JPS5839454B2 - Vinyl chloride resin composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a vinyl chloride resin composition having good transparency and processability.

More specifically, the present invention relates to a vinyl chloride resin composition containing a copolymer containing alkyl methacrylate, dialkyl itaconate, and alkyl acrylate as essential components, and a processing aid made of an alkyl methacrylate polymer.

Vinyl chloride resins are widely used due to their excellent physical and chemical properties, but they have various problems such as a processing temperature close to the thermal decomposition temperature and a narrow molding area, as well as a slow gelation rate. There are processing problems.

It is well known that these drawbacks can be solved to some extent by adding plasticizers, but addition of plasticizers not only causes new problems such as volatilization and escape of the plasticizer, but also affects the mechanical properties of the molded product. There are drawbacks such as lowering the

On the other hand, certain copolymers that are compatible with vinyl chloride resins are used to smooth the surface of molded products, speed up gelation, and improve processability to enable deep drawing. Mixing it as a processing aid has been considered for some time.

However, all of these known techniques have significant drawbacks.

That is, a copolymer of styrene and acrylonitrile not only deteriorates thermal stability but also does not significantly improve processing properties such as gelation rate and deep drawing.

Compared to this, copolymers mainly composed of methyl methacrylate and styrene and copolymers mainly composed of methyl methacrylate and alkyl acrylate have a greater effect of accelerating the gelation rate and also increase the tensile elongation at high temperatures. As a result, it enables deep drawing and greatly improves secondary processability such as vacuum forming.

However, on the other hand, ungelled substances (fish eyes) are likely to occur, and the effect of improving the surface smoothness of shaped products such as extruded films is insufficient.

That is, depending on the conventional processing aids, it has been impossible to achieve a highly satisfactory surface smoothness of the molded product and to extremely reduce the amount of ungelled material in the molded product.

According to conventional knowledge, in order to improve the surface smoothness of a molded product, it is necessary to increase the degree of polymerization of a polymer processing aid, and on the other hand, to reduce the amount of ungelled material in a molded product, it is necessary to increase the degree of polymerization of a polymer processing aid. It is believed that it is necessary to lower the degree of polymerization of the agent, and there has not yet been a technology that can simultaneously satisfy both conditions to a high degree.

Surprisingly, however, the present inventors have found that a processing aid consisting of a copolymer of alkyl methacrylate and dialkyl itaconate and an alkyl methacrylate-based polymer significantly reduces ungelled substances and is extremely excellent in surface smoothness. I discovered that (Patent application 1973-333
No. 18).

However, copolymers of alkyl methacrylates and dialkyl itaconates and processing aids made of alkyl methacrylate polymers are not without drawbacks.

For example, in calendering, which has become increasingly important as a sheet or film forming method in recent years because the above-mentioned processing aids have relatively high adhesion to metal surfaces, the composition with vinyl chloride resin It has the disadvantage of increased tackiness and therefore defects on the sheet or film surface.

Furthermore, since the above-mentioned processing aids have a high glass transition humidity (Tg), the powder obtained by salt (acid) precipitation of the emulsion produced by emulsion polymerization produces a large amount of fine powder of 40μ or less, resulting in poor workability. Moreover, it also has the disadvantage of being accompanied by various difficulties in the manufacturing process and processing.

The present inventors have conducted extensive studies with the aim of improving the above two drawbacks without sacrificing the excellent advantages of copolymers consisting of alkyl methacrylates and dialkyl itaconates and processing aids consisting of alkyl methacrylate polymers. As a result, the above two drawbacks were solved at once by adding alkyl acrylate as a constituent monomer to a copolymer consisting of alkyl methacrylate and dialkyl itaconate, and vinyl chloride resin compositions to which this was added were found to be The inventors have discovered that a molded article containing very little gelled material, transparent and with excellent surface smoothness can be obtained, and has processing characteristics such as low adhesion to rolls, and has thus arrived at the present invention.

