How to use international patent classification number for patent retrieval

Mastering the patent classification table is an important link in patent literature retrieval. All countries in the world generally have their own patent classification tables, and the classification principles, classification systems and marking symbols adopted are different. In view of the fact that invention is a product of human thinking activities and a valuable property of human beings, patent classification should be unified internationally to solve the inconvenience caused by adopting different classifications in various countries, and IPC came into being under this background. For more than ten years, countries have adopted the international patent literature classification system in addition to their own patent classification systems. For example, Japan adopted the classification system of International Patent Classification (IPC) and Japanese Patent Classification (JPC) from 1970, and completely changed to IPC system from 1980. IPC system classifies patent documents in any special field in a unified way, thus providing convenience in the process of sorting, transmitting and retrieving patent specifications. Practice has proved that users can find some patent specifications related to key technologies through IPC system, and understand the current world level or development trend of a technology through synthesis, analysis and statistics, so as to be inspired, generate new inventions and further make new inventions. The worldwide international patent classification table came into effect in September of 1968 and 1 and has been extended to 50 countries. 17 was revised four times in June, and now it is the fifth edition of 1990 which came into effect in September. Patent specifications published by major industrial countries are now printed with international patent classification numbers, and patent retrieval reference books in some countries have been arranged according to international patent classification, such as a set of Soviet and foreign inventions 1972 edited and published by the Institute of Patent Information and Technical and Economic Sciences of the former Soviet Union. France, the former Federal Republic of Germany and Japan abandoned their patent classification in 1969, 197 1 and 1980 respectively and started to use IPC. The information in the patent office has been changed to IPC, and the published retrieval tools (bulletins and indexes) have also been changed to IPC. Other countries, such as the United States and Britain, are still in a transitional stage. PCT patent (patent cooperation tready) and European patent also use this classification table, and the British World Patent Index also uses IPC as the main classification retrieval method. China's patents also adopt the International Patent Classification Table. Therefore, it is very necessary for engineers and technicians to master this classification table, whether from the perspective of using foreign patent documents or from the needs of invention management in China. 2.2 structure. The international patent classification system of IPC system is divided into five levels: department, category, sub-category, large group and small group, involving all technical fields related to invention patents. It is divided into eight parts (including several sections), represented by eight capital Latin letters A, B, C, D, E, F, G and H; There are classes in subordinates, expressed in Arabic numerals; Under the big category is the sub-category, which is represented by capital Latin letters; Under small categories, there are large groups and subgroups, which are represented by Arabic numerals. Separate large groups from small groups with a slash "/". For example: C 07 C47/00 | | | | 8 There are 8 volumes of major categories, minor categories and major groups. The content of each department is divided as follows: Part A is "necessary for human life", including agriculture, food, household goods, furniture, health care and entertainment goods (*** 15 category). Part B "Operation and Transportation" includes various operations and equipment and transportation. That is, separation, mixing, molding, printing, various transportation, etc. (***34 categories). Part C "Chemistry and Metallurgy" includes not only pure chemical contents such as inorganic compounds, polymer compounds and their preparation methods, but also products containing the above compounds, such as glass, ceramics, cement, fertilizers, plastics, coatings, petroleum industrial products and some products suitable for a certain purpose because of their special properties, such as explosives, dyes, adhesives, lubricants, detergents and other applied chemical parts. In addition, part c also includes some marginal industries, such as the manufacture of various fuels; Production and refining of oil and wax; Fermentation, microbial and genetic engineering, sugar industry, etc. And some purely mechanical or partial mechanical operations or treatments, such as leather and leather products treatment, water treatment or general anti-corrosion. Metallurgy, as a branch, is located in Part C, so this part also includes metallurgical, electrolytic and electrophoretic processes of various ferrous and nonferrous metals and alloys (*** 19 categories). Part D "Textile and Papermaking" includes textile, fiber, dyeing, cable, papermaking technology, etc. ((**8 categories). Part e "fixed buildings" (buildings, mining), including roads, railways, bridge buildings, water conservancy projects, water supply and drainage, housing construction, mining, etc. ((**7 categories). Part f "mechanical engineering" includes lighting, thermal engineering, weapons and explosions, as well as engines, pumps, general mechanical engineering, lighting, heating, weapons and blasting (*** 17 category). Part G "Physics" (instrument, nuclear physics), including testing, optics, photography, clocks and