JP3598003B2 - Wood chip pavement composition - Google Patents

Description

【００１９】
【表２】

【００２０】
【発明の効果】
本発明のウッドチップ舗装材組成物は、（１）少ないバインダー量で接着強度がえられる、（２）ウッドチップ本来の色調を保持した舗装層を与える、（３）収縮率の低い舗装層を与える、（４）強度、弾性、摩耗性、透水性、耐水性に優れた舗装層を与える、（５）固化が早く施工後の解放に至るまでの時間が短い、（６）低コストで施工できる、といった効果面での特長を有している。[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a cold-cured wood chip pavement comprising wood chips and an elastic binder resin.
[0002]
[Prior art]
A method has been developed in which wood chips are mixed with an elastic binder resin, spread over a roadbed, solidified, and used as a park promenade, a jogging road, a golf course path, or the like. Examples of the elastic binder resin include aqueous emulsions of vinyl-based or diene-based synthetic resins, asphalt emulsions (JP-A-2-248505, JP-A-6-17403), and urethane prepolymers (JP-A-3-96503, JP-A-4-347202, JP-A-8-81907) is used.
[0003]
[Problems to be solved by the invention]
However, pavement materials using an aqueous emulsion as a binder not only take a long time to solidify due to solidification due to evaporation of moisture, but also have a problem that the binder efficiency is poor because the binder is absorbed by wood chips. . Further, since the water resistance of the binder is inferior, there is also a problem that whitening occurs when the pavement is flooded, and it is difficult to secure the water resistance of the pavement material. Furthermore, since wood chips themselves can contain a large amount of water, when an aqueous emulsion is used as a binder, a large amount of water is absorbed by the wood chips, and the pavement material shrinks when the water evaporates after paving. In some cases, cracks and warpage may occur in the pavement layer, and the pavement function may be significantly reduced.
On the other hand, a pavement material using a moisture-curable liquid urethane prepolymer as a binder solidifies by reaction with moisture, but the curing speed and physical properties after curing depend on the moisture content in wood chips, construction environment humidity, temperature, etc. There is a problem that it is difficult to secure stable performance. Further, since the liquid urethane prepolymer is absorbed by the wood chips, there is a problem that not only the binder efficiency is reduced but also the woody color of the wood chips is changed.
In addition, when urethane prepolymer is used as a binder, if the wood chips do not contain a significant amount of water, the binder will be absorbed by the wood chips before it solidifies by reacting with water and will work effectively as a binder. For this reason, there is a case where the paving material has to be produced under conditions that are disadvantageous for low shrinkage such as pre-wetting the wood chips with water.
Therefore, the present invention, in the wood chip pavement, to produce a higher bonding effect with a smaller amount of binder, that is, excellent binder efficiency, retain the original color tone of the wood chip, wood chip pavement material with a low shrinkage further. To provide.
[0004]
[Means for Solving the Problems]
In order to solve the above problems, intensive result of extensive research (A) wood chips, (B) a polymer compound aqueous Emarusho comma other and a water-soluble polymer compound aqueous solution (C) terminal isocyanate groups-containing liquid urethane resin Ri Na comprise, by weight of the total amount of water contained in the (a) and (B) for (C) is 100: 25 to 100 der Ru paving material not only the binder efficiency is improved, It has been found that the color tone of the pavement surface can maintain the original color tone of the wood chip, and that if the amount of water contained in the wood chip used is set to a low level, the shrinkage will be small, and further studies have been made according to the present invention. Was completed. That is, the present invention
(1) (A) wood chips, (B) a polymer compound aqueous Emarusho comma others Ri name contains a water-soluble polymer compound solution and (C) a terminal isocyanate group-containing liquid urethane resin, for (C) (A ) and (the weight ratio of total water contained in B) is 100: 25 to 100 der Ru woodchip pavement composition,
(2) The weight ratio of dry solid content of (A) wood chips, (B) aqueous polymer compound emulsion and (C) liquid urethane resin containing terminal isocyanate group is 100: 2 to 40:10 to 80 in the above (1). A) a wood chip pavement composition as described above;
(3) The dry solid content weight ratio of (A) wood chips, (B) aqueous solution of a water-soluble polymer compound and (C) liquid urethane resin containing terminal isocyanate group is 100: 0.5 to 5:10 to 80. The wood chip pavement composition according to the above (1),
(4) The wood chip pavement composition according to the above (1), wherein the liquid urethane resin containing a terminal isocyanate group has an NCO content of 5 to 20% by weight, and (5) a granular rubber, a plastic chip, sand, and stone. A wood chip pavement composition according to the above (1), comprising one or more selected from cement.
