JP4198767B2 - Manufacturing method of room temperature curing polyurethane coating material - Google Patents

Description

すなわち実施例２、４および５の結果を勘案すると、本発明の目的を達成するには主剤のＴＤＩプレポリマーのＮＣＯ基と硬化剤中のイソシアネート反応成分のＮＨ2基との当量比には限界的な範囲が存在し、比較例３および４はその範囲外であることを示している。[0001]
[Industrial application fields]
The present invention relates to a method for producing a polyurethane coating material (coating flooring material, waterproofing material) that is applied and cured at room temperature.
[0002]
[Prior art]
Polyurethane-coated floor materials and waterproof materials have been conventionally used in large quantities for applications such as waterproofing of building rooftops, verandas, and corridors, and elastic paving in sports facilities. Such coating floor materials and waterproofing materials are produced by using 4,4′-methylene-bis, which is mainly composed of an isocyanate-terminated prepolymer obtained by a reaction between polypropylene ether polyol and tolylene diisocyanate (hereinafter abbreviated as TDI). -(2-Chloroaniline) [hereinafter abbreviated as MOCA] and polypropylene ether polyol as an isocyanate reaction component, a catalyst such as an organic acid lead salt, or a plasticizer as necessary, is used as a curing agent. after mixing the curing agent at the construction site and, trowel, those of curing by coating with a spatula or lake.
[0003]
In this conventional method, MOCA used as a main component of the isocyanate reaction component in the curing agent has a problem in physiological safety as it is a designated chemical substance, and is solid and highly crystalline at room temperature. Despite being difficult to handle due to poor dissolution stability in plasticizers, etc., the reactivity with isocyanate is relatively moderate, and the pot life required for coating flooring and waterproofing applications (main agent) After mixing with the curing agent, it is possible to apply the coating without any hindrance (normally, the time until the viscosity reaches 100,000 centipoise after mixing), and the coating film properties after curing are also good. So this method occupies the mainstream of this field.
Recently, a fast-curing polyurethane coating material is produced by curing at room temperature using the above-mentioned TDI prepolymer as the main ingredient and physiologically safe diethyltoluenediamine (hereinafter abbreviated as DETDA) as the main component of the curing agent. A method was developed.
[0004]
[Problems to be solved by the invention]
However, since this method uses a highly reactive aromatic polyamine called DETDA as a crosslinking agent, the amount of the plasticizer tends to be increased in order to ensure the pot life, and the surface of the cured coating film has a plasticizer. However, there was a drawback that it was easy to bleed.
[0005]
[Means for Solving the Problems]
As a result of various studies, the inventors have used a reaction mixture of excess DETDA and an isocyanate-terminated prepolymer formed from an organic diisocyanate and a monool or polyol as the main component of the isocyanate reaction component in the curing agent, Using the TDI prepolymer as the main agent , the above-mentioned drawbacks were solved by mixing, coating and curing the two liquids, and the present invention was completed.
[0006]
That is, the present invention is a room temperature curable polyurethane in which a main agent which is an isocyanate-terminated prepolymer obtained by reaction of tolylene diisocyanate and a polyol, and a curing agent containing an isocyanate reaction component and a plasticizer are mixed, coated and cured. the manufacturing method of the coating material, the main component of the isocyanate-reactive component in the curing agent, an organic diisocyanate and monol or the isocyanate-terminated prepolymer obtained by the reaction of Po triol, equivalent weight of amino groups to isocyanate groups the ratio is a reaction mixture obtained by a mixture of diethyl toluene diamine is reacted such that the 3-to-1 or more 30-to-1 ratio less than, and a curing agent described above from the previous noted main agent, Pres in the main agent Isocyanate reaction component amino in polymer isocyanate group and curing agent The equivalent ratio of the mixture at the construction site so that 0.8 to 2.0, a method for producing a cold-setting polyurethane coating material, characterized in that of curing by applying.
[0007]
In the process of the present invention, the isocyanate-terminated prepolymer used as the main agent is produced by the reaction of TDI and a polyol. TDI and polyol are allowed to react with an equivalent ratio of NCO groups / OH groups of usually around 2, but even when excess TDI is used, free TDI is removed by a method such as vacuum distillation after the reaction is completed. Prepolymers can also be used. As a raw material TDI, a commercially available product having a 2,4-isomer content of 65 to 100% by weight can be used, but a prepolymer produced using TDI having a low 2,4-isomer content as a raw material is used. Since the pot life tends to be shortened when used as a main agent, in the field of the present invention, it is desirable to use a TDI containing a high 2,4-isomer content, that is, TDI containing 80% by weight or more.
