KR20210030668A - Epoxy resins comprising flame retardant polyols and compositions comprising them - Google Patents

Abstract

The present invention relates to a modified epoxy resin prepared by making a phosphorus-based flame-retardant polyol having a specific structure react with an epoxy compound, and a composition comprising the same.

Description

Epoxy resin containing flame-retardant polyol and a composition containing the same TECHNICAL FIELD [EPOXY RESINS COMPRISING FLAME RETARDANT POLYOLS AND COMPOSITIONS COMPRISING THEM}

The present invention relates to an epoxy resin comprising a flame retardant polyol and a composition comprising the same. Specifically, it relates to a composition comprising a modified epoxy resin having a flame retardant property and maintaining mechanical strength, and a cured product thereof.

Epoxy resin is a material widely used in the industry as an adhesive, coating, and insulating material due to its high mechanical properties, thermal and insulating properties. In particular, the proportion of epoxy-based adhesives in the automotive market as an adhesive is high, and the range of application as structural adhesives is increasing. Conventional epoxy adhesives are mainly used as bisphenyl A epoxy resins, and are applied as reactive adhesives that are cured under specific curing conditions by mixing a polymer with improved toughness, a curing agent, and an inorganic filler.

Existing adhesives are mainly focused on improving the bonding performance (shear strength, T-peel strength, impact peeling strength) of the steel-steel adherend, but the adhesive performance of the adhesive is due to the many applications of adhesives for steel-plastic bonding. In addition, consideration of flame retardant performance is increasing to deter possible fire propagation in plastic materials.

Existing flame retardancy is achieved by applying an epoxy resin containing halogen, an epoxy resin containing phosphorus, or applying a composition containing inorganic materials such as aluminum hydroxide and phosphorus. However, halogen causes toxic gas in the event of a fire and has a stability problem, and it is difficult to use it because a halogen-free material is applied in automobile production. In addition, in the case of inorganic materials, it is difficult to secure sufficient flame-retardant performance due to the low proportion of the adhesive, and in the case of general epoxy resins containing phosphorus, when the flame retardancy is increased, mechanical properties are deteriorated, which is not good in practical application.

Therefore, there is an urgent need for a technology for an epoxy resin having excellent mechanical strength while having flame retardancy.

Korean Registered Patent Publication No. 10-1841538 (2018.03.19)

An object of the present invention for solving the above problems is to provide a flame-retardant polyol-modified epoxy resin by reacting an epoxy resin with a polyol containing a large amount of phosphorus.

Another object of the present invention is to increase compatibility with other epoxy resins, and by allowing the flame-retardant polyol-modified epoxy resin synthesized in the epoxy curing matrix to directly participate in the reaction during the curing reaction with an amine curing agent or an acid anhydride, flame-retardant epoxy It is to provide an epoxy that enhances mutual bonding between a resin and other epoxy resins to ensure flame retardancy and suppresses deterioration of mechanical properties.

In order to solve the above problems, an aspect of the present invention provides a modified epoxy resin prepared by reacting a phosphorus-based flame-retardant polyol of Formula 1 and an epoxy compound.

[Formula 1]

In Formula 1, R ₁ is a C ₂ -C ₁₀ alkylene group, R ₂ is a C ₁ -C ₁₀ alkyl group, C ₆ -C ₂₀ aryl group, C ₁ -C ₁₀ alkyl substituted C ₆ -C ₂₀ aryl It is selected from a group and _{an aralkyl group of C 6} -C ₂₀ , and n is an integer of 1 to 20.

In one aspect of the present invention, the phosphorus-based flame-retardant polyol of Formula 1 may have a structure of Formula 2 below.

[Formula 2]

In one aspect of the present invention, the epoxy compound may be any one or two or more compounds selected from the group consisting of bisphenol type epoxy and novolac type epoxy.

In one aspect of the present invention, the epoxy compound may be a compound of the structure represented by the following formula (3).

[Formula 3]

In Formula 3, R ₃ is a structure represented by Formula 4 below.

[Formula 4]

_{R 4} in Formula 4 is a C ₂ -C ₁₀ alkylene, R ₅ and R6 are selected from hydrogen or a C ₁ -C ₁₀ alkyl group and a halogen group substituted C ₁ -C ₁₀ alkyl group, and R ₇ is C ₁ -C ₁₀ alkyl group.

In one aspect of the present invention, the molar ratio of the phosphorus-based flame-retardant polyol and the epoxy-based compound may be 1:1.8 to 1:2.5.

