CN110698974A

CN110698974A - Low-odor UV-curing three-proofing paint composition

Info

Publication number: CN110698974A
Application number: CN201910913128.XA
Authority: CN
Inventors: 陈潇健; 秦旺洋; 张呈波; 邹彪
Original assignee: According To Special Materials (suzhou) Co Ltd
Current assignee: According To Special Materials (suzhou) Co Ltd
Priority date: 2019-09-25
Filing date: 2019-09-25
Publication date: 2020-01-17

Abstract

The invention discloses a low-odor UV-curing three-proofing paint composition, which comprises the following components in parts by weight: 35-50 parts of isocyanate modified polyurethane acrylate; 5-20 parts of polyethylene glycol acrylate; 20-40 parts of an acrylate monomer; 2-6 parts of a modified photoinitiator; 0.1-1 part of a leveling agent; 0.1-1 part of defoaming agent. According to the low-odor UV-curing three-proofing paint composition, hydroxyl of the photoinitiator reacts with isocyanate groups, micromolecular photoinitiators are grafted on macromolecule side chains of the prepolymer, the smell of a coating film is reduced, the initiating effect of the photoinitiator can be improved, and a finished product is low in odor, green and environment-friendly in the curing construction process and after curing.

Description

Low-odor UV-curing three-proofing paint composition

Technical Field

The invention relates to the technical field of UV-curing conformal coating, in particular to a low-odor UV-curing conformal coating composition.

Background

One of the main types of radiation curable coatings is Ultraviolet (UV) curing technology, which has been developed in recent decades and is widely used. The origin of uv-curing technology can be traced back to the first patent relating to photocurable coatings in 1936, and especially in the last decades, the annual growth rate has been high. This technique is sought after by a wide range of researchers, and good feedback to the market, mainly relies on its excellent 5E characteristics: ecological balance (Ecological), low Energy consumption (Energy consumption), high Economic benefit (Economic), Easy operation (Easy operation), Excellent performance (Excellent refining).

With the development of society, technological advances and key advances, the electronic industry, such as printed circuit boards, has begun to apply coating materials, also commonly referred to as Conformal coating, on a large scale. Compared with the prior art that the coating is directly exposed to the external environment, the coating is protected, oxygen, dust, chemical components, mould and the like can be isolated, certain physical protection can be performed, the use stability is improved on one hand, and the service life of the electronic element is prolonged on the other hand.

The traditional coating continues the use rule of solvents in the coating industry, and often contains benzene series, which directly causes harm to human bodies, easily causes occupational diseases after long-term contact, and also has certain influence on production safety and environment. The photocureable coating solves the problem of VOC (volatile organic compounds) from the system, the micromolecule reactive diluent also participates in the reaction while acting as a solvent, a well-designed formula can reach the state of optimal conversion rate, and the volatilization of micromolecules is limited to the maximum extent.

Although the formula of the photoinitiator is less, the important component, namely alpha-hydroxy ketone, is high in cost performance and photoreaction activity, so that the photoinitiator is the most commonly used photoinitiator at present. However, during the use process, the photolysis products are generated by volatile small molecular substances such as aldehydes, ketones and the like, so that the problem of environmental pollution in the mass production process is caused, and certain damage is caused to human bodies. Therefore, a green and environment-friendly UV three-proofing paint product with low odor in the semi-finished coating and the curing construction process and the cured finished product is needed at present.

Disclosure of Invention

Aiming at the defects, the invention aims to provide the low-odor UV-curing three-proofing paint composition which is low in volatility, free of byproducts after curing and environment-friendly.

The technical scheme of the invention is summarized as follows:

the low-odor UV-curing three-proofing paint composition comprises the following components in parts by weight:

preferably, the low-odor UV-curable conformal coating composition is characterized in that the acrylate monomer is one or more selected from tetrahydrofuran methacrylate, isobornyl methacrylate, 2-phenoxyethyl acrylate, isocyanate formal acrylate, alkoxylated tetrahydrofuran acrylate, isobornyl acrylate, triethylene glycol dimethacrylate, 1, 4-butanediol dimethacrylate, diethylene glycol dimethacrylate, 1, 6-ethylene glycol diacrylate, isocyanate triacrylate and pentaerythritol tetraacrylate.

Preferably, the low-odor UV-curable conformal coating composition is obtained by modifying a modified photoinitiator through a photoinitiator, wherein the photoinitiator is one or more selected from 2-hydroxy-2-methyl-1-phenyl acetone, 1-hydroxy-cyclohexyl benzophenone, 2-hydroxy-2-methyl-1-p-hydroxyethyl ether phenyl acetone, 2,4, 6-trimethylbenzoyl-diphenyl phosphine oxide, 2-hydroxy-4' - (2-hydroxyethoxy) -2-methyl phenylpropanone, and (2,4, 6-trimethylbenzoyl) diphenyl phosphine oxide.

Preferably, the low-odor UV-curable conformal coating composition comprises the following specific preparation methods of the modified photoinitiator: mixing 2-6 parts of photoinitiator and 8-10 parts of isocyanate modified urethane acrylate, heating to 55-65 ℃, and reacting for 1-1.5 h to obtain the modified photoinitiator.

Preferably, the low-odor UV-curing conformal coating composition is prepared by mixing a leveling agent and a low-odor UV-curing conformal coating agent, wherein the leveling agent is one or more of polydimethylsilane, polymethylphenylsiloxane and polyether modified polydimethylsiloxane.

Preferably, the low-odor UV-curing three-proofing paint composition is characterized in that the defoaming agent is one or more of polydimethylsiloxane, tributyl phosphate and modified polysiloxane.

Preferably, the low-odor UV-curable three-proofing paint composition is characterized in that the viscosity of the isocyanate modified polyurethane acrylate is 10000-20000 CPS/25 degrees.

Preferably, the low-odor UV-curing three-proofing paint composition is characterized in that the viscosity of the polyethylene glycol acrylate is 4000-8000 CPS/25 degrees.

The invention has the beneficial effects that:

(1) according to the low-odor UV-curing three-proofing paint composition, hydroxyl of the photoinitiator reacts with isocyanate groups, micromolecular photoinitiators are grafted on macromolecule side chains of the prepolymer, the smell of a coating film is reduced, the initiating effect of the photoinitiator can be improved, and a finished product is low in odor, green and environment-friendly in the curing construction process and after curing.

(2) The three-proofing paint is prepared from isocyanate modified polyurethane acrylate, polyethylene glycol acrylate and an acrylate monomer under the action of a photoinitiator, and the isocyanate modified polyurethane acrylate has excellent adhesive force and good toughness; the polyethylene glycol in the polyethylene glycol acrylate has good compatibility of the polyethylene glycol structure, is used as a chain extension function in a system, is environment-friendly, and can improve the comprehensive chemical and mechanical properties of the product.

Description of the drawings:

FIG. 1 is a reaction equation for modified photoinitiator 1173;

FIG. 2 is a reaction equation for the modified photoinitiator 184;

FIG. 3 reaction equation for modified photoinitiator 2959.

Detailed Description

The present invention is further described in detail below with reference to examples so that those skilled in the art can practice the invention with reference to the description.

The invention provides a low-odor UV-curing three-proofing paint composition, which comprises the following components in parts by weight:

the viscosity of the isocyanate modified polyurethane acrylate is 10000-20000 CPS/25 degrees, the chromaticity is 5, the isocyanate modified polyurethane acrylate has excellent adhesive force and good toughness, contains isocyanate groups in a system and can react with hydroxyl in a hydroxyl ketone photoinitiator, and a prepolymer modified micromolecule photoinitiator can be used for obtaining a macromolecule odor-free photoinitiator; the viscosity of the polyethylene glycol acrylate is 4000-8000 CPS/25 degrees, the polyethylene glycol structure has good compatibility, the polyethylene glycol acrylate serves as a chain extension function in a system, the polyethylene glycol acrylate is relatively environment-friendly, and the comprehensive chemical and mechanical properties of the product can be improved.

In yet another embodiment of the present disclosure, the acrylate monomer is one or more selected from the group consisting of tetrahydrofuran methacrylate, isobomyl methacrylate, 2-phenoxyethyl acrylate, isocyanate formal acrylate, alkoxylated tetrahydrofuran acrylate, isobornyl acrylate, triethylene glycol dimethacrylate, 1, 4-butanediol dimethacrylate, diethylene glycol dimethacrylate, 1, 6-ethylene glycol diacrylate, isocyanate triacrylate, and pentaerythritol tetraacrylate.

As yet another embodiment of the present disclosure, the modified photoinitiator is obtained by modifying a photoinitiator, and the photoinitiator is selected from one or more of 2-hydroxy-2-methyl-1-phenyl acetone, 1-hydroxy-cyclohexyl benzophenone, 2-hydroxy-2-methyl-1-p-hydroxyethyl ether phenyl acetone, 2,4, 6-trimethylbenzoyl-diphenyl phosphine oxide, 2-hydroxy-4' - (2-hydroxyethoxy) -2-methyl propiophenone, and (2,4, 6-trimethylbenzoyl) diphenyl phosphine oxide.

As another embodiment of the present disclosure, the preparation method of the modified photoinitiator specifically comprises: mixing 2-6 parts of photoinitiator and 8-10 parts of isocyanate modified urethane acrylate, heating to 55-65 ℃, and reacting for 1-1.5 h to obtain the modified photoinitiator.

The photoinitiator is a compound which can absorb energy with a certain wavelength in an ultraviolet region (250-420 nm) or a visible light region (400-800 nm) to generate free radicals, cations and the like so as to initiate the polymerization, crosslinking and curing of monomers, and the photoinitiator is preferably modified 2-hydroxy-2-methyl-1-phenyl acetone, 1-hydroxy-cyclohexyl benzophenone, 2-hydroxy-2-methyl-1-p-hydroxyethyl ether phenyl acetone, 2,4, 6-trimethylbenzoyl-diphenyl phosphine oxide, 2-hydroxy-4' - (2-hydroxyethoxy) -2-methyl propiophenone, (2,4, 6-trimethylbenzoyl) diphenyl phosphine oxide, and is subjected to early modification treatment, the photoinitiator with high activity is used, the byproducts generated by residual micromolecular substances or photolysis reaction are reduced as far as possible, the photoinitiator containing hydroxyl is modified by utilizing the isocyanate oligomer, and the process is used for grafting and modifying the photoinitiator on the oligomer to inhibit the volatilization of the micromolecular substances of the photoinitiator before and after the coating is cured, so that the aim of reducing VOC is fulfilled.

The preparation method of the modified 2-hydroxy-2-methyl-1-phenyl acetone (modified 1173) comprises the following specific steps: 2 parts of 2-hydroxy-2-methyl-1-phenyl acetone and 8 parts of isocyanate modified polyurethane acrylate are added into a flask, the temperature is slowly raised to 60 ℃, and the modified photoinitiator 1173 is obtained after the reaction for 1 hour. The specific reaction equation is shown in fig. 1:

the preparation method of the modified 1-hydroxy-cyclohexyl benzophenone (184) comprises the following steps: adding 5 parts of 1-hydroxy-cyclohexyl benzophenone and 9 parts of isocyanate modified polyurethane acrylate into a flask, slowly heating to 60 ℃, and reacting for 1 hour to obtain a modified photoinitiator 184, wherein the specific reaction equation is shown in figure 2:

the preparation method of the modified 2-hydroxy-2 methyl-1-p-hydroxyethyl ether phenyl acetone (2959) comprises the following steps: taking 6 parts of 2-hydroxy-2 methyl-1-p-hydroxyethyl ether phenyl acetone and 10 parts of isocyanate modified polyurethane acrylate, adding the mixture into a flask, slowly heating to 65 ℃, and reacting for 1.5 hours to obtain a modified photoinitiator 2959, wherein the specific reaction equation is shown in figure 3:

through the reaction of hydroxyl and isocyanate, a micromolecular photoinitiator is linked on the macromolecular side of the prepolymer, the initiation effect of the photoinitiator is not influenced on the basis of reducing the smell of a coating film, the effect of different modified initiators is compared in experiments, the ratio of the photoinitiator in the system determines the speed and the curing degree of the photocuring reaction, the using amount of the photoinitiator influences the curing integrity degree of the system, and finally the performance of the coating film is influenced.

As another embodiment of the disclosure, the leveling agent is one or more of polydimethylsilane, polymethylphenylsiloxane, and polyether-modified polydimethylsiloxane. The leveling agent is a common paint assistant, can promote the paint to form a flat, smooth and uniform coating film in the drying film-forming process, can effectively reduce the surface tension of the finishing liquid, improve the leveling property and uniformity of the coating liquid, improve the permeability of the finishing liquid, reduce the possibility of generating spots and stains during brushing, increase the coverage property and enable the film to be formed uniformly and naturally.

As another embodiment of the present disclosure, the defoaming agent is one or more of polydimethylsiloxane, tributyl phosphate, and modified polysiloxane. The defoaming agent reduces the surface tension in the paint processing process, inhibits the generation of foam or eliminates the generated foam, and the preferable defoaming agent is polydimethylsiloxane, tributyl phosphate and modified polysiloxane.

Specific examples 1 to 5 are listed below as shown in Table 1:

TABLE 1

The results of the performance tests of examples 1-5 are shown in Table 2:

TABLE 2

Smell(s)

VOC

Adhesion force

Curing time

Dielectric constant

Salt fog resistance

Acid and alkali resistance

Example 1

4

1.9％

4B

30s

3.3*10¹⁴

Pass

Example 2

2

1.08

5B

28s

5.1*10¹⁴

Pass

Example 3

1

0.97％

4B

25s

4.6*10¹⁴

Pass

Example 4

1

0.88％

5B

25s

1.8*10¹⁵

Pass

Example 5

2

1.13％

5B

27s

4.4*10¹⁴

Pass

The test method comprises the following steps:

1) and (3) odor test: coating a sample on a PCB (printed Circuit Board) by a brush coating or dip coating mode, wherein the coating area is 100cm2, curing the sample by an ultraviolet curing machine, sealing the sample, and keeping the temperature at 60 ℃ for 30min according to the odor; the evaluation value is 0-5 grade, wherein the higher the grade is, the smaller the smell is, and the grade 0 shows no obvious smell; curing conditions are as follows: single lamp cure (power 1000W), lamp distance: 16 cm; the belt speed is as follows: 4 m/min.

2) VOC testing: according to ASTM D5403-94, weighing about 0.5g of sample in a container, cooling for 15min after solidification reaction, weighing again, ventilating and drying the sample at 120 +/-10 ℃ for 1 hour, cooling and weighing the ventilated and dried sample. The VOC calculation formula is as follows:

wherein A is the weight of the container, g; b is the weight of the sample plus the container, g; c is the weight of the sample and container, g, after curing and drying with aeration.

3) And (3) testing the adhesive force: adopting ASTM D3359 standard;

4) and (3) dielectric constant test: ASTM D257 standard was used;

5) salt spray resistance test: continuously spraying 5% NaCl solution for 1500h, and observing whether the surface is whitish, foamed and fallen;

6) acid resistance test: dripping 10% HCl solution on the surface of the cured coating, and staying for 20 minutes;

7) alkali resistance test: dripping 10% NaOH solution on the surface of the cured coating, and staying for 10 minutes;

while embodiments of the invention have been disclosed above, it is not limited to the applications listed in the description and the embodiments, which are fully applicable in all kinds of fields of application of the invention, and further modifications may readily be effected by those skilled in the art, so that the invention is not limited to the specific details without departing from the general concept defined by the claims and the scope of equivalents.

Claims

1. The low-odor UV-curing three-proofing paint composition is characterized in that the dye check developer comprises the following components in parts by weight:

2. the low odor UV curable tri-proof paint composition according to claim 1, wherein the acrylate monomer is selected from one or more of tetrahydrofuran methacrylate, isobornyl methacrylate, 2-phenoxyethyl acrylate, isocyanate formal acrylate, alkoxylated tetrahydrofuran acrylate, isobornyl acrylate, triethylene glycol dimethacrylate, 1, 4-butanediol dimethacrylate, diethylene glycol dimethacrylate, 1, 6-ethylene glycol diacrylate, isocyanate triacrylate, pentaerythritol tetraacrylate.

3. The low odor UV-curable lacquer composition according to claim 1, wherein the modified photoinitiator is modified by a photoinitiator selected from one or more of 2-hydroxy-2-methyl-1-phenylpropanone, 1-hydroxy-cyclohexylbenzophenone, 2-hydroxy-2-methyl-1-p-hydroxyethyl etheryl phenylpropanone, 2,4, 6-trimethylbenzoyl-diphenylphosphine oxide, 2-hydroxy-4' - (2-hydroxyethoxy) -2-methylpropiophenone, (2,4, 6-trimethylbenzoyl) diphenylphosphine oxide.

4. The low-odor UV-curable conformal coating composition according to claim 3, wherein the modified photoinitiator is prepared by a method comprising: mixing 2-6 parts of photoinitiator and 8-10 parts of isocyanate modified urethane acrylate, heating to 55-65 ℃, and reacting for 1-1.5 h to obtain the modified photoinitiator.

5. The low odor UV curable tri-proof paint composition according to claim 1, wherein the leveling agent is one or more of polydimethylsilane, polymethylphenylsiloxane, polyether modified polydimethylsiloxane.

6. The low odor UV curable tri-proof paint composition according to claim 1, wherein the defoamer is one or more of polydimethylsiloxane, tributyl phosphate, modified polysiloxane.

7. The low-odor UV-curable conformal coating composition according to claim 1, wherein the viscosity of the isocyanate-modified urethane acrylate is 10000 to 20000CPS/25 °.

8. The low odor UV-curable tri-proof paint composition according to claim 1, wherein the polyethylene glycol acrylate viscosity is 4000 to 8000CPS/25 °.