JP2005089532A - 2-cyanoacrylate-based adhesive composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a 2-cyanoacrylate-based adhesive composition excellent in adhesion/processing of plastic and wooden molds. <P>SOLUTION: The 2-cyanoacrylate-based adhesive composition, particularly excellent in adhesion/processing of plastic and wooden molds, comprises a 2-cyanoacrylate, and a plasticizer selected from a phthalate, an acetyl citric acid triester or a monomer or oligomer having a (meth)acryloyl group, wherein the composition has an acid content of 1.0×10<SP>-6</SP>to 10.0×10<SP>-6</SP>gram equivalent/g. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a 2-cyanoacrylate adhesive composition that is excellent in resin-type and wood-type adhesion and processing.

  2-Cyanoacrylate-based adhesives are widely used as instant adhesives due to their high anionic polymerizability, which are polymerized and cured in a short time by anion species such as adherend surface and moisture in the air to bond various materials. ing.

  However, the cured product of 2-cyanoacrylate is not flexible and exhibits very hard properties. Then, even if it tries to remove the adhesive hardened | cured material which protruded after bonding together, it cannot remove easily from the hardness.

  In the past, attempts have been made to improve the machinability by imparting flexibility to the instantaneous adhesive. Japanese Patent Laid-Open No. 6-329995 discloses a two-part filler using a 2-cyanoacrylate composition as one of the agents and good curability of the cured product, and Japanese Patent Laid-Open No. 11-124522 includes a solidified product. It has been proposed to use a 2-cyanoacrylate composition having a Shore hardness of 40 to 60 for repairing wood.

  On the other hand, Japanese Patent Application Laid-Open No. 61-23630 discloses that an instantaneous adhesive can be applied to bonding when a resin mold or a wooden mold is produced. Resin molds and wooden molds create various types of molds by cutting, adhering, and combining blocks such as resin and synthetic wood. As commercially available blocks, Bantico Co., Ltd. Ren shape and Sanyo Chemical Industries sun module. And when producing resin molds and wooden molds, it has sufficient adhesive strength, and if the adhesive cured product that protrudes after bonding has good machinability, the resulting mold looks very good. Although it is preferred, it is extremely important in the bonding process of resin molds and wooden molds that the curability of the instantaneous adhesive is not too fast and not too slow. This is because the resin mold and the wooden mold are several meters at a large size, so that the curing property of 2-cyanoacrylate itself is too fast and positioning after bonding cannot be performed. Moreover, it is because the adhesive performance as an instantaneous adhesive will not appear when it is too late. However, until now, there has been no 2-cyanoacrylate adhesive suitable for bonding and processing of resin molds and wooden molds, which is compatible with cutting ability and curability of the protruding portion.

JP-A-6-329995 JP-A-11-124522 JP 61-23630 A

  An object of the present invention is to provide a 2-cyanoacrylate-based adhesive composition that is excellent in resin-type and wood-type adhesion and processing.

The inventors of the present invention compounded a plasticizer selected from a specific group in a composition containing 2-cyanoacrylate or 2-cyanoacrylate as a main component, and set the acid content of the compounded composition to 1.0. By prescribing to × 10 ^{−6 to} 10.0 × 10 ⁻⁶ gram equivalent number / g, the adhesive strength after resin mold or wood mold processing is good, and an appropriate cutting workability is given to the protruding portion, It is found that a 2-cyanoacrylate-based adhesive composition that is optimal for bonding and processing of resin molds and wooden molds can be obtained, which has optimal curability that enables positioning and the like when bonding resin molds and wooden molds. The invention has been completed.

  The plasticizer selected from the specific group here is a monomer or oligomer having a phthalate ester, an acetylcitrate triester, and an acryloyl group or a methacryloyl group (hereinafter referred to as “(meth) acryloyl group”). And one or more of these are used. These plasticizers are particularly suitable for the purpose of the present invention because they exhibit particularly sufficient adhesive strength among many plasticizers and further improve the machinability of the cured product of 2-cyanoacrylate adhesive. Was selected and found.

