Semi-dull material and preparation method thereof

Abstract

The invention relates to the field of high polymer materials, and particularly discloses a semi-dull material and a preparation method thereof. According to the semi-dull material, polypropylene and polylactic acid are used as main raw materials, maleic anhydride modified polypropylene is used as a compatilizer, and the crystal morphology between polylactic acid and polypropylene is adjusted, so that the proportion of whole microcrystals of the semi-dull material is high, crystal regions and amorphous regions are mutually and uniformly interspersed, the light transmittance of the semi-dull material is high, and meanwhile, the haze of the semi-dull material is not influenced; and the semi-dull material presents a transparent and matte high-grade texture.

Description

Technical Field

[0001] The present application relates to the technical field of polymer materials, and more specifically, to a semi-matt material and a preparation method thereof. Background Art

[0002] Semi-matt material is a polymer material formed by adding a certain amount of matting agent and a small amount of additives to the polyolefin material as the main raw material. The semi-matt material is formed into a semi-matt functional film after melt extrusion and biaxial stretching. The "sea-island" structure of the matting agent forms an uneven surface on the surface of the functional film. Therefore, the surface roughness of the semi-matt functional film is higher than that of the transparent base film, and light is diffusely reflected on the semi-matt functional film.

[0003] The haze of the semi-matt functional film is controlled between 15% and 50%. The uniformity of the "sea-island" concave-convex structure has a great influence on the haze, clarity, gloss and other related optical properties of the semi-matt functional film. The semi-matt functional film can be attached to the packaging of electronic products and daily necessities by means of hot pressing, electrostatic attachment, etc. to enhance the texture of the product. However, the visual effect of the semi-matt functional film is limited. The reason is that the increase in haze depends on the increase in the roughness of the material surface or the enhancement of internal light scattering. However, the increase in surface roughness will cause the reflection and refraction of light, thereby reducing the transmittance. The optical properties of haze and transmittance restrict each other, and it is difficult to achieve the simultaneous improvement of haze and gloss. Summary of the invention

[0004] In order to solve the problem that the haze and transmittance of a semi-matt functional film are difficult to improve simultaneously, the present application provides a semi-matt material and a preparation method thereof.

[0005] In the first aspect, the present application provides a semi-matte material, which adopts the following technical solution:

[0006] A semi-matte material, composed according to the following weight percentages:

[0007]

[0008] The melt flow rate of polypropylene is controlled at 2.8-4.0 g / 10 min, the melt flow rate of polylactic acid is controlled at 5.0-7.0 g / 10 min, and the melt flow rate of maleic anhydride modified polypropylene is controlled at 4.0-6.0 g / 10 min.

[0009] Furthermore, the melt flow rate of the polypropylene is controlled at 3.0 to 4.0 g / 10 min, and the glass transition temperature of the polypropylene is controlled at -8.4 to 0.6°C.

[0010] Furthermore, the melt flow rate of the polylactic acid is controlled at 5.0-6.0 g / 10 min, and the glass transition temperature of the polylactic acid is controlled at 55-58.4°C.

[0011] Furthermore, the melt flow rate of the maleic anhydride modified polypropylene is controlled at 4.0-5.5 g / 10 min, and the glass transition temperature of the maleic anhydride modified polypropylene is controlled at 42.7-43.6°C.

[0012] Furthermore, the weight percentage of the polypropylene is 65%.

[0013] Furthermore, the weight percentage of the polylactic acid is 30%.

[0014] Furthermore, the weight percentage of the maleic anhydride modified polypropylene is 4.5%.

[0015] Furthermore, the auxiliary agent is hydrotalcite-modified sodium dodecylbenzene sulfonate.

[0016] Furthermore, the weight percentage of the hydrotalcite-modified sodium dodecyl sulfate is 0.5%.

[0017] In a second aspect, the present application provides a method for preparing a semi-matt material, using the following technical solution:

[0018] A method for preparing a semi-matt material comprises the following steps:

[0019] Premixing of raw materials: premixing polypropylene, polylactic acid, maleic anhydride modified polypropylene and additives according to weight percentage to obtain premixed materials;

[0020] Co-extrusion granulation: Add the premixed material into a twin-screw extruder, extrude and cool to obtain semi-matte particles.

