A HIPS composite material and its preparation method and application

Abstract

The present invention discloses a HIPS composite material, which comprises the following components by weight: 85-90 parts of HIPS, 5.5-9.5 parts of star-shaped SBS block copolymer, and 4-6 parts of mineral oil. The present invention can significantly improve the anti-drop performance of the composite material by adding a specific amount of star-shaped SBS block copolymer and a specific type of mineral oil to HIPS, and can also significantly improve the tiger stripes generated during injection molding.

Description

Technical Field

[0001] The invention relates to the technical field of polymer materials, and in particular to a HIPS composite material and a preparation method and application thereof. Background Art

[0002] HIPS material has good fluidity and good deformation resistance after injection molding, and can be used in a wide range of fields. Since the shell box needs to load and transport ammunition, the overall size is large, so the material needs to have good fluidity. At the same time, since the ammunition needs to be protected, the anti-drop performance of the shell box is particularly important. Although the current conventional HIPS material has certain impact resistance, it is difficult to meet the anti-drop requirements.

[0003] At present, the toughening and modification of HIPS materials is mainly carried out through the blending and toughening of SBS block polymers. However, in order to improve the toughness, a high content of SBS block copolymers is usually added. However, the high content of SBS block copolymers is prone to thermal oxidation during the high temperature blending and modification process, resulting in rubber cross-linking, poor fluidity, cross-linked bumps on the surface of the material, and tiger stripes after injection molding. At the same time, the toughness of the material does not reach a good level. Summary of the invention

[0004] The object of the present invention is to overcome the above technical defects and provide a HIPS composite material with good anti-drop performance and no tiger-skin pattern appearance defects after injection molding.

[0005] The present invention is achieved through the following technical solutions:

[0006] A HIPS composite material, comprising the following components in parts by weight:

[0007] HIPS 85-90 copies;

[0008] 5.5-9.5 parts of star-shaped SBS block copolymer;

[0009] 4-6 parts of mineral oil;

[0010] Wherein, the kinematic viscosity of the mineral oil is 90-99.9 mm 2 / s, open flash point ≥240℃;

[0011] In the star-shaped SBS block copolymer, the weight content of the butadiene segment is in the range of 54-71wt%;

[0012] The weight content of the rubber phase in the HIPS is in the range of 8-12wt%.

[0013] The rubber in HIPS refers to the butadiene segment therein, and the rubber content in HIPS can be tested by nuclear magnetic hydrogen spectrum. In the technical solution of the present invention, the weight content of the butadiene segment in the star-shaped SBS block copolymer is in the range of 55wt%, 56wt%, 57wt%, 58wt%, 59wt%, 60wt%, 61wt%, 62wt%, 63wt%, 64wt%, 65wt%, 66wt%, 67wt%, 68wt%, 69wt%, 70wt%, 71wt%. The weight content of the rubber phase in HIPS ranges from 8.2 wt%, 8.4 wt%, 8.6 wt%, 8.7 wt%, 8.8 wt%, 9.0 wt%, 9.2 wt%, 9.4 wt%, 9.6 wt%, 9.8 wt%, 10. 0 wt%, 10.2 wt%, 10.4 wt%, 10.6 wt%, 10.8 wt%, 11.0 wt%, 11.2 wt%, 11.4 wt%, 11.6 wt%, 11.8 wt%, and 12.0 wt%.

[0014] Among them, the open-mouth flash point is determined by the method of ASTM D92-2012, and the kinematic viscosity is determined by referring to ASTM D445-2015.

[0015] The mineral oil is selected from one or more of paraffin oil and naphthenic oil, preferably naphthenic oil. Compared with paraffin oil, naphthenic oil has better compatibility in the HIPS blended composite material.

[0016] Preferably, the weight content of the rubber phase in the HIPS is in the range of 9-11 wt %.

[0017] Preferably, in the star-shaped SBS block copolymer, the weight content of the butadiene segment is in the range of 58-62 wt %.

[0018] The HIPS has a melt index range of 4-14 g / 10 min, and is measured according to the method of reference standard ASTM D1238-23 under the test conditions of 200° C. and 5 kg.

