JPS63175063A - Adhesive mixture - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION In many cases, the gluing of rubber shoe soles with polyurethane adhesives results in unsatisfactory adhesion values without special pretreatment. Therefore, many proposals have been made to improve adhesion. For example, according to British Patent No. 1,500,296, the tread surface of a shoe sole is coated with a solution of an N-halogen compound (so-called primer) before applying the adhesive. Shoe soles pretreated in this way are characterized by excellent adhesion values when using polyurethane (PU) adhesives. The disadvantage is that one further step is required before the gluing operation. It is also known that N-halogen compounds may be reacted with adhesives or mixtures thereof may be used as primers (GB 1,293,842).

However, the drawbacks mentioned above apply here as well.

GB 2.048,897 describes another primer in the form of a reaction product of an N-halogen compound and a 5BS-block polymer (rsBs"). In this case too, the freshly prepared primer solution still contains N~halogen compounds, and in addition there is still a need for one more operating step. There is therefore still a need for adhesives suitable for bonding thermoplastic rubber soles, in particular of the SBS type or similar products, without the need to use a primer. Due to their non-polar construction, these sole materials cannot exhibit adequate adhesion to PU adhesives. A) Polyurethane 20-99, preferably 60-95
, especially 70 to 90 parts by weight, B) Aromatic vinyl compound/diene block polymer 5
0, preferably 0.5 to 30, in particular 5 to 20 parts by weight, C) modified aromatic vinyl compound/diene polymer 0
．． 5-50, in particular 5-30 parts by weight, and D) 0-10 parts by weight of polyisocyanate, suitable as adhesives.

As adhesives, these mixtures are present in a solvent. In the absence of a primer, they bond SBS block polymers (eg as sole materials) to each other and to other polymers with excellent initial and final adhesion values.

Mixtures of polyurethane adhesives and styrene/butadiene block polymers alone do not produce useful bonds. A freshly prepared mixture of polyurethane adhesive and styrene/butadiene block polymer, for example in methyl ethyl ketone, initially appears homogeneous and cloudy;
After a few hours two phases begin to appear, the volume of each depending on the mixing ratio between the components.

In contrast, polyurethane (PU) and partially modified S
It has been found that a mixture of BS in solvent remains a clear solution for several months, but produces unsatisfactory adhesion values. If the modified SBS is unstable P as mentioned above,
When added to a binary mixture of U and SBS, a surprisingly cloudy but permanently stable mixture is obtained. Clouding is caused by very small, uniformly distributed particles that have no tendency to settle. Such ternary mixtures remain stable for several months and meet the need for non-settling adhesives that yield high adhesion values. The same results were obtained with highly modified SBS (i.e. A
and C), wherein component C is used at least 1.5 moles of modifier, preferably from 1.8 to 2.3 moles per mole of butadiene units.

Component (A) according to the invention consists, for example, of a substantially linear, soluble or meltable polyurethane with terminal hydroxyl groups. The use of such materials for bonding various substrates is known. Their manufacture is described, for example, in German Patent Nos. 1°256.822 and 1,930.
, 336 or 2,161.340. The polyurethanes in question can be synthesized from crystalline dihydroxy polyesters having a molecular weight of 800 to 4000 using chain extenders and diisocyanates. Polyester polyurethane whose polyester component is a mixture of various alcohols (German Patent Application No. 3, 5)
No. 02.379) are likewise suitable. Such polyurethanes exhibit advantageous thermal activation behavior. All details of the polyester components and their proportions, diol components and diisocyanate components can be found in the above-mentioned patents referenced herein. However, the composition of component (A) in the present mixture is not limited to the polyurethane described above. Alternatively, it is also possible to use reaction products with polyisocyanates containing polyether diols or polyether ester diols. Similar polyurethanes in which the polyester component is polycarbonate or in which polycarbonate groups are present in addition to carboxylic ester groups can also be used. It is also possible to use polyesters whose acid component is a mixture of various carboxylic acids. In addition to polyesters based on C, diols, it is also possible to use polyesters based on C2 and/or C, diols or mixtures thereof with C, diols.

German Patent No. 1.256.822, No. 1,930.3
The process products of No. 36 and No. 2,161.430 and of German Patent Application No. 3,502,379 are preferred.

Polyurethane A is generally 0.1 to 4, preferably 0.2
It has a viscosity (15% by weight in methyl ethyl ketone) of ~2 Pa-5 (Brookfield viscometer, spindle 3.60 rpm, 23°C).

