WO2024021846A1 - Low-warpage and glass fiber reinforced polyacrylic material and method for preparing same - Google Patents

Abstract

The present invention belongs to the technical field of plastic materials. Provided are a low-warpage and glass fiber reinforced polyacrylic material and a method for preparing same, and use thereof in preparing an automobile lamp shell material. For the product components, a composite compatilizer of maleic anhydride grafted copolymer polyacrylic and hexamethylenediamine grafted polyacrylic is used to reduce the warpage of the product and deal with the compatibility problem between the glass fiber and polyacrylic resin, so that the product has good mechanical property and low warpage without introducing a mineral filler or a flat glass fiber and has no such defects as floating fiber in appearance.

Description

A kind of low warpage glass fiber reinforced polypropylene material and its preparation method Technical field

The invention relates to the technical field of plastic materials, and in particular to a low-warpage glass fiber reinforced polypropylene material and a preparation method thereof.

Background technique

Polypropylene (PP) material is widely used in daily necessities, home appliances, automobiles and other fields due to its excellent comprehensive properties such as light density, low water absorption, and rich sources of raw materials. However, pure polypropylene has relatively low rigidity and insufficient heat resistance. Poor impact resistance and large molding shrinkage. Therefore, the existing technology often uses glass fiber reinforced modified polypropylene materials to greatly improve its rigidity. However, since glass fiber is a needle-like structural filler and has a very high aspect ratio compared to granular fillers, it is difficult to inject the finished product. Different orientation degrees will appear during the process. The polypropylene molecular chain is oriented and crystallized along the flow direction, and the glass fiber is oriented along the flow direction, resulting in a large difference in shrinkage between the material flow direction and the vertical flow direction. Unbalanced shrinkage will cause the material to warp. In addition, the compatibility between glass fiber and polypropylene resin matrix is poor. In particular, some products with more complex structures will have problems such as poor appearance and floating fibers on the surface when using glass fiber reinforced polypropylene materials.

In order to improve the warpage and material compatibility problems of glass fiber reinforced polypropylene materials, the more mainstream methods in the existing technology are: (1) adding some mineral powder as reinforcing materials to replace the glass fiber, and overall reducing the polypropylene composite The molding shrinkage of the material is reduced to reduce warpage, but this approach will significantly reduce the comprehensive mechanical properties of the polypropylene material. (2) Select specific flat glass fibers as reinforcing materials. Flat glass fibers are better at resisting warping, but they will also reduce the mechanical properties of polypropylene materials, and flat glass fibers are more expensive than ordinary glass fibers. , severely limiting its scope of use.

Contents of the invention

Based on the shortcomings of the existing technology, the purpose of the present invention is to provide a low-warp glass fiber reinforced Polypropylene material, a specific composite compatibilizer is used in the product components to reduce the warpage problem of the product and the compatibility problem between glass fiber and polypropylene resin, so that the product can be made without the introduction of mineral fillers or flat glass fibers. It has good mechanical properties and low warpage, and has no defects such as floating fibers in appearance.

In order to achieve the above objects, the technical solutions adopted by the present invention are:

A low-warp glass fiber reinforced polypropylene material includes the following components by weight:

60 to 65 parts of polypropylene resin, 28 to 32 parts of glass fiber, 2 to 8 parts of composite compatibilizer, and 0.2 to 1 part of processing aids;

The composite compatibilizer is a mixture of maleic anhydride graft copolymerized polypropylene and hexamethylenediamine grafted polypropylene.

Among the components of the low-warp glass fiber reinforced polypropylene material of the present invention, the composite compatibilizer plays a key role. It not only effectively improves the compatibility of the glass fiber and the polypropylene resin, but also effectively reduces the The orientation difference of the fibers prevents the product from warping and deforming; on the other hand, the introduction of the composite compatibilizer can also effectively improve the mechanical properties of glass fiber reinforced polypropylene materials.

Among the composite compatibilizers, maleic anhydride graft copolymerized polypropylene itself is a better compatibilizer with polypropylene resin, which can effectively improve the compatibility of the composite compatibilizer itself, but it forms during product processing It is a rigid short molecular chain, and during the cooling process of the product, these rigid short molecular chains will be rapidly cooled and stabilized, so that the polypropylene resin and glass fiber in the components have no time to twist and naturally stretch and discharge, and the internal internal stress will be large. Existing alone will cause the product to be damaged. Various properties are attenuated, and when compounded with hexamethylenediamine-grafted polypropylene, there are 6 carbons in the ethylenediamine main chain in the hexamethylenediamine-grafted polypropylene, and both ends can be grafted with polypropylene resin and glass fiber. The formation of flexible long chains facilitates flipping and movement, thereby alleviating internal stress. At the same time, the two will also undergo a certain degree of grafting and molecular chain entanglement. They need to cooperate with each other and are indispensable to effectively enhance component compatibility and improve Product warpage phenomenon, while improving product mechanical properties. The inventor found through experiments that using any one alone or replacing it with other types of compatibilizers will lead to a significant decline in product performance.

Preferably, the weight parts of the composite compatibilizer are 4 to 6 parts.

Through experiments, the inventor found that gradually increasing the content of the composite compatibilizer can improve the overall performance of the product to a certain extent. In particular, the warpage phenomenon can be further improved. If the content is further increased, the mechanical properties or warpage of the product will be improved. The degree begins to level off and becomes insignificant or even decreases slightly. Considering the cost factor, the added weight portion of the above-mentioned composite compatibilizer is the most cost-effective.

Preferably, the mass ratio of maleic anhydride-grafted polypropylene and hexamethylenediamine-grafted polypropylene in the composite compatibilizer is (2:3) to (3:2).

As mentioned above, in the composite compatibilizer, the two components play their respective roles. As the content of hexamethylenediamine-grafted polypropylene increases, the mechanical properties and warpage improvement of the product are improved, but As its content continues to increase and its specific gravity increases, the flexibility of the resin molecules of the product will increase, the rigidity will decrease, and the warpage of the product will increase due to compatibility issues. According to the inventor's experimental screening, with the above ratio The composite compatibilizer is the most beneficial among the low-warp glass fiber reinforced polypropylene materials of the present invention.

Preferably, the hexamethylenediamine-grafted polypropylene is hexamethylenediamine-grafted homopolypropylene.

Preferably, the grafting rate of the hexamethylenediamine-grafted polypropylene is 0.8% to 1.0%.

The grafting rate can be measured directly using infrared spectroscopy.

In the actual production process, when the added amount of polypropylene resin is constant and hexanediamine is introduced as the grafting raw material, as its content increases, the final grafting rate of hexamethylenediamine grafted polypropylene does not increase. Obviously, the inventor experimentally found that when the grafting rate of hexamethylenediamine-grafted polypropylene is low, the number of effective flexible long chains formed in the product of the present invention is smaller, and the product does not meet the expected optimization requirements. performance, improve the flexible turning effect.

Preferably, the polypropylene resin is at least one of copolymerized polypropylene and homopolymerized polypropylene.

More preferably, the polypropylene resin is a mixture of copolymerized polypropylene and homopolymerized polypropylene.

More preferably, the mass ratio of the copolymerized polypropylene and homopolymerized polypropylene is (18-22): (40-50).

Homopolymer polypropylene has higher crystallinity and higher strength, but its impact resistance is relatively poor, while copolymer polypropylene has relatively better comprehensive mechanical properties. After experiments by the inventor, it was found that the two polypropylene resins have When used together, it can not only effectively protect the mechanical properties of the product, but also have higher compatibility with composite compatibilizers and glass fibers.

Preferably, the single fiber diameter of the glass fiber is 13-14 μm.

Preferably, the processing aid includes at least one of a lubricant and an antioxidant.

