JPH0425229B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Use) The present invention relates to a coating material for optical fibers, and particularly to a coating material for coating quartz fibers for optical communications. (Prior art) Various types of optical communication fibers are known, such as quartz-based, multi-component glass-based, and plastic-based fibers, but in reality, their lightness, low loss, non-induction, heat resistance, Quartz-based materials have been put into practical use due to their weather resistance and transmission capacity. However, since the quartz-based material is extremely thin and easily deteriorates over time, its surface is coated with an appropriate material. As a coating material, silicone has low temperature dependence, can be used over a wide temperature range, is effective in maintaining strength and relieving stress, and is also less likely to cause transmission loss due to microbending and less likely to generate noise due to scattering. The use of resin is considered preferable. However, silicone resins currently in practical use mainly consist of organopolysiloxanes containing a vinyl group [≡Si (CH=CH ₂ ) group] bonded to a silicon atom in the molecule and hydrogen bonded to a silicon atom in the molecule. This is an addition reaction method with organohydrodiene polysiloxane containing atoms (≡SiH bonds), and from the viewpoint of the properties and curability of the cured silicone resin, ≡Si (CH= It is said that the amount of ≡SiH bonds in the organohydrodiene polysiloxane relative to the CH ₂ ) group is blended so that ≡Si(CH=CH ₂ )/≡SiH<1, so after the addition reaction, ≡SiH bonds remains, which reacts with moisture in the air to form hydrogen gas, which has the drawback of increasing the transmission loss of the glass fiber. (Structure of the Invention) The present invention relates to an optical fiber coating material that solves the above-mentioned disadvantages _.
2) has at least two hydrogen atoms (≡SiH bonds) bonded to silicon atoms in one molecule;
The molar ratio of ≡Si (CH=CH ₂ ) groups to ≡SiH bonds in the first component is ≡Si (CH=CH ₂ ) groups/≡SiH≧1, and the amount of ≡SiH bonds in the first component is and 3) an organohydrodiene polysiloxane in an amount that provides 0.05 mole or less per 100 g of the total amount of the second component, and 3) a platinum-based addition reaction catalyst. To explain this, the present inventors have conducted various studies on the development of optical fiber coating materials that can suppress the generation of hydrogen gas when coated on optical fibers. Vinyl group inside [≡
The molar ratio of the Si (CH=CH ₂ ) group] to the hydrogen atom [≡SiH bond] in the organohydrodiene siloxane, where ≡Si(CH=CH ₂ )/≡SiH is 1 or more than 1, in the addition reaction product. It was discovered that the remaining ≡SiH bonds should be minimized, and the amount of organohydrodiene siloxane should be such that the amount of ≡SiH bonds is 0.05 mol or less per 100 g of the total amount of these siloxanes. The present invention was completed. Organopolysiloxane as the first component constituting the coating material of the present invention is well known in the art and has at least two vinyl groups [≡Si (CH=CH ₂ ) groups] bonded to silicon atoms in one molecule. It is usually considered to be a linear organopolysiloxane with a vinyl group at the end of the molecular chain, but the vinyl group is not limited to the end of the molecular chain, but is included in the side chain of the molecule. It may be contained in both the molecular chain terminal and the molecular side chain. In addition, organic groups other than vinyl groups bonded to silicon atoms in this organosiloxane include alkyl groups such as methyl, ethyl, propyl and butyl groups, aryl groups such as phenyl and tolyl groups, cyclohexyl groups, The same or different unsubstituted or Substituted monovalent hydrocarbons are defined as those containing at least two ≡Si (CH=CH ₂ ) groups in their molecules, and their molecular structure is linear, branched, cyclic, or It may be either in the form of a net, or may be used alone or in a mixture of two or more. This organopolysiloxane has the following formula: (where a, b, c, d, e, f, g, h, i are positive integers) are exemplified, but this also includes, for example, methylsiloxane units (CH ₃ SiO _1.5
unit) 70 mol%, methylvinylsiloxane unit [CH ₃ (CH=CH ₂ )SiO unit] 10 mol%, dimethylsiloxane unit [(CH ₃ ) ₂ SiO unit] 20 mol%
37 mol% of trimethylsiloxy units [(CH ₃ ) ₃ SiO _0.5 units], dimethylvinylsiloxy units [(CH ₃ ) ₂ (CH=CH ₂ )SiO _0.5 units]
It may be an organosiloxane copolymer consisting of 16 mol% and 47 mol% of SiO ₂ units.
These organopolysiloxanes can be prepared by cohydrolyzing a mixture of corresponding organosilanes, or by performing an equilibrium reaction between a disiloxane containing the terminal group and a cyclic polysiloxane in the presence of an alkali catalyst. However, the viscosity at 25℃ is
It can be anything from a low viscosity of 0.7cS to a solid with a high degree of polymerization, and solids can be dissolved in other liquid organopolysiloxanes or dissolved in benzene, toluene, etc. It can be used dissolved in a solvent. Next, the organohydrodiene polysiloxane used as the second component may be one well known in the art, but this one contains at least two hydrogen atoms bonded to silicon atoms (≡SiH bonds) in one molecule. It is necessary to do so. This ≡SiH bond may be included at the end of the molecular chain or in the side chain, but it is necessary to react with the vinyl group in the first component to give a cured product. Therefore, if there are only two vinyl groups in the first component, there must be at least three vinyl groups in the second component, and if there are only two vinyl groups in the second component, there must be at least three vinyl groups in the second component. It is necessary that there be at least three vinyl groups in one component. The organic group other than the ≡SiH bond in the second component may be the same or different type of unsubstituted or substituted monovalent hydrocarbon group as the organic group other than the vinyl group in the first component. The molecular structure of this organohydrodiene polysiloxane may be linear, branched, cyclic, or network-like, and may be used alone or in a mixture of two or more types. formula (j, k, l are each 0 or a positive integer) Examples include those shown by ≡SiH bond. It is preferable that the compound exists in the molecule in the following form, and therefore the compound represented by the following formula is preferable. (m, n are positive integers) The amount of the second component to be added to the first component depends on the amount of ≡Si (CH=CH ₂ ) groups in the first component and the amount of ≡SiH bonds in the second component. However, since this is to minimize the number of ≡SiH groups remaining after the reaction is completed, ≡Si(CH=CH ₂ )/≡SiH≧1
(molar ratio), but from the viewpoint of preventing an increase in optical fiber transmission loss due to the presence of hydrogen gas caused by ≡SiH bonds, this second It has been experimentally confirmed that the amount of ≡SiH bonds in the components is preferably 0.05 mol or less per 100 g of the total weight of the first and second components. Further, examples of the addition reaction catalyst as the third component include platinum, rhodium, palladium, nickel, and compounds thereof, and platinum compounds which are usually most commonly used commercially may be used. Examples of platinum compounds include chloroplatinic acid, alcohol-modified chloroplatinic acid, and complex salts of chloroplatinic acid and olefin. It is often used in dissolved form, and the amount used is in accordance with the above-mentioned
0.1 to total weight of component and second component
It may be within the range of 20ppm. The optical fiber coating material of the present invention includes the above-described first to
The third component is obtained by uniformly mixing a predetermined amount of the third component, but if necessary, the third component is substantially free of addition reaction catalytic ability in order to adsorb hydrogen gas remaining in the addition reaction product. platinum, rhodium, palladium and their compounds, such as platinum powder,
Platinum asbestos, platinum barium cyanide, platinum black, platinum dichloride, potassium chloroplatinate, rhodium powder, rhodium acetylacetone, rhodium chloride,
Rhodium oxide, palladium powder, palladium acetate, palladium asbestos, palladium black, palladium chloride, or these powders supported on carriers such as silica, alumina, calcium carbonate, and fine powders of alloys of these are added. For example, powders of these metals and alloys may be
It is desirable to add it in the form of a fine powder of 5 μm or less. In addition, a reaction control agent such as a compound containing phosphorus, nitrogen, or sulfur or an acetylene compound may be added to this coating material in order to control the addition reaction between the first component and the second component. Inorganic fillers such as fumed silica, zinc carbonate, and titanium oxide, and pigments may also be added. Next, examples of the present invention will be given. Examples 1 to 1
4. Comparative Example 1 uses this composition as a primary, Examples 5 to 7 and Comparative Example 2 use this composition as a buffer, and parts in the examples refer to parts by weight. Viscosity is a value measured at 25°C. Examples 1 to 3 25 mol% of phenyl group and 0.04% of vinyl group, with the molecular chain end capped with dimethylvinylsiloxy group
100 parts of methylphenylpolysiloxane with a viscosity of 2000cS containing mol%, 2.4 parts of methylhydrodienepolysiloxane containing 1.6mol/100g of ≡SiH bonds, an octyl alcohol modified solution of chloroplatinic acid (platinum content 2%) 0.5 parts of the silicone-modified acetylene alcohol were added and mixed uniformly to prepare a composition. In addition, instead of the octyl alcohol modified solution of chloroplatinic acid in the above, a composition was prepared by adding 0.05 part of the same solution and 0.011 part of platinum oxide powder, and further, in place of the methylhydrodiene polysiloxane in the above, the formula [H(CH ₃ ) 6.0 parts of methylphenylhydrodiene polysiloxane containing 0.63 mol/100 g of ≡SiH bonds represented by ₂ SiO _{0.5 7} [C ₆ H ₅ SiO _1.5 ] ₅ was added to prepare a composition. Example 4 Formula It is indicated by. 25 mol% phenyl group, vinyl group
100 parts of methylphenyl polysiloxane with a viscosity of 2000cS containing 0.06 mol%/100g, 3.7 parts of methylhydrodiene polysiloxane containing 1.6 mol/100g of ≡SiH bonds, an octyl alcohol modified solution of chloroplatinic acid (platinum content 2 %) and 0.015 parts of palladium powder were added and mixed uniformly to form a composition. Example 5 0.53 ≡SiH bonds were added to 100 parts of dimethylpolysiloxane containing 0.007 mol/100 g of vinyl groups whose molecular chain ends were capped with dimethylvinylsiloxy groups.
1.2 parts of methylhydrodiene polysiloxane containing mol/100g, 1,3-divinyltetradimethyldisiloxane-platinum complex (platinum content 2%)
1.5 parts of acetylene alcohol and 1.5 parts of a siloxane-modified product of acetylene alcohol were added and mixed uniformly to form a composition. Examples 6 to 7 To 100 parts of dimethylpolysiloxane having a viscosity of 3000 cS and containing 0.007 mol/100 g of vinyl groups, the molecular chain terminals of which are capped with dimethylvinylsiloxy groups,
(CH ₃ ) ₃ SiO _0.5 units, (CH ₂ =CH) (CH ₃ ) ₂ SiO _0.5 units and 40 parts of a copolymer of SiO ₂ units in a molar ratio of 1.0:0.15:1.0, ≡SiH bonds of 0.53 mol/ 8.0 parts of methylhydrodiene polysiloxane containing 100g;
1,3-divinyl-tetramethyldisiloxane-
Platinum complex salt (platinum content 2%) 0.05 part, rhodium powder
Add 0.015 part of siloxane modified product of acetylene alcohol and _0.05 part of siloxane _modified product of _acetylene alcohol and mix uniformly to make _a composition. Molar ratio of copolymer (≡SiH bond content 1.2
A composition was prepared with the same composition as above except that the amount was 2.5 parts (mol/100 g). Comparative Example 1 25 mol% phenyl group and 0.04 mol% vinyl group, with the molecular chain end capped with dimethylvinylsiloxy group.
100 parts of methylphenylpolysiloxane with a viscosity of 2000 cS containing moles/100g, 3.8 parts of methylhydrodiene polysiloxane containing 1.6 moles/100g of ≡SiH bonds, and an octyl alcohol modified solution of chloroplatinic acid (platinum content 2%) 0.05 1 part and 0.05 part of a silicone modified version of acetylene alcohol were added to form a composition. Comparative Example 2 _0.5 units of (CH ₃ ) ₃ SiO, (CH ₂ =CH) (CH ₃ ) ₂ SiO _0.5 units and SiO ₂
40 parts of a copolymer (vinyl group content 0.1 mol/100 g) with a molar ratio of 1.0:0.15:1.0, ≡SiH bond
12.5 parts of methylhydrodiene polysiloxane containing 0.53 mol/100g, 1,3-divinyltetramethyldisiloxane-platinum complex salt (platinum content 2%)
0.1 part and 0.1 part of silicone modified acetylene alcohol were added and mixed uniformly to form a composition. (Measurement of transmission loss as an optical fiber coating material) The composition ~ obtained above was coated with a thickness of 50 μm as a primer layer on the surface of a 125 μm diameter quartz fiber doped with Ge ₂ O−P ₂ O ₅ . After that, apply the composition obtained above on the outside.
was coated as a buffer layer with a thickness of 87.5μm,
Next, nylon was applied to this to a thickness of 250 μm, and the optical fiber thus obtained was
When heat-treated at ℃ for 4 hours and examining the increase in transmission loss, the results shown in Table 1 were obtained. 【table】

Claims (1)

[Claims] 1 1) An organopolysiloxane containing at least two vinyl groups [≡Si (CH=CH ₂ ) groups] bonded to silicon atoms in one molecule, 2) Silicon in one molecule A first having at least two hydrogen atoms (≡SiH bonds) bonded to the atom
The molar ratio of the ≡Si(CH=CH ₂ ) group to the ≡SiH bond in the component is ≡Si(CH=CH ₂ )/≡SiH≧1, and the amount of this ≡SiH bond is the difference between the first component and the second component. 3) an organohydrodiene polysiloxane in an amount that provides 0.05 mol or less per 100 g of the total amount of components; 3) a platinum-based addition reaction catalyst;