CS231018B1 - Sealants with increased exposure to wood, ceramics and metals - Google Patents

Abstract

It has been found that based on the substrate, the highest adhesion values to the substrate are found. unsaturated polyester resin when the acid number and the hydroxyl number are virtually identical in the binder. This can be achieved by the addition of copolymerizable acid and / or by means of mono- and diesters of phosphoric acid and / or copolymers of acrylic or methacrylic acid with vinyl monomers.

Description

The invention relates to sealants with increased adhesion to wood, ceramics and metals based on unsaturated polyester resins. It has been found that unsaturated polyester binders in sealants have the highest adhesion values to the substrate which, after curing, have practically the same acid value and hydroxyl value, which is achieved by the addition of a copolymerizable acid, or acidic acid esters, or mono. and diesters of phosphoric acid and / or copolymers of acrylic or methacrylic acid with vinyl monomers

Unsaturated polyester resin cements are commonly used. They are mainly used for leveling substrates such as wood panels or steel products.

After curing, they are machined. Abrasives include limestone, chalk, wood flour, kaolin or other additives as fillers (E.W. Laue Gummi Asbest Kunst. 14,

532, 1961). On the other hand, the bottoms with increased abrasion resistance have feldspar, corundum or finely ground metal as filler. The treatment of fillers with an aqueous suspension of dibenzgyiperoxide is also known (H. H. Kussner: Plaste Kaut. 7, 431, 1960). Resins based on glycols or polyglycols, phthalic anhydride and maleic anhydride are sensitive to alkalinity, which is particularly evident for application in the environment and for increased water circulation. It is known, for example, in the field of glass laminates that alkaline glasses significantly reduce the mechanical properties of laminates.

A similar phenomenon applies to sealants that contain fillers reacting with free carboxyl groups, ie sealants filled with limestone, chalk or glass meal. To suppress the reactivity of the fillers, their surface treatment is carried out, for example with fatty acids, silicone resins and the like. Similar phenomena can be observed even when filling with some metal powders. The disadvantage of these processes is a relatively complicated treatment of fillers and, moreover, a reduced adhesion of the treated sealants to the substrates.

These disadvantages are overcome by the present invention. The sealants according to the invention have high adhesion values to wood, ceramics and metals, in particular aluminum alloys. The values of shear, peel and perpendicular tear strengths reach the values of epoxy sealants. They are 10 to 50% higher than the known types of polyester sealants.

In the present invention, 100 parts of an unsaturated polyester resin or a mixture of unsaturated polyester resins are used as binders, at least one of which is in the form of a solution of unsaturated polyester in styrene with a styrene content of 28 to 38% by weight. These resins have an acid number of from 20 to 50 mg KOH / g and a hydroxyl value of from 39 to 70 mg of KOH / g, the difference between the hydroxyl number and the acid number being at most 35 mg KOH / g. It has been found that unsaturated polyester binders have the highest values of adhesion to substrates, which, after curing, have practically identical values of acid number and hydroxyl number in cements. This can be achieved by the addition of acids or acid esters such as acrylic acid, methacrylic acid, an acidic maleic or fumaric acid ester having an alkyl length of 1 to 2 and / or 6 to 8 carbon atoms. It is also possible to use mono- and diesters of phosphoric acid having a number of carbon atoms in the alkyl of 12 to 18, optionally with an alkyl containing 1 to 5 ethoxy groups. Copolymers of acrylic or methacrylic acid, in particular styrene having an acid number of 10 to 100 mg KOH / g and a molecular weight of up to 5 000, can also be used. with a softening point of 48-60 ° C. The sealant also contains a maximum of 20 parts of an aromatic and / or aromatic-aliphetic solvent or a phenolic or quinone type polymerization inhibitor, in addition to 50 to 400 parts of inorganic and / or organic pigments and fillers. In particular, accelerators based on cobalt, vanadium, manganese and / or aromatic amine are added at most 0.5 parts. When glass flour or calcium carbonate filler is used in the putty; preferably, a phosphoric acid partial ester is used to adjust the difference between the hydroxyl and acid numbers. If acrylic acid or methacrylic acid is added to the binder, a maximum of 4 parts by weight based on the binder is added. Preferably, the donkey may contain a magnetic ferrite as a pigment with an iron or steel powder filler content.

The binder used in the present invention is an unsaturated polyester resin or a mixture thereof, at least one of which is in the form of a solution of unsaturated polyester in styrene having a styrene content of 28 to 38% by weight. Unsaturated polyesters are prepared by polycondensation of saturated and unsaturated dicarbosyl acids or derivatives thereof with alkylene glycols and / or polyalkylene glycols, respectively. by polycondensation of functional and substitution derivatives of these starting compounds. The unsaturated polyesters may still be modified with monofunctional alcohols and / or acids.

Appropriate adjustment of the ratio of the hydroxyl and acid numbers of the binder prior to the addition of the accelerator or initiator can be accomplished by the addition of copolymerizable acids and / or acid esters already in the binder solution, optionally bound by chemosorption or adsorption to pigments and fillers. Acrylic, methecrylic acid or acidic maleic or fumaric esters having a carbon number in the alkyl group of the ester of 1 to 2 and / or 6 to 6, such as, for example, fumaric or maleic acid monomethyl ester, monoethyl ester of the acid, can be used as the polymerizable acids of the invention. fumaric or maleic acid, fumaric or maleic acid monohexyl ether, fumaric or maleic acid mono- (2-ethylhexyl) ester and / or mono- or diesters of phosphoric acid having a carbon number in the alkyl group of 12 to 18, optionally with an alkyl containing 1 to 5 ethoxy groups.

As such, the following may be used: monoester or diester of phosphoric acid and 1-tridecanol or 7-tridecanol, mono- or diester of phosphoric acid and myrisalcohol, mono- or diester of phosphoric acid and 1-pentadecanol, mono- or diester of phosphoric acid and 1-heptadecanol; a mono- or diester of phosphoric acid and ethylcellosolv and a mono- or diester of phosphoric acid and diethylene glycol monoethyl ether and pentaethylene glycol monoethyl ether. It is also possible to use copolymers of acrylic and / or methacrylic acid with vinyl monomers, in particular styrene having an acid number of 10 to 100 mg KOH / g and a molecular weight of up to 5 000, which at the same time function as flow agents.

The consistency and reactivity of the sealant can be adjusted with up to 35 parts of the reactive, polymerizable monomer. These are vinyl-type monomers such as styrene and its derivatives wooltoluene, divinylbenzene, α-methylstyrene, halostyrenes, esters, (meth) acrylic acid (methyl methacrylate) and vinyl esters (vinyl acetate, vinyl propionate)]. Among the allyl compounds, diallylorthophthalate and diallyl isophthalate are particularly suitable.

Not more than 1 part paraffinic additive may be added to the sealant. The paraffins are selected so that their softening point is 48-60 ° C.

Aromatic and / or aromatic-aliphatic compounds are selected as solvents in a maximum of 20 parts. These are especially benzene, toluene, xylene, ethylbenzene. isopropylbenzene, and esters, in particular dibutyl phthalate, dibutyl, or dioctyl ester of maleic or fumaric acid. A polymerization inhibitor may be added to the composition, either alone or in the form of a solution, in the above solvents. Either phenolic-type compounds such as hydroquinone, pyrocatechin, resorein, phenol and / or derivatives thereof and quinone-type compounds such as benzoquinone, 1,2- and 1,4-naphthoquinone, anthraquinone and / or derivatives thereof are used as inhibitors.

The sealant further comprises 50 to 400 parts of inorganic and / or organic pigments and fillers.

