JPH06157700A - Urethane composition - Google Patents

Abstract

PURPOSE:To obtain an NCO-terminated urethane prepolymer which can form in situ a high-strength cured urethane product in all seasons by mixing a specified polyol with a specified isocyanate in a specified equivalent ratio. CONSTITUTION:This urethane composition is prepared by reacting a polyol comprising a polytetramethylene ether glycol having a number-average molecular weight of 850 or below and a weight-average molecular weight to number- average molecular weight ratio of 1.8 or below with an isocyanate comprising tolylene diisocyanate in an equivalent ratio of the OH groups to the NCO groups of 1:1.7 to 1:2.2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high-strength urethane composition which can be used for a full year and is used as a waterproofing agent for coating films, floor coating materials, paving agents, sealing materials and the like.

[0002]

2. Description of the Related Art Conventional urethane compositions used at room temperature for coating film waterproofing agents, floor coverings, paving materials, etc.
Polyol such as polypropylene ether glucurol or triol, and tolylene diisocyanate (TD
The isocyanate-terminated urethane prepolymer, which is a reaction product with an aromatic diisocyanate such as I), is used as an isocyanate component (component A) and is reacted with an isocyanate such as glycols, polypropylene ether glycol or triol, polycaprolactone polyol, and aromatic polyamine. A high solid two-component urethane composition in which an active hydrogen compound is used as a curing agent (component B), components A and B are mixed at a construction site, and the mixture is cast onto an object to be coated and cured at room temperature. Was the main subject.

TDI is usually used as a raw material isocyanate for the production of this isocyanate-terminated urethane prepolymer (component A), but when diphenylmethane diisocyanate (MDI) is used, the viscosity of the prepolymer is high, and TDI is used. This is because the reactivity is large and inconvenience is likely to occur in the work.

As a polyol which is one of the raw materials for producing the component A or as a polyol which is the component B,
It is possible to use polytetramethylene ether glycol (PTMG), but since PTMG itself crystallizes at room temperature to low temperature, it is inconvenient as a curing agent (component B), and this is used for producing component A. When used as the starting material polyol, the isocyanate-terminated urethane prepolymer, which is a reaction product of PTMG and TDI, is solidified in the winter and causes inconvenience in on-site construction. When such components A and B are heated, the crystals once precipitated melt, but in the field of the present invention, it is important to carry out the construction at the ambient temperature even in winter (low temperature), and it is difficult to heat them on site. Is.

Therefore, isocyanate-terminated urethane prepolymers using PTMG and TDI have hitherto been used in the fields of coating film waterproofing agents, coated flooring materials, paving materials, etc., in which construction during the entire period (normal temperature to low temperature) of the present invention is important. Was considered impossible.

[0006]

SUMMARY OF THE INVENTION In order to solve the above problems associated with the use of PTMG, the present invention uses PTMG and PTMG which do not crystallize even at low temperatures.
Isocyanate-terminated urethane prepolymers made from polypropylene ether polyols composed of conventional polypropylene ether polyol and TDI are produced by producing an isocyanate-terminated urethane prepolymer containing It is an object of the present invention to provide a urethane composition which gives a cured product having higher strength than a urethane composition comprising a polymer and a curing agent.

[0007]

DISCLOSURE OF THE INVENTION The present inventors have selected PTMG having a number average molecular weight of 850 or less and a ratio of the weight average molecular weight to the number average molecular weight of 1.8 or less and TDI as a hydroxyl group and an isocyanate. The equivalent ratio of the groups is 1: 1.7 to 1 :.
By reacting in 2.2, the amount of solvent used is 10
%, The isocyanate-terminated urethane prepolymer that does not crystallize even when stored at 0 ° C even when it is stored at 0% (weight) or less can be used as an isocyanate component, so that there is no hindrance to work at ambient temperatures even in winter. ,
It has also been found that the physical properties of the cured coating film give higher tensile strength, higher tear strength, higher abrasion resistance, and higher weather resistance than when using conventional polypropylene ether polyol.

