RU2202667C2 - Method of manufacturing vinyl polymer-based imitation leather - Google Patents

Abstract

FIELD: polymer materials. SUBSTANCE: invention relates to finishing of imitation leather in order to impart to it handling ability and hygienic properties owing to increased air-permeability of imitated leather, which can be applied as finishing film for vehicle interior parts and as noise-suppressing materials in special-destination premises. Method consists in that foaming composition including polyvinylchloride resin, plasticizers, stabilizers, softener, poreformer, dispersant, and pigmented filler is applied on knitted warp and then the total is covered by film based on polyvinylchloride resin, plasticizers, stabilizers, softener, and pigmented fillers, after which three-layered material is subjected to heat treatment, printing, and perforation. EFFECT: increased strength, hygienic properties, and forming capability. 2 cl, 1 tbl

Description

 The invention relates to the decoration of artificial leather with the aim of imparting technological and hygienic properties to it by increasing air permeability and can find application as a finishing layer for interior parts of passenger cars, trucks and other vehicles, as well as a sound-absorbing layer in special rooms.

 A known method of producing artificial leather, according to which a foaming composition based on a polyvinyl chloride resin, plasticizers, stabilizers, a softener, a pore former with a dispersant and a filler is applied to a fibrous substrate (base), followed by heat treatment in a two- or three-zone chamber. This method is selected for the prototype [Copyright certificate 701187, 06/19/1995].

 The disadvantages of artificial leather obtained using the prototype method are, firstly, low strength characteristics and aesthetic qualities due to the lack of a strong and dense monolithic layer. Secondly, the technological capabilities are not high enough, which makes it difficult to use it to cover surfaces of complex shape. Thirdly, the protozoa is not hygienic enough, since it almost does not allow ventilation due to the absence of any significant ventilation ducts. This sharply narrows the scope, in particular, eliminates its use as a facing layer for parts of complex configuration, for example, for automobile doors made by molding from a heated wood-filled polymer sheet.

 The problem to which the invention is directed is to eliminate these drawbacks, namely, to obtain strong, flexible, hygienic artificial leather, with a high shaping ability, in order to maximize customer satisfaction.

 The problem is solved in that in a method for producing artificial leather, comprising applying to the base a foaming composition based on polyvinyl chloride resin, plasticizers, stabilizers, a softener, a pore former, a dispersant and a filler with pigments followed by their heat treatment, in contrast to the prototype, a second composition is additionally prepared for based on polyvinyl chloride resin, plasticizers, stabilizers, emollients, fillers with pigments, from which a second film is made, which before thermo processing is applied to the surface of the first film, previously applied to the base, which is used as a knitted fabric, after which the obtained three-layer material is subjected to heat treatment, embossing and perforation.

 The components of the formulation can be selected by any of those traditionally used for this purpose, for example, suspended polyvinyl chloride of the brand S-79-58M, S-70-59M.

 The following components can be used as plasticizers: diethylhexyl phthalate (DOP), dialkyl phthalate (DAP-789), diethyl heskyl sebacetate (DOS), diethyl hexyl adipate (DOA).

 As stabilizers - a complex complex stabilizer Ba-Cd stearic acid (SCS K-17), diphenylol propane tech., Epoxidized vegetable oils, stabilizer BAZ-49.

 As a softener - stear acid. tech.

 As a blowing agent - porphore CHKhZ -21.

 As a dispersant, calcium alkylbenzenesulfonate (ABSK).

 As a filler - chemical precipitated chalk, Aerosil 300.

 As pigments - at the request of the customer, for example, color 619 (gray) - titanium dioxide, carbon black K 354, heliogen blue; color 99 (black) - soot K-354.

