KR20210084219A - Electromagnetic wave shielding binder resin, electromagnetic wave shielding coating composition comprising the same, electromagnetic wave shieding film formed using the same - Google Patents

Abstract

The present invention relates to a binder resin for electromagnetic wave shielding, an electromagnetic wave shielding coating composition including the same, and an electromagnetic wave shielding film formed using the same. Specifically, the present invention relates to a polymer binder resin for electromagnetic wave shielding using an acrylic polymer, an electromagnetic wave shielding coating composition including the same, and an electromagnetic wave shielding film formed using the same, wherein the polymer binder resin has excellent weather resistance, facilitates synthesis and handling, has low yellowing degree, provides excellent oxidation stability, and can be easily modified by changing a polymer composition or introducing a functional group according to necessary physical properties.

Description

Electromagnetic wave shielding binder resin, electromagnetic wave shielding coating composition comprising same, and electromagnetic wave shielding film formed using the same

The present invention relates to a binder resin for electromagnetic wave shielding, an electromagnetic wave shielding coating composition comprising the same, and an electromagnetic wave shielding film formed using the same. Specifically, a binder for electromagnetic wave shielding using an acrylic polymer that has excellent weather resistance, is easy to synthesize and handle, has a low degree of yellowing, has excellent oxidation stability, and is easy to modify by changing the polymer composition or introducing a functional group according to the required physical properties. It relates to a resin, an electromagnetic wave shielding coating composition comprising the same, and an electromagnetic wave shielding film formed using the same.

Conventional EMI shielding was implemented using the sputtering method among physical vapor deposition (PVD) technologies. That is, the electromagnetic wave shielding film was formed by sputtering, which is one of the physical vapor deposition (PVD) processes for forming a thin film on a chip in a physical manner.

The electromagnetic interference shielding technology by sputtering has a problem in that the cost increase burden is large, and the device becomes thick because of the circuit for blocking electromagnetic electromagnetic interference, which is an obstacle to miniaturization and thin film.

In order to improve this, technology development for improving shielding efficiency and simplifying the production process while thinning the shielding layer by using a spray coating method or the like has recently been made.

The spray method can control the spray angle, apply materials evenly to all surfaces of semiconductors or parts, and can meticulously block high and low frequencies leaking from the side compared to the conventional shielding method.

The spray shielding method is a technology that covers the shielding film by vertically spraying the sticky shielding material paste on the product. The biggest advantage is that the chip volume can be reduced. In addition, it is characterized by being able to cover the sides with an elaborate membrane using artificial wind, etc. Also, the process is simple and the cost is low.

Polyurethane binder is mainly used in the existing spray method, but there are problems such as poor transparency and yellowing. There is a need for research and development of a composition for spraying.

In addition, the conventional electromagnetic shielding binders have a high contact angle with respect to ethylene glycol, so when there are many curvatures or irregularities on the surface of circuits or precision base devices, the thickness of the protruding part and the recessed part are different, which may cause machine failure. Dispersion stone for electromagnetic wave shielding particles such as , silver particles is inferior, and also causes circuit failure due to insufficient adhesion to the electromagnetic wave shielding target base or circuit (cross-cut test).

In addition, the role of suppressing the increase in resistance by further lowering the electrical conductivity by combining with the electromagnetic wave shielding particles is still insufficient, and the surface hardness is poor when coated. Therefore, there is a need to develop a new electromagnetic wave shielding binder that satisfies the new physical properties, that is, the physical properties to further improve it.

Korean Patent Publication No. 10-1000973 (2010.12.07.)

One object of the present invention is to provide a binder resin capable of electromagnetic wave shielding, and an electromagnetic wave shielding coating composition comprising the same.

