JP3144852B2 - Curable resin and composition containing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a curable resin having a main chain substantially consisting of an aliphatic polyester chain and having a hydrolyzable silyl group at a terminal, and a composition containing the same.

In particular, the present invention provides a low-viscosity curable resin having good flexibility, solvent resistance, acid rain resistance, and scratch resistance, and a composition containing the same, and includes paints, adhesives, and sealings. As a base resin such as an agent and a potting agent, or blended with cellulose such as nitrocellulose or cellulose acetate butyrate, epoxy resin, polyester, alkyd, acrylic polyol, and a hydrolyzable silyl group-containing vinyl resin (for example,
54-36395).

[0003]

2. Description of the Related Art In the field where a curable resin is used in the form of a solution, especially in the field of paint, a high solid coating material that can comply with the emission regulations of solvents as seen in the US VOC regulations. The emergence of is desired.

On the other hand, the quality requirements of the market for topcoat paints are also high, especially for automotive paints, due to the user's desire for higher quality, improved scratch resistance, which does not cause scratches in car wash machines, and environmental problems. There is a demand for improved acid rain resistance.

However, although melamine-based paints generally used at present are generally made to have a high solidity, if the blending ratio of a low-viscosity melamine resin component is increased in order to achieve a high solidity, for example, the acid resistance and the resistance to melamine resin are increased. There is a problem that the abrasion resistance is further reduced, and that even in the regular solid type, the acid resistance and the abrasion resistance are not always at a satisfactory level.

[0006]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to solve the above-mentioned problems, and as a result, have found that a curable resin having an aliphatic polyester chain as a main chain and having a hydrolyzable silyl group at a terminal. However, the present invention was found to have low viscosity, and that the cured product had excellent scratch resistance, flexibility, solvent resistance, and acid rain resistance.

That is, the present invention relates to (i) an aliphatic polyester resin (A) having an acryloyl group and an alcoholic hydroxyl group at one molecular end in one molecule, and (ii) a general formula (I):

[0008]

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Wherein R ¹ is selected from the group consisting of alkylene groups having 1 to 10 carbon atoms, arylene groups and aralkylene groups.
A monovalent hydrocarbon group, R ² is an alkyl group having 1 to 10 carbon atoms, X
¹ is a hydrolyzable group, m is an integer of 1 to 3), and (iii) a general formula (II):

[0010]

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(Wherein R ³ is selected from an alkylene group having 1 to 10 carbon atoms, an arylene group and an aralkylene group)
A monovalent hydrocarbon group, R ⁴ is an alkyl group having 1 to 10 carbon atoms, X
² is a hydrolyzable group, n is an integer of 1 to 3), and (iv) a general formula (III):

[0012]

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(Wherein R ⁵ is a monovalent hydrocarbon group selected from an alkyl group having 1 to 25 carbon atoms, an aryl group and an aralkyl group, (CH ₃ O) ₃ Si— (CH ₂ ) ₃ — or ( _{C 2 H 5 O) 3 Si-} (CH 2) 3 - monofunctional organic isocyanate compound represented by the illustrated) (D-1) and (or) a polyfunctional organic isocyanate compound (D-2)
And a curable resin having a number average molecular weight of 600 to 6000, having at least two hydrolyzable silyl groups in one molecule, and a general formula (IV):

[0014]

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(Wherein R ⁶ and R ⁷ are a hydrogen atom or a monovalent hydrocarbon group selected from alkyl, aryl and aralkyl groups having 1 to 10 carbon atoms, Y is a halogen atom, an alkoxy group, an acyloxy group) , An aminoxy group, a phenoxy group, a thioalkoxy group and an amino group, at least one of which is an alkoxy group or a phenoxy group, and a represents an integer of 1 to 3). A composition comprising at least one silyl group-containing vinyl copolymer and the curable resin.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the present invention, an aliphatic polyester resin having an acryloyl group and an alcoholic hydroxyl group in one molecule.
(A) and the isocyanatosilane compound (B) are reacted.

