JPS6343941A - Thermoplastic resin composition - Google Patents

Abstract

PURPOSE:To provide the title compsn. having excellent flexibility, impact resistance, transparency and processability, consisting of a polymer obtd. from an acrylate monomer and a copolymer obtd. by reacting a vinylidene fluoride polymer with other acrylate monomer. CONSTITUTION:100pts.wt. vinylidene fluoride polymer (a) obtd. by polymerizing a monomer mixture contg. at least 50% vinylidene fluoride is reacted with 5-500pts.wt. acrylate monomer (b) of formula I (wherein R3 is H or CH3; and R4 is a 1-10C alkyl) in the presence of a polymn. initiator (c) such as t-butyl peroxyallylcabonate, etc., by a chain transfer method to obtain a copolymer (B). 100pts.wt. acrylate polymer (A) obtd. by polymerizing an acrylate monomer of formula II (wherein R1 is R3; and R2 is R4) is blended with 1-100pts.wt. component B.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a thermoplastic resin composition comprising a polyvinylidene fluoride polymer and an acrylate resin having improved physical properties.

Polyvinylidene fluoride resin (hereinafter abbreviated as PVDF) has excellent heat resistance, chemical resistance, mechanical properties, and electrical properties. Furthermore, among fluororesins, it is particularly easy to process, so it is used in industrial applications such as metal laminates, electric wire coverings, and coatings.

However, PVDF is a crystalline resin and has a high crystallization rate. This high degree of crystallinity contributes to some mechanical properties, but conversely, this crystallinity causes a lack of flexibility, which can be a drawback in some cases. For example, when creating a stretched film, it is known that a high degree of molecular orientation occurs, resulting in a decrease in tear strength and, depending on the use of the stretched sheet, the phenomenon that breakage is likely to occur. Therefore, in order to suppress this crystallinity, attempts have been made to mix other compatible resins or plasticizers. However, P
Since there are few resins or plasticizers that are compatible with VDF, a heterogeneous mixture may be formed in the case of a large amount of plasticizer, which may have an adverse effect on the physical properties of PVDF. Methyl methacrylate resin is known as an exception (see Japanese Patent Publication No. 55-35042).In addition, other similar acrylate polymers or copolymers are also known to have good compatibility.

However, the compatibility state of the composition obtained by simply mixing these acrylate polymers with PVDF is a low-temperature dissolution state where there is a so-called LC3T (lower critical co-solubilization temperature) where they are compatible at low temperatures but not at high temperatures. type, P V
In a composition containing a large amount of DF, PVDF crystallizes when heated, so that its heat resistance stability is poor. On the other hand, if the proportion of PVDF in the mixture is reduced, there is a drawback that the mechanical properties thereof are significantly reduced. The present inventors completed the present invention as a result of conducting research to solve these drawbacks.

The present invention is based on -Momonana (wherein R1 is a hydrogen atom or a methyl group, R2 is a carbon number 1
100 parts by weight of a polymer (A) obtained from a monomer represented by -10 alkyl groups) and a polymer (B) obtained from a monomer mainly consisting of vinylidene fluoride. In the formula, R3 is a hydrogen atom or a methyl group, and 8 is a carbon number of 1 to 1
This is a thermoplastic resin composition comprising 1 to 100 parts by weight of a copolymer (C) obtained by reacting with a monomer represented by (0) representing an alkyl group.

In the resin composition of the present invention, the mechanical properties such as flexibility and impact resistance of PVDF and the properties such as excellent transparency and processability of the acrylate polymer can be varied widely by changing the mixing ratio of both components. can.

As the monomer mainly consisting of vinylidene fluoride, a monomer mixture containing 50% or more of vinylidene fluoride is used.

Methods for reacting a polymer obtained from a monomer mainly containing vinylidene fluoride (hereinafter referred to as a vinylidene fluoride polymer) with an acrylate monomer of formula (2) include a chain transfer method and a radiation irradiation method. , a method using unsaturated peroxide, etc.

The chain transfer method is a method of polymerizing other monomers in the presence of a polymer, and is the simplest method. When vinylidene fluoride polymers are used, it is difficult to generate radicals on the base resin due to the presence of C-F bonds, but by selecting the polymerization initiator, solvent, and polymerization conditions, it can be done economically. can be carried out advantageously. The method of using unsaturated peroxide is to copolymerize a monomer (unsaturated peroxide) having a polymerizable double bond and a peroxy group in its molecule during polymerization of the base resin, and then to copolymerize the peroxy group of the base resin. This is a method in which the polymerization of the branch resin is initiated from the generated radicals. In this method, an unsaturated peroxide, such as t-butyl Preference is given to using peroxyallyl carbonate. Although the radiation irradiation method requires special equipment, it has the advantage of being widely applicable.

When producing the copolymer (C) by reacting the vinyl fluoride + 7-dene polymer (B) with the monomer of formula (2), the polymer (
B) It is preferable to use 500 parts by weight of 5 monomers of formula (1) per 100 parts by weight.

The resin composition of the present invention is prepared by adding a copolymer (A) to 100 parts by weight of an acrylate polymer (A) obtained from the monomer of formula
C) obtained by mixing 1 to 100 parts by weight.

If the amount of copolymer (C) used is less than 1 part by weight, the compatibility improvement effect will not be sufficient, and if it is more than 100 parts by weight, the original transparency and processability of the acrylate polymer (A) will be impaired. may be damaged.

The resin composition of the present invention is preferably melt-kneaded and then molded into a pellet shape.

Example 1 Deionized and deoxidized water 1 was placed in a 22 volume autoclave equipped with a stirrer and an external temperature control jacket.
000,9, ammonium persulfate 2N, ammonium perfluorooctanoate 2g and t-butylperoxyallyl carbonate 2g were charged, and after purging with nitrogen gas 6 times, vinylidene fluoride monomer 2001 was charged and heated at a temperature of 55°C with stirring. The reaction was carried out for 20 hours. After salting out the obtained white latex-like product and washing with water,
Wash with n-hexane to remove unreacted t-butylperoxyallyl carbonate, and dry under vacuum to obtain white powder 1.
35I was obtained. The DSC curve of this polymer was based on the decomposition of the peroxy groups (had an exothermic peak at 160-180°C).

In a 500 ml reactor equipped with a stirrer, 80 g of the vinylidene fluoride copolymer was mixed with 20 g of dimethylformamide.
0y, methyl methacrylate monomer 201 was added as a graft monomer, and the mixture was maintained at a temperature of 95° C. for 6 hours with stirring. After the reaction, the reaction solution was poured into a large amount of ethanol, the precipitated polymer was separated from the solvent, and then dried to obtain Graft Copolymer 789 as a white powder.

To 2 og of this copolymer, 100 fi of polymethyl methacrylate (P-MMA) was added as a pre-coated polymer and melt mixed at 190 to 230°C to obtain a resin composition pellet.

This pellet was injection molded to prepare a test piece, and its bending strength, transparency, and impact strength were measured.

The impact strength was measured by performing a notched Izot impact test according to ASTM-D-256. Transparency is AST
Total light transmittance was measured according to M D 1003. Bending strength was measured according to ASTM-D-790. The results are shown in Table 1.

Examples 2 and 3 The mixing ratio of vinylidene fluoride graft copolymer was 40
phr and 60 phr, and otherwise obtained in the same manner as in Example 1 to obtain a resin composition. Its physical properties are shown in Table 1.

Comparative Example 1 A polyvinylidene fluoride polymer containing no t-butylperoxyallyl carbonate was produced using the same composition and conditions as in Example. In the same manner as in Example 1, 20 g of this polyvinylidene fluoride was added to 100 g of P-MMA pellets, melt mixing was performed, and various test pieces were obtained by injection molding. The measurement results are shown in Table 1. It is known that the breaking strength and impact strength are inferior.

Table 1 Examples 4 to 6 The composition of the vinylidene fluoride copolymer and the graft monomer and the mixing ratio to P-MMA were changed as shown in Table 2, and the other conditions were the same as in Example 1. A resin composition was obtained. Its physical properties are summarized in Table 2. The symbols in the table are as follows.

TFE: tetrafluoroethylene, HFP: hexafluoropropylene, CTFE: chlorotrifluoroethylene, EA: ethyl acrylate, n-BuA: n-
Butyl acrylate.

Table 2

Claims (1)

[Claims] Obtained from a monomer represented by the general formula ▲ Numerical formulas, chemical formulas, tables, etc. The polymer (B) obtained from 100 parts by weight of the polymer (A) and a monomer mainly composed of vinylidene fluoride is expressed by the general formula ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (In the formula, R_3 is a hydrogen atom or Copolymer (C) 1-100 obtained by reacting with a monomer represented by a methyl group (R_4 represents an alkyl group having 1 to 10 carbon atoms)
A thermoplastic resin composition consisting of parts by weight.