JP5267084B2 - Urethane resin composition - Google Patents

Description

  The present invention relates to a urethane resin composition. More specifically, the present invention relates to a urethane resin composition that can be suitably used for a sealing material or the like.

Polyurethane resins with urethane prepolymer as a curing component are one-component moisture-curing type that is cured by moisture in the air and two-component curing type that is cured by mixing with a curing agent component that reacts with isocyanate such as polyol. It is classified and used.
Among these, the use of a one-component moisture-curing polyurethane resin composition has been expanded for the reason that it is not necessary to prepare and mix the resin composition in the field construction and is easy to handle.

However, the one-part moisture-curing polyurethane resin composition liberates carbon dioxide during the cross-linking reaction with moisture in the air or adsorbed to the compounding agent, and foaming occurs, resulting in voids in the cured urethane resin composition. There is a problem that the strength is lowered.
On the other hand, by using oxazolidine as a latent curing agent, it is known that foaming due to liberation of carbon dioxide is prevented, and storage stability is improved compared to the case of using other curing agents (for example, patents). Reference 1 to 3 etc.).

JP 11-35819 A JP 2002-37847 A JP 2004-107370 A

  However, in the one-part moisture curable polyurethane resin composition described in Patent Documents 1 to 3, the present inventor has an active hydrogen group (hydroxyl group, amino group) generated by cleavage of an isocyanate group and an oxazolidine ring by hydrolysis. However, depending on the oxazolidine compound used, the modulus after curing increases, the setability after compression heating increases, and repeated durability (hereinafter simply referred to as “durability”). )), It is clear that improvement is necessary.

  Therefore, an object of the present invention is to provide a urethane resin composition that maintains good storage stability and foam resistance and is excellent in durability.

As a result of intensive studies to solve the above-mentioned problems, the present inventors have found that a urethane resin composition containing a urethane prepolymer having an isocyanate group at the molecular terminal and a polysulfide polymer having an oxazolidine terminal is provided with storage stability and resistance. The present invention was completed by finding that the foamability was maintained well and excellent in durability.
That is, this invention provides the urethane resin composition as described in following (1)-(3).

(1) a urethane prepolymer having an isocyanate group at the molecular end ;
A urethane resin composition comprising: a polysulfide polymer having a terminal oxazolidine.

  (2) The urethane resin composition according to (1), wherein the content of the polysulfide polymer is 0.5 to 100 parts by mass with respect to 100 parts by mass of the urethane prepolymer.

  (3) The urethane resin composition according to (1) or (2) above, wherein an equivalent ratio of the isocyanate group of the urethane prepolymer to the oxazolidinyl group of the polysulfide polymer (isocyanate group / oxazolidinyl group) is 1 to 50.

As described below, according to the present invention, it is possible to provide a urethane resin composition that maintains good storage stability and foam resistance and is excellent in durability.
The urethane resin composition of the present invention is useful because it can be suitably used for various sealing materials, joint materials, adhesives, paints, waterproofing materials and flooring materials.

The present invention is described in detail below.
The urethane resin composition of the present invention (hereinafter also referred to as “resin composition of the present invention”) has a urethane prepolymer having an isocyanate group at the molecular terminal (hereinafter simply referred to as “urethane prepolymer”) and a terminal . A urethane resin composition containing an oxazolidinized polysulfide polymer.
Next, the urethane prepolymer and polysulfide polymer used in the resin composition of the present invention will be described in detail.

<Urethane prepolymer>
The urethane prepolymer used in the resin composition of the present invention is obtained by reacting a port polyol compound with a polyisocyanate compound, as the isocyanate group relative to the hydroxyl group (OH group) (NCO group) becomes excessive the reaction product Ru used.
Moreover, it is preferable that the said urethane prepolymer contains 0.5-5 mass% NCO group in a molecular terminal.

