JPS6083907A - Coating material for optical glass fiber - Google Patents

Abstract

PURPOSE:To improve the curability by mixing a urethane (meth)acrylate oligomer as a principla component with a (meth)acrylate compound having long- chain aliphatic group as a reactive diluent, vinylpyrrolidone as a cross-linking agent, benzophenone and an aliphatic amine as the components of a curing agent. CONSTITUTION:A (meth)acrylate oligomer having urethane crystals in the molecular skeleton and 2-5 methacryloyl groups in the molecule is used as a principal component. The oligomer is viscous at ordinary temp. and has 200-50,000 average mol.wt. A (meth)acrylate compound having a long-chain aliphatic group such as a long-chain alkyl group in the molecular skeleton is used as a reactive diluent. The compound is liq. at orginary temp. and has 200-5,000mol.wt. The (meth)acrylate oligomer is uniformly mixed with the (meth)acrylate compound, vinylpyrrolidone as a cross-linking agent for said two components, a benzophenone photopolymn. initiator and an aliphatic amine such as dimethylethanolamine as the components of a curing agent to obtain a coating material having 5,300cps viscosity at 25 deg.C.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an ultraviolet or electron beam curing material for coating optical glass fibers for light transmission.

Optical glass fibers (hereinafter referred to as optical fibers) used for optical transmission are brittle, easily damaged, and have poor flexibility, and are easily destroyed by even a slight external force due to such scratches. For this reason, it is extremely difficult to use optical fibers as they are for optical transmission. Therefore, conventional methods have been attempted in which the surface of an optical fiber is coated with a resin before and after spinning from a glass base material, thereby maintaining the initial strength immediately after manufacturing the optical fiber and producing an optical fiber that can withstand long-term use.

Characteristics required of such resin coating materials include good adhesion to optical fibers, excellent flexibility that absorbs and relieves lateral pressure, and is also required for mass production of optical fibers. In order to make this possible, it is desirable that the coating has good curability so that it can be cured quickly after being coated on the surface of the optical fiber.

There are few ultraviolet or electron beam curable materials known as conventional coating materials of this type that satisfy all of the above-mentioned required properties, and those with particularly good flexibility tend to have poor curability. If this is done in a short period of time, there are problems such as a decrease in strength due to insufficient curing, and a sticky feeling that remains, making it impossible to wind the bobbin.

From the above viewpoint, the present invention was discovered as a result of intensive studies aimed at obtaining an ultraviolet or electron beam curing coating material that satisfies the above-mentioned required properties and is particularly curable. Yes 1, the gist of which is a.
) urethane (meth)acrylate oligomer, b) (meth)acrylate compound containing a long chain aliphatic group, C)
A coated paulownia material for an optical fiber is characterized in that it contains vinylpyrrolidone, d) a benzophenone photopolymerization initiator, and C) an aliphatic amine.

In this specification, (meth)acrylate or a compound including this term is a general term for acrylate and methacrylate, and means that it may be either one or both of the two compounds.

In the coating material of this invention, the above-mentioned C is used as the main component.
Good results were obtained in terms of adhesion to the surface of the optical fiber after curing and its flexibility, and by using the components listed in "2" as the reactive diluent,
1] Excellent curability was obtained by using the above C component as a crosslinking component for both components, and components d and e described in 2. Furthermore, it is possible to perform a good resin coating without leaving any sticky feeling.

The urethane (meth)acrylate oligomer as the C component used in this invention has an average molecular weight that has a urethane bond in the molecular skeleton and 2 or more, usually up to 5, acryloyl groups or methacryloyl groups in the molecule. A wide range of (meth)acrylates, which are generally viscous at room temperature and have a molecular weight of about 200 to 50,000, are included. Specific examples thereof include polyether-based urethane (meth)acrylate oligomers, polyester-based urethane (meth)acrylate oligomers, and polybutadiene-based urethane (meth)acrylate oligomers.

The (meth)acrylate compound containing a long-chain aliphatic group as the b component used in this invention includes a long-chain aliphatic group such as a long-chain alkyl group or a long-chain polyoxyalkylene group in the molecular skeleton. The molecular weight of the liquid at room temperature is usually 2.
(Meth)acrylates of the order of 00 to 5,000 are broadly included. Representative examples include compounds represented by the following general formula.

b) CH2=CR1-cooR2 [In the formula, R1 is hydrogen or methyl, K, R, is an alkyl group, and R3 is an alkylene group] The number of carbon atoms in the long chain aliphatic group in the above compound is 7.
or more, preferably 1 o or less, and the upper limit is usually 1
up to 00. In addition, as in the above general formula, when the aliphatic group contains both an alkyl group and a polyoxyalkylene group, the total number of carbon atoms in the aliphatic group may be within the range of several months or two.

As mentioned above, these (meth)acryle-I compounds act as reactive diluents for component C, while also improving the flexibility of the cured product. It is useful for j.

Use of a cono(meth)acrylate compound: 1゛ is the total of the above C component and the C component described below.
The amount is preferably 60% by weight, preferably 30 to 50% by weight. If the amount of acid component (I) used is too large, problems such as poor curability and reduced strength of the cured product will occur.

Vinylpyrrolidone as component C used in this invention is a vinyl monomer represented by the structural formula: When used in combination with components d and C, it has the function of significantly accelerating the curing speed. The amount used is preferably 5 to 40% by weight, preferably 10 to 2% by weight, based on the total amount of components a and b. If the amount of component C used is small, sufficient curing speed cannot be obtained,
On the other hand, if the amount increases, problems such as a decrease in the mechanical strength of the cured product will occur.

Examples of the benzophenone photopolymerization initiator used as component C in the present invention include penzophenone, methyl orthobenzoyl benzoate, and 2,2-jethoxyacetophenone.

Thioxane-based initiators, benzoin ether-based initiators, acetophenone-based initiators, etc. are known as general UV-curable or electron beam-curable photopolymerization initiators.
These initiators do not provide the excellent curability that is the object of this invention. The amount used is the above component a, component b and C.
0.1 to 10 parts by weight per 100 parts by weight of the total amount of ingredients
parts, preferably 1 to 5 parts by weight.

The aliphatic amine as the C component used in this invention effectively acts as a promoter of the C component, and if an aromatic amine or the like is used instead of the aliphatic amine, the li'Jj-forming property will be poor. , the purpose of this invention is achieved.

Specific examples of the above aliphatic amine include dimethylamine,
Monoamines such as dimethylethanolamine, triethanolamine, and triethylamine with a molecular weight of 4° to 300, and tetramethylethylenediamine, pentamethyldiethylenetriamine, and other monoamines with a molecular weight of 40 to 300.
Examples include about 300 polyamines. The amount used is preferably 01 to 10 parts by weight, preferably 1 to 5 parts by weight, based on 100 parts by weight of the total amount of component C, component I) and component C.

The coating material for optical fibers of this invention has the above components a to e as essential components, and if necessary, adhesion imparting agents such as silane coupling agents and various conventionally known additives are blended therewith. The overall viscosity is 1.000 to 10.000 centipoise/25 from the viewpoint of coating workability.
It is desirable that the temperature be adjusted within the range of °C.

When applying this coating material to an optical fiber, the above-mentioned material is coated on the surface of the optical fiber immediately after spinning by an appropriate means so that the thickness after curing is 10 to 200μ, and then irradiated with ultraviolet rays or electron beams. All you have to do is trip over it and let it harden. The resulting hardened layer has flexibility and adhesion to the optical fiber.
When forming a two-layer resin coating with this as an inner layer, coat this layer with polyamide resin, a general thermosetting type, or a UV-free [7 electric P wire curable material]. It can be cured to form a hardened surface with good abrasion resistance.

As described above, the IKI 4A material of the present invention has the characteristics that it can be rapidly cured by ultraviolet rays or electron beams, and that the cured product has excellent adhesion and flexibility to the optical fiber surface. There is. In addition, since the C component among the essential components itself has a high refractive index,
It acts to increase the difference between the refractive index of the entire cured product and the refractive index of the optical fiber, which is one reason for improving the optical transmission characteristics.

EXAMPLES Below, examples of the present invention will be described in more detail. In addition, in the following, fIS means parts by weight.