The aliphatic polyester resin (A) has an acryloyl group and an alcoholic hydroxyl group in one molecule at the molecular terminal, and has a number average molecular weight of 200 to 5,000,
300-3000 aliphatic polyester resins are preferred, and there is no particular limitation as long as they are such.

Specific examples of the polyester chain of the aliphatic polyester resin (A) include polyethylene adipate,
Examples thereof include polyesters or copolyesters such as polydiethylene adipate, polypropylene adipate, polytetramethylene adipate, polyneopentylene adipate, polymethylpentanediol adipate, poly-ε-caprolactone, and polymethylvalerolactone, and polyhexamethylene carbonate.

Among them, poly-ε-caprolactone and polymethyl valerolactone are preferable in terms of weather resistance, and polymethyl valerolactone is preferable in terms of good acid rain resistance.

Specific examples of the fatty acid polyester resin (A) include, for example, poly-ε-caprolactone acrylate such as Praxel FA-1, Praxel FA-2, Praxel FA-3, Praxel FA-4, Praxel FA-8 (above) And Daicel Chemical Industries, Ltd.) and polymethyl valerolactone acrylate (Kuraray Co., Ltd.).

The isocyanato silane compound (B) has the general formula (I):

[0022]

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Is a compound represented by the formula:

In the formula, R ¹ is a divalent hydrocarbon group having 1 to 10 carbon atoms. Specifically, in addition to a linear or branched alkylene group, a cyclohexylene group or the like has 6 to 10 carbon atoms. Including a cycloalkylene group, an alkylene group having 1 to 10 carbon atoms such as a trimethylene group and a hexamethylene group, an arylene group having 6 to 10 carbon atoms such as a phenylene group, or an aralkylene group having 7 to 10 carbon atoms such as a xylylene group. Yes, R
² is an alkyl group having 1 to 10 carbon atoms such as a methyl group and an ethyl group.

X ¹ is a hydrolyzable group. Specific examples of the hydrolyzable group include a halogen atom, an alkoxy group such as a methoxy group, an ethoxy group and a butoxy group, an acyloxy group such as an acetoxy group, an aminooxy group, And a group selected from a phenoxy group, a thioalkoxy group and an amino group. Among them, an alkoxy group and an acyloxy group are preferable in terms of stability and odor. m is an integer of 1 to 3.

Specific examples of the isocyanatosilane compound (B) include, for example, 3-isocyanatopropyltrimethoxysilane, 3-isocyanatopropyltriethoxysilane, and 3-isocyanatopropylmethyldimethoxysilane.

The reaction between the aliphatic polyester resin (A) and the isocyanate silane compound (B) is carried out by reacting the isocyanate silane compound (B) 0.3 to 1.0 with respect to 1 mol of the alcoholic hydroxyl group contained in the aliphatic polyester resin (A). It is preferably carried out in a molar ratio, more preferably in a ratio of 0.6 to 1.0 mol. If the proportion of the isocyanate silane compound (B) is less than 0.3 mol, unreacted alcoholic hydroxyl groups tend to increase and storage stability tends to decrease.If the proportion exceeds 1.0 mol, the unreacted isocyanate silane compound (B) Tend to remain, which is not preferred.

The above reaction can be carried out, for example, at a temperature of from room temperature to 200 ° C. for 0.5 to 5 hours under substantially anhydrous conditions, and the reaction proceeds easily under these conditions.

In the above reaction, an organotin catalyst such as dibutyltin laurate and tin octylate can be used as a catalyst.

In order to suppress the radical polymerization of the acryloyl group of the aliphatic polyester resin (A) during the reaction, it is necessary to add a polymerization inhibitor such as hydroquinone, hydroquinone monomethyl ether and BHT before the reaction. preferable.

