CS199405B1 - Method of producing modified epoxy resins - Google Patents

Abstract

Epoxy resins are reacted with polyisocyanates. In order to obtain, after crosslinking of the modified epoxy resins, a film having increased elasticity and pronounced flexibility, epoxy resins having a molecular weight of 320-4200 and a hydroxyl number of 0.06-0.45 are reacted with polyisocyanates containing 1.6-28% by weight of NCO and having a viscosity of 6000-95,000 cP, at least 3% by weight of polyisocyanate being employed, based on the epoxy resin. The process is used for the production of coating materials which are easy to apply, the modified epoxy resins obtained being mixed with solvents and/or pigments.

Description

METHOD OF MANUFACTURE OF MODIFIED EPOXY RESINS IN * *

It is an object of the present invention to provide modified epoxy resins capable of forming thin coatings of high elasticity by reacting epoxy resins with polyisocyanates.

The invention also encompasses coating compositions prepared from these modified epoxy resins.

As is known, epoxy resins are chain polymers having reactive terminal epoxy and hydroxy groups bonded to a carbon chain. The number of hydroxy groups present also increases with increasing molecular weight.

As such, epoxy resins are rarely used to form coatings; only the so-called phenoxy resins, i.e. higher molecular weight epoxy resins (approximately 30,000), can be used as the coating agents themselves.

The epoxy resins used in the preparation of paints with or without solvent, or in the preparation of molding resins, are epoxy resins having a molecular weight in the range of 300 to 4000. These low molecular weight epoxy resins are converted into coatings or blocks of desired properties by polyaddition reaction. Thus, the properties of the coatings or blocks depend in part on the molecular weight of the epoxy resin and in part on the nature of the crosslinker used.

199405-2 In the manufacture of cross ^- linked epoxy resins and most commonly used polyamines and polyamides. These reactants react with epoxy groups of the resin. Polyisocyanates are less commonly used as crosslinking agents; which react sh ^yd roxyskupiniani, ^p přremž Oneco ^hook VaJ ^s epoxWové SKU ^pi n ^y unaffected. .

Disadvantage ^p ou ^fo three ^IT EDGINGPROFILE ^{their C} n ^id e ^p o ^lyi sokyanátového type ^P om ^{ters of} short duration and of ^p racovatelnosti cliouloativoat vočté the ^UCI. Vz ^h the ice ^to this last ^e '^ ^é jemnovan indoors ^TX requires t.ato. mite ^or her ^dl and ^uses extended ^p ou ^STE del pigments and completely devoid of water.

When crosslinking is performed using polyamines or polyamides, this reaction system is not sensitive to trace amounts of water. and the pot life is equal to ^E from ^PR acceptable salt thereof. In many ADEC at ^{p H} Vaa ^to the ZIS ^to and very Vrdy ^{t P} o where ^L, which is often purpos ^P ro ^ é purpose ^{y 'p} říliš solid; ^t and ^{the comm} on ice rostro ^{d p} layer the ^e mail ^about diisocyanate tion ^of interference, ^{characterized} in that consists ^of the Ene of ^the ovýc ^HT resins of very ^bt izn ^of Rous ^b. He took ^a disadvantage of these hardness <Jých coatings that refrigerati ^h spring ^from the nos ^T is not for many purposes sufficient po.užití »and .že gave ^{the layer} n ^ate" ru. to ^b Re. Not that ^{the adhesion} to ^the coatings ovýmto only if applied within 24 hours.

There Vpodstat ^{of three.} zplisoby to decrease hardness and increase ^d ost spring ^from the nos in ^{t h} ♦ epoxidovýc ^rubber sk ^y r ^'C (see. for FMDe _^p> Fette, Seifen, Ans ^t r ⁱ e ^l CHM ^ITT. 65. p. 1045 (1963 )), that is

a) straight ^{and both} mixing ^and m plasticizable ^No ova ^d e ^o ^ Prysk ICI. ^{(in some} softening a more ^

b) in ^p-n Ravenite merged with postal ^{Prior to} em ^d in a mol ecu! ^p ox e ^id ovýc ^{hp Kyrie} r ^y s c ⁽ⁱ MV Tm of ^greater than ^{b if} c ⁱ c ^h em ^to soften and

c) the use of crosslinking by forming agents ^{fo, f No} COMES disclaim elastic ^{width p} roducts.

