CN105666612A

CN105666612A - Flame-retardant thermal modification wood and preparation method thereof

Info

Publication number: CN105666612A
Application number: CN201511021022.7A
Authority: CN
Inventors: 储德淼; 母军; 张峰; 薛磊; 张宇
Original assignee: Beijing Forestry University
Current assignee: Beijing Forestry University
Priority date: 2015-12-30
Filing date: 2015-12-30
Publication date: 2016-06-15
Anticipated expiration: 2035-12-30
Also published as: CN105666612B

Abstract

The invention relates to flame-retardant thermal modification wood and a preparation method thereof. The preparation method comprises the step that after being subjected to immersion treatment, the wood is subjected to heat treatment. According to the flame-retardant thermal modification wood and the preparation method thereof, the flame-retardant thermal modification wood is prepared by combining the wood high-temperature heat treatment with the wood flame-retardant technology; the dual characteristics that the wood is subjected to high-temperature heat treatment and flame retarding are achieved at the same time; the flame-retardant thermal modification wood has the good surface decorative performance, dimensional stability and the like, and the excellent flame-retardant property is also achieved; the combustion heat release rate and smoke production are substantially decreased, and the fireproof safety of processed wood products is greatly increased.

Description

A kind of fire-retardant hot modified wood and its preparation method

Technical field

The present invention relates to a kind of heat-treated wood and its preparation method, in particular to the fire-retardant heat-treated wood of one and preparation thereof, belong to the hot modification treatment technology field of timber.

Background technology

Existing research shows; timber high-temperature heat treatment is generally under vacuum or the shielding gas such as water vapour, nitrogen; raised temperature is between 160-260 DEG C; timber generation physical-chemical reaction is made by heat; reach the object improving its performance; soaking time is generally 2-10 hour, and the part treatment time even to be reached more than 10 hours. High-temperature heat treatment can give superior wood dimensional stability, biodurable, rotproofness and safety, the feature of environmental protection etc. Heat-treated wood is widely used in furniture, architectural decoration and structures, wood staircase, park facility and sauna inner facility etc. Owing to heat_treated wood temperature height and treatment time are long, hemicellulose palliating degradation degree is big, and acid product destroys the structure of Mierocrystalline cellulose further so that the polymerization degree decline of Mierocrystalline cellulose, finally causing process material physical strength to reduce about 10%-30%, surface hardness and wear resistance reduce; In addition, owing to timber has combustibility, high-temperature heat treatment process can not solve its flammability, and high-temperature heat treatment material is directly applied exists fire safety evaluating hidden danger. GB50016 " Code for fire protection design of buildings " and GB20286 " public place fire-retardant product and assembly combustionproperty require and mark " issues and implements, and wherein clear stipulaties architectural design, public arena goods must use Environmental Safety fire retardant material. So, heat-treated wood needs to carry out the safety in utilization that fire-retardant finish could ensure its goods further.

There is performances such as mainly improving emphatically the dimensional stability of timber and resistance to corruption about timber high-temperature heat treatment technology in China, the Chinese patent application being CN101623887A such as: publication number discloses " treatment process of a kind of timber and the timber prepared by the method ", and the method comprises the timber being opposite in container successively and carries out reduced pressure treatment, thermal pretreatment, high-temperature pressurizing process and conditioning. The treating processes of timber keeps higher equilibrium moisture content, the timber of preparation overcomes the seasoning defect drying defects such as cracking, shrinkage, process material cracking proportion, water absorbability, water absorbing properties much slower, weathering resistance and erosion resistance improve and reach " charing wood " SB/T10508-2008 standard. This treatment process adopts water vapor as medium, has the treatment time short, the feature that calorific loss is little, the inventive method save energy, and treating of wood is originally low.

The Chinese patent application that publication number is CN104400866A discloses one " production and processing method of paulownia wood homogeneity charing wood ", the method specifically by sanction saw, degreasing, drying, moisture regain, stacking, enter kiln, intensification, charing, lower the temperature, go out kiln totally ten one procedures complete, skimming treatment is laid a solid foundation for realizing homogeneity charing, when entering kiln with kaolin, timber is coated, with completely isolated air, carbonization temperature is reduced on the whole after envelope kiln, extend carbonization time, thus reach even charred effect. Paulownia charing degree for the treatment of is even, color, water absorbability and every mechanical property demonstrate identical superperformance, it is to increase the using value of product and economic benefit.

China has about Wood flame-retarded technology mainly emphatically and improve wood fire retardant performance, the Chinese patent application being CN104210002A such as publication number discloses " a kind of composite flame-retardant agent, preparation method and its usage ", a kind of composite flame-retardant agent of this disclosure of the invention, comprise polysilicon acid phosphate dihydrogen aluminum solution and nitrogen phosphorus fire retardant solution, prepare polysilicon acid phosphate dihydrogen aluminum solution and nitrogen phosphorus fire retardant solution respectively, mixing even by both again and get final product, this composite flame-retardant agent has obvious flame-retardant smoke inhibition effect. The Chinese patent application that publication number is CN103722600A discloses " a kind of Wood modifier and its preparation method ", and this Wood modifier comprises following composition by weight: phosphoric acid 20～200 parts; 20～100 parts, urea; Catalyzer 0.1～1.0 part; 5～20 parts, tetra methylol sulfuric acid phosphorus; Aluminium triphosphate 2～15 parts; Sulfosuccinate dioctyl ester sodium salt 0.1～2.5 part; 40～200 parts, water. Not only flame retardant effect is remarkable for this Wood modifier, and has good dimensional stabilizing function. Process timber rate of body weight gain is when about 20%, and oxygen index can reach more than 50%, dimensional stability ASE can reach more than 35%. Wood fire retardant preparation method provided by the invention is simple, and cost is lower, is applicable to promoting the use of. Research about high-temperature heat treatment fire-retardant finish is very few, the Chinese patent application being CN204357064U such as publication number discloses " a kind of charing flame retardant solid composite floor ", propose a kind of charing flame retardant solid composite floor, inflaming retarding finish paint layer, flame resistant char surface layer, the first fire-retardant enhancement layer, charing core layer, the 2nd fire-retardant enhancement layer, charing bottom and back of the body prime coat successively superposition are arranged. Charing surface layer improves floor aesthetics, and the carbonated material structure of superposition improves the dimensional stability on floor successively, compensate for the adding of fire-retardant enhancing structural sheet charing and processes the loss of strength brought.

Not yet find at present the relevant patent of the timber fire-retardant processing method that combines to high-temperature heat treatment and the method prepared.

Summary of the invention

It is an object of the invention to the problem for the technology existed in above existing timber high-temperature thermal treatment timber, fire-retardant timber and preparation process thereof and a kind of fire-retardant hot modified wood and its preparation method are provided. First the present invention adopts fire retardant that timber is carried out dip treating, then carries out high-temperature heat treatment, thus reaches and obtain the good high-temperature thermal treatment timber of flame retardant properties, and the present invention prepares the fire retardant drug loading height of fire-retardant hot modification timber, and flame retardant effect is strong; Wood dimensional stability height, surface hardness fall is little; And the surface color of fire-retardant hot modified wood is tending towards brown, there is good color decorate properties.

