JPH07268050A - Production of rapidly curing sprayable elastomer - Google Patents

Abstract

PURPOSE:To provide a process for producing a polyurethane elastomer with physical properties suitable for a rapidly curing waterproof material by using specific materials, a specific formulation, and a specific apparatus. CONSTITUTION:A liq. component which mainly comprises a modified polytetramethylene glycol which is liq. at normal temp. and has a number- average mol.wt. of 500-5,000 and contains an arom. polyamine crosslinker and an organometal catalyst is reacted with a liq. component contg. an org. polyisocyanate in an equivalent ratio of NCO to active hydrogen of 0.9-1.4 using a two-component high-pressure-mixing spray unit. The modified polytetramethylene glycol, flowable at normal temp., is a copolymer of tetrahydrofuran with an aklylated tetrahydrofuran and is produced by, e.g. copolymerizing tetrahydrofuran with a 3-aklyltetrahydrofuran in a molar ratio of pref. (85/15) to (20/80).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a fast-curing polyurethane waterproof material using a two-liquid high-pressure mixing type spray device.

[0002]

2. Description of the Related Art Polyurethane waterproofing materials are often used for rooftop waterproofing applications. Usually coated with a rubber spatula or the like, but to improve workability, a polyoxyalkylene polyol (hereinafter referred to as PPG) obtained by ring-opening polymerization of ethylene oxide or propylene oxide as a main component, and an aromatic amine cross-linking agent. And A containing an organometallic catalyst
A system in which a liquid and a liquid B containing an organic polyisocyanate are sprayed using a high-pressure mixing type sprayer has been developed (Japanese Patent Laid-Open No. 61-24772).
1). Further, a system using polytetramethylene glycol (hereinafter referred to as PTMG) in the liquid A has been developed for the purpose of improving physical properties (Japanese Patent Laid-Open No. 2-25887).
7).

[0003]

However, since products using the conventional PPG system have poor oil resistance, cold resistance, and water resistance, they are suitable for factory floors that use a lot of oil, general floors in cold regions, and waterproof applications. Was unsuitable. Also, PTMG
Is a solid at room temperature in most cases, and even when it is in a molten state, it is likely to partially crystallize due to changes in the outside temperature, resulting in poor mixing with liquid B by a sprayer, reactivity variation, deterioration of coating surface property, deterioration of physical properties, etc. The fact is that it is not suitable for waterproof materials and is not used because of its drawbacks.

[0004] The waterproof material is required to have higher mechanical properties and extensibility because it requires crack followability of concrete in particular. In addition, the conventional products are lacking in water resistance, which is a problem in actual use.

[0005]

Means for Solving the Problems As a result of various studies, the inventors of the present invention produced the elastomer by using a specific modified polytetramethylene glycol as a main component and using a specific compounding recipe and a specific apparatus. Could be solved. That is, the present invention has a number average molecular weight of 500 to 500.
It is 0, and liquid A at room temperature contains modified polytetramethylene glycol as a main component, liquid A containing an aromatic polyamine crosslinking agent and an organic metal catalyst, and liquid B containing an organic polyisocyanate in an equivalent ratio (NCO / activity). Hydrogen) 0.9
The present invention provides a method for producing a polyurethane elastomer, which comprises mixing and reacting with a two-liquid high-pressure mixing type spraying device so that the amount becomes to 1.4.

The details will be described below. Ordinary polytetramethylene glycol (PTMG) is a homopolyol obtained by ring-opening polymerization of tetrahydrofuran, but with a number average molecular weight of 500 to 5000, the melting point is in the range of 20 to 40 ° C, at room temperature or At higher temperatures, crystallization will occur.

However, the modified PTMG according to the present invention is
Since it has an alkyl group (having 1 to 4 carbon atoms) in its side chain, even if it has a number average molecular weight of 500 to 5000, its melting point is at or below 10 ° C and is at room temperature (25 ° C).
Then, it is in a completely liquid state.

The "modified polytetramethylene glycol which is liquid at room temperature" used in the present invention is a copolymer of tetrahydrofuran and an alkyl-substituted tetrahydrofuran and has fluidity at room temperature. For example, it can be produced by copolymerizing tetrahydrofuran and 3-alkyltetrahydrofuran at a mixing ratio of preferably 85/15 to 20/80 in molar ratio. In this case, if the molar ratio of 3-alkyltetrahydrofuran is less than 15, the crystallinity increases and the liquid cannot be liquefied at room temperature. Also, when the molar ratio of 100 exceeds 80,
The desired mechanical properties cannot be obtained. The modified polytetramethylene glycol has a number average molecular weight of 500 to 5,000 and can be varied over a wide range depending on the intended use, and particularly preferably 800 to 3,000. When the number average molecular weight is lower than 500, the resulting elastomer becomes too hard and lacks extensibility. On the other hand, when the number average molecular weight is higher than 5,000, the viscosity of the liquid A becomes too high and spraying becomes impossible, and both are not suitable for waterproof material applications. This modified polytetramethylene glycol and ordinary polytetramethylene glycol can be used in combination. Due to the liquidity of the liquid A, the combination ratio can be 1: 0 to 1: 1 (weight ratio).

