DE1594035B2 - Adhesives or sealants that harden when oxygen is excluded - Google Patents

Description

1 2 ^]

The invention relates to the exclusion of oxygen. These esters can be prepared in a known manner

hardening adhesives or sealants based on, for example by esterification of the mentioned

of mixtures of methacrylic acid or acrylic alcohols with the free acids or by conversion

acid esters and organic hydroperoxides. esterification with the methyl esters of methacrylic acid

It is known to use polymeric or acrylic acid in the absence of air. Some of the esters mentioned are

sizing liquid products suitable for adhesive purposes. When using them, it is not

Mix of dimethacrylic acid or diacrylic acid necessary, possibly existing small amounts

to produce esters of dihydric alcohols. Remove stabilizers.

The liquid ester is thereby introduced by introducing in addition to these esters of methacrylic acid or acrylic

Oxygen treated (DBP 953 563) or with hydro- ίο acid can be added to the mixtures in small quantities,

peroxide added (DBP..1 109 891). Furthermore, it is preferably about 2 to 20 ° / ₀ , further polymerizing

known, for the same purpose the monoesters of the bare unsaturated compounds are added.

To convert methacrylic acid from polyhydric alcohols.

contact (French patent specification 1,372,368). The methacrylic acid esters of other monohydric alcohols,

hitherto known 15 hardening in the absence of air, such as the butyl ester or 2-ethylhexyl ester of these

However, mixtures have various disadvantages. Acids. Other poly-

For example, the compounds that can be obtained by treating with oxygen, such as esters, are the

These products do not have a long shelf life. There must be maleic or fumaric acid all the time.

Air or oxygen are introduced in order to further affect the addition of unsaturated prevent spontaneous polymerization. The Ge 20 polyesters often beneficial to the properties of the Mix of diesters of methacrylic acid or acrylic adhesive or sealant or the acid therewith with dihydric alcohols and hydroper- posed compounds.

Oxides are more stable than those previously mentioned. For the production of the adhesives according to the invention

th products, but they result in gluing or sealants, organic hydroper-

only relatively low shear strengths. 25 oxides are used, which differ from such carbon

The monoesters of methacrylic or acrylic acid derive hydrogen, which contains about 3 to 18 carbons polyhydric alcohols allow them to contain hydrogen atoms. For example, tertiary positions are suitable of solid connections between the works - butyl hydroperoxide, cumene hydroperoxide, methyl ethyl substances, however, after mixing with ketone hydroperoxide, they show diisopropylbenzene hydroperoxide. Hydroperoxides often do not have a sufficient storage capacity. The hydroperoxides should be used in an amount of 0.1 Stability and above all result in water sensitivity up to 20%, in particular 0.5 to 10%, based on the borrowed connections. Total mixture, be present.

In addition to the esters of methacrylic acid and acrylic

hardening adhesives or sealants, acid of the optionally substituted cycloaliphatic

starting from methacrylic acid or acrylic acid esters 35 table alcohols and the organic hydroper-

and organic hydroperoxides as well as given oxides can still be used by the hardening mixtures

if they contain small amounts of other polymerizable stabilizers or accelerators. Suitable

unsaturated compounds and common auxiliaries. Nice stabilizers are, for example, hydroquinone,

The adhesives or sealants are thereby di-tert-butyl hydroquinone. Suitable accelerators

characterized in that they are methacrylic acid or 40, for example, aliphatic ^ or aromatic

Acrylic acid esters those of monovalent cycloali- tertiary amines, ζ. B. triethylamine, dimethylaniline,

contain phatic alcohols in which given mercaptans such as octyl mercaptan or dodecyl

if one or two CH ₂ groups of the cycloaliphatic mercaptan and others more. The accelerators

table ring are replaced by oxygen. are generally only used in small amounts of

Mixtures with a content of about 0.1 to 5% are preferably added.

Compounds of the general formula Should the adhesives according to the invention or

Sealant for gluing or sealing

/ ~ - \ glass, plastics or less catalytically

CH ₂ = CR - C - O - (CH ₂ ) B - CH R 'active metals such as zinc, cadmium, high alloyed

■■ · ■ y! ^: '· ^V - ^y 50 steels or anodized aluminum are used,

O so it is useful to use these materials beforehand

accelerating metal salts, e.g. B. copper or cobalt naphthenate to treat. These

where R = CH ₃ or H, η = 1 or O, R '= a treatment can, for example, by spraying the

55 parts of diluted solutions of the salts mentioned, optionally substituted by methyl groups

Remainder of the formula - (CH ₂ ) ₄ - or - (CHa) ₅ ->. On the other hand, it is not recommended to use such

in one or two of the CH ₂ groups through metal salts to the adhesives or sealants

Oxygen can be replaced mean. to be added from the outset, as they

Reduce the methacrylic acid or acrylic acid ester mono- ity very sharply.

