JP2003003329A - Phenol resin fiber and method of producing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a phenol resin fiber that comprises unreacting phenols and a novolak type phenol resin of reduced content of binuclear phenol compounds, shows excellent melt extrusion spinnability and high drawability and can shorten the times of insolubilization and infusibilization and provide the method of producing the same. SOLUTION: Phenols and aldehydes are allowed to react with each other by using an organic phosphonic acid and the resultant novolak type phenol resin is converted into fibers whereby the objective phenol resin fibers are obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a phenol resin fiber obtained by fiberizing a novolac type phenol resin and a method for producing the same. The phenol resin fiber of the present invention is suitably used, for example, in work clothes, safety protection equipment and the like that require flame retardancy, and is also used as carbon fiber and fibrous activated carbon by carbonization and activation treatment. . Moreover, the method for producing a phenol resin fiber of the present invention provides a method suitable for obtaining such a resin fiber.

[0002]

2. Description of the Related Art Conventionally, in order to fiberize a novolac type phenolic resin, a novolac type phenolic resin is synthesized by a usual method, and unreacted phenols in the resin are washed with water,
It was necessary to remove the solvent by a method such as solvent fractionation or distillation. Although it is possible to form fibers even with unreacted phenols remaining, the obtained fibers often contain voids in the fibers, which is a drawback that they tend to break during fiber formation by melt spinning or the like. Have Further, even after the insoluble and infusible treatment of the resin fiber, there are drawbacks such that heat resistance and strength are lowered due to the free phenols. Furthermore, when a large amount of binuclear components are present in the novolac type phenolic resin,
Since the binuclear component reacts first during insolubilization and insolubilization treatment, the crosslink density decreases and the unreacted component of the high molecular weight component increases, and heat resistance and strength decrease, so it is desirable to remove this. It is difficult to remove by vacuum distillation etc., and it is necessary to perform special distillation such as steam distillation, which requires a great number of steps. Further, when the binuclear body is removed by such a method, the amount is 45 to 55 relative to the amount of phenol at the time of charging.
The resin could be obtained only in a yield of about%.

As a method for making the novolac type phenol resin fiber insoluble and infusible, a method of immersing the phenol resin fiber in an aqueous solution of formaldehyde and hydrochloric acid and heating at a temperature within a range where the fiber is not melted to crosslink is generally used. ing. At this time, since the general phenol resin fiber contains a large amount of low molecular weight components such as a binuclear body, it has a low softening point and must undergo an insolubilization / infusible reaction at a low temperature at which the resin does not melt. There was a drawback of having time. For example, in JP-B-48-11284, in order to insolubilize the obtained novolac type phenolic resin fiber, the temperature of the aqueous solution is gradually raised from 40 ° C. to 60 ° C. over 3 hours, and further, The temperature is raised from 60 ° C to 100 ° C over 1 hour. In order to improve such a defect that the reaction occurs at a low temperature for a long time, for example, JP-A-2-289
In JP-A-117, the reaction is carried out under pressure, but since high pressure is used, regulation on the device side becomes a problem. Further, in JP-A-64-68517, insolubilization and infusibilization by ultraviolet rays are carried out, but since a solvent is used when adding a photoinitiator, the number of steps for treating this solvent later increases. come.

There is a method of increasing the molecular weight as a means for improving the softening point of the novolac type phenol resin in order to prevent the phenol resin fiber from being melted at a low temperature during the insolubilization treatment. However, in the novolac type phenolic resin obtained from the reaction of trifunctional phenols and aldehydes, the branched structure in which three methylene groups are added to one phenol nucleus increases as the molecular weight increases. Are known. When the number of methylene groups added to the phenol nucleus is two, the resin has a linear structure and thermoplasticity, but the number of methylene groups is three.
When they become one, that part becomes a cross-linking point, and an insoluble and infusible resin is produced. For this reason, the novolac type phenol resin has a drawback that a cross-linking structure is formed and gelation occurs when the molecular weight becomes high, although it is a thermoplastic resin.
It was difficult to have a sufficiently large molecular weight. Further, even if the softening point was improved in the range where gelation did not occur, the viscosity at the time of melting was extremely high, and it was not suitable for melt spinning.

[0005]

DISCLOSURE OF THE INVENTION The present invention uses a novolak type phenol resin having a small amount of unreacted phenols and binuclear compounds, and is excellent in melt spinnability and drawability, and is formed by a cross-linking agent such as formaldehyde after fiberization. The present invention provides a phenol resin fiber capable of performing infusible insolubilization treatment in a short time, and a method for producing the same.

[0006]

MEANS FOR SOLVING THE PROBLEMS The present invention provides (1) a phenol resin fiber obtained by reacting a phenol and an aldehyde with an organic phosphonic acid to form a novolak type phenol resin, (2) ) The novolac type phenol resin has an unreacted phenol component of 1% or less in the resin (a), and a binuclear component of 5% or less in the resin (b).
(C) The degree of dispersion is 8 or less, the phenol resin fiber according to the item (1), and (3) the softening point of the novolac-type phenol resin is 90 ° C. or higher. The phenol resin fiber of (4), the organic phosphonic acid (4) is represented by the general formula (I), and the novolac-type phenol resin fiber of any one of (1) to (3), R-PO (OH) ) ₂ (I) (R contains a carbon atom, and -COOH and / or-
PO (OH) ₂ -containing group) (5) A method for producing a phenol resin fiber according to item (1), which comprises reacting a phenol and an aldehyde with an organic phosphonic acid. A method for producing a phenol resin fiber, wherein the water content in the reaction system is 30% by weight or less and the reaction temperature is 110 to 200 ° C.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION Phenols used as a raw material for the novolac type phenolic resin used in the present invention are not particularly limited, but phenol, metacresol, 3,
One or more compounds having a phenolic hydroxyl group such as 5-xylenol and having no substituent other than at least the meta position relative to the phenolic hydroxyl group are used. Although a trifunctional phenol resin having an alkyl group, an aryl group or the like having a large number of carbon atoms as a substituent can be used, phenol and / or metacresol are preferable in consideration of curability. That is, although the molecular weight of a phenol having a large substituent increases, the number of phenol nuclei in the same molecular weight decreases, leading to a decrease in the number of hydroxyl equivalents, and subsequent three-dimensional crosslinking due to a large steric hindrance of the substituent. It may be difficult to do. Further, resorcin may be used in combination within the range where gelation does not occur during the reaction.

The aldehydes used in the present invention are not particularly limited, and formaldehyde, paraformaldehyde, crotonaldehyde, furfural, butyraldehyde, polyacetal and mixtures thereof are used, but formaldehyde is usually used.

Aldehydes (F) and phenols (P)
The reaction molar ratio (F / P) with is preferably 0.1 to 3.0, and more preferably 0.5 to 1.0. It is particularly preferably 0.75 to 0.95. What was reacted under the condition that the reaction molar ratio is below the lower limit,
The yield tends to be low, the molecular weight of the novolac type phenol resin tends to be too small, and it may be difficult to have a sufficiently high softening point.
On the other hand, when the reaction molar ratio exceeds the upper limit, it is difficult to control the molecular weight, and depending on the reaction conditions, gelation or partial gelation may be promoted. As the reaction method, at the start of the reaction, the phenols and the aldehydes may be charged all at once, and a catalyst may be added to cause the reaction, and in order to suppress heat generation at the initial stage of the reaction, the phenols and the catalyst are mixed. After charging, aldehydes may be sequentially added and reacted.

The polydispersity of the novolac type phenolic resin used in the present invention means the polystyrene-reduced number average molecular weight (Mn) and weight average molecular weight (Mn) measured by liquid chromatography such as gel permeation chromatography (GPC). It is a value represented by a ratio (Mw / Mn) of Mw). Generally, for high molecular weight compounds having a molecular weight distribution,
Mw> Mn, the dispersity is a value greater than 1,
It can be said that the smaller this value, the lower the degree of dispersion and the narrower the dispersion. When Mw = Mn, it means a single compound. The dispersity of the novolac type phenolic resin used in the present invention is preferably 8 or less. It is more preferably 5 or less. If the dispersity exceeds 8, the fluidity of the resin tends to decrease, and fiber formation may become difficult.

The content of the unreacted phenol component and the binuclear component in the novolac type phenol resin used in the present invention is preferably 1% or less, more preferably 0.5%, in the unreacted phenol component. It is particularly preferably 0.1% or less. The content of the binuclear component is 5
% Or less, and more preferably 3% or less. When the contents of the unreacted phenol component and the binuclear body are larger than the above upper limits, not only the environmental hygiene aspects such as odor during the handling of the resin but also the reduction of the mechanical strength when the fiber is made insoluble and infusible, Since problems such as a decrease in moisture resistance, a decrease in dimensional stability, and a decrease in carbon yield when carbonized may occur, it is preferably as small as possible. The unreacted phenol component in the present invention is a value measured by an internal standard method using 2,5-xylenol as an internal standard by using a gas chromatography method according to JIS K0114. Also, 2
The nuclear component is measured by a liquid chromatography method, and is obtained by the area ratio of the dinuclear component.

The softening point of the novolac type phenolic resin used in the present invention is preferably 90 ° C. or higher. If the softening point is less than 90 ° C, the reaction must be performed at a low temperature when the fiber is made insoluble and infusible, and the reaction time becomes long. Further, if the softening point is low, the molecular weight is not sufficiently high, so the strength of the fiber before insolubilization may be lowered. The upper limit of the softening point is not particularly specified, but is preferably 200 ° C or lower. More preferably 1
It is 80 ° C or lower. If the softening point exceeds the above upper limit, the resin viscosity during spinning tends to be high, and spinning tends to be difficult.

The organic phosphonic acid used as a catalyst in the method for producing a novolak type phenolic resin fiber of the present invention is an organic compound containing a phosphonic acid group —PO (OH) ₂ , and any of them can be used. Formula (I)
Phosphonic acid represented by is less unreacted phenols,
In addition, it is preferable in order to obtain a narrowly-distributed novolac-type phenol resin in a high yield. R-PO (OH) ₂ (I) (R contains a carbon atom, and-COOH and / or-
It is a group containing PO (OH) ₂ . As the organic phosphonic acid represented by the general formula (I), there are aminopolyphosphonic acids such as ethylenediaminetetrakismethylenephosphonic acid, ethylenediaminebismethylenephosphonic acid, aminotrismethylenephosphonic acid, β-aminoethylphosphonic acid-N, N-. Diacetic acid, aminomethylphosphonic acid-N, N-diacetic acid, 1-hydroxyethylidene-1,1'-diphosphonic acid, 2-phosphonobutane-1,
2,4-tricarboxylic acid, etc. Among these, aminotrismethylenephosphonic acid, 1-hydroxyethylidene-1,1′-diphosphonic acid, and 2-phosphonobutane-1,2,4-tricarboxylic acid, which are industrially mass-produced and inexpensive in view of the purpose of the present invention. Is preferably used.

The amount of the organic phosphonic acid added is preferably 0.001 to 4.0 mol, and more preferably 0.01 to 0.5 mol, based on 1 mol of the phenol.
It is a mole. The greater the amount of organic phosphonic acid added, the less unreacted phenols, and the greater the effect of obtaining a narrowly-distributed novolac-type phenol resin in high yield,
If the amount of catalyst added exceeds 4.0 moles, the effect will not change, and if it is less than 0.001 moles, the effect as a catalyst will not sufficiently appear. In addition to the phosphonic acid as a catalyst, it is also possible to use an oxalic acid, a sulfuric acid, a hydrochloric acid, an acid such as p-toluenesulfonic acid, which is commonly used in the production of novolak type phenolic resins. The combination of these acids is especially 4
It is effective for accelerating the reaction in the polymer region above the nucleus.

In the method for producing a phenol resin fiber of the present invention, the reaction conditions in which the water content in the reaction system is 30% by weight or less and the reaction temperature is 110 to 200 ° C. are not limited to unreacted phenols but also binuclear and This is a condition that is effective for the selective reaction of a low molecular weight novolak type phenolic resin such as a trinuclear compound, and can effectively narrow the molecular weight distribution. In other words, the reaction of unreacted phenols is
The reaction can be sufficiently performed under the conditions other than the above reaction conditions, that is, the conditions of high water content and low temperature.
Selective reaction of low molecular weight components such as nucleolus is insufficient,
The molecular weight distribution tends to be broad.

In the present invention, the amount of water in the reaction system is the total amount of the amount of water in the charged raw materials and the amount of condensed water produced by the reaction, and in the case of reacting while distilling and removing water, The water content is obtained by subtracting the distilled water content from the total amount. The amount of water in the reaction system is preferably 30% by weight or less based on the total weight of the reaction system. The smaller the water content, the higher the effect of reducing unreacted phenols by increasing the reaction rate of the raw materials with the resin, but when it is too small, the organic phosphonic acid becomes highly viscous or solidifies, and the catalytic action decreases. Therefore, it is preferable that the water content be such that water of crystallization can be contained. When the water content exceeds 30% by weight, the effect is almost unchanged. More preferably, it is 1 to 20% by weight.

The reaction temperature is preferably 110 to 200 ° C. When the temperature is lower than 110 ° C., under the condition of low water content as described above, the organic phosphonic acid as the catalyst has a high viscosity or is solidified, and the catalytic action tends to be lowered. 200 on the contrary
If the temperature exceeds ℃, decomposition of organic phosphonic acid and decomposition of novolac type phenol resin may occur. Decomposition of an organic phosphonic acid or a novolac type phenol resin is more preferable because it is less likely to occur at a low temperature, but when the water content of the reaction system is set to 1 to 20% by weight, the organic phosphonic acid does not increase in viscosity or solidify. The temperature range for attaining a sufficient catalytic action is more preferably 130 to 1
It is 60 ° C.

When this reaction is carried out under normal pressure, the reflux temperature is 110 to 200 ° C. in the range of water content of 30% by weight or less.
At this time, the atmospheric pressure reaction is a preferable condition for controlling the temperature and the water content. Other reaction conditions include:
A solvent reflux dehydration reaction using a non-aqueous solvent such as butanol or isopropanol, a high pressure reaction and the like are considered. Further, the reaction of removing the condensed water formed by distillation or the like while adding the aldehyde is a preferable condition because the amount of water in the reaction system becomes constant. However, at this time, unreacted phenols may be easily removed together with water.Therefore, carry out the reaction without distilling unreacted phenols until the unreacted phenols fall below a certain amount. Then, after removing the water by distillation or while removing the water, the reaction can be continued by setting the water content in the reaction system to 30% by weight or less and the reaction temperature to 110 to 200 ° C.

After completion of the reaction, neutralization or washing with water may be carried out to remove the catalyst. Also, if necessary, water or organic solvent,
Furthermore, in order to remove unreacted phenols, atmospheric distillation, reduced pressure distillation, steam distillation and the like can be performed.

In the method for producing a phenol resin fiber of the present invention, an organic phosphonic acid is used as a catalyst, the water content in the reaction system is 30% by weight or less, and the reaction temperature is 110 to 200 ° C.
Is preferred. The reason why a novolak type phenol resin having a narrow molecular weight distribution suitable for fiberization can be obtained in high yield under such reaction conditions is considered as follows. Organic phosphonic acid is a compound that is extremely water-soluble and easily hydrated. And, it has a low solubility in phenols, and the novolac-type phenol resin has a property that the solubility becomes smaller as the molecular weight increases. Therefore, at the time of reaction, a phase is separated into an aqueous phase containing a large amount of an organic phosphonic acid as a catalyst and an organic phase in which a catalyst composed of phenols and novolac type phenol resin hardly exists. Low molecular weight components such as phenols and binuclear compounds are relatively easy to elute in the aqueous phase, and the eluted portion reacts with aldehydes, but high molecular weight components hardly elute and the reaction does not proceed. Further, the novolac type phenol resin eluted in the aqueous phase reacts with the aldehyde to have a high molecular weight and is rapidly extracted into the organic phase, and the reaction does not proceed any further. In this way, a reaction rate difference between the low molecular weight component and the high molecular weight component occurs, and as a result, it is possible to produce a high yield of novolac type phenol resin with a small amount of unreacted phenols and a narrow molecular weight distribution. Becomes

In the method for producing a phenolic resin fiber of the present invention, melt spinning is preferable as a method for forming a novolac type phenolic resin, but any method such as gel spinning or solution spinning by dissolving in a solvent is used. Can also be done. As the method of melt spinning, the novolac type phenol resin after the reaction is transferred to a heat-insulated container having a spinneret at the bottom of the container, and the resin flowing down from the spinneret is wound into fibers at a speed of 50 to 2000 m / min.
The keeping temperature of the container varies depending on the molecular weight of the resin used, but is preferably 150 ° C to 200 ° C. As a method of gel spinning, a novolac type phenol resin dissolved in a solvent such as acetone or DMF is precipitated by adding a poor solvent such as methanol and water, and is stretched, and the solvent is heated at a temperature in a range where the resin does not melt. A fiber can be obtained by removing. As the solution spinning method, acetone,
Obtaining fibers by removing a novolak type phenolic resin dissolved in a solvent such as DMF from a spinneret into a poor solvent such as methanol or water, and then removing the solvent at a temperature within a range in which the resin does not melt You can The diameter of the phenol resin fiber is preferably 200 μm or less, more preferably 100 μm or less, and most preferably 10 μm or less. If the fiber diameter exceeds 200 μm, it tends to be less flexible and difficult to use as a fiber.

The phenol resin fiber obtained by the above method has solvent solubility and thermoplasticity as it is, and is insufficient in strength. Therefore, it is necessary to perform insolubilization treatment using a cross-linking agent such as formaldehyde. The method of making the phenol resin fiber insoluble and infusible is not particularly specified, but as a general method, for example, the phenol resin fiber is dipped in an aqueous solution of formaldehyde and hydrochloric acid, and the temperature in the range where the fiber is not dissolved. Heat with. At this time, in the case of insolubilizing and infusibilizing a fiber using a normal novolac type phenol resin, it is common to carry out a reaction at a low temperature of about 60 ° C. for a long time of about 3 hours. 80-9 by using
Insolubilization can be achieved by carrying out the reaction in a solution at 0 ° C for 1 to 2 hours. Then, by neutralizing with ammonia water or the like, further washing with water, and drying, insoluble and infusible novolac-type phenol resin fibers are obtained.

Further, since the present fiber is a phenol resin fiber, a carbon fiber having a high residual carbon rate can be obtained by carbonizing the insoluble and infusible fiber. This is because the phenol resin used in the present invention has a narrow molecular weight distribution, so that the crosslinking reaction during insolubilization progresses uniformly,
This is because the infusible and infusible fiber having a high cross-linking density can be obtained, and since it is unmodified, it has less volatile components.
It can also be used as fibrous activated carbon by activating the carbon fiber.

As described above, by using the phenolic resin fiber obtained by fiberizing the novolac type phenolic resin of the present invention and the method for producing the same, voids are extremely generated during melting, and the melt spinnability is excellent, It is possible to obtain a phenol resin fiber which can be stretched to have a sufficiently small fiber diameter during spinning and which can be subjected to insolubilization treatment after fiberization in a short time. Further, according to the method for producing a resin fiber of the present invention, since the narrowly-dispersed novolac-type phenol resin as an intermediate raw material can be synthesized in a high yield, the phenol resin fiber can be produced at a low cost.

[0025]

EXAMPLES The present invention will be described below with reference to examples. However, the present invention is not limited to the examples. Moreover, all "parts" and "%" shown in the examples and comparative examples represent "parts by weight" and "% by weight".

<Example 1> Production of novolac type phenol resin A In a 10 L reactor equipped with a stirrer, a cooling pipe and a thermometer, 1000 parts of phenol, 1-hydroxyethylidene-1,1'-diphosphonic acid (1 -1 -Hydroxyethylidene-1,1'-diphosphonic acid (monohydrate) 95% or more, 600 parts of Kishida Chemical Co., Ltd.) was added, and the internal temperature was 120.
After heating up to ℃, 92% paraformaldehyde 285
Parts were added over 30 minutes and then refluxed for 1 hour. Then, add 500 parts of water, and the internal temperature is 100 to 103 ° C.
It was stirred for 30 minutes. The internal temperature was cooled to 60 ° C., and the mixture was left standing for 30 minutes. After standing, the 1-hydroxyethylidene-1,1′-diphosphonic acid aqueous solution was separated and removed from the bottom of the reactor.
After the separation was completed, 1000 parts of water was added to wash the remaining catalyst. After standing for 30 minutes, the washing water was removed from the upper part of the reactor. The system was again switched to the dehydration pipe to carry out atmospheric pressure dehydration up to an internal temperature of 130 ° C., and then vacuum dehydration up to an internal temperature of 150 ° C. at 5000 Pa to remove water and the like in the system. The obtained resin was taken out from the reactor into a vat to obtain 1081 parts of novolac type phenol resin A. Mn of the obtained resin by GPC was 1300, Mw was 5000, and the degree of dispersion was M.
It was w / Mn = 3.85. Moreover, the unreacted phenol component was below the detection limit of measurement, and the amount of binuclear body was 2%. The softening point was 130 ° C.

Production of Phenolic Resin Fiber 1 Novolac type phenolic resin A was roughly crushed and fiberized by a melt spinning apparatus. The resin charged into the hopper was supplied to a single screw, was heated and melted while the screw was moving, and was extruded from a die at the tip through a die.
The screw was heated and adjusted to 180 ° C. Further, the adapter and the dice (2 pieces) were also heated and adjusted to 180 ° C.
The discharge pressure was controlled by the rotation speed of the single screw. The base size used was 0.3 mm × 24 holes.
The extrusion pressure at this time was 1.47 MPa. The resin flowing down from the die was pulled at a winding speed of 1000 m / min to obtain fibers having an average diameter of 7 μm. 3 fibers obtained
It was immersed in a solution obtained by mixing 500 parts of a 7% formalin solution and 500 parts of concentrated hydrochloric acid, and treated at 90 ° C. for 2 hours to make it insoluble and infusible. After completion of insolubilization and insolubilization, the fiber was neutralized with ammonia water, washed thoroughly with water, and further heated at 150 ° C / 2 hours +18.
Phenol resin fiber 1 was obtained by heating at 0 ° C. for 3 hours.

Example 2 Production of Novolac Phenolic Resin B 1095 parts of novolak type phenolic resin B was obtained in the same manner as in Example 1 except that the amount of 92% paraform was charged to 304 parts. Mn by GPC of the obtained resin
= 1500, Mw = 8500, and dispersity Mw / Mn
= 5.67. The unreacted phenol component was below the detection limit of measurement, and the amount of binuclear body was 1.5%. The softening point was 140 ° C.

Production of Phenolic Resin Fiber 2 The novolak type phenol resin B was fiberized by melt spinning in the same apparatus as in Example 1. The heating temperature of the screw, adapter and die was adjusted to 190 ° C. The resin flowing down from the die was pulled at a winding speed of 1000 m / min to obtain fibers having an average diameter of 7 μm. The obtained fiber was made insoluble and infusible in the same manner as in Example 1 to obtain a phenol resin fiber 2.

<Comparative Example 1> Production of novolac type phenol resin C A 1000-liter reactor and a 10-liter reactor equipped with a stirrer, a cooling pipe and a thermometer were charged with 1000 parts of phenol and 10 parts of oxalic acid, and the internal temperature was raised to 95 ° C. under normal pressure. After heating, 37% formalin 733
Parts were added over 1 hour. After performing a reflux reaction at 98 to 100 ° C. for 1 hour, the temperature was raised to 140 ° C. while removing water produced by switching to a dehydration pipe. Next, while gradually reducing the pressure in the pot to 5000 Pa, set the internal temperature to 250 ° C.
After that, water and the like were removed to obtain 1030 parts of novolac type phenol resin C. M of the obtained resin by GPC
n = 1200, Mw = 15000, and dispersity Mw /
It was Mn = 12.50. The unreacted phenol component was 1.3% and the amount of binuclear body was 6.7%.
The softening point was 121 ° C.

Production of Phenolic Resin Fiber 3 The novolak type phenol resin C was fiberized by melt spinning in the same apparatus as in Example 1. The heating temperature of the screw, adapter and die was adjusted to 180 ° C. However, vapor was generated due to unreacted phenol from the die part, and bubbles were present in the resin, and it was impossible to form fibers.

Comparative Example 2 Production of Phenolic Resin Fiber 4 The novolak type phenolic resin C was fiberized by melt spinning in the same apparatus as in Example 1. The heating temperature of the screw, adapter and die was adjusted at 160 ° C. Generation of phenol vapor and bubbles in the resin disappeared, but it could not be wound up at 1000 m / min,
It was wound up at m / min. The diameter of the obtained fiber is about 30 μm
Met. When this was immersed in a solution in which 500 parts of a 37% formalin solution heated to 90 ° C. and 500 parts of concentrated hydrochloric acid were mixed, the fibers were fused and the shape of the fibers could not be maintained.

