KR20040073979A - Moisture curable type urethane composition - Google Patents

Abstract

PURPOSE: A moisture curable urethane composition is provided, to improve curing property, heat resistance and maintenance rate of properties, to prevent the deformation of appearance of coat even if dipped in an alkali water and to inhibit the foaming of a coat in curing. CONSTITUTION: The moisture curable urethane composition comprises a urethane prepolymer which contains a polyoxyalkylene ring in molecule and has at least two terminal isocyanate groups; a urethane compound which has at least one terminal oxazolidine group and is obtained by reacting a urethane prepolymer containing a polyoxyalkylene ring in molecule and having at least two terminal isocyanate groups and/or polyisocyanate and an N-2-hydroxyalkyl oxazolidine; and a terephthalic acid micropowder whose 90 wt% or more has a diameter of 106 micrometers or less.

Description

Moisture Curing Type Urethane Composition {MOISTURE CURABLE TYPE URETHANE COMPOSITION}

The present invention relates to a moisture-curable urethane composition having no foaming of the coating film at the time of curing, having excellent curability and heat resistance, and having no abnormality in the appearance of the coating film even when immersed in alkaline water and having high retention of physical properties.

Conventional moisture-curable urethane compositions consist of prepolymers obtained by reacting a polyol containing a specific amount of ethylene oxide units with an organic diisocyanate (see, for example, Japanese Patent Application Laid-Open No. 57-94056). However, the composition has a problem in that the coating film is often expanded due to the carbon dioxide gas generated when the water reacts with the isocyanate group during curing.

In order to suppress the generation of carbonic acid gas caused by expansion, moisture dissociation type crosslinking agents such as ketimine, enamine and oxazolidine have been proposed, and among them, urethane using oxazolidine The composition (see, for example, Japanese Patent Laid-Open Nos. 6-293821, 7-33852, and 7-10949) is a material that exhibits relatively balanced performance without generating carbon dioxide.

However, since these urethane compositions tend to be inferior in heat resistance, moisture-curable urethane compositions containing terephthalic acid and improving heat resistance have been proposed (for example, JP-A-11-322894). By the way, when the hardened | cured material by the urethane composition containing terephthalic acid marketed is immersed in alkaline water etc., a void will generate | occur | produce in a coating film, and it will tend to be bad in appearance, or the retention of a physical property will tend to fall.

An object of the present invention is to provide a moisture-curable urethane composition having no foaming of the coating film at the time of curing, having excellent curability and heat resistance, and having no abnormality in the appearance of the coating film even when immersed in alkaline water and having high retention of physical properties.

The present inventors have diligently studied these problems and found that since the commercially available terephthalic acid has a large particle diameter, problems with the appearance of the coating film occur when the cured product is immersed in alkaline water. When terephthalic acid containing the specific amount of particle | grains whose particle diameter is 106 micrometers or less was used, it turned out that there is no abnormality in the external appearance of the coating film by alkaline water, and the retention of a physical property is high. This invention is made | formed based on this knowledge.

That is, the present invention is a urethane prepolymer containing a polyoxyalkylene ring in the (A) molecule, having at least two isocyanate groups at the terminal, and a polyoxyalkylene ring in the (B) molecule, and having at least two at the terminal Urethane compounds having at least one oxazolidine group at a terminal obtained by reacting a urethane prepolymer (b1) and / or polyisocyanate (b2) containing an isocyanate group with N-2-hydroxyalkyloxazolidine (b3), and ( C) Provide a moisture-curable urethane composition containing at least 90% by weight of terephthalic acid fine particles having a particle diameter of 106 μm or less.

Hereinafter, the present invention will be described in more detail.

A urethane prepolymer (hereinafter referred to as (A) urethane prepolymer) containing a polyalkylene ring in the molecule (A) used in the present invention and having two or more isocyanate groups at its terminals reacts the polyisocyanate with a polyoxyalkylene polyol Get it done.