In particular, the present invention has excellent pencil hardness, low yellowness, low electrical conductivity, non-sticky discharge to the nozzle during spray coating, excellent discharge property that does not block the nozzle, and low contact angle to ethylene glycol, so that it is suitable for substrates such as electronic circuits. A new binder resin for electromagnetic wave shielding, which imparts surface properties to be coated with a uniform thickness regardless of curvature, has excellent dispersibility of electromagnetic wave shielding material, and has excellent adhesion properties in cross-cut evaluation related to adhesion to coated large substrates To provide an electromagnetic wave shielding coating composition used.

More specifically, the present invention has excellent surface properties with excellent pencil hardness of 3H or more, yellowness of 10 or less, electrical conductivity of 100 (mΩ/10㎛) or less, spray discharging property, and contact angle with ethylene glycol of 40 or less. It is to provide a novel electromagnetic wave shielding binder resin and an electromagnetic wave shielding coating composition using the same, which has 4B or higher properties in cross-cut evaluation related to dispersibility and adhesion.

As a result of many studies to achieve the above object, the electromagnetic wave shielding binder of the present invention is (a) methyl methacrylate (MMA), (b) (C3-C7) alkyl (meth) acrylate, (c) hydride At least one monomer selected from hydroxyalkyl (C2-C4) (meth) acrylate or a condensed monomer of a saturated diacid compound and hydroxy (C3-C4) alkyl (meth) acrylate; and (d) cycloalkyl (meth) acryl It may be a polymerized binder resin for electromagnetic wave shielding, including any one or more monomers selected from late, styrene, and benzyl (meth)acrylate.

In the present invention, the yellowness of the binder resin for electromagnetic wave shielding may be 5 or less, and the contact angle with respect to ethylene glycol may be 40 or less.

In the present invention, the saturated diacid compound may be any one or more selected from succinic acid, malic acid, adipic acid, and glutaric acid.

As an example of the binder resin for electromagnetic wave shielding of the present invention, without limitation, any one or more selected from the following Chemical Formulas 1 to 4 may be a resin.

[Formula 1]

[Formula 2]

[Formula 3]

[Formula 4]

The present invention may also provide an electromagnetic wave shielding coating composition comprising the electromagnetic wave shielding binder resin, an electromagnetic wave shielding compound, and a diluent.

In the present invention, the electromagnetic wave shielding compound may include any one or more components selected from metal particles, metal salts, conductive polymers, carbon particles, carbon tubes, carbon nanotubes, graphene, and graphene oxide.

In the present invention, the coating composition may be an electromagnetic wave shielding coating composition comprising 10 to 70 wt% of the electromagnetic wave shielding compound, 5 to 50 wt% of the electromagnetic wave shielding binder resin, and 20 to 80 wt% of a diluent.

In addition, the present invention can provide an electromagnetic wave shielding film formed by coating using the electromagnetic wave shielding coating composition of the various aspects.

In the present invention, the electromagnetic shielding film may be an electromagnetic shielding film having a pencil hardness of 3H or more, an electrical conductivity of 100mΩ/10㎛ or less, and a crosscut 4B or more.

In one aspect of the present invention, the acrylic resin as the binder of the present invention may have a decomposition temperature of 200° C. or higher and a weight average molecular weight of 100,000 g/mol or higher.

The binder resin capable of shielding electromagnetic waves according to the present invention has excellent transparency, low yellowing, excellent ejection properties, excellent coating properties and adhesion to the EMC substrate, which is a substrate, and has high surface hardness. It is possible to provide an effect that satisfies all of the physical properties.

Specifically, the present invention relates to a binder resin for electromagnetic wave shielding having a contact angle of 40 degrees or less using ethylene glycol.

In one aspect of the present invention, the binder resin may have a pencil hardness of 3H or more.

In one aspect of the present invention, the binder resin may have a yellowness of 5 or less according to ASTM E313.

In addition, according to an aspect of the present invention, it may have an electrical conductivity of 100 (mΩ/10㎛) or less, has excellent spray discharge properties, has excellent surface properties with a contact angle to ethylene glycol of 40 or less, and has excellent dispersibility. It may be a novel electromagnetic wave shielding binder resin having a characteristic of 4B or higher in cross-cut evaluation related to adhesion and an electromagnetic wave shielding coating composition using the same.