The aromatic polyamine as the cross-linking agent contained in the solution A of the present invention includes 2,4- and 2,6-diaminotoluene (containing a mixture of 80/20 parts by weight), 2,4'- and 4, Four'
-Diaminodiphenylmethane, polyphenylpolymethylene polyamine obtained by aniline formaldehyde condensation, 1,3-dimethyl-2,4-diaminobenzene, 1,
3-diethyl-2,6-diaminobenzene, 1-methyl-
3,5-diethyl-2,4-diaminobenzene, 1-methyl-3,5-diethyl-2,6-diaminobenzene, 3,3 ′, 5,
5'-tetramethyl-4,4'-diaminodiphenylmethane,
3,3 ', 5,5'-tetraethyl-4,4'-diaminodiphenylmethane, 3,3', 5,5'-tetraisopropyl-4,4'-diaminodiphenylmethane, and the like, and mixtures thereof. A preferred aromatic polyamine is one in which an alkyl group is substituted at the ortho position of the amino group, and particularly 1
A mixture of -methyl-3,5-diethyl-2,4-diaminobenzene and 1-methyl-3,5-diethyl-2,6-diaminobenzene is preferred. The amount used is 5 with respect to the total weight of liquid A
~ 30% by weight. In order to obtain the performance required for waterproof material applications and the like, 10 to 25% by weight is preferable.

As the organometallic catalyst used in the present invention, a known catalyst that promotes the urethanization and urea formation reactions can be used. Examples thereof include tin octylate, dibutyltin dilaurate, lead octylate, and lead naphthenate. These organometallic catalysts are used alone or in combination. The amount used is 0.01 of the total weight of solution A.
Is in the range of up to 5% by weight.

In the present invention, a known amine catalyst which promotes urethanization in combination with an organic metal catalyst can be used. Examples of amine catalysts include triethylenediamine,
Examples thereof include N-methylmorpholine and N-methyldicyclohexylamine. The amount used is 0.0 of the total amount of liquid A.
It is in the range of 1 to 5% by weight.

The organic polyisocyanate of the liquid B used in the present invention includes 2,4- and 2,6-tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate, xylylene diisocyanate. , Dicyclohexylmethane-4,4 '
-Diisocyanate, isophorone diisocyanate, hexamethylene diisocyanate, carbodiimide modified products of these diisocyanates, isocyanurate modified products,
Examples include buret modified products, and partial prepolymers of these diisocyanates with polyols and their modified products. Further, polymethylene polyphenylene isocyanate can also be mixed and used.

The polyol used for producing the partial prepolymer of isocyanate includes water, ethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, glycerin, trimethylolpropane, pentaerythritol, and other polyhydric alcohols, and propylene. There are polyether polyols obtained by addition polymerization of oxide alone or propylene oxide and ethylene oxide, and in addition, polycaprolactone polyol, PTMG, modified PTM.
G, castor oil and the like. The polyether polyol having a molecular weight of 500 to 10,000 can be used, and a preferable molecular weight is 1,000 to 5,000.

These polyisocyanates can be used alone or in admixture of two or more. The preferred organic polyisocyanate is 4,4′-diphenylmethane diisocyanate, 2,4′-diphenylmethane diisocyanate, or a partial prepolymer of a carbodiimide-modified polyol thereof.

Other auxiliaries used in the present invention are plasticizers, stabilizers, flame retardants, colorants and the like.

Examples of the plasticizer include dioctyl phthalate (DOP), dioctyl adipate (DOA),
Examples include dibutyl phthalate (DBP), tricresyl phosphate (TCP), and chlorinated paraffin. The amount used is preferably 5 to 10% by weight of the resin component. Here, the resin component refers to all components including liquid A, liquid B, and an auxiliary agent (the same applies in the following description).

As the stabilizer, SANOL LS-770 is used.
(Manufactured by Ciba Geigy), hindered amine-based light stabilizer, tinuvin P-327 (manufactured by Ciba Geigy), benzotriazole-based UV absorber, Irganox 10
10, 1070 (made by Ciba Geigy), Yoshinox BH
A hindered phenolic antioxidant such as T (manufactured by Yoshitomi Pharmaceutical Co., Ltd.) is used. The amount of the resin component
0.1 to 2% by weight is preferable.

