JP2015209468A - Curable resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a curable resin composition whose surface tack after curing is reduced and which has excellent surface weather resistance.SOLUTION: The curable resin composition is provided which contains a urethane prepolymer (A) and a hydrocarbon-based compound (B), and in which: the urethane prepolymer (A) is obtained by reacting a mixture of a hydroxyl group-containing polysulfide polymer having hydroxyl groups (a1) and a polyoxyalkylene polyol (a2) with a polyisocyanate compound (a3); the hydrocarbon-based compound (B) is at least one selected from the group consisting of linear saturated hydrocarbons, polyolefin-based compounds, and ester-based compound containing no aromatic rings, and is a compound having a melting point of 40 to 160°C and an iodine value of 14 or less; and a content of the hydrocarbon-based compound (B) is 0.1 to 10 pts.mass relative to 100 pts.mass of the urethane prepolymer (A).

Description

  The present invention relates to a curable resin composition.

  As a curable composition containing a urethane prepolymer, for example, Patent Document 1 discloses that “a reaction of a polysulfide polymer having a thiol group with a hydroxyl-terminated polyalkylene glycol mono (meth) acrylate and / or a hydroxyalkyl (meth) acrylate”. The urethane prepolymer (D) obtained by reacting the polyisocyanate compound (C) with the resulting mixture of the hydroxy group-containing polysulfide polymer (A) having a hydroxy group and the polyoxyalkylene polyol (B) is contained. A curable composition containing "a urethane prepolymer mixture" is described ([Claim 1] and [Claim 5]).

JP 2011-127027 A

  The present inventor blended a dry oil for the purpose of reducing surface tack with respect to the curable composition described in Patent Document 1, and although the surface tack after curing is improved, the weather resistance may be inferior. It was made clear.

  Then, this invention makes it a subject to provide the curable resin composition which the surface tack after hardening is reduced and is excellent also in the weather resistance of a surface.

As a result of intensive studies to solve the above problems, the present inventor reduced the surface tack after curing by blending a specific amount of a predetermined hydrocarbon compound having specific physical properties with respect to a predetermined urethane prepolymer. As a result, the present inventors have found that the weather resistance of the surface is also good and completed the present invention.
That is, the present inventor has found that the above problem can be solved by the following configuration.

[1] A curable resin composition containing a urethane prepolymer (A) and a hydrocarbon-based compound (B),
The urethane prepolymer (A) is a urethane prepolymer obtained by reacting a polyisocyanate compound (a3) with a mixture of a hydroxyl group-containing polysulfide polymer (a1) having a hydroxyl group and a polyoxyalkylene polyol (a2). Yes,
The hydrocarbon compound (B) is at least one selected from the group consisting of chain saturated hydrocarbons, polyolefin compounds, and ester compounds not containing an aromatic ring, and has a melting point of 40 to 160 ° C. And the iodine value is 14 or less,
Curable resin composition whose content of the said hydrocarbon type compound (B) is 0.1-10 mass parts with respect to 100 mass parts of said urethane prepolymers (A).
[2] The curable resin composition according to [1], wherein the polyolefin compound is a wax having a viscosity average molecular weight of 800 to 8000 and a melting point of 90 to 120 ° C.
[3] The curable resin composition according to [1], wherein the chain saturated hydrocarbon has 20 to 40 carbon atoms and has a melting point of 42 to 70 ° C.
[4] The curable resin composition according to [1], wherein the ester compound is represented by the following formula (I) and has a melting point of 75 to 100 ° C.
R ¹ —COO—R ² (I)
(R ¹ represents a monovalent hydrocarbon group having 25 to 35 carbon atoms, and R ² represents a monovalent hydrocarbon group having 25 to 35 carbon atoms.)
[5] The curable resin composition according to [1] or [4], wherein the ester compound is carnauba wax.
[6] The curable resin composition according to [1] or [2], wherein the polyolefin-based compound is polyethylene.
[7] The curable resin composition according to any one of [1] to [6], further comprising an oxazolidine compound (C).

  ADVANTAGE OF THE INVENTION According to this invention, the surface tack after hardening is reduced and the curable resin composition which is excellent also in the surface weather resistance can be provided.

Hereinafter, the present invention will be described in detail.
The description of the constituent elements described below may be made based on typical embodiments of the present invention, but the present invention is not limited to such embodiments.
In the present specification, a numerical range expressed using “to” means a range including numerical values described before and after “to” as a lower limit value and an upper limit value.

  The curable resin composition of the present invention contains a urethane prepolymer (A) and a hydrocarbon compound (B), and the urethane prepolymer (A) includes a hydroxyl group-containing polysulfide polymer (a1) having a hydroxyl group. , A urethane prepolymer obtained by reacting a mixture with a polyoxyalkylene polyol (a2) with a polyisocyanate compound (a3), wherein the hydrocarbon compound (B) is a chain saturated hydrocarbon, a polyolefin-based polymer A compound having at least one selected from the group consisting of a compound and an ester compound not containing an aromatic ring, having a melting point of 40 to 160 ° C. and an iodine value of 14 or less, The content of the hydrogen-based compound (B) is 0.1 to 10 mass with respect to 100 mass parts of the urethane prepolymer (A). A curable resin composition is.

In this invention, as above-mentioned, the surface tack after hardening is mix | blended by mix | blending 0.1-10 mass parts of said hydrocarbon type compounds (B) with respect to 100 mass parts of said urethane prepolymers (A). And the weather resistance of the surface is improved.
Although this is not clear in detail, the present inventors presume as follows.
That is, as shown in Comparative Example 2 described later, when dry oil (Tung oil) is blended in place of the hydrocarbon compound (B), it can be seen that the weather resistance is inferior. This is considered to be because the unsaturated bond remaining in the film formed by bleeding out the drying oil has an adverse effect on the weather resistance because the iodine value is high.
Therefore, by blending the hydrocarbon compound (B), the surface tack is reduced by the film formed by bleeding out, and this film does not adversely affect the excellent weather resistance of the urethane resin. It is believed that there is.
Hereinafter, the urethane prepolymer (A), the hydrocarbon compound (B), the arbitrary oxazolidine compound (C) and the like will be described in detail.

[Urethane prepolymer (A)]
The urethane prepolymer (A) contained in the curable resin composition of the present invention contains a polyisocyanate compound (a3) in a mixture of a hydroxyl group-containing polysulfide polymer (a1) having a hydroxyl group and a polyoxyalkylene polyol (a2). It is a urethane prepolymer partially having a polysulfide skeleton obtained by reacting.
Moreover, the said urethane prepolymer (A) can contain 0.5-5 mass% NCO group in a molecule terminal.

<Hydroxyl-containing polysulfide polymer (a1)>
The hydroxyl group-containing polysulfide polymer (a1) is a polysulfide polymer having a thiol group and a hydroxyl group-terminated polyalkylene glycol mono (meth) acrylate and / or hydroxyalkyl (meth) as in Patent Document 1 (Japanese Patent Laid-Open No. 2011-127027). Although it may be a reaction product with an acrylate, as shown in the following reaction formula (1), a reaction product of a polysulfide polymer having a thiol group (the following formula (I)) and an epoxy compound (the following formula (II)) It may be.

In the reaction formula (1), each R ₁ independently represents C ₂ H ₄ OCH ₂ OC ₂ H ₄ or an alkylene group having 1 to 12 carbon atoms. R ₂ independently represents an aliphatic group or an aromatic group having 1 or more carbon atoms, preferably 2 to 10 carbon atoms, and may contain an element other than carbon such as oxygen, nitrogen, or halogen in the molecule. A saturated bond may be included. Each x independently represents an integer of 1 to 5, and each n independently represents an integer of 1 to 1500.

In the reaction formula (1), the smaller R ₂ is, the higher the reactivity is. In addition, the larger the R ₂ , the more stable the urethane bond. R ₂ preferably has 4 or more carbon atoms from the reason that the adhesiveness is improved and the weather resistance of the surface after curing is further improved.

  The number average molecular weight of the hydroxyl group-containing polysulfide polymer (a1) is 270 or more, preferably 1000 or more and 5000 or less. Adhesiveness can be improved as the number average molecular weight is within the above range.

(Polysulfide polymer having a thiol group)
Examples of the polysulfide polymer having a thiol group include polysulfide polymers described in paragraphs [0009] to [0015] of Patent Document 1 (Japanese Patent Laid-Open No. 2011-127027).

(Epoxy compound)
The epoxy compound is not particularly limited as long as it is a compound having one glycidyl group (monofunctional glycidyl group-containing compound). Specific examples thereof include methyl glycidyl ether, ethyl glycidyl ether, butyl glycidyl ether, and tert-butyl. Glycidyl ether, phenyl glycidyl ether, 2-ethylhexyl glycidyl ether, decyl glycidyl ether, stearyl glycidyl ether, allyl glycidyl ether, 2-methyloctyl glycidyl ether, methoxy polyethylene glycol monoglycidyl ether, ethoxy polyethylene glycol monoglycidyl ether, butoxy polyethylene glycol mono Glycidyl ether, phenoxy polyethylene glycol monoglycidyl ether, p-tertiary Butylphenyl glycidyl ether, sec-butylphenyl glycidyl ether, n-butylphenyl glycidyl ether, phenylphenol glycidyl ether, cresyl glycidyl ether, dibromocresyl glycidyl ether, and the like may be used alone, Two or more kinds may be used in combination.

(reaction)
The reaction between the polysulfide polymer having a thiol group and the epoxy compound is not particularly limited. For example, these components are used in the absence of a solvent or in a solvent using a basic catalyst such as sodium hydroxide, potassium hydroxide, or tertiary amine. And a method of stirring at 0 to 100 ° C. for 1 to 12 hours.

<Polyoxyalkylene polyol (a2)>
Examples of the polyoxyalkylene polyol (a2) include the polyoxyalkylene polyol (B) described in paragraphs [0032] to [0035] of Patent Document 1 (Japanese Patent Application Laid-Open No. 2011-127027). Specifically, polyoxyethylene diol, polyoxyethylene triol, polyoxypropylene diol, polyoxypropylene triol and the like can be mentioned.

<Polyisocyanate compound (a3)>
The polyisocyanate compound (a3) is not particularly limited as long as it has two or more isocyanate groups in the molecule.
Specific examples of the polyisocyanate compound (a3) include TDI (for example, 2,4-tolylene diisocyanate (2,4-TDI), 2,6-tolylene diisocyanate (2,6-TDI), for example. ), MDI (for example, 4,4′-diphenylmethane diisocyanate (4,4′-MDI), 2,4′-diphenylmethane diisocyanate (2,4′-MDI)), 1,4-phenylene diisocyanate, polymethylene polyphenylene poly Aromatic polyisocyanates such as isocyanate, xylylene diisocyanate (XDI), tetramethylxylylene diisocyanate (TMXDI), tolidine diisocyanate (TODI), 1,5-naphthalene diisocyanate (NDI), triphenylmethane triisocyanate; Aliphatic polyisocyanates such as methylene diisocyanate (HDI), trimethylhexamethylene diisocyanate (TMHDI), lysine diisocyanate, norbornane diisocyanate (NBDI); transcyclohexane-1,4-diisocyanate, isophorone diisocyanate (IPDI), bis (isocyanate methyl) And cycloaliphatic polyisocyanates such as cyclohexane (H ₆ XDI) and dicyclohexylmethane diisocyanate (H ₁₂ MDI); these carbodiimide-modified polyisocyanates; these isocyanurate-modified polyisocyanates;

Such polyisocyanate compounds (a3) can be used alone or in combination of two or more.
Among these, the curable resin composition of the present invention containing the urethane prepolymer (A) to be obtained has a high shear modulus after curing and good adhesiveness under high temperature and high humidity. Group polyisocyanates are preferred, TDI and MDI are more preferred, and MDI is even more preferred.

<Reaction>
The method for reacting the polyisocyanate compound (a3) with the mixture of the hydroxyl group-containing polysulfide polymer (a1) and the polyoxyalkylene polyol (a2) is not particularly limited, and is not particularly limited as long as it is in a wet condition.
The above reaction can be carried out in the absence of a solvent or in a solvent, and can be carried out without a catalyst or by using a urethanization catalyst such as an organic tin compound, organic bismuth, or amine.

[Hydrocarbon compound (B)]
The hydrocarbon compound (B) contained in the curable resin composition of the present invention is at least one selected from the group consisting of chain saturated hydrocarbons, polyolefin compounds, and ester compounds not containing an aromatic ring. The melting point is 40 to 160 ° C., and the iodine value is 14 or less.
The melting point is the temperature of the melting peak of the DSC curve obtained by measuring a temperature range of −30 ° C. to 200 ° C. under a temperature rising rate of 10 ° C./min using a differential scanning calorimeter (DSC). .
Further, the iodine value is a value obtained by converting the amount of halogen bound to 100 grams of a sample into grams of iodine and measured by a potentiometric titration method (JIS K 0070: 1992). .

<Chain saturated hydrocarbon>
The chain saturated hydrocarbon is a chain compound (so-called paraffin) that includes a carbon atom and a hydrogen atom and does not have a double bond in a carbon-carbon bond.
In the present invention, the chain saturated hydrocarbon has a carbon number of 20 to 40 and a melting point of 42 to 42 because the surface tack after curing is further reduced and the weather resistance of the surface becomes better. Alkanes that are 70 ° C. are preferred.

  Specific examples of the chain saturated hydrocarbon include paraffin wax (melting point: 45 to 70 ° C., iodine value: 0).

<Polyolefin compounds>
The polyolefin compound is a polymer synthesized using an alkene (olefin) having a double bond in at least one of carbon-carbon bonds as a monomer.
In the present invention, the polyolefin compound has a viscosity average molecular weight of 800 to 8000 and a melting point of 90 to 120 ° C. because the surface tack after curing is further reduced and the weather resistance of the surface becomes better. Some waxes are preferred.
Here, the viscosity average molecular weight means an average molecular weight according to a viscosity method (ASTM D2857).

  Specific examples of the polyolefin compound include low density polyethylene (viscosity average molecular weight: 1000 to 8000, melting point: 105 to 130 ° C., iodine value: 10 or less), and high density polyethylene (viscosity average molecular weight: 900 to 8000, melting point: 110 to 130 ° C., iodine value: 10 or less).

<Ester compound>
The ester compound is a compound obtained by dehydration condensation of an organic acid (for example, carboxylic acid such as formic acid, acetic acid, citric acid, oxalic acid, sulfonic acid, etc.) and an alcohol. A compound not included.
In the present invention, the ester compound is preferably represented by the following formula (I) and has a melting point of 75 to 100 ° C. because the surface tack after curing is further reduced.
R ¹ —COO—R ² (I)
(R ¹ represents a monovalent hydrocarbon group having 25 to 35 carbon atoms, and R ² represents a monovalent hydrocarbon group having 25 to 35 carbon atoms.)

In the above formula (I), the hydrocarbon group of R ¹ and R ² is preferably an alkyl group having 25 to 35 carbon atoms which may be branched, for example, a linear alkyl group. Is more preferable.

  Specific examples of the ester compound include carnauba wax (melting point: 80 to 86 ° C., iodine value: 5 to 14).

In the present invention, the melting point of the hydrocarbon compound (B) is preferably 45 to 120 ° C, more preferably 45 to 70 ° C, because the weather resistance becomes better.
For the same reason, the iodine value of the hydrocarbon compound (B) is preferably 10 or less, and more preferably 0.
In particular, the hydrocarbon compound (B) is more preferably paraffin wax.

In this invention, content of the said hydrocarbon type compound (B) is 0.10-10 mass parts with respect to 100 mass parts of said urethane prepolymers (A), and is 0.5-5 mass parts. Is preferable, and it is more preferable that it is 1-3 mass parts.
When the content of the hydrocarbon compound (B) is in the above range, as described above, the surface tack after curing of the curable resin composition of the present invention obtained is reduced, and the weather resistance of the surface is also good. Become.

[Oxazolidine compound (C)]
The curable resin composition of the present invention preferably contains an oxazolidine compound (C) because foaming during curing can be suppressed.
The oxazolidine compound (C) is not particularly limited as long as it is a compound having at least one active hydrogen group and one oxazolidine ring in the molecule.

  As said oxazolidine compound (D), a urethane oxazolidine compound, N-hydroxyalkyl oxazolidine etc. are mentioned, for example.

  The urethane oxazolidine compound can be obtained by reacting a hydroxyalkyl oxazolidine compound with a polyisocyanate compound. Specific examples thereof are described in paragraph [0046] of Patent Document 1 (Japanese Patent Application Laid-Open No. 2011-127027). And those represented by the formulas (I) to (VI).

The N-hydroxyalkyloxazolidine can be prepared, for example, by a dehydration condensation reaction between an alkanolamine and a ketone or aldehyde.
Specific examples of such N-hydroxyalkyloxazolidine include 2-isopropyl-3- (2-hydroxyethyl) oxazolidine, 3- (2-hydroxyethyl) -2- (1-methylbutyl) oxazolidine, 2-phenyl-3- (2-hydroxyethyl) oxazolidine (hereinafter also referred to as “PHO”), 2- (p-methoxyphenyl) -3- (2-hydroxyethyl) oxazolidine, 2- (1-methylbutyl) -3- (2-hydroxypropyl) -5-methyloxazolidine and the like.

