JPH09157343A - Polyurethane elastomer for antifreezing of road - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a polyurethane elastomer for antifreezing of a road which has a pot life necessary for application, low viscosity, rapid curability at a low temp. and can retain rubber elasticity even at a low temp. by limiting the equivalent ratio of an isocyanate group to an amino group in a curing agent comprising a main agent and a specified crosslinking agent. SOLUTION: As rapid curable polyurethane elastomer for antifreezing of a road to be applied onto the surface of a paved road comprising an asphalt binder or a concrete binder, a main agent composed mainly of an isocyanate- terminal prepolymer prepd. by reacting tolylene diisocyanate with a polyol is mixed with a curing agent comprising an arom. polyamine crosslinking agent as an indispensable component and, if necessary, a plasticizer, a polyol and a catalyst to prepare a mixture, which is then applied and cured. The atom. polyamide crosslinking agent in the curing agent is composed mainly of diethyltrienediamine, and, in an application site, the main agent and the curing agent are mixed together so that the equivalent ratio of the isocyanate group of the prepolymer in the main agent to the amino group of the arom. polyamine in the curing agent is 0.8 to 2.0, followed by curing.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polyurethane elastic body which is a fast-curing polyurethane elastic body that is cured at room temperature and is suitable for cold regions to prevent road freezing damage.

[0002]

2. Description of the Related Art Asphalt pavement, concrete pavement or semi-flexible pavement forms a smooth surface with asphalt or concrete on the ground surface and is used for roads on which vehicles pass. There are many conventional techniques. If these road surfaces freeze, the braking ability of the vehicle will be significantly reduced, leading to accidents.In cold regions, for example, flush water or spray antifreeze agents to prevent the road surface from freezing. Countermeasures such as heating the road surface by road heating are taken.

Further, a polyurethane elastic body is formed on the surface of the road surface, or a plurality of grooves are provided on the road surface, and the grooves are filled with the polyurethane elastic body, so that the elastic body is deformed when the vehicle is running, and the upper surface of the ice surface is frozen. There have been proposed methods such as crushing. Such polyurethane elastic body for protection against frost damage keeps the workable time (pot life) necessary for the construction because the construction on the road pavement surface is often done in winter and at night. However, it has low viscosity (winter, night construction) and low-temperature fast-curing (cures to the extent that the vehicle can pass the next day (morning)), and the cured elastic body is rubber elastic even at low temperatures. Must not be compromised.

The conventional room temperature curable polyurethane elastic body is
An isocyanate-terminated prepolymer (including a partial prepolymer) obtained by reacting tolylene diisocyanate (hereinafter abbreviated as TID) or 4,4′-diphenylmethane diisocyanate (hereinafter abbreviated as MDI) with a polyol as a main component, and a polyol and Or 4,
4'-methylene-bis (2-chloroaniline) (hereinafter M
A two-component mixed polyurethane elastic body using OCA) as a curing agent was the mainstream.

[0005]

However, any of these conventional polyurethane elastic bodies has a problem in low-temperature fast-curing property, and when the MDI prepolymer is used as a main component, defects in rubber elasticity at low temperatures occur. Occurs. Even if the amount of catalyst such as lead octoate is increased in order to accelerate the low temperature curing property, the heat resistance of the cured product will be impaired if the amount used is too large.Therefore, make the curing property fast enough to be applicable in cold weather. I can't.

In recent years, a highly reactive compound comprising a curing agent containing highly reactive diethyltoluenediamine (hereinafter abbreviated as DETDA) as a main component of an aromatic polyamine crosslinking agent and a main agent containing an MDI-based isocyanate component. Polyurethane elastic bodies such as coating floor materials and waterproof materials are known in which two-component urethane materials are instantaneously mixed by a high-pressure collision mixer, spray-coated, and quickly cured. Since the gelation takes about 10 seconds and is extremely fast, there is a drawback in that the pot life required for construction for the purpose of the present invention cannot be obtained at all. That is, as described above, these conventional room-temperature-curable polyurethane elastic bodies have not been able to sufficiently satisfy various performances required for the freeze-damage preventing elastic body.

[0007] Therefore, the present invention has a required performance such that it has a pot life required for construction, has a low viscosity, is quick-curing at a low temperature, and that the cured product retains rubber elasticity even at a low temperature. It was made for the purpose of providing a polyurethane elastic body for preventing road freezing damage.

