FR2539326A1 - ADHESIVE AGENT CONTAINING MICROCAPSULES AND PROCESS FOR PREPARING THE SAME - Google Patents

Abstract

THE INVENTION RELATES TO AN ADHESIVE AGENT CONTAINING MICROCAPSULES, CONSTITUTED BY MICROCAPSULES ESSENTIALLY COMPOSED OF A CORE SUBSTANCE IN AT LEAST ONE OF THE TRAINING CONSTITUENTS OF SAID ADHESIVE AGENT AND, AS A MATERIAL FORMING THE MEMBRANE OF THE MICROCAPSULES, AN AMINOPLASTE PREVIOUSLY TREATED BY A MODIFIER, AND BY A MEDIUM COMPOSED OF OTHER CONSTITUENTS OF FORMATION OF THE SAID ADHESIVE AGENT, THE MICROCAPSULES BEING DISPERSE IN THIS MEDIUM AND THE ADHESIVE AGENT BEING OF THE CHEMICAL REACTION TYPE OR OF THE SOLVENT ACTIVATION TYPE. 'A PROCESS FOR ITS PREPARATION.

Description

2559326 i Adhesive agent containing microcapsules

and its method of preparation.

  The present invention relates to an adhesive agent containing microcapsules and, in more detail, a chemical reaction type or solvent activation type adhesive agent containing in both cases microcapsules. In even more detail, the present invention relates to an adhesive agent containing

  microcapsules, which includes essential microcapsules

  actually consist of a core substance in one

  at least formation components of said adhering agent

  sif and, as a constituent material of the membrane of the microcapsule, an aminoplast previously treated with a modifiers and a medium composed of the other constituents for forming the adhesive agent, the microcapsules being dispersed in this medium and the agent The invention also relates to a process for the preparation of an adhesive agent containing microcapsules, this process comprising the dispersion operation in the other formation constituents.

  adhesive agent, microcapsules essentially

  at least one of the constituent constituents of the adhesive agent and a

  membrane formation material consisting essentially of

  an aminoplast treated with a modifier.

  Adhesive agents are sorted according to their fashion

  hardening, in the following four categories.

  1) Solvent evaporation type adhesive agent: once the agent has been applied, all the excipient such as a solvent or the water which it initially contained, Is evolved by evaporation from the end of the seal or by absorption in the materials to be bonded, and the adhesive agent membrane thus formed acquires its

maximum mechanical strength.

  2) Chemical reaction type adhesive agent A hardened adhesive membrane is formed by chemical reaction between the resin and the hardener or

  between the monomer (or oligomer) and the catalyst

  mixing the two separate components of the adhesive agent, one of which contains the resin or the monomer

  and the other contains the hardener or catalyst

  3) Solvent Activated Type Adhesive Agent: After basting the surface of the body to be bonded with adhesive agent and forming a dried membrane of the agent on the surface, a solvent is sprayed onto the surface to reactivate the surface. surface of the membrane and then we place the other body to stick on the surface of the

  membrane thus reactivated, which completes the bonding.

  4) Hot Melt Adhesive Agent: After applying the adhesive agent in the molten state to the surface of the body to be bonded, it cools

  the bodies thus treated to complete the collage.

  The chemical reaction type adhesive agent is composed of two components separated from each other which are mixed just before applying them and, consequently, an adhesive agent of this type has disadvantages: convenient to apply, there is only a limited implementation time after mixing the two components and it is necessary to throw

  the rest of mixing of the two constituents.

  On the other hand, the adhesive of the solvent-activated type poses problems of environmental pollution, industrial hygiene and safety because it obliges

  to use a large amount of organic solvent.

  In order to remedy the above-mentioned drawbacks

  Some of the conventional adhesive agents have been tried to encapsulate one of their constituents and gelatin or polyamide membrane microcapsules have been proposed. 2539326 i However, since the membranous wall

  microcapsules proposed so far is generally

  semi-permeable or with microscopic perforations,

  the constituent of the adhesive agent contained in the microparticles

  capsules may escape and, since the

  membrane wall is poorly resistant to solvents

  such as alcohols, ketones and esters,

  there is also the risk of seeing the content of micro-

  capsules escape from these under the action of such

solvent.

  In particular, with a view to using micro-

  capsules in an adhesive agent that must specifically

  solvent-resistant, it is necessary (1) that the membrane wall

  The microcapsule has excellent solvent resistance and (2) the microcapsule itself has excellent pressure sensitivity to break easily under a slight increase in pressure applied thereto; therefore, it has proven very difficult to put

  use an adhesive agent containing such microcapsules.

  Indeed, to improve the solvent resistance of

  microcapsules, a method of immersing

  the microcapsules in a basic substance to activate their surface, a method of bringing the surface into contact with a vapor of an α-cyanoacrylate and a method of coating the microcapsules with a substance resistant to the dispersion medium of the

  microcapsules in the adhesive agent to form microparticles

  However, this process has the effect of making the pressure to be applied to the microcapsules, to break during use, too important for the microcapsules thus treated can be

  used as a component of an adhesive agent.

