Transparent primer as well as preparation method and application thereof

Abstract

The invention relates to a transparent primer and a preparation method and application thereof.The transparent primer is composed of a component A and a component B according to the weight ratio of 100: (10-20), and the component A is composed of, by weight, 15-30 parts of UV resin; 10 to 20 parts of epoxy resin; 15-30 parts of a transparent filler; 0.5 to 3 parts of a silane coupling agent; 0.5 to 3 parts of a photoinitiator; 0.1-2 parts of a base material wetting agent; 0.1-1 part of a leveling agent; 0.2 to 2 parts of a light aging auxiliary agent; and 10-30 parts of a mixed solvent. The component B is prepared from the following raw materials in parts by weight: 70 to 90 parts of phenolic aldehyde amine curing agent; and 10 to 30 parts of butyl acetate. Compared with the prior art, the transparent primer provided by the invention has the advantages of fast drying, good filling, high strength and the like, and can be used for surface coating of a carbon fiber base material.

Description

Technical Field

[0001] The invention relates to the technical field of coatings, and in particular to a transparent primer and a preparation method and application thereof. Background Art

[0002] With the rapid development of new energy vehicles in the automotive industry, lightweight vehicles have also become one of the mainstream directions of the development of the cycling industry. Carbon fiber composite materials have extremely high strength and stiffness, and are very light. They are mainly used in body components, brake pumps, wheels, transmission shafts, power battery covers, car roofs, etc., becoming the main material for lightweight vehicles.

[0003] The preparation of carbon fiber composites mainly includes two steps: fiber preparation and composite process.

[0004] 1. Fiber preparation The preparation process of carbon fiber generally includes the following steps:

[0005] (1) Preparation of raw materials. Taking polyacrylonitrile (PAN) as an example, firstly, it is necessary to prepare the raw material polyacrylonitrile.

[0006] (2) Spinning: dissolving polyacrylonitrile in a solvent and spinning it into fibers through a spinning machine.

[0007] (3) Pre-oxidation: The spinning is pre-oxidized at a certain temperature and pressure to improve its performance.

[0008] (4) Carbonization: The pre-oxidized fibers are carbonized at high temperatures to continuously remove non-carbon elements from the fibers.

[0009] (5) Surface treatment: The carbonized fiber is subjected to surface treatment to improve its surface properties.

[0010] (6) Sizing: Sizing the surface treated fibers to protect the fibers and improve their weavability.

[0011] 2. Composite process The composite process of carbon fiber composite materials generally includes the following steps:

[0012] (1) Prepare the matrix material. Select a suitable matrix material according to the needs, such as epoxy resin, phenolic resin, etc.

[0013] (2) Impregnation: immersing the fiber fabric in the matrix material to achieve penetration and wetting of the fiber fabric by the matrix material.

[0014] (3) Curing: Curing the impregnated fiber fabric under a certain temperature and pressure to fully polymerize the matrix material.

[0015] (4) Post-processing: the cured composite material is post-processed, such as cutting, grinding, etc., to obtain the desired shape and size.

[0016] Due to the complexity and particularity of the manufacturing process, there are many defects on the surface of carbon fiber composite materials: surface porosity, high roughness, poor coating adhesion; surface fiber copying effect caused by the difference in thermal expansion coefficients between the matrix resin and carbon fiber, and depressions in the woven texture, which are difficult to fill and paint with ordinary coatings. If the carbon fiber texture effect is to be reflected, spraying transparent primer and topcoat is even more difficult, which has always been a problem in the coatings and coatings industry. Summary of the invention

[0017] The purpose of the present invention is to overcome the defects of the prior art and provide a transparent primer and its preparation method and application, which has the advantages of fast drying, good filling and high strength, and can be applied to carbon fiber substrates.

[0018] The purpose of the present invention can be achieved by the following technical solutions:

[0019] One of the technical solutions of the present invention is to provide a transparent primer, which is composed of component A and component B in a weight ratio of 100: (10-20), wherein component A is composed of the following components and raw materials in parts by weight:

[0020]

[0021] Component B is composed of the following components and raw materials in parts by weight:

[0022] 70-90 parts of phenalkamine curing agent;

[0023] Butyl acetate (BAC) 10-30 parts;

[0024] Wherein, the mixed solvent is any one of butyl acetate, propylene glycol methyl ether acetate (PMA), 100# solvent oil, and cyclohexanone (CYC) or a mixed solvent composed of several of them.

[0025] In some specific embodiments, component A is composed of the following components and raw materials in parts by weight:

[0026] 20-30 parts of UV resin, 10-15 parts of epoxy resin, 20-30 parts of transparent filler, 1-2 parts of silane coupling agent, 0.5-2 parts of photoinitiator, 0.5-1 parts of substrate wetting agent, 0.2-0.8 parts of leveling agent, 0.6-1.5 parts of light aging aid, 20-30 parts of mixed solvent;

[0027] Component B is composed of the following components and raw materials in parts by weight:

[0028] Phenolic amine curing agent 75-90 parts, solvent 20-30 parts.

[0029] In some specific embodiments, in component A, the UV resin is a UV resin of low-functionality oligomer;

[0030] The epoxy resin is a low molecular weight epoxy resin;

[0031] The transparent filler is a transparent inorganic non-metallic functional powder;

[0032] The silane coupling agent is a methoxy-containing silane coupling agent.

[0033] The UV resin uses low-functionality oligomer UV resin, which has low functionality and good toughness, is suitable for primers, and has good compatibility with other resins.

[0034] The epoxy resin is a low molecular weight epoxy resin, which has good adhesion to the matrix material in the carbon fiber substrate.

[0035] Transparent fillers are made of transparent inorganic non-metallic functional powder fillers, which are environmentally friendly new materials that do not contain crystal water and have the characteristics of high transparency, high filling, high stability and easy dispersion.

[0036] The silane coupling agent containing methoxy is selected to effectively improve the adhesion to the carbon fiber.

[0037] In some specific embodiments, the UV resin is selected from any one of ETERCURE 6185 UV resin, ETERCURE 6349 UV resin, and CF-3100A UV resin;

[0038] The epoxy resin is selected from any one of YPE-128 epoxy resin, YPE-011X75 epoxy resin, and E-1011 epoxy resin;

[0039] The transparent filler is selected from T303 filler or T312 filler;

[0040] The silane coupling agent is selected from KH-540 coupling agent or KH560 coupling agent.

[0041] In some specific embodiments, in component A, the photoinitiator is selected from any one of 184-D photoinitiator, 1173 photoinitiator, and DoubleCure 1256 photoinitiator;

[0042] The substrate wetting agent is TEGO245 substrate wetting agent;

[0043] The leveling agent is selected from BYK310 leveling agent or BYK333 leveling agent;

[0044] The photoaging aid is selected from TINUVIN 400 photoaging aid or TIANSORB 5200 photoaging aid;

[0045] In component B, the phenalkamine curing agent is CARDOLITE NX-2016 phenalkamine curing agent.

[0046] The second technical solution of the present invention is to provide a method for preparing a transparent primer as described in one of the above technical solutions, comprising the following steps:

[0047] S1. In a dark environment, add UV resin and epoxy resin to a cylinder in order, and stir at a low speed first; then add transparent filler under low-speed stirring, stir at a high speed after adding, and check that the fineness is less than 5 microns; then reduce the speed to a low speed, add silane coupling agent, photoinitiator, substrate wetting agent, leveling agent and light aging aid in sequence, and stir at a medium speed after adding; finally, add a mixed solvent to adjust the viscosity to obtain component A;

[0048] S2, dissolving the phenalkamine curing agent in butyl acetate, and stirring at a low speed to obtain component B;

[0049] S3, evenly mix component A and component B to obtain a transparent primer.

[0050] In some specific embodiments, in step S1 and step S2, the low speed is 300-500 rpm, the medium speed is 600-800 rpm, and the high speed is 1000-1500 rpm.

