GB2132130A

GB2132130A - Method of bond moulding rubber on glass, and products obtained thereby

Info

Publication number: GB2132130A
Application number: GB08327878A
Authority: GB
Inventors: Corrado Tavella
Original assignee: Comind SpA
Current assignee: Comind SpA
Priority date: 1982-10-20
Filing date: 1983-10-18
Publication date: 1984-07-04
Also published as: ES8603685A1; NL8303611A; IT1156536B; GB8327878D0; FR2534924B1; DE3337728A1; FR2534924A1; ES526985A0; IT8268217A0; GB2132130B; BE898012A

Abstract

A method of bond moulding rubber on glass, wherein the rubber-glass bond is established while the rubber undergoes dimensional conformation and chemical change from the plastic phase into the elastic phase under the combined actions of time, heat and/or pressure. The method comprises the following steps: glass degreasing by means of organic solvents of the alphatic and/or aromatic series; application of a primer composed of a solution of natural and/or synthetic polymers in aliphatic and/or aromatic solvents; application of an adhesive composed of an organic polymer solution admixed to organic solvents; thermal conditioning; placing into a mould; and moulding on the thus processed glass an elastomeric blend formed by natural and/or synthetic polymers, inhibitors, antiozonants, mineral and/or organic fillers, plasticizers, and accelerators. The resulting product is characterized by an intimate adhesion of rubber on glass, due to mutual molecular permeation taking place between the adhesive, rubber, and glass.

Description

SPECIFICATION Method of bond moulding rubber on glass, and products obtained thereby This invention relates to a method of bond moulding rubber on glass and the products to be obtained thereby.

Known are processes for bond moulding rubber on metal supports in general, whereby the rubber is caused, during the curing step, to adhere intimately on the metal to result in a composite article of manufacture whose components become unseparable, the rubber-metal bond being unaffected by chemical and physical agents, mechanical actions, and ageing factors.

The present invention is directed to providing a method of bond moulding rubber on a glass support in general, to produce composite articles of rubber and glass, wherein in conformity with the rubber-glass bonding processes, the rubber, in adhering to the glass during the curing step, becomes intimately bonded to the latter, and wherein the bond is likewise not affected by mechanical stresses, chemical and physical agents, and ageing.

The method of bond moulding rubber on glass, according to the invention is characterized in that it consists of producing a chemical-molecul-ar bond between the rubber and glass during the dimensional conformation of the rubber and during its simultaneous transformation from the plastic phase into the elastic phase thereof caused by the combined actions of time, heat and/or pressure.

More specifically, for carrying out the method there is provided a specially formulated polymer blend and a correspondingly special primer, in percentages contained within the ranges specified here below, the method comprising the following sequential steps: - glass degreasing, - primer application, - adhesive application, -thermal conditioning, - placing into a mould, - injection, transfer, or compression moulding, - withdrawal, trimming, and finishing of the product.

According to the invention, an elastomeric blend having the following general formulation is preferably used: - one or more polymers in percentages ranging from 20% to 50% and selected from the group including: chloroprene (CR), ethylene-propylene (EPR); ethylene-propylene diene (EPDM); natural rubber (NR); polyisoprene (IR); styrene-butadiene (SBR); - non-staining antiagers and antioxidants in percentages up to 5%, which are specific for the polymers used; - reinforcing fillers andior organic charges in percentages ranging from 30% to 70%; - plasticizers in percentages from 5% to 60%; - accelerators (specific for the polymers used) in percentages from 0.5% to 3%.

