JPH03152147A - Rigid chlorinated vinyl chloride-based resin composition for injection molding - Google Patents

Abstract

PURPOSE:To obtain the title composition excellent, in particular, in molding processability and resistance to heat and impact by incorporating a specific chlorinated vinyl chloride-based resin with an impact resistance improver and a specific bisamide compound. CONSTITUTION:The objective composition can be obtained by incorporating (A) 100 pts.wt. of a chlorinated vinyl chloride-based resin 400-1200 (pref. 600-1000) in average polymerization degree and 62-70 (pref. 62-68)wt.% in chlorine content with (B) 3-15 pts.wt. of an impact resistance improver (pref. chlorinated polyethylene, ABS resin or MBS resin) and (C) 4-20 (pref. 5-15) pts.wt. of a bisamide compound of the formula (R is 7-23C pref. 7-21C alkyl or OH-substituted alkyl; n is 1-10 pref. 1-6) (e.g. methylenebisstearic amide) and, where appropriate, (D) other ingredient(s).

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a hard chlorinated vinyl chloride resin composition for injection molding, particularly having good moldability, heat resistance, and impact resistance.

(Prior art) Hard vinyl chloride resin has excellent mechanical strength, dimensional stability, flame retardancy, weather resistance, chemical resistance, etc., and is suitable for injection molding of joints, flanges, valves, bolts, nuts, containers, etc. Widely used as molded products.

However, hard vinyl chloride resin has the disadvantage that it does not have sufficient heat resistance and may undergo thermal deformation under high temperatures such as boiling water.

In order to improve these drawbacks, chlorinated vinyl chloride resin, which is obtained by post-chlorinating vinyl chloride resin, has been used, but hard chlorinated vinyl chloride resin has problems with moldability (flow characteristics during injection molding). be.

As a method of improving molding processability, there is a method of adding an internal lubricant or a processing aid to chlorinated vinyl chloride resin.

(Question H to be solved by the invention) However, when adding an internal lubricant or processing aid to chlorinated vinyl chloride resin, the moldability improves as the amount added increases, but the heat resistance decreases as the amount added increases. The decrease in the amount of carbon dioxide is significant, and in reality, only a small amount can be added and a sufficient improvement effect cannot be obtained.

The present invention solves the above problems, and its purpose is to provide a hard chlorinated vinyl chloride resin composition for injection molding that has particularly good moldability, heat resistance, and impact resistance. It is in.

(Means for Solving the Problems) The hard vinyl chloride resin composition for injection molding of the present invention has an average degree of polymerization of 400 to 1200 and a chlorine content of 62 to 7.
100 parts by weight of 0% by weight chlorinated vinyl chloride resin, 3 to 15 parts by weight of an impact modifier, -general formula (R-CONH)
Bisamide-based compounds 4 to 20 represented by 1 (CFI) (wherein R is an alkyl group having 7 to 23 carbon atoms or an alkyl group in which any hydrogen thereof is substituted with a hydroxyl group, and n is 1 to 10) parts by weight, thereby achieving the above objective.

In the present invention, the average degree of polymerization is 400 to 1200, preferably 600 to 1000, and the chlorine content is 62 to 70.
Weight percent preferably 62 to 68 weight percent of chlorinated vinyl chloride resin is used. If the average degree of polymerization is less than 400, mechanical strength and impact resistance will deteriorate, and if the average degree of polymerization exceeds 1200, moldability (fluidity during injection molding) and melt gelling properties will deteriorate.

Further, when the chlorine content is less than 62% by weight, the heat resistance is not much different from that of vinyl chloride resin, and conversely, when the chlorine content is more than 70% by weight, thermal decomposition becomes easy.

Note that the average degree of polymerization is measured in accordance with JIS K-6721, and the chlorine content is measured by chlorine weight analysis using an oxygen flask combustion method.

Furthermore, hard as used in the present invention means a chlorinated vinyl chloride resin containing no plasticizer at all, or a chlorinated vinyl chloride resin containing 10% by weight or less of a plasticizer.