Examples of the flame retardant include halogen-containing phosphates such as tris (β-chloropropyl) phosphate, tris-dichloropropylphosphate and tris-chloroethylphosphate. The amount used is preferably 5 to 15% by weight of the resin component.

As the colorant, an organic or inorganic pigment kneaded with the above plasticizer can be used.

The mixing ratio of the liquid A and the liquid B is equivalent ratio (NC
O / active hydrogen) is preferably 0.9 to 1.4, and if the equivalent ratio is less than 0.9, the curability becomes slower, and 1.4
Above, the coating film becomes brittle and the original performance for waterproofing is not exhibited.

A two-liquid high-pressure mixing type spraying device which can be used in the present invention has, for example, a main body made of Gasmer's model H-2000, and 100 kg of two liquids A liquid / B liquid.
The liquid can be metered and delivered at a pressure of / cm ² or more. As a spray gun for mixing the two liquids and spraying them on the object to be coated, it is preferable to use GY-7 gun, AR-A gun manufactured by Gasmer, Probler gun manufactured by Grasscraft, or the like. Solution A and solution B are each heated through a hose heater, and solution A is adjusted to 40-60 ° C and solution B is adjusted to 30-50 ° C.
Mix and spray. In the present invention, it is possible to perform thick coating by spraying once or to continuously laminate in a shorter time. Since the polyurethane elastomer according to the present invention has high reactivity after spraying, a uniform elastomer can be formed within a few seconds to a few minutes.

EXAMPLES The present invention will be specifically described below with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples. The symbols used in the examples and comparative examples have the following meanings.

PTGL-1000: Modified PTMG in liquid form at room temperature, number average molecular weight = 1000 (Hodogaya Chemical Co., Ltd.), 3-methyl THF unit = 16% content,
Melting point range about 5 to 7 ° C. PTGL-3000: Modified PT that is liquid at room temperature
MG, number average molecular weight = 3000 (manufactured by Hodogaya Chemical Co., Ltd.),
3-Methyl THF unit = 16% contained, melting point range about 8 ~
10 ° C. CM-111: Polyoxypropylene oxyethylene glycol, number average molecular weight = 1000 (manufactured by Asahi Denka) PTG-1000: Normal polytetramethylene glycol, number average molecular weight = 1000 (manufactured by Hodogaya Chemical Industry Co., Ltd.), melting point range of about 18 to 22 ° C. PTG-3000: normal polytetramethylene glycol, number average molecular weight = 3000 (manufactured by Hodogaya Chemical Co., Ltd.), melting point range about 38 to 42 ° C. DETDA: a mixture of 1-methyl-3,5-diethyl-2,4-diaminobenzene and 1-methyl-3,5-diethyl-2,6-diaminobenzene (manufactured by Ethyl Corporation) DBTDL: dibutyltin dilaurate catalyst ( Katsuta Chemical Co., Ltd.) Millionate MT: 4,4'-diphenylmethane diisocyanate (Nippon Polyurethane Industry Co., Ltd.) Coronate MTL: Carbodiimide modified liquid diphenylmethane diisocyanate (Nippon Polyurethane Industry Co., Ltd.) Sannix PP-3000: Number average molecular weight about 3000
Polyoxypropylene glycol (manufactured by Sanyo Kasei Co., Ltd.) Phylol PCF: Tris (β-chloropropyl) phosphate (manufactured by Akzo Japan) Moldability: i) Sprayability ………… Good or bad of spray pattern on coated object ii) State of coating film ... Formation of coating film immediately after spraying, surface condition iii) Tack-free ... Drying time of coating film immediately after spraying Oil resistance: Test piece (2 mm thick sheet) for 1 week in soybean oil or lubricating oil Appearance evaluation after dipping. Elongation after deterioration treatment: Elongation measured at 25 ° C after standing under each condition. i) Heat resistance 80 ° C. × 10 days later ii) Water resistance 40 ° C. warm water × 10 days later iii) Cold resistance −20 ° C. × 10 days later

Preparation of spray liquid Preparation of liquid A As the main component of liquid A, PTGL-1000, PTGL-
The components shown in Table 1 from 3000 and PTG-1000, the polyamine DETDA, and the catalyst DBTDL were uniformly mixed according to the formulation of Table 1, to prepare a liquid A.

Preparation of Solution B Millionate MT and Coronate MTL were charged in a 200-liter reaction kettle according to the formulation shown in Table 1 and supplied under a nitrogen stream to Sannicks PP-3000 or PTGL-3000.
Is gradually added, and the mixture is heated and stirred at 80 ° C. for 3 hours to complete the reaction and produce a partial prepolymer.
Solution F was added to prepare solution B.