[0008]
The polyol, which is another raw material used in the production of the TDI prepolymer used as the main agent in the present invention, is a normal urethane such as polypropylene ether polyol, polyethylene-propylene ether polyol, polytetramethylene ether glycol, polycaprolactone polyol, etc. Polyols generally known as raw materials can be used. Among these, in the field of the present invention, it is preferable to use polypropylene ether polyol or polyethylene-propylene ether polyol in terms of viscosity or non-crystallinity at low temperature. The NCO content of the TDI prepolymer is preferably 1 to 7% by weight. If it exceeds 7% by weight, it becomes difficult to ensure the desired pot life when combined with the curing agent used in the present invention. On the other hand, if less than 1% by weight is used, desired physical properties can be obtained as a polyurethane coating material. It becomes impossible.
[0009]
In the method of the present invention, as the main component of the isocyanate reaction component in the curing agent, DETDA and an isocyanate-terminated prepolymer obtained by the reaction of an organic diisocyanate and a monool or polyol are used in an amino group / isocyanate group equivalent ratio. Use a reaction mixture obtained by reacting at a ratio of 3/1 or more.
As the organic diisocyanate used for the production of the isocyanate-terminated prepolymer to be reacted with an excess of DETDA, hexamethylene diisocyanate, isophorone diisocyanate, 4,4′-methylenebis-phenyl isocyanate, TDI, and the like can be used. Most preferable in terms of solubility.
[0010]
The monool or polyol, which is the other raw material used in the production of the isocyanate-terminated prepolymer to be reacted with an excess of DETDA, is obtained by subjecting propylene oxide to addition polymerization using a monoalcohol such as methanol, ethanol or butanol as an initiator. In addition, a low molecular polyol such as polypropylene ether monool having an average molecular weight of 700 to 4000, ethylene glycol, propylene glycol, glycerin, trimethylol propane, or the like as an initiator, and propylene oxide or ethylene oxide added thereto is polymerized with an average molecular weight of 700 to 15000. Polypropylene ether polyol or polyethylene-propylene ether polyol is used.
[0011]
DETDA used in the method of the present invention is 3,5-diethyltoluene-2,4 or 2,6-diamine, and those having different isomer contents are commercially available. As a commercially available product, for example, “Etacure 100” (trade name, manufactured by Ethyl Corporation, weight ratio of 2,4-isomer / 2,6-isomer 80/20) and the like are used.
[0012]
In order to produce a reaction mixture which is a main component of the isocyanate reaction component in the curing agent in the method of the present invention, the equivalent ratio of amino group / NCO group of DETDA and organic diisocyanate prepolymer is 3/1 or more. The mixture is charged at a proper ratio and reacted at 40-50 ° C. for 2-3 hours. If this equivalent ratio is 3/1 or less, the viscosity of the resulting reaction mixture becomes too high and it becomes difficult to handle as a curing agent. If the ratio is 3/1 or more, the upper limit of this ratio is not particularly limited, but if it is about 30/1 or more, DETDA itself is hardly different from the case where DETDA itself is used as the main component of the isocyanate reaction component.
By using such a reaction mixture as the main component of the isocyanate reaction component in the curing agent, the amount of plasticizer used can be reduced while maintaining the required pot life, and thus the plasticizer from the cured coating. It is possible to prevent bleeding.
[0013]
The plasticizer used in addition to the above isocyanate-reactive component to the curing agent in the method of the present invention, dibutyl phthalate, di f heptyl, dioctyl phthalate, butyl benzyl phthalate, dioctyl adipate, chlorinated Ordinary plasticizers such as paraffin, plasticizer resins commonly used for urethane resins such as Eurex and xylene resins, plasticizers that acylate or alkoxideize the hydroxyl group at the terminal of polypropylene ether polyol, or isocyanate terminal A plasticizer in which a prepolymer is sealed with a monofunctional alcohol such as methanol, ethanol, or butanol can be used.
[0014]
It is desirable that the amount of the plasticizer used in the curing agent does not exceed 100 parts by weight with respect to 100 parts by weight of the main component isocyanate-terminated prepolymer. If it exceeds 100 parts by weight, the tendency of the plasticizer to bleed out on the surface of the coating film becomes strong, and the physical properties of the resulting cured coating film also decrease. The polyol used as the isocyanate reaction component in the conventional MOCA-polyol combination curing agent is not an indispensable component and does not need to be blended in the curing agent of the method of the present invention. In order to reduce the amount of ordinary plasticizers that tend to bleed, polyols can be blended in the same way as before, but in this case, it is necessary to add a catalyst in order to complete the reaction with the main agent prepolymer. It shortens usage time. According to the method of the present invention, since the reaction product of polyol is mixed in the curing agent, the addition of a catalyst is unnecessary under normal conditions, and the use of a normal plasticizer is possible without shortening the pot life. The amount can be reduced.