valent alcohols are, for example, those of the cyclo- 60 Finally, the adhesive pentanol according to the invention, Methylcyclopentanols, Cyclohexanols and substances or sealants also thickeners, of methylcyclohexanol, methylolcyclopentane, Me plasticizers and dyes are added. as Ethylene cyclohexane, borneol, tetrahydrofurfuryl alcohol thickeners are suitable polymeric compounds or des!, S-Dioxa ^^ - dimethyM-methylolcyclo- fertilize, such as polymethyl methacrylate, polyethylene pentane. The hardening mixtures can also contain acrylate and others, but also inorganic ones various of the aforementioned esters ent-fillers, for example finely divided silica, keep. As a result, for example, a certain calcium silicate, bentonite, calcium carbonate. Titanium wanted Shear strength can be adjusted. dioxide.

3 4

After 3 hours, a shear strength of medium was measured in ^{air or in the presence of 65 kp / cm 2.} 23 hours after the reduction in the amount of oxygen an excellent bond, the value had risen ^{to 115 kgf / cm 3.} Durability on. Compared to known products, the same mixture was produced, but they are characterized by an improved shear strength without triethylamine. If bonds between iron sheets were made with the help of the bond, the end result was. Furthermore, after hardening, the products are firm after a somewhat longer period of time. Less susceptible to the effects of moisture. 60 hours was an average shear strength of

Accordingly, the adhesives or sealants can measure ^{120 kp / cm 2.}

medium advantageous for bonding metals, glass, io With the mixture described first, were

Porcelain and plastics with themselves or degreased aluminum sheets of dimension 23 X

can be used with each other. In addition, 103 mm 2.0 cm ² can be glued overlapping. This was done

very fine cracks or leaks in the mentioned one drop of the mixture between the sheet metal

Materials are closed or sealed. brought and this under a pressure of 0.05 kp / cm ²

The 15 30 hours according to the invention can be combined particularly advantageously. After that time it was

Adhesives, or sealants for bonding, measured a shear strength of 90 kp / cm ^2.
Metals such as iron, steel, anodized aluminum,
Zinc, copper, lead and cadmium are used;

Small amounts of the hardening gel are brought in ρ ie 1 2
mix between the surfaces to be connected, ao

which are placed on top of each other so that the air A mixture of 91 g of the methacrylic

or the oxygen is excluded. According to acid ester of 1,3-dioxa-2,2-dimethyl-4-methylol-

short time, e.g. B. after about ^x / _a to 3 hours, receives cyclopentane, 0.0355 g of hydroquinone, 7 g weight of a 70 ⁰ / _O

you already have a connection between the mentioned commercial cumene hydroperoxide solution and 2 g

Materials which produce their 25 triethylamine after about 4 to 48 hours. She was filled in about 60 ° / ₀

Final strength reached. If necessary, you can keep the SO ccm bottles at room temperature for months

Hardening by heating the joint can be stored without any visible change,

accelerate. As described in Example 1, iron sheets were used

Technical application can be glued together according to the invention. After a storage time of

Adhesives or sealants in accordance with the requirements can be found for 30 3 hours at room temperature

Fixing screws in their threads, different specimens have an average shear strength

for sealing screw connections, measured to a strength of 70 kp / cm ^2. After 20 hours it was

set the average shear strength of plug connections or for sealing to 100 kp / cm ²

of flanges. increased.

Preparation of the starting material: ³⁵

In a distillation apparatus, 803 g of meth- bis ρ ie 1 3
acrylic acid methyl ester, 510 g tetrahydrofurfuryl alcohol

hol, 40 g of hydroquinone and 37.5 g of p-toluenesulfone A mixture of 91 g of methacrylic acid was

acid given. The mixture was on an oil bath 49 ester of cyclohexanol, 0.0055 g hydroquinone, 7 g

Heated (120 to 17O ⁰ C), so that 12 hours of a 70 ° / _o strength commercial cumene hydroperoxide

an azeotropic mixture of methacrylic acid methyl solution in cumene and 2 g of triethylamine produced,

ester and methanol distilled over. Then, about 60 ° / ₀ filled with this mixture 50 ccm

Excess methyl methacrylate was left in the bottle for months at room temperature

Vacuum distilled. The residue could be stored in vacuo without change.

fractionated. There were 680 g of the methacrylic acid with the mixture described were, as in

obtained ester of tetrahydrofurfuryl alcohol (Boiling Example 1 carried out, glued degreased iron sheets.

point 6O ⁰ C at 0.4 Torr n'i 1 4558). After 5 hours, an average shear

The production of the methacrylic acid esters of the cyclo- strength of 35 kp / cm ^{2 was} measured. That value was

hexanols (boiling point 58 ° C. at 1.3 Torr n ' _o ⁵ 1 -4550) 50 increased to 70 kp / cm ² after 20 hours.

and des l, 3-dioxa-2,2-dimethyl-4-methylolcyclopen- were also used with the mixture described

tans (bp 65 ⁰ C at 0.2 torr ⁵ nl 1 · 4438) degreased aluminum sheets of size 20 X

was carried out in an analogous manner. 100 mm 2.0 cm ² overlapping glued and under

. -ι-] a pressure of 0.05 kp / cm ² for 30 hours

B 1 e s 1 e ρ ₅₅ g _e h _a i _th _ j \ f _ac h this time, an average

90 g of the methacrylic acid ester of tetrahydrofuran borrowed shear strength of 60 kp / cm ² measured,
furyl alcohol with 0.0354 g of hydroquinone, 7 g
a 70% commercial cumene hydroperoxide solution and 2.0 g of triethylamine are mixed. The so B is ρ ie 1 4
obtained mixture was about 60 at room temperature
60% full SO ccm bottles can be kept for months. A mixture of 86 g of methacrylic acid was

With the mixture obtained, rust and ester of cyclohexanol, 0.035 g of hydroquinone, 5 g

fat-free iron sheets of dimensions 25 χ 103 mm butyl acrylate, 7 g of a 70 ^D / ₀ igen commercial

2.5 cm ² glued overlapping. For this purpose, the usual cumene hydroperoxide solution and 2 g of triethyl

Place a drop (approx. 0.03 g) of 65 amine at the point to be bonded. In the mixture there was then 0.05 g

given above mixture and dissolved the fluorescein to be bonded.

Metal sheets collide under a pressure of 0.05 kp / cm ² - In the same way as described in Example 1

added. ben, iron sheets were glued together. To

after a storage time of 30 hours at room temperature, an average shear strength of 75 kgf / cm ^{2 was} measured.

B e i s ρ i e 1 5

81 g of methacrylic acid esters of tetrahydrofurfuryl alcohol, which contained 0.005 g of hydroquinone were mixed with 10 g of polymethyl methacrylate (about 100,000 molecular weight), 7 g of a 70 ° / ₀ strength commercial solution of cumene hydroperoxide and 2 g of triethyl 'amine added. An adhesive mixture which could be stored for months at room temperature in _{SO cc bottles filled to 50 ° / 0} and which hardened in a short time in the absence of oxygen was obtained.

Degreased iron sheets were, as described in Example 1, bonded to this mixture and the following shear strengths were observed. After 3 hours 70 kp / cm ² , after 24 hours 130 kp / cm ² .

With the mixture described above, degreased aluminum sheets measuring 20 × 100 mm 2.0 cm ^{2 were} glued in an overlapping manner. The bonds were placed under a pressure of 0.05 kgf / cm ² for 20 hours. Then an average shear strength of 85 kgf / cm ^{2 was} measured.

Example 6

43 g methacrylic acid ester of tetrahydrofurfuryl alcohol, which contained 0.005 g of hydroquinone, with 50 g of a commercially available unsaturated Polyester resin, 5 g of a 70% commercial solution of cumene hydroperoxide and 1 g of triethylamine offset. A mixture which can be stored in the presence of air was obtained.

Rust-free and grease-free iron sheets were bonded to the mixture obtained. After a storage time of 3 days at room temperature, an average tensile shear strength of 180 kp / cm ^{2 was} measured. Comparative experiment

A mixture was prepared from 91 g of the dimethacrylic acid ester of triethylene glycol, 0.0055 g of hydroquinone, 7 g of a 70% commercial solution of cumene hydroperoxide and 2 g of triethylamine. As indicated in Example 1, iron sheets were glued to one another with this mixture. After storage for 30 hours at room temperature, an average shear strength of 40 kgf / cm ^{2 was} measured, which did not increase any further even after prolonged storage.

It was already known to produce latently polymerizable storable masses from the most varied vinyl group-containing monomers, e.g. B. fusel oil acrylate, a polymerization catalyst and a polymerization inhibitor. These mixtures can be stored in the absence of oxygen, however, polymerize spontaneously when exposed to oxygen or air. The composition Such compounds do not allow conclusions to be drawn about hardening in the absence of oxygen Mixtures of acrylic or methacrylic esters.

Claims (2)

Patent claims: 1. Adhesives or sealants that harden when oxygen is excluded, consisting of methacrylic or acrylic acid esters and organic hydroperoxides and optionally small amounts of other polymerizable unsaturated compounds and customary auxiliaries, characterized in that they contain, as methacrylic or acrylic acid esters, those of monovalent cycloaliphatic alcohols, in which optionally one or two CH ₂ groups of the cycloaliphatic ring have been replaced by oxygen. 2. Adhesives or sealants according to claim 1, characterized in that they additionally contain unsaturated polyesters.