CN109295265A

CN109295265A - Deashing method

Info

Publication number: CN109295265A
Application number: CN201810736109.XA
Authority: CN
Inventors: 贺丽蓉
Original assignee: Stahl International BV
Current assignee: Stahl International BV
Priority date: 2017-07-06
Filing date: 2018-07-06
Publication date: 2019-02-01
Also published as: EP3425069B1; EP3425069A1

Abstract

The invention discloses deashing methods, it includes deliming steps: using the deliming agent without ammonium and boric acid by the fur deliming of liming, the deliming agent includes protolysate, the protolysate is prepared according to method comprising the following steps: (A) hydrolyzes hair, shavings, lop and/or feather to generate amino acid and/or amino-acid salt, then obtains protolysate.The present invention is using the waste material from leather manufacture as the raw material of deashing method, realize recycling, and the concept of " closed loop " technique is significantly enhanced, and realize friendly, mild deashing method, the clean fur surface of scytoblastema and the feel of softness can be obtained.

Description

Deashing method

Technical field

The present invention relates to deashing methods.

Background technique

It is well known that the pretreatment of original fur should be completed before process hides in leather making processes.Liming is Usually one of hair and the pretreatment of unwanted albumen are removed by the way that fur to be immersed in lime bath.In leather manufacture Preparatory process (beamhouse process) accounts for 80% of debirs in effluent and sludge.Wherein, about 70% liming is come from Process.It typically, there are two kinds of liming technologies, i.e. hair burning and hair saves.Hair Techniques of preserving by attack hair root from Hair is removed in skin and keeps hair shaft complete, this allows to be easily separated hair from effluent by simply filtering. Compared with hair combustion technology, hair saves same economy, and has ecological benefits；Therefore, in local government to effluent It is dominant liming technology when discharge there are certain requirements.However, the hair of liming usually has staple fiber, and strong Alkaline chemical pollution, the application which has limited it in textile and carpet manufacturing industry.

A kind of technological approaches of hair treatment is to extract valuable protein, such as keratin and keratin debris, and will They are used as surfactant or functional additive in personal-care supplies.Another method is separated from hair-hydrolyzation object Single valuable amino acid is for pharmacy and fine chemistry industry industry.These approach technically allow the high added value benefit of hair With.However, needing additional investment, and the water during purification step to the high request of the technical controlling of hydrolytic process and purifying A large amount of consumption (1 ton of pure amino acid consumes about 200 tons of water) of resource inhibit the utilization of the hair of liming.Most of hair It is poured on the vacant lot around tannery, stink and environmental problem is caused due to long-time storage.Past one and half In century, leather industry is seeking always the economy that product is recycled from the hair of liming and ecological method.

After liming, deliming is needed so that the pH value of fur reaches basicity state appropriate.Deliming refers to from including it Calcium hydroxide is removed in the fur of surface and interior section and the pH value of fur is reduced to about 8.During deliming, if hair The pH value reduction of skin is too fast, then excessive deliming occurs and leads to surface acid-swellable.Texture damage and acid-swellable in order to prevent, Ying Tong Crossing to apply has comfort cushioning ability and is enough to remove the mild deliming of satisfactory deliming agent progress of lime.

Routine deliming agent used in leather industry is based primarily upon ammonium salt, such as ammonium sulfate, ammonium chloride.May 4 nineteen forty-three The US 2,318,454 of authorization uses ammonium salt as deliming component.Following due to having the characteristics that, ammonium salt is wide in leather industry General receiving: 1) raw material cheap compared with organic compound；2) buffer function provides narrow pH range in deliming floating material And it prevents the damaged surfaces of fur and mildly removes lime from the fur of liming.Ammonium salt is considered good in deliming formula Good buffer generates the leather with clean surface, even with the leather of dyeing property and excellent handle.

When ammonium salt is used for deliming purpose, they and calcium hydroxide reaction and are chemically combined at calcium hydroxide physical bond On the fur of liming.For example, reacting between ammonium sulfate or ammonium chloride and calcium hydroxide is as follows:

Ca(OH)₂+NH₄Cl→CaCl₂+NH₃+H₂O

Ca(OH)₂+(NH₄)₂SO₄→CaSO₄+NH₃+H₂O

There are two disadvantages for deliming agent tool based on ammonium, and which has limited its applications in the industry.The disadvantage are as follows: 1) deliming The ammonia discharged in the process leads to worker's exposure in an unsafe environment；2) the high NH in process hides effluent₃N content makes must It must carry out NH₃- N removal, which increase the cost of wastewater treatment and duration.

The high NH due to caused by ammonium salt₃- N pollution, has explored three classes compound as deliming in document and patent Agent: 1) inorganic acid, such as boric acid；2) small molecular organic acid, including lactic acid, citric acid, succinic acid or adipic acid；3) macromolecular, such as Polyimides, polysuccinimide and hydroxyl polysuccinimide.

Boric acid has very good buffer function in deliming floating material, and is used as selective deliming agent, energy Enough leathers across the uniform deliming of thick fur and generation with good quality.However, boric acid have genotoxicity, and according to REACH (registration, assessment, authorization and limitation ((Registration, evaluation, the authorization and of chemicals Restriction of chemicals))), boric acid is listed in SVHC (substance (the substance of very of highest attention High concern)) in.Lack the buffer system that there is smaller influence on workers ' health and environment at present.