Zm ^EKC-voltage measurement EPOX ^id attribute ^{alkyl p} r ⁱ c ^BC cdstavuje axis ^d to ^{d R} e ^w insoluble Eny probl ^é m because i.nejlepší methods impair the mechanical properties and chemical resistance. .In addition, just a sentence !. Hardly any of the known plasticizers are com ^p at ^Ibil n ^s is ^p ox ^id ew pr ^{y i y} r ⁱ sk CEM ^I (ZT one ^of these zmfcčovadel as ^{di-butyl phthalate),} and ^{i. t} and ^t o změktavadla considerably impair ^the properties ^of the resultant coating. ^P ro ^t j ^of the MV ^for Ramp ^width WTP ^{i n} g ^p ox ^id-voltage pryskyHc ^- does not lead ^{to the} required results obtained by .mu.M (see. Cama, Y.Tanska, Epoxy.Resins Chemietry - and Technology, publisher Marcel Dekker Inc., New York, 1973, p. 305).

B l ^{y y} n ^{currency or} attempts to tenderize e ^p ox ^{e p} ov ^id feature ^to YR ^and CE ctamickými. plasticizers and so on ^{of ex d} after introduction su ^ ^h ^^^ mastnýc ^Ids am not a ^{b l} polyesterii with a APPLICABLE carboxyl groups into the molecules of epoxy resin. However, these attempts have been without ^{oJ via N, E, P F} oněvad after zavedeš aforementioned merged ga ^p U is also a part of the epoxy groups to react, thus further amp zmenšuje'možnost ^it en ^s. _ - '

Of the ^even that ^the AC ^and C ^H - ^ n ^ e ^ Sky ^t and ^s c ^s s ^p ružněj ^{Si pl} astičtějš ^even coating, are "the most common polyamides, dimerized fatty acids (see. WAReise, Metall-Lacke, publishers, WAColomb (Stuttgart, 1965, p. 136). However, for the coatings on metals or for the base paints with fillers, they are not obtained in the past

- 3 199405 with the abovementioned crosslinking agents are not satisfactory in terms of flexibility and sandability. For example, an epoxy resin cross-linked with polyaminoamide cannot successfully be used as a binder for primer primers with filler or for intermediate enamel coatings which are later to be sanded with fine-grained sandpaper because the resulting coating is difficult to grind due to its excessive hardness.

To obtain more flexible coatings, it is also known to use prepolymers containing free isocyanate groups and consisting of hydroxy compounds (for example, hydroxyl-containing polyethers or high molecular weight polyols) and diisocyanates or polyisocyanates as crosslinking agents for epoxy resins. Doyle: The Development and Use of Polyurethane Products, McGraw-Hill Book Company, New York, 1971, pp. 294-297) However, the disadvantage of this method is that it leads to an insoluble and non-fusible crosslinked product.

Another disadvantage of softening crosslinking agents is that they have to be used in large amounts relative to the epoxy resin (see F.M. Depke: Fette, Seifen, Anstrichmittel, 65, pp. 1044-1049 (1963)).

The purpose of the invention is to provide a process for producing an epoxy resin which, when subjected to crosslinking in a manner known per se, provides more flexible and softer coatings than known resins _and which, when more than one layer is applied, allows longer time intervals between application. successive layers.

The invention is based on the discovery that these requirements are fully met by epoxy resins in which part of the hydroxyl groups is reacted with a polyisocyanate of a preselected viscosity and -NCO content.