[0021] In summary, this application has at least the following advantages:

[0022] 1. This application selects polypropylene and polylactic acid as the main raw materials, adds maleic anhydride grafted polypropylene as a compatibilizer, and adds additives such as nucleating agents and antistatic agents to adjust the crystal morphology between polylactic acid and polypropylene, so that the overall microcrystal ratio of the semi-matt material is high, the crystalline area and the amorphous area are evenly interspersed with each other, the semi-matt material has a high transmittance, and the haze of the semi-matt material is not affected;

[0023] Polylactic acid has the property of biodegradability and has a large difference in crystallinity from polypropylene. Under the regulation of nucleating agent, the crystallization speed of polylactic acid increases, and the crystallization rates of polylactic acid and polypropylene are fast in the crystallization stage, the size of spherulites is small, and the gloss of the semi-matt film is almost unaffected; maleic anhydride grafted polypropylene contains polar maleic anhydride groups, and the maleic anhydride groups promote the compatibility of polylactic acid and polypropylene through intermolecular forces, causing polypropylene to be evenly distributed in polylactic acid, and the crystalline and amorphous regions are evenly interspersed with each other, and the haze inside the semi-matt material increases; the semi-matt material can have both high light transmittance and haze; the semi-matt material presents a high-grade texture of transparency and matte.

[0024] 2. In the present application, the melt flow rate and glass transition temperature of polypropylene, polylactic acid and maleic anhydride modified polypropylene are adjusted so that the melt flow rates of polypropylene, polylactic acid and maleic anhydride modified polypropylene are close in a step-by-step manner and the glass transition temperatures are close, which is helpful for stretching and shaping the semi-matt material after melting.

[0025] 3. In this application, the amount of maleic anhydride modified polypropylene is adjusted to balance the haze and transmittance of the semi-matte material; when the amount of maleic anhydride modified polypropylene is too high, maleic anhydride modified polypropylene is easy to cause the polar groups of the blending system to aggregate, which in turn reduces the compatibility between polypropylene and polylactic acid, and the microscopic phase distribution of the blending system is uneven, the haze increases significantly, the transmittance decreases significantly, the matting effect is poor, and the semi-matte material appears partially white and foggy. When the amount of maleic anhydride modified polypropylene is too low, the compatibility between polypropylene and polylactic acid is poor, and the haze of the semi-matte material is low.

[0026] 4. In this application, sodium dodecylbenzene sulfonate is selected to be intercalated and modified in hydrotalcite to obtain hydrotalcite-modified sodium dodecyl sulfate. The hydrotalcite-modified sodium dodecylbenzene sulfonate can act as a nucleating agent and an antistatic agent, and has both antistatic properties and can promote rapid crystallization of polypropylene and polylactic acid. Under the premise of not affecting the haze of the semi-matte material, the spherulite size is small, which increases the light transmittance of the semi-matte material. At the same time, the hydrotalcite-modified sodium dodecylbenzene sulfonate has good dispersion properties, and the hydrotalcite increases the cross-linking sites of the blending system, optimizes the mechanical properties of the polylactic acid and polypropylene blending system, and gives the semi-matte material higher tensile strength and elongation at break.

[0027] 5. In the present application, the raw materials are subjected to steps such as premixing and melt blending, so that the polypropylene and polylactic acid blending system is evenly mixed, the production steps of the semi-matt material are simple, and the product performance is stable. DETAILED DESCRIPTION

[0028] The present application is further described in conjunction with the following examples, comparative examples and test data.

