JP2007167816A

JP2007167816A - Method and apparatus for producing ultrapure water

Info

Publication number: JP2007167816A
Application number: JP2005372619A
Authority: JP
Inventors: Mitsuhiro Nonogaki; 光裕野々垣; Atsuhiro Fujii; 淳弘藤井
Original assignee: Renesas Technology Corp
Current assignee: Renesas Technology Corp
Priority date: 2005-12-26
Filing date: 2005-12-26
Publication date: 2007-07-05

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method and an apparatus for producing ultrapure water which enable high-purity ultrapure water to be stably and efficiently produced by controlling the concentration of a Na<SP>+</SP>ion in ultrapure water to 0.1 ppt or below and decreasing the concentration of TOC (total organic carbon) therein. <P>SOLUTION: The method for producing ultrapure water comprises a step of making primary pure water 10 pass through an ion exchange unit 3 having a mixed bed of a strong acid cation exchange resin with a strong basic anion exchange resin to produce ultrapure water. The exchange capacity of the strong acid cation exchange resin is 1.5-2.5 meq/mL and that of the strong basic anion exchange resin is 0.5-1.5 meq/mL. The ratio of the volume of the cation exchange resin to the total volume of the strong acid cation exchange resin and the strong basic anion exchange resin is ≥40% and <70%. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

本発明は、半導体や液晶表示装置など電子デバイス産業分野に用いられる洗浄用の超純水の製造方法および製造装置に関し、詳しくは、一次純水を強酸性カチオン交換樹脂と強塩基性アニオン交換樹脂とで構成される混床を備えるイオン交換装置に通すことにより超純水を形成する超純水の製造方法に関する。 TECHNICAL FIELD The present invention relates to a method and an apparatus for producing ultrapure water for cleaning used in the field of electronic devices such as semiconductors and liquid crystal display devices, and more specifically, primary pure water is made from a strongly acidic cation exchange resin and a strongly basic anion exchange resin. It is related with the manufacturing method of the ultrapure water which forms ultrapure water by letting it pass through the ion exchange apparatus provided with the mixed bed comprised by these.

従来の市水、地下水、工水等の原水から超純水を製造する超純水製造装置は、一般的に、原水から一次純水を製造する一次純水製造装置と、一次純水からさらに純度の高い二次純水（超純水ともいう、以下同じ）を製造する二次純水製造装置とから構成される。このうち、一次純水製造装置は、一般的に、凝集、浮上、濾過装置などから構成される前処理装置と、２床３塔式イオン交換塔、電気再生式脱塩装置、再生型混床式イオン交換装置などの脱塩処理装置と、真空脱気装置や膜脱気装置、窒素曝気装置など溶存酸素を除去する目的の脱気装置と、逆浸透膜分離装置と、混床式の再生型イオン交換装置とで構成される。また、二次純水製造装置は、一般的に、低圧紫外線酸化装置と、混床式イオン交換装置と、限外濾過膜分離装置とで構成される。ここで、一次純水の純度は、処理される原水の水質、装置の仕様にも影響されるが、一般的に、Ｎａ⁺イオン濃度が１０〜１００ｐｐｔ程度、ＴＯＣ（全有機炭素、以下同じ）濃度が数ｐｐｂ程度である。 Conventionally, ultrapure water production equipment that produces ultrapure water from raw water such as city water, groundwater, and industrial water is generally composed of primary pure water production equipment that produces primary pure water from raw water, and primary pure water. It comprises a secondary pure water production device for producing high purity secondary pure water (also referred to as ultrapure water, hereinafter the same). Of these, the primary pure water production apparatus is generally composed of a pretreatment apparatus composed of agglomeration, flotation, filtration apparatus, etc., a two-bed / three-column ion exchange tower, an electric regenerative demineralizer, a regenerative mixed bed Desalination equipment such as ion exchange equipment, degassing equipment for the purpose of removing dissolved oxygen, such as vacuum degassing equipment, membrane degassing equipment, and nitrogen aeration equipment, reverse osmosis membrane separation equipment, and mixed bed regeneration Type ion exchanger. The secondary pure water production apparatus is generally composed of a low-pressure ultraviolet oxidizer, a mixed bed ion exchanger, and an ultrafiltration membrane separator. Here, the purity of the primary pure water is influenced by the quality of the raw water to be treated and the specifications of the apparatus, but in general, the Na ⁺ ion concentration is about 10 to 100 ppt, TOC (total organic carbon, the same applies hereinafter). The concentration is about several ppb.

このうち、二次純水製造装置における混床式イオン交換装置としては、非再生混床式のものが使用されている。この装置は、ボンベ型またはタンク型の容器に、カチオン交換樹脂とアニオン交換樹脂とが混合されて充填されたものであり、一定期間使用された後、容器ごと交換して別途再生されて再使用される場合と、固定のタンク型容器内の樹脂のみを詰め替えて使用される場合がある。 Among these, the non-regenerative mixed bed type is used as the mixed bed type ion exchange apparatus in the secondary pure water production apparatus. This device is a cylinder-type or tank-type container filled with a mixture of cation exchange resin and anion exchange resin. After being used for a certain period of time, the container is replaced and reused separately. In some cases, only the resin in the fixed tank-type container is refilled and used.

従来の、半導体などで問題となる純水からのＮａ⁺イオン汚染に対する対策として、二次純水製造装置のイオン交換装置に着目した事例がある。強酸性カチオン交換樹脂と強塩基性アニオン交換樹脂の混床に純水を通過させた後、強酸性カチオン交換樹脂の単床に純水を通過させることにより、得られる超純水のＮａ⁺イオン濃度を１０ｐｐｔ以下に抑制している（たとえば、特許文献１を参照）。 As a conventional countermeasure against Na ⁺ ion contamination from pure water, which is a problem in semiconductors, there is an example focusing on an ion exchange device of a secondary pure water production apparatus. After passing pure water through a mixed bed of a strongly acidic cation exchange resin and a strongly basic anion exchange resin, and passing pure water through a single bed of a strong acid cation exchange resin, the resulting Na ⁺ ion of ultrapure water is obtained. The concentration is suppressed to 10 ppt or less (see, for example, Patent Document 1).

