CN115884874A - Resin composition, resin sheet, multilayer body, and card - Google Patents

Abstract

The invention provides a resin composition capable of obtaining a resin sheet with excellent light shielding performance, thinness and excellent lamination performance, and a resin sheet, a multilayer body and a card using the resin composition. The present invention provides a resin composition comprising 25 to 79.5 parts by mass of a polycarbonate resin, 0.5 to 40 parts by mass of a polyester, and 20 to 50 parts by mass of titanium oxide.

Description

Resin composition, resin sheet, multilayer body, and card

Technical Field

The present invention relates to a resin composition, a resin sheet, a multilayer body, and a card.

Background

Conventionally, for security cards such as ID cards, e-passports, and non-contact IC cards, cards using a resin sheet or a multilayer body including a resin sheet have been used.

As an example of the layer structure of the security card, a multilayer body shown in fig. 1 is known. In fig. 1 (a) and (B), 10 denotes a multilayer body, 11 denotes a cover layer (transparent resin sheet), and 12 and 13 denote white core layers. The multilayer body 10 may further include a laser marking layer and the like. Further, an IC chip, an antenna, or the like is usually mounted in the white core layers 12 and 13 or between the layers. Further, by using the white core layers 12 and 13 having a shielding property, the IC chip, the antenna, and the like can be made invisible from the outside of the card. These layers (fig. 1 a) are bonded together by, for example, thermocompression bonding to form a multilayer body (fig. 1B). Such a security card is described in patent document 1, for example.

Documents of the prior art

Patent literature

Patent document 1: international publication No. 2018/163889

Disclosure of Invention

Technical problem to be solved by the invention

In recent years, security cards having transparent windows have also been studied. Fig. 2 shows an example of a security card (multilayer body) having a transparent window. In fig. 2 (a) to (C), 20 denotes a security card (multilayer body), 21 denotes a cover layer (transparent resin sheet), 22 denotes a white core layer, 23 denotes a transparent resin sheet, and 24 denotes a transparent window. The transparent window 24 is provided in the security card, for example, for preventing forgery or for providing design, and is a transparent window portion into which a part of the card surface of the card is introduced. As a method of manufacturing a multilayer body having a transparent window 24, there is a method of providing an opening (region where the white core layer does not exist) 25 in the white core layer 22 and arranging the layers in a stacked state (fig. 2 a), and bonding the layers by hot pressing. By doing this, a part of the transparent resin of the cover layer (transparent resin sheet) 21 or the transparent resin sheet 23 flows into the opening 25 (fig. 2B) during the hot pressing, and the transparent window 24 is formed (fig. 2C). In the case of manufacturing a transparent window by this method, the white core layer 22 needs to be thinned in order to fill the opening 25 sufficiently with the transparent resin. However, it is found that when the white core layer 22 is made thin, the light shielding property originally required for the white core layer 22 becomes poor. In particular, in order to provide the transparent window 24, a layer adjacent to the white core layer 22 (a layer denoted by reference numeral 23 in fig. 2) cannot be formed as a white core layer, and the transparent resin sheet 23 is required. That is, when the light shielding property of the white core layer 22 is deteriorated, the IC chip or the antenna incorporated in the security card (multilayer body) also sees through. Therefore, a thin resin sheet having excellent shielding properties is required. Further, such a thin resin sheet is also required to have a lamination performance with the transparent resin sheet and the like.

An object of the present invention is to solve the above-described problems and to provide a resin composition capable of providing a resin sheet excellent in light shielding performance, thinness, and excellent in lamination performance, and a resin sheet, a multilayer body, and a card using the resin composition.

Technical solution for solving technical problem

The present inventors have conducted studies to solve the above-described problems, and as a result, have found that the above-described problems can be solved by the following means.

< 1 > a resin composition comprising 25 to 79.5 parts by mass of a polycarbonate resin, 0.5 to 40 parts by mass of a polyester and 20 to 50 parts by mass of titanium oxide.

< 2 > the resin composition as described in < 1 > wherein the resin composition is prepared by JIS K7121: the glass transition temperature of the resin composition is 100 to 155 ℃ as measured by the method (DSC) defined in 1987.

< 3 > as described in < 1 > or < 2 >A resin composition having a melt volume flow rate (MVR) value of 2.0 to 50.0cm as measured in accordance with JIS K7210 ³ /10min。

The resin composition as described in any one of < 4 > to < 1 > -to < 3 >, wherein the viscosity average molecular weight of the polycarbonate resin is 20,000 to 35,000.

The resin composition of any one of < 5 > to < 1 > -4 >, wherein the resin composition further contains a colorant other than titanium oxide in a proportion of 5 to 150 mass ppm.

< 6 > the resin composition as < 5 >, wherein the above-mentioned other colorant comprises a colorant having an absorption maximum in a wavelength range of 450 to 650 nm.

< 7 > the resin composition as < 5 >, wherein the above-mentioned other colorant comprises carbon black.

< 8 > such as < 5 > or < 6 > wherein the above-mentioned other coloring agent comprises a dye.

The resin composition according to any one of < 9 > to < 1 > -8 >, wherein the resin composition further contains an antioxidant in an amount of 0.01 to 0.2 mass%.

The resin composition of any one of < 10 > such as < 1 > -to < 9 >, which further contains an antistatic agent.

The resin composition according to any one of < 11 > to < 1 > -to < 10 >, wherein the polyester comprises an aliphatic polyester, and the content of the aliphatic polyester is 1 to 9 parts by mass.

< 12 > the resin composition as < 11 >, wherein the aliphatic polyester contains a structural unit derived from a lactone compound.

< 13 > the resin composition as < 11 >, wherein the above aliphatic polyester comprises polycaprolactone.

The resin composition according to any one of < 14 > to < 1 > -10 >, wherein the polyester comprises an aromatic polyester, and the aromatic polyester is contained in an amount of 10 to 40 parts by mass.

< 15 > the resin composition as defined in any one of < 1 > -14 > for a card.

< 16 > a resin sheet comprising the resin composition as defined in any one of < 1 > to < 15 >.

< 17 > the resin sheet as described in < 16 > wherein the thickness is 20 to 200. Mu.m.

The resin sheet described in < 18 > such as < 16 > or < 17 > wherein the total light transmittance is 0 to 20%.

The resin sheet of any one of < 19 > to < 16 > - < 18 >, wherein T x T is 200 to 750, where T% is a total light transmittance of the resin sheet and T μm is a thickness of the resin sheet.

The resin sheet of any one of < 20 > and < 16 > to < 19 >, wherein the resin sheet has a surface roughness Ra of 0.4 to 3.0 μm on at least one side.

< 21 > such as < 16 > to < 20 >, wherein the resin sheet has a surface roughness Ra of 0.4 to 3.0 μm on the first surface and a surface roughness Ra of 0.1 to 2.5 μm smaller on the second surface than on the first surface.

The resin sheet of any one of < 22 > to < 16 > to < 21 >, wherein 1m is on a sheet surface of the resin sheet ² In the above-described embodiments, the number of foreign matters having a size of 0.5mm or more, which is obtained by averaging the lengths of the long side and the short side by microscopic observation, is 0 to 10.

< 23 > a multilayer body having the resin sheet described in any one of < 16 > - < 22 >.

< 24 > the multilayer body according to < 23 >, comprising at least 2 resin sheets of any one of < 16 > -to < 22 >, wherein 2 of the resin sheets are located at symmetrical positions with respect to a center plane in a direction perpendicular to a thickness direction of the cross section in a cross section direction of the multilayer body.

< 25 > the multilayer body described in < 23 > or < 24 >, wherein at least 1 of interlayer sheets constituting the multilayer body is the resin sheet described in any one of < 16 > to < 22 > and has at least 1 or more openings in the sheet surface.

