JP2004183417A - Net for construction work - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a low-cost net for construction work having a mesh easily homogenized into soil, high in physical strength and producing no noxious gas when burned. <P>SOLUTION: A main part of this net for construction work is formed of a paper string made of base paper containing conifer kraft pulp as a main raw material. The basis weight is 20 to 80 g/m<SP>2</SP>, and the base paper is made by a cylinder paper machine to obtain the base paper with an aspect ratio of tensile strength of JIS P 8113 being 5 to 15. Further, a wet paper strength increasing agent can be included. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a net for construction work in which a paper cord is knitted. The building construction net according to the present invention includes a low-rise house net and a high-rise house net.
In the present invention, the low-rise residential net is mainly provided on the outer surface of a temporary structure such as a scaffold at a construction work site of a low-rise residence, and includes humans, dust, dust, or small construction or construction members. Are used to prevent the work side from falling or scattering beyond the surface of the scaffold, and include a net for preventing scattering. The low-rise house refers to a building provided to a house such as a wooden structure and a lightweight steel frame having a height of less than 10 m.
On the other hand, the high-rise building net is a high-rise building net having a reinforcing steel bar or a steel frame structure, excluding the low-rise house net, and has the same purpose and function as the low-rise house net.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, a sheet for building works in which a fiber cloth woven from a synthetic fiber such as polyester or polyamide fiber is coated with a vinyl chloride resin is often used. However, sheets processed using this vinyl chloride resin have the problem of generating harmful gases such as dioxin when burned during disposal, and also have the problem of damaging the incinerator because hydrochloric acid is also generated. In addition, there is a problem that, even when discarded in soil, it is difficult to decompose, and the plasticizer contained in the resin leaches out to contaminate the underground.
Recently, biodegradable sheets have been proposed to solve this problem.
Representative examples including biodegradable sheets are described in patent literature.
[0003]
[Patent Document] JP-A-11-182052 JP-A-2000-80799 JP-A-2001-303337 JP-A-2001-303388 JP-A-2001-303391 JP-A-2002-69293 JP-A-2002-2002 No. 275761
If the contents of the above patent gazettes are briefly described,
Japanese Patent Application Laid-Open No. 11-182052 discloses a method in which a mesh portion and a seam allowance that constitute a major part of a mesh sheet are formed only of plant fibers, and are provided on an outer surface of a temporary structure at a building construction site such as a house. Even when incinerated at the time of disposal, there is almost no generation of dioxin, and it is decomposed by bacteria when buried underground.
Japanese Unexamined Patent Publication No. 2000-80799 discloses a mesh sheet for construction work in which the surface of a mesh-like woven or knitted fabric made of polyolefin fibers is coated with an acrylic resin, and has a high strength and generates harmful gas upon combustion. No, it is said that cold resistance and antifouling properties are also good.
JP-A-2001-303387 describes a biodegradable construction work sheet obtained by applying a biodegradable polymer compound to one surface of a woven or knitted fabric of polylactic acid fiber.
Japanese Patent Application Laid-Open No. 2001-303388 describes a biodegradable construction work mesh sheet composed of a woven fabric of polylactic acid fiber, and a part of the polylactic acid fiber is a flame-retardant polylactic acid fiber. .
Japanese Patent Application Laid-Open No. 2001-303391 describes a sheet for building construction in which biodegradable polyester fibers composed of two types of polyester resins having a difference in melting point of 10 ° C. or more are woven.
Japanese Patent Application Laid-Open No. 2002-69293 describes a flame retardant for a mesh sheet for construction work, which comprises a polyurethane resin aqueous dispersion, a non-halogen organic phosphate and an oxazoline group-containing aqueous crosslinking agent.
JP-A-2002-275761 discloses a mesh sheet for building construction in which a mesh sheet using synthetic fiber filament yarn is coated with a water-based acrylic-modified polyester-based polyurethane resin.
[0005]
[Problems to be solved by the invention]
As is clear from the above-mentioned patent publications, those which cannot be biodegraded, woven or knitted polylactic acid fibers or a combination thereof with a biodegradable polymer compound even if biodegradable, or a part of polylactic acid fibers are difficult Only those made of flame-retardant polylactic acid fibers or those made of polyester fibers, etc., at a slightly higher cost are disclosed.
[0006]
[Means for Solving the Problems]
The present invention has been made in view of the above situation, and uses natural fiber, especially softwood kraft pulp as a base material, so that it is easily degraded by bacteria during biodegradation, that is, burying in soil, and By constructing a net formed from knotted nets using a knotted net made from this base paper, a net for construction work having sufficient mechanical strength is provided.
The invention according to claim 1 is a construction construction net characterized by comprising a cord made of base paper mainly made of softwood kraft pulp. The invention of claim ² is the net for construction work according to claim 1, wherein the basis weight of the base paper is 20 to 80 g / m ² , and the invention of claim 3 is that the base paper is a circular net papermaking 3. The net for construction work according to claim 1, wherein the net is made by a papermaking machine. The invention according to claim 4 is measured according to JIS P 8113 of the base paper. An aspect according to any one of claims 1 to 3, wherein the aspect ratio of tensile strength is 5 to 15, wherein the net is Characterized by a knotless network The construction net according to any one of claims 1 to 4, wherein the base paper contains a wet strength agent in the base paper. Item 7. The net for construction work according to any one of Items 5, wherein the wet paper strength enhancer is a polyamide epichlorohydrin resin, an epoxy resin, a melamine resin, a urea resin, a dialdehyde starch, The construction net according to claim 6, wherein the net is at least one selected from polyacrylamide and polyethyleneimine.
[0007]
Hereinafter, the present invention will be described in detail.
The base paper constituting the present invention is mainly made of softwood kraft pulp. The kraft pulp may be bleached kraft pulp (NBKP) or unbleached kraft pulp (NUKP). By adjusting the raw material so that at least 70% of the pulp raw material is softwood, the tension required for the paper string is obtained. Strength can be maintained.
As other pulp to be mixed with softwood kraft pulp, wood pulp such as hardwood pulp, non-wood pulp such as sisal pulp, flax pulp, kenaf pulp, etc., and waste paper pulp to the extent that the strength of paper is not impaired You can do things.
These pulp are supplied to raw materials for base paper through beating treatment by a beating machine such as a beater.
[0008]
The degree of beating treatment is set according to the specific application when used for a construction net having a mesh manufactured from a twisted paper string, and the beating is advanced when a high strength paper string is to be obtained. There is a need. In this case, increasing the blending ratio of Manila hemp is also effective for obtaining a paper cord having high strength.
Further, the base paper used in the present invention may contain additives such as a wet paper strength enhancer, various fillers, a sizing agent and a retention improver, if necessary.
In particular, the wet paper strength enhancer is effective in preventing paper strength deterioration for a certain period of time when incorporated into a construction net manufactured from the paper cord network of the present invention. In this case, the wet paper strength enhancer is not particularly limited, but at least one selected from polyamide epichlorohydrin resin, epoxy resin, melamine resin, urea resin, dialdehyde starch, polyacrylamide and polyethyleneimine. One type can be suitably applied to the present invention.
As the sizing agent, rosin-based sizing agents such as alkyl ketene dimer and alkenyl succinic anhydride, and various synthetic polymer type surface sizing agents can be used.
Further, the retention aid is added to reduce the loss of pulp and filler in the paper machine and improve the yield of papermaking.For example, organic polymer electrolytes represented by polyacrylamide, and aluminum sulfate are represented. The inorganic salts described above are applicable to the base paper used in the present invention.
[0009]
The production of the base paper constituting the present invention is carried out by making a slurry of a papermaking raw material in which the above-mentioned raw materials are blended in a predetermined ratio by a wet paper machine.
