Ultraviolet curing halogen-free flame retardant, solder resist ink containing flame retardant and application

Abstract

The invention discloses an ultraviolet curing halogen-free flame retardant, solder resist ink containing the flame retardant and application, and belongs to the technical field of printing materials. The structural general formula of the ultraviolet curing halogen-free flame retardant is as shown in the following formula (I): # imgabs 0 #, wherein A is selected from at least one of # imgabs 1 #; b is selected from at least one of # imgabs2 #; and D is a group containing alkyl. The phosphorus-nitrogen synergistic flame retardant can be obtained by introducing a phosphorus-containing compound onto unsaturated anhydride and then reacting with a secondary amine compound, and finally, unsaturated double bonds are introduced into the flame retardant to obtain the ultraviolet curing halogen-free flame retardant. The preparation process of the flame retardant is simple, no solvent is needed, the prepared product does not need post-treatment, and the prepared solder resist ink shows excellent flame retardance, adhesive force, pencil hardness, acid and alkali resistance and heat resistance.

Description

Technical Field

[0001] The invention relates to the technical field of printing materials, and in particular to an ultraviolet light-curable halogen-free flame retardant, a solder resist ink containing the flame retardant, and applications thereof. Background Art

[0002] Printed circuit boards (PCBs) are the substrates for installing and connecting various electronic components in modern electronic devices. They are the largest industry in the electronics industry and are mainly used in aerospace, military, mobile communications, laptops, computer peripherals, PDAs, digital cameras and other products.

[0003] In order to ensure the insulation of electrical components during welding and to protect electronic products from changes in the external environment during use, a permanent protective layer, namely solder resist ink or solder mask ink, needs to be applied on the surface of the printed circuit board (PCB). Solder resist ink can prevent short circuits when welding various components, and can also adjust the amount of solder adhesion, ultimately achieving the purpose of reducing the weight of the device and increasing insulation. However, when welding components, the temperature is often high, which poses a safety hazard, so solder resist ink also needs to have good flame retardant properties.

[0004] The simplest way to improve the flame retardancy of solder mask ink is to add additive flame retardants to the ink, which does not have a long-term flame retardant effect and easily leads to a decrease in the ink's own performance after curing. Reactive flame retardants can provide better flame retardancy at a lower addition amount, but they often have a negative impact on the heat resistance of the material, and the preparation process is complicated and the cost is high. Summary of the invention

[0005] In view of the deficiencies of the prior art, the present invention provides a UV-curable halogen-free flame retardant, a solder resist ink containing the flame retardant, and applications. The present invention introduces a phosphorus-containing compound into an unsaturated acid anhydride, and then reacts with a secondary amine compound to obtain a phosphorus-nitrogen synergistic flame retardant, and finally introduces an unsaturated double bond into the flame retardant to obtain a UV-curable halogen-free flame retardant. The preparation process of the flame retardant is simple, and the prepared product does not need to be post-treated. The prepared solder resist ink has excellent flame retardancy, heat resistance, adhesion, acid and alkali resistance, and high pencil hardness, and can meet the needs of solder resist ink.

[0006] The technical solution of the present invention is as follows:

[0007] The first aspect of the present invention provides a UV-curable halogen-free flame retardant, the general structural formula of the UV-curable halogen-free flame retardant is shown in the following formula (I):

[0008]

[0009] in:

[0010] The A is selected from At least one of; said B is selected from At least one of; wherein D is a hydrocarbon-containing group.

[0011] Preferably, D is selected from At least one of .

[0012] The second aspect of the present invention provides a method for preparing the UV-curable halogen-free flame retardant according to the first aspect, comprising the following steps:

[0013] (1) dissolving a phosphorus-containing monomer, an unsaturated acid anhydride and a secondary amine monomer in an organic solvent in sequence, first stirring and reacting at 40-90° C. for 0.5-5 h, and then stirring and reacting at 60-110° C. for 2-5 h, to prepare a phosphorus-nitrogen synergistic flame retardant;

[0014] (2) adding the unsaturated group-containing monomer to the phosphorus-nitrogen synergistic flame retardant of step (1) at 60-100° C., heating for reaction, and cooling to room temperature after the reaction to obtain a UV-curable flame retardant.

[0015] Preferably, in step (1), the phosphorus-containing monomer includes at least one of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, diphenylphosphine oxide, and diphenyl phosphite;

[0016] And / or, the unsaturated acid anhydride includes one or more of itaconic anhydride, maleic anhydride, and allylsuccinic anhydride;

[0017] And / or, the secondary amine monomer includes at least one of piperazine, 2-ethylpiperazine, 2-methylpiperazine, 2,3-dimethylpiperazine, 2,5-dimethylpiperazine, and N,N-diethylethylenediamine;

[0018] The molar ratio of the phosphorus-containing monomer, the unsaturated acid anhydride and the secondary amine monomer is 2-2.5:2:1.

