DE1719145C3 - Polychloroprene adhesive with high heat resistance - Google Patents

Description

Polychloroprene, the reaction product of a p-substituted one Alkylphenol resin with metal oxides, usual additives and volatile organic solvents, characterized in that the alkylphenol resin by reacting 100 parts by weight of one resol-like, p-substituted alkylphenol resin which is free from p-substituted alkylphenoW.ö-dimethylol derivative is, with 2 to 15 parts by weight of cadmium oxide in an aromatic solvent has been made.

The polychloroprene adhesive according to the invention has a remarkable heat resistance without settling. This was modified by mixing a cadmium oxide Resin achieved with the polychloroprene adhesive, the improved reactive AJkylphenolharz had previously been made to react with cadmium oxide.

The cadmium oxide modified reactive alkylphenol resin has been found to support the polychloroprene adhesive film in about 150 hours at room temperature or in 2 to 3 hours at 50 ° C. or in Crosslinked for 30 minutes or less at a temperature of 80 C or more. Accordingly, will the polychloroprene cross-links after bonding, which considerably improves cohesion and at the same time there is an improvement in heat resistance.

The adhesive according to U.S. Patent 2,918,442 is the same as that of the present invention in heat resistance Underlay adhesive containing cadmium oxide modified alkylphenol resin. Since the adhesive film is in Toluene or benzene is completely soluble, no crosslinking has taken place, while the film of the e: r invention The adhesive is no longer soluble in toluene or benzene, but only swells. The networking of the adhesive according to US Pat. No. 291,442 requires a high temperature, and so the Adhesive film before the crosslinking reaction takes place, during the adhesive according to the invention is crosslinked quickly even at low temperature and apparently deshalo excellent heat resistance shows.

The greater the amount of cadmium oxide that can be used, the greater the improvement in heat resistance of the adhesive. However, if too much cadmium oxide is used, the viscosity will increase of the reaction solution during the modification reaction. It was found useful that Modification using 15 parts of cadmium oxide carry out per 100 parts of alkylphenol resin. Preferably an amount of cadmium oxide is used within the range of 2 to 15 parts

used. ". . . .

⁶ B eιs pie1 1

150 g of an improved reactive alkylphenol resin (hereinafter referred to as "R-1" is) prepared by the procedure described below was dissolved in 150 g of toluene, in Divided into 3 parts and filled into reaction vessels with a thermometer and stirring device.

Then cadmium oxide was added to the vessels in an amount of 1.5, 2.5 and 5 g and 0.1 cm ^{3 of} water was then added with vigorous stirring. The reaction was continued with stirring at room temperature. In the beginning there was warming, the brown color of the cadmium oxide disappeared, and the reaction solution in the first vessel turned yellow in about 6 to 7 hours and in the second and third vessel then also yellow. After the reaction solution turned yellow, the reaction was continued in the reached state for additional 30 minutes to complete the modification reaction. After the completion of the reaction, the solvent was removed and the resin produced was dried in a vacuum dryer. Thus, pale yellow, powdery cadmium oxide-modified resins were obtained, which are referred to in the following with "M-3", "M-5" and "M-10", the numbers 3, 5 and 10 indicating the percent by weight of cadmium oxide which is used in the Modification versus RI were used.

100 parts of commercially available polychloroprene, 5 parts of zinc white and 6 parts of magnesium oxide were kneaded and in 90 parts of a mixed solvent consisting of 55 percent by weight n-hexane, 35 percent by weight Acetone and 10 weight percent ethyl acetate, dissolved.

100 parts of cadmium oxide modified resins were in 355 parts of the mixed solvent of these Dissolved composition and then mixed with the previously prepared solution.

The settling of the adhesives thus obtained and the

is heat resistance of the adhesive films with each other compared. The result is given in the table below. That’s also included for comparison Result given with completely unmodified resin R-I.

The resin RI was synthesized in the following manner. 1 mole of p-tert-butylphenol and 2.2 moles of formaldehyde were subjected to an addition reaction in the presence of a barium hydroxide catalyst, and then 0.001 mole of p-toluenesulfonic acid was added. The condensation reaction was conducted for 3 hours at 8O ⁰ C, and the solvent and water were removed by increasing the temperature. It was found by means of thin-layer chromatography that 2,6-dimethylol-4-tert-butylphenol was not significantly involved in the resin RI.

Adhesive based

from M-3

Adhesive based
from M-5.

Adhesive based
from M-10

Adhesive based
by RI

Ab «et? -

appearances

(after 3 months!

no
no
no
no

Heat resistant wedge
Softening point

92-C

156 C

<200 C

68 C

To test the peel strength, two test specimens with dimensions of 2.5 x 15 cm were produced, and the adhesive was applied to one end of the parts measuring 2.5 x 5 cm three times. After drying, the test specimens were bonded under pressure.

The bonded test pieces were stored for 1 week at room temperature, then the test piece was

piece attached to one unglued end and a 500g weight to the other unglued end appropriate. The assembly was placed in a drying cabinet, held at 30 ° C. for 10 minutes, and

5 ⁶

heated further with a temperature gradient of 2 ° C / 5 minutes. The temperature at which the The specimen severed served as a measure of the heat resistance.

Example 2

Cadmium oxide modified resins were synthesized in FIG. 1 mole of p-terL-butylphenol and 2.2 moles

In the same way as in Example 1 using formaldehyde, an additive reaction was carried out in

of the improved reactive alkylphenol resins *, wel- the presence of a barium hydroxide catalyst under-

ches is referred to below with "R-2" and threw and then 0.05 mol of phenol and 0.0005 mol

synthetic p-toluenesulphonic acid added by the method described below The condensation

was produced instead of the resin RI. , o reaction was stirred for 3 hours at 8O ⁰ C

These produced cadmium oxide-modified resins. Then the solvent and water were removed

are then removed with »N-3«, »N-5« and »N-10«

denotes, where the numbers 3, 5 and 10 the Ge of thin layer chromatography found that

Weight percentage of cadmium oxide not found in the £ 6-Dimethylo !! - 4-tert-butylphenol in Resin K-2

Modification was used, compared to the 15 was significantly involved.

Resin R-2 indicates. The adhesives were

Chen manner as in Example 1 prepared

Separated were 100 parts of commercially available polychloroprene, 5 parts of zinc white, 1 part of magnesium oxide and 5 parts of cadmium oxide kneaded and mixed in 390 parts of a mixed solvent with the additive

Composition according to Example 1 dissolved. Made by glue based

Dissolve 100 parts of Resin R-2 in 355 parts of N-3

The solution obtained from the mixed solvent became adhesive based

mixed with the former solution, the adhesive obtained from N-5

substance is denoted by "A-l". Adhesive based

Next was an adhesive in which 1 part of N-IO

Magnesium oxide from A-I based on 1 part cadmium oxide adhesive

was replaced, manufactured, which is designated by "A-2" _from ri

net is. 3 ° »

In addition, an adhesive in which the "

6 parts of cadmium oxide were increased from A-2 to 10 parts, which is labeled "A-3". ^A " ² '■ ··

The settling of the adhesives thus obtained and the heat resistance of the adhesive films became mutually exclusive compared. The results are in fol- A-3

listed in the table.

Resin R-2 was prepared by the following procedure

Withdrawal symptoms (after 3 months I.

none none none

no reddish brown,

flaky excretions

Reddish brown,

flaky excretions

Reddish brown,

flaky excretions

Heat resistance softening point

101 C

162 C

> 200 C

77 C 79 C

92 C 112 C

At s ρ

10 g of Resin R-I were dissolved in 10 g of benzene and 1 g of magnesium oxide (MgO) and 0.1 g of water added while stirring vigorously. After 5 hours unreacted magnesium oxide was removed and benzene was distilled off, whereby a magnesium oxide-modified Resin R-I was obtained. The result of the analysis was the magnesium content of 3.8% certainly. The use of calcium oxide instead of magnesium oxide also resulted in a calcium oxide-modified one Resin R-I obtained. Calcium was determined to be 4.9% as the result of the analysis.

Furthermore, the use of cadmium oxide instead of magnesium oxide resulted in a cadmium oxide-modified one Resin R-I obtained. The result of the analysis was the cadmium content found to be 6.9%.

Separately, a commercially available polychloroprene was gently rolled out and dissolved in benzene to obtain a 10% solution. The various modified resins were added to the polychloroprene solution so that there was a ratio of about 50 parts resin to 100 parts polychloroprene and dissolved therein with good stirring. Films 1 to 2 mm thick were obtained by distilling off the benzene. The films were cut into 1 cm ² pieces after the weight of the films was constant and the solubility in benzene was determined at 30 minute intervals.

The times required for the films to swell in benzene were used to compare the crosslinking reaction levels measured against each other. The result is given in the following table.

Modifying agents

MgO

temperature

20 C

no networking
after 2 months

no networking
after 2 months

~ 150 hours

50 C

no networking

after more than

150 hours

~ 80 hours 2 to 3 hours

80 C

100 hours

7 to 8 hours

less than
0.5 hours

100 C

5 to 6 hours

3 to 4 hours

less than 0.5 hours

Claims (1)

Layer on that a flaky precipitate Claim: contains. ... The separated adhesive can be put back into the Adhesive made from Polychloi apren, the original uniform dispersion product of a p-substituted alkylphenol-5 can be converted by stirring it sufficiently, resin with metal oxides, common additives and the properties of the adhesive are opposite volatile organic solvent, which may not be changed before settling, but is required to be marked that the alkyl- a sufficient stirring of the adhesive before phenolic resin by converting 100% by weight of the application means additional work, share a resol-like, p-substituted alkyl 10 If, on the other hand, the settled adhesive mass phenolic resin free of p-substituted alkyl used without prior agitation change phenol-2,6-dimethylol derivative, with 2 to the composition and viscosity of the adhesive, 15 parts by weight of cadmium oxide in one aro- this can be a reason for poor adhesive properties matic solvent has been produced. be. 15 The separation can be traced back to that a coagulation of the added fillers and accelerated precipitation of the coagulated filler Polychloroprene adhesives will take place on the fabrics. Such behavior is dependent used in a wide variety of areas. However, although the resin used, the process brought about Layer of non-vulcanized poly- 20 position of the adhesive, the type of polychloroprene adhesive used at ordinary temperature chloroprene, the composition of the solvent due to the crystallization of the polychloroprene, etc. Among these factors is the one used When the molecule shows strong cohesion, resin decreases most importantly. The cohesion above the primary conversion is to prevent this phase separation point because of the disintegration of the crystals considerably as in the case of neo- and becomes insufficient. To remedy this, prene - solvent - phenol formaldehyde resin - S> a reactive alkylphenol resin added. The reaction is known ("Adhäsion", 10, (1966). S 296 bis tive alkylphenol resin is a condensate of one-off 299), polar organic compounds with low tigern phenol, which is substituted with an alkyl group. Molecular weight from tertiary butylphenol resins is tuiert, the at least 4 carbon atoms in the 30 by chain extension or fractionation-para division and has two active positions. the ones to reac- divide. tion are suitable, and formaldehyde. According to the USA patent 2918442, a com- sat has a methylol group in the ortho position bination of alkali metal hydroxide or alkaline earth end phenol nucleus and is an aggregate of various metal oxide or hydroxide, e.g. B. Ca (OH) ₂ , MgO. These types of molecules in which the corresponding BaO and SrO and a phenol-formaldehyde resin bond the corresponding phenol nuclei to one another by means of dimethyl cohesion of the polychloroprene adhesive film, ether bond or methylene bond. The crosslinking of the polychloroprene adhesive are. Such a condensate reacts with a metal with the metal oxide-modified phenol formaldehyde in an aromatic solvent and forms hydharz, according to US Pat. No. 2918442, requires a metal-modified resin with the chelate bond. 40 a high reaction temperature and a long time. Thus, such reactive alkylphenol resins are not commonplace to increase heat resistance. on a crosslinking of the polychloroprene, but on The reactive resol type alkylphenol resin reacts to the fact that the metal reacts with metal oxide such as e.g. B. Magnesium oxide, which is mixed into the oxide-modified phenol-formaldehyde resin a high-polychloroprene adhesive at the same time 45 ren melting point than the unmodified phenol, whereby a non-meltable magnesium-formaldehyde resin has or no longer melts,
oxide-modified resin is formed. In recent times, the demand for polychloro- Fusible magnesium oxide-modified resin verpren adhesive with a particularly high thermal conductivity the adhesive layer of the polychloroprene adhesive resistance. It has already been suggested a Substance containing resol type reactive alkylphenol resin 50 appropriately selecting the type and amount of metal, To meet a large cohesion at room temperature oxyds as a filler and in particular as well as at elevated temperature. Apart from the other cadmium oxide to be used. Indeed it rises Modification reaction based on the addition of the reactive heat resistance of polychloroprene adhesives Resole type alkylphenol resin to polychloroprene fabric considerably by replacing part or the Adhesive and the implementation of the modification 55 total magnesium oxide, which is used as a filler Reaction with magnesium oxide in which the adhesive is added, due to cadmium oxide. However is based on the composition, a different method was proposed to reduce the tendency for the adhesive to settle with cad, which on the implementation of the miumoxide after the manufacture very large and the Reaction of the reactive resol type alkylphenol resin adhesive therefore useless. Such a settling with magnesium oxide before preparing the adhesive 60 can also not be prevented if you do that Substance and then adding the resulting improved reactive alkylphenolic resin, the Product as a modified resin based on the adhesive. prevents settling if magnesia than Both methods are used. Filler is added. The addition of cadmium The adhesives obtained in this way show an identical oxide alone can only improve the heat resistance of the moderate but opaque dispersion phase adhesive to a certain extent, but lead directly after manufacture, and over time many problems in practical use separate the dispersion phase into one transparent or undissolved dung,
translucent topsheet and a detached article of the invention is made up of an adhesive