JPH11240932A - Method for producing cold-setting polyurethane waterproofing material - Google Patents

Abstract

(57) [Summary] [PROBLEMS] Although DETDA, which is a highly safe aromatic polyamine crosslinking agent, can be used in place of MOCA, which is a designated chemical substance, adhesion to top coating materials such as top coats and pavement materials is insufficient. Then solve the problem. An isocyanate-terminated prepolymer obtained by reacting a polyol with TDI and an aliphatic or cycloaliphatic polyisocyanate have a molar ratio based on respective NCO groups of 98/2 to 70/30. By mixing and coating the main agent mixed with a curing agent containing DETDA and a plasticizer at room temperature in an equivalent ratio of NCO groups to NH ₂ groups of 0.8 to 2.0, and coating and curing the mixture. Improved adhesion to topcoat materials such as topcoats and paving materials.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polyurethane waterproofing material which cures at room temperature, and more particularly to a method for producing a room temperature curing type polyurethane waterproofing material having excellent adhesion to an overcoat material.

[0002]

2. Description of the Related Art Polyurethane-coated flooring materials and waterproofing materials have hitherto been used in large quantities for applications such as waterproofing roofs of buildings, verandas and corridors, and elastic pavement of sports facilities. The method for producing such a coated flooring material and waterproofing material is based on an isocyanate-terminated prepolymer obtained by a reaction between a polyol such as polyoxypropylene polyol and tolylene diisocyanate (hereinafter abbreviated as TDI), and 4,4 ′ -Methylene-bis (2-chloroaniline)
[Hereinafter abbreviated as MOCA] and polyoxypropylene polyol as an isocyanate reaction component, a catalyst such as organometallic lead, and a plasticizer, if necessary, are blended as a curing agent. After mixing at the construction site, the mixture is hand-coated with a trowel, a spatula, a rake or the like and cured.

In this conventional method, MOCA used as a main component of an isocyanate reaction component in a curing agent is:
Although it is a designated chemical substance, there is a problem with safety.At room temperature, the reaction with isocyanate is relatively slow despite its solid stability and high crystallinity, which makes it difficult to handle due to poor solubility in plasticizers. The pot life required especially as a coated flooring material and a waterproofing material (the time required for mixing the two liquids before applying them without any problem. In general, the time required for the viscosity to reach 100,000 centipoise after mixing and ) Was obtained, and furthermore, various physical properties required for a urethane-coated flooring material and a waterproofing material could be maintained, so that it was almost the only aromatic polyamine crosslinking agent usable in this field.

Recently, a physiologically safe and highly reactive diethyltoluenediamine (hereinafter referred to as DETD) has been substituted for this MOCA.
A) is used as the main component of the aromatic polyamine cross-linking agent, and a rapid-curing polyurethane waterproofing material that can be cured at room temperature in combination with a conventionally used TDI prepolymer has been developed. However, the waterproofing material obtained by this method has insufficient adhesion to an overcoating material such as a top coat or a pavement material, and has been required to be improved.

[0005]

SUMMARY OF THE INVENTION The present invention provides a highly safe aromatic polyamine crosslinking agent in place of MOCA, which is a designated chemical substance, and has improved adhesiveness to an overcoating material such as a top coat or a pavement material. The purpose was to develop a room temperature-curable polyurethane waterproofing material that would not cause any concerns.

[0006]

As a result of various studies, the present inventors have found that as a polyisocyanate which is a main component of the main agent,
In addition to the conventionally used TDI prepolymer, an aliphatic or alicyclic diisocyanate-based polyisocyanate was mixed, and a highly reactive aromatic polyamine crosslinking agent and a plasticizer containing DETDA as a main component were compounded. The inventors have found that by mixing, coating, and curing a curing agent at a predetermined ratio, the adhesiveness with a topcoat material such as a top coat or a pavement material is remarkably improved, and the present invention has been completed.

