JP2014024731A - Borosilicate glass - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a glass in which transparency is high before radiation irradiation, and coloration is hardly caused even after radiation irradiation, and further that is suitable for a medical container.SOLUTION: A borosilicate glass includes, as a glass composition, and by mass% in terms of following oxides, SiO65-78%; BO8-18%, LiO+NaO+KO 1-18%, CeO0.1-5.0%, and SnO0.1-2.0%, and preferably includes SiO65-75%, BO8-18%, LiO+NaO+KO 1-10%, CeO0.1-5.0%, SnO0.1-2.0%, AlO0-10%, CaO 0-7%, BaO 0-5%, LiO 0-5%, NaO 0-10%, and KO 0-5%.

Description

  The present invention relates to a borosilicate glass, and more specifically to a medical borosilicate glass with little coloring after irradiation.

  Conventionally, medical containers such as vials, ampoules, and vacuum blood collection tubes have been subjected to gas sterilization and high-pressure steam sterilization before and after chemical filling for safety and health.

  However, gas sterilization and high-pressure steam sterilization have problems in that control and management of gas and sterilization atmosphere require skill, and the sterilization process tends to be insufficient due to a long sterilization time. In addition, since the inside cannot be sterilized after the container is sealed, a chemical solution filling operation in an aseptic environment is necessary to prevent contamination of fungi at the time of drug filling. The filling of the chemical solution under such an aseptic environment requires a dedicated facility environment, which causes an increase in the manufacturing cost of the pharmaceutical product.

  Under such circumstances, instead of gas sterilization and high-pressure steam sterilization, radiation sterilization in which radiation is sterilized for irradiation has been proposed. In radiation sterilization, radiation such as electron beams and γ rays is generally used, and a large amount of objects can be efficiently sterilized in a shorter time than gas sterilization. In addition, since radiation such as electron beams and γ rays penetrates the container, the inside of the container can be sterilized after filling the container with the medicine. That is, it is not necessary to fill the medicine in an aseptic environment, and the manufacturing cost of the medicine can be reduced.

By the way, it is preferable that a medical container has little coloring of the container itself for the purpose of inspecting the mixing of foreign matters into the container. However, in radiation sterilization, since the energy of radiation is high, there is a problem that a medical container irradiated with radiation is discolored (colored), and visual inspection in the container after sterilization becomes difficult.

In order to solve such a problem, glass with reduced coloring due to radiation has been developed (for example, Patent Document 1). Irradiation discoloration glass disclosed in Patent Document 1, since it contains CeO ₂ 0.1 to 3%, coloration due to the irradiation of radiation is suppressed.

Japanese Patent Laid-Open No. 9-295828

CeO ₂ exists in the state of Ce ³⁺ ions or Ce ⁴⁺ ions in the glass. The Ce ⁴⁺ ions in the glass have the property of coloring the glass yellowish brown. That is, when CeO ₂ is contained as a glass composition, the glass is colored (before irradiation with radiation) at the time when the glass is molded, and the visible light transmittance may be lowered. The initial coloration of the glass due to such composition components remains in the glass even after irradiation. Therefore, even if CeO ₂ is added and discoloration due to radiation irradiation can be suppressed, if the initial coloring is strong, the final glass is strongly colored. That is, in the conventional glass containing CeO ₂ , it may be difficult to perform inspection after radiation sterilization. Hereinafter, the coloring of the glass caused by Ce ⁴⁺ is referred to as initial coloring, and the coloring of the glass caused by radiation irradiation is referred to as radiation coloring.

  The present invention has been made in consideration of such circumstances, and provides a glass that is highly transparent before radiation irradiation, is difficult to be colored after radiation irradiation, and is suitable for medical containers. This is the issue.

As a result of intensive studies, the present inventor has found that the above problems can be solved by strictly defining the glass composition as follows, and proposes the present invention.

Borosilicate glass of the present invention, in mass% terms of oxide as a glass _{composition, SiO 2 65~78%, B 2} O 3 8~18%, Li 2 O + Na 2 O + K 2 O 1~18%, CeO 2 It contains 0.1 to 5.0% and SnO ₂ 0.1 to 2.0%.

