WO2010066066A1

WO2010066066A1 - Wood preservative and method for wood preservation

Info

Publication number: WO2010066066A1
Application number: PCT/CN2008/001993
Authority: WO
Inventors: 曹金珍; 余丽萍
Original assignee: 北京林业大学
Priority date: 2008-12-11
Filing date: 2008-12-11
Publication date: 2010-06-17
Also published as: CN102066062A; CN102066062B

Abstract

A boron based wood preservative composite comprises the materials of sodium fluoroborate and didecyl dimethyl ammonium chloride (DDAC). The said materials penetrate through the wood ready for preservation with the application of vacuum and pressure, and then react chemically to produce water-insoluble boron composition. A method for wood preservation treatment is also disclosed.

Description

Wood preservative and wood anticorrosion treatment method

The invention relates to a preservative and a preparation method thereof, in particular to a preservative containing boron element and a preparation method thereof. Background technique

There are many kinds of chemical agents for wood anti-corrosion, but with the improvement of people's environmental awareness, some wood preservatives that are harmful to the environment and human health (such as Chromium arsenate, CCA, sodium pentachlorophenol, coal tar, etc.) Use is gradually restricted or prohibited.

Boron compounds are a class of insecticides with excellent properties. These compounds have been studied as wood preservatives earlier. Numerous studies have shown that boron compounds (abbreviated as borax, SBX) have good resistance to various microorganisms that invade wood, have a broad spectrum of antibacterial properties and high bactericidal properties, and wood samples treated with boride are There are certain improvements in flame retardancy and dimensional stability. In addition, as a kind of excellent insecticidal sterilizing agent, boride not only has the advantages of low price, abundant source, low toxicity to humans and animals, low environmental damage, low influence on mechanical strength, easy coloring, painting and gluing, etc. The wood preservative has good permeability in wood, excellent infusion effect, and does not affect the color and texture of the wood itself, so the boride is widely used for wood preservation.

However, since the boride is a water-soluble compound, if the boride-treated wood is wetted (such as rain, water, etc.) or in contact with the soil, the boron in the wood is gradually lost, and its antiseptic/ The pest control effect will gradually decrease or even be completely lost, which greatly limits the application range of such wood preservatives. Therefore, most of the wood treated with boron-based preservatives can only be used indoors, but not outdoors.

At present, in order to overcome the shortcomings of boron-based preservatives, researchers at home and abroad have done a lot of research work. Studies have shown that some other compounds can be added to this type of preservative to form a composite boron-based wood preservative to enhance its Corrosion resistance and boron resistance; a variety of additives can also be used to help boron be fixed on wood. These additives are mostly polymer monomers or polymers such as ethylene monomer, methyl methacrylate, poly Ethylene glycol, etc.; also use some natural substances such as protein and tannin; also use simple physical methods, only the surface of the treatment material is coated with varnish, alkyd paint and other waterproofing agents; In addition, there are different application of anti-corrosion treatment The process is treated by a gas phase boron process to treat the wood. Although these methods can reduce the loss of boron in the treated materials to varying degrees, the effect of these methods is not particularly obvious, and the resistance to boron can only be increased to about 30%.

At present, many metal modified boron-based composite preservatives and metal-free boron-based composite preservatives have been studied.

Metal-modified boron-based composite preservatives are currently mainly studied by copper azole, metaboric acid and boric acid metal compounds. Among them, wood treated with copper azole preservative, due to the interaction of copper and boron in the preservative, various elements form unstable fixation in the wood, and the boron loss rate is high. In addition, there is also a part of copper from the wood. Loss, there is a certain pollution to the environment. The metaboric acid and the boric acid metal compound are a kind of water-insoluble compound, which is structurally stable and hardly soluble in water, so it is difficult to use water or the like as a medium to enter the interior of the wood. At present, the surface of the wood is mainly treated by spraying, and the surface resistance of the wood is improved. Corrosive, but because the surface of the wood is only treated, the anti-corrosion effect is not durable.

Metal-free boron-based composite preservatives are currently studied mainly with disodium octaborate tetrahydrate (DOT) boron-based wood preservatives, boric acid and sterol amine complex boron-based preservatives, trimethyl borate and phenylimidazoles. (fipronil) composite wood preservatives, etc. DOT wood preservatives have strong termite resistance to subterranean termites, and have relatively low resistance to fungi. Therefore, the application of single components is relatively small, mainly as an additive to other preservatives, which can significantly improve the resistance of preservatives. Termites, but their active ingredients are less resistant to leaching, and almost 100% of DOT will be lost from the treated material. Summary of the invention

SUMMARY OF THE INVENTION An object of the present invention is to provide a wood preservative and a wood preservative treatment method in view of the problems of the prior art. The component of the composite boron-based wood preservative of the present invention is infiltrated into the interior of the wood to be treated by vacuum pressure infusion, and then chemically reacted to form a boron-insoluble compound which is hardly soluble in water, so that the preservative in the wood to be preserved The loss rate is low, the anti-leak performance is significantly improved, and the anti-corrosion effect is significantly enhanced.

In order to achieve the object of the present invention, an aspect of the present invention provides a wood preservative comprising sodium fluoroborate and dimercaptodimethylammonium chloride.

Wherein, the molar ratio of sodium fluoroborate to dimercaptodimethylammonium chloride is 1: 0.8-2, preferably 1: 1-1.5. Another aspect of the invention provides a method for preservative treatment of wood, comprising the steps of:

1) preparing a sodium fluoroborate solution and a dimercaptodimethylammonium chloride solution;

2) completely immersing the wood to be pretreated in sodium fluoroborate solution, first vacuuming, then pressurizing the wood to absorb the sodium fluoroborate solution, then depressurizing, removing the wood and drying it;

3) completely immersing the dried wood in the dimercaptodimethylammonium chloride solution, first performing vacuum treatment, and then performing a pressure treatment to cause the wood to absorb the dimercaptodimethylammonium chloride solution, and then Depressurize and remove the wood;

4) Dry the wood.

During the drying of the wood, sodium fluoroborate and dimercaptodimethylphosphonium chloride in the interior of the wood react to form a boron-containing compound that is poorly soluble in water.

Another aspect of the invention provides a method for preservative treatment of wood, comprising the steps of:

1) preparing a sodium fluoroborate solution and a dimercaptodimethylammonium chloride solution; 2) completely immersing the wood to be pretreated in the dimercaptodimethylammonium chloride solution, first vacuuming, and then pressurizing the wood to absorb the dimercaptodimethylammonium chloride solution, and then Depressurize, remove the wood and dry it;

3) completely immersing the dried wood in the sodium fluoroborate solution, first performing vacuum treatment, and then performing a pressure treatment to cause the wood to absorb the sodium fluoroborate solution, and then depressurizing, and taking out the wood;

4) Dry the wood.

During the drying process of the wood, sodium fluoroborate and dimercaptodimethylammonium chloride in the interior of the wood react to form a boron-containing compound that is poorly soluble in water.

Another aspect of the invention provides a method for preserving wood, including the steps -

2) Put the wood to be preserved into a vacuum pressurized tank, first evacuate it, then introduce the sodium fluoroborate solution, then pressurize the wood to absorb the sodium fluoroborate solution, then relieve the pressure, remove the wood and It is dried;

3) Put the dried wood into a vacuum pressurized tank, first evacuate it, then introduce the dimercaptodimethylammonium chloride solution, and then pressurize the wood to absorb the dimercaptodimethyl chloride. Ammonium solution, then relieve pressure, remove the wood;

4) Dry the wood.

During the drying of the wood, sodium fluoroborate and dimercaptodimethylammonium chloride in the interior of the wood react to form a boron-containing compound that is poorly soluble in water.

Another aspect of the invention provides a method for preserving wood, comprising the steps of:

2) Put the wood to be treated into a vacuum pressurized tank, first evacuate it, then introduce the dimercaptodimethylammonium chloride solution, and then pressurize the wood to absorb the dimercaptodimethyl chloride. The ammonium solution is then depressurized, the wood is removed and dried;

3) Put the dried wood into a vacuum pressurized tank, first evacuate it, then introduce a sodium fluoroborate solution, and then pressurize the wood to absorb the sodium fluoroborate solution, and then relieve the pressure to remove the wood;

4) Thousands of dry wood.

The resulting boron-containing compound is hardly soluble in water and is not easily lost, and the prepared wood has high resistance to leaching and high retention of boron. Wherein the mass percentage concentration of the sodium fluoroborate solution described in the step 1) is 0.1-2%, preferably 0.3-1%; the mass percentage concentration of the dimercaptodimethyl chlorinated hinge solution is sodium fluoroborate 3-6 times, preferably 4-5 times the concentration of the solution mass percentage (for example: when the mass percentage concentration of the sodium fluoroborate solution is 0.1%, the mass percentage concentration of the DDAC solution is 0.3-0.6%; when the sodium fluoroborate solution When the mass percentage concentration is 1%, the mass percentage concentration of the DDAC solution is 3-6%; when the mass percentage concentration of the sodium fluoroborate solution is 2%, the mass percentage concentration of the DDAC solution is 6-12%).

