JPH0893352A - Weatherstrip - Google Patents

Abstract

PURPOSE: To improve creep resistance, permanent compression set and heat distortion resistance by a method wherein a chlorinated vinyl chloride resin is used as a rigid resin section, joined with a soft vinyl chloride resin composition and compounded at a specific rate. CONSTITUTION: A rigid resin is formed from the mixture of a chlorinated vinyl chloride resin or the chlorinated vinyl chloride resin containing the not less than 20wt.% chlorinated vinyl chloride resin and a vinyl chloride resin. A soft resin composition is obtained from 100 pt.wt. vinyl chloride resin, 10-400 pt.wt. rubber substance containing a not less than 30wt.% tetrahydrofuran insoluble crosslinking component, and 30-300 pt.wt. plasticizer. The soft resin composition is compounded with the rigid resin, and the mean degree of polymerization of a vinyl chloride polymer before chlorination is set to be 400-1500, and the degree of chlorination is 60-70wt.% at that time. The mean degree of polymerization of the vinyl chloride resin used as the soft resin composition is set to be 700-8000.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a weather strip composed of a hard resin and a soft resin composition and having excellent compression set and heat distortion resistance.

[0002]

2. Description of the Related Art Soft vinyl chloride resin, vulcanized rubber and the like are used as materials for weather strips for keeping airtightness of automobiles, buildings and the like. These weather strips may be formed by molding a soft vinyl chloride resin or vulcanized rubber alone into a desired shape and fixing it to a supporting substrate such as metal or hard synthetic resin with a screw or an adhesive. Many. In addition, in recent years, an invention of a method of manufacturing a gasket by replacing a metal substrate with a hard vinyl chloride resin and coextruding with a soft resin is proposed in Japanese Patent Publication No. 4-82034, but the hard support substrate is a vinyl chloride resin. Therefore, there is a drawback that the heat distortion resistance is inferior, and when the gasket is used in a high temperature atmosphere, the entire gasket is deformed, and the durability as a gasket is also inferior, which is not satisfactory.

[0003]

DISCLOSURE OF THE INVENTION The inventors of the present invention have earnestly studied for the purpose of obtaining a weather strip excellent in heat distortion resistance, creep resistance and compression set, and as a result, chlorinated vinyl chloride was added to the hard resin portion. By using a resin, it is easy to bond with a soft vinyl chloride resin composition and the weather strip obtained by combining it exhibits excellent performance as a weather strip in heat distortion resistance, creep resistance and compression set. This has led to the completion of the present invention. That is, an object of the present invention is to provide a weather strip excellent in creep resistance, compression set and heat distortion resistance.

[0004]

SUMMARY OF THE INVENTION The gist of the present invention, however, is to provide a chlorinated vinyl chloride resin or a chlorinated vinyl chloride resin containing 20% by weight or more of a chlorinated vinyl chloride resin and a vinyl chloride resin. A hard resin made of a mixture,
Rubber substance containing 100 parts by weight of vinyl chloride resin and 30% by weight or more of tetrahydrofuran-insoluble crosslinking component 10
It exists in a weather strip formed by combining a soft resin composition containing 400 parts by weight and 30 to 300 parts by weight of a plasticizer as main components.

The present invention will be described in detail. The chlorinated vinyl chloride resin, which is a hard resin as one component of the weather strip of the present invention, is produced by a method of post-chlorinating a vinyl chloride resin. The post-chlorination method includes, for example, a solution method in which a vinyl chloride resin is dissolved in ethane tetrachloride and reacted with chlorine gas, a dry method in which the vinyl chloride resin is reacted with chlorine gas while heating or irradiating light, and A liquid chlorine method in which chlorine gas is dissolved in a solvent under pressure to react with a vinyl chloride resin, or a vinyl chloride resin is suspended in a hydrochloric acid solution, and a water suspension method in which chloroform is added and chlorine gas is passed may be mentioned. The chlorinated vinyl chloride resin used in 1. may be chlorinated by any method.

