CN111607127A

CN111607127A - Rubber vulcanization activator and preparation method and application thereof

Info

Publication number: CN111607127A
Application number: CN202010516298.7A
Authority: CN
Inventors: 刘坤吉; 徐前进
Original assignee: Jiangxi Baohong Nano Technology Co ltd
Current assignee: Jiangxi Baohong Nano Technology Co ltd
Priority date: 2020-06-09
Filing date: 2020-06-09
Publication date: 2020-09-01

Abstract

The invention provides a rubber vulcanization activator, and a preparation method and application thereof, and relates to the technical field of rubber preparation. The preparation method provided by the invention comprises the following steps: mixing soluble zinc salt, calcium terephthalate and water to obtain a mixed dispersion liquid; mixing the mixed dispersion liquid with an alkaline solution, and carrying out a precipitation reaction to obtain mixed slurry; and washing, solid-liquid separation and aging treatment are sequentially carried out on the mixed slurry, so as to obtain the rubber vulcanization activator. According to the invention, zinc oxide is synthesized in situ by using calcium terephthalate, and is uniformly dispersed on the surface of the calcium terephthalate, so that the zinc oxide is not easy to agglomerate and remain in the vulcanization process of rubber, the utilization rate of the zinc oxide is improved, and the pollution to the environment is reduced. In addition, the calcium terephthalate is used as a raw material, so that the binding force of the rubber vulcanization activator and the rubber is effectively improved, and the tensile strength of the rubber is improved.

Description

Rubber vulcanization activator and preparation method and application thereof

Technical Field

The invention relates to the technical field of rubber preparation, in particular to a rubber vulcanization activator, and a preparation method and application thereof.

Background

The zinc oxide has physical properties such as tiny particles, large specific surface area, good dispersibility, looseness, porosity, good fluidity and the like, and is applied to rubber in a large quantity, and the zinc oxide mainly plays a role in reducing heat generation during rubber mixing and improving the strength and elasticity of the rubber.

It has been found that during the vulcanization of rubber, zinc oxide does not participate in the rubber vulcanization reaction completely, and a considerable portion of the zinc oxide agglomerates into solid particles, which remain in the rubber as solid particles and act as an expensive "inorganic filler". The residual zinc oxide not only causes great cost pressure to the rubber industry, but also is released in the abrasion and use process of rubber tires, and causes great harm to the environment, particularly aquatic organisms.

Disclosure of Invention

In view of the above, the present invention aims to provide a method for preparing a rubber vulcanization activator. The rubber vulcanization activator prepared by the invention can improve the dispersibility of zinc oxide in rubber, so that the zinc oxide is not easy to agglomerate and remain in the vulcanization process, and the utilization rate of the zinc oxide is improved.

In order to achieve the above object, the present invention provides the following technical solutions:

the invention provides a preparation method of a rubber vulcanization activator, which comprises the following steps:

mixing soluble zinc salt, calcium terephthalate and water to obtain a mixed dispersion liquid;

mixing the mixed dispersion liquid with an alkaline solution, and carrying out a precipitation reaction to obtain mixed slurry;

and washing, solid-liquid separation and aging treatment are sequentially carried out on the mixed slurry, so as to obtain the rubber vulcanization activator.

Preferably, the mass ratio of the soluble zinc salt to the calcium terephthalate is (1: 5) - (10: 1).

Preferably, the alkaline solution comprises one or more of a NaOH solution, a KOH solution, and ammonia.

Preferably, the molar concentration of the alkaline solution is 0.2-2 mol/L.

Preferably, the mixed dispersion and the alkaline solution are mixed as follows: and dropwise adding the alkaline solution into the mixed dispersion liquid at a dropping rate of 12.5-20 mL/min.

Preferably, the temperature of the aging treatment is 100-200 ℃, and the time is 5-24 h.

The invention also provides a rubber vulcanization activator prepared by the preparation method in the technical scheme, which comprises calcium terephthalate and zinc oxide loaded on the surface of the calcium terephthalate.

Preferably, the mass ratio of the zinc oxide to the calcium terephthalate is 1 (1.3-12).

The invention also provides the application of the rubber vulcanization activator in the technical scheme in vulcanized rubber.