  In this invention, it is preferable that content in the case of containing an oxazolidine compound (C) is 0.3-10 mass parts with respect to 100 mass parts of said urethane prepolymers (A), 0.5- It is more preferably 8 parts by mass.

[Other optional ingredients]
The curable resin composition of the present invention is a filler, a plasticizer, an anti-aging agent, an antioxidant, a solvent, a pigment (dye), a thixotropic agent, as long as the purpose of the present invention is not impaired as necessary. Various additives such as an ultraviolet absorber, a flame retardant, a surfactant (including a leveling agent), a dispersant, a dehydrating agent, an adhesion-imparting agent, and an antistatic agent can be contained.

  Examples of the filler include organic or inorganic fillers having various shapes. Specifically, for example, fumed silica, calcined silica, precipitated silica, ground silica, fused silica; diatomaceous earth; iron oxide, zinc oxide, titanium oxide, barium oxide, magnesium oxide; calcium carbonate, heavy calcium carbonate, precipitated Calcium carbonate (light calcium carbonate), colloidal calcium carbonate, magnesium carbonate, zinc carbonate; wax stone clay, kaolin clay, calcined clay; these fatty acid treated products, resin acid treated products, urethane compound treated products, fatty acid ester treated products; These may be used, and these may be used alone or in combination of two or more.

  Specific examples of the plasticizer include diisononyl phthalate (DINP); dioctyl adipate, isodecyl succinate; diethylene glycol dibenzoate, pentaerythritol ester; butyl oleate, methyl acetylricinoleate; tricresyl phosphate, trioctyl phosphate Adipic acid propylene glycol polyester, adipic acid butylene glycol polyester, etc. may be mentioned, and these may be used alone or in combination of two or more.

Specific examples of the anti-aging agent include hindered phenol compounds.
Specific examples of the antioxidant include butylhydroxytoluene (BHT) and butylhydroxyanisole (BHA).
Examples of the solvent include ketones such as methyl ethyl ketone (MEK), methyl isobutyketone (MIBK), and cyclohexanone; alcohols such as propylene glycol monomethyl ether (PGME) and isopropyl alcohol (IPA); cycloalkanes such as cyclohexane. An aromatic hydrocarbon compound such as toluene, xylene, benzyl alcohol;

  Specific examples of the pigment include inorganic pigments such as titanium oxide, zinc oxide, ultramarine, bengara, lithopone, lead, cadmium, iron, cobalt, aluminum, hydrochloride, sulfate, etc .; azo pigment, phthalocyanine pigment, quinacridone Pigment, quinacridone quinone pigment, dioxazine pigment, anthrapyrimidine pigment, ansanthrone pigment, indanthrone pigment, flavanthrone pigment, perylene pigment, perinone pigment, diketopyrrolopyrrole pigment, quinonaphthalone pigment, anthraquinone pigment, thioindigo pigment, benzimidazolone And organic pigments such as pigments, isoindoline pigments, and carbon black.

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 adhesion-imparting agent include terpene resins, phenol resins, terpene-phenol resins, rosin resins, xylene resins, and the like.

Specific examples of the flame retardant include chloroalkyl phosphate, dimethyl / methyl phosphonate, bromine / phosphorus compound, ammonium polyphosphate, neopentyl bromide-polyether, brominated polyether, and the like.
Specific examples of the antistatic agent include quaternary ammonium salts; hydrophilic compounds such as polyglycols and ethylene oxide derivatives.

  The method for producing the curable resin composition of the present invention is not particularly limited. For example, the urethane prepolymer (A) and the hydrocarbon-based compound (B) described above and the oxazolidine compound (C) that may be optionally added and By mixing various additives, mixing thoroughly at room temperature or under heating (40-60 ° C., for example 40 ° C.) using a roll, kneader, extruder, universal stirrer, etc., and uniformly dispersing (kneading) Can be manufactured.

  Hereinafter, the present invention will be described in more detail based on examples. The materials, amounts used, ratios, processing details, processing procedures, and the like shown in the following examples can be changed as appropriate without departing from the spirit of the present invention. Therefore, the scope of the present invention should not be construed as being limited by the following examples.

[Synthesis of Urethane Prepolymer (A1)]
In a 1 L glass container, 500 g of a polysulfide polymer having a thiol group (G44, manufactured by Tioplast), 130.1 g of butyl glycidyl ether, and 0.5 g of triethylamine as an amine catalyst are added and reacted at 100 ° C. for 4 hours. Thus, a hydroxyl group-containing polysulfide polymer (a1-1) was prepared.

1000 g of polyoxypropylene diol (EXCENOL 2020, hydroxyl value: 56.1, number average molecular weight: 2000, manufactured by Asahi Glass Co., Ltd.) and polyoxypropylene triol (EXCENOL 5030, hydroxyl value: 33.7, number average molecular weight: 5000, manufactured by Asahi Glass Co., Ltd. ) 500 g of the previously prepared hydroxyl-containing polysulfide polymer (a1-1) was added to the polyether polyol (average hydrogen group value 44.9) which was a mixture with 1000 g, and kneaded to prepare a mixture.
A urethane prepolymer (A1) was synthesized by adding 500 g of diphenylmethane diisocyanate (MDI) to 2500 g of the prepared mixture, kneading and reacting at 95 ° C.

[Synthesis of Urethane Prepolymer (X1)]
1000 g of polyoxypropylene diol (EXCENOL 2020, hydroxyl value: 56.1, number average molecular weight: 2000, manufactured by Asahi Glass Co., Ltd.) and polyoxypropylene triol (EXCENOL 5030, hydroxyl value: 33.7, number average molecular weight: 5000, manufactured by Asahi Glass Co., Ltd. ) Synthesis of urethane prepolymer (X1) by adding 500 g of diphenylmethane diisocyanate (MDI) to polyether polyol (average hydrogen group value 44.9), which is a mixture with 1000 g, and kneading and reacting at 95 ° C. did.

[Examples 1 to 10 and Comparative Examples 1 to 5]
Along with the urethane prepolymer (A1) or urethane prepolymer (X1) described above, the components shown in Table 1 below were mixed using the stirrer with the composition (parts by mass) shown in the same table to prepare a composition. .
About each prepared composition, evaluation shown below was performed by the method shown below. These results are shown in Table 1 below.

<With or without foaming>
Each prepared composition was cured at 40 ° C. for 3 days and cured.
The state of the obtained cured product was visually confirmed, and the case where there was no foaming mark on the cured product surface was evaluated as “◯”, and the case where the cured product surface had foaming marks was evaluated as “x”.

<Adhesiveness>
As the adherend, an aluminum substrate (H type) on which an acrylic resin was electrodeposited was used.
Each prepared composition was applied to the adherend, cured for 7 days under conditions of 23 ° C. and 50% relative humidity, and cured.
After curing, a 90 ° peel test (peel test) of each cured product was performed to evaluate the fracture state. In Table 1 below, the cohesive failure is evaluated as "CF" as having excellent adhesiveness, the interface peeled is evaluated as "AF" as being poor in adhesiveness, and the one peeled off by foaming marks is bonded. It was evaluated as “AF (foaming)” as being inferior in properties.

<Surface tack>
Each prepared composition was examined for surface tack after curing for 7 days at 23 ° C. and 50% relative humidity.
The presence / absence of surface tack was confirmed by touching the surface with a finger, the case having no surface tack was evaluated as “◯”, and the case having surface tack was evaluated as “×”. In Table 1 below, “-” indicates that a wax-like product is deposited on the surface of the cured product and cannot be used practically, so that evaluation is not performed. The same applies to surface contamination and surface weather resistance.

<Surface contamination>
Each of the prepared compositions was cured and cured for 7 days under the conditions of 23 ° C. and 50% relative humidity.
The obtained cured product was left outdoors for one month, and the surface condition after one month was visually confirmed.
The case where there was no noticeable stain on the surface of the cured product was evaluated as “◯”, and the case where conspicuous stain was confirmed on the surface of the cured product was evaluated as “x”.

<Surface weather resistance>
Each of the prepared compositions was formed into a sheet having a thickness of 3 mm, and cured for 7 days under the conditions of 23 ° C. and 50% relative humidity to prepare a test piece.
This test piece was treated with a metal halide weather meter (conditions: 63 ° C., 50% RH, light energy 75 mW / cm ² , shower 120 seconds / 2 hours later), and the state of the cured product surface was visually observed after 200 hours. The weather resistance was evaluated based on the presence or absence of abnormalities such as surface cracks and discoloration.
Those having no abnormality on the surface of the cured product were evaluated as “◯”, and those having an abnormality on the surface of the cured product were evaluated as “x”.

The details of each component shown in Table 1 are as follows.
Urethane prepolymer (A1): Synthetic product described above Urethane prepolymer (X1): Synthetic product described above Hydrocarbon compound (B1): Paraffin wax (BYK-S780, melting point: 46-68 ° C., iodine value: 0, manufactured by Big Chemie)
Hydrocarbon compound (B2): Olefin wax (110P, viscosity average molecular weight: 1000, melting point: 109 ° C., iodine value: 10 or less, manufactured by Mitsui Chemicals)
Hydrocarbon compound (B3): Carnauba wax (CERACOL79, melting point: 90 ° C., iodine value: 9, manufactured by Big Chemie)
Drying oil: Tung oil (melting point: -17 to 21 ° C., iodine value: 160, manufactured by Cosmo)

Oxazolidine compound: 2-phenyl-3- (2-hydroxyethyl) oxazolidine (PHO, manufactured by Yokohama Rubber Co., Ltd.)
・ Calcium carbonate: Sealets 200 (Maruo Calcium)
・ Solvent: A solvent (manufactured by JX Nippon Oil & Energy Corporation)
Anti-aging agent: hindered amine light stabilizer (HALS, manufactured by Adeka)
・ Plasticizer: Diisononyl phthalate (DINP, Shin Nippon Chemical Co., Ltd.)

As is clear from the results shown in Table 1, it was found that the surface tack was inferior when no hydrocarbon compound was blended or when a small amount was blended (Comparative Examples 1 and 3).
Moreover, when dry oil (paulownia oil) was mix | blended instead of the hydrocarbon-type compound, although surface tack was improved, it turned out that it is inferior to a weather resistance (comparative example 2).
Further, it was found that when a large amount of a hydrocarbon compound was blended, the wax precipitated on the surface of the cured product and could not be used practically (Comparative Example 4).
Moreover, when the urethane prepolymer which does not have a polysulfide frame | skeleton was mix | blended, it turned out that surface tack is inferior and adhesiveness falls (comparative example 5).
On the other hand, it was found that all of the curable resin compositions prepared by blending a specific amount of the hydrocarbon compound (B) had no surface tack after curing and excellent surface weather resistance (implementation). Examples 1-10).
Furthermore, from the comparison between Example 1 and Example 10, it was found that by adding the oxazolidine compound (C), foaming was suppressed and adhesion was improved.

Claims (7)

A curable resin composition containing a urethane prepolymer (A) and a hydrocarbon compound (B),
The urethane prepolymer (A) is a urethane prepolymer obtained by reacting a polyisocyanate compound (a3) with a mixture of a hydroxyl group-containing polysulfide polymer (a1) having a hydroxyl group and a polyoxyalkylene polyol (a2). Yes,
The hydrocarbon compound (B) is at least one selected from the group consisting of chain saturated hydrocarbons, polyolefin compounds, and ester compounds not containing an aromatic ring, and has a melting point of 40 to 160 ° C. And the iodine value is 14 or less,
Curable resin composition whose content of the said hydrocarbon type compound (B) is 0.1-10 mass parts with respect to 100 mass parts of said urethane prepolymers (A).   The curable resin composition according to claim 1, wherein the polyolefin compound is a wax having a viscosity average molecular weight of 800 to 8000 and a melting point of 90 to 120 ° C.   The curable resin composition according to claim 1, wherein the chain saturated hydrocarbon has 20 to 40 carbon atoms and a melting point of 42 to 70 ° C. The curable resin composition according to claim 1, wherein the ester compound is represented by the following formula (I) and has a melting point of 75 to 100 ° C.
R ¹ —COO—R ² (I)
(R ¹ represents a monovalent hydrocarbon group having 25 to 35 carbon atoms, and R ² represents a monovalent hydrocarbon group having 25 to 35 carbon atoms.)   The curable resin composition according to claim 1, wherein the ester compound is carnauba wax.   The curable resin composition according to claim 1, wherein the polyolefin compound is polyethylene.   Furthermore, the curable resin composition in any one of Claims 1-6 containing an oxazolidine compound (C).