Multi-scale two-dimensional mica sheet layer modified anti-aging PVC profile and preparation method thereof

Abstract

The invention provides a multi-scale two-dimensional mica sheet layer modified anti-aging PVC (polyvinyl chloride) profile and a preparation method of the multi-scale two-dimensional mica sheet layer modified anti-aging PVC profile. The PVC profile comprises a PVC general profile ingredient, a large-sheet-diameter mica sheet with the transverse size of 20 [mu] m-100 [mu] m and a small-sheet-diameter mica sheet with the transverse size of 1 [mu] m-10 [mu] m, wherein the large-sheet-diameter mica sheet and the small-sheet-diameter mica sheet are compounded in the PVC profile in a sheet form. The multi-scale two-dimensional mica sheet layer modified anti-aging PVC profile obtained by the application has a micro-scale multi-scale structure, wherein the anti-aging profile is endowed with an excellent anti-ultraviolet aging effect through the synergistic effect of the large-sheet-diameter mica sheets and the small-sheet-diameter mica sheets in the whole material system. The method for preparing the anti-aging PVC profile with high added value by using the natural two-dimensional mica sheet layer has the advantages of simple preparation process, short flow, high temperature resistance, good stability, excellent anti-ultraviolet aging effect and the like.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of PVC composite materials, in particular to a multi-scale two-dimensional mica sheet layer modified anti-aging PVC profile and a preparation method thereof. BACKGROUND

[0002] PVC (polyvinyl chloride) resin is one of the most widely used general-purpose plastics in the world, but due to the characteristics of PVC polymer itself, PVC products will undergo degradation of PVC molecular chain, color change of material and powdering phenomenon after long-term irradiation of ultraviolet light. This property of not resisting ultraviolet aging will cause the mechanical properties such as tensile strength and impact strength of PVC products to decrease and the service life to be shortened during use, thereby affecting the economy and environmental protection of outdoor use of the material and greatly limiting the application range.

[0003] Mica is a natural mineral with a layered structure, which presents a hexagonal sheet crystal form, and has a polarizing and interference effect. Natural mica also has many excellent chemical properties, such as chemical stability, high temperature resistance, low cost, ultraviolet shielding property, etc., which makes it have wide application potential and value in many fields. The most commonly used sericite (KAl2(Si, Al)4O 10 (OH, F)2) in industry is widely used in insulation, coating and other industries. In the existing application field of PVC, mica is usually added to PVC as a mechanical reinforcing agent. SUMMARY

[0004] The technical problem solved by the present application is to provide a multi-scale two-dimensional mica sheet layer modified anti-aging PVC profile and a preparation method thereof. The anti-aging PVC profile provided by the present application has high strength, high toughness, high temperature resistance, low cost, simple process, excellent ultraviolet aging resistance and other characteristics and functions.

[0005] To this end, the present application provides the following aspects:

[0006] <1> A PVC profile, comprising a PVC general profile formulation, large flake diameter mica flakes with a transverse size of 20-100 μm, and small flake diameter mica flakes with a transverse size of 1-10 μm, wherein the large flake diameter mica flakes and the small flake diameter mica flakes are compounded in the PVC profile in the form of flakes.

[0007] <2> The PVC profile according to <1>, wherein the mass ratio of the large flake diameter mica flakes to the small flake diameter mica flakes is in the range of 0.5-2.5.

[0008] <3> The PVC profile according to <1>, wherein the PVC general profile formulation comprises the following components:

[0009] PVC 100 parts,

[0010] Environmental stabilizer 3.5-6 parts,

[0011] Titanium white 5-12 parts,

[0012] Impact resistance ACR modifier 4-7 parts,

[0013] Impact resistance CPE modifier 4-8 parts,

[0014] Processing aid 0.5-2 parts,

[0015] Filling agent 5-12 parts,

[0016] Lubricity regulator 0.02-2.0 parts,

[0017] Color modifier 0-0.1 parts.

[0018] <4> The PVC profile according to claim 1, wherein the PVC general profile formulation is a PVC general profile formulation pretreated at 600-800℃.

[0019] <5> The PVC profile according to claim 1, wherein the d50 of the lateral dimension of the large flake mica flakes is in the range of 30-40 μm, and the d50 of the lateral dimension of the small flake mica flakes is in the range of 2-5 μm.

