In-depth analysis of waterproof coating glue</p
There are many ways to classify waterproof coating glue. The main categories according to chemical structure are: </p
1. Polyacrylate (PA); </p
2. Polyurethane (PU);</p
3. Polyvinyl chloride (PVC);</p
4. Silicone;</p
5.合成橡胶类(如氯丁橡胶)。
</p
Compared with the solvent type, the water-based type is non-toxic, non-flammable, safe, low-cost and does not require recycling. It can produce thick-coated products, which is conducive to the production of colored coating products. The coating has good hydrophilicity; its disadvantage is low water pressure resistance. Slow drying and difficult to adhere to filament fabrics �按涂层工艺及焙烘条件不同又有干式涂层胶和湿式涂层胶，低温交联涂层胶和高温交联涂层胶之分� �此外，还有聚四氟乙烯、聚酰氨、聚酯、聚乙烯、聚丙烯和蛋白质类� �目前主要应用的是聚丙烯酸酯类和聚氨酯类� According to the medium used, it is divided into two types: solvent type and water type. The solvent type has the advantages of high water pressure resistance, good film-forming properties, fast drying, and low solid content, but at the same time it has permeability on fabrics. It has the disadvantages of being strong, feeling rough and hard, highly toxic, easy to catch fire, requiring solvent recovery equipment and high recycling costs. �干式和低温交联涂层胶因其涂层工艺简单，焙烘温度低，省力节能，它们是未来涂层织物发展的趋势� �</p
</p
1. Polyacrylate coating glue (Polyacrylate referred to as PA)</p
Polyacrylate fabric coating glue is one of the commonly used coating glues at present. It has the following advantages: </p
a. Good fastness to sunlight and weather, not easy to yellow; </p
b. Good transparency and co-compatibility, which is beneficial to the production of colored coating products; </p
c. Good washing resistance; </p
d. Strong adhesion; </p
e、成本较低。
The disadvantages are: </p
a. Poor elasticity and easy to wrinkle; </p
b. Poor surface finish; </p
c、手感难以调节适度。
初的聚丙烯酸酯类涂层胶属于单纯防水型产品，通过几十年的发展，目前的品种不仅具有防水透湿，阻燃等多种功能，而且还有低温节能的特色� �聚丙烯酸酯类涂层胶一般均由硬组分（如聚丙烯酸甲酯等）和软组分（如聚丙烯酸丁酯等）共聚而成� The main monomers of polyacrylate coating include acrylic acid, methyl acrylate, ethyl acrylate, butyl acrylate, etc. In order to improve its waterproof performance, acrylamide and acrylonitrile can be added when necessary. The polymerization initiator generally uses peroxide ( Such as potassium persulfate, etc.) �</p
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1.1 Waterproof coating finishing agent</p
此种聚丙烯酸酯类涂层整理剂初多为溶剂型产品，其粘着性和耐水性极佳。为了提高膜的强度，常加入外胶联剂。其适合加工柔软的薄织物，与拼用一次，即可获得较高的拒水和耐水压效果。但溶剂型产品含有大量的有机溶剂如甲苯、醋酸乙酯等，使用时容易造成环境污染或发生火灾，且溶剂回收费用高。溶剂型涂层整理剂合成方法主要有两种，一种是悬浮聚合，所得产品的分子量较高；另一种是溶液聚合，所得产品的分子量低。
为了克服溶剂型产品的缺点，水系型的聚丙烯酸酯类涂层整理剂应运而生� �水系型的又分为乳液类，非皂乳液类和水溶类三种� �乳液类分子量为10-500万，粒子直径0.05-0.2微米，含固量一般为40-60%� Due to the emulsion polymerization method, a small amount of compound emulsifier is added during polymerization. Due to the presence of the emulsifier, during the process of fusing and forming a film, part of it is squeezed to the interface between the film and the fabric, thus weakening the bonding strength with the fabric, making the The water pressure resistance of the product is affected to a certain extent �水溶类是一种特殊的胶体分散液，是在高聚物中引入亲水性官能团，能在水中呈澄清状态，水溶类的分子量一般在10-20万左右� �另一部分被挤至膜的外表面，引起膜表面的涩滞感，造成涂层织物的手感不爽� �非皂乳液类（也有称无乳剂型）涂层剂不含乳化剂，对织物主要进行精细涂层防水整理� �整理后的织物能保持原有的风格，具有柔软的手感和很高的牢度，手感滑爽，有较高的机械性能和良好的防水效果� �</p
