JP5953900B2 - Two-component curable resin composition, coating agent and coating film - Google Patents

Description

  The present invention provides a two-part curable resin composition that provides a cured product excellent in scratch resistance, substrate adhesion, fingerprint wiping property, and blocking resistance by self-healing of scratches, a coating agent containing the resin composition, and The present invention relates to a coating film comprising the coating agent.

  Mobile phone housing, PC housing, plastic products such as audio equipment, electronic material parts such as touch panels and LCD screens, home appliances such as refrigerators, microwave ovens and washing machines, woodworking products such as furniture, golf clubs, tennis rackets, etc. There are many products that require surface scratch resistance, such as sports equipment, architectural interiors such as floors, sinks and doorknobs, and interior and exterior of automobiles.

  As a method for imparting scratch resistance to the surface of these products, a technique for imparting scratch resistance by forming a high-hardness coating film made of a UV curable paint or an EB curable paint on the surface is known. However, since these paints use many monomers having a high functional group concentration, distortion due to curing shrinkage tends to occur, the substrate adhesion is not sufficient, and there is a problem that the coating film is easily peeled off or cracked. It was. Moreover, since such a high-hardness coating film is hard and brittle, the hard coat film obtained by forming this on a plastic film was inferior to secondary processing.

  As another method for imparting scratch resistance to a product surface, a technique for self-healing scratches using a coating film having excellent flexibility and toughness is known. Specifically, a polyester polyol having an average of 2.5 to 3.5 hydroxyl groups per molecule and a number average molecular weight in the range of 500 to 1,500, a polyisocyanate and a tin-based urethanization catalyst. A coating composition as an essential component is known (see Patent Document 1). The coating film composed of such a coating composition has characteristics that are superior in substrate adhesion and secondary processability compared to a high-hardness coating film, and also has scratch resistance due to self-healing. However, since the surface is relatively soft, dirt such as fingerprints is difficult to wipe off, and when the coated film having the coating film is stored in a stacked state, a blocking phenomenon in which the films stick to each other easily occurs. Accordingly, there has been a demand for a coating agent that is excellent in fingerprint wiping property and blocking resistance in addition to scratch resistance.

JP-A 63-86762

  Therefore, the problem to be solved by the present invention is to provide a two-part curable resin composition whose cured coating film has high scratch resistance and substrate adhesion, and is excellent in fingerprint wiping and blocking resistance. It is in.

  As a result of intensive studies to solve the above problems, the present inventors have obtained a polyisocyanate compound having an isocyanate group equivalent in the range of 100 to 280 g / eq, and an average Tg in the range of −55 to −5 ° C., A polyester polyol having an average number of functional groups of hydroxyl groups per molecule in the range of 3.8 to 20 and a number average molecular weight (Mn) in the range of 1,000 to 3,000, and a number average molecular weight (Mn). By using a two-part curable resin composition containing, as an essential component, a polyoxyalkylene glycol having a molecular weight of 2,000 to 15,000, it has high scratch resistance and adhesion to a substrate, and has a fingerprint wiping property. And it discovered that the cured coating film which is excellent also in blocking resistance was obtained, and came to complete this invention.

  That is, the present invention provides a polyisocyanate compound (A) having an isocyanate group equivalent of 100 to 280 g / eq, a glass transition temperature (Tg) of −55 to −5 ° C., and an average of hydroxyl groups per molecule. A polyester polyol (B) having a functional group number of 3.8 to 20 and a number average molecular weight (Mn) in the range of 1,000 to 3,000, and a number average molecular weight (Mn) of 2,000 to 15, The present invention relates to a two-part curable resin composition comprising polyoxyalkylene glycol (C) in the range of 000 as an essential component.

  The present invention further relates to a coating agent containing the two-part curable resin composition.

  The present invention further relates to a coating film obtained by curing the coating agent.

  According to the present invention, compared to conventional coating agents, the coating agent has high scratch resistance and substrate adhesion, and is excellent in fingerprint wiping and blocking resistance. A mold resin product and a cured coating film thereof can be provided.

  The polyisocyanate compound (A) used in the present invention has an isocyanate group equivalent in the range of 100 to 280 g / eq. When the isocyanate group equivalent is less than 100 g / eq, the coating film becomes hard and brittle, and the external force cannot be absorbed, resulting in reduced scratch resistance. When the isocyanate group equivalent exceeds 280 g / eq, the cured coating film becomes too soft and sufficient toughness of the coating film cannot be obtained, so that the scratch resistance is lowered. Among these, the isocyanate group equivalent is more preferably in the range of 150 to 280 g / eq, and still more preferably in the range of 180 to 260 g / eq, in that the scratch resistance of the coating film is further improved.

  Since the average number of functional groups of isocyanate groups per molecule of the polyisocyanate compound (A) is a state where the crosslinking density is suitable, and a balance between toughness and flexibility becomes a highly scratch-resistant coating film, The range is preferably 2 to 5, and more preferably 3 to 5.

  Further, the number average molecular weight (Mn) of the polyisocyanate compound (A) is preferably in the range of 500 to 1,500 because the balance between toughness and flexibility becomes good and the coating film has excellent scratch resistance. More preferably, it is in the range of 700 to 1,000.