That is, the present invention is as follows. In the urethane prepolymer composed of polyol and isocyanate, the polyol has a number average molecular weight of 8
Polytetramethylene ether glycol (PTMG) having a ratio of weight average molecular weight to number average molecular weight of 50 or less (weight average molecular weight / number average molecular weight) of 1.8 or less, and the isocyanate is tolylene diisocyanate (T
DI), and an isocyanate-terminated urethane prepolymer having an equivalent ratio of hydroxyl groups to isocyanate groups of 1: 1.7 to 1: 2.2. A two-component urethane resin composition comprising the isocyanate-terminated urethane prepolymer and a curing agent.

The PTMG used in the present invention must have an average molecular weight of 850 or less and a ratio of the weight average molecular weight to the number average molecular weight (weight average molecular weight / number average molecular weight) of 1.8 or less. When the number average molecular weight is 850 or more, the isocyanate-terminated urethane prepolymer composed of PTMG and TDI is crystallized at a low temperature even if the ratio of the weight average molecular weight to the number average molecular weight is 1.8 or less.

TDI used in the isocyanate-terminated urethane prepolymer of the present invention has a ratio (weight ratio) of tolylene-2,4-diisocyanate alone or tolylene-2,4-diisocyanate to tolylene-2,6-diisocyanate. It is a mixture of 80:20 or 65:35.

To produce an isocyanate-terminated urethane prepolymer by reacting PTMG with TDI, PTM is used.
It is charged so that the equivalent ratio of the hydroxyl group of G and the isocyanate group of TDI is in the range of 1: 1.7 to 1: 2.2. If this ratio is 1.7 or less, the viscosity of the urethane prepolymer produced by the reaction becomes too high, and if it is 2.2 or more, the amount of unreacted free TDI remaining after the reaction becomes too large. However, inconvenience occurs during the full-time construction of the present invention.

Isocyanate-terminated urethane prepolymers include TDI and PTMG used in the present invention at a ratio of an equivalent ratio of a hydroxyl group to an isocyanate group of 1: 1.7 to 1: 2.2 in a nitrogen stream at 40 to 90 ° C. Produce by heating for an hour.

An isocyanate-terminated urethane prepolymer of PTMG and TDI of the present invention is used as an isocyanate component (A component), and a polyol and / or an aromatic polyamine cross-linking agent, if necessary, a plasticizer, a filler, and a curing accelerator. A high-strength waterproof material by using a curing agent containing a coloring agent, etc. as the component B, mixing a predetermined amount of the component A and the component B on site, and casting or spraying and curing the mixture on an object to be coated. , Flooring materials, paving materials, sealing materials, etc. can be formed by construction throughout the period (normal temperature or low temperature).

The polyol contained in the curing agent (component B) used in the present invention includes glycols such as ethylene glycol and propylene glycol, and a molecular weight of 400 to 600.
Specific examples of the various polyols of No. 0 are polypropylene ether glycol or triol, polyester polyol, polycaprolactone polyol, polybutadiene polyol, polyacryl polyol, polyethylene-polypropylene ether polyol, and polymer polyol obtained by graft-polymerizing acrylonitrile, styrene and the like. , Castor oil, etc.

The aromatic polyamine crosslinking agent contained in the curing agent (component B) used in the present invention is 3,3'-dichloro-4,4'-diaminodiphenylmethane (MOC).
Ortho-chloroaniline-formalin condensate represented by A), 4,4'-methylene-bis- (3-chloro-
2,6-diethylaniline), 3,5-dimethylthio-
A mixture of 2,4-toluenediamine and 3,5-dimethylthio-2,6-toluenediamine, 2,2 ', 3
Examples include 3'-tetrachloro-4,4'-diaminodiphenylmethane. These aromatic polyamines are
Except for the mixture of 3,5-dimethylthio-2,4-toluenediamine and 3,5-dimethylthio-2,6-toluenediamine, most of them are solid at room temperature, so they are included in the curing agent (component B) in advance. It is used by dissolving it in a polyol or a plasticizer. Water can be used as a cross-linking agent in addition to the aromatic polyamine. When using water, it is necessary to use carbon dioxide absorbents such as slaked lime and cement together.

The plasticizer contained in the curing agent (component B) used in the present invention includes dioctyl phthalate, dibutyl phthalate, dioctyl adipate, tricresyl phosphate, and
Butyl phthalate phthalate, chlorinated paraffin, coal tar, etc. are used. The compounding amount is 2 to 80% by weight, preferably 10 to 50% by weight in the curing agent (component B).
Is.

