CN104568810A

CN104568810A - Chemical identification method of leather

Info

Publication number: CN104568810A
Application number: CN201310517499.9A
Authority: CN
Inventors: 李长娟
Original assignee: Individual
Current assignee: Individual
Priority date: 2013-10-29
Filing date: 2013-10-29
Publication date: 2015-04-29

Abstract

The invention relates a chemical identification method of leather. The chemical identification particularly comprises the following steps: (1) carrying out a combustion test, namely respectively shearing a small piece of real leather and a small piece of artificial leather sample, and lighting in a fume cupboard, wherein no flame and hard lump are generated in the combustion process of the real leather, and the smell of burnt protein is released; (2) carrying out a sodium hydroxide test, namely pouring 100mL of a 10%sodium hydroxide solution in mass fraction into a 250mL flask with a condenser, adding the small piece of the artificial leather sample, boiling for 30 minutes in the fume cupboard, after cooling, observing the sample in the solution, and determining that the sample is natural leather when the sample in the solution is not dispersed; (3) carrying out a infrared ray spectral analysis method; and (4) carrying out microscopic examination, namely judging the authenticity of the leather by virtue of a microscope. According to the chemical identification method of the leather, the authenticity of the leather can be identified, and the use is convenient.

Description

The chemical identification method of leather

Technical field

The present invention relates to the chemical identification method of leather, belong to leather technology field.

Background technology

More and more artificial leather product replacing leather comes into the market, and therefore usually needs to differentiate that certain product is natural leather or artificial substitute; Current, leather products is a feast for the eyes, and dragons and fishes jumbled together; In order to obtain the maximum benefit, manufacturer and dealer rack one's brains and push the sale of one's products, (certain polymkeric substance normally coated by leatheret to various artificial leather product, ironed non-woven fabric) eyes of human consumer openly and legally is entered with incomparable exquisite packaging, cheap price, the eyes of consumer are hoodwinked, the interests of consumer are encroached on, leather is natural protein product, brute force is high, water-permeable and air permeable Performance Ratio is better, the desirable fabric being used as leather wear, the best material of leather shoes, chaparajos; And the leatheret of artificial leather, although carried out various process true to nature, in dress, take in process there will be and torn, rupture, the problem of the grievous injury consumer's interests such as permeable, permeability is poor.

Traditional leather identifying method mainly contains 4 kinds: (1) sees whether product has the corium mark of State Administration for Industry and Commerce's registration; (2) whether observe, observing corium leather surface has more clear uniform pore; (3) touch, general leather is even, fine and closely woven and feel elasticity is better; (4) smell taste, every leather has the smell of leather, and leatheret all has the stronger plastics smell of pungency; Above several method is simple, convenient, but error is large, often can misguide the consumer, therefore, in order to improve the accuracy that leather is differentiated, the chemical identification method of recommendation leather.

Summary of the invention

The object of the present invention is to provide the chemical identification method of leather, be convenient to people and better identify leather.

To achieve these goals, technical scheme of the present invention is as follows:

The chemical identification method of leather, specifically comprises:

(1) combustion testing method: cut a small pieces leather and leatheret sample respectively, light in fuming cupboard; Without flame during leather burning, do not tie hard pimple in combustion, and discharge the smell of burning proteins; And give out pungent smell during leatheret burning, and easily form pimple; Combustion testing simple and fast, can be used for leather Preliminary Identification, then confirms with additive method;

(2) NaOH method of testing: leather is made up of collagen fabric, this pars fibrosa has been modified and has recombinated in process hides, do not have the collagen fabric of recombinating can be dissolved by sodium hydroxide solution when boiling, concrete method of operating is: in the flask of 250mL with condenser, the 100mL of falling people massfraction is the sodium hydroxide solution of 10%, add a small pieces sample (about 0.2g), in fuming cupboard, boil 30min; The sample in solution is observed after cooling, in solution, sample dispersion explanation is natural leather, because do not have the collagen fabric of recombinating to dissolve in the solution, and the fiber of those restructuring is insoluble, only leave some particulates, but leatheret can not be dissolved in containing nylon, poly-vinegar, polyacrylic ultra-microfibers the sodium hydroxide solution that massfraction is 10% usually under these conditions;

(3) infrared spectrum analysis method: infrared spectrum analysis is a kind of effective ways of qualification natural leather and leatheret, the energy of most of molecular vibration is consistent with the infrared region of electromagnetic wave spectrum, and the infrared spectrum that molecular vibration can be 4000cm-1 and 400cm-1 by wave number is usually discovered and measures; There is a vibration frequency in each functional group, there is the infrared spectral characteristic defined, infrared spectrum analysis is exactly the spectrum picking out functional group or compare known materials and measured material, spectrum for comparing meets the tendency and under equal conditions to obtain by identical technology, first strip off schedule of samples aspect is wanted, because most of leather makes rear surface wax, nitrocellulose, synthetic resin and other materials before analysis leather sample; The infrared spectrum of sample can be obtained by alkali halide particle compact technique or different reflection technology, sample powder is pressed into granule, get 3--10mg and be blended in (as sodium chloride) in the alkali halide powder of about 300mg equably, more commonly suppress the potassium bromide die of easily finding time and the pressing potassium bromide troche obtained by hydroelectric facility; First to determining the leather powder amount of compressed granulate to have the absorption spectrum that a unit is the strongest in the spectrum of gained, propagating by obtaining spectrum at the uniform leather powder-potassium bromide placing thin layer with infrared ray vertical direction;

