Low-mold-scale high-light-black spraying-free material and preparation and processing forming method thereof

Abstract

The invention relates to a low-mold-scale high-gloss black spraying-free material and a preparation and processing forming method thereof. The material comprises the following components in parts by weight: 90-95 parts of high-gloss black resin; 5-10 parts by weight of a low mold scale auxiliary agent; 0.1 to 1 part by weight of an antioxidant; 0.1 to 1 part by weight of a lubricant; the preparation method comprises the following steps: mixing the high-gloss black resin, the low-mold-scale auxiliary agent, the antioxidant and the lubricant, carrying out melt extrusion, and granulating. The obtained material is used for hot working forming at the forming temperature not lower than 190 DEG C. Compared with the prior art, the low-mold-scale additive is added into the high-gloss material, water vapor generated by decomposition of the additive during injection molding is used for cleaning a mold, meanwhile, carbon monoxide / carbon dioxide gas generated during decomposition can carry micromolecule gas degraded by high-gloss resin during injection molding, the devolatilization effect is achieved, and the prepared high-gloss material has the characteristic of low mold scale, and has the advantages of being low in mold scale, high in strength, good in durability and the like. And the highlight effect of the surface of the mold can still be ensured after long-term injection molding.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of high polymer materials, and relates to a low-mold-scale high-gloss-black spray-free material and a preparation and processing forming method thereof. BACKGROUND

[0002] As a substitute for traditional spray piano paint, the high-gloss-black spray-free material can not only simplify the process and reduce the cost, but also be environment-friendly and efficient, and meanwhile, the high-brightness effect of the piano paint can be maintained. The spray-free substitution for spray paint for automobile exterior decoration is also a key direction for cost reduction and research of automobile enterprises in recent years. Through cooperation of the material and the mold, one-step injection molding can be realized, the development efficiency of automobile parts is greatly improved, and the production cycle is shortened.

[0003] The prior art CN116218117A discloses a fingerprint-resistant high-gloss-black PMMA / ASA composition and a preparation method thereof. The composition comprises polymethyl methacrylate, acrylonitrile-acrylate-styrene copolymer, self-cleaning modifier PA-g-MAH and other additives; wherein the mass ratio of the polymethyl methacrylate, the acrylonitrile-acrylate-styrene copolymer and the self-cleaning modifier PA-g-MAH is (50-80):(20-40):(5-10). The preparation method comprises the following steps: mixing the polymethyl methacrylate, the acrylonitrile-acrylate-styrene copolymer, the self-cleaning modifier PA-g-MAH, the antioxidant, the lubricant and the black color powder according to the mass fraction; and blending and granulating the mixture through a double-screw extruder, to obtain the fingerprint-resistant high-gloss-black PMMA / ASA composition after melt extrusion. Compared with the prior art, the technical solution can ensure good compatibility of PA6 / 66-g-MAH and PMMA / ASA resin, and can achieve obvious fingerprint-resistant effect.

[0004] Generally, the high-gloss-black material needs to be matched with a mold with high polishing degree and high mirror surface effect to realize the high-gloss-piano-black effect of the part. However, the high polymer material is prone to degradation to generate small molecules during injection molding, and the small molecules are prone to form mold scale after being deposited on the surface of the mold. When there is too much mold scale, the high-gloss effect of the surface of the part after injection molding is affected, and the part after injection molding cannot meet the requirements. At present, the common solution is to re-polish or clean the mold to meet the re-delivery when the mold scale on the mold affects the normal injection molding quality of the part, which not only increases the production cost, but also affects the production cycle. SUMMARY

[0005] The present application aims to provide a low-mold-fouling high-gloss black spray-free material and a preparation and processing forming method thereof, and aims to solve the technical problem that the existing high molecular material is prone to degradation to generate small molecules and deposit on the mold surface to form mold fouling, thereby affecting the high gloss effect of the product. The present application adds a low-mold-fouling auxiliary agent to the high molecular material, and uses the water vapor generated by thermal decomposition of the low-mold-fouling auxiliary agent in the thermal processing process to achieve the effect of mold self-cleaning, thereby removing the mold fouling deposited on the mold surface. At the same time, the inert gas generated by thermal decomposition can carry out part of the small molecules generated by the degradation of the high gloss resin base material, thereby achieving the effect of devolatilization, and further ensuring the high gloss effect of the product.

[0006] The object of the present application can be achieved by the following technical solutions:

[0007] The first aspect of the present application provides a low-mold-fouling high-gloss black spray-free material, which comprises the following components and weight contents: high-gloss black resin 90-95 parts by weight; low-mold-fouling auxiliary agent 5-10 parts by weight; antioxidant 0.1-1 parts by weight; lubricant 0.1-1 parts by weight.