[0019] The melt index of the star-shaped SBS block copolymer is in the range of 3-10 g / 10 min, and is measured according to the method of reference standard ASTM D1238-23 under the test conditions of 190° C. and 5 kg.

[0020] Without impairing the effects of the present invention, the present invention may further include 0-1 part of antioxidant, 0-1 part of pigment, and 0-2 parts of antistatic agent by weight. The content of HIPS in the HIPS composite material of the present invention is not less than 70wt%.

[0021] The preparation method of the HIPS composite material comprises the following steps: mixing the components uniformly according to the proportion, and extruding and granulating through a twin-screw extruder, wherein the screw temperature ranges from 120 to 210° C. and the rotation speed ranges from 50 to 600 rpm.

[0022] Application of HIPS composite materials to prepare storage box shells.

[0023] The present invention has the following beneficial effects:

[0024] The present invention can significantly improve the anti-drop performance of the composite material by adding a specific amount of star-shaped SBS block copolymer and a specific type of mineral oil to HIPS, and can also significantly improve the tiger stripes produced during injection molding. Specifically, after the star-shaped SBS block copolymer is mixed with a mineral oil of a specific kinematic viscosity, its fluidity is greatly increased, and it plays a good dispersing role in the HIPS blending process. The mineral oil with a higher flash point is retained more during the processing process, which plays a good role in rubber dispersion and promoting material flow, thereby improving the tiger stripes; the HIPS rubber content and the star-shaped SBS butadiene segment content are moderate, and the overall strength of the material is good, and the anti-drop hammer drop impact performance is good; the rubber content in HIPS is too high and / or the star-shaped SBS butadiene segment content is too high, the HIPS blended composite material fluidity decreases and is prone to tiger stripe appearance defects, the rubber content is too low and / or the star-shaped SBS butadiene segment content is too low, and the matrix is ​​soft and easy to deform and crack when it falls. Compared with the linear structure SBS, the star-shaped structure SBS has a better dispersion effect in the HIPS blended composite material, and plays an effective drop toughening role. Implementation

[0025] The present invention is described in detail below in conjunction with specific embodiments. The following embodiments will help those skilled in the art to further understand the present invention, but are not intended to limit the present invention in any form. It should be noted that, for those of ordinary skill in the art, several variations and improvements may be made without departing from the concept of the present invention. These all belong to the protection scope of the present invention.

[0026] The sources of raw materials used in the present invention are as follows:

[0027] HIPS resin was prepared by referring to the method described in the literature (Synthesis, Modification and Characterization of High Impact Polystyrene I. Effect of Agitation Conditions on Impact Properties [J]. Petrochemicals, 2002(09): 725-729.) to obtain HIPS resins with different rubber phase weight contents but similar polymerization degrees by controlling the amount of polybutadiene chain segments added;

[0028] HIPS-1: The weight content of the rubber phase is 8wt%;

[0029] HIPS-2: The weight content of the rubber phase is 9wt%;

[0030] HIPS-3: The weight content of the rubber phase is 11wt%;

[0031] HIPS-4: The weight content of the rubber phase is 12wt%;

[0032] HIPS-5: The weight content of the rubber phase is 6wt%;

[0033] HIPS-6: The weight content of the rubber phase is 15wt%.

[0034] The star-shaped SBS block copolymer was prepared by referring to the method described in the literature (Xu Lingyun, Xie Jingwei, Tang Dexian, et al. Research on SBS Thermoplastic Elastomer - Star-shaped SBS Block Copolymer [J]. Journal of Fudan University (Natural Science Edition), 1981(02): 139-147. and Synthetic Rubber Industry Handbook [M]. Lanzhou Chemical Industry Company; Liu Dahua, chief editor. Chemical Industry Press. 1991: 1030-1031.) to obtain star-shaped SBS block copolymers with different butadiene chain segment weight contents but similar polymerization degrees; the obtained products were:

[0035] Star-shaped SBS block copolymer-1 (hereinafter referred to as star-shaped SBS-1): the weight content of butadiene segment is 55wt%;

[0036] Star-shaped SBS block copolymer-2 (hereinafter referred to as star-shaped SBS-2): the weight content of butadiene segment is 58wt%;