Thus, the hydroxyl group of the component (A) is
A product in which the isocyanate group of the component (B) forms a urethane bond is obtained (urethanization).

Then, the general formula (II):

[0033]

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The amino group of the aminosilane compound (C) is reacted with the acryloyl group of the reaction product obtained by the above reaction.

In the general formula (II), R ³ is a divalent hydrocarbon group having 1 to 10 carbon atoms, specifically, a linear or branched alkylene group or a cyclohexylene group. 6
C10-C10 alkylene group such as trimethylene group, hexamethylene group, C6-C10 arylene group such as phenylene group, or C7-C10 such as xylylene group containing An aralkylene group, and R ⁴ is an alkyl group having 1 to 10 carbon atoms such as a methyl group and an ethyl group.

X ² is the same hydrolyzable group as X ¹ in formula (I), and n is an integer of 1 to 3.

Specific examples of the aminosilane compound (C) include, for example, 3-aminopropyltrimethoxysilane,
Examples include aminosilane compounds such as 3-aminopropyltriethoxysilane and 3-aminopropylmethyldimethoxysilane.

In the above reaction, the aminosilane compound (C) is used in an amount of 0.7 to 1 mol per acryloyl group contained in the reaction product.
It is preferably carried out at a rate of 1.0 mole, more preferably 0.8 to 1.0 mole.

When the proportion of the aminosilane compound (C) is less than 0.7 mol, unreacted acryloyl groups tend to remain, and the curability of the curable resin tends to decrease. When the proportion exceeds 1.0 mol, unreacted aminosilane tends to remain. Is not preferred.

The reaction is carried out, for example, at a temperature of 10 to 100 ° C.
This is performed for 0.5 to 2 hours.

In the above reaction, 5 to 90 mol% of the aminosilane compound (C) can be replaced by a mercaptosilane compound such as γ-mercaptopropyltrimethoxysilane.

Thus, an aminosilane-modified resin in which the acryloyl group of the component (A) is added to the amino group of the component (C) is obtained.

Then, the amino group of the aminosilane-modified resin, which is the reaction product obtained as described above, and the monofunctional organic isocyanate compound (D-1) and / or the polyfunctional organic isocyanate compound (D-2) ) Is reacted.

The monofunctional organic isocyanate compound (D-
1) has the general formula (III):

[0045]

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Is a compound represented by the formula:

In the general formula (III), R ⁵ is a hexyl group, an octyl group, a dodecyl group, a stearyl group containing a C ⁶ to C 25 cycloalkyl group such as a cyclohexyl group in addition to a linear or branched alkyl group. An alkyl group having 1 to 25 carbon atoms such as a group, an aryl group having 6 to 25 carbon atoms such as a phenyl group, an aralkyl group having 6 to 25 carbon atoms such as a benzyl group, (CH ₃ O) ₃ Si— (CH ₂ ) ₃ - or _{(C 2 H 5 O) 3} Si- (CH 2) 3 - it is.

The monofunctional organic isocyanate compound (D-
Specific examples of 1) include, for example, n-butyl isocyanate, n-dodecyl isocyanate, stearyl isocyanate, cyclohexyl isocyanate, phenyl isocyanate, benzyl isocyanate, 3-isocyanatopropyltrimethoxysilane, 3-isocyanate Propyltriethoxysilane, 3-isocyanatopropylmethyldimethoxysilane and the like.

The polyfunctional organic isocyanate compound (D-
2) is not particularly limited as long as it has two or more isocyanate groups in one molecule, but preferably has two or three isocyanate groups in one molecule.
Specific examples thereof include, for example, hexamethylene diisocyanate, isophorone diisocyanate, 2,4-toluylene diisocyanate, diphenylmethane-4,4′-diisocyanate, dicyclohexylmethane-4,4′-diisocyanate, Xylylene diisocyanate, lysine methyl ester diisocyanate,

[0050]

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A trimer of isophorone diisocyanate (isocyanurate) is exemplified.

When the obtained curable resin among the isocyanate compounds is used for the exterior, an aliphatic isocyanate or an alicyclic isocyanate is more preferable than an aromatic isocyanate in terms of weathering yellowing. .

When a hydrolyzable silyl group-containing monofunctional isocyanate compound such as 3-isocyanatopropyltrimethoxysilane is used as the component (D-1), one more hydrolyzable silyl group can be introduced. By using a polyfunctional organic isocyanate compound such as a bifunctional isocyanate as the component (D-2), two aminosilane-modified resins can be bonded. Therefore, the monofunctional organic isocyanate compound (D-1)
The polyfunctional organic isocyanate compound (D-2) can be used alone or in combination of two or more depending on the purpose.

In the above reaction, the isocyanate compound is preferably 0.7 to 1.0 g equivalent, more preferably 0.1 g to the active hydrogen of the amino group contained in the aminosilane-modified resin.
It is carried out at a rate of 8 to 1 g equivalent. If the ratio of the isocyanate compound is less than 0.7 g equivalent, storage stability (thickening due to moisture) and yellowing resistance tend to decrease, and
If it exceeds g equivalent, the free isocyanate tends to remain, which is not preferable.

The above-mentioned reaction is carried out under substantially anhydrous conditions. For example, the above-mentioned isocyanate compound (D-1) and / or (D-2) is added to an aminosilane-modified resin or a solution thereof.
Simply proceeds at a temperature of from room temperature to 60 ° C., and proceeds easily with heat generation.

As described above, the curable resin of the present invention is produced by a series of addition reactions (urethane formation → Michael addition → urea formation), and there is no need to remove elimination products, and the amount of reactants and The desired curable resin can be easily obtained by controlling the temperature.

In the above reaction, a solvent may not be used, but a solvent may be used to control the temperature and viscosity of the reaction.

Examples of the solvent include those having no active hydrogen, for example, heptane, toluene, xylene, butyl acetate, methyl ethyl ketone and the like. In particular, when water is contained in the raw material, the water can be removed in advance by azeotropic dehydration using heptane or toluene.

The curable resin thus obtained has at least one, preferably 1 to 3, aliphatic polyester chains.
Urethane bonds, at least one, preferably 1-3
Has three trisubstituted urea bonds in the skeleton and has a hydrolyzable silyl group at the terminal.

The number average molecular weight of the curable resin is 600
~ 6000, preferably 700-4000. Number average molecular weight is
If it is less than 600, the flexibility decreases, and if it exceeds 6000, the acid resistance and the scratch resistance decrease.

One molecule of the curable resin contains at least 2, preferably 2 to 6, more preferably 2 to 4 hydrolyzable silyl groups.

The curable resin of the present invention has excellent flexibility due to an aliphatic polyester chain, and has a urethane bond and N,
Excellent solvent resistance due to N, N'-3 substituted urea bond,
Despite having a bond with high cohesion, it has the basic characteristics of low resin viscosity and good compatibility with other resins. Therefore, the curable resin of the present invention is most useful as a high solid top coat for automobiles.

Further, acid rain resistance and abrasion resistance, for which quality improvement in this application has been desired in recent years, are remarkably superior to acrylic melamine paints generally used at present.

It is considered that the cured product of the curable resin of the present invention having excellent acid rain resistance is not due to ether crosslinking as in acrylic melamine paint but to siloxane crosslinking having high chemical resistance. Although the cause of the appearance of the scratch resistance is not well understood, it is considered that the skeleton of the curable resin of the present invention has good elastic recovery.

The composition of the present invention has the general formula (IV):

[0066]

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And a curable resin comprising a silyl group-containing vinyl copolymer having at least one, preferably 2 to 10 silyl groups per molecule.

In the general formula (IV), R ⁶ and R ⁷ may be the same or different and each represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms such as a methyl group or an ethyl group, a phenyl group or the like. It is a monovalent hydrocarbon group selected from an aralkyl group such as an aryl group and a benzyl group.

Y is a group selected from a halogen atom, an alkoxy group such as a methoxy group, an ethoxy group and a butoxy group, an acyloxy group such as an acetoxy group, a thioalkoxy group such as an aminooxy group and a phenoxy group, and an amino group. At least one is an alkoxy group or a phenoxy group.

A represents an integer of 1 to 3.

The vinyl monomer is not particularly limited. Examples thereof include methacrylic monomers such as methyl methacrylate, n-butyl methacrylate and isobutyl methacrylate; acrylic monomers such as n-butyl acrylate and 2-ethylhexyl acrylate; and γ-trimethoxysilyl. Hydrolyzable silyl group-containing vinyl monomers such as propyl methacrylate, styrene, acrylamide and the like are used.

As a method for synthesizing the vinyl polymer, for example, a method disclosed in JP-A-54-36395 may be used.

In the composition, 5 to 95 parts (parts by weight, hereinafter the same) of the vinyl copolymer, preferably 10 to 70 parts
Parts and 95 to 5 parts, and preferably 90 to 30 parts, of the curable resin so that the total amount is 100 parts.

When the proportion of the vinyl copolymer is less than 5 parts, the effect of improving the acid resistance tends to decrease, and when it exceeds 95 parts, the effect of improving the scratch resistance tends to decrease.

The acid rain resistance and the hardness can be increased by blending with a silyl group-containing vinyl resin.
In addition, blends with other resins and paints are also possible, such as epoxy resins, polyester alkyds,
By blending with resins such as acrylic polyol,
Flexibility and solvent resistance can be improved, and acid rain resistance and scratch resistance can be improved by blending with melamine alkyd paint and melamine acrylic paint.

The amount of the other components that can be added to the composition is preferably 50 parts or less based on 100 parts of the resin solids in the composition from the viewpoint of the physical properties characteristic of the present invention.

The composition of the present invention further comprises a known solvent,
A dehydrating agent, an antioxidant, a leveling agent, and a pigment can be blended.

The curable resin of the present invention or a composition containing the same can be cured using a known curing catalyst. Specific examples of the curing catalyst include, for example, organic tin compounds such as dibutyltin laurate and tin octylate; acidic compounds such as paratoluenesulfonic acid and acidic phosphate; ethylenediamine, isophoronediamine, N, N-dimethyldodecylamine and the like. Amine compounds and the like.

From the viewpoint of curability, these curing catalysts are used in an amount of 0.005 to 10 parts, preferably 0.1 to 10 parts, per 100 parts of the curable resin.
It is preferably from 8 to 8 parts. Although the curing of the curable resin of the present invention proceeds rapidly at normal temperature, it can be cured in a shorter time by heating to 80 to 160 ° C.

The composition of the present invention is excellent in acid resistance, scratch resistance, flexibility and weather resistance, and can be suitably used as a coating material for exterior use.

Hereinafter, the present invention will be described specifically with reference to examples.

Production Example 1 (Synthesis of Hydrolyzable Silyl Group-Containing Acrylic Copolymer) A reactor equipped with a stirrer, a thermometer, a nitrogen inlet tube and a cooling tube was charged with 200 g of Solvesso 100 and heated to 110 ° C. Warmed. Then, a mixture of 177 g of n-butyl methacrylate, 177 g of methyl methacrylate, 240 g of trimethoxysilylpropyl methacrylate, 6 g of acrylamide, 32 g of azobisisobutyronitrile and 64 g of xylene was stirred under a nitrogen atmosphere for 5 hours. Was added continuously. Thereafter, a solution of 4 g of azobisisobutyronitrile and 40 g of xylene was continuously added over 2 hours.
After an hour, polymerization was carried out.

Then, the solution was diluted with xylene so that the solid content concentration became 60%, to obtain a solution of the hydrolyzable silyl group-containing acrylic copolymer (1). The obtained hydrolyzable silyl group-containing acrylic copolymer (1) has a number average molecular weight of 3000 and solution viscosity.
200 cps (23 ° C.).

Example 1 Plaxel FA-3 (polycaprolactone acrylate, number average molecular weight: 458, manufactured by Daicel Chemical Industries, Ltd.) was placed in a reactor equipped with a stirrer, a thermometer, a nitrogen inlet tube and a cooling tube.
284 g, 3-isocyanatopropyltrimethoxysilane
127 g and 200 g of xylene were charged and stirred, and reacted at 100 ° C. for 2 hours in a nitrogen atmosphere. After the reaction,
An infrared absorption spectrum analysis of (i) showed that 2270
and the complete disappearance of absorption of NCO of cm ^-1, the generation of urethane bonds of 1540cm ^-1 were observed. The absorption of the acryloyl group at 1630 to 1640 cm ^-1 remained. FIG. 1 shows a chart of an infrared absorption spectrum of the product (i).

Then, after lowering the reaction temperature to 30 ° C., 116 g of 3-aminopropyltrimethoxysilane was added, and the mixture was reacted for 1 hour. Then, the reaction was continued at 60 ° C. for 30 minutes. The infrared absorption spectrum of the reaction solution was analyzed to find that 1630
The absorption of the acryloyl group at 11640 cm ⁻¹ had disappeared. FIG. 2 shows a chart of an infrared absorption spectrum of the product (ii).

After the reaction temperature was lowered to 30 ° C., 73 g of cyclohexyl isocyanate was gradually added with a dropping funnel, and after the completion of the dropping, the reaction was carried out at 60 ° C. for 30 minutes. After the reaction,
The mixture was diluted with xylene so that the solid content concentration became 60% to obtain a curable resin (1) solution. An infrared absorption spectrum of the obtained curable resin (1) was analyzed. As a result, an infrared absorption of 1640 cm ^-1 derived from a urea bond was formed, and a number average molecular weight by GPC method was 1,000. FIG. 3 shows a chart of the infrared absorption spectrum of the obtained curable resin.

Then, dibutyltin dilaurate was added to 100 parts of the obtained curable resin solution (solid content: 60%).
0.5 part was added and diluted with Solvesso 100 to the coating viscosity to obtain a clear paint.

After spray-coating melamine acrylic black enamel on a 30 cm × 10 cm × 0.08 mm electrodeposited intermediate coating plate to a dry film thickness of 10 to 15 μm, leave the setting for 1 minute to dry the clear paint. Spray coating was performed to a film thickness of 40 to 50 μm. After setting for 5 minutes, baking was carried out at 140 ° C. for 30 minutes, and after standing at room temperature for 1 day, the physical properties of the coating film were evaluated as shown below. The results are shown in Table 1.

(Solution Viscosity) The viscosity of a curable resin solution having a solid content of 60% was measured at 23 ° C. using a B-type viscometer.

(Pencil hardness) Evaluated according to JIS K-5400.

(Acid Resistance) After the test piece was immersed in 1% sulfuric acid for 24 hours, the retention (%) of the 20 ° gloss before the immersion was determined. The higher the retention rate, the better the acid resistance.

(Scratch resistance) A test piece was fixed horizontally,
Abrasive material (JIS 8 class loam ± 1.2%, JIS 11 class loam ± 1.2%, kaolin 0.6%, neutral detergent 1.0%, water on test plate
After application of a 96.0% mixture, a weight (contact surface diameter 5 cm, load 22 g / cm ² ) covered with kraft paper is stroked on the coating surface. The lightness after 0, 12, and 100 strokes is measured with a color difference meter, and the difference in the lightness (ΔL) is used to evaluate the scratch resistance. The smaller ΔL indicates better scratch resistance.

