HK1060891B - Moulding materials with a dibenzoate additive - Google Patents

Description

Molding compositions containing dibenzoate ester additives

The invention relates to compositions comprising a matrix polymer, a graft polymer and a special combination of additives, to the use of said compositions for producing moulded bodies and to the moulded bodies obtained therefrom. The invention also relates to the additive combination itself.

ABS molding compositions have been used for many years in large quantities as thermoplastic resins for the production of a wide variety of molded articles. The range of properties of such resins spans from relatively brittle to very tough.

A particular field of application for ABS molding compositions is the production of molded articles by injection molding (e.g.housings, toys, automobile parts), where it is particularly important for the polymer material to have good flowability. In addition, the molded articles thus produced must generally have excellent notched impact strength.

The object of the present invention is to produce ABS moulding compositions which have very good thermoplastic flowability while retaining good toughness values, these properties being obtained without changing the basic building blocks of the polymers used. The commonly employed methods of increasing the amount of processing aids used often result in a loss of other properties and a significant increase in cost.

It has now been found that ABS moulding compositions having very good thermoplastic processability, while retaining good toughness values, can be prepared by using special additive mixtures.

The present invention provides a thermoplastic molding material (or composition) comprising:

A) from 5 to 95% by weight, preferably from 10 to 90% by weight and particularly preferably from 20 to 75% by weight, of one or more thermoplastic homopolymers, copolymers or terpolymers of the following monomers: styrene, alpha-methylstyrene, styrene substituted in the ring, methyl methacrylate, acrylonitrile, methacrylonitrile, maleic anhydride, N-substituted maleimide or mixtures thereof,

B) from 5 to 95% by weight, preferably from 10 to 90% by weight and particularly preferably from 25 to 80% by weight, of one or more graft polymers of the following components:

b.1) from 5 to 90 parts by weight, preferably from 20 to 80 parts by weight and particularly preferably from 25 to 60 parts by weight of styrene, alpha-methylstyrene, ring-substituted styrene, methyl methacrylate, acrylonitrile, methacrylonitrile, maleic anhydride, N-substituted maleimide or mixtures thereof are grafted onto

B.2)95 to 10 parts by weight, preferably 80 to 20 parts by weight and particularly preferably 75 to 40 parts by weight of at least one rubber having a glass transition temperature of < 10 ℃,

and

C)0.5 to 10 parts by weight, preferably 1 to 8 parts by weight and particularly preferably 1.5 to 6 parts by weight (in each case based on 100 parts by weight of A) + B)) of a mixture of a) and B) and/or c), where a) is at least one dibenzoate of a di-or trialkylene glycol and B) is at least one compound comprising at least one of the following structural units:

and/or c) is at least one compound comprising at least one of the following structural units:

each of the compounds b) and C) preferably comprises at least one terminal aliphatic C₆-C₃₂A hydrocarbon group.

Suitable thermoplastic polymers A) according to the invention are polymers of the following monomers: styrene, alpha-methylstyrene, p-methylstyrene, vinyltoluene, halostyrenes, methyl acrylate, methyl methacrylate, acrylonitrile, maleic anhydride, N-substituted maleimides or mixtures thereof.

The polymers A) are resinous, thermoplastic and rubber-free. Particularly preferred polymers A) are polymers of the following monomers: styrene, methyl methacrylate, styrene/acrylonitrile mixtures, styrene/acrylonitrile/methyl methacrylate mixtures, styrene/methyl methacrylate mixtures, acrylonitrile/methyl methacrylate mixtures, alpha-methylstyrene/acrylonitrile mixtures, styrene/alpha-methylstyrene/acrylonitrile mixtures, alpha-methylstyrene/methyl methacrylate/acrylonitrile mixtures, styrene/alpha-methylstyrene/methyl methacrylate mixtures, styrene/alpha-methylstyrene/methyl methacrylate mixtures, styrene/maleic anhydride mixtures, methyl methacrylate/maleic anhydride mixtures, styrene/methyl methacrylate mixtures, styrene/methyl, styrene/acrylonitrile/N-phenylmaleimide mixtures.

The polymers A) are known and can be prepared by free-radical polymerization, in particular by emulsion, suspension, solution or bulk polymerization. Their preferred molecular weights20,000 to 200,000 and an intrinsic viscosity [. eta. ]]From 20 to 110ml/g (measured in dimethylformamide at 25 ℃).

Rubbers suitable for producing the graft polymers B) are, in particular, polybutadiene, butadiene/styrene copolymers, butadiene/acrylonitrile copolymers, polyisoprene or those based on acrylic acid C₁-C₈Alkyl acrylate rubbers of alkyl esters, in particular ethyl acrylate, butyl acrylate, ethylhexyl acrylate.

The acrylate rubber optionally may contain copolymerized therein up to 30% by weight (based on the weight of the rubber) of monomers such as vinyl acetate, acrylonitrile, styrene, methyl methacrylate and/or vinyl ethers. The acrylate rubbers may also contain polymerized therein small amounts, preferably up to 5 wt.% (based on the weight of the rubber), of ethylenically unsaturated monomers having a crosslinking action. Crosslinking agents are, for example, alkylene glycol diacrylates and dimethacrylates, polyester diacrylates and dimethacrylates, divinylbenzene, trivinylbenzene, triallyl cyanurate, allyl acrylate and methacrylate, butadiene and isoprene. The graft base may also be an acrylate rubber having a core/shell structure in which the core is a diene rubber of crosslinked one or more conjugated dienes, such as polybutadiene, or a copolymer of a conjugated diene with an ethylenically unsaturated monomer, such as styrene and/or acrylonitrile.

Other suitable rubbers are, for example, the so-called EPDM rubbers (polymers of ethylene, propylene and a non-conjugated diene such as dicyclopentadiene), EPM rubbers (ethylene/propylene rubbers) and silicone rubbers, which optionally may also have a core/shell structure.

Preferred rubbers for preparing the graft polymers B) are diene rubbers and alkyl acrylate rubbers and EPDM rubbers.

The rubber is present in the graft polymer B) in the form of at least partially crosslinked particles having an average particle diameter (d)₅₀) From 0.05 to 20 μm, preferably from 0.1 to 2 μm and particularly preferably from 0.1 to 0.8. mu.m. Average particle diameter d₅₀According to W.Scholtan et al, Kolloid-Z.u.Z.Polymer 250(1972), 782-796, by ultracentrifugation measurements or by measuring electron microscope images.

The polymers B) can be prepared by free-radical graft polymerization of the monomers B.1) in the presence of the rubbers B.2), the monomers B.1) being grafted onto the rubbers B.2).

Preferred preparation processes for the graft polymers B) are emulsion, solution, bulk or suspension polymerization and combinations of these processes known per se. Particularly preferred graft polymers B) are ABS polymers.

Very particularly preferred polymers B) are products prepared by free-radical polymerization of mixtures of styrene and acrylonitrile, preferably in a weight ratio of styrene to acrylonitrile of from 10: 1 to 1: 1, particularly preferably from 5: 1 to 2: 1, in the presence of a rubber, preferably a polybutadiene, which may contain up to 30% by weight of styrene and/or acrylonitrile as comonomer, consisting essentially of diene monomers and having an average particle diameter (d)₅₀) From 100 to 450nm, the two rubbers consist essentially of diene monomers, preferably polybutadiene, which may contain up to 30% by weight of styrene and/or acrylonitrile as comonomers, and have a) an average particle diameter (d)₅₀) From 150 to 300nm and b) an average particle diameter (d)₅₀) From 350 to 450nm, wherein the weight ratio (a) to (b) is from 10: 90 to 90: 10, preferably from 30: 70 to 60: 40.

The rubber content of the polymers B) is preferably from 40 to 95% by weight, particularly preferably from 50 to 90% by weight and very particularly preferably from 55 to 85% by weight.

Suitable individual components of the additive mixture C) are, for example and preferably:

as component a): diethylene glycol dibenzoate, triethylene glycol dibenzoate, dipropylene glycol dibenzoate, tripropylene glycol dibenzoate; mixtures from these compounds are particularly preferred.

