ACTIVE ENERGY BEAM-CURABLE RESIN COMPOSITION, RESIN MOLDED ARTICLES, AND METHOD FOR PRODUCING RESIN MOLDED ARTICLES

Abstract

An active energy ray curable resin composition comprising: urethane poly(meth)acrylate (A) synthesized from a raw material including a polyisocyanate and a hydroxy group-containing (meth)acrylate; (meth)acrylate (B) having five or more functional groups; a photopolymerization initiator (C1) having an absorption coefficient per unit weight of 50000 ml/g.Math.cm or more when measured in methanol at 254 nm; a photopolymerization initiator (C2) other than the (C1) having an absorption coefficient per unit weight of 50000 ml/g.Math.cm or more when measured in methanol at 302 nm; a photopolymerization initiator (C3) other than the (C1) and the (C2) having an absorption coefficient per unit weight of 100 ml/g.Math.cm or more when measured in methanol at 405 nm; and an ultraviolet absorbing agent (D).

Claims

1. An active energy ray curable resin composition comprising: urethane poly(meth)acrylate (A) synthesized from a raw material including a polyisocyanate and a hydroxy group-containing (meth)acrylate; (meth)acrylate (B) having five or more functional groups; a photopolymerization initiator (C1) having an absorption coefficient per unit weight of 50000 ml/g.Math.cm or more when measured in methanol at 254 nm; a photopolymerization initiator (C2) other than the (C1) having an absorption coefficient per unit weight of 50000 ml/g.Math.cm or more when measured in methanol at 302 nm; a photopolymerization initiator (C3) other than the (C1) and the (C2) having an absorption coefficient per unit weight of 100 ml/g.Math.cm or more when measured in methanol at 405 nm; and an ultraviolet absorbing agent (D).

2. The active energy ray curable resin composition according to claim 1, wherein, relative to the total amount of a polymerizable component with a vinyl group, the (A) is 0.1% by mass or more and 50% by mass or less, and the (B) is 50% by mass or more and 99.9% by mass or less, and, relative to the total amount of 100 parts by mass of a polymerizable component with a vinyl group, the (C1) is 0.1 part by mass or more and 5 parts by mass or less, the (C2) is 0.1 part by mass or more and 5 parts by mass or less, the (C3) is 0.1 part by mass or more and 5 parts by mass or less, and the (D) is 0.1 part by mass or more and 15 parts by mass or less.

3. The active energy ray curable resin composition according to claim 1, wherein, an ultraviolet absorbing agent (D1) having the maximum absorption wavelength that is in the range of 290 nm or more and 320 nm or less in a region of 290 nm or more and 400 nm or less is contained as the (D).

4. The active energy ray curable resin composition according to claim 1, wherein, a hindered amine light stabilizer (E) is additionally contained.

5. A resin molded article obtained by forming a coating film by applying the active energy ray curable resin composition described in claim 1 on at least part of a surface of the resin molded article and forming a cured coating film by irradiating the obtained coating film with active energy ray for curing.

6. The resin molded article according to claim 5, wherein a film thickness of the cured coating film is 2 m or more and 20 m or less.

7. The resin molded article according to claim 5, wherein the resin molded article obtained by forming the cured coating film is a head lamp lens for an automobile.

8. A method for producing a resin molded article including forming a coating film by applying the active energy ray curable resin composition described in claim 1 on at least part of a surface of the resin molded article and forming a cured coating film by irradiating the obtained coating film with active energy ray for curing.

Description

EXAMPLES

[0102] Hereinbelow, the present invention is described by using the examples. Meanwhile, in the following descriptions, the parts means parts by mass.

[Synthesis Example 1] Synthesis of Urethane Diacrylate (UA1)

[0103] To a flask equipped with a dropping funnel with an incubating function, a reflux condenser, a stirring wing, and a temperature sensor, 2 mol of dicyclohexylmethane-4,4-diisocyanate (manufactured by Sumika Bayer Urethane, trade name: DESMODUR W) and 300 ppm of n-butyl tin dilauric acid (manufactured by ADEKA CORPORATION, trade name: ADK STAB BT-11) were injected and heated to 40 C. In a state in which the dropping funnel with an incubating function is heated to 40 C., 1 mol of polycarbonate diol (number average molecular weight of 800, manufactured by KURARAY CO., LTD., trade name: KURARAY polyol C770) having a 3-methylpentane structure was added dropwise over 4 hours. After stirring for 2 hours at 40 C., the temperature was again increased to 70 C. over 1 hour. After that, 2 mol of 2-hydroxyethylacrylate (manufactured by OSAKA ORGANIC CHEMICAL INDUSTRY LTD., trade name: HEA) was added dropwise thereto over 2 hours, and by stirring again for 2 hours, urethane diacrylate (UA1) was synthesized.

[0104] The weight average molecular weight of urethane diacrylate (UA1), which has been measured by GPC system (manufactured by Tosoh Corporation, trade name: HLC-8220 GPC) at following conditions, was 6100 in WI ifs of standard polystyrene.

(GPC Measurement Conditions)

[0105] Column: TSK-Gel Super HZM-M, TSK-Gel HZM-M, TSK-Gel HZ2000

[0106] Eluent: THF

[0107] Flow rate: 0.35 ml/min

[0108] Injection amount: 10 l

[0109] Column temperature: 40 C.

[0110] Detector: Ultraviolet-8020.

[Synthesis Example 2] Synthesis of Urethane Diacrylate (UA2)

[0111] To the same apparatus as the Synthesis Example 1, 2 mol of 2-hydroxyethylacrylate (manufactured by OSAKA ORGANIC CHEMICAL INDUSTRY LTD., trade name: HEA), 200 ppm of n-butyl tin dilauric acid (manufactured by ADEKA CORPORATION, trade name: ADK STAB BT-11), and 500 ppm of hydroquinone monomethyl ether (manufactured by Kawaguchi Chemical Industry Co., Ltd., trade name: MQ) were added and heated to 60 C. By using a dropping funnel, 1 mol of isophorone diisocyanate (manufactured by Sumika Bayer Urethane, trade name: DESMODUR I) was added dropwise over 4 hours. Thereafter, by stirring for 2 hours at 60 C., urethane diacrylate (UA2) was synthesized. The weight average molecular weight of urethane diacrylate (UA2) as measured in the same manner as the Synthesis Example 1 was found to be 580.

Example 1

(1) Preparation and Coating of Active Energy Ray Curable Resin Composition

[0112] The resin composition which has been prepared based on the blending ratio shown in Table 1 was coated by bar coating on a polycarbonate resin plate (manufactured by TEIJIN LIMITED, trade name: PANLITE L-1225Z) with thickness of 3 mm such that the thickness of a cured coating film was 8 m. Subsequently, the coated resin plate was heated for 3 minutes in an oven at 60 C. to evaporate the organic solvent.

[0113] (2) Evaluation of Curing Property of Coating Film

[0114] The dried coating film which has been obtained from above (1) was irradiated in air with ultraviolet ray with peak illuminance of 10 mW/cm.sup.2 in the wavelength of 250 nm to 260 nm in which the cumulative light dose is 5.8 mJ/cm.sup.2 in this wavelength range, ultraviolet ray with peak illuminance of 39 mW/cm.sup.2 in the wavelength of 280 nm to 320 nm in which the cumulative light dose is 27 mJ/cm.sup.2 in this wavelength range, or ultraviolet ray with peak illuminance of 38 mW/cm.sup.2 in the wavelength of 395 nm to 445 nm in which the cumulative light dose is 27 mJ/cm.sup.2 in this wavelength range by using a high pressure mercury lamp. Then, according to a brief contact of a finger tip, determination was made to see whether or not the film is tack free. For a case in which the film is not tack free, the above ultraviolet ray irradiation process was repeated till to be tack free. According to the number of ultraviolet ray irradiation, the curing property was evaluated based on the following standard. The evaluation results are shown in Table 1.

[0115] (Evaluation Standard for Curing Property)

[0116] A: Number of ultraviolet ray irradiation is 1 to 2 times

[0117] B: Number of ultraviolet ray irradiation is 3 to 5 times

[0118] F: Number of ultraviolet ray irradiation is 6 times or more.

[0119] (3) Evaluation of Abrasion Resistance of Cured Coating Film

[0120] The dried coating film which has been obtained from the above (1) was cured by irradiating in air with ultraviolet ray with peak illuminance of 37 mW/cm.sup.2 in the wavelength of 250 nm to 260 nm in which the cumulative light dose is 470 mJ/cm.sup.2 in this wavelength range, ultraviolet ray with peak illuminance of 150 mW/cm.sup.2 in the wavelength of 280 nm to 320 nm in which the cumulative light dose is 2200 mJ/cm.sup.2 in this wavelength range, or ultraviolet ray with peak illuminance of 140 mW/cm.sup.2 in the wavelength of 395 nm to 445 nm in which the cumulative light dose is 2200 mJ/cm.sup.2 in this wavelength range by using a high pressure mercury lamp. The cured coating film formed on a surface of a resin molded article having a cured coating film which has been obtained as described above was subjected to abrasion with steel wool #000 manufactured by BONSTAR SALES Co., Ltd., which is provided on a flat surface abrasion tester manufactured by Coating Tester Co., Ltd., at conditions including a load of 250 g/cm.sup.2 and reciprocation number of 50. The haze increase caused by the abrasion was calculated from the haze value measured before and after the abrasion according to JIS-K7105 by using a haze meter HM-65W manufactured by MURAKAMI COLOR RESEARCH LABORATORY CO., Ltd. The abrasion resistance was evaluated according to the obtained haze increase based on the following standard. The evaluation results are shown in Table 1.

[0121] (Evaluation Standard for Abrasion Resistance)

[0122] A: Haze increase is less than 1%

[0123] B: Haze increase is 1% or more but less than 3%

[0124] F: Haze increase is 3% or more.

[0125] (4) Evaluation of Weather Resistance of Resin Molded Article with Cured Coating Film

[0126] For the resin molded article with a cured coating film which has been produced in the same manner as the above (3), the haze value and yellow index (YI) value before and after the weather resistance test performed according to the following method were measured. The haze value was measured by using the haze meter that is manufactured by MURAKAMI COLOR RESEARCH LABORATORY CO., Ltd. The YI value was calculated using the following equation from the tristimulus values (X, Y, Z) that are measured by using an instantaneous multichannel photospectroscopic system (trade name: MCPD-3000, manufactured by Otsuka Electronics Co., LTD.).

Yellow index (YI) value=100(1.28X1.06Z)/Y

[0127] (Method for Weather Resistance Test)

[0128] Device for use: Weather resistance tester, Sunshine Carbon Weather-Ometer (manufactured by Suga Test Instruments Co., Ltd., model WELSUN-HC-B)

[0129] Test conditions: Black panel temperature of 633 C., 1500 hours with a cycle including raining for 12 minutes and irradiation for 48 minutes

[0130] <Evaluation of Weather Resistance Based on Transparency>

[0131] The transparency was evaluated according to the haze increase after the weather resistance test based on the following criteria. The evaluation results are shown in Table 1.

[0132] (Evaluation Criteria for Transparency)

[0133] A: Haze increase is less than 0.5%

[0134] B: Haze increase is 0.5% or more but less than 3%

[0135] F: Haze increase is 3% or more.

[0136] <Evaluation of Weather Resistance Based on Yellowness>

[0137] The yellowness was evaluated according to the YI increase before and after the weather resistance test based on the following criteria. The evaluation results are shown in Table 1.

[0138] (Evaluation Criteria for Yellowness)

[0139] A: YI increase is less than 1

[0140] B: YI increase is 1 or more but less than 3

[0141] F: YI increase is 3 or more.

Examples 2 to 14 and Comparative Examples 1 to 6

[0142] The active energy ray curable resin composition was prepared in the same manner as Example 1 except that the composition of the active energy ray curable resin composition is changed to the blendings that are shown in Tables 1 to 3. By using the resin composition, a resin molded article having a cured coating film was produced and subjected to the evaluation. The evaluation results are shown in Table 1 to Table 3.

TABLE-US-00001 TABLE 1 Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 Coating Component A UA1 25 40 10 25 25 25 composition UA2 25 (parts) Component B DPHA 75 60 90 75 65 75 DPCA-20 75 Other polymerizable TMPTA 10 component Component C1 BNP 0.67 0.67 0.67 0.67 0.67 0.67 Irg. 127 0.67 Component C2 MMMP 0.67 0.67 0.67 0.67 0.67 0.67 0.67 Component C3 TPO 1.33 1.33 1.33 1.33 1.33 1.33 1.33 BTPO Other MPG 0.67 0.67 0.67 0.67 0.67 0.67 0.67 photopolymerization initiator Component D HHBT 6.67 6.67 6.67 6.67 6.67 6.67 6.67 OHBT HBPB Component E Tin. 123 0.5 0.5 0.5 0.5 0.5 0.5 0.5 Surface modifier L-7001 0.2 0.2 0.2 0.2 0.2 0.2 0.2 Dilution solvent PGM 189 189 189 189 189 189 189 Butyl acetate 8.33 8.33 8.33 8.33 8.33 8.33 8.33 ECA 5 5 5 5 5 5 5 Total 313.04 313.04 313.04 313.04 313.04 313.04 313.04 Evaluation Curing property Number of 2 2 1 1 2 3 2 results UV irradiation Evaluation A A A A A B A Abrasion resistance Haze increase 0.3 1.1 0.2 0.1 0.8 0.2 0.3 (%) Evaluation A B A A A A A Weather Transparency Haze increase 0.1 0.1 0.3 2.1 0.1 1.9 0.2 resistance (%) Evaluation A A A B A B A Yellowness YI increase 0.6 0.7 0.5 0.8 0.5 0.7 0.7 Evaluation A A A A A A A

TABLE-US-00002 TABLE 2 Example 8 Example 9 Example 10 Example 11 Example 12 Example 13 Example 14 Coating Component A UA1 25 25 25 25 25 25 25 composition UA2 (parts) Component B DPHA 75 75 75 75 75 75 75 DPCA-20 Other polymerizable TMPTA component Component C1 BNP 0.67 0.67 0.67 0.67 0.67 0.67 0.67 Irg. 127 Component C2 MMMP 1.33 0.67 0.67 0.67 0.67 0.67 0.67 Component C3 TPO 1.33 1.33 1.33 1.33 1.33 1.33 BTPO 0.67 Other MPG 0.67 0.67 0.67 0.67 0.67 0.67 photopolymerization initiator Component D HHBT 6.67 6.67 6.67 10 6.67 OHBT 6.67 HBPB 6.67 Component E Tin. 123 0.5 0.5 0.5 0.5 0.5 0.5 Surface modifier L-7001 0.2 0.2 0.2 0.2 0.2 0.2 0.2 Dilution solvent PGM 189 189 189 189 189 189 189 Butyl acetate 8.33 8.33 8.33 8.33 8.33 8.33 8.33 ECA 5 5 5 5 5 5 5 Total 313.7 312.38 312.37 316.37 313.04 313.04 312.54 Evaluation Curing property Number 1 2 2 2 2 2 2 results of UV irradiation Evaluation A A A A A A A Abrasion resistance Haze 0.3 0.3 0.3 0.4 0.7 0.3 0.2 increase (%) Evaluation A A A A A A A Weather Transparency Haze 0.2 0.2 0.1 0.1 0.2 0.2 0.5 resistance increase (%) Evaluation A A A A A A B Yellowness YI increase 0.8 0.8 0.7 0.4 0.2 1.5 0.8 Evaluation A A A A A B A

TABLE-US-00003 TABLE 3 Comparative Comparative Comparative Comparative Comparative Comparative Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Coating Component A UA1 100 25 25 25 25 composition UA2 (parts) Component B DPHA 100 75 75 75 75 DPCA-20 Other polymerizable TMPTA component Component C1 BNP 0.67 0.67 0.84 1.11 0.67 Irg. 127 Component C2 MMMP 0.67 0.67 0.84 1.11 0.67 Component C3 TPO 1.33 1.33 1.66 1.66 1.33 BTPO Other MPG 0.67 0.67 0.84 0.84 1.11 0.67 photopolymerization initiator Component D HHBT 6.67 6.67 6.67 6.67 6.67 OHBT HBPB Component E Tin. 123 0.5 0.5 0.5 0.5 0.5 0.5 Surface modifier L-7001 0.2 0.2 0.2 0.2 0.2 0.2 Dilution solvent PGM 189 189 189 189 189 189 Butyl acetate 8.33 8.33 8.33 8.33 8.33 8.33 ECA 5 5 5 5 5 5 Total 313.04 313.04 313.04 313.04 313.03 306.37 Evaluation Curing property Number of 1 4 5< 5< 3 1 results UV irradiation Evaluation A B F F B A Abrasion resistance Haze increase 0.1 7.8 1.5 0.4 0.3 0.2 (%) Evaluation A F B A A A Weather Transparency Haze increase 5.8 0.1 0.2 0.2 2.5 3.1 resistance (%) Evaluation F A A A F F Yellowness YI increase 1.2 0.5 0.8 0.7 1.7 8.2 Evaluation B A A A B F

[0143] The absorption coefficient at 254 nm, 302 nm and 405 nm of the photopolymerization initiator used in Examples and Comparative Examples is described in Table 4.

TABLE-US-00004 TABLE 4 Absorption coefficient [ml/(g .Math. cm)] Photopolymerization initiator 254 nm 302 nm 405 nm BNP 91430 1720 0 Irg. 127 73400 1124 7 MMMP 3936 60630 0 TPO 5096 3004 165 BTPO 19530 18230 899 MPG 9245 634 0

[0144] The abbreviations shown in Table 1 to Table 4 are as described below. [0145] UA1: urethane diacrylate (UA1) synthesized in Synthesis Example 1 [0146] UA2: urethane diacrylate (UA2) synthesized in Synthesis Example 2 [0147] DPHA: dipentaerythritol hexaacrylate (manufactured by Nippon Kayaku Co., Ltd., trade name: KAYARAD DPHA) [0148] DPCA-20: dipentaerythritol hexaacrylate which is modified with 2 caprolactones per molecule (manufactured by Nippon Kayaku Co., Ltd., trade name: KAYARAD DPCA-20) [0149] TMPTA: trimethylolpropane triacrylate (manufactured by OSAKA ORGANIC CHEMICAL INDUSTRY LTD., trade name: TMP3A-3) [0150] BNP: benzophenone (manufactured by DAIDO CHEMICAL CORPORATION, trade name: BENZOPHENONE) [0151] Irg.127: 2-hydroxy-1-{4-[4-(2-hydroxy-2-methyl-propionyl)-benzyl]phenyl}-2-methyl-propan-1-one (manufactured by BASF, trade name: IRGACURE 127) [0152] MMMP: 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one (manufactured by BASF, trade name: IRGACURE 907) [0153] TPO: 2,4,6-trimethylbenzoyl diphenylphosphine oxide (manufactured by BASF, trade name: Lucirin TPO) [0154] BTPO: bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide (manufactured by BASF, trade name: IRGACURE 819) [0155] MPG: methylphenyl glyoxylate (manufactured by Showa Kosan Co., LTD., trade name: VICURE 55) [0156] HHBT: mixture of 2-[4-(2-hydroxy-3-dodecyloxy-propyl)oxy-2-hydroxyphenyl]-4,6-[bis(2,4-dimethylphenyl)-1,3,5-triazine and 2-[4-(2-hydroxy-3-tridecyloxy-propyl)oxy-2-hydroxyphenyl]-4,6-[bis(2,4-dimethylphenyl)-1,3,5-triazine (manufactured by BASF, trade name: TINUVIN 400) [0157] OHBT: 2-[4-(octyl-2-methylethanoate)oxy-2-hydroxyphenyl]-4,6-[bis(4-phenylphenyl)]-1,3,5-triazine (manufactured by BASF, trade name: TINUVIN 479) [0158] HBPB: 2-(2-hydroxy-5-tert-butylphenyl)-2H-benzotriazole (manufactured by BASF, trade name: TINUVIN PS) [0159] Tin.123: reaction product between a diester compound of decanedicarboxylic acid and 2,2,6,6-tetramethyl-1-octoxy-4-piperidinol, 1,1-dimethylethylhydroperoxide, and octane (manufactured by BASF, trade name: TINUVIN 123) [0160] L-7001: octamethylcyclotetrasiloxane (manufactured by Dow Corning Toray Co., Ltd., trade name: L-7001) [0161] PGM: propylene glycol monomethyl ether (manufactured by Daicel Corporation, trade name: methoxypropanol) [0162] Butyl acetate: butyl acetate (manufactured by The Nippon Synthetic Chemical Industry Co., Ltd., trade name: butyl acetate) [0163] ECA: ethylcarbitol acetate (manufactured by Daicel Corporation, trade name: ethyl diglycol acetate)

[0164] From the evaluation results shown in Table 1 to Table 3, it was found that all of the curing property, abrasion resistance, and weather resistance are excellent in the Examples in which the component A, the component B, the component C1, the component C2, the component C3, and the component D are contained.

[0165] On the other hand, the transparency after the weather resistance test was poor in Comparative Example 1 in which the component A is not contained, and the abrasion resistance was poor in Comparative Example 2 in which the component B is not contained. The curing property was poor in Comparative Example 3 in which the component C1 is not contained and in Comparative Example 4 in which the component C2 is not contained. The transparency after the weather resistance test was poor in Comparative Example 5 in which the component C3 is not contained. The transparency and yellowness after the weather resistance test were poor in Comparative Example 6 in which the component D is not contained.