JPH0425990B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention relates to a coating agent for sheet pile joints. More specifically, the present invention relates to a coating agent that is applied to joints (claws) of steel sheet piles and cured with moisture to provide excellent water swelling and water stopping properties. [Prior Art] Conventionally, water-swellable paint compositions and water-low foaming paint compositions using resins with good water permeability (butyral resin, etc.) have been proposed as coating materials for sheet pile joints. Publication No. 47-43612, Special Publication No. 1971
−11807 etc.). However, although these coating agents have swelling properties in fresh water, the swelling rate decreases significantly in seawater or water containing metal ions such as iron and calcium, so that they are not completely watertight. In addition, as a caulking material or water-stopping material, we use a moisture-curable NCO-terminated urethane prepolymer with water-swelling properties, which is a combination of bifunctional and trifunctional polyoxypropylene oxyethylene polyether polyols and polyisocyanates such as tolylene diisocyanate. It is known to be used (Tokuko Sho 53)
-38750). However, in the case of this prepolymer, the swelling rate is small at 0.1 to 4.8 times its own weight, and it has a sufficient water-stopping effect as a coating material for sheet pile joints that requires a large swelling rate (5 to 20 times). I didn't show my true potential. In addition, the base resistance [hydrolysis resistance in aqueous solutions of bases (caustic soda, ammonia, organic amines, etc.)] was poor and it could not withstand use in basic water. [Objects and Structure of the Invention] The present inventors have conducted repeated studies to solve the above-mentioned problems, and as a result, have arrived at the present invention. In other words, the present invention is directed to a urethane bond bonded to an aliphatic group (however, the aliphatic group is bonded to NH of the urethane bond).
A coating material for a moisture-curable sheet pile joint having a water-stopping effect, characterized by containing an NCO-terminated urethane prepolymer A having an NCO group bonded to an aromatic nucleus, and an anti-sagging agent and a solvent if necessary. be. In the present invention, the NCO-terminated urethane prepolymer A includes an NCO-terminated urethane prepolymer of an OH-terminated urethane prepolymer a made of an aliphatic polyisocyanate and an excess polyether polyol and an aromatic polyisocyanate. In the present invention, the aliphatic polyisocyanate that provides the urethane bond bonded to the aliphatic group is a polyisocyanate in which all NCO groups are bonded to non-aromatic hydrocarbon atoms, and for example, the number of carbon atoms (in the NCO group aliphatic polyisocyanates having 2 to 12 carbon atoms, alicyclic polyisocyanates having 4 to 15 carbon atoms, araliphatic (aliphatic having an aromatic nucleus) polyisocyanates having 8 to 12 carbon atoms, and these polyisocyanates. (modified products containing carbodiimide groups, uretdione groups, uretimine groups, urea groups, Biuret groups and/or isocyanurate groups, etc.) can be used. Such polyisocyanates include ethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate (HDI), dodecamethylene diisocyanate, 1,
6,11-undecane triisocyanate, 2,
2,4-trimethylhexane diisocyanate,
Lysine diisocyanate, 2,6-diisocyanate methyl caproate, bis(2-isocyanate ethyl) fumarate, bis(2-isocyanate ethyl) carbonate, 2-isocyanate ethyl-2,6-diisocyanate hexanoate: Isophorone diisocyanate (IPDI) , dicyclohexylmethane diisocyanate (hydrogenated
MDI), cyclohexylene diisocyanate, methylcyclohexylene diisocyanate (hydrogenated
TDI), bis(2-isocyanatoethyl)4-
Cyclohexene-1,2-dicarboxylate:
Examples include xylylene diisocyanate, diethylbenzene diisocyanate: water-modified products of HDI, trimerized products of IPDI, etc., and mixtures of two or more of these. Among these, preferred are HDI,
IPDI and hydrogenated MDI. Examples of polyether polyols include low-molecular polyols (bifunctional polyols such as ethylene glycol, propylene glycol, 1,4-butanediol, diethylene glycol, and cyclohexylene glycol; glycerin, trimethylolpropane, pentaerythritol, sorbitol, and cyclohexose); polyhydric phenols (bisphenols such as bisphenol A, etc.) and/or amines (alkanolamines such as triethanolamine, N-methyldiethanolamine, aliphatic polyamines such as ethylenediamine, diethylenetriamine, aromatic diamines) (for example, tolylene diamine, diphenylmethane diamine, etc.); Random and/or block)] adducts, ring-opening polymers of alkylene oxides (ring-opening polymerization of tetrahydrofuran, hydrolysis to polytetramethylene ether glycol, etc.), and the like. The average hydroxyl equivalent of the polyether polyol is usually 800 to 4,000, preferably 1,000 to 3,000. If the average hydroxyl equivalent is less than 800, the swelling rate will be insufficient;
If it exceeds this, shape retention and pressure resistance when swollen by water will decrease, both of which will cause water leakage. Among the polyether polyols, preferred are ethylene oxide adducts (polyoxyethylene polyols) of di-trihydric alcohols (especially ethylene glycol, propylene glycol and glycerin) and/or adducts of ethylene oxide and propylene oxide (random and/or
or block adduct), [oxyethylene/oxypropylene copolymer polyether polyol (copolymer polyether polyol)], and particularly preferred is copolymer polyether polyol. In the polyether polyol, the oxyethylene content is preferably 50 to 100%, particularly preferably 60 to 85%, based on the total weight of all oxyalkylenes.
