Method for testing sagging performance of anti-sagging resin

Abstract

The invention relates to a method for testing the sagging performance of anti-sagging resin (hereinafter referred to as SCA resin), which adopts a rheometer to carry out fixed deformation scanning in an oscillation mode to obtain the storage modulus G'and the loss modulus G '' of a sample to be tested, and the sagging performance of the anti-sagging resin is obtained by analyzing the relationship between the two moduli. The method is rapid and accurate, the sagging performance test can be carried out without preparing the anti-sagging resin into the coating, the test error caused by the difference of the coating formula end is avoided, the method can be applied to the detection of the resin production process, and the detection efficiency of the SCA resin is improved.

Description

Technical Field

[0001] The invention relates to the field of resin rheological property testing, and in particular to a method for testing the sag performance of an anti-sag resin. Background Art

[0002] The degree of sag in a paint depends on the rate and extent of viscosity increase during flash drying after application, in addition to other factors such as coating thickness. For Newtonian paints, the rate of viscosity increase depends solely on solvent evaporation. For thixotropic paints, such as SCA paints, the degree of sag resistance also depends on the thixotropic effect, with a strong thixotropic effect indicating a paint with significantly improved sag resistance compared to a similar paint without the thixotropic effect.

[0003] In the prior art, testing the sag performance of anti-sag resins often requires placing the resin in an actual coating formulation. For example, as described in detail by M. Bosma et al. in Progress in Organic Coatings, 55, 97-104 (2006), the sag degree of thixotropic paint during flash drying and therefore the effect of SCA can be described by measuring the creep compliance J of the paint under conditions equivalent to the actual paint conditions. The specific method includes: at room temperature (23°C) for 300 seconds, with a shear stress equivalent to that of wet paint applied on a vertical plate (about 0.7 Pa for a 70 μm thick wet paint layer). Alternatively, the anti-sag resin can be formulated into a coating and then sprayed on a sag plate with small holes, and the anti-sag effect of the resin can be determined by comparing the sag degree under different film thicknesses. Both of the above methods require the resin to be applied to a specific coating formulation, which takes a long time.

[0004] In view of this, there is an urgent need in the art for a method for testing sag performance without formulating an anti-sag resin into a coating, so as to improve the detection efficiency and solve the problems existing in the prior art. Summary of the invention

[0005] Based on the above facts, the purpose of the present invention is to provide a method for testing the sag performance of an anti-sag resin, which uses a rheometer to perform fixed deformation scanning in an oscillation mode to obtain the storage modulus G' and the loss modulus G'' of the sample to be tested, and analyzes the relationship between the two moduli to obtain the sag performance of the anti-sag resin. This method is fast and accurate, and the sag performance test can be performed without preparing the anti-sag resin into a coating, thereby avoiding the test error caused by the difference in the coating formulation end, and can be applied to the production process detection of the resin to improve the detection efficiency of the SCA resin.

[0006] A first aspect of the present invention provides a method for testing the sag performance of an anti-sag resin, comprising the following steps:

[0007] S1: Select a suitable cone plate, load the SCA resin, and set the strain amplitude (%), frequency (rad / s), and the number of repeated points for each amplitude in the rheometer;

[0008] S2: Start the rheometer to test, obtain the amplitude scanning curve, and obtain the storage modulus G' and loss modulus G" at each strain amplitude;

[0009] S3: According to the amplitude scanning curve obtained in step S2, the yield stress of the SCA resin is obtained by analyzing the convergence points under the two moduli.

[0010] In some embodiments of the present invention, the method for testing the sag performance of the anti-sag resin is carried out in the following environment: temperature of 10-40° C., humidity of 20-70%, and compressed air pressure of 0.1-0.9 MPa.

[0011] In some preferred embodiments of the present invention, the cone plate is selected from a 50 mm cone plate or a 60 mm cone plate; more preferably, the cone plate is a 60 mm cone plate.

[0012] In some preferred embodiments of the present invention, the strain amplitude range is 0.01%-100%; more preferably, the strain amplitude range is 0.1%-80%; further preferably, the strain amplitude range is 0.1%-55%. The strain amplitude increases logarithmically during the test.

