PRINTING PASTE, METHOD FOR PRINTING TEXTILE PRODUCTS USING THE PASTE, AND TEXTILE PRODUCTS OBTAINED THEREBY

Abstract: A printing paste in the form of a uniformly kneaded mixture comprising, in parts by weight each 100 parts of egg yolk, 1-10 parts of a preservative, 1-10 parts of a lower alcohol, 20-40 parts of an alkyd paint and 5-30 parts of a water-soluble resin clear paint. The printing method com­ prises the steps of printing a design on the surface of a textile product at room temperature under ambient pressure, fixing the paste on the textile product by drying the tex­ tile product, removing the residual paste from the textile product by washing with water, and drying the product. The printed textile product has improved fastness withstan­ ding repeated washings.

Description: The present invention relates to a printing paste, a method for printing designs on textile product surfaces and products obtained thereby. More particularly, it relates to a technique for printing designs using a paste added with egg yolk as an adhesive or glue for improved color fastness to washing. Washable products such as bed linens used in hotels and hospitals are printed with designs such as a name, logo or mark. To print such designs, a printing paste containing a dye, additive(s) and an adhesive paste is directly applied on the textile, which in turn is subsequently subjected to steaming or dry heating for coloring and fixing. Most of the adhesive pastes contained in the printing paste act as a medium for promoting transfer of the dye and the additive(s) to the textile and are removed by washing with water after the printed design is fixed on the textile. According to the conventional printing of textiles, the dye is chemically adhered on the textile so that after repeated washing for more than ten times, the printed design would disadvantageously fade or disappear. An object of the present invention is to obviate the above problems and to provide a printing paste and a method for printing a design in characters and graphics on textiles that will not fade or disappear but withstand repeated washing. Another object of the present invention is to provide textile products printed with designs by this invention method. In order to achieve the above objects, the printing paste according to the present invention is a uniformly kneaded mixture comprising 100 parts by weight of egg yolk, 1 - 10 parts by weight of a preservative, 1-10 parts by weight of a lower alcohol, 20-40 parts by weight of an alkyd paint, and 5-30 parts by weight of a water-soluble resin clear paint. The printing method according to the present invention comprises the steps of applying said printing paste in the form of an aimed design on the surface of a textile product at a room temperature and ambient pressure, drying said textile product to fix said printed paste, washing the textile product with water to remove the residual paste and drying the textile. The egg yolk to be used in the present invention may be the egg yolk of any bird, including those with the longer diameter of 30 cm or bigger and smaller ones with the diameter of ca. 1 cm. Because of the low price and availability in terms of quantity, chicken eggs are preferable. Freshly laid eggs are shelled and separated into the yolk and the white. This separation is preferably conducted on the industrial scale using a known apparatus or tool. Because there is little risk of foaming even if the egg yolk is mixed, the following three methods are recommended for preparing the printing paste. According to the first method, the egg yolk is thoroughly agitated into a pasty state at room temperature under ambient pressure using a commercial blender. The pasty egg yolk is thoroughly blended with a preservative and a lower alcohol at room temperature under ambient pressure to obtain a stock solution. The stock solution is further kneaded with an alkyd paint and a water soluble resin clear paint at a room temperature under ambient pressure. The second method comprises the steps of adding the pasty egg yolk obtained as per the first method to a mixture of the preservative and the lower alcohol, thoroughly agitating the mixture at room temperature under ambient pressure to obtain a stock solution, adding the alkyd paint and clear paint, and kneading the mixture at room temperature under ambient pressure. The third method comprises the steps of blending the preservative and the lower alcohol simultaneously with the egg yolk immediately after separation from the egg white, thoroughly agitating the mixture at room temperature under ambient pressure to obtain a stock solution, and blending the alkyd paint and clear paint with the stock solution and kneading at room temperature under ambient pressure. One or more preservatives to be used in the present invention are selected from food preservatives such as sorbic acid, ortho-phenylphenol, sodium benzoate, salt, sugar, salicylic acid, dehydroacetic acid, and parahydroxybenzoic ester. Particularly, sorbic acid, ortho-phenylphenol, sodium benzoate, salt and sugar are preferable for their low price and availability. Methyl alcohol or ethyl alcohol is preferable as the lower alcohol for its high affinity to egg yolk and to preservatives as well as for its disinfectant property. The ratio of the preservative and lower alcohol to be blended in the stock solution is 1-10 parts by weight for preservative and 1-10 parts by weight for lower alcohols as against 100 parts by weight of egg yolk. When the amount of preservative is less than 1 part by weight, the egg yolk will easily become putrid, whereas if it exceeds 10 parts by weight, the adhesive property of the egg yolk decreases.When the amount of lower alcohol is less than 1 part by weight, it becomes difficult to uniformly mix the preservative with the egg yolk. On the other hand, if the amount exceeds 10 parts by weight, the resultant stock solution becomes insufficient in viscosity, making it difficult to adequately handle the printing paste as the paste dries too quickly during the printing process. Alkyd paints suitable for the present invention comprise as binder an alkyd resin which is usually an oil-modified and/or fatty acid-modified condensation polymer of two-basic acids and polyols, which alkyd resin is dissolved in organic solvents. The alkyd paint contains pigments in the range from 8 parts by weight to 30 parts of weight. The water-soluble resin clear paint contains as binder a water-soluble and water-miscible, respectively resin dissolved in water. Preferred resins are polymers containing acrylic or methacrylic acid, the carboxyl groups of which nay be neutralized. Paints containing such resins are known as water-soluble acrylic resin clear paints and varnishes, respectively. Both the alkyd paint and the water-soluble resin clear paint are based on air-drying