Moreover, the acid content of the composition mainly composed of 2-cyanoacrylate known so far is suppressed to 0.001 × 10 ^{−6 to} 0.5 × 10 ⁻⁶ gram equivalent / g. This is because, since 2-cyanoacrylate is anionic polymerizable, the curing becomes slow when the acid content is high, and the advantages as an instantaneous adhesive are killed. However, in the present invention, it is extremely important that the acid content in the composition is defined as 1.0 × 10 ^{−6 to} 10.0 × 10 ⁻⁶ gram equivalent / g for resin-type / wood-type bonding applications. It was made with the unexpected knowledge.

That is, the present invention is a composition comprising 2-cyanoacrylate and a plasticizer selected from a phthalate ester, an acetylcitrate triester, or a monomer or oligomer having a (meth) acryloyl group, A 2-cyanoacrylate adhesive composition particularly excellent in adhesion and processing of resin molds and wooden molds, characterized in that the content is 1.0 × 10 ^{−6 to} 10.0 × 10 ⁻⁶ gram equivalents / g It is a thing.

  The 2-cyanoacrylate-based adhesive composition of the present invention exhibits extremely optimum machinability and curability for bonding and processing of resin molds and wooden molds, so it is very useful as an instantaneous adhesive for resin molds and wooden molds. It is useful for.

The present invention is described in detail below.
2-Cyanoacrylate is used as the main component of the adhesive composition of the present invention. Specific examples thereof include methyl-2-cyanoacrylate, ethyl-2-cyanoacrylate, propyl-2-cyanoacrylate, and isopropyl. 2-cyanoacrylate, butyl-2-cyanoacrylate, isobutyl-2-cyanoacrylate, amyl-2-cyanoacrylate, hexyl-2-cyanoacrylate, cyclohexyl-2-cyanoacrylate, octyl-2-cyanoacrylate, 2- Ethylhexyl-2-cyanoacrylate, allyl-2-cyanoacrylate, benzyl-2-cyanoacrylate, methoxyethyl-2-cyanoacrylate, ethoxyethyl-2-cyanoacrylate, methoxypropyl-2-cyanoacrylate Over preparative and tetrahydrofurfuryl 2-cyanoacrylate and the like, these 2-cyanoacrylates may be mixed using two or more not only in one kind.

  Among the plasticizers selected from the specific group used in the present invention, specific examples of the phthalate ester include dibutyl phthalate, diethyl phthalate, dimethyl phthalate, diheptyl phthalate, dihexyl phthalate, phthalate Examples include di-n-octyl acid, di-2-ethylhexyl phthalate, diisononyl phthalate, octyl decyl phthalate, diisodecyl phthalate, and butyl pentyl phthalate. These phthalates are not limited to one type, but two types The above can also be mixed and used.

  Specific examples of the acetyl citrate triester include tributyl acetyl citrate.

    Specific examples of the monomer or oligomer having a (meth) acryloyl group include dipentaerythritol triacrylate, dipentaerythritol tetraacrylate, dipentaerythritol pentaacrylate, dipentaerythritol hexaacrylate, trimethylolpropane triacrylate, ethylene glycol diacrylate. Examples include methacrylate, ethylene glycol diacrylate, polyethylene glycol dimethacrylate, polyethylene glycol diacrylate, polybutyl methacrylate oligomer, polymethyl acrylate oligomer, polyethyl acrylate oligomer, urethane acrylate oligomer, and epoxy acrylate oligomer. One monomer or oligomer of Two or more kinds can be mixed and used.

Further, two or more of these phthalic acid esters, acetylcitric acid triesters, and monomers or oligomers having a (meth) acryloyl group may be used in combination.
Of these three types of plasticizers, phthalate esters and monomers or oligomers having a (meth) acryloyl group are preferred because they improve the adhesive strength of the adhesive composition of the present invention. Dimethyl phthalate, phthalic acid Diethyl, dibutyl phthalate, dipentaerythritol pentaacrylate, and dipentaerythritol hexaacrylate are more preferable because they are compatible with 2-cyanoacrylate.
Moreover, 1-50 mass% in the adhesive composition of this invention except the solvent is preferable, and, as for the compounding quantity of a plasticizer, More preferably, it is 5-40 mass%. If it exceeds 50% by mass, the adhesive strength is lowered, and if it is less than 1% by mass, the performance of the plasticizer is not exhibited, which is not preferable.

