vicat softening point of less than 100 ° C., and C) a polypropylene resin composition containing a flame retardant. A core-sheath type composite monofilament composed of a sheath layer made of a material.

As the polypropylene used for the core layer, a propylene homopolymer which has a stretching effect and can be obtained with high strength is preferred, and those having an isotactic pentad ratio of 0.95 or more are particularly preferably used. The MFR of this polypropylene is preferably from 0.1 to 10 g / 10 min., And more preferably from 0.5 to 5 g / 10 min. M
When the FR is less than 0.1 g / 10 min., The difference in fluidity between the sheath layer and the soft propylene polymer becomes large, and the processability of the monofilament deteriorates. Further, the MFR is 10 g / 1.
If it exceeds 0 min., The strength is reduced as a monofilament.

The polypropylene resin of component A) used in the sheath layer is not particularly limited, but preferably has a melting point difference of 10 ° C. or more, more preferably from the polypropylene used in the core layer. Those having a temperature of 20 ° C. or higher are suitably used, and specific examples include a propylene-ethylene block copolymer or a random copolymer, and syndiotactic polypropylene. These polypropylene resins may be used alone or in combination of two or more. Among these, a propylene-ethylene random copolymer is preferred.
The MFR of these polypropylene resins is 1 to 30 g / 1.
0 min. Is preferable, and 5-20 g / 10 min. Is more preferable.

The component (B) has a Vicat softening point of 100 ° C.
Examples of the soft propylene-based polymer of less than a) 10 to 50 parts by weight of a crystalline propylene-based polymer having an isotactic index greater than 80, b) 5 to 20 parts by weight of a xylene-insoluble ethylene-containing copolymer at room temperature Parts and c) 40-80 parts by weight of a copolymer of ethylene and an α-olefin and optionally a small proportion of a diene, said copolymer containing less than 40% by weight of ethylene and being soluble in xylene at room temperature A propylene-based polymer composition, wherein the weight percentage of the sum of the component (b) and the component (c) is 50% to 90% and the weight ratio of (b) / (c) is less than 0.4. Preferably it is.

In the propylene polymer composition, as the crystalline propylene polymer of the component a), a homopolymer of propylene or propylene and an α-olefin other than ethylene or propylene (especially those having 4 to 10 carbon atoms). And a propylene content of 85% by weight or more in monomer conversion. As the α-olefin constituting the copolymer of the component c), those having 4 to 10 carbon atoms as described above are preferable.

The propylene polymer composition is prepared by copolymerizing ethylene, propylene and, if necessary, diene by a multistage polymerization according to the method described in JP-A-6-25367, JP-A-6-25439 and the like. It can be obtained by polymerization.

The other soft propylene-based polymer is obtained by randomly copolymerizing propylene and an α-olefin having 2 to 8 carbon atoms,
A copolymer of 0 to 35 mol% and ethylene of 65 to 80 mol%, or 0.1 to 20 mol% of diene
An ethylene-propylene copolymer rubber which is an ethylene-propylene-diene copolymer containing is preferably used. Ethylene-propylene copolymer rubber has a density of 0.8
It is a low crystalline or non-crystalline polymer at 5 to 0.90 g / cm ³ .

These soft propylene polymers preferably have a Vicat softening point of less than 100 ° C., particularly preferably less than 80 ° C. When the Vicat softening point is 100 ° C. or higher, the low-temperature adhesiveness of the obtained polypropylene mesh sheet for construction work is insufficient, and a sufficient improvement effect cannot be obtained.

As the flame retardant as the component (C), known flame retardants such as halogen-based, phosphorus-based, and inorganic-based flame retardants are used. Halogen-based flame retardants are excellent in workability at high temperatures and flame retardancy, and are inexpensive. 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 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 are 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 polypropylene resin composition used for the sheath layer having the above-mentioned structure has an MFR of 1
３０30 g / 10 min., Preferably 5-20 g / 10 min.
It is better to select from the range of min. MFR is 1g /
If it is less than 10 min., The fluidity becomes poor, and 30 g / 10
If it exceeds min., mechanical properties such as tensile strength are lowered, which is not desirable.

The composition ratio of the core layer / sheath layer in the composite polypropylene monofilament is 50/50 to 90/1.
0 is preferable, and 60/40 to 80/20 is more preferable.

The method for producing the composite polypropylene monofilament is not particularly limited, and the polypropylene forming the core layer and the polypropylene resin composition forming the sheath layer are melt-kneaded by an extruder, and the known two-layer discharge holes are formed. Is a method in which a core layer is supplied from a central discharge hole of a die provided concentrically, a sheath layer is extruded and coated on an outer surface thereof, and a drawing process is performed to obtain a composite polypropylene monofilament. The stretching is performed at a temperature of 90 to 140 ° C. and at a temperature lower by 5 ° C. than the melting point of polypropylene. Then, 100
Annealing treatment is performed at ~ 150 ° C. The stretching ratio is preferably 5 to 15 times, more preferably 8 to 12 times.

The fineness of the formed composite polypropylene monofilament is preferably 300 to 1000 d,
~ 700d is more preferable. If the fineness is less than 300d, the strength is poor, and if it exceeds 1000d, the flexibility is undesirably reduced. The tensile strength of the composite polypropylene monofilament is preferably 5 g / d or more, more preferably 6 g / d or more. Further, the tensile elongation is preferably 20% or more,
5% or more is more preferable. If the tensile strength and tensile elongation are out of the above ranges, the strength as a polypropylene mesh sheet for construction work is insufficient, which is not preferable.

The mesh sheet is formed by weaving and knitting using the polypropylene multifilament (X) and the composite polypropylene monofilament (Y) formed by the above method as the warp and / or weft. That is, (X)
And / or (Y) are interwoven using either or both of the warp and the weft, and specifically, the warp and the weft are (X) and (Y), (X) and (X) + (Y), (X) and (X) + (Y), (X)
+ (Y) and (X) + (Y). FIG. 1 shows an example of (X) and (Y), and FIG. 2 shows another example of (X) + (Y) and (X) + (Y). Here, (X) /
The weight ratio of (Y) is preferably 70/30 to 30 /
70, more preferably 60/40 to 40/60.
If the polypropylene multifilament (X) is less than 30%, the flexibility of the polypropylene mesh sheet for construction work is inferior, and if it exceeds 70%, the flame retardancy and sealing property imparted by the composite polypropylene monofilament (Y) become insufficient. Are not preferred.

The weaving and knitting structure of the mesh body is not particularly limited, and may be any as long as it has coarseness and air permeability. Specifically, examples of the woven fabric include various woven fabrics such as plain weave, woven weave, leno weave, and the like.
Any of vertical knitting may be used, and specific examples include tricot knitting, Miranese knitting, and Russell knitting. And as a mesh sheet for construction work, the porosity indicating the open state is preferably 20 to 80%, more preferably 30 to 70%.
%, And the mesh size is 12 mm or less according to Japanese Industrial Standard JISA8952, and is selected depending on the purpose and application. Further, the basis weight is preferably 80 to 400 g / m.
² , more preferably 100 to 250 g / m ² .

Here, it is preferable that the weft intersections of the mesh body are filled by welding the polypropylene resin composition constituting the sheath layer of the composite polypropylene monofilament. Filling is a hot plate contact type,
Heat treatment is performed on the mesh base material by using a known method such as a hot roll type, an infrared irradiation type, a high frequency welder type, or a hot air tenter type. The heat treatment is performed at a temperature not higher than the melting point of the polypropylene constituting the core layer of the polypropylene multifilament and the composite monofilament, and at a temperature not lower than the softening point of the polypropylene resin composition constituting the sheath layer of the composite monofilament, thereby impairing the stretching effect of the polypropylene. It is important that strong welding be performed without any problems.

This mesh body is cut into a predetermined size,
The polypropylene mesh sheet for building work of the present invention is obtained by, for example, folding the peripheral edge or placing eyelets. The obtained mesh sheet preferably has a performance that meets the flameproof standard specified in JIS A8952.