The wet paper machine for making the base paper used in the present invention is not particularly limited, such as a fourdrinier and a circular net paper machine applied to general papermaking techniques, but has a sufficient tensile strength necessary for a paper cord net. It is preferable to use a round paper machine in order to ensure the above. The basis weight of the base paper used in the present invention is preferably ²⁰ to 80 g / m ² , and more preferably 30 to 50 g / m ² . If the basis weight is less than 20 g / m ² , it is easy to cut at the time of twisting paper, and if the basis weight exceeds 80 g / m ² , the rigidity is increased and twisting is difficult.
[0010]
The base paper constituting the present invention may be a single-layer paper made of 100% softwood kraft pulp or a mixed paper of the plural pulp components, or may be a two- or three-layer laminated paper. The base paper of the present invention preferably has an aspect ratio of tensile strength in a normal state according to JIS P8113 of 5 to 15. If the aspect ratio of the tensile strength is less than 5, there is a risk of paper breakage when slitting in a tape form from the raw material of the base paper in the production of paper cord, while if it is larger than 15, the tape may be cut off. It is not preferable because there is a possibility that the slit may be torn in a vertical direction when the slit is formed.
[0011]
The base paper obtained by the above process is slit into a winding having a width of 5 to 50 mm and a winding length of about 500 m, cut into a tape shape, set in a twisting machine and twisted to form a paper string. You. The paper string used in the present invention is preferably used as a single piece from the viewpoint of cost, but may be used by twisting several pieces as necessary. Although the thickness of the paper string is not particularly limited, a diameter of about 1 to 10 mm is preferable from the viewpoint of easy handling.
[0012]
In order to create a biodegradable construction building construction net having a mesh of the present invention using the paper cord obtained in the above process, a knotted net or What is necessary is just to knit a knotless net. For the mesh structure of the net, plain weave, twill weave, mosa weave, rou weave, entangled weave and the like are also used.
The mesh-like structure of the net has a coarse structure, and as a construction work sheet, the porosity indicating the open state is preferably 10 to 60%, and the basis weight of the mesh sheet is preferably 60 to 600 g / m ² .
[0013]
BEST MODE FOR CARRYING OUT THE INVENTION
FIGS. 1 to 7 show examples of a knotless network applicable to the construction net according to the present invention. That is, FIG. 1 has a structure called a penetrating type, in which the yarns of two child yarns cross each other, and extend straightly through the connecting portion with the yarn, and FIG. In this example, the net yarn has a structure extending in a zigzag manner, and FIG. 3 shows a turtle-shape type having two child yarns crossed three to four times. FIG. 4 shows a so-called "lace net", which is a netting made of a so-called "lace net". It is called a binding net (ordinary binding net) and twists the warp yarns and puts the weft yarn between them to form a mesh. FIG. 6 shows a binding yarn called a binding net (improved binding net) and twists the above-mentioned weft yarn. 7 is obtained by simply crossing the yarns with a woven mesh.
[0014]
When flame retardancy is required, besides red phosphorus flame retardant and nitrogen flame retardant, aluminum hydroxide, magnesium hydroxide, silica, calcium hydroxide, etc. were added at the time of papermaking or papermaking, and then laced. By impregnating the film later or when the mesh is formed, flame resistance can be easily imparted.
Further, the nets for construction work of the present invention are all used outdoors and are required to have high weather resistance because they are exposed to sunlight for a long time. Therefore, it is preferable to add an ultraviolet absorber or a light stabilizer described below to the net.
In order to impart the ultraviolet absorber or light stabilizer to the construction net of the present invention, it is necessary to mix the raw material of the base paper constituting the present invention with pulp or apply or impregnate the surface of the base paper after paper making. Alternatively, it may be impregnated after forming into a string after twisting, or impregnated after forming into a net.
[0015]
Specific examples of the ultraviolet absorber include, specifically, 2-ethylhexyl-2-cyano-3,3′-diphenylacrylate, ethyl-2-cyano-3,3′-diphenylacrylate, octyl-2-cyano-3. Cyanoacrylate-based ultraviolet absorbers such as 2,3'-diphenylacrylate; benzophenone-based ultraviolet absorbers such as 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone and 2-hydroxy-4-octoxybenzophenone; Benzotriazole UV absorbers such as (2'-hydroxy-5'-methylphenyl) benzotriazole, 2- (2'-hydroxy-5'-t-octylphenyl) benzotriazole, resorcinol monobenzoate, 2,4- Di-t-butylphenyl-3'-5'-di-t-butyl-4 ' And benzoate-based ultraviolet absorbers such as hydroxybenzoate.