In one aspect of the present invention, the modified epoxy resin may be a compound represented by the following formula (5).

[Formula 5]

_{R 1} in Formula 5 is a C ₂ -C ₁₀ alkylene group, R ₂ is a C ₁ -C ₁₀ alkyl group, C ₆ -C ₂₀ aryl group, C ₁ -C ₁₀ alkyl substituted C ₆ -C ₂₀ aryl group And C ₆ -C ₂₀ is selected from an aralkyl group, n is an integer of 1 to 20, and in Chemical Formula 5, R ₃ is composed of the following Chemical Formula 4.

[Formula 4]

_{R 4} in Formula 4 is C ₂ -C ₁₀ alkylene, R ₅ and R ₆ are hydrogen; C ₁ -C ₁₀ alkyl group, and a halogen group is selected from a _{substituted C 1} -C _{10 alkyl group, R 7} is a C ₁ -C ₁₀ alkyl group.

Another aspect of the present invention provides an epoxy composition comprising an epoxy resin, a curing agent, and a modified epoxy resin according to an aspect of the present invention.

In one aspect of the present invention, the epoxy resin may include any one or two or more compounds selected from the group consisting of bisphenol-type epoxy and novolac-type epoxy.

In one aspect of the present invention, the curing agent may include any one or two or more compounds selected from the group consisting of an aliphatic amine curing agent, an alicyclic amine curing agent, an aromatic amine curing agent, and an acid anhydride-based curing agent.

In one aspect of the present invention, based on 100 parts by weight of the epoxy resin, it may be one containing 1 to 50 parts by weight of the modified epoxy resin.

In one aspect of the present invention, based on 100 parts by weight of the epoxy resin, 0.1 to 50 parts by weight of a curing agent may be used.

The modified epoxy resin according to an aspect of the present invention may improve flame retardancy by synthesizing a flame-retardant epoxy resin through modification of a flame-retardant polyol containing phosphorus to contain a large amount of phosphorus.

In addition, an aspect of the present invention may improve compatibility and bonding with other epoxy resins by synthesizing a flame-retardant epoxy resin through modification of a flame-retardant polyol containing phosphorus, thereby supplementing mechanical properties that may be deteriorated.

In addition, one aspect of the present invention can provide a flame-retardant epoxy through modification of a flame-retardant polyol containing phosphorus, which is convenient to use during polymerization due to a low viscosity of the resin.

1 is an IR comparison data of the synthesized flame-retardant polyol epoxy, flame-retardant polyol, and bisphenol F.

Hereinafter, the present invention will be described in more detail through specific examples or examples including the accompanying drawings. However, the following specific examples or examples are only one reference for describing the present invention in detail, and the present invention is not limited thereto, and may be implemented in various forms.

In addition, unless otherwise defined, all technical and scientific terms have the same meaning as commonly understood by one of ordinary skill in the art to which the present invention belongs. The terms used in the description in the present invention are merely for effectively describing specific embodiments and are not intended to limit the present invention.

In addition, in the present invention, the alkylene group or the alkyl group includes both branched or unbranched unless otherwise defined.

In addition, the singular form used in the specification and the appended claims may be intended to include the plural form unless otherwise indicated in the context.

Epoxy resin is one of the thermosetting resins and is widely used in adhesives, coatings, and composite materials because of its excellent adhesion, strength and toughness, electrical insulation, heat resistance, and waterproofness, as well as excellent mechanical properties.

There are two main methods for imparting flame retardancy to such epoxy resins: adding a halogen material and adding an inorganic cleaning agent including phosphorus. In the case of the addition of a halogen material, a toxic halogen gas is rather released in the event of a fire, and the addition of an inorganic cleaning agent including phosphorus has poor compatibility with an epoxy resin, making it difficult to uniformly blend with the existing resin. In addition, when a flame retardant such as an inorganic cleaning agent is added, there is a problem that mechanical properties of the resin are greatly deteriorated.

The present invention was proposed in order to solve the above problems, and by synthesizing a phosphorus-based flame-retardant polyol of a specific structure, it was found that it is possible to improve flame retardancy without impairing physical properties when manufacturing an epoxy resin, thereby completing the present invention. .

In addition, sufficient flame retardancy can be expressed even when a modified epoxy resin is used in a small amount compared to the conventional flame retardant, and mechanical strength can be maintained without significantly lowering.

One aspect of the present invention relates to a modified epoxy resin prepared by reacting a phosphorus-based flame-retardant polyol of Formula 1 with an epoxy compound.

[Formula 1]

In Formula 1, R ₁ is a C ₂ -C ₁₀ alkylene group, R ₂ is a C ₁ -C ₁₀ alkyl group, C ₆ -C ₂₀ aryl group, C ₁ -C ₁₀ alkyl substituted C ₆ -C ₂₀ aryl It is selected from a group and _{an aralkyl group of C 6} -C ₂₀ , and n is an integer of 1 to 20.

Hereinafter, the modified epoxy resin will be described in more detail.

First, the phosphorus-based flame-retardant polyol represented by Chemical Formula 1 will be described.

The phosphorus-based flame-retardant polyol of Formula 1 may be prepared by polycondensation of a glycol-based compound represented by Formula 6 and a phosphonic dichloride represented by Formula 7.

[Formula 6]

(In Formula 6, R ₁ is selected from a C ₂ -C ₁₀ alkylene group.)

[Formula 7]

(In Formula 7 above, R ₂ is selected from a C ₁ -C ₁₀ alkyl group, a C ₆ -C ₂₀ aryl group, a C ₁ -C ₁₀ alkyl substituted C ₆ -C ₂₀ aryl group and a C ₆ -C ₂₀ aralkyl group And n is an integer of 1 to 20.)

More specifically, Formula 6 may use any one or a mixture of two or more selected from ethylene glycol, diethylene glycol, dipropylene glycol, and propyl glycol, and preferably ethylene glycol.

In addition, in Chemical Formula 7, R ₂ may be (dichloromethyl)phosphonic dichloride and chloromethylphosphonic dichloroide, preferably phosphonic dichloride.

More specifically, in order to synthesize the phosphorus-based flame-retardant polyol of Formula 1, it may be synthesized by polycondensation reaction of a glycol-based compound and a phosphonic dichloride.

In order to synthesize Formula 1, the reaction molar ratio of Formula 7 and Formula 6 may be appropriately adjusted, but preferably may be 1:1 to 2.

In one aspect of the present invention, the phosphorus-based flame-retardant polyol of Formula 1 may be a modified epoxy resin having a structure of the following Formula 2 more specifically.

[Formula 2]

In order to synthesize the phosphorus-based flame-retardant polyol of Formula 2, as an example, Formula 6 may be phenyl phosphonic dichloride, and Formula 7 may be an ethylene glycol compound.

In order to synthesize Formula 2, as an example, the reaction molar ratio of phenyl phosphonic dichloride and ethylene glycol may be appropriately adjusted, but it may be preferably 1:1 to 2, but is not limited thereto.

A solution polymerization method may be used to synthesize a reactive phosphorus-based flame-retardant polyol by polycondensing the phenyl phosphonic dichloride and the ethylene glycol.

The polycondensation reaction of the phosphonic dichloride and the ethylene glycol is a step of reacting the phosphonic dichloride and the ethylene glycol at a temperature of 150 to 300 °C under a reduced pressure condition of 600 to 0.01 mmHg for 1 to 24 hours It may include.

The polycondensation of the phenyl phosphonic dichloride and the ethylene glycol may further include adding a polycondensation catalyst.

As the polycondensation catalyst, a titanium compound, a germanium compound, an antimony compound, an aluminum crab compound, a tin compound, or a mixture thereof may be used.

Examples of the titanium-based compound include tetraethyl titanate, acetyltripropyl titanate, tetrapropyl titanate, tetrabutyl titanate, polybutyl titanate, 2-ethylhexyl titanate, octylene glycol titanate, lactate titanate. Acid, triethanolamine titanate, acetylacetonate titanate, ethylacetoacetic ester titanate, isostearyl titanate, titanium dioxide, titanium dioxide/silicon dioxide copolymer, titanium dioxide/zirconium dioxide copolymer, etc. have. In addition, these may be used alone or in combination of two or more.

Examples of the germanium-based compound include germanium dioxide (GeO2), germanium tetrachloride (GeCl4), germanium ethyleneglycoxide, germanium acetate, a copolymer using these, and Mixtures, etc. are mentioned. Preferably, germanium dioxide may be used, and both crystalline or amorphous may be used as the germanium dioxide, and glycol solubility may also be used.

Next, the reaction product of the polycondensation reaction is filtered to remove salts, and impurities are removed using an extraction solvent. The reaction product of the polycondensation reaction can be filtered to remove the HCl salt. In addition, impurities generated in the polycondensation reaction can be removed with an extraction solvent.