[0037] Star-shaped SBS block copolymer-3 (hereinafter referred to as star-shaped SBS-3): the weight content of butadiene segment is 62wt%;

[0038] Star-shaped SBS block copolymer-4 (hereinafter referred to as star-shaped SBS-4): the weight content of butadiene segment is 70wt%;

[0039] Star-shaped SBS block copolymer-5 (hereinafter referred to as star-shaped SBS-5): the weight content of butadiene segment is 50wt%;

[0040] Star-shaped SBS block copolymer-6 (hereinafter referred to as star-shaped SBS-6): the weight content of butadiene segment is 75wt%;

[0041] The linear SBS block copolymer was prepared by referring to the method described in the literature (Synthetic Rubber Industry Handbook [M]. Lanzhou Chemical Industry Company; Liu Dahua, Chemical Industry Press, 1991: 1030-1031.) to obtain linear SBS block copolymers with different butadiene segment weight contents; the following were prepared:

[0042] Linear SBS block copolymer A: The weight content of butadiene segments is 55 wt%.

[0043] Linear structure SBS block copolymer B: butadiene segment weight content is 70wt%;

[0044] Paraffin oil-1: 50# paraffin oil, kinematic viscosity 50 mm 2 / s, flash point is 230℃, commercially available.

[0045] Paraffin oil-2: 90# paraffin oil, kinematic viscosity 90 mm 2 / s, flash point is 250℃, commercially available.

[0046] Naphthenic oil-1: 10# naphthenic oil, kinematic viscosity is 10 mm 2 / s, flash point is 140℃, commercially available.

[0047] Naphthenic oil-2: 50# naphthenic oil, kinematic viscosity 50 mm 2 / s, flash point is 220℃, commercially available.

[0048] Naphthenic oil-3: 90# naphthenic oil, kinematic viscosity 90 mm 2 / s, flash point is 240℃, commercially available.

[0049] Embodiment and comparative example Preparation method of HIPS composite material: Mix all components evenly, extrude and granulate through a twin-screw extruder, the temperature of screw zone 1 to 2 is 120℃-190℃, the temperature of zone 3 to 5 is 200℃-210℃, the temperature of zone 5 to 10 is 200℃-210℃, and the screw speed is 350 rpm-450rpm.

[0050] Various test methods:

[0051] (1) Drop resistance evaluation: In order to evaluate the drop resistance of materials in mass production, a 100 mm × 100 mm × 2 mm square plate is subjected to DuPont impact test; the DuPont impact hammer is 2 kg, and the impact cone head radius is 1 / 8 inch. The drop resistance of the material is evaluated by adjusting the height of the hammer.

[0052] (2) Tiger stripe evaluation: To quantitatively evaluate the tiger stripe of material injection molding, a rectangular injection molding plate mold is used for molding. Each time, a group of samples are compared and evaluated. The same injection molding machine and the same injection molding process parameters are used (a high injection speed is used, which is 90% of the maximum injection speed of the machine. Tiger stripes are more likely to appear at high speeds). The mold temperature is fixed at 70°C. After the mold temperature stabilizes, the tiger stripe evaluation test is started, and the maximum size of the tiger stripe is counted based on the surface of the molded rectangular plate.

[0053] Table 1: Content of each component of HIPS composite material (parts by weight) and test results

[0054] Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 HIPS-1 85 88 90 HIPS-2 85 HIPS-3 85 HIPS-4 85 Star SBS-1 9 9 9 9 7 6 Naphthenic Oil-3 6 6 6 6 5 4 Anti-drop height cm 81 93 100 105 92 91 Tiger skin size cm 0 0 0 0.5 0 0

[0055] It can be seen from Examples 1-4 that, under the preferred HIPS rubber content, the advantage of no tiger stripes can be achieved, and the drop resistance height can also reach more than 90 cm.

