JP2001172360A - Composition for elastomer-forming spray and preparation process for coat using this composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a preparation process of a coat which process can be operated even at a low temperature, does not easily cause foaming by a reaction with water, does not allow the bubbles mixed by stirring to stay in the coat and gives a coat having a good appearance and an excellent durability. SOLUTION: This composition for an elastomer-forming spray comprises two components which are component (A) whose main component is a polyisocyanate compound and component (B) whose main components are a high-molecular-weight active-hydrogen compound and/or a chain extender. For component (A), both an MDI and a carbodiimide modified MDI are used. The MDI has a specific ratio of the amount of 4,4'-MDI to the total amount of 2,2'-MDI and 2,4'-MDI.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to an elastomer-forming spray-curing composition applied to flooring materials, waterproofing agents, concrete covering materials and the like. The present invention relates to a method for producing a polyurethane and / or polyurea elastomer coating, which comprises spraying and curing an elastomer-forming spray-curing composition onto an object such as a concrete frame or a steel plate using a two-liquid high-pressure spray machine.

[0002]

2. Description of the Related Art A technique of high-speed molding by collision-mixing a polyurethane and / or polyurea elastomer in a state where the raw material viscosity is low is known as an RIM method. The raw materials used here are further reduced in viscosity and spray-processed. For example, JP-A-63-304804, JP-A-63-315708, JP-A-2-25
As disclosed in JP-A-8877 and JP-A-3-160016, spraying is used in the field of molding rubber-like elastic materials such as flooring, and is used for floors applied to concrete bases such as open corridors and rooms. It has been used as a material.

Further, as disclosed in Japanese Patent Application Laid-Open No. Hei 8-238453, structures such as sewage treatment facilities, sewers, and wastewater treatment facilities often have closed structures with poor air circulation, and are exposed to acidic atmosphere. As a result, there is a possibility that functional deterioration or environmental destruction may occur due to concrete deterioration. As a countermeasure, a method of forming an anticorrosion organic coating on the concrete surface has been adopted. In addition, the above-described spray coating has been used to apply an elastomer coating as a method of applying a roof waterproofing material for deterioration due to acid rain and waterproofing. Each of these techniques is a method of using a two-component high-pressure spray machine by using a catalyst or an amine-based raw material to form a quick curing type. It is necessary to increase the thickness of the coating to provide waterproofness, corrosion protection and weather resistance.However, unlike solvent-based paints and moisture-curable paints, it is fast-curing and cures completely from the inside. Can be offered.

The raw materials used in the spray processing are similar to those used in the RIM method, and are composed of an isocyanate component consisting of an isocyanate group-containing polyurethane prepolymer and a polyol consisting of a high molecular weight active hydrogen compound and a chain extender. Ingredients are often used. As a method for producing an ultrafast-curing polyurea elastomer with further increased speed, a polyisocyanate component containing an isocyanate group-containing polyurethane prepolymer as an A agent and a chain extender of a high molecular weight polyamine compound and a diamine compound as an B agent are used. There is a spray method in which the B solution and the B solution are mixed at a volume ratio of about 1: 1.

As a method having a normal activity, carbodiimide-modified polyisocyanate and 4,4'-diphenylmethane diisocyanate (hereinafter referred to as 4,4'-MDI) described in JP-A-6-298896 are used. There is a method using a compound and a polyol. Here, MDI means diphenylmethane diisocyanate, and a numeral portion such as 2,2'-MDI indicates the position of an isocyanate group. As a super fast curing type,
There is a construction method for concrete corrosion prevention using an organic polyisocyanate, a high molecular weight polyamine and an aromatic polyamine chain extender having steric hindrance described in JP-A-8-238453.

