TW212208B - Hydroxamic acid containing polymers used as corrosion inhibitors - Google Patents

Abstract

Hydroxamic acid containing low molecular weight polymers have been found to be excellent corrosion inhibitors for iron and steel alloys in contact with industrial waters. When the waters contain hardness ions, such as calcium, magnesium, and mixtures thereof, the waters are preferably treated with combinations of the hydroxamic acid containing polymers and scale inhibiting/dispersing polymers, which polymers do not contain hydroxamic acid functional groups. The hydroxamic acid containing polymers, as well as the combination of hydroxamic acid and scale inhibiting/dispersing polymers may also both be formulated with other corrosion inhibitors.

Description

Λ 6 η 6 V. Description of the invention The present invention deals with the treatment of industrial water in contact with iron and pins, especially soft nets. Iron and copper alloys in contact with industrial water are extremely valuable in inhibiting their corrosion. If it fails to inhibit or prevent the corrosion of the mesh that is in contact with industrial water, the corrosion will lead to large cost problems and failure problems. In the past, water treatment in contact with ferroalloys and nets has been investigated. Inorganic ingredients such as chromate have been used to treat water, but chromate has been found to be harmful to the environment and has not been used. Water has been treated with inorganic and organic phosphates and phosphonates to inhibit corrosion. However, these materials are expensive and must be formulated with other ingredients to achieve the best results. Printed by the Ministry of Economic Affairs, the Central Bureau of Industry and Commerce A TV tv cooperative, read the notes before filling in.% I found that organic polymers, especially quite low molecular weight polymers can be used to inhibit scale corrosion, especially iron in contact with industrial water And scale corrosion of mild steel, where the polymer is mainly used as a water-proof scale agent to inhibit the formation of scale in the hardness component of water; these hardness scales include calcium nitrate, hydroxyapatite, calcium hydroxide, magnesium carbonate, magnesium phosphate, Scale of magnesium hydroxide mixed with magnesium and calcium. When the surface of iron or steel is fouled, it can accelerate the corrosion under the generated scale. Treating such water with a polymer can inhibit or prevent the formation of scale, and thus can provide some relief in terms of the increased corrosion rate in the presence of scale or under scale. In fact, it has been found that several low molecular weight polymers, whether in the presence or absence of hardness in water, are themselves corrosion inhibitors. These anti-corrosion polymers are mainly carboxylate-containing polymers of relatively low molecular weight, and often use lipophilic monomers, including methyl and ethyl acrylate, synthesized. The standard of this paper is "A Standard (CNS) T4 (210X297) *) 3 81. 7. 2U, 00U '; k (II) 2122M. Λ 6 Π 6 V. Description of the invention () Ministry of Economic Affairs It is important to note that although the polymers that can be used as anti-hardness scales and waterproof scales can also be used as anti-corrosion_, not all anti-scale polymer substances are necessarily anti-corrosion agents. In some cases, substances that are scale inhibitors can actually induce a more aggressive corrosion rate. This is especially true in the absence of hardness species such as calcium and magnesium. Polymers containing hydroxamic acid functional groups are known in the industry. For example, AJ Domb in "Poly (Hydroxamic Acid) Synthesized from Poly (Acrylamide)" See the Journal of Polymer Science: Part A: Polymer Chemistry: Volume 26, 2623-2630 (1988) Teaching: Yu Shi Temperature, by reacting polyacrylamide and hydroxylamine with ageing aqueous solution to produce polyhydroxamic acid in gel or water-soluble form. Domb's polymer contains 70% hydroxamic acid groups, less than 5% carboxyl Acid groups, and 25% unreacted acetamide groups. These polymers have a high affinity for iron ions, and have a very high rate of complexation or binding for copper ions in the pH range of 1 to 5. Usually high Materials with complex ability, when added to industrial water at high concentrations, often promote corrosion rates, such as ethylenediaminetetraacetic acid (EDTA), which has been verified to promote the corrosion rate of iron and soft dysprosium in contact with water containing EDTA Accelerate. Domb's article emphasizes that these polyhydroxamic acid polymers can be used in the research of biopolymers, because the polymers also have anticoagulant and urease inhibitory properties. The article proposes to use polymers as Ion exchange resin, but has not been suggested as any corrosion treatment In addition to the preceding article, in the following U.S. patent cases, we have also taught various amide and / or carboxylate polymers modified by reaction with hydroxylamine (please read the notes before Ml and fill in the notes Cross-dagger outfit-line. The paper standard Xiaoyongzhong ®® Home «Bi (CNS) Ή specification (210 > < 297 male dragon) 4 8 !. 7. 20ta〇〇iic (Η) Ministry of Economic Affairs Standards and Bureau Printed by β Industrial Consumer Cooperative 21S203 ---- V. Description of the invention () 1. U.S. 2,959,574 Woodbury, making the copolymer of propionyl nitrile and propionamide and hydroxylamine react to form copolymer The amine oxime composition teaches that the composition can be used as a precipitant or flocculant, and is used for the treatment of minerals or industrial wastes, for the treatment of gravel; as a coating composition for the production of films, production of packaging materials; Thickening agent; used as protective colloid, used as an admixture agent; and used as a mud mud additive. It has not been disclosed to use Woodbury's materials to inhibit the corrosion of iron and steel connected to industrial water. 2. US 4, 532 , 046 Meunier, et al. Teach a treatment by adding a water-soluble hydroxamic acid-containing polymer Agent, and the method of removing the scale of the soil test compound from the aqueous medium. Once again, Meunier has not taught the anticorrosive effect of iron or vehicles in contact with industrial water. Meunier emphasized that his polymer can be used as seawater as a scale inhibitor Precipitation of aged soil salt or limit the increase and size of precipitated salt crystals in the falcon soil, thereby suppressing the formation of scale on the surface in contact with seawater. 3. US Patent No. 4, 767, 540, Spitzer et al. Hydroxamic acid-containing polymers to reduce suspended solids in the Bayer process stream. The Bayer process stream processes raw bauxite and recovers aluminum trihydrate from it, which is then processed to recover aluminum and produce clay products. The operation of the Bayer process is extremely caustic and the level of dissolved solids is extremely high, requiring sedimentation and filtration to remove iron oxides and other contaminants. Once again, Spitzer ’s teachings do not mention the use of hydroxamic acid polymers to treat industrial water to suppress the corrosion of iron and iron in contact with industrial water. This paper size is used in a Β home tenon (CNS) 1Μ specification (210X297 male dragon) 81. 7. 20,000¾ (II) (please read the notes before entering # fill in this 1) Install-line-5- Λ 6 η 6

