KR100341868B1 - Unplasticised Polyvinyl- chloride with Impact modifier - Google Patents

Abstract

In hard vinyl chloride resins using impact modifiers, compound stabilizers, lubricants, processing aids and fillers as additives, chlorinated polyethylene (CPE) and polymethyl methacrylate-butadiene-styrene ( Poly methyl methacrylate Butadien Styrene (MBS system) is used in combination of 8 to 12 parts by weight, but CPE-based: MBS-based addition ratio of 5: 5 to 7: 3 by maintaining the excellent tensile strength of the hard vinyl chloride resin at low temperature An invention for providing a hard vinyl chloride resin molded article having excellent impact strength and low extrusion resistance in an extrusion process.

Description

Unplasticised Polyvinyl chloride with Impact modifier

The present invention relates to a hard vinyl chloride molded article containing an impact modifier.

The most widely used resins in the industrial field can be divided into olefin resins, polyesters, vinyl chloride resins, and polystyrenes. Especially, polyvinyl chloride resins have excellent compatibility with compounds such as plasticizers and reinforcing agents. It is a resin that is attracting attention because it can be modified.

In particular, vinyl chloride resin has strong chemical resistance to inorganic acids, alkalis, oils, etc., and does not cause rust in seawater and corrosive soils. It is also a toxic and odorless material that is hygienic and light in weight, making it easy to handle and transport. It is not only easy to use but also easy to join and repair, so it is most commonly used for thermoplastic water pipes, window frames, plastic panels and plastic containers.

However, hard vinyl chloride resin can not be used unless it is modified from the initial stage of synthesis because it is easily pyrolyzed at a normal processing temperature, and has a disadvantage of being unsuitable in an environment in which strong internal and external forces work due to low low-temperature impact strength compared to steel.

Therefore, the vinyl chloride resin is compounded with various kinds of additives including impact modifiers according to the purpose of use, and the final physical properties can be greatly changed depending on the technology, and the compounding technology together with the comprehensive technology of polymer raw materials It plays an essential role in making this good product.

Particularly, in order to reinforce the impact resistance, impacts such as chlorinated polyethylene (hereinafter referred to as CPE), polymethyl methacrylate-butadiene-styrene (hereinafter referred to as MBS), acrylic, etc. Impact modifiers have been used, and they have advantages and disadvantages in production conditions and product properties in terms of gelation properties, impact strength, Weber extrusion processability, Charpy impact strength, tensile strength, weather resistance, and the like.

Acrylic impact modifiers are suitable for plastic window profiles that require long-term weather resistance, but there are many differences in molding structure in ordinary plastic pipes, plastic panels and plastic containers, which are not suitable for the purposes of the present invention.

MBS-based impact modifier was able to exhibit a strong resistance to low-temperature impact, while maintaining the tensile strength by the dispersion of the rubber-based components as shown in FIG.

MBS-based impact modifiers maintain high tensile strength and impart impact resistance, but have a problem in that the resistance to sunlight is bad and the extrusion resistance (torque) increases in the extruder.

In addition, hard vinyl chloride is usually thermally decomposed at the processing temperature, so a stabilizer is added in the case of water pipe manufacturing.In the case of using a non-toxic non-lead stabilizer such as drinking water piping, the extrusion resistance is high. Impact modifiers could not be used.

Therefore, CPE-based impact modifiers have been added that have excellent affinity with vinyl chloride resins, have an effect of reducing extrusion resistance during extrusion, and have a high effect in preventing cuts from being broken when cutting molded products into unit lengths. .

CPE-based impact modifiers have a remarkable effect in improving weather resistance because they have a strong resistance to sunlight, and as shown in FIG. 2, the CPE-based impact modifiers have an effect of reducing extrusion resistance due to excellent affinity between CPE-based impact modifiers and vinyl chloride resins. It has a high effect in preventing the cutting surface from being broken when cutting the molded product into unit length.

Such CPE is commonly used to add 6 to 8 parts by weight of the impact resistant PVC pipe formulation in the United States.

However, when a large amount of CPE system is used, the flow is not smooth and expensive, so it has to be used for extremely limited use. When using only CPE-based impact reinforcing agent, low-temperature impact strength is lowered. There is a problem of deformation and fracture over time because the tensile strength drops sharply by using a large amount.

Accordingly, the present invention is to solve the above problems, to provide a hard vinyl chloride resin excellent in extrusion resistance, low temperature impact strength and weather resistance.

1 is a transmission electron microscope photograph of a 10,000-fold magnification of a hard vinyl chloride resin containing an MBS-based impact modifier.

Figure 2 is a transmission electron micrograph of a 10,000 times magnification of a hard vinyl chloride resin containing a CPE-based impact modifier

Figure 3 is a transmission electron micrograph of a 10,000 times magnification of a hard vinyl chloride resin containing MBS-based and CPE-based impact modifiers in the composition ratio of the present invention

In order to achieve the above object, in a hard vinyl chloride resin containing an impact modifier, chlorinated polyethylene based (Chlorinated Polyethylene, CPE based) and polymethyl methacrylate-butadiene-styrene as an impact modifier with respect to 100 parts by weight of the vinyl chloride resin Use 8 to 12 parts by weight in combination of poly methyl methacrylate Butadien Styrene (MBS), but add CPE-based: MBS-based ratio of 5: 5 to 7: 3. 2.5 to 3.5 parts by weight, and stearic acid and polyethylene wax 0.3 to 0.6 parts by weight as a lubricant.

To this end, the present inventors have repeatedly conducted a number of experiments, and in using impact modifiers that must be added in the processing of impact-resistant hard vinyl chloride resins, to complement the disadvantages of each other while maximizing the advantages of the CPE and MBS system. I could figure out a possible combination.

3 is a case in which the CPE-based and MBS-based impact modifiers are added as a composition ratio according to the present invention, and the irregularity formed by the excellent affinity between the CPE-based impact modifier and the vinyl chloride resin, and between the MBS-based impact modifier and the vinyl chloride resin. Due to the mixed shape of the heterogeneous shape formed, it forms a more stable dispersion form when only the CPE-based or MBS-based impact reinforcing agent is used, and thus maintains high tensile strength due to the structural characteristic of improving impact resistance against external impacts. It is possible to produce hard vinyl chloride resin with much higher low temperature impact strength.

However, the addition amount of the impact modifier mixture is suitable for 8 to 12 parts by weight based on 100 parts by weight of vinyl chloride resin, when used in less than 8 parts by weight has an effect of reducing the extrusion resistance during extrusion, but does not improve the impact strength, There is a problem that the weather resistance is not improved due to the lack of resistance to sunlight, and when used in excess of 12 parts by weight, the flow in the molding machine is not smooth, the appearance is poor, and the additive including the impact modifier is the surface of the vinyl chloride resin Problem arises.

In particular, the composition ratio of the CPE system and the MBS system is a major factor controlling the balance between the extrusion strength, the low temperature impact strength, and the weather resistance, and the addition ratio of the CPE system: MBS system is preferably 5: 5 to 7: 3.

At this time, when the ratio is added higher than 7: 3 and the MBS ratio is lowered, the impact strength is increased, but the tensile strength is sharply lowered. When the ratio is added at a lower ratio than 5: 5, the tensile strength is increased. However, productivity is low due to high extrusion resistance.

In addition to the impact modifier, various types of additives such as complex stabilizers, lubricants, processing aids, and fillers are added to the hard vinyl chloride resin molded articles, and lead-free stabilizers such as lead or tin are used as stabilizers.

Lead-based stabilizers reduce extrusion resistance compared to non-lead stabilizers, but lead-free stabilizers should be used for water pipes that come in direct contact with drinking water, and used for non-drinking water products such as plastic sewers, panels and containers. In case of using lead-based stabilizer and non-lead-based stabilizer, the ratio of CPE-based: MBS-based is lowered in the range of 5: 5-7: 3, and the ratio of MBS-based is used. To facilitate the flow of the compound.

Lead stabilizers include Tribasic Laed Sulphate Monohydrous, Tribasic LaedStearate, and Lead Stearate, which can be used with MBS impact modifiers due to their high activity.

It is preferable to add 2.5 to 3.5 parts by weight of the stabilizer, but when used in less than 2.5, there is a problem such as resin carbonization, when exceeding 3.5, problems such as blooming (blooming) occurs.

In the lubricant, in addition to the external lubricant such as polyethylene wax, the internal lubricant stearic acid may be used. When the ratio of the CPE system is higher than the MBS system, the polyethylene wax which is the external lubricant is applied slightly more than the internal lubricant stearic acid.

In particular, in the case of hard vinyl chloride resin for drinking water pipes to which a lead-free stabilizer is added, CPE-based: MBS-based impact modifiers are added in a ratio of 6: 4 to 7: 3, and polyethylene wax and stearic acid are 6: 4 to 7: 3 It is preferable to use.

On the other hand, in the case of hard vinyl chloride resin for non-drinking plastic sewer pipes, panels and containers to which lead-based stabilizers are added, CPE-based: MBS-based impact modifiers are added at a ratio of 5: 5 to 6: 4, and polyethylene wax and stearic acid are added. Preference is given to using 5: 5 to 6: 4.

At this time, the addition amount of the lubricant is preferably 0.3 to 0.6 parts by weight, but when used less than 0.3, there is a problem such as non-uniformity of the shape, and when it exceeds 0.6, there is a problem such as gelling.

