阅读说明：本技术 一种低蠕变阻燃减振橡胶及其制备方法 (Low-creep flame-retardant vibration-damping rubber and preparation method thereof ) 是由 谭莲影 肖同亮 杨瑞蒙 王雪飞 程志 穆洪帅 刘权 余海文 肖程远 黄良平 于 2020-06-30 设计创作，主要内容包括：本发明公开了一种低蠕变阻燃减振橡胶及其制备方法,包括按重量份计的下述组分：生胶100份、改性短切纤维2-10份、补强填充剂20-60份和复合阻燃剂35-75份；生胶包括生胶A和生胶B,生胶A包括天然橡胶、顺丁橡胶或丁苯橡胶中的一种及以上,生胶B包括脱蛋白天然橡胶和/或天甲橡胶；改性短切纤维是由偶联剂改性的短切纤维,偶联剂的一端与短切纤维表面的羟基通过改性连接,偶联剂的另一端能够通过氢键与橡胶分子链结合。本发明不仅可以显著提高胶料的抗蠕变性能,使得橡胶减振制品在实际使用过程中能够长时间地保证尺寸稳定性,提高实际使用寿命,而且具有优异的阻燃性能,同时可保证胶料的其他性能可满足产品的技术要求。(The invention discloses a low-creep flame-retardant damping rubber and a preparation method thereof, wherein the low-creep flame-retardant damping rubber comprises the following components in parts by weight: 100 parts of raw rubber, 2-10 parts of modified chopped fibers, 20-60 parts of reinforcing filler and 35-75 parts of composite flame retardant; the raw rubber comprises raw rubber A and raw rubber B, the raw rubber A comprises one or more of natural rubber, butadiene rubber or styrene butadiene rubber, and the raw rubber B comprises deproteinized natural rubber and/or natural rubber; the modified chopped fiber is a chopped fiber modified by a coupling agent, one end of the coupling agent is connected with hydroxyl on the surface of the chopped fiber through modification, and the other end of the coupling agent can be combined with a rubber molecular chain through a hydrogen bond. The invention not only can obviously improve the creep resistance of the rubber material, ensure that the rubber vibration damping product can ensure the dimensional stability for a long time in the actual use process and improve the actual service life, but also has excellent flame retardant property, and can ensure that other properties of the rubber material can meet the technical requirements of the product.)

1. The low-creep flame-retardant damping rubber is characterized by comprising the following components in parts by weight: 100 parts of raw rubber, 2-10 parts of modified chopped fibers, 20-60 parts of reinforcing filler and 35-75 parts of composite flame retardant; the raw rubber comprises raw rubber A and raw rubber B, wherein the raw rubber A comprises one or more of natural rubber, butadiene rubber or styrene butadiene rubber, and the raw rubber B comprises deproteinized natural rubber and/or natural rubber; the modified chopped fiber is a chopped fiber modified by a coupling agent, one end of the coupling agent is connected with hydroxyl on the surface of the chopped fiber through modification, and the other end of the coupling agent can be combined with a rubber molecular chain through a hydrogen bond.

2. The low creep flame retardant damping rubber according to claim 1 wherein the coupling agent has an alkoxy group terminal and an amino group terminal, and the alkoxy group is connected to the hydroxyl group on the surface of the chopped fiber by dehydration condensation through hydrolysis to generate a hydroxyl group.

3. The low creep flame retardant damping rubber according to claim 2 wherein the coupling agent is KH 550.

4. The low-creep flame-retardant damping rubber according to any one of claims 1 to 3, wherein the mass ratio of the raw rubber A to the raw rubber B is 7:3-19: 1.

5. The low-creep flame-retardant damping rubber according to any one of claims 1 to 3, wherein the chopped fibers comprise one or more of carbon nanotubes, carbon fibers, glass fibers or basalt fibers, and the mass ratio of the chopped fibers to the raw rubber B is 1:7-1: 4.

6. The low-creep flame-retardant damping rubber according to any one of claims 1 to 3, wherein the reinforcing filler comprises one or more of carbon black, white carbon black, Qianwei powder, kaolin, calcium carbonate or pottery clay.

7. The low-creep flame-retardant vibration damping rubber according to any one of claims 1 to 3, wherein the composite flame retardant comprises modified octachloropropyl silsesquioxane, which is prepared by nucleophilic substitution of cysteine and octachloropropyl silsesquioxane.

