JPH07228736A - Resin composition and molded object obtained therefrom - Google Patents

Abstract

PURPOSE:To obtain a resin composition and a molding thereof which have moderate flexibility, are excellent in flame retardancy and compression set, and are advantageous in cost by mixing a crystalline chlorinated polyolefin with a thermoplastic elastomer and a metal hydroxide. CONSTITUTION:100 pts.wt. resin composition comprising a crystalline chlorinated polyolefin (A), and a thermoplastic elastomer (B) in a proportion of 10/90 to 90/10 by weight is mixed with 20-30 pts.wt. metal hydroxide (C). Examples of the ingredient (A) include a chlorinated polyethylene and a chlorinated ethylene/propylene copolymer each having a chlorine content of 20-45wt.% and a heat of crystal fusion as measured by DSC of 3-25cal/g. Examples of the ingredient (B) include polyolefin elastomers. The ingredient (C) may be a hydroxide of a Group II or III metal of the Periodic Table, e.g. magnesium or aluminum, the hydroxide having an average particle diameter of 0.5-150mum.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention has appropriate flexibility,
The present invention relates to a resin composition excellent in flame retardancy and compression set, and also advantageous in cost, and a molded product thereof.

[0002]

2. Description of the Related Art Conventionally, materials such as soft vinyl chloride, chloroprene rubber (CR) or ethylene propylene rubber (EPM, EPDM) have been used for building gaskets. In recent years, with respect to the gasket material, flame resistance,
In particular, there is an increasing demand for improved ignitability and cost reduction for sui.

[0003]

However, in response to these requirements, soft vinyl chloride has been attempted to improve the ignitability, but there is a problem in the strength at the time of combustion, and a satisfactory one has not been obtained. Further, since CR and EPDM are used as a crosslinked rubber, a crosslinking step is required,
The current situation is that we cannot expect a significant cost reduction in productivity. The present invention has been made in view of such a situation, and is excellent in flame retardancy and compression set, and also to provide a cost-effective resin composition and a building gasket which is a molded body thereof. To aim.

[0004]

As a result of intensive studies, the present inventors have found that the above object can be achieved by using a specific chlorinated polyolefin in combination with a thermoplastic elastomer, and based on this finding As a result, the present invention has been completed. That is, the present invention provides (A) a crystalline chlorinated polyolefin, (B) a thermoplastic elastomer, and (C).
A resin composition comprising a resin composition comprising a metal hydroxide is provided. Hereinafter, the present invention will be specifically described.

The crystalline chlorinated polyolefin (A) in the present invention is obtained by chlorinating polyolefin powder or particles in an aqueous suspension, and is required to have crystallinity. Amorphous chlorinated polyolefin is inferior in compression set and is not preferred. The chlorine content of the crystalline chlorinated polyolefin is usually 15 to 50% by weight, preferably 20 to 45% by weight, particularly 30 to 4% by weight.
0 wt% is preferred. If the chlorine content is less than 15% by weight, flame retardancy becomes insufficient. On the other hand, if it exceeds 50% by weight, rubber elasticity tends to be poor.

As the above-mentioned polyolefin, ethylene homopolymer, ethylene and α-containing 3 to 12 carbon atoms
Examples thereof include copolymers with olefins. The copolymerization ratio of α-olefin is usually 40% by weight or less, preferably 30% by weight or less. Specific examples of the crystalline chlorinated polyolefin include crystalline chlorinated polyethylene, crystalline chlorinated ethylene-propylene copolymer, crystalline chlorinated ethylene-propylene-diene copolymer and the like. Among these, the chlorine content is 20 to 45% by weight and the heat of crystal fusion by the DSC method is 3 to 25 cal / g.
Which is a crystalline chlorinated polyethylene or a crystalline chlorinated ethylene-propylene copolymer is preferred.

Here, the DSC method is a method for quantifying a thermal change that occurs when a sample is heated and lowered at a constant speed as a heat energy amount, and is a differential scanning calorimeter (Differential scanning calorimetry).
ialScanning Calorimetry) method.
When the heat of crystal fusion by the DSC method is less than 3 cal / g, the compression set is lowered as described above, while on the other hand, it is 25 cal.
If it exceeds / g, flexibility is insufficient, which is not preferable.

The (B) thermoplastic elastomer (hereinafter referred to as "TPE") in the present invention is a polymeric material which exhibits rubber-like elasticity at room temperature but is plasticized and moldable at high temperature.
The TPE can be molded by an ordinary plastic molding machine and does not require a long vulcanization step such as rubber,
It is possible to obtain a material having a sufficient strength without adding a reinforcing material and having a wide range of physical properties from a soft rubber to a plastic region. The TPE is structurally composed of a soft segment (hereinafter referred to as "SS") and a hard segment (hereinafter referred to as "H").
S)), and generally, styrene-based, polyolefin-based, polyvinyl chloride-based, urethane-based, polyester-based, polyamide-based, etc. have been developed depending on the type of HS.

Of these TPEs, a polyolefin-based elastomer is particularly preferably used. In the polyolefin elastomer, HS is made of crystalline polyolefin and SS is made of ethylene rubber. H
Examples of S include polyethylene and polypropylene, and examples of SS include ethylene propylene rubber (EPR),
Examples thereof include ethylene propylene diene rubber (EPDM).

In addition, when producing these elastomers, a method is proposed in which a crosslinking agent (for example, an unsaturated monomer and an organic peroxide) is added and a dynamic heat treatment (for example, melt kneading) is performed to partially crosslink. However, these elastomers can also be preferably used.

The composition ratio of the component (B) in the resin composition comprising the crystalline chlorinated polyolefin (A) and the thermoplastic elastomer (B) of the present invention is 10 to 90% by weight, and 20 to 80% by weight. It is particularly preferably 30 to 60% by weight. If the proportion of the component (B) is less than 10% by weight, the heat resistance will decrease. On the other hand, if it exceeds 90% by weight, flame retardancy and compression set are lowered, which is not preferable.

The metal hydroxide in the present invention may be a metal hydroxide of Group II or III of the periodic table. Specific examples include magnesium hydroxide, aluminum hydroxide, calcium hydroxide and the like.
Among these, magnesium hydroxide and aluminum hydroxide are preferable. The average particle size of these hydroxides is usually 0.5 to 150 μm, preferably 0.5 to 120 μm. The mixing ratio of the metal hydroxide is 20 to 20 parts by weight based on 100 parts by weight of the total amount of the components (A) and (B).
300 parts by weight, preferably 30 to 250 parts by weight,
Particularly, 50 to 200 parts by weight is suitable. If the compounding ratio of the metal hydroxide is less than 20 parts by weight, flame retardancy is insufficient. On the other hand, if it exceeds 300 parts by weight, the workability is deteriorated, which is not preferable.

If desired, a softening agent may be added to the composition of the present invention. Examples of the softening agent include mineral oils such as paraffin oil and naphthenic oil, and plasticizers such as phthalate ester and phosphate ester. Among them, tributyl phosphate, tri-2-ethylhexyl phosphate, tricresyl phosphate are available. Phosphate plasticizers such as trixylenyl phosphate are preferred.

In order to obtain the composition of the present invention, conventionally known mixing methods, for example, dry blending using a mixer such as a Henschel mixer, and then kneading using an open roll, a Banbury mixer, a kneader, an extruder, etc. The method may be appropriately used. Further, the composition of the present invention may optionally contain various conventional additives such as stabilizers, lubricants, ultraviolet absorbers, antistatic agents, release agents, dyes, pigments,
Various fillers and the like can be added.

[0015]

EXAMPLES The present invention will now be described in more detail with reference to examples. The compression set was based on JIS A5756, and was heat-compressed at 70 ° C. for 22 hours. Hardness is JI
Hardness was measured according to S A5756. Flame time is J
According to IS A1321, a building material equipment test furnace (manufactured by Toyo Seiki Seisaku-sho, Ltd.) was used to measure a sample having a diameter of 45 mm and a thickness of 5 mm at a temperature of 500 ° C. The thermal stability was visually evaluated by using a Labo Plastomill manufactured by Toyo Seiki Co., Ltd. under the conditions of 180 ° C. and 50 rotations / minute for 5 minutes, and the presence or absence of discoloration was visually evaluated. Indicated by.

The crystalline chlorinated polyolefin has a chlorine content of 35% by weight and a DSC crystal heat of fusion of 10 ca.
Chlorinated polyethylene (hereinafter referred to as "CPE1") of 1 / g and propylene content of 22% by weight, chlorine content of 28% by weight, chlorinated ethylene-propylene copolymer having a DSC crystal heat of fusion of 15 cal / g (hereinafter " CEPR "
Was used). For comparison, chlorinated polyethylene having a chlorine content of 35% by weight and a DSC crystal heat of fusion of 0 cal / g (hereinafter referred to as "CPE3") was used.

The thermoplastic elastomer has an A hardness of 65.
Olefin-based elastomer (Oleflex T210GN manufactured by Showa Denko KK) (hereinafter referred to as "TPE1")
An olefin elastomer having an A hardness of 70 (Oleflex T310GN, manufactured by Showa Denko KK) (hereinafter referred to as "TPE2") was used.

The metal hydroxide has an average particle size of 1 μm.
m, aluminum hydroxide having a specific surface area of 5 m ² / g (hereinafter referred to as “ALH”) and magnesium hydroxide having an average particle size of 0.6 μm and a specific surface area of 8 m ² / g (hereinafter referred to as “MGH”).
Was used). Further, tricresyl phosphate (manufactured by Daiichi Kagaku Co., Ltd.) was used as a softening agent.

Examples 1 to 6 and Comparative Examples 1 to 5 Crystalline chlorinated polyolefins whose types and amounts are shown in Table 1, thermoplastic elastomers, metal hydroxides and softeners, and butyltin malate as a stabilizer. 1 part by weight and tetra (methylene-3- as an antioxidant
0.5 parts by weight of (3 ′, 5′-di-t-butyl-4′-hydroxyphenyl) propionate) methane was added at 150 ° C.
The composition was obtained by melt-kneading with a kneader at the temperature of.
A test piece was prepared from the obtained composition at a temperature of 150 ° C. using a press molding machine. The compression set, hardness and ignition time of each test piece were measured. The results obtained are shown in Table 1. In addition, the thermal stability of each composition was evaluated. The results are shown in Table 1.

[0020]

[Table 1]

[0021]

Industrial Applicability The resin composition of the present invention and the molded product thereof have appropriate flexibility, excellent flame retardancy and compression set, and are advantageous in terms of cost. It is useful as a building gasket.

Claims (6)

[Claims] 1. A crystalline chlorinated polyolefin (A),
A resin composition comprising (B) a thermoplastic elastomer and (C) a metal hydroxide. 2. (A) Crystalline chlorinated polyolefin 10
~ 90 wt% and (B) thermoplastic elastomer 90 ~
Resin composition consisting of 10% by weight (however, (A) +
The resin composition according to claim 1, wherein 20 to 300 parts by weight of the metal hydroxide (C) is mixed with 100 parts by weight of (B) = 100% by weight. 3. A chlorinated polyethylene or chlorinated ethylene-propylene copolymer having (A) a crystalline chlorinated polyolefin having a chlorine content of 20 to 45% by weight and a heat of crystal fusion of 3 to 25 cal / g according to the DSC method. The resin composition according to claim 1 or 2, which is a united body. 4. The resin composition according to claim 1, wherein the thermoplastic elastomer (B) is a polyolefin-based elastomer. 5. A packing material obtained by molding the resin composition according to claim 1. 6. A building gasket obtained by molding the resin composition according to claim 1.