The invention therefore relates to a process for the production of a modified epoxy resin which produces coatings of higher flexibility after cross-linking by reacting the epoxy resin with a polyisocyanate. The process according to the invention is characterized in that epoxy resins with a molecular weight in the range 320 to 4200 and a hydroxyl number in the range 0.06 to 0.45 are used as epoxy constituents and polyisocyanates with a viscosity in the range 6000 to 95000 are used as polyisocyanate constituents cP and having an -NCO content of 1.6 to 28% by weight, preferably 2.5 to 3.5% by weight, in an amount of at least 3% by weight, preferably 10 to 30% by weight, based on the amount of epoxy resin.

The invention also provides modified epoxy resins prepared by the above process, as well as coating compositions comprising these modified epoxy resins.

The modified epoxy resins produced by the process of the invention may also contain more than 100% by weight of the polyisocyanates, based on the epoxy component by weight, but in such cases the properties characteristic of the epoxy resins become less pronounced in the resulting products.

If they are added to the modified epoxy resins produced by the process according to the invention, they dissolve, and^/or^pigment^y or^-fills, zi^withka^jand^{se n}and mixture^and, which can^být zes^andthe^y acquaintances^-of^pBy the way. How^O,^withgo^ovactheir Siiii^dE^l se vý^hodne pou^žva po^lyami^dŮ fatty acids, γ-lyoins, amiⁿov^ých^aduto not^bo e^tgames^andF^ikovan ^ c^h phenolic^pr^ysk^yřic. Coating^withmě8i^, kt^Ere^- r^ovnIf they contain a crosslinking agent, they can be applied in known manner to the surfaces intended^{é k -} after^toengraving, e.g.^iklad štucem, v^andle^Cpushing, etc. According to^afterin^andhy^afteruži t^Eho s^goovac^ihO^whoseni^dland the deposited coating can^youb^atat room temperature or by heat treatment.

Heads -výhodami mod ^{p if} ikovaných oxidovýc e ^{h y} pr with ^Kyr IC manufactured. way ^of the method of the invention are the following:

and)^- Considering^- to its unchanged^En^Ee^pox^idovým s^toat^Frin^andm mo^hou^bý^{t tyt}o pr ^ s^to^ řice zes^andt^En^y by conventional crosslinking^Cin^idly.

b) After skýtaj ^amp Iten ^and MO ^{difluoro also} hedged EPOX ^{ID oic} r ^y s y ^{s to CE} you ^r oben ^s according to the invention, characterized coatings hitherto-achieved flexibility. These coatings can very advantageously be used as binders for easily sandable primers with fillers and in the middle layer of enamel coatings, and as inner coatings for fats and metal aerosol can containers.

c) Depending on the molecular weight, and the content of reactive isokvanátu ^p olyisokyanátu, Arabic gum reacted with an epoxide ^{to s} ^ c ^i. the hardness of the coating formed from the product obtained can be varied within wide limits.

d) ^p E ^p ovlalky oxide, ^-přip ravenézes ⁱ T ^{e i} n m ^h ovanýc ^fik modified epoxy Prysk ^Yr ic ^{characterized} disburse ^PU manner ^dl after took out e-sectional area, with ^- characterized ^{mares and} pr ^ ⁿ cheese resilient ° STI and ^- in thick layers on the metal surface, and - created by coating, ^kY pfozpůsobujl thermal expansion of the metal substrate without propraskáni.

^e) to ^N-l ášeji ^I modi.f ^{and Forged} epoxy ^d s ^{e p} feature ^to yгi.ce ⁱⁿ ro ^b ^ en ^ ^é ZPI manner in compliance ^p ^ ^ ^P Alez ovrc ^hy - ol in them ^{to IK} vrstvůch savings ^l in the ^IT EDGINGPROFILE ⁱ m ^{i, and} n ^{IDL y} l ⁿ ou individual layers ^{y -} together ^d giant ^{and kd} YZ ^to to ^{be d} al ^{a Si} layer nan ^about the surface of the plurality ^{of n} EŽ ^- 24 ^{di- p} he ny of zatvr ^d nut ^ip R E ^d PGI VRS ^{i- t} v ^y; limit ^and depositing individual layers ^already m e ^- u ^p l ^y Nou ^{to those} not ^{characterized} by ^{lik d} Nu which ^- the ^LAST obzv The advantage ^{n e at both} NAT ^and R ^and n ⁱ in YC ^{o h} subject.

