JP3015452B2 - Vinyl chloride copolymer and method for producing the same - 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. For example, there is a method of lowering the degree of polymerization of the vinyl chloride resin. According to this method, good moldability is obtained, but there is a drawback that thermal stability and impact resistance are reduced. There is also known a method of improving molding processability by blending a modified resin such as a low molecular weight methacrylate-styrene copolymer or an acrylonitrile-styrene copolymer with a vinyl chloride resin. 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 is known in which the moldability is improved by copolymerizing vinyl chloride and α-olefin such as ethylene, propylene and butene. However, there is a problem that the heat softening temperature is 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 parts such as automobiles, building materials, electricity, and medicine. For example, it is known to blend a polymeric plasticizer such as poly-ε-caprolactone into 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 and an acrylic acid ester of poly-ε-caprolactone, but this resin has a carbonyl group 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, it is desired to develop a vinyl chloride resin which has good moldability, does not deteriorate physical properties such as thermal stability, impact resistance and softening temperature, and has 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-based copolymer containing a monomer unit based on an allyl ester of polylactone at a specific ratio has good moldability and has good heat stability, impact resistance, softening temperature, etc. The inventors have found that there is no decrease in physical properties and no bleed-out, and have completed and proposed the present invention.

That is, the present invention provides a compound represented by the general formula [I]: Is a vinyl chloride copolymer having a number average molecular weight of 20,000 to 600,000, containing 0.01 to 50 mol% of a monomer unit represented by the following formula and 50 to 99.99 mol% of a monomer unit based on vinyl chloride.

 In the above general formula [I], R is -R₁OR_Two Indicated by
You. Where R₁Is an alkylene group, hydroxyalkylene
Group or phenylene group, R_TwoIs an alkylene group,
Is 0 or 1. The above alkylene group and hydroxy
The carbon number of the silalkylene group is not particularly limited
Has 2 to 8 carbon atoms from the viewpoint of copolymerizability with vinyl chloride.
Preferably. R in the general formula [I] is specifically
For example, CH_{Two Two}, CH_{Two Three}, CH_{Two Four}, CH_{Two Five},
CH_{Two 6}, CH_{Two 7}, CH_{Two 8}, And the like.

In the general formula [I], m may be 2, 4 or 5, but from the viewpoint of ease of synthesis of an allyl ester which is a monomer giving a monomer unit represented by the general formula [I], m is 2
Or 5 is preferable. 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 the monomer unit represented by the general formula [I] and the monomer unit based on vinyl chloride is 0.01 to 50 mol% for the former,
The latter must be 50-99.99 mol%, the former is 0.02
2525 mol%, the latter being preferably 75-99.98 mol%. If the amount of the monomer unit represented by the general formula [I] is too small, the molding processability of the obtained vinyl chloride-based copolymer is insufficient, and if it is too large, the obtained vinyl chloride-based copolymer is obtained. It is not preferable because the softening temperature of the coalescence is remarkably lowered.

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

The monomer units represented by the general formula [I] and the monomer units based on vinyl chloride are randomly arranged.

In general, the vinyl chloride copolymer of the present invention can be suitably produced by the following method. That is, the general formula [I
I] Allyl ester represented by 0.01 to 50 mol% and vinyl chloride
This is a method of copolymerizing a weight body containing 50 to 99.99 mol%.

The allyl ester represented by the general formula [II] used in the above method can be synthesized using the following allylic alcohol as a starting material. That is, CH ₂ = CHCH ₂ O (C
_{H 2) 2 OH, CH 2} = CHCH 2 O (CH 2) 3 OH, CH 2 = CHCH 2 O (CH 2) 4 O
_{H, CH 2 = CHCH 2 O} (CH 2) 5 OH, CH = CHCH 2 O (CH 2) 6 OH, CH 2 =
CHCH ₂ O (CH ₂ ) ₈ OH, CH ₂ ＝ CHCH ₂ OCH ₂ CH ₂ OCH ₂ CH ₂ OH, CH ₂ ＝ C
HCH ₂ OCH ₂ CH (OH) CH ₂ OH, It can be obtained by polymerizing β-propiorawaton, δ-valerorawaton or ε-caprorawaton in the presence of one or more allylic alcohols such as CH ₂ CHCHCH ₂ OC ₆ H ₄ OH.

Copolymerization of vinyl chloride with the allyl ester represented by the general formula [II] 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 the suspension polymerization, in the presence of an aqueous medium and an oil-soluble polymerization initiator, the radical copolymerization of the allyl ester represented by the general formula [II] and vinyl chloride is carried out by a copolymerization ratio of the ester and vinyl chloride. As mentioned above, the former 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 (II), that is,
Physical properties of the vinyl chloride copolymer of the present invention, including 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 general formula [II].