As said polyisocyanate, 2, 4- tolylene diisocyanate, 2, 6- tolylene diisocyanate, diphenylmethane diisocyanate, the diphenylmethane diisocyanate in which carbodiimide was partially, polymethylene polyphenyl, for example Aromatics such as polyisocyanate, tolylene diisocyanate, naphthalene diisocyanate, phenylene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, xylylene diisocyanate, hydrogenated xylylene diisocyanate, hydrogenated diphenylmethane diisocyanate, cyclohexane diisocyanate Diisocyanate, aliphatic diisocyanate, alicyclic diisocyanate and the like, and one or a mixture of two or more thereof can be used. However, the polyisocyanate is not limited to these examples.

Moreover, as said polyoxyalkylene polyol, polyoxyethylene glycol, polyoxypropylene glycol, polyoxy butylene glycol, etc. are mentioned, for example. These polyoxyalkylene polyols are ethylene glycol, propylene glycol, water, glycerin, trimethylolpropane, pentaerythritol, etc. alone or in combination of two or more thereof by a known method. You can get it. However, the polyoxyalkylene polyol is not limited to these examples. In view of workability and curability, the number average molecular weight of such polyoxyalkylene polyol is preferably 500 to 16,000.

The (A) urethane prepolymer used for this invention is manufactured by the conventional method which makes the equivalent ratio of the isocyanate group to the hydroxyl group an excess ratio in the above-mentioned polyisocyanate and polyoxyalkylene polyol. Specifically, the molar ratio (NCO / OH ratio) of the isocyanate groups to the hydroxyl groups in the polyisocyanate and the polyol is preferably 1.4 or more, and particularly preferably 1.4 to 5.0. (A) It is preferable that the quantity of isocyanate group in a urethane prepolymer is 1-20 weight% from a viewpoint of workability and curability.

It is preferable that the (A) urethane prepolymer contains a polyoxybutylene ring as a polyoxyalkylene ring in view of its water resistance, and preferably contains a polyoxypropylene ring in view of the balance of curability and the like. . Moreover, a polyoxyethylene ring can be contained as needed.

(A) It is preferable that a urethane prepolymer contains 5 to 80 weight% of polyoxybutylene rings, and it is preferable to contain 20 to 95 weight% of polyoxypropylene rings. Moreover, you may contain 0 to 10 weight% of polyoxyethylene rings.

The number of terminal isocyanate groups of the (A) urethane prepolymer is preferably two or more, particularly preferably 2-3, in consideration of the curability.

In addition, a urethane compound (hereinafter, referred to as (B) oxazolidineurethane compound) having at least one oxazolidine group at the terminal (B) used in the present invention has a polyoxyalkylene ring in the molecule and is at the terminal. It is obtained by making a urethane prepolymer (b1) or polyisocyanate (b2) which has two or more isocyanate groups, and N-2-hydroxyalkyloxazolidine (b3) react.

As the urethane prepolymer (hereinafter, referred to as (b1) urethane prepolymer) having a polyoxyalkylene ring in the molecule (b1) and having two or more isocyanate groups at its terminals, the above-mentioned (A) urethane prepolymer can be used. (A) It is preferable to use urethane prepolymers other than a urethane prepolymer.

It is preferable that the polyoxyalkylene ring of this (b1) urethane prepolymer contains a polyoxyethylene ring in view of the cure rate, curability and water resistance. Such polyoxyethylene ring is preferably contained 1 to 30% by weight in the polyoxyalkylene ring. Other components of this polyoxyalkylene ring are polyoxypropylene ring and polyoxybutylene ring.

It is preferable that the polyoxyethylene ring in the said (A) urethane prepolymer and (b1) urethane prepolymer is less than 10 weight% with respect to the total amount of the said (A) urethane prepolymer and (b1) urethane prepolymer. When the content of the polyoxyethylene ring is in the above range, the water resistance becomes excellent.

The urethane prepolymer (b1) preferably has a number average molecular weight of 500 to 8,000. When the number average molecular weight of the (b1) urethane prepolymer is in the above range, satisfactory base material followability and curing rate can be obtained.