IN^ythe finding is explained in more detail below^d.^Exlad^yto which in^withand^to his roz the reach is not limited.

Example ^1d clay by weight epoxy ^p scored ^NCE about Mole ^to catch a HMO ^t Nost ^and 900 ah ^ydr ° x ^ hunted ^or SLE ^{0, 2,} 5 was melted ^and a melted ^on is heated to ^T e ^pl OTU range ^and 90 to Mp 100 ° C. Where ^P is the tavern steáho waste for instance ^d and ^{30 d} ILU ^- SAFETY HMO ^{t p} ol ^{y alkyl} with an ^and the ^IAK s ^and t oz ^of 80 -000 C, and the content of ^P up ^{to i} n ^-N C0 ^{2, 4} % by weight. ^{N NU} reaction mixture was warmed to ^R.T. EPLO ^{t 1} at 4 ° to ¹⁶⁰ ° C and at ^{t h} e ^t a ^t e ^- plot at ^d ržuje for constant ^h om ⁱ ch ^ck. Preach ACTIVE ^d 3 ⁰ m ⁱ nu ^t em of ^{E and} odetere

- 5 199405 sample which is dissolved in the same quantity of a mixture of 5 ° parts by weight of xylene and 5 ° parts by weight of butanol. The flow time of the resulting solution ^me of manufacture ^A calibrated to ^D a ^b ou No. 4 ^dl after P ^d e re ⁱ are Madars ^Ké standards 9 to 65 ° / 3-73. Once the flow time of the solution reached 8 ° to 9 ° sec. (After about 2 hours of reaction), the reaction being ^'p RERUM cooling ^width and ^d in ^KT. dissolved in a mixture ^of of ⁵ ° ^{parts by} weight of xylene and 5 parts by weight of isobutanol °.

1 °° ^says profiles motnostn ^{h d} c ^{h o} n ^e of results obtained mo ^d i ^f i e ^{s to} crosslinked with ^p ox ^{id e p} o r ^y s ^Kyrie ce ^ se.zes children is 4 to 5 ° parts by weight of polyamide .mastné acid. The coating obtained is. m ^e k ^or not ^f :, ^p ovlak of burned out ^without the N ^s nemo ^difik ovan ^s e ^p ox ^id pryskyri.ce memory. Hardness ^p s u ^l and ^the HE-Voren-oz. mo ^d if ^also hedged. epoxy. ^p r ^y sk ^YR ICE is 38%, ZAT ^s MCO TVR ^d axis ^{t of} the film you ^ Oreneta of unmotivated ox ^id e ^p b ^s prjystyřice ceteris paribus' is. 74% (determined by the Parson method according to 'Hungarian standard 9640 / 4-7!') ·

The ^P and ^K U is the amount ^{of p} circumscribed ^p os ^t u ^p Avşa ^to m ^of n ^e is the ratio ^of RE ^P oxi ^d s ^{e p} r ^y s ^Kyrie CE ^kp ol ^y iso ^-alkyl an ^{at u,} j ^{and k} is Uve ^d eno in the ^b ulcerative I. ^p ou ^lived 's ^and an epoxy ^d r ^{y p y} r ⁱ en ce and polyisocyanates possess the same characteristics as above uvedeno.Hodnota hardness of the resultant coating are reported in table I.