As the impact modifier, all those commonly used for chlorinated vinyl chloride resins and vinyl chloride resins can be used. Among them, chlorinated polyethylene, ABS resin, M
BS resin is preferred. The impact modifier is blended in an amount of 3 to 15 parts by weight based on 100 parts by weight of the chlorinated vinyl chloride resin. If the amount is less than 3 parts by weight, the impact resistance will be insufficient, and if the amount is more than 15 parts by weight, there is a risk of a decrease in mechanical strength. is improved, so it is sufficient to add 20 parts by weight or less.

In the bisamide compound represented by the general formula (R-CONH) s (CH3)7, when the number of carbon atoms in R exceeds 23 or when n exceeds 10, the time required for melting (gelling) the resin composition increases. As the length increases, the resin becomes easier to thermally decompose.

The number of carbon atoms in R is preferably 7 to 21, and n is preferably 1 to 6. Such a bisamide compound can be obtained by reacting a fatty acid with an alkylamine when n is 2 or more. Moreover, when n is 1, it can be obtained by reaction of fatty acid amide and formalin.

Examples of such bisamide compounds include methylene bisstearamide, ethylene biscapric acid amide,
Ethylene bislauric acid amide, ethylene bisstearic acid amide, ethylene bisisostearic acid amide,
Examples include ethylene bis-12-hydroxystearamide, ethylene-bis-behenic acid amide, hexamethylene-bis-stearic acid amide, hexamethylene-bis-12-hydroxystearic acid amide, hexamethylene-bis-behenic acid amide, and the like.

These bisamide compounds may be used alone or in combination of two or more, and are blended in an amount of 4 to 20 parts by weight, preferably 5 to 15 parts by weight, per 100 parts by weight of the chlorinated vinyl chloride resin. If the amount is less than 4 parts by weight, the melt viscosity of the resin will not be sufficiently reduced, and if the amount is more than 20 parts by weight, the melt gelation rate of the resin will be slow.

The structure of the hard chlorinated vinyl chloride resin composition for injection molding of the present invention is as described above, but a conventionally known injection molding machine is used to mold a molded article from the compounded composition, and generally a resin compound powder is used. The mixture is kneaded, pelletized, and then supplied to an injection molding machine.

In this case, the resin compound powder contains heat stabilizers, lubricants, processing aids, antistatic agents, ultraviolet absorbers, colorants, fillers, etc. that are generally used in hard chlorinated vinyl chloride resins and vinyl chloride resins. Compounding agents are added as necessary.

(Function) As in the present invention, when a specific chlorinated vinyl chloride resin is blended with an impact strength enhancer in a predetermined range, the impact resistance of the resin is improved, and further, when a specific bisamide compound is added in a predetermined range, the impact resistance of the resin is improved. When blended, the flow characteristics during injection molding are improved without significantly reducing the heat resistance of the resin. Furthermore, the above-mentioned bisamide compound also contributes to improving the impact resistance of the resin.

The reason why the above properties are obtained by blending the above bisamide compounds is not necessarily clear, but the above compound melts due to heating during injection molding and lowers the melt viscosity of the resin. The flow characteristics are improved, and the above compound exists in a solid state in a phase-separated state in the resulting molded product, which is expected to improve impact resistance and not significantly affect heat resistance. be done.

(Example) Examples and comparative examples of the present invention are shown below.

100 parts by weight of chlorinated polyvinyl chloride with an average degree of polymerization of 800 and a chlorine content of 67% by weight, and BT8-1 [[N (MBS resin manufactured by Kureha Chemical Co., Ltd.) as an impact modifier] 7 parts by weight, 2 parts by weight of TVS-8831 (dioctyltin mercapto manufactured by Nitto Kasei Co., Ltd.) as a heat stabilizer, and TVS-88.
13 (1 part by weight of dioctyltin malate manufactured by Nitto Kasei Co., Ltd., 1 part by weight of 18X-0P (composite lubricant manufactured by Hoechst Java Co., Ltd.) as a lubricant, and Metablane P-7 as a processing aid.
00 (acrylic type manufactured by Mitsubishi Rayon Co., Ltd.) and 7 parts by weight of ethylene bisstearic acid amide as a bisamide compound were mixed in a Henschel mixer at 80° C. or lower for 5 minutes to prepare a resin blend powder.