(b1) It is preferable that the number of isocyanate groups of the urethane prepolymer terminal is 2.0-2.6 on average. When the number of isocyanate groups is in the above range, the curability and the substrate followability are excellent. In addition, it is preferable to adjust the ratio of isocyanate and polyol so that NCO / OH ratio may be 1.6 or more, and it is especially preferable that the ratio is 1.8-4.0. (b1) It is preferable that isocyanate group content in a urethane prepolymer is 1-15 weight%.

Moreover, when (b) N-2-hydroxyalkyloxazolidine used for manufacture of (B) oxazolidine urethane compound is mentioned, Aldehydes, such as formaldehyde, acetaldehyde, a propyl aldehyde, a butylaldehyde, benzaldehyde, And those obtained by condensation reaction with dihydroxyalkylamines such as diethanolamine and dipropanolamine. However, the above N-2-hydroxyalkyloxazolidine is not limited to these examples.

(B) It is preferable that the number of terminal oxazolidine groups of an oxazolidine urethane compound is 1-3. When the number of terminal oxazolidine groups of the said oxazolidine urethane compound exists in the said range, the extensibility after hardening becomes high and favorable physical property is obtained. The terminal of the (B) urethane oxazolidine compound may be one having at least one oxazolidine group, and other functional groups may be present at the other terminal.

In the (b1) urethane prepolymer and (b3) N-2-hydroxyalkyloxazolidine, the molar ratio (NCO / OH) of the isocyanate group to the hydroxyl group is preferably 0.95 to 3.0. When the said NCO / OH exists in such a range, the tendency which unreacted N-2-hydroxyalkyloxazolidine remains is low, storage stability improves, and it is easy to suppress the fall of a cure rate and a raise of a viscosity. Done.

As (b1) polyisocyanate used for this invention, the polyisocyanate described as a raw material of the said (A) urethane prepolymer can be used.

The ratio of (A) urethane prepolymer and (B) oxazolidine urethane compound is equivalent ratio (NCO) of the active hydrogen atom-containing group which is generated when the isocyanate group of (A) urethane prepolymer and (B) oxazolidine urethane compound ring-open with water. / H) is preferably in the range of 0.4 to 4.0, more preferably in the range of 0.5 to 2.5. In the said range, since generation | occurrence | production of a carbon dioxide gas is low and expansion of a coating film can be suppressed, storage stability becomes excellent. In view of this point, it is preferable that the weight ratio of the (A) urethane prepolymer and the (B) oxazolidine urethane compound is in the range of (A) :( B) = 60: 1 to 1:30.

Terephthalic acid fine particles having a particle diameter of at least 90% by weight (C) used in the present invention having a particle diameter of 106 µm or less means that at least 90% by weight of terephthalic acid is composed of terephthalic acid particles having a particle diameter of 106 µm or less. Preferably, at least 95% by weight of terephthalic acid is terephthalic acid fine particles having a particle diameter of 106 μm or less. Moreover, it is preferable that the average particle diameter of the said microparticles | fine-particles is 1-60 micrometers. In addition, it is preferable that the terephthalic acid microparticles | fine-particles of this invention are terephthalic acid with purity 98% or more.

As a result of testing the commercial product of terephthalic acid by the dry sieve analysis method, the content of the terephthalic acid particle whose average particle diameter is 70-120 micrometers and whose particle diameter is 106 micrometers or less was 70-85 weight%. In the case of containing only less than 90% by weight of terephthalic acid particles having a particle diameter of 106 µm or less, when the cured coating film is immersed in alkaline water or the like, voids are generated by reaction with an alkali compound, resulting in poor appearance, and cause physical property degradation.

The particle diameter of (C) terephthalic acid microparticles | fine-particles used for this invention shows the numerical value measured using a dry sieve analysis method or Microtrac FRA (made by MOUNTECH Co. Ltd.).

