KR100902305B1 - Transparent Lead Acrylates for Radiation Shielding - Google Patents

Abstract

The present invention relates to the production of X-ray protective material relates to a manufacturing method for containing lead in a transparent acrylic resin at a high concentration by producing a resin in which lead compounds are chemically bonded to a transparent acrylic resin.

X-ray defense, acrylic resins, lead, polymerization, copolymerization, polymers, plastics, monomers

Description

Transparent Lead Acrylates for Radiation Shielding

The present invention relates to an X-ray defense material, and more particularly, to a transparent X-ray defense material and a method of manufacturing the same by incorporating lead having high X-ray absorption rate into an acrylic resin by a chemical bonding method.

Conventionally, lead compounds that are well soluble in acrylic resins have been used to inject lead into acrylic resins. However, even when the lead impregnation concentration is increased, it is difficult to manufacture high concentration transparent lead acrylic resins due to the limitation of solubility of the lead compounds in acrylic resins.

Therefore, the first technical problem to be achieved by the present invention is to provide a high concentration transparent lead acrylic plastic material by chemically bonding a lead compound with a monomer for acrylic polymer synthesis.

The second technical problem to be achieved by the present invention is that the lead compound of the present invention has a self-polymerization reaction at 30 ° C. or higher without an initiator, and thus transparent lead that provides a variety of optical functions and mechanical properties by using this polymerization reaction according to the purpose. It is to provide a method for producing an acrylic resin.

Acrylic monomers used as raw materials are acrylonitrile (CH ₂ = CH-CN), acrylic acid (CH ₂ = CH-COOH), methyl acrylate (CH ₂ = CH-COOCH ₃ ), ethyl acrylate (CH ₂ = CH- COOC ₂ H ₅ ), butyl acrylate (CH ₂ = CH-COOC ₄ H ₉ ), 2-ethyl hexyl acrylate (CH ₂ = CH-COOC ₈ H ₁₇ ), methoxyethyl acrylate (CH ₂ = CH-COOCH ₂ CH ₂ OCH ₃ ), dimethylamino acrylate (CH ₂ = CH-COOCH ₂ CH ₂ N (CH ₃ ) ₂

methacrylic acid {CH ₂ = C (CH ₃ ) -COOH}, methyl methacrylate {CH ₂ = C (CH ₃ ) -COOCH ₃ }, ethyl methacrylate {CH ₂ = C (CH ₃ ) -COOC ₂ H ₅ }, butyl methacrylate {CH ₂ = C (CH ₃ ) -COOC ₄ H ₉ }, isobutyl methacrylate {CH ₂ = C (CH ₃ ) -COOCH ₂ -CH (CH ₃ ) -CH ₃ }, 2-ethylhexyl methacrylate {CH ₂ = C (CH ₃ ) -COOC ₈ H ₁₇ }, allyl methacrylate {CH ₂ = C (CH ₃ ) -COOCH ₂ -CH = CH ₂ },

2-hydroxy ethyl acrylate (CH ₂ = CH-COOCH ₂ -CH ₂ -OH), 2-hydroxy propyl acrylate {CH ₂ = CH-COO-CH ₂ -CH (OH) -CH ₃ }, 2-hydroxy ethyl methacrylate {CH ₂ = C (CH ₃ ) -COOCH ₂ -CH ₂ -OH), 2-hydroxy propyl methacrylate {CH ₂ = C (CH ₃ ) -COO-CH ₂ -CH (OH) -CH ₃ }, acrylamide ( CH ₂ = CH-CONH ₂ ), methacrylamide {CH ₂ = C (CH ₃ ) -CONH ₂ ), mainly acrylic monomers and styrene {CH ₂ = CH- (C ₆ H ₅ )}-based or vinyl chloride (CH ₂ = CHCl) type or vinyl acetate (CH ₂ = CH (OOC-CH ₃ )) type or a copolymer of one or three kinds thereof.

The lead compound uses _two organic carbonates, R ₁ COOH and R ₂ COOH. Here, R ₁ is an alkyl group containing an unsaturated hydrocarbon having one or more double bonds, and may further include a functional group such as an amino group or a hydroxyl group. Examples of R ₁ COOH are as follows.

