JPS61296018A - Polyurethane elastomer composition and mechanical application method thereof - Google Patents

Abstract

PURPOSE:The titled quick-curing two-pack type composition, consisting of a urethane prepolymer, long-chain polyol having a specific molecular weight as a curing agent, aromatic amine, urethanating catalyst and heat-resistant stabilizer, having improved coating properties and external appearance of films and low viscosity and useful for mechanical application. CONSTITUTION:A composition obtained by incorporating (A) a urethane prepolymer having NCO groups at the molecular ends with (B) a long-chain polyol having 1,000-8,000 molecular weight as a curing agent, preferably polyoxyalkylene glycol, (C) an aromatic amine, e.g. 3,3'-dichloro-4-diaminod iphenylmethane, (D) a urethanating catalyst, e.g. lead octylate, and (E) a heat- resistant stabilizer, e.g. tetraethylthiuram disulfide, as essential components and, as necessary, adding a plasticizer, filler, colorant, defoaming agent and another assistant thereto and uniformly mixing them.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) The present invention relates to a two-component fast-curing polyurethane elastomer composition and a method for forming a coating film of the polyurethane elastomer using an application machine.

(Prior technology) Polyurethane entomers are used in the building materials field, especially waterproof materials,
It is used in large quantities in flooring, elastic pavers and similar ports.

For these applications, two-component types are mostly used, and the viscosity of the prepolymer ranges from 30,000 to 50,000 cp.
s/15℃, the viscosity of the curing agent is 100,000 cps/1
The temperature is 5℃ or higher, and the application work is usually done manually using a trowel, rake, squeegee, etc., so materials whose pot life is generally adjusted to 40 to 90 minutes at the on-site construction temperature are used. Tack free time is 4
Hours to several hours.

(Problem to be solved by the invention) As a result, curing is slow, and when recoating is usually done on the next day, work efficiency is poor and work is greatly affected by weather etc. It had a drawback.

Therefore, instead of conventional batch stirring, the present inventors carried out stirring using mechanical stirring in a short time, and by immediately flowing the mixed liquid onto the substrate, the present inventors succeeded in on-site construction of a polyurethane composition with an extremely short pot life. We considered its application to

However, according to conventional knowledge, it was thought that materials with a short pot life of 5 to 20 minutes do not level and it is impossible to create a uniform coating film.

It is clear and unexpected that if materials with short pot life can be applied evenly, they will cure faster, can be coated several times a day, and be less susceptible to weather conditions. The viscosity of the prepolymer and curing agent is lowered, and the viscosity at 15°C 2 minutes after the start of mixing is 1.0.000 cp.
It has been found that polyurethane compositions with a temperature of 15° C. or higher can be sufficiently leveled during mechanical application at temperatures of 15° C. or higher, and a uniform coating film can be formed. That is, it has been found that after mechanical mixing, a low viscosity, fast-curing stock solution can be applied with good leveling and without air bubbles by discharging the mixed solution in a slit, fan shape, or curtain shape.

By the way, the fast-curing polyurethane distful composition of the present invention varies depending on the amount of highly active amine used in combination, but
In order to promote the reaction, it is necessary to use a fairly large amount of catalyst, and therefore the cured product is susceptible to thermal deterioration due to the catalyst remaining in the cured product, especially the lead catalyst. Therefore, a heat-resistant stabilizer was added for the purpose of preventing thermal deterioration, and this drawback was solved, and the present invention was achieved.

That is, the present invention is as follows.

(1) Urethane e with isocyanate group at the end of the molecule
Prepolymer, molecular weight 1. ．． A low-viscosity, fast-curing, two-component polyurethane composition for mechanical construction consisting of a curing agent made by homogeneously kneading a long-chain polyol of 000 to 8,000, an aromatic amine, and a urethanizing catalyst. The two-component polyurethane composition for mechanical construction according to claim 1, wherein the urethane prepolymer has a viscosity of 10.000 cps or less at 15°C; (3) the curing agent has a viscosity of 10.000 cps or less at 15°C; 15.000 in
The two-component polyurethane composition for mechanical construction according to claim 1, which has a polyurethane composition of less than cps.

(4) When the urethane prepolymer and the curing agent are mixed, the viscosity at 15°C 92 minutes after the start of mixing is 10.
000 cps or less, the two-component polyurethane composition for mechanical construction according to claim 1.