9/19 / 20S V. Description of the invention () The anti-corrosion effect. Please read first ik Contrary matters to be filled%-4. US Patent No. 4, 536, 296 Patent Case, Vi〇 teaches the use of clay-based water pore mud or complete mud, these mud and different Hydroxamic acid is formulated with a low molecular weight Dong polymer or copolymer of thiohydroxamic acid group. This patent case teaches the use of his polymer composition to generate extremely stable complexes of transition metals, thereby contributing to the dispersibility of the pore mud. According to the teachings, through the presence of aluminum, calcium, magnesium, iron and other ion-limiting ions on the clay, these polymers can be effectively absorbed on the clay particles, and when used as "dispersing additives" can provide obvious blocking or flow failure response. Again, this patent does not teach the use of this type of hydroxamic acid polymer as a corrosion inhibitor for industrial water. 5. US Patent No. 4, 810, 296, Guerro et al. Taught the use of hydroxamic acid / acrylamide polymers and copolymers to delay the settling time of cement slurry. The use of hydroxamated polymers in liquid cement slurry has nothing to do with its use in industrial water to prevent corrosion of steel in contact with industrial water. The Ministry of Economic Affairs is accurate and the A Industrial Cooperative Society printed 5i 6. US Patent Case No. 4, 868, 248 Patent Case, Sparapany et al. This patent case teaches a method for synthesizing polyhydroxamic acid polymers from polyacrylic acid. Again, this patent case does not teach the use of industrial water as an anti-corrosion agent to protect iron or wire from corrosion due to contact with industrial water. Therefore, an object of the present invention is to provide a method for suppressing corrosion of iron and soft pins in contact with industrial water by treating water with a hydroxamic acid functional group-containing polymer. Another object of the present invention is to use a molecular weight ranging from 2,000 to about 81. 7. 20,000¾ (II) This paper is used in the standard side a Η 極 楳 擳 (CNS) T4 specifications (210x297 g; it) 6 jt M AJ U Ο 1 5. Description of the invention (Polymer treatment industrial water in the range of 50,000, these polymers contain at least 1.01% of hydroxamate units distributed in the polymer structure by chance. Another purpose is to use a combination of polymers with iron and steel, especially soft nets, industrial water for contact, the combination contains scale inhibiting and / or dispersing polymers, which do not contain hydroxamic acid functional groups and contain Hydroxamic acid polymer. Finally, one object of the present invention is to use a hydroxamic acid functional group-containing corrosion-inhibiting polymer, or a carboxylate-containing scale inhibiting and / or dispersing polymer, and a hydroxamic acid-containing polymer. The combination of polymers of oxamic acid, the effective anticorrosive amount of treatment of these industrial waters * The combination of polymers is in the range of 10: 1 to 1: 10, and the combination is added to industrial water, based on the treatment Water, can provide 1 to 200PPJB hydroxamic acid polymer. So, this The invention provides a method for inhibiting corrosion of soft pins in contact with industrial water, the method comprising using a water-soluble polymer with an effective amount of corrosion protection, a weight average molecular weight ranging from about 2,000 to about 50,000, to treat industrial water , The polymer contains at least 1 mol% of hydroxamic acid structural element units with the following structural formula: (please read the back-end notes beforehand # 建 写 〆〆 乙二 汮 楾 貾 貾 絾 貓 則 局 Only working consumer cooperatives Printed ch2

R I

Γ NH I OH Ο This paper standard is used in a® Homewood Bi (CNS) T4 specification (210Χ297 & Λ) Ι. 7. 20 (000ik (Π) B 6 V. Description of the invention (where R is independently selected from Η, CH3 and mixtures thereof. The present invention also provides a method for inhibiting corrosion of soft pins which are exposed to industrial water containing any hardness ion selected from calcium, magnesium or mixtures thereof, the method comprising using the following polymers Combined treatment of the hardness-containing water: A. The molecular weight of the water-soluble polymer is between 1,000 and 50,000 and contains carboxylate functional groups, the polymer does not contain hydroxamic acid functional groups, and the carboxylate The functional group is derived from the presence of a polymer of unit units having the following structural formula:

H R-(-C- C ten

B C02H where R is H, CH3 or a mixture thereof; the standard of the Ministry of Economic Affairs, ^ β 工 消 " printed by the cooperative (please read the precautions first and then fill in " 1, ^-B is H,- C〇aH, -CH2COaH or mixtures thereof; wherein the mixture also contains 0 to 50 mol% of at least one monomer selected from the group consisting of propylene amine, methacrylamide, 2-acrylamide- 2-methylpropane sulfonic acid, hydroxypropyl acrylate, hydroxyethyl acrylate, N-tertiary butyl acrylamide, N-thiomethyl acrylamide, N-thioethyl acrylamide, Sulfonated styrene, vinyl sulfonate, isopropyl acrylate, and itaconic acid; and B_—a water-soluble polymer with a molecular weight between 2,000 and 50,000 and containing at least 1 mol% The unit of hydroxamic acid unit of the following structural formula is used in the paper scale. A Β home "Precision (CNS) T4 specification (210X297 public it) 8« 1. 7. 20,000¾ (||))

66 ΛΠ V. Description of the invention ()

R ~ ^ CH2— C-) —

C 0 The Central Standards Bureau of the Ministry of Economic Affairs β Engineering Consumer Cooperation Co., Ltd. produced HN-OH. Where R is selected from Η, CH3 and any of its mixtures, the polymer also contains 50 to 99 mol% At least one of the following monomers: acrylic acid, methacrylic acid, acrylamide, methacrylamide, hepatic maleate, hydroxypropyl acrylate, hydroxyethyl acrylate, N-tertiary butyl acrylate Amine, acrylamidomethylpropanesulfonate, thiomethacrylamine, thioethylacrylamide, sulfonated styrene, itaconic acid, and N-hydroxypropylacrylamide, and complex Wherein the weight ratio of polymer A to polymer B is between about 10: 1 and about 1:10 (The present invention also provides a method for inhibiting corrosion of soft meshes in contact with hard water, the method includes using an effective amount of corrosion-resistant polymerization A mixture of substances to treat the hardness water, the mixture comprising at least one of the following "A" polymers: w A "polymer 1. homopolymer of acrylic acid; 2. homopolymer of methacrylic acid; 3. acrylic acid Copolymer produced with at least one monomer selected from the group consisting of methacrylic acid and propylene Acetamide, hydroxypropyl acrylate, N-tertiary butylamide, ethyl-acrylamide-2-methylpropanesulfonic acid, thiomethacrylamide, thioethylacrylamide, and Itaconic acid; The standard of this paper does not use the Zhongming Mingjia Standard (CNS) T4 specification (210x297 mm) 81. 7. 20,000 ^ (11) (please read the precautions first, and then know how to do too much-order- Line-9

