JPS6367564B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention involves dissolving chemically modified wood in phenols, adding hexamethylenetetramines to the solution to obtain a spinning solution, and discharging it into the air from a spinneret to form a filament, The present invention relates to a method for producing fibers by curing the filamentous body by heating. (b) Industrial Application Fields There is currently a great desire to develop more effective methods of using forest resources, which are renewable resources. In addition, in industries that use wood as raw materials, such as the pulp industry and the wood industry, there is an urgent need to establish methods for effectively utilizing wood waste. Therefore, the present inventors conducted a simple chemical reaction to
As a result of discovering the fact that wood that has been given plasticity dissolves in phenols and further considering the advanced use of this dissolved material, we invented a technique to make filaments with sufficient strength. (b) Prior art In order to make advanced use of wood, wood is made to have plastic properties through simple chemical reactions such as esterification or etherification.
Attempts have been made to make more advanced use of wood-based raw materials including wood. For example, JP-A-57-103804 and JP-A-56-103804
No. 135552 discloses a technology for esterifying or etherifying wood (powder) in which some of the hydroxyl groups have been introduced with organic groups, and the plasticized wood thus obtained can be used as is or with various synthetic polymer substances. It is described that the mixture is used as a molding raw material. Furthermore, JP-A-57-2360 discloses a technique for preparing a solution by dissolving plasticized wood obtained by esterifying or etherifying wood (wood flour) by introducing hydroxyl groups into an organic solvent. It is also described that the prepared solution can be molded into a film either alone or in co-dissolution with various synthetic polymers. However, no technology has been developed to date to dissolve plasticized wood obtained by esterification or etherification into fibers by dissolving it in phenols. In addition, Japanese Patent Publication No. 51-25485, No. 51-19492, and No. 51-2526 describe a method for manufacturing phenolic composite fiber containing 0.2 to 30% by weight of a thermofusible resin or a urea compound, a melamine compound, etc. ing. However, these descriptions do not include composites with chemically modified plastic wood, and the curing method is also completely different from that of the present invention. That is, the curing methods described in the above-mentioned Japanese Patent Publications No. 51-25485, No. 51-19492, and No. 51-2526 advance curing by further reacting formaldehyde in an aqueous solution with a catalyst, but the method of the present invention , only heating operation is required. (c) Object of the invention The object of the present invention is to dissolve plasticized wood obtained by treating wood with a plasticizing modifier in phenols, further add a curing agent to form a spinning solution, The object of the present invention is to provide a method for obtaining cured wood phenol fibers by curing filaments spun from the above by heating. (d) Structure of the invention The method for producing wood phenol fiber according to the present invention includes:
By introducing at least one type of substituent into some or all of the hydroxyl groups, the plasticized wood is dissolved in phenols under heating conditions, hexamethylenetetramines are added to the solution, and spinning is performed. It may be made into a liquid, or a spinning solution may be prepared by adding formalin to the solution and blowing ammonia into it. The spinning solution is discharged into the air from a spinneret and cured under heating conditions to produce wood phenol fibers. (e) Preferred embodiments The raw material for producing plasticized wood is wood powder blasted pulp, mechanical pulp, or partially or completely delignified pulp. Further, there is no restriction on the type of wood used as a raw material, and the method of the present invention can be applied to any type of wood. The plasticization modification reaction of the present invention that introduces substituents into wood raw materials is a reaction that introduces substituents into at least some of the hydroxyl groups of cellulose, hemicellulose, or lignin present in the wood raw materials, for example, by introducing substituents into at least some of the hydroxyl groups of cellulose, hemicellulose, or lignin present in the wood raw materials. This is a reaction to esterify or etherify the moiety. Esterification and etherification reactions are preferred as such plasticization modification reactions. Modifiers used for esterification and etherification include free acids, acids and their derivatives such as acid halides and acid anhydrides, and halides such as alkyl halides and ethylene chlorohydrin. Preferred examples of substituents introduced by the plasticization modification reaction include aliphatic acyl groups such as acetyl, propionyl, butyryl, and valeroyl groups, benzoyl and other aromatic acyl groups, methyl groups, and ethyl groups. Examples include lower alkyl groups such as. It is also possible to introduce two or more of these substituents. The introduction ratio of substituents varies depending on the type of substituent, but in general, in order to obtain modified wood with good organic solvent solubility, the substitution ratio expressed as substituent morality should be 7.5 or more. is desirable.
Here, "substituent morality" refers to the number of moles of substituents introduced by substitution per 1000 g of wood. Plastic modification treatment can be carried out according to known techniques. Generally, powdered wood may be treated with a modifier in the presence of an organic solvent or a swelling agent at room temperature to elevated temperatures. Thoroughly wash the wood to be modified. For example, it is poured into methanol, filtered, and washed with water or methanol. Then dry. The dried plastic wood is then dissolved in phenols. A part of this technology for dissolving plasticized wood into phenols was reported at the 32nd Wood Science Society Meeting (1982). Phenols are
A general term for compounds in which the hydrogen atom bonded to the benzene ring is replaced with a hydroxyl group, including phenol, o-cresol, m-cresol, p-cresol,
3,5-xylenol, 2,3-xyresol,
2,4-xylenol, 2,5-xylenol,
Examples include 2,6-xylenol and 3,4-xylenol. It may also be a mixture of the above phenols. The melting device is a container with a cooler or a pressurized container. The melting temperature is 100 to 350°C, and the melting time is about 15 minutes to several hours. The dissolved concentration of plasticized wood ranges from a few percent to 80% on a weight basis, and for 25% or more, it is necessary to uniformly mix the plasticized wood and phenols using a device such as a kneader before melting. . Furthermore, an organic solvent may be added during mixing to achieve more uniform mixing.
They are chloroform, acetone, methylene chloride, methanol, ethanol, etc. Examples of the curing agent include hexamethylenetetramine alone, or a combination of aldehydes such as formaldehyde, paraformaldehyde, and furfural with a catalyst such as ammonia. Next is the spinning process. When the curing agent is hexamethylenetetramine, 3 to 40 parts of the above-mentioned solution is mixed with 1 part (by weight) of hexamethylenetetramine to completely dissolve it and prepare a spinning solution. The mixing temperature is 70-90°C. Alternatively, aldehydes are added to the above solution, and ammonia or the like is blown into the solution to obtain a spinning solution. introducing the mixed spinning solution into an extruder equipped with a spinneret;
After heating to 100 to 150°C for 3 to 10 minutes, the yarn is discharged into the air from a spinneret, and the discharged yarn is wound up by a winder. The wound uncured discharge yarn is subsequently subjected to a curing treatment. The curing method may be heating in air, and the curing temperature is 150 to 300°C, preferably 180 to 250°C. The temperature increase rate from room temperature may be 10 to 60°C/min, or lower. Uncured fibers made of 100% phenol melt and lose their shape before reaching the curing temperature. On the other hand, in the case of wood phenolic fiber,
It reaches the curing temperature with almost no melting, and can be cured while maintaining the fiber form. Figure 1 shows differential thermal analysis curves with heat on the vertical axis and temperature on the horizontal axis for the wood phenol fiber (containing 50% acetylated wood) A of the present invention and the uncured fiber B consisting of 100% phenol. It is. phenol
In the case of 100% uncured fiber B, an endothermic peak of melting is observed at 50°C, but in the case of wood phenol fiber A, no endothermic peak is observed. In addition, the curing start temperature is 160℃ for 100% phenol, but it is 110℃ and 50℃ for wood phenol fiber.
The curing reaction begins at a low temperature of ℃, and the curing peak is also
The temperature has dropped to 155℃ and 50℃. 100% phenol
The curing peak for this case is 205°C. Also, the reason why the spinning and curing reactions are carried out using only hexamethylenetetramines or by adding aldehydes and blowing ammonia into them is that uncured fibers spun with formalin-based novolac etc. and uncured fibers made only with hexamine are different from each other. When compared at the same degree of condensation, the melting point of the latter is much higher than that of the former. For example, Shiro Tsuruta "Reaction of phenol and hexamethylenetetramine"
(“Thermosetting Resin” Vol. 3, No. 4, 44-56 (1982))
In the paper, hexane-based dimer

While the melting point of [Formula] is 168℃, formalin-based

[Formula] is stated to be 122°C, and it can be seen that the hexamine type shows a much higher melting point compared to the same degree of condensation. This is also an important point to carry out the curing reaction while maintaining the fiber shape. Example 1 After drying, 3 g of radiata pine refined ground pulp (RGP) was weighed and placed in a reactor.
A mixed solution of 114 mmol of trifluoroacetic anhydride and 120 mmol of acetic acid, which had been aged in advance at 50°C for 30 minutes, was placed in the reactor, the temperature was set at 50°C, and the mixture was allowed to react for 2 hours. After the reaction is completed, the reaction solution is dispersed in 1.5 methanol to decompose excess acylating reagent, and then dried. The substituent morality of the obtained modified wood was 12.6. 50 parts (by weight) of the modified wood thus obtained and 50 parts (by weight) of phenol were placed in a kneader, and the temperature was 60
Mix at ℃ for about 1 hour. After mixing, the sample was placed in a reactor equipped with a reflux device and heated at 200 to 220℃ for 6 hours.
Reflux for an hour to obtain a completely dissolved mixture. 1 part (by weight) of hexamethylenetetramine is added to 8 parts (by weight) of the solution and stirred at 90°C to dissolve hexamethylenetetramine. The solution is used as a spinning solution. The spinning solution was put into a spinning machine heated to 150°C, and after being left for 5 minutes, a circular spinneret (hole diameter
0.5min) into the air. The extruded filament was then stretched and wound to a diameter of 40 μm. The rolled up uncured wood phenol fibers are transferred to a furnace where the temperature is raised from room temperature to 250°C at a rate of 20°C/min and held for 30 minutes to complete curing. Note that the atmosphere inside the furnace was air. The strength values of the obtained wood phenol fibers are as follows. The tensile strength is
The weight was 17Kg/mm ² and the elongation was 12%. Example 2 3 g of dried Pine Radiata RGP and 4.0 ml of acetic acid are placed in a reaction vessel and left at room temperature for 2 hours with occasional stirring. After this pretreatment is completed, mix 18 ml of acetic acid, 8.4 ml of acetic anhydride, and 0.15 ml of sulfuric acid, add the above mixture to the ice-cooled acetic acid mixture, and react with shaking in a constant temperature bath at 50°C for 2 hours. . After the reaction is completed, 8.0 ml of water is added and the saponification reaction is carried out at 70°C for 3 hours. After the saponification reaction is completed, 1 is added to stop the reaction.
The product was poured into 300 ml of % magnesium acetate aqueous solution, stirred, collected in a glass filter, and diluted with 0.1% magnesium acetate aqueous solution.
Wash with 2% aqueous magnesium acetate solution, water, and dry. The substituent morality of the obtained modified wood was 8.0. 60 parts (by weight) of the modified wood thus prepared and 40 parts (by weight) of phenol were put into a kneader and kneaded at 50°C for 30 minutes, then placed in a pressurized container and heated at 230°C for 4 hours. Obtain a completely dissolved mixture. 1 part (by weight) of hexamethylenetetramine was added to 8 parts (by weight) of the mixed solution, and the solution was completely dissolved by stirring at 90°C, and the spinning solution was put into a spinning machine heated to 145°C. After standing for 4 minutes, the circular spinneret (pore size
0.5 mm) into the air, then stretched and wound. The diameter of the wound filament was 30μ. The uncured wood phenolic fiber thus obtained was introduced into a furnace with an air atmosphere and heated at 250℃ for 30 minutes.
Leave for a minute to complete the curing process. This wood phenol fiber had a tensile strength of 16.5 Kg/mm ² and an elongation of 13%. Example 3 30 g of dried beech wood RGP is placed in a reactor.
A mixed solution of 1.14 mol of trifluoroacetic anhydride and 1.2 mol of acetic acid, which had been aged in advance at 50°C for 30 minutes, is placed in the above reactor, the temperature is set at 50°C, and the mixture is allowed to react for 2 hours. After the reaction was completed, the reaction solution was dispersed in 15 methanol to decompose the excess acylation reagent, and then
dry. The substituent morality of the obtained modified wood was 11.5. 50 parts (by weight) of the modified wood thus obtained and 50 parts (by weight) of phenol were placed in a kneader and kneaded at 50℃ for 30 minutes, then transferred to a container with a reflux device and heated at 200℃ for 4 hours. Heat until completely dissolved. 1 part (by weight) of hexamethylenetetramine was added to 10 parts (by weight) of the dissolution mixture and dissolved at 90-100°C, which was used as a spinning solution.
The spinning solution was placed in a spinning machine heated to 150° C., and after being left for 5 minutes, it was extruded into the air through a circular spinneret (pore diameter: 0.5 mm), and then stretched and wound. The diameter of the wound filament was 25μ. The uncured wood phenol fiber thus obtained is introduced into a furnace in an air atmosphere and held at 250°C for 30 minutes to complete the curing process. This wood phenol fiber had a tensile strength of 18 Kg/mm ² and an elongation of 12%.

[Brief explanation of drawings]

FIG. 1 is a graph showing the results of differential thermal analysis of wood phenol fibers produced according to the present invention.

Claims (1)

[Claims] 1 Wood made into plastic by introducing at least one substituent into some or all of the hydroxyl groups is dissolved in phenols, and further hexamethylenetetramines are added or aldehydes are added and ammonia is dissolved. A method for producing wood phenol fibers, which comprises blowing and dissolving the solution, spinning this solution as a spinning solution, and then curing it by heating.