[0015]
In the method of the present invention, an excess of the DETDA reaction mixture is used as the main component of the isocyanate reaction component. Therefore, as described above, the catalyst for accelerating the curing is not essential under normal conditions, but under severe conditions such as low temperatures in winter. In the construction, a small amount of a catalyst such as organic acid lead acid, organic acid such as octylic acid or oleic acid can be added to the curing agent.
Curing agents used in the method of the present invention include inorganic fillers such as calcium carbonate, talc, kaolin, and diatomaceous earth, pigments such as chromium oxide, bengara, iron oxide, carbon black, and titanium oxide as necessary. Stabilizers such as amines, hindered phenols, and benzotriazoles can be blended.
[0016]
To implement the method of the present invention comprises a main agent is an isocyanate-terminated prepolymer obtained by the reaction of TDI with polyols, the reaction mixture with an excess of DETDA and organic diisocyanate prepolymer as the main component of the isocyanate-reactive component, a plasticizer The equivalent ratio of the NCO group of the main agent and the amino group of the isocyanate reaction component in the curing agent is 0. The curing agent obtained by blending an agent and, if necessary, a catalyst, a filler, a pigment, a stabilizer and the like. It mixes at a construction site so that it may become 8-2.0, and it coats and hardens it on a to-be-coated article. If the equivalent ratio between the NCO group of the main agent and the amino group in the curing agent is less than 0.8, the reaction is too fast and it becomes difficult to take the usable time and the yellowing of the coating film becomes severe. The properties become too slow, and the strength of the cured coating film becomes low. The most preferred equivalent ratio of NCO group to amino group including the physical properties of the coating film is 0.9 to 1.5. By mixing the main agent and the curing agent in the above-described ratio, it is possible to maintain a pot life of 20 minutes or more and 150 minutes or less at a construction environment temperature (5 to 35 ° C. in a normal urethane coating agent). it can.
[0017]
Although the method of the present invention is suitable for manual mixing and coating, it can be used for mechanical coating using an automatic mixing device such as a static mixer or a dynamic mixer because the pot life and levelable time can be increased. Can also be applied. In addition, an anti-sagging agent can be blended, and the vertical surfaces, wall surfaces, curved surfaces, etc. can be applied by conventional methods such as rollers, lysing guns, airless guns and the like. It is possible to add a little solvent such as xylene according to workability in the construction.
[0018]
【Example】
The present invention will be further described below with reference to examples and comparative examples. The blending and test results are shown in Table 1. The contents of the items are as follows.
(mixture)
Main agent NCO / curing agent NH2 equivalent ratio: When the main agent prepolymer and the curing agent are mixed at a weight ratio of 1/2, the isocyanate group of the main agent prepolymer and the isocyanate reaction component in the curing agent, that is, the reaction mixture (only Comparative Example 1) Equivalent ratio of DETDA) to amino groups.
[0019]
(Curable)
Pot life: After mixing the main agent and curing agent at 20 ° C, the maximum time (minutes) that can be applied without any problems at this temperature (time until the viscosity of the mixture reaches 100,000 centipoise)
Tack-free time: After the main agent and curing agent are mixed at 20 ° C., this mixed solution is coated on a primer-treated straight plate so as to have a thickness of 1 to 2 mm. Keep track of how long it takes to get rid of stickiness. (time)
(Coating properties) After mixing the main agent and curing agent at 20 ° C., the mixture was cast on a glass plate to a thickness of 1 to 2 mm, cured at 20 ° C. for 7 days, and then JIS. The physical-property test result of the coating film performed according to A6021 .
[0020]
(Bleed type)
After the main agent and curing agent are mixed at 20 ° C., this is coated on a primer-treated straight plate to a thickness of 1 to 2 mm, cured at this temperature for 24 hours, and then coated on this coating film. A one-component moisture-curing urethane primer (TDI-based urethane prepolymer, isocyanate content 2.8% by weight, resin content 30% by weight) is brushed, and the drying property of this primer is checked by touch. If the stickiness remains after 24 hours at 20 ° C., the plasticizer is considered to bleed from the bottom. Those that do not bleed are tack free in 2 to 3 hours.
