JPS5817515B2 - adhesive composition - Google Patents

Description

[Detailed description of the invention] The present invention relates to an aqueous resin composition.

More particularly, the present invention relates to storage-stable, heat-responsive phenolic compositions suitable for use as brimers in adhesives that bind to natural and synthetic elastomers and hard and flexible substrates.

The use of adhesive systems to bind natural and synthetic elastomers to soft and rigid supports including the same or different elastomers and metals, natural and synthetic organic and inorganic fibers, etc. is well known.

A number of adhesive formulations have been developed to meet the operational requirements imposed by commercial considerations in bonding elastomers and flexible substrates.

Although these have had some commercial success, a single formulation has not been able to provide optimal results for all adhesive applications.

Generally, the adhesive that binds the elastomeric material and the rigid support is of the organic solvent type.

That is, the adhesive components, including film-forming additives, are dissolved or dispersed in an organic solvent.

Solvent-based adhesives are used sparingly to bind elas(-mer materials to flexible substrates, especially synthetic fiber substrates).

Although solvent-based adhesive systems are generally representative of caking for elastomeric materials, these systems suffer from several drawbacks.

One significant drawback is the high cost of solvent-based methods.

This system can only be developed through regeneration systems, which are often prohibitively expensive.

The oil that creates the solvent is becoming increasingly scarce.
As the cost of petroleum stocks is clearly ever-increasing, solvent-based adhesive systems will become even more costly.

Another disadvantage of solvent-based adhesives lies in the extensive legislation in the field of environmental protection, occupational safety and consumer material safety.

While the latter two areas generally apply to adhesive systems, the field of environmental protection regulations is primarily directed to solvent-based adhesives, as it concerns regulations on the type and amount of emissions into the atmosphere. .

Clearly, aqueous adhesive compositions, ie, those whose adhesive components are dissolved or dispersed in water, appear to be less likely to conflict with environmental protection regulations than solvent-based systems.

Water-based adhesives are known, but their use is generally applied when at least one support is porous or capable of absorbing water, which may interfere with the bonding of the adhesive film former or It must not have a water-resistance that inhibits kneading.

Due to the economic and environmental advantages offered by water-based systems, significant effort has been expended in the adhesive industry to develop water-based adhesives that can compete with solvent-based adhesives.

In general, the industry's most demanding solvent-based adhesive systems for elastomer adhesives are characterized by long shelf life.

That is, the system can be stored for indefinite periods of time without undue gelation or loss of adhesive ability.

It also has good interruption (Layo-ver) stability.

That is, a molded product can be coated with a liquid adhesive, dried, and stored for an indefinite period of time without substantially losing its adhesive properties.

Furthermore, the adhesive is heat-responsive.

That is, the active adhesive material remains inactive until the adhesive reaches a temperature at which it becomes tacky.

Particularly advantageous are adhesive compositions which satisfy these conditions and also provide adhesive strength that resists environmental degradation.

Although water-based adhesive systems have been proposed in the past that provide adequate adhesion, these systems generally suffer from stability deficiencies.

For example, even the best known water-based systems undergo gelation and loss of adhesion within approximately two weeks of preparation and must be used before this time.

Therefore, it is stable for a long time and maintains its strength during storage.
and is otherwise comparable to commercially available solvent-based adhesive systems.

There is a need for aqueous adhesive compositions that exhibit adhesive properties.

It is an object of the present invention to provide a storage-stable, heat-reactive, aqueous adhesive composition containing at least one phenolic resin, an effective amount of at least one methylene-donating crosslinking agent, and water.

Solvent-based adhesive systems containing at least one heat-reactive phenolic resole resin are conventionally used to adhere elastomers to metal substrates and as primers for adhesives for elastomers.

Resol resins can be emulsified in water, thereby providing a water-based adhesive system with good adhesion.

However, the safety of such thermoset resols in water is limited to several weeks at room temperature.