For the glass degreasing step, a mixture of organic solvents is advantageously employed which comprises compounds of the aliphatic and/or aromatic series, or aqueous-base products of inorganic and/or organic nature (soapy mixtures). On completion of the degreasing step, those portions of the glass which are to be bonded to rubber are treated with a primer comprising a solution of natural and/or synthetic polymers in aliphatic and/or aromatic solvents with stabiliser and reinforcing fillers.The general formulation of the solution is as follows: - one or more polymers, in percentages ranging from 7% to 35%, selected from the group including natural rubber, chloroprene, polyisobutylene, polyethylene chlorosulphonate; - mineral and organic fillers, in percentages from 0.1% to 50%, composed of one or more compounds selected from the group including silica, aluminium and magnesium silicates, magnesium silicate, calcium carbonate, titanium dioxide, carbon black, silicon organics (organosilanes).

After drying, said primer is coated with an adhesive of conventional composition, preferably comprising an organic polymer solution in a corresponding mixture of organic solvents.

To make the invention more clearly understood, some practical examples will be given here below of how this method of bond moulding rubber on glass is performed, with reference to the accompanying illustrative drawings, where: Figure 1 is a cross-sectional view of a glass pane having a U-like peripheral seal bonded thereto; Figure 2 is a cross-sectional view of a glass pane having a seal bonded thereto which has been provided with a metal or plastics channel of the plated variety used as glass runways; and Figures 3 and 4 are cross-sectional views similar to the previous ones, illustrating the bonding to glass of rubber elements intended to cooperate with matching sheet metal members.

In the drawings, G designates the rubber element, Kthe glass, and Lthe sheet metal member. The bonding process is effected as follows.

Example I The glass K is degreased at least at the bonding region z with the rubber G, using any organic solvent of the aliphatic or aromatic series, or a mixture of such solvents. That step may be carried out with any combinations of the following known methods: immersion, brushing, ultrasonic treatment, spraying, solvent evaporation.

On completion of the degreasing step, the primer is applied on the region z concerned with the rubber bond. This is preferably done by masking off the remaining portion of the glass pane, and the primer would be applied either by brushing, or spraying, or dipping. Said primer has the following composition: Components Concentrations { /0) Polyisobutylene 20 Al and Mg silicates 40 Carbon black 5 Organo-silanes 5 Solvents 30 After drying, the region z concerned with bonding is coated with an adhesive; that coating may be effectec with the same application method as the primer. As aforesaid, the adhesive utilized may be any suitable known commercially available product, preferably an organic polymeric solution in a corresponding mixture of organic solvents.Then follows a thermal conditioning step with a duration of about 30 seconds at a temperature of about 100 C.

Thereafter, the glass, treated as above, is placed into a mould wherein the elastomeric blend is moulded with any of the following conventional moulding methods: injection, transfer, compression moulding.

The elastomeric blend utilized has the following composition: Components Concentrations ( /OJ Chloroprene 50 Antioxidant 2 Mineral fillers 30 Accelerator 2 Plasticiser 21 After curing, that blend will have the following characteristics: - density (g/cm3) 1.40 - CR (kg/cm2) 100 -AR(%) 280 - LAC (kg/mm) 2 - HS (Shore A) 60 After withdrawal, trimming and finishing steps are carried out to yield a finished product. The product is characterized by an intimate bond of the rubber to the glass due to mutual permeation of the intervening adhesive layers, together and with the rubber.

Example Il The same procedure as in Example I is followed using a primer with the following composition: - natural rubber 35% - calcium carbonate 25% - carbon black 5% - organo-silanes 5% - solvents 30% and an elastomeric blend having the following composition: - natural rubber 50% - antioxidant 1% - plasticiser 13% - organic fillers 35% - accelerator 1% Example Ill The same procedure as in Example I is followed, but using a primer which has the following composition: - polyethylene chlorosulphonate 30% -titanium dioxide 10% - carbon black 5% - organo-silanes 5% - solvent 50% and an elastomeric blend having the following composition:: - styrene butadiene 22.5% - polyisoprene 22.5% - mineral fillers 35% - plasticiser 14% - accelerator 1% Example IV The same procedure as in Example I is followed, but using a primer with the following composition: - chloroprene 15% - silica 40% - carbon black 5% - organo-silanes 5% - solvent 35% and an elastomeric blend having the following composition: - ethylene-propylene-diene 30% - antioxidants 3% - organic fillers 30% - accelerator 2% - plasticiser 25% By the procedure of the above Examples I to IV excellent glass panes have been obtained wherein the rubber adhered intimately on the glass support; moreover, it has been found that the rubber glass bond was not affected by mechanical stresses, chemical and physical agents and ageing.