[0007] That is, the first invention of the present invention is to provide a coating composition by mixing a main agent containing polyisocyanate as a main component and a curing agent containing an aromatic polyamine crosslinking agent containing DETDA as a main component and a plasticizer. A water-curable polyurethane waterproofing material to be cured, a) as a polyisocyanate, an isocyanate-terminated prepolymer obtained by reacting TDI with a polyol, and an aliphatic or alicyclic diisocyanate monomer;
Using a mixture of oligomers or aliphatic or cycloaliphatic diisocyanate monomers and isocyanate-terminated prepolymers obtained by reacting polyols; b) the mixing ratio of the mixtures is such that the molar ratio based on the respective isocyanate groups is 98/2 And c) mixing and coating the main agent and the curing agent such that the equivalent ratio of the isocyanate group in the main agent to the amino group in the curing agent is 0.8 to 2.0. A method for producing a cold-setting polyurethane waterproofing material characterized by being cured, wherein the second invention uses isophorone diisocyanate as the aliphatic or alicyclic diisocyanate of the first invention, The invention of 3 contains 85% by weight or more of 2,4-tolylene diisocyanate as the tolylene diisocyanate of the first invention. It is to use the TDI.

In the present invention, among the polyisocyanates which are the main components of the main component, one of the TDI prepolymers has been conventionally used as an isocyanate component of a cold-curable polyurethane waterproofing material. The isocyanate group (hereinafter abbreviated as NCO group) and the OH group of the polyol are prepared such that the equivalent ratio thereof is about 2 or so, and the mixture is reacted. Raw material TD
As I, those having a 2,4-isomer content of 65 to 100% by weight, which are commercially available, can be used.
The use of a prepolymer prepared from TDI having a low isomer content as a raw material as a main component of the base material tends to shorten the pot life, and therefore, the 2,4-isomer content is 80% by weight or more in the present invention. It is desirable to use
Most preferred is at least 85% by weight.

The other polyisocyanate used in the present invention is an aliphatic or alicyclic diisocyanate monomer, oligomer or isocyanate-terminated prepolymer obtained by reacting these monomers with a polyol. Examples of the aliphatic or alicyclic diisocyanate include monomers such as hexamethylene diisocyanate (abbreviated as HDI) and isophorone diisocyanate (abbreviated as IPDI) such as hydrogenated xylene diisocyanate. Examples include an adduct of methylene diisocyanate, hydrogenated xylene diisocyanate or isophorone diisocyanate and trimethylolpropane, or an isocyanurate of hexamethylene diisocyanate or isophorone diisocyanate, and a prepolymer obtained by reacting these monomers with a polyol. Isocyanate-terminated prepolymers.

In the present invention, the TDI prepolymer and the above-mentioned aliphatic or alicyclic diisocyanate-based polyisocyanate are mixed at a molar ratio based on each NCO group of 98/2 to 70/30. use.
When the ratio is 98/2 or more, the effect of mixing an aliphatic or alicyclic polyisocyanate is not clear, and when the ratio is 70/30 or less, the working life becomes too short when a mixture of an aliphatic or alicyclic diisocyanate monomer is used, so that it becomes practical. Even if these monomers, oligomers or prepolymers are further mixed, no remarkable improvement is observed in the effect of improving the adhesion. For example, the mixing of isophorone diisocyanate monomer has the effect of improving the adhesiveness, but tends to shorten the pot life, but the mixing of an isocyanate-terminated prepolymer obtained by the reaction of isophorone diisocyanate with a polyol has the effect of improving the adhesiveness. The effect of extending the pot life together with the effect of is recognized. Therefore, as the aliphatic or alicyclic polyisocyanate to be mixed with the TDI prepolymer in the present invention, it is more preferable to use an oligomer or a prepolymer. It is also possible to mix an isophorone diisocyanate prepolymer containing a small amount of a monomer in order to efficiently exert the effect of improving the adhesiveness while maintaining the pot life.

The polyol which is another raw material used for producing the isocyanate-terminated prepolymer includes:
Polyoxypropylene polyols or polyols generally known as ordinary urethane raw materials such as polyoxyethylene propylene polyol, polyoxytetramethylene glycol, polycaprolactone polyol and polyester polyol can be used. Among these general polyols, in the field of the present invention, it is preferable to use polyoxypropylene polyol or polyoxyethylene propylene polyol in view of viscosity or crystallinity at low temperature.

