KR102223386B1 - Epoxy resin compositions containing phosphorus-based polyols, one-component type epoxy-based adhesive and manufacturing method thereof - Google Patents

Abstract

It is an object of the present invention to provide a one-component type epoxy structural adhesive capable of controlling the flame retardancy and impact resistance of an epoxy adhesive by controlling the content of phosphorus-based polyols, and a method for manufacturing the same. The present invention provides an epoxy resin composition comprising: an epoxy resin; and phosphorus-based polyols represented by chemical formula 1.

Description

An epoxy resin composition containing a phosphorus polyol, a one-component epoxy structural adhesive, and a method for manufacturing the same

The present invention relates to an epoxy resin composition comprising a phosphorus polyol, a one-component epoxy structural adhesive, and a method for manufacturing the same, and more particularly, to an epoxy resin composition comprising a phosphorus-based polyol capable of controlling flame retardancy and impact resistance, one component epoxy structure It relates to an adhesive and a method of manufacturing the same.

Compared with other resins, epoxy resins have excellent physical properties such as adhesion to various substrates, heat resistance, chemical resistance, electrical properties and mechanical properties, and are used as adhesives due to easy control of properties.

In general, epoxy adhesives are classified into two-component or one-component types depending on the storage type. The two-component epoxy adhesive is mixed with an appropriate amount of an epoxy resin and a curing agent immediately before use, and the one-component epoxy adhesive is stored in a state where an epoxy resin and a curing agent are mixed, so it can be used immediately without additional treatment.

The two-part type epoxy adhesive is difficult to store or handle, there is a possibility of measurement error, and the efficiency of the operation is deteriorated. Therefore, a one-component epoxy adhesive in which an epoxy resin and a curing agent are mixed in advance is usually preferred. The one-component epoxy adhesive cures by undergoing a crosslinking reaction through heating, and usually requires a temperature of 120°C or higher.

On the other hand, the epoxy resin is used in combination with an appropriate amount of a curing agent, a curing accelerator, a rubber component for improving properties, as well as a flame retardant. In general, a flame retardant such as a phosphorus-based flame retardant or a halogen-based flame retardant may be used for a synthetic resin molding that requires flame retardancy. These flame retardants are required to be resistant to heat when a synthetic resin is molded or molded, and not to impair the original performance of the synthetic resin such as water resistance and physical properties.

However, since most of the phosphorus-containing compounds used as flame retardants to date are additive-type flame retardants, there are disadvantages such as impairing the physical properties of synthetic resins or deteriorating stability and water resistance. In addition, since most of the phosphorus-containing compounds used as additive flame retardants have poor compatibility with resins, it is difficult to mix them uniformly in the resin. There was.

In order to solve this problem, the present inventors synthesized a reactive phosphorus polyol with a phosphorus compound, and when preparing an epoxy adhesive by mixing the phosphorus polyol with an epoxy resin, the present invention was completed by revealing excellent flame retardancy and impact resistance. .

Republic of Korea Patent Publication No. 10-2009-0039473 (published on April 22, 2009)

An object of the present invention is to provide a one-component epoxy structural adhesive capable of controlling the flame retardancy and impact resistance of an epoxy adhesive by controlling the content of the phosphorus polyol and a method of manufacturing the same.

Another object of the present invention is to provide a one-component epoxy structural adhesive capable of solving problems such as insolubility, elution, and reduction of mechanical properties of existing additive-type flame retardants by adding a reactive phosphorus polyol as a flame retardant.

In order to solve the above problems, the present invention is an epoxy resin; And it provides an epoxy resin composition comprising a; and a phosphorus-based polyol represented by the formula (1).

[Formula 1]

Here, R is a C4-C10 alkyl group, a C6-C20 aryl group, an alkyl substituted C6-C20 aryl group or a C6-C20 aralkyl group, and n is an integer of 1 to 10.

The content of the phosphorus polyol represented by Formula 1 may be 2 to 10 phr compared to the content of the epoxy resin.

The epoxy resin is composed of a bisphenol A type epoxy resin, a bisphenol F type epoxy resin, a trifunctional or higher polyfunctional epoxy resin, a rubber modified liquid epoxy resin, a urethane modified liquid epoxy resin, an acrylic modified liquid epoxy resin, and a photosensitive liquid epoxy resin. It may be one or more selected from the group.

According to another aspect of the present invention, an epoxy resin composition; It provides a one-component epoxy structural adhesive containing; and a curing agent.

The curing agent may be one or more selected from the group consisting of phenol novolac, cresol novolak, bisphenol A novolac, and naphthalene type.

The equivalent ratio of the curing agent and the epoxy resin composition may be 0.5-3:1.

At least one curing accelerator selected from the group consisting of amine-based, phenol-based and imidazole-based compounds may be further included, and the curing temperature may be 160 to 220°C.

According to another aspect of the present invention, (a) mixing and stirring a phosphorus polyol represented by the following formula (1) and an epoxy resin to synthesize an epoxy resin composition; And (b) curing by adding a curing agent to the epoxy resin composition.

[Formula 1]

Here, R is a C4-C10 alkyl group, a C6-C20 aryl group, an alkyl substituted C6-C20 aryl group or a C6-C20 aralkyl group, and n is an integer of 1 to 10.

In the step (a), the phosphorus polyol represented by Formula 1 may be mixed so that the content of the epoxy resin is 2 to 10 phr.

In step (b), at least one curing accelerator selected from the group consisting of amine-based, phenol-based and imidazole-based compounds may be additionally added.

The curing temperature of the epoxy structural adhesive in step (b) may be 160 to 220 °C.

The one-component epoxy structural adhesive according to the present invention has the advantage of maintaining mechanical properties without worrying about elution by adding a phosphorus-based polyol as a flame retardant.

In addition, according to the manufacturing method of the one-component epoxy structural adhesive according to the present invention, the flame retardancy and impact resistance of the epoxy adhesive can be controlled by adjusting the content of the phosphorus polyol, so that an epoxy adhesive can be manufactured according to the use.

^{1 (a) and (b) show 1} H-NMR spectrum and ³¹ P-NMR spectrum of a phosphorus polyol according to an embodiment of the present invention.
2 is a graph comparing the results of differential scanning calorimetry (DSC) analysis of a one-component epoxy structural adhesive according to an embodiment of the present invention.
3 is a graph comparing the results of dynamic dynamic analysis (DMA) of a one-component epoxy structural adhesive according to an embodiment of the present invention.
4 is a graph showing tan δ (= G″/G′) according to a temperature change of a one-component epoxy structural adhesive according to an embodiment of the present invention.
5 is a stress-strain curves graph of a one-component epoxy structural adhesive according to an embodiment of the present invention.
6 is a graph showing the evaluation result of the lap shear strength of the one-component epoxy structural adhesive according to an embodiment of the present invention.
7 shows a fracture surface after evaluation of the overlap shear strength of the one-component epoxy structural adhesive according to an embodiment of the present invention.
Figure 8 shows the force-time curve of the one-component epoxy structural adhesive according to an embodiment of the present invention.
9 is a graph showing the breakdown energy (Ec) of the one-component epoxy structural adhesive according to an embodiment of the present invention.
10 is a graph showing the result of measuring the heat release rate of the one-component epoxy structural adhesive according to an embodiment of the present invention.
11 is a graph showing a measurement result of total heat released of a one-component epoxy structural adhesive according to an embodiment of the present invention.

In the following description, it should be noted that only parts necessary for understanding the embodiments of the present invention will be described, and descriptions of other parts will be omitted without distracting the gist of the present invention.

The terms or words used in the present specification and claims described below should not be construed as being limited to a conventional or dictionary meaning, and the inventor is appropriate as a concept of terms in order to describe his own invention in the best way. It should be interpreted as a meaning and concept consistent with the technical idea of the present invention on the basis of the principle that it can be defined. Therefore, the embodiments described in the present specification and the configurations shown in the drawings are only preferred embodiments of the present invention, and do not represent all the technical spirit of the present invention, and various equivalents that can replace them at the time of application It should be understood that there may be variations and variations.

Hereinafter, the present invention will be described in detail.

The present invention provides an epoxy resin composition comprising an epoxy resin and a phosphorus polyol represented by the following formula (1).

[Formula 1]

Here, R is a C4-C10 alkyl group, a C6-C20 aryl group, an alkyl substituted C6-C20 aryl group or a C6-C20 aralkyl group, and n is an integer of 1 to 10.

The phosphorus polyol represented by Formula 1 may react with the epoxy resin to effectively increase the flame retardancy of the epoxy resin.

The P=O functional group of phosphate contained in the molecule of the phosphorus polyol represented by Formula 1 provides a flame retardant effect.

According to an embodiment of the present invention, the phosphorus polyol polycondensation of phosphonic dichloride and ethylene glycol represented by the following formula (2) (step 1); Filtering the reaction product of the polycondensation reaction to remove the salt (step 2); Removing impurities of the reactant from which the salt has been removed using an extraction solvent (step 3); And washing the reactant from which the impurities have been removed with an organic solvent and vacuum drying to recover the phosphorus polyol represented by Chemical Formula 1 (Step 4).

[Formula 2]

Here, R is a C4-C10 alkyl group, a C6-C20 aryl group, an alkyl substituted C6-C20 aryl group or a C6-C20 aralkyl group, and n is an integer of 1 to 10.

Phosphonic dichloride represented by Formula 2 is preferably phenyl phosphonic dichloride.

The ethylene glycol is a compound represented by the following formula (3).

[Formula 3]

Phosphoric dichloride and ethylene glycol may be polycondensed to synthesize a phosphorus polyol, and a solution polymerization method may be preferably used.

It is preferable that the phosphenic dichloride and ethylene glycol are solution-polymerized in a dichloromethane solution.

The phosphonic dichloride and ethylene glycol may be polycondensed for 1 to 24 hours under reduced pressure conditions of 600 to 0.01 mmHg at 150 to 300 °C.

In the polycondensation of the phosphonic dichloride and ethylene glycol, a polycondensation catalyst may be additionally added.

As the polycondensation catalyst, a titanium compound, a germanium compound, an antimony compound, an aluminum 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.

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.

The reaction molar ratio of the phosphonic dichloride and the ethylene glycol may be 1:1 to 2.

After the polycondensation reaction, the reaction product may be filtered to remove salts, and impurities may be removed using an extraction solvent. HCl salt may be removed by filtering the reaction product of the polycondensation reaction.

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

The reactant from which the impurities have been removed may be washed with an organic solvent and dried to recover the phosphorus polyol.

The reaction product may be washed with an organic solvent to remove the cyclic aromatic hydrocarbon generated in the polycondensation reaction.

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 dimethyl ether.

The epoxy resin is not particularly limited as long as it contains two or more epoxy groups in the molecule.

Examples of usable epoxy resins include bisphenol A type epoxy resin, bisphenol F type epoxy resin, trifunctional or higher polyfunctional epoxy resin, rubber modified liquid epoxy resin, urethane modified liquid epoxy resin, acrylic modified liquid epoxy resin, and photosensitive liquid epoxy. Resins may be used alone or in combination, and bisphenol A type epoxy resins may be preferably used.

The epoxy resin may be used with an epoxy equivalent of about 100 to 1500 g/eq. Within the above range, the epoxy adhesive has excellent adhesion, maintains a glass transition temperature, and may have excellent heat resistance.

The content of the phosphorus polyol represented by Formula 1 may be 2 to 10 phr compared to the content of the epoxy resin. If the content of the phosphorus polyol is less than 2 phr, the flame retardancy of the epoxy resin cannot be improved, and when the phosphorus polyol is added in excess of 10 phr, the curing density is significantly lowered, resulting in reaction by-products, which may rather reduce the mechanical properties of the epoxy resin. Since it may be, it is preferable to add it within the above range.

The phosphorus polyol represented by Formula 1 may have a weight average molecular weight of 500 to 5000 g/mol.

According to another aspect of the present invention, the present invention is an epoxy resin composition comprising a phosphorus polyol represented by the following formula (1); It provides a one-component epoxy structural adhesive containing; and a curing agent.

Description of the epoxy resin composition overlapping with the above will be omitted.

The curing agent according to the present invention may be appropriately selected and used according to the type of epoxy resin, and may be used without limitation as long as it is commonly used as a curing agent for an epoxy resin.

The polydispersity index (DPI) of the curing agent may be 2 or less, preferably 1 to 1.7, and more preferably 1.1 to 1.5.

What can be used as the curing agent includes a phenol-based curing agent, an anhydride-based curing agent, and a dicyanamide-based curing agent, among which a phenolic curing agent is preferable because it can further improve heat resistance and adhesion.

Non-limiting examples of the phenolic curing agent include phenol novolac, cresol novolak, bisphenol A novolac, naphthalene type, and the like, and these may be used alone or in combination of two or more.

Non-limiting examples of the anhydride-based curing agent include phthalic anhydride, pyromellitic anhydride, trimellitic anhydride, and hexahydrophthalic anhydride. The curing agent may be used alone or in combination of two or more.

The content of the curing agent may be appropriately adjusted according to the content of the epoxy resin. It is preferable to mix and use so that the equivalent ratio of the curing agent and the epoxy resin is 0.5-3:1, and this is to prevent deterioration of molding properties such as workability while further improving heat resistance and adhesive strength.

According to an embodiment of the present invention, a curing accelerator for accelerating the reaction between the epoxy resin composition and the curing agent may be further included.

The curing accelerator may further include a conventional curing accelerator known in the art as necessary.

At this time, the curing accelerator may be appropriately selected and used according to the type of epoxy resin and curing agent. Examples of curing accelerators that can be used include amine-based, phenol-based, and imidazole-based curing accelerators, and more specific examples include organic acids such as boron trifluoride amine complexes, imidazole derivatives, phthalic anhydride and trimellitic anhydride. .

Preferred examples of the curing accelerator may be an imidazole derivative curing accelerator, specifically 1-methylimidazole, 2-methylimidazole, 2-ethyl 4-methyl imidazole, 2-phenylimidazole, 2 -Phenyl 4-methyl imidazole, cyanoethylation derivatives thereof, carboxylic acid derivatives, hydroxymethyl group derivatives, and the like, but are not limited thereto. These curing accelerators may be used alone or in combination of two or more.

The content of the curing accelerator may be 0.005 to 0.05 parts by weight, preferably 0.01 to 0.04 parts by weight, based on 100 parts by weight of the epoxy resin and curing agent mixture.

The epoxy resin composition, curing agent, and curing accelerator according to an embodiment of the present invention may be prepared as an epoxy adhesive by dissolving a solvent and mixing and stirring in a conventional manner.

According to another aspect of the present invention, the present invention comprises the steps of: (a) synthesizing an epoxy resin composition by mixing and stirring a phosphorus polyol represented by the following formula (1) and an epoxy resin; And (b) curing by adding a curing agent to the epoxy resin composition.

[Formula 1]

Here, R is a C4-C10 alkyl group, a C6-C20 aryl group, an alkyl substituted C6-C20 aryl group or a C6-C20 aralkyl group, and n is an integer of 1 to 10.

In step (a), the phosphorus polyol represented by Formula 1 may be included in an amount of 2 to 10 phr compared to the content of the epoxy resin. If the content of the phosphorus polyol is less than 2 phr, the flame retardancy of the epoxy resin cannot be improved, and when the phosphorus polyol is added in excess of 10 phr, the curing density is significantly lowered, resulting in reaction by-products, which may rather reduce the mechanical properties of the epoxy resin. Since it may be, it is preferable to add it within the above range.

The phosphorus polyol represented by Formula 1 may react with the epoxy resin to effectively increase the flame retardancy of the epoxy resin. The P=O functional group of phosphate contained in the molecule of the phosphorus polyol represented by Formula 1 provides a flame retardant effect.

The epoxy resin is not particularly limited and can be used as long as it contains two or more epoxy groups in the molecule.

Examples of usable epoxy resins include bisphenol A type epoxy resin, bisphenol F type epoxy resin, trifunctional or higher polyfunctional epoxy resin, rubber modified liquid epoxy resin, urethane modified liquid epoxy resin, acrylic modified liquid epoxy resin, and photosensitive liquid epoxy. Resins may be used alone or in combination, and bisphenol A type epoxy resins may be preferably used.

What can be used as the curing agent in step (b) is a phenolic curing agent, an anhydride curing agent, and a dicyanamide curing agent, among which a phenolic curing agent is preferable because it can further improve heat resistance and adhesion.

Non-limiting examples of the phenolic curing agent include phenol novolac, cresol novolak, bisphenol A novolac, naphthalene type, and the like, and these may be used alone or in combination of two or more.

Non-limiting examples of the anhydride-based curing agent include phthalic anhydride, pyromellitic anhydride, trimellitic anhydride, and hexahydrophthalic anhydride. The curing agent may be used alone or in combination of two or more.

The content of the curing agent may be appropriately adjusted according to the content of the epoxy resin. It is preferable to mix and use so that the equivalent ratio of the curing agent and the epoxy resin is 0.5-3:1, and this is to prevent deterioration of molding properties such as workability while further improving heat resistance and adhesive strength.

In the step (b), at least one curing accelerator selected from the group consisting of amine-based, phenol-based and imidazole-based compounds may be further included.

According to an embodiment of the present invention, a curing accelerator for accelerating the reaction between the epoxy resin composition and the curing agent may be further included.

The curing accelerator may further include a conventional curing accelerator known in the art as needed.

At this time, the curing accelerator may be appropriately selected and used according to the type of epoxy resin and curing agent. Examples of curing accelerators that can be used include amine-based, phenol-based, and imidazole-based curing accelerators, and more specific examples include organic acids such as boron trifluoride amine complexes, imidazole derivatives, phthalic anhydride and trimellitic anhydride. .

Preferred examples of the curing accelerator may be an imidazole derivative curing accelerator, specifically 1-methyl imidazole, 2-methyl imidazole, 2-ethyl 4-methyl imidazole, 2-phenylimidazole, 2- Phenyl 4-methyl imidazole, cyanoethylation derivatives thereof, carboxylic acid derivatives, hydroxymethyl group derivatives, and the like, but are not limited thereto. These curing accelerators may be used alone or in combination of two or more.

The epoxy resin composition, curing agent, and curing accelerator according to an embodiment of the present invention may be prepared as an epoxy adhesive by dissolving a solvent and mixing and stirring in a conventional manner.

According to the manufacturing method of an epoxy adhesive according to an embodiment of the present invention, there is an advantage in that there is no worry of elution and mechanical properties are maintained by adding a phosphorus-based polyol as a flame retardant. In addition, by controlling the content of the phosphorus-based polyol, the flame retardancy and impact resistance of the epoxy adhesive can be adjusted, so that the epoxy adhesive can be manufactured according to the purpose.

Example

Hereinafter, examples will be described in detail in order to describe the present invention in detail. However, the embodiments according to the present invention may be modified in various other forms, and the scope of the present invention should not be construed as being limited to the embodiments described below. The embodiments of the present invention are provided to more completely describe the present invention to those of ordinary skill in the art.

<Production Example 1> Synthesis of phosphorus polyol

Scheme 1 below shows a process for synthesizing a phosphorus polyol using phenyl phosphonic dichloride (PPDC) and ethylene glycol (EG).

[Scheme 1]

Into the reactor, the molar ratio of phenyl phosphonic dichloride (PPDC) and ethylene glycol (EG) was 1:18, and dissolved in dichloromethane (MC). While stirring this for about 24 hours, the inside of the reactor was replaced with nitrogen for 30 minutes. The polycondensation reaction was performed 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 polymerization reaction, the HCl salt was removed by filtration through a centrifugal separator, and impurities were removed by solvent extraction with water and dichloromethane solution. Was obtained an end product being impurities by the removed solution was washed with ether solvent and then to and dried in a vacuum shown by the formula 4, ¹ H-NMR of this product, ³¹ P-NMR spectrum 1 for (a) and (b ).

[Formula 4]

To measure the molecular weight of the synthesized phosphorus polyol, the hydroxyl value (mgKOH/g), which is one of the terminal group quantification methods, was measured and shown in Table 1 below. The measurement of the hydroxyl value was measured by the ASTM E1899-08 method. The method of measuring the hydroxyl value was calculated by the following equation by reacting an acetylation reagent with a polyol and titrating an excess of acid with 1N-KOH.