It is.
[0005]
The most significant feature of the present invention, aqueous Emarusho comma other as the binder component (B) polymer compound lies in a combination of an aqueous solution-soluble polymer compound and (C) a terminal isocyanate group-containing liquid urethane resin. The urethane resin and the polymer compound aqueous Emarusho comma other by the water-soluble polymer compound aqueous solution is stirred and mixed, both easily dispersed, isocyanate groups contained in the urethane resin among the dispersion is high molecular compound aqueous Emarusho comma others react with water in the water-soluble polymer solution, along with the viscosity of the binder phase is increased, the volume of the binder is increased by carbon dioxide gas byproduct. As a result, the absorption of the binder into the wood chips is suppressed, and at the same time, the bonding interface between the wood chips is increased, so that the wood color of the wood chips is maintained and the binder efficiency is increased. Urethane resin polymer compound aqueous Emarusho comma others only react with water-soluble polymer compound in the aqueous solution, because they can be foamed, without the need for excess water, and managing the moisture content of wood chips contained in the low Otherwise, the shrinkage of the pavement material can be kept small.
[0006]
Wood chips have a low specific gravity and have many capillaries, so that they can easily absorb a binder in a liquid state. When the binder is absorbed by the wood chips, the wood color inherent in the wood chips is lost, and the binder efficiency is significantly reduced. In order to suppress the excessive absorption into the binder of wood chips it is thought that keep high binder viscosity, but reduce the kneading workability and wood chips With high initially viscous binder. However, in the paving material composition of the present invention, since the viscosity increases after kneading, the absorption of the binder into the wood chips can be suppressed without impairing the workability, and the original color tone of wood is maintained. A paved surface is obtained.
Since the shape of the chips used for wood chip pavement consists of crushed wood pieces of about 1 mm to several cm, the pavement layer has many voids, and the purpose of walking feeling and water permeability of the pavement layer It is solidified while leaving the voids. Under these conditions, the bonding between the wood chips is point bonding, so that it is necessary to increase the number of bonding points in order to ensure the strength of the pavement layer.
When aqueous Emarusho comma other polymer compounds in combination of a water-soluble polymeric compound solution and terminal isocyanate group-containing liquid urethane resin according to the present invention, the binder by carbon dioxide gas byproduct by the reaction of the urethane resin and water Since the phase foams to increase the volume and increase the bonding area between the wood chips, high strength can be obtained with a small amount of binder. Further, in the paving material composition according to the present invention, the strength is expressed earlier than when the wood chip is solidified with the polymer compound or the polymer compound aqueous solution alone or the urethane resin alone, and the pavement surface can be released earlier. Become.
[0007]
BEST MODE FOR CARRYING OUT THE INVENTION
Next, the wood chip pavement composition of the present invention will be described in more detail.
The wood chip used in the present invention is obtained by chipping an old material such as thinned wood or construction waste material. The size thereof is not particularly limited, but the length is approximately 5 cm or less, the width is 3 cm or less, and the thickness is not limited. Those having a size of 5 mm or less are desirable. The water content of the wood chips may be 5 to 100%, but the larger the water content, the greater the drying shrinkage, which may cause cracks and warpage. Therefore, a water content of 5 to 30% is preferable.
As the polymer compound aqueous emulsion used in the present invention, acrylic resin emulsion, acryl-styrene copolymer emulsion, vinyl acetate emulsion, ethylene-vinyl acetate copolymer emulsion, styrene-butadiene latex, acrylonitrile-butadiene latex, MMA-butadiene latex, And polychloroprene latex. The ionicity of the surfactant used in the latex does not matter. If the solids content of the latex is too high, the kneading properties are poor, and if the solids content is too low, excess moisture results in drying shrinkage. The preferred solid content concentration is 40 to 60%.
[0008]
The aqueous solution of a water-soluble polymer compound used in the present invention includes an aqueous solution of a water-soluble polymer compound such as polyvinyl alcohol, casein, carboxymethyl cellulose, methyl cellulose, polyacrylate, polyethylene oxide, and alginic acid. The concentration of the aqueous solution cannot be unconditionally determined because the water solubility of the water-soluble polymer compound is different, but is preferably as high as possible from the viewpoint of drying shrinkage of the pavement material.
