JP2921948B2 - Vinyl chloride copolymer - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a vinyl chloride copolymer excellent in processability and a method for producing the same.

[Problems to be solved by the prior art and the invention]

Although vinyl chloride resin is widely used due to its excellent physical properties, if the processing temperature is increased during molding, hydrogen chloride is generated and the vinyl chloride resin may be decomposed. For this reason, vinyl chloride resin is said to be a resin that is more difficult to mold than polyolefin. For this reason,
Various attempts have been made to improve the moldability of vinyl chloride resins.

The following method is known as a means for improving the moldability of a vinyl chloride resin. Although good molding processability can be obtained by lowering the degree of polymerization of the vinyl chloride resin, it has a disadvantage that thermal stability and impact resistance are reduced. Also,
Low molecular weight methacrylic acid ester-
There is also known a method of improving molding processability by blending a modified resin such as a sterene copolymer or an acrylonihalyl-styrene copolymer. However, many modifiers are required to improve moldability. This method also has the disadvantage that the modified resin bleeds out during long-term use. Furthermore, a method of improving moldability by copolymerizing vinyl chloride and an α-olefin such as ethylene, propylene and butene is known, but has a problem that the heat softening temperature is also lowered. I have.

On the other hand, a composition obtained by mixing a vinyl chloride resin with a polymer plasticizer to impart flexibility is widely used for components such as automobiles, building materials, electricity, and medicine. For example, it is known to blend a polymer plasticizer such as poly-ε-caprolactone with a vinyl chloride resin. However, simply blended poly-ε-caprolactone bleeds out,
It is known that it tends to crystallize in a vinyl chloride resin, and its flexibility and transparency decrease over time.

JP-A-2-103212 also discloses a porous polymer resin obtained by copolymerizing vinyl chloride with an acrylic acid ester of poly-ε-caprolactone, but this resin has a carbonyl derived from an acryloyl group or a methacryloyl group. Therefore, there is a problem that the thermal stability of the vinyl chloride resin is reduced.

Therefore, there is a demand for a vinyl chloride resin having good molding processability, no reduction in physical properties such as thermal stability, impact resistance, and softening temperature, and no bleed-out of additives.

[Means for solving the problem]

The present inventors have intensively studied to solve the above problem. As a result, a vinyl chloride copolymer containing a monomer unit based on an allyl ester of polylactone in a specific ratio has good moldability, and has heat stability, impact resistance, flexibility temperature, etc. The inventors have found that the physical properties are not reduced and that the added polymer does not bleed out, and have completed and proposed the present invention.

That is, the present invention relates to (1) a) a general formula [I] [However, m is 2, 4, or 5, and the average value of n is 5.2 to 271.
It is. And poly-β-propiolactone, poly-δ-
A vinyl chloride copolymer obtained by copolymerizing a monomer containing 0.01 to 50 mol% of an allyl ester of a polylactone selected from valerolactone and poly-ε-caprolactone; and b) 50 to 99.99 mol% of vinyl chloride. is there.

In the general formula [I], n may be 2, 4 or 5, but m is 2 or 5 because of ease of synthesis of the alliester.
It is preferred that It is difficult to synthesize an allyl ester having m = 3.

In the general formula [I], n is an integer of 1 to 500. n
If it exceeds 500, the molecular weight of the macromonomer composed of an allyl ester becomes large, so that there is a disadvantage that the copolymerizability with vinyl chloride is reduced.

The ratio of copolymerizing the allyl ester represented by the general formula [I] and vinyl chloride must be 0.01 to 50 mol% for the former, 50 to 99.99 mol% for the latter, and 0.02 to 25 mol% for the former.
Mol%, the latter being preferably from 75 to 99.98 mol%.

When the amount of the allyl ester represented by the former general formula [I] is too small, the molding processability of the obtained vinyl chloride copolymer is insufficient, and conversely, when the amount is too large, the amount of the obtained vinyl chloride copolymer is reduced. This is not preferable because the heat softening temperature is significantly reduced.

The vinyl chloride copolymer of the present invention generally has a number average molecular weight of 20,000 to 600,000. In particular, the degree of polymerization is preferably in the range of 30,000 to 200,000 from the viewpoint of moldability, thermal stability, impact resistance and the like.

In the copolymerization of the allyl ester represented by the general formula [I] and vinyl chloride, each monomer is copolymerized at random.

The vinyl chloride copolymer of the present invention can be produced by copolymerizing the allyl ester represented by the general formula [I] and vinyl chloride.

The allyl ester represented by the general formula [I] used in the above method is obtained by polymerizing β-propiolactone, δ-valerolactone or ε-caprolactone in the presence of furyl alcohol using a porphyrin aluminum complex as a catalyst. Alternatively, it can be obtained by reacting a polymer comprising the lactone having a hydroxyl group at a terminal with allyl halide.

Copolymerization of vinyl chloride and the allyl ester represented by the general formula (I) includes suspension polymerization, solution polymerization, bulk polymerization,
The polymerization can be carried out by any of emulsion polymerization and precipitation polymerization. The suspension polymerization which is one of suitable polymerization methods will be specifically described below.

In suspension polymerization, radical copolymerization of the allyl ester represented by the above general formula [I] and vinyl chloride is carried out in the presence of an aqueous medium and an oil-soluble polymerization initiator. As described above, the copolymerization ratio of the allyl ester represented by the general formula [I] and vinyl chloride is 0.01 to 50 mol%
And the latter is in the range of 50 to 99.99 mol%.

A monomer known as a polymerizable monomer other than vinyl chloride and the allyl ester represented by the general formula (I), that is,
Physical properties of the vinyl chloride copolymer of the present invention include ethylene, propylene, butene, heptene, acrylic acid, methacrylic acid, methyl acrylate, ethyl acrylate, butyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, etc. Can be copolymerized within a range that does not substantially change, for example, in the range of 0.1 to 5 mol% based on the vinyl chloride monomer.

The amount of the aqueous medium is suitably 0.5 to 3 times the volume ratio of a mixture of vinyl chloride and a monomer such as an allyl ester represented by the above general formula [I].

Oil-soluble polymerization initiators include, for example, lauryl peroxide, benzoyl peroxide, diisopropylperoxydicarbonate, di-sec-butylperoxydicarbonate, di-2-ethylhexylperoxydicarbonate, di-2-ethoxy Ethyl peroxydicarbonate, di-2-methoxyethyl peroxydicarbonate, tert-butylperoxypivalate, tert-butylperoxyneodecanate, di-3-methoxybutylperoxydicarbonate, di-4-tert- Butylcyclohexylperoxydicarbonate, azobisisobutyronitrile, 2,2'-azobis-2,4-dimethylvaleronitrile, 2,2'-azobis-2,4-dimethoxyvaleronitrile, acetylcyclohexyl peroxysulfonate, etc. Radical polymerization initiation of As long, it may be used alone or in combination. The amount of the oil-soluble polymerization initiator to be used is preferably 0.001 to 2 parts by weight based on 100 parts of the monomer mixture.

In suspension polymerization, a dispersant is generally used.
The dispersant may be a partially saponified polyvinyl acetate, methylcellulose, methoxyethylcellulose, hydroxyethylcellulose, a known dispersant such as hydroxypropylcellulose, and further, nonionics such as polyoxyethylene sorbitan fatty acid ester and polyethylene glycol fatty acid ester. A system surfactant may be used in combination. The total amount of the dispersant and the surfactant is preferably 0.01 to 3 parts by weight based on 100 parts of the monomer mixture.

The order of charging the above-mentioned polymerization reaction substrates is not particularly limited, but it is preferable that the allyl ester of the general formula [I] and vinyl chloride are uniformly dissolved before the start of polymerization. For this purpose, a method such as preliminary stirring before the start of polymerization, post-addition of the polymerization initiator, and separate preparation of the mixed solution of the allyl ester of the general formula [I] and vinyl chloride may be appropriately selected.

The polymerization temperature may be any temperature at which the oil-soluble polymerization initiator thermally decomposes, but is generally preferably from 30 to 80 ° C.

Further, in addition to the above-mentioned polymerization reaction substrates, mercapto compounds, disulfide compounds, known chain transfer agents composed of chlorine compounds such as trichloroethylene, hexane, pentane, allyl esters of the general formula (I) such as heptane, etc. A solvent that dissolves may be added.

As the polymerization operation and polymerization conditions, all known methods and conditions are adopted without any limitation.

After the vinyl chloride copolymer produced by the polymerization is dried, it can be put to practical use as it is.

[Action and effect]

As described above, the effect of the vinyl chloride copolymer of the present invention described above will be specifically described.First, regarding processing fluidity, allyl ester of poly-ε-caprolactone is 0.1%.
The vinyl chloride copolymer having a number average molecular weight of 61,000 introduced by mol% is superior to the vinyl chloride homopolymer having a number average molecular weight of 43,000. Also, Vicat softening temperature, impact strength,
The thermal stability is also superior to vinyl chloride homopolymer having a number average molecular weight of 43,000.

The cause of such good processing fluidity is not clear at present, but by copolymerizing an allyl ester represented by the above general formula [I] as a comonomer with vinyl chloride, a vinyl chloride copolymer is obtained. It is considered to reduce intermolecular pseudo-gathering power.

The vinyl chloride copolymer of the present invention is excellent in processing fluidity, softening temperature, impact strength and heat stability, and also has excellent flexibility and transparency because it contains polylactone in a side chain. It can be used for various applications by injection molding or extrusion molding. For example, rigid products such as pipe joints, OA equipment housings, window frames, or
It can be used for any soft products such as soft films / sheets, hoses, tubes, and gaskets.

Example 1 In a 5 liter autoclave, 2 liters of distilled water, 3 g of polyvinyl acetate having a saponification degree of 75%, 1.0 g of tert-butyl peroxyneodecanate, and a number average molecular weight of 7100 (average value of n in the general formula [I]) = 62), 200 g of allyl ester of poly-ε-caprolactone and 800 g of vinyl chloride were charged and polymerized at 58 ° C for 5 hours. The conversion of vinyl chloride was 68%. The product was filtered and dried to obtain uniform white fine particles. The number average molecular weight (n) of this copolymer was 48,000 as measured by standard polystyrene conversion. The copolymer was further purified by precipitation from tetrahydrofuran and acetonitrile. A part of this copolymer was formed into a film, and the infrared absorption spectrum was measured. The result is shown in FIG. Rather, stretching vibration of C-H is in the vicinity of 3,000 cm ^-1, stretching vibration of C = 0 is the 1,720 cm ^-1, stretching vibration of C-Cl was found to be present in 600~700cm ^-1. Also, ¹ H−
The result of measurement of the nuclear magnetic resonance spectrum ( ¹ H-NMR) is shown in FIG. 2 and was found to be based on the following spectrum.

Further, polyvinyl chloride, poly -ε- caprolactone ¹ H-NMR allyl esters of poly -ε- caprolactone than in the polyvinyl chloride copolymer integral curve of 13.1
% By weight (0.13 mol%).

Examples 2 to 10 In a 5 l autoclave, 2 l of distilled water, 3 g of polyvinyl acetate having a saponification degree of 75%, 1 g of tert-butyl peroxy neodecanoate, allyl esters of poly-ε-caprolactone of various molecular weights and vinyl chloride And polymerization was carried out under the conditions shown in Table 1. Thereafter, the product was filtered and dried to obtain uniform white fine particles. The molecular weight of this polymer was measured in the same manner as in Example 1. The results are shown in Table 1.

Example 11 2 l of distilled water, 3 g of polyvinyl acetate having a saponification degree of 75%, 1 g of tert-butyl peroxyneodecanoate, allyl ester of β-propiolactone (number average molecular weight 5,400, a general formula [ Average value of n in I] = 74) 50 g
And 850 g of vinyl chloride, and polymerized at 57 ° C. for 5 hours. The conversion of vinyl chloride was 73%. The product was filtered and dried to obtain uniform white fine particles. The number average molecular weight of this copolymer was 63,000. Further, a part of the copolymer was precipitated and purified from tetrahydrofuran and acetonitrile. A part of this copolymer is formed into a film,
As a result of measuring the infrared absorption spectrum, the stretching vibration of CH was around 3000 cm ⁻¹ , and the stretching vibration of C = 0 was 1720 cm ^−1.
In addition, it was found that C-Cl stretching vibration was present at 600 to 700 cm ^-1 . By performing elemental analysis on this copolymer, β
5.9% by weight of allyl ester of propiolactone (0.0%
(7 mol%).

Examples 12 to 22 Physical properties of the vinyl chloride copolymers produced in Examples 1 to 11 were evaluated as follows. The results are shown in Table 2.

(1) Preparation of a sheet by a hot roll To 100 parts of a vinyl chloride copolymer, 4 parts of a butyltin maleate-based stabilizer (TVS-N-2000E manufactured by Nitto Kasei) were added, and the mixture was heated with a hot roll at 160 ° C for 5 minutes. The mixture was kneaded to prepare a roll sheet having a thickness of 1.1 mm.

(2) Cut the roll sheet of (1) into pellets of about 3 mm square, and use a Koka type flow tester to perform a constant temperature method (180
° C) to evaluate the fluidity.

(3) The roll sheet of (1) was cut into 4 × 2 cm squares, and the thermal stability was evaluated at 190 ° C. using an oven based on JIS-K7212.

(4) Four roll sheets of (1) were stacked and pressed by a hot press (180 ° C., 200 kg / cm ² ) for 7 minutes to produce a 4 mm-thick press sheet. JIS-K7 from this press sheet
A Charpy impact test specimen was prepared based on 111 and the impact resistance was evaluated.

(5) 1.5cm from the 4mm thick pre-sheet prepared in (4)
A square test piece was prepared and measured in accordance with JIS-K7206, and the flexibility temperature was evaluated at a load of 1 kg and a temperature of 0.1 mm penetration.

(6) 1cm from the 4mm thick press sheet prepared in (4)
Square test pieces were prepared, sandwiched between sheets of polystyrene and acrylonitrile-butadiene-styrene copolymer (ABS), and left at 70 ° C. under a load of 300 g for 5 days to test the migration property. Changes in the surface appearance of the polystyrene and ABS sheets were visually observed and evaluated according to the following criteria.

：: No change at all △: Very slight cloudiness X: Cloudy (7) After leaving the test piece used in the test of (6) for 3 months, the change in transparency was visually observed and evaluated according to the following criteria.

：: no change Δ: somewhat reduced transparency ×: significantly reduced transparency Comparative Examples 1 to 3 In a 5 liter autoclave, 2 liters of distilled water, 3 g of polyvinyl acetate having a saponification degree of 75%, tert-butyl peroxyneodeca Noate 1 g, ester of poly-ε-caprolactone and hydroxyethyl methyl methacrylate (number average molecular weight 80
0) 50 g and 950 g of vinyl chloride were charged and polymerized at 60 ° C. for 5 hours. Thereafter, the product was filtered and dried to obtain a copolymer of Comparative Example [1] as uniform white fine particles. The number average molecular weight of this copolymer was 52,000.

Furthermore, vinyl chloride homopolymers [2] (number average molecular weight 43,000) and [3] (number average molecular weight 61,000) were synthesized by a usual polymerization method.

These polymers of [1], [2] and [3] were prepared in Example 12
Roll sheet and press sheet were prepared in the same manner as in Comparative Examples 1 to 22, and their physical properties were measured.
In Table 2. However, the transferability and transparency of the polymer of [3] were determined for a press sheet obtained by kneading 20 parts by weight of poly-ε-caprolactone (number average molecular weight 7100) with 100 parts by weight of the polymer of [3]. Evaluations of (6) and (7) in Examples 12 to 22 were performed.

Comparative Example 4 Example 2 was repeated, except that 13.2 g of the same molar amount (0.077 mol) of 6-hydroxycaproic acid allyl ester was used instead of the allyl ester of poly-ε-caprolactone. Thus, a copolymer of Comparative Example [4] was obtained. The number average molecular weight of this copolymer was 59,000.

A roll sheet and a press sheet were prepared in the same manner as in Examples 12 to 22, and the physical properties of the copolymer were measured.
The results are shown in Table 2 as Comparative Example 4.

[Brief description of the drawings]

1 and 2 show an infrared absorption spectrum and a ¹ H-nuclear magnetic resonance spectrum of the vinyl chloride copolymer obtained in Example 1, respectively.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-55-782 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) C08F 214/06 C08F 218/12

Claims (1)

(57) [Claims] 1. a) General formula [However, m is 2, 4, or 5, and the average value of n is 5.2 to 271.
It is. And poly-β-propiolactone, poly-δ-
A vinyl chloride copolymer obtained by copolymerizing a monomer containing 0.01 to 50 mol% of an allyl ester of polylactone selected from valerolactone and poly-ε-caprolactone, and b) 50 to 99.99 mol% of vinyl chloride.