1 shows the results of 1H-NMR analysis of polymers prepared in Examples.

Hereinafter, the present invention will be described in more detail through embodiments or examples including the accompanying drawings. However, the following specific examples or examples are only a reference for describing the present invention in detail, and the present invention is not limited thereto, and may be implemented in various forms.

Also, unless defined otherwise, all technical and scientific terms have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used in the description herein is for the purpose of effectively describing particular embodiments only and is not intended to limit the invention.

Also, the singular forms used in the specification and appended claims may also be intended to include the plural forms unless the context specifically dictates otherwise.

In addition, when a part "includes" a certain component, this means that other components may be further included rather than excluding other components unless otherwise stated.

Hereinafter, the present invention will be described in more detail based on Examples and Comparative Examples. However, the following Examples and Comparative Examples are merely examples for explaining the present invention in more detail, and the present invention is not limited by the following Examples and Comparative Examples.

In one aspect of the present invention, the electronic shielding binder of the present invention may be an acrylic resin prepared from a composition of the following monomers.

The acrylic resin of the present invention is (a) methyl methacrylate (MMA), (b) (C3-C7) alkyl (meth) acrylate, (c) hydroxyalkyl (C2-C4) (meth) acrylate or At least one monomer selected from a catalyst monomer of saturated diacid or saturated diacid anhydride and hydroxyalkyl (meth)acrylate, and (d) any one selected from cycloalkyl (meth)acrylate, styrene and benzyl (meth)acrylate It may be polymerized including more than one monomer of

In the present invention, as the term (meth)acrylate, it is used in the sense that it may be methacrylate or acrylate.

As the acrylic resin employed as the binder of the present invention, (b) (C3-C7) alkyl (meth) acrylate is propyl methacrylate, propyl acrylate, isobutyl acrylate, isobutyl methacrylate, and normal butyl methacrylate. rate. Normal butyl acrylate, pentyl acrylate, normal hexyl acrylate, and various alkyl (meth) acrylates falling into the above categories such as isomers, normal peptyl acrylate and isomers thereof can be exemplified. Among them, in order to satisfy various properties desired by the present invention, such as coating property, adhesive property, surface hardness, and dispersibility, normal butyl acrylate is more preferred, but not limited thereto.

The following (c) at least one monomer selected from hydroxyalkyl (C2-C4) (meth) acrylate or a catalyst monomer of saturated diacid or saturated diacid anhydride and hydroxyalkyl (meth) acrylate is 2-hydroxyethyl It includes acrylate, 2-hydroxymethacrylate, hydroxypropyl acrylate, hydroxypropyl methacrylate, hydroxybutyl acrylate and various isomers thereof, and is not particularly limited as long as it belongs to the above chemical structure. In the case of hydroxyacrylate, hydroxyethyl acrylate is more preferred, but not limited thereto.

In the case of hydroxyalkyl (meth)acrylate and saturated diacid, examples of the saturated diacid are not particularly limited, but for example, if it is a saturated diacid such as succinic acid, malic acid, adipic acid, glutaric acid, it is not limited. , preferably the above succinic acid, malic acid, adipic acid, and glutaric acid, and more preferably succinic acid, which can achieve the physical properties of the present invention well. The reaction between the hydroxyalkyl (meth)acrylate and the saturated diacid may be prepared by dehydration using various methods such as an acid or a base reaction, and thus will not be described further herein. In addition, commercialized monomers can be purchased and used.

Next, (d) cycloalkyl (meth)acrylate is described. Examples of the cycloaliphatic cyclo group include those having an alicyclic functional group such as cyclobutyl, cyclopentyl, cyclohexyl, and cyclohexyl, but are not necessarily limited thereto. No, preferably cyclohexyl acrylate, but not limited thereto.