[0021]
Preparation of main component TDI prepolymer 687.2 g of polypropylene ether diol having an average molecular weight of 2000, 171.8 g of polypropylene ether triol having an average molecular weight of 3000 and 141 g of 2,4-tolylene diisocyanate were charged into a reactor, and the mixture was heated at 80 to 100 ° C. for 5 hours. By reacting, 1000 g of a TDI prepolymer having an isocyanate content of 3.2% by weight was produced. All the main agents used in Table 1 (Examples and Comparative Examples) were used.
[0022]
Preparation of organic diisocyanate prepolymer (1) 945.2 g of polypropylene ether monool having an average molecular weight of 3000 produced by addition polymerization of propylene oxide to butanol as an initiator, and 54.8 g of 2,4-tolylene diisocyanate The reactor was charged and reacted at 80 to 100 ° C. for 5 hours to prepare 1000 g of a prepolymer having an isocyanate content of 1.32% by weight.
A polypropylene ether diol 966.4g Preparation average molecular weight of 10,000 of the organic diisocyanate prepolymer (2), 2, were charged with 4-tolylene diisocyanate 33.6g reactor, reacted for 5 hours at 80 to 100 ° C., isocyanate content A prepolymer of 1000 g with a rate of 0.81% by weight was prepared.
[0023]
Preparation of reaction mixture (isocyanate reaction component in curing agent) Reaction mixture of Example 1: 36 g of DETDA (Etacure 100, above) and 182 g of the above organic diisocyanate prepolymer (1) (the amino group of DETDA) The reaction mixture of Example 1 was prepared by reacting the organic diisocyanate prepolymer (1) with an NCO group in an equivalent ratio of 7/1) at 40 to 50 ° C. for 3 hours. The reaction mixtures of other Examples and Comparative Examples were prepared according to this method. In Comparative Example 1, DETDA was used as it was without using the reaction mixture.
[0024]
Preparation Example of Curing Agent Curing agent of Example 1: 218 g of the above reaction mixture, 152 g of dioctyl phthalate and 630 g of calcium carbonate were charged in a 2 liter cylindrical open container, stirred for 15 minutes at room temperature using a dissolver, and 1000 g A curing agent was prepared. The viscosity of this curing agent was slightly high at 55,000 centipoise at 20 ° C., but when it was mixed with the main agent, the viscosity became low enough that there was no problem in construction. The curing agents of other examples and comparative examples were prepared according to this method except for Comparative Example 2.
[0025]
Examples 1-3
Examples 1 and 2 use the above organic diisocyanate prepolymer (1) as an isocyanate-terminated prepolymer for the production of an isocyanate reaction component, ie, reaction mixture in a curing agent, and DETDA and NH 2 of this organic diisocyanate prepolymer (1). / NCO equivalent ratio is 7 (Example 1) or 11 (Example 2), and the equivalent ratio of the NCO group of the main TDI prepolymer (described above) to the NH2 group of the reaction mixture in the curing agent is 1.1. This is an example of the case. As shown in Table 1, the curing agent in Example 1 has a slightly higher viscosity, and the pot life is slightly shorter than that in Comparative Example 1. The film properties were also good. Regarding the bleeding property of the plasticizer from the cured coating film, it was considered that bleeding was prevented from the fact that the overcoated urethane prepolymer became tack-free in 2 to 3 hours. On the other hand, as will be described later, in Comparative Example 1, even when the overcoated urethane primer was 24 hours or longer, stickiness remained, indicating that the plasticizer was bleeding. As can be seen from the formulation table of Table 1, this allowed the amount of the plasticizer in the curing agent to be reduced from Comparative Example 1 while maintaining the desired pot life in Examples 1 and 2. It is judged as a body.
Example 3 is an example carried out in the same manner as Example 1 or 2 using the organic diisocyanate prepolymer (2) (described above) as the prepolymer for producing the reaction mixture. As a result, the curability and the physical properties of the coating film were good as shown in Table 1, and bleed could be prevented in the same manner as in Examples 1 and 2.
[0026]
Examples 4 and 5
The same isocyanate reaction component (reaction mixture) as in Example 2 was used in the curing agent, and the equivalent ratio of the NCO group of the main TDI prepolymer to the NH2 group of the isocyanate reaction component in the curing agent was determined in Examples 1-3. It is an example when it is made smaller than (1.1) (0.9, Example 4) and when it is made larger (1.4, Example 5). The results are as shown in Table 1. In Example 4, the pot life was slightly shortened, and in Example 5, the curability was slightly slow, but in any case there was no practical problem, and the coating film properties were also good. In addition, bleeding of the plasticizer could be prevented.