[0008]

As a result of various investigations, the present inventors have used highly reactive DETDA as a main component of an isocyanate reaction component, and if necessary, blending a plasticizer, a polyol and a catalyst. The curing agent is mixed with the main component containing TDI prepolymer at a predetermined ratio and applied to the road surface, so that it cures quickly even at low temperatures while maintaining the required pot life, and also cures. The inventors have completed the present invention by finding that a polyurethane elastic body for preventing road freezing damage that does not lose rubber elasticity even at a low temperature can be formed.

That is, the present invention is a polyurethane elastic body for preventing road freezing damage, which is constructed on the surface of a paved road consisting of an asphalt-based binder or a concrete-based binder, the elastic body containing tolylene diisocyanate and a polyol. The main component containing an isocyanate-terminated prepolymer as the main component obtained by the reaction of, and an aromatic polyamine crosslinking agent as an essential component, and a curing agent containing a plasticizer, a polyol, and a catalyst, if necessary, are mixed and applied at room temperature. In the curable rapid-curing polyurethane elastic body, a), the main component of the aromatic polyamine crosslinking agent in the curing agent is diethyltoluenediamine, and b) the main agent and the curing agent are the prepolymers in the main agent. The equivalent ratio of the isocyanate group to the amino group of the aromatic polyamine in the curing agent is 0.8 to 2.0. Were mixed at a construction site, a cold-setting rapid curability road freeze damage preventing polyurethane elastomer, characterized in that occupy the cured construction.

In the present invention, the isocyanate-terminated prepolymer, which is the main component of the main component, is the same as the conventional one in that it is produced by the reaction of an excess of TDI and a polyol. In this case, it is preferable that the amount of TDI remaining in a free state in the obtained isocyanate-terminated prepolymer is as small as possible. For this reason, it is preferable that the reaction is carried out at an NCO group / OH group equivalent ratio of about 2 when the TDI and the polyol are charged, but even if TDI is charged in excess, the reaction is carried out under reduced pressure distillation at the end of the reaction. A prepolymer from which free TDI has been removed by such a method can also be used. As the raw material TDI used for producing the isocyanate-terminated prepolymer, TDI having a 2,4-isomer content of 65 to 100% by weight, which is commercially available, is available.
DI can be used.

The other main raw material used for the production of the isocyanate-terminated prepolymer is oxypropylene polyol or oxyethylene propylene polyol (so-called PPG), polyoxytetramethylene glycol, polycaprolactone polyol, polyester polyol, polybutadiene polyol. A polyol generally known as a normal urethane raw material such as castor oil can be used. Among these general polyols, PPG is preferably used in the field of the present invention in view of viscosity or crystallinity at low temperature.

Isocyanate-terminated prepolymer NCO
The content is preferably 1.5 to 8% by weight. NC
When the O content exceeds 8% by weight, when combined with the curing agent used in the present invention, the rubber elasticity at low temperature of the cured product is impaired, while when the NCO content is less than 1.5% by weight. As a result, the mechanical strength of the polyurethane elastic body for preventing road frost damage becomes unsatisfactory. The most preferred range is 2.0 to 7.0% by weight. In the present invention, DETDA used as a main component of the aromatic polyamine crosslinking agent in the curing agent is 3,5-diethyltoluene-
2,4 or 2,6-diamines having different isomer contents are commercially available. Examples of commercially available products include "Etakiure 100" (trade name, manufactured by Ethyl Corporation). Weight ratio of 2,4-isomer / 2,6-isomer 80 /
20) etc. can be used.

Plasticizers optionally used in the present invention include dibutyl phthalate, diheptyl phthalate, dioctyl phthalate, butylbenzyl phthalate, dioctyl adipate, chlorinated paraffin, tris-β-chloropropyl phosphate and the like. Ordinary plasticizers that are not reactive with the NCO groups of the isocyanate-terminated prepolymer in the base compound can be used. The amount of the plasticizer used in the curing agent is 80 with respect to 100 parts by weight of the isocyanate-terminated prepolymer as the main component.
It is desirable to use less than 1 part by weight. If it exceeds 80 parts by weight, the plasticizer tends to bleed out on the surface of the elastic body. Further, when the amount of the plasticizer is large, the asphalt pavement tends to be broken, so that the amount of the plasticizer is preferably 50 parts by weight or less, and particularly preferably 20 parts by weight or less.
Moreover, it is not preferable because it damages asphalt pavement. Most preferably, the amount is 20 parts by weight or less.

As described above, when applying to asphalt pavement, the amount of the plasticizer used is limited, and therefore it is often preferable to use a polyol together. In the present invention, as the polyol to be blended in the curing agent as required, polycaprolactone polyol, polyester polyol,
Ordinary polyols such as polyoxytetramethylene glycol, polybutadiene polyol and castor oil can be used, but polyoxypropylene polyol and polyoxyethylene propylene polyol which are liquid at room temperature and have low viscosity can be preferably used. It is desirable to use the polyol in an amount of 40 mol% or less of the isocyanate reaction component.

In the present invention, since a highly active aromatic amine called DETDA is used as a cross-linking agent, it is often unnecessary to add a curing accelerating catalyst in the construction under ordinary environmental conditions, but it is severe in cold nights during winter nights. Some catalysts can be added under the conditions. Especially when a polyol is used in combination with the curing agent, an organometallic catalyst is required.
An organometallic catalyst such as lead octoate or lead naphthenate is preferably used as the curing acceleration catalyst. Organic acids such as octylic acid and oleic acid can also be used. Ordinary urethane catalysts such as tin catalysts and tertiary amines can be used as long as the amount is small. For example, when lead octoate (lead content 20% by weight) is used, 0.05 to 4 is contained in the curing agent.
By adding the weight%, quick curing can be achieved even at low temperature construction. Further, when the amount of catalyst is in this range, the heat resistance of the cured elastic body does not deteriorate. The curing agent used in the present invention, if necessary, calcium carbonate, talc, kaolin, zeolite, inorganic filler such as diatomaceous earth, chromium oxide, red iron oxide, iron oxide, carbon black, pigments such as titanium oxide, hindered amine type. Stabilizers such as hindered phenols and benzotriazoles can be added.

In carrying out the present invention, a main agent containing an isocyanate-terminated prepolymer as a main component obtained by the reaction of TDI with a polyol, an aromatic polyamine crosslinking agent containing DETDA as a main component, and a plasticizer as required. , A polyol and a curing agent containing a catalyst, a filler, a pigment, a stabilizer, etc., and an equivalent ratio of the NCO group of the prepolymer in the main agent and the NH ₂ group of the aromatic polyamine crosslinking agent in the curing agent is 0. Mix at the construction site to be 8 to 2.0,
It is applied to the target surface and hardened. NC in the main agent
If the equivalent ratio of the O group to the NH ₂ group in the curing agent is less than 0.8, the desired physical properties cannot be obtained, and the yellowing due to the free amine becomes severe, and if it exceeds 2.0, the curability becomes too slow. It does not show fast curing property. The most preferable equivalent ratio of NCO group and NH ₂ group including the physical properties of the elastic body is in the range of 0.8 to 1.7. By mixing the main agent and the curing agent in the predetermined ratio as described above, for example, at a working environment temperature of 5
It is possible to maintain a pot life of 5 minutes or more and 50 minutes or less at ° C. As mentioned above, the conventional urethane elastic body
Although it could not be applied in many cases at low temperatures in the winter, such as 0 ° C. or less, the room temperature-curable polyurethane elastic body according to the present invention was quickly cured even in cold temperatures around −10 ° C. It will be possible. According to the present invention, a cured product of a polyurethane elastic body having a hardness (JIS A hardness) of 40 to 90 even at a low temperature of −10 ° C. and having rubber elasticity is obtained, and this elastic body serves as an elastic body for preventing road freezing damage. It is suitable.

Although the present invention is suitable for manual construction, it can also be applied to mechanical construction using an automatic mixing device such as a static mixer or a dynamic mixer because the pot life and leveling time are long. You can Further, the non-slip aggregate can be blended at the time of mixing the two liquids or can be sprayed on the surface after construction. In order to adjust the viscosity and flowability of the mixed solution, rubber powder, anti-sagging agent, etc. may be added. It is also possible to use a primer to improve the adhesion to asphalt paving material or concrete paving material.

