JPH0314061B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a powdery plasticizer for thermoplastic resins in which a plasticizer is coated with a polymer film, and a method for producing the same. Thermoplastic resins, particularly vinyl chloride resins and vinylidene chloride resins, are blended with plasticizers in appropriate proportions to adjust the hardness of the final molded product. However, there is a limit to the amount of plasticizer blended, and if the plasticizer is blended in an amount exceeding the limit, the resin surface will become sticky.
Alternatively, uniform mixing with the resin may not be achieved, leading to major troubles during the manufacturing process or after commercialization. On the other hand, vinyl chloride resins have material properties (e.g. secondary processability, weather resistance) that rubber molded products do not have, and these are better than soft vinyl chloride resins obtained with normal plasticizer content. softer than
There is a demand for so-called extremely soft vinyl chloride resins. However, as mentioned above, if we take vinyl chloride resin for example, the amount of plasticizer used is at most 200 parts per 100 parts of the resin component, and the resulting hardness is at least 40 parts. Therefore, in order to obtain a softer vinyl chloride resin, vinyl chloride monomers and small amounts of other vinyl monomers, such as vinyl esters, vinyl ethers, or α
- Methods of copolymerizing olefins have been considered, but fully satisfactory results have not been obtained. The present inventors have conducted research into softening thermoplastic resins, particularly vinyl chloride resins and vinylidene chloride resins, by micro-encapsulating a portion of the plasticizer using a polymer membrane. It was revealed that it is possible to add plasticizer in an amount approximately twice the conventional limit addition amount, and the present invention was completed. That is, the present invention relates to a powdery plasticizer for thermoplastic resins in which 70 to 95 parts by weight of a plasticizer is microencapsulated with 30 to 5 parts by weight of a resin for forming a polymer film. The plasticizer used in the present invention is a plasticizer commonly used for thermoplastic resins, such as phthalic acid plasticizers such as dioctyl phthalate and dibutyl phthalate; trimellitic acid plasticizers such as tributyl trimellitic acid; and octyl laurate. aliphatic
Basic acid ester plasticizers; aliphatic dibasic acid ester plasticizers such as dioctyl diadipate; aromatic alcohol ester plasticizers; hydroxy acid ester plasticizers; coal tar distillate plasticizers; epoxy plasticizers; Any plasticizers such as phosphoric acid esters and polyester plasticizers can be applied. The polymer film-forming resin used in the present invention may be any film-forming component that does not melt or collapse under the conditions of mixing the thermoplastic resin and the plasticizer. A typical example of such a polymer film-forming resin has the general formula: CH ₂ =CX-COOR [] [wherein, X represents hydrogen or methyl, and R represents hydrogen or an alkyl group having 1 to 18 carbon atoms] ] and a monomer represented by the general formula: CH ₂ = CYZ [] [wherein, Y represents chlorine and Z represents hydrogen or chlorine]. . The compound represented by the general formula [ ] is free acrylic acid or methacrylic acid or esters thereof. Acrylic acid-based gives a more flexible coating,
Since the methacrylic acid type gives a harder coating, both may be used in an appropriate combination depending on the desired properties. Most generally, those having an acrylic acid/methacrylic acid ratio (molar ratio) of 0 to 50/50 to 100 are preferred. All or part of (meth)acrylic acid may be esterified. The alcohol used for esterification is not necessarily limited, and aliphatic alcohols, aromatic alcohols, alicyclic alcohols, aromatic-aliphatic alcohols, etc. can be used as appropriate, but aliphatic alcohols are most preferred. Moreover, styrene, vinyl acetate, acrylamide, acrylonitrile, etc. can also be used in place of some of these monomers. The monomer represented by the general formula [ ] is vinyl chloride or vinylidene chloride. These enhance the affinity between the microencapsulated plasticizer and the resin when the thermoplastic resin to be plasticized is a resin such as vinyl chloride resin or vinylidene chloride resin (these are particularly typical examples). The above is very useful. When using monomer [] and monomer [], the blending ratio of both is []50
A range of 99 parts by weight/[]50 to 1 part by weight is particularly preferred. The polymer membrane contains at least 99% by weight of the compound of the general formula [] and 1% by weight of the compound of the general formula []
When the copolymer is composed of the following copolymers, the film strength is improved and the encapsulation rate of the plasticizer in the powdery plasticizer can be improved. When mixed with a plasticizer to make a molded product, the film surface of the powder is not compatible with the surrounding plasticized vinyl chloride resin part, so spots (note) may appear in the molded product (see below for examples). "bumps" are likely to occur. On the contrary, the aforementioned polymer membrane contains less than 50% by weight of the compound of the general formula [], and 50% by weight of the compound of the general formula []
If the copolymer is composed of a copolymer exceeding Mixing for molding processing,
The kneading, stirring and heating operations tend to destroy the membrane constituting the powdered material. As a result, the internal plasticizer may be leached out, making it impossible to mix, knead, or mold the composition. Furthermore, the polymer membrane-forming resin of the present invention may be copolymerized with a monomer having two or more unsaturated bonds. Specific examples of such monomers include, for example, 1,4-hexadiene and 2-
Linear non-conjugated dienes such as methyl-1,4-pentadiene, monocyclic dienes such as cyclopentadiene and 1,5-cyclooctadiene, 4,7,
Bicyclic dienes such as 8,9-tetrahydroindene, polyalkenylcycloalkanes such as 1,2,4-trivinylcyclohexane, 5-methylene-norbornene, 5-butene-2-norbornene, 5-ethylidene-2-norbornene There are norbornenes such as. These monomers having two or more unsaturated bonds are desirably added in an amount of 10 parts by weight or less per 100 parts by weight of the monomers [] and [].
