WO2014172128A1 - Adhesive compositions, manufacture and use thereof - Google Patents
Adhesive compositions, manufacture and use thereof Download PDFInfo
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- WO2014172128A1 WO2014172128A1 PCT/US2014/033124 US2014033124W WO2014172128A1 WO 2014172128 A1 WO2014172128 A1 WO 2014172128A1 US 2014033124 W US2014033124 W US 2014033124W WO 2014172128 A1 WO2014172128 A1 WO 2014172128A1
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- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
- C09J163/00—Adhesives based on epoxy resins; Adhesives based on derivatives of epoxy resins
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
- C08G59/00—Polycondensates containing more than one epoxy group per molecule; Macromolecules obtained by polymerising compounds containing more than one epoxy group per molecule using curing agents or catalysts which react with the epoxy groups
- C08G59/18—Macromolecules obtained by polymerising compounds containing more than one epoxy group per molecule using curing agents or catalysts which react with the epoxy groups ; e.g. general methods of curing
- C08G59/182—Macromolecules obtained by polymerising compounds containing more than one epoxy group per molecule using curing agents or catalysts which react with the epoxy groups ; e.g. general methods of curing using pre-adducts of epoxy compounds with curing agents
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
- C08G59/00—Polycondensates containing more than one epoxy group per molecule; Macromolecules obtained by polymerising compounds containing more than one epoxy group per molecule using curing agents or catalysts which react with the epoxy groups
- C08G59/18—Macromolecules obtained by polymerising compounds containing more than one epoxy group per molecule using curing agents or catalysts which react with the epoxy groups ; e.g. general methods of curing
- C08G59/182—Macromolecules obtained by polymerising compounds containing more than one epoxy group per molecule using curing agents or catalysts which react with the epoxy groups ; e.g. general methods of curing using pre-adducts of epoxy compounds with curing agents
- C08G59/186—Macromolecules obtained by polymerising compounds containing more than one epoxy group per molecule using curing agents or catalysts which react with the epoxy groups ; e.g. general methods of curing using pre-adducts of epoxy compounds with curing agents with acids
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
- C08G59/00—Polycondensates containing more than one epoxy group per molecule; Macromolecules obtained by polymerising compounds containing more than one epoxy group per molecule using curing agents or catalysts which react with the epoxy groups
- C08G59/18—Macromolecules obtained by polymerising compounds containing more than one epoxy group per molecule using curing agents or catalysts which react with the epoxy groups ; e.g. general methods of curing
- C08G59/40—Macromolecules obtained by polymerising compounds containing more than one epoxy group per molecule using curing agents or catalysts which react with the epoxy groups ; e.g. general methods of curing characterised by the curing agents used
- C08G59/42—Polycarboxylic acids; Anhydrides, halides or low molecular weight esters thereof
- C08G59/4246—Polycarboxylic acids; Anhydrides, halides or low molecular weight esters thereof polymers with carboxylic terminal groups
- C08G59/4253—Rubbers
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
- C08G59/00—Polycondensates containing more than one epoxy group per molecule; Macromolecules obtained by polymerising compounds containing more than one epoxy group per molecule using curing agents or catalysts which react with the epoxy groups
- C08G59/18—Macromolecules obtained by polymerising compounds containing more than one epoxy group per molecule using curing agents or catalysts which react with the epoxy groups ; e.g. general methods of curing
- C08G59/40—Macromolecules obtained by polymerising compounds containing more than one epoxy group per molecule using curing agents or catalysts which react with the epoxy groups ; e.g. general methods of curing characterised by the curing agents used
- C08G59/42—Polycarboxylic acids; Anhydrides, halides or low molecular weight esters thereof
- C08G59/4246—Polycarboxylic acids; Anhydrides, halides or low molecular weight esters thereof polymers with carboxylic terminal groups
- C08G59/4261—Macromolecular compounds obtained by reactions involving only unsaturated carbon-to-carbon bindings
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
- C08K5/00—Use of organic ingredients
- C08K5/16—Nitrogen-containing compounds
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
- C08L13/00—Compositions of rubbers containing carboxyl groups
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
- C08L13/00—Compositions of rubbers containing carboxyl groups
- C08L13/02—Latex
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
- C08L63/00—Compositions of epoxy resins; Compositions of derivatives of epoxy resins
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
- C08L9/00—Compositions of homopolymers or copolymers of conjugated diene hydrocarbons
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
- C08L9/00—Compositions of homopolymers or copolymers of conjugated diene hydrocarbons
- C08L9/02—Copolymers with acrylonitrile
-
- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
- C09J109/00—Adhesives based on homopolymers or copolymers of conjugated diene hydrocarbons
-
- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
- C09J109/00—Adhesives based on homopolymers or copolymers of conjugated diene hydrocarbons
- C09J109/02—Copolymers with acrylonitrile
-
- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
- C09J113/00—Adhesives based on rubbers containing carboxyl groups
-
- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
- C09J113/00—Adhesives based on rubbers containing carboxyl groups
- C09J113/02—Latex
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
- C08L2205/00—Polymer mixtures characterised by other features
- C08L2205/02—Polymer mixtures characterised by other features containing two or more polymers of the same C08L -group
Definitions
- the present invention relates to a new adhesive composition having unique properties in some automotive related applications such as hem-flange bonding.