[0027]
Comparative Example 1
This is an example in which DETDA is used as it is without using a reaction mixture as an isocyanate reaction component in the curing agent. As a result, the pot life, curability and physical properties of the coating film were good, but as described above, bleeding of the plasticizer from the cured coating film was observed.
[0028]
Comparative Example 2
This is an example in the case where a reaction mixture in the curing agent prepared using DETDA and an organic diisocyanate prepolymer (1) with an NH2 / NCO equivalent ratio of 2.5 is used. In this case, as shown in Table 1, the viscosity of the curing agent was 200,000 centipoise or more at 20 ° C., making it difficult to handle practically. That is, considering the results of Examples 1 to 3, there is a limit value for the equivalent ratio of NH2 groups / NCO groups of DETDA and the organic diisocyanate prepolymer in producing the reaction mixture, and Comparative Example 2 is less than the limit value. It is shown that.
[0029]
Comparative Examples 3 and 4
The same isocyanate reaction component (reaction mixture) as in Example 2 was used in the curing agent, and the equivalent ratio of the NCO group of the main TDI prepolymer to the NH2 group of the isocyanate reaction component in the curing agent was smaller than in Example 4. This is an example of the case (0.7 Comparative Example 3) and the case (2.2, Comparative Example 4). The results are as shown in Table 1. In Comparative Example 3, the pot life was too short, in Comparative Example 5, the curability was slow, and the coating foamed with curing.
[0030]
[Table 1]

That is, considering the results of Examples 2, 4 and 5, in order to achieve the object of the present invention, there is a limit to the equivalent ratio of the NCO group of the main TDI prepolymer to the NH2 group of the isocyanate reaction component in the curing agent. It is shown that Comparative Examples 3 and 4 are outside the range.

Claims (6)

Production of a room temperature curable polyurethane coating material in which the main component, an isocyanate-terminated prepolymer obtained by the reaction of tolylene diisocyanate and polyol, and a curing agent containing an isocyanate reaction component and a plasticizer are mixed, applied, and cured. in the method, the main component of the isocyanate-reactive component in the curing agent, or an organic diisocyanate with a monool the isocyanate-terminated prepolymer obtained by the reaction of Po polyol, the equivalent ratio of amino groups to isocyanate groups of 3: 1 or 30-to-1 below diethyl toluene diamine so as the ratio of the mixed and reacted and the reaction mixture obtained, and the curing agent described above from the previous noted the main agent, and an isocyanate group of the prepolymer in the main agent The equivalent ratio of the isocyanate reaction component to the amino group in the curing agent is 0. Were mixed at the construction site so that the 2.0, the manufacturing method of the cold-setting polyurethane coating material, characterized in that of curing by applying. 2. The production of a room temperature curable polyurethane coating material according to claim 1, wherein the equivalent ratio of the isocyanate group of the prepolymer in the main agent and the amino group of the isocyanate reaction component in the curing agent is 0.9 to 1.5. Method. The manufacturing method of the normal temperature curing type polyurethane coating material of Claim 1 or Claim 2 whose isocyanate group content rate of the isocyanate terminal prepolymer of the above-mentioned main ingredient is 1 to 7 weight%. The tolylene diisocyanate containing 80% by weight or more of 2,4-tolylene diisocyanate is used in producing the main agent which is an isocyanate-terminated prepolymer obtained by the reaction of the tolylene diisocyanate and the polyol. The manufacturing method of the normal temperature curing type polyurethane coating material of any one of Claims 3-5. 5. When producing a main agent that is an isocyanate-terminated prepolymer obtained by the reaction of the above-described tolylene diisocyanate and a polyol, a polypropylene ether polyol or a polyethylene-propylene ether polyol is used as the polyol. The manufacturing method of the room temperature curing type polyurethane coating material as described in a term. The isocyanate-terminated prepolymer obtained by the reaction of the main component Application Benefits diisocyanate with a mono-ol or polyol of isocyanate-reactive component in the curing agent described above, the equivalent ratio of amino groups to isocyanate groups of 3: 1 or more 30: 6. The room temperature curing type polyurethane coating according to claim 1, which is a reaction mixture obtained by mixing diethyltoluenediamine so as to have a ratio of less than 1 and reacting the mixture. Manufacturing method of membrane material.