For example, in the case of polyvinyl alcohol, an aqueous solution of about 10% is preferable.
The terminal isocyanate group-containing liquid urethane resin used in the present invention is obtained by reacting a polyisocyanate compound with a polyol (a compound having a molecular weight of 1,000 to 3,000 having two or more active hydrogens) under an isocyanate group (NCO) excess condition. Is a urethane prepolymer that is liquid at room temperature (25 ° C.). As such a polyisocyanate compound, aromatic isocyanates such as toluene diisocyanate, diphenylmethane diisocyanate, and xylylene diisocyanate, or derivatives or adducts thereof can be used. As the polyol, polyester polyols, polyether-based polyols, polycarbonate-based polyols, polybutadiene-based polyols, polyisoprene-based polyols and the like generally used in the polyurethane technical field can be used. It is also a preferred embodiment to use a chain extender together with the polyols during the synthesis of the urethane resin.
[0009]
The NCO content of the isocyanate group-containing liquid urethane resin is 5 to 20%. When the NCO content is 5% or less, a sufficient foaming effect cannot be expected. When the NCO content is 20% or more, foaming increases and the strength as a pavement material is weak. Become.
In the wood chip paving material composition of the present invention, in addition to the essential components of (A), (B) and (C), aggregates such as granular rubber, plastic chips, sand and stone, and cement may be used, if necessary. You can also change the texture and walking feeling of the pavement material by adding other factors. The amount of aggregate and cement to be added in addition to wood chips cannot be specified unconditionally because it differs depending on the size of the aggregate, the type of cement, and the purpose of blending.However, in the case of rubber chips, for example, elasticity without impairing the texture of wood chips In order to impart abrasion resistance, the content is preferably 10 to 50% by weight.
The color tone can be selectively changed by adding a pigment. Furthermore, durability can be improved by adding a weather resistance stabilizer, a preservative, and the like. A solvent can also be added to adjust the viscosity of the terminal isocyanate group-containing liquid urethane resin, the reactivity with water, and the degree of foaming.
The use ratio of the components used in the present invention varies depending on the type of the components. The dry solid content weight ratio of the wood chip: the polymer compound aqueous emulsion: the terminal isocyanate group-containing liquid urethane resin is 100: 2 to 40:10. -80, preferably 100: 5-30: 15-50, and the dry solid content weight ratio of wood chip: water-soluble polymer compound aqueous solution: liquid urethane resin containing terminal isocyanate group is 100: 0.5-5: It is 10-80, preferably 100: 1-3: 15-50.
[0010]
In order to exert the effects of the present invention, in the composition comprising (A), (B) and (C), the amount of water relative to (C) is required and the smaller the amount of water, the lower the shrinkage and water resistance of the pavement material. It is advantageous for sex. Therefore, the weight ratio of the total amount of water contained in (A) and (B) to (C) is 100: 20 to 120, preferably 100: 25 to 100. When the weight ratio of water is more than 120, the solidification property and the water resistance of the cured product become insufficient, and the shrinkage becomes large. On the other hand, if the weight ratio of water is less than 20, a sufficient foaming effect cannot be obtained, and both the color tone and the strength decrease.
In the mixing method of the wood chip pavement material composition of the present invention, a binder resin is added to and mixed with wood chips and kneaded. The order of addition of the binder is not particularly limited, aqueous Emarusho comma others may be added to terminal isocyanate group-containing liquid urethane resin after the addition of water-soluble polymer compound solution, or previously by the addition of the urethane resin aqueous Emarusho comma other from may be added a water-soluble polymer compound solution. Alternatively pre-aqueous Emarusho comma other separately may be added a mixture stirs the water-soluble polymer compound aqueous solution and the urethane resin.
The mixed and stirred wood chip pavement material is spread over the roadbed, spread evenly with a lath, and then rolled with rollers, a rolling machine, a vibratory soil converter, and the like. Further, the wood chip pavement composition mixed and stirred can be molded in a mold and spread over the roadbed.
[0011]
【Example】
Next, the present invention will be described more specifically with reference to Examples and Comparative Examples, but the present invention is not limited thereto.