It has been reported in China that polyacrylate ultrafine emulsion was synthesized by emulsion polymerization. Its average particle size is below 50nm and its appearance is translucent colloidal mucus. 2D resin was selected as the external linking agent and fluorine-containing resin was used for post-water-repellent finishing. Allows coated fabrics to achieve higher water pressure resistance and water repellency �目前国内该类产品多为外交联型，应用时须加入交联剂，给厂家应用带来不便� �近年国内有人对水性超微乳自交联聚丙烯酸酯织物涂层剂的应用性能进行了研究，结果表明其性能优异，具有广阔的应用前景� �</p
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1.2 Waterproof and breathable coating finishing agent</p
经此类涂层剂整理过The fabric has both waterproof and moisture-permeable functions. Its waterproof and moisture-permeable mechanism relies on the formation of a large number of micropores during film formation. These pores are smaller than 2 microns, which can block water droplets (average diameter 100 microns), but allow water vapor molecules (average diameter 0.0004 microns) to pass through, thereby achieving waterproof and breathable properties. In order to improve the breathability and moisture permeability of polyacrylate processed fabrics, since the 1980s, Japan has dissolved acrylate copolymers containing hydrophilic groups such as carboxyl, hydroxyl, and nitrile groups in water-miscible organic solvents. The coating glue is made from the coating glue. After coating, it is treated with warm water to remove the solvent and solidify the copolymer. It is dried and dehydrated to form a microporous film on the fabric. This kind of coating adhesive uses wet coating to treat fabrics with good breathability and moisture permeability. Compared with dry coating, wet coating is more complicated, so it is imperative to develop fabric coating adhesives that are both dry coating and waterproof and breathable. Our country developed such products such as PP-3 in the mid-1980s, which are made of acrylic monomer emulsion polymerization.
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1.3 Multifunctional coating finishing agent</p
目前，聚丙烯酸酯涂层胶已从过去的防水透湿型产品发展到多个品种，主要包括阻燃，防风，遮阳及泡沫涂层整理剂，甚至还兼有几种性能的多功能产品。其中又以阻燃涂层胶发展快。研制开发阻燃涂层剂主要有两种途径，一种是选用阻燃性单体共聚；另一种是在聚丙烯酸酯乳液中添加阻燃协效剂和阻燃剂。
</p
2. Polyurethane coating glue (Polyurethane referred to as PU)</p
The full name of polyurethane is polyurethane. It is a polymer compound containing -NHCOO- unit in its molecular structure. This unit is formed by the reaction of isocyanate group and hydroxyl group. The reaction formula is as follows: </p
—N=C=O+HOˉ→—NH-COOˉ</p
20世纪70年代，德国首先合成了PU。在1950年前后，PU作为纺织整理剂在欧洲出现，但大多为溶剂型产品用于干式涂层整理。20世纪60年代，由于人们环保意识的增强和政府环保法规的出台，水系PU涂层应运而生。70年代以后，水系PU涂层迅速发展，PU涂层织物已广泛应用。80年代以来，PU的研究和应用技术出现了突破性进展。与国外相比，国内关于PU纺织品整理剂的研究较晚。
Polyurethane coating agent is the main type of development today. Its advantages are: </p