また、アニオン交換樹脂については、アニオン交換樹脂の一部の溶出による純水のＴＯＣ濃度の増加を抑制することを目的として、アニオン交換樹脂の対アニオンを制御した事例がある（たとえば、特許文献２を参照）。 As for the anion exchange resin, there is an example in which the counter anion of the anion exchange resin is controlled for the purpose of suppressing an increase in the TOC concentration of pure water due to elution of a part of the anion exchange resin (for example, Patent Document 2). See).

しかし、特許文献１のイオン交換装置では、超純水中のＮａ⁺イオン濃度を１０ｐｐｔ以下にできるものの、昨今の半導体デバイスの洗浄水における不純物濃度の要求レベルは１ｐｐｔ以下と厳しくなっており、かかる要求レベルに対して十分に満足できる純度が得られないという問題がある。また、特許文献２のアニオン交換樹脂に関しては、単独で使用される場合の性能向上であり、非再生混床式イオン交換装置としての最適解とはなり得ない問題があった。
特開平６−８６９７６号公報特開２００３−２４８００号公報 However, in the ion exchange apparatus of Patent Document 1, although the Na ⁺ ion concentration in ultrapure water can be reduced to 10 ppt or less, the required level of impurity concentration in the washing water for semiconductor devices in recent years has become strict as 1 ppt or less. There is a problem that a sufficiently satisfactory purity cannot be obtained for the required level. Further, the anion exchange resin of Patent Document 2 is a performance improvement when used alone, and there is a problem that it cannot be an optimal solution as a non-regenerative mixed bed ion exchange apparatus.
JP-A-6-86976 Japanese Patent Laid-Open No. 2003-24800

本発明は、上記のような問題点を解決するためになされたものであり、二次純水製造工程におけるイオン交換装置から流出する超純水中のＮａ⁺イオン濃度を０．１ｐｐｔ以下に抑制するとともに、ＴＯＣ濃度を低減して、高純度の超純水を安定に効率よく製造する方法、およびその装置を提供することを目的としている。 The present invention has been made to solve the above-described problems, and suppresses the Na ⁺ ion concentration in ultrapure water flowing out from the ion exchange device in the secondary pure water production process to 0.1 ppt or less. In addition, an object of the present invention is to provide a method and an apparatus for producing high-purity ultrapure water stably and efficiently by reducing the TOC concentration.

本発明は、一次純水を強酸性カチオン交換樹脂と強塩基性アニオン交換樹脂とで構成される混床を備えるイオン交換装置に通すことにより超純水を形成する超純水の製造方法であって、強酸性カチオン交換樹脂の交換容量が１．５〜２．５ｍｅｑ／ｍＬ（ミリエキバレント／ミリリットル、以下同じ）、強塩基性アニオン交換樹脂の交換容量が０．５〜１．５ｍｅｑ／ｍＬ、強酸性カチオン交換樹脂および強塩基性アニオン交換樹脂の総体積に対するカチオン交換樹脂の体積の比率が４０％以上７０％未満であることを特徴とする超純水の製造方法である。 The present invention is a method for producing ultrapure water that forms ultrapure water by passing primary pure water through an ion exchange device having a mixed bed composed of a strongly acidic cation exchange resin and a strongly basic anion exchange resin. Thus, the exchange capacity of the strongly acidic cation exchange resin is 1.5 to 2.5 meq / mL (millivalent / milliliter, the same applies hereinafter), and the exchange capacity of the strongly basic anion exchange resin is 0.5 to 1.5 meq / mL. And a ratio of the volume of the cation exchange resin to the total volume of the strongly acidic cation exchange resin and the strongly basic anion exchange resin is 40% or more and less than 70%.

本発明にかかる超純水の製造方法においては、一次純水を低圧紫外線酸化装置に通し、上記イオン交換装置に通し、さらに限外濾過膜分離装置に通すことにより超純水を形成することができる。 In the method for producing ultrapure water according to the present invention, ultrapure water can be formed by passing primary pure water through a low-pressure ultraviolet oxidation device, through the ion exchange device, and further through an ultrafiltration membrane separation device. it can.

また、本発明は、一次純水から超純水を形成するための超純水の製造装置であって、強酸性カチオン交換樹脂と強塩基性アニオン交換樹脂とで構成される混床を備えるイオン交換装置を含み、強酸性カチオン交換樹脂の交換容量が１．５〜２．５ｍｅｑ／ｍＬ、強塩基性アニオン交換樹脂の交換容量が０．５〜１．５ｍｅｑ／ｍＬ、強酸性カチオン交換樹脂および強塩基性アニオン交換樹脂の総体積に対するカチオン交換樹脂の体積の比率が、４０％以上７０％未満であることを特徴とする超純水の製造装置である。 The present invention also relates to an apparatus for producing ultrapure water for forming ultrapure water from primary pure water, comprising a mixed bed composed of a strongly acidic cation exchange resin and a strongly basic anion exchange resin. An exchange device, the exchange capacity of the strongly acidic cation exchange resin is 1.5 to 2.5 meq / mL, the exchange capacity of the strongly basic anion exchange resin is 0.5 to 1.5 meq / mL, and the strongly acidic cation exchange resin and The apparatus for producing ultrapure water, wherein the ratio of the volume of the cation exchange resin to the total volume of the strongly basic anion exchange resin is 40% or more and less than 70%.

本発明にかかる超純水の製造装置においては、イオン交換装置に加えて、イオン交換装置の上流側に低圧紫外線酸化装置と、イオン交換装置の下流側に限外濾過膜分離装置とを含むことができる。 The ultrapure water production apparatus according to the present invention includes, in addition to the ion exchange apparatus, a low-pressure ultraviolet oxidation apparatus upstream of the ion exchange apparatus and an ultrafiltration membrane separation apparatus downstream of the ion exchange apparatus. Can do.

