JPH10266577A - Polypropylene mesh sheet for construction work - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lightweight polypropylene mesh sheet for construction works, which has high strength and excellent flexibility, crease resistance and folding properties, in which no grain displacement is generated and which has superior flame retardancy and weather resistance. SOLUTION: The mesh sheet is obtained by using a polypropylene multifilament 2 and a polypropylene monofilament 3 as warp and weft and weaving and knitting them. A core-sheath type composite monofilament composed of a core layer consisting of a polypropylene high melting-point component 4 containing a light stabilizer and a sheath layer made up of a polypropylene low melting-point component 5 comprising a flame retarder, an ultraviolet light absorber and an acid adsorbent is used as the polypropylene monofilament 3 at that time, and the intersections of warp and weft are thermally welded and sealed by the polypropylene low melting-point component.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polypropylene mesh sheet for construction work, and more particularly, to a mesh sheet stretched on the outer periphery of a construction work site to prevent danger. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polypropylene mesh sheet for construction work which is excellent, 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. For this purpose, flame retardant standards are specified in Appendix Table 1 of JIS A8952 "Mesh sheets for construction work", and various flame retarding treatments are usually performed to pass the standards. Conventionally, it is known that a mesh sheet made of flammable fibers such as nylon or polyester is coated with a polyvinyl chloride resin to impart flame resistance and at the same time is processed to prevent misalignment. However, the polyvinyl chloride resin has a problem that toxic chlorine gas is generated at the time of combustion, and there are problems such as dirt and smell due to bleeding of the plasticizer. In addition, since mesh sheets for construction work are often used outdoors, they are required to have high weather resistance due to long-term exposure to sunlight.

[0003] Generally, as a method of making a thermoplastic resin flame-retardant, a method of blending a flame retardant with the thermoplastic resin is employed. 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. A multilayer synthetic fiber containing a flame retardant as a component has also been proposed (JP-A-48-91314).

[0005] On the other hand, a mesh sheet using a monofilament as the warp yarn has poor flexibility due to the rigidity of the monofilament, and cannot be folded. Is not good. 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 an additive such as a flame retardant is blended, a trade-off phenomenon such as a decrease in mechanical properties of a formed monofilament also occurs.

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

[0007]

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-wrinkle property, foldability, without misalignment, excellent in flame retardancy and weather resistance. To provide a polypropylene mesh sheet for use.

[0008]

As a technical means for solving the above-mentioned problems, the present invention relates to a mesh sheet in which one of a warp or a weft is a polypropylene multifilament and the other is a polypropylene monofilament, wherein the polypropylene monofilament is a polypropylene sheet. A core-sheath composite monofilament composed of a core layer composed of a high-melting-point component and a sheath layer composed of a polypropylene low-melting-point component containing a flame retardant, wherein the intersection of the warp yarns of the mesh sheet is welded by the polypropylene low-melting-point component. The gist of the invention is a polypropylene mesh sheet for architectural work characterized by being subjected to a stop processing.

The flame retardant is 0.1 to 1% by weight based on the total weight of the mesh sheet, and the polypropylene monofilament comprises a core layer comprising a high melting point polypropylene containing a light stabilizer and a flame retardant, It is a core-sheath type composite monofilament composed of a sheath layer composed of a polypropylene low-melting component containing an ultraviolet absorber and an acid adsorbent.

