SU639903A1 - Thermoplastic composition - Google Patents

Description

3

copolymers with a central Outadiene block and two different terminal vinyl aromatic blocks, one of which, for example, polystyrene, and the other poly-methyl styrene. The total content of the end blocks is 25-50 7 °, since the replacement of block-polymers containing more than 50 ° 7 blocks A for this purpose leads to a sharp increase in the residual elongation at break. On the other hand, in the case of the total content of A blocks less than 25%, comosities based on them have low strength properties.

Polkuretanacetal, the specified formula is obtained by the interaction of urethane-containing diol 2,4-xylylene-btsc-2-hydroxyethylcarbamate with diethylene glycol divinyl ether and polyethylene adipate. The polyurethane acetal used has an average of t. Pl. 60 ° C and the following indicators of physical and mechanical properties:

Breaking strength 30-35 kgf / cm

Relative extension

700-750

at break,%

Residual elongation

at break,% 40-45

Using polyurethane acetal more

ai

f × Ig) g-OCNH-CH ,, - ™ CO- (CH,) j, -0 CH-o4cH,), - 0- () j-0-CH-0- (CH ,,) 2-OC - (C4H8) -CO- (CKi)

70 weight. this is impractical due to the fact that stratification can occur during the molding of the composition.

Known metal oxides (zinc oxide) can be added to the composition, which, in addition to the stabilizing effect on polyuretapatal, reduces the composition, and, in addition, increases its thermal conductivity, which leads to a decrease in the molding time, and 10–40 wt. hours, reducing the adhesion of the granules of the mixture when loaded into the molding machine and improve the quality of the product surface.

The proposed composition is prepared by displacing on rollers or in a rubber mixer of block copolymer ABA and polyurethane acetal at a temperature of at least 80 ° C, if block A is polystyrene, and at least 95 ° C, if block A is poly-a-methylstyrene. Polyurethane acetal should be introduced gradually to obtain a more uniform mixture.

Examples 1-6. Composition based on 100 weight. including styrene-butadiene styrene block copolymer (with a total styrene content of 30%) and the introduction of 10, 30, 40, 50, 60 and 70 weight. including polyurethane acetal formula

SNS

chV)

with mol. a mass of 60,000 is produced by rolling at 80 ° C for 20 minutes.

Physico-mechanical casting properties of the composition are given in table. one.

56

Physico-mechanical and molding properties of the composition

 The readings are taken at 150 ° C,

Physico-mechanical and molding properties of the proposed composition

639903

Table 1

table 2

Example 7 (control). Composition based on 100 in. including styrene-butadiene-styrene block copolymer (with a total styrene content of 30%) and the introduction of moliuretanatal acetal, the specified formula, mol. weighing 60,000 in the amount of 80 weight. hours get rolling at 80 ° C for 20 minutes

Examples 8-10 (control). For comparison, a series of control compositions based on 100 wt. including styrene-butadiene-styrene block copolymer with the introduction of a copolymer of ethylene and vinylacetate as a polymer additive (vinyl acetate content is 18 wt.%, the melt index is 6 at 160 ° С and the load is 5 kg).

Examples 11-14. Composition based on 100 weight. including styrene-butadiene-styrene block copolymer (with a total styrene content of 50%) with the introduction of 20, 40 and 60 wt. h. Physico-mechanical and molding properties of the compositions of Example 17. Composition based on 100 weight. including styrene-butadiene-α-methylstyrene block copolymer (total α-methylstyrene content is 35%), taken in a mixture with 25% weight. including styrene-butadiene-styrene block copolymer (styrene content 50%) with the addition of 100 weight. h. ZnO and 10 in. including JiOz, designed to make the bottom of the shoe using a casting method under pressure, with the introduction of 30%. including polyurethane acetal, the specified formula with mol. weighing 10,000 and 10 wt. including paraffin naphthenic oil is produced by rolling at 95 ° C for 20 mph. Properties of the composition are given in table. 4. Thus from the table. 1 shows that the insertion of the polyuretapacetal into the blockpotimer

polyurethane acetal of the specified formula with mol. mass 40,000, obtained by rolling at 80 ° C for 10-20 minutes.

The properties of the composition are given in table. 2

Example 15. Composition based on 100 weight. Part of block copolymer St 5ol-butadiene-α-methylethyrol (total styrene and α-methylstyrene content 35%) with introduction 30 wt. including polyurethane acetal of the specified formula with mol. weighing 10,000, they can be milled at 95 ° C for 15 minutes.

Example 16 (control). Composition based on 100 weight. including styrene-butadiene-α-methylstyrene block copolymer (total styrene and α-mystyl-styrene content 35%) with the introduction of 30 wt. including paraffin naphthenic oil is produced by rolling at 95 ° C for 15 minutes.

The results in table. 3

Table 3 of the type ABA, compared with ethylene copolymer; 1111 acetate gives the composition, on the one hand, a much smaller residual elongation, and on the other hand, significantly better casting properties. (especially with heavy loads). From tab. 1 and 2 also with. That the optimal value for: m - msr-s; 1 spacer is the limit of 10-70 Bev. h. From table. 3 and 4, it is clear that 1d sds ;:; s:; o: 1Iurethane acetal in an ABA block copolymer, compared with the introduction of paraffin-naphthenic oil, gives the composition a higher modulus in stretching, strength and hardness, as well as quite large loads. 910 Physico-mechanical and cast properties of compositions

An important advantage of the composition is a very strong decrease in melt viscosity with increasing load (compared to the prototype - a composition based on vinyl aromatic hydrocarbon block copolymer (block A) and conjugated diene (block B) of type ABA with ethylene-vinyl acetate copolymer using narafinnaften oil) which makes it possible to effectively use such compositions for products obtained by methods associated with high shear stresses, for example, injection molding, or by extrusion on powerful tools. However, the use of polyurethane acetal as a polymer additive has very little effect on hardness and residual elongation.

t i Sn, - og-u - n., -: cng-knso - (ots) ;. o - it - o - (cn) - 0- (CHj j-0-CH-0- (CHj) 2-QC- (C4H8) -CO- (CHj) j-Cl-CH-j

sn.

with mol. weighing 10,000-100,000 in quantities

10-70 weight. hours per 100 weight. h block copolymers.

Information descriptions.

639903

Table 4

and significantly less, compared to oil, reduces the modulus at stretching and tensile strength.

Claims (1)

Invention Formula A thermoplastic composition based on the bicot-polymer of a vinyl aromatic hydrocarbon and a conjugated diene with a total block content of vinyl aromatic hydrocarbon 25-50%, including a polymer additive, characterized in that. that, in order to increase the flow properties while maintaining the physico-mechanical properties of the composition, the latter contains polyurethane acetal of the formula Sh.Z oo CH, taken into account in the examination 1. UK patent 1188922 Cl. SZR, pub. 1970.