As the extraction solvent, water, dichloromethane, anhydrous or hydrous lower alcohol having 1-4 carbon atoms, propylene glycol, butylene glycol, glycerin, acetone, ethyl acetate, chloroform, butyl acetate, diethyl ether, hexane, and mixtures thereof Any one selected from the group consisting of may be used.

Finally, the reactant from which impurities have been removed is washed with an organic solvent and dried in vacuum to recover the reactive phosphorus-based flame-retardant polyol represented by the following formula (2).

The organic solvent is preferably an ether-based solvent, and the ether-based solvent may be at least one selected from the group consisting of tetrahydrofuran, 2-methyltetrahydrofuran, dimethyl ether, and dibutyl ether, and preferably It may be di methyl ether.

In one aspect of the present invention, the modified epoxy resin may be prepared by reacting a phosphorus-based flame-retardant polyol represented by Formula 2 below with a diepoxy compound.

The following Chemical Formula 2 contains phosphorus and thus has excellent flame retardancy, and may increase the mechanical strength of the phosphorus-based flame-retardant polyol due to the presence of a phenyl group. In addition, hydroxyl groups are present at both ends, so that they can be polymerized with an epoxy group.

[Formula 2]

The epoxy compound may be, as an example, a di-epoxy compound represented by Formula 3 below, but is not limited thereto, and may be used as triepoxy or polyepoxy. As an example, the following Formula 3 refers to a compound containing a glycidyl group at both ends, and condensation polymerization with a hydroxyl group of Formula 1 may be performed to form the phosphorus-based flame-retardant modified epoxy resin containing glycidyl groups at both ends.

[Formula 3]

In Formula 3, R ₃ is a structure represented by Formula 4 below.

[Formula 4]

(In Formula 4, R ₄ is C ₂ -C ₁₀ alkylene, R ₅ and R ₆ is selected from hydrogen or a C ₁ -C ₁₀ alkyl group and a halogen group substituted C ₁ -C ₁₀ alkyl group, and R ₇ is a C ₁ -C ₁₀ alkyl group.)

Preferably, Formula 3 may be a modified epoxy resin that is any one or two or more compounds selected from the group consisting of bisphenol-type diepoxy and novolac-type epoxy. More preferably, it is a bisphenol type (system) diepoxy, bisphenol A di-epoxy (BPA-Di-Epoxy), bisphenol F di-epoxy (BPF-Di-Epoxy), bisphenol S di-epoxy (BPS-Di-Epoxy), bisphenol BPAD-Di-Epoxy, bisphenol M di-epoxy (BPM-Di-Epoxy) can be exemplified, as a novolac type (system) epoxy, phenol novolac epoxy, cresol novolac epoxy (Cresol Novolac Epoxy), BPA Novolac Epoxy (BPA Novolac Epoxy) can be illustrated.

In the case of the bisphenol diepoxy system and the novolac epoxy system, as a compound containing two or more glycidyl groups, a phenyl group having excellent chemical resistance and durability exists in the compound, thereby increasing the physical and chemical durability of the modified epoxy resin. Preferred.

The reaction molar ratio of the phosphorus-based flame-retardant polyol and the epoxy-based compound may be appropriately adjusted, but when a di-epoxy resin is used, it is preferably made of a modified epoxy resin of 1:1.8 to 1:2.5.

More specifically, the modified epoxy resin may be represented by the following Chemical Formula 5, and may be prepared by condensation polymerization of Chemical Formula 1 and Chemical Formula 3.

The following Chemical Formula 5 may preferably be provided by condensation polymerization of Chemical Formula 2 and Chemical Formula 3.

[Formula 5]

(R ₁ in Formula 5 is a C ₂ -C ₁₀ alkylene group, R ₂ is a C ₁ -C ₁₀ alkyl group, C ₆ -C ₂₀ aryl group, C ₁ -C ₁₀ alkyl substituted C ₆ -C ₂₀ aryl Is selected from a group and _{an aralkyl group of C 6} -C ₂₀ , n is an integer of 1 to 20, and in Chemical Formula 5, R ₃ is the following Chemical Formula 4.)

[Formula 4]

(R ₄ in Formula 4 is C ₂ -C ₁₀ alkylene, R ₅ and R ₆ is hydrogen; C ₁ -C ₁₀ alkyl group, and a halogen group is selected from a _{substituted C 1} -C _{10 alkyl group, R 7} is a C ₁ -C ₁₀ alkyl group.)