The processing aid is an additive used in the processing of hard vinyl chloride resins, and it is a melting promoter (Flux Promoter) because it accelerates the work of melting powder-shaped raw materials into the molten phase.

At this time, the addition amount of the processing aid is preferably 1 to 3 parts by weight, but when used less than 1 part by weight, there is no improvement effect of the promotion of melting, and it is an expensive additive to use more than 3 parts by weight, and the power consumption of the motor during processing The extrusion resistance increases because of the increase.

Fillers are used to prevent the hardening of hard vinyl chloride resins, to maintain accurate dimensions and shapes during extrusion, or to reduce manufacturing costs.

Calcium carbonate (CaCO ₃ ) is used as the filler, and the surface of hard coal is coated as a lubricant such as stearic acid.

Such surface-treated fillers are easily mixed with other raw materials and prevent the physical properties such as tensile strength and modulus from being badly degraded.

When the added amount of the filler is less than 3 parts by weight, there is no filling effect, and when it is 15 parts by weight or more, the impact strength is significantly lowered.

Hereinafter, described in detail with reference to a preferred embodiment of the present invention.

Example 1

The raw materials were mixed according to the blending ratios below, and then blended in a supermixer at 120 ° C. for about 15 minutes and extruded in an extruder to prepare a molded article. The extrusion resistance value and tensile strength were measured, and a low temperature impact test was performed. Table 1 Shown in

-Compounding ratio

100 parts by weight of vinyl chloride resin (polymerization degree: K-60, Hanwha Corporation (P-1000))

CPE-based impact modifier (Dow Chemical, CPE-3615) 5 parts by weight

MBS impact modifier (LG Chemical (MB-830)) 5 parts by weight

3 parts by weight of composite stabilizer

0.3 parts by weight of polyethylene wax

0.2 part by weight of stearic acid

5 parts by weight of filler (Omia, T-1)

Processing aid (Kaneka, PA-30) 2 parts by weight

Example 2

According to the same apparatus and method as in Example 1 to produce a molded article by extrusion molding, according to the following blending ratio, the extrusion resistance value and tensile strength was measured and the low temperature impact test was carried out and the results with Example 1 Table 1 shows.

-Compounding ratio

100 parts by weight of vinyl chloride resin (polymerization degree: K-60, Hanwha Corporation (P-1000))

CPE-based impact modifier (Dow Chemical, CPE-3615) 6 parts by weight

MBS impact modifier (LG Chemical (MB-830)) 4 parts by weight

3 parts by weight of composite stabilizer

0.3 parts by weight of polyethylene wax

0.2 part by weight of stearic acid

5 parts by weight of filler (Omia, T-1)

Processing aid (Kaneka, PA-30) 2 parts by weight

Example 3

According to the same apparatus and method as in Example 1 to produce a molded article by extrusion molding, according to the following blending ratio, the extrusion resistance value and tensile strength was measured and the low temperature impact test was carried out and the results with Example 1 Table 1 shows.

-Compounding ratio

100 parts by weight of vinyl chloride resin (polymerization degree: K-60, Hanwha Corporation (P-1000))

CPE-based impact modifier (Dow Chemical, CPE-3615) 7 parts by weight

MBS impact modifier (LG Chemical (MB-830)) 3 parts by weight

3 parts by weight of composite stabilizer

0.3 parts by weight of polyethylene wax

0.2 part by weight of stearic acid

5 parts by weight of filler (Omia, T-1)

Processing aid (Kaneka, PA-30) 2 parts by weight

Comparative Example 1

According to the same apparatus and method as in Example 1 to produce a molded article by extrusion molding, according to the following blending ratio, the extrusion resistance value and tensile strength was measured and the low temperature impact test was carried out and the results with Example 1 Table 1 shows.

-Compounding ratio

100 parts by weight of vinyl chloride resin (polymerization degree: K-60, Hanwha Corporation (P-1000))

10 parts by weight of MBS impact modifier (LG Chemical (MB-830))

3 parts by weight of composite stabilizer

0.3 parts by weight of polyethylene wax

0.2 part by weight of stearic acid

5 parts by weight of filler (Omia, T-1)

Processing aid (Kaneka, PA-30) 2 parts by weight

Comparative Example 2

According to the same apparatus and method as in Example 1 to produce a molded article by extrusion molding, according to the following blending ratio, the extrusion resistance value and tensile strength was measured and the low temperature impact test was carried out and the results with Example 1 Table 1 shows.

-Compounding ratio

100 parts by weight of vinyl chloride resin (polymerization degree: K-60, Hanwha Corporation (P-1000))

10 parts by weight of CPE impact modifier (Dow Chemical, CPE-3615)

3 parts by weight of composite stabilizer

0.3 parts by weight of polyethylene wax

0.2 part by weight of stearic acid

5 parts by weight of filler (Omia, T-1)

Processing aid (Kaneka, PA-30) 2 parts by weight

Comparative Example 3

According to the same apparatus and method as in Example 1 to produce a molded article by extrusion molding, according to the following blending ratio, the extrusion resistance value and tensile strength was measured and the low temperature impact test was carried out and the results with Example 1 Table 1 shows.

-Compounding ratio

100 parts by weight of vinyl chloride resin (polymerization degree: K-60, Hanwha Corporation (P-1000))

CPE-based impact modifier (Dow Chemical, CPE-3615) 7 parts by weight

MBS impact modifier (LG Chemical (MB-830)) 7 parts by weight

3 parts by weight of composite stabilizer

0.3 parts by weight of polyethylene wax

0.2 part by weight of stearic acid

5 parts by weight of filler (Omia, T-1)

Processing aid (Kaneka, PA-30) 2 parts by weight

Comparative Example 4

According to the same apparatus and method as in Example 1 to produce a molded article by extrusion molding, according to the following blending ratio, the extrusion resistance value and tensile strength was measured and the low temperature impact test was carried out and the results with Example 1 Table 1 shows.

-Compounding ratio

100 parts by weight of vinyl chloride resin (polymerization degree: K-60, Hanwha Corporation (P-1000))

CPE-based impact modifier (Dow Chemical, CPE-3615) 3 parts by weight

MBS impact modifier (LG Chemical (MB-830)) 3 parts by weight

3 parts by weight of composite stabilizer

0.3 parts by weight of polyethylene wax

0.2 part by weight of stearic acid

5 parts by weight of filler (Omia, T-1)

Processing aid (Kaneka, PA-30) 2 parts by weight

-Extrusion resistance

The magnitude of the extrusion resistance (torque) on the twin screw extruder was measured, and the extrusion resistance was shown at the comparison rate. malt

-Tensile strength, low temperature impact strength

Low temperature impact strength test and tensile strength test were performed according to the impact resistance test method (KS M 3401). After leaving the sample at 0 ± 2 ° C for at least 60 minutes, the weight is heavier than the worst condition, namely the test specification, and the shape of the weight is determined by using a conical triangular weight to vary the weight and drop height of each weight. The results of experiments after varying the gravitational potential energy (GPE) are shown.

The reaction conditions prepared in the same manner as in Examples 1 to 3 and Comparative Examples 1 to 4 and the results measured by the above test methods are as shown in Table 1, and according to the method of the present invention In the case of Examples 1 to 3 in which the addition ratio of CPE to MBS is 5: 5 to 7: 3 and the addition amount is 8 to 12 parts by weight, the comparative example using only the CPE-based impact modifier in the extrusion molding process The result is almost the same level as 2, and the tensile strength is similar to that of Comparative Example 1 using only the MBS-based impact modifier, while the low-temperature impact strength of Comparative Example 1 using the MBS-based alone, CPE Comparative Example 2 using the system alone, the content of the impact modifier was found to be similar to Comparative Example 3 exceeding 14 parts by weight, but it can be seen that the improved by more than 40% compared to Comparative Example 4 less than 6 parts by weight. have.

This is believed to be due to the combination of complementing each other's disadvantages while maximizing each other's advantages by the appropriate combination of CPE and MBS system.

Therefore, the parameters that determine the impact strength of the polymer material may include the structure and orientation of the polymer, but it is better to design a mixture of different types of impact modifiers through the above examples to improve the ductility of the hard vinyl chloride resin. Able to know.

As described above, the present invention is a preferred invention for providing a hard vinyl chloride resin molded article having excellent low temperature impact strength and low extrusion resistance in an extrusion molding process while maintaining the excellent tensile strength of the hard vinyl chloride resin.

Although the present invention has been described with reference to one embodiment, this is merely exemplary, and it will be understood by those skilled in the art that various modifications and equivalent other embodiments are possible.

Claims (3)

delete Chlorinated Polyethylene (CPE) and Polymethyl methacrylate-Butadiene-Styrene (MBS) are used as impact modifiers, and lead-free complex stabilizers are used as composite stabilizers. In a hard vinyl chloride resin for extrusion processing comprising a mixture of polyethylene wax and stearic acid as a lubricant and containing a processing aid and a filler, 8 to 12 by combining chlorinated polyethylene (CPE) and polymethyl methacrylate-butadiene-styrene (MBS) as an impact modifier for 100 parts by weight of vinyl chloride resin By weight, CPE-based: MBS-based impact modifier is added in a ratio of 6: 4 to 7: 3, non-lead-based stabilizer is used as a compound stabilizer, polyethylene wax and stearic acid as a lubricant 6: 4 to 7: 3 Hard vinyl chloride resin containing an impact modifier, characterized in that used. delete