In the present invention, the number average molecular weight (Mn) of the polyisocyanate compound (A) is a value measured by gel permeation chromatography (GPC) under the following conditions.
Measuring device: HLC-8220 manufactured by Tosoh Corporation
Column: Guard column H _XL- H manufactured by Tosoh Corporation
+ Tosoh Corporation TSKgel G5000H _XL
+ Tosoh Corporation TSKgel G4000H _XL
+ Tosoh Corporation TSKgel G3000H _XL
+ Tosoh Corporation TSKgel G2000H _XL
Detector: RI (differential refractometer)
Data processing: Tosoh Corporation SC-8010
Measurement conditions: Column temperature 40 ° C
Solvent tetrahydrofuran
Flow rate 1.0 ml / min Standard; polystyrene sample; 0.4% by weight tetrahydrofuran solution in terms of resin solid content filtered through a microfilter (100 μl)

  Examples of the polyisocyanate compound (A) include various diisocyanate monomers, adduct-type polyisocyanate compounds (a1) having a urethane bond site in the molecule, and nurate-type polyisocyanate compounds (a2) having an isocyanurate ring structure in the molecule. Is mentioned.

  Specific examples of the diisocyanate monomer include butane-1,4-diisocyanate, hexamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, 2,4,4-trimethylhexamethylene diisocyanate, xylylene diisocyanate, m- Aliphatic diisocyanates such as tetramethylxylylene diisocyanate;

  Cycloaliphatic diisocyanates such as cyclohexane-1,4-diisocyanate, isophorone diisocyanate, lysine diisocyanate, dicyclohexylmethane-4,4′-diisocyanate, 1,3-bis (isocyanatomethyl) cyclohexane, methylcyclohexane diisocyanate;

  1,5-naphthylene diisocyanate, 4,4'-diphenylmethane diisocyanate, 4,4'-diphenyldimethylmethane diisocyanate, 4,4'-dibenzyl diisocyanate, dialkyldiphenylmethane diisocyanate, tetraalkyldiphenylmethane diisocyanate, 1,3-phenylene diisocyanate And aromatic diisocyanates such as 1,4-phenylene diisocyanate and tolylene diisocyanate.

  Examples of the adduct type polyisocyanate compound (a1) having a urethane bond site in the molecule include those obtained by reacting a diisocyanate monomer with a polyhydric alcohol. Examples of the diisocyanate monomer used as a raw material for the adduct-type polyisocyanate compound (a1) include the various diisocyanate monomers described above, and each may be used alone or in combination of two or more. Among them, the aliphatic diisocyanate or the alicyclic diisocyanate is preferable, the aliphatic diisocyanate is more preferable, and the hexamethylene diisocyanate is particularly preferable because a coating film having excellent balance between toughness and flexibility and high scratch resistance can be obtained. .

  The polyhydric alcohol used as a raw material for the adduct type polyisocyanate compound (a1) is, for example, ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, 1,2,2-trimethyl-1,3-propanediol, 2 , 2-dimethyl-3-isopropyl-1,3-propanediol, 2,2-dimethyl-3-benzyl-1,3-propanediol, 2,2-dimethyl-3-isobutyl-1,3-propanediol, 1,3-butanediol, 1,4-butanediol, 2,2,3,3-tetramethyl-1,4-butanediol, 2,2,4-trimethyl-1,3-pentanediol, 2,2 , 4-Trimethyl-1,5-pentanediol, 1,6-hexanediol, 2,4,4-trimethyl-1 Aliphatic diols such as 1,6-hexanediol and neopentyl glycol;

  Tri- or higher functional aliphatic polyols such as glycerin, trimethylolethane, trimethylolpropane, pentaerythritol, dipentaerythritol;

  Ether glycols such as polyoxyethylene glycol, polyoxypropylene glycol, polyoxytetramethylene glycol;

  The aliphatic diol or aliphatic polyol and succinic acid, adipic acid, azelaic acid, sebacic acid, terephthalic acid, isophthalic acid, orthophthalic acid, tetrahydrophthalic acid, hexahydrophthalic acid, maleic acid, fumaric acid, citraconic acid, itaconic Polyester polyols obtained by cocondensation with acids, glutaconic acids, dicarboxylic acids such as 1,4-cyclohexanedicarboxylic acid;

  A lactone-based polyester polyol obtained by a polycondensation reaction between the aliphatic diol or the aliphatic polyol and various lactones such as ε-caprolactone, δ-valerolactone, and 3-methyl-δ-valerolactone;

  Examples thereof include modified polyether polyols obtained by ring-opening polymerization of the aliphatic diol or aliphatic polyol and cyclic ether compounds such as ethylene oxide, propylene oxide, tetrahydrofuran, ethyl glycidyl ether, and propyl glycidyl ether. These may be used alone or in combination of two or more.

  Among these, since it becomes easy to adjust the isocyanate equivalent of the obtained adduct type polyisocyanate compound (a1) to 100 to 280 g / eq, an aliphatic diol or an aliphatic polyol is preferable, and 1,3-butanediol is preferable. Or trimethylolpropane is more preferable.

  Examples of the nurate type polyisocyanate compound (a2) having an isocyanurate ring structure in the molecule include those obtained by nurating a diisocyanate monomer in the presence of a monoalcohol or a diol. Examples of the diisocyanate monomer used as a raw material for the nurate type polyisocyanate compound (a2) include the various diisocyanate monomers described above, and each may be used alone or in combination of two or more. Especially, since the coating film which is excellent in toughness and a softness | flexibility and has high scratch resistance is obtained, the said aliphatic diisocyanate or alicyclic diisocyanate is preferable, aliphatic diisocyanate is more preferable, and hexamethylene diisocyanate is especially preferable.

  Monoalcohols used as raw materials for the nurate polyisocyanate compound (a2) are hexanol, 2-ethylhexanol, octanol, n-decanol, n-undecanol, n-dodecanol, n-tridecanol, n-tetradecanol, n- Pentadecanol, n-heptadecanol, n-octadecanol, n-nonadecanol, eicosanol, 5-ethyl-2-nonanol, trimethylnonyl alcohol, 2-hexyldecanol, 3,9-diethyl-6-tridecanol, 2- Examples include isoheptylisoundecanol, 2-octyldodecanol, and 2-decyltetradecanol.

  Examples of the diol used as the raw material for the nurate polyisocyanate compound (a2) include various diols exemplified as the raw material for the adduct type polyisocyanate compound (a1). These monoalcohols and diols may be used alone or in combination of two or more.

  Among these monoalcohols and diols, it is easy to adjust the isocyanate group equivalent of the resulting nurate-type polyisocyanate compound (a2) to the above preferred value, so that 1,3-butanediol or 2,2,4 -Trimethyl-1,3-pentanediol is preferred.

  The polyisocyanate compound (A) may be used alone or in combination of two or more. Among these, the adduct type polyisocyanate compound (a1) or the nurate type polyisocyanate compound (a2) is preferable because a good balance between flexibility and toughness is obtained and a scratch-resistant coating film is obtained. A polyisocyanate compound (a2) is more preferred.

  The polyester polyol (B) used in the present invention has a glass transition temperature (Tg) in the range of −55 to −5 ° C., an average number of functional groups of hydroxyl groups per molecule of 3.8 to 20, and The number average molecular weight (Mn) is in the range of 1,000 to 3,000. When these three conditions are met, a cured coating film having an excellent balance between toughness and flexibility and having high scratch resistance and self-healing adhesion can be obtained.

  The polyester polyol (B) has a glass transition temperature (Tg) in the range of −55 ° C. to −5 ° C. When the glass transition temperature (Tg) is less than −55 ° C., the obtained coating film is too soft, so that the scratch resistance is lowered. Moreover, when a glass transition temperature (Tg) exceeds -5 degreeC, since the coating film obtained is too hard, external force cannot be absorbed and scratch resistance falls. Especially, it is more preferable that it is the range of -45 degreeC--15 degreeC at the point which is excellent in the balance of toughness and a softness | flexibility, and the coating film which has high scratch resistance is obtained.

  The average number of functional groups of hydroxyl groups per molecule of the polyester polyol (B) is in the range of 3.8-20. When the average number of functional groups of the hydroxyl group is less than 3.8, the crosslinking density of the cured coating film is lowered and the toughness is lowered, so that sufficient scratch resistance cannot be exhibited. Moreover, when the average functional group number of a hydroxyl group exceeds 20, since the crosslinked density of a cured coating film is too high, it becomes a hard and brittle coating film and cannot absorb external force, and scratch resistance falls. Especially, since it is excellent in scratch resistance and a coating film having high gloss is obtained, it is more preferably in the range of 4 to 15, and particularly preferably in the range of 5 to 10.

  The number average molecular weight (Mn) of the polyester polyol (B) is in the range of 1,000 to 3,000. When the number average molecular weight (Mn) is less than 1,000, the coating film is hard and brittle, and sufficient scratch resistance is not exhibited. Moreover, when a number average molecular weight (Mn) exceeds 3,000, a coating film is too soft and sufficient scratch resistance is not expressed. Among these, the range of 1,200 to 2,500 is preferable in that the balance between flexibility and toughness of the coating film is good and scratch resistance is excellent.

In the present invention, the number average molecular weight (Mn) of the polyester polyol (B) is a value measured by gel permeation chromatography (GPC) under the following conditions.
Measuring device: HLC-8220 manufactured by Tosoh Corporation
Column: Guard column H _XL- H manufactured by Tosoh Corporation
+ Tosoh Corporation TSKgel G5000H _XL
+ Tosoh Corporation TSKgel G4000H _XL
+ Tosoh Corporation TSKgel G3000H _XL
+ Tosoh Corporation TSKgel G2000H _XL
Detector: RI (differential refractometer)
Data processing: Tosoh Corporation SC-8010
Measurement conditions: Column temperature 40 ° C
Solvent tetrahydrofuran
Flow rate 1.0 ml / min Standard; polystyrene sample; 0.4% by weight tetrahydrofuran solution in terms of resin solid content filtered through a microfilter (100 μl)

  The hydroxyl value of the polyester polyol (B) is such that the crosslink density of the cured coating film is a suitable value, the balance between toughness and flexibility is excellent, and a coating film having high scratch resistance and substrate adhesion is obtained. It is preferable that it is the range of 110-250 mgKOH / g.

  Examples of the polyester polyol (B) include those obtained by co-condensing a polyhydric alcohol and a polyvalent carboxylic acid.

  Examples of the polyhydric alcohol that is a raw material for the polyester polyol (B) include ethylene glycol, diethylene glycol, propylene glycol, 1,3-propanediol, 1,2,2-trimethyl-1,3-propanediol, and 2,2. -Dimethyl-3-isopropyl-1,3-propanediol, 1,4-butanediol, 1,3-butanediol, 3-methyl-1,3-butanediol, 1,5-pentanediol, 3-methyl-1 Aliphatic diols such as 1,5-pentanediol, neopentyl glycol, 1,6-hexanediol, 1,4-bis (hydroxymethyl) cyclohesane, 2,2,4-trimethyl-1,3-pentanediol;

  Trifunctional or higher functional aliphatic polyols such as trimethylolethane, trimethylolpropane, glycerin, hexanetriol, pentaerythritol;

  Ether glycols such as polyoxyethylene glycol and polyoxypropylene glycol;

  Ring-opening polymerization of the aliphatic diol or aliphatic polyol with various cyclic ether bond-containing compounds such as ethylene oxide, propylene oxide, tetrahydrofuran, ethyl glycidyl ether, propyl glycidyl ether, butyl glycidyl ether, phenyl glycidyl ether, and allyl glycidyl ether. Modified polyether polyols obtained by:

  A lactone-based polyester polyol obtained by a polycondensation reaction between the aliphatic diol or aliphatic polyol and various lactones such as ε-caprolactone;

  Bisphenols such as bisphenol A and bisphenol F;

  Examples thereof include alkylene oxide adducts of bisphenol obtained by adding ethylene oxide, propylene oxide and the like to bisphenols such as bisphenol A and bisphenol F. These may be used alone or in combination of two or more.

  Among these polyhydric alcohols, the aliphatic diol or the aliphatic polyol is preferable because it is easy to design various property values of the obtained polyester polyol (B) to the above-described preferable values, and ethylene glycol, 1, 3-butanediol, neopentyl glycol, 1,6-hexanediol, glycerin, trimethylolethane, trimethylolpropane, pentaerythritol, and dipentaerythritol are more preferable.

  Examples of the polyvalent carboxylic acid used in the synthesis of the polyester polyol (B) include aliphatic dicarboxylic acids such as malonic acid, succinic acid, glutaric acid, adipic acid, azelaic acid, and sebacic acid;

  Aromatic dicarboxylic acids such as phthalic acid, phthalic anhydride, terephthalic acid, isophthalic acid, orthophthalic acid;

  Alicyclic dicarboxylic acids such as hexahydrophthalic acid and 1,4-cyclohexanedicarboxylic acid;

  Aliphatic unsaturated dicarboxylic acids such as tetrahydrophthalic acid, maleic acid, maleic anhydride, fumaric acid, citraconic acid, itaconic acid, glutaconic acid;

  Various tricarboxylic acids such as 1,2,5-hexanetricarboxylic acid, trimellitic acid, 1,2,5-benzenetricarboxylic acid, 1,2,4-cyclohexanetricarboxylic acid, 2,5,7-naphthalenetricarboxylic acid, etc. Can be mentioned. These may be used alone or in combination of two or more.

  Among these polyvalent carboxylic acids, it is possible to use an aliphatic carboxylic acid and an aromatic carboxylic acid in combination in that it is easy to design various characteristic values of the obtained polyester polyol (B) to the above-described preferable values. Preferably, the aliphatic carboxylic acid is adipic acid and sebacic acid, and the aromatic carboxylic acid is more preferably phthalic acid, phthalic anhydride, terephthalic acid isophthalic acid, and trimellitic acid.

  The reaction raw material for producing the polyester polyol (B) in which the average Tg is in the range of −55 to −5 ° C. and the average number of functional groups of hydroxyl groups per molecule is in the range of 4 to 20 is the polyester polyol obtained. Since it becomes easy to adjust the Tg and average functional group number of (B) to desired values, a raw material containing a trifunctional or higher aliphatic polyol and a dicarboxylic acid, or an aliphatic diol and a trifunctional polycarboxylic acid It is preferable that it is a raw material containing these. Moreover, in the reaction raw material of the polyester polyol (B), the trifunctional or higher functional component such as a trifunctional or higher aliphatic polyol or a trifunctional polycarboxylic acid is within a range of 10 to 40% by mass of the total mass of the reactive raw material. It is preferable to use in. One type of the polyester polyol (B) may be used alone, or a plurality of types synthesized with different compositions may be used in combination.

