丙烯酸树脂的基本面

丙烯酸树脂的基本面, UL Prospector, 罗纳德·Lewarchik, 4/2016:

涂料使用 丙烯酸树脂 涂料行业的聚合物技术领先吗. 从历史上看 醇酸 漆面几十年来一直处于涂料行业的领先地位. 丙烯酸被用于建筑涂料, product finishes for original equipment manufacture including 汽车 (OEM), refinish, 以及特殊用途的涂料.

丙烯酸树脂主要是基于 丙烯酸酯异丁烯酸甲酯 单体提供良好的耐候性, 耐水解, 表面应用的光泽和颜色保持. 由于它们的多功能性和性能, acrylic 涂料 account for over 25% of all 涂料 和 global 销售 approaching $25 billion. Acrylic resins can be thermoplastic or thermosett 和 are used in organic solvent born, 水传播的, 粉末和辐射固化涂料

表一-非功能性均聚物的Tg
表一-非功能性均聚物的Tg

Three broad classes of liquid 涂料 utilizing 丙烯酸树脂 include 热塑性,热固性和水性. Many 丙烯酸树脂 may also include other vinyl monomers such as 苯乙烯 or 醋酸乙烯酯 主要是为了降低成本. Acrylic monomers have a lower Tg than their analogous 异丁烯酸甲酯 monomers (for example compare the Tg for n-butyl 丙烯酸酯 versus n-butyl 异丁烯酸甲酯 see Table I 和 Table II). 如表二所示, the glass transition temperature of the monomers selected for synthesis of a resin can be selected to enhance multiple properties that may include weather resistance, 抗湿性, 氧气渗透, 灵活反应, 治疗和硬度. 除了, acrylics can be functionalized with a variety of monomers to provide improved adhesion to metal, or to react for example with aminoplast or isocyanate crosslinkers.

acrylics_table_2 
表二Tg与物性的关系

热塑性丙烯酸聚合物 (TPA) in general have excellent properties including exterior durability. Such resins were widely used in 汽车 OEM 和 Refinish topcoats from the 50’s to the 70’s, but their use has dramatically declined due to the high molecular weight necessary to provide properties, they require a high amount of organic solvent to enable air atomized spray application. 因此,这些涂料适用于重量约20%的固体. Thermoplastic resins typically use a high level of methyl 异丁烯酸甲酯 in their 聚合物 脊梁提供卓越的硬度和外观耐久性.

图一-聚MMA和聚MA的结构 
图一-聚MMA和聚MA的结构

热固性丙烯酸树脂(TSA) are designed with functional monomers to either react with themselves when exposed to heat or moisture, 或与交联剂形成交联膜. Thermoset resins as a group are lower molecular weight 和 thus have higher application solids. 一次交联, as a class they offer films with excellent resistance to organic solvents, moisture 和 UV light 和 do not soften appreciably when exposed to moderately high temperatures as thermoplastics do.  An example of 丙烯酸单体 with functional groups that can be used to functionalize acrylic 聚合物s to provide properties such as crosslinking, self-crosslinking, 附着力或颜料润湿性的改善见表三.

表III -功能性丙烯酸单体 
表III -功能性丙烯酸单体

Being able to functionalize an 丙烯酸树脂 with a wide range of reactive moieties provides the ability to tailor the performance of the resin backbone to provide improved adhesion over a variety of substrates, improved pigment wetting 和/or the ability to provide crosslinking or self-crosslinking. 其他丙烯酸单体也可用于传递磺酸, 或者丙烯酸树脂的磷酸功能.

Being able to functionalize an 丙烯酸树脂 with a wide range of reactive moieties provides the ability to tailor the performance of the resin backbone to provide improved adhesion over a variety of substrates, improved pigment wetting 和/or the ability to provide crosslinking or self-crosslinking. 其他 丙烯酸单体 are also available to impart sulfonic acid, 或者丙烯酸树脂的磷酸功能.

氨基甲酸酯功能丙烯酸 can also be made for example by reacting an isocyanate functional acrylic with hydroxypropyl carbamate. Many of the acrylics in the category of functionalized 丙烯酸树脂 are used in 汽车 OEM 和 refinish clearcoats to provide an excellent combination of mar resistance, 耐化学性和光稳定性.

 

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认证绿色索赔增加价值 & 涂料行业的品牌认知度

文章由澳门买球排行App总裁撰写, 罗纳德·Lewarchik, 最初发表在UL勘探者.

Whether 涂料 are sold directly to consumers or business to business, UL’s study: Under the Lens: Claiming Green – The influence of green product claims on purchase intent 和 br和 perception 揭示了合法的第三方, 绿色认证要求 contribute to the attractiveness of a product 和 comm和 a higher price because of enhanced br和 perception. 调查结果值得注意, 70%的美国人说他们正在寻找更环保的产品, 和 67% of business decision makers indicate sustainability is an important factor when making decisions for their organizations.

避免误导

然而, many manufacturers misrepresent their products by claiming they are green for the purposes of enhancing 销售. In 2012, 联邦贸易委员会修订了其绿色指南, the agency’s core set of guidelines to help marketers avoid making misleading environmental claims. 《澳门买球》现在更加具体和规范, 使联邦贸易委员会更容易起诉“洗绿者”.”因此, if a green claim is considered to be deceptive in the eyes of the FTC, 这既存在财务风险,也存在法律风险.

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流,平 & 水性涂料的粘度控制

Ron Lewarchik is a contributing author to UL Prospector 和 publishes articles monthly. 请继续阅读他的专家发现“流,流平。 & 《澳门买球》

流, leveling 和 viscosity stability can be very challenging 和 problematic in 水传播的 ambient cure 和 baked finishes. 这些问题不仅会影响包的稳定性, but also have a profound effect on appearance during 和 after application. As the vast majority of 水传播的 涂料 are anionic in nature ( (EU)中和), 本文将重点介绍胺中和树脂的类型, 虽然如果树脂极性, 比如酸的功能, 足够高, anionic resin types can be dispersible or even water soluble without the use of neutralizing 胺.

水性涂料技术主要有两大类: 水可约 (EU), 乳胶 (EU). 这篇文章的目的, 水可约 resins are normally made in solvent 和 then reduced with water to form a resin dispersion in water. 乳胶树脂是在水中乳液聚合而成的. The 油漆s using emulsion resins most often utilize a small amount of organic cosolvent to improve coalescence of the 乳胶 particles, 以及基材润湿.

其他 types of 水传播的 油漆s utilize a growing number of resin types that include PUD (聚氨酯分散体 (EU)以及微乳液. Accordingly, multiple issues can influence the 流, leveling, 和 appearance of 水传播的 涂料. 本文将主要考察树脂类型的影响, 2)湿度和温度变化, 3)润湿和4)流量控制. Appearance of the 涂层 during 和 after application can be affected greatly by these issues.

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