Examples of the oil-soluble polymerization initiator include lauryl peroxide, benzoyl peroxide, diisopropylperoxydicarbonate, di-sec-butylperoxydicarbonate, di-2-ethylhexylperoxydicarbonate, and di-2-ethoxyethylperoxide. Oxydicarbonate, di-2-methoxyethylperoxydicarbonate, tert-butylperoxypivalate, tert-butylperoxyneodecanate, di-3-methoxybutylperoxydicarbonate, di-4-tert-butyl Cyclohexyl peroxydicarbonate, azobisisobutyronitrile, 2,2'-azobis-2,4-dimethylvaleronitrile, 2,2'-azobis-2,4-dimethoxyvaleronitrile, acetylcyclohexyl peroxysulfonate, etc. A known radical polymerization initiator These may be used alone or in combination. The amount of the oil-soluble polymerization initiator used is 0.001 to 100 parts by weight of the monomer mixture.
2 parts by weight are preferred.

In suspension polymerization, a dispersant is generally used.
The dispersant may be any known dispersant such as partially saponified polyvinyl acetate, methylcellulose, methoxyethylcellulose, hydroxyethylcellulose, 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 used is preferably 0.01 to 3 parts by weight based on 100 parts by weight 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 [II] and vinyl chloride are uniformly dissolved before the start of polymerization. For this purpose, a method such as preliminary stirring before the start of the polymerization, post-addition of the polymerization initiator, and separate preparation of the mixed solution of the allyl ester of the general formula [II] 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.

Furthermore, in addition to the above-mentioned polymerization reaction substrate, a known chain transfer agent comprising a mercapto compound, a disulfide compound, a chlorine compound such as trichloroethylene, or an allyl ester of the above-mentioned general formula [II] such as hexane, pentane or heptane may be used. A solvent that dissolves may be added.

As the polymerization operation and polymerization conditions, known methods and conditions are employed 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, the allyl ester of poly-ε-caprolactone is 0.11%.
The vinyl chloride copolymer having a number average molecular weight of 60,000 and having a mole average molecular weight of 43,000 is superior to the vinyl chloride homopolymer having a number average molecular weight of 43,000. Also, the 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 [II] as a comonomer with vinyl chloride, a vinyl chloride copolymer can be obtained. It is considered to reduce intermolecular pseudo-gathering power.

INDUSTRIAL APPLICABILITY The vinyl chloride copolymer of the present invention is not only excellent in processing fluidity, bicut softening temperature, impact strength and heat stability, but also has excellent flexibility and transparency because it contains polylactone in the side chain. It can be used for various applications by injection molding or extrusion molding. For example, it can be used for any of hard products such as pipe joints, OA equipment housings, window frames, and the like, and soft products such as soft films, sheets, hoses, tubes, and gaskets.

Example 1 Distilled water 2, saponification degree 75 in an autoclave having a capacity of 5
% Polyvinyl acetate 3 g, tert-butyl peroxyneodecanate 1.0 g, number average molecular weight 7,900 (the above-mentioned general formula [II]
In the above, 200 g of allyl ester of poly-ε-caprolactone (n = 68) and 800 g of vinyl chloride were charged and polymerized at 60 ° 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.
Shown in the figure. The stretching vibration of CH is 3,000cm ^-1
Near, stretching vibration of C = O is a 1,720 cm ^-1, stretching vibration of C-C was found to be present in 600~700cm ^-1. Further, it was found that shows the results of measurement of ¹ H- nuclear magnetic resonance spectrum ⁽¹ H-NMR) in Figure 2 is based on the spectrum as follows.

Further, a polyvinyl chloride, this polyvinyl chloride copolymer from an integral curve of ¹ H-NMR of poly -ε- caprolactone poly -ε- caprolactone allyl ester 12.5
% By weight (0.12 mol%).

Examples 2-14 Distilled water 2 in an autoclave of easy 5 and saponification degree 75%
Of vinyl acetate, 1 g of tert-butyl peroxy neodecanoate, allyl esters of poly-ε-caprolactone of various molecular weights and vinyl chloride were charged, and polymerization was carried out under the conditions shown in Table 1. Thereafter, the product was filtered. By drying, uniform white fine particles were obtained. The molecular weight of this polymer was measured in the same manner as in Example 1. The results are shown in Table 1.

Example 15 Distilled water 2 in a 5 volume autoclave, saponification degree 75%
3 g of polyvinyl acetate, 1 g of tert-butyl peroxy neodecanoate, 300 g (number average molecular weight 332, n = 3) and 700 g of vinyl chloride were charged and polymerized at 60 ° C. for 5 hours. The conversion of vinyl chloride is 63
%Met. Filter the product. By drying, uniform white fine particles were obtained. Further, a part of the copolymer was precipitated and purified from tetrahydrofuran and acetonitrile.
A part of this copolymer was filmed, and the infrared absorption spectrum thereof was measured. As a result, the stretching vibration of -OH was 3,200.
~ 3,600cm ^-1 , the stretching vibration of CH around 3,000cm ^-1
The stretching vibration of C = O is 1720cm ^-1 and the stretching vibration of C-C is
It was found to be at 600-700 cm ^-1 . Further, elemental analysis of this copolymer revealed that 23.6% by weight (7.1 mol%) of the allyl ester of β-propiorawatone was copolymerized. The number average molecular weight of this copolymer is 41,000 (standard polystyrene conversion by GPC)
Met.