Wherein, the relative vacuum degree of the vacuum treatment in the step 2) and the step 3) is -0.05 to -0.09 MPa, preferably -0.07 to -0.09 MPa, and the treatment time is 20-60 min, preferably 30-50 min; The absolute pressure is from 1.0 to 4.0 MPa, preferably from 1.5 to 3 MPa, and the treatment is from 30 to 240 minutes, preferably from 60 to 180 minutes.

Wherein, the moisture content of the wood after drying in step 2) is less than 25%, preferably 10-20%; the moisture content of the wood after drying in step 4) is less than 15%, preferably 8-12%; The molar ratio of sodium fluoroborate to dimercaptodimethyl chloride hinge in the interior of the wood is 1: 0.8-2, preferably 1:1 to 1.5.

In particular, the drying temperatures described in steps 2) and 4) are 30-60 Torr and the dry relative humidity is 40-70%.

Still another aspect of the present invention provides a preservative wood which is prepared by the above-described method of preservative treatment of wood.

The invention has the following advantages:

The method for preserving the wood of the invention is that the composition of the composite boron-based preservative is sequentially infiltrated into the wood to be treated by using two vacuum pressure infusion treatments, and the chemical reaction of each reaction component infiltrated into the wood occurs in the wood. A boron-insoluble compound that is poorly soluble in water is formed, thereby improving the resistance of boron in the wood. Therefore, the loss rate of the preservative in the wood treated with the antiseptic treatment is low, and the drug loading of the B ₂ 0 ₃ in the preservative treated wood reaches 0.2-5.1 kg/m ³ , and the retention rate of boron is high, reaching 75. -100%.

The anti-corrosion wood of the invention has strong corrosion resistance and remarkable anti-corrosion effect, and meets the strong corrosion resistance specified in the National Standard GB/T 13942.1-1992 "Laboratory Test Method for Natural Corrosion Resistance of Wood by Wood Natural Durability Test Method". Level requirements. detailed description

In order to better understand the technical features of the present invention, the present invention will be further described below in conjunction with specific embodiments. It should be noted that the embodiments are not intended to limit the scope of the invention.

The wood to be treated with anti-corrosion treatment is selected from Chinese fir sapwood (C-inghamia lanceolate), collected in Sichuan Honglai Forest Farm, with an average air dry density of 355kg/m ³ ; the dimensions are 3000mm (longitudinal) x95mm (chord direction) x28mm (diameter) To) the wood. Example 1

1, the preparation of the solution

The sodium fluoroborate is dissolved in water, and a solution having a mass percentage of 1% is used; the dimercaptodimethylammonium chloride (DDAC) is dissolved in water, and a solution having a mass percentage of 5% is used.

2, vacuum pressure infusion treatment of wood

1) Sodium fluoroborate treated wood

Put the wood into the vacuum pressure tank, connect the vacuum pump and the pressurizing equipment (ie, turn off the pressure equipment when the vacuum pump is started to vacuum; turn off the vacuum pump when the pressure equipment is turned on).

The vacuum pump is turned on for vacuuming, so that the relative vacuum in the vacuum pressurized tank is -0.09 MPa. After 60 minutes, the vacuum pump is turned off, and the sodium fluoroborate solution having a mass percentage of 1% is introduced until the relative vacuum in the vacuum pressurized tank is reached. Degree is OMPa;

The pressurizing device (hydraulic pump) is turned on, and the sodium fluoroborate solution is continuously supplied into the vacuum pressurized tank to pressurize the wood. The relative pressure in the vacuum pressurized tank was brought to 1.5 MPa. After maintaining the pressure for 180 minutes, open the drain valve and slowly discharge the sodium fluoroborate solution, relieve the pressure, and take out the wood treated with the sodium fluoroborate solution. The drug loading of the sodium fluoroborate in the treated material (loading amount = ( M2-M1) xCfW; where Ml: weight before wood treatment; M2: weight after wood treatment; C: solution concentration; V: wood volume) is 7.2 kg/m ³ .

2) Wood drying once

The wood was dried to a moisture content of 15% at a temperature of 45 ° C and a relative humidity of 55%.

3) DD AC treated wood

The dried wood is placed in a vacuum pressurized tank, and the vacuum pump is turned on for vacuum treatment, so that the relative vacuum in the vacuum pressurized tank is -0.09 MPa, and the vacuum pump is turned off after 60 minutes, and the mass concentration is 5%. DDAC solution, until the relative vacuum in the vacuum pressurized tank is OMPa;

After starting the pressurization equipment, the DDAC solution is continuously introduced into the vacuum pressure tank, and the wood block is pressurized. The relative pressure in the vacuum pressurized tank was brought to 1.5 MPa. After maintaining the pressure for 180 min, the snoring drain valve slowly drained the DDAC solution, relieved the pressure, and took out the wood treated with the DDAC solution. The drug loading of the DDAC in the treated material was 35.5 kg/m ³ .

4) Secondary drying and synthesis of wood

The wood is dried to a moisture content of 9% at a temperature of 45 ° C and a relative humidity of 55%. At the same time, sodium fluoroborate and DDAC in the wood react to form a boron-insoluble compound which is poorly soluble in water, wherein The molar ratio of sodium fluoroborate to DDAC in the composite boron-based preservative is 1:1.5. Example 2

Except that the mass percentage concentration of the sodium fluoroborate solution is 0.3%; the mass concentration of the DDAC solution is 1.2%; the relative vacuum of the vacuum treatment of the sodium fluoroborate solution and the DDAC solution treatment step is -0.05 MPa, vacuum The treatment time is 50 min; the relative pressure of the pressure treatment is 3 MPa, the pressure treatment time is 90 min, the drug loading of sodium fluoroborate in the treated material is about ^3.1 kg/m ³ , and the drug loading of DDAC is about 10.2 kg/m. ³ ; The same procedure as in Example 1 except that the molar ratio of sodium fluoroborate to DDAC in the composite boron-based preservative in the secondary drying and synthesis reaction step of the wood was 1:1. Example 3

1, the preparation of the solution

The sodium fluoroborate is dissolved in water, and a solution having a mass percentage of 0.1% is used; the dimercaptodimethylphosphonium chloride (DDAC) is dissolved in water to prepare a solution having a mass percentage of 0.6%.

2, vacuum pressure infusion treatment of wood

1) DDAC handles wood

Place the wood in a vacuum pressurized tank, connect the vacuum pump and the pressurizing equipment (ie, turn off the pressurizing device when the vacuum pump is started to vacuum; turn off the vacuum pump when the pressurizing device is turned on).

The vacuum pump is turned on for vacuuming, so that the relative vacuum in the vacuum pressurized tank is -0.07 MPa. After 30 minutes, the vacuum pump is turned off, and the DDAC solution having a mass percentage of 0.6% is introduced until the relative vacuum in the vacuum pressurized tank is OMPa;

Turn on the pressurizing device and continue to introduce the DDAC solution into the vacuum pressurized tank to pressurize the wood. The relative pressure in the vacuum pressurized tank was brought to 4 MPa. After maintaining this pressure for 30 min, open the drain valve to slowly remove the DDAC solution, relieve the pressure, and remove the wood treated with the DDAC solution. The DDAC charge in the treated material is 3.9 kg/m.

2) Wood drying once

The wood was dried to a moisture content of 20% under the conditions of a temperature of 45 ° C and a relative humidity of 55%.

3) Sodium fluoroborate treated wood

The dried wood is placed in a vacuum pressurized tank, and the vacuum pump is turned on for vacuum treatment, so that the relative vacuum in the vacuum pressurized tank is -0.07 MPa, and the vacuum pump is turned off after 30 minutes, and the mass percentage concentration is 0.1%. Sodium fluoroborate solution, until the relative vacuum in the vacuum pressurized tank is OMPa;

The pressurizing device is turned on, and the sodium fluoroborate solution is continuously introduced into the vacuum pressurized tank to pressurize the wooden block. Make true The relative pressure in the empty pressurized tank reached 4 MPa. After maintaining the pressure for 30 minutes, the liquid leaching solution was slowly removed, the sodium fluoroborate solution was slowly removed, the pressure was released, and the wood treated with the sodium fluoroborate solution was taken out. The drug loading of the sodium fluoroborate in the treated material was 0.6 kg/m ^{3 .} .

4) Secondary drying and synthesis of wood

The wood is placed at a temperature of 30 ° C and a relative humidity of 40%, and dried to a moisture content of 12%. At the same time, sodium fluoroborate and DDAC in the wood react to form a boron-insoluble compound which is poorly soluble in water, wherein The molar ratio of sodium fluoroborate to DDAC in the composite boron-based preservative is 1:2. Example 4