The above-described dry sieve analysis method refers to a method of sifting particles dry by using various sieve networks having different particle diameters defined in JIS-Z-8801-1 (2000). The particle | grains whose particle diameter is 106 micrometers or less are particle | grains which passed the sieve network whose name body is 106 micrometers. Microtrac FRA (manufactured by MOUNTECH Co. Ltd.) is an apparatus for measuring the particle diameter of a paste-like material.

The terephthalic acid microparticles | fine-particles used for this invention are the said terephthalic acid commercial item, liquid polyoxyalkylene polyol, for example, polypropylene glycol, polybutylene glycol, polyethyleneglycol, etc. which have a number average molecular weight of 1,000-5,000, and a dehydrating agent (ethyl silicate etc.). After mixing with a mixer, it is preferable to manufacture by crushing-dispersing with a disperser. It is preferable that the mixing ratio of commercially available terephthalic acid and a polyalkylene polyol is 1: 0.8-1.2 by weight ratio, More preferably, it is 1: 1.

As a mixer in the above case, a butterfly mixer, a kneader, etc. can be illustrated, and as a disperser, a roller mill, a ball mill, a bead mill, etc. can be illustrated. have.

Moreover, the polyoxyalkylene polyol used at the time of crushing dispersion, etc. can also be removed after crushing dispersion, and when polyoxyalkylene polyol remains in the quantity of 40-60 mass%, it can be used as it is, without removing it. When content of the said polyol is in the said range, since mixing into a composition becomes easy, mixing dispersibility will improve. Thereby, (C) terephthalic acid microparticles | fine-particles disperse | distribute uniformly, alkali resistance of a coating film improves and a void does not generate easily.

When terephthalic acid microparticles | fine-particles obtained in this way by 90 weight% or more have a particle diameter of 106 micrometers or less are used, even if a small amount is added, heat resistance improves very much, and even if a hardened coating film is immersed in alkaline water, there is no abnormality in the external appearance of a coating film, and a physical property retention rate This exerts an excellent effect.

It is preferable that content of (C) terephthalic acid microparticles | fine-particles is 0.05-20 weight%. When the content of the terephthalic acid fine particles is less than 0.05%, the effect of improving heat resistance is small. When the content of the terephthalic acid fine particle is more than 20% by weight, an additional heat resistance improving effect cannot be expected even when blended at an excess content. The content of the terephthalic acid fine particles is preferably 0.1 to 10% by weight, more preferably 0.1 to 5% by weight.

The moisture-curable urethane composition of the present invention preferably further contains a naphthenic hydrocarbon having a number average molecular weight of 150 or more and / or a paraffinic hydrocarbon having a number average molecular weight of 150 or more.

As the naphthenic hydrocarbon having a number average molecular weight of 150 or more and the paraffinic hydrocarbon having a number average molecular weight of 150 or more, for example, tridecane, tetradecane, pentadecane, hexadecane, cyclododecane, cyclotridecane, cyclotetra Deccan etc. are mentioned. Moreover, as these commercial items, Exol D-80 (number average molecular weight 177, Exxon Chemical Co., Ltd.), exol D-110 (number average molecular weight 217, Exon Chemical Co., Ltd.), exol D-130 (number average molecular weight 240, Exxon Chemical Co., Ltd. make) ), And the like. However, the present invention is not limited to these examples. When the hydrocarbon having the number average molecular weight of 150 or more is used, volatility is low and shrinkage of the cured product is also reduced.

The content of the naphthenic hydrocarbon having a number average molecular weight of 150 or more and / or the paraffinic hydrocarbon having a number average molecular weight of 150 or more is preferably 1 to 15% by weight. If the said content is the range of 1-15 weight%, the viscosity of a composition will become appropriate, workability will become favorable, and the coating film physical properties of hardened | cured material will also become excellent.

In addition, in consideration of environmental safety, the moisture-curable urethane composition of the present invention preferably does not contain an organic solvent.

The moisture-curable urethane composition of the present invention may further include various additives such as a catalyst, an inorganic filler, a plasticizer, a thixotropic agent, a extender pigment, a sunscreen agent for improving the retention of weather resistance, a stabilizer and the like. .