Hydroxyl value (mg KOH/g) = 5611N(B-C)/S + acid value

N: Normal concentration of 1N-NaOH aqueous solution

B: Volume of titrant consumed in blank test (ml)

C: Volume of titrant consumed in the main test (ml)

S: the weight of the sample

Molecular weight: 5611×2000/hydroxyl value

sample weight(g) EP1
(ml) EP2
(ml) OH value
(mgKOH/g) MW
(g/mol) One 0.3225 4.0069 9.8597 101.83 1,102 2 0.0465 1.5932 2.5305 113.08 992 3 0.0948 1.6807 3.7448 122.15 919 Average of molecular weight 1004
(±92)

<Production Example 2> Preparation of one-component epoxy structural adhesive

An epoxy adhesive was prepared by mixing an epoxy resin, a curing agent, and a curing accelerator according to the composition shown in Table 2 below.

Kinds Content(g) Epoxy resin BPA epoxy resin 8.93 Urethane modified resin 11.88 Hardener Hardener 0.955 Hardening accelerator 0.082

Experimental example 1: Evaluation of curing behavior of epoxy adhesive

In order to measure the curing behavior of the epoxy adhesive prepared in Preparation Example 2, the calorific value according to the temperature was measured using a differential scanning calorimetry (DSC), Q2000, TA Instruments, and a nitrogen atmosphere (50 ml/min) Performed in. Dynamic DSC was measured at a heating rate of 5°C/min over a temperature range of 100 to 240°C to investigate the curing initiation temperature, curing peak temperature, and calorific value.

2 is a graph comparing the results of differential scanning calorimetry (DSC) analysis of a one-component epoxy structural adhesive according to an embodiment of the present invention.

Referring to FIG. 2, it was confirmed that the curing temperature did not change significantly due to the addition of the phosphorus polyol when comparing the case where the phosphorus polyol was not added and the case was added. In addition, the physical properties (curing temperature) of the existing epoxy resin do not change due to the addition of the phosphorus polyol through the curing reaction of the epoxy resin within a constant temperature range of 160 to 220 ℃ despite the increase in the amount of phosphorus polyol added. I could confirm that.

Experimental example 2: of epoxy adhesive Viscoelasticity Measure

In order to measure the viscoelasticity of the epoxy adhesive prepared in Preparation Example 2, a dynamic mechanical analysis (DMA), Q800, TA Instruments) was used. Measurement conditions are the storage modulus (storage modulus, G′) in the temperature range of 5 to 200°¡ÆC at a temperature rising rate of 5°¡ÆC per minute using a dual cantilever probe, frequency = 1 Hz, amplitude = 10 μ\μm. ) And the loss modulus were observed.

3 is a graph comparing the results of dynamic analysis (DMA) of a one-component epoxy structural adhesive according to an embodiment of the present invention, and FIG. 4 is a graph showing a temperature change of a one-component epoxy structural adhesive according to an embodiment of the present invention. It is a graph showing tan δ (= G″/G′).

Epoxy resin has brittleness, so it is weak against impact and its tensile strength is very low. Referring to FIG. 3, it was confirmed that the storage modulus of the epoxy resin decreased as the content of the phosphorus polyol increased. This means that the curing density of the epoxy after curing decreases as the content of the phosphorus polyol increases, indicating that the brittleness of the epoxy resin can be reduced while increasing the content of the phosphorus polyol.

In practical terms, in kinetics analysis, the glass transition temperature is defined as the part of the peak created by the graph of tan δ. Referring to FIG. 5, it was confirmed that the glass transition temperature of the epoxy resin decreased as the content of the phosphorus-based polyol increased. Accordingly, while increasing the content of the phosphorus polyol, the flexibility of the epoxy resin can also be increased.

Experimental example 3: Measurement of shear adhesion strength of epoxy adhesive

The bonding strength was measured through a single lap shear test of the epoxy adhesive prepared in Preparation Example 2. Specimen specifications and test conditions were performed according to ASTM D-1002 with an adhesive area of 12.5 mm × 25 mm and an adhesive thickness of 200 μm. After evenly applying the adhesive to the joint, a 1.6 mm-thick glass bead (CR340) having a uniform size was used to maintain a constant thickness of the adhesive layer. A clip was used to fix the joint and cured at 170° C. for 40 min. The shear strength test was performed using a universal tensile tester (AG-X, Shimazhu) and a measurement speed of 1.3 mm/min. The maximum stress (strength) was measured, and the average value was taken by performing a total of 5 times.

