High-melting-point rubber protective wax and preparation method thereof

Abstract

The invention relates to high-melting-point rubber protective wax and a preparation method thereof. The problems of low melting point and poor high-temperature protection performance of the existing rubber protection wax are mainly solved. The wax is characterized by comprising the following components in percentage by mass: 10-25% of fully refined paraffin, 15-40% of semi-refined paraffin, 30-50% of microcrystalline wax, 0-20% of Fischer-Tropsch wax, 0.5-2.0% of polyethylene wax and 0.2-0.8% of an antioxidant. The preparation method comprises the following steps: preparing a mother solution from part of fully-refined paraffin, semi-refined paraffin and an additive in proportion, mixing and stirring, and transferring a sample into a blending kettle after the sample is uniformly molten; and adding the rest paraffin, microcrystalline wax and Fischer-Tropsch wax into a blending kettle according to the proportion, blending, stirring, sampling and analyzing to be qualified, cooling, filtering, and pumping into a granulator for granular forming. The high-melting-point rubber protection wax can play a long-term protection role in a wide temperature range, especially under a high-temperature condition, and effectively prevents rubber products from aging and cracking due to weather influence.

Description

Technical field:

[0001] The invention relates to the technical field of rubber protective wax, in particular to a high melting point rubber protective wax and a preparation method thereof. Background technology:

[0002] During the use of rubber products, they are affected by factors such as ozone, oxygen, light, heat, radiation, and mechanical stress in the air, which cause aging. Among them, ozone has the greatest destructive effect. Ozone in the air has high chemical activity and can react with unsaturated double bonds in rubber, causing double bonds to break and form carbonyl groups, which reduces the relative molecular mass of rubber and deteriorates its performance. Therefore, rubber protective wax needs to be added during the processing of rubber. Its protective mechanism is to form a protective film by migrating and diffusing to the rubber surface to prevent rubber from contacting with ozone, thereby playing a static ozone protection role.

[0003] Rubber protective wax is mostly made of paraffin wax, microcrystalline wax and special additives (such as polyethylene wax, etc.). The composition of the wax film formed by the migration of protective wax to the surface of vulcanized rubber is greatly affected by the ambient temperature, which is mainly due to the different melting points of alkanes with different carbon atoms in the protective wax. The melting point of rubber protective wax on the market is generally 60-78℃, and the high temperature protection performance is poor, which affects the service life of the tire.

[0004] The main production method of rubber protective wax is the blending method. In industrial production, many companies directly put the raw materials into the blending kettle and stir them at high temperature. Petroleum wax products and additives have different temperature requirements. Generally, the heating temperature of petroleum wax is controlled at about 100°C, while additives generally need a temperature above 130°C to melt. This can easily cause uneven mixing of wax products with different melting points. In addition, some paraffin raw materials are exposed to high-temperature air for a long time and oxidize, which increases the oil content of the product. The higher the oil content of the protective wax, the lower the tensile strength, the easier it is for the protective wax film to break, and the oil is easily oxidized. Some branched alkanes are oxidized to fatty esters, etc., causing discoloration and affecting the quality of rubber products.

[0005] Chinese patent CN 101092517 discloses a rubber protective agent, which is characterized by the following ingredients and weight percentages: 16-36% low melting point paraffin wax; 32-44% high melting point paraffin wax; 20-36% petroleum microcrystalline wax; 0.5-3% EVA polymer; 1-3% synthetic polyethylene wax; 2-5% cationic surfactant; 1-3% antioxidant. The rubber protective agent has a drop melting point of 60.0-70.0°C, which is relatively low, and is not suitable for high temperature protection of rubber products, and its protective performance is limited.

[0006] Chinese patent CN 109777128 A discloses a high isoparaffin rubber protective wax and its preparation method, which comprises 5-15 parts of fully refined paraffin wax, 5-15 parts of semi-refined paraffin wax, 50-90 parts of microcrystalline wax, 0.5-5 parts of EVA polymer, 0-15 parts of Fischer-Tropsch wax, and 0.5-3 parts of lubricating additive. The isoparaffin content in the prepared high isoparaffin rubber protective wax is 40-56%, and the total hydrocarbon carbon peak is C 35 -C 37 , freezing point 68.0-78.0°C. The protective wax has good adhesion, but the preparation method mixes all the raw materials together, paraffin is easily oxidized at high temperature, the product quality is affected, the energy consumption is high, and the production cost is increased.

