CN1187787A - Multilayer film structures for use in production of banknotes or like - Google Patents

Abstract

A laminate multilayer film substrate for use in the production of banknotes including a first layer and a second layer, which may be the same or different, each comprising at least 50 weight percent of a high density polyethylene having a density of at least 0.94 g/cc and each being oriented in at least a first direction to a degree which is at least three times greater than the degree of orientation present in a second direction substantially normal to the first direction wherein the second layer is laminated to the first layer so that the first direction of orientation of the second layer is substantially aligned with the first direction of orientation of the first layer.

Description

Used composite wafer structure in the production of banknote or similar products

The present invention relates to such as used composite wafer in the production of banknote or this class paperlike products of false proof document such as traveler's check, banker's check, and the production method of these products.More particularly, the present invention relates to a kind of structure of composite wafer of lamination, it has many features that normally used high-quality paper product is presented in the production of banknote and false proof document.

In the production of banknote and false proof document, using has had the history in more than 300 year as the good quality paper of raw material with rag.As well-known, be that the good quality paper of raw material has some very Ideal Characteristics in these application scenarios with the rag, comprising: can fold dead pleat, anti-tear pulling, impressionability, and can protruding seal.

Very its feature of Ideal Characteristics is as follows for these: be meant that thin slice has fold or folding ability but can fold dead pleat, and keep not amounting to and can opening voluntarily; Anti-tear pulling is meant that thin slice has the ability of having a mind to and tear and bore a hole unintentionally of resisting; Impressionability is meant that thin slice has the ability of adsorbing and being bonding to printing ink used in the typographical printing process; Can be meant that thin slice has deformation ability under the pressure of gravure printing technique by protruding seal, so that on final banknote or false proof document, form the pattern of projection, and base gravure ink is retained in strained boss, thereby makes banknote or false proof document possess the tactile feel or the distinguishing of height.The combination that is appreciated that all these characteristics has been given the common function of article such as banknote and to their perceptual knowledge.

Along with the appearance of color photocopying and computer picture scanner, the forgery of banknote increases significantly.Although most of coin paper manufacturer is carrying out effective effort, usually use watermark, wire, optical change characteristic body (light-sensitive material for example, hologram or diffraction grating) wait their substrate is insured more, however these effort do not demonstrate very big hope for defeating the adulterator.

If transparent " window " is set in banknote, the plasticity substrate just can provide an important anti-counterfeiting characteristic, and this window can guarantee that scanner or color copy machine can't duplicate banknote.In addition, can also comprise down the mark of seal in conjunction with other protection feature in banknote or on the banknote, to protect anti-counterfeiting characteristic and to guarantee to print errorless.

According to the present invention, provide a kind of multi-layer thin substrate of used in the production of banknote, false proof document, anti-lamination that curl, the cross section symmetry, it comprises:

(a) ground floor with inboard and outside, it comprises the high density polyethylene (HDPE) of at least 50% weight ratio, this density is at least 0.94, described ground floor is big at least three times along the extension degree of a second direction along the extension degree ratio of at least one first direction, and this second direction is substantially perpendicular to first direction;

(b) second layer with inboard and outside, it comprises the high density polyethylene (HDPE) of at least 50% weight ratio, this density is at least 0.94, the described second layer is big at least three times along the extension degree of second direction along the extension degree ratio of at least one first direction, and this second direction is substantially perpendicular to first direction; And

(c) a lamination adhering resin between the inboard separately at the ground floor (a) and the second layer (b), it comprises a kind of composition of selecting from one group of material that low density polyethylene (LDPE) (LDPE) and LLDPE (LLDPE) are formed; The described second layer is laminated on the described ground floor, and the first direction of the described second layer and the first direction of described ground floor are arranged in a straight line substantially.