Furthermore, borosilicate glass of the present invention, in mass% terms of oxide as a glass _{composition, SiO 2 65~75%, B 2} O 3 8~18%, Li 2 O + Na 2 O + K 2 O 1~10%, _{CeO 2 0.1~5.0%, SnO 2 0.1~2.0} %, Al 2 O 3 0~10%, CaO 0~7%, BaO 0~5%, Li 2 O 0~5% , Na ₂ O 0 to 10%, K ₂ O 0 to 5% is preferable.

In the borosilicate glass of the present invention, the CeO ₂ content is more preferably 1.1 to 5.0%.

The borosilicate glass of the present invention preferably has an absorbance of 0.15 or less before radiation irradiation. The “absorbance” is a value represented by the following formula.
A = Log (1 / T ₅₀₀ )
A: Absorbance T ₅₀₀ : Spectral transmittance at a thickness of 5.0 mm and a wavelength of 500 nm

  The borosilicate glass of the present invention preferably has an absorbance of 0.30 or less after irradiation with radiation at an absorbed dose of 25 kGy.

  The borosilicate glass of the present invention is preferably used in a medical container that is sterilized by radiation. The medical container refers to a medical container filled with a medicine and a medical use container such as a vacuum blood collection tube not filled with the medicine.

  The borosilicate glass of the present invention is preferably used for a vacuum blood collection tube that is sterilized by γ rays or electron beams.

The borosilicate glass of the present invention is preferably used in a pharmaceutical container that is sterilized by γ rays or electron beams. The pharmaceutical container refers to a container filled with a medicine such as a vial bottle or an ampoule tube.

According to the borosilicate glass of the present invention, by containing CeO ₂ , while suppressing coloring due to radiation irradiation, it contains other components in a well-balanced manner before radiation irradiation due to Ce ⁴⁺ ions and the like. Coloring of the glass can also be suppressed. In addition, since the borosilicate glass of the present invention has a basic composition of borosilicate glass with a small amount of alkali elution, it is possible to suppress deterioration of the filled medicine when used as a pharmaceutical container. Therefore, the borosilicate glass of the present invention is suitable as a medical container, and the inside of the container can be easily inspected even after the radiation sterilization treatment.

Hereinafter, the borosilicate glass of embodiment of this invention is demonstrated. First, the effect | action of the component which comprises the glass of this invention and the reason which prescribed | regulated the content as mentioned above are demonstrated. In addition, in description of the containing range of each component,% display points out the mass%.

SiO ₂ is a main component that forms a glass skeleton structure. The content of SiO ₂ is 65 to 78%, preferably 67 to 75%, more preferably 67 to 73%. When the content of SiO ₂ is less than 65%, the mechanical strength of the glass tends to decrease. When the content of SiO ₂ is more than 78%, the viscosity of the glass becomes high, and the meltability and moldability tend to be lowered.

Al ₂ O ₃ is a component that increases the chemical durability and mechanical strength of the glass, and is a component that increases the devitrification resistance of the glass. The content of Al ₂ O ₃ is 0 to 10%, preferably 3 to 10%, more preferably 5 to 9%, 5 to 8%, and 6.5 to 8%. When the content of Al ₂ O ₃ is more than 10%, meltability and formability viscosity of the glass becomes high it is likely to decrease.

B ₂ O ₃ is a component that forms a glass skeleton structure like SiO ₂ , but is a component that lowers the viscosity of glass unlike SiO ₂ . The content of B ₂ O ₃ is 8 to 18%, preferably 8 to 15%, more preferably 8 to 13%. When the content of B ₂ O ₃ is more than 18%, the glass is likely to undergo phase separation. When phase separation occurs in the glass, the chemical durability of the glass tends to decrease. Further, when the content of B ₂ O ₃ is more than 18%, increasing the amount of evaporation of B ₂ O ₃ from the molten glass, liable to lower the homogeneity of the glass is easy to heterogeneous layer formed on the molten glass surface Become. When the content of B ₂ O ₃ is less than 8%, the viscosity of the glass becomes high, and the meltability and moldability tend to decrease.

