CS259239B1 - A method of reducing the flammability of lignocellulosic materials - Google Patents

Abstract

The purpose of the method for reducing the flammability of lignocellulosic materials is to improve the resistance of lignocellulosic materials to ignition of these materials under thermal stress. The said purpose is achieved by treating lignocellulosic materials with an alkylating agent, such as a 30 to 50 wt. % aqueous solution of 1,3-bis/3-chloro-2-hydroxypropyl/imidazolium hydrogen sulfate or a 50 wt. % aqueous solution of 3-chloro-2-hydroxypropyl-trimethylammonium chloride or a 2-hydroxypropane solution of sodium 2-chloroethylsulfonate at. at 25 to 105 °C for 2 to 72 hours Lignocellulosic materials are alkylated with 1,3-bis(3-chloro-2-hydroxypropyl)imidazolium hydrogen sulfate at 105 °C for 16 to 24 hours, or with 3-chloro-2-hydroxypropyl-trimethylammonium chloride at 25 to 105 °C for 16 to 72 hours, or with sodium 2-chloroethylbis(thiophene)sulfate at 80 to 105 °C for 3 to 14 hours. The alkylating agent 1,3-bis(3-chloro-2-hydroxypropyl)imidazolium hydrogen sulfate is activated with a 10% by weight aqueous solution of sodium hydroxide. The alkylating agent 3-chloro-2-hydroxypropyl-trimethylammonium chloride, soaked into the lignocellulosic material, is activated with 17.5 wt. % aqueous solution of sodium hydroxide and allowed to react at. temperature 60 °C for 3 hours. Before alkylation of lignocellulosic materials with sodium 2-chloroethylsulfonate, the lignocellulosic material is activated with 10 to 30 wt. % aqueous solution of sodium hydroxide. The method for reducing the flammability of lignocellulosic materials has applications in the construction, mining and furniture industries.

Description

259239

The invention relates to a method for reducing the flammability of ligno-cellulosic materials. Wood, wood or other lignocellulosic materials are used as structural, decorative or insulating materials in the construction, furniture and construction industries. Their undesirable property is low fire resistance. Freto is required to modify these materials to reduce flammability. So far, the most common method of modification is impregnation with inorganic compounds such as sodium chloride, sodium dichromate dihydrate, boric acid, ammonium sulfate, aluminum chloride hexahydrate, zinc chloride, ammonium dihydrogen phosphate, bicarbonate or organic compounds such as urea, tetrahydroxymethyl-2,4-diamino -6- (3,3,3-tribromo-1-propyl) -1,3,5-triazine [Editorial Board of American Dyestuff Reporter74, 13 (1985); L. H. Chance: J. Appl. Polym. Sci. 26, 2959 (1981); S. L. Van: The Chemistryof Solid Hood, p. 531, Washington D.C. (1984)]. The impregnation is carried out in 5 to 30% by weight. or the retarders are applied in the form of coatings. The disadvantage of the aforementioned processes is that they can be washed out of the materials successively with water, thereby reducing their fire resistance, aesthetic appearance and mechanical properties.

The above mentioned drawbacks are eliminated by the method according to the invention, characterized in that the lignocellulosic materials are treated with an alkylating agent such as 30 to 50% by weight. an aqueous solution of 1,3-bis (3-chloro-2-hydroxypropyl) imidazolium hydrogen sulfate or 50 wt. an aqueous solution of 3-chloro-2-hydroxypropyltrimethylammonium chloride or a 2-hydroxypropane solution of sodium 2-chloroethylsulfonate, at 25 to 105 ° C for 2 to 72 hours. Lignocellulosic materials are alkylated with 1,3-bis (3-chloro-2-hydroxypropyl) imidazolium hydrogen sulphate at 105 ° C for 16-24 hours, or 3-chloro-2-hydroxypropyltrimethylammonium chloride at 15-105 ° C for 16-72 hours, or are alkylated with sodium 2-chloroethyl sulfonate at 80-105 ° C for 3-14 hours. The 1,3-bis (3-chloro-2-hydroxypropyl) imidazolium hydrogen sulphate alkylating agent is activated with 10% by weight. aqueous sodium hydroxide solution. The 3-chloro-2-hydroxypropyltrimethylammonium chloride alkylating agent soaked in the lignocellulosic material is activated with 17.5% by weight. aqueous sodium hydroxide solution and reacted at 60 ° C for 3 hours. By alkylation of the ligno-cellulosic materials with 2-chloroethylsulfonate, the lignocellulosic material is activated by 10 to 30% by weight. aqueous sodium hydroxide solution. An advantage of the method of reducing the flammability of the ligno-cellulosic materials is that the flame retardant protective layer is chemically bonded and it is not possible to reduce its concentration by washing with water in a humid environment.

By chemically linking the functional groups, in addition to reducing the flammability, the dyeability of the modified materials is improved and the resistance to rot is increased. Another advantage of reducing the concentration of solutions with the reagent in the range of 2.5 to 30 wt. in contrast thereto, where a concentration of 5 to 30% by weight is used. Example 1

Spruce plates of 80 mm in width, 10 mm in width and 4 mm in diameter are placed in a 300 cm steel autoclave containing 50 ml of 50% by weight. an aqueous solution of 1,3-bis (3-chloro-2-hydroxypropyl) imidazolium hydrogen sulfate (Apreton BA). After closure, the autoclave is tempered for 20 hours at 105 ° C. The yield of platelets modified with 1,3-bis (3-chloro-2-hydroxypropyl) imidazolium hydrogen sulphate is 117.2 wt% after washing with water and drying to constant weight. The flammability of spruce platelets of 80 mm in width, 10 mm in width and 4 mm in diameter of modified sl, 3-bis / 3-chloro-2-hydroxypropyl / imidazolium hydrogen sulphate is determined by the limiting oxygen number method ČSN 64 0756. with nitrogen to ignite the study material. The limit oxygen number of the plates modified with 1,3-bis (3-chloro-2-hydroxypropyl) imidazolurahydrogen sulphate is 32.8 vol% oxygen. Unmodified spruce plates have a limiting oxygen number of 23.5% by volume of oxygen. Fodla CSN 73 0862 changes its flammability from C 2 to C 1, from medium-flammable material to hardly flammable material. 3 259239 Example 2

The procedure is as in Example 1 except that 200 ml of 30 wt. of an aqueous solution of 1,3-bis (3-chloro-2-hydroxypropyl) imidazolium hydrogen sulfate containing 10% by weight of sodium hydroxide. The material was heated at 105 ° C for 24 hours. After removal from the autoclave, the squashes modified with 1,3-bis (3-chloro-2-hydroxypropyl) imidazolium hydrogen sulfate are washed out with water and dried to constant weight. The yield is 108.2% by weight. The oxygen limit number of the plates is 31.5% by volume of oxygen, which corresponds to the reduction of the flammability of C2 to C teda, hence the medium-flammable material to the non-combustible material. Example 3

The procedure is as in Example 1 except that a filter paper (7.55 µg flat 0.086 m 2) is used. Temper for 16 hours at 105 ° C. The resulting filter paper, modified with 1,3-bis (3-chloro-2-hydroxypropyl) imidazolium hydrogen sulphate, is dried to constant weight after washing with water. Yield 153.2%. The limited oxygen modified material is 34.5% by volume of oxygen, which corresponds to the reduction of flammability from C2 to Cj, ie from the medium-flammable material to the hardly flammable material. Example 4

Spruce plates of 80 mm in width, 10 mm in width and 4 mm in diameter are placed in a 300 cm2 steel autoclave containing 50 ml of 50% by weight. of an aqueous solution of 3-chloro-2-hydroxypropyltrimethylammonium chloride (Dextrosil). After closing, the autoclave was tempered for 20 hours at 105 ° C. After removal, trimethylammonium 2-hydroxypropyl plates are washed with water and dried to constant weight. Yield: 145.7%. trimethylammonium 2-hydroxypropyl smear plates. The oxygen limit number is 27.2% by volume oxygen. The flammability of the material changes from C2 to C ^, ie from a medium-flammable to a highly flammable material. Example 5

The beech plates of the same dimensions as in Example 1 are immersed in their entire volume up to 50% by weight. the aqueous solution of 3-chloro-2-hydroxypropyltrimethylammonium chloride for three days. The plates after activation can be activated for two hours to 17.5% by weight. aqueous sodium hydroxide solution and, after removal, are tempered for three hours at 60 ° C. After removal, trimethylammonium 2-hydroxypropyl plates are washed with water and dried to constant weight. The yield is 163.3% by weight. trimethylammonium-2-hydroxypropylcobalt platelets. The oxygen limit number is 28.8% by volume oxygen. The flammability of the material changes from C2 to C ^, hence the medium flammable material. Example 6

The procedure is as in Example 4 except that a filter paper of 7.55 g 2 is used. about 0.086 m / s and 50 ml of 50% by weight. of an aqueous solution of 3-chloro-2-hydroxypropyltrimethylammonium chloride contains 5 wt. sodium hydroxide. It is then tempered for 16 hours at 105 ° C. Trimethylammonium 2-hydroxypropyl paper is washed off with water and dried to a perfect weight. Yield: 114.2%. trimethylammonium 2-hydroxypropyl paper. The limit oxygen number is 19.4% by volume oxygen. The flammability of the material changes from C2 to Cj, ie from a medium-flammable to a non-flammable material. Limit oxygen number of unmodified paper 18.4% by volume oxygen. Example 7

The beech plates, 80 mm, 10 mm, and 4 mm thick, were alkalized in excess of 30% by weight for two hours. aqueous sodium hydroxide solution. After decanting the solution, the material was transferred to 175 ml of 2-hydroxypropane containing 4.5 g of sodium 2-chloroethyl sulfonate and tempered

Claims (7)

259239 over three hours at 80 ° C. After the solution was decanted, the sulfoethyl plates were washed with water and dried to constant weight. Yield: 167.2%. The oxygen-oxygen number in this manner is 33.5% by volume of oxygen. The material turns the C2 flame retardant into Cj, a flammable material from a medium to flammable bag. Example 8 The procedure is as in Example 7 except that spruce plates are used. Yield 143.2%. sulfoethylated spruce platelets. The oxygen limit number of the modified platelets is 32.5% by volume oxygen. The material changes the flammability from C2 to C ^, hence the combustible medium to the bag. EXAMPLE 9 Spruce plates of 80 mm in width, 10 mm in width and 4 mm in diameter are placed in a 300 cm steel autoclave containing 70 ml of 5 wt. the aqueous solution of sodium 2-chloroethyl sulfonate. After the material was closed, the temperature was maintained at 105 ° C for 24 hours. Sulfoethyl derivatives of the lactose plates were dried to constant weight after washing with water. Yield: 129.1%. sulfoethylated spruce platelets. The limit number of such modified platelets is 32.2% by volume of oxygen. The material changes the flammability from C2 to C ^, hence the medium flammable material. The invention can find a wide range of applications in the construction, mining, furniture and textile industries. SUBJECT MATTER A method for reducing the flammability of lignocellulosic materials, characterized in that the lignocellulosic materials are treated with an alkylating agent such as 30 to 50% by weight. an aqueous solution of 1,3-bis (3-chloro-2-hydroxypropyl) imidazolium hydrogen sulfate or 50 wt. aqueous 3-chloro-2-hydroxypropyltrimethylammonium chloride or 2-hydroxypropane solution of sodium 2-chloroethylsulfonate, at 25 to 105 ° C for 2 to 72 hours. 2. The process of claim 1 wherein the lignocellulosic materials are alkylated with 1,3-bis (3-chloro-2-hydroxypropyl) imidazolium hydrogen sulphate at 105 DEG C. for 16-24 hours. 3. The process of claim 1 wherein the lignocellulosic materials are alkylated with 3-chloro-2-hydroxypropyltrimethylammonium chloride at 25 DEG-105 DEG C. for 16-72 hours. 4. The process of claim 1 wherein the lignocellulosic materials are alkylated with sodium 2-chloroethyl sulfonate at 80-105 ° C for 3-24 hours. 5. The method of claim 1, wherein the alkylating agent is activated by 10% by weight. aqueous sodium hydroxide solution. 6. The method of claim 1, wherein the alkylating agent is activated at 17.5% by weight. aqueous sodium hydroxide solution and reacted at 60 ° C for 3 hours. 7. The process of claim 1, wherein the lignocellulose material is activated by 10 to 30% by weight prior to alkylation. aqueous sodium hydroxide solution. Severografia, n. P., MOST Price 2,40 Kcs