KR20090047673A - Process for producing a benzoxazine resin and benzoxazine resin - Google Patents

Abstract

The present invention provides a benzoxazine resin which can exhibit flame retardancy without defects such as fish eye due to low moisture content, and a benzoxazine resin that can secure product stability while removing efficiency of water and organic solvent generated during condensation. It provides a batch production method of.

Description

Process for producing a benzoxazine resin and benzoxazine resin

The present invention relates to a method for producing benzoxazine resins and benzoxazine resins, and more particularly, to bens which can be used in encapsulating materials, impregnations, laminates, adhesives, paints, coating materials, friction materials, fiber reinforced plastics (FRP) and molding materials. The manufacturing method and resin of benzoxazine ring are related.

Thermosetting resins having a benzoxazine ring in its molecular structure are subject to encapsulating materials, impregnations, laminates, adhesives, paints, coating materials, friction materials, FRP, molding materials, etc., since the oxazine ring is opened by heating and polymerization proceeds without generation of byproducts. It is attracting attention as a thermosetting resin used. The benzoxazine ring has a complex structure of a benzene ring and an oxazine ring.

In particular, benzoxazine resin is useful as a phenolic curing agent in a laminate epoxy resin composition for copper clad laminate sheets (CCLS), and the epoxy resin composition requires heat resistance and flame retardancy for new process applications such as lead-free. For CCLS epoxy resin compositions, V-0 certification of the UL-94 standard is mandatory. Conventionally, halogenated resins such as brominated epoxy resins and antimony oxide have been used in epoxy resin compositions for CCLS laminates to impart such flame retardancy. Halogenated resins have a high flame retardant effect, but when released, they emit toxic substances such as hydrogen halides and adversely affect the global environment such as the generation of dioxin. In particular, the recent movement of regulations on the use of environmentally hazardous substances has become active all over the world, and the demand for this is gradually increasing in the PCB field. Accordingly, the development of raw materials to replace the flame retardant harmful to the environment is required, and various alternatives such as organic phosphorus compounds and metal hydroxides have been proposed as new flame retardants.

As an alternative, the use of a phenol-based curing agent having a benzoxazine ring can ensure flame retardancy.

The benzoxazine resin is low viscosity and can be self-cured without high glass transition temperature and by-products, and does not generate volatiles upon curing. It also has several advantages, such as being a nitrogen-containing compound suitable for non-halogen products.

However, in the preparation of such benzoxazine resin, a large amount of water is generated as a condensation by-product, and in the process of removing the water and the organic solvent used, the conventional method of manufacturing by thin film evaporator is reaction control and reproducibility. There was a difficulty in securing. Specifically, the thin film distillation method is a flowable process, which is suitable for producing large-capacity products, but it must maintain high vacuum and high temperature, especially the temperature of the fruit oil must be maintained at 300 ℃ or higher, use a complex solvent, and the viscosity becomes uneven. It is born. In addition, unknown adverse effects due to heat, rotation, reduced pressure, thinning, and the like also occur. In addition, there is a problem that the relatively high temperature residence time is increased due to the volume increase. This results in low uniformity and low precision and product deviations.

In order to solve this problem, a method for preparing benzoxazine by a batch process has been proposed. For example, US Pat. No. 7,041,772 discloses a benzoxazine resin synthesized by reacting a phenol compound, an aldehyde compound, and an amine in the presence of an organic solvent. Thereafter, a method for producing benzoxazine resin is described by removing the generated condensed water and the organic solvent from the reaction system, but setting the reaction system to a pressure of 260 mmHg or more when removing the system out of the system.

The method for producing benzoxazine resin by the batch process is easier to control the reaction process than the conventional thin film distillation method and is suitable for the production of critical products such as electric and electronic materials. In addition, due to the low reaction temperature, the general phenol novolak production and its cost are comparable, process stability can be secured, stable physical properties can be secured, and the existing phenol resin manufacturing equipment can also be utilized. In addition, there is less chance of deviation for each lot.

However, the problem of switching to a batch process is disadvantageous in terms of the removal efficiency of the condensed water produced as compared to the thin film distillation method, and the boiling point such as methyl ethyl ketone as the organic solvent by the method described in US Pat. No. 7,041,772 is 100 ° C. or less. When an organic solvent is used and the condensed water is removed out of the system, a large amount of water is present in the obtained benzoxazine resin when it is accompanied by vacuum control of about 260 mmHg, substantially up to 360 mmHg. In other words, the benzoxazine resin having a high water content is obtained because of poor water removal efficiency.