The block polymer (B) comprises at least one block of polymerized aromatic vinyl compounds, such as, for example, styrene, vinyltoluene, alpha-methylstyrene, vinylnaphthalene, and if present also a small amount of, for example, divinylbenzene. It also contains divinyl compounds. Styrene and α-methylstyrene are preferred, with styrene being particularly preferred. These 7-mer polymers form so-called hard blocks (as opposed to styrene).
).

The diene block is preferably a polymerized diene such as 04-ca1.3- such as 1,3-butadiene, isoprene, 2,3-dimethyl-1,3-butadiene
Contains diene. Butadiene and isoprene are preferred, with butadiene being particularly preferred. Therefore, the diene block is also referred to as "B" (as opposed to butadiene). The diene block is a so-called soft block.

Block polymer B has an average density of 4 to 500 per molecule.
, preferably 100 to 250 S units and 10 to 40
00, preferably 100 to 1000 B units.

The S content is generally between 1O and 95, preferably 40
~90% by weight.

Block polymer B is preferably 0.3 to 3, especially 0
．． It has an intrinsic viscosity of 5 to 1.8 dl, Q (5.?
/i I-determined at 25°C at the concentration of toluene).

Block polymers may be synthesized by anionic polymerization in liquid hydrocarbons as solvents in known manner. The structure of the block polymers obtained in this way can vary widely. In the simplest case, the block polymer in question is a block polymer of the SB type. A modification of such a block polymer is a block polymer containing a transition block (gradually changed structure) symbolized by S-3B-B, where SB changes from "styrene-rich" to "butadiene-rich". It is a block whose composition changes continuously. They are formed during the simultaneous polymerization of both heptamers. Coupling of living block polymers yields structures of the 5-B-3 type or, with polyfunctional couplers, yields structures of the (SB)nC type, where C is the coupler molecule and n is the coupling Ring valence. It is also possible to make block polymers by alternating addition of heptamers, in which case block polymers of the (SB)n-3 type result. It is also possible to make polymers that terminate in diene blocks. Other structures are obtained by alternating separate and combined additions of monomers. Block polymer structure (vinyl content of diene component,
It is also known to those skilled in the art that the random distribution of monomers) is influenced by the reaction temperature and the choice of solvent. In addition, additional branches are incorporated by adding small amounts of divinylbenzene. Another variable is the quantity ratio of the nanatsuma.

It is also possible to use heptamer mixtures for the synthesis of hard and soft blocks. For example, styrene and σ−
Methylstyrene or butadiene and isoprene. These heptad polymers may represent other blocks.

Another type specifically used for the preparation of modifying component (C) described below is styrene grafted SB block polymers.

The modified aromatic vinyl compound/diene polymer (C) is obtained by a halogenation reaction involving the butadiene component of the aromatic vinyl compound/diene polymer, hereinafter also referred to as S/B copolymer.

Polymers suitable for modification are any of the block polymers mentioned above with respect to (B). It is also possible to use random aromatic vinyl compound/diene copolymers. A halogenation reaction is to be understood as a reaction carried out on an olefinically unsaturated group or an allyl group, leading to the introduction of a halogen and, where appropriate, OH or -0. These methods are known, for example halogenation with /% halogen elements, preferably chlorine, alkoxychlorination by the binding action of chlorine in the presence of alcohol,
Hydroxyhalogenation with alkali metal hypohalites and reaction with organic hypochlorites, such as t-butyl hypochlorite, leading to the formation of chlorohydrin. Another method is to use N-halogen compounds such as N,N-dichlorodimethylhydantoin, trichloroisocyanuric acid, dichloroglycolluryl, chloramine T1 sodium dichloroisocyanurate, N-bromosuccinimide. Reaction of dichlorocarbene with the double bond of the butadiene unit can also be used. The products obtained are characterized by their halogen content.

With respect to component C, "improved" according to the invention generally means modification with 0.03 to 2.3 moles of modifier per mole of butadiene units.

The lower limit for halogen content is generally about 1% by weight.

The upper limit is determined by the diene content of the S-B polymer. It is achieved when the double bond is fully saturated. The actual halogen content achieved depends on the type of halogenation reaction (eg chlorination, hydroxychlorination, dichlorocarbenylation). In some cases, even the allylic hydrogen atom is further replaced by a halogen or HCl
After elimination of , the new double bond formed may be rechlorinated.

The product may also contain a relatively small number of carbonyl groups as a result of the oxidation process.

The mixture of components A, B and C may be used both in undiluted form and also diluted with a solvent or swelling agent. In the former case, the mixture may be applied from the melt, whereas in the latter case, the mixture is preferably applied by solution application and evaporation of the solvent. Suitable solvents are low boiling liquids, preferably aromatic and cycloaliphatic hydrocarbons and alcohols, and more preferably ketones such as butanone and acetone, esters such as ethyl acetate, methylene chloride and toluene. . In many cases mixtures of the abovementioned solvents are particularly advantageous.