watches, control, calculation, education, musical instruments, nuclear physics, etc. (*** 13 category). Part H "Electric Power" includes electrical components and semiconductor technology, electric power, electronic circuits, telecommunication technology and others (***5 categories). In addition, the user's guide of the above eight parts is published separately as the ninth volume. It is the index of the major categories, minor categories and major groups in the eight major departments, and it is the guiding document of the international patent classification table. This paper explains the arrangement, classification and classification principles of the international patent classification table, which can help users to use the classification table correctly. The large group index includes more than 6,000 large group categories, and the large groups in 8 fascicles are incorporated into this fascicle. The layout of 3.3. IPC shows that we still cite the above category number "C07C 47/00" as an example. C07C 47/00 C chemistry, metallurgy C07 organic chemistry C07C acyclic and carbocyclic compounds C07C 47/00 compounds containing -CHO groups 47/02? 6? 1; Saturated compounds with -CHO groups attached to acyclic carbon or hydrogen atoms 47/04? 6? 1; ? 6? 1; Formaldehyde 47/042? 6? 1; ? 6? 1; ? 6? 1; Preparation from carbon monoxide [3] 47/052? 6? 1; ? 6? 1; ? 6? 1; Oxidation of methanol to prepare [3] 47/055? 6? 1; ? 6? 1; ? 6? 1; ? 6? 1; Using precious metals and their compounds as catalysts [3] 47/058? 6? 1; ? 6? 1; ? 6? 1; Separation; Purification; Stabilization; As can be seen from the example with addition [3] above, the classification number of international classification number can only judge the first four levels, that is, department, category, subcategory and group. As for the hierarchical relationship below the group, it is "? 6? 1; "00" is equivalent to level 5, a "? 6? 1; "means level six," 6? 1; ? 6? 1; "It means level 7"? 6? 1; ? 6? 1; ? 6? 1; "Represents level 8. The smallest international classification can be divided into 12, that is, there are 7 "? 6? 1; "。 The understanding of the meaning of category description should be considered by the upper and lower levels in series. For example, 47/042 and 47/052 both have three "? 6? 1; "47/042 is carbon monoxide to formaldehyde, and 47/052 is methanol oxidation to formaldehyde. There are four "47/055" 6? 1; "It belongs to 47/052 and has nothing to do with 47/042, because it is next to 47/052. So 47/055 means "using precious metals and their compounds as catalysts to prepare formaldehyde from methanol oxidation". Where there is a "[3]" symbol after a category, it means that the category has been revised in the third edition. 4. Notes on the Use of Part C-Chemistry and Metallurgy Although the class name of Part C is "Chemistry and Metallurgy", it does not summarize all the contents related to chemistry and chemical engineering, but divides a considerable part of the contents related to chemistry and chemical engineering into other departments. For example, some chemical processes, such as separation, dissolution and emulsification, as well as the processing of chemical instruments, equipment and plastic products, are divided into Part B "Operation and Transportation"; Chemical methods, photographic materials and processes used for analysis or testing belong to Part G "Physics"; In part D, the chemical processing of fabrics and the production of cellulose or paper are usually classified as "textiles and paper" ... the manufacture of batteries, etc. Included in Part H "Electricity". In addition, although pesticides, drugs, spices, cosmetics and other pure chemical parts. In part C, their applied chemistry is listed as "necessary for human life" in part A. For another example, the category of antioxidant components is in Part C, while the antioxidant used in food is in Part A, the categories of soil improvement components and soil stabilizer components are classified as Part C, and the substances related to filling soil pores are classified as Part E. The above categories related to chemical technology are scattered in other ministries, which is determined by the classification principles of functional categories and application categories set in the international patent classification table. When using the international patent classification table, we need to pay attention to its classification principles in order to choose the appropriate classification number accurately. In order to solve the problem of technical overlap, some additional rules are used in the international classification table, such as references, notes, priority rules, last position rules, first position rules, main composition rules and so on. (See the preface of the user guide for details). In the whole classification table, part C is the part that uses more additional rules. When determining the classification position of technical topics, we should also pay attention to the use of various additional rules. With the development of science and technology, the international patent classification table is constantly revised. Some technical topics were originally divided into one group. When the number of applications increases and subdivision can't solve the problem, a subcategory is set up. There are some categories that have been greatly adjusted. For example, in recent years, microbial technology has developed rapidly and been widely used. In the third edition, the category of C 12 has been greatly modified, and three subcategories of C 12B, C 12D and C 12K have been cancelled, and the contents of these three subcategories have been transferred to the newly established C 12M respectively. For another example, in the 4th edition, the original 1 1 group of subclasses C 10M was completely cancelled and reclassified. Second, the retrieval approach and examples Due to the above situation, it has brought certain difficulties to retrieval. Especially