As component b): ethylenediamine bisstearamide, erucamide, oleamide, stearic acid amide, behenamide, montanic acid amide; ethylenediamine bisstearamide and/or erucamide are preferred, and ethylenediamine bisstearamide is particularly preferred.

As component c): glycerol tristearate, glycerol trioleate, glycerol tribehenate, glycerol triteroonoate, stearyl stearate, stearyl oleate, stearyl behenate, stearyl montanate, oleyl stearate, oleyl oleate, oleyl behenate, oleyl montanate, behenyl stearate, behenyl oleate, behenyl behenate, behenyl montanate, octyl stearate, isooctyl stearate, lauryl oleate, glycerol monostearate, glycerol distearate, glycerol monooleate, glycerol dioleate, pentaerythritol tetrastearate, pentaerythritol tetraoleate, pentaerythritol tetrabehenate, pentaerythritol tristearate, pentaerythritol trioleate, pentaerythritol tribehenate, and the like, Pentaerythritol distearate, pentaerythritol dioleate, pentaerythritol dibehenate, pentaerythritol ditehenate, pentaerythritol monostearate, pentaerythritol monooleate, pentaerythritol monobehenate, pentaerythritol monomontanate; preference is given to glycerol tristearate, stearyl stearate or pentaerythritol tetrastearate, and particular preference is given to glycerol tristearate or pentaerythritol tetrastearate or in each case mixtures thereof.

The moulding compositions according to the invention may also comprise further additive components which are advantageous with regard to processing properties.

Examples of such compounds are, for example, metal-containing long-chain substances, such as and preferably magnesium stearate, calcium stearate, zinc stearate, magnesium montanate, calcium montanate, zinc montanate, magnesium behenate, calcium behenate, zinc behenate, magnesium oleate, calcium oleate, zinc oleate; preference is given to magnesium stearate or calcium stearate, and particular preference to magnesium stearate, or other long-chain substances, such as and preferably paraffin oil, hydrocarbon wax, low-molecular-weight polystyrene, which make use of C₈-C₁₈Alkanethiols as molecular weight regulators, average molecular weight: () From 2000 to 15,000, preferably from 2500 to 12,000 and particularly preferably from 3000 to 10,000, low molecular weight styrene/acrylonitrile copolymers which utilize C₈-C₁₈Alkanethiols as molecular weight regulators, average molecular weight: () Low molecular weight alpha-methylstyrene/alkenenitrile copolymers of 2000 to 15,000, preferably 2500 to 12,000 and particularly preferably 3000 to 10,000, using C₈-C₁₈Alkanethiols as molecular weight regulators, average molecular weight: () From 2000 to 15,000, preferably from 2500 to 12,000 and particularly preferably from 3000 to 10,000, of low molecular weight polymethyl methacrylates, using C₈-C₁₈Alkanethiols as molecular weight regulators, average molecular weight: () From 2000 to 15,000, preferably from 2500 to 12,000 and particularly preferably from 3000 to 10,000, C₆-C₃₂Alkanols, such as and preferably oleyl alcohol.

Preference is given to paraffin oil, low molecular weight styrene/acrylonitrile copolymers or alpha-methylstyrene/acrylonitrile copolymers, and particular preference is given to paraffin oil or low molecular weight styrene/acrylonitrile copolymers or in each case mixtures thereof.

In the addition according to the invention, the weight ratio of components a) and b) and/or C) in the additive component C) is from 10: 1 to 1: 5, preferably from 8: 1 to 1: 4 and particularly preferably from 5: 1 to 1: 2.

Particularly preferred mixtures consist of the following components: 15 to 65% by weight of a graft polymer obtained by grafting 25 to 60 parts by weight of styrene, alpha-methylstyrene, acrylonitrile, N-phenylmaleimide or mixtures thereof onto 75 to 40 parts by weight of polybutadiene, wherein the polybutadiene may contain styrene and/or acrylonitrile as a comonomer in an amount of up to 30% by weight,

85 to 35% by weight of a thermoplastic copolymer consisting of 5 to 40 parts by weight of acrylonitrile and 95 to 60 parts by weight of styrene, alpha-methylstyrene, N-phenylmaleimide or mixtures thereof, and

1.5 to 6 parts by weight of a combination of the following components per 100 parts by weight of a + B:

a) mixtures of diethylene glycol dibenzoate, triethylene glycol dibenzoate and dipropylene glycol dibenzoate,

b) ethylenediamine bisstearamide, and/or

c) Pentaerythritol tetrastearate or glycerol stearate.

The mixtures of the invention, which comprise A), B) and C) and optionally customary additives such as processing aids, stabilizers, pigments, antistatics, fillers, are prepared in a known manner by mixing the individual components simultaneously or successively at room temperature or elevated temperature and then melt-compounding or melt-extruding the mixture at temperatures of from 150 to 300 ℃ in customary apparatus such as internal kneaders, extruders or twin-screws.

The molding compositions of the invention can be used for producing any type of molded bodies, where conventional production methods can be used and the molded bodies can be produced, in particular, by injection molding.

Another form of processing of the molding compositions according to the invention is the production of moldings by deep-drawing of sheets or films previously produced by known methods.

The invention therefore relates to a process for preparing the composition, to its use for the production of moulded bodies and to the moulded bodies obtained therefrom. The invention also relates to the additive combination itself.

Examples

Thermoplastic resin A1

Random styrene/acrylonitrile (72: 28) copolymer, determined by GPC (gel permeation chromatography)Is about 85,000.

Graft Polymer B1

A graft product prepared by emulsion polymerization of: 42% by weight of a styrene/acrylonitrile mixture (weight ratio 73: 27) were grafted onto 58% by weight of a 1: 1 mixture of two particulate polybutadienes having a) an average particle diameter (d)₅₀) 290nm and b) an average particle diameter (d)₅₀) Is 420 nm. Work-up was carried out by coagulating the latex with magnesium sulfate, washing with water and subsequent drying in vacuo.

Graft Polymer B2

A graft product prepared by emulsion polymerization of: 50% by weight of a styrene/acrylonitrile mixture (weight ratio 73: 27) are grafted onto 50% by weight of a particulate polybutadiene having an average particle diameter (d)₅₀) Is 130 nm. The post-treatment is as described in B1.

Additive agentCa：Benzoflex^®2088 (mixture of 50 wt.% diethylene glycol dibenzoate, 25 wt.% triethylene glycol dibenzoate, and 25 wt.% dipropylene glycol dibenzoate) (Velsicol, Rosemont, IL., USA)

And (3) additive Cb: ethylenediamine bis-stearamide (Henkel KG, Dusseldorf, Germany)

Additive Cc: pentaerythritol tetrastearate (Henkel KG, Dusseldorf, Germany) the components were mixed in accordance with the parts by weight indicated in Table 1, together with 0.5 part by weight of magnesium stearate and 0.15 part by weight of silicone oil, in a 1.3 l internal kneader at a temperature of 160 to 200 ℃. The molded bodies were produced on an injection molding machine at 240 ℃.

Notched impact Strength (unit: kJ/m)²) At room temperature (ak) according to ISO 180/1A^RT) And-30 deg.C (ak)^-30℃) Evaluation of the thermoplastic flowability was determined by determining the melt flow index (MVR) according to DIN 53735U (unit: cm³10 min).

As can also be seen from Table 1, a good combination of good toughness and excellent thermoplastic processability is obtained only when the mixtures according to the invention are used.

Table 1: composition of the Molding compositions and test data

Example No. 2	A parts by weight	B1 parts by weight	B2 parts by weight	Ca weight part	Cb parts by weight	Cc parts by weight	akRT(KJ/m2)	aK-30℃(KJ/m2)	MVR(cm3/10min)
										1	75	12.5	12.5	1	1	-	14	8	38
2	75	12.5	12.5	2	1	-	13	8	45
										3	75	12.5	12.5	2	-	1	17	8	39
4	75	12.5	12.5	1	2	-	15	7	45
										5	75	12.5	12.5	2	2	-	14	7	53
6	75	12.5	12.5	3	2	-	14	6	62
										7 (comparison)	75	12.5	12.5	1	-	-	13	8	30
8 (comparison)	75	12.5	12.5	2	-	-	13	8	34
										9 (comparison)	75	12.5	12.5	-	1	-	14	8	27
10 (comparison)	75	12.5	12.5	-	2	-	14	7	35
										11 (comparison)	75	12.5	12.5	-	-	1	17	9	27
12 (comparison)	75	12.5	12.5	-	-	-	14	8	25