[0016]
As hindered amine light stabilizers, 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-butanetetracarboxylate, 1- (2- (Hydroxyethyl) -2,2,6,6-tetramethyl-4-piperidinol and a polycondensate of diethyl succinate.
[0017]
If the construction net of the present invention is required to have soundproofing properties, it is preferable to mix fine particles of metal or a compound thereof having a specific gravity of 3 or more as a soundproofing agent in the base paper or the cord. Generally, sounds generated from construction sites are often heavy bass sounds, and often cause discomfort to residents near the site. Therefore, the heavy bass can be reduced by using a heavy net that absorbs the heavy noise. As such a metal or a compound thereof, metals such as titanium, iron, copper, zinc, silver, barium, zirconium, manganese, antimony, and tungsten and oxides thereof can be used in the present invention.
[0018]
If the net for construction work thus obtained is buried in the soil, it can be easily disassembled and returned to the soil. When discarded, no harmful gas is generated even if burned, and it is buried in the soil and decomposes after a certain period of time to return to the soil.
[0019]
Hereinafter, the present invention will be described in more detail with reference to examples.
Example 1
An aqueous slurry is prepared by beating domestic unbleached kraft pulp (NUKP) to 60 ° SR, and a wet paper strength enhancer made of polyamide epichlorohydrin resin (trade name “Polyfix 301” manufactured by Showa Polymer Co., Ltd.) ) Was added in an amount of 2% to the aqueous slurry to prepare a papermaking raw material. The raw material was applied to a round paper machine to prepare a base paper having a basis weight of 30 g / m ² .
When the tensile strength of the obtained base paper was measured according to JIS P8113, the longitudinal direction was 8.6 kg / 15 mm, the lateral direction was 1.6 kg / 15 mm, and the longitudinal / lateral ratio was 5.4. .
Next, this base paper was slit into a slender tape having a width of 40 mm using a bobbin winder, and the slit was set in a twisting machine and twisted 28 times / 30 cm to produce a paper cord having a diameter of 3 mm. . The strength of this paper string was 15 kg as measured by JIS Z1518.
This paper cord was supplied to a commercially available knitting machine to produce a biodegradable construction building construction net having a net-like structure shown in FIG. In this case, the stitches can be narrowed to have a structure close to a mesh.
[0020]
Example 2
A base paper was prepared under the same conditions as in Example 1 except that 80% by weight of NUKP and 20% by weight of Manila hemp pulp were mixed and beaten to 60 ° SR to prepare an aqueous slurry.
When the tensile strength of the obtained base paper was measured according to JIS P8113, the longitudinal direction was 11.8 kg / 15 mm, the lateral direction was 2.1 kg / 15 mm, and the longitudinal / lateral ratio was 5.6. .
Using this base paper, a paper cord obtained under the same conditions as in Example 1 is supplied to a commercially available weaving machine, and a biodegradable construction building work having a knotless net made of a woven net shown in FIG. Created a net for In this case, the stitches can be narrowed to have a structure close to a mesh.
[0021]
Example 3
An unbleached kraft pulp (NUKP) made in Japan is beaten to 50 ° SR to prepare an aqueous slurry, and a wet paper strength enhancer made of polyamide epichlorohydrin resin (trade name “Polyfix 301” manufactured by Showa Polymer Co., Ltd.) ) With respect to the aqueous slurry. 5% was added to prepare a raw material for papermaking. The raw material was applied to a round paper machine to prepare a base paper having a basis weight of 41.5 g / m ² .
When the tensile strength of the obtained base paper was measured according to JIS P 8113, the longitudinal direction was 13.1 kg / 15 mm, the lateral direction was 1.9 kg / 15 mm, and the longitudinal / lateral ratio was 6.8. Was.
Using this base paper, under the same conditions as in Example 1, a biodegradable construction / building construction net having the structure of a paper cord network shown in FIG. 1 was prepared. The stitch void may be selected according to the application.
[0022]
Comparative Example 1
A mixture of 60% by weight of unbleached kraft pulp (LUKP) made of foreign hardwood and 40% by weight of unbleached kraft pulp (NUKP) is beaten to 55 ° SR to form an aqueous slurry, and polyamide epichlorohydrin is added thereto. A papermaking raw material was prepared by adding a wet paper strength enhancer made of resin (manufactured by Showa Polymer Co., Ltd., trade name "Polyfix 301") in an amount of 2% based on the aqueous slurry. A base paper having a basis weight of 26.9 g / m ² was prepared by applying to a paper machine.
When the tensile strength of the obtained base paper was measured according to JIS P 8113, the longitudinal direction was 5.1 kg / 15 mm, the lateral direction was 1.7 kg / 15 mm, and the longitudinal / lateral ratio was 3.0. Was.
Next, this base paper was slit into a slender tape having a width of 40 mm by a bobbin winder, and the slit was set in a twisting machine and twisted 28 times / 30 cm to prepare a paper cord having a diameter of 3 mm. However, frequent paper breakage has occurred, and it has been difficult to prepare paper strings and, consequently, to create a biodegradable construction building construction net.
[0023]
When the construction net of the present invention obtained in Examples 1 to 3 and the comparison net were put to practical use as a two-story wooden low-rise residential net, the example was damaged throughout the construction period. Although sufficient strength was confirmed, the net of Comparative Example 1, which did not contain softwood as a main component, was broken due to the fall of a piece of wood, which hindered practical use. In addition, as a result of observing the situation in which the used nets were buried and left in the soil in Examples 1 to 3, it was confirmed that the used nets were dispersed in the soil so that the original shape could not be maintained in several years.
[0024]
【The invention's effect】
As described above, the construction net of the present invention differs from the conventional net in that paper is used as a raw material, so that no harmful substances are generated even when incinerated during disposal. Since it is easily buried in the soil, it is easily decomposed by bacteria, and thus has excellent assimilation into the soil during its disposal. Therefore, there are ecological (ecology) advantages. Further, by adjusting the thickness, physical strength, and knitting interval of the vertical and horizontal strings or the slanted strings constituting the mesh, the gap of the stitch can be freely set. Therefore, for example, when a mesh void having a large porosity is required for construction work or the like, the form of the net may be selected from those described in the first and second embodiments. The present invention can be provided. Also, since the material is made of wood pulp, coloring is free, and because it is made of a special paper cord as shown, it has high strength and can withstand repeated use, A wide range of applications can be provided.
[Brief description of the drawings]
FIG. 1 is a plan view of a penetrating knotless net constituting a net of the present invention. FIG. 2 is a plan view of a staggered knotless net constituting a net of the present invention. FIG. 3 is a constitution of a net of the present invention. FIG. 4 is a plan view of a Russell net constituting the net of the present invention. FIG. 5 is a plan view of an ordinary braided net constituting the net of the present invention. FIG. FIG. 7 is a plan view of a knitted net made of a woven net constituting the net of the present invention.

Claims (7)

An architectural construction net comprising a paper cord made of base paper mainly made of softwood kraft pulp. Building construction net of claim 1, wherein the basis weight of the base paper is 20 to 80 g / m ^2. The construction net according to any one of claims 1 to 2, wherein the base paper is made by a round paper machine. The building construction net according to any one of claims 1 to 3, wherein an aspect ratio of the base paper measured by JIS P 8113 is 5 to 15. The construction net according to any one of claims 1 to 4, wherein the net comprises a knotless net. The building net according to any one of claims 1 to 5, wherein the base paper contains a wet strength agent. 7. The wet paper strength enhancer comprises at least one selected from polyamide epichlorohydrin resin, epoxy resin, melamine resin, urea resin, dialdehyde starch, polyacrylamide and polyethyleneimine. The building construction net described in.

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