WO2005052080A1

WO2005052080A1 - Electromagnetic wave shielding water-base paint and basket obtainable therewith

Info

Publication number: WO2005052080A1
Application number: PCT/JP2004/017500
Authority: WO
Inventors: Masaaki Kumagai; Kenji Ebihara; Daisuke Matsunaga
Original assignee: Aica Kogyo Co.,Ltd.
Priority date: 2003-11-25
Filing date: 2004-11-25
Publication date: 2005-06-09
Also published as: JP2005179641A

Abstract

With respect to coating type electromagnetic wave shielding paints, it is common practice to use those of solvent type. These pose various problems, such as health and disaster prevention problems attributed to solvents and the problem of failing to detach coating from baskets after use because of difficulty in coating detachment. With respect to water-base paints, for example, the problem that employed metal powder is oxidized to thereby cause performance deterioration has been experienced. Consequently, there is a demand for a non-solvent type electromagnetic wave shielding paint free from performance deterioration and capable of re-detachment and for a basket obtainable therewith. The problems have been solved by an electromagnetic wave shielding water-base paint prepared by mixing silver powder or/and silver-coated copper powder in a resin emulsion; and a basket obtainable therewith.

Description

Specification

Electromagnetic shielding water-based paint and casing using the same

Technical field

The present invention relates to an electromagnetic wave shielding water-based paint used for inner and outer walls of buildings, housings of electronic equipment, and the like, and a housing using the same. More specifically, the present invention relates to a silver emulsion or Z and silver-coated copper powder. The present invention relates to an electromagnetic wave shielding water-based paint prepared by being blended in the above and a housing using the same. Background art

[0002] Electromagnetic waves are generated in large quantities, such as home appliances, personal computers, heating, lighting, communication-related electronic devices, electric devices used for various power sources, various power facilities, and various control systems. Such electromagnetic waves are generated everywhere and can enter the building or fly inside the building, causing malfunctions of electronic devices and leakage of security. In addition, concerns have been raised about the adverse effects of electromagnetic waves on human health, including the possibility of upsetting the body and causing leukemia.

[0003] As a countermeasure against such problems and anxiety, an electromagnetic wave shield using a conductive paint has been proposed.

As an example of the conductive paint, a material in which a conductive material, for example, metal powder such as copper, nickel, aluminum, and iron, carbon fiber, and the like are dispersed in a resin binder has been used.

[0004] However, the binder used is a resin binder obtained by dissolving a resin in an organic solvent. Therefore, when applied over a wide area, the organic solvent volatilizes and contaminates the surroundings. However, there are problems such as unfavorable health due to worker's suction and unfavorable fire prevention measures. In addition, there still remains a problem that electromagnetic shielding performance is not always sufficient.

In addition, when a conductive material such as a metal powder is combined with an aqueous binder, problems such as the settling of the conductive material and the deterioration of the electromagnetic wave shielding performance due to the spread of the metal powder remain. Was. In order to reduce the specific gravity to solve the problem of the conductive material settling in the binder solution, a method of preparing the conductive material by providing a plating layer on the surface of the resin hollow body or coating with a conductive paint Although methods are being studied, they are not adopted because of problems such as low productivity and high cost due to difficult processing in the isolated state and complicated processing steps.

Also, no effective method has been established for preventing metal powder.

[0005] Also, as is well known, electronic devices are rapidly being technologically renovated, and it is customary to replace them with new types in the next 13 years. When an electronic device coated with shielding paint is updated to a new type, the used device is discarded. On the other hand, cases in which materials molded from various resins used in the housing are recycled for effective use of resources are increasing, but if foreign matter is mixed in the housing, the purity of the material will be reduced. It is difficult to secure them, and the point of recycling is also an issue.

