High-solids automotive coatings

Manufacturers of automotive repair finishes are tending to reduce more and more the level of volatile organic compounds in their paints in order to comply with increasingly strict environmental legislation. After a review of the main parameters allowing a viscosity reduction in acrylic resins in general, this paper describes the use of a reactive intermediate called CARDURA E10 (a trade mark of the Royal Dutch group of companies) which is able to reduce the solution viscosity of different resins and, hence, allows to increase the solids content of automotive paints while improving the final coating properties.     

自干丙烯酸金属闪光汽车漆的研制

介绍了丙烯酸金属闪光漆的配方及技术指标，讨论了树脂，金属闪光粉，助剂和稀释剂等主要影响因素。     

Polymerization and application of 2-methacryloyloxyethyl phenyl phosphate in coatings

2-Methacryloyloxyethyl phenyl phosphate (MEPP) was synthesized by reacting 2-hydroxyethyl methacrylate (2-HEMA) with phenyl dichlorophosphate (PDCP) followed by hydrolysis. This acrylic monomer containing the phosphate group was introduced into a typical UV-curable acrylated epoxy system as an adhesion promoter. Good adhesion properties and solvent resistance of the films after UV curing were obtained in the presence of MEPP, although there was a decrease in the curing rate. When MEPP was introduced into acrylated epoxy resin, the contact angle remarkably decreased indicating that the wetting ability was improved. When MEPP was applied to the synthesis of the water-soluble acrylic resins cured with various water-soluble epoxy resins at 25°C, the adhesion and corrosion resistance of coating films was improved.     

Synthesis and application of a novel epoxy grafted thermosetting acrylic resin

A novel manufacturing process for high performance metallic can coating was carried out based on an epoxy‐grafted acrylic resin. Firstly, the epoxy resin was reacted with acrylic amide forming a ring opened product epoxy‐amide resin, and then the product obtained copolymerized with all other monomers, such as acrylic acid (AA), butyl acrylate (BA), hydroxypropyl acrylate (HPA), 2‐ethylhexyl acrylate (2‐EHA), methyl methacrylate (MMA), styrene (St), using free radical solvent polymerization in the presence of BPO. The resins prepared present the transparent appearance, and the target resin coating based on these resins exhibits excellent boiling resistance and chemicals resistance and can be applied as the protective coating for metallic can. The effects on the coating properties, such as amount of acrylic acid, 2‐EHA wt % between 2‐EHA and BA, amount of amino resin, amount of catalyst, and so forth, were investigated. In addition, the influences of polymerization time on the conversion ratio of monomers were also studied. Results show that under the optimal conditions, the target resin coating provides excellent physical and mechanical properties. The various properties tests for this coating have been performed in accordance with the standards of ASTM. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

紫外光固化EA树脂的研制

环氧树脂和丙烯酸在适宜条件下合成EA树脂。讨论了各种反应条件对EA树脂性能的影响。确定了最佳工艺条件 :催化剂A用量 1% ,阻聚剂B用量 1‰～ 3‰ ,在 10 0℃滴加丙烯酸 1 0h～ 1.5h ,滴加完后在 110℃反应约 0 5h ,丙烯酸与环氧树脂的摩尔比为 1 0 4∶1。     

Resin transfer molding with powder-coated preforms

Incomplete fiber wetting in a resin transfer molded composite may result in poor surface finish, high void content, and reduced mechanical properties. This work studied the use of tows that are precoated with a powdered version of the liquid molding resin (towpregs). The goal is to see if such preforms improve the final part properties because of better fiber wetting. Hercules 12K AS-4 fibers and PR500 (liquid) and PS500 (Powder) resins (3M) were used to make fabrics from towpregs containing 50 wt% total resin (liquid and powder combined). The powder fractions were 0, 13, 21, 50 wt%. Samples were resin transfer molded from preforms made from the towpreg fabrics. Results showed that samples molded with powder-coated preforms had improved surface finishes and reduced void contents (1.4 vs. 5%), but that the mechanical properties were not improved (transverse moduli of ∼ 7.8 Gpa and axial moduli of ∼ 100 Gpa), probably because of defects inherent in the hand-woven towpreg fabric that was used.     

The rheological properties of an aqueous acrylic dispersion suitable for automotive waterborne basecoats

Superior film appearance as well as performance is required of automotive top-coatings applied using the method of two-coat one-bake (2C1B) in the case of metallic finishes. The basecoats, however, dominate the final film appearance, that is, the metallic effect and the film surface smoothness. Waterborne metallic basecoats are rather difficult to maintain a high level of workability and appearance under various spraying conditions involving a wider range of temperature and humidity. Both the aluminum flake orientation and the surface smoothness of basecoats, which involve opposite requirements especially in a waterborne system, should be superior before clearcoats are over-coated. In this paper, we will present a means of incorporating them. The studied model basecoats are composed of three materials, a specific water-dispersible acrylic resin, an internally crosslinked latex and a melamineformaldehyde resin. The viscosity versus non-volatile content relationship and the viscoelastic behavior of the model paints are discussed, in relation to the actual spraying workability and the final appearance.     

Modulation of Adhesion at Acrylic Adhesive-Silicone Elastomer Interfaces

We have recently reported a systematic investigation of the role of MQ resins (small silica-like nanoparticles) in the modulation of adhesion at silicone elastomer lens—nanometric thin acrylic surface anchored layer deposited on a silicon wafer through loading and unloading JKR experiments. This particular system was chosen as it allowed one to vary the MQ resin content in the elastomer, and to test its resulting effect on both the thermodynamic work of adhesion and the adhesive strength at elastomer—acrylic layer interfaces, avoiding any complication due to bulk mechanical properties of a relatively thick (in the micron range) acrylic layer. We present here a complementary investigation, aimed at understanding the role of the resins in the development of specific interactions at the interface. To do so the adhesive energy between silicone elastomers containing various amounts of MQ resins and model substrates made of self-assemble monolayers of thiol molecules with various amounts of carboxylic terminations have been measured through JKR tests. We show that the level adhesion at these interfaces results from a competition between increased interactions and decreased mobility associated with the incorporation of the resins inside the elastomer.     

Stabilization of aluminium pigments in water-borne systems by paint resins

Conclusions  Certain paint resins were able to inhibit the evolution of hydrogen of aluminium pigments in aqueous media at pH 10; especially drying alkyd resins showed excellent results. By contrast the two oil-free saturated polyesters examined were only very poor corrosion inhibitors at pH 10. At a pH value of 8 all polyesters, alkyd resins, epoxy esters, phenolic resins, polyurethane and acrylic resins showed an almost complete inhibition of hydrogen evolution; the two polyesters were again (relatively) worst corrosion inhibitors at pH 8. It can be supposed that the correct choice of paint resins may lead to the formulation of non-gassing water-borne metallic paints with unstabilized aluminium pigments.     

油罐车用丙烯酸金属闪光底色漆的制备

通过选择合适的丙烯酸树脂、助剂、醋酸纤维素、铝银浆等,再配以合适的固化剂,制备了一种施工便利,在湿碰湿工艺下做罩光清漆不重溶的油罐车用金属闪光底色漆。     

Flame-retardant Finishing of Textiles

The need for flame-retardant finishing of textiles is examined in the context of the hazards of textile flammability, associated legislation and procedures for assessing textile burning behaviour. The functions of flame-retardant finishes and durable finishes developed specifically for cellulose, wool and man-made fibres are described in depth. Multipurpose finishes for both cellulose and wool textiles in which flame retardancy is only one property conferred on the textile are examined. Fibre blends present a particular problem and special attention is paid to discussing those finishes applied to polyester/cotton blended fabrics. The laundering behaviour and consequent finish durability are reviewed. In addition, the effects that applying flame-retardant finishes have on textile properties and performance are considered. Recent developments in methods used to apply flame-retardant finishes are outlined.     

Urethane/acrylic composite polymer emulsions

Blends of waterborne urethane and acrylic polymer systems were studied to obtain a composite emulsion that would have all of the advantages of the two polymers without their associated disadvantages. An approach to achieve extensive polymer-polymer interactions through crosslinking reactions was studied to optimize the positive aspects of each polymer. The crosslink system used an acrylic polymer emulsion containing keto or aldo groups and a polyurethane dispersion incorporating a hydrazine group. The degree of crosslinking was determined by FT-IR Single package, ambient temperature crosslinking emulsions were obtained by using this system. In addition to the excellent properties these two polymers normally possess, the crosslinked blends exhibit synergistic effects in film properties, such as good solvent resistance and low heat sensitivity over a wide range. Composite polymers of this type could be useful in applications where high durability is required: tennis court coatings, floor coatings, laminating adhesives. and paper and textile finishes.     

Elastomers Formed In-Situ in Epoxy Resins: Chemistry and Toughening

The chemistry of the in-situ formation of elastomer particles in epoxy resins is described. Under normal synthetic conditions, if one polymerizes an acrylic monomer in an epoxy resin, the resulting polymer is soluble in the epoxy resin or it grossly phase separates, depending upon the solubility parameter difference between the acrylic polymer and the epoxy resin. This work shows that with the use of a specifically tailored material (which we believe operates as a “polymeric surfactant”) in the reaction mixture, a free-flowing, stable suspension of acrylic elastomer particles in epoxy resin can be obtained. Thus, the reaction product of isocyanatoethylmethacrylate and EPON^TM 1009 can be used as the polymeric surfactant in a reaction mixture containing hexyl acrylate, azo-bis(isobutyronitrile) and the diglycidyl ether of bisphenol A. The resulting dispersion is stable to settling even after exposure to 150°C. When properly formulated, the resulting modified epoxy resins are improved in their fracture resistance after cure over a similar resin without the elastomeric particles. The effect of the following parameters on the fracture resistance of the cured epoxy resin are discussed: chemistry of the polymeric surfactant, chain extension in the cure of the epoxy resin, type of acrylic monomer and the level of the elastomer. The physical properties of several adhesive formulations based upon these modified epoxy resins are also discussed.     

