JP2010129176A - Glass tube for compact self-ballasted lamp and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a glass tube for a compact self-ballasted lamp resistant to crack and capable of restraining stain from adhering to the surface. <P>SOLUTION: The glass tube 10 for a compact self-ballasted lamp is provided with a globe-shape glass bulb 12 formed of glass containing 10 to 25 wt.% Na<SB>2</SB>O and 0.1 to 5 wt.% K<SB>2</SB>O, and a protective film 14 containing a nonionic surfactant with an HLB value of 8 or more and fitted so as to cover a part or whole of an outer surface of the glass bulb 12, with an angle of slide of 25° or less. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a glass tube for a light bulb shaped lamp and a manufacturing method thereof.

2. Description of the Related Art Conventionally, incandescent bulbs having a light emitting body including a filament in a glass bulb as an envelope have been mainly used as lighting for general homes. However, in recent years, instead of this incandescent light bulb, it is possible to achieve both energy saving and reduction of CO ₂ emission and to prevent global warming. There is an increasing demand for light bulb shaped lamps such as fluorescent lamps and light bulb shaped LEDs.

  By the way, a glass tube used as an outer tube of a light bulb shaped lamp (also simply referred to as a “bulb shaped glass tube”) is thinner than a general fluorescent glass tube, so it is being manufactured, stored and transported. In such a case, when the glass tubes are in contact with each other or in contact with other members, the surface is likely to have small scratches. If such small scratches are present on the surface of the bulb-shaped glass tube, the bulb-shaped glass tube may be broken during the process of manufacturing the lamp, or the appearance quality of the completed lamp may be deteriorated. Moreover, the deterioration of the appearance quality of the lamp is also caused by dirt that can adhere to the surface of the glass tube during the manufacturing process. Therefore, in the field of manufacturing a light bulb-shaped glass tube, it is desired to establish a technology that can provide a light bulb-shaped glass tube that is less likely to be scratched and soiled, that is, has good scratch resistance and appearance on the surface.

Up to now, as glass products that can prevent damage on the surface of various glass products such as plate glass, bottle glass, tube glass, and glass for electronic parts and contamination due to dirt, for example, part or all of the surface of the glass product Discloses a glass product in which a water-soluble protective film containing an anionic surfactant is formed (see Patent Document 1).
Japanese Patent Laid-Open No. 2000-211947

  However, when the technique described in Patent Document 1 is applied to a light bulb shaped glass tube having a complicated appearance, it has been difficult to sufficiently suppress good scratch resistance and adhesion of dirt.

  Accordingly, in view of the above problems, an object of the present invention is to provide a glass tube for a light bulb shaped lamp with good surface scratch resistance and appearance, and a method for producing the glass tube for the light bulb shaped lamp.

  As a result of intensive studies, the present inventors have found that the above problem can be solved by covering the surface of the bulb-shaped glass tube with a protective film containing a specific surfactant. That is, the said subject is solved by the following this invention.

  The glass tube for a light bulb shaped lamp of the present invention has the following configuration.

[1] A glass bulb for a light bulb made of a glass composition containing 10 to 25 wt% Na ₂ O and 0.1 to 5 wt% K ₂ O, and a nonionic interface having an HLB value of 8 or more And a protective film provided so as to cover part or all of the outer surface of the glass bulb, and having a sliding angle of 25 ° or less. tube.

  [2] The glass tube for a bulb lamp according to [1], wherein the nonionic surfactant is a substance represented by the following formula (1).

R—O— (EO) _n —H (1)
In the formula, R represents a linear alkyl group having 12 to 18 carbon atoms; n represents an average addition mole number and represents an integer of 4 or more; EO represents an ethyleneoxy group (CH ₂ CH ₂ O). To express.

  Moreover, the manufacturing method of the glass tube for light bulb shaped lamps of this invention has the following structures.

