JPH06298896A - Low-viscosity curable composition for spraying - Google Patents

Abstract

PURPOSE:To obtain a low-viscosity curable composition for spraying having excellent in-situ applicability by using in combination a given hardener and a specific main ingredient comprising a polyisocyanate compound. CONSTITUTION:The composition comprises a polyisocyanate-based main ingredient and a hardener comprising a high-molecular weight active-hydrogen compound [e.g. poly(oxypropylene) glycol] and a chain extender (e.g. ethylene glycol and diethyltolylenediamine), the main ingredient comprising a low-molecular weight polyisocyanate compound which is liquid at room temp. (e.g. carbodiimide-modified 4,4'-diphenylmethane diisocyanate) and/or a mixture of a low-molecular weight polyisocyanate and a plasticizer (e.g. dioctyl phthalate) which mixture is liquid at room temp. due to the plasticizer.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a low-viscosity composition for spray curing which is applied to, for example, flooring materials and waterproof materials. The present invention relates to a method for producing a polyurethane elastomer, which comprises spraying a low-viscosity composition for spray curing onto an object such as a concrete skeleton or a steel plate using a two-liquid high-pressure spray machine to cure the composition.

[0002]

2. Description of the Related Art A technique of collision-mixing a urethane elastomer in a state where the raw material viscosity is low and molding at a high speed is known as a RIM method. It is also practiced to further reduce the viscosity of the raw material used here and to perform spray processing. Spray processing is mainly used in the field of molding rubber-like elastic materials such as flooring materials, and has been used as a flooring material applied to concrete foundations such as open corridors and rooms.

The raw materials used in the spray processing are similar to those used in the RIM method and use two components, an isocyanate component consisting of an isocyanate group-containing polyurethane prepolymer and a polyol component consisting of a high molecular weight active hydrogen compound. I often do it. For example, as a method for producing a super rapid curing type polyurethane elastomer, a polyisocyanate component containing an isocyanate group-containing polyurethane prepolymer as an A agent, a polymer active hydrogen compound and a chain extender as a B agent, and an A agent and a B agent are used. There is a spray method in which mixing is performed at a volume ratio of 1: 1.

However, since these have a polyurethane prepolymer as a main component and have a too high viscosity at room temperature, it is necessary to heat them to 50 to 70 ° C. during spraying.

[0005]

Conventionally, the liquid temperature must be raised to 50 to 70 ° C. in order to adjust the viscosity so that it can be sprayed. Therefore, the material tank to the pipe is completely kept warm by a heater and a heat insulating material. , It was necessary to control the temperature. In addition, there is a problem that such preparation work before spraying takes much time. Further, there is a problem that the quality of the isocyanate raw material deteriorates due to heat deterioration due to heating.

[0006]

The present invention has been made to solve the above problems, that is, the following inventions.

In a low-viscosity composition for spray curing, which comprises two components, a main component containing a polyisocyanate compound and a curing agent containing a high molecular weight active hydrogen compound and a chain extender, the main component is liquid at room temperature. A low-viscosity composition for spray curing, comprising a low-molecular weight polyisocyanate compound, and / or a low-molecular weight polyisocyanate compound that is liquid at room temperature due to a plasticizer, and a plasticizer.

A low-viscosity composition for spray curing comprising two components, a main component containing a polyisocyanate compound, a high-molecular weight active hydrogen compound and a curing agent containing a chain extender, is prepared by using a two-pack high pressure spray machine. A method for producing a polyurethane elastomer, which comprises spraying an object to be cured.

In the present invention, the main component is composed of a low molecular weight polyisocyanate compound which is liquid at room temperature, and / or a low molecular weight polyisocyanate compound which is liquid at room temperature by a plasticizer, and a plasticizer. It is a thing. Since the main component does not substantially contain a polyurethane prepolymer or the like, which is a reaction product of a high molecular weight polyol and a polyisocyanate compound, it can be liquid at room temperature.

Examples of the low molecular weight polyisocyanate compound which becomes liquid by the plasticizer include 4,4'-diphenylmethane diisocyanate, paraphenylene diisocyanate, 1,5-naphthalene diisocyanate, tolidine diisocyanate and paratetramethylxylylene diisocyanate. .

Examples of the low molecular weight polyisocyanate compound which is liquid at room temperature include 65/35 of 2,4-toluene diisocyanate and 2,6-toluene diisocyanate.
~ 90/10 mixture, xylylene diisocyanate,
Carbodiimide modified products of 4,4′-diphenylmethane diisocyanate, polymethylene polyphenyl isocyanate and the like can be mentioned.

In the present invention, as the polyisocyanate compound, a carbodiimide modified product of 4,4'-diphenylmethane diisocyanate which is liquid at room temperature is particularly preferable.

As the plasticizer, phthalic acid dimethyl ester, phthalic acid diethyl ester, phthalic acid dibutyl ester, phthalic acid dioctyl ester, adipic acid dioctyl ester, and other ester plasticizers, polyoxyalkylene polyol acetic acid ester plasticizers, Chlorinated paraffin plasticizers are preferred.

The main component preferably contains 10 to 60% by weight of a plasticizer, and particularly preferably 30 to 50% by weight. If it is less than 10% by weight, it is necessary to increase the content of the hydroxyl group and amino group of the curing agent according to the content of the isocyanate group of the main agent, the hardness of the obtained polyurethane elastomer becomes too high, and the elongation elasticity becomes insufficient. Become.
Also, if it exceeds 60% by weight, the mechanical strength becomes insufficient,
This results in the bleed-out phenomenon of the plasticizer.

The high molecular weight active hydrogen component contained in the curing agent component is preferably polyoxyalkylene polyol. The polyoxyalkylene polyol is preferably one obtained by ring-opening polymerization of alkylene oxide in the presence of a catalyst as an initiator having at least two active hydrogen-containing groups.

As the initiator, water, ethylene glycol, propylene glycol, diethylene glycol, triethylene glycol, dipropylene glycol, trimethylene glycol, 1,4-butanediol, 1,5
-Pentanediol, 1,6-hexanediol, glycerin, trimethylolpropane, bentaerythritol and the like.

Examples of the alkylene oxide include ethylene oxide, propylene oxide and butylene oxide. Polymerization of these alkylene oxides may be homopolymerization, random copolymerization or block copolymerization.

The number of functional groups of the polyoxyalkylene polyol is preferably 2-8, and more preferably 2-3. From the viewpoint of viscosity, it is preferable to use only polyoxyalkylene diol, but it is also preferable to use a mixture of polyoxyalkylene diol and polyoxyalkylene triol in order to improve strength.

A molecular weight of 400 to 15,000 can be used. Particularly, those having a viscosity of 400 to 5,000 are preferable, and those having a viscosity of 400 to 3,000 are more preferable because they have a lower viscosity.

As the chain extender in the present invention, a low molecular weight diol such as ethylene glycol, propylene glycol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, diethylene glycol, dipropylene glycol, Tripropylene glycol, triethanolamine; aromatic polyamines such as tolylenediamine, diaminodiphenylmethane, diethyltolylenediamine, tetramethylxylylenediamine, xylylenediamine, t-butyltoluenediamine; alkanolamines such as triethanolamine. , Diethanolamine and the like can be used.

Particularly, low molecular weight diols such as ethylene glycol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, diethylene glycol, dipropylene glycol and tripropylene glycol are preferred.

The hardener component can also include a plasticizer.
As such a plasticizer, the same compounds as those mentioned above can be used.

A catalyst may be contained in the curing agent component. As the catalyst, a known catalyst can be used as a urethanization catalyst. Further, additives such as colorants may be included in the curing agent component.

In the present invention, two components, a main component containing the above polyisocyanate compound, a plasticizer, a high molecular weight active hydrogen compound, a chain extender and, if necessary, a curing agent containing a catalyst, a plasticizer and other additives, A polyurethane elastomer is manufactured by being jetted from a two-liquid high-pressure spray machine at a predetermined flow rate ratio and sprayed on an object to be cured.

[0025]

【Example】

[Example 1] A mixture of 60 parts of 143 L isonate (carbodiimide-modified liquid MDI manufactured by Kasei Dow Co., Ltd.) and 40 parts of dioctyl phthalate was used as a main component. This mixture had a low viscosity of 55 cps (20 ° C.) and had an isocyanate group content of 16.95%.

On the other hand, 82 parts of polyoxypropylene diol having a molecular weight of 1050 and 10 parts of diethyltolylenediamine
Parts, ethylene glycol 4 parts, dioctyl phthalate 4
Parts and DABCO-33LV (a mixture of triethylenediamine and dipropylene glycol in a weight ratio of 1: 2) 1 part,
A mixture of 0.5 parts of lead octylate was used as a curing agent.
The (hydroxyl value + amine value) of this mixture is 225 (mgK
The viscosity was 300 cp (20 ° C.) at OH / g).

Example 2 40 parts of a compound obtained by acetylating the end of polyoxypropylene diol having a molecular weight of 2000 with acetic anhydride as a plasticizer and 143 L of isonate.
The main component was 60 parts of the mixture. This mixture has a viscosity of 100
It had a low viscosity of cps (20 ° C.) and an isocyanate group content of 17.29%.

On the other hand, 71 parts of polyoxypropylene diol having a molecular weight of 2200 and diethyl tolylenediamine 17
Parts, ethylene glycol 3 parts, dioctyl phthalate 8
Parts and DABCO-33LV 1 part, lead octylate 0.5
A mixture of parts was used as a curing agent. The (hydroxyl value + amine value) of this mixture is 198 and the viscosity is 500 cp (20 ° C.).
showed that.

[Comparative Example 1] 37.4 parts of 125M isonate (MDI manufactured by Kasei Dow Co., Ltd.) and 143L of isonate.
52 parts of polyoxypropylene diol having a molecular weight of 3000 was reacted with 3.4 parts of the mixture at 80 ° C. for 4 hours, and 8 parts of dioctyl phthalate was mixed to obtain a main agent. The mixture had a viscosity of 1200 cp (20 ° C.) and a high viscosity of 12.15% isocyanate group content.

On the other hand, 74 parts of polyoxypropylene diol having a molecular weight of 2000 and 16 parts of diethyltolylenediamine
Parts, dioctyl phthalate 10 parts and DABCO-33L
A mixture of 1 part of V and 0.5 part of lead octylate was used as a curing agent. This mixture has a hydroxyl value + amine value of 139
The viscosity was 600 cp (20 ° C.).

Example 3 15 parts of polyoxypropylene diol having a molecular weight of 2,000 was acetylated with acetic anhydride as a plasticizer, and 143 L of isonate was used.
The main component was 85 parts of the mixture. This mixture has a viscosity of 50c
It showed an isocyanate group content of 24.51% at ps (20 ° C.) and low viscosity.

On the other hand, 71 parts of polyoxypropylene diol having a molecular weight of 700, 17 parts of diethyltolylenediamine,
A mixture of 3 parts of ethylene glycol, 8 parts of dioctyl phthalate, 1 part of DABCO-33LV and 0.5 part of lead octylate was used as a curing agent. This mixture had a (hydroxyl value + amine value) of 273 and a viscosity of 300 cp (20 ° C.).

Example 4 65 parts of a polyoxypropylene diol having a molecular weight of 2000 and a terminal compound acetylated with acetic anhydride as a plasticizer, 143 L of isonate.
The main component was 35 parts of the mixture. This mixture has a viscosity of 100
It showed an isocyanate group content of 9.88% at a low viscosity of cps (20 ° C.).

On the other hand, 78 parts of polyoxypropylene diol having a molecular weight of 3000 and 10 parts of diethyltolylenediamine
Part, ethylene glycol 2 parts, dioctyl phthalate 1
0 part and DABCO-33LV 1 part, lead octylate 0.
A mixture of 5 parts was used as a curing agent. This mixture has a (hydroxyl value + amine value) of 128 and a viscosity of 60000 cp (20
° C).

[Practical Application] The two components of Examples 1 to 4 and Comparative Example 1 described above were used as a molding machine and manufactured by Gasmer H-2.
A mold release film was placed on the floor using a 000 high pressure spray machine and a propeller gun manufactured by Glass Craft Co., Ltd. as a spray gun, and sprayed to mold a polyurethane elastomer. However, in Comparative Example 1 only, a normal spray pattern could not be obtained at room temperature, so both the main agent and the curing agent were heated.

Table 1 shows the molding processability of each component and the mechanical properties of the molded sheet. However, reactivity is tack free time (TFT, unit: second), gel time (GT, unit: minute)
Indicated by. Hardness is Shore A standard, unit of tensile strength is k
The unit of g / cm ² , tear strength is kg / cm, and the unit of elongation is%. The bleed-out property was evaluated by visually observing the state of bleed-out after 7 days at 60 ° C. ◯ means good, and x means bad.

[0037]

[Table 1]

[0038]

In the present invention, since the urethane prepolymer obtained by reacting the polyisocyanate and the polyol is not used as the isocyanate component, the viscosity is extremely low.
Furthermore, since it is possible to finely adjust the viscosity arbitrarily by combining different types of plasticizers, it is not necessary to specially heat the raw material during spraying, or it is possible to perform spraying with minimal heating in winter, etc. Significantly improved. Moreover, since no urethane prepolymer is used, the labor for synthesizing and manufacturing the main component is not required, and the compounding can be performed on site.

Claims (6)

[Claims] 1. A low-viscosity composition for spray curing comprising two components, a main component containing a polyisocyanate compound and a curing agent containing a high molecular weight active hydrogen compound and a chain extender, wherein the main component is liquid at room temperature. And a low-molecular weight polyisocyanate compound which is liquid at room temperature with a plasticizer, and a plasticizer, and a low-viscosity composition for spray curing. 2. The low viscosity composition for spray curing according to claim 1, wherein the polyisocyanate compound is a carbodiimide-modified polyisocyanate. 3. The low-viscosity composition for spray curing according to claim 1, wherein the polyisocyanate compound is a 4,4′-diphenylmethane diisocyanate compound. 4. The low-viscosity composition for spray curing according to claim 1, wherein the main component contains 10 to 60% by weight of a plasticizer. 5. The curing agent component contains at least one selected from a catalyst, a colorant and a plasticizer.
A low viscosity composition for spray curing. 6. A composition selected from the group consisting of a main component containing a polyisocyanate compound and a curing agent containing a high molecular weight active hydrogen compound and a chain extender.
A method for producing a polyurethane elastomer, which comprises spraying the low-viscosity composition for spray-curing according to item 1 above onto an object using a two-liquid high-pressure spray machine to cure the composition.