CN 102010917A refers to a kind of deliming agent without ammonia, it is the combination of two kinds of organic acids.A kind of organic acid It is small molecular organic acid, such as citric acid or succinic acid；Another organic acid is gluconic acid or sulfosalicylic acid.However, above-mentioned make Small molecular organic acid has very limited buffer function in the fur of liming.

WO 2013/107233A also discloses a kind of deliming agent without ammonia.The deliming agent include polysuccinimide or Hydroxyl polysuccinimide.Polyimides, polysuccinimide are polymer, in the fur for slowly penetrating thick liming.

Since using ammonium salt, many tests have had been carried out to seek safety, sufficient and mild deliming agent.So And for many years, it is still necessary to develop the environmental-friendly deliming agent having with ammonium salt comparable deliming ability and high permeability.

In leather making processes, another waste, the i.e. shavings and lop of pollution of chromium are produced.It these shavingss and repairs Cut object accounts for solid waste in leather industry 60%.Considerably less chromium content limits the further application of collagen waste, Lead to the high cost of Solid Waste Treatment in tannery.Leather industry be badly in need of for pollution of chromium shavings and lop it is more economical Method.

Up to the present, de- there are no discarded hair, shavings and lop can either be applied in leather manufacture industry With realization " closed loop " processing in grey method, and it can be realized and the mild of ammonium salt and boric acid may be not present with good deliming effect take off The solution of grey method.

Summary of the invention

Disclose the deashing method of leather manufacture.The deashing method includes deliming steps: with not ammonium salt-containing and boric acid Deliming agent makes the fur deliming of liming, and the deliming agent includes protolysate, and the protolysate is according to including following steps Rapid method preparation: (A) hydrolyzes hair, shavings, lop and/or feather to generate amino acid and/or amino-acid salt, then obtains Obtain protolysate.

The deliming agent has high lime solubility value and good buffer capacity during deliming, and ensures to be originated from leaching The NH of grey agent₃Zero addition of-N load, leads to NH low in deliming effluent₃- N load.According to the present invention, in effluent most Whole NH₃- N value is about 100ppm.

The active component of protolysate is amino acid and/or amino-acid salt.It is passed through with the deliming of amino acid or amino-acid salt Implemented by following approach:

After reacting with hydroxide ion, the amine groups of protonation generate amine compounds, are weak base and mention for system For buffer capacity.Good buffer capacity allows pH value to be gradually reduced and prevent the acid-swellable on texture layer.

When reacting with calcium ion, carboxyl forms soluble calcium salt, and can effectively remove lime and generate has clean surface Wet blue/wet-white leather (wet blue/wet white).

Protolysate of the invention can be individually used in deliming agent or combine with some additives to be used in deliming agent, And good deliming effect is realized in the case where no ammonium salt helps, this makes it possible to substitute conventional boric acid and ammonium salt.

Compared in deashing method based on the deliming agent of ammonium salt, deashing method of the invention is more environmentally friendly.The present invention Deliming agent have the feature that 1) protolysate is used as deliming agent；They are all safe chemical combination to environment and worker Object；2) amino acid in protolysate will not be by NH₃- N load is introduced into deliming effluent, therefore deashing method may be implemented The NH of middle generation₃The reduction of-N；3) compared with known without the deliming agent of ammonium, deliming agent of the invention have almost with ammonium salt Equivalent good deliming effect, and acid-swellable will not be caused；4) deliming agent can come from leather making processes by hydrolysis The hair of liming or the shavings of pollution of chromium or lop obtain.It reduce the costs of deliming agent, solve the hair of liming The waste problem of hair, shavings and lop, and prevent by the solid waste based on keratin and collagen of processing pollution Caused by environmental pollution.

Specific embodiment

Therefore, the purpose of the present invention is to provide deashing methods comprising deliming steps: with the deliming agent for being free of ammonium and boric acid By the fur deliming of liming, the deliming agent includes protolysate, and the protolysate is according to the side included the following steps Method preparation: (A) hydrolyzes hair, shavings, lop and/or feather to generate amino acid and/or amino-acid salt, then described in acquisition Protolysate.

In step (A), hair refers to the animal hair and/or human hair of all kinds, as long as the hair includes Keratin.Feather in step (A) refers to the plumage of all kinds, as long as the feather includes keratin.

In step (A), shavings or lop are the solid waste from leather making processes.Shavings in step (A) Or lop refers to the hair or leather shavings or lop of all kinds, as long as the shavings or lop include collagen ?.

In step (A), hydrolysis can be carried out via conventional proteolysis method, as long as amino acid can pass through hydrolysis Generation.Method for hydrolysis can be sour water solution, basic hydrolysis and/or enzyme hydrolysis, preferred acid hydrolysis.

In preferred embodiments, the sour water solution include the following steps: (a-1) at 80-130 DEG C, it is molten in inorganic acid Hair, shavings, lop and/or feather are hydrolyzed in liquid I, (a-2) removes insoluble matter by filters pressing, and (a-3) is used without ammonium Filtrate is neutralized to pH value and is 4-7 and obtains protolysate solution by alkali compounds, and optionally (a-4) is spray-dried egg White hydrolyzate solution simultaneously obtains protolysate.

Protolysate used in deliming agent can be the form of the protolysate solution obtained in step (a-3) with And the form of the desiccation protein hydrolysate obtained in step (a-4).

In step (a-1), the inorganic acid in inorganic acid solution I is the acid of general inorganic used in leather making processes, Preferably comprise at least one selected from the following: hydrochloric acid, sulfuric acid, nitric acid and phosphoric acid.The content of inorganic acid can be in inorganic acid solution I It is selected according to conventional methods, preferably 5-40wt%.In step (a-1), hydrolysis time can according to conventional methods into Row selection, preferably 1-10 hours.In step (a-3), pH value is preferably 5-6.5.

When the hydrolysis hair in the step (a-1), the total weight based on inorganic acid solution I and hair, the amount of hair is preferred For 10-50wt%, more preferably 20-50wt%, most preferably 30-50wt%.The content of inorganic acid is preferred in inorganic acid solution I For 10-38wt%.The hydrolysis of hair preferably carries out at 80-130 DEG C.The time for hydrolyzing hair is preferably 2-8 hours.

When the hydrolysis shavings in step (a-1) and/or lop, based on the total of inorganic acid solution I, shavings and lop The amount of weight, shavings and lop is preferably 40-80wt%, more preferably 50-75wt%.Inorganic acid in inorganic acid solution I Content is preferably 10-40wt%.The hydrolysis of shavings and/or lop preferably carries out at 80-130 DEG C.It hydrolyzes shavings and/or repairs The time for cutting object is preferably 2-7 hours.

In step (a-3), alkali compounds is conventional alkaline compound used in leather making processes, is preferably comprised At least one selected from the following: sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, sodium bicarbonate and saleratus.

In preferred embodiments, when the hydrolysis hair in step (A), hair can be the hair of liming.It is preferred that The hair of liming is pre-processed before hydrolysis.The pretreatment of the hair of liming can be carried out according to conventional methods to remove and deoil Rouge, dirt and the chemical substance of pollution, the pretreatment preferably include following steps: (i) washs liming with inorganic acid solution II Hair, it is 5-8 that (ii), which neutralizes inorganic acid solution II to pH value, and (iii) removes effluent, dry simultaneously to obtain preprocessed Hair.

In step (i), the content of inorganic acid is preferably 0.3-2mol/L in inorganic acid solution II.Inorganic acid solution II's Amount is preferably 3-20 times, more preferably 3-10 times of the weight of the hair of liming.Inorganic acid in inorganic acid solution II is leather The acid of general inorganic used in manufacturing process, preferably comprises at least one selected from the following: hydrochloric acid, sulfuric acid, nitric acid and phosphoric acid.It washes The time washed is preferably 1-5 hours.Washing preferably carries out under stiring.

In step (ii), alkali can be used for neutralizing inorganic acid solution II, and alkali can be used in leather making processes Conventional alkali, preferably comprises at least one selected from the following: sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, sodium bicarbonate and Saleratus.The amount of alkali can the conventional method according to used in leather making processes selected, pH value is adjusted to 5- 8。

In step (iii), drying is preferably carried out at 30-60 DEG C.

In preferred embodiments, when the hydrolysis shavings in step (A) and/or lop, shavings and/or lop can To be shavings and/or lop containing chromium.It is preferred that before hydrolysis to containing chromium shavings and/or lop pre-process.It is right The pretreatment of shavings and/or lop containing chromium can be carried out according to conventional methods except crude removal, the preferred packet of pretreatment Include following steps: shavings and/or lop containing chromium is washed with water in (iv), removes crude removal, is immersed in calcium oxide, glucose and water Solution in；(v) remove water, (vi) with inorganic acid solution III carries out acid take off chromium so that chromium from shavings and lop dissociation, and (vii) sufficiently washing is with except dechromising and obtain pretreated shavings and/or lop.

In step (iv), the amount of water is preferably 3-20 times of the weight of shavings and lop containing chromium, more preferably 3- 10 times.The time of washing is preferably 1-5 hours.Washing preferably carries out under stiring.

In step (iv), immersion is the fibre structure opened in the shavings containing chromium and/or lop.Weight based on water It measures, the content of calcium oxide is preferably 1-3wt% in solution.Weight based on water, the content of glucose in solutions are preferably 0.1- 0.3wt%.Soaking time is preferably 2-4 days.

In step (vi), the content of inorganic acid is preferably 4-15wt% in inorganic acid solution III.Inorganic acid solution III In inorganic acid be general inorganic used in leather making processes acid, preferably comprise at least one selected from the following: hydrochloric acid, sulphur Acid, nitric acid and phosphoric acid.Dissociation of the time of the de- chromium of acid depending on chromium, preferably 0.5-2 hours.

In preferred embodiments, deliming agent can also include organic acid and/or carbon dioxide, and organic acid herein does not wrap Include amino acid.The organic acid considered in the present invention is common organic acid in leather making processes.Preferably, organic acid includes At least one selected from the following: lactic acid, citric acid, adipic acid, malonic acid, succinic acid, glutaric acid and gluconic acid；More preferably amber Amber acid and/or adipic acid.Better deliming efficiency may be implemented in the combination of protolysate and organic acid.