For realizing the object of the present invention, one aspect of the present invention provides the preparation method of a kind of fire-retardant hot modified wood, comprises and being heat-treated by the timber after dip treating.

Wherein, described heat treated temperature is 130-160 DEG C, it is preferable to 140-150 DEG C;Described heat treatment time is 20-50min, it is preferable to 20-40min, more preferably 30min.

Particularly, described dip treating comprises timber successively under a reduced pressure, soaks under atmospheric pressure state.

Wherein, described immersion under a reduced pressure is vacuum impregnation process; Immersion under atmospheric pressure state is normal pressure dip treating.

Particularly, vacuum tightness < 0MPa, it is preferable to-0.01～-0.1MPa, more preferably-0.05～-0.1MPa in described vacuum impregnation treating processes; The vacuum impregnation treatment time is 15-45min, it is preferable to 20-40min, more preferably 30min; In described normal pressure dip treating process, relative pressure is 0MPa; The time of normal pressure dip treating is 15-45min, it is preferable to 20-40min, more preferably 30min.

Wherein, described dip treating is first soaked by timber and in retardant solution, then successively under a reduced pressure, soaks under atmospheric pressure state.

Particularly, the fire retardant in described retardant solution is for selecting nitrogen phosphorus fire retardant or modification nitrogen phosphorus fire retardant, it is preferable to modification nitrogen phosphorus fire retardant, more preferably polysilicon acid aluminium dihydrogen phosphate modification nitrogen phosphorus fire retardant.

Especially, the mass percent concentration of described retardant solution is 5-15%, it is preferable to 10%.

The present invention provides the preparation method of a kind of fire-retardant hot modified wood on the other hand, comprises the step that following order carries out:

1) timber is immersed in retardant solution, under decompression state, carries out vacuum impregnation process, obtain vacuum impregnation timber;

2) continue to be immersed in retardant solution by vacuum impregnation timber, under atmospheric pressure state, carry out normal pressure dip treating, obtain normal pressure dipping timber;

3) normal pressure is flooded timber and it is dried process, obtain flame-retardant impregnating timber;

4) flame-retardant impregnating timber is heat-treated.

Wherein, step 1) described in retardant solution select nitrogen phosphorus fire retardant solution or modification nitrogen phosphorus fire retardant solution, it is preferable to modification nitrogen phosphorus fire retardant solution, more preferably polysilicon acid aluminium dihydrogen phosphate modification nitrogen phosphorus fire retardant solution.

Particularly, described nitrogen phosphorus fire retardant selects BL environmental protection fire retarding agent; Modification nitrogen phosphorus fire retardant is modification BL environmental protection fire retarding agent, namely adopts polysilicon acid aluminium dihydrogen phosphate modification BL environmental protection fire retarding agent.

Especially, described BL environmental protection fire retarding agent is the nitrogen phosphorus flame retardant of Beijing Forestry University's development.

Wherein, the mass percent concentration of described retardant solution is 5-15%, it is preferable to 10%.

Particularly, nitrogen phosphorus fire retardant or modification nitrogen phosphorus fire retardant being mixed with water, stir, be uniformly dissolved, obtain described retardant solution, the percentage concentration of preparing of wherein said retardant solution is 5-15%, it is preferable to 10%.

Wherein, described nitrogen phosphorus fire retardant is prepared from accordance with the following steps:

A) raw material is prepared according to following weight:

Phosphoric acid (concentration is 85%) 7-11

Urea 3.5-4.5

Catalyzer 0.025-0.035

Wherein, catalyzer comprises the raw material of following weight: tin chloride 0.8-1.2, copper sulfate 1.5-2.5, sodium-chlor 0.8-1.2, iron(ic) chloride 0.8-1.2, Tai-Ace S 150 0.8-1.2, boric acid 0.8-1.2, zinc chloride 1.5-2.5, is ground mixing after evenly;

B) add phosphoric acid in a kettle., stir and heat simultaneously, make rise in temperature to 50-60 DEG C;

C) add urea, the mixture of phosphoric acid and urea is stirred, make material distribution, be heated evenly;

D) when rise in temperature is to 90-120 DEG C, in reactor, add catalyzer, continue heating;

E) make rise in temperature to after 130-150 DEG C, when reactant volume is increased to 2-2.5 times of original volume, stopping heating;

F) product in reactor is poured out, treat its cooling curing, to obtain final product.

Particularly, described stirring velocity controls at 50-70 rev/min.

Wherein, described modification nitrogen phosphorus fire retardant is prepared from accordance with the following steps:

1) polysilicon acid phosphate dihydrogen aluminum solution is prepared

1A) being added to the water by aluminium dihydrogen phosphate, stir, be uniformly dissolved, make phosphate dihydrogen aluminum solution, wherein, the mass percent concentration of phosphate dihydrogen aluminum solution is 15-25%;

1B) being added to the water by silicate, stir, be uniformly dissolved, make silicate solutions, wherein, the mass percent concentration of silicate solutions is 1-5%;

1C) slowly being poured in phosphate dihydrogen aluminum solution by silicate solutions, stir and leave standstill, obtain polysilicon acid phosphate dihydrogen aluminum solution, wherein the mass ratio of silicate solutions and phosphate dihydrogen aluminum solution is 100:40-117.

2) nitrogen phosphorus fire retardant is prepared

2A) prepare raw material according to following weight:

Phosphoric acid (concentration is 85%) 7-11

Urea 3.5-4.5

Catalyzer 0.025-0.035

2B) add phosphoric acid in a kettle., stir and heat simultaneously, make rise in temperature to 50-60 DEG C;

2C) add urea, the mixture of phosphoric acid and urea is stirred, make material distribution, be heated evenly;

When 2D) rise in temperature is to 90-120 DEG C, in reactor, add catalyzer, continue heating;

2E) make rise in temperature to after 130-150 DEG C, when reactant volume is increased to 2-2.5 times of original volume, stopping heating;

2F) product in reactor is poured out, treat its cooling curing, obtain nitrogen phosphorus fire retardant.

3) modification nitrogen phosphorus fire retardant is prepared

3A) being added to the water by nitrogen phosphorus fire retardant, mix with water, be mixed with nitrogen phosphorus fire retardant solution, wherein the mass percent concentration of nitrogen phosphorus fire retardant solution is 25-35%;

3B) slowly being poured into by polysilicon acid phosphate dihydrogen aluminum solution in nitrogen phosphorus fire retardant solution, stir and leave standstill, obtain modification nitrogen phosphorus fire retardant, wherein the weight of polysilicon acid phosphate dihydrogen aluminum solution and the weight ratio of nitrogen phosphorus fire retardant solution are 20-50:100.