本発明によれば、交換容量が１．５〜２．５ｍｅｑ／ｍＬの強酸性カチオン交換樹脂と、交換容量が０．５〜１．５ｍｅｑ／ｍＬの強塩基性アニオン交換樹脂とから構成され、強酸性カチオン交換樹脂および強塩基性アニオン交換樹脂の総体積に対する強酸性カチオン交換樹脂の体積の比率が４０％以上７０％未満である混床に、一次純水を通すことにより、Ｎａ⁺イオン濃度が０．１ｐｐｔ以下でＴＯＣ濃度が低減した高純度の超純水が得られる。かかる超純水は、半導体や液晶表示装置など電子デバイスの洗浄用の純水として好ましく用いられる。 According to the present invention, it is composed of a strongly acidic cation exchange resin having an exchange capacity of 1.5 to 2.5 meq / mL and a strongly basic anion exchange resin having an exchange capacity of 0.5 to 1.5 meq / mL, By passing primary pure water through a mixed bed in which the ratio of the volume of the strongly acidic cation exchange resin to the total volume of the strongly acidic cation exchange resin and the strongly basic anion exchange resin is 40% or more and less than 70%, Na ⁺ ion concentration Is 0.1 ppt or less, and high purity ultrapure water with a reduced TOC concentration is obtained. Such ultrapure water is preferably used as pure water for cleaning electronic devices such as semiconductors and liquid crystal display devices.

（実施形態１）
本発明にかかる超純水の製造装置の一実施形態は、図１を参照して、強酸性カチオン交換樹脂と強塩基性アニオン交換樹脂とで構成される混床を備えるイオン交換装置３と、このイオン交換装置の上流側に低圧紫外線酸化装置２と、イオン交換装置の下流側に限外濾過膜分離装置４とが含まれる。これらの装置が、配管１１，１２，１３，１４，１５，１６，１７で連結されている。また、各装置に純水を循環させるための送水ポンプ９が配管１２に設けられている。 (Embodiment 1)
One embodiment of the apparatus for producing ultrapure water according to the present invention is described with reference to FIG. 1, an ion exchange device 3 comprising a mixed bed composed of a strongly acidic cation exchange resin and a strongly basic anion exchange resin, A low-pressure ultraviolet oxidizer 2 is included upstream of the ion exchanger, and an ultrafiltration membrane separator 4 is included downstream of the ion exchanger. These devices are connected by pipes 11, 12, 13, 14, 15, 16, and 17. Further, a water supply pump 9 for circulating pure water through each device is provided in the pipe 12.

ここで、上記イオン交換装置は、強酸性カチオン交換樹脂と強塩基性アニオン交換樹脂とで構成される混床を含み、強酸性カチオン交換樹脂の交換容量が１．５〜２．５ｍｅｑ／ｍＬ、強塩基性アニオン交換樹脂の交換容量が０．５〜１．５ｍｅｑ／ｍＬ、強酸性カチオン交換樹脂および強塩基***換樹脂の総体積に対する強酸性カチオン交換樹脂の体積の比率が４０％以上７０％未満であることを特徴とする。１次純水を上記イオン交換装置に通すことにより得られる２次純水である超純水のＮａ⁺イオン濃度を０．１ｐｐｔ以下に抑制し、ＴＯＣ濃度を低減することができる。 Here, the ion exchange device includes a mixed bed composed of a strongly acidic cation exchange resin and a strongly basic anion exchange resin, and the exchange capacity of the strongly acidic cation exchange resin is 1.5 to 2.5 meq / mL, The exchange capacity of the strongly basic anion exchange resin is 0.5 to 1.5 meq / mL, and the ratio of the volume of the strongly acidic cation exchange resin to the total volume of the strongly acidic cation exchange resin and the strongly basic exchange resin is 40% to 70%. It is characterized by being less than. The Na ⁺ ion concentration of ultrapure water, which is secondary pure water obtained by passing primary pure water through the ion exchanger, can be suppressed to 0.1 ppt or less, and the TOC concentration can be reduced.

上記イオン交換装置には、強酸性カチオン交換樹脂と強塩基性アニオン交換樹脂とで構成される混床が含まれ、強酸性カチオン交換樹脂および強塩基***換樹脂の総体積に対する強酸性カチオン交換樹脂の体積の比率（以下、強酸性カチオン樹脂の体積比率という）は４０％以上７０％未満である。 The ion exchange apparatus includes a mixed bed composed of a strongly acidic cation exchange resin and a strongly basic anion exchange resin, and a strongly acidic cation exchange resin with respect to the total volume of the strongly acidic cation exchange resin and the strongly basic exchange resin. The volume ratio (hereinafter referred to as the volume ratio of the strongly acidic cation resin) is 40% or more and less than 70%.

強酸性カチオン交換樹脂の体積比率が４０％より小さいと、超純水中のＮａ⁺イオン濃度を０．１ｐｐｔ以下にするのが困難になる。また、強塩基性アニオン交換樹脂の塩基性が強くなり、樹脂の加水分解が生じ、強塩基性アニオン交換樹脂の官能基として使われる有機系カチオン成分の溶出が大きくなる。この有機系カチオン成分の溶出を抑制するべき強酸性カチオン交換樹脂のカチオン交換能力が、体積比率が小さいことから小さくなるため、この有機系カチオン成分が流出し、超純水中のＴＯＣ濃度の低減が困難となる。 If the volume ratio of the strongly acidic cation exchange resin is smaller than 40%, it becomes difficult to make the Na ⁺ ion concentration in the ultrapure water 0.1 ppt or less. In addition, the basicity of the strongly basic anion exchange resin becomes stronger, the resin is hydrolyzed, and the elution of the organic cation component used as the functional group of the strongly basic anion exchange resin is increased. Since the cation exchange capacity of the strongly acidic cation exchange resin to suppress elution of the organic cation component is small because the volume ratio is small, the organic cation component flows out, and the TOC concentration in ultrapure water is reduced. It becomes difficult.

