JPH05503550A - Acrylic modified epoxy resin adhesive composition with improved rheological control - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] Acrylic Modified Epoxy Resin Adhesive Composition with Improved Rheological Control This Invention relates to the use of epoxy resins in adhesive compositions with improved properties. be. The present invention also provides a physically safe material that can be used in the adhesive composition. The invention relates to a constant dispersion.

Epoxy resins are used in coatings, adhesives, fiber-reinforced laminates, composites, and Good for nonearing plastics and special applications such as potting resins and motors. have a matching characteristic spectrum. Such properties include excellent strength, toughness , corrosion resistance, solvent resistance, excellent adhesion and electrical properties, excellent dimensional stability, hardness, Adhesives are a particularly important application for epoxy resins. Adhesives based on epoxy provides not only load-bearing properties but also a protective seal, as well as high strength and waterproof properties. It offers many advantages to the end user.

Generally, epoxy resins are one-component or two-component, ambient temperature cured or heat cured. It is formulated into either a paste or an adhesive film. Other common epoxy resins Typical compounding agents include curing agents, catalysts, accelerators, fillers, pigments, reactive diluents, and non-reactive agents. Examples include reactive diluents, solvents, softeners, tougheners, extenders, and rheological control agents. can be lost.

Good rheological control is important for epoxy adhesives. epoxy adhesive shear It must be thin under stress, easy to apply to the surface, and must moisten the surface. However, after application, slumping of the adhesive bead ing) or sag can be a problem. At the same time, the ingredients must be prevented from separating.

Conventional, epoxy resin-based reinforced with insoluble dispersions of acrylic elastomers. The resulting adhesive formulations have poor rheological control and carboxyl-terminated adhesive formulations. Reinforced with reactive liquid polymers such as tajene acrylonitrile liquid polymer Epoxy resins also have certain difficulties in formulation and handling.

First of all, reinforced with reactive liquid polymers to achieve good rheological control. Conventional resins containing a considerable amount of fu+ned 5ilic a) is required. In order to achieve good rheological control, it is necessary to use more than 5% by weight. Highly loaded fumed silica is required. High concentrations of humus or other Fillers can cause wear problems, alteration of polymer properties, and reduced bond strength. Sometimes. Second, these resins have a high viscosity [at 25°C, 500.00 0-900,000 centipoise (cps) (500,000-900,00 0 mPa, s)], a large amount of fumed silica is mixed into these resins. That's difficult. Therefore, the epoxy resin reinforced with a reactive liquid polymer is Addition of diluent and let-down procedure An additional addition step such as re) is required.

Rheological control in paste-type adhesive systems for robotic dispensing This is especially important in the middle of the road. On automobile assembly lines, adhesives are measured by robots. The part with dispensed and uncured adhesive is placed in another workpiece for curing and further processing. transported to the work station. Under these conditions, the assembly line It is imperative that there is no contamination with drippings of curing adhesive.

- Satisfactory rheological control of uncured systems in dispersible epoxy resins In order to achieve this, the 11 things are that it is easy to pump and there is no stringing. Once the adhesive has been dispensed, the robot is removed. Furthermore, the type of surface (cold pressure (rolled steel, hot-dip galvanizing, electrogalvanizing, aluminum, etc.) and surface cleaning. Regardless of whether it has been wiped clean, oily, laser treated, etc.) The adhesive should stay on the surface without sagging, dripping, or dripping. It is necessary that the Most commonly - dispersible epoxy resins are cured at high temperatures let As the temperature of the adhesive increases, the viscosity of the resin decreases, increasing the wetting of the adhesive. Sex increases. However, before curing occurs, the adhesive sag at high temperatures. It is also important to avoid dripping or dripping.

In two-part paste adhesive systems, sag control is achieved in part by room temperature curing. can be fully achieved. In this case, rheological control rapidly modulates the microstructure. Achieve this by increasing its growth. Rheological control is primarily achieved through microstructural control at ambient conditions. The balance between hardening speed and dispensing speed is achieved by increasing the structure. must be maintained.