resins. The ratio of the alkyd paint and the clear paint to be blended in the stock solution is respectively 20-40 parts by weight of the alkyd paint and 5-30 parts by weight of the clear paint as against 100 parts by weight of the egg yolk. Addition of the alkyd paint in an amount less than 20 parts by weight results in insufficient coloring while its addition exceeding 40 parts by weight will deteriorate adhesion of the printing paste on the textile product. When the amount of the clear paint is less than 5 parts by weight, the printing paste cannot be applied smoothly on the surface of a textile product, whereas if the amount exceeds 30 parts by weight, the paste will blur. The printing paste according to the present invention is applicable to any of the hand printing techniques such as using brush, stencil, and screen or to the machine printing such as using roller, flat screen and rotary screen. The amount of alcohol and clear paint to be blended into the printing paste differs depending on the printing technique. For hand printing, the amount of alcohol is increased and the amount of clear paint is decreased for the increment. For machine printing, the amount of clear paint is increased and the amount of alcohol decreased accordingly. Using any of the printing techniques mentioned above, a desired design in characters or graphics is printed on the textile surface at room temperature under ambient pressure. Textile products to be used in the present invention may include fabrics made of cotton, linen, wool and synthetic fibers; blended, united or knitted fabrics; clothings, beddings and fabric apparel accessories made of these fabrics. These textile products are made of such fabrics or according to such sewing specifications that they would not lose the shape or the body despite washing with water. Textile products printed with the paste are subjected to spontaneous drying at room temperature under ambient pressure or to hot air drying to fix the paste along with the pigment on the products. Dried textile products are washed with water below 40°C to completely remove the residual paste, removed of washing water, and dried spontaneously or with hot air. The textile products are pressed with iron to suit the intended use. The textile printed with the printing paste of the invention will demonstrate a highly improved color fastness to washing and withstand repeated washings or more than hundred times with water without discoloring. The printing paste of present invention is particularly suitable for printing patterns on bedding linens such as sheets, blanket coverlets, and uniforms used in hotels and hospitals where frequency washing is unavoidable. The present invention will now be described in more detail by way of examples. Example 1 Five hundred grams of egg yolk separated freshly from the white are agitated at 20°C under ambient pressure into a pasty state using a large size blender for home use. The pasty egg yolk is added with 10 g of powder preservative (SPP by Ueno Pharmaceuticals) containing sorbic acid and ortho-phenylphenol as the main components and 10 g of ethyl alcohol for disinfection. The mixture is further agitated thoroughly in the blender at 20°C under ambient pressure to obtain a uniformly mixed stock solution. The stock solution thus obtained is added with 150g of an alkyd paint with red pigment of 10 weight % (for use on iron by Asahi Pen Corporation) and 60g of a water soluble acrylic resin clear paint, throughly agitated at 20°C under ambient pressure in the blender to obtain a uniformly mixed printing paste. Using a paint brush, 50 sheets of bed linen for hotel use were hand printed with a name. The hand printed bed linens were dried spontaneously at 20°C under ambient pressure and washed with water to remove the residual paste. After removing the washing water and drying, the bed linens printed with name in vivid red color without blurring were obtained. Example 2 One kilogram of egg yolk freshly separated from the white was thoroughly agitated at 20°C under ambient pressure into a pasty state using a blender for confectioners (by Fujii Kaki Co.). The pasty egg yolk is transferred into a vessel, added with 20 g of sodium benzoate and 30 g of methyl alcohol, and thoroughly agitated at 20°C under ambient pressure in said blender to prepare a uniformly mixed stock solution. The stock solution was added with 330g of an alkyd paint with yellow pigment of 12 weight% (for use on iron by Asahi Pen Corporation) and 200 g of a water-soluble acrylic resin clear paint, and thoroughly agitated at 20°C under ambient pressure to obtain a uniformly mixed printing paste. Using the paste and the rotary screen printing technique, 100 sheets of hotel bed linen were printed with a name. The printed bed linens were dried spontaneously at 20°C under ambient pressure and washed with water to remove excess paste. After drying, the bed linens printed with the name in vivid yellow color without blurring were obtained. The bed linens obtained in Examples 1 and 2 were subjected to washing for 120 times using a rotary drum washing machine with water at 40°C added with 0.1 parts by weight of a synthetic detergent as against 100 parts by weight of water. The printed names in red and yellow showed no discoloration but maintained the vividness at the time of printing. Printed portions of the bed linens obtained in Examples 1 and 2 were cut out to be used as test pieces for washing test according to JIS L 0844 A-2. The results are shown in table 1, which indicates that the textile products printed in accordance with the present invention are excellent in color fastness to washing. Change in color Staining Cotton Wool Example 1 Class 5 Class 5 Class 5 Example 2 Class 5 Class 5 Class 5 Judgement on change in color and staining is classified into 5 classes, Class 5 being the highest.

Claims: A printing paste comprising, in parts by weight each, 100 parts of egg yolk, 1-10 parts of a preservative, 1-10 parts of a lower alcohol, 20-40 parts of an alkyd paint and 5-30 parts of a water-soluble resin clear paint as a uniformly kneaded mixture. The printing paste of claim 1, wherein the pigment content of said alkyd paint is from 8 to 30 weight %. The printing paste of claim 1 or 2, wherein the resin in said water-soluble clear paint is an acrylic resin. The use of a printing paste of any of claims 1-3 for printing designs on textile products. The use of claim 4 comprising the steps of printing a design on the textile surface with a printing paste as defined in any of claims 1 to 3 at room temperature under ambient pressure, drying the textile, removing the residual paste from the textile by washing with water, and drying the textile product.

Inventors: YAMATE, MASATO
Applicants: YAMATE, MASATO
Application year: 1989
Main classification: D06P1
IPC codes: D06P1, D06P5