Another aspect of the present invention provides an epoxy composition comprising an epoxy resin, a curing agent, and the modified epoxy resin.

The epoxy resin composition includes an epoxy resin and a curing agent. It can be seen that the glycidyl group of the epoxy resin is crosslinked with functional groups such as amines and hydroxyl groups of the curing agent to increase durability and chemical resistance.

In one aspect of the present invention, the epoxy resin is not limited as long as it is a conventional epoxy resin, and specifically, for example, including any one or two or more compounds selected from the group consisting of bisphenol type epoxy and novolac type epoxy. , In preparing an epoxy composition.

More specifically, the epoxy resin is bisphenol A epoxy (BPA-Epoxy), bisphenol F epoxy (BPF-Epoxy), bisphenol S epoxy (BPS-Epoxy), bisphenol AD epoxy (BPAD-Epoxy), bisphenol M epoxy (BPM). -Epoxy), Phenol Novolac Epoxy, Cresol Novolac Epoxy, BPA Novolac Epoxy, Rubber Modified Epoxy, Fatty Acid Modified Epoxy, Urethane Modified Epoxy and Silane Modified Epoxy Any one or two or more selected from may be included.

In one aspect of the present invention, the curing is not limited as long as it is a curing agent commonly used in an epoxy resin, but specifically, for example, selected from the group consisting of an aliphatic amine curing agent, an alicyclic amine curing agent, an aromatic amine curing agent, and an acid anhydride curing agent. It may include any one or two or more compounds.

More specifically, for example, diethylene triamine (DETA), triethylene tetramine (TETA), diethylamino propyl amine (DEAPA), menthane diamine (MDA), In the group consisting of N-aminoethyl piperazine (N-AEP), meta-xylene diamine (MXDA), isophorone diamine (IPDA) and dicyandiamide (DICY) At least one selected amine-based curing agent may be used, but is not limited thereto.

The curing agent may be used in an appropriate amount, but preferably, based on 100 parts by weight of the epoxy resin, the curing agent is used in an amount of 0.1 to 50 parts by weight, more preferably 15 to 40 parts by weight, and even more preferably 20 to 35 parts by weight. I can.

In one aspect of the present invention, the modified epoxy resin contained in the epoxy composition contains phosphorus-based flame-retardant polyol among the components to increase the flame retardancy of the epoxy composition.

The modified epoxy resin may be used in an appropriate amount, but preferably, based on 100 parts by weight of the epoxy resin, the modified epoxy resin is 1 to 50 parts by weight, more preferably 1 to 25 parts by weight, more preferably 5 to It can be used in 15 parts by weight.

When a cured product is prepared by curing the epoxy resin composition at 80° C. for 1 hour in the range where the content of the modified epoxy resin is used in the above range, the mechanical strength is not significantly lowered compared to the case of adding a conventional flame retardant. It is possible to provide a cured body excellent in flame retardancy without.

Specifically, the mechanical strength of the cured product may satisfy Equations 1 to 3 below, and flame retardancy may satisfy Equations 4 and 5 below.

[Equation 1]

(TS ₀ -TS ₁ )/TS ₁ × 100 ≤ 5

In Equation 1, TS ₀ is the tensile strength measured according to ASTM D638 of the epoxy resin composition not containing the modified epoxy resin, and TS ₁ is the tensile strength of the epoxy resin composition containing the modified epoxy resin based on ASTM D638. It is the measured tensile strength.

When the modified epoxy resin is included in an amount of 1 to 50 parts by weight as in Equation 1, the tensile strength of the cured epoxy resin is not significantly reduced, and specifically 5% or less, more specifically 4.5% or less, more specifically 1 to 5% It was confirmed that it was satisfied. It can be seen that the tensile strength does not significantly decrease in this range.

[Equation 2]

(MS ₁ -MS ₀ )/MS ₀ × 100 ≥ 1

In Equation 2, MS ₀ is the flexural strength measured according to ASTM D790M of the epoxy resin composition not containing the modified epoxy resin, and MS ₁ is measured according to ASTM D790M of the epoxy resin composition containing the modified epoxy resin. It is the obtained flexural strength.

When the modified epoxy resin of the above range is used, the value of Equation 2 for the flexural strength may be 1% or more, more specifically 3% or more, more specifically 1-5%, and thus It can be seen that the flexural strength is improved.