[0006]

In this field, there is a demand for a potable time which does not hinder the mixing operation of the organic polyisocyanate and the active hydrogen compound and for rapid curing, and further, a high adhesive strength and a long term Is an important requirement. Among the organic polyisocyanates, M
DI is the vapor pressure, animal test data (eg, oral rat value),
This is preferable because it is considered to be less toxic than other isocyanates in terms of the allowable concentration in the working environment and carcinogenicity (eg, ranking of carcinogenicity by International Cancer Research Agency). However, M
In the case of DI, not only the urethane prepolymer alone but also the urethane prepolymer type easily crystallizes at the time of construction work at a low temperature, and the raw material must be kept warm or heated and melted in advance, which takes a lot of work. was there. Similarly, in the case of MDI alone, in the case of a urethane prepolymer type of a polyol and a urethane prepolymer alone, there is a possibility of crystallization due to the influence of the MDI as a raw material. Furthermore, the use of highly reactive amine-based raw materials or the use of a catalyst is an effective way to reduce the construction time at low temperatures and to eliminate the effects of moisture, but because of the rapid curing, both are two-component high-pressure sprays. Machine application port (gun tip)
It is difficult to correct because the surface is hardened immediately after the coating material is clogged, and it is difficult to correct it.Furthermore, carbon dioxide gas bubbles obtained by reacting even slightly with the moisture in the air, Entrapped foam and air bubbles dissolved in the raw material often remain in the pavement material or the coating material, and there is a problem that hardness is insufficient and long-term durability is lacking.

[0007]

Means for Solving the Problems Accordingly, the present inventors have:
As means for solving the above-mentioned problem when using an organic polyisocyanate and an active hydrogen compound as the coating material,
After diligent research, MD as a polyisocyanate
When I is used, carbodiimide-modified MDI having better low-temperature stability than 4,4'-MDI and 2,4'-diphenylmethane diisocyanate (hereinafter, referred to as 2,4'-MDI)
DI) and 2,2'-diphenylmethane diisocyanate (hereinafter abbreviated as 2,2'-MDI).
Using MDI (total amount of 4,4'-MDI and 2,4'-MDI and 2,2'-MDI) in combination with carbodiimide-modified type MDI;
The above-mentioned problems are caused by defining the content of 4'-MDI and the total content of 2,2'-MDI and 2,4'-MDI which are isomers of 4,4'-MDI in a specific ratio. The inventors have found that the points can be solved, and have reached the present invention.

That is, (Invention 1) an elastomer-forming property comprising a component (A) containing a polyisocyanate compound as a main component and a component (B) containing a high molecular weight active hydrogen compound and / or a chain extender as a main component. In the composition for spraying, the polyisocyanate compound (a) in the component (A) has a total of 2,2'-diphenylmethane diisocyanate and 2,4'-diphenylmethane diisocyanate of 2 to 60% by mass,
98 to 40 of 4'-diphenylmethane diisocyanate
% By weight of diphenylmethane diisocyanate (a
1) and a carbodiimide-modified polyisocyanate (a2) derived from diphenylmethane diisocyanate.

(Invention 2) An elastomer-forming spray comprising two components, component (A) containing a polyisocyanate compound as a main component and component (B) containing a high molecular weight active hydrogen compound and / or a chain extender as a main component. In the composition,
(A) The polyisocyanate compound (a) in the component is
2,2'-diphenylmethane diisocyanate and 2,2'-diphenylmethane diisocyanate
When the sum of 4'-diphenylmethane diisocyanate is 2 to
A diphenylmethane diisocyanate (a1) containing 60% by mass and 98 to 40% by mass of 4,4'-diphenylmethane diisocyanate and a carbodiimide-modified polyisocyanate (a2) derived from diphenylmethane diisocyanate and a mono- or polyoxyalkylene polyol (b1) The composition, which is a polyisocyanate compound obtained by reacting.

(Invention 3) The invention according to Invention 1 or 2, wherein the high molecular weight active hydrogen compound is a compound having an amino group and / or an imino group as an isocyanate-reactive group and having a number average molecular weight of 300 to 10,000. An elastomer-forming spray composition.