強酸性カチオン交換樹脂の体積比率が７０％以上となると、強酸性カチオン交換樹脂の官能基である有機系アニオン成分の溶出が大きくなる。この有機系アニオン成分の溶出を抑制するべき強塩基性アニオン交換樹脂のアニオン交換能力が、体積比率が小さいことから小さくなるため、この有機アニオン成分が流出し、超純水中のＴＯＣ濃度の低減が困難となる。 When the volume ratio of the strongly acidic cation exchange resin is 70% or more, elution of the organic anion component that is a functional group of the strongly acidic cation exchange resin becomes large. Since the anion exchange capacity of the strongly basic anion exchange resin that should suppress the elution of the organic anion component is small because the volume ratio is small, the organic anion component flows out and the TOC concentration in the ultrapure water is reduced. It becomes difficult.

また、Ｎａ⁺イオンの捕獲能力は、（１）式
Ｒ−ＳＯ₃Ｈ＋ＮａＯＨ → Ｒ−ＳＯ₃Ｎａ＋Ｈ₂Ｏ・・・（１）
に示される不可逆反応よりも、純水中に微量に存在するＣｌ^-イオンの影響により（２）式
Ｒ−ＳＯ₃Ｈ＋ＮａＣｌ ⇔ Ｒ−ＳＯ₃Ｎａ＋ＨＣｌ・・・（２）
に示される可逆反応に支配される。このため、純水の流通速度によっては、強酸性カチオン交換樹脂に捕獲されたＮａ⁺イオンが再度純水中に流出する傾向となる。 Moreover, the capture ability of Na ⁺ ions is as follows: (1) Formula R—SO ₃ H + NaOH → R—SO ₃ Na + H ₂ O (1)
Than the irreversible reaction shown in the formula (2) due to the influence of Cl ⁻ ions present in a minute amount in pure water (2) Formula R—SO ₃ H + NaCl ⇔ R—SO ₃ Na + HCl (2)
It is governed by the reversible reaction shown in For this reason, depending on the flow rate of pure water, Na ⁺ ions captured by the strongly acidic cation exchange resin tend to flow out into the pure water again.

上記の観点から、強酸性カチオン交換樹脂の体積比率は、４５％以上５０％以下であることが好ましい。 From the above viewpoint, the volume ratio of the strongly acidic cation exchange resin is preferably 45% or more and 50% or less.

強酸性カチオン交換樹脂は、交換容量が１．５〜２．５ｍｅｑ／ｍＬのものであれば、特に制限はないが、樹脂の加水分解が少なく有機系アニオン成分の純水への溶出が少ない観点から、官能基としてスルホン酸を有するスチレン系樹脂が好ましく用いられる。強酸性カチオン樹脂の交換容量が１．５ｍｅｑ／ｍＬより小さいとカチオン成分の捕獲能力が低下し純水中のＮａ⁺イオン濃度の低減が困難となる。強酸性カチオン樹脂の交換容量が１．５ｍｅｑ／ｍＬより大きいと樹脂粒子間の凝集を起こしやすくなり結果的に純水中のＮａ⁺イオン濃度の低減が困難となる。 The strong acid cation exchange resin is not particularly limited as long as it has an exchange capacity of 1.5 to 2.5 meq / mL, but the viewpoint of less elution of the organic anion component into pure water with less hydrolysis of the resin. Therefore, a styrene resin having sulfonic acid as a functional group is preferably used. If the exchange capacity of the strongly acidic cation resin is less than 1.5 meq / mL, the ability to capture the cation component is lowered, making it difficult to reduce the Na ⁺ ion concentration in pure water. If the exchange capacity of the strongly acidic cation resin is larger than 1.5 meq / mL, aggregation between the resin particles tends to occur, and as a result, it is difficult to reduce the Na ⁺ ion concentration in the pure water.

また、強酸性カチオン交換樹脂は、Ｒ−Ｈ形９９．９％以上の転換率を有する有効径が０．４〜０．６ｍｍ、樹脂粒子の均一粒径が１．５以下のものが好ましい。ここで、強酸性カチオン交換樹脂の転換率ｒ_cは、（３）式
ｒ_c＝100×(R-SO₃Hの官能基数)／((R-SO₃Naの官能基数)＋(R-SO₃Hの官能基総数)）
・・・（３）
で定義される。また、イオン交換樹脂（カチオン交換樹脂およびアニオン交換樹脂の総称をいう、以下同じ）の粒子の大きさをふるいによって分級して、粒子径毎の分布の状態を正規分布とみなして対数確率グラフに直線としてプロットし、ふるい残留百分率累計値が９０％および４０％に対応するそれぞれのふるいの目開き（単位：ｍｍ）を求める。このとき、ふるい残留百分率累計値が９０％に対応するふるいの目開きを有効径といい、有効径に対するふるい残留百分率累計値が９０％に対応するふるいの目開きの比を均一係数という。 Further, the strong acid cation exchange resin preferably has an effective diameter of 0.4 to 0.6 mm having a conversion rate of 99.9% or more of RH type and a uniform particle diameter of the resin particles of 1.5 or less. Here, the conversion rate r _c of the strongly acidic cation exchange resin is expressed by the following formula (3): r _c = 100 × (number of functional groups of R—SO ₃ H) / ((number of functional groups of R—SO ₃ Na) + (R− Total number of functional groups of SO ₃ H))
... (3)
Defined by In addition, the particle size of ion exchange resin (generic name for cation exchange resin and anion exchange resin, the same shall apply hereinafter) is classified by sieving, and the distribution state for each particle diameter is regarded as a normal distribution and is expressed in a logarithmic probability graph. Plot as a straight line, and determine the sieve opening (unit: mm) of each sieve corresponding to 90% and 40% cumulative residual percentage of sieves. At this time, the opening of the sieve corresponding to the sieve residual percentage cumulative value of 90% is referred to as an effective diameter, and the ratio of the sieve opening corresponding to the sieve residual cumulative value of 90% relative to the effective diameter is referred to as a uniformity coefficient.

