KR810001564B1 - Composition of a vinylchloride polymer and an impact modifier - Google Patents

Abstract

The impact strength, processability, and heat resistance of PVC are improved by addn. of 25-75 % mixt. of crosslinked (meth)acrylate polymer 5-50, crosslinked acrylonitrile-styrene copolymer(I) 5-35, and uncrosslinked I 15-90%. Thus, PVC contg. 40% mixt. of poly(Bu acrylate) 27.5, crosslinked I 10, and uncrosslinked I 62.5 % has Izod notched impact strength 124.6-139.8 kg-cm/cm, falling dart impact strength 127.12 kg-cm/mm, and heat distortion temp. 80oC, compared with 8.16-9.24, 95.34, and 74.4oC, resp., for a control.

Description

Composition of vinyl chloride polymer and impact modifier

The present invention relates to a composition with a vinyl chloride polymer and an impact modifier which improves the impact resistance when compared to those consisting only of itself. Impact modifiers also act as heat distortion impurity improvers and process aids of vinyl chloride polymers.

The use of three stage acrylic elastomeric impact modifiers in mixtures comprising vinyl chloride polymers is described in US Pat. No. 3,655,826 to R. P. Fellmann et al. In these prior art patents, crosslinked methacrylate / crosslinked styrene / uncrosslinked methacrylate or acrylate compositions have been described. It is said to act as an impact modifier. (3-speed lines 49-52 and 65-70)

The mixture of the present invention comprises a vinyl chloride polymer and an effective amount of crosslinked methacrylate / crosslinked styrene-acrylonitrile / noncrosslinked styrene-acrylonitrile impact modifier composite.

For the purposes of the present invention the term “vinyl chloride polymer” is defined to include both homopolymers and copolymers of vinyl chloride.

The term is also used when referring to chlorinated vinyl chloride polymers having a chlorine content of generally about 56% to about 70% by weight.

Better polymers are homopolymers of vinyl chloride, but vinyl chloride polymers may contain up to about 50% by weight of other unsaturated compounds, such as ethylene, that can also copolymerize with it. Representative examples of unsaturated copolymers such as ethylene include vinyl alkanoates such as vinyl acetate or vinyl propionate and the like, vinylidene bromide, vinylidene chloride, vinylidene fluorochloride and the like vinylidene halides and ethylene. And unsaturated hydrocarbons such as propylene and isobutylene, halogenated hydrocarbons such as chlorinated ethylene and the like, and allyl compounds such as allyl acetate and allyl chloride or allyl ethyl ether and the like.

The term “crosslinked methacrylate / crosslinked styrene-acrylonitrile / non-crosslinked styrene-acrylonitrile polymer composites” is used to refer to the form of the polymer composites described in US Pat. No. 3,944,631 to AJ Yu et al. It is understood by explaining. Such a compound can be formed by three successive polymerizations.

1. At least one monomer fill of C ₂ -C ₁₀ alkyl acrylate or C ₈ -C ₂₂ alkyl methacrylate or a mixture of both (herein referred to herein as “methacrylate”) is suitable for such monomers. Emulsification polymerization in water-soluble polymerization medium in the presence of an effective amount of unsaturated crosslinker such as diethylene or polyethylene with C ₄ -C ₈ alkyl acrylate, which is a better methacrylate monomer for use in this step

2. Emulsifying the monomer packing of styrene and acrylonitrile in the presence of a water-soluble polymer medium and in the presence of an effective amount of an appropriate crosslinking agent such as diethylene or polyethylene, ie the respective phases are surrounded by one another. Emulsion polymerization step wherein the cross-linked methacrylate and the cross-linked styrene-acrylonitrile component, when soaked, are carried out in the presence of the first stage product to form a copolymer.

3. Emulsification polymerization or suspension polymerization of the monomer packing of styrene and acrylonitrile in the absence of a crosslinking agent, in the presence of the resultant product of the second step, if necessary, can be changed in the procedure described above. have.

This product, used as an additive in the mixture of the present invention, can contain up to about 5-50% by weight of the crosslinked methacrylate component as described above, up to about 5-35% by weight of the crosslinking, styrene-acrylonitrile component and non-crosslinking. Styrene-acrylonitrile component consists of about 15 to 90% by weight. It contains little or no graft polymerization between the styrene-acrylonitrile copolymer moiety and the crosslinked methacrylate component and depends on the amount of the three different polymer phases in the composite, but the processing temperature is about 199 to 232.2 ° C. to be.

A more detailed description of this type of polymer composite can be found in US Pat. No. 3,944,631 to A.J. Yu et al., Incorporated herein by reference.

The mixture of the present invention contains two substances, the first being a vinyl chloride polymer (a conventional and gum processing aid, lubricants, stabilizers, fillers, other impact modifiers, flame retardants, dyes and the like selected from And one or more optionally combined), and second, an effective amount of the impact resistance modifier described above for improving the impact resistance and the thermal degradation temperature. Generally, the amount of impact modifier to be used in the present invention is in the range of about 5 to 95% by weight, preferably up to about 25 to 75% by weight of the total formulation.

The impact modifier must be applied in a unique particulate form with an average particle size in the range of about 10 to 100 microns in order to achieve a substantially uniform dispersion in the mixture. To give a commercially desirable impact resistance, the average particle size of the methacrylate portion of the modifier should also be about 0.3 to 1 micron, with the largest impact resistance improvement near the top of the range.

Taking the appropriate reaction conditions to give methacrylate particles having an average particle size in this range would be well done by a person of ordinary skill in the art.

Form of emulsion. Factors such as the concentration of the emulsifier, the pH of the reaction medium and the concentrations of the initiators influence the particle size.

Generally speaking, the use of fewer initiators, less effective emulsifiers to emulsify low concentration monomers of emulsifiers, and pHs between about 5-7 will result in larger particles.

The invention is explained in more detail by the following examples.

Comparative Example 1

This example illustrates that the lzod impact and tensile impact values obtained in the polymerized mixtures of the present invention are unexpectedly large compared to the types of polymerized mixtures described in US Pat. No. 3,655,826 to R. P. Fellmann et al.

Preparation of Representative Impact Resistance Modifier Additives

Step 1: Two additives are prepared by in-situ polymerization of the following reaction mixture in 6 bottles at 65 ° C. for 6 hours and the first preparation of the bound polybutyl acrylate component.

Step 2: In this step, the latex in step 1 is the reactant for the crosslinked polystyrene second stage component according to US Pat. No. 3,655,826 (bottles 1 and 2), but according to the invention (bottles 3 and 4). Polymerization is carried out in the reaction medium given below in the presence of the reactants for the second step cross-linked styrene-acrylonitrile. The reaction is carried out at 70 ° C. for 2.5 hours.

Step 3: In this step, each of the latexes of step 2 is intended to form an additive of the prior art described in US Pat. No. 3,655,826 (bottles 1-3), or an additive used in accordance with the present invention (bottles 4-6). It is polymerized in the reaction medium given below. The polymerization is then carried out at 70 ° C. for 3.25 hours.

The calculated composition (% by weight) of the additive in the prior art in bottles 1-3 is as follows.

Crosslinked polybutyl acrylate-27.5%

Crosslinked styrene-10%

Uncrosslinked Styrene-Acrylonitrile-62.5%

The calculated composition of the inventive additives in bottles 4-6 is as follows.

Crosslinked polybutyl acrylate-27.5%

Crosslinked Styrene-Acrylonitrile-10%

Uncrosslinked Styrene-Acrylonitrile-62.5%

Test of Mixtures Including Each Additive

Additives in bottles 1-3 and 4-6 are placed in polyvinyl chloride composites, respectively, and the physical properties of the resulting mixture are measured. The mixture was mixed with the components listed below, and the plates were placed in a mill with two rolls with a front roll temperature of 179 ° C and a rear roll temperature of 182 ° C, and then plated about 3 millimeters thick. Make

All quantities given below are in grams.

* Additives used according to the invention

The physical properties of each of the above batches are then determined using standard ASTM test procedures. Batch B is a mixture in US Pat. No. 3,655,826 to Pelman et al., While batch A is a mixture in the invention.

The mixture of the present invention (batch A) has a significantly higher tensile and zod impact value than the prior art mixture (batch B) and thus exhibits a large impact resistance of the polymer.

Comparative Example 2

A single mixture of polyvinyl chloride (PVC) and the additives desired to be used in the present invention is made and measured to determine the values of Izod impact, Gardner dart drop and thermal degradation temperature. The method used to make the testo sample is as follows.

1. A PVC master batch was prepared in a Henschel mixer in which the following components were mixed with each other at a speed of 3800 rpm.

The stabilizer is added at 60 ° C., the processing aid at 71.1 ° C., the lubricant at 93.3 ° C., and then heated to 110 ° C. until the entire batch is uniform and then cooled to room temperature.

2. The PVC master batch from step 1 is mixed while varying the amount of additive form used in Comparative Example 1 where the average particle size of the methacrylate component is 0.65 ± 0.15 microns. The mixture is then mixed in a Henschel mixer at 3800 rpm and at a temperature of about 48.9 ° C.

3. Made by injecting various mixtures of PVC and additives. (Feed: 176.7 ° C; Transition Section: 193.3 ° C; Nozze: 198.9 ° C; Mold, ASTM Form: 51.7 ° C)

The following tables show the results obtained for products containing two different types of PVC resins.

TABLE 1

1) A low molecular weight vinyl chloride homopolymer, which can be used as “SCC-614” from Starwoo Chemical Chemical Plastics, Westport, Connecticut, USA.

2) These numbers represent averages from two kinds. (ASTM-256-56 [61])

3) A Gardner Daart Drop on a 6mm x 6mm (15.2cm x 15.2cm) compression template with a thickness of 1.5 millimeters. Using a Gardner-SPI Modified Variable Height Impact Tester No. 1G-1120-MA (Gardini Labora Tori), the 41b (1.8 kg) weight was applied to samples at various heights. The force per millimeter in thickness falling off was recorded in the 50% line of the sample dropped.

TABLE 2

1) It is a high molecular weight vinyl chloride homopolymer and can be used as "SCC-614" from the plastics division of Starwoo Chemical, West Post, Connecticut.

2) These numbers represent averages from two types (ASTM-256-56 [61]).

3) A guidener art drop made on a 6 mm x 6 mm (15.2 cm x 15.2 cm) compression template with a thickness of 1.5 millimeters. Using a Gardner-SPI Modified Barrier Highto-Impact Tester No. 1G-1120-MA (Gardner Laboratories), 41b (1.81 kg) weight is dropped onto the sample at various heights and The force per millimeter was recorded at 50% of the dropped sample.

Example 3

This example illustrates the invention of a mixture comprising chlorinated polyvinyl chloride. The following products are mixed at a temperature of 182.2-187.8 ° C until uniform and made into test plates for testing at 198.9 ° C. All amounts are given in weight ratio.

The Izod impact value is 37.0 cm-kg / cm in the first product, -notch, 81.6 cm-kg / cm in the product 2, -notch and 4.36 cm in the product 3 (control roll). -Kg, / cm-notch.

Example 4

This example shows that the izod impact increases when the average particle size of methacrylate in the additive is in the range of about 0.6 to 0.8 microns compared to small particle sizes of 0.18 to 0.26 microns.

The following uniform PVC predominantly batch is prepared from the following components as described in example 3 (all given amounts are by weight).

The main batch is then mixed together from about 182.2 ° C. to about 187.8 ° C. until a homogeneous mixture is obtained with two different additives made according to US Pat. No. 3,944,631 of A.J. Yu, each having a different average particle size. The products are as follows:

The average particle size of the methacrylate component is from about 0.18 to 0.26 microns.

** The average particle size of the methacrylate component is from about 0.6 to 0.8 microns.

The test plate is made as described in Example 3 and the following Izod impact values are also obtained.

Product 1: 43.5 cm,-kg / cm,-notch

Product 2: 130.6 cm, -kg / cm, -notch

The preceding examples illustrate certain specific features and better specific expressions of the invention and should not be construed in a limited sense. The scope of protection to be obtained is given in the following claims.

Claims (1)

5 to 50% by weight of an effective amount of crosslinked (meth) acrylate, 5 to 35% by weight of crosslinked styrene-acrylonitrile, and non-crosslinked styrene-acrylonitrile. The composition of the vinyl chloride polymer and the impact modifier, characterized in that the impact resistance is improved and the thermal degradation temperature is improved compared to the vinyl chloride polymer by blending ˜90% by weight.