The molar ratio of the monomers (a) to (d) described above may be 1:0.1:0.1:0.1 to 1:0.9:0.9:0.9. The molar ratio of the monomers (a):(b):(c):(d) may be 1:0.1:0.1:0.1 to 1:0.9:0.9:0.9. and preferably 1:0.3:0.3:0.3 to 1:0.7:0.7:0.7, more preferably 1:0.4:0.4:0.4 to 1:0.6:0.6:0.6, but is not limited thereto.

If an example of the electromagnetic wave shielding binder of the present invention is given, it may include any one or more selected from the following Chemical Formulas 1 to 4, but is not limited thereto as long as it is included in the aspect of the present invention.

[Formula 1]

[MBHSt]

[MBHSt]

[Formula 2]

[MBHBen]

[MBHBen]

[Formula 3]

[MBHCa]

[MBHCa]

[Formula 4]

[MBHCa(HEA)]

[MBHCa(HEA)]

The present invention may also provide a coating composition for electromagnetic shielding comprising the binder for electromagnetic shielding of the present invention, and it may also be an aspect of the present invention to provide an electromagnetic shielding film using the composition.

In one aspect of the present invention, the electromagnetic wave shielding coating composition may include an electromagnetic wave shielding or electromagnetic wave absorbing compound or particles.

The electromagnetic wave shielding or electromagnetic wave absorbing compound or particle of the present invention may be various selected from metal particles, metal salt particles, conductive polymers, etc., for example, silver particles, gold particles, carbon particles, carbon tubes or carbon nanotubes, graphene Pin, graphene oxide, etc. can be used, and if it can impart an electromagnetic wave shielding effect, it is not particularly limited. The size of the particles is not particularly limited, but preferably 5 nm to 20 μm, preferably 10 nm to 2 μm, but is not limited thereto, and silver particles or silver nanoparticles may be preferably used.

In addition, the electromagnetic shielding coating composition of the present invention may further include a diluent or dispersion medium. The dispersion medium is not limited as long as it dissolves the binder and can dissolve the conductive polymer when the electromagnetic wave shielding compound is a conductive polymer, and it is not limited as long as it disperses particles such as the metal particles or carbon particles.

For example, various diluents or solvents such as acetone, ester, ketone, ether, and alkylene glycol may be used.

In addition, the composition ratio of the electromagnetic shielding coating composition of the present invention is not particularly limited, but for example, the electromagnetic shielding agent including the electronic shielding metal particles or conductive polymer, 5 to 50% by weight of the binder of the present invention, and 20 to 80 diluents It may be to provide an electronic shielding composition containing weight %, but it is not limited thereto, and it can be used by adjusting the composition ratio according to the purpose of use.

More specifically, the present invention provides an electronic shielding composition comprising 10 to 70% by weight of an electromagnetic shielding agent containing metal particles or conductive polymer for electronic shielding, 5 to 50% by weight of the binder of the present invention, and 20 to 80% by weight of a diluent may be provided.

Hereinafter, the binder of the present invention will be described in detail through Examples and Comparative Examples of the present invention, and it is those skilled in the art that the binder of the present invention is not limited to the following examples and can be variously changed within the technical spirit of the present invention. of course you can know.

[Examples 1 to 6, Comparative Examples 1 to 2]

It was prepared by continuously adding the same amount of a monomer mixture having the molar ratio of Table 1 to an ethyl acetate solvent twice, and the monomer mixture with respect to the total solvent was polymerized at a concentration of 50% by weight. The initiator was used in an amount of 0.5% by weight based on the total monomer.

The monomer mixture was divided into two portions during the polymerization process, and the initiator was added in three portions.

First, after all of the solvent was added, the temperature of the reactor was raised to 80° C., and 50% by weight of the mixture of each monomer in Table 1 was added over 30 minutes. The content of this initiator was added together with 40 wt% of the total initiator content.