Excessive water in the benzoxazine resin may cause defects such as fish-eye on the thin film when applied for CCLS laminate and the like, which may adversely affect the adhesive strength of the product.

The present invention is to provide a benzoxazine resin having a low moisture content and less occurrence of defects during formation of the laminate.

The present invention provides a benzoxazine resin capable of forming a laminate having low moisture content and excellent flame retardancy.

The present invention is to provide a method for producing a benzoxazine resin that can efficiently remove the condensed water generated during the reaction.

In one embodiment of the present invention, a phenol compound, an aldehyde compound, and an amine compound are reacted in the presence of an organic solvent, and the condensed water and the organic solvent are removed out of the system to produce a benzoxazine resin. An organic solvent having a boiling point of less than 112 ° C. as a reaction solvent and an organic solvent having a boiling point of 112 ° C. or more as a solvent for controlling water are provided.

In the method for producing a benzoxazine resin according to the embodiment of the present invention, the solvent for controlling the water may have a boiling point of 112 to 135 ℃.

In the preferred method for preparing benzoxazine resin according to the embodiment of the present invention, the removal of the generated condensed water and the organic solvent is performed under high vacuum of 750 mmHg or more.

In the method for preparing a benzoxazine resin according to an embodiment of the present invention, the solvent for controlling water is selected from methyl isobutyl ketone (MIBK), isobutyl acetate, butyl alcohol, methyl cellosolve, ethylenic glycol, and perchloroethylene. More than a species can be used.

In the method for preparing benzoxazine resin according to the embodiments of the present invention, the reaction solvent is one selected from methyl ethyl ketone, toluene, ethyl acetate, acetone, isopropyl alcohol, cyclohexane, propyl acetate, methyl alcohol, and isobutyl alcohol. It may be more than.

In the method for preparing benzoxazine resin according to the embodiment of the present invention, the reaction solvent and the solvent for controlling water may be used in a weight ratio of 1: 1 to 1: 2.

In the method for preparing benzoxazine resin according to the embodiment of the present invention, the solvent for controlling water may be added at the same time as the reaction solvent or may be added before the step of removing condensed water and organic solvent generated.

Another embodiment of the present invention provides a benzoxazine resin containing a trace amount of an organic solvent having a water content of 0.5% or less and a boiling point of 112 ° C. or more without a separate solvent formulation.

The benzoxazine resin according to the embodiment of the present invention may include a trace amount of an organic solvent having a boiling point of 112 to 135 ° C.

The benzoxazine resin according to the embodiment of the present invention may include a trace amount of one or more organic solvents selected from methyl isobutyl ketone, isobutyl acetate, butyl alcohol, methyl cellosolve, ethylenic glycol, and perchloroethylene.

According to the present invention, it is possible to provide a benzoxazine resin having low moisture content and excellent flame retardancy in a later process, and a batch of benzoxazine resin capable of producing a stable product with high water removal efficiency and high removal efficiency of an organic solvent. It can provide a method for producing a formula.

The present invention will be described in more detail as follows.

In the present invention, the mechanism of benzoxazine synthesis is shown in Scheme 1 below.

Is a residue except for an amino group.

As an example of the phenolic compound used in this invention, monofunctional phenol, polyfunctional phenol, or a mixture of monofunctional phenol and polyfunctional phenol is mentioned. In addition, the said monofunctional phenol and polyfunctional phenol can also be used individually or in mixture of 2 or more types. Herein, the monofunctional phenol may have at least one or more active hydrogens in the ortho position relative to the hydroxyl group. Examples of the monofunctional phenol include cresols such as phenol, o-cresol, m-cresol, and p-cresol; ethyl phenols such as o-ethyl phenol, m-ethyl phenol, and p-ethyl phenol; butyl phenols such as n-butylphenol, s-butyl phenol and t-butyl phenol; Alkyl phenols such as trimethyl phenols such as 2,3,4-trimethyl phenol, 2,3,5-trimethyl phenol, 2,4,5-trimethyl phenol and 3,4,5-trimethyl phenol; aryl phenols such as o-phenylphenol, m-phenylphenol and p-phenylphenol; aralkyl phenols such as o-benzyl phenol, m-benzyl phenol and p-benzyl phenol; alkenyl phenols such as o-vinyl phenol, m-vinyl phenol, p-vinyl phenol, p-vinyl phenol, o-allyl phenol, m-allyl phenol and p-allyl phenol; alkoxy phenols such as o-methoxy phenol, m-methoxy phenol, p-methoxy phenol, o-ethoxy phenol, m-ethoxy phenol and p-ethoxy phenone; halogenated phenols such as o-chloro phenol, m-chloro phenol and p-chloro phenol; Although monofunctional phenols, such as naphthols, such as alpha-naphthol and beta-naphthol, are mentioned, It is not limited to these.

Polyfunctional phenols are, for example, bisphenol, dihydroxy diphenyl ether, dihydroxy benzophenone, isopropylidene bisphenol, ethylidene bisphenone, methylene bisphenol, cyclohexylidene bisphenol, 1-phenylethylidene bisphenol, Bisphenols having at least one or more active hydrogens in ortho-grade for one hydroxy group such as phenyl methylene bisphenol, sulnil bisphenol, and methylene bis-4-methyl phenol; Methylidenetribisphenol, ethylidenetribisphenol, 1- (4- (1- (4-hydroxyphenyl) -1-methyl ethyl phenyl) ethylidenebisphenol, bis ((2-hydroxy) -5-methylphenyl)- Tris phenols which have at least 1 or more active water tank in ortho position with respect to 1 hydroxyl group, such as 4-methyl) phenol; 1,1,2,2-tetrakis (4-hydroxyphenyl) ethane, 1,1,3,3-tetrakis (4-hydroxyphenyl) propane, 1,1,5,5-tetrakis (4 Tetrakis phenols having at least one active hydrogen at the ortho position relative to one hydroxy group such as -hydroxyphenyl) pentane; Novolak resins such as phenol novolak resin, cresol novolak resin and isopropylidene bisphenol novolak resin; Modified phenol resins such as xylene-modified phenol resins, dicyclopentadiene-modified phenol resins, butadiene-modified phenol resins, melamine-modified phenol resins, and guanamine-modified phenol resins; Although polyhydroxy styrene, catechol, resorcin, hydroquinone, pyrogarol, etc. are mentioned, It is not limited to these, Among these, monofunctional phenols are preferable as phenol, cresol, and polyfunctional phenol. Volac resin, methylene bisphenol, isopropylidene bisphenol, and the mixture of such monofunctional phenols and polyfunctional phenols are mentioned.

Examples of the amines include monofunctional amines or polyfunctional amines, and mixtures of monofunctional amines and polyfunctional amines. In addition, the said monofunctional amines and polyfunctional amines can be used individually or in mixture.

These amines are, for example, methyl amine, cyclohexylamine, ethylene diamine, hexamethylene diamine and aromatic amines of aliphatic amines, aniline, toluidine, benzyl amine, bromoaniline, anidine, xylidine, phenylene diamine and diamino. Amines, such as diphenyl ether, diamino benzophenone, diamino diphenyl methane, and diamino diphenyl sulfone, etc. are mentioned, It is not limited to these. Preferred of these are aniline, toluidine and the like.

As an aldehyde compound, aromatic aldehyde compounds, such as formaldehyde and benzaldehyde, can be mentioned, for example. As the aldehyde compound, formaldehyde is preferable. Formaldehyde can be used in forms such as formalin and paraformaldehyde.

In order to synthesize benzoxazine resin, a phenol compound, an amine and an aldehyde compound are preferably 0.5 to 1.2 moles, more preferably 0.75 to 1.1 moles, and an aldehyde compound per mole of amine per mole of phenolic hydroxyl group of the phenol compound. Preferably from 1.7 to 2.3 moles, more preferably from 1.8 to 2.2 moles. Since amines tend to volatilize during the reaction, it is necessary to pay attention to the weight loss in the reaction system. Also, when the amount of amines is reduced, some of the phenolic hydroxyl groups of the phenol compound remain unreacted, and thus the cured product characteristics such as hardenability and mechanical strength are reduced. Although it is easy to improve, it is easy to adjust and control such a compounding quantity of a primary amine as mentioned above. The same applies to the aldehyde compound.

In the method for producing a benzoxazine resin of the present invention, two kinds of organic solvents, which are organic solvents that function as reaction solvents and moisture control solvents, are used in combination, wherein the reaction solvents have boiling points lower than 112 ° C. For example, alcohol solvents, such as methyl alcohol, isobutyl alcohol, and ethanol, ketone solvents, such as acetone and methyl ethyl ketone, aromatic solvents, such as toluene, are mentioned. In addition, ethyl acetate, propyl acetate, cyclohexane may be used.

The solvent for controlling water is an organic solvent having a high boiling point to efficiently remove water in removing condensed water and organic solvents generated after the synthesis of benzoxazine resin to the outside of the system, for example, methyl isobutyl ketone ( MIBK), isobutyl acetate, butyl alcohol, methyl cellosolve, ethylenic glycol, perchloroethylene, etc. are mentioned.

In view of the water removal efficiency, the solvent for controlling the water may advantageously have a boiling point of at least 112 ° C. or higher, preferably 112 to 135 ° C.

The ratio of the amount of organic solvent used depends on the reaction solvent and the solvent for controlling water. Using in a weight ratio of 1: 1 to 1: 2 may be advantageous in terms of molecular weight control.

As for the total usage-amount of an organic solvent, 20-40 weight% is preferable with respect to the sum total of the input of reaction raw material. When the amount of the organic solvent is too small, the viscosity of the reaction solution is high, and the stirring stress is large. When the amount of the organic solvent is too large, it is uneconomical to remove the organic solvent after the reaction.

The preparation of benzoxazine resin is carried out as follows.

Although a raw material may be mixed with a reaction solvent in an appropriate order, since reaction is exothermic reaction, it is necessary to be careful about a sudden temperature rise. Preferably, after dissolving a phenol compound in an organic solvent, an aldehyde compound is added and stirred, Then, the solution which melt | dissolved amine in the organic solvent can be divided | segmented into dividing into multiple times, or it can be dripped continuously. At this time, the dropping speed is such that bumping does not occur. In addition, when the reaction is carried out under reflux, the reaction temperature conditions can be easily stabilized.

60 degreeC or more is preferable and reaction temperature is performed at the reflux temperature of an organic solvent. The reaction termination can be confirmed by the remaining amount of unreacted raw materials. For example, when 99% or more of the theoretical reaction amounts of the amine when fully reacted react, it is considered that the reaction is terminated.

According to the present invention, in the synthesis of the benzoxazine resin, a solvent for controlling water may be added together with a reaction solvent, but only a solvent for controlling water may be added separately after the completion of the reaction separately from the reaction solvent. In terms of water removal efficiency, it may be more advantageous to add it separately after the completion of the reaction.

After completion of the reaction, the condensed water, the organic solvent and the like generated during the synthesis are removed. At this time, the benzoxazine resin can be obtained by concentrating under reduced pressure. Concentration under reduced pressure is carried out under heating.

According to the present invention, by using a solvent for controlling water, the pressure of the reaction system can be performed at high vacuum at 760 mmHg, thereby increasing the water removal efficiency.

The benzoxazine-based resin obtained by the reaction has self-curability. Therefore, in order to prevent the softening point or molecular weight from changing due to the progress of self-curing the benzoxazine-based resin obtained by the reaction, the temperature of the reaction solution under reduced pressure is particularly preferably 100 ° C. or lower.

The benzoxazine resin obtained through such a series of processes has a water content of 5% or less, and a trace of a high boiling point solvent used as a solvent for controlling moisture remains. As will be appreciated, such traces of high boiling point solvents do not cause significant physical property inhibition in the field where benzoxazine resins are applied.

The present invention will be described in more detail with reference to the following specific examples, and it is obvious to those skilled in the art that the present invention is not limited to the following examples.

Example 1

In a 5 L flask equipped with a thermometer, a stirrer, a cooling tube, and a dropping device, 400 g of bisphenol a with a number average molecular weight (measured using a standard polystyrene calibration curve by gel permeation chromatography) and 300 g of methyl ethyl ketone It stirred and dissolved. To this, 1020 g of paraformaldehyde was added. While stirring, 325 g of aniline was dripped over 1 hour. The temperature of the reaction solution at this point was 81 ° C. Thereafter, the mixture was reacted under reflux (80 to 82 ° C) for 7 hours.

600 g of methyl cellosolve was added thereto.

Then, concentration under reduced pressure was initiated at 760 mmHg under heating.

After confirming that all the outflow liquids disappeared (melting temperature of resin at this time 120 degreeC), resin was taken out to the bat. The softening point of the resin was 83 ° C. with a Melttler meter under elevated conditions of 2 ° C./min., And the melt viscosity was 2P or higher under ICI Viscometer, spindle # 2, 900 rpm, 150 ° C.

The water content of the obtained benzoxazine resin was 0.11%, N content was 6.05580%, and methyl cellosolve remained about 0.05%.

At this time, the water content of the resin was analyzed by Karl Fisher Method by the Korea Chemical Testing Institute, and the N content was analyzed by Flash EA1112 of Thermofinigan. Analysis of the remaining solvent was carried out using HPLC, Agilent 1100 series, Microbondapak C18 column, 25% MeOH mobile phase at 270 nm, 1.0 ml / min. 10 μl of sample diluted to 3,000 ppm in the flow was measured.

Specifically, the analysis of the residual solvent can be analyzed by G1888 series GC-MASS Head Space based on the Avant 7890A, 5975A.

0.1 g of sample is weighed, GC conditions-Oven Inlet 250, Spirit Lacey 100: 1

 MASS CONDITIONS-Sauce 230, Mass Cured 150 ° C, Range 0-550 AM,

 Headspace Conditions-Analyze under oven 220 ° C, loop 230 ° C, transferline 240 ° C, carrier 15, vial 10psi.

Example 2

A benzoxazine resin was prepared in the same manner as in Example 1, except that methylcellosolve was added together with methyl ethyl ketone during the benzoxazine resin synthesis step.

The softening point of obtained resin was 80 degreeC, and melt viscosity was 2P or more at 150 degreeC. The water content of the obtained benzoxazine resin was 0.09%, N content was 6.2730%, and methyl cellosolve remained about 0.055%.

Examples 3 to 5

A benzoxazine resin was prepared in the same manner as in Example 1, except that a reaction solvent and a solvent for controlling water were used as shown in Table 1 below.

Reaction solvent Moisture Control Solvent Example 3 toluene Methyl Cellosolve Example 4 Acetone Methyl Solosolve Example 5 MEK MIBK

Analysis results of each benzoxazine resin obtained according to the organic solvent combination change are shown in Table 2 below.

Softening Point (℃) Viscosity (150 ℃, P) Moisture content (%) N content (%) Remaining reaction solvent (%) Residual moisture control solvent (%) Example 3 87 2.76 0.08 6.053 0.2 0.09 Example 4 84 2.42 0.12 5.987 0.15 0.11 Example 5 83.4 2.38 0.11 6.031 0.12 0.13

From the results in Table 2, it can be seen that there is some difference in the water removal ability according to the solvent combination, and also slightly different in the residual moisture control solvent content.

Reference Example 1

A benzoxazine resin was prepared in the same manner as in Example 1, but the vacuum degree was reduced to 500 mmHg.

The softening point of obtained resin was 77 degreeC, and melt viscosity was 1.8 P or more at 150 degreeC. The water content of the obtained benzoxazine resin was 0.45%, N content was 5.7142%, and methyl cellosolve remained about 0.34%.

As a result, it can be seen that the case of using a reaction solvent and a solvent for controlling moisture in combination with high vacuum is more advantageous for removing water and lowering the content of the solvent for controlling residual moisture.

Comparative Example 1

In a 5 L flask equipped with a thermometer, a stirrer, a cooling tube, and a dropping device, a number average molecular weight (measured using a calibration curve of standard polystyrene by gel permeation chromatography) of 1040 g of phenol novolak resin 400 and methyl ethyl ketone 560 g was added and stirred and dissolved. To this, 600 g of paraformaldehyde was added. While stirring, 931 g of aniline was dripped over 1 hour. The temperature of the reaction solution at this point was 81 ° C. Thereafter, the mixture was reacted under reflux (80 to 82 ° C) for 7 hours. Then, concentration under reduced pressure was initiated at 360 mmHg under heating. Concentration was continued, maintaining this pressure reduction degree, and when the temperature of the reaction solution became 110 degreeC, the pressure reduction degree was raised to 90 mmHg. After confirming that all the outflow liquids disappeared (melting temperature of resin at this time 120 degreeC), resin was taken out to the bat. The softening point of resin was 115 degreeC, and melt viscosity was 40 p or more at 150 degreeC. In addition, the temperature of the reaction solution in local minimum (R) was 52 degreeC.