Examples 1 to 6 Liquids A and B were filled in drums, respectively, heated by a drum heater, and model H-2000 was supplied by a supply pump.
(Gasmer Co.) was used to adjust the liquid temperature while circulating. The temperature of the liquid at this time was adjusted by setting the heat exchanger of the model H-2000 of the main body to A liquid 60 ° C. and liquid B 50 ° C., and setting the hose heater current to 5 A. The volume ratio of the liquid A and the liquid B is 1: 0.88 to 1: 1.10 (equivalent ratio 1: 1.00).
˜1: 1.25). Spray gun
Using a glass craft's Probler gun, the nozzle tip is NO. 01 was attached. The object to be coated is 300 mm ×
A 300 mm aluminum plate was used and sprayed to a film thickness of 1.5-2 mm. The moldability of the coating film is as shown in Table 1, and a good coating film was obtained. The sheets obtained are 2
After curing for 1 week in a thermostatic chamber at 5 ° C., the physical properties were measured according to JIS A-6021, and the oil resistance and elongation after deterioration treatment were measured. The results are as shown in Table 1.

Example 7 As liquid A, Coronate MT was used instead of the partial prepolymer.
Using L, the liquid ratio of liquid A and liquid B was 2: 1 (equivalent ratio 1: 1.1).
It implemented like Example 1-6 except having set it as 4).
The results are also shown in Table 1.

[0028]

[Table 1]

Comparative Examples 1-3 Instead of PTGL-1000 and PTGL-3000, CM-111, PTG-1000 and PTG-3000 were uniformly mixed in accordance with the formulation shown in Table 1 to prepare solution A. A polyurethane elastomer was produced according to the procedures described in 1 to 6, a coating film was formed, and the moldability, physical properties, oil resistance, and elongation after deterioration treatment of the coating film were measured. The results are shown in Table 2.

In Comparative Examples 2 and 3, although the temperature of the liquid A was raised to 65 ° C. because the viscosity of the liquid A was high, the spray pattern (atomization) was poor and a uniform coating film could not be obtained. In Comparative Example 3, the mixability was particularly poor, and an uncured portion was also recognized, so that the sheet was not formed.

Comparative Examples 4 and 5 Liquid modified PTMG, number average molecular weight 450 (manufactured by Hodogaya Chemical Industry Co., Ltd.), liquid modified PTMG, number average molecular weight 6
000 (Hodogaya Chemical Co., Ltd.) and polyamine DETDA
And the catalyst DBTDL were uniformly mixed in accordance with the formulation of Table 1 to prepare the liquid A, and an attempt was made to produce a polyurethane elastomer according to the procedure described in Examples 1 to 6. In Comparative Example 4, a coating film was formed and the moldability, physical properties, oil resistance, and elongation after deterioration treatment of the coating film were measured. The results are shown in Table 2. In Comparative Example 5, the mixing property was poor, and an uncured portion was also recognized, and the sheet could not be formed.

[0032]

[Table 2]

[0033]

As shown in Table 1, the modified P which is liquid at room temperature
By using TMG, it is possible to secure physical properties suitable for waterproof material applications, in particular, an elongation rate of 450% or more even after deterioration treatment.

Further, since the modified PTMG used in the present invention is liquid at normal temperature, there is no problem of deterioration of physical properties and surface property of the product due to poor mixing, and the modified PTMG derived from 3-alkyl-substituted tetrahydrofuran is Since both ends have primary hydroxyl groups, the product can be highly reactive and excellent in processability.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kiyofumi Murayama 3007-1 Minamishitaura-cho, Umimiyata, Miura City, Kanagawa Prefecture (72) Akira Ishii 7-43 Daikokucho, Tsurumi-ku, Yokohama City, Kanagawa Hodogaya Chemical Co., Ltd. Company Tsurumi factory

Claims (2)

[Claims] 1. A liquid containing a modified polytetramethylene glycol as a main component, which has a number average molecular weight of 500 to 5000 and is liquid at room temperature, and which contains an aromatic polyamine crosslinking agent and an organic metal catalyst, and an organic polyisocyanate. A method for producing a polyurethane elastomer, which comprises mixing and reacting the contained liquid B with an equivalence ratio (NCO / active hydrogen) of 0.9 to 1.4 using a two-liquid high-pressure mixing type spray device. 2. The method according to claim 1, wherein the modified polytetramethylene glycol which is liquid at room temperature is obtained by copolymerizing tetrahydrofuran and alkyltetrahydrofuran.