(Polyisocyanate compound)
The polyisocyanate compound used in the production of the urethane prepolymer is not particularly limited as long as it has two or more isocyanate groups in the molecule.
Specific examples of the polyisocyanate compound include TDI (for example, 2,4-tolylene diisocyanate (2,4-TDI), 2,6-tolylene diisocyanate (2,6-TDI)), MDI ( For example, 4,4'-diphenylmethane diisocyanate (4,4'-MDI), 2,4'-diphenylmethane diisocyanate (2,4'-MDI)), 1,4-phenylene diisocyanate, polymethylene polyphenylene polyisocyanate, xylylene diene Aromatic polyisocyanates such as isocyanate (XDI), tetramethylxylylene diisocyanate (TMXDI), tolidine diisocyanate (TODI), 1,5-naphthalene diisocyanate (NDI), triphenylmethane triisocyanate; Aliphatic polyisocyanates such as socyanate (HDI), trimethylhexamethylene diisocyanate (TMHDI), lysine diisocyanate, norbornane diisocyanate (NBDI); transcyclohexane-1,4-diisocyanate, isophorone diisocyanate (IPDI), bis (isocyanatomethyl) cyclohexane (H ₆ XDI), cycloaliphatic polyisocyanates such as dicyclohexylmethane diisocyanate (H ₁₂ MDI); carbodiimide-modified polyisocyanates; isocyanurate-modified polyisocyanates; and the like.

  Such polyisocyanate compounds can be used alone or in combination of two or more.

(Polyol compound)
The polyol compound used in the production of the urethane prepolymer is not particularly limited as long as it has two or more hydroxyl groups.
Examples of the polyol compound include polyether polyols, polyester polyols, other polyols, and mixed polyols thereof.

  Examples of the polyether polyol include ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, glycerin, 1,1,1-trimethylolpropane, 1,2,5-hexanetriol, 1,3-butanediol, 1, Polyols obtained by adding at least one selected from the group consisting of ethylene oxide, propylene oxide, butylene oxide and polyoxytetramethylene oxide to at least one selected from the group consisting of 4-butanediol and pentaerythritol, etc. Is mentioned. Specifically, polypropylene ether diol and polypropylene ether triol are preferably exemplified.

  Specifically, the polyester polyol is selected from the group consisting of, for example, ethylene glycol, propylene glycol, butanediol, pentanediol, hexanediol, glycerin, 1,1,1-trimethylolpropane, and other low molecular polyols. A condensation polymer of at least one selected from the group consisting of glutaric acid, adipic acid, pimelic acid, suberic acid, sebacic acid, dimer acid, other aliphatic carboxylic acids and oligomeric acids; Ring-opening polymers such as lactone and valerolactone; and the like.

  Specific examples of other polyols include, for example, polymer polyol, polycarbonate polyol; polybutadiene polyol; hydrogenated polybutadiene polyol; acrylic polyol; ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, butanediol, pentanediol, And low molecular weight polyols such as hexanediol.

Such polyol compounds can be used alone or in combination of two or more.
Among these, polypropylene ether diol and polypropylene ether triol are suitable for the viscosity of the urethane prepolymer obtained, and the elongation of the cured product comprising the resin composition of the present invention obtained using this urethane prepolymer. This is preferable because the strength is appropriate.

  In the present invention, the combination of the polyol compound and the polyisocyanate compound in producing the urethane prepolymer is selected from the group consisting of tolylene diisocyanate (TDI), xylylene diisocyanate (XDI) and diphenylmethane diisocyanate (MDI). A combination of at least one of the above and polypropylene ether diol and / or polypropylene ether triol is preferably exemplified.

  In the present invention, the amount of the polyisocyanate compound and the polyol compound when producing the urethane prepolymer is preferably such that the NCO group / OH group (equivalent ratio) is 1.2 to 2.5, More preferably, it is 1.5 to 2.2. When the equivalence ratio is within such a range, the viscosity of the obtained urethane prepolymer becomes appropriate, and the remaining amount of the unreacted polyisocyanate compound in the urethane prepolymer can be reduced.

  In this invention, the manufacturing method of a urethane prepolymer is not specifically limited, For example, it can manufacture by heating and stirring the polyol compound and polyisocyanate compound of the above-mentioned equivalent ratio at 50-130 degreeC. Moreover, if necessary, for example, a urethanization catalyst such as an organic tin compound, organic bismuth, or amine can be used.