  The object of the present invention is to provide an adhesive agent containing microcapsules with excellent solvent resistance and excellent pressure sensitivity, which adhesive agent overcomes the disadvantages of conventional chemical reaction type adhesives and of the solvent-activated type and being convenient and easy to use during application without having to use quantities

  excess of constituents of the adhesive agent.

  According to the first aspect of the present invention, there is provided an adhesive agent containing microcapsules, which comprises microcapsules essentially consisting of a core substance in at least one of the formation components of said adhesive agent and as a material.

  of microcapsules of a prior aminoplast

  moderator, and a medium consisting of the other formation components of said adhesive agent, the microcapsules being dispersed therein and the adhesive agent being of the chemical reaction type or the

solvent.

  In the second aspect, there is provided a process for preparing an adhesive agent containing microcapsules, chemical reaction type or solvent-activated type, which comprises: dispersing minute liquid particles of at least one of components of the adhesive agent in an aqueous dispersion of the formation constituents of a

  aminoplast, the addition of an acid catalyst to the

  aqueous persion, thereby causing polycondensation of the prepolymer of said

  the aminoplast, the addition of a modifier to the

  aqueous persion during or after completion of the polycondensation, thereby forming microcapsules

  encapsulating said constituent (s) in the mem-

  brane essentially constituted by said aminoplast modified by said modifier, 2539326 i collection and drying microcapsules thus formed, and

  the dispersion of the microcapsules in the other con-

  forming agents for the adhesive agent containing microcapsules.

  The characteristic aspect of the present invention

  It consists of an adhesive agent containing micro-

  chemical reaction type or activating type capsules

  solvent, said microcapsules being essentially

  composed of (1) a core substance of one or more components of the adhesive agent to be enclosed in the microcapsules and (2) as a material forming

  the membrane of the microcapsule, of a prior aminoplast

  modified by a modifier, in a system essentially consisting of the other constituents of

the adhesive agent.

  In other words, the adhesive agent containing the microcapsules, which can be of the reaction type

  chemical or solvent-activated type according to the

  in the case where it is of the reaction type, that is to say, for example, in the case where its constituents are essentially a resin and a hardener or a monomer or oligomer and a catalyst, the form an adhesive agent containing microcapsules which contain, as a component, the hardener or the catalyst (preferably in as small a quantity as possible)

  dispersed in the resin or in the monomer or oligo-

  In addition, in the case where the constituent is a multi-component system such as that consisting essentially of a monomer, a catalyst and a

  hardener, the microcapsules containing either the cat-

  the catalyst, the catalyst and the hardener, are

  persists in the monomer to prevent the reaction

  between the catalyst and the monomer, and between the hardening

and the monomer.

2539326 '

  In this connection, at least two components which do not react with one another can be encapsulated separately, but it is preferable to encapsulate at least two of these constituents simultaneously and, in addition, the catalyst can be encapsulated. or the hardener

in the dissolved state in a solvent.

  On the other hand, the adhesive agent containing microcapsules according to the invention takes, in the case where it is of the solvent-activated type, the form of an adhesive agent containing microcapsules which contain

  a solvent necessary to dissolve and activate the residence

  intended to form the bonding membrane, dispersed in a solution which contains the resin which must be brushed the surface of a material to be bonded (hereinafter referred to as "the resin solution") Therefore, according to the invention, expected it is necessary to encapsulate the smallest possible amount of solvent necessary for

  activate the resin, the problem posed by the adhesion

  current solvents of the solvent-activated type due to

  the use of a large amount of solvent, is

  ve resolved by this type of adhesive agent according to the invention.

  What is important in the encapsulation of at least one of the constituents of the adhesive agent is that the membranous wall of the microcapsule has both excellent solvent resistance and excellent

pressure sensitivity.

  Following studies by the plaintiff

  to find the proper material to form a membrane wall

  to meet the above-mentioned requirements, it was discovered that

  green than an aminoplast previously treated with a

  This indicator is suitable as a material of the type referred to above.

  noplast "is meant here a resin obtained by subjecting at least one prepolymer selected from the prepolymers of

  melamine-formaldehyde, urea-formaldehyde prepolymers

  hyde, the melamine-urea-formaldehyde prepolyners,

2539326 A

  melamine-thiourea-formaldehyde prepolymers and melamine-thiourea-urea-formaldehyde prepolymers or a mixed prepolymer containing a prepolymer of

  melamine-formaldehyde and a thiourea prepolyher-

  formaldehyde to a polycondensation in the presence of both a cationic urea resin soluble in water and

an anionic surfactant.

  The material for the membrane of the microcapsule

  according to the present invention comprises an aminoplast pre-

  trimmed by polycondensation in the presence of a modifier.

  The microcapsule formed from the aminoplast thus treated is superior in its resistance to the solvent and in its ease of flow to a microcapsule formed

  untreated aminoplast and, at the same time,

  capsule formed of the aminoplast thus treated present

  excellent sensitivity to pressure.

  As examples of possible modifiers

  such a phenolic compound may be mentioned

  such as phenol, resorcinol, catechol, hydroquinone, cresol, xylenol and saligenin

  and a polyalkylene polyamine compound such as hexamethylene

  thylenetetramine and triethylene triamine.