The multilayer body of < 26 > as defined in any one of < 23 > to < 25 >, wherein the multilayer body has a structure in which the resin sheet of any one of < 16 > to < 22 >, the transparent resin sheet, and the resin sheet of any one of < 16 > to < 22 > are laminated in this order.

The multilayer body according to any one of < 27 > to < 23 > to < 26 >, wherein the surface roughness Ra of both surfaces of the multilayer body is 0.1 to 3.5 μm, respectively.

The multilayer body according to any one of < 28 > to < 23 > - < 27 >, wherein the total thickness of the multilayer body is 0.2 to 2.0mm.

The multilayer body of any one of < 29 > to < 23 > - < 28 >, wherein the laser colorant is contained in at least 1 layer of the multilayer body.

The multilayer body of any one of < 30 > such as < 23 > - < 29 >, which further has a layer containing a colorant that emits visible light by irradiation of ultraviolet light or infrared light.

< 31 > the multilayer body as < 30 > further having a layer containing a colorant which emits visible light having a wavelength different from that of the above colorant emitting visible light by irradiation with ultraviolet light or infrared light.

< 32 > a card comprising the resin sheet described in any one of < 16 > - < 22 > or the multilayer body described in any one of < 23 > - < 31 >.

< 33 > As < 32 > the card is a security card.

Effects of the invention

The present invention can provide a resin composition that can provide a resin sheet having excellent light shielding properties, being thin and having excellent lamination properties, and a resin sheet, a multilayer body, and a card using the resin composition.

Drawings

Fig. 1 is a schematic diagram showing an example of a layer structure of a conventional security card.

Fig. 2 is a schematic diagram showing an example of a layer structure of a security card (multilayer body) having a transparent window.

Fig. 3 is a schematic diagram for explaining the layer constitution of a security card (multilayer body) having a transparent window.

Fig. 4 is a schematic view showing the size of a multilayer body having a transparent window (opening) produced in the example.

Detailed Description

The following describes a specific embodiment (hereinafter, simply referred to as "the present embodiment") in detail. The following embodiments are merely examples for illustrating the present invention, and the present invention is not limited to the embodiments.

In the present specification, "to" are used in a meaning including numerical values described before and after the "to" as a lower limit value and an upper limit value.

In the present specification, unless otherwise specified, various physical property values and characteristic values are values at 23 ℃.

In the present specification, "sheet" and "multilayer body" mean a substantially flat molded body having a small thickness with respect to the length and width, and include "film". In the present specification, the "sheet" may be a single layer or a plurality of layers, and is preferably a single layer.

In the present specification, "part by mass" means a relative amount of a component, and "mass%" means an absolute amount of the component.

The resin composition of the present embodiment is characterized by containing 25 to 79.5 parts by mass of a polycarbonate resin, 0.5 to 40 parts by mass of a polyester, and 20 to 50 parts by mass of titanium oxide. With this configuration, a resin sheet having excellent light shielding performance, thinness, and excellent lamination performance can be provided.

In other words, by making an extremely thin resin sheet from a resin composition having an increased titanium oxide content, a resin sheet having excellent barrier properties and transparent window moldability can be obtained. As a result, even when used for a white core layer of a security card having a transparent window, an IC chip and the like contained in the security card can be effectively concealed. In addition, in the present embodiment, by blending a polyester, a resin composition having excellent lamination performance can be obtained.

< polycarbonate resin >

The resin composition of the present embodiment contains a polycarbonate resin. The polycarbonate resin functions as a matrix for the resin sheet.

The polycarbonate resin is not particularly limited as long as it is a resin containing a- [ O-R-OCO ] -structural unit (R is a hydrocarbon group (for example, an aliphatic group, an aromatic group, or a group containing both an aliphatic group and an aromatic group, and a group having a linear structure or a branched structure)) having a carbonate bond in the molecular main chain, and various polycarbonate resins can be used.

In the present embodiment, an aromatic polycarbonate resin is preferable, and a bisphenol type polycarbonate resin is more preferable. The bisphenol type polycarbonate resin means that 80 mol% or more, preferably 90 mol% or more of the structural units constituting the polycarbonate resin are carbonate structural units derived from bisphenol (preferably bisphenol a) and/or derivatives thereof.

The bisphenol type polycarbonate resin is preferably a bisphenol A type polycarbonate resin.

The molecular weight of the polycarbonate resin is not particularly limited, and in general, the viscosity-average molecular weight in terms of the solution viscosity measured at a temperature of 25 ℃ using methylene chloride as a solvent is preferably 20,000 or more. The viscosity average molecular weight is preferably 35,000 or less, more preferably 32,000 or less, still more preferably 29,000 or less, further preferably 25,000 or less, and may be 23,000 or less. By using such a polycarbonate resin, uniform dispersion of the raw materials of the resin composition during melt extrusion can be promoted, and occurrence of white peelings can be effectively suppressed. More specifically, when the viscosity average molecular weight is not less than the lower limit, the viscosity during melt kneading can be increased, the uniform dispersibility of the raw materials of the resin composition in the extruder tends to be improved, and foreign matter due to poor kneading of the raw materials tends to be less likely to occur. Further, when the viscosity average molecular weight is not more than the upper limit, the moldability tends to be improved.

In the present embodiment, 2 or more polycarbonate resins having different viscosity-average molecular weights may be used in combination, and in this case, a polycarbonate having a viscosity-average molecular weight outside the above-described appropriate range may be used in combination.

Wherein the viscosity average molecular weight [ Mv ]]It is determined by measuring the intrinsic viscosity [ eta ] at 25 ℃ using methylene chloride as a solvent and an Ubbelohde viscometer](unit dL/g) from the Schnell viscosity formula, i.e.. Eta = 1.23X 10 ^－4 Mv ^0.83 The calculated value. In addition, the intrinsic viscosity [. Eta. ]]Means that the concentration [ C ] of each solution was measured]Specific viscosity at (g/dL) [. Eta. ] _sp ]The value is calculated by the following equation.

Further, details of the polycarbonate resin may be referred to in paragraphs 0011 to 0020 of japanese patent application laid-open No. 2012-144604 and paragraphs 0014 to 0035 of japanese patent application laid-open No. 2019-002023 without departing from the gist of the present embodiment, and these contents are incorporated into the present specification.

The resin composition of the present embodiment preferably contains the polycarbonate resin in a proportion of 25 to 79.5% by mass, and more preferably 40 to 75% by mass, in the resin composition.

The resin composition of the present embodiment may contain only 1 kind of polycarbonate resin, or may contain 2 or more kinds. When 2 or more species are contained, the total amount is preferably within the above range.

< polyester >

The resin composition of the present embodiment may contain a polyester. The resin composition of the present embodiment contains a polyester, and thus the laminatability of the resin sheet can be improved.

The type of the polyester is not particularly limited, and may be an aliphatic polyester or an aromatic polyester containing an aromatic ring.

In the present embodiment, the type of the aliphatic polyester is not particularly limited, and the aliphatic polyester preferably contains a structural unit derived from a lactone compound. Since such an aliphatic polyester has an extremely low glass transition point and excellent compatibility with a polycarbonate resin, a good lamination characteristic can be obtained by adding a small amount of the aliphatic polyester, and a decrease in chemical properties and mechanical properties of the polycarbonate resin can be effectively suppressed. In the present embodiment, the proportion of the structural unit derived from the lactone compound in the aliphatic polyester is preferably 70 mol% or more, more preferably 80 mol% or more, even more preferably 90 mol% or more, even more preferably 95 mol% or more, and even more preferably 99 mol% or more of the total structural units other than the terminal group.