From the viewpoint of environmental safety, it is preferable that such additives do not contain organic solvents such as toluene and xylene, which are specified in the organic solvent law of the Japanese Labor Safety and Sanitary Act.

The moisture-curable urethane composition of the present invention can be produced by mixing and kneading the above raw materials uniformly.

In this case, when a kneading apparatus used for kneading is illustrated, a planetary mixer etc. can be mentioned.

As said thixotropic agent, surface-treated calcium carbonate, polyvinyl chloride powder, fine powder silica, bentonite, etc. are mentioned, for example. In addition, petroleum high boiling point aromatic fraction, petroleum resin, etc. can also be used together.

As the catalyst, a known catalyst such as salicylic acid or dibutyl tin dilaurate (DBTDL) can be used.

Examples of the plasticizer include dibutyl phthalate, dioctyl phthalate, diundecyl phthalate, dilauryl phthalate, butyl benzyl phthalate, diisodecyl phthalate, dibutyl adipate, dioctyl adipate, diisononyl adipate, and dioctyl. Ester plasticizers such as azelate and dioctyl sebacate, and phosphate ester plasticizers such as trioctyl phosphate and triphenyl phosphate.

Examples of the stabilizer include antioxidants, ultraviolet absorbers, and the like. Examples of the inorganic fillers include inorganic compound powders such as calcium carbonate, calcium oxide, clay, talc, titanium oxide, aluminum sulfate, kaolin, diatomaceous earth, and glass balloons. It is preferable that the addition amount is 5-70 weight% in the moisture-curable urethane composition of this invention, More preferably, it is 10-60 weight%.

The moisture-curable urethane composition of the present invention can be used for applications such as coating materials, sealants, adhesives and the like.

The composition of the present invention can be used as a coating material, paint, roof waterproofing material of buildings, parking lot waterproofing material, wall material, flooring material, surface pavement material of stadium.

Moreover, the composition of this invention can be used for sealing materials for civil construction, such as concrete, a sizing board, a metal, as a sealing material.

In addition, the composition of the present invention, as an adhesive, adhesives for building interior materials such as plastic flooring, waterproof sheet adhesive on the roof, adhesives for tiles, sheets; It can be used as a binder of particulate matter such as natural stone, ceramic, rubber, wood, and fibrous material.

The composition of the present invention is particularly effective for the use of concrete as the base material among these applications in that it is excellent in heat resistance and does not cause abnormal appearance of the coating film when immersed in alkaline water.

(Example)

Next, although an Example and a comparative example demonstrate this invention in detail, this invention is not limited to these Examples. In the following, parts and percentages are to be on a weight basis unless otherwise indicated.

Synthesis Example 1 [Synthesis of (A) Urethane Prepolymer]

700 g (0.35 mol) of polybutylene etherdiol having a number average molecular weight of 2,000 and 300 g (0.1 mol) of polypropylene ether triol having a number average molecular weight of 3,000 were 191.4 g (1.1 mol) of 2,4-tolylene diisocyanate, That is, the equivalent ratio of NCO / OH was set to 2.2, and the mixture was reacted with stirring at 80 ° C. for 15 hours under a nitrogen stream, thereby obtaining a urethane prepolymer having an isocyanate group of 4.25%. Hereinafter, the said urethane prepolymer is called urethane prepolymer (A-1).

Synthesis Example 2 [Synthesis of (A) Urethane Prepolymer]

The same method as in Synthesis Example 1, except that 700 g (0.35 mol) of polypropylene etherdiol having a number average molecular weight of 2,000 was used instead of 700 g (0.35 mol) of polybutylene etherdiol having a number average molecular weight of 2,000 in Synthesis Example 1. To a urethane prepolymer having an isocyanate group of 4.28%. Hereinafter, the said urethane prepolymer is called urethane prepolymer (A-2).

Synthesis Example 3 [Synthesis of (B) oxazolidine urethane compound]

500 g (0.104 mol) of polyethylene propylene ether triol having a number average molecular weight of 4,800 and 15% of an oxyethylene ring and 500 g (0.25 mol) of polypropylene ether diol having a number average molecular weight of 2,000 were mixed, A polyol having an average content of rings of 7.5%, an average number of functional groups of 2.29 and a number average molecular weight of 2,820 was obtained. Further, hexamethylene diisocyanate was reacted with 143.3 g (0.853 mol), that is, an equivalent ratio of NCO / OH of 2.1 at 80 ° C. under a stream of nitrogen for 48 hours with stirring, with an isocyanate group of 3.28%, 1 A urethane prepolymer having 2.29 terminal NCO groups per molecule was obtained. Hereinafter, the said urethane prepolymer is called urethane prepolymer (b1-1).

140.8 g of the urethane prepolymer (b1-1) and 15.9 g of 2-isopropyl3 (2hydroxyethyl) 1,3oxazolidine were used at an equivalent ratio of NCO / OH of 1.1 at 60 ° C. for 48 hours under a nitrogen stream. It reacted in the flask, stirring, and obtained the urethane oxazolidine compound (henceforth OXZ-1).

As a result of measuring gas permeation chromatography (GPC) of OXZ-1, it was confirmed that the content of residual 2-isopropyl 3 (2hydroxyethyl) 1,3 oxazolidine was 1% or less.

Preparation Example 1 [Preparation of terephthalic acid fine particle / polyalkylene polyol mixture]

At room temperature, 500 g of terephthalic acid, 500 g of polypropylene etherdiol and 20 g of ethyl silicate as a dehydrating agent were premixed with a butterfly mixer for 15 minutes, followed by kneading three times with three roll mills to carry out crushing dispersion, and 50 parts of terephthalic acid particles were weighed. A mixture of% and 50% by weight of polypropyleneetherdiol was obtained.

The particle size distribution of the terephthalic acid fine particles in the mixture was measured using Microtrac FRA (manufactured by MOUNTECH Co. Ltd.), and it was found that 98 wt% of particles having a particle diameter of 106 μm or less was included, and that the average particle diameter of the terephthalic acid fine particles was 40 μm. Confirmed.

Examples 1-3 and Comparative Examples 1-4

The urethane prepolymer, OXZ-1, and terephthalic acid obtained as described above were blended in the mixing ratios of Tables 1 and 2, and further dried under reduced pressure at 120 ° C. for 5 hours in a hermetic planetary mixer to adjust moisture to 500 ppm or less. 380 parts of calcium carbonate (NS-200 manufactured by Nippon Chemical Co., Ltd.), 90 parts of 2-ethylhexyl phthalate and 0.1 part of salicylic acid were added and mixed uniformly, followed by defoaming at 60 torr under reduced pressure to obtain a moisture curable urethane composition.

Subsequently, the moisture curable urethane composition was tested for viscosity, curability, non-foaming property, shrinkage rate, tensile property, heat resistance and alkali resistance.

[Test Methods and Evaluation Criteria]

Viscosity: The sample was adjusted to 25 degreeC, and the viscosity was measured using the BM type rotational viscometer.

Curability: A sample is poured on a glass plate (30 × 30 cm) with release paper wrapped around the frame at a rate of 1.5 mm, left under 25 ° C x 50% humidity, and touched by a finger to eliminate the movement of the coating film. The time until was measured.

Non-foaming property: The sample is made to flow on a slate plate (30 × 30 cm) surrounded by a frame at a ratio of 2 mm in thickness, and cured under a condition of 50 ° C. × humidity 90%, followed by expansion of the coating film surface and pinholes. Was observed with the naked eye.

Evaluation criteria set the thing without expansion and a pinhole to (circle), and the thing with expansion and a pinhole to be x.