(Bending mandrel) 30cm × 10cm × 0.08
Evaluate the crack length in cm after bending a mm-sized painted test piece (a curable resin or composition coated on a soft steel plate to a dry film thickness of 50μ) with an Erichsen mandrel tester. .

Example 2 The reaction was carried out in the same manner as in Example 1 except that 49 g of hexamethylene diisocyanate was used instead of 73 g of cyclohexyl isocyanate, to obtain a curable resin (2) solution having a solid content of 60%. An infrared absorption spectrum analysis of the obtained curable resin (2) revealed that the infrared absorption
1640 cm ⁻¹ was formed, and the number average molecular weight determined by the GPC method was 1500.

Next, a coating film was formed in the same manner as in Example 1, and the physical properties of the coating film were evaluated. The results are shown in Table 1.

Example 3 Instead of 73 g of cyclohexyl isocyanate, tri (6-
The reaction was carried out in the same manner as in Example 1 except that 98 g of isocyanate hexyl) isocyanurate was used.
The curable resin (3) was obtained. An infrared absorption spectrum of the obtained curable resin (3) was analyzed.As a result, an infrared absorption spectrum 1640 cm ^-1 derived from a urea bond was generated, and the number average molecular weight by GPC was 3,000. .

Subsequently, a coating film was formed in the same manner as in Example 1, and the physical properties of the coating film were evaluated. The results are shown in Table 1.

Example 4 407.2 g of polymethylvalerolactone acrylate (manufactured by Kuraray Co., Ltd., number average molecular weight: 1080), 407.2 g, 3-
77.3 g of isocyanatopropyltrimethoxysilane and 200 g of xylene were charged, and the mixture was stirred at 100 ° C. under a nitrogen atmosphere.
For 2 hours. Was subjected to infrared absorption spectrum analysis of the reaction solution, and the complete disappearance of the absorption of NCO in 2270 cm ^-1, the production of the urethane bonds of 1540 cm ^-1 were observed. Also
The absorption of the acryloyl group at 1630 to 1640 cm ^-1 remained.

Then, after lowering the reaction temperature to 30 ° C., 70.9 g of 3-aminopropyltrimethoxysilane was added, and the mixture was reacted for 1 hour. Then, the reaction was further continued at 60 ° C. for 30 minutes. When the infrared absorption spectrum analysis of the reaction solution was performed,
The absorption of the acryloyl group at 1640 cm ^-1 had disappeared.

Then, after lowering the reaction temperature to 30 ° C., 44.6 g of cyclohexyl isocyanate was gradually added with a dropping funnel, and after the completion of dropping, the reaction was carried out at 60 ° C. for 30 minutes. After the reaction is completed, dilute with xylene to a solid concentration of 60%,
A curable resin 4 was obtained.

The obtained curable resin (4) was analyzed for infrared absorption spectrum. As a result, it was found that infrared absorption of 1640 cm ^-1 derived from a urea bond was formed, and the number average molecular weight by GPC was 1600. there were.

Then, a coating film was formed in the same manner as in Example 1, and the physical properties of the coating film were evaluated. The results are shown in Table 1.

Comparative Example 1 A commercially available melamine acrylic clear paint was used in Example 1.
A coating film was formed in the same manner as described above, and the coated film was evaluated. Table 1 shows the results.

Examples 5 to 7 and Comparative Example 2 The curable resin (1) solution and the hydrolyzable silyl group-containing acrylic copolymer (1) solution were mixed in the proportions shown in Table 2 to give Examples 1 to 7. Coating and evaluation were performed in the same manner as in No. 4. Table 2 shows the results.

[0105]

[Table 1]

[0106]

[Table 2]

[0107]

The curable resin of the present invention and the composition containing the same are excellent in acid resistance, scratch resistance, flexibility and solvent resistance.

[Brief description of the drawings]

FIG. 1 shows a chart of an infrared absorption spectrum of a product (i) obtained in Example 1.