Except that the mass percentage concentration of sodium fluoroborate solution is 2%; the mass concentration of DDAC solution is 6%; the relative vacuum of DDAC treated wood step and sodium fluoroborate treated wood step is -0.09MPa, vacuum processing time 20min; the relative pressure of the pressure treatment is lMPa, the pressure treatment time is 240min, the drug loading of sodium fluoroborate in the treated material is 15.3kg/m ³ , and the drug loading of DDAC is 40.3kg/m ³ _; The secondary drying temperature is 60 °C, the relative humidity is 70%, and the wood moisture content after drying is 10%. The secondary boron-based preservative in the wood secondary drying and synthesis reaction step is sodium fluoroborate and DDAC. The molar ratio was 1:0.8, and the rest was the same as in Example 3. Example 5

1, the preparation of the solution

2, vacuum pressure infusion treatment of wood

1) Sodium fluoroborate treated wood

The wood is placed in a can of a vacuum pressurized tank containing a 1% by weight sodium fluoroborate solution, and immersed in a sodium fluoroborate solution, and the vacuum pump and the pressurizing device are connected (ie, when the vacuum pump is started to evacuate) Turn off the pressurizing device; turn off the vacuum pump when starting the pressurizing device.)

The vacuum pump is turned on for vacuuming, so that the relative vacuum in the vacuum pressurized tank is -0.09 MPa, and the vacuum pump is turned off after 60 minutes, and the exhaust valve is opened until the relative vacuum in the vacuum pressurized tank is OMPa;

The pressurizing device was turned on, and air or nitrogen gas was introduced into the vacuum pressurized tank to pressurize the wood so that the relative pressure in the vacuum pressurized tank reached 1.5 MPa. After maintaining the pressure for 180 min, the exhaust valve was opened to slowly discharge air or nitrogen, the pressure was released, and the wood treated with the sodium fluoroborate solution was taken out, and the drug loading of the sodium fluoroborate in the treated material was 5.5 kg/m ³ . 2) Wood drying once

3) DDAC handles wood

The dried wood is placed in a canister in a vacuum pressurized tank containing a DDAC solution of 5% by mass, and immersed in a DDAC solution, and the vacuum pump is turned on for vacuuming to make the vacuum pressurized tank The relative vacuum is -0.09MPa, after 60min is kept, the vacuum pump is turned off, and the exhaust valve is opened until the relative vacuum in the vacuum pressurized tank is OMPa;

The pressurizing device was turned on, and air or nitrogen gas was introduced into the vacuum pressurized tank to pressurize the wood so that the relative pressure in the vacuum pressurized tank reached 1.5 MPa. After maintaining the pressure for 180 min, the exhaust valve was opened to slowly discharge air or nitrogen, the pressure was released, and the wood treated with the DDAC solution was taken out. The drug loading of the DDAC in the treated material was 27.2 kg/m ^{3 .}

4) Secondary drying and synthesis of wood

The wood is placed at a temperature of 45 ° C and a relative humidity of 55%, and dried to a moisture content of 9%. At the same time, sodium fluoroborate and DDAC in the wood react to form a boron-insoluble compound which is poorly soluble in water, wherein The molar ratio of sodium fluoroborate to DDAC in the composite boron-based preservative is 1:1.5. Example 6

Except that the concentration of sodium fluoroborate solution is 0.3%; the mass concentration of DDAC solution is 1.2%; the relative vacuum of vacuum treatment during the process of sodium fluoroborate treatment and DDAC treatment is -0.05MPa, vacuum treatment time 50min; the relative pressure of the pressure treatment is 3MPa, the pressure treatment time is 50min; the drug loading of sodium fluoroborate in the treated material is 3.7kg/m ³ , and the drug loading of DDAC is 12.2kg/m ³ _; In the sub-drying and synthesis reaction steps, the molar ratio of sodium fluoroborate to DDAC in the composite boron-based preservative was 1:1, and the rest was the same as in Example 5. Example 7

1, the preparation of the solution

Sodium fluoroborate is dissolved in water, and a solution having a mass percentage of 0.1% is used; a solution of dimercaptodimethylammonium chloride (DDAC) dissolved in water is added to prepare a solution having a mass percentage of 0.6%.

2, vacuum pressure infusion treatment of wood

1) DDAC handles wood

The wood is placed in a can of a vacuum pressurized tank filled with a DDAC solution of 0.6% by mass, and immersed in a DDAC solution, and the vacuum pump and the pressurizing device are connected (ie, the vacuum pump is turned off when the vacuum pump is started). ; Turn off the vacuum pump when turning on the pressurizing device). Open the vacuum pump for vacuum treatment, so that the relative vacuum in the vacuum pressure tank is -0.07MPa, after 30min, turn off the vacuum pump, and open the exhaust valve until the relative vacuum in the vacuum pressure tank is OMPa;

The pressure device is pressurized, and air or nitrogen is introduced into the vacuum pressure tank to pressurize the wood so that the relative pressure in the vacuum pressure tank reaches 4 MPa. After maintaining 30 rnin under this pressure state, the exhaust valve was opened to slowly discharge air or nitrogen, the pressure was released, and the wood treated with the DDAC solution was taken out, and the drug loading of DDAC in the treated material was 3.9 kg/m ³ .