acrylic acid CH ₂ = CHCOOH,

(E) -but-2-enoic acid CH ₃ CH = CHCOOH

(E) -pent-2-enoic acid CH ₃ CH ₂ CH = CHCOOH

(E) -hex-2-enoic acid CH ₃ CH ₂ CH ₂ CH = CHCOOH

(E) -hept-2-enoic acid CH ₃ CH ₂ CH ₂ CH ₂ CH = CHCOOH

(E) -oct-2-enoic acid CH ₃ CH ₂ CH ₂ CH ₂ CH ₂ CH = CHCOOH

(E) -non-2-enoic acid CH ₃ CH ₂ CH ₂ CH ₂ CH ₂ CH ₂ CH = CHCOOH

(E) -dec-2-enoic acid CH ₃ CH ₂ CH ₂ CH ₂ CH ₂ CH ₂ CH ₂ CH = CHCOOH

As the side chain structure compound

methacrylic acid CH ₂ = C (CH ₃ ) COOH

3-methylbut-2-enoic acid (CH ₃ ) ₂ C = CHCOOH

(E) -2-methylbut-2-enoic acid CH ₃ CH = C (CH ₃ ) COOH

(E) -4-methylpent-2-enoic acid (CH ₃ ) ₂ CHCH = CHCOOH

(E) -3-methylpent-2-enoic acid CH ₃ CH ₂ C (CH ₃ ) = CHCOOH

(E) -2-methylpent-2-enoic acid CH ₃ CH ₂ CH = C (CH ₃ ) COOH

(E) -5-methylhex-2-enoic acid (CH ₃ ) ₂ CHCH ₂ CH = CHCOOH

(E) -4-methylhex-2-enoic acid CH ₃ CH ₂ CH (CH ₃ ) CH = CHCOOH

(E) -3-methylhex-2-enoic acid CH ₃ CH ₂ CH ₂ CH (CH ₃ ) = CHCOOH

(E) -2-methylhex-2-enoic acid CH ₃ CH ₂ CH ₂ CH = C (CH ₃ ) COOH

In the above examples, the double bond sites are all located at the carbon 2 (α-carbon) position, but other unsaturated hydrocarbons having double bonds at other carbon sites are also possible. Tends to improve transparency.

R ₂ may further include a functional group such as amino group or hydroxide group as a group of saturated hydrocarbons, unlike the same as R ₁ or R _1.

When the gram molecular weights of R ₁ COOH and R ₂ COOH are M ₁ and M ₂ , respectively, lead 2 organic carbonate {Pb (R ₁ COO) (R ₂ COO)} should satisfy the condition shown in Equation 1.

M ₁ + M ₂ -2 ≤ 207.19 (100-W _Pb ) / W _Pb Equation 1

Where W _Pb represents the gram content of lead contained in 100 g of the final resin.

The manufacturing process goes through the following four processes.

 First step: mixing raw materials

 Second Process: Lead Organic Carbonate Manufacturing Process

 3rd process: 1st polymerization process

 4th process: 2nd polymerization process

The lead oxide powder and the liquid of R ₁ COOH and R ₂ COOH are added to a monomer of an acrylic resin, or an acrylic monomer and a styrene or vinyl monomer, or a mixture of one or three kinds thereof. Put in the reaction container as much as lead equivalent and stir well. At this time, lead oxide has a high specific gravity and is easy to sink to the bottom of the container, so stir well and add slowly. In the second step, the turbid liquid of the raw material solution and the lead powder of the first step is heated to 30 to 60 ° C. to accelerate the neutralization reaction of the lead oxide with the organic acid of R ₁ COOH and R ₂ COOH. After the reaction of lead oxide, white lead diorganocarbonate {Pb (R ₁ COO) (R ₂ COO)} precipitates and the formation of sedimentation proceeds to the third process. When producing lead acrylic materials containing 35% or more of lead, finish the second step, add ethyl alcohol, and proceed to the third step to adjust the fluidity of the solution. In the third step, the initiator is added with 0.05 to 0.5% by weight of the final resin and then heated until the viscosity is about 500cp while maintaining the reaction temperature at 40 ℃ ~ 60 ℃. In the fourth step, the viscous resin liquid obtained in the third step is poured into a plate or a desired model to complete the final polymerization reaction in a constant temperature bath at 40 ° C to 70 ° C. In the second step, if the temperature is heated to 40 ° C. to 70 ° C. without an initiator, polymerization of lead diorganocarbonate {Pb (R ₁ COO) (R ₂ COO)} itself and lead diorganocarbonate {Pb (R ₁ COO) ( R ₂ COO)} and the polymerization of the monomers occur at the same time, brown begins to appear, and as the polymerization proceeds, brown becomes dark. The polymerization takes place up to oligomer levels of 200-300 cps and requires an initiator for the final reaction. Lead 2 organic carbonate {Pb (R ₁ COO) (R ₂ COO)} In order to suppress the polymerization reaction between molecules, the reaction is carried out by adding an initiator from the second step. Polymerization reaction between {Pb (R ₁ COO) (R ₂ COO)} and acryl monomer and lead 2 organic carbonate {Pb (R ₁ COO) (R ₂ COO)} occurs simultaneously, leading lead to molecular level in final resin. It can be uniformly distributed to make transparent lead acrylic with good transparency. By adjusting the initiator injection timing, a transparent lead acrylic resin having different transparency and mechanical properties can be made.

Example 1

In a 300 ml glass beaker, put 79 ml of acrylic monomer, methyl methacrylate (MMA), 46 ml of 2-ethyl hexanoic acid, and 25 ml of methacrylic acid into a measuring cylinder, mix, stir well, and weigh 64.63 g of lead oxide on a scale. Sprinkle. Since lead oxide generates heat by neutralizing organic carbonate, the temperature of solution rises from 30 ℃ to 60 ℃. At this temperature, the reaction of lead oxide is promoted, and white lead 2 organic carbonate is formed by precipitation. The carbonate is heated to this temperature for 4 to 6 hours with an electric heater, and the lead organic carbonate reacts with the MMA monomer to form a solution. When the solution is heated again for 4-6 hours in a complete solution state, the solution becomes viscous by polymerization, and when the viscosity reaches about 200 to 300cp, 0.2g of AIBN is added as an initiator and polymerization is continued at 40 to 60 ° C. When the viscosity of the solution is about 500cp, the viscous resin solution is poured into a glass tube with an inner diameter of 2cm and a height of 20cm, and the glass tube is placed in a constant temperature bath maintained at a temperature of 50 ° C to 60 ° C for 10 to 24 hours to complete the polymerization reaction. . After the polymerization of the lead acrylic resin, the glass tube was removed, and then cut to 12 mm in thickness to measure X-ray transmittance. X-rays generated at 70 kV and 60 mA were irradiated for 0.3 seconds on a cut lead acrylic specimen at 1 m of ffd (focus film distance), and then developed and compared with a calibration curve. The lead thickness of lead acrylic resin was 0.55 mm.

Example 2

In a 300 ml glass beaker, put 79 ml of acrylic monomer, methyl methacrylate (MMA), 46 ml of 2-ethyl hexanoic acid, and 25 ml of methacrylic acid into a measuring cylinder, mix, stir well, and weigh 64.63 g of lead oxide on a scale. Sprinkle. Since lead oxide generates heat by neutralizing organic carbonate, the temperature of solution rises from 30 ℃ to 60 ℃. At this temperature, the reaction of lead oxide is promoted, and white lead 2 organic carbonate is formed by precipitation. 0.2 g of AIBN is added to the lead organic acid and MMA monomer mixture as an initiator, followed by heating at 40 to 60 ° C. for 4 to 6 hours. The lead organic carbonate reacts with the MMA monomer to become a solution state. When the solution is heated for 10 to 15 hours in a complete solution state, the viscosity of the solution increases. Pour this glass tube to stand for 10-24 hours in a constant temperature bath maintained at 50 ~ 60 ℃ to complete the polymerization. The lead acrylic resin after polymerization was higher in transparency than the resin of Example 1. This lead acrylic resin was removed by a glass tube and cut into a thickness of 12 mm to measure the X-ray transmittance. X-rays generated at 70 kV and 60 mA were irradiated for 0.3 seconds on a cut lead acrylic specimen at 1 m of ffd (focus film distance), and then developed and compared with a calibration curve. The lead thickness of lead acrylic resin was 0.55 mm.

Example 3

In a 300 ml glass beaker, add 52.19 g of acrylic monomer (MMA), 48.72 g of 2-ethyl hexanoic acid, and 29.1 g of methacrylic acid, mix, and stir well. Sprinkle in solution. Since lead oxide generates heat by neutralizing organic carbonate, the temperature of solution rises from 30 ℃ to 60 ℃. At this temperature, the reaction of lead oxide is promoted, and white lead 2 organic carbonate is formed by precipitation. The carbonate is heated to this temperature for 4 to 6 hours with an electric heater, and the lead organic carbonate reacts with the MMA monomer to form a solution. When the solution is heated again for 4 to 6 hours in a complete solution state, the viscosity of the solution becomes large, and when the viscosity reaches about 200 to 300 cps, 0.2 g of AIBN is added as an initiator and the polymerization is continued at 40 to 60 ° C. When the viscosity of the solution is about 500 cps, the viscous resin solution is poured into a glass tube having an inner diameter of 2 cm and a height of 20 cm, and the glass tube is placed in a constant temperature bath maintained at a temperature of 50 ° C. to 60 ° C. for 10 to 24 hours to complete the polymerization reaction. do. After the reaction, the lead acrylic resin was removed to remove the glass tube and cut to 12 mm in thickness to measure the X-ray transmittance. X-rays generated at 70 kV and 60 mA were irradiated for 0.3 seconds on a cut lead acrylic specimen at 1 m of ffd (focus film distance), and then developed and compared with a calibration curve. The lead thickness of lead acrylic resin was 0.63 mm.

Example 4

In a 300 ml glass beaker, 31 g of acrylic monomer MMA (methyl methacrylate), 55.68 g of 2-ethyl hexanoic acid, and 33.24 g of methacrylic acid are added to the balance, 50 ml of ethyl alcohol is added and mixed, followed by stirring. Weigh in a balance and slowly sprinkle in the mixed raw material solution. Since lead oxide generates heat by neutralizing organic carbonate, the temperature of solution rises from 30 ℃ to 60 ℃. At this temperature, the reaction of lead oxide is promoted, and white lead 2 organic carbonate is formed by precipitation. The carbonate is heated to this temperature for 4 to 6 hours with an electric heater, and the lead organic carbonate reacts with the MMA monomer to form a solution. When the solution is heated again for 4 to 6 hours in a complete solution state, the viscosity of the solution becomes large, and when the viscosity reaches about 200 to 300 cps, 0.2 g of AIBN is added as an initiator and the polymerization is continued at 40 to 60 ° C. When the viscosity of the solution is about 500 cps, the viscous resin solution is poured into a glass tube with an inner diameter of 2 cm and a height of 20 cm, and the glass tube is placed in a constant temperature bath maintained at a temperature of 60 to 65 ° C. for 10 to 24 hours to complete the polymerization reaction. do. After the reaction, the lead acrylic resin was removed to remove the glass tube and cut to 12 mm in thickness to measure the X-ray transmittance. X-rays generated at 70 kV and 60 mA were irradiated for 0.3 seconds on a cut lead acrylic specimen at 1 m of ffd (focus film distance), and then developed and compared with a calibration curve. The lead thickness of lead acrylic resin was 0.70 mm.

The present invention was able to make a transparent lead acrylic resin containing high concentration lead by chemically reacting the monomer of the acrylic resin with lead 2 organic carbonate and then polymerizing it. It is also useful for screen protection screen of computer.

Claims (6)

Lead 2 organic carbonate Pb {(R ₁ COO) (R ₂ COO)} is a transparent lead acrylic resin for X-ray defense chemically bonded with acrylic polymer compound, Wherein R ₁ COO and of the R ₁ is an unsaturated hydrocarbon group having a binding of the at least one second, including the combination of 1 to 2 carbon α position of the group, The X-ray defense transparent lead acrylic resin wherein R ₂ COO R ₂ of the unsaturated hydrocarbon group include a saturated or unsaturated hydrocarbon group, a saturated hydrocarbon group containing the hydroxide group or an amino group, or a hydroxide group or an amino group. The acrylic polymer compound of claim 1 is a transparent lead acrylic resin for X-ray defense, which is mainly composed of an acrylic monomer or an acrylic monomer and a single or mixed monomer of styrene or vinyl monomer as a support material. delete delete In the lead diorganocarbonate (Pb (R ₁ COO) (R ₂ COO)} of claim 1, the gram molecular weights of R ₁ COOH and R ₂ COOH are represented by M ₁ and M ₂ , respectively, and W _Pb is contained in 100 g of the final resin. When expressed in grams of lead M ₁ + M ₂ -2 ≤ 207.19 (100-W _Pb ) / W _Pb Transparent lead acrylic resin for X-ray defense made by satisfying the relational expression. In claim 1, the transparent lead acrylic resin for X-ray The first step: Mainly acryl monomer or acrylic monomer as a water support material, mixed monomer of styrene or vinyl monomer for copolymerization, lead monoxide (PbO) of the desired content, and R ₁ COOH and R ₂ COOH of claim 1, respectively Mixing process in which gram molecular weight, such as lead monoxide, is placed in a reactor and mixed Second step: In a turbid liquid obtained in the first step, add 0.05 to 0.5% by weight of the radical initiator with respect to the final resin, and heat it to 40-60 ° C. to lead diorganocarbonate {Pb (R ₁ COO) (R ₂ COO)} A process for synthesizing the precipitate and obtaining a turbid solution of Pb (R ₁ COO) (R ₂ COO)} and monomers The third step: The turbid liquid of the second step is continuously heated to 40-60 ° C until the viscosity of the solution reaches about 500 cps, and the copolymerized oligomer and lead diorganocarbonate {Pb (R ₁ COO) (R ₂ COO)} process to simultaneously proceed the chemical bonding reaction 4th step: The process of transferring the lead resin liquid obtained in the 3rd process into a shaping | molding die, and continuing to copolymerize and shape | molding until it fully hardens at 40-70 degreeC. Transparent lead-acrylic resin for X-ray defense made by a 4 step process.