[0007] Chinese patent CN 103254480 B discloses a rubber protective wax and a preparation method thereof, wherein the protective wax comprises, by weight percentage: 20-40% fully refined paraffin, 25-45% semi-refined paraffin, 20-53% microcrystalline wax, and 0.5-5% ethylene-vinyl acetate copolymer EVA. The protective wax has a freezing point of 65.0-70.0°C, and a normal alkane content of 60-70%. The protective wax has a low freezing point and does not have high temperature protection performance. In addition, there is also the problem of mixing all raw materials together during preparation, which wastes energy, affects product quality, and increases production costs.

[0008] The rubber protective wax reported in the above patent has a low melting point and poor high temperature protection performance. The production method is to put the raw materials and additives into a blending kettle together and stir them at high temperature, which easily causes uneven mixing of wax products with different melting points, increases energy consumption, and has high production costs. Some paraffin raw materials are exposed to high temperature air for a long time and oxidize, which increases the oil content of the product and affects the quality of rubber products. Therefore, it is urgently needed to provide a high melting point rubber protective wax and a production method thereof. Summary of the invention:

[0009] The purpose of the present invention is to overcome the problems of low melting point and poor high temperature protection performance of the existing rubber protective wax in the background technology, and to provide a high melting point rubber protective wax. The high melting point rubber protective wax, by controlling its melting point and carbon number distribution, forms a protective wax film with moderate migration speed, strong adhesion, good flexibility and uniform density on the rubber surface, which can play a long-term protective role in a wide temperature range, especially under high temperature conditions, and effectively prevent rubber products from aging and cracking due to weather factors. The present invention also provides a preparation method of the high melting point rubber protective wax.

[0010] In order to achieve the above-mentioned purpose, the first aspect of the present invention provides a high melting point rubber protective wax, the mass percentage content of each component of which is: 10-25% of fully refined paraffin, 15-40% of semi-refined paraffin, 30-50% of microcrystalline wax, 0-20% of Fischer-Tropsch wax, 0.5-2.0% of polyethylene wax, and 0.2-0.8% of antioxidant; the polyethylene wax and antioxidant are additives.

[0011] Preferably, the fully refined paraffin wax is grade 52 # -70 # At least one of paraffin wax.

[0012] Preferably, the fully refined paraffin is preferably 58 # -68 # Paraffin, 58 of which # -62 # The main peak of the total carbon number distribution of paraffin is C 27 -C 33 , non-normal alkane content 10-30%, oil content less than 0.8%, kinematic viscosity (100℃) 3.5-5.5mm 2 / s; 64 of them # -68 # The main peak of the total carbon number distribution of paraffin is C 34 -C 39 , non-normal alkane content 25-45%, oil content less than 0.8%, kinematic viscosity (100℃) 5.5-7.5mm 2 / s.

[0013] Preferably, the semi-refined paraffin is 52 # -70 # At least one of paraffin wax.

[0014] Preferably, the semi-refined paraffin is 58 # -68 # At least one paraffin wax, 58 # -62 # The main peak of the total carbon number distribution of paraffin is C 27 -C 33 , non-normal alkane content (mass fraction, the same below) 10-30%, oil content less than 2.0%, kinematic viscosity (100℃) 3.5-5.5mm 2 / s; 64 of them # -68 # The main peak of the total carbon number distribution of paraffin is C 34 -C 39 , non-normal alkane content 25-45%, oil content less than 2.0%, kinematic viscosity (100℃) 5.5-7.5mm 2 / s.

[0015] Preferably, the microcrystalline wax is grade 70 # -85 # At least one of microcrystalline waxes, the 70 # -85 # Microcrystalline wax non-normal alkane content 50-80%, oil content less than 2.0%, kinematic viscosity (100℃) 7.0-15mm 2 / s.

[0016] The Fischer-Tropsch wax is a methylene polymer; the relative molecular mass is 500-1000, the melting point is 70-95°C, the non-normal alkane content is 25-45%, the oil content is less than 1.5%, and the kinematic viscosity (100°C) is 5.5-12mm 2 / s; The above 70-95℃ Fischer-Tropsch wax has good compatibility with petroleum wax, which can not only increase the melting point of the protective wax but also reasonably distribute the carbon number.

[0017] Preferably, the polyethylene wax has a relative molecular mass of 1500-2000, a melting point of 105-120°C, and a viscosity (cps 140°C) of 300-500mPa·S; adding the polyethylene wax with the above indexes can significantly improve the melting point and viscosity of the rubber protective wax, and enhance its adhesion and density on the rubber surface.