Shrinkage rate: The sample was made to flow on the slate board (30x30 cm) which enclosed the frame at the ratio of 2 mm in thickness, and it cured for 7 days under 23 degreeC conditions, and formed the coating film. This coating film is cut | disconnected in 2.5x30 cm rectangle. After precisely measuring the transverse length and curing for 7 days in a 50 ° C. dryer, the transverse length was again measured accurately, compared with the length before curing at 50 ° C., and the shrinkage of the coating film was calculated.

Tensile Properties: A sample was poured on a glass plate (30 × 30 cm) with release paper enclosed in four directions at a rate of 1.5 mm, left to cure under conditions of 23 ° C. and 50% humidity for 14 days to form a coating film. It was. The tensile strength (N / cm <2>) and the elongation at break (%) of the normal state with respect to the said coating film were measured on the conditions which the tensile speed was 500 mm / min using the tensile tester.

Heat resistance: A sample was prepared according to the state tensile property test method, and the sample was cured in an 80 ° C. dryer for 7 days and then taken out. Subsequently, after standing for 24 hours under conditions of 23 ° C. and 50% humidity, the tensile strength (N / cm 2) and the elongation at break (%) of the sample were measured according to the state tensile property test method.

Alkali resistance: A sample was prepared in accordance with the state tensile physical property test method, and the sample was immersed in a 23 ° C cement saturated solution for 5 days, and then taken out, and the appearance thereof was visually observed. Thereafter, the sample was allowed to stand for 24 hours under conditions of 23 ° C. and 50% humidity, and then tensile strength (N / cm 2) and elongation at break (%) were measured according to the tensile test method.

In addition, about the external appearance change of the said sample, the thing with no generation | occurrence | production of a void was made into "none", and the thing with generation | occurrence | production of void was shown as "void generation".

The compounding conditions and test results of the moisture-curable urethane composition are shown in Table 1, Table 2 and Table 3.

Table 1

Example 1 Example 2 Example 3 combination Urethane Prepolymer A-1 290 - 290 Urethane Prepolymer A-2 - 290 - OXZ-1 210 210 210 Ultra fine powder TPA 2 5 2 D-80 80 80 - Solvesso 200 - - 80 Viscosity (m㎩ / 25 ℃) 5700 5900 5200 Curability (time) 6 7 7 Non-foaming ○ ○ ○ Shrinkage (%) -0.8 -0.9 -2.1 State The tensile strength 3.3 3.1 2.9 Elongation at break 550 590 505 After heat The tensile strength 3.1 3.1 2.7 Elongation at break 580 550 525 After alkali resistance Appearance change none none none The tensile strength 3.1 2.4 2.8 Elongation at break 580 680 550

Table 2

Comparative Example 1 Comparative Example 2 Comparative Example 3 combination Urethane Prepolymer A-1 290 290 290 OXZ-1 210 210 210 Commercial TPA 2 5 - Fine Powder TPA - - 2 D-80 80 80 80 Viscosity (m㎩ / 25 ℃) 5300 5200 5500 Curability (time) 9 8 9 Non-foaming ○ ○ ○ Shrinkage (%) -0.9 -1.0 -1.0 State The tensile strength 2.7 2.7 3.0 Elongation at break 570 540 575 After heat The tensile strength 2.0 2.5 2.5 Elongation at break 700 590 710 After alkali resistance Appearance change Void generation Void generation Void generation The tensile strength 1.2 1.0 1.8 Elongation at break 415 380 425

Table 3

Comparative Example 4 Comparative Example 5 combination Urethane Prepolymer A-1 290 500 OXZ-1 210 - Commercial TPA - 2 Fine Powder TPA - - D-80 80 80 Viscosity (m㎩ / 25 ℃) 5800 5500 Curability (time) 9 24 or more Non-foaming ○ × Shrinkage (%) -0.8 -1.3 State The tensile strength 2.8 2.1 Elongation at break 580 805 After heat The tensile strength 1.2 1.8 Elongation at break 815 935 After alkali resistance Appearance change none none The tensile strength 2.4 1.8 Elongation at break 575 950

In Table 1, Table 2 and Table 3, the meaning of the ultra-fine powder TPA, commercially available TPA, fine powder TPA, D-80, Solvesso 200, after heat resistance and alkali resistance.