Although from being difficult to the true and false distinguishing leather in appearance, but professional knows, leather is the molecular structure of native protein, containing such as shuttle base, Tai Anjiandeng functional group in structure, inherently there is the multi-form vibrational band of these functional groups in its FfIR spectrum; And the principal ingredient of leatheret is Polyvinylchloride, nylon, poly-vinegar and polypropylene etc., it is different that molecular structure and protein have in essence, the absorption of vibrations bands of a spectrum of shuttle base, phthalein amine key must be contained, so can conclude that tested sample is natural leather or leatheret from leather absorption band in MR spectrum simultaneously;

(4) microscopic examination: under microscope, the collagen fabric peeling the leather on top layer off is different from non-woven fabric in appearance, is also different from the homogeneous polymerization body of coating and the substitute of synthesis; So, the true and false of leather can be differentiated by microscopic examination; But along with improving constantly of process technology, some Performance Ratio leathers of fabricate-leather are good, some with nylon, poly-extremely can have similar transversal section under the microscope with the leatheret class substitute of polypropylene ultra-microfibers, therefore, simply can not think that the leather under microscope with transversal section similar to leather is exactly genuine.

This beneficial effect of the invention is: the authentication method of leather has a lot, and combustion testing, test chemical, infrared spectrum analysis and microscopic examination integrate the leatheret that just can identify natural leather or high emulation.

Embodiment

Below in conjunction with embodiment, the specific embodiment of the present invention is described, better to understand the present invention.

Embodiment

The chemical identification method of leather, specifically comprises:

(2) NaOH method of testing: leather is made up of collagen fabric, this pars fibrosa has been modified and has recombinated in process hides, does not have the collagen fabric of recombinating can be dissolved by sodium hydroxide solution when boiling; Concrete method of operating is: in the flask of 250mL with condenser, the 100mL of falling people massfraction is the sodium hydroxide solution of 10%, adds a small pieces sample (about 0.2g), in fuming cupboard, boils 30min; The sample in solution is observed after cooling, in solution, sample dispersion explanation is natural leather, because do not have the collagen fabric of recombinating to dissolve in the solution, and the fiber of those restructuring is insoluble, only leave some particulates, but leatheret can not be dissolved in containing nylon, poly-vinegar, polyacrylic ultra-microfibers the sodium hydroxide solution that massfraction is 10% usually under these conditions;

(4) microscopic examination: under microscope, the collagen fabric peeling the leather on top layer off is different from non-woven fabric in appearance, is also different from the homogeneous polymerization body of coating and the substitute of synthesis; So, the true and false of leather can be differentiated by microscopic examination.

The above is the preferred embodiment of the present invention; it should be pointed out that for those skilled in the art, under the premise without departing from the principles of the invention; can also make some improvements and modifications, these improvements and modifications are also considered as protection scope of the present invention.

Claims

1. the chemical identification method of leather, is characterized in that: specifically comprise:

(1) combustion testing method: cut a small pieces leather and leatheret sample respectively, light in fuming cupboard, without flame during leather burning, does not tie hard pimple in combustion, and discharges the smell of burning proteins; And give out pungent smell during leatheret burning, and easily form pimple; Combustion testing simple and fast, can be used for leather Preliminary Identification, then confirms with additive method;

(2) NaOH method of testing: pour the sodium hydroxide solution that 100mL massfraction is 10% in the flask of 250mL with condenser into, adds a small pieces sample (about 0.2g), in fuming cupboard, boils 30min; Observe the sample in solution after cooling, in solution, sample dispersion explanation is natural leather;

(3) infrared spectrum analysis method: sample powder is pressed into granule, get 3--10mg and be blended in (as sodium chloride) in the alkali halide powder of about 300mg equably, more commonly suppress the potassium bromide die of easily finding time and the pressing potassium bromide troche obtained by hydroelectric facility; First to determining the leather powder amount of compressed granulate to have the absorption spectrum that a unit is the strongest in the spectrum of gained, propagating by obtaining spectrum at the uniform leather powder-potassium bromide placing thin layer with infrared ray vertical direction;

(4) microscopic examination: under microscope, the collagen fabric peeling the leather on top layer off is different from non-woven fabric in appearance, is also different from the homogeneous polymerization body of coating and the substitute of synthesis, is observed the true and false differentiating leather by microscopes.