Particularly suitable fillers are slate meal, ground calcium carbonate or limestone, kaolin, kaolinite, bentonite, chalk, talc, calcium sulfate, magnesium and zinc, magnesium carbonate, feldspar, carborundum powder, colloidal silica, glass powder, asbestos powder, metal powders such as iron, steel, brass, aluminum. Among the organic fillers, in particular, powdered polyethylene, polyvinyl chloride or wood flour are used.

The unsaturated polyester cements are cured in a known manner, by a redox system, i.e. by the addition of an accelerator, in particular based on cobalt naphthenate or cobalt octtoate, or by the addition of vanadium or manganese compounds to the corresponding peroxide. Of the organic peroxides:

peroxides based on ketone peroxide and dibenzoyl peroxide. When using dibenzoyl peroxide, it is suitable to use aromatic amine accelerators such as dimethylaniline or dimethyltoluidine, optionally in combination and cobalt octtoate. Such formulated sealants have increased reactivity, especially with ketone peroxides. The surface of the sealant that is in contact with the air remains weakly adhesive due to the inhibition of the strength of the polyester binder by air oxygen. By adding waxy substances, especially paraffins with a softening point of 43-60 ° C, this effect is eliminated because the paraffin is deposited on the surface of the composition and thus prevents the ingress of oxygen. The content of fillers and their type in the sealant significantly reduces the proportion of paraffins exiting the surface, and therefore the content of paraffins and waxy substances usually increases several times compared to the composition without fillers. However, waxy substances, and in particular paraffins, also have a significant effect in reducing the adhesion of the substrate. The invention is further illustrated by exemplary embodiments wherein percentages and parts are by weight unless otherwise indicated.

Example

Sanding compound of the following composition:

(a) 80 parts of a 6656 solution of unsaturated polyester based on phthalic anhydride, maleic anhydride and ethylene glycol in styrene, with an acid number of 28 mg KOH / g and a hydroxyl number of 45 mg KOH / g

b) 18.6 parts of a 7056 unsaturated polyester solution on qdipic maleic anhydride and diethylene glycol in styrene, the acid number being 50 mg KOH / g and the hydroxyl number 35 mg KOH / g

c) 1.4 parts acrylic acid

d) 15 parts styrene

(e) 80 parts of slate meal (a mastic of the same characteristics is obtained by using the same quantity of kaolin or talc)

(f) 60 parts of silica

g) 0.5 parts of dioctyl fumarate

h.) 1.5 parts of a 256 solution of cobaltoctoate in toluene; and 0.15 parts of dimethylaniline

The difference in acidity and hydroxyl value in the binder after treatment with acrylic acid is zero. Itael is curable with ketone peroxides or dibenzoyl peroxide and upon curing it provides the following mechanical properties:

Shear strength at durret 9.02 MPa

Peel strength on duralumin 0.29 N / mm

Example 2

Floor leveling compound:

(a) 97,7 parts of a 6556 unsaturated polyester solution, based on phthalic anhydride, maleic anhydride and ethylene glycol in styrene, with an acid number of 25,5 mg KOH / g and a hydroxyl SiO10 of 40,5 mg KOH / g

c) 28 parts styrene

(d) 70 parts micronised limestone

(e) 70 parts feldspar

f) 30 parts of polyvinyl chloride powder

(g) 5 parts reddish iron oxide

The difference between the acid number and the hydroxyl number in the binder is zero after treatment with methacrylic acid. The tear strength of wood putty is 1.9 MPa.

Example 3

Putty for metal castings with the following composition:

(a) 96,4 parts of a 65% solution of unsaturated polyester, based on phthalic anhydride, maleic anhydride, adipic acid, propylene glycol and ethylene glycol in styrene, with an acid number of 25,0 mg KOH / g and a hydroxyl number of 34,0 mg KOH / g

b) 3.6 parts of an acid fumaric acid ester of 2-ethylhexanol

c) 10 parts styrene

(d) 20 parts corundum (a sealant of the same characteristics is obtained when steel powder in the same quantity is used instead of corundum)

(e) 75 parts feldspar

f) 5 parts of tannin-treated iron powder

(g) 2 parts silicon dioxide

h) 2 parts of ferrite - magnetic iron oxide.