FIG. 2 shows a chart of an infrared absorption spectrum of the product (ii) obtained in Example 1.

FIG. 3 shows a chart of an infrared absorption spectrum of the curable resin obtained in Example 1.

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Yoshihiko Okimura 2-63 Kounama-cho, Takasago-cho, Takasago-shi, Hyogo Pref. Dormitory (72) Inventor Hisao Furukawa 4--7-5, Chikushigaoka, Kita-ku, Kobe, Hyogo (56) Reference Reference JP-A-63-156805 (JP, A) JP-A-3-203952 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C08G 18/00-18/87 C08G 63 / 695

Claims (6)

(57) [Claims] (I) an aliphatic polyester resin (A) having an acryloyl group and an alcoholic hydroxyl group in one molecule at the molecular terminal; and (ii) a general formula (I): (Wherein, R ¹ is a divalent hydrocarbon group selected from an alkylene group having 1 to 10 carbon atoms, an arylene group and an aralkylene group, R ² is an alkyl group having 1 to 10 carbon atoms, and X ¹ is a hydrolyzable group. , M represents an integer of 1 to 3) and an isocyanate silane compound (B) represented by the following general formula (II): (Wherein, R ³ is a divalent hydrocarbon group selected from an alkylene group having 1 to 10 carbon atoms, an arylene group and an aralkylene group, R ⁴ is an alkyl group having 1 to 10 carbon atoms, and X ² is a hydrolyzable group. , N represents an integer of 1 to 3), and (iv) a compound represented by the following general formula (III): (Wherein, R ⁵ is a monovalent hydrocarbon group selected from an alkyl group having 1 to 25 carbon atoms, an aryl group and an aralkyl group;
Monofunctional organic isocyanate compounds (D-1) represented by (CH ₃ O) ₃ Si— (CH ₂ ) ₃ — or (C ₂ H ₅ O) ₃ Si— (CH ₂ ) ₃ — Or) polyfunctional organic isocyanate compound (D-2)
A curable resin having a number average molecular weight of 600 to 6000 and having at least two hydrolyzable silyl groups per molecule. 2. The curable resin according to claim 1, wherein the main chain of the curable resin is mainly polycaprolactone. 3. The curable resin according to claim 1, wherein the main chain of the curable resin is mainly polyvalerolactone. 4. The formula in the isocyanate silane compound (B): (Wherein R ² is an alkyl group having 1 to 10 carbon atoms, X ¹ is a hydrolyzable group, m is an integer of 1 to 3) and / or an aminosilane compound (C) : The group represented by the formula (1) wherein R ⁴ is an alkyl group having 1 to 10 carbon atoms, X ² is a hydrolyzable group, and n is an integer of 1 to 3) is a trimethoxysilyl group. Curable resin. 5. The formula in the isocyanate silane compound (B): (Wherein R ² is an alkyl group having 1 to 10 carbon atoms, X ¹ is a hydrolyzable group, m is an integer of 1 to 3) and / or an aminosilane compound (C) : The group represented by the formula (1), wherein R ⁴ is an alkyl group having 1 to 10 carbon atoms, X ² is a hydrolyzable group, and n is an integer of 1 to 3, which is a methyldimethoxysilyl group. Curable resin. 6. A compound of the general formula (IV): (Wherein, R ⁶ and R ⁷ are a hydrogen atom or a monovalent hydrocarbon group selected from an alkyl group having 1 to 10 carbon atoms, an aryl group and an aralkyl group, Y is a halogen atom, an alkoxy group,
A group selected from an acyloxy group, an aminooxy group, a phenoxy group, a thioalkoxy group and an amino group, at least one of which is an alkoxy group or a phenoxy group,
A composition comprising a silyl group-containing vinyl copolymer having at least one silyl group in one molecule represented by the following formula (1) and a curable resin according to claim 1.