[0018]

The present invention will be further described with reference to Examples and Comparative Examples.

Example 1 13.91 kg of TDI having a weight ratio of 2,4-isomer / 2,6-isomer of 80/20 was charged into a reaction vessel, and polyoxypropylene diol having an average molecular weight of 2000 was 68.87.
kg and 17.22 kg of polyoxypropylene triol having an average molecular weight of 3000 are gradually added, heated to 80 ° C. and heated to 90 to 100 ° C. with stirring, and at this temperature, 6
Hold for time to complete the reaction, NCO group content 3.1% by weight
100 kg of isocyanate-terminated prepolymer (main agent)
Was manufactured. Separately, in a mixing vessel equipped with a dissolver type stirrer, 5.47 kg of DETDA (weight ratio of 2,4-isomer / 2,6-isomer 80/20), 17.33
kg dioctyl phthalate (plasticizer), and 27.2
50 kg of calcium carbonate (inorganic filler) was charged and stirred to produce 50 kg of a curing agent.

After mixing 1 kg of the main agent thus produced with 500 g of the curing agent at 20 ° C. (equal ratio of NCO group of the main agent / NH ₂ group of the curing agent of 1.2), this was divided into 2 minutes and One part is used for viscosity measurement, the other part is a glass plate with a thickness of 1-2 m
It was cast so as to be m, and used as a test piece for measuring basic physical properties and hardness at low temperature. Separately, 500 g of the main agent and 250 g of the curing agent are kept at 5 ° C. and mixed in an atmosphere of 5 ° C., and then cast on a slate plate to have a thickness of 6 mm, and the hardness is measured using a hardness meter. Was tracked and used as a measure of curability at low temperature. As a result, 20
The viscosity immediately after mixing at ℃ was 6000 centipoise, which was a low viscosity. It took 20 minutes to reach 100,000 centipoise. (Pot life) Hardness at 5 ℃ is 4
After the time, the JIS A hardness was 10, showing that it was a low-temperature fast-curing property. After curing at 20 ° C for 7 days, the basic physical properties are hardness (JIS A) 65, tensile strength 85 kgf / c
m ² , breaking elongation 590% and tear strength 28 kgf /
cm and showed good physical properties. When this test piece was allowed to stand at −10 ° C. and its hardness was measured, it had a JIS A hardness of 73.
It was shown that the rubber elasticity is not impaired even at low temperature.

Example 2 As the base polymer prepolymer, the one prepared in Example 1 was used. As in Example 1, 5.3 kg of DETDA (2,4-isomer / 2,2) was placed in a mixing vessel equipped with a dissolver type stirrer.
6-isomer weight ratio 80/20), 11 kg dioctyl phthalate, 22 kg polyoxyethylene propylene triol with an average molecular weight of 5000, 61.5 kg calcium carbonate and 0.2 kg lead octoate (lead content 20% by weight, (Accelerating catalyst) and then stirring to 100
kg of hardener was produced. 1 kg of the main agent of Example 1 and 1 kg of the curing agent produced as described above were mixed at 20 ° C. (equal ratio of NCO group of main agent / NH ₂ group of curing agent of 1.2).
After 4), the sample was divided into 2 parts in the same manner as in Example 1 and used for viscosity measurement basic physical properties and hardness measurement at low temperature. Another 50
Keeping 0 g of the main agent and 500 g of the curing agent respectively at 5 ° C., mixing them in an atmosphere of 5 ° C., casting them on a slate plate so as to have a thickness of 6 mm, and changing the hardness using a hardness meter. Was tracked. As a result, the viscosity immediately after mixing at 20 ° C. was 9000 centipoise, which was a low viscosity. 10
It took 19 minutes to reach 10,000 centipoise. (Casting time) The hardness at 5 ° C. was JIS A hardness of 10 after 5 hours, showing that the hardness was low temperature and fast hardness. 2
After curing at 0 ° C for 7 days, the basic physical properties are hardness (JIS A) 5
0, tensile strength 60 kgf / cm ² , breaking elongation 730%
It also showed good physical properties with a tear strength of 20 kgf / cm. After the test piece was allowed to stand at −10 ° C., the hardness was measured and found to be JIS A hardness of 66, indicating that rubber elasticity was not impaired even at low temperatures. That is, each of the elastic bodies of Examples 1 and 2 is fast-curing at low temperature, and the rubber elasticity is not impaired even at low temperature, and the elastic layer is deformed (deflected) to be applied to the upper layer by being applied to the paved road surface in cold regions. It was able to crush the frozen surface of.

