JP3197636B2 - Urethane composition - Google Patents

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 as a waterproof coating, a floor covering, a pavement, a sealing material and the like.

[0002]

2. Description of the Related Art Conventionally, a room temperature urethane composition used for a coating film waterproofing agent, a coated floor material, a pavement material, etc.
Polyol such as polypropylene ether glulicol or triol and tolylene diisocyanate (TD
An isocyanate-terminated urethane prepolymer which is a reaction product with an aromatic diisocyanate such as I) is used as an isocyanate component (A component) and reacts with isocyanates such as glycols, polypropylene ether glycol or triol, polycaprolactone polyol, and aromatic polyamine. An active hydrogen compound is used as a curing agent (component B), and after the components A and B are mixed at the construction site, the mixture is cast and applied on an object to be coated and cured at room temperature. Was the subject.

[0003] TDI is usually used as a raw material isocyanate for producing this isocyanate-terminated urethane prepolymer (component A). However, when diphenylmethane diisocyanate (MDI) is used, the viscosity of the prepolymer is high and the B component and This is because the reactivity is large and inconvenience is likely to occur in the operation.

As a polyol which is one of raw materials for producing the component A, or as a polyol of the component B,
Although it is conceivable to use polytetramethylene ether glycol (PTMG), PTMG itself is crystallized at room temperature or low temperature, which is inconvenient as a curing agent (component B). When used as a raw material polyol, the isocyanate-terminated urethane prepolymer, which is a reaction product of PTMG and TDI, solidifies in winter and causes inconvenience in on-site construction. If such A component and B component are heated, the crystals once precipitated will melt, but in the field of the present invention, it is important to work at the environmental temperature even in winter (low temperature), and it is difficult to heat on site. It is.

Accordingly, isocyanate-terminated urethane prepolymers using PTMG and TDI have been conventionally used in the fields of coating waterproofing agents, coated flooring materials, pavement materials, etc., which are important for the whole-year (normal or low temperature) application of the present invention. Was considered impossible.

[0006]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems associated with the use of PTMG, the present invention aims to solve the above-mentioned problems by using PTMG and PTMG and TDI which do not crystallize even at a low temperature.
By producing an isocyanate-terminated urethane prepolymer consisting of isocyanate component and using it as an isocyanate component, there is no trouble in operation even at low temperature, and isocyanate-terminated urethane prepolymer using polypropylene ether polyol consisting of conventional polypropylene ether polyol and TDI. It is an object of the present invention to provide a urethane composition which gives a higher strength cured property than a urethane composition comprising a polymer and a curing agent.

[0007]

The present inventors have proposed PTMG having a number average molecular weight of 850 or less and a ratio of weight average molecular weight to number average molecular weight of 1.8 or less, TDI, a hydroxyl group and an isocyanate. The equivalent ratio of the groups is 1: 1.7 to 1:
By performing the reaction in 2.2, the amount of solvent used can be reduced to 10
% (Weight), it is possible to produce an isocyanate-terminated urethane prepolymer which is stored at 0 ° C. and does not crystallize at 0 ° C. By using this as an isocyanate component, there is no problem in operation at ambient temperature even in winter. ,
In addition, it has been found that the physical properties of the cured coating film provide higher tensile strength, higher tear strength, higher abrasion resistance, and higher weather resistance than when a conventional polypropylene ether polyol is used.

That is, the present invention is as follows. In a urethane prepolymer comprising a polyol and an isocyanate, the polyol has a number average molecular weight of 8
Polytetramethylene ether glycol (PTMG) having a weight average molecular weight and a number average molecular weight of not more than 50 and a ratio (weight average molecular weight / number average molecular weight) of not more than 1.8, and the isocyanate is tolylene diisocyanate (T
DI), wherein the equivalent ratio of hydroxyl groups to isocyanate groups is from 1: 1.7 to 1: 2.2. A two-part 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 weight average molecular weight to number average molecular weight (weight average molecular weight / number average molecular weight) of 1.8 or less. If the number average molecular weight is 850 or more, the isocyanate-terminated urethane prepolymer composed of PTMG and TDI crystallizes 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.

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

In order to produce an isocyanate-terminated urethane prepolymer by reacting PTMG and TDI, it is necessary to use PTM
The components are charged so that the equivalent ratio of the hydroxyl group of G to 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 residual amount of unreacted free TDI after the reaction becomes too large. However, inconveniences arise during the full-year construction of the present invention.

The isocyanate-terminated urethane prepolymer is prepared by mixing TDI and PTMG used in the present invention in a nitrogen stream at 40 to 90 ° C. in an equivalent ratio of hydroxyl group to isocyanate group of 1: 1.7 to 1: 2.2. Produced by heating for hours.

The isocyanate-terminated urethane prepolymer comprising PTMG and TDI of the present invention is used as an isocyanate component (A component), and a polyol and / or aromatic polyamine crosslinking agent, if necessary, a plasticizer, a filler, and a curing accelerator. A high-strength waterproofing material is obtained by using a curing agent containing a colorant or the like as a B component, mixing a predetermined amount of the A component and the B component on site, and casting or spraying the mixture on an object to be cured. , Flooring materials, pavement materials, sealing materials, etc. can be formed by full-year (normal or low temperature) construction.

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 are polypropylene ether glycols or triols, polyester polyols, polycaprolactone polyols, polybutadiene polyols, polyacryl polyols, and polymer polyols obtained by graft polymerization of acrylonitrile, styrene, and the like to polyethylene-polypropylene ether polyol. And castor oil.

As the aromatic polyamine crosslinking agent contained in the curing agent (component B) used in the present invention, 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
3'-tetrachloro-4,4'-diaminodiphenylmethane and the like. These aromatic polyamines are
Except for the mixture of 3,5-dimethylthio-2,4-toluenediamine and 3,5-dimethylthio-2,6-toluenediamine, many of them are solid at normal temperature, so they are included in the curing agent (component B) in advance. Used in the form of a polyol or plasticizer. In addition to aromatic polyamines, water can also be used as a crosslinking agent. When water is used, it is necessary to use a carbon dioxide absorbent such as slaked lime or cement.

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

As the filler contained in the curing agent (component B) used in the present invention, carbon black, calcium carbonate, talc, kaolin, zeolite, siliceous earth, glass fiber and the like are used. The compounding amount 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, and tin 2-ethylhexoate. Organometallic catalysts such as acetate, lead naphthenate, bismuth octoate, bismuth neodecanoate, triethylamine, N-
Tertiary amines such as methylmorpholine, teramethylethylenediamine, and triethylenediamine are used.
The compounding amount is 10% by weight or less in the curing agent (B component),
It is preferably at most 3% by weight.

The isocyanate-terminated urethane prepolymer comprising PTMG and TDI of the present invention is used as the component A, and the above polyol and / or aromatic polyamine, crosslinker, plasticizer, filler, colorant, and, if necessary, curing acceleration A curing agent kneaded by adding an agent, a stabilizer, and the like is used as the B component, and the equivalent ratio of the total active hydrogen, which is the sum of the isocyanate group in the A component and the hydroxyl group and / or amino group in the B component, is 0. A-component and B-component are mixed so as to be 9 to 1.4, preferably 1.0 to 1.2, and are cast onto a substrate by a spatula, a trowel, a roll brush, or the like, or by air spraying or the like. Spray coating and curing under environmental conditions provide higher strength and abrasion resistance than conventional polypropylene ether polyols and prepolymers derived from TDI Sex good waterproofing agents, coating flooring,
Pavement materials, sealing materials, etc. can be formed by construction throughout the period (normal temperature or low temperature).