Example
The inventive method is as follows. A PVC composition is being prepared for the first (porous) layer. The composition of the first (porous) layer may be such, parts by weight:
Polyvinyl chloride suspended C 70-58 M - 100
Plasticizers
DOF - 70
DOS - 20
Stabilizers
SKS-17 - 1.5
Diphenylolpropane tech. - 0.4
Epoxidized Vegetable Oil - 1.9
Softener
Stearic acid tech. - 0.3
Blowing agent
Porofor ChHZ-21 - 2.0
Dispersant
Alkylbenzenesulfonate (ABSK) - 1.1
Filler
Aerosil A-300 - 0.5
Pigments - 2.68
The Henschel mixer, preheated to 100-125 ^o C, is loaded with polyvinyl chloride, plasticizers, stabilizers and other components of the formulation mentioned above, except for pigment paste. After processing in the Henschel mixer, the resulting mixture is fed through a nozzle to a pre-heated intensive mixer, and pigment paste is also loaded through the nozzle there. During mixing, a partial plasticization of the mixture occurs. The discharged mixture in the form of a lumpy rubber-like mixture enters the rollers, where there is a uniform distribution of all components over the volume of the mixture, its heating and plasticization. The mixed and heated plastic compound in the form of a strip with a width of 40-79 mm is continuously fed through the conveyor to the calender.

In parallel, the preparation of adhesive paste is being applied, which is applied to the base. The base is a cotton viscose or cotton siblar knitted fabric with a nominal surface density of 135-150 g / m ² , 150-160 g / m ² . Preparation of adhesive paste for coating the base. 1/3 of the plasticizer is automatically poured into the pre-cleaned vertical mixer, emulsion polyvinyl chloride and all other components according to the recipe are loaded, except for the polyvinyl chloride chlorinated resin PSX-LS. The mixture in a thick batch is mixed for 35 minutes. The temperature of the mixture is 30-33 ^o C. Then the chlorinated polyvinyl chloride resin, previously mixed with a plasticizer in a ratio of 1: 5, the remainder of the plasticizer is fed into the mixer. The mixture is stirred for 30-40 minutes. The temperature of the unloaded mixture is 30 ^o C. The finished mixture is piped to the three-roll paint sprayer, where it is rubbed once. Paint roller rollers should be cooled. The viscosity of the finished adhesive paste is 10 seconds along the Svetlov bucket with a hole diameter of 16 mm. Next, the adhesive paste is applied to the base. The knitted fabric (base) from the unwinding device is fed through a tray compensator to the roller squeegee, where adhesive paste with a thickness of 20 ± 5 g / m ² is uniformly applied to it. After applying the adhesive paste, the knitted fabric enters the heat chamber, where the surface is dried at a temperature of 150-220 ^o C.

