A low-shrinkage vinyl ester glass flake paint and its preparation method

Abstract

This invention discloses a low-shrinkage vinyl ester glass flake paint and its preparation method; specifically, it includes the following steps: 1) pre-dispersing vinyl ester resin, double-terminated vinyl silicone oil, and styrene, maintaining a constant temperature, and dispersing evenly within a specified time; 2) continuing to add thixotropic agents, dispersants, defoamers, polymer fillers, glass flakes, etc., and dispersing evenly within a specified time to obtain a uniform viscous coating; 3) curing the obtained coating with an accelerator, curing agent, and free radical inhibitor in a certain proportion, with different amounts of curing agent used at different temperature gradients. This invention has the following advantages: the product has low shrinkage, resulting in a paint film that is resistant to peeling and flaking; the paint film also possesses excellent water resistance, solvent resistance, and acid resistance; and it is convenient to apply, avoiding the traditional "resin pre-coating" and two-step method.

Description

Technical Field

[0001] This invention belongs to the field of vinyl ester modification and application technology, specifically relating to a low-shrinkage vinyl ester glass flake paint and its preparation method. Background Technology

[0002] Common problems encountered during the application of vinyl ester glass flake coatings include cracking, peeling, and flaking of the coating. The main reasons are the high curing shrinkage rate (7%-10%) and high thermal shrinkage rate of the resin itself. Currently, the conventional solution is to pre-coat a protective resin layer on the metal, cement, or other substrate before applying the coating to increase the adhesion between the substrate and the glass flake coating, preventing cracking and peeling. However, this method increases the coating application process and time, and negatively impacts the coating's corrosion resistance. Therefore, finding ways to reduce the curing shrinkage and thermal shrinkage of the resin itself becomes crucial.

[0003] As a type of unsaturated resin, vinyl ester undergoes macroscopic volume changes during curing or heating, and many factors affect the volume shrinkage rate: (1) the type and molecular structure of vinyl ester, molecular weight, double bond content, etc.; (2) the type and amount of curing agent; (3) the amount of crosslinking agent represented by styrene; (4) the molding temperature and construction process; (5) the pigment volume ratio in the coating formulation. These factors take into account the key points in the coating formulation, but ignore the internal stress and microscopic changes in the structure of vinyl ester during the curing process. The "free volume" of polymers can increase the fluidity of polymers and chain segments, and play a role in eliminating internal stress. How to increase the "free volume" of vinyl esters during the curing process has become a key factor in preventing resin shrinkage. Double-terminated vinyl silicone oil has the general properties of silicone oil, contains a large number of silicon-oxygen bonds, and theoretically can play a plasticizing effect in the cured substrate. In addition, it also has the following properties: (1) the vinyl groups at both ends have strong reactivity with vinyl esters; (2) compared with branched vinyl silicone oils, the molecules have no dangling chain segments; (3) it has better compatibility with organic materials than silicone oils and is easy to formulate with vinyl ester resins. Furthermore, conventional silicone modification is not commonly found in vinyl ester resin modification research. Summary of the Invention

[0004] The purpose of this invention is to address the shrinkage problem of vinyl esters during curing or heating by providing a silicon-modified polymer copolymerization modification method. This invention, through formulation design, provides a silicon-modified low-shrinkage vinyl ester glass flake paint and its preparation method. Unlike conventional methods that control resin dosage, crosslinking agent addition, and molding process, this invention employs the "free volume theory" to increase the degree of freedom of the vinyl ester molecular chains, eliminating internal stress generated during resin curing or heating, thus achieving an anti-shrinkage effect. Finally, through formulation design, it avoids the traditional "two-step" construction method, reducing the workload of large-area construction, reducing the volatilization of styrene and other substances, and making it safer and more environmentally friendly.

[0005] To achieve the above objectives, the present invention provides the following technical solution: This invention provides a method for preparing a low-shrinkage vinyl ester glass flake paint, the method comprising the following steps: S1. Pre-disperse the vinyl ester resin, double-terminated vinyl silicone oil, and styrene (into a disperser), keeping the temperature constant, and disperse them evenly within a specified time. S2. Continue to add thixotropic agent, dispersant, defoamer, polymer filler, and glass flakes, and disperse them evenly within the specified time to obtain a viscous coating; S3. The viscous coating is cured using an accelerator and a curing agent.

[0006] As one aspect of the present invention, the vinyl resin is selected from any one or more of bisphenol A type epoxy vinyl ester resin, phenolic epoxy vinyl ester resin, and bromine-containing epoxy vinyl ester resin.

[0007] As one aspect of the present invention, the raw materials contain, by weight, 25-35 parts of vinyl ester resin, 1-10 parts of double-terminated vinyl silicone oil, and 20-30 parts of styrene.

[0008] As one aspect of the present invention, the polymer filler includes at least one of polystyrene microspheres, polypropylene ultrafine powder, ABS ultrafine powder, PVDF ultrafine powder, and PTFE ultrafine powder.

[0009] As one aspect of the present invention, other raw materials also include, by weight, 1-4 parts of thixotropic agent, 0.2-2 parts of dispersant, 0.1-1 parts of defoamer, 2-10 parts of polymer filler, and 25-35 parts of glass flakes.

[0010] As one aspect of the present invention, the dispersion temperature is 15-30℃ and the dispersion time is 30-90 minutes.

[0011] As one aspect of the present invention, the curing temperature is 5-40°C. In some embodiments, room temperature curing is preferred.

[0012] As one aspect of the present invention, in step S1, the temperature is 15-30 ℃; the specified time is within 90 minutes; such as 30-90 minutes.

[0013] As one aspect of the present invention, in step S2, the specified time is within 90 minutes; for example, 30-90 minutes.

[0014] In one embodiment of the present invention, the thixotropic agent is liquid paraffin. The dispersant is silicone oil. The defoamer is a silicone-containing defoamer. The accelerator is cobalt isooctanoate. The curing agent is cumene peroxide.

[0015] As one aspect of the present invention, the weight ratio of the vinyl ester resin, accelerator, and curing agent is 30:1.5-1.8:0.1-0.7.

[0016] The present invention also provides the use of the low-shrinkage vinyl ester glass flake paint prepared by the above method. This low-shrinkage vinyl ester glass flake paint is used to prepare anti-corrosion coatings. The curing shrinkage and heat shrinkage problems of the resulting paint film are significantly improved.

[0017] The principle of this invention lies in increasing the degree of freedom of the vinyl ester molecular chain using the "free volume theory," thereby eliminating internal stress generated during resin curing or heating and achieving an anti-shrinkage effect. Through formula design, the traditional "two-step" construction method is avoided, reducing the workload of large-area construction and making it safer and more environmentally friendly.

[0018] Compared with the prior art, the present invention has the following beneficial effects: 1) The product has low shrinkage, which corresponds to the paint film being resistant to peeling and flaking.

[0019] 2) The corresponding paint film has excellent water resistance, solvent resistance and acid resistance.

[0020] 3) Convenient construction, avoiding the traditional construction methods of "resin pre-coating" and two-step process. Attached Figure Description

[0021] The following will further explain the concept, specific structure, and technical effects of the present invention with reference to the accompanying drawings, so as to fully understand the purpose, features, and effects of the present invention: Figure 1 The figures are the paint films after the sample paint in Example 1 has been cured for 7 days; Figure (a) shows the paint film without double-ended vinyl silicone, and Figure (b) shows the paint film with double-ended vinyl silicone.

[0022] Figure 2 The paint film is the paint film of the sample paint in Example 1 after being placed in the oven for 4 hours; wherein, Figure (a) is the paint film without double-ended vinyl silicone and Figure (b) is the paint film with double-ended vinyl silicone.

[0023] Figure 3 The image shows the paint film from Example 1 after it has been immersed in distilled water at 90°C for 30 days.

[0024] Figure 4 This is the state of the paint film sample from Example 1 after being immersed in xylene at 49°C for 30 days.

[0025] Figure 5 The paint film samples from Example 1 are shown in their state after being immersed in acid solutions at different temperatures for 30 days. From left to right, they are 80% concentrated sulfuric acid (room temperature), 75% sulfuric acid (38°C), 50% sulfuric acid (90°C), and 25% sulfuric acid (90°C). Detailed Implementation

[0026] The present invention will be described in detail below with reference to embodiments. These embodiments will help those skilled in the art to further understand the present invention, but do not limit the invention in any way. It should be noted that those skilled in the art can make several adjustments and improvements without departing from the concept of the present invention. These all fall within the protection scope of the present invention.

[0027] Example 1 S1) Place 30 g of bisphenol A type vinyl ester resin, 2 g of double-terminated vinyl silicone oil, and 25 g of styrene into a disperser for pre-dispersion, keeping the temperature constant at 25°C, and disperse evenly within 60 min.

[0028] S2) Continue to add 1 g of liquid paraffin, 2 g of silicone oil, 1 g of silicone defoamer, 5 g of polystyrene filler (particle size 100 micrometers), 25 g of glass flakes, etc., and disperse them evenly within 25℃ and 60 min to obtain a uniform and viscous coating.

[0029] S3) The resulting coating was cured with 1.5 g cobalt isooctanoate and 0.7 g cumene peroxide at a curing temperature of 25°C.

[0030] At 25℃, the prepared coating was applied to the substrate surface in a single application, with a thickness controlled at approximately 1 mm, without any sagging. The prepared coating film and a coating film prepared without dual-terminated vinyl silicone oil were cured for 7 days, and the shrinkage of the coating film was observed. Figure 1 The results showed that the paint film without dual-terminated vinyl silicone experienced severe shrinkage, while the paint film with dual-terminated vinyl silicone showed almost no shrinkage, indicating that the curing shrinkage problem was improved after modification. Figure 2Both the prepared paint film and the paint film without dual-terminated vinyl silicone were placed in an oven at 175℃ for 4 hours, and the shrinkage rate of the samples was tested. The results showed that the shrinkage rate of the paint film without dual-terminated vinyl silicone was 9.1%, while the shrinkage rate of the paint film with dual-terminated vinyl silicone was 1.8%, indicating that the product obtained by this technique exhibits low shrinkage. Furthermore, the prepared paint film also possesses excellent water resistance (…). Figure 3 Solvent resistance Figure 4 ) and acid resistance ( Figure 5 ).

[0031] Example 2 S1) Place 30 g of bisphenol A type vinyl ester resin, 4 g of double-terminated vinyl silicone oil, and 25 g of styrene into a disperser for pre-dispersion, keep the temperature at 30°C, and disperse evenly within 30 min.

[0032] S2) Continue to add 1 g of liquid paraffin, 2 g of silicone oil, 1 g of silicone defoamer, 5 g of polystyrene filler (particle size 100 micrometers), 25 g of glass flakes, etc., and disperse them evenly within 30℃ and 30 min to obtain a uniform and viscous coating.

[0033] S3) The resulting coating was cured with 1.5 g cobalt isooctanoate and 0.7 g cumene peroxide at a curing temperature of 25°C.

[0034] At 25℃, the prepared coating was applied to the substrate surface in a single application, with a thickness controlled at approximately 1 mm, without any sagging. The prepared coating film and the coating film without dual-terminated vinyl silicone oil were cured for 7 days, and the shrinkage was observed. The results showed that the coating film without dual-terminated vinyl silicone oil shrank significantly, while the coating film with dual-terminated vinyl silicone oil showed almost no shrinkage, indicating that the curing shrinkage problem was improved after modification. Both the prepared coating film and the coating film without dual-terminated vinyl silicone oil were placed in a 175℃ oven for 4 hours, and the shrinkage rate of the samples was tested. The results showed that the shrinkage rate of the sample without dual-terminated vinyl silicone oil was 9.1%, while the shrinkage rate of the sample with dual-terminated vinyl silicone oil was 1.5%, indicating that the product obtained by this technique exhibited low sample shrinkage.

[0035] Example 3 S1) Place 30 g of bisphenol A type vinyl ester resin, 6 g of double-terminated vinyl silicone oil, and 25 g of styrene into a disperser for pre-dispersion, keep the temperature constant at 15°C, and disperse evenly within 90 min.

[0036] S2) Continue to add 1 g of liquid paraffin, 2 g of silicone oil, 1 g of silicone defoamer, 5 g of polystyrene filler (particle size 100 micrometers), 25 g of glass flakes, etc., and disperse them evenly within 15℃ and 90 min to obtain a uniform and viscous coating.

[0037] S3) The resulting coating was cured with 1.5 g cobalt isooctanoate and 0.7 g cumene peroxide at a curing temperature of 25°C.

[0038] At 25℃, the prepared coating was applied to the substrate surface in a single application, with a thickness controlled at approximately 1 mm, without any sagging. The prepared coating film and the coating film without dual-terminated vinyl silicone oil were cured for 7 days, and the shrinkage was observed. The results showed that the coating film without dual-terminated vinyl silicone oil shrank significantly, while the coating film with dual-terminated vinyl silicone oil showed almost no shrinkage, indicating that the curing shrinkage problem was improved after modification. Both the prepared coating film and the coating film without dual-terminated vinyl silicone oil were placed in a 175℃ oven for 4 hours, and the shrinkage rate of the samples was tested. The results showed that the shrinkage rate of the sample without dual-terminated vinyl silicone oil was 9.1%, while the shrinkage rate of the sample with dual-terminated vinyl silicone oil was 1.4%, indicating that the product obtained by this technique exhibited low sample shrinkage.

[0039] Example 4 S1) Place 30 g of bisphenol A type vinyl ester resin, 8 g of double-terminated vinyl silicone oil, and 25 g of styrene into a disperser for pre-dispersion, keeping the temperature constant at 25°C, and disperse evenly within 60 min.

[0040] S2) Continue to add 1 g of liquid paraffin, 2 g of silicone oil, 1 g of silicone defoamer, 5 g of polystyrene filler, 25 g of glass flakes, etc., and disperse them evenly within 25℃ and 60 min to obtain a uniform and viscous coating.

[0041] S3) The resulting coating was cured with 1.5 g cobalt isooctanoate and 0.7 g cumene peroxide at a curing temperature of 25°C.

[0042] At 25℃, the prepared coating was applied to the substrate surface in a single application, with a thickness controlled at approximately 1 mm, without any sagging. The prepared coating film and the coating film without dual-terminated vinyl silicone oil were cured for 7 days, and the shrinkage was observed. The results showed that the coating film without dual-terminated vinyl silicone oil shrank significantly, while the coating film with dual-terminated vinyl silicone oil showed almost no shrinkage, indicating that the curing shrinkage problem was improved after modification. Both the prepared coating film and the coating film without dual-terminated vinyl silicone oil were placed in a 175℃ oven for 4 hours, and the shrinkage rate of the samples was tested. The results showed that the shrinkage rate of the sample without dual-terminated vinyl silicone oil was 9.1%, while the shrinkage rate of the sample with dual-terminated vinyl silicone oil was 1.6%, indicating that the product obtained by this technique exhibited low sample shrinkage.

[0043] Comparative Example 1 S1) Place 30 g of bisphenol A type vinyl ester resin, 2 g of dibutyl phthalate (plasticizer), and 25 g of styrene into a disperser for pre-dispersion, keep the temperature at 25°C, and disperse evenly within 60 min.

[0044] S2) Continue to add 1 g of liquid paraffin, 2 g of silicone oil, 1 g of silicone defoamer, 5 g of polystyrene filler (particle size 100 micrometers), 25 g of glass flakes, etc., and disperse them evenly within 25℃ and 60 min to obtain a uniform and viscous coating.

[0045] S3) The resulting coating was cured with 1.5 g cobalt isooctanoate and 0.7 g cumene peroxide at a curing temperature of 25°C.

[0046] At 25℃, the prepared coating was applied to the substrate surface in a single application, with a thickness controlled at approximately 1 mm, without any sagging. The prepared coating film and the coating film without dibutyl phthalate were cured for 7 days, and the shrinkage was observed. The results showed that the shrinkage of the coating film containing dibutyl phthalate was comparable to that without the plasticizer, indicating that the addition of dibutyl phthalate did not improve the curing shrinkage problem. Both the prepared coating film and the coating film without dibutyl phthalate were placed in a 175℃ oven for 4 hours, and the shrinkage rate of the samples was tested. The results showed that the shrinkage rate of the coating film without dibutyl phthalate was 9.1%, while the shrinkage rate of the coating film containing dibutyl phthalate was 9.0%, indicating that the product obtained by adding dibutyl phthalate did not improve the shrinkage of the samples. This is because the dibutyl phthalate molecule does not contain double bonds and cannot crosslink with vinyl resins.

[0047] The specific embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the specific embodiments described above, and those skilled in the art can make various modifications or variations within the scope of the claims, which do not affect the essence of the present invention.

Claims

1. A method for preparing a low-shrinkage vinyl ester glass flake paint, characterized in that, The method includes the following steps: S1. Pre-disperse vinyl ester resin, double-terminated vinyl silicone oil, and styrene, keeping the temperature constant, and disperse them evenly within a specified time. S2. Continue to add thixotropic agent, dispersant, defoamer, polymer filler, and glass flakes, and disperse them evenly within the specified time to obtain a viscous coating; S3. The viscous coating is cured using an accelerator and a curing agent.

2. The method for preparing the low-shrinkage vinyl ester glass flake paint as described in claim 1, characterized in that, The vinyl resin is selected from any one or more of bisphenol A type epoxy vinyl ester resin, phenolic epoxy vinyl ester resin, and bromine-containing epoxy vinyl ester resin.

3. The method for preparing the low-shrinkage vinyl ester glass flake paint as described in claim 1, characterized in that, By weight, 25-35 parts vinyl ester resin, 1-10 parts double-ended vinyl silicone oil, and 20-30 parts styrene.

4. The method for preparing the low-shrinkage vinyl ester glass flake paint as described in claim 3, characterized in that, It also contains: 1-4 parts thixotropic agent, 0.2-2 parts dispersant, 0.1-1 parts defoamer, 2-10 parts polymer filler, and 25-35 parts glass flakes.

5. The method for preparing the low-shrinkage vinyl ester glass flake paint as described in claim 1, characterized in that, The polymer filler includes at least one of polystyrene microspheres, polypropylene ultrafine powder, ABS ultrafine powder, PVDF ultrafine powder, and PTFE ultrafine powder.

6. The method for preparing the low-shrinkage vinyl ester glass flake paint as described in claim 1, characterized in that, In steps S1 and S2, the dispersion temperature is 15-30℃ and the dispersion time is 30-90 minutes.

7. The method for preparing the low-shrinkage vinyl ester glass flake paint as described in claim 1, characterized in that, The thixotropic agent is liquid paraffin. And / or, the dispersant is silicone oil, And / or, the defoamer is a silicone-containing defoamer. And / or, the accelerator is cobalt isooctanoate, And / or, the curing agent is cumene peroxide.

8. The method for preparing the low-shrinkage vinyl ester glass flake paint as described in claim 1, characterized in that, The curing temperature is 5-40℃.

9. The method for preparing the low-shrinkage vinyl ester glass flake paint as described in claim 1, characterized in that, The weight ratio of the vinyl ester resin, accelerator, and curing agent is 30:1.5-1.8:0.1-0.

7.

10. Use of a low-shrinkage vinyl ester glass flake paint prepared by any one of claims 1 to 9 in anti-corrosion coatings.

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