The NCO content of the polyisocyanate is 1 to
It is preferably 7% by weight. When the amount exceeds 7% by weight, it becomes difficult to secure a desired pot life when combined with the curing agent used in the present invention. On the other hand, when the amount is less than 1% by weight, desired physical properties are obtained as a polyurethane waterproofing material. Disappears. The most preferable range is 1.5 to 5.0% by weight.
It is. 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-diamine having a different isomer content is commercially available. As a commercially available product, for example, “Etacure 100” (trade name, manufactured by Ethylene Corporation, 2,4-isomer / 2,6-
A weight ratio of isomers of 80/20) and the like can be used. This D
ETDA has already been registered in Japan as an existing chemical substance, and unlike the prior art MOCA, it is safe and has no restrictions on production and use.

[0013] The plasticizer used in the present invention comprises a base agent such as dibutyl phthalate, diheptyl phthalate, dioctyl phthalate, butylbenzyl phthalate, dioctyl adipate, chlorinated paraffin, tris-β-chloropropyl phosphate, etc. Of isocyanate terminated prepolymer of
Usual plasticizers that are not reactive with O groups can be used. The amount of the plasticizer in the curing agent is desirably in the range of 20 to 130 parts by weight based on 100 parts by weight of the base polyisocyanate. If the amount is less than 20 parts by weight, it is difficult to maintain the desired pot life, and if it exceeds 130 parts by weight, the plasticizer tends to bleed on the surface of the coating film, and the cured coating film cannot maintain the desired strength.

The polyol used as a crosslinking agent component in the conventional MOCA-polyol combined curing agent is not an essential component in the curing agent of the composition of the present invention and need not be blended. However, the reactivity is lower than DETDA, especially in the initial stage of curing, because it has the same action as a plasticizer that delays the reaction of DETDA, regardless of whether the polyol eventually undergoes isocyanate reaction,
A small amount of a polyol can be blended as a plasticizer. In the present invention, since a highly reactive aromatic polyamine crosslinking agent called DETDA is used, a conventionally used curing accelerating catalyst is not an essential component and is not used in principle. However, as required in the case of construction in the winter or when a polyol is used in combination with a curing agent, a curing catalyst such as an organic metal catalyst such as lead octoate or lead naphthenate or an organic acid such as octylic acid or oleic acid is used. Can be used in small quantities. For example, when using lead octoate (lead content: 20% by weight), by adding a small amount of 3% by weight or less to the curing agent, rapid curing can be achieved even in a severe winter season. With this amount of catalyst, the heat resistance of the cured coating film does not deteriorate.

The curing agent used in the present invention may include, if necessary, inorganic fillers such as calcium carbonate, talc, kaolin, zeolite, and diatomaceous earth, and pigments such as chromium oxide, red iron oxide, iron oxide, carbon black, and titanium oxide. And hindered amine-based, hindered phenol-based, and benzotriazole-based stabilizers. The waterproofing material of the present invention comprises a main component mainly composed of a mixture of a TDI prepolymer and an aliphatic or alicyclic polyisocyanate at a predetermined ratio, an aromatic polyamine crosslinking agent mainly composed of DETDA, and a plasticizer. A curing agent containing a polyol, an inorganic filler, a catalyst, a stabilizer, a pigment and the like, if necessary, is combined with an NCO group in the main agent and an amino group (NH) in the curing agent.
₂ ) at the construction site so as to have an equivalent ratio of 0.8 to 2.0, hand-coated on the target surface, and cured. NCO group in main agent and NH in hardener
_If the equivalent ratio of the _two groups is less than 0.8, the desired pot life cannot be secured, and the yellowing due to free amine becomes severe, whereas if it exceeds 2.0, the curability becomes too slow and the fast curability Will not be shown. By mixing the main agent and the curing agent at the above-described ratio, the mixture is used for 30 minutes or more at a construction environment temperature (5 to 35 ° C. for a normal urethane waterproofing material or a coated flooring material).
It is possible to obtain a polyurethane waterproofing material which can maintain a pot life of 0 minute or less and has good adhesion to an overcoating material.

The waterproofing material of the present invention is suitable for manual mixing and coating, but uses an automatic mixing device such as a static mixer or a dynamic mixer because the working time and the leveling time are long. It can also be carried out by a mechanical coating. In addition, by selecting an inorganic filler or blending an organic sagging stopper, it is possible to construct an upright surface, a wall surface, a curved surface, or the like by a method using a roller, a ricin gun, an airless gun, or the like. In addition, the waterproofing material of the present invention can be used as a conventional waterproofing material or a coated flooring material, for reducing soundness of corridors and stairs, protecting mortar, and preventing corrosion of flooring materials and metals for dustproofing purposes. It can also be used as a rust material and caulking material. At the time of construction, a small amount of a solvent such as xylene or toluene can be added depending on workability.