8. The low creep flame retardant damping rubber according to claim 7 wherein the nucleophilic substitution is performed in the presence of an acid scavenger and a catalyst, the catalyst being an iodide salt.

9. The low creep flame retardant damping rubber according to claim 7 wherein the composite flame retardant further comprises one or more of graphene, aluminum hydroxide, zinc borate, zinc hydroxystannate, melamine cyanurate or ammonium polyphosphate.

10. A method for preparing the low-creep flame-retardant damping rubber according to any one of claims 1 to 9, which comprises the following steps:

firstly, mixing deproteinized natural rubber and/or natural rubber and modified chopped fibers to prepare short fiber master batch;

and then uniformly mixing the raw rubber A and the short fiber master batch, adding a reinforcing filler and a plasticizer for mixing, then adding a composite flame retardant for mixing, adding other additives, and finally vulcanizing to obtain the low-creep flame-retardant damping rubber.

Technical Field

The invention belongs to the field of rubber materials, and particularly relates to low-creep flame-retardant damping rubber and a preparation method thereof.

Background

Automobiles, trains, ships and airplanes are generally required to be equipped with rubber vibration reduction products for improving the smoothness of vehicle operation and reducing noise pollution during vehicle operation, thereby improving the comfort of passengers. The raw rubber used for the rubber vibration damping product is various in types, the consumption of the raw rubber is large, and the raw rubber comprises Natural Rubber (NR), Butadiene Rubber (BR), Styrene Butadiene Rubber (SBR), Isoprene Rubber (IR) and the like, and the rubber materials have good vibration damping and noise reduction functions, but have the phenomenon of creep increase in the actual use process. The creep property is an important performance parameter of the rubber vibration damping product, the creep magnitude is directly related to the dimensional stability and the service life of the rubber vibration damping product, and if the creep magnitude is too large, the operation safety of vehicles such as automobiles, trains and the like is directly influenced, so that the sizing material needs to be optimized, the creep resistance of the sizing material is improved, and the actual service life of the sizing material and the product is ensured.

In addition, with the stricter requirements of the railway industry on the performance of the train smoke and fire, particularly the promulgation of the EN45545-2 standard, the development of rubber materials meeting the flame retardant requirement is more and more urgent, if the rubber material meets the flame retardant requirement, a large amount of flame retardants of different types must be added, and the reduction of the performance of the rubber material and products is inevitably caused by the addition of the flame retardants, so that the flame retardants need to be modified and reasonably compounded for use, and the adverse effect of the flame retardants on the performance of the rubber material is reduced as much as possible on the premise of ensuring the qualified flame retardant performance.

Disclosure of Invention

The invention aims to solve the technical problem of overcoming the defects and shortcomings in the background art and provides low-creep flame-retardant damping rubber and a preparation method thereof.

In order to solve the technical problems, the technical scheme provided by the invention is as follows:

a low-creep flame-retardant damping rubber comprises the following components in parts by weight: 100 parts of raw rubber, 2-10 parts of modified chopped fibers, 20-60 parts of reinforcing filler and 35-75 parts of composite flame retardant; the raw rubber comprises raw rubber A and raw rubber B, wherein the raw rubber A comprises one or more of natural rubber, butadiene rubber or styrene butadiene rubber, and the raw rubber B comprises deproteinized natural rubber and/or natural rubber; the modified chopped fiber is a chopped fiber modified by a coupling agent, one end of the coupling agent is connected with hydroxyl on the surface of the chopped fiber through modification, and the other end of the coupling agent can be combined with a rubber molecular chain through a hydrogen bond.

Further, the coupling agent has an alkoxy group-containing terminal and an amino group-containing terminal, and the alkoxy group is connected to a hydroxyl group on the surface of the chopped fiber by dehydration condensation through hydrolysis to form a hydroxyl group.

Further, the coupling agent is KH 550.

Further, the mass ratio of the raw rubber A to the raw rubber B is 7:3-19: 1.

Further, the chopped fibers comprise one or more of carbon nanotubes, carbon fibers, glass fibers or basalt fibers, and the mass ratio of the chopped fibers to the raw rubber B is 1:7-1: 4.

Further, the reinforcing filler comprises one or more of carbon black, white carbon black, Qianwei powder, kaolin, calcium carbonate or argil.

Further, the composite flame retardant comprises modified octachloropropyl silsesquioxane, and is prepared by nucleophilic substitution of cysteine and octachloropropyl silsesquioxane.

Further, the nucleophilic substitution is carried out in the presence of an acid-binding agent and a catalyst, wherein the catalyst is an iodide salt.

Further, the composite flame retardant also comprises one or more of graphene, aluminum hydroxide, zinc borate, zinc hydroxystannate, melamine cyanurate or ammonium polyphosphate.

The preparation method of the low-creep flame-retardant damping rubber comprises the following steps:

firstly, mixing deproteinized natural rubber and/or natural rubber and modified chopped fibers to prepare short fiber master batch;

and then uniformly mixing the raw rubber A and the short fiber master batch, adding a reinforcing filler and a plasticizer for mixing, then adding a composite flame retardant for mixing, adding other additives, and finally vulcanizing to obtain the low-creep flame-retardant damping rubber.

Compared with the prior art, the invention has the beneficial effects that:

(1) the invention creatively uses the partially deproteinized natural rubber and/or the natural rubber without any solvent in the crude rubber agent, the deproteinized natural rubber can obviously improve the creep property and the thermal aging property of rubber materials, and the dimensional stability and the service life of rubber vibration reduction products in the actual use process are ensured; the rubber material can improve the dispersibility of the filler and improve the mechanical property and fatigue property of the rubber material; in addition, the polar group of the nylon can improve the bonding strength of the rubber material and metal, ensure the bonding firmness of the product in the actual use process and avoid the occurrence of the phenomenon of product bonding damage.

(2) According to the invention, the coupling agent modified chopped fiber is added into the filler, and the stress at definite elongation, creep property and abrasion resistance of the rubber compound are improved by utilizing the chopped fiber.

(3) According to the invention, a special mixing process is adopted, the modified chopped fibers and the deproteinized natural rubber and/or the natural rubber are mixed in an open mill, and the problems of difficult dispersion and easy orientation of the chopped fibers can be effectively solved; the addition of chopped fibers can greatly improve the creep and abrasion performance of the rubber compound.

(4) Modifying octachloropropyl silsesquioxane by using a modifier cysteine, introducing carboxyl and sulfydryl into a POSS molecular structure, wherein the carboxyl can be subjected to dehydration condensation with hydroxyl on the surface of a filler (such as white carbon black, chopped fibers and the like), and the sulfydryl participates in the vulcanization reaction process of the sizing material, so that the filler, the OCP-POSS and the sizing material are organically combined together, the flame retardant property of the sizing material is improved, and the adverse effect of a flame retardant on the mechanical property of the sizing material is reduced;

(5) according to the invention, a small amount of graphene is used in the flame retardant, and a certain proportion of polyphosphate and hydroxide is matched, and the carbon layer formed by the graphene in the combustion process is utilized to inhibit further spreading of smoke and fire, so that the flame retardant property of the rubber material is improved;

the low-creep flame-retardant damping rubber material with excellent performance and simple preparation method and the preparation method thereof provided by the invention not only can obviously improve the creep resistance of rubber materials, ensure that the rubber damping products can ensure the dimensional stability for a long time in the actual use process and improve the actual service life, but also have excellent flame-retardant performance, can meet the requirements of European Union EN45545-2R9HL2, and can ensure that other properties (such as strength and bonding) of the rubber materials can meet the technical requirements of products.

Detailed Description

In order to facilitate an understanding of the present invention, the present invention will be described more fully and in detail with reference to the preferred embodiments, but the scope of the present invention is not limited to the specific embodiments below.

Unless otherwise defined, all terms of art used hereinafter have the same meaning as commonly understood by one of ordinary skill in the art. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of the present invention.

Unless otherwise specifically stated, various raw materials, reagents, instruments, equipment and the like used in the present invention are commercially available or can be prepared by existing methods.

The low-creep flame-retardant damping rubber material of one specific embodiment of the invention comprises the following main components in percentage by mass: raw rubber: 100 parts of (A); zinc oxide: 3-10 parts; stearic acid: 1-3 parts; modified chopped fibers: 2-10 parts; reinforcing filler: 20-60 parts; plasticizer: 2-10 parts; composite flame retardant: 35-75 parts; an anti-aging agent: 2-7 parts; vulcanizing agent: 2-6 parts.