It is. If the oxyethylene content is less than 50%, the water swelling rate will be insufficient and cause water leakage. In addition to polyoxyethylene polyols and/or copolymerized polyether polyols, other polyether polyols such as polyoxypropylene polyols can also be used together with these polyether polyols, but in this case, the oxyethylene content in the combined product is Similarly to the above, it is preferably 50 to 100%, particularly 65 to 85% of the total weight of all oxyalkylenes. In the OH-terminated urethane prepolymer a made from aliphatic polyisocyanate and excess polyether polyol, the NCO/OH ratio of aliphatic polyisocyanate and polyether polyol is usually 1/1.2 to 1/8, preferably 1 /1.5 to 1/4. When the NCO/OH ratio exceeds 1/1.2, the OH-terminated urethane prepolymer becomes highly viscous, making it difficult to handle in practice. Also, the NCO/OH ratio is 1/
When it is less than 8, base resistance decreases. The OH-terminated urethane prepolymer a can be obtained by reacting an aliphatic polyisocyanate and a polyether polyol at the above NCO/OH ratio in a conventional manner. The reaction temperature is usually
The temperature is 60 to 130°C, preferably 70 to 120°C, and the reaction time is usually 4 to 20 hours, preferably 6 to 15 hours. The prepolymerization reaction can optionally be carried out in a solvent. Examples of this solvent include polar solvents that do not have active hydrogen, such as ketone solvents (methyl ethyl ketone, methyl isobutyl ketone, etc.), etherified or esterified cellosolve solvents (dimethyl cellosolve, methyl cellosolve acetate, etc.), and two or more of these solvents. A mixture of The weight of the solvent used is usually 0 to 100 parts by weight of the OH-terminated urethane prepolymer.
-120 parts by weight, preferably 10-80 parts by weight. Further, the prepolymerization reaction can also be carried out in the presence of a catalyst depending on the case. This catalyst is
Conventionally known catalysts that generally promote the reaction between isocyanate groups and active hydrogen compounds, such as organometallic catalysts (dibutyltin dilaurate, lead octylate, stannath octoate, etc.) and/or tertiary amine compounds (triethylamine, triethylenediamine, etc.) etc. can be used. The average hydroxyl equivalent of the obtained OH-terminated urethane prepolymer a is usually 900 to 25,000, preferably 1,300 to 9,300. In the present invention, the aromatic polyisocyanate that provides the terminal NCO bonded to the aromatic nucleus of the NCO-terminated urethane prepolymer [A] includes tolylene diisocyanate (TDI), 4,4'-diphenylmethane diisocyanate (TDI), crude MDI, denatured
Examples include MDI (for example, MDI modified to contain a carbodiimide group, uretdione group, or uretonimine group (described in Japanese Patent Publication No. 55-27098)) and mixtures of two or more thereof. Among these, preferred are TDI and
It is MDI. OH-terminated urethane prepolymer in the present invention
In the NCO-terminated urethane prepolymer [A] of (a) and aromatic polyisocyanate, the NCO/OH ratio of the OH-terminated urethane prepolymer (a) and aromatic polyisocyanate is usually 1.4/1 to 3/1, preferably 1.6 /1 to 2.5/1. NCO/OH ratio
If it is less than 1.4/1, the shape retention and pressure resistance during swelling with water will be reduced, and if it exceeds 3/1, the swelling ratio will be insufficient, and both will cause water leakage. The NCO-terminated urethane prepolymer (A) can be obtained by reacting the OH-terminated urethane prepolymer (a) with an aromatic polyisocyanate at the above NCO/OH ratio. The reaction temperature is usually 60~
100°C, preferably 70-90°C, reaction time usually 4-90°C
12 hours, preferably 6 to 10 hours. The reaction to obtain this NCO-terminated urethane prepolymer (A) can optionally be carried out in the presence of a solvent and/or catalyst, as in the case of obtaining the OH-terminated urethane prepolymer (a), and the preferred solvent and its amount are also known. The same amounts and preferred catalysts are also the same. The obtained NCO-end urethane prepolymer (A)
NCO% is usually 0.05-7%, preferably 0.1%-4
%. The molar ratio of aliphatic polyisocyanate to aromatic polyisocyanate in the total polyisocyanate used to obtain the NCO-terminated urethane prepolymer (A) is usually 1:0.7 to 20, preferably 1:0.8.