That is, the present invention provides a vinyl chloride resin composition comprising 100 parts by weight of a vinyl chloride resin and 0.1 to 30 parts by weight of a processing aid, wherein the processing aid is 20 parts by weight of an alkyl methacrylate.
~79% by weight, dialkyl itaconate 1-60% by weight
, a copolymer (4) consisting of more than 20% by weight of alkyl acrylate and not more than 60% by weight of alkyl methacrylate, or 20 to 79% by weight of alkyl methacrylate, and dialkyl itaconate 1 to 6
Copolymer (4) consisting of 0% by weight, 20 to 60% by weight of alkyl acrylate 1 and 50% by weight or less of one or more monomers copolymerizable with these (4)' 10 to 90 parts by weight , and 90 to 10 parts by weight of a copolymer consisting of 80 to 100% by weight of an alkyl methacrylate and 0 to 20% by weight of one or more monomers copolymerizable with the alkyl methacrylate [Copolymer ( 4) or a total amount of W and copolymer B) of 100 parts by weight], and is a polymer obtained by adding and polymerizing one copolymer with a monomer constituting the other copolymer. It is a transparent vinyl chloride composition with good processability.

The present invention will be explained in detail below.

The processing aid of the present invention is a copolymer containing alkyl methacrylate, dialkyl r-taconate, and alkyl acrylate, or a copolymer containing alkyl methacrylate, dialkyl itaconate, alkyl acrylate, and a monomer copolymerizable with these. It consists of an alkyl methacrylate copolymer (B) and is a polymer obtained by addition polymerization of monomers constituting the other copolymer in the presence of one copolymer.

In this case, copolymer (4) or copolymer (B
) may be added and polymerized with the monomers constituting the copolymer (4) or copolymer (B) with the monomers constituting the copolymer (B). Needless to say.

However, a particularly preferable form is to add copolymer (B) to copolymer (B).
4) or one obtained by addition polymerization of monomers constituting (2).

Compared with other forms, such a form is less likely to produce ungelled substances and is also excellent in surface smoothness and transparency.

Note that addition polymerization is used in a broader sense than graft polymerization, and is not limited to monomers in which all of the monomers constituting the second-stage polymer are graft-polymerized with respect to the first-stage polymerization. It also includes cases in which some of the monomers are polymerized without graft polymerization and are simply polyblended.

Further, in the present invention, copolymer (4) or X10
~90 parts by weight of the copolymer (90 to 10 parts by weight of toughness is used).

If the amount of the copolymer (B) is less than the above range, the performance as a processing aid will deteriorate, and if it is more than the above range, a large amount of ungelled material will be generated, which is not preferable.

Copolymer (4) contains 20 to 79% by weight of alkyl methacrylate, preferably 20 to 60% by weight, dialkyl itaconate 1 to 60% by weight, preferably 10 to 60% by weight, more preferably 10 to 40% by weight, and alkyl acrylate. More than 20% by weight and not more than 60% by weight, copolymer □ is 20-79% by weight of alkyl methacrylate, preferably 20-6% by weight
0% by weight, dialkyl itaconate 1-60% by weight, preferably 10-50% by weight, alkyl acrylate 20-60% by weight
It consists of 60% by weight, preferably 20 to 50% by weight, and 50% by weight or less, preferably 5 to 50% by weight of one or more monomers copolymerizable with these.

If the amount of dialkyl itaconate is less than the above range, the resulting processing aid will not be sufficiently dispersed under normal processing conditions for vinyl chloride resins, resulting in the drawback that a large amount of ungelled material will remain.

Furthermore, if the hot melt fluidity is increased by lowering the degree of polymerization of the processing aid, no ungelled material will remain, but the effect of improving the processability of the vinyl chloride resin will be reduced.

Furthermore, when the amount of dialkyl itaconate is increased beyond the above range, the transparency of the vinyl chloride resin composition decreases.

The larger the amount of alkyl acrylate used, the lower the glass transition temperature (Tg) of the copolymer (4). When used, it has the effect of preventing adhesion to the roll surface, but too much of it impairs the performance of the processing aid.

Therefore, it is limited to the above range.