[Equation 3]

(PS ₀ -PS ₁ )/PS ₁ × 100 ≤ 12

In Equation 1, PS ₀ is the impact strength measured according to ASTM D 256 of the epoxy resin composition not containing the modified epoxy resin, and PS ₁ is the ASTM D 256 of the epoxy resin composition containing the modified epoxy resin. It is the impact strength measured according to the criteria.

When the modified epoxy resin of the above range was used, the value of Equation 3 for the impact strength may be 12% or less, more specifically 11% or less, and more specifically 1-10%. It can be seen that the impact strength does not significantly decrease in this range.

[Equation 4]

(HS ₀ -HS ₁ )/HS ₀ × 100 ≥ 35

In Equation 4, HS ₀ is the maximum heat release rate of the epoxy resin composition not containing the modified epoxy resin, and HS ₁ is the maximum heat release rate of the epoxy resin composition containing the modified epoxy resin.

When the modified epoxy resin of the above range is used, the value of Equation 3 for the maximum heat release rate may satisfy 35% or more, more specifically 40% or more, and more specifically 35-50%, thereby improving flame retardancy. I can confirm.

[Equation 5]

(RS ₀ -RS ₁ )/RS ₀ × 100 ≥10

In Equation 5, RS ₀ is the maximum heat release amount of the epoxy resin composition not containing the modified epoxy resin, and RS ₁ is the maximum heat release amount of the epoxy resin composition containing the modified epoxy resin.

When the modified epoxy resin of the above range is used, the value of Equation 4 for the maximum heat release may be 10 or more, more specifically 15% or more, and more specifically 10 to 50%, and it can be confirmed that flame retardancy is improved accordingly have.

As the epoxy cured product according to an aspect of the present invention contains the modified epoxy resin, flame retardancy is greatly improved and mechanical properties are not significantly reduced compared to the epoxy cured product prepared by reacting only the epoxy resin and the curing agent without including the modified epoxy resin Can be maintained without.

Hereinafter, examples will be described in detail to describe the present invention in detail. However, the embodiments according to the present invention may be modified in many different forms, and the scope of the present invention should not be construed as being limited to the embodiments described below. Embodiments of the present invention are provided to more completely describe the present invention to those with average knowledge in the art.

[Method of measuring properties]

1. Impact strength

The cured product of the epoxy resin composition prepared in Examples and Comparative Examples according to the present invention was measured for impact strength according to ASTM D 256 using an Izod type impact tester (JJHBT-6501, JJ-test).

2. Tensile strength

The cured product of the epoxy resin composition prepared in Examples and Comparative Examples according to the present invention was measured for tensile strength according to ASTM D 638 using a universal testing machine (UTM 5982, INSTRON).

3. Flexural strength

The cured product of the epoxy resin composition prepared in Examples and Comparative Examples according to the present invention was measured for flexural strength according to ASTM D 790M using a universal testing machine (UTM 5982, INSTRON).

4. Investigation of flame retardancy

The maximum heat release rate (HRR) and total HR value of the cured product of the epoxy resin composition prepared in the Examples and Comparative Examples according to the present invention are the pyrolysis combustion flow calorimeter developed by Lyon and Walters ( PCFC) tester. PCFC puts the sample on the pyrolyser and heats it from 100℃ to 900℃ at a rate of 1℃/s in a nitrogen atmosphere for pyrolysis, and is sent to a combustor at 900℃ where a mixed gas of nitrogen and oxygen exists for complete combustion. At this time, the amount of oxygen consumed _{was measured by an O 2} analyzer, and the maximum heat release rate (HRR) was measured based on this.

[Example 1]

1) Preparation of reactive phosphorus-based flame retardant polyol

[Scheme 1]

In a reactor, phenyl phosphonic dichloride (PPDC) and ethylene glycol (EG) were mixed in a molar ratio of 1:1.8, and dissolved in dichloromethane (MC) so that the solid content thereof was 20% by weight. While stirring this for 24 hours, the inside of the reactor was replaced with nitrogen for 30 minutes. The polycondensation reaction was carried out while gradually raising the temperature of the reactor from 80°C to 130°C for 2 hours.

In order to purify the result of the reaction after polymerization, it was filtered through a centrifuge and the HCl salt was removed by adding pyridine. Thereafter, impurities were removed by solvent extraction with water and dichloromethane solution. The solution from which impurities have been removed was washed with an ether solvent and then dried in vacuo to recover a reactive phosphorus-based flame-retardant polyol.