~9. The concentration of urethane bonds bonded to aliphatic groups in the NCO urethane prepolymer (A) (if a solvent is used, the composition excluding the solvent) is usually 2.5 × 10 ^-5 mol/g
~1.0×10 ^-3 mol/g, preferably 7.0×10 ^-5 mol/
g ~ 6.5×10 ^-4 mol/g, and the concentration of urethane bonded to the aromatic nucleus is usually 5.5×10 ^-5 mol/g ~ 3.0
×10 ^-3 mol/g, preferably 1.5 × 10 ^-4 mol/g ~
It is 2.0×10 ⁻³ mol/g. The OH-terminated urethane prepolymer (a) made from aliphatic polyisocyanate and excess polyether polyol and the NCO-terminated urethane prepolymer (A) made from this and aromatic polyisocyanate are compounds represented by the following general formula. can be given.
(a): R ₁ [-(OCONH-A-NHCOO-R ₁ )- _o OH] ₂
(1) R ₁ ′ [−(OCONH−A−NHCOO−R ₁ )− _o OH] _x
(2) R ₁ ′ [−OCONH−A−NHCOOR ₁ ′(−OH) _x-1 ]
x (3) R ₂ ″(−OCONH−Ar−NCO) _y (3)′ [In the formula, R ₁ is a polyether diol residue, A
is an aliphatic diisocyanate residue, n and m are integers of 0 or 1 or more, and R ₂ , R ₂ ′, and R ₂ ″ are OH-terminated urethanes represented by general formulas (1), (2), and (3), respectively. prepolymer residue, x is an integer of 3 or more (preferably 3
~8 integer), y is an integer represented by x x (x-1). In the present invention, the NCO-terminated urethane prepolymer (A) can be used in combination with another NCO-terminated urethane prepolymer (B) if necessary. (B) is, for example, the NCO described in the specification of Japanese Patent Application No. 58-39088.
Examples include terminal urethane prepolymers. (A) and (B)
Although the proportion of (A) can be varied, it is preferable that (A) be contained in an amount of 20% by weight or more, particularly 50% by weight or more, based on the total amount of the NCO-terminated urethane prepolymer. In addition to the NCO-terminated urethane prepolymer [(A) and, if necessary, (B) used together], the coating material of the present invention can contain an anti-sag agent and a solvent if necessary. Examples of anti-sag agents include finely divided powdered silica, asbestos, and gallus fiber. The weight of the anti-sagging agent used is
The amount is usually 0 to 20 parts by weight, preferably 0.5 to 10 parts by weight, per 100 parts by weight of the NCO-terminated urethane prepolymer. Examples of the solvent include solvents that can be used in the prepolymerization reaction, such as keto solvents, ester solvents, ethers or esterified cellosolve solvents, and mixtures of two or more thereof. The weight of the solvent is usually 0 to 120 parts by weight, based on 100 parts by weight of the NCO-terminated urethane prepolymer, as in the prepolymerization reaction.
Preferably it is 10 to 80 parts by weight. The coating material of the present invention further includes other compounding agents,
For example, fillers, colorants, antioxidants, plasticizers, etc. can be included. Fillers include bentonite, calcium carbonate, clay, and talc; colorants include titanium white,
Antioxidants such as carbon black, red iron and chrome green; hindered phenols and hindered amines; plasticizers such as
Examples include dioctyl phthalate, dibutyl phthalate, and dioctyl adipate. The total weight of other compounding agents is usually 0 to 50 parts by weight based on 100 parts by weight of the NCO-terminated urethane prepolymer.
Preferably it is 0 to 30 parts by weight. When applying the coating material of the present invention to a sheet pile joint, examples of the application method include spray coating, brush coating, spatula coating, and coating with a caulking gun. And the film thickness is usually 100μ
~2.5mm, preferably 500μ~2mm. film thickness
If it is less than 100μ, it may not be able to fill the gap between the sheet pile claws when water swells, or it may lack pressure resistance, both of which may cause water leakage. Also, increase the film thickness to 2.5
If it is larger than mm, it will be difficult to mutually join the nail parts coated with the present coating material. The amount of coating is usually 50g to 200g, preferably 100g to 150g per meter of sheet pile (one nail). The coating material of the present invention is usually applied to the nail portions of both sheet piles to be joined so that the coated surfaces face each other (in that case, the film thickness and coating amount are as described above), The coating may be applied only to one of the claws to be joined, and in this case, the film thickness is usually 200 μm to 5 mm, preferably 1 mm to 4 mm. The amount of coating is usually 120 to 400 g, preferably 200 to 300 g per meter of sheet pile. The coating material of the present invention needs to be cured with moisture in the air after being applied to the sheet pile, and thereby exhibits excellent water swelling properties. Shape retention and pressure resistance cannot be obtained. Curing conditions for moisture curing can be varied, but are usually at room temperature for 5 hours to 2 days. The sheet pile coated with the coating material of the present invention is immersed in water after the coating material is cured, and the time from curing to immersion in water is not particularly limited. The sheet piles with a moisture-cured coating layer are then driven into the ground using water (fresh water, seawater, hard water, water containing metal ions, etc.) and are immersed in water, which causes the coating layer between the sheet piles to swell. It fills gaps and exhibits a water-stopping effect. The applied and hardened coating material has the property of swelling to about 5 to 20 times its own weight when immersed in water, and has sufficient pressure resistance (for example, 5 kg/cm ² G Water pressure 60 minutes or 3Kg/
cm ² G water pressure (no water leakage after 72 hours). The coating material for sheet pile joints of the present invention exhibits excellent base resistance [hydrolysis resistance in basic (caustic soda, ammonia, organic amines, etc.) aqueous solutions] after application and curing, and even in basic water. Sufficient for use. In addition, the coating material that is applied to the gap between the sheet piles and swells has good weather resistance and does not peel off or fall off when it swells with water. It also has the effect that the water swelling ability, pressure resistance, and water stop property do not decrease even after repeated water swelling and drying. Furthermore, the coating material of the present invention can be used not only for freshwater but also for seawater, hard water, calcium, etc., which have conventionally low water swelling properties.
It has excellent water swelling properties even in water containing metal ions such as iron, and exhibits water swelling properties that are almost equal to or higher than in fresh water.Moreover, in water containing metal ions, the swollen substances are in the gap between the sheet piles and are not as strong as fresh water. Shows pressure resistance equal to or higher than that of . [Example] The present invention will be further described below with reference to Examples and Comparative Examples, but the present invention is not limited thereto. Parts in the examples indicate parts by weight. In addition, the swelling rate in the examples is water absorption amount (g) / weight of coating material for sheet pile joints before dipping (
g) x 100, and the water stop test was conducted as follows. Waterstop test 50g of the coating material of the present invention (approximately 1mm film thickness) was applied with a brush to the claws of each of two 50cm-long U-shaped, linear, and Z-shaped steel sheet piles, and the coating material was applied at room temperature. atmospheric 24
After curing and curing for a period of time, the claw parts coated with the coating material were joined together to prepare a specimen. The specimen was then immersed in seawater for one week. After that, a half-pipe-shaped steel water tank with a pressure relief valve, a pressure gauge, and an inlet pipe from a pressure pump attached to the top was joined. Bolts and nuts were installed so that the claws of the steel sheet piles were on the diameter of the steel water tank. The gap between the steel sheet pile and the steel water tank was filled with putty to create a pressure test device.
Next, open the pressure relief valve of the steel water tank, fill the test equipment with water from the pressure pump, and close the pressure relief valve.
The presence or absence of water leakage was tested by applying pressure using a pressure pump at 5 kg/cm ² G for 60 minutes, and then for 72 hours at 3 kg/cm ² G for those with no water leakage. Examples 1 and 2 1000 parts of polyether glycol (hereinafter referred to as polyether glycol) with an average molecular weight of 4000 obtained by adding a mixture of EO and PO in the weight ratio of EO and PO shown in Table 1 to ethylene glycol (hereinafter referred to as polyether glycol) and IPDI28
(NCO/OH=1/2) was reacted at 120° C. for 8 hours to obtain an OH-terminated urethane prepolymer having an average hydroxyl equivalent of 4110. Additionally, 1028 parts of this OH-terminated urethane prepolymer was added to 75 parts of MDI (NCO/OH ratio).