It is desirable that the chlorinated vinyl chloride resin has an average degree of polymerization of the vinyl chloride resin before chlorination in the range of 400 to 1500 from the viewpoint of workability in producing a weather strip. The chlorination rate after chlorination is 60-
It is preferably in the range of 70% by weight. Chlorination rate is 60
If it is less than wt%, the effect of improving heat distortion resistance is small,
If it exceeds 70% by weight, workability tends to be poor.

The above-mentioned vinyl chloride-based resin used for producing a chlorinated vinyl chloride resin is a suspension polymerization method, a bulk polymerization method, a fine suspension weight method, in which vinyl chloride or a mixture of vinyl chloride and a comonomer copolymerizable therewith is used. All of those produced by ordinary methods such as the legal method or emulsion polymerization method are used.
Examples of comonomers include vinyl acetates such as vinyl acetate, vinyl propionate and vinyl laurate, acrylic acid esters such as methyl acrylate, ethyl acrylate and butyl acrylate, methacrylic acid esters such as methyl methacrylate and ethyl methacrylate, and dibutyl maleate. , Maleates such as diethyl maleate, fumarates such as dibutyl fumarate, diethyl fumarate, vinyl ethers such as vinyl methyl ether, vinyl butyl ether, vinyl octyl ether, cyanation of acrylonitrile, methacrylonitrile, etc. Vinyls, ethylene, propylene,
Α-olefins such as styrene, vinylidene chloride, vinylidene halide other than vinyl chloride such as vinyl bromide, vinyl halides, diacryl phthalate, and polyfunctional monomers such as ethylene glycol dimethacrylate, and of course, The comonomers are not limited to those described above. The comonomer content is 30% by weight or less, preferably 20% by weight or less in the constituent components of the vinyl chloride resin.

As the hard resin, a mixture of a chlorinated vinyl chloride resin and a vinyl chloride resin produced by the above method may be used. The mixing ratio of the chlorinated vinyl chloride resin and the vinyl chloride resin needs to include at least 20% by weight of the former, preferably 50% by weight.
The above content, especially 70% by weight or more, is desirable. If the amount of the chlorinated vinyl chloride resin is less than 20% by weight, the effect of improving the heat distortion resistance becomes insufficient. Various additives such as a stabilizer, a lubricant, an antioxidant, an ultraviolet absorber, a foaming agent, and a pigment may be added to the hard resin, if necessary.

The soft resin composition, which is an essential constituent element of the weather strip of the present invention, comprises a vinyl chloride resin and a tetrahydrofuran (hereinafter referred to as THF) insoluble cross-linking component.
The main component is a rubber substance and a plasticizer containing 0% by weight or more. The vinyl chloride resin is not particularly limited as long as it is manufactured by the above-mentioned method, but the processability of the soft resin composition, the moldability or the creep resistance of the weather strip, and the heat distortion resistance are not limited. Considering this, the average degree of polymerization is in the range of 700 to 8000, preferably 1300 to 5
000, and particularly preferably in the range of 1500 to 4000.

A rubber substance having 30% by weight or more of a cross-linking component insoluble in THF, which is one component of the soft resin composition, is an acrylonitrile-butadiene rubber (nitrile rubber, NB
R), methylmethacrylate-butadiene-styrene rubber (MBS), acrylic rubber (AR), styrene-butadiene rubber (SBR), chloroprene rubber (CR), ethylene-vinyl acetate rubber (EVA), urethane rubber (U
Various rubbers such as R) are listed, and it is particularly preferable to use NBR or AR. The THF-insoluble cross-linking component of these rubber substances has a content of 30% by weight or more in the rubber molecule by adding a polyfunctional monomer to the polymerization system at the time of production or performing a cross-linking treatment with an organic peroxide after the production of rubber. ,
It is preferably produced by introducing 50% by weight or more of a crosslinked structure. Among these, it is desirable to use a compound having a crosslinked structure by adding a polyfunctional monomer at the time of producing a rubber substance. If the amount of the THF-insoluble crosslinking component is less than 30% by weight, it becomes difficult to sufficiently exert the effect of improving the compression set.