5. Description of the invention 4. A copolymer formed by maleic anhydride and at least one selected from acrylic acid, methacrylic acid, sulfonated styrene, vinyl sulfonate and itaconic acid; the "A "The polymer is mixed with at least one " B" polymer having the following structural formula: "R" party

R

R

-tCH2 ——C ^-'o = c OH-(• ch2 -ecK2 o = c nh2

R c = 〇NHI 01 H (please read the precautions first, then install, line. The Ministry of Economic Affairs standard and the β-consumer cooperation du printing system R is selected from H at each occurrence , CH 3 or its mixture; and there is the following relationship: (1) The sum of (a + b + d) is sufficient to provide a molecular weight in the range of 2, 000-50, 000; (2) 3 / (3+ 卜 + < 1) The ratio is in the range of 0,99 to 0_40; (3) The ratio of b / (a + b + d) is in the range of 0_30 to 0.0; (4) d / (a + b + d) The ratio is in the range of 0.01 to 0.30; and the mixture of the A polymer and the B polymer is in the range of 10: 1 to 1: 10 by weight. This inhibits iron in contact with industrial water And the method of corrosion of soft dysprosium is better than the standard of this paper. The national standard (CNS) T4 specification (210X297 public A) 10-8 !. 7. ⑻recognition (Π) 212208 Ministry of Economic Affairs Central Bureau of Administration β work elimination Printed by the Cooperative Society 5. Description of the invention () The polymers of Haowu have a molecular weight ranging from about 2,500 to about 25,000, and contain about 1.0 to about 30 · ο1% of the aforementioned hydroxamic acid unit units. The best industrial water uses polymerization with molecular weights ranging from about 5,000 to about 15,000 The Fanyuan treatment, and the polymer contains about 2.0 to about 14 mol% of hydroxamic acid unit. When referring to the hydroxamic acid unit, it means that when it exists, any water-soluble salt is present, For example, aged metal salts, aged earth metal salts, ammonium salts, protonated amine salts, or quaternary amine salts. In the practice of the present invention, the most effective amount of corrosion inhibitor for the polymer used to treat water in contact with iron and steel, Based on the weight of the treated water, between about 1 and about 200 ppm polymer; based on the weight of the treated water, preferably between 2 and 100 ppm polymer; and based on the weight of the treated water, the most It is preferably between 3 to about 50 ppbi polymer. The most preferred polymer is a copolymer or terpolymer containing at least 1 mol% hydroxamic acid unit units, preferably 1 to 30 mol% hydroxamic acid unit units. , Where the polymer also contains monomers or repeating unit units derived from monomers, the single system is selected from: acrylic acid, methacrylic acid, propylene amine, methacrylic acid amine, sulfonated monomers, for example 2-Acrylamido-2-methylpropanesulfonate, N-thiomethacrylamidoamine, N-thioethyl Acrylic amine, sulfonated styrene, vinyl sulfonate, maleic anhydride, itaconic acid, hydroxypropyl acrylate, hydroxyethyl acrylate, N-tertiary butyl acrylamide, etc. It is easy to use copolymers, terpolymers or higher polymers containing element units obtained by polymerization of acrylic acid, methacrylic acid, acrylamide, methacrylamide, etc. in addition to the hydroxamic acid repeating element units (Please read the back and attention matters #filling, knowing, > loading · line. The SIL standard of this paper is in use "« Household Bi (0 old) 〒 4 specifications (210 to 297 public goods) 81. 7. 20,000 ^ (| [) -11-% 212203 Λ 6 Π 6 V. Description of the invention (The best polymer containing hydroxamic acid units is the polymer with the following structural formula:

R

R

R

ch2— C c = o

OH

CH r CH- b t c = o c = o (Please read the precautions before filling in ΝΉ-

NH OH equipment * The Ministry of Economic Affairs, Yan Yang, persuaded the EC industry and consumer cooperation du printing system that R is selected at each occurrence. From hydrogen, methyl and their mixtures, and a, b, d have the following relationship: (1 ) The sum of (a + b + d) is sufficient to provide a molecular weight between about 2,000 and about 35,000; (2) The ratio of d / (a + b + c> is in the range of about 0.30 to 0.01; 3) b / (a + b + c> ratio is in the range of about 0.3 to 0.0; (4) a / (a + b + c) ratio is in the range of about 0.99 to 0.40. Preferably, The aforementioned hydroxamic acid polymers are those in which R is Η and a, b and d have the following relationship: (1) The sum of (a + b + d) is sufficient to provide between about 2,500 and about 25 ， 000 molecular weight; (2) d / (a + b + d) ratio is in the range of about 0.14 to about 〇2; (3) b / (a + b + d) ratio is about 0.30 To the range of about 〇〇〇1; Line · This paper scale side uses the Chinese "Home" standard (CNS) T4 specifications (210> < 297 male dragon) 81. 7. 20,000 ^ (11) -12-212208 Λ 6 Π 6 The Ministry of Economic Affairs is accurate and only works. "Cooperative Duprinting. V. Description of Invention () (4) The ratio of a / (a + b + d) is in the range of about 0.97 to about 0.56; , Which is based on the treated water , The amount of polymer is from 1 to -100 ρρ »polymer. As can be seen above, the best polymer contains acrylic acid or methacrylic acid, and optionally contains propylene amine or methacrylic acid amine with hydroxamic acid A polymer of functional groups that repeats the unit of the skull. Again, the acid unit in the aforementioned polymer may exist as its SI (as described above). Although, as will be seen later and as taught by the prior art, it is known Hydroxamic acid-containing polymers can be used as scale inhibitors, but these polymers are not preferred scale inhibitors. However, the hydroxamic acid polymer of the present invention can be used in combination with other polymers, which will be described later It is a scale-dispersing and / or scale-inhibiting polymer. It is better to use hydroxamic acid polymer treatment when implementing our corrosion control method for mild steel and iron in contact with industrial water containing hardness ions Adding a scale inhibitor or dispersing polymer; or the polymer does not contain hydroxamic acid functional groups. These polymers are mainly water-soluble polymers with a molecular weight of 1,000 to 50,000 and containing carboxylate Functional group, the polymer once again does not contain hydroxamic acid functional groups, and the carboxylate functional groups obtained from repeating unit units of the polymer are often distributed at random opportunities and have the following structural formula: HR -f-C-C 十 BC 〇2H The size of this paper is as low as CNS T4 specification (210X297 g *) 8 丨 .7.2 (), 000ik (丨 丨) 212203 Λ 6 Π 6 Ministry of Economic Affairs, Central Standard: Γ Printed by A Gong Xiaozhi Cooperative V. Description of the invention () where R is hydrogen, methyl or a mixture thereof; B is hydrogen, -C0aH, -CHaC08H, or a mixture thereof; the polymer also contains 0 to 50 1% of at least one selected from the group consisting of: propylene lauramine, methacryl acetamide, hydroxypropyl acrylate, hydroxyethyl acrylate, N-tertiary butyl propenamide, N-methyl methacrylate Propylamine, N-ethyl ethyl acrylate, AMPS, sulfonated styrene, vinyl sulfonate, itaconic acid, etc. The main examples of such scale inhibiting / dispersing polymers are acrylic acid or methacrylic acid or both. These acrylic or methacrylic acid polymers may be homopolymers, copolymers, or terpolymers or higher polymers, but preferably contain acrylic acid, methacrylic acid, maleic anhydride, itaconic acid, or several Carboxylate-containing monomer units, the monomer units or the combination of monomer-containing units accounting for at least 50% of the total monomers used in the synthetic polymer. Scale inhibiting and / or dispersing polymer When used in combination with our hydroxamic acid-containing polymer, the weight ratio of scale inhibiting / dispersing polymer to hydroxamic acid polymer is preferably between about 10: 1 To about 1:10, preferably from about 5: 1 to 1: 5. When a combination of polymers is used, the combination is usually added to water, so that based on the water being treated, the combination provides from 1 to 200 ppm of polymer of isocyanic acid. The best scale inhibiting / dispersing polymer is acrylic acid * methacrylic acid, or maleic anhydride homopolymer; and copolymers containing acrylic acid, or methacrylic acid, or both, the copolymer also contains selected At least one monomer from the following: acrylamide, methacrylamine, maleic anhydride, hydroxypropyl acrylate, hydroxyethyl acrylate, N-tertiary butyl acrylamide, 2-acrylamide Amino-2-methylpropane sulfonate, thiomethacrylamide, thioethyl (please read the precautions before filling in I λ)

The standard size of the paper is used in the "B" (CUS) T4 specification (210X297 g *) 81. 7. 20,000 ^ (11) 9,12208 Λ 6 η 6 Printed by the Ministry of Economic Affairs + Central Bureau of Standards A Gongxiao Wu Cooperative Society 3i 5. Description of the invention () Acrylamide, sulfonated styrene, vinyl sulfonate, itaconic acid, and N-hydroxypropylacrylamide. These polymers usually contain at least 40% of acrylic acid, methacrylic acid, or a mixture thereof, and the difference is a polymer containing at least one of the aforementioned single-unit units (or meta-units). Other monomers may also contain acrylic acid with these , Methacrylic acid, or butylated dianhydride, itaconic acid, and polymers of other units mentioned above. Other monomers include acrylonitrile, methacrylate, ethyl acrylate, etc., but due to these monomers It is mainly hydrophobic but not hydrophilic, so the content of hydrophobic monomers is usually limited to less than Ι0βοΙ%, preferably less than 5mol%. The molecular weight of water-soluble scale dispersion and / or inhibitory polymers is between 1,000 and 50 ， 000, preferably from 2,500 to about 35,000, most preferably from about 3,000 to about 25,000. When using scale inhibition / dispersing polymer, it can be used with hydroxamic acid polymer It can be used alone or mixed. The combination contains any polymer derived from any of the above definitions, but preferably the combination used contains acrylic acid homopolymer, methacrylic acid homopolymer, copolymer of acrylic acid and at least one monomer selected from the following: A Acrylic acid, acrylamide, methacrylamide, hydroxypropyl propionate, N-tertiary butyl acrylamide, 2-propenylamino-2-methylpropanesulfonic acid, thiomethacrylic acid Acetylamine, acetylethylacrylamide * and itaconic acid; and a copolymer of maleic dianhydride and at least one monomer selected from the group consisting of acrylic acid, methacrylic acid, vinyl sulfonate, benzene Ethylene sulfonate, itaconic acid, etc. 0 (Please read the precautions before filling in ^ Packed · This paper is used in the standard "楳 楳 准 (CNS) T4 specifications (210x297 public: ¢) -15-81.7 . 20,0 () () ¾ (ϋ) 212203 A 6 Π 6 V. Description of the invention () The term hydroxypropyl acrylate represents the ester group obtained by the reaction of pentaenoic acid with propylene oxide: 0 ch3II I-co-ch2-ch-oh O CH, II I-C-0-CH-CH2〇H or any mixture of its structural formula. When combined with scale inhibiting / dispersing polymer, ie eight polymer ' In use, the hydroxamic acid-containing polymer, 卽 B polymer, preferably the aforementioned terpolymer * The terpolymer has the following structural formula:

H RIc—c

-2 H Please read the notes on the back. M.%

H

Η R—? ; Lc IN Η2 printed by the Ministry of Economic Affairs, Shiyang, Zhuo, and Rongshi Consumer Cooperatives R— 十 —c = —raIο— Η where R is selected from hydrogen, methyl, or a mixture thereof, and the following items exist: (1 ) The sum of (a + b + d) is sufficient to provide a molecular weight range of 2,000-50,000; the paper size is used in the ass standard (CNS) TM specification (210x297; It) 81. 7. 20,000¾ (H) -16-212203 Λ 6 η 6 Ministry of Economic Affairs Standard Standard β 工 消 # Cooperative Society Printing Ⅴ 5. Description of Invention () &lt; 2) a / (a + b + d) ratio is between 0.99 To a range of 0.40; (3) b / (a + b + d), with a ratio between 0.30 and 0.0; &lt; 4 &gt; d / (a + b + d) with a ratio between 0.01 and 0.30 Fanyuan; as mentioned above, the acid element units containing carboxylic acid or hydroxamic acid or both may exist in the form of a salt or a mixture thereof. When these mixtures are used, Group A polymers (scale inhibitor / dispersible polymers) and Group B polymers (containing hydroxamic acid polymers) are in the range of 10: 1 to 1: 10, preferably 5: 1 It is used in a weight ratio of 1: 5. As mentioned above, when combined, the combination is preferably added to water containing hardness ionized water such as calcium, magnesium, etc., the so-called "hard water", based on the weight of the hard water subjected to treatment, provided From about 1 to about 50 ppb of hydroxamic acid polymer in hard water. In addition to using the hydroxamic acid polymer of the present invention to inhibit corrosion, other anti-uranium cocoon-made cocoons are also expected to be compatible with these polymers, iron and At the time of industrial water connection, known corrosion inhibitors are used in combination. These corrosion inhibitors include orthophosphate esters, organic phosphate esters, phosphonate esters, polyhydric alcohol phosphate esters, and mixtures thereof. Also contain zinc ions, inorganic complex salts , And other materials that can be protected from corrosion when the iron and pin materials are exposed to industrial water. When using other corrosion inhibitors, it is better to use orthophosphate or orthophosphate sources, orthophosphonates Such as 1,2,4-tricarboxy-2-phosphino-butane (common name PBTC) and HED P, (dihydroxyethylidene) II-phosphonic acid or the so-called Dequest® product. Dequest® is a registered trade name of Monsanto Co. The hydroxamic acid polymer of the present invention can be partially or completely substituted, and the normal organics known in the industry Phosphonate corrosion inhibitor. When the organic phosphonic acid is completely replaced (please read the precautions first and then fill in k &gt;), this paper is used in the 5 Burg standard (CNS) T4 specification (210X297; «:) 81. 7. 20,000 ^ (11) 17-Λ 6 η 6 212203 V. Description of the invention () (please read the back-end notes #fill k &gt;) for esters, the hydroxamic acid polymer of the invention It is as effective as anti-corrosion in organic anti-corrosion. When it partially replaces organic trans-ester, it is a formulation agent containing a mixture of organophosphonic acid and the hydroxamic acid polymer of the present invention, especially for scale inhibitor / dispersible polymer. In the presence, it can not only provide excellent anti-corrosion effect, but also provide excellent scale protection effect. To illustrate our invention, provide the following experimental information. Fu Yan example In the following experiment, several experiments were carried out. The test summary is as follows: And hh test, borrow , Magnesium, Inhibitor Test Polymer and Bismuthate are added to the Deionization Department to prepare the test solution in the sub-water produced by the Ministry of Agriculture, Industry and Consumer Cooperation. The initial concentration of salt should be: 360ppb Ca * 2 , 200 ppb Mg &quot; 500 ppb HC〇3- (both in the form of CaC〇3> and 5, 10 or 15 ppm inhibitor test polymer, expressed as polymer activity / solids. The temperature is maintained at 140 ° F (60T) The solution is stirred at any time, and the pH is continuously monitored. The solution is titrated with dilute Na0HK at a steady rate. The pH of the test solution is slowly increased by adding NaDH, then slightly lowered, and then raised again. The maximum pH before Shen Xushi was slightly lowered was the inflection point PH. The mineral solubility computer program was then used to calculate the super saturation ratio of calcium masterate based on the test conditions at the inflection point pH. This supersaturation ratio is related to the performance of calcium carbonate inhibitors. Repeat the test procedure for different inhibitor solutions and doses. Before the next test round, dilute HC1 must be used to remove all calcium nitrate precipitation from the test device. Carbon phenol calcium pomelo test calcium, magnesium, test polymer inhibitors and bicarbonate added to deionized water to prepare a test solution with 360ppm Ca * 2, 200ppm Mg * a, 500 The paper size is easy to use in S countries (〇 奶) 〒 4 specifications (210x297 g) 81. 7. 20,000ik (II) 212203 Ministry of Economic Affairs t 揣 斣 華 華 Α 工 消 # Cooperative society printed 5i V. Description of the invention () PPm HC03- (all in CaC〇 3) and 5, 10 or 15 ppm inhibitor, expressed as actives / solids. Collect the initial sample of test water to analyze calcium by atomic absorption. The test temperature is maintained at 140T &lt; 60t!). Dilute NaOH was used to slowly increase the pH of the solution to 9.0, and this value was maintained during the 2 hour test period. In the test results, a small amount of solution will be filtered (<0.45 tfm) and the concentration of nitrate will be determined by atomic absorption. Allow the rest of the unfiltered samples to settle without interference until 24 hours. After 24 hours, water was collected from the top of the flask and calcium was analyzed. Calculate the% inhibition and% dispersion in the following manner: ppm Ca 〃 After filtration% inhibition = -X 100 ppm Ca + B initial ppm Ca &quot; unfiltered, precipitated% dispersion = -X 100 PP m C a ♦ 8 Initial lightning test The Taf el chart and the linear resistance test are performed under the same water chemistry and conditions. A test solution for electrochemical corrosion cells was prepared by adding calcium, magnesium, various inhibitors, and bibasic acid salts to deionized water to obtain 360 ppm Ca · 3, 200 ppm Mg * a, and 440PPΠ1 HCO · 3 (both in the form of CaC03). The temperature is maintained at 120T and the solution is ventilated throughout the test. The pH is not controlled. Assemble the quasi-three-electrode battery for polarization study. The pre-polished soft mesh sample was used as a rotating working electrode at 500 rpm. All potentials are measured on the saturated calomel reference electrode. Use Ershiyong as the counter electrode. The measurement of the polarization resistance was carried out at a corrosion rate of ± 20mV at a scan rate of 0.4 IV / sec. From the corrosion potential, the M anode and cathode polarized the mild steel sample at 250 mV to draw a Tafel picture. Read the meaning of the opposite and then fill in%. Η This paper is edged and used in China National Standard (CNS) T4 (210X297; ¢) 81. 7. 20, 0 () 0¾ (II) -19 Λ 6 Π6 9,12203 V. Description of the invention () (Please read the notes on the contrary to write ^ .K) For the calculation of the saturation ratio, please refer to "Computerized Water Model for Design and Operation of Industrial Cooling System", see October 1980 The 41st Annual Meeting of the International Water Conference held in Pichai, Pennsylvania from 20 to 22nd. This report is also described here for reference. The saturation ratio test is related to the formation of scale above a certain critical pH. Subsequently, sodium hydroxide was added to the test solution to raise the pH and allow the test water to reach the pH at the inflection point. Nucleation and crystal growth occurred during the test. The inflection point pH is used in the computer program of the report described above to calculate the saturation ratio. This value is simply an index for predicting the tendency of calcium silicate precipitation. The computer program calculates the saturation ratio based on water composition, operating conditions, temperature, inflection point pH, concentration cycle, and acidic pH control. The program can also complement the effects of temperature, ionic strength and ion pairing. The further the saturation ratio is, the better the polymer will be as a scale inhibitor. The common name of calcium carbonate inhibition test is "stirring and sedimentation test". This test provides information on% inhibition and% dispersion of specific scale inhibitors. Description of inhibitory effect By preventing the growth of calcium carbonate, the ability to limit the formation of scale salts such as calcium sulfonate is limited. Dispersion invents the ability of a chemical to prevent particles from settling for a long time. The performance is determined by measuring the atomic absorption of calcium, and the higher the% inhibition and% dispersion, the better the effectiveness of the polymer as a scale inhibitor. Printed by the Ministry of Economic Affairs and the Central Bureau of Industry and Commerce β Cooperative Cooperative Society. Electrochemical tests provide Tafel diagrams and linear partial resistance data to measure the corrosion resistance. This active M corrosion rate reports that the lower the corrosion rate, the better the effectiveness of the polymer as a corrosion inhibitor. A representative example of the polymer is the polymer described in Table 1. 81. 7. 20,000 ^ (11) The original size of this paper is 5GB, which is used in the Chinese National Standard (CNS) Τ4 specification (210x297 g *) 2122G3 Λ 6 Π 6 5. Description of invention ()