The 2-cyanoacrylate adhesive composition of the present invention contains the above-mentioned specific plasticizer, and the acid content of the composition is 1.0 × 10 ^{−6 to} 10.0 × 10 ⁻⁶ gram equivalent number. / G.
The acidic component derived from the acid content is an acidic additive, 2-cyanoacrylic acid produced by hydrolysis of 2-cyanoacrylate, and a production stage of cyanoacetate which is one of raw materials used for producing 2-cyanoacrylate In the present invention, the acid content of the composition is adjusted to 1.0 × 10 ^{−6 to} 10.0 × 10 ⁻⁶ gram equivalents / g by adjusting these amounts. To be adjusted.

  In the present invention, the acid content in the 2-cyanoacrylate adhesive composition is measured using the method proposed in JP-A-10-140091.

In order to accurately measure a small amount of acid content, the measurement method avoids analysis by gas chromatography, which may decompose 2-cyanoacrylic acid or the like due to high temperature during measurement, and employs a method based on neutralization titration. Furthermore, in order to accurately grasp only the acid component that hinders the properties of the adhesive, neutralization titration is performed using an indicator having a specific color change range, that is, a pH change range of pH 4.5 to 5.0. It is what you want.
In order to increase the accuracy of neutralization titration, it is preferable to add water to the adhesive composition. Although 0.3 to 5 ml of distilled water is used per 1 g of the composition, it is preferable to use 10 to 200 ml of an organic solvent such as acetone or methyl ethyl ketone in order to suppress polymerization of 2-cyanoacrylate by water. The neutralization titration indicator has a color change range of pH 4.5 to 5.0 when the purpose is to measure the amount of acid in a composition containing 2-cyanoacrylate as a main component as in the present invention. An indicator, specifically, bromophenol blue, 2,4-dinitrophenol, methyl yellow or the like is preferably used, and bromophenol blue is particularly preferably used. As the alkali used for the neutralization titration, a strong base aqueous solution such as NaOH or KOH aqueous solution is used, and the concentration is preferably 1/10 to 1/1000.

  Moreover, it is preferable to use an acidic additive for the preparation of the acid content of the 2-cyanoacrylate adhesive composition of the present invention. This type is not particularly limited, but particularly preferred is sulfur dioxide, sulfonic acid derivative, sulphonic acid, boron trifluoride complex, which is considered to have no significant adverse effect on the properties of 2-cyanoacrylate even when blended. , Fluorinated boronic acid, trialkylborate, carboxylic acid derivatives, compounds having a phenolic hydroxyl group, and the like.

  In addition, the 2-cyanoacrylate adhesive composition of the present invention is blended with a normal 2-cyanoacrylate adhesive, and includes a curing accelerator, an anionic polymerization inhibitor, a radical polymerization inhibitor, a thickener, and improved adhesion. Various additives such as agents, thixotropic agents, colorants, heat stabilizers, softeners, fillers, fragrances, dyes, pigments or solvents may be added.

  Examples of the curing accelerator include additives that can be stably added to 2-cyanoacrylate and accelerate anionic polymerization, such as polyethylene glycol or a derivative thereof, crown ether or a derivative thereof, calixarene or a derivative thereof, or cyclodextrin or a derivative thereof. Can be mentioned.

  An anionic polymerization inhibitor is added for the purpose of preventing anionic polymerization due to moisture or the like in the storage container, and specifically, sulfur dioxide, aromatic sulfonic acid, aliphatic sulfonic acid, sulphonic acid, boron trifluoride complex, fluorine. Examples thereof include boronic acid and trialkylborate.

  The radical polymerization inhibitor is added for the purpose of preventing radical polymerization due to light during storage, and specific examples thereof include hydroquinone or hydroquinone monomethyl ether.

  As thickeners, homopolymers or copolymers of methacrylic acid esters and acrylic acid esters, polystyrene, polyurethane, cellulose esters, ethylene-vinyl acetate copolymers, ethylene-methacrylic acid ester copolymers, ethylene-acrylic acid esters Examples include copolymers, acrylonitrile-acrylic rubber-styrene copolymers, acrylonitrile-butadiene-styrene copolymers, and poly (2-cyanoacrylate).

  Also, in some cases, before applying the adhesive, a primer treatment is applied to the block for the purpose of improving curability and adhesiveness, and after bonding, a sticking agent is used to harden the protruding portion. It is also possible to process.

The present invention blends 2-cyanoacrylate with one or more plasticizers selected from the group of monomers or oligomers having a phthalate ester, an acetylcitrate triester and a (meth) acryloyl group, By regulating the acid content of the blended composition to 1.0 × 10 ^{−6 to} 10.0 × 10 ⁻⁶ gram equivalent number / g, the protruding portion has sufficient adhesive strength after resin mold / wood mold processing In conventional bonding and processing of resin molds and wooden molds, the conventional 2-cyanoacrylate system has appropriate cutting workability and has optimum curability for positioning and the like when bonding resin molds and wooden molds. It has extremely optimized features not found in adhesives.

  EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated in more detail, this invention is not limited to these.

Examples 1-5, Comparative Examples 1-4
As shown in Table 1, various plasticizers were added to ethyl-2-cyanoacrylate in various amounts, and further adjusted with paratoluenesulfonic acid so that the acid content was a constant amount. A 2-cyanoacrylate adhesive composition was prepared. Then, these adhesive compositions were applied to one block and bonded together while being rubbed together. The curability and cutting workability at that time were measured. The block for the base material used was Len Shape 450 (manufactured by polyurethane, bonded area 30 cm × 20 cm) manufactured by Bantico Co., Ltd.

The acid content was measured by the following method.
(1) Weigh accurately 3 g of sample into a 200 ml Erlenmeyer flask.
(2) The sample is diluted with 90 ml of special grade acetone.
(3) After shaking well, add 3 ml of distilled water.
(4) Add a few drops of bromophenol blue solution as an indicator.
(5) A 1/100 N aqueous NaOH solution is dropped dropwise using a microburette, and the point at which the color of the solution changes from yellow to blue is defined as the neutralization end point.

Moreover, the judgment method of cutting workability is as follows.
A spray-type curing agent for instant adhesive was sprayed onto the cured adhesive composition that protruded after the blocks were bonded together, and was completely cured. And the ease of cutting and grinding | polishing at the time of scraping off the said hardened | cured material with the file was determined.

Moreover, the measuring method of adhesive curability is as follows.
After the blocks were bonded together, the time until the adhesive solidified and the blocks stopped moving was measured. Furthermore, according to the result, curability was determined.

  In addition, the adhesive strength was measured by processing the block and following the tensile shear bond strength test method of JIS-K6861 “Testing method for α-cyanoacrylate adhesive”.

Examples 6-8, Comparative Examples 5-6
As shown in Table 2, a certain amount of plasticizer was added to ethyl-2-cyanoacrylate, and then adjusted to have various acid contents with para-toluenesulfonic acid. An adhesive composition was prepared. Then, these adhesives were applied to one block and bonded together by rubbing. The curability, cutting workability, and adhesive strength at that time were measured. In the same manner as in Example 1, Len Shape 450 manufactured by Bantico Co., Ltd. was used for the base block.

As apparent from Tables 1 and 2, the 2-cyanoacrylate is blended with a plasticizer selected from a phthalate ester, an acetylcitrate triester or a monomer or oligomer having a (meth) acryloyl group, and By regulating the acid content of the composition to 1.0 × 10 ^{−6 to} 10.0 × 10 ⁻⁶ gram equivalent number / g, it has good adhesive strength and is moderately cut at the protruding portion after die processing. It has the best curability to allow positioning and the like when bonding resin molds and wooden molds, and it is clearly the conventional 2-cyanoacrylate system for bonding and processing resin molds and wooden molds. It can be seen that it exhibits extremely optimized processability not found in adhesives.

Claims (1)

A composition comprising 2-cyanoacrylate and a plasticizer selected from a phthalate ester, an acetylcitrate triester, a monomer or an oligomer having an acryloyl group or a methacryloyl group, and having an acid content of 1.0. A 2-cyanoacrylate adhesive composition, wherein the composition is × 10 ^{−6 to} 10.0 × 10 ⁻⁶ gram equivalent / g.