After the addition was completed, 50% by weight of the initiator was mixed together with respect to the remaining 50% by weight of the monomer and the total initiator, and the mixture was added dropwise over 2 hours, followed by polymerization for an additional 1 hour. Then, 10% by weight of the initiator with respect to the remaining total initiator was mixed with 5% by weight of the previously added solvent and additionally added for 30 minutes, the reaction was added and completed for 2 hours and 30 minutes, and after cooling, it was added to an excess of hexane After peroxidation, it was recovered by drying.

(a) (b) (c) (d) MMA
(Unit: mole) BA
(Unit: mole) HEA
(Unit: mole) HEA_suc
(Unit: mole) Ca
(Unit: mole) St
(Unit: mole) Ben
(Unit: mole) Example 1 MBHSt One 0.5 - 0.5 - 0.5 - Example 2 MBHBen One 0.5 - 0.5 - - 0.5 Example 3 MBHCa (HEA) One 0.5 0.5 - 0.5 - - Example 4 MBHCa (0.3) One 0.5 - 0.5 0.3 - - Example 5 MBHCa (0.5) One 0.4 - 0.5 0.5 - - Example 6 MBHCa (0.9) One 0.5 - 0.5 0.9 - - Comparative Example 1 - One 0.5 - 0.5 - - - Comparative Example 2 - One - 0.5 - - 0.5 - MMA: MethylMethacrylate
BA : n-Butyl acrylate
H: HEA_suc: hydroxyethyl acrylate-succinate condensed monomer
HEA: hydroxylehtylacrylate
Ca: Cyclohexylmethacrylate
St: Styrene
Ben: Benzylacrylate

After the synthesis of the recovered examples, structural analysis and physical properties were evaluated.

1 shows the results of 1H-NMR analysis, and the structure was confirmed by examining the characteristic peaks of each polymer.

Table 2 below shows thermal properties such as thermal decomposition temperature by TGA and glass transition temperature by DSC analysis, molecular weight, and molecular weight distribution of the Examples.

TGA
(℃, Td5) DSC
(℃, Tg) GPC Mn
(x10 ⁴ ) Mw
(x10 ⁴ ) PDI Example 1 246.55 34.77 1.06 1.87 1.76 Example 2 251.58 47.99 1.63 2.03 1.25 Example 3 291.80 53.62 6.05 10.8 1.79 Example 4
(Ca0.3) 246.19 36.03 10.0 15.0 1.5 Example 5 281.65 38.95 9.31 17.1 1.84 Example 6
(Ca0.9) 225.03 39.91 9.64 13.7 1.42

Table 3 below shows the measured properties of the binder of the present invention when used as a binder for electromagnetic wave shielding.

pencil ¹⁾
Hardness yellowness
change ²⁾ electrical conductivity ³⁾
(mΩ/10㎛) discharging EG
contact angle ⁴⁾
( ^o ) dispersibility ⁵⁾ cross
cut
evaluation ⁶⁾ Example 1 4H 2.61 75 Great 34.75 ○ 4B Example 2 4H 4.38 75 Great 34.03 ○ 4B Example 3 4H 4.97 100 Great 34.85 ○ 4B Example 4
(Ca0.3) 4H 1.45 100 Great 33.86 ◎ 5B Example 5 4H 1.12 63 Great 32.94 ◎ 5B Example 6
(Ca0.9) 4H 2.67 68 Great 34.01 ◎ 5B Comparative Example 1 2H 8.32 140 thirteen 47.23 ○ 2B Comparative Example 2 3H 11.4 149 thirteen 53.12 X 3B

1) Pencil hardness: Prepared by mixing a mixture for electromagnetic wave shielding (45 wt% of Ag powder filler, 15 wt% of the binder of Examples, and 40 wt% of a diluent (proplene glycol monomethyl ether)), coated on an iron plate, and dried and cured The pencil hardness was measured (ISO 15184).

2) The change in yellowness measured based on ASTM E313 after the substrate was coated using a mixture of the binder and diluent of 20% by weight and aged at 260° C. for 1 hour was measured.