Table I

^FOLDER eni ^p r ^y 8 ^Kyr ice Hardness (zi ^{AI TEN p} arsonic method) nemo if ^also torsionally ^d e ^p ox ^id pr ^ kyHc network. 9 ° ILU strength by weight ^{d s} c ^h e ^p ox ^{e p} p v ^id feature ^{to s} y cn + 10 parts by weight of poly-sokyanátu 80 part by weight ^of an oxide ^ ^p ^ r s'k ^y + ^yR ice over 20 parts by weight isocyanate-7 ° parts by weight of n ^p ox ^e ^ ^id pv ystyfoce ° + 3 parts by weight of poly-isocyanate 74%  56%, 44% 38%

From the data in Table I in mind ^yp lývá ^the hardness of the crosslinked Step ^E ox ^id e ^p ew pr; ce YSK ^yři decreases ^Ys Vol uj ^s c ^s o ^ m ^ u Aho potyísotyan »

Example 2

9 ° K parts of epoxy ^{id e p} o r ^y sk ^YR iceomole ^to hunt ^é weight

38 ° and h ^{y y} phase solvent DROXI ^0, 08 is ^added and ^{the 1} ° part ^of HMO nostníc ^{t h} ^ pol diisocyanate CS ^ ^C ONTENT NCO groups 3.5% ^¹H OA ^{and e Ita} 8 oz 000 ° C ^P . The mixture ^E for m ^{of manufacture,} Chan heated VA at te lo ^{p I s} in the range of ¹¹⁰ ° and ¹² ° C. ^p 30 ^ ch mine the direction ^of the cooling, and ^thereto is ^added 1 ^{parts by} weight hutylgliycid ° ^ EVER Jalka atolv ^- whom you Mdi.dla. Doha outlet ^to u ^ ^. ^'S in the range of 45 ° ^and 5 °° ^to and. ^{(M of} Reno ^{to IB-} al pseudo routing no. 4'podV ^BC E ^dp is ^for Hungary ^'s Norm 9650 / 3-73) ·

20 parts by weight of pigment and 20 parts by weight of filler are dispersed in 60 parts by weight of the above mixture containing the modified epoxy resin and active diluent. 30 parts by weight of aromatic polyamine crosslinking agent are added to the dispersion obtained before use. The resulting coating composition containing no solvent can be advantageously used to create povlalců Eton and ^{b to h} ovovýc ^pl OCH ^and CH PON ^of defects in ^the spring is not ^{a more F} n ^from the coating ^and the mass of the same ^e m ji.nak folded in the ER ^{and kt s} and ^K exceed a ^{b d} i ^f nemo feed is epoxy ^p r ^y sk ^yr ICI. Pru as to the ^{f b d} ou Uve ených. ^{p es} are controlled 4 / mm ^ 0 mm (Erichsen ^Your device specified by ^p le ^d - ^{dp Pla} ISU Madars ^Ké standard no. 9640 / 6-74). . * '''Example of 3 parts. % by weight. polyisocyanate content of NCO groups of 3.5% by weight and a viscosity of 80,000 cP was added to 15 parts by weight of epoxy pryety 'resin ratio of molecular weight of ^l b ^{s 0} · 38 h ^yd rox ^y phase solvent ^whose SLE ^0, 08, and attracting ^and a mixture ^of The mixture was stirred at 100-120 ° C for 30 minutes. The mixture was then cooled and dissolved in a mixture of 10 parts by weight of xylene and 10 parts by weight of ethyl glycol acetate. In this mixture, the extended ^p poll ^{says I} 30 l ⁱⁿ mass Ic ^hp igmentu ² 0 ^says LII ^{of i} ch ^p lniva. Before ^p ou ^{IT s} m ^{to n e} of results obtained suspension ^{was added 7,} 5 ^{d of} clay by weight of an aromatic polyamine crosslinker ·.

· Hmto procedure yielded ^and NAT Rovai ^of HMO and low ^{t h} em contained solvents in ^{TED LE} that is possible ^from NO deposited on surfaces of different ^e · barks' and the thick-.vrstvě. ^K z skanému coating adheres very well another layer even if applied after the expiry of the week.