The isocyanate-terminated urethane prepolymer obtained from PTMG and TDI of the present invention can be used as a one-pack moisture-curable paint, a binder or an adhesive which cures with atmospheric moisture. It shows better cured properties than using a prepolymer obtained from TDI.

[0021]

EXAMPLES The present invention will be described below with reference to examples. Examples 1 to 4, Comparative Examples 1 to 7 The ratio between the weight average molecular weight and the number average molecular weight, and the number average molecular weight shown in Table 1 were polytetramethylene ether glycol (PTMEG), 2,4-form and 2,6-form. The isomers of the isomers were charged so that the equivalent ratio with tolylene diisocyanate of 80/20 was 1: 2, and 50-80 in the reaction vessel.
The reaction was carried out at a temperature of 3 ° C. for 3 hours. The obtained isocyanate-terminated urethane prepolymer was diluted with xylene so as to have a resin content of 95% by weight, and the crystallinity was examined under storage at 0 ° C.

[0022]

[Table 1]

Evaluation method…: No crystallization after storage at 0 ° C. for one month. ×: Crystallized after storage at 0 ° C. for one 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 so as to have a resin content of 90% by weight, and crystallization during storage at 0 ° C. could not be prevented. As seen from Comparative Examples 3 and 4 above, even when 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 becomes 0 ° C. Crystallizes. As shown in Comparative Examples 5, 6, and 7, when the number average molecular weight is 850 or more, the prepolymer crystallizes at 0 ° C even when 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 2,000, 2 parts of lead octoate, 18 parts of dioctyl phthalate and 45 parts of ortho-chloroaniline-formalin condensate "Bisamine" (trade name, manufactured by Wakayama Seika) Was mixed to obtain a curing agent 1.

Preparation Example 2 30 parts of polypropylene ether triol having a number average molecular weight of 3,000, 2 parts of lead octoate, 14 parts of dioctyl phthalate, and 21 parts of ortho-chloroaniline-formalin condensate "Bisamine" (manufactured by Wakayama Seika) And 30 parts of calcium carbonate and 3 parts of a green pigment were mixed to obtain a curing agent 2.

Example 5 The isocyanate-terminated urethane prepolymer of Example 1 (hereinafter referred to as urethane prepolymer A) (NCO content: 6.7)
%) And curing agent 1 of Preparation Example 1 (isocyanate group):
The mixture was mixed such that the equivalent ratio of (hydroxyl group + amino group) was 1.15: 1 to obtain a urethane composition.

Example 6 The isocyanate-terminated urethane prepolymer of Example 4 (hereinafter referred to as urethane prepolymer B) (NCO content: 8.0)
%) And curing agent 1 of Preparation Example 1 (isocyanate group):
The mixture was mixed such that the equivalent ratio of (hydroxyl group + amino group) was 1.15: 1 to obtain a urethane composition.

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

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

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 manufactured, and after cultivation in a constant temperature room at 20 ° C. for 7 days, the physical properties were measured. 2
It was shown to. The Taber abrasion in Table 2 indicates the weight loss (mg) after 1000 cycles with a worn 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 ° C.
Leave in an atmosphere of 5 ° C. for 14 days and wet cure to a thickness of 0.5
mm sheet was manufactured and its physical properties were measured and the results are shown in Table 3.

[0035]

[Table 3]

[0036]

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

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-46-4847 (JP, A) JP-A-63-278923 (JP, A) JP-A-61-155418 (JP, A) (58) Field (Int.Cl. ⁷ , DB name) C08G 18/00-18/87 C09D 175/08

Claims (2)

(57) [Claims] 1. A urethane prepolymer comprising a polyol and an isocyanate, wherein the polyol has a number average molecular weight of 850 or less and a ratio of a weight average molecular weight to a 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 from 1: 1.7 to 1: 2.2. 2. A two-part urethane composition comprising the isocyanate-terminated urethane prepolymer according to claim 1 and a curing agent.