Classification of layered products is provided for in many technical areas, most of which are confined to a particular kind of material. However, in order that this subclass may provide a basis for making a complete search with respect to layered products, any layered product that specifies relevant useful information is classified in this subclass even though it may also be classified in other classes.

Classification in other areas should be made in the following situations:

Classification guidance:

Allocation of Indexing symbols:

The following Orthogonal Indexing Symbols are mandatory in this subclass:

Breakdown Indexing symbols, e.g. B32B 2037/0061 or B32B 2038/0016, are used for additional classification in B32B 37/00 – B32B 43/00.

In this subclass, C-Sets classification is applied to the following groups, listed in the table below, if the document discloses a pertinent combination of technical features that cannot be covered by the allocation of a single symbol. The fourth column of the table indicates the place where the detailed information about the C-Sets construction and the associated syntax rules can be found, in the definition section "Special rules of classification".

The specific C-Sets rule is located at only one place of the base symbol in the section "Special rules of classification" in the definition. If the C-Sets rule is applicable to all groups of a subclass, it is located at the subclass level only. If the same C-Sets rule is applicable to multiple groups or subgroups within the same subclass, the C-Sets rule is placed at the highest group or subgroup of the multiple groups.

The layer has to have one of the forms defined hereunder:

Preformed layer, i.e. taking the form of a layer at some stage before being brought into combination with another layer. Preformed layers include:

Layers formed in-situ, i.e. taking the form of a layer while or after being brought into combination with another layer. Layers formed in-situ include:

Layered products having a non-planar shape, such as an article having a shape that defines an internal cavity, e.g. a container, or in the form of a tubular product.

Illustrative example of subject matter classified in this place:

A planar layered product having a cavity or internal void formed within a single layer should be placed in B32B 3/26 or its subgroups and not in B32B 1/00.

For classification of a product in this group, surface unevenness, surface non-uniformity and the shape of individual layers are ignored.

Layered products in the shape of a container or receptacle are also classified in B32B 2439/00 – B32B 2439/80.

Layered products characterised by a hollow structure with an elongated length, e.g. a hose, pipe or sleeve, wherein the hollow structure may, or may not, be closed at one end.

Illustrative examples of subject matter classified in this place:

1.

2.

Layered products in the shape of a tube, hose, pipe or sleeve are also classified in B32B 2597/00.

Features of form of any of the individual layers of a layered product. Examples include:

B32B 1/00 – B32B 1/08 cover layered products where all the layers cooperate to define a non-planar shape, whereas B32B 3/00 – B32B 3/30 cover features related to the shape of individual layers in planar or non-planar layered products.

The following physical structure of an individual layer does not constitute a feature of form that is proper for this main group:

However, if a layered product has a fibrous, filamentary, foamed or particulate layer having a feature of form proper for this main group, it should also be classified in this main group. For example, a layered product having a non-woven fibrous layer with apertures in the layer would be proper for B32B 3/266 and B32B 5/022.

Layered products having a layer of regularly-arranged cells shall be placed in B32B 3/12 regardless of whether the layer was formed from one piece or separate pieces of material juxtaposed side-by-side.

Layered products having a layer with a feature of form that differs physically in different parts of the layer are provided for in both B32B 3/00 – B32B 3/30 and B32B 5/14 – B32B 5/147. For example, a layer having a density variation in apertures across its surface area would be provided for in B32B 3/266 and B32B 5/142.

Illustrative example of subject matter classified in this group:

Layered products comprising honeycombs and similar layers of cells having a regular, repeating, geometric structure.

Layered products comprising a face layer formed by elements, e.g. tiles, strips, rods, bricks and other elements, which are juxtaposed side-by-side, e.g. mosaics. The elements are laid out in a specific manner rather than merely agglomerated or scattered and are larger than mere particles.

Layered products comprising an internal layer formed by elements, e.g. tiles, strips, rods, bricks and other elements, which are juxtaposed side-by-side, e.g. mosaics. The elements are laid out in a specific manner rather than merely agglomerated or scattered and are larger than mere particles.

Layered products comprising a layer having changes of thickness which are not of a minor and accidental nature, or a mere, non intended result of a surface structure, e.g. grooves, ribs or protuberances.

Layered products comprising at least one layer that is a fibrous, filamentary, particulate or foamed layer (see definitions in B32B subclass glossary). A layered product can include:

Layered products characterised by a layer differing constitutionally or physically in different parts, e.g. a synthetic resin layer that has greater crosslinking near its faces; a cementitious layer with different density from core to outer faces.

In classifying a layered product comprising a fibrous, filamentary, foamed or particulate layer, each layer in the layered product is classified in the appropriate subgroup for that specific layer based on material, adjacency and/or structure. The fibrous, filamentary, foamed or particulate layer(s) is classified in B32B 5/00 and the layer(s) of other materials are classified in other B32B subgroups as appropriate for the specific layer. Several classification symbols can be given.

Example:

Layers in which the fibres, filaments or particles are present as additives or filler material are classified in the appropriate material subgroup of the matrix material, e.g. B32B 25/02.

Classification in other areas of B32B should be made in the following situations:

Layered products comprising a fibrous or filamentary layer, e.g. woven; non-woven; knit; nets produced from fibres, filaments, yarns, threads; ribbons or tapes; or a layer formed by regularly laid parallel cords or filaments, which may be bunched, flat or slightly separated, e.g. juxtaposed-side-by-side.

Classification of fibrous and filamentary layered products is provided for in many technical areas of CPC depending on the structure of the fabric or textile layers, yarns, fibres or filaments. However, in order that this subgroup may provide a basis for making a complete search with respect to fibrous or filamentary layered products, any layered product that specifies relevant useful information is classified in this subgroup even though it may also be classified in other Subclasses. Several classifications symbols can be given.

Classification in other areas should be made in the following situations:

Layered products characterised by a particular arrangement of the fibres or filaments of the layers, e.g. fibres or filaments of the different layers being parallel or perpendicular to each other. The layers may be next to each other or separated by other layers.

In-situ foams include a foamable layer that is assembled or installed and then foamed in or within the laminate or installation, e.g. a foamable polymer layer between two exterior layers, wherein the polymer layer is converted to foam after assembly between the exterior layers. The foamable layer can be preformed or can take the form of a layer while or after being brought into combination with another layer, e.g. casting, extrusion or molding of a melt material.

Layered products characterised by the adjacency of more than one fibrous or filamentary layers, i.e. woven, non-woven, knit or net layers, which are adjacent at least one or more woven, non-woven, knit or net layers. For example, a woven layer adjacent a non-woven layer; a knit layer adjacent a non-woven layer; a woven layer adjacent one or more non-woven layers.

Classification in subgroups B32B 5/26-B32B 5/2795 is determined by the subgroup with the most specific subject matter. Classification in B32B 5/26-B32B 5/2795 is only required in the subgroup with the lowest level of indentation.

Layered products wherein all layers are fibrous or filamentary layers are also classified in B32B 2250/20.

Layered products wherein two or more fibrous or filamentary layers are impregnated are classified in B32B 2260/023.

Layered products with conjugate and/or mixed fibres or filaments associated with a fibrous or filamentary layer, i.e. woven, non-woven, knit or netting, are classified in B32B 2262/12-B32B 2262/156.

Layered products wherein all layers are foamed layers are also classified in B32B 2250/22.

This group covers layered products in which the relationship between the layers is important. The relationship could be, for example, the differences between physical or chemical properties, patterns of connection, and the orientations of features.

This group covers layered products characterised by having two or more layers, one of which differs from another with respect to a physical property, e.g. density, melting point, refractive index. Examples of this type of product are those comprising layers of:

This group covers layered products characterised by having two or more layers, one of which differs from another with respect to the orientation of features, e.g. the direction of one layer's corrugation or joints differs from that of another layer. The layers may be next to each other or separated by other layers.

If there is only one corrugated layer in a layered product, it is classified in B32B 3/28 or B32B 29/08.

This group covers layered products in which a pair of interconnected layers is bonded by one or both layers having inter-reactive properties, wherein neither layer of the interconnected pair comprises an adhesive – whether a coated adhesive, a tie layer, or a layer described as acting as an adhesive.

This group covers layered products comprising an adhesive – whether a coated adhesive, a tie layer or a layer described as acting as an adhesive – inserted between two layers to bond them.

Layered products characterised by having a continuous or discontinuous metal layer.

Coating on a metallic layer is classified with an appropriate Indexing symbol in B32B 2255/00

Layered products with all layers being metallic in the form of sheets/plates, distinct layers. They can be made by any possible method such as roll bonding, cladding, brazing, coating etc.

If the layered product comprises a layer that is not metallic such as polymer, ceramic, glass etc. then it is not classified in B32B 15/01- B32B 15/018, but in other parts of B32B.

Layered products comprising:

In the case that a layered product comprises a layer of glass fibres without any layer of sheet glass, classification is done in B32B 5/02, the presence of glass fibres being classified by the indexing symbol B32B 2262/101.

B32B 17/00 requires that the layered product comprises at least one glass layer and at least one layer of another material; a layered product comprising both a glass layer and a glass fibre layer is classified in both B32B 17/02 (or B32B 17/04) and B32B 17/06.

Layered products comprising an inorganic glass layer in sheet or film form next to another layer of generic material.

The layers need not be permanently secured, such as a releasable protective layer.

Various materials are used in combination with sheets of glass for the enhancement of the properties of one of the layer, for instance, for protection or reinforcement of natural stone, for architectural purposes in general (E06B 3/54 or E04F 13/14), or for displays in a variety of devices.

B32B 17/06 is given in the case that an inorganic glass layer is present next to another glass layer with no further information.

Layered products comprising inorganic glass in sheet or film form next to a layer of a cellulose derivative or gelatin as polymeric substance.

Layered products comprising at least one inorganic glass layer in sheet or film form next to a layer of synthetic resin; the synthetic resin layer can be used as a glue layer to bond the glass layer with another glass layer or another material layer or can be used as a removable protective film.

In this group, a layer of organic glass is not considered as a glass layer but as a synthetic resin layer. The nature of the synthetic resin material is classified using the appropriate orthogonal symbols from groups B32B 2319/00 - B32B 2386/00 as a single symbol(s).

Layered products comprising at least one inorganic glass layer in sheet form next to a layer of synthetic resin; wherein the glass sheet is permanently bonded to at least one further glass layer in sheet form or a durable polymeric sheet or film via the layer of synthetic resin as a resin interlayer, and wherein the interlayer keeps the laminated safety glass or glazing bonded even when struck or broken, preventing the glass from shattering.

Laminated safety glass or glazing is used for automotive and transport applications (automotive windows in general B60J 1/00), for architectural purposes (E06B 3/54 or E04F 13/15), transparent armour (F41H 5/0407), head-up displays (G02B 27/01) and photovoltaic modules (H01L 31/048).

Laminated safety glass comprising at least one layer of inorganic glass, a resin interlayer and an external layer of a synthetic polymeric sheet or film is classified using the appropriate group selected from B32B 17/10009 - B32B 17/1099 together with the B32B 2319/00 - B32B 2386/00 orthogonal Indexing symbol that designates the polymeric material of said external polymer layer as a single symbol.

The presence of resin interlayers, their properties and/or their compositions are further specified in groups B32B 17/1055 - B32B 17/10798.

The resin interlayer or all components of a composite interlayer are to be considered a layer proper for B32B and can be made by any process, including a coating process.

If relevant, an allocation in B32B 2250/02 - B32B 2250/05 may be applied to classify the total number of layers in the composite interlayer, i.e. the total number of interlayers, intermediate layers and functional layers. For example, the laminated glazing shown in the figure of the third C-set example would be proper for B32B 2250/03, which covers three layers, not B32B 2250/05, which covers five layers, because of the three layers of the composite interlayer.

A laminated safety glass or glazing to be used in a head-up display should be classified in B32B 2457/20 and not B32B 2551/00.

If relevant, particles that are present in the glass layers, the durable polymer sheet, the intermediate layers and/or the resin interlayers can be classified in B32B 2264/00-B32B 2264/504.

A laminated safety glass or glazing proper for B32B 17/10009 - B32B 17/1099 should not be separately classified in B32B 27/00 - B32B 27/42. Additional classification in B32B 27/00 - B32B 27/42 is only required when the laminated safety glass or glazing has (1) a further polymeric layer externally attached to the laminated safety glass or glazing; or (2) the composite interlayer is disclosed for separate use not in the form of a laminated safety glass or glazing.

If relevant, classification in B32B 37/00 - B32B 43/006 may be allocated in addition to B32B 17/10807 - B32B 17/1099 in order to capture invention information for the lamination process or apparatus that are not specifically provided for in the B32B 17/10807 - B32B 17/1099 subgroups.

