JPS62252051A - Cathode-ray tube - Google Patents

Abstract

PURPOSE:To eliminate a defect of the picture screen from the lens effect resulting from the styrene single polymerization, and also avoid the interface break away from the panel and the generation of resin cracks, even though an unsaturated polyester resin is used as a bond, by controlling a (styrene)n- dibutyl fumarate reaction product after a hardening process, between 0.005 and 2.5 wt%. CONSTITUTION:Defects produced by the lens effect when an unsaturated polyester resin is used as a bond can be roughly classified into two types, a hardening unevenness or a linear defect (stria) from the hardening deformation, and a spot defect of the polystyrene produced by the styrene sigle polymerization or the like. In the latter defect case, by controlling the content of (styrene monomer)n-dibutyl fumarate reaction product (n = 2 to 8) after the hardening process, restricting the content 0.005 to 2.5 wt%, a favorable property to prevent the generation of the picture screen defect and as a bond can be obtained. In other words, by setting the content of the hardening agent at 1 to 3 wt%, the hardening temperature at 60 to 120 deg.C, and the hardening time within three hours, for example, the content of the reaction product can be controlled at a desired value.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a cathode ray tube, and particularly to a cathode ray tube in which a transparent front panel is bonded to the front surface of the face plate of the main body.

[Conventional technology]

A structure in which a front panel is attached to the front surface of the face plate of the cathode ray tube body via an adhesive layer has been manufactured in many cases as front-reinforced cathode ray tubes. A front non-reflective cathode ray tube has been proposed (for example, Japanese Patent Publication No. 172851/1983).

In a cathode ray tube having such a structure, the face plate v
As the adhesive inserted between the front panel and the front panel, a curable adhesive such as unsaturated polyester resin or epoxy resin is used.

[Problem that the invention seeks to solve]

However, in a cathode ray tube with such a structure, curing strain occurs in the adhesive layer, resulting in linear defects (striae), which appear on the screen as a lens effect during operation of the cathode ray tube, and deteriorate the image quality. This problem has become even more problematic because high definition is required for cathode ray tubes used for display terminals and the like.

In addition to these drawbacks, there were other problems such as interfacial peeling of the adhesive layer and cracking of the adhesive layer (hereinafter referred to as range cracking).

SUMMARY OF THE INVENTION An object of the present invention is to provide a high-quality cathode ray tube free from screen defects due to lens effects, interfacial peeling, and range cranking.

[Means for solving problems]

In order to solve the above problems, the present invention uses an unsaturated polyester resin as an adhesive, and as a composition after the curing reaction of this resin, 0.005 to 2.5 wt% of (styrene monomer) n-dibutyl fumarate is reacted. It is specified that it contains substances (n=2 to 8).

Defects due to the lens effect that occur when unsaturated polyester resin is used as an adhesive are mainly linear defects (striae) caused by uneven curing and curing distortion caused by uneven curing temperature, and linear defects (striae) caused by unsaturated polyester resin. Polystyrene V/ produced by homopolymerization of styrene contained in
The refractive index of polyester resin is larger than that of unsaturated polyester resin, and spot-like defects are generally classified into these. this house,
The former can be dealt with by making the curing temperature uniform, but the latter is problematic due to the behavior of the styrene monomer, which is generally added at 20 to 30 wt% to carry out the crosslinking reaction for the purpose of curing the unsaturated polyester resin. And the solution was not easy.

In contrast, the inventors have discovered that by controlling the content of the (styrene monomer) rhodibutyl fumarate reactant (n = 2 to 8) after the curing reaction of the unsaturated polyester resin, the homopolymerization of styrene can be suppressed. As a result of various studies focusing on roses, it was found that the content of (styrene monomer) n-dibutyl fumarate reactant (n-2 to 8) of 0.005 to 2.5 wt% can prevent the occurrence of screen defects and can be used as an adhesive. It has been found that favorable results can be obtained in terms of properties as However, after curing approximately 100% (styrene monomer), the content of the n-dibutyl 7-malate reactant (n = 2 to 8) was o,
If it is less than o o swt%, the hardness and adhesive strength will increase, but the flexibility will be poor, and when exposed to high temperature E, etc.
This may cause delamination at the interface with the face plate or front panel or resin cracks. Further, the content is 2.5wt
%, there is a problem that screen defects may occur after being left alone as will be described later.