[0018] The antioxidant is 2,6-di-tert-butyl-p-cresol.

[0019] Another aspect of the present invention provides a method for preparing a high melting point rubber protective wax, comprising the following steps:

[0020] Calculate the amount of each component according to the ratio of the above raw materials;

[0021] Part of fully refined paraffin, semi-refined paraffin and additives are mixed into mother liquor in proportion, the mother liquor mixing temperature is 130-150°C, mixed and stirred at 50-100r / min for 30-60min, and the samples are transferred to the blending kettle after being sampled and observed to be uniformly melted;

[0022] The remaining fully refined paraffin wax, semi-refined paraffin wax, microcrystalline wax and Fischer-Tropsch wax are added into a blending kettle in proportion for blending. The blending temperature is 100-120°C. The mixture is stirred at 50-100r / min for 45-60min. After the blending is completed and the sampling and analysis are qualified, the mixture is cooled, filtered and the wax liquid is pumped into a granulator for granular molding to obtain a high melting point rubber protective wax.

[0023] Preferably, the mixing ratio of the partially fully refined paraffin wax, semi-refined paraffin wax and additives is 5-10:1.

[0024] Preferably, the blending kettle needs to be supplied with nitrogen as a protective gas during the blending period.

[0025] Compared with the above background technology, the present invention has the following beneficial effects:

[0026] 1. The carbon number distribution and the ratio of normal and iso-alkanes in rubber protective wax will affect the migration ability of protective wax and its protective effect. The carbon number distribution and the ratio of normal and iso-alkanes in this product are reasonable, and the carbon peak is at C 35 -C 37 The non-normal alkane content is about 38-44%. It has a wide protection temperature range and can form long-term protection. Especially at a high temperature of 40-50°C, it has excellent anti-ozone erosion protection effect. It is suitable for tires, shoes, conveyor belts and other rubber products.

[0027] 2. The 70-95°C Fischer-Tropsch wax added in the present invention has good compatibility with petroleum wax, which can not only increase the melting point of the protective wax but also reasonably distribute the carbon number. In addition, the polyethylene wax added in the present invention has a relative molecular mass of 1500-2000, a melting point of 105-120°C, and a viscosity (cps 140°C) of 300-500mPa·S; adding the polyethylene wax with the above indicators can significantly increase the melting point and viscosity of the rubber protective wax, and enhance its adhesion and density on the rubber surface.

[0028] 3. The raw materials of this product are widely available, and the production process is simple. Nitrogen and separate blending protection are used to prevent the wax from being oxidized and increasing its oil content during the high-temperature blending process. The oil content of the product of the present invention is less than 1.0%, and it has good compatibility with rubber, and has no obvious effect on the vulcanization characteristics and physical properties of rubber, thereby ensuring product quality.

[0029] 4. This production process mixes high-melting-point additives and low-melting-point ordinary paraffin separately to avoid uneven mixing of high-melting-point additives and paraffin, which can reduce energy consumption and save production costs. It is suitable for both intermittent small-batch production and continuous industrial production. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Attached Figure 1 The present invention is a process flow chart of preparing rubber protective wax according to an embodiment of the present invention.

[0031] In the figure: 1-mother liquor kettle feeding port, 2-mother liquor kettle, 3-mother liquor pump, 4-blending kettle feeding port, 5-blending kettle, 6-filter, 7-molding pump, 8-heat exchanger, 9-granulator. Specific implementation method:

[0032] The present invention will be further described below in conjunction with the accompanying drawings and embodiments:

[0033] A high melting point rubber protective wax, wherein the mass percentage of each component is: 10-25% of fully refined paraffin wax, 15-40% of semi-refined paraffin wax, 30-50% of microcrystalline wax, 0-20% of Fischer-Tropsch wax, 0.5-2.0% of polyethylene wax, and 0.2-0.8% of antioxidant; the polyethylene wax and the antioxidant are additives.

[0034] The fully refined paraffin wax meets the technical requirements of GB / T 446. # -70 # Paraffin, preferably 58 # -68 # Paraffin, 58 of which # -62 # The main peak of the total carbon number distribution of paraffin is C 27 -C 33 , non-normal alkane content 10-30%, oil content less than 0.8%, kinematic viscosity (100℃) 3.5-5.5mm 2 / s; 64 of them # -68 # The main peak of the total carbon number distribution of paraffin is C 34 -C 39 , non-normal alkane content 25-45%, oil content less than 0.8%, kinematic viscosity (100℃) 5.5-7.5mm 2 / s.

[0035] The semi-refined paraffin wax meets the technical requirements of GB / T 254. # -70 # Paraffin, preferably 58 # -68 # Paraffin, 58 of which # -62 # The main peak of the total carbon number distribution of paraffin is C 27 -C 33 , non-normal alkane content (mass fraction, the same below) 10-30%, oil content less than 2.0%, kinematic viscosity (100℃) 3.5-5.5mm 2 / s; 64 of them # -68 # The main peak of the total carbon number distribution of paraffin is C 34 -C 39 , non-normal alkane content 25-45%, oil content less than 2.0%, kinematic viscosity (100℃) 5.5-7.5mm 2 / s.

[0036] The microcrystalline wax meets the 70% requirement of the technical index of NB / SH / T 0013. # -85 # Microcrystalline wax, other indicators 70 # -85 # Microcrystalline wax non-normal alkane content 50-80%, oil content less than 2.0%, kinematic viscosity (100℃) 7.0-15mm 2 / s.

[0037] The Fischer-Tropsch wax, methylene polymer, is a solid wax prepared by Fischer-Tropsch synthesis, with a relative molecular mass of 500-1000, a drop melting point of 70-95° C., a non-normal alkane content of 20-45%, an oil content of less than 1.5%, and a kinematic viscosity (100° C.) of 5.5-12 mm 2 / s.

[0038] The polyethylene wax can improve the melting point of the protective wax product, control the wax film forming and adhesion, with a relative molecular mass of 1500-2000, a melting point of 105-120°C, and a viscosity (cps 140°C) of 300-500mPa·S. The antioxidant, 2,6-di-tert-butyl-p-cresol, enhances the anti-thermal oxidative aging effect of the protective wax.

[0039] like Figure 1 As shown, a preparation process of a high melting point rubber protective wax is as follows: it includes a mother liquid kettle 2, and the mother liquid kettle 2 is provided with a mother liquid kettle feeding port 1; the mother liquid kettle 2 is connected to a blending kettle 5 through a mother liquid pump 3, and the blending kettle 5 is provided with a blending kettle feeding port 4; the bottom pipeline of the blending kettle 5 is connected to a filter 6, a molding pump 7, a heat exchanger 8 and a granulator 9 in sequence.

[0040] A method for preparing a high melting point rubber protective wax comprises the following steps:

[0041] Calculate the amount of each component of each raw material according to the proportion; add the calculated part of fully refined paraffin and semi-refined paraffin into the mother liquid kettle 2 through the mother liquid kettle feeding port 1 to prepare the mother liquid, and add a certain proportion of additives (polyethylene wax, antioxidant). The mother liquid is configured in a ratio of fully refined paraffin and semi-refined paraffin: additives of 5-10:1, the mother liquid mixing temperature is 130-150℃, and the mixing is stirred at 50-100r / min for 30-60min. After sampling and observing that the sample is evenly melted, it is transferred to the blending kettle 5 through the mother liquid pump 3. The remaining paraffin wax (fully refined paraffin wax and semi-refined paraffin wax), microcrystalline wax and Fischer-Tropsch wax are charged into the blending kettle 5 through the blending kettle feeding port 4 in proportion, and the mixing temperature of the blending kettle is heated to 100-120°C by steam. The mixing is stirred at 50-100r / min for 45-60min. Nitrogen is required as a protective gas during the blending period. The wax liquid is pumped into the granulator 9 through the filter 6, the molding pump 7 and the heat exchanger 8 for granular molding to obtain a high melting point rubber protective wax.

[0042] The properties of the high melting point rubber protective wax prepared by the present invention are as follows: the drop melting point is 80-86°C; the non-normal alkane content is 35-45%; the main peak value of the total carbon number distribution is C 35 -C 37 ; Carbon number distribution C 25 -C 29 Content 8-16%, C 30 -C 34 Content 26-34%, C 35-C 39 Content 30-38%, C 40 -C 49 Content 16-24%; oil content not more than 2.0%; kinematic viscosity (100℃) 6.5-8.5mm 2 / s.

[0043] The drop melting point is measured according to GB / T 8026-2014; the main peak value of the total carbon number distribution, the carbon number distribution and the non-normal alkane content are measured according to SH / T 0653-2021; the oil content is measured according to GB / T 3554-2008; and the kinematic viscosity is measured according to GB / T265-1998.