[0020] <6> The PVC profile according to claim 1, wherein the total content of the large flake mica flakes and the small flake mica flakes is less than 15 wt% of the total content of the PVC general profile formulation and the mica flakes.

[0021] <7> The PVC profile according to <1>, wherein the large flake mica flakes and the small flake mica flakes are both obtained by exfoliation of a sericite mineral.

[0022] <8> A method for preparing the PVC profile according to any one of <1>-<7>, the method comprising the following steps:

[0023] a) treating a sericite mineral to obtain large flake mica flakes with a lateral dimension of 20-100 μm and small flake mica flakes with a lateral dimension of 1-10 μm;

[0024] b) mixing the large flake mica flakes and the small flake mica flakes in a formulation amount, and then mixing with a PVC general profile formulation, to obtain an initial mixture, wherein the PVC general profile formulation is dried to 50-70℃ before mixing with the mica;

[0025] c) compression molding the initial mixture to obtain a multi-scale mica flake composite PVC profile.

[0026] <9> The method of <8>, wherein the step a) includes:

[0027] i) pretreating the sericite mineral at 600-800°C and holding at the maximum temperature,

[0028] ii) then mixing the sericite mineral obtained in step i) with deionized water at a mass ratio of 0.01-0.02, and obtaining large-diameter mica sheets after suspension and sedimentation,

[0029] iii) then ball-milling the large-diameter mica sheets obtained to obtain small-diameter mica sheets.

[0030] <10> The method of <8>, wherein the large-diameter mica sheets and the small-diameter mica sheets in step b) are mixed at a mass ratio of 0.5-2.5 before being mixed into a PVC general profile formulation, and after being uniformly dispersed by shaking, the mixture is uniformly mixed with the PVC general profile formulation to obtain a mixed powder.

[0031] <11> The method of <8>, wherein step c) includes: melting the mixed powder obtained in step b) by a mixing mill at 185-205°C, and then pressing and forming into a multi-scale two-dimensional mica sheet layer modified aging-resistant PVC profile at a pressure of 1500-1800 bar on a tablet press and a holding pressure of 800-1000 bar. BRIEF DESCRIPTION OF DRAWINGS

[0032] Figure 1 A micrograph of the large-diameter mica prepared by exfoliation from the mica mineral in Example 1, observed under a field emission scanning electron microscope;

[0033] Figure 2 A particle size distribution of the large-diameter mica in Example 1, tested by a Microtrac S3500 laser particle size instrument, with a transverse size distribution range of 20-100 μm;

[0034] Figure 3 A micrograph of the small-diameter mica prepared by exfoliation from the mica mineral in Example 1, observed under a field emission scanning electron microscope;

[0035] Figure 4 A particle size distribution of the small-diameter mica in Example 1, with a transverse size distribution range of 1-10 μm;

[0036] Figure 5 A micrograph of the multi-scale mica prepared by mixing the large-diameter mica sheets and the small-diameter mica sheets in Example 1 at a formulation amount of 2:1;

[0037] Figure 6 Micrograph of the multi-scale two-dimensional mica flake layer modified weatherable PVC profile prepared for Example 1;

[0038] Figure 7 The multi-scale two-dimensional mica flake layer modified weatherable PVC profile prepared for Example 1 was tested under the UV accelerated weathering chamber for 200 hours, and the color change rate ΔE was 8.83908.

[0039] Figure 8 The multi-scale two-dimensional mica flake layer modified weatherable PVC profile prepared for Example 2 was tested under the UV accelerated weathering chamber for 200 hours, and the color change rate ΔE was 9.70314;

[0040] Figure 9 The multi-scale two-dimensional mica flake layer modified weatherable PVC profile prepared for Example 3 was tested under the UV accelerated weathering chamber for 200 hours, and the color change rate ΔE was 9.64151;

[0041] Figure 10 The PVC profile prepared for Comparative Example 1 was tested under the UV accelerated weathering chamber for 200 hours, and the color change rate ΔE was 9.83628;

[0042] Figure 11 The PVC profile prepared for Comparative Example 2 was tested under the UV accelerated weathering chamber for 200 hours, and the color change rate ΔE was 9.76401. DETAILED DESCRIPTION

[0043] A first aspect of the present application provides a multi-scale two-dimensional mica flake layer modified weatherable PVC profile, comprising a biomimetic fine brick clay structure composed of mica flakes with different flake diameters and a PVC general profile formulation.