強塩基性アニオン交換樹脂は、交換容量が０．５〜１．５ｍｅｑ／ｍＬのものであれば、特に制限はないが、樹脂の加水分解が少なく有機系カチオン成分の純水への溶出が少ない観点から、官能基として４級アンモニウム塩を有するスチレン系樹脂が好ましく用いられる。強塩基性アニオン交換樹脂の交換容量が０．５ｍｅｑ／ｍＬより小さいと、アニオン成分の捕獲能力が低下する。また、強塩基性アニオン交換樹脂の交換容量が１．５ｍｅｑ／ｍＬより大きいと、また、強塩基性アニオン交換樹脂の塩基性が強くなり、樹脂の加水分解が生じる。 The strong base anion exchange resin is not particularly limited as long as it has an exchange capacity of 0.5 to 1.5 meq / mL, but there is little hydrolysis of the resin and elution of organic cation components into pure water is small. From the viewpoint, a styrene resin having a quaternary ammonium salt as a functional group is preferably used. When the exchange capacity of the strongly basic anion exchange resin is smaller than 0.5 meq / mL, the anion component capturing ability is lowered. On the other hand, if the exchange capacity of the strongly basic anion exchange resin is larger than 1.5 meq / mL, the basicity of the strongly basic anion exchange resin becomes strong and hydrolysis of the resin occurs.

また、強塩基性アニオン交換樹脂は、Ｒ−ＯＨ型９０％以上の転換率を有する有効径が０．４〜０．６ｍｍ、樹脂粒子の均一係数が１．５以下のものが好ましい。ここで、強塩基性アニオン交換樹脂の転換率ｒ_aは、（４）式
ｒ_a＝100×(R-OHの官能基数)／((R-Clの官能基数)＋(R-OHの官能基総数))
・・・（４）
で定義される。 The strong base anion exchange resin preferably has an R-OH type conversion ratio of 90% or more having an effective diameter of 0.4 to 0.6 mm and a resin particle uniformity coefficient of 1.5 or less. Here, conversion rate r _a strong base anion exchange resin, (4) (number of functional groups R-OH) r _a = 100 × / ((number of functional groups R-Cl) + (bifunctional R-OH Total number)))
... (4)
Defined by

本発明の混床式イオン交換装置は、ＳＶ（空間速度、以下同じ）が３０ｈｒ^-1以上と幅広い条件で使用可能となるが、ＳＶが５０〜１００ｈｒ^-1で用いるのが好ましい。ここで、ＳＶ（空間速度）とは水を処理する速度の指標で、１時間に処理できる水の体積を濾過材であるイオン交換樹脂の体積（カチオン交換樹脂およびアニオン交換樹脂の合計体積）で割った値をいう。またイオン交換装置の容器形状は、特に限定されないが、少なくとも６００ｍｍ以上の充填時の樹脂層高を持つ容器が好ましい。また、混床は、再生の際のＮａ⁺イオンの流出を防止するため、非再生混床が好ましく用いられる。 The mixed bed type ion exchange apparatus of the present invention can be used under a wide range of SV (space velocity, the same shall apply hereinafter) of 30 hr ⁻¹ or more, but is preferably used at SV of 50 to 100 hr ⁻¹ . Here, SV (space velocity) is an index of the speed at which water is treated, and the volume of water that can be treated in one hour is the volume of ion exchange resin that is a filtering material (total volume of cation exchange resin and anion exchange resin). The value divided by. The container shape of the ion exchange device is not particularly limited, but a container having a resin layer height at the time of filling of at least 600 mm or more is preferable. Further, as the mixed bed, a non-regenerated mixed bed is preferably used in order to prevent Na ⁺ ions from flowing out during the regeneration.

なお、本発明にかかる超純水の製造装置は、図１に示す構成のみに限定されるものではない。たとえば、送水ポンプの設置位置は、低圧紫外線酸化装置２の後（配管１３）、非再生混床式イオン交換装置３の後（配管１４）、または限外濾過膜分離装置４の後（配管１６または１７）であってもよい。また、循環による温度上昇などを抑制する目的で適時、熱交換装置を貯槽１の出口側に設けてもよい。 Note that the apparatus for producing ultrapure water according to the present invention is not limited to the configuration shown in FIG. For example, the water pump is installed after the low-pressure ultraviolet oxidizer 2 (pipe 13), after the non-regenerative mixed bed ion exchanger 3 (pipe 14), or after the ultrafiltration membrane separator 4 (pipe 16). Or it may be 17). In addition, a heat exchange device may be provided on the outlet side of the storage tank 1 at an appropriate time for the purpose of suppressing temperature rise due to circulation.

