JP2000053924A - Composition for impregnation - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prepare a composition for impregnation, having excellent impregnating and curing property to ligneous materials (esp. fiber boards such as hard boards), facilitating reinforcement and repair in field site and capable of improving productivity. SOLUTION: This composition comprises (A) a 2-cyanoacrylate (e.g. methyl 2-cyanoacrylate or the like), (B) a carboxylic acid (e.g. cyanoacetic acid, pyruvic acid, or the like) having 1.2-4.0 pKa and capable of dissolving the 2- cyanoacrylate therein and (C) an anionic polymerization promoter (e.g. a polyalkylene oxide such as diethylene glycol, or the like). It is pref. that the contents of ingredients B and C are ca. 10-2,000 ppm and ca. 0.001-10 wt.%, respectively, based on the quantity of the ingredient A.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an impregnating composition having excellent impregnation hardenability, especially for wood-based materials. In addition, the impregnating composition impregnates and cures the foamed material and exhibits excellent adhesion to an adherend (hereinafter referred to as "impregnated adhesion"). It can be suitably used in the wood-based material processing industry and in the bonding process of foamed materials.

[0002]

2. Description of the Related Art As a kind of wood-based material, for example, a hard board, a particle board, an insulation board, an MDF (Mid Density Fiberboad), etc.
Fiber boards manufactured by cutting wood into chips are widely used as parts for color boxes, storage cases, furniture, and as parts for automobiles and home electric appliances.

[0003] Since fiberboard is made from waste materials such as debris from the demolition of wooden houses and scraps from sawmills, the material strength tends to vary depending on the source of the raw materials. In addition, since the strength of the fiberboard is overwhelmingly weaker than that of veneer or plywood, the edges or curved portions of the board are likely to be broken during processing or molding, and sufficient bonding strength cannot be obtained at the time of joining. There were drawbacks. In order to compensate for this drawback, reinforcement by a method of impregnating and curing a fiberboard with a urea resin, a melamine resin, a phenol resin, or the like has been conventionally performed. However, since these resins must be used after being dissolved in water or an organic solvent, the impregnated portion of the fiberboard may swell or deform. There is a problem that the time until the process is long and productivity is poor.

As a method for solving this problem, 2-cyanoacrylate or a composition containing 2-cyanoacrylate as a main component is applied to a portion to be joined of a wood-based material, particularly a porous wood-based material having a specific gravity of 1.0 or less. A method has been proposed in which the joint is reinforced by impregnation and hardening (see JP-A-57-1100).
No. 6).

However, the 2-cyanoacrylate described in the above-mentioned method for reinforcing a wood-based material or a composition containing the same as a main component has insufficient impregnation-hardening properties on the wood-based material, resulting in poor productivity. It was not suitable for the required work site.

[0006] On the other hand, foamed resin represented by urethane foam is widely used as a cushioning material and the like, and foamed rubber is widely used as a protector for heat insulation piping and the like in automobiles and home electric appliances. Conventionally, rubber-based solvent-based adhesives and hot-melt-type adhesives have often been used when bonding foam materials such as foamed resin and foam rubber to an adherend, or when bonding foam materials to each other. However, cyanoacrylate-based adhesives have come to be used for the purpose of simplifying the bonding operation and shortening the time.

However, even if a cyanoacrylate-based adhesive is used, unlike a normal material, the bonding speed of a foamed material is not sufficient, and is not suitable for use in a work site where productivity is required. Was.

[Problems to be solved by the invention]

It is an object of the present invention to provide excellent impregnating and hardening properties especially for wood-based materials, especially hardboard, particle board, insulation board, and fiberboard such as MDF (Mid Density Fiberboad). Easy to reinforce and repair, improve productivity, and have excellent impregnating adhesion to foam materials,
An object of the present invention is to provide an impregnating composition that can be easily bonded and can improve productivity.