In preferred embodiments, deliming agent can also include additive.Consider that for additive of the invention be leather Any conventional additives used in manufacturing process.Preferred additive is y oxidant and/or catalyst.Preferred additive Include at least one selected from the following: manganese sulfate, manganese chloride, manganese acetate, sodium formate, potassium formate, sodium hydrogensulfite, pyrosulfurous acid Sodium, potassium metabisulfite, sodium acetate, potassium acetate, sodium sulphate, potassium sulfate, sodium bisulfate, potassium acid sulfate, SODIUM PERCARBONATE and percarbonic acid Potassium.

In preferred embodiments, deliming agent preferably also includes amino acid composition.Amino acid composition means any component, only It will be it includes amino acid and/or amino acid ion and can be with Ca (OH)₂Reaction is without generating any negative shadow to deliming It rings.Amino acid, amino-acid salt are preferably comprised for amino acid composition of the invention and/or contain amino acid and/or amino-acid salt Other protolysates.In the present invention, other oroteins hydrolysate is meant according to step (A) none obtained proteolysis Object.

It is commonly known amino acid for amino acid of the invention, containing amine and carboxyl functional group, and to every kind The special side chain of amino acid (R yl).Amino acid with good buffer capacity and lime solvability is preferred for the present invention In.Preferably, amino acid is a-amino acid, has the amine and carboxyl functional group connecting with alpha -carbon atom.In majority of case Under, the general formula of a-amino acid is H₂NCH(R)COOH。

In preferred embodiments, a-amino acid include at least one selected from the following: glycine, alanine, valine, Leucine, isoleucine, phenylalanine, tryptophan, tyrosine, histidine, serine, threonine, cysteine, asparagus fern ammonia Acid, glutamic acid, asparagine, glutamine, lysine, arginine, proline, methionine and selenocysteine.It is based on Experiment, discovery glycine, serine, asparagine, leucine, glutamine and/or lysine are preferred.

It can be natural or synthesis amino acid for amino acid of the invention.All stereoisomers of amino acid are equal It can be used in the present invention, such as D-, L- or D, l-amino acid.

It is preferably water soluble amino hydrochlorate for amino-acid salt of the invention.It will not be with the common ammonia of calcium ion coprecipitation Base hydrochlorate can be used in the present invention.Amino-acid salt is preferably alkali metal salt and/or hydrochloride.Alkali metal be preferably sodium and/or Potassium.

Other protolysates are preferably collagen hydrolysate and/or keratin hydrolyzate.Degree of hydrolysis is in the present invention It is unrestricted, as long as there are amino acid or its salt in other protolysates.It is hydrolyzed into the amino acid levels of high-content It is preferred.

Protolysate and amino acid in deliming agent are calculated according to the content of amino acid and amino-acid salt total in deliming agent The total content of component.For protolysate, the amino acid and amino-acid salt in protolysate are for calculating total amino acid With the content of amino-acid salt.The content of total amino acid and amino-acid salt in deliming agent can be according to normal in leather manufacture industry Rule method is selected.Particularly advantageously, the content of amino acid total in deliming agent and amino-acid salt is preferably 40- 100wt%, more preferably 55-100wt%, further preferably 70-100wt%, most preferably 80-100wt%, wt% are bases In the total weight of amino acid, amino-acid salt, organic acid and additive.

The content of organic acid can be selected according to the conventional method in leather making processes in deliming agent, preferably 40wt% or lower；More preferably 5-20wt%；Most preferably 5-10wt%, wt% are based on amino acid, amino-acid salt, organic The total weight of acid and additive.

In deliming agent the content of additive can the conventional method according to used in leather making processes selected, preferably It is based on the total of amino acid, amino-acid salt, organic acid and additive for 25wt% or lower, more preferably 1-10wt%, wt% Poidometer.

In preferred embodiments, it is 55-94wt% that deliming agent, which includes the content of wherein total amino acid and amino-acid salt, Protolysate, the organic acid of 5-20wt% and the additive of 1-25wt%, wt% are all based on amino acid, amino The total weight of hydrochlorate, organic acid and additive.Preferred protolysate, preferred organic acid and preferred additive To be selected separately or together according to preferred solution above.

In a more preferred embodiment, it is 80- that deliming agent, which includes the content of wherein total amino acid and amino-acid salt, The protolysate of 90wt%, the organic acid of 5-10wt% and the additive of 5-10wt%, wt% are all based on amino The total weight of acid, amino-acid salt, organic acid and additive.

In the present invention, the amount of deliming agent is calculated based on the amount of amino acid and amino-acid salt total in deliming agent.Deliming The amount of total amino acid and amino-acid salt is preferably the 1-5wt% of the fur of liming, the more preferably 1- of the fur of liming in agent 2.5wt%.

In preferred embodiments, deliming steps include the following steps: (b-1) pre- deliming steps: with additive and organic Acid and/or carbon dioxide are by the pre- deliming of the fur of liming；And (b-2) with deliming agent by the fur deliming of liming.

Step (b-1) preferably includes: the fur of liming is washed with water in (viii), removes floating material；(ix) with additive and Organic acid and/or carbon dioxide are by the pre- deliming of the fur of liming；And (x) when the pH value of floating material is about 8, discharge floating Object.

Additive in step (b-1) is identical as the additive in above-mentioned deliming agent.

Organic acid in step (b-1) is identical as the organic acid in above-mentioned deliming agent.

In step (b-1), the amount of additive can the conventional method according to used in leather making processes selected, The preferably 0.05-0.3wt% of the fur of liming.