  Such urethane prepolymers can be used alone or in combination of two or more.

<Polysulfide polymer>
The polysulfide polymer used in the resin composition of the present invention is a polysulfide polymer whose terminal is oxazolidine (hereinafter referred to as “oxazolidine-modified polysulfide”).

  In the present invention, the oxazolidine-modified polysulfide uses a polysulfide polymer having two or more thiol groups (SH groups) in one molecule (hereinafter referred to as “unmodified polysulfide”) as a starting material, and includes at least one oxazolidine-modified polysulfide. It can be produced by oxazolination of a thiol group.

As such a native polysulfide, specifically,
The main chain contains a structural unit represented by (1)-(C ₂ H ₄ OCH ₂ OC ₂ H ₄ —S _x ) — (where x is an integer of 1 to 5),
And (2) —C ₂ H ₄ OCH ₂ OC ₂ H ₄ —SH and / or a thiol group represented by —CH ₂ CH (OH) CH ₂ —SH at the end; Is done.

  The unmodified polysulfide represented by this specific example may contain a structural unit other than the structural unit represented by the above (1), but the structural unit represented by the above (1) has another structure. Even when the unit is contained, it is preferable to form 20% by mass or more.

  Commercially available products can be used as the unmodified polysulfide, and specific examples thereof include THIOPLAST G44 manufactured by AKZO NOBEL, etc. used in the examples.

  In the present invention, the number average molecular weight of the unmodified polysulfide is usually preferably 600 to 200,000, and more preferably 800 to 50,000.

In the present invention, as described above, the oxazolidine-modified polysulfide can be produced by oxazolization of the thiol group at the terminal of the unmodified polysulfide.
This production method is not particularly limited, and can be produced, for example, by reacting the unmodified polysulfide with a compound having a (meth) acryloyloxy group and an oxazolidine ring (Michael addition reaction).
Here, the compound having a (meth) acryloyloxy group and an oxazolidine ring used in this reaction includes, for example, a urethane acrylate having the following (meth) acryloyloxy group and an isocyanate group, and an oxazolidine compound having a hydroxyl group shown below. Can be produced by reacting (urethane).

(Urethane acrylate)
The urethane acrylate is a urethane compound having a (meth) acrylate group and an isocyanate group, obtained by reacting (urethane) a polyisocyanate compound and a poly (meth) acrylate having a hydroxyl group.
Here, specifically as a polyisocyanate compound, the polyisocyanate compound used for the production | generation of the urethane prepolymer mentioned above is mentioned, for example.
Specific examples of the poly (meth) acrylate having a hydroxyl group include ethylene glycol mono (meth) acrylate, propylene glycol (meth) acrylate, 1,3-propanediol mono (meth) acrylate, and 1,4. -Butanediol mono (meth) acrylate, 1,6-hexanediol mono (meth) acrylate, diethylene glycol mono (meth) acrylate, dipropylene glycol mono (meth) acrylate, polyethylene glycol mono (meth) acrylate, polypropylene glycol mono (meth) ) Mono (meth) acrylates of dihydric alcohols such as acrylates; trimethylolethane mono (meth) acrylate, trimethylolpropane mono (meth) acrylate, trimethylolethanebis (meth) T) acrylate, glycerol mono (meth) acrylate, mono (meth) acrylate or di (meth) acrylate of trihydric alcohols such as glycerol bis (meth) acrylate; bis (meth) acrylate, pentaerythritol bis (meth) acrylate, penta Bis or tris (meth) acrylates of polyhydric alcohols having a valence of 4 or more such as erythritol tris (meth) acrylate;

(Oxazolidine compound having a hydroxyl group)
The oxazolidine compound is an oxazolidine compound having a hydroxyl group that reacts with the isocyanate group of the urethane acrylate.
As such an oxazolidine compound, specifically, for example, 2-isopropyl-3- (2-hydroxyethyl) oxazolidine (hereinafter referred to as “hydroxyalkyloxazolidine (1)”), 3- (2-hydroxy). Ethyl) -2- (1-methylbutyl) oxazolidine (hereinafter referred to as “hydroxyalkyloxazolidine (2)”), 2-phenyl-3- (2-hydroxyethyl) oxazolidine (hereinafter referred to as “hydroxyalkyloxazolidine (3)”) ), 2- (p-methoxyphenyl) -3- (2-hydroxyethyl) oxazolidine (hereinafter referred to as “hydroxyalkyloxazolidine (4)”), 2- (2-methylbutyl) -3- (2-hydroxyethyl) -5-methyloxazolidine (hereinafter referred to as “hydroxyl And kill oxazolidine (5) ".), And the like.

  Moreover, as such an oxazolidine compound, the compound represented by a following formula (6) or (7) formula is also mentioned, for example.

（式中、ｎは０〜２の整数を表し、Ｒ¹は、水酸基または炭素数１〜１２の分岐していてもよいアルキル基もしくはアルコキシ基であり、ｎが２の場合のＲ¹は、それぞれ同一であっても異なっていてもよい。Ｒ²は、炭素数１〜６の分岐していてもよい、水酸基を有するアルキル基である。Ｒ³およびＲ⁴は、それぞれ独立に、水素原子、炭素数１〜６の分岐していてもよいアルキル基またはフェニル基である。）

(In the formula, n represents an integer of 0 to 2, R ¹ is a hydroxyl group or an alkyl group or an alkoxy group having 1 to 12 carbon atoms which may be branched, and R ¹ when n is 2, R ² is an alkyl group having a hydroxyl group, which may be branched, having 1 to 6 carbon atoms, and R ³ and R ⁴ are each independently a hydrogen atom. , An alkyl group having 1 to 6 carbon atoms, or a phenyl group.

  Specifically, as the compound represented by the above formula (6), a compound represented by the following formula (6a) or the like is suitably exemplified, and as a compound represented by the above formula (7), the following formula Preferred examples include compounds represented by (7a), (7b), and the like.

  Examples of the compound having a (meth) acryloyloxy group and an oxazolidine ring include various reactants of the urethane acrylate exemplified above and an oxazolidine compound having a hydroxyl group. Specifically, for example, the following formula (8) Preferred examples include the compounds represented.

  Examples of the oxazolidine-modified polysulfide include various reactants of the unmodified polysulfide and the compounds having the (meth) acryloyloxy group and oxazolidine ring exemplified above. Specifically, for example, the following formula (9) The compound etc. which are represented by these are mentioned.

The content of such oxazolidine-modified polysulfide is preferably 0.5 to 100 parts by mass and more preferably 1 to 50 parts by mass with respect to 100 parts by mass of the urethane prepolymer.
The content of such oxazolidine-modified polysulfide is preferably such that the equivalent ratio of isocyanate group of the urethane prepolymer to the oxazolidinyl group of the oxazolidine-modified polysulfide (isocyanate group / oxazolidinyl group) is 1 to 50. More preferably, it is ~ 20.
Here, the “oxazolidinyl group” means a monovalent group name of oxazolidine, and in the present invention, a hydrogen atom, a linear or branched alkyl group, an alicyclic alkyl group having 5 to 7 carbon atoms, carbon It may have a substituent such as an aryl group of several 6 to 10 in the oxazolidine ring.

In the present invention, by using such an oxazolidine-modified polysulfide, the storage stability and foam resistance of the resulting resin composition of the present invention are maintained well, and the durability is also good.
This is because the moisture (water) in the atmosphere is trapped by the oxazolidinyl group (oxazolidine ring) to suppress foaming due to the carbon dioxide removal reaction, and the polysulfide skeleton incorporated in the crosslinking is based on the urethane prepolymer described above. This is thought to be due to entering between the skeletons to reduce the cohesive strength of the cured product.

  The resin composition of the present invention has other additives such as a plasticizer, a filler, a curing catalyst, a thixotropy imparting agent, a silane coupling agent, a pigment, as long as the object of the present invention is not impaired as necessary. It may contain a dye, an antioxidant, an antioxidant, an antistatic agent, a flame retardant, a drying oil, an adhesion-imparting agent, a dispersant, a dehydrating agent, an ultraviolet absorber, a solvent, and the like.