More preferably, the lubricant is erucamide, and the antioxidant is at least one of a hindered phenol antioxidant and a phosphite antioxidant.

More preferably, the antioxidant is a mixture of hindered phenol antioxidant and phosphite antioxidant. The mass ratio is (0.8～1.2): (0.8～1.2).

Another object of the present invention is to provide a method for preparing the low-warpage glass fiber reinforced polypropylene material, which includes the following steps:

Mix each component except glass fiber evenly under the protection of an inert atmosphere, then put it into a twin-screw extruder to melt and disperse, add glass fiber, mix, plasticize and granulate, to obtain the low-warp glass fiber reinforced polypropylene Material.

The preparation method of the low-warpage glass fiber reinforced polypropylene material of the present invention has simple operation steps and can realize industrial large-scale production.

Preferably, the aspect ratio of the twin-screw extruder is (30-50):1.

Preferably, the temperature of the twin-screw extruder is set to 100~200°C, the screw speed is 350~450rpm, and the vacuum degree is -0.04~-0.08MPa.

Another object of the present invention is to provide the application of the low-warpage glass fiber reinforced polypropylene material in preparing automobile lamp housing materials.

Since the low-warp glass fiber reinforced polypropylene material of the present invention effectively alleviates the warping phenomenon and appearance problems of existing glass fiber reinforced polypropylene products, and has good mechanical properties, it is very suitable for applications that have problems with appearance and dimensional stability. Among the higher requirements of automotive lamp housing materials.

The beneficial effect of the present invention is that the present invention provides a low-warpage glass fiber reinforced polypropylene material. The product component uses a composite compatibilizer of maleic anhydride graft copolymer polypropylene and hexamethylene diamine graft polypropylene. In order to reduce the warpage problem of the product and the compatibility problem between glass fiber and polypropylene resin, the product has good mechanical properties and low warpage without introducing mineral fillers or flat glass fibers, and at the same time, the appearance is smooth. Fiber and other defects. The invention also provides a preparation method of the product and its application in preparing automobile lamp housing materials.

Description of drawings

Figure 1 is a schematic diagram of a sample without floating fibers during the appearance floating fiber test described in Effect Example 1 of the present invention.

Figure 2 is a schematic diagram of a sample with floating fibers during the appearance floating fiber test described in Effect Example 1 of the present invention.

Detailed ways

In order to better illustrate the purpose, technical solutions and advantages of the present invention, the present invention will be further described below in conjunction with specific examples and comparative examples. The purpose is to understand the content of the present invention in detail, but not to limit the present invention. All other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the protection scope of the present invention. The experimental reagents and instruments involved in the implementation of the present invention are all commonly used ordinary reagents and instruments unless otherwise specified.

Examples 1 to 9

Examples of the low-warpage glass fiber reinforced polypropylene material and its preparation method according to the present invention. The components of the low warpage glass fiber reinforced polypropylene material are as shown in Table 1.

The preparation method of the low warpage glass fiber reinforced polypropylene material includes the following steps:

Mix each component except glass fiber in a high mixer under the protection of nitrogen atmosphere for 3 to 5 minutes until uniform, then put it into a twin-screw extruder to melt and disperse, add glass fiber, mix, plasticize and granulate to obtain the result The low warpage glass fiber reinforced polypropylene material.

The main engine speed of the twin-screw extruder is 350 rpm, the screw length-to-diameter ratio is 40:1, and the vacuum degree is -0.04~-0.08MPa.

Comparative Examples 1 to 10

The only difference between the comparative examples and the examples is the component types and proportions, as shown in Table 2.

Among the components described in each example and comparative example,

Polypropylene resin 1 is homopolymer polypropylene resin, model M1200HS produced by Shanghai Petrochemical;

Polypropylene resin 2 is copolymerized polypropylene resin, model 7033N produced by ExxonMobil;

The glass fiber is ECS13-03-508A produced by Jushi Glass Fiber, with a single filament diameter of 13 to 14 μm;

Compatibilizer 1a is maleic anhydride graft copolymer polypropylene, BONDYRAM 1001 produced by Prilan;

Compatibilizer 1b is maleic anhydride graft copolymer polypropylene, CA100 produced by Arkema, France;

Compatibilizer 2 is self-made hexamethylenediamine grafted polypropylene. The specific preparation method is:

Mix homopolypropylene (same as polypropylene resin 1), silane coupling agent, hexamethylenediamine and processing aids (commercially available hindered phenol antioxidant and commercially available phosphite antioxidant at a mass ratio of 1:1 The mixture) is mixed according to the mass ratio of 100:3:10:0.5 and then placed in a twin-screw extruder to melt, mix, disperse, and granulate to obtain hexamethylenediamine grafted Polypropylene; the average grafting rate of hexamethylenediamine in this product is 0.8-1.0%;

Compatibilizer 3

Mix homopolypropylene (same as polypropylene resin 1), silane coupling agent, and processing aid (a mixture of commercially available hindered phenol antioxidant and commercial phosphite antioxidant at a mass ratio of 1:1) according to the After mixing with a mass ratio of 100:3:0.5, it is placed in a twin-screw extruder for melting, mixing, dispersion, and granulation to obtain compatibilizer 3;

Compatibilizer 4 is maleic anhydride grafted homopolypropylene, BONDYRAM 1001CN produced by Prilan;

Compatibilizer 5 is maleic anhydride grafted ethylene copolymer, N493 produced by DuPont;

Antioxidants include commercially available hindered phenol antioxidants and commercially available phosphite antioxidants;

Erucamide is commercially available erucamide;

The mass ratio of hindered phenol antioxidant and phosphite antioxidant is: m (hindered phenol antioxidant: phosphite antioxidant) = 1:1.

Unless otherwise specified, the raw materials used in the various examples and comparative examples of the present invention are all commercially available raw materials, and the raw materials used in each parallel experiment are all of the same kind.

Table 1

Table 2

Effect example 1

The products obtained in each example and comparative example were subjected to tensile strength, Izod notched impact strength, warpage test and appearance floating fiber test:

(1) Tensile strength test: ISO 527-2-2012 is used to test the flexural modulus of the material, and the tensile rate is 10mm/min;

(2) Izod notched impact strength test: Izod notched impact strength using ISO180-2000 test materials, A-type notch, 4mm, 23℃, impact pendulum capacity is 5.5J;

(3) Warpage test: Inject each product into a square plate of 100*100*1.5mm, place it aside to cool naturally, observe the warpage of the sample, and test the maximum warpage height (place the square plate on a marble slab on the square plate, fix one corner close to the marble surface, and measure the distance between the diagonal position of the square plate and the marble surface);

(4) Appearance floating fiber test: Visual inspection, the appearance of no floating fibers is shown in Figure 1, and the appearance of floating fibers is shown in Figure 2.

The test results are shown in Tables 3 and 4.

table 3

Table 4

It can be seen from Table 3 and Table 4 that the warpage height of the low-warp glass fiber reinforced polypropylene materials prepared in various embodiments of the present invention can be controlled within 10 mm, and there is no obvious floating fiber phenomenon in appearance. Compared with Compared with the glass fiber reinforced polypropylene material of Comparative Example 10 without adding compatibilizer component, its mechanical properties have been improved and its comprehensive performance is excellent. From the comparison of Comparative Example 3, it can be seen that whether the polypropylene in the composite compatibilizer is grafted with hexamethylenediamine has a direct impact on the performance of the product, which may cause the mechanical properties of the product to decrease and the ideal warpage cannot be achieved; from Example 3 to 7 It can be seen that the ratio of the two components in the composite compatibilizer is different, and the performance of the product is also affected. As the content of hexamethylenediamine-grafted polypropylene increases to a certain extent, the mechanical properties of the product and the warpage are improved. The degree has been improved, but if the content is too much, these properties will be reduced due to compatibility issues. Therefore, the performance is best when the mass ratio of the two is (2:3) ~ (3:2) good. It can be seen from Examples 8 and 9 that the more the compound compatibilizer is added, the better. Under the condition of 0.4 to 0.6 parts, the product can achieve ideal performance with less raw material cost. In contrast, Although the products in Comparative Examples 1, 2, 4 and 5 also use composite compatibilizers for system adjustment, the types used are not within the scope of the present invention. Compared with the product of Comparative Example 9, the warpage phenomenon of the products is not obvious. Improvement; while there is only one compatibilizer in the products of Comparative Examples 6 to 9, whether the compatibilizer is maleic anhydride graft copolymer polypropylene or hexamethylene diamine graft copolymer mentioned in the present invention, or existing Although the mechanical properties of other types of compatibilizers commonly used in the field have been improved to a certain extent compared with the product of Comparative Example 9, the degree of warpage has not been reduced, and the appearance cannot be guaranteed. It can be seen from Comparative Examples 11 and 12 that the amount of compatibilizer added to the glass fiber reinforced polypropylene material product of the present invention is too small, which makes it difficult to improve the compatibility of polypropylene resin and glass fiber, and it is difficult to improve various properties. To achieve the ideal level, adding too much compatibilizer will not only increase the cost of raw materials, but also the overall performance will not achieve the effect of each embodiment.

Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and do not limit the protection scope of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that The technical solution of the present invention may be modified or equivalently substituted without departing from the essence and scope of the technical solution of the present invention.

Claims (9)

1. A low-warp glass fiber reinforced polypropylene material, which is characterized in that it includes the following components by weight:

   60 to 65 parts of polypropylene resin, 28 to 32 parts of glass fiber, 2 to 8 parts of composite compatibilizer, and 0.2 to 1 part of processing aids;

   The composite compatibilizer is a mixture of maleic anhydride graft copolymerized polypropylene and hexamethylenediamine grafted polypropylene.
2. The low-warp glass fiber reinforced polypropylene material according to claim 1, wherein the weight portion of the composite compatibilizer is 4 to 6 parts.
3. The low warpage glass fiber reinforced polypropylene material according to claim 1, characterized in that the mass ratio of maleic anhydride graft copolymer polypropylene and hexamethylenediamine graft polypropylene in the composite compatibilizer is (2:3 )~(3:2).
4. The low-warp glass fiber reinforced polypropylene material according to claim 1, wherein the grafting rate of the hexamethylenediamine-grafted polypropylene is 0.8 to 1%.
5. The low-warp glass fiber reinforced polypropylene material according to claim 1, wherein the polypropylene resin is at least one of copolymerized polypropylene and homopolymerized polypropylene.
6. The low-warp glass fiber reinforced polypropylene material according to claim 1, wherein the processing aid includes at least one of a lubricant and an antioxidant;

   Preferably, the lubricant is erucamide, and the antioxidant is at least one of a hindered phenol antioxidant and a phosphite antioxidant.
7. The preparation method of low-warp glass fiber reinforced polypropylene material according to any one of claims 1 to 6, characterized in that it includes the following steps:

   Mix each component except glass fiber evenly under the protection of an inert atmosphere, then put it into a twin-screw extruder to melt and disperse, add glass fiber, mix, plasticize and granulate, to obtain the low-warp glass fiber reinforced polypropylene Material.
8. The preparation method of low warpage glass fiber reinforced polypropylene material according to claim 7, characterized in that the aspect ratio of the twin-screw extruder is (30-50): 1; The temperature is set to 100~200℃, the screw speed is 350~450rpm, and the vacuum degree is -0.04~-0.08MPa.
9. The low warpage glass fiber reinforced polypropylene material according to any one of claims 1 to 6 is used in the preparation of automobile lamps. Applications in shell materials.