If groups in B32B 37/00 - B32B 43/006 are to be allocated, the materials of the inorganic glass layer, interlayer or composite interlayer should not be separately classified as a single orthogonal indexing symbol. For example, the laminated glazing shown in the figure of the third C-set example should not have a single symbol allocated in B32B 2315/08, B32B 2367/00 or B32B 2375/00.

Classification is applied as Invention (I) information for the subgroups corresponding to the materials indicated in the examples and disclosed as Inventive. In the absence of examples, the pertinent more general main groups or subgroups are allocated.

When B32B 17/10005 is used as a base symbol in C-Sets, it is not allocated as a separate single symbol.

At least two pre-shaped green ceramic, ceramic pre-form (e.g. a ceramic fiber pre-form) or sintered ceramic layers are joined together, where the emphasis is not on the joining method. It also encompasses two layers of ceramic powders that are pressed together in a press. If after joining the two ceramic layers other type of layers, e.g. metallic or plastic layers are joined to the initial ceramic laminate, classification under other main groups of B32B will be necessary as well, but classification in B32B 18/00 remains. If in between the two ceramic layers there is a thin, non-essential layer of another material, e.g. a metallic electrode, it is still classified in B32B 18/00, but classification in other groups of B32B should be considered. B32B 18/00 is normally not used for laminates containing identical ceramic layers, such as in multilayer capacitors.

B32B 18/00 also contains cold bonding of ceramic substrates.

Under C04B 37/00 the emphasis is on how the articles are joined. If two ceramic layers are joined, but the emphasis is not on how they are joined, classification would be in B32B 18/00.

Secondary aspects of making ceramic laminates (B32B 18/00) and of joining ceramic articles with other articles through heating (C04B 37/00) are classified with Indexing Code C04B 2237/00, e.g. the composition of the layers or articles that are laminated or joined.

Aspects regarding the heat treatments that are used for laminating are classified in C04B 35/64 and with Indexing Code C04B 2235/65, where the heat treatment of the laminating step should be considered as a sintering step. If for instance pressure is exerted during heating to laminate the articles, C04B 35/645 should be given. Aspects regarding the atmosphere of the heating step, possible annealing steps, heating rate, cooling rate, etc. are given Indexing Code C04B 2235/65.

If much detail regarding the composition and/or synthesis of one or more ceramic layers or articles is given, classification in C04B 35/00 should be considered.

Electrode and electrodes layers that are inserted between ceramic substrate layers are normally not seen as interlayers, since they normally do not have the function of joining the two ceramic substrates. They therefore do not receive a C04B 2237/12 Indexing Code. Only if it is clear that the electrode does have a joining effect, would it be regarded as an interlayer, and an Indexing Code under C04B 2237/12 would be allocated. In that case C04B 37/006 has to be used and there is no classification in B32B 18/00.

Layered products characterised by having a layer made of naturally occurring mineral fibres or particles.

Product features classified in this group are also classified in B32B 5/00.

Layered products characterised by a layer of thermosetting synthetic rubber.

Layered products characterised by a layer of a synthetic resin other than a cellulosic plastic resin or a thermosetting synthetic rubber.

Illustrative example of subject matter classified in this group:

Layered products wherein all layers are made of polymers belonging to B32B 27/30 and B32B 27/32 are classified in B32B 2250/246.

Layered products wherein all layers are made of polymers belonging to B32B 27/36 are classified in B32B 2250/244.

Properties should as far as possible be classified in B32B 2307/00

Making products characterised by particular features of structure or of composition, see the relevant groups for such products, e.g. B32B 1/00, B32B 9/00.

Coextrusion steps are classified in B32B 37/153 or B32B 37/156 as long as the coextruded layers are joined with at least one additional layer.

Coating steps are classified in B32B 2037/243 as long as the coated layers are joined with at least one additional layer.

Particular aspects directed to removing the carrier layers are classified in B32B 38/10.

Operations implemented on layered products not in connection with the lamination process are classified in B32B 43/00 or in fields related to said operations.

Laminate treatment is additionally classified in groups B32B 2310/00 - B32B 2310/14.

The layout of stations in a manufacturing line.

Inorganic particles in compositions which form a particulate layer or being present as additives.