When a plasticizer microencapsulated with such a copolymer resin is added to a thermoplastic resin, the tensile strength of the molded article is improved. This is thought to be due to the heating operation in the molding process and the accompanying crosslinking reaction forming between the encapsulation film and the vinyl chloride resin. Even if 10 parts by weight or more of such monomers are added, no particular improvement in effect is observed. Regarding the amount of the polymer film-forming resin to be used relative to the plasticizer, it is preferable to use 30 to 5 parts by weight of the polymer film forming resin to 70 to 95 parts by weight of the plasticizer. When the plasticizer content exceeds 95 parts by weight, the thickness of the coating becomes relatively thin and the strength for retaining the plasticizer decreases.
As a result, during the mixing and heating step for forming the vinyl chloride resin composition, the powdery plasticizer coating may be torn and the internal plasticizer may be leached out. On the other hand, if the plasticizer content is less than 70% by weight, the powdered plasticizer film becomes relatively thick, and the mixing process for producing a vinyl chloride resin composition or the subsequent kneading process for producing a molded product becomes difficult. In this case, the miscibility with other components decreases, and as a result, there is a risk that powdery plasticizer will appear as spots in the thermoplastic resin molding. When a polymer membrane-forming resin containing the above-mentioned monomers is used, the physical properties of the final molded product, especially the tensile strength, etc., do not substantially deteriorate compared to when the powdery plasticizer of the present invention is not used. Although the particle size of the powdery plasticizer for thermoplastic resins used in the present invention is not particularly limited, it is preferably 1 to 100 μm, particularly 5 to 50 μm. The powdery plasticizer of the present invention may be produced by a general microencapsulation method, such as a coacervation method, an interfacial polymerization method, a spray drying method, an in-liquid curing method (orifice method), an in-situ polymerization method, or the like. Particularly preferred is in-situ polymerization; coacervation methods, interfacial polymerization methods, spray drying methods, and in-liquid curing methods (orifice methods) generally cannot yield satisfactory powdery plasticizers. The present invention will be explained below with reference to Examples and Comparative Examples. However, the present invention is not limited thereto. In addition, physical property tests of the compositions and molded articles in Examples and Comparative Examples were conducted by the following methods. (B) Blendability: In a 75-capacity Healthiel mixer (trade name), 5 kg of vinyl chloride resin with an average degree of polymerization of 2900, 0.1 kg of Ca-Zn stabilizer, 1 kg of calcium carbonate, and the powdered plasticizer of the present invention were added as DOP. Converts to 2.8Kg and Dioctyl Phthalate (DOP)
10 kg was charged, heated to 140° C. while mixing, then cooled to 70° C., and visually judged whether it could be taken out as a homogeneous mixture from the mixer. [Judgment] ◎: Extremely easy to remove. 〇: Can be taken out △: Slightly difficult to take out Test pieces were prepared according to each measurement purpose by pressing at 180°C (using a 36Ton press). JIS for these test pieces
Tables 1 and 2 show the results of measurements conducted in accordance with K6301. [Criteria for determining spots] ◎: No spots 〇: Some spots △: Some spots ×: Lots of spots Examples 1 to 5 In addition to the amounts of dioctyl phthalate, methyl methacrylate, and vinylidene chloride shown in Table 1 below, Diisopropyl peroxydicarbonate 15
First, an oil phase composition was prepared by mixing g. Next, 2800 g of deionized water, 1390 g of colloidal silica dispersion (solid content 20%), 2.5 g of potassium dichromate
% aqueous solution and 90 g of a 10% aqueous solution of a condensate of diethanolamine and adipic acid were mixed and adjusted to pH 4 using hydrochloric acid to prepare an aqueous phase composition. Subsequently, both compositions were placed in a high-speed stirring tank,
A mixed solution was prepared by mixing at 10,000 rpm for 60 seconds.The entire amount of this mixed solution was charged into a pressurized polymerization reactor with a capacity of 15 that had been purged with nitrogen in advance, and the internal pressure was 3.5 to 4.5 Kg/cm ² G.
