JPS6050834B2 - Coating and adhesive resin compositions - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION This invention relates to resin compositions and cured products obtainable therefrom.

British Patent No. 1150203 describes the general formula 1℃H2-
R12-Ar1/1 (dH.

ArOH)nOH (where R' in the formula is an aromatic hydrocarbon group or an aromatic hydrocarbon-oxy-aromatic hydrocarbon group, which may have an inert substituent as appropriate).

Ar is the residue of a phenolic compound as defined below, and n is 0 or 1). British Patent No. 1305551
The patent describes a method of curing the resins with epoxides having two or more epoxy groups per molecule. The above-mentioned resins can be used for the production of surface coatings and laminates with good chemical resistance, high temperature durability, and good electrical properties.

The coating is made of the resin and a suitable hardener such as British Patent No. 1.
Hexamethylenetetramine as described in GB 150,203 or an epoxide as described in GB 1,305,551 is dissolved in an organic solvent such as 2-ethoxyethanol or methyl isobutyl ketone;
This is obtained by applying the resulting solution onto the surface to be coated, evaporating the solvent and then curing the resulting coating to an infusible product.

If the coating has to be used at high temperatures or if special properties are required for the coating, a post-curing treatment, for example at 160-250°C, is also necessary. We have found that the resins described above tend to produce cured surface coatings that exhibit cracking. This 1 burst is a well-known surface coating phenomenon [e.g. 1 Paint, published by Chapman and Hall, written by Manfred Hess]
Paint Film Defec
color) J 2nd edition 1965, page 436] and is related to the fact that the coated surface does not get wet.

Usually resin laminates are made by impregnating glass or carbon fiber or asbestos cloth with a solution of the resin in an organic solvent such as methyl ethyl ketone.

Such laminates have a wide range of uses. Ru. However, for certain applications it may be desirable to incorporate further auxiliary substances into the laminate, such as polytetrafluoroethylene or certain flame retardants, the latter in particular when using epoxy hardeners. There is. However, until now it has not been possible to obtain a completely satisfactory laminate from a resin containing such auxiliary substances. The above resin can also be used as an adhesive, but the adhesive strength of the cured resin is not very strong due to the formation of bubbles during curing. In the coating and adhesive resin compositions containing the resin composition, the resin composition essentially has the general formula (wherein R1 is a divalent or trivalent aromatic hydrocarbon group or a divalent or trivalent aromatic Group hydrocarbons - Oxy aromatic hydrocarbon groups or their derivatives with inert substituents, ArOH is a phenolic compound having 1-3 hydroxyl groups and at least 2 nuclear hydrogen atoms. 0.5 based on the weight of the resin; characterized by containing ~20% by weight of an inorganic dispersant consisting of finely ground silica having dimensions smaller than 15μ in all directions and smaller than 100rnμ in at least one direction and stable up to at least 150°C. The present invention provides a resin composition for coating and adhesive use.

A composition comprising the above resin and finely divided silica with a particle size of 1 to 80rT1μ as a dispersant can be used with a hardener to make a coating solution which is applied and the solvent is evaporated. We have found that heating and curing 1 significantly reduces, if not completely eliminates, the popping problem.

The composition of the present invention containing the above-mentioned resin, dispersant, and curing agent can provide a cured product with few bubbles even if volatile substances are generated during curing with, for example, hexamethylenetetramine, and therefore has high adhesive strength. Can be used as an adhesive.

The amount of inorganic dispersant when using the above composition to obtain an adhesive exhibiting a coating with little splatter or a cured product with few bubbles is usually 0.5 to 20% by weight based on the weight of the resin. , the preferred amount is 1-10% in both cases. In the dispersions of this invention containing a resin and a dispersant (optionally with a curing agent), the amount of dispersant depends on the solvent, the nature and amount of the particulate material, and the degree of dispersion required.

Inorganic dispersants that are stable up to at least 150°C, preferably at least 200°C, have a minimum dimension of less than 15μ in all directions and less than 100n1μ in at least one direction, usually at least 1mμ.