Preferably, the mass ratio of the rubber vulcanization activator to the rubber is (1-5): 100.

The preparation method provided by the invention comprises the following steps: mixing soluble zinc salt, calcium terephthalate and water to obtain a mixed dispersion liquid; mixing the mixed dispersion liquid with an alkaline solution, and carrying out a precipitation reaction to obtain mixed slurry; and washing, solid-liquid separation and aging treatment are sequentially carried out on the mixed slurry, so as to obtain the rubber vulcanization activator. In the invention, after the soluble zinc salt, the calcium terephthalate and the water are mixed, zinc ions can be uniformly adsorbed on the surface of the calcium terephthalate; after adding the alkaline solution, carrying out precipitation reaction on zinc ions on the surface of the calcium phthalate to generate zinc hydroxide precipitate to obtain mixed slurry; after aging treatment, zinc oxide is generated in situ on the surface of the calcium terephthalate. According to the invention, the zinc oxide is synthesized in situ by using the calcium terephthalate, the zinc oxide is uniformly dispersed on the surface of the calcium terephthalate, and the calcium terephthalate is taken as an intermediate carrier and is tightly combined with the rubber when in use, so that the zinc oxide is not easy to agglomerate and remain in the vulcanization process of the rubber, the utilization rate of the zinc oxide is improved, the pollution to the environment is reduced, and the tensile strength of the rubber is improved.

Drawings

FIG. 1 is a standard X-ray diffraction pattern of hexagonal zinc oxide;

FIG. 2 is a scanning electron microscope photograph of the rubber vulcanization activator obtained in example 1;

FIG. 3 is an X-ray diffraction pattern of the rubber vulcanization activator obtained in example 1;

FIG. 4 is a scanning electron microscope photograph of the rubber vulcanization activator obtained in example 2;

FIG. 5 is an X-ray diffraction pattern of the rubber vulcanizing activator obtained in example 2;

FIG. 6 is a scanning electron microscope photograph of the rubber vulcanization activator obtained in example 3.

Detailed Description

In the present invention, the raw materials used are all commercial products which are conventional in the art, unless otherwise specified.

According to the invention, soluble zinc salt, calcium terephthalate and water are mixed to obtain a mixed dispersion liquid.

In the present invention, the mixing order of the soluble zinc salt, calcium terephthalate and water is preferably: firstly mixing calcium terephthalate and part of water to obtain calcium terephthalate dispersion liquid; secondly, mixing soluble zinc salt and the residual water to obtain a soluble zinc salt solution; and thirdly mixing the calcium terephthalate dispersion liquid and the soluble zinc salt solution. In the invention, the first mixing mode is preferably ultrasonic dispersion, and the time of the ultrasonic dispersion is preferably 30-60 min. In the present invention, the second mixing method is not particularly limited, and the soluble zinc salt may be dissolved in water. In the present invention, the third mixing mode is preferably stirring; the stirring temperature is preferably room temperature; the stirring time is preferably 1-3 h; the stirring speed is preferably 2000-4000 rpm, and more preferably 2500-3500 rpm.

In the present invention, the soluble zinc salt preferably includes one or more of zinc sulfate, zinc chloride and zinc nitrate, and further preferably zinc sulfate in the present embodiment. In the present invention, the mass ratio of the soluble zinc salt to the calcium terephthalate is preferably (1: 5) to (10: 1), and more preferably (1: 4) to (8: 1). In the invention, the molar concentration of the soluble zinc salt solution is preferably 0.1-1 mol/L, and more preferably 0.3-0.8 mol/L. In the invention, the solid content of the calcium terephthalate dispersion liquid is preferably 10-50%, and more preferably 20-30%.

After the mixed dispersion liquid is obtained, the mixed dispersion liquid and the alkaline solution are mixed for precipitation reaction to obtain mixed slurry.

In the present invention, the alkaline solution preferably includes one or more of a NaOH solution, a KOH solution, and ammonia water; the molar concentration of the alkaline solution is preferably 0.2-2 mol/L, and more preferably 0.5-1.5 mol/L.

In the invention, the mixing mode is preferably to drop the alkaline solution into the mixed dispersion liquid, and the dropping speed is preferably 12.5-20 mL/min. According to the invention, the stirring is preferably carried out while the dropwise adding is carried out, and the stirring speed is preferably 300-4000 revolutions per minute, and more preferably 350-3500 revolutions per minute. The precipitation reaction is preferably carried out simultaneously with the dropwise addition in the present invention. After the mixing is finished, the temperature of a precipitation reaction system is preferably raised to 60-80 ℃, and the temperature is kept for 0.5-2 h; the heating rate for heating to 60-80 ℃ is preferably 1-5 ℃/min, and more preferably 2-3 ℃/min. In the present invention, the precipitation reaction is more sufficiently carried out by raising the temperature after the addition of the alkaline solution. In the present invention, the stirring is preferably performed while the temperature rise and the heat preservation are performed, and the stirring speed is preferably consistent with the stirring speed, which is not described herein.

After the mixed slurry is obtained, the mixed slurry is sequentially subjected to washing, solid-liquid separation and aging treatment to obtain the rubber vulcanization activator.

In the present invention, the washing is preferably carried out in water and ethanol in this order; the number of times of the water washing and the ethanol washing is preferably 3 to 5 times independently. In the present invention, it is preferable to perform solid-liquid separation after each washing. In the present invention, the solid-liquid separation method is preferably suction filtration. The invention removes unreacted alkaline solution and sulfate ions through multiple times of washing and suction filtration.

In the invention, the temperature of the aging treatment is preferably 100-200 ℃, and more preferably 120-180 ℃; the time of the aging treatment is preferably 1 to 24 hours, and more preferably 2 to 20 hours. In the present invention, the aging treatment is preferably performed in an oven. According to the invention, the temperature of the oven is preferably raised to the aging treatment temperature, and then the product obtained by solid-liquid separation is put into the oven.

In the invention, after the soluble zinc salt, the calcium terephthalate and the water are mixed, zinc ions can be uniformly adsorbed on the surface of the calcium terephthalate; after adding an alkaline solution, carrying out precipitation reaction to generate zinc hydroxide precipitate to obtain mixed slurry; after aging treatment, zinc oxide is generated in situ on the surface of the calcium terephthalate. According to the invention, zinc oxide is synthesized in situ by using calcium terephthalate, the zinc oxide is uniformly dispersed on the surface of the calcium terephthalate, and the calcium terephthalate is taken as an intermediate carrier and is tightly combined with rubber, so that the zinc oxide is not easy to agglomerate and remain in the vulcanization process of the rubber, the utilization rate of the zinc oxide is improved, the pollution to the environment is reduced, and the vulcanization effect of the rubber vulcanization activator on the rubber is improved. Further, the invention synthesizes zinc oxide under the condition of room temperature to 200 ℃, thereby not only saving energy, but also reducing potential safety hazard caused by high temperature production.

The invention also provides a rubber vulcanization activator prepared by the preparation method in the technical scheme, which comprises calcium terephthalate and zinc oxide loaded on the surface of the calcium terephthalate. In the invention, the particle size of the zinc oxide is preferably 15-20 nm. In the invention, the mass ratio of the zinc oxide to the calcium terephthalate is preferably 1 (1.3-12).

In the present invention, the mass ratio of the rubber vulcanization activator to the rubber is preferably 1 to 5:100, and more preferably 2 to 3: 100.

In the invention, the application method of the rubber vulcanization activator is preferably HG/T2404-2008 in the vulcanization process of the rubber.

The following examples are provided to illustrate the rubber vulcanization activators and the preparation thereof in detail, but they should not be construed as limiting the scope of the present invention.