- Crash durable adhesives can be used in body structure of a car to offer improved crash resistance, fatigue durability, and increased body stiffness. They can also be used for hem-flange bonding in closures like hoods and doors. Hem-flange bonding is a process wherein an outer sheet metal is hemmed around an inner sheet metal to make a joint part for a car. Adhesives are used in this process between the two sheet metals. The detailed process of hem flange bonding has been described in U.S. Patent Application
- meander formation during curing of the adhesives has been a challenging issue to the industry.
- the formed meander can lead to cracks in the joint.
- the resulted cracks can then lead to other more serious damages such as water intrusion into the joint which ultimately leads to corrosion issues over time.
- the present invention provides a novel adhesive composition with excellent heat stability and improved tackiness. Use of the adhesive composition of the present invention significantly reduces meander formation in a joint part.
- the present invention provides an adhesive composition that contains one or more rubber components, preferably, carboxylated acrylonitrile butadiene rubber-epoxy adducts ("XNBR-epoxy adducts).
- XNBR-epoxy adducts carboxylated acrylonitrile butadiene rubber-epoxy adducts
- the present invention provides an adhesive composition by mixing XNBR-epoxy adducts with a typical, commercially available crash durable adhesive composition.
- the adhesive composition comprises a liquid epoxy resin; a toughener; a curing agent; and a rubber-epoxy adduct component with a Mw valve above 60,000 Da.
- the rubber-epoxy component of the present invention comprises carboxylated nitrile butadiene rubber-epoxy adducts.
- the adhesive composition further comprises a solid epoxy resin.
- a crash durable adhesive composition typically contains a liquid epoxy resin (for example, DERTM 330 or DERTM331 available from The Dow Chemical Company), a solid epoxy resin (for example, DERTM 671 also available from The Dow Chemical Company), a blocked polyurethane based toughener (for example, polyphenolic blocked polyurethane "PU” as described in US 5,278,257, incorporated herein in its entirety, and second-amine blocked PU as described in US 20060276601A1, incorporated herein in its entirety), a curing agent such as dicyandiamide, an accelerator (for example, polymeric blocked tert- amine as described in WO2012/006001A2, incorporated herein in its entirety).
- a liquid epoxy resin for example, DERTM 330 or DERTM331 available from The Dow Chemical Company
- DERTM 671 also available from The Dow Chemical Company
- a blocked polyurethane based toughener for example, polyphenolic blocked polyurethane "PU” as described in US 5,278,257
- Such adhesive composition may also include other typically, well known in the industry, and routinely used components such as fillers, thixotropic agents, wetting agents, colorant adhesion promoters (for example, epoxy silanes), and/or special fillers such as metal to achieve conductivity.
- fillers typically, well known in the industry, and routinely used components such as fillers, thixotropic agents, wetting agents, colorant adhesion promoters (for example, epoxy silanes), and/or special fillers such as metal to achieve conductivity.
- the present invention includes a rubber component in a crash durable adhesive composition. It is suspected that meander formation and the resulted damages in the joint occur during the curing of the crash durable adhesives under heat. This may have been induced by thermal stresses in the joint due to different thermal expansion rates in multiple material structures.
- the present invention provides an adhesive composition with higher molecular weight XNBR-epoxy adducts so that the composition will have a rubbery nature. With the rubbery nature of the adhesive composition used, meander formation can be successfully avoided or significantly reduced, hence a significant better hem-flange bonding performance.
- rubber-epoxy adduct such as liquid XNBR-epoxy adducts
- a rubber-epoxy adduct such as a liquid XNBR- epoxy adduct
- the new composition preferably contains about at least about 4 wt , preferably at least about 8 wt and more preferably at least about 12 wt , of the rubber-epoxy adduct.
- Many such liquid XNBR-epoxy adducts may be used in the present invention.
- the rubber-epoxy adduct typically contains 1 to 15 wt , preferably 3 to 10 wt , of rubber elastomer and at least of about 1 wt , preferably about 5 wt of the higher molecular weight elastomers.
- the rubber elastomer can be either high molecular weight XNBR or a combination of high and lower molecular weight XNBR-rubbers (such as carboxylated acrylonitrile rubbers, CTBNs) at different ratios.
- the amount of XNBR in the adduct should preferably be no more than 7 wt based on the total weight of the adduct. If a combination of carboxyl-terminated liquid butadiene-acrylonitrile ("CTBN") rubber elastomers and XNBR rubber elastomers are used in the adduct, the total rubber amount in the adduct can be higher because of the lower viscosity of the CTBN rubber over the XNBR rubber.
- CBN carboxyl-terminated liquid butadiene-acrylonitrile
- the total rubber-elastomer amount in adduct can be less than 15 wt , preferably, less than 10 wt of the total weight of adduct. Above these levels, the adhesive viscosity will be too high to use in the desired applications.