[0009]

SUMMARY OF THE INVENTION 2-Cyanoacrylate, which is a main component of the impregnating composition of the present invention, is a main component of an instant adhesive widely used for industrial, medical and household purposes. It is a monomer having anionic polymerizability. 2-cyanoacrylate is used as an impregnating resin because it hardens at room temperature and has a low viscosity due to its excellent permeability to wood-based materials. In general, it is well known that in order to improve the curability of 2-cyanoacrylate, it is necessary to add an anionic polymerization accelerator described below and to remove impurities, particularly strong acid components, in the monomer as much as possible. However, the present inventors have found that the addition of a specific acid significantly improves impregnation curability and impregnation adhesion only when used for impregnating and curing wood-based materials and for bonding foamed materials. The present invention was completed by finding unexpected facts.

That is, the present invention provides 2-cyanoacrylate,
It is an impregnating composition comprising a 2-cyanoacrylate soluble carboxylic acid having a pKa of 1.2 to 4.0 and an anionic polymerization accelerator.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the composition for impregnation of the present invention (hereinafter referred to as "the composition for impregnation") will be described in detail. (2-Cyanoacrylate) 2-Cyanoacrylate is a main component of the composition for impregnation, and various kinds thereof can be used. Specifically, methyl 2-cyanoacrylate,
Ethyl, chloroethyl, n-propyl, i-propyl,
Allyl, propargyl, n-butyl, i-butyl, n-pentyl, n-hexyl, cyclohexyl, phenyl, tetrahydrofurfuryl, heptyl, 2-ethylhexyl, n-octyl, n-nonyl, oxononyl, n-decyl, n- Esters such as dodecyl, 2-ethoxyethyl, 3-methoxybutyl, 2-ethoxy-2-ethoxyethyl, butoxy-ethoxy-ethyl, 2,2,2-trifluoroethyl, and hexafluoroisopropyl; In addition, two or more kinds can be used as a mixture.

Of these, methyl and ethyl esters are preferred because of their good impregnation curability and impregnation adhesion.

(2-cyanoacrylate soluble carboxylic acid having a pKa of 1.2 to 4.0)
Ka, that is, the logarithm of the reciprocal of the acid dissociation constant is 1.2 to 4.0.
And soluble in 2-cyanoacrylate. Some acids have two or more dissociation stages, but in this case, the value of the first stage of dissociation needs to be within this range.

When the acid dissociation index is less than 1.2, the strength of the acid is too strong, which lowers the anionic polymerizability of 2-cyanoacrylate, impairs the impregnation curability and impregnation adhesiveness of the composition for impregnation. If it exceeds 4.0, the effect of adding this component on impregnation curability and impregnation adhesion is lost. Preferably, it is in the range of 2.0 to 3.6.

Specific examples of this component include N-acetylglycine, anthranilic acid, m-aminobenzoic acid, p-aminobenzoic acid, oxaloacetic acid, formic acid, citric acid, glyoxylic acid, o-chlorobenzoic acid, and m-acetylbenzoic acid. Chlorobenzoic acid,
p-chlorobenzoic acid, chloroacetic acid, 2-chloropropionic acid, 3-chloropropionic acid, cis-cinnamic acid, succinic acid, cyanoacrylic acid, m-cyanobenzoic acid, p-cyanobenzoic acid, cyanoacetic acid, dichloro Acetic acid, m-nitroaniline, o-nitrobenzoic acid, m-nitrobenzoic acid, p
-Nitrobenzoic acid, lactic acid, pyruvic acid, phenoxyacetic acid, fumaric acid, o-fluorobenzoic acid, m-fluorobenzoic acid, fluoroacetic acid, o-bromobenzoic acid, m-bromobenzoic acid, p-bromobenzoic acid, bromo Acetic acid, phthalic acid, isophthalic acid, terephthalic acid, malonic acid, mandelic acid, o-iodobenzoic acid, m-iodobenzoic acid, p-iodobenzoic acid, iodoacetic acid, malic acid and the like.