（実施形態２）
本発明にかかる超純水の製造方法の一実施形態は、図１を参照して、一次純水１０は、配管１１を経由して貯水槽１に貯えられ、この貯水槽１から配管１２を経由して低圧紫外線酸化装置２に送られる。低圧紫外線酸化装置２において、低圧紫外線ランプより出される１８５ｎｍの紫外線により、純水中のＴＯＣが有機酸、更にはＣＯ₂まで分解される。低圧紫外線酸化装置２から流出した純水は、配管１３を経由して非再生混床式のイオン交換装置３に送られ、純水中の有機酸や無機イオン、金属イオンなどがイオン交換により除去される。このイオン交換装置３から流出した超純水は、配管１４を経由して限外濾過膜分離装置４に送られ、限外濾過膜により分離された濃縮水は配管１５より排出される。一方、限外濾過膜を透過した超純水は、配管１６を経由してユースポイント２１，２２，２３に供給され、余剰の超純水は配管１７を経由して貯水槽１に返送される。本実施形態においては、各装置間の送水のために送水ポンプ９が用いられている。 (Embodiment 2)
In an embodiment of the method for producing ultrapure water according to the present invention, referring to FIG. 1, primary pure water 10 is stored in a water tank 1 via a pipe 11, and the pipe 12 is connected to the water tank 1. And then sent to the low-pressure ultraviolet oxidizer 2. In the low-pressure ultraviolet oxidizer 2, the TOC in pure water is decomposed to an organic acid and further to CO ₂ by 185 nm ultraviolet rays emitted from a low-pressure ultraviolet lamp. The pure water flowing out from the low-pressure ultraviolet oxidizer 2 is sent to the non-regenerative mixed bed ion exchanger 3 through the pipe 13, and organic acids, inorganic ions, metal ions, etc. in the pure water are removed by ion exchange. Is done. The ultrapure water flowing out from the ion exchange device 3 is sent to the ultrafiltration membrane separation device 4 via the pipe 14, and the concentrated water separated by the ultrafiltration membrane is discharged from the pipe 15. On the other hand, ultrapure water that has passed through the ultrafiltration membrane is supplied to the use points 21, 22, and 23 via the pipe 16, and excess ultrapure water is returned to the water tank 1 via the pipe 17. . In this embodiment, the water supply pump 9 is used for water supply between each apparatus.

本実施形態の超純水の製造方法においては、イオン交換装置が強酸性カチオン交換樹脂と強塩基性アニオン交換樹脂とで構成され、強酸性カチオン交換樹脂の交換容量が１．５〜２．５ｍｅｑ／ｍＬ、強塩基性アニオン交換樹脂の交換容量が０．５〜１．５ｍｅｑ／ｍＬ、強酸性カチオン交換樹脂および強塩基性アニオン交換樹脂の総体積に対するカチオン交換樹脂の体積の比率が、４０％以上７０％未満であることを特徴とすることにより、形成される超純水のＮａ⁺イオン濃度を０．１ｐｐｔ以下に抑制し、ＴＯＣ濃度を低減することができる。 In the method for producing ultrapure water of the present embodiment, the ion exchange device is composed of a strongly acidic cation exchange resin and a strongly basic anion exchange resin, and the exchange capacity of the strongly acidic cation exchange resin is 1.5 to 2.5 meq. / ML, the exchange capacity of the strong base anion exchange resin is 0.5 to 1.5 meq / mL, and the ratio of the volume of the cation exchange resin to the total volume of the strongly acidic cation exchange resin and the strongly basic anion exchange resin is 40%. By being characterized by being less than 70%, the Na ⁺ ion concentration of the ultrapure water to be formed can be suppressed to 0.1 ppt or less, and the TOC concentration can be reduced.

以下、実施例および比較例に基づいて、本発明にかかる超純水の製造装置および製造方法について、さらに具体的に説明する。 Hereinafter, based on an Example and a comparative example, the manufacturing apparatus and manufacturing method of the ultrapure water concerning this invention are demonstrated more concretely.

（実施例１）
図１に示す装置を用いて、一次純水の処理を行なった。ここで、非再生混床式のイオン交換装置３の容器内には、強酸性カチオン交換樹脂として三菱化学株式会社製ＳＫＴ２０と、強塩基性アニオン交換樹脂として三菱化学株式会社ＳＡＴ２０と、樹脂体積の合計が３５０Ｌ（リットル、以下同じ）で、かつ、強酸性カチオン交換樹脂の体積比率が４０％となるように、均一に混合して充填した。ここで用いたイオン交換装置の容器の大きさは、内径８００×高さ１０００ｍｍであった。水の流通条件はＳＶを１００ｈｒ^-1として、得られた超純水のＮａ⁺イオン濃度およびＴＯＣ濃度を測定したところ、それぞれ０．１０ｐｐｔおよび０．２７ｐｐｂであった。結果を表１にまとめた。ここで、Ｎａ⁺イオン濃度の測定は、イオン交換樹脂を充填して流水開始から２４ｈｒ後の超純水を採取し、ＩＣＰ−ＭＳ（誘導結合プラズマ−質量スペクトル）分析装置により求めた。また、ＴＯＣ濃度の測定は、Ｎａ⁺イオン濃度の分析と同様に採取した超純水を用い、固相抽出ＧＣ−ＭＳ（ガスクロマトグラフ−質量スペクトル）法により求めた。 Example 1
The primary pure water was treated using the apparatus shown in FIG. Here, in the container of the non-regenerative mixed bed type ion exchanger 3, SKT20 manufactured by Mitsubishi Chemical Corporation as a strongly acidic cation exchange resin, SAT20 manufactured by Mitsubishi Chemical Corporation as a strongly basic anion exchange resin, The mixture was uniformly mixed and filled so that the total was 350 L (liter, the same applies hereinafter) and the volume ratio of the strongly acidic cation exchange resin was 40%. The size of the container of the ion exchange apparatus used here was an inner diameter of 800 × height of 1000 mm. The water flow conditions were SV of 100 hr ⁻¹ , and the Na ⁺ ion concentration and TOC concentration of the obtained ultrapure water were measured and found to be 0.10 ppt and 0.27 ppb, respectively. The results are summarized in Table 1. Here, the measurement of the Na ⁺ ion concentration was obtained with an ICP-MS (inductively coupled plasma-mass spectrum) analyzer by collecting ion-exchange resin and collecting ultrapure water 24 hours after the start of flowing water. The TOC concentration was determined by solid phase extraction GC-MS (gas chromatograph-mass spectrum) method using ultrapure water collected in the same manner as the analysis of Na ⁺ ion concentration.