  In order to form the microcapsules according to the present invention, tiny liquid particles of the constituent (s) of the adhesive agent are dispersed which must be encapsulated in an aqueous liquid in which the aminoplast prepolymer, the resin of urea

  soluble cationic agent and anionic surfactant

  that, and is added to the aqueous suspension thus prepared

  acid catalyst, for example a carboxylic acid,

  only at low molecular weight such as formic acid,

  acetic acid and citric acid, an inorganic acid

  such as hydrochloric acid, nitric acid and phosphoric acid or a salt whose aqueous solution has an acidity or an easily hydrolysable salt such as aluminum sulphate, titanium oxychloride, magnesium chloride , ammonium chloride, ammonium nitrate, ammonium sulphate and ammonium acetate, then, while causing a complex coacervation by the cationic urea resin soluble in water and surfactant. anionic active material which has both been dispersed in the aqueous dispersion of the aminoplast, the water-soluble cationic urea prepolymer and resin is subjected to polycondensation to form

  a hydrophobic membranous wall with high molecular weight

  which completely covers each of the tiny liquid particles of the components of the adhesive agent which have been dispersed in the system, causing

there a microencapsulation.

  In case the above-mentioned modifier is added to the system during the polycondensation, it is formed

  a membranous capsule wall comprising 11 aminoplas-

  treated by the modifier as indicated above.

  The amount of modifier is 0.1 to 30% by weight, preferably 0.5 to 20% by weight

  prepolymer, and the modification is preferably

  in the form of an aqueous solution at a concentration

from 0.02 to 5% by weight.

  It should be noted in this connection that the water-soluble cationic urea resin used to cause complex coacervation and to prepare the aminoplast

  mentioned above is the substance obtained by introducing a group

  cationic modifier in a urea-formaldehyde resin

  dehyde, namely the polycondensation product, for example, of urea-formaldehyde prepolymer with a polyalkylenepolyamine, a guanidine, diaminoethanol,

  dicyandiamide, diethylaminoethanol and guanylurea.

  As anionic surfactant, mention may be made of substances such as those containing

  their molecule a lipophilic group and an anionic group

  hydrophilic, for example fatty acid salts, higher alcohol sulfate esters and alkylarylsulfonate salts,

  and dodecyl is preferably used, for example

  Moreover, in the polycondensation for the formation of the microcapsules according to the present invention, it is important that two kinds of substances which differ from each other by the sign of their electrical charge coexist with the prepolymer, one of them being the cationic urea resin soluble in water and the other being

  the anionic surfactant By satisfying this condition

  important, it is possible to obtain a dispersion

  stabilized aqueous solution containing microcapsules of

uniform quality.

  Whereas we can implement the

  microcapsules according to the invention in the form of powder is

  after being prepared, by easily separating them from the dispersion medium used in their preparation and drying them, and having excellent resistance to solvents, they are well suited to form the adhesive agent by uniform dispersion

  in the other constituents of this adhesive agent.

  The following is a concrete disclosure of the adhesive agent containing the microcapsules according to the present invention (1) in the case where the adhesive agent is of the chemical reaction type and (2) in the case where the agent

  The adhesive is of the solvent-activated type.

  (1) Chemical reaction type adhesive agent: To prepare the chemical reaction type adhesive agent, that is, the adhesive agent comprising a resin, a monomer or an adhesion oligomer, an agent

  reaction and a hardener, it is possible to

  any of these constituents in the micro-

  capsules and dispersing the microcapsules in a mixture of the other constituents The component to be enclosed in the microcapsules is generally chosen to contain the component present in a smaller quantity, ie the reaction initiation agent or the hardener. The kinds of constituents to encapsulate in the microcapsules may be in number not less than two and one can encapsulate at least two of these constituents, either together

ble, each one separately.

  As adhesion resin, there may be mentioned polyacrylic acid, polymethacrylic acid, a

  epoxy resin, a polyester, a polyamide, a polyurethane

  thane, a copolymer of urethane and lower alkyl acrylate or lower alkyl methacrylate, a copolymer of dicarboxylic acid, diol, and lower alkyl acrylate or lower alkyl methacrylate,

  an epoxidized poly (lower alkyl acrylate), a poly (methacrylate)

  epoxidized lower alkyl crylate), a silicone resin

  low molecular weight cone, natural rubber, neoprene rubber, polyvinyl acetate and polystyrene The microcapsules containing

  the initiator of the necessary reaction or the dura-

  in at least one resin selected from the resins mentioned above-and their adhesion monomers or oligomers or in a solution prepared by

  dissolving the selected resin in an organic solvent.

  As initiators of the reaction, mention may be made of dibutyl tin dilaurate, stannous caprylate or a solution of an organic peroxide such as benzyl peroxide and dibutyl peroxide in

  an organic solvent and, as a hardener, N, N-

  dimethylaniline, N, N-dimethyltoluidine and the like.

  In order to use the adhesive agent containing microcapsules of the chemical reaction type, this agent is sprayed with one of the surfaces of a body to be bonded, and the other body is then adhered to the first to grip the surface. brushed the first body and apply pressure to the bodies and superimposed from

on the side of the second body.