Table I Estimate of polymer molecular weight by the Ministry of Economic Affairs and the standard of β Gongxiao & Co., Ltd. printed 94 mo 1% acrylic acid 6 mol% (CHa-CH) 0 = C- ΝΗΟΗ 90 mo 1% propionic acid 10 mol % (CHa-CH) 0 = C-NHOH 100 mol% acrylic backbone polymer 89% acrylic acid 5% acrylamide 6% hydroxamic acid unit * 70% acrylic acid 19% acrylamide 11% hydroxamic acid Element unit 53% acrylic acid 18% acrylamide 29% hydroxamic acid element unit 83% acrylic acid 9% acrylamide 8% hydroxamic acid element unit 6 * 000- 7 »000 6. 000- 7» 000 6 &gt; 000- 7, 000 12, 000-13, 000 12, 500-13, 500 12, 700-13, 700 12, 500-13, 500 (please read the notes on the back # fill in I, Binding-Stranding _ This paper is used in the "B Jia Yu Bi (CNS) T4 specification (210x297 mm) -21-81. 7. 20,00Uik (ll)

Howl 2122M V. Description of the invention (* Book 8 50-60% acrylic acid 14-20% thiomethacrylamide 20-36% acrylic acid 18, 000-19, 000 *** 10 55-65% acrylic acid 15 -25% methacrylic acid 10-30% N-tertiary butylacrylamide polyacrylic acid homopolymer neutralized with sodium hydroxide 15 * 000-16. 4,000- 7,000 500 (please read the back first Precautions' φ 塡 Tips 4 ^ Copolymer of acrylic acid and isopropyl ester of acrylic acid (ester content is 6-10 mol%) 4 * 〇00-7 »500 Pack_ Other Sickle PBTC-1, 2, 4-Tri-carboxy-2-phosphino-butane HEDP- (1-hydroxyethylidene) II-phosphonic acid * Hydroxamic acid unit = (CHS-CH) 0 = C- ΝΗ0Η ** Molecular weight is by weight The average molecular weight is estimated by gel permeation chromatography using polystyrene sulfonate sassafras. *** Polymers 3, 8, 9, 10 and 11 are "scale inhibitor / dispersible polymers" Representative example. Line-Ministry of Economic Affairs standard and beta work permit cooperation Du Yin 51 81. 7. 20,000 ^ (K) This paper & used in the "ffl home standard Bi (CNS) 4 specifications (210x297 ; it) 22 212 ^ 03 Printed by the Ministry of Economy + Central Bureau of Standards β Industrial and Consumer Products Cooperative Description () Use the listed polymers for various tests * and in the so-called "stirring and settling" test, the Landing saturation ratio,% inhibition * and% dispersion, and the electrochemical screening test are used to prevent corrosion rate and corrosion rate. The water chemistry and test conditions and results are listed in the following Tables II, III and IV. Table Π Saturation ratio test Yonghuali / Yuyou: 360ppm Ca / 200ppm Mg / 500ppm HC〇3 (as CaC〇3) Temperature: 60t! , Stirring rate: 300 rpm Titration_: 0. ION NaOH Dose: 5, 10 and 15 ppm Standard deviation of active material saturation ratio: 6.6 Saturation ratio of blank group: 3.0 Polymer 5 ppm Saturation 10 ppm ratio 15 ppm 1 40.9 128.9 130.7 2 43.4 97.1 124.7 3 97.1 125.9 131.9 4 46.4 112.3 127.9 5 62.3 106.0 127.9 6 36.8 53.9 76.9 7 62.3 106.0 118.6 This paper ruler A is used in the "B Family Standard (CNS) Τ4 specification (210 to 297 public) 81. 7. 20 ( 000ik (H) (Please read the precautions first and fill in i.K) Γ spring 212203 Λ 6 Β6 V. Description of invention () Table I Stirring and sedimentation test Taihua a / fe piece: 360pp · Ca / 200ppu Mg / 500pp · HC〇3 (as CaC〇3> temperature: 60t :, Stirring rate: 250rpn Titrant: ION NaOH, pH: 9.0, 2 hours blank group: 0.6% inhibition, 1.3% dispersion polymer saturation ratio 5ppm ΙΟρρη 15ppm 1% inhibition 39.6¾ 53.1¾ 61.4% 96 dispersion 40.2% 59.3% 75.896 (please read the notes beforehand, and fill in 4k). The Ministry of Economic Affairs, the central government, quasi-Λβ 工 消 # Cooperative print ¾ Table W Several hydroxamic acid-containing polymers are used for anticorrosion of soft vehicles Electrochemical screening test hydration / condition: 360PPin Ca / 200ppid Mg / 440 HC03 (in the form of CaC〇3) Temperature: 120 ° F, pH: uncontrolled, air-stirred unpolished soft steel sample, 30-minute delay time ， 500rpm Corrosion speed _ 榡 quasi difference: soil 〇.345mpy SB family tree (CNS) T4 specifications (210x297 public address) on the paper standard for free use 81. 7. 20,000ik (ll) 212203 Λ 6 η 6 hair f Wuming Description () The Ministry of Economic Affairs, Bureau of Accreditation, β-Consumer Goods Cooperative printed polymers such as: (A) 20ppb inhibitor, 〇ρρ · PBTC, 15ppb polymer 8 &lt; B) ΙΟρρι inhibitor, 10ppm PBTC, 15ppb Polymer 8 (C) 10pp Li inhibitor, IOppb PBTC, 15ppm polymer 8 Polymer inhibition Single rate (npy) (A) (B) (C) 1.18 3.96 1.53 2 1.84 1.39 0.95 4 0.38 .84 1.98 5 .50 .34 1.81 6 3.13 .88 .79 7 2.24 .76 1.04 blank * 8.63 .98 1. 92 Other details: 20ppb polymer 2, ΙΟρρβ PBTC, lOppn polymer 8 · 0.75mpy 15ppm polymer 2, 5ppm PBTC, 15ppm polymer 8: 1.39rapy 20ppm polymer 5, Oppm PBTC, 15ppm polymer 10 : 〇.75mpy (20ppm polymer 5, Oppm PBTC, 15ppin polymer 11: l.〇3nipy ih first read back to the meaning of ## 才 一 丁% This paper is used in the standard B® home dazzle (CNS) &lt; F4 specification (210X297; ":") 25 81 · 7. 20,000 ^ (1)) 212203 Λ 6 η 6 V. Description of the invention (Party meeting: lOppai polymer 5, 10ρρ · polymer 11, I5ppm polymerization 8: 0.34Bpy 10ρρ · polymer 5, 10ppb polymer 10, 15ρρ · polymer 8: 0.73mpy 10ρρ · polymer 5: 6.0npy 20ρρ · polymer 5: 1.75aipy 15ρρ · polymer 11: 1.27mpy 15ρρ · Polymer 10: 2.71mpy (average> blank group without inhibitor: 31.05npy * does not contain hydroxamic acid polymer, but contains all For the other treatments. ** Without processing. Do not read the notes before you fill in, and then fill in% The standard of the Ministry of Economic Affairs: iTG: Industrial and Consumer Cooperation Du Printed The above test results clearly show that the hydroxamic acid polymer of the present invention can react with hardness alone or in particular Polymers, such as the aforementioned carboxylate-containing polymers, are incorporated to inhibit the corrosion of nets in contact with industrial water. At the same time, the hydroxamic acid polymer itself or in combination with the hardness-reactive polymer can suppress iron and steel in contact with industrial water in the presence of iron or pins in industrial water in the presence or absence of other known corrosion inhibitors Of corrosion. As can be seen from the results in Table IV, when used in combination with phosphonates, or when used alone in the absence of such organic phosphonate corrosion inhibitors * can be used to replace organic phosphonates. The size of this paper is used in the "standard (CNS)« f 4 specification (210X297 «) 81. 7. 20,0 () 〇ik (II)