This inorganic dispersant is preferably 3-80rT1μ, especially 7-80rT1μ.
Finely divided silica with an average particle size of 40111 microns, such as colloidal fume silica commercially available under the tradenames AerOtjl and CabOsil. In addition to these silicas, if desired, finely divided warm asbestos, such as that sold under the trade name SylOdex J, having a diameter of about 25 rnμ and a length of 5 to 10μ, is optionally used. (ChrysOtile) asbestos, and finely divided hydrated magnesium aluminum silicates such as bentone (BentOne).
) thickness of 2 to 4 mμ, such as those sold under the trade name
And organic derivatives of montmorillonite having a plate-like structure with a maximum dimension of 0.5 to 1 μm may be added. This resin is preferably an aralkyl ether of the general formula R1(CH2OR)a and/or an aralkyl ether of the general formula R1-+ as described in GB 1150203.
．． CE2 may be contained, and R is 1 to
(2) a molar excess, usually at least 1. 3
:1, preferably by reaction with a molar excess of a phenolic compound or a phenolic compound and an aromatic nucleus-containing non-phenolic compound, preferably in the range from 1.4:1 to 2.5:1. .

If a is 3, n is 1 and one more ArOH
A group may be attached to R1 via a methylene bridge.
In these general formulas, R1 is any divalent or trivalent aromatic hydrocarbon group or aromatic hydrocarbon oxyaromatic hydrocarbon group such as m- or p-phenylene group, diphenylene group, diphnylene oxide group, ' One\, no or base 'and'.

Thus R1 can be mononuclear and fused and non-fused dinuclear and polynuclear groups, but the cured products obtained from R1 mononuclear groups are the same as those obtained from dinuclear and polynuclear groups. R1 has higher strength at high temperatures than
A mononuclear group is preferable. When an aralkyl halide is used to make the resin, it is preferred that R1 is not a diphenylene group or a diphenylene oxide group.
Preferably, the resin is made from an aralkyl ether, especially in the case of resins having alkyl groups of less than 4 carbon atoms, such as methyl groups. Suitable compounds for the reaction with the phenolic compound are those with a valence of 2, especially p-xylylene dihalides such as p-xylylene dichloride and p-xylylene dialkyl ethers such as p-xylylene glycol dimethyl ether.
If desired, the group R1 can contain substituents bonded to the aromatic nucleus, such as methyl groups, which are inert under the reaction conditions.

In fact, it has been found that the presence of chlorine or fluorine atoms at some or all of the substitutable positions of the aromatic nucleus is advantageous because the flame resistance of the resulting polymer product is improved. Examples of substituted aralkyl ethers and aralkyl halides as described above that can be used in accordance with this invention are 2,3,
5,6-tetrachloro-1,4-di(chloromethyl)benzene and 2,3,5,6-tetrachloro-1,4
-di(methoxy-methyl)benzene. Phenolic compounds include any compound or mixture of compounds derived from benzene and containing a hydroxyl group bonded to 1 to 3, preferably 1 to 2, aromatic nuclei; Besides the one essential hydroxyl group, there are a total of no more than three substituents attached to the ring carbon atoms of the benzene nucleus.

Phenolic compounds therefore have the general formula (in the above formula each R3 is hydrogen; hydroxyl group; amino group; alkyl group of 1 to 8 carbon atoms such as methyl, ethyl, isopropyl, tert-butyl or tert-octyl group; phenyl group; Hydroxyphenylalkyl groups, such as hydroxyphenyl-methylene,
-ethylene and -isopropylidene groups). Examples of these phenolic compounds are phenol, p-cresol, m-talesol, resorcin, catechol, 4-methylcatechol, isopropylcatechol, diferolpropane [bis-2,2-(4-hydroxyphenyl)propane], enylolethane, monoalkylphenols such as p-ethylphenol, p-tertiary butylphenol and p-tertiary octylphenol; m- and p-phenylphenol, p-aminophenol, pyrogallol and phloroglucinol. Mixtures of phenols, such as mixtures of monophenols and dihydric phenols (e.g. mixtures of resorcinol and phenol itself) or mixtures of diphenols (e.g. commercially available as 4-methylcatechol and/or phenolic coal tar fractions) Examples of compounds containing aromatic nuclei that can be mixed with phenolic compounds in the production of resins are diphenyl- or dibenzyl-ether, triphenyl, diphenylamine, diphenyl sulfide diphenyl, anthracene, diphenyl sulfone, tri- metal complexes such as phenyl phosphate, octaphenylcyclotetrasiloxane, aryl-substituted borazole and ferrocene.

The proportion of aromatic compounds can vary over a wide range, but in an amount that is not sufficient to prevent satisfactory curing of the reaction product with the curing agent. A more detailed description of the aromatic compounds and the forms used for the reaction of phenols with dihalides or diethers is given in British Patent No. 1,150,203. The compositions of this invention are rendered curable if they contain a curing agent.

Curing agents can be hexamethylenetetramine, quinone, anhydroformaldehyde aniline, chloranil, and ethylenediamine formaldehyde, with hexamethylenetetramine being particularly preferred.
Such hardeners typically contain 5% to 20% based on the weight of the resin.
, preferably in an amount of 8-20% and especially 10-15%. The curing agent may also be an epoxide with two or more epoxy groups per molecule.

The amount of epoxide used depends on the phenolic hydroxyl content of the resin, the epoxy content of the epoxide and the degree of cure desired. Generally, epoxides are used in amounts of 25-150% based on the weight of the resin. The epoxide is mixed with a resin and cured with or without accelerators.
Alternatively, the epoxide and resin are first partially reacted and the partially cured product is then cured by further heating and addition of more epoxide or addition of a cure accelerator. Epoxide is glycidyl ether,
Lycidyl compounds, such as esters or amines, have at least one and preferably at least two epoxy groups, each epoxy group fused to the alicyclic nucleus and other epoxy groups or b) Multiple epoxy groups are acrylic epoxy groups (this is not part of the glycidyl group)
or an acrylic epoxide produced, for example, by epoxidizing an acrylic diolefin.

Examples of glycidyl ethers are the reaction products of epihalohydrin and diphenols such as bisphenols or the reaction products of epihalohydrin and glycerin, i.e. 1,
2,3-tri(1,2-epoxypropoxy)propane, epoxy novolac resin and British Patent No. 11690
It is an epoxy resin as described in No. 45 specification. Examples of glycidyl esters are glycidyl esters formed from aliphatic dibasic acids, preferably alkanedicarboxylic acids, especially those with linear carbon atoms. Examples of glycidyl amines include amino analogs of glycidyl ethers such as 2,2-bis(4
-aminophenyl)propane. When the cycloaliphatic epoxide has one or more cycloaliphatic nuclei, it is preferred to have up to 4 carbon atoms connecting these cycloaliphatic nuclei, but the cycloaliphatic epoxide has no more than 4 carbon atoms between the epoxy groups. It is advantageous to contain only cyclic groups.

Examples of cycloaliphatic epoxides are dicyclopentadiene dioxide, vinylcyclohexene-2-dioxide and the formula (
However, in the formula, R4 is hydrogen or a methyl group) and.

Acrylic epoxides are preferably formed from di- or triolefins of 4 to W carbon atoms, such as 1,2,3,4-diepoxybutene. Curing accelerators advantageously used with epoxides are suitably tertiary amines or salts thereof, such as p-toluenesulfonic acid morpholinium salt, 2,4,6-tris(dimethylaminomethyl)phenol or benzyldimethylamine or Compounds having both a tertiary nitrogen atom and a secondary or tertiary nitrogen atom in the cyclic ring, such as imidazoles such as N-butylimidazole.

Accelerators belonging to the latter category are described in our West German Patent Publication P.
No. 22479l7, while the use of epoxides and other curing accelerators to cure said resins is described in British Patent No. 1305551.

The composition of the invention contains inorganic fillers such as asbestos powder,
Mica or chopped glass strands can also be included.
The ratio of inorganic filler and resin is usually 0.05:1 to 4.0:1
present in a weight ratio of Other ingredients such as pigments, promoters and anti-staining agents, such as magnesium oxide or titanium dioxide, may also be present if desired. Although the compositions of this invention can be prepared by mixing the above ingredients in any order, it is convenient to add the curing agent last.