[0008] The decomposition temperature of the low-mold-fouling auxiliary agent is 200-300 DEG C, and water vapor is generated during decomposition, and CO, CO2 or N2 is also generated.

[0009] In some specific embodiments, the high-gloss black resin is selected from ASA resin (acrylonitrile-styrene-acrylate copolymer) or PMMA / ASA resin (polymethyl methacrylate / acrylonitrile-styrene-acrylate copolymer).

[0010] In some specific embodiments, the low-mold-fouling auxiliary agent is one or more of oxalic acid, formic acid, or cellulose. In some specific embodiments, the antioxidant is selected from at least one of antioxidant 245, antioxidant 1076 or antioxidant 168.

[0011] In some specific embodiments, the lubricant is selected from at least one of silicone powder, pentaerythritol stearate or ethylene bis-stearamide.

[0012] The second aspect of the present application provides a preparation method of the low-mold-fouling high-gloss black spray-free material as described above, which comprises: mixing and melt-extruding the high-gloss black resin, the low-mold-fouling auxiliary agent, the antioxidant and the lubricant, and granulating to obtain.

[0013] In some specific embodiments, the melt-extruding temperature is 170-180 DEG C, and the rotation speed is 400-500 rpm.

[0014] The third aspect of the present application provides a processing forming method of the low-mold-fouling high-gloss black spray-free material as described above, which comprises thermally processing and forming the low-mold-fouling high-gloss black spray-free material.

[0015] In some preferred embodiments, the forming temperature of the thermal processing is not less than 200℃.

[0016] In some specific embodiments, the thermal processing is injection molding.

[0017] Compared with the prior art, the present application has the following beneficial effects. Taking oxalic acid as an example, the following reaction occurs at an injection molding temperature above 200℃:

[0018] C2H2O4→H2O+CO↑+CO2↑

[0019] The present application adds a low-mold-release aid to a high-gloss material, controls the extrusion temperature of the material to be 170-180℃, and controls the thermal processing (injection molding) temperature to be above 200℃. The low-mold-release aid decomposes to generate water vapor and inert gas during the thermal processing at a temperature above 200℃. The inert gas is used to extract part of the small molecules generated by the degradation of the high-gloss resin base material, and the water vapor generated at the same time is used as a cleaning agent at high temperatures to achieve the effect of self-cleaning of the mold. The high-gloss black material prepared can effectively reduce the frequency of manual cleaning or polishing of the mold, and the gloss GU can still be maintained above 94 after 50 continuous injection moldings. Since the above reaction only occurs at a high temperature above 190℃, controlling the extrusion temperature to be 170-180℃ can ensure the stability of the low-mold-release aid, and the thermal processing temperature must be above 200℃ to ensure the thermal stability of the material until the self-cleaning reaction occurs during the thermal processing. DETAILED DESCRIPTION

[0020] The present application will be described in detail below in conjunction with specific examples. The examples are implemented on the premise of the technical solution of the present application, and detailed implementation and specific operation processes are given, but the protection scope of the present application is not limited to the examples below.

[0021] In each of the following examples, if no special raw material reagent or processing technology is indicated, it means that it is a conventional commercially available product or conventional processing technology in the art.

[0022] In the following examples and comparative examples, the high-gloss resin used is a high-gloss ASA resin-777K of the LyondellBasell High Molecular Materials (Shanghai) Co., Ltd., and the melt index thereof under the condition of 220℃ / 10kg is 15g / 10min;

[0023] The high-gloss PMMA / ASA resin is a resin of type M1600 of Shanghai Jinhu Rili Plastic Co., Ltd., and the melt index thereof under the condition of 220℃ / 10kg is 4g / 10min;

[0024] The oxalic acid is a superior product of Shandong Hualu Hengsheng Chemical Co., Ltd., and the purity level thereof is 99.6%;

[0025] Cellulose is microcrystalline cellulose of Huzhou Linghu Xiwang Chemical Co., Ltd., and the content of limited substance is 99.99%;

[0026] Antioxidant is antioxidant 1010 and antioxidant 168 produced by CIBA.

[0027] Lubricant is pentaerythritol stearate PETs of FACI (Zhangjiagang) Co., Ltd.

[0028] The injection molding machine used in the following examples is a 400T injection molding machine of Ningbo Haitian Plastic Machinery Group Co., Ltd.

[0029] The gloss meter used is a Konica Minolta MG-268 type gloss meter, and the test gloss angle is 20°

[0030] Numerical value.

[0031] Example 1

[0032] A low-mold-fouling high-gloss black spray-free material, the preparation method comprising the following steps:

[0033] (1) Take each component: ASA777K 9 kg, oxalic acid 1 kg, antioxidant 1010 0.01 kg, antioxidant 168 0.01 kg, lubricant PETS 0.03 kg.

[0034] (2) After uniformly stirring the weighed composition in a high-speed mixer, the obtained mixture is fed into the main feeding port of a twin-screw extruder; control the temperature of each section of the extruder to be 100℃-120℃-140℃-150℃-170℃-170℃-170℃-160℃-160℃-150℃, and at the same time control the screw speed at 400 rpm, granulation to obtain a low-mold-fouling high-gloss black ASA product. The obtained high-gloss black ASA product is injection molded at 250℃ to obtain the required high-gloss mirror panel (mold polishing 8000 mesh, gloss 100GU, sample size 100*100*3mm), after continuous injection molding of 500 molds, test the gloss of the high-gloss mirror panel and the metal mold.

[0035] Example 2

[0036] A low-mold-fouling high-gloss black spray-free material, the preparation method comprising the following steps:

[0037] (1) Take each component: ASA777K 9.5 kg, oxalic acid 0.5 kg, antioxidant 1010 0.01 kg, antioxidant 168 0.01 kg, lubricant PETS 0.03 kg.

[0038] (2) The weighed composition is uniformly stirred in a high-speed mixer, and the obtained mixture is fed into the main feeding port of a twin-screw extruder; the temperature of each section of the extruder is controlled at 100-120-140-150-170-170-170-160-160-150°C, and the screw rotation speed is controlled at 400 rpm, to granulate the low-fouling high-gloss black ASA product. The obtained high-gloss black ASA product is injection molded into a high-gloss mirror panel (mold polishing 8000 mesh, gloss 100 GU, sample panel size 100*100*3 mm) at 250°C, and the gloss of the high-gloss mirror panel and the metal mold is tested after 500 continuous injection moldings.

[0039] Example 3

[0040] A low-fouling high-gloss black spray-free material, the preparation method thereof comprising the following steps:

[0041] (1) Weigh the components: PMMA / ASA M1600 9.5 kg, oxalic acid 0.5 kg, antioxidant 1010 0.01 kg, antioxidant 168 0.01 kg, and lubricant PETS 0.03 kg.

[0042] (2) The weighed composition is uniformly stirred in a high-speed mixer, and the obtained mixture is fed into the main feeding port of a twin-screw extruder; the temperature of each section of the extruder is controlled at 100-120-140-160-180-180-180-170-160-150°C, and the screw rotation speed is controlled at 400 rpm, to granulate the low-fouling high-gloss black PMMA / ASA product. The obtained high-gloss black ASA product is injection molded into a high-gloss mirror panel (mold polishing 8000 mesh, gloss 100 GU, sample panel size 100*100*3 mm) at 260°C, and the gloss of the high-gloss mirror panel and the metal mold is tested after 500 continuous injection moldings.

[0043] Example 4

[0044] A low-fouling high-gloss black spray-free material, the preparation method thereof comprising the following steps:

[0045] (1) Weigh the components: PMMA / ASA M1600 9.5 kg, microcrystalline cellulose 0.5 kg, antioxidant 1010 0.01 kg, antioxidant 168 0.01 kg, and lubricant PETS 0.03 kg.

[0046] (2) The weighed composition is uniformly stirred in a high-speed mixer, and the obtained mixture is fed into the main feeding port of a twin-screw extruder; the temperature of each section of the extruder is controlled to be 100-120-140-160-180-180-180-170-160-150°C, and the screw speed is controlled to be 400 rpm, to granulate the low-fouling high-gloss black PMMA / ASA product. The obtained high-gloss black ASA product is injection molded at 260°C to obtain the required high-gloss mirror panel (mold polishing 8000 mesh, gloss 100 GU, and the size of the sample panel is 100*100*3 mm). After 500 continuous injection moldings, the gloss of the high-gloss mirror panel and the metal mold is tested.

[0047] Example 5

[0048] A low-fouling high-gloss black spray-free material, the preparation method thereof comprising the following steps:

[0049] (1) Weigh each component: PMMA / ASA M1600 9.5 kg, oxalic acid 0.25 kg, microcrystalline cellulose 0.25 kg, antioxidant 1010 0.01 kg, antioxidant 168 0.01 kg, and lubricant PETS 0.03 kg.

[0050] (2) The weighed composition is uniformly stirred in a high-speed mixer, and the obtained mixture is fed into the main feeding port of a twin-screw extruder; the temperature of each section of the extruder is controlled to be 100-120-140-160-180-180-180-170-160-150°C, and the screw speed is controlled to be 400 rpm, to granulate the low-fouling high-gloss black PMMA / ASA product. The obtained high-gloss black ASA product is injection molded at 260°C to obtain the required high-gloss mirror panel (mold polishing 8000 mesh, gloss 100 GU, and the size of the sample panel is 100*100*3 mm). After 500 continuous injection moldings, the gloss of the high-gloss mirror panel and the metal mold is tested.

[0051] Comparative Example 1

[0052] A high-gloss black material, the preparation method thereof comprising the following steps:

[0053] (1) Weigh each component: ASA777K 10 kg, antioxidant 1010 0.01 kg, antioxidant 168 0.01 kg, and lubricant PETS 0.03 kg.

[0054] (2) After the weighed composition is uniformly stirred and mixed in a high-speed mixer, the obtained mixture is fed into the main feeding port of a twin-screw extruder; the temperature of each section of the extruder is controlled to be 100-120-140-150-170-170-170-160-160-150°C, and the screw rotation speed is controlled to be 400 rpm, to granulate to obtain a low-mold-scale high-gloss black ASA product. The obtained high-gloss black ASA product is injection molded at 250°C to obtain a required high-gloss mirror panel (mold polishing 8000 mesh, glossiness 100 GU, and the size of the sample panel is 100*100*3 mm). After 500 molds are continuously injection molded, the glossiness of the high-gloss mirror panel and the metal mold is tested.

[0055] Comparative Example 2

[0056] A high-gloss black material, a preparation method thereof comprises the following steps:

[0057] (1) Weigh each component: ASA777K 8.5 kg, oxalic acid 1.5 kg, antioxidant 1010 0.01 kg, antioxidant 168 0.01 kg, and lubricant PETS 0.03 kg.

[0058] (2) After the weighed composition is uniformly stirred and mixed in a high-speed mixer, the obtained mixture is fed into the main feeding port of a twin-screw extruder; the temperature of each section of the extruder is controlled to be 100-120-140-150-170-170-170-160-160-150°C, and the screw rotation speed is controlled to be 400 rpm, to granulate to obtain a low-mold-scale high-gloss black ASA product. The obtained high-gloss black ASA product is injection molded at 250°C to obtain a required high-gloss mirror panel (mold polishing 8000 mesh, glossiness 100 GU, and the size of the sample panel is 100*100*3 mm). After 500 molds are continuously injection molded, the glossiness of the high-gloss mirror panel and the metal mold is tested.

[0059] Comparative Example 3

[0060] A high-gloss black material, a preparation method thereof comprises the following steps:

[0061] (1) Weigh each component: PMMA / ASA M1600 10 kg, antioxidant 1010 0.01 kg, antioxidant 168 0.01 kg, and lubricant PETS 0.03 kg.

[0062] (2) The weighed composition is uniformly stirred in a high-speed mixer, and the obtained mixture is fed into the main feeding port of a twin-screw extruder; the temperature of each section of the extruder is controlled at 100-120-140-160-180-180-180-170-160-150°C, and the screw speed is controlled at 400 rpm, to granulate the low-fouling high-gloss black PMMA / ASA product. The obtained high-gloss black ASA product is injection molded at 260°C to obtain the required high-gloss mirror panel (mold polishing 8000 mesh, gloss 100 GU, sample panel size 100*100*3 mm). After continuous injection molding of 500 molds, the gloss of the high-gloss mirror panel and the metal mold is tested.

[0063] Comparative Example 4

[0064] A high-gloss black material, the preparation method thereof comprising the following steps:

[0065] (1) Weigh the components: PMMA / ASA M1600 9.8 kg, microcrystalline cellulose 0.2 kg, antioxidant 10100 0.01 kg, antioxidant 168 0.01 kg, and lubricant PETS 0.03 kg.

[0066] (2) The weighed composition is uniformly stirred in a high-speed mixer, and the obtained mixture is fed into the main feeding port of a twin-screw extruder; the temperature of each section of the extruder is controlled at 100-120-140-160-180-180-180-170-160-150°C, and the screw speed is controlled at 400 rpm, to granulate the low-fouling high-gloss black PMMA / ASA product. The obtained high-gloss black ASA product is injection molded at 260°C to obtain the required high-gloss mirror panel (mold polishing 8000 mesh, gloss 100 GU, sample panel size 100*100*3 mm). After continuous injection molding of 500 molds, the gloss of the high-gloss mirror panel and the metal mold is tested.

[0067] The high-gloss resin materials prepared in the above examples and comparative examples were respectively injection molded into standard bars, and the notched impact strength (ISO 179, 23°C) and Vicat softening temperature (ISO 306, B50) tests were carried out according to the relevant standards, and the differences in the relevant data were compared. At the same time, the materials prepared in the relevant examples and comparative examples were continuously injection molded for a long time, and the gloss of the mirror panels after injection molding was evaluated. If the gloss loss of the high-gloss mold after injection molding is reduced by more than 5%, the mold is polished or wiped clean, i.e. when the gloss of the metal mold surface is lower than 95GU, the mold is re-polished or wiped clean. The metal mold surface is monitored by a gloss meter, with a detection frequency of 0.5h / time. The mold dirt is evaluated by the gloss of the high-gloss mirror panel after N continuous injection molding of the material. It takes about 1-1.5 minutes to injection mold 1 mold. After continuously injection molding 500 molds, the higher the gloss of the mold, the less the gloss loss of the high-gloss mirror panel, and the more obvious the low-mold-dirt effect of the prepared material.

[0068] Table 1

[0069]

[0070] The wiping cycle of the high-gloss mirror panel characterizes the cleaning effect of the material on the mold. The longer the wiping cycle, the more obvious the cleaning effect of the material on the mold. The gloss performance of the high-gloss mirror panel after N continuous injection molding characterizes the aggregation of small molecules in the mirror panel. The higher the gloss, the fewer the small molecules, and thus the better the devolatilization effect of the material. The data of the comparative examples and examples prove that the addition of low-mold-dirt additives not only reduces mold dirt and reduces wiping frequency, but also ensures the mirror effect of the high-gloss mirror panel, and has no effect on the notched impact and Vicat temperature of the material. Comparative example 2 shows that when the content of low-mold-dirt additives is higher than 10% (relative to high-gloss black resin + low-mold-dirt additives), although the material can achieve low-mold-dirt effect, it has a great effect on the notched impact and Vicat softening temperature of the material, and is not suitable for high-gloss systems.

[0071] The above description of the examples is for the convenience of those of ordinary skill in the art to understand and use the invention. Those skilled in the art can easily make various modifications to these examples, and apply the general principles described herein to other examples without having to go through creative labor. Therefore, the present application is not limited to the above examples, and those skilled in the art can make improvements and modifications within the scope of the present application without departing from the scope of the present application.

Claims

1. A low mold scale high gloss black spray-free material, characterized in that: The invention comprises the following components and their weight contents: 90-95 weight parts of high gloss black resin; 5-10 weight parts of low mold fouling additive; 0.1-1 weight part of antioxidant; Lubricant: 0.1-1 parts by weight; The decomposition temperature of the low mold fouling additive is 200-300° C., and water vapor and CO, CO2 or N2 are generated during decomposition.

2. The low mold fouling high gloss black spray-free material according to claim 1, characterized in that: The high-gloss black resin is selected from high-gloss ASA resin or high-gloss PMMA / ASA resin.

3. The low mold fouling high gloss black spray-free material according to claim 1, characterized in that: The low mold fouling agent is one or more of oxalic acid, formic acid, or cellulose.

4. The low mold fouling high gloss black spray-free material according to claim 1, characterized in that: The antioxidant is selected from at least one of antioxidant 245, antioxidant 1076 or antioxidant 168.

5. The low mold fouling high gloss black spray-free material according to claim 1, characterized in that: The lubricant is selected from at least one of silicone powder, pentaerythritol stearate or ethylene bis stearamide.

6. A method for preparing the low mold fouling high gloss black spray-free material according to any one of claims 1 to 5, characterized in that: include: The high gloss black resin, oxalic acid, antioxidant and lubricant are mixed, melt-extruded and granulated.

7. The method for preparing the low mold fouling high gloss black spray-free material according to claim 6, characterized in that: During the melt extrusion, the extrusion temperature is 170-180° C. and the rotation speed is 400-500 rpm.

8. A method for processing and forming a low mold fouling high gloss black spray-free material according to any one of claims 1 to 5, characterized in that: The low mold fouling high gloss black spray-free material is used for hot processing and forming.

9. The method for processing and forming the low mold fouling high gloss black spray-free material according to claim 8, characterized in that: The forming temperature of the thermal processing forming is not lower than 200°C.

10. The method for processing and forming the low mold fouling high gloss black spray-free material according to claim 7, characterized in that: The thermal processing molding is injection molding.

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