Examples of the plasticizer include tetrahydrophthalic acid, azelaic acid, benzoic acid, phthalic acid, trimellitic acid, pyromellitic acid, adipic acid, sebacic acid, fumaric acid, maleic acid, itaconic acid, citric acid and derivatives thereof; And polyester, polyether, epoxy, paraffin, naphthene and aromatic process oils.
Of these, ester plasticizers such as phthalic acid plasticizers and adipic acid plasticizers are preferred.

Examples of the filler include organic or inorganic materials of various shapes, such as calcium carbonate, carbon black, silica (white carbon), clay talc, iron oxide, zinc oxide, titanium oxide, barium oxide, magnesium oxide, quick lime, Carbonates (eg, magnesium carbonate, zinc carbonate, pepper), alumina hydrate (eg, hydrous aluminum hydroxide), diatomaceous earth, barium sulfate (eg, precipitated barium sulfate), mica, alumina sulfate, lithopone, asbestos, Graphite, molybdenum disulfide, pumice powder, glass powder, silica sand, zeolite; surface treated products of these fatty acids, resin acids, fatty acid esters, higher alcohol addition isocyanate compounds, etc .; glass balloons; resin balloons;
Among these, it is preferable to use calcium carbonate because it is easily available and has excellent workability.

Specific examples of the thixotropic agent include aerosil (manufactured by Nippon Aerosil Co., Ltd.), disparon (manufactured by Enomoto Kasei Co., Ltd.), and the like.
Specific examples of the silane coupling agent include trimethoxyvinylsilane, γ-glycidoxypropyltrimethoxysilane, and the like.

Examples of the pigment include inorganic pigments and organic pigments.
Specific examples of inorganic pigments include, for example, zinc white, titanium oxide, dial, chrome oxide, iron black, composite oxides (for example, titanium yellow, zinc-iron brown, titanium / cobalt green, cobalt green). , Cobalt blue, copper-chromium black, copper-iron black), etc .; chromates such as chrome lead, molybdate orange; ferrocyanides such as bitumen; cadmium yellow, cadmium red, zinc sulfide, etc. Sulfides; sulfates such as barium sulfate; hydrochlorides; silicates such as ultramarine blue; carbonates such as calcium carbonate; phosphates such as manganese violet; hydroxides such as yellow iron oxide; carbons such as carbon black; Metal powder such as aluminum powder and bronze powder; titanium-coated mica;

  Specific examples of organic pigments include monoazo lakes (for example, Lake Red C, Permanen Red 2B, Brilliant Carmine 6B), monoazo (for example, Toluidine Red, Naphthol Red, Fast Yellow G, Benzimidazole Bordeaux). Benzimidazolone brown), disazo series (for example, disazo yellow AAA, disazo yellow HR, pyrazolone red), condensed azo series (for example, condensed azo yellow, condensed azo red, condensed azo brown), metal complex azo series (for example, nickel azo yellow) Azo pigments such as: copper phthalocyanine blue, copper phthalocyanine green, brominated copper phthalocyanine green, and other phthalocyanine pigments; dyes such as basic dye lakes (for example, rhodamine 6 lake); anthraquinone (examples) For example, flavanthrone yellow, dianslaquinolyl red, indanthrene blue), thioindigo (eg, thioindigo Bordeaux), perinone (eg, perinone orange), perylene (eg, perylene scarlet, perylene red, perylene) Maroon), quinacridone series (eg, quinacridone red, quinacridone magenta, quinacridone scarlet), dioxazine series (eg, dioxazine violet), isoindolinone series (eg, isoindolinone yellow), quinophthalone series (eg, quinophthalone yellow), Condensed polycyclic pigments such as isoindoline (for example, isoindoline yellow) and pyrrole (for example, pyrrole red); metal complex azomethine such as copper azomethine yellow; aniline black; daylight fluorescence Fee; and the like.

Specific examples of the dye include direct dyes, vat dyes, sulfur dyes, naphthol dyes, acid dyes, and disperse dyes.
Specific examples of the antioxidant include N, N′-diphenyl-p-phenylenediamine (DPPD), N, N′-dinaphthyl-p-phenylenediamine (DNPD), 2,2,4-trimethyl- Examples include 1,3-dihydroquinoline (TMDQ), N-phenyl-1-naphthylamine (PAN), and hindered phenol compounds.
Specific examples of the antioxidant include hindered phenol compounds such as butylhydroxytoluene (BHT) and butylhydroxyanisole (BHA); triphenyl phosphite: and the like.
Specific examples of the antistatic agent include ionic compounds such as quaternary ammonium salts and amines; hydrophilic compounds such as polyglycols and ethylene oxide derivatives; and the like.
Specific examples of the flame retardant include chloroalkyl phosphate, dimethylmethylphosphonate, bromine / phosphorus compound, ammonium polyphosphate, diethylbishydroxyethylaminophosphate, neopentyl bromide polyether, brominated polyether, and the like. It is done.
Specific examples of the drying oil include linseed oil, soybean oil, dehydrated castor oil, and tung oil.

Specific examples of the adhesion-imparting agent include terpene resins, phenol resins, terpene-phenol resins, rosin resins, xylene resins, and various silane coupling agents.
Specific examples of the dispersant include fatty acid metal salts such as calcium stearate, magnesium stearate, lithium stearate, zinc stearate, aluminum stearate, calcium linoleate, magnesium hydroxystearate; ethyl stearate, lauric acid And fatty acid esters such as ethyl, butyl oleate, dioctyl adipate, and monoglyceride stearate;
Specific examples of the dehydrating agent include methyl stearoxypolysiloxane.
Specific examples of ultraviolet absorbers include, for example, benzophenone ultraviolet absorbers, benzotriazole ultraviolet absorbers, hindered phenol ultraviolet absorbers, salicylate ultraviolet absorbers, cyanoacrylate ultraviolet absorbers, and oxalic acid. Examples include anilide ultraviolet absorbers, formamidine ultraviolet absorbers, triazine ring ultraviolet absorbers, and nickel complex ultraviolet absorbers.
Specific examples of the solvent include hydrocarbons such as hexane and toluene; halogenated hydrocarbons such as tetrachloromethane; ketones such as acetone and methyl ethyl ketone; ethers such as diethyl ether and tetrahydrofuran; ethyl acetate. And ester systems such as

  The method for producing the resin composition of the present invention is not particularly limited. For example, the urethane prepolymer, the oxazolidine-modified polysulfide, and a polysiloxane derivative that may be optionally added and various additives are mixed, and a roll, a kneader, It can be produced by sufficiently mixing and uniformly dispersing (kneading) at room temperature or under heating (40 to 60 ° C., for example, 40 ° C.) using an extruder, a universal stirrer, or the like.

  Hereinafter, the present invention will be specifically described with reference to examples. However, the present invention is not limited to these.

<Synthesis of Urethane Prepolymer 1>
Polyether polyol (average hydrogen group value 44), which is a mixture of 1000 g of polyoxypropylene diol (hydroxyl value 56.1) having a number average molecular weight of 2,000 and 1000 g of polyoxypropylene triol (hydroxyl value 33.7) having a number average molecular weight of 5,000. .9) was added 952 g of a phthalate ester plasticizer (trade name: DIDP, manufactured by Shin Nippon Rika Co., Ltd.), and 380.3 g of MDI was reacted so that the ratio of NCO / OH = 1.9. thing. The final NCO% was 1.82%.

<Synthesis of Oxazolidine Modified Polysulfide 1>
In 200 g of toluene, 193.2 g (1.0 mol) of 2-phenyl-3- (2-hydroxyethyl) oxazolidine represented by the above formula (3) and 141.1 g (1.0 mol) of 2-isocyanatoethyl acrylate were added. The compound represented by the above formula (6) was prepared in a reaction vessel by heating at reflux at 135 ° C. and reacting for 4 hours.
Subsequently, 471.4 g (1.0 mol) of unmodified polysulfide (trade name: THIOPLAST G44, SH value: 7.0%, manufactured by AKZO NOBEL) was added, and after heat vulcanization at 135 ° C., toluene 100 was added. By removing under reduced pressure at 0 ° C., 805.7 g of oxazolidine-modified polysulfide 1 represented by the above formula (7) was obtained.

(Example 1 and Comparative Examples 1-2)
Each urethane resin composition was obtained by mixing the urethane prepolymer 1 obtained above and oxazolidine-modified polysulfide 1 and the like at a mass ratio shown in Table 1 below.

  The workability, storage stability, foam resistance and durability of each obtained urethane resin composition were measured and evaluated by the measurement methods shown below. The results are shown in Table 1 below.

<Workability>
The viscosity (Pa · s) at a rotational speed of 1 rpm and 10 rpm at 23 ° C. and 50% RH (relative humidity) immediately after the preparation of each urethane resin composition obtained was measured with a B-type viscometer.
The thixo index (TI) was determined from the ratio of the viscosity at 1 rpm to the viscosity at 10 rpm (TI 1/10).
As a result, if the value of the thixo index (TI) is 6.0 or more, it can be evaluated that the resin composition is excellent in workability.

<Storage stability>
About each obtained resin composition, the thixo index (TI 1/10) after 1 day curing at 70 degreeC was measured by the method similar to evaluation of workability | operativity.
As a result, if the value of the thixo index (TI) is 5.0 or more, it can be evaluated that the resin composition is excellent in storage stability.

<Foaming resistance>
50 g of each obtained resin composition was filled in a cylindrical paper cup (diameter: 50 mm, capacity: 100 ml) so as not to entrain bubbles, and placed in a constant temperature and humidity chamber at 40 ° C. and 90% RH (relative humidity). It was left to cure for 3 days.
After curing, the cured product was taken out from the constant temperature and humidity chamber, and the foamed state was observed visually.
The confirmation of the foaming state is performed by cutting the cured product in the vertical direction and confirming the presence or absence of bubbles present inside, evaluating what is found to be a lot of foaming as `` x '', whether foaming is not observed, Very few were evaluated as “◯”.

<Durability>
The durability classification (9030) described in JIS A5758: 2004 “Building Sealant” was measured and evaluated by the method described in JIS A1439.
Here, it is evaluated as ◯ that the test specimen after the test is not peeled or cracked is excellent in durability, and the specimen that is peeled off or cracked after the test is inferior in durability. X was evaluated.
In Comparative Example 2, since the modulus after curing was low and rubber physical properties could not be obtained, the durability test could not be performed.

The following were used for each component in Table 1 above.
Urethane prepolymer 1: Urethane prepolymer 1 synthesized above
・ Vinylsilane: Trimethoxyvinylsilane (A171, manufactured by Nihon Unicar)
Oxazolidine modified polysulfide 1: Oxazolidine modified polysulfide 1 synthesized above
Unmodified polysulfide 1: Thiocol (THIOPLAST G44, SH value: 7.0%, manufactured by AKZO NOBEL)
・ Calcium carbonate: Fatty acid ester-treated calcium carbonate (Sealet 200, manufactured by Maruo Calcium Co., Ltd.)
・ Solvent: A solvent (manufactured by Nippon Oil Corporation)

As can be seen from Table 1, the resin composition (Example 1) containing oxazolidine-modified polysulfide together with urethane prepolymer can maintain storage stability and foam resistance well, and has excellent durability. It was.
On the other hand, it was found that the resin composition not containing oxazolidine-modified polysulfide (Comparative Example 1) was excellent in storage stability but was inferior in publication resistance and durability.
In addition, it was found that the resin composition (Comparative Example 2) containing unmodified polysulfide instead of oxazolidine-modified polysulfide is inferior in storage stability and foam resistance, and rubber properties cannot be obtained.

Claims (3)

A urethane prepolymer having an isocyanate group at the molecular end ;
A urethane resin composition comprising: a polysulfide polymer having a terminal oxazolidine.   The urethane resin composition according to claim 1, wherein the content of the polysulfide polymer is 0.5 to 100 parts by mass with respect to 100 parts by mass of the urethane prepolymer.   The urethane resin composition according to claim 1 or 2, wherein an equivalent ratio (isocyanate group / oxazolidinyl group) of an isocyanate group of the urethane prepolymer to an oxazolidinyl group of the polysulfide polymer is 1 to 50.