% By weight of the THF-insoluble cross-linking component
With respect to the above, 0.5 g of a sample is put into 30 ml of THF with stirring, and the mixture is left at room temperature for 24 hours, and the supernatant THF is removed. It is a value calculated by measuring the weight of the filtration residue filtered with glass fiber filter paper. Therefore, the compounding ratio of the rubber substance is in the range of 10 to 400 parts by weight, preferably 20 to 250 parts by weight, relative to 100 parts by weight of the vinyl chloride resin. 1
If it is less than 0 parts by weight, the effect of improving the compression set will be poor, and if it is more than 400 parts by weight, the moldability will be poor.

The soft resin composition is used in combination with a plasticizer to soften the composition, facilitate kneading and processing, and serve to improve compression set. The plasticizer is not particularly limited, and examples thereof include phthalate ester plasticizers such as di-2-ethylhexyl phthalate, di-n-octyl phthalate, diisodecyl phthalate, dibutyl phthalate, dihexyl phthalate; dioctyl adipate, dioctyl. Linear dibasic acid ester plasticizers such as sebacate; trimellitic acid ester plasticizers; polyester polymer plasticizers; epoxy plasticizers such as epoxidized soybean oil, epoxidized linseed oil, and liquid epoxy resin; tri Phenyl phosphate, trixylyl phosphate,
Phosphate ester-based plasticizers such as tricresyl phosphate may be used, and one or more of these may be mixed and used.

Although the amount of the plasticizer used varies depending on the type and addition amount of the vinyl chloride resin, the rubber substance, etc., the presence or absence of the filler, etc., it is 30 to 300 parts by weight per 100 parts by weight of the vinyl chloride resin. , Preferably 40-200
It is appropriately selected from the range of parts by weight. The soft resin composition is
The compression set characteristics can be improved by using a crosslinking agent together. As the cross-linking agent, an organic peroxide, an inorganic peroxide, a metal oxide, sulfur, a sulfur-based vulcanization accelerator, a vulcanization accelerator, a quinone-based cross-linking agent, an oxime-based cross-linking agent, an amine-based cross-linking agent, etc. The crosslinking agent used for vulcanization and crosslinking is used, and a crosslinking accelerator can be used together. The amount of the crosslinking agent used is 0.01 to 100 parts by weight of the vinyl chloride resin.
A range of 10 parts by weight is suitable.

It is desirable to add a filler to the soft resin composition as long as the compression set is not impaired. The filler has the function of absorbing an excessive amount of plasticizer and facilitating kneading and molding. Examples of the filler include carbon black, calcium carbonate, titanium oxide, talc, aluminum hydroxide, magnesium hydroxide, hydrotalcite,
Examples include clay, silica, white carbon and the like. The addition amount of the filler is selected from the range of 500 parts by weight or less with respect to 100 parts by weight of the vinyl chloride resin, and is preferably in the range of 10 to 200 parts by weight in consideration of various physical properties of the soft resin composition. If the addition amount of the filler is too small, the effect of improving kneading and moldability is small, and if it is more than 500 parts by weight, the moldability tends to deteriorate, and it is economical to add it within a range that does not impair the moldability. It is also desirable from the viewpoint of sex.

Further, the extrusion moldability can be improved by adding an acrylic resin to the soft resin composition. The acrylic resin is obtained by polymerizing acrylic acid or its derivative, and examples thereof include polymers or copolymers of acrylic acid, acrylic acid ester, acrylamide, acrylonitrile, methacrylic acid, methacrylic acid ester and the like. Particularly, in the soft resin composition used in the present invention, a copolymer of methyl methacrylate and alkyl acrylate, the former is 60% by weight or more, preferably 70 to 90% by weight and the latter is 40% by weight or less, It is suitable to use one in the range of 30 to 10% by weight. The amount of acrylic resin added is 10
0 to 30 parts by weight, preferably 2
It is preferably in the range of ˜20 parts by weight.

