The adhesion properties of stearic acid-loaded rubber compounds to brass-plated steel cords

The effect of stearic acid loading in rubber on the adhesion between rubber compounds and brass-plated steel cords was examined in respect to aging treatments and cure conditions. The adhesion interphase of a thin brass film/rubber compound containing stearic acid was investigated using an Auger electron spectrometer. The loading of stearic acid to rubber was not effective in the improvement of adhesion of rubber stock cured under optimum conditions, whereas it improved the adhesion property of premature cured samples by enhancing the physical property. High loading of stearic acid severely deteriorated the adhesion property, even at an unaged state due to the excessive formation of zinc sulfide. The loading of stearic acid did not affect the sensitivity of the rubber compound to humidity and thermal aging, but amplified the deterioration of adhesion when the rubber compound was subjected to salt solution aging, resulting in extremely poor adhesion. The effects of other ingredients and the aging treatment were also thoroughly examined.     

Effects of cure levels on adhesion between rubber and brass in the composites made up of rubber compound and brass-plated steel cord

The adhesion between rubber compound and brass-plated steel cord of rubber-brass composites with different cure levels was investigated in relation to the formation and growth of their adhesion interphase examined with AES spectroscopy. The optimum-cured adhesion sample showed a maximum pullout force, but the pullout forces of samples under-cured and over-cured were low. The adhesion property of under-cured adhesion samples enhanced with humidity aging due to further curing of rubber and supplementary growth of the adhesion interphase. Cure level exhibiting good adhesion was discussed based on the composition and structure of the adhesion interphase and the crosslinking density of the rubber layer attached to the interphase. This paper is dedicated to Professor Hyun-Ku Rhee on the occasion of his retirement from Seoul National University (Gon Seo).     

环氧化天然橡胶玻璃化转变温度与环氧化程度的关系

根据Ｖａｎ Ｋｒｅｖｅｌｅｎ 等提出的一些高聚物物理参数加合性原则,推导了环氧化天然橡胶（ＥＮＲ） 的玻璃化转变温度（Ｔｇ） 与环氧化程度（Ｂ） 的关系,并根据经验公式计算了不同环氧化程度ＥＮＲ 的Ｔｇ 。     

Effect of ZnO contents at the surface of brass-plated steel cord on the adhesion property to rubber compound

An effect of ZnO concentration at the surface of brass-plated steel cord on the adhesion property between a rubber compound and a brass-plated steel cord was investigated. Cord composition was determined by an Auger microscope with Ar ion sputtering. Two different steel cords were prepared; one (cord A) had higher ZnO concentration at the cord surface compared to the other (cord B). Pull-out force of unaged adhesion sample of cord A was lower than that of cord B. But the adhesion durability of the humidity-aged adhesion sample of cord A was better than the latter. Rubber coverage of the pull out cord for the unaged adhesion samples of cord A was poor, indicating insufficient formation of an adhesion layer. Pull-out force of the thermal-aged adhesion samples decreased with increasing aging time and that of cord A was lower than that of cord B. The enhancement of rubber coverage during initial aging period could be explained by an additional formation of copper sulfide at the adhesion interphase and an increase of modulus of rubber compound adjacent to the adhesion layer. With further increases of aging time, adhesion interphase grew excessively and the physical property of rubber compound deteriorated significantly, such that rubber coverage of adhesion samples decreased markedly with increasing aging time.     

镀铜钢丝与胶料粘合性能的影响因素

研究了19＃镀铜钢丝的表面处理方式、生产工艺及采用的粘合体系对镀铜钢丝与胶料粘合性能的影响。结果表明，不同生产工艺铁镀铜钢丝宜采用与其相适应的表面处理方式；冷拉钢丝需采用盐酸处理、表面清洁的回火钢丝无需进行处理即可获得良好的粘合性能；采用间苯二酚－甲醛粘合体系有利于提高镀铜钢丝与胶料的粘合性能。     

Effect of cure rate of rubber compound on the adhesion to copper-plated steel cord

Copper-plated steel cord was prepared and its adhesion properties to rubber compounds, which have different loading amounts of both sulfur and accelerator, were examined in comparison with brass-plated steel cord. The lower pullout force of copper-plated steel cord to the rubber compounds was shown compared with brass-plated steel cord. The copper-plated steel cord showed higher adhesion retention to rubber compounds than brass-plated steel cord against various hostile environments. The stability against both humidity aging and thermal aging, and the cause for the high adhesion retention of the copper-plated steel cord to rubber compounds, were discussed compared with those of the brass-plated steel cord. The pullout force of copper-plated steel cord to rubber compound is inversely correlated with cure rate after various aging treatments.     