[3] A method of manufacturing a glass tube for a light bulb shaped lamp having a protective film formed on the outer surface, comprising 10 to 25% by weight of Na ₂ O and 0.1 to 5% by weight of K ₂ O A step of preparing a glass bulb for a light bulb made of the composition, and a coating amount of a nonionic surfactant having an HLB value of 8 or more on a part or all of the outer surface of the glass bulb is 0.002 μg / cm ^A method for producing a glass tube for a light bulb shaped lamp, comprising: a step of applying an aqueous solution so as to be ² or more; and a step of drying a wet film obtained by the application to form a protective film. .

[4] The method for producing a glass tube for a light bulb shaped lamp according to [3], wherein the coating amount of the nonionic surfactant is 0.3 μg / cm ² or less.

  [5] The step of applying the aqueous solution to the outer surface of the glass bulb is a step of forming the wet film by spraying an aqueous solution containing the nonionic surfactant onto the outer surface of the heated glass bulb. The method for producing a glass tube for a light bulb shaped lamp according to [3] or [4].

  [6] The glass tube for a bulb-shaped lamp according to any one of [3] to [5], wherein the nonionic surfactant is a substance represented by the following formula (2): Production method.

R—O— (EO) _n —H (2)
In the formula, R represents a linear alkyl group having 12 to 18 carbon atoms; n represents an average addition mole number and represents an integer of 4 or more; EO represents an ethyleneoxy group (CH ₂ CH ₂ O). To express.

  [7] The glass tube for a light bulb shaped lamp according to [5], wherein the step of forming the protective film is a step of drying the wet film by heat of the heated glass bulb. Production method.

  [8] The molten glass composition is molded as a raw material, the aqueous solution is applied to the outer surface of the glass bulb where heat during molding remains, and the wet film is dried by the heat remaining in the glass bulb. [7] The manufacturing method of the glass tube for bulb-type lamps as described in [7].

  [9] The glass tube for a light bulb shaped lamp according to [7] or [8], wherein the temperature of the outer surface of the glass bulb immediately before the aqueous solution is applied is 100 to 450 ° C. Production method.

  According to the present invention, it is possible to provide a glass tube for a light bulb shaped lamp having a good surface scratch resistance and appearance, and a method for producing the glass tube for a light bulb shaped lamp.

  Hereinafter, the glass tube for a light bulb shaped lamp of the present invention and the manufacturing method thereof will be described. However, the present invention is not limited to the form shown here, and the form is not limited as long as the effect of the present invention is obtained.

1. As shown in FIG. 1, a glass tube 10 for a light bulb shaped lamp according to the present invention covers a bulb-shaped glass bulb 12 serving as an envelope of the lamp and an outer surface of the glass bulb 12. And a protective film 14 provided as described above.

[Glass tube]
The glass bulb 12 includes a neck portion 12a and an inflatable portion 12b formed in a non-linear shape. The shape of the glass bulb 12 of the present invention is not particularly limited as long as it is used for a light bulb. For example, B-shaped, BA-shaped, BT-shaped, C-shaped, G-shaped, T-shaped, and R-shaped A shape known as a bulb for a simple light bulb is included. Further, since the glass bulb 12 is made of a glass composition containing Na ₂ O at 5% by weight or more and K ₂ O at 3% by weight or more, the surface thereof has polarity and exhibits high hydrophilicity.

[Protective film]
The protective film 14 of the present invention is a film containing a nonionic surfactant having an HLB value of 8 or more. The HLB (Hydrophile-Lipophile Balance) value is a value representing the degree of affinity of a surfactant for water, and is defined by the following formula (3) based on the Griffin method. In general, a surfactant having a higher HLB value has higher affinity for water and better adhesion to the surface of a member exhibiting hydrophilicity.

HLB value = 20 × (sum of formula weight of hydrophilic part / molecular weight) (3)
The protective film 14 of the present invention containing such a nonionic surfactant having an HLB value of 8 or more has a hydrophilic property that does not ionize when dissolved in a lipophilic group (hydrophobic group) and water. Groups are present and exhibit high hydrophilicity. Therefore, the said protective film 14 is easy to adhere with respect to the surface of the glass bulb | ball 12 which exhibits hydrophilic property similarly. Further, in the vicinity of the interface 16 between the protective film 14 and the surface of the glass bulb 12, a strong force is exerted by a chemical bond between a hydrophilic group present in the protective film 14 and a polar group present on the surface of the glass bulb 12. Therefore, the glass tube 10 for a light bulb shaped lamp of the present invention in which the surface of the glass bulb 12 is covered with a protective film 14 with a strong force has the characteristics that the scratch resistance is good and the dirt hardly adheres. In the present invention, a nonionic surfactant having an HLB value of 8 or more is used for reasons such as high adhesion to the glass surface, but the upper limit of the HLB value is not particularly limited, and is usually 18. is there.

  Moreover, since lipophilic groups are gathered on the surface of the protective film 14 opposite to the glass bulb 12, the sliding angle θ of the bulb-shaped glass tube 10 is 25 ° or less. The sliding angle θ is an inclination angle with respect to a reference surface of the measuring table when the glass tube starts to slide on the measuring table having an inclination. This means that the smaller the sliding angle, the smaller the frictional force acting between the glass tubes when a plurality of bulb-type lamp glass tubes are adjacent to each other. The conventional bulb-type lamp glass tube has a sliding angle θ of about 30 to 35 °. However, the bulb-type lamp glass tube of the present invention has a small sliding angle θ of 25 ° or less. Even if they are adjacent to each other, they slide on each other, so that scratches caused by rubbing or colliding are less likely to occur. In the present invention, the symbol “˜” includes values at both ends thereof.

[Measurement method of slip angle]
The sliding angle θ of the present invention can be easily measured according to the following method with reference to the provisions of the Japan Glass Bottle Association standard. Specifically, first, as shown in FIG. 2 (b), the glass tube 10 for a light bulb shaped lamp is set in a jig 20 made of acrylic resin, which is horizontally arranged. At this time, as shown in FIG. 2 (a), the bulb-shaped lamp glass tube 10 is set in a state where the base portion of the bulb-shaped lamp glass tube is inserted into the cut portion of the U-shaped jig 20. To do.

  Next, the jig 20 is gradually inclined until the bulb-shaped lamp glass tube 10 starts to slide. Then, the inclination angle θ when the bulb-shaped lamp glass tube 10 starts to slide is measured as the slip angle θ.

  The nonionic surfactant having an HLB value of 8 or more of the present invention is preferably an ether type nonionic surfactant represented by the following formula (4). Such an ether type nonionic surfactant has a large cohesive force of the surfactant, and the protective film is hardly peeled off from the surface of the glass bulb, so that an excellent scratch resistance effect lasts longer.

R—O— (EO) _n —H (4)
In the formula, R represents a linear alkyl group having 12 to 18 carbon atoms, n is an average addition mole number, and represents an integer of 4 or more, and EO represents an ethyleneoxy group (CH ₂ CH ₂ O). To express. Among these, n in the formula is preferably an integer of 30 or more.

  Examples of the ether type nonionic surfactant include polyoxyethylene alkyl ether, polyoxyethylene alkyl phenyl ether, polyoxyethylene alkyl ether phosphoric acid, polyoxyethylene polyoxypropylene alkyl ether, polyoxyethylene sorbitan monooleate And polyoxyethylene sorbitan monostearate and polyoxyethylene sorbitan monopalmitate.

  Note that the protective film in the present invention does not necessarily have to be formed so as to cover the entire surface of the glass bulb, and may be partially formed only on a portion where it is particularly desired to prevent scratch resistance and adhesion of dirt.

[Glass composition]
The glass composition forming the glass bulb of the present invention (also referred to as “the glass composition of the present invention”) contains Na ₂ O at least 10 wt% and K ₂ O at least 0.1 wt%, Its composition is not particularly limited. However, when the content of Na ₂ O exceeds 25% by weight or the content of K ₂ O exceeds 5% by weight, the alkali component is likely to be eluted from the glass bulb, and the exuded alkali component is contaminated. This may deteriorate the appearance quality of the glass bulb. Therefore, from the viewpoint of high hiding property and the light flux by the protective film of the glass bulb to provide a high fluorescent lamp, the glass composition of the present invention, the Na 2 _O 5 to 17 wt%, 3 to 7 weight K 2 _O % Glass composition is preferred.