[0029] Unless otherwise specified, the sources of raw materials used in the preparation examples, embodiments and comparative examples of this application are as follows:

[0030] Polypropylene:

[0031] Grade: F1002B, melt flow rate is 2.8g / 10min, glass transition temperature is -10.3℃;

[0032] Grade: F280T, melt flow rate is 3.0g / 10min, glass transition temperature is -8.4℃;

[0033] Grade: T36F, melt flow rate is 4.0g / 10min, glass transition temperature is 0.6℃;

[0034] Grade: F800E, melt flow rate is 8.0g / 10min, glass transition temperature is 2.5℃;

[0035] The test conditions for melt flow rate were 230°C, 2.16 kg;

[0036] Polylactic acid:

[0037] Grade: Ingeo TM Biopolymer 4032D, melt flow rate 5.0g / 10min, glass transition temperature 55°C;

[0038] Grade: Ingeo TM Biopolymer 4044D, melt flow rate 6.0g / 10min, glass transition temperature 58.4℃

[0039] Grade: Ingeo TM Biopolymer 4043D, melt flow rate 7.0g / 10min, glass transition temperature 56.6℃;

[0040] Grade: Ingeo TM Biopolymer 6100D, melt flow rate is 24.0g / 10min, glass transition temperature is 61.9℃;

[0041] The test conditions for melt flow rate were 230°C, 2.16 kg;

[0042] Hydrotalcite: MDL number: MFCD01746913, from Merck Chemicals.

[0043] Preparation Example A-1

[0044] Maleic anhydride modified polypropylene is prepared according to the following steps:

[0045] Polypropylene F1002B, dicumyl peroxide and maleic anhydride were mixed in a molar ratio of 1:0.01:0.2 and added into a mixer on a torque rheometer. The temperature was set to 200°C and the reaction time was greater than 10 times the half-life of dicumyl peroxide. The product was taken out, crushed and dried. After rheological property testing, its melt flow rate was 6.0 g / 10 min (230°C, 2.16 kg) and the glass transition temperature was 37.9°C.

[0046] Preparation Example A-2

[0047] Maleic anhydride modified polypropylene is prepared according to the following steps:

[0048] Polypropylene F1002B, dicumyl peroxide and maleic anhydride were mixed in a molar ratio of 1:0.015:0.3 and added into a mixer on a torque rheometer. The temperature was set to 200°C and the reaction time was greater than 10 times the half-life of dicumyl peroxide. The product was taken out, crushed and dried. After rheological property testing, its melt flow rate was 5.5 g / 10 min (230°C, 2.16 kg) and the glass transition temperature was 42.7°C.

[0049] Preparation Example A-3

[0050] Maleic anhydride modified polypropylene is prepared according to the following steps:

[0051] Polypropylene F1002B, dicumyl peroxide and maleic anhydride were mixed in a molar ratio of 1:0.025:0.5 and added into a mixer on a torque rheometer. The temperature was set to 200°C and the reaction time was greater than 10 times the half-life of dicumyl peroxide. The product was taken out, crushed and dried. After rheological property testing, its melt flow rate was 4.0 g / 10 min (230°C, 2.16 kg) and the glass transition temperature was 43.6°C.

[0052] Preparation Example A-4

[0053] Maleic anhydride modified polypropylene is prepared according to the following steps:

[0054] Polypropylene F1002B, dicumyl peroxide and maleic anhydride were mixed in a molar ratio of 1:0.025:0.5 and added into a mixer on a torque rheometer. The temperature was set to 200°C and the reaction time was greater than 10 times the half-life of dicumyl peroxide. The product was taken out, crushed and dried. After rheological property testing, its melt flow rate was 2.2 g / 10 min (230°C, 2.16 kg) and the glass transition temperature was 55.7°C.

[0055] Preparation Example B

[0056] Hydrotalcite-modified sodium dodecylbenzene sulfonate is prepared according to the following steps:

[0057] Dissolve hydrotalcite in water to prepare a concentration of 1.25 mol·L －1 The reaction liquid was then dissolved in water to prepare 1.25 mol·L －1 The reaction liquid and the alkali solution were simultaneously added dropwise to a concentration of 0.1 mol·L －1 The sodium dodecylbenzene sulfonate solution was heated to 80°C, the pH value of the reaction system was controlled to be 9-10, and the temperature of the reaction system was controlled to be 65°C after the dropwise addition was completed. The reaction was crystallized for 24 hours, and then filtered, washed, and dried in an oven to obtain hydrotalcite-modified sodium dodecylbenzene sulfonate.

