DE2343806C3 - Process for the production of an elastomer composition and use of the same as an adhesive or coating agent - Google Patents

Description

Artificial or naturally occurring solutions Elastometers in volatile organic solvents and known such solutions can be found in a variety of ways Use, especially as a sticker Coating agents, for example in the shoe industry. The adhesive masses should be heat-resistant and quickly develop an optimal bond strength. To improve the bond strength of elastomeric adhesive compositions, organic triisocyanates have already been added to them, e.g. B. 4,4 ', 4'-triphenylmethane triisocyanate. This results in a high bond strength in the course of 1 to 2 days trained.

From the German Offenlegungsschrift 1 719 265 elastomers are known which can be cured with the aid of polyisocyanate. It is also known that polyisocyanates are often trimerized to a small extent.

However, triisocyanates are very reactive, and this means that the "pot-life" of adhesives is based on greatly reduced by elastomers.

The object of the invention is to provide a method for producing an elastomer compound which have a well controllable pot-life and which harden quickly.

The invention relates to a method for producing an elastomer mass under homogeneous Mixing of (A) artificial elastomer and (B) organic polyisocyanate, which is characterized is that a 15 to 150% trimerized Toluylene diisocyanate (B) with a chloroprene polymer or mixed polymer (A) and a catalyst, capable of trimerizing (B) is mixed.

A solution of (A) in an organic, easily evaporable solvent is preferably used J5 used in the manufacture of the elastomer compounds. (B) is also preferably in an organic solvent, expediently in the same Canaättel solution like (A) above. (B) is preferably in a concentration of 30 to 60% in the solution,

based on the solids content.

Suitable solvents are aliphatic hydrocarbons, like hexane; aromatic hydrocarbons such as toluene or xylene; Halogenated hydrocarbons, such as fluorocarbon compounds, trichloro

ethylene, methylene chloride or 1,1,1-trichloroethane; Ketones, for example methyl ethyl ketone and methyl isobutyl ketone and esters, for example butyl acetate or ethyl acetate.

In such cases where the elastomer masses should not be used for adhesive or coating purposes, but for example as a closure or Sealing compounds or as putty do not need to contain any solvents in the elastomer compounds being.

Tolylene diisocyanate is present as a single product or as a mixture with tolylene-2,6-diisocyanate.

Partial trimerization of (B) can be achieved by known substances in the presence of a variety of Catalysts, like the one in Saunders and Frisch, »Polyurethanes, Chemistry and Technology«, Part I, Interscience Publishers, 1962, pp. 94 to 97. The tetramethylguanidine provides a preferred catalyst for partial trimerization because it has catalytic activity

Add a small excess of benzoyl chloride Can be completely eliminated when the partial trimerization has reached the desired extent.

The degree of trimerization in percent corresponds to the following equation:

Degree of trimerization. %

= 100

(Initial polyisocyanate,% NCO, partially trimerized polyisocyanate,% NCO) η

Initial polyisocyanate. % NCO

(B) should be trimerized to 15 to 150%. Preferably the degree of trimerization is 100 to 140%.

In the process according to the invention, (B) is used in amounts such that 1.0 to 10, and preferably 1.5 to 5.0 percent by weight of free NCO groups, based on the weight of (A), before * are in hand.

In the case of polychloroprene, one works to advantage; 65 1.5 to 4.0 percent by weight (B), expressed as NCO.

The catalyst according to the invention can be any compatible trimerization catalyst, i.e. one Catalyst capable of trimerizing an organic isocyanate such as phenyl isocyanate. Trimerization catalysts are in large Diversity known (see Saunders and Frisch, loc. cit.), including aliphatic tertiary amines, basic salts and soluble organometallic compounds. If desired, catalyst mixtures can also be used. Aliphatic tertiary amines are preferred

The amount of sin catalyst in the process according to the invention is generally 0.01 to 200Ge-

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"Maybe percent, based on the NCO content of the 'spolyisoeyanats and jst dependent wm, the Trimeiäsationsgrad and the desired speed gartim ^. In the ESaU of the T & lyfi & otoprensKund ^ ies trimerized toluene düsocjaBajs fiänrnerjisationsjriad 120 to 130%) and:

None

nols represent 25 to 100 percent by weight cat based on the weight of the trimerized Isocyanate provided NCO gnip, a good one Area. '·,.-.....

In the production of the elastomer compositions according to the invention, the usual additives, such as Antioxidants, anti-ozone agents, etc. are also used, ....,> ■

The elastomeric compositions obtainable according to the invention have a processability - pot life - of at least 20 minutes up to 8 hours or longer.

example 1

Various compositions of the following recipe were prepared by mixing on a grinder (whereby parts and percentages relate to weight):

Chloroprene polymer 100 parts Butylated p-phenylphenol

(Antioxidant) 2 parts

oil soluble terpene phenol resin,

M.p. 133 to 152 ° C specific Weight 1.09 25 parts Chlorinated rubber (64 to

65% chlorine, viscosity of

20% solution in toluene

17 to 25 cP) 15 parts

Magnesium oxide 4 parts Zinc oxide 5 parts Amine catalyst *) Toluene hexane methyl ethyl

ketone (1: 1: 1) 453 parts

*) Calculated in such a way that calculated for every 2 parts of polyisocyanate as NCO. I part is not applicable.

The compositions were prior to use with 3.5% of a 40% solution of a crude PoIyisocyanats (consisting of an n ^directly; was stripped CHT refined primary-toluene diamine phosgenation of the solvent and contained the 34% NCO and a Trimerization degree of 19% had) mixed in methylene chloride. The resulting mixtures were applied in the form of thin films each have two strips of a shoe sole material based on natural rubber and butadiene-styrene copolymer and 30 minutes allowed to dry, then 1 minute at 80 ⁰ C untei infrared radiation reactivated and then 15 seconds at 4 kg / cm ² compressed (for results see the following table). To determine the bond strength (kg / cm), the strips were pulled apart at 70 ° C. at a speed of 5 cm / min, two determinations being made, one after 30 minutes of aging of the bond IAi at room temperature and the other after corresponding aging for 24 hours. The gel time (hours) indicates the length of time that the product can still be spread and4- (Dimethylaminomethy]) - phenols

Qi20

0.32

Gel formation

7 6 6 25

TriSthylenediamine .. N-ethyimorpholine

Ν, Ν, Ν ', Ν'-tetnimethylguanidine

Example 2

The following experiment explains the improvement in early hot bond strength that results from increasing the amount of trimer in the isocyanate portion of a two-part polychloroprene isocyanate adhesive gives:

A) Production of mixed polychloroprene putty (part A)

Mill Mix: The chloroprene polymer was prepared by mixing the ingredients for 10 to 15 minutes mixed on a rubber grinder at 50 ° C according to the following recipe:

Chloroprene polynes 100 parts Magnesia 4 parts Zinc oxide 5 parts Butylated p-phenylphenol 2 parts

Adhesive:

Mill mix 111 parts

Terpene-Phenolic Resin (as used in Example 1) 25 parts

Chlorinated rubber (as used in Example 1) 15 parts

2,4,6-tri- (dimethylaminomethyl) phenol 1.15 parts

Toluene-hexane methyl ethyl ketone (1: 1: 1) 453 parts

B) Preparation of isocyanate solutions (Part B)

The monomer used in the present example was made from a mixture of 2,4- and 2,6-toluene diisocyanate prepared in a ratio of 80:20 and as a solid with a molecular weight isolated from 56OgZMoI. In making everyone Isocyanate solutions were made by dissolving solid trimer and 2,4-toluene dusocyanate in methylene

chloride formed a solution containing 6.0 or 12.0 g NCO groups / 100 g of solution contained.

C) Preparation and testing of lift-off test samples

For every adhesive compound tested, there was sufficient isocyanate solution (Part B) to add 2.9% NCO, based on polychloroprene, d. H. Obtain 0.48 g of NCO for 100 g of Part A, mixed with Part A for 30 minutes.

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Gen brushed onto the smooth shoe sole material described in Example 1 at intervals of 5 minutes. After 30 minutes Trod * penlassen the adhesive on the UnteriageoberfBche were samples for dep, Lifting Test made by the adhesive-coated substrates reafctiviert wiucne-and 25 seconds later, 10 seconds _ago? 3.9 kg / cm ² zxh were compressed. The samples witrden predetermined times at ambient temperatures and then aged at an angle of 1801 ° at 70 ⁰ C and a crosshead speed of 5.1 cm / min, pulled apart.

Toluene diisocyanate Commitment
180 ° lift-off at 70 ° C kg / cm after 24 hours Trimeres after 30 meows bd ambient at ambient temperature (Weight percent) temperature 0.71 0 0.13 11.10 10 0.21 30th 0.36 1.66 80 0.79 1.66 100 0.95

An equivalent mass of the prior art with thiophosphoric acid & iris ^ p-isocyanate phepyl ester) in methylene chloride instead of the trimerized one; Isocyanate without a catalyst gave strength values of 038 and 0.96 kg / cm after 30 minutes and 24 hours, respectively.

Example 3

The trimer was produced here by trimerization of 2,4-ToluoldSsocyanat with Tetramethylguaaidin at 60 ⁰ C to a Tnmerisalionsgrad of 126%. The isocyanate obtained was mixed with ethyl acetate to a solids content of 50%. This stock solution had a Brookfield viscosity of 110 cP at 26 ° C. and an isocyanate content of 9.6%.

A) Preparation of isocyanate solution (part B)

20 g of the above-described isocyanate stock solution were mixed with 30 g of methylene chloride and a solution containing 3.85 g of NCO / 100 g Part 3 included

The production of Part A ₁ the lift-off test samples and the test method corresponded to Example 2.

20th

Neoliie-Neolite lift-off resistance

Weight amount of NCO per 100 g of part A

0.21 0.27 0.48 *)

180 ^o - AbhebefaitigVeit up to 7O ⁰ C, kg / cm

after 30 minutes at ambient temperature

0.36 0.54 0.21

after 24 hours at ambient temperature

0.86 1.13 0.73 Brookfield viscosity des mixed putty, cP

3 hours after mixing

2280
3640
4200
5520

24 hours after mixing

3960 4700 5360

*) The isocyanate solution in this state-of-the-art control experiment was thiophosphoric acid-tris-ip-isocyanatophenyl ester)

Example 4

Similar to example 1, an elastomer compound was produced according to the following recipe:

Grinding mix Chloroprene polymer 100 parts Butylated o-phenylphenol

(Antioxidant) 2 parts

Magnesium oxide. 4 pieces Zinc oxide 5 parts Dissolution on the kneader Above, ground mass 111 parts Terpene phenol resin (as in Example 1 used) 25 parts Chlorinated rubber (as in Example 1 used). 15 parts Toluene-hexane-methylethyl-

ketone (1: 1: 1) 453 parts

catalyst

(Dispersed 24 hours before isocyanate addition)

Triethylamine 0.4 parts

Isocyanate / 4.8 parts by weight to 100 parts by weight of the total mass, namely a primary diamond Phosgenation product with a degree of trimerization of 125% and a solids content of 50% in ethyl acetate.

Adhesion test: phenolic resin / plywood - shear strength test bonds with evenly applied adhesive layer on each surface: open for 20 minutes - pressing at 2.8 kg / cm ^{2 for} 10 seconds; Determination at 21 ° C; expressed in mean values in kg / cm ² .

storage

7 days at 21 ° C

28 days at 21 ° C

7 days at 21 ° C and then 7 days in

Water + 1 day at 21 ° C

28 days in water + 1 day at 21 ° C .. 7 days in oxygen at 21 at + 1 day

at room temperature

28 days in oxygen at 21 at + 1 day

at room temperature

7 days at 93% relative humidity

+ 1 day at room temperature

28 days at 93% relative humidity

+ 1 day at room temperature

strength

43.9 53.1

18.8 16.7

32.3 36.8 31.5 24.8

Claims (2)

: ι ^Γ \ ι ν t Patent claims: L procedure; for the production of an elastomer compound with homogeneous mixing of (A) artificial elastomer and (B) organic polyisocyanate, characterized in that a 15 to 150% trimerized Tokrjlene diisocyanate (B) only the chloroprene polymer or -nTischpolymeieo ^ A) and a catalyst that £ 8} capable of iramerisjeiien, is mixed. 2. Use of the elastomer composition according to claim 1 as an adhesive or coating agent