Thus the method will be particularly advantageous for example in the field of motor vehicle manufacturing, since it will be able of obviating a number of problems inherent to the installation of elastomer seals on both fixed and movable glass panes with a significantly simplified construction, economical advantages, and functional improvements.

Of course, within the same principle, the implementation details and methods may vary considerably from the foregoing illustrative description without departing from the scope of this invention.

Claims

1. A method of bond moulding rubber on glass, characterized in that it consists of producing a chemical-molecular bond between the rubber and glass during the dimensional conformation of the rubber and during its simultaneous transformation from the plastic phase into the elastic phase thereof caused by the combined actions of time, heat and/or pressure.

2. A method according to Claim 1, characterised in that it comprises the following steps: - glass degreasing with a mixture of organic solvents of the aliphatic and/or aromatic series, or with aqueous solutions of products of an inorganic and/or organic nature; - application of a primer composed of a solution of natural and/or synthetic polymers in aliphatic and/or aromatic solvents with reinforcing and/or stabilising fillers; - application of an adhesive composed of an organic polymer solution in a mixture of organic solvents; -thermal conditioning of the primed and adhesivized glass; - placing into a mould; - moulding on the thus processed glass an elastomeric blend including one or more polymers, non-staining antioxidants and antiozonants, mineral and/or organic fillers, plasticisers, and accelerators;; - withdrawal, trimming, and finishing of the resulting article of manufacture.

3. A method according to Claims 1 and 2, wherein said primer has the following general composition: - one or more polymers in percentages ranging from 7% to 35%, selected from a group including natural rubber, chloroprene, polyisobutylene, polyethylene, and chlorosulphonate; - mineral and organic fillers in percentages ranging from 0.1%to 50%, including components selected from the group of silica, aluminium and/or magnesium silicates, calcium carbonate, titanium dioxide, carbon black, and organic compounds of silicon (organo-silanes).

4. A method according to Claims 1 to 3, wherein said elastomeric blend has the following general composition: - one or more polymers in percentages ranging from 20% to 50% and selected from the group including chloroprene, ethylene-propylene, ethylene-propylene-diene, natural rubber, polyisoprene, and styrenebutadiene; - non-staining antioxidants and antiozonants in percentages up to 5%, as specific to the polymers used; - reinforcing mineral and/or organic fillers in percentages ranging from 30% to 70%; - plasticisers in percentages varying from 5% to 60%.

5. A method according to the preceding claims, wherein said primer and said elastomeric blend are employed in combination and in a given time sequence.

6. A method according to the preceding claims, wherein said thermal conditioning step has a duration time ranging from 3 to 30 seconds at a temperature in the 60 C to 140 C range.

7. A method according to the preceding claims, characterized in that there is used a single adhesive also performing the function of a primer.

8. A method according to the preceding claims, wherein the primer contains in combination at least two polymers from the group indicated.

9. A method according to the preceding claims, wherein the elastomeric blend comprises in combination at least two of the polymers from the group indicated.

10. A product obtained with the method claimed in Claim 1 and any of Claims 2 to 9, characterised in that it comprises a glass support intimately bonded to at least one rubber element, the intimate bond resulting from the application of said method being characterised by the permeation of the intervening adhesive layers with one another, the rubber, and the glass.

11. A product according to Claim 10, characterised in that it comprises a fixed or movable glass pane of a motor vehicle in connection with one or more elastomeric seals.

12. A method according to the preceding claims, substantially as herein described and illustrated with reference to the accompanying drawings.

13. A product according to the preceding claims, substantially as herein described and illustrated with reference to the accompanying drawings.