（実施例２）
強酸性カチオンの体積比率を４５％としたこと以外は、実施例１と同様にして、一次純水の処理を行い、超純水を得た。超純水のＮａ⁺イオン濃度は０．１０ｐｐｔ未満、ＴＯＣ濃度は０．２５ｐｐｂであった。結果を表１にまとめた。 (Example 2)
Ultra pure water was obtained by treating primary pure water in the same manner as in Example 1 except that the volume ratio of the strongly acidic cation was 45%. The Na ⁺ ion concentration of ultrapure water was less than 0.10 ppt, and the TOC concentration was 0.25 ppb. The results are summarized in Table 1.

（実施例３）
強酸性カチオンの体積比率を５０％としたこと以外は、実施例１と同様にして、一次純水の処理を行い、超純水を得た。超純水のＮａ⁺イオン濃度は０．１０ｐｐｔ未満、ＴＯＣ濃度は０．２８ｐｐｂであった。結果を表１にまとめた。 (Example 3)
Except that the volume ratio of the strongly acidic cation was 50%, primary pure water was treated in the same manner as in Example 1 to obtain ultrapure water. The Na ⁺ ion concentration of ultrapure water was less than 0.10 ppt, and the TOC concentration was 0.28 ppb. The results are summarized in Table 1.

（実施例４）
強酸性カチオンの体積比率を６４％としたこと以外は、実施例１と同様にして、一次純水の処理を行い、超純水を得た。超純水のＮａ⁺イオン濃度は０．１０ｐｐｔ未満、ＴＯＣ濃度は０．３５ｐｐｂであった。結果を表１にまとめた。 Example 4
Ultra pure water was obtained by treating primary pure water in the same manner as in Example 1 except that the volume ratio of the strongly acidic cation was 64%. The Na ⁺ ion concentration of ultrapure water was less than 0.10 ppt, and the TOC concentration was 0.35 ppb. The results are summarized in Table 1.

（比較例１）
強酸性カチオンの体積比率を２０％としたこと以外は、実施例１と同様にして、一次純水の処理を行い、超純水を得た。超純水のＮａ⁺イオン濃度は１．６８ｐｐｔ、ＴＯＣ濃度は０．４５ｐｐｂであった。結果を表１にまとめた。 (Comparative Example 1)
Except that the volume ratio of the strongly acidic cation was 20%, primary pure water was treated in the same manner as in Example 1 to obtain ultrapure water. The Na ⁺ ion concentration of ultrapure water was 1.68 ppt, and the TOC concentration was 0.45 ppb. The results are summarized in Table 1.

（比較例２）
強酸性カチオンの体積比率を３０％としたこと以外は、実施例１と同様にして、一次純水の処理を行い、超純水を得た。超純水のＮａ⁺イオン濃度は０．６８ｐｐｔ、ＴＯＣ濃度は０．３１ｐｐｂであった。結果を表１にまとめた。 (Comparative Example 2)
Except that the volume ratio of the strongly acidic cation was 30%, primary pure water was treated in the same manner as in Example 1 to obtain ultrapure water. The Na ⁺ ion concentration of ultrapure water was 0.68 ppt, and the TOC concentration was 0.31 ppb. The results are summarized in Table 1.

（比較例３）
強酸性カチオンの体積比率を７１％としたこと以外は、実施例１と同様にして、一次純水の処理を行い、超純水を得た。超純水のＮａ⁺イオン濃度は０．０３ｐｐｔ、ＴＯＣ濃度は０．６５ｐｐｂであった。結果を表１にまとめた。 (Comparative Example 3)
Except that the volume ratio of the strongly acidic cation was 71%, the primary pure water was treated in the same manner as in Example 1 to obtain ultrapure water. The Na ⁺ ion concentration of ultrapure water was 0.03 ppt, and the TOC concentration was 0.65 ppb. The results are summarized in Table 1.

（比較例４）
樹脂体積の合計を５００Ｌとし、かつ、強酸性カチオン交換樹脂の体積比率を２８％としたこと以外は、実施例１と同様にして、一次純水の処理を行い、超純水を得た。超純水のＮａ⁺イオン濃度は０．８０ｐｐｔ、ＴＯＣ濃度は０．３３ｐｐｂであった。結果を表１にまとめた。 (Comparative Example 4)
The treatment of primary pure water was carried out in the same manner as in Example 1 except that the total resin volume was 500 L and the volume ratio of the strongly acidic cation exchange resin was 28% to obtain ultrapure water. The Na ⁺ ion concentration of ultrapure water was 0.80 ppt, and the TOC concentration was 0.33 ppb. The results are summarized in Table 1.

表１において、実施例１〜４および比較例１〜３から明らかなように、強酸性カチオン交換樹脂の体積比率が４０％以上７０％未満の混床を備えるイオン交換装置により得られた超純水は、Ｎａ⁺イオン濃度が０．１０ｐｐｔ以下であり、また、ＴＯＣ濃度も低減した。また、実施例１と比較例４とを対比すると、強酸性カチオン交換樹脂の充填量が各々１４０Ｌと同体積であっても、強酸性カチオン交換樹脂の体積比率が異なれば、得られる超純水中のＮａ⁺イオン濃度が異なり、強酸性カチオン交換樹脂の体積比率が４０％以上７０％未満の範囲内にある実施例１の場合の方が、Ｎａ⁺イオン濃度が低くなっている。このことから、Ｎａ⁺イオン濃度に影響を及ぼすのは、強酸性カチオン交換樹脂の充填量ではなく、強酸性カチオン交換樹脂の体積比率であることがわかる。 In Table 1, as is clear from Examples 1 to 4 and Comparative Examples 1 to 3, the ultrapure obtained by an ion exchange apparatus having a mixed bed in which the volume ratio of the strongly acidic cation exchange resin is 40% or more and less than 70% Water had a Na ⁺ ion concentration of 0.10 ppt or less, and the TOC concentration was also reduced. Moreover, when Example 1 and Comparative Example 4 are compared, even if the filling amount of the strongly acidic cation exchange resin is the same volume as 140 L, the ultrapure water obtained if the volume ratio of the strongly acidic cation exchange resin is different. The Na ⁺ ion concentration is lower in the case of Example 1 in which the Na ⁺ ion concentration is different and the volume ratio of the strongly acidic cation exchange resin is in the range of 40% or more and less than 70%. From this, it can be seen that it is not the filling amount of the strongly acidic cation exchange resin but the volume ratio of the strongly acidic cation exchange resin that affects the Na ⁺ ion concentration.

