Shanghai Daoqin Plastics Co., Ltd.

         automotive 保险杠 is absorption and decrease outer impact force, anti 护车身 front rear safety plant/unit. in automotive 保险杠 application areas, polyolefin plastics has non important 位. automotive industrial development and engineering plastics in automotive industrial a large amount of application, polyolefin plastics formed is 保险杠 一 types important 基材, its not only tool has function, also plastics light features promote automotive industry light amount development. due to polyolefin tool has strong/high degree, rigid property / tough property good balanced, from safety degree upper 看, automotive 发生碰撞事故时 can to non important function, front rear 车体, from appearance upper 看, coating good polyolefin plastics can very and 车体结 combined in 一起, tool has very good decoration property, formed is decoration automotive outer type important parts.

        众 周知, due to polyolefin material non property, but also tool has non low surface force, generally coating material method 附 于 its surface, need to good can force, need 特殊 预处理 or selection coating material. coating polyolefin 基材时, coating material made and technology must and versus 匹配, therefore, polyolefin 基材 预处理, coating material formulation design and raw materials selection non important.

        1, 保险杠 coating material coating process current situation

         plastics surface in made formed process process in by demolding agent, or material 污染, coating front must 进行清洁处理, in strong/high force plant/unit in using/adopting acid property or alkali property 介质进行清洗, 如图1 示.

图1 plastics surface strong/high force process 示意

         polyolefin material (如PP基材) surface 预处理/ active can using/adopting 火焰, electrical 晕, and other or fluorine 化. most is Common 火焰预处理 is make short 暂 扫 部 parts surface, through oxidation make PP surface formed property 基团, make rear coating coating material easy 附. above surface active methods need equipment formed. remove outer, also can using/adopting chlorine polyolefin or force promote agent, this modified material can ensure coating material in non property polypropylene (PP) upper obtain good force. however has machine 含卤素化 combined material application already formed is 人们争议 话题. in Germany, large separation coating process is using/adopting di separation polyurethane ester 底漆结 combined active 化预处理 methods improve/increase PP保险杠 coating 装总体 can property. meanwhile, Germany 保险杠 use coating process automotive OEM coating 装 进展, in and color already large separation using/adopting water property coating material coating 装. its process process/workflow 如图2 示.

图2 Germany 保险杠 coating process 示意图

         in Japan, 保险杠 using/adopting coating process, large separation using/adopting chlorine polyolefin (简称CPO) or chlorine polyolefin (PO) improve/increase force. its process process/workflow 如图3 示.

图3 Japan 保险杠 coating process 示意图

        随 CPO and PO technology development, 逐渐出现 water property CPO and water property PO 底漆, can reduce VOC 排放, its process process/workflow 如图4 示.

图4 Japan 保险杠 water property CPO coating process 示意图

         in China, currently large separation 保险杠 coating process also is 以传统 solvent agent type coating material is 主. its process process/workflow 如图5 示.

图5 China 保险杠 coating process 示意图

         in recent years, 随 国 inner environmental protection regulations day 益严格, and environmental protection 意识普遍 improve/increase, solvent agent type positive fast speed toward environmental protection coating material system 转变, especially toward water property coating material direction. in addition, automotive OEM主 machine 厂也逐渐提出 plastics parts water property requirements, make automotive plastics use and color toward water property 化 转变越 越迫切.

        2 保险杠 use low VOC coating material coating system 示例

        2.1保险杠 use 底漆

        底漆 usually has shallow color and deep color, has using/adopting and color color similar or same color. main/primary function in has cover/cap plastics defect, can improve/increase 基材附 force. for/regarding 保险杠底漆 说, also need tool excellent heavy coating property, resistant water property, and low temperature resistant impact can force and other. for/regarding automotive 而言, 保险杠 also requirements tool has good safety function. therefore 保险杠 coating material also must tool 备一定 outer force function, from to for 驾驶员 and 乘车者 anti 护. polyurethane ester tough property positive can meet/satisfy this requirements, water property polyurethane ester property can 尤佳. 图6 is different coating for plastics 基材 保护效果实验.