(Invention 4) The chain extender has a number average molecular weight of 300
The composition for an elastomer-forming spray according to any one of Inventions 1 to 3, which is less than the above.

(Invention 5) A polyurethane and / or polyurethane composition characterized by spraying and curing an elastomer-forming spray composition according to any one of Inventions 1 to 4 onto an object using a two-liquid high-pressure spray machine. Or a method for producing a polyurea elastomer.

(Invention 6) The elastomer-forming spray composition according to any one of Inventions 1 to 4 is sprayed and hardened on concrete using a two-liquid high-pressure spray machine, and is cured with a polyurethane of 0.3 to 10 mm and / or polyurethane. Alternatively, a method for producing an elastomer coating, comprising forming a polyurea elastomer coating.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION Further, the present invention will be described in detail. The polyisocyanate compound (a), which is the main component of the component (A), includes MDI (a1) having a relatively large amount of 2,2′-MDI and 2,4′-MDI, polyisocyanate (a2) obtained by modifying MDI with carbodiimide, And a mono- or polyoxyalkylene polyol (b1) to be reacted therewith.

In the ratio of (a1) and (a2), (a
If the ratio of 1) exceeds 80% by mass, solidification may occur due to its high crystallinity, resulting in poor workability. In addition, hardness is insufficient due to bifunctionality, and long-term durability is deteriorated.

When the total amount of 2,2'-MDI and 2,4'-MDI in (a1) is 2% by mass or less, the ratio of 4,4'-MDI becomes relatively high, and , 4'-M
DI is easier to crystallize than 2,2'-MDI and 2,4'-MDI, so that the effect of solidification (crystallization) at low temperatures is stronger, and that of 4,4'-MDI is 2,2. '-M
Since the reaction between DI and water is faster than that of 2,4'-MDI, foaming is apt to occur, resulting in poor appearance of the elastomer film and insufficient long-term durability, which is not preferable. On the other hand, at 60% by mass or more, 2,2'-MDI and 2,4'-MDI
4'-MDI is not preferred because of its molecular structure being more flexible, so that its strength is hardly developed and its durability is inferior.

If the amount is small, polymethylene polyphenylene polyisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate,
And an aromatic polyisocyanate other than MDI such as a mixture thereof (TDI), an xylylene diisocyanate, an aliphatic diisocyanate such as tetramethylene diisocyanate, hexamethylene diisocyanate, 3-methyl-1,5-pentane diisocyanate, and lysine diisocyanate; Further, alicyclic diisocyanates such as isophorone diisocyanate, hydrogenated tolylene diisocyanate, hydrogenated xylene diisocyanate, hydrogenated diphenylmethane diisocyanate, and tetramethyl xylene diisocyanate can also be used.

These isocyanate groups (hereinafter referred to as NCO
Abbreviated groups), modified products such as biuret, allophanate, isocyanurate (trimer), uretdione (dimer), carbodiimide, uretonimine, and those modified with oxazolidone, amide, imide, etc. can do. These can be used alone or as a mixture of two or more.

As the mono- or polyoxyalkylene polyol (b1) to be reacted with the polyisocyanates (a1) and (a2), those having a number average molecular weight of 40 to 10,000 are used. If the number average molecular weight is less than 40, the urethane group concentration increases, and strength or hardness is developed,
The viscosity of the NCO-terminated urethane prepolymer increases,
Poor mixing during operation. On the other hand, when the number average molecular weight is 1
Conversely, if it is larger than 000, the urethane group concentration becomes low, and the adhesive strength to the adherend and the durability are insufficient, which is not preferable. More preferred molecular weight from the physical properties and viscosity is 500 to
5000, further 800-3000.

The number of functional groups of the mono- or polyoxyalkylene polyol (b1) is 1 to 5, and more preferably about 2 to 3 in view of the balance between the viscosity and physical properties of the prepolymer. It is necessary that the compounding ratio of the polyisocyanate and the mono or polyol is NCO / OH = 1.5 to 300 in equivalent ratio to allow both to react.