[0017]

The present invention will be further described below with reference to examples and comparative examples. The materials and test items used in the examples and comparative examples are as follows. (Main agent) TDI prepolymer: 2 liter glass corvene,
148.2 g of TDI (Example 1, only 2,4- / 2,6 isomer content 80 /
20 weight ratio used, all other 2,4-isomer 1
001.4%) and 681.4 g of Actcol P-2020 (polyoxypropylene diol having a molecular weight of 2000, manufactured by Takeda Pharmaceutical Company Limited) and 170.4 g
ACTCOL P-3030 (polyoxypropylene triol having a molecular weight of 3000, manufactured by Takeda Pharmaceutical Company Limited) is gradually added, and the mixture is heated to 80 ° C., heated to 90 to 100 ° C. with stirring, and kept at this temperature for 5 hours to carry out the reaction. To complete the NCO
NCO-terminated TDI prepolymer 1 with a content of 3.5% by weight
000 g was prepared. The TDI prepolymers of Examples and Comparative Examples were all used. IPDI monomer: Isophorone diisocyanate, manufactured by Hyurs IPDI prepolymer: 183.2 g of IPDI, 653.4 g of Actol P-2020 and 163.4 g of Actol P-3 in a 2 liter glass corvene.
030 was added, 0.01 g of dibutyltin dilaurate was added with stirring, and the mixture was gradually heated to 80 to 100 ° C. and stirred at this temperature for 4 hours to complete the reaction.
1000 g of an NCO-terminated IPDI prepolymer with a CO content of 3.5% by weight were prepared. IP of Examples and Comparative Examples
This was used for all DI prepolymers. HDI isocyanurate: trimer of hexamethylene diisocyanate, manufactured by Nippon Polyurethane Industry Co., Ltd., trade name: Coronate HX, NCO content: 21.4% by weight. (Curing agent) DETDA: diethyltoluenediamine, trade name: ETAKIUA 100, manufactured by Ethyl Corporation. DOP: dioctyl phthalate, plasticizer, manufactured by Daihachi Chemical Industry Co., Ltd. Calcium carbonate: inorganic filler, manufactured by Maruo Calcium.

Preparation of Curing Agent: A 2-liter cylindrical open container was charged with DETDA (62 g), DOP (658 g) and calcium carbonate (1280 g), and stirred at room temperature for 15 minutes using a dissolver to prepare 2000 g of a curing agent. All of the curing agents used in Examples and Comparative Examples were used. Mixing: The main agent and the curing agent were all mixed at a weight ratio of 1: 2. Main agent / curing agent NCO / NH ₂ equivalent ratio: The ratio of the NCO group of the main agent to the NH ₂ equivalent of the curing agent during mixing. Pot life: time (minutes) until the viscosity of the mixture reaches 100,000 centipoise after mixing the main agent and the curing agent at 20 ° C. (Use as a guideline for the maximum time that the waterproofing material can be applied without hindrance.) Adhesion: One-part urethane primer CB-
40 (manufactured by Hodogaya Kenzai Kogyo Co., Ltd.), and after it was dried (after about 4 hours), the main agent and the curing agent were mixed at a ratio of 1: 2 by weight according to the prescription of Example. The solution was applied so as to be 2 kg per square rice, and this was applied to 35 kg.
The sample was allowed to stand under an atmosphere at a temperature of 40 ° C. and a relative humidity of 40% to prepare a test piece of a polyurethane waterproof material. After curing under these conditions for two days, a two-component urethane flooring as an overcoating material thereon,
HC Park (Hodogaya Construction Materials Co., Ltd.) 1k per square meter
g, and left under the same conditions for 7 days to prepare a test piece for adhesion test. After 7 days, the temperature was returned to a normal temperature of 20 ° C., and the adhesion between the waterproof material and the topcoat material was tested by a 180 ° peel test. In the test results, the symbol ○ indicates that
The material of the waterproofing material was destroyed, indicating that the adhesiveness was good. The symbol x indicates that the adhesive was peeled off at the interface between the waterproofing material and the overcoating material, and that the adhesion was poor.

Examples 1 to 4 Examples of the case where an IPDI prepolymer is used as an aliphatic or alicyclic polyisocyanate to be used by mixing with a TDI prepolymer as a base material. In each case, the TDI prepolymer and IPD prepared according to the above-mentioned preparation examples of the base material
I prepolymer was used. However, unlike the other examples, only the TDI prepolymer of Example 1 is a case where a prepolymer using TDI having a 2,4- / 2,6-isomer content of 80/20 by weight is used. The results are as shown in the table.

[0020]

[Table 1]

[0021]

[Table 2]

When Examples 1 and 2 are compared, the pot life is shorter in the case of 1, and the TD having a large 2,4-isomer content is used.
This shows that 2 using I is more preferable in securing the pot life. It was found that the adhesiveness was all good and was improved as compared with Comparative Example 1 (described later). Examples 3 and 4 are examples in which the mixing amount of the IPDI prepolymer was increased from 1 or 2. As shown in the results,
The working life tended to increase as the mixing amount of the PDI prepolymer increased, and the adhesiveness was all good.

Examples 5, 6 and 7 Example 5 is an example in which an IPDI monomer was used as an aliphatic or alicyclic polyisocyanate to be used by mixing with a TDI prepolymer. Is an example in which HDI isocyanurate is mixed as an oligomer of an aliphatic diisocyanate. As shown in Table 1, in Example 5, the adhesiveness was good, but the pot life was slightly shortened, indicating that the IPDI monomer had an effect on the pot life reduction. In Example 6, since the IPDI prepolymer was used in addition to the IPDI monomer, it was found that, unlike the case of 5, the adhesion could be improved without substantially affecting the pot life. In the seventh embodiment, H
Although DI isocyanurate has been shown to have an effect of improving adhesiveness, it was also found that the pot life was shortened.

Comparative Examples 1 to 4 Comparative Example 1 was a case where only the TDI prepolymer was used as the main agent, and the adhesion was poor. Comparative Examples 2 and 3 are cases where a small amount of the IPDI prepolymer (2) or the IPDI monomer (3) was mixed in addition to the TDI prepolymer, and as shown in Table 2, little improvement was observed in the adhesiveness. Was. Comparative Example 4 contained IPD in the base material.
This is an example in which the I monomer is mixed in a large amount of 36 mol%. As shown in the results, it was found that the adhesiveness was improved, but the pot life was shortened to such an extent that it was not practical. That is, considering these results and the results of the examples,
In order to improve the adhesion while maintaining the pot life,
There is an effective range for the amount of the aliphatic or alicyclic polyisocyanate to be mixed with the TDI prepolymer as the main agent, and Comparative Examples 2, 3 and 4 show that all of them are outside the range.

[0026]

According to the present invention, in a cold-setting polyurethane waterproofing material comprising a main component mainly composed of a TDI prepolymer and a curing agent containing a DETDA and a plasticizer, a limited amount of an aliphatic or alicyclic ring in addition to the TDI prepolymer. Use a base material mixed with aromatic polyisocyanate

Claims (3)

[Claims] 1. A room temperature curing type in which a main agent containing polyisocyanate as a main component and a curing agent containing an aromatic polyamine crosslinking agent containing diethyltoluenediamine as a main component and a plasticizer are mixed, coated and cured. In a polyurethane waterproofing material, a) as a polyisocyanate, an isocyanate-terminated prepolymer obtained by reacting tolylene diisocyanate with a polyol, an aliphatic or alicyclic diisocyanate monomer, an oligomer or an aliphatic or alicyclic diisocyanate monomer and a polyol B) using a mixture with the isocyanate-terminated prepolymer obtained by the reaction of b), the mixture ratio of the mixture being a ratio of 98/2 to 70/30 based on the respective isocyanate groups; And the isocyanate in the main ingredient A method for producing a room-temperature-curable polyurethane waterproofing material, which comprises mixing, coating, and curing the mixture so that the equivalent ratio of the thiol group to the amino group in the curing agent is 0.8 to 2.0. 2. The method for producing a cold-setting polyurethane waterproofing material according to claim 1, wherein isophorone diisocyanate is used as the aliphatic or alicyclic diisocyanate. 3. A tolylene diisocyanate comprising 2,4
The method for producing a cold-setting polyurethane waterproofing material according to claim 1, wherein tolylene diisocyanate containing 85% by weight or more of tolylene diisocyanate is used.