On characterizing microscopically the adhesion interphase for the adhesion between metal and rubber compound Part III. Effect of brass-plating amount for brass-plated steel cord

Three kinds of brass-plated steel cords with different brass-plating amounts from 2.62 to 5.01 g/kg were prepared and their adhesion properties to rubber compounds were studied. Adhesion properties decreased with the increase in the brass-plating amount from 2.62 to 3.88 g/kg. Furthermore as the increase of brass-plating amount over 3.88%, adhesion property increased. The strong adhesion of brass-plated steel cord with low brass-plating amount to the rubber was shown not only after curing but also after hostile aging treatments. The good adhesion stability against humidity aging of adhesion property for brass-plated steel cord with low brass-plating amount to rubber compound was discussed in terms of the formation and growth of adhesion interphase determined by AES depth profile. The good adhesion stability of brass-plated cord with low brass-plating amount can be resulted from the suppression of the excessive growth of copper sulfide and the inhibition of dezincification due to the low brass-plating amount.     

Promotion effect of a chlorotriazine derivative on the adhesion between rubber compounds and a brass-plated steel cord

The adhesion between chlorotriazine derivative (TZ)-loaded rubber compounds and a brass-plated steel cord was studied to understand how TZ acted as an adhesion promoter. With the loading of the rubber compound with TZ, the cure rate became slow, but changes in the physical properties were not significant. An improvement in adhesion was obvious at a low TZ loading ranging from 0.5 to 2.0 phr. An adverse effect was observed with high loadings up to 8 phr and aging treatments for 15 days. Since the concentration of sulfur in the interphase of the rubber compound/ brass film adhesion samples after humidity aging was high for the rubber compound with high loadings of TZ, the acceleration of sulfide formation by TZ loading was confirmed. Lack of oxygen in the interphase indicated the conversion of zinc oxide to zinc sulfide in the rubber compound containing TZ. The control of zinc oxide formation in the adhesion interphase by TZ is suggested to be the reason for the adhesion promotion by TZ.     

p-Hydroxy-benzoic acid as an adhesion promoter for rubber compounds to a brass-plated steel cord

The adhesion between a p-hydroxy-benzoic acid (POB) containing rubber compounds and a brass-plated steel cord was investigated to understand the role of POB as an adhesion promoter. The cure rate slowed down when POB was added to the rubber compound, but changes in the physical properties were not significant. An improvement in adhesion was seen with a low loading of POB in the range of 0.5-1 phr, while an adverse effect was observed only with a high loading at 4 phr and a long aging time of 15 days. The adhesion interphase between a rubber compound and a thin brass film studied using AES showed an acceleration of the copper sulfide formation by POB incorporation, resulting in an enhancement of the adhesion. However, a higher POB loading as well as a longer aging time leads to a large increase in the migration of copper into the rubber and excessive growth of the zinc oxide layer, resulting in a decreased adhesion property.     

Boric acid ester as an adhesion promoter for rubber compounds to brass-plated steel cord

The adhesion between a boric acid ester (BAE) containing rubber compound and a brassplated steel cord was investigated to understand the role of BAE as an adhesion promoter. An improvement in adhesion was shown with the low loading of BAE in the range 0.5-1 phr, while significant decline of adhesion was not observed with high loading at 2 phr and a long aging time of 15 days. The interphase between the brass plated steel cord and the rubber compound studied using Auger electron spectroscopy (AES) showed a stabilized adhesion interphase by BAE incorporation, resulting in the enhancement of the adhesion retention.     