3) Electrical conductivity: After preparing by mixing a mixture for electromagnetic wave shielding (45% by weight of Ag powder filler, 15% by weight of the binder of Examples, and 40% by weight of a diluent (proplene glycol monomethyl ether), dry and harden, then measure the electrical conductivity. was used.

4) After coating the substrate using a mixture of the binder and diluent of 20% by weight and drying and curing, the contact angle with respect to ethylene glycol (EG) was measured using a Contact Angle Goniometer (Model 190).

5) Dispersibility: The dispersibility of Ag particles was relatively measured with TURBISCAN equipment. (Measured by mixing 45% of Ag powder filler, 15% of binder (Example), and 40% of diluent (proplene glycol monomethyl ether))

6) Crosscut evaluation method: After preparing a mixture for electromagnetic wave shielding (Ag powder filler 45%, binder (Example) 15%, diluent (proplene glycol monomethyl ether) 40%, all by weight), it is coated on an iron plate and cured. The cured surface was subjected to a cross-cut adhesion tester (CC1000, manufactured by TQC) to make scratches by crossing lines in a grid pattern, and then the coating state after attaching and peeling the tape was checked. (ASTM D3359)

As described above, the present invention has been described with specific details and limited examples and drawings, but these are only provided to help a more general understanding of the present invention, and the present invention is not limited to the above embodiments, and the present invention is not limited to the above embodiments. Various modifications and variations are possible from these descriptions by those of ordinary skill in the art.

Therefore, the spirit of the present invention should not be limited to the described embodiments, and not only the claims to be described later, but also all those with equivalent or equivalent modifications to the claims will be said to belong to the scope of the spirit of the present invention. .

Claims (10)

(a) methyl methacrylate (MMA), (b) (C3-C7) alkyl (meth) acrylate, (c) hydroxyalkyl (C2-C4) (meth) acrylate or a saturated diacid compound and hydroxy ( C3-C4) Any one or more monomers selected from the condensed monomer of alkyl (meth) acrylate and (d) any one or more monomers selected from cycloalkyl (meth) acrylate, styrene and benzyl (meth) acrylate A polymerized binder resin for electromagnetic wave shielding. The method of claim 1,
The binder resin for electromagnetic wave shielding is a binder resin for electromagnetic wave shielding having a yellowness of 5 or less. The method of claim 1,
The electromagnetic wave shielding binder resin has an electromagnetic wave shielding binder resin having a contact angle with respect to ethylene glycol of 40 or less. The method of claim 1,
Binder resin for electromagnetic wave shielding wherein the saturated diacid compound is at least one selected from succinic acid, malic acid, adipic acid, and glutaric acid The method of claim 1,
The binder resin for electromagnetic wave shielding is a binder resin for electromagnetic wave shielding comprising at least one selected from the following Chemical Formulas 1 to 4.
[Formula 1]

[Formula 2]

[Formula 3]

[Formula 4]

An electromagnetic wave shielding coating composition comprising the electromagnetic wave shielding binder resin of any one of claims 1 to 5, an electromagnetic wave shielding compound, and a diluent. 7. The method of claim 6,
The electromagnetic wave shielding compound is an electromagnetic wave shielding coating composition comprising any one or more components selected from metal particles, metal salts, conductive polymers, carbon particles, carbon tubes, carbon nanotubes, graphene, and graphene oxide. 7. The method of claim 6,
The composition is an electromagnetic wave shielding coating composition comprising 10 to 70 wt% of the electromagnetic wave shielding compound, 5 to 50 wt% of the electromagnetic wave shielding binder resin, and 20 to 80 wt% of a diluent. An electromagnetic wave shielding film formed of the electromagnetic wave coating composition of claim 6. 10. The method of claim 9,
The electromagnetic wave shielding film is an electromagnetic wave shielding film formed of the electromagnetic wave coating composition of claim 6 is an electromagnetic wave shielding film having a pencil hardness of 3H or more, an electrical conductivity of 100mΩ/10㎛ or less, and a crosscut 4B or more.

Images