阅读说明：本技术 一种pvc复合热稳定剂及其应用、聚氯乙烯制品 (PVC composite heat stabilizer, application thereof and polyvinyl chloride product ) 是由 廖正福 叶炜华 于 2021-09-07 设计创作，主要内容包括：本申请属于PVC技术领域,尤其涉及一种PVC复合热稳定剂及其应用、聚氯乙烯制品。本申请第一方面公开了式Ⅰ所示化合物在提高聚氯乙烯的热稳定性中的应用；本申请第二方面提供了一种PVC复合热稳定剂,包括：式Ⅰ所示化合物；本申请的PVC复合热稳定剂,还包括硬脂酸锌和硬脂酸钙。本申请第三方面公开了聚氯乙烯制品的制备方法,将PVC和所述PVC复合热稳定剂机械混合,开炼,制得聚氯乙烯制品。本申请的式Ⅰ所示化合物为氰基酰脲化合物,作为PVC热稳定剂具有良好的热稳定效果,与硬脂酸锌和硬脂酸钙复合使用具有更佳的稳定效果。式Ⅰ所示化合物可以吸收HCl以及与Zn2+形成配合物,改善PVC的热稳定性能和加工性能。(The application belongs to the technical field of PVC, and particularly relates to a PVC composite heat stabilizer, application thereof and a polyvinyl chloride product. The application discloses the application of a compound shown as a formula I in improving the thermal stability of polyvinyl chloride; in a second aspect, the present application provides a PVC composite heat stabilizer, comprising: a compound of formula I; the PVC composite heat stabilizer further comprises zinc stearate and calcium stearate. In the third aspect of the application, PVC and the PVC composite heat stabilizer are mechanically mixed and milled to prepare the PVC product. The compound shown in the formula I is a cyanoureide compound, has a good thermal stability effect when used as a PVC heat stabilizer, and has a better stability effect when used in combination with zinc stearate and calcium stearate. The compound shown in the formula I can absorb HCl and form a complex with Zn2+, and the thermal stability and the processability of PVC are improved.)

1. The application of the compound shown in the formula I in improving the thermal stability of polyvinyl chloride;

wherein n is 1-8.

2. The use according to claim 1, wherein the mass ratio of PVC to the compound of formula I is 100 (1-2).

3. A PVC composite heat stabilizer is characterized by comprising: a compound of formula I.

4. The PVC composite heat stabilizer according to claim 3, further comprising zinc stearate and calcium stearate.

5. The PVC composite heat stabilizer according to claim 4, which comprises the following components in parts by mass:

1-2 parts of a compound shown as a formula I;

0-3 parts of zinc stearate;

0-3 parts of calcium stearate.

6. The PVC composite heat stabilizer according to claim 3, further comprising a plasticizer.

7. The PVC composite heat stabilizer according to claim 6, wherein the plasticizer is selected from one or more of dioctyl phthalate, di-n-butyl phthalate, diisobutyl phthalate, diisodecyl phthalate and dioctyl terephthalate.

8. The PVC composite heat stabilizer according to claim 6, wherein the plasticizer is 5 to 15 parts by mass.

9. A method for preparing a polyvinyl chloride product, which is characterized in that PVC and the PVC composite heat stabilizer of any one of claims 3 to 8 are mechanically mixed and milled to prepare the polyvinyl chloride product.

10. A polyvinyl chloride article comprising the polyvinyl chloride article produced by the production method according to claim 9.

Technical Field

The application belongs to the technical field of PVC, and particularly relates to a PVC composite heat stabilizer, application thereof and a polyvinyl chloride product.

Background

Polyvinyl chloride (PVC) is one of general plastics and has excellent performance. The industrial production of polyvinyl chloride contains thermally unstable groups such as tertiary chloride and allyl chloride, which causes degradation and the like during heating, and can not meet the processing requirements. Therefore, it is necessary to use a heat stabilizer to improve the heat stability of polyvinyl chloride during processing.

At present, the polyvinyl chloride heat stabilizer mainly comprises lead salts, metal soaps, organic tin, composite stabilizers and other auxiliary stabilizers. The lead salt stabilizer is low in price and stable in performance, but contains heavy metals such as lead and the like, has high toxicity and is easy to pollute the environment, and the organic tin is low in environmental hazard and expensive, while other heat stabilizers have some problems more or less.

Disclosure of Invention

Based on this, the application provides a PVC composite heat stabilizer and application thereof, and a polyvinyl chloride product, and effectively solves the defects that the existing PVC heat stabilizer generally contains heavy metals, has high toxicity and is easy to cause environmental pollution.

The application discloses the application of a compound shown as a formula I in improving the thermal stability of polyvinyl chloride;

wherein n is 1-8.

In another embodiment, the mass ratio of the PVC to the compound shown in the formula I is 100: 1-100: 2.

In another embodiment, the compound of formula I of the present application is a cyanoureide, which is prepared by a process comprising the steps of: mixing urea, cyano carboxylic acid and acid anhydride, heating for reaction, and then purifying and washing to obtain the compound shown in the formula I.

Specifically, urea and cyanoacetic acid are added into a three-neck flask according to the quantity ratio of the substances, acetic anhydride with the quantity equal to that of the substances is added, and the system is placed in an oil bath at the temperature of 80 ℃ for reaction. The system gradually became a transparent liquid and then a substance was precipitated. Putting the reactant in a reduced pressure distillation device, wherein the vacuum degree is not lower than 0.08MPa, the reduced pressure distillation temperature is 80 ℃, and distilling off the acetic acid generated in the reaction process. Washing with water, filtering, grinding and washing the solid for multiple times until the pH value of the filtrate is 7, and then putting the filtrate into a vacuum oven to be dried at the temperature of 80 ℃ to obtain the product of cyanoacetylurea.

In a second aspect, the present application provides a PVC composite heat stabilizer, comprising: a compound of formula I.

In another embodiment, the PVC composite heat stabilizer further comprises zinc stearate and calcium stearate.

In another embodiment, the method comprises the following steps of:

1-2 parts of a compound shown as a formula I;

0-3 parts of zinc stearate;

0-3 parts of calcium stearate.

Specifically, the PVC composite heat stabilizer comprises, by mass, 10 parts of dioctyl phthalate and 2 parts of cyanoacetylurea; or the PVC composite heat stabilizer comprises 10 parts of dioctyl phthalate, 1.8 parts of zinc stearate and 1.2 parts of cyanoacetylurea; or the PVC composite heat stabilizer comprises 10 parts of dioctyl phthalate, 1.8 parts of calcium stearate and 1.2 parts of cyanoacetylurea; or the PVC composite heat stabilizer comprises 10 parts of dioctyl phthalate, 0.72 part of calcium stearate, 1.08 parts of zinc stearate and 1.2 parts of cyanoacetylurea.

In another embodiment, the PVC composite heat stabilizer further comprises a plasticizer.

In another embodiment, the plasticizer is selected from one or more of dioctyl phthalate, di-n-butyl phthalate, diisobutyl phthalate, diisodecyl phthalate and dioctyl terephthalate.

In another embodiment, the plasticizer is 5 to 15 parts by mass.

In another embodiment, the plasticizer is 10 parts by mass.

In the third aspect of the application, PVC and the PVC composite heat stabilizer are mechanically mixed and milled to prepare the PVC product.

Specifically, the preparation method comprises the step of carrying out open milling on a double-roller open mill, wherein the roller temperature of the double-roller open mill is 130-160 ℃, the roller spacing is 0.4-0.6 mm, the roller speed is 40-50 r/min, and the open milling time is 2-4 min.

Specifically, the roll temperature of the double-roll open mill is 140 ℃, the roll gap is 0.5mm, the roll speed is 45r/min, and the open mill time is 3 min.

The fourth aspect of the application discloses a polyvinyl chloride product, which comprises the polyvinyl chloride product prepared by the preparation method.

The application discloses cyano ureide shown in formula I as a PVC heat stabilizer, which has a good heat stabilization effect as the PVC heat stabilizer and has a better stabilization effect when being used in a compounding way with zinc stearate and calcium stearate. Cyanoureides of the formula I can absorb HCl and also Zn²⁺Forming a complex, and improving the thermal stability and the processability of PVC; the cyanoureide shown in the formula I can generate a synergistic effect when used together with a traditional heat stabilizer, and the heat stability of PVC is remarkably improved.

In addition, the application also provides a PVC composite heat stabilizer, wherein the cyanoureide shown in the formula I is used as a main stabilizer and compounded with other synergistic components, so that the stability of the PVC heat stabilizer is effectively improved, and the 'zinc burning phenomenon' of PVC is relieved; the cyanoureide shown in the formula I has the capability of absorbing hydrogen chloride, and can eliminate or reduce the discoloration phenomenon of PVC by cooperating with calcium stearate and zinc stearate; the PVC composite heat stabilizer system does not contain heavy metal substances, and meets the requirements of no toxicity and environmental protection; and the PVC product prepared by the PVC composite heat stabilizer has simple process.

Drawings

In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below.

FIG. 1 is a nuclear magnetic resonance hydrogen spectrum of cyanoacetylurea provided in the examples of the present application;

FIG. 2 is a graph showing the results of a heat aging test using an oven discoloration method for samples 1 to 4 and comparative samples 1 to 3 and 6, provided in example 6 of the present application; wherein, blank spaces of the samples 1-3 and the comparison samples 1-3 in figure 2 are no-result graphs, white-yellow-orange-red-black in the graph represents the degradation degree of PVC under heat, and the darker the color is, the greater the degradation degree of PVC is.

Detailed Description

The application provides a PVC composite heat stabilizer, application thereof and a polyvinyl chloride product, which are used for solving the technical defects that PVC heat stabilizers in the prior art generally contain heavy metals, are high in toxicity and easily cause environmental pollution.

The technical solutions in the embodiments of the present application will be described clearly and completely below, and it should be understood that the described embodiments are only a part of the embodiments of the present application, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

The raw materials and reagents used in the following examples are commercially available or self-made.

Example 1

This example carried out a process for the preparation of cyanoacetylurea comprising:

adding urea and cyanoacetic acid into a three-neck flask according to the quantity ratio of the substances, adding acetic anhydride with the quantity equal to the substances, and placing the system in an oil bath at the temperature of 80 ℃ for stirring reaction at constant temperature. The system gradually became a transparent liquid and then a substance was precipitated. The reaction device is modified into a reduced pressure distillation device, the vacuum degree is not lower than 0.08MPa, the reduced pressure distillation temperature is 80 ℃, and the acetic acid generated in the reaction process is evaporated. Washing with water, filtering, grinding and washing the solid for multiple times until the pH value of the filtrate is 7, and then putting the filtrate into a vacuum oven to be dried at the temperature of 80 ℃ to obtain the product of cyanoacetylurea.

The NMR spectrum of the product of this example was analyzed, and the results are shown in FIG. 1 (the unlabeled peak in FIG. 1 is the absorption peak of the solvent), indicating that cyanoacetylurea was successfully obtained.

Example 2

The formulation for sample 1 of this example is as follows: 100 parts of PVC, 10 parts of dioctyl phthalate, 2 parts of cyanoacetylurea from example 1. The raw materials are weighed according to the formula and mixed uniformly by a stirrer to obtain a sample 1. The static thermal stability of the test sample is tested by adopting a thermal aging method, the dynamic thermal stability and the processability of the test sample are tested by adopting a torque rheometer, and the material temperature is 180-185 ℃ in the test process. The test data are shown in table 1 and fig. 2.

Example 3

The formulation for sample 2 of this example is as follows: 100 parts of PVC, 10 parts of dioctyl phthalate, 1.8 parts of calcium stearate, 1.2 parts of cyanoacetylurea from example 1. The raw materials are weighed according to the formula and mixed uniformly by a stirrer to obtain a sample 2. The static thermal stability of the test sample is tested by adopting a thermal aging method, the dynamic thermal stability and the processability of the test sample are tested by adopting a torque rheometer, and the material temperature is 180-185 ℃ in the test process. The test data are shown in table 1 and fig. 2.

Example 4

Sample 3 of this example was formulated as follows: 100 parts of PVC, 10 parts of dioctyl phthalate, 1.8 parts of zinc stearate, 1.2 parts of cyanoacetylurea from example 1. The raw materials are weighed according to the formula and mixed uniformly by a stirrer to obtain a sample 3. The static thermal stability of the test sample is tested by adopting a thermal aging method, the dynamic thermal stability and the processability of the test sample are tested by adopting a torque rheometer, and the material temperature is 180-185 ℃ in the test process. The test data are shown in table 1 and fig. 2.

Example 5

Sample 4 of this example was formulated as follows: 100 parts of PVC, 10 parts of dioctyl phthalate, 0.72 part of calcium stearate, 1.08 parts of zinc stearate, 1.2 parts of cyanoacetylurea from example 1. The raw materials are weighed according to the formula and mixed uniformly by a stirrer to obtain a sample 4. The static thermal stability of the test sample is tested by adopting a thermal aging method, the dynamic thermal stability and the processability of the test sample are tested by adopting a torque rheometer, and the material temperature is 180-185 ℃ in the test process. The test data are shown in table 1 and fig. 2.

Comparative example 1

The formulation of comparative example 1 is as follows: 100 parts of PVC, 10 parts of dioctyl phthalate and 3 parts of zinc stearate. The raw materials are weighed according to the formula and mixed uniformly by a stirrer to obtain a reference sample 1. The Congo red method is adopted to test the static thermal stability of the sample, the torque rheometer is adopted to test the dynamic thermal stability and the processability of the sample, and the material temperature is 180-185 ℃ in the test process. The test data are shown in table 1 and fig. 2.

Comparative example 2

The formulation of comparative example 2 is as follows: 100 parts of PVC, 10 parts of dioctyl phthalate and 3 parts of calcium stearate. The raw materials are weighed according to the formula and mixed evenly by a stirrer to obtain a reference sample 2. The Congo red method is adopted to test the static thermal stability of the sample, the torque rheometer is adopted to test the dynamic thermal stability and the processability of the sample, and the material temperature is 180-185 ℃ in the test process. The test data are shown in table 1 and fig. 2.

Comparative example 3

Comparative example 3 this comparative example had the following formulation: 100 parts of PVC, 10 parts of dioctyl phthalate, 1.8 parts of calcium stearate and 1.2 parts of zinc stearate. The raw materials are weighed according to the formula and mixed uniformly by a stirrer to obtain a reference sample 3. The Congo red method is adopted to test the static thermal stability of the sample, the torque rheometer is adopted to test the dynamic thermal stability and the processability of the sample, and the material temperature is 180-185 ℃ in the test process. The test data are shown in table 1 and fig. 2.

Example 6

The static thermal stability of samples 1-4 and comparative samples 1-3 was tested using Congo Red. Referring to table 1, table 1 shows static thermal stability times of samples 1-4 and comparative samples 1-3 measured by congo red. In Table 1, the static thermal stability time of sample 1 is significantly longer than that of comparative samples 1-3, and the static thermal stability time of samples 2-4 is significantly longer than that of comparative samples 1-3, indicating that the inventive cyanoacetylurea alone can improve the thermal stability of PVC, and when used together with zinc stearate and calcium stearate, can improve the thermal stability of calcium stearate and zinc stearate to PVC.

And carrying out heat aging test on the samples 1-4 and the comparative samples 1-3 by adopting an oven color changing method, which specifically comprises the following steps: the test sample is cut into small sample strips of 20mm multiplied by 20mm, the sample strips are placed into a blowing oven at 180 ℃ for heating, the color change is recorded every 10 minutes, and the result refers to fig. 2, and the colors of the sample 1 to the sample 4 illustrate that the PVC composite heat stabilizer can improve the thermal stability of PVC. Cyanoyl urea is added into the sample 1, calcium stearate is added into the comparative sample 2, the two main functions are to absorb hydrogen chloride gas generated by PVC degradation, and it is required to be pointed out that the dosage of the Cyanoyl urea of the sample 1 is less than that of the calcium stearate of the comparative sample 2, so that the Cyanoyl urea improves the thermal stability of PVC better than the existing calcium stearate.

Fig. 2 shows that samples 2 to 4 in this example illustrate that cyanoacetylurea, zinc stearate and calcium stearate can generate a synergistic effect when used together, thereby significantly improving the thermal stability of PVC and enabling PVC to have a better stabilizing effect.

TABLE 1

	Sample No. 1	Sample No. 2	Sample No. 3	Sample No. 4	Comparative sample 1	Comparative sample 2	Comparative sample 3
								Time/s	930	1950	1800	1890	296	789	420

The foregoing is only a preferred embodiment of the present application and it should be noted that those skilled in the art can make several improvements and modifications without departing from the principle of the present application, and these improvements and modifications should also be considered as the protection scope of the present application.