Mixing can be done by dry kneading to form a powder for molding (optionally an organic solvent may be added later to form the desired liquid for coating or impregnation) or by mixing with a solution in an organic solvent to form a liquid directly. Building can be done in any convenient manner. The solvent is a dialkyl ketone of 3 to 8 carbon atoms, such as methyl isobutyl ketone, methyl ethyl ketone or methyl isoamyl ketone, isofone, diacetone alcohol, 5
Cycloalkyl ketones of ~7 carbon atoms, such as cyclohexanone, alkoxyalkanols containing 1 to 6 carbon atoms in the alkoxy group and 2 to 7 carbon atoms in the alkanol group, such as 2-ethoxyethanol, in the alkyl group The alkyl ethers having 1 to 6 carbon atoms, such as methyl ether, the esters of alkanoic acids having 2 to 6 carbon atoms and said alkoxyalkanols, such as acetic acid esters, and any of these solvents can be used. An aromatic hydrocarbon (in an amount sufficient to keep the resin in solution), preferably a monocyclic one having 6 to 12 carbon atoms such as benzene, toluene or xylene, or white spirit or a solvent. It can be mixed with aliphatic hydrocarbons such as naphtha or alkanols of 1 to 6 carbon atoms such as methanol, ethanol or n-butanol. The resin is 5 to 9 in organic solvent solution.
Preferably 20-65% by weight, for example 20-5% by weight
Usually present in amounts of Mix this at a low temperature, e.g.
It is carried out at 0°C and the resulting mixture is stored until needed.
The remaining ingredients and the cured product are mixed at a higher temperature than usual, for example about 60 DEG C., for several hours, for example 1 to 4 hours, and then the mixture is cooled to room temperature and stored for as long as required. Resin, dispersant (if present), particulate matter (if present)
A liquid dispersion mixture of , solvent and curing agent (and other additives, if present) can be used as the coating fluid.

The solvent may be evaporated from the liquid dispersion mixture and the residual product used as a molding powder. This technique is suitable for producing molded powders containing long fibers that would be broken up by dry kneading methods. The compositions of this invention are cured by heating them usually above 70°C, preferably above 100'C, such as from 150 to 175°C.

If necessary, post-curing is usually carried out at 160°C to 250°C. The time required for post-curing will vary depending on the desired product properties and the temperature at which the product is used. In order to use the compositions of this invention for coating, the resin, dispersant (if present),
The mixture of hardener and solvent (along with other optional additives) can be applied to the surface of the coating by any means, such as by brushing, spraying or dipping.

Usually the surface is of a metal, for example a ferrous metal such as milled steel, but other substrates such as wood, plastic materials or inorganic materials such as porcelain or cement can also be coated if desired. After coating, the solvent is evaporated and the layer is cured. When the dispersant is finely divided silica, the cured layer exhibits little or no repellency. To use the composition of the invention as an adhesive, a mixture of resin, dispersant, curing agent and solvent (along with any other additives that may be added) may be applied by any method such as brushing, spraying or dipping. Applied to one or both surfaces to be bonded together.

Examples of suitable surfaces are metals, for example ferrous, such as milt steel, optionally reinforced with reinforcing agents such as glass fibers or asbestos fibres, for example British Patent No. 115020.
Plastic materials as described in No. 3 or inorganic materials such as porcelain or cement can also be used. After applying the resin composition, the solvent is evaporated, the surfaces of the materials to be bonded are brought together, and the assembly of the surfaces and the intervening layer is cured. Due to the reduced number and/or size of the bubbles produced, the bond produced by this combination has high strength. The invention will now be explained with examples.

Example 1 A composition with the following formulation was prepared.

Composition A (comparative example) 100 resin (softening point 102'C) obtained from parts by weight p-xylylene glycol dimethyl ether and phenol (made by the method described in British Patent No. 1150203) 2-ethoxyethanol
150 hexamethylenetetramine
12.5 Composition B (Example) Carbosil (CabOs
A composition identical to Composition A was made using 2 parts by weight of fuyum silica sold under the trade name il).

Composition C (Comparative Example) A composition similar to Composition A was made using 2 parts by weight of powdered silica having a particle size of about 120 microns.

Composition D (Comparative Example) A composition similar to Composition A was made using 2 parts by weight of finely divided silica with a particle size of about 30 microns.

The above composition was coated on a degreased milled steel plate, dried in one coat at room temperature, and the resulting layer was heated in an oven at 250'C for one coat.
Time cured.

In the case of the layer from composition A, the phenomenon of popping was evident on the cured film on the steel plate, whereas the cured film from composition B did not show any popping. The amount of peeling of the cured resin films from Composition C and Composition D was approximately the same as the amount of peeling of the cured resin film from Composition A.