_Li 2 _O is an alkali metal _oxide, Na _{2 O, K} 2 O reduces the viscosity of the glass is a component for enhancing the meltability and formability. The content of Li ₂ O + Na ₂ O + K ₂ O is 1 to 18%, preferably 1 to 10%, more preferably 5 to 10%, 5 to 9%, and 5 to 8%. When Li ₂ O + Na ₂ O + K ₂ O is less than 1%, the viscosity of the glass increases, and the meltability and moldability deteriorate. If the Li ₂ O + Na ₂ O + K ₂ O content is more than 18%, the chemical durability of the glass decreases, the amount of alkali elution from the glass increases, and precipitates are likely to be generated on the glass surface.

Li ₂ O is a component that lowers the viscosity of the glass and improves meltability and moldability. The content of Li ₂ O is preferably 0 to 5%, more preferably 0 to 4%. When the content of Li ₂ O is more than 5%, crystals containing Li are easily precipitated from the molten glass. Since high Li 2 _O is cost of the raw materials, the content is preferably small.

Na ₂ O is a component that lowers the viscosity of the glass and improves the meltability and moldability. The content of Na ₂ O is preferably 0 to 10%, more preferably 3 to 8%, and 5 to 8%. When the content of Na 2 _O is greater than 10%, the amount of alkali elution from the glass with reduced chemical durability of the glass is increased.

K ₂ O is a component that lowers the viscosity of the glass and improves the meltability and moldability. The content of K ₂ O is preferably 0 to 5%, more preferably 0 to 4%, and 0 to 3%. When the content of K 2 _O is more than 5%, the chemical durability of the glass tends to decrease.

  CaO and BaO, which are alkaline earth metal oxides, are components that lower the viscosity of the glass and increase the meltability and moldability. The content of CaO + BaO is preferably 0.5 to 10%, more preferably 1 to 5%, and 1 to 3%. When CaO + BaO is less than 0.5%, the viscosity of the glass increases, and the meltability and moldability tend to deteriorate. If CaO + BaO is more than 10%, crystals containing Ca or Ba are likely to be precipitated on the glass.

  CaO is a component that lowers the viscosity of the glass and improves meltability and moldability. The content of CaO is preferably 0 to 7%, more preferably 0 to 5%, 0 to 3%, and 0 to 2%. When there is more content of CaO than 7%, the acid resistance of glass will fall easily. Further, crystals containing Ca are likely to precipitate from the glass.

  BaO is a component that reduces the viscosity of the glass and improves the devitrification resistance. The content of BaO is preferably 0 to 5%, more preferably 0 to 3%, and still more preferably 0 to 2%. When there is more content of BaO than 5%, the strain point of glass will fall and heat resistance will deteriorate easily. Further, crystals containing Ba are likely to precipitate from the glass.

CeO ₂ is a component that enhances the radiation resistance of glass. The CeO ₂ content is 0.1 to 5.0%, preferably 0.1 to 2.0%, more preferably 0.5 to 2.0%, and still more preferably 1.1 to 2.0%. is there. If the CeO ₂ content is less than 0.1%, the radiation resistance coloring property of the glass is lowered, and the glass is markedly colored by the irradiation of radiation. When the content of CeO ₂ is more than 5.0%, the coloring of the glass before radiation irradiation becomes strong. Ce ions usually coexist in the state of Ce ³⁺ and Ce ^{4+ in} glass. Ce ³⁺ has a sharp absorption band centered at a wavelength of 314 nm. Ce ⁴⁺ is centered on a wavelength of 240 nm and has a broad absorption band in the visible range. As the CeO ₂ content increases, the absolute amount of Ce ^{4+ in} the glass also increases, so that the color of the glass before radiation irradiation tends to increase.

SnO ₂ is a component that suppresses the initial coloration of the glass due to Ce ^{4+ and the} like. Sn ions usually coexist in the glass in the state of Sn ²⁺ and Sn ⁴⁺ . When SnO ₂ coexists with CeO ₂ , Sn ions are oxidized by the oxidizing power of Ce ions, and the ratio of Sn ⁴⁺ increases. At the same time, Ce ions themselves are reduced, and the ratio of Ce ⁴⁺ decreases. Thus, when the proportion of Ce ⁴⁺ is reduced, the initial coloration of the glass is reduced. The content of SnO ₂ is 0.1 to 2.0%, preferably 0.1 to 1.5%, more preferably 0.1 to 1.0%. When the content of SnO ₂ is more than 2.0%, the coloring of the glass with Sn ions is strengthened, and the glass is easily blackened during the heat processing. When the content of SnO ₂ is less than 0.1%, the ratio of Ce ^{4+ in} the glass is difficult to decrease, and thus it is difficult to suppress initial coloring.