In the present invention, in combination with the polypropylene multifilament and the composite polypropylene monofilament, a polypropylene flat yarn, a multilayer composite polypropylene flat yarn, a polypropylene split yarn, a multilayer composite polypropylene split yarn, a polypropylene monofilament, a core-sheath composite polypropylene Various filaments such as multifilaments can be used and interwoven without departing from the spirit of the present invention.

The polypropylene and the polypropylene-based resin composition used in the present invention may contain other thermoplastic resins or an antioxidant, an ultraviolet absorber, 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. Vicat softening point: based on JIS K6758 2. Flame retardancy test: based on JIS A8952

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.

Subsequently, a composite polypropylene monofilament was formed as follows. For the core layer, polypropylene (MFR = 3.4 g / 10 min., Density = 0.90 g)
/ Cm ³ , Tm = 161.0 ° C.) A resin composition containing 92% by weight, a master batch containing a flame retardant and the like 7% by weight, and a green pigment 1% by weight was used. A soft propylene polymer for a sheath layer was produced by a two-stage polymerization method of propylene and ethylene. The first stage product of the resulting polymer composition had an ethylene content of 3.0% by weight and a xylene solubles (S _A ) of 9.4% by weight, and the second stage product had a binary copolymer ( b + c) (a total 70% by weight of), xylene solubles (S _F) 63.4 wt%, the component b) 9.45 wt%, was a component c) 60.55 wt%. 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.) 65% by weight
And the soft propylene polymer (MFR = 10 g / 1)
0 min., Density = 0.89 g / cm ³ , Vicat softening point of 68 ° C.) 30% by weight, master batch containing flame retardant etc. 5
(2'-hydroxy-3'-tert-butyl-5'-methylphenyl) 5-chlorobenzotriazole (trade name: Tinuvin 326) as an ultraviolet absorber per 100 parts by weight of the polypropylene resin composition of 0.1% by weight. 5 parts by weight,
Hydrotalcite (trade name: DHT-) as an acid adsorbent
4A) 1 part by weight of cyanine green pigment was mixed and used. The master batch containing a flame retardant etc. is composed of 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 based on 60% by weight of a propylene-ethylene random copolymer. % By weight.

The composite polypropylene monofilament is
A resin composition for a core layer and a sheath layer is extruded from a monofilament molding die in which two layers of discharge holes connected to two extruders are provided concentrically and stretched at a stretching temperature of 130 ° C. and a stretching ratio of 8.5 times. Then, annealing was performed at a processing temperature of 140 ° C. to form a composite polypropylene monofilament.
The fineness of the obtained composite polypropylene monofilament was 320d / 140d for the core layer / sheath layer, and the total fineness was 46%.
0d.

Using the thus obtained polypropylene multifilament as the weft and the composite polypropylene monofilament as the warp, a plain weave mesh sheet of 30 warps / inch and 16 wefts / inch was woven and knitted. The basis weight of the sheet is about 110 g / m ² , and the porosity of the mesh sheet is 3
5%. This mesh sheet was fused at 135 ° C. by a hot air tenter type heating step at the intersection of the warp yarns to provide a sealing process, and the periphery was worked to obtain a 1.8 × 5.1 m polypropylene mesh sheet for construction work. Was.

The stretchability of the composite polypropylene monofilament was good, it was possible to stretch 8.5 times, and high tenacity was obtained. The maximum tensile load of the mesh sheet is 74.
2 kgf / 3 cm, 70.6 kgf / 3 cm in the weft direction, and the maximum elongation was 23.2% in the warp direction and 35.6% in the weft direction. This value is based on the JISL1091 construction work sheet 2.
It passes the class standards. The obtained mesh sheet had flexibility that could be folded in the longitudinal direction, and the handleability was good. In the flame retardancy test, the number of times of flame contact was 5 times,
It has passed the SA8952 flameproof standard. The tensile residual strength after irradiation with the weatherometer for 200 hours and 400 hours was 84.6% and 60.5%, respectively, and the weather resistance was good.

Example 2: In the sheath layer, a propylene-ethylene random copolymer (MFR = 16.5 g / 10 mi) was used.
n., density = 0.90 g / cm ³ , Tm = 128.4 ° C.) 6
5% by weight and ethylene-propylene copolymer rubber (MF
R = 18.0g / 10min., Vicat softening point 60 ° C)
(2'-hydroxy-3'-tert-butyl-5'-methylphenyl) 5-chloro as an ultraviolet absorber with respect to 100 parts by weight of a polypropylene resin composition containing 30% by weight and a master batch containing a flame retardant and the like at 5% by weight. A polypropylene resin composition obtained by blending 0.5 parts by weight of benzotriazole (trade name: Tinuvin 326), 1 part by weight of hydrotalcite (trade name: DHT-4A) as an acid adsorbent, and 1 part by weight of cyanine green pigment. The procedure was performed in the same manner as in Example 1 except that the product was used.

The stretchability of the composite polypropylene monofilament was good, it was possible to stretch 8.5 times, and high tenacity was obtained. The maximum tensile point load of the obtained mesh sheet was 72.2 kgf / 3 cm in the warp direction and 70.6 kgf / 3c in the weft direction.
m, the maximum elongation was 22.3% in the warp direction and 35.6% in the weft direction. This value satisfies the JIS L1091 construction work sheet class 2 standard. The mesh sheet was subjected to a filling process by fusing intersection points of warp yarns at 140 ° C. in a heating process of a hot air tenter type. This mesh sheet had flexibility that can be folded in the longitudinal direction, and was easy to handle. In the flame retardancy test, the number of times of flame contact was 5 times.
It has passed the ISA8952 flame resistance standard. The tensile strength after irradiation with the weatherometer for 200 hours and 400 hours was 83.4% and 59.6%, indicating that the weather resistance was good.

Comparative Example 1 A propylene-ethylene random copolymer (MFR = 16.5 g / 10 m) was used as a sheath layer when forming a composite polypropylene monofilament.
in., density = 0.90 g / cm ³ , Tm = 128.4 ° C.)
Example 1 was repeated except that a resin composition comprising 95% by weight, 4% by weight of the flame retardant used in Example 1 and 1% by weight of a light stabilizer was used. The same filling processing temperature as in Example 1 is 1
45 ° C.

The stretchability of the composite polypropylene monofilament was insufficient, and the draw ratio was limited to 7 times. The maximum tensile point load of the mesh sheet is 60.4kgf /
3cm, weft direction 68.4kgf / 3cm, maximum elongation is
It was 22.8% in the warp direction and 34.5% in the weft direction. Although this value passes the JIS L1091 building construction sheet class 2 standard, it is somewhat insufficient.

[0042]

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 a specific soft propylene polymer is applied to the sheath layer of the composite polypropylene monofilament. By using the contained resin composition, the low-temperature adhesiveness is improved, for example, the bonding start temperature is lowered by 5 to 10 ° C., and good sealing can be performed with good productivity. In addition, it was possible to maintain high strength due to the stretching effect without thermal deterioration at the time of the filling process. 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 one embodiment of a polypropylene mesh sheet for building work of the present invention.

FIG. 2 is a plan view showing another embodiment of the polypropylene mesh sheet for construction work of the present invention.

[Explanation of symbols]

 X Polypropylene multifilament Y Composite polypropylene monofilament

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI D03D 9/00 D03D 9/00 E04G 21/32 E04G 21/32 B

Claims (1)

[Claims] 1. A mesh body woven and knitted by using a polypropylene multifilament and a core-sheath type composite polypropylene monofilament for a warp and / or a weft, wherein the sheath layer of the composite polypropylene monofilament is the following A) to C) A polypropylene mesh sheet for construction work, comprising a polypropylene-based resin composition containing: A) 50 to 90% by weight of a polypropylene resin B) 10 to 50% by weight of a soft propylene polymer having a Vicat softening point of less than 100 ° C C) 1 to 20% by weight of a flame retardant (however, A) + B) + C) = 100 weight%)