Stabilizing the adhesion interphase between rubber compounds and brass film by the addition of resorcinol formaldehyde resin to the rubber

The effect of resorcinol formaldehyde (RF) resin on the stability of the adhesion interphase between rubber compounds containing different amounts of RF resin and the thin brass film deposited on a glass plate was investigated under the conditions of humidity aging. The depth profiles of the adhesion interphase were examined by AES (Auger electron spectroscopy). In the unaged state, there was no significant difference in the adhesion interphase with varying content of RF resin, but the migration of copper and zinc to the bulk of the rubber during humidity aging was considerably suppressed with high levels of RF resin in the rubber compound. The pull-out force and rubber coverage of TCAT (tire cord adhesion test) samples also showed an improvement in the adhesion durability to humidity aging, caused by the addition of RF resin. The improvement in the adhesion stability to humidity aging obtained by adding RF resin to the rubber compound can be explained by a barrier formation effect, which prevents further migration of reactive materials inducing the degradation of the adhesion interphase.     

On characterizing microscopically the adhesion interphase for the adhesion between metal and rubber compound Part II. Effect of copper content for brass-plated steel cord

Three brass-plated steel cords with different copper contents from 51.4 to 75.5% were prepared and their adhesion properties to rubber compound were examined. Adhesion properties improved with the decrease in the copper content. The high adhesion of brass-plated steel cord with low copper content to the rubber was obtained after cure and after hostile aging treatments. The stability against humidity aging and the cause for the high adhesion of the brass-plated steel cord with low copper content were discussed in conjunction with the formation and growth of adhesion interphase determined by Auger electron spectroscopy depth profile. The excellent adhesion stability of brass-plated cord with low copper content can be explained by the suppression of the excessive growth of copper sulfide and the inhibition of dezincification due to the low copper content.     

钴盐对子午线轮胎帘布胶镀铜钢丝帘线之间粘合力的影响

研究了钴盐品种和用量对NR胶料性能及子午线轮胎帘布胶－镀钢钢丝帘线粘合力的影响,结果表明,加入不同品种钴盐的胶料性能无明显差别;过硫化时间的延长,含钴盐CN－10和CN－16的胶料与镀钢线帘线之间的粘合力明显下降;经热空气老化后不同品种钴盐均保持较好的耐热性能;经湿热蒸汽老化后钴盐CN－20.5和680C具有较高的粘合力保持率。随着钴盐CN－20.5用量的增大,可获得较高的初始粘合力,但耐热空气老化和耐湿热蒸汽老化性能下降明显,其用量以0.7－1.2份为最佳。     

Adhesion of carbon steel and natural rubber by functionalized silane coupling agents

This study characterized a method of adhesion between uncured natural rubber and carbon steels (CS) by the surface modification of the CS with silane coupling agents comprising amino, thiol, glycidoxy, and isocyanate organic functionality. The effects of the functionalization of the silane coupling agents on adhesion between CS and uncured natural rubber were investigated by X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, atomic force microscopy, and local nanoscale thermal analysis. The reaction mechanism among the CS, silane coupling agent, and natural rubber was studied, revealing that adhesion was optimized and cohesive failure achieved when 3-(trimethoxysilyl)propylamine (APS) was used to modify the CS. The CS was shown to be directly silanized by the silane coupling agents, but the reactions between the natural rubber and the silane coupling agents was dependent on silane functionality.     

Impact of adhesive ingredients on adhesion between rubber and brass-plated steel wire in tire

Proficiency on underlying mechanism of rubber-metal adhesion has been increased significantly in the last few decades. Researchers have investigated the effect of various ingredients, such as hexamethoxymethyl melamine, resorcinol, cobalt stearate, and silica, on rubber-metal interface. The role of each ingredient on rubber-metal interfacial adhesion is still a subject of scrutiny. In this article, a typical belt skim compound of truck radial tire is selected and the effect of each adhesive ingredient on adhesion strength is explored. Out of these ingredients, the effect of cobalt stearate is found noteworthy. It has improved adhesion strength by 12% (without aging) and by 11% (humid-aged), respectively, over control compound. For detailed understanding of the effect of cobalt stearate on adhesion, scanning electron microscopy and energy dispersive spectroscopy are utilized to ascertain the rubber coverage and distribution of elements. X-ray photoelectron spectroscopy results helped us to understand the impact of Cu_XS layer depth on rubber-metal adhesion. The depth profile of the Cu_XS layer was found to be one of the dominant factors of rubber-metal adhesion retention. Thus, this study has made an attempt to find the impact of different adhesive ingredients on the formation of Cu_XS layer depth at rubber-metal interface and establish a correlation with adhesion strength simultaneously.     