The prepolymerization reaction is carried out with an excess of isocyanate groups based on the hydroxyl groups of the mono- or polyoxyalkylene polyol. At that time, (a1), (a2), (b)
The whole amount of 1) may be reacted at once, or (a1)
A part of (a2) may be reacted with (b1), and then the remaining (a1) and (a2) may be added for adjustment. The prepolymerization reaction is carried out by adding a mono- or polyoxyalkylene polyol (b1) to an isocyanate comprising all or a part of (a1) and (a2), heating the mixture to 50 to 90 ° C., and stirring for several hours. Will be When it is desired to accelerate the reaction, a urethanation catalyst may be used.

The mono- or polyoxyalkylene polyol used in the prepolymerization can be obtained by using a compound shown below as an initiator to obtain one or more known monomers such as ethylene oxide, propylene oxide, glycidyl ether and methyl glycidyl ether. It can be obtained by addition polymerization according to the method, and can be used alone or as a mixture of two or more.

The polyol used for the prepolymer is:
It may contain a monol, and in that case, it can be used as a material which exhibits a viscosity reducing effect by reacting with an organic polyisocyanate because of its low viscosity itself, like a diluent described later.

Examples of the initiator for the mono- or polyoxyalkylene polypolyol include mono- or diols such as methyl alcohol, ethyl alcohol, ethylene glycol and trimethylolpropane; diamines such as ethylene diamine and propylene diamine; monoethanolamine; Bifunctional amino alcohols such as methyldiethanolamine, ethylene glycol monobutyl ether,
Glycol ethers such as diethylene glycol monobutyl ether can be used alone or as a mixture of two or more.

Polyisocyanate and number average molecular weight of 40
The NCO content of the NCO-terminated urethane prepolymer by reaction with up to 10,000 mono- or polyoxyalkylene polyols is preferably 5-33% by weight,
28 mass% is more preferable, and 10 to 24 mass% is particularly preferable.

The component (A) containing the polyisocyanate compound (a) as a main component may contain a diluent or a flame retardant, which will be described later, in order to adjust the viscosity and adjust the compounding ratio.

The high molecular weight active hydrogen compound constituting the component (B) is a compound having two or more isocyanate-reactive groups and having a number average molecular weight of 400 to 10,000. Examples of the isocyanate-reactive group include a hydroxyl group, an amino group, and an imino group.

Examples of the hydroxyl group-containing high molecular weight active hydrogen compound include the aforementioned polyoxyalkylene polyols and polyester polyols. For quick curing, in the case of a polyoxyalkylene polyol, a polyoxyethylene oxypropylene polyol having a primary terminal is preferred. Also, a so-called polymer polyol in which an ethylenic polymer is grafted in a polyoxyalkylene polyol can be used. Furthermore, polytetramethylene ether glycol can also be used. Examples of the polyester polyol include those obtained by condensation of an acid component and a polyol component, and polycaprolactone polyl obtained by ring-opening polymerization of lactone.

Examples of the amino group-containing high molecular weight active hydrogen compound include polyoxyalkylene polyamines in which terminal hydroxyl groups of polyether polyol are substituted with amino groups. As polyoxypropylene diamine, for example,
Jeffamine D-2000 (manufactured by Huntsman Specialty Chemicals, amine value: about 56); Jeffamine T-5 as polyoxypropylene triamine
000 (manufactured by Huntsman Specialty Chemicals, amine value: about 34).

As the chain extender constituting the component (B),
Low molecular weight diols such as ethylene glycol, propylene glycol, 1,4-butanediol, 1,5
-Pentanediol, 1,6-hexanediol, diethylene glycol, dipropylene glycol, tripropylene glycol and the like can be used. Also, alkanolamines such as triethanolamine and diethanolamine can be used. Further, aromatic polyamines having steric hindrance can also be suitably used. For example, 1,3-dimethyl-2,4-diaminobenzene, 1,3-diethyl-
2,4-diaminobenzene, 1,3-dimethyl-2,6
-Diaminobenzene, 1,4-diethyl-2,5-diaminobenzene and the like. Further, a modified polyamine in which some primary amino groups of the aromatic diamine have been secondaryized by a Michael addition reaction with the unsaturated hydrocarbon compound can also be used.

The molar ratio between the high molecular weight active hydrogen compound and the chain extender is selected in the range of 1: 0.3 to 1: 3. When the amount of the chain extender is 0.3 or less, the film is extremely soft and semi-adhesive, which is not practical.

When a short curing time is required, a polyurea system in which both a high molecular weight active hydrogen compound and a chain extender are polyamino compounds is preferred.

In the case of a binary system of the polyisocyanate component (A) and the active hydrogen compound (B), the equivalent ratio of NCO group /
It is preferable to use active hydrogen groups in the range of 0.8 to 1.3.

[0034] A flame retardant may be added to the composition of the present invention. The flame retardant may be added to either the component (A) or the component (B).
It must not react with the group. Examples of flame retardants include quaternary phosphonium compounds, organic phosphates, organic phosphites, organic phosphonates, halogenated phosphoric esters,
Halides (aliphatic and aromatic hydrocarbons, alcohols, esters, ethers, etc.), antimony trioxide and the like. For example, Hoechst's Hostaflam-A
P422, AP423, Bayer's Levagard
4090N, FYROL- by Stouffer Chemical
6, FYROL-PCF and the like.

As the diluent which can be added to the component (A), any diluent which does not react with the NCO group and which is effective for lowering the viscosity of the component (A) can be used. Specifically, diesters of aromatic or aliphatic dibasic acids, acetates of mono- or polyhydric alcohols, alkylene carbonates, ethers, cyclic esters, acid anhydrides, various acrylic acids Esters and methacrylic esters can be exemplified.

In order to adjust the reactivity between the two components of the component (A) containing a polyisocyanate compound as a main component and the component (B) containing an active hydrogen compound as a main component, triethylamine, triethylenediamine, N-methyl Morpholine,
Amine catalysts such as N-methylimidazole, pyridine, α-picoline and N, N′-dimethylethanolamine;
Amine catalysts having an active hydrogen such as N-methyldiethanolamine, triethanolamine, N, N, N'-trimethylaminoethyl-ethanolamine (alkanolamine compounds), and dibutyltin dilaurate, dioctyltin dilaurate, calcium naphthenate; Metal catalysts such as tin octylate and zinc octylate can also be used.

In the present invention, in addition to the above-mentioned catalysts, colorants, antioxidants, stabilizers such as heat-resistance imparting agents, fillers, coupling agents, defoamers, surfactants, dispersants, thickeners And other various additives can also be added.

The coating material of the present invention is obtained by applying and curing using a two-liquid high-pressure spray machine. As the two-liquid high-pressure sprayer used in the present invention, for example, H-2000 type and H-3500 type manufactured by Gasmer and T-3 type manufactured by Glasscraft are preferable, and the spraying can be performed at a discharge pressure of 6 to 12 MPa. Further, as a coating gun suitable for this spraying machine, for example, GX-7 gun manufactured by Gasmer, prober gun manufactured by Glasscraft, or the like can be used.

The application method is to spray or apply the primer on the object to be coated, if necessary, and then spray the composition of the present invention with the above high-pressure spray machine. Since the present invention does not contain a solvent, it is possible to obtain an elastomer film having a desired thickness by a single blow, or to continuously laminate. In the case of the polyurea system, the reaction is so rapid that the tackiness is lost after 1-2 minutes and the curing is completed after several hours.

[0040]

EXAMPLES Examples of the present invention will be described below in detail, but the present invention is not limited to these examples. Unless otherwise specified, “parts” and “%” in Examples and Comparative Examples are “parts by mass” and “% by mass”, respectively.
Is shown.