Particularly, step 1A) described in phosphate dihydrogen aluminum solution mass percent concentration be preferably 20%; Step 1B) described in silicate solutions mass percent concentration be preferably 3%; Described silicate selects water glass, potassium silicate or lithium silicate; Step 1C) described in the mass ratio of silicate solutions and phosphate dihydrogen aluminum solution be preferably 100:50; Step 3A) described in nitrogen phosphorus fire retardant solution mass percent concentration be preferably 30%; Step 3B) described in the weight ratio of the weight of polysilicon acid phosphate dihydrogen aluminum solution and nitrogen phosphorus fire retardant solution be preferably 25:100.

Wherein, step 1) described in vacuum tightness < 0MPa in vacuum impregnation treating processes, it is preferable to-0.01～-0.1MPa, more preferably-0.05～-0.1MPa; The vacuum impregnation treatment time is 15-45min, it is preferable to 20-40min, more preferably 30min.

Particularly, the vacuum tightness in described vacuum impregnation treating processes is preferably-0.05MPa; The vacuum impregnation treatment time is 15-45min, it is preferable to 20-40min, more preferably 30min.

Wherein, step 2) described in relative pressure in normal pressure dip treating process be 0MPa; The time of normal pressure dip treating is 15-45min, it is preferable to 20-40min, more preferably 30min.

Particularly, step 2) described in fire retardant select nitrogen phosphorus fire retardant or modification nitrogen phosphorus fire retardant, it is preferable to modification nitrogen phosphorus fire retardant, more preferably polysilicon acid aluminium dihydrogen phosphate modification nitrogen phosphorus fire retardant.

Wherein, step 3) described in drying treatment temperature be 100-103 DEG C, it is preferable to 103 DEG C; Time of drying >=6h; Water ratio≤15% of described flame-retardant impregnating timber, it is preferable to 7-15%, more preferably 10%.

Particularly, also comprise step 3A): the timber after normal pressure is flooded in ambient temperatare put 5-10d (my god) after, then carry out described drying treatment; It is preferably and carries out described drying treatment again after placing 7d.

Wherein, step 4) described in the temperature of heat_treated wood be 130-160 DEG C, it is preferable to 140-150 DEG C; Described heat treatment time is 20-50min, it is preferable to 20-40min, more preferably 30min.

Particularly, step 4) described in heat_treated wood be that the temperature of timber is increased to 130-160 DEG C by the temperature rise rate with 5-20 DEG C/min, keep 20-50min when temperature is 130-160 DEG C, it is preferable to 20-40min, more preferably 30min.

Especially, described heat_treated wood is that the temperature of timber is increased to 130-160 DEG C by the temperature rise rate with 10-15 DEG C/min, keeps 20-50min when temperature is 130-160 DEG C, it is preferable to 20-40min, more preferably 30min.

Particularly, described heat_treated wood is that the temperature of timber is increased to 140-150 DEG C by the temperature rise rate with 10-15 DEG C/min, keeps 20-40min when temperature is 140-150 DEG C, it is preferable to 30min.

Particularly, also comprise and heat-treated wood is carried out conditioning, make the water ratio of heat-treated wood reach 8-12%, it is preferable to 10%.

Especially, being placed in climatic chamber by the timber after thermal treatment, after making thermal treatment, the water ratio of timber reaches 8-12%, it is preferable to 10%.

Another aspect of the invention provides a kind of modified wood being prepared from according to above-mentioned treatment process.

Compared with existing hot modified wood and its preparation method, tool of the present invention has the following advantages:

1, timber is adopted fire-retardant hot modified wood prepared by flame-retardant impregnating process, fire-retardant finish material cryodrying, fire-retardant finish material high-temperature heat treatment combination treatment by the inventive method, there is high-temperature heat treatment and fire-retardant timber dual nature simultaneously: both there are good decorative surface, dimensional stability etc., there is again excellent flame retardant properties, combustion heat rate of release and cigarette output much slower, the greatly fire savety of increase process material products;

2, timber is carried out flame-retardant impregnating process by the present invention under vacuum negative pressure condition, and in timber, the drug loading of fire retardant is higher than 30kg/m³, flame retardant properties is good; Wet swelling rate is low, and radial wet swelling rate is lower than 1.5%; String to wet swelling rate lower than 1.5%; Volume wet swelling rate is lower than 3.1%; Anti-wet swollen coefficient height, radial anti-wet expansion factor is greater than 21.8%; String is greater than 45% to anti-wet expansion factor; The dimensional stability height of timber.

3, the preparation method of the fire-retardant hot modification timber of the present invention is simple, compare prior heat treatment process, in reduction production cost and energy-conserving and environment-protective, there is obvious advantage: adopt nitrogen phosphorus fire retardant as catalyzer, can be at a lower temperature, timber dewatering carbonization is impelled in short period of time, reduce power consumption of polymer processing, shorten the production time.Thermal treatment target temperature is reduced to 140-150 DEG C by 160 DEG C-260 DEG C, and soaking time shortens to about 30min by 2-10h.

4, the preparation method of the fire-retardant hot modified wood of the present invention, fire retardant is utilized to promote Mierocrystalline cellulose pyrolysis carbonization principle under high temperature (>=130 DEG C), catalyzer timber dewatering in high-temperature heat treatment process, accelerate timber high temperature cabonization process, reduce Wood carbonization target temperature, shorten high-temperature heat treatment soaking time, reach the object reducing energy consumption; In the inventive method, the introducing of fire retardant is not only given the good flame retardant properties of fire-retardant hot modification timber but also makes timber have good dimensional stability, colourity attractive in appearance, has excellent color decorate properties.

5, the lightness L* of the fire-retardant hot modified wood of the present invention reduces, and red green axle chromaticity index a*, champac axle chromaticity index b* increase, and surface color is tending towards brown, Color tunable control, and decorate properties improves.

6, when the fire-retardant hot modified wood of the present invention burns, low temperature heat release rate peak value is compared common high-temperature heat treatment material and is reduced by 48.45%, and initial stage burning degree declines to a great extent, and can effectively slow down fire spreading; High temperature exothermic peak time of occurrence postpones 147s, and total heat release rate reduces by 36.6%, and total combustion degree obviously reduces; Fire retardant occurs to distribute in heat treatment process again, and fire retardant reunion crystallization degree reduces, and fire retardant distribution is more even; And there is Chemical bond between fire retardant and timber, anti-current was lost efficacy and was really strengthened, fire retardant is conducive to preserve in wood, flame retardant effect is lasting, and the low molecular compound that in nitrogen phosphorus fire retardant, contained unreacted has stronger water absorbability completely decomposes in heat treatment process such as urea etc., improve the shortcoming of nitrogen phosphorus fire retardant process material water absorbability.

Accompanying drawing explanation

Fig. 1 is the heat release rate HRR graphic representation of the heat-treated wood prepared of embodiment of the present invention 2-4, reference examples 1-4 and former material test specimen;

Fig. 2 is the total smoke release TSR graphic representation of the heat-treated wood prepared of embodiment of the present invention 2-4, reference examples 1-4 and former material test specimen;

Fig. 3 is the electron-microscope scanning figure of fire-retardant hot modified wood prepared by the embodiment of the present invention 2;

Fig. 4 is the electron-microscope scanning figure of the hot modified wood of reference examples 4 of the present invention preparation.