Examples of the lactone compound include epsilon-caprolactone, beta-propiolactone and delta-valerolactone, and epsilon-caprolactone is preferable. Further, a copolymer of2 or more of these lactone compounds may be used.

The aliphatic polyester used in the present embodiment is preferably polycaprolactone.

The weight average molecular weight of the aliphatic polyester compound used in the present embodiment is preferably 5,000 to 90,000. More preferably from 7,000 to 60,000, still more preferably from 8,000 to 40,000, and still more preferably from 8,000 to 12,000. When the lower limit value is not less than the above-described lower limit value, the film formability tends to be further improved. When the above upper limit or less is set, the lamination property tends to be further improved. The weight average molecular weight is a polystyrene equivalent value measured by GPC (gel permeation chromatography).

When the resin composition of the present embodiment contains the aliphatic polyester, the aliphatic polyester is preferably contained in a proportion of 0.5% by mass or more, more preferably 1.0% by mass or more, and still more preferably 2% by mass or more in the resin composition. The resin composition of the present embodiment preferably contains the aliphatic polyester in a proportion of 9% by mass or less, more preferably 8% by mass or less, still more preferably 7% by mass or less, and may be 5% by mass or less and 3% by mass or less in the resin composition. When the lower limit value is not less than the above-mentioned lower limit value, the lamination property tends to be improved. When the upper limit value is not more than the above-mentioned upper limit value, moldability at the time of molding the resin sheet tends to be further improved.

In the present embodiment, the type of the aromatic polyester is not particularly limited, and is preferably a Polyester (PCTG) containing a structural unit derived from terephthalic acid, a structural unit derived from ethylene glycol, and a structural unit derived from cyclohexanedimethanol. The Polyester (PCTG) is a thermoplastic resin having excellent compatibility with a polycarbonate resin, and the decrease in durability of the polycarbonate resin due to the addition is small, and by using the polyester, a resin composition having excellent durability in addition to the laminatability can be obtained. The Polyester (PCTG) is obtained by substituting a part of ethylene glycol in a raw material monomer of polyethylene terephthalate with cyclohexanedimethanol. In the present embodiment, the proportion of the structural unit derived from cyclohexanedimethanol is preferably 50 mol% or more and less than 100 mol%, and more preferably 60 to 90 mol%, when the total of the structural unit derived from ethylene glycol and the structural unit derived from cyclohexanedimethanol is 100 mol%. The PCTG may contain a raw material monomer other than the structural unit derived from terephthalic acid, the structural unit derived from ethylene glycol, and the structural unit derived from cyclohexanedimethanol, within a range not departing from the gist of the present embodiment. In the present embodiment, the total of the structural unit derived from terephthalic acid, the structural unit derived from ethylene glycol, and the structural unit derived from cyclohexanedimethanol in PCTG is preferably 90 mol% or more, more preferably 95 mol% or more, and still more preferably 99 mol% or more of the total structural units excluding the terminal groups.

The aromatic polyester compound used in the present embodiment preferably has an intrinsic viscosity (IV value measured by a capillary viscometer: ISO1628-1 1998) of 0.5 to 1.0. More preferably 0.6 to 0.9, and particularly preferably 0.7 to 0.8. When the amount is within the above range, the film formability tends to be further improved.

When the resin composition of the present embodiment contains the aromatic polyester, the aromatic polyester is preferably contained in a proportion of 10% by mass or more, more preferably 15% by mass or more, and still more preferably 20% by mass or more in the resin composition. The resin composition of the present embodiment preferably contains the aromatic polyester at a ratio of 40% by mass or less, more preferably 35% by mass or less, and still more preferably 30% by mass or less in the resin composition. By setting the lower limit or more, the laminatability can be improved. When the upper limit value is not more than the above-mentioned upper limit value, the moldability at the time of sheet molding tends to be further improved.

< titanium oxide >

The resin composition of the present embodiment contains titanium oxide. By containing titanium oxide, a resin sheet having excellent shielding properties can be provided.

As the titanium oxide used in the present embodiment, titanium oxide which can be blended in a resin sheet can be widely used.

In the present embodiment, the titanium oxide is preferably rutile-type titanium oxide. By using the rutile type titanium oxide, decomposition of the polycarbonate resin can be suppressed. In addition, the surface of the titanium oxide is preferably treated with a surface treatment agent. That is, it is preferable to have a layer (especially, an organic layer) formed of a surface treatment agent on the surface of titanium oxide. With such a configuration, titanium oxide is easily dispersed in the polycarbonate resin, and a resin sheet having a more excellent appearance can be obtained. Further, decomposition of the polycarbonate resin during melt extrusion can be effectively suppressed. The surface treatment agent may be exemplified by a polymer, preferably a siloxane compound, particularly preferably hydrogenmethylsiloxane, dimethylsiloxane or the like. The surface treatment agent can be physically adsorbed on the surface of titanium oxide, and can also be chemically bonded.

In addition, the titanium oxide may have an oxide layer between the titanium oxide and the layer formed of the surface treatment agent. The oxide layer contributes to retention of the granular shape, suppression of resin decomposition, and the like. Examples of the oxide layer include an aluminum oxide layer, a silicon dioxide layer, and a zirconium oxide layer. The oxide layer may be only 1 type of layer, or may have a plurality of layers.

The titanium oxide used in the present embodiment is preferably in the form of particles.

The average primary particle diameter of titanium oxide is preferably 100nm or more, more preferably 150nm or more, still more preferably 180nm or more, and may be 220nm or more. The average primary particle diameter of titanium oxide is preferably 500nm or less, more preferably 400nm or less, still more preferably 350nm or less, and may be 300nm or less and 260nm or less. When the average primary particle diameter of titanium oxide is in such a range, the shielding performance tends to be further improved.

The average primary particle size of titanium oxide was measured in the manner described in examples below.

The resin composition of the present embodiment preferably contains titanium oxide in an amount of20 to 50% by mass, more preferably 25 to 45% by mass, and still more preferably 25 to 35% by mass, of the resin composition. When the lower limit value is not less than the above-mentioned lower limit value, the masking property of the obtained resin sheet tends to be further improved. When the upper limit value is less than or equal to the above upper limit value, the resultant resin sheet can be effectively inhibited from suffering from white peeling, and the film formability tends to be further improved.

< blending ratio of polycarbonate resin, polyester and titanium oxide >

The resin composition of the present embodiment contains 25 to 79.5 parts by mass of a polycarbonate resin, 0.5 to 40 parts by mass of a polyester (the content of the aliphatic polyester is preferably 0.5 to 9 parts by mass, and the content of the aromatic polyester is preferably 10 to 40 parts by mass), and 20 to 50 parts by mass (preferably 22 parts by mass or more, more preferably 25 parts by mass or more, and preferably 40 parts by mass or less, more preferably 38 parts by mass or less, and more preferably 35 parts by mass or less) of titanium oxide. Further, an antioxidant, another colorant, an antistatic agent, and other components may be contained. By setting such a blending ratio, a resin sheet excellent in a shielding property and a laminating property can be obtained.

The first embodiment of the blending ratio of the resin composition of the present embodiment is that it contains 41 to 79.5 parts by mass (preferably 58 to 73 parts by mass) of a polycarbonate resin, 20 to 50 parts by mass (preferably 25 to 35 parts by mass) of titanium oxide, and further contains 0.5 to 9 parts by mass (preferably 1 part by mass or more, more preferably 1.5 parts by mass or more, still more preferably 2.0 parts by mass or more, and preferably 9 parts by mass or less, more preferably 7 parts by mass or less, still more preferably 5 parts by mass or less, and 3 parts by mass or less) of a polyester (preferably an aliphatic polyester). The resin sheet obtained from the resin composition of such blending system is suitably used for a reflective sheet, a card product, and the like.