Example 16 Distilled water 2 in a 5 volume autoclave, saponification degree 75%
3 g of polyvinyl acetate, 1 g of tert-butyl peroxy neodecanoate, 200 g (number average molecular weight 1,100, n = 10) and 800 g of vinyl chloride were charged and polymerized at 60 ° C. for 5 hours. The copolymerization ratio of vinyl chloride was 65%. Filter the product. By drying
Uniform white fine particles were obtained. Further, a part of the copolymer was precipitated and purified from tetrahydrofuran and acetonitrile. A part of this copolymer was filmed, and its infrared absorption spectrum was measured. As a result, the stretching vibration of -OH was 3,20.
At 0-3,600 cm ^-1 , stretching vibration of CH is around 3,000 cm ^-1 , stretching vibration of C の O is at 1,720 cm ^-1 , and stretching vibration of CC is at 600-700 cm ^-1 . I understand. Also,
The copolymer was subjected to elemental analysis to find that the allyl ester of δ-valerolactone was 12.1% by weight (11.1 mol%).
The copolymer was found to be copolymerized. The number average molecular weight of this copolymer was 44,000 (standard polystyrene conversion by GPC).

Examples 17 to 32 Physical properties of the vinyl chloride copolymers produced in Examples 1 to 16 were evaluated as follows. The results are shown in Table 2.

(1) Preparation of a sheet by a hot roll To 100 parts by weight of a vinyl chloride copolymer, 4 parts by weight of a butyltin malate-based stabilizer (TVS-N-2000E manufactured by Nitto Kasei) were added, and this was heated with a 160 ° C hot roll. Knead for 5 minutes,
A roll sheet having a thickness of 1.1 mm was produced.

(2) Cut the roll sheet of (1) into a pellet 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 at 190 ° C. was evaluated using an oven based on JIS-K7212.

(4) Four roll sheets of (1) were stacked and hot-pressed (180 ° C., 50 kg / cm ² ) for 7 minutes to produce a 4 mm-thick press sheet. From this press sheet, a Charpy impact test specimen was prepared based on JIS-K7111, and the impact resistance was evaluated.

(5) From the 4mm-thick press sheet prepared in (4),
A test piece of 5 cm square was prepared and measured according to JIS-K7206, and a 1 kg weight was applied, and a vicat softening temperature at 0.1 mm penetration was measured.

(6) From the 4mm-thick press sheet prepared in (4),
A cm square test piece was prepared, sandwiched between sheets of polystyrene and an 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 state of the polystyrene and ABS sheets were visually observed and evaluated according to the following criteria.

：: No change at all △: Very slight cloudiness ×: Cloudiness (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 at all △: Transparency decreased somewhat ×: Transparency decreased considerably Comparative Examples 1 to 5 Distilled water 2 in a 5 volume autoclave, saponification degree 75%
3 g of polyvinyl acetate, 1 g of tert-butyl peroxyneodecanoate, ester of poly-ε-caprolactone and hydroxyethyl methyl methacrylate (number average molecular weight
800) 50 g and vinyl chloride 950 g were charged and polymerized at 60 ° C. for 5 hours. Thereafter, the product was filtered. By drying, the copolymer of Comparative Example [I] was obtained 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 17
In the same manner as in Comparative Examples 1 to 32, a roll sheet and a press sheet were prepared, and their physical properties were measured.
And Further, poly-ε-caprolactone (number average molecular weight 7100) was added to 100 parts by weight of the polymer of [2] and [3].
10 parts by weight were kneaded and evaluated in the same manner as in Examples 17 to 32. The results are shown in Table 2 as Comparative Examples 4 and 5.

[Brief description of the drawings]

1 and 2 are infrared absorption spectra of the vinyl chloride copolymer obtained in Example 1, respectively. And ¹ H-nuclear magnetic resonance spectrum.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-55-782 (JP, A) JP-A-3-157468 (JP, A) JP-A-60-120736 (JP, A) JP-A-2- 103212 (JP, A) JP-A-56-81328 (JP, A) JP-A-4-15207 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C08F 214/06 C08F 216 / 14-216/20

Claims (2)

(57) [Claims] (1) General formula A vinyl chloride copolymer having a number average molecular weight of 20,000 to 600,000, comprising 0.01 to 50 mol% of a monomer unit represented by the following formula and 50 to 99.99 mol% of a monomer unit based on vinyl chloride. 2. The general formula Allyl ester represented by 0.01 to 50 mol% and vinyl chloride
The method for producing a vinyl chloride copolymer according to claim 1, wherein a monomer containing 50 to 99.99 mol% is copolymerized.