JPH0446911B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Field of Application] The present invention relates to an ultraviolet absorbing glass composition for glass fibers used to strengthen plastic substrates used as printed circuit boards, and in particular to ultraviolet absorbing glass compositions for glass fibers used to strengthen plastic substrates used as printed circuit boards. The present invention relates to a glass composition in which ultraviolet absorption properties are imparted to alkali borosilicate glass. [Prior Art] When obtaining a cured solder resist pattern using the photoresist method for a printed circuit in which the substrate is a laminate using a glass fiber sheet-like base material as a reinforcing material and circuits are formed on both sides of the laminate, the laminate is used as a reinforcing material. Since the board does not have UV-blocking properties, if UV-curable solder resist is placed on both sides and UV irradiation is applied from both sides at the same time, the transmitted UV rays will harden the areas other than the required pattern on each side. Simultaneous irradiation on both sides cannot be performed because this results in an inaccurate cured resist pattern. In order to solve this problem, a method of attaching titanium oxide to the surface of the glass fibers constituting the glass fiber sheet-like base material was proposed in Japanese patent application No. 113809/1986.
It is proposed in the specification of No. However, the process becomes complicated because titanium oxide is attached to the glass fiber sheet in a post-process, increasing manufacturing costs. There were disadvantages such as the tendency for abnormalities to occur. [Problems to be Solved by the Invention] In order to overcome the drawbacks of the conventional methods as described above, the purpose of the present invention is to provide ultraviolet absorbing properties to the glass fibers themselves constituting the glass fiber sheet and to block ultraviolet rays. , which attempts to enable simultaneous ultraviolet irradiation on both sides using the photoresist method. Conventionally, as ultraviolet absorbing glass, colorless soda-lime glass (Japanese Patent Laid-open _{No. 1983-1999-}
No. 47811), ultraviolet cut filter glass doped with Au, SnO, As ₂ O ₅ , CeO ₂ , etc.
67313), borosilicate hard glass containing V ₂ O ₅ (Japanese Patent Application Laid-Open No. 160938/1983), etc., but the soda lime glass mentioned above has a high content of alkali oxides such as Na ₂ O. Therefore, it cannot be used for electrical-related laminates, which require the content of alkali oxide in the glass fiber to be 0.8%. The above-mentioned ultraviolet cut filter glass for optical use is required to cut out ultraviolet rays and at the same time absorb wavelengths around 550 mμ, which is not suitable for the purpose of the present invention. In addition, borosilicate hard glass has SiO ₂ of 65
% or more, the melting temperature becomes high and it cannot be spun into glass fibers, so it cannot be used as a raw material for the glass fibers targeted in the present invention. [Means for solving the problem] As a result of conducting research to obtain a raw material for glass fiber that is suitable for manufacturing glass fiber and has good ultraviolet absorption performance, the present inventors have found that the most common raw material for glass fiber manufacturing is "E glass" used in
Fe ₂ O ₃ in alkali-free borosilicate glass called
It has been found that by adding , it is possible to impart the ultraviolet absorption performance required by the present invention. However, even if only Fe ₂ O ₃ is added to borosilicate glass, most of it will be in the form of FeO in the high-temperature molten state, which will cause the glass fabric to be colored blue, and the surface layer of the molten glass will not absorb infrared rays well. It was found that the radiant heat had difficulty reaching the bottom of the glass layer, which lowered the temperature of the lower layer of the molten glass in the tank furnace, hindering melting and making production difficult. Therefore, Fe ³⁺ , which has good transmittance of visible light and absorbs ultraviolet rays, is increased, and Fe ²⁺ , which is the cause of coloring of glass fabric, is increased.