2) Synthesis of modified epoxy resin

[Scheme 2]

In a 4-neck flask equipped with a stirrer, reflux condenser, nitrogen introduction, thermometer and dropping funnel, the reactive phosphorus-based flame-retardant polyol (MW 1,313 g/mol, 100 g, 0.076 mol) synthesized in Preparation Example 1 and bisphenol F epoxy resin ( MW 370g/mol.56g, 0.15mol) was added. The temperature was slowly raised to 120°C while stirring slowly under nitrogen conditions. Thereafter, 0.5 g of tetrabutylammonium iodide was added and stirred for 1 hour to complete the reaction, and the prepared modified epoxy resin was confirmed by FT-IR of FIG. 1. A hydroxyl group (-OH) groups of the flame retardant polyol becomes three, the strength of the result, a peak of 3384cm ^-1 in the reaction it was found that it has moved to 3515cm ^-1. In particular, it was found that in the bisphenol F epoxy resin, ^{the intensity of the epoxy hydroxyl group from 3515cm -1} , which is the same region, increased significantly as the hydroxyl group (-OH) group generated as a result of the reaction increased. In addition, the epoxy equivalent value was titrated by the STM D 1652 method, and the measured equivalent value was confirmed to be 964 g/eq.

3) Epoxy cured product manufacturing

In order to analyze the physical properties and flame retardancy of the epoxy composition, the epoxy resin, the curing agent and the modified epoxy resin (flame retardant epoxy resin) were mixed.

With respect to 100 parts by weight of the epoxy resin (di-glycidylether of bisphenol A (DGEBA, EPIKOTE 828)) manufactured by Mometiv having an epoxy equivalent of 187 g/eq, the curing agent (Jeffamine di-230 (Jeffamine The epoxy resin composition was prepared by adding 32 parts by weight of D-230 (Kukdo Chemical Co., Ltd.)) and 5 parts by weight of the modified epoxy resin prepared above and stirring using a mechanical overhead stirrer. The resin composition was cured at 80° C. for 1 hour using a mold to prepare a cured product.

The mechanical properties of the prepared cured product are described in Table 1 below, and the numerical values for measuring the flame retardancy are listed in Table 2 below.

[Example 2]

When preparing the epoxy resin composition in 3) of Example 1, it was carried out in the same manner, except that 10 parts by weight of the modified epoxy resin was added.

[Example 3]

When preparing the epoxy resin composition in 3) of Example 1, it was carried out in the same manner, except that the modified epoxy resin was added in an amount of 15 parts by weight.

[Comparative Example 1]

When preparing the epoxy resin composition in 3) of Example 1, it was carried out in the same manner, except that the modified epoxy resin was not included.

Mechanical strength measurement Impact strength (J/m) Tensile strength (MPa) Flexural strength (MPa) Example 1 42.5 65.8 102.0 Example 2 40.6 68.4 101.9 Example 3 39.7 67.0 103.4 Comparative Example 1 44.5 68.7 98.6

Flame retardancy measurement HRR(W/g) Total HR(kJ/g) Example 1 406.7 23.4 Example 2 318.7 21.1 Example 3 289.9 19.2 Comparative Example 1 628.9 26.1

As shown in Table 1, it was confirmed that there was not much change in the impact strength of the epoxy cured product according to the amount of the modified epoxy resin in the cured product of the epoxy resin composition prepared in Example.

In addition, when comparing the measured values of the tensile strength and flexural strength of the cured epoxy product, the flexural strength tended to gradually increase as the flame-retardant modified epoxy was added.

When comparing the measured values of the tensile strength and flexural strength of the cured epoxy product, it was determined that the resulting values for the impact strength and the tensile strength vary, but the values do not change significantly within the error range.

As shown in Table 2, the weight of the modified epoxy resin contained in the epoxy resin composition in the evaluation of the flame retardancy of the epoxy resin composition prepared in the example

It was confirmed that the maximum heat release rate (HRR) value and the total heat release amount (Total HR) value decreased with increasing. The maximum heat release rate (HRR) defines the amount of instantaneous heat generated per sample surface area. The higher the maximum heat release rate (HRR), the size of the fire and the radiant heat flow rate increase. As the weight of the modified epoxy resin increased, it was possible to confirm a lower maximum heat release rate (HRR) of about 1.5 to 2 times in the case of the example than the conventional epoxy resin (Comparative Example 1).