[0010] The polypropylene mesh sheet for architectural work thus constructed can obtain a flexible mesh sheet by using a combination of a polypropylene multifilament and a polypropylene monofilament as warp yarns, and can form a core layer of the polypropylene monofilament. Since only a light stabilizer is blended in the high melting point component to be formed, a sufficient stretching effect can be imparted, and the sheath effect is not reduced without reducing the stretching effect imparted to the core layer in the filling process. A polypropylene mesh sheet for construction work having high strength and flexibility can be obtained by welding the polypropylene low melting point component of the layer. In addition, since a relatively small amount of the flame retardant is blended, the mechanical properties of the monofilament do not deteriorate, and since the flame retardant is blended in the sheath layer, the light stabilizer blended in the core layer is used. The acid component generated by the decomposition of the halogen contained in the flame retardant does not have the antagonistic effect of the flame retardant, and the acid component is adsorbed by the acid adsorbent and can prevent the adverse effect on the ultraviolet absorbent. In addition, it is possible to obtain a polypropylene mesh sheet for construction work having excellent weather resistance.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The polypropylene used in the present invention is a known polypropylene copolymer such as a propylene homopolymer, an ethylene-propylene block copolymer or a random copolymer, or a mixture thereof. Among them, a propylene homopolymer is desirable for a multifilament capable of obtaining a high tenacity, and those having an isotactic pentad ratio of 0.95 or more are particularly preferably used.

The method for producing a 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.

The polypropylene monofilament is a core-sheath composite monofilament composed of 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. As the polypropylene high-melting point component, a propylene homopolymer is preferable, and particularly, one having an isotactic pentad ratio of 0.95 or more is suitably used. As the polypropylene low melting point component, an ethylene-propylene block copolymer or a random copolymer is preferable, and a random copolymer having a particularly low melting point is suitably used. The composition ratio of the core layer (A) to the sheath layer (B) in the composite monofilament is (A) / (B) = 5.
0/50 to 90/10 is preferred, and 60/40 to 80 /
20 is more preferred.

The method for producing the polypropylene monofilament is not particularly limited, and polypropylene is melted and kneaded by an extruder, and the polypropylene is melted and kneaded from a center discharge hole of a die having two concentric circular discharge holes. The composite monofilament is obtained by supplying a core layer composed of a component, extruding and covering a sheath layer composed of a polypropylene low melting point component on the outer surface thereof, and performing a stretching treatment or the like.
Stretching is performed at a temperature of 90 to 140 ° C., which is lower than or equal to 5 ° C. lower than the melting point of the high melting point component. Next, an annealing treatment is performed at 100 to 150 ° C. The stretching ratio is preferably 5
It is 15 times, more preferably 8 to 12 times.

The fineness of the formed monofilament is 30
0 to 1000d is preferable, and 400 to 700d is more preferable. If the fineness is less than 300d, the strength is inferior and 1000
If it exceeds d, the flexibility is undesirably reduced. The tensile strength of the filament is preferably 5 g / d or more, more preferably 6 g / d or more. Further, the tensile elongation is preferably at least 20%, more preferably at least 25%. 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.

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 excellent in workability at high temperatures and flame retardant effects, 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 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 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 1: 3 to
3: 1 is preferable, and 1: 1 to 3: 1 is more preferable. It is preferable that the bromine-based flame retardant and the flame retardant auxiliary be blended in a proportion of 0.1 to 1% by weight based on the total weight of the mesh sheet. 0.1% by weight
If it is less than 10%, the flame retardancy is insufficient, and if it exceeds 1% by weight, the effect of the flame retardancy is not further improved and it is not economical. As a specific compounding method, it is preferable that the amount of the low melting point component is 0.1.
The content may be 5 to 5% by weight, more preferably 1 to 3% by weight.

The hindered amine light stabilizer used in the present invention includes bis (2,2,6,6-tetramethyl-4-).
Piperidyl) sebacate, 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
Polycondensation product of 1-butanetetracarboxylate, 1- (2-hydroxyethyl) -2,2,6,6-tetramethyl-4-piperidinol and diethyl succinate, 1,6-bis (2,2,
And polycondensates of 6,6-tetramethyl-4-piperidylamino) hexane and 2,4-dichloro-6-tert-octylamino-s-triazine. The compounding ratio of the light stabilizer is preferably from 0.1 to 5% by weight, more preferably from 0.5 to 2% by weight, based on the high melting point component.

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 compounding ratio of the ultraviolet absorber is preferably 0.1 to the low melting point component.
It is 1 to 5% by weight, more preferably 0.5 to 2% by weight.

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 the acid adsorbent is preferably 0.1 to 5% by weight, more preferably 0.5 to 2% by weight, based on the low melting point 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 can be either a method of melting and mixing in an extruder or a method of dry blending with a master batch. May be.

The composite monofilament formed by the above method is woven and knitted by a conventional loom or knitting machine to form a mesh sheet. The texture is not particularly limited as long as it has a coarse texture and has air permeability.
As a polypropylene mesh sheet for construction work, the porosity showing the open state is preferably 20 to 80%, more preferably 30 to 70%.
In 8952, the mesh size is 12 mm or less, and is selected according to the purpose and application as a polypropylene mesh sheet for building construction. The basis weight is preferably 80 to 5
00 g / m2, more preferably 100 to 300 g / m2
It is.

In the present invention, the filling process means that a heat treatment is applied 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, and a hot air tenter type. The filling process is performed by welding the low-melting-point component of the polypropylene coated on the surface layer at the intersection of the warp yarns. The heat treatment is performed in a temperature range below the melting point of the polypropylene high melting point component and above the softening point of the polypropylene low melting point component, but it is important that the polypropylene low melting point component be welded without impairing the stretching effect of the polypropylene high melting point component. It is. This mesh sheet is cut into a predetermined size, and is turned into a polypropylene mesh sheet for building work according to the present invention by, for example, folding the peripheral edge or placing eyelets.

The polypropylene mesh sheet for building work thus obtained preferably has a performance that meets the flameproofing standard specified in JIS A8952.

The polypropylene used in the present invention includes:
Within the scope of the present invention, an antioxidant,
Commonly used additives such as a dispersant, a lubricant, an antistatic agent, a pigment, an inorganic filler, an inorganic flame retardant, a crosslinking agent, a foaming agent, and a nucleating agent may be blended.

[0027]

【Example】

Test method 1. Tensile test: JIS 8952 compliant 2. Flame retardancy test: JIS 8952 compliant 3. Light fastness test: Weatherometer (xenon lamp)
The residual tensile strength after irradiation for 200 hours and 400 hours was measured.

Example 1 Using polypropylene (MFR = 20 g / 10 min., Density = 0.90 g / cm 3, Tm = 158.0 ° C.)
A multifilament having a total fineness of 680d / 120f was formed. Next, a polypropylene monofilament was formed as follows. For the core layer, polypropylene (MFR
= 3.4 g / 10 min., Density = 0.90 g / cm3,
Tm = 161.0 ° C.) and bis (2,2,2) as a light stabilizer
6,6-tetramethyl-4-piperidyl) sebacate 0.1
% By weight and 1.6% by weight of a cyanine green pigment. 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.), 7% by weight of a master batch containing a flame retardant and the like, and (2′-hydroxy-3′-tert-butyl-5′-methylphenyl) 5-chlorobenzotriazole (trade name) as an ultraviolet absorber 0.5% by weight of tinuvin 326), 1% by weight of hydrotalcite (trade name: DHT-4A) as an acid adsorbent, and 1.9% by weight of cyanine green pigment. 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 tetrabromosulfone, 15% by weight of decabromodiphenyl oxide, and 10% by weight of antimony trioxide as brominated flame retardants. % By weight. The composite monofilament is formed by extruding the polypropylene of the core layer and the propylene-ethylene copolymer of the sheath layer from a monofilament forming die in which two layers of discharge holes connected to two extruders are provided concentrically, and a stretching temperature of 100 ° C. The film was stretched at a stretching ratio of 9 and annealed at a processing temperature of 140 ° C. to form a composite monofilament. The fineness of the obtained composite monofilament is such that the core layer / sheath layer is 280 d / 180.
d, the total fineness was 460d. Using the multifilament thus obtained as the weft and the composite monofilament as the warp, a plain weave mesh sheet having a length of 26 / inch and a width of 16 / inch was woven. The basis weight of the sheet was about 103 g / m2, and the porosity of the mesh sheet was 35%. The mesh sheet is fused at 155 ° C. by a hot air tenter type heating process at 155 ° C. to perform a sealing process, and a peripheral edge is processed to obtain a 1.8 × 5.1 m polypropylene mesh sheet for construction work. Was. The obtained mesh sheet had flexibility capable of being folded in the longitudinal direction, and was easy to handle. The maximum tensile point load of the mesh sheet is 69.3 kgf / 3 cm in the vertical direction and 64.5 kg in the horizontal direction.
kgf / 3 cm, the maximum elongation was 21.2% in the vertical direction and 35.3% in the horizontal direction. This value satisfies the JIS L1091 construction work sheet class 2 standard. In the flame-retardant test, the number of times of flame contact was 5 and passed the flame-proof standard of JISA8952. In addition, weatherometer 200
Time, the residual tensile strength after irradiation for 400 hours is 84.3%,
The weather resistance was good at 57.9%.

[0029]

As described above, the polypropylene mesh sheet for construction according to the present invention is a high strength, flexible, and foldable mesh sheet comprising a combination of polypropylene multifilament and polypropylene monofilament. . The above polypropylene monofilament has a high strength because the core layer is a polypropylene high melting point component containing a light stabilizer and does not contain a compounding agent such as a flame retardant, so that it can exhibit a sufficient stretching effect, and has a sheath layer. Flame retardant is imparted by blending a flame retardant, an ultraviolet absorber and an acid adsorbent with the flame retardant, and hydrogen bromide generated by the decomposition of the flame retardant by the action of the acid adsorbent blended in the sheath layer It absorbs an acid component and maintains excellent weather resistance without causing an antagonistic effect of the acid component with an ultraviolet absorber. Polypropylene containing additives such as the above-mentioned flame retardants has low thermal conductivity, so the propagation speed of the flame is slow, local combustion proceeds, and decomposition of the polypropylene occurs. However, even if a relatively small amount of a flame retardant is blended, it is considered that the flame retardant standard of the mesh sheet for construction work can be passed. As a result, it is possible to obtain a composite monofilament that does not cause a decrease in the mechanical properties of the monofilament due to the incorporation of a large amount of flame retardant, and since the sheath layer is made of a polypropylene low melting point component, By welding the intersections of the warp yarns at a low temperature without lowering the drawing effect of the high melting point component, misalignment of the mesh sheet can be prevented, 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 partially enlarged view of a polypropylene mesh sheet for construction work of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Polypropylene mesh sheet for construction work 2 Polypropylene multifilament 3 Polypropylene monofilament 4 Polypropylene high melting point component 5 Polypropylene low melting point component 6 Filling part

Claims (3)

[Claims] 1. A mesh sheet in which one of a warp or a weft is a polypropylene multifilament and the other is a polypropylene monofilament, wherein the polypropylene monofilament comprises a core layer composed of a polypropylene high melting point component and a sheath composed of a polypropylene low melting point component containing a flame retardant. What is claimed is: 1. A polypropylene mesh sheet for building construction, comprising a core-sheath type composite monofilament composed of layers, wherein a warp yarn intersection of a mesh sheet is welded with a polypropylene low-melting point component and filled. 2. The method according to claim 1, wherein said flame retardant is present in an amount of 0.1 to 1% by weight based on the total weight of the mesh sheet.
Polypropylene mesh sheet for construction work according to 1. 3. A core in which the polypropylene monofilament comprises a core layer composed of a high melting point component of polypropylene containing a light stabilizer and a sheath layer composed of a low melting point component of polypropylene containing a flame retardant, an ultraviolet absorber and an acid adsorbent. 3. The polypropylene mesh sheet for building works according to claim 1, which is a sheath-type composite monofilament.