As the alkyl methacrylate constituting the copolymer (4), an alkyl methacrylate having an alkyl group having 1 to 8 carbon atoms, preferably 1 to 4 carbon atoms is used, and methyl methacrylate is particularly preferred.

Similarly, the dialkyl itaconate constituting the copolymer (4) or the carrier has an alkyl group having 1 to 1 carbon atoms.
18, preferably 1 to 10 dialkyl itaconates are used, with diethyl itaconate and dibutyl itaconate being particularly preferred.

As the alkyl acrylate, methyl acrylate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, etc. are used, and ethyl acrylate and butyl acrylate are particularly preferred.

Further, monomers copolymerizable with alkyl methacrylate, dialkyl itaconate, and alkyl acrylate in the copolymer include, for example, aromatic vinyls such as styrene, α-methylstyrene, and chlorostyrene, acrylonitrile, and methacrylonitrile. etc. unsaturated dil
vinyl ethers such as methyl vinyl ether and ethyl vinyl ether; vinyl ketones such as methyl vinyl ketone and ethyl vinyl ketone; and vinyl esters such as vinyl acetate.

50% by weight without impairing its performance as a processing aid
Hereinafter, preferably 5 to 50% by weight, one type or two or more types can be used in combination.

Copolymerized mTU1 or alkyl methacrylate 80-100
% by weight, preferably 90 to 100% by weight, and 0 to 20% by weight, preferably 0 to 10% by weight of one or more monomers copolymerizable with the alkyl methacrylate; Combine (A)
Alternatively, an alkyl methacrylate similar to the alkyl methacrylate in (4)' is used.

If the alkyl methacrylate content in the copolymer (B) is less than the above range, the effect of improving the processability of the composition will be reduced, which is not preferred.

Examples of monomers copolymerizable with alkyl methacrylate include acrylic esters such as methyl acrylate, ethyl acrylate, n-butyl acrylate, and 2-ethylhexyl acrylate, styrene, α-methylstyrene, Aromatic vinyls such as chlorstyrene 1. Unsaturated nitriles such as acrylonitrile and methacrylonitrile, vinyl ethers such as methyl vinyl ether and ethyl vinyl ether, vinyl ketones such as methyl vinyl ketone and ethyl vinyl ketone, and vinyl esters such as vinyl acetate are used.

Copolymer (4) or (N and copolymer () in the processing aid)
The proportions of copolymer (4) or (4)' are in the range of 10 to 90 parts by weight, and copolymer (B) is in the range of 90 to 10 parts by weight, based on 100 parts by weight of the total amount of both.

The processing aid of the present invention can be produced by a known method, but it is advantageous if it has a degree of polymerization above a certain level when mixed with a vinyl chloride resin.

The degree of polymerization is generally related to the composition and degree of polymerization of the vinyl chloride resin, but the reduced viscosity of 100 cc of a chloroform solution of 0.4 ml of processing aid measured at 20°C is 0.1 d.
17g or more, preferably 0.5d17s or more is advantageous.

The vinyl chloride resin to be mixed with the processing aid of the present invention is polyvinyl chloride, a copolymer of 80% by weight or more of vinyl chloride and one or more monomers copolymerizable therewith, and polyvinyl chloride. Derivatives such as chlorinated compounds or mixtures of one or more of these.

Add stabilizers, antioxidants, ultraviolet absorbers, and lubricants as necessary.

Auxiliary agents such as an impact strength enhancer, a plasticizer, a coloring agent, a filler and a blowing agent are added.

The processing aid of the present invention is added in an amount of 0.1 to 30 parts by weight, preferably 0.15 to 10 parts by weight, per 100 parts by weight of the vinyl chloride resin.

If the amount is less than this range, the effect of improving processability will be insufficient, and if it exceeds this range, the inherent properties of the vinyl chloride resin will change, which is not preferable.

Examples are shown below, but the present invention is not limited thereto.

(All parts in the examples are parts by weight.

) Example 1 In a reaction vessel equipped with a stirrer, 300 parts of distilled water, 1.0 part of sodium dodecylbenzenesulfonate previously dissolved in water, 0.03 part of potassium persulfate, and 0.0 parts of sodium bisulfite were added.
0.0075 parts of methyl methacrylate, 75 parts of n-dodecyl mercaptan, and 0.045 parts of n-dodecyl mercaptan were charged, and after purging the inside of the container with nitrogen, the temperature of the reaction container was raised to 50'C while stirring, and the reaction was allowed to proceed for 6 hours at this hot water temperature. Thereafter, 0.01 part of potassium persulfate, 0.0 part of hydrogen sulfite
025 parts and methyl methacrylate lO, 0 parts, dibutyl itaconate 6.0 parts, butyl acrylate 9.0 parts
1 part, and 0.0025 part of n-dodecylmercaptan were added thereto, and the mixture was reacted at 50°C for 15 hours.

After cooling, the latex produced was salted out using aluminum sulfate, and then neutralized.

The mixture was filtered, washed with water, and dried to obtain a power [ ] I auxiliary agent (Taki 1).

The conversion rate was 99.0%. Three parts of the above processing aid was added to polyvinyl chloride (average degree of polymerization 700).
) 100 parts, 2 parts of dioctyltin mercapto compound, 0.8 parts of stearyl alcohol, and 0 parts of moncnic acid ester
．． The test shown in Table 1 was conducted and the results shown in Table 3 were obtained.

Example 2 In place of the processing aid in Example 1, a processing aid with the composition and reduced viscosity shown in Table 2 (processing aid/g 62-7) was polymerized, and using this, the processing aid in Table 1 was prepared in the same manner as in Example 1. The following tests were conducted and the results shown in Table 3 were obtained.

The redox initiator used in all examples was No. 1.2.
Potassium persulfate is 0.0% per 100 parts of 7-mer in each row.
0.04 parts and 0.01 part of sodium bisulfite.

(The same applies to the following comparative examples.) Comparative Example 1 Processing aids (processing aids Aa, b, c, d) having the composition and reduced viscosity shown in Table 2 were polymerized in the same manner as in Example 1. The tests shown in Table 1 were carried out in the same manner as in Example 1, using the same method as in Example 1, and the results shown in Table 3 were obtained.

Example 3 A portion corresponding to copolymer (4) of processing aid/+62.3, 4, 7 was separately polymerized, and the glass transition temperature (Tg) of these copolymers was determined from the change in refractive index with humidity. Ta.

The results are shown in Table 4. Copolymer constituting processing aid (4)
When the glass transition temperature (Tg) of
There is a small amount of fine powder below μ (10% or less), and subsequent swimming,
Handling such as filtration and drying was easy.

The polymerization recipe is 100 parts of monomer (including n-dodecyl mercaptan), 300 parts of water, 1.0 part of sodium dodecylbenzenesulfonate, 1 part of potassium persulfate O, and 1 part of OS.
．． 0.02 part of sodium bisulfite, 1 at 50°C
It was polymerized for 6 hours.

Comparative Example 2 Similarly to Example 3, the portion corresponding to the copolymer (4) constituting the processing aids Aa, b, c, and d was separately polymerized, and Example 4 was obtained.
The glass transition temperature (TP) was measured in the same manner as above, and the results are shown in Table 4.

When the copolymer (4) has a glass transition temperature of 50'C or higher, salting out under normal conditions results in 4.
A large amount of fine powder of 0μ or less was generated (15% or more), making subsequent handling difficult.

Example 4 90 parts of polyvinyl chloride (average degree of polymerization 700).

Impact resistance imparting agent (BTA-III8, manufactured by Kureha Chemical Co., Ltd.) 10
Department.

3.5 parts of dibutyltin stabilizer, 1.5 parts of organotin stabilizer
0.2 parts of liquid paraffin, 0.1 part of stearic acid, and 1.0 parts of processing aids 3, 4, 5, and 7 were added and mixed, and these were mixed to a thickness of 0.1 door π and 0.3 mm. Width 30cfrL
It was processed into a T-Gui sheet.

The tests shown in Table 6 were conducted on these T-die sheets, and the results shown in Table 7 were obtained.