Of these, cyanoacetic acid and pyruvic acid are preferred because of their good impregnation curability and impregnation adhesion.

The compounding amount of this component is from 10 to 2000 ppm, preferably from 50 to 2000 ppm, based on 2-cyanoacrylate.
1000 ppm. If it is less than 10 ppm, it is difficult to obtain sufficient impregnating curability and sufficient impregnating adhesion to the foamed material, and if it exceeds 2000 ppm, the acid content of the impregnating system composition becomes too high and anionic polymerizability decreases. In addition, the impregnation curability and the impregnation adhesion may be deteriorated.

(Anionic polymerization accelerator) Examples of the anionic polymerization accelerator used in the present invention include polyalkylene oxides, derivatives of polyalkylene oxides, crown ethers, silacrown compounds, and calixarene. The first one can include a polyalkylene oxide or a derivative thereof,
These are Japanese Patent Publication No. 60-37836 and Japanese Patent Publication No. 60-265.
13, JP-B No. 43790, JP-A-63-12808
8 and JP-A-3-167279. Specific examples include the following.

Polyalkylene oxide Diethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycol, polypropylene glycol, poly-1,3-propylene glycol, polytrimethylene oxide, polytetramethylene oxide, polyepichlorohydrin, poly3,3-bis ( Chloromethyl) butylene oxide, polytetramethylene ether glycol, poly 1,3-dioxolane,
Poly-2,2-bis (chloromethyl) propylene oxide, ethylene oxide-propylene oxide block polymer, polyglycerin such as diglycerin, triglycerin and tetraglycerin, formaldehyde condensate, acetaldehyde condensate and trioxane polymer. Further, various polyalkylene oxides which are commercially available as polyether type urethane curing polyols can also be used as the curing accelerator of the present invention.

Polyalkylene Oxide Derivatives As typical polyalkylene oxide derivatives, esters of the above-mentioned polyalkylene oxide and acid (-
1) and ethers (-2) of the polyalkylene oxide and the hydroxy group-containing compound, and the like are preferably used. Further, Japanese Patent Application Laid-Open No.
Compounds disclosed in No. 86, for example, polyalkylene oxide derivatives such as reaction products of isocyanatoethyl methacrylate and polyethylene glycol are also suitably used as the curing accelerator of the present invention. Furthermore, the present invention is not limited thereto, provided that a compound having a polyalkylene oxide structure in the molecule, such as a compound having various substituents at a molecular terminal or a compound having another bond inside a polyalkylene oxide, is used in the present invention. Can be used as a curing accelerator.

-1 Polyalkylene oxide derivative (ester) Acids that can constitute the above ester include acetic acid, propionic acid, butyric acid, isobutyric acid, pivalic acid, pentanoic acid, n-hexanoic acid, and 2-methylpentanoic acid. , N-octanoic acid, n-decanoic acid, lauric acid, palmitic acid, stearic acid, oleic acid, cyclohexylcarboxylic acid, cyclopentylcarboxylic acid,
Cyclopropylcarboxylic acid, acrylic acid, methacrylic acid, maleic acid, itaconic acid, naphthenic acid, benzoic acid,
β-naphthylcarboxylic acid, p-toluenecarboxylic acid, furancarboxylic acid, p-chlorobenzoic acid, monochloroacetic acid, cyanoacetic acid, glycolic acid, lactic acid, phenyloxypropionic acid, succinic acid, glutaric acid, adipic acid, sebacic acid, Examples thereof include butanetetracarboxylic acid, aconitic acid, propane-1,2,3-tricarboxylic acid, citric acid, orthophthalic acid, isophthalic acid, trimellitic acid, and pyromellitic acid.

The following are specific examples of the ester. [1] polyethylene glycol monoalkyl ester,
Polyethylene glycol dialkyl ester and polypropylene glycol dialkyl ester and the like (esters include, for example, acetate, trifluoroacetate,
Laurate, stearate, oleate or methacrylate). [2] Bisphenol A, hydrogenated bisphenol A, trimethylolpropane, glycerin, adipic acid, trimellitic acid, isocyanate compounds, polyalkylene oxide adducts of phosphoric acid or silicic acid (alkylene, for example, ethylene or propylene). [3] polyoxyethylene sorbitan ester, tetraoleic acid-polyoxyethylene sorbite, (polyoxyalkylene) polysilalate, (polyoxyalkylene) polyphosphate, etc.
For example, ethylene or propylene.

-2 Polyalkylene oxide derivative (ether) Examples of the hydroxy group-containing compound that can constitute the above ether include methanol, ethanol, propanol, isobutanol, hexanol, cyclohexanol, 2-ethyloctanol, decanol, lauryl alcohol,
Cetyl alcohol, stearyl alcohol, oleyl alcohol, phenol, α-naphthol, β-naphthol, cresol, t-butylphenol, octylphenol, nonylphenol, p-chlorophenol, resole, bisphenol A, 2-chloroethanol, ethylene cyanohydrin, tri Examples thereof include fluoroethanol, benzyl alcohol, 1,4-butanediol, 1,6-hexanediol, glycerin, sorbitol, hydrogenated bisphenol A, and trimethylolpropane.

Specific examples of the ether include the following. [1] diethylene glycol monoalkyl ether, diethylene glycol dialkyl ether, dipropylene glycol monoalkyl ether, dipropylene glycol dialkyl ether, and the like (alkyl is, for example, methyl, ethyl, propyl, butyl, etc.) [2] polyethylene glycol monoalkyl ether and polyethylene Glycol dialkyl ethers and the like (alkyl is, for example, methyl, ethyl, propyl, butyl, lauryl, cesyl, stearyl or oleyl and the like); polypropylene glycol monoalkyl ether and polypropylene glycol dialkyl ether and the like (alkyl is, for example, methyl, ethyl, propyl , Butyl, lauryl, cecil, stearyl, oleyl or perfluoroalkyl etc). [3] Polyethylene glycol monoaryl ether, polyethylene glycol diaryl ether and the like (aryl is, for example, octylphenyl or nonylphenyl).

The molecular weight of these polyalkylene oxides and derivatives thereof is preferably in the range of 100 to 10,000. If the molecular weight is less than 100, the effect of promoting the curing is small, and if the molecular weight exceeds 10,000, it is difficult to dissolve in 2-cyanoacrylate and the effect of promoting the curing may be reduced.

Crown ether Examples of the anionic polymerization accelerator of the present invention include crown ethers and derivatives thereof, which have already been disclosed in Japanese Patent Publication No. 55-2238 and Japanese Patent Application Laid-Open No. 3-167279. Specific examples include the following.

15-crown-5, 18-crown-
6, dibenzo-18-crown-6, benzo-15-crown-5, dibenzo-24-crown-8, dibenzo-30-crown-10, tribenzo-18-crown-6, asym-dibenzo-22-crown- 6, dibenzo-14-crown-4, dicyclohexyl-18-crown-6, dicyclohexyl-24-crown-8,
Cyclohexyl-12-crown-4,1,2-decalyl-15-crown-5,1,2-naphth-15-crown-5,3,4,5-naphthyl-16-crown-
5,1,2-methylbenzo-18-crown-6,1,
2-methylbenzo-5,6-methylbenzo-18-crown-6,1,2-tert-butyl-18-crown-
6,1,2-vinylbenzo-15-crown-5,1,
2-vinylbenzo-18-crown-6,1,2-tert
-Butylcyclohexyl-18-crown-6 and 1,2-benzo-1,4-benzo-5-oxygen-2
0-crown-7 and the like.

Silacrown compounds Silacrowns or derivatives thereof are also used as anionic polymerization accelerators, and they are disclosed in JP-B-62-31034.
And JP-A-60-168775. Specific examples include the following.

Dimethylsila-11-crown-4, dimethylsila-14-crown-5 and dimethylsila-1
7-crown-6 and the like.

Calixarene Further, calixarene derivatives are also used as anionic polymerization accelerators, which have already been disclosed in JP-A-60-179482, JP-A-62-235379, JP-A-63-88152 and JP-A-6-92895. It is publicized. Specific examples thereof include the following compounds.

5,11,17,23,29.35-hexa-tert-butyl
-37,38,39,40,41,42 -Hexahydroxycalix [6] arene, 37,38,39,40,41,42 -Hexahydroxyoxycalix [6] arene, 37,38,39,40 , 41,42-Hexa- (2-oxo-2-ethoxy) -ethoxycalix [6] arene and 25,26,27,28-tetra- (2-oxo-2-ethoxy) -ethoxycalix [4] arene etc.

The compounding amount of the polymerization accelerator is 0.001 to 10% by weight, preferably 0.01 to 1% by weight, based on 2-cyanoacrylate. If the amount is less than 0.001% by weight, it is difficult to obtain sufficient impregnating curability or sufficient impregnating adhesion to a foamed material. If the amount exceeds 10% by weight, the impregnating curability and impregnating adhesiveness are not so large, and storage stability is high. The properties may be significantly reduced.

The impregnating composition of the present invention may contain, in addition to the above essential components, stabilizers, fragrances, dyes, pigments or solvents conventionally used in addition to the cyanoacrylate adhesive composition. Can be.

Examples of the stabilizer include anionic polymerization inhibitors such as sulfur dioxide, aromatic sulfonic acid, aliphatic sulfonic acid and boron trifluoride complex, and radical polymerization inhibitors such as hydroquinone, hydroquinone monomethyl ether, catechol and pyrogallol. No. Of these, anionic polymerization inhibitors affect impregnation curability and impregnation adhesion, and therefore, aliphatic sulfonic acids such as methanesulfonic acid having an appropriate acid strength are preferable.

The impregnating composition is used after impregnating and hardening a wood-based material, in particular, a whole or a part of a fiberboard.
Specifically, the reinforcement of the edges and corners of the wooden material, the repair of the defective portion by impregnating and hardening the impregnating composition after filling the defective portion of the wooden material with wood chips, and the wooden material Applications such as reinforcement when fixing metal fittings.

The impregnating composition can be used for bonding a foamed resin such as urethane foam or a foamed material such as foamed rubber to another adherend or for bonding foamed materials together. That is, after the foaming material is applied and impregnated with the composition for impregnation, the foamed material is bonded to an adherend and adhered to each other. in this case,
An excellent bonding speed is exhibited as compared with the case where a normal cyanoacrylate-based adhesive is used. The composition for impregnation,
Specifically, there is an application in which, for example, a defective bonding portion generated when the foam material and the skin material are bonded by using another adhesive is quickly repaired.

[0037]

The composition for impregnation of the present invention can easily control the permeability to the wood-based material and the polymerization rate of the permeated resin by adjusting the types and amounts of the three components constituting the composition. It also makes it possible to control the permeability and the bonding speed. However, this impregnating composition has a main component that is the same as a normal cyanoacrylate-based adhesive but is completely different in the method of use, and cannot be explained by a mechanism for accelerating the curing rate of the conventional cyanoacrylate-based adhesive. Things.

However, the excellent impregnation adhesion to the foamed material is presumed as follows. That is, since the present impregnating composition rapidly penetrates into the foam material and hardens, the present impregnating composition exists in a thin film on the surface, and this exhibits a high adhesive speed to the adherend. become. On the other hand, the ordinary cyanoacrylate adhesive does not readily permeate into the foamed material, and remains as a thick film on the surface, so that the adhesion speed to the adherend decreases.

[0039]

The present invention will be described in more detail with reference to examples and comparative examples, but the present invention is not limited to these examples.

Examples 1 to 18 Impregnating compositions having the compositions shown in Table 1 were prepared and subjected to an impregnation hardening test. The results are shown in Table 1. In Table 1, PEG1000 represents polyethylene glycol having a molecular weight of about 1,000, PEG derivative 1 represents methoxypolyethylene glycol methacrylate having a molecular weight of about 1,000, PEG derivative 2 represents polyethylene glycol dimethacrylate having a molecular weight of about 1,000, and MS represents methanesulfonic acid. .

[0041]

[Table 1]

The method of the impregnation hardening test is as follows. The molded particle board is ground with a medium file to make wood powder, and stored in a 23 ° C. × 60% RH environment for 24 hours. Add about 0.1 g of this wood flour, and about 0.1 g of the impregnating composition
, And the time until smoke is measured. Smoke indicates that the impregnating composition has permeated into the wood-based material and has rapidly polymerized, and the time required for this is an indicator of the impregnation curability of the impregnating composition.

Comparative Examples 1 to 14 A 2-cyanoacrylate composition having the composition shown in Table 2 was prepared and subjected to an evaluation test. The evaluation results are shown in Table 2.
PEG 1000 in Table 2 has a molecular weight of about 100
Polyethylene glycol 0, PEG derivative 1 represents methoxypolyethylene glycol methacrylate having a molecular weight of about 1,000, PEG derivative 2 represents polyethylene glycol dimethacrylate having a molecular weight of about 1,000, and MS represents methanesulfonic acid.

[0044]

[Table 2]

As shown in Tables 1 and 2, impregnation curability is different between anionic polymerization inhibitors of methanesulfonic acid and sulfur dioxide because of different acid strengths.
The impregnating curability is dramatically improved by the addition of a carboxylic acid having a of 1.2 to 4.0.

Examples 19 to 23, Comparative Examples 15 to 17 Impregnation compositions and 2-cyanoacrylate compositions having the compositions shown in Table 3 were prepared, and impregnation adhesion tests were conducted. The results are shown in Table 3. Was. Note that PEG1000 in Table 3 was used.
Is polyethylene glycol having a molecular weight of about 1000, PE
G derivative 2 shows polyethylene glycol dimethacrylate having a molecular weight of about 1,000. The method of the impregnation adhesion test is as follows. A 25 mm × 50 mm urethane foam and a soft PVC as an adherend are prepared. On the urethane foam side, the composition for impregnation or Comparative Example 2-
Two drops of the cyanoacrylate composition are applied and pressed by hand for a predetermined time. When the urethane foam is fixed and the soft PVC is peeled off by hand, the time (set time) required for the urethane foam to break the material is measured.

[0047]

[Table 3]

Observation of the cross section of the fractured portion of the urethane foam revealed that the impregnating composition was impregnated into the urethane foam and was cured. As shown in Table 3, it can be seen that the addition of a carboxylic acid having a pKa of 1.2 to 4.0 significantly improves the impregnation adhesion.

[0049]

Industrial Applicability The impregnating composition of the present invention is particularly useful for wood-based materials, especially hardboard, particleboard, insulation board, MDF (Mid Density Fiberboad).
)) To show excellent impregnation hardenability for fiberboard
Reinforcement and repair can be easily performed at the time of molding, processing or joining of wood-based materials, and work efficiency is dramatically improved. At the time of laminating to the adherend and bonding both, a superior bonding speed is exhibited as compared with the case of using a normal cyanoacrylate-based adhesive, and the working efficiency is dramatically improved.

Claims (1)

[Claims] 1. 2-cyanoacrylate having a pKa of 1.
An impregnating composition comprising 2-4.0 cyanoacrylate soluble carboxylic acid and an anionic polymerization accelerator.