Water-based adhesive systems containing phenolic novolac resins and conventional hardeners such as hexamethylenetetramine and formaldehyde have been proposed.

Although such novolac systems offer fairly promising results with regard to adhesion, environmental resistance, stability, and/or some of them, they generally have deficiencies in one of these conditions and are therefore not suitable for commercial use. That cannot be said to be satisfactory.

In contrast to such known adhesive systems, the aqueous adhesive composition of the present invention has storage stability at room temperature for an indefinite period of time, cures at elevated temperatures, that is, is thermally responsive, and has excellent adhesive properties and environmental resistance. ζ
In this regard, they provide adhesive strength comparable to solvent-based adhesive systems.

Additionally, the compositions have highly desirable film-forming and flow resistance properties and can be used as single coat adhesives or primers for adhering vulcanizable natural and synthetic rubbers to hard and flexible substrates (cover-coated elastomer adhesives). can be used in combination with agents).

Phenolic resins suitable for the practice of this invention are selected from the group consisting of thermoplastic phenolic aldehyde condensates, commonly referred to as phenolic borac resins.

Such resins are produced by a known method in which a phenolic compound and an aldehyde are condensed under acidic to neutral conditions, with the phenolic substance present in a reaction mixture in an amount greater than the stoichiometric amount.

The scope of novolac resins also includes reaction products obtained by further condensing the produced resol resin with other phenolic compounds.

For more detailed information on novolac resins, including their production methods, see Carswell, “Phenoblast
Phenoplasts) J, Interscience Publishers, Inc., New York, N.Y., (197
4) is described in detail.

Suitable novolac resins include resinous oils as well as finely divided solids.

Novolac resins are always fusible and cannot be converted to an infusible crosslinked state by heat alone.

Novolac resins can be converted to an infusible state by the addition of crosslinking agents such as methylene donors.

A variety of phenolic compounds, namely monohydroxy and polyhydroxyphenols, can be used to prepare the phenolic novolac resins used in the practice of this invention.

These also include compounds with at least one aromatic ring, substituted derivatives thereof, as well as mixtures of such phenolic compounds.

Examples of substituents that can be substituted on the nucleus of this phenol compound include alkyl, alkoxy, amine, and halogen.

Typical phenolic compounds include, but are not limited to, phenol, p-1-butylphenol, p-phenylphenol, p-tetraphenol, p-alkoxyphenol, 0-cresol, m-cresol, Examples include 0-tritetraphenol, m-bromophenol, 2-ethylphenol, amylphenol, nonylphenol, cashew oil, resorcinol, orcinol, phloroglucinol, pyrocatechol, pyrogallol, salicylic acid, bisphenol A1 bisphenol S, and the like.

Particularly preferred novolac resins are those obtained when the phenolic precursor is comprised of:

a) At least one polyhydroxyphenol such as resorcinol, phloroglucinol, pyrogallol, etc.
00 mol% (resorcinol is particularly preferred), b) about 98 mol% of at least one polyhydroxyphenol, preferably about 60 to about 98 mol%, and about 50 to about 2 mol% of at least one monohydric phenol. ,
Preferably about 40 to about 2 mol%.

Monovalent phenolic hydrocarbon residues, ie residues containing only carbon and hydrogen atoms, unsubstituted (the nucleus may be substituted with groups such as alkoxy, amines, halogens, etc.).

) C) at least one polyhydroxyphenol about 10
from about 98 mol % to about 98 mol %, preferably from about 50 to about 98 mol %, and from about 90 to about 2 mol % of at least one monohydric phenol substituted with at least one alkyl group having a nucleus of 1 to 22 carbon atoms. mole %, preferably about 5
0 to about 2 mol %, and d) 100 mol % of at least one monohydric phenol whose nucleus is substituted with at least one alkyl group having from 1 to 22a carbon atoms.

The above mole percentages are based on the total moles of phenolic compounds.

When a pre-generated phenol resol or phenol or novolac is further reacted with a phenol compound to produce a modified novolak resin, the phenol compound to be further added is a polyhydroxyphenol and its nucleus is 1 or 2.
Preference is given to choosing from the group consisting of monohydroxyphenols substituted with an alkyl group having 2 carbon atoms.

Representative aldehydes that can be condensed with phenolic compounds to form novolac resins include, but are not limited to, formaldehyde, acetaldehyde, propionaldehyde, isobutyroaldehyde, 2-ethylbutyroaldehyde, 2-methyl Bent aldehyde, 2
- ethylhexaldehyde and compounds that decompose to formaldehyde, such as paraformaldehyde, trioxane, furfural, hexamethylenetetramine;
Acetals that release formaldehyde when heated,
Examples include benzaldehyde.

In order to make novolac resins, including those suitable for the practice of this invention, the infusible resin must be further reacted with a methylene donor or methylene bridge or linking source.

There are many organic compounds that can serve as methylene donors, including formaldehyde.

Also included are compounds that decompose into formaldehyde such as paraformaldehyde, S-trioxane, hexamethylenetetramine, anhydroformaldehyde aniline, and ethylenediamine formaldehyde, methylol derivatives of urea and formaldehyde, acetaldehyde, and furfural.

These organic compounds are believed to be capable of donating methylene because heat causes rapid crosslinking of the thermofusible novolak resin with methylene or its equivalent bond.

Although these compounds are effective in crosslinking the novolac phenolic resin adhesive systems of the present invention, they do not meet other critical requirements such as film formation, stability, etc.

The gist of the invention is thus the use of polymeric aldehyde homopolymers and copolymers as defined below as crosslinking agents.

Polymeric aldehyde homopolymers and copolymers to be used as crosslinking agents in carrying out the present invention include acetal homopolymers, acetal copolymers, and R10(7CH2O) n R2 (wherein R1 and R2 are the same or different and each is 1 to 8, preferably an alkyl group having 1 to 4 carbon atoms, n being 100 or more, preferably about 200 to about 2
000) is selected from the group consisting of polyoxymethylene ethers having a characteristic structure represented by:

The polymeric aldehyde homopolymers and copolymers are characterized by having a melting point of at least 75°C.

That is, it is essentially inert with respect to the novolac resin until it is activated by heat.

The copolymer is also characterized by being substantially completely insoluble in water below its melting point.

Acetal homopolymers and copolymers are well-known commercial products (Delrin® Acetal Homopolymer, E, 1. Dupont deNe
Ce1con® acetal copolymer, Celanese).

Polyoxymethylene compounds are also well known, and can be easily prepared by reacting monohydric alcohols having 1 to 8 carbon atoms, dihydroxy glycols, and ether glycols with polyoxymethylene glycols in the presence of an acidic melting medium. It can be synthesized.

Representative methods of making these crosslinkers are described in US Pat. No. 2,512,950.

A particularly preferred crosslinking agent for the practice of this invention is gamma-polyoxymethylene dimethyl ether.

To form the aqueous adhesive composition of the present invention, the novolak resin, curing agent, and water are combined in amounts sufficient to provide a storage-stable, heat-responsive composition comprising:

1) 100 parts by weight of at least one water-soluble or water-dispersible phenolic novolak resin; 11) an effective amount of a crosslinking agent, preferably 10 parts by weight of a novolak resin;
from about 2 to about 60, more preferably from about 5 to about 30 parts by weight per 0 parts by weight, and from about 5 to about 75, preferably from about 10 to about 60 parts by weight per novolak resin.
Sufficient amount of water to provide a dispersion having a total solids content (TSC) in the range of %.

The compositions described herein are water dilutable.

That is, each component is miscible with water alone or very well or completely with water, such as heptano and di-alkyl ethers of ethylene glycol or diethylene glycol, ethylene glycol, propylene glycol, isopropylene glycol, n-butylene glycol. , diacetone alcohol, or acetone, methyl ethyl ketone,
It is soluble or dispersible in water to which a small amount of an organic solvent such as a ketone such as methyl isobutyl ketone is added.