In addition to the above components, other components may be added to the borosilicate glass of the present invention within a range where the coloration of the glass before and after radiation irradiation does not increase. For example, MgO, SrO, ZnO, ZrO ₂ , P ₂ O ₅ , Cr ₂ O ₃ , SO ₂ , PbO, La ₂ O ₃ , WO ₃ , Co ₃ O ₄ for improving the viscosity and clarity of the glass. Nb ₂ O ₅ , Y ₂ O ₃ or the like may be added. The total amount of these components added is preferably 5% or less.

Fe ₂ O ₃ is a component mixed from the glass raw material and the glass manufacturing process. Fe ₂ O ₃ has a function of protecting the medicine filled in the container from ultraviolet rays by combining with TiO ₂ . However, if the content of Fe ₂ O ₃ is too large, there is a fear that the glass is colored. Therefore, the content of Fe ₂ O ₃ is preferably 0.001% to 0.5%, more preferably 0.001% to 0.2%, 0.001% to 0.1%, 0.001% to 0.05%.

TiO ₂ is a component that blocks ultraviolet rays and prevents deterioration of the filled medicine. Moreover, it is a component which reduces the high temperature viscosity of glass and improves a moldability. However, when the content of TiO ₂ is too large, or glass is colored, easily devitrified. Therefore, the content of TiO ₂ is preferably 0 to 2%, more preferably 0 to 1%, 0 to 0.5%, 0 to 0.3%, 0 to 0.1%, 0.001. ~ 0.05%.

Cl ₂ is a component that improves clarity during glass production, and the content of Cl ₂ is preferably 0 to 1%. When the content of Cl ₂ exceeds 1%, Cl ₂ evaporated during the production of glass may react with moisture and corrode the metal in the production facility. The Cl ₂ content is preferably 0 to 0.5%, more preferably 0 to 0.3%, and still more preferably 0.01 to 0.3%.

Sb ₂ O ₃ is a component that improves the clarity of the molten glass. Meanwhile, Sb ₂ O ₃ are the high environmental load component, the content thereof is preferably less than 1%.

ZrO ₂ is a component that improves the chemical resistance of glass, particularly the acid resistance, and lowers the high-temperature viscosity to improve the meltability. The content of ZrO ₂ is preferably 0 to 1%, more preferably 0 to 0.5%, and 0.01 to 0.3%. If it exceeds 5%, the devitrification temperature rises and devitrified foreign matter tends to precipitate.

Furthermore, borosilicate glass of the present _{invention H 2, CO 2, CO,} H 2 O, He, Ne, Ar, minor components such as _{N 2} may contain up to 0.1%. Moreover, you may add noble metal elements, such as Pt and Rh, to 500 ppm in glass.

  In the borosilicate glass of the present invention, the absorbance of light having a wavelength of 500 nm at a thickness of 5 mm before radiation irradiation is 0.15 or less, preferably 0.12 or less, more preferably 0.10 or less. If the absorbance of light having a wavelength of 500 nm at a thickness of 5 mm before radiation irradiation is higher than 0.20, the glass will remain strongly colored even after radiation irradiation, and inspection after radiation sterilization becomes difficult.

  In the borosilicate glass of the present invention, the absorbance of light having a wavelength of 500 nm at a thickness of 5 mm after irradiation with radiation at an absorbed dose of 25 kGy is 0.30 or less, preferably 0.28 or less, more preferably 0.25 or less. . If the absorbance of light having a wavelength of 500 nm at a thickness of 5 mm after irradiation with radiation at an absorbed dose of 25 kGy is higher than 0.30, the glass after irradiation is strongly colored, and inspection after radiation sterilization becomes difficult.

  The borosilicate glass of the present invention is preferably used for medical containers such as pharmaceutical containers and vacuum blood collection tubes that are sterilized by radiation such as γ rays and electron beams. These medical containers can be manufactured, for example, by cutting and processing the borosilicate glass of the present invention formed into a tubular shape. These medical containers are more preferably subjected to sterilization treatment with γ rays or electron beams. Since γ rays have high energy, sterilization ability is high, and a large amount of containers can be sterilized in a short time. In addition, the electron beam has a low environmental load and is easy to manage the sterilization apparatus and process.

