Bonding method employing film adhesives
First Claim
1. A method for bonding together two surfaces selected from the group consisting of metals, ceramics, and wood, which comprises(i) applying to a carrier or strippable backing sheet, in the absence of a substance which gives rise to a substantial degree of photoinduced polymerisation through consumption of epoxide groups, a layer of (liquid) composition (consisting of)an epoxide resin containing at least one group of the formula ##STR24## directly attached to an atom of oxygen, nitrogen or sulfur, where either R and R2 each represent a hydrogen atom in which case R1 denotes a hydrogen atom or a methyl group, or R and R2 together represent --CH2 CH2 --, in which case R1 denotes a hydrogen atom,a photopolymerisable compound which is an acrylic ester containing at least one group of the formula
where R3 is a hydrogen, chlorine or bromine atom, or a C1 -C4 alkyl group,and a heat-activated curing agent for epoxide resins selected from the group consisting of polycarboxylic acid anhydride, dicyandiamide, an imidazole, a latent boron difluoride chelate, an aromatic polyamine and a complex of an amine with boron trifluoride or with boron trichloride,(ii) exposing said layer to actinic radiation until the composition solidifies to form an essentially solid, continuous, self-supporting adhesive film due to photopolymerisation of the said photopolymerisable compound while the epoxide resin remains substantially in the thermosettable state,(iii) removing the said solid film from the carrier or strippable backing sheet,(iv) sandwiching the said solid film between, and in contact with, the two surfaces, the said solid film, and(v) heating the assembly to cure the epoxide resin.
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Accused Products
Abstract
A process for bonding surfaces together comprises
(i) exposing to actinic radiation a layer of a liquid composition containing an epoxide resin, photopolymerizable compound, and a heat-activated curing agent for epoxide resins until the composition solidifies to form a film adhesive while the epoxide resin remains substantially heat-curable,
(ii) sandwiching the film adhesive between the surfaces to be bonded, and
(iii) then heating the assembly so that the epoxide resin component of the film adhesive is cured.
Surfaces which may be so bonded may be metal, glass, ceramic, or wood.
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Citations
9 Claims
- 1. A method for bonding together two surfaces selected from the group consisting of metals, ceramics, and wood, which comprises
(i) applying to a carrier or strippable backing sheet, in the absence of a substance which gives rise to a substantial degree of photoinduced polymerisation through consumption of epoxide groups, a layer of (liquid) composition (consisting of) an epoxide resin containing at least one group of the formula ##STR24## directly attached to an atom of oxygen, nitrogen or sulfur, where either R and R2 each represent a hydrogen atom in which case R1 denotes a hydrogen atom or a methyl group, or R and R2 together represent --CH2 CH2 --, in which case R1 denotes a hydrogen atom, a photopolymerisable compound which is an acrylic ester containing at least one group of the formula - space="preserve" listing-type="equation">CH.sub.2 =C(R.sup.3)COO--
where R3 is a hydrogen, chlorine or bromine atom, or a C1 -C4 alkyl group, and a heat-activated curing agent for epoxide resins selected from the group consisting of polycarboxylic acid anhydride, dicyandiamide, an imidazole, a latent boron difluoride chelate, an aromatic polyamine and a complex of an amine with boron trifluoride or with boron trichloride, (ii) exposing said layer to actinic radiation until the composition solidifies to form an essentially solid, continuous, self-supporting adhesive film due to photopolymerisation of the said photopolymerisable compound while the epoxide resin remains substantially in the thermosettable state, (iii) removing the said solid film from the carrier or strippable backing sheet, (iv) sandwiching the said solid film between, and in contact with, the two surfaces, the said solid film, and (v) heating the assembly to cure the epoxide resin. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
- 7. The method of claim 1, in which the photopolymerisable compound does not contain a 1,2-epoxide group.
- 8. The method of claim 1, in which the said liquid composition which is to be converted into an essentially solid continuous film also contains a dual-functional substance having in the same molecule at least one 1,2-epoxide group and at least one dissimilar group through which the substance is polymerised by means of actinic radiation.
- 9. The method of claim 8, in which the dual-functional substance contains in the same molecule at least one group of formula ##STR26## directly attached to an atom of oxygen, nitrogen, or sulfur, and at least one group of formula ##STR27## directly attached to an atom of oxygen, nitrogen, or sulfur, where L is the monovalent photopolymerisable residue of a substance after removal of a hydrogen atom attached directly to an oxygen, nitrogen, or sulfur atom, and
either R and R2 each represent a hydrogen atom, in which case R1 denotes a hydrogen atom or a methyl group, or R and R2 together represent --CH2 CH2 --, in which case R1 denotes a hydrogen atom.
Specification
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- Resources
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Current AssigneeCiba Specialty Chemicals Corp (BASF SE)
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Original AssigneeCiba-Geigy Corporation (Novartis Ag)
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InventorsGreen, George E.
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Primary Examiner(s)Gallagher, John J.
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Application NumberUS06/153,390Time in Patent Office1,995 DaysField of Search156/272, 156/330, 156/306.9, 156/246, 204/159.11, 204/159.14, 204/159.15, 428/345, 428/416, 428/415, 427/44, 427/208.2, 427/53.1, 427/386, 427/54.1US Class Current156/246CPC Class CodesC09J 163/00 Adhesives based on epoxy re...C09J 5/06 involving heating of the ap...Y10T 428/2809 including irradiated or wav...Y10T 428/31518 Next to glass or quartzY10T 428/31522 Next to metal
