JPH01169A - Coating composition for silica-based optical communication fiber - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a coating material composition for a silica-based optical communication fiber.

[Prior Art] A quartz-based optical communication fiber, in which both the core and cladding parts are mainly composed of quartz and contains trace amounts of refractive index modifiers such as germanium and phosphorus, has excellent characteristics such as small diameter, heat resistance, weather resistance, It is widely used as a communication medium for public communications, long-distance communications, etc. due to its flexibility, low loss, and large capacity transmission. Generally, the surface of a quartz-based optical communication fiber is coated with a primary coating for the purpose of maintaining strength, alleviating stress, and preventing microbending due to external forces, and then a final coating is applied. The inner side of this secondary coating is coated with a material having a high refractive index such as urethane or phenyl silicone as a primary coat.

Conventionally, addition reaction-curing silicone compositions have been used for coating materials using this method, in which a lower alkenyl group-containing organopolysiloxane and a silicon-bonded hydrogen atom-containing organopolysiloxane undergo an addition reaction in the presence of a platinum-based catalyst and are cured. was. However, the quartz-based optical communication fiber coated with this curable silicone composition has a drawback in that the optical transmission characteristics are deteriorated. This is Electron,
Lett, 19, 1983゜ or 1983 National Conference of the Institute of Electronics and Communication Engineers, Proceedings - α1126, etc., hydrogen gas generated during curing of an addition reaction-curable silicone composition is a silica-based optical communication fiber. It is thought that the material reacts with germanium contained therein as a refractive index adjusting agent to form hydroxyl groups, which absorb light in the infrared region and reduce light transmission characteristics.

To solve this problem, addition reaction-curing silicone compositions have been proposed that aim to reduce the number of days hydrogen gas is generated.

For example, JP-A No. 60-255649 discloses that the molar ratio of silicon-bonded hydrogen atoms to all aliphatic unsaturated groups is 1.
A silicone composition in which the value is controlled to be close to 0 is disclosed, and JP-A-6'1-52616 discloses a silicone composition containing a platinum-based compound catalyst at a value of 0 or more, which is commonly used. things are disclosed.

[Problems to be Solved by the Invention] However, the former silicone composition has a slow curing speed, and the obtained silicone coating material tends to be insufficiently cured and becomes soft. For this reason, the completed silica-based optical communication fiber becomes easily deformed. Further, the latter silicone composition resulted in a colored silicone coating material, and furthermore, when used, there was a problem that it was difficult to control the curing rate due to the large amount of catalyst, and it was not completely satisfactory.

The present inventors have arrived at the present invention as a result of intensive studies aimed at solving the above-mentioned problems.

An object of the present invention is to provide a coating material composition for a silica-based optical communication fiber that cures quickly and generates almost no hydrogen gas.

[Means for Solving Problems and Their Effects] The above objects are: (A) having at least two lower alkenyl groups in one molecule, and the amount of aryl groups accounting for all organic groups contained in the molecule is 101/ an organopolysiloxane which is less than 31 mol% and has a viscosity at 25° C. within the range of 100 to 20,000 centipoise, (B) R1 H8i○1/2 units (R1 is a monovalent hydrocarbon M), RzaSiO unit (R2 is a hydrogen atom or a monovalent hydrocarbon m>
, R35r○3/2 units (R3 is a hydrogen atom or a monovalent hydrocarbon group) and/or Si02 units, and the proportion of aryl groups in the total organic groups contained in the molecule is less than 100/101 mol% and the average molecular line 1
000 to 30,000 organohydrodiene polysiloxane, the molar ratio of all silicon-bonded hydrogen atoms to all lower alkenyl groups in the composition being 0.75:1.00 to 1.05:1.00. and 0. A quartz-based optical communication film characterized by comprising 0.5 to 500 parts by weight of platinum metal to the total ff of 11 million parts by weight of the platinum-based compound (A) component and component (2). This is achieved by a coating composition for fibers.

To explain this, component (A) is the main component of the composition of the present invention, and is an organopolysiloxane containing at least two lower alkenyl groups as radicals in one molecule. Examples of such lower alkenyl groups include vinyl and furyl groups. Examples of organic groups other than lower alkenyl groups include alkyl groups such as methyl, ethyl and propyl groups; and aryl groups such as phenyl and tolyl groups. In the present invention, the proportion of methyl groups in the organic groups contained in such molecules is preferably 95 mol% or more, more preferably 97 mol% or more. In particular, when it contains an aryl group such as a phenyl group, m of the aryl group in the total blind gilJJ contained in the molecule is 101/3.
It is necessary that it be less than 1 mol%. The molecular structure of this organopolysiloxane may be a linear structure, a resin-like structure with branches, or a mixture thereof, but at least it is a viscous fluid with a viscosity of 100 to 20 at 25°C. A range of .000 centistokes is preferred. Note that this component may contain a trace amount of hydroxyl group or alkoxy group.

Specific examples of this component include dimethylpolysiloxane with dimethylvinylsiloxy groups at both ends, dimethylsiloxane methyl and nylsiloxane copolymer with dimethylvinylsiloxy groups at both ends, and dimethylsiloxane/methyl with dimethylvinylsiloxy groups at both ends. Phenylsiloxane copolymer, each of the above polysiloxanes in which the end capping group is replaced with a methylphenylvinyloxy group, (CH3)
s Si O1/2 unit, (CH3)25io unit,
CHsSi 03/2 units, CH3(CH2=CH)S
iO unit, (CH3)2 (CH2=CH)Si 01
/2 unit, CH3(CeHs)SiO unit, Si 02
Examples include copolymers composed of at least three or more units.

Component (B) is a component that characterizes the present invention.

This acts as a crosslinking agent for component (A), and due to the catalytic action of component 0, silicon-bonded hydrogen atoms in this component (
A) Cures by addition reaction with the lower alkenyl group in the component,
It has the effect of forming a silicone rubber layer with almost no hydrogen gas generation.

R251o unit, R3Si O3/2 and/or S
It must be an organopolysiloxane consisting of i02 units.

Here, R1 is a monovalent group represented by an alkyl group such as a methyl group, an ethyl group, or a propyl group, a cycloalkyl group such as a dichlorohexyl group, or a group in which these hydrogen atoms are partially substituted with a halogen atom. is a hydrocarbon group,
R2 and R3 are monovalent hydrocarbon groups or hydrogen atoms similar to R1. In the above formula, representative examples of the group containing a silicon-bonded hydrogen atom present at the molecular chain end of the novolisiloxane include a dimethylhydrodienesiloxy group and a methylphenylhydrodienesiloxy group. In addition, a silicon-bonded hydrogen atom may be contained in the RjSi O unit, that is, the unit that forms the main chain, or the R3Si 03/2 unit, that is, the unit that forms a branched chain. The amount of atomic particles is 10% by weight or less based on the total amount of silicon-bonded hydrogen atoms contained in the component. In addition, these units contain ant ←≠ such as phenyl group. Further, this component may contain a small amount of hydroxyl group or alkoxy group bonded to a silicon atom.

Specific examples of such component (1) include dimethylpolysiloxane with dimethylhydrodiene siloxy groups blocked at both ends;
Dimethylsiloxane/methylphenylsiloxane copolymer with dimethylhydrogensiloxy groups at both ends, dimethylpolysiloxane with methylphenylhydrodienesiloxy groups at both ends, dimethylsiloxane/methylphenylsiloxane copolymer with methylphenylhydrogensiloxy groups at both ends, and Examples include organohydrodiene polysiloxanes in which these polysiloxanes are branched.

In the present invention, the content of silicon-bonded hydrogen atoms in component (2) is preferably within the range of 0.1 to 0.9% by weight. This is because if the amount is less than 0.1% by weight, curing will be insufficient, whereas if it exceeds 0.9% by weight, the coating material may not have the hardness suitable as a coating material for silica-based optical communication fibers. It is. Such organopolysiloxanes include, for example, R3SiC! ,,R2Si
C12, R8i Easily obtained by subjecting a cohydrolyzate obtained by a cohydrolysis reaction of C13 and water, an organohydrodiene polysiloxane, and a diorganopolysiloxane to a heating equilibration reaction in the presence of an acid catalyst. .

In addition, in the present invention, the average molecular weight of component (1) is 500
~30,000 is required, 10
00-10. A range of oOO is preferred.

This is because if the average molecular weight is less than 500, either the boiling point of the Western component is too low or the low-boiling point substances in component (B) increase, which may volatilize during curing.
,000, the number of silicon-bonded hydrogen atoms present at the end of the molecular chain decreases, resulting in insufficient curing.

(2) The blending ratio of the components is: all the silicon-bonded hydrogen atoms, all the lower alkenyl M, and (r)mo) in the composition of the present invention.
, the ratio is 0.75:1.00~1.05:1.0
It is necessary for the can to be 0.

(The platinum-based compound of component 0 is a catalyst for curing component (A) and component (2) through an addition reaction. Chloroplatinic acid, alcohol-modified chloroplatinic acid,
Examples include a complex of chloroplatinic acid and olefins, and a complex of chloroplatinic acid or its olefins dissolved in a solvent such as a ketone or ether. The base used for component 0 is platinum metal based on the total amount of component (A) and component (2).
Preferably, <t is within the range of 1 to '+ooppm.

In the present invention, in order to adjust the curing speed of the composition of the present invention and more effectively suppress hydrogen gas generation, (A) to 0
In addition to the component (D), at least 1 component per molecule
It is preferable to add compounds having 5 alkenyl groups.

Such component (2) is a compound having at least one alkenyl group in one molecule, and its chemical structure is not particularly limited. Specific examples of this component include the following compounds.

□H0H CH.

CH, -st÷Q -C-CmiOH).

CH.

The base of addition of component (D) is all the alkynyl groups in this component and 0
The ratio of the platinum-based compound in the ingredients is 1.0:1 in terms of weight ratio.
The amount is required to be 0 to 15.0:1.0, preferably 3.0:1.0 to 12.0:1.0.

In addition, when the composition of the present invention contains 0 components, the blending ratio of the above-mentioned (2) component is determined by the number of moles of all silicon-bonded hydrogen atoms in component (1) and the alkenyl group in component (A). The ratio of the alkynyl group to the total number of moles of all aliphatic unsaturated groups in the components (and) is 0.75:1.00 to 1.
．． It is necessary to fall within the range of 0.05:1.00.

The composition of the present invention can contain the above-mentioned (A) to 00 parts or (A
) to (0) can be easily obtained by mixing predetermined amounts of components by a conventionally known method.

Further, as a method for coating a silica-based optical communication fiber with the composition of the present invention, for example, it can be applied to the surface of the silica-based optical communication fiber using a coating die, and then heated and cured to coat the fiber.

In addition, conventionally known additives may be added to the composition of the present invention as necessary.
For example, silicas such as dry process silica and wet process silica, metal oxides, mica, talc, pigments, etc. may be added and blended as long as the purpose of the present invention is not impaired.

[Example] Next, the present invention will be explained with reference to Examples.

In the examples, parts are heavy weight parts, percentages when expressing content are weight percent, vi is a vinyl group, Me is a methyl group, and viscosity is a value at 25°C.

Further, the amount of hydrogen gas generated and the curing rate were measured by the following method.

Method for Measuring the Amount of Hydrogen Gas Generated> The composition of the present invention is heated and cured, and a silicone rubber sheet (1
cmx5cn+xO,2cm) and set it to 200
It was heated under the conditions of ℃/1 hour. Next, the generated hydrogen gas was quantified by gas chromatography. Measured values were converted to values at 1 atm and 25°C and expressed in μt/cm.

Method for measuring curing speed> The composition of the present invention was measured using a curelastometer [Toyo Baudwin ■].
JSR Curelastometer] and was cured at a temperature of 150° C., and changes in the hardness of the cured silicone rubber were monitored. The hardness of the completely cured silicone rubber was defined as 100, and the hardening rate was defined as the heating time required to cure the silicone rubber to 70% of this hardness.

[Example 1] 100 parts of dimethylpolysiloxane, (Me
) 2 H8i O1/2 unit, (Me )zsi O
unit, 15 parts of organohydrodiene polysiloxane (average molecule ε 1500) consisting of 3 parts and 2 units of (Me)lsi0, the molar ratio of which is 40:30:30, CH3! 0.01 part of an organosilicon compound represented by the formula CH35i-4-0-C-C=CH) sHs, an octyl alcohol solution of chloroplatinic acid (platinum content ff 10.5%) 0
．． 5 parts were mixed to obtain a coating material composition for a silica-based optical communication glass fiber. When the curing speed of this product was measured using a curelastometer, it took 7 seconds to cure to 70%. Further, when the amount of hydrogen gas generated was measured for the silicone rubber sheet heat-cured at 200° C. for 3 minutes, the amount was 0.4 μt/f. Next, a single quartz-based optical communication glass fiber with a diameter of 125 μm was immersed in the above-obtained coating material composition, and the fiber was immediately pulled up and held vertically in hot air at 300°C for 2 seconds. A quartz-based optical communication fiber coated with silicone rubber having a film thickness of 40 μm was obtained. This silicone rubber coating layer had no bubbles and was colorless and transparent.

