WO2005118500A1

WO2005118500A1 - Lead-free glass having low melting point

Info

Publication number: WO2005118500A1
Application number: PCT/JP2005/009356
Authority: WO
Inventors: Taishin Shimooka; Naoya Hayakawa
Original assignee: Central Glass Company, Limited
Priority date: 2004-06-02
Filing date: 2005-05-23
Publication date: 2005-12-15
Also published as: TW200602281A; TWI322137B; KR20070009992A

Abstract

A lead-free SiO2-B2O3-ZnO-R2O-CuO based glass having a low melting point (a first glass), which has transparency and insulating property, and comprises, in wt %, 7 to 20 % of SiO2, 32 to 50 % of B2O3, 25 to 42 % of ZnO, 7 to 20 % of R2O (Li2O + Na2O + K2O), 0.1 to 2 % of CuO, and 0 to 10 % of RO (MgO + CaO + SrO + BaO); and a lead-free SiO2-B2O3-ZnO-R2O-CuO based glass having a low melting point (a second glass), which has transparency and insulating property, and comprises, in wt %, 11 to 20 % of SiO2, 45 to 65 % of B2O3, 10 to 20 % of ZnO, 10 to 18 % of R2O (Li2O + Na2O + K2O), and 0.1 to 2 % of CuO.

Description

Specification

Lead-free low melting glass

Technical field

The present invention relates to an electronic material substrate typified by a plasma display panel, a liquid crystal display panel, an electorifice luminescent panel, a fluorescent display panel, an electoral chromic display panel, a light emitting diode display panel, a gas discharge display panel, and the like. And a low-melting glass used as a sealing material.

Background of the Invention

[0002] With the development of electronic components in recent years !, such as plasma display panels, liquid crystal display panels, electorifice luminescent panels, fluorescent display panels, electoric chromic display panels, light emitting diode display panels, gas discharge display panels, etc. Many types of display panels have been developed. Among them, plasma display panels (hereinafter abbreviated as PDPs) are attracting attention as thin and large flat panel color display devices. A PDP has many cells between a front substrate and a rear substrate used as a display surface, and an image is formed by plasma discharge in the cells. This cell is partitioned by partition walls, and an electrode is formed for each pixel in order to control the display state of each pixel forming an image.

[0003] An electrode for discharging plasma is formed on the front glass plate of the plasma display panel, and thin linear silver is often used as the electrode. A highly transparent insulating material is provided around the electrodes. This insulating material is preferably excellent in plasma durability and transparent. For this reason, dielectric glass is often used as an insulating material. In addition, since the dielectric glass is required to have a lower melting point than the glass plate serving as the base in the process, a low melting point glass is used.

[0004] However, in the conventional low melting point dielectric glass, the dielectric glass reacts with silver of the bus electrode at 450 to 600 ° C at low temperature firing, so that the dielectric glass is colored yellow ( (Yellowing) occurred, and high transmittance could not be obtained.

[0005] With respect to the yellowing, various known methods to be solved by adjusting the glass component. Technology exists. SiO, Al O, etc. as essential components, for example, the content of PbO and CuO

2 2 3

The same effect can be obtained by limiting and limiting the diffusion of silver by Cu (see, for example, Patent Document 1), and by adding SrO in addition to CuO to obtain the same effect as BaO + SrO + MgO. A material for a plasma display having a limited content (for example, see Patent Document 2), a material for a plasma display having a limited content of BaO + CaO + BiO (for example,

twenty three

For example, see Patent Document 3), the contents of SiO, B O, ZnO, Bi O, BaO, and Al O were limited.

2 2 3 2 3 2 3

A material for a plasma display (for example, see Patent Document 4) is disclosed.

Patent Document 1: JP 2001-52621 A

Patent Document 2: Japanese Patent Application Laid-Open No. 2001-80934

Patent Document 3: JP 2001-48577 A

Patent Document 4: Japanese Patent Application Laid-Open No. 2003-226549

Summary of the Invention

[0006] In a conventional dielectric glass (insulating material), a phenomenon occurs in which the glass and the silver electrode react, causing a phenomenon in which the dielectric layer is colored yellow (yellowing), and the visible light transmittance is reduced. is there. It is difficult to respond to this yellowing phenomenon, but it has not yet reached the level desired by the market.

[0007] Conventionally, lead-based glass has been adopted as low-melting glass, for example, low-melting glass for coating a substrate. Although the lead component is an important component in lowering the melting point of glass, the adverse effect on the human body and the environment is significant, and in recent years there has been a trend to avoid its use, so lead-free electronic materials such as PDPs are being considered for lead-free use. Being done.

[0008] In other words, JP-A-2001-52621, JP-A-2001-80934, and JP-A-2001-48577 contain a lead which shows a considerable improvement against yellowing. There is a basic problem that. Further, Japanese Patent Application Laid-Open No. 2003-226549 does not contain lead and has a considerable improvement against yellowing. However, it contains bismuth which tends to be avoided from the environmental point of view like lead. RU

[0009] Therefore, an object of the present invention is to provide a high-V, lead-free, low-melting-point glass that suppresses yellowing due to a silver reaction and has high visible light transmittance.

[0010] According to the first feature of the present invention, it has a transparent insulating property, and contains 7 to 20 wt.

2 2 3 32 to 50, ZnO 25 to 42, R 0 (Li O + Na O + KO) 7 to 20, RO (MgO + Ca O + SrO + BaO) from 0 to 10 and CuO from 0.1 to 2 SiO—BO—ZnO—RO—CuO

Provided is a lead-free low melting glass (first glass).

[0011] According to a second feature of the present invention, it has a transparent insulating property, and contains 11 to 20% by weight of SiO and B

2 2 3 45-65, ZnO 10-20, R O (Li O + Na O + K Ο) 10-18, CuO 0.1-

2 2 2 2

2 containing SiO—B O—ZnO—R O—CuO based lead-free low melting glass (second glass)

2 2 3 2

It is.

Detailed description

According to the present invention, in an electronic substrate material represented by a plasma display panel, yellowing due to a silver reaction is suppressed and visible light transmittance is high!鉛 A lead-free low melting glass composition can be obtained.

[0013] Further, by substantially not including PbO, it is possible to eliminate the effect on the human body and the environment. Here, “contains substantially no PbO” means an amount of PbO mixed as an impurity in the glass raw material. For example, in the range of 0.3 wt% or less in the low melting glass, there is almost no adverse effect as described above, that is, there is almost no influence on the human body, the environment, the insulating property, and the like, and there is substantially no influence of PbO. Will be.

Hereinafter, features of the first glass will be described in detail.

[0015] SiO is a glass-forming component and can form stable glass.

2

In addition, it is a component that controls fluidity during firing of glass. If it is less than 7% (% by weight, the same applies to the following), the above effect cannot be exerted. If it exceeds 20%, the softening point of the glass increases, and moldability and workability become difficult. More preferably, it is in the range of 9 to 18%.

[0016] B O is a glass-forming component similar to SiO, facilitates glass melting, and provides thermal expansion of glass.

2 3 2

It suppresses an excessive increase in the coefficient, imparts appropriate fluidity to the glass during baking, and lowers the dielectric constant of the glass together with SiO. 32-50% in glass

2

Preferably. If it is less than 32%, the fluidity of the glass becomes insufficient, and the sinterability is impaired. On the other hand, if it exceeds 50%, the stability of the glass decreases. More preferably, it is in the range of 36 to 45%.

[0017] ZnO lowers the softening point of the glass and adjusts the coefficient of thermal expansion to an appropriate range, and is preferably contained in the glass in the range of 25 to 42%. When it is less than 25%, the above effects are exhibited. On the other hand, if it exceeds 42%, the glass becomes unstable and devitrification tends to occur. More preferably, it is in the range of 28 to 37%.

[0018] R O (Li 0, Na 0, K O) lowers the softening point of glass, imparts appropriate fluidity, and causes thermal expansion

2 2 2 2

The coefficient is adjusted to an appropriate range, and the content is preferably in the range of 7 to 20%. If it is less than 7%, the above effect cannot be exerted, while if it exceeds 20%, the coefficient of thermal expansion is excessively increased. More preferably, it is in the range of 10 to 17%.

[0019] CuO has an effect of mitigating the silver electrode used as a bus electrode wire reacting with the dielectric layer to diffuse silver into the dielectric layer and to develop silver colloidal color (yellowing). It is preferable to contain it in the range of 1 to 2%. If it is less than 0.1%, the above effect cannot be exerted. On the other hand, if it exceeds 2%, the glass is colored and the transparency is lowered. More preferably in the range of 0.1-1%

[0020] The oxides of Co and Mn react with a silver electrode used as a bus electrode wire of a PDP panel or the like and a dielectric layer, and silver diffuses into the dielectric layer to form silver colloid (yellowing). This has the effect of alleviating the effect, and is preferably contained in the range of 0 to 2%. If it exceeds 2%, the glass is colored and the transparency is reduced. More preferably, it is in the range of 0 to 1%. RO (MgO + CaO + SrO + BaO) gives glass an appropriate fluidity and adjusts the thermal expansion coefficient to an appropriate range, and is contained in the range of 0 to 10%. If it exceeds 10%, the coefficient of thermal expansion increases excessively. More preferably, it is in the range of 0 to 7%.

The weight ratio of B O ZZnO is preferably 0.85 or more and 2 or less. If it is less than 0.85, yellowing will occur

twenty three

The current state becomes remarkable, and if it exceeds 2, the soft point is too high. More preferably, it is in the range of 1.0 to 1.6. Further, it may be in the range of 1-2 or 1.2-1.6.

[0022] The weight ratio of (B O + R O) / SiO is preferably 2 or more and 7 or less! /. Glass less than 2

2 3 2 2

Viscosity is high and sintering is insufficient. If it exceeds 7, fluidity becomes too high and the fluctuation of transmittance becomes large. More preferably, it is in the range of 4-6.

[0023] In addition, In O, TiO, V O, Fe O, SnO, TeO, etc. represented by general oxides

2 3 2 2 5 2 3 2 2 may be added to a total amount of 0.5% as long as the object of the present invention is not impaired.

The coefficient of thermal expansion at 30 ° C. to 300 ° C. is (65 to 95) × 10 ”V ° C., and the softening point is preferably 500 ° C. or more and 600 ° C. or less. ) X 10—Thick film is formed outside of ⁷ ° C Occasionally, problems such as peeling of the coating and warping of the substrate occur. Preferably, it is in the range of (75-85) X 10 "V ° C.

When the softening point exceeds 600 ° C., problems such as soft deformation of the substrate occur. Preferably, it is 520 ° C or more and 580 ° C or less.

Hereinafter, features of the second glass will be described in detail.

[0027] SiO is a glass-forming component, and coexists with another glass-forming component, B O.

2 2 3

More stable glass can be formed, and the content is 11% (% by weight, the same applies to the following). If it exceeds 20%, the softening point of the glass increases, and formability and workability become difficult. More preferably, it is in the range of 14 to 18%.

[0028] B O is a glass-forming component similar to SiO, and facilitates glass melting and thermal expansion of glass.

2 3 2

It suppresses an excessive increase in the coefficient, imparts appropriate fluidity to the glass during baking, and lowers the dielectric constant of the glass together with SiO. 45-65% contained in glass

2

Preferably. If it is less than 45%, the fluidity of the glass becomes insufficient and the sinterability is impaired. On the other hand, if it exceeds 65%, the stability of the glass is reduced. More preferably, it is in the range of 48 to 63%.

[0029] ZnO lowers the softening point of the glass and adjusts the thermal expansion coefficient to an appropriate range, and is preferably contained in the glass in the range of 10 to 20%. If it is less than 10%, the above effect cannot be exerted, while if it exceeds 20%, the glass becomes unstable and devitrification tends to occur. More preferably, it is in the range of 10 to 18%.

[0030] R O (Li 0, Na 0, K O) lowers the softening point of glass, imparts appropriate fluidity, and causes thermal expansion.

2 2 2 2

The coefficient is adjusted to an appropriate range, and the content is preferably in the range of 10 to 18%. If it is less than 10%, the above effect cannot be exerted, while if it exceeds 18%, the coefficient of thermal expansion is excessively increased. More preferably, it is in the range of 11 to 17%.

[0031] CuO has the effect of reducing the reaction between the silver electrode used as the bus electrode wire and the dielectric layer, and the diffusion of silver into the dielectric layer to reduce silver colloidal coloration (yellowing). It is preferable to contain it in the range of 1 to 2%. If the content is less than 0.1%, the above effect cannot be exerted. On the other hand, if it exceeds 2%, the glass is colored and the transparency is reduced. More preferably, it is in the range of 0.1 to 1%. RO (MgO + CaO + SrO + BaO) gives the glass a moderate fluidity, It is adjusted to an appropriate range, and is contained in the range of 0 to 20%. If it exceeds 20%, the coefficient of thermal expansion increases excessively. More preferably, it is in the range of 0 to 10%.

Further, it is desirable that the weight ratio of B O ZZnO is 2 or more and 6 or less. Yellow if less than 2

twenty three

The change becomes remarkable, and when it exceeds 6, the stability is deteriorated. More preferably, it is in the range of 3-5.

[0033] MnO reacts with a silver electrode used as a bus electrode line and a dielectric layer to form a dielectric layer.

2

It has an effect of mitigating silver colloidal coloring (yellowing) due to the diffusion of silver therein, and is preferably contained in the range of 0 to 2%. If it exceeds 2%, the glass is colored and the transparency is reduced. More preferably, it is in the range of 0 to 1%.

[0034] In addition, In O, TiO, SnO, Al O, TeO, and the like represented by general oxides are added.

2 3 2 2 2 3 2

[0035] By substantially not including PbO, it is possible to eliminate the effect on the human body and the environment. Here, “contains substantially no PbO” means an amount of PbO mixed as an impurity into the glass raw material. For example, within the range of 0.3 wt% or less in the low melting glass, the above-mentioned adverse effects, that is, the effects on the human body, the environment, the insulating properties, and the like are almost nil, and the effects of PbO are substantially unaffected. , It will be.

[0036] The above-mentioned lead-free low-melting glass having a thermal expansion coefficient of (65 to 95) X 10 "V ° C at 30 ° C to 300 ° C and a softening point of 500 ° C to 630 ° C. . coefficient of thermal expansion ^{(65~95) X 10- 7 Z °} C outside the peeling of the coating when a thick film forming, problems such as warpage of the substrate occurs. preferably, (75~85) X 10- ⁷ / ° C. When the softening point exceeds 630 ° C., problems such as soft deformation of the substrate occur, and the temperature is preferably 500 ° C. or more and 590 ° C. or less.

Hereinafter, features of both the first and second glasses will be described in detail.

[0038] They may be electronic material substrates using the above low melting point glass. By using the above-mentioned low-melting glass, a substrate for electronic materials with suppressed yellowing can be obtained.

Further, they may be PDP panels using the above-mentioned low melting point glass.

By using the above-mentioned low-melting glass, a PDP panel with reduced yellowing can be obtained. [0040] The first and second glasses of the present invention are preferred as low-melting-point glasses corresponding to the yellowing phenomenon caused by the reaction with silver! /, But their use is limited to an insulating material around the silver electrode. ! /, Not necessarily.

[0041] The lead-free low-melting glass (first and second glasses) of the present invention can be used, for example, as a front plate or a back plate of PDP glass. When used as a back plate, it is used as a sealing material and a coating material, and is often used in the form of powder. The powdered glass is mixed with a low-expansion ceramic filler such as mullite or alumina, a heat-resistant pigment, or the like at a ratio of 0.6 {glass Z (glass + filler) weight} or more, if necessary. Next, the mixture is generally kneaded with an organic oil and pasted.

[0042] As the glass substrate, a transparent glass substrate, in particular, a soda-lime-silica-based glass or a glass similar thereto (high-strain-point glass), or a low alkali content! /, (Or almost no! ヽ) Alumino-lime borosilicate glass is frequently used.

[0043] The following non-limiting examples 1-6 illustrate the first glass of the present invention. In contrast, the following Comparative Examples 1 to 6 are contrasted with them.

(Examples 1 to 6 and Comparative Examples 1 to 6)

(Preparation of low-melting glass mixed paste)

Fine silica sand as SiO source, boric acid as B O source, zinc white as ZnO source, Li O source

Lithium carbonate as 2 2 3 2, sodium carbonate as Na O source, potassium carbonate as K O source,

twenty two

CuO source as CuO source, NiO2 manganese source as MnO source, and carbonic acid as MgO source

2

It required magnesium, calcium carbonate as a CaO source, strontium carbonate as a SrO source, and barium carbonate as a BaO source. These were mixed to obtain the desired low-melting glass composition, placed in a platinum crucible, and heated and melted in an electric furnace at 1000 to 1300 ° C for 1 to 2 hours, followed by Examples 1 to 6 in Table 1. Glasses having the compositions shown in Comparative Examples 1 to 6 in Table 2 were obtained.

[Table 1] Example

Glass »

Z c SBCN ^ cSBU

[Table 2] Comparative Example Ϊ 2 3 4 5 6 Glass Composition SiOz 12.4 1 1.9 S S S Ξ 14.0 4.2 23.5 8.7

36.4 46.t 30.0 57.1 32.1 30.7

ZnO 46.9 10.8 22.9 24.0 22.4 47.8

MgO 1.0

CaO 8.9 4.0 2.5

SrO 2.0 2.0 0.4

BaO 17.2 8.0

U20

Na20 4.3 31.2 5.0

κ ₂ ο 10.7 8.5 12.4

BiOs / ZnO 0.8 4.3 1.3 2.4 1.4 0.64

((¾0 + B ₂ 0j) / Si0! 3.3 6.5 2.5 16.t 1.7 5.0

¾ coefficient ⁷ ° C 56 119 62 77 * 81 Softening point ° C 609 487 615 584 * 587 Suppression of yellowing *

Fluctuation in transmittance T96 * * x * O Stability

mw T _S Blue of H Baking indefinite melting Volatile at M

'Mark is ¾SS bad, let's go "

[0047] A part of the glass was poured into a mold, made into a block shape, and provided for measurement of thermophysical properties (thermal expansion coefficient, softening point). The remaining glass was flaked by a quenching twin roll forming machine and sized by a pulverizer into a powder having an average particle size of 1 to 3 µm and a maximum particle size of less than 10 m.

Next, ethyl cellulose as a binder and the above glass powder were mixed with a paste oil consisting of α-terpineol and butyl carbitol acetate to prepare a paste having a viscosity of about 300 ± 50 poise.

(Formation of insulating film)

Apply the paste using an applicator to a soda-lime glass substrate with a thickness of 2 to 3 mm and a size of 100 mm square, taking into account that the thickness after baking is about 20 m. A fabric layer was formed.

[0050] Next, after drying, baking was performed at 600 ° C or lower for 10 to 60 minutes to form a clear dielectric layer.

[0051] The obtained sample was observed with the naked eye and a microscope. When the yellowing phenomenon was judged to be remarkably suppressed as compared with the conventional sample, the symbol "〇" was given.

[0052] Regarding the variation of the transmittance, a sample having a variation of the transmittance (550 nm) of 4% or less when the firing temperature was changed by 30 ° C was designated as Δ, and the others were designated as X.

[0053] The softening point is used Littleton viscometer and a temperature when it reaches the viscosity coefficient r? = 10 ⁷ · ^6. The coefficient of thermal expansion was determined from the amount of elongation at 30 to 300 ° C when the temperature was increased by 5 ° CZ using a thermal dilatometer.

[0054] (Result)

Tables 1 and 2 show the low melting glass composition and the results of various tests.

[0055] As shown in Examples 1 to 6 in Table 1, in the composition range of the first glass of the present invention, the occurrence of yellowing was remarkably suppressed as compared with the conventional glass.

[0056] On the other hand, Comparative Examples 1 to 6 in Table 2, which deviate from the composition range of the first glass of the present invention, show remarkable yellowing or do not show preferable physical property values as in the conventional case, such as PDP. It cannot be applied as a low melting glass for coating substrates.

[0057] The following non-limiting examples 1-7 illustrate the second glass of the present invention. In contrast, the following Comparative Examples 1-2 contrast with them.

(Examples 1 to 7 and Comparative Examples 1 and 2)

(Preparation of Low Melting Glass)

The production of the low melting point glass mixing base in Examples 1 to 6 relating to the first glass of the present invention described above was repeated. As a result, glasses having the compositions shown in Examples 1 to 7 in Table 3 and Comparative Examples 3 to 4 in Table 4 were obtained.

[Table 3] Example

Crow composition SiOz 16.6 1.2 12.5 11.1 12.7

BzOs 49.3 55.6 61.2 64.7 59.8

ZnO 16.9 H.3 12.5 11.3 1 1.9

R2O (Li _z O + Na ₂ 0 + K2O) 16.7 15.3 13.5 12.1 12.6

CuO 0.5 0.5 0.3 0.5 1.5 n0 ₂ 0.1 0.3 1.5

(ROC gO + CaO + SrO + BaO)

_{_{wt% B 2 0 3 / ZnO}} 2.9 3.9 4.9 5.7 5.1

Softening point (° C) 563 552 543 538 535 578 561 Coefficient of thermal expansion (X I 0-7Z ° C) 80 77 75 73 74 82 80 Suppression of yellowing 〇 ―〇〇 O O 〇 O

[Table 4]

RO (MgO + CaO + SrO + BaO) 29.2

wt% BzOa / ZnO 1.5 0.7

Softening point (° C) 655 483

Thermal expansion coefficient (x i 0-7 ° C) 63 98

Yellowing suppression Note 1) Note 1)

Note 1) Not implemented for physical property failure.

[0061] The sizing, preparation of the paste, and formation of the coating layer in Examples 1 to 6 relating to the first glass of the present invention described above were repeated. Next, after drying, baking was performed at 630 ° C. or lower for 10 to 60 minutes to form a clear dielectric layer.

[0062] The obtained sample was observed with the naked eye and a microscope, and when the yellowing phenomenon was judged to be remarkably suppressed as compared with the conventional sample, the symbol "〇" was given.

[0063] The softening point is used Littleton viscometer, viscosity coefficient η = 10 ⁷ - was taken to be the temperature at which reached ^6. The coefficient of thermal expansion was determined from the amount of elongation at 30 to 300 ° C when the temperature was increased by 5 ° CZ using a thermal dilatometer.

[0064] (Results)

Tables 3 and 4 show the low melting glass composition and the results of various tests.

[0065] As shown in Examples 1 to 7 in Table 3, the development of yellowing was remarkably suppressed in the range of the composition of the second glass of the present invention as compared with the conventional glass.

[0066] On the other hand, Comparative Examples 1 and 2 in Table 4, which are out of the composition range of the present invention, show yellowing as in the conventional case. Is remarkable, or does not show preferable physical properties, and cannot be applied as a low melting glass for coating a substrate such as PDP.

Claims

The scope of the claims

[I] Transparent insulation, SiO: 7 to 20, B O: 32 to 50, ZnO: 25 to 42, R O by weight%

2 2 3 2

(Li O + Na O + K Ο) 7-20, CuO 0.1-2, RO (MgO + CaO + SrO + BaO

2 2 2

) Is a lead-free low-melting glass based on SiO-B O-ZnO-R O-CuO.

2 2 3 2

[2] The method according to claim 1, wherein the weight ratio of B O ZZnO is 0.85 or more and 2 or less.

twenty three

Lead-free low melting glass.

[3] The non-woven fabric according to claim 2, wherein the weight ratio of B O ZZnO is 1 or more and 2 or less.

twenty three

Lead low melting glass.

[4] The weight ratio of (B O + R O) / SiO is 2 or more and 7 or less.

2 3 2 2

The lead-free low-melting glass according to claim 3.

[5] The lead-free low-melting glass according to any one of claims 1 to 4, wherein Co or Mn is contained in an amount of 0 to 2 in weight% as an oxidized product.

[6] 30 ° C~300 ° C coefficient of thermal expansion is ^{65 X 10- 7 Z ° C~95 X} 10 "V ° C, softening point 50

The lead-free low-melting glass according to any one of claims 1 to 5, wherein the temperature is 0 ° C or higher and 600 ° C or lower.

[7] A substrate for electronic materials, which uses the lead-free low-melting glass according to any one of claims 1 to 6.

[8] A PDP panel using the lead-free low-melting glass according to any one of claims 1 to 7.

[9] Transparent insulation, SiO: 11-20, B O: 45-65, ZnO: 10-20, R by weight%

2 2 3 2

0 (Li O + Na O + K O) 10-18, CuO 0.1-2 SiO- B O- ZnO- R

2 2 2 2 2 3 2

O— CuO-based low melting point glass.

[10] The non-woven fabric according to claim 9, wherein the weight ratio of B O ZZnO is 2 or more and 6 or less.

twenty three

Lead low melting glass.

[II] The method according to claim 9 or 10, wherein MnO is contained in an amount of 0 to 2 by weight%.

2

Lead low melting glass.

[12] The lead-free low-melting glass according to any one of claims 9 to 11, which contains 0 to 20 of RO (MgO + CaO + SrO + BaO) by weight.

[13] and wherein the thermal expansion coefficient at 30 ° C~300 ° C is ^{65 X 10- 7 Z ° C~95 X} 10 "V ° C, softening point is less than 50 0 ° C or 630 ° C The lead-free low-melting glass according to any one of claims 9 to 12.

[14] A substrate for an electronic material, comprising the lead-free low-melting glass according to any one of claims 9 to 13.

[15] A PDP panel using the lead-free low-melting glass according to any one of claims 9 to 13.