Example 1 Mol of polyester polyol synthesized from ethylene glycol and adipic acid and tolylene diincyanate 2
A number average molecule i1,9 obtained by reacting the reaction product with 2 moles of 2-hydroxyethyl acrylate
To 50 parts of polyester urethane acrylate oligomer No.
Acrylate having a long chain aliphatic group represented by the general formula; R1-hydrogen in the general formula, R2=nonyl group, R
, = ethylene group, n-25), 10 parts of vinylpyrrolidone, 5 parts of hensifhenone and 3 parts of dimethylethanolamine were uniformly mixed to prepare an optical fiber of the present invention having a viscosity of 5.300 centipoise/25°C. It was used as a covering material.

Example 2 The light of this invention having a viscosity of 2,600 centipoise/25°C was prepared in the same manner as in Example 1 except that the amount of Aloex M113 used was changed to 30 parts and the amount of vinylpyrrolidone used was changed to 20 parts. Obtained a fiber coating.

Comparative Example A comparative optical fiber coating material having a viscosity of 7.450 centivoids/25°C was obtained, except that the amount of Aloex M113 used was changed to 50 parts and vinylpyrrolidone was not used at all.

Example 3 Instead of Aroex M113, 1-1 Mokukayaku Co., Ltd. trade name T'CI 2 OS (an acrylate having a long chain aliphatic group represented by the above-1 formula C; R1 in the general formula C) was used.
The optical fiber liquid NjA material of the present invention having a viscosity of 6,300 centipoise/25° C. was prepared in exactly the same manner as in Example 1 except that 40 parts of -hydrogen, R3-pentamethylene group, n = 2') were used. I got it.

Example 4 Same as Example 1 except that 40 parts of lauryl methacrylate was used instead of Aroninx M113 and 3 parts of dimethylamine was used instead of dimethylethanolamine, and the viscosity was 4,500 centipoise/25. °
A coating material for optical fiber of this invention of C was obtained.

In order to evaluate the performance of the coating materials 1 of the above Examples and Comparative Examples, each material was coated on a glass plate 2 to a thickness of 0.2 wrtr, and then exposed to a 1.80 W/cm high pressure mercury lamp 2.
The curing properties were examined at a predetermined conveyor speed using a light (one cycle) and the properties of the cured product after complete curing.

The results were as shown in the table below.

The curability was evaluated as (x) if the cured product was not cured, (m) if the cured product had some tackiness, and (○) if it was completely cured without any tackiness. Further, the properties of the cured product were measured using a Shore hardness tester type A for hardness, and a tensile test method based on JIS K69]1 for Young's modulus and elongation using a Tambell No. 3 test piece.

(×) A, B, C represent conveyor speed, A is 5
0 nz/min, B is 30 m/min, and C is 10 m/min.

As is clear from the above results, it is clear that according to the present invention, it is possible to provide a coating material for optical fibers that has excellent curability and cured product properties, particularly flexibility.

1 person for patent Nitto Electric Industry Co., Ltd. Mr. Commissioner of the Patent Office 1, patent application for indication of the case 1982-1! 12893 No. 2, Name of the invention Coated publication material for optical glass fiber 3, Vl related to the case of the person making the amendment Patent applicant address Shimohozumi, Ibaraki City, Osaka Prefecture IT Ll No. 1 and 2 Name (396) Nitto Electric ” - Representative of Industry Co., Ltd.
Direction '-, Part 4, Agent postal code 530 7, Contents of amendment A, Specification; 11 Kaoru zl;: 1.Special application for display of incident 1984-4! 12893 No. 2, Name of the invention: Optical glass fiber liquid JY (+A F'-13, Relationship with the person making the amendment) Patent issue: IRJi Person: 1-1-2, Shimohozumi, Ibaraki-shi, Osaka Name: (
396) Nitto Electric Industry Co., Ltd. Representative ``2 So'' 3 Part 4, Agent postal code 530 Voluntary 7, Contents of amendment A, Details @: (11th, page 7, lines 1 to Z 1 ``,2・First of all, I deleted the text "2-Jethoxyacetophenone".

Patent applicant: Nitto Electric Industry Co., Ltd.

Claims (1)

[Claims] flea) Urethane (meth)acrylate oricomer-1
A coating material for an optical glass fiber, comprising b) a (meth)acrylate compound containing a long-chain aliphatic group, C) a vinylpyrrolidone and CD benzophenone photopolymerization initiator, and e) an aliphatic 7'mine.