Comparative Example 3 The tests in Table 6 were conducted in exactly the same manner as in Example 4 using processing aids/i6a, c and commercially available processing aids/16c, f containing two methyl methacrylates as main components, and the results shown in Table 7 were obtained. Obtained.

As a comparative example, the tests shown in Table 6 were also carried out on products without the addition of processing aids, and the results shown in Table 7 were obtained.

As shown in Table 7, the products of the present invention are superior to commercially available products in terms of surface gloss and ungelled materials.

In addition, compared to processing aids Aa and c, it has superior roll adhesion and manufacturability as shown in Tables 3 and 4 (although its performance as a processing aid as shown in Table 7 is almost unchanged). do not have.

As is known from the examples, the characteristics of the composition of the present invention are the composition of alkyl methacrylate and dialkyl itaconate, which is the invention of Japanese Patent Application No. 53-33318 (hereinafter referred to as the "prior invention"), which is an earlier application of the present inventor. It is superior to a composition consisting of a processing aid made of a polymer, an alkyl methacrylate copolymer, and a vinyl chloride resin.

In other words, when molded, ungelled matter (fish,
(Example 4.
Comparative Example 3) was improved in roll tackiness, which was a drawback of the prior application composition.

(Examples 1 and 2. Comparative Example 1). Furthermore, since the processing aid that makes up the composition of the prior application has a high glass transition temperature (TJ), latex particles do not coagulate sufficiently, and many fine particles of 40 mesh or less are generated, so washing, filtration, drying, etc. However, in the present invention, this point has also been improved (Example 3, Comparative Example 2).

Furthermore, the composition of the present invention does not lose the excellent properties originally possessed by vinyl chloride resins, and has excellent processability in all types of processing of vinyl chloride resins, such as extrusion molding, calendar processing, blow molding, and injection molding. However, the finish of the molded product obtained is significantly improved.

For example, in (1) calender processing, the resin is kneaded quickly during roll kneading and gelation is promoted, so that the resin is well kneaded and a sheet with an excellent surface condition can be obtained.

Furthermore, the elongation at break of the film during processing is improved, making it easier to stretch and form very thin films.

(2) Flow molding significantly improves drawdown of the parison, uneven thickness of the molded product, roughness, etc.

(3) In pipe and profile extrusion, gelation is promoted and the resin is well kneaded, resulting in products with excellent surface gloss and mechanical properties.

(4) In injection molding, defects such as jetting and gate flash that are often seen near the gate of molded products are improved, and glossy molded products can be obtained.

(5) T-die extrusion significantly improves the surface gloss of the extrudate and eliminates processing troubles such as flow marks.

Furthermore, since the elongation at break during processing is significantly increased, a film of uniform thickness can be easily obtained when extruding a very thin film by stretching.

(6) Vacuum forming increases the tensile strength and elongation at break when heated at high temperatures, and prevents sagging when heating the sheet, making deep drawing easier, and forming large or complex shapes. It also becomes possible.

In particular, the surface condition of the molded product is significantly improved.

As mentioned above, the composition of the present invention has many excellent points.

Claims (1)

[Claims] 1. 100 parts by weight of vinyl chloride resin and 0.1 to 0.1 parts of processing aid
In the vinyl chloride resin composition consisting of 30 parts by weight, the processing aids include 20 to 79% by weight of alkyl methacrylate, 1 to 60% by weight of dialkyl itaconate, and more than 20% by weight and not more than 60% by weight of alkyl acrylate. copolymer (4) or alkyl methacrylate 20
~79% by weight, dialkyl itaconate 1-60% by weight
, 20 to 60% by weight of alkyl acrylate and 50% by weight of one or more monomers copolymerizable with these.
Copolymer (A)'io~90 parts by weight consisting of the following,
and a copolymer (B
190 to 10 parts by weight [total amount of copolymer (A) or ridges and copolymer (B) 100 parts by weight], and one copolymer contains monomers constituting the other copolymer. A transparent vinyl chloride resin composition with good processability, characterized in that it is a polymer obtained by addition polymerization.