Embodiment

Although it is above-mentioned to invention has been detailed explanation; but the present invention is not limited thereto; those skilled in the art can modify according to the principle of the present invention, and therefore, the various amendment that all principles according to the present invention carry out all should be understood to fall into protection scope of the present invention.

Timber handled by the present invention both can select wildwood timber, can select again artificial forest fast growing wood, and the preparation process of the modified wood of the present invention is described in detail for quick growth poplar wood (Poplus.app) in the embodiment of the present invention. Quick growth poplar wood is adopted in Lay forest farm, Sichuan, and average air dry density is 355kg/m³, water ratio is 7%, and density is 0.4g/cm³; Make the wooden unit that size is respectively 3000mm (longitudinal direction) × 95mm (string to) × 28mm (radial direction), according to standard GB/T 1928-2009 sawing.

Timber in the embodiment of the present invention is except quick growth poplar wood, and other timber are all applicable to the present invention such as eucalyptus wood, China fir, pine etc.

Aluminium dihydrogen phosphate (chemical pure), phosphoric acid (concentration 85%, chemical pure), urea (content 99%, chemical pure), tin chloride (chemical pure), copper sulfate (chemical pure), sodium-chlor (chemical pure), iron(ic) chloride (chemical pure), Tai-Ace S 150 (chemical pure), boric acid (chemical pure), zinc chloride (chemical pure), water glass (chemical pure), all purchased from Beijing chemical reagents corporation.

Embodiment 1 prepares modification nitrogen phosphorus fire retardant

1, polysilicon acid phosphate dihydrogen aluminum solution is prepared

1A) being added to the water by biphosphate aluminium powder form, stir, be uniformly dissolved, make phosphate dihydrogen aluminum solution, wherein, the mass percent concentration of phosphate dihydrogen aluminum solution is 20%, and namely every 100g aluminium dihydrogen phosphate is dissolved in 400g water;

1B) being added to the water by water glass, stir, be uniformly dissolved, make silicate solutions, wherein, the mass percent concentration of sodium silicate solution is 3%, and namely every 3g water glass is dissolved in 97g water;

In the present invention, the concentration of phosphate dihydrogen aluminum solution is except 20%, and concentration is all applicable to the present invention at the phosphate dihydrogen aluminum solution of 15-25%; The concentration of described silicate solutions is except 3%, and the silicate solutions that concentration is 1-5% is all applicable to the present invention; Prepare in the process of silicate solutions, except selecting water glass, it is also possible to select potassium silicate, lithium silicate.

1C) silicate solutions that mass percent concentration is 3% is slowly poured in the phosphate dihydrogen aluminum solution that mass percent concentration is 20%, stir and leave standstill, obtaining polysilicon acid phosphate dihydrogen aluminum solution, wherein the mass ratio of silicate solutions and phosphate dihydrogen aluminum solution is 100:50.

The embodiment of the present invention is described by 100:50 of the mass ratio of silicate solutions and phosphate dihydrogen aluminum solution, prepare in polysilicon acid phosphate dihydrogen aluminum solution process, the mass ratio of silicate solutions and phosphate dihydrogen aluminum solution is except 100:50, and the mass ratio of sodium silicate solution and phosphate dihydrogen aluminum solution is that 100:40-117 is all applicable to the present invention.

2, nitrogen phosphorus fire retardant is prepared

2A) prepare raw material according to following weight proportion:

Phosphoric acid (concentration is 85%) 750g

Urea (content 99%) 400g

Catalyzer 3g

Wherein, catalyzer is Beijing Forestry University's Materials science and the pistac pulvis of technical college's environmental protection flame retardant technique center preparation, the weight of raw material is: tin chloride 1.2, copper sulfate 1.5, sodium-chlor 0.8, iron(ic) chloride 1.2, Tai-Ace S 150 1.2, boric acid 1.2, zinc chloride 2.5, is ground mixing after evenly;

In the present invention, the nitrogen phosphorus fire retardant of preparation is according to patent of invention (denomination of invention: a kind of fire retardant and its preparation method; The patent No.: 200710122243.2) be prepared from. Patent of invention (the patent No.: the fire retardant 200710122243.2) prepared all is applicable to the present invention.

2B) raw material phosphoric acid is joined in reactor (described reactor is furnished with agitator under whipped state, thermometer, pressure warning unit and prolong), stir and heat simultaneously, until adding urea during the rise in temperature to 60 DEG C of material in reactor phosphoric acid, continue to heat while stirring, make to add catalyzer during the rise in temperature to 110 DEG C of mixture, continue to heat while stirring, mixture is reacted, until after the temperature of reaction mixture reaches 130 DEG C, observing response phenomenon while heating, along with temperature raises, greenish liquid becomes oyster white dope gradually, foam sharply increases, rate of rise in temperature is obviously accelerated, the rapid spatial expansion of material, prolong has a large amount of gas to discharge, it is mainly ammonia and water vapour, absorb with water, heating is stopped when the volume of reactant is increased to the twice of original volume in question response still, continue to stir, material in reactor relies on the heat release of self at vigorous reaction, temperature continues to rise, question response tends to be steady, and temperature no longer rises, when temperature starts to decline, show that reaction is complete, wherein controlling stirring velocity is 70 revs/min,

2C) the oyster white dope in reactor is poured out, it is placed in ventilating kitchen, be cooling curing after 30-60 minute, then pulverize the nitrogen phosphorus fire retardant powder that can obtain powdery with pulverizer.

3, modification nitrogen phosphorus fire retardant is prepared

3A) nitrogen phosphorus fire retardant powder is added to the water, mix with water, it is mixed with nitrogen phosphorus fire retardant solution, wherein the mass percent concentration of nitrogen phosphorus fire retardant solution is 30%, namely every 300g nitrogen phosphorus fire retardant powder is dissolved in water 700g, is mixed with the described nitrogen phosphorus fire retardant solution that mass percent concentration is 30%;

In the embodiment of the present invention, the concentration of nitrogen phosphorus fire retardant solution is except for 30%, and the nitrogen phosphorus fire retardant solution that concentration is 25-35% is all applicable to the present invention.

Polysilicon acid phosphate dihydrogen aluminum solution 3B) step 1 prepared slowly is poured in the nitrogen phosphorus fire retardant solution that mass percent concentration is 30%, stir and leave standstill, obtaining modification nitrogen phosphorus fire retardant, wherein the weight of polysilicon acid phosphate dihydrogen aluminum solution and the weight ratio of nitrogen phosphorus fire retardant solution are 25:100.

The embodiment of the present invention prepares in modification nitrogen phosphorus fire retardant process that the weight of polysilicon acid phosphate dihydrogen aluminum solution and the weight ratio of nitrogen phosphorus fire retardant solution are except 25:100, and the weight ratio of other 20-50:100 is all applicable to the present invention.

Embodiment 2 prepares fire-retardant hot modified wood

1, modified flame-retardant agent solution is prepared

Modification nitrogen phosphorus fire retardant embodiment 1 prepared is dissolved in water, and stirring and dissolving is even, obtains modified flame-retardant agent solution, and the mass percent concentration of modified flame-retardant agent solution is 10%, by every 10g modification nitrogen phosphorus fire retardant solution 90g water, to obtain final product.

Being described for the mass percent concentration of retardant solution as 10% in the embodiment of the present invention, the retardant solution of other mass percent concentrations 5-15% is all applicable to the present invention.

The fire retardant carrying out dip treating use in the present invention is except modification nitrogen phosphorus fire retardant, and nitrogen phosphorus fire retardant is also applicable to the present invention. Nitrogen phosphorus fire retardant powder embodiment 1 step 2 prepared is dissolved in water, makes the nitrogen phosphorus fire retardant solution that mass percent concentration is 5-15%, for the dip treating of timber.

2, dip treating

2-1) vacuum impregnation process

Retardant solution is poured in the impregnating autoclave that quick growth poplar wood is housed, and timber is soaked completely, connect vacuum pump; Open vacuum pump to carry out vacuumizing process, make the vacuum tightness in tank reduce and remain-0.05MPa, under a reduced pressure timber is carried out vacuum impregnation process, obtained vacuum impregnation timber, wherein, timber is 1:3 with the ratio of the volume of retardant solution, and the treatment time is 30min;

2-2) normal pressure dip treating

Close vacuum pump, open vacuum pressed tank so that in tank, pressure recovery is normal pressure (1 standard atmospheric pressure, i.e. 0.1MPa), timber continues to be immersed in retardant solution, carries out normal pressure dip treating, obtained normal pressure dipping timber, wherein, the normal pressure dip treating time is 30min.

3, drying treatment

Normal pressure is flooded timber under room temperature (15-30 DEG C), places 7d, then loft drier it is placed in, dry more than 6h at 103 DEG C, obtained flame-retardant impregnating timber, wherein the water content of flame-retardant impregnating timber is 10% (water ratio≤15% is all applicable to the present invention).

Putting 7d for ambient temperatare in the embodiment of the present invention to be described, timber is placed 5-10d and is all applicable to the present invention.

4, hot modification

4-1) flame-retardant impregnating timber is placed in high-temperature heat treatment proofing box (the permanent Science and Technology Ltd. in Shanghai one, PXR-9), heat temperature raising, raises the temperature to 150 DEG C with the temperature rise rate of 15 DEG C/min, keep 30min when temperature is 150 DEG C, carry out high-temperature hot modification;

Wherein: employing water vapor is that (placing water in proofing box, along with the temperature inside the box raises, moisture evaporation produces water vapor to shielding gas, plays the effect of protection shielding gas. Except placing water producing water vapor in proofing box, it is also possible to lead to into the shielding gas such as water vapor, nitrogen in case).

4-2) after isothermal holding 30min, stop heating, it is reduced to room temperature (15-30 DEG C) until Wood temperature and takes out afterwards;

4-3) timber being placed in constant temperature and humid test case, carry out conditioning, the water ratio regulating timber is 10%, obtained fire-retardant hot modified wood.

The hot modified wood of preparation adopts Electronic Speculum to scan, and observes the distribution of wood internal fire retardant, electron-microscope scanning Fig. 3.

Wood internal fire retardant distribution as can be seen from Figure 3: hot modified fire retardant adheres to wood cell wall with thin layer form, is close to as face contacts with wood internal, area coverage is big, and wood cell wall is without obvious bare area, and fire retardant is without obvious particle crystalline polamer. The fire retardant dipping timber describing the present invention can change fire retardant existing way in wood through overheated modification: fire retardant suspends by granule crystal or filling of reuniting is changed into stratiform combining form, greatly increase the bonding force between fire retardant and wood cell wall, impel and produce chemical bonds between the two. Thus, increase bonding force and the leach resistance of fire retardant and timber, meanwhile, fire retardant is uniformly distributed in wood cell wall and can give full play to fire retardation in burning, it is to increase the flame retardant effect of process timber.

Embodiment 3 prepares fire-retardant hot modified wood

1, modified flame-retardant agent solution is prepared

Modification nitrogen phosphorus fire retardant embodiment 1 prepared is dissolved in water, and stirring and dissolving is even, obtains modified flame-retardant agent solution, and the mass percent concentration of modified flame-retardant agent solution is 5%, by every 5g modification nitrogen phosphorus fire retardant solution 95g water, to obtain final product.

2, dip treating

2-1) vacuum impregnation process

Retardant solution is poured in the impregnating autoclave that quick growth poplar wood is housed, and timber is soaked completely, connect vacuum pump; Open vacuum pump to carry out vacuumizing process, make the vacuum tightness in tank reduce and remain-0.09MPa, under a reduced pressure timber is carried out vacuum impregnation process, obtained vacuum impregnation timber, wherein, timber is 1:3 with the ratio of the volume of retardant solution, and the treatment time is 20min;

2-2) normal pressure dip treating

Close vacuum pump, open vacuum pressed tank so that in tank, pressure recovery is normal pressure (1 standard atmospheric pressure, i.e. 0.1MPa), timber continues to be immersed in retardant solution, carries out normal pressure dip treating, obtained normal pressure dipping timber, wherein, the normal pressure dip treating time is 40min.

3, drying treatment

Normal pressure flooding timber and places 7d under room temperature (15-30 DEG C), be then placed in loft drier, dry more than 6h at 103 DEG C, obtained flame-retardant impregnating timber, wherein the water content of flame-retardant impregnating timber is 7%.

4, hot modification

4-1) flame-retardant impregnating timber is placed in high-temperature heat treatment proofing box, heat temperature raising, raises the temperature to 140 DEG C with the temperature rise rate of 20 DEG C/min, keep 20min when temperature is 140 DEG C, carry out high-temperature hot modification;

4-2) after isothermal holding 20min, stop heating, it is reduced to room temperature (15-30 DEG C) until Wood temperature and takes out afterwards;

Embodiment 4 prepares fire-retardant hot modified wood

1, modified flame-retardant agent solution is prepared

Modification nitrogen phosphorus fire retardant embodiment 1 prepared is dissolved in water, and stirring and dissolving is even, obtains modified flame-retardant agent solution, and the mass percent concentration of modified flame-retardant agent solution is 15%, by every 15g modification nitrogen phosphorus fire retardant solution 85g water, to obtain final product.

2, dip treating

2-1) vacuum impregnation process

Retardant solution is poured in the impregnating autoclave that quick growth poplar wood is housed, and timber is soaked completely, connect vacuum pump; Open vacuum pump to carry out vacuumizing process, make the vacuum tightness in tank reduce and remain-0.03MPa, under a reduced pressure timber is carried out vacuum impregnation process, obtained vacuum impregnation timber, wherein, timber is 1:3 with the ratio of the volume of retardant solution, and the treatment time is 40min;

2-2) normal pressure dip treating

Close vacuum pump, open vacuum pressed tank so that in tank, pressure recovery is normal pressure (1 standard atmospheric pressure, i.e. 0.1MPa), timber continues to be immersed in retardant solution, carries out normal pressure dip treating, obtained normal pressure dipping timber, wherein, the normal pressure dip treating time is 20min.

3, drying treatment

Normal pressure flooding timber and places 7d under room temperature (15-30 DEG C), be then placed in loft drier, dry more than 6h at 103 DEG C, obtained flame-retardant impregnating timber, wherein the water content of flame-retardant impregnating timber is 15%.

4, hot modification

4-1) flame-retardant impregnating timber is placed in high-temperature heat treatment proofing box, heat temperature raising, raises the temperature to 130 DEG C with the temperature rise rate of 10 DEG C/min, keep 40min when temperature is 130 DEG C, carry out high-temperature hot modification;

4-2) after isothermal holding 50min, stop heating, it is reduced to room temperature (15-30 DEG C) until Wood temperature and takes out afterwards;

4-3) timber being placed in constant temperature and humid test case, carry out conditioning, the water ratio regulating timber is 12%, obtained fire-retardant hot modified wood.

Reference examples 1

1, the timber identical with embodiment 2 is directly placed in loft drier by drying treatment, and at 103 DEG C, dry 6h is until the water content of timber is 10%.

2, hot modification

Except hot modification temperature is 220 DEG C, outside insulation 120min, all the other are identical with the hot modification of embodiment 2.

Reference examples 2

1, dip treating

Except using distilled water to replace retardant solution, all the other are identical with the dip treating of embodiment 2;

2, drying treatment

Identical with the step of the drying treatment of embodiment 2, treatment condition;

3, hot modification

Identical with the step of the hot modification of embodiment 2, treatment condition.

Reference examples 3

1, dip treating

2, drying treatment

3, hot modification

Except hot modification temperature is 200 DEG C, outside insulation 120min, all the other are identical with the hot modification of embodiment 2.

Reference examples 4

Except not carrying out hot modification, all the other are identical with embodiment 2.

The timber of preparation adopts Electronic Speculum to scan, and observes the distribution of wood internal fire retardant, and electron-microscope scanning figure is such as Fig. 4.

Fire retardant hangs attached in wood cell wall surface in wood internal major part with particulate state as can be seen from Figure 4, fire retardant and wood surface contact area are little, except fire-retardant particles, wood cell wall major part area is in naked state, describe fire retardant distributing homogeneity and associativity in wood cell wall poor, easily in use run off, thus lose or reduce flame retardant properties.

Test example 1 drug loading is tested

1, the quality (M before former material (quick growth poplar wood) dip treating of record embodiment 2-4, reference examples 1-4 is weighed respectively₀, g), volume (v, m³)。

2, respectively liquid more than wood surface after the dip treating of embodiment 2-4, reference examples 1-4 is dried, weigh immediately and the quality (M of record dip treating timber₁, g).

3, calculating timber carrying drug ratio according to formula (1), measurement result is as shown in table 1,

Drug loading=(M₁-M₀) c/v × 100% (1)

Wherein: M₁Quality after sample dipping, unit is gram (kg); M₀Quality before sample dipping, unit is gram (kg). C liquid quality fraction, %; V volume of sample, m³。

Test example 2 timber wet swollen property test

According to GB/T1934.2-2009 " Method for determination of the swelling of wood ", baking oven put into by hot modified wood and the former material sample embodiment 2-4, reference examples 1-4 prepared, is heated to 60 DEG C and keeps 4h at 60 DEG C; Then respectively wood sample dried according to GB " Method for determination of the moisture content of wood (GB/T1931-2009) " and weigh, measure respectively in the central position on sample each phase opposite wood sample absolutely dry time radial direction, string to and rift grain direction length (l₀), it is accurate to 0.001mm; Then, being 20 ± 2 DEG C by sample in temperature, when relative humidity is 65 ± 3%, moisture absorption is to dimensional stabilizing, in moisture absorption process, with 2-3 sample, measure a timber string to the change of size every 6h examination, when difference to twice measuring result is no more than 0.2mm, it is considered as size and reaches stable; Size (the l during moisture equilibrium of last test all samples_w), it is accurate to 0.001mm.

Sample from absolutely dry to moisture equilibrium time, radial or string to the line swollen rate that wets calculate by formula (2), be accurate to 0.1%.

a_w=(l_w-l₀)/l₀× 100% (2)

In formula:

a_wSample from from absolutely dry to radial during moisture equilibrium or string to linear wet swollen rate, %;

l_wDuring sample moisture equilibrium radial or string to length, unit is millimeter (mm) %;

l₀When sample is absolutely dry radial or string to length, unit is millimeter (mm) %;

Sample from absolutely dry to moisture equilibrium time, the volume swollen rate that wets calculates by formula (3), is accurate to 0.1%.

S=(v_w-v₀)/v₀× 100% (3)

In formula:

S sample wets swollen rate from from absolutely dry to volume during moisture equilibrium, %;

v_wVolume during sample moisture equilibrium, unit is cubic millimeter (mm³) %;

v₀Volume when sample is absolutely dry, unit is cubic millimeter (mm³) %;

Sample from absolutely dry to moisture equilibrium time, radial or string to anti-wet swollen coefficient calculate according to formula (4), be accurate to 0.1%.

ASE=(S_C-S_T)/S_C× 100% (4)

In formula:

The anti-wet swollen coefficient of ASE, %;

S_CThe volume of untreated material (i.e. former material) wets swollen rate, %;

S_TThe volume of process material wets swollen rate, %;

Wet the rising property test determination result of timber is as shown in table 1.

The drug loading of table 1 heat-treated wood, wet swelling rate test-results

Can learn by table 1:

1, the drug loading height of fire-retardant hot modified wood prepared by the embodiment of the present invention, reaches 35kg/m³Above, in the timber of preparation, flame retardant agent content reaches and is not less than 30kg/m³Standard, fire-retarding of wood performance is good.

2, the wet swelling rate of fire-retardant hot modified wood prepared by the embodiment of the present invention reduces, radial chord to anti-wet swollen coefficient reach 21%, more than 37% respectively, the radial swollen rate of moisture absorption is lower than 1.5-%; String lower than 1.7%, shows that high-temperature hot modification significantly improves the dimensional stability of fire-retardant pre-treatment timber to the swollen rate of moisture absorption, reduces the water absorbability of timber.

3, the fire-retardant hot modified wood that prepared by the embodiment of the present invention and (reference examples 1 compared with prior heat treatment, 220 DEG C of process 120min), thermal treatment temp significantly reduces, and heat treatment time obviously shortens, and can significantly reduce the production cost of fire-retardant hot modified wood.

Fire-retardant hot modified wood prepared by the inventive method is at lesser temps (140-150 DEG C) and can reach the effect improving wood dimensional stability in the short period (20-40min), and dimensional stability improves and can reach equal or higher than the effect of prior heat treatment timber.