The water content in the resin obtained therefrom was 0.87%, and the N content was 6.1207. There existed as much as 0.387 MEK as a residual organic solvent.

Experimental Example

Epoxy resin compositions were prepared as follows in order to apply to laminate production using the benzoxazine resins obtained according to Examples 1 to 6 and Comparative Example 1.

Benzoxazine resin content: 26.985 wt%

Epoxy Resin Content (YDCN-90P): 23 wt%

Curing accelerator (TPP) content: 0.015% by weight

PMA (propylene glycol monomethyl ether acetate) content: 50% by weight

The epoxy resin composition thus obtained was applied onto a glass fabric and dried at 150 ° C. for 3 minutes in a hot air oven.

As a result of visually confirming the occurrence of fish eye with respect to the sheet obtained therefrom, when the benzoxazine resins according to Examples 1 to 6 were not included, there was no fish eye generation, whereas when the benzoxazine resin according to Comparative Example 1 was included, the fish There is a child outbreak. The case containing the benzoxazine resin obtained according to Example 1 is shown in FIG. 1, and the case containing the benzoxazine resin obtained according to the comparative example 1 is shown in FIG.

As a result, when the benzoxazine has a water content of 0.5% or less, it can be seen that it does not cause a defect such as a fish eye in the post-process, and as a result, it may act more advantageously in terms of flame retardant expression.

1 is a photograph of the case where the benzoxazine resin obtained according to Example 1 is impregnated and dried in the glass fabric according to the mixing conditions.

Figure 2 is a photograph of the benzoxazine resin obtained according to Comparative Example 2 impregnated in the glass fabric according to the mixing conditions, dried.

Claims (10)

In a method for producing a benzoxazine resin by reacting a phenol compound, an aldehyde compound and an amine compound in the presence of an organic solvent, and removing the generated condensed water and the organic solvent out of the system, A method for producing a benzoxazine resin, characterized in that an organic solvent having a boiling point of less than 112 ° C. as an organic solvent and an organic solvent having a boiling point of at least 112 ° C. are used as a solvent for controlling water. The method for producing a benzoxazine resin according to claim 1, wherein the solvent for controlling water has a boiling point of 112 to 135 ° C. The method for preparing benzoxazine resin according to claim 1, wherein the generated condensed water and the organic solvent are removed under a high vacuum of 750 mmHg or more. The method of claim 1 or 2, wherein the solvent for controlling water is one or more selected from methyl isobutyl ketone, isobutyl acetate, butyl alcohol, methyl cellosolve, ethylenic glycol, and perchloroethylene. Method for producing a benzoxazine resin. The reaction solvent according to claim 1 or 4, wherein one or more selected from methyl ethyl ketone, toluene, ethyl acetate, acetone, isopropyl alcohol, cyclohexane, propyl acetate, methyl alcohol, and isobutyl alcohol is used. Method for producing a benzoxazine resin, characterized in that. The method of claim 1, wherein the reaction solvent and the solvent for controlling water A method for producing a benzoxazine resin, which is used in a weight ratio of 1: 1 to 1: 2. The method for preparing benzoxazine resin according to claim 1, wherein the solvent for controlling water is added at the same time as the reaction solvent or before the step of removing the condensed water and the organic solvent generated separately from the reaction solvent. A benzoxazine resin having a water content of 0.5% or less and containing a trace amount of an organic solvent having a boiling point of 112 ° C. or higher without a separate solvent formulation. 9. The benzoxazine resin according to claim 8, which contains a trace amount of an organic solvent having a boiling point of 112 DEG C to 135 DEG C. The method according to claim 8 or 9, characterized in that it comprises a trace amount of at least one organic solvent selected from methyl isobutyl ketone, isobutyl acetate, butyl alcohol, methyl cellosolve, ethylenic glycol, and perchloroethylene. Benzoxazine resin.

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