[0058] Example 1

[0059] A semi-matte material is prepared by preparing the following raw materials according to the following weight percentages:

[0060]

[0061] Follow these steps to make it:

[0062] The polypropylene, polylactic acid, maleic anhydride modified polypropylene and hydrotalcite modified sodium dodecylbenzene sulfonate are vacuum dried to remove moisture and set aside;

[0063] Prepare polypropylene, polylactic acid, maleic anhydride modified polypropylene and hydrotalcite modified sodium dodecylbenzene sulfonate according to weight percentage, add the above raw materials into a high-speed blender, and stir at a speed of 3r / s for 5 minutes to obtain a premixed material;

[0064] The premixed material is added into a twin-screw extruder, the screw speed is controlled to be 60 r / min, the temperature of each zone of the twin-screw extruder is between 200 and 225° C., and semi-matte particles are obtained after extrusion cooling.

[0065] Embodiment 2-4

[0066] A semi-matte material, which is different from Example 1 in that the weight percentages of polypropylene, polylactic acid, maleic anhydride-modified polypropylene and hydrotalcite-modified sodium dodecylbenzene sulfonate are different, as follows:

[0067] In Example 2, polypropylene 65%, polylactic acid 30%, maleic anhydride modified polypropylene (Preparation Example A-1) 4.5% and hydrotalcite modified sodium dodecylbenzene sulfonate 0.5%;

[0068] In Example 3, polypropylene 70%, polylactic acid 25%, maleic anhydride modified polypropylene (Preparation Example A-1) 4.5% and hydrotalcite modified sodium dodecylbenzene sulfonate 0.5%;

[0069] In Example 4, there are 70% polypropylene, 27% polylactic acid, 2.9% maleic anhydride-modified polypropylene (Preparation Example A-1) and 0.1% hydrotalcite-modified sodium dodecylbenzene sulfonate.

[0070] Embodiment 5-7

[0071] A semi-matte material, which is different from Example 2 in that the characteristic parameters of polypropylene, polylactic acid and maleic anhydride modified polypropylene are different, as follows:

[0072] In Example 5, polypropylene F280T is used in place of polypropylene F1002B by weight, and polylactic acid Ingeo TM Biopolymer 4044D replaces polylactic acid Ingeo by weight TM Biopolymer 4043D, using the maleic anhydride modified polypropylene prepared in Preparation Example A-2 in equal weight percentages to replace the maleic anhydride modified polypropylene prepared in Preparation Example A-1;

[0073] In Example 6, polypropylene T36F is used in place of polypropylene F1002B by weight, and polylactic acid Ingeo TM Biopolymer 4032D replaces polylactic acid Ingeo by weight TM Biopolymer 4043D, using the maleic anhydride-modified polypropylene prepared in Preparation Example A-3 in an equal weight percentage to replace the maleic anhydride-modified polypropylene prepared in Preparation Example A-1;

[0074] In Example 7, polypropylene F800E is used in place of polypropylene F1002B by weight, and polylactic acid Ingeo TM Biopolymer 6100D replaces polylactic acid Ingeo by weight TM Biopolymer 4043D, using the maleic anhydride modified polypropylene prepared in Preparation Example A-4 in an equal weight percentage to replace the maleic anhydride modified polypropylene prepared in Preparation Example A-1.

[0075] Comparative Example 1

[0076] A semi-matte material, which is different from Example 1 in that hydrotalcite-modified sodium dodecylbenzene sulfonate is used in an equal weight percentage to replace maleic anhydride-modified polypropylene.

[0077] Comparative Example 2

[0078] A semi-matte material, which differs from Example 1 in that: acrylic acid grafted polypropylene is used in equal parts by weight instead of maleic anhydride grafted polypropylene;

[0079] The acrylic acid grafted polypropylene is sourced from Wuxi Yiyuan New Materials, and has a melt flow rate of 25g / 10min.