In step (b-1), the amount of organic acid can the conventional method according to used in leather making processes selected, The preferably 0.1-0.5wt% of the fur of liming.

When deliming steps do not include pre- deliming steps (b-1), the fur of liming is taken off according to the aqueous solution of deliming agent Ash carries out deliming steps.

The amount of water can be according to used in leather making processes in step (viii) or in the aqueous solution of deliming agent Conventional method is selected, the preferably 300wt% of the fur of liming or less, the more preferably 200wt% of the fur of liming Or it is less.

Step (b-2) preferably includes: (xi) is with deliming agent by the fur deliming of liming；And (xii) terminates deliming steps.

Step (b-1) or (b-2) can be carried out at conventional temperatures, preferably 5-35 DEG C, more preferably 25-35 DEG C.

The end of deliming steps can be determined according to conventional method used in leather making processes.Preferably, work as hair The cross section of skin notch becomes colorless when phenolphthalein is added and the floating material of deliming steps is 6-8.8, when even more preferably about 8, It can terminate deliming steps.The time of deliming steps is preferably 1 to 6 hour, and more preferably 1 to 3 hour.

" about 8 " in the present invention refer to 8 ± 0.8.

During deliming steps, the pH value of floating material is preferably monitored.

Fur in the present invention can also be construed to the leather in leather manufacture field.Fur can come from leather manufacture neck Typical mammalian used in domain, such as ox, sheep, pig or deer.

The routine liming method according to used in leather making processes carries out liming to the fur of liming.

In the present invention, above-mentioned all technical characteristics can be freely combined to form preferred embodiment.

The present invention have following benefits: (1) using from leather manufacture waste (hair of liming, the shavings containing chromium and/ Or lop) convert tanning waste to the raw material of deashing method, it realizes and recycles and significantly enhance " closed loop " technique Concept；(2) raw material of deashing method does not contain boric acid, meets safety operation；(3) ammonium salt is not used, stream is significantly reduced Ammonia-values of nitrogen might in object out；(4) it is discharged during deliming without ammonia, this facilitate safety operations；(5) within the scope of deliming pH, albumen Hydrolysate has good buffer capacity, this makes it possible to successfully remove lime from the fur of liming without causing acid molten It is swollen, especially on texture layer；(6) protolysate has high solubility in water and small molecule, this is so as to quickly It penetrates into the fur of liming；(7) lead to high lime removal efficiency by the soluble calcium salt that amino-acid compound and lime are formed, This can be realized the clean fur surface of scytoblastema (crust) and soft feel.

Embodiment

Following embodiment is for illustrating the present invention, but they are not intended to limit the invention to this:

Raw material: organic acid mixture: the succinic acid of 50wt%, the adipic acid of 50wt%.

Embodiment 1

Pre-processed by the hair of following pairs of limings: (i) hair of 1500g liming is added to the 0.3mol/ of 10L In L hydrochloric acid solution (inorganic acid solution II), then stir the mixture for 2 hours；(ii) pH 6 is neutralized to sodium hydroxide solution； And (iii) is filtered to remove effluent, and hair is 2 hours dry at 50 DEG C, it is pretreated to obtain 1000g Hair.

The keratin hydrolyzate solution for being used for following deliming processes is obtained according to following step:

(a-1) hydrolyze pretreated hair: under stiring by the pretreated hair of 1000g be added to 80 DEG C, 3 hours in the hydrochloric acid solution (inorganic acid solution I) of the 38wt% of 1000mL in the autoclave of 0.6-1Mpa；

(a-2) after cooling, solid particle is removed from solution by filters pressing；With

(a-3) collecting filtrate and filtrate is neutralized to pH value with sodium hydroxide solution is 6.0, and it is molten to obtain keratin hydrolyzate Liquid (wherein amino acid content is 43wt%).

It will impregnate in a usual manner and the ox-hide of liming is used in application test.

Deliming process the following steps are included:

(b-1) pre- deliming steps:

(viii) in 30 DEG C, with 150wt%'s (poidometer that wt% is the fur based on liming) in rotary drum (drum) The fur (weight 16kg, thickness 7mm) of water washing liming；Floating material is discharged after ten minutes；

(ix) by organic acid-mixed of the water of fur 100wt% of liming, the sodium pyrosulfite of 0.15wt% and 0.3wt% The pre- deliming of mixture 30 minutes for closing object, wt% is all based on the poidometer of the fur of liming；With

(x) it measures the pH value (8.2) of floating material and floating material is discharged again；

(b-2) with deliming agent (table 1) by the fur deliming of liming, the deliming agent includes that the organic acid of 0.2wt% mixes Object, the sodium pyrosulfite of 0.15wt%, 5wt% keratin hydrolyzate solution, wt% is all based on the weight of the fur of liming Meter；After 120 minutes, when the cross section of fur notch when phenolphthalein is added to be colourless, when the pH value of floating material is 8.5, terminate Deliming steps, deliming degree are 100%.

Hereafter, using conventional method, softening, pickling, chrome tanning, retanning, in and dyeing and stuffing after obtain scytoblastema.

Embodiment 2

(a-1) hydrolyze pretreated hair: under stiring by the pretreated hair of 1000g be added to 130 DEG C, 6 hours in the hydrochloric acid solution (inorganic acid solution I) of the 10wt% of 2000mL in the autoclave of 0.6-1MPa；

(a-3) collecting filtrate and filtrate is neutralized to pH value with sodium hydroxide solution is 6.0, and it is molten to obtain keratin hydrolyzate Liquid (wherein amino acid content is 28wt%).

Deliming process the following steps are included:

(b-1) pre- deliming steps:

(viii) in 30 DEG C, with the water washing of 150wt% (poidometer that wt% is the fur based on liming) in rotary drum The fur (weight 16kg, thickness 7mm) of liming；Floating material is discharged after ten minutes；

(b-2) with deliming agent (table 1) by the fur deliming of liming, the deliming agent includes that the organic acid of 0.2wt% mixes Object, the sodium pyrosulfite of 0.15wt%, 6.5wt% keratin hydrolyzate solution, wt% is all based on the weight of the fur of liming Meter；After 120 minutes, when the cross section of fur notch when phenolphthalein is added to be colourless, when the pH value of floating material is 8.3, knot Beam deliming steps, deliming degree are 100%.

Embodiment 3

Pass through the pretreated shavings and lop in following acquisitions step (a-1):

(iv) shavings by the wet blue of 300g containing chromium and lop are cut into small pieces, and the water of 1L is added and stirs the mixture for 2 hours；Filtering removal dirt；It is immersed in the aqueous solution of the glucose of CaO, 9g of 30g and the water of 3L, impregnates 4 days；(v) lead to It is overpressurized and is filtered to remove water；(vi) it is small that 2 are soaked in the 4wt% hydrochloric acid solution (inorganic acid solution III) of the 300mL in flask When；(vii) sufficiently washing is to be discharged floating material and obtain pretreated shavings and/or lop except dechromising.

The collagen hydrolysate solution for being used for following deliming processes is obtained according to following step:

(a-1) pretreated shavings or lop are hydrolyzed: by the pretreated shavings of 300g and lop be added to 130 DEG C, in the hydrochloric acid solution (inorganic acid solution I) of the 10wt% of 300mL in the autoclave of 0.6-1MPa and stir 6 hours；

(a-3) collecting filtrate and filtrate is neutralized to pH value with sodium hydroxide solution is 6.0, obtains collagen hydrolysate Solution (wherein amino acid content is 40wt%).

Deliming process the following steps are included:

(b-1) pre- deliming steps: identical as in embodiment 1；

(b-2) with deliming agent (table 1) by the fur deliming of liming, the deliming agent includes that the organic acid of 0.2wt% mixes Object, the sodium pyrosulfite of 0.15wt%, 6wt% collagen hydrolysate solution, wt% is all based on the weight of the fur of liming Meter；After 120 minutes, when it is 8.5 that the cross section of fur notch, which is colourless and floating material pH value when phenolphthalein is added, Terminate deliming process, deliming degree is 100%.

Embodiment 4

(iv) shavings by the wet blue of 300g containing chromium and lop are cut into small pieces, and the water of 1L is added and stirs the mixture for 2 hours；Filtering removal dirt；It is immersed in the aqueous solution of the glucose of CaO, 3g of 60g and the water of 3L, impregnates 2 days；(v) lead to It crosses pressure filter and removes water；(vi) it is small to be soaked in the 15wt% hydrochloric acid solution (inorganic acid solution III) of the 300mL in flask 0.5 When；(vii) sufficiently washing is to be discharged floating material and obtain pretreated shavings and/or lop except dechromising.

(a-1) pretreated shavings or lop are hydrolyzed: by the pretreated shavings of 300g or lop be added to 90 DEG C, in the hydrochloric acid solution (inorganic acid solution I) of the 38wt% of 100mL in the autoclave of 0.6-1MPa and stir 3 hours；

(a-3) collecting filtrate and filtrate is neutralized to pH value with sodium hydroxide solution is 6.0, obtains collagen hydrolysate Solution (wherein amino acid content is 70wt%).

Deliming process the following steps are included:

(b-1) pre- deliming steps: identical as in embodiment 1；

(b-2) by the fur of liming deliming agent (table 1) deliming, the deliming agent includes that the organic acid of 0.8wt% mixes Object, the sodium formate of 1wt%, 3.5wt% collagen hydrolysate solution, wt% is all based on the poidometer of the fur of liming； After 120 minutes, when it is 7.8 that the cross section of fur notch, which is colourless and floating material pH value when phenolphthalein is added, terminate Deliming process, deliming degree are 100%.

Embodiment 5

By the collagen hydrolysate solution (amino acid content 70%) obtained in example 4 in embodiment 5.

Deliming process the following steps are included:

(b-1) pre- deliming steps:

(viii) in 30 DEG C, with the water washing of 150wt% (poidometer that wt% is the fur based on liming) in rotary drum The fur (weight 7kg, thickness 3.5mm) of liming；Floating material is discharged after ten minutes；

(ix) organic acid of the water of liming fur 100wt%, the sodium pyrosulfite of 0.15wt% and 0.3wt% is mixed The pre- deliming of the mixture of object 30 minutes, wt% is all based on the poidometer of the fur of liming；With

(b-2) by the fur of liming deliming agent (table 1) deliming, the deliming agent includes that the organic acid of 0.2wt% mixes Object, the sodium pyrosulfite of 0.2wt%, 1.5wt% collagen hydrolysate solution, wt% is all based on the weight of the fur of liming Meter；After 120 minutes, when it is 7.6 that the cross section of fur notch, which is colourless and floating material pH value when phenolphthalein is added, knot Beam deliming steps, deliming degree are 100%.