(5) The polyurethane composition for mechanical construction according to claim 1, which has a pot life of 5 to 20 minutes and a tack-free time of 30 to 90 minutes at the on-site construction temperature.

(6) Urethane with an incyanate group at the end of the molecule.
Prepolymer, molecular weight 1,000-s, oo.

A fast-curing two-component polyurethane composition for mechanical construction, which contains a long-chain polyol, an aromatic amine, a urethanization catalyst, and a heat-resistant stabilizer as essential components, is mixed in a static mixer or a dynamic mixer. , a mechanical construction method in which this mixed solution is immediately flowed onto the substrate and leveled to form a uniform polyurethane/nidistomer coating.

Incyanates used in the production of the urethane prepolymer used in the present invention include 2,4-tolylene diisocyanate (2,4-TDI), 2,4-TDI and 2,6-tolylene diisocyanate (2,6-TDI ) of 80:20 (
(by weight) mixture, the same <65:35 (by weight) mixture;
4.4'-diphenylmethane diisocyanate, 4.
4'-diphenylmethane diisocyanate and 2,4'-
There are mixtures of diphenylmethane diincyanate, so-called liquid MDI obtained by liquefying these by carbodiimide modification, and polymethylene polyphenylisocyanate.
:20 (by weight) and 65:35 (by weight) mixtures are preferred.

Polyols used in the production of urethane prepolymers include low-molecular glycols such as propylene glycol (PG), dipropylene glycol, tripropylene glycol, and diethylene glycol, and long-chain polyols include various polyether polyols and polyesters [Co., Ltd. ] Polyol, polybutadiene polyol, castor oil, etc. are used, but polyoxyalkylene glycol, glycerin (G), which is obtained by adding propylene oxide (PO) or propylene oxide and ethylene oxide (EO) to water, PG, etc. Particularly preferred are polyoxyalkylene triols obtained by adding PO or PO and EO to methylolpropane (TMP) or the like. The average molecular weight of the polyol is preferably 60 to 8,000. Urethane prepolymers are produced by heating polyisocyanate and polyol at 80 to 100° C. for several hours in a nitrogen stream. The resulting prepolymer has an NC of 3-10% by weight and a viscosity of 1.000-1.0,000 cps/15°C.

In producing the urethane prepolymer, up to 10% by weight of a plasticizer may be added for the purpose of lowering the viscosity.

The long chain polyol used as a curing agent has a molecular weight of 1.000.
-8,000 various polyether polyols, polyester polyols, polybutadiene polyols, etc. are used, but polyoxyalkylene glycols and polyoxyalkylene triols are preferred.

The aromatic amine used in the present invention is 3,3'-dichloro-
4,4'-diaminodiphenylmethane (abbreviated as MOCA), a polyamine mixture in which 2-chloroaniline and aniline are condensed with formaldehyde in the presence of a mineral acid (the molar ratio of 2-chloroaniline and aniline is 1:0.1 ~ sail 35
However, in order to shorten the usable time, diethyl \endiamine (D
ETDA), 3,3'-diethyl-4,4'-diaminodiphenylmethane, 3,3'-diinpropyl-4,4
'The viscosity increases immediately after mixing a highly active amine remer such as monodiaminodiphenylmethane with a curing agent, and
Since the viscosity after 15 minutes exceeds 10,000 cps at 15°C, leveling is poor and it is not suitable for mechanical construction.

As the urethanation catalyst used in the present invention, lead catalysts such as lead octylate and lead naphthenate, acid catalysts such as adipic acid, octylic acid, and naphthenic acid, and diazabicycloundecene are used in combination. The amount used is 1 to 10 parts per 100 parts of the curing agent (in the present invention, parts represent parts by weight).

The heat-resistant stabilizers used in the present invention include hindered phenol-based stabilizers such as Tsukura N5-6, metal chelates such as Tsukurak MBC, and Tsukura TT.

Thiuram series such as Tsukusera TET, Tsukusera TTCU
Dithioic acids such as (manufactured by Daien Shinko Chemical), Chele
x Dialkyl hydrogen phosphonates such as H-8 and Chelex H-12 (manufactured by Sakai Chemical Co., Ltd.) are used alone or in combination of two or more. The amount used is 0.5 to 5 parts per 100 parts of the curing agent.

As the plasticizer used in the present invention, DOP% DOA, chlorinated Norahuin, Neelex 170 (manufactured by Tokyo Jushi), etc., which are commonly used for polyurethane, are used. The amount of plasticizer used is 1S part or less per 100 parts of the total of prepolymer and curing agent.