However, at present, the electromagnetic wave shielding paint applied to the inner wall of the housing dissolves and bonds the housing plastic with an organic solvent, which causes problems such as poor releasability and time-consuming recycling work! /

Patent document 1: JP-A-5-12917

Patent Document 2: JP-A-10-217397

Disclosure of the invention

Problems to be solved by the invention

[0006] The present invention solves the above-mentioned problems, that is, problems related to health and fire prevention management related to the organic solvent contained in the resin binder, and a problem that the electromagnetic wave shielding performance is deteriorated due to the increase of metal powder. Solved, and at the same time, while ensuring adhesion to the housing, the coating film swelled by immersion in alcohol, etc., causing the alcohol, etc. to enter the interface between the resin material and the coating film, and peeling off the coating film Therefore, it has been made to facilitate the recycling of the used resin materials as resources, and will be described in detail below.

Means for solving the problem

[0007] In order to solve the above-mentioned problems, in the present invention, silver powder or silver powder is used as a conductive material. The desired purpose could be achieved by preparing a combination of Z and silver-coated copper powder with an aqueous resin emulsion.

The invention's effect

[0008] Since the electromagnetic wave shielding water-based paint according to the present invention is based on a resin emulsion containing no organic solvent, there are no problems related to the volatilization of the solvent, such as health and disaster prevention. The coating operation can be performed with care.

In addition, since silver powder or Z and silver-coated copper powder are in a state of being coordinated or adsorbed to a hydrophilic group coordinated to the outside of the resin emulsion, it is stable and stable because it is possible to avoid iridescence. The effect is that high-performance conductivity and electromagnetic wave shielding properties can be ensured, and even if used for a long time, it can be used without any problem.

Further, by using copper powder as the conductive filler, it is possible to realize high-performance shielding performance as compared with conductive paint.

Furthermore, when used electronic equipment is outdated and discarded, the electromagnetic wave shielding water-based paint according to the present invention can be easily peeled from the housing while ensuring sufficient adhesion to the housing. Thus, the materials used for the housing can be easily recycled. BEST MODE FOR CARRYING OUT THE INVENTION

[0009] Silver powder is obtained by subjecting silver powder produced by a chemical reduction method to scaly shape by means of a vibrating mill, a planetary ball mill, a grinding method or the like, and having an average particle size of 0.1 to 80 m. Suitable for use. 0: Lm or less is not suitable because the viscosity is too high, and 80 m or more is unfavorable because of poor dispersibility.

[0010] The silver-coated copper powder is formed into a branched shape by an electrolytic method, or the copper powder further processed into a flake shape by a pulverizing method is coated with silver by a plating method to obtain an average particle size. 0.1 One 80 / zm is suitable for use. The smaller the particle size, the larger the surface area per weight and the higher the viscosity of the paint. 0 .: If it is less than Lm, the workability will be deteriorated due to the marked increase in viscosity. Further, if the increase in viscosity is adjusted by adding water or alcohol, the solid content of the coating is reduced, which has an adverse effect on the drying property. Those with a length of 80 m or more are not preferable because of poor dispersibility.

The resin emulsion according to the present invention includes a monomer having a lipophilic group and a monomer having a hydrophilic group. Resin emulsion prepared by emulsifying and copolymerizing a monomer with acrylic resin, specific examples include acrylic resin-based emulsion, urethane resin-based emulsion, polyester resin-based emulsion, and styrene. There are butyl acetate-based resin emulsion, butyl acetate-acrylic copolymer-based resin emulsion, vinyl acetate-powder copolymerized resin-based emulsion, and the like.

[0012] Monomers having a lipophilic group include cyclohexyl (meth) acrylate, methylcyclohexyl (meth) acrylate, t-butylcyclohexyl (meth) acrylate, methyl (meth) acrylate, (meth) Ethyl acrylate, butyl (meth) acrylate, butyl (meth) acrylate, propyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate, (meth) acrylic acid One or more monomers such as benzyl, etc. (meth) acrylic acid esters having an alkyl group with about 11 to 12 carbon atoms, (meth) acrylonitrile, styrene, α-styrene, butyltoluene, vinyl acetate, etc. Is used.

[0013] The hydrophilic group includes a carboxyl group, an alkoxysilyl group, an amino group, a hydroxyl group and the like, and one or more monomers having these can be selected and used.