[0044] The term “biomimetic fine brick clay structure” refers to an artificial material prepared inspired by the “brick clay” structure of natural nacre having a similar brick clay structure. In the biomimetic fine brick clay structure of the present application, the mica flake layers act as the “brick” structure and the PVC base acts as the “clay” structure.

[0045] The term “multi-scale” refers to the composite of two materials with different flake diameters.

[0046] “Multi-scale two-dimensional mica flake layer” refers to the composite of two-dimensional mica flake layers with different flake diameters in a certain ratio, and examples thereof include a multi-scale two-dimensional mica flake layer composed of large flake diameter mica flakes and small flake diameter mica flakes in a ratio of 2:1, 1:1, or 1:2.

[0047] In the present application, the term "general PVC profile formulation" refers to the conventional meaning in the art. As an example, the present application specifically adopts the general PVC profile formulation of patent application CN104497451A (invention title: A high-gloss environmentally-friendly PVC profile and its preparation method). The corresponding content disclosed in patent application CN104497451A is incorporated by reference herein. Thus, as a preferred example, the general PVC profile formulation includes the following substances in parts by weight: PVC 100 parts, environmentally-friendly stabilizer 3.5-6 parts, titanium white 5-12 parts, impact-resistant ACR modifier 4-7 parts, impact-resistant CPE modifier 4-8 parts, processing aid 0.5-2 parts, filler 5-12 parts, lubrication regulator 0.02-2.0 parts, toning agent 0-0.1 parts. An example of the PVC general profile formulation is the formulation of Haibo PVC profile.

[0048] In the present application, the different sizes of mica flakes are obtained by exfoliation of sericite mineral, and the different sizes of mica flakes have different lateral sizes. The different sizes of mica flakes include: large-size mica flakes (sometimes also referred to as large-scale mica flakes) with lateral sizes of 20-100 μm, and small-size mica flakes (sometimes also referred to as small-scale mica flakes) with lateral sizes of 1-10 μm. The average lateral size d50 of the large-scale mica flakes is 30-40 μm. The average lateral size d50 of the small-scale mica flakes is 2-5 μm.

[0049] In the present application, the ratio of the different sizes of mica flakes is in the range of 0.5-2.5, preferably in the range of 1-2.5, more preferably in the range of 1.9-2.1, and most preferably 2:1.

[0050] In the present application, the content of the different sizes of mica flakes is less than 15 wt% of the total content of the PVC general profile and the mica flakes, preferably less than 12 wt%, and more preferably less than 10 wt%.

[0051] In the present application, the different sizes of mica flakes are pretreated at 600-800 °C before mixing, and the maximum temperature is maintained for about 2-3 hours to ensure uniform heating, so that the layers of the natural mica flakes are expanded and separated, which is beneficial for obtaining the different sizes of mica flakes in the later stage of suspension exfoliation.

[0052] The second aspect of the present application provides a method for preparing the multi-scale two-dimensional mica flake layer modified aging-resistant PVC profile described above, which comprises the following steps:

[0053] A) using the PVC general profile formulation as raw material, and drying the formulation to 50-70 °C before mixing with the mica to obtain a PVC general profile modified formulation;

[0054] B) the mica sheets of different sizes are pre-mixed in a ratio of 0.5-2 times by mass after being pre-treated at 600-800°C before mixing, and are mixed by shaking to obtain mixed mica of different sizes.

[0055] C) the PVC general profile modification ingredients obtained in step A) are mixed with the mixed mica of different sizes obtained in step B) after being mixed by shaking;

[0056] D) the PVC raw material obtained in step C) is high-temperature melted by a mixing machine at 185-205°C, and is pressed on a tablet press at a pressure of 1500-1800 bar and a holding pressure of 800-1000 bar to form a multi-scale two-dimensional mica sheet layer modified aging-resistant PVC profile after cooling;

[0057] In the preparation method described in the application, the pressure on the tablet press in step D) is 1500-1800 bar, and the holding pressure is 800-1000 bar to form a multi-scale two-dimensional mica sheet layer modified aging-resistant PVC profile, so that the sheet layer is uniformly oriented in the PVC profile to obtain a PVC profile with better ultraviolet shielding performance.

[0058] The pre-treatment in step B) includes:

[0059] i) the sericite mineral is pre-treated at 600-800°C and is kept at the highest temperature in the selected temperature range; ii) the obtained mica and deionized water are then mixed in a ratio of 0.01-0.02 by mass by ultrasonic mixing, and large-size mica sheets are obtained after suspension and sedimentation; and iii) the large-size mica sheets are then ball milled to obtain small-size mica sheets.

[0060] The application uses natural mica to modify the aging resistance of PVC materials, and the obtained multi-scale two-dimensional mica sheet layer modified aging-resistant PVC profile has a multi-scale structure of microscale, the large-size mica sheets in the entire material system provide excellent ultraviolet aging resistance, the small-size mica sheets intercalate and fill the pores and defects in the large-size mica system, and the synergistic effect gives the aging-resistant profile excellent ultraviolet aging resistance. In addition, the multi-scale two-dimensional mica sheet layer modified aging-resistant PVC profile has the comprehensive advantages of compression resistance, bending resistance, good hardness, and strong chemical stability due to the addition of natural rock-forming minerals. Moreover, the aging-resistant PVC profile preparation process according to the application is simple, expands the comprehensive utilization of mica, and is easy to operate with a short process, which is suitable for large-scale production and application.

[0061] Example

[0062] In order for those skilled in the art to further understand the present application, and to be able to implement or use the present application, the multi-scale two-dimensional mica sheet layer anti-aging PVC profile provided by the present application is described in more detail below in conjunction with the examples. Therefore, the purpose of these examples is not to limit the protection scope of the present application, and the protection scope of the present application will be defined by the appended claims.

[0063] Large-diameter mica / small-diameter mica is obtained by self-exfoliation in the laboratory, i.e., exfoliated from sericite minerals after mechanical treatment, with a transverse size of several microns to tens of microns. As an example, the exfoliation method is as follows:

[0064] First, the sericite minerals are pretreated at 600-800°C for a certain time, for example, about 2 hours, before mixing, and are kept at the maximum temperature for about 2 hours to ensure uniform heating and facilitate size separation. The mica and deionized water are mixed in a mass ratio of 1:50, and are ultrasonically mixed for about 10 minutes. The supernatant is then removed to obtain large-diameter mica sheets with a transverse size of 20-100 μm. The large-diameter mica sheets are then ball milled for 3 days to obtain small-diameter mica sheets with a transverse size of 1-10 μm. It is determined that the average value d50 of the transverse size of the large-diameter mica sheets is in the range of 30-40 μm, and the average value d50 of the transverse size of the small-diameter mica sheets is in the range of 2-5 μm.

[0065] The prepared multi-scale two-dimensional mica sheet layer modified anti-aging PVC profile is measured for the degree of ultraviolet aging on an ultraviolet aging tester. The color change ΔE reflects the color change of the profile in the ultraviolet aging chamber, and the smaller the ΔE value, the better the ultraviolet resistance of the material.

[0066] Example 1

[0067] A) The mica sheets of different sizes are pretreated at 800°C for 2 hours before mixing. The large-diameter mica sheets and the small-diameter mica sheets are mixed in a mass ratio of 2:1 to obtain a multi-scale mica sheet powder. The large-diameter mica sheets have a transverse size of 20-100 μm and a d50 of 30-40 μm, and the small-diameter mica sheets have a transverse size of 1-10 μm and a d50 of 2-5 μm.

[0068] B) The PVC general profile ingredients used (specifically composed of PVC 100 parts, environmental protection stabilizer 3.5 parts, titanium white 5 parts, impact resistance ACR modifier 5 parts, impact resistance CPE modifier 5 parts, processing aid 1 part, filler 6 parts, lubricating regulator 0.02 parts, and color modifier 0.01 parts) are dried to 50-70°C before mixing with the mica;

[0069] C) mixing and dispersing the multi-scale mica flake powder obtained in step A) and the PVC general profile powder obtained in step B) by planetary rotation-revolution stirring, wherein the multi-scale mica flake powder accounts for 10% of the total profile mass percentage;

[0070] D) melting the PVC modified raw material obtained in step C) by a high temperature mixer at 185-205°C, and pressing by a press at a pressure of 1500 bar and a holding pressure of 1000 bar to form a multi-scale two-dimensional mica flake layer modified aging-resistant PVC profile after cooling.

[0071] Figure 1 A micrograph of the large flake diameter mica prepared by peeling from the mica mineral in this example was obtained by observation under a field emission scanning electron microscope;

[0072] Figure 2 The particle size distribution of the large flake diameter mica in this example was obtained by testing with a model of American Microtrac S3500 laser particle size analyzer, and the transverse size distribution range was 20-100 μm;

[0073] Figure 3 A micrograph of the small flake diameter mica prepared by peeling from the mica mineral in this example was obtained by observation under a field emission scanning electron microscope;

[0074] Figure 4 The particle size distribution of the small flake diameter mica in this example was obtained, and the transverse size distribution range was 1-10 μm;

[0075] Figure 5 A micrograph of the multi-scale mica prepared by mixing the large flake diameter mica flake and the small flake diameter mica flake in a ratio of 2:1 according to the formulation amount in this example can be seen that the large flake diameter mica flake and the small flake diameter mica flake are uniformly distributed, and there is no obvious agglomeration phenomenon;

[0076] Figure 6 A micrograph of the multi-scale two-dimensional mica flake layer modified aging-resistant PVC profile prepared in this example can be seen that the large flake diameter mica flake and the small flake diameter mica flake and the PVC matrix are well combined and uniformly dispersed, and obvious orientation can be observed, which is beneficial to the improvement of the aging resistance of the material;

[0077] Figure 7 The multi-scale two-dimensional mica flake layer modified aging-resistant PVC profile prepared in this example was tested under an ultraviolet accelerated aging box for 200 hours, and the color change rate ΔE was 8.83908.

[0078] Example 2

[0079] A) After the mica flakes of different flake diameters are pretreated at 800°C for 2 hours (other processes are the same as in Example 1), the large flake diameter mica flakes and the small flake diameter mica flakes are mixed at a mass ratio of 1:1 to obtain a multi-scale mica flake powder, wherein the large flake diameter mica flakes have a lateral size of 20 μm to 100 μm and a d50 of 30 to 40 μm, and the small flake diameter mica flakes have a lateral size of 1 μm to 10 μm and a d50 of 2 to 5 μm.

[0080] B) The PVC general profile ingredients (specifically, the ingredients are composed of 100 parts of PVC, 3.5 parts of an environmental stabilizer, 5 parts of titanium white, 5 parts of an impact-resistant ACR modifier, 5 parts of an impact-resistant CPE modifier, 1 part of a processing aid, 6 parts of a filler, 0.02 parts of a lubricating regulator, and 0.01 parts of a color modifier) are dried to 50 to 70°C before being mixed with the mica;

[0081] C) The multi-scale mica flake powder obtained in step A) and the PVC general profile powder obtained in step B) are mixed and dispersed by planetary rotation and revolution stirring, wherein the multi-scale mica flake powder accounts for 10% of the total profile mass percentage;

[0082] D) The PVC modified raw material obtained in step C) is high-temperature melted by a mixing mill at 185 to 205°C, and is pressed on a tablet press at a pressing pressure of 1500 bar and a holding pressure of 1000 bar, and is cooled to form a multi-scale two-dimensional mica flake layer modified aging-resistant PVC profile.

[0083] Figure 8 The multi-scale two-dimensional mica flake layer modified aging-resistant PVC profile prepared for this example is tested in a UV accelerated aging box for 200 hours, and the color change rate ΔE is 9.70314.

[0084] Example 3

[0085] A) After the mica flakes of different flake diameters are pretreated at 800°C for 2 hours (other processes are the same as in Example 1), the large flake diameter mica flakes and the small flake diameter mica flakes are mixed at a mass ratio of 1:2 to obtain a multi-scale mica flake powder, wherein the large flake diameter mica flakes have a lateral size of 20 μm to 100 μm and a d50 of 30 to 40 μm, and the small flake diameter mica flakes have a lateral size of 1 μm to 10 μm and a d50 of 2 to 5 μm.