图6 plastics coating high speed impact experiment/testing lower sheet/slice

        PP材质 保险杠本身 tool has strong/high degree and tough property, selection coating system need and tough property versus 匹配, can improve/increase overall coating property can and most 终 保护 function. therefore, polyurethane ester coating material as is 底漆, its tough property can very good meet/satisfy 保险杠 demand. this polyurethane ester usually use polyester or acrylic is resin, 搭配基于HDI type more acid ester as is solid agent 2K polyurethane ester system. in 火焰预处理 rear, can coating di separation polyurethane ester 底漆. this technology system in Europe already obtain formed application. if has 火焰预处理, must combined amount CPO(chlorine polyolefin) or PO(polyolefin) formed separation obtain for PP基材足够 附 force, this usually is day using/adopting technology system. year, inner day production, already 经开始沿 use Japan water property 保险杠底漆 technology.

        针 for certain machine has especially property can requirements, 例如保险杠配 sleeve/set overall coating material system need can through hot 蒸汽冲 testing (Hotsteamjet), generally sleeve/set 底漆会 selection di separation system can meet/satisfy requirements. 图7 is in 火焰预处理 front conditions lower, di separation and mono separation hot 蒸汽冲 testing 结果, 结果显示 left di separation testing excellent right mono separation 底漆.

图7 mono separation and di separation hot 蒸汽冲 comparison 实验

         Covestro R&D water property resin is polyolefin modified polyurethane ester dispersion 体(不含 chlorine), for has 任何预处理 PP plastics tool has excellent 良 附 can force, and resistant water property can good. and product comparison 详见图8. comparison 市售底漆1, Covestro water property tool has more excellent property can. and water property 底漆2 comparison, normal temperature water 浸泡24h rear, surface 不发白, 附 依然 can to 5B. is improve/increase plastics water property color spray coating efficiency (upper rate), decrease/reduce spray coating belt/tape coating material 浪费, using/adopting electrical spray coating, this need 底漆配 made formed conductive 底漆, in in add conductive material. its in most important or most Common is conductive 炭黑. water property conductive comparison 关注 则 is conductive property and long 期贮存 rear stability property, 包括底漆 黏 degree, color and conductive property and other stability property. new R&D polyolefin modified polyurethane ester dispersion in this several 方面均 performance excellent application can property, to lower coating material enterprise can.

图8 different 保险杠底漆附 force and resistant water comparison

        2.2保险杠 use color 漆

        保险杠 color main/primary function in excellent color 效果, resistant water weather resistance can, 层间结 combined force excellent, lubricating wet property can good. solvent agent type color formulation in has a large amount of has machine solvent agent (60%~70% above), is system in VOC排放 most large coating material. especially is has 一 特殊效果颜 material (aluminum powder or light powder) color 漆, its has machine solvent agent content ultra- 80%. currently, 保险杠 use water property polyurethane ester color 漆源于德系车. water property polyurethane ester tool has good material mechanical properties, especially is resistant high low temperature impact property can, tool has flexibility (soft 段) and hardness (hard 段) balanced property can, has a large amount of hydrogen structure, non combined used for 保险杠底 color formed film material. due to water property coating material tool has relatively large shrinkage property, therefore can more good metal material thin sheet/slice 平行排列, can provide relatively good 效果颜 material appearance.

         using/adopting aliphatic acid ester is raw materials water property polyurethane ester tool has excellent lightfast weather resistance. its in type aliphatic 二异氰 acid ester has HDI, IPDI, H12MDI. 保险杠 color formulation can using/adopting 基于HDI water property polyurethane ester is formed film material made 备, can to PP保险杠 excellent tough property and resistant impact property can.

        基于 aliphatic acid ester is raw materials polyurethane ester dispersion non combined used for 保险杠底 color formed film material. outer plastics parts color formulation can using/adopting PUD as is formed film material, can and amount acrylic emulsion mixed 拼以达 to balanced cost 目.

         in addition, used for 保险杠 water property color polyurethane ester dispersion 体, must tool good low temperature formed film property can, resistant water property can, 层间附 force and drying speed degree.