Comparative Example The base polymer prepolymer used was that prepared in Example 1. In the same manner as in Example 1, 7.2 kg of (hereinafter, 4,4′-methylene-bis (2-chloroaniline) (MOCA) was added to a dissolver-type mixing vessel equipped with a stirrer with an average molecular weight of 20.
A solution (15 kg) dissolved in 7.8 kg of polyoxypropylene glycol of 00, 33 kg of dioctyl phthalate, 50 kg of calcium carbonate and 2 kg of lead octoate (lead content 20% by weight) were charged and stirred to give 10
0 kg of hardener was produced. 1 kg of the main ingredient of Example 1,
1 kg of the curing agent produced as described above was mixed at 20 ° C. (NCO group of the main component / equivalent ratio 1.2 of NH ₂ group + OH group of the curing agent) and then the same test as in Example 1. Separately from this, 500 g of the main agent and 500 g of the curing agent are added, respectively.
The mixture was kept at 5 ° C. and mixed in an atmosphere of 5 ° C., then cast on a slate plate to have a thickness of 6 mm, and the change in hardness was traced. As a result, it took 100 minutes to reach 100,000 centipoise at 20 ° C, and the pot life was sufficiently long, but it took 50 minutes to reach JIS A hardness 10 at 5 ° C.
It has been shown to be time consuming and slow to cure at low temperatures, making it unsuitable for use in the present invention.

[0023]

As can be seen from the above description, according to the present invention, a main component containing an isocyanate-terminated prepolymer as a main component, which is obtained by the reaction of TDI and a polyol,
A curing agent containing an aromatic polyamine cross-linking agent containing DETDA as a main component, and NDE groups in the main agent and DETD in the curing agent.
By mixing at the construction site so that the equivalence ratio of A with NH ₂ groups is within the specified range, and coating and curing, the polyurethane elasticity is maintained within a few hours after coating while maintaining the desired pot life. I got a body. This elastic body is fast-curing at low temperature, and its rubber elasticity is not impaired even at low temperatures. When it is applied to the paved road surface in cold regions, the deformation (deflection) of the elastic body causes the upper frost surface to be crushed. Was possible.

Claims (5)

[Claims] 1. A polyurethane elastic body for preventing road freezing damage, which is constructed of an asphalt-based binder or a concrete-based binder on the surface of a paved road, the elastic body being obtained by a reaction between tolylene diisocyanate and a polyol. Room-temperature curing type in which a main agent containing an isocyanate-terminated prepolymer as a main component, an aromatic polyamine crosslinking agent as an essential component, and a curing agent containing a plasticizer, a polyol, and a catalyst, if necessary, are mixed and applied to cure. In the fast-curing polyurethane elastic body, a), the main component of the aromatic polyamine crosslinking agent in the curing agent is diethyltoluenediamine, and b) the main agent and the curing agent are isocyanate groups of a prepolymer in the main agent. At the construction site so that the equivalent ratio of the amino group of the aromatic polyamine in the curing agent to 0.8 to 2.0 Combined, room temperature curing type rapid curability road freeze damage preventing polyurethane elastomer, characterized in that occupy the cured construction. 2. The polyurethane elastic body for preventing road frost damage according to claim 1, wherein the isocyanate group-containing prepolymer has an isocyanate group content of 2.0 to 7.0% by weight. 3. The polyurethane elastic body for road frost damage prevention according to claim 1, wherein polyoxypropylene polyol and / or polyoxyethylene propylene polyol is used as a main raw material of the polyol to be reacted with tolylene diisocyanate. 4. The polyurethane elastic body for road frost damage prevention according to claim 1, wherein the amount of the plasticizer used in the curing agent is 0 to 80 parts by weight with respect to 100 parts by weight of the isocyanate-terminated prepolymer. 5. The polyurethane elastic body for road damage prevention according to claim 1, wherein the polyurethane elastic body has a hardness (JIS A hardness) of 40 to 90 at −10 ° C.