[0086] B) The PVC general profile ingredients (specifically, the ingredients are composed of 100 parts of PVC, 3.5 parts of an environmental stabilizer, 5 parts of titanium white, 5 parts of an impact-resistant ACR modifier, 5 parts of an impact-resistant CPE modifier, 1 part of a processing aid, 6 parts of a filler, 0.02 parts of a lubricating regulator, and 0.01 parts of a color modifier) are dried to 50 to 70°C before being mixed with the mica;

[0087] C) The multi-scale mica powder obtained in step A) and the PVC general profile powder obtained in step B) are mixed and dispersed by planetary rotation and revolution stirring, wherein the multi-scale mica powder accounts for 10% of the total profile mass percentage;

[0088] D) The PVC modified raw material obtained in step C) is high-temperature melted by a mixing mill at 185-205°C, and is pressed by a tablet press at a pressure of 1500 bar and a pressure maintaining of 1000 bar, and is cooled to form a multi-scale two-dimensional mica sheet layer modified aging-resistant PVC profile.

[0089] Figure 9 The multi-scale two-dimensional mica sheet layer modified aging-resistant PVC profile prepared in the example is tested in a UV accelerated aging box for 200 hours, and the color change rate ΔE is 9.64151.

[0090] Comparative Example 1

[0091] A) The PVC general profile ingredients (the specific ingredients are composed of PVC 100 parts, environment-friendly stabilizer 3.5 parts, titanium white powder 5 parts, impact-resistant ACR modifier 5 parts, impact-resistant CPE modifier 5 parts, processing aid 1 part, filler 6 parts, lubricating regulator 0.02 parts, and color adjusting agent 0.01 parts) are dried to 50-70°C before mixing with mica;

[0092] B) The PVC general profile powder obtained in step A) and the large-diameter mica powder (the same as the large-diameter mica sheet obtained in Example 1) are mixed and dispersed by planetary rotation and revolution stirring, wherein the large-diameter mica powder accounts for 10% of the total profile mass percentage;

[0093] C) The PVC mixed raw material obtained in step B) is high-temperature melted by a mixing mill at 185-205°C, and is pressed by a tablet press at a pressure of 1500 bar and a pressure maintaining of 1000 bar, and is cooled to form a large-diameter mica modified aging-resistant PVC profile.

[0094] Figure 10 The PVC profile prepared in the comparative example is tested in a UV accelerated aging box for 200 hours, and the color change rate ΔE is 9.83628.

[0095] Comparative Example 2

[0096] A) The PVC general profile ingredients (the specific ingredients are composed of PVC 100 parts, environment-friendly stabilizer 3.5 parts, titanium white powder 5 parts, impact-resistant ACR modifier 5 parts, impact-resistant CPE modifier 5 parts, processing aid 1 part, filler 6 parts, lubricating regulator 0.02 parts, and color adjusting agent 0.01 parts) are dried to 50-70°C before mixing with mica;

[0097] B) The PVC general profile powder obtained in step A) and the small flake mica powder (the same as the small flake mica obtained in example 1) were mixed and dispersed by planetary rotation and revolution stirring, wherein the small flake mica powder accounted for 10% of the total profile mass percentage;

[0098] C) The PVC mixed raw material obtained in step B) was high-temperature melted by a mixer at 185-205°C, and was pressed by a tablet press at a pressing pressure of 1500 bar and a holding pressure of 1000 bar, and was cooled to form a small flake mica modified aging-resistant PVC profile.

[0099] Figure 11 The PVC profile prepared for the present comparative example was tested in a UV accelerated aging box for 200 hours, and the color change rate ΔE was 9.76401.

[0100] From the results of the above examples and comparative examples, it can be seen that the aging resistance of the PVC profile obtained by adding large flake mica alone or small flake mica alone in the PVC general profile powder is not as good as that of the PVC profile obtained by adding large flake mica and small flake mica, especially when the mass ratio of large flake mica and small flake mica is 2:1, the color change rate ΔE is 8.83908, which is much smaller than the color change rate ΔE of examples 2-3 and comparative examples 1 and 2. This significant change in color change rate ΔE is beyond the expectation of ordinary skilled persons in the art. Without being bound by any theory, the applicant believes that this may be because the obtained multi-scale two-dimensional mica sheet layer modified aging-resistant PVC profile has a micro-scale multi-scale structure, and the large flake mica provides excellent anti-UV aging performance in the whole material system, and the small flake mica fills the pores and defects in the large flake mica system, and the synergistic effect gives the aging-resistant profile excellent anti-UV aging effect.

[0101] Industrial applicability

[0102] The multi-scale two-dimensional mica sheet layer modified aging-resistant PVC profile obtained by the present application has a micro-scale multi-scale structure, wherein the large flake mica and the small flake mica synergistically give the aging-resistant profile excellent anti-UV aging effect in the whole material system, and the method provided by the present application for preparing the aging-resistant PVC profile with high added value from natural two-dimensional mica sheet layer has the advantages of simple preparation process, short process, high temperature resistance, good stability, excellent anti-UV aging effect, etc. Therefore, the present application has high application and promotion value.

Claims

1. A PVC profile, the PVC profile comprising general PVC profile materials, large-diameter mica sheets with a transverse dimension of 20μm to 100μm, and small-diameter mica sheets with a transverse dimension of 1μm to 10μm, wherein the large-diameter mica sheets and the small-diameter mica sheets are composited in sheet form in the PVC profile.

2. The PVC profile according to claim 1, wherein, The mass ratio of the large-diameter mica sheet to the small-diameter mica sheet is in the range of 0.5 to 2.

5.

3. The PVC profile according to claim 1, wherein, The PVC general-purpose profile material comprises the following components: 100 PVC units 3.5-6 parts of environmentally friendly stabilizer. 5-12 parts titanium dioxide, 4-7 parts of impact-resistant ACR modifier, 4-8 parts of impact-resistant CPE modifier Processing aids 0.5-2 parts, 5-12 parts of filler Lubricant 0.02 to 2.0 parts, and 0 to 0.1 parts of colorant.

4. The PVC profile according to claim 1, wherein, The PVC general-purpose profile material is a PVC general-purpose profile material that has undergone pretreatment at 600℃~800℃.

5. The PVC profile according to claim 1, wherein, The lateral dimension d50 of the large-diameter mica sheet is in the range of 30 to 40 μm, while the lateral dimension d50 of the small-diameter mica sheet is in the range of 2 to 5 μm.

6. The PVC profile according to claim 1, wherein, The total content of the large-diameter mica sheets and the small-diameter mica sheets is less than 15 wt% of the total content of the PVC general-purpose profile material and the mica sheets.

7. A method for preparing the PVC profile according to any one of claims 1-6, the method comprising the following steps: a) Processing sericite minerals yields large-diameter mica flakes with lateral dimensions of 20 μm to 100 μm and small-diameter mica flakes with lateral dimensions of 1 μm to 10 μm; b) Mix the large-diameter mica sheets and the small-diameter mica sheets according to the formula amount, and then mix them with the PVC general-purpose profile ingredients to obtain an initial mixture, wherein the PVC general-purpose profile ingredients are dried to 50-70°C before being mixed with mica. c) The initial mixture is compressed and molded to obtain a multi-scale mica sheet composite PVC profile.

8. The method according to claim 7, wherein, The sericite mineral mentioned in step a) includes: i) Pre-treat the sericite mineral at 600℃~800℃ and hold it at the highest temperature. ii) Then, the mica obtained in step i) and deionized water are ultrasonically mixed at a mass ratio of 0.01 to 0.02, and after suspension and sedimentation, large-diameter mica flakes are obtained. iii) The large-diameter mica flakes are then ball-milled to obtain small-diameter mica flakes.

9. The method according to claim 7, wherein, Before being mixed into the PVC general-purpose profile ingredients, the large-diameter mica flakes and small-diameter mica flakes in step b) are mixed at a mass ratio of 0.5 to 2.

5. After being shaken and dispersed evenly, they are then mixed evenly with the PVC general-purpose profile ingredients to obtain a mixed powder.

10. The method according to claim 7, wherein, Step c) includes: melting the mixed powder obtained in step b) in a mixer at 185-205°C, and then pressing it into shape on a tablet press at a pressure of 1500-1800 bar and a holding pressure of 800-1000 bar, thereby producing a multi-scale two-dimensional mica sheet modified aging-resistant PVC profile.

Images