Improving adhesion between polyester cord and rubber by using glycidyl-POSS

Poly(ethylene terephthalate) (PET) cords are usually coated with epoxy and/or isocyanate solutions (like methylene diphenyl diisocyanate [MDI]) before resorcinol-formaldehyde-latex (RFL) to increase the adhesion efficiency of RFL. In this article, the addition of glycidyl polyhedral oligomeric silsesquioxane (GPOSS) as an adhesion promoter to PET cord was investigated for reinforcing PET cord/rubber interfacial adhesion. Therefore, GPOSS treated PET cords (GPOSS + MDI + RFL) were prepared in different process conditions like different GPOSS ratios and oven curing times and then vulcanized with rubber. RFL, GPOSS + RFL, MDI + RFL, and commercial epoxies treated PET cord samples were also prepared for comparison with GPOSS+MDI + RFL treated PET cord. The thermal, mechanical, and morphological properties of the treated PET yarn and their composites with rubber were investigated. It was seen that in the GPOSS coated PET yarns increased the stiffness and no change was observed in the tensile strength of the PET yarns. It was determined that the utilization of GPOSS in the PET cord improved the adhesion of the cord to rubber when compared with other treated PET cords via H-adhesion and strip peel adhesion tests. Especially, since adhesion values give better results than commercially used epoxies, GPOSS as an adhesion promoter can be recommended in the rubber industry.     

炭黑硬度对胶料与钢丝帘线粘合力的影响

研究炭黑N326粒子硬度对轮胎带束层胶料物理性能以及胶料与钢丝帘线粘合力的影响.结果表明,随着炭黑N326粒子硬度的增大,带束层胶料门尼粘度、MH、ML、邵尔A型硬度、定伸应力和拉伸强度增大,拉断伸长率减小,焦烧时间和正硫化时间缩短;炭黑N326粒子硬度对硫化胶与钢丝帘线粘合力影响较大,两者呈正比关系.     

On characterizing microscopically the adhesion interphase for the adhesion between metal and rubber compound part I. Effect of hexamethoxymethylmelamine in rubber compound

The adhesion between hexamethoxymethylmelamine (HMMM)-containing rubber compounds and brass-plated steel cords was studied to understand the role of HMMM as an adhesion promoter. No improvement in adhesion after cure was shown with loading of HMMM in the range 1.3–5.2?phr, while enhancement of adhesion retention after humidity aging was observed with loading of HMMM in the range 1.3–5.2?phr. The adhesion interphase between the brass-plated steel cord and the rubber compound subjected to humidity-aging treatment showed using Auger electron spectroscopy (AES) stabilized depth profile by HMMM incorporation as loading of HMMM, resulting in enhancement of adhesion retention.     

Effect of bonding systems and antioxidants on the adhesion between EPDM rubber and polyester fabric

Ethylene propylene diene monomer (EPDM) rubber mixes containing different types of bonding materials and various commercial antioxidants were used to evaluate the adhesion of EPDM rubber to polyester fabric. A new antioxidant was prepared by graft copolymerization of 1, 5-diaminonaphthalene (DAN) onto natural rubber (NR) in order to investigate its effect on adhesion. It was observed that EPDM mixes containing DAN grafted onto NR shows better adhesion levels than those containing commercial antioxidants. It is also clear that the new system has high resistance towards aging and ionizing radiation. The new NR-g-DAN acts not only to stabilize the rubber mix towards environmental conditions but also to improve adhesion to polyester fabric.     

镀层对钢丝帘线与橡胶粘合性能的影响

研究高铜镀层(铜质量分数为0.670)和低铜镀层(铜质量分数为0.635)钢丝帘线与橡胶的粘合性能.结果表明,高铜镀层钢丝帘线与橡胶的初始粘合性能较好,但其老化后粘合性能下降明显;只要胶料配方合理,低铜镀层钢丝帘线与橡胶的初始粘合性能可接近高铜镀层钢丝帘线,而其老化后粘合性能明显优于高铜镀层钢丝帘线.