Claims (1)

1 2 Announcement printed by the Beigong Consumer Cooperative of the Central Bureau of Standards of the Ministry of Economic Affairs A7 B7 C7 D7 VI. Application for Patent Fan Yuan No. 81 105596 Application for amendment of the scope of patent application This amendment date: June 82 1. A method of suppression and industrial water use A method for corrosion of contacted mild steel, the method comprising treating industrial water with a water-soluble polymer having a weight-average molecular weight ranging from about 2,000 to about 50,000 in an effective amount of corrosion protection, the polymer containing at least 1 mol% The hydroxamic acid structural unit unit having the following structural formula: RI ~ {CH2-Cf-C = ΟΗΗ L Where R is independently selected from Η, CH3 and mixtures thereof. 2. The method as claimed in item 1 of the patent application, wherein the polymer has a molecular weight in the range of about 2,500 to about 25,000 and contains about 2.0 to about 30 mol% of the unit of isobaric acid. 3. The method as claimed in item 1 of the patent application, wherein the polymer has a molecular weight of about 5,000 to about 25,000 and contains about 2.0 to about 14 mol% of hydroxamic acid unit units, or alkali metals, Earth metal, ammonium, protonated amine, or quaternary amine salt. 4_ The method as claimed in item 1 or 2 of the patent application, in which the effective anticorrosion amount of the polymer used to treat the water, M is the weight of the water to be treated, which ranges from about 1 to about 200 ppm polymer. The size of this paper is in accordance with Chinese National Standard (CNS) A4 specifications (210 X 297 mm) (please fill in item f before filling in the purchase) •• Binding_ • 4. 212203 A7 B7 C7 D7 Patent application 5. For the method of applying for the first item of the patent scope, the polymer has the following structural formula: R Η R (please pay attention to the precautions on the deposit page) τ fpH2— c} CH: — C CH- bc = o co c «o loaded OH NH 2 NH OH Ordered by the Ministry of Economic Affairs Central Bureau of Standards R Industrial and Consumer Cooperatives and printed a, b and d have the following relationship: (1) (a + b + d) is sufficient Provide molecular weights ranging from approximately 2,000 to approximately 35,000; (2) d / (a + b + d) ratio ranging from approximately 0.30 to 0.01; (3) b / (a + b + d> The ratio is in the range of about 0.3 to 0.0; the ratio of (4> a / (a + b + d) is in the range of about 0.99 to 0.40. * 6. For the method of claim 5 of the patent application range, where R is Η, and ab and d have the following relationship: (1> (a + b + d) is enough to provide a molecular weight in the range of 2,500-25,000;. The size of the line paper is applicable to the Chinese National Standard (CNS) A 4 Specifications (210 X 297 mm) 2 212203 A7 B7 C7 D7 Central Bureau of Standards of the Ministry of Economic Affairs 8 Industrial and Consumer Cooperatives Printed S. Patent application for Fan Garden (2) d / (a + b + d) ratio between 0.14 to 0.02 range; (3> b / (a + b + d) tb is between 0.30 The range of 0.01; (4) The ratio of a / (a + b + d) is in the range of 0.97 to 0.56; again based on the weight of the water treated, the amount of polymer used is from 2 to 100 ppm polymer. 7.— A method of inhibiting corrosion of a soft pin with industrial water containing europium in the hardness of any hardness selected from calcium, magnesium, or mixtures thereof, the method comprising using the following polymer combination to treat the hardness-containing water: A. The water-soluble polymer has a molecular weight of 1,000 to 50,000 and contains a carboxylate functional group. The polymer does not contain a hydroxamic acid functional group. The carboxylate functional group is derived from the following structural formula The existence of the polymer of the element unit: HR 十 C——c 十 ♦ BC〇2H 'where R is H, CH3 or a mixture thereof; B is H, -C〇aH, -CHaC〇aH or a mixture thereof; and The polymer also contains 0 to 50 mol% of at least one monomer selected from the group consisting of acrylamide, methacrylamide, 2-propenamide-2-methylpropane sulfonic acid, and hydroxypropyl Acrylate, hydroxyethyl acrylate, N-tertiary butylacrylamide, N-thiomethacrylamide, N-thioethylpropane Enylamine, sulfonated styrene, vinyl sulfonate --Line {f (please read the $ face note first and then fill in this page) This paper scale is applicable to China National Standard (CNS) A 4 specifications (210 X 297 mm) 3 212203 A7 B7 C7 D7 Group acid esters, isopropyl acrylate • and itaconic acid; and B.—a water-soluble polymer with a molecular weight of 2,000-50, 000 and containing at least 1 mol% of isohydroxyl having the following structural formula Unit of the acid element: R -fCH2— C · ^-(Please read «Notes on the back * and then« write this page} C Ο ΗΝ-OH where R is selected from Η, CH, and mixtures of them In any case, the polymer also contains 50 to 99 mol% of at least one monomer selected from the group consisting of acrylic acid, methacrylic acid, acrylamide, methacrylamide, maleic anhydride, and hydroxypropyl Acrylic ester, hydroxyethyl acrylate, N-tertiary butyl acrylamide, propylene aminomethyl propane sulfonic acid, thiomethyl acrylamide, thioethyl acrylamide, sulfonated benzene Ethylene, Itaconic Acid, and N-Hydroxypropyl Propylamine And again, the weight ratio of polymer A to polymer B is between about 10: 1 and about 1:10. S _ The method as claimed in item 7 of the patent scope, wherein: the aforementioned polymer A is selected from: homopolymers of acrylic acid, methacrylic acid, and maleic dianhydride and selected from: acrylic acid and at least one monomer selected from the following Homopolymer of the body: methacrylic acid, maleic anhydride, propylene amine-binding · binding '. Line · Printed by SK Industrial and Consumer Cooperative of Central Standards Bureau of Ministry of Economy and Economy. The paper size is applicable to the Central Park National Standard (CNS) A 4 specifications (210 X 297 mm) 4 212203 A7 B7 C7 D7 Central Standards Bureau of the Ministry of Economic Affairs®C Industrial and Consumer Cooperatives Printed and patented Fan Garden, methacrylic acrylic, hydroxypropyl acrylate, N-tri Grade butylacrylamide, sulfonated styrene, vinyl sulfonate, and itaconic acid; and polymer B contains 1 to 30 mol% of the following element units: RI -fCHj— 〇) — IC = 〇I NHI OH and 99 to 70 mol% of at least one monomer selected from the group consisting of acrylic acid, methacrylic acid, acrylamide, methacrylamide, thiomethacrylamide and thioethylacrylamine; Again, the weight ratio of A: B polymer ranges from 5: 1 to about 1: 5. 0 9 . A method of inhibiting corrosion of mild steel in contact with hard water, the method comprising treating the hardness water with an effective anticorrosive amount of a polymer mixture, the mixture including at least one of the following “A” polymers «“ A ” Polymer (1> Homopolymer of acrylic acid ;, (2) Homopolymer of methacrylic acid; (3) The total of acrylic acid and at least one monomer selected from the following (please read the notes on the back first (Fill in this page)-丨 Package · Order · .Line. This paper scale is applicable to China National Standard (CNS) A 4 specifications (210 X 297 mm) 5 A7 B7 C7 D7 #, Patent application Fanyuan polymer: methacrylic acid, acrylic amide, hydroxypropyl acrylate, N-tertiary butyl amine, 2-acrylamido-2-methylpropane sulfonic acid, thiomethyl acryl Acetamide, thioethylacrylamide, and itaconic acid; (4) Maleic anhydride and one selected from acrylic acid, methacrylic acid, sulfonated styrene, vinylsulfonic acid, and itaconic acid Copolymer produced from at least one monomer; the "A" polymerized The substance is mixed with at least one "B" polymer having the following structural formula: "B" polymer R R R Where R is selected from H, CH3 or a mixture thereof at each occurrence; and there is the following relationship: (1) The sum of U + b + d) is sufficient to provide a molecular weight in the range of 2,000 to 50,000; (2> a / (a + b + d) ratio is in the range of 0.99 to 0.40; (3) b / (a + b + d) ratio is in the range of 0.30 to 0 · 0; ---- ------------- ^ --------- ^ ------ # ----- (please read the note $ item on the back first and then «write this ranunculus ) This paper scale is applicable to the Chinese National Standard (CNS) A4 specifications (210 X 297 mm) 6 A7 212203 c? One D7 6. The patent application park (4> d / (a + b + d) ratio is between 0.01 to 0.30; and the mixture of "A" polymer and "B" polymer is in the range of 10: 1 to 1:10 weight ratio (^. 10 _if patent application The method of item 9, in which the mixture of the "A" and "B" polymers is added to the hard water, thus providing 1 -50ppm of the "B" polymer based on the treated hard water. 11. If the scope of patent application is 1, 2, 3 , 5, 6, 7, 8, 9 or 10, wherein the other corrosion inhibitors are selected from the group consisting of orthophosphate, (1-hydroxyethylidene) -phosphonic acid (H EDP), 1,2,4-tricarboxy-2-phosphino-butane (PBTC), tolyltriazole, zinc hair, chromate, nitrous acid / nitrate salt, and polyphosphate (Please follow the precautions on the Htpip page before writing this page) Order · .Line · Printed by the Central Standards Bureau of the Ministry of Economic Affairs of the Ministry of Economic Affairs and Consumers Cooperatives. The paper standard is applicable to the Chinese National Standard (CNS) A 4 specifications (210 X 297 Goods) 7