The second embodiment of the blending ratio of the resin composition of the present embodiment comprises 25 to 70 parts by mass (preferably 35 to 60 parts by mass) of the polycarbonate resin, 20 to 50 parts by mass (preferably 25 to 35 parts by mass) of the titanium oxide, and 10 to 40 parts by mass (preferably 20 parts by mass or more and preferably 30 parts by mass or less) of the polyester (preferably the aromatic polyester). The resin sheet obtained from the resin composition of such blending system is suitable for a white core layer of a card having a transparent window. In particular, the resin composition of the present embodiment is preferable because titanium oxide has high dispersibility and can achieve sufficient shielding properties even in an extremely thin resin sheet.

The resin composition of the present embodiment preferably satisfies the above-mentioned ratio when the total amount of the polycarbonate resin, titanium oxide and polyester is 100 parts by mass.

In the resin composition of the present embodiment, the total amount of the polycarbonate resin, the polyester, and the titanium oxide is preferably 90 mass% or more, more preferably 95 mass% or more, and may be 98 mass% or more of the resin composition. The upper limit is 100 mass% or less.

In the resin composition of the present embodiment, the difference between the content of the polycarbonate resin and the content of the titanium oxide (the content of the polycarbonate resin — the content of the titanium oxide) is preferably 10 parts by mass or more, and more preferably 59.5 parts by mass or less. When the amount is within this range, the film formability tends to be further improved.

In the resin composition of the present embodiment, the content of the polycarbonate resin is preferably larger than the content of the polyester, and preferably 1 part by mass or more. The upper limit of the difference between the polycarbonate resin content and the polyester content is 76 parts by mass or less. When the amount is in such a range, a resin composition which is thin and has more excellent lamination performance tends to be obtained while the physical properties and light shielding performance of the polycarbonate are maintained at a high level.

In the resin composition of the present embodiment, only 1 type of each of the polycarbonate resin, the polyester, and the titanium oxide may be used, or 2 or more types may be used. When 2 or more species are used, the total amount is preferably in the above range.

< other coloring Agents >

The resin composition of the present embodiment may further contain a colorant other than titanium oxide. By adding another colorant, the resin composition can be colored slightly, and the appearance (design) of the resin sheet tends to be improved. The light shielding performance can be further improved.

Examples of the other colorants include inorganic pigments, organic pigments, and organic dyes.

Examples of the inorganic pigment include sulfide-based pigments such as carbon black, cadmium red, and cadmium yellow; silicate pigments such as ultramarine blue; oxide-based pigments such as zinc white, iron red, chromium oxide, iron black, titanium yellow, zinc-iron-based brown, titanium-cobalt-based green, cobalt blue, copper-chromium-based black, and copper-iron-based black; chromic acid-based pigments such as chrome yellow and molybdate orange; and ferrocyanide pigments such as prussian blue.

Examples of the organic pigment and the organic dye include phthalocyanine-based dyes and pigments such as copper phthalocyanine blue and copper phthalocyanine green; azo dyes or pigments such as nickel azo yellow; fused polycyclic dyes or pigments such as thioindigo-based, perinone-based, perylene-based, quinacridone-based, dioxazine-based, isoindolinone-based, quinophthalone-based and the like; dyes and pigments of anthraquinone system, heterocyclic system and methyl system.

Specific examples of the other colorants include colorants having maximum absorption in a wavelength range of 450 to 650 nm. The masking property of the resin sheet can be improved by incorporating a colorant having a maximum absorption in the wavelength range of 450 to 650nm, which can effectively absorb light of a wavelength around 550nm that is sharply perceived by humans.

It is also possible to exemplify the manner in which the above-mentioned other colorant is a dye. Examples of the dye include colorants having maximum absorption in the wavelength range of 450 to 650 nm.

Further, as a specific example of the other colorant, the carbon black can be mentioned. By blending carbon black, the light shielding performance of the resin sheet can be further improved.

When the resin composition of the present embodiment contains another colorant, the content thereof is preferably 5 mass ppm or more, more preferably 7 mass ppm or more, still more preferably 10 mass ppm or more, further preferably 15 mass ppm or more, and may be 20 mass ppm or more in the resin composition. The upper limit of the content of the other coloring agent is preferably 150 mass ppm or less, more preferably 120 mass ppm or less, still more preferably 100 mass ppm or less, and further preferably 80 mass ppm or less. When the amount is within this range, the appearance of the resulting resin sheet tends to be further improved, and the light shielding performance tends to be further improved.

The resin composition of the present embodiment may contain only 1 kind of other coloring agent, or may contain 2 or more kinds. When 2 or more species are contained, the total amount is preferably in the above range.

< various additives >

The resin composition of the present embodiment may further contain various additives.

The resin composition of the present embodiment preferably contains an antioxidant. The resin composition of the present embodiment preferably contains the antioxidant in an amount of 0.01 to 0.2% by mass, more preferably 0.02 to 0.1% by mass, based on the resin composition. By containing the antioxidant, thermal decomposition during processing can be suppressed, and color tone change and reduction in melt viscosity tend to be prevented. The antioxidant is not particularly limited in kind, and includes phosphites and phosphonites, with phosphites being preferred. As the antioxidant, reference is made to the descriptions in paragraphs 0059 to 0061 of jp 2018-090677 a, which are incorporated herein by reference.

The resin composition of the present embodiment preferably further contains an antistatic agent. The resin composition of the present embodiment preferably contains the antistatic agent in an amount of 0.01 to 1.5% by mass, more preferably 0.1 to 0.8% by mass, based on the resin composition. When used in such a range, dust adhesion resistance and transportability tend to be further improved.

The antistatic agent is not particularly limited in kind, and phosphonium salt compounds are exemplified. Specific examples of the antistatic agent include phosphonium salt compounds described in Japanese patent laid-open publication No. 2016-108424 and International publication No. 2020/122055, which are incorporated herein by reference.

The resin composition of the present embodiment may contain other components than those described above. As the other component, at least one additive selected from a heat stabilizer, a flame retardant aid, an ultraviolet absorber, and a mold release agent, and the like are included. Further, a fluorescent whitening agent, an antifogging agent, a flowability improver, a plasticizer, a dispersant, an antibacterial agent, an antiviral agent, and the like may be added within a range not to impair desired physical properties.

The content of the other components in the resin composition of the present embodiment is, for example, 0.001 mass% or more, and for example, 5.0 mass% or less, preferably 3.0 mass% or less, and more preferably 1.0 mass% or less, based on the mass of the resin composition, when contained.

< physical Property value of resin composition >

By JIS K7121: the glass transition temperature of the resin composition of the present embodiment measured by the method (DSC) defined in 1987 is preferably 100 ℃ or higher, more preferably 110 ℃ or higher, still more preferably 120 ℃ or higher, and may be 125 ℃ or higher. When the content is not less than the lower limit, the durability of the resin composition tends to be further improved. The glass transition temperature is preferably 155 ℃ or lower, more preferably 150 ℃ or lower, still more preferably 148 ℃ or lower, still more preferably 145 ℃ or lower, yet still more preferably 140 ℃ or lower, and yet still more preferably 135 ℃ or lower. By being not more than the above upper limit, moldability at a lower temperature can be obtained.

In addition, the resin composition of the present embodiment preferably has a melt volume flow rate (MVR) value of 2.0cm measured at 300 ℃ under a load of 1.2kgf in accordance with JIS K7210 ³ A/10 min or more, more preferably 3.0cm ³ A concentration of at least 10min, more preferably 5.0cm ³ A concentration of 10min or more, more preferably 8.0cm ³ A concentration of 10min or more, more preferably 10.0cm ³ A concentration of 10min or more, more preferably 12.0cm ³ More than 10 min. When the content is not less than the lower limit, the uniform dispersibility of the raw material of the resin composition in the extruder can be improved, and foreign matters due to poor kneading of the raw material tend to be further reduced. In addition, the upper limit value of the MVR is preferably 50.0cm ³ Less than 10min, more preferably 40.0cm ³ Less than 10min, more preferably 35.0cm ³ A concentration of 30.0cm or less, preferably 10min or less ³ Less than 10min, more preferably 25.0cm ³ Less than 10min, also can be 19.0cm ³ Less than 10min and 16.0cm ³ Less than 10 min. When the content is less than the above upper limit, the film formation tends to be further improved.

The glass transition temperature and the melt volume flow rate were measured as described in examples below.

< Property of resin sheet >

The resin sheet of the present embodiment is a resin sheet formed of a resin composition. The resin sheet of the present embodiment is preferably used as a structural layer of a card. That is, the resin composition of the present embodiment is suitable as a resin composition for cards.

In the resin sheet of the present embodiment, the lower limit of the thickness is preferably 20 μm or more, and more preferably 25 μm or more. The upper limit of the thickness is preferably 200 μm or less, more preferably 180 μm or less, still more preferably 150 μm or less, further preferably 120 μm or less, further preferably 110 μm or less, further preferably 100 μm or less, further preferably 80 μm or less, and may be 70 μm or less and 60 μm or less. When the content is not less than the lower limit value, the light shielding performance of the resin sheet tends to be further improved. By being equal to or less than the above upper limit, the formability of the multilayer sheet having a transparent window structure can be further improved.

The resin sheet of the present embodiment preferably contains a small amount of foreign matter. Specifically, the sheet surface 1m of the resin sheet ² The number of foreign matters having a size of 0.5mm or more obtained by averaging the lengths of the long side and the short side as observed by a microscope is preferably 0 to 10, more preferably 0 to 5, and still more preferably 0 to 3. In the present embodiment, in order to improve the light shielding property of the resin sheet, it is necessary to contain titanium oxide at a high concentration. On the other hand, when titanium oxide is contained at a high concentration and an extremely thin resin sheet is produced as described above, a region having low shielding performance which is elongated in the sheet take-up direction may be present in the resin sheet,a partially bright and striped appearance known as "white streaks" is poor. In the present embodiment, the number of foreign matters having a diameter of 0.5mm or more among the foreign matters contained in the resin sheet is set to the above range or less, whereby the occurrence of white peelings can be suppressed more effectively.

As a method for reducing the number of foreign matters having a particle diameter of 0.5mm or more, a polycarbonate resin having a viscosity average molecular weight of20,000 to 35,000 (particularly, 25,000 or less, further 23,000 or less) can be used. Further, a method of pulverizing or surface-treating titanium oxide can be mentioned. Further, it is preferable to set the extrusion conditions (melting temperature, screw configuration, screw rotation speed, discharge amount) during melt kneading within an appropriate range.

The number of foreign matters was measured by the method described in the examples below.

The resin sheet of the present embodiment is preferably excellent in light shielding properties. Specifically, the total light transmittance T is preferably 20% or less, preferably 15% or less, more preferably 12% or less, and still more preferably 10% or less. The lower limit of the total light transmittance is preferably 0% and may be 1% or more. The total light transmittance T was measured by the method described in the examples below.

In the resin sheet of the present embodiment, T × T is preferably 200 or more, more preferably 210 or more, even more preferably 220 or more, even more preferably 230 or more, and even more preferably 240 or more, where T% is the total light transmittance of the resin sheet and T μm is the thickness of the resin sheet. When the content is not less than the lower limit value, the light shielding property and the moldability tend to be improved in a good balance. The upper limit value is preferably 750 or less, more preferably 740 or less, still more preferably 730 or less, still more preferably 720 or less, and still more preferably 710 or less. When the content is not more than the above upper limit, the light shielding property and the moldability tend to be improved in a good balance.

In the resin composition of the present embodiment, the surface roughness Ra of at least one side surface is preferably 0.4 μm or more, more preferably 0.5 μm or more, still more preferably 0.7 μm or more, and may be 0.9 μm or more and 1.1 μm or more. When the amount is not less than the lower limit, the sheet has a tendency to be more excellent in transportability and lamination property. The upper limit value of the surface roughness Ra of the at least one surface is preferably 3.0 μm or less, more preferably 2.5 μm or less, and may be 2.0 μm or less, 1.8 μm or less, or 1.5 μm or less. When the content is less than the above upper limit, the printing sharpness tends to be further improved.

In the present embodiment, it is preferable that the surface roughness Ra of one surface of the resin sheet is in the above range (0.4 μm to 3.0 μm), and the surface roughness Ra of the other surface is 0.4 μm to 1.9 μm. With this configuration, the resin sheet can be more effectively conveyed and laminated.

In the resin sheet of the present embodiment, the surface roughness Ra of the first surface is preferably within the above range (0.4 to 3.0 μm), and the surface roughness of the second surface is preferably smaller than the surface roughness of the first surface by 0.1 to 2.5 μm (preferably 0.1 to 0.5 μm, more preferably 0.15 to 0.35 μm). With such a configuration, the sheet transportability and the lamination property tend to be further improved.

The surface roughness Ra was measured as described in examples below.

< method for producing resin sheet >

The method for producing the resin sheet of the present embodiment can employ a known method of processing a resin composition into a sheet shape. Specifically, extrusion molding and solution casting molding can be exemplified, and extrusion molding is preferable. An example of extrusion molding is a method in which pellets, flakes, or powder of the resin composition of the present embodiment is put into an extruder, melted and kneaded, and then extruded from a T die or the like, and the resulting semi-molten sheet is cooled and solidified while being nipped by rollers to form a sheet.

< multilayer body >

The multilayer body of the present embodiment has the resin sheet of the present embodiment. It is particularly preferable that at least 1 of the interlayer sheets of the multilayer body of the present embodiment is the resin sheet of the present embodiment, and has at least 1 or more openings in the sheet surface. Such an opening can be used, for example, as a transparent window of a security card. Further, since the resin sheet of the present embodiment is extremely thin and has excellent light shielding performance, sufficient light shielding performance can be achieved even in a multilayer body having a transparent window.

The multilayer body of the present embodiment preferably includes at least 2 resin sheets of the present embodiment, and the 2 resin sheets are located at symmetrical positions with respect to a center plane of a cross section in a direction perpendicular to the thickness direction in the cross section direction of the multilayer body. In particular, in the multilayer body of the present embodiment, in the thickness direction of the cross section, 2 of the resin sheets are preferably located at symmetrical positions with respect to the center plane of the cross section in the direction perpendicular to the thickness direction in the embodiment having the opening portion where the resin sheet of the present embodiment is not present. An example of such a multilayer body is the structure shown in fig. 3. Fig. 3 (a) is a view seen from the cross-sectional direction (thickness direction) of the multilayer body, and (B) is a view seen from the surface (sheet surface of the resin sheet) direction of the multilayer body. In fig. 3, 30 denotes a multilayer body, 31 denotes a cover layer (transparent resin sheet), 32 denotes a white core layer (resin sheet of the present embodiment), 33 denotes a transparent window (opening), and 34 denotes a transparent core layer (transparent resin sheet). base:Sub>A linebase:Sub>A-base:Sub>A indicated bybase:Sub>A broken line in fig. 3 (base:Sub>A) corresponds tobase:Sub>A position ofbase:Sub>A center plane inbase:Sub>A direction perpendicular to the thickness direction of the cross section of the multilayer body. The multilayer body shown in fig. 3 has a transparent window (opening) 33 in a region where the white core layer (the resin sheet of the present embodiment) is not present in the cross-sectional direction of the multilayer body. The white core layer (resin sheet in the present embodiment) 32 and the transparent window (opening) 33 are located at symmetrical positions with respect to the center plane (the plane through which the line indicated by the broken linebase:Sub>A-base:Sub>A in fig. 3 passes).

In the multilayer body shown in fig. 3, only the white core layer 32 appears white when viewed from the cross-sectional direction of the multilayer body shown in fig. 3 (a), and the entire portion other than the transparent window 33 appears white when viewed from the surface direction of the multilayer body shown in fig. (B) due to the white core layer 32.

In the multilayer body shown in fig. 3, the transparent window 33 can be produced by laminating the cover layer 31, the white core layer 32, the transparent core layer 34, the white core layer 32, and the cover layer 31 and then hot-pressing them. That is, the transparent window is formed by a portion (opening) of the transparent resin sheet entering (filling) the space between the white core layers 32 from the cover layer 31 and the transparent core layer 34 when hot-pressing is performed. Of course, the multilayer body of the present embodiment may be manufactured by other methods without departing from the scope of the present embodiment.

On the other hand, the transparent resin sheet constituting the cover layer 31 and the transparent core layer 34 is formed of a composition containing a thermoplastic resin, and for example, a resin composition obtained by removing titanium oxide from a resin composition used for forming the resin composition of the present embodiment can be exemplified. Therefore, an example of the transparent resin sheet is a polycarbonate resin sheet.

The multilayer body shown in fig. 3 has a structure in which the resin sheet (white core layer) 32 of the present embodiment, the transparent core layer (transparent resin sheet) 34, and the resin sheet (white core layer) 32 of the present embodiment are sequentially (preferably continuously) laminated, but this is not excluded.

The multilayer body of the present embodiment is not limited to the layer structure shown in fig. 3. Therefore, the multilayer body shown in fig. 3 may contain other layers without departing from the scope of the present invention.

The multilayer body of the present embodiment preferably contains a laser color former in at least 1 layer, for example. The layer containing the laser colorant is preferably used as the laser marking layer. Such a layer containing a laser color former is preferably provided further outside than the resin sheet of the present embodiment. That is, the white core layer is provided on the surface side of the white core layer 32 in fig. 3. The laser colorant is preferably a black colorant, and more preferably carbon black. In addition, a metal oxide-based laser marking agent can also be used. The details of the laser marking layer can be found in japanese patent application laid-open No. 2020-75487, which is incorporated herein by reference.

The multilayer body of the present embodiment may be exemplified as having a layer containing a colorant that emits visible light by irradiation with ultraviolet light or infrared light. By providing such a layer, the security card can be used as a security card that can be authenticated. That is, a card that emits light when a predetermined light is irradiated can be recognized as a genuine card.

In the present embodiment, the layer may have a structure including a colorant that emits visible light having a wavelength different from that of the colorant that emits visible light when irradiated with ultraviolet light or infrared light. In this case, the layer containing the colorant emitting visible light and the layer containing the colorant emitting visible light having a wavelength different from that of the colorant emitting visible light may be different layers or the same layer. That is, the present embodiment also includes a mode in which 2 or more kinds of colorants that emit visible light having different wavelengths are contained in the same layer.

In the multilayer body of the present embodiment, the layer containing a colorant that emits visible light is preferably provided on the outer side of the resin sheet of the present embodiment. That is, the core layer may be provided on the front surface side of the white core layer 32 in fig. 3.

As for the layer containing a colorant that emits visible light, the description of japanese patent application laid-open No. 2020-75487 can be referred to, and the contents thereof are incorporated in the present specification.

The multilayer body of the present embodiment preferably has a surface roughness Ra of 0.1 μm or more, more preferably 0.5 μm or more, respectively. When the amount is not less than the lower limit, the transportability and the laminatability of the multilayer body tend to be further improved. The upper limit of the surface roughness Ra of both surfaces of the multilayer body is preferably 3.5 μm or less, and more preferably 3.2 μm or less, respectively. When the amount is less than the upper limit, the printing sharpness tends to be further improved.

The thickness of the multilayer body of the present embodiment can be determined as appropriate depending on the application, and the total thickness is preferably 0.2mm or more, more preferably 0.3mm or more. When the lower limit or more is set as above, the IC chip and the antenna tend to be easily introduced. The upper limit of the total thickness is preferably 2.0mm or less, and more preferably 1.0mm or less. When the upper limit or less is set as above, the card storability tends to be further improved.

In the method for producing a multilayer body according to the present embodiment, in addition to the hot pressing of the respective constituent layers described above, the adhesiveness between the respective layers may be improved by an adhesive or the like within a range not departing from the gist of the present embodiment. Further, the sheet-like shape may be obtained by co-extruding the respective layers.

< use >)

Next, the use of the resin sheet and the multilayer body of the present embodiment will be explained. The resin sheet and/or multilayer body of the present embodiment is preferably used for a card containing the same.

The card is preferably a security card. Examples of the security card in the present embodiment include an identification card (ID card), a passport, a driver's license, a bank card, a credit card, a social security card, and other identification cards.

In the present embodiment, the contents of paragraphs 0048 to 0059 of japanese patent application laid-open No. 2016-108424 and paragraphs 0075 to 0088 of japanese patent application laid-open No. 2015-168728 can be referred to and incorporated in the present specification without departing from the gist of the present invention.

Examples

The present invention will be described more specifically with reference to examples. The materials, amounts used, ratios, treatment contents, treatment operations and the like shown in the following examples can be appropriately changed within a range not departing from the gist of the present invention. The scope of the present invention is therefore not limited to the specific examples described below.

In the case where the measuring instrument used in the examples is not easily available due to, for example, a sale stop, the measurement can be performed by using another instrument having the same performance.

1. Raw material polycarbonate resin

S-3000F: bisphenol a polycarbonate resin, IUPILON (registered trademark), viscosity average molecular weight mv21,000, manufactured by mitsubishi engineering plastics co.

< titanium oxide >

PFC317: rutile titanium oxide obtained by subjecting the surface of titanium oxide particles to silica treatment, alumina treatment and siloxane treatment in this order was produced by Shiyao corporation and had an average primary particle diameter of 0.24 μm (240 nm).

PFC310: rutile titanium oxide obtained by subjecting the surface of titanium oxide particles to silica treatment, alumina treatment and siloxane treatment in this order was manufactured by Shiyao industries, ltd., and had an average primary particle diameter of 0.20 μm (200 nm).

Method for measuring average primary particle size

The titanium oxide was subjected to sputtering treatment using a sputtering apparatus. The target was Pt and the coating time was 30 seconds. The titanium oxide subjected to the sputtering treatment was observed and photographed by a field emission scanning electron microscope. At the acceleration voltage when observed: 5kV, observation magnification: 3 ten thousand under 5000 times. The total of the major axis and the minor axis of titanium oxide was measured from the obtained image using image analysis software, and the value obtained by dividing the sum by 2 was determined as the particle diameter. The particle diameters of 50 or more particles were measured, and the average value thereof was calculated.

The measurement was carried out in the same manner by 3 experts, and the obtained average value was determined as the average primary particle diameter.

The sputtering apparatus used was E-1030 manufactured by Hitachi high tech. An FE-SEM (SU 8220, manufactured by Hitachi high-tech Co., ltd.) was used as the field emission type scanning electron microscope. WiROOF 2013 (manufactured by Sango Co., ltd.) was used as image analysis software.

< polyester >

H1P: polycaprolactone (PCL), PLACCEL (registered trademark) manufactured by Dacellosolve, inc., and weight-average molecular weight of 10000.

J2003: polyester (PCTG) consisting of terephthalic acid, ethylene glycol and 1, 4-cyclohexanedimethanol, SK chemical company, intrinsic viscosity 0.75.

< antioxidant >

AS2112: tris (2, 4-di-tert-butylphenyl) phosphite manufactured by the company ADEKA.

S-9228PC: doverphos S-9228PC, manufactured by Dover Chemical Co., ltd., bis (2, 4-dicumylphenyl) pentaerythritol diphosphite.

< antistatic agent >

Trihexyltetradecylphosphonium bis (trifluoromethanesulfonyl) amide: CAS number 460092-03-9, manufactured by MERCK corporation.

< other coloring agent >

Carbon black M280: MONARCH280 from CABOT.

Dye 1: macrolex BlueRR, a colorant having a maximum absorption in the wavelength range of 450 to 650 nm.

Dye 2: macrolex Violet3R, a colorant having maximum absorption in the wavelength range of 450 to 650 nm.

2. Examples 1 to 17 and comparative examples 1 to 3

< production of resin pellets >

Pellets of examples and comparative examples were produced by blending the respective components with a tumbler so as to have the compositions shown in tables 3 to 6 below (the contents in each table are expressed in parts by mass), charging the blend from the root of a twin-screw extruder (TEX 30 α, manufactured by japan steel manufacturing), and melt-kneading the blend at a cylinder temperature of 240 ℃.

< melt volume flow Rate (MVR) > < of the resin composition

The melt volume flow rate was measured in accordance with JIS K7210.

Specifically, the melt volume flow rate (unit: cm) was measured in terms of the amount of resin extruded per 10 minutes from a standard die provided at the bottom of a cylinder while a load of 1.2kgf was applied at 300 deg.C ³ /10min)。

< glass transition temperature of resin composition >

Glass transition temperature was measured by JIS K7121:1987 by the method (DSC).

Specifically, about 10mg of a sample was heated from 30 ℃ to 260 ℃ at a temperature rising rate of20 ℃/min under a nitrogen atmosphere using a differential scanning calorimeter. After keeping the temperature for 5 minutes, the mixture was cooled to 30 ℃ at a rate of 30 ℃/min. The temperature was maintained at 30 ℃ for 10 minutes, and the temperature was raised to 260 ℃ at a rate of 10 ℃/minute. The glass transition temperature (unit:. Degree. C.) was determined based on the extrapolated glass transition start temperature calculated from the DSC curve obtained at the 2 nd temperature rise.

The differential scanning calorimeter used was a differential scanning calorimeter EXSTAR DSC7020 manufactured by Hitachi high-tech, ltd.

< production of resin sheet >

Using the obtained pellets, a resin sheet was produced by the following method.

Using a T-die melt film molding extruder constituted by a twin-screw extruder having a cylinder diameter of 32mm and a screw L/D (length/diameter) =31.5, pellets were molded into a resin sheet having a width of 300mm at a screw rotation speed of 200rpm at a discharge amount of20 kg/h. The cylinder and the T die were set at 240 ℃ and the extruded molten sheet was nipped between a first silicone rubber cooling roll having a ten-point average roughness Rzjis (JIS B0601: 2013) of 21 μm and a second embossed metal cooling roll having a diameter of 250mm and a ten-point average roughness Rzjis (JIS B0601: 2013) of 18 μm. Thereafter, the sheet having the embossed texture on the surface thereof was further passed through a third cooling roll made of metal having a mirror surface, and was molded into resin sheets having thicknesses (average thicknesses) shown in tables 3 to 6 while being pulled by a pulling roll. At this time, the temperature of the first cooling roll was set to 50 ℃, the temperature of the second cooling roll was set to 100 ℃, and the temperature of the third cooling roll was set to 100 ℃.

< production of laminated sheet >

Using polycarbonate resin pellets E-2000 manufactured by Mitsubishi engineering plastics, a laminate sheet having an average thickness of 200 μm was produced in the same manner as in the production of the above resin sheet.

Next, the surface of the resulting laminate sheet facing a second metal cooling roll having an embossing diameter of 250mm and an average roughness Rzjis (JIS B0601: 2013) of 18 μm in ten points was defined as surface A.

< number of foreign matters >

The size of the cut sheet surface was 1m ² The resin sheet (2) was irradiated with S-Light from a distance of 60cm in the direction perpendicular to the sheet surface of the resin sheet, and the surface opposite to the surface irradiated with S-Light was visually observed. The length of the foreign matter was measured by a microscope, and the number of foreign matters having a size of 0.5mm or more was determined by averaging the lengths of the long side and the short side. Evaluation was performed by 5 experts to obtain the average (rounding the decimal point first).

The irradiation of S-Light was performed using an apparatus manufactured by Japan technology center. The microscope used was ECLIPSE LV100ND manufactured by Casio corporation.

< surface roughness (Ra) of resin sheet >

For any 3 positions of the surface of the obtained resin sheet, the thickness was adjusted in accordance with ISO 4287:1997, the surface roughness (measurement conditions: λ c0.8, λ s 2.5) was measured, and the surface roughness (Ra) was calculated by averaging 3 positions. The unit is μm.

For measurement, SURFTEST SJ-210, a small surface roughness measuring instrument manufactured by Mitutoyo corporation, was used.

< shading Performance >

Measurement of total light transmittance

The total light transmittance was measured in accordance with ISO-13468-1 (measurement conditions: D65 illuminant, 10 ℃ visual field).

For measurement, a haze meter HM-150 manufactured by color technology research institute in Chiura was used.

The unit of total light transmittance is%.

＜＜T×t＞＞

A value (T x T) obtained by multiplying the total light transmittance (T) (unit:%) by the thickness (T) (unit: μm) of the resin sheet was obtained. By adjusting this value within the range of 200 to 750, a multilayer body having both good moldability of the transparent window structure and good light shielding performance can be obtained.

< rate of change of size of transparent window >

The resin sheets obtained in the examples and comparative examples were punched out as shown in FIG. 4 to prepare sheets having rectangular openings of 25mm in width by 15mm in length. On both sides of the sheet, a rectangular laminating sheet cut into 150mm × 110mm was laminated with the laminating sheet so that the side a of the laminating sheet was in contact with the resin sheet, and lamination was performed under the conditions shown in table 1.

For lamination, a desktop card laminator OLA6E manufactured by OASYS was used.

[ Table 1]

The longitudinal dimensional change ratio (100 (15-L)/15) (unit:%) of the transparent window before and after lamination was determined from the minimum value (L) (unit: mm) of the longitudinal length of the transparent window after lamination.

When a transparent window is formed, if the white core layer is thin, part of the transparent resin component of the laminate sheet flows into the opening portion, and a good appearance is obtained. On the other hand, if the core layer is thick, the lamination sheet (transparent resin component) that can flow in is insufficient, and therefore, bubbles are generated in the transparent window, or a dent is generated on the surface. The white core layer itself may flow in to fill the opening portion, and the transparent window may be reduced. The small dimensional change of the transparent window indicates that a transparent window having excellent appearance can be obtained.

< lamination Property >

The resin sheets and the laminated sheets obtained in examples and comparative examples were punched out in a rectangular shape of 150mm × 110 mm.

The punched laminate sheet was laminated on both surfaces of the resin sheet so that the surface a side of the laminate sheet was in contact with the resin sheet obtained in each example or comparative example, and laminated under heat and pressure under the conditions shown in table 1 to obtain a multilayer body.