[Synthesis Examples] Polyisocyanates A to H
MDI and carbodiimide-modified MDI shown in Tables 1 and 2 were combined with a polyol, heated to 80 ° C., and reacted for 3 hours to obtain an NCO-terminated prepolymer. Here, polyisocyanate A is a diluent -R (diisodecylphthalic acid), and polyisocyanate C is a flame retardant-
S (Tris [beta-chloropropyl] phosphate)
Was used. Tables 1 and 2 show raw materials, amounts used, and analytical values of the polyisocyanates A to H.

[Raw material for synthesizing polyisocyanate] MDI-1: NCO content = 33.5% Total of 2,2′-MDI and 2,4′-MDI = 50% 4,4′-MDI = 50% MDI- 2: NCO content = 33.5% Total of 2,2′-MDI and 2,4′-MDI = 28% 4,4′-MDI = 72% MDI-3: NCO content = 33.5% 2,2 Total of '-MDI and 2,4'-MDI = 7% 4,4'-MDI = 93% Carbodiimide-modified MDI: NCO content = 29.0% MDI with 4,4'-MDI = 99.8% MDI-4 modified with a catalyst and carbodiimide: NCO content = 33.6% Total of 2,2'-MDI and 2,4'-MDI = 0.4% 4,4'-MDI = 99.6% MDI-5: NCO content = 33.5% with 2,2′-MDI , 4'-MDI Total = 50% 4,4'-MDI = 50% MDI-6: sum of NCO content = 33.6% 2,2'-MDI and 2,4'-MDI = 99.6
% 4,4'-MDI = 0.4% Polyol-1: Number average molecular weight = 400, number of functional groups = 3
(Sannicks Trial G-40 manufactured by Sanyo Chemical Industries, Ltd.
0) Polyol-2: number average molecular weight = 2,000, number of functional groups = 2 (Sanix Diol PP-2 manufactured by Sanyo Chemical Industries, Ltd.)
000) Polyol-3: number-average molecular weight = 3,000, number of functional groups = 2 (Sanix Diol PP-3 manufactured by Sanyo Chemical Industries, Ltd.)
000) Polyol-4: number average molecular weight = 6,000, number of functional groups = 4 (Sannicks FA-702 manufactured by Sanyo Chemical Industries, Ltd.)

[0043]

[Table 1]

[0044]

[Table 2]

[Examples 1 to 5] The polyisocyanate components shown in Table 1 were mixed under the mixing conditions shown in Table 3 by using a two-liquid high-pressure spray machine “H-2000 type manufactured by Gasmer Co.”
At 0 to 22 ° C, a spray coating was formed on concrete at a thickness of 1 to 1.5 mm. The active hydrogen compounds shown in Tables 3 and 4 are as described below. Low temperature stability of isocyanate component,
The physical properties of the coating and the workability of coating were measured and evaluated by the test methods described below.

[Comparative Examples 1 to 4] Coatings were prepared under the same conditions as in the Examples under the blending conditions shown in Table 4 with the polyisocyanate components shown in Table 2, and the low-temperature stability and physical properties of the coatings were tested under the same conditions. . Table 4 shows the results. The polyisocyanate components E and H could not be tested as Comparative Examples 1 and 4, respectively, due to crystallization and poor low-temperature stability.

High molecular weight active hydrogen compound Active hydrogen compound -W: polyoxypropylene triamine (amine value = 34) Active hydrogen compound -Y: polyoxypropylene diamine (amine value = 56) Active hydrogen compound -Z: polyoxyalkylene triol (Hydroxyl value = 55) Chain extender Ethylene glycol Ethacure-100: Diethyl tolylenediamine Catalyst Amine catalyst: N, N, N ', N',-tetramethylhexamethylenediamine Metal catalyst: Dibutyltin dilaurate

[Test Method] (1) Low-temperature stability The polyisocyanate composition was allowed to stand for one month under the condition of -10 ° C., and its appearance was checked. Considering that it was necessary, it was judged as "poor", and when no crystal was generated, it was judged as "good". (2) Physical properties of coating film After leaving the coating film at 25 ° C. and 60 RH% for 10 days, J
According to IS K6301, the tensile strength at break and the elongation at that time were measured. (3) Coating workability The touch-drying time was the number of seconds at which tackiness was lost, the initial toughness was evaluated by 樹脂 for resin strength development after 1 minute of spraying, and the 先 was evaluated for gun tip clogging.