Fillers include calcium carbonate, clay, talc, silica, carbon black, and the like, and colorants include inorganic pigments such as red iron oxide and chromium oxide, and organic pigments such as azo pigments and phthalocyanine pigments.

As the antifoaming agent, silicone-based antifoaming agents, polyacrylic acid ester-based antifoaming agents, etc., which are commonly used for polyurethane, can be used. The amount of antifoaming agent used is 0.5 to 100 parts of hardening agent.
There are 3 parts.

Further, in order to lower the viscosity of the urethane prepolymer and curing agent, a solvent may be added in an amount not exceeding 10% by weight based on the entire polyurethane elastomer composition.

The solvents that can be used are mainly aliphatic hydrocarbon solvents, aromatic hydrocarbon solvents, etc., but ester-based insolvents, ketone insolvents, etc. may also be used depending on the case.

Next, regarding the construction machine used in the present invention, a raw material tank,
It is a combination of a pump, a stirring/mixing section, and a discharge/flow section.

The pump may be either a gear type or a pusher type, but it is preferable that there is no pulsation in the flow rate.

The stirring and mixing section may be either a static mixer or a dynamic mixer, but since the pot life of the materials used is short, a cleaning line that can flush the solvent and clean the stirring and mixing section immediately after discharging is required is required.

Discharge and Flow In part, the ability to uniformly flow the mixed liquid in a ten-like shape in the stirring and mixing section allows for good leveling of the low-viscosity, fast-curing stock solution, and forms a coating film without entrainment of bubbles or air bubbles. Therefore, it has a significant effect.

(Example) The present invention will be explained in more detail with reference to the following example.
It is not limited only to the examples.

Production Example 1 Molecule (i2,000 polyoxypropylene diol 5
In a mixed solution of 40 parts of polyoxypropylene triol with molecule -1i3,000, 240 parts of polyoxypropylene triol, and 45 parts of dioctyl adipate, the isomer ratio of 2.4 and 2,6 is 80/20.
1 to 175 parts of tolylene diisocyanate was added thereto, and the mixture was reacted at 80° C. for 4 hours in a reaction vessel.

The free NCO group content of the obtained prepolymer A was 4.7% by weight, and the viscosity at 15°C was 7,000 cps.

Production Example 2 Polyoxypropylene diol 28 with a molecular weight of 3,000
An aromatic polyamine (2
-Chloroaniline:aniline molar ratio is 1:0.3
3. After heating and dissolving 22 parts of CA), D
OPl, 40 parts, 25% lead octylate solution (trade name "Minico P-25J": Shizai Chemical Co., Ltd.) 40 parts, 2-ethylhexanoic acid 35 parts, di-2-ethylhexylhydrodienphos 7-onate (trade name “Chelex H-
8j: Sakai Chemical), 50 parts of toner, 15 parts of amorphous silica (trade name "Carplex ◆ 80": Shionogi Pharmaceutical) and 350 parts of heavy calcium carbonate were added, and the mixture was uniformly stirred and kneaded using a disilver. Then, curing agent A'
f, got it. O whose viscosity at 15°C was 13.000 cps Production Example 3 Polyoxypropylene diol 28 with a molecular weight of 3.000
After heating and dissolving 45 parts of MOCA, 22 parts of CA, and 7.5 parts of 3,3'-diethyl-4,4'-diaminodiphenylmethane (trade name "Kayahard AAJ: Nippon Kayaku)" in 0 parts, 193.5 parts of DOP, 20 copies of Minico P-25,
12 parts of 2-ethylhexanoic acid, tetraethylthiuram disulfide (trade name Nocrack TET: Shinko Ohmukai)
5 parts of toner, 50 parts of toner, 15 parts of Curblexna 80, and 350 parts of heavy calcium carbonate were added, and the mixture was uniformly stirred and kneaded using a disilver to obtain hardening agent Bf. 1
The viscosity at 5°C was 10,000 cps.

Example 1 (Discharge/flow test in a constant temperature room at 15°C) Prepolymer A and curing agent A were put into the tank of a construction machine, and the liquid temperature was confirmed to be 15°C. After mixing with a mixer (1:1),
Vomited immediately. When the viscosity of the mixed liquid was measured over time, the viscosity after 2 minutes of discharge was 8,300 cps, 18
100,000 cps was reached after minutes.