[0051] In some specific embodiments, in step S1 and step S2, the UV resin and the epoxy resin are stirred at a low speed for 10 to 15 minutes;

[0052] Add transparent filler and stir at high speed for 30 to 45 minutes;

[0053] Add silane coupling agent, photoinitiator, substrate wetting agent, leveling agent and photoaging agent and stir at medium speed for 20 to 30 minutes;

[0054] Stir the phenolic amine curing agent and butyl acetate at low speed for 20 to 30 minutes.

[0055] In some specific embodiments, in step S1, a mixed solvent is added to adjust the viscosity to 30-40S.

[0056] A third technical solution of the present invention is to provide an application of a transparent primer as described in one of the above technical solutions, wherein the transparent primer is used to be coated on a carbon fiber substrate to form a coating.

[0057] In the present invention, the selected epoxy resin and silane coupling agent can provide good adhesion to the carbon fiber substrate, the UV resin improves the drying property and hardness, and the transparent filler improves the filling property and polishing property. The dual curing combination scheme of epoxy and UV resin is adopted, so that the transparent primer has the advantages of fast drying, good filling, high strength, etc.

[0058] Compared with the prior art, the present invention has the following beneficial effects:

[0059] (1) The epoxy resin selected in the present invention has a similar structure to the matrix material of the carbon fiber material. According to the principle of like dissolves like, the epoxy resin is tightly bonded to the carbon fiber substrate and has good adhesion. The curing of the selected UV resin is achieved by irradiating the initiator in the primer with ultraviolet light. The initiator absorbs ultraviolet light to generate free radicals, which further induce polymerization of monomers and oligomers to form a polymer compound and achieve curing. Since the polymerization reaction is fast and is completed in a few seconds, it can be seen that the curing speed of the UV resin is also very fast. The combination of epoxy and UV dual curing makes the transparent primer have the advantages of fast drying, good filling, and high strength.

[0060] (2) The present invention introduces transparent fillers to reduce the shrinkage of the paint film volume when the primer is cured and cross-linked, which can effectively fill the pores and pits on the surface, thereby solving the problem that the surface of the carbon fiber substrate is porous, rough, and has a woven texture, which is difficult to fill and fill with ordinary transparent primers.

[0061] (3) The preparation process of the transparent primer of the present invention is simple, the raw materials are common and easy to purchase, and the preparation process only requires stirring and other steps to complete. The prepared primer can be quickly cured by baking at 70℃*30min+UV lamp irradiation, with high efficiency and good performance. It is mainly used for surface coating of carbon fiber substrates, can clearly highlight the woven texture of carbon fiber, has superior performance, can be used for coating carbon fiber parts of high-end automobiles, and can also be used for spraying other high-end parts made of carbon fiber materials, and has broad application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0062] Figure 1 This is the appearance of the transparent primer of the present invention coated on a carbon fiber substrate.

[0063] Figure 2 It is the appearance of a clear primer applied on a carbon fiber substrate. DETAILED DESCRIPTION

[0064] The present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments. This embodiment is implemented based on the technical solution of the present invention, and provides a detailed implementation method and specific operation process, but the protection scope of the present invention is not limited to the following embodiments.

[0065] In the following examples, the sources of the raw materials are as follows:

[0066] (1) UV resin: ETERCURE 6185 and ETERCURE 6349 from Changxing Materials Industry Co., Ltd.; CF-3100A from Yueyang Kelifu Synthetic Materials Co., Ltd.;

[0067] (2) Epoxy resin: YPE-128 and YPE-011X75 from Shanghai Yuanbang Chemical Manufacturing Co., Ltd.; E-1011 from Dow Chemical;

[0068] (3) Transparent filler: nano-agglomerates T303 and 6000 mesh T312 produced by Anmi Micro-Nano New Materials (Guangzhou) Co., Ltd.

[0069] (4) Silane coupling agent: silane coupling agent KH-540 and KH560 from Nanjing Shuguang Chemical Group;

[0070] (5) Photoinitiator: BASF's 184-D, 1173; DoubleCure 1256 from Double Bond Chemical;

[0071] (6) Substrate wetting agent: TEGO245 from Digo Company;

[0072] (7) Leveling agent: BYK310, BYK333 from BYK Chemical;

[0073] (8) Photoaging agents: TINUVIN 400 from BASF, TIANSORB 5200 from Tiansheng Chemical;

[0074] (9) Phenolic amine curing agent: CARDOLITE NX-2016 from Cardolite.

[0075] The rest of the raw materials or processing techniques, unless otherwise specified, are conventional commercially available raw materials or conventional processing techniques in the art.

[0076] The proportions of the transparent primer in Examples 1 to 5 are shown in Table 1:

[0077] Table 1

[0078]

[0079]

[0080] The preparation method of the transparent primer of Examples 1 to 5 comprises the following steps:

[0081] ① Add UV resin and epoxy resin into the tank in order, and stir at low speed (about 400rpm) for about 12 minutes;

[0082] ② Add the transparent filler under low-speed stirring, stir at high speed (about 1200rpm) for about 40 minutes after adding, and check that the fineness is less than 5 microns;

[0083] ③ Reduce the speed to about 400 rpm, add silane coupling agent, photoinitiator, substrate wetting agent, leveling agent and light aging agent in sequence, and stir at medium speed (about 700 rpm) for about 25 minutes after adding;

[0084] ④Finally, add the mixed solvent to adjust the viscosity to 35S to obtain component A.

[0085] The above operations ① to ④ need to be performed away from sunlight.

[0086] ⑤ Dissolve the phenolic amine curing agent in the solvent and stir at a low speed (about 400 rpm) for about 25 minutes to obtain component B.

[0087] ⑥ Evenly mix component A and component B in a weight ratio of 100:10 to prepare a transparent primer.

[0088] The transparent primer composition prepared in Examples 1-5, together with conventional UV primer and epoxy primer on the market, were sprayed on a carbon fiber substrate at the same time, and the paint appearance and dry film coating were tested for hardness, adhesion, water resistance, moisture resistance, polishing and weather resistance. The test results are shown in Table 2.

[0089] Figure 1 The appearance of the transparent primer of the present invention applied on the carbon fiber substrate, Figure 2 This is the appearance of Nippon paint's universal transparent primer coated on a carbon fiber substrate. It can be seen that the transparent primer of the present invention can effectively fill the pores and pits on the surface of the carbon fiber substrate and has a woven texture, which is difficult to fill and level with other transparent primers on the market.

[0090] The test standards or methods in Table 2 are carried out according to the methods described in the following standards.

[0091] Color: Tested in accordance with GB / T1722-92.

[0092] Appearance: Visually judge the color of the liquid.

[0093] Drying time: Tested in accordance with GB1728-1979.

[0094] Hardness: Tested in accordance with GB / T 6739 standard, load 750g.

[0095] Adhesion: GB9286-1998 standard test.

[0096] Water resistance: Tested according to ASTM D870 standard.

[0097] Moisture resistance: Tested according to the moisture and heat aging resistance method F3 in Q / JLY J7110192.

[0098] Sandability: Sand with 800 grit sandpaper to see if it is sandpaper.

[0099] Weather resistance: Test according to the test method specified in Q / JLY J7110279.

[0100] Table 2

[0101]

[0102]

[0103] According to the above comparative test results, it can be seen that the transparent primer prepared by the present invention can be used as a transparent primer applied to carbon fiber substrates, and its appearance, adhesion, hardness, moisture resistance, water resistance and weather resistance, and overall performance are significantly better than UV and epoxy.

[0104] The above description of the embodiments is to facilitate the understanding and use of the invention by those skilled in the art. It is obvious that those skilled in the art can easily make various modifications to these embodiments and apply the general principles described herein to other embodiments without creative work. Therefore, the present invention is not limited to the above embodiments, and improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the present invention should be within the scope of protection of the present invention.