Comparative example 1

Deliming process the following steps are included:

(b-1) pre- deliming steps are identical as in embodiment 1；

(b-2) deliming steps:

With the organic acid mixture of 0.2wt%, the sodium pyrosulfite of 0.15wt%, 1.5wt% ammonium sulfate and 0.5wt% Ammonium chloride deliming, wt% is all based on the poidometer of the fur of liming；After 120 minutes, when the cross section of fur notch is adding When entering phenolphthalein to be colourless and floating material pH value be 8.4, terminate deliming process, deliming degree is 100%.

All floating materials of embodiment 1-5 and comparative example 1 are obtained to check NH₃- N value.The deliming result of each embodiment It is shown in Table 2 with scytoblastema effect.

Table 1

Table 2

As shown in table 2, carry out deliming with ammonium salt, collagen hydrolysate, keratin hydrolyzate and reach final ph be about 8, it means that amino acid has the buffer capacity similar with ammonium salt.In addition, the deliming effluent of amino acid has about 100ppm NH₃- N value is less than the 5% of ammonium salt deliming effluent.Low NH₃- N value can significantly reduce effluent processing time and cost.

The scytoblastema obtained from all embodiments all has uniform color, soft feel and very fine and smooth texture, It is suitable with comparative example 1.

Claims

1. deashing method comprising deliming steps: using the deliming agent without ammonium and boric acid by the fur deliming of liming, the deliming Agent includes protolysate, and the protolysate is prepared according to method comprising the following steps: (A) hydrolysis hair, is repaired at shavings Object and/or feather are cut to generate amino acid and/or amino-acid salt, then obtains the protolysate.

2. deashing method as described in claim 1, which is characterized in that described to be hydrolyzed to sour water solution, packet in step (A) Include following steps:

(a-1) at 80-130 DEG C, hair, shavings, lop and/or feather are hydrolyzed in inorganic acid solution I；

(a-2) insoluble matter is removed by filters pressing；

(a-3) filtrate is neutralized to pH value with the alkali compounds without ammonium is 4-7, obtains protolysate solution；

And optionally, (a-4) is spray-dried the protolysate solution and obtains the protolysate.

3. such as deashing method of any of claims 1-2, which is characterized in that in step (a-1), the inorganic acid The inorganic acid of solution I includes at least one selected from the following: hydrochloric acid, sulfuric acid, nitric acid and phosphoric acid；In the inorganic acid solution I The content of inorganic acid is 5-40wt%.

4. deashing method as described in any one of the preceding claims, which is characterized in that described in the hydrolysis in step (a-1) When hair, based on the total weight of the inorganic acid solution I and the hair, the amount of the hair is 10-50wt%, preferably 20-50wt%, more preferably 30-50wt%；When hydrolyzing the shavings and/or the lop in step (a-1), it is based on The amount of the total weight of the inorganic acid solution I, the shavings and the lop, the shavings and the lop is 40- 80wt%, preferably 50-75wt%.

5. deashing method as described in any one of the preceding claims, which is characterized in that described in the hydrolysis in step (a-1) When hair, the content of the inorganic acid in the inorganic acid solution I is 10-38wt%；The hydrolysis of the hair is at 80-130 DEG C It carries out.

6. deashing method as described in any one of the preceding claims, which is characterized in that described in the hydrolysis in step (a-1) When shavings and/or the lop, the content of the inorganic acid in the inorganic acid solution I is 10-40wt%；The shavings and/ Or the hydrolysis of the lop carries out at 80-130 DEG C.

7. deashing method as described in any one of the preceding claims, which is characterized in that described to be free of in step (a-3) The alkali compounds of ammonium includes at least one selected from the following: sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, sodium bicarbonate And saleratus.

8. deashing method as described in any one of the preceding claims, which is characterized in that when the hydrolysis hair in step (A) When hair, the hair is the hair Jing Guo pretreated liming before hydrolysis, the pretreatment of the hair of the liming include with Lower step: (i) washs the hair of the liming with inorganic acid solution II, and (ii) neutralization inorganic acid solution II to pH value is 5- 8, and (iii) removing effluent, it is dry simultaneously to obtain pretreated hair.

9. deashing method as described in any one of the preceding claims, which is characterized in that

In step (i), the content of the inorganic acid in the inorganic acid solution II is 0.3-2mol/L；The amount of inorganic acid solution II It is 3-20 times of the hair weight of the liming；The inorganic acid of the inorganic acid solution II includes at least one selected from the following: Hydrochloric acid, sulfuric acid, nitric acid and phosphoric acid；

In step (ii), using inorganic acid solution II described in alkali neutralization, the alkali includes at least one selected from the following: hydrogen-oxygen Change sodium, potassium hydroxide, sodium carbonate, potassium carbonate, sodium bicarbonate and saleratus.

10. deashing method as described in any one of the preceding claims, which is characterized in that described in the hydrolysis in step (A) When shavings and/or the lop, the shavings and/or the lop are before hydrolysis by the pretreated leather containing chromium Bits and/or lop, the pretreatment to the shavings containing chromium and/or lop is the following steps are included: institute is washed with water in (iv) Shavings and/or lop containing chromium are stated, crude removal is removed, is immersed in the solution of calcium oxide, glucose and water；(v) water is removed, (vi) the de- chromium of acid, and (vii) washing are carried out with except dechromising and obtain pretreated shavings and/or repair with inorganic acid solution III Cut object.

11. deashing method as described in any one of the preceding claims, which is characterized in that

In step (iv), the amount of the water is 3-20 times of the shavings containing chromium and lop weight；Weight based on water, The content of calcium oxide is 1-3wt% in the solution；Weight based on water, the content of the glucose in solutions are 0.1- 0.3wt%；

In step (vi), the content of the inorganic acid in the inorganic acid solution III is 4-15wt%；The inorganic acid solution The inorganic acid of III includes at least one selected from the following: hydrochloric acid, sulfuric acid, nitric acid and phosphoric acid.

12. deashing method as described in any one of the preceding claims, which is characterized in that the deliming agent also includes organic acid And/or carbon dioxide and/or additive.

13. deashing method as claimed in claim 12, which is characterized in that the organic acid includes selected from the following at least one Kind: lactic acid, citric acid, adipic acid, malonic acid, succinic acid, glutaric acid and gluconic acid；Preferably succinic acid or adipic acid.

14. deashing method as claimed in claim 12, which is characterized in that the additive includes selected from the following at least one Kind: manganese sulfate, manganese chloride, manganese acetate, sodium formate, potassium formate, sodium hydrogensulfite, sodium pyrosulfite, potassium metabisulfite, acetic acid Sodium, potassium acetate, sodium sulphate, potassium sulfate, sodium bisulfate, potassium acid sulfate, SODIUM PERCARBONATE and potassium percarbonate.

15. the deashing method as described in any one of claim 12-14, which is characterized in that the deliming agent also includes amino Acid constituents, the amino acid composition include amino acid, amino-acid salt, and/or other eggs containing amino acid and/or amino-acid salt White hydrolysate.

16. deashing method as claimed in claim 15, which is characterized in that the amino acid includes selected from the following at least one Kind: glycine, alanine, valine, leucine, isoleucine, phenylalanine, tryptophan, tyrosine, histidine, serine, Threonine, cysteine, aspartic acid, glutamic acid, asparagine, glutamine, lysine, arginine, proline, first sulphur ammonia Acid and selenocysteine；Preferably comprise at least one selected from the following: glycine, serine, asparagine, leucine, paddy Glutamine and/or lysine；The amino-acid salt includes alkali metal salt and/or hydrochloride；The alkali metal be preferably sodium and/or Potassium.

17. the deashing method as described in any one of claim 12-16, which is characterized in that total ammonia in the deliming agent The content of base acid and amino-acid salt be 40-100wt%, preferably 55-100wt%, more preferably 70-100wt%, most preferably 80-100wt%, wt% are the total weights based on the amino acid, the amino-acid salt, the organic acid and the additive Meter.

18. the deashing method as described in any one of claim 12-17, which is characterized in that the organic acid in the deliming agent Content be 40wt% or less；Preferably 5-20wt%；More preferably 5-10wt%, wt% are based on the amino acid, institute State the total weight of amino-acid salt, the organic acid and the additive.

19. the deashing method as described in any one of claim 12-18, which is characterized in that the additive in the deliming agent Content be 25wt% or less, preferably 1-10wt%, wt% are based on the amino acid, the amino-acid salt, described have The total weight of machine acid and the additive.

20. the deashing method as described in any one of claim 12-19, which is characterized in that the deliming agent includes wherein total Amino acid and amino-acid salt content be 55-94wt% protolysate, the organic acid and 1- of 5-20wt% The additive of 25wt%, wt% are all based on the amino acid, the amino-acid salt, the organic acid and the additive Total weight.

21. deashing method as claimed in claim 20, which is characterized in that the deliming agent includes wherein total amino acid and ammonia The content of base hydrochlorate is the protolysate of 80-90wt%, the addition of the organic acid and 5-10wt% of 5-10wt% Agent, wt% are all based on the total weight of the amino acid, the amino-acid salt, the organic acid and the additive.

22. deashing method as described in any one of the preceding claims, which is characterized in that based on total in the deliming agent The amount of amino acid and amino-acid salt calculates the amount of the deliming agent, total amino acid and amino-acid salt in the deliming agent Amount is the 1-5wt%, the 1-2.5wt% of the fur of the preferably described liming of the fur of the liming.

23. the deashing method as described at least one of the claims, which is characterized in that the deliming steps include following Step: (b-1) pre- deliming steps: with the additive and the organic acid and/or carbon dioxide that the fur of the liming is pre- Deliming；(b-2) is with the deliming agent by the fur deliming of the liming.

24. deashing method as described in any one of the preceding claims, which is characterized in that the step (b-1) includes: (viii) fur of the liming is washed with water, removes floating material；(ix) with the additive and the organic acid and/or dioxy Change carbon for the pre- deliming of the fur of the liming；(x) when the pH value of floating material is 7.2-8.8, the floating material is discharged.

25. deashing method as described in any one of the preceding claims, which is characterized in that in step (b-1), the addition The amount of agent is the 0.05-0.3wt% of the fur of the liming；The amount of the organic acid is the 0.1- of the fur of the liming 0.5wt%.