2) Wood drying once

The wood was dried to a moisture content of 12% at a temperature of 30 ° C and a relative humidity of 40%.

3) Sodium fluoroborate treated wood

The dried wood is placed in a canister in a vacuum pressurized tank containing a 0.1% by weight sodium fluoroborate solution, and immersed in a sodium fluoroborate solution, and the vacuum pump is turned on for vacuum treatment to add vacuum. The relative vacuum in the pressure tank is -0.07MPa, after 30min, the vacuum pump is turned off, and the exhaust gas is opened at the same time until the relative vacuum in the vacuum pressure tank is OMPa;

Pressurize the pressurizing device, and introduce air or nitrogen into the vacuum pressurized tank to pressurize the wood so that the relative pressure in the vacuum pressurized tank reaches 4 MPa. After maintaining the pressure for 30 minutes, open the exhaust gas and slowly discharge the air or nitrogen, relieve the pressure, and take out the wood treated with the sodium fluoroborate solution. The drug loading of the sodium fluoroborate in the treated material is 0.6 kg/m.

4) Secondary drying and synthesis of wood

The wood is dried to a moisture content of 12% at a temperature of 30 ° C and a relative humidity of 40%. At the same time, sodium fluoroborate and DDAC in the wood react to form a boron-insoluble compound which is poorly soluble in water, wherein the composite The molar ratio of sodium fluoroborate to DDAC in the boron-based preservative is 1:2. Example 8

Except that the concentration of sodium fluoroborate solution is 2%; the mass concentration of DDAC solution is 6%; the relative vacuum of vacuum treatment during DDAC treatment of wood and sodium fluoroborate is -0.09MPa, vacuum treatment time is 20min; relative pressure of the pressurized treatment is IMPa, pressure treatment time is 240min; drug loading sodium fluoroborate treatment material as 16.0kg / m ^3, DDAC drug loading was 42.1kg / m ^_3; primary timber The drying temperature in the secondary drying process is 60 °C, the relative humidity is 70%; the moisture content of the wood after drying is 10%; the sodium fluoroborate in the composite boron-based preservative in the secondary drying and synthesis reaction steps of the wood The same as Example 7 except that the molar ratio to DDAC was 1:0.8. Comparative Example 1 The rest was identical to Example 1 except that the wood was subjected to vacuum pressurization without using a DDAC solution. Comparative Example 2

The remainder was identical to that of Example 2 except that the wood was subjected to vacuum pressurization without using the DDAC solution. Comparative Example 3

The rest was the same as in Example 3 except that the wood was subjected to vacuum pressurization without using the DDAC solution. Comparative Example 4

The remainder was identical to that of Example 4 except that the wood was subjected to vacuum pressurization without using the DDAC solution. Comparative Example 5

The remainder was identical to that of Example 5 except that the wood was subjected to vacuum pressurization without using the DDAC solution. Comparative Example 6

The rest was the same as in Example 6, except that the wood was subjected to vacuum pressurization without using the DDAC solution. Comparative Example 7

The rest was the same as in Example 7 except that the wood was subjected to vacuum pressurization without using the DDAC solution. Comparative Example 8

The rest was the same as in Example 8 except that the wood was subjected to vacuum pressurization without using the DDAC solution. Experimental Example 1 Boron retention test

The content of boron in the test piece was measured by wet ashing.

1. Preparation of the lost test piece

Wood loss experiments were conducted in accordance with the American Wood Preservation Association Standard AWPA E11-07.

The test pieces prepared in Examples 1-8 and Comparative Examples 1-8 were respectively sawed into small squares of 19χ19χ19mm, and each set of examples and each set of comparative examples were taken into 6 small squares, and each group was placed into 16 groups. In a 500ml beaker, add 300ml of deionized water, the wood block is completely submerged by water, put the beaker into a vacuum device, vacuum the vacuum to a relative vacuum of -0.03MPa, and after vacuuming for 20min, release the vacuum. After that, seal the cup with plastic wrap to prevent evaporation of water, and put the beaker at constant temperature. The loss test was performed on the oscillator, and the oscillation speed was set at 80 r/min. The lost water was replaced with fresh deionized water at 6 h (hours), 24 h, 48 h and every 48 h thereafter, and the loss was continued for 14 days. After the loss was completed, the pieces were taken out at 40-60 ° C. Dry to constant weight with a relative humidity of 60-80%.

2, determine the boron content

The wood blocks prepared in Examples 1-8 and Comparative Examples 1-8 and the wood blocks of the lost test pieces of Examples 1-8 and Comparative Examples 1-8 were respectively cut into small wood chips and pulverized into wood powder, and the wood powder was placed. In a dry box, dry at 105 ° C for 24 h. Weigh 0.5 g of dried wood flour to the nearest 0.001 g. Put the wood powder into a custom quartz digestion tube, add 5ml HN0 ₃ , soak the sample for overnight, insert the quartz digestion tube into the digestion device, raise the temperature to 150 ° C, and keep it for lh, then add 2ml HC10 ₄ to raise the temperature to At 180 ° C, and kept for 2h until the solution is clear and transparent, if it is opaque, continue to extend the heating time. The digestion solution was transferred to a 100 ml volumetric flask and made up to volume with deionized water. Finally, the boron content in the solution was measured by inductively coupled plasma optical emission spectrometry (ICP-OES).

The formula for calculating the retention of boron is as follows: η= - χ 100 (1)

A

In formula (1): η - the loss rate of boron in the test piece (%) _;

A——the amount of boron (mg) in the test piece that has not been lost;

B ^ The content of boron (mg) in the test piece after the loss test.

The test results of boron retention are shown in Table 1.

Table 1

Comparative Example 2 1.2 15.1 0.2 1.2 98.8 Comparative Example 3 0.2 2.9 0.0 0.8 99.2 Comparative Example 4 4.7 61.1 0.7 1.1 98.9 Comparative Example 5 2.0 26.3 0.4 1.4 98.6 Comparative Example 6 1.3 17.3 0.1 0.8 99.2 Comparative Example 7 0.2 2.4 0.0 1 99.0 Comparative Example 8 5.0 64.3 0.3 0.5 99.5 The experimental results show that: the loss rate of boron in the preservative wood prepared by the method of the invention is low, less than 23.6%; the retention rate of boron is high, reaching 75-100%; the anticorrosive wood prepared by the method of the invention overcomes The existing boron-based preservative has a high loss rate and does not meet the defects of wood anti-corrosion effect. Experimental Example 2 Corrosion resistance test

Corrosion resistance test was carried out in accordance with the national standard GB/T 13942.1-1992 "Testing methods for natural corrosion resistance of wood by wood natural durability test method".

The test pieces prepared in Examples 1-8 and Comparative Examples 1-8 and the lost test pieces of Examples 1-8 and Comparative Examples 1-8 prepared according to the loss test method of the American Wood Preservation Association Standard AWPA E11-07, respectively, and The fir (blank group) without any treatment was used as a sample for the corrosion resistance test, and the sample was sawn into small pieces having a size of 19 x l9 x 10 mm and subjected to a corrosion resistance test.

Remove the sample from the test for 12 weeks, gently scrape off the surface hyphae and impurities, and dry it to a constant weight in an oven at 40 ± 5 ° C. Weigh each sample separately and calculate the weight loss rate (in percentage) meter).

Sample weight loss rate (%) = ( W1-W2 ) /Wl xlOO

Where: W1—the weight before the test of the sample; W2—the weight after the test of the sample.

The test results are shown in Table 2.

Table 2 Test results of weight loss of anticorrosive wood:

Example 3 7.8 8.1 6.6 7.2 Example 4 0 0.3 -0.5 0

Example 5 1.2 0.7 0 2

Example 6 3.5 2.7 2.2 3.1

Example 7 8.5 7.6 5.2 9.1

Example 8 -0.8 -1 0 0

Comparative Example 1 18.3 27.3 16.3 30.5 Comparative Example 2 20.6 29.6 22.0 28.7 Comparative Example 3 25.0 33.8 24.5 33.4 Comparative Example 4 0.7 25.2 0.3 24.9 Comparative Example 5 19.5 22.5 20.3 25.0 Comparative Example 6 22.3 25.6 18.5 27.5 Comparative Example 7 22.6 30.1 21.6 31.2 Control Example 8 1.1 26.8 0.8 25.5 Blank group 31.6 - 33.2 - The experimental results show that: the weight loss rate of wood is low, less than 10%, indicating that the preservative of the present invention has high anticorrosive property, and the anticorrosive wood treated by the preservative of the present invention is preserved. The effect is remarkable, and the corrosion resistance is enhanced, which meets the requirements of the national standard GB/T 13942.1-1992 "Laboratory test method for natural corrosion resistance of wood by wood natural durability test method".

Claims

Claim

A wood preservative characterized by comprising sodium fluoroborate and dimercaptodimethylammonium chloride.

The preservative according to claim 1, wherein the molar ratio of the sodium fluoroborate to dimercaptodimethylammonium chloride is 1: 0.8-2.

3. A method for preserving wood, comprising the following steps:

2) Soaking the wood to be treated in a sodium fluoroborate solution, first performing vacuum treatment, and then performing a pressure treatment to cause the wood to absorb the sodium fluoroborate solution, and then depressurizing, taking out the wood and drying it;

3) Soak the dried wood in a solution of dimercaptodimethylammonium chloride, first vacuuming, then pressurizing the wood to absorb the dimercaptodimethylammonium chloride solution, and then depressurize , remove the wood;

4) Dry wood, sodium fluoroborate and dimercaptodimethylammonium chloride in the wood react to form a boron-insoluble compound that is poorly soluble in water.

The preparation method according to claim 3, wherein the sodium fluoroborate solution has a mass percentage concentration of 0.1 to 2%, and the mass percentage concentration of the dimercaptodimethylammonium chloride solution is fluoroboric acid. 3-6 times the sodium solution.

The preparation method according to claim 3 or 4, wherein in the steps 2) and 3), the relative vacuum degree of the vacuum treatment is -0.05 to -0.09 MPa, and the treatment time is 20-60 min; The relative pressure of the pressure treatment is 1.0-4.0 MPa, and the treatment time is 30-240 min.

6. A method for preserving wood, comprising the steps of:

2) Soak the wood to be treated in a solution of dimercaptodimethylammonium chloride, first vacuuming, then pressurizing the wood to absorb the dimercaptodimethylammonium chloride solution, and then depressurize , remove the wood and dry it;

3) soaking the dried wood in the sodium fluoroborate solution, first performing vacuum treatment, and then performing a pressure treatment to cause the wood to absorb the sodium fluoroborate solution, and then depressurizing, and taking out the wood;

7. The preparation method according to claim 6, wherein the sodium fluoroborate solution has a mass percentage concentration of 0.1 to 2%, and the mass percentage concentration of the dimercaptodimethylammonium chloride solution is fluorine. 3-6 times the sodium borate solution.

The preparation method according to claim 6 or 7, wherein the vacuum degree of the vacuum treatment in steps 2) and 3) is -0.05 to -0.09 MPa, and the treatment time is 20-60 min; The relative pressure of the treatment is 1.0-4.0 MPa, and the treatment time is 30-240 min.

9. A method for preserving wood, comprising the steps of:

2) Put the wood to be treated into a vacuum pressurized tank, first evacuate it, then introduce sodium fluoroborate solution, then pressurize the wood to absorb the sodium fluoroborate solution, then relieve the pressure, remove the wood and remove it. Drying;

3) Put the dried wood into a vacuum pressurized tank, first evacuate it, then introduce the dimercaptodimethylammonium chloride solution, and then pressurize it to make the wood absorb dimercaptodimethyl chloride. Ammonium solution, then relieve pressure, remove the wood;

10. The preparation method according to claim 9, wherein the sodium fluoroborate solution has a mass percentage concentration of 0.1 to 2%, and the mass percentage concentration of the dimercaptodimethylammonium chloride solution is fluoroboric acid. 3-6 times the sodium solution.

The preparation method according to claim 9 or 10, wherein the relative vacuum degree of the vacuuming treatment in steps 2) and 3) is -0.05 to -0.09 MPa, and the treatment time is 20-60 min _; The relative pressure of the treatment is 1.0-4.0 MPa, and the treatment time is 30-240 min.

12. A method for preserving wood, comprising the steps of:

3) Put the dried wood into a vacuum pressurized tank, first evacuate it, and then introduce sodium fluoroborate solution. Then, a pressure treatment is performed to cause the wood to absorb the sodium fluoroborate solution, and then the pressure is released to take out the wood;

13. The method according to claim 12, wherein the sodium fluoroborate solution has a mass percentage concentration of 0.1 to 2%, and the mass percentage concentration of the dimercaptodimethylammonium chloride solution is fluoroboric acid. 3-6 times the sodium solution.

The preparation method according to claim 12 or 13, wherein the relative vacuum degree of the vacuuming treatment in steps 2) and 3) is -0.05 to -0.09 MPa, and the treatment time is 20-60 min; The absolute pressure of the treatment is 1.0-4.0 MPa, and the treatment time is 30-240 min.

15. An anticorrosive wood characterized by being prepared according to any of claims 3 to 14.