5 is a graph of stress-strain curves of a one-component epoxy structural adhesive according to an embodiment of the present invention, and FIG. 6 is an overlapping shear strength of a one-component epoxy structural adhesive according to an embodiment of the present invention. (Lap shear strength) is a graph showing the evaluation result, Figure 8 shows the fracture surface after the lap shear strength evaluation of the one-component epoxy structural adhesive according to an embodiment of the present invention.

5 and 6, as a result of measuring the shear bonding strength, it was confirmed that the shear strength increased as the content of the phosphorus polyol increased. Until the phosphorus polyol was added in an amount of 2 to 10 phr compared to the content of the epoxy resin, the shear strength was equal to or higher than that before the phosphorus polyol was added. Therefore, it was confirmed that the adhesion of the epoxy resin can be improved by adding the phosphorus polyol in an appropriate amount to the epoxy resin.

In addition, as shown in FIG. 8, when the fracture surface was observed after the adhesion was measured, when the phosphorus polyol was added at 0 phr, interfacial fracture occurred between the epoxy and the beads, but the content of the phosphorus polyol was 4, 10, 15 phr. As it increased gradually, cohesive failure occurred inside the adhesive. This is believed to be a result of improved interfacial adhesion between the epoxy and the substrate (bead) as the content of the phosphorus component having high polarity increases.

However, when the phosphorus polyol was added in an excess of 15 phr compared to the content of the epoxy resin, the shear strength decreased rather than when the phosphorus polyol was not added, and bubbles were formed on the fracture surface after measuring the adhesion. I could confirm. This is believed to be because the curing density of the epoxy resin is lowered and a _{large amount of reaction by-products (H 2} O) is generated, forming bubbles in the adhesive layer, thereby deteriorating the mechanical properties of the resin. Therefore, it was confirmed that when the phosphorus-based polyol was added within a certain content range, the shear strength could be increased without deteriorating the physical properties.

Experimental example 4: Measurement of impact resistance of epoxy adhesive

Impact resistance was measured through an impact wedge-peel test of the epoxy adhesive prepared in Preparation Example 2. The impact peeling test was measured at room temperature (25° C.) according to the ISO 11343 wedge impact method, and was carried out with an adhesive area of 20 mm × 20 mm and an adhesive thickness of 200 μm. After evenly applying the adhesive to the joint, a test specimen was prepared using a 1.6 mm-thick glass bead (CR340) having a uniform size. The specimen was cured at 170° C. for 40 min.

Figure 8 is a force-time curve of the one-component epoxy structural adhesive according to an embodiment of the present invention, Figure 9 is a graph showing the breakdown energy (Ec) of the one-component epoxy structural adhesive according to an embodiment of the present invention to be.

Referring to FIGS. 8 and 9, it can be seen that the phosphorus polyol exhibits equal or higher impact resistance than when not added as the addition amount of the phosphorus polyol increases until the amount of the phosphorus polyol is added in an amount of 2 to 10 phr compared to the content of the epoxy resin. there was. In addition, it was confirmed that until the phosphorus polyol was added in an amount of 2 to 10 phr compared to the content of the epoxy resin, the same or higher breakdown energy (Ec) was required than when the phosphorus polyol was not added as the amount of phosphorus polyol increased. This phenomenon is considered to be due to the decrease in the curing density of the epoxy as the addition of the phosphorus polyol decreases the brittleness of the epoxy and increases the flexibility.

However, when the phosphorus polyol was added in excess of 15 phr or more, the impact resistance was rather lowered, which lowered the curing density of the epoxy resin and simultaneously _{generated a large amount of reaction by-products (H 2} O), forming bubbles inside the adhesive layer, resulting in mechanical mechanical properties of the resin. This is because it lowers physical properties. Therefore, it was confirmed that when the phosphorus-based polyol was added within a certain content range, the shear strength could be increased without deteriorating the physical properties.