- the preferred rubber component of the liquid XNBR-epoxy adducts suitable for the present invention typically will have a high viscosity of above 50,000 mPa- s at 25 °C, preferably above 300,000 mPa- s, and more preferably above or close to 500,000 mPa-s. While there is no particular preferred upper viscosity limit, as a practical matter, the person of ordinary skill in the art will recognize that viscosities less than about 600,000 mPa-s are preferred for processing reasons.
- Their molecular weight (“Mw”) should be above 60000 Da, more preferably above 80,000 Da and most preferable above 100,000 and the Mn should be above 10000 Da, more preferably above 40,000 Da. While there is no preferred upper molecular weight, as a practical matter, the Mw will generally be less than about 200,000 Da.
- the preferred liquid XNBR-epoxy adducts used in the present invention may include:
- Nipol® DN 601, 1470, N34J or DN 631 available from Zeon Corporation;
- Albipox® 8001 available from Evonik which is a composition comprising a liquid rubber modified epoxy resin based on Bisphenol-A-diglycidyl ether (DGEBA).
- Albipox® 8001 also contains a combination of XNBR and CTBN rubber at a weight ratio of about 7:1 and at a total amount of about 10 wt based on the total weight of the composition of Albipox® 8001.
- Struktol® 3691 available from Schill & Seilacher which is a nitrile rubber modified epoxy resin based on DGEBA. It contains about 5 wt of XNBR rubber.
- Struktol® 3693 also available from Schill & Seilacher which is a nitrile rubber modified epoxy resin based on Bisphenol-F-diglycidyl ether (DGEBF). It contains about 5 wt of XNBR rubber.
- Struktol® 3695 also available from Schill & Seilacher which is a nitrile rubber modified epoxy resin based on DGEBA. It contains a combination of XNBR and CTBN rubber of about 1:1 weight ratio at a total amount of about 10 wt of the composition of Struktol® 3695.
- Struktol® 3604 or 3614 both also available from Schill & Seilacher, which is a nitrile rubber modified epoxy resin based on DGEBA. Both contain about 40 wt of XNBR. These two XNBR-modified epoxy resins have relatively low Mw and are used in this invention only in the comparative samples to illustrate the preferred ranges desired for the present invention.
- Sample Cone 4-5 mg/ml up to 3000; 3 mg/ml 3000-50000, about 1 mg >50000
- Lap shear strength tests are performed following DIN EN 1465: 10x25 mm adhesive bonding area; adhesive layer thickness 0.2 mm.
- the test method disclosed in EP2134799B1 for analyzing meander formation is used. Specifically, 0.3 g of the adhesive composition is applied at 50°C on a hot dipped zinc coated steel panel to form an adhesive layer. A piece of rubber of thickness 0.2 mm is placed in each corner to simulate rebound. An identical panel is placed on top of the applied adhesive composition layer and is pressed by hand. Subsequently, this assembly is cured in a convection oven at 175°C for 25 min. The cured assembly is then broken by means of a wedge and the fracture is assessed qualitatively. A scale of 0 to 100% is used in the observation of meander formation from this test with 100% suggesting no meander formation and 0% suggesting large scale unacceptable meander formation.
- Table 1 illustrates the sources (suppliers) of raw materials used in making the samples of present invention and comparative samples known in the art.
- the blocked PU toughener is a secondary- amine blocked PU toughener, disclosed as Formula I in US 20060276601 with the following procedure: 79.29 wt% dried polytetrahydrofuran or polytetra methylene ether glycol, 0.54 wt% dried trimethylolpropane , 13.29 wt% 1,6-hexamethylendiisocyanate are mixed at 85 °C to homogeneity. 0.08 wt% Snapcure 3030 (available from Johnson Matthey) is added and the mixture is allowed to react at 85 °C for 1 hour under nitrogen atmospheres.
- Tables 2 and 3 show two sets (high and low viscosity respectively) of adhesive composition samples prepared using the present invention and some comparative samples. In Table 3, only liquid epoxy resin is used. In both tables, Samples A to F are prepared as embodiments of the present invention. Samples G and H are comparative samples. The units for each component in the adhesive composition samples are in wt .
- the rubber component, the epoxy resin blend (samples Al to HI), D.E.R.TM 331 (samples Al to HI, respectively A2 to H2), the blocked PU toughener, the wetting agent and the colorant are combined and mixed vigorously for 5 minutes at 50°C (50 rpm) followed by 20 minutes (150 rpm) under vacuum at the same temperature.
- the fillers like Aerosil® 202 are then added followed by mixing for 5 minutes (50 rpm) while cooling to room temperature, and thereafter mixing for another 20 minutes (150 rpm) under vacuum.
- Amicure® CG 1200G and the curing accelerator are then added followed by mixing for 3 minutes at a mixing speed of 50 rpm and then 15 minutes at 150 rpm under reduced atmospheric conditions.
- the liquid-solid DGEBA epoxy resin mix is a combination of liquid and solid DGEBA resin like D.E.R. 331 and D.E.R.671 with a weight ratio of 70:30.
- the filler package is a combination of magnesium silicate, calcium oxide and calcium carbonate in a weight ratio of about0.06:0.53:l.
- the XNBR-modified epoxy adducts have a high viscosity at 25 °C of above 50,000 mPa- s, preferably above 300,000 mPa- s, and more preferably above 500,000 mPa- s.
- Table 5 shows the mechanical performance of the samples prepared under the present invention and of the comparative samples. It is demonstrated that the addition of XNBR-epoxy adducts into the adhesive composition will not compromise the mechanical characteristics of the adhesive compositions. In other words, with or without the added XNBR-epoxy adducts, the adhesive compositions will have similar or comparable mechanical characteristics as shown in Table 5. It is also noted that higher glass transition temperatures are observed for samples of present invention over those of the comparative samples using conventional rubber-epoxy adducts. The lower viscous samples of the present invention prepared in accordance with Table 3 show the highest TGs in general.
- Table 6 shows the viscosity test results (method of EP2134799B1) of adhesive formulations described in Tables 2 and 3 used in the present invention and comparative samples using the testing method disclosed in EP2134799B1.
- Tables 7 and 8 summarize the observations of meander formation test on various samples of the present invention (higher and lower viscosity compositions, respectively), the comparative samples and a product of prior art currently available in the market. It is demonstrated that the higher the molecular weight of the rubber-epoxy adducts used in the adhesive composition of the present invention, the better the result, that is, the less meander formation after hemming and curing.
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Abstract
The invention relates to an adhesive composition having an added component of rubber-epoxy such as XNBR-epoxy adducts. It was found that the new adhesive composition significantly reduces meander formation in the making of automotive parts.
Description
ADHESIVE COMPOSITIONS, MANUFACTURE AND USE THEREOF
FIELD OF THE INVENTION
The present invention relates to a new adhesive composition having unique properties in some automotive related applications such as hem-flange bonding. INTRODUCTION
Crash durable adhesives can be used in body structure of a car to offer improved crash resistance, fatigue durability, and increased body stiffness. They can also be used for hem-flange bonding in closures like hoods and doors. Hem-flange bonding is a process wherein an outer sheet metal is hemmed around an inner sheet metal to make a joint part for a car. Adhesives are used in this process between the two sheet metals. The detailed process of hem flange bonding has been described in U.S. Patent Application
No. 20100266809.
During the hem flange bonding process, meander formation during curing of the adhesives, for example, crash durable adhesives, has been a challenging issue to the industry. The formed meander can lead to cracks in the joint. The resulted cracks can then lead to other more serious damages such as water intrusion into the joint which ultimately leads to corrosion issues over time.
SUMMARY OF THE INVENTION
The present invention provides a novel adhesive composition with excellent heat stability and improved tackiness. Use of the adhesive composition of the present invention significantly reduces meander formation in a joint part. Specifically, the present invention provides an adhesive composition that contains one or more rubber components, preferably, carboxylated acrylonitrile butadiene rubber-epoxy adducts ("XNBR-epoxy adducts). The present invention provides an adhesive composition by mixing XNBR-epoxy adducts with a typical, commercially available crash durable adhesive composition.
In one embodiment of the present invention, the adhesive composition comprises a liquid epoxy resin; a toughener; a curing agent; and a rubber-epoxy adduct component with a Mw valve above 60,000 Da.
In another embodiment of the present invention, the rubber-epoxy component of the present invention comprises carboxylated nitrile butadiene rubber-epoxy adducts.
In yet another embodiment of the present invention, the adhesive composition further comprises a solid epoxy resin.
DETAILED DESCRIPTION OF THE INVENTION
Many crash durable adhesive compositions are well known and commercially available. For example, EP1728825A1, incorporated herein in its entirety, describes many such adhesive compositions and with one or more toughening agents in the composition. A crash durable adhesive composition typically contains a liquid epoxy resin (for example, DER™ 330 or DER™331 available from The Dow Chemical Company), a solid epoxy resin (for example, DER™ 671 also available from The Dow Chemical Company), a blocked polyurethane based toughener (for example, polyphenolic blocked polyurethane "PU" as described in US 5,278,257, incorporated herein in its entirety, and second-amine blocked PU as described in US 20060276601A1, incorporated herein in its entirety), a curing agent such as dicyandiamide, an accelerator (for example, polymeric blocked tert- amine as described in WO2012/006001A2, incorporated herein in its entirety). Such adhesive composition may also include other typically, well known in the industry, and routinely used components such as fillers, thixotropic agents, wetting agents, colorant adhesion promoters (for example, epoxy silanes), and/or special fillers such as metal to achieve conductivity.
The present invention includes a rubber component in a crash durable adhesive composition. It is suspected that meander formation and the resulted damages in the joint occur during the curing of the crash durable adhesives under heat. This may have been induced by thermal stresses in the joint due to different thermal expansion rates in multiple material structures. The present invention provides an adhesive composition with higher molecular weight XNBR-epoxy adducts so that the composition will have a rubbery nature. With the rubbery nature of the adhesive composition used, meander formation can be successfully avoided or significantly reduced, hence a significant better hem-flange bonding performance.