[0019] Preferably, in step (1), the organic solvent comprises at least one of toluene, xylene, N,N-dimethylformamide, N,N-dimethylacetamide, 1,4-dioxane, diethylene glycol methyl ether and dimethyl sulfoxide.

[0020] Preferably, in step (2), the monomer containing an unsaturated group includes at least one of glycidyl methacrylate, glycidyl acrylate, glycidyl oleate, 1,2-epoxy-5-hexene, 1,3-butadiene monoepoxide, allyl glycidyl ether, 1,2-epoxy-7-octene, 3-(allyloxy)oxetane, and 1,2-epoxy-9-decene;

[0021] and / or, the molar ratio of the phosphorus-nitrogen synergistic flame retardant to the unsaturated group-containing monomer is 1:2-2.2;

[0022] And / or, the heating reaction temperature is 80-120° C. and the time is 2-10 h.

[0023] The third aspect of the present invention provides a solder resist ink, comprising a UV-curable flame retardant and other components, wherein the other components, by mass percentage, comprise the following raw material components: 30-55% base resin, 2-25% active monomer, 1-8% photoinitiator, 1-5% color paste, 5-40% filler, and 1-5% additive;

[0024] The mass ratio of the ultraviolet light curing flame retardant to the other components is 3-5:100.

[0025] The UV-curable flame retardant is the UV-curable halogen-free flame retardant described in the first aspect, or the UV-curable halogen-free flame retardant prepared by the preparation method described in the second aspect.

[0026] Preferably, the base resin is obtained by mixing acrylate-modified phenolic epoxy resin and β-hydroxyethyl acrylate-modified melamine formaldehyde resin, and the weight ratio of the acrylate-modified phenolic epoxy resin to the β-hydroxyethyl acrylate-modified melamine formaldehyde resin is 4 to 1:1.

[0027] The active monomers include one or more of trimethylolpropane triacrylate, β-hydroxyethyl methacrylate, tripropylene glycol diacrylate, and pentaerythritol triacrylate;

[0028] The photoinitiator includes one or more of 2-ethylanthraquinone, benzoin diethyl ether 651, (2,4,6-trimethylbenzoyl)diphenylphosphine oxide, and 2-methyl 1-[4-(methylthio)phenyl]-2-morpholinyl-1-propanone;

[0029] The color paste is prepared by mixing, dispersing and grinding the pigment, resin and dispersant in a weight ratio of 1-3:7-9:0.01-0.05;

[0030] Wherein, the resin is the same as the matrix resin; the dispersant includes at least one of polyacrylate and polyamide modified polymer carboxylate dispersants;

[0031] The filler includes one or more of silicon dioxide powder, talcum powder, fumed silica, and barium sulfate;

[0032] The auxiliary agent includes one or both of a defoamer and a leveling agent.

[0033] A fourth aspect of the present invention provides a method for preparing the solder resist ink described in the third aspect, the method comprising the following steps:

[0034] S1: According to the ratio of each raw material, the base resin, active monomer, UV-curable flame retardant, photoinitiator, color paste and filler are mixed in sequence, and mixed evenly at 1300-1800r / min;

[0035] S2: Grind the mixed materials in step S1 to a fineness of less than 8 μm, then add additives and mix well;

[0036] S3: testing the material uniformly mixed in step S2. After passing the test, adjusting the viscosity to 100 Pa·s with an active monomer, filtering, and obtaining a solder resist ink;

[0037] In step S1, the base resin is obtained by mixing acrylic acid-modified phenolic epoxy resin and β-hydroxyethyl acrylate-modified melamine formaldehyde resin at a speed of 600 to 1200 r / min.

[0038] A fifth aspect of the present invention provides an application of the solder resist ink described in the third aspect, or the solder resist ink prepared by the preparation method described in the fourth aspect, wherein the solder resist ink is used to prepare a solder resist coating.

[0039] The beneficial technical effects of the present invention are:

[0040] The present invention introduces a phosphorus-containing compound into an unsaturated acid anhydride, and then reacts with a secondary amine compound to obtain a phosphorus-nitrogen synergistic flame retardant, and finally introduces an unsaturated double bond into the flame retardant to obtain a UV-curable halogen-free flame retardant. The flame retardant has high phosphorus and nitrogen content and has excellent condensed phase and gas phase flame retardant effects; the double bonds contained can participate in the curing of the ink, and will not cause the flame retardant function to fail due to migration or volatilization, and can achieve long-term flame retardancy, and as a reactive flame retardant, it will not affect the comprehensive performance of the ink itself; the synthesis method of the flame retardant is simple and green, with low viscosity and good processing technology. In summary, using it to modify solder resist ink can improve the flame retardant properties of solder resist ink.

