什么是示温涂料
示温涂料是指利用涂层颜色变化指示物体表面温度及温度分布的专用涂料, 在一定条件下, 示温涂料被加热到某一温度,会出现某一颜色变化,可用子确定此涂料的指示温度,示温涂料可用于飞机、电子元件、高温高压设备、高压电器、抽承套、非金属材料的温度测量,,示温涂料的主要优点有:
①尤其适合温度计无法测量或难于测量的场合;
②多变色示温涂料可示物体表面温度的分布情况;
③测温简单、快速、方便、经济,适合大面积温度测量;
④用不可逆示温涂料指示极限温度, 是简便的趙温报書和趙温记裁的方法。
示温涂科的分类
（1）按顔色能否可逆变化, 可分为可逆示温涂料和不可逆示温涂料, 可逆示温涂料是指涂料在加热至某一温度发生颜色变化, 但温度冷却后其颜色可恢复至原状态, 可多次反复使用, 不可逆示温涂料是指涂料在加热至某一温度发生长久性顔色变化,温度冷却后其颜色不会恢复至原状态,只能一次性使用,可用子记录物体曾达到的最高上限温度。
（2） 接频色可变化次数, 可分为単变色示温涂料和多变色示温涂料。 单变色示温涂料是指涂料在加热过程中仅发生一次颜色变化,可指示物体局部所达到的极限温度,仅含一种变色频料、変温范围可达40- 1350℃, 多变色示温涂料是指涂料在加热过程中会发生两次或两次以上颜色变化, 可指示物体表面的温度分布, 含有多种变色顔料, 变温范園可达55~1600℃, 可将几种不同热变色颜料或染料混合组成多色体系, 如由碳酸铅、品红、孔雀绿为频料的示温涂料,其温度变化,颜色也发生变化,见表1-67,
示温涂料的组成
示温除料由基料、变色频料、將剂、城料及其他添加剂组成。示a除料组成中重要的成分是变色顔料或变色染料。
（1）基料示温法料所选用的基料具有的着力强、耐温性好、频色浅,且不与顔料组分发生化学反应的性质。低温变色示温涂料的基料常选虫胶清深、気基树脂、原壓树脂、醇酸树脂、丙婦酸树脂、乙婦类树脂等。高温变色示温涂料的基料常选動屋树脂、有机建树脂、环a树脂等。一般来说,对同一基料用量大,变色温度就高。
(2) Color-changing pigments Color-changing pigments can be divided into organic and organic. Inorganic color-changing pigments have better temperature resistance and can be used for temperature-indicating materials above 30°C; organic color-changing pigments have poor temperature resistance and are generally used for temperature-indicating coatings below 300°C.
Color-changing pigments can also be divided into reversible color-changing pigments and irreversible color-frequency pigments. There are more types of irreversible color pigments than reversible color frequency materials. Common reversible color pigments include quick compounds, complexes or double salts of silver, copper and mercury (such as Ag2Hgl', CuHgI4, HgI2), compounds formed by town salt, shop salt and hexamethylenetetramine, Its discoloration process is a physical change, loss of crystal water or crystal transformation. Common irreversible color pigments include phosphates, complexes, nitrates, oxides, sulfides, phthalocyanine pigments, azo pigments, arylmethane pigments, etc. The discoloration process is a chemical change, which is caused by thermal decomposition or oxidation or chemical combination when heated.
The color change temperature and color change of several color change pigments are shown in Table 1-68.
③Filler
The pigments used in temperature-indicating paints are generally white powders with good thermal properties, such as zinc oxide, silicon dioxide, calcium oxide kaolin, talcum powder, etc. Some fillers will change the color-changing temperature of the color-changing pigment, increase or decrease, this is because some activating elements can catalyze or inhibit the color-changing pigment under the action of temperature.
(2) The discoloration principle of the temperature display coating
①The principle of color change of reversible temperature-indicating paint The color change of reversible temperature-indicating paint includes crystal form change, pH value change, crystal water gain and loss, tautomerism temperature, see Table 1-69
②Discoloration principle of irreversible temperature-indicating paint