The reaction was carried out at 50°C for 20 hours. Next, the reaction mixture was cooled and depressurized, and the solid content contained therein was repeatedly centrifuged and washed with water (at 50°C under reduced pressure), and then dried to obtain a white powder with an average particle size of 15 to 30μ. . Table 1 shows the physical properties of a vinyl chloride resin composition using this white powder. Comparative Example 1 Instead of the powdered plasticizer in (a) of the physical property test method,
DOP2.8Kg (DOP equivalent amount of powdered plasticizer of the present invention)
Table 1 shows the results of physical property tests conducted using the following. Comparative Example 2 The total amount of monomer is methyl methacrylate,
The same procedure as in Example was carried out except that white powder was obtained.

[Table] Although not shown in Table 1, as a result of testing the blooming properties of the molded products, no blooming was observed in any of the molded products. Examples 6 to 10 2800 g of dioctyl phthalate, 630 g of methyl methacrylate, 70 g of vinylidene chloride and the table below.
A white powder was obtained in the same manner as in Example 3, except that 5-ethylidene-2-norbornene was used in the amount shown in Example 2. Table 2 shows the physical property test results using this white powder.

[Table] (Note) For each No., the raw material monomers are methyl methacrylate and vinyl chloride.
630g and 70g of each were used.
As is clear from the comparison between Table 2 and the results of Example 3 in Table 1, in preparing the powdered plasticizer, in addition to methyl methacrylate and vinylidene chloride, a relatively small amount of 5-ethylidene-2-norbornene was used. It can be seen that the tensile strength of the final molded product is significantly improved when an appropriate amount of is added.

Claims (1)

[Scope of Claims] 1. 70 to 95 parts by weight of plasticizer to 30 parts by weight of polymer film forming resin.
Powdered plasticizer for thermoplastic resin microencapsulated at ~5 parts by weight. 2 The resin for forming a polymer film is a monomer represented by the general formula: CH ₂ =CX-COOR [] [wherein, X represents hydrogen or methyl, and R represents hydrogen or an alkyl group having 1 to 18 carbon atoms] 50 to 99 parts by weight, 50 to 1 part by weight of a monomer represented by the general formula: CH ₂ = CYZ [] [in the formula, Y represents chlorine and Z represents hydrogen or chlorine] and two or more unsaturations. 2. The powdery plasticizer for thermoplastic resins according to item 1, which is a copolymer containing 0 to 10 parts by weight of a monomer having a bond. 3 Monomers having two or more unsaturated bonds are linear non-conjugated dienes, monocyclic dienes, bicyclic dienes,
2. The powdery plasticizer for thermoplastic resins according to item 1, which is polyalkenylcycloalkanes and norbornene dienes. 4. The first powder plasticizer has a particle size of 1 to 100 μm.
Powdered plasticizer for thermoplastic resins as described in . 5 Powder for thermoplastic resin in which 30 to 5 parts by weight of a resin monomer for forming a polymer film is polymerized in situ in the presence of 70 to 95 parts by weight of a plasticizer, and the plasticizer is microencapsulated with the resin for forming a polymer film. Manufacturing method of plasticizer. 6 Polymer film-forming resin is a monomer represented by the general formula: CH ₂ =CX-COOR [] [wherein, X represents hydrogen or methyl, and R represents hydrogen or an alkyl group having 1 to 18 carbon atoms] 50 to 99 parts by weight, 50 to 1 part by weight of a monomer represented by the general formula: CH ₂ = CYZ [] [in the formula, Y represents chlorine and Z represents hydrogen or chlorine] and two or more unsaturations. 6. The method for producing a powdery plasticizer for thermoplastic resins according to item 5, which is a copolymer containing 0 to 10 parts by weight of a monomer having a bond. 7 Monomers having two or more unsaturated bonds are linear non-conjugated dienes, monocyclic dienes, bicyclic dienes,
6. The method for producing a powdery plasticizer for thermoplastic resins according to item 5, which is polyalkenylcycloalkanes and norbornene dienes.