[0041] The invention generates no waste during the preparation process, and the post-processing is convenient or unnecessary, and the production process is green, environmentally friendly, simple and efficient.

[0042] The solder resist ink prepared by the invention has excellent flame retardant performance, and also has excellent adhesion, pencil hardness, acid and alkali resistance and heat resistance. DETAILED DESCRIPTION

[0043] The present invention will be described in detail below in conjunction with the embodiments.

[0044] It is understandable that the structure of the halogen-free flame retardant of the present invention includes a phosphorus-containing structure and a nitrogen-containing structure with excellent flame retardant properties, as well as an unsaturated double bond structure that can participate in ultraviolet light curing. Among them, both flame retardant structures can respond quickly when the ink burns, and quickly decompose to produce phosphorus-containing free radicals, phosphoric acid substances and nitrogen-containing gases, which respectively play the role of quenching free radicals, promoting carbonization of the matrix, and diluting heat and combustible gases, thereby providing good flame retardant properties for solder mask ink. In addition, the phosphorus-containing structure on the pendant side group will not affect the thermal properties of the main chain. The unsaturated double bond structure is highly active and can participate in the photo-crosslinking of the ink matrix resin under ultraviolet light, and will not reduce the final mechanical properties and crosslinking density of the ink, thereby ensuring that the cured ink has high pencil hardness and good solvent resistance.

[0045] In some embodiments, in the solder resist ink, the auxiliary agents are a defoamer and a leveling agent; wherein the defoamer is a defoamer containing an organic silicon group or a silicone; and the leveling agent is a silicone-containing leveling agent.

[0046] In some embodiments, the ink includes a UV-curable flame retardant and other components, wherein the content of the base resin in the other components is preferably 35-50wt%; the content of the active monomer is preferably 6-10wt%; the content of the photoinitiator is preferably 2-5wt%; the content of the color paste is preferably 2-4wt%; and the composition of the filler is preferably 15-40wt%.

[0047] In some embodiments, the preparation method of the solder resist ink is as follows:

[0048] (1) Mixing the matrix resin: adding the acrylic acid-modified phenolic epoxy resin and the β-hydroxyethyl acrylate-modified melamine formaldehyde resin into a dispersion tank at a mass ratio of 4-1:1, and mixing the two resins uniformly at 600-1200 r / min using a high-speed disperser;

[0049] (2) Preparing color paste: adding pigment: resin: dispersant in a weight ratio of 1-3:7-9:0.01-0.05 into a dispersion tank, and mixing the color paste evenly with a high-speed disperser at 800-1500 r / min; wherein the composition of the resin is the same as that of the base resin;

[0050] (3) Material mixing: Add the base resin, active monomer, UV-curable flame retardant, photoinitiator, color paste, and filler into a dispersion tank in order according to the mass fraction and mix them using a high-speed disperser at 1300-1800 r / min;

[0051] (4) Grinding: Grind the mixed material in step (3) three times using a three-roll grinder until the ink fineness is less than 8 μm, then add a defoamer and a leveling agent and mix well;

[0052] (5) Filtration: The printing performance and heat resistance of the material mixed in step (4) are tested. After the test, the viscosity of the ink is adjusted to 100 Pa·s with an active monomer and filtered with a 200-mesh filter to finally obtain a flame-retardant and high-temperature resistant UV-curable solder resist ink.

[0053] It is understandable that the solder resist ink is applied to the printed circuit board by screen printing to form a solder resist coating, and then exposed to ultraviolet light, developed, and photocured.

[0054] The present invention will be further described below by way of examples and the like.

[0055] Embodiment 1:

[0056] A UV-curable halogen-free flame retardant, the structural formula of which is shown in the following formula (1):

[0057]

[0058] The preparation method of the above-mentioned UV-curable halogen-free flame retardant comprises the following steps:

[0059] (1) 11.2 g (0.1 mol) of itaconic anhydride, 21.6 g (0.1 mol) of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide and 4.3 g (0.05 mol) of anhydrous piperazine were dissolved in a single-necked flask containing 51.3 mL of N,N-dimethylformamide, and the mixture was reacted at 60 ° C for 8 h under condensation reflux conditions to obtain a phosphorus-nitrogen synergistic flame retardant.

[0060] (2) After the reaction in step (1) is completed, 14.2 g (0.1 mol) of glycidyl methacrylate is directly added to the mixture in step (1), and the reaction is continued at 90° C. for 10 h. After the reaction is completed, the mixture is cooled to room temperature to obtain a UV-curable halogen-free flame retardant.

[0061] Embodiment 2:

[0062] A UV-curable halogen-free flame retardant, the structural formula of which is shown in the following formula (2):

[0063]

[0064] The preparation method of the above-mentioned UV-curable halogen-free flame retardant comprises the following steps:

[0065] (1) 9.8 g (0.1 mol) of maleic anhydride, 21.6 g (0.1 mol) of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide and 4.3 g (0.05 mol) of anhydrous piperazine were dissolved in a single-necked flask containing 45.5 mL of N,N-dimethylacetamide, and the mixture was reacted at 80° C. for 8 h under condensation reflux conditions to obtain phosphoric anhydride.