The water-dilutable adhesive systems of the present invention may optionally contain other well-known additives, including plasticizers, fillers, pigments, reinforcing agents, etc., in amounts commonly used by those skilled in the adhesive art. can.

To produce the adhesive compositions of the present invention, the novolak phenolic resin is preferably dissolved in water or, if water-insoluble, dispersed in water, preferably to form an emulsion, by conventional methods.

The remaining ingredients can be mixed into the aqueous novolac composition in any order and by any means so as to ultimately provide a uniformly dissolved or dispersed solution or dispersion of the adhesive material in the aqueous medium.

The insoluble solid material is desirably micronized, preferably into a colloidal adhesive composition.

The resulting liquid aqueous composition is storage stable at room temperature,
Exhibits excellent pot life and is heat activated, i.e.
Hardens by high temperature heating.

The composition also exhibits excellent interruption properties.

That is, after the composition is coated on a support and dried, it can be stored in its dry, uncured state for a long period of time, and then it can be cured with the aid of heating.

In use, the adhesive composition of the invention is applied by calendering or brushing to one or both surfaces to be adhesively bonded in a conventional manner and, after drying, is applied to the adhesive composition normally used for vulcanizing natural and synthetic rubbers. temperature range,
It is cured by heating to an elevated temperature, preferably in the range of about 135°C to about 235°C.

The adhesive system of the present invention is useful for directly adhering natural and synthetic rubbers to hard and soft substrates including metals, natural and synthetic organic and inorganic fibers, and the like.

The adhesive systems described herein are useful in combination with both solvent-based and water-based rubber adhesives to treat such rigid and flexible substrates, as well as in their basecoat compositions.

Additionally, the adhesive system of the present invention can be used in conjunction with a latex such as vinyl pyridine rubber to bind the fibers and rubber together.
L-shaped adhesive adhesives can be formed that provide effective adhesion and withstand very long lamination times.

In addition to unexpectedly good storage stability, the compositions of the invention exhibit desirable film properties.

It also has high flow resistance when used as a liquid type primary adhesive, for example for adhesion of rubber to metal, or as a primer composition as part of a two-part type, for example in an undercoat-rubber adhesive application system.

It is also highly resistant to environmental degradation.

The following examples are intended to illustrate the invention.

All parts and percentages are by weight unless otherwise indicated.

Example I A reactor equipped with a stirrer is charged with 300 parts of dry methanol and 702 parts of paraformaldehyde.

Heat the mixture to 70°C and add 0.7% I-IJ hydroxide.
1 part dissolved in 10 parts dry methanol is added.

264 parts of concentrated sulfuric acid are added to the reaction mixture.

The temperature is kept below 80° C. during the addition.

The reaction mixture is cooled to room temperature, washed with aqueous sodium hydroxide, and then heated at 60° C. for 2 hours.

The solid product was filtered and washed with aqueous sodium hydroxide;
Heat again at 60°C for 2 hours.

The reaction mixture is filtered and the solid polyoxymethylene dimethyl ether product is washed with water until the formaldehyde odor is substantially gone.

Example ■ 13.21 mol of resorcinol, 0.2 mol of P-nonylphenol and 80 mol of formalin (37% solution),
A novolac resin is produced by reaction at 90° C. in the presence of a catalytic amount of hexamethylenetetramine.

The resulting resin is dispersed in water containing 31% N, V sodium caseinate.

An adhesive composition is prepared by dispersing γ-polyoxymethylene dimethyl ether prepared by the method of Example I in an amount of 25 parts by weight per 100 parts by weight of the novolak resin into the novolac resin emulsion thus prepared.

The adhesive composition is used to apply vulcanizable acrylonitrile to unprimed grid-blasted steel.
Adhesive material containing butadiene elastomer.

This is cured at 154° C. for 40 minutes.

Perform peel adhesion, hot water resistance, and hot oil resistance tests.