Example 1
100 parts by weight of dry weight wood chips (construction waste chips having a length and width of 1 to 3 cm, a thickness of 1 to 5 mm, and a water content of 10%) are put into a mixer, and a TDI-based urethane prepolymer (Takenate F) is added thereto. -135, 40 parts by weight of NCO 7%, viscosity 9,000 cps, manufactured by Takeda Pharmaceutical Co., Ltd. were added and mixed, and then a modified acrylic emulsion (Ultrasol A50, manufactured by Ganz Kasei Co., Ltd., solid content concentration 50%, viscosity) 220 cps, pH 7) 40 parts by weight were added and mixed well to obtain a pavement material.
The paving material was packed in a mold and cured at room temperature of 23 ° C. and 65% RH for 7 days to prepare a specimen. The prepared specimens were tested for the following items, and the results are shown in Tables 1 and 2 together with the composition of the paving material.
[0012]
Test item a. After completion of the specific gravity curing, the weight and volume of the test specimen were measured, and the specific gravity was determined by calculation.
b. A specimen having a flexural strength of 4 × 4 × 16 cm was measured for flexural strength by a trisection load according to JISR5201 “Physical Testing Method for Cement”. The tester used was AGS500B manufactured by Shimadzu Corporation (load speed 5 mm / min).
c. The specimen was immersed in water at room temperature for 24 hours, and immediately after being taken out, the flexural strength was measured under the above conditions.
d. Impact Absorbency (1) GB Rebound Test When a golf ball was dropped freely from a height of 100 cm, the height at which it bounced (GB coefficient) was measured.
(2) SB rebound test When a hard ball having a diameter of 1 inch was freely dropped from a height of 100 cm, the height at which it bounced (SB coefficient) was measured.
e. A specimen prepared to have a water permeability of 30 × 60 × 3 cm was used.
The site permeation tester of drainage asphalt pavement of Japan Highway Public Corporation standard was used. The permeation performance of the specimens was compared by measuring the elapsed time until 400 ml of water in the cylinder of the permeability tester was drained.
[0013]
f. Abrasion resistance The abrasion resistance of the specimen surface was evaluated using an athletic tester manufactured by Takeda Pharmaceutical Co., Ltd. The test machine is configured such that a rotating load arm hits the surface of the test piece, and the motion is very similar to a human walking motion.
A jogging shoe manufactured by Mizuno Corporation was used for the shoe sole attached to the tip of the load arm. The load applied to the specimen was set to 60 kg, the rotating arm was operated at 60 revolutions per minute, and the abrasion degree of the specimen after 1,000 times was measured. The degree of abrasion was represented by the amount of silica sand used to fill back the abrasion depressions with No. 6 silica sand.
g. The surface of the pavement material having solidified woody color was observed, and a difference from the original color tone of the used wood chip was determined. A sample which retained the original color tone was evaluated as ○, a sample which changed to a dark color tone due to absorption of a binder or the like was evaluated as ×, and a sample intermediate between the two was evaluated as Δ.
h. The dimensions of a 30 × 60 × 3 cm specimen prepared without any restriction between the mold and the shrinkage ratio were measured after curing for 7 days, and the shrinkage ratio was measured.
Test results The specimen has good strength, shock absorption, water permeability, abrasion, wood color tone retention, shrinkage, and physical properties, and is a pavement material with excellent appearance, walkability, and durability. Was proved.
[0014]
Example 2
Using 100 parts by weight of the same wood chips as used in Example 1, 5010 parts by weight of Ultrasol A, and 55 parts by weight of Takenate F-135, a specimen was prepared in the same manner as in Example 1 and subjected to various tests. Table 1 shows the composition of the paving material, and Table 2 shows the physical properties of the paving material as a result of the test. In Example 2, although the use ratio of the polymer compound aqueous emulsion was reduced and the use ratio of the urethane prepolymer was increased as compared with Example 1, the strength and reduction in shrinkage of the test sample were further improved.
Example 3
100 parts by weight of the same wood chips as used in Example 1, 100 parts by weight of Takenate F-13540 parts and 42 parts by weight of a modified SBR latex (Croslen 2M613, manufactured by Takeda Pharmaceutical Co., Ltd., solid content concentration 48%, viscosity 220 cps, pH 7) Specimens were prepared by the same operation as in Example 1 and various tests were performed. Table 1 shows the composition of the paving material, and Table 2 shows the physical properties of the paving material as a result of the test. In Example 3, although the type of the polymer compound aqueous emulsion used was changed, the physical properties of the test sample were very good.