Example 1

Weighing 20g of zinc sulfate and 30g of calcium terephthalate, dissolving the zinc sulfate in 100mL of water to obtain a zinc sulfate solution with the molar concentration of 0.2mol/L, ultrasonically dispersing the calcium terephthalate in 50mL of water for 30min to obtain a calcium terephthalate dispersion liquid with the solid content of 37.5%;

mixing the obtained zinc sulfate solution and the calcium terephthalate dispersion liquid at room temperature, and stirring for 1h to obtain a mixed dispersion liquid at the rotating speed of 2000 r/min;

dropwise adding 100mL of sodium hydroxide solution with the molar concentration of 0.4mol/L into the mixed dispersion liquid, stirring simultaneously, wherein the stirring speed is 500r/min, the dropwise adding time is 20 minutes, after the dropwise adding is finished, heating to 60 ℃ at the heating rate of 1 ℃/min, keeping the temperature, and continuously stirring for 1 hour to obtain mixed slurry;

and (3) sequentially carrying out water washing and suction filtration on the obtained mixed slurry for 3 times, then sequentially carrying out ethanol washing and suction filtration for 3 times, and carrying out aging treatment in an oven at 150 ℃ for 24 hours to obtain the rubber vulcanization activator.

And mixing the obtained rubber vulcanization activator with rubber according to the formula and the vulcanization method recorded in the national standard HG/T2404-2008, wherein the mass ratio of the rubber vulcanization activator to the rubber is 4:100, and after mixing for 48 hours, testing the tensile strength of the obtained vulcanized rubber according to the national standard HG/T528-one 1998, wherein the tensile strength is 27.8 MPa.

FIG. 1 is a standard X-ray diffraction pattern of hexagonal zinc oxide, FIG. 3 is an X-ray diffraction pattern of the rubber vulcanization activator obtained in example 1, and it can be seen from an analysis combining FIGS. 1 and 3 that the crystal grain of zinc oxide is 15 nm.

FIG. 2 is a scanning electron microscope photograph of the rubber vulcanization activator obtained in example 1, and it can be seen that zinc oxide is uniformly dispersed among calcium terephthalate without significant agglomeration.

The obtained rubber vulcanization activator was subjected to sequential scanning X-ray fluorescence, and the results are shown in Table 1.

TABLE 1 sequential scanning X-ray fluorescence spectroscopy analysis results of rubber vulcanization activators obtained in example 1

Analyte	Content (wt.)
		C	35.0060％
O	29.1515％
		Zn	16.3939％
Ca	14.6484％
		Na	2.5636％
S	1.7470％
		Al	0.3029％
Cd	0.0527％
		Fe	0.0392％
Zr	0.0205％
		K	0.0136％

As can be seen from the above data, the mass ratio of zinc oxide to calcium terephthalate in the rubber vulcanization activator prepared in this example is 1: 3.

example 2

Weighing 30g of zinc sulfate and 20g of calcium terephthalate, dissolving the zinc sulfate in 100mL of water to obtain a zinc sulfate solution with the molar concentration of 0.2mol/L, ultrasonically dispersing the calcium terephthalate in 50mL of water for 30min to obtain a calcium terephthalate dispersion liquid with the solid content of 28.6%;

mixing the obtained zinc sulfate solution and the calcium terephthalate dispersion liquid at room temperature, and stirring for 1.5h to obtain a mixed dispersion liquid at the rotating speed of 3000 r/min;

dropwise adding 100mL of sodium hydroxide solution with the molar concentration of 1mol/L into the mixed dispersion liquid, stirring simultaneously, wherein the stirring speed is 300r/min, the dropwise adding time is 60 minutes, after the dropwise adding is finished, heating to 80 ℃ at the heating rate of 5 ℃/min, keeping the temperature, and continuously stirring for 1.5 hours to obtain mixed slurry;

And mixing the obtained rubber vulcanization activator with rubber according to the formula and the vulcanization method recorded in the national standard HG/T2404-2008, wherein the mass ratio of the rubber vulcanization activator to the rubber is 2:100, and after mixing for 48 hours, testing the tensile strength of the obtained vulcanized rubber according to the national standard HG/T528-containing 1998, wherein the tensile strength is 27.3 MPa.

FIG. 4 is a scanning electron microscope photograph of the rubber vulcanization activator obtained in example 2, and it can be seen that zinc oxide is uniformly dispersed among calcium terephthalate without significant agglomeration.

FIG. 5 is an X-ray diffraction pattern of the rubber vulcanization activator obtained in example 2, and when analyzed in conjunction with FIGS. 1 and 5, the crystal grains of zinc oxide were 20 nm.

The obtained rubber vulcanization activator was subjected to sequential scanning X-ray fluorescence, and the results are shown in Table 2.

TABLE 2 sequential scanning X-ray fluorescence spectroscopy analysis results of rubber vulcanization activators obtained in example 2

Analyte	Content (wt.)
		Zn	33.6842％
O	26.0012％
		C	24.7368％
Ca	10.3158％
		Na	2.6238％
S	1.7233％
		Al	0.3451％
Cd	0.0352％
		Fe	0.0284％
Zr	0.0221％
		K	0.0203％

As can be seen from the above data, in the rubber vulcanization activator prepared in this example, the mass ratio of zinc oxide to calcium terephthalate is 1: 1.3.

example 3

Weighing 10g of zinc sulfate and 60g of calcium terephthalate, dissolving the zinc sulfate in 100mL of water to obtain a zinc sulfate solution with the molar concentration of 0.2mol/L, ultrasonically dispersing the calcium terephthalate in 100mL of water for 30min to obtain a calcium terephthalate dispersion liquid with the solid content of 37.5%;

dropwise adding 100mL of sodium hydroxide solution with the molar concentration of 1mol/L into the mixed dispersion liquid, stirring simultaneously, wherein the stirring speed is 4000r/min, the dropwise adding time is 30 minutes, after the dropwise adding is finished, heating to 60 ℃ at the heating rate of 1 ℃/min, keeping the temperature, and continuously stirring for 1.5 hours to obtain mixed slurry;

And mixing the obtained rubber vulcanization activator with rubber according to the formula and the vulcanization method recorded in the national standard HG/T2404-2008, wherein the mass ratio of the rubber vulcanization activator to the rubber is 3:100, and after mixing for 48 hours, testing the tensile strength of the obtained vulcanized rubber according to the national standard HG/T528-containing 1998, wherein the tensile strength is 28.1 MPa.

FIG. 6 is a scanning electron microscope photograph of the rubber vulcanization activator obtained in example 3, and it can be seen that zinc oxide is uniformly dispersed among calcium terephthalate without significant agglomeration.

The obtained rubber vulcanization activator was subjected to sequential scanning X-ray fluorescence, and the results are shown in Table 3.

TABLE 3 sequential scanning X-ray fluorescence spectroscopy analysis results for rubber vulcanization activators obtained in example 3

Analyte	Content (wt.)
		C	41.2281％
O	30.7018％
		Ca	17.1930％
Zn	5.6140％
		Na	2.5426％
S	1.6741％
		Al	0.3011％
Cd	0.0418％
		Fe	0.0334％
Zr	0.0301％
		K	0.0219％

As can be seen from the above data, in the rubber vulcanization activator prepared in this example, the mass ratio of zinc oxide to calcium terephthalate is 1: 12.

the foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, various modifications and decorations can be made without departing from the principle of the present invention, and these modifications and decorations should also be regarded as the protection scope of the present invention.

Claims

1. A preparation method of a rubber vulcanization activator comprises the following steps:

2. The method according to claim 1, wherein the mass ratio of the soluble zinc salt to the calcium terephthalate is (1: 5) to (10: 1).

3. The method of claim 1, wherein the alkaline solution comprises one or more of a NaOH solution, a KOH solution, and ammonia.

4. The method according to claim 1 or 3, wherein the alkali solution has a molar concentration of 0.2 to 2 mol/L.

5. The method according to claim 1, wherein the mixed dispersion and the alkaline solution are mixed by: and dropwise adding the alkaline solution into the mixed dispersion liquid at a dropping rate of 12.5-20 mL/min.

6. The method according to claim 1, wherein the aging treatment is carried out at a temperature of 100 to 200 ℃ for 5 to 24 hours.

7. The rubber vulcanization activator prepared by the preparation method of any one of claims 1 to 6, comprising calcium terephthalate and zinc oxide loaded on the surface of the calcium terephthalate.

8. The rubber vulcanization activator according to claim 7, wherein the mass ratio of zinc oxide to calcium terephthalate is 1 (1.3-12).

9. Use of a rubber vulcanization activator as claimed in claim 7 or 8 for rubber vulcanization.

10. The use according to claim 9, wherein the mass ratio of the rubber vulcanization activator to the rubber is (1-5): 100.