In a preferred embodiment of the present invention, rubber-epoxy adduct, such as liquid XNBR-epoxy adducts, is included in a crash durable adhesive composition to arrive at the new composition. For example, a rubber-epoxy adduct, such as a liquid XNBR- epoxy adduct, may be included in a typical crash durable adhesive composition. The new composition preferably contains about at least about 4 wt , preferably at least about 8 wt
and more preferably at least about 12 wt , of the rubber-epoxy adduct. Many such liquid XNBR-epoxy adducts may be used in the present invention. The rubber-epoxy adduct typically contains 1 to 15 wt , preferably 3 to 10 wt , of rubber elastomer and at least of about 1 wt , preferably about 5 wt of the higher molecular weight elastomers. The rubber elastomer can be either high molecular weight XNBR or a combination of high and lower molecular weight XNBR-rubbers (such as carboxylated acrylonitrile rubbers, CTBNs) at different ratios.
If only high molecular weight XNBR is used in the adduct, the amount of XNBR in the adduct should preferably be no more than 7 wt based on the total weight of the adduct. If a combination of carboxyl-terminated liquid butadiene-acrylonitrile ("CTBN") rubber elastomers and XNBR rubber elastomers are used in the adduct, the total rubber amount in the adduct can be higher because of the lower viscosity of the CTBN rubber over the XNBR rubber. Typically, when a combination of different rubber-elastomers is used, the total rubber-elastomer amount in adduct can be less than 15 wt , preferably, less than 10 wt of the total weight of adduct. Above these levels, the adhesive viscosity will be too high to use in the desired applications.
The preferred rubber component of the liquid XNBR-epoxy adducts suitable for the present invention typically will have a high viscosity of above 50,000 mPa- s at 25 °C, preferably above 300,000 mPa- s, and more preferably above or close to 500,000 mPa-s. While there is no particular preferred upper viscosity limit, as a practical matter, the person of ordinary skill in the art will recognize that viscosities less than about 600,000 mPa-s are preferred for processing reasons. Their molecular weight ("Mw") should be above 60000 Da, more preferably above 80,000 Da and most preferable above 100,000 and the Mn should be above 10000 Da, more preferably above 40,000 Da. While there is no preferred upper molecular weight, as a practical matter, the Mw will generally be less than about 200,000 Da.
The preferred liquid XNBR-epoxy adducts used in the present invention may include:
Nipol® DN 601, 1470, N34J or DN 631 available from Zeon Corporation;
Albipox® 8001 available from Evonik which is a composition comprising a liquid rubber modified epoxy resin based on Bisphenol-A-diglycidyl ether (DGEBA). Albipox® 8001 also contains a combination of XNBR and CTBN rubber at a weight ratio of about 7:1
and at a total amount of about 10 wt based on the total weight of the composition of Albipox® 8001.
Struktol® 3691 available from Schill & Seilacher which is a nitrile rubber modified epoxy resin based on DGEBA. It contains about 5 wt of XNBR rubber.
Struktol® 3693, also available from Schill & Seilacher which is a nitrile rubber modified epoxy resin based on Bisphenol-F-diglycidyl ether (DGEBF). It contains about 5 wt of XNBR rubber.
Struktol® 3695, also available from Schill & Seilacher which is a nitrile rubber modified epoxy resin based on DGEBA. It contains a combination of XNBR and CTBN rubber of about 1:1 weight ratio at a total amount of about 10 wt of the composition of Struktol® 3695.
Struktol® 3604 or 3614, both also available from Schill & Seilacher, which is a nitrile rubber modified epoxy resin based on DGEBA. Both contain about 40 wt of XNBR. These two XNBR-modified epoxy resins have relatively low Mw and are used in this invention only in the comparative samples to illustrate the preferred ranges desired for the present invention.
Test methods used and conditions for the samples: 1. Molecular weights of the XNPR-epoxy adducts (GPC analysis conditions)
Solvent: THF
Flow: 1.0 ml
Run Time Chromeleon: 40 min
Run Time Omnisec: 29 min
Gurad Column Plgel 5 μΐ Guard 50*7.5mm
Column: 2 * Plgel Mixed D 300*7.5mm
Column Oven 27 °C
Detector 1: Shodex RI-72
Detector 2: Viscotek Dual 270
Injection Volume: 100 μΐ
Sample Cone: 4-5 mg/ml up to 3000; 3 mg/ml 3000-50000, about 1 mg >50000
Calculation Omisec Absolute MW acc. Viscotek
2. Strength Test Substrate Description
Strength tests are performed on substrates with a combination of hot dipped coated (DX56D+Z100MB 0.75 mm thick) and electro-galvanized zinc coated steel (DC05B+ZE 75/75 0.75 mm thick).
3. Lap Shear Strength
Lap shear strength tests are performed following DIN EN 1465: 10x25 mm adhesive bonding area; adhesive layer thickness 0.2 mm.
4. Impact Peel Strength
Impact peel strength tests are performed using ISO 11343: 20x30 mm bonding area; adhesive layer thickness 0.2 mm. 5. Viscosity Tests
a) Casson Viscosity Coefficient and Yield Stress are measured on a Bohlin rheometer CS-50 at 45°C: cone-plate, 20 mm plate diameter, 4° angle. Shear rate ramp up and down from 0.1 to 20 s-1. Viscosity coefficient and yield stress are calculated using the Casson model.
b) For purposes of comparison, some viscosity tests are also performed using the same testing method disclosed in EP2134799B1. Specifically, a Bohlin rheometer CS-50 is used. Oscillation is performed at 0.01% deformation and 5 Hz at 25 °C over 200s.