Further, the soft resin composition may contain a stabilizer, a lubricant, an antioxidant, an ultraviolet absorber, a foaming agent, if necessary.
You may mix | blend various additives, such as a flame retardant, a pigment, an impact modifier, a thermoplastic resin or rubber other than the above. Examples of the thermoplastic resin and rubber include methyl methacrylate-
Butadiene-styrene rubber, acrylic rubber, butadiene rubber, styrene-butadiene rubber, nitrile rubber, acrylonitrile-butadiene-styrene rubber, isoprene rubber, chloroprene rubber, ethylene-propylene rubber,
Examples thereof include ethylene-vinyl acetate, thermoplastic polyurethane, nylon and the like.

The soft resin composition, which is a constituent feature of the present invention, comprises a vinyl chloride resin, a rubber substance containing a THF-insoluble crosslinking component and a plasticizer, and a predetermined amount of various additives such as an acrylic resin and a filler. Or put it in a kneader and put it at 100
It is produced by a method of mixing and kneading while heating to a temperature of 230 ° C, preferably 130 ° C to 230 ° C. The soft resin composition is preferably produced, for example, by the following method from the viewpoint of operation or obtaining a uniform kneading composition.
That is, first, a blend consisting of a vinyl chloride resin and a plasticizer and, if necessary, an acrylic resin is dry blended in advance, and then the dry blended product is a rubber substance containing a THF-insoluble crosslinking component and, if necessary, a crosslinking agent. , And other additives such as a filler are mixed and kneaded while being heated to a temperature of 100 to 230 ° C.

The device used for mixing the above-mentioned compounding components may be any device as long as it can mix them substantially uniformly, and examples thereof include a Henschel mixer, a ribbon blender, a planetary mixer and the like, and for kneading the mixture. , Eg extruders, rolls, Banbury mixers,
An apparatus such as a kneader capable of kneading under a shearing force while heating is used. In particular, it is preferable to use a closed kneading machine such as a Banbury mixer, an intensive mixer, a pressure kneader or the like, or a co-directional twin-screw extruder because the kneading effect is large.

The weather strip of the present invention is a composite of the above-mentioned hard resin and soft resin compositions. The method of compounding is, for example, a method of extrusion coating the above-mentioned soft resin composition on the whole or a part of the surface of a deformed extruded hard molded article such as a strip or a bar, using a plurality of extruders for the hard resin and the soft resin composition. Coextrusion, various methods such as a method of compounding in or near the extrusion die, a molded product is manufactured from each of the hard resin and the soft resin composition by various molding methods, and both are bonded by heat welding or an adhesive. Adopted.

In particular, a hard resin is formed into a strip shape, and the soft resin composition is formed at the end of the strip surface or the strip surface so as to intersect, for example, T-shape or L-shape in section, that is, a strip-shaped molded product of hard resin. A long weather strip in which the strip-shaped end portions of the strip-shaped molded article of the soft resin composition are welded or adhered to the strip-shaped surface of the strip-shaped surface, or the ends of the strip-shaped molded articles formed from the hard resin and the soft resin composition. The long weatherstrip, whose part is welded or adhered in an L-shape, is applied to vehicles such as automobiles and buildings.

[0021]

EFFECTS OF THE INVENTION Since the weather strip of the present invention has a hard portion formed of a chlorinated vinyl chloride resin, it has excellent heat distortion resistance, and thermal deformation of the soft resin composition combined with the hard resin occurs. Moreover, the excellent creep resistance and compression set of the soft resin composition are retained, and the effect can be maintained for a long period of time.

[0022]

EXAMPLES Next, the weather strip of the present invention will be described in detail with reference to examples, but the present invention is not limited to the following examples without departing from the gist thereof.

Examples 1 to 5 and Comparative Examples 1 and 2 <Preparation of Hard Resin> Chlorinated vinyl chloride resin having a chlorination rate of 64.5% by weight obtained by post-chlorinating a vinyl chloride resin having an average degree of polymerization of 800. (C-PVC) and average degree of polymerization 110
No. 0 vinyl chloride resin (PVC-1) was mixed in the ratio shown in Table 1, and 3 parts by weight of a lead-based stabilizer, 5 parts by weight of calcium carbonate and 4 parts by weight of a composite lubricant were mixed in a 20-liter Henschel mixer. And the mixture was stirred until the resin temperature reached 100 ° C. This mixture was extruded with a 40 mmφ single screw extruder at a die temperature of 170 ° C. to form pellets.