<Comparative Example 3> Production of Phenolic Resin Fiber 5 The fiber obtained in Comparative Example 2 was treated with 37% formalin solution 500.
Part and 500 parts of concentrated hydrochloric acid, soak it in a mixed solution at 40 ℃
To 60 ° C. over 2 hours. Furthermore, the internal temperature is 9
The temperature was raised to 0 ° C. over 1 hour and treated at 90 ° C. for 2 hours to make it insoluble and infusible. After completion of insolubilization and infusibilization, the fiber was neutralized with ammonia water, washed thoroughly with water, and further heated at 150 ° C / 2.
Hours + 180 ℃ / 3 hours heating, phenol resin fiber 5
Got

The results of the resins produced in the above Examples and Comparative Examples are shown in Table 1. In addition, Table 2 shows the processing time for fiberization and the results of the fiber tensile test in each example. The measuring method of each physical property value is as follows. (Measurement method) 1. Number average molecular weight, weight average molecular weight, dispersity: measured by liquid chromatography Liquid chromatography: Tosoh GPC column (G
1000HXL: 1, G2000HXL: 2, G3
000HXL: 1 bottle), the flow rate is 1.0 ml / min, the elution solvent is tetrahydrofuran, and the column temperature is 40 ° C. The GPC measurement is performed using a differential refractometer as a detector under the analysis conditions, and the molecular weight is converted to standard polystyrene. 2. Unreacted phenol amount: measured by gas chromatography. Gas chromatography: Measured by an internal standard method using 2,5-xylenol as an internal standard according to JIS K0114. 3.2 Amount of nuclei: It was determined by the area ratio of the binuclear components in liquid chromatography. 4. Softening point: Measured according to JIS K2531. 5. Tensile strength: Performed according to JIS L1013. 6. Elongation rate: Performed according to JIS L1013.

[0035]

[Table 1]

[0036]

[Table 2]

In Examples 1 and 2, phenol and formaldehyde were reacted using an organic phosphonic acid to synthesize a novolac type phenol resin, but the amount of unreacted phenol in the resin and the amount of dinuclear component were both small, The polydispersity of the molecular weight distribution was small, and the softening point temperature was 130 to 140 ° C., which was a preferable range for fiberization. When resin fibers were produced by melt spinning using these, it was possible to obtain resin fibers having excellent tensile strength and elongation. On the other hand, oxalic acid was used as a catalyst for the reaction between phenol and formaldehyde to synthesize a novolac type phenol resin, and using this, fiberization was attempted under the same conditions as in the examples. However, in Comparative Example 1, the fiber could not be formed, and in Comparative Example 2, although the fiber was formed, the speed of the fiber formation was decreased and the obtained fiber diameter was large. In addition, fusion occurred during the subsequent insolubilization and infusibility. In Comparative Example 3, the fiber was made insoluble and infusible, and the phenol resin fiber could be obtained. However, unlike Example, long-term treatment was required at low temperature. The resin fiber obtained was inferior in both tensile strength and elongation as compared with the examples.

[0038]

INDUSTRIAL APPLICABILITY The present invention is a phenol resin fiber obtained by fiberizing a novolac type phenol resin obtained by reacting phenols and aldehydes with an organic phosphonic acid, and a method for producing the same. The novolac-type phenol resin fiber can be insolubilized and infusibilized at a higher temperature and in a shorter time than before. This is because the amount of unreacted phenols and binuclear compounds in the novolak resin used is small,
This is because the softening point is high. Further, since the degree of dispersion is small and the crosslinking occurs uniformly, it can be applied to a wide range of applications and is suitable as an industrial novolac type phenol resin fiber.

Claims (5)

[Claims] 1. A phenol resin fiber obtained by fiberizing a novolac type phenol resin obtained by reacting a phenol and an aldehyde with an organic phosphonic acid. 2. The novolac type phenolic resin is (a).
The unreacted phenol component in the resin is 1% or less, (b) the binuclear component in the resin is 5% or less, (c) the dispersity is 8 or less,
The phenolic resin fiber according to claim 1. 3. The phenol resin fiber according to claim 1, wherein the novolac type phenol resin has a softening point of 90 ° C. or higher. 4. The novolac type phenolic resin fiber according to claim 1, wherein the organic phosphonic acid is represented by the general formula (I). R-PO (OH) ₂ (I) (R contains a carbon atom, and-COOH and / or-
It is a group containing PO (OH) ₂ ) 5. The method for producing a phenol resin fiber according to claim 1, wherein the amount of water in the reaction system when the phenols and the aldehydes are reacted with an organic phosphonic acid is 30% by weight or less. , The reaction temperature is 110 ~ 200 ℃
And a method for producing a phenolic resin fiber.