CN115160919B - Outdoor super-weather-resistant water-based photocuring wood coating and preparation method thereof - Google Patents

Abstract

The invention discloses an outdoor water-based photo-curing wood coating and a preparation method thereof, belonging to the field of coatings. Adding water-based light-cured resin and fluorine-containing acrylic emulsion into a paint mixing kettle, and uniformly stirring; adding a photoinitiator, a water-based UV monomer, a hydroxytriazine derivative, dipropylene glycol methyl ether, propylene glycol, a base material wetting agent, a defoaming agent, a leveling agent, a pH regulator and water into a batching kettle to obtain a dispersed auxiliary agent mixed solution; and uniformly mixing the dispersed auxiliary agent mixed solution, the polymer modified nano silica sol and the isothiazolinone sterilizing and mildew preventing agent again, adding the associative polyurethane thickener to adjust the viscosity of the system to 60-100 KU after uniformly mixing, and filtering and discharging to obtain the outdoor super weather-resistant water-based photocuring wood coating. The outdoor wood coating with the characteristics of high hardness, high flexibility, super stain resistance, wear resistance, water resistance and chemical resistance is prepared.

Description

Outdoor super-weather-resistant water-based photocuring wood coating and preparation method thereof

Technical Field

The invention relates to an ultraviolet light curing coating, in particular to an outdoor water-based light curing wood coating with super weather resistance and a preparation method thereof.

Background

With the increasing awareness of consumer environmental protection, the demand for non-solvent coatings by furniture manufacturers is increasing. In addition, in recent years, the VOC emission limit is more and more strict, and more coating enterprises begin to consider using environment-friendly paint to replace the traditional high-VOC paint. The water-based UV coating well combines the advantages of the water-based coating and the UV light-cured coating, and becomes a popular research direction in the current coating industry. On the one hand, compared with the traditional UV paint, the water-based UV paint effectively controls the use of the reactive diluent, reduces the damage of the painting process to human bodies, and simultaneously solves the problems of curing shrinkage, large smell and the like of the traditional UV paint. On the other hand, the aqueous UV paint has excellent film coating performance compared with the conventional aqueous paint, and the drying time and the coating interval are greatly shortened.

The service life of the existing outdoor wood coating on the market is basically 1-2 years, and the defects of cracking, yellowing, foaming and the like of different degrees can occur beyond the service life, and the existing outdoor wood coating is not resistant to dirt, scratch and scratch, and the problems of film light loss, paint layer falling and the like caused by repeated external erosion are endless, so that a great amount of manpower, material resources and time are required for repairing again. Therefore, it is very necessary to provide an aqueous photocurable outdoor coating material which can be used outdoors for a long period of time and is excellent in various properties.

The contradiction between hardness and flexibility is a difficult problem that plagues conventional photocurable coatings. For many application occasions, especially outdoor application occasions with large day and night temperature difference and many corrosive mediums, the high-hardness, high-toughness and high-vapor shielding effect are achieved, and it is necessary to obtain a longer protection period for the photo-curing coating. The high hardness and the high crosslinking density can strengthen the invasion resistance of the paint film to mechanical force and chemical medium, and the high flexibility can adapt to the expansion or contraction of the base material (wood) caused by humidity or temperature change and the deformation of the soft base material. At present, a great deal of research has been devoted to optimizing the photocurable coating system, and modification of the photocurable coating with functional polymers and inorganic hybrid components is an effective approach to solve this problem.

Disclosure of Invention

The invention aims to provide a long-acting outdoor water-based ultraviolet curing wood coating. The invention is not only green and environment-friendly, but also has the advantages of high hardness, good flexibility, good adhesive force, scratch resistance, water resistance, yellowing resistance, chemical resistance, long-acting self-cleaning and the like.

The invention also aims to provide a preparation method of the outdoor water-based light-cured coating.

The aim of the invention can be achieved by the following measures:

an outdoor super weather-resistant water-based photocuring wood coating comprises the following components in parts by weight:

in some preferred technical schemes, the coating consists of the following components in parts by weight:

the technical scheme of the invention is as follows: the water-based light-cured resin is a Zhan Xin

7177 aqueous aliphatic urethane acrylate resin, vanhua->

4616 aqueous polyurethane acrylic dispersion, european Baodi LUX220 aqueous polyurethane resin, korschment->

One or more of the UV2282 aqueous ultraviolet light curable polyurethane dispersions; the fluorine-containing acrylic emulsion is one or more of Dongfu DF-12A self-crosslinking fluorine-containing acrylic emulsion, DF-01 core-shell structure fluorine-containing acrylic emulsion, intermediate fluorine Man FEM-101 self-crosslinking fluorocarbon emulsion and standard HD-830 self-crosslinking fluorine silicon acrylic emulsion.

The technical scheme of the invention is as follows: the polymer modified nano silica sol is prepared by the following steps:

adding silica sol and water-based acrylic resin into a reactor, stirring and mixing uniformly at normal temperature, slowly dripping gamma-methacryloxypropyl trimethoxy silane, heating to 60-80 ℃, and stirring and reacting for 3-5 h. Cooling to 30-40 ℃, and adding dimethylethanolamine to regulate the pH value of the system to 8-9. Adding polycarbodiimide, and continuing stirring to react for 0.5-1 h. And cooling to room temperature, adding gamma-glycidol ether oxypropyl trimethoxy silane, uniformly stirring, filtering and discharging to obtain the polymer modified nano silica sol.

The technical scheme of the invention is as follows: the polymer modified nano silica sol comprises the following components in parts by weight:

the technical scheme of the invention is as follows: the silica sol is a mixture of a new hundred-material HA2005 acidic silica sol and a new hundred-material HN3020 neutral silica sol, and the weight ratio of the two is 1:1 to 3;

the aqueous acrylic resin is DSM Di Siman Neocryl-BT-9 aqueous alkali soluble acrylic copolymer resin; the gamma-methacryloxypropyl trimethoxysilane is a U.S. Dow Corning Z-6030 silane coupling agent; the gamma-glycidoxypropyl trimethoxysilane is COATOSILMP200 epoxy silane of Michaelk company.

The technical scheme of the invention is as follows: the photoinitiator is a mixture of 2,4,6 (trimethyl benzoyl) diphenyl phosphine oxide (TPO) and 1-hydroxy-cyclohexyl-phenyl ketone (184), and the mass ratio of the two is 1-3: 1 to 3.

The technical scheme of the invention is as follows: the aqueous UV monomer is a mixture of a low-functional group monomer and a high-functional group monomer, and the mixing ratio of the low-functional group monomer to the high-functional group monomer is 4-6: 1 to 4.

The technical scheme of the invention is as follows: the low-functional-group UV monomer is one of 2 (2-ethoxyethoxy) ethyl acrylate (EOEOEA) and polyethylene glycol diacrylate (PEG-DA); the high-functional group monomer is one of ethoxylated trimethylolpropane triacrylate (EO-TMPTA), ethoxylated pentaerythritol tetraacrylate (PPTTA) and polydipentaerythritol hexaacrylate (DPHA).

The technical scheme of the invention is as follows: the hydroxyl triazine derivative is prepared by adopting odd titanium technology

5400WB aqueous emulsion ultraviolet light absorber.

The technical scheme of the invention is as follows: the substrate wetting agent is Digao

At least one of Twin-4100, pick BYK-346 and deep bamboo SN-4727; the defoamer is->

Airex 904W、/>

FOAMEX 810、

One or more of Airex 902W; the leveling agent is->

Glide 482、DOWSIL ^TM 211SAdditive、DOWSIL ^TM At least one of 51 additives; the pH regulator is a ceramic AMP-95 multifunctional auxiliary agent; the associated polyurethane thickener is Van der Waals Vesmody U605, van der Waals Vesmody U905, and Ming Ling Germany

PUR40, germany Ming Ling->

One or more of PUR 62.

The preparation method of the outdoor super weather-resistant water-based photocuring wood coating comprises the following steps:

the first step: adding the aqueous light-cured resin and the fluorine-containing acrylic emulsion into a paint mixing kettle, and uniformly stirring; adding photoinitiator, aqueous UV monomer, hydroxy triazine derivative, dipropylene glycol methyl ether, propylene glycol, base material wetting agent, defoamer, flatting agent, pH regulator and water into a batching kettle, and pre-dispersing for 0.5-1 h at 1500-2000r/min to obtain dispersed auxiliary agent mixed solution

And a second step of: and uniformly mixing the dispersed auxiliary agent mixed solution, the polymer modified nano silica sol and the isothiazolinone sterilizing and mildew preventing agent again, adding the associative polyurethane thickener to adjust the viscosity of the system to 60-100 KU after uniformly mixing, and filtering and discharging to obtain the outdoor super weather-resistant water-based photocuring wood coating.

The invention has the beneficial effects that:

(1) Adopts a photocuring system based on fluorine and silicon dual modification: according to the invention, the fluorine-modified inorganic silicon doped outdoor wood coating with excellent performances such as high hardness, high flexibility, super-strong stain resistance, long-acting water resistance and the like is prepared by introducing the F-C bond aqueous fluorine-containing resin, the modified polymer modified nano silica sol with Si-O bond and C=C double bond into a traditional aqueous photocuring system, and initiating free radical polymerization between the aqueous oligomer and the polymer modified nano silica sol through ultraviolet exposure.

(2) Adopts a novel nano silica sol modification strategy: A. two different silica sols are used for particle size grading: the large-particle-size inorganic particles can provide better mechanical strength and chemical resistance, and the small-particle-size inorganic particles can reduce the porosity of the coating and improve the water vapor shielding effect of the coating. B. The modification strategy of the disilane is adopted: in one aspect, gamma-methacryloxypropyl trimethoxysilane is used as a modifier. The method can hydrolyze in an acidic environment to generate silanol, and is coupled with hydroxyl on the surfaces of the water-based acrylic resin and the nano silicon dioxide to promote the coating of the water-based acrylic resin on the nano silicon dioxide. And the coupling reaction introduces C=C double bonds to the surface of the nano silica sol, so that the inorganic component has the capability of being combined with the photo-curing resin under UV irradiation, and the crosslinking density of the coating is improved. On the other hand, gamma-glycidoxypropyl trimethoxysilane was used as a latent curing agent for self-crosslinking of resins. The gamma-glycidoxypropyl trimethoxysilane has a stable silane group in the water phase for a long time due to the steric hindrance of the gamma-glycidoxypropyl trimethoxysilane. However, when the coating is dried and cured, methoxy silane groups released by resin deformation can be crosslinked with a substrate, resin and nano silicon dioxide, so that the crosslinking density of the coating is improved, and the problem of incomplete curing of the coating caused by insufficient UV exposure is solved. C. And introducing polycarbodiimide to perform active carboxyl blocking. By using polycarbodiimide to seal excessive carboxyl in the resin, the hydrophilicity of the coating can be reduced, and the water resistance and chemical resistance of the paint film can be improved.

(3) Preferred photoinitiating systems and ultraviolet absorbing systems: the invention adopts 2,4,6 (trimethylbenzoyl) diphenyl phosphine oxide (ultraviolet absorption peak wavelength is 366 nm), 1-hydroxy-cyclohexyl-phenyl ketone (ultraviolet absorption peak)A value wavelength of 333 nm) is a photoinitiator,

5400WB is an ultraviolet absorber (ultraviolet absorption band is 280-315 nm). The absorption peak wave bands of the initiation system and the absorption system are not overlapped, so that the problem that the photoinitiator cannot be completely cracked into free radicals due to the offset of absorption wavelengths, and the curing is incomplete is effectively avoided. Meanwhile, the optimized ultraviolet light absorber can shield a certain amount of ultraviolet radiation, so that the yellowing resistance of the product is improved.

(4) The invention adds a certain amount of water-soluble active monomer mixture into the water-based photo-curing coating, can crosslink with the water-based oligomer after radiation curing, endows the coating with certain tensile strength and capability of preventing deformation of a base material, and greatly improves the wear resistance, water resistance and chemical resistance of the coating by a more compact coating.

Detailed Description

The present invention will be further described with reference to examples, but the scope of the present invention is not limited thereto.

The water-based light-cured resin is a Zhan Xin

7177 aqueous aliphatic urethane acrylate resin (abbreviated as UCECOAT 7177), wanhua ∈ ->

4616 aqueous polyurethane acrylic dispersion (abbreviated as UROSIN 4616), eulbodi LUX220 aqueous polyurethane resin (abbreviated as LUX 220), kesiji->

One or more of UV2282 aqueous ultraviolet light curable polyurethane dispersions (abbreviated as UV 2282); the fluorine-containing acrylic emulsion is one or more of Dongfu DF-12A self-crosslinking fluorine-containing acrylic emulsion, DF-01 core-shell structure fluorine-containing acrylic emulsion, intermediate fluorine Man FEM-101 self-crosslinking fluorocarbon emulsion and standard HD-830 self-crosslinking fluorine silicon acrylic emulsion.

In the examples: the silica sol is a mixture of a new hundred material HA2005 acidic silica sol (called HA2005 for short) and a new hundred material HN3020 neutral silica sol (called HN3020 for short), and the weight ratio of the two materials is 1:1 to 3;

the aqueous acrylic resin is DSM Di-Neocryl-BT-9 aqueous alkali soluble acrylic copolymer resin (called Neocryl BT-9 resin for short); the gamma-methacryloxypropyl trimethoxysilane is a U.S. Dow Corning Z-6030 silane coupling agent (Z-6030 silane for short); the gamma-glycidoxypropyl trimethoxysilane is COATOSILMP200 epoxy silane (MP 200 silane for short) of Michaelk company.

The technical scheme of the invention is as follows: the photoinitiator is a mixture of 2,4,6 (trimethyl benzoyl) diphenyl phosphine oxide (TPO) and 1-hydroxy-cyclohexyl-phenyl ketone (184 photoinitiator), and the mixing ratio of the two is 1:1.

the technical scheme of the invention is as follows: the aqueous UV monomer is a mixture of a low-functional group monomer and a high-functional group monomer, and the mixing ratio of the low-functional group monomer to the high-functional group monomer is 4-6: 1 to 4.

The technical scheme of the invention is as follows: the low-functional-group UV monomer is one of 2 (2-ethoxyethoxy) ethyl acrylate (EOEOEA) and polyethylene glycol diacrylate (PEG-DA); the high-functional group monomer is one of ethoxylated trimethylolpropane triacrylate (EO-TMPTA), ethoxylated pentaerythritol tetraacrylate (PPTTA) and polydipentaerythritol hexaacrylate (DPHA).

The technical scheme of the invention is as follows: the hydroxyl triazine derivative is prepared by adopting odd titanium technology

5400WB aqueous emulsion ultraviolet light absorber.

The technical scheme of the invention is as follows: the substrate wetting agent is Digao

At least one of Twin-4100, pick BYK-346 and deep bamboo SN-4727; the defoamer is->

Airex 904W、/>

FOAMEX 810、/>

One or more of Airex 902W; the leveling agent is->

Glide 482、DOWSIL ^TM 211SAdditive、DOWSIL ^TM At least one of 51 additives; the pH regulator is a ceramic AMP-95 multifunctional auxiliary agent; the associative polyurethane thickener is Van der Waals Vesmody U605 (U605), van der Waals Vesmody U905 (U905), german Ming Ling->

PUR40 (abbreviated as PUR 40), ming Ling de +.>

PUR62 (abbreviated PUR 62) may be one or more of the following.

The above listed products are commercially available products including, but not limited to, the following purchase sources:

zhanxin

7177 aqueous aliphatic urethane acrylate resin, purchased as follows:

https://coatings.specialchem.com/product/r-allnex-ucecoat-7177

Wan Hua

4616 aqueous polyurethane acrylic dispersion purchased the website as follows:

https://www.whchem.com/product2.htmlmaterials＝85

europeanism (R)

The LUX220 waterborne photocurable polyester-polyurethane resin was purchased as follows:

http://www.alberdingkresins.com/cn/products/technicaldata/cat2/solvent-free-uv-curable-dispersions/

science creation

UV2282 aqueous ultraviolet light curable polyurethane dispersions were purchased as follows:

http://www.puchem.com/detail-560.html

dongfu DF-12A self-crosslinking fluorine-containing acrylic emulsion is purchased as follows:

http://www.pvdf-feve.com/index.php/index/productsshow/id/153.html

the east fluoro DF-01 core-shell structure fluorine-containing acrylic emulsion is purchased as follows:

http://www.pvdf-feve.com/index.php/index/productsshow/id/24.html

the new baud material HA2005 acidic silica sol is purchased as follows:

http://www.88better.cn/pro.aspids＝264&sortpath＝0,1,41,&flag＝view

the new baud material HN3020 neutral silica sol was purchased as follows:

http://www.88better.cn/pro.aspids＝265&sortpath＝0,1,41,&flag＝view

DSM Dissman Neocryl-BT-9 aqueous alkali soluble acrylic copolymer resin was purchased as follows:

https://info.b2b168.com/s168-63250272.html

DOWSIL ^TM 211S Additive, purchase Web site as follows:

https://www.dow.com/zh-cn/search.htmlx11＝category&q11＝assets％7Cpages％7Cproducts&q＝211s&tab＝all

DOWSIL ^TM 51Additive, purchase website as follows:

https://www.dow.com/zh-cn/pdp.dowsil-51-additive.03119785h.html？productCatalogFlag＝1#overview

the aqueous photocurable wood coatings of examples 1-4 (material ratios are shown in Table 1) and comparative examples 1-6 were prepared as follows:

(1) Preparation of polymer modified nano silica sol:

adding silica sol and water-based acrylic resin into a reactor, stirring and mixing uniformly at normal temperature, slowly dripping gamma-methacryloxypropyl trimethoxy silane, heating to 60-80 ℃, and stirring for 3-5 h. Cooling to 30-40 ℃, and adding dimethylethanolamine to regulate the pH value of the system to 8-9. Adding polycarbodiimide, and continuing stirring to react for 0.5-1 h. And cooling to room temperature, adding gamma-glycidol ether oxypropyl trimethoxy silane, uniformly stirring, filtering and discharging to obtain the polymer modified nano silica sol.

(2) Preparation of a water-based photo-curing wood coating:

adding the aqueous light-cured resin and the fluorine-containing acrylic emulsion into a paint mixing kettle, and uniformly stirring. Adding a photoinitiator, a water-based UV monomer, a hydroxyl triazine derivative, dipropylene glycol methyl ether, propylene glycol, a base material wetting agent, a defoaming agent, a leveling agent, a pH regulator and water into a batching kettle, and pre-dispersing for 0.5-1 h at 1500-2000 r/min. And sequentially adding the dispersed auxiliary agent mixed solution, the polymer modified nano silica sol and the isothiazolinone sterilizing and mildew preventing agent into a paint mixing kettle, and uniformly stirring. And adding an association polyurethane thickener to adjust the viscosity of the system to 60-100 KU, filtering and discharging to obtain the outdoor super-weather-resistant water-based photocuring wood coating.

Table 1 the amounts (parts by mass) of the materials added in examples 1 to 4

The material ratios of comparative examples 1 to 6:

(1) Comparative example 1

70 parts by mass of the silica sol mixture (HA 2005: HN 3020: 1:1.5) in example 1 was replaced with 70 parts by mass of a large particle size silica sol of HN3020, and the remaining materials were mixed in the same proportions as in example 1.

(2) Comparative example 2

4 parts by mass of Z-6030 (gamma-methacryloxypropyl trimethoxysilane) in example 2 was replaced with 4 parts by mass of gamma-aminopropyl triethoxysilane, a coupling agent containing no double bonds, and the balance was the same as in example 2.

(3) Comparative example 3

12 parts by mass of FEM-101 fluorine-containing acrylic emulsion in example 3 was replaced with 12 parts by mass of DSM XK12 aqueous acrylic emulsion, and the remaining material ratio was the same as in example 3.

(4) Comparative example 4

2 parts by mass of the Chiguard 5400WB hydroxytriazine derivative ultraviolet light absorber in example 4 was replaced with 2 parts by mass of benzotriazole mixture ultraviolet light absorber UV-1130 (ultraviolet light absorption band is 280-400 nm), and the rest of the materials were the same as in example 4.

(5) Comparative example 5

4 parts by mass of EOEOEA monomer and 1 part by mass of PPTTA monomer in example 1 were replaced with 5 parts by mass of PPTTA monomer, and the rest of the materials were in the same proportions as in example 1.

