Urea resin composition and polyurea foam

Abstract

To provide an urea resin composition capable of providing a polyurea foam having excellent fire retardancy and shape retention during firing, capable of suppressing temporal deterioration under moisture and heat environment, excellent in adhesion to an adherend during coating, difficult to cause crack in contact with flame, and difficult for carbonation to progress to the depth of the foam.SOLUTION: A urea resin composition comprising a polyisocyanate compound (A), a polyamine compound (B), a trimerization catalyst, a foaming agent, a foam stabilizer and a flame retardant, and a polyurea foam made by foaming the urea resin composition are provided.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a urea resin composition and a polyurea foam.

Background Art

[0002] Urethane foams are used as heat-insulating and insulating materials for building applications, ships for transporting oil and gas, and electrical appliances such as refrigerators. In particular, in buildings made of reinforced concrete, etc., a method of applying a urethane foam by a spraying method is used because the heat-insulating construction is easy. The spraying method is a method of spraying a urethane foam stock solution onto the building frame using a spraying device and simultaneously foaming it to form a urethane foam heat-insulating structure.

[0003] Generally, polyurethane resins are excellent in elasticity, flexibility, and tensile strength, and also exhibit excellent wear resistance and impact strength. However, since urethane foams alone have high flammability, studies have been made to improve the flame retardancy of urethane foams.

[0004] As such a urethane foam, Patent Document 1 discloses a water-foaming rigid polyisocyanurate foam-forming composition comprising an organic polyphenylmethane polyisocyanate, a polyol, a trimerization catalyst, water as a foaming agent, a foam stabilizer, and a flame retardant. The invention of Patent Document 1 is characterized in that the polyol contains a chlorinated polyether polyol having primary and / or secondary hydroxyl groups, which is obtained by using an active hydrogen-containing compound as a polymerization initiator and performing ring-opening polymerization of a chlorinated epoxy compound in the presence of an acid catalyst, and that the organic polyphenylmethane polyisocyanate and the polyol are blended so that the isocyanate index is 120 to 400. It has been shown that the urethane foam using the water-foaming rigid polyisocyanurate foam-forming composition of Patent Document 1 is excellent in the working environment and the flame retardancy.

[0005] Patent Document 2 discloses a flame-retardant urethane resin composition comprising a polyisocyanate compound, a polyol compound, a trimerizing catalyst, a blowing agent, a foam stabilizer, and an additive, wherein the trimerizing catalyst is at least one selected from the group consisting of nitrogen-containing aromatic compounds, alkali metal carboxylic acid salts, tertiary ammonium salts, and quaternary ammonium salts, and the additive is a combination of red phosphorus as an essential component and at least one selected from the group consisting of phosphate esters, phosphate-containing flame retardants, bromine-containing flame retardants, boron-containing flame retardants, antimony-containing flame retardants, and metal hydroxides in addition to red phosphorus. It has been shown that a urethane foam using this flame-retardant urethane resin composition of Patent Document 2 is easy to handle, has excellent flame retardancy, and can form a foam that maintains a certain shape when heated. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2013-023510 [Patent Document 2] Japanese Patent Publication No. 2017-075326 [Overview of the project] [Problems that the invention aims to solve]

[0007] The invention described in Patent Document 1 shows improved flame retardancy due to the use of urate bonds, but many urethane bonds are formed, which may mean that the flame retardancy is not sufficient. Furthermore, the invention described in Patent Document 2 describes how high flame retardancy is imparted by adding red phosphorus (powder) as a flame retardant and incorporating isocyanurate rings, but using a powder flame retardant may cause poor adhesion (lifting) to the substrate when applied by spray coating, for example, and there is a risk that the foam material may fall off or the thermal insulation performance may decrease over time. Patent Document 2 does not specifically address this point. Moreover, the inventions in Patent Documents 1 and 2 do not verify the deterioration over time due to temperature and humidity, which is important when used as thermal insulation material for building applications, oil and gas transport ships, and electrical appliances such as refrigerators, and there is a risk of deterioration over time in humid and hot environments. In addition to these, the inventions described in Patent Documents 1 and 2, when used for construction purposes, for example, may crack or the inside of the foam may carbonize when exposed to flames due to a fire, resulting in a significant decrease in strength and potentially causing the collapse of buildings.

[0008] Therefore, the object of the present invention is to provide a urea resin composition that can provide a novel foam different from urethane foam, and to provide the foam itself.

[0009] A second object of the present invention is to provide a urea resin composition and a foam thereof that can provide a polyurea foam having excellent flame retardancy and shape retention during combustion, suppressing deterioration over time in a humid and hot environment, having excellent adhesion to the substrate during coating, being resistant to cracking even when exposed to flame, and being resistant to carbonization from the surface to the depths due to flame exposure. [Means for solving the problem]

[0010] The inventors of this invention have diligently studied to achieve the above objectives and have found that a polyurea foam obtained by foaming a specific urea resin composition can solve the above problems, thus completing the present invention. That is, the present invention is as follows.

[0011] The present invention (1) is, This is a urea resin composition containing a polyisocyanate compound (A), a polyamine compound (B), a trimerizing catalyst, a blowing agent, a foam stabilizer, and a flame retardant. The present invention (2) is, This is a polyurea foam containing a flame retardant and having an isocyanurate structure. The present invention (3) is, A urea resin composition comprising a polyisocyanate compound (A), a polyamine compound (B), a trimerizing catalyst, a foaming agent, and a foam stabilizer, The urea resin composition does not contain polyol compounds, or the content of polyol compounds is 1 / 5 or less by mass ratio to the content of the polyamine compound (B). The present invention (4) is, This is a composition for producing polyurea foam, comprising a polyamine compound (B), a trimerizing catalyst, a blowing agent, a foam stabilizer, and a flame retardant. The present invention (5) is, A composition for producing polyurea foam comprising a polyamine compound (B), a trimerizing catalyst, a blowing agent, and a foam stabilizer, This is a composition for producing polyurea foam, which does not contain a polyol compound, or the content of a polyol compound is 1 / 5 or less by mass ratio to the content of the polyamine compound (B). The present invention (6) is, A urea resin composition comprising a polyisocyanate compound (A), a polyamine compound (B), a trimerizing catalyst, a blowing agent, a foam stabilizer, and a flame retardant, The content of the polyamine compound (B) is 2.0% by mass or more, when the total amount of the urea resin composition is considered to be 100% by mass. The urea resin composition is characterized in that the content of the trimerizing catalyst is 5 to 20 parts by mass when the content of polyamine compound (B) in the urea resin composition is 100 parts by mass. The present invention (7) is, This is a polyurea foam obtained by foaming and curing the urea resin composition of the above invention (6). The present invention (8) is, A polyurea foam having an isocyanurate structure, The polyurea foam is characterized in that its isocyanurate conversion rate is 25 to 50%. The isocyanurate conversion rate is a value calculated using the following formula (1) based on the absorption spectrum obtained by infrared spectroscopy of the polyurea foam. (Formula 1) Isocyanurate conversion rate (%) = P1 / (P1 + P2 + P3 + P4) × 100 P1: Peak area derived from the isocyanurate structure in the absorption spectrum of polyurea foam obtained by infrared spectroscopy. P2: Peak area originating from the C=O structure of the urea structure in the absorption spectrum of the polyurea foam obtained by infrared spectroscopy. P3: Peak area derived from the C=O structure of the urethane and isocyanurate structures in the absorption spectrum of the polyurea foam obtained by infrared spectroscopy. P4: Peak area derived from NH contained in the urethane and urea structures in the absorption spectrum of polyurea foam obtained by infrared spectroscopy.

[0012] Furthermore, the present invention may also be the following invention. The present invention (9) is, This is a polyurea foam having an isocyanurate structure and a 5% weight loss temperature of 175°C or higher. The 5% weight loss temperature is determined by using a differential thermal / thermogravimetric simultaneous thermometer to observe the weight loss behavior of the sample over a temperature range of 25-700°C with a heating rate of 10°C / min and a dry air flow, and measuring the temperature at which the sample weight decreases by 5% by weight. The present invention (10) is, A urea resin composition comprising a polyisocyanate compound (A), a polyamine compound (B), a trimerizing catalyst, a blowing agent, a foam stabilizer, and a flame retardant, The urea resin composition is characterized in that the content of the polyamine compound (B) is 2.0% by mass or more when the total amount of the urea resin composition is considered to be 100% by mass. The present invention (11) is The urea resin composition of the above invention (10), wherein the amine value of the polyamine compound (B) is 50 to 1000 mg KOH / g. The present invention (12) is The urea resin composition of the above invention (10) or (11), wherein the polyisocyanate compound (A) has an NCO% of 10 to 35%. The present invention (13) is The urea resin composition of any one of the above inventions (10) to (12), wherein the polyisocyanate compound (A) is an aromatic isocyanate. The present invention (14) is The urea resin composition of any one of the above inventions (10) to (13), wherein the flame retardant contains red phosphorus. The present invention (15) is The urea resin composition of any one of the above inventions (10) to (14), wherein the flame retardant contains at least one selected from phosphate esters, phosphate-containing flame retardants, bromine-containing flame retardants, boron-containing flame retardants, antimony-containing flame retardants, and metal hydroxides. The present invention (16) is A polyurea foam obtained by foaming and curing the urea resin composition of any one of the above inventions (10) to (15). The present invention (17) is The polyurea foam of the above invention (16), wherein the total heat release amount at 20 minutes measured under the condition of heating with a radiant heat intensity of 50 kW / m2 in accordance with the test method of ISO-5660 is 8.5 MJ / m2 or less. The present invention (18) is A polyurea foam having an isocyanurate structure. The present invention (19) is The polyurea foam of the above invention (18), characterized by containing a flame retardant. The present invention (20) is The polyurea foam of the above invention (18) or (19), characterized by containing red phosphorus. The present invention (21) is, The polyurea foam of invention (20) is characterized in that the red phosphorus content is 1 to 30% by mass when the total mass of the polyurea foam is 100% by mass. The present invention (22) is, The polyurea foam is a polyurea foam according to any of the above inventions (18) to (21), characterized in that the isocyanurate conversion rate is 10 to 50%. The isocyanurate conversion rate is a value calculated using the following formula (1) based on the absorption spectrum obtained by infrared spectroscopy of the polyurea foam. (Formula 1) Isocyanurate conversion rate (%) = P1 / (P1 + P2 + P3 + P4) × 100 P1: Peak area derived from the isocyanurate structure in the absorption spectrum of polyurea foam obtained by infrared spectroscopy. P2: Peak area originating from the C=O structure of the urea structure in the absorption spectrum of the polyurea foam obtained by infrared spectroscopy. P3: Peak area derived from the C=O structure of the urethane and isocyanurate structures in the absorption spectrum of the polyurea foam obtained by infrared spectroscopy. P4: Peak area derived from NH contained in the urethane and urea structures in the absorption spectrum of polyurea foam obtained by infrared spectroscopy. The present invention (23) is, The polyurea foam according to any one of the above inventions (18) to (22), characterized by containing at least one selected from phosphate esters, phosphate-containing flame retardants, bromine-containing flame retardants, boron-containing flame retardants, antimony-containing flame retardants, and metal hydroxides. [Effects of the Invention]

[0013] According to the present invention, a urea resin composition capable of providing a novel foam different from urethane foam, and the foam itself, can be provided.

[0014] Furthermore, according to the present invention, it is possible to provide a urea resin composition capable of providing a foam having sufficient flame retardancy and compressibility, and a foam thereof.

[0015] Furthermore, according to the present invention, it is possible to provide a urea resin composition and a foam thereof that have excellent flame retardancy and shape retention during combustion, can suppress deterioration over time in a humid and hot environment, have excellent adhesion to the substrate during coating, are resistant to cracking even when exposed to flame, and carbonization due to flame exposure does not easily progress from the surface to the depths. [Brief explanation of the drawing]

[0016] [Figure 1] This diagram illustrates a mold for molding a polyurea foam for observing the shape and average bubble diameter of the present invention, and the flow direction of the foam. [Modes for carrying out the invention]

[0017] 1.Urea resin composition The polyurea foam of the present invention has an isocyanurate structure. Furthermore, the polyurea foam is obtained by foaming and curing a urea resin composition. The urea resin composition of the present invention comprises a polyisocyanate compound (A), a polyamine compound (B), a trimerizing catalyst, and a blowing agent, and preferably a foam stabilizer and a flame retardant. In the following description, when upper and lower limits are stated separately, the upper and lower limits can be freely combined to create a new numerical range.

[0018] The urea resin composition of the present invention is characterized in that the content of polyamine compound (B) is 2.0% by mass or more when the total amount of the urea resin composition is 100% by mass.

[0019] The urea resin composition of the present invention can form a polyurea foam by foaming and curing.

[0020] 2. Raw materials for urea resin compositions 2-1. Polyisocyanate compound (A) The polyisocyanate compound (A) according to the present invention is not particularly limited as long as it does not inhibit the effects of the present invention. Examples of polyisocyanate compound (A) include monomer-type polyisocyanates and polymer-type polyisocyanates. A monomer-type polyisocyanate is a compound in which multiple isocyanate groups are present at the ends of the monomer structure. A polymer-type polyisocyanate is a compound in which multiple isocyanate groups are present at the ends of the polymer structure. These polyisocyanate compounds (A) can be used individually or in combination.

[0021] Monomer-type polyisocyanates include, for example, difunctional polyisocyanate compounds such as 2,4-toluene diisocyanate (2,4-TDI), 2,6-toluene diisocyanate (2,6-TDI), m-phenylenediisocyanate, p-phenylenediisocyanate, 4,4'-diphenylmethane diisocyanate (4,4'-MDI), 2,4'-diphenylmethanediisocyanate (2,4'-MDI), 2,2'-diphenylmethane diisocyanate (2,2'-MDI), hydrogenated MDI, xylylene diisocyanate, 3,3'-dimethyl-4,4'-biphenylenediisocyanate, and 3,3'-dimethoxy-4,4'-biphenylene. Aromatic compounds such as diisocyanates, polymethylene polyphenyl polyisocyanates, 1,5-naphthalene diisocyanate, xylylene diisocyanate (XDI), hydrogenated XDI, and tetramethylxylene diisocyanate (TMXDI); alicyclic compounds such as cyclohexane-1,4-diisocyanate, isophorone diisocyanate, dicyclohexylmethane-4,4'-diisocyanate, and methylcyclohexane diisocyanate; and alkylene compounds such as butane-1,4-diisocyanate, hexamethylene diisocyanate, isopropyl diisocyanate, methylene diisocyanate, and lysine diisocyanate; Examples of polyisocyanates with three or more functions include 1-methylbenzol-2,4,6-triisocyanate, 1,3,5-trimethylbenzol-2,4,6-triisocyanate, biphenyl-2,4,4'-triisocyanate, diphenylmethane-2,4,4'-triisocyanate, methyldiphenylmethane-4,6,4'-triisocyanate, 4,4'-dimethyldiphenylmethane-2,2',5,5'-tetraisocyanate, triphenylmethane-4,4',4"-triisocyanate, polymeric MDI, lysine ester triisocyanate, 1,3,6-hexamethylene triisocyanate, 1,6,11-undecane triisocyanate, bicycloheptane triisocyanate, 1,8-diisocyanatomethyloctane, etc. Furthermore, these modified forms, derivatives, etc., may be included. Examples of these modified forms and derivatives include isocyanurate compounds of diisocyanate compounds, adduct compounds of diisocyanate compounds, burette compounds of diisocyanate compounds, allophanate compounds of diisocyanate compounds, and carbodiimide-modified compounds of diisocyanate compounds. These polyisocyanate compounds can be used individually or in combination. Monomer-type polyisocyanate compounds form the urea skeleton of the polyurea foam, and can be freely selected considering the desired properties of the polyurea foam. Among these monomer-type polyisocyanates, aromatic isocyanates are preferred in terms of their excellent reactivity, MDI, or modified or derivative forms of MDI are more preferred, and monomeric MDI and crude MDI are even more preferred. When these preferred aromatic isocyanates are used as polyurea foam for spray application, their excellent reactivity makes them preferable in terms of safety in the work environment. Furthermore, among monomeric MDI and crude MDI having equivalent NCO%, crude MDI containing polynuclear compounds has superior isocyanuration rate and therefore superior flame retardancy.

[0022] Polymer-type polyisocyanate compounds include active hydrogen compounds having two or more active hydrogen groups, such as polyol compounds, and compounds obtained by prepolymerizing polyamine compounds (D) by reacting them with an excess amount of polyisocyanate compound (C). Note that polyamine compound (D) and polyisocyanate compound (C) are raw materials for producing polymer-type polyisocyanates and are not included in polyamine compound (B) and polyisocyanate compound (A), which are raw materials for the urea resin composition according to the present invention. Here, polyisocyanate compound (C) may be the same as or different from polyisocyanate compound (A).

[0023] Examples of such polyol compounds include polyester polyols and polyether polyols. Some polyester polyols are obtained by the condensation reaction of a polyhydric alcohol and a polyhydric carboxylic acid. Examples of polyhydric alcohols include ethylene glycol, propylene glycol, butanediol, butylene glycol, glycerin, and trimethylolpropane. Examples of polyhydric carboxylic acids include glutaric acid, adipic acid, maleic acid, phthalic acid, terephthalic acid, and isophthalic acid. These can be used individually or in combination. Furthermore, polyester polyols obtained by ring-opening condensation of caprolactone, methylvalerolactone, etc., can also be mentioned.

[0024] Examples of polyether polyols include those obtained by addition polymerization of ethylene oxide, propylene oxide, trimethylene oxide, or butylene oxide to polyhydric alcohols such as ethylene glycol, propylene glycol, diethylene glycol, glycerin, trimethylolpropane, or sorbitol. These can be used individually or in combination.

[0025] The polyisocyanate compound (B) to be reacted with these polyol compounds is not particularly limited as long as it does not inhibit the effects of the present invention, and examples include aliphatic or aromatic polyisocyanates, mixtures thereof, and modified polyisocyanates obtained by modifying them.

[0026] The polyamine compound (D) is not particularly limited as long as it does not inhibit the effects of the present invention. Examples of polyamine compound (D) include aliphatic polyamines such as triethylenetetramine, aromatic polyamines such as metaphenylenediamine, and alicyclic polyamines such as isophoronediamine. Specifically, examples include 4,4'-diamino-3,3'-dichlorodiphenylmethane, trimethylene-bis(4-aminobenzoate), 4,4'-diamino-3,3'-diethyl-5,5'-dimethyldiphenylmethane, polytetramethylene oxide-di-p-aminobenzoate, 2,2',6,6'-tetraethyl-4,4'-methylenedianiline, 4,4'-methylenebis(2-isopropyl-6-methylaniline), 4,4'-methylenebis(2,6-diisopropylaniline), 4,4'-methylenebis(3-chloro-2,6-diethylaniline), 3,5-diethyltoluene-2,4-diamine, and dimethylthiotoluenediamine. This can be used alone or in combination with other compounds. Furthermore, polyamine compound (D) may be the same as or different from polyamine compound (B) described later.

[0027] The NCO% of polyisocyanate compound (A) is not limited as long as it does not hinder the effects of the present invention, and can be, for example, 5 to 40%, preferably 10 to 35%, and more preferably 15 to 35%. When the NCO% of polyisocyanate compound (A) is high, a polyurea foam can be obtained that has high shape retention during combustion, low thermal conductivity, and can suppress deterioration over time in a humid heat environment. That is, a polyurea foam can be obtained that has excellent flame retardancy and shape retention during combustion, can suppress deterioration over time in a humid heat environment, and has excellent adhesion to the substrate when coated.

[0028] The NCO% (isocyanate content) of polyisocyanate compound (A) is measured in accordance with Method A (toluene / dibutylamine, hydrochloric acid method) of JIS K1603-1:2007 "Test methods for aromatic isocyanates in plastics - polyurethane raw materials Part 1: Method for determining isocyanate group content".

[0029] 2-2. Polyamine compounds (B) Polyamine compounds form urea bonds by reacting with isocyanates. Urea bonds offer excellent water resistance, corrosion resistance, and resistance to chemicals such as acids and alkalis.

