KR100353008B1 - epoxy material with low-specific weight and high-strength and thereof method for manufacturing - Google Patents

Abstract

The present invention relates to an epoxy-based material having a low specific gravity high strength and a method for manufacturing the same, and a thermosetting epoxy resin; A predetermined amount of an amine curing agent composed of an oxypropylene diamine system; And a low specific gravity additive, which is added at a ratio of 40% by volume to 50% by volume with respect to the epoxy resin addition amount, and has a boro-silicate as a main component and a low specific gravity filler having a hollow shape; It has an epoxy-based material. And a first process of degassing the first mixture formed by mixing the epoxy resin, the low specific additive treated with the coupling agent and the carbon black, and the second mixture mixed with the amine hardener and the dispersant under vacuum. A second process of re-defoaming by mixing the degassed first mixture and the second mixture; A third step of precuring the mixture degassed in the second step into a mold having a predetermined shape and precuring at about 80 ° C. for about 1 hour; A fourth step of postcuring the precured mixture again at about 120 ° C. for about 2 hours; And a fifth process of gradually cooling after post-curing; There is a technical subject to provide a method for producing an epoxy-based material having low specific gravity high strength properties.

Description

Epoxy-based composition having a low specific gravity and high strength and its manufacturing method {epoxy material with low-specific weight and high-strength and approximately method for manufacturing}

The present invention relates to an epoxy-based material and a method for manufacturing the same, and more particularly, an epoxy-based resin is used as a base material, and an additive such as an amine curing agent is appropriately mixed to maintain high strength but exhibit low specific gravity, thereby enabling various applications. The present invention relates to an epoxy-based material having a specific gravity and high strength and a method of manufacturing the same.

Generally, the polymer resin material is slightly different due to the intrinsic properties of the monomers constituting each resin, but is generally relatively hard, light and have good moldability. These synthetic resins have a specific gravity of 1-1.5, heavier than water, and by adding various other materials, specific gravity control and physical properties can be changed. For example, in order to maintain high strength, an inorganic fiber or an inorganic additive is added, and in this case, the specific gravity is increased to about 1.5-2. On the other hand, when the specific gravity is less than 1 by adding a blowing agent or other substances, the strength becomes weak. Therefore, the specific gravity is less than 1 to maintain a low specific gravity and have a high strength properties due to the material properties of the polymer resin itself has a lot of difficulties in manufacturing.

However, it can be seen that the low specific gravity and high strength materials can be applied in various fields. For example, in the case of a vessel, a float ball is installed in the air vent head, which is an external passage of the oil reservoir, to allow the inflow and outflow of air, and to prevent the inflow of external seawater into the oil reservoir. Since the float ball is to be flowed up and down in a floating state on the oil top to operate at the interface between oil and water, it must have oil resistance and water resistance, so the specific gravity should be less than about 0.7 to 0.8. In addition, it must have sufficient strength because it is to be prevented from being broken by the impact during the flow. Therefore, in order to satisfy the above conditions, the float ball is usually made of stainless steel. In addition, the level gauge in the fuel tank or the ball-shaped ball for measuring the quantity of the water tank, etc. also need to maintain a low specific gravity high strength is usually made of a metal material.

However, the low specific gravity high strength material made of a metal material such as the stainless steel float ball is a labor-intensive manufacturing process, and thus requires a large number of workers as well as high manufacturing costs.

In addition, the low specific gravity high-strength materials made of the metal material is not only severe noise due to the impact during operation, but such noise has a problem that causes severe discomfort to the people around.

Accordingly, an object of the present invention is to provide a material having low specific gravity and high strength, and a method of manufacturing the same, based on an epoxy-based synthetic resin, which is easy to manufacture and low in manufacturing cost.

Another object of the present invention is to provide a material having a low specific gravity and high strength with low noise generation and good soundproofing and dustproof properties using a synthetic resin material made of a soft material, and having good soundproofing and dustproof properties.

According to a first aspect of the present invention for achieving the above object, the thermosetting epoxy resin; A predetermined amount of an amine curing agent composed of an oxypropylene diamine system; And a low specific gravity additive, which is added at a ratio of 40% by volume to 50% by volume with respect to the epoxy resin addition amount, and has a boro-silicate as a main component and a low specific gravity filler having a hollow shape. To provide a technical gist.