  The microcapsules then break easily to allow their contents to freely come into contact with the other constituents of which the surface of the first body is smeared, so that the hardening intervenes to ensure a strong adhesion between the two bodies. the adhesive agent containing microcapsules of the chemical reaction type on any surface by any of a variety of means such as printing, spraying, painting, etc. (2) Solvent-activated type adhesive agent:

  To prepare the active type adhesive agent,

  solvent-based, the microcapsules containing an organic solvent for activating the resin which constitutes the adhesive membrane can be dispersed in the solution of

  resin which constitutes the adhesive membrane.

  As an encapsulating organic solvent, almost all the solvents generally used are indicated and mention may be made of hexane, heptane, benzene, toluene, xylene, carbon tetrachloride,

  trichlorethylene and tetrachlorethylene.

  As the solvent-activated resin, there may be mentioned Neoprene rubber, butyl rubber, styrene-butadiene rubber, natural rubber,

  polystyrene, polyvinyl acetate, methylcellulose

  ethylcellulose, polyvinyl chloride, a copolymer of ethylene and vinyl acetate, an acrylic resin, a methacrylic resin, a polyamide, a

  copolymer of vinyl acetate and alkyl acrylate

  férieur. The solvent-activated type adhesive agent according to the present invention comprises the above-mentioned microcapsules containing the solvent as the core substance, dispersed in the resin solution.

  intended to constitute the adhesive membrane, and the resin.

  To apply the solvent-activated adhesive agent, this agent is sprayed with the surface to be bonded to one of the two bodies to be bonded and, after drying of the agent

  applied adhesive, the body is placed on the surface

  it is thus brushed on the other of the two bodies to be bonded by applying a pressure to the first body, so that the microcapsules, broken by the pressure, release the solvent so that it activates the constituent

  resin in the whitewashed surface, which

good adhesion.

  It is also possible to apply the adhesive agent containing microcapsules, of the solvent-activated type, by printing, spraying or painting.

  etc. on the surface of a body to stick to another body.

  Whereas the microcapsule used according to

  the present invention is easy to break by application.

  With a pressure of less than 10 kg / cm 2, the aforementioned adhesion between the two bodies is easily ensured by

  superposition and application of pressure.

  Therefore, the adhesive agent containing microcapsules according to the present invention has the advantage

  to be able to serve very different collages.

  A presentation of the present invention will be given

  more precise in the examples below.

  However, these examples are devoid of any

  limiting nature According to the above description,

  the person skilled in the art can easily identify the characteristics

  essential characteristics of the present invention and provide

  to it, without departing from its scope, various amendments

  and variants to suit a variety of uses and conditions,

Example 1

  1.1 Preparation of two prepolymers.

  After adjusting to pH 9.0 the pH of 162 g of a 37% aqueous solution of formaldehyde (hereinafter formol) by addition of a 2% aqueous solution of sodium hydroxide, the formalin is mixed with 63 g of melamine and the mixture is reacted with stirring at 70 ° C 2539326 i Immediately after noting the complete dissolution of melamnine in the reaction mixture, is added to it 225 g of water and stir the mixture for 3

  minutes to obtain an aqueous solution of a prepoly-

  mother of melamine-formaldehyde resin (hereinafter M 4 F prepolymer, M 4 F meaning that the molar ratio

  melamine / formaldehyde is 1/4 in the prepolymer).

  Separately, after adjusting the pH of 146 g of formalin to 8.5 by addition of triethanol amine, the formalin is mixed with 60 g of urea and the mixture is reacted for 1 hour at 70 ° C. to prepare

  aqueous solution of a urea-for-strength resin prepolymer

  maldehyde (hereinafter U 1,8 F prepolymer).

  1.2 Preparation of a cationic urea resin

  After having adjusted to 8.8 by addition of triethanolamine the pH of a mixture prepared by mixing 162 g of formalin and 60 g of urea and stirring the mixture,

  the mixture is reacted for 30 minutes under stirring.

  At 40 g of the reaction mixture, 24 g of water and 3 g of tetraethylenepentamine were added and the mixture was adjusted to 3.0% by addition of a 15% aqueous solution of water. hydrochloric acid while stirring the

  mixture at 70 C, then reacted for 1 hour.

  Whereas the pH of the reaction mixture decreases

  As the reaction progresses, we add to the reaction mixture

  10% aqueous solution of sodium hydroxide to adjust the pH to 3.0, then the reaction is continued at a reduced temperature of 55 ° C. When the viscosity of the reaction mixture is 0.2 Pa s

  (200 cps), the reaction mixture is neutralized by

  10% aqueous solution of sodium hydroxide and 400 g of water are added to the neutralized mixture to obtain an aqueous cationic urea resin solution.

soluble in water.

1.3 Microencapsulation.

  5.2 g of a mixture consisting of 100 g of M 4 F prepolymer (see 1 1), 50 g of U 1,8 F prepolymer (see 1 1), 158 g of the solution are adjusted to pH 5.2. aqueous cationic urea resin soluble in

  water (see 1 2), 62 g of water and 1 g of triethanol

  lamine, by addition of a 10% aqueous solution of citric acid, and is obtained by incorporating into the mixture 3 g of 10% aqueous solution of NEOPELEA.

  sodium dodecylbenzenesulfonate manufactured by KAO-

  ATLAS Co, Japan), a solution which will be called liquid A. In the liquid A thus prepared, ml of xylene is dispersed so that the average diameter of the

  dispersed xylene particles of between 30 and 50 micro-

  The aqueous dispersion thus obtained is reacted for one hour with gentle stirring and

  keeping it at a temperature of 30 C and adding

  10 hour aqueous solution of citric acid to adjust its pH to 3.6. After an additional hour, a 10% aqueous solution of citric acid was added to the reaction mixture to adjust the pH to 3.0, then 20 ml of a 10% aqueous solution of resorcinol are added to the mixture. Microencapsulation is complete after 18 hours of continued stirring. After having collected the microcapsules thus formed, they are washed with water and they are dried in a 35 C air dryer to obtain powder microcapsules of a diameter

average of 30 to 50 micrometers.

  1.4 Preparation of Solvent Activated Type Adhesive Agent as Final Product: In a solution prepared by dissolving 100 parts by weight of Neoprene rubber kneaded in 500 parts by weight of toluene, one part by weight of a phenolic resin and a part by weight of a coumarone resin and, after addition of 30 parts by weight of the microcapsules prepared in (1 3) to the mixture thus prepared, the whole of the

  mixture to obtain the adhesive agent containing the microorganisms

  capsules. Examples 2-9 As in Example 1, except that each of the membrane-forming prepolymers and each of the modifiers shown in Table 1 were used instead of those used in the example.

  ple 1, eight kinds of adhesive agents are obtained according to

the present invention.

  The prepolymers listed in Table 1 are prepared as follows:

Preparation of prepolymers

1.8 g used in Example 4 After adjusting the pH of 146 g of formalin to 8.5 by addition of triethanolamine, this is mixed with 76 g of thiourea and react the

  mixture for one hour at 70 ° C. to obtain a solution

  aqueous solution of the Tu 1.8 F prepolymer (one mol of

  thiourea / 1.8 mol formaldehyde).

  X 2: M Tu 4 F used in Example 7 After adjusting to 9.0 the pH H of 324 g of

  formaldehyde by addition of 2% aqueous solution of

  of sodium, it is mixed with 63 g of melamine and 38 g of thiourea, and the mixture is then reacted with C just after having verified that the melamine

  and thiourea are completely dissolved in the

  In the reaction mixture, 425 g of water are added to the latter, and the resulting liquid is cooled, as it is, to

Room temperature.

  3: M Tu U 5 F used in Example 8 After adjusting to 8.5 the H p of 405 g of

  formol by addition of triethanolamine, this mixture is

  with 42 g of melamine, 25 g of thiourea and 20 g of urea,

TABLE 1

  No Prepolymer of formation Percentage by weight Nature and quantity of mean dimer

  ex-wall of the memasterous material wall with a mnicrocapsule modifier (half

  microcapsules (g) is present in the <dasleu m) crcrètres) microcapsule i M 4 F / U 1.8 F (100/50) 23.8 10, resorcinol 20 to 50 2 M 4 F <200) 23, 7 10, resorcinol 40 30 to 50 3 U 1.8 F <100) 23.9 10 ,, resorcinol 10 30 to 50 4 M 4 F / Tu 1.8 11 <100/50) 24310, resorcinol 120 30 to 50 M 4 F / Tu 1.8 F 15.1 10, resorcinol 200 50 to 70

/ U 1, 8 F (38/18/18)

  6 m 4 F / Tu 1, 8 F / 15.1 1 O, Ix MMéely 30 50 to 70

U 1.8 F (38/18/18)

  mine, 7 Mu I-2 <170) 20.0 10, triethylene 30 to 50 tetramine 8 MTU us (122) 25.0 10, catechol 10 to 30 9 Mt 4 (177) 25.0 10, resorcinol 150 to 30

  Note for Xi, N 2, X 3 and% 4, see the description given below of the respective prepolymers.

  The mixture is then reacted at 70 ° C. for one hour.

  and the product is cooled to room temperature.

  * 4: MU 4 F used in Example 9 After adjusting the pH 324 324 g of formalin by addition of triethanolamine, it is mixed with 63 g of melamine and 30 g of urea, and the mixture is reacted for 30 minutes at 700 ° C. After adding 225 g of water, the mixture is cooled.

  reaction at room temperature.

Test example 1 -

  Each of the adhesive agents prepared respectively in Examples 1 to 9 is painted with a polyvinyl chloride plate 0.5 mm thick at a rate of 6 g of adhesive agent / m 2 of plate and, drying the plate thus brushed for 2 hours at

  400 C, we obtain a non-tacky whitewashed surface.

  Then, another plate is superimposed

  polyvinyl chloride 0.5 mm thick on the surface

  coated with the first plate to obtain a two-layer laminate of polyvinyl chloride with interposition of a layer of the adhesive agent, and the laminate is passed between two press rolls exerting a pressure adjusted to 1 or 20 M Pa (10 or 200

  kg / cm 2) to obtain a bonded body.

  After leaving the glued body to rest in an ordinary room for 24 hours,

  carry out an adhesion test between the two plates.

  The results are shown in Table 2,

  in which, by way of comparison, the results

  test results obtained on glued bodies by means of

  adhesives prepared according to the comparative examples

1 to 5 below.

  Note relating to Table 2, In Table 2, "good adhesion" means that the two plates adhere firmly enough to one of the two 539326

TABLE 2

  Adhesive agent prepared Adhesion between the two plates under a presskin of 1 M Pa <10 kg / cm) 20 MP Ta (200 kg / cm) Exen Vle i good bomie

2 I

n 3 c Il 4 n

"8 '

  the interchangeable eye i Mediocre he He 2 he Mediocre he he 3 the he El 4 S he he 5 him the other so that we can not move by hand one of them compared to the other, and "poor adhesion" means that one of the two plates can be easily separated by hand or that the two plates are not glued to each other.

Comparative Example 1

  By proceeding as in Example 1, except that

  refrain from adding resorcinol as a modifi-

  cation, an adhesive agent containing micro-

capsules.

Comparative Examples S 2-4.

  Using 100 g of the prepolymer M 4 F prepared by proceeding as in Example 1 (1 1) and 50 g of the prepolymer U 1.8 F also prepared as in Example 1 (1 1), but using one of the third constituents indicated in Table 3 and not the water-soluble cationic urea resin and NEOPELE A of Example 1, to thereby obtain a liquid corresponding to the liquid A of Example 1 176 g of xylene are dispersed in the liquid under the same conditions

  than in Example 1 In the case where the p H of the dispersion

  the aqueous solution thus formed falls below 5.0, the liquid corresponding to the liquid A is adjusted to 5.0.

  addition of an aqueous solution of sodium hydroxide.

  The aqueous dispersion is reacted under the same conditions and according to the same procedures as in Example 1, but without adding the 10% aqueous solution of resorcinol, to obtain an aqueous dispersion of microcapsules after collecting the microcapsules.

  and wash them with water, air-dry the micro-

washed capsules.

  Using the microcapsules thus prepared, an adhesive agent containing microcapsules is obtained.

  proceeding as in Example 1.

TABLE 3

  Substance used as a third component in place of soluble cationic urea resin in

water and NEOPELE.

  In the example Substance used as third comparative constituting 2 void 3 SCREEPSE 520 (copolymer of styrene and maleic anhydride, manufactured by Monsanto Co.) in% aqueous solution: 75 g. Reactive surfactant (described in published Japanese Patent Application

46-7313 (1971): 20 g.

Z 539326,

  Comparative Example 5: After having dispersed 176 g of xylene in 275 g of a 10% by weight aqueous solution of 50 C gelatin in the form of particles having an average diameter of 30 to 50 microns, a solution is added with gentle stirring. 10% aqueous gum arabic and 450 ml of water and, after adjusting to 4.4 the pH of the mixture thus formed by addition of a 10% aqueous solution of acetic acid and let the mixture stand for 10 minutes. minutes, the mixture is cooled to 50 ° C. and 36.5 ml of a 25% aqueous solution of aldehyde are added to it.

  glutaric, and the mixture is stirred for one hour.

  After having again brought the mixture to 50 C and

  stirring for 30 minutes, the mixture is cooled to room temperature to obtain a

  suspension of microcapsules By using microcapsules

  Dried pulverulent sules obtained by spray-drying the microcapsule suspension, an adhesive agent containing the microcapsules is prepared

  proceeding as in Example 1.

  When examining the adhesive agents respectively prepared in Comparative Examples 2 to 5, it can be seen that the organic solvent initially encapsulated in the microcapsules completely evaporated.

that no trace remains.

Example 10

  By proceeding as in Example 1, except that 176 g of a 5% solution of triallyl cyanurate in xylene or 176 g of a 5% solution of tertiary butyl perbenzoate in diethyl phthalate are used. instead of 176 g of xylene according to Example 1,

  two kinds of powder microcapsules are prepared.

  Separately, an adhesive agent is prepared by adding 0.5 part by weight of benzyl peroxide and 10 parts by weight of methyl methacrylate in

2539326;

  a solution prepared by dissolving 40 parts by weight

  a tripolymer of ethylene, propylene and 1,4-

  hexadiene in 360 parts by weight of toluene and in

  reacting the mixture for 5 hours at 80 ° C.

  A chemical reaction type adhesive agent is prepared by mixing 100 parts by weight of the thus obtained tripolymer and 6.5 parts by weight of the powdered microcapsules prepared using triallyl cyanurate and 4.0 parts by weight of the powdered microcapsules prepared using the

  tertiary butyl perbenzoate solution

  gouging of the adhesive agent thus prepared two wooden plates of the Philippines, laminating them by superposition of their brushed surfaces and applying to the laminate body a pressure of 1 M Pa (10 kg / cm 2) at 500 C, gets a well-stratified body and

well glued.

