DE1594035A1 - Adhesives or sealants that harden in the absence of oxygen - Google Patents

Description

Henkel & Cie

Patent department Düsseldorf-IIolthausen, the l'l. 12 _r l9ßü

Henkelstrasse $ 7 _% Dr SchOe / N. 1594035

New patent application

D 3172
"Yes! Oxygen-free hardening adhesives or sealants."

The invention relates to adhesives which harden when oxygen is excluded or sealants based on mixtures of methacrylic ,? acidic or acrylic acid esters and organic hydroperoxides.

It is known to produce liquid mixtures of dimethacrylic acid or diacrylic acid esters of dihydric alcohols which polymerize in the absence of air and are suitable for adhesives. The liquid ester is treated by introducing oxygen (DDP 953 563) or hydroperoxide is added (DAS 1 109 891). It is also known to use the monoesters of methacrylic acid of polyhydric alcohols for the same purpose (French patent 1,372,368). However, the mixtures known to date which harden with the exclusion of air have various disadvantages. The products obtained by treating with oxygen have a poor shelf life. Air or oxygen must be constantly introduced to prevent impure spontaneous polymerization. The mixtures of diesters of methacrylic acid or acrylic acid with dihydric alcohols and hydroperoxides are more stable than the products mentioned above, but they only give relatively low shear strengths when bonded.

BATH ORIGINAL

909834/1312 - 2 -

Henkel & Cie GmbH

Patent department.

D 3172 - 2 -

The Ilonoester of Ilethacryl- or acrylic acid with polyvalent Alcohols allow the production of solid compounds between the materials, but after mixing with hydroperoxides they often have insufficient storage stability and mainly result in compounds that are sensitive to water.

The invention is based on the problem of those with exclusion of oxygen to find hardening, storable adhesives or sealants which do not show the above disadvantages.

This object is achieved according to the invention by mixtures of methacrylic acid esters or acrylic acid esters]! and organic hydroperoxides, which are characterized by a content of acrylic or methacrylic acid esters of cycloaliphatic alcohols, in which one or two CH ₂ groups of the cycloaliphatic ring can optionally be replaced by oxygen.

Mixtures containing compounds of the general formula are preferred:

CH ₀ = CR - C f- 0 - (CIL ·) - QH- R ^f 0.

where R = CIU or H, η = 1 or 0, R ¹ = a radical of the formula - (CH ₂ ) j _} - or - (CII ₂ ), -, in which one or two of the CH ₂ groups can be replaced by oxygen, mean.

BATH ORIGINAL

90883 * / 1312 ^ _

Henkel & Cie GmbH

The compounds to be used according to the invention are methacrylic acid or acrylic acid esters of monovalent alcohols, for example of cyclopentanol, methylcyclopentanol, cyclohexanol and methylcyclohexanol, methylolcyclopentane, Methylolcyclohexane, borneol, tetrahydrofurfuryl alcohol or des l ^ -Dioxa-S ^ -dimethyl - ^ - methylolcyclopentane. The hardening mixtures may also contain various of the aforementioned esters. This can, for example, a certain desired Shear strength can be adjusted.

The esters to be used according to the invention can be prepared in a known manner, for example by esterifying the mentioned alcohols with the free acids or by transesterification: with the methyl esters of methacrylic acid or acrylic acid. the Some of the esters mentioned are commercial products. When using them it is not necessary to remove any small amounts of stabilizers that may be present.

love the present invention to be used esters of methacrylic acid or acrylic acid can also mixtures in a small amount, preferably about 2 to 20% _t more polymerizable unsaturated compounds may be added. As such, eligible acrylic or methacrylic come about other monovalent alcohols, such as butyl or 2-Äthylhexy! Esters of these acids. Other polymerizable compounds, such as esters of maleic or fumaric acid, can also be used.

909834/1312

RAP

Furthermore, the addition of unsaturated polyesters often has an effect beneficial to the properties of the adhesive or sealant b / .v ;. the connections made with it from ..

To prepare the "-Öönifsche invention, organic hydroperoxides may be _{employed, -?} 'W ^ ß & ieh- derived from such hydrocarbons containing from about, 3 to 18 carbon atoms For example, suitable tert, butyl hydroperoxide, cumene hydroperoxide, Methyläthylketorihydro- · peroxide. Dilsopropylbenzolhydroperoxid * the hydroperoxides' U $ V ■ are in an amount of 0.1 to 20% \ ,: in particular 0.5 to 10%, relate to the total mixture, can be present.

In addition to the polymerizable esters of methacrylic acid and acrylic acid of the optionally substituted cycloaliphatiRChrn alcohols The hardening mixtures can be the organic hydropooxides still contain stabilizers or accelerators. Suitable stabilizers are, for example, hydroquinone, di-tert-buty ^ hydroquinone.

Suitable accelerators are, for example, aliphatic or aromatic tertiary amines, for example triethylamine, dimethylaniline, hercaptans such as octyl mercaptan or dodecyl mercaptan and others. The accelerators are generally only added in small amounts of about 0.1 to 5 % .

- 5 909834/1312

. 1534Ö35

If the products according to the invention are to be used for gluing or sealing glass, plastics or catalytically less active metals such as zinc, cadmium, high-alloy chairs or anodized aluminum, it is advisable to use these materials beforehand with accelerating Mc potassium salts , e.g. copper or cobalt naphthenate. This treatment can take place, for example, by spraying the parts with dilute solutions of the salts mentioned. On the other hand, it is not advisable to add such metal salts to the mixtures in accordance with the invention from the outset, since they greatly reduce the shelf life of the mixtures.

Finally, thickeners, Plasticizers and dyes are added. Polymeric compounds are suitable as thickeners, v / io et v / a polymethyl methacrylate, polyethyl acrylate and others.

Furthermore, can be zugeHefczt, for example feinvert rushed silica Calciumsllikat, bentonite, calcium carbonate, titanium dioxide the erflndungsgemäß to be used as a thickener mixtures' inorganic fillers. .

The solutions according to the invention show in air or in the presence excellent durability from small amounts of oxygen. They stand out from well-known products through improved shear strength of the with their help

9 098 34/1312

produced bonds. Furthermore, after hardening, the products are less susceptible to the effects of moisture.

Accordingly, the mixtures can be advantageous for bonding metals, Glass, porcelain and plastics with themselves or with one another be used. In addition, the finest cracks or leaks can occur in the materials mentioned with the inventive Mixtures are closed or sealed.

The adhesives according to the invention can be particularly advantageous and sealants are used for joining metals such as iron, steel, anodized aluminum, zinc, copper, lead and cadmium will. Small amounts of the hardening mixtures are brought in between the surfaces to be connected, which are placed on top of one another in such a way that the air or oxygen is excluded. To a short time, e.g. after about 1/2 to 3 hours, a connection between the mentioned materials is obtained, which after reaches its final strength about 4 to 48 hours. Possibly the curing can be accelerated by heating the joint. ι

The adhesives according to the invention can be used for technical purposes

You will find sealants for fixing screws in your garage.

threads, for sealing screw connections, for fixing of plug connections or for sealing flanges.

909834/1312 ■■

Production of the Ausreangsmaterials;

800 g of methyl methacrylate are placed in a distillation apparatus, 510 g tetrahydrofurfuryl alcohol, 40 g hydroquinone and 37.5, <r, given p-toluenesulfonic acid. The mongrel was on the oil bath (120-170 ° C) heated so that an azeotropic mixture of methyl methaerylate and methanol distilled over for 12 hours Excess methyl methacrylate was then distilled in vacuo. The residue was fractionated in vacuo, ^ s were 6P <0 g of the methacrylic acid ester of tetrahydrofurfuryl alcohol obtained (boiling point 60 ° C at 0.4 Torr njpl. 4558).

The preparation of the methacrylic acid esters of cyclohexanol (boiling point 58 ° C at 1.3 Torr η ² ^ jl <. 4560) and 1,3-Dioxa-2,2-dinethyl-4-methylolcyclopentane (boiling point 65 ° C at 0.2 Torr

2'j
η ~ ■ 1. 443 ") was carried out in an analogous manner.

1:

'JO g of the methacrylic acid ester of tetrahydrofurfuric alcohol were mixed with 0.005% hydroquinone, 7 g of a 70 # strength commercially available cumene hydroperoxide solution and 2.0 g of triethylamine. The mixture obtained in this way could be kept for months at room temperature in SO ccm bottles filled to 60%.

• The mixture obtained is made from rust-free and grease-free iron sheets the dimensions 25 x 100 mm glued overlapping 2.5 cm.

909834/1312 "AD O", Q, NA _L

- «ft -

To do this, a drop (about 0.08 g) was placed on the area to be glued. the above mixture and the sheets to be bonded under

• · 2

joined together at a pressure of 0.05 kgf / cm.

! After 3 hours, a shear strength of 65 kp / cm was measured,

20 hours after bonding, the value had risen to 115 kgf / cm.

2a the same mixture was made, but without triethylamine. If bonds between iron sheets were made with it, the final strength will be reached after a somewhat longer period of time. Do

An average shear strength of 120 kgf / cm was obtained for 2 b0 hours measured.

The mixture described first was degreased aluminum

Sheets measuring 20 χ 100 mm are glued with an overlap of 2.0 cm.

To do this, a drop of the mixture is placed between the sheets

and put them together under a pressure of 0.05 kp / cm for 30 hours.

joined. After this time, a shear strength of 90 kgf / cm

enjoyed.
Example 2:

A mixture of 91 g of the methacrylic acid ester of 1,3-dioxa-2,2-dimethyl- ⁱ {-methylolcyclopentane, 0.0055 g of hydroquinone, 7 g of a 70% commercial cumene hydroperoxide solution and 2 g of triethylamine was prepared. It was 60 % full

909834/1312 BAD OWQINAL

- Q -

^ O ccm bottles at room temperature for months without any visible Change storable.

As described in Example 1, iron sheets were glued together. After a storage time of 3 hours at room temperature

became an average rope-maker at the various rehearsals
strength of 70 kp / cm measured. After 20 hours, the

average shear strength 'increased to 100 kgf / cm.

Example 3:

A mixture of 91 g of methacrylic acid ester of cyclohexanol, 0.0056 g of hydroquinone, 7 g of a 70% commercial cumene hydroperoxide solution in cumene and 2 g of triethylamine was prepared. SO ccm bottles filled to 60 % with this mixture could be stored for months at room temperature without any changes.

With the mixture described, 'as in Example 1', degreased iron sheets "glued. After 5 hours

measured an average shear strength of 35 kgf / cm.

2 'This value had risen to 70 kgf / cm after 20 hours.

Furthermore, with the mixture described, degreased aluminum

Sheets measuring 20 χ 100 mm are glued with an overlap of 2.0 cm

and held under a pressure of 0.05 kp / cra for 30 hours. After this time, an average shear strength became

measured from 60 kp / cm,

- 10 - 9 0 9 834/1312 n>r> original

- ■ ίο -

DeJGpiel * < ;

A mixture of 86 g of methacrylic acid ester of cyclohexanol, 0.005 g of hydroquinone, 5 g of butyl acrylate, 7 g of a 70% commercially available cumene hydroperoxide solution and 2 g of triethylamine was prepared. 0.05 g of fluorescein was then dissolved in the mixture.

In the same way as described in Example 1, iron sheets were glued together. After a storage time of 30 hours at room temperature, an average

Measured shear strength of 75 kgf / cm.

Example 5: · \ "■

Rl g of the methacrylic acid ester of tetrahydrofurfuryl alcohol, which contained 0.005 g of hydroquinone, were mixed with 10 g of poly methyl methacrylate (molecular weight about 100,000), 7 g of a 70% commercial solution of cumene hydroperoxide and 2 g of triethylamine. An adhesive mixture which could be stored for months at room temperature in 50 % full SO ccm bottles was obtained, which hardened in a short period of time in the absence of oxygen.

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, after 2k hours 130 kp / cm

909834/1312

BATH ORIGINAL

With the mixture described above were defatted

2 aluminum sheets measuring 20 χ 100 mm, overlapping 2.0 cm

glued. The bonds were under pressure for 20 hours

set of 0.05 kgf / cm. Then became an average

Measured shear strength of 85 kgf / cm.

- 12 -

909834/1312 ^BAD ORIGINAL

Henkel & Cie GmbH

D 3172 - 12 -

Comparison ν request

A mixture was prepared from 91 g of the dimethacrylic. r.MurcGsters of triethylene glycol, 0.0055 g of hydroquinone, 7 g of a 70 # igen 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 ¹ IO kp / cm was measured, which does not continue to rise even on prolonged storage.

- 13 -

BATH 909834/1312

Claims (1)

Henkel & Cie GmbH Patent department D 3172 - 13 - Claims Adhesives or sealants that harden when oxygen is excluded based on mixtures of methacrylic acid or acrylic acid esters and organic hydroperoxides, characterized by a content of acrylic acid or methacrylic acid esters of cycloaliphatic Alcohols in which one or two clip groups of the cycloaliphatic ring are optionally activated by oxygen sets can be. 2) adhesives or sealants according to claim!, Characterized by a content of compounds of the general formula CH _n s CR - C - 0 - (CH ₀ ) - CH R ¹ d. η cn V _n ^ ^ / 0
where R = CH, or H, η = 1 or 0, Ft ¹ = a radical of the formula - (CH ₂ ) H- ^or - (CH ₀ ), - which is optionally substituted by methyl groups. in which one or two of the CH _O groups can be replaced by oxygen. 3) adhesives or sealants according to claim 1, characterized by a content of acrylic acid or methacrylic acid esters of borneol. ^) Adhesives or sealants according to claim 1 and 2, characterized by a content of acrylic acid or methacrylic acid esters of cyclohexanol or methyl! cyclohexanol. -IU- BATH ORIGINAL 909834/1312 5) adhesives and sealants according to claim 1 and 2, characterized by a content of acrylic acid or methacrylic acid esters of cyclopentanol or methylcyclopentanol. 6) adhesives and sealants according to claim 1 and 2, characterized by a content of acrylic acid or methacrylic acid esters of methylolcyclohexane or methylolcyclopentane. 7) adhesives and sealants according to claim 1 and 2, characterized by a content of acrylic acid or methacrylic acid esters of tetrahydrofurfuryl alcohol. 3) Adhesives and sealants according to claim 1 and 2, characterized by a content of acrylic acid or methacrylic acid ester! des 1,3-dioxa-2,2-dimethyl- ⁱ l-methylolcyclopentane 3. 9) adhesives and sealants according to claim 1 to 8, characterized by an additional content of other polymerizable unsaturated compounds ble in small amounts, preferably from about 2 to 20 %. . 10) Adhesives and sealants according to claim 1 to 9 »characterized by an additional content of unsaturated polyesters. '■ HENKEL & CIE. GmbH. i.A. ppa. (Dr. Arno ^ dy) (Dr. Haas) 909834/1312 SAD ORIGINAL