以上のことから、混床中の樹脂総体積に対する強酸性カチオン交換樹脂の体積比率が、超純水中のＮａ⁺イオン濃度およびＴＯＣ濃度と大きな相関があることが明白である。混床中の樹脂総体積に対する強酸性カチオン交換樹脂の体積比率を４０％以上７０％未満とすることにより、Ｎａ⁺イオン濃度が０．１０ｐｐｔ以下でＴＯＣ濃度も低く、電子デバイスの洗浄に適した、高純度の超純水が得られる。 From the above, it is clear that the volume ratio of the strongly acidic cation exchange resin to the total resin volume in the mixed bed has a large correlation with the Na ⁺ ion concentration and the TOC concentration in the ultrapure water. By setting the volume ratio of the strongly acidic cation exchange resin to the total volume of the resin in the mixed bed to be 40% or more and less than 70%, the Na ⁺ ion concentration is 0.10 ppt or less and the TOC concentration is low, which is suitable for cleaning electronic devices. High-purity ultrapure water can be obtained.

今回開示された実施の形態および実施例はすべての点で例示であって制限的なものではないと考えられるべきである。本発明の範囲は、上記した説明でなくて特許請求の範囲によって示され、特許請求の範囲と均等の意味および範囲内のすべての変更が含まれることが意図される。 It should be understood that the embodiments and examples disclosed herein are illustrative and non-restrictive in every respect. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

本発明にかかる超純水の製造装置を示す模式図である。It is a schematic diagram which shows the manufacturing apparatus of the ultrapure water concerning this invention.

符号の説明Explanation of symbols

１貯水槽、２低温紫外線酸化装置、３イオン交換装置、４限外濾過膜分離装置、９送水ポンプ、１０一次純水、１１，１２，１３，１４，１５，１６，１７配管、２１，２２，２３ユースポイント。 DESCRIPTION OF SYMBOLS 1 Water storage tank, 2 Low temperature ultraviolet oxidation apparatus, 3 Ion exchange apparatus, 4 Ultrafiltration membrane separation apparatus, 9 Water supply pump, 10 Primary pure water, 11, 12, 13, 14, 15, 16, 17 Piping, 21, 22 , 23 Use points.

Claims

一次純水を強酸性カチオン交換樹脂と強塩基性アニオン交換樹脂とで構成される混床を備えるイオン交換装置に通して超純水を形成する超純水の製造方法であって、
前記強酸性カチオン交換樹脂の交換容量が１．５〜２．５ｍｅｑ／ｍＬ、
前記強塩基性アニオン交換樹脂の交換容量が０．５〜１．５ｍｅｑ／ｍＬ、
前記強酸性カチオン交換樹脂および前記強塩基性アニオン交換樹脂の総体積に対する前記カチオン交換樹脂の体積の比率が、４０％以上７０％未満であることを特徴とする超純水の製造方法。 A method for producing ultrapure water in which ultrapure water is formed by passing primary pure water through an ion exchange apparatus including a mixed bed composed of a strongly acidic cation exchange resin and a strongly basic anion exchange resin,
The exchange capacity of the strongly acidic cation exchange resin is 1.5 to 2.5 meq / mL,
The exchange capacity of the strongly basic anion exchange resin is 0.5 to 1.5 meq / mL,
A method for producing ultrapure water, wherein a ratio of a volume of the cation exchange resin to a total volume of the strong acid cation exchange resin and the strongly basic anion exchange resin is 40% or more and less than 70%.

前記一次純水を低圧紫外線酸化装置に通し、前記イオン交換装置に通し、さらに限外濾過膜分離装置に通して超純水を形成する請求項１に記載の超純水の製造方法。 The method for producing ultrapure water according to claim 1, wherein the primary pure water is passed through a low-pressure ultraviolet oxidizer, passed through the ion exchanger, and further passed through an ultrafiltration membrane separator to form ultrapure water.

一次純水から超純水を形成するための超純水の製造装置であって、
強酸性カチオン交換樹脂と強塩基性アニオン交換樹脂とで構成される混床を備えるイオン交換装置を含み、
前記強酸性カチオン交換樹脂の交換容量が１．５〜２．５ｍｅｑ／ｍＬ、
前記強塩基性アニオン交換樹脂の交換容量が０．５〜１．５ｍｅｑ／ｍＬ、
前記強酸性カチオン交換樹脂および前記強塩基性アニオン交換樹脂の総体積に対する前記カチオン交換樹脂の体積の比率が、４０％以上７０％未満であることを特徴とする超純水の製造装置。 An apparatus for producing ultrapure water for forming ultrapure water from primary pure water,
Including an ion exchange device comprising a mixed bed composed of a strongly acidic cation exchange resin and a strongly basic anion exchange resin,
The exchange capacity of the strongly acidic cation exchange resin is 1.5 to 2.5 meq / mL,
The exchange capacity of the strongly basic anion exchange resin is 0.5 to 1.5 meq / mL,
The apparatus for producing ultrapure water, wherein a ratio of a volume of the cation exchange resin to a total volume of the strong acid cation exchange resin and the strongly basic anion exchange resin is 40% or more and less than 70%.

前記イオン交換装置に加えて、前記イオン交換装置の上流側に低圧紫外線酸化装置と、前記イオン交換装置の下流側に限外濾過膜分離装置とを含む請求項３に記載の超純水の製造装置。 The ultrapure water production according to claim 3, further comprising a low-pressure ultraviolet oxidizer upstream of the ion exchanger and an ultrafiltration membrane separator downstream of the ion exchanger in addition to the ion exchanger. apparatus.