[0066] (2) After the reaction of step (1) is completed, 9.8 g (0.1 mol) of 1,2-epoxy-5-hexene is directly added to step (1), and the reaction is continued at 90° C. for 10 h. After the reaction is completed, the mixture is cooled to room temperature to obtain a UV-curable halogen-free flame retardant.

[0067] Embodiment 3:

[0068] A UV-curable halogen-free flame retardant, the structural formula of which is shown in the following formula (3):

[0069]

[0070] The preparation method of the above-mentioned UV-curable halogen-free flame retardant comprises the following steps:

[0071] (1) 11.2 g (0.1 mol) of itaconic anhydride, 20.2 g (0.1 mol) of diphenylphosphine oxide and 4.3 g (0.05 mol) of anhydrous piperazine were dissolved in a single-necked flask containing 47.1 mL of N,N-dimethylformamide, and reacted at 60° C. for 3 h under condensation reflux conditions to obtain a phosphorus-nitrogen synergistic flame retardant;

[0072] (2) After the reaction in step (1) is completed, 11.4 g (0.1 mol) of allyl glycidyl ether is directly added to the mixture in step (1), and the reaction is continued at 90° C. for 10 h. After the reaction is completed, the mixture is cooled to room temperature to obtain a UV-curable halogen-free flame retardant.

[0073] Embodiment 4:

[0074] A UV-curable halogen-free flame retardant, the structural formula of which is shown in the following formula (4):

[0075]

[0076] The preparation method of the above-mentioned UV-curable halogen-free flame retardant comprises the following steps:

[0077] (1) 14.0 g (0.1 mol) of allyl succinic anhydride, 20.2 g (0.1 mol) of diphenyl phosphine oxide and 5.8 g (0.05 mol) of N,N-diethylethylenediamine were dissolved in a single-necked flask containing 49.8 mL of diethylene glycol methyl ether, and the mixture was reacted at 50° C. for 3 h under condensation reflux conditions, then the temperature was raised to 90° C. and the reaction was continued for 4 h to obtain a nitrogen synergistic flame retardant;

[0078] (2) After the reaction of step (1) is completed, 9.8 g (0.1 mol) of 1,2-epoxy-5-hexene is directly added to step (1), and the reaction is continued at 90° C. for 10 h. After the reaction is completed, the mixture is cooled to room temperature to obtain a UV-curable halogen-free flame retardant.

[0079] Embodiment 5:

[0080] A UV-curable halogen-free flame retardant, the structural formula of which is shown in the following formula (5):

[0081]

[0082] The preparation method of the above-mentioned UV-curable halogen-free flame retardant comprises the following steps:

[0083] (1) 11.2 g (0.1 mol) of itaconic anhydride, 23.4 g (0.1 mol) of diphenyl phosphite and 4.3 g of anhydrous piperazine were dissolved in a single-necked flask filled with 22.4 mL of xylene, and the mixture was reacted at 60° C. for 8 h under condensation reflux conditions to obtain a phosphorus-nitrogen synergistic flame retardant;

[0084] (2) After the reaction in step (1) is completed, 14.2 g (0.1 mol) of glycidyl methacrylate is directly added to the mixture in step (1), and the reaction is continued at 90° C. for 10 h. After the reaction is completed, the mixture is cooled to room temperature to obtain a UV-curable halogen-free flame retardant.

[0085] Comparative Example 1:

[0086] A UV-curable halogen-free flame retardant, the structural formula of which is shown in the following formula (D1):

[0087]

[0088] The preparation method of the above-mentioned UV-curable halogen-free flame retardant comprises the following steps:

[0089] (1) dissolving 13.0 g of itaconic anhydride and 21.6 g of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide in a single-necked flask containing 51.3 mL of N,N-dimethylformamide, and reacting at 90° C. for 5 h under condensation reflux conditions to obtain phosphoric anhydride;

[0090] (2) After the reaction of step (1) is completed, 14.2 g of glycidyl methacrylate is directly added to the mixture of step (1), and the reaction is continued at 90° C. for 10 h. After the reaction is completed, the mixture is cooled to room temperature to obtain a UV-curable halogen-free flame retardant.