Peel adhesion tests are conducted according to ASTM D-429 using Method B with a modification to 45°C.

Boiling water resistance is measured by immersing the test sample in boiling water for 2 hours.

Destruction is measured by peeling off the rubber from the metal with pliers immediately after removing the boiling water.

This test is more severe than the standard method of cooling the sample to room temperature before stripping.

For hot oil resistance, the test sample is ASTM≠1 to 1 standard oil.
Soaked at 44°C for 70 hours, cooled the sample to room temperature,
Measurement is performed by wiping off the oil from the sample and peeling off the rubber from the metal using scissors.

Rubber tear adhesive (100R) is obtained on each side.

The composition is equally effective after aging at 51°C (125°F) for 6 weeks.

These compositions remain virtually unchanged in appearance and viscosity after storage for 6 months at 51°C.

When paraformaldehyde is used in place of gamma-polyoxymethylene dimethyl ether in the adhesive, the resulting composition gels after standing overnight.

Examples ■Resorcinol-formaldehyde novolac resin (5
FR-1501a, Scienectady Chemical Co.) 1
A phenolic solution is prepared by dissolving 00 parts by weight in 295 parts of distilled water containing 12.5 parts of concentrated ammonium hydroxide solution.

A water-based adhesive composition is prepared by dispersing 25 parts of γ-polyoxymethylene dimethyl ether in the phenolic solution.

This adhesive composition is used to adhere unprimed grid blasted steel to an acrylonitrile-butadiene elastomer compound stock.

Peel adhesion and hot water resistance tests were carried out in accordance with Example (2), and the following results were obtained.

Peel strength lb/in 120 Peel adhesion Break 95R Hot water resistance 95R aAppears to be a catalytic condensation product of niresorcinol and formaldehyde with methyleneaminoacrylonitrile trimer.

Examples ■ 1.425 mol of resorcinol, 0.0 mol of cashew oil.
027 moles of formalin (37% solution) are reacted in the presence of a catalytic amount of hexamethylenetetramine to form a novolac resin.

The resulting resin was mixed with 287% N, V, caseinna) l)
Disperse with ram.

The novolak resin dispersion is formulated into an aqueous adhesive system having the following composition.

Part by weight Novolac resin dispersion 3792 Silica
19γ-polyoxymethylene dimethyl ether 25.
7 Titanium dioxide 18 Carbon black 3.9 Anionic surfactant (Tamo/l/850.

252 water (to give a total solids content of 25.8%) The water-based adhesive composition thus prepared was used as a single-coat adhesive to coat unprimed grid-blasted steel. Adhere vulcanizable acrylonitrile-butadiene elastomer (NBR).

It is also used as a metal primer to adhere natural and synthetic elastomers to metal (steel) in commercially available solvent-based coated cements.

The results are as above.

This data indicates that the water-based adhesive systems described herein are useful as single-wave primary adhesives and as brimers for rubber-to-metal bonding applications.

Furthermore, this data shows that the adhesion of the water-based adhesives of the present invention is virtually equivalent to commercially available solvent-based rubber-metal adhesive systems.

Example ■ In the presence of a catalytic amount of hexamethylenetetramine, cashew nut oil and resorcinol are reacted with formaldehyde at a molar ratio of phenolic compound:formaldehyde of 1,70 to produce a phenolic novolak resin (67% cashew nut oil/933% resorcinol). get.

The resin is emulsified with sodium caseinate to obtain an emulsion with a total solids content of 40% based on the novolak resin.

A water-based adhesive composition is formulated from the resin thus prepared as follows.

Composition AB Novolac Resin 9080 γ-Polyoxymethylene Dimethyl Ether 10 20 Water (40% TSC for novolac resin) Adhesive composition was used to prime vulcanizable Acryloni I-IJ loop diene rubber compounded stock. Does not adhere to Grisoto blasted steel.

The adhesive is cured at 154° C. for 40 minutes.

One test each for peel adhesion, hot water resistance, and hot oil resistance is conducted according to the method of Example H.

The results are shown in the table below.

Peel strength: 2
05 A 84 90R100R85RB
104 100R100R100R This data shows that the water-based adhesives of the present invention provide adhesive performance at least equivalent to commercially available solvent-based rubber-to-metal adhesives.

Example ■ Resorcinol and nonylphenol are reacted with formaldehyde in the presence of a catalytic amount of hexamethylenetetramine at a molar ratio of total phenol:formaldehyde of 17:1 to form a novolac cocondensation resin (97 mol% resorcinol/3 mol% nonylphenol). get.

Wash solid resin to remove formaldehyde odor.

Vacuum dry the wet resin.

Emulsion A is prepared by dispersing the dry resin in water with 40% N, V, sodium caseinate.

In the presence of a catalytic amount of hexamethylenetetramine, resorcinol and cashew oil were reacted with formaldehyde at a total phenol:formaldehyde molar ratio of 17:1 to form a novolac cocondensation resin (968 mol% resorcinol/3.2 mol% cashew nut oil).

This resin is washed to remove formaldehyde odor.

Divide the wet resin into three equal parts and vacuum dry one half.

The wet and dry resins are separately dispersed in water with 40% N, V, sodium caseinate to give emulsions B and C, respectively.

Using the emulsion thus prepared, an aqueous adhesive composition is obtained according to the following recipe.

Adhesive 111111 Emulsion A 100a --Emulsion B-100a --Emulsion C-100a γ-polyoxymethylene.

5 25 25 dimethyl ether water bbb a - Part by weight of novolac resin b = Sufficient amount of water to give 45% TSC The adhesive composition thus prepared was used to prepare untreated vulcanizable acrylonitrile-butadiene elastomer compounded stock. and adhesion to treated cold rolled steel.

Cure the adhesive at 154°C for 40 minutes.

Peel adhesion and environmental resistance (soaked in boiling water for 2 hours, 149
Soaked in hot oil for 70 hours at 5°C, then 100% relative humidity
% sodium chloride spray).

The results are shown in the table below. These data demonstrate that the aqueous systems of this invention provide excellent adhesion and environmental resistance.

As is generally the case, adhesion will be enhanced if the substrate is clean or has undergone some treatment prior to applying the adhesive.

Example 2 A cashew oil/resorcinol/formaldehyde novolak resin is prepared and emulsified according to the method of Example V.

A water-based adhesive composition is prepared by dispersing 25 parts of γ-polyoxymethylene dimethyl ether per 100 parts of novolak resin in this resin emulsion.

The initial pH of this adhesive system is 6.4.

The pH of the aliquot was adjusted to 6.0 with concentrated sodium hydroxide solution.
6, 6.8, 7.0, 7.2, 7.4, 7.
Adjust to 8 and 8.0.

Using the resulting adhesive, the solvent-wiped grid-blasted steel is hand-laid onto the acrylonitrile-butadiene elastomer compound material.

The results are shown in the table below. Adhesion pH breakdown lb/in 6.6 100 99R 6,8132SB 100R 7,010010OR 7,210399R 7,410110OR 7,612310OR 7,89910OR 8,0908OR This data shows that over a wide pH range of this aqueous adhesive system, This shows that adhesion results can be obtained.

Generally the pH will not exceed 7.9, preferably about 6
．． 2-7.7, most preferably about 6,4-7.0
It is.

Example (2) According to the method of Example (2), cashew oil, resorcinol and formaldehyde are reacted to obtain novolac resins consisting of 7 mol% cashew oil and 937 mol% resorcinol and having various phenol:formaldehyde ratios.

The resin is divided into aliquots and emulsified with sodium caseinate according to the method of Example 2.

Prior to emulsification, some of the aliquots are dehydrated.

A water-based adhesive composition is made from each part according to the method of Example ①.

This composition is used to adhere vulcanizable acrylonitrile-butadiene elastomer to solvent-stripped grid-blasted steel.