In a specific embodiment, the raw rubber used is a raw rubber mixture A comprising more than one of natural rubber, butadiene rubber and styrene butadiene rubber and a raw rubber mixture B of deproteinized natural rubber and/or natural rubber, wherein the mass ratio of the raw rubber mixture A to the raw rubber mixture B is between 7:3 and 19: 1.

In order to solve the problem of poor creep property of common rubber (such as NR, BR, SBR and blend rubber), a small amount of deproteinized natural rubber and/or natural rubber is added into common damping rubber. The characteristics of low creep, low stress relaxation, good fatigue resistance, excellent dynamic thermal property and excellent thermal oxidation aging property of the deproteinized natural rubber due to extremely low nitrogen content and ash content are utilized, so that the creep resistance and fatigue property of the sizing material and the vibration damping product, especially the creep property under a high-temperature condition, are improved, the dimensional stability of the rubber vibration damping product in the actual application process is ensured, and the actual service life of the rubber vibration damping product is prolonged. The Tianjia rubber is prepared by grafting and modifying natural rubber through methyl methacrylate, the Tianjia rubber and the natural rubber can be mixed in any proportion, the polar group carried by the Tianjia rubber is utilized to improve the dispersibility of a strong polar filler (such as white carbon black) in a rubber material, so that the mechanical property and the fatigue property of the rubber material are improved, in addition, the polar group of the Tianjia rubber can improve the bonding strength of the rubber material and a metal iron piece, the bonding firmness of a product in the actual use process is ensured, the phenomenon of bonding damage of the product is avoided, and the Tianjia rubber has good heat-resistant aging property, so that the actual service life of the product is improved.

In one embodiment, the chopped fibers used comprise one or more of carbon nanotubes, carbon fibers, glass fibers and basalt fibers, and the ratio of the chopped fibers to the mixture B is between 1:7 and 1: 4. The surfaces of the chopped fibers are required to be modified, and the modifier is a coupling agent gamma-aminopropyl-ethoxysilane (KH 550).

In order to further improve the creep property of the sizing material, the reinforcing filler of the sizing material can be added with a small amount of modified chopped fibers besides the traditional carbon black and white carbon black, the chopped fibers are modified by using a coupling agent KH550, and the problems of easy orientation and difficult dispersion of the chopped fibers are solved by adopting a special mixing process; the addition of the modified chopped fibers can block the movement of rubber molecular chains or chain segments, so that the creep property of the sizing material and the product is improved, and in addition, the chopped fibers can also improve the stress at definite elongation and the abrasion resistance of the sizing material.

The chopped fiber is modified by firstly soaking the chopped fiber in an acetone reagent, removing impurities and mucilage on the surface of the chopped fiber, then drying in a vacuum drying oven under the drying condition of 100 ℃ for 0.5h, removing the acetone reagent on the surface of the fiber, and then soaking the desized chopped fiber in a solution (the mass ratio of water to absolute ethyl alcohol in a solvent is 1:2-2:1) with the concentration of a coupling agent of 0.25-1.5%. Ethoxy in the molecular structure of KH550 is hydrolyzed to generate hydroxyl, and the hydroxyl on the surface of the fiber are subjected to dehydration condensation, so that KH550 molecules are grafted on the surface of the chopped fibers, amino at the other end of the molecular structure of KH550 can be combined with rubber molecular chains in a hydrogen bond mode, and the coupling agent KH550 plays a role of bridging between the chopped fibers and the rubber molecular chains, so that the chopped fibers and the rubber molecular chains are combined together, and the chopped fibers are uniformly dispersed in the rubber molecular chains, thereby improving the creep property of the sizing material and improving the stress at definite elongation and the abrasion performance of the sizing material.

In order to improve the problems of easy orientation and difficult dispersion of the chopped fibers, a special mixing process can be adopted, firstly, the modified chopped fibers and the deproteinized natural rubber and/or the natural rubber are mixed in an open mill according to a certain proportion, in order to solve the orientation problem, the thin passing triangular bag forming treatment is carried out for many times until short fibers cannot be seen in rubber materials, then, short fiber master batch is prepared, and then, the short fiber master batch and common raw rubber are added into an internal mixer or an open mill together for mixing.