  In addition, the said use is an example and the use of the borosilicate glass of this invention is not restricted to these, It is applicable to arbitrary uses and arbitrary shapes. Moreover, the radiation used for the sterilization treatment of these medical containers is not limited to γ rays and electron beams, and radiation of any kind and intensity may be used.

Hereinafter, based on an Example, this invention is demonstrated in detail.

  Tables 1 to 3 show examples (sample Nos. 1 to 12) and comparative examples (samples No. 13 and 14) of the present invention.

  Each sample was prepared as follows. First, glass raw materials were weighed and mixed so as to have the glass composition in the table to prepare a glass batch. Next, this glass batch was melted in a platinum crucible at 1650 ° C. for 5 hours and then poured out to prepare a glass ingot. Next, the glass ingot was cut into a size of 25 mm × 30 mm and polished to obtain plate-like glass samples having a thickness of 5.0 mm and 1.5 mm. And the following characteristics were evaluated before and after radiation irradiation of each obtained sample.

  The absorbance at a wavelength of 500 nm was calculated based on the spectral transmittance measured by measuring the spectral transmittance at a wavelength of 500 nm. The spectral transmittance at a wavelength of 500 nm was read at a wavelength of 500 nm using a UV-3100PC spectrophotometer manufactured by SHIMADZU. The smaller the absorbance, the more transparent the glass.

  As radiation, γ rays and electron beams were irradiated at an absorbed dose of 25 kGy. The γ-ray irradiation was performed using a cobalt 60 radiation source. Electron beam irradiation was performed using an electron accelerator with an output of 5 MeV. The absorbed dose was measured with a glass dosimeter.

  As is apparent from Tables 1 to 3, sample No. Nos. 1 to 12 had an absorbance value of 0.15 or less at a thickness of 5.0 mm before irradiation with a wavelength of 500 nm. Moreover, the light absorbency of the light of wavelength 500nm in thickness 5.0mm after irradiating only radiation dose 25kGy was 0.30 or less.

On the other hand, sample No. Since Nos. 13 and 14 did not contain SnO ₂ , the absorbance value at a thickness of 5.0 mm and a wavelength of 500 nm before irradiation exceeded 0.15. Further, the absorbance of light having a wavelength of 500 nm at a thickness of 5.0 mm after irradiation with an absorbed dose of 25 kGy exceeded 0.30. That is, sample no. 13 and 14 were inferior in transparency before and after radiation irradiation as compared with the examples of the present invention.

  The borosilicate glass of the present invention is useful as a material for medical containers.

Claims (8)

By mass% terms of oxide as a glass _{composition, SiO 2 65~78%, B 2} O 3 8~18%, Li 2 O + Na 2 O + K 2 O 1~18%, CeO 2 0.1~5.0% A borosilicate glass containing 0.1 to 2.0% of SnO ₂ . By mass% terms of oxide as a glass _{composition, SiO 2 65~75%, B 2} O 3 8~18%, Li 2 O + Na 2 O + K 2 O 1~10%, CeO 2 0.1~5.0% SnO ₂ 0.1-2.0%, Al ₂ O ₃ 0-10%, CaO 0-7%, BaO 0-5%, Li ₂ O 0-5%, Na ₂ O 0-10%, K The borosilicate glass according to claim 1, containing 0 to 5% of ₂ O. The borosilicate glass according to claim 1, wherein the content of CeO ₂ is 1.1 to 5.0%.   The borosilicate glass according to any one of claims 1 to 3, wherein the absorbance before irradiation is 0.15 or less.   The borosilicate glass according to any one of claims 1 to 4, wherein the absorbance after irradiation with radiation at an absorbed dose of 25 kGy is 0.30 or less.   The borosilicate glass according to claim 1, wherein the borosilicate glass is used for a medical container that is sterilized by radiation.   The borosilicate glass according to any one of claims 1 to 5, wherein the borosilicate glass is used for a vacuum blood collection tube sterilized by gamma rays or electron beams.   The borosilicate glass according to any one of claims 1 to 5, wherein the borosilicate glass is used for a pharmaceutical container sterilized by gamma rays or electron beams.