The results are shown in the table below.

Novolac dehydration Room temperature tensile strength Boiling water p/Fa
Resin 1VIn destruction 151 None 98 98R95RJ, 51
Yes 113 100R100R1,94 No
105 80R- 1,94 Yes 107 57R100R Novolac Dehydration Room Temperature Tensile Strength Boiling Water p/Fa Resin lb/ln Break 170 No 126 100 R100R1,7
0 present 125 100R100Ra-total phenols:
Formaldehyde Ratio This data shows that excellent adhesion can be obtained over a wide range of phenol:formaldehyde ratios.

Best results are obtained with dehydrated resin, but wet resin also provides excellent adhesion.

Generally, the phenolic:formaldehyde ratio is 1.1-
The range is 4:1, most preferably 1.4-2:1.

No benefit was seen for ratios greater than 4:1. Example V Several novolac resins were prepared and emulsified according to the method of Example ①.

Some of the resin was dehydrated prior to emulsification.

This emulsion is used to formulate an aqueous adhesive system according to the method of Example 2.

This adhesive is used to adhere vulcanizable acrylonitrile-butadiene elastomer to solvent-wiped grid-blasted steel and phosphate-treated steel.

The results are shown in the table below. This data shows that the adhesive system of the present invention has excellent flexibility in terms of physical formulation.

EXAMPLE

The resulting resin is emulsified in water with sodium caseinate to a total solids content of 288.

This resin emulsion is used to formulate a water-based tire cord immersion adhesive having the following composition.

Parts by weight Styrene-butadiene-vinylpyridine latex 60
b Novolac resin emulsion 36
bγ-polyoxymethylene dimethyl ether 25
Add water to make TSC 32.1%.

a-Guttrite 2828 Emulsion.

B.F. Guttrich Chemical Company b - Parts by weight of resin solids This adhesive was used to adhere a vulcanizable SBR elastomer-containing material to nylon, and the following results were obtained.

Peel Adhesion 13 b s/in 65-70 After aging the adhesive at 52°C for 6 weeks, adhesion of the SBR elastomer compounded material to nylon was repeated with the following results.

Peel Adhesion Abs/in 88-96 A similar tire cord dip adhesive using resorcinol and hexamethylenetetramine gave virtually the same results (>701 bs in peel adhesion) when freshly prepared.
give.

However, such adhesives practically gel after aging at 52°C for two weeks.

Example M/Several water-based adhesive systems are made from a hollow phenolic resin and the following methylene donor surface.

The methylene donor is hexamethylenetetramine, formaldehyde, paraformaldehyde, trioxane,
Trimethylolphenol, methylaziridinylphosphine oxide, trimethylol cyanurate, tris(hydroxymethyl)nitromethane, xamethylenediamine carbamate, hydroxymethyl diacetone acrylamide, poly-(N-methylol acrylamide), poly(vinylpyrrolidone) ), poly(hydroxymethyl diacetone acrylamide), adduct of 2-amino-2-methyl-1-fluoropanol and formaldehyde,
Adduct of tris(hydroxymethyl)amitumecune and formaldehyde, triethylenemelamine, methoxymethylmelamine, dimethylolethyleneurea, hexamethoxymethylmelamine, dihydroxymethylolethyleneurea, butylated dimethylolethyleneurea, urea-formaldehyde condensate, ethylene- They are a urea-formaldehyde condensate and a melamine-formaldehyde condensate.

In none of the examples is a satisfactory combination of properties including adhesion, environmental resistance, film formation and system stability.

From the foregoing examples, a versatile, shelf-stable, heat exchangeable, aqueous composition has been developed that is useful as a single-coat primary adhesive and as part of a two-part brimer coating adhesive system. I understand that.

It is also understood that not all combinations of ingredients have the same effect, and that each combination may be adjusted to achieve optimal performance.

Example ■ Emulsion A of Example ■ is used to prepare an aqueous adhesive composition according to the following recipe.

Adhesive ■-A■-B Emma/L/Shore A 100a 10
0a Polyacetal 25b -γ-Polyoxymethylene-25C Dialkyl ether water c d
a: Formalte' human-ethyleneoxy copolymer (Celcon registered trademark M-90, Celanese Company) b: 2 gamma-polyoxymethylene isopropyl methyl ether c: Sufficient amount of water to give 25% TSC d: 45% T
A sufficient amount of the resulting adhesive composition to provide SC is used to adhere a vulcanizable acrylonitrile-butadiene elastomer blended stock to solvent-stripped Glyph 1-blasted cold rolled steel.

The adhesive was cured at 154°C for 40 minutes.

Seven peel tests were conducted and the following results were obtained.

Adhesive tlJ Release Room temperature tensile strength failure lb/i
n ■-A 90 80R ■-B
116 100R This data shows that polymeric polyacecules and gamma-polyoxymethylene dialkyl ethers are effective in providing superior adhesive systems according to the present invention.

Claims (1)

[Scope of Claims] 1(a) at least one at least water-dispersible novolak phenolic resin; (b) acetal homopolymers, acecool copolymers, and gamma polypolymers having a characteristic structure represented by the formula %. oxymethylene ethers (wherein R1 and R2 are the same or different and each has 1 to 8 carbon atoms,
n is at least 100. ) an effective amount of at least one methylene donor selected from the group consisting of: and (C) water, the amount of water ranging from about 5 to about 75 percent total solids based on the novolak; A heat-responsive aqueous adhesive composition sufficient to provide an aqueous dispersion having an adhesive content. 2. The composition of claim 1, wherein the amount of methylene donor ranges from about 2 to about 60 parts by weight per 100 parts by weight of novolac resin. 3. The composition according to claim 2, wherein each of R1 and R2 is methyl. 4. The novolac resin is (a) a novolac resin in which the phenol precursor is comprised of 100 mole percent of at least one polyhydroxyphenol; (b) the phenol precursor is comprised of from about 50 to about 98 mole percent of at least one polyhydroxyphenol; and about 50 to about 2 mol% of at least one monohydric phenol, and the core of the -hydric phenol is not substituted with a hydrocarbon residue (C) A novolac resin (C) in which the phenol precursor is at least one polyhydric phenol about 10 to about 98 mol% and at least about 90 to about 2 mol% of monohydric phenol;
(d) a novolac resin in which the core of the -valent phenol is substituted with at least one alkyl group having from 1 to 22 carbon atoms; Novolak resin (e) substituted with at least one alkyl group having from 1 to 22 carbon atoms Modified novolak resin produced by further reacting a pre-produced phenol sol resin with a phenol precursor (the above mole percentages are 1. The composition of claim 1 selected from the group consisting of: 1 based on total moles of precursor. 5. The composition according to claim 4, wherein the main body before the phenol comprises 100 mol% resorcinol. 6. The composition of claim 5, wherein the amount of methylene donor ranges from about 2 to about 60 parts by weight per 100 parts by weight of novolac resin. 7. The composition of claim 6, wherein R1 and R2 are each methyl. 8. The composition of claim 6, wherein the phenol:aldehyde ratio is in the range of about 1.4-4:1. 9 The phenol precursor is resorcinol about 50-9
5. The composition of claim 4, wherein the composition comprises about 8 mole % cashew oil, about 50-2 mole % cashew oil, and wherein the phenol:aldehyde ratio is in the range of about 1.4-4:1. 10. The composition of claim 9, wherein 10R1 and R2 are each methyl. 11 The phenol precursor is about 50% resorcinol
5. The composition of claim 4, comprising about -98 mole percent nonylphenol and about 50-2 mole percent nonylphenol, with a phenol:aldehyde ratio in the range of 1.4-4:1. 12. The composition of claim 11, wherein RI and R2 are each methyl. 13. Claim 1, wherein the novolac phenol resin comprises a cashew nut oil-modified phenol resol.
Compositions as described in Section.