Experimental example 5: Measurement of flame retardant properties of epoxy adhesive

Flame retardant properties of the epoxy adhesive were measured through microcalorimeter measurement of the epoxy adhesive prepared in Preparation Example 2. The microcalorimeter is a measure of the calorific value during combustion, and the higher the calorific value is, the more easily it burns. Therefore, the higher the flame retardant material, the smaller the calorific value and the lower the peak.

10 is a graph showing the result of measuring the heat release rate of the one-component epoxy structural adhesive according to an embodiment of the present invention, and FIG. 11 is a total heat release of the one-component epoxy structural adhesive according to an embodiment of the present invention. This is a graph showing the measurement result of (total heat released).

Referring to FIGS. 10 and 11, it can be seen that as the addition amount of the phosphorus-based polyol increases, the peak of the calorific value appears lower and the total amount of heat emitted decreases. Therefore, it was confirmed that the flame retardant properties of the epoxy resin were improved by the addition of the phosphorus polyol. As the content of the epoxy resin increases, the flame retardancy of the epoxy resin is continuously improved, so the flame retardancy of the epoxy resin can be adjusted by adjusting the content of the phosphorus polyol within a required range.

Until now, specific examples of the epoxy resin composition containing the phosphorus-based polyol, the one-component epoxy structural adhesive, and the method of manufacturing the same according to an embodiment of the present invention have been described, but within the limit not departing from the scope of the present invention, various It is obvious that implementation variations are possible.

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

That is, it should be understood that the above-described embodiments are illustrative in all respects and 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)

Epoxy resin; And a phosphorus-based polyol represented by the following Formula 1; Epoxy resin composition comprising:
[Formula 1]

Here, R is a C4-C10 alkyl group, a C6-C20 aryl group, an alkyl substituted C6-C20 aryl group or a C6-C20 aralkyl group, and n is an integer of 1 to 10. The method of claim 1,
An epoxy resin composition, characterized in that the content of the phosphorus polyol represented by Formula 1 is 2 to 10 phr compared to the content of the epoxy resin. The method of claim 1,
The epoxy resin is composed of a bisphenol A type epoxy resin, a bisphenol F type epoxy resin, a trifunctional or higher polyfunctional epoxy resin, a rubber modified liquid epoxy resin, a urethane modified liquid epoxy resin, an acrylic modified liquid epoxy resin, and a photosensitive liquid epoxy resin. Epoxy resin composition, characterized in that at least one selected from the group. The epoxy resin composition of claim 1; And a curing agent; one-component epoxy structural adhesive containing. The method of claim 4,
The curing agent is a one-component epoxy structural adhesive, characterized in that at least one selected from the group consisting of phenol novolac, cresol novolac, bisphenol A novolac, and naphthalene type. The method of claim 4,
One-component epoxy structural adhesive, characterized in that the equivalent ratio of the curing agent and the epoxy resin composition is 0.5-3:1. The method of claim 4,
One-component epoxy structural adhesive, characterized in that it further comprises at least one curing accelerator selected from the group consisting of amine-based, phenol-based and imidazole-based compounds. The method of claim 4,
One-component epoxy structural adhesive, characterized in that the curing temperature is 160 ~ 220 ℃. (a) synthesizing an epoxy resin composition by mixing and stirring a phosphorus polyol represented by the following formula (1) and an epoxy resin; And
(b) curing by adding a curing agent to the epoxy resin composition;
Method for producing a one-component epoxy structural adhesive comprising:
[Formula 1]

Here, R is a C4-C10 alkyl group, a C6-C20 aryl group, an alkyl substituted C6-C20 aryl group or a C6-C20 aralkyl group, and n is an integer of 1 to 10. The method of claim 9,
In step (a)
A method for producing a one-component epoxy structural adhesive, characterized in that mixing the phosphorus polyol represented by Formula 1 to be 2 to 10 phr relative to the content of the epoxy resin. The method of claim 9,
In step (b)
A method for producing an epoxy structural adhesive, characterized in that at least one curing accelerator selected from the group consisting of amine-based, phenol-based and imidazole-based compounds is additionally added. The method of claim 9,
In step (b)
The method of manufacturing a one-component epoxy structural adhesive, characterized in that the curing temperature of the epoxy structural adhesive is 160 ~ 220 ℃.

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