Therefore, it was shown that the flame retardant properties were remarkably improved according to the content of the modified epoxy prepared above.

In conclusion, it was confirmed that the epoxy cured product maintained physical properties such as impact strength, tensile strength, and flexural strength as the modified epoxy resin was added, while increasing the flame retardant effect.

Until now, specific examples of the reactive phosphorus-based flame-retardant polyol synthesis method, the reactive phosphorus-based flame-retardant polyol, and the modified epoxy resin thereof according to an embodiment of the present invention have been described, but within the limits not departing from the scope of the present invention, various It is obvious that various implementation variations are possible.

Therefore, the scope of the present invention should not be defined by being limited to the described embodiments, and should not be defined by the claims to be described later, but also by the claims and equivalents.

That is, the above-described embodiments are illustrative in all respects and should be understood as not limiting, and the scope of the present invention is indicated by the claims to be described later rather than the detailed description, and the meaning and scope of the claims and All changes or modified forms derived from the equivalent concept should be construed as being included in the scope of the present invention.

Claims (12)

A modified epoxy resin prepared by reacting a phosphorus-based flame-retardant polyol of Formula 1 and an epoxy compound.
[Formula 1]

(In Formula 1, R ₁ is a C ₂ -C ₁₀ alkylene group, R ₂ is a C ₁ -C ₁₀ alkyl group, C ₆ -C ₂₀ aryl group, C ₁ -C ₁₀ alkyl substituted C ₆ -C ₂₀ It is selected from an aryl group and a C ₆ -C ₂₀ aralkyl group, and n is an integer of 1 to 20.)
The method of claim 1,
The phosphorus-based flame-retardant polyol of Chemical Formula 1 is a modified epoxy resin having the structure of Chemical Formula 2.
[Formula 2]

The method of claim 1,
The epoxy compound is a modified epoxy resin that is any one or two or more compounds selected from the group consisting of bisphenol type epoxy and novolak type epoxy. The method of claim 3,
The epoxy compound is a modified epoxy resin that is a compound of the structure of formula (3).
[Formula 3]

In Formula 3, R ₃ is a structure represented by Formula 4 below.
[Formula 4]

_{R 4} in Formula 4 is C ₂ -C ₁₀ alkylene, R ₅ and R ₆ is selected from hydrogen or a C ₁ -C ₁₀ alkyl group and a halogen group substituted C ₁ -C ₁₀ alkyl group, and R ₇ is a C ₁ -C ₁₀ alkyl group. The method of claim 1,
The modified epoxy resin that the molar ratio of the phosphorus-based flame-retardant polyol and the epoxy-based compound is 1:1.8 to 1:2.5. The method of claim 1,
The modified epoxy resin is a modified epoxy resin that is a compound represented by the following formula (5).
[Formula 5]

_{R 1} in Formula 5 is a C ₂ -C ₁₀ alkylene group, R ₂ is a C ₁ -C ₁₀ alkyl group, C ₆ -C ₂₀ aryl group, C ₁ -C ₁₀ alkyl substituted C ₆ -C ₂₀ aryl group And C ₆ -C ₂₀ is selected from an aralkyl group, n is an integer of 1 to 20, and in Chemical Formula 5, R ₃ is composed of the following Chemical Formula 4.
[Formula 4]

_{R 4} in Formula 4 is C ₂ -C ₁₀ alkylene, R ₅ and R ₆ is hydrogen; C ₁ -C ₁₀ alkyl group, and a halogen group is selected from a _{substituted C 1} -C _{10 alkyl group, R 7} is a C ₁ -C ₁₀ alkyl group. An epoxy composition comprising an epoxy resin, a curing agent, and the modified epoxy resin of any one of claims 1 to 6. The method of claim 7,
The epoxy resin comprises any one or two or more compounds selected from the group consisting of bisphenol type epoxy and novolak type epoxy, epoxy composition. According to claim 7
The curing agent comprises an aliphatic amine curing agent, an alicyclic amine curing agent, an aromatic amine curing agent and an acid anhydride-based curing agent. The method of claim 7,
An epoxy composition comprising 1 to 50 parts by weight of the modified epoxy resin based on 100 parts by weight of the epoxy resin. The method of claim 10,
An epoxy composition that uses 0.1 to 50 parts by weight of a curing agent based on 100 parts by weight of the epoxy resin. An epoxy cured product obtained by curing the epoxy composition of any one of claims 7 to 11.

Images