When slowly gelling a two-component adhesive, a suitable amount of microstructural growth occurs. The requirements for rheological control are the same as for corrugated adhesives. follow Therefore, handling, abrasion, and property degradation are legitimate concerns. Furthermore, the surrounding hardness The long molecular chains formed by oxidation are thought to be the cause of stringiness. this place If so, some mechanical solution (wchanical 5olut ion) is provided. Mechanical approaches are not appropriate or cannot be used. If this is not possible, the present invention also provides solutions for - not only corrugated adhesives but also two-component adhesives. provide.

Four U.S. patents cover epoxy-stable acrylics for reinforced epoxy resins. The four patents described above are U.S. Pat. No. 4,521,490, No. 4,524,181: No. 4,708.996.

No. 4.789.712. These patents cover a wide range of preferred vinyl monomers. mer and comonomer, in particular alkanols and amines having 1-18 carbon atoms. Esters with acrylic acid or methacrylic acid are listed, but for rheological control The incorporation of human cuxi-functional comonomers into the solution is not considered.

The incorporation of acrylic dispersions into paste adhesives is described in U.S. Pat. No. 4,521.4. It is described in No. 90. However, the problem of rheological control is Not treated. In particular, the formulation of dispersions containing fumed silica and their rheology. is not listed.

The invention has improved rheological control and sag resistance over known adhesives. By providing a thixotropic adhesive composition that solve some things.

The present invention provides superior The present invention is a thixotropic adhesive composition that exhibits sag resistance. More precisely, The present invention provides in-situ polymerized insoluble acrylics with multiple hydroxyl functionalities. Dispersion containing an uncured epoxy resin as a continuous phase with an elastomer dispersed therein mixing the fluid with an effective amount of a rheological control agent having multiple pendant hydroxyl groups. Including compounds. We use acrylic epoxy resin dispersions containing added hydroxyl values It has been discovered that the fluid surprisingly provides improved rheological control.

Additionally, the present invention has a lower viscosity than existing one-component or two-component reinforced epoxy resin adhesives. How to prepare adhesive compositions with better rheological control and toughness in It is the law.

The method of preparing the adhesive composition includes (a) its composition having multiple hydroxyl functionalities; The in-situ polymerized insoluble acrylic elastomer is dispersed as a continuous phase. (b) preparing a dispersion comprising a cured epoxy resin; an effective amount of a rheological control agent having pendant hydroxyl groups of process. The rheological control agents described above have relatively low viscosity levels that are easy to pump. Rheological control in bells without sagging or stringing Should be able to. Optionally, while mixing the dispersion and rheological control agent together, Epoxy resin hardeners can be added to the composition.

A method using an adhesive composition includes the step of applying the adhesive composition to a first surface; an adhesive composition disposed between the surfaces; and curing the adhesive composition. including. Also, optionally, an epoxy resin curing accelerator may be used for rapid curing. You can also

The present invention provides hydroxyl functionality added by acrylic elastomer particles. Requires new polymer-modified epoxy resins. Main machine of acrylic elastomer The ability is to improve toughness. The toughness of epoxy resin is optimized for dispersion of polymers phase selection and rheological control agents, thixotropes, fillers, hardeners, and This is accomplished by balancing the dispersed polymer phase with other additives.

Rheological control is particularly important when the hydroxyl groups of the rheological control agent are separated from the epoxy resin. This is achieved by matching the hydroxyl functionality of the dispersed polymer phase. Hido The roxyl functionality can be applied at various concentrations and has a number of different chemical structures. , preferably from a number of acrylic or polyurethane compositions. and can be grafted onto different parts of the dispersed polymer phase. .

The adhesive of the present invention has advantages such as low viscosity, high glass transition temperature, toughness, and moisture resistance. Improved rheological control and adhesion performance while maintaining reamer properties. The present invention requires A general method that reduces the amount of thixotropy required and provides reliable rheological properties. Extending the shelf life of thixotropes and reducing raw material costs.

Adhesives made according to the invention at ambient and elevated temperatures are carboxyl-free. Butadiene-acrylonitrile liquid polymers with end groups, liquid epoxy resins, and liquid reactive resins such as unmodified insoluble polymer dispersions in liquid epoxy resins. Better rheological control properties and sag control compared to conventional adhesives prepared with Show characteristics.

Adhesives made in accordance with the present invention can be used at temperatures from ambient to 450°F (232°C). It exhibits excellent sag control properties for at least several months at temperatures. Main departure For sag control, large amounts of humid silicon are used with additional diluent. Do not mix mosquitoes. Treatment based on resin composition without diluent It is possible to achieve a low viscosity that is easy to clean. The glass transition temperature is high and the moisture resistance is , which is improved compared to known epoxy resin adhesives. Also prepared according to the present invention Adhesives are an alternative to more expensive grades of hydrophilic fumed silica. More economical as inexpensive grade hydrophilic fumed silica can be used. It is also a target. Additionally, the present invention provides a method for reducing flow in paste-type reinforced epoxy adhesives. The problem of scientific control was also solved.

The present invention has immediate application in adhesive and sealant applications, particularly in structural adhesives. I can stay. Other epoxy resin applications where rheological control is important include coated engineering, civil engineering applications, laminates, composites, reinforced plastics, and electrical Electrical encapsulation is mentioned. Ru.

The present invention also provides a stable dispersion of an organic polymer in a continuous phase epoxy resin; The dispersion remains insoluble in the epoxy resin at temperatures of at least 60°C. It is characterized by The dispersed phase can undergo stepwise reactions such as cationic polymerization, anionic polymerization, or is an addition reaction, such as coordination polymerization or free radical chain addition, in which one or more monomers can be prepared by polymerizing mer. Preferably, the dispersed phase is It is a polymer of ethylenically unsaturated functional monomers polymerized in situ. Moreover, the dispersion liquid is Preferably, a dispersion stabilizer is included. Preferably the dispersion is compatible with the epoxy resin. and a portion compatible with the in-situ polymerizable insoluble acrylic elastomer. In-situ polymerized insoluble acrylic elastomer with dispersion stabilizer and hydroxyl functionality Contains a continuous phase of uncured epoxy resin with polymers dispersed therein.

In this specification and claims, the term "epoxy resin" means on average Contains more than one 1,2-epoxy group per molecule, with or without heat It can be crosslinked into its final form by chemical reactions using various curing agents. refers to a compound or mixture that Generally, the 1,2-epoxy group is represented by the acid di glycidyl residues, such groups include glycidyl ethers, glycidyl ester, or grindylamine. As an example of epoxy resin The diglycidyl ether of bisphenol A and tetraglycidyl methylene Dianiline is mentioned. Paste adhesives generally include lower viscosity epoxy resins. Uses xy resin. However, the material is a reactive diluent, i.e. Can be diluted with functional, low viscosity epoxides. Preferably epoxy wood The resin is a liquid epoxy resin at ambient temperature.

In the present invention, a polymer modified epoxy resin is used. Preferably, a large number of hydroxy An in situ polymerizable insoluble acrylic elastomer with syl functionality is used as a discontinuous phase. A dispersion containing an uncured epoxy resin as a continuous phase is used.

In this specification and claims, "in-situ polymerized insoluble acrylic elastomer publication" The term refers to the polymerization or copolymerization of vinyl monomers in a continuous epoxy resin phase. refers to the discontinuous particle phase produced by The particle phase is a stepwise reaction (condensation) , such as cationic, anionic, or coordination polymerization, or free radical chain addition. prepared by polymerizing one or more monomers in an addition reaction I can do it.

If the glass transition temperature (Tg) is below room temperature, the particulate phase is usually an elastomer. - is. In general, a low glass transition temperature, i.e., a glass transition temperature below room temperature, Contains an alkyl ester of acrylic acid or methacrylic acid as a monomer Therefore, it is obtained. Generally, acrylic acid is used. Preferably acrylic acid or The alkyl group of the alkyl ester of methacrylic acid has at least 4 carbon atoms. , more preferably 4-8 carbon atoms. Therefore, butyl acrylate and 2 - Ethylhexyl acrylate is preferred.

The dispersed phase is based on the total weight of the dispersion, as long as the epoxy resin is the continuous phase. 5-70% by weight, preferably 5-50% by weight, most preferably 5-20% by weight. % can be used. The optimum concentration of polymer dispersed phase depends on the materials used and It can be varied according to the expected end use. The dispersion is usually The dispersion is made at the intended solids level for which it is to be used. However, higher A high solids level dispersion can be prepared and diluted to the final solids level.

Dispersions are easier to prepare and may be better if dispersion stabilizers are included in the composition. It has excellent stability and other properties. Essentially, dispersion stabilizers are At least one part is compatible with the epoxy resin, and the other parts are compatible with the epoxy resin. is compatible with the in-situ polymerized insoluble acrylic elastomer. It can be any compound containing a moiety. The term "compatible" means It is meant that the moieties are miscible or soluble in the dispersed phase. preferable The dispersion stabilizer comprises at least one vinyl monomer and a vinylated epoxy resin adduct. It is a polymer of

The method for preparing the above-mentioned dispersion includes (1) adding less than half of the functional monomer to the polyepoxy (2) providing a vinylated epoxy resin adduct by reacting with ) dispersion stabilization by reacting the adduct with at least one vinyl monomer; in the step of providing a fixing agent, and (3) the presence of the dispersion stabilizer, the polyepoxide The method is characterized by a step of polymerizing the vinyl monomer in a continuous phase. alternatively , steps (2) and (3) are performed simultaneously. As a further alternative, a dispersion stabilizer may be prepared separately. and added to the polyepoxide before or during vinyl monomer addition and polymerization.

Vinylated epoxy resin adducts are reaction products of epoxy resins and functional monomers. Ru. Such functional monomers have, in addition to polymerizable double bonds, reactive groups. Ru. Preferably, the vinylated adduct is reactive towards the oxirane groups of the epoxy resin. It is produced by reacting functional monomers that are The reactive group may be, for example , active hydrogen in carboxylic acids, phenol, thiophenol, incyanate, or can be an amine group. To react functional monomers with oxirane groups The reactivity and methods described above and useful reaction parameters are known and can be easily found in the literature. By referring to previous experiments, you can make wise choices. preferably The functional monomer is an ethylenically unsaturated functional monomer. Preferred functional monomers - is a substituted carboxylic acid. Preferably, the reaction product is bisphenol A. It is an acrylic ester or methacrylic ester of glycidyl ether.

In this specification and claims, the term ``adhesive J'' refers to refers to formulations that can be combined with other substances.

In this specification and claims, the term "rheological control agent" refers to stress, refers to materials that affect the deformation and flowability of adhesives in terms of strain and time. Ru. Any acceptable level of rheological control agent can be used in the dispersion, but Generally, the rheological control agent will contain up to 10 parts by weight based on the total weight of the adhesive composition. Used at levels up to %. The effective amount of the rheological control agent is the desired level. The amount necessary to achieve adhesive deformation and flowability, and is typically determined in advance by the parties. The deformation and flow properties of such adhesives are generally will be determined primarily by specific consumer or industrial requirements; itself is different for each product.

Common rheological control agents include fumed silica, asbestos, and carbon binder. Lac, clay, and chopped Kevlar fiber 111 (chopped Kevl) ar fiber), but the carcinogenicity of asbestos and the ineffectiveness of clay Considering the nature and high cost of Kevlar fibers, the most common rheological control agents are , is commercially available from Kapobuto under the trade name "CAB-0-3IL". It's Mutonrika. In the present invention, hydrophilic fumed silica is preferred.

The unique properties of hydrophilic fumed silica include hydrogen-bonded hydroxyl groups, pendant Due to the unusual surface occupied by hydroxyl and siloxane groups There is. The pendant hydroxyl groups create a temporary three-dimensional network of particles spread out in the liquid system. Pendant hydroxy on other hydrophilic fumed silica particles to form a network This is largely due to the unique behavior of fumed silica. Contributing. Hydrogen bonds are easily broken under shear stress during mixing. , the viscosity decreases. However, these hydrogen bonds are reformed, so the viscosity is again increasing (“thixotropic”). For example, Kapot's booklet rCAE-0- 3IL” Properties and Functions of Humid Silica J (1990).

In contrast, hydrophobic fumed silica gives rise to treated fumed silica. It is reacted with a compound in order to Produce treated fumed silica Common compounds used for this purpose include dimethyldichlorosilane and hexame Examples include tildisilazane. By treatment with such compounds, hum Monoconversion of many of the surface hydroxyl groups on dosilica with other groups such as methyl groups . The remaining surface hydroxyl groups are generally attached to other hydroxyl groups by addition groups. It is effectively shielded from interaction with xyl groups. For example, Kapot's booklet rCAB-0-3ILT1'TS-720 treated fumed silica J (1990 year) reference.

The theory behind how fumed silica acts as a rheological control agent. The theory is simple, but in reality there are many additives (but hydrophilic It is much more complex, as it can interact with the liquid and reduce its effectiveness. Ru. Other additives such as diethylene glycol or glycerin can be used to Effectiveness increases.

In this specification and claims, the term "hydroxyl functionality" Refers to the presence of the droxyl chemical group (-OR). This functionality is Hydroxyethyl acrylate, hydroxypropyl acrylate and methacrylate Hydroxylate, such as hydroxybutyl acrylate and methacrylate In-situ polymerization of insoluble acrylic elastomer by adding vinyl-functionalized vinyl comonomers can be introduced into the streamer. Almost any level of hydroxyl functional bicarbonate Desired levels of rheological control can be achieved using nylcomonomers. Ru. However, in general, low levels of hydroxyl-functional vinyl comonomers are should be used to achieve good rheological control, but adversely affect other properties of the epoxy resin. It should be done to the extent that it has no impact. Therefore, the hydroxyl-functional vinyl comonomer 1-10% by weight based on the total weight of monomers added to the epoxy resin. , most preferably in an amount of 2-5% by weight.

In this specification and claims, the term "thixotropic" refers to refers to a material that gives it the ability to liquefy into a type of colloidal gel. As an example An example of this is clay.

In this specification and claims, the term "filler" refers to and inert materials used to provide hardness and reduce the cost of the product. It refers to the fee. Examples include calcium carbonate, silicates, and soft clays. can be mentioned. Use of any acceptable level of filler in the adhesive composition However, in general, fillers can be added up to Used at levels up to 50% by weight.

In this specification and claims, the term "curing" generally refers to physical or chemical Raw resin production by applying heat and/or chemicals that induce changes It refers to the transformation of something into a finished state and a useful state. "Hardening agent" The term refers to amines, amides, Mercaptans, acids, phenols, alcohols, acid anhydrides, Lewis acids, and bases refers to active hydrogen-containing compounds such as Dicyandiamide is the preferred cure It is a drug. Any acceptable level of curing agent can be used in the adhesive composition. Generally, the curing agent has a stoichiometric amount based on the active hydrogen content of the adhesive composition. In this specification and claims, the term "other additives" refers to Surfactants, antioxidants, stabilizers, colorants added to formulations subject to conditions , inhibitors, and desensitizers. Adhesives with any acceptable level of other additives Although other additives can be used in the adhesive composition, generally Used at levels up to 5% by weight, based on the total weight of the item.

“Sag” is a condition where excess or low viscosity material is applied, resulting in a drop in contact from the adherend surface. Defined as the outflow of adhesive. A common example of a sag test is the General Model General Motors Technical Bulletin published by Motors Corporation ors Engineering 5 standards Bulletin) sag test for structural adhesives, found in GM9749PJ can.

Hereinafter, the present invention will be explained in detail with reference to examples. It should not be construed as a limitation on the entire scope. In the example, all Parts and percentages are by weight unless otherwise specified.

Example 1 - Acrylic Ela with Added Hydroxyl Functionality for Rheological Control Preparation of stomer-modified dispersion With 176-186 epoxide equivalents, 9.000-11.　500 It has a viscosity of cps (9,000-11,500aIPa, s) and is Mikal Corporation Karari, E, R, T1'383 LER liquid epoxy resin marketed as Commercially available diglycidyl ether of bisphenol A (1,200g), meth Acrylic acid (15gL catalyst (0.5g, ethyltriphenylphosphonic acid in methanol) umacetate/acetic acid complex 70% solution), and hydroxyethyl methacrylate (BEMA) (15 g) in a stirrer, addition funnel, condenser, thermocouple, and nitrogen Place in a 3 liter three neck round bottom flask equipped with a nebulizer. under air atmosphere Then, while stirring, heat the resin to 120°C. Stir for an additional 60 minutes at 120°C. After stirring, the mixture was analyzed by titration with standard base to give 97% of methacrylic acid. It was found that % reacted with the epoxy resin to form a vinyl ester.