in the retrospective retrieval, we must pay attention to the corresponding relationship between the retrieval year and the version of the international patent classification table. For example, when we look up the literature of phosphor-containing and halogen-containing luminescent materials, there are three different classification numbers according to different years: C09K11/42; c09k 1 1/43； C09K 1 1/72. The classification number 1 is the second edition, which is suitable for searching the literature of 1974- 1979; The second classification number is the third edition, which is suitable for searching the literature of 1980- 1984; The last classification number is the fourth edition, which is suitable for searching documents after 1985. Therefore, when searching documents in different periods, we should pay attention to searching with different classification numbers. The biggest change of the fourth edition of the international patent classification table is the introduction of hybrid system in specific categories to improve the efficiency of the classification table. That is to say, in addition to the classification number, the additional information of non-mandatory classification is also represented by heuristic code or the combination of classification number and heuristic code. The fourth edition stipulates two kinds of additional information. The first kind of additional information refers to the valuable information described in detail in the invention specification; The second kind of additional information is the supplementary information of classified information. Hybrid system is used to represent the second kind of additional information. There are two kinds of heuristic codes for hybrid systems in the classification table. One is that the index code representation is separated from the classification table associated with it and becomes an independent small class or group. The leading code is expressed by replacing the slash (/) in the classification number with a colon (:). For example, C07K 99: 00. This lead code has C07K 99: 00 in part C; c 10N； C 12R. This category can only be used for introduction, not for classification. There is also a * * * that classifies and attracts both. The same category can be used for both classification and reference. These categories are explained at the beginning of the classification table. There are two ways to express the code cited in patent literature. One is the combined reference code, that is, the reference code is combined with the classification number associated with it in brackets. The classification numbers of technical topics are listed in brackets first, and then the reference codes are listed. Each group of combined lead codes is represented by separate brackets. For example: (C08F210/16,214: 06), (C08F255/04,214: 06). There is also a kind of lead code that is not used together, that is, the lead code appears alone, and it does not need to indicate which classification numbers the lead code is associated with. For example: B29K9: 00. The purpose of using citation coding is to improve the detection rate and retrieval accuracy. When there are too many patent documents under the same classification number, it is not conducive to retrieval, so it is necessary to subdivide them. However, due to the development of science and technology and the intersection of disciplines, from a single point of view, it is sometimes impossible to subdivide, or although it can be subdivided, it is of little significance. In this case, it is more effective to use quotation marks to retrieve interdisciplinary topics. 5. Steps of selecting IPC number and its auxiliary reference books For beginners, it is quite difficult to directly read the eight parts of IPC table (that is, eight volumes) to select the relevant IPC number because they are not familiar with IPC system. This is often like looking for a needle in a haystack, in vain. So they'd better take the following two shortcuts: (1) Start with keyword index. The official buzzword index is an entry tool for finding IPC. It is a thesaurus index, printed separately with 8 IPC tables. The keywords in the index are arranged in alphabetical order, and there are subdivided subordinate keywords under the keywords, which can be called modifiers or qualifiers, mostly expressed in the form of phrases, and then IPC numbers are listed. For example, if we want to find the patent literature on the subject of "preparation of epoxy resin", we can choose the word "epoxy" as the key word. Look up the keyword index to get: epoxy-low molecular compound c07d 30 1/00 weight 303/00 polycondensate containing-group C08G59/ 00 cyclic ether polymerized C08G 65/02 According to the IPC number found above, divide the volume by C, turn to each category number in turn, and further select the more relevant classification number listed below each category number. If you want to find the literature of ethylene oxide, you can choose the first category number C07D301/00 according to the content; To find the literature of epoxy resin, you can choose the third category number C08G 59/00, then use C to find out these two category numbers, and then further select the more relevant fine classification numbers listed below them. Therefore, starting with the keyword index, the blindness of random search of eight volumes can be greatly reduced. (2) Starting from the user's guide, this is an index arranged according to the first three categories of IPC. Searching the classification number through the user guide is based on the nature of the topic. First, determine the broad category, that is, start from the "broad category directory" in the user's guide, extradite the large category number given in the "broad category directory" to the "small category directory", and extradite it to the "large group directory" to find the large group according to the small category number given in the "small category directory".