DD290432A5 - INTERCONNECTION POLYBUTYLENEPEPHTHALATE MOLDING - Google Patents

Abstract

Perforated polybutylene terephthalate (PBTP) molding compositions are prepared by adding one by grafting of acrylic acid and maleic anhydride, including their mixtures with styrene, to semicrystalline ethylene-vinyl acetate copolymers having a vinyl acetate content between 5 and 25% (EVAC-5/25) in the dry, powdery state obtained until koernigen medium carboxylated EVAC-5/25 product with a required for construction materials characteristic levels, in particular a high (notched) impact resistance while ensuring the parameters hardness, stiffness, strength and heat distortion resistance, equipped to 70-95 parts by weight of PBTP 5 bis 30 parts by weight of a total of between 0.2 and 5% carboxyl groups and a gel mass fraction (undeluted fraction of a certain amount of product in a corresponding amount of solvent after 12 hours' refluxing treatment) of between 20 and 80% are added. {Polybutylene terephthalate; impact modifier; carboxylated EVAC graft polymerization products; Construction material; (Notched) impact strength; mechanical-physical characteristic level; * * Carboxyl group content; Spritzgieszen}

Description

The invention relates to impact-resistant polybutylene terephthalate (PBTP) molding compositions which have a characteristic value level which is characteristic of impact-resistant construction materials and an improved processability by addition of a semi-crystalline ethylene-vinyl acetate copolymer of the composition 5 to 25 parts by weight of vinyl acetate IVAO / 95 to 75 parts by mass of ethylene monomer units ,

Characteristic of the known technical solutions

Of the polyalkylene terephthalates, in particular, PBTP represents a valuable construction material due to a number of important properties, such as high rigidity, surface hardness, abrasion resistance, heat resistance, dimensional stability and rapid processability (high crystallization rate) (DE 2756167, US 2,465,319, US 3047539).

For many applications, however, the (notch) impact resistance of PBTP, especially in the temperature range from 0 to

-30 ⁰ C, not enough.

In addition to various methods of direct modification of the PBTP structure, in particular the synthesis of defined block copolyesters with PBTP blocks as the main part (DE 2756167, DE 3040999) and the obtained by additional Elnkondensation aliphatic or 4basischer carboxylic acids or higher diol mixtures copolyester structures, although to A further increase in impact strength but at the same time lead to an unacceptably high drop in heat resistance, rigidity and still other mechanical-physical characteristics (DE 1900270, DE 2407674, DE 2407776, DE 2715932, US 3692744), the addition of elasticizing components has proven to be a suitable method (DE 1694170, DE 2248242,

DE 37252987; US 4231922).

In the majority of PBTP's impact-resistant equipment, ethylene-vinyl acetate copolymers (EVAC) are used which, depending on the processing or fields of application, both in composition within a wide range of 5 to 70% VAC (DE 3328566, DE 3227028) as well as their proportion within the total mixture between 0.05 and 30% by mass, preferably 5-15% by mass (DE 1694168, DE 3227028), can be varied or specifically selected

can.

In addition to the impact resistance of reinforced / filled PBTP molding compositions by means of EVAC (DE 2454002, DE 2756698, DE 3040999, US 4101502), the modification of unfilled and unreinforced PBTP with EVAC has the same importance (DE 2855512,

DE 2454002, DE 3328566).

The relationship between impact strength and overall mechanical / physical level (stiffness, hardness, tensile strength) and the magnitude of the drop in heat deflection temperature are determined by the EVAC concentration in the PBTP

Molding material significantly influenced.

For a number of applications, for which a relatively small increase in the notch impact level (up to a doubling) is sufficient, 0.1 to 4.5 parts by mass (MT) EVAC to 100MT PBTP are sufficient (US 4369280;

DE 3040999, DE 2855512, DE 2855521).

For other purposes, higher (notched) impact strengths are required, which can be achieved by adding EVAC (VAC between 10 and 50%, preferably 45% VAC: EVAC-45) or VAE (VAC between 50 and 70%) in an amount between 5 and

30%, preferably from 20 to 25%, can be achieved (DE 3328566).

By several hours of inert gas treatment of the / produced under melting conditions EVAC-PBTP molding compound / semi-finished product (powder, granules, pellets) at a temperature of 15-60 ⁰ C below the melting temperature of the pure PBTP, impact-resistant molding compounds with only a small decrease in thermal and mechanical-physical characteristics,

obtained (DE 3328566). However, this method is technically very complicated.

Furthermore, more effective modifiers which allow either a low elastomer level (about 0.3 to 4.5MT) to be used for a required toughening improvement or only a minor decrease in the other processing if a higher level of elastification component is used (up to 35MT per 100MT PBTP) - and application technology important

Characteristics known by chemical treatment of the EVAC Elastiflzierkomponente.

In addition to the direct Einpolymerisatlon a third Mnnomerkomponente In the EVAC-Kotto, whereby the corresponding Terpolymers, such as e.g. Ethylene-vinylacote-methyl-acrylate-tDE 3040999) and ethylene-vinylacetate-glycidyl methacrylate · Terpolymers (JAP 63117049, JAP 5592759) as suitable impact modifier in concentrations of preferably 5-10%

can be obtained, a higher impact resistance within the PBTP molding compositions to be equipped also by addition

a chemically-aftertreated EVAC's.

Known in this context are those with a high techno-technological effort held hydrolyze EVAC products using high vinyl acetate-containing VAE (60 mol% VAC) are very pure poly (ethylene vinyl) alcohols

(EVAI) for improving the impact and wear resistance as well as the surface integrity of PBTP molding compounds (DE 3725287) and using EVAC with lower VAC contents EVAI for the impact resistance of PBTP within a wide concentration range (2-80MT EVAI, to 100MT PBTP) give (JAP 60076325).

Another method of "adapting" the EVAC to the PBTP matrix consists in the graft modification of the Elastomer component by means of unsaturated carboxylic acids, such as acrylic acid (AS) or methacrylic acid (MAS), in the EVAC Melt (DE 2343486). By adding 0.5 to 35MT of graft-modified EVAC (12-33% VAC) with 0.5-10% grafted-on AS portion to 100M PBTP

a significant impact improvement is achieved (DE 2454002), such. B. by a proportion of 10% of a 4% AScdrboxyllerten EVAC-33-Schmelzpfropfproduktes an approximately 50% increase in the notched impact strength in the interest

Temperature range (+ 2ObIs -3O ⁰ C). Also, by DI tert-butyl peroxide grafting of 0.01-10Ma .-% maleic anhydride (MSA) to molten EVAC (6-35% VAC) modifiers produce a higher impact strength increase for larger proportions

(JAP 5578008, JAP 55069648).

A disadvantage, however, is the limited modifier effectiveness of most in a kneader or extruder in the EVAC melt

Carboxylated EVAC products with the mechanical-physical and thermal characteristics required for use as impact modifiers under technically difficult conditions and complicated process control.

This modifying effectiveness can - taking into account the absolutely necessary mechanical-physical Basic levels - defined by the (notched) impact strength achieved for a given modifier concentration

become.

Goal of Erflndun j

The object of the invention is the cost-effective production of impact-modified PBTP molding compositions with improved processing and application properties.

Explanation of the essence of the invention

The invention is based on the object, PBTP by means of impact modifiers based on semicrystalline EVAC according to a copolymer composition 5 -? * Iviassenteile VA '- / 95-75 parts by mass of ethylene units (EVAC-5/25), which while maintaining a dry powdery to granular consistency means polar monomer from the series ethyleni3ch unsaturated mono- and dicarboxylic acids or their anhydrides has been graft-modified, with a characteristic of impact-modified construction materials characteristic level, in particular a high impact and impact strength within a broader temperature range (a _n and a _k values for ± 20 ° C according to TGL14068) while ensuring a sufficient hardness / rigidity / strength level and a satisfactory heat resistance.

According to the invention the object is achieved in that 5 to 30 parts by mass (MT), based on 100 MT of the molding composition, a total of a mass fraction between 0.2 and 5% carboxyl groups and a gel mass fraction between 20 and 80% having EVAC-5 / 25- (Co) graft product are added to the PBTP.

The carboxylated EVAC-5/25 products are obtained by (co) grafting unsaturated carboxylic acids or dicarboxylic acids or their anhydrides, preferably of acrylic acid (AS), maleic anhydride (MSA) or AS / MSA mixtures, wherein additionally a further comonomer how styren, in particular, can be used with different mass fractions.

The (co) Pf ropfreaktion running in dry powdery or granular phase, using free-radical organic initiators, preferably from the series of known diacyl peroxides and dialkyl peroxydicarbonates in concentrations between 5 and 30%, based on the total monomer used at polymerization temperatures between 30 and 100 ⁰ C performed.

Use as impact modifiers of the (co) graft products P (EVAC-5/25-g-AS (S) l or P [EVAC-5/25-g-MSA (S)] obtained in this way in a heterogeneous phase those having a gel mass fraction m _G , i, defined as the percentage solution residue under specified conditions (2 g product weight in 100 ml xylene after 12 hours of refluxing treatment) and, as stated above, between 20 and 80% within a broad range of melt index MFI (19O ⁰ C, 212N basis weight; TGL 25244), that is, practically from non-measurable (nm) to about 50 g / 10 min.

The PBTP matrix material are high molecular weight linear glycol esters of terephthalic acid which have relative solution viscosities (according to TGL 29202/02) of between 1.5 and 1.8 and are generally synthesized according to the known synthetic procedures, i. have been prepared by polycondensation of equimolar compositions of terephthalic acid and its esters and butanediol-1,4, wherein the reactants in lower concentrations also corresponding derivatives or homologs such. Isophthalic or other aromatic dicarboxylic acids and also ethylene glycol or aliphatic (cycloaliphatic) diols having from 4 to 6 carbon atoms (Kunststoff-Handbuch, Vol. VIII, page 695, Carl Hanser Verlag, Munich 1973, J. Polymer Sei. Part A1 4 (1966), pp. 1851-1859).

Auiföhrungebeliplel

In a twin-screw extruder (old granules) biw. Brabenders are Baal forming masts of 75 to 90 MTPBTP (solution viscosity: 1.645, density: 1.31 g / cm ¹ ) and 10 to 25MT carboxylates EVAC-5/25 using twin-stranded backbone polymers (EVAC-16 / VAC). Content: 15.3%, M _n / M _w : 23000/141000, EVAC-18 / VAC content: 18.2%, lvT "/ M * _w : 29200/177000), which were then applied to an injection molding machine of the type KuASY 150/50 (tool: bohoizte sealing nozzle, temperature profile: 230/240/250 ° C, mold temperature: 8O ⁰ C, injection pressure: 3.5 MPa) to ISO test specimens 80 x 10 χ 4 mm ¹ processed.

Purpose Comparison with the orfordungsgemäßen, listed in Table 1 Mc difikatoren (Lfd. Nos. 1 to 10) are the following bekonnte or comparison modifiers

* unmodifiedEVAC-18 (see 11)

Ethylene-acrylic acid copolymer with 10% of copolymerized AS (see 12)

in the powder phase, vinyl chloride-doped EVAC-15P (85 EVAC-15g-15VC) (see 13)

various EVAC-35 products melt-grafted using MSA or AS or corresponding comonomer mixtures and di-tert-butyl peroxide as initiator between 160 and 200 ° C. (compare 14-see FIG.

used and tested in an analogous manner.

Table 1: Carboxylated EVAC modifiers used, including comparative modifiers (composition and characterization)

.11 Modifier production commitment of graft monomers (MT) styrene more Comon. Modifier key data at UPT 212 N Lf d .12 EVAC RQckgrat AS MSA 5 - Γ-COOHJ / - (VN 66.5 (G / io ·) No. .13 100 MT template 5 - - - 2.52 38.2 5.4 1 .14 EVAC 18 2.5 - - - 1.21 37.0 3.6 2 .15 EVAC 18 5 - - - 2.62 69.7 0.19 3 .16 EVAC 18 7.5 - 2 - 4.12 55.4 n.m. 4 .17 EVAC 18 8th - - - 3.43 20.6 1.74 5 EVAC 15 0.5 - - - 0.26 52.0 2.1 6 EVAC 15 - 2.5 5 - 1.64 25.4 0.44 7 EVAC 18 - 2.5 5 2.21 36.5 10.6 8th EVAC 18 3.3 1.7 - 8 MMA ^; 2.93 70.5 40.8 9 EVAC 18 5 - - - 2.76 - 0.05 10 EVAC 15 - - - - - - 35.8 See EVAC-I8 10 - - 20 VC ² ^ 6.25 9.5 - See Ethylene-AS-CP - - - - - 1.2 1.1 See EVAC 15 5 - - - 2.34 0.0 9.8 see EVAC 35 - 0.3 2.5 5.3 BA 0.22 0.1 12.8 See EVAC 35 2.5 - - 1.31 2.5 12.6 See EVAC 35 - 1.3 1.01 15.2 See EVAC 35

1) methyl methacrylate / 2) vinyl chloride / 3) n-butyl acrylate

The specimens are regarding

- Impact bending · and basket punched sheet ammonia * ^; t a. and a _k (TGL 14068),

Tensile strength σ, (BO mm / min, TGL 140/0)

Bend strength or Blogeeloetlzitätemodul O ₀₁₄ or E _b (TGL 14 067)

- Ball pressure hardness (30sec. Penetration time) H _K (TGL 20924)

- Vlcat heat resistance WFB (TGL 17274) tested.

On the basis of the most important test parameters given in Table 2.1 for the molding compositions based on the special "heterogeneous" grafted sleep rate modifiers (Table 1: high golmitinantoils between 20 and 70%), it can be seen that the modifier effectiveness compared to the effect of known impact resistant components (Tab 2.2.) Is higher overall. This result is expressed above all in the higher impact values a "and a _k as well as the E _b values per mass fraction modifier.

Table 2.1 .: Inventive molding compositions (composition and characteristic values)

Ser. No. Proportion modifier (MT) to 100 MT total molding material a +20 (kD / m ¹ ) ⁰ C -20 ⁰ C K e η η w e r 2.3 "Egg t e  ? ^h k WFB O - 100 η. % 20s. % / 33 a _k (kO / m ¹ ) +20 ⁰ C -20 ⁰ C 3.9 63 _r 5 ^E b (N / mm 53 93 174 1 10 P (EVAC-g-5 AS / 5 S) 100 a ·% 65 % / 54 2.7 5.1 52 1820 49 85 152 2 15 P (EVAC-g-5 AS / 5 S) 100 % 90 % / 84 7.7 5.9 50 1650 39 79 143 3 20 P (EVAC-g-5 AS / 5 S) 100 % 100 % 9.8 4.6 46 1559 37 69 129 4 20 P (EVAC-g-2.5 AS) 100 % 80 % / 73 14.7 4.8 45 1433 36 71 122 5 20 P (EVAC-g-5 AS) 100 % 80 % / 79 8.1 7.8 44 1321 36 70 127 6 25 P (EVAC-g-5 AS) 100 % 100 % 8.3 4.6 43 1353 34 69 124 7 10 P (EVAC-g-7.5 AS) 100 % 75 % / 65 16.3 4.5 51 1285 50 89 149 8th 15 P (EVAC-g-8 AS / 2 S) 100 % 80 % / 75 6.7 * 2 52 1662 43 78 147 9 20 P (EVAC-g-0.5 AS) 100 % 90 % / 7S 7.8 4.6 42 1520 42 80 138 10 20 P (EVAC-g-2.5 MSA) 100 % 100 % 7.9 7.1 44 1230 36 105 125 11 25 P (EVAC-g-2.5 MSA / 5 S) 100 % 100 % 7.7 6.1 42 1351 35 64 121 12 15 P (EVAC-g-3.3 AS / 1.7 MSA / 5 S) 100 % 85 % / 76 15.2 48 1285 46 84 140 12.6 1485

N. G. = not broken (100% means that none of the specimens are broken.) 2. Numerical value

behind percentage for a (-20 ⁰ C): value for the broken specimens)

1) Use of EVAC-15 or EVAC-18 can be seen from Table 1

Table 2.2 .: Comparative molding compounds (composition and characteristic values)

Ser. No. Proportion modifier (MT) to 100 MT total molding compound a +20 (kO / rn ¹ ) η ⁰ C -20 ⁰ C K +20 ⁰ C e η η w e r t e b & s (S / M ¹ ) 53 ^h k O - 100 % 20 % / 33 2.7 J / ··) -20 ⁰ C ^ BI, 5 1820 47 93 See .. 13 10 P (EVAC-g-5 AS / 8 MMA) 80 65 % 30, 6 % / 43 5.5 2.3 63 1580 50 83 Vgl.14 20 P (EVAC-g-5 AS / 8 MMA) 100 % 85 % / 72 7.8 3.3 47 1335 37 81 Vgl.15 20 EVAC-18s 100 % 25 % / 45 3.5 3.6 44 1165 36 70 Vgl.16 10 E / 10 AS-CP 100 % 70 % / 60 2.9 2.6 37 1105 41 68 Vgl.17 20 P (EVAC-g-20 VC) 100 % 85 % / 75 5.1 2.3 38 1282 49 70 Vgl.18 10 P (EVAC-35-g-5 AS) 100 % 50 % / 45 6.0 3.1 40 1582 45 75 Vgl.19 20 P (EVAC-35-g-5 AS) 100 % 100 % 8.7 2.6 49 1385 42 72 Vgl.20 25 P (EVAC-35-g-0.3 MSA) 100 % 100 % 11.5 3.5 46 1185 45 71 vgl.21 15 P (EVAC-35-g-2.5 AS / 2.5 S) 100 % 60 % / 46 6.9 3.9 37 1220 42 69 Vgl.22 20 P (EVAC-35-g-1, 3 MSA / 5.3 BA) 100 % 85 % / 75 8.5 3.4 38 1146 67 3.7 38

Claims (1)

Toughened polybutylene terephthalate (PBTP) molding compositions based on the addition of an impact modifier by grafting polar monomers such as acrylic acid (AS), maleic anhydride (MSA) and AS · and MSA-styrene mixtures on partially crystalline ethylene-vinyl acetate copolymers of composition 5 to 25 mass point vinyl acetate / 95 to 75 parts by mass ethylene monomer units (EVAC-5/25) has been obtained while maintaining a dry powdery to granular consistency of the polymerization medium, in order to equip the PBTP with a characteristic level required for construction materials, in particular a high impact and impact strength within a wider temperature range while securing the characteristics, hardness, rigidity, strength and heat resistance, characterized in that to 5 to 30 parts by mass, based on 100 parts by mass of the molding composition, a total of a Massonanteil between 0.2 and 5% Carboxylgrupp > n and a gel mass fraction between 20 and 80% containing EVAC-5/25 (co) grafted product are added to the PBTP. Field of application of the invention