In addition, the epoxy-based material is a dispersant having a particle size of 0.5 nm to 4 nm in the form of a powder mainly composed of silicon dioxide having a purity of 99% or more, and added about 5 phr to the amount of epoxy resin, epoxy resin and low specific gravity. It further comprises a coupling agent consisting of gamma-aminopropyllanic acid added about 3 phr to the amount of epoxy resin to enhance the adhesive strength of the additive, and carbon black added about 3 phr to give stability to the pigment and light. It is desirable to. The amine curing agent has a basic molecular formula of H ₂ N-CH ₂ -CH (CH ₃ )-(-O-CH ₂ -CH (CH ₃ )-) _X -NH ₂ , the composition of which x is on average about 3.3 D-230 material having an amount of about 20phr to 25phr, or D-400 material having an average of 5.6 x of about 55phr to 65phr, or D-2000 having an average of about 33 D-400 is mixed in a ratio of about 1-2: 9-10 or 1-2: 4-5, and the total amount is 50phr to 60phr, or about 25phr to 35phr of T-403 material consisting of tertiary amine Be one of the things made of sheep.

According to a second aspect of the present invention, a first mixture comprising a mixture of an epoxy resin, a low specific additive treated with a coupling agent and carbon black, and a second mixture containing an amine curing agent and a dispersant are degassed under vacuum. First course; A second process of re-defoaming by mixing the degassed first mixture and the second mixture; A third step of precuring the mixture degassed in the second step into a mold having a predetermined shape and precuring at about 80 ° C. for about 1 hour; A fourth step of postcuring the precured mixture again at about 120 ° C. for about 2 hours; And a fifth process of gradually cooling after post-curing; There is a technical point to provide a method for producing an epoxy-based material having low specific gravity high strength properties.

Next, an epoxy-based material having a low specific gravity high strength and a method of manufacturing the same according to the present invention having the above characteristics will be described in more detail.

First, the present invention basically provides a material having low specific gravity and high strength properties by adding a curing agent, a coupling agent, a low specific gravity additive, a dispersant, and carbon black to the polymer resin to change the intrinsic properties of the polymer resin, and a method of manufacturing the same. . Hereinafter, each material used in the present invention will be described.

(1) polymer resin

As the polymer material used in the present invention, a thermosetting epoxy resin was used. Since the material having low specific gravity and high strength to be developed in the present invention should have excellent oil resistance and water resistance, a thermosetting resin is more suitable than a thermoplastic, and a usable thermosetting resin can be used. The furnace may be unsaturated polyester resin, vinyl ester, epoxy resin, etc., but epoxy resins having various physical properties are used. Epoxy resins have various types of resins, hardeners, and regulators, have a wide range of material properties, generate less volatiles during hardening, less shrinkage during hardening, and very strong resistance to chemicals and chemical solvents. It has excellent physical properties of adhesion to various additives and fibers. Therefore, in the present invention, a thermosetting epoxy resin having excellent physical property changes according to physical and chemical treatments is used as a base material.

(2) curing agent

Curing agents are important additives in the present invention. Mechanical properties vary considerably depending on the type and amount of hardener. As the curing agent added to the epoxy resin, acid anhydride-based and amine curing agents may be used, but considering the thermal properties, mechanical properties, viscosity in the mixed state, and curing time, amine curing agents are more suitable and hardness among the amine curing agents. It was found that a hydrocarbon system that is easy to control is preferable. The curing agent used used oxypropylenediamine as the main curing agent, and metaphenylenediamine was used for comparative purposes. The curing agent used D-230, D-400, D-2000 and T-403 as the oxypropylene diamine called Huntsmam (Jeffamine) brand name, their basic molecular structure is as follows.

H ₂ N-CH ₂ -CH (CH ₃ )-(-O-CH ₂ -CH (CH ₃ )-) x-NH ₂

X is about 3.3 for the D-230, about 5.6 for the D-400, and about 33.1 for the D-2000. T-403 is composed of a material consisting of tertiary amines unlike the above composition. In addition, each curing agent was used to mix the curing agent in a certain ratio for hardness control, and the curing condition is preferably divided into two times of pre-curing and post-curing. It is to be cured at about 120 ℃ for 2 hours, it is preferable to cool slowly with the oven turned off in order to minimize the residual stress due to heat during cooling.

(3) microsphere fillers

As the low specific gravity additive used in the present invention, it is used for the purpose of reducing specific gravity with an empty sphere type additive mainly composed of bore-silicate called Q-cell. The specific gravity of the additive is about 0.2, the average diameter is 70㎛, and the one having a size distribution of 10㎛ to 150㎛. The usage amount is about 40 to 50% by volume. If too much amount is used, the mechanical properties are deteriorated. If too little amount is used, the specific gravity is not easily reduced. Therefore, the proper use of additives is an important factor, and when added about 45 vol%, the specific gravity is about 0.7, indicating the optimum mechanical properties.

(4) coupling agent

Coupling agent used in the present invention can be used in various ways to improve the adhesion between the epoxy resin and the low specific gravity additive, but mainly used gamma-aminopropyl silane, the amount is about 3phr.

(5) dispersant

In the present invention, the dispersant is for even dispersion of the epoxy resin and the low specific additive. That is, since the low specific gravity additive is added to the epoxy resin having a high specific gravity, phase separation between the resin and the additive occurs due to the difference in specific gravity. If such phase separation occurs, this problem can be solved by using a thickener type dispersant because the physical properties are uneven. Various dispersants may be used, but fumed silicate is used in the present invention. The fume silica used in the present invention is composed of silicon dioxide (SiO ₂ ) as the main component (98.8%), and in powder form, the particle size has a distribution of 0.5 nm to 4 nm and increases the viscosity of the mixture to reduce the fluidity to give a dispersing effect. . It has good dispersing effect, the addition amount is about 5phr, and the decomposition temperature is about 2000 ℃ and higher, which is excellent in thermal properties.

(5) carbon black

In the present invention, carbon black is used as another additive. It is added to give the role of the pigment to give color and stability to ultraviolet or visible light, the amount is about 3phr.

(6) defoamer

Bubbles generated during the reaction of the mixture include bubble removal by chemical method and bubble removal by physical method. As the chemical method, acrylic polymers, vinyl polymers, polyesters, amine phosphates and the like can be generally used, and physical methods can be removed by mechanical stirring. In the present invention, it is preferable to remove by a physical method rather than a chemical method. The antifoaming effect by the chemical method and the physical method is similar to each other, and the antifoaming agent by the chemical method caused a swelling phenomenon during the curing of the epoxy mixture due to the added antifoaming agent, and the degree was proportional to the amount of the antifoaming agent. In addition, since the viscosity of the epoxy mixture is not high in the present invention, it is possible to remove bubbles to some extent without chemical treatment. Therefore, the method by mechanical agitation seems to be valid rather than the bubble removal by the chemical method.

In order to manufacture an epoxy-based material having low specific gravity and high strength properties with the above materials, it was found that the following compositions were most preferable in the present invention after various conditions were changed.

Manufacturing method

In order to prepare a material having low specific gravity and high strength properties with the above composition, an epoxy vacuum injector is used to separate epoxy resin, low specific gravity additive treated with coupling agent, carbon black into one group, and curing agent and dispersant into one group. Defoaming under vacuum. The reason for separating and defoaming as described above is as follows. Epoxy should be heated to reduce the viscosity by applying heat in order to facilitate defoaming. In this case, if degassing by mixing the curing agent and epoxy together, the degassing is carried out because the curing reaction occurs. This is because it is difficult to remove bubbles due to the high viscosity. In addition, the reason why the low specific gravity additive is added to the epoxy is to improve wettability with the epoxy, and if the low specific gravity additive is mixed with a curing agent and degassed, layer separation occurs due to specific gravity difference.

As described above, each of the degassed components separated into two groups is mixed again at an appropriate ratio, and degassed once again, and then injected into a mold into which a desired shape is injected under vacuum. At this time, the bubble is injected in a sufficiently removed state, because the physical properties and appearance are not good if the bubble is not removed.

Next, after pre-curing for about 1 hour at about 80 ℃ in the state injected into the mold, and post-curing for about 2 hours at 120 ℃ again, the specific gravity is about 0.7 To about 0.75, it can be seen that the epoxy-based material having a sufficient strength and mechanical properties.