[0056] Table 2: Content of each component of HIPS composite material (parts by weight) and test results

[0057] Example 7 Example 8 Example 9 Example 10 HIPS-1 85 85 85 85 Star SBS-1 9 Star SBS-2 9 Star SBS-3 9 Star Type SBS-4 9 Naphthenic Oil-3 6 6 6 Paraffin oil-2 6 Anti-drop height cm 85 98 108 72 Tiger skin size cm 0 0 0.3 0.6

[0058] It can be seen from Examples 1 / 7-9 that the preferred star-shaped SBS butadiene content can achieve the advantage of no tiger stripes, and the drop resistance height can also reach more than 85 cm.

[0059] Table 3: Content of each component of HIPS composite material (parts by weight) and test results

[0060] Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 HIPS-1 85 85 HIPS-5 85 HIPS-6 85 Star SBS-1 9 9 Star Type SBS-5 9 Star Type SBS-6 9 Naphthenic Oil-3 6 6 6 6 Anti-drop height cm 50 115 68 118 Tiger skin size cm 0 1.5 0 2.3

[0061] Comparative Examples 1-4 show that when the rubber content or the star-shaped SBS butadiene chain content in HIPS is too low, the processing performance is good but the drop resistance is insufficient. When the rubber content or the star-shaped SBS butadiene chain content in HIPS is too high, the processing performance is poor.

[0062] Table 4: Content of each component of HIPS composite material (parts by weight) and test results

[0063] Comparative Example 5 Comparative Example 6 Comparative Example 7 Comparative Example 8 Comparative Example 9 Comparative Example 10 HIPS-1 85 85 85 85 85 85 Star SBS-1 9 9 9 9 Linear SBS-A 9 Linear SBS-B 9 Naphthenic Oil-3 6 6 Naphthenic Oil-1 6 Naphthenic Oil-2 6 Paraffin oil-1 6 Anti-drop height cm 74 78 76 43 23 38 Tiger skin size cm 2.5 1.3 1.4 7.6 1.6 4.1

[0064] It can be seen from Comparative Examples 5-7 that the kinematic viscosity of the mineral oil is too low, which not only results in poor anti-drop performance but also poor processing fluidity.

[0065] It can be seen from Comparative Examples 9-10 that the use of linear SBS not only has poor anti-drop performance but also poor processing fluidity.

Claims

1. A HIPS composite material, characterized in that: By weight, it includes the following components: HIPS 85-90 copies; 5.5-9.5 parts of star-shaped SBS block copolymer; 4-6 parts of mineral oil; Wherein, the kinematic viscosity of the mineral oil is 90-99.9 mm 2 / s, open flash point ≥240℃; The weight content of the rubber phase in the HIPS is in the range of 8-12wt%; In the star-shaped SBS block copolymer, the weight content of the butadiene segment is in the range of 54-71wt%; The mineral oil is selected from one or more of paraffin oil and naphthenic oil; The HIPS content in the HIPS composite material is not less than 70wt%.

2. The HIPS composite material according to claim 1, characterized in that: The mineral oil is naphthenic oil.

3. The HIPS composite material according to claim 1, characterized in that: The weight content of the rubber phase in the HIPS is in the range of 9-11 wt %.

4. The HIPS composite material according to claim 1, characterized in that: In the star-shaped SBS block copolymer, the weight content of the butadiene segment is in the range of 58-62wt%.

5. The HIPS composite material according to claim 1, characterized in that: The melting index range of the HIPS is 4-14 g / 10 min, and the test conditions are 200° C. and 5 kg.

6. The HIPS composite material according to claim 1, characterized in that: The melt index range of the star-shaped SBS block copolymer is 3-10 g / 10 min, and the test conditions are 190° C. and 5 kg.

7. The HIPS composite material according to claim 1, characterized in that: By weight, it also includes 0-1 part of antioxidant, 0-1 part of pigment and 0-2 parts of antistatic agent.

8. The method for preparing the HIPS composite material according to any one of claims 1 to 7, characterized in that: The method comprises the following steps: mixing the components uniformly according to the proportion, and extruding and granulating the components through a twin-screw extruder, wherein the screw temperature ranges from 120 to 210° C. and the rotation speed ranges from 50 to 600 rpm.

9. Use of the HIPS composite material according to any one of claims 1 to 7, characterized in that: Used to prepare storage box shells.