DD215792A1 - METHOD FOR PRODUCING AN INJECTION CASTING POLYVINYL CHLORIDE MASS - Google Patents

Abstract

A process for producing an injection moldable polyvinyl chloride composition having improved processability for producing injection molded articles. Preparation of the polyvinyl chloride composition by adding graft copolymers based on an atactic polypropylene and one or more partially grafted on homopolymers or copolymers to the polyvinyl chloride. The preparation of the graft copolymers can be carried out by known polymerization. The object of the invention is to produce a polyvinyl chloride composition with improved processability on the basis of new starting materials in an economical manner. It leads to products with improved toughness, lower processing temperatures, a wider processing range and improved aging resistance.

Description

• 7

- Title of the invention

Process for the preparation of a sprayable polyvinyl, chloride, ",.

Field of application of the invention .

The invention relates to a method for producing a. Polyvinyl chloride wet sit improved processability Beisi injection molding. '-. ,

Characteristic of the known technical solutions

The production of injection-processable polyvinyl chloride masses is possible on several occasions · A known way of producing polyisocyanates which can be injection-molded is to copolymerize vinyl chloride with up to a maximum of 20% by weight of another co-monomer , methacrylates, ethylene, maleic or Vinylisobutylester comes, especially cen copolymers with vinyl acetate and propylene is highly important (L. 1. iiass ί Encyclopedia; of PVC, ITe w York, Basel. üarcel Dekker Inc. 1976, Vol 1, S Increasing the proportion of vinyl acetate in the copolymer with vinyl chloride leads to a lowering of the melt viscosity and thus to a better processability, but at the same time also to a reduction of the thermal stability of the copolymer compared to pure polyvinyl chloride The presence of propylene in the copolymer improves next to the Erniedri additionally the heat stability of the products. 2This is an improved procedure. Vinyl chloride and propylene ¹ additionally polymerized in the presence of polypropylene or a chlorinated product thereof with at least 63 percent by mass chlorine (DE-OS 2,165,050).

Other known methods for the processing of polyvinyl chloride in injection molding are the addition of such polymeric substances that are effective as impact modifiers or processing aids. Such Schlagzähniodifikai: oren are z. B. ", crylnitrile / methacrylate ^ butadiene-Styrsn graft polymers (eg DE-OS 2,603,992), chlorinated polyethylene (eg GB 1 475 716), ethylene-vinyl acetate copolymers and graft polymers (eg 3" BE 817 593), grafted acrylate elastomers (eg SP 2813) and ethylene-propylene-diene terpolymers (eg GB 1 545 249). Less effective Schlagaähmodifikatoren, z. -B. Polyolefin-Vinyl Halide Graft Polymers (PR 1 409 968, GB 1 097 019, DD 137 112) * The largest ITachteil of all mentioned

. ' , : y

Modifiers consists of their action primarily, the maximum improvement of a property, e.g. E. the toughness, reduced at a relatively high modifier amount and a sufficient improvement in the processability of the products in the 'injection molding by adding modest amounts of modifier is not possible. Another drawback is that the achievement of the specific properties of high impact polymers due to the multiphase structure of the products requires a very accurate adjustment and maintenance of the processing conditions to form optimal structures of the elast phase in the hard phase. Processing aids are high polymer thermoplastic. Plastics which, upon addition of small amounts, bring about a marked improvement in the processing properties of the polymer composition (H. Gächter / H. Müller: Taschenbuch der Kunststoff-Additives, Carl Zeiss Verlag 1979) and with regard to their effectiveness with regard to improving the processing behavior significantly better As additives for processing are »Since processing aids are strongly wall-adhering substances and, in the melt show a Scherfließen, they lead as additives during processing in general to an increase in the melting viscosity of the polyvinyl chloride. As a result, the polymer is subjected to greater mechanical shear, which causes a higher temperature of the polymer melt and thus improved thertnoplasticity of the polyvinyl chloride. However, shows pure polyvinyl chloride without processing aids to about 190 ⁰ C graft "nfließen and only from about 210 ⁰ C predominantly shear flow, 'τ; οdurch during the processing of a slow, non-homogeneous melting, - to" local thermal · overloads and eventually you - »- gelhaften mechanical properties and below is an uneven η distribution of _additives'; the main processing Help of sweeteners are methacrylate copolymers 3asis of polymethylene that Sthy-1-acrylate as comonomers, butyl acrylate, butyl me methacrylate or styrene may contain.. In this case, suspension products with a relatively low molecular weight lead to a reduction in the melt viscosity of the polyvinyl chloride and are predominantly suitable for processing in the temperature range from 160 to 130 ^° C.

Known processing aids are also styrene-acrylonitrile copolymers, χ-methylstyrene-acrylonitrile copolymers (F. Förster, M. Herner: Kunststoffe 69 (1979) 146) and olefin-carbon monoxide copolymers (SE-OS 2 433722). Substantial disadvantages of the above-mentioned processing aids are often high costs, which often also limit the amount of use or their preferential effect as a component to increase the heat resistance, but due to the high amounts of juice, the character of the processing aid is not given. ,. ,,,

Object of the invention _:.

The object of the invention is "to produce a polyvinyl chloride grade having improved processability without deterioration, the other performance characteristics.

Explanation of the essence of the invention .

The technical task.

The invention has the object of providing a method for 'producing a injection-moldable Polyvinylchloridniasse old improved processability using commercially available Polyvinylchloridtypen, which can be prepared by known methods, and in existing, technical equipment without adversely affecting the other properties anwendungstechnischeη, su _{entwickeln.-.} ,

Features of the invention - ^:

The object is achieved in accordance with the invention by virtue of the fact that it is a vinyl chloride polymer; 0.01 to 30 parts by weight based on 100 parts by weight of polymer of a graft copolymer 3 consisting of. From 10 to 93% by weight of an atactic polypropylene with a molecular weight of. 10 000 to 30 000, and 2 to 90 Hasseprozeiit

one or more grafted onto the polypropylene monomers, added as a modifying component. According to the invention, all vinyl chloride and / or copolymers, such as those obtained by the known polymerization processes, and to which any known processing aids and fillers are added, may be used. ......'_.

As graft monomers which can be grafted onto the atactic polypropylene, vinyl halides and / or vinyl esters and / or alkyl acrylates and / or Alkylsiethacrylate and / or styrene and its substituted derivatives and / or αοηο-olefinically unsaturated nitriles are suitable. :,

The injection moldable polyvinyl chloride compositions prepared by the process of this invention exhibit improved toughness, ease of processing at low processing temperatures, a broad processing range, and improved resistance to aging, good VTeform resistance, tensile strength and toughness, and a smooth, glossy surface thereof over double bond-containing modifiers molded parts produced by injection molding.

Embodiments .- '-. , ';

Example 1,.

1 part by mass of a graft copolymer was treated with 9-r Massetei the Polyvinylchloridmasse described in Comparative Example A len on a kneader at a processing temperature of-175 ⁰ C and mixed with respect to its mechanical-containing physical '

tested for physical properties. It could at the. Preparation of the test specimens already bei.einer rolling temperature of 15-5 ⁰ C successfully homogeneous rolling file are produced. The results are summarized in Table 1. The polyvinyl chloride composition obtained using the graft copolymer had greatly improved processability and toughness. ''"For the preparation of the graft copolymer used 125 iiasseteile atactic polypropylene which contained 18.6 rlasseprosent at 25 ⁰ C in η-Heptan'unlösliche units, 125 parts by mass of vinyl acetate and 0.25 .Masseteile therein were dissolved Dibenscyl-

ρeroxide for one hour in 750 pale parts of water, mixed with 1.25 parts of water. Polyvinyl alcohol 65/15, at et-.va 25 ⁰ C in a: Autoclave dispersed. ", '... The mixture was then polymerized at a temperature of ⁰ C with stirring SSO six hours.

Each / separating and. Washing the product with V / asser, the drying was carried out at 50 ⁰ C. . ' -.- to. Characterization of the product, the degree of grafting was

Let the grafted. Monomers ' \

Right

grafting

Mass of the parent polymer

To do this: the methanol soluble fraction of-.Homopolyvinyiacetat was removed by twenty-hour extraction below. With shaking at about 25 ⁰ C and the angepfropfte -polypropylene weighed together with the graft *

Comparative Example A - ^:.

A normally processable polyvinyl chloride composition was prepared by mixing the following suspensions of 10% of hate particles of a polyvinyl chloride suspension emulsion polymer with the E-type 60: _.

3j 5 Leaving Oiodif iedea dibutyl sensecaptide

1.3 parts by weight of lubricant '' ^: . '

0.25 ilasseteile U7 stabilizer

0.01 parts by weight ültramaririblau. '

The results of the test are shown in Table 1

^ T'e '". ¹ ' ³ '"' 3 ^ ^ ' ^Ί 3 * οβ ~' 3Ό ~ ^ el 3

these

· ^ .-; νergj.eicns3e ^ 3 "CIEI wira .an -st- · ^=;?

tell =

1 part of the pure, grafted atalctische .... PolypropyIen.3 used and abgemiscat with S Llaaseteilen the example described in comparison k polyvinyl chloride. Bei.der processing of this hate occurred. Difficulties due to inhomogeneities due to very strong sticking to the metal parts, on Table 1 shows the results obtained with this mixture. From this it can be clearly seen that the "positive properties of the finished polyvinyl chloride by the invention by means of a simple mixing the unmodified polypropylene can not be obtained ^.

Ex iel 2

A corresponding graft product was prepared analogously to the formulation described in Example 1 'and 1 Uasseteil this grafting' '

, - '' · ⁸

Product mixed with 19 parts by weight of the polyvinyl chloride composition of Comparative Example A The resulting composition had improved processability and had the properties listed in Table 1.

Example 3 _. '"'.

The mass fraction of another polypropylene-vinyl acetate graft product was blended with .9 parts by weight of the polyvinyl chloride grade of Comparative Example A. The results are also given in Table 1. This product also showed improved processability over the normal polyvinyl chloride composition. ..-

To produce the polypropylene-vinyl acetate graft product used, 29 hate particles of atactic polypropylene, 221 parts of vinyl acetate, 0.44 part of dibenzoyl peroside and 750 parts of water were placed in an autoclave and dispersed with stirring for one hour. , , , . ' Subsequently, for six hours at 70 "C ¹ polymerized. The certain analogy to Example 1 grafting betrug'0,74 ·

Example 4 . '.' ,. '. ,. '.

A mass part of a polypropylene-vinyl acetate-vinyl chloride graft product was blended with 13.4 parts by mass of the Polyvinylchloridmasse from Comparative Example A on a kneader at a processing temperature of 175 ⁰ G · The results of Off test is shown in Table 2. The preparation of the graft by one hour dispersing ¹ of 125 parts by weight of vinyl acetate, 125 parts by weight of atactic polypropylene and Ό, β25 LIasseteilen Dibenzoyiperosid in with 0.125 ^/ parts by weight of polyvinyl alcohol 65/15 added 750 parts by weight of water and polymerized for ⁶ hours at a temperature of 70 ⁰ C * There was a graft with a by example .1 determined grafting degree of 0.50.

Q;

200 Llasseteile of this product were together with 182. Lilasseteilen. Vinyl chloride, 1,6 E ¹ Ia ss et rush ή Dilauroylpe'roxid, 800 Liasseteilen water and 0.3 parts by mass of polyvinyl alcohol in .einem / autoclave presented dispersed for one hour at about 25 ⁰ C ^and: then polymerized for six hours at 60 C.

Example 5 . '' ^:

/ A prepared according to Example 4 polypropylene-vinyl acetate graft product having a degree of grafting of 0.45 was grafted analogously to Example 4 with vinyl chloride and 1 part by weight of this product with 6.94 parts by mass' in Comparative Example. A mixed polyvinyl chloride mass. The product was easy to process and had the properties listed in Table 2. '<

Example 6 '''''''

9.5 parts by mass of a graft product of vinyl acetate and vinyl chloride on polypropylene were blended on a kneader with 8.5 parts of the Polyvinylchloridma'sse from Verglechsheispiei ä at a processing temperature of 175 ^W C, so that the content of polypropylene-vinyl acetate graft in -Bndprodukt 10 Liasse-%. This product was also characterized by easy and problem-free processing (see table)

The graft product of vinyl acetate and vinyl chloride on polypropylene used by grafting using 33.3 parts by weight of vinyl chloride and 0.29 part by weight Dilaurovlper o.sid according to Example 4 to 6.66 parts by weight of a polypropylene also prepared according to this example. Vinyl acetate 'graft product has been obtained.

'.- · ¹⁰ '

Example 7 -

Sin polypropylene-vinyl acetate graft product was prepared analogously to Example 4. "·. · · ^: ..

2 parts by weight of the product obtained were processed for testing on an injection molding machine (screw cutter: 56 mm) according to the following recipe:...

, 100 parts by mass of polyvinyl chloride suspension polymerizate aiit

a Έ value of 52 '. ,

6 .Masseteile Lubricant · ·

2'Masseteilβ ^: sulfur-containing di-n-octyizinnstabilisator 1.4 parts by weight of colored pigment. 1 part of mass eposidiertes soybean oil.

At an injection pressure of 130 kp / cnr, shells of square format were sprayed off. Even at relatively low Verarbeitu.ngstemperaturen (150 ⁰ C) .konnten shapes are produced, the "through · full Ausforniung and good surface quality (smooth, shiny and streak-free surface) distinguished themselves ....

Comparative Example C '

Analogously to the formulation listed in Example 7, a polyvinyl chloride mass without addition of graft product on the Spritzgießautotnat was processed under the same conditions, but. However, the full formation of the tool higher processing temperatures (ISO ⁰ C) were required. "Streaks and discoloration often occurred at the Surface of the semi-finished products on ... ^: ; ''. \ ' .'', ...

The comparison of this example Tnit Example 7 clearly shows the greatly improved Terarbeitbarkait ¹ and surface quality of the polyvinyl chloride compositions prepared using the graft described.

Tobeilen

Table Ii Summary of the polyyirgated with polypropylene-vinyl acetate graft products

Example Impact Bending Impact Strength

at 23 ⁰ C at -20 oq

Tensile-- Ball-pressure- Vicat-hardness, 60 "soft-

temperature

Processing bark it

8.5 3.0

2.7

6,1 3,5

60.0 / 4 χ 512 1133 77 improved 8.6 599 1146  78 , normal 27.2 / 2 χ 215 675 76 bad 48.5 / 2 χ 549 1211 77 improved 59.6 / 4 x 566 1158 77 improved

χ »Number of 20 not broken chopsticks

Table 2: Summary of the characteristics characterizing the Polyvinylcliloridmasa blended with polypi-vinyl acetate-vinyl chloride graft products

Example melt index> processability

Temperature load 'value

190 21 6 ö , 0 normal 180; 10 0 70 improved 180 10 69 , 2 ' improved 180 21 6 ό 9.3 verbeaaert

Claims (2)

Claim A process for the preparation of an injection moldable polyvinyl chloride composition having improved processability, characterized in that a vinyl chloride polymer of 0.01 to
80 parts by weight, based on 100 parts by weight of polymer, · one
Pfropfeopolytnerisat3, consisting of 10 to 98 percent by mass. an atactic polypropylene with a molecular weight of. 10000 to 80,000 and 2 to 90% by weight of one or more partially grafted onto the polypropylene Honomerer added * 2. The method according to claim 1, characterized in that the
monomers grafted onto the amorphous polyolefin are vinyl halide monomers and / or vinyl esters and / or alkyl acrylates
and / or -alkyl methacrylates and / or styrene and its substituted derivatives and / or monoolefinically unsaturated nitriles, are «