A UV light-cured material and a method for preparing the same

Abstract

This invention discloses a UV-curable material and its preparation method, belonging to the field of radiation-curable materials technology. It is characterized by comprising the following components by mass parts: 30-40 parts vinyl-functionalized polyurethane acrylate oligomer, 50-60 parts polythiol compound, and 2-10 parts photoinitiator. This invention uses vinyl-functionalized polyurethane acrylate oligomer as the photocurable unit structure, and the curing system composed of polyfunctional thiol compound can improve the oxygen inhibition problem of polyurethane acrylate cured materials. Furthermore, the higher functional structure enables a higher degree of curing crosslinking. When applied to UV-curable materials, it can achieve good flexibility, adhesion, and thermal stability.

Description

Technical fields:

[0001] This invention belongs to the field of radiation curing materials technology, and more specifically relates to a UV curable material and its preparation method. Background technology:

[0002] Photocuring refers to the curing process of a monomer, oligomer, or polymer matrix under light induction. Existing photocurable materials primarily use polyurethane acrylates as the photocurable monomer. Polyurethane acrylates possess chemical resistance, excellent flexibility, and various tunable properties. Furthermore, highly functionalized polyurethane acrylates increase the crosslinking density of the cured material, forming a highly dense structure, thus giving the cured material better scratch resistance, chemical resistance, and mechanical properties. However, the photosensitive functional structures of hyperbranched polyurethane (meth)acrylates are mostly located only at the molecular ends of the photocurable unit structure. Due to its free radical polymerization mechanism's sensitivity to oxygen inhibition and steric hindrance, its crosslinking density is adversely affected, leading to incomplete crosslinking of functional groups and consequently impacting the application performance of the cured material. Summary of the Invention:

[0003] A first aspect of the present invention is to provide a UV-curable material, characterized in that it comprises the following components in parts by mass:

[0004] Vinyl-functionalized polyurethane acrylate oligomers 30-40

[0005] Polythiol compounds 50-60

[0006] Photoinitiator 2-10.

[0007] Furthermore:

[0008] The polythiol compound is selected from any one of pentaerythritol tetrakis(3-mercaptopropionic acid), trimethylolpropane tris(3-mercaptopropionate), and 1,4-butanediol bis(mercaptoacetate).

[0009] The photoinitiator is preferably 2-hydroxy-2-methyl-1-phenyl-1-propanone.

[0010] The vinyl-functionalized polyurethane acrylate oligomer is selected from any one of the following compounds:

[0011]

[0012]

[0013]

[0014] In the formula: R1 is selected from hydrogen, C1-C 20Alkyl, benzyl, C6-C 14 Aryl, C6-C 14 Oxyheterocycles, C6-C 14 Nitrogen heterocycles, C6-C 14 Sulfur heterocycles, C5-C 20 Oxygen heterochain, C5-C 20 Nitrogen heterochains and C5-C 20 Any of the sulfur heterochains; R2, R3, and R4 are each independently selected from C1-C2. 20 Alkyl, benzyl, C6-C 14 Aryl, C6-C 14 Oxyheterocycles, C6-C 14 Nitrogen heterocycles, C6-C 14 Sulfur heterocycles, C5-C 20 oxygen heterochain, C5-C 20 Nitrogen heterochains and C5-C 20 Any of the sulfur heterochains;

[0015] r1, r2, r3, and r4 are selected from C1-C 20 Alkyl, benzyl, C6-C 14 Aryl, C6-C 14 Oxyheterocycles, C6-C 14 Nitrogen heterocycles, C6-C 14 Sulfur heterocycles, C5-C 20 oxygen heterochain, C5-C 20 Nitrogen heterochains and C5-C 20 Any of the sulfur heterochains;

[0016] n, n1, n2, n3, and n4 are all positive integers, and n, n1, n2, n3, and n4 ≥ 1.

[0017] The present invention discloses a UV-curable material that uses a vinyl-functionalized polyurethane acrylate oligomer as the photocurable unit structure. It can utilize the high functionalization characteristics of the oligomer uniformly distributed in the molecular structure and the curing system composed of polyfunctional thiols with multiple curing mechanisms to prepare curable materials with more diverse application properties.

[0018] Furthermore:

[0019] The vinyl-functionalized polyurethane acrylate oligomer is of formula (II).

[0020]

[0021] R2 is selected from C1-C 20 Alkyl, benzyl, C6-C 14 Aryl, C6-C 14 Oxyheterocycles, C6-C 14 Nitrogen heterocycles, C6-C14 Sulfur heterocycles, C5-C 20 oxygen heterochain, C5-C 20 Nitrogen heterochains and C5-C 20 Any of the sulfur heterochains; r2 is selected from C1-C 20 Alkyl, benzyl, C6-C 14 Aryl, C6-C 14 Oxyheterocycles, C6-C 14 Nitrogen heterocycles, C6-C 14 Sulfur heterocycles, C5-C 20 oxygen heterochain, C5-C 20 Any one of nitrogen heterochains and C5-C20 sulfur heterochains; n1 and n2 are both positive integers, and n1 and n2 ≥ 1.

[0022] Furthermore, the vinyl-functionalized polyurethane acrylate oligomer is preferably a compound of formula (II), wherein R2 is preferably derived from... One type; r2 preferred

[0023] The vinyl-functionalized polyurethane acrylate oligomer can be prepared by the following method: (1) mixing vinyl-functionalized polyether polyol, diisocyanate and catalyst, and reacting at 50-150℃ for 1-20 hours to obtain a prepolymer; (2) adding hydroxyethyl methacrylate to the prepared prepolymer and reacting to obtain the vinyl-functionalized polyurethane acrylate oligomer.

[0024] The vinyl-functionalized polyether polyol is selected from one of the following chemical formulas:

[0025]

[0026] R2 is selected from C1-C 20 Alkyl, benzyl, C6-C 14 Aryl, C6-C 14 Oxyheterocycles, C6-C 14 Nitrogen heterocycles, C6-C 14 Sulfur heterocycles, C5-C 20 oxygen heterochain, C5-C 20 Nitrogen heterochains and C5-C 20 Any of the sulfur heterochains; n1 and n2 are both positive integers, and n1 and n2 ≥ 1.

[0027] The second aspect of this invention is to provide a method for preparing a UV-curable material, characterized in that 30-40 parts by weight of vinyl-functionalized polyurethane acrylate oligomer, 50-60 parts by weight of polythiol compound, and 2-10 parts by weight of photoinitiator are mixed in a certain proportion, and then the mixture is reacted under UV irradiation for 1-100 minutes to obtain a UV-curable material.

[0028] The beneficial effects of this invention are as follows:

[0029] This invention uses ethylene-functional polyurethane acrylate oligomers as the photocurable unit structure and a curing system composed of multifunctional thiol compounds. This system can improve the oxygen inhibition problem of polyurethane acrylate curing materials, and the higher functional structure can achieve a higher degree of curing crosslinking. When applied to UV curing materials, it can achieve good flexibility, adhesion and thermal stability. Attached image description:

[0030] Figure 1 The NMR spectrum of the vinyl-functionalized polyurethane acrylate oligomer P1 prepared in this invention is shown.

[0031] Figure 2 The NMR spectrum of the vinyl-functionalized polyurethane acrylate oligomer P2 prepared in this invention is shown.

[0032] Figure 3 The NMR spectrum of the vinyl-functionalized polyurethane acrylate oligomer P3 prepared in this invention is shown.

[0033] Figure 4 The NMR spectrum of the vinyl-functionalized polyurethane acrylate oligomer P4 prepared in this invention is shown.

[0034] Figure 5 The NMR spectrum of the vinyl-functionalized polyurethane acrylate oligomer P5 prepared in this invention is shown.

[0035] Figure 6 The NMR spectrum is that of the vinyl-functionalized polyurethane acrylate oligomer P6 prepared in this invention. Detailed implementation method:

[0036] The present invention will now be described in detail with reference to specific embodiments. These embodiments will help those skilled in the art to further understand the present invention, but do not limit the invention in any way. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention. These all fall within the scope of protection of the present invention.

[0037] The raw materials involved in the embodiments of the present invention, wherein;

[0038] The polythiol compounds were obtained from PETMP, which is commercially available.

[0039] The photoinitiator used was Irgacure 1173, which was commercially available.

[0040] The vinyl-functionalized polyurethane acrylate oligomers P1-P6 were prepared in-house, and their preparation method is as follows:

[0041] 728.1 mg (3.3 mmol) of IPDI and 18.6 mg of dibutyltin dilaurate were added to a three-necked round-bottom flask. 1136.0 mg (1.6 mmol) of a vinyl-functionalized polyether polyol (R2 being cyclohexyl) was slowly added titrated into the reaction flask, maintaining the reaction temperature at 55°C. The addition was completed over 30 minutes, and the mixture was stirred at 55°C for 1 hour. Then, 416.5 mg (3.2 mmol) of hydroxyethyl methacrylate was added to the reaction system, and the mixture was stirred at 55°C for another 1.5 hours to obtain the vinyl-functionalized polyurethane acrylate oligomer P1. The molecular weight M of P1 was determined by GPC. n For 5000, the NMR hydrogen spectrum is as follows: Figure 1 As shown. P1: 1 H NMR (125MHz, CDCl3): δ=7.00(q),6.17(o1),5.74-5.71(e),5.63(o2),5.35-5.27(f),4.06-3 .87(c,m,n),3.44-3.20(b,d,g),2.94-2.92(l),1.98(p),1.81-1.44(a,h,j,k),0.95(i)ppm.

[0042] 728.1 mg (3.3 mmol) of IPDI and 18.6 mg of dibutyltin dilaurate were added to a three-necked round-bottom flask. 1152.1 mg (1.6 mmol) of a vinyl-functionalized polyether polyol (R2 being phenyl) was slowly added titrated into the reaction flask, maintaining the reaction temperature at 55°C. The addition was completed over 30 minutes, and the mixture was stirred at 55°C for 1 hour. Then, 416.5 mg (3.2 mmol) of hydroxyethyl methacrylate was added to the reaction system, and the mixture was stirred at 55°C for another 1.5 hours to obtain the vinyl-functionalized polyurethane acrylate oligomer P2. The molecular weight M of P2 was determined by GPC. n The value is 6000. The hydrogen NMR spectrum is as follows: Figure 2 As shown. P2: 1 H NMR (125MHz, CDCl3): δ = 7.31(a), 6.16(o1), 5.74(e), 5.63(o2), 5.33-5.28(f), 4.64-4.41(b) ),4.30-4.01(c,m,n),3.75-3.47(b,g),2.89(l),1.97(p),1.86-1.70(h,j,k),0.91(i)ppm.

[0043] 701.5 mg (3.1 mmol) of IPDI and 18.5 mg of dibutyltin dilaurate were added to a three-necked round-bottom flask. 1185.0 mg (1.5 mmol) of a butyl-containing vinyl-functionalized polyether polyol (R2) was slowly added titrated into the reaction flask, maintaining the reaction temperature at 55°C. The addition was completed over 30 minutes, and the mixture was stirred at 55°C for 1 hour. Then, 400.6 mg (3.1 mmol) of hydroxyethyl methacrylate was added to the reaction system, and the mixture was stirred at 55°C for another 1.5 hours to obtain the vinyl-functionalized polyurethane acrylate oligomer P3. The molecular weight M of P3 was determined by GPC. n The value is 6500. The hydrogen NMR spectrum is as follows: Figure 3 As shown. P3: 1 H NMR (125MHz, CDCl3): δ=6.16(o1),5.73-5.68(e),5.61(o2),5.34-5.23(f),4.31-3.87 (c,m,n),3.54-3.39(b,g),2.92-2.90(l),1.97(p),1.86-1.63(a,h,j,k),0.93(i)ppm.

[0044] 710.2 mg (3.1 mmol) of IPDI and 18.6 mg of dibutyltin dilaurate were added to a three-necked round-bottom flask. 1153.1 mg (1.5 mmol) of a vinyl-functionalized polyether polyol (R2 being an ether group) was slowly added titrated into the reaction flask, maintaining the reaction temperature at 55°C. The addition was completed over 30 minutes, and the mixture was stirred at 55°C for 1.5 hours. Then, 405.6 mg (3.1 mmol) of hydroxyethyl methacrylate was added to the reaction system, and the mixture was stirred at 55°C for another hour to obtain the vinyl-functionalized polyurethane acrylate oligomer P4. The molecular weight M of P4 was determined by GPC. n The value is 5000. The hydrogen NMR spectrum is as follows: Figure 4 As shown. P4: 1 H NMR (125MHz, CDCl3): δ=6.16-6.14(o1),5.74-5.70(e),5.60(o2),5.37-5.26(f),4.33-3.9 4(c,m,n),3.70-3.44(a,b,d,g),2.92-2.90(l),1.96(p),1.86-1.64(h,j,k),0.93(i)ppm.

[0045] 749.5 mg (3.2 mmol) of IPDI and 17.5 mg of dibutyltin dilaurate were added to a three-necked round-bottom flask. 1008.1 mg (1.6 mmol) of a vinyl-functionalized polyether polyol (R2 being vinyl) was slowly added titrated into the reaction flask, maintaining the reaction temperature at 55°C. The addition was completed over 30 minutes, and the mixture was stirred at 55°C for 1 hour. Then, 428.0 mg (3.2 mmol) of hydroxyethyl methacrylate was added to the reaction system, and the mixture was stirred at 55°C for another 1.5 hours to obtain the vinyl-functionalized polyurethane acrylate oligomer P5. The molecular weight M of P5 was determined by GPC. n The value is 7000. The hydrogen NMR spectrum is as follows: Figure 5 As shown. P5: 1 H NMR (125MHz, CDCl3): δ=6.16-6.14(o1),5.72-5.70(e),5.61(o2),5.31-5.26(a,f),4.3 3-3.96(b,c,m,n),3.59-3.43(d,g),2.92(l),1.97(p),1.78-1.70(h,j,k),0.93(i)ppm.

[0046] 736.9 mg (3.2 mmol) of IPDI and 17.9 mg of dibutyltin dilaurate were added to a three-necked round-bottom flask. 1054.3 mg (1.6 mmol) of a vinyl-functionalized polyether polyol (R2 being vinyl) was slowly added titrated into the reaction flask, maintaining the reaction temperature at 55°C. The addition was completed over 30 minutes, and the mixture was stirred at 55°C for 1 hour. Then, 420.8 mg (3.2 mmol) of hydroxyethyl methacrylate was added to the reaction system, and the mixture was stirred at 55°C for another 1.5 hours to obtain the vinyl-functionalized polyurethane acrylate oligomer P6. The molecular weight M of P6 was determined by GPC. n The value is 6500. The hydrogen NMR spectrum is as follows: Figure 6 As shown. P6: 1 H NMR (125MHz, CDCl3): δ=6.16-6.14(o1),5.72-5.70(e),5.61-5.60(o2),5.31-5.26(f),4.3 3-4.00(c,m,n),3.75-3.43(b,g),2.92(l),1.97-1.95(p),1.86-1.69(h,j,k),0.93(i)ppm.

[0047] Example 1

[0048] A UV-curable material comprising the following components in parts by weight

[0049] PETMP 57

[0050] P1 38

[0051] Irgacure 1173 5

[0052] Preparation method: In a dark room, the raw materials of each component are mixed evenly in proportion, and then the mixture is reacted under UV irradiation for 60 minutes to obtain a UV-curable material.

[0053] Examples 2-6:

[0054] The preparation method is the same as in Example 1, except that the amount of vinyl-functionalized polyurethane acrylate oligomers P1-P6 is adjusted as shown in Table 1 to test the effect of vinyl-functionalized polyurethane acrylate oligomers P1-P6 on the performance of photocurable materials.

[0055]

[0056]

[0057] Performance testing of photocurable materials:

[0058] The test methods for the performance of photocurable materials are as follows:

[0059] Tensile testing: The photocurable materials obtained in Examples 1-6 were subjected to tensile testing using an Instron 3365 electronic universal tensile testing machine at a speed of 5 mm / min. The accurate values ​​of modulus, breaking strength and elongation at break were obtained by averaging the values ​​of five experiments.

[0060] Thermal performance testing: A thermogravimetric analyzer (Discovery TGA550) was used to determine the thermal stability of the cured material under a nitrogen atmosphere in the range of 50 to 700℃ with a heating rate of 10℃·min-1. The temperature at which the mass degradation reached 5% was taken as the heat resistance temperature (T5) of the material.

[0061] Flexibility Test: The flexibility of the UV-cured material was measured using a conical mandrel (QTX-1731) for coating elasticity testing, according to the GB 1731-93 test method. The smallest mandrel that allows the UV-cured film to bend 180° around the conical mandrel without cracking within 1–3 seconds is acceptable. Conical mandrel sizes are available in Φ2±0.05mm, Φ3±0.05mm, Φ4±0.05mm, and Φ5±0.05mm (Φ2±0.05mm indicates the best flexibility).

[0062] Adhesion test: The adhesion of the cured film was tested according to GB / T9286-1998. A cross-cut pattern was cut into the coating with a cross-cutting tool, with the cut extending to the substrate. Then, the coating was brushed five times diagonally. Adhesive tape was then applied to the cut and pulled off. The condition of the grid area was observed and the adhesion grade was recorded. The adhesion grade range was 5B to 1B, with 5B being the highest grade and 1B being the lowest grade.

[0063] The properties of the UV-curable materials prepared in Examples 1-6 are shown in Table 2 after testing.

[0064] Table 2

[0065]

[0066]

[0067] Test Result Analysis:

[0068] As can be seen from Table 1, the UV curable material prepared by this invention exhibits excellent toughness and good thermal stability because the curing monomer is a vinyl-functionalized polyurethane acrylate oligomer. The T5 temperature is above 210℃.

Claims

1. A UV-curable material, characterized in that, Comprising the following components in parts by weight: 30-40 parts vinyl-functionalized polyurethane acrylate oligomer Polythiol compounds 50-60 Photoinitiator 2-10; The vinyl-functionalized polyurethane acrylate oligomer is selected from any one of the following compounds: In the formula: R1 is selected from hydrogen, C1-C 20 Alkyl, benzyl, C6-C 14 Aryl, C6-C 14 Oxyheterocycles, C6-C 14 Nitrogen heterocycles, C6-C 14 Sulfur heterocycles, C5-C 20 oxygen heterochain, C5-C 20 Nitrogen heterochains and C5-C 20 Any of the sulfur heterochains; R2, R3, and R4 are each independently selected from C1-C2. 20 Alkyl, benzyl, C6-C 14 Aryl, C6-C 14 Oxyheterocycles, C6-C 14 Nitrogen heterocycles, C6-C 14 Sulfur heterocycles, C5-C 20 oxygen heterochain, C5-C 20 Nitrogen heterochains and C5-C 20 Any of the sulfur heterochains; r1, r2, r3, and r4 are selected from C1-C 20 Alkyl, benzyl, C6-C 14 Aryl, C6-C 14 Oxyheterocycles, C6-C 14 Nitrogen heterocycles, C6-C 14 Sulfur heterocycles, C5-C 20 oxygen heterochain, C5-C 20 Nitrogen heterochains and C5-C 20 Any of the sulfur heterochains; n, n1, n2, n3, and n4 are all positive integers, and n, n1, n2, n3, and n4 ≥ 1.

2. The UV-curable material according to claim 1, characterized in that: The polythiol compound is selected from any one of pentaerythritol tetrakis(3-mercaptopropionic acid), trimethylolpropane tris(3-mercaptopropionate), and 1,4-butanediol bis(mercaptoacetate).

3. The UV-curable material according to claim 1, characterized in that: The photoinitiator is 2-hydroxy-2-methyl-1-phenyl-1-propanone.

4. The UV-curable material according to claim 1, characterized in that: The vinyl-functionalized polyurethane acrylate oligomer is selected from compounds represented by formula (II): R2 is selected from C1-C 20 Alkyl, benzyl, C6-C 14 Aryl, C6-C 14 Oxyheterocycles, C6-C 14 Nitrogen heterocycles, C6-C 14 Sulfur heterocycles, C5-C 20 oxygen heterochain, C5-C 20 Nitrogen heterochains and C5-C 20 Any of the sulfur heterochains; r2 is selected from C1-C 20 Alkyl, benzyl, C6-C 14 Aryl, C6-C 14 Oxyheterocycles, C6-C 14 Nitrogen heterocycles, C6-C 14 Sulfur heterocycles, C5-C 20 oxygen heterochain, C5-C 20 Any one of nitrogen heterochains and C5-C20 sulfur heterochains; n1 and n2 are both positive integers, and n1 and n2 ≥ 1.

5. The UV-curable material according to claim 1, characterized in that: The vinyl-functionalized polyurethane acrylate oligomer is a compound represented by formula (II), wherein, R2 is selected from One type; r2 is 6. The UV-curable material according to claim 1, characterized in that: The vinyl-functionalized polyurethane acrylate oligomer is prepared by the following method: (1) mixing vinyl-functionalized polyether polyol, diisocyanate and catalyst, and reacting at 50-150℃ for 1-20 hours to obtain a prepolymer; (2) adding hydroxyethyl methacrylate to the prepared prepolymer and reacting to obtain the vinyl-functionalized polyurethane acrylate oligomer.

7. A UV-curable material according to claim 6, characterized in that: The vinyl-functionalized polyether polyol is selected from one of the following chemical formulas: R2 is selected from C1-C 20 Alkyl, benzyl, C6-C 14 Aryl, C6-C 14 Oxyheterocycles, C6-C 14 Nitrogen heterocycles, C6-C 14 Sulfur heterocycles, C5-C 20 oxygen heterochain, C5-C 20 Nitrogen heterochains and C5-C 20 Any of the sulfur heterochains; n1 and n2 are both positive integers, and n1 and n2 ≥ 1.

8. A method for preparing the UV-curable material according to claim 1, characterized in that, Mix 30-40 parts by weight of vinyl-functionalized polyurethane acrylate oligomer, 50-60 parts by weight of polythiol compound, and 2-10 parts by weight of photoinitiator in a certain proportion, and then react the mixture under UV irradiation for 1-100 minutes to obtain a UV-curable material.

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