[0044] Embodiment 1:

[0045] A high melting point rubber protective wax and its production method: 58 # Fully refined paraffin (6.2%), melting point 58.3°C, non-normal alkane content 12.4%; 64 # Semi-refined paraffin (14.8%), melting point 65.1℃, non-normal alkane content 29.3%; and polyethylene wax (1.6%) with a melting point of 115℃; antioxidant 2,6-di-tert-butyl-p-cresol (0.5%) were added to the mother liquor kettle to prepare the mother liquor. The mother liquor mixing temperature was 135℃, and the mixture was stirred at 80r / min for 60min, and then transferred to the blending kettle. The remaining 58 # Fully refined paraffin (17.3%); 64 # Semi-refined paraffin (4.6%); 70 # Microcrystalline wax (44%), melting point 70.9°C, non-normal alkane content 59%; 90 # Fischer-Tropsch wax (11%), melting point 90.4°C, non-normal alkane content 37.2%; added into a blending kettle for blending, the blending temperature is 110°C, mixed and stirred at 70r / min for 60min, in order to prevent the petroleum wax from oxidizing and increasing the oil content, nitrogen needs to be passed as a protective gas during the blending period, after sampling and analysis are qualified, cooled and filtered to obtain the high melting point rubber protective wax.

[0046] Embodiment 2:

[0047] A high melting point rubber protective wax and its production method: 60 # Fully refined paraffin (4%), melting point 61.1°C, non-normal alkane content 22.7%; 64 #Semi-refined paraffin (16%), melting point 65.1℃, non-normal alkane content 29.3%; and polyethylene wax (1.5%) with a melting point of 105℃; antioxidant 2,6-di-tert-butyl-p-cresol (0.5%) were added to the mother liquor kettle to prepare the mother liquor. The mother liquor mixing temperature was 140℃, mixed and stirred at 60r / min for 45min, and then transferred to the blending kettle. The remaining 60 # Fully refined paraffin (9%); 64 # Semi-refined paraffin (22%); 70 # Microcrystalline wax (33%), melting point 70.9°C, non-normal alkane content 59%; 95 # Fischer-Tropsch wax (14%), melting point 95°C, non-normal alkane content 42%; added into a blending kettle for blending, the blending temperature is 110°C, mixed and stirred at 70r / min for 55min, in order to prevent the increase of oil content of petroleum wax due to oxidation, nitrogen needs to be passed as protective gas during blending, after sampling and analysis, cooled and filtered, the high melting point rubber protective wax is obtained.

[0048] Embodiment 3:

[0049] A high melting point rubber protective wax and its production method: 58 # Fully refined paraffin (5%), melting point 58.3°C, non-normal alkane content 12.4%; 64 # Semi-refined paraffin (7%), melting point 65.1℃, non-normal alkane content 29.3%; and polyethylene wax (0.9%) with a melting point of 110℃; antioxidant 2,6-di-tert-butyl-p-cresol (0.3%) were added to the mother liquor kettle to prepare the mother liquor. The mother liquor mixing temperature was 130℃, and the mixture was stirred at 60r / min for 45min, and then transferred to the blending kettle. The remaining 58 # Fully refined paraffin (13%); 64 # Semi-refined paraffin (24.6%); 80 # Microcrystalline wax (41.2%), melting point 80.4°C, non-normal alkane content 63.8%; 70 # Fischer-Tropsch wax (8%), melting point 70°C, non-normal alkane content 24.6%; added into a blending kettle for blending, the blending temperature is 100°C, the mixing and stirring time is 50 minutes at 70r / min, in order to prevent the increase of oil content of petroleum wax due to oxidation, nitrogen needs to be passed as a protective gas during blending, after sampling and analysis are qualified, cooled and filtered to obtain the high melting point rubber protective wax.

[0050] Embodiment 4:

[0051] A high melting point rubber protective wax and its production method: 60 # Fully refined paraffin (3%), melting point 61.1°C, non-normal alkane content 22.7%; 62 #Semi-refined paraffin (12%), melting point 62.7℃, non-normal alkane content 26.2%; and polyethylene wax (1.0%) with a melting point of 105℃; antioxidant 2,6-di-tert-butyl-p-cresol (0.5%) were added to the mother liquor kettle to prepare the mother liquor. The mother liquor mixing temperature was 130℃, and the mixture was stirred at 60r / min for 40min, and then transferred to the blending kettle. The remaining 60 # Fully refined paraffin (10.2%); 62 # Semi-refined paraffin (12%); 85 # Microcrystalline wax (32.6%), melting point 85.9°C, non-normal alkane content 75.2%; 70 # Fischer-Tropsch wax (28.7%), melting point 70°C, non-normal alkane content 24.6%; added into a blending kettle for blending, the blending temperature is 100°C, the mixing and stirring time is 50 minutes at 60r / min, in order to prevent the increase of oil content of petroleum wax due to oxidation, nitrogen needs to be passed as a protective gas during blending, after sampling and analysis are qualified, cooled and filtered to obtain the high melting point rubber protective wax.

[0052] In order to illustrate the advantages of the present invention, Examples 1-4 and 70 of the present invention are # The technical indicators of microcrystalline wax, control wax and Antilux111 protective wax, which is highly recognized in the market, are compared as shown in Table 1 below.

[0053] Comparative Example

[0054] Patent CN 103254480A discloses a rubber protective wax in Example 3, wherein the fully refined paraffin wax is 64 # Fully refined petroleum wax, melting point is 65.2℃, normal alkane content is 63.7%; the semi-refined paraffin is 62 # Semi-refined petroleum wax, melting point 62.5 ° C, normal alkane content 69.1%; the microcrystalline wax is 75 # Microcrystalline wax, melting point 74.1°C, n-alkane content 44.6%, and 2.0% EVA copolymer.

[0055] Table 1

[0056]

[0057] As can be seen from Table 1, compared with the comparative samples, the melting point of the rubber protective wax droplets of Examples 1-4 of the present invention is 80-86°C, which is higher, and has a stronger protective effect in the temperature range of 40-50°C that is susceptible to ozone attack; the non-normal alkane content is 35-45%; the main peak of the total carbon number distribution is C 35 -C 37 , carbon number distribution C 25 -C 29 Content 8-16%, C30 -C 34 Content 26-34%, C 35 -C 39 Content 30-38%, C 40 -C 49 The content is 16-24%, the carbon number distribution is reasonable, the protection temperature range is wide, and it is suitable for ultra-long-term ozone protection at -10℃-50℃; the oil content is not more than 1.0%, the product quality is stable, it is not easy to oxidize and discolor, and does not affect the quality of rubber products.

[0058] The present invention embodiments 1-4 and 70 # Microcrystalline wax, control wax and Antilux111 protective wax were added as additives to the tire sidewall formula for mixing and vulcanization. The addition amount was 1.5 phr (parts by mass, 1.5 parts of protective wax were added to every 100 parts of rubber) to investigate their effects on the mechanical properties of the rubber, static ozone protection properties at different temperatures, and atmospheric aging properties.

[0059] Test 1: Physical properties before and after aging

[0060] The physical and mechanical properties of the vulcanized rubber were tested in accordance with relevant standards such as GB / T 528, GB / T 529, and GB / T 531. The hot air aging performance of the vulcanized rubber was tested in accordance with GB / T 3521, with the aging conditions being 100°C × 72h. The results of the physical and mechanical properties of the vulcanized rubber are shown in Table 2.

[0061] Table 2

[0062]

[0063] As can be seen from Table 2, the hardness, tensile strength, elongation at break and tear strength of the vulcanized rubber using the rubber protective wax of the present invention are similar to those of the vulcanized rubber of the comparative sample, but the absolute values ​​of the change rate of tensile strength, elongation at break and tear strength after aging are smaller than those of the comparative sample, indicating that the product of the present invention has a more obvious advantage in hot air aging performance.

[0064] Test 2: Static ozone aging resistance at 40°C

[0065] The ozone aging performance test of the vulcanized rubber was conducted in accordance with GB / T 7762-2014 "Static tensile test of vulcanized rubber or thermoplastic rubber for resistance to ozone cracking". The test conditions were 20% pre-stretching, 72 hours of light and ozone-free conditioning, 50 pphm of ozone concentration, and a test temperature of 40°C. The ozone aging of the rubber was observed at 24h, 48h, and 72h, and the results of the ozone aging performance of the rubber protective wax (40°C) are shown in Table 3.

[0066] Table 3

[0067]

[0068]

[0069] From Table 3, we can see that static ozone aging at 40℃, 70 # The microcrystalline wax has cracked to varying degrees, while the rubber protective wax prepared according to Examples 1-4 of the present invention has no cracking within 72 hours, which is consistent with the ozone resistance of the comparative example and Antilux111.

[0070] Test 3: 50℃ static ozone aging resistance

[0071] The ozone aging performance test of the vulcanized rubber was conducted in accordance with GB / T 7762-2014 "Static tensile test of vulcanized rubber or thermoplastic rubber for resistance to ozone cracking". The test conditions were 72 hours of light and ozone-free conditioning under a pre-stretching condition of 20%, an ozone concentration of 50 pphm, and a test temperature of 50°C. The ozone aging of the rubber was observed at 24 hours, 48 ​​hours, and 72 hours, and the results of the ozone aging performance (50°C) of the rubber protective wax are shown in Table 4.

[0072] Table 4

[0073] serial number Example 1 Example 2 Example 3 Example 4 <![CDATA[70 # Microcrystalline wax]]> Comparative Example Antilux111 24h No cracks No cracks No cracks No cracks There are cracks There are cracks There are cracks 48h No cracks No cracks No cracks No cracks There are cracks There are cracks There are cracks 72h No cracks No cracks No cracks No cracks There are cracks There are cracks There are cracks

[0074] It can be seen from Table 4 that when static ozone aging is performed at 50°C for 24 hours, # Microcrystalline wax, comparative example and Antilux111 have shown cracking to varying degrees. The rubber protective wax prepared according to Examples 1-4 of the present invention has no cracking within 72 hours. Compared with the comparative samples, the rubber protective wax prepared by the present invention has a high drop melting point, a reasonable carbon number distribution, and is significantly better than other similar products in terms of high temperature ozone aging resistance.

[0075] Test 4: Weathering resistance

[0076] The vulcanized rubber sheet was placed in outdoor air for 15 months and the surface condition was observed. The test conditions were: ambient temperature was -30℃-40℃, the test piece was stretched 50%, tilted 45 degrees and placed in an outdoor natural environment. The weather aging resistance results are shown in Table 5.

[0077] Table 5

[0078]

[0079]

[0080] It can be seen from the experimental results in Table 5 that the rubber protective wax prepared according to Examples 1-4 of the present invention has significantly better weathering resistance than similar products at home and abroad.

[0081] The utility consumption and production cost of the rubber protective wax production method of the present invention and the production method of the comparative example were compared using process simulation software.

[0082] According to the ratio and method of Example 3 in the comparative patent CN 103254480B, weighed fully refined paraffin wax and semi-refined paraffin wax are put into a reactor, slowly heated to 140°C, stirred at 70r / min for 20min after all the materials are melted, microcrystalline wax and EVA polymer are added, stirred for 60min, and after all the materials are melted, they are passed through a filter to filter out impurities and then cooled, and granulated by a molding machine to obtain rubber protective wax.

[0083] Taking 1000kg of product as an example, the electricity fee is calculated at 0.75 yuan / kWh, 1.0MPa steam is 160 yuan / ton, and nitrogen is 1 yuan / cubic meter. The utility consumption and production cost results for a single production are shown in Table 6.

[0084] Table 6

[0085] Material Name unit Example 1 Example 2 Example 3 Example 4 Comparative Example Electricity (380V) kW 25 24 22 21 17 1.0MPa steam t 0.25 0.27 0.2 0.19 0.55 Nitrogen <![CDATA[Nm 3 ]]> 2.5 2.5 2.5 2.5 - Estimated production cost Yuan 80 75.6 60.6 56.53 96.4

[0086] It can be seen from Table 6 that since the high melting point additive and the low melting point ordinary paraffin wax are blended separately, the utility consumption and production cost of the rubber protective wax prepared according to Examples 1-4 of the present invention are significantly lower than those of the existing blending production method.

[0087] It can be seen from Examples 1-4 that the rubber protective wax of the present invention has a high drop melting point and a reasonable carbon number distribution, so that it forms a protective wax film with strong adhesion, good flexibility, uniformity and density on the rubber surface, which can play a long-term protective role in a wide temperature range, especially under high temperature conditions, and effectively prevent rubber products from aging and cracking due to weather factors. At the same time, the production method provided is simple, the energy consumption and production cost are low, the product has low oil content and good quality, and is suitable for both intermittent small batch production and continuous industrial production.

[0088] It should be noted that the embodiments described above are only used to explain the present invention and do not constitute any limitation to the present invention. The present invention has been described with reference to typical embodiments, but it should be understood that the words used therein are descriptive and explanatory words, rather than restrictive words. The present invention may be modified as specified within the scope of the claims of the present invention, and the present invention may be revised without departing from the scope and spirit of the present invention. Although the present invention described therein relates to specific methods, materials and embodiments, it does not mean that the present invention is limited to the specific examples disclosed therein, on the contrary, the present invention can be extended to all other methods and applications with the same functions. Therefore, the content of the present invention is not limited to the examples listed in the embodiments, and any equivalent transformations taken by ordinary technicians of the art to the technical solution of the present invention by reading the specification of the present invention are all covered by the claims of the present invention.

Claims

1. A high melting point rubber protective wax, characterized in that: The mass percentage content of each component is: 10-25% of fully refined paraffin, 15-40% of semi-refined paraffin, 30-50% of microcrystalline wax, 0-20% of Fischer-Tropsch wax, 0.5-2.0% of polyethylene wax, and 0.2-0.8% of antioxidant; the polyethylene wax and antioxidant are additives.

2. The high melting point rubber protective wax according to claim 1, characterized in that: The fully refined paraffin wax is grade 52 # -70 # At least one of paraffin wax.

3. The high melting point rubber protective wax according to claim 2, characterized in that: The fully refined paraffin is preferably 58 # -68 # Paraffin, 58 of which # -62 # The main peak of the total carbon number distribution of paraffin is C 27 -C 33 , non-normal alkane content 10-30%, oil content less than 0.8%, kinematic viscosity at 100℃ 3.5-5.5mm 2 / s; 64 of them # -68 # The main peak of the total carbon number distribution of paraffin is C 34 -C 39 , non-normal alkane content 25-45%, oil content less than 0.8%, kinematic viscosity at 100℃ 5.5-7.5mm 2 / s.

4. The high melting point rubber protective wax according to claim 1, characterized in that: The semi-refined paraffin wax is 52 # -70 # At least one of paraffin wax.

5. The high melting point rubber protective wax according to claim 4, characterized in that: The semi-refined paraffin is 58 # -68 # At least one paraffin wax, 58 # -62 # The main peak of the total carbon number distribution of paraffin is C 27 -C 33 , non-normal alkane content 10-30%, oil content less than 2.0%, kinematic viscosity at 100℃ 3.5-5.5mm 2 / s; 64 of them # -68 # The main peak of the total carbon number distribution of paraffin is C 34 -C 39 , non-normal alkane content 25-45%, oil content less than 2.0%, kinematic viscosity at 100℃ 5.5-7.5mm 2 / s.

6. The high melting point rubber protective wax according to claim 1, characterized in that: The microcrystalline wax is grade 70 # -85 # At least one of microcrystalline waxes, the 70 # -85 # Microcrystalline wax non-normal alkane content 50-80%, oil content less than 2.0%, kinematic viscosity at 100℃ 7.0-15mm 2 / s; the Fischer-Tropsch wax is a methylene polymer; the relative molecular mass is 500-1000, the melting point is 70-95°C, the non-normal alkane content is 25-45%, the oil content is less than 1.5%, and the kinematic viscosity at 100°C is 5.5-12mm 2 / s.

7. The high melting point rubber protective wax according to claim 1, characterized in that: Polyethylene wax, relative molecular weight 1500-2000, melting point 105-120℃, viscosity 300-500mPa·S at 140℃; The antioxidant is 2,6-di-tert-butyl-p-cresol.

8. A method for preparing a high melting point rubber protective wax according to any one of claims 1 to 7, characterized in that: The following steps are involved: Calculate the amount of each component according to the ratio of the above raw materials; Part of fully refined paraffin, semi-refined paraffin and additives are mixed into mother liquor in proportion, the mother liquor mixing temperature is 130-150°C, mixed and stirred at 50-100r / min for 30-60min, and the samples are transferred to the blending kettle after being sampled and observed to be uniformly melted; The remaining fully refined paraffin wax, semi-refined paraffin wax, microcrystalline wax and Fischer-Tropsch wax are added into a blending kettle in proportion for blending. The blending temperature is 100-120°C. The mixture is stirred at 50-100r / min for 45-60min. After the blending is completed and the sampling and analysis are qualified, the mixture is cooled, filtered and the wax liquid is fed into a granulator for granular molding to obtain a high melting point rubber protective wax.

9. The method for preparing the high melting point rubber protective wax according to claim 8, characterized in that: The mixing ratio of the partially fully refined paraffin wax, semi-refined paraffin wax and additives is 5-10:

1.

10. The method for preparing the high melting point rubber protective wax according to claim 8, characterized in that: The blending kettle needs to be supplied with nitrogen as a protective gas during the blending period.

Images