  Preferred examples of the glass composition of the present invention include the following compositions.

SiO _2: 55 to 75 _{wt%, B} 2 O 3: _{0~5 wt%, Al} 2 O 3: _{0~5 wt%,} Li 2 O: _{0~5 wt%,} Na 2 O: _5~17 wt% , _K 2 O: 3~7 wt%, MgO: 0 to 5 wt%, CaO: 0 wt%, SrO: 0 wt%, BaO: 0% by weight.

Among them, SiO ₂ is a main component of the glass composition of the present invention, and is an essential component for forming the basic structure of glass. However, if SiO ₂ is less than 55% by weight, it is difficult to form glass, and if it exceeds 75% by weight, it becomes difficult to melt the glass, and the viscosity of the glass increases and it is difficult to mold. Therefore, from the viewpoint of obtaining a high-quality glass tube, it is preferable that SiO ₂ in the glass composition is in the range of 55 to 75% by weight.

Li ₂ O, which is an alkali metal oxide, decreases the viscosity of the glass and improves the melt processability. However, an essential component of the glass composition of the present _invention, Na 2 _{O, K} 2 O is also an alkali metal oxide, similarly or reduce the viscosity of the glass and LiO _2, or to improve the melt processability Also shows the effect. Therefore, in the glass composition of the present invention, Li ₂ O is not an essential component and is preferably contained in the range of 0 to 5% by weight. _Note that as described above for the proper content of Na ₂ O, _K 2 O.

  The alkaline earth metal oxides MgO and CaO are preferably contained in the glass composition of the present invention from the viewpoint of improving the electrical insulating properties and chemical durability of the glass. However, in the glass composition, if MgO is less than 0.5% by weight and CaO is less than 1% by weight, it becomes difficult to improve the electrical insulation and chemical durability of the glass. If it exceeds 5% by weight or CaO exceeds 10% by weight, it may be difficult to ensure high transparency of the glass. Therefore, from the viewpoint of obtaining a glass product having good electrical insulation, chemical durability, and translucency, a glass composition containing 0.5 to 5% by weight of MgO and 1 to 10% by weight of CaO. preferable.

  SrO and BaO are preferably contained in the glass composition of the present invention from the viewpoint of improving the electrical insulation of the glass. However, if the glass composition contains SrO and BaO in excess of 10% by weight, the translucency of the glass product may be reduced. Therefore, from the viewpoint of obtaining a highly translucent glass product, the SrO and BaO contents in the glass composition are each preferably 10% by weight or less.

B ₂ O ₃ is preferably contained in the glass composition of the present invention from the viewpoint of improving the chemical durability of the glass and reducing the viscosity of the glass and improving the melt processability. However, if B ₂ O ₃ is less than 1% by weight, the melt processability of the glass may be deteriorated. Therefore, the content of B ₂ O ₃ is preferably 1% by weight or more.

Al ₂ O ₃ is preferably contained in the glass composition of the present invention from the viewpoint of improving the chemical durability of the glass. However, if the glass composition contains less than 0.5% by weight of Al ₂ O ₃ , it is difficult to improve the chemical durability of the glass, while the content of Al ₂ O ₃ is 5% by weight. If it exceeds%, the melt processability of the glass may be reduced. Therefore, a glass composition containing 0.5 to 5% by weight of Al ₂ O ₃ is preferable.

2. Manufacturing method of glass tube for light bulb shaped lamp The glass tube for a light bulb shaped lamp of the present invention can be arbitrarily manufactured within a range not impairing the effects of the invention, and a preferable manufacturing method will be described below.

An example of a preferred method for producing a glass tube for a light bulb shaped lamp of the present invention is as follows:
A method for producing a glass tube for a light bulb shaped lamp having a protective film formed on an outer surface,
1) providing a bulb-shaped glass bulb made of the glass composition comprising 10 to 25 wt% of _Na 2 O, and 0.1 to 5 wt% of _{K 2} O,
2) A step of applying an aqueous solution to a part or all of the outer surface of the glass bulb so that the application amount of a nonionic surfactant having an HLB value of 8 or more is 0.002 μg / cm ² or more;
3) drying the wet film obtained by the application to form a protective film;
It is characterized by including.

In the above method, first, in the step 1), a bulb-shaped glass bulb containing 10 to 25% by weight of Na ₂ O and 0.1 to 5% by weight of K ₂ O is prepared.

Next, in step 2), an aqueous solution is applied to a part or all of the outer surface of the glass bulb so that the coating amount of the nonionic surfactant having an HLB value of 8 or more is 0.002 μg / cm ² or more. Then, a wet film is formed on the outer surface of the glass bulb.

  The wet film refers to a wet film containing a nonionic surfactant and moisture. The wet film of the present invention is formed from an aqueous solution containing the above-described nonionic surfactant having an HLB value of 8 or more and water. Since this aqueous solution contains a nonionic surfactant having good compatibility with water, the wettability during coating is good. Therefore, when this aqueous solution is used, the surface of the bulb-shaped glass bulb having a complicated appearance can be uniformly covered with the aqueous solution.

  Examples of water used for preparing the aqueous solution include ultrapure water, pure water, ion exchange water, and distilled water. In the present invention, pure water and ultrapure water are obtained by passing tap water through activated carbon and subjecting it to ion exchange treatment, followed by further distillation, and if necessary, irradiating light from a predetermined ultraviolet germicidal lamp or passing it through a filter. What you did.

  In the present invention, the amount of the nonionic surfactant contained in the aqueous solution is preferably 0.01 to 5% by weight. This is because if the content of the nonionic surfactant is less than 0.01% by weight, it is difficult to obtain scratch resistance, and if it exceeds 5% by weight, stickiness of the surface, adsorbed dirt, etc. cannot be suppressed. Among these, in addition to the realization of high scratch resistance and the suppression of stickiness and the occurrence of adsorption dirt, the amount of nonionic surfactant contained in the aqueous solution is from the viewpoint that processing at low cost is possible. More preferably, the content is 0.01 to 1% by weight.

  The method for applying the aqueous solution to the surface of the glass bulb is not particularly limited. The aqueous solution is applied to the surface of the glass bulb (brush coating method), sprayed (spray method), or the glass bulb is immersed in the aqueous solution. A known method such as (immersion method) is employed. Among these, the spray method is preferable from the viewpoint that the aqueous solution can be applied with good uniformity only to the outer surface of the glass tube without attaching the aqueous solution to extra portions such as the inner peripheral surface of the glass bulb. When the spray method is employed, the aqueous solution can be easily applied even to a heated glass bulb. In the present invention, the case where an aqueous solution is applied to the surface of the glass bulb to form a wet film is also referred to as “during application”.

From the viewpoint of realizing good scratch resistance, the coating amount of the nonionic surfactant per unit area of the glass bulb may be 0.002 μg / cm ² or more. However, if the coating amount of the nonionic surfactant is too large, there is a concern that stickiness, adsorption dirt, etc. may occur in the glass tube for a light bulb shaped lamp on which a protective film is formed. From such a viewpoint, the coating amount of the nonionic surfactant is preferably 0.3 μg / cm ² or less.

  During the coating operation, it is preferable to perform the operation while paying attention to the surface temperature T (° C.) of the glass bulb. The surface temperature T of the glass bulb is the temperature of the outer surface of the glass tube immediately before the aqueous solution is applied, and is a value measured by the method described in the examples described later. The surface temperature T is not particularly limited, but in the case of a spray method, the glass bulb is preferably heated to such an extent that the surfactant in the applied aqueous solution is not thermally decomposed. Specifically, for example, the T is preferably 450 ° C. or lower, and more preferably 400 ° C. or lower. Further, from the viewpoint of more firmly attaching a protective film to the surface of the glass bulb without reducing the activation of the nonionic surfactant, the T is preferably 380 ° C. or lower, and 350 ° C. or lower. More preferably.