Example 4.

² 0 l ^{s says} hmotnostníc ^h EPOX ov ^{id e p s} scored CE Mole ^to catch a weight. ⁰ and 380 hydrox ^y m ^s hunting. ^whose sle ^0, 40 are extended in a breath ^{as well as P} 'of the mixture. 7 parts by weight of cyclohexanone, 3. parts by weight of xylene and 11 parts by weight of butyl acetate. To ^the resulting solution was ^{added, with} stirring ^, 1 part of a taotaoste polysocyanate having an -NCO content of 3.5% by weight and an 8000 goat. ^P C and the resulting mixture was stirred for 2 hrs to ^{inferior and when} n ^{s p} te ture between ¹¹ 0 and ¹² ^ 0 ° C. ^The results obtained by him ^{d solution} contained ^h ujícímu mo ^DIFI forged EPOX ^ID verifies the r ^{y p y} r ⁱ sk ^{C is} pfcdá 13 ^says profiles taotnostních ethers of wrought - fenoli.cká prystyfíce in 65% strength by weight. ^/ HMO ^t butanol solution mixture from ^row diluted with 20 parts by weight · ethylglycol, 4 ^DI l ^{s of i} c ^h ethyl ^ o ^ y ^ l ^ 6 ^{parts h} motnos ^T N ^I CH di-cetonalkoholu, 6 parts by weight. 7 parts of butyl acetate and hmotnostních.methylethylketonu, NACE ^F Aji is then ^added 2 parts by weight ^{of a 10% b} utanolov ^eh of the solution ^y n ^{y i} sel ^f orečne fos.

After applying VZN ^also recumbent solution vnikraí povrc ^h tovováho obalovno.ma Erial ^{t (y} on tubes or containers for aerosol ^{y E} mixture) and 15 · enutov ^ ^{t hermalhazards} mz racování ^{when p} _ ^p te lot ^of 180 ° C and 4 m ^ ^p racování utovám out ^{at 260} ° C.

7 199405 obtains an elastic coating resistant to the materials to be filled into the packages. The coating is well tolerated by forming operations (throat formation, sharp bending of tubes below) carried out after application of coatings. In contrast to these coatings, coatings of the same composition, but which contain unmodified epoxy resin, often cracking,

EXAMPLE 5 parts by weight of an epoxy resin having a molecular weight of 1400 and a hydroxyl number of 0.34 are dissolved in a mixture of 24 parts by weight of ethyl glycol acetate and 24 parts by weight of xylene. While stirring, 2.2 parts by weight of a polyisocyanate having an -NCO group content of 22% by weight and a viscosity of 10,000 cP are added to the resulting solution, and the mixture is stirred at 110-120 ° C for 45-60 minutes. During the reaction, the solution flow time measured by the calibrated vessel No. 4 according to the Hungarian standard 9650 / 3-73 is increased from 80 seconds to 180 seconds.

6 parts by weight of polyamine crosslinking agent are added to the modified epoxy resin solution obtained before use. This epoxy resin lacquer forms flexible coatings to which the next layer adheres very well, even if applied after several days.

Claims (3)

Object of the invention A process for producing modified epoxy resins capable of forming thin coatings of high elasticity after crosslinking by reacting an epoxy resin with a polyisocyanate, characterized in that an epoxy resin having a molecular weight of 320 to 4200 and a hydroxyl number of 0 is used as the epoxy component. The polyisocyanate component used is a polysocyanate having a viscosity in the range of 6000 to 95000 cP and an -NCO content in the range of 1.6 to 28% by weight, in an amount of at least 3% by weight, based on the weight of the epoxy resin. 2. Process according to claim 1, characterized in that polyisocyanate 8 is used with an -NCO content in the range from 2.5 to 3.5% by weight. 3. Process according to claim 1 or 2, characterized in that the polyisocyanate is used in an amount of 10 to 30% by weight, based on the weight of epoxy resin.