[0014] Examples of the monomer containing a carboxyl group include acrylic acid, methacrylic acid, maleic acid, itaconic acid, 2-atalyloylethyl succinic acid, and the like.

[0015] Monomers containing an alkoxysilyl group include γ-trimethoxysilylpropyl (meth) acrylate, γ-methyldimethoxysilylpropyl (meth) acrylate, γ-triethoxysilylpropyl (meth) acrylate, Bullmethoxysilane, bullettrimethoxysilane and the like can be mentioned. In addition, the alkoxysilyl group is hydrolyzable, and hydrophilicity can be obtained even in the state of the appeared hydroxyl group.

[0016] The amino group-containing monomers include dimethylaminoethyl (meth) acrylate, dimethylaminopropyl (meth) acrylate, t-butylaminoethyl (meth) acrylate, and monomethylaminoethyl (meth) acrylate. , (Meth) acrylamide, itaconic amide, dimethylamino (meth) propylacrylamide, dimethylaminoethyl (meth) acrylamide, N-methoxymethylacrylamide, N-ethoxymethyl (meth) acrylamide, N-methoxymethyl (meth TA) acrylamide, N-butoxymethyl (meth) acrylamide and the like.

[0017] Monomers containing a hydroxyl group include 2-hydroxyethyl (meth) acrylate and (meth) acrylic acid. 2-hydroxypropyl acid, 4-hydroxybutyl (meth) acrylate, polyethylene glycol mono (meth) acrylate, polypropylene glycol mono (meth) acrylate, cycloheximimethanol mono (meth) acrylate, and the like.

[0018] In the synthesis of these resin emulsions, about 0.5 to 20% by weight of a protective colloid or a surfactant was added to the total amount of the selected monomers and the total amount of water approximately equal to this. In this state, it can be synthesized by a method according to a known emulsion copolymerization.

好ましい The preferred properties of the fat emulsion are as follows: fat solid content: 40-60% by weight;

2—lPa 'sZ25 ° C, no problem if it does not deviate from this property value! /.

[0019] The mixing ratio of silver powder or Z and silver-coated copper powder to the resin emulsion is 100 to 380 parts by weight or more with respect to 100 parts by weight of the resin solid content of the resin emulsion.

If the amount is less than 100 parts by weight, the object of the present invention cannot be achieved because electromagnetic wave shielding properties cannot be obtained. If the amount is more than 380 parts by weight, the fluidity of the coating material is reduced, which causes problems in coating properties and coating finish properties, which is not suitable.

[0020] In order to finish as an electromagnetic wave shielding water-based paint, a compounding material such as a water-soluble solvent or alcohol, a preservative, an ultraviolet absorber, an antioxidant, a filler, a viscosity modifier, and a non-sagging agent is appropriately added.

Fillers of various particle sizes, such as calcium carbonate, alumina, silica sand, clay, and kaolin, are used for the purpose of improving coating film drying properties by adjusting viscosity, cost, and water content, and imparting designability. .

Water-soluble solvents and alcohols are used for viscosity adjustment, cost adjustment, and coating film drying property adjustment. Specifically, water-soluble solvents such as glycol, ethyl ester solvent, daricol ester, propylene glycol monomethyl ether, N-methyl-2-pyrrolidone, and alcohols such as methanol, ethanol, isopropyl alcohol, _n -propanol, and n- Butanol, isobutanol and the like are used.

[0021] The viscosity modifier is preferably used as a paint, and is blended to adjust the viscosity, and one that does not adversely affect the resin emulsion is used.

Specific examples include hydroxyethyl cellulose, methyl cellulose, carboxy cellulose. , Gum arabic, guar gum, dextrin, galactan, pullulan, polyvinylpyrrolidone, polyvinyl alcohol, and the like can be added in appropriate amounts.

[0022] The anti-dripping agent is compounded to prevent dripping at the time of application of the paint, and specific examples thereof include powdered silica and the like, and the compounding amount is selected in consideration of the properties of the paint. .

[0023] The housing according to the present invention is for housing one or a plurality of molded bodies or various electronic components, and is made of a resin material such as ABS resin, polystyrene resin, or polycarbonate resin. I have.

[0024] The coating of the electromagnetic wave shielding aqueous coating according to the present invention, the spray to the inner wall of the housing, is 20- 300gZm ² applied by brush of any coating means.

In the case where adhesion to the casing is expected to lack,榭脂content 5GZm ² about fine amounts applied and urethane榭脂primer one-component moisture-cure type 20 wt% or less榭脂min Can be applied to improve the adhesion.

[0025] Since the electromagnetic wave shielding water-based paint according to the present invention exhibits a bluish green color which is the color tone of silver powder or Z and silver-coated copper powder, when the bluish green color tone is not appropriate, the electromagnetic wave shielding paint of the present invention is used. After applying and drying, it is better to apply the appropriate color top coat to finish.

The finish of the top coat paint may be water-based, for example, a resin emulsion paint prepared by blending fillers, pigments, etc. with the various resin emulsions described above, as well as commonly used known paints. Various oil-based paints can be applied by applying means such as brush or spray.

[0026] In addition, when the silver powder or Z and the silver-coated copper powder are oxidized, the electromagnetic wave shielding performance tends to be remarkably deteriorated. The reason why the electromagnetic wave shielding aqueous paint according to the present invention is not necessarily clear. However, since silver powder or Z and silver-coated copper powder are in a state of coordinating or adsorbing to the hydrophilic group of the monomer having a hydrophilic group disposed outside the resin emulsion, silver powder or Z and silver It is assumed that the coating copper powder was prevented from being oxidized and the electromagnetic wave shielding performance was not reduced.

[0027] Further, silver powder or Z and silver-coated copper powder are compounded in the factor of good releasability from the molded article used for the housing, so that the adhesion of the resin component of the resin emulsion is high. Sex is controlled As a result, it is inferred that appropriate peelability is obtained.

Example

Hereinafter, the present invention will be further described with reference to Examples and Comparative Examples. The amounts in the table are parts by weight. Of course, the present invention is not limited to Examples and Comparative Examples.

Example 11

[0029] A scaly silver powder (manufactured by Fukuda Metal Foil & Powder Co., Ltd., product number AGC-A, average particle size 3 10 m), flaky silver-coated copper powder (manufactured by Fukuda Metal Foil & Powder Industry Co., Ltd., product number 8% Ag coated 2L3 H, average particle size 31 m), dendritic silver-coated copper powder (Fukuda Metal Foil & Powder Industry Co., Ltd.) , A 10% Ag-coated CEE-1110, average particle size of 12 m), etc. were blended and kneaded to prepare an electromagnetic shielding water-based paint of each Example. Immediately after applying the electromagnetic wave shielding paint according to the method described in the section of measurement of volume resistivity below and during the acid oxidation promotion test CFISK5600—7-2Z5 (0 ° C, 95% RH, constant temperature and humidity). Tables 1 and 2 show the volume resistivity after 10 days and 30 days. Table 4 shows the shielding performance of electric and magnetic fields after the oxidation promotion test. Table 6 also shows the adhesion test, re-peeling test, and environmental test for various plastics.

Comparative Example 1

[0030] The solvent-based electromagnetic wave shielding paint prepared by blending the flaky silver powder, acrylic resin, toluene, methyl ethyl ketone, and xylene used in Example 1 was used in the volume resistivity measurement column described below. Tables 3, 5 and 5 show the results of measurements of the coating and volume resistivity, the shielding performance against electric and magnetic fields after the oxidation promotion test, the adhesion test for various plastics, the re-peelability test, and the environmental test. Item 8

Comparative Example 2

[0031] The solvent-based electromagnetic wave shielding paint prepared by blending the flaky silver-coated copper powder, acrylic resin, ethyl acetate and isobutanol used in Example 2 is described in the column of Measurement of Volume Resistivity below. Tables 3, 5, and 8 show the results of measurements of the coating and volume resistivity, the electric field and magnetic field shielding performance after the oxidation promotion test, and the adhesion test, re-peelability test, and environmental test for various plastics. Described. Comparative Example 3