4, the fire-retardant hot modified wood that prepared by the embodiment of the present invention with adopt water retting process after according to low-temperature heat treatment of the present invention (reference examples 2,150 DEG C of process 30min) compare, in treating processes, the chemical composition change in timber is faint, hydrophilic radical is if-OH is without obvious minimizing, modified wood dimensional stability compares material without raising, identical with the wet swelling rate of former material (radial, string to, volume); Anti-wet expansion factor (radial, string to) is 0;

Carrying out after processing with adopting water retting compared with high-temperature heat treatment (reference examples 3,200 DEG C process 120min), wood dimensional stability is improved to some extent, and radial anti-wet swollen coefficient reaches 15.8%; String reaches 37% to anti-wet swollen coefficient.

The inventive method prepares modification nitrogen phosphorus fire retardant (130-150 DEG C) short period of time (20-40min) interior catalysis timber hemicellulose dehydration carbonization at a lower temperature in fire-retardant hot modified wood process, hydrophilic radical such as-OH is made in timber to reduce, between fire retardant and timber, form chemical bonds, reduce hydroscopicity of wood energy, dimensional stability improves, radial anti-wet swollen coefficient reaches more than 20%, it is 36.8% to the maximum, string reaches more than 37% to anti-wet swollen coefficient, maximum reaches 51.9%.

5, the fire-retardant hot modified wood that prepared by the embodiment of the present invention is compared with only carrying out flame-retardant impregnating process (reference examples 4), owing to being mainly combined in the way of physics filling between fire retardant with timber, nitrogen phosphorus type flame retardant itself containing unreacted completely urea and in a large number hydrophilic radical such as-NH₂Deng, the relatively material increase of process material water absorbability, dimensional stability decline is radial, string is negative value to anti-wet swollen coefficient;

Fire-retardant hot modified wood prepared by the embodiment of the present invention is in hot modifying process, the fire retardant of aggregating state occurs to distribute under hot and humid environment again, with lumber fibre formed Chemical bond and catalysis Wood carbonization sloughs-OH, hydrophilic component in fire retardant and timber all reduces, and fire-retardant hot modified wood dimensional stability improves.

Test example 3 wood surface aberration is tested

1, the hot Modified Poplar that respectively prepared by Example 2-4 and reference examples 1-4, former material, as test specimen, are of a size of 50mm × 50mm × 20mm;

2, the color measurement method specified according to the international luminouslighting council (CIE) of Color Evaluation utilization, namely CIE standard colorimetric system measures three basic index (L* of timber, a* and b* value) color of heat-treated wood is carried out accurate quantification sign, and experimentally result carries out overall aberration (Δ E*) and visual physical parameter is analyzed;Sample measures to getting 3 points with radial two sides according to string, averages as final observed value.

Three of CIE (L*a*b*) standard chroma characterization system main basic index L*, a*, b*, wherein

L*: lightness, completely white object is considered as 100, and completely black object is considered as 0;

A*: red green axle chromaticity index, is just being worth more big expression color and is more being partial to redness, and green is more partial in the more big expression of negative value;

B*: champac axle chromaticity index, is just being worth more big expression color and is more being partial to yellow, and blueness is more partial in the more big expression of negative value.

By the change of these three basic indexs according to formula (5), (6), derive and draw aberration Δ E* and saturation ratio C*.

Δ E*=(△ L*²+△a*²+△b*²)^l/2(5)

C*=(a*²+b*²)^l/2(6)

In formula:

The red green axle chromaticity index value of a*;

B* champac axle chromaticity index value;

Δ L* lightness changing value;

The red green axle chromaticity index variation value of Δ a*;

Δ b* champac axle chromaticity index variation value;

Adopting the full-automatic colour examining colour-difference-metre of TC-PIIG type (Beijing Optical Instrument Factory) to measure heat-treated wood color and visual physical parameter, the mean value of measurement result is as shown in table 2.

Test example 4 wood surface hardness test

Hot modified wood that respectively prepared by Example 2-4, reference examples 1-4 and former material, as test specimen, are of a size of 50mm × 50mm × 20mm; Shore durometer TH210 is utilized surface of test piece hardness to be tested.

Vertical pressing in sample surface under test power effect, when pressing foot surface to fit completely with specimen surface, pressure needle tip presses foot plane to have certain extrusion L relatively. Characterize the size of shore hardness HD (HD=100-L) with the size of L value, L value is more big, represents that shore hardness is more low, otherwise hardness is more high. Measurement result is as shown in table 2.

The surface hardness of table 2 reference examples and embodiment test specimen and color

Numbering	Surface hardness	L*	a*	b*	ΔE*	C*
							Embodiment 2	51.14	52.06	11.26	22.45	33.65	25.12
Embodiment 3	51.36	53.94	10.35	24.44	29.45	26.54
							Embodiment 4	53.74	45.725	10.09	21.06	41.9	23.35 13 -->
Reference examples 1	42.26	47.18	9.87	20.8	36	23.02
							Reference examples 2	51.07	82.43	3.45	18.38	4.99	18.7
Reference examples 3	47.72	62.27	9.04	24.69	24.09	26.29
							Reference examples 4	53.41	82.43	3.44	18.39	2.76	18.71
Material	51.49	86.2	2.35	15.31	-	15.49

As shown in Table 2:

1, the hot modified wood that prepared by reference examples 1, reference examples 3 processes 120min respectively at 200 DEG C, 220 DEG C, surface color is compared material brightness value L* and is reduced, red green axle chromaticity index a* and champac axle chromaticity index value b* increases, saturation ratio C* is increased to 23.02-26.29 by 15.49, amplification reaches 32%-41%, and wood surface decoration property improves; The hot modified wood of reference examples 2 processes 30min at 150 DEG C, and wood surface color, without considerable change, can not increase the surface decoration effect of modifier; Prepared by reference examples 4 only does flame-retardant impregnating process timber, and colorimetric parameter, without considerable change, can not increase the surface decoration effect of modifier.

2, the fire-retardant hot modified wood that prepared by the inventive method decomposes the dehydration such as the catalysis lumber fibre that produces phosphoric acid due to the lower ammonium polyphosphate of the polymerization degree in fire retardant, ammonium phosphate etc. at 130-150 DEG C, colour brilliance decline can be reached equally, and the effect that red green axle chromaticity index value a*, champac axle chromaticity index value b* increase, saturation ratio C* compares material about increases by 38%; Red green axle chromaticity index a*, champac axle chromaticity index value b* are relatively big, and saturation ratio is relatively big, and material look is more tending towards brown, more close with some precious timber color, illustrate that embodiment of the present invention process test specimen can possess good color decorate properties.

3, the heat-treated wood surface hardness that prepared by reference examples 1 and reference examples 3 relatively material decline more than 7.32%, under hot and humid environment is described, process can cause wood surface degradation, the surface working application in further impact process material later stage.And fire-retardant hot modified wood prepared by the inventive method is compared material and is declined phenomenon without surface hardness.

Test example 6 flame retardant test

Heat-treated wood that respectively prepared by Example 2-4, reference examples 1-4 and former material Yang Mu are as test specimen (being of a size of 100mm × 100mm × 20mm), the method specified according to ISO5660-1:2002 " release of Reaction to fire experiment hot, cigarette output and mass loss rate first part: heat release rate (Cone calorimeter) ", utilizes FTT0242 type cone calorimetry to carry out fire retardancy test.

Before test, according to ISO554 by fire-retardant Yang Mu test specimen temperature 23 ± 2 DEG C, when relative humidity 50 ± 5%, maintenance is to constant mass (water ratio is 9%). When, in twice weighing of 24h of being separated by, the difference of the quality of sample is no more than 0.1% or the 0.1g (peek is worth the maximum) of sample mass, then think and reach constant-quality.

The flame retardant properties measurement result of heat-treated wood is as shown in table 3; The heat release rate HRR curve of heat-treated wood prepared by embodiment 2-4, reference examples 1-4 and former material is as shown in Figure 1; Flue gas release performance measurement result is as shown in table 4; The total smoke release TSR curve of heat-treated wood prepared by embodiment 2-4, reference examples 1-4 and former material is as shown in Figure 2.

The flammability test results of table 3 heat-treated wood test specimen

Note: in table, HRR represents evenly heat rate of release, PHRR1 represents low temperature peak heat release, PHRR2 represents high temperature peak heat release, TPHRR1 represents the time that low temperature peak heat release occurs, TPHRR2 represents the time that high temperature peak heat release occurs, THR represents burning total heat release, and RM represents burning charcoal residual quantity.

As shown in Table 3,

1, the fire-retardant hot modified wood that prepared by the inventive method is compared with heat-treated wood prepared by reference examples and material, and total heat release rate HRR and total heat release THR obviously reduces, and carbon left RM improves, and flame retardant effect obviously strengthens.

2, the fire-retardant hot modified wood that prepared by the inventive method is compared with the hot modified wood without fire-retardant composition, and total heat release rate HRR and total heat release THR obviously reduces, and carbon left RM improves, and flame retardant effect obviously strengthens, wherein:

A) total heat release rate HRR about reduces by 60%, and total heat release THR about reduces by 55%, and carbon left RM improves about 92%, illustrates that fire-retardant hot modified wood prepared by the present invention is compared with general high-temperature thermal treatment timber, and flame retardant properties increases substantially;

B) heat release rate peak value PHRR₁Reduce about 66%, PHRR₂Reduce about 54%, illustrate that fire-retardant hot modified wood burning severe degree obviously declines; The time TPHRR that heat release rate peak value occurs₁、TPHRR₂About increasing 7s-16s, 79s-135s respectively, illustrate that the violent combustion phases of fire-retardant hot modified wood is postponed, combustion completion performance improves. Once presence of fire, fire-retardant hot modified wood ignition energy is withdrawn for personnel and fire-fighting work provides valuable time;

3, fire-retardant hot modified wood prepared by the inventive method is compared with only carrying out flame-retardant impregnating process preparation method timber, total heat release rate HRR and total heat release THR improves 23% respectively, 22%, illustrate compared with common wood treated with fire retardants, hot modification can improve fire-retarding of wood performance further, its reason may be on the one hand fire retardant in hot modifying process with timber generation chemical reaction, more even respectively at wood internal, on the other hand, fire retardant is the carbonization of catalysis timber dewatering in hot modifying process, once presence of fire, the time that fire-retardant hot modified wood performance intercepts layer of charcoal shortens, timber combustion heat release habituation (such as Fig. 1),

4, the fire-retardant hot modified wood that prepared by the inventive method is compared with material, and total heat release rate HRR reduces 54-62%, and total heat release THR reduces 25-46%, and carbon left RM increases 53-72%; Heat release rate peak value reduces, and burning severe degree declines to a great extent, the time TPHRR that particularly heat release rate peak value occurs₂Increasing 125-170s respectively, illustrate that the stage that burning degree is the most violent postpones, overall flame performance improves.

The flue gas release comparing result of table 4 heat-treated wood test specimen

Note: COY represents average carbon monoxide burst size, and CO2Y represents average carbon dioxide releasing amount, and TSP represents total cigarette output, and SEA (600) represents average specific delustring area in burning 600s. The smoke which that the material of unit mass produces is consumed under experiment condition.

As can be seen from Table 4:

1, the fire-retardant hot modified wood that prepared by the inventive method due to fire retardant effect, timber burn insufficient degree improve, average CO₂Burst size reduces, and timber incomplete combustion produces more CO, but, except personal security is threatened by the toxic gases such as CO in fire, combustion product gases and solid particulate matter easily hinder breathing, block vision, obstruction trapped personnel is withdrawn, and is another big hidden danger of fire safety evaluating.

2, the direction impelling the thermal decomposition of wood to generate charcoal to this due to fire retardant in the fire-retardant hot modified wood that prepared by the inventive method carries out, and is conducive to reducing smoke delivery, and its total cigarette output of burning significantly reduces.

3, by Fig. 2 (timber burning total smoke release TSR curve) it may be seen that fire-retardant hot modified wood prepared by the inventive method is burning in whole process, smoke delivery is significantly lower than reference examples, adds the combustion safety of material.

4, under SEA (600s) represents experiment condition, burning initial stage (600s) consumes the smoke which that the material of unit mass produces, and fire-retardant hot modified wood prepared by the embodiment of the present invention compares as a rule and material is all greatly improved.

To sum up, the timber that preparation is combined in the fire-retardant and high-temperature steam thermal treatment of the present invention had both had good material look, dimensional stability, has again the performance of flame-retardant smoke inhibition, reaches and improve materials'use security.

Claims

1. a preparation method for fire-retardant hot modified wood, is characterized in that, comprises and being heat-treated by the timber after dip treating.

2. preparation method as claimed in claim 1, it is characterised in that, described dip treating comprises timber successively under a reduced pressure, soak under atmospheric pressure state.

3. preparation method as claimed in claim 1 or 2, it is characterised in that, the vacuum tightness < 0MPa of described decompression state.

4. preparation method as claimed in claim 1 or 2, it is characterised in that, described heat treated temperature is 130-160 DEG C.

5. the preparation method of a fire-retardant hot modified wood, it is characterised in that, comprise the step that following order carries out:

4) flame-retardant impregnating timber is heat-treated.

6. preparation method as claimed in claim 5, is characterized in that, step 1) described in fire retardant select nitrogen phosphorus fire retardant, modification nitrogen phosphorus fire retardant.

7. preparation method as described in claim 5 or 6, is characterized in that, step 1) described in vacuum tightness < 0MPa in vacuum impregnation treating processes.

8. preparation method as described in claim 5 or 6, is characterized in that, step 4) described in the temperature of heat_treated wood be 130-160 DEG C.

9. preparation method as described in claim 5 or 6, it is characterized in that, step 4) described in the hot modification of timber be that the temperature of timber is increased to 130-160 DEG C by the temperature rise rate with 5-20 DEG C/min, keep 20-50min when temperature is 130-160 DEG C, it is preferable to 30min.

10. a fire-retardant hot modified wood, is characterized in that, is prepared from according to method as described in as arbitrary in claim 1-9.