溶剂型丙烯酸树脂的研究进展

本文介绍了溶剂型丙烯酸树脂的发展情况及其特点,详细论述了溶剂型丙烯酸树脂的品种发展现状。另外对该产品的研究动向展开了系统的讨论,如高固体份丙烯酸树脂、SAC系列以及有机硅改性丙烯酸树脂等,并阐述了基团转移聚合方法和纳米技术对溶剂型丙烯酸树脂性能的影响。简要介绍了各类溶剂型丙烯酸树脂的在涂料工业中的应用,并对后期低污染高性能产品的开发作了展望。     

高性能丙烯酸聚氨酯摩托车面漆的研制

介绍了高性能丙烯酸聚氨酯摩托车面漆的研制过程，讨论了树脂、颜料、光稳定剂、润湿分散剂对涂料性能的影响。     

水性树脂复配与成膜助剂选择对单组份水性木器漆性能的影响

介绍了一种高硬度单组份自交联水性木器漆的制备,通过水性聚氨酯分散体和水性丙烯酸乳液进行复配,选择合理复配比例,并讨论了成膜助剂对涂料综合漆膜性能的影响。结果表明：水性聚氨酯分散体E与丙烯酸乳液A按质量比1：1复配,漆膜各性能达到最佳。通过FTIR分析可知,两种树脂发生的自交联反应,两者之间存在氢键的作用。选用二丙二醇甲醚（DPM）与二丙二醇丁醚（DPnB）为成膜助剂,按质量比1：1复配,漆膜硬度较高,表面效果好,其他性能也显著提高。     

Reaction during cure of a blocked isocyanate–epoxy resin adhesive

Model compound reactions of isocyanate sources with alcohols and an epoxy resin indicated that the major reaction product from the phenol-blocked methylenebisphenylene diisocyanate and epoxy resin-based adhesive dip for poly(ethylene terephthalate) cord was a polyurethane. A significant portion of the hydroxyl groups required for the reaction were formed by ring opening of the epoxide groups of the resin. The reaction rate for the unblocking of the isocyanate source was inhibited in the presence of polyester yarn finishes containing sulfated esters of fatty acids. Also, compounds containing carboxylic acid groups and sulfonic acid groups inhibited the unblocking step. Amines and their salts catalyzed the unblocking step. A mechanism for the polyurethane adhesive–polyester bond based upon physical interaction is postulated. The presence of certain nonsulfated ester finishes permitted good wetting of the polyester surface and penetration of the adhesive into the polyester. By contrast, sulfated ester finishes result in poor wetting and penetration by the adhesive on the polyester. By contrast, sulfated ester finishes result in poor wetting and penetration by the adhesive on the polyester. The latter finishes resulted in a weak boundary layer between the adhesive and the cord.     

油剂对涤纶POY条干不匀率的影响

从油剂的角度探讨了影响涤纶 POY条干不匀率的因素 ,着重从油剂的特性和使用性能等方面作了分析。结果表明 :性能优良的油剂、适宜的集束上油位置和正确的使用方法可有效降低 POY条干不匀率。在配制油剂时 ,应选用合适的平滑剂和润湿剂 ,使乳液稳定 ,谨防乳液霉变     

高固体分低粘度羟基丙烯酸树脂的制备

采用单体、引发剂溶液同步连续滴加工艺,通过对引发剂用量及聚合反应温度的调控,有效地降低体系粘度并控制体系中羟基的分布,成功地制备了固含量达70%以上的高固含量低粘度羟基丙烯酸树脂.对引发荆用量、聚合反应温度、溶剂及链转移剂的选择等进行了研究,在降低体系粘度的同时能有效地控制分子量及羟基的分布.     

Acrylic-fluoropolymer mixtures and their use in coatings

Fluoropolymer coatings, particularly those based on polyvinylidene fluoride (PVDF) resins, have a 35 year history of outstanding performance in outdoor applications. However, the chemical inertness of PVDF presents challenges to the paint formulator in that it prevents adhesion to substrates and makes it difficult to disperse pigments. To overcome these difficulties, an acrylic modifier resin is usually added to the PVDF resin. The acrylic modifier is traditionally physically blended with the PVDF resin to improve coating adhesion and enhance pigment dispersion. The physical blending results in a PVDF/acrylic mixture on a macro-molecular scale. ATOFINA Chemicals, Inc. has developed a novel approach to mix the fluoropolymer and acrylic on micro-molecular scale. Because of this intimate mixing, and the wide latitude of the acrylic and fluoropolymer monomers that can be utilized, a wide range of unique properties can be achieved in solvent-base dispersion coatings, and water-borne coatings. The unique properties of the solvent-base and water-borne coatings are discussed in this paper.