JPS6215249A - Vinyl chloride resin composition - Google Patents

Abstract

PURPOSE:To provide the titled composition having high transparency, strength and impact resistance and long permissible working time because of short gel time and long thermal decomposition time in working, by compounding a vinyl chloride resin with a vinyl ester-ethylene copolymer having epoxy group or carboxyl group. CONSTITUTION:(A) 100pts.(wt.) of a vinyl chloride resin is compounded with (B) 0.5-20pts., preferably 1-5pts. of a vinyl ester-ethylene copolymer copolymer having epoxy group or carboxyl group. The component B is a polymer having a vinyl ester content of 25-75wt%, preferably 45-65wt% and obtained by introducing 600-50,000 equivalent, preferably 800-15,000 equivalent of epoxy group and carboxyl group under the graft-polymerization condition.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to hard and semi-hard vinyl chloride resin (hereinafter abbreviated as PVC) compositions suitable for sheets, molded products, etc., and particularly to molding processing. The present invention relates to a PVC composition with excellent properties, heat resistance, and impact resistance.

Although PVC is a general-purpose polymer with excellent mechanical properties and economic efficiency, it has the drawback of poor processability in various ways. That is,
The gelation rate is slow, the melt viscosity is high and the fluidity is poor, and the molding process area is narrow because it is easily thermally decomposed. However, PvC
By adding various lubricants, stabilizers, processing aids, etc. prior to processing, the disadvantages of PvC can be improved and the composition of the present invention, which is widely used, is also intended to improve the processability of PvC. It is.

[Conventional technology and problems]

Various polymer processing aids are used for the purpose of improving the moldability of PvC. A typical example is a polymer whose main component is polymethyl methacrylate. However, although this polymer is excellent in accelerating the gelation rate, it has high melt viscosity and poor fluidity.Also, it generates a large amount of heat during kneading, and the time until PVC thermal decomposition is shortened. , the so-called dynamic heat resistance is poor.Furthermore, in terms of physical properties, it does not lower the thermal softening temperature but has the disadvantage of lowering the impact strength.On the other hand, vinyl ester-ethylene copolymer (hereinafter abbreviated as VER) also has the disadvantage of lowering the impact strength of PvC. It is used as a processing aid.Since VER has rubber-like properties, it does not reduce impact resistance, it actually reduces melt viscosity, and it does not deteriorate dynamic heat resistance, so it is suitable for hard calender applications, etc. It is preferably used in applications where the occurrence of air marks in the sheet and dynamic heat resistance are issues. However, it has the disadvantage that it is inferior to the polymethyl methacrylate mentioned above in terms of accelerating the gelation rate. There has been a desire for a PVC composition that has both the gelling speed of a polymethyl methacrylate blend, the fluidity and dynamic heat resistance of a VEE blend, and has excellent physical properties such as impact resistance.

[Means for solving problems]

Under such circumstances, the present inventors have studied various polymer compositions and found that by incorporating VER having an epoxy group or carboxyl group into PVC, it has excellent gelation speed, fluidity, and dynamic heat resistance, and also It was discovered that impact strength could also be improved, and the present invention was completed.

That is, the present invention provides a PvC composition characterized in that 0.5 to 20 parts by weight of VE R containing an epoxy group or carboxyl group is blended with 100 parts by weight of PVC.

In the present invention, the VER used by introducing an epoxy group or a carboxyl group usually has a vinyl ester content of 25 to 7.
5% by weight is used, especially 45 to 65% by weight.
It is preferable to use a pvcl composition which has good transparency, a fast gelation rate, and excellent impact strength.

The VER used here is obtained by copolymerizing vinyl ester and ethylene, and the polymerization method may be any of bulk polymerization, solution polymerization, emulsion polymerization, and suspension polymerization. Vinyl esters include vinyl acetate,
Examples include fatty acid vinyl esters such as vinyl propionate and vinyl laurate, each of which may be used alone or in combination of two or more, with vinyl acetate being particularly preferred.

Epoxy group- or carboxyl group-containing vE used in the present invention
E (hereinafter abbreviated as modified VER) is 600 to 50,000, preferably 800-1 in terms of the epoxy group or carboxyl group equivalent.
Among them, those having an epoxy group or a carboxyl group introduced under graft polymerization conditions are preferred because they have excellent effects.The epoxy group equivalent or carboxyl group equivalent is the equivalent of 1 gram of epoxy group or carboxyl group. It is expressed in grams of resin contained.

Examples of the epoxy group-containing vinyl monomer or carboxyl group-containing vinyl monomer used here include glycidyl acrylate, glycidyl methacrylate, allyl glycidyl ether, methacryl glycidyl ether, acrylic acid,
Examples include methacrylic acid, fumaric acid, maleic acid, maleic anhydride, itaconic acid, crotonic acid, oleic acid, and linoleic acid.

In addition, when introducing an epoxy group or a carboxyl group, if necessary, other vinyl monomers other than the above vinyl monomers, such as fatty acid vinyl esters such as vinyl acetate and vinyl propionate, ethyl acrylate, methyl acrylate, hydroxyethyl Vll! alkyl esters of acrylic acid or methacrylic acid such as acrylate, hydroxypropyl methacrylate, methyl methacrylate, aromatic vinyls such as styrene, vinyl cyanides such as acrylonitrile, etc. They may be used together in an amount of 50 parts by weight or less per 100 parts by weight.

VER of vinyl monomer containing epoxy group or carboxyl group
General polymerization methods such as melt grafting using an extruder or graft polymerization in a solution can be used for introduction into the polymer, but in the case of polymerization methods, for example, it is carried out as follows. That is, an epoxy group- or carboxyl group-containing vinyl monomer is added to vEE in a suspended state, the Mffi body is absorbed into VER particles, and then the temperature is raised to carry out polymerization using a radical initiator. These radical initiators include benzoyl peroxide, azobisisobutyronitrile, t-butylperoxybenzoate, t-butylperoxy(2
-ethylhexanoate), diisopropyl peroxycarbonate, t-butyl peroxypivalate, t-
There are butyl peroxyisopropyl carbonate, t-butyl lauryl peroxide, etc., and the vinyl monomer 1
Polymerization is usually carried out by adding 0.1 to 10 parts by weight per 00 parts by weight. The polymerization temperature varies depending on the radical initiator used, but is generally 60 to 130°C, and the produced modified fVER in a suspended state is separated from water, washed, and dried.

In this case, the amount is usually 0.1-10 parts by weight per 100 parts by weight of anti-blocking agent, such as wax or silicone oil.

PVC used in the present invention is a homopolymer of vinyl chloride and a monomer copolymerizable with vinyl chloride, such as vinyl esters such as vinyl acetate; olefins such as ethylene; acrylic acid, methacrylic acid, and alkyl esters thereof;
Copolymers with vinyl chloride containing vinylidene chloride or the like in an amount of 30% by weight or less, and graft copolymers in which vinyl chloride is added to ethylene-vinyl acetate copolymers, chlorinated polyethylene, and thermoplastic polyurethane. etc. can also be used.

The PVC&[l acid product of the present invention has a modified VER of usually 0.5 to 20 parts by weight, preferably 1 part by weight, per 100 parts by weight of PVC.
-5 parts by weight, it has improved properties; if the modified VER is less than 0.5 parts by weight, the gelation promoting effect cannot be improved, and if it is more than 20 parts by weight, the molded product This is not preferred because it has the disadvantage of lowering the thermal softening temperature.

The PVC composition of the present invention may further contain stabilizers, pigments, ultraviolet absorbers, lubricants, plasticizers, impact modifiers, flame softeners, crosslinking agents, blowing agents, fillers, and other additives as necessary. I can do it.

Molding of the PVC composition of the present invention is carried out by conventional mixing roll processing, calendar processing, extrusion molding, injection molding, etc.

〔Effect of the invention〕

The pvcMl composition of the present invention has a short oxidation time and a long thermal decomposition time at processing temperatures, so it has a wide range of stable processing tolerances, and has good impact resistance while maintaining transparency and mechanical strength. sex is improving. As mentioned above, the ditonity characteristic of conventional processing aids has been solved, and as a result, it is used not only in hard films and sheets made by calendar processing, but also in a wide range of fields such as irregularly extruded building materials and pipes made by extrusion processing. It is useful in

〔Example〕

Next, in order to further clarify the characteristics of the present invention, the present invention will be specifically explained using examples. All percentages other than parts and transparency in Reference Examples, Examples, and Comparative Examples are based on weight. The physical property evaluation methods used in the Examples and Comparative Examples are as follows.

1. Processability of PVC composition 1-1 Gellability Using a Brabender Plastograph (PLV-151), follow the kneading torque curve of the PVC composition under the following conditions to determine the time until the first peak for gelation. It was measured as time (GT), and if the gelation time was less than half that of one without the addition of a processing aid, it was considered to have passed.

Jacket temperature: 190℃ Rotor rotation speed: 3Orpm Sample filling: 9 60g Measured in the same manner as in 1-2 Dynamic heat-resistant gelling property, and under these measurement conditions, the time to the second peak is defined as the decomposition time (DT). If it was 22 minutes or more, there was no practical problem and it was passed.

1-3 Processing Stability Further, as a measure of processing stability, the post-gelation decomposition time was calculated using the following formula. The longer this time is, the longer the allowable time for stable processing of the compound is, and if this time is 22 minutes or more, there is no practical problem and the test was passed.

Decomposition time after gelation - DT-GT (minutes) 1-4 Surface quality of molded product (air mark) With the gap between the two rolls set to 0.3, 100 parts of the PVC composition was heated at 190°C for 5 minutes. After kneading, the rolled sheet was observed and the state of air bubble entrainment was evaluated. If the entrainment of air bubbles is the same or less than that of a formulation without the addition of a processing aid, there is no practical problem, so it was passed.

2. Physical Properties After kneading the PvC composition with two rolls at 190°C for 5 minutes, specimens were prepared using a press molding machine and subjected to the following evaluation physical properties, and each physical property was measured.

2-1 Transparency The light transmittance of a press sheet having a thickness of 1 was measured. If the light transmittance was 85% or more, there would be no practical problem, so it was judged as a pass.

2-2 Heat Softening Performed according to JIS K-6745, softening temperature 60
If the temperature is above ℃, there is no practical problem, so it was considered as a pass.

2-3 Impact resistance It was conducted according to JIS K-6745, and if the Charpy impact value was 18 kg-cra/crA or more, there was no problem in practical use (it was considered to be passed).

Reference Example 1 In a magnetically stirred autoclave with an internal volume of 2β, 160 parts of vinyl acetate, 800 parts of distilled water, 1.6 parts of azobisisobutyronitrile (polymerization catalyst), 1.6 parts of polyvinyl alcohol (dispersant), and Sodium acrylate (dispersant) 0
．． After charging 8 parts of the autoclave, the air in the autoclave was replaced with nitrogen, and ethylene was pressurized at 30°C up to 55 kg/cj.The internal temperature was raised to 65°C, and suspension polymerization was carried out for 9 hours. When the residual ethylene was discharged and the temperature was returned to room temperature and normal pressure, a vinyl acetate-ethylene copolymer (hereinafter abbreviated as VAE) suspension having a vinyl acetate content of 63% was produced. Polyvinyl alcohol (dispersant) is added to this VAE suspension.
Add 0.6 parts of methyl methacrylate, 45 parts of glycidyl methacrylate, and 1.3 parts of benzoyl peroxide (polymerization catalyst), and continue stirring at room temperature for 2 hours to suspend the vinyl monomer and initiator. absorbed into particles. Thereafter, the temperature was raised to 75°C, and polymerization was carried out for 5 hours. After washing the resulting particles, 10 parts of calcium stearate (anti-blocking agent) was added, mixed well, and dried at 50°C for 24 hours to obtain a modified VAE (A) with an epoxy group equivalent of 2234 (7).
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Reference Example 2 Epoxy group f1 was prepared in the same manner as Reference Example 1 except that 45 parts of glycidyl methacrylate was used instead of 45 parts of methyl methacrylate and 20 parts of glycidyl methacrylate.
290 parts of modified VAE (B) of 930 were obtained.

Reference Example 3 Modified VAE (C)31 in the same manner as Reference Example 1 except that 20 parts of methacrylic acid was used instead of 20 parts of glycidyl methacrylate, with a carboxyl group equivalent of 1324 (7).
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Reference Example 4 Modified 1 with an epoxy group equivalent of 2730 was prepared in the same manner as Reference Example 1 except that VAE with a vinyl acetate content of 49% obtained by changing the ethylene saturation pressure to 68 kg/cd at 30°C was used.
383 parts of VAE(D) were obtained.

Reference Example 5 296 parts of modified VAE (E) having a carboxyl group equivalent of 2941 was obtained in the same manner as in Reference Example 1 except that 5 parts of maleic anhydride was used instead of 20 parts of glycidyl methacrylate.

Example 1 100 parts of PVC with a degree of polymerization of 1050, 1.5 parts of octyl mercapto, 1 part of glycerin monostearate, and 4 parts of modified VAE (A) were subjected to a Brabender plastograph to evaluate gelation properties, dynamic heat resistance, and processing stability. Gender was evaluated. Separately, PvC compositions having the same composition were mixed using two kneading rolls, and the surface properties, transparency, softening temperature, and impact resistance of the molded products were evaluated. The results are shown in Table-1.

Example 2 Various evaluations were performed in the same manner as in Example 1, except that the amount of modified VAE (A) added was changed to 8 parts, and the results shown in Table 1 were obtained.

Examples 3-6 Modified VAE (B) instead of modified IVAE (A),
Various evaluations were performed in the same manner as in Example 1 except that (C), (D), or (E) was used, and the results shown in Table 1 were obtained.

Comparative Example 1 Modified VAE (A) with vinyl acetate content of 63%
Various evaluations were performed in the same manner as in Example 1, except that VAE was used, and the results shown in Table 1 were obtained.

Comparative Example 2 Various evaluations were performed in the same manner as in Example 1 except that the addition of modified VAE (A) was omitted, and the results shown in Table 1 were obtained.

Comparative Example 3 Various evaluations were carried out in the same manner as in Example 1, except that a commercially available acrylate processing aid (ethyl acrylate/methyl methacrylate - 10 parts, 790 parts copolymer) was used instead of modified VAE (A). , the results shown in Table 1 were obtained.

Claims (1)

[Claims] Epoxy group- or carboxyl group-containing vinyl ester-ethylene copolymer 0 per 100 parts by weight of vinyl chloride resin
．． A vinyl chloride resin composition, characterized in that it contains 5 to 20 parts by weight.