Ultra fine powder TPA: The terephthalic acid fine particles obtained in Preparation Example 1. Terephthalic acid having a content of terephthalic acid particles having a particle diameter of 106 μm or less and 98 wt%, and having an average particle diameter of 40 μm.

Commercially available TPA: Terephthalic acid fine particles produced by Mitsubishi Chemical. Terephthalic acid having a content of terephthalic acid particles having a particle diameter of 106 mu m or less and 75 wt%, and having an average particle diameter of 90 mu m.

Fine powder TPA: Terephthalic acid having a content of terephthalic acid particles having a particle diameter of 106 μm or less and 86 wt%, and an average particle diameter of the particles of 57 μm.

D-80: A mixture of a naphthenic hydrocarbon and an isoparaffinic hydrocarbon having a number average molecular weight of 177 (manufactured by Exon Chemical).

Solvesso 200: Aromatic hydrocarbons (manufactured by Exon Chemical) having a number average molecular weight of 166.

After heat resistance: Physical properties after heating a sample according to the heat resistance test method described above.

After alkali resistance: The physical property after immersing a sample in the cement saturated solution according to the alkali tolerance test method mentioned above.

As shown in Table 1, Table 2 and Table 3, the composition according to the Example showed excellent performance, but the composition of Comparative Example 1 and Comparative Example 2 using a commercially available terephthalic acid, when immersed in alkaline water, the physical property retention rate is low and the coating film Voids occurred and were poor in appearance. In addition, Comparative Example 3 using fine powder terephthalic acid having a content of terephthalic acid particles having a particle diameter of 106 μm or less was 86% by weight also, when immersed in alkaline water, voids occurred in the coating film and were poor in appearance, and physical properties after immersion in alkaline water were also observed. The results were markedly lower than usual. Comparative Example 4, which did not use terephthalic acid, showed no appearance defects after being immersed in alkaline water, but the heat resistance was remarkably low, which was not suitable for practical use. In addition, in the case of the comparative example which does not contain an oxazolidine compound, hardening was inferior to foamability and it was not suitable for practical use.

The moisture-curable urethane composition of the present invention has no foaming of the coating film at the time of curing, and is excellent in curability and heat resistance. Therefore, the moisture-curable urethane composition of the present invention can be widely used as a coating material, a sealing material, an adhesive, and the like. It is useful for applications where the substrate is concrete because of its high retention of physical properties.

Claims (5)

Urethane prepolymer containing a polyoxyalkylene ring in the molecule (A) and having at least two isocyanate groups at the terminal, Urethane prepolymer containing a polyoxyalkylene ring in the molecule (B) and containing at least two isocyanate groups at the terminal (b1) and / or a urethane compound having at least one oxazolidine group at a terminal obtained by reacting polyisocyanate (b2) with N-2-hydroxyalkyloxazolidine (b3), and (C) at least 90% by weight The moisture hardening type urethane composition containing the terephthalic acid microparticles | fine-particles which have a particle diameter of 106 micrometers or less. The method of claim 1, The moisture-curable urethane composition containing the polyoxyalkylene ring in said (A) molecule | numerator, and the polyoxyalkylene ring of the urethane prepolymer which has at least 2 isocyanate group at the terminal is a polyoxybutylene ring and a polyoxypropylene ring. The method of claim 2, The moisture-curable urethane composition in which said (A) urethane prepolymer contains 5 to 80 weight% of a polyoxybutylene ring and 20 to 95 weight% of a polyoxypropylene ring. The method of claim 1, The moisture-curable urethane composition whose average particle diameter of the said (C) terephthalic acid microparticles | fine-particles is 1-60 micrometers. The method of claim 1, The moisture-curable urethane composition obtained by the said (C) terephthalic acid microparticles | fine-particles obtained by mixing a polyoxyalkylene polyol and terephthalic acid, and crushing with a disperser.