Measurement of Glass Transition Temperature (Tg)
Same method disclosed in EP2134799B1 is used.
7. Meander Test
The test method disclosed in EP2134799B1 for analyzing meander formation is used. Specifically, 0.3 g of the adhesive composition is applied at 50°C on a hot dipped zinc coated steel panel to form an adhesive layer. A piece of rubber of thickness 0.2 mm is placed in each corner to simulate rebound. An identical panel is placed on top of the applied adhesive composition layer and is pressed by hand. Subsequently, this assembly is
cured in a convection oven at 175°C for 25 min. The cured assembly is then broken by means of a wedge and the fracture is assessed qualitatively. A scale of 0 to 100% is used in the observation of meander formation from this test with 100% suggesting no meander formation and 0% suggesting large scale unacceptable meander formation.
Raw material components used in the samples:
Table 1 illustrates the sources (suppliers) of raw materials used in making the samples of present invention and comparative samples known in the art.
Table 1
*The blocked PU toughener is a secondary- amine blocked PU toughener, disclosed as Formula I in US 20060276601 with the following procedure: 79.29 wt% dried polytetrahydrofuran or polytetra methylene ether glycol, 0.54 wt% dried trimethylolpropane , 13.29 wt% 1,6-hexamethylendiisocyanate are mixed at 85 °C to homogeneity. 0.08 wt% Snapcure 3030 (available from Johnson Matthey) is added and the mixture is allowed to react at 85 °C for 1 hour under nitrogen atmospheres. After one hour of reaction, 6.8 wt% diisopropylylamine is added to the mixture and the mixture is stirred for additional 60 min under nitrogen atmosphere. The mixture is then degassed for 20 min under vacuum. Reaction
proceeds until the isocyanate content ("the NCO content") is 0.0 wt measured by Fourier transmission infrared spectroscopy (FTIR).
**The curing accelerator is prepared using the method disclosed in Example 1 of WO 2012006001 A2.
Preparation of Samples
Tables 2 and 3 show two sets (high and low viscosity respectively) of adhesive composition samples prepared using the present invention and some comparative samples. In Table 3, only liquid epoxy resin is used. In both tables, Samples A to F are prepared as embodiments of the present invention. Samples G and H are comparative samples. The units for each component in the adhesive composition samples are in wt .
Equipment: planetary laboratory mixer Labmax PI (Molteni)
The rubber component, the epoxy resin blend (samples Al to HI), D.E.R.™ 331 (samples Al to HI, respectively A2 to H2), the blocked PU toughener, the wetting agent and the colorant are combined and mixed vigorously for 5 minutes at 50°C (50 rpm) followed by 20 minutes (150 rpm) under vacuum at the same temperature.
The fillers like Aerosil® 202 are then added followed by mixing for 5 minutes (50 rpm) while cooling to room temperature, and thereafter mixing for another 20 minutes (150 rpm) under vacuum.
Amicure® CG 1200G and the curing accelerator are then added followed by mixing for 3 minutes at a mixing speed of 50 rpm and then 15 minutes at 150 rpm under reduced atmospheric conditions.
Table 2
*The liquid-solid DGEBA epoxy resin mix is a combination of liquid and solid DGEBA resin like D.E.R. 331 and D.E.R.671 with a weight ratio of 70:30.
** The filler package is a combination of magnesium silicate, calcium oxide and calcium carbonate in a weight ratio of about0.06:0.53:l.
Table 3
Testing of raw materials and samples
The molecular weight and polymer dispersibility index of various XNBR-epoxy adducts are measured and summarized in Table 4.
Table 4
It is noted that all molecular weights of the tested rubber-epoxy adducts (for example, Albipox® 8001 or Struktols® 3691, 3693 and 3695) are above 60,000 Da in Mw.
The adducts in the comparative samples such as Struktol® 3604 or 3614, based on CTBN rubber (such as HYCAR X8 or XI 3 available from Emerald) have significantly lower Mw (below 13,000). The lower Mn value for the Struktol® 3695 reflects in an inferior performance as described below. In embodiments of the present invention, the adducts with a Mn value above 10,000 Da are preferred. Similarly, a Mw value of above 60,000 Da is preferred with a more preferred value of above 80,000 Da.
In preferred embodiments, the XNBR-modified epoxy adducts have a high viscosity at 25 °C of above 50,000 mPa- s, preferably above 300,000 mPa- s, and more preferably above 500,000 mPa- s.
Table 5 shows the mechanical performance of the samples prepared under the present invention and of the comparative samples. It is demonstrated that the addition of XNBR-epoxy adducts into the adhesive composition will not compromise the mechanical characteristics of the adhesive compositions. In other words, with or without the added XNBR-epoxy adducts, the adhesive compositions will have similar or comparable mechanical characteristics as shown in Table 5. It is also noted that higher glass transition temperatures are observed for samples of present invention over those of the comparative samples using conventional rubber-epoxy adducts. The lower viscous samples of the present invention prepared in accordance with Table 3 show the highest TGs in general.
Table 5
Table 6 shows the viscosity test results (method of EP2134799B1) of adhesive formulations described in Tables 2 and 3 used in the present invention and comparative samples using the testing method disclosed in EP2134799B1.
Table 6
Tables 7 and 8 summarize the observations of meander formation test on various samples of the present invention (higher and lower viscosity compositions, respectively), the comparative samples and a product of prior art currently available in the market. It is demonstrated that the higher the molecular weight of the rubber-epoxy adducts used in the adhesive composition of the present invention, the better the result, that is, the less meander formation after hemming and curing.
Table 7
All above test results indicate that when higher wt amount of XNBR-epoxy adducts are added to the crash durable adhesive compositions, a better meander formation results can be achieved. However, when the content of XNBR-epoxy adducts is too high, for example higher than 15 wt of the adhesive composition, drawbacks of the composition may occur, for example, threading and pump transferability, etc. The present invention provides such an ideal adhesive composition with proper types and amounts of rubber- epoxy adducts so that meander formation can be significantly reduced or avoided while not compromising the mechanical characteristics of the adhesive compositions.
Claims
1. An adhesive composition comprising
a) a liquid epoxy resin;
b) a toughener;
c) a curing agent; and
d) a rubber-epoxy adduct component with a Mw value above 60,000 Da.
2. The adhesive composition according to claim 1, wherein the rubber-epoxy component comprises carboxylated acrylonitrile butadiene rubber-epoxy adducts.
3. The adhesive composition according to any one of preceding claims further comprising a solid epoxy resin.
4. The adhesive composition according to any one of preceding claims, wherein the rubber-epoxy adduct component has about 1 to 15 wt of rubber elastomer.
5. The adhesive composition according to any one of preceding claims, wherein the rubber-epoxy adduct component has about 3 to 10 wt of rubber elastomer.
6. The adhesive composition according to any one of preceding claims, wherein the rubber-epoxy adduct component has a molecular weight of Mw above 80,000 and Mn above 10,000.
7. The adhesive composition according to any one of preceding claims, wherein the rubber elastomer is a combination of at least two different carboxylated nitrile butadiene rubbers.
8. The adhesive composition according to any one of preceding claims, wherein the composition comprises at least about 4 wt of the rubber-epoxy adduct component.
9. The adhesive composition according to any one of preceding claims, wherein the composition comprises at least about 8 wt of the rubber-epoxy adduct component.
10. The adhesive composition according to any one of preceding claims, wherein the composition comprises at least about 11 to 12 wt of the rubber-epoxy adduct component.
11. The adhesive composition according to any one of preceding claims wherein the rubber-epoxy adduct component has a viscosity above 50,000 mPas at 25°C.
12. The adhesive composition according to any one of preceding claims wherein the rubber-epoxy adduct component has a viscosity above 300,000 mPas at 25 °C.
13. The adhesive composition according to any one of preceding claims having a viscosity value between about 300 to about 1400 Pas.
Priority Applications (2)
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EP14724595.5A EP2986685B2 (en) | 2013-04-19 | 2014-04-07 | Adhesive compositions, manufacture and use thereof |
US14/781,349 US10150897B2 (en) | 2013-04-19 | 2014-04-07 | Adhesive compositions, manufacture and use thereof |
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US201361813680P | 2013-04-19 | 2013-04-19 | |
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Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB2528779A (en) * | 2014-06-30 | 2016-02-03 | Hexcel Composites Ltd | Adhesive compositions |
WO2016130455A1 (en) * | 2015-02-11 | 2016-08-18 | Dow Global Technologies Llc | Low temperature curable adhesives and use thereof |
EP3760686A1 (en) | 2019-07-03 | 2021-01-06 | tesa SE | Thermosetting adhesive and adhesive tape made from same |
CN113234412A (en) * | 2021-06-21 | 2021-08-10 | 上海金汤塑胶科技有限公司 | Preparation method of hot-melt polyurethane resin for bonding material |
Families Citing this family (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2024010980A2 (en) | 2022-07-08 | 2024-01-11 | Zephyros, Inc. | Storage-stable solid rubber epoxy adduct |
Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5278257A (en) | 1987-08-26 | 1994-01-11 | Ciba-Geigy Corporation | Phenol-terminated polyurethane or polyurea(urethane) with epoxy resin |
WO2005007766A1 (en) * | 2003-07-07 | 2005-01-27 | Dow Global Technologies Inc. | Adhesive epoxy composition and process for applying it |
EP1728825A1 (en) | 2005-06-02 | 2006-12-06 | Dow Global Technologies Inc. | Toughener for a structural epoxy adhesive |
US20100266809A1 (en) | 2006-12-21 | 2010-10-21 | Sika Technology Ag | Hem flange joint |
WO2012000171A1 (en) * | 2010-06-29 | 2012-01-05 | Dow Global Technologies Llc | Storage-stable heat-activated tertiary amine catalysts for epoxy resins |
WO2012006001A2 (en) | 2010-06-29 | 2012-01-12 | Dow Global Technologies Llc | Storage-stable heat-activated tertiary amine catalysts for epoxy resins |
Family Cites Families (13)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5073595A (en) † | 1987-12-23 | 1991-12-17 | Minnesota Mining And Manufacturing Company | Epoxide resin compositions and method |
US5292812A (en) † | 1990-01-24 | 1994-03-08 | The Yokohama Rubber Co., Ltd. | Adhesive of epoxy resin, CTBN and maleimide |
US5712039A (en) † | 1995-04-11 | 1998-01-27 | Minnesota Mining And Manufacturing Company | Epoxy adhesives with dithiooxamide adhesion promoters |
JPH09194803A (en) † | 1996-01-17 | 1997-07-29 | Bando Chem Ind Ltd | Adhesive tape for semiconductor |
US20040204551A1 (en) † | 2003-03-04 | 2004-10-14 | L&L Products, Inc. | Epoxy/elastomer adduct, method of forming same and materials and articles formed therewith |
GB2415162A (en) † | 2004-06-15 | 2005-12-21 | L & L Products Inc | Improvements in or relating to laminar mouldings |
KR100637322B1 (en) * | 2004-10-22 | 2006-10-20 | 도레이새한 주식회사 | Adhesive tape composition for electronic components |
GB0506404D0 (en) † | 2005-03-30 | 2005-05-04 | L & L Products Inc | Improvements in or relating to components |
US7892396B2 (en) † | 2006-06-07 | 2011-02-22 | Zephyros, Inc. | Toughened activatable material for sealing, baffling or reinforcing and method of forming same |
GB0720301D0 (en) † | 2007-10-17 | 2007-11-28 | Zephyros Inc | Multi functional vehicle components |
GB2475025A (en) † | 2009-07-28 | 2011-05-11 | Zephyros Inc | Laminate, for vehicle, includes foam layer and anchorage holes |
GB0916205D0 (en) † | 2009-09-15 | 2009-10-28 | Zephyros Inc | Improvements in or relating to cavity filling |
US9181463B2 (en) † | 2010-12-26 | 2015-11-10 | Dow Global Technologies Llc | Structural epoxy resin adhesives containing chain-extended elastomeric tougheners capped with phenol, polyphenol or aminophenol compounds |
-
2014
- 2014-04-07 WO PCT/US2014/033124 patent/WO2014172128A1/en active Application Filing
- 2014-04-07 EP EP14724595.5A patent/EP2986685B2/en active Active
- 2014-04-07 US US14/781,349 patent/US10150897B2/en active Active
Patent Citations (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5278257A (en) | 1987-08-26 | 1994-01-11 | Ciba-Geigy Corporation | Phenol-terminated polyurethane or polyurea(urethane) with epoxy resin |
WO2005007766A1 (en) * | 2003-07-07 | 2005-01-27 | Dow Global Technologies Inc. | Adhesive epoxy composition and process for applying it |
EP1728825A1 (en) | 2005-06-02 | 2006-12-06 | Dow Global Technologies Inc. | Toughener for a structural epoxy adhesive |
US20060276601A1 (en) | 2005-06-02 | 2006-12-07 | Andreas Lutz | Toughened epoxy adhesive composition |
US20100266809A1 (en) | 2006-12-21 | 2010-10-21 | Sika Technology Ag | Hem flange joint |
EP2134799B1 (en) | 2006-12-21 | 2012-02-22 | Sika Technology AG | Edging-fold bond |
WO2012000171A1 (en) * | 2010-06-29 | 2012-01-05 | Dow Global Technologies Llc | Storage-stable heat-activated tertiary amine catalysts for epoxy resins |
WO2012006001A2 (en) | 2010-06-29 | 2012-01-12 | Dow Global Technologies Llc | Storage-stable heat-activated tertiary amine catalysts for epoxy resins |
Cited By (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB2528779A (en) * | 2014-06-30 | 2016-02-03 | Hexcel Composites Ltd | Adhesive compositions |
GB2528779B (en) * | 2014-06-30 | 2017-10-04 | Hexcel Composites Ltd | Adhesive compositions |
WO2016130455A1 (en) * | 2015-02-11 | 2016-08-18 | Dow Global Technologies Llc | Low temperature curable adhesives and use thereof |
EP3760686A1 (en) | 2019-07-03 | 2021-01-06 | tesa SE | Thermosetting adhesive and adhesive tape made from same |
CN113234412A (en) * | 2021-06-21 | 2021-08-10 | 上海金汤塑胶科技有限公司 | Preparation method of hot-melt polyurethane resin for bonding material |
CN113234412B (en) * | 2021-06-21 | 2022-05-17 | 上海金汤塑胶科技有限公司 | Preparation method of hot-melt polyurethane resin for bonding material |
Also Published As
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US20170081571A1 (en) | 2017-03-23 |
EP2986685B2 (en) | 2020-05-13 |
EP2986685B1 (en) | 2017-08-09 |
US10150897B2 (en) | 2018-12-11 |
EP2986685A1 (en) | 2016-02-24 |
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