In one embodiment, the reinforcing filler comprises one or more of carbon black, white carbon black, Qiangwei powder, kaolin, calcium carbonate and pottery clay, preferably carbon black and white carbon black, wherein the carbon black is preferably large-particle-size and high-structure carbon black, such as N990, N550 and N774 and new process carbon black BC 2123. When the white carbon black is added, a coupling agent Si-69 is also needed to be added for modifying the white carbon black, and the ratio of the addition amount of the coupling agent Si-69 to the white carbon black is 1:5-1: 12.

In one embodiment, the composite flame retardant comprises modified octachloropropyl silsesquioxane (Cys-CP-POSS), graphene, aluminum hydroxide (Al (OH)₃) Zinc borate, zinc hydroxystannate, Melamine Cyanurate (MCA) and ammonium polyphosphate (APP) in a total amount of 35-70 parts, wherein Cys-CP-POSS in an amount of 3-8 parts, graphene in an amount of 2-6 parts, aluminum hydroxide in an amount of 10-30 parts, zinc borate in an amount of 2-7 parts, zinc hydroxystannate in an amount of 2-10 parts, and a mixture C composed of Melamine Cyanurate (MCA) and ammonium polyphosphate (APP) in a total amount of 15-30 parts in a ratio of 2:3-3: 2; the ratio of Cys-CP-POSS to the mixture C is between 1:4 and 1:7, and the ratio of graphene to the mixture C is between 1:5 and 1: 8.

In order to improve the fireproof flame retardant performance of the rubber material and enable the rubber material to meet the requirements of EN45545-2 standard of European Union, modified octachloropropyl silsesquioxane and graphene can be introduced into a rubber flame retardant, the high-efficiency flame retardant performance of the octachloropropyl silsesquioxane and the graphene are utilized, a small amount of traditional flame retardants (polyphosphate, hydroxide, zinc hydroxystannate, zinc borate and the like) are matched, the addition amount of the traditional flame retardants can be greatly reduced, the adverse effect of the large amount of traditional flame retardants on the mechanical performance of the rubber material is reduced, the fireproof performance of the rubber material can meet the requirements of EN45545-2 on the premise of ensuring that the mechanical performance of the rubber material meets the use requirements of products, and the mechanical performance. OCP-POSS has a three-dimensional inorganic-organic hybrid structure with a chemical composition of (RSiO)_1.5)_nThe flame retardant is 0.7-3nm spherical, has reaction multifunctionality and excellent flame retardant property, is combined with filler (such as white carbon black) and raw rubber in the mixing process of rubber by modifying the flame retardant, improves the flame retardant property and solves the problem of the mechanical property reduction of rubber materials caused by surface inertia of common flame retardants. Graphene is an excellent flame retardant, has an excellent synergistic flame retardant effect when being compounded with polyphosphate and hydroxide (such as aluminum hydroxide and magnesium hydroxide) for use, can form a carbon layer in the burning process of rubber materials, can inhibit further burning of combustible materials, reduces the generation of smoke and heat, and has the characteristic of no toxicity, so that the smoke toxicity requirement can be met.

In one embodiment, octachloropropyl silsesquioxane (Cys-CP-POSS) is modified by nucleophilic substitution of cysteine (Cys), Cys and octachloropropyl silsesquioxane (OCP-POSS) in the presence of an acid-binding agent (Aba) and a catalyst (Cat.) to form Cys-CP-POSS according to the following reaction formula:

by modifying octachloropropyl silsesquioxane, amino in cysteine and chlorine in an OCP-POSS molecular structure are subjected to substitution reaction to generate novel semi-siloxane with carboxyl, secondary amino and mercapto trifunctional groups, wherein the carboxyl can be subjected to chemical reaction with a filler (such as white carbon black) with hydroxyl on the surface, and the mercapto can be subjected to chemical reaction with a rubber molecular chain, so that a flame retardant, the filler and the raw rubber molecular chain are organically combined together, and the adverse effect of the flame retardant on the performance of a rubber material can be reduced.

The specific operation method of the modification comprises the following steps: 1 molar amount of OCP-POSS, 8 to 9 molar amount of cysteine, 1 to 5 molar amount of acid binding agent, preferably 2 to 3 molar amount of catalyst and 1 to 5L of organic solvent are added into a reaction reagent bottle in sequence and reacted for 12 to 48 (preferably 18 to 36) hours at the temperature of 60 to 120 ℃. And after the reaction is finished, concentrating the solvent, and performing vacuum drying for 48 hours at normal temperature to obtain Cys-CP-POSS.