In the surface A (inner side of the multilayer body), ra was 0.99. Mu.m.

The Ra of the surface of the multilayer body when the multilayer body was laminated by sandwiching it from the top and bottom with a mirror SAS plate having a thickness of 0.75mm was 0.32 μm, and the Ra of the surface of the multilayer body when the multilayer body was laminated by sandwiching a release paper Optilam manufactured by Ahlstrom-Munksjo corporation between the mirror SAS plate and a resin sheet was 2.17 μm.

A desktop card laminator OLA6E manufactured by OASYS was used for lamination.

[ Table 2]

The lamination properties of the obtained multilayer body were evaluated as follows. Evaluation was performed by 5 experts, and majority voting was performed.

A: no appearance defects such as bubbles and adhesion defects were observed at the time of visual observation.

B: a is other than the above. For example, appearance defects such as bubbles and adhesion defects were visually observed.

< white tract >

The size of the cut sheet surface was 1m ² The resin sheet of (1) was irradiated with Light from a distance of 60cm in the vertical direction of the sheet surface of the resin sheet using S-Light manufactured by japan technology center, and the surface opposite to the irradiated surface was observed by visual observation, and the number of white peelings was determined by defining the appearance defect of a linear shape having a longest portion of 2mm or more as "white peelings".

Evaluation was performed by 5 experts, and the average value was obtained (rounding the decimal point to the first place).

< surface resistivity >

The antistatic property of the resin composition of example 14 was evaluated as follows.

The resin sheet to be measured was left to stand at a temperature of 23 ℃ and a relative humidity of 50% for 24 hours or more, and then a direct current voltage was applied thereto for 1000V 300 seconds by using a resistivity meter to measure the surface resistivity at 5 points (unit: Ω/sq.), and the average value was calculated.

The surface resistivity of the surface of the resin sheet of example 14 was 1.3X 10 ¹³ Omega/sq, surface resistivity of the back side of 2.0 × 10 ¹³ Ω/sq.。

The surface resistivity was measured by using a URS probe and HIRESTA UP MCP-HT450 (manufactured by ANALYTECH, mitsubishi chemical corporation).

[ Table 3]

[ Table 4]

[ Table 5]

[ Table 6]

Description of the symbols

10. 20, 30: multilayer bodies (security cards); 11. 21, 31: a cover layer (transparent resin sheet); 12. 22, 32: a white core layer; 13: a core layer; 23: a transparent resin sheet; 24: a transparent window; 25: an opening (region where the white core layer does not exist); 33: a transparent window (opening); 34: a transparent core layer (transparent resin sheet).

Claims (33)

1. A resin composition characterized by:

contains 25 to 79.5 parts by mass of a polycarbonate resin, 0.5 to 40 parts by mass of a polyester and 20 to 50 parts by mass of titanium oxide.

2. The resin composition according to claim 1, wherein:

by JIS K7121: the glass transition temperature of the resin composition is 100 to 155 ℃ as measured by DSC according to the method defined in 1987.

3. The resin composition according to claim 1 or 2, wherein:

the resin composition has a melt volume flow rate MVR value of 2.0 to 50.0cm measured in accordance with JIS K7210 ³ /10min。

4. The resin composition according to any one of claims 1 to 3, wherein:

the polycarbonate resin has a viscosity average molecular weight of20,000 to 35,000.

5. The resin composition according to any one of claims 1 to 4, wherein:

the resin composition further contains a colorant other than titanium oxide in an amount of 5 to 150 ppm by mass.

6. The resin composition according to claim 5, wherein:

the other colorant includes a colorant having an absorption maximum in a wavelength range of 450 to 650 nm.

7. The resin composition according to claim 5, wherein:

the other colorant comprises carbon black.

8. The resin composition according to claim 5 or 6, wherein:

the other colorant comprises a dye.

9. The resin composition according to any one of claims 1 to 8, wherein:

the resin composition further contains an antioxidant in an amount of 0.01 to 0.2% by mass.

10. The resin composition according to any one of claims 1 to 9, wherein:

also contains an antistatic agent.

11. The resin composition according to any one of claims 1 to 10, wherein:

the polyester comprises an aliphatic polyester, and the content of the aliphatic polyester is 1 to 9 parts by mass.

12. The resin composition according to claim 11, wherein:

the aliphatic polyester contains a structural unit derived from a lactone compound.

13. The resin composition according to claim 11, wherein:

the aliphatic polyester comprises polycaprolactone.

14. The resin composition according to any one of claims 1 to 10, wherein:

the polyester comprises an aromatic polyester, and the content of the aromatic polyester is 10 to 40 parts by mass.

15. The resin composition according to any one of claims 1 to 14, wherein:

which is used for cards.

16. A resin sheet characterized by:

formed from the resin composition of any one of claims 1-15.

17. The resin sheet according to claim 16, wherein:

the thickness is 20-200 μm.

18. The resin sheet according to claim 16 or 17, wherein:

the total light transmittance is 0 to 20%.

19. The resin sheet according to any one of claims 16 to 18, wherein:

t% is the total light transmittance of the resin sheet, and T [ mu ] m is the thickness, T x T is 200 to 750.

20. The resin sheet according to any one of claims 16 to 19, wherein:

the surface roughness Ra of at least one side surface of the resin sheet is 0.4-3.0 μm.

21. The resin sheet according to any one of claims 16 to 20, wherein:

the resin sheet has a first surface having a surface roughness Ra of 0.4 to 3.0 [ mu ] m, and a second surface having a surface roughness smaller than the surface roughness of the first surface by 0.1 to 2.5 [ mu ] m.

22. The resin sheet according to any one of claims 16 to 21, wherein:

on the sheet surface 1m of the resin sheet ² In the above method, the number of foreign matters having a size of 0.5mm or more obtained by averaging the lengths of the long side and the short side by microscopic observation is 0 to 10.

23. A multilayer body characterized by:

has the resin sheet according to any one of claims 16 to 22.

24. The multilayer body of claim 23, wherein:

comprising at least 2 resin sheets according to any one of claims 16 to 22, wherein 2 of the resin sheets are located at symmetrical positions with respect to a center plane in a direction perpendicular to a thickness direction of the cross section in a cross section direction of the multilayer body.

25. A multi-layer body as claimed in claim 23 or 24, wherein:

at least 1 of the interlayer sheets constituting the multilayer body is the resin sheet according to any one of claims 16 to 22, and has at least 1 or more openings in the sheet surface.

26. The multilayer body according to any one of claims 23 to 25, wherein:

the multilayer body has a structure in which the resin sheet according to any one of claims 16 to 22, a transparent resin sheet, and the resin sheet according to any one of claims 16 to 22 are laminated in this order.

27. The multilayer body according to any one of claims 23 to 26, wherein:

the surface roughness Ra of the two surfaces of the multilayer body is 0.1-3.5 mu m respectively.

28. The multilayer body according to any one of claims 23 to 27, wherein:

the total thickness of the multilayer body is 0.2 to 2.0mm.

29. The multilayer body according to any one of claims 23 to 28, wherein:

at least 1 layer of the multilayer body contains a laser chromophoric agent.

30. The multilayer body according to any one of claims 23 to 29, wherein:

and a layer containing a colorant that emits visible light by irradiation with ultraviolet light or infrared light.

31. A multi-layer body as claimed in claim 30, wherein:

and a layer containing a colorant emitting visible light having a wavelength different from that of the colorant emitting visible light by irradiation with ultraviolet light or infrared light.

32. A card, characterized in that:

comprising the resin sheet according to any one of claims 16 to 22 or the multilayer body according to any one of claims 23 to 31.

33. The card of claim 32, wherein:

which is a security card.

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