[0030] The polyamine compound (B) is not particularly limited as long as it does not inhibit the effects of the present invention. Examples of polyamine compound (B) include aliphatic polyamines such as triethylenetetramine, aromatic polyamines such as metaphenylenediamine, and alicyclic polyamines such as isophoronediamine. Specifically, examples include 4,4'-diamino-3,3'-dichlorodiphenylmethane, trimethylene-bis(4-aminobenzoate), 4,4'-diamino-3,3'-diethyl-5,5'-dimethyldiphenylmethane, polytetramethylene oxide-di-p-aminobenzoate, 2,2',6,6'-tetraethyl-4,4'-methylenedianiline, 4,4'-methylenebis(2-isopropyl-6-methylaniline), and 4,4'-methylene Examples of commercially available products include bis(2,6-diisopropylaniline), 4,4'-methylenebis(3-chloro-2,6-diethylaniline), 3,5-diethyltoluene-2,4-diamine, and dimethylthiotoluenediamine. Examples of commercially available products include Ihara Cureamine MT, Ihara Cureamine M Liquid, CUA-4, Cure Hard MED, Elastomer 250P, and Elastomer 1000P from Kumiai Chemical Industry Co., Ltd.; Lonzacure M-DEA, Lonzacure M-MIPA, Lonzacure M-DIPA, and Lonzacure M-CDEA from Lonza Japan Co., Ltd.; Etacure 100, Etacure 300, Etacure 410, and Etacure 420 from Albemarle Co., Ltd.; VERSALINK 740 from Evonik Nutrition & Care Co., Ltd.; and ANCAMINE 2049 from Evonik. These can be used individually or in combination.

[0031] The amine value of polyamine compound (B) is not particularly limited as long as it does not inhibit the effects of the present invention, but for example it can be 50 to 1000 mg KOH / g, preferably 200 to 1000 mg KOH / g, more preferably 450 to 1000 mg KOH / g, and even more preferably 500 to 1000 mg KOH / g. When the amine value of the polyamine compound is within this range, a urea resin composition can be obtained that provides a polyurea foam having excellent flame retardancy and shape retention during combustion, suppressing deterioration over time in a humid and hot environment, having excellent adhesion to the substrate during coating, being resistant to cracking even when exposed to flame, and being resistant to carbonization from the surface to the depths due to flame exposure. In particular, in the total calorific value test using a cone calorimeter in accordance with the ISO-5660 standard (a test demonstrating flame retardancy, hereafter sometimes abbreviated as the cone calorimeter total calorific value test), the volume change rate at 600°C (a test demonstrating shape retention), and the flame contact test, as described later, it shows excellent effectiveness in forming a carbonized layer on the surface of the foam, preventing fire from penetrating deep into the foam.

[0032] The amine value of polyamine compound (B) can be measured by the method for measuring the total amine value described in JIS K1557-7:2011 "Plastics - Test methods for polyols used in polyurethane raw materials - Part 7: Determination of basicity (expression of nitrogen content and total amine value)".

[0033] In addition to the polyamine compound (B) of the present invention, an active hydrogen compound may be added, provided that it does not inhibit the effects of the present invention. Examples of active hydrogen compounds include alcohols such as primary alcohols, secondary alcohols, and tertiary alcohols, monools, polyol compounds, or thiol compounds. Alcohols and polyol compounds can react with the polyisocyanate compound (A) to form urethane bonds, which can form part of the backbone of the polyurea foam. However, since urethane bonds are more flammable than urea bonds, the flame retardancy of the polyurea foam may decrease. For this reason, the content of the polyol compound can be 1 / 5 or less by mass ratio of the content of the polyamine compound (B), preferably 1 / 10 or less, and it is more preferable that the polyol compound is not included.

[0034] 2-3. Trimerization catalyst The trimerizing catalyst according to the present invention is not particularly limited as long as it does not inhibit the effects of the present invention. By using the trimerizing catalyst, an isocyanurate structure can be formed in the polyurea foam when producing the polyurea foam using polyamine compound (B). Examples of trimerizing catalysts include metal oxides such as lithium oxide, sodium oxide, and potassium oxide. Alkoxides such as sodium methoxy, sodium ethoxy, sodium propoxy, sodium butoxy, potassium methoxy, potassium ethoxy, potassium propoxy, and potassium butoxy; Organometallic salts such as potassium acetate, potassium octylate, potassium caprylate, and iron oxalate; Tertiary amines such as 2,4,6-tris(dimethylaminomethyl)phenol, N,N',N''-tris(dimethylaminopropyl)hexahydrotriazine, triethylenediamine, and 1,3,5-tris(dimethylaminopropyl)hexahydro-s-triazine; derivatives of ethyleneimines; Chelates of alkali metals, aluminum, and transition metals with acetylacetone; Examples include quaternary ammonium salts; such as diazabicycloundecene (DBU). These can be used individually or in combination. Of these, it is more preferable to use tertiary amines, organometallic salts, and diazabicycloundecene. By using these suitable trimerization catalysts, a polyurea foam can be obtained that has excellent flame retardancy and shape retention during combustion, can suppress deterioration over time in a humid and hot environment, and has excellent adhesion to the substrate during coating.

[0035] 2-4. Foaming agent The foaming agent according to the present invention is not particularly limited as long as it does not hinder the effects of the present invention. Examples of foaming agents include water, hydrocarbons (preferably C4-C6), hydrofluoroolefins, and carbon dioxide. Specifically, examples include cyclopentane, HFO(1336mzz), and HFO(1233zd). These can be used individually or in combination.

[0036] 2-5. Foam stabilizers The foam stabilizer according to the present invention is not particularly limited as long as it does not hinder the effects of the present invention. Examples of foam stabilizers include silicone compounds and nonionic surfactants. These can be used individually or in combination.

[0037] 2-6. Flame retardants The urea resin composition according to the present invention may contain a flame retardant. The flame retardant is not particularly limited as long as it does not inhibit the effects of the present invention, but examples include red phosphorus, phosphate esters, phosphate-containing flame retardants, bromine-containing flame retardants, boron-containing flame retardants, antimony-containing flame retardants, and metal hydroxides. These can be used individually or in combination. Of these, it is preferable to include at least one selected from red phosphorus or phosphate ester, phosphate-containing flame retardant, bromine-containing flame retardant, boron-containing flame retardant, antimony-containing flame retardant, and metal hydroxide; it is more preferable to include red phosphorus; it is even more preferable to include at least one selected from phosphate ester, phosphate-containing flame retardant, bromine-containing flame retardant, boron-containing flame retardant, antimony-containing flame retardant, and metal hydroxide in addition to red phosphorus; it is particularly preferable to include red phosphorus and phosphate ester, and further to include at least one selected from chlorine-containing phosphate ester, phosphate-containing flame retardant, bromine-containing flame retardant, boron-containing flame retardant, antimony-containing flame retardant, and metal hydroxide; and it is particularly preferable to include red phosphorus, phosphate ester, and bromine-containing flame retardant. When the urea resin composition according to the present invention contains these flame retardants, it is possible to obtain a polyurea foam that has excellent flame retardancy and shape retention during combustion, can suppress deterioration over time in a humid and hot environment, and has excellent adhesion to the substrate during coating. Furthermore, it may include other flame retardants besides those listed above.

[0038] The phosphate esters used in this invention are not particularly limited as long as they do not inhibit the effects of the present invention. Examples of phosphate esters include aromatic phosphate esters such as triphenyl phosphate, cresyl diphenyl phosphate, tricresyl phosphate, trixylenyl phosphate, tris(t-butylated phenyl) phosphate, tris(i-propylated phenyl) phosphate, and 2-ethylhexyl diphenyl phosphate; Aromatic condensed phosphate esters such as 1,3-phenylenebis(diphenyl phosphate), 1,3-phenylenebis(dixylenyl) phosphate, resorcinolbis(diphenyl) phosphate, and bisphenol A bis(diphenyl phosphate); Halogenated phosphate esters such as tris(dichloropropyl)phosphate, tris(β-chloropropyl)phosphate, and tris(chloroethyl)phosphate; Examples include halogen-containing condensed phosphate esters such as 2,2-bis(chloromethyl)trimethylenebis(bis(2-chloroethyl)phosphate) and polyoxyalkylene bisdichloroalkyl phosphates. These can be used individually or in combination.

[0039] The phosphate-containing flame retardant according to the present invention is not particularly limited as long as it does not inhibit the effects of the present invention. Examples of phosphate-containing flame retardants include ammonium salts such as ammonium phosphate, ammonium dihydrogen phosphate, and diammonium hydrogen phosphate as monophosphates; Sodium salts such as monosodium phosphate, disodium phosphate, trisodium phosphate, monosodium phosphate, disodium phosphate, and sodium hypophosphate; Potassium salts such as monopotassium phosphate, dipotassium phosphate, tripotassium phosphate, monopotassium phosphite, dipotassium phosphite, and potassium hypophosphite; Lithium salts such as monolithium phosphate, dilithium phosphate, trilithium phosphate, monolithium phosphate, dilithium phosphate, and hypolithium phosphate; Barium salts such as barium dihydrogen phosphate, barium hydrogen phosphate, tribarium phosphate, and barium hypophosphite; magnesium salts such as magnesium monohydrogen phosphate, magnesium hydrogen phosphate, trimagnesium phosphate, and magnesium hypophosphite; Calcium salts such as calcium dihydrogen phosphate, calcium hydrogen phosphate, tricalcium phosphate, and calcium hypophosphate; Examples include zinc salts such as zinc phosphate, zinc phosphite, and zinc hypophosphite, and aluminum salts such as monoaluminum phosphate, dialuminum phosphate, trialuminum phosphate, aluminum phosphite, and aluminum hypophosphite. Examples of polyphosphates include ammonium polyphosphate, piperazine polyphosphate, melamine polyphosphate, ammonium polyphosphate amide, and aluminum polyphosphate. These can be used individually or in combination.

[0040] The bromine-containing flame retardant according to the present invention is not particularly limited as long as it does not hinder the effects of the present invention. Examples of bromine-containing flame retardants include pentabromodiphenyl ether; octabromodiphenyl ether; decabromodiphenyl ether; TBBA compounds such as tetrabromobisphenol A (TBBA), TBBA-epoxy oligomer, TBBA-polycarbonate oligomer, TBBA-bis(dibromopropyl ether), and TBBA-bis(aryl ether); Polybenzene ring compounds such as bisphenylpentamethane, 1,2-bis(2,4,6-tribromophenoxy)ethane, 2,4,6-tris(2,4,6-tribromophenoxy)-1,3,5-triazine, 2,6-dibromophenol, and 2,4-dibromophenol; Brominated styrene compounds such as brominated polystyrene and polybrominated styrene; Phthalate compounds such as ethylenebistetrabromophthalimide; Examples include cyclic aliphatic compounds such as hexabromocyclododecane; and polyacrylic acid brominated aromatic ester compounds such as poly(pentabromophenyl acrylate). These can be used individually or in combination.

[0041] The boron-containing flame retardant according to the present invention is not particularly limited as long as it does not hinder the effects of the present invention. Examples of boron-containing flame retardants include borax; boron oxides such as diboron trioxide, boron trioxide, diboron dioxide, tetraboron trioxide, and tetraboron pentoxide; and boric acid compounds such as boric acid, lithium borate, sodium borate, potassium borate, cesium borate, magnesium borate, calcium borate, barium borate, zirconium borate, zinc borate, aluminum borate, and ammonium borate.

[0042] The antimony-containing flame retardant according to the present invention is not particularly limited as long as it does not hinder the effects of the present invention. Examples of boron-containing flame retardants include antimony oxides such as antimony trioxide and antimony pentoxide; antimonate salts such as sodium antimonate and potassium antimonate; and pyroantimonate salts such as sodium pyroantimonate and potassium pyroantimonate. These can be used individually or in combination.

[0043] The metal hydroxide used in this invention is not particularly limited, as long as it does not hinder the effects of the present invention. Examples of metal hydroxides include aluminum hydroxide and magnesium hydroxide. These can be used individually or in combination.

[0044] Other flame retardants that can be used include known flame retardants. Examples of other flame retardants include chlorine compounds such as chlorinated paraffins; nitrogen compounds such as hindered amines and melamine cyanurate; cellulose; and so on. These can be used individually or in combination.

[0045] 2-7. Other additives The resin composition according to the present invention may contain other additives in addition to the above-mentioned additives, as long as they do not impair the effects of the present invention. Other additives that can be added include resin (urea) catalysts, foaming catalysts, balancing catalysts, antioxidants, ultraviolet absorbers, antibacterial agents, dispersants, and other known additives.

[0046] 3. Properties of Urea Resin Compositions The cream time of the urea resin composition according to the present invention at 5°C can be 1 to 120 seconds, and preferably 2 to 70 seconds. When the cream time of the urea resin composition at 5°C falls within this range, it exhibits superior effects in terms of obtaining sufficient liquid flowability and wettability / adhesion to the structure. Here, cream time refers to the time from the moment when the mixture of all components of the urea resin composition except for the polyisocyanate compound (A) (hereinafter sometimes referred to as the polyurea foam manufacturing composition) is mixed with the polyisocyanate compound (A), until just before these components begin to foam, become a creamy liquid, and begin to expand. It is measured by visual inspection as the time when the color of the mixture solution begins to change. Note that 5°C refers to the time when the polyisocyanate compound (A) and the polyurea foam manufacturing composition are mixed while each is kept at 5°C.

[0047] The cream time of the urea composition of the present invention at 20°C can be 0.5 to 90 seconds, and preferably 0.7 to 60 seconds. When the cream time of the urea resin composition at 20°C falls within this range, it exhibits a superior effect in that the mixed liquid thickens before the foaming agent volatilizes at practical liquid temperatures, preventing cell collapse and allowing for efficient foaming. The cream time of the urea composition at 20°C is measured using the same measurement method as the method for measuring the cream time at 5°C, except that the polyisocyanate compound (A) and the polyurea foam production composition are kept at 20°C and mixed.

[0048] 4. Properties of polyurea foam 4-1. Isocyanuration rate The polyurea foam of the present invention contains an isocyanurate structure. The isocyanurate structure is formed when a polyisocyanate compound (A), which is a raw material for the urea resin composition, is trimerized by a trimerization catalyst. The isocyanurate structure can be detected by infrared spectroscopy. The percentage of polyisocyanate compound (A) that has been isocyanurated (isocyanuration rate) is calculated by the following formula (1) based on the absorption spectrum obtained by infrared spectroscopy. The isocyanuration rate is not particularly limited as long as it does not hinder the effects of the present invention, but for example it can be 10 to 50%, preferably 20 to 45%, and more preferably 25 to 40%. The lower limit can be 10% or more, 20% or more, 25% or more, or 28% or more, and the upper limit may be 50% or less, 45% or less, 43% or less, or 40% or less. If the isocyanuration rate is within this range, the polyurea foam has excellent flame retardancy. (Formula 1) Isocyanurate conversion rate (%) = P1 / (P1 + P2 + P3 + P4) × 100 P1: Peak area derived from the isocyanurate structure in the absorption spectrum of polyurea foam obtained by infrared spectroscopy. P2: Peak area originating from the C=O structure of the urea structure in the absorption spectrum of the polyurea foam obtained by infrared spectroscopy. P3: Peak area derived from the C=O structure of the urethane and isocyanurate structures in the absorption spectrum of the polyurea foam obtained by infrared spectroscopy. P4: Peak area derived from NH contained in the urethane and urea structures in the absorption spectrum of polyurea foam obtained by infrared spectroscopy.

[0049] P1 represents the area of ​​the peak originating from the isocyanurate structure in the absorption spectrum of the polyurea foam obtained by infrared spectroscopy, and is the area of ​​the peak originating from the nulate ring near wavenumber 1410 cm⁻¹. P1 represents the peak area in the wavenumber range of 1380 to 1430 cm⁻¹. P1 indicates the content of the isocyanurate structure formed by the reaction of the isocyanate groups of the raw material polyisocyanate compound (A).

[0050] P2 is the peak area originating from the C=O of the urea structure in the absorption spectrum of the polyurea foam obtained by infrared spectroscopy, and is the area of ​​the peak originating from the C=O of the urea bond near wavenumber 1595 cm⁻¹. P2 is the peak area in the wavenumber range of 1550 to 1640 cm⁻¹. P2 indicates the content of the urea structure formed by the reaction of the isocyanate group of the raw material polyisocyanate compound (A).

[0051] P3 represents the peak area originating from the C=O bond in the urethane and isocyanurate structures in the absorption spectrum of the polyurea foam obtained by infrared spectroscopy, and is the area of ​​the C=O bond peak near wavenumber 1710 cm⁻¹. P3 represents the peak area in the wavenumber range of 1680 to 1730 cm⁻¹. P3 indicates the content of the urethane and isocyanurate structures formed by the reaction of the isocyanate groups of the raw material polyisocyanate compound (A).

[0052] P4 is the peak area derived from NH contained in the urethane and urea structures in the absorption spectrum of the polyurea foam obtained by infrared spectroscopy, and is the area of ​​the peak derived from NH near wavenumber 1510 cm⁻¹. P4 is the peak area in the wavenumber range of 1470 to 1550 cm⁻¹. P4 indicates the content of urethane and urea structures contained in the polyurea foam, and indicates the content of urethane and urea structures formed by the reaction of isocyanate groups of the raw material polyisocyanate compound (A).

[0053] Therefore, the sum of P1 to P4 represents the total number of isocyanate groups that reacted with the starting material polyisocyanate compound (A). Thus, the isocyanuration rate is a value that indicates the proportion of isocyanate groups in the reacted starting material polyisocyanate compound (A) that became an isocyanurate structure.

[0054] 4-2.Density The density of the polyurea foam is not particularly limited as long as it does not hinder the effects of the present invention, but can be 10 to 200 kg / m³, preferably 10 to 100 kg / m³, and more preferably 10 to 55 kg / m³. When the density of the polyurea foam is within this range, a polyurea foam with excellent thermal conductivity and flame retardancy can be obtained. The density of the polyurea foam is measured according to JIS K7222:2005 "Foamed plastics and rubber - Method for determining apparent density".

[0055] 4-3. Average cell (bubble) diameter and cell shape The average cell diameter and shape of the air bubbles (cells) contained in the polyurea foam are observed and measured using an optical microscope with a length-measuring function (e.g., a digital microscope) after preparing the following test specimens. The test specimens are prepared by pouring the urea resin composition into a box-shaped mold (e.g., a mold for molding foam into a rectangular parallelepiped shape), foaming and curing it to obtain a molded polyurea foam, and then cutting out a piece from this polyurea foam measuring 50 mm in length, 50 mm in width, and 20 mm in thickness. Here, the test specimen is removed so that the direction of foaming flow during foaming in the mold (the direction in which the urea resin composition foams and expands, and the direction perpendicular to the bottom surface of the mold; hereafter referred to as the rise direction) is the thickness direction of the test specimen. The surface of the removed test specimen with the rise direction as the normal is defined as the CD surface. The surface perpendicular to the CD surface of the test specimen is defined as the MD surface. The CD surface is observed with an optical microscope (including a digital microscope) to confirm its shape. In this process, 10 bubbles are randomly selected from the CD surface, and the difference between the longest diameter (R1) of each bubble on the CD surface and the diameter perpendicular to that longest diameter (R2) (DR = R1 - R2) is calculated. If the average DR of all selected bubbles exceeds 5 mm, the bubble is judged to be elliptical. Furthermore, a shape between 0mm and 5mm is considered circular. Furthermore, 10 bubbles are randomly selected from both the CD surface and the MD surface, their major axis lengths are measured, and the average length is taken as the average cell diameter in the CD surface and the average cell diameter in the CD surface. The ratio of the average cell diameter in the MD surface to the average cell diameter in the CD surface (average cell diameter in the MD surface / average cell diameter in the CD surface) can be 0.7 to 1.8, and preferably 0.8 to 1.3. When these values ​​fall within this range, a polyurea foam with excellent performance can be obtained.

[0056] 4-4. Closed cell ratio The bubbles contained in the polyurea foam are not particularly limited as long as they do not hinder the effects of the present invention, and may include closed bubbles, open bubbles, or semi-open bubbles. Here, a semi-open bubble structure is a structure in which, unlike closed bubbles, the bubbles have small pores, and the pores between adjacent bubbles are smaller compared to an open bubble structure. The closed-cell ratio of the polyurea foam can be, for example, 75% or more, and preferably 80% or more. When the closed-cell ratio is within this range, a polyurea foam with excellent performance can be obtained. The closed-cell ratio shall be calculated using the following method: A polyurea foam is processed into a test specimen measuring 30 mm in length, 30 mm in width, and 20 mm in thickness. The length of each side is accurately measured to calculate the apparent volume (V) of the test specimen. The mass (W) of the test specimen is measured. The true volume (V1) of the test specimen is measured using a dry automatic densimeter. The value calculated using equations 2 to 4 below shall be considered the closed-cell ratio. Each measurement shall be performed under conditions of 23 ± 5°C and 40-70% relative humidity. (Formula 2) Open cell rate (%): Oc = (V - V1) / V × 100 (Formula 3) Resin content of polyurea foam: S = W / (V × D) × 100 D is the density of the polyurea foam resin itself. (Formula 4) Closed-cell ratio: Cc = 100 - Oc - S

[0057] 4-5.5% weight loss temperature The 5% weight loss temperature of the polyurea foam can be, for example, 120 to 320°C, and preferably 150 to 280°C. When the 5% weight loss temperature is within this range, a polyurea foam having the effects of the present invention can be obtained. The 5% weight loss temperature is measured using a differential thermal / thermogravimetric analyzer (TG / DTA) to observe the weight loss behavior of the polyurea foam in the temperature range of 25 to 700°C and measure the temperature at which the sample weight decreases by 5% by weight. The measurement is performed with a heating rate of 10°C / min and under a dry air flow (flow velocity: 250 mm / min).

[0058] 4-6. Measurement of Ash Content (at 600°C and 700°C) When the polyurea foam is heated to 600°C, the ash content can be, for example, 5 to 60% by weight, with 10% by weight or more being preferred. When the polyurea foam is heated to 700°C, the ash content can be, for example, 3% by weight or more, with 5% by weight or more being preferred. When these values ​​are within these ranges, a polyurea foam having the effects of the present invention can be obtained. The ash content when heated to 600°C and 700°C is determined by observing the weight loss behavior of the polyurea foam in the temperature range of 25 to 600°C or 25 to 700°C using a differential thermal / thermogravimetric analyzer (TG / DTA), measuring the remaining weight of the polyurea foam at 600°C or 700°C, and dividing it by the initial weight of the polyurea foam to obtain the ash content (by weight) at 600°C or 700°C. The measurement is performed at a heating rate of 10°C / min under a dry air flow (flow velocity: 250 mm / min).

[0059] 4-7. Remaining amount held (300°C x 30 minutes, 500°C x 30 minutes) The retained weight of the polyurea foam after heat treatment at 300°C for 30 minutes can be, for example, 30 to 95% by weight, with 55 to 95% by weight being preferred. Similarly, the retained weight of the polyurea foam after heat treatment at 500°C for 30 minutes can be, for example, 15 to 65% by weight, with 25 to 65% by weight being preferred. When these values ​​fall within these ranges, a polyurea foam exhibiting the effects of the present invention can be obtained. The retained weight after heating at 300°C and 500°C for 30 minutes is determined using a differential thermal / thermogravimetric analyzer (TG / DTA). The weight of the polyurea foam after heating to 300°C or 500°C and holding for another 30 minutes is measured, and this weight is divided by the initial weight of the polyurea foam to obtain the retained weight (by weight %). The measurement is performed by heating to a predetermined temperature at a heating rate of 10°C / min, holding the temperature, and using a dry air flow (flow rate: 250 mm / min).

[0060] 4-8. Compressive strength The compressive strength of the polyurea foam can be, for example, 300 to 800 kPa, and preferably 350 to 800 kPa. When the compressive strength is within this range, a polyurea foam having the effects of the present invention can be obtained. The compressive strength is measured by the method described in JIS K7220:2006 "Rigid foamed plastics - Method for determining compressive properties".

[0061] 4-9.Adhesive strength The adhesive strength of the polyurea foam to the wood board can be, for example, 50 to 250 kPa, and preferably 70 to 250 kPa. When the adhesive strength is within this range, a polyurea foam having the effects of the present invention can be obtained. The adhesive strength is measured by the method described in JIS A9526:2015 "Spray-applied rigid polyurethane foam for building insulation".

[0062] 4-10. Thermal conductivity The thermal conductivity of the polyurea foam is not particularly limited as long as it does not hinder the effects of the present invention, but for example it can be 0.015 to 0.040 W / (m·K), and preferably 0.015 to 0.026 W / (m·K). When the thermal conductivity is within this range, a polyurea foam having the effects of the present invention can be obtained. The thermal conductivity is measured by the method described in JIS A1412-1 "Method for measuring the thermal resistance and thermal conductivity of thermal insulating materials - Part 1: Protective heat plate method (GHP method)".

[0063] 4-11. Compression modulus The compressive modulus of the polyurea foam can be, for example, 8 to 30 MPa, and preferably 10 to 30 MPa. When the compressive modulus is within this range, a polyurea foam having the effects of the present invention can be obtained. The compressive modulus is measured by the method described in JIS K7220:2006 "Rigid foamed plastics - Method for determining compressive properties".

[0064] 4-12. Moisture Permeability Coefficient (Water Vapor Transmission Rate) The water vapor permeability coefficient of the polyurea foam can be, for example, 2.5 to 9.5 ng / (m²·s·Pa), with 2.5 to 8.5 ng / (m²·s·Pa) being preferred. When the water vapor permeability coefficient falls within this range, a polyurea foam having the effects of the present invention can be obtained. The water vapor permeability coefficient is measured by the method described in JIS K7225:2018 "Rigid foamed plastics - Method for determining water vapor permeability".

[0065] 4-13. Tensile Strength The tensile strength of the polyurea foam can be, for example, 0.5 to 2.0 MPa, and preferably 0.6 to 2.0 MPa. When the tensile strength is within this range, a polyurea foam having the effects of the present invention can be obtained. The tensile strength is measured by the method described in JIS A9511:2017 "Foamed Plastic Thermal Insulation Materials".

[0066] 4-14. Tensile elongation The tensile elongation of the polyurea foam can be, for example, 45 to 220%, with 55 to 180% being preferred. When the tensile elongation is within this range, a polyurea foam having the effects of the present invention can be obtained. To measure the tensile elongation, a test specimen is prepared in accordance with JIS A9511:2017 "Foamed Plastic Thermal Insulation Materials," and two parallel gauge marks are drawn with a spacing of 50 mm in the tensile direction. This test specimen is tested using a material testing machine at a tensile speed of 500 mm / min, and the spacing between the gauge marks at the time of fracture is measured. The tensile elongation is calculated as (spacing between gauge marks at fracture) / 50 mm (spacing between gauge marks before testing) × 100.

[0067] 4-15. Bending strength The flexural strength of the polyurea foam can be, for example, 0.02 to 0.15 MPa, and preferably 0.025 to 0.15 MPa. When the flexural strength is within this range, a polyurea foam having the effects of the present invention can be obtained. The flexural strength is measured by the method described in JIS K7221-2:2006 "Rigid foamed plastics - Bending test - Part 2: Determination of bending properties".

[0068] 4-16. Charpy Impact Strength The Charpy impact strength of polyurea foam can be, for example, 1.0 to 3.0 kg·cm / cm³, and preferably 1.2 to 3.0 kg·cm / cm³. When the Charpy impact strength falls within this range, a polyurea foam having the effects of the present invention can be obtained. The Charpy impact strength is measured by the method described in JIS K7111-1:2012 "Plastics - Determination of Charpy impact properties - Part 1: Uninstrumented impact test".

[0069] 4-17.Water absorption rate The water absorption rate of the polyurea foam can be, for example, 0.012 to 0.050%, and preferably 0.015 to 0.045%. When the water absorption rate is within this range, a polyurea foam having the effects of the present invention can be obtained. The water absorption rate is calculated by dividing the amount of water absorbed, measured by Method B described in JIS A9511:2017 "Foamed Plastic Thermal Insulation Materials", by the initial weight of the polyurea foam.

[0070] 4-18. Punching Shear Strength The punched shear strength of the polyurea foam can be, for example, 7 to 30 N / cm², and preferably 8 to 25 N / cm². When the punched shear strength falls within this range, a polyurea foam having the effects of the present invention can be obtained. The punched shear strength is measured by the method described in JIS K7214:1985 "Shear Test Method for Plastics by Punching".

[0071] 4-19. Durometer hardness (C hardness) The durometer hardness (C hardness) of the polyurea foam can be, for example, 25 to 65, with 30 to 60 being preferred. When the durometer hardness (C hardness) falls within this range, a polyurea foam having the effects of the present invention can be obtained. The durometer hardness (C hardness) is measured by the method described in JIS K7215:1986 "Test Method for Durometer Hardness of Plastics".

[0072] 4-20. Specific Heat The specific heat of the polyurea foam can be, for example, 0.15 to 0.35 kJ / (kg·°C), and preferably 0.17 to 0.30 kJ / (kg·°C). When the specific heat is within the applicable range, a polyurea foam having the effects of the present invention can be obtained. The specific heat is measured by the input-compensated differential scanning calorimetry method described in JIS K7123:1987 "Method for Measuring the Specific Heat Capacity of Plastics".

[0073] 4-21. Corn calorimeter measurement (total calorific value) The total calorific value of the polyurea foam is measured using a cone calorimeter in accordance with the ISO-5660 test method, under conditions of heating with a radiant heat intensity of 50 kW / m2. The total calorific value after 10 minutes can be 15 MJ / m2 or less, preferably 10 MJ / m2 or less. Furthermore, the total calorific value after 20 minutes can be 15 MJ / m2 or less, preferably 10 MJ / m2 or less, and more preferably 8 MJ / m2 or less. When the total calorific value of the polyurea foam falls within this range, it becomes a polyurea foam with particularly excellent flame retardancy.

[0074] 5. Method for producing polyurea foam The urea resin composition of the present invention is prepared by pre-mixing a polyisocyanate compound (A), a polyamine compound (B), a catalyst, a blowing agent, a foam stabilizer, red phosphorus, other flame retardants, and other additives. Known methods can be used for mixing the urea resin composition. Specifically, raw materials other than polyisocyanate (A) are mixed in a container using a mixer (for example, a stirrer equipped with a propeller-type stirring blade) (for example, stirring at 2000 rpm for 5 minutes using the stirrer) to prepare a composition for producing polyurea foam. Subsequently, the polyisocyanate (A) and the composition for producing polyurea foam are cooled to a predetermined temperature (for example, 10±1℃). After that, the polyisocyanate (A) and the composition for producing polyurea foam are mixed (for example, stirring at 2000 rpm for 5 seconds using the stirrer) to obtain the urea resin composition. Furthermore, the urea resin composition can be foamed and cured to obtain a polyurea foam. When used in a spray application method, the polyurea foam manufacturing composition, which has been pre-mixed with raw materials other than polyisocyanate, and the polyisocyanate compound (A) are supplied to a spray gun using a pump or the like (the nozzle of the spray gun is opened at this time). The polyurea foam manufacturing composition and the polyisocyanate compound (A) are mixed in the chamber inside the spray gun, and the mixture is sprayed onto the structure to obtain polyurea foam. The polyurea foam manufacturing composition, which has been pre-mixed with raw materials other than polyisocyanate compound (A), and the polyisocyanate compound (A) can be handled as a two-component system liquid. Flame retardants, foam stabilizers, blowing agents, dispersants, and other additives that do not react with the polyisocyanate compound (A) can also be mixed with the polyisocyanate compound (A) and handled as a system liquid.

[0075] The content of polyamine compound (B) in the urea resin composition is 2.0% by mass or more, preferably 5.0% by mass or more, and more preferably 8.0% by mass or more, when the total amount of the urea resin composition is considered to be 100% by mass. The upper limit of the content of polyamine compound (B) can be, for example, 40.0% by mass or less, preferably 30.0% by mass or less, and more preferably 20.0% by mass or less. From another viewpoint, the content of polyamine compound (B) in the urea resin composition can be blended so that the isocyanate index of the urea resin composition is 200 to 600, and more preferably 200 to 500. Here, the isocyanate index is the value obtained by multiplying the ratio of the number of moles of active hydrogen in the resin composition, which is the total amount of raw materials, to the number of moles of isocyanate groups in polyisocyanate compound (A) by 100 (moles of NCO / moles of active hydrogen × 100). When the isocyanate index of the resin composition falls within a certain range, a sufficient isocyanurate structure is formed, and the isocyanuration rate can be adjusted to an appropriate level. As a result, the flame retardancy of the polyurea foam can be improved. Furthermore, when the polyurea foam manufacturing composition, which is a mixture of raw materials other than polyisocyanate compound (A), and polyisocyanate compound (A) are handled as a two-component system liquid, the content of polyamine compound (B) in the polyurea foam manufacturing composition is 2.0% by mass or more, preferably 5.0% by mass or more, and more preferably 8.0% by mass or more, when the sum of the polyurea foam manufacturing composition and polyisocyanate compound (A) is taken as 100% by mass. The upper limit of the content of polyamine compound (B) can be, for example, 40.0% by mass or less, preferably 30.0% by mass or less, and more preferably 20.0% by mass or less. From another viewpoint, the content of polyamine compound (B) in the polyurea foam manufacturing composition can be formulated so that the isocyanate index when the polyurea foam manufacturing composition and polyisocyanate compound (A) are mixed is 200 to 600, and more preferably 200 to 500.

[0076] The content of polyisocyanate compound (A) in the urea resin composition can be 100 to 1000 parts by mass, assuming the total content of polyamine compound (B) in the urea resin composition is 100 parts by mass. Furthermore, when the polyurea foam manufacturing composition and the polyisocyanate compound (A) are handled as a two-component system solution, the total content of the polyamine compound (B) in the polyurea foam manufacturing composition can be 100 to 1000 parts by mass, assuming a total content of 100 parts by mass.

[0077] The content of the foam stabilizer in the urea resin composition or the composition for manufacturing polyurea foam can be 0.1 to 20 parts by mass, when the total content of polyamine compound (B) in the urea resin composition or the composition for manufacturing polyurea foam is 100 parts by mass. Furthermore, the content of the foam stabilizer contained in the polyurea foam can be 0.1 to 20% by mass, with 0.5 to 15% by mass being preferred, when the total mass of the polyurea foam is 100% by mass.

[0078] The amount of flame retardant in the urea resin composition or the composition for manufacturing polyurea foam can be 10 to 200 parts by mass, preferably 30 to 150 parts by mass, and more preferably 50 to 100 parts by mass, when the total amount of polyamine compound (B) in the urea resin composition or the composition for manufacturing polyurea foam is 100 parts by mass. When the amount of flame retardant is within this range, a polyurea foam with excellent flame retardancy can be obtained. Furthermore, the amount of flame retardant contained in the polyurea foam can be 1 to 60% by mass, preferably 2 to 45% by mass, when the total mass of the polyurea foam is 100% by mass.

[0079] The content of red phosphorus in the urea resin composition or the composition for manufacturing polyurea foam can be 100 parts by mass or less, preferably 5 to 40 parts by mass, and more preferably 25 to 40 parts by mass, when the total content of polyamine compound (B) in the urea resin composition or the composition for manufacturing polyurea foam is 100 parts by mass. Furthermore, the content of red phosphorus contained in the polyurea foam can be 0 to 30% by mass, preferably 1 to 30% by mass, and more preferably 2 to 25% by mass, when the total mass of the polyurea foam is 100% by mass. When the red phosphorus content is within this range, a polyurea foam with superior flame retardancy can be obtained, and deterioration over time in a humid and hot environment can be suppressed. In particular, the ash content after thermal decomposition of the foam increases, and in the flame contact evaluation described later, the formation of a non-combustible carbonized layer in the initial stages of flame contact can prevent combustion from progressing to the deeper parts of the foam. Furthermore, the total content of flame retardants selected from phosphate esters, phosphate-containing flame retardants, bromine-containing flame retardants, boron-containing flame retardants, antimony-containing flame retardants, and metal hydroxides can be 10 to 200 parts by mass, when the total content of polyamine compound (B) in the urea resin composition is 100 parts by mass. Also, the ratio (Fp / Ft) of the red phosphorus content (Fp) in the urea resin composition to the total content (Ft) of flame retardants selected from phosphate esters, phosphate-containing flame retardants, bromine-containing flame retardants, boron-containing flame retardants, antimony-containing flame retardants, and metal hydroxides is not particularly limited, but can be, for example, 0.0 to 1.0, preferably 0.0 to 0.8, more preferably 0.09 to 0.73, and even more preferably 0.45 to 0.73. When these flame retardants are blended within a certain range, a polyurea foam can be obtained that possesses excellent flame retardancy and shape retention during combustion, and that can suppress deterioration over time in a humid and hot environment.

[0080] The content of the trimerizing catalyst in the urea resin composition or the composition for producing polyurea foam can be 0.1 to 30 parts by mass, preferably 1 to 20 parts by mass, more preferably 5 to 20 parts by mass, and even more preferably 10 to 20 parts by mass, when the total content of polyamine compound (B) in the resin composition or the composition for producing polyurea foam is 100 parts by mass. When the content of the trimerizing catalyst is within this range, isocyanuration is sufficient, and a polyurea foam can be obtained that has excellent flame retardancy and shape retention during combustion, and that can suppress deterioration over time in a humid and hot environment. Furthermore, the content of the trimerizing catalyst contained in the polyurea foam can be 0.01 to 20% by mass, preferably 0.05 to 15% by mass, when the total mass of the polyurea foam is 100% by mass.

[0081] The amount of the blowing agent in the urea resin composition or the composition for producing polyurea foam can be 1 to 60 parts by mass, preferably 5 to 50 parts by mass, when the total amount of polyamine compound (B) in the resin composition or the composition for producing polyurea foam is 100 parts by mass. When the amount of the blowing agent is within this range, a polyurea foam can be obtained that has excellent flame retardancy and shape retention during combustion, and that can suppress deterioration over time in a humid and hot environment. Furthermore, the amount of the blowing agent contained in the polyurea foam can be 1 to 40% by mass, preferably 3 to 30% by mass, when the total mass of the polyurea foam is 100% by mass.

[0082] When a catalyst other than a trimerizing catalyst (such as a resinification catalyst or foaming catalyst) is incorporated, the content of the catalyst other than the trimerizing catalyst may be 1 to 10 parts by mass, based on 100 parts by mass of the total content of polyamine compound (B) in the urea resin composition or the composition for producing polyurea foam. Compounds that have the effects of both a resinification catalyst and a foaming catalyst shall be incorporated as a resinification catalyst. Furthermore, the content of the catalyst other than the trimerizing catalyst in the polyurea foam may be 0 to 20% by mass, with 0.5 to 15% by mass being preferred, based on 100% by mass of the total mass of the polyurea foam.

[0083] 6. Uses of polyurea foam The polyurea foam of the present invention is used in building applications (walls, ceilings, roofs, floors, etc.), joinery (windows, shoji screens, doors, fusuma sliding doors, transoms, etc.), ships and storage tanks for transporting petroleum and gas, vehicles (engines, batteries, ceilings, floors, door panels, etc.), aircraft, transport planes, insulated bags for transporting pharmaceuticals, freezers and refrigerators, plant facilities, and electrical appliances such as refrigerators, as well as in retaining walls, as an insulating material, heat insulating material, and cold resistance mitigating material. It is also used as an underground filling reinforcement material for ground subsidence prevention work and road construction, as an injection repair material for civil engineering applications such as tunnels, bridges, and floating piers, as a structural filling material for unnecessary basements, as an energy absorbent material, waterproofing material, water-stopping material, and buoyancy material. Furthermore, in wooden and reinforced concrete buildings, it can be used as a polyurea foam for spray application because it is easy to install as insulation. [Examples]

[0084] <<Preparation of Resin Composition>> <Raw materials> (Polyamine compound (B)) • EtaCure 420 (manufactured by Albemarle, amine value: 562 mg KOH / G) • Elastomer 250P (manufactured by Kumiai Chemical Industry Co., Ltd., amine value: 254 mg KOH / g) • ANCAMINE2049 (manufactured by Evonik, amine value: 484 mg KOH / g) • Elastomer 1000P (manufactured by Kumiai Chemical Industry Co., Ltd., amine value: 93 mg KOH / g) (Polyol compounds) • Maximol RLK-505 (manufactured by Kawasaki Chemical Industries, Ltd., hydroxyl value: 250 mg KOH / g) (Flame retardant) Tris(2-chloropropyl) phosphate (TMCPP, chlorine-containing phosphate ester) • Resorcinol bis(diphenyl) phosphate (PFR, phosphate ester) ·Red phosphorus • Ammonium polyphosphate (phosphate-containing flame retardant) • Aluminum hypophosphate (a flame retardant containing phosphinate) • Sodium hypophosphate (a flame retardant containing phosphinate) Decabromodiphenyl oxide (bromine-containing flame retardant) • Zinc borate (boron-containing flame retardant) • Antimony trioxide (antimony-containing flame retardant) • Aluminum hydroxide (metal hydroxide flame retardant) • Expanded graphite DOWSIL TM-4 7081 (manufactured by Dow Toray, acrylic-modified silicone resin, silicone-based flame retardant) (Foam stabilizer) • SF2937F (silicone-based surfactant manufactured by Toray Dow Corning Co., Ltd.) • Disparon SEI-1501 (manufactured by Kusumoto Chemical Co., Ltd., acrylic polymer, organic surfactant) (catalyst) • Bismuth 2-ethylhexanoate (bismuth-based catalyst) • Dibutyltin dimercaptide (tin-based catalyst) • N,N-dimethylaminoethanol (foaming catalyst) Titanium-tetra(2-ethylhexoside) (titanium-based catalyst) • TEDA (triethylenediamine, amine-based catalyst) • BDMAEE (Bis(dimethylaminoethyl) ether) • 1,2-dimethylimidazole • PMDETA (Pentamethyldiethyltriamine) • TOYOCAT-TRX (manufactured by Tosoh Corporation, trimerization catalyst) • U-CAT 18X ​​(manufactured by Sunapro, quaternary ammonium salt, trimerization catalyst) • Diazabicycloundecene (trimerization catalyst) • 1,3,5-Tris(dimethylaminopropyl)hexahydro-s-triazine (trimerization catalyst) • Potassium octylate (trimerization catalyst) (Foaming agent) • Opteon 1100 (manufactured by Mitsui Fluorochemours, HFO-1336mzZ, boiling point 33℃) • Opteon 1150 (manufactured by Mitsui Fluorochemours, boiling point 7°C) • Cyclopentane (boiling point 49°C) Water (boiling point 100℃) (Polyisocyanate compound (A)) • Millionate MR-200 (manufactured by Tosoh Corporation, NCO%: 30.9%, crude MDI) • FoamLite MI (BASF INOAC Polyurethane, NCO%: 33.3%, Monomeric MDI) • Cosmonate™-50 (manufactured by Mitsui Chemicals SKC Polyurethane Co., Ltd., NCO%: 39.5%, TDI / MDI mixture) • Proprietary urethane prepolymer (NCO%: 27.0%, isocyanate-terminated urethane prepolymer) Our proprietary urethane prepolymer was prepared using the following method. A predetermined amount of crude MDI (Tosoh Corporation, Millionate MR-200) was charged into a 5L polyethylene container equipped with a mechanical stirrer, anchor-type stirring blades, and a nitrogen inlet tube, and the liquid temperature of the isocyanate (crude MDI) was set to 25°C. Polypropylene glycol (Mitsui Chemicals SKC Polyurethane Co., Ltd., Actcol D2000, hydroxyl value: 55.1) was then added in predetermined amounts in stages, ensuring that the liquid temperature did not exceed 80°C. After the addition of polypropylene glycol was completely finished, the mixture was stirred at a stirring speed of 60 rpm for 2 hours to react the isocyanate and polyol, thereby obtaining an isocyanate-terminated prepolymer. The NCO group content of the obtained prepolymer was measured in accordance with JIS K1603-1 (Method A), and it was confirmed that the predetermined NCO group content was met.

[0085] <Preparation of foam> (Preparation of mixed solutions and foams used for evaluations other than adhesion evaluation) In 500 mL disposable polypropylene cups, the polyamine compound, polyol compound, trimerizing catalyst, flame retardant, foaming agent, foam stabilizer, and other additives were weighed out in the amounts specified for each example and comparative example in Tables 1 to 7, and these were used to create the mixtures for each example and comparative example. Each mixture was stirred and mixed at 2000 rpm for 5 minutes using a stirrer equipped with a propeller-type impeller to obtain the polyurea foam production compositions and polyol mixtures for each example and comparative example. The obtained polyamine mixtures and polyisocyanates, weighed out in the amounts specified in Tables 1 to 7, were placed in a cooling furnace at 10°C and cooled individually to 10 ± 1°C. The polyamine mixtures and polyol mixtures of each example and comparative example, along with the polyisocyanates, were stirred and mixed at 2000 rpm for 5 seconds using a stirrer equipped with a propeller-type impeller to foam and harden, obtaining the foams for each example and comparative example. For adhesion evaluation, the polyamine and polyol mixtures of each example and comparative example, along with the polyisocyanate weighed out in the amounts listed in Tables 1-7, were individually cooled to 10±1°C. These mixtures were then mixed using a hand sprayer for rigid polyurethane foam application (described later) and sprayed onto the target object to form a foam for adhesion evaluation.

[0086] <<Rating>> The following evaluations were performed on the foams of each example and comparative example. Each foam was cured for 24 hours after foaming in an environment of 23±5°C and 50±20% relative humidity. Evaluations marked "after moist heat treatment" indicate that the foams of each example and comparative example, after curing, were subjected to moist heat treatment for one month in an environment of 80°C and 85% RH, and these were used as the measurement samples after moist heat treatment for each example and comparative example. The measurement method was the same as the measurement method for samples without moist heat treatment. <Measurement of isocyanurate conversion rate> The infrared absorption spectra of the foams from each example and comparative example were measured using a Fourier transform infrared spectrometer (FT-IR, model FT / IR-4200, manufactured by JASCO Corporation). The measurements were performed using the ATR method with a diamond prism, with 50 integration cycles. The isocyanurate conversion rate in the foam was calculated using Equation 1. Measurements were taken at three points—top, center, and bottom—relative to the rise direction of the foam, and the average value was used. The measurement results are shown in Tables 1 to 7. (Observation peak) P1: Peak area derived from the isocyanurate structure in the absorption spectrum of the foam obtained by infrared spectroscopy (observation range: 1380~1430 cm⁻¹) P2: Peak area originating from the C=O structure of the urea structure in the absorption spectrum of polyurea foam obtained by infrared spectroscopy (observation range: 1550~1640 cm⁻¹) P3: Peak area derived from the C=O structure of the urethane and isocyanurate structures in the absorption spectrum of the foam obtained by infrared spectroscopy (Observation range: 1680~1730 cm⁻¹) P4: Peak area derived from NH contained in the polyurea and urea structures in the absorption spectrum of the foam obtained by infrared spectroscopy (Observation range: 1470~1550 cm⁻¹) (Formula 1) Isocyanurate conversion rate = P1 / (P1+P2+P3+P4)×100

[0087] <density> The apparent density of the foams in each example and comparative example was measured using the method described in JIS K7222:2005 "Foamed plastics and rubber - Method for determining apparent density". The results are shown in Tables 8 to 14.

[0088] <Average cell (bubble) diameter and cell shape> The polyurea foam manufacturing compositions and polyol mixtures of each example and comparative example were mixed with polyisocyanate using the method described above, and foamed and cured in a mold to obtain the foams of each example and comparative example. Test pieces measuring 50 mm in length, 50 mm in width, and 20 mm in thickness were cut from each obtained foam, and the bubbles in the CD surface and MD surface were observed using a digital microscope (Keyence VHX-800) to confirm their shape. Ten bubbles were randomly selected from the CD surface, and the difference between the longest diameter (R1) in the CD surface of each bubble and the diameter in the direction perpendicular to that longest diameter (R2) (DR = R1 - R2) was calculated. If the average DR of all selected bubbles exceeded 5 mm, it was judged to be elliptical. If it was between 0 mm and 5 mm, it was judged to be circular. Furthermore, 10 bubbles were randomly selected from both the CD surface and the MD surface, their major axis lengths were measured, and the average lengths were used as the average cell diameter on the CD surface and the average cell diameter on the MD surface. The ratio of the average cell diameter on the MD surface to the average cell diameter on the CD surface (average cell diameter on the MD surface / average cell diameter on the CD surface) was also calculated. The results are shown in Tables 8-14.

[0089] <Closed cell ratio> The closed-cell ratio of the foams in each example and comparative example was measured by the following method. The foams in each example and comparative example were processed into test specimens measuring 30 mm in length, 30 mm in width, and 20 mm in thickness. The length of each side was accurately measured, and the apparent volume (V) of the test specimen was calculated. The mass (W) of the test specimen was measured. The true volume (V1) of the test specimen was measured using a dry automatic densimeter (Shimadzu Corporation, Micromeritex Accupic II 1340). Using these values, the closed-cell ratio was calculated using the following equations 2 to 4. Each measurement was performed under conditions of 23 ± 5°C and 40-70% relative humidity. (Formula 2) Open cell rate (%): Oc = (V - V1) / V × 100 (Formula 3) Resin content of polyurea foam: S = W / (V × D) × 100 D is the density of the polyurea foam resin itself. (Formula 4) Closed-cell ratio: Cc = 100 - Oc - S The results are shown in Tables 8-14.

[0090] <5% weight loss temperature> Approximately 10 mg of foam from each example and comparative example was taken, and a thermogravimetric analyzer (TGA) was used to measure the temperature at which the sample weight decreased by 5% by weight when heated from 25 to 600°C. The measurement conditions were a heating rate of 10°C / min and an airflow of 200 ml / min. The results are shown in Tables 8 to 14. Measurements were also performed on the foam after moist heat treatment, and the results are shown in Tables 15 to 21.

[0091] <Measurement of ash content (600°C, 700°C)> 3-5 mg of foam was taken from the center of each example and comparative example. The sample was placed in an aluminum pan (for measurement at 600°C) or a platinum pan (for measurement at 700°C), and the weight loss behavior of the sample was observed in the temperature range of 25-600°C or 25-700°C using a TG / DTA analyzer (SII Corporation, model TG / DTA7200). The ash content (%) of each foam was determined from the remaining weight of the sample at 600°C or 700°C. The measurement was performed at a heating rate of 10°C / min under a dry air flow (flow velocity: 250 mm / min). The results are shown in Tables 8-14. Measurements were also performed on the foam after moist heat treatment, and the results are shown in Tables 15-21.

[0092] <Remaining amount held (300°C x 30 minutes, 500°C x 30 minutes)> The foams of each example and comparative example were heated to 300°C or 500°C using a differential thermal / thermogravimetric analyzer (TG / DTA), and then held for 30 minutes. The remaining weight of each foam was measured and divided by the initial weight of the polyurea foam to obtain the retained weight (weight %). The measurement was performed by heating at a rate of 10°C / min to the specified temperature and holding it thereafter. The evaluation was also performed under a dry air flow (flow rate: 250 mm / min). The results are shown in Tables 8 to 14. Measurements were also performed on the foams after moist heat treatment, and the results are shown in Tables 15 to 21.

[0093] <Compressive strength> The compressive strength of the foams in each example and comparative example was measured using the method described in JIS K7220:2006 "Rigid foamed plastics - Method for determining compressive properties". The results are shown in Tables 8 to 14. Measurements were also performed on the foams after moist heat treatment, and the results are shown in Tables 15 to 21.

[0094] <Adhesive strength> The adhesive strength of the foams in each example and comparative example was measured using the method described in JIS A9526:2015 "Spray-applied rigid polyurethane foam for building insulation". The results are shown in Tables 8 to 14. Measurements were also performed on the foams after moist heat treatment, and the results are shown in Tables 15 to 21.

[0095] <Measurement of thermal conductivity> The thermal conductivity of the foams in each example and comparative example was measured according to JIS A1412-1:2016 "Method for measuring thermal resistance and thermal conductivity of thermal insulating materials - Part 1: Protective hot plate method (GHP method)". The results are shown in Tables 8 to 14. Measurements were also performed on the foams after moist heat treatment, and the results are shown in Tables 15 to 21.

[0096] <Compression modulus> The compressive modulus of the foams in each example and comparative example was measured using the method described in JIS K7220:2006 "Rigid foamed plastics - Method for determining compressive properties". The results are shown in Tables 8 to 14. Measurements were also performed on the foams after moist heat treatment, and the results are shown in Tables 15 to 21.

[0097] <Moisture vapor permeability coefficient (water vapor transmission rate)> The water vapor permeability coefficient of the foams in each example and comparative example was measured using the method described in JIS K7225:2018 "Rigid foamed plastics - Method for determining water vapor permeability". The results are shown in Tables 8 to 14.

[0098] <Tensile strength> The tensile strength of the foams in each example and comparative example was measured using the method described in JIS A9511:2017 "Foamed Plastic Thermal Insulation Materials". The results are shown in Tables 8 to 14.

[0099] <Tensile stretch> The tensile elongation of the foams in each example and comparative example was measured by the following method. Test specimens were prepared in accordance with JIS A9511:2017 "Foamed Plastic Thermal Insulation Materials," and two parallel gauge marks were drawn with a tensile distance of 50 mm. These test specimens were tested using a material testing machine at a tensile speed of 500 mm / min, and the distance between the gauge marks at the time of fracture was measured. The tensile elongation was calculated as (distance between gauge marks at fracture) / 50 mm (distance between gauge marks before testing) × 100, and the results are shown in Tables 8 to 14.

[0100] <Bending strength> The flexural strength of the foams in each example and comparative example was measured using the method described in JIS K7221-2:2006 "Rigid foamed plastics - Bending test - Part 2: Method for determining bending properties". The results are shown in Tables 8 to 14.

[0101] <Charpy impact strength> The Charpy impact strength of the foams in each example and comparative example was measured using the method described in JIS K7111-1:2012 "Plastics - Determination of Charpy impact properties - Part 1: Uninstrumented impact test". The results are shown in Tables 8 to 14.

[0102] <Water absorption rate> The water absorption rate of the foams in each example and comparative example was calculated by dividing the amount of water absorbed, measured using Method B described in JIS A9511:2017 "Foamed Plastic Thermal Insulation Materials," by the initial weight of each foam. The results are shown in Tables 8 to 14.

[0103] <Punching shear strength> The punched shear strength of the foams in each example and comparative example was measured using the method described in JIS K7214:1985 "Shear Test Method for Plastics by Punching". The results are shown in Tables 8 to 14.

[0104] <Durometer hardness (C hardness)> The durometer hardness (C hardness) of the foams of each example and comparative example was measured using the method described in JIS K7215:1986 "Test Method for Durometer Hardness of Plastics". The results are shown in Tables 8 to 14.

[0105] <Specific heat> The specific heat of the foams in each example and comparative example was measured using the input-compensated differential scanning calorimetry method described in JIS K7123:1987 "Method for Measuring the Specific Heat Capacity of Plastics". The results are shown in Tables 8 to 14.

[0106] <Dimensional changes before and after moist heat treatment> The foams of each example and comparative example were subjected to moist heat treatment for one month under conditions of 80°C and 85% RH, and the rate of change in dimensions before and after moist heat treatment was measured. The measurement samples of the foam were 100 mm in length, 100 mm in width, and 20 mm in thickness, and the dimensions of the measurement samples were measured using calipers. The results are shown in 15-21.

[0107] <Volume change rate (600℃)> Samples measuring 5 cm in length, 5 cm in width, and 5 cm in thickness were cut from the center of the foam of each example and comparative example, and placed in an electric furnace heated to 600°C for 5 minutes. The volume change rate was then measured. The volume before heating was set to 100%, the volume after heating was measured, and the difference between the volume after heating and the volume before heating was divided by the volume before heating and multiplied by 100 to determine the volume change rate. A positive value indicates expansion, and a negative value indicates contraction. The results are shown in Tables 15 to 21.

[0108] <Adhesiveness> Each example and comparative example's polyamine mixture and polyol mixture, along with polyisocyanate weighed out in the amounts listed in Tables 1-7, were individually cooled to 10±1°C. These mixtures were then sprayed onto the surface of a wooden board at a surface temperature of 15°C using a rigid polyurethane foam sprayer (ADY Co., Ltd.), and foamed on the wooden board surface. After curing for 24 hours, the mixture was evaluated as follows: 1 point for no peeling or lifting at the adhesive interface between the wooden board and the foam, and 0 points for peeling or lifting. The results are shown in Tables 15-21.

[0109] <Flame test> From the foams of each example and comparative example, 24 hours after foaming, samples were cut out to form rectangular parallelepipeds measuring 10 cm in length, 10 cm in width, and 5 cm in thickness. Each obtained sample was placed on a wire mesh measuring 10 cm in length, 10 cm in width, and 1 mm in thickness, and the surface of the sample was indirectly flammed with a gas burner for 3 minutes. Methane gas with a purity of 99.5% or higher was used as the combustion gas, supplied at 0.2 MPa to produce a pale blue flame. The flame height was set to 5 cm, and the distance between the flame and the sample surface was set to 1 cm. After flame contact, the sample was cut in half, and the presence or absence of cracks in the cross-section was visually observed. The maximum distance of the blackened, carbonized portion in the cross-section (length from the side surface of the cross-section to the carbonized portion) was measured as the depth of the carbonized layer. The results are shown in Tables 1-3. The evaluation was determined according to the following evaluation criteria, and the results are shown in Tables 15-21. In the tables, "unmeasurable" indicates that measurement was not possible because the flame penetrated the sample during flame contact.

[0110] <Total heat output (50kW x 10 minutes, 20 minutes) measurement> Samples measuring 10 cm in length, 10 cm in width, and 5 cm in thickness were cut from the center of the foam of each example and comparative example. A cone calorimeter total calorific value test was performed on the foam in accordance with ISO-5660 (Building Standards Act Article 2), and the total calorific value and maximum calorific value of the sample were measured. The measurements were taken with a radiant heat load of 50 kW / m2 and measurement times of 10 minutes and 20 minutes. The results are shown in Tables 15 to 21. In the table, "measurement impossible" indicates that the expanded sample came into contact with the tip of the cone calorimeter's spark plug during the test, preventing spark generation and thus preventing a normal measurement.

[0111] For each example and comparative example foam, a UL94 flame retardancy test was performed according to standard 5VA, and the burning distance, burning time, presence or absence of drip / cotton ignition, presence or absence of flame penetration, and size of the penetration holes were measured.

[0112] <Evaluation using actual equipment (spray)> Polyamine compounds, flame retardants, catalysts, foam stabilizers, and blowing agents were weighed into a pail container according to the formulations of Examples 1, 18, and 92 described in Tables 1, 2, and 7. The mixture was stirred for 5 minutes at room temperature using a power mixer (Ryobi, model PM-1511) to prepare an amine mixture (system liquid). A spray gun (Graco, Fusion Gun) was attached to the main unit (Graco, HR-V), and the temperature control of the pump and hose was set to 40°C. The pump was operated, and the difference in liquid pressure between the amine mixture (system liquid) and the separately thoroughly stirred polyisocyanate was adjusted to within 2.0 MPa. The nozzle of the spray gun was opened, and the amine mixture (system liquid) and isocyanate were mixed in the chamber inside the gun. The mixture was then sprayed onto the structure to produce the foams of Examples 1, 18, and 92, and evaluated in the same manner as the method without using a spray described above. Foams with the same formulation as those in Examples 1, 18, and 92 yielded the same results as those in Examples 1, 18, and 92, respectively.

[0113] [Table 1]

[0114] Table 2

[0115] Table 3

[0116] Table 4

[0117] Table 5

[0118] Table 6

[0119] Table 7

[0120] Table 8

[0121] Table 9

[0122] Table 10

[0123] Table 11

[0124] Table 12

[0125] Table 13

[0126] Table 14

[0127] Table 15

[0128] Table 16

[0129] Table 17

[0130] Table 18

[0131] Table 19

[0132] Table 20

[0133] Table 21

Claims

1. A urea resin composition comprising a polyisocyanate compound (A), a polyamine compound (B), a trimerizing catalyst, a foaming agent, a foam stabilizer, and a flame retardant, characterized in that the flame retardant comprises red phosphorus.

2. A urea resin composition comprising a polyisocyanate compound (A), a polyamine compound (B), a trimerizing catalyst, a foaming agent, a foam stabilizer, and a flame retardant, wherein the trimerizing catalyst comprises a quaternary ammonium salt.

3. The urea resin composition according to claim 1 or claim 2, comprising a hydrofluoroolefin as the foaming agent.

4. The urea resin composition according to any one of claims 1 to 3, wherein the content of the trimerizing catalyst is 5 to 20 parts by mass when the content of the polyamine compound (B) in the urea resin composition is 100 parts by mass.

5. A polyurea foam obtained by foaming and curing a urea resin composition according to any one of claims 1 to 4.

6. A composition for producing polyurea foam comprising a polyamine compound (B), a trimerizing catalyst, a flame retardant, a blowing agent, and a foam stabilizer, characterized in that the flame retardant comprises red phosphorus.

7. A composition for producing polyurea foam, comprising a polyamine compound (B), a trimerizing catalyst, a blowing agent, and a foam stabilizer, wherein the trimerizing catalyst comprises a quaternary ammonium salt.

8. The composition for producing polyurea foam according to claim 6 or claim 7, comprising a hydrofluoroolefin as the foaming agent.

9. The polyurea foam production composition according to any one of claims 6 to 8, wherein the content of the trimerizing catalyst is 5 to 20 parts by mass when the content of the polyamine compound (B) in the polyurea foam production composition is 100 parts by mass.

10. It comprises a polyisocyanate compound (A), a polyamine compound (B), a trimerizing catalyst, a blowing agent, a foam stabilizer, and a flame retardant. A urea resin composition in which the polyamine compound (B) is one or more selected from the group consisting of 4,4'-diamino-3,3'-dichlorodiphenylmethane, trimethylene-bis(4-aminobenzoate), 4,4'-diamino-3,3'-diethyl-5,5'-dimethyldiphenylmethane, polytetramethylene oxide-di-p-aminobenzoate, 2,2',6,6'-tetraethyl-4,4'-methylenedianiline, 4,4'-methylenebis(2-isopropyl-6-methylaniline), 4,4'-methylenebis(2,6-diisopropylaniline), 4,4'-methylenebis(3-chloro-2,6-diethylaniline), 3,5-diethyltoluene-2,4-diamine, and dimethylthiotoluenediamine, A polyurea foam obtained by foaming and hardening.

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