JPS59122568A - Ultraviolet-curing thixotropic adhesive composition - Google Patents

Abstract

PURPOSE:To provide the titled composition having high thixotropic property and storage stability, by compounding a specific ultraviolet-curing resin composition with a filler consisting of fine powder of hydrophilic silicon dioxide and fine powder of silicon dioxide having hydrophobic property attained by covering the surface with CH3 group. CONSTITUTION:The objective composition is prepared by compounding (A) an ultraviolet-curing resin composition composed of (i) an ultraviolet-curing resin selected from (a) unsaturated urethane resins, (b) epoxyacrylate resins, (c) 1,2- polybutadiene resins having (meth)acryloyl group at the terminal, and (d) organopolysiloxanes having (meth)acryloyl group at the terminal, (ii) an addition- polymerizable monomer having one or more CH2=C group in the molecule, and (iii) a photo-sensitizer with (B) a filler composed of (iv) fine powder of hydrophilic silicon dioxide and (v) fine powder of silicon dioxide imparted with hydrophobic property by covering the surface with CH3 group. The amount of the component (iv) is preferably 50-90wt% based on the sum of the components (iv) and (v).

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a thixotropic ultraviolet curing adhesive composition which is rich in thixotropic properties and has improved storage stability.

Structures of conventional examples and their problems In recent years, as evidenced by the development trend of ultraviolet ray hardening agents, the use of chemical reactions caused by ultraviolet rays, r, and rays has become popular in photosensitive agents for copying, materials for display screens, It is popular in the paint, ink, and IC fields, and its use in consumer equipment's printed wiring boards, conductor circuits, relays, sockets, etc. is attracting particular attention. For this reason, many types of photocurable resins have been developed, and many types of ultraviolet curable adhesive compositions having special physical properties depending on their uses have also been proposed. In particular, in the production of said devices, these compositions have special physical properties, such that they are automatically applied by automatic machines.
That is, it is desired to have thixotropic properties.

Conventionally, adhesive compositions having thixotropic properties have been prepared using inorganic fillers such as magnesium silicate, aluminum silicate, bentonite, hydrophilic silicon dioxide fine powder, asbestos, talc mica powder, etc. Are known.

However, in this type of adhesive composition, the filler and the UV-curable resin composition are not compatible with each other, and a separation phenomenon is often observed between the filler and the UV-curable resin composition during storage.

In general, it is a well-known fact that even with thixotropic materials such as grease, the phenomenon of separation of the filler and resin component occurs. Separation phenomenon has been observed, and storage stability has become a problem.

OBJECTS OF THE INVENTION The object of the present invention is to provide a thixotropic ultraviolet curing adhesive composition which is rich in thixotropy, overcomes all the drawbacks of the above-mentioned known techniques, and has improved storage stability. 0 Structure of the Invention In order to achieve this object, the cychnodrobic ultraviolet curable resin composition of the present invention comprises an unsaturated urethane resin, EBOKI 7
At least one UV-curable resin selected from acrylate resin, 1,2-polybutanene resin having an acryloyl group or methacryloyl group at the end, orcappolysiloxane having an acryloyl group or methacryloyl group at the end, and a molecule. At least one 0H2=
An addition polymerizable monomer having a c group and a photosensitizer constitute an ultraviolet curable resin composition, and this ultraviolet curable resin composition is coated with hydrophilic silicon dioxide fine powder and the surface is covered with CH3 groups. A filler made of a mixture of silicon dioxide fine powder that has been made hydrophobic by hydrophobic process is added.

Examples of the ultraviolet curable resin used in the present invention include 1,2-polybutadiene resin having an acryloyl group or a methacryloyl group at the end and having a molecular weight of 500 to 1oooO;
Organopolysiloxane compounds are preferred. molecular weight is 5
If the molecular weight is less than 00, the mechanical properties of the cured resin will be poor, and if the molecular weight is 10,000 or more, the viscosity of the ultraviolet curable resin composition will become too high, resulting in poor workability and impractical use.

Examples of addition polymerizable monomers include styrene, styrene derivatives such as vinyltoluene, acrylic acid compounds such as acrylic acid and butyl acrylate, methacrylic acid compounds such as methacrylic acid and ethyl methacrylate, 1.6-
Polyfunctional acrylic ester compounds or polyfunctional methacrylic ester compounds having two or more unsaturated groups such as hexanediol diacrylate, ethylene glycol dimethacrylate, trimethylolpropane trimethacrylate, and other compounds such as divinylbenzene and diallyl phthalate. Examples include polyfunctional vinyl monomers.

Examples of photosensitizers include benzoin and its derivatives, benzoin ethers such as benzoin methyl ether, benzyl and its derivatives, aryldiazonium salts, anthraquinone and its derivatives, acetophenone and its derivatives, sulfur compounds such as nphenylcisulfide, Benzophenone and its derivatives are also available.

The present inventors have discovered that the present invention can be achieved by adding fillers such as magnesium silicate, bentonite, hydrophilic silicon dioxide fine powder, asbestos powder, talc, and mica powder to the known ultraviolet curable resin composition. It has been confirmed through various actual experiments that the adhesive composition has the desired Chikuno I lobby juice and is storage stable. In this way, the present invention (d) adds a filler consisting of a mixture of hydrophilic di-silicon oxide fine powder and silicon dioxide fine powder whose surface is covered with CH3 groups to make it hydrophobic. The desired effect can be obtained.

The reason for this is that the hydrophilic silicon dioxide fine powder and the surface of CH3
By mixing the silicon dioxide fine powder that has been made hydrophobic by being covered with groups, the resin component and filler become compatible, and the resin component does not ooze out during storage. In addition, in a mixture of hydrophilic silicon dioxide fine powder and silicon dioxide fine powder whose surface has been made hydrophobic by covering it with CH3 groups, 50 to 90 wt% of silicon dioxide fine powder whose surface has been made hydrophobic by covering it with CH3 groups has been blended. Which is the most effective? If it is less than 50 wt%, the storage stability aimed at by the present invention cannot be sufficiently obtained, and still 9 Qw
If the amount is higher than t%, good thixotropic properties will not be exhibited. Furthermore, generally known polymerization inhibitors, adhesion imparting agents, surface hardening accelerators, etc. may be added to the composition of the present invention.

As described above, the present invention uses a generally known ultraviolet curable adhesive composition, a hydrophilic silicon dioxide fine powder, and a carbon dioxide surface.
By adding a filler consisting of a mixture of fine silicon dioxide powder hydrophobized by covering with H3 groups, the object of the invention can be achieved without impairing the thixotropic properties.

Description of examples Examples of the present invention will be described below.

(Example 1) An ultraviolet curable resin composition prepared by mixing 100g of 2-2bis(4-acryloxyjethoxyphenyl)furopane with 2g of benzoin ethyl ether was coated with hydrophilic silicon dioxide fine powder and a surface coated with CH3 groups. The viscosity and thixotropy were measured for each adhesive composition to which 10 g of a filler made of silicon dioxide fine powder covered and hydrophobized was blended in the proportions shown in Table 1. In addition,
Thixotropy was expressed as thixotropic coefficient. The viscosity was measured using a BH type rotational viscometer NC manufactured by Tokyo Keiki Co., Ltd.
Measurement was performed at 25°C using L70-tar. The thixotropinic coefficient is determined by the ratio of 2 rpm/2 Orpm, and the viscosity is shown at 2 Orpm.

(Example 2) Regarding the composition shown in Example 1, 60 g of each
It was stored at 0°C for 6 months and the state of separation was confirmed. The results are shown in Table 2.

Table 1 Table 2 Effects of the Invention As is clear from the above explanation, in order to provide rich thixotropic properties and storage stability, a known ultraviolet curable adhesive composition is coated with hydrophilic silicon dioxide fine powder and the surface thereof. By adding a filler consisting of silicon dioxide fine powder which has been made hydrophobic by covering it with an OH3 loop, thixotropy, which has not been seen in the past, can be obtained. In addition, the amount of the filler added to the known ultraviolet curable adhesive composition may be adjusted, or the blending ratio of the hydrophilic silicon dioxide fine powder and the silicon dioxide fine powder whose surface has been made hydrophobic by being covered with OH3 groups may be adjusted. Toniyo,
It is possible to freely adjust the viscosity and thixotropy according to the application.

As described above, the thixotropic ultraviolet curable adhesive composition of the present invention not only has excellent thixotropic properties but also has good storage stability, and as automation increases in the future, it will become a labor-saving, quality product. Improvements are of great corporate value.

Claims (2)

[Claims] (1) Selected from unsaturated urethane resins, epoxy acrylate resins, 1,2-polybutadiene resins with acryloyl or methacryloyl groups at the ends, and organopolysiloxanes with acryloyl or methacrylate groups at the ends. At least one type of ultraviolet curable resin, an addition polymerizable monomer having at least one CH2-C group in the molecule, and a photosensitizer constitute an ultraviolet curable resin composition, and the ultraviolet curable A thixotropic ultraviolet curing adhesive composition characterized in that a filler consisting of a mixture of hydrophilic silicon dioxide fine powder and silicon dioxide fine powder whose surface is covered with OH groups to make it hydrophobic is added to a resin composition. thing. (2) In a mixture of hydrophilic silicon dioxide fine powder and silicon dioxide fine powder whose surface has been made hydrophobic by covering it with CH3 groups, 60 to 90 wt% of silicon dioxide fine powder whose surface has been made hydrophobic by covering it with CH3 groups is blended. The thixotropic ultraviolet curable adhesive composition according to claim 1, characterized in that: