JPS59227914A - Curable liquid resin composition and optical fiber coating material based thereon - Google Patents

Abstract

PURPOSE:The titled composition to which various curing means are applicable and which is useful as, for example, an optical fiber coating material very excellent in flexibility and low-temperature properties, containing a liquid diene polymer having an unsaturated bond content within a specified range. CONSTITUTION:A curable liquid resin composition comprising (A) a liquid diene polymer having 1-2 (not inclusive) polymerizable unsaturated groups per molecule (e.g., a reaction product between a hydroxyl group-containing liquid polybutadiene and isocyanatoethyl methacrylate) and (B) a polymerization initiator (e.g., benzoin as a photopolymerization initiator or benzoyl peroxide as a thermal polymerization initiator). This composition is extremely excellent in curability and excellent in workability and compatibility with reactive compounds. The composition can form a cured product which is excellent in electrical properties, water resistance, chemical resistance, flexibility, etc., and shows excellent adhesion to an adherend, so that the composition can be used as an optical fiber coating material, coating agent, paint, adhesive, ink, impreganating material, electrical insulation material, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a curable liquid resin composition and its uses.
Specifically, the present invention relates to a curable liquid resin composition that can be used with seven types of curing means, has excellent flexibility, and has good low-temperature properties, and an optical fiber coating material containing the composition as a main component.

Generally, optical fibers, especially optical glass fibers, are brittle, easily damaged, and have poor flexibility, so they have the disadvantage of being easily damaged by even a slight external force. For this reason, it has been conventional practice to coat the surface of glass with a resin immediately after it is manufactured into fibers.

Epoxy resins and urethane resins are used as these coating resins, but they take a long time to cure, have low productivity, and do not have sufficient adhesion to glass fibers due to poor curing. The flexibility of the N-covered resin film is poor.
The disadvantage was that the transmission characteristics deteriorated, making it unreliable over the long term.

Therefore, in recent years, silicone resins with fewer of these drawbacks are being used most often.) However, this silicone resin has drawbacks such as being extremely expensive and slow production due to its thermosetting properties. .

Furthermore, recently, acrylates such as epoxy acrylate and urethane acrylate have been proposed as coating materials for optical fibers, but these materials have relatively high elastic modulus and glass transition temperature. Optical fibers coated with these materials have the disadvantage of increased transmission loss at low temperatures.

The present inventors have conducted extensive research to develop a resin that does not have the above-mentioned drawbacks, can be applied with various curing methods, has excellent flexibility, and has excellent low-temperature properties as a coating material for optical fibers. . As a result, it has been found that a composition containing a liquid diene polymer having a content of unsaturated groups within a certain range, which is completely different from conventional compositions, can be used extremely effectively as a coating material for optical fibers. Furthermore, we have found that this composition can be effectively used as adhesives, paints, coating agents, etc. in addition to such coating materials, and based on these findings, we have completed the present invention.

That is, the present invention provides a curable liquid resin composition comprising (A) a liquid diene polymer having an average of 1 or more and less than 2 polymerizable unsaturated groups per molecule and (B) a polymerization initiator; The present invention provides an optical fiber coating material containing a curable liquid resin composition as a main component.

The liquid diene polymer that is component (A) of the composition of the present invention has an average of 1 to 2 polymerizable unsaturated groups contained in one molecule.
Must be less than Conventionally, there have been 92 or more polymerizable unsaturated groups per molecule, especially around 2.3, but
When such a coating is applied to an optical fiber and cured, the resulting cured film has a high elastic modulus, which is insufficient for coating an optical fiber. On the other hand, if a liquid diene polymer is used as in the present invention in which the number of polymerizable unsaturated groups contained in one molecule is comparatively small, with an average of 1 or more and less than 2, the cured MW is free from these drawbacks. becomes.

Various types of polymerizable unsaturated groups can be considered in this ζ,
For example, acryloyl group, methacrylateyl group, acrylamide group, methacrylamide group.

Allyl group, vinyl ether group, vinyl thioether group,
Vinylamine groups, among others, acryloyl groups,
A methacryl tetrayl group, an acrylamide group, and a methacrylamide group are preferred.

Various methods can be used to produce the liquid diene polymer having an average of 1 or more and less than 2 polymerizable unsaturated groups per molecule, which is the above-mentioned component (11 active water bulk groups). Reacting acrylic acid or methacrylic acid with the liquid diene-based polymer containing 21 active hydrogen groups, (3) reacting glycidyl acrylate or glycidyl methacrylate with the liquid diene-based polymer containing active hydrogen groups, Reacting a liquid diene polymer or its reaction product with a final isocyanate with hydroxyalkyl acrylate or human tetraxyalkyl methacrylate (
4) reacting a mexyl group-containing liquid diene polymer with acrylic acid or methacrylic acid; (5) an active hydrogen group-containing liquid diene polymer and isocyanate alkyl acrylate, isocyanate alkyl methacrylate;
It can be produced by reacting vinyl isocyanate or propenyl isocyanate.