Preferably, the acid-binding agent is a basic carbonate such as potassium carbonate (K)₂CO₃) Sodium carbonate (Na)₂CO₃) And the like. Preferred catalysts are iodide salts such as potassium iodide (KI), sodium iodide (NaI), and the like. Preferred organic solvents are N, N-Dimethylformamide (DMF), N-dimethylacetamide (DMAc), Dimethylsulfoxide (DMSO), and the like.

In one embodiment, the plasticizer is one or more of naphthenic oil, paraffin oil and environment-friendly aromatic oil, preferably naphthenic oil and environment-friendly aromatic oil.

In one embodiment, the anti-aging agent comprises quinoline, p-phenylenediamine and one or more of protective wax and ultraviolet absorbent, and the anti-aging agents RD, 4020, microcrystalline wax and UV-531 are preferred.

In one embodiment the sulphurising agent comprises one of sulphur and insoluble sulphur, preferably insoluble sulphur.

In one embodiment, 1.5 to 5 parts of a promoter may also be added, the promoters used including thiazoles, sulfenamides and thiuram promoters, preferably promoters CZ and TBzTD.

If necessary, various additives such as processing aids, scorch retarders, etc. can be added to the low creep, vibration damping, and flame retardant rubber material of the present invention.

The invention aims to improve the creep resistance and the flame retardance of rubber damping products, and provides a damping rubber material which has excellent mechanical property and creep property and can meet the requirements of EN45545-2R9HL 2. The creep properties of the rubber compound are not only dependent on the type of raw rubber, but also on the type of filler and vulcanizing agent. According to the invention, deproteinized natural rubber and/or natural rubber are used in raw rubber, and a small amount of modified chopped fibers are added, so that the creep resistance of the rubber material is improved, and the thermal oxygen aging property, the adhesive property of the rubber material, the stress at definite elongation and the abrasion resistance of the rubber material and a product are improved, thereby prolonging the actual service life of the product. In order to improve the fireproof flame retardant property of the rubber material, the OCP-POSS modified product and the reasonable compounding use of the graphene, the polyphosphate and the hydroxide enable the fireproof property of the rubber material to meet the requirements of EN45545-2R9HL2, and meanwhile, the mechanical property of the rubber material can be ensured.

In one embodiment, the invention provides a method for preparing a low creep flame retardant damping rubber, comprising:

(1) the preparation process of the short fiber masterbatch comprises the following steps: firstly, deproteinized natural rubber, natural rubber and modified chopped fibers are added into a high-temperature open mill in proportion, mixing is carried out for 2-5min at the temperature of 120-130 ℃, and thin-pass triangular package beating treatment is carried out for many times in the mixing process until the chopped fibers cannot be seen in a rubber material, and then the short fiber master batch is obtained.

(2) The rubber material preparation process comprises the following steps: firstly, adding natural rubber, styrene butadiene rubber and the like and short fiber master batch into an open mill in proportion, mixing for 1-2 minutes at 50-70 ℃, then thinly passing, adding a reinforcing filler and a plasticizer after uniformly mixing, and mixing for 1-2 minutes; then adding the composite flame retardant at the temperature of 130-140 ℃, and mixing for 2-3 minutes; after being mixed evenly, the mixture is cooled to below 80 ℃, and then the anti-aging agent, the vulcanizing agent, the accelerant and the scorch retarder are added, and the mixture is sliced and naturally cooled. And vulcanizing after parking to prepare the required low-creep vibration-damping flame-retardant rubber material.

Comparative example 1

The low-creep flame-retardant vibration-damping rubber comprises the following components in parts by weight: 100 parts of natural rubber: 5 parts of zinc oxide; 2 parts of stearic acid; 2 parts of an anti-aging agent RD; 1 part of an anti-aging agent 4020; 2 parts of microcrystalline wax; 1.5 parts of ultraviolet absorbent UV-531; 30 parts of carbon black N774; 2 parts of graphene; 20 parts of aluminum hydroxide; 7 parts of zinc borate; 6 parts of zinc hydroxystannate; MCA, 12 parts; APP, 15 parts; naphthenic oil, 2 parts; 1.0 part of insoluble sulfur; 1.3 parts of accelerator CZ; 0.5 part of promoter TBzTD; 0.3 part of antiscorching agent CTP.