The difference between the acid number and the hydroxyl number in the binder after treatment with the acid ester of fumaric acid is zero. The sealant has the following mechanical properties:

shear strength on duralumin 10.0 MPa peel strength on duralumin 0.44 H / mm adhesion to wood perpendicular tear 1.6 MPa

Example 4

Sealant resistant to abrasion.

(a) 95,2 parts of a 65,1% solution of unsaturated polyester, based on maleic, phthalic and ethylene glycol in styrene, with an acid number of 22,8 mg KOH / g and a hydroxyl number of 42,2 mg KOH / g

b) 4.8 parts of dilauryl orthophosphoric acid ester

o.) 10.0 parts of styrene

231Ó18

d) 20.0 parts of polyvinyl chloride powder

e) 40.0 parts of micronized feldspar

f) 40.0 parts of carborundum powder

(g) 20,0 parts of ground powdered glass

h) 0.2 parts paraffin, softening point 52/54 ° C

The difference in acidity and hydroxyl value in the binder after treatment with diethyl orthophosphoric acid ester is 10 mg KOH / g. After curing, my peel strength from duralumin was 0.48 N / mm.

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Example 5

The abrasion resistant mastic of Example 4, wherein instead of 10 parts styrene, 15 parts methyl methacrylate. As a polymerization inhibitor, 10 parts of a 0.0 .mu.l solution of 2-methoxyphenol in toluene are used. The difference between the acid value and the hydroxyl value in the binder after treatment with diethyl orthophosphorous diethyl ester is 10 mg KOH / g. After curing, my sealant has a peel strength of duralumin 0.46 N / mm.

Claims (4)

). Mastic with increased adhesion to wood, ceramics and metals based on unsaturated polyester resins, containing fillers, pigments and additives, cured with accelerators and peroxide initiators, characterized in that it contains 100 parts by weight of unsaturated polyester resin or mixtures of unsaturated polyester resins, of which at least one is in the form of a solution of unsaturated polyester in styrene with a styrene content of 28 to 38% by weight and an acid number of 20 to 50 mg, a KOH / g and a feydroxyl number of 35 to 70 mg KOH / g. 35 mg KOH / g obtained by the addition of acids or acid esters such as acrylic acid, methacrylic acid, acid esters of maleic or fumaric acid having an alkyl length of 1 and 2 and / or 6 to 8 carbon atoms such as further mono and diesters of the acid phosphorus with a number of carbon atoms and alkyl of 12 to 18, optionally ethoxylated with one to five ethoxy groups, such as copolymers of acrylic or methacrylic acid with vinyl monomers, in particular styrene having an acid number of 10 to 100 mg KOH / g and a molecular weight of up to 5,000, up to 35 parts reactive polymerization capable monomer vinyl or acrylic or allylic type, not more than 1 part of a paraffinic type additive with a softening point of 48 to 60 ° G, not more than 20 parts of an aromatic and / or aromatic-aliphatic solvent or phenolic or quinone type polymerization inhibitor, 50 to 400 parts of inorganic and / or organic pigments and fillers, up to 0.5 parts of accelerator, in particular based on cobalt, vanadium, manganese and / or aromatic amine. 2. The sealant according to claim 1, wherein the content of acrylic or methacrylic acid in the binder is at most 4 parts by weight based on the binder. 3. The mastic according to claim 1, characterized in that the calcium carbonate-based partial flour or filler is preferably contained in a phosphoric acid partial ester. 4. The sealant according to claim 1, characterized in that it preferably comprises a magnetic ferrite as pigment during the circulation of the iron or steel powder filler.