[0032] A scaly copper powder (manufactured by Fukuda Metal Foil Powder Industry, product number 3L3, average particle diameter 13 .: Lm) was blended with the acrylic resin emulsion used in Example 6, kneaded, and mixed with electromagnetic wave shielding water. After preparing a system paint, apply it by the method described in the column of volume resistivity measurement below, apply the volume resistivity, conduct the oxidation promotion test, shield the electric field and magnetic field, and adhere to the various plastics. The results of the burring test and environmental test are listed in Tables 3, 5, and 8 on our own.

Comparative Example 4

The acrylic silver emulsion used in Example 6 was mixed with spherical silver powder (manufactured by Fukuda Metal Foil Powder Co., Ltd., product number: Ag-HWQ63-10, average particle size: 27 m), kneaded, and mixed with an electromagnetic wave filter. Prepare a coated water-based paint, apply it by the method described in the column of volume resistivity measurement below, apply the volume resistivity, conduct an oxidation promotion test, and shield the electric and magnetic fields. Tables 3-5 and 8 [7 here] show the results of the peeling test and environmental test.

Comparative Example 5

[0034] Spherical silver-coated copper powder (manufactured by Fukuda Metal Foil Powder Co., Ltd., product number Ag-coated SRC-Cu-15, average particle size 11 / zm) was mixed and kneaded with the acrylic resin emulsion used in Example 6. Then, prepare an electromagnetic wave shielding water-based paint, apply it by the method described in the column of volume resistivity measurement below, apply the volume resistivity, conduct an oxidation acceleration test, and perform shielding tests for electric and magnetic fields, and for various plastics. Tables 3, 5, and 8 show the results of measurements of the adhesion test, re-peelability test, and environmental test.

Comparative Example 6

[0035] Spherical copper powder (manufactured by Fukuda Metal Foil Kogyo Co., Ltd., product number: EFC-6000, average particle size 2.2-2.8 m) was compounded and kneaded with the acrylic resin emulsion used in Example 6. Prepare an electromagnetic wave shielding water-based paint and apply it according to the method described in the section on volume resistivity measurement below, and perform a volume resistivity test, an oxidation promotion test, and a shield performance for electric and magnetic fields and adhesion to various plastics. Tables 3, 5, and 8 show the results of the tests, re-peelability tests, and environmental tests. Comparative Example 7

[0036] An electromagnetic wave shielding paint prepared by mixing and kneading the flaky silver powder used in Example 1 with each of the acrylic resin emulsion emulsion-copolymerized in the formulation shown in Comparative Example 7 in Table 3 was used. It is applied according to the method described in the column of volume resistivity measurement below, and is subjected to volume resistivity, oxidation acceleration test, electric and magnetic field shielding performance, adhesion test to various plastics, re-peelability test, environmental test Comparative Example 8 in which the results of measurements were described in Tables 3, 5, and 8.

[0037] An electromagnetic wave shield prepared by mixing and kneading the flaky silver-coated copper powder used in Example 2 with each of the acrylic resin emulsions emulsion-copolymerized in the formulation shown in Comparative Example 8 in Table 3 The paint is applied according to the method described in the section on volume resistivity measurement below and subjected to volume resistivity, oxidation promotion test, electric and magnetic field shielding performance, and adhesion test and re-peelability test for various plastics. Tables 3, 5, and 8 show the results of measurements for environmental tests.

Comparative Example 9

[0038] Chain nickel powder (manufactured by INCO, part number NP, average particle size 2.5 m) was blended with each of the acrylic resin emulsions emulsion-copolymerized with the blend shown in Comparative Example 9 in Table 3. The electromagnetic wave shielding water-based paint adjusted by mixing and kneading is applied according to the method described in the column for measuring the volume resistivity below, and the volume resistivity, the electric field and magnetic field shielding performance after the oxidation acceleration test, and various Tables 3, 5, and 8 show the measurement results of the adhesion test, re-peelability test, and environmental test for plastics.