Calendering of the mixture for the first porous layer, applying it to the base is as follows. The base treated with the adhesive paste from the heat chamber enters the preheated four-roll L-shaped calender between the rubberized clamping shaft and the fourth calender shaft. At the same time, a mixed and heated plastic compound for the first porous layer, which is calendared and applied to the substrate, enters the gap between the first and second shafts from the heating-nutrient rollers. It turns out a semi-finished product. After that, the calendering of the second composition for the monolithic layer is carried out and its application to the semi-finished product. The composition of the second layer is the following, parts by weight:
Polyvinyl chloride suspended C 70-58 M - 100
Plasticizers
DOF - 50
DOS - 20
Stabilizers
SKS-17 - 1.7
Diphenylolpropane tech. - 0.4
Epoxidized Vegetable Oil - 2.0
Softener
Stearic acid tech. - 0.3
Filler
Chemical precipitated chalk - 17.32
Pigments - 2.68
The semi-finished product from the first calender enters the second calender, calendaring the mixture for the second (monolithic) film takes place there - the mixture for it enters from the heating-nutrient rollers into the gap between the first and second shafts. The connection of the semi-finished product and the monolithic film occurs between the fourth and lining shaft of the second calender. The resulting semi-finished product is cooled. As a result of this operation, a thin web with a shiny, inexpressive surface is obtained. For further decoration, the web is fed to the operations of pore formation, heat treatment and embossing. Before being fed into the heat chamber, the semi-finished product from the unwinding device passes through the compensator, is fixed with needle clips (screw clamps) in the span frame and sent to the heat chamber with three heating zones. In the first zone, gelling occurs with slight pore formation. In the second zone, the temperature is higher, providing complete pore formation in the first layer. In the third zone, the final gelling of the entire surface improves the quality of the coating and increases the bond strength with the substrate. When leaving the heat chamber, the material passes through a cooling device, where it is blown with cold air to fix the porous structure. Before the embossing shaft, the surface of the material is heated by an infrared heater and embossed. After passing through the cooling drums, the edge of the vinyl leather on a knitted basis is trimmed with special knives. Further, the material goes to finishing operations (printing, finishing). A printed drawing is applied to the front surface of the material in order to improve its appearance. Printing is as follows. The semi-finished product from the unwinding device is fed through a compensator to a printing unit consisting of a bath, a rubberized roller and a printed metal shaft with a pattern applied to its surface. Printing ink is applied to the bath, which is applied to the surface of the vinyl leather through a printing roller. Then the material enters the heat chamber, then through cooling drums it is fed to the winding device and further processing - applying a finishing solution. The purpose of applying the finishing solution is to obtain vinyl artificial leather with a matte or a certain gloss (depending on the requirements of the consumer) and non-sticky surface. Finishing solution is applied to the surface of the material using a roller squeegee. Drying of the finishing layer is carried out in a heat chamber, and then the material is cooled, passing through cooling drums. After these operations, the canvas has a matte embossed surface, its thickness increases, it becomes softer and more elastic, it becomes similar to the skin. Finished material is wound on a roll. The resulting artificial leather in appearance and physico-mechanical properties satisfies many customers. However, its technological and hygienic properties, namely the absence of pronounced ventilation channels, narrows the scope of its application. The resulting vinyl leather "does not breathe" and, therefore, does not have sufficient form-forming properties. It is difficult to use as cladding stamped parts of the passenger compartment. Indeed, when connected to the surface to be coated, air bubbles form between them, which impair fit due to the absence of channels for the exit of this air. For the same reason, the resulting vinyl leather is not suitable for upholstering the seats and backs of vehicles, i.e. those surfaces that come in contact with the human body and therefore require ventilation. To meet customer requirements, the resulting vinyl leather is subjected to perforation. Perforation is as follows. The material from the unwinding unit through the guide roller evenly, without jerking, is unwound using a pulling pair of rolls, then passes through a compensation roller. Further, the material is pulled through a guide roller under a perforating comb, where it is perforated. The temperature of the needle shaft 145-155 ^o C. the Number of needles 48 pieces per cm ² . The form of perforations is round, diameter is 1.0-1.2 mm, perforation geometry is 5 • 10 mm. Perforation speed 2 m / min. Die cuts after perforation are collected in a collector mounted under a perforation comb. After that, the material enters the inspection box, where the quality of perforation is visually determined. The quality of the perforation is determined by viewing the finished distortion in the lumen, as well as laboratory tests.

 Physico-mechanical characteristics of the obtained vinyl artificial leather are given in the table.

 The inventive method allows due to the introduction of an additional operation - perforation (or microperforation) to ensure the satisfaction of hygienic and technological requirements for artificial skin. Indeed, due to the perforations, a perfect fit of a flat piece of perforated artificial leather to any surface of complex configuration is achieved. The holes in this case are not only channels for passing air, but also a kind of "curvature compensators." This allows you to use this skin for the manufacture of stamped parts for the interior of the car and for other similar purposes.

Claims (1)

 A method for producing vinyl leather, including applying a foamable composition based on a polyvinyl chloride resin, plasticizers, stabilizers, a softener, a blowing agent, a dispersant and a filler with pigments to a base, followed by heat treatment, characterized in that they also prepare a second composition based on a polyvinyl chloride resin, plasticizers, softener fillers with pigments from which the second film is made, which is applied to the surface of the first film before heat treatment previously applied to the base, which is used as a knitted fabric, after which the resulting three-layer material is subjected to heat treatment, embossing and perforation.

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