As a result of investigating additives that can reduce UV rays and coexist with Fe ³⁺ to improve UV absorption performance, we found that compared to conventional alkali-free borosilicate glass, the additives have improved strength, durability, electrical properties, We succeeded in significantly improving the UV transmittance at 360 nm to less than 1/10 without reducing general physical properties such as visible light transmittance. The ultraviolet absorbing glass composition for fibers of the present invention contains 52 to 56% SiO ₂ and Al ₂ O ₃ , respectively expressed in weight%.
12-16%, _{B2O3 6-11} %, CaO 16-25%,
0.1 to 0.4 parts by weight of Fe ₂ O ₃ and 0.05 to 4.0 parts of CeO 2 to 100 parts by weight of an alkali-free borosilicate glass composition consisting of 0 to 6% MgO, but 18 to 25% CaO ₊ MgO. , _0.05-0.5 part MnO2,
One selected from the group consisting of 0.2 to 0.5 parts of As ₂ O ₅ or CeO ₂ + 0.1 to 4.5 parts of As ₂ O ₅ , CeO ₂ + Na ₂ NO ₃
The glass composition is characterized in that it is obtained by further adding and melting 0.1 to 4.5 parts of one selected from the group consisting of 0.1 to 4.5 parts, and that Na ₂ O is 0.8% by weight or less of the obtained glass composition. In the above composition, if Fe ₂ O ₃ is less than 0.1 part by weight, absorption of ultraviolet rays is weak, and if it is more than 0.4 part by weight, it not only becomes more colored than conventional glass, but also causes problems in melting the glass. Shikami, Fe ₂ O ₃
However, the disadvantage is that it is difficult to control the ratio of Fe ²⁺ and Fe ³⁺ and the performance tends to vary.
When CeO ₂ coexists with Fe ₂ O ₃ , if it is less than 0.05 parts by weight, it will transmit ultraviolet rays, and if it is more than 4.0 parts by weight, it will absorb visible light and become colored. _MnO2
When coexisting with Fe ₂ O ₃ , MnO 2 strengthens the absorption of ultraviolet rays and at the same time colors MnO ₂ pink, and since it has a complementary color relationship with the coloring of FeO, the coloring is weakened. In particular, the weight ratio with Fe ₂ O ₃ is MnO ₂ :Fe ₂ O ₃ = 1:1.85.
(equimolar), the average transmittance is improved. If it is less than 0.05 part by weight, there will be no effect, and if it exceeds 0.5 part by weight, the coloring of manganese will become stronger and the average transmittance will decrease. When As ₂ O ₅ coexists with Fe ₂ O ₃ ,
If it is less than 0.2 parts by weight, there is no effect, and if it exceeds 0.5 parts by weight, the coloring will be strong. CeO ₂ + NaNO ₃ and
When Fe ₂ O ₃ or CeO ₂ + As ₂ O ₅ coexists with Fe ₂ O ₃ , the average transmittance does not decrease compared to the combination of one type of additive and Fe ₂ O ₃ , and the ultraviolet rays are further enhanced. Increase absorption. In any case, if it is less than 0.1 part by weight, there is no effect, and CeO ₂ + NaNO ₃ ,
In both combinations of CeO ₂ +As ₂ O ₅ , if CeO ₂ is 4.0 or more and the total additive exceeds 4.5 parts by weight, the average transmittance will decrease, which is not preferable. Generally, alkali-free borosilicate glass for glass fiber is required to have an alkali content of 0.8% by weight or less, so _NaNO3 is not included in the glass.
Since it converts into Na ₂ O, the amount added is limited to a maximum of 0.5 parts by weight. At this amount, even if it is coexisting with Fe ₂ O ₃ alone, the effect of converting Fe ²⁺ to Fe ³⁺ is weak. but,
When used in combination with CeO ₂ and As ₂ O ₅ , a synergistic effect can be enhanced. [Example] A raw material mixture was prepared by adding and mixing the ultraviolet absorbing components shown in Table 1 to 100 parts by weight of alkali-free borosilicate glass having the following standard composition as a sample, and heating and melting at a temperature of 1500°C. After completely dissolving the raw material mixture, it was poured into a mold and slowly cooled at 600°C. This plate-shaped sample had a size of 40 x 10 x 8 mm thick, and after mirror polishing both sides, it was manufactured by Hitachi, Ltd.
360 nm and 228-inch double beam spectrophotometer
The average transmission from 400 to 780 nm was measured. Composition of alkali-free borosilicate glass used (wt%) SiO ₂ 54.5 Al ₂ O ₃ 14.0 CaO 23.5 B ₂ O ₃ 8.0

【table】

[Table] In Table 1, the comparative example is a case where only an alkali-free borosilicate glass composition, which is a raw material for commercially available long glass fibers, is used. What does it say “3 types”?
It means a combination of Fe ₂ O ₃ and two of CeO ₂ , As ₂ O ₅ and NaNO ₃ . It is empirically known that it is suitable for the present invention if the transmittance at 360 nm is 1/10 or less than that of alkali-free borosilicate glass (comparative example), and the average transmittance at 400 nm to 780 nm is at least 1/10 that of non-alkali borosilicate glass (comparative example). From Table 1 the compositions suitable for the present invention are clear, since a higher than that of the example is necessary for the soaked melting of the glass. That is,
For example, in Experimental Example 1, the average transmittance is sufficient, but
The transmittance at 360nm is too high, and Experimental Example 4
Although the transmittance at 360 nm is sufficient, the average transmittance is too low. Experimental Example 10 had insufficient transmittance, but was strongly colored and unsuitable. Figure 1 shows the relationship between the transmittance at 360nm and the amount added.
This is a semi-log graph based on the Lambert-beer law. According to this, as an example of the relationship between the amount of each additive component added and the transmittance at 360 nm, Fe ₂ O ₃
Looking at the case where only Fe 2 O ₃ is added, the change in ultraviolet absorption rate depending on the amount of Fe ₂ O 3 is rapid, indicating that it is difficult to control the ultraviolet absorption rate at a constant level in the manufacturing process. The graph shows that the change is gradual and that the ultraviolet absorption rate can be easily controlled. [Effects of the Invention] Compared to alkali-free borosilicate glass, the glass of the present invention has a transmission limit wavelength and an average transmittance of the same level, and furthermore, the ultraviolet transmittance of 360 nm is about 1/10 of that of alkali-free borosilicate glass. To make Fe ³⁺ ,
Ce ³⁺ ions are effective. Fe usually coexists in the form of Fe ²⁺ and Fe ³⁺ in alkali-free borosilicate glass, but Fe ²⁺ has absorption near the infrared;
(colors from blue to blue-green), Fe ³⁺ is colorless and transmits visible light, but absorbs in the ultraviolet region, so CeO ₂ ,
When oxidizing substances such as As ₂ O ₅ , MnO ₂ , and NaNO ₃ coexist with Fe ²⁺ , 2FeO + 2CeO ₂ →Fe ₂ O ₃ +Ce ₂ O ₃ 2FeO + 2TiO → Fe ₂ O ₃ +Ti ₂ O ₃ 2FeO + 2MnO ₂ →Fe ₂ O ₃ +Mn ₂ O ₃ 4FeO+As ₂ O ₅ →2Fe ₂ O ₃ +As ₂ O ₃ 6FeO+NaNO ₃ →3Fe ₂ O ₃ +Na ₂ O+2NO ₂ Reacts as follows, becomes Fe ²⁺ →Fe ³⁺ , and Fe ^{2 The} average transmittance increases because the amount of Fe 3+ ions decreases and the amount of light absorbed in the visible range decreases, and the amount of Fe ³⁺ ions increases, which strengthens the absorption of ultraviolet rays. Ultraviolet transmittance can be 1/10 or less of alkali-free borosilicate glass.

[Brief explanation of drawings]

Figure 1 shows the relationship between the transmittance at 360nm and the amount of addition.
This is a semi-log graph based on the Lambert-beer law.

Claims (1)

[Claims] 1. SiO ₂ 52-56 Al ₂ O ₃ 12-16 B ₂ O ₃ 6-11 CaO 16-25 MgO 0-6, each expressed in weight %. Alkaline borosilicate glass composition 100
One type selected from the group consisting of Fe ₂ O ₃ 0.1 to 0.4, CeO ₂ 0.05 to 4.0 MnO ₂ 0.05 to 0.5 As ₂ O ₅ 0.2 to 0.5, or CeO ₂ +As ₂ O ₅ 0.1 to 4.5 CeO ₂ + one selected from the group consisting _of NaNO ₃ 0.1 to 4.5.
% or less by weight.