As the filler contained in the curing agent (component B) used in the present invention, carbon black, calcium carbonate, talc, kaolin, zeolite, silica gel, glass fiber and the like are used. The blending amount thereof is 80% by weight or less, preferably 60% by weight or less in the curing agent (component B).

The curing accelerator contained in the curing agent (component B) used in the present invention includes tin octoate, tin 2-ethylhexoate, tin maleate, dibutyltin dilaurate, lead octoate, tin 2-ethylhexo. Organocatalysts such as lead, naphthenate, bismuth octoate, bismuth neodecanoate, triethylamine, N-
Tertiary amines such as methylmorpholine, teramethylethylenediamine and triethylenediamine are used.
The blending amount is 10% by weight or less in the curing agent (component B),
It is preferably 3% by weight or less.

The isocyanate-terminated urethane prepolymer of PTMG and TDI of the present invention is used as the component A, and the above-mentioned polyol and / or aromatic polyamine, a cross-linking agent, a plasticizer, a filler, a colorant, and, if necessary, a curing accelerator. A curing agent obtained by adding and kneading agents, stabilizers and the like is used as the component B, and the equivalent ratio of total active hydrogen, which is the total of the isocyanate groups in the component A and the hydroxyl groups and / or amino groups in the component B, is 0. The component A and the component B are mixed so as to be 9 to 1.4, preferably 1.0 to 1.2, and are cast-coated by a spatula, a trowel, or a roll brush, or by air spray or the like. Spray coating and curing under ambient conditions provides higher strength and abrasion resistance than conventional polypropylene ether polyol and prepolymers derived from TDI. Sex good waterproofing agents, coating flooring,
Pavement materials, sealing materials, etc. can be formed during the entire period (normal temperature or low temperature).

Even when used as a one-part moisture-curable paint, binder, adhesive or the like for curing the isocyanate-terminated urethane prepolymer obtained from PTMG and TDI of the present invention with atmospheric moisture, it can be used as a normal polypropylene ether polyol. It shows better cured physical properties than using the prepolymer obtained from TDI.

[0021]

The present invention will be described with reference to the following examples. Examples 1 to 4, Comparative Examples 1 to 7 Polytetramethylene ether glycol (PTMEG) whose ratio of the weight average molecular weight to the number average molecular weight and the number average molecular weight are shown in Table 1, 2,4-body and 2,6- The isomer ratio of the body is 80/20, and the equivalent ratio with tolylene diisocyanate is adjusted to 1: 2.
The reaction was carried out at 0 ° C for 3 hours. The obtained isocyanate-terminated urethane prepolymer was diluted with xylene so that the resin content was 95% by weight, and the crystallinity was examined under storage at 0 ° C.

[0022]

[Table 1]

Evaluation method: A crystal does not crystallize after storage at 0 ° C. for 1 month. ×: Crystallized after storage at 0 ° C for 1 month. In Table 1, Mn and Mw are the number average molecular weight and weight average molecular weight of PTG. Mw / Mn is a value obtained by dividing the weight average molecular weight by the number average molecular weight. The isocyanate-terminated urethane prepolymer of Comparative Example 7 was diluted with xylene to a resin content of 90% by weight, and crystallization under storage at 0 ° C. could not be prevented. As seen in Comparative Examples 3 and 4 above, even if the number average molecular weight is 850 or less, if the ratio of the weight average molecular weight to the number average molecular weight exceeds 1.8, the isocyanate-terminated urethane prepolymer is 0 ° C. Crystallize. When the number average molecular weight is 850 or more as seen in Comparative Examples 5, 6, and 7, the prepolymer crystallizes at 0 ° C. even if the ratio of the weight average molecular weight to the number average molecular weight is 1.8 or less.

Preparation Example 1 35 parts of polypropylene ether glycol having a number average molecular weight of 2000, 2 parts of lead octoate, 18 parts of dioctyl phthalate and orthochloroaniline-formalin condensate "Brand name: Bisamine" (manufactured by Wakayama Seika Co., Ltd.) 45 parts Was mixed to obtain a curing agent 1.

Preparation Example 2 30 parts of polypropylene ether triol having a number average molecular weight of 3000, 2 parts of lead octoate, 14 parts of dioctyl phthalate and orthochloroaniline-formalin condensate "trade name: bisamine" (manufactured by Wakayama Seika) 21 parts And 30 parts of calcium carbonate and 3 parts of a green pigment were mixed to prepare a curing agent 2.