Tables 1, 2 and 3 show the properties of the conductive paints prepared according to the examples and comparative examples, and the measurement results of the volume resistivity immediately after and at the end of the test period of 10 days and 30 days in the oxidation acceleration test. It was as follows. In Table 3, despite the low volume resistivity of Comparative Examples 1 and 2 after the acidification promotion test, the shield performance value in Table 5 was low because the coating film was hard and cracks occurred. It is inferred.

In Tables 1, 2 and 3, methyl methacrylate is MMA, methacrylic acid is MAA, butyl methacrylate is MAB, cyclohexyl methacrylate is MAC, and 2-Ethylhexyl acrylate is indicated by 2EHA, 2-hydroxyethyl acrylate is indicated by 2HEA, butyl acrylate is indicated by BA, styrene is indicated by ST, and butyltrimethoxysilane is indicated by VTMS.

[table 1]

Note units of Z viscosity Pa. S / 25 ° C, the unit of volume resistivity referred to Ωπι volume resistivity 5.1X10- ⁶ 5. lexp and (-6).

[Table 2]

Detailed

10 11 12 13 14 15 16

MMA 25 25 20 25 25 25 25 ΛΒ 35 30 20 15 30 35 35

MAC ⁰ 10 15 58 40 35 10 10

ST

2EHA 10 10 10 10

2HEA ^ 20 5 AA 20 20 20 v

VTMS 20 2 5

Water 30 30 30 30 30 30 30 Ethanol 70 35 70 70 70 50

IPA 70 35

20 t. n de :; 1 δ g flake powder 100 50 50 500 CO a (n-contact) ^

100 50 50

100 50 50 50

SO-G SB powder

300 300 300 300 300 300 300

6 & .6 6 & 6 66- 6 66.6 66.6 66.6 66.6 Viscosity P¾rs 4--8 3.8 4.2 4.8 3--9 3.2 3.3

«Reward rate ϋ 5.0 6.0 4.7

exp exp οφ

(ftm> (-6) <-6) (-6)

4.2 4.5 4.5 exp οφ οφ

(-6) (-6) (-6) Same as above 4.2 5.9 4.6

30 days later exp exp οφ

(-6) (-6) (-6) Note units of Z viscosity Pa. S / 25 ° C, the unit of volume resistivity referred to Ωπι volume resistivity 5.1X10- ⁶ 5. lexp and (-6).

[Table 3]

Comparative example

1 2 3 4 5 6 7 8 9 A 20 20 20 20 25 25 20

Mfi 20 20 20 20 25 25 20

MAC 10 10 10 10 10

BA 10

ST 20 20 20 20 20 20 20

2EHA 10 10 10 10 10 ΙΟ 10 10

2HEA 10 10 10 10 10 10 10 AA TWS 10 10 10 10 10 10 10 water 100 100 100 100 100 100 100 torr! 60

To MEK 26

Xylene 4

to βίΚΐ chill 80

Iributane 10

Powder 100 100

100 100 g piece 100

Powder 100

100

Spherical copper powder 100

100 Total 200 200 300 300 300 300 300 300 300 Solid ^ 55 55 55 66.6 66.6 6 & 6 66.6 66.6 6 & 6 6 & 6 Sticky Sa-s 1-3 1-2 7.4 5.8 5.7 5.2 7.2 7.4 7.7

«¾S¾t apple 5.1 8.8 2.5 5.8 8.0 6.0 5.3 7.2 2.5

(Bas ecp e <p βφ exp («m> (1-6) (2) <1-6) (-4) Same as above 5.8 8.7 4.3 e.5 8.1 5.8 1.8 4.0 4.3

After 10B e <p ecp & <p β <ρ exp exp exp exp

(«M) (-6) (-6) <-2) (3) (-4) (-3) Same as above 5.9 8.8 2.1 6.4 8.0 3.8 4.3 9.2 2.1

30th raft θρ exp

(-1) <4) (1-2) Note Z viscosity is in Pa.s / 25 ° C, volume resistivity is in Ωπι

The volume resistivity 5. 1X10- ⁶ 5. referred to lexp (-6). [Table 4]

Note Z Electric and magnetic field attenuation Unit: dB

“One” in the table is beyond the measurement limit (65 dB or more). [0044] [Table 5]

Note Z Electric and magnetic field attenuation Unit: dB

[Table 6] Detailed

^ ttov 1 2 3 4 5 6 7 8 9 Body arrest 5.8 7.2 exp

<nm)

(— 6> (-6)

ABS 10/10 10/10 10/10 10/10 10/10 10/10 1Ο / Ί0 10/10 10/10

PS 3/10 4/10 3/10 5/10 4/10 3/10 4/10 3/10 4/10

PP 0/10 0 / g1.O0 0/10 0/10 0/10 0/10 0/10 o / io 0/10 jfiBS o o o0 (ft f o o o O O O

PS o o o o o o O o o

PP © <s> <§> ® fiBS o o O o o Θ (0- o o o o o

DI 1 ^δ

PS o o O O o o o o o o

PP O o O O O O o o o

o a t

ABS O o O O O O o o o

PS O O O O O O O O O

Trial

9t PP O O O O O O O O O

ABS: acrylonitrile 'butadiene' styrene copolymer resin, PS: polystyrene resin, PP polypropylene resin

Note volume resistivity 5.1X10- ⁶ 5. lexp - referred to as (6).

[Table 7] Examples

10 1 1 12 1 3 1 15 16

5.0 4.3 6.0 4.7

Body contact resistivity

exp

(-6) (-6) (-6) <-6)

ABS 1 V, '0/10 10/10 10/10 10/10 10/10 10/10 10/10

PS 3/10 4/10 3/10 5/10 4/10 3/10 3/10

PP 0/10 0/10 0/10 0/10 0/10 0/10 0/10

ABS o O O o o O o

PS o o o o o o o

PP <§> <s> <s>

ABS o o o o o o o

Ό

Return PS o o o O O o o

Trial

PP o O o O O o ^> Dimension O

PBS O O o O O o O

PS O O O O O O O

PP O O O O O O O

ABS: acrylonitrile 'butadiene' styrene copolymer resin, PS: polystyrene resin, PP: polypropylene resin

Note volume resistivity 5.1X10- ⁶ 5. lexp - referred to as (6).

Faction Comparative example

ϊβ «ttDv 1 2 3 4 5 6 7 8 9

6.0 2-5 Body Stt rate

(2) (-4) fi S 10/10 1Ο / 10 10/10 10/10 10/10 10/10 ιο / ιο 10/10 10/10

PS 3/10 2/10 3/10 5/10 4/10 3/10 3/10 3/10 3/10 ώ

PP 0/10 0 / to »1 ∞0 0/10 0/10 0/10 0/10 0/10 0/10 0/10

,,

ABS X X ο ο ο ο ο ο ο ο

PS XX ο Ιίί ^δ ο ο ο ο ο ο ο

PP Δ Θ <® <§> <§> ®

Ding

rp ABS

ik ο ο ο ο ο ο ο ο ο ο iek

Return PS ο ο ο ο ο ο ο ο ο ο ο

PP X X ο ο ο ο ο ο ο ο

Re3 ABS ο ο ο ο ο ο ο ο ο ο f = l

PS ο ο ο ο ο ο ο ο ο ο Trial

9t PP X X ο ο ο ο ο ο ο ο

ABS: acrylonitrile 'butadiene' styrene copolymer resin, PS: polystyrene resin, ΡΡ: polypropylene resin

Note volume resistivity 5. 1X10- ⁶ 5. lexp - referred to as (6).

Test evaluation method

1.Volume resistivity

After coating with a doctor blade (coating groove depth of 100 μm) on a 150 μm thick polypropylene resin film and forming a film, and after 5 hours, 4 surface resistance value by the probe method Is measured, and the volume resistivity (Ωπι) is calculated from the film thickness.

In addition, in the acid-riding promotion test (JISK5600-7-2Ζ, measured after leaving it in a thermo-hygrostat at a humidity of 95% RH and a temperature of 50 ° C) for a period of 10 Measure the rate (Ω πι).

2.Electromagnetic wave shielding performance

Electric field ΖAdvantest method (place a small monopole antenna at the counter electrode and measure the transmission loss when a sample is inserted, with the sample inserted as a reference).

Magnetic field による Advantest method (place a small loop antenna at the opposite electrode, do not insert the sample! Measure the transmission loss when the sample is inserted using the state as a reference).

3.Adhesion test

After coating on various plastic substrates with a doctor plate (coating groove depth 100 μm), forming a film, drying at room temperature for 5 hours, curing for 24 hours, and measuring according to JIS-5600-5-6 I do.

4.Removability test

After coating on various plastic substrates with a doctor plate (coating groove depth 100 μm), forming a film, drying at room temperature for 5 hours, curing for 24 hours, then spray-coating the film with methanol to stain. After that, perform manual stripping and confirm the ease of stripping again. ◎: The film can be easily peeled off without breaking, 〇: 5 to 50% of the film breaks but can be easily peeled off, △: The film which breaks more than 50% can be peeled off, X: The film cannot be peeled off Possible.

5.Durability test

After coating on a plastic substrate with a doctor plate (coating groove depth 100 μm) to form a film, dry at room temperature for 5 hours, cure for 24 hours, and test under the following conditions (a or mouth). Place the test specimen and observe appearance defects such as peeling and swelling.

〇: Good without peeling or swelling. X: Peeling or swelling occurred

B. Cold and hot cycle test (JIS-K5600—7-4)

(18 hours at 23 ° C → 3 hours at 20 ° C → 3 hours at 50 ° C) Repeat the test for 10 cycles, and observe the peeling and swelling.

Mouth.High temperature / high humidity test (JIS—K5600—7—2)

After leaving for 500 hours in an environment of 50 ° C and 95% RH, observe the appearance of peeling, blistering, etc.

Industrial applicability The electromagnetic wave shielding water-based paint according to the present invention is free from various problems such as health and disaster prevention due to the volatilization of the solvent and has excellent electromagnetic wave shielding performance. Because of its good releasability, it is convenient to recycle the materials used for the housing, so it can be widely used in the fields of various electronic devices that generate electromagnetic waves, electric devices, power devices, control system devices, etc. .

Claims

The scope of the claims

[1] An electromagnetic wave shielding water-based paint, characterized in that silver powder or Z and silver-coated copper powder are mixed with a resin emulsion and prepared.

2. The electromagnetic wave shielding water-based paint according to claim 1, wherein the silver powder is scaly and the silver-coated copper powder is dendritic or scaly.

3. The electromagnetic wave shielding water system according to claim 1, wherein a resin emulsion obtained by emulsion-copolymerization using a monomer having a lipophilic group and a monomer having a hydrophilic group is used. paint.

4. The electromagnetic wave shielding water-based paint according to claim 13, wherein cyclohexyl (meth) acrylate is used as the monomer having a lipophilic group.

[5] The electromagnetic wave shielding water-based paint according to any one of [14] to [14], wherein a resin emulsion prepared by coordinating a hydrophilic group of a monomer having a hydrophilic group to the outside is used.

[6] The electromagnetic wave shielding water-based paint according to any one of [15] to [15], which is of a re-peeled type.

[7] A housing, characterized by being coated with an electromagnetic shielding water-based paint prepared by mixing silver powder or Z and silver-coated copper powder with a resin emulsion.

[8] The casing according to claim 7, wherein an electromagnetic wave shielding water-based coating is used in which the silver powder is scaly and the silver-coated copper powder is dendritic or scaly.

[9] The electromagnetic wave shielding water-based paint using a resin emulsion obtained by emulsion-copolymerization using a monomer having a lipophilic group and a monomer having a hydrophilic group is applied. The housing according to any one of 7 to 8.

[10] The re-stripping type electromagnetic wave shielding water-based paint is applied.

A housing according to any one of 7 to 9.