2-ethylhexyl acrylate (291g), glycidyl methacrylate (9 g), tert-butyl peroctoate-f- (3 gL and tert-butyl perhenzoate (15 g) of the mixture (monomer/initiator solution) at 120° C. for about 60 min. Add to the modified epoxy resin over a period of time. Once the monomer/initiator solution is added, The temperature is maintained at 120° C. for an additional 3 hours. Next, add tert-butyl pergenzoate. (0-6g). The temperature of the reactor was raised to 140°C and kept for an additional 2 hours. Keep at temperature. The resulting product is cooled and bottled.

The final product is a stable dispersion of acrylic elastomer in liquid epoxy resin . The product consists of insoluble acrylic rubber particles in a curable epoxy resin based resin. It has hydroxyl functionality because it has a hydroxyl group to bond to the child.

The product has a temperature of 84% at 25°C. 000cps (84,000mPa, s) and an epoxide equivalent weight of 240.

For comparison, hydroxyethyl methacrylate was not added to the epoxy resin. in epoxy resin using the same methods and materials as described in Example 1, except for Additional stable dispersions of vinyl polymers are prepared.

Comparative Example B As a further comparison, epoxide equivalent weight of 176-186, 9°00 at 25°C 0-11. Viscosity of 500 cps (9,000-11,500 mPa, s) An unmodified sample of diglycidyl ether of bisphenol A is used.

Comparative Example C As a further comparison, the epoxide equivalent weight of 172-176, 4°00 at 25°C It has a viscosity of 0-6,000 cps (4,000-6,000 alPa, s). It is commercially available from the Dow Chemical Company as ``ACTIX'' 123 epoxy resin. Diglycidyl ether of bisphenol A is used.

Unmodified epoxy resin and elastomer-modified epoxy resin, 100 parts of epoxy resin 4 parts per volume of humid silica. The formulation results are shown in Table I. vinegar.

From the data in Table I, the viscosity and rheological properties of modified and unmodified dispersions of epoxy resins are determined. It turns out that the controls are different. As seen in the table, the lowest viscosity is However, the rheological control is better when samples with modified liquid epoxy resin are obtained. do not have. Comparative Example A, which was modified without using hydroquinoethyl methacrylate, Although the viscosity increases when aqueous humidifier is added, it still maintains rheological control. It's not good for you. In contrast, Example 1 modified with hydroxyethyl methacrylate has high viscosity and good rheological control.

Example 2 - HEM, A - Preparation of adhesive based on modified liquid epoxy resin of Example 1 HEMA-modified poly(2-ethylhexyl) in composition [D, E, R, T'383 acrylate) elastomer, 375 g] - calcium carbonate (100 g), and and hydrophilic humutonica (25 g) are mixed together in a mixer. airp Rodac & Chemicals Company (Products and Ch. CG-1200 grade, which is commercially available from of dicyandiamide was used as curing agent in a stoichiometric proportion of 95%, and p,p'-methylene bis(phenyldimethylurea) catalyst per 100 parts of resin. A level of 6 parts catalyst, or 5 phr, is used to promote curing properties.

Comparative Example 1 Preparation of adhesive made from unmodified liquid epoxy tree B'a+'-M, E , R,” 383 Liquid Epor IF-N Resin (375g), Calcium Carbonate (1 00g) and hydrophilic fumed silica (25g) are blended together. CG- Cured with 1200 grade dicyandiamide at 95% stoichiometry Also used as a p,p'-methylenebis(phenyldimethylurea) catalyst, Used at a level of 5 phr to promote curing properties.

After each different storage time, dynamic strain sweep (dyna 5 train sw eep) The measurement test was carried out in one run for the adhesive compositions of Example 2 and Comparative Example. It is carried out at a constant speed of 1/sec. in Piscataway, New Chassis. Commercially available from a certain Rheometrics Inc. Fluid rheometer (Flujds Rheoe+eter) RF 7800 is used. The yield value is measured at ambient temperature.

