Catalyst – solid sorbent – or support therefor: product or process – Catalyst or precursor therefor – Organic compound containing
Reexamination Certificate
1999-08-30
2001-06-26
Wood, Elizabeth D. (Department: 1755)
Catalyst, solid sorbent, or support therefor: product or process
Catalyst or precursor therefor
Organic compound containing
C502S150000, C502S162000, C502S159000, C502S172000
Reexamination Certificate
active
06251818
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an accelerator which is used to accelerate the polymerization of cyanoacrylates. More specifically, the invention relates to an accelerator for cyanoacrylate adhesives which are accepted currently and widely in various industrial fields. That is, the accelerator of the invention is suitably used as a pretreatment agent for adhering various adherends by using a cyanoacrylate adhesive more quickly or as an efficient post-treatment agent in the gap-filling adhesion or the mounting adhesion.
2. Description of the Related Art
Since a cyanoacrylate adhesive usually consists of one component, is curable at an ambient temperature, and can bond many kinds of material, it is widely used. However, it is not satisfactory because a gap-filling property, consequently, porous materials such as wood are not well bonded therewith, and mounting adhesion is impossible, and blooming is occurred around an adhered portion of an the work piece due to overflowing of the cyanoacrylate.
In order to solve such problems, others have attempted to improve the rate of polymerization of a cyanoacrylate. Therefore, variety of accelerators have been proposed. For example, JP-B-47-8718 discloses a method in which a surface of an adherend is treated with an accelerator solution containing dimethylaniline or/and tris[1-(2-methyl)aziridinyl]phosphine oxide. JP-B-49-12094 discloses a same method and an accelerator solution containing the specific amine, amide or imide. JP-B-51-25441 discloses vinyl ethers or vinylthioethers as accelerators. JP-B-54-19416 discloses N,N-dimethyl-m-toluidine. JP-B-62-12279 discloses a specific surfactant. JP-B-60-24826 discloses methylolurea and melamine, partially alkoxidized or derivatives thereof.
Among these accelerators, amines are especially effective. However, the amines have brought an older problem Accordingly, some method of controlling occurrence of the amine odor or masking the same has been proposed. For example, JP-B-62-29471 discloses a composition composed of N,N-di-lower alkyl toluidine, saccharin and ascorbic acid or isoascorbic acid. JP-A-59-66471 discloses a mixture of an amine compound, a deodorant and a solvent, respectively. Further, other methods attempt to solve the problem by using amines having high-boiling points. For example, JP-A-6-57218 discloses amines in which at least one hydrocarbon group indicated by R of R
3
N is a long-chain hydrocarbon group having from 8 to 24 carbon atoms and JP-A-5-247412 discloses a nitrogen-containing compound having a dimethylaminoethyloxycarbonyl group or a specific tertiary amine.
In these related techniques, however, the efficiency of acceleration and the control of the odor of the amine were inconsistent. That is, a composition having a satisfactory efficiency in acceleration did not satisfactorily control the odor of the amine.
On the other hand, a composition which satisfactorily controls the odor of the amine was unsatisfactory in the efficiency of accelerations, especially curing efficiency.
SUMMARY OF THE INVENTION
It is an object of the invention to provide, an accelerator for cyanoacrylates almost free from an unpleasant odor and having a high efficiency of acceleration in both case when used in pretreatment post-treatment.
The present inventors have found that the characteristic amine odor of the accelerant is decreased by using an aromatic amine in the host compound if an inclusion compound and results in highly efficient acceleration in both pretreatment and post-treatment.
That is, the invention relates to an accelerator for cyanoacrylates comprising an inclusion compound which has a host compound and an aromatic amine as a guest substance.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The accelerator for cyanoacrylates in the invention is described in detail below.
Aromatic Amine
As the aromatic amine used in the invention, a compound represented by formula (1) is preferable because of a high efficiency of acceleration:
wherein
R
1
and R
2
may be the same or different, and each represents hydrogen or an alkyl group having from 1 to 3 carbon atoms, and R
3
and R
4
may be the same or different, and each represents hydrogen, a methyl group or a hydroxyl group.
