阅读说明：本技术 一种聚丙烯土工格栅专用复合助剂及包括该复合助剂的聚丙烯土工格栅专用料 (Special composite additive for polypropylene geogrid and special material for polypropylene geogrid comprising same ) 是由 莫志华 赵文林 谭诗豪 蓝美 于 2021-09-22 设计创作，主要内容包括：本发明提供了一种聚丙烯双向拉伸土工格栅复合助剂及聚丙烯双向拉伸土工格栅专用料,所述专用料包括聚丙烯、复合助剂和无机矿物填料,复合助剂包括成核剂和分散剂,其中成核剂是由成核剂A和B以特定质量比复配。本发明通过两种不同成核剂的协同作用,使得到的聚丙烯双向拉伸土工格栅较现有技术中的聚丙烯双向拉伸土工格栅,在同等重量下具有更高的纵向和横向的抗拉强度。本发明还提供由上述聚丙烯双向拉伸土工格栅专用料制得的聚丙烯双向拉伸土工格栅。(The invention provides a polypropylene biaxially oriented geogrid composite additive and a special material for the polypropylene biaxially oriented geogrid, wherein the special material comprises polypropylene, the composite additive and an inorganic mineral filler, the composite additive comprises a nucleating agent and a dispersing agent, and the nucleating agent is compounded by a nucleating agent A and a nucleating agent B according to a specific mass ratio. According to the invention, the obtained polypropylene biaxially oriented geogrid has higher longitudinal and transverse tensile strength under the same weight compared with the polypropylene biaxially oriented geogrid in the prior art through the synergistic effect of two different nucleating agents. The invention also provides a polypropylene biaxial stretching geogrid prepared from the polypropylene biaxial stretching geogrid special material.)

1. The special composite additive for the polypropylene biaxially oriented geogrid is characterized by comprising a nucleating agent and a dispersing agent, wherein the nucleating agent contains a nucleating agent A and a nucleating agent B.

2. The special composite additive for polypropylene biaxially oriented geogrid according to claim 1, wherein the nucleating agent a is one or more selected from the group consisting of sodium benzoate, bis [ 4-tert-butylbenzoic acid ] aluminum hydroxide, bis [2, 2 '-methylene-bis (4, 6-di-tert-butylphenyl) phosphate ] aluminum, bis [2, 2' -methylene-bis (4, 6-di-tert-butylphenyl) phosphate ] sodium, and disodium hexahydrophthalate;

the nucleating agent B is a carboxylic acid metal salt of tetrahydrophthalic anhydride and is selected from one or more of magnesium tetrahydrophthalate, calcium tetrahydrophthalate, strontium tetrahydrophthalate, zinc tetrahydrophthalate, barium tetrahydrophthalate and calcium 4-methyltetrahydrophthalate;

the dispersant is one or more of glyceryl monostearate, polyethylene wax, erucamide and oleamide.

3. A polypropylene biaxially oriented geogrid special material, which is characterized by comprising polypropylene, the composite additive according to claim 1 or 2, and an inorganic mineral filler.

4. The special geogrid material according to claim 3, wherein the polypropylene is a polypropylene homopolymer, the isotacticity of the polypropylene homopolymer is greater than or equal to 96%, and the melt index MFR of the polypropylene is 2-3g/10 min.

5. The special material for geogrids according to any one of claims 3 to 4, wherein the inorganic mineral filler is one or more of talc, calcium carbonate and barium sulfate.

6. The geogrid grade according to any of claims 3 to 5, wherein the concentration of the nucleating agent A in the polypropylene biaxially oriented geogrid grade is 50-2000ppm, preferably 50-1000 ppm; the concentration of the nucleating agent B in the polypropylene biaxial tension geogrid special material is 50-2000ppm, preferably 50-1000 ppm; the content ratio of the nucleating agent A to the nucleating agent B is 1:0.5-3, and preferably 1: 1.

7. The special material for geogrids according to any of claims 3-6, wherein the concentration of the inorganic mineral filler in the special material for polypropylene biaxially oriented geogrids is 1000-; the concentration of the dispersing agent in the polypropylene biaxially oriented geogrid special material is 500-2000ppm, preferably 500-1000 ppm.

8. The preparation method for the polypropylene biaxially oriented geogrid special material according to any one of claims 3 to 7 comprises the steps of uniformly blending polypropylene, the composite auxiliary agent according to claim 1 or 2 and the inorganic mineral filler to obtain a blend, and extruding and granulating the blend through an extruder to obtain the polypropylene biaxially oriented geogrid special material.

9. A polypropylene biaxially oriented geogrid, wherein the geogrid is prepared from the polypropylene biaxially oriented geogrid special material according to any one of claims 3 to 7.

10. Use of the special composite additive for polypropylene biaxially oriented geogrids according to any one of claims 1 to 2 for preparing polypropylene biaxially oriented geogrids.

Technical Field

The invention relates to a special composite additive for polypropylene geogrids, and further relates to a special polypropylene biaxially oriented geogrid material containing the composite additive.

Background

The plastic geogrid is a novel civil engineering synthetic material, the molecular structure of the plastic geogrid has the characteristics of high strength and low elongation after high tensile orientation, and the elastic modulus is close to the level of low-carbon steel, so the plastic geogrid is an ideal synthetic material for civil engineering reinforcement and reinforcement.

The polypropylene in the raw material of the plastic geogrid accounts for 80 percent, and the rib belts of the polypropylene biaxial stretching geogrid are formed by extruding and stretching the polypropylene composition and have high tensile strength. The cross joint points of the longitudinal and transverse rib belts are welded by high-frequency ultrasonic waves, so that the stability of the product quality is ensured, and the effective interlocking of the grid meshes on the soil body is ensured. Meanwhile, the strength of the grating can change the tension of the rib belts, and the rib belts can be adjusted to be designed into different types and specifications, so that the requirements of different projects and various technical indexes can be met.

The polypropylene biaxial tension geogrid has the performances of high strength and low elongation (the elongation at break is not more than 12%), has small creep amount and better flexibility, and can still maintain the performances of the geogrid even if the geogrid is cracked because the material is continuously clamped by strong tension and the two sides of the transverse rib belts.

Pure polypropylene biaxially oriented geogrid can not meet the requirement of mechanical property, and in the prior art, the mechanical property is improved by adding a beta-crystal form nucleating agent into the special master batch for the polypropylene biaxially oriented geogrid, but the balance of the weight and the tensile strength of the geogrid is not researched.

Disclosure of Invention

In view of the defects in the prior art, the invention aims to provide a special composite additive for polypropylene biaxially oriented geogrid and a special material for polypropylene geogrid comprising the same.

The inventor of the present invention found through research that it is difficult for the conventional polypropylene biaxially oriented geogrid special material to obtain a polypropylene biaxially oriented geogrid having both cost and mechanical properties (particularly tensile properties), and conducted intensive research on the composition of the polypropylene biaxially oriented geogrid special material in order to obtain a polypropylene biaxially oriented geogrid having low cost and high tensile strength, found that a polypropylene biaxially oriented geogrid having both high tensile strength and low cost can be obtained by adding a specific composite auxiliary agent to polypropylene resin, specifically compounding a nucleating agent containing a specific kind in the composite auxiliary agent, and thus completed the present invention.

The invention provides a special composite additive for polypropylene biaxially oriented geogrid, which comprises a nucleating agent and a dispersing agent, wherein the nucleating agent contains a nucleating agent A and a nucleating agent B.

The nucleating agent A is selected from one or more of sodium benzoate, bis [ 4-tert-butylbenzoic acid ] aluminum hydroxide, bis [2, 2 '-methylene-bis (4, 6-di-tert-butylphenyl) phosphate ] aluminum, bis [2, 2' -methylene-bis (4, 6-di-tert-butylphenyl) phosphate ] sodium and hexahydrophthalic acid disodium salt;

the nucleating agent B is a carboxylic acid metal salt of tetrahydrophthalic anhydride and is selected from one or more of magnesium tetrahydrophthalate, calcium tetrahydrophthalate, strontium tetrahydrophthalate, zinc tetrahydrophthalate, barium tetrahydrophthalate and calcium 4-methyltetrahydrophthalate;

the dispersant is one or more of glyceryl monostearate, polyethylene wax, erucamide and oleamide.

The second purpose of the invention is to provide a polypropylene biaxial tension geogrid special material, which contains polypropylene, composite auxiliary agent and inorganic mineral filler.

The composite auxiliary agent comprises a nucleating agent and a dispersing agent, wherein the nucleating agent contains a nucleating agent A and a nucleating agent B.

The polypropylene is a polypropylene homopolymer, the isotacticity of the polypropylene homopolymer is greater than or equal to 96%, and the melt index MFR of the polypropylene is 2-3g/10min (the test condition is MFR under a load of 2.16kg at 230 ℃).

The inorganic mineral filler is one or more of talcum powder, calcium carbonate and barium sulfate.

The dispersant is one or more of glyceryl monostearate, polyethylene wax, erucamide and oleamide.

The concentration of the nucleating agent A in the polypropylene biaxial tension geogrid special material is 50-2000ppm, preferably 50-1000 ppm; the concentration of the nucleating agent B in the polypropylene biaxial tension geogrid special material is 50-2000ppm, preferably 50-1000 ppm; the concentration of the inorganic mineral filler in the special material for the polypropylene biaxial tension geogrid is 1000-10000ppm, preferably 1000-5000 ppm; the concentration of the dispersing agent in the polypropylene biaxially oriented geogrid special material is 500-2000ppm, preferably 500-1000 ppm. The balance being polypropylene.

The content ratio of the nucleating agent A to the nucleating agent B is 1:0.5-3, and preferably 1: 1.

The third purpose of the invention is to provide a preparation method of the polypropylene biaxially oriented geogrid special material, which comprises the steps of uniformly blending polypropylene, a composite auxiliary agent and an inorganic mineral filler to obtain a blend, and extruding and granulating the blend by an extruder to obtain the polypropylene biaxially oriented geogrid special material.

The fourth purpose of the invention is to provide a polypropylene biaxial stretching geogrid obtained from the polypropylene biaxial stretching geogrid special material.

The fifth purpose of the invention is to provide an application of the special composite additive for the polypropylene biaxially oriented geogrid in preparation of the polypropylene biaxially oriented geogrid.

Compared with the prior art, the invention has the following advantages:

compared with the polypropylene biaxially oriented geogrid in the prior art, the polypropylene biaxially oriented geogrid obtained by the special material for the polypropylene biaxially oriented geogrid has higher longitudinal and transverse tensile strength under the same weight, and has lighter weight (low cost) under the same longitudinal and transverse tensile strength.

Detailed Description

To better illustrate the objects, aspects and advantages of the present invention, the present invention will be further described with reference to specific examples.

In the example and comparative polypropylene biaxially oriented geogrid formulations, the following raw materials were used:

polypropylene PP: the mark is Yangzhite F401, the isotactic degree is more than or equal to 96 percent of homopolymerized polypropylene, and the MFR is 3g/10 min.

A nucleating agent A: bis [2, 2' -methylene-bis (4, 6-di-tert-butylphenyl) phosphate ] aluminum, commercially available product;

nucleating agent B1: calcium tetrahydrophthalate, produced by itself as science and technology;

a nucleating agent C: n, N-dicyclohexyl-2, 6-naphthalenediamide, a commercially available product;

inorganic minerals: talc, a commercially available product;

dispersing agent: glyceryl monostearate, commercially available product.

The polypropylene biaxially oriented geogrid special material of examples 1 to 3 and comparative examples 1 to 4 is prepared by adopting the component proportions in the table 1, and the steps are as follows:

(S1) uniformly mixing the raw materials in a mixer according to the formula in the table 1-2 to obtain a blend;

(S2) granulating the blend by an extruder according to the operation specification of an SHJ-20 twin-screw extruder, wherein the granulation temperature is 190 ℃ and 220 ℃ to obtain the special polypropylene biaxially oriented geogrid material.

TABLE 1

The polypropylene biaxially oriented geogrid special material obtained in the above way is prepared into polypropylene biaxially oriented geogrid examples 1A to 3A, examples 1B to 3B and comparative examples 1A to 4A, 1B to 4B, and the steps are as follows:

(S11) extruding the special polypropylene bi-directional stretching geogrid material by an extruder at the extrusion temperature of 190-220 ℃, wherein the neck mold is a clothes-hanger-type flat neck mold, and extruding the special polypropylene bi-directional stretching geogrid material from the neck mold and then obtaining a polypropylene plate with uniform thickness by a three-roll calender;

(S12) punching the polypropylene plate by a punch, heating the perforated plate to 80-90 ℃ and stretching to obtain polypropylene biaxially oriented geogrids with the thickness of 2mm, examples 1A-3A and comparative examples 1A-4A, and examples 1B-3B and comparative examples 1B-4B with the thickness of 1.5 mm.

And (3) performance testing:

the polypropylene biaxially oriented geogrid obtained above and having a thickness of 2mm was tested for relevant properties, see table 2 in particular.

Table 2:

the polypropylene biaxially oriented geogrid obtained above and having a thickness of 1.5mm was tested for relevant properties, as shown in table 3.

As can be seen from the comparison of examples 1-3A with comparative examples 1-4A in table 2, the synergistic effect of nucleating agents a and B resulted in a substantial increase in tensile strength of geogrids.

The comparison of examples 1-3A shows that the nucleating agent A and the nucleating agent B have the best effect of improving the tensile strength of the geogrid when the mass ratio is 1: 1.

As can be seen from comparison of examples 1 to 3A with examples 1 to 3B, the geogrid of the present invention can achieve the effect of reducing the quality retention strength.

The preferred embodiments of the present invention have been described in detail, however, the present invention is not limited to the specific details of the above embodiments, and various simple modifications may be made to the technical solution of the present invention within the technical idea of the present invention, and these simple modifications are within the protective scope of the present invention.

It should be noted that the various features described in the above embodiments may be combined in any suitable manner without departing from the scope of the invention. The invention is not described in detail in order to avoid unnecessary repetition.

In addition, any combination of the various embodiments of the present invention is also possible, and the same should be considered as the disclosure of the present invention as long as it does not depart from the spirit of the present invention.