Furthermore, the surface of the cured product became tack-free after 75 minutes.

When the mixed solution mixed in a part of the mixer flowed in a curtain shape through the slits onto a slate plate treated with a primer, it was leveled and a smooth, bubble-free coating film was obtained.

A similar test was also conducted using curing agent B.

The viscosity after 2 minutes of discharge was 9.500 cps, and reached 100.000 cps after 19 minutes. After 80 minutes, the surface of the cured product became tack-free. When it was similarly flowed onto a slate board, it leveled and a smooth coating film with no bubbles was obtained.

In this way, in a mechanical construction test in a constant temperature room, we used a low-viscosity prepolymer and curing agent, and the pot life was 20.
It exhibited good paintability, with a tack-free time of less than 90 minutes.

Example 2 (Discharge/flow test in a normal laboratory) Using prepolymer and curing agent A, Example 1 was carried out in a normal laboratory.
A similar test was conducted.

The temperature of both solutions was 25°C. After mixing with a portion of the two-liquid mixer, the mixture was immediately discharged. Viscosity after 2 minutes of discharge is 6.60
0 cps and reached Zoo, 000 cps after 9 minutes. Furthermore, after 40 minutes, the surface of the cured product became tack-free.

Similarly, when the mixed solution mixed in a part of the mixer was flowed onto a primer-treated slate board, it was leveled and a smooth coating film without bubbles was obtained.

A similar test was conducted using Curing Agent B. The viscosity after 2 minutes of discharge was 5,400 cps, and after 10 minutes it was 1,00 cps.
．． 000 cps K reached. The surface of the cured product became tack-free after 50 minutes.

When it was similarly flowed onto a slate board, it leveled and a smooth coating film with no bubbles was obtained.

Example 3 During a discharge/flow test in a normal laboratory, a foamed polyethylene back-up material for sealing material flowed onto a polypropylene plate with a gap around it, and the film thickness was approximately 3 mm.
A cured product sheet was prepared.

The normal physical properties and the physical properties after the heat resistance test of the obtained sheet are shown in Table 1. As shown in Table 1, both the normal physical properties and the retention of physical properties after the heat resistance test were very good, and almost no thermal deterioration was observed despite the large amount of catalyst.

= 17 - (Effects of the Invention) The two-component elastomer of the present invention has excellent paintability and appearance of the coating film when mechanically applied, and both normal physical properties and physical property retention after heat resistance test are very excellent.

Claims (6)

[Claims] (1) Urethane with isocyanate group at the end of the molecule
The essential components are a prepolymer, a long-chain polyol with a molecular weight of 1,000 to 8,000, an aromatic amine, a urethanization catalyst, and a heat-resistant stabilizer, and if necessary, a plasticizer, filler, colorant, and antifoaming agent. A low-viscosity, fast-curing two-component polyurethane composition for mechanical construction comprising a curing agent uniformly kneaded with other auxiliary agents. (2) Claim 1, wherein the urethane prepolymer has a viscosity of 10,000 cps or less at 15°C.
A two-component polyurethane composition for mechanical construction as described in 2. (3) The viscosity of the curing agent is 15,000 at 15°C.
The two-component polyurethane composition for mechanical construction according to claim 1, which has a polyurethane composition of less than cps. (4) When the urethane prepolymer and the curing agent are mixed, the viscosity after 2 minutes from the start of mixing is 10,
The two-component polyurethane composition for mechanical construction according to claim 1, which has a polyurethane composition of 000 cps or less. (5) The polyurethane composition for mechanical construction according to claim 1, which has a pot life of 5 to 20 minutes and a tack-free time of 30 to 90 minutes at the on-site construction temperature. (6) Urethane having an isocyanate group at the end of the molecule;
The essential components are a prepolymer, a long-chain polyol with a molecular weight of 1,000 to 8,000, an aromatic amine, a urethanization catalyst, and a heat stabilizer, and if necessary, a plasticizer, filler, colorant, antifoaming agent, etc. A low-viscosity, fast-curing, two-component polyurethane composition for mechanical construction, consisting of a curing agent made by uniformly kneading auxiliary agents, is prepared using a static mixer or a dynamic mixer. A mechanical construction method in which the mixture is mixed in a mixer and immediately flowed onto the substrate, leveling it and forming a uniform polyurethane/elastomer coating.