[0091] Comparative Example 2:

[0092] A UV-curable halogen-free flame retardant, the structural formula of which is shown in the following formula (D2):

[0093]

[0094] The preparation method of the above-mentioned UV-curable halogen-free flame retardant comprises the following steps:

[0095] (1) 11.2 g (0.1 mol) of itaconic anhydride, 11.0 g (0.1 mol) of dimethyl phosphite and 4.3 g (0.05 mol) of anhydrous piperazine were dissolved in a single-necked flask containing 22.4 mL of 1,4-dioxane, and the mixture was reacted at 60° C. for 8 h under condensation reflux conditions to obtain a phosphorus-nitrogen synergistic flame retardant;

[0096] (2) After the reaction in step (1) is completed, 14.2 g (0.1 mol) of glycidyl methacrylate is directly added to the mixture in step (1), and the reaction is continued at 90° C. for 10 h. After the reaction is completed, the mixture is cooled to room temperature to obtain a UV-curable halogen-free flame retardant.

[0097] Comparative Example 3:

[0098] A UV-curable halogen-free flame retardant, the structural formula of which is shown in the following formula (D3):

[0099]

[0100] The preparation method of the above-mentioned UV-curable halogen-free flame retardant comprises the following steps:

[0101] (1) 11.2 g (0.1 mol) of itaconic anhydride, 13.8 g (0.1 mol) of diethyl phosphite and 4.3 g (0.05 mol) of anhydrous piperazine were dissolved in a single-necked flask filled with 22.4 mL of toluene, and the mixture was reacted at 60° C. for 8 h under condensation reflux conditions to obtain a phosphorus-nitrogen synergistic flame retardant;

[0102] (2) After the reaction in step (1) is completed, 14.2 g (0.1 mol) of glycidyl methacrylate is directly added to the mixture in step (1), and the reaction is continued at 90° C. for 10 h. After the reaction is completed, the mixture is cooled to room temperature to obtain a UV-curable halogen-free flame retardant.

[0103] When using the UV-curable halogen-free flame retardant obtained by Example 1, Example 2, Example 3, Example 4 and Example 5, it can be determined whether to perform post-treatment according to the process requirements during use. The specific post-treatment process is to remove the solvent in the product by reduced pressure distillation. No solvent was removed in the embodiments of the present invention. However, it is understandable that in the laboratory stage test, it was found that the flame retardant performance would be better after removing the solvent, but at the same addition amount, the flame retardant without solvent removal also has the same excellent flame retardant performance.

[0104] Application Examples 1-5

[0105] Application Examples 1-5 provide an ink, respectively, including the flame retardant and other components prepared in Example 1, and the masses of the flame retardant and other components and the raw materials and their mass fractions in the other components are shown in Table 1. Taking Application Example 2 as an example, the ink of Application Example 2 contains 5g of flame retardant, 100g of other components, and 100g of other components, by mass percentage, include 50% base resin (in the base resin, the mass ratio of acrylic acid modified phenolic epoxy resin to β-hydroxyethyl acrylate modified melamine formaldehyde resin is 4:1), 10% active monomer, 4% photoinitiator, 3.4% color paste, 32% filler, 0.3 defoamer, and 0.3 leveling agent.

[0106] The base resin is obtained by mixing acrylate-modified phenolic epoxy resin and β-hydroxyethyl acrylate-modified melamine formaldehyde resin according to the proportion in Table 1, and stirring and mixing at 800 r / min; the color paste is obtained by mixing, dispersing and grinding 20wt% of pigment, 79.5wt% of base resin and 0.5wt% of dispersant, and the filler is silicon dioxide powder; the photoinitiator is 2-ethyl anthraquinone; the active monomer is trimethylolpropane triacrylate; the defoamer is a silicone-containing defoamer; and the leveling agent is a silicone-containing leveling agent.

[0107] The preparation method of the above ink is:

[0108] S1: According to Table 1, the base resin, active monomer, flame retardant of Example 1, photoinitiator, color paste and filler are mixed in sequence and mixed evenly at 1500 r / min;

[0109] S2: Grind the mixed materials in step S1 to a fineness of less than 8 μm, then add additives and mix well;

[0110] S3: Testing the materials uniformly mixed in step S2. After passing the test, adjusting the viscosity to 100 Pa·s with active monomers, filtering, and obtaining solder resist ink.

[0111] Application Example 6-7

[0112] Application Examples 6-7 provide an ink, respectively, including the flame retardant prepared in Example 2, and the components contained therein are as shown in Table 1 (the meaning of the corresponding values ​​of each raw material in Table 1 is the same as that of Application Example 2). The model or parameter of each component is the same as that of Application Example 1.

[0113] The preparation method of the above ink is:

[0114] S1: According to Table 1, the base resin, active monomer, flame retardant of Example 2, photoinitiator, color paste and filler are mixed in sequence, and mixed evenly at 1500 r / min;

[0115] S2: Grind the mixed materials in step S1 to a fineness of less than 8 μm, then add additives and mix well;

[0116] S3: Testing the materials uniformly mixed in step S2. After passing the test, adjusting the viscosity to 100 Pa·s with active monomers, filtering, and obtaining solder resist inks of application example 6 and application example 7, respectively.