Table II *1 Measured 7 weeks after the adhesive was blended.

*2 Measured 10 weeks after blending the adhesive.

From the data in Table II, the adhesive of Example 2 behaves more like a solid than a liquid. (that is, G' is significantly larger than G'). Example 2 The adhesive has a large yield value [yield value is 4. 55 x 10' dyne (4,55 x 1O-2N)/cm2) and is easily pumpable. Viscosity [complex viscosity (coIoplex viscosity) is at 20°C , 1.250 x 10' poise (1,250 x i03 Pa, s) has. Horizontal sag test (adhesive beads are placed parallel to the top of the table) Lay it down and then place it vertically) at room temperature with the thickest adhesive tested Beads [0.30 inch deep (08 x 10-2 m) should be at least 45 mm deep. It didn't sag for a while. In a convection oven at a temperature of 155°C, a thickness of 0.20 inch ( The adhesive beads of 0.5 x 10-” m) do not sag and can be removed in less than 30 minutes. It hardens while maintaining its shape.

In contrast, the comparative example adhesive behaves more like a liquid than a solid (i.e., G ' is significantly smaller than G'1). The adhesive of the comparative example has no yield value. Therefore, before starting the test at both room temperature and 155°C, the sag test should be carried out. It will fail.

Comparative Example E - Adhesive Based on Modified Liquid Epoxy Resin %W of Comparative Example A Poly(2-ethylhexyl acrylate in composition [D, E, R, T'383 ) Elastomer 375g], calcium carbonate (100g), 7h hydrophilic hue Mix together Mutonrika (25g). CG-1200 Great Zishianji Amides were used as curing agents in stoichiometric proportions of 95% and also p, p'- Methylenebis(phenyltmethylurea) catalyst was used at a level of 5 phr to harden the promotes oxidative properties.

In the sag test, the adhesive of Example 2 was tested in a convection oven at ambient temperature and 155°C. Both exhibit excellent sag control. Thickest adhesive bead tested [depth 0.30 inches (0.8 x 10-2 m) at ambient temperature ．． 5 months, no sagging, and 0.20 inch (0.5 x 10-2 m) adhesion The agent beads also do not hang down. In contrast, the comparative example after 30 minutes at ambient temperature Glue E, the thickest bead that did not sag, was 0.15 inches (0, 4 x 10-' m). After 24 hours at ambient temperature, the The thickest bead left with glue is 0.05 inch C (L 1 x 10- ”m), and the adhesive completely failed the 155°C convection oven test. It is.

Comparative Example F HC6227 Structural Epoxy from PPG Industries, Inc. One part of the adhesive, which is commercially available as a resin adhesive, is used as a further comparison.

Comparative Example G From American Cyanamid Company, as CYBONDT'4551G adhesive. (CYBf)ND using 1 part of commercially available adhesive as a further comparison: (trademark of American Cyanamid Company).

The adhesive of Example 2 and the adhesives of Comparative Examples E, F, and G were tested and Torsion shear strength, side impact strength, side impact strength fracture moat, T-type peel strength, and T-type Measure the peel strength failure mode.

The adhesive of Example 2 and the adhesives of Comparative Examples E, F, and G were tested. The results of some tests are shown in Tables ■-■. Unless otherwise noted, these tests , according to the standard * A37M test method.

Table■ This easy-flowing, yield-free sample has a complex viscosity very close to the steady-state viscosity. Ru.

Reoy Metrics, Pis Cataway, N.Y. trics Inc.

Fluids Rheoweter RF commercially available from ) 7800 at ambient temperature. Adhesive of Example 2 The exact yield value for It cannot be measured because it is Comparative actual measured at 0.5 rad/sec The yield value of Example G adhesive is 1,04 x 103 tines (1,04 x 1O-2 N)/c+m2 Te is present, R drop m (1, 2, 40 x10' die:/(2,40xlo-2N)/'ClO2. Yield value increases with increasing speed, so at 1 rad/s the yield value is 2. Although it is less than 40 x 10' dyne (2,40 x 1O-2N)/c02, Exceeds 1.04 x 103 dynes (1,04 x 10-”N)/cm2 it is conceivable that.

Table■ Lap shear strength test conditions for sample adhesive compositions 963 mils (1,6x I F3m) cold rolled steel (CR3) support, ground to ground, 0.5 wt% 4 mil (1x I F’　m) Galafu beads, 01 inch (2,5 x 10-3 m)/min cross Load speed, ASTM test method D-1002 table■ Test conditions 63 mil (1,6x 10-3m) CI? Charpy on S support - Impact strength, ground-to-ground, 0.5% by weight 4 mil (1xlo-'m) glass beads.

Table■ All of the failures, except for Example 2, occurred at the adhesive-support interface (thin film cohesion). It was something.

Test conditions, 63 mil (1,6 x 10-3 m) C[Charpy on iS support - Impact strength, ground-to-ground, 0.5% by weight 4 mil (1xlo-'m) glass beads.

Table■ Test conditions: 32 mil (8x 10-' m) 1/4 hardness CR3, ground to ground, 0, 5% by weight 4 mil (1 x 10-’m) glass beads, 10.0 inch (0,2 Crosshead speed of 5m)/min: ASTM Test Method D-1876 Table ζ *M failure at adhesive-support interface.

Test conditions: 32 mil (8x 10-' m) 1/4 hardness CR8, ground to ground, 0.5 Weight% 4 mil (1x 10-’m) glass beads, 10.0 inch (0,25 m) crosshead speed in /min.

abstract Superior sag made from a mixture of polymer-modified epoxy resin and rheological control agent. A thixotropic adhesive composition that exhibits resistance to corrosion. The polymer-modified dipoxy resin is Preferably, the acrylic elastomer can be used as a rheological control agent such as fumed silica. Acrylic acid in epoxy resin with additional hydroxy functionality that interacts with Youri It is a dispersion of Lyru elastomer. Acrylic resin containing additional hydroxy functionality The dispersion provides improved rheological control.

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Claims (12)

[Claims] 1. a. In-situ polymerized insoluble acrylic ether with multiple hydroxyl functionalities A dispersion containing an uncured epoxy resin as a continuous phase with a lastomer dispersed therein. and; b. Mixing with an effective amount of a rheological control agent having a large number of pendant hydroxyl groups A thixotropic adhesive composition exhibiting excellent sag resistance. 2. The dispersion further includes a portion compatible with the epoxy resin and an insoluble portion polymerized in situ. Claim 1, further comprising a dispersion stabilizer having a moiety compatible with the acrylic elastomer. adhesive composition. 3. An adhesive according to claim 1, wherein the rheological control agent is hydrophilic fumed silica. Composition. 4. A claim in which the epoxy resin is diglycidyl ether of bisphenol A. 1. Adhesive composition according to item 1. 5. The in-situ polymerizable insoluble acrylic elastomer is hydroxyethyl methacrylate. The adhesive composition according to claim 1, which is a 6. a. In-situ polymerized insoluble acrylic ether with multiple hydroxyl functionalities A dispersion containing an uncured epoxy resin as a continuous phase with a lastomer dispersed therein. a step of preparing; and b. the dispersion and the presence of a rheological control agent having a large number of pendant hydroxyl groups. The process of mixing together the effective amount 2. A method of preparing an adhesive composition according to claim 1. 7. While mixing the dispersion and the rheological control agent together, the epoxy resin hardener is 7. The method of claim 6, comprising adding a curing agent. 8. A claim in which the epoxy resin is diglycidyl ether of bisphenol A. 7. The method described in 7. 9. The in-situ polymerizable insoluble acrylic elastomer is hydroxyethyl methacrylate. 7. The method of claim 6, wherein the method is derived from a root. 10. 8. The method of claim 7, wherein the epoxy resin curing agent is dicyandiamide. 11. 7. The method of claim 6, wherein the rheological control agent is hydrophilic fumed silica. . 12. a. applying an adhesive composition to the first surface; b. Applied adhesive composition a first surface having an adhesive composition disposed between the surfaces; contacting the second surface; and c. Step of curing the adhesive composition A method using the adhesive composition according to claim 1.