着色方法及其对物性的影响.doc

着色方法及其对物性的影响在塑料制品中有许多色彩鲜艳的制品。工程塑料虽不如通用塑料那样，但其色彩鲜艳的制品也不少见。其中，有些制品是由涂漆或印刷而成的，且大部分制品是对塑料原料进行着色而成。那么，着色对塑料的物性有怎样的影响呢？此次，许多客户也来信提出了这样的询问，下面对于着色与物性之间的关系做一介绍着色的方法首先对着色方法的种类进行说明。目前，用于塑料中的着色方法有以下四种方法。黑色着色多为色母料法或混合料法，色泽鲜艳的着色主要是采用比较容易选择颜色的表面覆盖法这种方法是在成型时，把颜色浓度高的、被称之为“色母料”的有色材料混合到希望着色的材料中。该方法操作简便，并且可通过色母料量的调整，随意改变颜色的浓淡。它经常被用于黑色着色（黑灰色）。不过，有些种类的颜色很难制作色母料，有时调不出用户希望的颜色。这种方法是把颜料混合在粒料中进行挤出而制成有色粒料。色调最稳定就是其最大的优点。不过，由于需要挤出工序，故着色所需费用支出趋于最高的倾向。这种方法是把溶有颜料的涂料喷涂在希望着色的粒料表面上进行覆盖。由于可轻而易举地制成着色级制品，故可广泛满足用户的要求。它是着色级制品中最常用的着色方法，而且容易操作。只是与混合法相比，颜料的分散性稍差。这种方法是在成型时，把颜料和粒料混合使用的方法。该法操作困难，而且成型后的清扫非常麻烦。同时，颜料的分散性也不好，且容易产生色调不匀。虽然这种方法只要有颜料就能做得到，但鉴于以上原因，实际中不大被采用。对物性的影响颜料对物性的影响因颜料种类和添加量的不同而异。颜料分为有机和无机两大类。在象工程塑料那样高熔点的树脂中，主要采用无机类金属化合物颜料，添加量一般为0.5%左右。它虽然因目标颜色的不同而改变，但最多时也“极少”有超过1%。由于原则上它属于在成型品中混入的异物，所以不会对物性造成好的影响。但因添加量少、体积又小，故其物性不会发生极度恶化。下面，对每种物性因着色而产生的影响分别试做了汇总，请参照。（1） 机械物性因着色，会使强度有一定降低、韧性也可能下降。作为一个实例，下表对夺钢M90S的自然色制品及其着色品（红、黄色）进行了比较。夺钢M90S的物性 （着色品系色母料M90-07与夺钢M90S的掺合物） 物性单位自然色品红黄拉伸强度MPa62.561.161.0拉伸率%35.526.827.0弯曲强度MPa86.679.580.5弯曲模量MPa250022802310简支梁冲击强度kJ/m另外，在玻璃纤维类增强品级中，白色着色（加入钛系颜料增加白度）制品有可能造成机械物性下降增大的趋势，请注意。（2） 耐热性树脂本身不发生变化，但是，从添加入的着色剂中释放的分解物有增多的可能性。（3） 摩擦磨耗特性虽然一般认为基本上没有变化，但是，目前有些地方使用含碳量高的色母料（聚乙烯基），当使用这种含碳量高的色母料时会混入大量聚乙烯，有可能因发生剥离等现象而使滑动性能恶化。为了防止发生这种情况，关键就是要使用聚合物基与成型材料的聚合物基相同的色母料。有关适用于本公司材料的色母料，务请到本公司销售部或主页上进行咨询。（4） 耐候性耐候性因颜色的不同而有大幅度变化。这不是由于树脂性能发生变化所致，而是因着色而使光能的吸收程度发生变化的缘故。此页按各种颜色对耐候性数据进行了汇总，请参照。夺钢耐候性 Duranex耐候性 （5） 电气特性彩色制品与自然色制品的电气特性几乎没有差别。当为黑色制品时，由于使用了碳黑而有一定影响（导电性制品和防带电性制品除外）。此页对自然色制品与黑色制品Duranex3300的电气特性进行了比较，请参照。3300的电气特性 其它（问与答）问：颜料中使用的化合物含有有害的重金属吗？答：这要看颜料的种类，不能一概而论。如果是本公司的材料，请将您想知道的金属以及材料的品级和颜色号码通知本公司的销售部或主页咨询处。我们在调查、落实之后，给您作出答复。问：根据材料的颜色，可知道所含颜料的成分吗？答：这实际是做不到的。因为单独使用颜料是很少见的，一般来说，都是将多种颜料组合使用。因此，只看颜色是不能知道其成分的Effect of coloring methods on properties of plasticsThere are so many colorful products made of plastics. Not a few products even made of engineering plastics are also colorful, though not so many as those made of general-purpose plastics. Although some of them are painted or printed, most of them are molded with colored plastic raw material. What is the influence of coloring on the properties of plastics? This time we are going to explain the effect of coloring on the properties of plastics to you.Coloring methodsAt first, the types of coloring methods are explained.Following 4 types of coloring methods are used for plastics. Coloring in black is usually done by means of either a masterbatch or a compounding method, while plastic materials of other colors are mainly made by means of a surface-coating method where color matching is relatively easy.This is a coloring method in which plastic material to be colored is mixed with so-called masterbatch which is the colored material of a high pigment content. Masterbatches can be handled easily, and the depth of color can also be easily controlled by the amount of masterbatches to be added. They are often used for coloring in black or gray. Depending on the kinds of pigments, however, it is sometimes difficult to make masterbatches, or to match up to the colors wanted by customers.This is a method to make colored pellets by means of mixing pigment with the pellets of natural color and then extruding the mixture. The highest consistency in color is the most important advantage of this method. However, this is usually the most expensive coloring method, since it is inevitably accompanied by extrusion process. In this method, organic solvent in which pigment is dispersed is sprayed on the surfaces of natural pellets to be colored to form colored coating. Since colored pellets can be easily available by this method, this method is very popular among customers, and used most widely particularly for colorful moldings. Handling is also easy, but the dispersion of pigment by this method is slightly inferior to that by compounding method.This is a method to just mix pellets and pigment prior to molding. The handling is not so easy and the cleaning after the molding is also troublesome. The dispersion of pigment is poor, and the consistency of color is not good either. Although this method is applicable if only pigment is available, actually this method is not used so often because of the reasons mentioned above.Effect of coloring on propertiesThe effect of pigment on the properties of moldings depends on the type and the amount of pigment added. There are two types of pigments i.e. organic and inorganic, and inorganic metal compounds are mainly used for the resin of high melting point such as engineering plastics. The amount of pigment added is usually around 0.5%. Although this changes depending on color, it is very rare that this exceeds 1%. Since pigment is basically foreign matter contaminating molded products, it never has any good influence on their properties. However, since the amount of pigment added is very limited and its particle size is very small, it does not happen that the properties of the moldings are badly spoiled by the addition of pigment.The effect of coloring on each property is summarized below for your reference.(1) Mechanical propertySlight reduction in strength and some reduction in tenacity may possibly be induced by coloring. The comparison between Duracon M90S natural and colored (red and yellow) is shown below as an example.Properties of Duracon M90S (Colored material is a blend of M90S and masterbatch M90-07) PropertyUnitNaturalRedYellowTensile strengthMPa62.561.161.0Tensile elongation%35.526.827.0Flexural strengthMPa86.679.580.5Flexural modulus of elasticityMPa250022802310Charpy impact strengthkJ/mAlso, please note that the reduction in mechanical properties tends to become more significant, when glass-fiber reinforced plastic is colored in white by the addition of white pigment made of titanium compounds to increase whiteness.(2) Heat resistanceColoring does not affect the heat resistance of resin itself. However it is possible that the amount of decomposition products from the added pigment increases in high temperature environment.(3) Friction and wear propertyBasically no change is anticipated in this property. However, when polyethylene is used as the base resin of masterbatch to facilitate high carbon content, molding material blended with such masterbatch is inevitably contaminated with considerable amount of polyethylene. In such a case, frictional property may possibly be deteriorated due to the phenomenon of delamination etc. Therefore, it is necessary to use masterbatch whose base resin is same as that of molding material, in order to prevent such problems. For masterbatch which is suitable for our material, please make inquiry to our sales offices or through HP. (4) Weather resistanceWeather resistance largely depends on color. However, this is not caused by the change in the property of resin, but rather caused by the degree of the absorption of light energy which is different color by color. Data on the weather resistance color by color are summarized in the following pages for your reference.Weather resistance of Duracon Weather resistance of Duranex (5) Electrical propertyThere is hardly any change in electrical properties between natural and colored material. The electrical properties of black material is, however, somewhat different from those of natural material due to the effect of carbon black added, except for electrically conductive grades and antistatic grades. The comparison of electrical properties between natural and black Duranex 3300 is shown in the following pages for your reference.Electrical properties of Duranex 3300Other topics in the form of Q