JP2565554B2 - Vinyl chloride polymer alloy - Google Patents

Description

TECHNICAL FIELD The present invention is excellent in transparency, tint resistance, heat distortion resistance, warm water whitening resistance, impact resistance, workability, and the like and is flame retardant. For example, the present invention relates to a vinyl chloride polymer alloy useful as a material for various synthetic resin moldings such as nameplates.

Conventional technology Vinyl chloride polymers, which are widely used as molding materials, have many advantages such as flame retardancy, chemical resistance, and processability, but have the disadvantage of poor weather resistance and heat distortion resistance. ing. On the other hand, an acrylic polymer such as a methyl methacrylate polymer can be formed into a molded article excellent in transparency, heat distortion resistance, etc., but has a drawback that it is flammable and inferior in chemical resistance.

However, among the vinyl chloride-based polymer and the acrylic-based polymer, the methyl methacrylate-based polymer shows good compatibility with the solubility parameter being approximated, and therefore, according to the polymer alloy composed of the mixture of the two, It is presumed that it is possible to obtain a molded product having excellent resin properties by complementing the advantages and disadvantages of the above.

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention However, a molded product obtained from a polymer alloy of such a vinyl chloride-based polymer and a methyl methacrylate-based polymer is inferior in impact resistance and is impacted during handling or use. In that case, there is a problem that cracks and chips are likely to occur, workability is poor, and cracks occur in cutting by pressing and the like.

As a general compounding agent that improves impact resistance and workability, acrylic processing aids and impact strength modifiers, MB
S resins and the like are known, but in those obtained by adding these to a mixture of the above vinyl chloride polymer and methyl methacrylate polymer, the advantage of the memory methacrylate polymer that is colorless and transparent is impaired, and the molded product is It becomes yellowish or cloudy and has low resistance to warm water whitening, so that the advantages of both polymers cannot be fully exerted.

In view of the above situation, the present invention has a vinyl chloride-based polymer and a methyl methacrylate-based polymer as main polymers, and the advantages of both polymers are fully utilized together, and the impact resistance and processability are improved. It is an object of the present invention to provide a vinyl chloride polymer alloy capable of obtaining an excellent molded product.

Means for Solving the Problems The inventors of the present invention have conducted extensive studies to achieve the above object, and as a result, a vinyl chloride copolymer and a methyl methacrylate copolymer, which are main polymers, have a specific ratio. In this case, ethylene vinyl acetate
It was clarified that by adding a specific amount of a vinyl chloride graft copolymer, the advantages of both main polymers are not impaired, and the impact resistance and processability of the molded product are greatly improved, and the present invention was achieved. It was

That is, the vinyl chloride polymer alloy according to the present invention is an ethylene vinyl acetate-vinyl chloride graft copolymer based on 100 parts by weight of a main polymer composed of a vinyl chloride polymer of 60 to 80% by weight and the remaining methyl methacrylate polymer. It comprises 3 to 20 parts by weight of a polymer and 1 to 3 parts by weight of a stabilizer.

In the present invention, the ethylene vinyl acetate-vinyl chloride graft copolymer has a vinyl vinyl acetate / vinyl chloride weight ratio of 5/95 to 50/50, and the stabilizer is an organotin mercapto stabilizer. Each of the configurations containing the main component is a preferred embodiment.

Specific Structure and Action of the Invention A vinyl chloride polymer (hereinafter, abbreviated as PVC), which is one of the components constituting the main polymer of the present invention, has vinyl chloride as a main component of a monomer, Particularly, vinyl chloride preferably accounts for 80% by weight or more of all monomers,
It may be any of a homopolymer of vinyl chloride, a copolymer of vinyl chloride and another vinyl-based monomer copolymerizable therewith, and a mixture of two or more thereof. Examples of other vinyl monomers of the above copolymer include ethylene, propylene, vinyl acetate, alkyl vinyl ether and the like. Further, the degree of polymerization of these vinyl chloride polymers is 600 to 1
100 is good.

On the other hand, the methyl methacrylate polymer (hereinafter referred to as PMMA), which is the other component constituting the main polymer,
Methyl methacrylate is the main component of the monomer, and it is particularly preferable that methyl methacrylate accounts for 70% by weight or more of the total monomers. Homopolymer of methyl methacrylate, methyl methacrylate and other methacrylic acid esters. Any of a copolymer with an acrylic acid ester or other copolymerizable vinyl-based monomer, and a mixture of two or more thereof may be used.

The mixing ratio of PVC and PMMA in the main polymer should be in the range in which PVC in the main polymer occupies 60 to 80% by weight, and when the amount of PVC is less than 60% by weight, ethylene vinyl acetate-vinyl chloride graft described later. Even if a copolymer is blended, impact resistance and workability become insufficient and combustibility appears, and conversely, when the amount of PVC exceeds 80% by weight, transparency and heat resistance change deteriorate.

Ethylene vinyl acetate-vinyl chloride graft copolymer (hereinafter abbreviated as EVA / VC) fulfills the function of significantly improving impact resistance and workability by blending it with a main polymer, and it is a common acrylic resin. It has an excellent feature that it does not impair the original advantages of the main polymer such as the color-fastness of the molded product, unlike the processing aids and impact strength modifiers of the system or MBS resin.

Such EVA / VC is not particularly limited, but the weight ratio of ethylene vinyl acetate / vinyl chloride is 5/95 to 50/50.
Graft copolymers in the range of are preferred. That is, if the ethylene vinyl acetate component is too small, the effect of improving impact resistance and workability becomes insufficient, and conversely, if the ethylene vinyl acetate component is too large, the transparency of the molded article decreases.

And, the blending amount of EVA / VC should be in the range of 3 to 20 parts by weight with respect to 100 parts by weight of the main polymer composed of PVC and PMMA. When the blending amount is less than 3 parts by weight, the use effect is sufficient. On the contrary, when it exceeds 20 parts by weight, the transparency and color-fastness of the molded product are deteriorated and the resistance to warm water whitening is deteriorated.

As the stabilizer, any of various heat or light stabilizers conventionally blended in a vinyl chloride polymer composition can be used. Among them, an organotin stabilizer is preferable, and dibutyltin is particularly preferable. An organotin mercapto-based stabilizer such as a mercapto compound is recommended because it exhibits an excellent effect on hot water whitening resistance. It should be noted that one or more stabilizers may be used in combination with the organotin mercapto stabilizer. The amount of such a stabilizer to be added should be 1 to 3 parts by weight with respect to 100 parts by weight of the main polymer. If the amount is too small, the use effect will be insufficient, and if it is too large, various types of molded products will be obtained. There is a fear of adversely affecting the characteristics.

The polymer alloy of the present invention is made of the above-mentioned PVC and PMM.
It contains a main polymer consisting of A, EVA / VC, and a stabilizer as essential components, but other than these components, various additives such as fillers, lubricants, plasticizers, processing aids, and colorings depending on the application and purpose. Auxiliary agents may be added appropriately.

Example Hereinafter, an example of the present invention will be described in comparison with a comparative example. The components used in the examples and comparative examples are as follows.

PVC: Nippon Zeon Co., Ltd. trade name "103EP-8" (average degree of polymerization 800, vinyl chloride homopolymer) PMMA: Sumitomo Chemical Co., Ltd. trade name "SUMIPEX BE
X "(weight average molecular weight: 140,000) EVA / VC: Sumitomo Chemical Co., Ltd. product name" Sumigraft, GE "(graft copolymer with an ethylene vinyl acetate content of 35% by weight) MBS resin: Kanegafuchi Chemical Industry Company name Kaneace B-31 HI-MMA: Methyl methacrylate impact strength modifier (trade name HYPET IRH70-001 manufactured by Mitsubishi Rayon Co.) Stabilizer A: Dibutyltin mercapto stabilizer (Katsuda Kako Co., Ltd. Trade name TM-180J) Stabilizer B: dibutyltin malate stabilizer (trade name KS-4C manufactured by Kyodo Chemical Co., Ltd.) Examples 1 to 6 Roll rolls according to a standard method using the compounded compositions shown in the table below. It was formed into a sheet having a thickness of 1.0 mm by a ding operation.

Comparative Examples 1 to 7 Molded in the same manner as in Examples except that the compounding composition was as shown in the table below.

For each of the sheet-shaped molded products obtained in the above Examples and Comparative Examples, the properties of transparency, warm water whitening resistance, heat distortion resistance, impact resistance, workability, color resistance, and flammability were examined. The results shown in the table below were obtained. The measuring method and evaluation of each measurement item are as follows.

[Transparency] The total light transmittance based on JIS K6745 is shown.

[Hot water whitening resistance] Total light transmittance was measured after immersion in warm water of 65 ° C for 200 hours.

[Heat resistance deformation] CB type soft temperature based on JIS K6745 was measured.

[Impact resistance] DuPont impact strength (W = 300g, R = 1 / 4inc
It was evaluated in h).

[Workability] At the time of cutting by push-cutting, when almost no cracks were recognized, "○" was evaluated, and when cracks were significantly recognized, "x" was evaluated.

[Color tint resistance] By visual observation, a colorless and transparent sheet-like molded product whose color tone is close to an acrylic color is "○", a transparent but yellowish one is "△", and it is cloudy. The thing was evaluated as "x".

[Combustibility] Combustibility based on UL standard (UL94, 1 m / m) was measured.

From the results shown in the above table, the molded products obtained from the polymer alloys (Examples 1 to 6) according to the present invention are good in all of the various characteristics, and the use of the organotin mercapto-based stabilizer as the stabilizer results in It is clear that the warm water whitening property becomes particularly good. In contrast, the main polymer PVC
If too much, transparency, warm water whitening resistance, heat distortion resistance,
On the other hand, if PVC is too low, impact resistance, workability, and flame retardancy
If VA / VC is not used or is too small, impact resistance and workability will deteriorate, and if EVA / VC is too much, transparency, warm water whitening resistance, tint resistance, and flame retardancy will all deteriorate. I understand. Also, when MBS resin or HI (high impact) -MMA is used instead of EVA / VC, transparency, warm water whitening resistance, and tint resistance are reduced even though impact resistance and processability are improved. I understand that

Effect of the Invention The vinyl chloride polymer alloy according to the present invention is made of PVC.
A specific amount of EV to the main polymer with a specific ratio of PMMA and PMMA
As it is a blend of A / VC, the original polymer's original advantages are utilized, and it has excellent properties such as transparency, warm water whitening resistance, heat distortion resistance, color tint resistance, and flame retardancy. A molded product having excellent impact resistance and processability can be provided, and it is extremely useful as a material for a wide range of synthetic resin molded products including various uses which could not be put to practical use with conventional polymer alloys of this type.

Further, in the present invention, by selecting an EVA / VC having a weight ratio of ethylene vinyl acetate / vinyl chloride of 5/95 to 50/50, impact resistance and impact resistance can be obtained without impairing the transparency of the molded article. The workability improving effect can be most effectively exhibited. Further, by selecting a stabilizer containing an organotin mercapto-based stabilizer as a main component, the hot water whitening resistance of the molded article becomes particularly good.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical display location C08L 51:06) (56) References JP-A-59-159845 (JP, A) JP-A-61 -14246 (JP, A) JP-A-52-17554 (JP, A) JP-A-59-8745 (JP, A) JP-B-49-37418 (JP, B1)

Claims (3)

(57) [Claims] 1. A main polymer 10 comprising 60 to 80% by weight of a vinyl chloride polymer and the balance of a methyl methacrylate polymer.
A vinyl chloride polymer alloy comprising 3 to 20 parts by weight of an ethylene vinyl acetate-vinyl chloride graft copolymer and 1 to 3 parts by weight of a stabilizer, relative to 0 parts by weight. 2. The ethylene vinyl acetate / vinyl chloride weight ratio of the ethylene vinyl acetate-vinyl chloride graft copolymer is
The vinyl chloride polymer alloy according to claim 1, which has a ratio of 5/95 to 50/50. 3. The vinyl chloride polymer alloy according to claim 1, wherein the stabilizer comprises an organotin mercapto stabilizer as a main component.