a. The coating is soft and elastic; </p
b. The coating has good strength and can be used for very thin coatings; </p
c. The coating is porous and has moisture permeability and ventilation properties; </p
d、耐磨，耐湿，耐干洗。
Its shortcomings are: </p
a. The cost is higher; </p
b. Poor weather resistance; </p
c、遇水、热、碱要水解。
PU涂层剂按组成分类有：聚酯系聚氨酯；聚醚系聚氨酯；芳香族异氰酸酯系聚氨酯；脂肪族异氰酸酯系聚氨酯。按使用上采用的介质分为溶剂类和水系类。
</p
2.1 Solvent-based PU coating glue</p
溶剂类PU具有良好的强伸度和耐水性，但毒性大，易燃烧。从组分上来说，它还分为双组分类和单组分类。双组分产品由预聚物和交联剂组成，预聚物是将异氰酸酯与低聚多元醇反应生成的末端为羟基的预聚物。交联剂则是含有多个（三个以上）异氰酸酯基的化合物。在涂层整理时，预聚物与交联剂反应，形成热固性网状薄膜，赋予纺织品优良的性能。为了达到防水透湿的效果，溶剂型涂层整理剂一般采用湿法涂层工艺加工织物。
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2.2 Water-based PU coating glue</p
水系型又分为水溶性和水分散型两种。水系PU用于织物涂层整理，量大面广。水系PU成膜性好，并有较好的防水性。
水系PU涂层胶初采用转相乳化法制造，但产品中含有乳化剂，对粘着性、强韧性和耐水性产生不良影响。为了解决这个问题，20世纪80年代后期，自乳化型水系涂层胶逐渐增多，其主要原理是在聚合物链上引入适量的亲水基团，在一定条件下自发分散形成乳液。水系PU涂层胶通常用于干法涂层。为提高涂层产品的耐水性、柔软性和耐久性，应进行前、后防水整理。
PU大分子中含有大量的极性基团，分子间力很强，导致其具有优良成膜性，能够在织物上形成坚韧而耐久的薄膜，拒水性良好，它还具有一定透湿性� The reason is: on the one hand, the polar groups or hydrophilic groups in PU, such as -OH, -NHCOO-, -SO3H, -COOH, etc., act as “chemical step stones” to cause water vapor molecules to flow from high to high along the steps. The humidity side migrates to the low humidity side; on the other hand, PU is composed of soft segments and hard segments, forming amorphous regions and crystallized regions in the structure respectively. Since the molecular chains in the amorphous region are relatively loose and the structure is not tight, water moleculesIt is easy to enter, migrate and spread, thereby achieving the purpose of moisture permeability.
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2.3PU emulsion modification</p
为了提高乳液及膜性能，扩大应用范围，需要对PU乳液进行适当的改性。目前，改性的途径大致可分为四类：⑴改进单体和合成工艺；⑵添加助剂；⑶实施交联；⑷优化复合[10]。其中尤以复合乳液的研究为活跃。
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3. Silicone (polysiloxane) coating glue</p
20世纪70年代，有机硅类涂层整理剂开始发展。
聚硅氧烷类化合物的主链由硅氧键连接而成，而硅原子上又接有烷基，苯基等构成的侧链，故其具有半无机半有机的高分子结构。构成聚硅氧烷主链的Si—O—Si链的键角较大，原子与原子之间的距离较长，具有较大的自由度。此外，Si—O键长达0.193nm，这样使得聚二甲基硅氧烷类为代表的聚硅氧烷类化合物不易发生结晶化。因此，其容易透过氧气，氮气甚至水蒸气分子，用其处理后的织物具有良好的通气透湿性。
In recent years, there has also been research on polysiloxane coating agents in China. Polysiloxane coating agents and polyurethane coating agents are mixed in a certain proportion and then coated on fabrics to achieve satisfactory waterproofing. Moisture permeability effect �其作用机理是：防水性取决于涂层连续厚膜和聚硅氧烷的拒水作用� �而透湿性能则依赖于聚硅氧烷良好的透气性和聚氨酯分子中亲水基团的“化学阶梯石”作用，通过吸附－扩散－解吸方式进行传湿� �</p
有机硅类涂层整理剂主要由具有活性基团的聚硅氧烷弹性体组成，在金属盐或有机酸盐的作用下可以进行交联反应� �采用不同的聚硅氧烷弹性体和不同的催化剂能使涂层纺织品具有不同的性能和风格� Mixing silicone elastomers with other coating polymers can improve the feel, breathability and wear resistance of other coating glues. Mixing silicone elastomers with other coating glues is the development direction of coating processing. , many scientific and technological workers focus on research in this field �</p
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