Claims (12)

1. A thermoplastic composition comprising:

A)5 to 95 weight percent of one or more thermoplastic homopolymers or copolymers of the following monomers: styrene, alpha-methylstyrene, styrene substituted in the ring, methyl methacrylate, acrylonitrile, methacrylonitrile, maleic anhydride, N-substituted maleimide or mixtures thereof,

B)5 to 95 weight percent of one or more graft polymers of:

b.1)5 to 90 parts by weight of styrene, alpha-methylstyrene, styrene substituted in the ring, methyl methacrylate, acrylonitrile, methacrylonitrile, maleic anhydride, N-substituted maleimide or mixtures thereof, to which

B.2)95 to 10 parts by weight of at least one rubber having a glass transition temperature of < 10 ℃,

and

C) per 100 parts by weight of A) + B)0.5 to 10 parts by weight of a mixture of a) and B) and/or c), wherein a) is at least one dibenzoate of a di-or trialkylene glycol, B) is at least one compound comprising at least one of the following structural units:

c) is at least one compound comprising at least one of the following structural units:

with the proviso that the compound in c) is not a dibenzoate ester of a di-or trialkylene glycol;

wherein the ratio of the dosage of (a) to (b) or (a) to (b + c) or (a) to (c) is 10: 1 to 1: 5.

2. The composition of claim 1, wherein each of compounds b) and C) comprises at least one terminal group C₆-C₃₂A hydrocarbyl group.

3. The composition of claim 1 wherein compound a) is selected from the group consisting of diethylene glycol dibenzoate, triethylene glycol dibenzoate, dipropylene glycol dibenzoate, tripropylene glycol dibenzoate, or mixtures thereof.

4. The composition of claim 1 wherein compound b) is selected from the group consisting of ethylenediamine bisstearamide, erucamide, oleamide, stearamide, behenamide, montanic acid amide.

5. The composition of claim 1 wherein compound c) is selected from the group consisting of glycerol tristearate, glycerol trioleate, glycerol tribehenate, glycerol trimontenate, stearyl stearate, stearyl oleate, stearyl behenate, stearyl montanate, oleyl stearate, oleyl oleate, oleyl behenate, oleyl montanate, behenyl stearate, behenyl oleate, behenyl behenate, behenyl montanate, octyl stearate, isooctyl stearate, lauryl oleate, glycerol monostearate, glycerol distearate, glycerol monooleate, glycerol dioleate, pentaerythritol tetrastearate, pentaerythritol tetraoleate, pentaerythritol tetrabehenate, pentaerythritol tetramontanate, pentaerythritol tristearate, pentaerythritol trioleate, pentaerythritol trileate, Pentaerythritol tribehenate, pentaerythritol distearate, pentaerythritol dioleate, pentaerythritol dibehenate, pentaerythritol dimontenate, pentaerythritol monostearate, pentaerythritol monooleate, pentaerythritol monobehenate.

6. The composition of claim 1, wherein compounds a), b) and c) are selected in each case from the group consisting of:

compound a): diethylene glycol dibenzoate, triethylene glycol dibenzoate, dipropylene glycol dibenzoate and tripropylene glycol dibenzoate,

compound b): ethylene diamine bis stearamide and erucamide,

compound c): glyceryl stearate, stearyl stearate, and pentaerythritol tetrastearate.

7. The composition of claim 1, wherein C) is contained in an amount of 1.5 to 6 parts by weight per 100 parts by weight of a + B).

8. The composition of claim 1 wherein component b.2 is selected from the group consisting of diene rubbers and alkyl acrylate rubbers.

9. The composition of claim 1, wherein the thermoplastic copolymer is a terpolymer.

10. The composition of any of claims 1-9, comprising processing aids, stabilizers, pigments, antistatic agents and/or fillers.

11. Use of a composition according to any of claims 1 to 10 for the production of moulded bodies.

12. A molded body obtained from the composition of any one of claims 1 to 10.