  In the step 3), the wet film is dried to form a protective film. The method for drying the wet film is not particularly limited, and a known method may be used. Examples of the drying method include a method of using a heating device such as an oven, blowing hot air, and naturally drying. Among them, from the viewpoint of improving productivity, reducing costs, and forming a more uniform protective film, a method of drying the wet film with the heat of the heated glass bulb is preferable. Specifically, in the step 1), a glass bulb is produced from the melt-softened glass composition, and subsequently, in the cooling process, an aqueous solution is applied to the glass bulb where heat during molding remains. . Alternatively, an aqueous solution may be applied to the reheated glass bulb, and the wet film may be dried by the heat of the glass bulb. The glass bulb of the present invention includes a molded product during the cooling.

  In the step 3), when the wet film is dried using the heat remaining in the glass bulb by heating, the surface temperature T of the glass bulb is preferably 100 ° C. or higher, and more preferably 120 ° C. or higher.

[Examples 1 to 8]
An aqueous solution containing a predetermined nonionic surfactant was applied to a bulb-shaped glass tube having an outer surface temperature of 350 to 400 ° C. by spray coating, and the wet film was dried to obtain a glass tube for a bulb-type lamp. . Table 1 shows the glass composition, the concentration of the surfactant in the aqueous solution, the type of the surfactant, and the coating amount of the surfactant per unit area in each example. Further, the wet film was dried by the heat of the glass tube.

  Moreover, the temperature of the outer surface of the glass bulb just before apply | coating aqueous solution was measured with the thermo viewer (Cino Co., Ltd. make, CPA-8000). At that time, the emissivity was set to e = 0.86, and the measurement locations were set at the three ends in the longitudinal direction and the center. The temperatures at the three locations were all in the temperature range of 350 to 400 ° C.

  The glass tube for a light bulb shaped lamp obtained in this example was evaluated for (1) slip angle, (2) glass strength reduction rate, and (3) appearance / stickiness. The results are shown in Table 1.

(1) Measurement of sliding angle The sliding angle of the glass tube for bulb-type lamps was measured by the method described with reference to FIG.

(2) Measurement of glass strength In order to evaluate the scratch resistance (scratch resistance) of the glass tube for a light bulb shaped lamp, the glass strength at the spherical portion of the bulb-shaped glass bulb before and after the scratch test was measured and evaluated.

  First, as shown in FIG. 3, the spherical portion of the bulb-shaped lamp glass tube 10 is placed on the lower jig 30 having a recess along the shape of the spherical portion of the bulb. Next, the upper jig 32 was pressed against the upper part of the spherical part of the glass tube 10 for bulb-type lamps which was left still, and the load was loaded with respect to the spherical part. And the intensity | strength when a spherical surface part destroyed with the applied load was measured as a breaking strength. In this test, a strength tester (manufactured by Shimadzu Corporation Autograph) was used, the load speed was 1 mm / min, and the number of samples was n = 20.

  Moreover, the result of the measured breaking strength was Weibull plotted, and the glass strength was calculated. This glass strength refers to the strength at the time of 63.2% fracture probability when the Weibull plot is performed.

(3) Appearance and stickiness In order to evaluate the appearance quality of the glass tube for bulb-type lamps, the appearance of the completed glass tube for bulb-type lamps is visually confirmed, and the presence of scratches on the appearance and the degree of contamination do not become a problem in the product. The evaluation was made in two stages, where the level was ○ and the level causing a problem on the product was ×.

[Comparative Examples 1 to 7]
Comparative Examples 1-7, as shown in Table 2, produced glass tubes for light bulb shaped lamps in the same manner as in the Examples, except that the glass compositions, nonionic surfactants having different HLB values, and the like were evaluated. did.

  As apparent from Tables 1 and 2, the glass tube for a light bulb shaped lamp of the present invention has a sliding angle of 25 ° or less and a glass strength reduction rate of 20% or less. Scratches on the outer surface of the bulb-shaped glass bulb in the manufacturing process of a lamp using a glass tube for a bulb-shaped lamp, when the rate of decrease in the characteristic strength of the glass after the scratch test is 20% or more. The possibility that the glass tube breaks due to this is significantly improved. On the other hand, as apparent from Table 2, the glass tubes for light bulb shaped lamps of Comparative Examples 1-3, 6, and 7 have a sliding angle of 25 ° or more and a glass strength reduction rate of 25% or more. It became. From this result, it is clear that the occurrence of scratches on the surface of the glass tube for a light bulb shaped lamp of the present invention is kept low. In addition, the glass tube for a light bulb shaped lamp of the present invention was suppressed in stickiness of the protective film and had a good appearance.

  The glass tube for a light bulb shaped lamp of the present invention has a scratch-resistant surface, good scratch resistance, and hardly adheres to the surface, and requires an excellent appearance quality, such as an incandescent light bulb, a light bulb shape. It is useful as a glass tube for various bulb-type lamps such as fluorescent lamps and bulb-type LED lamps.

Sectional drawing in an example of the glass tube for light bulb shaped lamps of this invention (A) The conceptual diagram which looked at the measuring apparatus of the sliding angle in the glass tube for light bulb shaped lamps of this invention from the upper part, (b) The conceptual diagram explaining the measuring method of a sliding angle Conceptual diagram explaining the method of measuring the glass strength in a glass tube for a light bulb shaped lamp

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Glass tube for bulb-type lamp 12 Glass bulb 12a Neck part 12b Expansion part 14 Protective film 16 Interface

Claims (9)

And glass bulb bulb made of glass composition comprising 10-25 wt% of _Na 2 O, and 0.1 to 5 wt% of _{K 2} O,
A protective film comprising a nonionic surfactant having an HLB value of 8 or more and provided so as to cover a part or all of the outer surface of the glass bulb;
And a glass tube for a light bulb shaped lamp characterized by having a sliding angle of 25 ° or less. The glass tube for a light bulb shaped lamp according to claim 1, wherein the nonionic surfactant is a substance represented by the following formula (1).
R—O— (EO) _n —H (1)
[In the formula, R represents a linear alkyl group having 12 to 18 carbon atoms; n represents an average addition mole number and represents an integer of 4 or more; EO represents an ethyleneoxy group (CH ₂ CH ₂ O) Represents] A method for producing a glass tube for a light bulb shaped lamp having a protective film formed on an outer surface,
Preparing a glass bulb for a bulb made of glass composition comprising 10-25 wt% of _Na 2 O, and 0.1 to 5 wt% of _{K 2} O,
Applying an aqueous solution to a part or all of the outer surface of the glass bulb so that the application amount of a nonionic surfactant having an HLB value of 8 or more is 0.002 μg / cm ² or more;
Drying the wet film obtained by the coating to form a protective film;
A method for producing a glass tube for a light bulb shaped lamp, comprising: The method for producing a glass tube for a light bulb shaped lamp according to claim 3, wherein the coating amount of the nonionic surfactant is 0.3 µg / cm ² or less. 5. The step of applying an aqueous solution to the outer surface of the glass bulb is a step of spraying an aqueous solution containing the nonionic surfactant onto the heated outer surface of the glass bulb. The manufacturing method of the glass tube for bulb-type lamps as described in 2. The said nonionic surfactant is a substance represented by following formula (2), The manufacturing method of the glass tube for light bulb shaped lamps as described in any one of Claims 3-5 characterized by the above-mentioned.
R—O— (EO) _n —H (2)
[In the formula, R represents a linear alkyl group having 12 to 18 carbon atoms; n represents an average addition mole number and represents an integer of 4 or more; EO represents an ethyleneoxy group (CH ₂ CH ₂ O) Represents] 6. The method of manufacturing a glass tube for a light bulb shaped lamp according to claim 5, wherein the step of forming the protective film is a step of drying the wet film by heat of the heated glass bulb. The molten glass composition is molded as a raw material, the aqueous solution is applied to the outer surface of the glass bulb where heat during molding remains, and the wet film is dried by the heat remaining in the glass bulb. Item 8. A method for producing a glass tube for a bulb-type lamp according to Item 7. The method for manufacturing a glass tube for a light bulb shaped lamp according to claim 7 or 8, wherein the temperature of the outer surface of the glass bulb immediately before the aqueous solution is applied is 100 to 450 ° C.

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