  In the present invention, a polyoxyalkylene glycol having a number average molecular weight (Mn) in the range of 2,000 to 15,000 in combination with the polyester polyol (B) as a polyol component of the two-component curable resin composition ( By using C), it is possible to obtain a cured coating film that is excellent not only in scratch resistance and adhesion to a substrate but also in fingerprint resistance and blocking resistance.

  The number average molecular weight (Mn) of the polyoxyalkylene glycol (C) is in the range of 2,000 to 15,000. When it is less than 2,000, the blocking resistance and fingerprint wiping property are lowered, and when it is more than 15,000, the scratch resistance of the coating film is lowered. Among them, since a coating film having higher fingerprint wiping resistance and blocking resistance and having an excellent balance with scratch resistance is obtained, the number average molecular weight (Mn) is in the range of 4,000 to 13,000. Some are more preferred, and those in the range of 6,000 to 12,000 are particularly preferred.

  Specific examples of the polyoxyalkylene glycol (C) include polyoxyethylene glycol, polyoxypropylene glycol, polyoxytetramethylene glycol and the like having a single oxyalkylene group as a repeating unit. Examples thereof include those having a plurality of oxyalkylene groups as repeating units, such as oxypropylene glycol. These may be used alone or in combination of two or more. Among these, since a coating film having higher fingerprint resistance and blocking resistance can be obtained, those having a polyoxypropylene structure such as polyoxypropylene glycol and polyoxyethylene polyoxypropylene glycol are preferable. Oxypropylene glycol is more preferred.

  When the two-component curable resin composition of the present invention comprises the polyisocyanate (A), the polyester polyol (B), and the polyoxyalkylene glycol (C), the blending amount of the polyoxyalkylene glycol (C) is: Since a coating film excellent in all of scratch resistance, substrate adhesion, fingerprint wiping property and blocking resistance is obtained, the total amount of the polyisocyanate (A) and the polyester polyol (B) is 100 parts by mass. The ratio of the polyoxyalkylene glycol (C) is preferably in the range of 0.2 to 5 parts by mass, and more preferably in the range of 0.5 to 2.

When the two-component curable resin composition of the present invention comprises the polyisocyanate (A), the polyester polyol (B), and the polyoxyalkylene glycol (C), these blending ratios are resin compositions having excellent curability. Therefore, the number of moles of isocyanate group (N _NCO ) contained in the polyisocyanate (A), the hydroxyl group contained in the polyester polyol (B), and the hydroxyl group contained in the polyoxyalkylene glycol (C) It is preferable that the ratio [(N _NCO ) / (N _OH )] with the sum of the number of moles of (N _OH ) be in the range of 0.75 to 1.5.

  The two-component curable resin composition of the present invention may contain a polyol compound other than the polyester polyol (B) and the polyoxyalkylene glycol (C). Specific examples include polyester polyols having a number average molecular weight (Mn) of less than 1,000 or more than 3,000, polyester polyols having a glass transition temperature (Tg) of more than −5 ° C., and polycarbonate polyols. In the case where these other polyol compounds are used, the polyester polyol (B) and the polyisocyanate are in a range that does not hinder the effects of the present invention excellent in scratch resistance, substrate adhesion, fingerprint resistance and blocking resistance. It is preferable to use in the range of 5-30 mass parts with respect to 100 mass parts of the sum with oxyalkylene glycol (C).

  When the two-component curable resin composition of the present invention contains another polyol compound in addition to the polyisocyanate (A), the polyester polyol (B), and the polyoxyalkylene glycol (C), Since the coating amount which is excellent in all of scratch resistance, substrate adhesion, fingerprint wiping property and blocking resistance is obtained, the blending amount of glycol (C) is based on 100 parts by mass of the nonvolatile content of the resin composition. The ratio of the polyoxyalkylene glycol (C) is preferably in the range of 0.2 to 5 parts by mass, and more preferably in the range of 0.5 to 2.

Moreover, since it becomes a resin composition having excellent curability, the number of moles of isocyanate groups (N _NCO ) contained in the polyisocyanate (A) and the number of moles of hydroxyl groups contained in each polyol compound in the resin composition It is preferable that the ratio [(N _NCO ) / (N _OH )] with the sum (N _OH ) be in the range of 0.75 to 1.5.

  You may add a hardening accelerator to the coating resin composition of this invention as needed. Examples of the curing accelerator include cobalt naphthenate, zinc naphthenate, stannous chloride, stannic chloride, tetra-n-butyltin, tri-n-butyltin acetate, n-butyltin trichloride, trimethyltin hydro Examples of the urethanization catalyst include oxide, dimethyltin dichloride, dibutyltin acetate, dibutyltin dilaurate, and tin octenoate.

  In addition, a lubricant, an antiblocking agent, an ultraviolet absorber, a light stabilizer, an antistatic agent, an antifogging agent, a colorant, and the like are appropriately added to the coating resin composition part of the present invention as long as the effects of the present invention are not impaired. May be.

  Since the coating film comprising the coating resin composition of the present invention described above has both flexibility and toughness, the coating film absorbs external force and is hardly scratched. Excellent self-healing and scratch resistance. Furthermore, it is excellent in adhesion to various materials, secondary workability of an object to be coated, and fingerprint resistance. Therefore, the coating resin composition of the present invention is used for plastic products such as mobile phone casings, personal computer casings, audio equipment, electronic material parts such as touch panels and liquid crystal screens, household appliances such as refrigerators, microwave ovens and washing machines, and furniture. Such as woodwork products such as golf clubs, sports equipment such as tennis rackets, architectural interiors such as floors, sinks and doorknobs, interior and exterior of automobiles, etc. In addition, the coating resin composition of the present invention can be applied in the form of a plastic film / sheet and used as a scratch-resistant laminated film / sheet. The blocking phenomenon that sticks to each other hardly occurs.

  The thickness of the coating film when the coating resin composition of the present invention is applied on various substrates can be appropriately adjusted according to the use, but is preferably 1 μm to 100 μm in terms of expressing higher scratch resistance. 5 μm to 50 μm is more preferable.

  Hereinafter, the present invention will be described in more detail with reference to specific synthesis examples and examples.

Measurement of Number Average Molecular Weight (Mn) In the Examples of the present application, the number average molecular weight (Mn) of each compound was determined using gel permeation chromatography (GPC) under the following conditions.

Measuring device: HLC-8220 manufactured by Tosoh Corporation
Column: Guard column H _XL- H manufactured by Tosoh Corporation
+ Tosoh Corporation TSKgel G5000H _XL
+ Tosoh Corporation TSKgel G4000H _XL
+ Tosoh Corporation TSKgel G3000H _XL
+ Tosoh Corporation TSKgel G2000H _XL
Detector: RI (differential refractometer)
Data processing: Tosoh Corporation SC-8010
Measurement conditions: Column temperature 40 ° C
Solvent tetrahydrofuran
Flow rate 1.0 ml / min Standard; polystyrene sample; 0.4% by weight tetrahydrofuran solution in terms of resin solid content filtered through a microfilter (100 μl)

Measurement of Isocyanate Group Content In the examples of the present application, the isocyanate group content was measured according to JIS K7301.

Calculation of average functional group number per molecule of isocyanate compound (A) In the examples of the present application, the average functional group number per molecule of the isocyanate compound (A) is the isocyanate content and number average molecular weight (Mn) measured by the above method. It calculated from the value of using the following formula.
[Average number of functional groups per molecule] = [Number average molecular weight (Mn)] × [Isocyanate content] / 4,200

Measurement of hydroxyl value In the examples of the present application, the hydroxyl value was measured according to JIS K1557.

Calculation of average number of functional groups per molecule of polyester polyol (B) In the examples of the present application, the average number of functional groups per molecule of polyester polyol (B) is the hydroxyl value and number average molecular weight (Mn) measured by the above method. From the value, it calculated using the following formula.
[Average number of functional groups per molecule] = [Number average molecular weight (Mn)] × [Hydroxyl value] / 56,100

Measurement of Glass Transition Temperature (Tg) In the examples of the present application, the glass transition temperature (Tg) of the polyester polyol (B) is a differential scanning calorimeter (Mettler Co., Ltd.) using a test sample having a solid content of 100% of the polyester polyol (B). The measurement was performed using “TOLEDO DSC822e” manufactured by Kobayashi.

Production Example 1
Production of polyisocyanate compound (A-1) 1,000 parts by mass of hexamethylene diisocyanate was charged into a four-necked flask equipped with a stirrer, thermometer, rectification column, and nitrogen introduction tube, and stirring was started under a nitrogen stream. did. Next, 20 parts by mass of 2,2,4-trimethyl-1,3-pentanediol and 6 parts by mass of 1,3-butanediol were added, and the temperature was raised to 65 ° C. The mixture was reacted at the same temperature for 1 hour, and then 0.1 part by mass of a nurating catalyst (“TOYOCAT TRX” manufactured by Tosoh Corporation) was added and reacted for 15 minutes, and then the refractive index was measured. 0.1 parts by mass of the nurate catalyst was added until the refractive index was 1.4665, and after confirming that the refractive index was 1.4665, phosphoric acid was used as a reaction terminator and the total amount of nurate catalyst added. Of 0.3 parts by mass, which was 1/2 of the above, and stirred for 30 minutes. The internal temperature was raised to 140 ° C., and unreacted hexamethylene diisocyanate was distilled off under reduced pressure at the same temperature. Distillation under reduced pressure at the same temperature is continued until the content of hexamethylene diisocyanate is less than 0.5% by mass with respect to the total mass of the reactants in the flask, to obtain an HDI nurate polyisocyanate compound (A-1). It was. The resulting isocyanate group content of the polyisocyanate compound (A-1) is 21.3% by mass, the isocyanate group equivalent is 200 g / eq, the Gardner viscosity (25 ° C.) is YZ, and the number average molecular weight (Mn) is 720. The average number of functional groups per molecule was 3.7.

Production Example 2
Production of polyisocyanate compound (A-2) 1,000 parts by mass of hexamethylene diisocyanate was charged into a four-necked flask equipped with a stirrer, thermometer, rectification tower, and nitrogen introduction tube, and stirring was started under a nitrogen stream. did. Next, the temperature was raised to 90 ° C., and 90 parts by mass of trimethylolpropane and 16 parts by mass of 1,3-butanediol were dividedly charged over 1 hour while paying attention to heat generation. Furthermore, after reacting at the same temperature for 2 hours, the temperature was raised to 140 ° C., and unreacted hexamethylene diisocyanate was distilled off under reduced pressure at the same temperature. After continuing the vacuum distillation at the same temperature until the hexamethylene diisocyanate content is less than 0.5% with respect to the total mass of the reactants in the flask, the ethyl acetate is adjusted so that the nonvolatile content is 75% by mass. Was added to obtain an ethyl acetate solution of the HDI adduct polyisocyanate compound (A-2). The resulting isocyanate group content of the polyisocyanate compound (A-2) is 16.7% by mass, the isocyanate group equivalent is 251 g / eq, the Gardner viscosity (25 ° C.) is KL, and the number average molecular weight (Mn) is 930. The average number of functional groups per molecule was 3.7.

Production Example 3
Manufacture of polyester polyol (B-1) A 4-necked flask equipped with a stirrer, thermometer, rectifying column, and nitrogen introduction tube was charged with 107 parts by mass of ethylene glycol and 180 parts by mass of neopentyl glycol, under a nitrogen stream. After raising the temperature to 140 ° C., it was confirmed that the inside of the system was uniform, and a mixture consisting of 128 parts by mass of terephthalic acid, 234 parts by mass of sebacic acid, and 101 parts by mass of trimellitic acid was added. The temperature was raised to 230 ° C. over 3 hours, and the reaction was continued at the same temperature until the acid value became 5 or less. Subsequently, after cooling to 140 degreeC, it diluted until the non volatile matter became 75 mass% using butyl acetate, and the solution of the polyester polyol (B-1) was obtained. The number average molecular weight (Mn) of the obtained polyester polyol (B-1) is 2,200, the hydroxyl value is 160 mgKOH / g, the average number of functional groups per molecule is 6.3, and the glass transition temperature (Tg) is −20. ° C.

Production Examples 4-6
Production of polyester polyols (B-2) to (B-4) Polymerization was carried out in the same manner as in Production Example 3 except that the raw materials shown in Table 1 were used instead of the respective raw materials in the above production examples. B-2) to (B-4) solutions were obtained.

Comparative production example 1
Production of polyester polyol (B′-1) Polymerization was carried out in the same manner as in Synthesis Example 3 except that the raw materials shown in Table 1 were used instead of the respective raw materials in Synthesis Example 3, and the nonvolatile content was 80 mass by butyl acetate. % To obtain a polyester polyol (B′-1) solution.

Polyoxyalkylene glycol (C) used in Examples of the present application
Polyoxyalkylene glycol (C-1): polyoxypropylene glycol having a number average molecular weight (Mn) of 10,000 Polyoxyalkylene glycol (C-2): polyoxypropylene glycol polyoxy having a number average molecular weight (Mn) of 7,000 Alkylene glycol (C-3): polyoxypropylene glycol polyoxyalkylene glycol (C-4) having a number average molecular weight (Mn) of 3,000: polyoxytetramethylene glycol polyoxyalkylene having a number average molecular weight (Mn) of 2,000 Glycol (C-5): Polyoxyethylene glycol having a number average molecular weight (Mn) of 3,000

Example 1
Preparation of two-part curable resin composition 84 parts by mass of polyisocyanate (A-1), 200 parts by mass of polyester polyol (B-1), 1.2 parts by mass of polyoxyalkylene glycol (C-1), dibutyltin acetate 0.02 mass part and 30 mass parts of ethyl acetate were mix | blended, and the 2 liquid curable resin composition (1) was obtained. In addition, the number of moles of isocyanate group (N _NCO ) contained in the polyisocyanate (A-1), the hydroxyl group contained in the polyester polyol (B-1), and the hydroxyl group contained in the polyoxyalkylene glycol (C-1) the ratio of the sum of mole number _{(N OH)} of _{[(N NCO) / (N} OH)] is 1.

Preparation of test coating film Using a 3 mil applicator, the two-part curable resin composition (1) is placed on a glass plate and a black acrylonitrile butadiene styrene copolymer resin plate (hereinafter abbreviated as “ABS plate”). Painted on. After setting at room temperature for 15 minutes, it was dried at 80 ° C. for 1 hour, and further cured at 25 ° C. and humidity 50% RH for 1 week.

Evaluation The following two types of evaluation tests were performed on the obtained two types of test coating films. The results are shown in Table 2.

1. Pencil Hardness Test A test coating film coated on a glass plate was evaluated by a pencil scratch test with a load of 500 g according to JIS K 5400. Test 5 times for each hardness, and apply a hardness one level lower than the hardness at which the coating film breaks even once in 5 times, or the pencil mark does not return even when heated with hot air at 70 ° C. The film hardness was used.

2. Pencil Mark Restoration Time The time until the pencil mark having the hardness determined as the coating film hardness was restored in the pencil hardness test was measured and evaluated as follows.
O: No pencil mark A: Restores within 30 minutes after the pencil mark is made.
B: Recover within 30 minutes to 24 hours after the pencil mark.
C: It does not completely recover within 24 hours after the pencil marks, but it recovers when heated with hot air at 70 ° C.

3. Adhesion test A 100 mm grid of 1 mm × 1 mm was prepared with a cutter knife on a test coating film prepared on an ABS plate, and “cello tape” manufactured by Nichiban Co., Ltd. was attached, followed by peeling. At this time, the number of grids in which the coating film adhered without peeling was evaluated.

4). A gloss value of 60 ° specular reflectance [%] of a test coating film prepared on a glossy ABS plate was measured according to JIS-K5400.

5). Abrasion resistance For the test coating film coated on a glass plate, 0.5 g of steel wool (“Bonster # 0000” manufactured by Nippon Steel Wool Co., Ltd.) wrapped with a disc-shaped indenter with a diameter of 2.4 cm is used. A 10-reciprocal wear test was performed under a load of 500 g. The haze value of the test coating film on the glass plate before the abrasion test and the haze value of the test coating film after the abrasion test were measured using an automatic haze computer (“HZ-2” manufactured by Suga Test Instruments Co., Ltd.). The wear resistance was evaluated by the difference between these values. The smaller the value difference, the better the wear resistance.

6). Fingerprint wiping test A fingerprint is attached to a test coating film coated on a glass plate, a tissue paper is placed on the fingerprint trace, and a reciprocation is applied with a load of 1 kg per 5.7 square centimeters, and the attached fingerprint trace is completely visible. Quantitative evaluation was made by the number of round-trips until it disappeared. The smaller the number of reciprocations, the better the wiping of fingerprint marks.
A: Wipe off within 3 times.
○: Wipe off 4-6 times.
X: 7 times or more.

7). Blocking resistance test The test coating film coated on the glass plate was evaluated for stickiness by finger touch. In the preparation of the test coating film, the determination was performed under two conditions: a coating film immediately after drying for 1 hour at 80 ° C. and a coating film after curing for one week under the conditions of 25 ° C. and humidity 50% RH. .
A: There is no stickiness even immediately after drying at 80 ° C. for 1 hour.
○: There is stickiness immediately after drying at 80 ° C. for 1 hour, but there is no stickiness after curing for 1 week.
X: There is stickiness immediately after drying at 80 ° C. for 1 hour and after curing for 1 week.

Examples 2-8
A test coating film was prepared on a glass plate and an ABS plate in the same manner as in Example 1 except that the types and blending ratios of the polyisocyanate (A) and the polyol (B) were changed as shown in Table 2. The above various evaluation tests were conducted. The evaluation results are shown in Table 2.

Comparative Example 1
A test coating film was prepared on a glass plate and an ABS plate in the same manner as in Example 1 except that the types and blending ratios of the polyisocyanate (A) and the polyol (B) were changed as shown in Table 2. The above various evaluation tests were conducted. The evaluation results are shown in Table 2.

Claims (10)

In the range of isocyanate group equivalent is 100~280g / eq, 1 average polyisocyanate compound functional groups is 3 or more isocyanate sulfonate group per molecule (A), a glass transition temperature (Tg) of -55 to-5 ° C. A polyester polyol (B) having an average functional group number of hydroxyl groups per molecule of 3.8 to 20 and a number average molecular weight (Mn) of 1,000 to 3,000, and A two-component curable resin composition comprising polyoxyalkylene glycol (C) having a number average molecular weight (Mn) in the range of 2,000 to 15,000 as an essential component. 2. The polyisocyanate compound (A) is an adduct type polyisocyanate compound (a1) having a urethane bond site in the molecule or a nurate type polyisocyanate compound (a2) having an isocyanurate ring structure in the molecule. The two-component curable resin composition described. The polyisocyanate compound (A) has a number average molecular weight (Mn) of 500 to 1,500. The two-component curable resin composition according to claim 1, which is a wall. Average number of functional groups of isocyanate groups per molecule of the polyisocyanate compound (A) The two-component curable resin composition according to claim 1, wherein is 3 to 5. The two-component curable resin composition according to claim 1, wherein the polyester polyol (B) has a hydroxyl value in the range of 110 to 250 mgKOH / g. The two-component curable resin composition according to claim 1, wherein the polyoxyalkylene glycol (C) is polyoxypropylene glycol. The said polyoxyalkylene glycol (C) is contained in the ratio used as the range which is 0.2-5 mass parts with respect to 100 mass parts of sum of the said polyisocyanate (A) and the said polyester polyol (B). A two-component curable resin composition. Sum of moles of isocyanate groups (N _NCO ) contained in the polyisocyanate (A), and hydroxyl groups contained in the polyester polyol (B) and hydroxyl groups contained in the polyoxyalkylene glycol (C) ( N _OH) and the ratio _{[(N NCO) / (N} OH)] is two-part curable resin composition according to claim 1, wherein in the range of 0.75 to 1.5. A coating agent comprising the two-component curable resin composition according to any one of claims 1 to 8 . A coating film obtained by curing the coating agent according to claim 9 .