(6) Comparative example 6

55 parts by mass of Bayhydrol UV2282 aqueous photocurable resin in example 4, 15 parts by mass of HD-830 fluorine-containing acrylic emulsion and 15 parts by mass of polymer nano-modified silica sol were replaced with 80 parts by mass of Bayhydrol UV2282 aqueous photocurable resin, and the balance was the same as in example 4.

Performance testing

Test panel manufacturing, maintenance and performance test are carried out according to the method specified in HG/T5183-2017 aqueous Ultraviolet (UV) curing wood paint and LY/T3133-2019 outdoor aqueous wood paint. The sample plate curing process comprises the following steps: drying at 50deg.C for 30min, and curing under ultraviolet high pressure mercury lamp (spectral energy distribution centered at 365nm and transmission rate of 15 m/min).

The main technical indexes of the paint are listed as follows (tables 2 and 3):

table 2 performance indices of examples 1 to 4

Note that: ^[1] the number classes 0, 1, 2, 3, 4, 5 represent respectively: none, few, small, medium, more, severe or dense; ^[2] the levels of foaming and cracking sizes S0, S1, S2, S3, S4, and S5 respectively represent: invisible under a 10-time magnifying glass, visible under a 10-time magnifying glass, normal visual, bubble less than 0.5mm (normal visual clear visual), bubble 0.5-5 mm (1 mm wide crack), bubble more than 5mm (more than 1mm wide crack); ^[3] mildew size scales S0, S1, S2, S3, S4, S5 respectively represent: no visible mildew point is visible, the mildew point is less than 1mm, the mildew point is less than 2mm, the mildew point is less than 5mm, and the mildew point is more than or equal to 5 mm.

Table 3 Performance indices of comparative examples 1 to 6

Note that: ^[1] the number classes 0, 1, 2, 3, 4, 5 represent respectively: none, few, small, medium, more, severe or dense; ^[2] the levels of foaming and cracking sizes S0, S1, S2, S3, S4, and S5 respectively represent: invisible under a 10-time magnifying glass, visible under a 10-time magnifying glass, normal visual, bubble less than 0.5mm (normal visual clear visual), bubble 0.5-5 mm (1 mm wide crack), bubble more than 5mm (more than 1mm wide crack); ^[3] mildew size scales S0, S1, S2, S3, S4, S5 respectively represent: no visible mildew point is visible, the mildew point is less than 1mm, the mildew point is less than 2mm, the mildew point is less than 5mm, and the mildew point is more than or equal to 5 mm.

The detection result shows that:

example 1 was compared with comparative example 1: the silica sol mixed solution in the polymer nano silica sol in the example 1 mainly consists of acid silica sol of 6-9nm and neutral silica sol of 20-30nm, and the whole of the silica sol mixed solution in the comparative example 1 is replaced by neutral silica sol with large particle size, so that the pH value is neutral in the modification process. However, the silane coupling agent is hydrolyzed into silanol groups under acidic or weakly acidic conditions to react with hydroxyl groups on the silica surface or on the aqueous resin surface, so that the grafting reaction in comparative example 1 is insufficient and the desired effect cannot be achieved. And because the particle size of the neutral silica sol is larger, the film after film formation is fragile and not compact, and the tensile strength, flexibility and medium resistance effect are poor. If the neutral silica sol in the comparative example 1 is replaced by the acidic silica sol, the grafting modification effect is sufficient, but the silica sol has smaller particle size, so that the formed paint film has no rigidity, poor stain resistance, scratch resistance and the like.

Example 2 was compared with comparative example 2: in comparative example 2, the double bond-containing coupling agent γ -methacryloxypropyl trimethoxysilane of example 2 was replaced with a double bond-free coupling agent γ -aminopropyl triethoxysilane, and although the silica sol could still be modified, since the modified silica sol did not contain double bonds, no crosslinking with the host oligomer occurred after uv exposure, and therefore the crosslinking density and mechanical strength of the overall coating film were reduced, and the aging resistance performance was inferior to that of example 2. Similarly, if unmodified silica sol is used for physical doping, such as: the polymer modified nano silica sol in the formulation of example 2 was completely replaced by an unmodified silica sol mixture (HA 2005: HN3020 is 1:1.5), and the test results were almost the same as those of comparative example 2, and the UV coating reinforcement could not be effectively achieved.

Example 3 was compared with comparative example 3: in comparative example 3, the fluorine-containing acrylic emulsion is replaced by the aqueous acrylic resin, and the aqueous acrylic resin lacks a C-F framework which is firm in the aqueous fluorocarbon resin, so that the coating overall performance is remarkably reduced compared with the aqueous fluorocarbon resin in weather resistance, heat resistance, cold resistance, mildew resistance, yellowing resistance and the like.

Example 4 was compared with comparative example 4: comparative example 4 ultraviolet light absorber of Hydroxytriazines derivative

5400WB was replaced with benzotriazole mixture UV absorber UV-1130. Because the absorption band of the UV-1130 ultraviolet absorber is 280-400nm, which corresponds to the ultraviolet spectrum energy with 365nm as the center, a large amount of ultraviolet rays are absorbed during curing, so that the number of free radicals generated by the photoinitiator is reduced sharply, the curing speed is affected, the curing is incomplete, and the overall performance is deviated. Most of ultraviolet absorbers absorb ultraviolet rays for decomposition during curing, so that the residual effective ultraviolet absorbers of the coating are small, but the quantity of the photosensitizer and double bonds is large, and the coating is easy to change color and yellow due to decomposition under the action of ultraviolet rays in the sunlight at the later stage.

Example 1 was compared with comparative example 5: in comparative example 5, the aqueous UV monomer mixture was replaced with a multi-functional UV monomer (PPTTA), and since the high-functional UV monomer has a large molecular weight, a fast photo-curing rate, and a high crosslinking density, the cured film has correspondingly high hardness, large brittleness, and excellent resistance. But the indexes of flexibility, impact resistance and the like of the obtained coating are reduced, and the corresponding tensile strength, elongation at break and temperature change resistance cycle are poor.

Example 4 was compared with comparative example 6: in comparative example 6, all the fluorine-containing acrylic emulsion and the polymer modified nano silica sol are replaced by the water-based photo-curing resin, namely the film forming materials in the formula are all water-based photo-curing resins. As the crosslinking density is improved, the mechanical property and chemical resistance of the coating after being cured into a film are greatly improved. Although the rigidity is enhanced, the coating has generally outdoor durability and toughness, and after the coating is deformed due to expansion or shrinkage of the substrate caused by temperature or humidity change after a certain period of time is reached outdoors, the stress structure of the coating is broken, so that the coating film can be cracked and chalked to different degrees. Meanwhile, as a large number of double bonds are arranged on the molecular chain, the film can be easily damaged under the exposure of long-time ultraviolet rays, and the generated cracked double bonds are excessively beyond the action range of the ultraviolet absorbent, so that the yellowing resistance of the film can be deteriorated. In the embodiment 4, the fluorocarbon resin and the polymer modified nano silica sol exist, so that the toughness, the tensile strength and the yellowing resistance of the whole coating are improved, and meanwhile, the hydrophobic group increases the contact angle between water and the surface of the coating, so that the self-cleaning effect is greatly improved.

Claims (9)

1. The outdoor super weather-resistant water-based photocuring wood coating is characterized by comprising the following components in parts by weight:

wherein: the polymer modified nano silica sol is prepared by the following steps:

adding silica sol and water-based acrylic resin into a reactor, stirring and mixing uniformly at normal temperature, slowly dripping gamma-methacryloxypropyl trimethoxysilane, heating to 60-80 ℃, and stirring and reacting for 3-5 h; cooling to 30-40 ℃, and adding dimethylethanolamine to adjust the pH value of the system to 8-9; adding polycarbodiimide, and continuing stirring to react for 0.5-1 h; cooling to room temperature, adding gamma-glycidol ether oxypropyl trimethoxy silane, uniformly stirring, filtering and discharging to obtain polymer modified nano silica sol;

the modified nano silica sol consists of the following components in parts by weight:

2. the outdoor super-weather-resistant water-based photocuring wood paint as set forth in claim 1, wherein the paint is composed of the following components in parts by weight:

3. an outdoor super weather-resistant aqueous photocurable wood coating as recited in claim 1 or 2, wherein said aqueous photocurable resin is a high-performance new one

7177 aqueous aliphatic urethane acrylate resin, vanhua->

4616 aqueous polyurethane acrylic dispersion, european Baodi LUX220 aqueous polyurethane resin, korschment->

One or more of the UV2282 aqueous ultraviolet light curable polyurethane dispersions;

the fluorine-containing acrylic emulsion is one or more of Dongfu DF-12A self-crosslinking fluorine-containing acrylic emulsion, DF-01 core-shell structure fluorine-containing acrylic emulsion, intermediate fluorine Man FEM-101 self-crosslinking fluorocarbon emulsion and standard HD-830 self-crosslinking fluorine silicon acrylic emulsion.

4. The polymer modified nano silica sol according to claim 1, wherein the silica sol is a mixture of a new hundred material HA2005 acidic silica sol and a new hundred material HN3020 neutral silica sol, and the weight ratio of the two is 1:1 to 3;

the aqueous acrylic resin is DSM Di Siman Neocryl-BT-9 aqueous alkali soluble acrylic copolymer resin; the gamma-methacryloxypropyl trimethoxysilane is a U.S. Dow Corning Z-6030 silane coupling agent; the gamma-glycidoxypropyl trimethoxysilane is COATOSILMP200 epoxy silane of Michaelk company.

5. An outdoor super weather-resistant water-based photocuring wood paint as claimed in claim 1 or 2, wherein the photoinitiator is a mixture of 2,4,6 (trimethyl benzoyl) diphenyl phosphine oxide (TPO) and 1-hydroxy-cyclohexyl-phenyl ketone (184), and the mass ratio of the two is 1-3: 1 to 3.

6. The outdoor super weather-resistant aqueous photocuring wood paint according to claim 1 or 2, wherein the aqueous UV monomer is a mixture of a low-functional group monomer and a high-functional group monomer, and the mixing ratio of the low-functional group monomer to the high-functional group monomer is 4-6: 1 to 4;

the low-functional-group UV monomer is one of 2 (2-ethoxyethoxy) ethyl acrylate (EOEOEA) and polyethylene glycol diacrylate (PEG-DA); the high-functional group monomer is one of ethoxylated trimethylolpropane triacrylate (EO-TMPTA), ethoxylated pentaerythritol tetraacrylate (PPTTA) and polydipentaerythritol hexaacrylate (DPHA).

7. The outdoor super weather-resistant water-based photocuring wood paint as set forth in claim 1 or 2, wherein the hydroxytriazine derivative is a titanium-based technology

5400WB aqueous emulsion ultraviolet light absorber.

8. An outdoor super weather-resistant aqueous photocuring wood paint as claimed in claim 1 or 2, wherein the substrate wetting agent is digao

At least one of Twin-4100, pick BYK-346 and deep bamboo SN-4727;

the defoamer is

Airex 904W、/>

FOAMEX 810、/>

One or more of Airex 902W;

the leveling agent is

Glide 482、DOWSIL ^TM 211S Additive、DOWSIL ^TM At least one of 51 additives;

the pH regulator is a ceramic AMP-95 multifunctional auxiliary agent;

the associated polyurethane thickener is Van der Waals Vesmody U605, van der Waals Vesmody U905, and Ming Ling Germany

PUR40, germany Ming Ling->

One or more of PUR 62.

9. A method for preparing the outdoor super weather-resistant water-based photocuring wood paint as claimed in claim 1 or 2, which is characterized by comprising the following steps:

the first step: adding the aqueous light-cured resin and the fluorine-containing acrylic emulsion into a paint mixing kettle, and uniformly stirring; adding a photoinitiator, a water-based UV monomer, a hydroxytriazine derivative, dipropylene glycol methyl ether, propylene glycol, a base material wetting agent, a defoaming agent, a leveling agent, a pH regulator and water into a batching kettle, and pre-dispersing for 0.5-1 h at 1500-2000r/min to obtain a dispersed auxiliary agent mixed solution;

and a second step of: and uniformly mixing the dispersed auxiliary agent mixed solution, the polymer modified nano silica sol and the isothiazolinone sterilizing and mildew preventing agent again, adding the associative polyurethane thickener to adjust the viscosity of the system to 60-100 KU after uniformly mixing, and filtering and discharging to obtain the outdoor super weather-resistant water-based photocuring wood coating.