[0049]

[Table 3]

[0050]

[Table 4]

[0051]

As described above, the production of an elastomer coating using the composition of the present invention can be carried out even at a low temperature, foaming due to reaction with water is unlikely to occur, and such bubbles and entrained bubbles during stirring are produced. However, it does not stay in the coating but has good appearance and excellent durability. Further, the number of times of spray gun clogging is small due to appropriate reactivity.

Continued on front page F-term (reference) 4J034 BA08 CA04 CA05 CA13 CA15 CA17 CB03 CB04 CB05 CB07 CB08 CC03 CC08 CC12 CC61 CC65 DA01 DA02 DA03 DB01 DB03 DB07 DF01 DF11 DF14 DG01 DG03 DG04 DG06 DG08 HA07B06 HA07 HB08 HB09 HC03 HC12 HC17 HC22 HC34 HC35 HC46 HC52 HC61 HC63 HC64 HC67 HC71 HC73 JA42 KA01 KB02 KC07 KC08 KC17 KD02 KD12 KE02 PA05 QA05 QB13 QB15 QD06 RA10 4J038 DG051 DG131 DG141 DG281 PB05 PC04 PC04 PC04

Claims (6)

[Claims] An elastomer-forming spray composition comprising a component (A) containing a polyisocyanate compound as a main component and a component (B) containing a high molecular weight active hydrogen compound and / or a chain extender as a main component. In the polyisocyanate compound (a) in the component (A), the total of 2,2'-diphenylmethane diisocyanate and 2,4'-diphenylmethane diisocyanate is 2 to 60% by mass,
98 to 40 of 4'-diphenylmethane diisocyanate
% By weight of diphenylmethane diisocyanate (a
1) and a carbodiimide-modified polyisocyanate (a2) derived from diphenylmethane diisocyanate. 2. An elastomer-forming spray composition comprising a component (A) containing a polyisocyanate compound as a main component and a component (B) containing a high molecular weight active hydrogen compound and / or a chain extender as a main component. In the polyisocyanate compound (a) in the component (A), the total of 2,2'-diphenylmethane diisocyanate and 2,4'-diphenylmethane diisocyanate is 2 to 60% by mass,
98 to 40 of 4'-diphenylmethane diisocyanate
% By weight of diphenylmethane diisocyanate (a
1) and a polyisocyanate compound obtained by reacting a carbodiimide-modified polyisocyanate (a2) derived from diphenylmethane diisocyanate with a mono- or polyoxyalkylene polyol (b1). 3. The method according to claim 1, wherein the high molecular weight active hydrogen compound is a compound having an amino group and / or an imino group as the isocyanate-reactive group and having a number average molecular weight of 300 to 10,000. Elastomer-forming spray compositions. 4. The composition according to claim 1, wherein the chain extender has a number average molecular weight of less than 300. 5. A polyurethane and / or polyurethane composition, characterized in that the composition for spraying elastomer-forming according to any one of claims 1 to 4 is sprayed and cured on an object using a two-liquid high-pressure spray machine. A method for producing a polyurea elastomer. 6. The composition for spray forming an elastomer according to claim 1 is sprayed and hardened on concrete by using a two-part high-pressure spray machine to cure the composition.
A method for producing an elastomer coating, comprising forming a polyurethane and / or polyurea elastomer coating having a thickness of 3 to 10 mm.