The active hydrogen group-containing liquid diene polymer used here preferably has an active hydrogen group such as a water group, an amino group, an imino group, a carboxyl group, or a mercapto group at the molecular end, and has a number average molecular weight of 300 to 25,000%. So.

~10,000, especially a diene polymer having 50% or more of 1,4 bonds. These polymers include diene polymers having 4 to 12 carbon atoms, copolymers thereof, and copolymers of these diene monomers and α-olefinic addition polymerizable monomers having 2 to 22 carbon atoms. Specifically, du-butadiene homol remer, isoprene homopolymer, roprene homopolymer, butadiene-styrene copolymer, butadiene-isoprene copolymer, butadiene-acryvnitrile copolymer, butadiene-2-ethylhexyl acrylate copolymer. .

Examples include butadiene-n-octadecyl acrylate cogelimer.

In addition, in these methods (1) to (5), the ratio of the active hydrogen group-containing liquid diene polymer to the unsaturated monomer such as acrylic acid or methacrylic acid is usually active hydrogen group/unsaturated monomer = 17o, which should be appropriately selected in the range of 5 to 1/1.Next, the polymerization initiator, which is component (B) of the composition of the present invention, is classified into photopolymerization initiators and thermal polymerization initiators. These can be used alone or in combination. Furthermore, it may be of a type in which polymerization is initiated by irradiation with an electron beam. Specifically, these polymerization initiators include photopolymerization initiators such as benzoin, benzoin methyl ether, and benzophenone, and thermal polymerization initiators such as benzoyl peroxide, lauryl peroxide, methyl ethyl ketone peroxide, and azobisisobutyl. Examples include nitrile.

The polymerization initiator, which is the component (in the above), is the (A) component in the resin composition.
) It acts effectively as an initiator when polymerizing and curing component (A).The amount used is not particularly limited, but a small amount is sufficient, and it is usually used per 100 parts by weight of component (A). It is 0.5 to 10 parts by weight.

In the present invention, in addition to the above components (A) and (It),
Furthermore, polyfunctional or monofunctional reactive compounds, reactive brepilimers, or reactive diluents can be used as necessary, such as trifunctional oligoester acrylate, pentaerythritol triacrylate, trimethylolpropane triacrylate, hydroxyl Neopentyl glycol diacrylate pivalate 1,6-
Examples include polyfunctional acrylic esters such as hexanediol diacrylate, and monofunctional acrylic esters such as 2-ethylhexyl acrylate, tetrahydrofurfuryl acrylate, and cyclohexyl acrylate. In addition, plasticizers such as phthalate esters and phosphate esters, kaolin, clay 2. Fillers such as silica, lI fuel,
Thixotropic agent.

Various additives such as colorants may be added as desired. The amount of these auxiliary components added is in the range of 0 to 90 parts by weight based on 100 parts by weight of the total amount with component (A).

The resin composition of the present invention consists of the above-mentioned components (A) and (to)) and auxiliary components added as necessary.The resin composition is irradiated with ultraviolet rays, etc., and then heat-treated to form a cured product. Obtainable.

In addition, by coating optical fibers such as glass fibers with the liquid resin composition as described above and curing them, a coating with excellent adhesion to the optical fibers, good low-temperature properties, and excellent flexibility can be obtained.
The strength and flexibility of optical fibers can be increased. Moreover, it is necessary to appropriately select the content of polymerizable unsaturated groups in the liquid diene polymer, which is the component (A), and the blending ratio of the polymerization initiator, which is the component ψ). The elastic modulus of the cured film can be adjusted as desired, and in particular, a cured film with a low elastic modulus can be obtained while maintaining good low-temperature properties. Therefore, the liquid resin composition of the present invention can be effectively used as a main component of a coating material for optical fibers.

As described above, the curable resin composition of the present invention has extremely good curability, and also has excellent workability and compatibility with reactive compounds. Furthermore, the cured product obtained from this resin composition has excellent electrical properties and water resistance.

The curable resin composition of the present invention has excellent chemical resistance, flexibility, etc., and also exhibits excellent adhesion to adherends such as metal, wood, glass, ceramics, etc. If it is cured after being applied, a film or paint film with excellent adhesion and bending resistance can be formed.

Therefore, the curable resin composition of the present invention can be used as a coating material for optical fibers and various other coating materials.

It can be widely and effectively used in paints, adhesives, inks, impregnation materials, electrical insulation materials, etc. Specifically, hardened coatings for optical glass fibers, coatings for optical resin fibers, and breakage prevention coatings for glass bottles, etc.

It is preferably used as an impregnating agent for printed circuit boards and as a coating agent for electrical parts such as capacitor elements.

The invention will now be illustrated in more detail by way of an example.

Reference Example 1 (Production of polybutadiene containing polymerizable unsaturated groups) Hydroxyl group-containing liquid Talybutadiene (number average molecular weight 2800
, viscosity soki/30℃, hydroxyl group content 0.82 me
q15' + - Average number of functional groups per molecule 2.3° Fine structure trans-1,460%, cis-1,420%, vinyl-1,220%) 150 parts by weight, isocyanate ethyl methacrylate (molecular weight 155. 15) 9.6
Mix parts by weight (nao/on = o, s),
Furthermore, 0.12 parts by weight of p-quinone (dibutyltin dilaure) and 0.12 parts by weight of p-quinone as a thermal polymerization inhibitor were added, and the reaction was carried out at 65°C for 4 hours with stirring under an argon atmosphere to obtain a polymerizable polymer. A saturated group-containing polybutadiene (modified polybutadiene (I)) was obtained. The viscosity of this substance is 6
8 voids/30°C, hydroxyl group content Oj7 mθq/1. −
The average number of methacryloyl groups in the molecule was 1.21.

Reference Example 2 In Reference Example 1, monoisocyanate of isophorone diisocyanate-hydroxyethyl acrylate was used instead of isocyanate ethyl methacrylate.
/OH=0.5, but the same reaction as in Reference Example 1 was carried out to obtain a polymerizable unsaturated group-containing polybutadiene (modified butadiene (6)). The viscosity of this product was 280 voids/30°C, 9 hydroxyl group-containing Ma, 36 meq/P r-average number of acrylic groups per molecule was 1.17.

Reference Example 5 In Reference Example 2, the monoisocyanate substitute of isophorone diisocyanate-hydroxyethyl acrylate, D
K) A polymerizable unsaturated group-containing polybutadiene (modified polybutadiene (II '')) was obtained in the same manner as in Reference Example 2 except that a monoisocyanate of lylene diisocyanate-hydroxyethyl acrylate was used.The viscosity of this product was 200 ff/ 30°C1 hydroxyl group jft 0.5
5 meq/f, - average number of acryloyl groups per molecule was 1.15.

Reference Example 4 The same reaction as in Reference Example 1 was carried out except that the amount of isocyanate ethyl methacrylate was changed to 19.2 parts by weight (Moo10H=1.o). B') 7'Tashie> Qv) ) was obtained. The viscosity of this product was 83 peas/filtration at 0°C, the hydroxyl group content was Omeq/f, and the average number of methacryloyl groups in the molecule was 2.30.

Examples 1 to 5 and Comparative Example 1.2 Add the specified amounts (parts by weight) of each compound listed in Table 1,
A 1-1 curable liquid resin composition was obtained by uniformly mixing at 25°C. This composition was poured between two sheets of glass having a thickness of 5 mm with a gap of 1, and was defoamed. Next, using an ultraviolet curing device, irradiation was performed for the time shown in Table 1 under the conditions of intensity 8o/crn and up distance 40crn to obtain a cured product sheet. Table 1 shows the results of measuring the physical properties of the sheet obtained using J-K 5K7113. From these results, the 1% elastic modulus of the sheet obtained from the composition of the present invention is low;
It can be seen that it has excellent flexibility. Furthermore, dynamic viscoelasticity (tan δ) was measured using the cured product sheet. The results are shown in Table 1. This measurement was carried out using a Toyo Baldwin Leo Vipron with a frequency of 110 Hz,
The heating rate was 2°C/min. In view of these, it is clear that the sheets obtained from the compositions of the present invention have excellent low temperature properties.

Test Example 1 'An optical fiber base material synthesized by the VAD method was
The material shown in Example 1 was applied to an optical fiber with an outer diameter of 125 μm that was heated to 0°C and spun at a speed of 20 tn/min, and then cured by irradiating it with ultraviolet rays from a 1.6 kW high-pressure mercury lamp. Ta. The film thickness of the obtained coating 7 IPA is about 4
0 μm, and no change in transmission loss was observed in the coated fiber up to -40°C.

Test Example 2 Approximately 2,000 fibers were synthesized using the vAD method.
External diameter 12 heated to °C and spun at a speed of 40 m7 min.
The resin composition shown in Example 2 was applied to a 5 μm optical fiber and then cured in the same manner as in Test Example 1.

The film thickness of the obtained coated optical fiber 7 was about 40 μm, and no change in transmission loss was observed in the coated optical fiber up to -40°C.

Test Examples 3 to 5 Tests were conducted in the same manner as in Test Example 1, except that the materials shown in Examples 3 to 5 were used as substitutes for the materials shown in Example 1, and similar results were obtained. Ta.

Patent applicant: Nippon Telegraph and Telephone Corporation Idemitsu Kosan Co., Ltd. Representative: Patent Attorney Fujibe Kubota

Claims (1)

[Claims] A curable liquid resin composition comprising (1(A) - a liquid diene polymer having an average of 1 or more and less than 2 polymerizable unsaturated groups per molecule, and (B) a polymerization initiator. (2) The composition according to claim 1, wherein the polymerizable unsaturated group is an acryloyl group, a methacryloyl group, an acrylamide group, or a methacrylamide group. An optical fiber coating material whose main component is a curable liquid resin composition consisting of a liquid diene polymer having at least 2 or more polymerizable unsaturated groups and 03) a polymerization initiator. (4) The polymerizable unsaturated group is The coating material according to claim 3, which is an acryloyl group, methacryloyl group, acrylamide group, or methacrylamide group. (5) The coating material according to claim 3, wherein the optical fiber is an optical glass fiber.