Add 2.4/1 and react at 80℃ for 5 hours to reduce NCO%
obtained 1.3% urethane prepolymer. 35 parts of ethyl acetate to 60 parts of the above urethane prepolymer
and 5 parts of Aerosil #200 (ultrafine powdered silica, manufactured by Nippon Aerosil) were added and mixed uniformly to obtain a coating material for sheet pile joints of the present invention. 100g of this coating material was applied to both claws, and then cured in the atmosphere at room temperature.U-type, straight-type, and Z-type steel sheet piles each having a length of 50cm to which the coating material was attached were coated with tap water, 3% saline solution, and 1% NaOH
The swelling ratio was measured after being immersed in an aqueous solution for one week. Furthermore, a water stop test was conducted on this coating material, and the results are also shown in Table 1.

【table】

[Table] Examples 3 and 4 Polyether glycol (hereinafter referred to as polyether glycol) having the average molecular weight shown in Table 2 obtained by adding a mixture of EO and PO in an EO/PO weight ratio of 80/20 to ethylene glycol. ) and IPDI
were added in the proportions shown in Table 2 (NCO/OH ratio 1/2) and reacted at 120°C for 8 hours to obtain OH-terminated urethane prepolymers having the hydroxyl group equivalents shown in Table 2. Furthermore, this OH-terminated urethane prepolymer and TDI-80 were added in the ratio shown in Table 2 (NCO/OH ratio 2.4/1) and reacted at 80°C for 8 hours to obtain the NCO% shown in Table 2. A urethane prepolymer was obtained. The NCO-terminated urethane prepolymer thus obtained was used as a coating material for the sheet pile joint of the present invention. 100g of this coating material was applied to both claws, and then cured in the atmosphere at room temperature.U type, straight type, and Z type steel sheet piles each having a length of 50 cm with the coating material adhered were coated with tap water, 3% saline solution, and 1% NaOH
The swelling ratio was measured after being immersed in an aqueous solution for one week. Furthermore, a water stop test was conducted on this coating material, and the results are also shown in Table 2.

【table】

〔Effect of the invention〕

The coating material for the sheet pile joint of this invention is an NCO-terminated urethane prepolymer having a urethane bond bonded to an aliphatic group (however, the aliphatic group is bonded to NH of the urethane bond) and an NCO group bonded to an aromatic nucleus. (A) and an anti-sag agent and a solvent if necessary, so if it is moisture-cured in the atmosphere, it can be cured not only in fresh water but also in seawater or water containing metal ions such as iron and calcium. ,
It exhibits excellent water swelling properties and pressure resistance, and therefore, even if the coating material of the present invention is applied to the joint and the interlocking sheet piles are driven into the bottom ground of any of the water quality mentioned above, the sheet pile joint will remain stable. It is possible to reliably close the gap and make the sheet pile joint completely watertight, and furthermore, since the coating material of the present invention has base resistance, it can be used even in basic water, etc. can get.

Claims (1)

[Claims] 1. An NCO-terminated urethane prepolymer (A) having a urethane bond bonded to an aliphatic group (however, the aliphatic group is bonded to NH of the urethane bond) and an NCO group bonded to an aromatic nucleus; 1. A coating material for a moisture-curable sheet pile joint having a water-stopping effect, which contains an anti-sagging agent and a solvent if necessary. 2. Claim 1, wherein (A) is an OH-terminated urethane prepolymer (a) made of an aliphatic polyisocyanate and an excess of polyether polyol, and an NCO-terminated urethane prepolymer of an aromatic polyisocyanate. Application materials listed. 3 In (a) above, the aliphatic polyisocyanate and the polyether polyol are mixed with an NCO/OH ratio of 1/1.2.
The coating material according to claim 2, wherein the coating material is reacted at a rate of 1/8 to 1/8. 4 The above (A) is an aromatic polyisocyanate and the above
The coating material according to claim 2 or 3, which is obtained by reacting NCO/OH with (a) at a ratio of 1.4/1 to 3/1. 5. The polyether polyol has an oxyethylene content of 50 to 100% based on the weight of total oxyalkylene.
The coating material according to any of item 4. 6 Polyether polyol is oxyethylene/
The coating material according to any one of claims 2 to 5, which is an oxypropylene copolymer polyether polyol. 7 The average hydroxyl equivalent of the polyether polyol is
800 to 4000. The coating material according to any one of claims 2 to 6. 8. The coating material according to any one of claims 1 to 7, wherein the NCO% of (A) is 0.05 to 7%.