[0013] In some preferred embodiments of the present invention, the frequency is 5-50 rad / s; more preferably, the frequency is 10-30 rad / s; even more preferably, the frequency is 15-25 rad / s.

[0014] In some preferred embodiments of the present invention, the number of repeated point taking for each amplitude is 5-15 times; more preferably, the number of repeated point taking for each amplitude is 10 times.

[0015] Beneficial effects of the present invention

[0016] The present invention provides a method for testing the sag performance of an anti-sag resin. The method uses a rheometer to perform fixed deformation scanning in an oscillation mode to obtain the storage modulus G' and the loss modulus G'' of a sample to be tested, and the sag performance of the anti-sag resin is obtained by analyzing the relationship between the two moduli. The method is fast and accurate, and the sag performance test can be performed without preparing the anti-sag resin into a coating, thereby avoiding the test error caused by the difference in the coating formulation end. The method can be applied to the production process detection of the resin to improve the detection efficiency of the SCA resin. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1The amplitude scan diagram and yield stress fitting diagram of Setal 91715SS-55 resin in Example 1 are shown.

[0018] Figure 2 The amplitude scanning diagram and yield stress fitting diagram of SCA 01 resin in Example 1.

[0019] Figure 3 The amplitude scanning diagram and yield stress fitting diagram of Setalux 91796 resin in Example 2 are shown.

[0020] Figure 4 The amplitude scanning diagram and yield stress fitting diagram of SCA 02 resin in Example 2. DETAILED DESCRIPTION

[0021] In order to more clearly illustrate the present invention, the present invention is further described below in conjunction with preferred embodiments and accompanying drawings. It should be understood by those skilled in the art that the content described below is illustrative rather than restrictive, and should not be used to limit the scope of protection of the present invention. The experimental methods used in the embodiments are conventional methods unless otherwise specified; the materials, reagents, etc. used, unless otherwise specified, can be obtained from commercial channels.

[0022] Example 1: Testing the sag performance of Allnex commercial product Setal 91715SS-55 and homemade resin SCA 01

[0023] The sag performance of Allnex's commercial product Setal 91715SS-55 and the homemade resin SCA 01 was tested, including the following steps:

[0024] S1: Select a 60 mm cone plate, load Setal 91715SS-55 and SCA 01 resins respectively, set the amplitude scanning parameters in the rheometer: the strain amplitude range is set to 0.1%-80%, increasing in a logarithmic manner, the frequency is set to 7 rad / s, and each amplitude is repeated 10 times;

[0025] S2: Start the rheometer to test and get the amplitude scanning curve. The amplitude scanning graph and yield stress fitting graph of Setal 91715SS-55 are shown in the figure below: Figure 1 As shown in the figure, the amplitude scanning diagram and yield stress fitting diagram of the homemade SCA 01 resin are shown in Figure 2 As shown, the storage modulus G' and loss modulus G" of the two resins at each strain amplitude are obtained respectively;

[0026] S3: According to Figure 1 , Figure 2 The amplitude sweep curve shown is used to obtain the yield stress of the two resins by analyzing the convergence points under the two moduli.

[0027] Comparative Example 1: Allnex commercial product Setal 91715SS-55 and homemade resin SCA 01 were mixed into a coating for sag performance test

[0028] Allnex commercial product Setal 91715SS-55 and homemade resin SCA 01 were formulated into varnish, and spraying tests were carried out. The actual anti-sagging effect of Allnex commercial product Setal 91715SS-55 and SCA 01 resin was obtained by testing the sagging limit, which was expressed as the varnish sagging limit (mm). The varnish formula used is shown in Table 1.

[0029] Table 1 Varnish formula

[0030]

[0031]

[0032] The test results are shown in Table 2.

[0033] Table 2 Comparison of yield stress and sag limit

[0034] sample Varnish sagging limit / mm Yield stress / Pa Setal 91715SS-55 46 8.346 SCA 01 50 11.732

[0035] It can be seen from Table 2 that the yield stress of the anti-sagging resin has a good corresponding relationship with the sag limit of the varnish. The higher the yield stress and the larger the sag limit, the better the anti-sagging effect of the anti-sagging resin.

[0036] Example 2: Testing the sag performance of Allnex commercial product Setalux 91796 and homemade resin SCA 02

[0037] The sag performance of Allnex's commercial product Setalux 91796 and the homemade resin SCA 02 were tested in the same manner as in Example 1. The amplitude scanning diagram and yield stress fitting diagram of Setalux 91796 are shown in FIG. Figure 3 As shown in the figure, the amplitude scanning diagram and yield stress fitting diagram of the homemade SCA 02 resin are shown in Figure 4 shown.

[0038] Comparative Example 2: Allnex commercial product Setalux 91796 and homemade resin SCA02 were mixed into a coating for sag performance test

[0039] Allnex commercial product Setalux 91796 and homemade resin SCA 02 were mixed into varnish, and sprayed for application test. The actual anti-sagging effect of Allnex commercial product Setalux 91796 and homemade resin SCA02 was obtained by testing the sagging limit, which was expressed as varnish sagging limit (mm). The varnish formula used is shown in Table 3.

[0040] Table 3 Varnish formula

[0041]

[0042]

[0043] The test results are shown in Table 4.

[0044] Table 4 Comparison of yield stress and sag limit

[0045] sample Varnish sagging limit / mm Yield stress / Pa Setalux 91796 40 3.263 SCA02 45 7.916

[0046] It can also be seen from Table 4 that the yield stress of the anti-sagging resin has a good corresponding relationship with the sag limit of the varnish. The higher the yield stress and the larger the sag limit, the better the anti-sagging effect of the anti-sagging resin.

[0047] In summary, the method of the present invention is fast and accurate, and the sag performance test can be performed without formulating the anti-sag resin into a coating, thereby avoiding the test error caused by the difference in the coating formulation. At the same time, the test method of the present invention only requires 7 minutes of rheological test time to obtain the corresponding yield stress value, which is greatly shortened compared to the application spraying time (about 1-2 hours). Therefore, it can be used for quality control in the SCA production process to improve the detection efficiency of SCA resin.

[0048] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not limitations on the implementation methods of the present invention. For ordinary technicians in the relevant field, other different forms of changes or modifications can be made based on the above description. It is impossible to list all the implementation methods here. All obvious changes or modifications derived from the technical solution of the present invention are still within the protection scope of the present invention.

Claims

1. A method for testing the sagging performance of an anti-sagging resin, characterized in that: The following steps are involved: S1: Select a suitable cone plate, load the SCA resin, and set the strain amplitude (%), frequency (rad / s), and the number of repeated points for each amplitude in the rheometer; S2: Start the rheometer to test, obtain the amplitude scanning curve, and obtain the storage modulus G' and loss modulus G" at each strain amplitude; S3: According to the amplitude scanning curve obtained in step S2, the yield stress of the SCA resin is obtained by analyzing the convergence points under the two moduli.

2. The method for testing the sag performance of anti-sag resin according to claim 1, characterized in that: The method for testing the sag performance of the anti-sag resin is carried out in the following environment: temperature of 10-40° C., humidity of 20-70%, and compressed air pressure of 0.1-0.9 MPa.

3. The method for testing the sag performance of anti-sag resin according to claim 1, characterized in that: The cone plate is selected from a 50 mm or 60 mm cone plate; preferably, the cone plate is a 60 mm cone plate.

4. The method for testing the sag performance of anti-sag resin according to claim 1, characterized in that: The strain amplitude range is 0.01%-100%; preferably, the strain amplitude range is 0.1%-80%; more preferably, the strain amplitude range is 0.1%-55%.

5. The method for testing the sag performance of anti-sag resin according to claim 1 or 4, characterized in that: The strain amplitude was increased logarithmically during the test.

6. The method for testing the sag performance of anti-sag resin according to claim 1, characterized in that: The frequency is 5-50 rad / s; preferably, the frequency is 10-30 rad / s; more preferably, the frequency is 15-25 rad / s.

7. The method for testing the sag performance of anti-sag resin according to claim 1, characterized in that: The number of points taken for each amplitude is repeated 5-15 times.

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