[0015]
Example 4
Using 100 parts by weight of the same wood chips as used in Example 1, Takenate F-13557 parts by weight, and 30 parts by weight of an aqueous solution of a water-soluble polymer compound (PVA 117 aqueous solution, manufactured by Kuraray Co., Ltd., concentration: 10%) Specimens were prepared in the same manner as in Example 1, and various tests were performed. Table 1 shows the composition of the paving material, and Table 2 shows the physical properties of the paving material as a result of the test. In Example 4, an aqueous solution of a water-soluble polymer compound was used in place of the aqueous emulsion of a polymer compound, and good results were obtained in the same manner as those obtained in each of the above Examples.
Example 5
80 parts by weight of the same wood chips as used in Example 1, 20 parts by weight of tire rubber chips (800H, manufactured by Misawa Toyo Co., Ltd.), and 40 parts by weight of Takenate F-135 and 42 parts by weight of Crosslen 2M-613 as binders. Specimens were prepared in the same manner as in Example 1, and various tests were performed. Table 1 shows the composition of the paving material, and Table 2 shows the physical properties of the paving material as a result of the test. In Example 5, a rubber chip was added to a wood chip, and good results were obtained in the same manner as in each of the above examples.
[0016]
Comparative Example 1
Using 100 parts by weight of the same wood chip as used in Example 1 and 120 parts by weight of Ultrasol A50 as a binder, a specimen was prepared by the same operation as in Example 1, and various tests were performed. Table 1 shows the composition of the paving material, and Table 2 shows the physical properties of the paving material as a result of the test. Comparative Example 1 was an example in which a urethane prepolymer was not used as a binder, but the obtained specimen had strength in a normal state, but had extremely low water resistance, and became turbid when immersed in water. The woody color has also turned dark. Furthermore, the drying shrinkage was also large.
Comparative Example 2
Specimens were prepared by the same operation as in Example 1 using 100 parts by weight of the same wood chips as used in Example 1 and 6060 parts by weight of Takenate F-135 as a binder, and subjected to various tests. Table 1 shows the composition of the paving material, and Table 2 shows the physical properties of the paving material as a result of the test. Comparative Example 2 is an example in which only a urethane prepolymer was used as the binder, but a considerable amount of the binder was absorbed by the wood chips before the pavement material was solidified, and sufficient strength was not obtained even in a normal state. Was. The woody color was also darkened.
[0017]
Comparative Example 3
The wood chips used in Example 1 were humidified to a moisture content of 33%, and provided in the same manner as in Example 1 using 100 parts by weight of dry weight and 60 parts by weight of Takenate F-135 as a binder. Specimens were prepared and various tests were performed. Table 1 shows the composition of the paving material, and Table 2 shows the physical properties of the paving material as a result of the test. Comparative Example 3 is an example in which the water content of wood chips was increased and only urethane prepolymer was used as a binder. The obtained specimens had satisfactory strength, but had a large drying shrinkage. became.
[0018]
[Table 1]

[0019]
[Table 2]

[0020]
【The invention's effect】
The wood chip pavement material composition of the present invention provides (1) a bonding layer with a small amount of binder, (2) a pavement layer that maintains the original color tone of wood chips, and (3) a pavement layer with a low shrinkage. Gives (4) Gives a pavement layer with excellent strength, elasticity, abrasion, water permeability and water resistance. (5) Quickly solidifies and takes less time to release after construction. (6) Construction at low cost It has the advantage of being able to do so.

Claims (5)

(A) wood chips, (B) a polymer compound aqueous Emarusho comma others Ri name contains a water-soluble polymer compound solution and (C) a terminal isocyanate group-containing liquid urethane resin, and (A) for (C) ( the weight ratio of the total amount of water contained in B) is 100: 25 to 100 der Ru woodchip pavement composition. 2. The wood according to claim 1, wherein the dry solid content weight ratio of (A) a wood chip, (B) a polymer compound aqueous emulsion, and (C) a liquid urethane resin containing an isocyanate group at a terminal is 100: 2 to 40:10 to 80. 3. Chip pavement composition. The dry solid content weight ratio of (A) a wood chip, (B) an aqueous solution of a water-soluble polymer compound and (C) a liquid urethane resin having a terminal isocyanate group is from 100: 0.5 to 5:10 to 80. The wood chip pavement composition according to any one of the preceding claims. The wood chip pavement composition according to claim 1, wherein the liquid urethane resin having a terminal isocyanate group has an NCO content of 5 to 20% by weight. The wood chip pavement composition according to claim 1, further comprising one or more selected from granular rubber, plastic chips, sand, stone, and cement.