In another embodiment, the present invention relates to the preparation method of a banknote, this method comprises:

(i) use a lamination adhering resin, this resin comprises a kind of composition of selecting from one group of material that low density polyethylene (LDPE) (LDPE) and LLDPE (LLDPE) are formed; Ground floor (a) with inboard and outside is laminated on the second layer (b) with inboard and outside, and this ground floor comprises the high density polyethylene (HDPE) of at least 50% weight ratio, and this density is at least 0.94g/cc; Described ground floor is big at least three times along the extension degree of machine direction (MD) along the extension degree ratio of horizontal (TD), this second layer comprises the high density polyethylene (HDPE) of at least 50% weight ratio, this density is at least 0.94, the described second layer is big at least three times along the extension degree of machine direction along horizontal extension degree ratio, the described second layer is laminated on the thin substrate, and the described of the described second layer laterally laterally is arranged in a straight line substantially with the described of described ground floor, with this form can protruding seal substrate; And

(ii) described substrate is carried out protruding seal.

The thin slice of Chan Shenging presents good dead pleat characteristic and other characteristic like this, a symmetrical structure for example, even this just provides at high temperature, for example 66 ℃ (150) also unconvoluted thin slices make these thin slices be very suitable for the production of banknote and other false proof document.

In another embodiment, the present invention relates to by can multi-layer thin substrate protruding seal, lamination the made false proof valency certificate that has, for example banknote or stock, described substrate comprises:

(a) ground floor with inboard and outside, it comprises the high density polyethylene (HDPE) of at least 50% weight ratio, and this density is at least 0.94, and described ground floor compares big at least three times along the extension degree of machine direction (MD) along the horizontal extension degree of (TD); And

(b) second layer with inboard and outside, it comprises the high density polyethylene (HDPE) of at least 50% weight ratio, and this density is at least 0.94, and the described second layer compares big at least three times along the extension degree of machine direction along horizontal extension degree; The described second layer is laminated on the described ground floor, and make the second layer laterally and laterally being arranged in a straight line substantially of ground floor.

In yet another embodiment, the present invention relates to manufacture method used, that prevent the thin substrate of laminated multilayer curling and protruding seal in the production of article such as banknote, false proof document, this method comprises:

(i) on the both sides of high density oriented polyethylene layer, provide a polypropylene copolymer top layer with inboard and outside, the directed extension of described high density polyethylene layer comprises the high density polyethylene (HDPE) of at least 50% weight ratio, its density is at least 0.94, and described polyethylene layer is big at least three times along the extension degree of machine direction (MD) along the extension degree ratio of horizontal (TD);

(ii) on the polypropylene copolymer top layer of a side of described polyethylene layer, apply one and help sticking priming coat, thereby prepare the ground floor (a) of coating with a coated side;

(iii) weight step (i) and (ii) is to prepare the second layer (b) with coating of coated side;

One anti-counterfeiting characteristic thing independently (iv) is set on the coated side of the one deck in described coat;

(v) between described coating two-layer, the lamination adhering resin of an orientable extension is set and the two-layer of described coating is laminated together, select the bearing of trend of described lamination adhering resin simultaneously, so that basic one transparent laminated foil to be provided;

(vi) around described anti-counterfeiting characteristic thing, on at least one side of the described laminated foil of substantially transparent, carry out intaglio printing with opaque ink, thereby provide a transparent window around described anti-counterfeiting characteristic thing, make from least one side of described thin substrate, preferably this anti-counterfeiting characteristic thing can be seen in both sides.

In the making of the multi-layer thin substrate that is used for producing banknote and other false proof document of the present invention, the two-layer at least of substrate is Main Ingredients and Appearance with high density polyethylene (HDPE) (HDPE) all, and this density is at least 0.94, preferably is at least 0.945.These thin layers can be made of single high-density polyethylene resin, it also can be the mixture of several high-density polyethylene resins, perhaps constituted, for example contained low density polyethylene (LDPE) (LDPE), LLDPE (LLDPE), polypropylene, ethylene-vinyl alcohol (EVOH) copolymer, ethylene, propylene (EP) copolymer or ethylene-propylene-butene-1 (EPB) copolymer of a small amount of composition by the high density polyethylene (HDPE) that contains a small amount of other polymeric material of composition.Although in an embodiment of the present invention, the high-density polyethylene resin of single variety or the mixture of several high-density polyethylene resins are adopted in special recommendation, but above-mentioned the third situation also is feasible. in these high-density polyethylene resins of recommending, can add processing additive, microwax etc. for example is so that improve the service behaviour of extruder by the moment of torsion that reduces extruder.Have found that the thin slice of being made after adopting the mixture of several high density polyethylene (HDPE)s or adding microwax has all reduced its wear resistant, this show thin slice transversely (TD) be easy to tear.

When adopting the mixture of several high density polyethylene (HDPE)s, these mixtures can comprise two or more polymer, and all polymer preferably all have 0.94 or higher density.The mixture of high density polyethylene polyethylene polymers preferably contain a kind of melt index be 0.6～1.2 high density polyethylene (HDPE) as Main Ingredients and Appearance, contain the copolymer of one or more different melt index again.

Triple mixtures also may be that desirable, suitable triple mixtures generally include: 50%～98%, and the high density polyethylene (HDPE) of 84%～96% weight ratio preferably, its density is 0.96 or higher, melt index is greater than 0.5～2.0; 1%～25%, the high density polyethylene (HDPE) of 3%～8% weight ratio preferably, its density is 0.94 or higher, melt index is 0.1～0.5; And 1%～25%, the high density polyethylene (HDPE) of 3%～8% weight ratio preferably, its density is 0.96 or higher, melt index is greater than 2～8.Wherein, preferably quantity is equal for second less and the third high density polyethylene polyethylene polymers of composition.

As most preferred embodiment, thin substrate of the present invention comprises: (a) ground floor, it comprises the high density polyethylene (HDPE) of at least 50% weight ratio, this density is at least 0.94, this ground floor is along at least one first direction, promptly laterally the orientation extension degree of (TD) is substantially perpendicular to this first direction than the edge, and promptly the orientation of machine direction (MD) extension degree is big at least three times; (b) second layer, it also comprises the high density polyethylene (HDPE) of at least 50% weight ratio, this density is at least 0.95, this second layer is along at least one first direction, promptly laterally the orientation of (TD) extension degree also is substantially perpendicular to this first direction than the edge, and promptly the orientation of machine direction (MD) extension degree is big at least three times; The second layer is laminated on the thin substrate, makes the first direction and the first direction of ground floor substantially parallel mutually (promptly being arranged in a straight line) of the second layer.The method of being produced the high density polyethylene (HDPE) thin slice by the unequal directed extension method of twin shaft has been disclosed in U.S. Pat 4,870, in 122.

Such just as will be understood, wear resistant for the composite wafer that can improve type described here, have found that, the unequal directed high density polyethylene (HDPE) thin slice that extends of twin shaft is laminated together, their directed principal direction of extending is parallel to each other basically, simultaneously with a directed laminated resin that extends, LLDPE (LLDPE) for example, be arranged on two-layer between, and make directed principal direction of extending resin be basically perpendicular to the principal direction of the first and second high density polyethylene (HDPE) thin slices, so just can improve wear resistant.In one embodiment, this vertical orientation of the principal direction of lamination adhering resin is finished in lamination step own, and preferably finish along machine direction (MD).

The orientation extension degree of high density polyethylene (HDPE) thin layer is an important directions of the present invention, and this is because suitable orientation extension degree provides desirable physical characteristic.Although by the curtain coating extrusion molding, density be 0.957 or higher high-density polyethylene resin can directly laminate, exist curl, the problem of aspects such as uniformity and grazing.Therefore, the high density polyethylene (HDPE) thin slice that 0.02～0.04mm that various aspects of performance is the most balanced is thick is to be made by the unequal directed thin slice that extends of twin shaft, the latter is to be that (12～20mils) web preparation, it is reduced to desired thickness by promptly directed extension that stretch to 0.3～0.5mm by casting out thickness.

Thin slice is produced and directed the extension in a conventional manner.Thin slice is heated to its directed temperature of extending, and in the orientation calendering of at first carrying out between two groups of knobbling rolls on the machine direction (MD).The rotating speed of second group of roller is greater than the rotating speed of first group of roller, and its increment equals desired calendering ratio.Then, by heating and on a stenter, making the thin slice cross directional stretch, make thin slice in laterally (TD) upward directed extension.Usually, it is to carry out under 60 ℃～120 ℃ temperature that the orientation on the machine direction (MD) is extended, and laterally the orientation extension on (TD) is to carry out under 110 ℃～145 ℃ temperature.

Although the mode of Tui Jianing is here: thin slice is bigger at least three times perpendicular to the orientation extension degree of the second direction of this first direction than the edge along the orientation extension degree of a first direction, yet more desirable mode is: each high density polyethylene (HDPE) thin slice extends 1.1～2.0 times along machine direction (MD) is directed, extends 6～12 times along laterally (TD) direction is directed.Have found that, when casting machine speed height to 110 feet per minute, during promptly corresponding to the linear velocity of 140 feet per minutes, and when extending 1.25 times, just can produce the outstanding high density polyethylene (HDPE) thin slice of quality along machine direction (MD) is directed.

When using, the unequal orientation of this degree extends on the high-density polyethylene olefinic constituent in the structure and produces interesting phenomenon, visible ripple and lines promptly occur, and these parallel corrugations are in horizontal direction.Under low power amplification situation, will see ripple and the lines that 5～30 discontinuous fluctuatings are arranged on the high density polyethylene (HDPE) thin slice of each square centimeter, they are parallel to directed bearing of trend usually.This phenomenon makes thin slice, and some is translucent a little, thereby when passing thin slice and observe, and some is fuzzy a little to make the object in a distant place.This phenomenon shows that each layer all extends so that unequal mode is directed.Implement when of the present invention used high density polyethylene (HDPE) and also comprise and be disclosed in U.S. Pat 4,870, those contents in 122.

In order to reach the desired desirable surface characteristic of paperlike products of the present invention, can on the high density polyethylene (HDPE) substrate material of multilayer, one or several top layer be set, this can be undertaken by any known mode, for example applying or extruding simultaneously before orientation is extended, also can be to carry out the high density polyethylene (HDPE) coating after extending operations in that one or two are directed.The top layer can be any be used for a certain purpose and and the traditional material that combines of polyolefine sheet, particularly polyethylene sheets, for example: easily press the surface in order to obtain one, if necessary, polymer resin can be mixed with filler, fiber, pigment etc.In addition, as U.S. Pat 4,377, the disclosed thin slices that contain the space such as 616,4,632,869,4,758,462 also can be laminated on the high density polyethylene (HDPE) substrate of multilayer, so that give thin slice of the present invention with their various characteristics.

Aforesaid containing (a) and (b) two-layer high density polyethylene (HDPE) thin slice also can further comprise the top layer of polypropylene copolymer, ethylene-propylene-butene-1 terpolymers for example, it is set at least one side of thin slice, preferably is located on the inboard and the outside of thin slice.In a most preferred embodiment, top layer itself can comprise a kind of composition, and this composition is identical with the composition that is used in laminate layers (a) and the adhering resin that (b) sticks together.For example, in a most preferred embodiment, 10%～20% all the other compositions that low density polyethylene (LDPE) (LDPE) can account for the top layer weight ratio are polypropylene copolymers.

A kind of at laminating surface, promptly provide suitable the helping of bigger bonding force to glue the optional one group of material forming from polymine, epoxy resin, polyurethane and acrylic resin of priming coat between the copolymer surface.This helps sticking priming coat can be coated between polypropylene copolymer top layer (being positioned on polyethylene layer (a) and the inboard (b)) and the lamination bonding agent.The composition of priming coat is disclosed in U.S. Pat 4,447, in 494 and 4,681,803.

Can expect, before or after lamination, can carry out protruding seal, painted, printing, veining or other processing to substrate, these can carry out on the inner face of laminated foil or outside, so that for example provide about aspects such as banknote kind, validity or face amounts, resolution characteristic vision or sense of touch.

Be used for implementing lamination of the present invention and be the known technology in this area, it comprises: bonding or glued joint, promptly use the lamination adhering resin, and preferably use transparent adhesive to connect; Welding is sprayed at one deck solvent on interconnective two surfaces of desire; Hot joining, thermoplastic thin slice wherein is subjected to hot rolling or heat pressing operation; Casting connects, and ground floor wherein is cast on the second layer, and the second layer constitutes a substrate; And the extruding or draw lamination, roll operation as known in the art.

When some anti-counterfeiting characteristic things independently, when for example optical change characteristic body (OVDs) was attached in the substrate, these characteristic bodies can be closed in some boxes that are fixed in substrate.But then, optical change characteristic body itself also can be directly combines with one deck (or two-layer) in the laminated substrate, perhaps between two-layer, thereby do not need independent feature thing on the physical significance is contained in the box of the clearly definition between two-layer.

The present invention can adopt any suitable anti-counterfeiting characteristic thing, for example is selected from following this stack features thing: optical change characteristic body (OVDs), magnetic characteristic thing, electronic characteristic thing, and the characteristic body that contains rare underground element.Wherein the optical change characteristic body is first-selected.

Term " optical change " used in this specification is meant any such characteristic body, and promptly they can be made into reversible, foreseeable repeatably mode and change its outward appearance.For example, change by applying human heat or finger pressure, visual angle and the change of brightness conditions when observing, the outward appearance of these characteristic bodies just can change.The type of foreseeable these characteristic bodies of the present invention has: diffraction grating; Liquid crystal; By ripple image or the similar image that the cross grating produces, biconvex lens and transparent grid, for example grid of Fresnel lens that it is superimposed with or does not superpose and reflect; The isolated coating that produces the interference figure or the similar pattern of variation of local reflex and local transmission; Birefringence or ambipolar layer or zone plate.

Usually, the characteristic body of the optical effect of this character is easy to be discerned by the ordinary people, and is difficult to so far be duplicated by photograph and printing technology.And, produce the characteristic body of any this class in the mode of duplication of production, and it is attached in the plasticity laminated foil described in the invention, as if this exceeded most of potential adulterators' limit of power.Even need the product of soft paper shape, for example banknote is so certain, and these optical change characteristic bodies himself also should be sheets, softness and thin.These characteristic bodies are preferably compatible mutually with the used plastic material of laminated foil, are beneficial to combination and slow down the changes of reactivity that takes place along with the time.

According to the present invention, a recommendation form of optical change characteristic body is the diffraction grating of reflection, and it comprises that a spraying plating is with the protruding seal diffraction pattern of the thermoplastic thin slice of metal.In order to prevent to touch the pattern of protruding seal for illegal purpose of duplicating, according to the present invention, layer of thermoplastic material is all adopted in the both sides that are preferably in metallized thin slice, and it has the dissolution characteristics identical with metal level, like this, etch separation commonly used just is very difficult to carry out.The characteristic body form of another recommendation is by repeating the take a picture fine rule of generation or the wave pattern that point is formed on the both sides of a thin slice.The mutual distance of Points And lines can be made very for a short time, so that be difficult to be duplicated by printing technology, the ripple image then can demonstrate very big size.Unique diffraction pattern or ripple image are often preferentially used on banknote, also can be known by the technology of computer and these patterns of photographic means duplication of production.

In the production of low-denomination banknotes, as long as on banknote, make transparent " window ", just can obtain a kind of false proof measure that prevents the suitable grade of forging.As mentioned above, this window can guarantee that scanner or color copy machine can't copy banknote.In addition, can also be combined with other protection feature in banknote or on the banknote, for example the mark that falls to print is errorless with protection anti-counterfeiting characteristic thing and assurance printing.

Have found that, with the present invention similar but the thin slice that adopts " cross orientation " easily takes place when 66 ℃ of (150) above temperature curling.The thin slice of this cross orientation and thin slice of the present invention are similar, but difference is, the second layer is in turn laminated on the thin slice substrate, and the first direction (being principal direction) that the orientation of the second layer is extended is perpendicular basically with the first direction (principal direction) that the orientation of ground floor is extended.Can be sure of that this curl is because each layer different along machine direction and horizontal amount of contraction at high temperature.The factor of easily curling in addition may be the constriction coefficient that coating or constriction coefficient that the top layer had are different from high-density polyethylene layer.By the equilibrium of overall shrinkage, a second layer as ground floor mirror image identical with ground floor is laminated on the ground floor, just can prevent the unequal and curling tendency of amount of contraction.So-called mirror image is meant that half and another half-phase of laminated foil structure are mirror image, and symmetrical plane is along the horizontal central line of laminated foil structure cross section.This just provides a kind of laminated foil structure of cross section symmetry.The example of this class thin slice comprises ABA, ABBA, and structures such as ABCCBA and ABCDCBA, wherein thin layer represented respectively in each letter, resin bed, coating, or adhesive linkage.In order to satisfy the mirror image requirement, the laminated foil structure of this class cross section symmetry needs the structure of " parallel orientation ", that is, the principal direction of the principal direction that the orientation of ground floor is extended and the orientation stretching of the second layer is parallel to each other.This formation provides symmetrical structure, wherein opposite convergent force sizable ratio of having cancelled out each other.Yet, this two-layer parallel structure easily in one direction, promptly transversely (TD) wear resistant is poor, this structure has adopted along horizontal (TD) directed two thin layers that extend.

Have now found that, use the lamination adhering resin of a kind of like this LLDPE (LLDPE), the principal direction that its orientation is extended be substantially perpendicular to it the orientation of the bonding thin layer principal direction of extending, just be difficult for tearing.The orientation that the lamination adhering resin itself can be subjected in lamination process is to a certain degree extended, preferably resin solidify fully or be at least partly solidified after, and preferably extend along machine direction.This extension can be 1.5～10 times, preferably 4～6 times, and be equivalent to the lamination adhering resin and totally roll greater than 10%, more preferably greater than 20%, such as 75%.

Have found that, when the molecular weight of used lamination adhering resin increases, for example use the bigger LLDPE of molecular weight (LLDPE), just can improve the directed extension effect of laminating technology, the composite wafer that produces all is improved along machine direction and horizontal wear resistant, shows good curling resistance simultaneously.

In another most preferred embodiment, the lamination adhering resin of extrusion modling itself is the ABA structure, that is, resin has the inner core (B layer) of LLDPE, and the outer or title top layer (A layer) of low density polyethylene (LDPE).The advantage that the ABA structure of lamination adhering resin is provided is, the A layer provides very high adhesive strength between lamination adhering resin and directed high-density polyethylene layer of extending, the core (B layer) of larger molecular weight has provided wear resistant in the horizontal along the directed result who extends of machine direction in lamination process simultaneously.When not having priming coat, only the scope of the adhesive strength that can be provided by the lamination adhering resin that low density polyethylene (LDPE) constituted is 300～800 gram/inches, and when having the priming coat of high density polyethylene (HDPE), increases to 600～1400 gram/inches.The product that this adhesive strength provided is very difficult to peel off, thereby has just reduced any possibility that the anti-counterfeiting characteristic thing that is arranged between the high-density polyethylene layer is destroyed.Use the lamination adhering resin of ABA structure also can provide identical adhesive strength, increased wear resistant transversely simultaneously at least from two aspects.

Following example is of the present invention illustrating, unless wherein indicate specially, all components are all calculated by weight.

Example 1: this example is in order to the manufacturing process of explanation according to the multi-layer thin substrate that the present invention produced, and this substrate is suitable for making the banknote with good dead pleat characteristic.

The multi-layer thin substrate that the orientation that final thickness is 1.15 mils is extended is that high density polyethylene (HDPE) is crushed to simultaneously together with the polypropylene copolymer top layer on its both sides, has formed a ground floor (a).Employed high-density polyethylene resin is Oxychem M-6211, can be from Texas, USA, and the Occidental Chemical Corp in Dallas city buys.This resin density is 0.96, and melt index is 1.0.The polypropylene copolymer top layer comprises 90% Chisso 7510, it is a kind of terpolymer of the ethylene-propylene-butene-1 that can buy from the Chisso company of Japan, the top layer also comprises 10% Mobil LKA-753 ,-kind of the low density polyethylene (LDPE) that can buy from the Mobil chemical company in Connecticut, USA Norwalk city.In made thin layer (a), high density polyethylene (HDPE) accounts for 90%, and the top layer accounts for 10% (each side each 5%).Also make the second layer (b) identical with ground floor (a).Then, the ground floor (a) and the second layer (b) extend 1.4 times in that about 115 ℃ of temperature lower edge machine directions are directed, and under 115 ℃～140 ℃ temperature 6～12 times of stenter upper edge horizontal expansions, for example 10 times.

On the inboard on orientation extension thin layer (a) and copolymer top layer (b), apply a polymine (PEI) then as priming coat, to form the thin layer of 1.15 transparent mil thick.

On thin layer (a) some optical change characteristic things (OVDs) can be set, the predetermined distance of being separated by each other is so that provide an optical change characteristic body at the same position place of each banknote.These banknotes are finally made by above-mentioned thin layer.

Thin layer (a) and (b) the lamination adhering resin by being located at the low density polyethylene (LDPE) between two-layer and lamination bonds to together, described adhering resin is Chevron 1017, can buy from the Chevron chemical company in Texas, USA Houston city.In lamination process, the directed extension takes place along machine direction in lamination adhering resin self, thereby strengthened the wear resistant on horizontal (TD).Lamination is implemented with conventional art, produces the multi-layer thin substrate that final thickness is about 3.0 mils, and wherein, the lamination adhering resin itself has occupied the thickness of about 0.7 mil.

The substrate that is produced is transparent substantially, and its physical characteristic is summarized in the following table.

Carry out intaglio printing with an opaque printing ink in the both sides of substrate then.Intaglio printing is carried out by this way, opaque printing ink or coating are applied round the optical change characteristic body that is embedded in the substrate, just to avoid covering the optical change characteristic body, thereby form a transparent window around described characteristic body, the optical change characteristic body can be seen in the both sides of feasible substrate after printing.About 3.75 mil thick of substrate after the intaglio printing, the printing after can twist on the roller, or stretching and align after block so that the thin slice of about 30 inches square easy pressures is provided, these thin slices then 5000 be packaged into a unit.This product shows good dead pleat feature, the wear resistant on both direction, and the printing fastness, and compare the only less printing ink of needs with the bank note substrate in when printing, however better definition but is provided.In addition, this product (180 are lasted 24 hours) under high reserve temperature also is difficult for taking place to curl.These characteristics of this product make it can substitute used traditional scraps of paper in the banknote printing valuably.

This product is difficult to peel off, thereby the optical change characteristic body is isolated, make to forge very difficulty of attempt, this have benefited from thin layer (a) and (b) between high adhesive strength.

Example 2:

This example has repeated example 1, and difference is that used lamination adhering resin is the adhering resin of the lamination level of a LLDPE, and Dowlex 3010, can buy from the Dow chemical company in Michigan, United States, Midland city.The property column of the substrate that is produced is in following table.In example 2, the LLDPE that uses HMW makes the intensity of tearing transversely increase as adhering resin.

Example 3

This example has repeated example 1, and difference is that used lamination adhering resin is the ABA structure, and wherein A is a low density polyethylene (LDPE), accounts for 20% (every side 10%) of adhering resin total amount, and B is a LLDPE, accounts for 80% of adhering resin total amount.The property column of the substrate that is produced is in following table.Use the lamination adhering resin of ABA structure to provide high adhesive strength at thin layer (a) with (b) at two-layer (a) with (b).Can be sure of, this be since be laminated to together the lamination adhering resin and the copolymer top layer in all contain the low density polyethylene (LDPE) composition.In addition, owing to there is the LLDPE of the easier directed HMW that extends in the inside of lamination adhering resin, because the orientation of the lamination adhering resin of ABA structure on machine direction extended, this just provides and has laterally torn intensity remarkably.

Form

Example 1 example 2 examples 3 stretching MD 666 (pound/square inch MD 16 20 20 * 10 ³) coefficient MD 356 380 380 rigidity MD 17 20 20 (gram) TD 21 24 24 tear intensity MD 89 63 80 (gram/mil) TD 45 20

Claims (20)

1. the multi-layer thin substrate of a lamination, it comprises a ground floor (a) and a second layer (b), both can be identical or different, every layer of high density polyethylene (HDPE) that comprises at least 50% weight ratio, described density is at least 0.94, and every layer of extension degree ratio along at least one first direction is big at least three times along the extension degree of a second direction, and described second direction is substantially perpendicular to first direction; And the described second layer (b) is laminated on the ground floor (a), thereby the first direction that the first direction that the orientation of the second layer (b) is extended and the orientation of ground floor (a) are extended is arranged in a straight line substantially.

2. thin substrate as claimed in claim 1 is characterized in that, the ground floor (a) and the second layer (b) also have the top layer of a propylene copolymer at least one side separately.

3. thin substrate as claimed in claim 2 is characterized in that, the ground floor (a) and the second layer (b) all have the top layer of a propylene copolymer on separately the inboard and the outside.

4. as each described thin substrate in the claim 1 to 3, it is characterized in that the propylene copolymer top layer comprises the low density polyethylene (LDPE) of 10%～20% weight ratio.

5. the described thin substrate of each claim as described above is characterized in that the second layer (b) is laminated on the ground floor (a) by hot pressing.

6. as each described thin substrate in the claim 1 to 4, it is characterized in that the thin substrate of multilayer also comprises the lamination adhering resin layer (c) between the both sides that are positioned at the ground floor (a) and the second layer (b).

7. thin substrate as claimed in claim 6 is characterized in that, the lamination adhering resin comprises low density polyethylene (LDPE) (LDPE), and/or LLDPE (LLDPE).

8. as claim 6 or 7 described thin substrates, it is characterized in that, between propylene copolymer top layer on the inboard of the ground floor (a) and the second layer (b) and lamination adhering resin, be provided with a priming coat.

9. as claim 6,7 or 8 described thin substrates, it is characterized in that lamination adhering resin layer (c) is the ABA structure, it comprises the inner layer B of LLDPE and two outer A of low density polyethylene (LDPE).

10. as claim 6, each described thin substrate in 7,8 or 9 is characterized in that, the lamination adhering resin comprises a kind ofly can make the bearing of trend of described resin be basically perpendicular to the described ground floor and the second layer along the directed component of extending of machine direction.

11. the described thin substrate of each claim is characterized in that as described above, first direction is horizontal (TD), and second direction is machine direction (MD).

12. the described thin substrate of each claim is characterized in that as described above, also has an anti-counterfeiting characteristic thing (d) between the ground floor (a) and the second layer (b).

13. thin substrate as claimed in claim 12 is characterized in that, anti-counterfeiting characteristic thing (d) is arranged between the priming coat on the inboard separately of the ground floor (a) and the second layer (b).

14. thin substrate as claimed in claim 13 is characterized in that, anti-counterfeiting characteristic thing (d) comprises at least a in the following characteristics thing: optical change characteristic body (OVD), and the magnetic characteristic thing, the electronic characteristic thing, or comprise the characteristic body of rare underground element.

15. thin substrate as claimed in claim 14, it is characterized in that, anti-counterfeiting characteristic thing (d) comprises an optical change characteristic body (OVD), this optical change characteristic body comprises following at least a: diffraction grating, liquid crystal is by ripple image or the similar image that the cross grating produces, biconvex lens and the transparent grid that it is superimposed with or does not superpose and reflect, the interference image that produces variation that local reflex and local transparent partition are opened or the coating of similar image, birefringence or ambipolar layer or zone plate.

16. thin substrate as claimed in claim 15 is characterized in that the optical change characteristic body comprises the diffraction grating of reflection, it has comprised a protruding spraying plating of the having printed diffraction pattern thermoplastic thin slice of metal.

17. the described thin substrate of each claim is characterized in that as described above, the outer opaque coating that scribbles is gone up at least one outside.

18. thin substrate as claimed in claim 17 is characterized in that, it also comprises a transparent window that penetrates thin substrate.

19. thin substrate as claimed in claim 18 is characterized in that, window is round the optical change characteristic body, thereby can see this characteristic body from the either side of described substrate.

20. the described thin substrate of each claim is characterized in that as described above, thin substrate is the form of marketable securities, for example banknote.