[0117] Application Examples 8-9

[0118] Application Examples 8-9 provide an ink, respectively, including the flame retardant prepared in Example 3, and the components contained therein are as shown in Table 1 (the meaning of the corresponding values ​​of each raw material in Table 1 is the same as that of Application Example 2). The model or parameter of each component is the same as that of Application Example 1.

[0119] The preparation method of the above ink is:

[0120] S1: According to Table 1, the base resin, active monomer, flame retardant of Example 3, photoinitiator, color paste and filler are mixed in sequence, and mixed evenly at 1500 r / min;

[0121] S2: Grind the mixed materials in step S1 to a fineness of less than 8 μm, then add additives and mix well;

[0122] S3: Testing the materials uniformly mixed in step S2. After passing the test, adjusting the viscosity to 100 Pa·s with active monomers, filtering, and obtaining solder resist inks of application examples 8 and 9, respectively.

[0123] Application Examples 10-11

[0124] Application Examples 10-11 provide an ink, respectively, including the flame retardant prepared in Example 4, and the components contained therein are as shown in Table 1 (the meaning of the corresponding values ​​of each raw material in Table 1 is the same as that of Application Example 2). The model or parameter of each component is the same as that of Application Example 1.

[0125] The preparation method of the above ink is:

[0126] S1: According to Table 1, the base resin, active monomer, flame retardant of Example 4, photoinitiator, color paste and filler are mixed in sequence, and mixed evenly at 1500 r / min;

[0127] S2: Grind the mixed materials in step S1 to a fineness of less than 8 μm, then add additives and mix well;

[0128] S3: Testing the materials uniformly mixed in step S2. After passing the test, adjusting the viscosity to 100 Pa·s with active monomers, filtering, and obtaining solder resist inks of application example 10 and application example 11, respectively.

[0129] Application Examples 12-13

[0130] Application Examples 12-13 provide an ink, respectively, including the flame retardant prepared in Example 5, and the components contained therein are as shown in Table 1 (the meaning of the corresponding values ​​of each raw material in Table 1 is the same as that of Application Example 2). The model or parameter of each component is the same as that of Application Example 1.

[0131] The preparation method of the above ink is:

[0132] S1: According to Table 1, the base resin, active monomer, flame retardant of Example 5, photoinitiator, color paste and filler are mixed in sequence, and mixed evenly at 1500 r / min;

[0133] S2: Grind the mixed materials in step S1 to a fineness of less than 8 μm, then add additives and mix well;

[0134] S3: Testing the materials uniformly mixed in step S2. After passing the test, adjusting the viscosity to 100 Pa·s with active monomers, filtering, and obtaining solder resist inks of application example 12 and application example 13, respectively.

[0135] Table 1 Raw materials and contents of each application example corresponding to the embodiment

[0136]

[0137] Comparative Application Examples 1-3

[0138] Comparative Application Examples 1-3 provide an ink, respectively, including the flame retardant prepared in Comparative Examples 1-3, and the proportions of the components contained therein are shown in Table 2 (the meanings of the corresponding values ​​of the raw materials in Table 1 are the same as those in Application Example 2). Among them, the base resin is obtained by mixing acrylate-modified phenolic epoxy resin and β-hydroxyethyl acrylate-modified melamine formaldehyde resin according to the proportions in Table 1, and stirring and mixing at 800r / min; the color paste is obtained by mixing, dispersing and grinding 20wt% of pigment, 79.5wt% of base resin and 0.5wt% of dispersant; the filler is silicon dioxide powder; the photoinitiator is 2-ethyl anthraquinone; the active monomer is trimethylolpropane triacrylate; the defoamer is a defoamer containing silicone; and the leveling agent is a leveling agent containing silicone.

[0139] The preparation method of the above ink is basically the same as that of Application Example 1, the only difference being that the raw materials used and the proportion of each raw material are the same as those of this comparative example.

[0140] Table 2: Raw materials and contents of the application examples corresponding to the comparative examples

[0141]

[0142] Test example:

[0143] The performance of the ink obtained from the corresponding use case and comparative application example is tested, and the test method is as follows:

[0144] ① Pencil hardness is tested according to "Determination of film hardness of paint and varnish by pencil method" GB / T6739-2006; ② Adopt HGQ type paint film scribing device and test the adhesion of coating according to GB / T9268-1998. If the coating peeling area is less than 5%, the adhesion performance is judged as ○, otherwise it is ×; ③ Temperature resistance test is to test the temperature data that the sample coated with solder resist ink can withstand after 10 seconds and three solder resistance tests according to GB / T 4677-2002; ④ Immerse the application example coating in 10vol% H2SO4 and 10wt% NaOH for 30min, rinse with water and dry. Use 3M tape (610#) to pull three times. If there is no oil loss, it means the acid and alkali resistance test is ○, otherwise it is ×; ⑤ Flame retardancy is tested according to GB / T 22472-2008: The mixed resin is prepared into 125mm×13mm×3mm specimens for vertical burning test, and the flame retardancy level of the material is divided according to the test results and referring to Table 3.

[0145] Table 3 Classification table of flame retardant test materials

[0146]

[0147] The test results are shown in the following table.

[0148] Table 4 Performance tests of various application examples and comparative application examples

[0149]

[0150] As can be seen from Table 4, the flame retardants used in Application Examples 1, 2, 3 and 5 are all flame retardants prepared in Example 1, and the addition amount is 5wt%, the only difference is the different proportion of the base resin. By changing the proportion of the base resin, it is found that the more the proportion of β-hydroxyethyl acrylate modified melamine formaldehyde resin component, the flame retardant properties of the coating are not affected, the pencil hardness of the coating is higher and the heat resistance is better. The only difference between Application Example 4 and Application Example 5 is the different addition amount of the flame retardant, and 3wt% and 5wt% of the flame retardant prepared in Example 1 are added respectively. The results show that the UL-94 grade of Application Example 4 is only V-1, while the UL-94 test grade of Application Example 5 reaches V-0, indicating that under the same formula conditions, the more the flame retardant is added, the better the flame retardant properties of the coating. The formulas and the addition amount of flame retardants in Application Examples 5, 7, 9, 11, 13, 14, 15 and 16 are the same, and the only difference is the type of flame retardant. Among them, the layers obtained in Application Examples 5, 7, 9, 11 and 13 have good flame retardant properties, and the UL-94 test reaches the V-0 level, while the flame retardant properties of Application Examples 14, 15 and 16 are poor, and the UL-94 test can only reach the V-2 level. This is because the flame retardants used in Application Examples 5, 7, 9 and 11 contain both phosphorus-containing structures and nitrogen-containing structures. The phosphorus-containing structure will decompose during combustion to produce phosphorus oxygen free radicals that can quench combustible free radicals, and the phosphoric acid substances produced by the decomposition can promote the dehydration of the matrix into carbon. In addition, the non-flammable nitrogen-containing gas produced by the decomposition of the nitrogen-containing structure can dilute the combustible free radicals and oxygen, and the benzene ring structure can also provide a large number of graphitized carbon layers. Although the phosphorus-containing structure in the flame retardant used in Application Example 13 produces fewer phosphorus-containing free radicals when decomposed during combustion, it can provide a large number of aromatic structures as high-quality carbon sources. Therefore, the coatings of Application Examples 5, 7, 9, 11 and 13 all have good flame retardant properties. In contrast, the flame retardant used in the coating in Comparative Application Example 1 does not contain nitrogen, so the gas phase effect in the flame retardant process is lacking, so the flame retardant effect is not significant. The flame retardant properties of the coatings in Comparative Application Examples 2 and 3 are poor, which is mainly due to the fact that the phosphorus element in dimethyl phosphite and diethyl phosphite only plays a role in the condensed phase of the combustion process, the gas phase effect is not significant, and the carbon source provided by the two phosphorus-containing monomers is insufficient, so it cannot provide good flame retardant properties; in addition, the decomposition temperature of these two monomers is lower, the rigid structure in the molecule is less, and the heat resistance is poor, and thus it cannot provide good comprehensive performance. In summary, the flame retardant prepared by combining a phosphorus-containing structure with an aromatic group and a nitrogen-containing structure can provide the best flame retardant performance, indicating that the synergistic effect of phosphorus and nitrogen elements in the flame retardant process can more effectively improve the flame retardant properties of the coating.

[0151] The invention prepares a UV-curable halogen-free flame retardant through a low-cost and simple process, which can provide good flame retardant properties required for welding to solder resist ink while also ensuring good processing properties and heat resistance.

[0152] The above is only a preferred embodiment of the present invention, and the present invention is not limited to the above embodiments. It is understood that other improvements and changes directly derived or associated by those skilled in the art without departing from the spirit and concept of the present invention should be considered to be included in the protection scope of the present invention.

Claims

1. A UV-curable halogen-free flame retardant, characterized in that: The general structural formula of the UV-curable halogen-free flame retardant is shown in the following formula (I): in: The A is selected from At least one of; said B is selected from At least one of; wherein D is a hydrocarbon-containing group.

2. The UV-curable halogen-free flame retardant according to claim 1, characterized in that: The D is selected from At least one of .

3. A method for preparing the UV-curable halogen-free flame retardant according to any one of claims 1 to 2, characterized in that: The steps include: (1) dissolving a phosphorus-containing monomer, an unsaturated acid anhydride and a secondary amine monomer in an organic solvent in sequence, first stirring and reacting at 40-90° C. for 0.5-5 h, and then stirring and reacting at 60-110° C. for 2-5 h, to prepare a phosphorus-nitrogen synergistic flame retardant; (2) adding the unsaturated group-containing monomer to the phosphorus-nitrogen synergistic flame retardant of step (1) at 60-100° C., heating for reaction, and cooling to room temperature after the reaction to obtain a UV-curable flame retardant.