In addition, the following test method was used to determine the properties of the materials produced by the composition and method as used in the present invention, and the results will be shown.

Test Methods

Tensile, Bending and Compression Tests

In order to test the tensile properties of the epoxy-based material, a dog-bone type specimen was prepared according to the curing agent of each composition and measured using a UTM (Universal Testing Machine, LR10). The cross head speed was 1 mm per minute and the load cell was 10 kN. Tensile specimens were fabricated in the form of general specimens, and three-point flexural strength test specimens were used in accordance with the standard of KSM 3008 (KSM 3008). The load cell of UTM was 10 kN, the crosshead speed was 5 mm per minute, and the span length was 50 mm. Flexural stiffness was measured by the following equation.

Where L is the span length, b is the thickness of the specimen, h is the butterfly of the specimen, F is the load at a randomly selected point of the load-force curve, and Y is the deflection at the load F.

The maximum flexural strength was measured using the following equation.

Izoid Impact Test

For the Izoid impact test, specimens were prepared under conditions such as the type of curing agent and the ratio of the low specific gravity additive, and five or more specimens were tested for each condition.

Drop ball test

The steel surface having a weight of 250 kg was dropped five times to the surface of the specimen at a height of 1 m and the surface of the specimen was examined. And 2.5kg steel ball was dropped five times at 1m height to examine the specimen surface.

Water absorption rate test

Absorption rate test of the specimen under each condition was measured by weight in 24 hours after soaking in water to determine the water absorption rate.

Three specimens were measured per condition. When measuring the compressive strength, the test speed (testspeed) was 2mm per minute. The maximum load was measured up to 900kg, and the deflection amount was calculated by maintaining the load of 350kg for 10 minutes.

According to the test as described above according to the various ratios of each material, the most preferred addition amount and the physical properties according to the following table was shown.

Table 1: Tensile Properties of Epoxy Resin According to the Type and Ratio of Curing Agent

The numbers in parentheses in the table indicate the standard deviation according to the experiment. (The standard deviation is also shown in the following table.) The results of the experiment with the composition shown in Table 1 are shown in the table below.

Table 2: Flexural Strength of Epoxy Resin According to the Type and Ratio of Curing Agent

Table 3: Tensile Properties of Epoxy Resin with Addition of Low Specific Gravity Additives

In general, low specific gravity additives are difficult to use because their specific gravity decreases as the amount of the additive is increased, but mechanical properties are also reduced. However, as shown in Table 3, despite the addition of the low specific gravity additive, it can be seen that the physical properties similar to the case without addition of the low specific gravity additive of Table 1. That is, in the present invention, when the amount of the low specific gravity additive is about 45 vol%, it exhibits similar mechanical properties as when not added, and the specific gravity is also about 0.7-0.75 which is less than 1 required for the present invention. When the amount of the low specific gravity additive was added to 50vol% or more, it was found that the mechanical properties were lowered, and the conditions of low specific gravity could not be satisfied at 40vol% or less.

Table 4: Kinds and Ratio of Curing Agents Flexural Strength of Epoxy Resin with Addition of Low Specific Gravity Additives

As shown in Table 4, when the amount of the low specific gravity additive is about 45 vol%, it can be seen that it is almost similar to the bending strength of Table 2 without the addition of the low specific gravity additive.

Table 5: Impact Energy of Epoxy Resin According to Kinds and Ratio of Curing Agents and Low Specific Gravity Additives

As shown in Table 5, it can be seen that all the curing agents except mPDA have sufficient impact energy.

Table 6: Compressive Strength of Epoxy Resins According to Types and Ratios of Curing Agents and Low Specific Gravity Additives

It can be seen that they exhibit sufficient compressive strength for all hardeners.

What is shown in the said table above shows the optimal compounding ratio and the quantity of a low specific gravity additive according to the kind of basic hardening | curing agent. In addition, when examining the thermal properties according to the ratio of the curing agent as described above, it was found that the composition of D-230 and T-403 added at 80 ° C. was the best and the hardness was also excellent. Finally, in all conditions, the water absorption rate was less than 0.1%, indicating that there was no problem.