Solutions of the mixtures of the invention in solvents can be prepared in a conventional manner. The order in which the components should be dissolved is easily determined by preliminary testing. The mixtures according to the invention may contain customary stabilizers such as phenolic antioxidants for stabilizing component B and stabilizers against dehydrohalogenation such as epoxides for component C.

In addition, the mixture may contain fillers, dyes and other polymers. To obtain specific properties, e.g. phenolic resins, ketone resins, colophony derivatives,
Natural or synthetic resins such as phthalade resins, acetylcellulose or nitrocellulose may also be added to the mixture.

Polyisocyanates may optionally be added as component (C) to the mixture of components A-C immediately before use in order to improve the thermal stability of the bond. Typical examples of polyisocyanates are diisocyanates and triisocyanates. Preference is given to adding triisocyanates, such as triphenylmethane triisocyanate or thiophosphoric acid tris-(p-incyanatophenyl ester).

Description of adhesive ingredients The components of the mixture are characterized as follows.

PUI: High thermoplastic, low crystallinity (Weakly cry)
stallizing) polyester polyurethane. Solution viscosity in methyl ethyl ketone (MEK 15% by weight) -
0,2±Q, lPa・S (Brookfield, spindle 3.60 rpm, 23°O) (■ Desmocol (De
smocoll) 110, Bayer A
G) products).

PU2: Highly thermoplastic, highly crystalline polyester polyurethane. Solution viscosity (15% by weight in MEK): 0.6=i:Q
, 2 Pa-5 (O des upper col 400).

PU3: Average thermoplastic, very highly crystalline polyester polyurethane. Solution viscosity (15% by weight in MEK)
: 1.2±0.2 Pa-5 (@Desujokol 510S
).

PU4: Very highly crystalline polyester polyurethane with low thermoplasticity. Solution viscosity (15% by weight in MEK):
1.2=I=O-2Pa-5 (■Desujokol 536).

PU5: average thermoplastic highly crystalline polyester polyurethane. Solution viscosity (15% by weight in MEK): 1.8
±0.3 Pa-s (@Desujokol 540).

SBI: Styrene/butadiene block polymer of SBS type, butadiene content 64% by weight, intrinsic viscosity in dichloromethane [? ] = 79 cm'/7 (0 C1ariflex l l O2, a product of Shell).

SB2: Transition block ([gradually changed (L
Styrene/butadiene block polymer of the SBS type with apered) structure and a butadiene content of 25% by weight. Intrinsic viscosity in toluene [vl-80Cm3/9
(O Stereon 872 A, a product of Firestone).

SB3: SB containing 20% by weight of butadiene
block polymer. Tg -80°C, melt flow index (lokg/200°C -87°C, Vicat B
-56°C (■ StyroluX,
BASF products).

Polyisocyanate A: Tris-(p-incyanatophenyl ester) thiophosphate, methylene chloride solution, N
C○ content: 5.4±0.2% by weight.

Bonding operation Flexible PVC (
Dioctylphthalade (45% by weight) was bonded to a filled sole material based on a styrene/butadiene block polymer. After application to a 15 x 3 cm strip, both sides were left in the air for 30 minutes, after which the sample on the thermoplastic rubber side was exposed to an IR generator (7 Funck type A100O).
activator) for 4 seconds.

Immediately thereafter, the specimens were stacked on top of each other and heated to 0,4 MPa.
Press for 10 seconds at room temperature under pressure of 1.

Immediately thereafter (within 30 seconds), perform the first test for peel strength using a tensile tester (instantaneous value, crosshead speed 10 mm/
minutes). Another test was conducted one day later, and a further test was conducted nine days later. In a modified operation, 5 phr of polyisocyanate A was added to the solution just before application of the adhesive. The result in each case is "no addition of incyanato"
Or indicated by "incyanato addition".

Example A 3002 of modified (halogenated) styrene/butadiene block polymer SB2 was dissolved in 2600 ml of methylene chloride. Chlorine gas 1202 was introduced at 40° C. over 5 hours. Solutions of modified block polymers were processed by methanol precipitation or stripping (dropping the solution into hot water). For stabilization, an epoxide stabilizer was added in advance. Chlorine content 21-23% by weight.

Example B Modification of 5B2 with sodium hypochlorite solution 40I of SB2? was dissolved in 360 mff of methylene chloride with stirring. Add 0.52 of phase transfer catalyst followed by 15
Aqueous solution 509% by weight of sodium hypochlorite was added dropwise.

Next, 1.5 mff of triethylamine was added. The mixture was heated to 40°C and reacted for 4 hours with stirring. The organic solution was stripped with steam and the precipitated product was dried under vacuum at 60°C. Chlorine content 1.9% by weight.

Example C Tricabrylmethylammonium chloride 12 was converted into SB
2 to a 7.4 wt% chloroform solution of SB2 containing 302% KO, followed by 50 wt% KO at a maximum temperature of 50°C.
80ml of H aqueous solution was added dropwise.

The organic phase was then extracted twice by shaking with distilled water, after which the polymer was precipitated by pouring into methanol. After another dissolution and reprecipitation, the product has a chlorine content of 9.9
Weight % is shown.

Example D SB2 202 was dissolved in methyl ethyl ketone 3352. A solution of trichloroin cyanuric acid 51 in methyl ethyl ketone 459 was added dropwise to the resulting solution with stirring at room temperature. After 5 hours, the solution containing many small gel particles was used to prepare an adhesive solution.

Example E 81 of SB2 and l)-toluenesulfonic acid amide 10.
9 to methyl ethyl ketone 280. ? It was dissolved in Trichloroisocyanuric acid dissolved in methyl ethyl ketone 402 2.0. ? It was slowly added dropwise to the obtained solution at room temperature. After stirring for 5 hours, the modified SBS was used to prepare an adhesive mixture.

Example F Trichloroin cyanuric acid 12.67 in methyl ethyl ketone 40+Ila was converted to P in methyl ethyl ketone 859
U3 was slowly added dropwise to the 15I solution at room temperature while stirring. Obtained solution 10.8. ? was poured into a solution of 42 SB2 in 195+nQ of methyl ethyl ketone. 3
After heating at 0-40°C for 5 hours, the modified SBS was used to prepare adhesives. After isolation of the reaction product, IR spectra showed that N-chlorine compounds were formed from PU3 in the first step and chlorinated SB2. Therefore, P
A mixture of U3 and modified SBS is obtained.

Example G Chlorine gas 102 in methylene chloride 345I SBS 3
02 solution over 30 minutes at 40°C. The system was purged with nitrogen, 0.32 g of diglycidyl ether of bisphenol A was added, and the product was precipitated by pouring the solution into methanol. Vacuum dry at 50°C. Chlorine content 21.8% by weight.

Example I 80 parts by weight of PU3, 10 parts by weight of SBI and parts by weight of the modified S/B polymer lO prepared according to Example A are combined in amounts such that a mixture having a solids content of 20% by weight is produced. It was dissolved in methyl ethyl ketone (MEK). Mixtures were similarly prepared according to the data in Table 1 and used to bond PVC to thermoplastic sole materials. The results of the foil super strength test are shown in Table 1. For comparison,
Bonding was performed with 100% PU3, a mixture of PU3 and PUI, and a mixture of the modified S/B polymer of Example A and PU3. The results clearly show that, both in terms of instantaneous strength and final strength, only the claimed mixture gives the values prescribed by the DIN standard (instantaneous > 187 mm, after 9 days > 5 N/mm).

Storage stability of the mixture (solvent methyl ethyl ketone) The claimed mixture is stable for several months. They are cloudy-looking two-phase systems containing permanently finely dispersed particles with no tendency to settle. The mixture of components A and B appears clear as a solution and shows no signs of separation.

Example 2 Modification of the polyurethane components shows that the principle of ternary mixtures is broadly applicable. Both highly crystalline, highly viscous polyester polyurethanes with different thermoplasticity and also those with low solution viscosity can be used. The results are summarized in Table 2.

Example 3 (Control) For comparison, an experiment was conducted using the halogenated polymer shown below as a modified polymer. For this purpose, 80 parts by weight of PU3, 10 parts by weight of SBI and 10 parts by weight each of the polymers listed in Table 3 are dissolved in methyl ethyl ketone;
A 20% by weight adhesive solution was produced. The results show that none of these polymers are comparable to the modified S/B polymers.

Table 3 Adhesive mixtures using other halogenated polymers Halogenated polymer 1) Peel strength (N/mm) Immediately after adding incyanat After 1 day After 9 days Pergut S 10 1.3 2
．． 1 2.3 Pellgate S40 0.7
2.8 2.9 Pelgate S90 0.
8 2.2 2.2 Hypalon
) 40 0.3 1.7 1.9 Bayer (Ba
yer) CM4231) 0.4 1.1 1.
4 Baypren 210 0-5 1
．． 3 1.5 biprene, modified” 0.3
1.0 1.41) 80 parts by weight of adhesive mixture PU3, 110 parts by weight of 5B, tot parts of halogenated polymer,
Solids content 20% by weight.

2] ■Biprene 210 chlorinated in the presence of ethanol
, chlorine content 44.9% by weight.

Example 4 In this example, other polymers were also polyurethane, SBS
To illustrate scales added to a ternary mixture of block polymer and modified SB polymer. for example,
80 parts by weight of PU3, 7.5 parts by weight of SBI, chlorinated 5
B2CCU content 23.0% by weight) 7.5 parts by weight and ■
Plexigum M 319 (copolymer of methyl methacrylate and ethyl methacrylate) 5
The weight part of the mixture is 2. Instantaneous value of ON/mo+ and 6,6
Give the final value (after 9 days) of N/mm (addition of isocyanate).

A similar mixture of 75.10.10 and 5 parts by weight of the same ingredients is 1. The instantaneous value of ON/ms was given. Without the addition of incyanate, the final value was 5. It was ON/mm.

Example 5 Adhesive from 30 parts by weight of chlorinated SB polymer (chlorine content 1.9% by weight) prepared according to Example B using 50 parts by weight of PO2, 20 parts by weight of SB2 and an aqueous hypochlorite solution A mixture was prepared.

The peel strength was as follows.

Immediately after addition of incyanate 1 day later 9 days later 1.3
3.5 4.8 The results show that modified SBS polymers with very low chlorine content also provide useful adhesive mixtures.

This example also demonstrates the use of unmodified SB block polymers other than SBI.

If SBI is an SBS-type linear polymer with sharp transitions between blocks, a transition block of varying composition (gradually changing block) exists between the styrene block and butadiene block of SB2, and in addition The styrene content of SB2 is clearly higher than that of SBI (
33% vs. 75%).

Example 6 A 20% by weight butanone solution was prepared by adding PO2 (80 parts by weight) and SBI (10 parts by weight) to parts by weight (solid) of the modified SBS block polymer IO obtained according to Examples and E. . The conjugate was prepared in the same manner as in Example 1. The bond peel strength of this mixture satisfies the requirements of the DIN standard (Table 4).

Table 4 Results of bonding with modified SB block polymers obtained in Examples and E Modified SBS Incyanate Addition Example Immediately After 1 day 9 caliber 6A D 1.8 4.2 5.06
B E 1.1 4.0 5.9 Example 7 329 of PO2 and 4 g of SBI were added to the solution obtained according to Example F and dissolved with stirring. A 20% by weight solution was used for bonding in the same manner as in Example 1.

Peeling strength (N/mm) Immediately After 1 day After 9 days 1.
0 2.5 4.4 Examples 8A-C (Control) These examples show that modified S used alone as a primer
BS polymer shows no useful bonding (8A
). Modified SBS polymer and SB used as primers
A mixture of I (ratio 1:l) also gave negative results (8B
). Finally, unmodified SBS was included in the experiment as a control primer (8C). After priming with the above, T
R Bond strength to PVC with PU3 solution applied on the sole surface Example Primer 1) Peel strength Immediately after addition of incyanate 1 day later 9 days later 8A Modified SBS of Example A O, 80, 83, 88
B SBI/SBS mixture of Example A (1:l) 0.6 1.6 3
．． 48CSB2 0.7 0.4
3.6+) After 1 hour of primer coating Example 9 80 parts by weight of PO2, 10 parts by weight of SBI and 10 parts by weight of the modified S/B polymer prepared according to Example G
A mixture in EK was prepared as in Example 1. The peel strength is as follows.

Example Incyanate No isocyanate added
addition

Claims (1)

[Claims] 1) A) 20 to 99 parts by weight of soluble polyurethane, B) 50 parts by weight of aromatic vinyl compound/diene block polymer
Up to parts by weight, C) Modified aromatic vinyl compound/diene polymer 0.5~
50 parts by weight, and D) 0 polyisocyanate, optionally dissolved in an organic solvent.
~10 parts by weight of the mixture. 2) A mixture according to claim 1, wherein component C is a polymer obtained by halogenation of an aromatic vinyl compound/diene polymer. 3) A mixture according to claims 1 and 2, wherein component C is a polymer obtained by chlorination of a styrene/butadiene block polymer. 4) Use of the mixtures according to claims 1 to 3 for joining rubber, leather or plastic parts. 5) Use of a mixture according to claim 4 for bonding styrene/butadiene block polymers and rubber or leather parts. 6) Use of a mixture according to claim 4, in which polyisocyanate is additionally present. 7) Use of the mixture according to claim 1 for coating rubber, leather or plastic parts.