<Preparation of Soft Resin Composition> Average degree of polymerization 23
100 parts by weight of vinyl chloride resin (PVC-2) of 50, 3 parts by weight of barium-zinc composite stabilizer, 0.4 parts by weight of lubricant, predetermined amount (described in Table-1) of diisononyl phthalate (DINP), acrylic resin (P551A, manufactured by Mitsubishi Rayon, methyl methacrylate / alkyl acrylate = 70
˜90 / 30 to 10% by weight) and calcium carbonate were added, and the mixture was stirred until the resin temperature reached 105 ° C. and dried up. Predetermined amount for this dry blend (listed in Table-1)
NBR (acrylonitrile content 30%, THF insoluble crosslinking component 89.4% by weight) or commercially available AR (THF insoluble crosslinking component 93.9% by weight) and crosslinking agent (2,5-dimethyl-2,5-di). (T-butylperoxy) hexane) was added and the resin temperature was adjusted to 16 with a Banbury mixer.
After kneading up to 5 ° C. (however, in Example 7, up to 185 ° C.), it was formed into a sheet by a roll and pelletized by a sheet cutting method.

<Molding of weather strip> 20 mmφ
Hard resin pellets are extruded with an extruder and soft resin composition pellets are extruded with a 40 mmφ extruder, and the die temperature is 190 ° C.
A continuous co-extrusion molded product having a T-shaped cross section was obtained in which one end of a strip-shaped soft resin composition plate (height 21 mm, thickness 1 mm) was welded to the surface of the strip-shaped hard resin plate (width 10 mm, thickness 1 mm). With respect to the weather strip molded in this way, the compression set of the soft resin composition portion was measured according to JIS K63.
According to No. 01, the compressibility was 50%, the temperature was 100 ° C., the condition was 22 hours, and the deformability of the weather strip was evaluated as follows.

A long weatherstrip having an inverted T-shaped cross section is maintained horizontally at a height of 50 mm, and 1 from the free tip.
A place with a length of 00 mm was fixed. In this state, it was kept in an oven at 100 ° C. for 22 hours and left at room temperature for 30 minutes, then the degree of lowering of the free tip was measured, and the deformation rate was calculated by the following formula.

[Formula 1] Deformation rate (%) = {(50-tip height after test)
÷ 50} × 100

[0027]

[Table 1]

Claims (9)

[Claims] 1. A hard resin composed of a chlorinated vinyl chloride resin or a mixture of a chlorinated vinyl chloride resin containing 20% by weight or more of a chlorinated vinyl chloride resin and a vinyl chloride resin, 100 parts by weight of the vinyl chloride resin and tetrahydrofuran. Rubber substances 10 to 4 containing 30% by weight or more of insoluble crosslinking component
A weather strip formed by combining a soft resin composition containing 00 parts by weight and 30 to 300 parts by weight of a plasticizer as main components. 2. The average degree of polymerization of the vinyl chloride polymer before chlorination of the chlorinated vinyl chloride resin is in the range of 400 to 1500, and the degree of chlorination is in the range of 60 to 70% by weight. Weather strip. 3. The weather strip according to claim 1 or 2, wherein the vinyl chloride resin used in the soft resin composition has an average degree of polymerization of 700 to 8000. 4. The weather strip according to claim 1, wherein the rubber substance is nitrile rubber or acrylic rubber. 5. The weather strip according to claim 1, wherein the soft resin composition contains a filler. 6. The weather strip according to claim 1, wherein the soft resin composition contains an acrylic resin. 7. A strip-shaped molded article made of a soft resin composition, the strip-shaped end portion of which is welded or adhered in a T-shaped cross section on the surface of the strip-shaped molded article made of a hard resin. Weather strip as described in. 8. The weather strip according to claim 1, wherein the strip-shaped end portions of the respective strip-shaped molded products made of a hard resin and a soft resin composition are welded or adhered to each other in an L-shaped cross section. . 9. The weather strip according to claim 1, wherein the hard resin is entirely coated with the soft resin composition.