As described above, it can be seen that by incorporating various additives in the epoxy resin according to the present invention, a material having low specific gravity with sufficient mechanical properties is produced. Therefore, it can be seen that the resin material having such low specific gravity and high strength properties can be applied to various fields because it can replace the conventional stainless metal material.

As described above, according to the present invention, it is possible to manufacture a material having low specific gravity and high strength properties by blending a variety of additives to the polymer resin, it is possible to mass production with a small manpower, thereby reducing the manufacturing cost It has an effect.

In addition, the material according to the present invention is made of a synthetic resin instead of a metal, there is another effect of improving the soundproofing and dustproofing properties as well as the generation of noise during shock during use.

Claims (6)

delete Thermosetting epoxy resins; A predetermined amount of an amine curing agent composed of an oxypropylene diamine system; A low specific gravity additive which is added at a ratio of 40% by volume to 50% by volume with respect to the epoxy resin addition amount, and comprises a spherical low specific gravity filler having a boro-silicate as a main component and having an empty interior; A dispersant having a particle size of 0.5 nm to 4 nm in the form of a powder mainly composed of silicon dioxide having a purity of 99% or more, and adding about 5 phr to the amount of epoxy resin; A coupling agent composed of gamma-aminopropyllanic acid added in an amount of about 3 phr to the amount of epoxy resin to enhance adhesion between the epoxy resin and the low specific additive; Epoxy-based composition having a low specific gravity high strength, characterized in that it further comprises a carbon black added about 3 phr to impart stability to the pigment and light. The amine curing agent according to claim 1 or 2, wherein the amine curing agent has a basic molecular formula of H ₂ N-CH ₂ -CH (CH ₃ )-(-O-CH ₂ -CH (CH ₃ )-) _X -NH ₂ . Wherein the composition consists of about 20 phr to about 25 phr of D-230 material having an average of about 3.3, or about 55 phr to about 65 phr of D-400 material having an average of about 5.6, or D-2000 having an average of about 33 and D-400 are mixed in a ratio of about 1-2: 9-10 or 1-2: 4-5, and the total amount is 50 phr to 60 phr or tertiary amine. Epoxy-based composition having a low specific gravity high strength properties, characterized in that the T-403 made of any one of those consisting of about 25phr to 35phr amount. A first process of degassing the first mixture formed by mixing the epoxy resin, the low specific additive treated with the coupling agent and the carbon black, and the second mixture mixed with the amine hardener and the dispersant under vacuum; A second process of re-defoaming by mixing the degassed first mixture and the second mixture; A third step of precuring the mixture degassed in the second step into a mold having a predetermined shape and precuring at about 80 ° C. for about 1 hour; A fourth step of postcuring the precured mixture again at about 120 ° C. for about 2 hours; And A fifth process of gradually cooling after post-curing; Method for producing an epoxy-based composition having a low specific gravity high strength properties, characterized in that made. The method of claim 4, wherein the coupling agent is composed of gamma-aminopropyllanic acid, added about 3phr relative to the amount of epoxy resin, The low specific gravity additive is added in a ratio of 40% by volume to 50% by volume with respect to the epoxy resin addition amount, and is composed of a low specific gravity filler having a boro-silicate as a main component and having an empty inside. The carbon black is a method for producing an epoxy-based composition having a low specific gravity high strength properties, characterized in that about 3phr is added in order to give a color pigment role and stability to light. According to claim 4 or 5, wherein the dispersing agent, in the form of a powder mainly composed of silicon dioxide of 99% or more purity having a particle size of 0.5nm to 4nm is added about 5phr relative to the amount of epoxy resin, The curing agent has a basic molecular formula of H ₂ N-CH ₂ -CH (CH ₃ )-(-O-CH ₂ -CH (CH ₃ )-) _X -NH ₂ , the composition of which x is an average of about 3.3. The D-230 material in an amount of about 20 phr to 25 phr, or the D-400 material in which x has an average of 5.6 in an amount of about 55 phr to 65 phr, or the x having an average of about 33 -400 is mixed in a ratio of about 1-2: 9-10 or in a ratio of 1-2: 4-5, and the total amount is 50 phr to 60 phr or about 25 phr to 35 phr of T-403 material consisting of tertiary amine Method for producing an epoxy-based composition having a low specific gravity high strength properties, characterized in that any one consisting of.