The degree of peeling of the cured resin film from each of these compositions is shown in Figure 1a (composition A), Figure 1b (composition B),
It is shown in Figure 1C (Composition C) and Figure 1D (Composition D). Example 2 The following solution was made.

a Solution A (comparative example) Solid resin (resin made from industrial grade p-xylylene glycol dimethyl ether and phenol (British Patent No. 1)
(Made as described in No. 150203)
53.5y hexamethylenetetramine 6.5y methyl ethyl ketone
40y solution B (Example) Solution C, which is the same as solution A, except that fumed silica (CabOsil) 5y is added (comparative example) Solution D, which is the same as solution A, except that pulverized silica 5y, having a particle size of about 120 microns, is added (comparative example) ) The same as solution A except that finely powdered silica 5y with a particle size of about 30 microns was added. 1 da sample of each solution was placed in separate aluminum shallow dishes (diameter about 6CrI1), most of the solvent was evaporated at room temperature, and then The samples were cured in an oven at 200°C.

The sample made from solution A was found to have extremely large bubbles, but the sample made from solution B according to the present invention had far fewer bubbles than sample A, and all of the bubbles were much larger in size. It was small. Solution C and Solution D
The bubbles in all of the samples made from the above were large and widely spread. Therefore, these solutions A. When C and D are used as adhesives, the required bonding force of the resin to the surface to be adhered is small and is not satisfactory as an adhesive. The size and number of bubbles in Samples C and D, which use silica with a particle size larger than the particle size specified in this invention, are not the same as in Sample A without added silica, but are still not satisfactory as adhesives. is as described above. These experiments demonstrate that the extremely fine particle size inorganic dispersants defined in this invention have special properties compared to their larger particle size counterparts. Photographs of samples A to D are shown in Figures 2a to 2d (Figure 2a is sample A).
Figure 2b shows the foamed state of sample B, Figure 2c shows the foamed state of sample C, and Figure 2d shows the foamed state of sample D.

Examples 3 and 4 The fuyum silica of Example 2 was replaced by an organic derivative of montmorillonite 5y sold under the trade name 1 Benton 27J and a mixture 5q of warm asbestos and silica (sold under the trade name Silodex 24). The method of Example 2 was repeated.

Results similar to those obtained with solution 2 in Example 7 were obtained. The reduction in the size and number of bubbles upon curing of the resin containing the dispersant indicates the suitability of the resin mixture as an adhesive with good adhesive strength.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1a is a photograph showing the state of bursting of the cured resin film of the resin component of the composition of the present invention when no inorganic dispersant is added, and FIG. 1b is a photograph of the coating resin according to the present invention. Figures 1c and 1d are photographs showing the state of bursting of the cured resin film of the composition, and Figures 1c and 1d show the bursting of the cured resin film of the resin composition containing the inorganic dispersant, which corresponds to Figure 1b with large particle size. FIG. 2a is a photograph showing the state of foaming of the cured resin film of the resin component of the composition of the present invention when no inorganic dispersant is added, and FIG. 2b is a photograph showing the state of foaming. Figures 2c and 2d are photographs showing the foamed state of the cured resin film of the resin composition according to the invention; Figures 2c and 2d show the results of the cured resin film when using an inorganic dispersant corresponding to Figure 2b with large particle size; It is a figure which shows the photograph of a foaming state.

Claims (1)

[Scope of Claims] 1. In a coating and adhesive resin composition containing a resin component and a curing agent for the resin component, the resin composition essentially has the general formula ▲ mathematical formula, chemical formula, table, etc. ▼ (In the formula, R^1 is a divalent or trivalent aromatic hydrocarbon group, a divalent or trivalent aromatic hydrocarbon-oxy-aromatic hydrocarbon group, or a derivative thereof with an inert substituent. ,
ArOH is a residue produced by removing two nuclear hydrogen atoms from a phenolic compound having 1 to 3 hydroxyl groups and at least 2 hydrogen atoms, and n
is 0 or 1), and based on the weight of the resin, from 0.5 to 20
For coatings, characterized in that it contains an inorganic dispersant consisting of finely ground silica having weight percent dimensions in all directions smaller than 15 μm and dimensions in at least one direction smaller than 100 μm and stable up to at least 150° C. Adhesive resin composition.