Specific examples thereof include aniline, o-toluidine, m-toluidine, p-toluidine, N-methylaniline, N-ethylaniline, N-n-propylaniline, N-isopropylaniline, N-methyl-o-toluidine, N-methyl-m-toluidine, N-methyl-p-toluidine, N-ethyl-o-toluidine, N-ethyl-m-toluidine, N-ethyl-p-toluidine, N,N-dimethylaniline, N,N-diethylaniline, N,N-di-n-propylaniline, N,N-diisopropylaniline, N-methyl-N-ethylaniline, N-methyl-N-n-propylaniline, N-ethyl-N-n-propylaniline, N,N-dimethyl-o-toluidine, N,N-dimethyl-m-toluidine, N,N-dimethyl-p-toluidine, N, N-diethyl-o-toluidine, N, N-diethyl-m-toluidine, N, N-diethyl-p-toluidine and N, N-dimethyl-3-aminophenol.
Among them, the tertiary amines are preferable. N,N-dimethylaniline, N,N-dimethyl-p-toluidine and N,N-dimethyl-3-aminophenol are especially preferable aromatic amines in view of both the odor and the efficiency of acceleration.
Host Compound Constituting the Inclusion Compound of the Invention
As the host compound constituting the inclusion compound of the invention, various compounds including Hemicarcerand as described in
J. Am. Chem. Soc.,
vol. 116, page. 111 (1994) can be used. Cyclodextrins and derivatives thereof are preferable because the inclusion compound of the aromatic amine may easily be formed.
Cyclodextrins are cyclic oligosaccharides, and those having 6, 7 and 8 D-glucopyranoses as structural units are generally called &agr;-, &bgr;- and &ggr;-cyclodextrins. The cavity of cyclodextrins is formed from a CH linkage and an ether linkage, and is in a hydrophobic atmosphere. Thus, cyclodextrins are compounds in which hydrophobic aromatic amines can be included in this cavity.
Cyclodextrins and derivatives thereof are represented by formula (2).
wherein
R
5
, R
6
and R
7
may be the same or different, each represents hydrogen, an alkyl group, an alkenyl group, a cycloalkyl group, an alkylaryl group, an acyl group, a trialkylsilyl group, a urethane group or a monochlorotriazinyl group, and these groups may have a substituent such as a hydroxyl group, an alkoxyl group or a halogen atom and may have an ether linkage or an ester linkage, and n is 6, 7 or 8.
Specific examples of cyclodextrins and derivatives thereof used in the invention include &agr;-cyclodextrin, &bgr;-cyclodextrin, &ggr;-cyclodextrin, methyl-&agr;-cyclodextrin, methyl-&bgr;-cyclodextrin, methyl-&ggr;-cyclodextrin, hydroxypropyl-&bgr;-cyclodextrin, 2,6-di-n-butyl-&bgr;-cyclodextrin, 2,6-di-n-butyl-3-acetyl-&bgr;-cyclodextrin, triacetyl-&bgr;-cyclodextrin, trimethylsilyl-&bgr;-cyclodextrin and monochlorotriazinyl-&bgr;-cyclodextrin.
Among them, derivatives in which hydroxyl groups of cyclodextrins are completely or partially substituted, are preferable to facilitate solubility in water or an organic solvent. Especially preferable derivatives are methyl-&bgr;-cyclodextrin, hydroxypropyl-&bgr;-cyclodextrin and triacetyl-&bgr;-cyclodextrin.
In the production of the inclusion compound of the aromatic amine and the host compound, the ratio of the aromatic amine to the host compound is preferably between 1:0.5 and 1:2, more preferably between approximately 1:1, because the inclusion compound is thereby easily obtained. The inclusion compound of the aromatic amine used in the invention can easily be produced by a general method such as a kneading method, a saturated solution method or a powder mixing method. The inclusion method will specifically be described in Examples later.
The inclusion compound of the aromatic amine used in the invention is usually solid, and it can be used well, as such, as an accelerator for cyanoacrylates. However, the use of this compound which is dissolved in a solvent is preferable because it can uniformly be coated on a substrate. A solvent compatible with the inclusion compound is preferable for use. Solvents having a relatively high
Ohashi Yoshiharu
Sato Mitsuyoshi
Cooper & Dunham LLP
Katz Robert D.
Toagosei Co. Ltd.
Wood Elizabeth D.
LandOfFree
Accelerator for cyanoacrylates does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Accelerator for cyanoacrylates, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Accelerator for cyanoacrylates will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2485084