| Currently, the implementation of pigment printing technology is an effective way for printing and dyeing industry to achieve cleaner production, energy-saving and emission reduction because of its many advantages, such as simple process, complete color chromatography, easy color matching and not washing after fixation. However, as a key component of the printing paste, the binder not only exists APEO residue, formaldehyde releasing and other environmental problems, but also there are contradiction between handle and color fastness of printed fabric, which hinder the improvement of quality seriously. In view of the above, a soft and environmental friendly pigment printing binder was exploited by developing emulsification system, constructing crosslinked system, and synthesising organosilicon modified acrylate latex in this paper. There are four parts in this research.Part one: The application of non-APEO polymerizable compound emulsifier in the preparation of pigment printing binder.In this part, The non-APEO traditional compound emulsifier was confected by anionic emulsifier A-6280, non-ionic emulsifier A-980, and on this basis polymerizable compound emulsifier was prepared after introducing polymerizable emulsifier APS-100, which were used to synthesis pigment printing binder by semi-continuous pre-emulsifying emulsion polymerization. The influences of emulsifier and its amount on polymerization stability, latex stability, latex particle, dissolve-loss rate and mechanical properties of latex film and color fastness of pigment printing were studied. It was found that the bonding action of polymerizable emulsifier to the latex particle surface can ameliorate the electrolyte resistance, pH stability and freeze-thaw stability of latex, reduce the dissolve-loss rate of latex film, improve the mechanical properties of latex film and color fastness of pigment printing fabric. Especially at the amount of polymerizable compound emulsifier of 6%, the emulsion polymerization exhibited higher monomer conversion and lower polymerization coagulation rate, the latex had good electrolyte resistance, pH stability and freeze-thaw stability, the latex particles had regular morphology and its diameter was about 80nm, the latex film presented lower dissolve-loss rate, higher fracture work, and the pigment printing fabric had excellent color fastness.Part two: The construction of formaldehyde-free crosslinking system for polyacrylate pigment printing binder.In this part, lipophilicity crosslinkers glycidyl methacrylate (GMA), ethylene glycol dimethyl acrylate (EGDMA) and hydrophilicity crosslinker HA (containing hydroxyl, acrylamide group), N-methylol acrylamide (NMA) were used to synthesize pigment printing latex by semi-continuous pre-emulsifying emulsion polymerization. The influences of crosslinker type on latex particle size, viscosity and film-forming speed of latex, crosslinking degree and mechanical properties of latex film were studied. Then, the effect of compound crosslinkers ratio and its amount on latex film, pigment printing were investigated. It was found that the latex particle size, viscosity and film-forming speed of latex were related to the hydrophilicity and lipophilicity of crosslinkers. The latex synthesized with hydrophilicity crosslinkers always presented big particle size, slow film-forming speed, great viscosity and pseudoplastic fluid characteristics. The crosslinking degree and mechanical properties of latex film generally depended on the crosslinked groups of crosslinker and its reaction activity. The compound crosslinker was confected by GMA and HA at the weight ratio of 1:4, which can give excellent mechanical properties of latex film and superior crackfastness of pigment pringting when its amount was 4% at weight of comonomer.Part three: Study on preparation and properties of silicone-acrylate copolymer latex for pigment printing.In this part, acrylate, acrylic acid, vinylsilane coupling agents and octamethylcyclotetra- siloxane were used to synthesis silicone-acrylate copolymer binder for pigment printing. The influencing factors on properties of binder latex and monomer conversion were investigated, and the structure and properties of product were studied, such as Tg, heat resistance, particle morphology, particle size and its distribution, tensile property and water resistance of film. It was found that the silicone-acrylate copolymer binder with high monomer conversion can be obtained in the condition as follows: when the weight ratio of soft monomer BA to 2-EHA was 4:1, the weight ratio of hard monomer St to MMA was 3:1, the weight ratio of soft to hard monomer was 2.5:1; the amount of acrylic acid was 3% weight of acrylate monomer; the weight ratio of organosilicon modified monomer vinyl triethoxy silane(VTES) to D4 was 1:4, and its amount was 10% weight of acrylate monomer; the amount of catalyst DBSA was 7% weight of D4; reaction temperature was 80-85℃; reaction time was 1h. The particle presented regular ball shape and its diameter was about 100nm.After the modification of organosilicon, the Tg of polyacrylate decreased, the heat resistance improved and the tensile strength of latex film reduced, the fracture elongation increased, and the water resistance became better.Part four: Study on application of silicone-acrylate copolymer binder (SAC) for pigment printingThe influences of silicone-acrylate copolymer binder amount, curing temperature and curing time on properties of pigment priting fabric were studied. And it was compared with other pigment printing binder. It was found that when the binder was 20%, curing temperature was 150℃, curing time was 3min, the fabric printed with 5% amount of pigment had good handle, grade 4 of dry rubbing fastness and grade 3-4 of wet rubbing fastness can be obtained. Compared with other pigment printing binder, the fabric of printed with bider SAC had better handle.The results showed that polymerizable compound emulsifier can be taken as an excellent non-APEO emulsifier at the emulsion polymerization of pigment printing binder, which was composed of emulsifier A-6280,A-980 and APS-100 by mass ratio 2:1:1.The compound crosslinker can be taken as an excellent formaldehyde-free crosslinker at the emulsion polymerization of pigment printing binder, which was composed of GMA and HA by mass ratio 1:4. The silicone-acrylate copolymer binder for pigment printing had excellent color fastness and handle, which was synthesizd by acrylate, acrylic acid, VTES and D4.
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