4. The preparation method according to claim 3, characterized in that: In step (1), the phosphorus-containing monomer includes at least one of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, diphenylphosphine oxide, and diphenyl phosphite; And / or, the unsaturated acid anhydride includes one or more of itaconic anhydride, maleic anhydride, and allylsuccinic anhydride; And / or, the secondary amine monomer includes at least one of piperazine, 2-ethylpiperazine, 2-methylpiperazine, 2,3-dimethylpiperazine, 2,5-dimethylpiperazine, and N,N-diethylethylenediamine; The molar ratio of the phosphorus-containing monomer, the unsaturated acid anhydride and the secondary amine monomer is 2-2.5:2:

1.

5. The preparation method according to claim 3, characterized in that: In step (1), the organic solvent includes at least one of toluene, xylene, N,N-dimethylformamide, N,N-dimethylacetamide, 1,4-dioxane, diethylene glycol methyl ether, and dimethyl sulfoxide.

6. The preparation method according to claim 3, characterized in that: In step (2), the monomer containing an unsaturated group includes at least one of glycidyl methacrylate, glycidyl acrylate, glycidyl oleate, 1,2-epoxy-5-hexene, 1,3-butadiene monoepoxide, allyl glycidyl ether, 1,2-epoxy-7-octene, 3-(allyloxy)oxetane, and 1,2-epoxy-9-decene; and / or, the molar ratio of the phosphorus-nitrogen synergistic flame retardant to the unsaturated group-containing monomer is 1:2-2.2; And / or, the heating reaction temperature is 80-120° C. and the time is 2-10 h.

7. A solder resist ink, characterized in that: It includes ultraviolet curing flame retardant and other components, and the other components, by mass percentage, include the following raw material components: 30-55% base resin, 2-25% active monomer, 1-8% photoinitiator, 1-5% color paste, 5-40% filler, 1-5% auxiliary agent; The UV-curable flame retardant is the UV-curable halogen-free flame retardant according to any one of claims 1 to 2, or the UV-curable halogen-free flame retardant prepared by the preparation method according to any one of claims 3 to 6; The mass ratio of the ultraviolet curing flame retardant to the other components is 3-5:

100.

8. The solder resist ink according to claim 7, characterized in that: The matrix resin includes at least one of acrylate-modified phenolic epoxy resin and β-hydroxyethyl acrylate-modified melamine formaldehyde resin. Preferably, the matrix resin is obtained by mixing acrylate-modified phenolic epoxy resin and β-hydroxyethyl acrylate-modified melamine formaldehyde resin. More preferably, the weight ratio of the acrylate-modified phenolic epoxy resin to the β-hydroxyethyl acrylate-modified melamine formaldehyde resin is 4-1:

1. The active monomers include one or more of trimethylolpropane triacrylate, β-hydroxyethyl methacrylate, tripropylene glycol diacrylate, and pentaerythritol triacrylate; The photoinitiator includes one or more of 2-ethylanthraquinone, benzoin diethyl ether 651, (2,4,6-trimethylbenzoyl)diphenylphosphine oxide, and 2-methyl 1-[4-(methylthio)phenyl]-2-morpholinyl-1-propanone; The color paste is prepared by mixing, dispersing and grinding the pigment, resin and dispersant in a weight ratio of 1-3:7-9:0.01-0.05; Wherein, the resin is the same as the matrix resin; the dispersant includes at least one of polyacrylate and polyamide modified polymer carboxylate dispersants; The filler includes one or more of silicon dioxide powder, talcum powder, fumed silica, and barium sulfate; The auxiliary agent includes one or both of a defoamer and a leveling agent.

9. A method for preparing the solder resist ink according to any one of claims 7 to 8, characterized in that: The preparation method comprises the following steps: S1: According to the ratio of each raw material, the base resin, active monomer, UV-curable flame retardant, photoinitiator, color paste and filler are mixed in sequence, and mixed evenly at 1300-1800r / min; S2: Grind the mixed material in step S1 to a fineness of less than 8 μm, then add additives and mix well; S3: testing the material uniformly mixed in step S2. After passing the test, adjusting the viscosity to 100 Pa·s with an active monomer, filtering, and obtaining a solder resist ink; In step S1, the base resin is obtained by mixing acrylic acid-modified phenolic epoxy resin and β-hydroxyethyl acrylate-modified melamine formaldehyde resin at a speed of 600-1200 r / min.

10. An application of the solder resist ink according to any one of claims 7 to 8, or the solder resist ink prepared by the preparation method according to claim 9, characterized in that: The solder resist ink is used for preparing a solder resist coating.

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