Example 5 Isocyanate-terminated urethane prepolymer of Example 1 (designated as urethane prepolymer A) (NCO content 6.7)
%) And curing agent 1 of Preparation Example 1 (isocyanate group):
The urethane composition was obtained by mixing so that the equivalent ratio of (hydroxyl group + amino group) was 1.15: 1.

Example 6 Isocyanate-terminated urethane prepolymer of Example 4 (designated as urethane prepolymer B) (NCO content 8.0)
%) And curing agent 1 of Preparation Example 1 (isocyanate group):
The urethane composition was obtained by mixing so that the equivalent ratio of (hydroxyl group + amino group) was 1.15: 1.

Example 7 The urethane prepolymer A of Example 1 and the curing agent 2 of Preparation Example 2 were mixed so that the equivalent ratio of (isocyanate group) :( hydroxyl group + amino group) was 1.15: 1, A urethane composition was obtained.

Example 8 The urethane prepolymer B of Example 4 and the curing agent 2 of Preparation Example 2 were mixed so that the equivalent ratio of (isocyanate group) :( hydroxyl group + amino group) was 1.15: 1, A urethane composition was obtained.

Comparative Example 8 Polypropylene ether glycol (PPG) having a number average molecular weight of 700 and the isomer ratio of 2,4-isomer and 2,6-isomer was 80 /
The tolylene diisocyanate of 20 was charged so that the equivalent ratio was 1: 2, and reacted at 70 to 90 ° C. for 3 hours in a reaction vessel to produce an isocyanate-terminated urethane prepolymer composed of PPG and TDI (referred to as prepolymer C). did. Isocyanate-terminated urethane prepolymer C described above
And the curing agent 1 mixed in Preparation Example 1 were mixed so that the equivalent ratio of (isocyanate group) :( hydroxyl group + amino group) was 1.15: 1 to obtain a urethane composition.

Comparative Example 9 The isocyanate-terminated urethane prepolymer C prepared in Comparative Example 8 and the curing agent 2 prepared in Preparation Example 2 had an equivalent ratio of (isocyanate group) :( hydroxyl group + amino group) of 1.15:
A urethane composition was obtained by mixing so as to be 1.

Using the urethane compositions obtained in Examples 5 to 8 and Comparative Examples 8 to 9, a sheet having a thickness of 1.5 mm was produced, and the sheet was cured in a thermostatic chamber at 20 ° C. for 7 days and the physical properties were measured. Two
It was shown to. The Taber abrasion in Table 2 shows the weight loss (mg) after 1000 times with the abrasion wheel H-18 and a load of 1 kg.

[0033]

[Table 2]

Examples 9 to 10 and Comparative Example 10 The urethane prepolymers A, B and C of Examples 1, 4 and 8 were cast on a glass plate at 20 ° C. and a relative humidity of 6.
Leave it in a 5 ° C atmosphere for 14 days to wet-cure it to a thickness of 0.5.
mm sheets were manufactured and the physical properties were measured, and the results are shown in Table 3.

[0035]

[Table 3]

[0036]

The composition of the present invention is a PTM having a particularly narrow molecular weight distribution and a number average molecular weight of 850 or less.
By using the isocyanate-terminated urethane prepolymer composed of G and TDI, there is no problem in on-site construction even in the winter, and a urethane cured product with higher strength than the conventional urethane prepolymer composed of polypropylene ether glycol and TDI is used. Can be formed on-site for the full year.

Continuation of the front page (51) Int.Cl. ⁵ Identification number Office reference number FI technical display location C09K 3/18 101 8318-4H

Claims (2)

[Claims] 1. A urethane prepolymer comprising a polyol and an isocyanate, which is a polytetramethylene ether glycol having a number average molecular weight of 850 or less and a ratio of the weight average molecular weight to the number average molecular weight of 1.8 or less. An isocyanate-terminated urethane prepolymer in which the isocyanate is tolylene diisocyanate and the equivalent ratio of hydroxyl groups to isocyanate groups is 1: 1.7 to 1: 2.2 2. A two-component urethane composition comprising the isocyanate-terminated urethane prepolymer according to claim 1 and a curing agent.