[0080] Comparative Example 3

[0081] A semi-matte material, which differs from Example 1 in that the weight percentage is different, as follows:

[0082]

[0083] Comparative Example 4

[0084] A semi-matte material, which differs from Example 1 in that the weight percentage is different, as follows:

[0085]

[0086] Performance Testing

[0087] The semi-matt materials prepared in Examples 1-7 and Comparative Examples 1-4 were taken and the semi-matt materials were subjected to an enlarged test to produce semi-matt film samples with a thickness of 15 μm;

[0088] The haze of the semi-matt film sample was tested using a HAM-200 remote haze meter: 10 test points were randomly set on the semi-matt film sample, the maximum haze value and the minimum haze value of the test points were recorded, the haze difference was calculated, and the average haze value was calculated.

[0089] The transmittance of the semi-matt film sample is measured using a transmittance tester.

[0090] The tensile strength and elongation at break of the semi-matt film samples were tested using a film tensile testing machine.

[0091] Table 1. Performance test of semi-matt films obtained in Examples 1-7 and Comparative Examples 1-4

[0092]

[0093]

[0094] in conclusion

[0095] According to the above test data, it can be seen that:

[0096] First, no compatibilizer is added in Comparative Example 1, and the average haze of Comparative Example 1 is low, but the difference is large, indicating that after polypropylene and polylactic acid are blended, the compatibility is poor, and high haze occurs locally. The haze of the semi-matt film is uneven, the transmittance is low, and the product quality is poor.

[0097] Second, acrylic acid grafted polypropylene was added in Comparative Example 2, but as a compatibilizer, its compatibilizing effect was poor, resulting in a decrease in the haze of the semi-matt film and a large haze difference. The matte effect of the semi-matt film prepared in Comparative Example 2 was not as good as that of Example 1.

[0098] Third, the amount of polypropylene added in Comparative Example 3 is too high, the amount of polylactic acid added is too low, and the overall haze of the semi-matte film is low. In Comparative Example 4, the amount of polylactic acid added is too high, the haze of the semi-matte film is too high, the glossiness decreases, and the transmittance of the semi-matte film is low.

[0099] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0100] Moreover, the above-mentioned embodiments only express several implementation methods of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the invention patent. It should be pointed out that for ordinary technicians in this field, several modifications and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be based on the attached claims.

Claims

1. A semi-matte material, characterized in that: According to the following weight percentage composition: The melt flow rate of polypropylene is controlled at 2.8-4.0 g / 10 min, the melt flow rate of polylactic acid is controlled at 5.0-7.0 g / 10 min, and the melt flow rate of maleic anhydride modified polypropylene is controlled at 4.0-6.0 g / 10 min.

2. A semi-matte material as claimed in claim 1, characterized in that: The melt flow rate of the polypropylene is controlled at 3.0 to 4.0 g / 10 min, and the glass transition temperature of the polypropylene is controlled at -8.4 to 0.6°C.

3. A semi-matte material as claimed in claim 1, characterized in that: The melt flow rate of the polylactic acid is controlled at 5.0-6.0 g / 10 min, and the glass transition temperature of the polylactic acid is controlled at 55-58.4° C.

4. A semi-matte material as claimed in claim 1, characterized in that: The melt flow rate of the maleic anhydride modified polypropylene is controlled at 4.0-5.5 g / 10 min, and the glass transition temperature of the maleic anhydride modified polypropylene is controlled at 42.7-43.6° C.

5. The semi-matt material according to claim 1, characterized in that: The weight percentage of the polypropylene is 65%.

6. A semi-matte material as claimed in claim 5, characterized in that: The weight percentage of the polylactic acid is 30%.

7. A semi-matte material as claimed in claim 6, characterized in that: The weight percentage of the maleic anhydride modified polypropylene is 4.5%.

8. The semi-matte material according to claim 1, characterized in that: The auxiliary agent is hydrotalcite-modified sodium dodecylbenzene sulfonate.

9. A semi-matte material as claimed in claim 8, characterized in that: The weight percentage of the hydrotalcite-modified sodium dodecyl sulfate is 0.5%.

10. A method for preparing a semi-matt material according to any one of claims 1 to 9, characterized in that: The steps include: Premixing of raw materials: premixing polypropylene, polylactic acid, maleic anhydride modified polypropylene and additives according to weight percentage to obtain premixed materials; Co-extrusion granulation: Add the premixed material into a twin-screw extruder, extrude and cool to obtain semi-matte particles.

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