Claims

1. A transparent primer, characterized in that: The composition is composed of component A and component B in a weight ratio of 100:(10-20), wherein component A is composed of the following components and raw materials in parts by weight: Component B is composed of the following components and raw materials in parts by weight: 70-90 parts of phenalkamine curing agent; 10-30 parts of butyl acetate; Wherein, the mixed solvent is any one of butyl acetate, propylene glycol methyl ether acetate, 100# solvent oil, and cyclohexanone, or a mixed solvent composed of several of them.

2. The transparent primer according to claim 1, characterized in that Component A is composed of the following components and raw materials in parts by weight: 20-30 parts of UV resin, 10-15 parts of epoxy resin, 20-30 parts of transparent filler, 1-2 parts of silane coupling agent, 0.5-2 parts of photoinitiator, 0.5-1 parts of substrate wetting agent, 0.2-0.8 parts of leveling agent, 0.6-1.5 parts of light aging aid, 20-30 parts of mixed solvent; Component B is composed of the following components and raw materials in parts by weight: Phenolic amine curing agent 75-90 parts, solvent 20-30 parts.

3. The transparent primer according to claim 1, characterized in that In component A, the UV resin is a low-functionality oligomer UV resin; The epoxy resin is a low molecular weight epoxy resin; The transparent filler is a transparent inorganic non-metallic functional powder; The silane coupling agent is a methoxy-containing silane coupling agent.

4. The transparent primer according to claim 3, characterized in that: The UV resin is selected from any one of ETERCURE 6185UV resin, ETERCURE 6349UV resin, and CF-3100A UV resin; The epoxy resin is selected from any one of YPE-128 epoxy resin, YPE-011X75 epoxy resin, and E-1011 epoxy resin; The transparent filler is selected from T303 filler or T312 filler; The silane coupling agent is selected from KH-540 coupling agent or KH560 coupling agent.

5. The transparent primer according to claim 1, characterized in that: In component A, the photoinitiator is selected from any one of 184-D photoinitiator, 1173 photoinitiator, and DoubleCure 1256 photoinitiator; The substrate wetting agent is TEGO245 substrate wetting agent; The leveling agent is selected from BYK310 leveling agent or BYK333 leveling agent; The photoaging aid is selected from TINUVIN 400 photoaging aid or TIANSORB 5200 photoaging aid; In component B, the phenalkamine curing agent is CARDOLITE NX-2016 phenalkamine curing agent.

6. A method for preparing a transparent primer as claimed in any one of claims 1 to 5, characterized in that: The steps include: S1. In a dark environment, add UV resin and epoxy resin to a cylinder in order, and stir at a low speed first; then add transparent filler under low-speed stirring, stir at a high speed after adding, and check that the fineness is less than 5 microns; then reduce the speed to a low speed, add silane coupling agent, photoinitiator, substrate wetting agent, leveling agent and light aging aid in sequence, and stir at a medium speed after adding; finally, add a mixed solvent to adjust the viscosity to obtain component A; S2, dissolving the phenalkamine curing agent in butyl acetate, and stirring at a low speed to obtain component B; S3, evenly mix component A and component B to obtain a transparent primer.

7. The preparation method according to claim 6, characterized in that: In step S1 and step S2, the low speed is 300-500 rpm, the medium speed is 600-800 rpm, and the high speed is 1000-1500 rpm.

8. The preparation method according to claim 6, characterized in that: In step S1 and step S2, the UV resin and the epoxy resin are stirred at a low speed for 10 to 15 minutes; Add transparent filler and stir at high speed for 30 to 45 minutes; Add silane coupling agent, photoinitiator, substrate wetting agent, leveling agent and photoaging agent and stir at medium speed for 20 to 30 minutes; Stir the phenolic amine curing agent and butyl acetate at low speed for 20 to 30 minutes.

9. The preparation method according to claim 6, characterized in that: In step S1, a mixed solvent is added to adjust the viscosity to 30-40S.

10. A use of the transparent primer as claimed in any one of claims 1 to 5, characterized in that: The transparent primer is used for coating on a carbon fiber substrate to form a coating.

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