摘要:
The present invention relates to cure accelerators useful for anaerobic curable compositions, such as adhesives and sealants. The cure accelerators are constructed as urethane/urea/thiourethane (meth)acrylate resins from diols and include a unit embraced within structure A where X is C1-20 alkyl, C2-20 alkenyl, or C7-20 alkaryl, any of which may be interrupted by one or more hereto atoms, and which are functionalized by at least one and preferably at least two groups selected from —OH, —NH2 or —SH and z is 1-3.
摘要:
The present invention relates to a process for producing 2-cyanoacetic acid anhydride, comprising the steps of a) preparing a reaction mixture, containing as reactants 2-cyanoacetic acid, and at least one C 4-20 carboxylic acid anhydride in at least one organic solvent, wherein the molar ratio of 2-cyanoacetic acid to C 4-20 carboxylic acid anhydride in said reaction mixture is greater than 1.5:1, and b) subjecting the reaction mixture to a temperature of 0°C to 100°C to form 2-cyanoacetic acid anhydride. The present invention also relates to process for producing 2-cyanoacetic acid esters, 2-cyanoacetic acid amides and/or 2-cyanoacetic acid thioesters from 2-cyanoacetic acid anhydride.
摘要:
This invention relates to cyanoacrylate-containing compositions that exhibit at least one of improved shock resistance and bond strength, while demonstrating relative surface insensitivity with respect to establishing and maintaining fixture times that are on the order of comparable cyanoacrylate compositions without the added carboxylic acids, The compositions include, in addition to the cyanoacrylate component, certain carboxylic acids.
摘要:
A dispensing nozzle (1) having: (i) an elongate nozzle body (2) having a base portion (3) and a dispensing end (5); (ii) an internal conduit (6) in the nozzle body (2) for delivering product from the base portion (3) to the dispensing end (5); (iii) engaging formations on the nozzle for inter-engaging with co-operating engaging formations (8a, 8b) on a cap (100), to hold said cap (100) in a position over-fitting the nozzle (1); and (iv) an external ramp (9a, 9b) on the nozzle body (2) and against which a co-operating portion (110) on the cap (100) may act, to provide sufficient relative separation force between the cap (100) and the nozzle body (2), to separate the engaging formations (8a, 8b) on the cap and the nozzle (1) from an interengaged position. The cap (1) and nozzle (100) when inter-engaged are easily separated by substantially less than one 360° turn and provide a strong separating force which can overcome fouling or bonding caused by curing of dispensed product.
摘要:
The present invention is directed to a photocurable composition for use as in particular an encapsulant, capable of curing at wavelengths greater than 290 nm. Reaction products of these photocurable compositions are opaque but good CTV is achieved. The composition is initially substantially transparent but becomes opaque on exposure to uv. The composition cures while the colour change takes place. In use, the photocurable composition may be applied, for instance, over the wire bonds that electrically connect a semiconductor device to a substrate to maintain a fixed positional relationship and protect the integrity of the electrical connection from vibrational and shock disturbances, as well as from interference from environmental contaminants.
摘要:
A method of providing a seal, for example in the form of a gasket, between an aluminium substrate and a second substrate, said seal being exposed to fluids at elevated temperatures, particularly in an automotive engine. The method includes the steps of: (a) applying to at least one of the substrates an anaerobic sealant composition comprising: (i) one or more polymerizable (meth)acrylate ester monomers, (ii) an anaerobic cure-inducing component, and (iii) an adhesion promotor comprising one or more phosphorus-containing compounds having general formula (I) wherein R is H, CH3 or C2H5; R is -CH2-, -C2H4-, -C3H6-, or -CH2-CH(CH3)-; R is H, CH3 or C2H5; n is an integer from 1 to 10, and m is an integer from 1 to 3, (b) bringing the substrates into face-to-face contact, and (c) allowing or enabling the composition to cure at substantially ambient temperature. An exemplary adhesion promotor comprises a combination of bis(2-hydroxyethyl methacrylate) acid phosphate and 2-hydroxyethyl methacrylate acid phosphate, optionally with the addition of tris(2-hydroxyethyl methacrylate) acid phosphate.
摘要:
The invention is a nozzle assembly (3, 20) with a re-useable break off cap (20) for dispensing a product from a container (1). On a dispensing end (5) of the nozzle (3) a break-off cap is integrally formed thereon and closes off the dispensing end (5) of the nozzle (3). The break-off cap (20) is removable by breaking a frangible connection (22) between the nozzle (3) and the break-off cap (20). Removing the break-off cap opens the dispensing end (5) of the nozzle (3) thereby allowing product to be dispensed through the nozzle (3). The break-off cap (20) removed from the nozzle (3) can then be re-engaged with the nozzle (3) to close off the dispensing end (5) thereby preventing further product from being dispensed. The cap can be attached to or removed from the nozzle (3) as often as a user requires. The invention also includes packaging which includes a tray (111) or pouch into which the nozzle assembly (3, 20) and container (1) can be inserted. A flexible resealable peel-off cover (110) is provided on each tray (111) to allow a user to resealably open and close the tray (111). The resealable tray (111) can be provided either singly or as a series of trays.
摘要:
An activator composition for the accelerated hardening of cyanoacrylate adhesives, wherein the activator comprises a member selected from the group consisting of: aromatic heterocyclic compounds having at least one N hetero atom in the ring(s) such as pyridines, quinolines and pyrimidines and substituted on the ring(s) with at least one electron - withdrawing group which decreases the base strength of the substituted compound compared to the corresponding unsubstituted compound, mixtures of any of the foregoing with each other, and/or with N,N-dimethyl-p-toluidine, and mixtures of any of the foregoing and/or N,N-dimethyl-p-toluidine with an organic compound containing the structural element, -N=C-S-S-, such as dibenzothiazyl disulfide. 6,6'dithiodinicotinic acid, 2,2'-dipyridyl disulfide, and bis(4-t-butyl-1-isopropyl-2-imidazolyl) disulfide. An activator composition may comprise a solution of one or more activators in a solvent mixture which comprises a volatile hydrocarbon and a cyclic ketone.