  In addition, the adhesive agent thus prepared, containing the two kinds of microcapsules keeps its

  initial adhesive strength after one month of

tion.

Example 11

  By proceeding as in Example 2, except that 224 g of diethyl phthalate containing 5% by weight of benzyl peroxide is used instead of the 176 g of

  xylene according to Example 2, a kind of microorganism is prepared.

  capsule. Separately, a mixed solution is prepared by dissolving 7 parts by weight of methyl methacrylate in a mixed solvent composed of 150 parts by weight of butyl acetate, 120 parts by weight of ethyl acetate and 30 parts by weight. of methyl isobutyl ketone, and by adding to the solution thus formed 40 parts by weight of methacrylate of

  methyl and 1.0 part by weight of N, N-dimethyl-p-

  toluidine. By mixing the mixed solution thus prepared with 6.5 parts by weight of the microcapsules prepared as indicated above, an adhesive agent is obtained.

chemical reaction type -

  After-having sprayed the adhesive agent on

  a mild steel plate and evaporated the solvent, one super-

  installs another mild steel plate on the surface thus coated with the first mild steel plate and, by applying a pressure of 1 M Pa (10 kg / cm 2) to the mild steel plates thus superimposed, is obtained by rupture of the microcapsules a laminated laminate of mild steel plates, which presents after 10 minutes

  strong adhesion between its components.

  Comparative Example 6: Using microencapsulation as in Comparative Example 5, except that 224 g of diethyl phthalate containing 5% by weight of benzyl peroxide was used instead of 176 g of xylene according to the example

  Comparative 5, a kind of microcapsule is obtained.

  After preparing an adhesive agent in a

  6.5 parts by weight of the microcapsules thus prepared

  Using the same mixed solution as in Example 11, the adhesive agent thus prepared is sprayed onto a mild steel plate and the solvent is evaporated. By placing another mild steel plate on the surface thus coated and dried. of the first mild steel plate and applying to the superimposed plates a pressure of 1 M Pa (10 kg / cm 2) as in Example 11, a laminated body is obtained, but the adhesion between the two plates is not Unsatisfactory Adhesion improvement is not obtained in another mild steel plate lamination test, even by application of pressure

  of 20 M Pa (200 kg / cm), using the same adhesive agent.

Example 12

  By proceeding, to prepare the microcapsules, as in Example 6, except that 180 g of a mixture of 100 parts by weight of EPO d 828 (epoxy resin manufactured by the Du Pont de Nemours) and of 10 parts by weight of xylene instead of 176 g of xylene

  according to Example 6, a suspension of

  capsules. After collecting the microcapsules of the suspension, they are washed with water and dried for

  to obtain free-flowing microcapsules

  is lying. By incorporating a solution prepared by dissolving 100 parts by weight of N-methoxy- (methylated nylon), called nylon 8, in 200 parts by weight of

  methanol to 20 parts by weight of the sprayed microcapsules

  rulentes free flowing thus prepared, we get

  an adhesive agent containing microcapsules.

  After having applied the adhesive agent thus prepared on a single wooden plate of the Philippines,

  place on it another wooden plate of the Philippine

  and applying a pressure of 1 M Pa (10-kg / cm 2) at 70 ° C to the body thus laminated, a laminate is obtained.

  of Philippine wood plates with strong adhesion.

  Even after having kept the body thus laminated for one week at a temperature of 700 ° C. and at a relative humidity of 75%, no appreciable degradation of the adhesion between the plates is observed.

glued.

  In addition, the adhesive agent containing microorganisms

  thus prepared capsules keeps in a stable state without

  gelation even for more than a month.

Claims (1)

  An adhesive agent containing microcapsules, characterized in that it comprises:   microcapsules composed essentially of a   at least one of the formation constituents of said adhesive agent and, as a material   forming the membrane of said microcapsules, an amino-   a plastid previously treated with a modifier, and a medium constituted by the other constituents for forming the adhesive agent, said microcapsules being dispersed in said medium and said adhesive agent being of the chemical reaction type or of the solvent-activated type 2 Adhesive agent microcapsule-containing composition according to claim 1, characterized in that said aminoplast is a polycondensate formed from at least one prepolymer selected from the prepolymers of   melamine-formaldehyde, urea-formaldehyde prepolymers   dehyde, melamine-urea-formaldehyde prepolymers   and melamine-thiourea-urea-formaldehyde prepolymers   dehyde or at least one mixed prepolymer containing a melamine-formaldehyde prepolymer and a thiourea-formaldehyde prepolymer, in the presence of a urea resin   soluble cationic agent and anionic surfactant   Picnic. An adhesive agent containing microcapsules according to claim 1, characterized in that said   modifier is a phenolic compound.   An adhesive agent containing microcapsules according to claim 3, characterized in that said   phenolic compound is selected from phenol, resorption   cinol, catechol, hydroquinone, cresol, xylenol and saligenin.   Adhesive agent containing microcapsules according to claim 1, characterized in that said   modifier is a polyalkylenepolyamine.   An adhesive agent containing microcapsules according to claim 5, characterized in that said polyalkylene polyamine is hexamethylenetetramine or triethylenetetramine.   An adhesive agent containing microcapsules according to claim 1, characterized in that the   microcapsules encapsulating a reactive priming agent   and / or a hardener as a core substance, are dispersed in a mixture of the other constituents of the adhesive agent.   An adhesive agent containing microcapsules according to claim 7, characterized in that the reaction initiating agent is dibutyltin dilaurate, stannous caprylate, benzyl peroxide or the like. dibutyl peroxide.   9 Adhesive agent containing microcapsules   according to claim 7, characterized in that the dura-   is N, N-dimethylaniline or N, N-dimethyl-   toluidine. An adhesive agent containing microcapsules, solvent-activated type, according to claim 1, characterized in that the microcapsules encapsulating as a core material a solvent capable of activating the adhesive membrane forming resin, are dispersed in the resin solution intended to form the adhesive membrane.   An adhesive agent containing microcapsules according to claim 10, characterized in that the solvent is selected from benzene, toluene, xylene, hexane, heptane, carbon tetrachloride,   trichlorethylene and tetrachlorethylene.   Process for the preparation of an adhesive agent containing microcapsules, of the chemical reaction type or of the solvent-activated type, characterized in that it comprises: the dispersion of minute liquid particles of at least one of the constituents of the adhesive agent in an aqueous dispersion of aminoplast forming constituents, the addition of an acid catalyst   to the aqueous dispersion, thus causing a polycon-   densification of the prepolymer of said constituents of   aminoplast, the addition of a modifier to the aqueous dispersion during the polycondensation, thereby forming microcapsules encapsulating said   or said constituents in the essential membrane   constituted by said aminoplast modified by said modifier, the collection and drying of the microcapsules thus formed, and   the dispersion of the microcapsules in the other con-   forming agents for the adhesive agent containing microcapsules. Process according to claim 12, characterized in that said aminoplast is a resin obtained by subjecting at least one prepolymer chosen from melamine-formaldehyde prepolymers, urea-formaldehyde prepolymers, prepolymers of   melamine-urea-formaldehyde and the melamine prepolymers   mine-thiourea-urea-formaldehyde, or at least one prepoly-   mixed mother containing a melamine-formaldehyde prepolymer   dehyde and a thiourea-formaldehyde prepolymer at a   polycondensation in the presence of a cationic urea resin   only soluble in water and anionic surfactant.   Process according to claim 12, characterized in that said modifier is a phenolic compound.   Process according to claim 14, characterized   characterized in that said phenolic compound is selected from phenol, resorcinol, catechol, hydroquinone,   cresol, xylenol and saligenin.   Process according to claim 12,   characterized in that said modifier is a poly-   alkylenepolyamine. Process according to claim 16, characterized in that said polyalkylene polyamine is   hexamethylenetetramine or triethylenetetramine.   Process according to claim 12, characterized in that it comprises the addition of 0.1 to% by weight and preferably 0.5 to 20% by weight of said modifier relative to the prepolymer of said   constituents of aminoplast formation.   Method according to claim 18,   characterized in that it comprises adding said modification   an aqueous solution containing it at the rate of 0.02 to 5% by weight.   A process according to claim 12, characterized in that it comprises dispersing the microcapsules encapsulating said reaction initiation agent and / or said hardener in a mixture of the other constituents of the microcapsule-containing adhesive agent.   The method of claim 20, wherein   in that the reaction initiating agent is dibutyltin dilaurate, stannous caprylate,   benzyl peroxide or dibutyl peroxide.   Process according to claim 20,   characterized in that the hardener is N, N-dimethyl   niline or N, N-dimethyltoluidine, Process for the preparation of a solvent-activated type microcapsule-containing adhesive agent according to claim 12, characterized in that   that it includes the dispersion of encapsulated microcapsules   as a core material, an activating solvent   of the resin for forming the adhesive membrane, in the resin solution for forming the adhesive membrane. 2539326,   24 Process for preparing an agent   adhesive containing microcapsules according to the claim   10, characterized in that said solvent for activating the resin is chosen from benzene, toluene, xylene, hexane, heptane, tetrachloride and the like.   carbon, trichlorethylene and tetrachlorethylene.   Process for the preparation of an adhesive agent containing microcapsules according to Claim 12,   characterized in that said acid catalyst is a compound   layer selected from formic acid, acetic acid,   citric acid, hydrochloric acid, nitric acid,   that phosphoric acid, aluminum sulphate, oxy-   titanium chloride, magnesium chloride, ammonium chloride, ammonium nitrate, ammonium sulfate and ammonia acetate.   Process for the preparation of an adhesive agent containing microcapsules according to claim 13, characterized in that said water-soluble cationic urea resin is a resin obtained by subjecting a urea-formaldehyde prepolymer to a polycondensation   with polyalkylenepolyamine, guanidine, diamine,   ethanol, dicyandiamide, diethylaminoethanol or guanylurea. Process according to claim 13, characterized in that said anionic surfactant is a fatty acid salt, a higher alcohol sulfate ester or an alkylaryl sulphonate salt.