[Effect]

After curing reaction of unsaturated polyester resin (styrene monomer) n-')-j chill 7 Murray) reactant (n-2~
By specifying the content of 8), homopolymerization of styrene is suppressed and screen defects are prevented.

〔Example〕

In the present invention, the content of the n-dibutyl fumarate reactant (n-2 to 8) (styrene monomer) after the curing reaction is set to 0.00.
The content was determined to be 5 to 2.5 wt %, and the experiment that led to this conclusion will be explained.

First, the n-dibutyl fumarate reaction product (styrene monomer) after the curing reaction of the unsaturated polyester resin (n = 2 to 8
) The content was measured by the following method.

That is, 5 g of the resin after curing is taken, and 15 g of acetone is added thereto. This is left to stand at room temperature for 15 hours or more, and the (styrene monomer) n-dibutyl fumarate reactant is extracted into acetone. Next, this acetone was subjected to gel permeation chromatography to determine the area of the chart of the (styrene monomer) n-dibutyl fumarate reaction product, and this was compared with a calibration curve prepared in advance using standard samples. Styrene monomer) n-dibutyl 7 malate The weight percent of the reactant is determined.

When we investigated the relationship between the content of the n-dibutyl fumarate reactant (styrene monomer) measured in this way and the properties of the resin, we found that the content of the n-dibutyl 7-malate reactant (styrene monomer) was If it exceeds 2.5 wt %, linear defects occur when the film is left to stand, and lens effects (screen defects) occur.

On the other hand, if the curing reaction is allowed to proceed until the content of the (styrene) n-dibutyl fumarate reactant is less than 0.005 wt%, for example, approximately Qwt, the safety standards from the viewpoint of fat bombing, etc. If the resin is left at a certain temperature of 149°C for 48 hours, cracks will appear in the resin. This is thought to be due to the fact that the resin, which has undergone the crosslinking reaction to the limit, is further heated, which in turn causes a decomposition reaction.
) The reactants should not be too much, but 0.005wt%
It is safe to include the above.

The relationship between the content of such (styrene) n-dibutyl 77V-) reactant and the adhesive strength of the resin is shown in Figure 5.
Similarly, the relationship with the number of defects in the resin is shown in #¥6ku,
From these experimental results, we found that (styrene) n
-Content of dibutyl fumarate reactant is 0.0 O5 ~
2.5 wt%, preferably 0. OO5~2wt
It is Chi.

In this way, in order to contain the (styrene) n-dibutyl fumarate reactant at 0.05 to 2.5 wt%, +
The amount of Il curing agent added is 1 to 3 wt%.

(2) Set the curing temperature to 60 to 120°C.

r3) Curing time is within 3 hours.

The following methods are effective, and by appropriately combining these methods, the content of the (styrene) n-dibutyl fumarate reactant can be controlled to a desired value.

Embodiments of the present invention will be specifically described below with reference to the drawings.

FIG. 1 is a front view showing an embodiment of the present invention, in which an adhesive resin 3 is placed on the front surface of a face plate 2 of a cathode ray tube body 1.
A front panel 4 made of non-reflective transparent glass is adhered. This embodiment is an example applied to a shadow mask type color cathode ray tube, and as the cross section is shown in FIG. It is arranged.

Here, the adhesive resin 3 is made of an unsaturated polyester resin and has about 1.5 wt t4 of (styrene) n-dibutyl fumarate reactant.

Next, a method for manufacturing a color cathode ray tube having such a configuration will be described with reference to FIGS. 3 and 4. First, the face plate 2 of the cathode ray tube body 1 manufactured by a well-known method is oriented upwardly as shown in FIG. 3, and the spacer 5 is placed around the periphery. Further, the upper part of this spacer 5 and the front panel 4 are arranged to face the face plate 2, and a tape 6 made of a synthetic resin material is wrapped around the surface. At this time, an injection port 8 connected to a gap 7 formed between the face plate 2 and the front panel 4 is provided in a part of the tape 6. Next, this cathode ray tube main body 1 is
While preheating at a temperature of 45°C, as shown in FIG. ; Methyl ethyl ketone peroxide) is supplied in a predetermined amount into the dispenser 13, thoroughly stirred by the mixer 14, and then injected from the injection port 8 via the injection jig 15.

Unsaturated polyester resin liquid (contains unsaturated ester) Styrene 25 wt% Cobalt naphthenate 0.02 wt% The curing agent was added at 2 wt% based on the total weight.

After the resin liquid completely fills the gap 7, the entire cathode ray tube body 1 is heated at 80° C. for 3 hours to harden the resin liquid.

When the content of the (styrene) n-dibutyl fumarate reactant was measured in the unsaturated polyester resin after curing using the method described above, it was approximately 1.3 wt%.
It was confirmed that the cathode ray tube manufactured as in C did not cause interfacial peeling from the panel or resin cracks even in the 120° C. high temperature storage test, and could be stably mass-produced and supplied as a product.

Furthermore, by adding an unsaturated polyester resin (an oligomer (unsaturated ester)), the rate of decrease over time of the (styrene) n-dibutyl fumarate reactant after curing can be slowed down. For example, as mentioned above. Using a solution in which 10 wt% of oligomer was added to the unsaturated polyester resin liquid having the composition, it was cured in the same manner as described above, and the subsequent change in the amount of (styrene) n-dibutyl fumarate reactant was observed. It can be seen that the rate of decrease of the (styrene) n-dibutyl fumarate reactant is significantly slower than when it is not added. When the (styrene) n-dibutyl fumarate reactant becomes less than 0.005 wt%,
As mentioned above, there is a risk of interfacial peeling from the panel and resin cracks when heated to high temperatures, but adding oligomers has the advantage of maintaining the effect for a long time.

In the above, a case was explained in which an unsaturated polyester resin liquid containing 25 wt% of styrene was used, but the present invention is not limited to this, and the amount of styrene added may be varied within the commonly used range of 20 to 3 Qwt%. However, the same effect can be obtained by appropriately selecting the amount of the curing agent, curing temperature, and curing time to control the amount of (styrene) n-dibutyl fumarate reactant after curing.

〔Effect of the invention〕

As explained above, according to the present invention, the (styrene) n-dibutyl 7-maleate reactant after curing is
, 5 wt%, while using the unsaturated polyester resin as an adhesive, it is possible to eliminate screen defects due to the lens effect caused by homopolymerization of styrene, and to reduce the amount of (styrene)n-dibutyltuma v-) reactant. By including it, that is, by not setting the content to 0w1%, it is possible to avoid interfacial peeling with the panel and occurrence of resin cracks.

In addition, although the above description was made regarding the (styrene) n-dibutyl 7-maleate reactant, instead of this, (styrene monomer dibutyl fumarate) n (11ex
2 to 5'l to 2.5 wt% or less (zero 41 division < )
A similar effect can be obtained even if the

[Brief explanation of drawings]

Figure 1 is a front view of a cathode ray tube showing an example of a misfire, Figure 2 is a cross-sectional view, Figures 3 and 4 are diagrams for explaining the manufacturing method, and Figure 5 is after curing. Resin residue (
Figure 6 shows an example of the relationship between the amount of n-dibutyl fumarate reactant and adhesive strength.
-Dibutyl 77v- It is a diagram showing an example of the relationship between the amount of reactant and the number of defects. 1... Cathode ray tube body, 1a... Panel,
2...Face plate, 3...Adhesive resin, 4...Front panel. 111! iI Figure 2 Figure 5 (Styrene 1n-3") nalfumarate anti-yatsu@41
[”wL%] Figure 6

Claims (1)

[Claims] 1. In a cathode ray tube in which a non-reflective transparent front panel is bonded to the front surface of the phase plate of the cathode ray tube body using resin, an unsaturated polyester resin is used as the bonding resin, and the resin after curing reaction is 0.005 ~2.5wt
% of (styrene monomer) n-dibutyl fumarate reactant (n=2 to 8).