        2.3保险杠 use 清漆

        保险杠清漆需 tool has excellent appearance, chemical resistant product and weather resistance, 以保护保险杠不受 outer gas 候, outer 伤害, chemical product 侵蚀以 and material or 洗车时 刮蹭, in addition also and has good property. currently large separation 保险杠清漆都 is di separation polyurethane ester coating material system. di separation polyurethane ester can through Raw Materials selection 搭配, 匹配保险杠基材 tough property, and in 80℃ low temperature lower, can meet/satisfy uniform, high gloss, high saturated degree, and weather resistant chemical resistant product requirements. another, optimization di separation polyurethane ester tool has obvious 自修复 function, make by rear can 自修复 to has high gloss appearance. most usually use di separation polyurethane ester coating material is through acid ester 基团(—NCO) and resin in active property 羟基(—OH) reaction crosslinked, from to excellent film property can. use aliphatic more acid ester polyurethane ester system, tool excellent weather resistance; di separation polyurethane ester crosslinked rear formed ester can resistant multiple chemical product;氨 ester between also can formed hydrogen 键, make film hard flexibility, tool has resistant 石击, resistant scratch 甚至自修复 and other function;而 this function is automotive coating material requirements. 图9 is polyurethane ester coating film 自修复 process 示意图.

图9 polyurethane ester coating film 自修复 process

        保险杠 use system, currently solvent agent type di separation polyurethane ester coating material is 主. 2006 year has water property high light used for plastics coating 装, is due to can as property made, to application. in VOC regulations lower, is 进一步 reduce VOC排放, high solid formed is research hot 点. using/adopting low degree solid agent can use relatively less solvent agent can adjustment coating material 至施工黏 degree, significantly decrease/reduce solvent agent use, to relatively high solid 含. table/sheet 1 is Covestro launch can used for 保险杠 high solid formulation solid agent product.

         table/sheet 1保险杠清漆 commonly used solid agent

         in 保险杠清漆 system in, using/adopting low degree solid agent, not only can has reduce in has machine solvent agent content, reduce VOC排放, but also in property can 方面也 tool has very large improvement, 例如保 light property, force and resistant water property can. table/sheet 2 is using/adopting same water property mono separation 底漆, water property mono separation color and A组 separation, sample 1 use is standards poly solid agent, sample 2 using/adopting is low degree solid agent [m(N3600)∶m(N3900)=1∶1 mixed 拼].

         from table/sheet 2 can 看出, 40℃×10d resistant water testing rear can sample 2 保 light rate is 82.3%, high sample 1 76.6%. resistant water rear force testing in, sample 1 coating has light micro 掉落, force in 1~2 grade between, sample 2 use low degree solid agent rear, 切割边缘无 obvious 脱落, force ≤1 grade. this is due to low degree solid agent due to degree relatively low more easy to color 漆层甚至底漆层, from improve/increase force, obtain more good overall coating resistant water property can.

         table/sheet 2 different solid agent for overall coating property can effect/influence

        3 保险杠 coating material development trend

        随 automotive amount day growth, for sleeve/set plastics parts demand will day increase, automotive 保险杠 coating material demand will day expand large. this for/regarding industry upper step/link will belt/tape machine 遇. in China day 趋严格 environmental protection regulations lower, and environmental protection 意识 不断 reinforcement, automotive machine requirements parts and 车身主体配 sleeve/set, 不断推进 for and color water property development. but also in Germany Japan and other 发达国家, 保险杠 water property and color already formed application more year, this will accelerated 保险杠 coating material in China water property 化进程.

        随 new can automotive development, energy saving emission reduction rise grade, decrease light automotive heavy is has 效 办 method 之一, will automotive can can use more more plastics parts, especially for can achieve multiple plastics 基材附 良 good, can low temperature solid can achieve 一体化 coating polyurethane ester technology more more requirements, meet/satisfy for automotive production quality, efficiency and cost control.