[Example 2] 100 parts of dimethylpolysiloxane with a viscosity of 10,000 centipoise and endblocked with dimethylvinylsiloxy groups at both ends, Vi(
5 parts of methylvinylpolysiloxane with a viscosity of 150 centivoices, consisting of Me)2 S:01/2 units and Si02 units in a molar ratio of 2=1, and H(Me)2si01/
a unit and (Me) 3si 01/22 parts, (Me
) 15 parts of a polysiloxane with an average molecular weight of ff 12000 consisting of 2SiO units and MeSi 03/2 units in a molar ratio of 20:10:45:25, 0.01 part of 3-methyl-1-butyn-3-ol and divinyl A total of 15 complexes of tetramethyldisiloxane and chloroplatinic acid
p1) They were mixed to obtain a coating material composition for a silica-based optical communication fiber.

The molar ratio of silicon-bonded hydrogen atoms to total fat tS unsaturated groups in this composition was 0.9. When the curing speed of this product was measured using a curelastometer, it took 16 seconds to reach 70% curing.

Further, after curing this material under conditions of 200° C. for 3 minutes to prepare a silicone rubber sheet, hydrogen gas generation G was measured, and the curve was 2 μt/9. Next, a single quartz-based optical communication glass fiber with a diameter of 125 μm was immersed in the coating material composition obtained above, and the fiber was immediately pulled up and held vertically in hot air at 300°C for 2 seconds. A quartz-based optical communication glass fiber coated with silicone rubber having a thickness of 60 μm was obtained.

This silicone rubber coating layer had no bubbles and was colorless, transparent, and uniform.

[Example 3] 100 parts of dimethylsiloxane/methylvinylsiloxane copolymerized with dimethylvinylsiloxy groups endblocked at both ends and having a viscosity of 10,000 centipoise (vinyl group content: 0.4%), (
Me) 2Vi Si 01/2 Unit Me 3Si
30:40 organopolysiloxane consisting of O1/2 units and Si02 units and containing vinyl groups (m5%)
:20:10, 7 parts of methylhydrodiene polysiloxane having an average molecular weight of ff12,000 were added and mixed.

This was then added with 0.3-phenyl-1-butyn-3-ol.
01 parts and a complex of divinyltetramethyldisiloxane and chloroplatinic acid were mixed to give a total of 1 opp+a to obtain a coating material composition for a silica-based optical communication fiber.

The ratio of silicon-bonded hydrogen atoms to all aliphatic unsaturated groups in this composition was 0.90. The curing rate of this composition was 18 seconds to 70% cure as measured by a curelastometer. Moreover, the amount of hydrogen gas generated by this composition is 1μ for silicone rubber cured at 200°C for 1 minute! , /9.

Next, a single quartz-based optical communication glass fiber with a diameter of 125μ was immersed in the coating material composition obtained above, immediately pulled up into a vertical shape, and kept in hot air at 300'C for 2 seconds. A quartz-based optical communication glass fiber coated with silicone rubber having a thickness of 6 μm was obtained.

[Comparative Example 11 100 parts of dimethylpolysiloxane with a viscosity of 2500 centipoise and end-blocked with dimedylvinylsiloxy groups at both ends and 0.6 part of methylhydrodiene polysiloxane end-blocked with trimethylsiloxy groups were added and mixed, and then 3-phenyl-1- 0.01 part of butyn-3-ol and a complex of divinyltetramethylpolysiloxane and chloroplatinic acid were mixed in a total amount of 10 ppm to obtain a coating material composition for a silica-based optical communication fiber. Here, the molar ratio of silicon-bonded hydrogen atoms to all aliphatic unsaturated groups was 1.2't'. The curing speed of this composition was measured in the same manner as in Example 3, and it was found that it took 5 seconds to reach 70% curing. Further, when hydrogen gas generation ω from a silicone rubber sheet prepared by curing at 150° C. for 30 minutes was measured, hydrogen gas generation of as much as 700 μf/9 was measured.

[Comparative Example 2] 100 parts of dimethylpolysiloxane with a viscosity of 2,500 centivoise and endblocked with dimethylvinylsiloxy groups at both ends, H(Me
) 2Si O1/2 unit, (Me)3si01/2
2 parts of a resinous organopolysiloxane consisting of Si02 units and a content of hydrogen atoms bonded to silicon atoms of 0.4%, 0.3 parts of 3-methyl-1-butyl-3-ol.
01 parts, an octyl alcohol solution of chloroplatinic acid (platinum content FF 10.5%) was mixed to form a quartz-based optical communication glass film. A coating material composition for carp was obtained. The ratio of silicon-bonded hydrogen atoms to total aliphatic unsaturated groups in this composition was 0.9.

When the curing speed of this composition was measured in the same manner as in Example 1, it took 42 seconds to achieve 70% curing. Also 2
The amount of hydrogen gas generated from the silicone rubber sheet heated and cured under the conditions of 00''C for 13 minutes was 30 μt/9.

Next, a single quartz-based optical communication glass fiber with a diameter of 125 μm was immersed in the coating material composition obtained above in the form of a single wire, and the fiber was immediately pulled up and held vertically in hot air at 300° C. for 2 seconds. A quartz-based optical communication fiber coated with silicone rubber having a film thickness of 40 μm was obtained. However, this silicone rubber coating layer had a sticky surface and was found to be insufficiently cured.

[Comparative Example 3] H(Me) 2si 01 /22 parts, (Me)2S
A silicone resin (containing silicon-bonded hydrogen atoms, ff 10.9%) was synthesized, which was composed of iO units and (Me 2 )Si 03 parts and 2 units in a molar ratio of 3:1:1. This silicone resin had a boiling point of 150° C./3 or less, and the average molecular group (number average molecular weight) in terms of polystyrene analyzed by gel permeation gas chromatography was 500.

Next, 1 part of this silicone resin, 100 parts of dimethylpolysiloxane endblocked with dimethylvinylsiloxy groups at both ends with a viscosity of 2000 centistokes, 3 methyl 1 butyne 3ol o and oi parts, and an octyl alcohol solution of chloroplatinic acid (
A coating material composition for a quartz-based optical communication glass fiber was obtained by mixing 0.5 part of platinum (ω0.5%).

When this composition was cured at 200° C. for 3 minutes, the surface of the cured product was not smooth, and it was found that this composition was not suitable as a coating material for quartz-based optical communication fibers.

[Effects of the Invention] The present invention is a coating material composition for a silica-based optical communication fiber, which is composed of an addition reaction-curable silicone composition using a specific organohydrodiene polysiloxane as a crosslinking agent, which is component (1), so that it cures quickly. In particular, it has the characteristic that the generation of hydrogen gas ω is almost non-existent. Taking advantage of these characteristics, it can be suitably used as a coating material for silica-based optical communication fibers. Furthermore, the silica-based optical communication fiber coated with the silica-based optical communication fiber composition of the present invention has no transmission loss due to hydrogen gas generated from the coating material, and is suitable for public communication and long-distance communication. It can be suitably used as an optical communication fiber.

Claims (1)

[Scope of Claims] (A) has at least two lower alkenyl groups in one molecule, the amount of aryl groups accounting for less than 101/31 mol% of all organic groups contained in the molecule, and Organopolysiloxane with a viscosity within the range of 100 to 20,000 centipoise at 25°C, (B) ▲Mathematical formulas, chemical formulas, tables, etc. ▼1/2 unit (R^1
is a monovalent hydrocarbon group), R^2_2SiO unit (R^2 is a hydrogen atom or a monovalent hydrocarbon group), R^3SiO^3/_2 unit (
R^3 consists of a hydrogen atom or a monovalent hydrocarbon group) and/or a SiO_2 unit, the amount of aryl groups occupying less than 100/101 mol% of the total organic groups contained in the molecule, and the average molecular weight 500 to 30,000 organohydrogenpolysiloxane The molar ratio of all silicon-bonded hydrogen atoms to all lower alkenyl groups in the present composition is from 0.75:1.00
1.05:1.00, and (C) platinum-based compound from 0.5 to 500 parts by weight as platinum metal based on 1 million parts by weight of the total amount of components (A) and (B). A coating material composition for a silica-based optical communication fiber, characterized in that: