JP3174126B2 - Method for producing vinyl chloride copolymer composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a vinyl chloride copolymer composition having excellent moldability and heat resistance. More specifically, the present invention relates to a method for producing a vinyl chloride copolymer composition in which a polymer of an aromatic monomer is bonded to a vinyl chloride polymer.

[0002]

BACKGROUND OF THE INVENTION Vinyl chloride resins are widely used due to their excellent physical properties and low cost. However, if the processing temperature is increased during molding processing, hydrogen chloride may be generated and the resin may be decomposed, and it is said that the molding processing is more difficult than the polyolefin-based resin.

[0003] Therefore, various methods have been tried to improve moldability. For example, there is a method in which the molecular weight of the vinyl chloride resin is reduced to improve the fluidity. But,
This method has a problem that heat resistance, thermal stability and impact resistance of the obtained vinyl chloride resin are deteriorated.
In addition, ethylene chloride and alkyl acrylate
There is also a method of copolymerizing monomers such as vinyl ester and vinyl ester to carry out internal plasticization. However, this method also has a disadvantage that thermal stability and heat resistance are reduced.

Also, polystyrene has good fluidity,
Graft polymerization of styrene onto vinyl chloride resin has also been performed. For example, a vinyl chloride resin having a specific polymerization initiating group and a monomer such as styrene, methyl methacrylate, or butyl acrylate are roll-kneaded at 140 to 150 ° C. and polymerized to obtain excellent fluidity. A method for producing a vinyl resin is described in Japanese Patent Publication No. 57-26617. However, this method has a drawback in that the obtained vinyl chloride resin is hardly uniformly melted at the time of molding and the molding is defective, such as burns. In addition, in the presence of a vinyl chloride resin having a polymerization initiating group, a monomer such as styrene and alkyl acrylate and a cross-linkable polyfunctional monomer are subjected to suspension polymerization to provide an excellent matting effect. A method for producing a resin for flexible molding is disclosed in JP-B-63-33762.
No., published in Japanese Unexamined Patent Publication No. However, this method
Since a polyfunctional monomer is used, the polymer becomes a crosslinked polymer and the flowability of the vinyl chloride resin is reduced.

[0005] Therefore, there is a demand for a method for producing a vinyl chloride resin which has good moldability and does not deteriorate in physical properties such as heat resistance.

[0006]

The present inventors have intensively studied to solve the above-mentioned problems. as a result,
By polymerizing an aromatic monomer in the presence of a vinyl chloride polymer having a polymerization initiating group and a chain transfer agent, a vinyl chloride copolymer composition having excellent moldability and heat resistance can be obtained. And came to propose the present invention.

That is, the present invention provides a method for producing an aromatic monomer using a vinyl chloride polymer having a polymerization initiating group obtained by reacting a compound having two or more polymerization initiating groups in one molecule with vinyl chloride. Monomer or an aromatic monomer and a monomer copolymerizable therewith are mixed with 0.01 to 4 parts by weight of a chain transfer agent based on 100 parts by weight of the total amount of the monomer. A method for producing a vinyl chloride copolymer composition, wherein polymerization or copolymerization is carried out in the presence.

In the present invention, the vinyl chloride polymer having a polymerization initiating group is obtained by reacting a compound having two or more polymerization initiating groups in one molecule as a polymerization initiator to polymerize vinyl chloride. Can be. Examples of the above-mentioned polymerization initiating group include a peroxyester group, a diacylperoxy group, an azo group and the like.

As the compound having two or more polymerization initiating groups in one molecule, known compounds can be employed without any limitation. In the present invention, the following compounds are preferably used. Can be.

[0010]

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[0011]

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(In the above formula, k, m and n are positive integers, and preferably each an integer of 1 to 10 in consideration of copolymerizability with vinyl chloride.) If the amount of the compound having two or more polymerization initiating groups is too small, the polymerization of the aromatic monomer described below is unlikely to occur, and if it is too large, the heat resistance of the vinyl chloride-based copolymer composition to be produced is low. In order to reduce the amount, it is preferable to use 0.01 to 10% by weight, more preferably 0.1 to 5% by weight of the total amount with vinyl chloride.

When vinyl chloride is polymerized using the above-mentioned compound having two or more polymerization initiating groups in one molecule, another monomer may be added. As other monomer units,
For example, olefins such as ethylene, propylene, butene and heptene; allyl compounds such as allyl alcohol and allyl chloride; allyl glycidyl methacrylate, methyl methacrylate, ethyl methacrylate and methyl acrylate
Methacrylate or acrylate compounds such as methacrylate, ethyl acrylate, propyl acrylate, butyl acrylate and glycidyl acrylate; maleimide compounds such as N-phenylmaleimide and N-cyclohexylmaleimide; vinyl acetate and propion And vinyl compounds such as vinyl acid. These other monomers copolymerizable with vinyl chloride can be used in a proportion of 0.1 to 10% by weight based on the total amount with vinyl chloride.

The polymerization of vinyl chloride by the reaction of a compound having two or more polymerization initiating groups in one molecule with vinyl chloride can be carried out by a known method using the compound as a polymerization initiator.

The polymerization includes suspension polymerization, emulsion polymerization, solution polymerization,
Known methods such as bulk polymerization can be employed without any limitation. In suspension polymerization and emulsion polymerization, the weight ratio of monomers such as vinyl chloride and a monomer having a polymerization initiating group to an aqueous medium is suitably 0.2 to 2 times.

When performing suspension polymerization, a dispersant is generally used. The dispersant may be any known dispersant such as partially saponified polyvinyl acetate, methylcellulose, methoxyethylcellulose, hydroxyethylcellulose and hydroxypropylcellulose, and furthermore, polyoxyethylene sorbitan. Nonionic surfactants such as fatty acid esters and polyethylene glycol fatty acid esters may be used in combination. The total amount of the dispersant and the surfactant used is preferably 0.001 to 3 parts by weight based on 100 parts by weight of the monomer.

There is no particular restriction on the order of charging the polymerization reaction substrates described above, and preliminary stirring before the start of the polymerization, post-addition of the polymerization initiator, and the like can be appropriately performed.

The polymerization temperature may be a temperature at which the polymerization initiator thermally decomposes, but a temperature at which the polymerization initiator of a compound having two or more polymerization initiators in one molecule is not completely decomposed. is necessary. Therefore, the polymerization temperature is 0 to
80 ° C. is preferred.

Further, the molecular weight can be controlled by adding a known chain transfer agent comprising a mercapto compound and a chlorine compound in addition to the above polymerization reaction substrate.

Thus, a vinyl chloride polymer having a polymerization initiating group can be obtained. In the present invention, the aromatic monomer is polymerized in the presence of the above-obtained vinyl chloride polymer having a polymerization initiating group and a chain transfer agent.

In the present invention, a chain transfer agent is essential. When a chain transfer agent is not used, the degree of polymerization of the aromatic monomer to be block-copolymerized or graft-copolymerized with the vinyl chloride polymer is too high, and the molding processability of the obtained copolymer composition is poor, and However, thermal stability is not sufficient, which is not preferable.

As the above-mentioned chain transfer agent, known compounds can be employed without any limitation. For example, mercaptoethanol,
Mercapto compounds such as mercaptoacetic acid, mercaptopropionic acid, mercaptopropanediol, octylmercaptan and dodecylmercaptan; alkenes such as propylene, butene and hexene; halogen compounds such as trichloroethane, bromoethane and carbon tetrachloride. Can be. The amount of the chain transfer agent to be used must be 0.01 to 4 parts by weight based on 100 parts by weight of a monomer component composed of an aromatic monomer described later or a monomer copolymerizable therewith. It is preferably in the range of 0.05 to 3 parts by weight. When the amount of the chain transfer agent is less than 0.01 part by weight, no improvement in molding processability is observed, and when the amount exceeds 4 parts by weight, heat resistance and thermal stability are not sufficient, which is not preferable.

As the aromatic monomer, a compound having an aromatic ring and a polymerizable double bond in the molecule can be used without any limitation. Specific examples of the aromatic monomer that can be suitably used in the present invention include styrene, vinyltoluene, α-methylstyrene, chlorostyrene, chloromethylstyrene, and vinylnaphthalene.

The amount of these aromatic monomers to be used is not particularly limited. However, considering the fluidity and heat resistance of the resulting vinyl chloride copolymer composition, vinyl chloride having a polymerization initiating group can be used. 1 to 400 with respect to 100 parts by weight of the polymer
Parts by weight, more preferably 5 to 200 parts by weight.

In this polymerization, methyl methacrylate, methyl methacrylate,
Ethyl methacrylate, methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate
Acrylate or methacrylate compounds for improving the compatibility with vinyl chloride polymers such as N-phenylmaleimide, N-cyclohexylmaleimide, N-methylmaleimide, N-ethylmaleimide, N-butylmaleimide, N-butylmaleimide Maleimide compounds for improving heat resistance, such as cyclohexylmaleimide, N-hydroxyphenylmaleimide, N-methoxyphenylmaleimide, N-methylphenylmaleimide, N-chlorophenylmaleimide; It is also possible to copolymerize in the presence of 1 to 100 parts by weight with respect to 100 parts by weight of the monomer.

The polymerization methods include suspension polymerization, emulsion polymerization,
Known methods such as bulk polymerization and solution polymerization can be employed. Among these polymerization methods, suspension polymerization and bulk polymerization are preferably employed in order to improve both the moldability and heat resistance of the obtained vinyl chloride copolymer composition. As the suspension polymerization, the method described in the method for synthesizing a vinyl chloride polymer having a polymerization initiating group described above can be employed as it is. As the bulk polymerization, a method in which a vinyl chloride polymer having a polymerization initiating group is impregnated with an aromatic monomer and then polymerized by heating or irradiation with ultraviolet rays is suitably employed. In addition, at the time of polymerization, it is not necessary to newly add a polymerization initiator. Is also good.

The polymerization temperature must be a temperature at which the polymerization initiating group bonded to the vinyl chloride polymer thermally decomposes, and is generally preferably 50 to 100 ° C.

After polymerization by the above method, the vinyl chloride copolymer composition is dried with hot air or the like for dehydration and demonomerization. Thereafter, the vinyl chloride copolymer composition is used alone, or a resin such as vinyl chloride resin, chlorinated vinyl chloride resin, or ABS is mixed with the vinyl chloride copolymer composition, and tin, lead, calcium, or zinc stabilizer is used; Fillers such as calcium carbonate, gypsum and mica; lubricants such as polyethylene wax, stearic acid ester and acrylate resin; processing aids such as acrylate resin; pigments such as titanium oxide and carbon black; An agent, an impact modifier, an antioxidant, an antistatic agent and the like can be blended and used for injection molding, extrusion molding, and blow molding.

[0029]

As described above, the vinyl chloride copolymer composition thus obtained is composed of an aromatic monomer existing as a single molecular chain and a vinyl chloride polymer in which a polymer mainly composed of an aromatic monomer is block-bonded. It is presumed that the composition is a micro-blended composition with a polymer mainly composed of a group monomer. In addition, the molecular weight of a polymer mainly composed of an aromatic monomer bonded to a vinyl chloride polymer and a polymer mainly composed of an aromatic monomer existing as a single molecular chain is appropriately adjusted by a chain transfer agent. It is estimated that the number average molecular weight is in the range of 1,000 to 100,000. For this reason, the vinyl chloride-based copolymer composition obtained according to the present invention has a property having both excellent fluidity and heat resistance.

The vinyl chloride copolymer composition obtained in the present invention is excellent in moldability and heat resistance, and can be used in various fields such as injection molding, extrusion molding and blow molding. . Especially when used for injection molding, the fluidity during molding is good, so housing for office machines, electrical and electronic parts,
Suitable for forming joints and building materials.

[0031]

The present invention will be described in more detail with reference to the following Examples, which should not be construed as limiting the present invention.

The properties of the resins obtained in the examples were evaluated by the following methods.

(1) Preparation of Sheet by Hot Roll To 100 parts of the vinyl chloride copolymer composition obtained in the present invention, a butyltin maleate-based stabilizer (Titto, manufactured by Nitto Kasei)
VS-N-2000E) 4 parts, and add 160-1
Kneaded for 5 minutes by hot roll at 80 ° C, thickness 1.1m
m sheets were produced.

(2) Fluidity The sheet of (1) was cut into pellets having a size of about 3 mm square, and a constant temperature method (180 ° C., shear stress 1) was performed using a Koka type flow tester.
The shear rate was measured at 0 Kgf / cm ² ).

(3) Thermal stability The roll sheet of (1) is cut into 4 × 2 cm squares, and heated by a gear oven (180 ° C., 2 hours) according to JIS-7212 using an oven. The stability was evaluated.

(4) Heat resistance Four roll sheets of (1) are stacked and hot-pressed (180).
At 50 Kgf / cm ² ) for 5 minutes.
mm press sheet was prepared. From this, a 15 mm square test piece was prepared, and 1 kg was prepared according to JIS K7206.
f, Vicat softening temperature was measured from the temperature at the time of 1 mm penetration.

(5) Tensile strength The tensile test was measured according to JIS K7113.

(6) Injection moldability Evaluation was made based on the surface condition of a molded article when injection molded using Toshiba Machine's IS-100F.

REFERENCE EXAMPLE 1 2000 g of pure water and a saponification degree of 7 were placed in an autoclave having a capacity of 5 L.
3 g of 5% polyvinyl acetate, 10 g of a compound having two or more polymerization initiator groups in one molecule below,

[0040]

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And 1000 g of vinyl chloride.
Polymerization was carried out at 6 ° C. for 6 hours, and the polymer was dehydrated using a centrifuge. The polymerization rate of the vinyl chloride polymer was 70%, and the number average molecular weight (Mn) of the polymer was 40,000 according to the GPC method. This vinyl chloride polymer was purified from tetrahydrofuran and methanol, and ¹ H-N
When the MR was measured, CH based on the vinyl chloride polymer was measured.
₂ (2.0 to 2.3 ppm), CH (4.3 to 4.6 p)
pm) and C (O) OOC (CH ₃ ) ₃ CH ₃ (1.3p
pm).

Reference Example 2 A polymer azo initiator was synthesized by reacting 10 g of azobiscyanopentanoic acid chloride with 10 g of triethylene glycol in the presence of 30 g of trichloroethylene, followed by drying under reduced pressure. To 10 g of this polymer azo initiator, 2000 g of pure water, 3 g of polyvinyl acetate having a saponification degree of 75%, and 1000 g of vinyl chloride were charged into a 5 L autoclave. Next, polymerization was carried out at 65 ° C. for 6 hours, and the polymer was dehydrated using a centrifuge. The polymerization rate of the vinyl chloride polymer was 70%, and the number average molecular weight (Mn) of the polymer was 40,000 according to the GPC method.
The vinyl chloride polymer was purified from tetrahydrofuran and cyclohexane, and the infrared absorption spectrum was observed. As a result, absorption by an ester group was confirmed at 1,735 cm ^-1 .

Reference Example 3 Triethylene glycol 6 was added to 14 g of adipic acid chloride.
g was reacted to obtain an oligomer having an acid chloride group at a terminal. Then, the oligomer was treated with methyl ethyl ketone 3
0 g, 4 g of 30% hydrogen peroxide and 4 g of sodium hydroxide were added and reacted at a low temperature. After the reaction was completed, filtration and washing with water were repeated, and the solvent was evaporated under reduced pressure to obtain a polymer diacyl polymer. Oxide was synthesized. To 15 g of this polymer diacyl peroxide, 2000 g of pure water, 3 g of polyvinyl acetate having a saponification degree of 75%, and 100 g of vinyl chloride
0 g was placed in a 5 L autoclave. Then
Polymerization was carried out at 75 ° C. for 6 hours, and the polymer was dehydrated using a centrifuge. The conversion of the vinyl chloride polymer is 70.
%, And the number average molecular weight (Mn) of this polymer is GP
It was 30,000 according to the C method. This vinyl chloride polymer was purified from tetrahydrofuran and cyclohexane, and its infrared absorption spectrum was observed. As a result, absorption by a diacylperoxy group was confirmed at 1770 cm ^-1 .

Example 1 500 g of the vinyl chloride polymer having a polymerization initiating group of Reference Example 1
300 g of styrene, 5 g of octyl mercaptan, 2000 g of pure water, and 3 g of polyvinyl acetate having a saponification degree of 75% were charged into an autoclave having a capacity of 5 L, and polymerized at 85 ° C. for 5 hours. Thereafter, the polymer was dehydrated and dried using a centrifugal separator to synthesize the vinyl chloride copolymer composition of the present invention.

The analytical values of the obtained vinyl chloride copolymer composition are shown in Table 1. The physical properties are shown in Table 2.

Example 2 The vinyl chloride polymer 500 having a polymerization initiating group of Reference Example 2
g to 300 g of styrene, 50 g of methyl methacrylate,
Octyl mercaptan 5g, pure water 2000g, saponification degree 7
3 g of 5% polyvinyl acetate was charged into an autoclave having a capacity of 5 L, and polymerization was carried out at 80 ° C. for 5 hours.

Thereafter, a vinyl chloride copolymer composition was obtained in the same manner as in Example 1. The analytical values are shown in Table 1, and the physical properties are shown in Table 2.

Example 3 The vinyl chloride polymer 500 having a polymerization initiating group of Reference Example 3
g to 300 g of styrene, 50 g of methyl methacrylate,
Octyl mercaptan 5g, pure water 2000g, saponification degree 7
3 g of 5% polyvinyl acetate was charged into an autoclave having a capacity of 5 L, and polymerization was carried out at 85 ° C. for 5 hours.

Thereafter, a vinyl chloride copolymer composition was obtained in the same manner as in Example 1. The analytical values are shown in Table 1, and the physical properties are shown in Table 2.

COMPARATIVE EXAMPLE 1 A 5 L autoclave was charged with 2000 g of pure water and a saponification degree of 7
3 g of 5% polyvinyl acetate, 1 g of tert-butyl peroxyneodecaneate, and 1000 g of vinyl chloride were charged, and polymerization was performed at 67 ° C. for 5 hours. The conversion of the vinyl chloride polymer was 77%. The number average molecular weight (Mn) of this polymer was 47,000. Table 1 shows the physical properties of this polymer as Comparative Example 1.

Comparative Example 2 500 g of the vinyl chloride polymer of Comparative Example 1 and 500 of styrene
g, pure water 2000g, polyvinyl acetate 3 with a saponification degree of 75%
g, octyl mercaptan 5 g and benzoyl peroxide 2 g were charged into a 5 L autoclave, and 9 g
Polymerization was carried out at 0 ° C. for 5 hours.

Thereafter, a vinyl chloride copolymer composition was obtained in the same manner as in Example 1. The analytical values are shown in Table 1, and the physical properties are shown in Table 2. It was found that when this resin was injection molded, molding defects such as burning of the resin occurred.

[0053]

[Table 1]

[0054]

[Table 2]

Examples 4 to 6 Using the vinyl chloride polymer having a polymerization initiating group of Reference Examples 1 to 3, and under various conditions shown in Table 3, using dodecyl mercaptan as a chain transfer agent, The monomer was polymerized. Table 3 shows the analysis values of the obtained vinyl chloride copolymer composition. Table 4 shows the physical properties of the resin measured in the same manner as in Example 1.

[0056]

[Table 3]

[0057]

[Table 4]

Continuation of the front page (56) References JP-A-54-132695 (JP, A) JP-A-54-29354 (JP, A) JP-A-58-127717 (JP, A) JP-B-38-4494 (JP) , B1) (58) Field surveyed (Int. Cl. ⁷ , DB name) C08F 259/04 C08F 293/00

Claims (1)

(57) [Claims] An aromatic monomer or an aromatic monomer is obtained by using a vinyl chloride polymer having a polymerization initiating group obtained by reacting a compound having two or more polymerization initiating groups in one molecule with vinyl chloride. A mixed monomer comprising a monomer and a monomer copolymerizable therewith is added in an amount of 0.0
A method for producing a vinyl chloride copolymer composition, wherein polymerization or copolymerization is carried out in the presence of 1 to 4 parts by weight of a chain transfer agent.