This resin blended powder is processed into a twin-screw kneading extruder at a maximum barrel temperature of 19.
The mixture was extruded into strands at 0°C and immediately cut with a pelletizer to produce a pelleted compound. This pellet-like compound was molded into an injection molding machine (1s manufactured by Toshiba Machine Co., Ltd.).
-850B), injection pressure 1840kg/cj,
Molding temperature 170-180℃, screw rotation speed 60rp
lI, height 450mm x width 900w under conditions of mold temperature 30℃
A plate with a thickness of 3 cm and a thickness of 5 cm was molded.

The filling rate of the resin in this case (complete filling is taken as 100%) was measured. In addition, the molded plates were checked for resin burn, and their moldability, heat resistance, and impact resistance were measured using the following methods. The results are shown in Table 1.

(1) Molding processability The above pellet-like compound was supplied to a Koka-type flow tester, and a load of 100 was applied using a nozzle of 1 mΦ x 10 m.
The flow value (discharge amount), which is an index of moldability, was measured under the conditions of kg/cd and temperature of 190°C.

(2) Heat resistance Using a molded plate with a thickness of 5 cm, the heat distortion temperature (H (IT)), which is an index of heat resistance (according to JIS K-7207,
A load of 18,5 kg/cd) was measured.

(3) Impact resistance Above thickness 3r! JIS K-711 using a molded plate of
1, Charpy impact strength (notched), which is an index of impact resistance, was measured.

Group 1 (Example 1 except that the amount of ethylene bisstearamide as a bisamide compound was changed to 12 parts by weight)
I did the same thing. The results are shown in Table 1.

The same procedure as in Example 1 was carried out except that 7 parts by weight of ethylene bis-12-hydroxystearamide was added as the bisamide compound. The results are shown in Table 1.

The same procedure as in Example 1 was carried out except that 7 parts by weight of ethylene bisbehenic acid amide was added as the bisamide compound. The results are shown in Table 1.

Example 1 was carried out in the same manner as in Example 1, except that 7 parts by weight of hexamethylene bisstearamide was blended as the bisamide compound. The results are shown in Table 1.

Example 1 was carried out in the same manner as in Example 1, except that the amount of ethylene bisstearamide as a bisamide-based compound was changed to 3 parts by weight. The results are shown in Table 1.

Example 1 The same procedure as in Example 1 was carried out, except that 7 parts by weight of conventionally used monostearic acid glyceride was added instead of the bisamide-based compound ethylene bisstearic acid amide. The results are shown in Table 1.

Comparison 11 Impact modifier BT8-1 [[N (M manufactured by Kureha Chemical Co., Ltd.)
Except for changing the blending amount of BS resin to 2 parts by weight.
The same procedure as in Example 1 was carried out. The results are shown in Table 1.

(Effect of the invention) As mentioned above, the chlorinated vinyl chloride resin 10 has an average degree of polymerization of 400 to 1200 and a chlorine content of 62 to 70% by weight.
0 parts by weight, 3 to 15 parts by weight of an impact modifier, and general formula (R-CON) By blending 4 to 20 parts by weight of a bisamide compound represented by an alkyl group in which hydrogen is substituted with a hydroxyl group (n is 1-10), particularly good moldability, heat resistance, and impact resistance can be achieved. A hard chlorinated vinyl chloride resin composition suitable for injection molding is obtained.

Therefore, the hard chlorinated vinyl chloride resin composition for injection molding of the present invention cannot be used as injection molded products such as joints, flanges, valves, bolts, nuts, containers, etc. due to the heat resistance of hard vinyl chloride resins. It is suitable for use in various applications.

Claims (1)

[Claims] 1. 100 parts by weight of a chlorinated vinyl chloride resin with an average degree of polymerization of 400 to 1200 and a chlorine content of 62 to 70% by weight, 3 to 15 parts by weight of an impact modifier, and a compound of the general formula (R-C
ONH)_2(CH_2)_n (However, R has 7 to 7 carbon atoms
23 alkyl group or an alkyl group in which any hydrogen thereof is substituted with a hydroxyl group; n is 1 to 10; ) A hard chlorinated vinyl chloride resin composition for injection molding, comprising 4 to 20 parts by weight of a bisamide compound represented by: